Jpn J Ophthalmol, 1999 Sep-Oct, 43(5), 368 - 74 Experimental uveitis induced by intravitreal or intravenous lipoteichoic acid in rabbits; Chen J et al.; PURPOSE: To investigate the role of lipoteichoic acid (LTA), one of the cell wall components in gram-positive bacteria in uveitis . METHODS: Intraocular inflammation in rabbit eyes was induced by intravitreal or intravenous injections of LTA from Staphylococcus aureus or Streptococcus sanguis . The inflammation was monitored progressively with the laser flare-cell photometer, and examined by periodic clinical observations . Histological examinations were performed 24 hours after administration, and aqueous protein concentrations and cell counts were also determined . RESULTS: Intraocular inflammation appeared within 6-9 hours of LTA intravitreal injection . became maximal at about 24-48 hours postinjection, and lasted for nearly 6 days . Intraocular inflammation was also induced by intravenous injection of LTA at a higher dose . Inflammation reached a peak 4-5 hours after injection, and rapidly disappeared in 24 hours . No cellular response was observed in intravenous LTA-treated eyes . CONCLUSIONS: This study demonstrates that LTAs from gram-positive bacteria have the biological activity to induce intraocular inflammation in rabbits by intravitreal or intravenous injection . Therefore, we suggest that LTA may play a role in the pathogenesis of uveitis as one of the etiological factors. Glycoconj J, 1999 Jan, 16(1), 67 - 71 Determination of the cell adhesion specificity of Streptococcus suis with the complete set of monodeoxy analogues of globotriose; Haataja S et al.; Streptococcus suis causes meningitis and other serious infections in pigs and humans, and binds to host cell globotriosylceramide . In order to determine the essential hydroxyls involved in binding, the complete set of monodeoxy derivatives of the receptor trisaccharide Gal alpha1-Gal beta1-4Glc were tested as inhibitors of bacterial hemagglutination . Removal of the 4''-, 6'', 2' or 3'-hydroxyls abolished inhibitory activity, which indicated that they were critically involved in binding . The same results were obtained using synthetic lipid-linked monodeoxy derivatives of the trisaccharides in a thin-layer overlay assay . The P(N) and P(O) subtypes of the S . suis adhesin showed similar binding patterns . The hydroxyls of the glucose moiety were not critical for binding, although the adhesin binds better to the trisaccharide Gal alpha1-4Gal beta1-4Glc than the disaccharide Gal alpha1-4Gal. Arch Oral Biol, 1999 Nov, 44(11), 901 - 6 Effects of topical application of free and liposome-encapsulated lactoferrin and lactoperoxidase on oral microbiota and dental caries in rats; Martinez-Gomis J et al.; Four groups of rats were inoculated with Streptococcus sobrinus ATCC 33478 and fed a cariogenic diet for 42 days . Topical treatment with either distilled water, sodium fluoride (0.2%), a solution containing lactoferrin and lactoperoxidase, or a solution containing liposome-encapsulated lactoferrin and liposome-encapsulated lactoperoxidase was applied at intervals for 35 days . Caries incidence in groups treated with liposome-encapsulated lactoferrin and lactoperoxidase was significantly lower than in control groups . The number of viable Strep . sobrinus and the proportion of Strep . sobrinus in the total counts were significantly higher in liposome-treated groups . Free lactoferrin and lactoperoxidase did not cause a significant reduction in caries incidence. J Microbiol Methods, 1999 Dec, 39(1), 17 - 22 A novel staining method for detecting phytase activity; Bae HD et al.; Differential agar media for the detection of microbial phytase activity use the disappearance of precipitated calcium or sodium phytate as an indication of enzyme activity . When this technique was applied to the study of ruminal bacteria, it became apparent that the method was unable to differentiate between phytase activity and acid production . Strong positive reactions (zones of clearing around microbial colonies) observed for acid producing, anaerobic bacteria, such as Streptococcus bovis, were not corroborated by subsequent quantitative assays . Experimentation revealed that acidic solutions generated false positive results on the selected differential medium . Empirical studies undertaken to find a solution to this limitation determined the false positive results could be eliminated through a two step counterstaining treatment (cobalt chloride and ammonium molybdate/ammonium vanadate) which reprecipitates acid solubilized phytate . This report discusses the application of the developed two step counterstaining treatment for the screening of phytase producing ruminal bacteria as well as its use in phytase zymogram assays. J Microbiol Methods, 2000 Jan, 39(2), 133 - 43 A sensitive method to detect initiation of growth in Streptococcus gordonii using ribosomal RNA operon-reporter gene fusions; Natarajan A et al.; A system for studying the early growth response of Streptococcus gordonii to environmental stimuli has been developed . A reporter gene, encoding alpha-amylase, has been integrated into an rRNA operon to monitor changes in cellular physiology associated with the initiation of growth . Two such strains with single integrants have been characterized during the transition from lag phase to exponential growth . Synthesis of the reporter is correlated to growth initiation in both strains, and the reporter enzyme is detectable with sufficient sensitivity . Comparison of the expression profiles of the two rrn operons containing the reporter gene suggests that they are differentially expressed over the course of growth. Int J Pediatr Otorhinolaryngol, 1999 Oct 25, 50(2), 113 - 7 Acute mastoiditis in children--our experience; Vera-Cruz P et al.; The incidence of acute mastoiditis and the number of complications has changed since the 1950s, despite the increasing antibiotic effectiveness . Other series concluded that the incidence of acute mastoiditis is rising in the recent years, which can be justified by the antibiotic resistance of the microorganisms and the absence of paracentesis in the treatment of acute otitis media . Our aim is to approach risk factors, clinical presentation, diagnosis and treatment of acute mastoiditis . We reviewed 62 clinical records of patients in pediatric age, observed in D . Estefania Hospital Lisbon, between January 1993 and December 1997 . There was a relative homogenous distribution during the 5 years of the study period . The patient age ranged from 5 months to 14 years . They all were treated with intravenous antibiotics . The mean duration of treatment was 7.4 days . We registered 15 complications: 14 retroauricular subperiosteal abscesses and one subdural empyema . The most common isolated microorganism was Streptococcus pneumoniae . We found no statistic difference (P > 0.1) in the incidence of acute mastoiditis between the 5 years of the study. Lab Invest, 1999 Nov, 79(11), 1393 - 401 Rapid appearance of M cells after microbial challenge is restricted at the periphery of the follicle-associated epithelium of Peyer's patch; Borghesi C et al.; M cells within the follicle-associated epithelium (FAE) of the gut play a central role in the initiation of mucosal immune responses by transporting antigens to the intestinal lymphoid tissue . We have previously demonstrated that the instillation into the gut of a nonenteric microorganism, Streptococcus pneumoniae R36a, is an excellent experimental model to investigate the highly dynamic nature of the FAE in response to microbial challenge . In the present study, S . pneumoniae was introduced into rabbit ileal loops, each one containing a Peyer's patch (PP), and the number of M cells was assessed by morphological and functional characteristics in different areas of the FAE after a short time (1-3 hours) . We report that a marked increase in the number of M cells was detected in the periphery, but not in the apical area, of the FAE as early as 1 hour after exposure to S . pneumoniae . Furthermore, a variant of this experiment enabled us to establish that the increased numbers of M cells led to an improved capability of the FAE to transport latex fluorescent microspheres (0.5 microm), highly specific to rabbit M cells, from the gut lumen to the intestinal lymphatic system . In these animals the cisterna chyli was cannulated, and the microparticles were introduced into the intestinal loops after stimulation with pneumococci . The microparticles reaching the lymph were then counted by flow cytometer . We interpreted these results as showing that only enterocytes located within the periphery of the FAE are converted to fully operational M cells by certain microbial interaction and the ability of enterocytes to undergo this conversion may depend on their stage of differentiation. J Korean Med Sci, 1999 Oct, 14(5), 475 - 9 Evaluation of antibody responses to pneumococcal vaccines with ELISA and opsonophagocytic assay; Kim KH et al.; Antibodies to a capsular polysaccharide (PS) provide protection against Streptococcus pneumoniae which express the homologous capsular serotype, and pneumococcal vaccines are designed to induce antibodies in the capsular PS . Levels and opsonophagocytic capacity of antibodies to the capsular PS of S . pneumoniae serotype 19F were determined by sera from adults immunized with 23-valent S . pneumoniae capsular PS vaccines . Geometric means of IgG anti-19F antibody level and specific opsonic titer rise significantly after immunization . The level of anticapsular PS antibodies for S . pneumoniae 19F serotype is fairly well correlated (r2=O.63) with the opsonophagocytic activities of sera . However, 3.7% (1/27) of serum samples display strikingly less opsonophagocytic activity than expected on the basis of their antibody level . Thus, antibody level may be of general use in predicting vaccine-induced protection among adults for 19F serotype . However, the opsonic activity data suggest that antibody levels are not always indicative of functional antibody. Scand J Infect Dis, 1999, 31(5), 509 - 10 Toxic-shock-like-syndrome due to Streptococcus pneumoniae sinusitis; Friedstrom SR et al.; We describe a patient with Streptococcus pneumoniae sinusitis associated with a severe sepsis syndrome and desquamative rash whose clinical illness strongly resembled toxic-shock syndrome . Assay of convalescent serum for antibodies to toxic-shock syndrome toxin 1 was negative . This case suggests the possibility of an additional bacterial pathogen associated with toxic-shock syndrome. Int J Infect Dis, 1999 Summer, 3(4), 211 - 5 Nasopharyngeal carriage of multidrug-resistant Streptococcus pneumoniae in institutionalized HIV-infected and HIV-negative children in northeastern Romania; Leibovitz E et al.; OBJECTIVES: The study compared nasopharyngeal carriage of resistant pneumoniae in human immunodeficiency virus (HIV)-seropositive and -seronegative children . METHODS: Nasopharyngeal colonization with Streptococcus pneumoniae was investigated during May 1996 in 162 HIV-negative infants and children (age range, 1-38 mo) and 40 HIV-infected children (age range, 39-106 mo) living in an orphanage in Iasi, northeastern Romania . The HIV-infected children lived separated from the other children and were cared for by a different staff . Streptococcus pneumoniae was isolated from 12 of 40 (30%) HIV-infected and from 81 of 160 (50%) HIV-negative children . Antimicrobial susceptibility to penicillin and ceftriaxone was determined by E-test, and to another five antibiotics by disk diffusion . Serotyping was performed by the Quellung method on 81 of 93 (87%) isolates . RESULTS: Serotypes 6A, 6B, 19A, and 23F together represented 98% of all isolates . Ninety-nine percent of S . pneumoniae isolates were resistant to penicillin, and 74% were highly resistant to penicillin (minimum inhibitory concentration {MIC} > 1 mg/mL); MIC50 and MIC90 to penicillin of the isolates were 2 mg/mL and 8 mg/mL, respectively . Eighty-nine of ninety-one isolates were susceptible to ceftriaxone; 99%, 87%, 87%, 48%, and 21% of the isolates were resistant to trimethoprim-sulphamethoxazole, erythromycin, clindamycin, tetracycline, and chloramphenicol, respectively . Eighty-two (89%) isolates were multidrug resistant (resistant to =/>3 antibiotic classes); 37 of 92 (40%) isolates were resistant to 5 or more antibiotic classes, and 16 of these 37 (43%) belonged to serotype 19A . All serotype 19 isolates were highly resistant to penicillin . CONCLUSIONS: No significant differences were observed in the resistance rates of S . pneumoniae in HIV-infected children compared to HIV-negative children . Multidrug-resistant pneumococci were highly prevalent in this Romanian orphanage in both HIV-negative and older HIV-infected children . The observed high prevalence of multidrug-resistant pneumococci (coupled with high penicillin resistance) with a limited number of circulating serotypes emphasizes the need to further evaluate the conjugate vaccines in children at risk for invasive pneumococcal infection. J Biomed Mater Res, 2000 Feb, 49(2), 250 - 6 Adherence of Streptococcus mutans to an E-glass fiber-reinforced composite and conventional restorative materials used in prosthetic dentistry; Tanner J et al.; The adherence of Streptococcus mutans to E-glass used in fiber-reinforced composites, denture base polymer, and four other restoratives was investigated . The materials were studied with and without a parotid saliva and serum pellicle . Specimens of the studied materials (E-glass, denture base polymer, titanium, cobalt-chromium alloy, gold alloy, and grained feldspar ceramic) were incubated in a suspension of S . mutans, allowing initial adhesion to occur . The degree of bacterial adhesion was studied using scanning electron microscopy (SEM) . The studied uncoated materials showed rather similar adhesion of S . mutans . Saliva coating resulted in a decrease of adherence to all materials except glass . With a saliva pellicle E-glass showed the strongest ability to bind S . mutans, and it differed significantly from the other studied materials . Serum coating markedly decreased adhesion to all materials, and only minor differences among the studied materials were observed . The results of this study suggest that the studied restoratives are rather similar with respect to S . mutans adhesion and that a saliva pellicle may promote adhesion of S . mutans to glass fibers . J Paediatr Child Health, 1999 Oct, 35(5), 466 - 71 Streptococcus pneumoniae antibiotic resistance in Northern Territory children in day care; Skull S et al.; BACKGROUND: There is evidence that the rapid rise in Streptococcus pneumoniae (SP) antimicrobial resistance seen in other countries may have commenced in Australia . Streptococcus pneumoniae carriage and resistance levels are described for urban Northern Territory children in day care . METHODS: A prospective cohort study was conducted of 250 children in nine Darwin day care centres between 24 March and 15 September 1997 . Each fortnight nasopharyngeal swabs were collected from children, and parents were interviewed about medications administered . RESULTS: Streptococcus pneumoniae was detected in 52% (1028/1974) of all nasopharyngeal swabs . Streptococcus pneumoniae was isolated from 92% (231/250) of children at some time . Penicillin resistance was found in 30% (312/1028) of isolates using a screening test . Of these, 256 (82%) had resistance confirmed by E-test . Two hundred and one (20% of all isolates) had intermediate penicillin resistance and 55 (5% of all isolates) had high level resistance . Ceftriaxone resistance was found in 19% of children's first isolates . Resistance to other antibiotics was also common: co-trimoxazole 45%, erythromycin 17%, tetracycline 17% and chloramphenicol 13% . A total of 17% (172/1028) of the isolates were multiresistant . The average fortnightly proportion of children given antibiotics was 16% (405/2476) . CONCLUSION: Levels of intermediate and high level penicillin resistance in this day care population are consistent with previous data from the Northern Territory, and considerably higher than the rest of Australia . The national trend of increasing pencillin resistance is likely to continue. J Immunol, 1999 Dec 1, 163(11), 6139 - 47 Lipoteichoic acid inhibits lipopolysaccharide-induced adhesion molecule expression and IL-8 release in human lung microvascular endothelial cells; Blease K et al.; Cell adhesion molecule expression (CAM) and IL-8 release in lung microvascular endothelium facilitate neutrophil accumulation in the lung . This study investigated the effects of lipoteichoic acid (LTA), a cell wall component of Gram-positive bacteria, alone and with LPS or TNF-alpha, on CAM expression and IL-8 release in human lung microvascular endothelial cells (HLMVEC) . The concentration-dependent effects of Staphylococcus aureus (S . aureus) LTA (0.3-30 microg/ml) on ICAM-1 and E-selectin expression and IL-8 release were bell shaped . Streptococcus pyogenes (S . pyogenes) LTA had no effect on CAM expression, but caused a concentration-dependent increase in IL-8 release . S . aureus and S . pyogenes LTA (30 microg/ml) abolished LPS-induced CAM expression, and S . aureus LTA reduced LPS-induced IL-8 release . In contrast, the effects of S . aureus LTA with TNF-alpha on CAM expression and IL-8 release were additive . Inhibitory effects of LTA were not due to decreased HLMVEC viability, as assessed by ethidium homodimer-1 uptake . Changes in neutrophil adhesion to HLMVEC paralleled changes in CAM expression . Using RT-PCR to assess mRNA levels, S . aureus LTA (3 microg/ml) caused a protein synthesis-dependent reduction (75%) in LPS-induced IL-8 mRNA and decreased the IL-8 mRNA half-life from >6 h with LPS to approximately 2 h . These results suggest that mechanisms exist to prevent excessive endothelial cell activation in the presence of high concentrations of bacterial products . However, inhibition of HLMVEC CAM expression and IL-8 release ultimately may contribute to decreased neutrophil accumulation, persistence of bacteria in the lung, and increased severity of infection. Microb Drug Resist, 1999 Fall, 5(3), 219 - 25 Streptococcus pyogenes isolated in Portugal: macrolide resistance phenotypes and correlation with T types . Portuguese Surveillance Group for the Study of Respiratory Pathogens; Melo-Cristino J et al.; From January 1998 to June 1999, 302 clinical isolates of Streptococcus pyogenes were collected from 10 microbiology laboratories in Portugal . All strains were highly sensitive to penicillin (MIC90 = 0.012 mg/liter) . The prevalence of erythromycin resistance was 35.8% and of tetracycline resistance 41.4% . The majority (79.6 %) of erythromycin-resistant strains were of the MLSB constitutive resistance (CR) phenotype with high-level resistance to erythromycin (MIC90 >256 mg/liter) and to clindamycin (MIC90 >256 mg/liter), 16.7% showed the M phenotype with low-level erythromycin-resistance (MIC90 = 24 mg/liter) and susceptibility to clindamycin, and four isolates showed a phenotype characterized by low-level erythromycin resistance (MIC90 = 8 mg/liter) and high-level clindamycin resistance (MIC90 >256 mg/liter), not previously described . Erythromycin resistance was not associated with invasive strains . Only minor discrepancies between disk diffusion and E-test methods were observed . T serotyping was very useful for the epidemiological characterization of the strains . The most prevalent T types were T1, T4, T9, T12, T13, and T28 . A statistically significant association with resistance patterns was found: T12 with erythromycin resistance MLS(B) CR phenotype (p< 0.001), T4 with erythromycin resistance M phenotype (p<0.001), and T13 with tetracycline resistance (p<0.01) . Because of the high prevalence of resistance, careful surveillance of S . pyogenes isolates in Portugal is essential, routine antimicrobial susceptibility testing in clinical microbiology laboratories should be strongly encouraged, antibiotic prescription should be reviewed, and macrolides should no longer be used in the empirical therapy of acute pharyngitis. Microb Drug Resist, 1999 Fall, 5(3), 215 - 8 Antimicrobial susceptibility of invasive Streptococcus pneumoniae in Italy by agar dilution method and E test; Tarasi A et al.; Few data on antimicrobial susceptibility of invasive Streptococcus pneumoniae isolated in Italy are available . Ninety-two invasive isolates from all over the country collected from January 1997 to April 1998 were tested for sensitivity to penicillin, erythromycin, ceftriaxone, chloramphenicol, tetracycline, and trimethoprim/sulfamethoxazole by the agar dilution method . Five (5.4%) strains were resistant to penicillin (one highly, four intermediately resistant), 8 (8.7%) to chloramphenicol, 27 (29.3%) to erythromycin, 17 (18.5%) to tetracycline (16 highly, one intermediately), and 21 (22.8%) to trimethoprim/sulfamethoxazole (14 highly, 7 intermediately) . All strains were susceptible to ceftriaxone, although the penicillin-resistant strain had the highest minimal inhibitory concentration . (MIC) value (0.5 microg/ml); three penicillin-resistant strains were also resistant to erythromycin . Eight strains were multi-drug resistant, being also resistant to at least three antibiotics . The commercially available E test was compared with the standard agar dilution method for the determination of MIC of penicillin, erythromycin, ceftriaxone, chloramphenicol, and trimethoprim/sulfamethoxazole . E test established the same susceptibility categories for 100% of the strains tested for penicillin and ceftriaxone, 99% for chloramphenicol, 97% for erythromycin, and 74% for trimethoprim/sulfamethoxazole . According to our results, E test was simple to perform, easy to interpret, and a valid method for susceptibility testing of S . pneumoniae . Our study shows that in Italy the rate of penicillin resistance in invasive isolates of S . pneumoniae is one of the lowest in Europe (5.4%), while the rate of erythromycin is very high (29.3%) and is reaching the highest rates of other Southern European countries. Microb Drug Resist, 1999 Fall, 5(3), 201 - 5 Epidemiological studies on drug resistance in Streptococcus pneumoniae in Hungary: an update for the 1990s; Marton A et al.; The aim of this study was to give an overview about the epidemiological features of pneumococcal resistance in Hungary in the 1990s, and to assess the clinical relevance of drug resistance in Streptococcus pneumoniae primarily in upper respiratory tract infections and the role of risk factors in the acquisition of resistant strains . In Hungary, resistance in S . pneumoniae decreased slightly in recent years, but is still highly prevalent (around 40% to penicillin) compared to the prevalence in western and northern neighboring countries . The prevalent serogroup among resistant strains is 19A, as it was several years ago . In 76 case histories studies, chronic underlying diseases associated with long hospitalization, episodes of earlier hospitalization, and antibiotic therapy were found more frequently if the patient was infected with a resistant strain than with a susceptible one, indicating that these factors promote the acquisition of drug-resistant S . pneumoniae . Resistant S . pneumoniae modified the course of infection by prolonging the duration of hospitalization, making more courses of antibiotics necessary, including parenteral drugs, as well as more invasive interventions such as myringotomy and sinus puncture . These data justify the clinical relevance of resistance, particularly in the upper respiratory tract infections. Microb Drug Resist, 1999 Fall, 5(3), 183 - 8 Induction of ribosome methylation in MLS-resistant Streptococcus pneumoniae by macrolides and ketolides; Zhong P et al.; One major mechanism for resistance to macrolide antibiotics in Streptococcus pneumoniae is MLS (macrolide, lincosamide, and streptogramin B) resistance, manifested when the 23S rRNA is methylated by the product of an erm gene . This modification results in the decreased binding of all known macrolide, lincosamide, and streptogramin B antibiotics to the ribosome . More than 30 ermAM-containing clinical isolates of S . pneumoniae were examined in our lab and showed high-level resistance (MIC > or =128 microg/ml) to erythromycin, azithromycin, tylosin, clindamycin, and ketolide (macrolides that lack the cladinose sugar) TE-802 . We found that the new generation of ketolides A965 and A088 displayed variable activity against the same group of resistant S . pneumoniae strains . To understand the basis of variability of the minimal inhibitory concentration (MIC) values of A965 and A088, we examined the effects of a series of macrolides and ketolides on the level of 23S rRNA methylation in five ermAM-containing resistant S . pneumoniae isolates . We show here that the basal levels of ribosomal methylation vary from strain to strain . The level of rRNA methylation can be strongly induced by erythromycin, azithromycin, and TE-802, resulting in high-level of resistance to these compounds . Ketolide A965 and A088, however, are weak inducers at sub-MIC drug concentrations, therefore showing variable activities in strains with differential methylation levels. J Agric Food Chem, 1999 Jan, 47(1), 61 - 6 Productivity and some properties of immunoglobulin specific against Streptococcus mutans serotype c in chicken egg yolk (IgY); Chang HM et al.; Hens were immunized on thighs by using whole cells of Streptococcus mutans MT8148 serotype c strain as antigen through intramuscular (im) and subcutaneous (sc) routes to investigate the difference of immunization reactions and the changes in yolk antibody activities against antigen after initial immunization . Several properties of crude IgY were examined to evaluate the stability during food processing . Results showed that the specificity of IgY of im treated hens was nearly 10 times as high as those of sc treated antibody . IgY from the hens immunized with the serotype c strain showed significant cross-reactions against serotypes e and f, while minor reactions against serotypes a, b, d, and g were observed . In thermal stability tests, IgY activity in both yolk and crude IgY decreased with the increasing temperature, from 70 to 80 degrees C, but the thermal denaturation rates between those two samples were not significantly different . The addition of high levels sucrose, maltose, glycerol, or 2% glycine displayed effective protection against thermal denaturation of IgY . Lyophilized yolk-5% gum arabic powder showed better stability against proteases. Infect Immun, 1999 Dec, 67(12), 6707 - 9 Role of keratinocyte injury in adherence of Streptococcus pyogenes; Darmstadt GL et al.; Keratinocytes injured acutely by UVB light or lipopolysaccharide were used to test the hypothesis that keratinocyte injury promotes bacterial adherence and the development of group A streptococcal skin infections . Injury did not affect adherence to undifferentiated and differentiated keratinocytes, but keratinocyte differentiation promoted adherence four- to fivefold. Infect Immun, 1999 Dec, 67(12), 6533 - 42 The pspC gene of Streptococcus pneumoniae encodes a polymorphic protein, PspC, which elicits cross-reactive antibodies to PspA and provides immunity to pneumococcal bacteremia; Brooks-Walter A et al.; PspC is one of three designations for a pneumococcal surface protein whose gene is present in approximately 75% of all Streptococcus pneumoniae strains . Under the name SpsA, the protein has been shown to bind secretory immunoglobulin A (S . Hammerschmidt, S . R . Talay, P . Brandtzaeg, and G . S . Chhatwal, Mol . Microbiol . 25:1113-1124, 1997) . Under the name CbpA, the protein has been shown to interact with human epithelial and endothelial cells (C . Rosenow et al., Mol . Microbiol . 25:819-829, 1997) . The gene is paralogous to the pspA gene in S . pneumoniae and was thus called pspC (A . Brooks-Walter, R . C . Tart, D . E . Briles, and S . K . Hollingshead, Abstracts of the 97th General Meeting of the American Society for Microbiology 1997) . Sequence comparisons of five published and seven new alleles reveal that this gene has a mosaic structure, and modular domains have contributed to gene diversity during evolution . Two major clades exist: clade A alleles are larger and contain an extra module that is shared with many pspA alleles; clade B alleles are smaller and lack this pspA-like domain . All alleles have a proline-rich domain and a choline-binding repeat domain that show 0% divergence from similar domains in the PspA protein . Immunization of a rabbit with a recombinant clade B PspC molecule produced antiserum that cross-reacted with both PspC and PspA from 15 pneumococcal isolates . The cross-reactive antibodies afforded cross-protection in a mouse model system . Mice immunized with PspC were protected against challenge with a strain that expressed PspA but not PspC . The PspA- and PspC-cross-reactive antibodies were directed to the proline-rich domain present in both molecules. Infect Immun, 1999 Dec, 67(12), 6350 - 7 Group B streptococcal surface proteins as targets for protective antibodies: identification of two novel proteins in strains of serotype V; Areschoug T et al.; Strains of group B streptococcus (GBS) express surface proteins that confer protective immunity . In particular, most strains of the four classical capsular serotypes (Ia, Ib, II, and III) express either of the Rib and alpha proteins, two members of the same protein family . Here, we report a study of surface proteins expressed by strains of serotype V, which has recently emerged as an important serotype among GBS strains causing serious disease . Two novel GBS proteins were identified, purified, and characterized . One of these proteins, designated Fbs, was immunologically unrelated to other GBS surface proteins . This approximately 110-kDa protein was found in 15 of 49 (31%) type V isolates but in few strains of other serotypes . The Fbs proteins expressed by different strains showed limited variation in size . The most common surface protein among type V strains, found in 29 of 49 (59%) isolates, was designated Rib-like, since it cross-reacted with Rib but was not immunologically identical to Rib . Characterization of this Rib-like protein showed that the N-terminal sequence (12 residues) was identical to that of alpha, although these two proteins lacked cross-reactivity . The biochemical and immunological properties of the Rib-like GBS protein indicate that it is closely related to the R28 protein of Streptococcus pyogenes . Importantly, passive and active immunization experiments with mice showed that the Fbs and Rib-like proteins are targets for protective antibodies . These two proteins are therefore of interest for analysis of pathogenic mechanisms and for vaccine development. Curr Microbiol, 2000 Jan, 40(1), 61 - 6 Sequence analysis of a small cryptic plasmid isolated from Streptococcus suis serotype 2; Takamatsu D et al.; A small cryptic plasmid designated pSSU1 was isolated from Streptococcus suis serotype 2 strain DAT1 . The complete sequence of pSSU1 was 4975 bp and contained six major open reading frames (ORFs) . ORF1 and ORF2 encode for proteins highly homologous to CopG and RepB of the pMV158 family, respectively . ORF5 encodes for a protein highly homologous to Mob of pMV158 . ORF4 encodes for a protein highly homologous to orf3 of pVA380-1 of S . ferus, but its function is unknown . There was no similarity between ORF3 and ORF6 and other protein sequences . In this plasmid, the ORF1 (CopG protein) was preceded by two multiples of direct repeat and the conserved nucleotides that could be the double-strand origin (DSO) of rolling circle replication (RCR) mechanism . The ORF5 (Mob protein) was followed by a potential hairpin loop that could be the single-strand origin (SSO) of RCR mechanism . The sequence, which was complementary to the leader region of Rep mRNA, was homologous to the countertranscribed RNA (ctRNA) of pLS1 . Moreover, a 5-amino acid conserved sequence was found in C terminal of Rep and putative Rep proteins of several pMV158 family plasmids . These observations suggest that this plasmid replicates by use of the rolling circle mechanism. J Clin Microbiol, 1999 Dec, 37(12), 4198 - 200 Lumbar vertebral osteomyelitis with mycotic abdominal aortic aneurysm caused by highly penicillin-resistant Streptococcus pneumoniae; Naktin J et al.; We present a case of vertebral osteomyelitis with an adjacent abdominal aortic mycotic aneurysm caused by a highly penicillin-resistant Streptococcus pneumoniae strain . The occurrence of all three phenomena in a single patient has not been previously described . This presentation offers the opportunity to reflect on the increasing incidence of S . pneumoniae as a resistant pathogen, the treatment of highly penicillin-resistant S . pneumoniae, and the etiologic agents of both vertebral osteomyelitis and mycotic aneurysm. J Clin Microbiol, 1999 Dec, 37(12), 4131 - 4 Characteristics of Streptococcus pyogenes serotype M1 and M3 isolates from patients in Japan from 1981 to 1997; Murase T et al.; Streptococcus pyogenes isolates obtained in 1981 to 1997 from patients and healthy subjects were characterized by pulsed-field gel electrophoresis (PFGE) patterns, biotyping, and the presence of spe genes encoding streptococcal pyrogenic exotoxins . Changes in the profiles were shown in the serotype M1/T1 isolates from pharyngitis over this period, but not in serotype M3/T3 isolates . The characteristics of isolates from patients with toxic shock-like syndrome (TSLS) were comparable to those of the other isolates, including those from healthy subjects . This finding suggests that further phenotypic and molecular characterization, such as investigating the genomic difference represented by the pathogenicity island, of isolates with apparently the same profiles would be necessary to determine the etiology of diseases caused by S . pyogenes, including TSLS. J Clin Microbiol, 1999 Dec, 37(12), 4039 - 41 Genetic relatedness among nontypeable pneumococci implicated in sporadic cases of conjunctivitis; Barker JH et al.; Nontypeable Streptococcus pneumoniae is a common cause of epidemic conjunctivitis . A previous molecular fingerprinting study identified a clone of nontypeable pneumococcus that was responsible for a recent outbreak of conjunctivitis . In the present study, we examined the extent to which pneumococci that cause sporadic cases of conjunctivitis are related to this epidemic strain . Using arbitrarily primed BOX-PCR, we have determined that, of 10 nontypeable pneumococci causing sporadic conjunctivitis, 5 were clonal and closely related to a previous outbreak strain, whereas 5 others were genetically diverse. J Pharmacol Exp Ther, 1999 Dec, 291(3), 1086 - 92 Streptococcus pneumoniae pneumonia in mice: optimal amoxicillin dosing predicted from a pharmacokinetic-pharmacodynamic model; Moine P et al.; In an attempt to better understand the interaction of amoxicillin with Streptococcus pneumoniae in the lung, and to determine the parameters of therapeutic efficacy of the antimicrobial agent amoxicillin, we used a pharmacokinetic-pharmacodynamic model to describe the overall dose-effect relationship of amoxicillin against 12 strains of S . pneumoniae with penicillin minimum inhibitory concentrations ranging from <0.01 to 16 microg/ml in a neutropenic murine pneumonia model . We were able to correlate amoxicillin dosing, pharmacokinetics, and the temporal changes in bacterial count in lung . Moreover, survival rates measured in one strain at different dosing were significantly related to the number of bacteria in lung calculated from the pharmacokinetic-pharmacodynamic model . Disappearance of amoxicillin from the effect compartment appeared to be very slow and the rate constant (k(e0)) governing this process was significantly different between strains, ranging from 0.00131 to 0.03945 h(-1) . These findings have two major implications: 1) after a single dose of amoxicillin, bacterial counts in lung rapidly decreased and the bacterial growth remained suppressed during a long period of time after cessation of exposure of microorganisms to amoxicillin; and 2) the duration of bacterial growth suppression was related to the intrinsic properties of S . pneumoniae strains rather than to host environment because k(e0) was significantly different between strains . These two premises clearly demonstrate that bacterial growth suppression is related to an in vivo postantibiotic effect . Furthermore, we have shown that the major determinant of amoxicillin in vivo bactericidal activity and therapeutic efficacy appeared to be the dose of amoxicillin because amoxicillin exhibits a rapid dose-dependent killing regardless of the S . pneumoniae strain . Our findings may have implications for the clinical use of amoxicillin . In view of our results, the guidance to increase the amoxicillin-loading dose in pneumococcal pneumonia appears to be immediately clinically relevant. No To Hattatsu, 1999 Nov, 31(6), 549 - 52 {A case of late onset group B streptococcus meningitis with transient oculomotor nerve palsy}; Murakami K; I report here a case of late onset Group B Streptococcus (GBS) meningitis with transient oculomotor nerve palsy . The boy was admitted to our hospital at 25 days of age . On the 5th hospital day, he was found to be unable to open the left eye . Although light reflex of both the eyes was intact, the left eye was deviated to the left lateral side . We administered intravenously steroid hormone and antibiotics . His eye movements were normalized on the 30th hospital day . Oculomotor nerve palsy in this case may have been caused by vasculitis of the middle cerebral artery . This case shows that steroid hormone is effective for vascular edema complicating neonatal meningitis. FEMS Microbiol Lett, 1999 Dec 1, 181(1), 113 - 21 Hybridization analysis of the gene encoding a hemolysin (suilysin) of Streptococcus suis type 2: evidence for the absence of the gene in some isolates; Okwumabua O et al.; A hemolysin gene was cloned from a virulent strain of Streptococcus suis type 2 strain 1933 . Analysis of the gene and its product revealed that it is identical to a previously reported hemolysin (suilysin) of S . suis type 2 . Southern hybridization analysis of the digested total genomic DNA from S . suis with the cloned hemolysin DNA sequences as probe indicated that the hemolysin gene is present as a single copy on the genome . Genomic DNA of 63 isolates of S . suis encompassing all known serotypes were examined by DNA hybridization and polymerase chain reaction (PCR) studies for the presence of the hemolysin gene homolog . The results of both techniques were identical and demonstrated the absence of the hemolysin gene in some isolates . In DNA hybridization studies, three DNA probes derived from the hemolysin encoding gene were used . Results showed that sequences encoding the C-terminal 257 amino acid residues (Probe 1) were the most conserved and hybridized to a 1.2 kb fragment in 32 (51%) strains and a 4.0 kb fragment in 23 (36%) strains respectively . Thus, Probe 2 hybridized to the DNA of 55 (87%) of the isolates tested . The first probe (Probe 1) comprising almost the entire hemolysin gene and the third probe (Probe 3) which consisted of the N-terminal sequences hybridized only to a 4.0 kb fragment in 23 (36%) of the strains tested . Eight (13%) of the strains tested were hybridization and PCR negative . The hybridization of the C-terminal end sequences (Probe 2) to the 1.2 kb fragment in 32 (51%) of the strains and the lack of hybridization of the probes to eight (13%) strains may suggest the presence of different types of hemolysin molecule in S . suis strains. Brain Res, 1999 Nov 13, 847(1), 143 - 8 Hypothermia decreases excitatory neurotransmitter release in bacterial meningitis in rabbits; Irazuzta JE et al.; The excitatory neurotransmitters glutamate (GLU) and aspartate (ASP) are involved in the pathogenesis of neuronal injury in meningitis . Based on past findings that the induction of moderate hypothermia (32-34 degrees C) attenuates the release of GLU in ischemic brain injury, this study was designed to detect if the application of moderate hypothermia decreases the release of excitatory amino acids (EAA) from brain tissue of animals with bacterial meningitis . Also examined was whether meningitis induces the expression of 72-kDa heat shock protein (HSP 70) in the cerebellum and how hypothermia affects it, for induction of HSP 70 has been used as a sensitive marker of neuronal stress in other forms of brain injury . Meningitis was induced by injecting Group B Streptococcus (GBS) into the cisterna magnae of rabbits . Antibiotic treatment began 16 h later . At this time the animals were anesthetized, instrumented, and randomized to normothermic (Nor) or hypothermic (Hy) conditions . Temperatures were strictly regimented for the following 10 h while maintaining stable cardiorespiratory parameters . Cerebrospinal fluid (CSF) samples were then withdrawn to measure concentrations of bacteria, protein, and amino acids . Meningitis causes CSF contents of GLU and ASP to increase significantly . Hypothermia treated animals demonstrated a 40-50% reduction in CSF GLU and ASP . Meningitis induced the expression of HSP 70 in the cerebellum while hypothermic animals experienced a significant decrease HSP 70 induction . These data demonstrate that hypothermia produces an attenuation of the release of excitatory neurotransmitters in meningitis and suggest that this treatment may attenuate neuronal stress. Int J Antimicrob Agents, 1999 Sep, 13(1), 29 - 33 Prevalence of mefE, erm and tet(M) genes in Streptococcus pneumoniae strains from Central Italy; Latini L et al.; One hundred and seventy-three Streptococcus pneumoniae strains isolated from surveillance studies conducted in daycare centres were studied . The mefE, erm and tet(M) genes were detected in 16.2, 45.1 and 47.4% of isolates respectively . Agreement between PCR results and antibiotic susceptibility patterns was 100% . Macrolide resistance was due to the presence of erm in 73.6% of strains and to the presence of mefE in the remaining 26.4% . All tetracycline resistant strains carried the tet(M) gene . erm was associated with tet(M) in 98.7% of strains, whereas no isolate carrying mefE carried tet(M) . A significant association was found between mefE and serogroup 6 (P < 0.0005) and between erm and tet(M) and serogroup 19 (P < 0.00001). Pharmazie, 1999 Oct, 54(10), 772 - 5 Antimicrobial activity of selected cyclic dipeptides; Graz M et al.; Cyclic dipeptides are products of rational drug design, which may exhibit both antimicrobial and antitumor properties . The aim of this study was to investigate both the antimicrobial effects of the cyclic dipeptides cyclo(L-phenylalanyl-L-prolyl), cyclo(L-tyrosyl-L-prolyl), cyclo(L-tryptophanyl-L-prolyl) and cyclo(L-tryptophanyl-L-tryptophanyl) and the effects of these cyclic dipeptides on the gastrointestinal epithelium in vitro . Furthermore, a relevant solvent for the possible pharmaceutical application of the products was sought concurrently . The antimicrobial effect of the cyclic dipeptides was assayed using the Kirby-Bauer disc diffusion assay against Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, Bacillus subtilis, Streptococcus pneumoniae, Candida albicans, Aspergillus niger and Penicillium notatum . The effect of the cyclic dipeptides on the gastrointestinal epithelium was assessed by changes in alkaline phosphatase expression of HT-29 cells . Cyclo(Pro-Trp) and cyclo(Phe-Pro) show broad spectrum antibacterial properties and cyclo(Trp-Pro) and cyclo(Trp-Trp) show broad spectrum antifungal properties . The maturation of the gastrointestinal cells was enhanced by cyclo(Phe-Pro), cyclo(Tyr-Pro), cyclo(Trp-Trp) and cyclo(Trp-Pro) . The activity of these cyclic dipeptides thus indicates potential application of these compounds as pharmacological agents. Enferm Infecc Microbiol Clin, 1999 Oct, 17(8), 394 - 7 {Eikenella corrodens: five year experience in a general hospital}; Gasser I et al.; BACKGROUND: Eikenella corrodens is a Gram negative bacillus that colonizes oropharyngeal and digestive mucous membranes . It is difficult to isolate in the laboratory . This might be the reason why its implication in different types of infection is not well known . We report a five year experience in a general hospital . METHODS: Charts of 125 infections have been retrospectively reviewed . No selective medium was employed for the isolation . RESULTS: Infections were related to oral cavity in 68 patients (54%) and to gastrointestinal tract in 45 (36%); in 12 no clear source could be found . The prevailing infections were: postsurgical 32, apendiceal 22, abscesses 22, and traumatic wounds 12 . Seventy two percent of the patients were adults and 93% were hospitalized . Eighteen patients had a neoplasia, 6 were diabetic, and 3 had some kind of immunodeficiency . Etiology was polymicrobial in 91% of the cases, the prevailing association being with Streptococcus spp . (74%) . Only 15 patients had a pure culture, 11 of which had received previous antibiotic treatment . The most serious infections were a subdural empyema secondary to sinusitis, a mediastinitis following a mouth floor abscess, and a peritonitis with pleural empyema preceded by an hepatic abscess . The three were polymicrobial . Outcome was always satisfactory with no associated death . CONCLUSIONS: The origin of these infections is almost always clearly related with its habitat, but their spectrum is wide . Polymicrobial condition of most of them makes diagnosis as well as interpretation of its clinical meaning difficult . Nevertheless, association of E . corrodens with serious or slow healing infections fully justifies the efforts towards its isolation and the choice of antibiotics to which it is susceptible. J Med Assoc Thai, 1999 Sep, 82(9), 922 - 4 Streptococcus suis meningitis: report of a case; Chotmongkol V et al.; A 50-year-old policeman who presented with subacute meningitis, bilateral rectus muscle palsies, dizziness and early bilateral deafness was reported . Cerebrospinal fluid (CSF) revealed polymorphonuclear pleocytosis with Gram-positive cocci . Blood and CSF cultures grew Streptococcus viridans which subsequently identified to be Streptococcus suis . The patient improved after treatment but deafness persisted. Mol Microbiol, 1999 Nov, 34(3), 596 - 606 Identification and characterization of a Streptococcus pyogenes ABC transporter with multiple specificity for metal cations; Janulczyk R et al.; Metal ions are crucial trace elements for bacteria infecting the human host . The LraI (lipoprotein receptor-associated antigen I) transporter in Streptococcus spp . belongs to the superfamily of ABC transporters . The transporter consists of a lipoprotein, an ATP-binding protein and a hydrophobic integral membrane protein . Here, we describe a new member of the LraI family in the important human pathogen Streptococcus pyogenes . The system was identified in silico by analysis of the S . pyogenes Genome Sequencing Project . The S . pyogenes operon exhibits an atypical organization compared with equivalents in other Streptococcus spp . The presence and atypical organization of the operon was verified in a number of S . pyogenes strains of different serotypes . Transcriptional analysis of the LraI operon demonstrates a polycistronic transcription attenuated by a stable stem-loop structure, which allows the lipoprotein to be expressed in larger quantities than the other two components . The localization of the native lipoprotein at the bacterial surface was shown by proteolytic digestion of S . pyogenes bacteria and NH2-terminal sequencing of a released lipoprotein fragment . Recombinant lipoprotein was expressed as a GST fusion protein, and studies of molecular interactions with metal radioisotopes demonstrated that the protein has affinity for Zn(II), Fe(III) and Cu(II) . Zn(II) and Cu(II) were found to compete for the same binding site, whereas Fe(III) uses a second site . Also, proton-induced X-ray analysis of lipoprotein samples identified iron, copper and zinc . Finally, a mutant strain lacking a functional mtsABC operon was generated and showed reduced uptake of 55Fe and 65Zn compared with the wild-type strain . The operon encoding this novel ABC transporter with multiple specificity for metal cations is designated mtsABC, for metal transporter of Streptococcus. Am J Obstet Gynecol, 1999 Nov, 181(5 Pt 1), 1243 - 9 The capture rate of at-risk term newborns for early-onset group B streptococcal sepsis determined by a risk factor approach; Towers CV et al.; OBJECTIVE: Currently, the Centers for Disease Control and Prevention, The American College of Obstetricians and Gynecologists, and the American Academy of Pediatrics recommend that health care providers for pregnant women implement 1 of 2 strategies for the potential prevention of early-onset neonatal group B streptococcal sepsis . Both algorithms recommend intrapartum antibiotic chemoprophylaxis for patients delivered of their neonates at <37 weeks' gestation . The basic difference lies in the management of the term pregnancy . One protocol suggests treatment of all patients with term pregnancies with a positive culture for group B Streptococcus obtained at 35 to 37 weeks' gestation . The second approach recommends treatment on the basis of risk factors of membrane rupture of >/=18 hours' duration or intrapartum temperature of >/=38 degrees C . The capture rate of at-risk neonates determined by the risk factor strategy is quoted as being approximately 70%; however, the basis for this percentage was from studies that used slightly different definitions than the current guidelines and never separated the term from the preterm newborn . Our objective was to prospectively collect every case of blood culture-proven early-onset neonatal group B streptococcal sepsis and determine whether risk factors, as currently defined, were present that might have warranted maternal intrapartum antibiotic chemoprophylaxis . STUDY DESIGN: A prospective study was initiated on July 1, 1987, and completed on December 31, 1996 . Every patient that was delivered of a neonate in whom early-onset group B streptococcal sepsis developed was analyzed in detail for possible intrapartum risk factors . RESULTS: A total of 49 cases of early-onset group B streptococcal sepsis occurred in 46,959 deliveries . Of these 49 newborns, 9 (18%) were delivered at <37 weeks' gestation . The remaining 40 newborns were delivered at term, and only 12 (30%) were delivered with an intrapartum risk factor of either membrane rupture of >/=18 hours' duration or temperature of >/=38 degrees C or both . CONCLUSIONS: On the basis of the data from this study and the current literature, the risk factor approach with the current guideline recommendations would capture <50% of the term newborns in whom sepsis develops. Am J Obstet Gynecol, 1999 Nov, 181(5 Pt 1), 1197 - 202 Incidence of intrapartum maternal risk factors for identifying neonates at risk for early-onset group B streptococcal sepsis: A prospective study; Towers CV et al.; OBJECTIVE: In mid-1996 and early 1997, the Centers for Disease Control and Prevention, The American College of Obstetricians and Gynecologists, and the American Academy of Pediatrics all published guidelines outlining 2 potential strategies for the purpose of preventing neonatal sepsis caused by group B Streptococcus . One of these approaches involves treating pregnant women intrapartum with antibiotics if any of the following risk factors develop: delivery at <37 weeks' gestation, membrane rupture for >/=18 hours' duration, or temperature during labor of >/=38 degrees C . However, to date there have been no population-based studies that have ascertained the percentage of pregnant women eligible to receive intrapartum antibiotic chemoprophylaxis if these risk factors were used . Our objective was to perform a large patient-based study at >1 institution evaluating all deliveries for the presence of maternal risk factors by using the definitions of the current guidelines . STUDY DESIGN: A prospective cohort study was initiated in 1995 at 3 private community hospitals and 1 private referral center . The study population was composed of 5410 consecutively delivered patients from the 4 different hospitals . Every pregnancy was analyzed for gestational age at delivery, duration of membrane rupture, temperature during labor, and use of intrapartum antibiotic chemoprophylaxis . RESULTS: Of the 5410 patients, a total of 455 (8 . 4%) were delivered of their neonates before 37 weeks' gestation, 421 (7.8%) had rupture of membranes for at least 18 hours' duration, and 378 (7.0%) had an intrapartum temperature of >/=38 degrees C . Overall, 1071 pregnant women (19.8% of the population studied) had >/=1 of the defined risk factors . CONCLUSIONS: These data suggest that, if the current risk factor strategy is used, 19.8% of the delivering population would potentially be candidates for intrapartum antibiotic chemoprophylaxis. J Bacteriol, 1999 Nov, 181(22), 6914 - 21 Phenotypic consequences resulting from a methionine-to-valine substitution at position 48 in the HPr protein of Streptococcus salivarius; Plamondon P et al.; In gram-positive bacteria, the HPr protein of the phosphoenolpyruvate:sugar phosphotransferase system (PTS) can be phosphorylated on a histidine residue at position 15 (His(15)) by enzyme I (EI) of the PTS and on a serine residue at position 46 (Ser(46)) by an ATP-dependent protein kinase (His approximately P and Ser-P, respectively) . We have isolated from Streptococcus salivarius ATCC 25975, by independent selection from separate cultures, two spontaneous mutants (Ga3.78 and Ga3.14) that possess a missense mutation in ptsH (the gene encoding HPr) replacing the methionine at position 48 by a valine . The mutation did not prevent the phosphorylation of HPr at His(15) by EI nor the phosphorylation at Ser(46) by the ATP-dependent HPr kinase . The levels of HPr(Ser-P) in glucose-grown cells of the parental and mutant Ga3.78 were virtually the same . However, mutant cells growing on glucose produced two- to threefold less HPr(Ser-P)(His approximately P) than the wild-type strain, while the levels of free HPr and HPr(His approximately P) were increased 18- and 3-fold, respectively . The mutants grew as well as the wild-type strain on PTS sugars (glucose, fructose, and mannose) and on the non-PTS sugars lactose and melibiose . However, the growth rate of both mutants on galactose, also a non-PTS sugar, decreased rapidly with time . The M48V substitution had only a minor effect on the repression of alpha-galactosidase, beta-galactosidase, and galactokinase by glucose, but this mutation abolished diauxie by rendering cells unable to prevent the catabolism of a non-PTS sugar (lactose, galactose, and melibiose) when glucose was available . The results suggested that the capacity of the wild-type cells to preferentially metabolize glucose over non-PTS sugars resulted mainly from inhibition of the catabolism of these secondary energy sources via a HPr-dependent mechanism . This mechanism was activated following glucose but not lactose metabolism, and it did not involve HPr(Ser-P) as the only regulatory molecule. Chest, 1999 Nov, 116(5), 1278 - 81 The impact of blood cultures on antibiotic therapy in pneumococcal pneumonia; Waterer GW et al.; INTRODUCTION: The cost-effectiveness of blood cultures in community-acquired pneumonia (CAP) has been questioned . Although penicillin-resistant Streptococcus pneumoniae is an increasing problem, penicillin therapy, where appropriate, reduces cost and may reduce antibiotic resistance . Blood cultures, however, can only reduce cost if physicians are prepared to alter therapy based on the results . We reviewed our experience to determine how often physicians changed management based on blood culture results positive for S pneumoniae . METHODS: Retrospective chart review was performed of all CAP admissions between January 1996 and December 1998 with blood culture results positive for S pneumoniae . RESULTS: Seventy-four patients out of 1,805 patients admitted with CAP during this period had pneumococcemia . Penicillin resistance was identified in 15 cases (20.3%; high grade in 4 cases) with cephalosporin resistance in 4 of these cases (1 high grade) . Fifty-one patients had initial empiric therapy with a third-generation cephalosporin, and 58 patients had empiric coverage of atypical organisms; no patient received empiric penicillin therapy . Blood culture results altered management in 31 patients (41.9%), but in only 2 cases was this due to antibiotic resistance . Fifty-one patients without penicillin allergy grew penicillin-sensitive pneumococci; only 11 patients (21.6%) were changed to penicillin therapy . Thirteen of 35 patients (37.1%) who were given an additional antibiotic for atypical coverage had this antibiotic ceased . CONCLUSION: Despite evidence of penicillin-sensitive pneumococcal CAP, physicians were reluctant to narrow antibiotic therapy, potentially adding to treatment cost and reducing the impact of blood culture results on management . The impact of penicillin resistance was reduced by the usual empiric choice of a third-generation cephalosporin . While positive blood culture results can clearly be useful in the management of patients with CAP, their cost-effectiveness needs to be assessed in prospective clinical trials. Chin J Dent Res, 1998 Sep, 1(2), 37 - 40 Reversed-phase high-performance liquid chromatographic measurement of the P-aminobenzoic acid synthesized by Streptococcus sanguis; Zhou XD et al.; OBJECTIVE: This study investigated the biosynthesis of P-aminobenzoic acid by Streptococcus sanguis and the role of P-aminobenzoic acid in the interaction between Streptococcus sanguis and Streptococcus mutans . METHODS: A reversed-phase high-performance liquid chromatographic technique was used to analyze the P-aminobenzoic acid synthesized by Streptococcus sanguis in an anaerobic atmosphere . RESULTS: The results showed, that (1) the chromatographic method established in this study had good linear relation and the average recovery of P-aminobenzoic acid was 80%, and (2) Streptococcus sanguis did synthesize P-aminobenzoic acid, and the mean concentration of P-aminobenzoic acid was 1.23 micrograms/mL . CONCLUSIONS: The results of this study will help further studies of the factors that may have effects on P-aminobenzoic acid synthesis by Streptococcus sanguis and on the role of P-aminobenzoic acid in the microbial homeostasis of dental plaque. Chin J Dent Res, 1999 Feb, 2(1), 12 - 5 Effects of monoclonal antibody on colonization of Streptococcus sobrinus and development of dental caries in rats; Zhang P et al.; OBJECTIVE: To investigate the effect of local application of monoclonal antibody (McAb) raised against the 210KD cell surface protein antigen (PAg) of Streptococcus sobrinus on the colonization of rats' teeth and the development of dental caries . MATERIALS AND METHODS: Thirty Wistar rats were divided into 3 groups: group 1 received McAb against PAg; group 2 received unrelated mice ascites; group 3 received pure buffered saline . The bacteria were applied 6 times to the occlusal surfaces of molars and to the labial surfaces of incisors . After three applications, streptomycin-resistant S . sobrinus 6715 was applied to the teeth and the rats were fed with caries-inducing diet 2000 . The number of colonized S . sobrinus was counted on the streptomycin-supplemented mutans streptocci agar and expressed as a percentage of the total colonies on BHI agar . The presence of caries was examined and scored following Keyes' procedure . RESULTS: There were significantly lower levels of colonization by S . sobrinus on rats' teeth and lower mean caries scores on the teeth treated with McAb compared with those in the control groups . CONCLUSION: Local passive immunization with McAb against PAg may be an effective way to prevent colonization by implanted S . sobrinus and development of dental caries. Chin J Dent Res, 1998 Dec, 1(3), 52 - 5 The relationship between caries activity and the status of dental caries--application of the Dentocult SM method; Shi S et al.; OBJECTIVE: To study the relationship between caries activity and the status of dental caries in preschool children using a caries activity test (CAT) . MATERIALS AND METHODS: The status of primary tooth caries in 229 children ages 3 to 5 was examined . Caries incidence, DFT, and caries severity index (CSI) were calculated . Based on the quantity of Streptococcus mutans in the oral cavity detected with Dentocult SM, a caries activity test, four grades of caries activity were classified: Grade 0 (< 10(4) colony-forming units/mL), Grade I (10(4)-10(5) CFU/mL), Grade II (10(5)-10(6) CFU/mL), and Grade III (> 10(6) CFU/mL) . RESULTS: The results showed that 79.48% children had Grade I or higher caries severity . Significant differences of caries activity were found among different grades, which were highly correlated with caries incidence, DFT, and CSI (r = 0.22216, 0.31212, and 0.32276, respectively) . CONCLUSIONS: As a CAT, Dentocult SM is a reliable method for measuring the status of dental caries in preschool children . It is also a valuable tool in the prevention and treatment of dental caries. Pharmacotherapy, 1999 Nov, 19(11), 1308 - 14 In vitro activity and pharmacodynamics of oral beta-lactam antibiotics against Streptococcus pneumoniae from southeast Missouri; Kays MB et al.; STUDY OBJECTIVES: To determine the frequency of reduced susceptibility to penicillin, and to compare the in vitro activity and pharmacodynamics of oral beta-lactam antibiotics against clinical isolates of Streptococcus pneumoniae from southeast Missouri . SETTING: Cape Girardeau, Missouri (population 35,500) . Interventions . Minimum inhibitory concentrations (MICs) were determined for penicillin, amoxicillin, amoxicillin-clavulanic acid, cefprozil, cefuroxime, cefpodoxime, cefaclor, and loracarbef by E test for 108 isolates of S . pneumoniae . The MIC50, MIC90, and percentage susceptibility were calculated for each agent . Pharmacokinetic variables were obtained from the literature, and serum concentration-time profiles were simulated for a 25-kg child taking pediatric dosages commonly administered to treat otitis media . The average time above MIC (T > MIC) was calculated as percentage of the dosing interval using free concentrations and the MIC for each individual isolate . Analysis of variance (Scheffe post hoc test) was used to determine differences among agents for in vitro activity and T > MIC (level of significance, p<0.05) . MEASUREMENTS AND MAIN RESULTS: The frequency of penicillin-nonsusceptible S . pneumoniae was 28.7% (31/108) . For 25 penicillin-intermediate isolates, amoxicillin and amoxicillin-clavulanic acid were significantly more active than cefprozil, cefaclor, and loracarbef . The T > MIC for amoxicillin and amoxicillin-clavulanic acid, simulated at 13.3 mg/kg every 8 hours, was significantly longer than that for all other beta-lactams . CONCLUSION: Amoxicillin and amoxicillin-clavulanic acid have superior in vitro activity and longer T > MIC for penicillin-intermediate isolates than the other oral beta-lactams. CLAO J, 1999 Oct, 25(4), 200 - 3 Corneal ulcers and the use of topical fluoroquinolones; Honig MA et al.; PURPOSE: To determine whether the widespread use of topical fluoroquinolones has changed the spectrum of ulcerative keratitis, and to determine how it has affected practice patterns in the treatment of corneal ulcers . METHODS: We retrospectively reviewed the charts of 48 consecutive patients with infectious corneal ulcers from 7/1/91 to 12/31/91 and 47 consecutive patients from 7/1/94 to 12/31/94 . Patients were treated with intensive topical antibiotics (either standard fortified antibiotics or topical fluoroquinolones) at a frequency of at least every hour while awake . Some patients were admitted to the hospital, and some underwent scraping for smears and cultures . RESULTS: Ulcers which were seen in 1994 appear to have been more severe than those seen in 1991 as judged by the presence of more ulcers associated with hypopyons, (P< 0.05) but not with regard to the size of the infiltrate or epithelial defect . More ulcers in 1994 were treated on an outpatient basis (P< 0.02) and fewer ulcers were scraped and cultured than in 1991 (P< 0.001) . Culture results from the 1991 and 1994 groups were similar . The most frequently isolated organisms were coagulase-negative Staphylococcus, Pseudomonas, Staphylococcus aureus, and Streptococcus spp . CONCLUSION: The spectrum of ulcerative keratitis at a tertiary referral center may be showing a trend towards more severe ulcers, but the causative agents responsible for the infection are unchanged. Arch Otolaryngol Head Neck Surg, 1999 Nov, 125(11), 1262 - 6 Sinogenic subdural empyema and Streptococcus anginosus; Hutchin ME et al.; Subdural empyema (SDE) is most commonly caused by sinusitis and, without early diagnosis and neurosurgical intervention, is associated with high mortality . In a patient with sinusitis who presents with mental status changes, the diagnosis of SDE should be suspected on clinical grounds, even in the absence of significant computed tomographic findings . Computed tomography with contrast is a useful aid in the diagnosis of SDE, but findings may be subtle, and contrasted magnetic resonance imaging is superior . The association of Streptococcus anginosus sinusitis and related intracranial sequelae is important owing to the potentially catastrophic complications and should be recognized by otolaryngologists . In view of the rapidly progressing nature of sinogenic SDE, physicians should strongly consider early institution of aggressive therapy consisting of craniotomy with concurrent sinus drainage in patients in whom sinogenic SDE is suspected on clinical grounds, particularly in the presence of S . anginosus-positive sinus cultures. New Microbiol, 1999 Oct, 22(4), 383 - 7 Molecular characterization of Streptococcus equi subspecies equi isolated from an Ethiopian camel by ribotyping and PCR-ribotyping; Sechi LA et al.; The aim of this study was to characterize a S . equi subspecies equi strain isolated from an Ethiopian camel by different molecular techniques (Ribotyping and PCR-Ribotyping) . We compared the results obtained with those generated from two strains of the Pasteur Collection . The ribotyping showed the highest power of differentiation, distinguishing between the strains analyzed, whereas PCR-Ribotyping was able only to differentiate the camel isolate but not the strains from the Pasteur Collection . The application of this technique will be very useful to establish a clonal relationship among equine and camelids strains and help the prevention and cure of the equine and camel pathology. Nippon Jibiinkoka Gakkai Kaiho, 1999 Sep, 102(9), 1036 - 41 {Acute otitis media associated with bone conduction hearing loss}; Ikui A et al.; Eleven patients (12 ears) with acute otitis media associated with raised bone conduction were studied . The patients were from 19 to 70 years old and came to our hospital between November 1996 through May 1997 . Pure tone audiometry revealed mixed hearing loss, but there was no bullous myringitis in all cases . They were treated by oral or intravenous antibiotics, steroids, and myringotomy . Bacteriological examination was done in seven cases, and revealed penicillin resistant Streptococcus pnumoniae in three cases . Complete recovery of hearing loss was obtained in 10 of 12 ears, but sensorineural hearing loss remained in 2 patients . Bacteriological examination and pure tone audiometry in acute otitis media are important for detecting the severity of the disease, determining the administration of steroids, and for the selection of antibiotics. Oral Microbiol Immunol, 1999 Aug, 14(4), 233 - 7 A DNA probe specific to Streptococcus sobrinus; Ida H et al.; Three DNA fragments (SSB-1, -2 and -3) in the dextranase gene (dex) of Streptococcus sobrinus were amplified by polymerase chain reaction and used as DNA probes . The probes were examined for the specificity and the sensitivity of hybridization with DNA of oral streptococcal species . While probes SSB-1 and SSB-2 were specific to both S . sobrinus and Streptococcus downei, SSB-3 was specific only to S . sobrinus . SSB-3 was able to detect 5 ng of chromosomal DNA purified from S . sobrinus NIDR6715 and DNA extracted from 1 x 10(5) cells of the strain . In addition, SSB-3 could differentiate clinical isolates of S . sobrinus from Streptococcus mutans . These results suggest that SSB-3 is an effective DNA-probe to detect and to identify S . sobrinus. Oral Microbiol Immunol, 1999 Aug, 14(4), 225 - 32 Physical and genetic map of Streptococcus mutans GS-5 and localization of five rRNA operons; Cappiello MG et al.; The physical map of the 2.1 megabase chromosome of Streptococcus mutans GS-5 has been refined by including all ApaI and SmaI fragments of 5 kbp or greater, and by positioning the fragments generated by the endonuclease I-CeuI . Sixty-three new genetic loci have been added to the map, so that it now contains 90 loci . The new loci include those for 35 cloned streptococcal genes of established function and for 23 S . mutans genes of putative function . In addition, five rrn operons were identified and placed on the map of the chromosome . The presence of a SmaI site in each of the rrn operons allowed the direction of transcription of each operon to be deduced . The orientation of the rrn loci indicates that their transcription is directed away from a small region of the chromosome, identifying a possible region for the initiation of chromosome replication. Oral Microbiol Immunol, 1999 Aug, 14(4), 213 - 9 The immunogenicity of various peptide antigens inducing cross-reacting antibodies to a cell surface protein antigen of Streptococcus mutans; Kato H et al.; A cell surface protein antigen (PAc) of Streptococcus mutans may be involved in the binding of bacteria to the tooth surface, and has long been focused upon as a candidate for a preventive vaccine of dental caries . Previously the peptide PAc (365-377) was shown to raise an antibody in B10.D2 mice which inhibited the binding of salivary components to the PAc molecule . Using this peptide as a unit peptide, two constructs based on multiple antigenic peptides, and several types of tandem repeats of two or three copies were synthesized to estimate the immunogenicity of these peptides . Increase in the immunogenicity was observed for all constructs with the use of an adjuvant compared to the unit peptide alone . However, the tandem repeat constructs generally induced antibody production in the absence of adjuvant, while the multiple antigenic peptide constructs did not induce antibody production under the same condition . Although such a phenomenon may be restricted to this particular peptide sequence, these results may influence the strategy for the design of peptide vaccines. Clin Diagn Lab Immunol, 1999 Nov, 6(6), 986 - 8 bca, beta gene, and gene product divergency in reference and prototype strains of streptococcus agalactiae; Maeland JA et al.; Reference and prototype strains of Streptococcus agalactiae (GBS) were originally selected on the basis of phenotypic traits which, however, do not always mirror genotypic traits . A total of 14 reference and prototype GBS strains were examined by PCR designed to detect the bca and beta genes, encoding the c proteins c(alpha) and c(beta), respectively . The cognate proteins were detected by whole-cell-based fluorescent antibody testing and Western blotting . The PCR for beta gene detection and the antibody-based c(beta) protein detection showed concordant results with all of the isolates, whereas 7 of 14 strains which did not express c(alpha) protein at detectable levels contained bca gene elements, consistent with bca gene and gene product divergency in these strains . The results emphasize the importance of genetic characterization of reference and prototype strains of GBS which, in the past, have been selected on the basis of phenotypic traits. Biochem J, 1999 Nov 15, 344 Pt 1, 259 - 64 Mutation of aspartic acid residues in the fructosyltransferase of Streptococcus salivarius ATCC 25975; Song DD et al.; The site-directed mutated fructosyltransferases (Ftfs) of Streptococcus salivarius ATCC 25975, D312E, D312S, D312N and D312K were all active at 37 degrees C, indicating that Asp-312 present in the 'sucrose box' was not the nucleophilic Asp residue responsible for the formation of a covalent fructosyl-enzyme intermediate required for enzyme activity . Analysis of the kinetic constants of the purified mutated forms of the enzyme showed that Asp-312 was most likely an essential amino acid involved in determining acceptor recognition and/or stabilizing a beta-turn in the protein . In contrast, when the Asp-397 of the Ftf present in the conserved triplet RDP motif of all 60 bacterial and plant family-32 glycosylhydrolases was mutated to a Ser residue, both sucrose hydrolysis and polymerization ceased . Tryptophan emission spectra confirmed that this mutation did not alter protein structure . Comparison of published data from other site-directed mutated enzymes implicated the Asp residue in the RDP motif as the one that may form a transient covalent fructosyl intermediate during the catalysis of sucrose by the Ftf of S . salivarius. J Mol Biol, 1999 Nov 12, 293(5), 1145 - 60 Studies on the structure and mechanism of a bacterial protein toxin by analytical ultracentrifugation and small-angle neutron scattering; Gilbert RJ et al.; Pneumolysin, an important virulence factor of the human pathogen Streptococcus pneumoniae, is a pore-forming toxin which also possesses the ability to activate the complement system directly . Pneumolysin binds to cholesterol in cell membrane surfaces as a prelude to pore formation, which involves the oligomerization of the protein . Two important aspects of the pore-forming activity of pneumolysin are therefore the effect of the toxin on bilayer membrane structure and the nature of the self-association into oligomers undergone by it . We have used analytical ultracentrifugation (AUC) to investigate oligomerization and small-angle neutron scattering (SANS) to investigate the changes in membrane structure accompanying pore formation.Pneumolysin self-associates in solution to form oligomeric structures apparently similar to those which appear on the membrane coincident with pore formation . It has previously been demonstrated by us using site-specific chemical derivatization of the protein that the self-interaction preceding oligomerization involves its C-terminal domain . The AUC experiments described here involved pneumolysin toxoids harbouring mutations in different domains, and support our previous conclusions that self-interaction via the C-terminal domain leads to oligomerization and that this may be related to the mechanism by which pneumolysin activates the complement system.SANS data at a variety of neutron contrasts were obtained from liposomes used as model cell membranes in the absence of pneumolysin, and following the addition of toxin at a number of concentrations . These experiments were designed to allow visualization of the effect that pneumolysin has on bilayer membrane structure resulting from oligomerization into a pore-forming complex . The structure of the liposomal membrane alone and following addition of pneumolysin was calculated by the fitting of scattering equations directly to the scattering curves . The fitting equations describe scattering from simple three-dimensional scattering volume models for the structures present in the sample, whose dimensions were varied iteratively within the fitting program . The overall trend was a thinning of the liposome surface on toxin attack, which was countered by the formation of localized structures thicker than the liposome bilayer itself, in a manner dependent on pneumolysin concentration . At the neutron contrast match point of the liposomes, pneumolysin oligomers were observed . Inactive toxin appeared to bind to the liposome but not to cause membrane alteration; subsequent activation of pneumolysin in situ brought about changes in liposome structure similar to those seen in the presence of active toxin . We propose that the changes in membrane structure on toxin attack which we have observed are related to the mechanism by which pneumolysin forms pores and provide an important perspective on protein/membrane interactions in general . We discuss these results in the light of published data concerning the interaction of gramicidin with bilayers and the hydrophobic mismatch effect . Nurse Pract, 1999 Oct, 24(10 Suppl), 1 - 9; quiz 15-6 Acute otitis media: management and surveillance in an era of pneumococcal resistance . Drug-Resistant Streptococcus Pneumoniae Therapeutic Working Group; Dowell SF et al.; Experts in the management of otitis media and the Drug-resistant Streptococcus pneumoniae Therapeutic Working Group were convened by the Centers for Disease Control and Prevention to respond to changes in antimicrobial susceptibility among pneumococci . The objective was to provide consensus recommendations for the management of acute otitis media (AOM) and for the surveillance of drug-resistant Streptococcus pneumoniae . After summarizing published and unpublished data from the scientific literature and the experience of the panel members, the group concluded that oral amoxicillin should remain the first-line antimicrobial agent for treating AOM . For patients with clinically defined treatment failure after 3 days of therapy, useful alternative agents include amoxicillin-clavulanate, cefuroxime axetil, and intramuscular ceftriaxone . The group also made recommendations to improve surveillance and to obtain antimicrobial susceptibility patterns for local geographic areas. Postepy Hig Med Dosw, 1999, 53(4), 545 - 59 {Molecular mimicry of bacteria as a factor in bacterial pathogenicity}; Witkowska D; Structural and functional homology between bacterial proteins and host antigens, called molecular mimicry, is considered as significant pathogenic factor involved in several autoimmune diseases . The most important examples of this phenomenon reviewed in this work, involve rheumatic fever, Graves' disease, ankylosing spondylitis, Reiter's syndrome and rheumatic arthritis caused by infections with Streptococcus, Yersinia, Klebsiella, Escherichia coli, respectively. J Nat Prod, 1999 Oct, 62(10), 1379 - 84 Activity of triterpenoid glycosides from the root bark of Mussaenda macrophylla against two oral pathogens; Kim NC et al.; Four new triterpenoid glycosides were isolated from the root bark of Mussaenda macrophylla . Their structures were determined as 3-O-beta-D-glucopyranosyl-28-O-alpha-L-rhamnopyranosyl-16alpha- hydrox y-23-deoxyprotobassic acid (1), 28-O-beta-D-glucopyranosyl-16alpha-hydroxy-23-deoxyprotobassic+ ++ acid (2), 3-O-beta-D-glucopyranosyl-28-O-alpha-L-rhamnopyranosyl-16alpha- hydrox yprotobassic acid (3), and 3-O- inverted question mark{beta-D-glucopyranosyl-(1-->6)}-O-alpha-L-rhamnopyranosyl-(1-->2 )-O-beta-D-glucopyranosyl-(1-->2) inverted question mark-O-beta-D-glucopyranosyl-(1-->3)-O- beta-D-glucopyranosyl-cycloarta-22,24-dien-27-oic acid (mussaendoside W, 4) . Four known triterpenoids {3-O-acetyloleanolic acid (5), 3-O-acetyldaturadiol (6), rotundic acid (7), and 16alpha-hydroxyprotobassic acid (8)} were also isolated . The structures of 1-4 were determined by several spectroscopic techniques including 2D NMR methods . Compounds 1-6 showed inhibitory activity against a periodontopathic bacterium, Porphyromonas gingivalis, but were inactive against the cariogenic organism, Streptococcus mutans. Antimicrob Agents Chemother, 1999 Nov, 43(11), 2793 - 7 Pharmacokinetics of a once-daily oral dose of moxifloxacin (Bay 12-8039), a new enantiomerically pure 8-methoxy quinolone; Sullivan JT et al.; The pharmacokinetics, safety, and tolerability of oral moxifloxacin, a new 8-methoxy quinolone, were assessed in a randomized, double-blind, placebo-controlled study in which healthy male and female volunteers received either 400 mg of moxifloxacin once daily (n = 10) or a placebo once daily (n = 5) for 10 days . Plasma moxifloxacin concentrations on days 1 and 10 were measured by high-performance liquid chromatography and fluorometric detection . Standard pharmacokinetic parameters were estimated by noncompartmental methods . Natural logarithmic estimates for each pharmacokinetic variable of each subject were analyzed by a two-way analysis of variance . Hematology, blood chemistry, vital signs, and adverse events were monitored, and electrocardiograms (ECG) were performed . Plasma moxifloxacin concentrations of predicted therapeutic relevance were achieved in this study . For day 1, the mean maximum concentration of drug in serum (C(max)) and the area under the concentration-time curve from 0 to 24 h (AUC(0-24)) were 3 . 4 mg/liter and 30.2 mg . h/liter, respectively . Corresponding means on day 10 were 4.5 mg/liter and 48 mg . h/liter, respectively . On day 10, the mean elimination half-life was approximately 12 h . Plasma moxifloxacin concentrations exceeded the MIC for Streptococcus pneumoniae throughout the 24-h dosing period . The day 1 and day 10 mean AUC/MIC ratios were 121 and 192, respectively, and the mean C(max)/MIC ratios were 13 and 18, respectively . Moxifloxacin was well tolerated; no clinically relevant changes in the standard laboratory tests, vital signs, or ECG were observed . Pharmacokinetic parameters demonstrated linearity, and estimates of pharmacokinetic/pharmacodynamic ratios (AUC/MIC and C(max)/MIC) indicate that the regimen of 400-mg once daily should be effective for treating a variety of infections . Moxifloxacin was found to be safe and well tolerated in healthy volunteers when it was given as a single daily 400-mg dose for 10 days. Antimicrob Agents Chemother, 1999 Nov, 43(11), 2579 - 85 Activities of fluoroquinolones against Streptococcus pneumoniae type II topoisomerases purified as recombinant proteins; Morrissey I et al.; Streptococcus pneumoniae topoisomerase IV and DNA gyrase have been purified from a fluoroquinolone-susceptible Streptococcus pneumoniae strain, from first-step mutants showing low-level resistance to ciprofloxacin, sparfloxacin, levofloxacin, and ofloxacin, and from two clinical isolates showing intermediate- and high-level fluoroquinolone resistance by a gene cloning method that produces recombinant proteins from Escherichia coli . The concentrations of ciprofloxacin, sparfloxacin, levofloxacin, or ofloxacin required to inhibit wild-type topoisomerase IV were 8 to 16 times lower than those required to inhibit wild-type DNA gyrase . Furthermore, low-level resistance to these fluoroquinolones was entirely due to the reduced inhibitory activity of fluoroquinolones against topoisomerase IV . For all the laboratory strains, the 50% inhibitory concentration for topoisomerase IV directly correlated with the MIC . We therefore propose that with S . pneumoniae, ciprofloxacin, sparfloxacin, levofloxacin, and ofloxacin target topoisomerase IV in preference to DNA gyrase . Sitafloxacin, on the other hand, was found to be equipotent against either enzyme . This characteristic is unique for a fluoroquinolone . A reduction in the sensitivities of both topoisomerase IV and DNA gyrase are required, however, to achieve intermediate- or high-level fluoroquinolone resistance in S . pneumoniae. Microbiology, 1999 Oct, 145 ( Pt 10), 2647 - 53 Repeated extragenic sequences in prokaryotic genomes: a proposal for the origin and dynamics of the RUP element in Streptococcus pneumoniae; Oggioni MR et al.; A survey of all Streptococcus pneumoniae GenBank/EMBL DNA sequence entries and of the public domain sequence (representing more than 90% of the genome) of an S . pneumoniae type 4 strain allowed identification of 108 copies of a 107-bp-long highly repeated intergenic element called RUP (for repeat unit of pneumococcus) . Several features of the element, revealed in this study, led to the proposal that RUP is an insertion sequence (IS)-derivative that could still be mobile . Among these features are: (1) a highly significant homology between the terminal inverted repeats (IRs) of RUPs and of IS630-Spn1, a new putative IS of S . pneumoniae; and (2) insertion at a TA dinucleotide, a characteristic target of several members of the IS630 family . Trans-mobilization of RUP is therefore proposed to be mediated by the transposase of IS630-Spn1 . To account for the observation that RUPs are distributed among four subtypes which exhibit different degrees of sequence homogeneity, a scenario is invoked based on successive stages of RUP mobility and non-mobility, depending on whether an active transposase is present or absent . In the latter situation, an active transposase could be reintroduced into the species through natural transformation . Examination of sequences flanking RUP revealed a preferential association with ISs . It also provided evidence that RUPs promote sequence rearrangements, thereby contributing to genome flexibility . The possibility that RUP preferentially targets transforming DNA of foreign origin and subsequently favours disruption/rearrangement of exogenous sequences is discussed. Am Heart J, 1999 Nov, 138(5 Pt 2), S534 - 6 Multiple infections in carotid atherosclerotic plaques; Chiu B; BACKGROUND: Chlamydia pneumoniae, cytomegalovirus, herpes simplex virus, and recently, periodontal disease, have been associated with human atherosclerosis . Porphyromonas gingivalis and Streptococcus sanguis are major pathogens associated with periodontitis, a common chronic inflammatory condition in adults . Investigators have found that these infectious agents may influence vascular cell functions by inducing thrombus formation, vascular cell proliferation, apoptosis, and cell death . METHODS AND RESULTS: The main purpose of our study was to investigate the relation between the presence of multiple infectious agents in human carotid endarterectomy specimens and pathoanatomic features of the corresponding carotid plaques . Histologically, plaque rupture of the fibrous cap and communication of the luminal thrombus with the central necrotic lipid core was seen in or at proximity to the macrophage-rich shoulder (unstable plaque region) . Thrombus within the lipid core without plaque rupture was occasionally found near the internal elastic lamina, associated with increased vascularity and lymphocytic infiltrate . Apoptosis, as detected by both the immunohistochemical staining of apoptosis-related proteins and in situ labeling of internucleosomally degraded DNA, was common in atherosclerotic plaques . Immunostainings for C pneumoniae, cytomegalovirus, herpes simplex virus-1, P gingivalis, and S sanguis were positive in the carotid plaques . From 1 to 4 organisms were found in the same specimen . The micro-organisms were immunolocalized in plaque shoulders and lymphohistiocytic infiltrate, associated with ulcer and thrombus formation, and adjacent to areas of strong labeling for apoptotic bodies . CONCLUSIONS: Our data provide evidence that multiple infectious agents may be found in atherosclerotic plaques, and sometimes in the same specimen . The current study is the first to report the detection of 2 major odontopathogens, P gingivalis and S sanguis, in atherosclerotic plaques . The immunolocalization of these micro-organisms within unstable plaque regions and their association with plaque ulceration, thrombosis, and apoptosis in vascular cells are intriguing . Multiple infectious agents may alter vascular cell function and provide a "trigger" for acute ischemic stroke events . Further evidence from human studies and animal models will be needed. Kansenshogaku Zasshi, 1999 Sep, 73(9), 884 - 92 {Clinical analysis of pneumonia in the elderly in a community hospital--comparison of community-acquired pneumonia and nosocomial pneumonia}; Kobashi Y et al.; We experienced 530 elderly cases with pneumonia among 930 patients with pneumonia in Kawasaki Medical School Kawasaki Hospital between April 1986 and September 1998 . Clinical analysis of all these patients and a comparison of one group consisting of 418 patients with community-acquired pneumonia and another group composed of 112 patients with nosocomial pneumonia were performed . In all of the elderly patients with pneumonia, respiratory symptoms and inflammatory findings were less frequent, but were frequent for those in poor general and nutritional condition . The causative microorganism was isolated in 42% of these patients . Streptococcus pneumoniae, MSSA and Klebsiella pneumoniae were frequently isolated from the sputum of the patients with community-acquired pneumonia, while Methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, Methicillin-sensitive Staphylococcus aureus (MSSA) were frequently isolated from that of nosocomial pneumonia patients . Mycoplasma pneumoniae, Chlamydia pneumoniae and some viruses were less frequent for patients in both groups . Although many intravenous antibiotics, such as cephem or carbapenem were administered to patients in both groups, the prognosis was relatively good for those with community acquired pneumonia but was extremely poor for those with nosocomial pneumonia despite mechanical ventilation or steroid pulse therapy for many patients. Neurology, 1999 Oct 22, 53(7), 1584 - 7 Clinical outcome in pneumococcal meningitis correlates with CSF lipoteichoic acid concentrations; Schneider O et al.; Lipoteichoic and teichoic acids are components of the cell wall of Streptococcus pneumoniae . A recently developed enzyme immunoassay was used in patients with pneumococcal meningitis to investigate lipoteichoic and teichoic acid concentrations in CSF at the first lumbar puncture in relation to the clinical outcome determined by the Glasgow Outcome Scale . Lipoteichoic and teichoic acid concentrations in CSF were significantly associated with neurologic sequelae and mortality in S . pneumoniae meningitis. Can J Vet Res, 1999 Oct, 63(4), 269 - 75 Experimental exposure of young pigs using a pathogenic strain of Streptococcus suis serotype 2 and evaluation of this method for disease prevention; Torremorell M et al.; Control of Streptococcus suis infections and associated disease have proven to be a difficult challenge under most farm conditions . The objective of this study was to experimentally expose young pigs with a pathogenic strain of S . suis serotype 2 as a means of controlling the disease in a commercial swine farm . Prior to the start of the study, the pathogenic S . suis strain responsible for mortality in the farm was identified and used to experimentally inoculate baby piglets . Over a 3-week period, groups of pigs were selected (100 pigs/wk) and divided into 2 groups: control (50 pigs/week) and experimentally exposed (50 pigs/week) . Pigs in the experimentally exposed group were inoculated at 5 d old by tonsillar swabbing with the pathogenic S . suis farm isolate . The effect of exposure with this pathogenic strain was evaluated during the nursery and finishing stages and was based on: morbidity (pigs with central nervous signs (CNS) and/or lameness), mortality and number of treatments required by pigs that had either CNS or lameness . The relative risk (RR) of acquiring disease due to S . suis infection was also calculated . Results showed that morbidity in the experimentally exposed groups was lower than in the control group and these results were statistically different (P = 0.006) . Experimentally exposed pigs also showed a statistically significant reduction in lameness problems (P = 0.012), but not in CNS (P = 0.20) or mortality (P = 0.59) . Pigs in the control group had an increased RR of 4.76, 8.77 and 2.7 for morbidity, to have lameness or to have CNS signs, respectively . In conclusion, experimental exposure of young pigs with the farm's pathogenic S . suis strain at a young age, had a positive effect in reducing clinical signs characteristics of S . suis infection . This method constitutes a novel approach to the control of S . suis infections in swine farms. Orv Hetil, 1999 Sep 19, 140(38), 2111 - 5 {Non-invasive management of multiple brain abscesses . Case report and review of the literature}; Hoffmann I et al.; The authors report a case and treatment of multiple brain abscesses located in the cerebrum and cerebellum combined with subdural empyema . In conjunction with the case report, the authors review the literature on the pathogenesis of brain abscesses and discuss therapeutic strategies concerning the topic . In the case presented, the primary infection persisted in the lung causing subclinical bronchitis . The hemoculture showed evidence of Streptococcus mitis infection . Although the etiological role of this bacterium in meningitis is known, it rarely causes bacterial meningitis without underlying predisposing factors . In their case, the patient was free of the most common predisposing factors such as congenital heart disease or immunodeficiency . Following the 2 month period of latency, a rapid onset of the symptoms of intracranial inflammation could be observed: fever, headache, meningeal symptoms, focal neurological symptoms and coma . They were not able to identify any bacteria in the cerebrospinal fluid; the Streptocossus mitis could be cultivated only from the haemoculture . The cytological analysis of the cerebrospinal fluid showed typical signs of bacterial infection and the cranial Computed Tomography revealed multiple cerebral abscesses . Neurosurgical intervention was not recommended because of the number, localization and size of the focal lesions . The therapy consisted of intravenous administration of 24 x 10(6) IU/die Penicillin and 4 g/die ceftriaxon . For supportive therapy, Mannitol B, 3 mg/die clonazepam and 300 mg/die phenytoin were administered . Corticosteroids were not used during the course of therapy . Two years later the 55 year old female is symptom free and doing well. Infect Immun, 1999 Nov, 67(11), 6130 - 8 Bacterial species- and strain-dependent induction of tissue factor in human vascular endothelial cells; Veltrop MH et al.; A cardinal process in bacterial endocarditis (BE) is the activation of the clotting system and the formation of a fibrin clot on the inner surface of the heart, the so-called endocardial vegetation . The processes that lead to the activation of the clotting system on endothelial surfaces upon exposure to bacteria are largely unknown . In the present study, we investigated in an in vitro model whether infection of human endothelial cells (EC) with bacteria that are relevant to BE, such as Staphylococcus aureus, Streptococcus sanguis, and Staphylococcus epidermidis, leads to induction of tissue factor (TF)-dependent procoagulant activity (TFA) and whether this process is influenced by host factors, such as interleukin-1 (IL-1), that are produced in response to the bacteremia in vivo . The results show that S . aureus binds to and is internalized by EC, resulting in expression of TF mRNA and TF surface protein as well as generation of TFA within 4 to 8 h after infection . No TFA was found when EC were exposed to UV-irradiated S . aureus or bacterial cell wall fragments . S . sanguis and S . epidermidis, although also binding to EC, did not induce endothelial TFA . This indicates a species and strain dependency . EC also expressed TFA after exposure to IL-1 . The enhanced TFA of EC after exposure to S . aureus was not prevented by IL-1 receptor antagonist, arguing against an auto- or paracrine contribution of endogenous IL-1 . When IL-1 was applied together with bacteria, this had a synergistic effect on the induction of EC TFA . This was found in particular with S . aureus but also, although to a lesser degree, with S . sanguis and S . epidermidis . This influence of IL-1 on the species- and strain-dependent induction of EC TFA suggests that bacterial factors as well as host factors orchestrate the induction of coagulation in an early stage in the pathogenesis of endovascular disease, such as BE. Infect Immun, 1999 Nov, 67(11), 6098 - 103 A new rat model of otitis media caused by Streptococcus pneumoniae: conditions and application in immunization protocols; van der Ven LT et al.; Streptococcus pneumoniae (pneumococcus {Pn}) can be cultured from up to 50% of acute otitis media (AOM) effusions, and these bacteria are the most common cause of AOM-related complications . With the recent advent of antibiotic-resistant Pn strains, treatment of Pn infections may meet with serious difficulties . Prevention through vaccination, notably for the four most common occurring Pn serotypes in humans (i.e., Pn 6B, Pn 14, Pn 19F, and Pn 23F), is a helpful alternative . Testing of vaccine efficacy should occur in an appropriate animal AOM model, which is presented here . The four involved Pn serotypes are not pathogenic to the rat, which was chosen as the experimental animal for practical reasons . To induce a natural infection (i.e., ascending through the eustachian tube), the mucociliary clearance of the eustachian tube was impaired by infusing histamine into the tympanic cavity on 2 consecutive days before intranasal inoculation of the bacteria . With this simple protocol, high and reproducible infection rates, as determined with bacterial cultures, of Pn-induced AOM (approximately 70%) with the two major Pn serotypes 14 and 19F (Pn 14 and Pn 19F) were obtained, whereas lower infection rates (25 to 50%) with Pn 6B and Pn 23F were obtained . In this model, intranasal priming with pneumococci, as well as subcutaneous vaccination with Pn 14 tetanus toxoid-conjugated polysaccharide, induced a protective effect against the induction of otitis media with these bacteria . This shows that immunity to Pn 14 AOM can be induced by both mucosal and systemic presentations of antigen . In conclusion, we have developed an animal model for Pn-induced AOM, which is suitable for the evaluation of the protecting effect of immunization. Infect Immun, 1999 Nov, 67(11), 5979 - 84 Determination of antibody responses of elderly adults to all 23 capsular polysaccharides after pneumococcal vaccination; Rubins JB et al.; The 23-valent pneumococcal polysaccharide vaccine was formulated to prevent invasive infection in the elderly and other high-risk populations from the most prevalent Streptococcus pneumoniae serotypes . However, the immunogenicity of all 23 vaccine polysaccharides has not been fully characterized in elderly adults . We previously reported that whereas the majority of elderly subjects had vigorous immune responses to selected pneumococcal vaccine polysaccharides, a subset of elderly individuals responded to fewer than two of seven vaccine serotypes after immunization . To determine whether these elderly low responders have a general inability to respond to pneumococcal vaccine and to determine whether elderly low responders might be identified by their responses to a few polysaccharides, we measured antibody responses of elderly adults to all 23 vaccine polysaccharides after pneumococcal immunization . As a group, elderly subjects showed a significant rise after immunization in geometric mean antibody levels to all 23 vaccine serotypes . However, when individual rather than group immune responses were assessed, the 23-valent vaccine did not appear to be uniformly immunogenic in these elderly subjects . Eleven elderly subjects (20%) had twofold increases in specific antibody after vaccination to only 5 or fewer of the 23 vaccine polysaccharides, and they did not respond to the most prevalent serotypes causing invasive disease . Antibody responses to serotype 9N were found to reliably distinguish low vaccine responders from other elderly subjects . However, no particular group of vaccine polysaccharides could be used as a marker for adequate immune responses if only postvaccination sera were analyzed. Infect Immun, 1999 Nov, 67(11), 5892 - 7 Intranasal immunization with pneumococcal polysaccharide conjugate vaccines with nontoxic mutants of Escherichia coli heat-labile enterotoxins as adjuvants protects mice against invasive pneumococcal infections; Jakobsen H et al.; Host defenses against Streptococcus pneumoniae depend largely on phagocytosis following opsonization by polysaccharide-specific immunoglobulin G (IgG) antibodies and complement . Since colonization of the respiratory mucosa is the first step in pneumococcal pathogenesis, mucosal immune responses may play a significant role . In addition to inducing systemic immune responses, mucosal vaccination with an effective adjuvant has the advantage of inducing mucosal IgA antibodies . The heat-labile enterotoxin (LT) of Escherichia coli is a well-studied mucosal adjuvant, and adjuvant activity of nontoxic LT mutants has been demonstrated for several protein antigens . We investigated the immunogenicity of pneumococcal polysaccharide conjugate vaccines (PNC) of serotypes 1 and 3 in mice after intranasal (i.n.) immunization by using as an adjuvant the nontoxic LT mutant LT-K63 or LT-R72, which has minimal residual toxicity . Pneumococcal serotype-specific antibodies were measured in serum (IgM, IgG, and IgA) and saliva (IgA), and vaccine-induced protection was evaluated by i.n . challenge with virulent pneumococci of the homologous serotype . When administered with LT mutants, i.n . immunization with both conjugates induced systemic and mucosal immune responses, and serum IgG antibody levels were significantly higher than after subcutaneous immunization . All mice immunized i.n . with PNC-1 and LT mutants were protected against bacteremia and cleared the pneumococci from the lung 24 h after i.n . challenge; pneumococcal density correlated significantly with serum IgG antibody levels . Similarly, the survival of mice immunized i.n . with PNC-3 and LT mutants was significantly prolonged . These results demonstrate that i.n . vaccination with PNC and potent adjuvants can protect mice against invasive and lethal pneumococcal infections, indicating that mucosal vaccination with PNC may be an alternative vaccination strategy for humans. Arch Oral Biol, 1999 Oct, 44(10), 871 - 83 Characterization of the mucosal immune response in breast milk after peroral immunization of chimpanzees (Pan troglodytes) with Streptococcus mutans; Tyler BM et al.; The characteristics of the mucosal immune response to Streptococcus mutans cells, antigen A, antigen B, glucosyltransferases and glucan-binding proteins were examined in four pregnant chimpanzees that had been immunized perorally with Strep . mutans . Six pregnant chimpanzees served as non-immunized controls . None of the chimpanzees harbored S . mutans . Samples of milk were collected from all animals throughout the experiment . Peroral immunization resulted in an overall 17-fold median increase in SIgA in milk . Although SIgA1 comprised almost two-thirds of milk SIgA, Strep . mutans whole-cell antibody activity was contained predominantly in the SIgA2 subclass . The difference between the specific activities of anti-Strep . mutans SIgA1 and SIgA2 antibodies compared over time reached the borderline of statistical significance (p = 0.08) . The avidity of anti-Strep . mutans antibodies was low in three of four chimpanzees and there was no evidence of affinity maturation . SIgA antibodies from the milk of all four immunized chimpanzees recognized antigen A . In three animals these antibodies were restricted to the SIgA1 subclass and, in one animal, anti-A antibodies were confined to SIgA2 . Antibodies from all of the immunized chimpanzees recognized degradation products of antigen B in both the SIgA1 and the SIgA2 subclasses . Only two of four immunized chimpanzees responded to glucosyltransferases and these antibodies were restricted to the SIgA1 subclass . None of the chimpanzees responded to the 74-kDa glucan-binding protein . However, three animals produced SIgA1 antibodies against the 59-kDa glucan-binding protein and two of these also produced SIgA2 antibodies against this protein. Pediatr Infect Dis J, 1999 Oct, 18(10), 902 - 7 Meningitis in pediatric cancer patients: a review of forty cases from a single institution; Sommers LM et al.; BACKGROUND: Although the clinical features of bacterial meningitis in adult cancer patients and in healthy children have been described, no previous large series has described the clinical features of meningitis in pediatric cancer patients . We performed a retrospective review of bacterial or fungal meningitis in pediatric cancer patients to determine its clinical presentation, microbiology and outcome . METHOD: We reviewed the medical records of all patients younger than 18 years old with a diagnoses of any malignancy and bacterial or fungal meningitis at Children's Hospital and Regional Medical Center in Seattle, WA, from January, 1981, to June, 1998 . RESULTS: During the study period there were 40 cases of bacterial or fungal meningitis in 36 pediatric cancer patients . Most patients (65%) had recent neurosurgery, a central nervous system device or cerebrospinal fluid leak . Neutropenia was present in 30% of patients . Fever and altered mental status were the most consistent signs at presentation . In addition at least one additional symptom or sign of meningitis (headache, neck pain or rigidity, seizures or photophobia) was present in 77% of cases . Staphylococcus aureus and Streptococcus pneumoniae were the most common microbiologic isolates . The five patients with fatal outcome were neutropenic . Neutropenia and seizures within 2 days of presentation were associated with long neurologic sequelae . CONCLUSIONS: Meningitis in pediatric cancer patients was associated with significant morbidity and mortality . Pediatric cancer patients with meningitis had clinical features and microbiology distinctly different from those of adult cancer patients and normal children with meningitis. Clin Infect Dis, 1999 Sep, 29(3), 580 - 5 Penicillin-nonsusceptible Streptococcus pneumoniae at San Francisco General Hospital; Winston LG et al.; Positive pneumococcal cultures of specimens from adult inpatients at San Francisco General Hospital (SFGH) during the period of 11 August 1994 through 31 December 1996 were identified retrospectively . Of the isolates recovered, 15.5% were not penicillin-susceptible (MIC, > or =.1 microg/mL) . A case-control study was performed to evaluate risk factors for colonization or infection with penicillin-nonsusceptible Streptococcus pneumoniae (PNSP) and outcomes . Cases (n = 65) were adult inpatients with a positive culture for PNSP, and controls (n = 411) were adult inpatients with a positive culture for penicillin-susceptible pneumococci (PSSP) and no evidence of PNSP . Cases were less likely to have pneumococcal bacteremia (15.4% versus 39.4%; P<.001) and less likely to have pneumonia (50.8% versus 68.9%; P = .006) . In a multiple logistic regression model, recent hospital admission and absence of bacteremia were independent predictors of penicillin-nonsusceptibility . Human immunodeficiency virus infection, mortality, and length of hospitalization were not significantly different among cases and controls . These data suggest that PNSP may be less virulent (cause less pulmonary infection) and/or less invasive (cause fewer bloodstream infections) than PSSP at SFGH. Int Endod J, 1999 May, 32(3), 197 - 203 A comparison of MTA, Super-EBA, composite and amalgam as root-end filling materials using a bacterial microleakage model; Adamo HL et al.; AIM: The aim of this study was to compare traditional and newly developed root-end filling materials for resistance to bacterial microleakage . METHODOLOGY: Sixty extracted single-rooted teeth were randomly divided into five groups for root-end filling with mineral trioxide aggregate, Super-EBA, TPH composite resin with ProBond dentine bonding agent, Dispersalloy amalgam with and without ProBond, and positive and negative control groups . Root canals were instrumented using the step-back technique and simulated root-end resections performed . Root-end filling materials were placed in 3 mm ultrasonic retropreparations . Nail varnish was applied to all external root surfaces to the level of the resected root ends to prevent lateral microleakage . Samples were sterilized in an ethylene oxide sterilizer for 12 h . Using a newly designed model system, the apical 3-4 mm of the roots were immersed in BHI culture medium with phenol red indicator within culture chambers . The coronal access of each specimen was inoculated every 48 h with a suspension of Streptococcus salivarius . Culture media were observed every 24 h for colour change indicating bacterial contamination . Media demonstrating colour change were plated for S . salivarius . Samples were observed for 12 weeks . RESULTS: At 4 weeks 10% of specimens from each experimental group had evidence of leakage . At 8 weeks 20% of specimens filled with amalgam without dentine bonding agent, Super-EBA and MTA had evidence of leakage . At 12 weeks minor differences between materials were noted . CONCLUSIONS: Under the conditions of the study, despite some variations, there were no statistically significant differences in rate of microleakage among the five groups tested at either 4, 8 or 12 weeks. Caries Res, 1999 Nov-Dec, 33(6), 446 - 54 Powdered milk micellar casein prevents oral colonization by Streptococcus sobrinus and dental caries in rats: a basis for the caries-protective effect of dairy products; Guggenheim B et al.; Three animal studies were performed to investigate the influence of the macromolecular structure of milk casein on caries incidence and the possible ecological changes of the oral microbiota by such casein fractions . Towards this end, rats were infected with mixed bacterial suspensions of Streptococcus sobrinus OMZ 176 and Actinomyces viscosus Ny1 . Various milk protein fractions were incorporated into carefully balanced powdered cariogenic diets to constitute the sole major protein component . Diets containing micellar casein had a pronounced and highly significant effect on almost all clinical and microbiological parameters examined . Both the formation of advanced dentinal fissure (B) and smooth surface (E) caries lesions was inhibited by diets containing micellar casein; this caries-inhibiting effect appeared to be due mainly to modifications within the plaque microbiota . The proportion of S . sobrinus in the oral cavity of rats was reduced (73-80%) by micellar casein-containing preparations, whereas the A . viscosus population was increased . Both these microbiological parameters were always negatively correlated . This appears to be the first example of a food component other than dietary sugars, selectively modifying the composition of the dental plaque microbiota of rats in such a way as to reduce its pathogenic potential . It also demonstrates the importance of establishing a molecular basis for the role of food components, which prove to be beneficial to oral