Streptococcal

J Clin Microbiol, 2002 Jan, 40(1), 68 - 74
Emergence of penicillin-nonsusceptible Streptococcus pneumoniae invasive clones in Canada; Greenberg D et al.; Distinctive international clones of penicillin-nonsusceptible and multidrug-resistant Streptococcus pneumoniae are increasingly being reported . We investigated the spread of these clones in Canada through an active surveillance that was carried out at 11 Canadian pediatric tertiary care centers from 1991 to 1998 . All penicillin-nonsusceptible isolates were serotyped, tested for antibiotic susceptibility, and genotyped by pulsed-field gel electrophoresis (PFGE) and random amplified polymorphic DNA (RAPD) . Forty-five penicillin-nonsusceptible S . pneumoniae isolates were evaluated . Eleven serotype 9V isolates and six serotype 14 isolates displayed identical RAPD and PFGE fingerprint profiles . Twelve (70%) of these isolates were encountered in Quebec . The 9V/14 clone and the Spanish-French clone had similar PFGE fingerprint patterns . Eight isolates of serotype 23F and two isolates of serogroup 14 had the same fingerprint profiles and displayed resistance to three or more antibiotic drug classes . This clone was first detected in Calgary (Alberta) and in 1996 appeared simultaneously in various regions of Canada . This clone showed a PFGE fingerprint pattern similar to that of the Spanish-U.S . 23F clone . Our data show the emergence across Canada of two international clones of penicillin-nonsusceptible S . pneumoniae: (i) serotypes 9V and 14 related to the Spanish-French clone and (ii) the 23F Spanish-U.S . clone . The source of the first clone was in Quebec and the second international clone was probably originated from the United States . The exact reasons for the successful spread of these clones within Canada and their contribution to increased resistance to antibiotics have yet to be explored.

Acad Emerg Med, 2002 Jan, 9(1), 9 - 14
A randomized clinical trial of oral versus intramuscular delivery of steroids in acute exudative pharyngitis; Marvez-Valls EG et al.; Previous study has shown that the use of intramuscular (IM) steroid leads to improved symptoms in patients with group A beta-hemolytic streptococcus (GABHS) . OBJECTIVE: To compare oral with IM steroids as an adjunct to antibiotic therapy in the treatment of acute exudative pharyngitis . The null hypothesis was that there would be no difference in effectiveness of oral versus IM steroids . METHODS: The study was a randomized, double-blind outpatient clinical trial . After consent was obtained, each patient was asked to rate his or her pain on a 10-cm numbered visual analog scale (VAS; 0-10) . All of the patients received injectable benzathine penicillin or, if allergic to penicillin, a ten-day course of polyenteric-coated erythromycin . Each patient was randomized to receive either injectable steroid plus oral placebo or injectable placebo plus oral steroid . All medications were given in the emergency department . All patients were contacted by telephone at 24 hours (first follow-up) and 48 hours (second follow-up) by one of the study investigators and asked to rate their pain based on another VAS . If their pain was not resolved by 48 hours, they were called again daily for the third to seventh day after the initial visit . The time to total resolution of the sore throat was documented . The main outcome measures were time to complete relief of pain and VAS scores . Pain medication was not controlled; however, use of pain medications and amounts were recorded . RESULTS: A total of 78 patients were initially enrolled in the study . Eight patients were excluded from the statistical analysis because of inability to follow up . A total of 70 were entered, with 35 randomized to IM steroid plus oral placebo and 35 to IM placebo plus oral steroid . There was no difference in pain scores for the oral versus IM group at first follow-up (p = 0.13) and second follow-up (p = 0.82), and in number of hours to relief of pain (p = 0.06) . Using repeated-measures analysis of variance, no difference in the effects of the two medications over time was detected (p = 0.83) . CONCLUSIONS: The results of this clinical trial suggest that oral steroid and IM steroid provide similar levels of pain relief in acute exudative pharyngitis.

Med J Malaysia, 2001 Jun, 56(2), 260 - 6; quiz 267
The management of upper respiratory tract infections; Teng CL et al.; Upper respiratory tract infections are the commonest reason for consultation in primary care . Group A beta-haemolytic Streptococcus (GABHS), the most important bacterial pathogen in this condition, can be cultured from about 30% of patients, more so in children than adults . Clinical features that are predictive of positive GABHS culture are absence of cough, fever, cervical adenopathy, tonsillar enlargement and tonsillar exudate . Use of a sore throat score can help in the detection of streptococcal throat infection . Symptomatic therapies which are useful include anticholinergic, antihistamine, decongestant, humified hot air and Vitamin C . Antibiotics are universally over-prescribed in this condition as a result of high patient expectation and faulty clinical decision making . Oral Penicillin V for 10 days is the drug of choice . Effective intervention to reduce inappropriate antibiotic prescription probably require a multifaceted approach targeted at both the patients and the prescribers.

Zhonghua Kou Qiang Yi Xue Za Zhi, 2001 Sep, 36(5), 385 - 7
{Experimental study of bacteriostatic activity of Chinese herbal medicines on primary cariogenic bacteria in vitro}; Wang S et al.; OBJECTIVE: To screen some Chinese herbal medicines for their inhibitory activity on cariogenic bacteria, and investigate their active ingredients, and measure their minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) . METHODS: Active components were isolated from every tested Chinese herbal medicine by means of aqueous extraction and ethanolic extraction . Berberine was purified from Coptis chinensis Fra . Disk agar diffusion method was employed in screening herbs with inhibiting effect on cariogenic bacteria . MIC and MBC were determined by broth dilution method . RESULTS: Against Streptococcus mutans Ingbritt, MBCs of Magnolia officinalis ethanolic extract, Berberine, Coptis chinensis Fra aqueous extract and Coptis chinensis Fra ethanolic extract were 0.488, 0.625, 7.800 and 1.950 g/L respectively . Against Streptococcus sobrinus 6715, MBCs of Magnolia extract, Coptis chinensis Fra ethanolic extract, Rhus chinensis Mill ethanolic extract and Phellodendron chinen ethanolic extract were 0.488, 0.625, 1.950, 3.900, 3.900 and 3.900 g/L respectively . Against Actinomyces viscosus ATCC 19246, MBCs of Berberine, Coptis chinensis Fra aqueous extract, Coptis chinensis Fra ethanolic extract, Rheum palmatum L aqueous extract and Rheum palmatum L ethanolic extract were 1.250, 3.900, 3.900, 15.600 and 31.250 g/L respectively . CONCLUSIONS: Magnolia officinalis, Coptis chinensis Fran, Rheum palmatum L aqueous extracts exhibit strong inhibition on cariogenic bacteria . Magnolia officinalis ethanolic extract has the strongest bactericidal effects on Streptococcus mutans and Streptococcus sobrinus.

Zhonghua Kou Qiang Yi Xue Za Zhi, 2001 Sep, 36(5), 354 - 6
{Effects of Streptococcus sanguis on blood composition, blood pressure and cardiac dysfunction in rabbis}; Chen H et al.; OBJECTIVE: To investigate effect of streptococcus sanguis on blood cell and cardiopulmonary changes . METHODS: 133-79 strains of streptococcus sanguis (aggregation positive) were infused intravenously into rabbits . Before and 5, 10, 20, 30, 45, 60 min after infuse platelets count, leukocytes count, blood pressure and ECG were measured . RESULTS: After infused intravenously, both platelets and leukocytes count decreased remarkably (P < 0.01, n = 12) . The ECG showed ST segment depression (> 0.06 mV) . Diphasic blood pressure occurred (first hypertensive then hypotensive) . CONCLUSIONS: Streptococcus sanguis 133-79 strains in circulation system might cause myocardia ischemia, blood pressure changes, peripheral circulation platelets and leukocytes decrease remarkably.

Rinsho Byori, 2001 Nov, 49(11), 1129 - 32
{Identification and epidemiologic investigation of bacteria by the Riboprinter Microbial Characterization System, the automated ribotyping system}; Iinuma Y; An automated ribotyping system, RiboPrinter Microbial Characterization System(Qualicon), was evaluated as a typing tool . Strains used in this study is as follows; 40 strains of methicillin-resistant Staphylococcus aureus (MRSA) with 40 distinct PFGE patterns, 20 MRSA from two hospital ward with suspicion of outbreaks, 53 strains of Escherichia coli including 43 strains of pathogenic E . coli, and 50 strains of Streptococcus pyogenes including 31 strains from patients with severe streptococcal disease . Typeability was 100% . Excellent result was obtained in identificating E . coli including Enterohemorrhagic E . coli O157, but poor in two species of gram positive cocci . Concerning discriminatory power, the RiboPrinter was generally less sensitive than PFGE in identifying different strains, but good correlation with strain relatedness by PFGE and antigenic classification . RiboPrinter surpassed PFGE at handling, result interpretation, and rapidity, therefore, hierarchical approach with the first pass through the RiboPrinter followed by PFGE as the occasion demands can be very useful to save labor . The RiboPrinter has the potential to be a widely useful tool in molecular epidemiology.

Clin Ther, 2001 Nov, 23(11), 1889 - 900
Open-Label, parallel-group, multicenter, randomized study of cefprozil versus erythromycin in children with group A streptococcal pharyngitis/tonsillitis; Brook I et al.; BACKGROUND: Cefprozil and erythromycin are acceptable alternatives to penicillin in the treatment of pharyngitis/tonsillitis due to group A beta-hemolytic streptococcus (GABHS) . OBJECTIVE: The purpose of this trial was to determine the relative efficacy and tolerability of cefprozil and erythromycin in the treatment of pediatric pharyngitis/tonsillitis due to GABHS . METHODS: This trial compared the bacteriologic and clinical efficacy of erythromycin and cefprozil in children 2 to 12 years of age with culture-documented GABHS pharyngitis/ tonsillitis . Children who were allergic to penicillin, cefprozil, or erythromycin were excluded . Patients were prospectively randomly assigned to receive 10 days of oral therapy with either cefprozil suspension 15 mg/kg per day in 2 divided doses or erythromycin ethylsuccinate suspension 30 mg/kg per day in 3 divided doses . Primary efficacy end points were bacteriologic and clinical response 2 to 8 days after treatment ended . The frequency and severity of adverse events and their relationship to treatment were also assessed . RESULTS: A total of 199 patients were enrolled and treated (cefprozil, 99; erythromycin, 100); 12 patients in the cefprozil group and 15 in the erythromycin group were not evaluable . The GABHS eradication rate was significantly higher with cefprozil (95%) than with erythromycin (74%) (P = 0.001) . The posttreatment carrier rate was lower in the cefprozil group (5%) than in the erythromycin group (18%) (95% CI, -22.3 to -3.8) . Clinical cure rate was 90% (78/87) with cefprozil and 91% (77/85) with erythromycin (P = 0.95) (treatment group difference, -0.93; 95% CI, -9.9% to 8.0%) . The overall incidence of drug-related adverse events was not significantly different in the 2 groups (11% with cef- prozil, 18% with erythromycin) . The most common adverse events were diarrhea and vomiting . Two patients in the erythromycin group discontinued therapy because of adverse events . CONCLUSIONS: The bacteriologic eradication rate was significantly greater with cefprozil compared with erythromycin in children with pharyngitis/tonsillitis . Both cefprozil and erythromycin produced a clinical cure in >90% of patients.

Biotechniques, 2001 Dec, 31(6), 1382 - 6, 1388
Rapid competitive PCR using melting curve analysis for DNA quantification; Al-Robaiy S et al.; A rapid competitive PCR method was developed to quantify DNA on the LightCycler . It rests on the quantitative information contained in the melting curves obtained after amplification in the presence of SYBR Green I . Specific hybridization probes are not required . Heterologous internal standards sharing the same primer binding sites and having different melting temperatures to the natural PCR products were used as competitors . After a co-amplification of known amounts of the competitor with a DNA-containing sample, the target DNA can be quantified from the ratio of the melting peak areas of competitor and target products . The method was developed using 16S rDNA fragments from Streptococcus mutans and E . coli and tested against existing PCR-based DNA quantification procedures . While kinetic analysis of real-time PCR is well established for the quantification of pure nucleic acids, competitive PCR on the LightCycler based on an internal standardization was found to represent a rapid and sensitive alternative DNA quantification method for analysis of complex biological samples that may contain PCR inhibitors.

Nippon Jibiinkoka Gakkai Kaiho, 2001 Nov, 104(11), 1089 - 92
{A case of pediatric recurrent acute mastoiditis caused by penicillin-resistant Streptococcus pneumonia complicated by primary immunodeficiency}; Fukuiwa T et al.; Penicillin-resistant Streptococcus pneumoniae (PRSP) is a frequently detected pathogen of intractable acute otitis media and is associated with prolonged or recurrent infection . The use of antibiotics has made the incidence of secondary acute mastoiditis following acute otitis media relatively rare, but when it does occur, its severe complications may be life-threatening . We report a case of pediatric recurrent acute mastoiditis caused by PRSP in a 6-year-old boy suffering from PRSP acute mastoiditis on 4 occasions, twice undergoing simple mastoidectomy . Although we initially suspected PRSP to be the chief factor in iterative infection, immunological analysis demonstrated significantly decreased IgG and IgA antibodies in serum and the patient was diagnosed as having common variable immunodeficiency (CVID) . As the first middle ear infection occurred at the age of 6 and there was no history of upper respiratory tract infection, CVID may be the main pathological factor of recurrent mastoiditis, although infection occurred, only in the ear and did not involve other organs . This suggests that recurrent mastoiditis in the present case involved the coexistence of PRSP and CVID.

Kansenshogaku Zasshi, 2001 Nov, 75(11), 977 - 80
{Acute subdural abscess due to mixed infection of Eikenella corrodens and Streptococcus constellatus}; Nakao A et al.; Eikenella corrodens is a gram-negative, facultative anaerobic rod that frequently exists as part of normal human flora in the upper respiratory tract and gastrointestinal tract . Recently, E . corrodens is reported as a rare causative agent of empyematic lesion . We report a case of 10-year-old girl with acute subdural abscess . She developed a high grade fever, swelling of the left periorbital area, right sided partial seizure and hemiplegia . Brain CT and MRI showed left parietal subdural abscess . Because intravenous antibiotic therapy was not effective enough and her neurological symptoms progressed, surgical drainage was performed in order to decompress the brain and to determine the causative agents . Through careful bacterial cultures, E . corrodens and Streptococcus constellatus were detected from the subdural abscess . After the drainage operation and a three week course of appropriate chemotherapy, the abscess completely disappeared and no sequela remained.

Otolaryngol Pol, 2001, 55(3), 299 - 302
Antibiotic sensitivity of bacteria isolated in 1998 and 1999 from patients with infections of upper airways residing in Western Pomerania; Giedrys-Kalemba S et al.; Sensitivity to antibiotics of the most common pathogens isolated from the upper airways in north-west part of Poland shown significant regional variation . The rise in resistance to penicillin for Streptococcus pneumoniae (to 22%) and to macrolides for Streptococcus pyogenes, Streptococcus pneumoniae and Staphylococcus aureus was observed . No differences in sensitivity have been found between pathogens isolated from hospital and ambulatory patients.

J Mol Microbiol Biotechnol, 2002 Jan, 4(1), 101 - 10
A XerD recombinase with unusual active site motifs in Streptococcus pneumoniae; Reichmann P et al.; XerD belongs to the site specific recombinases of the integrase family of proteins that catalyze recombination events via a phosphotyrosine intermediate . Sequence alignments and crystal structure resolution of E . coli XerD and related enzymes demonstrated the importance of four conserved amino acids R-H-R-H that are spaced along the C-terminal domain in addition to a conserved K and the active site Y, all of which have been implicated in catalysis . The deduced amino acid sequence of the putative S . pneumoniae XerD contained three unique replacements at the conserved positions resulting in L-Q-R-L; moreover, the active site Y was the penultimate amino acid residue, and the extreme C-terminal region suggested to be involved in interaction of E . coli XerD with XerC was lacking . Severe growth defects in a loss-of-function xerD mutant are consistent with an important in vivo function of the S . pneumoniae XerD protein . Highly related xerD genes with similar unusual amino acid replacements were found in S . mitis, S . mutans and S . pyogenes but not in other Gram-positive bacteria, although the genetic environment was very similar in many species . There are at least another four genes in the S . pneumoniae KNR_7/87 genome encoding Xer related peptides, one of which was identified as the xerC homologue . The xerD and xerC genes were present in a sample of 20 S . pneumoniae strains whereas the other xer genes appear to be absent in some of the strains and are more closely related to integrases of phage and transposon origin.

Am J Dent, 2000 Sep, 13(Spec No), 14C - 17C
Caries inhibition efficacy of an antiplaque/antigingivitis dentifrice; Yu D et al.; PURPOSE: To evaluate the efficacy of a fluoride dentifrice containing a fixed combination of essential oils (Thymol, Menthol, Eucalyptol, and Methyl Salicylate) in preventing caries in Sprague Dawley rats . MATERIALS AND METHODS: The dentifrice contains 0.76% sodium monofluorophosphate (SMFP) as the fluoride source and a silica abrasive system . A fluoride-free placebo and a clinically proven USP dentifrice reference standard for SMFP/silica were included as controls . Three groups of 45 SDV-free Sprague Dawley weanlings were infected by a cariogenic strain of Streptococcus sobrinus and fed cariogenic diet NIH 2000 ad libitum . Animals were treated twice daily (once on weekends) with the assigned dentifrice using a cotton-tipped applicator, for 5 wks, after which they were terminated and caries scored using Larson's modification of the Keyes method . RESULTS: Analyses of variance were used to compare inter-group means, the total E lesion score was the primary efficacy variable . Compared with the fluoride-free vehicle control, the experimental dentifrice and USP reference standard dentifrice produced a statistically significant reductions of 18.3% and 12.2% respectively for total caries score (P<0.001) . Compared with the clinically tested USP positive control dentifrice, the experimental dentifrice produced a statistically significant reduction in the total caries score of 6.9% (P=0.028) . The results of this study show that 1) both the new dentifrice containing essential oils and USP dentifrice are statistically significantly effective in reducing caries in the rat model, 2) the anticaries activity of the SMFP dentifrice is not adversely affected with the addition of essential oils.

Microbiol Immunol, 2001, 45(10), 699 - 707
Anti-fibrin antibody binding in valvular vegetations and kidney lesions during experimental endocarditis; Yokota M et al.; In Streptococcus sanguinis (sanguis) induced experimental endocarditis, we sought evidence that the development of aortic valvular vegetation depends on the availability of fibrin . Endocarditis was induced in New Zealand white rabbits by catheter placement into the left ventricle and inoculation of the bacteria . Fibrin was localized in the developing vegetation with 99mTechnetium (Tc)-labeled anti-fibrin antibody one or three days later . When rabbit anti-fibrin antibody was given intravenously on day 1, the mass of aortic valvular vegetation was significantly reduced at day 3; infusion of non-specific rabbit IgG showed no effect . The 99mTc-labeled anti-fibrin antibody also labeled kidneys that showed macroscopic subcapsular hemorrhage . To learn if the deposition of fibrin in the kidneys was a consequence of endocarditis required a comparison of farm-bred and specific pathogen-free rabbits before and after the induction of endocarditis . Before induction, the kidneys of farm-bred rabbits were labeled, but specific pathogen-free rabbits were free of labeling and signs of macroscopic hemorrhage . After 3 days of endocarditis, kidneys of 10 of 14 specific pathogen-free rabbits labeled with 99mTc-labeled anti-fibrin antibody and showed hemorrhage . Kidney lesions were suggested to be a frequent sequellae of S . sanguinis infective endocarditis . For the first time, fibrin was shown to be required for the continued development of aortic valvular vegetations.

J Chemother, 2001 Oct, 13(5), 541 - 5
Streptococcus pneumoniae penicillin resistance in Turkey; Gur D et al.; Resistance of Streptococcus pneumoniae (750) to penicillin, erythromycin, chloramphenicol and trimethoprim/sulfamethoxazole isolated in 4 Turkish hospitals between 1996 and 1999 was evaluated according to year of isolation, patients' age groups and specimen . Penicillin susceptibility was determined by E-test strips and the other antibiotics were tested by disk diffusion test following the NCCLS guidelines in each center . Overall high and intermediate resistance to penicillin was 3% and 29%, respectively . There was a significant difference (p<0.001) between the centers with regard to penicillin resistance . However, there was no significant increase in resistance by year . Penicillin resistance varied significantly among children and adults (36% versus 25%) and according to the specimen . Highest rate of penicillin resistance was observed in respiratory specimens (36%) followed by ear exudates (33.5%) . In blood isolates, resistance to penicillin was 28.6% . Overall resistance to erythromycin was 8%, to chloramphenicol 5% and to trimethoprim-sulfamethoxazole 47% . Although overall penicillin resistance in these Turkish S . pneumoniae isolates is high, resistance rates vary in each center and have not increased from 1996 to 1999.

J Chemother, 2001 Oct, 13(5), 535 - 40
Time-kill evaluation of antimicrobial regimens against clinical isolates of penicillin-resistant Streptococcus pneumoniae; Banon Arias R et al.; The rate of penicillin-resistant Streptococcus pneumoniae isolates in Spain is high . At present, penicillin and ceftriaxone are two drugs chosen for treating serious infections . In this study the bactericidal activity of four antimicrobial regimens against ten clinical isolates of S . pneumoniae (five with an intermediate resistance to penicillin and five highly resistant ones), was determined by means of kill kinetics studies using either penicillin, or ceftriaxone, in combination with vancomycin, or fosfomycin . The concentrations of the antimicrobial regimens (MICs 4x, 1x and 1/4x) were within possible physiological levels . While the combinations of penicillin, or ceftriaxone, plus vancomycin showed a significant increase in bactericidal activity, the bacterial reductions obtained in combination with fosfomycin were greater, achieving synergistic effects . These results suggest that in vivo trials with a regimen composed of ceftriaxone and fosfomycin would be worthwhile.

Scand J Infect Dis, 2001, 33(11), 854 - 6
Non-tropical thoraco-abdominal pyomyositis caused by group A streptococcus in an immunocompetent adult; Cherry C et al.; We present a case of group A streptococcal pyomyositis of the thoraco-abdominal wall of an immunocompetent adult . This diagnosis was made when soft tissue swelling was seen on chest X-ray . Complete recovery followed drainage of the collection and short-course i.v . penicillin . The importance, diagnosis and treatment of pyomyositis are outlined.

Scand J Infect Dis, 2001, 33(11), 815 - 7
Dental caries is common in Finnish children infected with Helicobacter pylori; Kolho KL et al.; Childhood factors such as low socioeconomic status are risk factors for Helicobacter pylori infection and Streptococcus mutans-related dental caries . We examined whether H . pylori infection and dental caries are present today in the same group of children examined previously . We reviewed the public dental health service files of 21 H . pylori-positive children (upper gastrointestinal endoscopy at a median age of 13.5 y) and 27 H . pylori-negative children (endoscopy at a median age of 12.5 y) examined during 1995-98 at the Helsinki University Central Hospital, Finland . All H . pylori-positive children had experienced dental caries in their primary or permanent teeth or in both whereas among H . pylori-negative children the respective proportion was 70% (p < 0.01) . At the age of 7 y, 18% (3/17) of the H . pylori-positive children had experienced caries in permanent teeth as compared to 0% among H . pylori-negative children (0/24; p < 0.05) . At the age of 12 y, H . pylori-positive children had more decayed, missing or filled permanent teeth than H . pylori-negative children (80% vs . 38%; p < 0.05) . Although a causal relationship between H . pylori and dental caries is unlikely, it is possible that H . pylori-infected children have an increased risk of other health problems, such as dental caries, for which proper treatment is needed.

J Med Assoc Thai, 2001 Jul, 84(7), 995 - 9
Spontaneous bacterial peritonitis, causes and antibiotic usage in Srinagarind hospital; Lolekha P et al.; Spontaneous bacterial peritonitis (SBP) is a common and often fatal complication occurring in cirrhotic patients with ascites . It is defined as an infection of the ascitic fluid in the absence of any obvious intra-abdominal source . This study was a descriptive retrospective study that examined signs and symptoms of SBP, prevalence, result of the culture and antibiotic susceptibility of the organisms and outcome of antibiotic treatment, especially to ampicillin-aminoglycoside . Data were collected from inpatient medical records at Srinagarind Hospital between 1993 and 1997 . Forty-four patients with 54 episodes of SBP were included in this study . The results revealed that SBP commonly occurred in cirrhotic patients . Presenting symptoms of SBP were fever, abdominal pain and abdominal distension, respectively . Signs of SBP were ascites and rebound abdominal tenderness . Forty-three per cent of ascitic fluid cultures were positive for bacteria E . coli (30.4%), Streptococcus spp (26.1%) and Klebsiella spp (13.0%) were the most common causes of SBP which were similar to other studies . Ampicillin plus an aminoglycoside were mostly often used in this study; in only 15.8 per cent of patients did the antibiotics need to be changed . Mortality rate in this group was not increased after antibiotic was changed.

J Med Assoc Thai, 2001 Jul, 84(7), 1056 - 8
Microaerophilic streptococcus meningoencephalitis: report of a case; Chotmongkol V et al.; A 64-year-old woman who presented with acute meningoencephalitis was reported . Cerebrospinal fluid (CSF) revealed polymorphonuclear pleocytosis with gram-positive cocci . Blood and CSF grew microaerophilic streptococcus . The patient was treated with intravenous penicillin G and chloramphenicol for 2 weeks and recovered without sequela . There was no evidence of any focus of infection prone to the development of this infection.

Microb Drug Resist, 2001 Fall, 7(3), 277 - 87
Prevalence of antimicrobial resistance in Streptococcus pneumoniae circulating in Italy: results of the Italian Epidemiological Observatory Survey (1997-1999); Marchese A et al.; The Italian Epidemiological Observatory (IEO), a surveillance program supported by the SmithKline Foundation, analyzed the susceptibility of 2,664 community-acquired respiratory Streptococcus pneumoniae derived from over 50 clinical microbiology laboratories during 1997-1999, against 21 antibiotics adopting a quantitative methodology . Throughout these years, total penicillin resistance varied from 14.3% to 10.2% . High-level resistance has remained stable, ranging from 3.8% to 4.1%, while a decrease in low-level resistance (from 10.3% to 6.1%) has been recorded . Lack of susceptibility to macrolides ranged from 29.1% in 1997 to 25.5% in 1999 . Similar figures have also been observed with tetracycline and co-trimoxazole (rates of resistance around 30%) . As expected, large geographical variations in resistance rates were found for all drugs . Amoxicillin and amoxicillin-clavulanate were 100% active on penicillin-intermediate isolates . Injectable third-generation cephalosporins and carbapenems were also capable of inhibiting a large proportion of these microorganisms . Rifampin was the most potent non-beta-lactam compound tested . In contrast to the situation prevailing elsewhere, in Italian children (aged 0-5 years) presenting with respiratory conditions, the total rate of penicillin resistance (3%) was lower than that shown by the adult population (10.9%) . However, lack of susceptibility to macrolides, tetracycline, and cotrimoxazole (35%, 41%, 44%) was more incident in pediatric than in adult patients (25%, 26%, 28% respectively) . Strains recovered from blood in 1999 (67) were much more susceptible to penicillin (98.5%) than respiratory pneumococci (89.8%), whereas macrolides, tetracycline, and cotrimoxazole were consistently less active (75%, 67%, 64%).

Microb Drug Resist, 2001 Fall, 7(3), 213 - 22
Molecular characterization of the pneumococcal teichoic acid phosphorylcholine esterase; de las Rivas B et al.; A search to identify proteins with high affinity for choline-containing pneumococcal cell walls (choline-binding proteins) has permitted the localization, cloning, sequencing, and overexpression of a gene (pce), coding for a protein (Pce) that liberates phosphorylcholine from purified cell walls of Streptococcus pneumoniae . The pce gene of the pneumococcal strain R6 encodes a protein of 627 amino acids with a predicted Mr of 72,104 . Pce can remove a maximum of 20% phosphorylcholine residues from the cell wall teichoic acid . In silico analysis of Pce shows a modular organization of the enzyme where the choline-binding domain, involved in cell wall substrate recognition, and the catalytic domain are located at the carboxy- and amino-terminal moieties of the protein, respectively . Remarkably, a long tail of 85 amino acids follows the carboxy-terminal domain, a structural feature that had not been described for the published choline-binding proteins . The carboxy-terminal moiety of Pce is assembled by 10 repeated motifs, and the protein has also a cleavable signal peptide of 25 amino acids that renders after its cleavage a mature protein of 69,426 Da (602 amino acids) . The pce gene has been expressed in Escherichia coli, and Pce was active when assayed on pneumococcal walls . We have also found that the signal peptide of Pce was functional in E . coli . Biochemical analysis suggested that Pce is the teichoic acid phosphorylcholine esterase of S . pneumoniae that had been biochemically characterized previously . Construction of two pce pneumococcal mutants (R6D and M31D) by insertion-duplication mutagenesis revealed that these mutants grew at a doubling-time similar to those of the parental strains of the wild-type R6 and the lytA-mutant M31, respectively . R6D and M31D were morphologically indistinguishable from the parental strains when whole-mounted cells were observed under the electron microscope and exhibited levels of competence for genetic transformation slightly lower than those reported for R6 and M31.

J Infect Dis, 2002 Jan 1, 185(1), 123 - 6 Epub 2001 Nov 30.
Roles of interleukin-6 and macrophage inflammatory protein-2 in pneumolysin-induced lung inflammation in mice; Rijneveld AW et al.; Pneumolysin (PLY), a toxin synthesized by Streptococcus pneumoniae, is an important virulence factor in pneumococcal disease . This study evaluated the effects of PLY in lungs of mice . Intranasal inoculation with PLY was associated with a dose-dependent influx of polymorphonuclear leukocytes (PMNL) in bronchoalveolar lavage fluid (BALF) and increased concentrations of interleukin (IL)-6, macrophage inflammatory protein (MIP)-2, and KC in BALF . PLY mutants with either reduced cytolytic activity or reduced cytolytic and complement-activating activities were less potent in inducing PMNL recruitment to the lung (P<.05), which suggests that PLY cytolytic activity is very important for the inflammatory response . IL-6 and MIP-2 also played a role in PLY-induced PMNL recruitment; this response was partially diminished in IL-6 gene-deficient mice and in mice treated with anti-MIP-2 antiserum . PLY may play an important role in the induction of an inflammatory response in the pulmonary compartment in the early phase of pneumococcal pneumonia.

J Infect Dis, 2002 Jan 1, 185(1), 91 - 7 Epub 2001 Dec 14.
The role of interferon-gamma in murine pneumococcal pneumonia; Rijneveld AW et al.; To determine the role of interferon (IFN)-gamma in pneumonia, IFN-gamma receptor-deficient (IFN-gamma R(-/-)) and 129/Sv (wild-type {wt}) mice were inoculated intranasally with Streptococcus pneumoniae . Although mortality did not differ between the groups 48 h after inoculation, IFN-gamma R(-/-) mice had significantly fewer pneumococci in their lungs than the wt mice . Similarly, IFN-gamma(-/-) mice had fewer colony-forming units in lungs than wt mice . The relatively increased resistance of IFN-gamma R(-/-) mice was not related to favorable effects on defense mechanisms known to contribute to antibacterial immunity-that is, the neutrophilic influx was reduced and the cytokine and nitric oxide levels were similar or lower in IFN-gamma R(-/-) mice . In contrast, mice treated with anti-IFN-gamma did not demonstrate a consistently altered bacterial outgrowth, compared with mice treated with a control antibody . These data suggest that endogenous IFN-gamma, despite its protective role in defense against intracellular pathogens, does not serve a protective role during pneumococcal pneumonia.

Pediatr Res, 2002 Jan, 51(1), 106 - 11
Polymorphisms in the cell wall-spanning domain of the C protein beta-antigen in clinical Streptococcus agalactiae isolates are caused by genetic instability of repeating DNA sequences; Berner R et al.; The C protein alpha- and beta-antigens are immunodominant components of the surface of Streptococcus agalactiae, the most frequent cause of neonatal sepsis . Both proteins are thought to contribute significantly to virulence of S . agalactiae . They are mainly expressed by serotypes Ia, Ib, and II . The C protein beta-antigen (Cbeta-protein) binds to the Fc portion of human IgA and seems to be of importance in bacterial resistance to mucosal immune defense mechanisms . In this study, PCR analysis of S . agalactiae isolates obtained from 189 neonates and 112 pregnant women revealed the presence of the Cbeta-protein gene in 19% and 22% of the isolates, respectively . Size polymorphisms of the PCR products within the gene region encoding the cell wall-spanning domain indicated a high degree of genetic variability . Thirteen different variants of the amplified region were differentiated among the 60 Cbeta-protein-positive isolates by sequence analysis . In all variants, the polymorphisms were caused by insertions and deletions of repetitive DNA elements that did not alter the open reading frame . Comparison of the Cbeta-protein gene polymorphisms showed a significantly higher rate of isolates carrying deletions >50 bp in serotype Ib than in serotype II isolates (p = 0.001); this was also true for neonatal isolates analyzed separately (p = 0.01) . Neonatal isolates carried a higher rate of large deletions when compared with maternal isolates; this difference, however, did not reach statistical significance (p = 0.08) . We hypothesize that polymorphisms in the cell wall-spanning domain of the Cbeta-protein are of functional relevance with regard to maternofetal transmission of the pathogen.

Dev Comp Immunol, 2002 Apr, 26(3), 257 - 69
Activation of nonspecific cytotoxic cells (NCC) with synthetic oligodeoxynucleotides and bacterial genomic DNA: binding, specificity and identification of unique immunostimulatory motifs; Oumouna M et al.; We have analyzed the effects of synthetic oligodeoxynucleotides (sODNs) and bacterial DNA (bDNA) on the in vitro activation of NCC . Teleost NCC recognition of DNA appeared to differ from that which occurs in higher vertebrates . NCC contain at least two different receptor specificities for DNA . Both oligodeoxyguanosine 20-mers (dG20) and 5'-TGCTGCTTGTGCTTGTGCTT-3' (4GC-2T) bound specifically to NCC . The existence of different receptor specificities was indicated by reciprocal cold target inhibition experiments . dG20 competed with 4GC-2T binding but sODNs composed of GpC or CpG nests did not compete with recognition by NCC of the dG20 . ODN binding by NCC primarily depended on the presence of GpC or CpG nests with a preference for -G- serving as the anchor nucleotide . Secondarily, and similar to models of ODN activation in mammals, palindrome sequences of pu-pu-CpG-py-py activated NCC cytotoxicity . Additional analysis of the requirements for ODN activation indicated that guanosine could not substitute for adenosine as a purine spacer and that CpG motifs containing flanking thymidine (i.e.-GTCpGTT-) augmented the activity of the sODN containing this flanking base . Other evidence for the participation of both G and C in the recognition of specific nucleotides by NCC was that poly-dC20, dA20 or dT20 had no activating properties . Methylation of all cytosine nucleotides within an ODN abrogated activation . A canonical ODN motif of 5'-C/AT/AGCTT-3' can now be suggested for teleosts . Additional studies were done to examine the effects of in vitro treatment of NCC with bDNA . bDNA from three different disease isolates of Streptococcus iniae activated NCC cytotoxicity . Treatment of the bDNA with DNase abrogated the enhancement of cytotoxicity . Also, treatment of NCC with eukaryotic DNA had no effects on cytotoxicity . These studies suggested that NCC recognize bacterial nonmethylated DNA . The consequences of these interactions may be increased innate and acquired anti-bacterial immunity.

Obstet Gynecol, 2001 Dec, 98(6), 1075 - 9
Maternal and transplacental pharmacokinetics of cefazolin; Fiore Mitchell T et al.; OBJECTIVE: To evaluate the intrapartum pharmacokinetics of cefazolin, including delivery to amniotic fluid (AF) and fetal compartments, and to ascertain that adequate cefazolin concentrations are attained to exceed the mean concentration inhibiting 90% (MIC(90)) of group B streptococcus strains . METHODS: Cefazolin (1 g) was administered intravenously at five separate time intervals (0.5, 1, 2, 4, and 6 hours) before elective cesarean at term to 26 women with intact membranes and with no significant infections or cardiovascular, liver, or renal disease . Samples of maternal blood, cord blood, and AF were obtained at the time of delivery . Exact collection times relative to cefazolin infusion were noted . Amniotic fluid contaminated with blood or meconium was excluded . Cefazolin concentration was measured by high-pressure liquid chromatography . RESULTS: All maternal and cord plasma cefazolin levels, except one, were above the MIC(90) for Streptococcus agalactiae (group B streptococcus) . For AF, all cefazolin levels, except two, were above the MIC(90) . CONCLUSIONS: Cefazolin concentrations greater than or equal to the MIC(90) for group B streptococcus were attained in nearly all maternal, fetal, and AF samples . This information, together with the knowledge that there is rare resistance of group B streptococcus to cefazolin, supports the use of cefazolin as a better alternative than clindamycin or erythromycin for group B streptococcus prophylaxis in patients with a nonanaphylactic penicillin allergy.

Am J Med, 2001 Dec 17, 111 Suppl 9A, 13S - 18S; discussion 36S-38S
Pharmacodynamic profiling of levofloxacin and gatifloxacin using Monte Carlo simulation for community-acquired isolates of Streptococcus pneumoniae; Nicolau DP et al.; In vitro and in vivo models of infection suggest that the area under the concentration-time curve (AUC): minimum inhibitory concentration (MIC) ratio is the pharmacodynamic parameter that is most predictive of bactericidal activity for the fluoroquinolones . Additionally, this parameter has also been correlated with clinical outcomes in humans with respiratory tract infection . Despite these defined relationships, broad-scale application of these principles in the section of optimal therapy in the clinical arena has been restricted by the imprecise estimates of drug exposures (ie, AUC:MIC ratio) in the infected population . In an effort to best describe the known variability in the pharmacokinetic and susceptibility profile of agents of interest, Monte Carlo simulation has been employed to assess the probability of attaining the desired AUC:MIC ratio . In this report Monte Carlo simulation was used to estimate the probability of attaining various target AUC:MIC ratios using AUC values from patients treated with either gatifloxacin or levofloxacin and the in vitro potency of the compounds as assessed in 881 clinical isolates of Streptococcus pneumoniae isolated from outpatients . Using a simulated patient population of 5,000, the median AUC:MIC ratios were 144 and 50 for gatifloxacin and levofloxacin, respectively . The probability of attaining AUC:MIC ratios of 30, 40, 65, 100, and 125 for gatifloxacin were 99%, 95%, 85%, 68%, and 60%, respectively . For levofloxacin, similar dynamic hit rates were 82%, 61%, 35%, 17%, and 12% over the range of target values . Regardless of the optimal ratio selected, gatifloxacin had a higher probability of achieving the AUC:MIC target than did levofloxacin . Simulations of this type can assist in the decision process surrounding the choice of optimal therapies based on our current understanding of antimicrobial pharmacodynamic principles.

Acta Crystallogr D Biol Crystallogr, 2002 Jan, 58(Pt 1), 165 - 6 Epub 2001 Dec 21.
Crystallization and preliminary crystallographic analysis of the soluble alpha-glycerophosphate oxidase from Streptococcus sp; Finnerty CM et al.; Single crystals of soluble FAD-dependent alpha-glycerophosphate oxidase (GlpO) from Streptococcus sp . were obtained using the microseeding and hanging-drop vapor-equilibrium methods . Synchrotron X-ray radiation was used to collect diffraction data to 2.4 A resolution from these crystals . GlpO shares >30% identity with several bacterial and mitochondrial alpha-glycerophosphate dehydrogenases, although the GlpOs contain a 50-52-residue unique insert that appears to be important for efficient flavin reduction . The present work is an important first step in determining the structure of GlpO, which should provide insights on the function of this interesting flavoenzyme and its homologs.

J Immunol, 2002 Jan 1, 168(1), 372 - 8
IL-18 improves the early antimicrobial host response to pneumococcal pneumonia; Lauw FN et al.; To determine the role of endogenous IL-18 during pneumonia, IL-18 gene-deficient (IL-18(-/-)) mice and wild-type (WT) mice were intranasally inoculated with Streptococcus pneumoniae, the most common causative agent of community-acquired pneumonia . Infection with S . pneumoniae increased the expression of IL-18 mRNA and was associated with elevated concentrations of both precursor and mature IL-18 protein within the lungs . IL-18(-/-) mice had significantly more bacteria in their lungs and were more susceptible for progressing to systemic infection at 24 and 48 h postinoculation . Similarly, treatment of WT mice with anti-IL-18 was associated with enhanced outgrowth of pneumococci . In contrast, the clearance of pneumococci from lungs of IL-12(-/-) mice was unaltered when compared with WT mice . Furthermore, anti-IL-12 did not influence bacterial clearance in either IL-18(-/-) or WT mice . These data suggest that endogenous IL-18, but not IL-12, plays an important role in the early antibacterial host response during pneumococcal pneumonia.

J Bacteriol, 2002 Jan, 184(2), 610 - 3
Identification of a protein that inactivates the competence-stimulating peptide of Streptococcus pneumoniae; Berge M et al.; Competence for genetic transformation of Streptococcus pneumoniae is a transient physiological property inducible by a competence-stimulating peptide (CSP) . A 68-kDa CSP-inactivating protein was previously obtained following lithium chloride (LiCl) extraction . By the same protocol, a CSP-inactivating protein was purified and identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry as an endopeptidase, PepO . Analysis of a pepO mutant provided no support for the hypothesis that PepO participates in competence regulation . To reconcile in vitro and in vivo data, we suggest that LiCl treatment results in the release of intracellular molecules, including PepO.

J Bacteriol, 2002 Jan, 184(2), 577 - 83
Streptococcus pneumoniae capsule biosynthesis protein CpsB is a novel manganese-dependent phosphotyrosine-protein phosphatase; Morona JK et al.; The first four genes of the capsule locus (cps) of Streptococcus pneumoniae (cpsA to cpsD) are common to most serotypes . We have previously determined that CpsD is an autophosphorylating protein-tyrosine kinase, demonstrated that CpsC is required for CpsD tyrosine-phosphorylation, and shown that CpsB is required for dephosphorylation of CpsD . In the present study we show that CpsB is a novel manganese-dependent phosphotyrosine-protein phosphatase that belongs to the PHP (polymerase and histidinol phosphatase) family of phosphoesterases . We also show that an S . pneumoniae strain with point mutations in cpsB, affecting one of the conserved motifs of CpsB, is unencapsulated and appears to be morphologically identical to a strain in which the cpsB gene had been deleted.

J Bacteriol, 2002 Jan, 184(2), 433 - 43
Diversity of Tn4001 transposition products: the flanking IS256 elements can form tandem dimers and IS circles; Prudhomme M et al.; We show that both flanking IS256 elements carried by transposon Tn4001 are capable of generating head-to-tail tandem copies and free circular forms, implying that both are active . Our results suggest that the tandem structures arise from dimeric copies of the donor or vector plasmid present in the population by a mechanism in which an IS256 belonging to one Tn4001 copy attacks an IS256 end carried by the second Tn4001 copy . The resulting structures carry abutted left (inverted left repeat {IRL}) and right (inverted right repeat {IRR}) IS256 ends . Examination of the junction sequence suggested that it may form a relatively good promoter capable of driving transposase synthesis in Escherichia coli . This behavior resembles that of an increasing number of bacterial insertion sequences which generate integrative junctions as part of the transposition cycle . Sequence analysis of the IRL-IRR junctions demonstrated that attack of one end by the other is largely oriented (IRL attacks IRR) . Our experiments also defined the functional tips of IS256 as the tips predicted from sequence alignments, confirming that the terminal 4 bp at each end are indeed different . The appearance of these multiple plasmid and transposon forms indicates that care should be exercised when Tn4001 is used in transposition mutagenesis . This is especially true when it is used with naturally transformable hosts, such as Streptococcus pneumoniae, in which reconstitution of the donor plasmid may select for higher-order multimers.

J Antimicrob Chemother, 2002 Jan, 49(1), 173 - 6
Fluoroquinolone resistance among clinical isolates of Streptococcus pneumoniae belonging to international multiresistant clones; McGee L et al.; Twenty-nine fluoroquinolone (FQ)-resistant clinical isolates of Streptococcus pneumoniae from a collection of isolates from the Alexander Project (1992-1997) and a study from Northern Ireland were identified on the basis of ofloxacin MICs > or = 4 mg/L . DNA fingerprint analyses using BOX-fingerprinting and pulsed-field gel electrophoresis revealed serotype 9V and 23F high-level FQ-resistant strains indistinguishable from the pandemic Spain(23F)-1 and Spain(9V)-3 clones, the type strains of which are low-level resistant or susceptible to the fluoroquinolones.

J Antimicrob Chemother, 2002 Jan, 49(1), 113 - 9
Comparative pharmacodynamics of azithromycin and roxithromycin with S . pyogenes and S . pneumoniae in a model that simulates in vitro pharmacokinetics in human tonsils; Firsov AA et al.; Most macrolides penetrate and persist in peripheral tissues, irrespective of plasma concentrations . For this reason, comparative pharmacodynamics of macrolides might be better based on tissue rather than plasma pharmacokinetics . The present study compares the antimicrobial effects of azithromycin and roxithromycin on Streptococcus pyogenes and Streptococcus pneumoniae using in vitro simulations of steady-state pharmacokinetics in human tonsils expected after a third 500 mg dose of azithromycin administered once a day and after a sixth 150 mg dose of roxithromycin administered twice a day . Clinical isolates of S . pyogenes and S . pneumoniae (MICs 0.12 and 0.47 mg/L of azithromycin, and 0.15 and 0.60 mg/L of roxithromycin, respectively) were used . More pronounced antistreptococcal effects were observed with azithromycin than with roxithromycin . Despite similar rates of initial killing of S . pyogenes and S . pneumoniae, the respective 12 h areas between the control growth curve and the time-kill curve of antibiotic-exposed bacteria (ABBCs) were 22% and 36% greater with azithromycin than roxithromycin . Moreover, with azithromycin, viable bacterial counts reached the theoretically achievable limit of detection (10 cfu/mL) 8-10 h after drug administration, with no regrowth within 48 h . In contrast to azithromycin, S . pyogenes and S . pneumoniae exposed to roxithromycin regrew 26 and 6 h, respectively, after initial reduction of the starting inoculum . Further in vitro simulations of tissue pharmacokinetics might be useful for pharmacodynamic comparisons among other macrolides.

Clin Cancer Res, 2001 Dec, 7(12), 4182 - 94
Identification of a novel membrane protein, HP59, with therapeutic potential as a target of tumor angiogenesis; Fu C et al.; CM101, a polysaccharide isolated from the culture medium of Group B streptococcus, a neonatal pathogen, targets pathological angiogenesis and inhibits tumor growth in mice and humans . CM101 also targets neonatal lung and adult sheep lung endothelial cells . A gene encoding a transmembrane protein that interacts with CM101 was isolated from a sheep lung endothelial cell cDNA library . The gene, termed sp55, encodes a 495-amino acid polypeptide . COS-7 cells transfected with a vector containing sp55 express the SP55 protein-bound CM101 in a concentration-dependent manner . Stably transfected CHO cells also bound CM101 . The corresponding human gene, hp59, was isolated from a human fetal lung cDNA library and had a predicted identity to SP55 of 86% over 495 amino acids . HP59 protein was shown by immunohistochemistry to be present in the pathological tumor vasculature of the lung, breast, colon, and ovary, but not in the normal vasculature, suggesting that the protein may be critical to pathological angiogenesis . The hp59 gene and/or the HP59 protein was not expressed in a variety of normal tissues, but was significantly expressed in human fetal lung, consistent with the pathophysiology of Group B streptococcus infections in neonates . Mice immunized with HP59 and SP55 peptides showed significant attenuation of tumor growth . Immunization effectively inhibited both the tumor angiogenesis and vasculogenesis processes, as evidenced by lack of both HP59- and CD34-positive vessels . These results and the immunohistochemistry data suggest a therapeutic potential for the CM101 target protein HP59 both as a drug target and as a vaccine against pathoangiogenesis.

Antimicrob Agents Chemother, 2002 Jan, 46(1), 125 - 31
Diversity of ribosomal mutations conferring resistance to macrolides, clindamycin, streptogramin, and telithromycin in Streptococcus pneumoniae; Canu A et al.; Mechanisms of resistance were studied in 22 macrolide-resistant mutants selected in vitro from 5 parental strains of macrolide-susceptible Streptococcus pneumoniae by serial passage in various macrolides (T . A . Davies, B . E . Dewasse, M . R . Jacobs, and P . C . Appelbaum, Antimicrob . Agents Chemother., 44:414-417, 2000) . Portions of genes encoding ribosomal proteins L22 and L4 and 23S rRNA (domains II and V) were amplified by PCR and analyzed by single-strand conformational polymorphism analysis to screen for mutations . The DNA sequences of amplicons from mutants that differed from those of parental strains by their electrophoretic migration profiles were determined . In six mutants, point mutations were detected in the L22 gene (G95D, P99Q, A93E, P91S, and G83E) . The only mutant selected by telithromycin (for which the MIC increased from 0.008 to 0.25 microg/ml) contained a combination of three mutations in the L22 gene (A93E, P91S, and G83E) . L22 mutations were combined with an L4 mutation (G71R) in one strain and with a 23S rRNA mutation (C2611A) in another strain . Nine other strains selected by various macrolides had A2058G (n = 1), A2058U (n = 2), A2059G (n = 1), C2610U (n = 1), and C2611U (n = 4) mutations (Escherichia coli numbering) in domain V of 23S rRNA . One mutant selected by clarithromycin and resistant to all macrolides tested (MIC, >32 microg/ml) and telithromycin (MIC, 4 microg/ml) had a single base deletion (A752) in domain II . In six remaining mutants, no mutations in L22, L4, or 23S rRNA could be detected.

Antimicrob Agents Chemother, 2002 Jan, 46(1), 119 - 24
Prevalence of single mutations in topoisomerase type II genes among levofloxacin-susceptible clinical strains of Streptococcus pneumoniae isolated in the United States in 1992 to 1996 and 1999 to 2000; Davies TA et al.; Levofloxacin resistance in Streptococcus pneumoniae is rare, requiring at least two mutations in the quinolone resistance-determining region (QRDR) of topoisomerase IV and DNA gyrase . The prevalence of single QRDR mutations in these genes is unknown . Of 9,438 levofloxacin-susceptible pneumococci from the TRUST 4 surveillance study (1999-2000), 528 strains (MICs of 0.5 to 2.0 microg/ml) were selected for analysis . For comparison, 214 levofloxacin-susceptible strains (MICs of 0.5 to 1 microg/ml) isolated between 1992 and 1996 were analyzed . Oligonucleotide probe assay and DNA sequencing were used to detect QRDR mutations leading to changes at Ser79 and Asp83 in ParC, Ser81 in GyrA, and Asp435 in ParE, the most frequently found substitutions among levofloxacin-resistant strains . Among the 1992 to 1996 isolates only one strain (levofloxacin MIC, 1 microg/ml) had a mutation (Ser79 to Phe in ParC) . No single mutations were found among 270 TRUST 4 strains with levofloxacin MICs of 0.5 microg/ml . Among 244 strains for which levofloxacin MICs were 1 microg/ml, 15 strains (6.1%) had a parC mutation and 3 strains (1.2%) had a parE mutation . Of 14 strains for which levofloxacin MICs were 2 microg/ml, 10 strains (71%) had a parC mutation; no parE mutations were found . No gyrA mutations were detected . It was estimated that 4.5% of the 9,438 levofloxacin-susceptible TRUST 4 isolates (MICs, < or =0.06 to 2 microg/ml) had a single parC or parE QRDR mutation . Although there has been an increase in the prevalence of single-step mutants, the increase may have been overestimated due in part to differences in geographical distribution for the two sets of isolates.

Antimicrob Agents Chemother, 2002 Jan, 46(1), 69 - 74
Pharmacodynamics of gatifloxacin against Streptococcus pneumoniae in an in vitro pharmacokinetic model: impact of area under the curve/MIC ratios on eradication; Lister PD; Previous studies have demonstrated that fluoroquinolone area under the curve (AUC)/MIC ratios of 30 to 50 are sufficient to eradicate pneumococci from in vitro pharmacokinetic models (IVPMs) . However, more systematic studies of the impact of AUC/MIC ratios on the antipneumococcal activities of fluoroquinolones are needed . In the present study, a two-compartment IVPM was used to evaluate the impact of AUC/MIC ratios on the pharmacodynamics of gatifloxacin against four strains of Streptococcus pneumoniae . Gatifloxacin MICs were 0.4 to 1 microg/ml, whereas levofloxacin MICs were 1.8 to 3.2 microg/ml . Since both peak concentration/MIC (peak/MIC) and AUC/MIC ratios affect fluoroquinolone pharmacodynamics, logarithmic-phase cultures (5 x 10(7) CFU/ml) were exposed to gatifloxacin at constant peak/MIC ratios of 2:1 to 3:1 at 0 and 24 h, elimination half-lives were varied to provide a range of AUC/MIC ratios, and changes in viable counts were measured over 30 h . As a comparison, levofloxacin was evaluated at similar peak/MIC ratios and at AUC/MIC ratios of 30 to 38 . For each strain, killing rates through 4 to 8 h were similar since peak/MIC ratios were kept constant . However, continued killing and eradication were observed only when gatifloxacin AUC/MIC ratios were 27 to 48 . Levofloxacin also provided eradication . In contrast, substantial regrowth was observed in most experiments when gatifloxacin AUC/MIC ratios were 9 to 24 . These data provide further support that fluoroquinolone AUC/MIC ratios of approximately 30 or higher can be sufficient for eradication of pneumococci from IVPMs . Furthermore, the overall impact of the AUC/MIC ratio was not influenced by the strain evaluated or its susceptibility to gatifloxacin . Further studies with other fluoroquinolones and pneumococci that exhibit wider ranges of susceptibilities are warranted . In addition, similar studies with higher peak/MIC ratios are needed to better define the impact of AUC/MIC ratios and peak/MIC ratios on the antipneumococcal pharmacodynamics of fluoroquinolones.

J Soc Gynecol Investig, 2001 Nov-Dec, 8(6), 334 - 40
Production of pro- and anti-inflammatory cytokines of human placental trophoblasts in response to pathogenic bacteria; Griesinger G et al.; OBJECTIVE: We studied the production of cytokines in purified cultures of human term trophoblasts in the presence of pathogenic strains of Escherichia coli, Bacteroides fragilis, Mycoplasma hominis, Staphylococcus aureus, and Streptococcus agalactiae, which have been identified in intrauterine infections . METHODS: Human villous trophoblasts were isolated from term placentas after cesarean section and purified by several steps . After 6, 12, and 24 hours of incubation with the different heat-inactivated bacteria, interleukin-1beta (IL-1beta), interleukin-6 (IL-6), interleukin-8 (IL-8), and interleukin-10 (IL-10) as well as tumor necrosis factor-alpha (TNF-alpha) were measured from supernatants by commercially available enzyme-linked immunosorbent assay . Expression of cytokine mRNAs was determined by semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) . RESULTS: In nonstimulated cultures, low (IL-1beta and TNF-alpha) and high (IL-6, IL-8, and IL-10) basal secretion of cytokines was detectable . The pathogenic microorganisms induced a dose- and time-dependent release of IL-1beta, IL-6, IL-8, and IL-10, whereas TNF-alpha secretion was not elevated . E coli was the most potent inducer followed by B fragilis, S agalactiae, S aureus, and M hominis . Transcripts encoding IL-1beta, IL-6, IL-8, or IL-10 were elevated in the RT-PCR reactions, suggesting that transcriptional mechanisms contribute to elevated cytokine expression . CONCLUSION: Pathogenic microorganisms stimulated mRNA expression and polypeptide release of pro- and anti-inflammatory cytokines from placental trophoblasts . Induction of both inflammation-promoting and inflammation-inhibiting cytokines by bacterial products could play a role in modulating the inflammatory response associated with chorioamnionitis.

FEMS Microbiol Lett, 2001 Dec 18, 205(2), 337 - 42
Characterization of two operons that encode components of fructose-specific enzyme II of the sugar:phosphotransferase system of Streptococcus mutans; Wen ZT et al.; Three genes, designated as fruC, fruD and fruI, were predicted to encode polypeptides homologous to fructose-specific enzyme II (II(Fru)) of the phosphoenolpyruvate-dependent sugar:phosphotransferase system, and were cloned from Streptococcus mutans, the primary etiological agent of human dental caries . The fruC and fruD genes encoded domains BC and domain A of II(Fru), respectively . The fruI gene encoded IICBA(Fru) . Northern hybridization and slot blot analysis showed that expression of fruI was inducible by sucrose and fructose, while fruCD were expressed constitutively and at much lower levels . Inactivation of either fruI or fruCD alone, or of both fruCD and fruI, had no major impact on growth on fructose at a concentration of 0.5% (w/v) . However, when the strains were grown with 0.2% fructose as the sole carbohydrate source, a significant decrease in the growth rate was seen with the fruCD/fruI double mutants . Assays of sugar:phosphotransferase activity showed that the fruCD/fruI double mutants had roughly 30% of the capacity of the wild-type strain to transport fructose via the phosphoenolpyruvate-dependent sugar:phosphotransferase system . Xylitol toxicity assays indicated that the inducible fructose permease was responsible for xylitol transport.

Toxicol Appl Pharmacol, 2001 Dec 15, 177(3), 208 - 18
Correlation of suppressed natural killer cell activity with altered host resistance models in B6C3F1 mice; Wilson SD et al.; A number of methods have been developed to assess the impact of a xenobiotic on the various components of the immune system . For risk analysis, it is necessary to determine what degree of chemically induced immune perturbation translates into altered host resistance . Natural killer (NK) cells play a pivotal role in the innate immune system with the ability to lyse cells infected with intracellular pathogens and certain tumors without previous exposure to the antigen . Spontaneous NK activity in B6C3F1 mice could be incrementally and consistently decreased by 20 to > or =80% by the intravenous administration of a range of dilutions of anti-asialo GM1 (AAGM1) antibody . The decrease in spontaneous NK activity following a single iv administration of AAGM1 antibody persisted for up to approximately 3 weeks when the initial suppression (e.g., 24 h after AAGM1 antibody injection) was almost 100% . Treatment with AAGM1, however, did not appear to perturb the function of other immune cells, based on results of the plaque assay, the mixed lymphocyte response, the cytotoxic T lymphocyte assay, the reticuloendothelial system clearance of sRBC assay, and the Streptococcus pneumoniae host resistance assay . Following a > or =80% decrease in spontaneous NK activity in mice, challenge with > or =1 x 10(3) B16F10 melanoma cells resulted in an increase in tumor burden based on the number of lung nodules . However, following challenge with 1 x 10(5) melanoma cells, a significant increase in tumor burden in mice was not observed until spontaneous NK activity had been decreased by > or =50-60% . Altered host resistance is a function not only of the magnitude of the decrease in NK activity but also of the magnitude of the challenge to the host . (c)2001 Elsevier Science.

Exp Parasitol, 2001 Oct, 99(2), 57 - 65
Plasmodium falciparum cytoadherence to human placenta: evaluation of hyaluronic acid and chondroitin 4-sulfate for binding of infected erythrocytes; Valiyaveettil M et al.; Chondroitin 4-sulfate (C4S) is known to mediate the adherence of Plasmodium falciparum infected red blood cells (IRBCs) to human placenta . Recently, hyaluronic acid (HA) has also been reported to bind IRBCs, and HA has been suggested as an additional receptor for the sequestration of IRBCs in the placenta . In this study, we assessed the adherence of 3D7 parasite strain, which has been reported to bind both C4S and HA, using highly purified clinical grade rooster comb HA, Streptococcus HA, several preparations of human umbilical cord HA (hucHA), and bovine vitreous humor HA (bvhHA) . While all hucHA preparations and bvhHA bound with moderate to high density to IRBCs, the rooster comb and bacterial HAs did not bind IRBCs . IRBCs binding to the hucHA and bvhHA could be abolished by pretreatment with testicular hyaluronidase but not with Streptomyces hyalurolyticus hyaluronidase, suggesting that IRBC binding to hucHA and bvhHA was due to chondroitin sulfate (CS) contaminants in HAs . Compositional analysis confirmed the presence of CS in both hucHA and bvhHA . The CSs present in these commercial hucHA and bvhHA samples were isolated, characterized, and studied for their ability to bind IRBCs . The data suggested that IRBC adherence to hucHA and bvhHA was mediated by the CS present in these samples . However, our data did not exclude the possibility of a minor population of distinct parasite subtype adhering to HA and further studies using pure HA conjugated to proteins or lipids and placental parasite isolates should clarify whether HA is an in vivo receptor for IRBC adherence .

Arch Ophthalmol, 2001 Dec, 119(12), 1755 - 9
Clear corneal wound infection after phacoemulsification; Cosar CB et al.; OBJECTIVE: To evaluate clear corneal wound infections after phacoemulsification . MATERIALS AND METHODS: The medical records of 7 patients with clear corneal wound infections after phacoemulsification were reviewed retrospectively . Data that were reviewed included patient age, sex, onset of symptoms and signs after surgery, possible risk factors for infection, concomitant ocular disease, use of perioperative prophylactic antibiotics and steroids, culture and antibiotic sensitivity results, treatment regimen, and outcome . RESULTS: The median onset of signs and symptoms after surgery was 10 days (range, 4-60 days) . Corneal cultures yielded methicillin-resistant Staphylococcus aureus in 2 cases, Streptococcus pneumoniae in 1 case, and Staphylococcus epidermidis in 1 case . Cultures yielded no microorganisms for 1 patient . Corneal cultures were not obtained in 2 patients . In 3 of the 4 culture-positive cases, the isolated microorganisms were resistant to the perioperative prophylactic antibiotics (fluoroquinolones and tobramycin) that were used . No possible risk factors were noted except use of topical steroids 4 times a day without antibiotic coverage for iritis before referral in one of our patients . Six of these 7 wound infections healed with topical antibiotic therapy . One of the patients required lamellar keratectomy and conjunctival flap for complete healing . In 4 of the 7 cases, best-corrected visual acuity at the last follow-up visit was better than 20/40 . CONCLUSIONS: Clear corneal wound infection after phacoemulsification is a serious complication of cataract surgery . Infections are caused by gram-positive organisms sensitive to bacitracin and the combination of trimethoprim-sulfamethoxazole but often resistant to aminoglycosides and/or fluoroquinolones.

J Antimicrob Chemother, 2001 Dec, 48(6), 915 - 8
Evaluation of PCR primers to screen for Streptococcus pneumoniae isolates and beta-lactam resistance, and to detect common macrolide resistance determinants; Nagai K et al.; Pneumococcal isolates (n = 148) from various countries (mostly from the USA) were tested by a primer set for PCR . Thirty-eight (86.4%) of the 44 penicillin G-susceptible isolates (MIC < or = 0.06 mg/L) had unaltered pbps, while six isolates (13.6%) had either one or two alterations in pbps . Of 47 penicillin G-resistant strains (MIC > or = 2 mg/L), 41 isolates (87.2%) had all three pbps altered, six isolates (12.8%) had altered pbp1a + 2x . Various combinations of altered pbp were seen in penicillin G-intermediate isolates . Prevalence of macrolide resistance genes mef(A) and erm(B) in isolates was clearly reflected by their MICs . All isolates were positive for lytA . The primers were useful for screening for Streptococcus pneumoniae and beta-lactam resistance, and for detection of common macrolide resistance determinants.

J Antimicrob Chemother, 2001 Dec, 48(6), 821 - 6
The pharmacodynamics of gatifloxacin and ciprofloxacin for pneumococci in an in vitro dynamic model: prediction of equiefficient doses; Zinner SH et al.; Enhanced activity against Streptococcus pneumoniae is one of the putative advantages of gatifloxacin over older fluoroquinolones such as ciprofloxacin . This study examined ciprofloxacin and gatifloxacin pharmacodynamics against two differentially susceptible clinical isolates of S . pneumoniae (gatifloxacin MIC, 0.125 and 2 mg/L; ciprofloxacin MIC, 1 and 32 mg/L) . The pharmacokinetics of gatifloxacin (single dose) and ciprofloxacin (two 12 hourly doses) with half-lives of 6 and 5 h, respectively, were simulated using a two-compartment dynamic model . The AUC/MIC ratios in the peripheral compartments that contain bacterial cultures varied over a four- to five-fold range, from 11 to 48 h with ciprofloxacin and from 15 to 78 h with gatifloxacin . The intensity of the antimicrobial effect (IE) increased with increasing AUC/MIC ratios in a strain-independent fashion, although different relationships of IE to log AUC/MIC were inherent for each drug (r2 0.73 for gatifloxacin and r2 0.94 for ciprofloxacin) . Subsequently, the respective dose-response relationships of gatifloxacin and ciprofloxacin for a hypothetical strain of S . pneumoniae with MIC equal to the MIC50 were modelled . Based on these relationships, the equiefficient doses of gatifloxacin and ciprofloxacin were predicted for MIC50S of 0.4 and 1 mg/L, respectively . Gatifloxacin 400 mg was predicted to be equiefficient to ciprofloxacin 1400 mg . To provide the same anti-pneumococcal effect as the usual 1000 mg daily dose of ciprofloxacin, the respective daily dose of gatifloxacin could be as low as 180 mg . This in vitro study demonstrates advantages of gatifloxacin relative to ciprofloxacin in terms of the dose-dependent total antimicrobial effect.

Arch Intern Med, 2001 Nov 26, 161(21), 2538 - 44
A fresh look at the definition of susceptibility of Streptococcus pneumoniae to beta-lactam antibiotics; Musher DM et al.; Definitions for susceptibility or resistance of Streptococcus pneumoniae to penicillin were not developed until penicillin-resistant pneumococci appeared in South Africa in the late 1970s . The definition that was accepted (which still remains in use) and later definitions of resistance to most other beta-lactam antibiotics were derived from laboratory and clinical data relating to the treatment of meningitis, not otitis media, sinusitis, or pneumonia . An understanding of the origin of these definitions helps to resolve the apparent paradox that infections of the respiratory tract due to seemingly beta-lactam-resistant pneumococci may still respond well to standard doses of these drugs . A recently sanctioned change in the definition of susceptibility to amoxicillin is helpful in eliminating the paradox for this drug, but it may create further confusion by implying that, on a microgram basis, amoxicillin is substantially more effective than penicillin or third-generation cephalosporins . This article examines definitions of susceptibility and resistance of pneumococci, highlighting areas that have led to confusion and proposing a new way of understanding them.

J Lab Clin Med, 2001 Nov, 138(5), 338 - 42
Bacterial pathogens of otitis media and sinusitis: detection in the nasopharynx with selective agar media; Dudley S et al.; Carriage rates for the bacterial pathogens associated with otitis media (Streptococcus pneumoniae {SP}, Hemophilus influenzae {HI}, and Moraxella catarrhalis {MC}) are of interest . Culture on three selective agars was compared with culture on two standard agars to determine the more accurate method for detection of these species in the nasopharynx of healthy children . Weekly samples were obtained in winter from 18 healthy children (ages 1 through 9 years) as part of a longitudinal study . A 0.1-mL sample of 116 nasopharyngeal aspirate/washes was inoculated onto each of five agars . Two were standard (sheep blood and chocolate), and three were selective (blood with gentamicin for SP; chocolate with vancomycin, bacitracin, and clindamycin for HI; blood with amphotericin B, vancomycin, trimethoprim, and acetazolamide for MC) . One technician read the standard plates and another the selective; both were blinded to the results of the other . SP was found in 44% of samples with selective agar versus 25% with standard agar; HI was found in 31% with selective versus 9% with standard; MC was found in 56% with selective versus 37% with standard . Overall, 80% of samples had one or more pathogens detected with selective agars as compared with 58% with standard agars (P =.0004) . Selective agars were more accurate than standard agars for detecting otitis pathogens in the nasopharynx, where they are a common part of normal flora in healthy children.

Infect Immun, 2002 Jan, 70(1), 412 - 5
Contribution of choline-binding proteins to cell surface properties of Streptococcus pneumoniae; Swiatlo E et al.; Nonspecific interactions related to physicochemical properties of bacterial cell surfaces, such as hydrophobicity and electrostatic charge, are known to have important roles in bacterium-host cell encounters . Streptococcus pneumoniae (pneumococcus) expresses multiple, surface-exposed, choline-binding proteins (CBPs) which have been associated with adhesion and virulence . The purpose of this study was to determine the contribution of CBPs to the surface characteristics of pneumococci and, consequently, to learn how CBPs may affect nonspecific interactions with host cells . Pneumococcal strains lacking CBPs were derived by adapting bacteria to a defined medium that substituted ethanolamine for choline . Such strains do not anchor CBPs to their surface . Cell surface hydrophobicity was tested for the wild-type and adapted strains by using a biphasic hydrocarbon adherence assay, and electrostatic charge was determined by zeta potential measurement . Adherence of pneumococci to human-derived cells was assessed by fluorescence-activated cell sorter analysis . Strains lacking both capsule and CBPs were significantly more hydrophobic than nonencapsulated strains with a normal complement of CBPs . The effect of CBPs on hydrophobicity was attenuated in the presence of capsule . Removal of CBPs conferred a greater electronegative net surface charge than that which cells with CBPs possessed, regardless of the presence of capsule . Strains that lack CBPs were poorly adherent to human monocyte-like cells when compared with wild-type bacteria with a full complement of CBPs . These results suggest that CBPs contribute significantly to the hydrophobic and electrostatic surface characteristics of pneumococci and may facilitate adherence to host cells partially through nonspecific, physicochemical interactions.

Infect Immun, 2002 Jan, 70(1), 249 - 56
Functional variation of the antigen I/II surface protein in Streptococcus mutans and Streptococcus intermedius; Petersen FC et al.; Although Streptococcus intermedius and Streptococcus mutans are regarded as members of the commensal microflora of the body, S . intermedius is often associated with deep-seated purulent infections, whereas S . mutans is frequently associated with dental caries . In this study, we investigated the roles of the S . mutans and S . intermedius antigen I/II proteins in adhesion and modulation of cell surface characteristics . By using isogenic mutants, we show that the antigen I/II in S . mutans, but not in S . intermedius, was involved in adhesion to a salivary film under flowing conditions, as well as in binding to rat collagen type I . Binding to human fibronectin was a common function associated with the S . mutans and S . intermedius antigen I/II . Adhesion of S . mutans or S . intermedius to human collagen types I or IV was negligible . Hydrophobicity, as measured by water contact angles, and zeta potentials were unaltered in the S . intermedius mutant . The S . mutans isogenic mutants, on the other hand, exhibited more positive zeta potentials at physiological pH values than did the wild type . The results indicate common and species-specific roles for the antigen I/II in mediating the attachment of S . mutans and S . intermedius to host components and in determining cell surface properties.

Infect Immun, 2002 Jan, 70(1), 134 - 9
Long-range mapping of the Streptococcus agalactiae phylogenetic lineage restriction digest pattern type III-3 reveals clustering of virulence genes; Bohnsack JF et al.; Human isolates of serotype III Streptococcus agalactiae (group B streptococcus {GBS}) can be divided into three separate phylogenetic lineages based on analysis of the restriction digest patterns (RDPs) of chromosomal DNA . Nine DNA sequences that are present in all isolates of the RDP III-3 phylogenetic lineage, but not in the other lineages, were identified by genomic subtractive hybridization . A complete physical map of a III-3 chromosome was constructed . Six of the nine III-3-specific sequences mapped to a 340-kb Sse8387I fragment which contains or is located close to known GBS virulence genes . One of the III-3-specific probes, AW-10, encodes part of GBSi1, a group II intron that is inserted at two sites within the GBS genome . The second chromosomal site for GBSi1 was isolated, sequenced, and mapped to a location near the locus responsible for hemolysin production . These findings suggest that the genetic variation that distinguishes the RDP type III-3 strains from other serotype III strains occurs largely within localized areas of the genome containing known or putative virulence genes.

Infect Immun, 2002 Jan, 70(1), 107 - 13
Induction of gamma interferon and nitric oxide by truncated pneumolysin that lacks pore-forming activity; Baba H et al.; Pneumolysin (PLY), an important virulence factor of Streptococcus pneumoniae, is known to exert various effects on the host immune cells, including cytokine induction, in addition to its known cytolytic activity as a member of the thiol-activated cytolysins . It is of interest to determine whether cytolytic activity is involved in triggering the cytokine production . In this study, we constructed full-length recombinant PLY and noncytolytic truncated PLYs with C-terminal deletions to examine the response of spleen cells to these PLY preparations . When cytolytic activity was blocked by treatment with cholesterol, full-length PLY was capable of inducing gamma interferon (IFN-gamma) production . Truncated PLYs that originally exhibited no cytolytic activity were also active in IFN-gamma induction . Therefore, the IFN-gamma-inducing ability of PLY appeared to be independent of the cytolytic activity . Furthermore, IFN-gamma-inducing preparations were also capable of inducing nitric oxide synthase expression and nitric oxide (NO) production, and the addition of neutralizing antibody to IFN-gamma abolished the NO production . These results clearly demonstrated that PLY is capable of inducing IFN-gamma production in spleen cells by a mechanism different from pore formation and that the induced IFN-gamma stimulates NO production . These findings were discussed with reference to the contribution of PLY to the virulence of S . pneumoniae in vivo.

Lancet, 2001 Dec 8, 358(9297), 1975 - 82
Oxazolidinone antibiotics; Diekema DJ et al.; Many common gram-positive pathogens (eg, Staphylococcus aureus, Enterococcus spp, and Streptococcus pneumoniae) have become increasingly resistant to antimicrobial agents, and new drugs with activity against gram-positive bacteria are urgently needed . The oxazolidinones, a new chemical class of synthetic antimicrobial agent, have a unique mechanism of inhibiting bacterial protein synthesis . Linezolid, the first oxazolidinone to be approved for clinical use, displays in-vitro activity (generally bacteriostatic) against many important resistant pathogens, including meticillin-resistant Staph aureus, vancomycin-resistant enterococci, and penicillin-resistant Strep pneumoniae . Linezolid is a parenteral agent that also possesses near-complete oral bioavailability plus favourable pharmacokinetic and toxic effect profiles . Clinical trials confirm the activity of linezolid in the setting of pneumonia, skin and soft-tissue infections, and infections due to vancomycin-resistant enterococci . Linezolid shows promise as an alternative to glycopeptides and streptogramins to treat serious infections due to resistant gram-positive organisms . New agents with greater potency and new spectra of activity could arise from further modification of the oxazolidinone nucleus.

Emerg Infect Dis, 2001 Sep-Oct, 7(5), 906 - 8
Fluoroquinolone resistance among Streptococcus pneumoniae in Hong Kong linked to the Spanish 23F clone; Ho PL et al.; Serotypes 6A/B, 19F, and 23F accounted for 73% of 140 mucosal isolates of Streptococcus pneumoniae from Hong Kong . In pulsed-field gel electrophoresis analysis, a group of related patterns was shared by 14 of 15 ciprofloxacin-resistant and 12 of 16 ciprofloxacin-susceptible isolates . These strains exhibited capsular switching and were highly similar to the Spanish 23F clone.

Emerg Infect Dis, 2001 Sep-Oct, 7(5), 832 - 6
Pneumococcal surface protein A of invasive Streptococcus pneumoniae isolates from Colombian children; Vela Coral MC et al.; Pneumococcal surface protein A (PspA) elicits protection in mice against fatal bacteremia and sepsis caused by genetically diverse pneumococci and protects against carriage and lung infection . We determined the PspA families of invasive isolates of Streptococcus pneumoniae recovered from Colombian children <5 years of age . That 97.5% of Colombian isolates belong to PspA families 1 and 2 supports the hypothesis that a human PspA vaccine covering a few PspA families could be broadly effective.

DNA Cell Biol, 2001 Sep, 20(9), 595 - 601
Expression of Streptococcus mutans wall-associated protein A gene in Chinese hamster ovary cells: prospect for a dental caries DNA vaccine; Han TK et al.; The Streptococcus mutans strain GS-5 wall-associated protein A (Wap-A) is a precursor to the extracellular antigen A (AgA), a recognized candidate dental caries vaccine . The full-length wapA gene (wapA-E) and a C-terminal truncated version (wapA-G) encoding the AgA were cloned into the mammalian expression vector pcDNA 3.1/V5/His-TOPO . The resulting constructs were propagated in the Escherichia coli Top10 . To investigate the expression of the S . mutans genes in mammalian cells, the above constructs were used to transfect Chinese hamster ovary (CHO) cells in the presence of the cationic lipid pfx-8 . Transient expression of the wapA-E and wapA-G genes was observed at 24 h post-transfection, as shown by Western immunoblot analysis using a rabbit antiserum to S . mutans cell wall . Immunochemical staining of the transfected CHO cells showed expression of WapA mainly in the cells and budding vesicles, whereas AgA was found mainly in the transfected cells and extracellular medium . The expression of S . mutans proteins in CHO cells, in either vesicles or soluble form, suggested an antibody response to the above DNA constructs . Work is under way to test the efficacy of these as DNA vaccines against S . mutans.

Biochemistry, 2001 Dec 25, 40(51), 15811 - 23
Kinetic and mechanistic studies of penicillin-binding protein 2x from Streptococcus pneumoniae; Thomas B et al.; High molecular weight penicillin-binding proteins (PBPs) are bifunctional enzymes that build bacterial cell walls from the glycopeptide lipid II {GlcNAc-MurNAc(L-Ala-gamma-D-Glu-L-Lys-D-Ala-D-Ala)-pyrophosphate-undecaprenol} by a process involving disaccharide polymerization and peptide cross-linking . The latter reaction involves acyl-transfer chemistry in which the penultimate (D)Ala first acylates the active-site serine, with release of the terminal (D)Ala, and is then transferred to the epsilon-amine of a Lys on a neighboring pentapeptide chain . These enzymes also catalyze hydrolysis of specific thioester substrates and acylation by beta-lactam antibiotics . In this paper, we explore these latter two reactions and report mechanistic experiments on the reaction of Streptococcus pneumoniae PBP 2x with N-benzoyl-(D)Ala-thioacetic acid {Bz-(D)Ala-(S)Gly} and penicillin G . For these experiments, we used PBP 2x, a soluble form of PBP 2x in which the transmembrane domain was deleted . The following results are significant: (1) pH dependencies for acylation of PBP 2x by penicillin G and Bz-(D)Ala-(S)Gly are identical, suggesting that the same ionizable residues are involved in both reactions and that these residues play the same catalytic role in the two processes . On the basis of these results, we propose a mechanistic model that is also consistent with recently published structural data {Gordon, E., et al . (2000) J . Mol . Biol . 299, 477-485} . (2) Pre-steady-state experiments for the PBP 2x-catalyzed hydrolysis of Bz-(D)Ala-(S)Gly at pH 6.5 indicate that k(c) is principally rate-limited by acylation with some contribution from deacylation . The contribution of these steps to rate limitation is pH-dependent, with acylation entirely rate-limiting at pH values less than 5.5 and deacylation principally rate-limiting above pH 8.5 . (3) Results of solvent isotope effect and proton inventory experiments for acylation suggest a complex process that is at least partially rate-limited by chemistry with some involvement of changes in solvation and/or enzyme conformation . (4) Analysis of activation parameters suggests that during the acylation of PBP 2x by penicillin G the inherent chemical stability of penicillin's amide bond, as manifested in the enthalpy of activation, is offset by a favorable entropy term that reflects penicillin's rotationally constrained bicyclic system, which presumably allows a less energetically demanding entry into the transition state for acylation.

Microb Pathog, 2001 Dec, 31(6), 309 - 17
Comparison of structural changes of cell surface carbohydrates in the eustachian tube epithelium of chinchillas infected with a Streptococcus pneumoniae neuraminidase-deficient mutant or its isogenic parent strain; Tong HH et al.; Six different lectin probes were used to examine alterations of the cell surface carbohydrates in the chinchilla eustachian tube (ET) lumen subsequent to the intranasal (i.n.) challenge with the Streptococcus pneumoniae parent strain, D39, or its isogenic derivative, DeltaNA1, which is deficient in neuraminidase NanA . The labelling pattern revealed that the binding of wheat germ agglutinin (WGA), Erythrina cristagalli lectin (ECL), peanut agglutinin (PNA), Bandeiraea simplicifolia lectin II (BSL II) and succinylated wheat germ agglutinin (SWGA) were increased in the lumenal surface of the ET in the D39 inoculated cohort compared to the uninfected control, which indicated that N-acetylglucosamine (GlcNAc) and D-galactose residues were exposed . Concurrently, decreased labelling with Sambucus nigra agglutinin (SNA) indicated that there were few sialic acid residues remaining in the ET epithelium subsequent to i.n . inoculation with D39 . The DeltaNA1 neuraminidase deficient mutant, however, did not induce any significant changes in the lectin labelling patterns, and was comparable to that of the control cohort . We propose that products of the nanA gene have a significant impact on the changes of the carbohydrate moieties in the ET epithelium and may be responsible for the previously reported increased ability of the D39 parent to colonize the nasopharynx and invade the middle ear .

J Pharm Sci, 2001 Dec, 90(12), 2088 - 98
Microdialysis studies of the middle ear distribution kinetics of amoxicillin in the awake chinchilla; Huang Y et al.; This work was performed to develop an experimental animal model for the study of antibiotic drug distribution into middle ear fluid (MEF) and to evaluate its relevance and significance to the clinical treatment of otitis media (OM) . Chinchillas were assigned to normal or infected ear groups after Eustachian tube obstruction (ETO) or direct trans-bullar inoculation with type 3 Streptococcus pneumoniae . Following survival surgery to implant microdialysis (MD) probes in the jugular vein and middle ear (ME), amoxicillin was given intravenously (iv) as a bolus or infusion . Drug concentrations in blood and MEF were continuously monitored by microdialysis . The measured concentrations were corrected for probe recovery by simultaneous retrodialysis . Multiple MEF and blood sampling was also performed to validate the animal model and MD sampling technique . Bacterial infection was successfully induced 3-7 days after the inoculation, whereas the control group gave negative bacterial culture results . The beta-lactam antibiotic, amoxicillin, exhibited an elimination half-life of 0.33+/-0.23 h (n = 9) in chinchilla blood, 1.46+/-0.50 h (n = 5) and 1.75+/-0.84 h (n = 4) in MEF of normal and infected ears (p = 0.6), respectively . MEF-to-blood amoxicillin concentration ratios at steady state following iv infusion were 0.26+/-0.06 (n = 5) and 0.28+/-0.11 (n = 4) for normal and infected ears (p = 0.7), respectively . MD allows continuous monitoring of drug concentration-time profiles in blood and MEF in an awake chinchilla model . The concentrations measured by MD were validated by direct sampling . The ratio of the area under the curve (AUC) of drug concentration in MEF versus time to that in blood after iv bolus doses was less than unity, as was the steady-state concentration ratio following constant-rate iv infusion, suggesting an active transport mechanism was involved in the efflux of amoxicillin from the ME of chinchilla . The results of studies involving infected ears were not significantly different from those in normal ears in terms of amoxicillin distribution across the ME mucosal membrane after systemic administration .

Biotechnol Bioeng, 2001 Dec, 76(4), 395 - 9
Electric field induced desorption of bacteria from a conditioning film covered substratum; Poortinga AT et al.; Desorption of three oral bacterial strains from a salivary conditioning film on an indium tin oxide electrode during application of a positive (bacterial adhesion to the anode) or a negative electric current was studied in a parallel plate flow chamber . Bacterial adhesion was from a flowing suspension of high ionic strength, after which the bacterial suspension was replaced by a low ionic strength solution without bacteria and currents ranging from -800 to +800 microA were applied . Streptococcus oralis J22 desorbed during application of a positive and negative electric current with a desorption probability that increased with increasing electric current . Two actinomyces strains, however, could not be stimulated to desorb by the electric currents applied . The desorption forces acting on adhering bacteria are electroosmotic in origin and working parallel to the electrode surface in case of a positive current, whereas they are electrophoretic and electrostatic in origin and working perpendicular to the surface in case of a negative current . By comparison of the effect of positive and negative electric currents, it can be concluded that parallel forces are more effective in stimulating bacterial desorption than perpendicular forces . The results of this study point to a new pathway of cleaning industrial and biomedical surfaces without the use of detergents or biocides .

Anim Reprod Sci, 2001 Dec 3, 68(3-4), 229 - 37
The role of international transport of equine semen on disease transmission; Metcalf ES; Despite the numerous benefits of having the capability to transport semen internationally, there are serious potential ramifications if that semen is contaminated with a communicable disease . BACTERIA: Many commensal bacteria colonize the exterior of the stallion penis and are not regarded as pathogenic . They may be cultured from an ejaculate . Alterations of the normal bacterial flora on the exterior genitalia may cause the growth of opportunistic bacteria such as Klebsiella pneumonia, Pseudomonas aeruginosa, Streptococcus zooepidemicus, which, if inseminated, may cause infertility in susceptible mares . Contagious equine metritis (CEM), a highly transmissible, true venereal disease of horses, is caused by the gram-negative coccobacillis, Taylorella equigenitalis . Even with the use of rigorous testing protocols, the current techniques used may not ensure accuracy of results . VIRUSES: Equine coital exanthema (equine herpes virus type 3; EHV-3) is a highly contagious virus that causes painful lesions on the stallion's penis and mare's vulva . Although it is primarily transmitted through coitus, infected fomites have also been implicated in its spread . Therefore, it is possible that the virus can potentially be transmitted to the ejaculate through penile contact with an artificial vagina or sleeve . Equine arteritis virus appears to be becoming more prevalent in recent years . The most common method of transmission is through respiratory disease, but the organism can also be shed in the semen of asymptomatic stallions . Equine infectious anemia virus has also been found to be present in the semen of an infected stallion, although no evidence exists at this time that there is venereal transmission of this disease . PROTOZOA: Dourine, caused by Trympanosoma equiperidum, is a venereal disease found only in Africa, South and Central America and the Middle East . Serological testing using complement fixation is recommended for diagnosis . Piroplasmosis, a disease caused by Babesia equi or by a less severe strain, Babesia caballi, has received a great deal of attention in recent years due to the increased transfer of horses between countries . It is considered to be enzootic in many areas of the southern US, and is found throughout the world . The protozoal agent is most often spread by ticks, but mechanical transmission has also been documented; therefore, there is concern for venereal transmission if blood from an infected horse contaminates the semen.

J Bacteriol, 2002 Jan, 184(1), 126 - 33
Analysis of cis- and trans-acting factors involved in regulation of the Streptococcus mutans fructanase gene (fruA); Wen ZT et al.; There are two primary levels of control of the expression of the fructanase gene (fruA) of Streptococcus mutans: induction by levan, inulin, or sucrose and repression in the presence of glucose and other readily metabolized sugars . The goals of this study were to assess the functionality of putative cis-acting regulatory elements and to begin to identify the trans-acting factors involved in induction and catabolite repression of fruA . The fruA promoter and its derivatives generated by deletions and/or site-directed mutagenesis were fused to a promoterless chloramphenicol acetyltransferase (CAT) gene as a reporter, and strains carrying the transcriptional fusions were then analyzed for CAT activities in response to growth on various carbon sources . A dyadic sequence, ATGACA(TC)TGTCAT, located at -72 to -59 relative to the transcription initiation site was shown to be essential for expression of fruA . Inactivation of the genes that encode fructose-specific enzymes II resulted in elevated expression from the fruA promoter, suggesting negative regulation of fruA expression by the fructose phosphotransferase system . Mutagenesis of a terminator-like structure located in the 165-base 5' untranslated region of the fruA mRNA or insertional inactivation of antiterminator genes revealed that antitermination was not a mechanism controlling induction or repression of fruA, although the untranslated leader mRNA may play a role in optimal expression of fructanase . Deletion or mutation of a consensus catabolite response element alleviated glucose repression of fruA, but interestingly, inactivation of the ccpA gene had no discernible effect on catabolite repression of fruA . Accumulating data suggest that expression of fruA is regulated by a mechanism that has several unique features that distinguish it from archetypical polysaccharide catabolic operons of other gram-positive bacteria.

J Bacteriol, 2002 Jan, 184(1), 119 - 25
Characterization of PauB, a novel broad-spectrum plasminogen activator from Streptococcus uberis; Ward PN et al.; A bovine plasminogen activator of atypical molecular mass ( approximately 45 kDa) from Streptococcus uberis strain SK880 had been identified previously (L . B . Johnsen, K . Poulsen, M . Kilian, and T . E . Petersen . Infect . Immun . 67:1072-1078, 1999) . The strain was isolated from a clinical case of bovine mastitis . The isolate was found not to secrete PauA, a bovine plasminogen activator expressed by the majority of S . uberis strains . Analysis of the locus normally occupied by pauA revealed an absence of the pauA open reading frame . However, an alternative open reading frame was identified within the same locus . Sequence analysis of the putative gene suggested limited but significant homology to other plasminogen activators . A candidate signal peptide sequence and cleavage site were also identified . Expression cloning of DNA encoding the predicted mature protein (lacking signal peptide) confirmed that the open reading frame encoded a plasminogen activator of the expected size, which we have named PauB . Both native and recombinant forms of PauB displayed an unexpectedly broad specificity profile for bovine, ovine, equine, caprine, porcine, rabbit, and human plasminogen . Clinical and nonclinical field isolates from nine United Kingdom sites were screened for the pauB gene and none were identified as carrying it . Similarly, clinical isolates from 20 Danish herds were all found to encode PauA and not PauB . Therefore, PauB represents a novel but rare bacterial plasminogen activator which displays very broad specificity.

J Dent, 2002 Jan, 30(1), 37 - 40
An update on infective endocarditis of dental origin; Tomas Carmona I et al.; OBJECTIVES: The aim of this study was to analyse the prevalence of dental treatment and oral infections related to the development of infective endocarditis (IE) . METHODS: A retrospective study of 103 cases of IE diagnosed from 1997 to 1999 was conducted in Galicia, Spain . RESULTS: According to the Duke's endocarditis criteria (1994), 87 cases (84.5%) were considered definite IE . A presumed oral portal of entry was recorded in 12 patients (13.7%) . Oral infections were held responsible in six cases while the remaining six had received dental treatment in the previous three months (three tooth extractions, one scaling, one cleaning, one fillings) . In eight cases of IE (66.6%) typical oral pathogenic microflora was identified, with Streptococcus viridans being the most frequent . In four patients no previous cardiac disease was recorded . CONCLUSIONS: These results suggest that prevalence and characteristics of IE cases of dental origin did not change significantly in the last decades . The need for increased oral hygiene and improved dental care should be emphasized on preventing IE of dental origin . Continued education of physicians and dentists on the importance of the knowledge of current prophylactic protocols should also be considered.

Clin Infect Dis, 2002 Jan 15, 34(2), 184 - 90 Epub 2001 Dec 05.
Group B Streptococcus colonization in male and nonpregnant female university students: a cross-sectional prevalence study; Bliss SJ et al.; We describe the prevalence of colonization with group B Streptococcus species in a random sample of otherwise healthy male and nonpregnant female college students . Colonization with group B Streptococcus species occurs at a high frequency among healthy students, and there was a suggestion that it is associated with having engaged in sexual activity, tampon use, milk consumption, and hand washing done < or =4 times per day . However, larger studies are needed to verify these findings.

Nature, 2001 Dec 6, 414(6864), 648 - 52
Group A Streptococcus tissue invasion by CD44-mediated cell signalling; Cywes C et al.; Streptococcus pyogenes (also known as group A Streptococcus, GAS), the agent of streptococcal sore throat and invasive soft-tissue infections, attaches to human pharyngeal or skin epithelial cells through specific recognition of its hyaluronic acid capsular polysaccharide by the hyaluronic-acid-binding protein CD44 (refs 1, 2) . Because ligation of CD44 by hyaluronic acid can induce epithelial cell movement on extracellular matrix, we investigated whether molecular mimicry by the GAS hyaluronic acid capsule might induce similar cellular responses . Here we show that CD44-dependent GAS binding to polarized monolayers of human keratinocytes induced marked cytoskeletal rearrangements manifested by membrane ruffling and disruption of intercellular junctions . Transduction of the signal induced by GAS binding to CD44 on the keratinocyte surface involved Rac1 and the cytoskeleton linker protein ezrin, as well as tyrosine phosphorylation of cellular proteins . Studies of bacterial translocation in two models of human skin indicated that cell signalling triggered by interaction of the GAS capsule with CD44 opened intercellular junctions and promoted tissue penetration by GAS through a paracellular route . These results support a model of host cytoskeleton manipulation and tissue invasion by an extracellular bacterial pathogen.

Science, 2001 Dec 7, 294(5549), 2170 - 2
Rapid killing of Streptococcus pneumoniae with a bacteriophage cell wall hydrolase; Loeffler JM et al.; Nasopharyngeal carriage is the major reservoir for Streptococcus pneumoniae in the community . Although eliminating this reservoir would greatly reduce disease occurrence, no suitable intervention has been available for this purpose . We show here that seconds after contact, a purified pneumococcal bacteriophage lytic enzyme (Pal) is able to kill 15 common serotypes of pneumococci, including highly penicillin-resistant strains . In vivo, previously colonized mice revealed undetectable pneumococcal titers 5 hours after a single enzyme treatment . Pal enzyme had little or no effect on microorganisms normally found in the human oropharynx, and Pal-resistant pneumococci could not be detected after extensive exposure to the enzyme.

Microbiology, 2001 Dec, 147(Pt 12), 3311 - 22
The fibrinogen-binding protein (FgBP) of Streptococcus equi subsp . equi additionally binds IgG and contributes to virulence in a mouse model; Meehan M et al.; The major cell-wall-associated protein of the equine pathogen Streptococcus equi subsp . equi is an M-like fibrinogen-binding protein (FgBP) which binds equine fibrinogen (Fg) avidly, through residues located at the extreme N-terminus of the molecule . In this study, it is shown that FgBP additionally binds equine IgG-Fc . When tested against polyclonal IgG from ten other animal species, it was found that FgBP binds human, rabbit, pig and cat IgG, but does not bind mouse, rat, goat, sheep, cow or chicken IgG . Through the use of a panel of recombinant FgBP truncates containing defined deletions of sequence, it was shown that residues in the central regions of FgBP are important in IgG binding . An fbp knockout mutant which does not express FgBP on the cell surface was also constructed . Mutant cells failed to autoaggregate, bound no detectable equine Fg or IgG-Fc, were rapidly killed in horse blood, and showed greatly decreased virulence in a mouse model . Results suggest that FgBP is the major surface structure responsible for binding either Fg or IgG, that the molecule has pronounced antiphagocytic properties, and that it is a likely factor contributing to the virulence of wild-type S . equi subsp . equi.

Prim Care, 2001 Dec, 28(4), 791 - 806, vi-vii
Maternal vaccines; Glezen WP; Acute lower respiratory illness (LRI) is the leading cause of disease worldwide as measured by disability-adjusted life years . New strategies are necessary to decrease the disease burden that is largely borne by infants . Respiratory syncytial virus is the most important cause of LRI in infants . Lower respiratory illness can be prevented by endowing infants with high levels of neutralizing antibodies from mothers whose antibodies are boosted during pregnancy with a potent subunit vaccine . Another important cause of infant mortality is group B streptococcus sepsis in the neonatal period; maternal immunization with a group B conjugate vaccine could prevent this devastating infection.

Vaccine, 2001 Dec 12, 20(5-6), 805 - 12
PsaA (pneumococcal surface adhesin A) and PspA (pneumococcal surface protein A) DNA vaccines induce humoral and cellular immune responses against Streptococcus pneumoniae; Miyaji EN et al.; Streptococcus pneumoniae is one of the most important human pathogens and improvement of the currently used polysaccharide vaccines is being pursued . We constructed DNA vaccine vectors containing either the full-length psaA (pneumococcal surface adhesin A) or a truncated pspA (pneumococcal surface protein A--pspA') gene . Both constructs showed transient expression of the antigens in vertebrate cells and induced significant antibody response to the pneumococcal antigens in BALB/c mice injected intramuscularly (i.m.) . Fusion with an N-terminal cytoplasmatic SV40 T-antigen (CT-Ag), which was previously shown to stabilize poorly expressed antigens through association with Hsp73, also induced anti-PspA antibody response . The induction of antibodies with a low IgG1:IgG2a ratio and elevated gamma interferon (IFN-gamma) production by spleen cells elicited by DNA vaccination indicate preferential priming of Th1 immunity . Since induction of antibodies against both PsaA and PspA was previously shown to correlate with protection against fatal infection with S . pneumoniae and cell-mediated immune responses could contribute to protection, further evaluation of PsaA and PspA as antigens for a DNA vaccine against S . pneumoniae could be promising.

Int J Antimicrob Agents, 2001 Dec, 18(6), 553 - 7
In vitro antimicrobial activity of a chitooligosaccharide mixture against Actinobacillus actinomycetemcomitans and Streptococcus mutans; Choi BK et al.; The purpose of this study was to evaluate the in vitro antibacterial activity of a chitooligosaccharide mixture (MW 2000-30000 Da) with a deacetylation degree of 91.5% against two representative oral pathogens, Actinobacillus actinomycetemcomitans and Streptococcus mutans . A 0.1% concentration of the chitooligosaccharides (derived from the exoskeletons of marine crustaceans) was used to estimate antibacterial activity . Approximately 2 logcolony forming units (CFU)/ml of A . actinomycetemcomitans were inactivated by 0.1% chitosan after 30 min, while 120 min exposure inactivated about 4.5 logCFU/ml of this organism . In contrast, the level of inactivation against S . mutans was less than 0.5 logCFU/ml after an exposure of up to 120 min . Electron microscopy showed that the exposure of A . actinomycetemcomitans to the chitooligosaccharides resulted in the disruption of cell membranes and that it could be considered for the treatment of periodontal diseases associated with A . actinomycetemcomitans.

Int J Antimicrob Agents, 2001 Dec, 18(6), 531 - 5
In vitro activity of ABT-773, telithromycin and eight other antimicrobials against erythromycin-resistant Streptococcus pneumoniae respiratory isolates of children; Johnson CN et al.; The activity of the ketolide ABT-773 against 180 erythromycin-resistant Streptococcus pneumoniae obtained from children was compared with telithromycin, azithromycin, clarithromyin, roxithromycin, clindamycin, penicillin, levofloxacin and gatifloxacin . Ketolide MICs were all < or =1 mg/l, with ABT-773 being the most potent of all drugs tested . MIC(90)s for macrolides and azithromycin in mefE+ isolates were 16-32 compared with >128 mg/l for ermB+ isolates . ABT-773 and telithromycin MIC(90)s for mefE+ isolates were 0.125 and 0.5, compared with 0.032 and 0.016 mg/l for ermB+ isolates and 0.5 and 1 mg/l, respectively, for isolates containing both genes . Clindamycin was active against mefE+ but not ermB+ isolates . 155 isolates were resistant to penicillin . All fluoroquinolone MICs were < 1 mg/l . Further studies of ketolides for treatment of paediatric S . pneumoniae infections are warranted.

Mol Microbiol, 2001 Nov, 42(4), 1035 - 45
Constitutive competence for genetic transformation in Streptococcus pneumoniae caused by mutation of a transmembrane histidine kinase; Lacks SA et al.; Competence for DNA uptake and genetic transformation in Streptococcus pneumoniae is regulated by a quorum-sensing system . A competence-stimulating polypeptide (CSP) is secreted by the bacteria and acts back on the cells via a transmembrane histidine kinase . This enzyme phosphorylates a response regulator that activates synthesis of a SigH-like protein . The new sigma factor enables expression of a set of proteins transcribed from a novel promoter . A mutation called trt had been found that circumvented this regulation . The mutant cells are constitutively competent; that is, they can be transformed at low cell densities, in the presence of proteases that attack CSP, or during growth at low pH . In this work, cells containing trt were shown to be competent even in the presence of a comAB mutation that blocks secretion of CSP . The trt mutation was localized to comD, the gene encoding the transmembrane histidine kinase . A DNA segment of the trt mutant corresponding to comCDE was cloned, and it was shown to contain the trt mutation by its ability to confer constitutive competence . A two-step assay, which was based on transfer of trt to a wild strain and screening for transformability in the presence of trypsin, served to locate the trt mutation precisely . It corresponds to a GC-->AT transition, which changes Asp299 in the histidine kinase to Asn . This alteration in the carboxyl terminal half of the protein, which is cytoplasmically located and contains the phosphorylase activity, presumably alters the enzyme conformation so that it is permanently activated, independent of signals from the transmembrane domain . These results may help illuminate the mechanism by which external signals affect kinase action in two-component regulatory systems, and they may be of practical value in facilitating genetic studies by rendering pneumococcal strains permanently competent.

Clin Oral Implants Res, 2001 Dec, 12(6), 543 - 51
Plaque formation on surface modified dental implants . An in vitro study; Grossner-Schreiber B et al.; Bacterial adhesion on titanium implant surfaces has a strong influence on healing and long-term outcome of dental implants . Parameters like surface roughness and chemical composition of the implant surface were found to have a significant impact on plaque formation . The purpose of this study was to evaluate the influence of two physical hard coatings on bacterial adhesion in comparison with control surfaces of equivalent roughness . Two members of the oral microflora, Streptococcus mutans and Streptococcus sanguis were used . Commercially pure titanium discs were modified using four different surface treatments: physical vapour deposition (PVD) with either titanium nitride (TiN) or zirconium nitride (ZrN), thermal oxidation and structuring with laser radiation . Polished titanium surfaces were used as controls . Surface topography was examined by SEM and estimation of surface roughness was done using a contact stylus profilometer . Contact angle measurements were carried out to calculate surface energy . Titanium discs were incubated in the respective bacterial cell suspension for one hour and single colonies formed by adhering bacteria were counted by fluorescence microscopy . Contact angle measurements showed no significant differences between the surface modifications . The surface roughness (Ra) of all surfaces examined was between 0.14 and 1.00 microm . A significant reduction of the number of adherent bacteria was observed on inherently stable titanium hard materials such as TiN and ZrN and thermically oxidated titanium surfaces compared to polished titanium . In conclusion, physical modification of titanium implant surfaces such as coating with TiN or ZrN may reduce bacterial adherence and hence improve clinical results.

Drugs, 2001, 61(14), 2065 - 77
Responsible prescribing for upper respiratory tract infections; Turnidge J; Upper respiratory tract infections (URTIs) are responsible for a large amount of community antibacterial use worldwide . Recent systematic reviews have demonstrated that most URTIs resolve naturally, even when bacteria are the cause . The high consumer expectation for antibacterials in URTIs requires intervention by the general practitioner and a number of useful strategies have been developed . Generic strategies, including eliciting patient expectations, avoiding the term 'just a virus', providing a value-for-money consultation, providing verbal and written information, empowering patients, conditional prescribing, directed education campaigns, and emphasis on symptomatic treatments, should be used as well as discussion of alternative medicines when relevant . The various conditions have differing rates of bacterial infection and require different approaches . For acute rhinitis, laryngitis and tracheitis, viruses are the only cause and, therefore, antibacterials are never required . In acute sore throat (pharyngitis) Streptococcus pyogenes is the only important bacterial cause . A scoring system can help to increase the likelihood of distinguishing a streptococcal as opposed to viral infection, or alternatively patients should be given antibacterials only if certain conditions are fulfilled . Strategies for treating acute otitis media vary in different countries . Most favour the strategy of prescribing antibacterials only when certain criteria are fulfilled, delaying antibacterial prescribing for at least 24 hours . In otitis media with effusion, on the other hand, there is no primary role for antibacterials, as the condition resolves naturally in almost all patients aged >3 months . Detailed strategies for acute sinusitis have not been worked out but restricting antibacterial prescribing to certain clinical complexes is currently recommended by several authorities because of the high natural resolution rate.

Pediatr Infect Dis J, 2001 Sep, 20(9), 879 - 84
Population-based active surveillance for neonatal group B streptococcal infections in Alberta, Canada: implications for vaccine formulation; Davies HD et al.; BACKGROUND: Knowledge of circulating serotypes of group B Streptococcus (GBS) is important for formulation of vaccines . There are no Canadian data on the serotype distribution of neonatal GBS isolates . METHODS: Using a retrospective laboratory and health record survey between 1993 and 1994 (before introduction of Canadian prevention guidelines) and prospective active laboratory-based surveillance from 1995 to 1999 of all laboratories in Alberta, we identified 168 cases of invasive neonatal GBS infections including stillbirths among 262,398 total births; 118 of 123 (96%) isolates from 1995 to 1999 were serotyped, and the corresponding neonatal health records were reviewed . RESULTS: The average annual incidence was 0.64 of 1000 total births/year . Of these 95 (57%) had early onset disease (EOD), 15 (9%) were still births and 58 (34%) had late onset disease (LOD) . Eighty-one percent of EOD cases were caused by serotypes Ia, Ia/c, Ia/c/R, III, III/R and V, V/R, whereas 81% of LOD cases were caused by serotypes III and III/R . GBS serotypes containing the C protein along with serotypes III and V as a group constituted 91% (107 of 118) of all GBS cases in our population . The most common clinical presentation was bacteremia without focus (74%) followed by meningitis (14%) and pneumonia (12%) . During 1995 to 1999, in addition to 13 stillbirths, there were 6 of 64 (9%) neonatal deaths among EOD cases and 1 of 46 (2%) neonatal death among LOD cases . CONCLUSIONS: In this population-based study stillbirths account for a proportion of cases that are not routinely counted and represent a group for which intrapartum antibiotics would likely not be effective, but potentially preventable by vaccination . Inclusion of serotypes Ia, III and V in a conjugate vaccine or serotypes III and V conjugated with the C protein in a GBS vaccine could theoretically provide protection against the majority of GBS invasive disease in Alberta neonates.

Pediatr Infect Dis J, 2001 Sep, 20(9), 863 - 8
High prevalence of erythromycin resistance of Streptococcus pyogenes in Greek children; Syrogiannopoulos GA et al.; BACKGROUND: Macrolide resistance among Streptococcus pyogenes strains is increasing in many European countries . Greece was not considered a country with high prevalence of macrolide-resistant S . pyogenes strains, and until now the genetic mechanism of resistance was unknown . METHODS: During the 25-month period from December, 1998, to December, 2000, pharyngeal cultures for S . pyogenes were performed on 743 Greek children with the clinical diagnosis of pharyngitis . The children were 1 to 16 years old (median age, 7 years) and were living in Central and Southern Greece . S . pyogenes isolates were tested for their susceptibility to erythromycin, clarithromycin, azithromycin, clindamycin, penicillin G, amoxicillin/clavulanate and cefprozil . The erythromycin-resistant isolates were further studied for their genetic mechanism of resistance by means of PCR . RESULTS: Of a total of 275 S . pyogenes isolates recovered, 105 (38%) were erythromycin-resistant (MIC > or = 1 microgram/ml) {corrected}, with 54, 45 and 1% of them carrying mef(A), erm(A) {subclass erm(TR)} and erm(B) gene, respectively . The prevalence of erythromycin-resistant strains was 29 and 42% during the time periods December, 1998, to December, 1999, and January, 2000, to December, 2000, respectively . All erythromycin-resistant isolates were also resistant to clarithromycin and azithromycin . The isolates carrying the erm(A) gene were inducibly resistant to clindamycin . The 275 S . pyogenes isolates had ceprozil MICs < or = 0.032 microgram/ml . CONCLUSIONS: The current high (38%) prevalence of erythromycin-resistant S . pyogenes in Central and Southern Greece requires continuous surveillance and careful antibiotic policy.

Pediatr Infect Dis J, 2001 Nov, 20(11), 1092 - 4
Early onset pneumococcal sepsis in children hospitalized for noninfectious life-threatening events; Yagupsky P et al.; During a 13-year period 9 patients admitted to a pediatric intensive care unit for life-threatening noninfectious conditions developed pneumococcal sepsis within 48 h of admission . All patients were Bedouins, a population group characterized by high prevalence of respiratory carriage of Streptococcus pneumoniae . In populations with high carriage rates of S . pneumoniae, critically ill children appear to be at increased risk of pneumococcal sepsis.

J Mol Biol, 2001 Dec 7, 314(4), 789 - 96
Crystal structure of omega transcriptional repressor encoded by Streptococcus pyogenes plasmid pSM19035 at 1.5 A resolution; Murayama K et al.; The 71 amino acid residue omega protein encoded by the Streptococcus pyogenes non-conjugative plasmid pSM19035 is a transcriptional repressor that regulates expression of genes for copy number control and stable maintenance of plasmids . The crystal structure of omega protein has been determined by multiple isomorphous replacement, including anomalous scattering and refined to an R-factor of 21.1 % (R(free)=23.2 %) at 1.5 A resolution . Two monomers related by a non-crystallographic 2-fold axis form a homodimer that occupies the asymmetric unit . Each polypeptide chain is folded into two alpha-helices and one beta-strand forming an antiparallel beta-ribbon in the homodimer . The N-terminal regions (1-23 and 1-22 in subunits I and II, respectively) are not defined in the electron density due to proteolysis of the N-terminal 20 amino acid residues during crystallisation and partial disorder . The omega protein belongs to the structural superfamily of MetJ/Arc repressors featuring a ribbon-helix-helix DNA-binding motif with the beta-ribbon located in and recognizing the major groove of operator DNA; according to a modelled omega protein-DNA complex, residues Arg31 and Arg31' on the beta-ribbon are in positions to interact with a nucleobase, especially guanine .

Am J Perinatol, 2001 Dec, 18(8), 451 - 8
Relationship between fetal pulmonary maturity assessment and neonatal outcome in premature rupture of the membranes at 32-34 weeks' gestation; Refuerzo JS et al.; The absence of fetal pulmonary maturity in patients with preterm premature rupture of the membranes (PPROM) is often considered an indication for conservative management . The purpose of this study was to examine the value of biochemical pulmonary maturity assessment for the prediction of neonatal outcome in patients with PPROM between 32 and 34 weeks' gestation . Pregnancies complicated by PPROM at 32 to 34 weeks' gestation that delivered from January 1995 to May 2000 and had biochemical pulmonary maturity assessment were reviewed . Patients with medical disorders, multiple gestations, fetal growth restriction or structural anomalies, or evidence of intra-amniotic infection were excluded . Neonatal outcome measures were compared between patients with mature and immature pulmonary indices . During this time period, 244 patients with PPROM at 32-34 weeks' gestation were delivered; 78 patients met inclusion criteria (n = 41 patients with mature indices and n = 37 patients with immature indices) . There were no cases of perinatal death or sepsis . There was no difference in major neonatal morbidities including need for mechanical ventilation, grade 2 or 3 necrotizing enterocolitis, grade 3 or 4 intraventricular hemorrhage, or seizures . After controlling for confounding factors including gestational age at PPROM and delivery, latency period, group B streptococcus (GBS) vaginal colonization, corticosteroid therapy, neonatal sex, mode of delivery, fetal indications for delivery, and umbilical cord pH, biochemical pulmonary maturity was not predictive of major neonatal morbidity . In our population, biochemical pulmonary maturity status does not appear to be predictive of neonatal morbidity in pregnancies complicated by PPROM at 32-34 weeks' gestation.

J Antimicrob Chemother, 2001 Dec, 48(6), 907 - 9
Influence of the decrease in ciprofloxacin susceptibility and the presence of human serum on the in vitro susceptibility of Streptococcus pneumoniae to five new quinolones; Balcabao IP et al.; Sixty recent Streptococcus pneumoniae isolates with different susceptibilities to ciprofloxacin (14 with MIC 0.5 mg/L, 10 with MIC 1 mg/L, eight with MIC 2 mg/L, 11 with MIC 4 mg/L and 17 with MIC > or =8 mg/L) were tested against five new quinolones using Todd-Hewitt broth with and without 80% serum . The final inoculum was 5 x 10(5) cfu/mL . Gemifloxacin and clinafloxacin exhibited the lowest MIC90 values and resistance rates (percentage above and defined breakpoint) with and without serum for strains with a ciprofloxacin MIC of > or =4 mg/L . Other quinolones tested were less active against strains with reduced ciprofloxacin susceptibility . The presence of serum did not affect susceptibility to moxifloxacin, but increased the resistance rates to other new quinolones for strains with high ciprofloxacin MICs.

Clin Infect Dis, 2002 Jan 1, 34(1), 15 - 21 Epub 2001 Nov 20.
Geographic, demographic, and seasonal differences in penicillin-resistant Streptococcus pneumoniae in Baltimore; Albanese BA et al.; We examined the epidemiology of invasive penicillin-resistant Streptococcus pneumoniae (PRSP) infections among residents of the Baltimore metropolitan area from 1995 through 1997 . During this period, the proportion PRSP cases increased 42%, from 5.7% to 8.1% of cases . PRSP rates were highest among persons aged <5 and > or =65 years, black patients, and urban dwellers . However, the proportion of PRSP cases was higher among white persons (10%) than it was among black persons (5%) and among residents of suburban counties (10%) versus urban counties (6%) . PRSP cases were more common in November-April (8%) than they were in May-October (5%), particularly for persons aged > or =65 years (10% vs . 1%) . By use of logistic regression, white race, suburban residence, and winter respiratory season were found to be independent predictors of infection with PRSP . The incidence of PRSP is increasing in Baltimore, and the seasonality of PRSP suggests that recent antibiotic use, which is more common in winter months, may rapidly affect the prevalence of resistant pneumococcal infections.

Vet Microbiol, 2002 Jan 3, 84(1-2), 155 - 68
Assessment of protective efficacy of live and killed vaccines based on a non-encapsulated mutant of Streptococcus suis serotype 2; Wisselink HJ et al.; The protective efficacy of a live and killed non-encapsulated isogenic mutant of Streptococcus suis serotype 2 was determined in pigs, and compared with the efficacy of the capsulated wild-type strain . SPF pigs were vaccinated twice intramuscularly at 4 and 7 weeks of age with a dose of 1 x 10(9) formalin-killed CFU of the wild-type (WT-BAC), formalin-killed non-encapsulated mutant (CM-BAC) or live non-encapsulated mutant (CM-LIVE) strain . After 2 weeks, vaccinated pigs and non-vaccinated controls were challenged intravenously with 1 x 10(7) CFU of the homologous, wild-type S . suis serotype 2 strain . Protection was evaluated by clinical, bacteriological, serological and post-mortem examinations . All pigs vaccinated with WT-BAC were completely protected against challenge with the homologous serotype . Pigs vaccinated with CM-BAC were partially protected . Although all pigs vaccinated with CM-BAC survived the challenge, four out of five pigs developed clinical signs of disease for several days . Compared to the WT-BAC and CM-BAC, the CM-LIVE vaccine was less protective . Two out of five pigs vaccinated with CM-LIVE died in the course of the experiment and all of them developed specific clinical signs of disease for several days . The protective efficacy of the vaccines could be associated with serum antibody titers . Antibody titers against cells of wild-type and non-encapsulated mutant strains as well as against muramidase-released proteins (MRP) were high in pigs vaccinated with WT-BAC and CM-BAC . Pigs vaccinated with CM-LIVE showed lower antibody titers . Antibody titers against purified capsular polysaccharides (CPS) of S . suis serotype 2 were only found in pigs vaccinated with WT-BAC . These findings indicate that CPS and other bacterial components of WT-BAC are probably essential for full protection against homologous challenge.

Am Surg, 2001 Nov, 67(11), 1089 - 92
Group A Streptococcus (GAS) soft-tissue infections: a lethal organism on the rise; Bochicchio GV et al.; Several reports over the past decade have suggested that there has been an increase in the number of invasive streptococcal infections with young children and the elderly being at the highest risk . We evaluated the incidence of group A Streptococcus (GAS) and compared it with historic data collected at our institution . Prospective data were collected on patients diagnosed with GAS (with and without shock) admitted to a tertiary-care center from July 1995 to July 2000 . Each patient was followed by an infectious disease specialist throughout the hospital stay . Definitions of streptococcal toxic shock syndrome (STSS) developed by the Centers for Disease Control and Prevention were used . Thirty-eight patients (mean age of 39+/-12) presenting with GAS soft-tissue infections were admitted to our institution over a 5-year period (7.6 patients per year) . Fourteen (37%) were diagnosed with STSS . This represents a greater than fourfold increase in the average number of cases per year of patients diagnosed with GAS and a nearly 4.5 times greater increase in the annual number of patients diagnosed with STSS . The overall mortality of patients diagnosed with GAS was 13 per cent, which increased to 36 per cent in patients diagnosed with STSS . We conclude that there has been a significant increase in the incidence of GAS soft-tissue infections over the past 5 years at our institution . This may represent a new virulent strain, as the majority of these infections did not occur in typical high-risk patients at the extremes of their lives . Further epidemiologic population-based studies are needed to further delineate the severe nature of this problem.

Nihon Kokyuki Gakkai Zasshi, 2001 Sep, 39(9), 672 - 7
{Invasive pulmonary aspergillosis following influenza A infection}; Matsushima H et al.; A 55-year-old man with arc welder's pneumoconiosis who presented with bilateral pneumonia was admitted to our hospital . Streptococcus pneumoniae and Aspergillus fumigatus were cultured from sputum on admission . The patient was treated with antibiotics and an anti-fungal agent, but his chest radiograph shadows became exacerbated, and he died of respiratory failure on the fourth day of hospitalization . Histological examination of postmortem lung tissue revealed necrotizing aspergillous pneumonia . The results of hemagglutination inhibition tests for influenza A (H3 N2) were x16 in September 1999, and x512 on the third day of hospitalization . We diagnosed this patient's condition as invasive pulmonary aspergillosis associated with influenza A viral infection . The suppression of cellular immunity, lymphocytopenia, and destruction of airways-mucociliary transport induced by influenza A viral infection were suspected to have predisposed him to aspergillus superinfection.

Chin Med J (Engl), 2001 Nov, 114(11), 1196 - 200
Nasal carriage of Streptococcus pneumoniae among children in Beijing; Li J et al.; OBJECTIVE: To investigate the antimicrobial susceptibility of Streptococcus pneumoniae carried in the nose among children in Beijing and the distribution of serotypes, and to analyze the risk factors for nasal carriage of penicillin non-susceptible S . pneumoniae . METHODS: A disk diffusion test was applied to detect the antimicrobial susceptibilities of S . pneumoniae to erythromycin, trimethoprim-sulfamethoxazole, chloramphenicol and tetracycline . The E test was applied to determine the minimal inhibitory concentrations of penicillin, cefuroxime, cefotaxime, augmentin and imipenem . S . pneumoniae isolates were serotyped by the Quellung reaction . RESULTS: S . pneumoniae that was resistant to penicillin or cefuroxime was not found, but S . pneumoniae intermediate resistant to penicillin and cefuroxime accounted for 8.2% and 2.1%, respectively . All of the isolates were susceptible to cefotaxime, augmentin and imipenem . S . pneumonia that was resistant to erythromycin, trimethoprim-sulfamethoxazole and tetracycline were extremely numerous, accounting for 72%, 70% and 79%, respectively . Five serotypes (19, 6, 14, 23, 17) accounted for 54.7%, and nontypables accounted for 20.6% of all the S . pneumoniae . Previous history of otitis media was a risk factor we found for nasal carriage of penicillin non-susceptible S . pneumoniae . CONCLUSIONS: Continued surveillance of the antimicrobial susceptibilities of S . pneumoniae is necessary . A larger scale investigation is needed to identify if the 7 or 9-valent conjugate pneumococcal vaccine is appropriate for Chinese children.

FEMS Microbiol Lett, 2001 Nov 27, 205(1), 99 - 104
The cell wall-associated serine protease PrtA: a highly conserved virulence factor of Streptococcus pneumoniae; Bethe G et al.; The surface-associated subtilisin-like serine protease PrtA was identified by screening a genomic expression library from Streptococcus pneumoniae using a convalescent-phase serum . In Western blot analysis two forms of PrtA were detected in whole cell lysate and a truncated form only in culture supernatant suggesting that PrtA is produced as a precursor protein, translocated to the cell surface, truncated, and released into the surroundings . A 5' fragment of the gene was found highly conserved among 78 pneumococcal isolates of clinical relevance . Immunogenicity of PrtA, limited genetic variation, and the involvement in pneumococcal virulence demonstrated in in vivo experiments might identify PrtA as a promising candidate for a protein based vaccine.

Scand J Infect Dis, 2001, 33(10), 772 - 4
Propensity of Streptococcus pneumoniae for the aorta . Report of 3 cases; Steig TA et al.; Streptococcus pneumoniae was the unsuspected cause of a ruptured aortic aneurysm in 3 patients, as confirmed by culture of specimens obtained during surgery . A 60-y-old woman had a recently diagnosed saccular aortic aneurysm and presented with symptoms indicating a vascular catastrophe . A 66-y-old man and a 69-y-old woman were both admitted with pyrexia and abdominal pain and proper diagnosis was delayed for 4 and 15 d, respectively . All 3 patients were treated with graft insertion and antibiotic therapy for 3 months and recovered fully.

Scand J Infect Dis, 2001, 33(10), 771 - 2
Descending necrotizing mediastinitis caused by group A streptococcus (serotype M1T1); Callister ME et al.; We present a fatal case of descending necrotizing mediastinitis secondary to group A Streptococcus (serotype M1T1) . Group A Streptococcus is a well-described cause of necrotizing fasciitis, but there have only been 4 previous cases documenting its involvement in descending necrotizing mediastinitis . This is the first case report to describe involvement of the M1 serotype in this condition.

Nat Med, 2001 Dec, 7(12), 1298 - 305
Evasion of human innate and acquired immunity by a bacterial homolog of CD11b that inhibits opsonophagocytosis; Lei B et al.; Microbial pathogens must evade the human immune system to survive, disseminate and cause disease . By proteome analysis of the bacterium Group A Streptococcus (GAS), we identified a secreted protein with homology to the alpha-subunit of Mac-1, a leukocyte beta2 integrin required for innate immunity to invading microbes . The GAS Mac-1-like protein (Mac) was secreted by most pathogenic strains, produced in log-phase and controlled by the covR-covS two-component gene regulatory system, which also regulates transcription of other GAS virulence factors . Patients with GAS infection had titers of antibody specific to Mac that correlated with the course of disease, demonstrating that Mac was produced in vivo . Mac bound to CD16 (FcgammaRIIIB) on the surface of human polymorphonuclear leukocytes and inhibited opsonophagocytosis and production of reactive oxygen species, which resulted in significantly decreased pathogen killing . Thus, by mimicking a host-cell receptor required for an innate immune response, the GAS Mac protein inhibits professional phagocyte function by a novel strategy that enhances pathogen survival, establishment of infection and dissemination.

Cancer Immunol Immunother, 2001 Oct, 50(8), 408 - 16
Enhancement of anti-cancer immunity by a lipoteichoic-acid-related molecule isolated from a penicillin-killed group A Streptococcus; Okamoto M et al.; We isolated the lipoteichoic-acid-related molecule (OK-PSA) from OK-432, a streptococcal preparation, by affinity chromatography on CNBr-activated Sepharose-4B-bound monoclonal antibody TS-2, which neutralizes the interferon (IFN)-gamma-inducing activity of OK-432 . We have previously reported that OK-PSA is a potent inducer of Th1-type cytokines in human peripheral blood mononuclear cells in vitro . In this study, we conducted an animal experiment to examine whether OK-PSA exhibits an anti-tumor effect in vivo by acting as a Th1 inducer in syngeneic Meth-A tumor-bearing BALB/c mice, in which the Th2 response is genetically dominant . It was found that OK-PSA induced Th1-type cytokines {IFN-gamma, tumor necrosis factor-alpha, interleukin (IL)-2, IL-12 and IL-18} in BALB/c mice bearing Meth-A tumor and caused a marked anti-tumor effect . Although it was suggested by an in vitro study . using spleen cells derived from the animals, that IL-18 plays the greatest role in the induction of the Th1-dominant state and tumor cell killing induced by OK-PSA, the in vivo experiments demonstrated that both IL-12 and IL-18 are essential in the anti-tumor effect exhibited by OK-PSA . These findings strongly suggest that OK-PSA is a major effector molecule of OK-432 and may be a useful immunotherapeutic agent, as a potent Th1 inducer, for cancer patients with a Th2-dominant state.

Proc Natl Acad Sci U S A, 2001 Dec 4, 98(25), 14577 - 82 Epub 2001 Nov 27.
Complement activation in factor D-deficient mice; Xu Y et al.; To assess the contribution of the alternative pathway in complement activation and host defense and its possible role in the regulation of systemic energy balance in vivo, factor D-deficient mice were generated by gene targeting . The mutant mice have no apparent abnormality in development and their body weights are similar to those of factor D-sufficient littermates . Complement activation could not be initiated in the serum of deficient mice by the alternative pathway activators rabbit erythrocytes and zymosan . Surprisingly, injection of cobra venom factor (CVF) caused a profound and reproducible reduction in serum C3 levels, whereas, as expected, there was no C3 reduction in factor B-deficient mice treated similarly . Studies of C3 and factor B activation in vitro by CVF demonstrated that in factor D-deficient serum the alpha chain of C3 was cleaved gradually over a period of 60 min without detectable cleavage of factor B . CVF-dependent C3 cleavage in the deficient serum required the presence of Mg(2+), whereas in normal mouse serum the presence of divalent cations was not required . These results suggest that in mouse proteolytic cleavage of factor B by factor D is not an absolute requirement for the zymogen to active enzyme conformational transition of CVF-bound factor B . Kinetics of opsonization of Streptococcus pneumoniae by C3 fragments was much slower in factor D-deficient serum, suggesting a significant contribution of the alternative pathway to antibacterial host defense early after infection.

J Clin Microbiol, 2001 Dec, 39(12), 4526 - 8
Clonal relationship between U.S . and French serotype V group B streptococcus isolates; Le Thomas-Bories I et al.; We examined the genetic diversity of serotype V group B streptococcus (GBS) isolates in the Paris area and compared them with the predominant American serotype V clone . Pulsed-field gel electrophoresis yielded 11 patterns for 64 French GBS . One pattern was obtained with 60% of the isolates tested and was indistinguishable from that of the predominant American clone.

Am J Epidemiol, 2001 Dec 1, 154(11), 1000 - 5
Evaluation of innovative surveillance for drug-resistant Streptococcus pneumoniae; Perz JF et al.; To monitor disease incidence and antibiotic resistance, effective, practical surveillance strategies are needed at the local level for drug-resistant Streptococcus pneumoniae (DRSP) . Knox County, Tennessee, participates in three forms of DRSP surveillance: an active system sponsored by the Centers for Disease Control and Prevention (CDC; Atlanta, Georgia); a novel county-sponsored system; and conventional state-mandated reporting . Ascertainment of invasive S . pneumoniae infection cases by each system in 1998 was evaluated, and completeness of reporting, antibiotic resistance patterns, costs, and other attributes were compared . The county-sponsored system collects patient identifiers and drug susceptibility data directly from hospital laboratories, whereas the CDC-sponsored system performs medical chart abstractions and reference laboratory susceptibility testing . Similar numbers of invasive S . pneumoniae cases were detected by the county-sponsored (n = 127) and CDC-sponsored (n = 123) systems; these systems held >75% of all cases in common, and each system achieved >85% sensitivity . Conventional reporting contained 88% and 76% of the DRSP cases identified by the county- and CDC-sponsored systems, respectively, but did not capture infections produced by susceptible isolates . Both the county- and CDC-sponsored systems indicated that large proportions of isolates were resistant to penicillin and extended-spectrum cephalosporins . The county-sponsored DRSP surveillance system was inexpensive, simple to execute, and relevant to local needs.

J Obstet Gynecol Neonatal Nurs, 2001 Nov-Dec, 30(6), 659 - 66
Maternal screening and treatment for group B streptococcus; James DC; Maternal group B streptococcus colonization can result in complications for both mother and fetus . There are two protocols for decreasing the risk of infection: antenatal cultures and intrapartum risk-factor screening . Compliance with guidelines improves with the active participation of nurses who monitor women at risk, notify clinicians when treatment is appropriate, and provide patient support and education.

J Obstet Gynecol Neonatal Nurs, 2001 Nov-Dec, 30(6), 649 - 58
Group B streptococcal infections in newborns; Mullaney DM; Group B streptococcus (GBS) is the most common cause of neonatal infection in North America and is associated with morbidity and mortality . Prompt recognition and treatment of the infection is imperative . Diagnostic tests and treatment options vary, without clear research-based recommendations . Future trends should focus on GBS infection as a public health issue, with an emphasis on prevention.

J Vet Diagn Invest, 2001 Nov, 13(6), 502 - 8
Endometritis in postparturient cattle associated with bovine herpesvirus-4 infection: 15 cases; Frazier K et al.; Suppurative, ulcerative endometritis associated with bovine herpesvirus-4 (BHV-4) infection was identified in 15 postparturient dairy cows from 5 separate dairies . Characteristic eosinophilic to amphophilic intranuclear viral inclusion bodies were identified within degenerate endometrial lining epithelium and endothelial cells . Bovine herpesvirus-4 was confirmed as the etiology by a combination of fluorescent antibody assays, viral isolation, heminested PCR, ultrastructural examination of the uterus and inoculated tissue culture cells, and negative-stain electron microscopy of tissue culture supernatant . Viral particles measuring 70-95 nm were demonstrated in uterine epithelial and endothelial cells by electron microscopy . Bacteria including Arcanobacterium pyogenes, Escherichia coli, and an alpha-Streptococcus isolate were isolated from all uteri . Bovine herpesvirus-4-associated endometritis has been previously reported in sporadic cases in Europe but has not been previously reported in the United States . Endometritis associated with BHV-4 appears to be an emerging syndrome in Georgia dairy herds.

J Appl Microbiol, 2001 Nov, 91(5), 786 - 94
Ultraviolet disinfection with a novel microwave-powered device; Devine DA et al.; AIMS: To evaluate the antimicrobial efficacy of a novel u.v . beaker, powered in a domestic microwave oven . METHODS AND RESULTS: Three beakers were compared, with most rapid killing obtained in the Neutra Plasma 50 . Ultraviolet light generated within the beakers efficiently killed planktonic and surface-associated Streptococcus mutans, Pseudomonas aeruginosa, vegetative Bacillus stearothermophilus, herpes simplex and polio viruses . Candida albicans and Mycobacterium phleii were less rapidly killed, and only 70% inactivation of B . stearothermophilus endospores was achieved . Irradiation for 45 s reduced viable bacterial counts in saliva by > 99% . CONCLUSIONS: The u.v.-generating beakers efficiently reduced viable counts of bacteria, yeast and viruses . Kinetics of killing varied, reflecting the fact that lethal mechanisms are complex, and probably depend on interplay between u.v . and heat . SIGNIFICANCE AND IMPACT OF THE STUDY: This novel method of generating u.v., using a cheap and widely available power source, provides a rapid, inexpensive and non-toxic method of disinfection with a wide range of applications in hospitals, clinics and the home.

Eur J Biochem, 2001 Nov, 268(22), 5764 - 70
Engineered nonphosphorylating glyceraldehyde 3-phosphate dehydrogenase at position 268 binds hydroxylamine and hydrazine as acyl acceptors; Marchal S et al.; Nonphosphorylating nicotinamide adenine dinucleotide (phosphate)-dependent aldehyde dehydrogenases (ALDHs) catalyze the oxidation of aldehydes into either nonactivated acids or CoA-activated acids . The NADP-dependent nonphosphorylating glyceraldehyde 3-phosphate dehydrogenase (GAPN) belongs to the first subclass . It catalyzes the irreversible oxidation of glyceraldehyde 3-phosphate into 3-phosphoglycerate via a two step mechanism in which deacylation is rate-limiting . Recent studies on GAPN from Streptococcus mutans have shown that residue Glu268 plays an essential role only in the deacylation step {Marchal, S., Rahuel-Clermont, S . & Branlant, G . (2000) Biochemistry 39, 3327-3335} . The substitution of Glu268 by alanine or glutamine leads to mutants in which the attacking water molecule involved in the hydrolytic process is poorly activated . Activity can be restored by the presence of hydroxylamine and hydrazine . Neutral and protonated forms of both nucleophiles are recognized by the deacylating subsite of both mutants . pH rate profiles of deacylation show pK(a) values of 6.3 and 8.1 with hydroxylamine and hydrazine, respectively, which are those of the nucleophiles in solution . The increase in enzymatic rate is probably due to a high local concentration and not to a change of the chemical reactivity of both nucleophiles upon their binding within the active site of both mutants . The deacylation subsite of the wild-type also binds hydroxylamine and hydrazine but as inhibitors of the hydrolytic process and not as acyl acceptors . Altogether, the results point out the crucial role of the carboxyl group of Glu268 in preventing nucleophiles, other than water, from binding as efficient acyl acceptors . This may also explain why CoA-dependent ALDHs never possesses a glutamate residue at position 268.

FEMS Immunol Med Microbiol, 2001 Oct, 31(3), 175 - 80
Epitope analyses of pneumococcal surface protein A: a combination of two monoclonal antibodies detects 94% of clinical isolates; Kolberg J et al.; Immunisation of BALB/c mice with seven heat-treated Norwegian clinical isolates of Streptococcus pneumoniae of different serotypes elicited mainly monoclonal antibodies (mAbs) to pneumococcal surface protein A (PspA) . It was remarkable that the fusions resulted only in a few mAbs directed against other protein antigens . Dot blot analysis with 16 mAbs using clinical isolates representing 23 different capsular types and the uncapsulated reference strain R36A showed that some of the mAbs bound to PspA epitopes expressed by a low number of strains whereas others bound to broadly distributed epitopes . On the basis of their reactivities, seven of these mAbs could be divided into two groups recognising different subsets of pneumococci . The three mAbs in the narrow reacting group bound to epitopes found in 21-25% of the strains whereas the four mAbs in the broad reacting group detected more than 57% of the analysed strains . The epitopes for these seven antibodies were surface exposed on live exponential phase grown pneumococci as shown by flow cytometry . The finding that a combination of mAb 180,C-1 (IgG2a) from the first group and mAb 170,E-11 (IgG2a) from the second group detected 94% of the examined strains is interesting because PspA has been reported by others to be a serological highly variable protein.

Nature, 2001 Nov 22, 414(6862), 454 - 7
Innate antimicrobial peptide protects the skin from invasive bacterial infection; Nizet V et al.; In mammals, several gene families encode peptides with antibacterial activity, such as the beta-defensins and cathelicidins . These peptides are expressed on epithelial surfaces and in neutrophils, and have been proposed to provide a first line of defence against infection by acting as 'natural antibiotics' . The protective effect of antimicrobial peptides is brought into question by observations that several of these peptides are easily inactivated and have diverse cellular effects that are distinct from antimicrobial activity demonstrated in vitro . To investigate the function of a specific antimicrobial peptide in a mouse model of cutaneous infection, we applied a combined mammalian and bacterial genetic approach to the cathelicidin antimicrobial gene family . The mature human (LL-37) and mouse (CRAMP) peptides are encoded by similar genes (CAMP and Cnlp, respectively), and have similar alpha-helical structures, spectra of antimicrobial activity and tissue distribution . Here we show that cathelicidins are an important native component of innate host defence in mice and provide protection against necrotic skin infection caused by Group A Streptococcus (GAS).

Acta Otolaryngol, 2001 Oct, 121(7), 808 - 12
Effects of antibiotics and steroid on middle ear mucosa in rats with experimental acute otitis media; Park SN et al.; The prevention of mucosal changes induced by experimental pneumococcal otitis media by means of antibiotics has been demonstrated previously . However, the effect of combined antibiotic and steroid therapy on the middle ear mucosa in acute otitis media (AOM) has not been determined . The right middle ears of 27 rats were inoculated with a log-phase type 3 Streptococcus pneumoniae, with the left ears serving as controls . Penicillin G was administered to nine rats and penicillin G and dexamethasone in combination were administered to nine rats after bacterial challenge; the remaining nine rats were not treated . Three animals from each group were sacrificed on Days 4, 7 and 14 after challenge . Tympanic membranes and middle ear mucosa were examined using otomicroscopy and light microscopy . Structural changes were diminished in both the antibiotic-treated and antibiotic + steroid-treated groups, compared with those in the untreated infected controls . The antibiotic + steroid-treated group showed the most marked decrease in structural change, especially in the mucosal metaplasia to the secretory epithelium . The results suggest that combination therapy with antibiotics and steroid in AOM is the most effective at reducing the treatment period and preventing persistent mucosal changes, which may decrease the risk of development of secretory otitis media as a sequela of AOM.

Zhonghua Kou Qiang Yi Xue Za Zhi, 2001 Jul, 36(4), 301 - 3
{Effect of a new triclosan-containing mouth rinse on oral infection}; Wu X et al.; OBJECTIVE: To study the effect of a new Triclosan-containing mouthrinse--LIBO Anti-plaque mouth rinse on oral infection . METHODS: 1 . Before and after the use of triclosan mouthrinse: the gingival data were checked and secorded; plaque sausples were collected, cultured in selective and non-selective media, bacteria were isolated, sounted, and compased . 2 . With Streptococcus mutans and P . Gingivalis as experimental bacteria, triclosan and chlorhexidine (CHX) mouthrinses anti-bacterium substance, the minimum inhibitory concentrations (MICs) of the two rinses were compared . 3 . Smooth plates with the film of Streptococcus mutans C were set in different mouthrinses and water . Observing the exfoliation of bacteria film from the plates in three agents . RESULTS: 1 . Triclosan mouthrinse was effective to decrease the plaque index (PLI) and supragingival bleeding index (SBI) . 2 . The bacteria count obtained after use of triclosan mouthrinse was lower than that before using it . 3 . The minimum inhibitory concentrations of triclosan mouthrinse against Streptococcus mutans C was much lower than that of chlorhexidine mouthrinse . 4 . In triclosan mouthrinse, the bacterial films were most easily exfoliated from the plate . Triclosan mouthrinse has strongest anti-adhesion effect among the three tested agents . CONCLUSIONS: Triclosan mouthrinse has continuous disinfecting effect and help control the formation and adhesion of dental plaque.

Zhonghua Kou Qiang Yi Xue Za Zhi, 2001 Jul, 36(4), 281 - 4
{Typing of Streptococcus mutans (serotype C) by arbitrarily primed polymerase chain reaction}; Huang X et al.; OBJECTIVE: To study the relationship between genetic diversity within Streptococcus mutans (C), and dental caries . METHODS: One reference strain (GS5) was used to establish the suitability of primers and the initial AP-PCR conditions . Isolates of Streptococcus mutans (C) were obtained from 19 caries-free and 40 caries-active patients, and were originally isolated on mitis-salivarius-bacitracin agar . Totally 278 isolates were biochemically and serologically confirmed as Streptococcus mutans (C) . Chromosomal DNA was extracted from those isolates by Chelex . One random primer, OPA-05 was used as a template in PCR reaction . All amplification reactions were conducted in a volume of 20 microliters containing 2 microliters of 10 x reaction buffer, 200 mumol/L each of dATP, dCTP, dGTP and dTTP and 2.5 units of Taq DNA polymerase . We varied the concentrations of MgCl2 (1.5-4.5 mmol/L), template DNA (2-40 ng), and primer (0.3-0.5 mumol/L) to determine the optical conditions for AP-PCR . The temperature profile in a thermocycler was 35 cycles as follows: 94 degrees C for 1 min, at 36 degrees C for 2 min, at 72 degrees C for 2 min . The initial denaturation was at 94 degrees C for 5 min and the final extension at 72 degrees C for 5 min . RESULTS: The MgCl2 concentration in 4 mmol/L and the primer concentration in 0.5 mumol/L produced clearly distinct and reproducible fingerprints . We found 105 different patterns among the 278 isolates . In high-caries persons more than one genotype isolates of Streptococcus mutans (C) were colonized . CONCLUSIONS: Isolates of Streptococcus mutans (C) exist apparent genetic diversity . The genotypes of isolates might relate to differences in caries susceptibility.

Am J Obstet Gynecol, 2001 Nov, 185(5), 1174 - 9
Biodegradable microspheres containing group B Streptococcus vaccine: immune response in mice; Hunter SK et al.; OBJECTIVE: This study seeks to show the feasibility of producing a group B Streptococcus (GBS) vaccine, which is capable of producing both a local IgA immune response at the mucosal surface where GBS is colonized and a humoral IgG response, which is capable of transplacental passive immunization . STUDY DESIGN: Inactivated GBS antigen was microencapsulated in poly (D, L-lactic-co-glycolic acid) (PLG) with a water-in-oil-in-water double emulsion technique . Immunostimulatory synthetic oligodeoxynucleotides containing cytidine-phosphate-guanosine (CpG) motifs were coencapsulated as a potent adjuvant . The ICR strain of mouse was used in these studies . Female mice with normal immune systems were immunized with the PLG microparticles containing GBS type III polysaccharide (GBS PS) vaccine and CpG adjuvant (PLG/GBS/CpG) via the oral, vaginal, or nasal routes or by the intramuscular or intraperitoneal routes . Booster doses were administered 4 weeks after the initial immunization . Vaginal washings and blood samples were obtained 3 weeks after the booster dose and examined for both IgG and secretory IgA (sIgA) GBS antibodies with the use of an enzyme-linked immunoabsorbent assay method . RESULTS: PLG/GBS/CpG microparticles elicited a significantly higher GBS antibody response when compared with nonencapsulated GBS antigen or PLG-encapsulated GBS PS vaccine without the addition of the CpG adjuvant . IgG and secretory IgA (sIgA) antibodies to GBS antigen were documented in both the vaginal washings and blood samples . CONCLUSION: Preliminary findings indicate that this novel PLG/GBS/CpG vaccine elicited both IgA and IgG antibody responses to the GBS PS antigen studied . This antibody response may provide both protection against maternal GBS colonization and passive transplacental immunization for the fetus and neonate.

J Bacteriol, 2001 Dec, 183(24), 7354 - 64
relA-Independent amino acid starvation response network of Streptococcus pyogenes; Steiner K et al.; Streptococcus pyogenes (group A streptococcus {GAS}), a multiple-amino-acid-auxotrophic human pathogen, may face starvation for essential amino acids during various stages of the infection process . Since the response of GAS to such conditions is likely to influence pathogenetic processes, we set out to identify by transcriptional analyses genes and operons that are responsive to amino acid starvation and examined whether functionally meaningful response patterns can be ascertained . We discovered that GAS are capable of mounting a relA-independent amino acid starvation response that involves transcriptional modulation of a wide array of housekeeping genes as well as accessory and dedicated virulence genes . Housekeeping genes that were upregulated during starvation of both wild-type and relA mutant strains included the newly identified T-box members of the aminoacyl-tRNA synthetase genes, the genes for components of the tmRNA-mediated peptide tagging and proteolysis system for abnormal proteins (ssrA, smpB, clpP, and clpC), and the operons for the dnaK and groE groups of molecular chaperones . In addition to upregulation of the genes for oligopeptide permease (opp), intracellular peptidase (pepB), and the two-component regulator covRS reported previously (K . Steiner and H . Malke, Mol . Microbiol . 38:1004-1016, 2000), amino acid starvation stimulated the transcription of the growth phase-associated, virulence-regulatory fas operon, the streptolysin S operon (sag), and the gene for autoinducer-2 production protein (luxS) . A prominent feature of operons exhibiting internal transcriptional termination (opp, fas, and sag) was starvation-promoted full-length transcription, a mechanism that improves the efficacy of these systems by increasing the level of coordinate transcription of functionally related genes . Based on these results, a regulatory network with feedback mechanisms is proposed that counteracts the stringent response, links the levels of key rate-limiting enzymes to virulence gene expression, and enables the organism in a dynamic way to take advantage of protein-rich environments provided by its human host . As several of the affected target genes are controlled by more than one regulator, fine modulation may result in accordance with the demands imposed by ecologically different colonization sites upon the adaptive capacity of the pathogen.

J Bacteriol, 2001 Dec, 183(24), 7295 - 307
Regulation of Streptococcus pneumoniae clp genes and their role in competence development and stress survival; Chastanet A et al.; In vitro mariner transposon mutagenesis of Streptococcus pneumoniae chromosomal DNA was used to isolate regulatory mutants affecting expression of the comCDE operon, encoding the peptide quorum-sensing two-component signal transduction system controlling competence development . A transposon insertion leading to increased comC expression was found to lie directly upstream from the S . pneumoniae clpP gene, encoding the proteolytic subunit of the Clp ATP-dependent protease, whose expression in Bacillus subtilis is controlled by the CtsR repressor . In order to examine clp gene regulation in S . pneumoniae, a detailed analysis of the complete genome sequence was performed, indicating that there are five likely CtsR-binding sites located upstream from the clpE, clpP, and clpL genes and the ctsR-clpC and groESL operons . The S . pneumoniae ctsR gene was cloned under the control of an inducible promoter and used to demonstrate regulation of the S . pneumoniae clpP and clpE genes and the clpC and groESL operons by using B . subtilis as a heterologous host . The CtsR protein of S . pneumoniae was purified and shown to bind specifically to the clpP, clpC, clpE, and groESL regulatory regions . S . pneumoniae Delta ctsR, Delta clpP, Delta clpC, and Delta clpE mutants were constructed by gene deletion/replacement . ClpP was shown to act as a negative regulator, preventing competence gene expression under inappropriate conditions . Phenotypic analyses also indicated that ClpP and ClpE are both required for thermotolerance . Contrary to a previous report, we found that ClpC does not play a major role in competence development, autolysis, pneumolysin production, or growth at high temperature of S . pneumoniae.

Clin Orthop, 2001 Nov, (392), 15 - 23
Infection in total knee replacement: a retrospective review of 6489 total knee replacements; Peersman G et al.; Six thousand four hundred eighty-nine knee replacements were done in 6120 patients at the authors' institution between 1993 and 1999 . Operations were done in a theater with vertical laminar flow and with the surgical team using body exhaust suits . Of these knee replacements, 116 knees became infected and 113 were available for followup . One hundred of the infections occurred in patients undergoing primary knee replacement, whereas the remaining infections occurred in patients undergoing revision knee replacement . Ninety-seven of these knees (86%) had deep periprosthetic infections and the remaining 16 knees had superficial wound infections . One third of the deep infections occurred within the first 3 months after surgery and the remaining 2/3 occurred after 3 months . The overall early deep infection rate for patients undergoing a primary knee replacement was 0.39%, whereas the rate for patients undergoing a revision knee replacement was 0.97% . A cohort of noninfected knee replacements from patients matched for gender, age, and month of surgery was used as a control group . Those comorbidities that were statistically significant in increasing the risk of infection were prior open surgical procedures, immunosuppressive therapy, poor nutrition, hypokalemia, diabetes mellitus, obesity, and a history of smoking . Patients undergoing revision procedures had a statistically higher risk of infection than did patients undergoing primary surgeries . If the surgery took longer than 2.5 hours, the risk of infection was increased significantly . There was no change in the infection rate when the perioperative antibiotic prophylaxis was decreased from 48 to 24 hours after surgery . The predominant infectious organisms were gram-positive (Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus Group B) . Twenty percent of the knees that were infected clinically had no organisms that could be identified . In each case, the patient had been treated empirically at another institution with antibiotics before a culture of the joint was obtained.

Ann Plast Surg, 2001 Nov, 47(5), 565 - 7
Invasive streptococcal infection of the periorbita and forehead; Gates RL et al.; Recent epidemiological reports suggest an increased frequency of invasive streptococcal infections linked to the appearance of a dominant group A Streptococcus serotype . Necrotizing streptococcal infections involving the skin and soft tissues of the face are uncommon . This case demonstrates the aggressive and invasive nature of these infections . The patient presented with symptoms of angioedema and was treated with corticosteroids . Her condition worsened and plastic surgery was consulted . There was extensive necrosis of the periorbital and forehead soft tissue, requiring extensive debridement to control the invasive process . Multiple reconstructive procedures were performed to close the defects and to preserve function of the facial muscles and eyelids . The literature indicates less than 50 reported cases of necrotizing streptococcal infections limited to the periorbita . This case reflects the importance of rapid diagnosis, and emphasizes the need for prompt and appropriate surgical treatment.

Jpn Circ J, 2001 Nov, 65(11), 997 - 1000
Recurrent aortic valve endocarditis caused by Gemella morbillorum--report of a case and review of the literature; Akiyama K et al.; Gemella morbillorum (G . morbillorum) is part of the commensal flora of the oropharynx and intestinal tract, and on rare occasions causes infective endocarditis . A 55-year-old man with massive aortic regurgitation caused by recurrent infective endocarditis with G . morbillorum had a history of prior endocarditis caused by alpha-hemolytic streptococcus and multiple antibiotic allergies 5 years prior, and was successfully treated by aortic valve replacement . Almost all the reported cases of endocarditis caused by G . morbillorum have been bacteriologically cured with antibiotics and this is the first reported case of recurrent endocarditis caused by G . morbillorum in which the initial infection was bacteriologically cured by antibiotics and the secondary infection treated with valve replacement . This organism can be one of the causes of infective endocarditis and prompt surgical repair is mandatory if the infection is refractory or there is progression of congestive heart failure under antibiotic cover.

J Vet Med Sci, 2001 Oct, 63(10), 1083 - 9
Therapeutic effect of hyaluronic acid on experimental osteoarthrosis of ovine temporomandibular joint; Kim CH et al.; A symptomatic relief by hyaluronic acid (HA, MW: 3.5 x 10(6)), which is synthesized by Streptococcus spp, was investigated in experimental ovine osteoarthrosis . Bilateral osteoarthrosis (OA) of the temporo-mandibular joints (TMJs) was induced by perforating discs and by scrapping subchondral condylar surface . HA was intra-articularly injected into the left joints of 6 sheep on 7, 10, 14, 17 and 21 days after the operation and physiological saline as the control was injected into the contralateral (right) joints on the same day . Three sheep were killed at I month post-operation (MPO) and the remaining three sheep were killed at 3 MPO . Various responses such as proliferation of fibrous tissue, denudation, erosion, osteophyte formation, subcortical cyst formation and ankylosis were observed radiographically and histopathologically . The treatment of HA ameliorated the degenerative changes and lowered the osteoarthrotic score in the left joints at I MPO (9.96 vs 5.81) and 3 MPO (10.86 vs 5.29) compared to the right joints . These results indicate that a repeated intra-articular injection of HA inhibits the progression of OA in ovine TMJs by inducing the development of articular cartilage and by reducing the proliferation of fibrotic tissue.

Kansenshogaku Zasshi, 2001 Oct, 75(10), 846 - 50
{Acute exacerbations due to Streptococcus pneumoniae in chronic lower respiratory tract infections during long-term macrolide therapy}; Maeda K et al.; In Japan, long-term 14-membered macrolide administration is chosen as a first line therapy against chronic lower respiratory tract infections (CLRTIs) such as diffuse panbronchiolitis, bronchiectasis and chronic bronchitis . However, sometimes acute exacerbations occur in these cases, even if therapy is effective . We investigated 18 episodes of CLRTIs exacerbations that were caused by Streptococcus pneumoniae during long-term macrolides therapy from 1991 to 1999 to clarify the clinical features and prevalence of antimicrobial resistance in S . pneumoniae . Exacerbations did not occur only in winter season, but also in other seasons . Among 18 episodes of exacerbation, only 7 episodes (39%) revealed infiltration in chest roentogenogram and few episodes revealed marked elevations of inflammation markers in laboratory data . Intermediate resistance or resistance rates of S . pneumoniae isolated from sputum or transtracheal aspiration were 100% to erythromycin, 67% to clindamycin or minocycline, 11% to ampicillin, and 0% to cephazoline or imipenem . Coresistance to erythromycin, clindamycin and minocycline was seen in a half of the episodes . Resistance was not correlated with the duration of macrolides administration . All episodes were mainly treated with beta-lactam agents or fluoroquinolones and cured successfully . These findings suggest that acute exacerbations in CLRTIs caused by S . pneumoniae during long-term macrolides therapy do not reveal severe clinical aspects and can be treated successfully at present, but attention should be paid to the trend of antibiotic susceptibility in S . pneumoniae.

Int J Antimicrob Agents, 2001 Nov, 18(5), 433 - 6
Molecular surveillance of macrolide, tetracycline and quinolone resistance mechanisms in 1191 clinical European Streptococcus pneumoniae isolates; Schmitz FJ et al.; Streptococcus pneumoniae isolates (n=1191) were collected during a 1997-1999 European surveillance study . In addition to susceptibility data, a molecular epidemiological survey of their mechanisms of resistance to macrolides, tetracyclines, and quinolones was provided . Of the isolates tested, 72.6% were penicillin-susceptible, 19.9% penicillin-intermediate and 7.5% penicillin-resistant . There was an obvious relationship between resistance to penicillin and resistance to erythromycin (19% of all isolates), clindamycin (14%) and tetracycline (23%) . Only one isolate was resistant to levofloxacin . Seventy-three percent of the European S . pneumoniae isolates resistant to erythromycin (n=229) carried the erm(B) gene, while the remaining 27% possessed the mef(A) gene . No mutations were detected in 23S rRNA or in ribosomal proteins L4 and L22 . All tetracycline-resistant isolates (n=277) carried the tet(M) gene; none carried the tet(O) gene . Classical mutations in gyrA (Ser 81-Phe or Tyr) and parC (Ser 79-Phe and Asp 83-Asn) and efflux contributed to the decreased quinolone susceptibility . This study of recent European S . pneumoniae isolates can be used to recognize any changes in susceptibility patterns and resistance mechanisms that may occur in the future.

Antimicrob Agents Chemother, 2001 Dec, 45(12), 3517 - 23
Genetic analyses of mutations contributing to fluoroquinolone resistance in clinical isolates of Streptococcus pneumoniae; Weigel LM et al.; Twenty-one clinical isolates of Streptococcus pneumoniae showing reduced susceptibility or resistance to fluoroquinolones were characterized by serotype, antimicrobial susceptibility, and genetic analyses of the quinolone resistance-determining regions (QRDRs) of gyrA, gyrB, parC, and parE . Five strains were resistant to three or more classes of antimicrobial agents . In susceptibility profiles for gatifloxacin, gemifloxacin, levofloxacin, moxifloxacin, ofloxacin, sparfloxacin, and trovafloxacin, 14 isolates had intermediate- or high-level resistance to all fluoroquinolones tested except gemifloxacin (no breakpoints assigned) . Fluoroquinolone resistance was not associated with serotype or with resistance to other antimicrobial agents . Mutations in the QRDRs of these isolates were more heterogeneous than those previously reported for mutants selected in vitro . Eight isolates had amino acid changes at sites other than ParC/S79 and GyrA/S81; several strains contained mutations in gyrB, parE, or both loci . Contributions to fluoroquinolone resistance by individual amino acid changes, including GyrB/E474K, ParE/E474K, and ParC/A63T, were confirmed by genetic transformation of S . pneumoniae R6 . Mutations in gyrB were important for resistance to gatifloxacin but not moxifloxacin, and mutation of gyrA was associated with resistance to moxifloxacin but not gatifloxacin, suggesting differences in the drug-target interactions of the two 8-methoxyquinolones . The positions of amino acid changes within the four genes affected resistance more than did the total number of QRDR mutations . However, the effect of a specific mutation varied significantly depending on the agent tested . These data suggest that the heterogeneity of mutations will likely increase as pneumococci are exposed to novel fluoroquinolone structures, complicating the prediction of cross-resistance within this class of antimicrobial agents.

Antimicrob Agents Chemother, 2001 Dec, 45(12), 3504 - 8
Prevalence and mechanisms of macrolide resistance in invasive and noninvasive group B streptococcus isolates from Ontario, Canada; de Azavedo JC et al.; Macrolide resistance has been demonstrated in group B streptococcus (GBS), but there is limited information regarding mechanisms of resistance and their prevalence . We determined these in GBS obtained from neonatal blood cultures and vaginal swabs from pregnant women . Of 178 isolates from cases of neonatal GBS sepsis collected from 1995 to 1998, 8 and 4.5% were resistant to erythromycin and clindamycin, respectively, and one isolate showed intermediate penicillin resistance (MIC, 0.25 microg/ml) . Of 101 consecutive vaginal or rectal/vaginal isolates collected in 1999, 18 and 8% were resistant to erythromycin and clindamycin, respectively . Tetracycline resistance was high (>80%) among both groups of isolates . Of 32 erythromycin-resistant isolates, 28 possessed the erm methylase gene (7 ermB and 21 ermTR/ermA) and 4 harbored the mefA gene; one isolate harbored both genes . One isolate which was susceptible to erythromycin but resistant to clindamycin (MIC, 4 microg/ml) was found to have the linB gene, previously identified only in Enterococcus faecium . The mreA gene was found in all the erythromycin-resistant strains as well as in 10 erythromycin-susceptible strains . The rate of erythromycin resistance increased from 5% in 1995-96 to 13% in 1998-99, which coincided with an increase in macrolide usage during that time.

Antimicrob Agents Chemother, 2001 Dec, 45(12), 3334 - 40
Antimicrobial susceptibilities of 1,684 Streptococcus pneumoniae and 2,039 Streptococcus pyogenes isolates and their ecological relationships: results of a 1-year (1998-1999) multicenter surveillance study in Spain; Perez-Trallero E et al.; A nationwide multicenter susceptibility surveillance study which included 1,684 Streptococcus pneumoniae and 2,039 S . pyogenes isolates was carried out over 1 year in order to assess the current resistance patterns for the two most important gram-positive microorganisms responsible for community-acquired infections in Spain . Susceptibility testing was done by a broth microdilution method according to National Committee for Clinical Laboratory Standards M100-S10 interpretative criteria . For S . pneumoniae, the prevalences of highly resistant strains were 5% for amoxicillin and amoxicillin-clavulanic acid; 7% for cefotaxime; 22% for penicillin; 31% for cefuroxime; 35% for erythromycin, clarithromycin, and azithromycin; and 42% for cefaclor . For S . pyogenes, the prevalence of erythromycin resistance was 20% . Efflux was encountered in 90% of S . pyogenes and 5% of S . pneumoniae isolates that exhibited erythromycin resistance . Erythromycin resistance was associated with clarithromycin and azithromycin in both species, regardless of phenotype . Despite the different nature of the mechanisms of resistance, a positive correlation (r = 0.612) between the two species in the prevalence of erythromycin resistance was found in site-by-site comparisons, suggesting some kind of link with antibiotic consumption . Regarding ciprofloxacin, the MIC was >or=4 microg/ml for 7% of S . pneumoniae and 3.5% of S . pyogenes isolates . Ciprofloxacin resistance (MIC, >or=4 microg/ml) was significantly (P < 0.05) associated with macrolide resistance in both S . pyogenes and S . pneumoniae and with penicillin nonsusceptibility in S . pneumoniae.

J Med Chem, 2001 Nov 22, 44(24), 4027 - 30
Synthesis and antibacterial activity of acylides (3-O-acyl-erythromycin derivatives): a novel class of macrolide antibiotics; Tanikawa T et al.; Introduction of an acyl group to the 3-O-position of erythromycin A derivatives instead of L-cladinose led to a novel class of macrolide antibiotics that we named "acylides" . The 3-O-nitrophenylacetyl derivative TEA0777 showed significantly potent activity against not only erythromycin-susceptible Gram-positive pathogens but also inducibly macrolides-lincosamides-streptogramin B (MLS(B))-resistant Staphylococcus aureus and efflux-resistant Streptococcus pneumoniae . These results indicated that acylides have potential as next-generation macrolide antibiotics.

Anim Health Res Rev, 2000 Dec, 1(2), 95 - 102
The role of pulmonary intravascular macrophages in porcine reproductive and respiratory syndrome virus infection; Thanawongnuwech R et al.; The objective of this article is to summarize the current state of knowledge of the complex interaction of porcine reproductive and respiratory syndrome virus (PRRSV) and porcine pulmonary intravascular macrophages (PIMs) . PIMs play an important role in pulmonary surveillance, and in the past few years we have investigated their role in PRRSV infection . PRRSV antigens and nucleic acids have been demonstrated in PIMs both in vitro and in vivo . Examination of cultured PIMs infected with PRRSV revealed the accumulation of viral particles in the smooth-walled vesicles . PRRSV-infected PIMs in vitro yielded a virus titer similar to pulmonary alveolar macrophages . PRRSV infection induces either apoptosis or cell lysis of PIMs . The in vitro bactericidal activity of PRRSV-infected PIMs is significantly decreased . Phagocytic activity of PIMs, as measured by pulmonary copper clearance, is significantly decreased in PRRSV-infected pigs . This evidence supports the hypothesis that PRRSV-induced damage to PIMs results in increased susceptibility to bacteremic diseases . Recent studies with PRRSV and Streptococcus suis coinfection confirmed that PRRSV predisposes pigs to S . suis infection and bacteremia . These results could explain the increase in bacterial respiratory diseases and septicemias observed in PRRSV-infected pigs.

Ann Neurol, 2001 Nov, 50(5), 588 - 95
Poststreptococcal acute disseminated encephalomyelitis with basal ganglia involvement and auto-reactive antibasal ganglia antibodies; Dale RC et al.; Antibasal ganglia antibodies (ABGA) are associated with Sydenham's chorea and pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections . We present 10 patients with acute disseminated encephalomyelitis (ADEM) associated with Group A beta hemolytic streptococcal infection . The clinical phenotype was novel, with 50% having a dystonic extrapyramidal movement disorder, and 70% a behavioral syndrome . None of the patients had rheumatic fever or Sydenham's chorea . Enzyme-linked immunosorbent assay, Western immunoblotting, and immunohistochemistry were used to detect ABGA . Neurological (n = 40) and streptococcal (n = 40) controls were used for comparison . Enzyme-linked immunosorbent assay results showed significantly elevated ABGA in the patients with poststreptococcal ADEM . Western immunoblotting demonstrated ABGA reactivity to three dominant protein bands of 60, 67, or 80 kDa; a finding not reproduced in controls . Fluorescent immunohistochemistry demonstrated specific binding to large striatal neurones, which was not seen in controls . Streptococcal serology was also significantly elevated in the poststreptococcal ADEM group compared with neurological controls . Magnetic resonance imaging studies showed hyperintense basal ganglia in 80% of patients with poststreptococcal ADEM, compared to 18% of patients with nonstreptococcal ADEM . These findings support a new subgroup of postinfectious autoimmune inflammatory disorders associated with Group A beta hemolytic streptococcus, abnormal basal ganglia imaging, and elevated ABGA.

J Dent Res, 2001 Oct, 80(10), 1945 - 8
Association of Streptococcus mutans infection and oral developmental nodules in pre-dentate infants; Wan AK et al.; Since dental caries may present soon after tooth eruption, we hypothesized that colonization of Streptococcus mutans can occur in the predentate stages . In this study, we examined S . mutans colonization and its association with oral developmental nodules (Bohn's nodules) in 60 pre-term and 128 full-term, three-month-old infants . Overall, S . mutans was cultured from 30% (56/188) of the infants, and oral developmental nodules were noted in 55% (103/188) . Compared with the pre-term, full-term infants showed a higher prevalence of S . mutans (34% vs . 20%, p < 0.02) as well as developmental nodules (61% vs . 42%, p < 0.05) . In both groups, S . mutans was positively associated with numbers of developmental nodules in a dose-response relationship (p < 0.001), and with maternal salivary levels of the bacteria (p = 0.03) . The permanence of S . mutans infection was confirmed by repeat saliva sampling at 6 months of age . Our results thus showed that many infants have already acquired S . mutans at 3 months of age, prior to tooth eruption.

Eur J Cancer B Oral Oncol, 1993 Oct, 29B(4), 307 - 12
In vivo effects of fluoride, chlorhexidine and zinc ions on acid formation by dental plaque and salivary mutans streptococcus counts in patients with irradiation-induced xerostomia; Giertsen E et al.; Irradiation therapy including major salivary glands may result in xerostomia and enhanced susceptibility to dental caries . The present aim was to assess the ability of mouthrinses with F-, Zn2+, and chlorhexidine (CH), in various combinations, to reduce acidogenic potential of dental plaque and salivary mutans streptococcus counts (SMSC) in 7 patients with xerostomia secondary to irradiation . The patients rinsed twice daily for 3 weeks with the following test solutions: (1) 12 mmol/l NaF (F; control), (2) NaF + 20 mmol/l ZnCl2 (F-Zn), and (3) NaF + 1.1 mmol/l CH (F-CH) . Resting periods (F) of varying lengths were incorporated . Acid formation by dental plaque was monitored as plaque pH response to a sucrose mouthrinse, at the end of each test period, 4 h after mouthrinsing with test solution . Plaque pH was measured repeatedly at 2-8 sites in each patient before, and up to 60 min after the sucrose mouthrinse using touch microelectrodes . SMSC were determined using Dentocult SM-Strip mutans . Compared with F, F-CH significantly (P < or = 0.02) reduced acid formation by plaque and SMSC, whereas F-Zn did not affect acid formation or SMSC significantly . Pilot experiments in 4 patients showed mouthrinses with NaF + 0.55 mmol/l CH + 10 mmol/l Zn2+ to be ineffective, whereas NaF + 2.2 mmol/l CH was highly effective, but no better than F-CH . Twice daily mouthrinses with 12 mmol/l NaF in combination with 1.1 mmol/l CH may be an effective regimen to prevent post-irradiation caries.

J Biol Chem, 2002 Feb 8, 277(6), 4343 - 50 Epub 2001 Nov 12.
Structure and mechanism of CTP:phosphocholine cytidylyltransferase (LicC) from Streptococcus pneumoniae; Kwak BY et al.; Pneumococcal LicC is a member of the nucleoside triphosphate transferase superfamily and catalyzes the transfer of a cytidine monophosphate from CTP to phosphocholine to form CDP-choline . The structures of apo-LicC and the LicC-CDP-choline-Mg(2+) ternary complex were determined, and the comparison of these structures reveals a significant conformational change driven by the multivalent coordination of Mg(2+) . The key event is breaking the Glu(216)-Arg(129) salt bridge, which triggers the coalescence of four individual beta-strands into two extended beta-sheets . These movements reorient the side chains of Trp(136) and Tyr(190) for the optimal binding and alignment of the phosphocholine moiety . Consistent with these conformational changes, LicC operates via a compulsory ordered kinetic mechanism . The structures explain the substrate specificity of LicC for CTP and phosphocholine and implicate a direct role for Mg(2+) in aligning phosphocholine for in-line nucleophilic attack and stabilizing the negative charge that develops in the pentacoordinate transition state . These results provide a structural basis for assigning a specific role for magnesium in the catalytic mechanism of pneumococcal LicC.

Infect Immun, 2001 Dec, 69(12), 7583 - 7
Pneumococcal conjugate vaccines overcome splenic dependency of antibody response to pneumococcal polysaccharides; Breukels MA et al.; Protection against infections with Streptococcus pneumoniae depends on the presence of antibodies against capsular polysaccharides that facilitate phagocytosis . Asplenic patients are at increased risk for pneumococcal infections, since both phagocytosis and the initiation of the antibody response to polysaccharides take place in the spleen . Therefore, vaccination with pneumococcal polysaccharide vaccines is recommended prior to splenectomy, which, as in the case of trauma, is not always feasible . We show that in rats, vaccination with a pneumococcal conjugate vaccine can induce good antibody responses even after splenectomy, particularly after a second dose . The spleen remains necessary for a fast, primary response to (blood-borne) polysaccharides, even when they are presented in a conjugated form . Coadministration of a conjugate vaccine with additional nonconjugated polysaccharides of other serotypes did not improve the response to the nonconjugated polysaccharides . We conclude that pneumococcal conjugate vaccines can be of value in protecting asplenic or hyposplenic patients against pneumococcal infections.

Infect Immun, 2001 Dec, 69(12), 7572 - 82
Distribution and genetic diversity of suilysin in Streptococcus suis isolated from different diseases of pigs and characterization of the genetic basis of suilysin absence; King SJ et al.; Streptococcus suis is an economically important pathogen of pigs responsible for a variety of diseases including meningitis, septicemia, arthritis, and pneumonia, although little is known about the mechanisms of pathogenesis or virulence factors associated with this organism . Here, we report on the distribution and genetic diversity of the putative virulence factor suilysin, a member of the thiol-activated toxin family of gram-positive bacteria . On the basis of PCR analysis of over 300 isolates of S . suis, the suilysin-encoding gene, sly, was detected in 69.4% of isolates . However, sly was present in a considerably higher proportion of isolates obtained from cases of meningitis, septicemia, and arthritis (>80%) and isolates obtained from asymptomatic tonsillar carriage (>90%) than lung isolates associated with pneumonia (44%) . With the exception of serotypes 1, 14, and 1/14, there was no strong correlation between the presence of suilysin and serotype . Analysis of the genetic diversity of suilysin by restriction fragment length polymorphism and sequence analysis found that the suilysin gene, where present, is highly conserved with a maximum of 1.79% diversity at the nucleotide level seen between sly alleles . Assays of hemolytic activity and hybridization analysis provided no evidence for a second member of the thiol-activated toxin family in S . suis . Inverse PCR was used to characterize regions flanking sly, which in turn allowed the first characterization of the equivalent region in a strain lacking sly . Sequence comparison of these regions from sly-positive (P1/7) and sly-negative (DH5) strains indicated that two alternative arrangements are both flanked by genes with highest similarity to haloacid dehalogenase-like hydrolases (5' end) and putative N-acetylmannosamine-6-phosphate epimerases (3' end) . However, sly appears to be completely absent from the alternative arrangement, and a gene of unknown function is located in the equivalent position . Finally, PCR analysis of multiple sly-positive and -negative strains indicated that these two alternative genetic arrangements are conserved among many S . suis isolates.

Infect Immun, 2001 Dec, 69(12), 7565 - 71
Streptococcus pneumoniae PstS production is phosphate responsive and enhanced during growth in the murine peritoneal cavity; Orihuela CJ et al.; Differential display-PCR (DDPCR) was used to identify a Streptococcus pneumoniae gene with enhanced transcription during growth in the murine peritoneal cavity . Northern dot blot analysis and comparative densitometry confirmed a 1.8-fold increase in expression of the encoded sequence following murine peritoneal culture (MPC) versus laboratory culture or control culture (CC) . Sequencing and basic local alignment search tool analysis identified the DDPCR fragment as pstS, the phosphate-binding protein of a high-affinity phosphate uptake system . PCR amplification of the complete pstS gene followed by restriction analysis and sequencing suggests a high level of conservation between strains and serotypes . Quantitative immunodot blotting using antiserum to recombinant PstS (rPstS) demonstrated an approximately twofold increase in PstS production during MPC from that during CCs, a finding consistent with the low levels of phosphate observed in the peritoneum . Moreover, immunodot blot and Northern analysis demonstrated phosphate-dependent production of PstS in six of seven strains examined . These results identify pstS expression as responsive to the MPC environment and extracellular phosphate concentrations . Presently, it remains unclear if phosphate concentrations in vivo contribute to the regulation of pstS . Finally, polyclonal antiserum to rPstS did not inhibit growth of the pneumococcus in vitro, suggesting that antibodies do not block phosphate uptake; moreover, vaccination of mice with rPstS did not protect against intraperitoneal challenge as assessed by the 50% lethal dose.

Infect Immun, 2001 Dec, 69(12), 7318 - 25
Streptococcus pneumoniae causes experimental meningitis following intranasal and otitis media infections via a nonhematogenous route; Marra A et al.; Using two different animal models of Streptococcus pneumoniae infection, we have demonstrated that this organism is able to spread to the central nervous system and cause meningitis by bypassing the bloodstream . Following respiratory tract infection induced via intranasal inoculation, bacteria were rapidly found in the bloodstream and brains in the majority of infected mice . A similar pattern of dissemination occurred following otitis media infection via transbullar injection of gerbils . However, a small percentage of animals infected by either route showed no bacteria in the blood and yet did have significant numbers of bacteria in brain tissue . Subsequent experiments using a galU mutant of S . pneumoniae, which is impaired in its ability to disseminate to the bloodstream following infection, showed that this organism is able to spread to the brain and cerebrospinal fluid . These results demonstrate that, unlike many bacterial pathogens that cause meningitis, S . pneumoniae is able to do so independent of bloodstream involvement upon different routes of infection . This may address the difficulty in treating human infections caused by this organism.

Pesqui Odontol Bras, 2001 Jan-Mar, 15(1), 70 - 6
{Effect of the application of fluoride on the superficial roughness of vitremer glass ionomer cement and microbial adhesion to this material}; Pedrini D et al.; Glass ionomer cements are important options in restorative and preventive dentistry due to their adhesion to the tooth surface and to fluoride release, which can decrease the risk of recurrent caries . The topical use of acidulated and neutral fluoride gels has been frequent in dentistry . However, this procedure can adversely affect the surface of restorative materials, increasing their roughness and the retention of dental plaque . Thus, this study evaluated the period in which Vitremer glass ionomer cement maintains its antimicrobial activity over Streptococcus mutans ATCC 25175, as well as the effects of topical application of acidulated and neutral fluoride gels on these microbiological parameters and on the superficial characteristics of the restorative material . It was verified that the antimicrobial activity of Vitremer is very transient, decreasing to an undetectable level after four days, and the topical application of fluoride gel did not restore this activity . It was observed that S . mutans ATCC 25175 adheres to this restorative material, and the topical fluorides did not affect this event . The surface of Vitremer was not altered by the application of fluoride gels.

J Biol Chem, 2002 Jan 25, 277(4), 2756 - 62 Epub 2001 Nov 09.
Structural and functional role of threonine 112 in a superantigen Staphylococcus aureus enterotoxin B; Baker MD et al.; Bacterial superantigens are potent T-cell stimulatory protein molecules produced by Staphylococcus aureus and Streptococcus pyogenes . Their superantigenic activity can be attributed to their ability to cross-link major histocompatibility complex class II molecules with T-cell receptors (TCRs) to form a tri-molecular complex . Each superantigen is known to interact with a specific V(beta) element of TCR . Staphylococcal enterotoxin B (SEB, a superantigen), a primary cause of food poisoning, is also responsible for a significant percentage of non-menstrual associated toxic shock syndrome in patients with a variety of staphylococcal infections . Structural studies have elucidated a binding cavity on the toxin molecule essential for TCR binding . To understand the crucial residues involved in binding, mutagenesis analysis was performed . Our analysis suggest that mutation of a conserved residue Thr(112) to Ser (T112S) in the binding cavity induces a selective reduction in the affinity for binding one TCR V(beta) family and can be attributed to the structural differences in the native and mutant toxins . We present a detailed comparison of the mutant structure determined at 2.0 A with the previously reported native SEB and SEB-TCR V(beta) complex structures.

Obstet Gynecol, 2001 Nov, 98(5 Pt 2), 918 - 9
Preventing recurrent second trimester group B streptococcus chorioamnionitis by intermittent prophylactic ampicillin; Marinoff DN et al.; BACKGROUND: Whereas carrying group B streptococcus during pregnancy is common, second trimester group B streptococcus chorioamnionitis with intact membranes is rare, and recurrence of the latter problem even more so . CASE: A 38-year-old multipara with a history of recurrent second trimester group B streptococcus chorioamnionitis resulting in pregnancy loss was treated, beginning at 14 weeks' gestation, with monthly prophylactic ampicillin therapy throughout pregnancy and delivered a healthy male infant at term . CONCLUSION: In women with recurrent pregnancy loss due to second trimester group B streptococcus chorioamnionitis, an intermittent prophylactic antibiotic regimen throughout pregnancy might increase the probability of successful pregnancy.

Mol Microbiol, 2001 Oct, 42(2), 539 - 51
Binding of human C4BP to the hypervariable region of M protein: a molecular mechanism of phagocytosis resistance in Streptococcus pyogenes; Berggard K et al.; The amino-terminal hypervariable region (HVR) of streptococcal M protein is required for the ability of this virulence factor to confer phagocytosis resistance . The function of the HVR has remained unknown, but the finding that many HVRs with extremely divergent sequences bind the human complement regulator C4b-binding protein (C4BP) has suggested that this ligand may play a role in phagocytosis resistance . We used the M22 system to study the function of bound C4BP and provide several lines of evidence that C4BP indeed contributes to phagocytosis resistance . First, the ability of anti-HVR antibodies to cause opsonization correlated with their ability to inhibit binding of C4BP . Secondly, a short deletion in the HVR eliminated C4BP binding and also reduced the ability of M22 to confer phagocytosis resistance . Thirdly, the addition of an excess of pure C4BP to a phagocytosis system almost completely blocked the effect of opsonizing anti-HVR antibodies . Together, our data indicate that binding of C4BP to the HVR of M22 plays an important role in phagocytosis resistance, but other properties of M22 also contribute . This study provides the first molecular insight into the mechanisms by which the HVR of an M protein confers phagocytosis resistance.

Mol Microbiol, 2001 Oct, 42(2), 495 - 502
A secondary RNA polymerase sigma factor from Streptococcus pyogenes; Opdyke JA et al.; The important human pathogen Streptococcus pyogenes (the group A streptococcus or GAS) causes diseases ranging from mild, self-limiting pharyngitis to severe invasive infections . Regulation of the expression of GAS genes in response to specific environmental differences within the host is probably key in determining the course of the infectious process, however, little is known of global regulators of gene expression in GAS . Although secondary RNA polymerase sigma factors act as global regulators of gene expression in many other bacteria, none has yet been isolated from the GAS . The newly available GAS genome sequence indicates that the only candidate secondary sigma factor is encoded by two identical open reading frames (ORFS) . These ORFS encode a protein that is 40% identical to the transcription factor ComX, believed to act as an RNA polymerase sigma factor in Streptococcus pneumoniae . To test whether the GAS ComX homologue functions as a sigma factor, we cloned and purified it from Escherichia coli . We found that in vitro, this GAS protein, which we call sigmaX, directed core RNA polymerase from Bacillus subtilis to transcribe from two GAS promoters that contain the cin-box region, required for transcription by S . pneumoniae ComX in vivo . On the other hand, GAS sigmaX did not promote transcription of a GAS promoter (hasA) expected to be dependent on sigmaA, the housekeeping or primary RNA polymerase sigma factor . Addition of monoclonal antibody that inhibited sigmaA-directed transcription had no effect on sigmaX-directed transcription, showing that the latter was not the result of contaminating sigmaA . Transcription of both cin-box-containing promoters initiated downstream of the cin-box and two different single basepair substitutions in the cin-box of the cinA promoter each caused a severe reduction of sigmaX-directed transcription in vitro . Thus, the cin-box is required for sigmaX-directed transcription.

Mayo Clin Proc, 2001 Nov, 76(11), 1167 - 70
Waterhouse-Friderichsen syndrome after infection with group A streptococcus; Karakousis PC et al.; We report a case of Waterhouse-Friderichsen syndrome associated with group A streptococcus (GAS) toxic shock syndrome in a previously healthy man . The patient presented with neck pain and fevers of 2 days' duration . Computed tomography of the neck revealed a mass in the retropharyngeal space, suggesting an abscess . Despite prompt treatment with appropriate antibiotics, the patient experienced a fulminant course and died within 8 hours of presentation . Antemortem blood cultures grew GAS positive for exotoxins A, B, and C . Postmortem examination revealed bilateral adrenal hemorrhage, consistent with Waterhouse-Friderichsen syndrome . Immunohistochemical analysis of the adrenal glands revealed the presence of GAS antigens . However, no disseminated intravascular coagulation was evident . This case demonstrates that adrenal hemorrhage can occur without associated coagulopathy and may result directly from the action of bacterial toxins.

Microbiology, 2001 Nov, 147(Pt 11), 3061 - 70
Characterization of the Streptococcus gordonii chromosomal region immediately downstream of the glucosyltransferase gene; Vickerman MM et al.; The Streptococcus gordonii glucosyltransferase gene, gtfG, is positively regulated by the upstream determinant rgg . In the present study, two ORFs, transcribed on the opposite DNA strand, were identified immediately downstream of gtfG . The first, designated dsg, shares a convergent putative transcriptional terminator with gtfG, and encodes a predicted 46 kDa transmembrane protein similar to the Yersinia enterocolitica TrsA involved in polysaccharide biosynthesis . Insertional inactivation of dsg resulted in only approximately approximately 60% of the parental level of glucosyltransferase activity . The 870 bp gene 5' to dsg is similar to the gtfG regulatory determinant . Designated rggD, this rgg-like determinant downstream of gtfG encodes a putative 33.6 kDa cytoplasmic protein . Despite their sequence similarity, the functions of rgg and rggD appear specific . Strains in which rggD was insertionally inactivated and strains containing plasmid-borne rggD had parental levels of glucosyltransferase activity . Northern blot hybridization analyses showed approximately 1.3 kb dsg-specific and approximately 1.0 kb rggD-specific mRNA transcripts associated with this region; no polycistronic transcript was observed . Although rgg-like gene products have been demonstrated to function as positive transcriptional regulators of adjacent genes in several streptococcal species, Northern blot analysis suggested that rggD did not influence the transcription of dsg or the divergent downstream ylbN-like determinant under the conditions in the present study . Comparison of this S . gordonii chromosome region to other streptococcal genomes, which do not contain the rgg/rggD-flanked region involved in glucan synthesis, raised intriguing possibilities about the origins of this chromosomal region, and also suggested that rggD might regulate a distally located gene.

Am J Dent, 2001 Aug, 14(4), 233 - 7
Antimicrobial efficacy of chloroxylenol and chlorhexidine in the treatment of infected root canals; Schafer E et al.; PURPOSE: To investigate the antimicrobial efficacy of a chlorhexidine gluconate (2.0%) and of an ethanolic chloroxylenol solution (10%) as a temporary root canal dressing against selected test microorganisms (Staphylococcus aureus, Streptococcus faecium, Escherichia coli, Candida albicans) . MATERIALS AND METHODS: Extracted single-rooted human teeth were instrumented up to size 40 . After removal of the smear layer suspensions of the test microorganisms were inserted into the root canals . After incubation for 48 hrs each suspension of the test organisms was removed and the root canals were filled with one of the two different disinfectants . The teeth were then incubated for 48 hrs . Twelve teeth and three controls were used for each of the four test organisms and each of the two regimens . After incubation, each root canal was instrumented and the removed canal wall dentin was examined microbiologically . RESULTS: With a contact time of 48 hrs between the two disinfectants and the four bacterial suspensions the medications led to a total killing of microorganisms in 82% of a total of 96 contaminated teeth . In the dentin layer situated 50 microm from the root canal, both medications achieved bacterial killing in a range from 99.9% to 99.99%, depending on the test organism . There were no significant differences (P> 0.1) between the relative antimicrobial activity of the two root canal dressings.

J Med Microbiol, 2001 Nov, 50(11), 952 - 8
Antigenic characterisation of a novel Streptococcus anginosus antigen that induces nitric oxide synthesis by murine peritoneal exudate cells; Sasaki M et al.; A novel antigen that induces nitric oxide (NO) synthesis by murine peritoneal exudate cells (PEC) was prepared from a culture supernate of Streptococcus anginosus NCTC 10713 in dialysed medium by column chromatography with DEAE-Sephacel followed by size-exclusion high performance liquid chromatography (HPLC) . A chemical analysis of the S . anginosus antigen (SAA) revealed that it mainly consisted of carbohydrates (rhamnose, N-acetylglucosamine, glucose and galactose), smaller quantities of protein and a trace amount of phosphorus . The SAA stimulated PEC from C57BL/6N mice to produce NO and accumulate induced NO synthetase (iNOS) mRNA in a dose-dependent manner, reaching a plateau with 10-30 microg/ml . Furthermore, a reverse transcription-PCR assay revealed that SAA 10 microg/ml could induce mRNA accumulation of tumour necrosis factor-alpha, interleukin (IL)-1beta and IL-6 as well as iNOS . In contrast, Rantz-Randall antigen (RRA), a carbohydrate antigen prepared from the organisms, could not induce NO synthesis or cause the accumulation of iNOS mRNA, although cytokine production was observed after stimulation . The SAA-induced NO synthesis, but not the cytokine production, was sensitive to heat . Furthermore, an immunoblot analysis of SAA indicated that the 43-kDa protein band reacted with anti-SAA but not anti-RRA antibodies . In immunodiffusion, SAA reacted with both anti-SAA and anti-RRA antibodies, and the precipitin bands formed crossing lines, suggesting that SAA could possess two different antigenic components--one that reacts specificially with anti-SAA antibodies and another that has an identity similar to that of RRA . Taken together, SAA, a novel antigen of S . anginosus, was found to induce NO synthesis as well as produce inflammatory cytokines in murine PEC . It is suggested that the protein molecule of SAA may exclusively induce NO synthesis, and its carbohydrate component(s) could have a relationship to cytokine production.

Clin Infect Dis, 2001 Dec 15, 33(12), E137 - 9 Epub 2001 Nov 05.
Frequency of antibiotic resistance among group B Streptococcus isolated from healthy college students; Manning SD et al.; We report resistant rates to erythromycin and clindamycin among Streptococcus agalactiae (group B Streptococcus) isolated from a random sample of healthy male and nonpregnant female college students . Observed resistance rates were twice as high as those reported among pregnant women from the same geographic area 2 years prior.

J Mol Biol, 2001 Nov 2, 313(4), 797 - 811
The "open" and "closed" structures of the type-C inorganic pyrophosphatases from Bacillus subtilis and Streptococcus gordonii; Ahn S et al.; Recently, a new class of soluble inorganic pyrophosphatase (type-C PPase) has been described that is not homologous in amino acid sequence or kinetic properties to the well-studied PPases (types A and B) found in many organisms from bacteria to humans and thought to be essential to the cell . Structural studies of the type-C PPases from Streptococcus gordonii and Bacillus subtilis reveal a homodimeric structure, with each polypeptide folding into two domains joined by a flexible hinge . The active site, formed at the interface between the N and C-terminal domains, binds two manganese ions approximately 3.6 A apart in a conformation resembling binuclear metal centres found in other hydrolytic enzymes . An activated water molecule bridging the two metal ions is likely poised for nucleophilic attack of the substrate . Importantly, the S . gordonii and B . subtilis enzymes have crystallised in strikingly different conformations . In both subunits of the S . gordonii crystal structure (1.5 A resolution) the C-terminal domain is positioned such that the active site is occluded, with a sulphate ion bound in the active site . In contrast, in the B . subtilis structure (3.0 A resolution) the C-terminal domain is rotated by about 90 degrees, leaving the active site wide open and accessible for substrate binding .

Rev Inst Med Trop Sao Paulo, 2001 Sep-Oct, 43(5), 243 - 6
Group B streptococcal neonatal infections in Rio Grande do Sul, Brazil; Miura E et al.; Group B Streptococcus is the most common pathogen found in neonatal sepsis in North America . OBJECTIVES: We describe 15 cases of neonatal infections by Group B Streptococcus (Streptococcus agalactiae) at a Neonatal Intensive Care Unit of a public and teaching hospital . METHODS: We conducted a study at Hospital de Clinicas de Porto Alegre, from January 1st, 1996 to June 30, 1999 . Diagnosis of neonatal infection was established according to the findings of Group B Streptococcus in blood culture associated with alterations resembling sepsis on the basis of clinical picture and laboratory findings . RESULTS: Fifteen cases of neonatal infections by Group B Streptococcus were detected . Eleven cases consisted of early-onset sepsis, 2 cases of occult bacteremia and 2 cases of late-onset sepsis . Eight cases had septic shock (53%), 8 cases had pneumonia (53%), and 4 cases had meningitis (27%) . Fourteen cases were diagnosed from a positive blood culture, and 1 case from evidence of these bacteria in pulmonary anatomopathological examination . Thirteen cases (87%) were diagnosed before 72 hours of life . We had 3 deaths (20%), and 3 cases of meningitis developing neurological deficits . CONCLUSIONS: Streptococcus Group B is one of the most important pathogens in the etiology of early-onset neonatal sepsis at our hospital, with high mortality and morbidity . However, we do not know the incidence of GBS neonatal infections at other hospitals . More data are needed to establish a basis for trials of different strategies to reduce these infections.

Chemistry, 2001 Oct 15, 7(20), 4411 - 21
Synthesis of Streptococcus pneumoniae type 3 neoglycoproteins varying in oligosaccharide chain length, loading and carrier protein; Lefeber DJ et al.; The preparation is described of a range of neoglycoproteins containing synthesised fragments of the capsular polysaccharide of Streptococcus pneumoniae type 3, that is beta-D-GlcpA-(1-->4)-beta-D-Glcp-(1-->O)-(CH2)3NH2 (1), beta-D-Glcp-(1-->3)-beta-D-GlcpA-(1-->4)-beta-D-Glcp-(1-->O)-(CH2)3NH2 (2), and beta-D-GlcpA-(1-->4)-beta-D-Glcp-(1-->3)-beta-D-GlcpA-(1-->4)-beta-D-Glcp-(1-->O)-(CH4)NH2 (3) . A blockwise approach was developed for the synthesis of the protected carbohydrate chains, in which the carboxylic groups were introduced prior to deprotection by selective oxidation of HO-6 in the presence of HO-4 by using TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy radical) . After deprotection, the 3-aminopropyl spacer of the fragments was elongated with diethyl squarate (3,4-diethoxy-3-cyclobutene-1,2-dione) and the elongated oligosaccharides were conjugated to CRM197 (cross-reacting material of diphtheria toxin), KLH (keyhole limpet hemocyanin) or TT (tetanus toxoid) . The resulting neoglycoconjugates varied in oligosaccharide chain length, oligosaccharide loading and protein carrier . These well-defined conjugates are ideal probes for evaluating the influence of the different structural parameters in immunological tests.

Epidemiol Infect, 2001 Oct, 127(2), 179 - 84
Streptococcal contamination of food: an unusual cause of epidemic pharyngitis; Katzenell U et al.; The purpose of this article is to define the distinguishing characteristics of food-borne streptococcal pharyngitis by reviewing the literature . The main cause of this infection lies in poor handling and preservation of cold salads, usually those which contain eggs and are prepared some hours before serving . A shorter incubation period and a higher attack rate (51-90%) than in transmission by droplets was noted . The epidemics tend to occur in warm climates and in the hottest months of the year . Streptococcus pyogenes seems to originate from the pharynx or hand lesions of a food handler . In comparison to airborne transmission symptoms such as sore throat, pharyngeal erythema, and enlarged tonsils, submandibular lymphadenopathy are more frequent than coughing and coryza . Seven out of 17 reports revealed an M-untypeable serotype, which may possess virulent characteristics . Penicillin prophylaxis was shown to limit additional spread of the infection . There were no non-suppurative sequels, and suppurative sequels were very rare . We assume that the guidelines for the prevention of food poisoning would apply to food-borne streptococcal pharyngitis . Food handlers should be supervised to ensure they comply with strict rules of preparation and storage of food . Cold salads, especially those containing eggs, should not be left overnight before serving.

Int J Antimicrob Agents, 2001 Oct, 18(4), 373 - 8
Clinical isolates of Streptococcus pneumoniae resistant to levofloxacin contain mutations in both gyrA and parC genes; Zheng X et al.; Thirty Streptococcus pneumoniae clinical isolates resistant to levofloxacin were analyzed for the quinolone resistance-determining DNA sequences to identify point mutations and were tested for in vitro susceptibility to multiple drug classes . Of these isolates, 29 had mutations in both gyrA and parC genes of DNA gyrase and topoisomerase IV, respectively . In GyrA, an amino acid change from Ser-81-->Phe was detected in 27 isolates and a Glu-85-->Lys change was found in the remaining three . Of the 29 isolates for which ParC data were available, Ser-79-->Tyr or Phe were the predominant mutations observed . MICs for levofloxacin were 4-16 mg/l, whereas those for moxifloxacin were 1-2 mg/l . Twenty-four (80%) isolates were susceptible to erythromycin, 25 (83%) to azithromycin, 26 (87%) to clarithromycin, 27 (90%) to clindamycin, 20 (67%) to penicillin, 21 (70%) to ceftriaxone and 30 (100%) to amoxycillin/clavulanate . These results confirm the presence of double mutations among clinical isolates of S . pneumoniae from diverse geographical regions of North America and also suggest that quinolone resistance may develop independently of resistance to other drug classes.

Int J Antimicrob Agents, 2001 Oct, 18(4), 341 - 5
Short-course therapy with cefaclor for treatment of streptococcal pharyngotonsillitis; Esposito S et al.; Short-course treatments for streptococcal pharyngotonsillitis with oral cephalosporins or macrolides have resulted in a similar bacteriological and clinical cure rate and better compliance compared with the conventional 10-day course . One hundred and thirty eight of 420 recruited patients had a positive culture for Streptococcus pyogenes and were randomly assigned to receive cefaclor (25 mg/kg/bid) for a 5-day (70 patients) or 10-day (68 patients) course . Patients were assessed clinically and bacteriologically 2-3 days after completing the course and followed up after 20-30 days . All 420 recruited patients belonged to a population of 2800 children who had been previously screened for a streptococcal carrier state to exclude carriers from final evaluation . Clinical cure and bacterial eradication was recorded in 92.8 and 92.6% of patients in groups A and B, respectively . Therefore, short-course therapy with cefaclor may offer an effective alternative treatment to conventional regimens, with potential for better compliance.

Infection, 2001 Oct, 29(5), 289 - 90
Retropharyngeal abscess caused by group B Streptococcus in a previously healthy child; Lo WT et al.; Retropharyngeal cellulitis/abscess has not been recognized as a manifestation of group B streptococcal disease in the pediatric group beyond neonates . The purpose of this paper is to present a previously healthy 3-year-old boy with a retropharyngeal abscess due to group B Streptococcus which was successfully treated by surgical incision and drainage in combination with amoxicillin/clavulanate therapy.

Infection, 2001 Oct, 29(5), 286 - 8
Meningitis in a girl with recurrent otitis media caused by Streptococcus pyogenes--otitis media has to be treated appropriately; Steppberger K et al.; Streptococcus pyogenes rarely causes meningitis . A recent increase in the incidence and severity of diseases due to S . pyogenes has been observed worldwide, without an apparent increase in the incidence of S . pyogenes meningitis . However, more recently severe and fulminant cases of S . pyogenes meningitis have been reported in the literature . This case report emphasizes the fact that S . pyogenes can cause meningitis with severe clinical sequelae such as hygromas and right-sided third cranial nerve palsy . Most importantly, it is concluded that recurrent otitis media has to be treated carefully following appropriate identification of the causing organism in order to prevent severe clinical courses of streptococcal infections.

Clin Microbiol Infect, 2001, 7 Suppl 4, 75 - 82
Linezolid: pharmacokinetic characteristics and clinical studies; Bouza E et al.; Linezolid is an oxazolidinone indicated in the treatment of nosocomial and community-acquired pneumonia, complicated and uncomplicated skin and skin structure infections and vancomycin-resistant Enterococcus infections . The drug is also approved for use in complicated skin infections and nosocomial pneumonia caused by methicillin-resistant Staphylococcus aureus, concurrent bacteremia associated with vancomycin-resistant Enterococcus faecium and concurrent bacteremia associated with community-acquired pneumonia caused by penicillin-susceptible Streptococcus pneumoniae.

Clin Microbiol Infect, 2001, 7 Suppl 4, 34 - 42
Streptococcus pneumoniae as an agent of nosocomial infection: treatment in the era of penicillin-resistant strains; Paradisi F et al.; Streptococcus pneumoniae is a well-known agent of community-acquired infections such as sinusitis, otitis media, pneumonia, bacterial meningitis, bacteremia and acute exacerbations of chronic bronchitis . However, the role of S . pneumoniae as a cause of nosocomial infections of respiratory tract, bloodstream and central nervous system is more and more recognized, primarily in high-risk patients with depression of their immune function . Therapy of pneumococcal infections is made difficult by the emergence and spread of bacterial resistance to penicillin and other beta-lactams as well as to a number of antimicrobials such as macrolides, chloramphenicol, tetracyclines and sulfonamides . This epidemiological situation is a cause for concern world-wide, but it primarily affects some European countries, North America, South Africa and the Far East . The main consequence on therapeutic grounds is that in severe infections such as bacterial meningitis, the addition of vancomycin to a third-generation cephalosporin is advisable while awaiting laboratory test results, even in areas with low prevalence of penicillin-resistant pneumococci . However, a beta-lactam agent can also be a valid choice in the presence of potentially lethal infections such as pneumonia or in the case of penicillin intermediately resistant isolates . In recent years, new alternative molecules have been introduced into clinical practice for therapy of infections caused by penicillin-resistant pneumococci . In both in vivo and in vitro studies, drugs of the classes of fluoroquinolones (levofloxacin, moxifloxacin, gatifloxacin), streptogramins (quinupristin/dalfopristin) and oxazolidinones (linezolid) have shown good microbiologic and clinical efficacy against penicillin-resistant pneumococci . In this era of world-wide spread of penicillin-resistant pneumococci, use of polysaccaride or conjugated vaccines is highly recommended.

J Ind Microbiol Biotechnol, 2001 Oct, 27(4), 259 - 64
Recombinant Escherichia coli engineered for production of L-lactic acid from hexose and pentose sugars; Dien BS et al.; Recombinant Escherichia coli have been constructed for the conversion of glucose as well as pentose sugars into L-lactic acid . The strains carry the lactate dehydrogenase gene from Streptococcus bovis on a low copy number plasmid for production of L-lactate . Three E . coli strains were transformed with the plasmid for producing L-lactic acid . Strains FBR9 and FBR11 were serially transferred 10 times in anaerobic cultures in sugar-limited medium containing glucose or xylose without selective antibiotic . An average of 96% of both FBR9 and FBR11 cells maintained pVALDH1 in anaerobic cultures . The fermentation performances of FBR9, FBR10, and FBR11 were compared in pH-controlled batch fermentations with medium containing 10% w/v glucose . Fermentation results were superior for FBR11, an E . coli B strain, compared to those observed for FBR9 or FBR10 . FBR11 exhausted the glucose within 30 h, and the maximum lactic acid concentration (7.32% w/v) was 93% of the theoretical maximum . The other side-products detected were cell mass and succinic acid (0.5 g/l).

Mt Sinai J Med, 2001 Nov, 68(6), 396 - 9
Pneumococcal vaccine failure in an HIV-infected patient with fatal pneumococcal sepsis and HCV-related cirrhosis; Begemann M et al.; Pneumoccocal vaccination of HIV-positive individuals is recommended to prevent pneumococcal infection . We present a case of a 44-year-old HIV-infected male who came to the emergency room with bacterial pneumonia and sepsis . The patient also had a history of HBV and HCV infection . He expired in the emergency room and blood cultures were positive for Streptococcus pneumoniae . The autopsy confirmed the clinical diagnosis and, in addition, hepatitis C-related cirrhosis and splenic abnormalities . The patient had no history of opportunistic infections . His CD4 count 3 months prior to coming to the emergency room was 216 cells/microL with a viral load of 1,270 copies/mL . The patient had received Pneumovax two years before his death . The organism isolated from blood cultures was Streptococcus pneumoniae isotype 3, a strain included in Pneumovax . This is a case of pneumococcal vaccine failure with a fatal outcome in a person with an HIV infection and hepatitis C-related liver cirrhosis.

Proc Natl Acad Sci U S A, 2001 Nov 6, 98(23), 13335 - 40 Epub 2001 Oct 30.
Use of a dynamic in vitro attachment and invasion system (DIVAS) to determine influence of growth rate on invasion of respiratory epithelial cells by group B Streptococcus; Malin G et al.; Expression of capsular polysaccharide (CPS) and some surface proteins by group B Streptococcus (GBS) is regulated by growth rate . We hypothesized that precise control of GBS growth, and thus surface-expressed components, could modulate the ability of GBS to invade eukaryotic cells . To test this hypothesis, a dynamic in vitro attachment and invasion system (DIVAS) was developed that combines the advantages of bacterial growth in continuous culture with tissue culture . Tissue culture flasks were modified with inlet and outlet ports to permit perfusion of GBS . Encapsulated type III GBS strains M781 and COH1 and strains COH1-11 and COH1-13 (transposon mutants of COH1 that express an asialo CPS or are acapsular, respectively) were grown in continuous culture in a chemically defined medium at fast mass doubling time (t(d) = 1.8 h) and slow (t(d) = 11 h) growth rates, conditions previously shown to induce and repress, respectively, type III CPS expression . Encapsulated GBS strains invaded A549 respiratory epithelial cells 20- to 700-fold better at the fast than at the slow growth rate, suggesting a role for CPS . However, unencapsulated GBS were also invasive but only when cultured at the fast growth rate, which indicates that GBS invasion is independent of CPS expression and can be regulated by growth rate . Growth rate-dependent invasion occurred when GBS was grown in continuous culture under glucose-defined, thiamine-defined, and undefined nutrient limitations . These results suggest a growth rate-dependent regulation of GBS pathogenesis and demonstrate the usefulness of DIVAS as a tool in studies of host-microbe interactions.

Diagn Microbiol Infect Dis, 2001 Sep-Oct, 41(1-2), 89 - 92
Activity of faropenem against resistant isolates of Streptococcus pneumoniae; Black JA et al.; An in vitro study of the activity of 9 agents against 181 US pediatric isolates of Streptococcus pneumoniae identified imipenem and faropenem as the most active agents . Overall, faropenem was the most potent oral agent inhibiting 98% of isolates at 1 microg/mL.

Cochrane Database Syst Rev . 2001;(3):CD002165.
Pneumococcal vaccine for asthma; Sheikh A et al.; BACKGROUND: Infection with Streptococcus pneumoniae is an important cause of pneumonia and other serious illnesses, particularly amongst those with certain high-risk medical conditions such as asthma . Although pneumococcal vaccine is routinely advocated for people with asthma, there is uncertainty about the evidence base that underpins this recommendation . OBJECTIVES: To determine the efficacy of pneumococcal vaccine in reducing mortality or morbidity from pneumococcal disease in asthmatics . SEARCH STRATEGY: Randomised controlled trials were identified using the Cochrane Airways Group's register derived from MEDLINE, EMBASE, and CINAHL electronic databases and hand searched respiratory journals and meeting abstracts . SELECTION CRITERIA: Randomised controlled trials, with or without blinding, in which pneumococcal vaccine has been compared with placebo or no treatment in people with clinician diagnosed asthma . DATA COLLECTION AND ANALYSIS: Two reviewers independently reviewed all abstracts and full papers of all articles of potential relevance were retrieved . Methodological quality was rated using the Cochrane approach and the Jadad rating scale . Data extraction was performed by one reviewer and checked independently by a second . We planned to perform quantitative analyses of outcomes on an intention-to-treat basis, where possible . MAIN RESULTS: Of the three papers retrieved, only one satisfied the inclusion criteria and the methodological quality of this study was low (unblinded and inadequate allocation concealment) . None of the data could be aggregated in a meta-analysis . Comparisons in a sub-set of 30 asthmatic children prone to recurrent episodes of otitis media, showed that pneumococcal vaccination decreased the incidence of acute asthma exacerbations from 10 to 7 (per child per year) . REVIEWER'S CONCLUSIONS: This review found very limited evidence to support the routine use of pneumococcal vaccine in people with asthma . A randomised trial of vaccine efficacy in children and adults with asthma is needed.

Ann Allergy Asthma Immunol, 2001 Oct, 87(4), 327 - 34
Five days of cefprozil versus 10 days of clarithromycin in the treatment of an acute exacerbation of chronic bronchitis; McCarty JM et al.; BACKGROUND: Shorter than traditional 7- to 14-day treatment regimens have demonstrated efficacy in treatment of an acute exacerbation of chronic bronchitis (AECB) . OBJECTIVE: Perform a clinical efficacy study comparing 5 days of cefprozil therapy to 10 days of clarithromycin in treating an AECB . METHODS: A multicenter, randomized, double-blind study comparing efficacy and safety of cefprozil, 500 mg twice daily, for 5 days with clarithromycin, 500 mg twice daily, for 10 days in treatment of 295 subjects with AECB . Concomitantly, among all treated subjects, 39% (115 of 295) had a history of chronic obstructive pulmonary disease/emphysema; 21% (62 of 295) had a history of asthma/reactive airway disease; and 31% (90 of 295) had environmental allergies . RESULTS: There were no statistically significant differences among clinically evaluable subjects' cure rates; 82% (109 of 133) treated with cefprozil versus 85% (105 of 123) treated with clarithromycin were cured at test-of-cure visit (95% confidence interval, -12.0 to 5.1%) . Clinical cure rates at end of study were 80% and 81%, respectively (95% confidence interval, -10.8 to 7.9%) . Before treatment, 99% (85 of 86) of Gram-positive organisms isolated were susceptible to cefprozil and 78% (67 of 86) were susceptible to clarithromycin . A total of 84% (96 of 114) of Gram-negative organisms were susceptible to cefprozil and 63% (72 of 114) were susceptible to clarithromycin . Of clinically evaluable Streptococcus pneumoniae-infected subjects, 100% (11 of 11) of cefprozil subjects and 93% (14 of 15) of clarithromycin subjects experienced clinical cure . The most frequently reported adverse effects were nausea, 5% (7 of 150), and diarrhea, 9% (14 of 150), for cefprozil . For clarithromycin, the adverse effects were nausea, 8% (11 of 145); diarrhea, 12% (18 of 145); taste perversion, 8% (11 of 145); and dry mouth, 5% (7 of 145) . CONCLUSIONS: Five days of cefprozil is as effective as 10 days of clarithromycin for treatment of an AECB.

J Biol Chem, 2001 Dec 28, 276(52), 48831 - 9 Epub 2001 Oct 29.
Expression of the Streptococcus pneumoniae type 3 synthase in Escherichia coli . Assembly of type 3 polysaccharide on a lipid primer; Cartee RT et al.; Synthesis of the type 3 capsular polysaccharide of Streptococcus pneumoniae is catalyzed by the membrane-localized type 3 synthase, which utilizes UDP-Glc and UDP-GlcUA to form high molecular mass {3-beta-d-GlcUA-(1-->4)-beta-d-Glc-(1-->}(n) . Expression of the synthase in Escherichia coli resulted in synthesis of a 40-kDa protein that was reactive with antibody directed against the C terminus of the synthase and was the same size as the native enzyme . Membranes isolated from E . coli contained active synthase, as demonstrated by the ability to incorporate Glc and GlcUA into a high molecular mass polymer that could be degraded by type 3 polysaccharide-specific depolymerase . As in S . pneumoniae, the membrane-bound synthase from E . coli catalyzed a rapid release of enzyme-bound polysaccharide when incubated with either UDP-Glc or UDP-GlcUA alone . The recombinant enzyme expressed in E . coli was capable of releasing all of the polysaccharide from the enzyme, although the chains remained associated with the membrane . The recombinant enzyme was also able to reinitiate polysaccharide synthesis following polymer release by utilizing a lipid primer present in the membranes . At low concentrations of UDP-Glc and UDP-GlcUA (1 microm in the presence of Mg(2+) and 0.2 microm in Mn(2+)), novel glycolipids composed of repeating disaccharides with linkages consistent with type 3 polysaccharide were synthesized . As the concentration of the UDP-sugars was increased, there was a marked transition from glycolipid to polymer formation . At UDP-sugar concentrations of either 5 microm (with Mg(2+)) or 1.5 microm (with Mn(2+)), 80% of the incorporated sugar was in polymer form, and the size of the polymer increased dramatically as the concentration of UDP-sugars was increased . These results suggest a cooperative interaction between the UDP-precursor-binding site(s) and the nascent polysaccharide-binding site, resulting in a non-processive addition of sugars at the lower UDP-sugar concentrations and a processive reaction as the substrate concentrations increase.

Eur J Biochem, 2001 Nov, 268(21), 5570 - 7
Analysis of the interaction of 16S rRNA and cytoplasmic membrane with the C-terminal part of the Streptococcus pneumoniae Era GTPase; Hang JQ et al.; Era, an essential GTPase, plays a regulatory role in several cellular processes . The Era protein of Streptococcus pneumoniae has recently been shown to bind to 16S rRNA and the cytoplasmic membrane . However, exact locations of Era responsible for RNA- and membrane-binding were unknown . To identify the regions in Era that interact with the RNA and membrane, the C-terminal part of S . pneumoniae Era was systematically deleted while the N-terminal part, responsible for the GTPase activity of the protein, was kept intact . The resulting truncated Era proteins were purified and characterized . The C-terminal deletion of 9 or 19 amino-acid residues did not affect 16S rRNA-binding activity while further deletions of the C-terminus (29-114 amino-acid residues) abolished the activity . These results indicate that the integrity of the putative KH domain of Era, spanning the amino-acid residues between approximately 22-83 from the C-terminus, is required for 16S rRNA-binding . Furthermore, the Era proteins with a deletion up to 45 residues from the C-terminus retained membrane-binding activity, but longer deletions significantly reduced the activity . These results indicate that part of the putative KH domain is also required for membrane-binding . Thus, these results indicate for the first time that the regions critical for the membrane- and 16S rRNA-binding activities of Era overlap . The era gene with a deletion of 9 or 19 codons from its 3' terminus complemented an Escherichia coli mutant strain deficient in Era production whereas the genes with longer deletions failed to do so, thereby indicating that the KH domain is essential for Era function . Taken together, the results of this study indicate that the putative KH domain is required for 16S rRNA-binding activity and that part of the KH domain is also required for membrane-binding activity . The results also suggest that the interaction between Era and 16S rRNA is essential for bacterial growth.

Clin Microbiol Infect, 2001 Oct, 7(10), 548 - 52
Epidemiology of penicillin resistance in Streptococcus pneumoniae isolates in Kayseri, Turkey; Esel D et al.; OBJECTIVE: To determine the penicillin resistance and serotype distribution of Streptococcus pneumoniae strains and to identify clonal relationships of isolates resistant to penicillin by means of pulsed-field gel electrophoresis (PFGE) . METHODS: In total, 193 S . pneumoniae strains were isolated from clinical specimens between November 1997 and January 2000 . Susceptibility testing was carried out by E test, and serotyping by the Quellung reaction . Clonal relationship was analyzed by using PFGE with smaI endonuclease . RESULTS: Of the S . pneumoniae isolates, 23% were intermediately resistant to penicillin . There were no high-level resistant pneumococci . The majority of isolates intermediately resistant to penicillin were of serogroups/serotypes 19, 23, 14 and 1, in descending order of frequency . There were eight major clones in strains intermediately resistant to penicillin . It was seen that serogroups in the 23-valent polysaccharide vaccine, 7-valent, 9-valent, and 11-valent vaccine formulations caused 92%, 75%, 78% and 87% of pneumococcal diseases in our region, respectively . CONCLUSION: Penicillin resistance in S . pneumoniae is relatively uncommon in Kayseri . All vaccine formulations can prevent the majority of pneumococcal diseases, and there is genetic heterogeneity in intermediately penicillin-resistant pneumococci in this region.

Auris Nasus Larynx, 2001 May, 28 Suppl, S29 - 32
Therapy for otitis-prone children in Tenshi hospital; Matsumura M et al.; With the recent emergence and increases of multiple-drugs-resistant Streptococcus pneumoniae, we have been seeing an increasing number of infants with intractable recurrent otitis media which is resistant to the general conservative out-patient treatments such as oral administration of medicines or tympanotomy . In this study, we investigated the inflammation-causing bacteria in the infants with otitis media which were treated in our hospital from January to December in 1997, and in six serious cases among them, we measured IgG subclass and specific IgG2 antibody to S . pneumoniae to examine them . As a result, S . pneumoniae was found to be the cause in 45% of the cases of initial development of otitis media, and in 88% of them the S . pneumoniae was penicillin-resistant . The level of specific IgG2 antibody to S . pneumoniae was low in all the cases, whereas IgG2 subclass was deficient only in one out of the six cases; from these findings, the selectively low level of immune status was thought to be the cause of the recurrences of otitis media . In two cases, clinical condition was markedly improved by immunoglobulin substitute therapy, which demonstrates that immunoglobulin is effective for the intractable recurrent otitis media in infants.

Arch Pediatr, 2001 Oct, 8(10), 1050 - 4
{Acute external mastoiditis in children: report of a series of 48 cases}; Francois M et al.; DESIGN: To determine the impact of the emergence of penicillin-resistant strains of pneumococci on the frequency of acute mastoiditis in children, and to assess the importance of laboratory and imaging studies in the treatment of acute mastoiditis . METHOD: Retrospective review of the medical records of children with postauricular swelling and otoscopic signs of acute otitis media from January 1993 through December 2000 . RESULTS: Forty-eight children aged three months to 14 years (median 17 months) were identified . The number of cases was almost the same from one year to another . All children had bacteriological examinations . The mastoid pus and the otorrhea was sterile in 22 cases . The most frequent pathogen was Streptococcus pneumoniae (17 cases), which was resistant to penicillin in 71% of cases . The initial body temperature, the number of polymorphonuclears and the CRP were not different between the group of 18 children with periostitis, which required medical treatment alone, and the group of 30 children who had a mastoid abscess which required surgery . The difference between periostitis and mastoid abscess was seen on clinical examination and CTscan.

J Clin Microbiol, 2001 Nov, 39(11), 4175 - 7
Comparison of automated ribotyping to pulsed-field gel electrophoresis for genetic fingerprinting of Streptococcus pneumoniae; Quale JM et al.; Fifty-two isolates of Streptococcus pneumoniae were characterized by pulsed-field gel electrophoresis (PFGE) and automated ribotyping by using HindIII and PvuII . HindIII ribotypes correlated well with PFGE . PvuII produced fewer bands and was less discriminatory . Automated ribotyping with HindIII is an accurate method for genetic fingerprinting of S . pneumoniae and can complement PFGE.

J Clin Microbiol, 2001 Nov, 39(11), 4052 - 7
DNA relatedness, phenotypic characteristics, and antimicrobial susceptibilities of Globicatella sanguinis strains; Shewmaker PL et al.; DNA-DNA reassociation was performed on 15 strains of Globicatella sanguinis to compare their taxonomic status with phenotypic characterization . All 15 strains selected for DNA-DNA reassociation readily met the criteria for species relatedness . The relative binding ratio was 81% or greater at the optimal temperature and 76% or greater at the stringent temperature, and the divergence was less than 3% for all strains hybridized with the type strain . These strains included nine strains from the Centers for Disease Control Streptococcus Laboratory culture collection that were previously included in comparative 16S rRNA gene sequencing studies as well as six additional phenotypically variant isolates . DNA-DNA relatedness was less than 18% at the optimal reassociation temperature to Aerococcus viridans, Enterococcus avium, and Streptococcus uberis, which are phenotypically similar to G . sanguinis . This study confirms these Globicatella strains were previously misidentified as S . uberis or S . uberis-like strains based on biochemical characteristics . The biochemical data from 28 strains was compiled to further define the phenotypic criteria for identification of this species . A revised description of the species should be variable reaction for pyrrolidonylarylamidase production (75% positive), positive reaction for the bile esculin test (100%), growth at 45 degrees C (96%), variable reaction for acid production from arabinose (45% positive), and negative starch hydrolysis (0% positive) . We also evaluated four rapid identification systems, the Biomerieux rapid ID32 STREP (ID32), the Crystal rapid gram-positive identification (Cry4), the BBL Crystal gram-positive identification (Cry24), and the Remel IDS RapID STR (IDS) systems for their ability to identify these strains.

J Clin Microbiol, 2001 Nov, 39(11), 4013 - 9
Recombinant flagellin A proteins from Borrelia burgdorferi sensu stricto, B . afzelii, and B . garinii in serodiagnosis of Lyme borreliosis; Panelius J et al.; Genes for flagellin A (FlaA) proteins from European borrelial strains of Borrelia burgdorferi sensu stricto, B . afzelii, and B . garinii were cloned and sequenced . An identity of 92 to 93% was observed in the flaA sequences of the different species . Polyhistidine-tagged recombinant FlaA (rFlaA) proteins were produced in Escherichia coli and used as antigens in Western blotting (WB) and enzyme-linked immunosorbent assay (ELISA) . In immunoglobulin G (IgG) WB, 71% (10 of 14) of the sera from neuroborreliosis and 86% (12 of 14) of those from Lyme arthritis patients reacted with one to three rFlaAs . In IgG ELISA, 74% (14 of 19) and 79% (15 of 19) of patients with neuroborreliosis and arthritis, respectively, were positive . The immunoreactivity in local European patient sera was stronger against rFlaA from B . garinii and B . afzelii than against rFlaA from B . burgdorferi sensu stricto . Neither IgG nor IgM ELISA was sensitive in the serodiagnosis of erythema migrans . Serum samples from patients with syphilis and systemic lupus erythematosus showed mild cross-reactivity in IgG tests . Sera from Yersinia enterocolitica or beta-hemolytic Streptococcus infections showed only occasional responses . With IgM ELISA, 58% (11 of 19) and 37% (7 of 19) of patients with neuroborreliosis and arthritis, respectively, were positive . Cross-reactive antibodies to FlaA, especially in serum samples from patients with rheumatoid factor positivity and Epstein-Barr virus infection, reduced the specificity of IgM serodiagnosis . Therefore, rFlaA seems to have a limited role for IgM serodiagnosis, yet rFlaA might be useful in the IgG serodiagnosis of disseminated Lyme borreliosis.

FEMS Microbiol Lett, 2001 Oct 16, 204(1), 23 - 8
HtrA protease and processing of extracellular proteins of Streptococcus mutans; Diaz-Torres ML et al.; A homologue of the HtrA family of stress-response proteases was detected by analysis of the Streptococcus mutans genome sequence . Disabling of the S . mutans htrA gene by insertional inactivation resulted in bacterial clumping in liquid medium, altered colony morphology and a reduced ability to withstand high temperature, extremes of pH or oxidative stress . Seven different extracellular or wall-associated proteins that are known to be subject to post-translational proteolysis were examined in cultures of wild-type S . mutans and an htrA mutant . Inactivation of the htrA protease had no effect on degradation of the proteins.

Proteomics, 2001 Apr, 1(4), 480 - 93
Extracellular proteins of Staphylococcus aureus and the role of SarA and sigma B; Ziebandt AK et al.; Staphylococcus aureus synthesizes a large number of extracellular proteins that have been postulated to play a role in bacterial virulence . The proteomic approach was used to analyse the pattern of extracellular proteins of two different S . aureus strains, RN6390 and COL . Thirty-nine protein spots were identified by N-terminal sequencing or MALDI-TOF-MS . The differences of the extracellular protein patterns between both strains are striking . Among the 18 proteins identified in S . aureus COL there are nine proteins not yet discovered in S . aureus RN6390 . These are enterotoxin B, leukotoxin D, enterotoxin, serin proteases (SplA and SplC), thermonuclease, an IgG binding protein and two so far unknown proteins in S . aureus with similarities to SceD precursor in Staphylococcus carnosus and to synergohymenotropic toxin precursor in Streptococcus intermedius . In contrast, lipase as well as staphylokinase identified in S . aureus RN6390 were not detectable in S . aureus COL under the same conditions . By using a regulatory mutant of sarA (ALC136) isogenic to strain RN6390 we identified five proteins positively regulated by SarA and 12 proteins negatively regulated by SarA . Besides V8 protease (StsP) and Hlb already described to be regulated by the sar locus new putatively sarA-dependent proteins were identified, e.g . glycerolester hydrolase and autolysin both down-regulated in the sarA mutant, and aureolysin, staphylokinase, staphopain and format tetrahydrofolate lyase up-regulated in the mutant . Moreover, the role of sigma B in expression of extracellular proteins was studied . Interestingly, we found 11 proteins at an enhanced level in a sigB mutant of S . aureus COL, among them enterotoxin B, alpha and beta hemolysin, serine proteases SplA and SplB, leukotoxin D, and staphopain homologues . The sigma B-dependent repression of gene expression occurs at the transcriptional level . Only one protein, SceD, was identified whose synthesis was down-regulated in the mutant indicating that its gene belongs to the sigma B-dependent general stress regulon.

Med Clin North Am, 2001 Nov, 85(6), 1367 - 79
Streptococcus pneumoniae in community-acquired pneumonia . How important is drug resistance?
Bauer T, Ewig S, Marcos MA, Schultze-Werninghaus G, Torres A.
Patients hospitalized with community-acquired pneumonia caused by S . pneumoniae strains with intermediate susceptibility to penicillin according to the conventional definition respond well to treatment with adequate doses of beta-lactam antibiotics . All studies currently available comparing mortality between patients with pneumonia caused by nonsusceptible and susceptible pneumococci agree that resistance of MIC 2 mg/L is not associated independently with an increased mortality . Most but not all studies could not prove an effect of microbial resistance on morbidity . There are data suggesting, however, that pneumococcal pneumonia caused by highly resistant strains (MIC > or = 4 mg/L) does affect the outcome . Pneumococcal resistance remains a matter of concern . Most reports show an increase not only of resistance rates, but also of the proportion of highly resistant strains . The selection of initial empirical antimicrobial treatment of patients with community-acquired pneumonia should be performed judiciously . Because the serum and pulmonary levels achieved with penicillin or related drugs are several times higher than the MICs of most strains, pneumonias caused by S . pneumoniae currently defined as not susceptible to penicillin should respond well to treatment with a beta-lactam antibiotic, used in optimal doses . Consequently, there is no reason fundamentally to change the current approach to initial empiric antimicrobial treatment of patients with community-acquired pneumonia . Nevertheless, increases in resistance to macrolides may prompt a limited use of these drugs in the outpatient setting . In any case, treatment failures may occur at higher levels of resistance, and a change in the definition of susceptibility categories toward higher cutoffs for S . pneumoniae seems to be reasonable.

Jpn J Antibiot, 2001 Aug, 54(8), 401 - 47
{Nationwide sensitivity surveillance of various antibiotic activities against bacteria isolated from patients with severe infections}; Ichiyama S et al.; The susceptibility of 3,058 bacterial strains isolated between January and March, 1997 from patients with severe infections in Japan to ciprofloxacin and other injectable antimicrobial agents was measured using broth microdilution method . Methicillin-resistant Staphylococcus aureus (MRSA) strains were generally sensitive to vancomycin, teicoplanin and arbekacin, and resistant to CPFX and other antibacterial agents . MIC90 of CPFX against Streptococcus pneumoniae, to which MIC of ampicillin was more than 4 micrograms/mL, was below 2 micrograms/mL . PRSP (Penicillin resistant S . pneumoniae), which was also resistant to cephalosporins and carbapenems, showed no cross-resistance to CPFX . The susceptibility of Gram-negative bacteria to CPFX was as high as that to carbapenems . Especially, MIC90 against Pseudomonas aeruginosa was 2 micrograms/mL . 3 strains of isolated 446 P . aeruginosa strains had blaIMP gene . CPFX and pazufloxacin demonstrated good susceptibility with 0.25 microgram/mL of MIC to 2 strains of these 3 strains . The susceptibility rate of the most common isolates from patients suffering from lower respiratory tract infections excluding MRSA to CPFX was more than 80% (indication: % strains < pneumonia break point).

J Infect Dis, 2001 Nov 15, 184(10), 1345 - 9 Epub 2001 Oct 15.
Opsonic phagocytosis of Streptococcus pneumoniae by alveolar macrophages is not impaired in human immunodeficiency virus-infected Malawian adults; Gordon SB et al.; Streptococcus pneumoniae is a major cause of pneumonia, bacteremia, and meningitis, especially among adults infected with the human immunodeficiency virus (HIV) . Alveolar macrophages (AMs) are critical components of cellular defense against bacterial infection and are both infected and affected by HIV . In this study, AMs obtained at bronchoscopy from 44 Malawian adults (24 HIV positive and 20 HIV negative) were exposed in vitro to opsonized S . pneumoniae and coagulase-negative staphylococci . AMs from HIV-positive and -negative volunteers showed no significant difference in binding to or internalization of either S . pneumoniae or coagulase-negative staphylococci . In HIV-positive subjects, the presence of detectable HIV in lung fluid was not associated with AM impairment . AMs from HIV-infected adults did not exhibit impaired pneumococcal phagocytosis in the assay used . This suggests that an alternative mechanism of susceptibility is operating in these individuals.

J Infect Dis, 2001 Nov 15, 184(10), 1300 - 9 Epub 2001 Oct 15.
Apoptosis-inducing factor mediates microglial and neuronal apoptosis caused by pneumococcus; Braun JS et al.; Streptococcus pneumoniae is the major cause of bacterial meningitis and it damages the hippocampus by inducing neuronal apoptosis . The blocking of caspases provides only partial protection in experimental meningitis, which suggests that there is an additional apoptotic pathway . A trigger of this pathway is the bacterium itself, as exposure of microglia or neurons to live pneumococci induces rapid apoptosis . In this study, apoptosis was not associated with the activation of caspases-1-10 and was not inhibited by z-VAD-fmk, a broad-spectrum caspase inhibitor . Rather, apoptosis was attributed to damage to mitochondria, which was followed by the release of apoptosis-inducing factor (AIF) from the mitochondria, large-scale DNA fragmentation, and hypodiploidy . Furthermore, intracytoplasmatic microinjection of AIF-specific antiserum markedly impaired pneumococcus-induced apoptosis . These findings indicate that AIF may play a central role in brain cell apoptosis and bacterial pathogenesis.

Acta Crystallogr D Biol Crystallogr, 2001 Nov, 57(Pt 11), 1747 - 51 Epub 2001 Oct 25.
Streptococcus pneumonia YlxR at 1.35 A shows a putative new fold; Osipiuk J et al.; The structure of the YlxR protein of unknown function from Streptococcus pneumonia was determined to 1.35 A . YlxR is expressed from the nusA/infB operon in bacteria and belongs to a small protein family (COG2740) that shares a conserved sequence motif GRGA(Y/W) . The family shows no significant amino-acid sequence similarity with other proteins . Three-wavelength diffraction MAD data were collected to 1.7 A from orthorhombic crystals using synchrotron radiation and the structure was determined using a semi-automated approach . The YlxR structure resembles a two-layer alpha/beta sandwich with the overall shape of a cylinder and shows no structural homology to proteins of known structure . Structural analysis revealed that the YlxR structure represents a new protein fold that belongs to the alpha-beta plait superfamily . The distribution of the electrostatic surface potential shows a large positively charged patch on one side of the protein, a feature often found in nucleic acid-binding proteins . Three sulfate ions bind to this positively charged surface . Analysis of potential binding sites uncovered several substantial clefts, with the largest spanning 3/4 of the protein . A similar distribution of binding sites and a large sharply bent cleft are observed in RNA-binding proteins that are unrelated in sequence and structure . It is proposed that YlxR is an RNA-binding protein.

J Antimicrob Chemother, 2001 Nov, 48(5), 731 - 4
Emergence of extremely high penicillin and cefotaxime resistance and high-level levofloxacin resistance in clinical isolates of Streptococcus pneumoniae in Hungary; Glatz K et al.; Oxacillin disc diffusion tests revealed that 36.7% of 327 Hungarian Streptococcus pneumoniae strains from clinical specimens were not penicillin susceptible . Determination of the MICs of penicillin, cefotaxime and levofloxacin for these strains by Etest confirmed that 30 (9.2%), 19 (5.8%) and four to 11 (1.2-3.4%) were fully penicillin-, cefotaxime- and levofloxacin-resistant, respectively . Most had extremely high MICs . Lower respiratory tract strains were more resistant than those from the upper respiratory tract . Levofloxacin-resistant strains were either penicillin intermediate or resistant, but their MICs did not correlate strongly.

J Antimicrob Chemother, 2001 Nov, 48(5), 659 - 65
Increasing resistance of Streptococcus pneumoniae to fluoroquinolones: results of a Hong Kong multicentre study in 2000; Ho PL et al.; The MICs of 13 antimicrobial agents including seven fluoroquinolones (ciprofloxacin, levofloxacin, sparfloxacin, grepafloxacin, gatifloxacin, moxifloxacin and clinafloxacin) for Streptococcus pneumoniae isolates obtained from all regions of Hong Kong in the year 2000 were determined by the Etest . Overall, 39.4% of 180 isolates were susceptible to penicillin, 11.7% were intermediate and 48.9% were resistant . The overall prevalence of fluoroquinolone non-susceptibility (levofloxacin MIC > or = 4 mg/L) was 13.3% but increased to 27.3% among the penicillin-resistant isolates . For the fluoroquinolone non-susceptible isolates, within-class cross-resistance was common . For the fluoroquinolone non-susceptible isolates, the median MICs of clinafloxacin, gatifloxacin, moxifloxacin, sparfloxacin and grepafloxacin were, respectively, six-, 24-, 32- 84- and 128-fold higher than those for the susceptible isolates . All fluoroquinolone non-susceptible strains were derived from adults . The prevalence of fluoroquinolone resistance was higher in isolates from older patients (17.1% among those > or = 65 years of age versus 9.1% among those 18-64 years of age, P < 0.001) and from adults with chronic obstructive pulmonary disease (24.6% versus 9.3%, P = 0.01) . All fluoroquinolone non-susceptible strains were non-susceptible to penicillin (MIC range 2-4 mg/L), cefotaxime (MIC range 1-4 mg/L) and erythromycin (MIC range 4- > or = 256 mg/L) . The fluoroquinolone non-susceptible isolates were genetically related to the Spain(23F)-1 clone when analysed by pulse-field gel electrophoresis and multilocus sequence typing . In conclusion, a rapid increase in the prevalence of fluoroquinolone resistance among S . pneumoniae was found in Hong Kong . Typing analysis suggests that this is due to the pan-regional dissemination of a fluoroquinolone-resistant variant (designated Hong Kong(23F)-1) of the globally distributed Spain(23)F-1 clone.

J Antimicrob Chemother, 2001 Nov, 48(5), 609 - 15
Comparison of antimicrobial in vitro activities against Streptococcus pneumoniae independent of MIC susceptibility breakpoints using MIC frequency distribution curves, scattergrams and linear regression analyses; Fass RJ et al.; Comparing in vitro activities of antimicrobial agents against Streptococcus pneumoniae using per cent susceptible to recommended MIC breakpoints is not optimal . In this study, MICs of penicillin G, ampicillin/sulbactam, ceftriaxone, cefuroxime, erythromycin, tetracycline, trimethoprim/sulfamethoxazole, ciprofloxacin, levofloxacin, trovafloxacin and moxifloxacin were determined for 646 strains . Drug activities were compared using MIC frequency distribution curves, scattergrams and linear regression analyses of MICs (log2) . MIC frequency distributions did not always correspond to recommended breakpoints for distinguishing susceptible, intermediate and resistant strains . Penicillin G, ampicillin/sulbactam and ceftriaxone had similar activities and were each c . 1-1.5 dilution steps more active than cefuroxime . For all beta-lactam drug pairs, there was a high correlation of MICs with regression line slopes (a approximately equal to 1) and coefficients of determination (R(2) = 0.90-0.97) . Although beta-lactam-resistant strains were more likely to be resistant to erythromycin, tetracycline and/or trimethoprim/sulfamethoxazole than were beta-lactam-susceptible strains, MIC correlations were relatively poor (R(2) = 0.14-0.46), as they were when the non-beta-lactam drugs were compared with each other (R(2) = 0.10-0.25) . Trovafloxacin and moxifloxacin were each c . 2.5 dilution steps more active than ciprofloxacin and levofloxacin . There was no correlation of quinolone MICs with MICs of any other drug class (R(2) 0.02) . Among the quinolones, however, there was a high correlation of MICs with a approximately equal to 1 and R(2) = 0.81-0.92 . With the quinolone drug pairs, lines of best fit were second-order polynomial equations, consistent with a dissociation of low level resistance mechanisms . In summary, beta-lactam and quinolone MICs were predictable within drug classes and testing multiple derivatives within each class is probably not necessary . Although there was some relationship between beta-lactam, erythromycin, tetracycline and trimethoprim/sulfamethoxazole MICs, predictability of MICs between drug classes was poor . There was no relationship between quinolone MICs and MICs of any of the other drugs tested.

Appl Environ Microbiol, 2001 Nov, 67(11), 5190 - 6
An rpsL cassette, janus, for gene replacement through negative selection in Streptococcus pneumoniae; Sung CK et al.; Natural genetic transformation offers a direct route by which synthetic gene constructs can be placed into the single circular chromosome of Streptococcus pneumoniae . However, the lack of a general negative-selection marker has hampered the introduction of constructs that do not confer a selectable phenotype . A 1.3-kb cassette was constructed comprising a kanamycin (Kn) resistance marker (kan) and a counterselectable rpsL(+) marker . The cassette conferred dominant streptomycin (Sm) sensitivity in an Sm-resistant background in S . pneumoniae . It was demonstrated that it could be used in a two-step transformation procedure to place DNA of arbitrary sequence at a chosen target site . The first transformation into an Sm-resistant strain used the cassette to tag a target gene on the chromosome by homologous recombination while conferring Kn resistance but Sm sensitivity on the recombinant . Replacement of the cassette by an arbitrary segment of DNA during a second transformation restored Sm resistance (and Kn sensitivity), allowing construction of silent mutations and deletions or other gene replacements which lack a selectable phenotype . It was also shown that gene conversion occurred between the two rpsL alleles in a process that depended on recA and that was susceptible to correction by mismatch repair.

Mol Microbiol, 2001 Oct, 42(1), 145 - 57
Mutation of luxS affects growth and virulence factor expression in Streptococcus pyogenes; Lyon WR et al.; Adaptive responses of bacteria that involve sensing the presence of other bacteria are often critical for proliferation and the expression of virulence characteristics . The autoinducer II (AI-2) pathway has recently been shown to be a mechanism for sensing other bacteria that is highly conserved among diverse bacterial species, including Gram-positive pathogens . However, a role for this pathway in the regulation of virulence factors in Gram-positive pathogens has yet to be established . In this study, we have inactivated luxS, an essential component of the AI-2 pathway, in the Gram-positive pathogen Streptococcus pyogenes . Analyses of the resulting mutants revealed the aberrant expression of several virulence properties that are regulated in response to growth phase, including enhanced haemolytic activity, and a dramatic reduction in the expression of secreted proteolytic activity . This latter defect was associated with a reduced ability to secrete and process the precursor of the cysteine protease (SpeB) as well as a difference in the timing of expression of the protease . Enhanced haemolytic activity of the luxS strain was also shown to be linked with an increased expression of the haemolysin S-associated gene sagA . Disruptions of luxS in these mutants also produced a media-dependent growth defect . Finally, an allelic replacement analysis of an S . pyogenes strain with a naturally occurring insertion of IS1239 in luxS suggested a mechanism for modulation of virulence during infection . Results from this study suggest that luxS makes an important contribution to the regulation of S . pyogenes virulence factors.

Mol Microbiol, 2001 Oct, 42(1), 61 - 74
Regulation of capsule gene expression by group A Streptococcus during pharyngeal colonization and invasive infection; Gryllos I et al.; Capsular polysaccharide production by group A Streptococcus (GAS) is controlled by transcription of the has operon that encodes the enzymes uniquely required for synthesis of the hyaluronic acid polysaccharide . To investigate the regulation of capsule gene expression during infection, we developed a reporter strain of GAS in which the has operon promoter directed transcription of green fluorescent protein (GFP) . Gfp expression was triggered within minutes after introduction of the reporter strain into the peritoneal cavity of mice, as evidenced by the recovery of highly fluorescent GAS from the peritoneum 1 h after challenge . Capsule gene expression was also stimulated in the bloodstream of infected mice, as intensely fluorescent bacteria were observed in blood samples collected after either intraperitoneal or intravenous challenge . Using a similar approach, we also observed rapid induction of capsule gene expression in bacteria inoculated into the pharynx of baboons . Compared to the inoculum, increased green fluorescence was recorded in bacteria recovered from throat swabs collected 1 h after inoculation in all five animals studied . We conclude that introduction of GAS into the pharynx or into deep tissues results in rapid induction of has operon expression, a critical adaptive response that enhances GAS survival in the infected host.

Clin Microbiol Infect, 2001 Sep, 7(9), 503 - 6
Activity of quinupristin-dalfopristin in invasive isolates of Streptococcus pneumoniae from Italy; Pantosti A et al.; Eighty-five recent isolates of Streptococcus pneumoniae from patients with invasive disease were examined for their susceptibility to erythromycin, clindamycin, penicillin and quinupristin-dalfopristin by E test . A novel duplex PCR assay was used to detect the presence of the erm(B) or mef(A) genes in all of the erythromycin-resistant isolates . All of the strains tested were susceptible to the combination quinupristin-dalfopristin, regardless of their susceptibility to penicillin or to erythromycin . By duplex PCR, two-thirds of the erythromycin-resistant strains harbored erm, and one-third harbored mef . The activity of quinupristin-dalfopristin was not influenced by the genetic determinant of erythromycin resistance . The in vitro susceptibility of S . pneumoniae to quinupristin-dalfopristin is promising for future use; however, it is important to monitor the possible emergence of resistance.

Clin Microbiol Infect, 2001 Sep, 7(9), 486 - 91
The DUEL study: a multi-center in vitro evaluation of linezolid compared with other antibiotics in the Netherlands; Mouton JW et al.; OBJECTIVE: To evaluate bacterial susceptibility to linezolid in the Netherlands in comparison with other antibiotics . METHODS: Bacterial strains were isolated between September 1999 and January 2000 from patients presumed to require antibiotic treatment . The in vitro activity of 1226 strains from 34 participating laboratories was tested against linezolid, vancomycin, teicoplanin, oxacillin, penicillin, erythromycin, ampicillin and other antibiotics against enterococci, coagulase-negative staphylococci, Staphylococcus aureus and Streptococcus pneumoniae . Minimal inhibitory concentrations (MIC) were obtained with the E test on Mueller-Hinton agar: every laboratory included control strains . For vancomycin and teicoplanin only, brain-heart infusion agar and an inoculum of 2.0 McFarland was used for Staphylococcus aureus, coagulase-negative staphylococci and enterococci to support a better growth and clear recognition of hetero-resistant colonies . RESULTS: The values of MIC90 for linezolid were 1.5, 0.75, 0.75 and 1 mg/L for Staphylococcus aureus, coagulase-negative staphylococci, Streptococcus pneumoniae and enterococci, respectively . Six enterococcal strains with decreased susceptibility against vancomycin or teicoplanin were identified as Enterococcus faecium, E . gallinarum and E . casseliflavus (two strains each) and they were found to harbor vanA, vanC1 and vanC2/3 genes, respectively . Nine per cent of Streptococcus pneumoniae (an increase from 1% 4 years ago) showed decreased susceptibility to erythromycin, of both the ermB and mefE type; there was no cross-resistance with linezolid . Twelve coagulase-negative staphylococcal strains were resistant to teicoplanin . CONCLUSION: Linezolid is a promising drug in the treatment of infections caused by Gram-positive cocci . Cross-resistance with other antibiotics tested was not found.

West Indian Med J, 2001 Jun, 50(2), 130 - 2
Evaluation of neonatal sepsis screening in a tropical area Part III: Neonatal sepsis in meconium stained deliveries; Robillard PY et al.; Of the 6,060 consecutive live births delivered at the University Maternity Unit of Guadeloupe (French West Indies) during a 30-month period, 635 newborns (10.4%) presented with meconium stained (MS) amniotic fluid, of which 595 (94%) received bacteriological screening at birth (light MS, n = 543; thick MS, n = 52) . Thirty (5%) of MS newborns had a bacteraemia (n = 13, group B streptococcus, GBS), and 128 (21.5%) a bacterial positive gastric aspirate (n = 54, GBS) . Sixty-six newborns among MS babies needed tracheal suctioning (11%) in the delivery room for meconium inhalation . Among these 595 screened MS newborns, 286 (48%) presented clinical signs of postmaturity at birth, having therefore an explanation for their MS condition . For the other MS newborns without the postmaturity explanation, we experienced twofold increased risk of neonatal sepsis (OR 1.88 for bacteraemia and 2.61 for external carriage p < 0.02, Chi square) as compared with their MS postmature counterparts . We conclude that when meconium stained deliveries are associated with postmaturity signs, one may not need to initiate prophylactic antibiotic treatment at birth unless they present with other traditional risk factors for neonatal sepsis such as intrapartum fever and prolonged rupture of membranes.

JAMA, 2001 Oct 17, 286(15), 1857 - 62
Macrolide resistance among invasive Streptococcus pneumoniae isolates; Hyde TB et al.; CONTEXT: Macrolide antibiotics, including erythromycin, clarithromycin, and azithromycin, are the mainstays of empirical pneumonia therapy . Macrolide resistance among Streptococcus pneumoniae, the most common cause of community-acquired pneumonia, is increasing in the United States . Whether resistance is a significant problem or whether macrolides remain useful for treatment of most resistant strains is unknown . OBJECTIVE: To examine the epidemiology of macrolide-resistant pneumococci in the United States . DESIGN AND SETTING: Analysis of 15 481 invasive isolates from 1995 to 1999 collected by the Centers for Disease Control and Prevention's Active Bacterial Core surveillance system in 8 states . MAIN OUTCOME MEASURES: Trends in macrolide use (1993-1999) and resistance and factors associated with resistance, including examination of 2 subtypes, the M phenotype, associated with moderate minimum inhibitory concentrations (MICs), and the MLS(B) phenotype, associated with high MICs and clindamycin resistance . RESULTS: From 1993 to 1999, macrolide use increased 13%; macrolide use increased 320% among children younger than 5 years . Macrolide resistance increased from 10.6% in 1995 to 20.4% in 1999 . M phenotype isolates increased from 7.4% to 16.5% (P<.001), while the proportion with the MLS(B) phenotype was stable (3%-4%) . The median erythromycin MIC (MIC(50)) of M phenotype isolates increased from 4 microg/mL to 8 microg/mL . In 1999, M phenotype strains were more often from children than persons 5 years or older (25.2% vs 12.6%; P<.001) and from whites than blacks (19.3% vs 11.2%; P<.001) . CONCLUSIONS: In the setting of increasing macrolide use, pneumococcal resistance has become common . Most resistant strains have MICs in the range in which treatment failures have been reported . Further study and surveillance are critical to understanding the clinical implications of our findings.

J Immunol, 2001 Nov 1, 167(9), 5240 - 6
TNF-alpha compensates for the impaired host defense of IL-1 type I receptor-deficient mice during pneumococcal pneumonia; Rijneveld AW et al.; To determine the role of IL-1 in the host defense against pneumonia, IL-1R type I-deficient (IL-1R(-/-)) and wild-type (Wt) mice were intranasally inoculated with Streptococcus pneumoniae . Pneumonia resulted in elevated IL-1alpha and IL-1beta mRNA and protein levels in the lungs . Survival rates did not differ between IL-1R(-/-) and Wt mice after inoculation with 5 x 10(4) or 2 x 10(5) CFU . At early time points (24 and 48 h) IL-1R(-/-) mice had 2-log more S . pneumoniae CFU in lungs than Wt mice; at 72 h bacterial outgrowth in lungs was similar in both groups . Upon histopathologic examination IL-1R(-/-) mice displayed a reduced capacity to form inflammatory infiltrates at 24 h after the induction of pneumonia . IL-1R(-/-) mice also had significantly less granulocyte influx in bronchoalveolar lavage fluid at 24 h after inoculation . Since TNF is known to enhance host defense during pneumonia, we determined the role of endogenous TNF in the early impairment and subsequent recovery of defense mechanisms in IL-1R(-/-) mice . All IL-1R(-/-) mice treated with anti-TNF rapidly died (no survivors (of 14 mice) after 4 days), while 10-day survival in IL-1R(-/-) mice (control Ab), Wt mice (anti-TNF), and Wt mice (control Ab) was 7 of 13, 3 of 14, and 12 of 13, respectively . These data suggest that TNF is more important for host defense against pneumococcal pneumonia than IL-1, and that the impaired early host defense in IL-1R(-/-) mice is compensated for by TNF at a later phase.

Int J Antimicrob Agents, 2001 Sep, 18(3), 231 - 8
Influence of diminished susceptibility of Streptococcus pneumoniae to ciprofloxacin on the serum bactericidal activity of gemifloxacin and trovafloxacin after a single dose in healthy volunteers; Prieto J et al.; The serum bactericidal activity against 2 Streptococcus pneumoniae strains (ciprofloxacin MIC 1 and 4 mg/l) was measured in 12 volunteers who received oral single doses of gemifloxacin 320 mg and trovafloxacin 200 mg in a crossover fashion . The 4-fold increase in ciprofloxacin MIC from the susceptible to the resistant strain resulted in a 2-fold increase in MIC (from 0.015 to 0.03 mg/l), a 2-fold decrease in C(max)/MIC (104 vs 52) and in AUC(0-24 h)/MIC (532 vs 266), but a 5.6-fold decrease in area under the bactericidal curve (AUBC: 168 vs 30) for gemifloxacin . Trovafloxacin showed a 4-fold higher MIC (0.25 vs 0.06 mg/l), a 4-fold lower C(max)/MIC (8.6 vs 36), a 4-fold lower AUC(0-24 h)/MIC (85 vs 356) and a 11-fold lower AUBCs (2 vs 22) against the resistant isolate compared with the susceptible one . Trovafloxacin serum bactericidal titres against the ciprofloxacin-resistant strain were measurable generally only at 1 h after dosing (median titre=2) . Gemifloxacin showed similar ex vivo bactericidal activity against the ciprofloxacin-resistant strain to that of trovafloxacin against the ciprofloxacin-susceptible strain.

Scand J Infect Dis, 2001, 33(9), 708 - 10
Group B Streptococcal sacroiliitis: case report and review; Corominas H et al.; Streptococcus agalactiae, or group B Streptococcus (GBS), is the major cause of neonatal meningitis and sepsis but is an uncommon infection in adults . GBS arthritis is rare, and axial involvement with sacroiliitis is even more uncommon . Microbiological diagnosis frequently relies upon positive blood cultures as synovial fluid cultures are usually negative . Severe joint damage may result due to delay in the initiation of antibiotic treatment.

Pediatr Infect Dis J, 2001 Oct, 20(10), 959 - 67
Evolution of Streptococcus pneumoniae serotypes and penicillin susceptibility in Latin America, Sireva-Vigía Group, 1993 to 1999 . PAHO Sireva-Vigía Study Group . Pan American Health Organization; Di Fabio JL et al.; BACKGROUND: Since 1993 the Pan American Health Organization has coordinated a surveillance network with the National Reference Laboratories of Argentina, Brazil, Chile, Colombia, Mexico and Uruguay aimed at monitoring capsular types and antimicrobial susceptibility of Streptococcus pneumoniae causing invasive disease in children <6 years of age . METHODS: The surveillance system included children 6 years of age and younger with invasive disease caused by S . pneumoniae . The identification, capsular typing and susceptibility to penicillin of the isolates were conducted using a common protocol, based on standard methodologies . RESULTS: By June, 1999, 4,105 invasive pneumococcal isolates had been collected mainly from pneumonia (44.1%) and meningitis (41.1%) cases . Thirteen capsular types accounting for 86.1% of the isolates (14, 6A/6B, 5, 1, 23F, 19F, 18C, 19A, 9V, 7F, 3, 9N and 4) remained the most common types during the surveillance period . Diminished susceptibility to penicillin was detected in 28.6% of the isolates, 17.3% with intermediate and 11.3% with high level resistance . Resistance varied among countries and increased during this period in Argentina, Colombia and Uruguay . Serotypes 14 and 23F accounted for 66.6% of the resistance . CONCLUSION: These surveillance data clearly demonstrate the potential impact of the introduction of a conjugate vaccine on pneumococcal disease and the need for more judicious use of antibiotics to slow or reverse the development of antimicrobial resistance.

Pediatr Infect Dis J, 2001 Oct, 20(10), 946 - 50
Invasive pneumococcal infections in pediatric cardiac transplant patients; Stovall SH et al.; BACKGROUND: Bacterial infections cause significant morbidity and mortality in cardiac transplant patients . Because Streptococcus pneumoniae is the most prominent bacterial pathogen of childhood, the objective of this study was to define the role of S . pneumoniae as a pathogen in the cardiac transplant population . METHODS: Medical records of cardiac transplant patients from March, 1990, through November, 2000, were reviewed to identify invasive pneumococcal infections after transplantation . Demographic, clinical and microbiologic data were reviewed . RESULTS: Nine (11%) of 80 patients had 12 episodes of pneumococcal bacteremia for an incidence rate of 39 cases/1,000 patient years . Patients who were African-American, transplanted before 2 years of age and transplanted because of idiopathic dilated cardiomyopathy were at increased risk of invasive pneumococcal disease (P < 0.05) . Six patients were eligible for the 23-valent pneumococcal polysaccharide vaccine before their first invasive infection, but only 1 had received it at the recommended age . Most isolates (82%) were penicillin-susceptible, and no single serotype predominated . There were 2 deaths in the study group, but each was unrelated to infection . Three patients (33%) had recurrent invasive disease with a second serotype an average of 12 months after the first infection . CONCLUSIONS: The incidence of pneumococcal bacteremia in cardiac transplant patients is higher than in the general pediatric population . Risks for infection were being African-American, being younger than 2 years at the time of transplant and being transplanted because of idiopathic cardiomyopathy . It is plausible that pneumococcal vaccine would decrease this risk.

Pediatr Infect Dis J, 2001 Oct, 20(10), 1009 - 10
Failure of the conjugate pneumococcal vaccine to prevent recurrent bacteremia in a child with human immunodeficiency virus disease; Schutze GE et al.; Patients with advanced HIV disease have a poor response to some immunizations . A case is presented of a Class C1 HIV-infected child who suffered three episodes of Streptococcus pneumoniae serotype 6B bacteremia despite having received the heptavalent conjugate and 23-valent polysaccharide pneumococcal vaccines . Clinicians should expect some vaccine failures with the heptavalent conjugate vaccine in children with advanced HIV disease.

Pediatr Infect Dis J, 2001 Oct, 20(10), 1007 - 9
Group B streptococcal cellulitis in a child with steroid-responsive nephrotic syndrome; Sickler SJ et al.; Although infectious complications of nephrotic syndrome are common, group B Streptococcus is a rare pathogen in these patients . We present a 4-year-old child with nephrotic syndrome who developed group B streptococcal cellulitis and bacteremia, an association not previously discussed in the literature, and review the factors that predispose patients with nephrotic syndrome to infection.

Pathol Biol (Paris), 2001 Sep, 49(7), 583 - 6
{In vitro activity of pristinamycin against Streptococcus pneumoniae}; Maugein J et al.; The activity of the pristinamycin was investigated using disk diffusion agar or ATB PNEUMO system and MIC determination using reference liquid medium method (NCCLS) on 749 S . pneumoniae strains isolated in Aquitaine in 1999 . We have realized the killing curves against 10 isolates selected from erythromycin-susceptible and resistant S . pneumoniae strains . All the strains tested by ATB PNEUMO system were susceptible to pristinamycin, using disk diffusion agar, 6.8% of strains were intermediate or resistant . However the MIC's of pristinamycin determined by liquid dilution method against these strains were < 1 mg/L . These data suggest that the zone of inhibition around the disk was not correlated with MIC for erythromycin pneumococci and MIC testing must be performed . The results of killing curves showed a very good and rapid bactericidal activity of pristinamycin within two hours for concentration equal to 4 x MIC and four hours for 2 x MIC.

Pathol Biol (Paris), 2001 Sep, 49(7), 548 - 52
{Evaluation of the E-test and the ATB-PNEUMo battery for determining the beta-lactam MIC for Streptococcus pneumoniae in daily practice}; Chomarat M et al.; In 1999, during the survey of resistance of Streptococcus pneumoniae to antibiotics by 31 clinical laboratories of Rhone-Alpes area, MIC to penicillin (P), amoxicillin (AMX) and cefotaxime (CTX) of 877 PRP strains or with a diameter of inhibition to oxacillin inferior to 26 mm, were determined by each institution by E-test (n = 220 strains) or ATB-PNEUMO (n = 657 strains) . MICs of these three antibiotics were determined by dilution in agar medium by the coordinating center . The essential agreement was respectively for ATB-PNEUMO and E-test 89% versus 84% for P (p > 0.05), of 86% vs 79% for AMX (p < 0.01), and of 91% vs 86% for CTX (p = 0.03) . When the strains were classified in clinical category, the differences were significant (p < 0.001) for AMX (85% vs 71%) and for CTX (82% vs 75%) but not for P (73% vs 78%) . ATB-PNEUMO method was more sensitive than E-test for the detection of strains susceptible to P (90 vs 73%), to AMX (83 vs 78%) and to CTX (80 vs 72%) and for the strains intermediate to AMX (90 vs 78%) . On the contrary, E-test is more specific than ATB-PNEUMO for the detection of P-resistant strains (94 vs 86%) . Finally, the specificity of both methods is the same for detection of P-S, AMX-R and CTX-I strains.

Pathol Biol (Paris), 2001 Sep, 49(7), 522 - 7
Distribution of macrolide resistance genes erm(B) and mef(A) among 160 penicillin-intermediate clinical isolates of Streptococcus pneumoniae isolated in southern France; Marchandin H et al.; Two prevalent mechanisms of macrolide resistance are currently described in pneumococci: production of rRNA methylase that modify 23S ribosomal RNA resulting in MLSB phenotype, and an active efflux system resulting in M-phenotype . These two mechanisms are mediated by erm(B) and mef(A) genes respectively . Several studies reported a predominance of mef(A) gene in United-States and Canada . In European countries, erm(B) determinant is prevalent and mef(A)-mediated erythromycin resistance was recently reported in about 10% of strains in Belgium and Italy . In order to evaluate implication of mef(A) gene in pneumococci erythromycin resistance, 160 clinical isolates of S . pneumoniae with low-level of penicillin resistance and resistance to macrolides recovered between April 1999 and April 2000 were collected . These isolates were tested for their macrolide susceptibility by disc diffusion method, 155 showed the MLSB phenotype and 5 the M phenotype . Genotypic analysis was performed by erm(B) and mef(A) specific-mediated PCR: erm(B) gene was detected in 154 isolates, mef(A) gene in 5 isolates, and both genes in one strain . The phenotype seems to be well correlated to the genotyping result except for strain harboring both resistance determinants . Molecular typing of isolates harboring mef(A) gene performed by pulsed-field gel electrophoresis (PFGE) after restriction by Smal shows these strains to be epidemiologically unrelated . Our results show the predominance of the erm(B) gene in erythromycin resistant S . pneumoniae isolates . mef(A)-mediated resistance is effective in Southern France (3.7%) but this rate is the lowest published from European countries.

Am J Obstet Gynecol, 2001 Oct, 185(4), 854 - 8
No increase in rates of early-onset neonatal sepsis by non-group B Streptococcus or ampicillin-resistant organisms; Chen KT et al.; OBJECTIVE: We assessed the impact of a risk-based approach to group B Streptococcus (GBS) prophylaxis on the rates of early-onset neonatal sepsis (EONS) . STUDY DESIGN: A retrospective cohort study of neonates born at a tertiary-care hospital from 1990 to 1996 was performed . Cases of EONS were identified among neonates born in a period without GBS prophylaxis (1990-1992) and compared with those born in a period with GBS prophylaxis (1993-1996) . The antibiotic susceptibility data on each organism isolated in the blood culture were obtained . RESULTS: In the period without prophylaxis, 99 cases of EONS were identified among 25,934 neonates for a rate of 3.8 per 1000 births . In the period with prophylaxis, 90 cases of EONS occurred among 34,262 neonates for a rate of 2.6 per 1000 . The rate of GBS-EONS significantly decreased between the 2 periods (from 1.9 to 1.1, P =.01) . There was a trend toward a decrease in the rate of EONS caused by non-GBS gram-positive organisms (from 1.2 to 0.7, P =.06) . There was no significant increase in the rate of EONS caused by gram-negative or ampicillin-resistant organisms . CONCLUSIONS: A risk-based approach to GBS prophylaxis reduced the incidence of GBS-EONS at a tertiary-care hospital . This decrease was not accompanied by an increase in the incidence of EONS by non-GBS or ampicillin-resistant organisms.

Caries Res, 2001 Sep-Oct, 35(5), 344 - 53
Salivary concentrations of urea released from a chewing gum containing urea and how these affect the urea content of gel-stabilized plaques and their pH after exposure to sucrose; Dawes C et al.; The objectives were to: (1) determine the salivary concentrations of urea during 20 min chewing of a sugar-free gum containing 30 mg of urea; (2) measure the degree to which this urea would diffuse into a gel-stabilized plaque; (3) study the effect of the urea on the fall and subsequent rise in pH (Stephan curve) on exposure to 10% sucrose for 1 min; (4) model the measurements 2 and 3 mathematically . In point 1, the salivary urea concentration of the 12 subjects peaked at 47 mmol/l in the first 2 min of gum chewing, falling within 15 min to the unstimulated salivary concentration of 3.4 mmol/l . Recovery of urea from the saliva averaged 81.5% . 'Plaques' of 1% agarose or 67% dead bacteria in agarose accumulated urea from the saliva roughly as expected, whereas those plaques containing 8% live and 59% dead Streptococcus vestibularis showed negligible accumulation . Computer modelling showed this difference to be due to urease of live bacteria breaking down the urea as rapidly as it entered the plaque . Simulation of the effect of gum chewing subsequent to initiation of a Stephan curve in the latter type of plaque showed a rapid rise in pH but then a fall again on return to unstimulated conditions . This fall had not been seen in previous studies, with Streptococcus oralis, nor was it predicted by the computer modelling . Neither experimental simulation nor computer modelling suggested that chewing urea-containing gum before exposure to sucrose would have any effect on a subsequent Stephan curve . Thus chewing gum is only likely to inhibit caries when it is chewed after consumption of fermentable carbohydrate, rather than before.

Semin Clin Neuropsychiatry, 2001 Oct, 6(4), 266 - 76
Obsessive compulsive disorder: is there an association with childhood streptococcal infections and altered immune function?
Murphy TK, Petitto JM, Voeller KK, Goodman WK.
During the last few years, an increased interest in the possibility of immune mediated pathophysiology of obsessive compulsive disorder (OCD) and related disorders has been seen . In the late 1980s, the National Institute of Mental Health reported an increase of obsessive compulsive symptoms in patients with Sydenham chorea (SC) . Subsequently, a precipitating streptococcal infection in children with sudden onset of OCD symptoms but no chorea led to the coining of PANDAS (pediatric autoimmune neuropsychiatric disorders associated with streptococcus).This association has furthered interest in studying immune parameters in non-PANDAS OCD as well . This article will review the neuropsychiatric findings in OCD and Tourette syndrome (TS) with emphasis placed on PANDAS, and its association with SC, and a review of the existing studies that have assessed immunologic measures in patients with OCD and TS .

J Biol Chem, 2001 Dec 21, 276(51), 47966 - 74 Epub 2001 Oct 17.
CpsB is a modulator of capsule-associated tyrosine kinase activity in Streptococcus pneumoniae; Bender MH et al.; Tyrosine phosphorylation is associated with polysaccharide synthesis in a number of Gram-positive and Gram-negative bacteria . In Streptococcus pneumoniae, CpsB, CpsC, and CpsD affect tyrosine phosphorylation and are critical for the production of a mature capsule in vitro . To characterize the interactions between these proteins and the phosphorylation event they modulate, cps2B, cps2C, and cps2D from the capsule type 2 S . pneumoniae D39 were cloned and expressed both individually and in combination in Escherichia coli . Cps2D purified from E . coli was not phosphorylated unless it was co-expressed with its cognate transmembrane domain, Cps2C . Purified phosphorylated Cps2D had tyrosine kinase activity and could phosphorylate both dephosphorylated Cps2D and an exogenous substrate (poly-Glu-Tyr) in the absence of ATP . Cps2B exhibited phosphatase activity against both purified phosphorylated Cps2D and p-nitrophenyl phosphate . An additional role for Cps2B as an inhibitor of Cps2D phosphorylation was demonstrated in both co-expression experiments in E . coli and in vitro experiments where it blocked the transphosphorylation of Cps2D even in the presence of the phosphatase inhibitor sodium orthovanadate . cps2C and cps2D deletion mutants in S . pneumoniae produced no detectable mature capsule during laboratory culture . Both were avirulent in systemic mouse infections and were unable to colonize the nasopharynx, suggesting that the failure to produce capsule was not dependent on the environment . Based on these results, we propose a model for capsule regulation where CpsB, CpsC, CpsD, and ATP form a stable complex that enhances capsule synthesis.

Int Immunopharmacol, 2001 Oct, 1(11), 1957 - 68
Comparison of cytokine-inducing activity in a lipoteichoic acid-related molecule isolated from a penicillin-killed group A Streptococcus and from untreated bacteria; Okamoto M et al.; We previously generated a monoclonal antibody, TS-2, that neutralizes the interferon (IFN)-gamma-inducing activity of OK-432, a penicillin-killed streptococcal preparation {J . Immunother . 13 (1993) 232} . Expression of the TS-2-binding antigen was markedly higher in the cell wall of the penicillin-treated Streptococcus pyogenes (OK-432) than in the untreated bacteria (Su-BBM) . We here isolated the antigens from OK-432 and Su-BBM, designated OK-PSA and Su-PSA, respectively . OK-432 markedly induced IFN-gamma and interleukin (IL)-18 as compared with Su-BBM in human peripheral blood mononuclear cells (PBMC) . Furthermore, all of the Thl-type and Th1-inducing cytokines tested {IFN-gamma, tumor necrosis factor (TNF)-alpha, IL-12 and IL-18} were secreted by OK-PSA-stimulated PBMC far better than by Su-PSA-treated PBMC . In addition, the cytolytic activities of the PBMC were accelerated by the stimulation with OK-432 or OK-PSA far better than by the stimulation with Su-BBM or Su-PSA . These findings strongly suggested that OK-PSA is a highly important molecule of OK-432 and may be a useful immunotherapeutic agent for the patients with malignant diseases as a potent Th inducer . It was also shown that penicillin treatment effectively enhances OK-PSA-induced anti-cancer immunity.

BMC Infect Dis . 2001;1(1):13 . Epub 2001 Sep 07.
Bacteremia in hospitalized patients with human immunodeficiency virus: A prospective, cohort study; Afessa B et al.; BACKGROUND: Bacterial infections complicate the course of patients with human immunodeficiency virus infection . The purpose of this study was to describe the bacterial pathogens causing blood stream infection, identify the risk factors for the development of blood stream infection and determine the impact of blood stream infection on the outcome of patients infected with human immunodeficiency virus . METHODS: The incidence, etiology, risk factors and outcome of bacterial blood stream infection were prospectively determined in 1,225 consecutive hospitalizations of adults with human immunodeficiency virus infection . RESULTS: Blood stream infection occurred in 88 hospitalizations (7%); 73 of 89 infections (82%) were community acquired . The most commonly isolated gram-positive organism was Streptococcus pneumoniae (21); gram-negative, Escherichia coli (14) . Blood stream infection was detected in 8% of African Americans and 22% of Hispanics compared with 2% of whites (P = 0.0013) . Patients with blood stream infection had higher white blood cell counts (median, 6.5 vs . 4.9 x 109/L; P = 0.0002) and mortality (18% vs . 4%; P < 0.0001) than patients without infection . CONCLUSIONS: In patients with human immunodeficiency virus, blood stream infection is associated with an increased mortality rate . Recognition of the incidence, etiology, and risk factors of blood stream infection in patients with human immunodeficiency virus infection could lead to measures that reduce the increased mortality.

Respir Med, 2001 Oct, 95(10), 811 - 6
Chlamydia pneumoniae infection and acute exacerbation of chronic obstructive pulmonary disease (COPD); Karnak D et al.; The objective of the study was to investigate the possible association of Chlamydia pneumoniae (Cpn) in acute exacerbations of chronic obstructive pulmonary disease (COPD) patients . Thirty-eight acutely exacerbated COPD patients and 17 healthy smokers were enrolled in the study, as the study and control groups respectively . Nasopharyngeal swabs and paired serum samples for antibody testing of Cpn (microimmunofluorescence--MIF) were obtained from all subjects . Sputum cultures of COPD patients were also performed . No pathogenic bacteria were isolated from nasopharyngeal swabs in any subject . Serologic evidence of recent Cpn infection was observed in 13 (34%) COPD patients and in one (5%) control subject . The prevalence of Cpn IgG and IgM antibodies representing acute infection were significantly higher in COPD patients than in control subjects (P < 0.05 and P < 0.01 respectively) . Prevalence of IgA antibodies and IgG pre-existing antibodies did not show any difference (P > 0.05) . Microbiologic culture of the sputa yielded potentially pathogenic micro-organisms in 23 of 38 (60%) COPD patients . Alpha-haemolytic streptococcus (35%), Niesseria spp . (31%) and Candida spp . (9.5%) were most prominent micro-organisms in positive cultures . Although a high prevalence of IgG antibodies against Cpn was detected, it was the sole causative agent in only four (10%) patients . We conclude that a remarkable number of COPD patients (34%) are acutely infected with Cpn and it may either be the sole causative agent or frequently a co-agent in acute exacerbations.

Pharmacotherapy, 2001 Oct, 21(10), 1204 - 22
Telithromycin: an oral ketolide for respiratory infections; Bearden DT et al.; The ketolides represent a new subclass of antibiotics among the macrolide-lincosamide-streptogramin group . Telithromycin, the first ketolide to be awarded approvable status for clinical use, demonstrates in vitro activity against community-acquired respiratory pathogens including penicillin- and erythromycin-resistant Streptococcus pneumoniae . An extended half-life permits once-daily oral administration . Telithromycin is a substrate for cytochrome P450 (CYP) 3A4 and also inhibits drugs metabolized by CYP3A4 . A relatively high frequency of mild-to-moderate gastrointestinal adverse effects has been reported . Similar clinical and microbiologic efficacy has been demonstrated with oral dosing in comparative clinical trials for community-acquired pneumonia, acute sinusitis, acute exacerbations of chronic bronchitis, and pharyngitis . Although limited data on penicillin-resistant S . pneumoniae and erythromycin-resistant Streptococcus pyogenes are available from clinical trials, this drug appears promising for respiratory infections caused by these pathogens.

Chin Med J (Engl), 1999 Jul, 112(7), 655 - 8
A surveillance study on penicillin-resistant streptococcus pneumoniae in China; Li J et al.; OBJECTIVES: To find out whether there are also penicillin-resistant streptococcus pneumoniae and the resistant rate in China . METHODS: A surveillance study which is a part of the international surveillance on pneumococci resistance to penicillin and other antimicrobial agents was conducted in Beijing, China . More than 900 pediatric patients with respiratory tract infections aged from six months to three years selected from two pediatric units were enrolled in the study . Perthroat swabs were immediately streaked onto blood agar plates . Isolates were identified as pneumococci by their typical appearance, gram stain, confirmation tests . Antibiotic susceptibility was assessed by the disk diffusion method and minimal inhibition concentration (MIC) determination according to Protocol and National Committee for Clinical Laboratory Standards (NCCLS) . RESULTS: Of the 51 streptococcus pneumoniae isolates, 5 strains had zones of inhibition indicative of penicillin resistance, of which two had penicillin MICs > or = 0.1 mg/L and were considered to be relatively or fully resistant to penicillin . The MICs of two penicillin resistant strains were 2 mg/L and 4 mg/L . Resistant rates to ceftriaxone and cefotaxime were 0% and 10% respectively . For the other ten antimicrobial agents, the resistant rates were as follows: ampicillin 12%, piperacillin 26%, furbenicillin 14%, cefuroxime 6%, erythromycin 54%, clarithromycin 52%, meleumycin 64%, roxithromycin 52%, chloramphenicol 35%, tetracycline 100% . CONCLUSIONS: The study suggested that penicillin resistant streptococcus pneumoniae strains existed in China and were also resistant to ampicillin, piperacillin, furbenicillin and cefuroxime . Moreover, the resistant rates of penicillin resistant streptococcus pneumoniae to macrolides and tetracycline were high.

Zhonghua Yi Xue Za Zhi, 1999 Apr, 79(4), 253 - 6
{Antimicrobial resistance in Streptococcus pneumoniae in Beijing and molecular typing of penicillin-resistant strains}; Wang H et al.; OBJECTIVE: To investigate antimicrobial resistance of Streptococcus pneumoniae in Beijing and molecular epidemiology of penicillin-resistant pneumococci strains . METHODS: The resistance to beta-lactam and non-beta-lactam antibiotics of 244 nasopharyngeal isolates of Streptococcus pneumoniae collected from September to November 1997 in 8 day-care centers in Beijing was studied by Etest and agar dilution method . Serotyping was done by "capsular swelling" technique . BOX-PCR technique was used to detect the DNA of resistant strains . RESULTS: 24.8% (244/985) of the children carried Streptococcus pneumoniae . The agreement between the MICs obtained by Etest and agar dilution for penicillin and ceftriaxone was > 93.7% . By Etest, 3/244 (1.3%) strains were resistant to penicillin(MICs, 3 micrograms/ml) and 32/244(13.1%) strains in termedinte (MICs, 0.094-0.25 microgram/ml) . Penicillin-susceptible strains were also susceptible to the other 4 tested beta-lactams . In penicillin non-susceptible strains, 11.4% (4/35) isolates were resistant to the other beta-lactams . The resistant rates of erythromycin, tetracycline, chloramphenicol and trimethoprim-sulfamethoxazole (TMP-SMZ) were 74.0%, 87.6%, 47.8%, 63.3%, respectively . All of the strains were susceptible to vancomycin and rifampin . 119/244(48.7%) strains isolated were multiresistant to tetracycline, erythromycin and TMP/SMZ . Serotype 6A(33.6%), 19F(16.8%), 23F(15.1%), 15(11.2%), 6B(4.3%) were most common . 57.1% (20/35) penicillin non-susceptible strains were of serotype 23F and had similar or identical multiresistance and BOX patterns . CONCLUSION: In Beijing, the prevalence of penicillin-resistant pneumococci was obviously lower than that of neighboring countries, but resistant rate to non-beta-lactams was high . The epidemic multiresistant 23F clone found in day-care centers was different from the Spanish clone.

Zhonghua Yi Xue Za Zhi, 1999 Jan, 79(1), 38 - 40
{A surveillance study on penicillin-resistant Streptococcus pneumoniae in China}; Li J et al.; OBJECTIVES: To find out if there are penicillin-resistant Streptococcus pneumoniae and the resistance rate in China . METHODS: 989 pediatric patients with respiratory tract infections aged from 6 months to 3 years from two pediatric units were enrolled . Perthroat swabs were immediately streaked onto blood agar plates and incubated overnight . Pneumococci were identified and isolated . Antibiotic susceptibility was assessed by the disk diffusion method and MIC determination according to Protocol and NCCLS . RESULTS: Of the 51 Streptococcus pneumoniae isolates, 5 strains had zones > or = 20 mm . Two of the 5 strains had penicillin MICs > or = 0.1 mg/L (2 and 4 mg/L) and considered to be fully resistant to penicillin(4%) . The resistance rate to ceftriaxone and cefotaxime was 0 and 4% respectively . For the other 10 antimicrobial agents, the resistance rates were as follows: ampicillin 12%, piperacillin 26%, furbenicillin 14%, cefuroxime 6%, erythromycin 54%, clarithromycin 52%, meleumycin 64%, roxithromycin 52%, chloramphenicol 32%, and tetracycline 100% . CONCLUSIONS: The study suggested that penicillin resistant Streptococcus Pneumoniae strains also exist, and the cross-resistance is a significant phenomenon in China.

Antimicrob Agents Chemother, 2001 Nov, 45(11), 3242 - 5
Activities of a new fluoroketolide, HMR 3787, and its (des)-fluor derivative RU 64399 compared to those of telithromycin, erythromycin A, azithromycin, clarithromycin, and clindamycin against macrolide-susceptible or -resistant Streptococcus pneumoniae and S . pyogenes; Nagai K et al.; Activities of HMR 3787 and RU 64399 were compared to those of three macrolides, telithromycin, and clindamycin against 175 Streptococcus pneumoniae isolates and 121 Streptococcus pyogenes isolates . HMR3787 and telithromycin were the most active compounds tested against pneumococci . Telithromycin and RU 64399 were equally active against macrolide-susceptible (MICs, 0.008 to 0.06 microg/ml) and -resistant S . pyogenes isolates, but HMR 3787 had lower MICs for ermB strains.

Antimicrob Agents Chemother, 2001 Nov, 45(11), 3205 - 8
High incidence of erythromycin resistance among clinical isolates of Streptococcus agalactiae in Taiwan; Hsueh PR et al.; The in vitro susceptibilities of 266 isolates of Streptococcus agalactiae determined by the agar dilution method showed that 6% of isolates were nonsusceptible to penicillin and 46% was resistant to erythromycin . Of the erythromycin-resistant isolates, 86.3% had the macrolide-lincosamide-streptogramin (MLS) resistance phenotype (constitutive MLS, 85.5%; inducible MLS, 0.8%) and 13.7% had the M phenotype.

Antimicrob Agents Chemother, 2001 Nov, 45(11), 3140 - 7
Quinolone resistance mutations in Streptococcus pneumoniae GyrA and ParC proteins: mechanistic insights into quinolone action from enzymatic analysis, intracellular levels, and phenotypes of wild-type and mutant proteins; Pan XS et al.; Mutations in DNA gyrase and/or topoisomerase IV genes are frequently encountered in quinolone-resistant mutants of Streptococcus pneumoniae . To investigate the mechanism of their effects at the molecular and cellular levels, we have used an Escherichia coli system to overexpress S . pneumoniae gyrase gyrA and topoisomerase IV parC genes encoding respective Ser81Phe and Ser79Phe mutations, two changes widely associated with quinolone resistance . Nickel chelate chromatography yielded highly purified mutant His-tagged proteins that, in the presence of the corresponding GyrB and ParE subunits, reconstituted gyrase and topoisomerase IV complexes with wild-type specific activities . In enzyme inhibition or DNA cleavage assays, these mutant enzyme complexes were at least 8- to 16-fold less responsive to both sparfloxacin and ciprofloxacin . The ciprofloxacin-resistant (Cip(r)) phenotype was silent in a sparfloxacin-resistant (Spx(r)) S . pneumoniae gyrA (Ser81Phe) strain expressing a demonstrably wild-type topoisomerase IV, whereas Spx(r) was silent in a Cip(r) parC (Ser79Phe) strain . These epistatic effects provide strong support for a model in which quinolones kill S . pneumoniae by acting not as enzyme inhibitors but as cellular poisons, with sparfloxacin killing preferentially through gyrase and ciprofloxacin through topoisomerase IV . By immunoblotting using subunit-specific antisera, intracellular GyrA/GyrB levels were a modest threefold higher than those of ParC/ParE, most likely insufficient to allow selective drug action by counterbalancing the 20- to 40-fold preference for cleavable-complex formation through topoisomerase IV observed in vitro . To reconcile these results, we suggest that drug-dependent differences in the efficiency by which ternary complexes are formed, processed, or repaired in S . pneumoniae may be key factors determining the killing pathway.

Antimicrob Agents Chemother, 2001 Nov, 45(11), 3098 - 103
BMS-284756 in experimental cephalosporin-resistant pneumococcal meningitis; Rodriguez-Cerrato V et al.; BMS-284756 is a novel des-fluoro(6) quinolone with a broad antimicrobial activity, including Streptococcus pneumoniae . The purpose of this study was to evaluate the pharmacodynamic profile and effectiveness of BMS-284756 for therapy of experimental meningitis caused by penicillin- and cephalosporin-resistant S . pneumoniae (CRSP) . Meningitis was induced in rabbits by intracisternal inoculation of CRSP . BMS-284756 was given intravenously 16 h after intracisternal inoculation in single doses of 2.5 (n = 5 animals), 5 (n = 6), 10 (n = 6), 20 (n = 8), and 30 mg/kg (n = 6), in two doses of 10 mg/kg each separated by 5 h (n = 4), and as a 20-mg/kg dose followed 5 h later by 10 mg/kg (n = 5) . The MICs and MBCs of BMS-284756, ceftriaxone, and vancomycin were 0.06 and 0.06, 4 and 4, and 0.25 and 0.25 microg/ml, respectively . After single doses of 10, 20, and 30 mg/kg, the maximum concentrations in cerebrospinal fluid (CSF) (mean +/- standard deviation) were 0.32 +/- 0.12, 0.81 +/- 0.38, and 1.08 +/- 0.43 microg/ml, respectively; the elimination half-life in CSF was 4.5 to 6.3 h . The CSF bacterial killing rates (BKR) at 5 h of the single-dose regimens of 10, 20 and 30 mg/kg were -0.84 +/- 0.48, -1.09 +/- 0.32, and -1.35 +/- 0.05 Deltalog(10) CFU/ml/h . The BKR(0-5) of the divided regimens (10 mg/kg twice and 20 mg/kg followed by 10 mg/kg) was -0.82 +/- 0.52 and -1.24 +/- 0.34 Deltalog(10) CFU/ml/h, respectively . The BKR(0-5) of the combined therapy with vancomycin and ceftriaxone was -1.09 +/- 0.39 Deltalog(10) CFU/ml/h . The penetration of BMS-284756 into purulent CSF relative to plasma was 14 to 25% . The bactericidal effect of BMS-284756 in CSF was concentration dependent . BMS-284756 at 30 mg/kg as a single or divided dose was as effective as standard therapy with vancomycin and ceftriaxone.

J Agric Food Chem, 2001 Oct, 49(10), 5031 - 8
Scavenging of free radicals, antimicrobial, and cytotoxic activities of the Maillard reaction products of beta-lactoglobulin glycated with several sugars; Chevalier F et al.; The Maillard reaction occurs during many industrial and domestic thermal treatments of foods . It is widely used because of its role in creating colors, flavors, textures, and other functional properties in foodstuffs . Proteins glycated without the use of conventional chemical reagents have improved technofunctional properties such as heat stability, emulsifying, and foaming properties . The present study was carried out to determine the extent to which this reaction can convey antioxidant, antimicrobial, or cytotoxic activities to beta-lactoglobulin (BLG) and to its tryptic and peptic hydrolysates . BLG was modified with six different sugars in solution at 60 degrees C . Antiradical properties were estimated using a radical scavenging activity test . Antimicrobial activities against different bacterial strains were studied with a diffusion disk method . Cytotoxic tests were performed using two cell lines and the 3-(4,5-dimethylthiazoyl-2-yl)-2,5-diphenyltetrazolium bromide (MTT) rapid colorimetric assay . Glycation induced a radical scavenging activity to BLG, the intensity of which depended on the sugar used for modification . Proteins modified with ribose and arabinose showed the highest radical scavenging activities depicted by about 80 and 60% of 2,2-diphenyl-1-picrylhydrazyl (DPPH) absorption decrease at 515 nm . No antimicrobial effect of any glycated form of BLG against Escherichia coli, Bacillus subtilis, Listeria innocua, and Streptococcus mutans was observed . The MTT test showed no enhancement of cytotoxicity by modified proteins and peptides against COS-7 and HL-60 cells . Thus, glycated proteins could be used in formulated food as functional ingredients with a radical scavenging activity able to delay deterioration due to oxidation . This use could be even more advisable considering the lack of toxicity to eukaryotic and prokaryotic cell cultures demonstrated in this work.

J Radiat Res (Tokyo), 2001 Jun, 42(2), 191 - 200
OK-432 reduces mortality and bacterial translocation in irradiated and granulocyte-colony stimulating factor (G-CSF)-treated mice; Nose M et al.; Bacterial translocation/Acute radiation syndrome/Endotoxin/G-CSF/OK-432 Acute radiation induces bacterial translocation from the gut, followed by systemic infection and sepsis . In order to reduce the mortality after acute whole body irradiation, it is essential to control bacterial translocation . In this study, we established a bacterial translocation assay as a sensitive method to detect minor mucosal injury by radiation . By utilizing this assay, we evaluated the adverse effects, if any, of hematopoietic reagents on the mucosal integrity in the respiratory and gastro-intestinal tracts . Bacterial translocation to the liver and spleen occurred after whole-body irradiation if the dose exceeded 6 Gy . The administration of G-CSF unexpectedly increased the bacterial translocation in 8 Gy-irradiated mice . The pharmaceutical preparation of low-virulent Streptococcus pyogenes, OK-432, significantly reduced the endotoxin levels in peripheral blood without any reduction of bacterial translocation . A combined treatment with G-CSF and OK-432 decreased bacterial translocation and prevented death . This result indicates that the early administration of G-CSF has an adverse effect on bacterial translocation, and that a combined treatment of G-CSF and OK-432 attenuates the adverse effect of G-CSF and improves the survival rate after acute irradiation.

J Infect Dis, 2001 Nov 1, 184(9), 1206 - 10 Epub 2001 Sep 19.
Multilocus sequence typing of Streptococcus pneumoniae clones with unusual drug resistance patterns: genetic backgrounds and relatedness to other epidemic clones; Sa-Leao R et al.; Six drug-resistant Streptococcus pneumoniae clones were previously identified from day care centers in Portugal, primarily on the basis of common pulsed-field gel electrophoresis (PFGE) patterns . These clones were susceptible to penicillin or had only very low-level resistance to it (most MICs, < or =0.25 microg/mL) and accounted for a large proportion (35%) of all drug-resistant pneumococci colonizing the nasopharynx of healthy children attending day care . Five of the 6 clones were identified among pneumococcal clinical isolates collected in other countries . In this study, we applied multilocus sequence typing (MLST) to describe the genetic background of these clones . MLST confirmed previous findings obtained by PFGE and allowed for the extension of the international clonal relationships by showing that each of the 6 clones was internationally disseminated and was able to cause pneumococcal disease.

J Infect Dis, 2001 Nov 1, 184(9), 1134 - 42 Epub 2001 Sep 20.
Acute ethanol intoxication suppresses lung chemokine production following infection with Streptococcus pneumoniae; Boe DM et al.; Alcohol intoxication impairs neutrophil function and increases host susceptibility to Streptococcus pneumoniae . In a rat model of pneumonia, the effects of acute intoxication were monitored for lung chemokine responses, neutrophil recruitment, and bactericidal activity . Alcohol delayed lung neutrophil recruitment, increased bacterial burden, and decreased survival . Before neutrophil recruitment, bronchoalveolar lavage (BAL) macrophage inflammatory protein-2 (MIP-2) and cytokine-induced neutrophil chemoattractant (CINC) were decreased by alcohol . This alcohol-induced effect was reversed at 6 h, when there were large numbers of neutrophils in control BAL fluid, compared with the alcohol-treated group . Cyclophosphamide-induced neutropenia decreased neutrophil recruitment, minimizing the effects of recruited neutrophils on chemokine levels, and extended the alcohol-induced chemokine suppression . MIP-2 and CINC mRNA contents also were suppressed by alcohol 4 and 6 h after infection . Thus, alcohol suppresses lung chemokine activity in response to S . pneumoniae, which is associated with delayed neutrophil delivery, elevated bacterial burden, and increased mortality.

Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 2001 Oct, 92(4), 451 - 7
Microbiological evaluation of acute periradicular abscesses by DNA-DNA hybridization; Siqueira JF Jr et al.; OBJECTIVE: The purpose of the present investigation was to examine the microbiota of acute periradicular abscesses of endodontic origin by using a molecular genetic method . STUDY DESIGN: Pus was collected by aspiration from 27 cases diagnosed as acute abscesses of endodontic origin, and DNA was extracted to evaluate the occurrence of 49 bacterial species by using whole genomic DNA probes and checkerboard DNA-DNA hybridization . The presence of bacterial DNA in clinical samples was confirmed by polymerase chain reaction with ubiquitous bacterial 16S rRNA gene primers . RESULTS: The results of the checkerboard DNA-DNA hybridization analysis revealed that 37 of the 49 DNA probes tested were reactive with one or more samples . The number of bacterial species in the pus samples ranged from 1 to 33 (mean, 5.9) . Eighteen of the 27 pus samples were positive for at least one DNA probe . The most prevalent species found were: Bacteroides forsythus (29.6% of the cases); Porphyromonas gingivalis (29.6%); Streptococcus constellatus (25.9%), Prevotella intermedia (22.2%), Prevotella nigrescens (22.2%), Fusobacterium periodonticum (18.5%), Fusobacterium nucleatum subspecies nucleatum (18.5%), and Eikenella corrodens (18.5%) . CONCLUSIONS: The microbiologic data of the present investigation indicated that molecular genetic methods could provide additional knowledge regarding the microbiota of acute periradicular abscesses by detecting bacterial species that are difficult--or even impossible--to grow.

Infect Immun, 2001 Nov, 69(11), 7187 - 9
Effect of SpeB and EndoS from Streptococcus pyogenes on human immunoglobulins; Collin M et al.; Streptococcus pyogenes secretes a specific immunoglobulin G (IgG)-protease, SpeB, as well as the IgG glycan-hydrolyzing enzyme EndoS . Here we show that SpeB also degrades IgA, IgM, IgD, and IgE . We also show that EndoS only hydrolyzes the glycan moiety on native but not denatured IgG . Thus, SpeB has a broad immunoglobulin-degrading activity, while EndoS is highly specific for IgG.

Infect Immun, 2001 Nov, 69(11), 7029 - 38
Generation and surface localization of intact M protein in Streptococcus pyogenes are dependent on sagA; Biswas I et al.; The M protein is an important surface-located virulence factor of Streptococcus pyogenes, the group A streptococcus (GAS) . Expression of M protein is primarily controlled by Mga, a transcriptional activator protein . A recent report suggested that the sag locus, which includes nine genes necessary and sufficient for production of streptolysin S, another GAS virulence factor, is also needed for transcription of emm, encoding the M protein (Z . Li, D . D . Sledjeski, B . Kreikemeyer, A . Podbielski, and M . D . Boyle, J . Bacteriol . 181:6019-6027, 1999) . To investigate this in more detail, we constructed an insertion-deletion mutation in sagA, the first gene in the sag locus, in the M6 strain JRS4 . The resulting strain, JRS470, produced no detectable streptolysin S and showed a drastic reduction in cell surface-associated M protein, as measured by cell aggregation and Western blot analysis . However, transcription of the emm gene was unaffected by the sagA mutation . Detailed analysis with monoclonal antibodies and an antipeptide antibody showed that the M protein in the sagA mutant strain was truncated so that it lacks the C-repeat region and the C-terminal domain required for anchoring it to the cell surface . This truncated M protein was largely found, as expected, in the culture supernatant . Lack of surface-located M protein made the sagA mutant strain susceptible to phagocytosis . Thus, although sagA does not affect transcription of the M6 protein gene, it is needed for the surface localization of this important virulence factor.

Infect Immun, 2001 Nov, 69(11), 6987 - 98
A 60-kilodalton immunodominant glycoprotein is essential for cell wall integrity and the maintenance of cell shape in Streptococcus mutans; Chia JS et al.; We have demonstrated previously by Western blotting that in naturally sensitized humans, the serum or salivary antibody response to Streptococcus mutans was directed predominantly to a protein antigen with a size of approximately 60-kDa . To identify this immunodominant antigen, specific serum antibodies were eluted from immunoblots and five positive clones with inserts ranging in length from 3 to 8 kb from identical chromosomal loci were obtained by screening a genomic expression library of Streptococcus mutans GS-5 . Amino acid sequencing established the identity of this immunodominant antigen, a 60-kDa immunodominant glycoprotein (IDG-60), to be a cell wall-associated general stress protein GSP-781, which was originally predicted to have a molecular mass of approximately 45 kDa based on the derived nucleotide sequence . Discrepancy in the molecular mass was also observed in recombinant his-tagged IDG-60 (rIDG-60) expressed from Escherichia coli . Glycosylation, consisting of sialic acid, mannose galactose, and N-acetylgalactosamine, was detected by lectin binding to IDG-60 in cell wall extracts from S . mutans and rIDG-60 expressed in vivo or translated in vitro . Despite the presence of multiple Asn or Ser or Thr glycosylation sites, IDG-60 was resistant to the effect of N-glycosidase F and multiple O-glycosidase molecules but not to beta-galactosidase . Insertional inactivation of the gene encoding IDG-60, sagA, resulted in a retarded growth rate, destabilization of the cell wall, and pleiomorphic cell shape with multifold ingrowth of cell wall . In addition, distinct from the parental GS-5 strain, the isogenic mutant GS-51 was unable to survive the challenge of low pH and high osmotic pressure or high temperature . Expression of the wild-type gene in trans within GS-51 from plasmid pDL277 complemented the growth defect and restored normal cell shape . These results suggested that IDG-60 is essential for maintaining the integrity of the cell wall and the uniformity of cell shape, both of which are indispensable for bacteria survival under stress conditions.

Infect Immun, 2001 Nov, 69(11), 6881 - 6
Effect of deficiency of tumor necrosis factor alpha or both of its receptors on Streptococcus pneumoniae central nervous system infection and peritonitis; Wellmer A et al.; Tumor necrosis factor alpha (TNF-alpha) and TNF-beta are key mediators in bacterial inflammation . We therefore examined the role of TNF-alpha and its two receptors in murine pneumococcal central nervous system infection . TNF-alpha knockout mice and age- and sex-matched controls and TNF receptor (p55 and p75)-deficient mice and heterozygous littermates were infected intracerebrally with a Streptococcus pneumoniae type 3 strain . Mice were monitored until death or were killed 36 h after infection . Bacterial titers in blood, spleen, and brain homogenates were determined . Leukocyte infiltration and neuronal damage were assessed by histological scores . TNF-alpha-deficient mice died earlier than the controls after intracerebral infection although overall survival was similar . TNF-alpha deficiency did not inhibit leukocyte recruitment into the subarachnoid space and did not lead to an increased density of bacteria in brain homogenates . However, it caused a substantial rise of the concentration of S . pneumoniae cells in blood and spleen . Spleen bacterial titers were also increased in p55- and p75-deficient mice . TNF receptor-deficient mice showed decreased meningeal inflammation . Neuronal damage was not affected by either TNF-alpha or TNF receptor deficiency . In a murine model of pneumococcal peritonitis, 10(2) CFU of S . pneumoniae produced fatal peritonitis in TNF-alpha-deficient, but not wild-type, mice . Early leukocyte influx into the peritoneum was impaired in TNF-alpha-deficient mice . The lack of TNF-alpha or its receptors renders mice more susceptible to S . pneumoniae infections.

Infect Immun, 2001 Nov, 69(11), 6731 - 7
Association of mitogen-activated protein kinase pathways with gingival epithelial cell responses to Porphyromonas gingivalis infection; Watanabe K et al.; Mitogen-activated protein (MAP) kinase pathways are key factors in host signaling events and can also play important roles in the internalization of pathogenic bacteria by host cells . Porphyromonas gingivalis, a periodontal pathogen, can efficiently invade human gingival epithelial cells (GECs) . In this study, we examined the activation of MAP kinase pathways in GECs infected with P . gingivalis . c-Jun N-terminal kinase (JNK) was activated after 5 min of infection with P . gingivalis, whereas noninvasive Streptococcus gordonii did not have a significant effect on JNK activation . In contrast, extracellular signal-regulated kinase (ERK) 1/2 was downregulated in a dose-dependent manner by P . gingivalis, but not by S . gordonii, after a 15-min exposure . Nonmetabolically active P . gingivalis cells were unable to modulate MAP kinase activity . U0126, a specific inhibitor of MEK1/2 (ERK1/2 kinase), and toxin B, a specific inhibitor of Rho family GTPases, had no effect on P . gingivalis invasion . Genistein, a tyrosine protein kinase inhibitor, blocked uptake of P . gingivalis . The transcriptional regulator NF-kappaB was not activated by P . gingivalis . These results suggest that P . gingivalis can selectively target components of the MAP kinase pathways . ERK1/2, while not involved in P . gingivalis invasion of GECs, may be downregulated by internalized P . gingivalis . Activation of JNK is associated with the invasive process of P . gingivalis.

Infect Immun, 2001 Nov, 69(11), 6718 - 24
Intranasal vaccination with pneumococcal surface protein A and interleukin-12 augments antibody-mediated opsonization and protective immunity against Streptococcus pneumoniae infection; Arulanandam BP et al.; Streptococcus pneumoniae is a major pathogen in humans that enters the host primarily through the respiratory tract . Targeting mucosal surfaces directly may therefore be an optimal approach for vaccination to prevent bacterial colonization and invasive disease . We have previously demonstrated the effectiveness of interleukin-12 (IL-12) delivered intransally (i.n.) as an antiviral respiratory adjuvant . In this study, we examined the effects of i.n . IL-12 treatment on induction of protective humoral immunity against S . pneumoniae . Immunization i.n . with pneumococcal surface protein A (PspA) and IL-12 resulted in enhanced lung IL-10 mRNA expression and marked augmentation of respiratory and systemic immunoglobulin G1 (IgG1), IgG2a, and IgA antibody levels compared to those in animals receiving PspA alone . In addition, i.n . vaccination with PspA and IL-12 provided increased protection against nasopharyngeal carriage . Flow cytometric analysis revealed a threefold increase in antibody-mediated, complement-independent opsonic activity in the sera of PspA- and IL-12-treated animals, which was mainly contributed by IgG2a and, to a lesser extent, IgA . Passive transfer of these immune sera conferred complete protection from death upon systemic pneumococcal challenge . These findings demonstrate the effectiveness of combining PspA and IL-12 at mucosal sites to achieve optimal antibody-mediated opsonization and killing of S . pneumoniae.

Infect Immun, 2001 Nov, 69(11), 6702 - 6
Immunization with components of two iron uptake ABC transporters protects mice against systemic Streptococcus pneumoniae infection; Brown JS et al.; There has been considerable recent research into protein based Streptococcus pneumoniae vaccines as alternatives to the existing capsular antigen vaccines . PiuA and PiaA (formerly Pit1A and Pit2A) are recently identified lipoprotein components of S . pneumoniae iron uptake ABC transporters which are required for full virulence and are likely to be expressed on the surface of the bacterial cell membrane . We investigated the efficacy of recombinant PiuA and PiaA proteins at eliciting protective immunity in mice against systemic infection with S . pneumoniae . Both recombinant PiuA and PiaA generated antibody responses that cross-reacted with each other but not with pneumolysin and reacted with identical proteins from nine different S . pneumoniae serotypes . Mice immunized with recombinant PiuA and PiaA were protected against systemic challenge to a degree similar to those immunized with an existing protein vaccine candidate, PdB (a genetically modified pneumolysin toxoid) . Immunization with a combination of both PiuA and PiaA resulted in additive protection and was highly protective against systemic infection with S . pneumoniae . PiuA and PiaA are therefore promising additional candidates for a novel S . pneumoniae vaccine using protein antigens.

Infect Immun, 2001 Nov, 69(11), 6633 - 42
Administration of superantigens protects mice from lethal Listeria monocytogenes infection by enhancing cytotoxic T cells; Okamoto S et al.; Superantigens stimulate T-cell-receptor Vbeta-selective T-cell proliferation accompanying the release of cytokines, which may eventually protect the host from microbial infections . We investigated here whether superantigens can rescue the host from lethal bacterial infection . Mice were pretreated with Staphylococcus aureus enterotoxin B (SEB) 1 and 2 days before bacterial infection, and the mortality of infected mice was assessed . SEB pretreatment protected mice from lethal infection with Listeria monocytogenes but not from lethal infection with Streptococcus pyogenes . This enhanced protection was also observed upon pretreatment with recombinant streptococcal pyrogenic exotoxin A . Furthermore, L . monocytogenes-specific delayed-type hypersensitivity (DTH) due to type 1 helper T (Th1) cells and the cytotoxicity of CD8(+) T cells were significantly enhanced after SEB administration and bacterial infection . Depletion of either CD4(+) T cells or CD8(+) T cells in SEB-pretreated mice completely abolished this protection . This phenomenon was ascribed to the elimination of L . monocytogenes-specific CD8(+) cytotoxic T lymphocytes (CTL) . It was found that CD4(+) T cells contributed to the induction of the CTL populations . Furthermore, SEB pretreatment of heat-killed L . monocytogenes-immunized mice enhanced the protection from challenge of L . monocytogenes . Taken together, these results indicated that administrations of superantigens protected mice from infection with L . monocytogenes, which was dependent on the enhanced L . monocytogenes-specific CTL activity in the presence of CD4(+) T cells, and superantigens exhibited adjuvant activity in the immunization against intracellular pathogens.

J Dent Res, 2001 Jul, 80(7), 1672 - 7
Contributions of three glycosyltransferases to sucrose-dependent adherence of Streptococcus mutans; Ooshima T et al.; Streptococcus mutans produces 3 types of glucosyltransferase (GTF), whose cooperative action is considered to be essential for its cellular adherence to the tooth surface . However, the precise mechanisms for synthesizing adhesive glucans and the specific roles of each GTF in cellular adherence to smooth surfaces have not been elucidated . In the present study, seven types of isogenic mutants of S . mutans MT8148 lacking GTFB, GTFC, and/or GTFD activities were constructed by inactivation of the genes encoding GTFB, GTFC, and/or GTFD . Furthermore, recombinant GTFB, GTFC, and GTFD were prepared from Escherichia coli cells harboring recombinant plasmids containing each of the gtf genes . Using these GTF-deficient mutants and rGTFs, we reconstituted sucrose-dependent adherence of S . mutans resting cells and examined the role of each GTF in vitro . The highest level of sucrose-dependent adherence was found at the ratio of 20 rGTFB:1 rGTFC:4 rGTFD in both the resting cells of GTF-deficient mutants and insoluble glucan synthesized by rGTFs . Moreover, when rGTFC and rGTFD were both present at concentrations of 1.5 mU and 6 mU, respectively, the insoluble glucan synthesized from sucrose by the rGTFs showed a high level of adhesiveness to smooth surfaces, even without rGTFB . These results suggest that the presence of all three GTFs at the optimum ratio is necessary for sucrose-dependent adherence of S . mutans, and that GTFC and GTFD may play significant roles in the synthesis of adhesive and insoluble glucan from sucrose.

Rev Argent Microbiol, 2001 Jul-Sep, 33(3), 149 - 54
{Streptococcus pneumoniae: evolution of antibiotic resistance in a pediatric hospital in Córdoba, Argentina}; Culasso C et al.; The wide variety of prevalence of antimicrobial resistant Streptococcus pneumoniae in different countries confirms the importance of determining local patterns of resistance . From 1992 to 2000, we studied the pattern of antimicrobial resistance in S . pneumoniae and its evolution along the years, using 468 strains isolated in the Hospital de Ninos de Cordoba . A total of 177 isolates (37.8%) were not susceptible to penicillin, with 19% intermediate and 18.8% resistant strains . High and intermediate resistance levels to cefotaxime were 4.9% and 10.9%, respectively . Decreased susceptibility to trimethoprim/sulfamethoxazole (TMS), erythromycin, chloramphenicol, and rifampin was found in 194 isolates (41.5%), 32 (6.8%), 13 (2.8%) and 3 (0.6%), respectively . No isolates resistant to vancomycin were detected . The most commonly combined resistance patterns were: penicillin/TMS (35.6%) and penicillin/TMS/cefotaxime (11.8%) . This study highlights the increased rate of drug resistant S . pneumoniae during the last years, and the importance of antimicrobial resistance surveillance of adequate empirical therapy involving local and regional susceptibility patterns.

J Am Soc Echocardiogr, 2001 Oct, 14(10), 1042 - 3
Eustachian valve endocarditis caused by Streptococcus viridans; Schmidt MA et al.; A 76-year-old man was admitted for ethanol detoxification . He was found to be in atrial fibrillation with a rapid ventricular response that was refractory to electrical and chemical cardioversion attempts . The patient subsequently developed respiratory distress . A transesophageal echocardiogram revealed a vegetation attached to the eustachian valve and blood cultures grew Streptococcus viridans . After treatment with appropriate antibiotics, the patient converted to sinus rhythm with sotalol hydrochloride, and the eustachian valve vegetation resolved . This is the first reported case of eustachian valve endocarditis caused by S viridans.

Dis Aquat Organ, 2001 Aug 22, 46(1), 15 - 21
Streptococcus iniae inhibition of apoptosis of nonspecific cytotoxic cells: a mechanism of activation of innate immunity in teleosts; Taylor SL et al.; Nonspecific cytotoxic cells (NCC) may provide innate anti-bacterial resistance against Streptococcus iniae infections in tilapia . The mechanism of immunity would be elaboration and release of various cytokines, augmentation of inflammation and amplification of increased antigen processing . To investigate bacterial regulation of NCC function, 2 different processes of cellular pathology were examined: apoptosis and necrosis . Different isolates of S . iniae from diseased teleosts, a dolphin and a human were tested . All isolates were examined for their ability to produce apoptosis and/or necrosis on freshly purified tilapia NCC and on a tilapia continuous cell line (i.e . TMB-8 cells) . Two different isolates (9033 and 173) inhibited the outer membrane expression of phosphatidylserine (PS) by NCC, an early sign of apoptosis . This occurred at 4 h post-treatment and lasted throughout the 24 h treatment period . All other isolates either did not differ from control levels or produced a small increase in PS expression by NCC . The early reduction in PS expression occurred concomitantly with increased necrosis associated with nonspecific DNA fragmentation . Two-color flow cytometry (Annexin-V vs propidium iodide staining) demonstrated the specificity of Annexin-V binding . Experiments were also done to determine the effects of S . iniae on TMB-8 cells . Treated TMB-8 cells did not produce appreciable Annexin-V binding . Compared to the ATCC strain, 9033 produced high levels of necrosis-associated DNA fragmentation of TMB-8 cells at 4 and 8 h post-treatment . These data indicated that different isolates of S . iniae may regulate NCC anti-bacterial resistance by causing reduced levels of programmed cell death (PCD), increased necrosis and associated enhancement of inflammatory responses . Understanding the relevance of these bacterial effects on NCC may be an important consideration in the evaluation of isolates used in vaccine/ bacterin production.

J Antibiot (Tokyo), 2001 Aug, 54(8), 664 - 78
Synthesis and antibacterial activity of the tricyclic ketolides TE-802 and its analogs; Kashimura M et al.; The novel 6-O-methyl tricyclic ketolides TE-802 and its analogs were synthesized by two successive cyclization reactions, 11,12-cyclic carbamate formation by intramolecular Michael addition and 9,11-diazaheptene ring construction by intramolecular dehydration reaction . These new tricyclic ketolides exhibited good in vitro antibacterial activity against not only erythromycin-susceptible strains but also erythromycin-resistant Staphylococcus aureus and Streptococcus pneumoniae, which are problematic pathogens of nosocomial and community-acquired respiratory tract infections, respectively.

J Immunol, 2001 Oct 15, 167(8), 4543 - 52
Quantifying the relationship between multiple immunological parameters and host resistance: probing the limits of reductionism; Keil D et al.; Although reductionist experimental designs are excellent for identifying cells, molecules, or functions involved in resistance to particular microbes or cancer cells, they do not provide an integrated, quantitative view of immune function . In the present study, mice were treated with either dexamethasone (DEX) or cyclosporin A (CyA), and immune function and host resistance were evaluated . Multivariate statistical methods were used to describe the relative importance of a broad range of immunological parameters for host resistance in mice treated with various dosages of DEX . Multiple regression and logistic regression analysis indicated that changes in 24 immunological parameters explained a substantial portion of the changes in resistance to B16F10 tumor cells or streptococcus group B . However, at least 40% of the change in host resistance remained unexplained . DEX at all dosages substantially suppressed numerous relevant immunological parameters, but significantly decreased resistance to Listeria monocytogenes only at the highest dosage . In contrast, CyA substantially decreased resistance to L . monocytogenes at dosages that caused relatively minor suppression of just a few immunological parameters (unfortunately, CyA data and host resistance data for L . monocytogenes were not suitable for multivariate analysis) . These results illustrate that mathematical models can be used to explain changes in host resistance on the basis of changes in immune parameters, and that moderate changes in relevant immunological parameters may not produce the types of changes in host resistance expected on the basis of results from reductionist experimental designs.

J Bacteriol, 2001 Nov, 183(21), 6324 - 34
Regulation of D-alanyl-lipoteichoic acid biosynthesis in Streptococcus agalactiae involves a novel two-component regulatory system; Poyart C et al.; The dlt operon of gram-positive bacteria comprises four genes (dltA, dltB, dltC, and dltD) that catalyze the incorporation of D-alanine residues into the lipoteichoic acids (LTAs) . In this work, we characterized the dlt operon of Streptococcus agalactiae, which, in addition to the dltA to dltD genes, included two regulatory genes, designated dltR and dltS, located upstream of dltA . The dltR gene encodes a 224-amino-acid putative response regulator belonging to the OmpR family of regulatory proteins . The dltS gene codes for a 395-amino-acid putative histidine kinase thought to be involved in the sensing of environmental signals . The dlt operon of S . agalactiae is mainly transcribed from the P(dltR) promoter, which directs synthesis of a 6.5-kb transcript encompassing dltR, dltS, dltA, dltB, dltC, and dltD, and from a weaker promoter, P(dltA), which is located in the 3' extremity of dltS . We demonstrate that P(dltR), but not P(dlA), is activated by DltR in the presence of DltS in D-Ala-deficient LTA mutants resulting from insertional inactivation of the dltA gene, which encodes the cytoplasmic D-alanine-D-alanyl carrier ligase DltA . Expression of the dlt operon does not require DltR and DltS, since the basal activity of P(dltR) is high, being 20-fold that of the constitutive promoter P(aphA-3) which directs synthesis of the kanamycin resistance gene aphA-3 in various gram-positive bacteria . We hypothesize that the role of DltR and DltS in the control of expression of the dlt operon is to maintain the level of D-Ala esters in LTAs at a constant and appropriate value whatever the environmental conditions . The DltA(-) mutant displayed the ability to form clumps in standing culture and exhibited an increased susceptibility to the cationic antimicrobial polypeptide colistin.

Plasmid, 2001 Sep, 46(2), 77 - 85
Complete nucleotide sequence and characterization of pUA140, a cryptic plasmid from Streptococcus mutans; Zou X et al.; Approximately 5% of strains of Streptococcus mutans contain plasmid DNA . Strain UA140 harbors a 5.6-kb cryptic plasmid, pUA140, with an overall G+C content of 32.7% . Five open reading frames (ORF), encoding peptides of larger than 100 amino acid residues, were initially designated as ORF1 to ORF5 . These five ORFs were located on the same strand of pUA140 . ORF1 (258 amino acids) resembled a replication protein, Rep . Upstream of the putative Rep gene, a double-stranded origin for plasmid replication that showed strong similarity to those of a number of plasmids in the pT181 family was identified . Further upstream was a region constituting the single-stranded origin of replication . A single-stranded DNA intermediate was detected during plasmid replication . Taken together, these results suggest that pUA140 replicated by the rolling circle replication mechanism but exhibited several characteristics that differ from those of other members of the pT181 plasmid family .

J Chemother, 2001 Aug, 13(4), 413 - 23
An observational study on the epidemiology of respiratory tract bacterial pathogens and their susceptibility to four injectable beta-lactam antibiotics: piperacillin, piperacillin/tazobactam, ceftazidime and ceftriaxone; Varotto F et al.; Bacterial infections of the respiratory tract account for a large proportion of total medical consultations in general practice . In recent years, antibiotic resistance has increased alarmingly in a number of bacterial species that are common causes of these infections . The aim of this observational study was to determine the antibiotic resistance of microbial agents isolated from patients with acute or acutely exacerbated respiratory infections . Subjects recruited as potential sources of bacteria were either outpatients seen in a number of specialized clinics and hospital practices, or hospitalized patients . Overall, 648 consecutive patients (67% male, mean age 48.1+/-27.0 years) with infection of the upper or lower respiratory tract were observed during a 13-month period . A total of 551 pathogenic microbial strains were isolated and tested for their in vitro susceptibility to piperacillin, piperacillin/tazobactam, ceftazidime, and ceftriaxone . Among all isolates, the four most frequent pathogens were Pseudomonas aeruginosa (132 isolates, 24%), Streptococcus pyogenes (99 isolates, 18%), Staphylococcus aureus (93 isolates, 17%), and Klebsiella pneumoniae (46 isolates, 8%) . The susceptibility of gram-positive isolates ranged from 97.5% to 95.1%, and no remarkable difference was found in the antibacterial activity of tested b-lactam antibiotics . The susceptibility of gram-negative isolates to piperacillin and piperacillin/tazobactam was also similar: 96.5% and 97.1%, respectively . In contrast, differences were found between piperacillin (or piperacillin/tazobactam) and either ceftazidime (p=0.003) or ceftriaxone (p<0.0003) in gram-negative isolates . We conclude that, despite the extensive use of beta-lactam antibiotics (piperacillin, ceftazidime, and ceftriaxone) in medical practice during the past three decades, the susceptibility of the most common pathogens involved in the etiology of upper and lower respiratory tract infections to these antibiotics is still high . In particular, bacterial resistance developed by gram-positive organisms against piperacillin is negligible and not alarming.

Clin Infect Dis, 2001 Nov 1, 33(9), 1489 - 94 Epub 2001 Oct 04.
Pneumococcal conjugate vaccine serotypes of Streptococcus pneumoniae isolates and the antimicrobial susceptibility of such isolates in children with otitis media; Joloba ML et al.; The ability of the recently licensed 7-valent pneumococcal conjugate vaccine to cover isolates that cause otitis media, especially drug-resistant ones, was assessed using 500 recently obtained US isolates . Of these isolates, 418 (84%) belonged to vaccine-related serogroups, whereas 82 (16%) belonged to non-vaccine-related serogroups . Serotype 3 accounted for 48 (59%) of the non-vaccine-related serogroups . In addition, 93% of the isolates from patients < or =3 years of age belonged to serotypes that were included in or related to the heptavalent vaccine, compared with 49% of the isolates from older patients (P=.001) . Most of the isolates (98%-100%) that were resistant to the antimicrobial agents tested were covered by the heptavalent vaccine, including 95.1% of the isolates from patients <2 years of age . The 7-valent pneumococcal conjugate vaccine could therefore potentially provide protection against all but 1 (type 3) of the common otitis media-associated pneumococcal serogroups identified in this study as well as against 98% of antibiotic-resistant isolates.

Chemotherapy, 2001, 47 Suppl 4, 19 - 25; discussion 26-7
Optimal treatment strategies for community-acquired pneumonia: high-risk patients (geriatric and with comorbidity); Carbon C; The four major factors predisposing individuals to community-acquired pneumonia (CAP) are chronic obstructive pulmonary disease, congestive heart failure, diabetes, and a high alcohol intake . The elderly are also at increased risk of severe infection . The introduction of fluoroquinolones with increased activity against Streptococcus pneumoniae and other CAP pathogens has been an important development, with recent guidelines recommending the use of respiratory fluoroquinolones as a first-line choice in outpatients with modifying factors, nursing home residents, and hospitalised patients in medical wards . Of the fluoroquinolones currently available that have antipneumococcal activity, levofloxacin is well tolerated and effective . It has been approved by the Food and Drug Administration (FDA) for treatment of CAP and widespread use has shown it to be very safe .

Acta Otolaryngol, 2001 Jul, 121(5), 637 - 42
Remarkable attachment of lactoferrin to Streptococcus pyogenes during acute pharyngotonsillitis; Stenfors LE et al.; The purpose of this study was to establish whether lactoferrin (hLf) attached to Streptococcus pyogenes, one causative agent of acute pharyngotonsillitis (AT), during the course of the disease . Bacterial samples were obtained from the tonsillar surfaces of 7 patients (6 females, 1 male; median age 26 years; range 16-50 years) suffering from AT who were culture-positive for S . pyogenes and from 5 healthy adult controls who were culture-negative for this pathogen . Using gold-labelled antiserum against S . pyogenes and hLf, this pathogen and other bacteria on the tonsillar surfaces coated with hLf could be identified by tracing the gold particles in a transmission electron microscope . In healthy adults, 8% (median value; range 6-12%) of the surface tonsillar bacteria were coated with hLf . In AT patients, 59% (median value; range 42 67%) of S . pyogenes were coated with hLf, in contrast to 9% (median value; range 0-26%) of all other bacteria (p < 0.01) . This study hints that hLf might participate in recovery from AT in several ways, e.g . by binding to the S . pyogenes pathogens, in addition to its well-known virtue of iron-binding capacity.

Arch Pediatr, 2001 Sep, 8 Suppl 4, 762s - 768s
{Clinical aspects of streptococcal and staphylococcal toxinic diseases}; Floret D; Staphylococcus aureus and Streptococcus pyogenes produce a lot of toxins, some of them responsible for specific diseases . Staphylococcal food poisoning is due to ingestion of enterotoxin containing food . Seven toxins have been isolated so far . Generalized exfoliative syndrome is related to exfoliatin . Young children are particularly affected . The disease consists in a cutaneous exfoliation usually limited with a favourable outcome . The mucus membranes are not involved . The nose or pharynx are the most usual portal of entry . Staphylococcus aureus is not grown from the bullae . Severe extensive forms have been observed particularly in neonates (Ritter's disease) . Bullous impetigo is also due to exfoliatin . It consists in the presence of a restricted number of cloudy bullae, from which staphylococcus can be grown . It is a mild disease with a favourable outcome within a few days . Scarlet fever is related to the streptococcal erythrogenic toxins . The classic form of the disease is presently rare . This disease may be related to staphylococcus as a complication of arthritis, osteomyelitis or wound super-infection . Bacteremia is usual . Staphylococcal scarlet fever is not related to exfoliatin as previously believed, but to enterotoxins or TSST-1, so it seems to be an abortive form of toxic shock syndrome . Toxic shock syndrome is defined as a multi organ failure syndrome with a rapid onset, fever, rash followed by desquamation, vomiting and diarrhea, hypotension, conjunctivitis and strawberry tongue . The disease is related to an infection or colonisation with a toxin (TSST-1) producing strain of Staphylococcus aureus . Enterotoxins (mainly C) may be involved . The disease may occur in childhood, sometimes after superinfection of varicella . The mortality is low (5%) and mainly due to ARDS or cardiac problems . Erythrogenic toxins produced by Streptococcus pyogenes are involved in a streptococcal form of toxic shock syndrome with a quite similar presentation . In most cases however, a cutaneous or soft tissue infection is at the origin . Necrotizing fasciitis complicating varicella is a classic cause in children . Bacteremia is often observed . The mortality rate is as high as 60% . The streptococcal strains involved in north america use to produce the toxin erythrogenic A, the european cases seem to be more related to strains secreting the B toxin with a dysregulation of the mechanisms which control the secretion of the toxin . Staphylococcus strains producing the Panton and Valentine leucocidin are responsible for chronic or relapsing furonculosis and above all for a very severe necrotizing pneumonia observed in children and young adults presenting as an acute respiratory distress syndrome with leucopenia, hemoptysis and shock carrying a heavy mortality rate . Besides these specific diseases, staphylococcal and streptococcal toxins may be involved in some syndromes of unknown origin, in which the intervention of superantigens seems very likely . Kawasaki syndrome is among them as strains producing staphylococcal and streptococcal toxins have been grown from patients with Kawasaki syndrome . In the same way, the intervention of toxins is suspected in the determination of sudden infant death syndrome and atopic eczema.

Arch Pediatr, 2001 Sep, 8 Suppl 4, 757s - 761s
{Severe Streptococcus pyogenes cutaneous infections}; Olivier C; Streptococcus pyogenes is the first bacteria encountered in severe cutaneous infections in children . They enclose erysipela (papillar derma concerned more than hypoderma, lymphatic involvement) and necrotising fasciitis NF (focus on fascia and muscles with extension to hypoderma and reticular derma; venous thrombosis; hypodermic and aponevrotic necrosis) . A skin lesion is the entrance of infection: varicella lesions are a major factor of NF . In France, sporadic cases in children are observed . The annual incidence of S . pyogenes invasive diseases is 1/100,000 children under 5 years of age and 0.6/100,000 children under 15 years of age . In North America, resurgence has been notified during the past ten years with mortality and morbidity due to NF and toxic shock syndromes . Interaction between bacteria and host, natural reservoir, explains the physiopathology . During the past ten years, some serotypes have become more invasive and virulent . Any cutaneous lesion interrupt the dermal barrier . Bacterial wall, proteins M and adhesins permit colonisation . Four pyrogenic exotoxins are superantigens; some facilitate inflammation, tissular lesions and shock; other participate to bacterial extension . In young children, immune response is immature . Albeit causal link between non-steroids anti-inflammatory drugs and NF in varicella children was not clearly demonstrated, caution should be kept in mind . Diagnosis of erysipela is clinical: sudden appearance of an inflammatory zone, most often on legs, with high fever and pain; sometime peripheral surelevation, lymphangitis, adenopathia . Other aspects open discussion with NF . In NF are in favour, added to high fever, huge pain, erythema and oedema: rapid extension of lesions, cutaneous hypoesthesia appearance, gap between intense severe general status (toxic shock syndrome) and paucity of local signs . NF is a medico-surgical emergency . Early surgery with complete excision of necrotic tissues permit survival . Magnetic resonance is useful in subacute NF . Microbiological diagnosis is possible in 20 to 80% of cases, using combined methods . Blood cultures identify the bacteria in 5 to 20%, skin lesion samples in 30% . Local samples are less useful even with modern techniques . Therapeutic strategy depends on initial diagnosis . Intra-venous antibiotics are necessary: penicillin (G, A or M) is first line therapy . In erysipela, ten days allow a rapid cure without sequellae . In NF, antibiotics are associated with intensive care and surgery . A late diagnosis, a too late surgery explain 16 to 36% of deaths encountered.

Arch Pediatr, 2001 Sep, 8 Suppl 4, 747s - 751s
{Mortality due to Streptococcus pneumoniae infection in children . A 5-year retrospective study in Ile-de-France}; Ovetchkine P et al.; Streptococcus pneumoniae is the leading cause of community acquired infections . We conducted a 5 years retrospective study to assessed mortality of pneumococcal infections in children in the area of Paris . Regarding the provided answers, the mortality rate is 0.3/100.000/year in the 0-15 years old children . The majority of them are toddlers . Only 30% of cases occurred in high-risk children . Meningitis was the main cause of death . Pneumococcal resistance to antibiotics did not appear as a risk factor of mortality.

Klin Padiatr, 2001 Sep-Oct, 213(5), 299 - 300
{Dentogenic infection due to Streptococcus constellatus in a child}; Handrick W et al.; An 8-year-old boy was admitted with a pain-full swelling at the right mandible and symptoms of septicemia . The illness was caused by a dental infection due to Streptococcus constellatus proved by isolation from blood culture, the origin was a decayed tooth . Treatment comprised suitable antibiotics, extraction of the tooth and local irrigations with chlorhexidine solution . General condition improved rapidly, the local situation rather slowly, however.

Pediatrics, 2001 Oct, 108(4), 856 - 65
High rates of multiple antibiotic resistance in Streptococcus pneumoniae from healthy children living in isolated rural communities: association with cephalosporin use and intrafamilial transmission; Samore MH et al.; OBJECTIVE: Streptococcus pneumoniae is one of the most clinically significant pathogens with emerging antibiotic resistance . We performed a surveillance study in isolated rural populations of healthy children to estimate the prevalence of pneumococcal resistance and to contrast factors that predict pneumococcal carriage with those that specifically predict resistant pneumococcal carriage . METHODS: The study was conducted in 1998 in 2 rural communities in Utah . Families were recruited directly for participation through community canvassing . Surveillance nasopharyngeal cultures were obtained from children who were younger than 8 years . Antibiotic usage and information on other potential risk factors were obtained from questionnaires and local pharmacy records . Resistance was determined by testing isolates for susceptibility to penicillin, cefaclor, trimethoprim-sulfamethoxazole, erythromycin, ceftriaxone, and trovafloxacin . Selected resistant isolates were characterized further by serotyping, pulsed field gel electrophoresis, and Southern blot with DNA probes specific for the pneumococcal lytA gene and for antibiotic resistance genes . RESULTS: In April 1998, surveillance nasopharyngeal cultures were obtained from 368 children aged </=8 years in community A and 369 children in community B . The number of antibiotic courses per child within 1 year before culture was higher in community B than A (mean: 2.2 vs 1.7) . Conversely, oral cephalosporins were more frequently used in community A than B (community A: 22% received cephalosporins within 4 months; community B: 12%) . Colonization with S pneumoniae was detected in 24% of children in community A and 14% in community B; 36% of isolates from community A and 28% of isolates from community B were resistant or intermediately susceptible to at least 1 antibiotic tested . Reduced susceptibility was most common to trimethoprim-sulfamethoxazole and cefaclor (28% and 26%, respectively) . Pneumococcal carriage (susceptible or resistant) was independently associated with age <5 years (odds ratio {OR}: 2.2), child care exposure (OR: 2.4), presence of a sibling with a positive culture (OR: 3.3), and residence in community A (OR: 1.7) . Among carriers, age <2 years (OR: 2.6), use of cephalosporins within the preceding 4 months (OR: 2.7), and having a sibling colonized with resistant S pneumoniae (OR: 5.5) were independent predictors of reduced susceptibility or resistance . Each pair of resistant isolates from siblings was indistinguishable by pulsed field gel electrophoresis and other molecular typing techniques . Several pneumococcal isolates from these isolated rural areas had the molecular characteristics of international clones of multiple-drug-resistant pneumococci that have been associated with worldwide spread . CONCLUSIONS: Young age and intrafamilial transmission were important risk factors for carriage of both susceptible and resistant S pneumoniae . In contrast, previous cephalosporin use was linked specifically to resistant pneumococcal carriage, which suggests that modifications in antibiotic usage patterns may have salutary effects on antimicrobial resistance . These results extend previous observations in large cities regarding the penetration of multiple-drug-resistant clones of pneumococci into community populations.

J Antimicrob Chemother, 2001 Oct, 48(4), 541 - 4
Detection of macrolide resistance mechanisms in Streptococcus pneumoniae and Streptococcus pyogenes using a multiplex rapid cycle PCR with microwell-format probe hybridization; Farrell DJ et al.; In this study, a multiplex rapid cycle PCR with microwell-format probe hybridization method was developed to perform high-volume screening for macrolide resistance determinants in isolates of Streptococcus pneumoniae and Streptococcus pyogenes . The method was then utilized to determine the distribution of macrolide resistance mechanisms in recent isolates of S . pneumoniae and S . pyogenes from Great Britain and Ireland . For 83 strains of macrolide resistant S . pneumoniae tested, 51 (61.4%) were positive for mef(A), 29 (34.9%) erm(B), two (2.4%) double mechanisms mef(A) + erm(B), and one (1.2%) negative for all mechanisms tested . For 56 strains of macrolide-resistant S . pyogenes tested, 33 (58.9%) were positive for erm(A) subclass erm(TR), 18 (32.1%) mef(A) and five (8.9%) erm(B).

Mol Microbiol, 2001 Sep, 41(6), 1327 - 38
The promoter of the operon encoding the F0F1 ATPase of Streptococcus pneumoniae is inducible by pH; Martin-Galiano AJ et al.; The genes encoding the subunits of the F0F1 membrane ATPase of Streptococcus pneumoniae were cloned and sequenced . The eight genes, transcribed to one mRNA, are organized in an operon encoding the c, a, b, delta, alpha, gamma, beta and epsilon subunits of 66, 238, 165, 178, 501, 292, 471 and 139 amino acid residues, respectively, that were expressed in an Escherichia coli system . To investigate the role of the ATPase in the regulation of the intracellular pH, the expression of the operon between pH 5.7 and 7.5 was studied . An increase in both the ATPase activity and the amount of the alpha and beta F1 subunits as shown by Western blot analysis was observed as the pH decreased . These increases were accompanied by an increase in the atp-specific mRNA, as shown by Northern blot and slot-blot analysis . Primer extension experiments and transcriptional fusions between the atp promoter and the reporter cat gene demonstrated that this pH-dependent increase in the mRNA was regulated at the level of initiation of transcription . Transcription of the operon occurs from a promoter with a consensus -35 box (TTGACA) and a -10 box (TACACT) that differs from the consensus (TATAAT) . A point mutation at the -10 box of the promoter (change to TGCACT) avoided this increase, suggesting a role for this sequence in the pH-inducible regulation.

Intern Med, 2001 Sep, 40(9), 873 - 7
Efficacy of transthoracic needle aspiration in community-acquired pneumonia; Ishida T et al.; OBJECTIVE: To evaluate the indications, efficacy, and safety of transthoracic needle aspiration (TNA) in diagnosing community-acquired pneumonia (CAP) . METHODS: TNA procedure was performed using an ultrathin needle with ultrasonography and/or computed tomography . The aspirate samples were Gram-stained and sent for cultures . The results were compared with those from conventional microbiological studies . PATIENTS: Sixty patients with CAP who were admitted to the hospital and were studied prospectively between July 1994 and June 1999 were included in the study . RESULTS: TNA culture was positive in 30 cases (50.0%) . Streptococcus pneumoniae was the most frequently isolated pathogen, followed by the Streptococcus milleri group, and anaerobes . The results of TNA were consistent with those of quantitative sputum cultures in 9 patients and with those of blood cultures in 4 . Complications arose in 3 patients who developed small to moderate pneumothorax . CONCLUSIONS: TNA is a safe procedure with a good diagnostic yield . In particular, anaerobes or microaerophils such as the S . milleri group were highly detectable by TNA . The results obtained by TNA were highly consistent with those obtained by the gold standard methods . Combined with conventional methods, TNA is considered highly useful for determining the etiology of CAP.

Clin Exp Rheumatol, 2001 Sep-Oct, 19(5), 587 - 8
A definite case of spondylodiscitis caused by Streptococcus equisimilis; Richette P et al.; To shed light on the role of Streptococcus equisimilis (SE) in the pathogenesis of intervertebral disc infection, we report here a case of lumbar spondylodiscitis in a 37-year-old male caused by SE, with identification of this strain by cultures from L4-L5 lumbar disc biopsy . Intravenous therapy with penicillin and gentamycin combined with immobilization resulted in a rapid and complete recovery . The patient did not have underlying disease and showed no obvious history of exposure to animals . We conclude that SE may be responsible for both septic arthritis and spondylodiscitis.

Nippon Shokakibyo Gakkai Zasshi, 2001 Sep, 98(9), 1060 - 4
{Clinical features in six patients with liver abscess caused by Streptococcus milleri}; Tomiyama R et al.; Among 39 patients with pyogenic liver abscess who were admitted to our institute, six (15%) were infected by Streptococcus milleri (S . milleri) . We investigated clinical features of these six patients . There were five males and one female, aged 43-81 years old (mean: 61) . Five of the six patients had underlying illness . All patients had fever, and three of them complained of abdominal pain . Three patients had mixed infections; particularly intraoral anaerobes, Fusobacterium, were found in two of the three patients . There were no differences in clinical features between patients with S . milleri liver abscess and those with other bacterial liver abscess . In conclusion, on selecting antibiotics for the treatment of liver abscess, it is necessary to consider the S . milleri and intraoral anaerobes.

An Esp Pediatr, 2001 Oct, 55(4), 315 - 20
{Pneumococcal meningitis: epidemiological, clinical and bacteriological characteristics}; Soult Rubio JA et al.; OBJECTIVE: To analyze the epidemiological and clinical features of pneumococcal meningitis . PATIENTS AND METHODS: We performed a retrospective study of 53 cases of pneumococcal meningitis that occurred in 47 pediatric patients in our hospital between 1977 and 2000 . Four children had recurrent meningitis . In all patients Streptococcus pneumoniae was isolated from cerebrospinal fluid culture . The epidemiological, bacteriological and clinical characteristics were studied . RESULTS: Pneumococcal meningitis represented 6 % of bacterial meningitis in our environment with 2-3 cases registered per year . Seventy-two percent of cases occurred in winter and spring . The age of affected children was between 1 month and 13 years . Sixty-five percent of children older than 2 years had a predisposing disease . Penicillin-resistant strains were detected in 1990 and cefotaxime-resistant strains were isolated in 1994 . Seven children (13 %) had severe neurological sequels and two (4 %) died . CONCLUSIONS: Pneumococcal meningitis produces higher morbidity and mortality than other types of bacterial meningitis . The disease usually affects children younger than 2 years and older children with a predisposing disease . In the last few years, the importance of pneumococcal meningitis has increased due to the lower incidence of other types of bacterial meningitis . Because of beta-lactam resistant strains, initial empirical treatment should include vancomycin . The above data suggest the advisability of the generalized use of heptavalent pneumococcal conjugate vaccine in the pediatric population in our environment.

Klin Padiatr, 2001 Sep, 213 Suppl 1, A22 - 37
{Antimicrobial prophylaxis of bacterial infections in pediatric oncology patients}; Simon A et al.; Bacterial infections are still a major challenge in the treatment of pediatric cancer patients . Considering the evidence in the literature and published consensus opinions of experts the following strategies of antibacterial chemoprophylaxis (ABCP) in pediatric cancer patients can be recommended (or not recommended): Accompanying the implantation of a ventriculoperitoneal shunt (or a Rickham-reservoir) ABCP is recommended, until prospective controlled studies including pediatric cancer patients have investigated this issue . In bone marrow or stem cell transplant recipients, the prophylactic administration of penicillin should be considered, if severe oral mucositis is a common adverse event in cancer departments with high rates of penicillin-susceptible strains of Streptococcus viridans . Prospective surveillance of resistant bacterial pathogens should be an indispensable tool of quality control in pediatric oncology departments . The risk of infection with antimicrobial-resistant isolates should be balanced against the real benefit of antimicrobial prophylaxis in every instance . ABCP should neither be given during implantation nor during prolonged usage to prevent bacterial infection of a central venous access device (unproven efficacy and potential hazards of Vancomycin-resistant gram-positive infections) . The oral administration of non-absorbable ABCP or Trimetoprim-Sufomethoxazole is not recommended for the prevention of bacterial infections (unproven efficacy) and no recommendation can be given for the oral ABCP with chinolones (lacking data, risk of antimicrobial resistance).

Diagn Microbiol Infect Dis, 2001 Aug, 40(4), 193 - 8
Fluoroquinolone susceptibility, resistance, and pharmacodynamics versus clinical isolates of Streptococcus pneumoniae from Indiana; Kays MB et al.; The in vitro activity and pharmacodynamics (AUC(0-24)/MIC) of levofloxacin, gatifloxacin, moxifloxacin, and gemifloxacin were evaluated against 307 clinical isolates of Streptococcus pneumoniae from Indianapolis, Indiana . Organisms were collected between January 1999 and April 2000, and MICs were determined by broth microdilution . Serum concentration-time profiles were simulated for the following oral regimens administered once daily: levofloxacin 500 mg and 750 mg; gatifloxacin 400 mg; moxifloxacin 400 mg; gemifloxacin 320 mg . Free 24 h area under the serum concentration-time curves (AUC(0-24)) were calculated, and the average AUC(0-24)/MIC was calculated for each regimen . Differences in AUC(0-24)/MIC among agents were determined by analysis of variance (Scheffe post-hoc test, p < 0.05) . Overall, gemifloxacin was the most potent agent tested . Five (1.7%), 4 (1.3%), and 2 (0.7%) isolates were resistant to levofloxacin, gatifloxacin, and moxifloxacin, respectively . None of the isolates was resistant to gemifloxacin . Gemifloxacin AUC(0-24)/MIC was significantly greater than all other regimens (p < 0.0001), with the exception of moxifloxacin . However, the percent of isolates for which an AUC(0-24)/MIC >or= 30-50 can be achieved is similar for gemifloxacin, moxifloxacin, gatifloxacin, and levofloxacin 750 mg . Large comparative studies are needed to determine if the differences in AUC(0-24)/MIC among fluoroquinolones are clinically significant.

Diagn Microbiol Infect Dis, 2001 Aug, 40(4), 145 - 9
PCR and sequencing of independent genetic targets for the diagnosis of culture negative bacterial endocarditis; Qin X et al.; Molecular methods utilizing broad-range primers for 16S rDNA PCR and sequencing have been widely evaluated for their utility in culture negative diagnostic bacteriology . Difficulties in determining the incidence of false positive PCR results, especially in the absence of an equally sensitive confirmatory method however, have prevented wide clinical use of this sensitive technology . Here we report two cases of culture-negative endocarditis, in which PCR using 16S rDNA broad-range primers generated sequences specific for Bartonella spp . and Streptococcus oralis, respectively . To confirm these results, a second species- or genus-specific molecular target was chosen for each organism and detected in the split samples sequencially . Thus, molecular detection of a second species-specific target can be used to confirm PCR results generated from 16S rDNA broad-range primers and to control for potential false positive results due to environmental and amplicon carry-over contamination during specimen processing and testing in the laboratory.

Int J Pediatr Otorhinolaryngol, 2001 Oct 19, 61(1), 47 - 60
Restricted use of antibiotic prophylaxis for recurrent acute otitis media in the era of penicillin non-susceptible Streptococcus pneumoniae; Block SL et al.; OBJECTIVE/INTERVENTION: To compare the annual rates of acute otitis media (AOM) episodes, antibiotic days, and ventilating tube insertion during the first 3 years of life before and after a practice change to restrict use of antibiotic chemoprophylaxis for recurrent AOM . METHODS SETTING: The sole pediatric private practice in a rural Kentucky community . PATIENTS: Population-based sample of all children born consecutively in two different 13 month intervals . Cohort 1 (n=251) was born before and Cohort 2 (n=274) was born after restricted use of chemoprophylaxis and documented emergence of widespread penicillin non-susceptible Streptococcus pneumoniae (PNSP) . DESIGN: Retrospective case cohort comparison . MAIN OUTCOME MEASURES: Suppurative AOM diagnosed by validated experienced otoscopists using stringent tympanic membrane criteria . RESULTS: Children were mostly white with the majority (50-65%) enrolled in daycare during each year . The first episode of AOM was experienced by 6 and 12 months of age in 64 and 86%, respectively . Rates of children with recurrent AOM in Cohorts 1 and 2 were 28 and 31% in Year 1, 17 and 23% in Year 2, and 7 and 10% in Year 3, respectively . Rates of new onset AOM and persistent AOM episodes were similar between cohorts in the first 2 years . Number of days of antibiotic prophylaxis were reduced from 11.2 to 3.4 days in Year 1, from 11.9 to 2.6 days in Year 2, and from 6.9 to 0.7 days in Year 3, respectively (P<0.0001 for each year) . Total antibiotic days for Years 1, 2 and 3 were reduced commensurately with prophylactic days from 61.7 to 55.5 days (nonsignificant), from 56.3 to 45.8 days (P=0.047), and from 38.7 to 25.7 days (P<0.0001), respectively . For each year a non-significant trend for increased ventilating tube placement from Cohort 1 to Cohort 2, respectively, was observed, 2 versus 2.2%, 4 versus 5.8%, and 0.8 versus 2.6% . Daycare attendance and white race were consistently significant risk factors for AOM and recurrent AOM . CONCLUSIONS: In the era of PNSP, restricted use of antibiotic chemoprophylaxis for recurrent AOM was not associated with significantly increased rates of new onset AOM episodes or tube placement in the first 24 months of life . Total antibiotic days were also significantly reduced in Cohort 2 during Years 2 and 3.

Int J Pediatr Otorhinolaryngol, 2001 Oct 19, 61(1), 23 - 30
Pattern changes of mucin gene expression with pneumococcal otitis media; Tsuboi Y et al.; OBJECTIVE: mucins, known to be important components of the mucociliary transport system in the middle ear and Eustachian tube, are subject to changes under inflammatory conditions . Which mucin genes are up-regulated or activated during an inflammatory reaction of the middle ear and Eustachian tube, however, is poorly understood . The purpose of this study was to characterize mucin gene expression in middle ears and Eustachian tubes with pneumococcal ear infection . METHODS: sixteen rats received intrabullar inoculation of Streptococcus pneumoniae type 6A at 2.5x10(6) colony forming units (CFU) . Four animals were sacrificed on days 1, 3, 7, and 14, respectively . The profile of mucin gene expression in the middle ear and Eustachian tube was examined by reverse transcription polymerase chain reaction (RT-PCR) at the above time points . Sixteen rats that received intrabullar inoculation of phosphate-buffered saline (PBS) served as controls . RESULTS: the Muc2 mucin gene was expressed in middle ear mucosa of the control rats . Following pneumococcal inoculation, Muc1-Muc5 mucin genes were expressed in the middle ear mucosa in a time-dependent manner . In the Eustachian tube, the Muc2, Muc4 and Muc5 mucin genes were expressed in both control and pneumococcal inoculation groups . CONCLUSION: Muc1, Muc3, Muc4, and Muc5 mucin genes were activated in the middle ear mucosa by pneumococci, which may contribute to hyper-production of mucin in acute pneumococcal otitis media.

FEBS Lett, 2001 Sep 21, 505(3), 436 - 40
Stability and DNA-binding properties of the omega regulator protein from the broad-host range Streptococcus pyogenes plasmid pSM19035; Misselwitz R et al.; At the transcriptional level, the pSM19035-encoded omega protein coordinates the expression of proteins required for control of copy number and maintenance of plasmids . Using circular dichroism, fluorescence spectroscopy, ultracentrifugation and an electrophoretic mobility shift assay, the wild-type omega protein and a variant with a C-terminal hexa-histidine tag (omega-H(6)) were characterized . The omega protein is mainly alpha-helical (42%), occurs as homodimer in solution, unfolds thermally with half transition temperatures, T(m), between approximately 43 and approximately 78 degrees C depending on the ionic strength of the buffer, and binds PcopS-DNA with high affinity . The omega-H(6) protein has a modified conformation with lower alpha-helix content (29%), lower thermal stability, and strongly reduced affinity to PcopS-DNA.

J Infect Dis, 2001 Oct 15, 184(8), 1022 - 8 Epub 2001 Aug 31.
Level of maternal antibody required to protect neonates against early-onset disease caused by group B Streptococcus type Ia: a multicenter, seroepidemiology study; Lin FY et al.; Because of the difficulty of conducting efficacy trials of vaccines against group B streptococcus (GBS), the licensure of these vaccines may have to rely on studies that measure vaccine-induced antibody levels that correlate with protection . This study estimates the level of maternal antibody required to protect neonates against early-onset disease (EOD) caused by GBS type Ia . Levels of maternal serum IgG GBS Ia antibodies, measured by ELISAs in 45 case patients (neonates with EOD caused by GBS Ia) and in 319 control subjects (neonates colonized by GBS Ia but without EOD) born at > or =34 weeks gestation were compared . The probability of developing EOD declined with increasing maternal levels of IgG GBS Ia antibody (P = .03) . Neonates whose mothers had levels of IgG GBS Ia antibody > or =5 microg/mL had an 88% lower risk (95% confidence interval, 7%-98%) of developing type-specific EOD, compared with those whose mothers had levels < 0.5 microg/mL . A vaccine that induces IgG GBS Ia antibody levels > or =5 microg/mL in mothers can be predicted to confer a high degree of type-specific immunity to EOD to their infants.

J Clin Microbiol, 2001 Oct, 39(10), 3446 - 51
Sensitive and specific method for rapid identification of Streptococcus pneumoniae using real-time fluorescence PCR; McAvin JC et al.; Molecular surveillance of pathogens has shown the need for rapid and dependable methods for the identification of organisms of clinical and epidemiological importance . As the leading cause of community-acquired pneumonia, Streptococcus pneumoniae was used as a model organism to develop and refine a real-time fluorescence PCR assay and enhanced DNA purification method . Seventy clinical isolates of S . pneumoniae, verified by latex agglutination, were screened against 26 negative control clinical isolates employing a TaqMan assay on a thermocycler (LightCycler) . The probe, constructed from the lytA gene, correctly detected all S . pneumoniae genomes without cross-reaction to negative controls . The speed and ease of this approach will make it adaptable to identification of many bacterial pathogens and provide potential for adaptation to direct detection from patient specimens.

Int J Antimicrob Agents, 2001, 18 Suppl 1, S63 - 70
Treatment of community-acquired pneumonia in hospitalised patients; Mulazimoglu L; Community-acquired pneumonia (CAP) can be life-threatening . The prognosis is generally poorest in elderly patients and/or those with underlying chronic conditions, but fatalities can occur in all age groups . Current challenges in the clinical management of CAP are discussed, and the criteria for identifying those patients who should be treated in hospital with initial intravenous therapy are considered . Rapid initiation of therapy is important, using an agent that provides coverage against the most likely pathogens--Streptococcus pneumoniae and the atypical organisms . There is an increasing tendency to minimise the duration of intravenous therapy, with an early transition to oral therapy and the rapid return of the patient to the community . The efficacy of oral macrolides in the treatment of CAP is well established . Evidence for the use of intravenous azithromycin to provide effective and well-tolerated, first-line intervention in the hospitalized CAP patient is summarised.

Int J Antimicrob Agents, 2001, 18 Suppl 1, S33 - 8
The clinical impact of macrolide resistance in pneumococcal respiratory infections; Garau J; By the 1960s, several reports of bacteria with reduced susceptibility to antibiotics were published . In recent years, the problem of antibiotic resistance has magnified . In the treatment of respiratory tract infections, the development of resistance is of particular concern; 67% of antibiotic use in adults and 87% in children is for the treatment of such infections . Streptococcus pneumoniae is the most common cause of community-acquired pneumonia and is a frequently isolated bacterial species in patients with other respiratory tract infections . Increasing levels of resistance may have important implications in the clinical setting . Physicians need to consider local susceptibility data, in addition to the pharmacokinetic and pharmacodynamic features of compounds, when selecting appropriate antibiotics for the treatment of bacterial infections.

Vet Microbiol, 2001 Nov 26, 83(3), 287 - 97
Prevalence and mechanism of resistance against macrolides and lincosamides in Streptococcus suis isolates; Martel A et al.; Eighty-seven Streptococcus suis isolates recovered in 1999-2000 from diseased pigs, all from different farms, were screened for resistance against macrolide and lincosamide antibiotics by the disk diffusion and agar dilution test and a PCR assay, amplifying the ermB gene and the mefA/E gene . Seventy-one percent of the isolates showed constitutive resistance to macrolide and lincosamide antibiotics (MLS(B)-phenotype) . All these isolates were positive for the ermB gene in the PCR, but negative for the mefA/E gene . For all strains minimum inhibitory concentrations (MIC) against five other antimicrobial agents were determined . All strains were susceptible to penicillin . Ninety-nine percent of the isolates were susceptible to enrofloxacin and tiamulin . Eighty-five percent of the strains were resistant to doxycycline . A 540bp fragment of the ermB genes of eight S . suis strains was sequenced and compared with ermB genes of five S . pneumoniae and five S . pyogenes strains of human origin . A 100% homology was found between these fragments in seven S . suis, one S . pneumoniae and three of the S . pyogenes isolates . This study demonstrates that resistance against macrolides, lincosamides and streptogramin B is widespread in S . suis and mediated by ribosome methylation, encoded by the ermB gene.

Nephrol Dial Transplant, 2001 Oct, 16(10), 2067 - 71
OK432-induced killer cell activity: potential method for monitoring immunological complications after renal transplantation; Nishikido M et al.; BACKGROUND: Various clinical and biochemical parameters are currently in use for monitoring allograft rejection . However, the mechanism of allograft rejection is complex and it is frequently difficult to obtain a prompt and accurate diagnosis . We examined the usefulness of OK432-induced killer cell activity as an immunological monitoring system for acute renal rejection after renal transplantation . METHODS: Twenty-four renal transplant recipients, seven patients on haemodialysis, and 10 normal volunteers were enrolled in our study . The killer cell activity of peripheral blood mononuclear cells was induced by culturing these cells with the immunopotentiator, OK432, a heat and penicillin-treated lyophilized powder of the Su-strain of Streptococcus pyogenes . RESULTS: The OK432-induced killer cell activity of renal transplant recipients without acute rejection (stable recipients) was significantly lower than in normal volunteers . In four renal transplant recipients with acute rejection, the killer cell activity was significantly higher than in stable recipients . In three recipients suffering from opportunistic infections, killer cell activity was significantly suppressed compared with stable recipients . CONCLUSIONS: Our new test utilizing OK432-induced killer cell activity is potentially useful for monitoring the immunological state and complications after renal transplantation.

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