Staphylococcus aureus

Farmaco, 2000 Sep-Oct, 55(9-10), 619 - 23
Synthesis and antimicrobial activity of new adamantane derivatives II; Orzeszko A et al.; A series of new derivatives of adamantane was synthesised . The new compound 4-(adamant-1-ylethylenoxycarbonyl)phthalanhydride obtained from 1-adamantaneethanol and trimellitic anhydride chloride, as well as 4-(adamant-1-ylmethylenoxycarbonyl)phthalanhydride, appeared very useful for preparation of a number of N-substituted phthalimides . Antimicrobial activity of newly obtained derivatives such as, for example, 4-(adamant-1-ylethylenoxycarbonyl)-N-(L-phenylalanyl)phthalimide or 4-(adamant-1-ylmethylenoxycarbonyl)-N-(L-leucyl)-phthalimide was tested against Staphylococcus aureus, Bacillus sp., Micrococcus flavus and Enterococcus faecium . The minimal inhibitory concentrations for these compounds against Bacillus cereus were 15 and 8 microg/ml, respectively.

FEMS Microbiol Lett, 2001 Jan 1, 194(1), 77 - 82
Involvement of multiple genetic loci in Staphylococcus aureus teicoplanin resistance; Bischoff M et al.; Teicoplanin resistance was transformed from a teicoplanin-resistant Staphylococcus aureus into the susceptible strain BB255 to give strain BB938 . The cell wall composition, amidation of the iD-glutamate, and peptide crosslinking were identical in BB938 as in BB255 except for a 60% increased length of the glycan chain . Transductional crosses revealed that at least two distinct loci contributed in a cumulative fashion to teicoplanin resistance . One of these loci correlated with a mutation inactivating the anti-sigma factor RsbW . This mutation must have occurred during transformation and selection for teicoplanin resistance in BB938 . Genetic manipulations involving the sigB operon showed that transcription factor SigB contributed to decreased teicoplanin susceptibility.

J Cardiovasc Surg (Torino), 2000 Oct, 41(5), 715 - 9
Treatment of recurrent postoperative mediastinitis with granulated sugar; De Feo M et al.; BACKGROUND: The authors report their experience with granulated sugar as dressing technique in the treatment of postoperative mediastinitis refractory to a closed irrigation system . METHODS: Between January 1990 and January 1998, mediastinitis developed in 61 (0,93%) of 6521 patients who had undergone open heart surgery . Diagnosis of sternal infections was based on wound tenderness, drainage, cellulitis, fever associated with sternal instability . All of them were initially treated with surgical debridement and closed chest irrigation . Nine patients with postcardiotomy mediastinitis refractory to closed chest irrigation underwent open dressing with granulated sugar . All of them were febrile with leukocytosis and positive wound cultures . RESULTS: Bacteria isolated were staphylococcus aureus in 6 cases, staphylococcus epidermidis in 2 and pseudomonas in 1 . Redebridement was performed in all cases and the wound was filled with granulated sugar four times a day . Fever ceased within 4.3+/-1.3 days from the beginning of treatment and WBC became normal after 6.6+/-1.6 days . Three patients had hyperbaric therapy as associated treatment . Complete wound healing was achieved in 58.8+/-32.9 days (three patients underwent successful pectoralis muscle flaps) . CONCLUSIONS: Sugar treatment is a reasonable and effective option in patients with mediastinitis refractory to closed irrigation treatment . It may be used either as primary treatment or as a bridge to pectoralis muscle flaps.

Radiol Med (Torino), 2000 Sep, 100(3), 112 - 9
{Radiologic diagnosis of spondylodiscitis: role of magnetic resonance}; Cusmano F et al.; PURPOSE: To report the Magnetic Resonance Imaging (MRI) features of acute and chronic spontaneous spondylodiscitis as well as any typical patterns which can be useful for the differential diagnosis between pyogenic and tuberculous forms . MATERIAL AND METHODS: Eleven patients affected with spontaneous spondylodiscitis were selected for the study; they were 7 men and 4 women ranging in age 33-87 years (mean: 64) . We excluded the patients with iatrogenic spondylodiscitis . MR images were acquired with a superconductive magnet at 1.5, with the following sequences: sagittal PD and T2-weighted TSE, sagittal T1-weighted SE, axial PD and T2-weighted TSE for the lumbar spine, axial T2-weighted GRE for the cervical and dorsal spine and axial and sagittal T1-weighted SE after contrast agent (gadolinium DTPA) injection . MR images were reviewed by three experienced radiologists and morphological and signal intensity changes of vertebral body and disk were recorded on a standard form . In 9 patients it was possible to compare MR to CT findings . RESULTS: At the time of our observation all patients reported pain at the spine level, associated with fever and weight loss in 50% of cases and with increased values of the inflammatory markers . Three patients had infectious diseases in other organs and 2 were diabetics . Biopsy was performed in two cases only and demonstrated Staphylococcus aureus in one and Mycobacterium tuberculosis in the other patient . MRI allowed the correct diagnosis to be made in all cases, demonstrating the pathological involvement of the paravertebral structures and into the spinal canal earlier and more accurately than CT . A common finding in pyogenic and tuberculous spondylodiscitis was the low signal of the subcortical bone marrow on T1-weighted sagittal images, which enhanced after Gd-DTPA administration and became intermediate or high on T2-weighted images . Moreover, the steady high signal intensity of the disk on T2-weighted images and its contrast enhancement on T1-weighted images is typical for an acute inflammatory process . CONCLUSIONS: Based on our personal experience and literature data, we believe MRI to be the most sensitive technique for the diagnosis of spondylodiscitis in the acute phase, whereas it is comparable to CT in the chronic stage of the disease . At present MRI does not allow to differentiate pyogenic from tuberculous forms.

Curr Opin Rheumatol, 2001 Jan, 13(1), 3 - 11
Management of the ear, nose, and throat manifestations of Wegener granulomatosis: an otorhinolaryngologist's perspective; Rasmussen N; A diagnosis of Wegener granulomatosis requires granulomatous manifestations in the respiratory tract . With the increasing use of antineutrophil cytoplasmic autoantibodies as a diagnostic tool, Wegener granulomatosis is diagnosed earlier than in the past, and not infrequently when only ear, nose and throat manifestations are present, placing the otorhinolaryngologist in a central role in diagnosis and management . Diagnostic biopsies should be obtained from active lesions in the nose and paranasal sinuses and concomitant infection should be identified . Because of the apparent relation between infection and activation of disease, the management of infections-especially those due to Staphylococcus aureus-requires special attention . The increasing numbers of early cases identified warrants further investigations of whether less toxic treatment regimens will be of advantage in such cases . Medical and surgical treatment of the acute and chronic manifestations presents specific problems because of altered immune competence, prevalent superinfection, and tissue destruction, and is therefore best taken care of by specially dedicated otorhinolaryngologists.

Med Dosw Mikrobiol, 2000, 52(3), 229 - 36
{Methicillin resistant clinical strains of Staphylococcus aureus isolated from patients in the State Clinical Hospital Nr 2 in Szczecin}; Bilska I et al.; Over a fivefold increase, from 11% to 58%, in the prevalence of methicillin-resistance was observed in 1994-95 amongst clinical isolates of Staphylococcus aureus in the State Clinical Hospital No 2 in Szczecin, one of the largest hospitals in the West Pomeranian region of Poland . The aim of this study was to see if any one particular strain was responsible for this apparent outbreak . Fifty-six randomly selected isolates were typed by SmaI macrorestriction analysis using PFGE and by analysis of antimicrobial susceptibility patterns . Results indicate the presence of two epidemic multi-drug resistant MRSA strains . Over 85% of typed MRSA belonged to the first strain, which was probably present in the hospital long before 1994 . MRSA of this strain were isolated from patients in 8 hospital wards . The second strain was introduced into two wards of the hospital in the last year of the study.

Med Dosw Mikrobiol, 2000, 52(3), 217 - 22
{Use of PCR for evaluating detection of coa and nuc genes in methicillin-resistant, coagulase-negative strains of Staphylococcus aureus (MRSA-CN)}; Mlynarczyk A et al.; Strains showing a negative reaction in tube test for coagulase constitute 10 to 20% of all Staphylococcus aureus isolated from patients of Hospital of Infant Jesus in Warsaw . Most of them are MRSA . In 42 MRSA strains showing negative reaction for coagulase, the presence of coagulase (coa) and nuclease (nucA) genes was checked . Determination of whole cell DNA with PCR reaction was performed . The obtained results revealed that all 42 strains possessed gene nucA, but only 39 strains possessed the coa gene.

Ann Transplant, 2000, 5(3), 13 - 9
Anastomotic infections in lung transplant recipients; Hadjiliadis D et al.; OBJECTIVES: Anastomotic infections are an uncommon but potentially devastating complication after lung transplantation . The incidence, microbiology, predisposing factors, and clinical outcomes of anastomotic infections have not been well described . METHODS: We performed a retrospective chart review of the first 283 lung or heart-lung transplant recipients performed at Duke University Medical Center and identified all cases of anastomotic infection . RESULTS: Fifteen patients (5.3%) developed anastomotic infections . Aspergillus caused infection in six patients, Candida in eight patients and Staphylococcus aureus in one patient . Bilateral or right lung transplantation and the use of induction immunosuppression with monoclonoal or polyclonal antibodies are associated with a higher incidence of anastomotic infections . All patients with fungal anastomotic infections were treated with a combination of systemic and inhaled antifungal agents . All patients had improvement of their anastomotic sites after treatment and no patients developed anastomotic dehiscence . CONCLUSIONS: Anastomotic infection is an infrequent complication after lung transplantation, and is caused predominately by fungal pathogens . In contrast to previous reports, anastomotic dehiscence did not occur in any patient in our series . Treatment with the combination of inhaled and systemic antimicrobial agents may have favorably affected clinical outcomes.

Am J Nephrol, 2000 Nov-Dec, 20(6), 463 - 7
Use of pulsed-field gel electrophoresis in the analysis of recurrent Staphylococcus aureus infections in patients on continuous ambulatory peritoneal dialysis; Chang HR et al.; BACKGROUND/AIM: The purpose of this study was to evaluate pulsed-field gel electrophoresis (PFGE) for distinguishing between relapse and reinfection of Staphylococcus aureus infections in patients on continuous ambulatory peritoneal dialysis (CAPD) . METHODS: Between July 1993 and May 1997, 4 patients with recurrent CAPD-associated infections caused by S . aureus we enrolled in this study . There were nine episodes of peritonitis, one episode of temporary double lumen catheter infection, and one episode of Hickman catheter infection . A total of eleven S . aureus isolates were collected from peritoneal fluid (n = 9) and blood (n = 2) . PFGE typing was applied . RESULTS: In our study, from PFGE typing, the 11 S . aureus isolates were classified into seven patterns . Antibiogram profiling classified only four patterns . Patient A had a reinfection by another strain of S . aureus, and patient B had three episodes of peritonitis caused by the same strain of S . aureus due to exit site infections . Patient C had two episodes of CAPD peritonitis caused by two different strains, respectively . Patient D had four episodes of S . aureus infection (three CAPD peritonitis and one bacteremia); the first two episodes of peritonitis were caused by an identical strain of S . aureus, whereas the subsequent two infections were caused by other organisms . CONCLUSION: PFGE has a high discriminatory power and can be an assistant method to antibiogram profiling for distinguishing relapse from reinfection in CAPD-associated peritonitis .

Am J Emerg Med, 2001 Jan, 19(1), 1 - 5
Bacterial counts in experimental, contaminated crush wounds irrigated with various concentrations of cefazolin and penicillin; Lammers R et al.; The objective of this study was to determine if three different concentrations of cefazolin and penicillin irrigation solutions reduce quantitative bacterial counts in experimental crush wounds contaminated with multiple species of bacteria . The design used was a randomized, blinded, experimental animal study . An animal bite wound model was created by innoculating crushed incisions with three species of bacteria . Four paravertebral incisions extending to deep fascia were created in each of twelve anesthetized albino guinea pigs . Wound edges were clamped with a hemostat for five seconds to create crushed, devitalized tissue within each wound . Wounds were inoculated with 0.4 mL of a standard solution of Staphylococcus aureus, Bacterioides fragilis, and Pasturella multocida and covered . Four hours after inoculation, each wound was scrubbed for 30 seconds with 20% poloxamer 188 and then irrigated with 100 mL of one of four solutions: normal saline solution (control); cefazolin (CZ) 2 mg/mL, plus penicillin G (PCN) 200 units/mL (low dose); CZ 10 mg/mL, plus PCN 2,000 units/mL (intermediate dose); and CZ 50 mg/mL, plus PCN 20, 000 units/mL (high dose) . Investigators were blinded to the solutions used . Wounds were covered with a vapor-permeable dressing . Six days after treatment, each wound was examined for signs of infection and then excised for quantitative bacteriologic analysis . Colony counts were reported as counts per gram of tissue . Wounds in the four irrigation solution groups were compared using ANOVA . A log difference of 3 was considered significant . The average log total bacteria/gram tissue for the four groups were: control, 4.35 (95% CI; 1.01); low dose, 4.09 (95% CI; 1.42); intermediate dose, 4.47 (95% CI; 1.27); and high dose, 3.45 (95% CI; 1.33) . No wounds in the high-dose group had any clinical signs of infection, whereas 50% of wounds in the intermediate dose group, 42% in the low dose group, and 33% in the control group had either erythema, induration, or purulence . There were no statistically significant differences in the bacterial counts/gram tissue or clinical infection rates in any of the groups . A formal trend analysis failed to find a significant linear trend for decreasing bacterial counts for either antibiotic . In this experimental bite wound model containing contaminated, crushed tissue, irrigation with various solutions of cefazolin plus penicillin G did not reduce quantitative bacterial counts more than 3.1 log total bacteria/gram tissue.

Microbiol Immunol, 2000, 44(11), 945 - 7
Comparative study of Staphylococcus aureus isolated from lesional and non-lesional skin of atopic dermatitis patients; Matsui K et al.; The skin of patients with atopic dermatitis (AD) is often colonized by Staphylococcus aureus, and superantigenic exotoxins produced by the organism are thought to be an important precipitating factor of AD . However, there are few reports comparing the characteristics of S . aureus isolated from the lesional and non-lesional skin of identical AD patients . In this study, therefore, we examined whether the presence of superantigen-producing S . aureus correlates with the formation of eczematous lesion of AD patients . The detection rate of S . aureus on the lesional skin of AD patients was higher than on the non-lesional skin of AD patients . Furthermore, the bacterial cell count of S . aureus on the lesional skin of AD patients was also significantly higher than that of the non-lesional skin of AD patients . However, there was no significant difference between the detection rate of superantigenic exotoxin-producing S . aureus on the lesional and nonlesional skin of AD patients . These results suggest that the number of S . aureus present is more important in the formation of eczematous lesion of AD patients than the presence of superantigenic exotoxin-producing S . aureus strains per se.

Microb Drug Resist, 2000 Fall, 6(3), 253 - 8
Similarity of antibiotic resistance patterns and molecular typing properties of methicillin-resistant Staphylococcus aureus isolates widely spread in hospitals in New York City and in a hospital in Tokyo, Japan; Aires de Sousa M et al.; One hundred and forty-three single-patient methicillin-resistant Staphylococcus aureus (MRSA) isolates collected during April-June, 1997, and February, 1998, in a hospital in Tokyo, Japan, were characterized by molecular typing techniques that involved hybridization of ClaI restriction digests with the mecA- and Tn554-specific DNA probes and determination of macrorestriction patterns of SmaI-digested chromosomal DNA by pulsed-field gel electrophoresis (PFGE) . A large proportion (76%) of the isolates carried the mecA polymorph I, Tn554 pattern A, and PFGE pattern A (clonal type I:A:A), which was the same as the clonal type of an MRSA widely spread in hospitals in New York City and hospitals in neighboring New Jersey, Connecticut, and Pennsylvania . Also similarly to the New York clone, most of the MRSA isolates from the Japanese hospital were resistant to penicillin, ciprofloxacin, erythromycin, tetracycline, and high concentrations (500 microg/ml) of spectinomycin, but were susceptible to chloramphenicol, sulfamethoxazole-trimethoprim, and rifampin . All of the 143 MRSA isolates had vancomycin MICs < or = 2 mg/L.

Microb Drug Resist, 2000 Fall, 6(3), 245 - 51
Distribution of methicillin-resistant Staphylococcus aureus clones among health care facilities in Connecticut, New Jersey, and Pennsylvania . ; Roberts RB et al.; A previous surveillance study conducted in 12 hospitals in New York City in 1996 identified a unique multidrug-resistant genetic lineage of methicillin-resistant Staphylococcus aureus (MRSA) that was widespread and accounted for as much as 42% of all the MRSA isolates . The purpose of the study described here was to determine possible geographic spread of this New York clone of MRSA to neighboring states . Single-patient MRSA isolates (258) from 29 health care facilities in Connecticut (CT), New Jersey (NJ), and Pennsylvania (PA) were collected during the calendar year 1998 . DNA typing, consisting of fingerprinting of chromosomal macrorestriction patterns generated by SmaI digestion followed by pulsed-field gel electrophoresis (PFGE), identified 22 patterns . PFGE type A, closely related to the PFGE type of the previously identified New York clone, accounted for 154 (60%) of 258 isolates . The clone was detected in all facilities, was predominant in 19 of the 29 health care centers, and accounted for 92% of the MRSA isolates collected in PA . The overwhelming majority of MRSA with PFGE type A was also resistant to erythromycin, ciprofloxacin, and clindamycin . One of the two most common PFGE subtypes detected in the three states sampled (PFGE subtype A1) had an identical PFGE pattern to that of the previously described vancomycin-resistant strain of S . aureus (VISA) recently detected in a hospital in Westchester, NY . The second most frequent MRSA clone with PFGE type E and accounting for 26% (68/258 isolates), also described earlier in the 12 New York City hospitals, was resistant not only to erythromycin, ciprofloxacin, and clindamycin, but also to gentamicin and sulfamethoxazole-trimethoprim as well . The unique multidrug resistance pattern of this second clone and its geographic distribution accounted for the differences observed in the frequency of multidrug resistance among MRSA isolates recovered in the three states . The pandemic Iberian clone recently detected in New York City was not detected among the 258 MRSA isolates recovered in CT, NJ, and PA.

Microb Drug Resist, 2000 Fall, 6(3), 239 - 44
Resistance rather than virulence selects for the clonal spread of methicillin-resistant Staphylococcus aureus: implications for MRSA transmission; Shopsin B et al.; The population structure of methicillin-resistant Staphylococcus aureus (MRSA) is predominantly clonal, which may be related to the fitness of the genetic background of the methicillin-susceptible S . aureus (MSSA) into which the mecA chromosomal resistant determinant has inserted . To test this idea, we assessed whether the genotypes of New York MRSA are present in MSSA populations by using a combination of protein A gene sequence typing (spa typing) and pulsed-field gel electrophoresis (PFGE) . Although about 16% of colonizing MSSA isolated from community subjects were related to MRSA, only one of the five predominant New York MRSA clonal types was found among the MSSA isolates . Similarly, among nosocomial MSSA, only four MRSA homologues were observed, two of which may have arisen through deletion of the mec element . Thus, MRSA clonal types represent a limited spectrum of the diversity seen in community and hospital S . aureus populations . The data are best explained by antibiotic selection pressure, as opposed to increased transmissibility or virulence, being responsible for the clonal dissemination of the resistance phenotype in MRSA genetic backgrounds, an in turn, the limited spread of these strains outside of the hospital environment.

Microb Drug Resist, 2000 Fall, 6(3), 231 - 8
Methicillin-resistant Staphylococcus aureus: phylogenetic relatedness between European epidemic clones and Swiss sporadic strains; Blanc DS et al.; We have compared the phylogenetic diversity of methicillin-resistant Staphylococcus aureus (MRSA) strains from Switzerland and their phylogenetic relationships with European epidemic clones, using multiprimer random amplification polymorphic DNA (RAPD) . Strains included 24 European epidemic clones (59 strains), 66 sporadic strains isolated in Switzerland in 1996-1997, and 15 reference strains of five other Staphylococcus species . Similarity and clustering analysis with the Jaccard's coefficient showed that the maximum genetic distance between MRSA strains was 0.43, whereas the minimum genetic distance between the six Staphylococcus species was 0.97, indicating that the method permits phylogenetic hierarchization . The 24 MRSA clones reported to be epidemic in European countries during the 1990s were distributed into seven different genetic clusters with a maximum distance of 0.29 among them . This clustering pattern was confirmed by the analysis of a subset of MRSA strains by multilocus enzyme electrophoresis at 12 loci . Most of the sporadic Swiss strains were distributed into these seven different genetic clusters, together with the epidemic MRSA clones . This suggests that there is no phylogenetic cluster specific to epidemic clones of MRSA.

Microb Drug Resist, 2000 Fall, 6(3), 223 - 9
Methicillin-resistant Staphylococcal aureus evolution in Australia over 35 years; Turnidge JD et al.; Australia has a long association methicillin-resistant Staphylococcus aureus (MRSA) . Its unique geographic and demographic features have led to the emergence and spread of three types of MRSA over 35 years . Classical multiresistant hospital-acquired MRSA were first noted in Australia in 1965 . By the end of the 1970s, strains of this type of MRSA were well established in the complex tertiary care hospitals in the capital cities on the eastern seaboard of mainland Australia . Characterized by resistance to beta-lactams, erythromycin, tetracycline, gentamicin, and trimethoprim-sulfamethoxazole, these strains have persisted and diversified genetically and have acquired a variety of new resistances . They have proven pathogenicity and are a prominent cause of hospital infection in the endemic institutions . More recently they have become endemic in some central state tertiary care hospitals . Community-acquired strains of MRSA first appeared in the north of Western Australia in the mid-1980s . Strains have subsequently appeared in the south of the state and in the two adjacent central states, and are more frequently isolated from Aboriginal patients . Although harboring few or no additional resistances apart from resistance to beta-lactams initially, these strains are also accumulating additional resistances . A different variety of community-acquired MRSA has recently been noted in eastern Australia . It has a similar antibiogram to the western strains, but an entirely different epidemiology, resembling that currently being experienced in parts of New Zealand, and associated with patients of south Pacific island origin.

Microb Drug Resist, 2000 Fall, 6(3), 213 - 21
Genetic relatedness of multidrug-resistant, methicillin (oxacillin)-resistant Staphylococcus aureus bloodstream isolates from SENTRY Antimicrobial Resistance Surveillance Centers worldwide, 1998; Diekema DJ et al.; We reviewed Staphylococcus aureus bloodstream infection isolates from SENTRY centers worldwide during 1998 to evaluate the molecular epidemiology of multiply drug-resistant methicillin (oxacillin)-resistant S . aureus (MDR-MRSA) . MDR-MRSA was defined as a S . aureus isolate with a MIC for oxacillin at >2 microg/ml and with four or more additional resistances . A total of 325 unique patient isolates of MDR-MRSA from five continents were analyzed using ribotyping and pulsed-field gel electrophoresis (PFGE) . The frequency of MDR-MRSA among all S . aureus BSI isolates ranged from only 2.2% in Canada to 35.6% in the Asia-Pacific region . Forty-eight ribotypes (RT) were distinguished, but over 80% of the isolates were contained within the 10 most prevalent RTs . The most common RT, RT 184.5, which included 30% of all MDR-MRSA, was found on four of five continents . PFGE provided superior discrimination and identified numerous clusters of possible clonal dissemination of MDR-MRSA within individual medical centers and between institutions that are in geographic proximity . In four instances, strains with indistinguishable PFGE patterns were found on more than one continent . The predominant PFGE subtype in South America (RT 893.5/Ia) was isolated from patients at centers in Brazil, Argentina, and Portugal, and closely related subtypes were isolated in Chile and Italy . There is great geographic variation in rates of methicillin- and multidrug-resistance among S . aureus bloodstream isolates worldwide . Although many MDR-MRSA strains group geographically, a few closely related epidemic strains have wide regional and even global range.

Microb Drug Resist, 2000 Fall, 6(3), 189 - 98
Molecular typing of methicillin-resistant Staphylococcus aureus by pulsed-field gel electrophoresis: comparison of results obtained in a multilaboratory effort using identical protocols and MRSA strains; Chung M et al.; Pulsed-field gel electrophoresis (PFGE) has become the gold standard of molecular methods in epidemiological investigations . In spite of its high resolving power, use of the method has been hampered by inadequate laboratory-to-laboratory reproducibility . In the project described here we have addressed this problem by organizing a multilaboratory effort in which the same bacterial strains (subtype variants of the Iberian and Brazilian methicillin-resistant Staphylococcus aureus--MRSA--clones) were analyzed by twenty investigators in thirteen different laboratories according to an indentical protocol, which is reproduced here in detail . PFGE patterns obtained were analyzed at a central laboratory in order to identify specific technical problems that produced substandard macrorestriction patterns . The results including the specific technical problems and their most likely causes are described in this communication . Also listed are seven major epidemic clones of MRSA which have been characterized by molecular fingerprinting techniques and the prototypes of which have been deposited at the American Type Culture Collection, from where they will be available for interested investigators for the purpose of typing MRSA isolates . It is hoped that this communication will contribute to the improvement of the reproducibility and technical/aesthetic quality of PFGE analysis.

Microb Drug Resist, 2000 Fall, 6(3), 173 - 88
Molecular epidemiology of methicillin-resistant Staphylococcus aureus strains: state of affairs and tomorrow' s possibilities; van Belkum A; Methicillin-resistant strains of Staphylococcus aureus (MRSA) have posed a clinical threat for nearly 40 years . During these years, an array of additional technologies suited for identification of MRSA below the species level has become available . The technologies, whether they assess phenotype or genotype, provide data that can be used for elucidation of the routes of dissemination of individual MRSA types . This review summarizes the current state of affairs with respect to the quality of the various laboratory techniques and includes descriptions of novel strategies such as binary typing and multilocus sequence typing (MLST) . Drawbacks of procedures will be compared, and the value of molecular typing in the elucidation of complex biological phenomena, such as epidemicity, carriage, and reduced vancomycin susceptibility, will be indicated . Means for integrated assessment of bacterial biology, epidemiology, and population structure will be discussed.

Pediatr Infect Dis J, 2000 Dec, 19(12), 1163 - 6
Current trends in community-acquired methicillin-resistant Staphylococcus aureus at a tertiary care pediatric facility; Hussain FM et al.; BACKGROUND: The prevalence of community-acquired methicillin-resistant Staphylococcus aureus (MRSA) infections increased at the University of Chicago Children's Hospital (UCCH) from 10 per 100,000 admissions from 1988 to 1990 to 259 per 100,000 admissions from 1993 to 1995 . Because this increase may have represented a one time occurrence or a limited disease outbreak, we updated our previous observations at UCCH in 1998 and 1999 to see whether this trend had continued . DESIGN: Prospective observational study . RESULTS: Twenty-three hospitalized children had an MRSA isolate during the 1-year study period . Ten were community-acquired, equally distributed between children with predisposing risk factors and those without . The overall prevalence of community-acquired MRSA was 208 per 100,000 admissions . Seven of the 10 community-acquired MRSA isolates were susceptible to clindamycin . Skin and soft tissue infections predominated among the children with a community-acquired MRSA isolate . Pulsed field gel electrophoresis of the 10 community-acquired MRSA isolates revealed 8 distinct patterns; these data suggest that multiple clones were circulating at UCCH . CONCLUSION: MRSA are no longer confined to children with established risk factors . The prevalence of community-acquired MRSA among children without identified risk factors is high in our institution.

J Indian Med Assoc, 2000 Jul, 98(7), 368 - 70
Potential infection hazards of stethoscopes; Sood P et al.; This study was conducted to assess the bacterial flora carried on stethoscopes used by medical personnel and to study the effect of disinfection of stethoscopes on the flora . In the 106 stethoscopes sampled, Gram-positive organisms were the most (60%) frequently isolated . Among them, Staphylococcus aureus accounted for 15.8% of the flora of which 21% were resistant to methicillin . The rate of isolation of S aureus and methicillin resistant S aureus (MRSA) was higher in critical care units . Disinfection was found to significantly reduce the bacterial count.

Can J Microbiol, 2000 Dec, 46(12), 1108 - 14
Assessing and analysing contamination of a dairy products processing plant by Staphylococcus aureus using antibiotic resistance and PFGE; Tondo EC et al.; A dairy product processing plant was studied for 2.5 years to examine contamination with Staphylococcus aureus and try to correlate the source of contamination . Cultures were submitted to an antibiotic susceptibility test (AST) and characterised by Pulsed-field Gel Electrophoresis (PFGE) analysis . Results showed that 35.2% (19/51) of food handlers were asymptomatic carriers of S . aureus, and that 90.4% (19/21) of raw milk sampled was contaminated . Staphylococcus aureus was isolated from only 10 samples among more than 3200 investigated dairy products . No S . aureus contamination was found on machinery . The AST analysis demonstrated sensitivity of tested S . aureus to oxacillin, cephalothin, vancomycin, gentamicin, and sulfamethoxazole/trimethoprim . AST analysis generated eight different phenotypic profiles, but did not allow us to identify the source of contamination in seven of ten final products . PFGE analysis proved to be a sensitive method as it generated 42 different DNA banding profiles among the 48 S . aureus investigated, demonstrating a lack of predominance of endemic strains in the plant, contrary to suggestions raised by antibiotic resistance typing . Based on PFGE genotyping, S . aureus strains isolated from four contaminated final products were similar to four S . aureus isolated from raw milk . Five final products contained S . aureus different from all other strains collected, and one showed similarity to a strain isolated from a food handler . These results suggest contamination by raw milk as the main source of contamination of the final dairy products.

Am J Perinatol, 2000, 17(8), 423 - 7
Maternal-fetal staphylococcal infections: a series report; Andre P et al.; The objective of this paper is to study the characteristics of maternal-fetal staphyloccocal infection . A retrospective study among 1,582 infants admitted consecutively to our neonatal intensive care unit was carried out from January 1995 through September 1998 . The antenatal history, and the clinical and bacteriological findings and outcome of the infants fulfilling maternal-fetal staphyloccocal infection were analysed . Among 122 (7.7%) maternal-fetal infection, 11 cases (8.9%) of congenital staphyloccal infections were diagnosed in 9 premature and 2 full-term babies . Antenatal invasive procedures were noted in 6 occasions (56%) . All the 11 infants developed respiratory and hemodynamic failure . Staphylococcus aureus was the most common organism encountered in maternal bacteriologic data (9/11, 82%) as well as on peripheral sites (9/11, 82%) and in blood cultures (7/11, 64%) performed in the infants . There was one case of methicillin-resistant Staphylococcus aureus . The outcome was favorable for 9 infants . Two very preterm neonates died within the first 72 hours of life . Mother-to-infant transmission of Staphylococcus should be suspected whenever invasive procedures are performed during pregnancy and in the presence of severe neonatal distress associated with an inflammatory response . Prompt and adapted antibiotic therapy allows a favourable outcome.

Schweiz Med Wochenschr, 2000, Suppl 125, 48S - 51S
{Residual bacterial contamination of rhinoscopes used in ENT consultation after cleaning with a pad impregnated with a disinfectant}; Kutter J et al.; INTRODUCTION: The duration of the official disinfection procedure of a Hopkins rhinoscope agreed by the hospital hygiene authorities may be a handicap in a busy ENT consultation . A shortened procedure is sometimes used, but without risk assessment . OBJECTIVE: To determine the risk of contamination of the endoscope used for rhinoscopy after simple manual cleaning with a pad impregnated with a disinfectant solution (Neosabenyl) . PATIENTS AND METHOD: In 60 patients undergoing rhinoscopy at our ENT policlinic, a nasal swab as well as the endoscope were examined bacteriologically . The nasal physiological flora and specifically Staphylococcus aureus were semiquantitatively analysed on each specimen . In 50 patients, the rhinoscopes were simply cleaned with an impregnated pad, whereas in 10 patients the official disinfection procedure with glutaraldehyde was applied . RESULTS: 25 out of the 50 endoscopes (50%) which were manually cleaned with the impregnated pad, were still contaminated with bacteria . Among the 12 (20%) identified healthy carriers of S . aureus, 7 (58%) showed a rhinoscope still contaminated with S . aureus after cleaning with the pad . The overall risk of contaminating the following patient with S . aureus is 14% . None of the 10 endoscopes cleaned and disinfected with glutaraldehyde were contaminated . CONCLUSIONS: Simple manual cleaning and disinfection with an impregnated pad is insufficient and carries the risk of contaminating the following patient . This emphasises the need to follow the recommended cleaning and disinfection procedures even in a small or busy practice.

Schweiz Med Wochenschr, 2000, Suppl 125, 41S - 43S
{Infectious aspects of Wegener's granulomatosis}; Rusterholz D et al.; INTRODUCTION: Because of manifestation of Wegener's granulomatosis in the upper respiratory tract the ENT-specialist is often initially involved in diagnosis . Recent research results suppose the chronic nasal carriage of Staphylococcus aureus triggering relapse rate in Wegener's granulomatosis . The adequate therapy of this bacteria as chronic nasal carriage may reduce the number of relapses in patients with Wegener's granulomatosis in remission . PATIENT: An illustrative case report shows the positive effect of prolonged treatment with cotrimoxazole in a 49-year-old male with a second relapse of Wegener's granulomatosis . RESULTS: The prolonged treatment of cotrimoxazole reduced the dose of cyclophosphamid and glucocorticoids which show long-term side effects . DISCUSSION: 15 years ago a positive effect of cotrimoxazole to Wegener's granulomatosis was discussed . Later immunological and clinical studies confirmed this fact . Prolonged treatment with cotrimoxazole seems to reduce the number of relapses in patients with this chronic disease . Corresponding with our case reduction of the systemic therapy with cyclophosphamid and glucocorticoids is possible.

Infect Control Hosp Epidemiol, 2000 Dec, 21(12), 761 - 4
An outbreak of pyodermas among neonates caused by ultrasound gel contaminated with methicillin-susceptible Staphylococcus aureus; Weist K et al.; OBJECTIVE: To investigate an outbreak of methicillin-susceptible Staphylococcus aureus (MSSA) infections in a neonatal clinic . DESIGN: Prospective chart review, environmental sampling, and genotyping by two independent methods: pulsed-field gel electrophoresis (PFGE) and randomly amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) . A case-control study was performed with 31 controls from the same clinic . SETTING: A German 1,350-bed tertiary-care teaching university hospital . RESULTS: There was a significant increase in the incidence of pyodermas with MSSA; 10 neonates in good physical condition with no infection immediately after birth developed pyodermas . A shared spatula and ultrasound gel were the only identified infection sources . The gel contained MSSA and was used for hip joint sonographies in all neonates . PFGE and RAPD-PCR patterns from 6 neonates and from the gel were indistinguishable and thus genetically related clones . The case-control study revealed no significant risk factor with the exception of cesarean section (P=.006) . The attack rate by days of hip-joint sonography between April 15 and April 27, 1994, was 11.8% to 40% . CONCLUSIONS: Inappropriate hygienic measures in connection with lubricants during routine ultrasound scanning may lead to nosocomial S . aureus infections of the skin . To our knowledge this source of S . aureus infections has not previously been described.

Kansenshogaku Zasshi, 2000 Nov, 74(11), 966 - 72
Susceptibility to vancomycin of methicillin-resistant Staphylococcus aureus isolated in a university hospital in Japan; Mori N et al.; Intravenous vancomycin was approved in 1991 in Japan and has been widely used for treatment of infections caused by methicillin-resistant Staphylococcus aureus (MRSA) . Consequently, ever since the initial discovery of vancomycin intermediate-resistant S . aureus in Japan, the vancomycin resistance of this organism has been a great concern in clinical settings . We investigated whether vancomycin resistance had emerged in MRSA isolated in our hospital since the approval of the use of intravenous vancomycin . Vancomycin susceptibility was evaluated on the basis of minimum inhibitory concentrations determined by the agar dilution method and a heterogeneous resistance examination . The median minimum inhibitory concentration of the 69 MRSA strains isolated in 1988 and the 74 isolated in 1998 was 0.75 microgram/ml and 1.0 microgram/ml, respectively (p < 0.001), however, all of the strains were classified in the susceptible group . None of them was an MRSA heterogeneously resistant to vancomycin (hetero-VRSA), which has been defined as a strain having a 1/10(6) or greater heterogeneously resistant subpopulation to vancomycin . In another set of investigations, no hetero-VRSA were found among 12 other MRSA strains isolated after intravenous administration of vancomycin for 14 or more days (range: 14 to 77 days) . We conclude that while the use of intravenous vancomycin may have slightly lowered the vancomycin susceptibility of MRSA in our hospital, the decrease in so small that it may not be significant clinically . In addition, no hetero-VRSA were found in our hospial.

Cutis, 2000 Dec, 66(6), 447 - 52
Septic embolization arising from infected pseudoaneurysms following percutaneous transluminal coronary angioplasty: a report of 2 cases and review of the literature; Izumi AK et al.; Septic embolization arising from infected pseudoaneurysms following percutaneous transluminal coronary angioplasty (PTCA) constitutes a distinct clinical and histopathologic entity . Pseudoaneurysms are a potential complication of both cardiac catheterization and PTCA . Repeated or prolonged catheterization increases the risk of bacterial seeding of these sites, resulting in septic embolization . Characteristic clinical features include fever within 2 to 5 days, unilateral embolic disease, and Staphylococcus aureus septicemia . Culture and examination of biopsy specimens of the embolic lesions typically demonstrate gram-positive microorganisms . We describe 2 patients presenting with ipsilateral palpable purpura, petechiae, and livedo reticularis caused by septic emboli from infected pseudoaneurysms . The recommended treatment includes administration of appropriate systemic antibiotics and surgical resection of the infected pseudoaneurysm . Both cholesterol and septic emboli should be considered in the differential diagnosis of ipsilateral embolic disease induced by invasive vascular procedures.

Int J Antimicrob Agents, 2000 Nov, 16 Suppl 1, S39 - 42
Gram positive infection in trauma patients: new strategies to decrease emerging Gram-positive resistance and vancomycin toxicity; Ginzburg E et al.; Bacterial resistance to antibiotics has become a serious problem in medicine . Particularly worrisome is the increasing incidence of multi-resistant organisms such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) . Not surprisingly, in view of the high incidence of life-threatening infections and heavy antibiotic use, resistance has become very frequent and problematic in intensive care units . The standard approach for the treatment of MRSA is vancomycin or teicoplanin . Long-term therapeutic and unrestricted prophylactic use of vancomycin has given rise to VRE which in turn may lead to the emergence of vancomycin-resistant S . aureus (VRSA) through plasmid mediated transmission . In order to reduce the incidence of VRE and to avoid the emergence of VRSA, vancomycin use should be restricted and alternative antibiotic strategies should be developed . Using those antibiotics to which MRSA are still generally sensitive, perhaps in combination with new ones, such as, quinupristin/dalfopristin, should be entertained . We performed a retrospective review of the Gram-positive infections in our Level 1 Trauma Center Intensive Care Unit, and an analysis of the resistance patterns of the NMSA infections showed that additional resistance rarely develops within less than 5 days . We then designed a new strategy for the treatment of MRSA infections . This strategy consists of the sequential use of a range of antibiotics with activity against MRSA in short 5-7 day pulses until the full clinical course is completed . Studies validating the benefit of this approach are currently in preparation.

Int J Antimicrob Agents, 2000 Nov, 16 Suppl 1, S31 - 4
Vancomycin treatment failures in Staphylococcus aureus lower respiratory tract infections; Moise PA et al.; We reviewed all patients with Staphylococcus aureus lower respiratory tract infections treated with vancomycin at our institution in 1998, to see how this antimicrobial is performing . We found that approximately 40% of evaluable patients were considered treatment failures, even though the S . aureus was still reported as being susceptible to vancomycin . We report in detail two example patients that failed to respond clinically to vancomycin and summarize the clinical characteristics of the 23 additional patients that failed . The first case was treated four times in the intensive care unit with vancomycin . Each course, after approximately 14 days therapy, the vancomycin was discontinued and his infection relapsed soon thereafter . The second was treated with vancomycin for 10 days initially . She relapsed, was restarted on vancomycin once more, but her condition deteriorated, and she died of refractory sepsis 20 days after admission . The cost of care for each patient ranged from $50,000 to over $100,000 . With trends such as these, alternative therapies are needed to control resistant Gram-positive infections.

N Engl J Med, 2001 Jan 4, 344(1), 11 - 6
Nasal carriage as a source of Staphylococcus aureus bacteremia . Study Group; von Eiff C et al.; BACKGROUND: The consequences of infection with Staphylococcus aureus can be severe, so strategies for prevention are important . We examined S . aureus isolates from blood and from nasal specimens to determine whether the organisms in the bloodstream originated from the patient's own flora . METHODS: In a multicenter study, swabs for culture were obtained from the anterior nares of 219 patients with S . aureus bacteremia . A total of 723 isolates were collected and genotyped . In a second study, 1640 S . aureus isolates from nasal swabs were collected over a period of five years and then compared with isolates from the blood of patients who subsequently had S . aureus bacteremia . RESULTS: In the multicenter study of S . aureus bacteremia, the blood isolates were identical to those from the anterior nares in 180 of 219 patients (82.2 percent) . In the second study, 14 of 1278 patients who had nasal colonization with S . aureus subsequently had S . aureus bacteremia . In 12 of these 14 patients (86 percent), the isolates obtained from the nares were clonally identical to the isolates obtained from blood 1 day to 14 months later . CONCLUSIONS: A substantial proportion of cases of S . aureus bacteremia appear to be of endogenous origin since they originate from colonies in the nasal mucosa . These results provide support for strategies to prevent systemic S . aureus infections by eliminating nasal carriage of S . aureus.

J Clin Microbiol, 2001 Jan, 39(1), 328 - 31
Binary typing of Staphylococcus aureus strains through reversed hybridization using digoxigenin-universal linkage system-labeled bacterial genomic DNA; van Leeuwen W et al.; A novel binary typing (BT) procedure, based on reversed hybridization of digoxigenin-universal linkage system-labeled bacterial DNA to strip-immobilized probes, is presented . Chromogenic detection of hybrids was performed . Staphylococcus aureus isolates (n = 20) were analyzed to establish the feasibility of BT . A technically simple and fast procedure has been developed for application in routine microbiology laboratories.

J Clin Microbiol, 2001 Jan, 39(1), 86 - 9
International multicenter evaluation of latex agglutination tests for identification of Staphylococcus aureus; van Griethuysen A et al.; A newly marketed rapid agglutination kit for the identification of Staphylococcus aureus, Slidex Staph Plus (bioMerieux), was compared to Staphaurex Plus (Murex Diagnostics) and Pastorex Staph-Plus (Sanofi Diagnostics Pasteur) . The study took place in three clinical microbiology laboratories in three different European countries . A total of 892 staphylococcal isolates, including 278 methicillin-sensitive S . aureus (MSSA) isolates, 171 methicillin-resistant S . aureus (MRSA) isolates, and 443 coagulase-negative staphylococcal isolates, were analyzed . The sensitivities (MSSA/MRSA) and specificities, respectively, were 98 . 2% (98.9%/97.1%) and 98.9% for Slidex Staph Plus, 98.2% (98.2%/98 . 2%) and 96.2% for Staphaurex Plus, and 98.7% (98.6%/98.8%) and 95.7% for Pastorex Staph Plus . The specificity of the Slidex Staph Plus kit was statistically significantly higher than the specificities of Staphaurex Plus and Pastorex Staph-Plus . The Slidex Staph Plus is a very reliable test for the identification of S . aureus.

J Clin Microbiol, 2001 Jan, 39(1), 53 - 6
Comparison of the Vitek Gram-Positive Susceptibility 106 card and the MRSA-screen latex agglutination test for determining oxacillin resistance in clinical bloodstream isolates of Staphylococcus aureus; Yamazumi T et al.; The Vitek automated susceptibility testing system with a modified Gram-Positive Susceptibility (GPS) 106 Card (bioMerieux Vitek, Inc., Hazelwood, Mo.) and a rapid slide latex agglutination test (MRSA-Screen; Denka Seiken Co., Ltd., Tokyo, Japan) were evaluated for their ability to detect oxacillin resistance in Staphylococcus aureus . The oxacillin-salt agar screen (OS) test, the reference broth microdilution method, and the detection of the mecA gene by PCR were compared with the commercial products . A total of 200 contemporary (1999) bloodstream infection isolates were collected from the SENTRY Antimicrobial Surveillance Program, representing diverse geographic areas throughout the world . Among the 99 mecA-positive isolates, 3 isolates were found negative by the MRSA-Screen . Another two isolates did not grow on OS plates and had MICs of 0.5 and 2 microg/ml with the Vitek GPS card . All 101 mecA-negative isolates were also found negative by the MRSA-Screen and were categorized as susceptible by the GPS card . Overall, the MRSA-Screen, GPS card, and OS test had sensitivities of 96.9, 98.0, and 98.0% and specificities of 100.0, 100.0, and 98.0%, respectively . MRSA-Screen was a rapid (</=15 min) and simple test to perform, and the GPS card provided results in <8 h . Both methods were sensitive and specific for detecting staphylococcal oxacillin resistance in the clinical microbiology laboratory.

Braz J Infect Dis, 2000 Dec, 4(6), 296 - 300
The Effect of post-discharge surveillance and control strategies on the course of a Staphylococcus aureus outbreak in a newborn nursery; Couto RC et al.; This study was carried out to evaluate changes in infection rates following the adoption of three measures for controlling a Staphylococcus aureus outbreak in a nursery . In late April and early May, 1995, an outbreak of pustular dermatitis and conjunctivitis caused by S . aureus was documented . Case patients were identified by both in-hospital and post-discharge surveillance . In-hospital surveillance included daily review of data gathered by the hospital's infection control committee; use of microbiology laboratory results; requesting charts for antibiotic prescriptions; nurses' notes, and ward rounds surveillance as indicators of S . aureus infection (SAi) . Post-discharge surveillance was done by telephone survey around the 30th day after a baby's birth date . During the epidemic period, reinforcement of handwashing, daily bathing, and cord care with antiseptics combined with a cohort system of admissions, and nasal mupirocin ointment were introduced sequentially in an attempt to control the outbreak . The efficacy of these three strategies was measured through the decrease of SAi rates, detected by both in-hospital and post-discharge surveillance . A total of 5,639 babies were included in the study . In-hospital surveillance information was obtained from all patients and post-discharge surveillance in 3,506 (62.7%) patients . A total of 534 SAi were detected during the study, 47 in-hospital and 487 at post-discharge surveillance . A progressive decrease in the SAi rates could be observed after the institution of the control strategies, both in-hospital (7.6% to 0.5%) and after discharge (68.9% . to 11.7%) . During the study period, the rates of infection detected in out-patients were consistently higher than those diagnosed in-hospital . Improving handwashing and nasal mupirocin ointment seem to be more effective than cohort admissions and bath and cord care with antiseptics . The high SAi rates detected only after discharge from the hospital indicate that data from post-discharge surveillance should be included to estimate the true rates of infections in newborns.

Nat Biotechnol, 2001 Jan, 19(1), 62 - 5
Interference-based detection of nucleic acid targets on optically coated silicon; Jenison R et al.; Sequence-specific detection of polynucleotides typically requires modified reporter probes that are labeled with radioactive, fluorescent, or luminescent moieties . Although these detection methods are capable of high sensitivity, they require instrumentation for signal detection . In certain settings, such as clinical point of care, instrumentation might be impractical or unavailable . Here we describe a detection approach in which formation of a nucleic acid hybrid is enzymatically transduced into a molecular thin film that can be visually detected in white light . The system exploits a flat, optically coated silicon-based surface to which capture oligonucleotides are covalently attached . The optimized system is capable of detection of nucleic acid targets present at sub-attomole levels . To supplement visual detection, signals can be quantitated by a charge-coupled device . The design and composition of the optical surface, optimization of immobilization chemistry for attachment of capture probes, and characterization of the efficiency of the hybridization process are presented . We describe the application of this system to detection of a clinically relevant target, the mecA gene present in methicillin-resistant Staphylococcus aureus.

J Bacteriol, 2001 Jan, 183(2), 468 - 75
In Staphylococcus aureus, fur is an interactive regulator with PerR, contributes to virulence, and Is necessary for oxidative stress resistance through positive regulation of catalase and iron homeostasis; Horsburgh MJ et al.; The Staphylococcus aureus genome encodes three ferric uptake repressor (Fur) homologues: Fur, PerR, and Zur . To determine the exact role of Fur in S . aureus, we inactivated the fur gene by allelic replacement using a tetracycline resistance cassette, creating strain MJH010 (fur) . The mutant had a growth defect in rich medium, and this defect was exacerbated in metal-depleted CL medium . This growth defect was partially suppressed by manganous ion, a metal ion with known antioxidant properties . This suggests that the fur mutation leads to an oxidative stress condition . Indeed, MJH010 (fur) has reduced levels of catalase activity resulting from decreased katA transcription . Using a katA-lacZ fusion we have determined that Fur functions, either directly or indirectly, as an iron-dependent positive regulator of katA expression . Transcription of katA is coregulated by Fur and PerR, since in MJH010 (fur) transcription was still repressed by manganese while transcription in MJH201 (fur perR) was unresponsive to the presence of iron or manganese . Siderophore biosynthesis was repressed by iron in 8325-4 (wild-type) but in MJH010 (fur) was constitutive . A number of putative Fur-regulated genes were identified in the incomplete genome databases using known S . aureus Fur box sequences . Of those tested, the sstABCD and sirABC operons and the fhuD2 and orf4 genes were found to have Fur-regulated expression . MJH010 (fur) was attenuated (P<0.04) in a murine skin abscess model of infection, as was double-mutant MJH201 (fur perR) (P<0.03) . This demonstrates the importance in vivo of iron homeostasis and oxidative stress resistance regulation in S . aureus.

Nat Biotechnol, 2001 Jan, 19(1), 66 - 70
Lysostaphin expression in mammary glands confers protection against staphylococcal infection in transgenic mice; Kerr DE et al.; Infection of the mammary gland, in addition to causing animal distress, is a major economic burden of the dairy industry . Staphylococcus aureus is the major contagious mastitis pathogen, accounting for approximately 15-30% of infections, and has proved difficult to control using standard management practices . As a first step toward enhancing mastitis resistance of dairy animals, we report the generation of transgenic mice that secrete a potent anti-staphylococcal protein into milk . The protein, lysostaphin, is a peptidoglycan hydrolase normally produced by Staphylococcus simulans . When the native form is secreted by transfected eukaryotic cells it becomes glycosylated and inactive . However, removal of two glycosylation motifs through engineering asparagine to glutamine codon substitutions enables secretion of Gln(125,232)-lysostaphin, a bioactive variant . Three lines of transgenic mice, in which the 5'-flanking region of the ovine beta-lactoglobulin gene directed the secretion of Gln(125,232)-lysostaphin into milk, exhibit substantial resistance to an intramammary challenge of 104 colony-forming units (c.f.u.) of S . aureus, with the highest expressing line being completely resistant . Milk protein content and profiles of transgenic and nontransgenic mice are similar . These results clearly demonstrate the potential of genetic engineering to combat the most prevalent disease of dairy cattle.

J Biol Chem, 2001 Mar 23, 276(12), 8875 - 83 Epub 2000 Dec 21.
Significant interference with hepatitis B virus replication by a core-nuclease fusion protein; Beterams G et al.; Hepatitis B virus (HBV), a small DNA containing virus that replicates via reverse transcription, causes acute and chronic B-type hepatitis in humans . The limited success of current therapies for chronic infection has prompted exploration of alternative strategies . Capsid-targeted viral inactivation is a conceptually powerful approach that exploits virion structural proteins to target a degradative enzyme specifically into viral particles . Its principal feasibility has been demonstrated in retroviral model systems but not yet for a medically relevant virus outside the retrovirus family . Recently, we found that C proximal fusion to the HBV capsid protein of the Ca(2+)-dependent nuclease (SN) from Staphylococcus aureus yields a chimeric protein, coreSN, that in Escherichia coli coassembles with the wild-type capsid protein into particles with internal SN domains . Here we show that, in HBV co-transfected human hepatoma cells, less than 1 coreSN protein per 10 wild-type core protein subunits reduced titers of enveloped DNA containing virions by more than 95% . The antiviral effect depends on both an enzymatically active SN and on the core domain . CoreSN does not block assembly of RNA containing nucleocapsids but interferes with proper synthesis of viral DNA inside the capsid, or leads to rapid DNA degradation . Our data suggest an intracellular nuclease activation that, owing to the characteristics of HBV morphogenesis, is nonetheless highly virus specific . HBV may therefore be particularly vulnerable to the capsid-targeted viral inactivation approach.

J Antibiot (Tokyo), 2000 Oct, 53(10), 1045 - 52
SAR studies of anti-MRSA non-zwitterionic 3-heteroarylthiocephems; Glinka TW et al.; SAR studies in a series of 3-heteroarylthio substituted cephalosporins established that high activity against methicillin-resistant Staphylococcus aureus (MRSA) can be achieved with various heteroaryl substituents . Early results showed that highly lipophilic 3-heteroarylthio substituents, which were necessary for anti-MRSA activity, caused high affinity of such cephems toward serum proteins . Our earlier published efforts described discovery of zwitterionic cephems MC-02,331 and RWJ-54428 (MC-02,479), where serum binding was reduced by employing basic, positively charged functionalities attached to the 3-heteroarylthio substituent . In order to avoid low solubility problems associated with most such zwitterionic cephalosporins a wide variety of non-basic heteroaryl substituents was tested (non-zwitterionic cephems are more easily formulated as water soluble sodium salts for intravenous administration) . Considerable reduction in serum binding was obtained in some analogs while maintaining high anti-MRSA potency.

J Antibiot (Tokyo), 2000 Oct, 53(10), 1028 - 37
Cephems: fifty years of continuous research; Bryskier A; Since 1964, seven waves of parenteral cephems have been reported . All of them were designed to meet medical needs . The first (group I) and the third (group III) waves were very successful and drugs belonging to group III are widely used in the treatment of severe infections . A new series of compounds (group VII), with a new compound underdevelopment was designed for the treatment of Staphylococcus aureus strain resistant to methicillin but also to glyco- and lipoglycopeptides . By modifying the substituent at position 3 and 7 of the cephems rings optimal moieties have been fixed leading to potent anti-Gram-positive drugs . Alterations of substituents are still in progress to obtain optimal anti-Gram-positive (anti-MRSA) compounds . The first oral cephem cephalexin was introduced in clinical practice in 1967 . Since this time, many esterified and non-esterified cephems have been synthesized and introduced in clinics . There are two groups of compounds, alpha-amino and non-alpha-amino cephems which are classified in six groups according to their chemical structure . The absorption route was explored and three transporting systems have been described according to the physico-chemical properties of these compounds, in addition prodrugs are passively absorbed.

Trans R Soc Trop Med Hyg, 2000 Sep-Oct, 94(5), 504 - 7
Nasal carriage and antibiotic resistance of Staphylococcus aureus isolates from hospital and non-hospital personnel in Abha, Saudi Arabia; Alghaithy AA et al.; The prevalence of nasal carriage of Staphylococcus aureus, antibiograms and prevalence of methicillin-resistant S . aureus (MRSA) were studied in 1999 among healthy hospital and non-hospital personnel in Abha, Saudi Arabia . S . aureus was isolated from 26.1% of 299 adults in the community and 25.4% of 279 hospital personnel . No isolate was resistant to vancomycin . Antibiotic resistance rates, for all other antibiotics tested except cephalothin, were significantly higher for strains from hospital personnel (P values < 0.001-0.04) compared to non-hospital adults . The antibiograms were also compared with those of 140 clinical isolates . The rates of resistance of the inpatient strains to all the antibiotics tested were significantly higher than those of hospital nasal carrier strains (P < 0.001-0.05) . MRSA was isolated, respectively, from 5.1% and 18.3% of non-hospital and hospital carriers; MRSA carriage rates were 1.3% and 4.7%, respectively, for non-hospital and hospital carriers, and 61% of S . aureus isolates from infected patients were MRSA . Only 8% of non-hospital but 44% of hospital carrier strains were multiply resistant (P < 0.001) . Multiple resistance among inpatient strains (89%) was significantly higher than that among hospital nasal strains (44%) (P < 0.001) . Such rates of multiple resistance and endemic MRSA prevalence among healthy carriers (11%) at a much higher rate than those reported in the literature should raise concern in a region with unrestricted availability of antibiotics.

J Chemother, 2000 Nov, 12 Suppl 5, 40 - 55
Does surgical prophylaxis with teicoplanin constitute a therapeutic advance?
Mini E, Nobili S, Periti P.
Antibiotic prophylaxis has become standard care not only in operations characterized by high infection rates but also in the vast majority of clean surgical procedures, including those that use foreign materials, grafts or prosthetic devices as well as non-implant surgery . While use of antibiotics in clean implant surgery is undisputed, it is still controversial in clean non-implant surgery . As antibiotic prophylaxis should be directed against expected pathogens, the glycopeptides are considered suitable alternative antibiotics to first and second generation cephalosporins in clean surgical procedures associated with a high risk of wound infections due to Gram-positive bacteria, including methicillin-resistant, and for patients allergic to beta-lactam antibiotics . In deciding whether to use a glycopeptide for prophylaxis, the current wound infection rates with methicillin-resistant Staphylococcus aureus and methicillin-resistant Staphylococcus epidermidis at single institutions need to be considered, to limit the use of glycopeptides to wards where the incidence of methicillin resistance is high . Of the two available glycopeptides, teicoplanin may be preferable to vancomycin for peri-operative prophylaxis because of its excellent tissue penetration, as indicated by the large volume of distribution, lower toxicity, and particularly long half-life, allowing single-dose administration in several surgical procedures . Clinical trials with teicoplanin prophylaxis in several types of clean surgical procedures including orthopedic, cardiac, vascular and dental operations, have shown it to be efficacious . This review focuses on results from clinical studies with this glycopeptide as prophylaxis in clean surgery.

J Chemother, 2000 Nov, 12 Suppl 5, 26 - 33
Teicoplanin in the treatment of serious infection; Schaison G et al.; The merits and dosing regimens for teicoplanin in the treatment of endocarditis, bacteremia, bone and joint infections, pediatric use, non in-patient use and in the ICU are discussed . Teicoplanin has several advantages over vancomycin in the treatment of serious infections: long half-life, lower nephrotoxicity, and lack of requirement for serum assays . The recommended regimen for teicoplanin is three loading doses of 6 mg/kg (400 mg) q12h, then 6 mg/kg (400 mg) q24h . There is no significant difference in efficacy between teicoplanin and vancomycin when at least 6 mg/kg teicoplanin is used or, in the case of staphylococcal endocarditis, it is given in combination with another antimicrobial . Teicoplanin is effective and safe in staphylococcal infections including endocarditis, osteomyelitis and septic arthritis . The once daily or alternate daily dosage allows home administration of treatment of infections caused by Staphylococcus aureus, including methicillin-resistant strains and enterococci with appreciable savings in hospital costs and improvement in the quality of life.

Vet Res, 2000 Nov-Dec, 31(6), 603 - 9
Decreased neutrophil bactericidal activity during phagocytosis of a slime-producing Staphylococcus aureus strain; Barrio B et al.; Phagocytosis and intracellular killing by bovine polymorphonuclear leukocytes (PMN) are important host defence mechanisms against mastitis caused by Staphlylococcus aureus . We compared the phagocytosis and overall killing of a non slime-producing (NSP) S . aureus and its slime-producing (SP) variant by blood PMN, using an in vitro bacteriological assay . Seven clinically healthy Holstein-Friesian dairy cows in mid-lactation stage were used for this purpose . The percentages of overall killing for the NSP and SP variant were 34+/-3% and 21+/-4% (P < 0.05) and the corresponding percentages of phagocytosis were 40+/-4% and 31+/-4%, respectively . A significant positive correlation (r = 0.79; P < 0.001) was found between phagocytosis and overall killing . These results suggest that the presence of slime was responsible for a decreased phagocytic ingestion and overall killing.

J Med Microbiol, 2000 Dec, 49(12), 1109 - 17
Contamination of expressed human breast milk with an epidemic multiresistant Staphylococcus aureus clone; Novak FR et al.; Nosocomial infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are a major cause of outbreaks in intensive care units . Infants make up a sector of the population that presents a high risk for MRSA infections . Mother-to-infant transmission has been indicated as a possible cause of MRSA infections in neonates . The occurrence and characteristics of MRSA in samples of banked human milk were investigated by selective culture, antibiogram and pulsed-field gel electrophoresis . MRSA contamination was found in 11% of 500 samples of expressed, fresh-frozen milk from 500 different donors at five Brazilian milk banks . The great majority of the contaminated samples passed breast milk quality control criteria for dispensing as raw milk under Brazilian and American guidelines . Most of the MRSA isolates belonged to the Brazilian epidemic clone, which is reported to be widespread in several Brazilian states, in Argentina and in Portugal . It is concluded that expressed breast milk can be a reservoir of multiresistant S . aureus epidemic clones . Studies are necessary to assess the source of contamination and potential role of MRSA-contaminated milk in the transmission of MRSA to neonates.

J Med Microbiol, 2000 Dec, 49(12), 1103 - 7
Co-transfer of plasmids in association with conjugative transfer of mupirocin or mupirocin and penicillin resistance in methicillin-resistant Staphylococcus aureus; Pawa A et al.; Two distinct strains of methicillin-resistant Staphylococcus aureus (MRSA) isolated from patients in a dermatology ward were also resistant to mupirocin . The mupirocin resistance plasmids from both strains were indistinguishable by EcoRI and HindIII restriction digest analysis, except for the presence of genes apparently mediating penicillinase production in some transconjugants . Conjugative transfer of the plasmid mediating mupirocin resistance from one of these strains to a recipient S . aureus was accompanied in some cases by co-transfer of plasmids mediating resistance to tetracycline or erythromycin; in some instances a plasmid which possessed no apparent resistance markers was also transferred . The second strain demonstrated conjugative transfer of penicillin and mupirocin resistance as well as transfer of a plasmid mediating gentamicin resistance, but transfer of erythromycin resistance was not apparently plasmid-mediated.

Laryngoscope, 2000 Dec, 110(12), 2085 - 8
Effects of beta-toxin of Staphylococcus aureus on ciliary activity of nasal epithelial cells; Kim CS et al.; OBJECTIVES: To investigate the in vitro effects of staphylococcal beta-toxin on ciliary activity and the in vivo effects on sinusitis induction . STUDY DESIGN: The in vitro effects of staphylococcal beta-toxin on ciliary activity were investigated at different concentrations and exposure times . Experimental sinusitis was induced in rabbits with application of beta-toxin and confirmed 7 days later . METHODS: Ciliated epithelial cells were taken from the maxillary sinus mucosa of 10 rabbits . Five culture dishes from each rabbit were used for the experimental group, and one culture dish from each rabbit was used for the control group . In the experimental group, ciliary beat frequency (CBF) was measured at concentrations of 0.1, 1, 2, 5 and 10 U/mL of beta-toxin using a video-computerized analysis technique, while in the control group, culture medium containing no toxin was used . CBF was measured 1, 2, 4, 6, 8, 12, 24, and 48 hours after administration of beta-toxin . To induce experimental sinusitis, 2 U/mL of beta-toxin was percutaneously applied to the maxillary sinus of 10 rabbits without occlusion of the natural ostium, while normal saline was percutaneously applied to the right-side maxillary sinus of 4 rabbits in the control group . At 7 days, mucosal membranes were taken from the inferomedial wall of the maxillary sinus for light microscopic study . RESULTS: CBF dropped significantly after an 8-hour incubation at 2, 5, and 10 U/mL of beta-toxin . No ciliary activity was observed after a 24-hour incubation at 2 and 5 U/mL and a 12-hour incubation at 10 U/mL of beta-toxin . Mucoid, purulent discharge was observed in the maxillary sinuses of the beta-toxin-applied group . Prominent epithelial disruption and infiltration of inflammatory cells into the epithelium and lamina propria were observed in the beta-toxin-applied group . CONCLUSIONS: Staphylococcal beta-toxin may reduce ciliary activity and induce sinusitis without occlusion of the natural ostium of the maxillary sinus in rabbits This study provides another animal model of sinusitis for understanding the pathogenesis of sinusitis induced by bacterial exotoxins.

Anal Chem, 2000 Dec 1, 72(23), 5761 - 5
Immunoassay of the MRSA-related toxic protein, leukocidin, with scanning electrochemical microscopy; Kasai S et al.; Scanning electrochemical microscopy (SECM) was applied to the immunoassay of leukocidin, which is a toxic protein produced by methicillin-resistant Staphylococcus aureus (MRSA), with the intention of developing and early diagnostic for MRSA infection . An antibody-chip for leukocidin was prepared by self-assembling of anti-leukocidin on a protein A-coated glass substrate . A sample solution containing leukocidin was spotted onto the antibody-chip, followed by labeling with horseradish peroxidase (HRP) via a sandwich method . The reduction current of the oxidized form of ferrocenylmethanol generated by the HRP reaction was monitored to view SECM images of the spot of captured leukocidin . The amplitude of reduction current depended on the concentrations of sample solutions used for making spots . This SECM-based immunoassay detects as low as 5.25 pg mL(-1) leukocidin.

Bioorg Med Chem Lett, 2000 Dec 4, 10(23), 2675 - 8
Potent in vitro methicillin-resistant Staphylococcus aureus activity of 2-(1H-indol-3-yl)quinoline derivatives; Hoemann MZ et al.; A novel structural class of antibacterials, 2-(1H-indol-3-yl)quinolines, effective against methicillin-resistant Staphylococcus aureus (MRSA), was discovered from a combinatorial library . A structure-activity relationship (SAR) study was conducted to determine the pharmacophore and increase the potency of these compounds . Compounds were prepared that had minimum inhibitory concentrations (MICs) < 1.0 microg/mL against MRSA and retained activity against two strains of glycopeptide intermediate-resistant S . aureus (GISA).

Indian J Pathol Microbiol, 1999 Oct, 42(4), 441 - 6
Nasal carriage of methicillin resistant Staphylococcus aureus in a cardiovascular tertiary care centre and its detection by Lipovitellin Salt Mannitol Agar; Verghese S et al.; Ecological niches of Staphylococcus aureus are the anterior nares . Carriage of Staphylococcus aureus in the nose appears to play a key role in the epidemiology and pathogenesis of infection . Numerous studier have shown that elimination of nasal carriage using Mupirocin also eliminated hand carriage and the spread of infections in hospitals . Lipovitellin-Salt-Mannitol Agar was used for screening, isolation and presumptive identification of Staphylococcus aureus from nasal carriers . From November; 97 to August'98, 724 nasal swabs were cultured and 18.23% of health care workers were found to be nasal carriers of Staphylococcus aureus . Of these 12.15% were carriers of MRSA . The carrier rate was highest in December' 97 (32.07%) . All MRSA carriers were treated with local application of Mupirocin for three days . A study of the antibiogram of the clinical isolates during the corresponding period showed 100% susceptibility of MRSA to Vancomycin . Susceptibility of MRSA to Clindamycin, Netilmycin, Rifampicin & Ofloxacin was 86.6%, 69.5%, 66% & 64.7% respectively.

Indian J Pathol Microbiol, 1999 Oct, 42(4), 421 - 6
Community acquired methicillin resistant Staphylococcsus aureus: a new threat for hospital outbreaks?
Gupta N, Prakash SK, Malik VK, Mehndiratta PL, Mathur MD.
Methicillin resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen . Recently, there have been reports of increasing prevalence of MRSA in the community . We here report an outbreak of post operative wound sepsis by MRSA in the surgical ward of LN hospital . A surveillance study for MRSA was undertaken in the corresponding surgical ward, operation theater and OPD and the source of this outbreak was traced to an outdoor patient with community acquired MRSA infection . A total of 320 clinical and environmental samples were screened for MRSA . Seventy (21.8%) S . aureus were obtained, of which 12.8% were resistant to methicillin . 14% of the MRSA infections were from the community . Nasal carriage rates of MRSA in the screened hospital staff and admitted patients were 5.8% and 4.3% respectively . None of the environmental sites sampled yielded MRSA . A study of antibiogram revealed that all the MRSA were uniformly resistant to penicillin, erythromycin, gentamicin, tobramycin and tetracycline and sensitive to vancomycin . All isolates belonged to the same biotype and were nontypable by the standard set of phages.

J Laryngol Otol, 2000 Oct, 114(10), 796 - 7
Mycotic pseudoaneurysm of common carotid artery mimicking parapharyngeal abscess; Constantinides H et al.; In this case a secondarily infected pseudoaneurysm of the common carotid artery presented with clinical features suggestive of a parapharyngeal abscess . The causative organism was identified as community-acquired methicillin-resistant Staphylococcus aureus . To the authors' knowledge this condition not previously been reported.

Eur J Dermatol, 2000 Dec, 10(8), 630 - 2
Staphylococcal scalded skin syndrome with prosthetic valve endocarditis; Ansai SI et al.; We report staphylococcal scalded skin syndrome (SSSS) in a 67-year-old man . He showed diffuse erythema with erosion on his face and erythema with giant desquamation on his neck, axilla, genitalia, chest and abdomen 39 days after a coronary artery bypass graft and aortic valve replacement . He died of cardiac rupture caused by myocardial necrosis, and autopsy findings demonstrated prosthetic valve endocarditis due to a strain of exfoliative toxin-B producing methicillin-resistant Staphylococcus aureus . To the best of our knowledge, this is the first case of SSSS caused by prosthetic valve endocarditis.

Arch Dis Child Fetal Neonatal Ed, 2001 Jan, 84(1), F38 - 9
Acquired subglottic stenosis caused by methicillin resistant Staphylococcus aureus that produce epidermal cell differentiation inhibitor; Yamada Y et al.; Local infection of the trachea in intubated neonates is one of the main risk factors for development of acquired subglottic stenosis, although its role in the pathogenesis is unclear . Methicillin resistant Staphylococcus aureus (MRSA) is often the cause of critical illness in neonatal patients . Two cases are reported of acquired subglottic stenosis following bacterial infection of the trachea, suggesting an association with the staphylococcal exotoxin, epidermal cell differentiation inhibitor (EDIN) . EDIN-producing MRSA were isolated from purulent tracheal secretions from both infants . Acquired subglottic stenosis in both cases was probably caused by delayed wound healing as the result of EDIN inhibition of epithelial cell migration.

J Immunol, 2001 Jan 1, 166(1), 669 - 77
egc, a highly prevalent operon of enterotoxin gene, forms a putative nursery of superantigens in Staphylococcus aureus; Jarraud S et al.; The recently described staphylococcal enterotoxins (SE) G and I were originally identified in two separate strains of Staphylococcus aureus . We have previously shown that the corresponding genes seg and sei are present in S . aureus in tandem orientation, on a 3.2-kb DNA fragment (Jarraud, J . et al . 1999 . J . Clin . Microbiol . 37:2446-2449) . Sequence analysis of seg-sei intergenic DNA and flanking regions revealed three enterotoxin-like open reading frames related to seg and sei, designated sek, sel, and sem, and two pseudogenes, psi ent1 and psi ent2 . RT-PCR analysis showed that all these genes, including seg and sei, belong to an operon, designated the enterotoxin gene cluster (egc) . Recombinant SEG, SEI, SEK, SEL, and SEM showed superantigen activity, each with a specific V beta pattern . Distribution studies of genes encoding superantigens in clinical S . aureus isolates showed that most strains harbored such genes and in particular the enterotoxin gene cluster, whatever the disease they caused . Phylogenetic analysis of enterotoxin genes indicated that they all potentially derived from this cluster, identifying egc as a putative nursery of enterotoxin genes.

Antimicrob Agents Chemother, 2001 Jan, 45(1), 349 - 52
Clinical isolate of vancomycin-heterointermediate Staphylococcus aureus susceptible to methicillin and in vitro selection of a vancomycin-resistant derivative; Bobin-Dubreux S et al.; A Staphylococcus aureus strain with low-level heteroresistance to vancomycin (designated MER) but susceptible to methicillin was isolated from an outpatient with conjunctivitis who did not receive any glycopeptide antibiotics . Incubation of the parent strain, MER, with increasing concentrations of vancomycin led to rapid selection of a stable progeny homogeneously resistant to vancomycin . Electron micrographs of strain MER showed enhanced cell wall thickness and abnormal septations typically seen with methicillin-resistant S . aureus having intermediate susceptibility to vancomycin.

Antimicrob Agents Chemother, 2001 Jan, 45(1), 280 - 7
A spectrum of changes occurs in peptidoglycan composition of glycopeptide-intermediate clinical Staphylococcus aureus isolates; Boyle-Vavra S et al.; The mechanism of glycopeptide resistance in Staphylococcus aureus is not known with certainty . Because the target of vancomycin is the D-Ala-D-Ala terminus of the stem peptide of the peptidoglycan precursor, by subjecting muropeptides to reversed-phase high-performance liquid chromatography, we investigated peptidoglycan obtained from glycopeptide-intermediate S . aureus (GISA) isolates for changes in composition and evaluated whether any peptidoglycan structural change was a consistent feature of clinical GISA isolates . GISA isolates Mu50 and Mu3 from Japan had the large glutamate-containing monomeric peak demonstrated previously, although strain H1, a vancomycin-susceptible MRSA isolate from Japan that was clonally related to Mu3 and Mu50, and a femC mutant that we studied, did also . For the U.S . GISA isolates, strain NJ had a large monomeric peak with a retention time identical to that described for the glutamate-containing monomer in strains H1, Mu3, and Mu50 . However, a much smaller corresponding peak was seen in GISA MI, and this peak was absent from both GISA PC and a recent GISA isolate obtained from an adult patient in Illinois (strain IL) . These data suggest that a uniform alteration in peptidoglycan composition cannot be discerned among the GISA isolates and indicate that a single genetic or biochemical change is unlikely to account for the glycopeptide resistance phenotype in the clinical GISA isolates observed to date . Furthermore, a large monomeric glutamate-containing peak is not sufficient to confer the resistance phenotype.

Antimicrob Agents Chemother, 2001 Jan, 45(1), 208 - 11
In vivo activity of evernimicin (SCH 27899) against methicillin-resistant Staphylococcus aureus in experimental infective endocarditis; Boucher HW et al.; Currently, there exist few satisfactory alternatives to vancomycin for therapy of serious methicillin-resistant Staphylococcus aureus (MRSA) infections . We employed a rat model of aortic valve endocarditis to assess the potential efficacy of evernimicin (SCH 27899) compared with vancomycin against infection with a strain susceptible to both agents (MICs of 0.25 and 0.50 microg/ml, respectively) . Infected animals were assigned to one of three groups: controls (no treatment), evernimicin at 60 mg/kg of body weight by intravenous (i.v.) infusion once daily, or vancomycin at 150 mg/kg of body weight per day by continuous i.v . infusion . Therapy was administered for 5.5 days . At the start of therapy, colony counts in vegetations were 6.63 +/- 0.44 log(10) CFU/g . In both treatment groups, bacterial density within vegetations was significantly reduced in comparison with control animals that had not been treated . Final colony counts were as follows (mean +/- standard deviation): controls, 10.12 +/- 1.51 log(10) CFU/g of vegetation; evernimicin, 7.22 +/- 2.91 log(10) CFU/g of vegetation; vancomycin, 5.65 +/- 1.76 log(10) CFU/g of vegetation . The difference between the evernimicin and vancomycin groups was not significant . These results confirmed the bacteriostatic activity of evernimicin in vivo in an experimental model of severe MRSA infection.

Antimicrob Agents Chemother, 2001 Jan, 45(1), 196 - 202
Effects of amoxicillin, gentamicin, and moxifloxacin on the hemolytic activity of Staphylococcus aureus in vitro and in vivo; Worlitzsch D et al.; In Staphylococcus aureus infection hemolysis caused by the extracellular protein alpha-toxin encoded by hla is thought to contribute significantly to its multifactorial virulence . In vitro, subinhibitory concentrations of beta-lactam antibiotics and fluoroquinolones increase the levels of hla and alpha-toxin expression, whereas aminoglycosides decrease the levels of hla and alpha-toxin expression . In the present study we investigated the effects of subinhibitory concentrations of amoxicillin, gentamicin, and moxifloxacin on hla and alpha-toxin expression and total hemolysis of S . aureus strain 8325-4, a high-level alpha-toxin producer, and its alpha-toxin-negative mutant, DU 1090, in vitro and in a rat model of chronic S . aureus infection . The levels of expression of hla and alpha-toxin and total hemolysis did not differ significantly when amoxicillin, gentamicin, or moxifloxacin was added to cultures of S . aureus strain 8325-4 . In vivo, strain 8325-4 induced a significantly increased level of hemolysis in infected pouches compared to that in uninfected control pouches, but the hemolysis was reduced to control levels by treatment with doses of amoxicillin, gentamicin, or moxifloxacin that reduced bacterial numbers by 2 orders of magnitude . Additionally, the effects of subinhibitory concentrations of the three antibiotics on total hemolysis of four methicillin-resistant S . aureus and three methicillin-sensitive S . aureus (MSSA) clinical isolates were assessed in vitro . A significant increase in total hemolysis was observed for only one MSSA strain when it was treated with amoxicillin but not when it was treated with moxifloxacin or gentamicin . When purified alpha-toxin was incubated with purified human neutrophil elastase, alpha-toxin was cleaved nearly completely . The results suggest that the penicillin-induced increases in S . aureus alpha-toxin expression are strain dependent, that reduction of bacterial numbers in vivo counteracts this phenomenon effectively, and finally, that in localized S . aureus infections alpha-toxin activity is controlled by neutrophil elastase.

Antimicrob Agents Chemother, 2001 Jan, 45(1), 79 - 83
Effects of mutations in ribosomal protein L16 on susceptibility and accumulation of evernimicin; McNicholas PM et al.; Chemical mutagenesis of Staphylococcus aureus RN450 generated two strains that displayed a stable reduction (30- to 60-fold) in susceptibility to evernimicin . Cell-free translation reactions demonstrated that the resistance determinant was located in the ribosomal fraction . Compared to ribosomes isolated from a wild-type strain, ribosomes from the mutant strains displayed an 8- to 10-fold reduction in affinity for {(14)C}evernimicin . In contrast, the mutants displayed no alteration in either binding affinity or in vitro susceptibility to erythromycin . Exponential cultures of the mutant strains accumulated significantly less {(14)C}evernimicin than the wild-type strain, suggesting that accumulation is dependent on the high affinity that evernimicin displays for its binding site . Sequencing rplP (encodes ribosomal protein L16) in the mutant strains revealed a single base change in each strain, which resulted in a substitution of either cysteine or histidine for arginine at residue 51 . Introduction of a multicopy plasmid carrying wild-type rplP into the mutant strains restored sensitivity to evernimicin, confirming that the alterations in rplP were responsible for the change in susceptibility . Overexpression of the mutant alleles in S . aureus RN450 had no effect on susceptibility to evernimicin, demonstrating that susceptibility is dominant over resistance.

J Immunol, 2000 Dec 15, 165(12), 6880 - 8
Expression and function of IL-12 and IL-18 receptors on human tonsillar B cells; Airoldi I et al.; IL-12 activates murine and human B cells, but little information is available as to the expression and function of IL-12R on human B lymphocytes . Here we show that the latter cells, freshly isolated from human tonsils, expressed the transcripts of both beta1 and beta2 chains of IL-12R and that beta2 chain mRNA was selectively increased (4- to 5-fold) by incubation with Staphylococcus aureus Cowan I bacteria or IL-12 . B cell stimulation with IL-12 induced de novo expression of the transcripts of the two chains of IL-18R, i.e., IL-1 receptor-related protein and accessory protein-like . Functional studies showed that both IL-12 and IL-18 signaled to B cells through the NF-kappaB pathway . In the case of IL-12, no involvement of STAT transcription factors, and in particular of STAT-4, was detected . c-rel and p50 were identified as the members of NF-kappaB family involved in IL-12-mediated signal transduction to B cells . IL-12 and IL-18 synergized in the induction of IFN-gamma production by tonsillar B cells, but not in the stimulation of B cell differentiation, although either cytokine promoted IgM secretion in culture supernatants . Finally, naive but not germinal center or memory, tonsillar B cells were identified as the exclusive IL-12 targets in terms of induction of NF-kappaB activation and of IFN-gamma production.

Infect Immun, 2001 Jan, 69(1), 360 - 6
Biochemical and biological properties of Staphylococcal enterotoxin K; Orwin PM et al.; Staphylococcus aureus is an important human pathogen which is implicated in a wide variety of diseases . Major determinants of the virulence of this organism include extracellular virulence factors . Staphylococcal enterotoxins (SEs) are important causative agents in staphylococcal toxic shock syndrome and food poisoning . Our study identified a novel enterotoxin, SEK, and examined its biochemical and biological properties . SEK had a molecular weight of 26,000 and an experimentally determined pI of between 7.0 and 7.5 . SEK was secreted by clinical isolates of S . aureus . We demonstrated that SEK had many of the biological activities associated with the SEs, including superantigenicity, pyrogenicity, the ability to enhance the lethal effect of endotoxin, and lethality in a rabbit model when administered by subcutaneous miniosmotic pump . Recombinant SEK was shown to stimulate human CD4(+) and CD8(+) T cells in a Vbeta-specific manner; T-cells bearing Vbeta 5.1, 5.2, and 6.7 were significantly stimulated to proliferate.

Infect Immun, 2001 Jan, 69(1), 345 - 52
Clonal associations among Staphylococcus aureus isolates from various sites of infection; Booth MC et al.; A molecular epidemiological analysis was undertaken to identify lineages of Staphylococcus aureus that may be disproportionately associated with infection . Pulsed-field gel electrophoresis analysis of 405 S . aureus clinical isolates collected from various infection types and geographic locations was performed . Five distinct S . aureus lineages (SALs 1, 2, 4, 5, and 6) were identified, which accounted for 19.01, 9.14, 22.72, 10.12, and 4.69% of isolates, respectively . In addition, 85 lineages which occurred with frequencies of <2.5% were identified and were termed "sporadic." The most prevalent lineage was methicillin-resistant S . aureus (SAL 4) . The second most prevalent lineage, SAL 1, was also isolated at a high frequency from the anterior nares of healthy volunteers, suggesting that its prevalence among clinical isolates may be a consequence of high carriage rates in humans . Gene-specific PCR was carried out to detect genes for a number of staphylococcal virulence traits . tst and cna were found to be significantly associated with prevalent lineages compared to sporadic lineages . When specific infection sites were examined, SAL 4 was significantly associated with respiratory tract infection, while SAL 2 was enriched among blood isolates . SAL 1 and SAL 5 were clonally related to SALs shown by others to be widespread in the clinical isolate population . We conclude from this study that at least five phylogenetic lineages of S . aureus are highly prevalent and widely distributed among clinical isolates . The traits that confer on these lineages a propensity to infect may suggest novel approaches to antistaphylococcal therapy.

Infect Immun, 2001 Jan, 69(1), 159 - 69
Description of staphylococcus serine protease (ssp) operon in Staphylococcus aureus and nonpolar inactivation of sspA-encoded serine protease; Rice K et al.; Signature tagged mutagenesis has recently revealed that the Ssp serine protease (V8 protease) contributes to in vivo growth and survival of Staphylococcus aureus in different infection models, and our previous work indicated that Ssp could play a role in controlling microbial adhesion . In this study, we describe an operon structure within the ssp locus of S . aureus RN6390 . The ssp gene encoding V8 protease is designated as sspA, and is followed by sspB, which encodes a 40.6-kDa cysteine protease, and sspC, which encodes a 12.9-kDa protein of unknown function . S . aureus SP6391 is an isogenic derivative of RN6390, in which specific loss of SspA function was achieved through a nonpolar allelic replacement mutation . In addition to losing SspA, the culture supernatant of SP6391 showed a loss of 22- to 23-kDa proteins and the appearance of a 40-kDa protein corresponding to SspB . Although the 40-kDa SspB protein could degrade denatured collagen, our data establish that this is a precursor form which is normally processed by SspA to form a mature cysteine protease . Culture supernatant of SP6391 also showed a new 42-kDa glucosaminidase and enhanced glucosaminidase activity in the 29 to 32 kDa range . Although nonpolar inactivation of sspA exerted a pleiotropic effect, S . aureus SP6391 exhibited enhanced virulence in a tissue abscess infection model relative to RN6390 . Therefore, we conclude that SspA is required for maturation of SspB and plays a role in controlling autolytic activity but does not by itself exert a significant contribution to the development of tissue abscess infections.

Infect Immun, 2001 Jan, 69(1), 45 - 51
Staphylococcus aureus agr genotypes with enterotoxin production capabilities can resist neutrophil bactericidal activity; Mullarky IK et al.; Staphylococcus aureus pathogenicity is mainly due to the production of a number of secreted and cell surface-associated proteins under the regulation of the agr gene . A region of the agr gene was used to subgroup S . aureus strains according to restriction fragment length polymorphisms . Additionally, strains were subtyped according to the coagulase gene in order to strengthen discriminatory power . Virulence capabilities of agr genotype subgroups were evaluated using an in vitro neutrophil bactericidal assay, which showed that prevalent genotypes were significantly better at evading this primary host defense . Multiplex PCR was then used to detect enterotoxin genes among the genotype subgroups in order to determine possible virulence candidates that enable strains to combat neutrophil killing . The prevalent genotype strains were found to possess higher production capabilities for enterotoxin A than did low-prevalence strains . The significance of enterotoxin A production capabilities in affecting pathogenicity of S . aureus strains was evaluated and found to have a profound effect on neutrophil killing abilities . The use of a large epidemiological database as a tool for subgrouping strains with varying degrees of pathogenicity has allowed the identification of relevant and previously undefined virulence factors that affect a pathogen's capability to overcome host immune defenses.

FEMS Immunol Med Microbiol, 2000 Dec, 29(4), 315 - 21
Identification of the secreted macromolecular immunogens of Staphylococcus aureus by analysis of serum; Royan S et al.; The ability of sera to recognise secreted macromolecules of Staphylococcus aureus was examined by ELISA and Western immunoblotting . Individual secreted proteins were also studied using both human sera and sera from rabbits immunised with secreted macromolecules . Patients sera showed a wide range of IgG antibody titres to secreted macromolecules and whole bacteria . Controls showed a significantly lower IgG response . Western immunoblotting revealed that a significant number of secreted proteins were recognised by circulating IgG antibodies . Surprisingly, both the sera from controls and from patients recognised similar macromolecules including a number of potential virulence factors . The major difference was in the IgG binding to a 16-kDa component, which was recognised by the majority of the sera from infected individuals, but only by a small number of sera from healthy controls . The higher incidence of antibodies recognising the 16 kDa component may be related to our earlier finding that the major bone resorbing component of S . aureus is a heterodimeric protein containing a 16-kDa subunit, the activity of which could be blocked by sera.

Vet Microbiol, 2001 Jan 5, 78(1), 39 - 48
Genetic analysis of exfoliative toxin A-producing Staphylococcus aureus isolated from mastitic cow's milk; Hayakawa Y et al.; Exfoliative toxin A (ETA), produced by Staphylococcus aureus, is the causative agent of staphylococcal scalded-skin syndrome (SSSS) in children . Recently, we reported that ETA was detected by reverse passive latex agglutination in three isolates of S . aureus from cow's milk, but that these ETA-positive isolates did not cause the so-called Nikolsky sign in neonatal mice . In this study, therefore, the eta gene encoding ETA and regulatory genes of these bovine isolates were analyzed by the polymerase chain reaction (PCR) and sequencing . The eta gene was amplified from three bovine isolates by PCR and their resulting nucleotide sequences found to correspond to the eta gene from the human isolate, except for three nucleotides in the upstream region of the eta open reading frame (ORF) . An accessory gene regulator (agr), which is a global regulatory locus, was detected in these bovine isolates by PCR amplification . In addition, the ORF (J-4), located 120 bp upstream from the eta ORF of the human isolate, was also amplified from these bovine isolates, with their nucleotide sequences differing at 32 positions from the human isolate . Bovine and human ORF J-4 equally enhanced production of ETA in the recombinants of the eta gene, suggesting that the variation in bovine ORF J-4 may be not be the cause of the difference in amount of ETA produced by bovine and human isolates.

Clin Infect Dis, 2001 Jan, 32(1), 108 - 15 Epub 2000 Dec 13.
Vancomycin-intermediate and -resistant Staphylococcus aureus: what the infectious disease specialist needs to know; Fridkin SK; Ever since the first strain of Staphylococcus aureus with reduced susceptibility to vancomycin and teicoplanin was reported from Japan, there has been a lot of confusion regarding the laboratory and clinical approach to patients with infections due to S . aureus with reduced susceptibility to vancomycin . To date, 6 clinical infections with vancomycin-intermediate S . aureus (VISA) have been reported in the United States . Intermediate resistance appears to develop from preexisting strains of methicillin-resistant S . aureus in the presence of vancomycin, and all but 1 infection occurred in patients with exposure to dialysis for renal insufficiency . Detection of VISA is difficult in the laboratory, and special inquiries about susceptibility testing methods may be needed . These VISA-infected patients had underlying illnesses, and their infections did not appear to respond well to conventional treatment . Prevention strategies have been outlined . Without continued vigilance in enforcing infection-control measures, improved use of antimicrobials, and coordination of efforts among public health authorities, increasing levels of vancomycin resistance in S . aureus are likely to be encountered.

J Nippon Med Sch, 2000 Dec, 67(6), 464 - 7
Septic arthritis of the hip associated with atopic dermatitis . A case report; Kitamura S et al.; We report a case of septic arthritis of the hip associated with atopic dermatitis . A 15-year female felt a pain in the right hip with unknown cause on May 11, 1998 . The pain subsequently became aggravated, and she was admitted to our hospital on May 18 . She has had atopic dermatitis since 4 years of age . She showed generalized dermatitis with desquamation and numerous scratch marks . A culture of both skin and joint fluid revealed Staphylococcus aureus . Physical examination revealed tenderness in Scarpa triangle and restricted range of motion . Immunological serology showed an increase in eosinophils and immunoglobulin E, and a decreased reaction of lymphocyte blastoid transformation . Computed tomography (CT) and MRI showed a joint effusion in the right hip . She was diagnosed as having septic arthritis of the hip . Intravenous drip of Cefazolin of 2g was started on the first day of hospitalization and joint irrigation was done on the second day . CRP became negative at 4 weeks, but joint effusion was shown on CT . Additional joint irrigation with Amicamycin (200 mg) was done . As the joint fluid culture became negative, range of motion exercises were started at 6 weeks . She was discharged with a long-leg brace applied at 8 weeks . At 13 months after onset, she had complete relief of the pain and normal activities of daily living . No destructive changes in the hip were found on X-ray examination or MRI . In the present case, an abnormal immune system associated with atopic dermatitis as well as the habit of scratching eruptions may have led to hematogenous spread of skin infection, and caused septic arthritis of the hip.

Chest, 2000 Dec, 118(6), 1832 - 3
Staphylococcus aureus pericarditis masquerading as anterior mediastinal mass: mediastinal mass from pericarditis; Nwiloh JO et al.; Pseudomediastinal mass as a result of bacterial pericarditis is a rare clinical presentation . We report one such case in a patient with end-stage renal disease receiving hemodialysis, who presented primarily with manifestations of right heart compression due to a large encapsulated pericardial abscess and, surprisingly, with no overt signs of sepsis . Surgical drainage, pericardiectomy, and antibiotic therapy led to a successful outcome.

Arch Otolaryngol Head Neck Surg, 2000 Dec, 126(12), 1440 - 3
Methicillin-resistant Staphylococcus aureus otorrhea after tympanostomy tube placement: an emerging concern; Hartnick CJ et al.; OBJECTIVES: To review the treatment of pediatric patients with methicillin-resistant Staphylococcus aureus (MRSA)-positive cultures as a result of otorrhea after tympanostomy tube placement in terms of both medication and isolation strategies and to highlight an emerging problem faced by the clinician with reference to treatment options as well as to the treatment of these patients in an outpatient setting . PATIENTS: Between December 1998 and January 2000, a total of 8 children between the ages of 1 and 11 years had MRSA-positive cultures as a result of otorrhea after tympanostomy tube placement . MAIN OUTCOME MEASURES: The Department of Infectious Diseases was notified, and a variety of topical antibiotic treatments were administered . Arch Otolaryngol Head Neck Surg . 2000;126:1440-1443

Mol Microbiol, 2000 Nov, 38(4), 694 - 705
Phage conversion of exfoliative toxin A production in Staphylococcus aureus; Yamaguchi T et al.; The staphylococcal exfoliative toxins (ETs) are extracellular proteins that cause splitting of human skin at the epidermal layer during infection in infants . Two antigenically distinct toxins possessing identical activity have been isolated from Staphylococcus aureus, ETA and ETB . The gene for ETA (eta) is located on the chromosome, whereas that for ETB is located on a large plasmid . The observation that relatively few clinical isolates produce ETA suggests that the eta gene is acquired by horizontal gene transfer . In this study, we isolated a temperate phage (phiETA) that encodes ETA and determined the complete nucleotide sequence of the phiETA genome . phiETA has a head with a hexagonal outline and a non-contractile and flexible tail . The genome of phiETA is a circularly permuted linear double-stranded DNA, and the genome size is 43 081 bp . Sixty-six open reading frames (ORFs) were identified on the phiETA genome, including eta, which was found to be located very close to a putative attachment site (attP) . phiETA converted ETA non-producing strains into ETA producers . Southern blot analysis of chromosomal DNA from clinical isolates suggested that phiETA or related phages are responsible for the acquisition of eta genes in S . aureus.

J Bacteriol, 2001 Jan, 183(1), 63 - 70
Characterization of a putative pathogenicity island from bovine Staphylococcus aureus encoding multiple superantigens; Fitzgerald JR et al.; Previous studies have demonstrated that a proportion of Staphylococcus aureus isolates from bovine mastitis coproduce toxic shock syndrome toxin (TSST) and staphylococcal enterotoxin C (SEC) . In this study, molecular genetic analysis of one such strain, RF122, revealed the presence of a 15,891-bp putative pathogenicity island (SaPIbov) encoding the genes for TSST (tst), the SEC bovine variant (sec-bovine), and a gene (sel) which encodes an enterotoxin-like protein . The island contains 21 open reading frames specifying hypothetical proteins longer than 60 amino acids including an integrase-like gene . The element is bordered by 74-bp direct repeats at the left and right junctions, and the integration site lies adjacent to the 3' end of the GMP synthase gene (gmps) in the S . aureus chromosome . SaPIbov contains a central region of sequence identity with the previously characterized tst pathogenicity island SaPI1 (J . A . Lindsay et al., Mol . Microbiol . 29:527-543, 1998) . A closely related strain, RF120, of the same multilocus enzyme electrophoretic type, random amplified polymorphic DNA type, and ribotype, does not contain the island, implying that the element is mobile and that a recent insertion/deletion event has taken place . TSST and TSST/SEC-deficient mutants of S . aureus strain RF122 were constructed by allele replacement . In vitro bovine Vbeta-specific lymphocyte expansion analysis by culture supernatants of wild-type strains and of tst and sec-bovine allele replacement mutants revealed that TSST stimulates BTB13-specific T cells whereas SEC-bovine stimulates BTB93-specific T cells . This suggests that the presence of SaPIbov may contribute to modulation of the bovine immune response.

Biochemistry, 2000 Dec 19, 39(50), 15344 - 52
Rhodamine 123 binds to multiple sites in the multidrug resistance protein (MRP1); Daoud R et al.; The mechanisms of MRP1-drug binding and transport are not clear . In this study, we have characterized the interaction between MRP1 and rhodamine 123 (Rh123) using the photoreactive-iodinated analogue, {(125)I}iodoaryl azido-rhodamine 123 (or IAARh123) . Photoaffinity labeling of plasma membranes from HeLa cells transfected with MRP1 cDNA (HeLa-MRP1) with IAARh123 shows the photolabeling of a 190 kDa polypeptide not labeled in HeLa cells transfected with the vector alone . Immunoprecipitation of a 190 kDa photolabeled protein with MRP1-sepcific monoclonal antibodies (QCRL-1, MRPr1, and MRPm6) confirmed the identity of this protein as MRP1 . Analysis of MRP1-IAARh123 interactions showed that photolabeling of membranes from HeLa-MRP1 with increasing concentrations of IAARh123 was saturable, and was inhibited with excess of IAARh123 . Furthermore, the photoaffinity labeling of MRP1 with IAARh123 was greatly reduced in the presence of excess Leukotreine C(4) or MK571, but to a lesser extent with excess doxorubicin, colchicine or chloroquine . Cell growth assays showed 5-fold and 14-fold increase in the IC(50) of HeLa-MRP1 to Rh123 and the Etoposide VP16 relative to HeLa cells, respectively . Analysis of Rh123 fluorescence in HeLa and HeLa-MRP1 cells with or without ATP suggests that cross-resistance to Rh123 is in part due to reduced drug accumulation in the cytosol of HeLa-MRP1 cells . Mild digestion of purified IAARh123-photolabeled MRP1 with trypsin showed two large polypeptides (approximately 111 and approximately 85 kDa) resulting from cleavage in the linker domain (L1) connecting the multiple-spanning domains MSD0 and MSD1 to MSD2 . Exhaustive proteolysis of purified IAARh123-labeled 85 and 111 kDa polypeptides revealed one (6 kDa) and two (approximately 6 plus 4 kDa) photolabeled peptides, respectively . Resolution of total tryptic digest of IAARh123-labeled MRP1 by HPLC showed three radiolabeled peaks consistent with the three Staphylococcus aureus V8 cleaved peptides from the Cleveland maps . Together, the results of this study show direct binding of IAARh123 to three sites that localize to the N- and C-domains of MRP1 . Moreover, IAARh123 provides a sensitive and specific probe to study MRP1-drug interactions.

Eur J Drug Metab Pharmacokinet, 2000 Apr-Jun, 25(2), 103 - 8
In vivo metabolism of 4-fluorobenzoic acid {(5-nitro-2-furanyl)methylene} hydrazide in rats; Gulerman NN et al.; It is known that substituted hydrazide hydrazone derivatives have several biological and pharmacological activities; there is limited literature on the metabolism of hydrazide hydrazones in rats . In our previous study, 4-fluorobenzoic acid {(5-nitro-2-furanyl)methylene}hydrazide (S) was found active against Staphylococcus aureus ATCC 29213 . Therefore, we planned to study the in vivo metabolism of S in rats . The substrate was administered in doses of 50 mg/kg or 100 mg/kg intraperitoneally . Blood samples were collected at 0, 5, 15, 30, 45 min and 1, 1.5, 2, 4, 8, 12, 24, 48 h after administration . The substrate and its potential metabolites were separated using HPLC on a reverse phase system . 4-Fluorobenzoic acid and one unidentified metabolite were detected together with substrate.

Vet Hum Toxicol, 2000 Dec, 42(6), 341 - 4
Evaluation of the antibacterial and hemolytic activities of Latvian herbal preparation; Atroshi F et al.; Three extracts originating from a combination of various Latvian plant species were tested for their antibacterial activities by evaluating growth delays using a fully automated microturbidimetric method . Ten different human and bovine strains of the genera Staphylococcus and Micrococcus were used as test microorganisms . The inhibitory effect in vitro was defined as the difference between the growth rate without herbs and the growth rate in the presence of an extract . Among the tested strains, Staphylococcus aureus was found sensitive to all 3 extracts . However, extract I was the most effective in slowing the growth of all strains tested . Using appropriate tester strains it should be possible to set up a broad-range microtubidimetry assay for individual herb screening in vitro . The hemolytic effects of the individual extracts on human erythrocytes were also studied at different concentrations . Two of the herbal extracts had minimal lytic effects on eurocaryotic cells . An additional hemolysis test was conducted in the presence of coenzyme Q10 (CoQ10) as a free radical scavenger: CoQ10 had no effect on the hemolytic reaction.

ASAIO J, 2000 Nov-Dec, 46(6), S13 - 7
Staphylococcus aureus infections in dialysis patients: focus on prevention; Piraino B; Staphylococcus aureus infections are a major cause of morbidity and hospitalization in dialysis patients . The risk of infection relates to the type of access . Patients with acute hemodialysis (HD) catheters are at the greatest risk of S . aureus bacteremia, followed by tunneled HD catheters, and grafts . Patients with a fistula have a rate similar to that of peritoneal (PD) patients . In PD patients, however, S . aureus is the second most common cause of peritonitis, is often associated with a catheter infection, and frequently requires catheter removal for resolution . S . aureus infections in dialysis patients are much more common in nasal carriers . S . aureus moves from the nasal reservoir to the hands and skin, and from there to infect the access . Therefore, prevention of infection can be aimed at treating the carriage or in applying antibiotics at the catheter exit site, thus preventing colonization and subsequent infection of the catheter . For HD patients with a permanent access (either fistula or graft), intranasal mupirocin, twice a day for 5 days followed by a once weekly application, is effective in reducing the risk of S . aureus bacteremia . Cost analysis indicates that treating all patients would result in more cost savings than treating just carriers . For patients with acute HD catheters, exit site mupirocin applied as part of routine care during each HD treatment, reduces the risk of S . aureus exit site infection and bacteremia . For PD patients, S . aureus infections can be diminished by using mupirocin at the exit site as part of daily exit site care . Prophylaxis against S . aureus is under utilized in dialysis patients and, if implemented, could lower the rate of these serious infections.

ASAIO J, 2000 Nov-Dec, 46(6), S6 - 12
Dialysis access related infections; Lew SQ et al.; Infection is a common cause of morbidity and mortality in end-stage renal disease patients . Unintentional pathogens are introduced into an immunocompromised host during hemodialysis and peritoneal dialysis by means of the access (arteriovenous fistula, arteriovenous graft, central venous catheter, or peritoneal dialysis catheter) . Gram positive organisms are most common with Staphylococcus aureus and coagulase negative Staphylococcus predominating . Preventive measures are mandatory and the key to decreasing infection rates.

APMIS, 2000 Sep, 108(9), 565 - 72
Characterisation of isolates of Staphylococcus aureus from acute, chronic and subclinical mastitis in cows in Norway; Tollersrud T et al.; Eighty-six Staphylococcus aureus isolates from cases of bovine mastitis were characterised biochemically and with respect to serotype, multilocus enzyme electrophoresis genotypes, antibiotic sensitivity, and production of enterotoxins A through D (SEA-D) and toxic shock syndrome toxin-1 (TSST-1) . The samples were obtained from 81 different cows from 79 Norwegian dairy herds in 10 different counties in southern Norway . There was an equal representation of isolates from cases of acute, chronic and subclinical mastitis . Multilocus enzyme electrophoresis using 13 genetic loci showed that 69 of 86 isolates had the same electrophoretic type . This common electrophoretic type comprised isolates that differed in the expression of other phenotypical characteristics studied . Fifty-eight percent of the isolates produced one or more enterotoxins, predominantly a combination of SEC and TSST-1 . Capsular serotyping revealed that 95% of the isolates belonged to serotype 8 . No correlation was found between the factors studied and the clinical classification of mastitis . It appears that the majority of S . aureus isolates recovered from cases of bovine mastitis in Norway are genetically closely related and express common phenotypical characteristics.

Can J Microbiol, 2000 Nov, 46(11), 1066 - 76
Genomic relatedness of Staphylococcus aureus phages of the International Typing Set and detection of serogroup A, B, and F prophages in lysogenic strains; Doskar J et al.; On the basis of HindIII-restriction digest analysis of genomic DNAs, the S . aureus bacteriophages of the International Typing Set were divided into five clusters designated as A, F, Ba, Bb, and Bc . The clusters A and F include all the phages of serogroups A and F and correspond to species 3A and 77 proposed by Ackermann and DuBow (1987) . On the other hand, the phages of serogroup B were divided into three clusters designated as Ba, Bb, and Bc that differ significantly each from the other in their restriction patterns . The clusters Ba and Bb may represent two separate species, while the cluster Bc may include more than one phage species . For each of the phage serogroups A, B, and F, common HindIII-restriction fragments of phage 3A (1700 bp), of 53 (4060 bp), and of 77 (8300 bp) were used for the preparation of probes specific to the phages of serogroups A, B, and F . These probes were very effective, making it possible to detect up to three different prophages in a given lysogenic strain at the same time . Restriction enzyme maps of phages 3A, 53, and 77, each representing a different serogroup, were constructed . The restriction maps of phage 3A and that of phage 77 are linear, whereas that of phage 53 is circular and exhibits a circular permutation . DNAs of the phages of serogroups A and F have cohesive ends . On each restriction map, the sites corresponding to specific probes are indicated . The size of intact genomic DNA of all phages estimated by PFGE varies within the range of 41.5-46.2 kb.

Cutis, 2000 Oct, 66(4), 296 - 300
The effect of antibacterial soap with 1.5% triclocarban on Staphylococcus aureus in patients with atopic dermatitis; Breneman DL et al.; This double-blind study determined whether daily bathing with an antibacterial soap would reduce the number of Staphylococcus aureus on the skin and result in clinical improvement of atopic dermatitis . For 9 weeks, 50 patients with moderately severe atopic dermatitis bathed daily with either an antimicrobial soap containing 1.5% triclocarban or the placebo soap . They also used a nonmedicated moisturizer and 0.025% triamcinolone acetonide cream as needed, but the availability of the corticosteroid cream was discontinued after 6 weeks . The antimicrobial soap regimen caused significantly greater improvement in the severity and extent of skin lesions than the placebo soap regimen, which correlated with reductions both in S aureus in patients with positive cultures at baseline and in total aerobic organisms . Outcome measures included reductions in S aureus, total aerobic organisms, and dermatologic assessments . Overall, daily bathing with an antibacterial soap was well tolerated, provided clinical improvement, and reduced levels of skin microorganisms.

Diagn Microbiol Infect Dis, 2000 Nov, 38(3), 159 - 67
In vivo development of decreased susceptibility to vancomycin in clinical isolates of methicillin-resistant Staphylococcus aureus; Sugino Y et al.; To investigate the possibility of in vivo development of decreased vancomycin susceptibility, the vancomycin susceptibilities of 12 methicillin-resistant Staphylococcus aureus (MRSA) isolates serially recovered from six patients with vancomycin therapy were tested by standard MIC determination method and population analysis . While all of the MRSA isolates were susceptible to vancomycin (MICs, 1-2 microg/ml) by standard method, population analysis showed the upward shifts indicating decreased vancomycin susceptibility among serial isolates from two patients . These bacteria with decreased vancomycin susceptibility could be selected by using vancomycin selection of pre-therapy isolates under laboratory conditions . Furthermore, the reversion phenomenon of decreased vancomycin susceptibility was confirmed after 20 serial passages of the post-therapy isolates on drug-free agar . These data suggest that in vivo isolates may develop decreased vancomycin susceptibility that is not of such magnitude to cross a breakpoint threshold . This resistance may be unstable, and appears to result from a selective or inducible process that occurs in MRSA clinical strains during vancomycin therapy.

Ugeskr Laeger, 2000 Nov 13, 162(46), 6241 - 3
{Incidence of methicillin-resistant Staphylococcus aureus among Kosovar-Albanian refugees at the refugee-center in Randers}; Hansen B et al.; INTRODUCTION: With the emergence of the war in Kosova, Europe faced a massive problem dealing with the refugees . The Danish quota was 3,000 refugees . Their health care was organised by the Danish Red Cross in collaboration with the District Hospital of Randers (DHR), the University Hospital of Arhus, and the Psychiatry Unit of the County of Arhus . The aim of the present retrospective study was to describe the prevalence of MRSA in this group of refugees . MATERIALS AND METHODS: Nasal screening culture for MRSA was performed on the first 50 refugees arriving at Randers . On admission to the DHR, the Kosovar-Albanian refugees were isolated until the MRSA culture showed negative . RESULTS: MRSA causing serious nosocomial infections has become a major problem in hospitals worldwide, with a higher incidence in the southern part of Europe than in Denmark . The initial nasal screening revealed no MRSA positive cultures . During the course of the subsequent 14 months, we found eight Kosovar-Albanian refugees infected with/colonised by MRSA (Table 1) . We observed no spread of MRSA to other patient groups . CONCLUSION: We conclude that 1) the results of the initial screening of 50 refugees did not predict the succeding high incidence of MRSA; 2) the usual treatment with mupirocin nasal ointment and chlorhexidine wash did not prevent either reinfection or spread of MRSA in the refugee centre; 3) the rigorous isolation and screening strategy at DHR prevented the spread of MRSA to other patients and staff.

Med Dosw Mikrobiol, 2000, 52(1), 1 - 7
{Nonspecific adhesion of Staphylococcus aureus strains to solid surfaces}; Dziedzina D et al.; Autoagregating strains of bacteria are characterised by high surface hydrophobicity, which determines their ability to adhesion . An assessment was done of non-specific adhesion to solid surfaces of S . aureus strains isolated from blood, pus and nasopharynx of hospitalised people . The method used made possible differentiation of strains, which were studied, on the basis of their surface characteristics . Their properties decide about the abilities of strains to the colonisation of host tissues and at the same time they influence their potential virulence . In the study attention was also paid to the participation of surface proteins in the processes of adhesion cells to glass surfaces.

Immunopharmacol Immunotoxicol, 2000 Nov, 22(4), 627 - 51
TNF-alpha blockade by a dimeric TNF type I receptor molecule selectively inhibits adaptive immune responses; Colagiovanni DB et al.; Tumor necrosis factor-alpha (TNF-alpha) is a mediator of severe inflammatory processes, including rheumatoid arthritis . Suppression of TNF with a soluble type I or type II receptor molecule (TNF-RI or TNF-RII) has the potential to decrease cytokine levels and modulate inflammatory diseases in humans . However, it has recently been reported that treatment of mice with a TNF-RI:Fc immunoadhesin protein augmented Gram positive infections and subsequent mortality . To determine if TNF-alpha blockade with soluble TNF-alpha receptors might alter immune system function, assays were assessed in rodents treated with a dimeric form of the p55 TNF-RI, Tumor Necrosis Factor-binding protein (TNFbp) . Administration of TNFbp resulted in suppression of primary and secondary IgG antibody responses and cell-mediated immune function . No treatment-related differences were detected in immune-enhancing assays or non-specific immune function parameters . Bacterial host resistance assays with Listeria monocytogenes, Staphylococcus aureus or Escherichia coli showed an increase in tissue colony counts only with L . monocytogenes challenged animals following TNFbp administration . These results suggest that TNFbp has the capacity to inhibit adaptive immune function in experimental animal models . Studies suggest that while reducing TNF-alpha is important in controlling cytokine-dependent disease states, maintenance of a threshold level may be critical for normal immune function.

Health Care Manag Sci, 2000 Sep, 3(4), 287 - 97
Diagnosis of MRSA with neural networks and logistic regression approach; Shang JS et al.; Antibiotic-resistant pathogens are increasingly prevalent in the hospitals and community . A timely and accurate diagnosis of the infection would greatly help physicians effectively treat patients . In this research we investigate the potential of using neural networks (NN) and logistic regression (LR) approach in diagnosing methicillin-resistant Staphylococcus aureus (MRSA) . Receiver-Operating Characteristic (ROC) curve and the cross-validation method are used to compare the performances of both systems . We found that NN is better than the logistic regression approach, in terms of both the discriminatory power and the robustness . With modeling flexibility inherent in its techniques, NN is effective in dealing with MRSA and other classification problems involving large numbers of variables and interaction complexity . On the other hand, logistic regression in our case is slightly inferior, offers more clarity and less perplexity . It could be a method of choice when fewer variables are involved and/or justification of the results is desired.

J Clin Invest, 2000 Dec, 106(11), 1409 - 15
Immunopathophysiological aspects of an emerging neonatal infectious disease induced by a bacterial superantigen; Takahashi N et al.; We recently discovered an emerging neonatal infectious disease, neonatal toxic shock syndrome-like (TSS-like) exanthematous disease (NTED), which is induced by a superantigen, TSS toxin-1 (TSST-1), produced by methicillin-resistant Staphylococcus aureus (MRSA) . Here, we analyzed the activation and the response of TSST-1-reactive Vss2(+) T cells in NTED patients during the acute and recovery phases and in asymptomatic infants exposed to MRSA . In the acute phase, Vss2(+) T cells were anergic to stimulation with TSST-1 and underwent marked expansion, but by 2 months after disease onset, their numbers had declined to about 10% of the control level . Although the percentage of Vss2(+) T cells in the ten asymptomatic neonatal MRSA carriers was within the control range, these individuals could be divided into two groups on the basis of Vss2(+) T-cell activation . Vss2(+)CD4(+) T cells from three of these infants (Group 1) highly expressed CD45RO and were anergic to TSST-1, whereas in the other seven asymptomatic neonatal MRSA carriers (Group 2), these cells expressed CD45RO at the control level and were highly responsive to stimulation with TSST-1 . The serum anti-TSST-1 IgG Ab titer was negligible in the four NTED patients in the acute phase and the three asymptomatic neonatal MRSA carriers in Group 1, but it was high in the seven asymptomatic carriers in Group 2 . We suggest that maternally derived anti-TSST-1 IgGs helps to suppress T-cell activation by TSST-1 and protects infants from developing NTED.

Biochem J, 2000 Dec 15, 352 Pt 3, 899 - 905
Use of alpha-toxin from Staphylococcus aureus to test for channelling of intermediates of glycolysis between glucokinase and aldolase in hepatocytes; Cascante M et al.; We investigated whether hepatocytes permeabilized with alpha-toxin from Staphylococcus aureus are a valid model for studying the channelling of intermediates of glycolysis between glucokinase and triosephosphate isomerase . These cells are permeable to 2-aminoisobutyrate, ATP, glucose 6-phosphate (Glc6P) and fructose 2, 6-bisphosphate {Fru(2,6)P(2)}, but maintain cell integrity in the presence of ATP as judged by the retention of cytoplasmic enzymes . During incubation with 25 mM glucose, an ATP-generating system and saturating concentrations of Fru(2,6)P(2), rates of detritiation of {2-(3)H}glucose and {3-(3)H}glucose were similar . Exogenous Glc6P (1 mM) and to a lesser extent fructose 6-phosphate, but not Fru(1, 6)P(2), decreased the rate of detritiation of {3-(3)H}glucose . During incubation with 25 mM glucose and Glc6P (0.2-1 mM), with either {3-(3)H}glucose or {3-(3)H}Glc6P as labelled substrate, there was dilution of metabolism of {3-(3)H}glucose with increasing Glc6P but no overall increase in glycolytic flux from glucose and Glc6P, indicating that glycolysis is apparently saturated with Glc6P despite the permeability of the cells to this metabolite . These findings could be explained by partial channelling of Glc6P between glucokinase and glycolysis in the presence of saturating concentrations of Fru(2,6)P(2) . They provide an alternative explanation for the concept that there is more than one Glc6P pool.

J Clin Microbiol, 2000 Dec, 38(12), 4351 - 5
Glyceraldehyde-3-phosphate dehydrogenase-encoding gene as a useful taxonomic tool for Staphylococcus spp; Yugueros J et al.; The gap gene of Staphylococcus aureus, encoding glyceraldehyde-3-phosphate dehydrogenase, was used as a target to amplify a 933-bp DNA fragment by PCR with a pair of primers 26 and 25 nucleotides in length . PCR products, detected by agarose gel electrophoresis, were also amplified from 12 Staphylococcus spp . analyzed previously . Hybridization with an internal 279-bp DNA fragment probe was positive in all PCR-positive samples . No PCR products were amplified when other gram-positive and gram-negative bacterial genera were analyzed using the same pair of primers . AluI digestion of PCR-generated products gave 12 different restriction fragment length polymorphism (RFLP) patterns, one for each species analyzed . However, we could detect two intraspecies RFLP patterns in Staphylococcus epidermidis, Staphylococcus hominis, and Staphylococcus simulans which were different from the other species . An identical RFLP pattern was observed for 112 S . aureus isolates from humans, cows, and sheep . The sensitivity of the PCR assays was very high, with a detection limit for S . aureus cells of 20 CFU when cells were suspended in saline . PCR amplification of the gap gene has the potential for rapid identification of at least 12 species belonging to the genus Staphylococcus, as it is highly specific.

Biotechnol Prog, 2000 Nov-Dec, 16(6), 1086 - 90
Shear stress affects the kinetics of Staphylococcus aureus adhesion to collagen; Li ZJ et al.; Staphylococcus aureus is a major human pathogen that has been shown to bind collagen under static conditions . However, many staphylococcal infections are hematogenously acquired and adhesion events may be influenced by shear stress . In this study, we used a dynamic experimental system consisting of a parallel-plate perfusion chamber and phase-contrast video microscope to study the effects of shear stress on the adhesion kinetics of intact S . aureus to collagen surfaces in vitro . The adhesion of S . aureus Phillips to collagen types I, II, and IV was investigated over a physiologically relevant range of wall shear stresses at 37 degrees C . S . aureus PH100, a collagen adhesin-deficient mutant strain, was used as a control strain for the experiments . We found that S . aureus Phillips could adhere to collagens I, II, and IV at wall shear stresses less than 15 dyn/cm(2) and that the kinetics of the adhesion process were wall shear stress-dependent . Similar studies with PH100 demonstrated that these cells are unable to adhere firmly to collagen surfaces . Transient interactions between PH100 and the collagen surfaces were observed at low levels of shear stress suggesting that S . aureus may also interact with collagen by an alternative mechanism that does not lead to firm adhesion.

J Biomol NMR, 2000 Oct, 18(2), 129 - 37
Sequence-specific NMR assignment of proteins by global fragment mapping with the program MAPPER; Guntert P et al.; A new program, MAPPER, for semiautomatic sequence-specific NMR assignment in proteins is introduced . The program uses an input of short fragments of sequentially neighboring residues, which have been assembled based on sequential NMR connectivities and for which either the 13C(alpha) and 13C(beta) chemical shifts or data on the amino acid type from other sources are known . MAPPER then performs an exhaustive search for self-consistent simultaneous mappings of all these fragments onto the protein sequence . Compared to using only the individual mappings of the spectroscopically connected fragments, the global mapping adds a powerful new constraint, which results in resolving many otherwise intractable ambiguities . In an initial application, virtually complete sequence-specific assignments were obtained for a 110 kDa homooctameric protein, 7,8-dihydroneopterin aldolase from Staphylococcus aureus.

Braz J Infect Dis, 1998 Apr, 2(2), 78 - 84
Staphylococcus aureus Nasopharyngeal Carriage Rates and Antimicrobial Susceptibility Patterns Among Health Care Workers and Their Household Contacts; Busato CR et al.; Dissemination of Staphylococcus aureus within hospitals by nasopharyngeal carriage of the organism by health care workers (HCW) has been well characterized for over 40 years, but physicians and nurses must be reminded of the extent of the problem . To determine the level of colonization among HCW in one hospital in Brazil, and to examine the potential spread to household contacts and the surrounding community, nasal swabs for S . aureus were done on 200 HCW, 87 household contacts, and 77 members of the community . The frequency of positive cultures in each group was recorded, and the organims were then tested for susceptibility to a panel of antibiotics . The average level of antibiotic resistance was calculated for each organism using a scoring technique termed rate of bacterial resistance (RBR) . Phage typing was also done . The frequency of colonization was 63/200 (31.5%) among HCW, 27/87 (31%) among their household contacts, and 14/77 (18.1%) in members of the community (p>0.05) . The level of antibiotic resistance (RBR) was significantly higher among HCW than among household contacts or the community . Phage typing revealed that 40.7% of isolates had a common phage pattern between HCW and household contacts . Among household contacts, the level of antimicrobial resistance was the same for the shared phage types as for the unique types . We conclude that nasopharyngeal carriage among HCW remains a problem, that the carriage rate is also seen among household contacts, but not in the community . Increased levels of antimicrobial resistance in the strains carried by HCW indicate that the spread of resistant organisms occurs by this mechanism . Careful control of S . aureus among HCW is an important hospital practice.

Cytokine, 2000 Dec, 12(12), 1788 - 92
Lipopolysaccharide/endotoxin induces IL-18 via CD14 in human peripheral blood mononuclear cells in vitro; Manigold T et al.; IL-18 shares activities with IL-12 in generating T-helper 1 cells and cytokine response . It mediates LPS/endotoxin lethality by IL-12 independent interferon-gamma synthesis and it induces bacteria-related organ failure . As peripheral blood mononuclear cells (PBMC) are potent producers of IL-18, we studied the regulation of IL-18 upon exposure to LPS and Staphylococcus aureus (SAC) in vitro . Freshly isolated PBMC constitutively expressed IL-18 mRNA . After unstimulated preincubation for 48 h, however, IL-18 transcripts were nearly not detectable by RT-PCR, but inducible by LPS or SAC (P<0.01) . Both LPS and SAC were potent stimuli of IL-18 protein secretion (P<0.01) . LPS-mediated IL-18 gene expression and secretion was CD14-dependent and significantly inhibited by co-incubation of PBMC with neutralizing CD14 antibody (P<0.01) . We conclude that LPS-driven IL-18 is dependent on the expression of costimulatory factors and that IL-18 inhibition might attenuate IL-18-related toxic effects .

Folia Microbiol (Praha), 1999, 44(6), 707 - 11
Anti-staphylococcal effect of enterocin in Sunar and yogurt; Laukova A et al.; Enterocin was used to control the growth of Staphylococcus aureus strains SA1 and Oxford 209P in Sunar (milk nourishment for suckling babies) and during the yogurt-making process . Reduction by three orders of magnitude was noted in the growth of SA1 strain in Sunar milk nourishment between the enterocin-containing (ES) and the control samples (CS) at 1-d cultivation . An inhibitory effect of enterocin was observed when surviving of SA1 cells were checked 6 h after the start of cultivation (2 h after enterocin application; enterocin was applied after 4 h) . Decrease in the count of Oxford 209P strain in yogurt was detected in ES after 1 d of storage in comparison with CS (10(3) and 10(0) CFU mL-1 g-1) . Thus a decrease by three orders of magnitude was found between ES and CS at the time mentioned . On the other hand, no bacteriocin activity was detected in ES after 1 d . Activity was detected only immediately after enterocin addition to ES (400 AU/mL) as well as after 1 and 3 1/2 h (200 AU/mL) . Although the slight regrowth of the indicator was obtained up to 1 week of yogurt storage, the difference between ES and CS persisted . The lowest pH of the final yogurt product was noted in the reference yogurt sample but differences among the pH values of yogurt samples were not significant.

Dermatology, 2000, 201(3), 235 - 41
An innovative topical drug formulation for wound healing and infection treatment: in vitro and in vivo investigations of a povidone-iodine liposome hydrogel; Reimer K et al.; BACKGROUND: In topical wound treatment, the combination of anti-infectious therapy and a healing-promoting moisturization has not been accomplished yet . OBJECTIVE: Evaluation of a new topical drug consisting of a povidone-iodine (PVP-I) liposome hydrogel allowing for both antiseptic and moist treatment . METHODS: Pharmaceutical formulation of a complex of PVP-I (3%) and phosphatidylcholine in a hydrogel . In vitro, interaction of the complex with relevant micro-organisms was analysed by electron microscopy . Antimicrobial activity was investigated using Staphylococcus aureus in a suspension test . Tissue toxicity was examined by an explantation test in a rodent model . A randomized clinical study on efficacy and tolerability in wound healing was carried out on 35 patients with mesh grafts in parallel groups (PVP-I liposome hydrogel vs . Bactigras) for proof of concept in humans . RESULTS: A direct interaction of the PVP-I liposomes with micro-organisms by attachment to the cell surface was documented . A significantly better microbicidal activity and tissue tolerability of the PVP-I liposome hydrogel compared to conventional PVP-I formulations was shown . The results of the clinical study, especially measurements of neo-epithelization per time and transplant loss, demonstrate significant differences in favour of the PVP-I liposome hydrogel . CONCLUSION: The novel PVP-I liposome hydrogel combines microbicidal and wound healing activities resulting in enhanced epithelization.

Chemotherapy, 2001, 47 Suppl 1, 5 - 16
The use of outpatient parenteral antimicrobial therapy in the management of osteomyelitis: data from the Outpatient Parenteral Antimicrobial Therapy Outcomes Registries; Tice A; Because osteomyelitis requires lengthy parenteral antibiotic treatment in patients who are often otherwise healthy, it lends itself well to outpatient parenteral antibiotic therapy (OPAT) . Four delivery models for OPAT are (1) self-administration at home, (2) administration by a visiting nurse in the home, (3) infusion center and (4) nursing home . Patient selection is critical to the success of any OPAT program . Clinical and microbiologic data were compiled for more than 500 osteomyelitis patients reported in a registry of OPAT cases in the United States . The most commonly isolated pathogen was Staphylococcus aureus . The antibiotics used most frequently were vancomycin and ceftriaxone . Of 255 patients assessed for bacteriologic outcome, 2 patients developed infection with a new organism and 2 failed to eliminate the causative organism by the end of OPAT therapy . Of 266 patients who were assessed for clinical outcome, 259 improved and 7 failed . Data collected by the OPAT Outcomes Registry confirms that osteomyelitis can be safely and effectively treated with intravenous antibiotics outside the hospital.

Clin Infect Dis, 2000 Dec, 31(6), 1423 - 66 Epub 2000 Nov 29.
Novelties in the field of anti-infective compounds in 1999; Bryskier A; In 1999 the number of new compounds reported in the anti-infective field decreased significantly in comparison with previous years, especially for antifungals . The reported new compounds are mainly directed against Staphylococcus aureus isolates resistant to methicillin . Few derivatives were reported in the field of anti-infectives for gram-negative bacteria . At the moment, we are in a period of discovery as we await novel compounds that could issue from new engineering.

Clin Infect Dis, 2000 Dec, 31(6), 1414 - 22 Epub 2000 Nov 29.
Multiple antibiotic-resistant bacteria in long-term-care facilities: An emerging problem in the practice of infectious diseases; Bonomo RA; Long-term-care facilities (LTCFs) are becoming a major component of the health care delivery system . The management of infections with antibiotic-resistant bacteria in elderly patients in LTCFs is presenting new challenges to our current therapeutic armamentarium . Among the enteric bacilli, resistance to ceftazidime, beta-lactam/beta-lactamase-inhibitor combinations, and trimethoprim-sulfamethoxazole present the foremost problems . Quinolone-resistant gram-negative and gram-positive bacteria are increasing in frequency because of the widespread use of these agents in empirical treatment . Among the resistant gram-positive organisms, methicillin-resistant Staphylococcus aureus, penicillin-resistant pneumococci, and vancomycin-resistant enterococci are the most feared pathogens . Education, antibiotic control measures, and fundamental epidemiological and scientific research are advocated as important preventive measures.

Clin Infect Dis, 2000 Dec, 31(6), 1380 - 5 Epub 2000 Nov 10.
Risk factors for persistent carriage of methicillin-resistant Staphylococcus aureus; Harbarth S et al.; We determined risk factors associated with persistent carriage of methicillin-resistant Staphylococcus aureus (MRSA) among 102 patients enrolled in a double-blind, placebo-controlled trial of nasally administered mupirocin ointment . MRSA decolonization was unsuccessful in 77 (79%) of 98 patients who met the criteria for evaluation . By univariate analysis, 4 variables were found to be associated with persistent MRSA colonization (P < .1 for all 4): absence of mupirocin treatment, previous fluoroquinolone therapy, > or = 2 MRSA-positive body sites, and low-level mupirocin resistance . After multivariable Cox proportional hazards modeling, the presence of > or = 2 positive body sites (adjusted hazard ratio {AHR}, 1.7; 95% confidence interval {CI}, 1.0-2.9) and previous receipt of a fluoroquinolone (AHR, 1.8; 95% CI, 1.0-3.3) were independently associated with MRSA persistence, whereas nasal mupirocin tended to confer protection (AHR, 0.6; 95% CI, 0.4-1.0) . Low-level mupirocin resistance was observed in 9 genotypically different MRSA strains and was not independently associated with chronic MRSA carriage (AHR, 1.5; 95% CI, 0.9-2.5) . Our findings suggest that multisite MRSA carriage and previous receipt of a fluoroquinolone are independent risk factors for persistent MRSA colonization.

Microb Pathog, 2000 Dec, 29(6), 357 - 61
Quantification of Staphylococcus aureus cell surface adhesins using flow cytometry; Mohamed N et al.; The initiation of many infectious diseases involves specific adhesion of bacteria to host tissue proteins and carbohydrates . Staphylococcus aureus is known to bind specifically to several proteins in the extracellular matrix (ECM) . We report the quantification of the collagen and fibronectin adhesin densities on the staphylococcal surface using flow cytometry . Our results are in agreement with previous reports on the transcription of the respective genes and demonstrate different patterns of temporal expression for the two adhesins in the strains studied . We demonstrate a convenient technique for quantification of bacterial adhesins that can be used in studies aimed at characterization of bacterial adhesion to ECM components and understanding expression of adhesins during the course of an infection .

J Pept Res, 2000 Nov, 56(5), 265 - 74
Antibacterial activity of 15-residue lactoferricin derivatives; Strom MB et al.; Lactoferricins are a class of antibacterial peptides isolated after gastric-pepsin digest of the mammalian iron-chelating-protein lactoferrin . For investigation of antibacterial activity, we prepared short synthetic derivatives of bovine, human, caprine, murine and porcine lactoferricins with 15-amino-acid residues of high sequence homology . The peptides corresponded to amino-acid residues 17-31 of the mature bovine lactoferrin . Only the bovine and caprine derivatives displayed measurable antibacterial activity, with the bovine one having a minimal inhibitory concentration of 24 microM and being 10 times more active than the caprine one against Escherichia coli . An alanine-scan of the bovine lactoferricin derivative was performed to identify specific amino acids that were important for the antibacterial activity . We found that neither of the two tryptophan residues (Trp 6 and Trp 8) present in the bovine lactoferricin derivative could be replaced by alanine without a major loss of antibacterial activity . The other lactoferricin derivatives tested contained only one tryptophan residue (Trp 6) . Modified human, caprine and porcine lactoferricin derivatives containing two tryptophan residues (Trp 6 and Trp 8) displayed minimal inhibitory concentrations of 74, 174 and 219 microM, respectively, which represented up to a six-fold increase in antibacterial activity . The alanine-scan also revealed that the antibacterial activity was increased when acetamidomethyl-protected cysteine and unprotected glutamine (Cys 3 and Gln 7) were replaced with alanine . Only the bovine lactoferricin derivative and a few of its alanine-modified derivatives displayed measurable activity against Staphylococcus aureus.

FEMS Microbiol Lett, 2000 Dec 1, 193(1), 57 - 62
Demonstration of intracellular Staphylococcus aureus in bovine mastitis alveolar cells and macrophages isolated from naturally infected cow milk; Hebert A et al.; Numerous in vitro studies have demonstrated that Staphylococcus aureus may be internalized and survive in a bovine mammary epithelial cell line . We report here the presence of internalized and living S . aureus in alveolar cells and macrophages in milk samples of bovine mastitis . We used fluorochrome labeled monoclonal antibodies, specifically recognizing surface cell markers of bovine alveolar cells and macrophages, to isolate these two types of cells using fluorescence activated cell sorting . Extracellular bacteria and DNA were previously eliminated to exclude possible contamination . In order to detect intracellular bacterial DNA inside the isolated cells, we used PCR amplification of bacterial DNA and the PCR products were analyzed by Southern blot with a specific probe for Staphylococcus . The results showed the presence of Staphylococcus DNA inside the two isolated populations of cells, confirming that S . aureus could penetrate alveolar cells and macrophages . The demonstration of the presence of intracellular living S . aureus was determined by bacteriological culture of positive samples plated onto blood agar plates and by its further identification . Our results showed for the first time that living S . aureus and its DNA are present in both alveolar cells and macrophages in chronically infected cow milk.

J Biol Chem, 2001 Mar 2, 276(9), 6299 - 305 Epub 2000 Nov 28.
Porphyromonas gingivalis DPP-7 represents a novel type of dipeptidylpeptidase; Banbula A et al.; A novel dipeptidylpeptidase (DPP-7) was purified from the membrane fraction of Porphyromonas gingivalis . This enzyme, with an apparent molecular mass of 76 kDa, has the specificity for both aliphatic and aromatic residues in the P1 position . Although it belongs to the serine class of peptidases, it does not resemble other known dipeptidylpeptidases . Interestingly, the amino acid sequence around the putative active site serine residue shows significant similarity to the C-terminal region of the Staphylococcus aureus V-8 endopeptidase . The genes encoding homologues of DPP-7 were found in genomes of Xylella fastidiosa, Shewanella putrefaciens, and P . gingivalis . It is likely that at least in P . gingivalis, DPP-7 and its homologue, in concert with other di- and tripeptidases, serve nutritional functions by providing dipeptides to this asaccharolytic bacterium.

Curr Infect Dis Rep, 2000 Oct, 2(5), 433 - 437
From Animal to Man: Tinea Barbae; Rutecki GW et al.; Dermatophytic fungi cause human infection worldwide . One clinical syndrome--tinea barbae, which closely resembles tinea capitis--is a trichophytosis involving the beard and mustache areas of the face . The fungal agents responsible for tinea barbae (Trichophyton verrucosum and Trichophyton mentagrophytes) are contracted through occupational exposure to animals infected with zoophilic dermatophytes . Tinea barbae may be confused with other facial infections, especially those caused by Staphylococcus aureus or other facial dermatophytes (usually anthrophilic) . In an afebrile patient without leucocytosis, a distinctive facial lesion, called a kerion, can be the essential diagnostic finding . Diagnosis requires suspicion based on appropriate exposure . Definitive diagnosis requires a combination of clinical examination, direct microscopic examination using potassium hydroxide, and culture confirmation . Topical treatment is not effective . Oral therapy with an antifungal (eg, terbinafine) or an azole is recommended . This article reviews these factors, as well as germane epidemiologic and prevention measures.

Curr Infect Dis Rep, 2000 Aug, 2(4), 281 - 298
Staphylococcus aureus, Platelets, and the Heart; Yeaman MR et al.; Infective endocarditis (IE) caused by Staphylococcus aureus is serious, burgeoning frequency, and growing increasingly resistant to antibiotics . S . aureus IE is associated with high morbidity and mortality rates in nosocomial and community-acquired settings . S . aureus is the most common, most virulent IE etiologic pathogen . S . aureus IE pathogenesis depends upon complex interaction among the pathogen, platelets, plasma proteins, and vascular endothelial cells . S . aureus coordinates the expression of key virulence factors required for the specific pathogenic phases of IE . Platelets, now appear to play an important role in antimicrobial host defense against S . aureus IE and other endovascular infections . Platelet microbicidal proteins are believed to significantly contribute to the antimicrobial properties of platelets; however, abnormal disposition of native or prosthetic cardiac valves is an important risk factor in S . aureus IE establishment and severity . Thus, the need to define the molecular mechanisms of S . aureus pathogenesis and host defense against IE is urgent . Understanding these mechanisms will yield new approaches for the prevention and treatment of such life-threatening cardiovascular infections due to S . aureus.

Curr Infect Dis Rep, 1999 Oct, 1(4), 328 - 333
Methicillin-Resistant Staphylococcus aureus Infections; Farr BM; Methicillin-resistant Staphylococcus aureus (MRSA) has continued to spread and cause serious nosocomial infections . Failure to control MRSA may result in higher rates of use of glycopeptides, which may, in turn, lead to higher rates of glycopeptide resistance . Resistance to glycopeptides has recently begun to appear in S . aureus . Transfer of glycopeptide-resistance genes from enterococci to S . aureus has been documented in laboratory experiments but has not yet been found in clinical isolates . Over time, MRSA is becoming more common in various subsets of the general population . Some studies claim that many MRSA-colonized outpatients and their close contacts have had no health care contacts, but these studies have usually not considered contacts in outpatient clinics . Several other recent studies have found that all or a vast majority of patients with MRSA have had frequent contact with health care providers . Failure to wash hands and disinfect equipment between patients, which has been commonly seen in studies of health care worker compliance with infection control measures, may explain much of the continuing spread . The source of spread of antibiotic-resistant microbes can be likened to an iceberg, with clinically obvious infections representing the tip of the iceberg and most of the spread coming from clinically inapparent colonized patients who represent most of the reservoir for transmission . Surveillance cultures to identify this reservoir are important to the control of spread with effective barrier precautions . Such precautions have been shown to reduce the spread of MRSA 15.6-fold compared with standard precautions.

Curr Infect Dis Rep, 1999 Jun, 1(2), 129 - 135
Echocardiography for the Diagnosis of Staphylococcus aureus Infective Endocarditis; Chamis AL et al.; Staphylococcus aureus bacteremia (SAB) is a serious and growing problem . A longstanding controversy in infectious diseases has centered around the duration of therapy for patients with SAB . Fortunately, the refinement of echocardiography and the creation of new diagnostic criteria have aided in the diagnosis of infective endocarditis in patients with SAB . These advancements have resulted in the development of an algorithm that combines clinical, microbiologic, and echocardiographic findings to stratify patients with SAB into different treatment regimens.

J Bacteriol, 2000 Dec, 182(24), 6983 - 91
Characterization of the sigma(B) regulon in Staphylococcus aureus; Gertz S et al.; The sigma(B)-dependent stress regulon in gram-positive bacteria might fulfill a physiological role in stress response and virulence similar to that of the sigma(S) regulon in Escherichia coli and other gram-negative bacteria . In order to obtain evidence for the function of the sigma(B) regulon of Staphylococcus aureus, especially in virulence control, sigma(B)-dependent stress genes were identified . The two-dimensional protein pattern of wild-type cells of S . aureus COL was compared with that of an isogenic sigB mutant . By this approach, we found that the synthesis of about 27 cytoplasmic proteins seemed to be under the positive control of sigma(B) . N-terminal sequencing of 18 proteins allowed the identification of their genes on the almost finished genome sequence of S . aureus COL and the analysis of the promoter structure . Transcriptional analyses of 11 of these genes confirmed their sigma(B) dependency, and moreover, about 7 additional sigma(B)-dependent genes were found which are cotranscribed with the newly detected genes, forming operons . Altogether, we identified 23 sigma(B)-dependent genes and their corresponding proteins . Among them are proteins probably involved in the generation of NADH or in membrane transport mechanisms . Furthermore, at least one clpC-homologous gene was localized on the S . aureus sequence solely transcribed by sigma(B) . In contrast, a second clpC-homologous gene in S . aureus forming an operon with ctsR, yacH, and yacI was sigma(B) independently expressed.

Microbios, 2000, 103(405), 97 - 106
Synergistic effect of cefepime on the phagocytic killing of Staphylococcus aureus by human polymorphonuclear leucocytes and the determination of this effect by means of nitrite production; Sultan N et al.; In this study the effect of cefepime on the phagocytosis and intracellular killing of Staphylococcus aureus by human polymorphonuclear leucocytes (PMNL) was determined . The opsonophagocytic killing of S . aureus was synergistically enhanced by cefepime at concentrations below 0.5 times the minimal inhibitory concentration (MIC), and four times the MIC at higher concentrations . The effect of cefepime on phagocytosis and the bactericidal activity of PMNL was also investigated by the measurement of nitrite levels using a Sievers analyser . According to the nitrite levels, cefepime enhanced not only the phagocytosis by PMNL 2.1-fold in the 0.5 MIC and 2.8-fold in the four MIC values but also the bactericidal activity of neutrophils 2.5-fold in the 0.5 MIC and 2.8-fold in the four MIC values, respectively . The beneficial cefepime-leucocyte interaction may explain the efficacy of cefepime against intracellular pathogens.

Arch Pharm (Weinheim), 2000 Oct, 333(10), 341 - 6
Pyridazine N-oxides . III . Synthesis and "in vitro" antimicrobial properties of N-oxide derivatives based on tricyclic indeno{2,1-c}pyridazine and benzo{f}cinnoline systems; Gavini E et al.; A number of 9H-indeno{2,1-c}pyridazine N-oxides (3a-c) and benzo{f}cinnoline N-oxides (4,5a-c) have been synthesized and tested for antimicrobial activity . All new products were inactive against Gram negative bacteria and fungi . In contrast, among the compounds synthesized, 3b, 4b and 5b showed a moderate activity against Gram positive Staphylococcus aureus and Staphylococcus epidermidis . Of the present series, the 9-nitro-benzo{f}cinnoline N-oxide 5b possessed the highest activity especially against Trichomonas vaginalis (MIC = 3.9 micrograms/ml).

Intensive Crit Care Nurs, 2000 Dec, 16(6), 357 - 66
Methicillin-resistant Staphylococcus aureus (MRSA): is there a need to change clinical practice?
Baird VL, Hawley R.
Methicillin-resistant Staphylococcus aureus (MRSA) is a virulent organism that causes significant mortality and morbidity especially to patients in critical care areas (CCAs) . MRSA can (and does in some cases) also contribute to an increased length of hospital stay and higher health care costs . The literature proposes that routine screening of patients in CCAs is an effective strategy to control MRSA . Furthermore, placing patients in contact isolation until screening results are confirmed can prevent the spread of MRSA . The policies for management of MRSA patients and the incidence of MRSA infection vary widely . The preliminary findings from this review suggest that a uniform policy regarding routine screening and infection control management for all CCA patients should be recommended . A uniform policy has the potential to reduce rates of infection, cross-contamination and associated health costs attributed to MRSA management . However, further research is required before changes to infection control policy can be recommended . The outcomes from this review will be used to increase staff awareness of current infection control practices for MRSA patients in critical care areas and encourage further research.

Eur J Cell Biol, 2000 Oct, 79(10), 672 - 9
Cellular invasion by Staphylococcus aureus involves a fibronectin bridge between the bacterial fibronectin-binding MSCRAMMs and host cell beta1 integrins; Fowler T et al.; Although Staphylococcus aureus is primarily considered an extracellular pathogen, recent evidence suggests that this bacterium can invade a variety of nonprofessional phagocytic cells . Here we investigate the early stages of cellular invasion by S . aureus and determine the bacterial and host components that are required for this process . S . aureus expresses two cell surface-associated fibronectin (FN)-binding proteins (FnbpA and FnbpB) that mediate the interaction of the bacteria with both soluble and solid-phase FN in vitro . Using a mutant of S . aureus that lacks the expression of both Fnbps, we show that the expression of either protein is necessary for efficient uptake by the mouse fibroblast line GD25beta1A . Invasion could be inhibited by soluble recombinant proteins encompassing either the FN-binding D repeat region or the A region (and B repeats) of FnbpA, suggesting that the activities of both regions are important in this process . We demonstrate that FN is also required for invasion of this cell line . In the presence of FN-depleted fetal bovine serum, the invasion level was reduced by approximately 40% compared to in the presence of whole fetal bovine serum . Invasion could be further reduced by the addition of anti-mouse FN antibodies to the assay . Finally, we utilize a mutant mouse fibroblast line, which lacks beta1 integrin expression, to demonstrate that host cell beta1 integrins are necessary for efficient cellular invasion . The level of invasion of the mutant cell line GD25 was reduced by approximately 97% compared to the beta1-expressing complemented cell line GD25beta1A . In addition, invasion of the GD25beta1A cell line could be inhibited by an RGD-containing peptide, further implicating a role for integrins in this process . Based on these observations, we put forward a model of S . aureus invasion in which host FN forms a bridge between the bacterial Fnbps and host cell beta1 integrins, leading to bacterial uptake.

Infect Control Hosp Epidemiol, 2000 Nov, 21(11), 724 - 7
Hospital- and community-based surveillance of methicillin-resistant Staphylococcus aureus: previous hospitalization is the major risk factor; Warshawsky B et al.; OBJECTIVE: The purpose of the study was to determine the incidence and risk factors for the acquisition of methicillin-resistant Staphylococcus aureus (MRSA) in our community . DESIGN: This study used a cross-sectional design to assess patients colonized or infected with MRSA . PATIENTS: The study population consisted of residents of London, Ontario, Canada, who were identified as MRSA-positive for the first time in 1997 . SETTING: All acute- and chronic-care hospitals, long-term healthcare facilities, and community physicians' offices in the city of London participated in the study . MAIN OUTCOME MEASURE: Incidence of MRSA in the community, risk factors for acquisition, especially previous hospitalization over a defined period, and strain type were evaluated . RESULTS: In 1997, 331 residents of London were newly identified as MRSA-positive, representing an annual incidence of 100/100,000 persons (95% confidence interval, 88.8-110.7) . Thirty-one (9.4%) individuals were not healthcare-facility patients in the previous month, and 11 (3.3%), 10 (3.0%), and 6 (1.8%) individuals had no such contact in the previous 3, 6, and 12 months, respectively . One hundred seventy-seven strains, including five of the isolates from patients with no healthcare-facility contact in the previous year, were typed . One hundred sixty (90.3%) of these isolates, including all typed strains from patients with no healthcare facility contact, belonged to a single clone . CONCLUSION: These findings demonstrate that the incidence of MRSA is higher than previously reported and that hospital contact is the single most important risk factor for the acquisition of MRSA in our community . Screening for MRSA in previously hospitalized patients at the time of hospitalization may reduce nosocomial spread and indirectly reduce the incidence of MRSA in the community.

Infect Control Hosp Epidemiol, 2000 Nov, 21(11), 718 - 23
"Colonization pressure" and risk of acquisition of methicillin-resistant Staphylococcus aureus in a medical intensive care unit; Merrer J et al.; OBJECTIVE: To determine the roles of "colonization pressure," work load or patient severity in patient acquisition of methicillin-resistant Staphylococcus aureus (MRSA) in intensive care units (ICUs) . DESIGN: Prospectively collected data from October 1996 through December 1998 . SETTING: A 12-bed medical ICU in a university-affiliated general hospital . PATIENTS: Patients with risk factors for MRSA admitted to the ICU were screened within 72 hours of admission and weekly thereafter . MRSA was considered imported if detected during the first 72 hours of admission and nosocomial if detected only thereafter . Three screening strategies were used on admission during three consecutive periods . INTERVENTIONS: The unit of time chosen for measurements was the week . Weekly colonization pressure (WCP) was defined as the number of MRSA-carrier patient-days/total number of patient-days . Patient severity (number of deaths, Simplified Acute Physiologic Score {SAPS} II), work load (number of admis sions, Omega score), and colonization pressure (number of MRSA carriers at the time of admission, WCP) were compared with the number of MRSA-nosocomial cases during the following week . RESULTS: Of the 1,016 patients admitted over 116 weeks, 691 (68%) were screened . MRSA was imported in 91 (8.9%) admitted patients (13.1% of screened patients) and nosocomial in 46 (4.5%) . The number of MRSA-nosocomial cases was correlated to the SAPS II (P=.007), the Omega 3 score (P=.007), the number of MRSA-imported cases (P=.01), WCP (P<.0001), and the screening period (P<.0001) . In multivariate analysis, WCP was the only independent predictive factor for MRSA acquisition (P=.0002) . Above 30% of WCP, the risk of acquisition of MRSA was approximately fivefold times higher (relative risk, 4.9; 95% confidence interval, 1.2-19.9; P<.0001) . CONCLUSION: Acquisition of MRSA in ICU patients is strongly and independently influenced by colonization pressure.

Proc Natl Acad Sci U S A, 2000 Nov 21, 97(24), 13330 - 5
Rational design of a global inhibitor of the virulence response in Staphylococcus aureus, based in part on localization of the site of inhibition to the receptor-histidine kinase, AgrC; Lyon GJ et al.; Two-component signaling systems involving receptor-histidine kinases are ubiquitous in bacteria and have been found in yeast and plants . These systems provide the major means by which bacteria communicate with each other and the outside world . Remarkably, very little is known concerning the extracellular ligands that presumably bind to receptor-histidine kinases to initiate signaling . The two-component agr signaling circuit in Staphylococcus aureus is one system where the ligands are known in chemical detail, thus opening the door for detailed structure-activity relationship studies . These ligands are short (8- to 9-aa) peptides containing a thiolactone structure, in which the alpha-carboxyl group of the C-terminal amino acid is linked to the sulfhydryl group of a cysteine, which is always the fifth amino acid from the C terminus of the peptide . One unique aspect of the agr system is that peptides that activate virulence expression in one group of S . aureus strains also inhibit virulence expression in other groups of S . aureus strains . Herein, it is demonstrated by switching the receptor-histidine kinase, AgrC, between strains of different agr specificity types, that intragroup activation and intergroup inhibition are both mediated by the same group-specific receptors . These results have facilitated the development of a global inhibitor of virulence in S . aureus, which consists of a truncated version of one of the naturally occurring thiolactone peptides.

Rev Esp Quimioter, 2000 Sep, 13(3), 271 - 5
{In vitro activity of new quinolones against clinical strains of Staphylococcus aureus of the wild type and with mutations characterized by gyrA, gyrB and grlA}; Yague Guirao G et al.; The aim of this study was to determine the in vitro activity of five quinolones against clinical strains of methicillin-susceptible and -resistant Staphylococcus aureus clinical isolates characterized at the molecular level with respect to the presence of mutations in genes coding for resistance to quinolones (grlA, gyrA and gyrB) . The relationship between the mutations found and the activities of these quinolones was also analyzed . Trovafloxacin was the most active against methicillin-susceptible S . aureus and showed good activity against methicillin-resistant S . aureus, with a MIC90 of 2 mg/l . The grlA-gyrA double mutation was the most frequent (55% of the strains) . Single mutation in grlA was detected only in 5% of strains; 39% of strains showed a wild-type genotype . The grlA-gyrA double mutants presented a high level of resistance against the fluoroquinolones tested except for trovafloxacin, with the MIC ranging between 0.5 and 4 mg/l . Wild-type strains were susceptible to all the fluoroquinolones tested and the single grlA mutants had a low level of quinolone resistance but were still below the breakpoint for resistance . Trovafloxacin and sparfloxacin were less affected by this mutation.

Rev Esp Quimioter, 2000 Sep, 13(3), 263 - 6
{Tolerability and safety of levofloxacinin long-term treatment}; Ortega M et al.; Levofloxacin is a useful quinolone for patients infected with osteomyelitis or tuberculosis . There is little information on the tolerance and safety of levofloxacin in long-term treatment . Fifteen patients (10 men and 5 women) with prosthetic joint infection or chronic osteomyelitis were analyzed . The treatment was levofloxacin (500 mg/d) and rifampicin (600 mg/d) . Controls were performed monthly during the treatment, and after that every six months . Problems that were likely related to medication were noted by medical interview . Analyses of hepatic and renal function were performed at each visit . The mean age was 64 years . Ten patients had prosthetic joint infection, two chronic osteomyelitis, two osteosynthetic device infection and one silicone graft infection . Staphylococcus aureus was isolated in eight cases, staphylococcus coagulase being negative in five, and the cultures negative in two cases . The mean duration of treatment was 3.6 months (range 2-6 months) . No adverse reactions were observed in seven patients (46%) . Occasional digestive symptoms were reported in six patients (40%), and two cases (13%) presented light diarrhea . These patients also took antiinflammatory treatment . Sleeplessness was observed in one patient (6%) . Tendinitis or alterations in hepatic function were not observed . In no case was the treatment changed due to adverse reactions . It was concluded that levofloxacin is well tolerated and safe and could be an option for infections that require long-term treatment.

J Biol Chem, 2001 Feb 23, 276(8), 5707 - 13 Epub 2000 Nov 20.
Isolation and characterization of human beta -defensin-3, a novel human inducible peptide antibiotic; Harder J et al.; The growing public health problem of infections caused by multiresistant Gram-positive bacteria, in particular Staphylococcus aureus, prompted us to screen human epithelia for endogenous S . aureus-killing factors . A novel 5-kDa, nonhemolytic antimicrobial peptide (human beta-defensin-3, hBD-3) was isolated from human lesional psoriatic scales and cloned from keratinocytes . hBD-3 demonstrated a salt-insensitive broad spectrum of potent antimicrobial activity against many potentially pathogenic microbes including multiresistant S . aureus and vancomycin-resistant Enterococcus faecium . Ultrastructural analyses of hBD-3-treated S . aureus revealed signs of cell wall perforation . Recombinant hBD-3 (expressed as a His-Tag-fusion protein in Escherichia coli) and chemically synthesized hBD-3 were indistinguishable from naturally occurring peptide with respect to their antimicrobial activity and biochemical properties . Investigation of different tissues revealed skin and tonsils to be major hBD-3 mRNA-expressing tissues . Molecular cloning and biochemical analyses of antimicrobial peptides in cell culture supernatants revealed keratinocytes and airway epithelial cells as cellular sources of hBD-3 . Tumor necrosis factor alpha and contact with bacteria were found to induce hBD-3 mRNA expression . hBD-3 therefore might be important in the innate epithelial defense of infections by various microorganisms seen in skin and lung, such as cystic fibrosis.

J Wildl Dis, 2000 Oct, 36(4), 788 - 91
Bacterial valvular endocarditis in a black bear from Labrador; McBurney S et al.; In fall 1991, a radio-collared black bear (Ursus americanus) in northern Labrador (Canada) died from valvular endocarditis caused by coagulase-positive Staphylococcus aureus, with widespread dissemination of the infection to other organs shortly before death . Apparently, this is the first reported case of bacterial valvular endocarditis in a wild black bear.

Biomaterials, 2001 Jan, 22(1), 73 - 80
In vivo application of biodegradable controlled antibiotic release systems for the treatment of implant-related osteomyelitis; Gursel I et al.; In this study the construction and in vivo testing of antibiotic-loaded polyhydroxyalkanoate rods were planned for use in the treatment of implant-related osteomyelitis . The rods were constructed of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and poly(3-hydroxybutyrate-co-4-hydroxybutyrate), carrying 50% (w/w) Sulperazone or Duocid . They were implanted in rabbit tibia in which implant-related osteomyelitis (IRO) had been induced with Staphylococcus aureus . The effectiveness of the antibiotics in the treatment of IRO was determined . The establishment of IRO with bacterial inoculation was complete after 3 weeks with 100% infection rate in all groups . There was no contamination or super-infection . Both antibiotics were found to be highly effective against the bacteria . Following the application of Sulperazone-P(3-HB-co-4-HB) rods, no infective agents could be isolated from the infection site within the 6-week test period, indicating complete treatment of the infection . Macroscopical evaluation at follow-up revealed no drainage, minimal swelling and increase in local warmth, most probably due to the surgery rather than to a reaction towards the implant . The overall scores for radiological findings by the end of 6 weeks were 0.8/5 for the antibiotic-loaded rod implanted in the right limb, and 1.1/5 for the antibiotic-free rod implanted in the left limb . There was no statistical difference between the antibiotic-loaded and antibiotic-free polymeric rods . In vivo drug release was almost complete within the first week . One interesting observation, however, was that the therapy was still very effective even when the release rate was very high . In the SEM of in vitro tested rods, the polymeric component was unchanged in 2 weeks while the drug leached out, leaving voids behind . In vivo, however, the morphology of the implant was significantly modified within 6 weeks post-implantation . Since a substantial degree of the in vivo drug release was complete within 1 week, we believe that dissolution of the drug must be the predominant mechanism through which the drug release is controlled.

Infect Immun, 2000 Dec, 68(12), 6650 - 5
Bacterial pathogens induce abscess formation by CD4(+) T-cell activation via the CD28-B7-2 costimulatory pathway; Tzianabos AO et al.; Abscesses are a classic host response to infection by many pathogenic bacteria . The immunopathogenesis of this tissue response to infection has not been fully elucidated . Previous studies have suggested that T cells are involved in the pathologic process, but the role of these cells remains unclear . To delineate the mechanism by which T cells mediate abscess formation associated with intra-abdominal sepsis, the role of T-cell activation and the contribution of antigen-presenting cells via CD28-B7 costimulation were investigated . T cells activated in vitro by zwitterionic bacterial polysaccharides (Zps) known to induce abscess formation required CD28-B7 costimulation and, when adoptively transferred to the peritoneal cavity of naive rats, promoted abscess formation . Blockade of T-cell activation via the CD28-B7 pathway in animals with CTLA4Ig prevented abscess formation following challenge with different bacterial pathogens, including Staphylococcus aureus, Bacteroides fragilis, and a combination of Enterococcus faecium and Bacteroides distasonis . In contrast, these animals had an increased abscess rate following in vivo T-cell activation via CD28 signaling . Abscess formation in vivo and T-cell activation in vitro required costimulation by B7-2 but not B7-1 . These results demonstrate that abscess formation by pathogenic bacteria is under the control of a common effector mechanism that requires T-cell activation via the CD28-B7-2 pathway.

Antimicrob Agents Chemother, 2000 Dec, 44(12), 3456 - 60
Structural and topological differences between a glycopeptide-intermediate clinical strain and glycopeptide-susceptible strains of Staphylococcus aureus revealed by atomic force microscopy; Boyle-Vavra S et al.; Novel cell surface topography was revealed on cocci from a glycopeptide-intermediate Staphylococcus aureus (GISA) clinical strain by using atomic force microscopy . The GISA isolate and its revertant had two parallel circumferential surface rings . One equatorial surface ring was observed in control strains . In vancomycin-susceptible strains, additional rings were formed in the presence of vancomycin . Ring depth measurements also revealed striking differences between the GISA strain and susceptible strains grown with or without vancomycin.

Antimicrob Agents Chemother, 2000 Dec, 44(12), 3438 - 40
Linezolid therapy of Staphylococcus aureus experimental osteomyelitis; Patel R et al.; The in vivo activity of linezolid or cefazolin against a clinical isolate of methicillin-susceptible Staphylococcus aureus (linezolid MIC, 2 microg/ml) was studied in a rat model of experimental osteomyelitis . Sixty rats with experimental S . aureus osteomyelitis were treated for 21 days with no antimicrobial, with 25 microg of linezolid per kg of body weight administered intraperitoneally twice or three times a day, or with 50 microg of cefazolin per kg administered intramuscularly three times a day . After treatment, the animals were sacrificed and the infected tibiae were processed for quantitative bacterial cultures . The results of treatment were expressed as log(10) CFU/gram of bone and analyzed by rank sum analysis . The results of linezolid treatment were not significantly different from those of untreated controls, while cefazolin treatment was significantly more active than no treatment or linezolid treatment.

Antimicrob Agents Chemother, 2000 Dec, 44(12), 3344 - 50
Mechanisms and frequency of resistance to premafloxacin in Staphylococcus aureus: novel mutations suggest novel drug-target interactions; Ince D et al.; Premafloxacin is a novel 8-methoxy fluoroquinolone with enhanced activity against Staphylococcus aureus . We found premafloxacin to be 32-fold more active than ciprofloxacin against wild-type S . aureus . Single mutations in either subunit of topoisomerase IV caused a four- to eightfold increase in the MICs of both quinolones . A double mutation (gyrA and either grlA or grlB) caused a 32-fold increase in the MIC of premafloxacin, while the MIC of ciprofloxacin increased 128-fold . Premafloxacin appeared to be a poor substrate for NorA, with NorA overexpression causing an increase of twofold or less in the MIC of premafloxacin in comparison to a fourfold increase in the MIC of ciprofloxacin . The frequency of selection of resistant mutants was 6.4 x 10(-10) to 4.0 x 10(-7) at twofold the MIC of premafloxacin, 2 to 4 log(10) less than that with ciprofloxacin . Single-step mutants could not be selected at higher concentrations of premafloxacin . In five single-step mutants, only one previously described uncommon mutation (Ala116Glu), and four novel mutations (Arg43Cys, Asp69Tyr, Ala176Thr, and Pro157Leu), three of which were outside the quinolone resistance-determining region (QRDR) were found . Genetic linkage studies, in which incross of grlA(+) and outcross of mutations were performed, showed a high correlation between the mutations and the resistance phenotypes, and allelic exchange experiments confirmed the role of the novel mutations in grlA in resistance . Our results suggest that although topoisomerase IV is the primary target of premafloxacin, premafloxacin appears to interact with topoisomerase IV in a manner different from that of other quinolones and that the range of the QRDR of grlA should be expanded.

Infect Control Hosp Epidemiol, 2000 Oct, 21(10), 653 - 5
The utility of polysporin ointment in the eradication of methicillin-resistant Staphylococcus aureus colonization: a pilot study; Fung S et al.; We evaluated the efficacy of an ointment containing bacitracin, polymyxin B, and gramicidin for the eradication of colonization by methicillin-resistant Staphylococcus aureus in 11 medical patients, 10 (91%) of whom had previously failed a 1-week course of topical mupirocin . Mupirocin resistance was documented in 5 (45%) of 11 patients . Successful decolonization was achieved in 9 (82%) of 11 patients (based on 2 months of follow-up).

Mem Inst Oswaldo Cruz, 2000 Nov-Dec, 95(6), 777 - 82
Molecular epidemiology of methicillin resistant Staphylococcus aureus isolated from newborns in a hospital in Rio de Janeiro, Brazil; Loureiro MM et al.; Methicillin resistant Staphylococcus aureus (MRSA) is an organism that is frequently transmitted in hospitals and perinatal units . The MRSA is considered a public health problem in neonatology because of its strong potential for dissemination in the wards associated with high rates of morbidity and mortality . In this study we describe the bacteriological, epidemiological and molecular characteristics of MRSA isolated from anterior nares and blood cultures of newborns hospitalized in a public maternity hospital in the city of Rio de Janeiro, Brazil . The frequency of MRSA isolated from nasal swabs of newborns was 47.8% (43/90) . The genetic analysis of MRSA strains from anterior nares, showed 8 different pulsed field gel electrophoresis patterns (PFGE) . Upon analysis of PFGE patterns of the 12 MRSA strains isolated from blood cultures, 8 different patterns were observed, 9 (75%) strains were genetic related to nasal secretion isolates patterns . In conclusion, our data demonstrate the importance of screening of newborns for the presence of MRSA in Brazilian hospitals and the usefulness of genetic typing of these pathogen during epidemiologic studies . This should lead to a better knowledge on the significancy and spreading of MRSA in the hospitals.

J Food Prot, 2000 Nov, 63(11), 1487 - 91
Genotypes and enterotoxicity of Staphylococcus aureus isolated from the hands and nasal cavities of flight-catering employees; Hatakka M et al.; Hand and nasal samples of flight-catering staff were collected from 1995 to 1997 to find employees carrying Staphylococcus aureus . Altogether 153 hand samples and 136 nose samples were taken . Nasal sampling showed a higher prevalence of S . aureus among food handlers (29%) than hand sampling (9%) . A high proportion of the strains (46%) were enterotoxigenic, and a considerable amount of food handlers carried enterotoxigenic S . aureus, 6% and 12% according to hand and nasal sampling, respectively . Pulsed-field gel electrophoresis macrorestriction profiles revealed a total of 32 different types associated with the 35 employees carrying S . aureus . In most cases, the same type colonized both the hand and nose of a person . Despite the wide variety of types found, one strain colonized five persons and the second most common strain was associated with four food handlers . The predominant toxin produced was B, which was produced by the most common strain . The results showed that nasal sampling is a good way to detect S . aureus carriers, whereas hand sampling may fail to reveal carriers . The high proportion of enterotoxigenic strains show that a food handler harboring S . aureus must be considered a potential source of enterotoxigenic strains for airline meals.

J Infect Dis, 2001 Jan 1, 183(1), 65 - 69 Epub 2000 Nov 10.
Enhanced extracellular growth of Staphylococcus aureus in the presence of selected linear peptide fragments of human interleukin (IL)-1beta and IL-1 receptor antagonist; Kanangat S et al.; Replication of Staphylococcus aureus is significantly enhanced in the presence of recombinant interleukin (IL)-1beta . In this study, specific binding of IL-1beta to the surface of S . aureus significantly increased growth of S . aureus in the presence of IL-1beta and IL-1ra in a concentration-dependent manner . Although IL-1ra enhanced the growth of S . aureus, there was a significant reduction in IL-1beta-mediated growth enhancement of S . aureus when 25-fold excess amounts of IL-1ra (in comparison with the IL-1beta concentration) were present in the culture medium . Thus, IL-1beta may influence the growth of S . aureus through a receptor-mediated event . By using 5 linear peptides spanning limited regions of IL-1beta, the growth-promoting regions were localized to amino acid residues 118-147 and 208-240 . These results build on the newly evolved concept of direct interactions between the soluble mediators of inflammation and infectious agents.

Arch Inst Cardiol Mex, 2000 Jul-Aug, 70(4), 384 - 90
{Infective endocarditis in intravenous drug addicts}; Aguilar JA et al.; Infective endocarditis is a frequent complication in intravenous drugs abusers . It is evident that in recent years this problem has increases as a consequence of the growing number of drug addicts . We review the clinical files of patients who entered the Regional General Hospital No . 20 IMSS in the City of Tijuana Mexico between May 1994 and May 1998 with diagnosis of infective endocarditis and had evidence intravenous abuse . Eight patients were included in the study . None of them had preexisting valve abnormalities . The infection involved right-sided values in 62.5% of cases left-sided values in 12.5%, and both sides in 12.5% of cases Staphylococcus aureus was the infecting germ in 50% of the cases . Survival of patients with right infective endocarditis was 75% and only 25% of them required surgical intervention . The mortality of infection in left side was 75% and 100% if infection involved both sides . Infective endocarditis in drugs abusers has a favorable prognosis when right sided valves are affected . Mortality rates are higher in patients with left-sided involvement.

Arch Otolaryngol Head Neck Surg, 2000 Nov, 126(11), 1383 - 5
Methicillin-resistant Staphylococcus aureus: pediatric otitis; Santos F et al.; BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is a potentially lethal organism in pediatric patients . MRSA is an uncommon otologic pathogen that requires special diagnostic and therapeutic intervention . METHODS: Three pediatric patients with community-acquired MRSA otologic infections were identified during 1999 . SETTING: Tertiary care ear institution . RESULTS: All patients required intravenous antibiotic therapy to achieve resolution of the infections . CONCLUSIONS: MRSA in children can be community acquired and can cause otitis externa, otitis media with otorrhea, or acute mastoiditis; intravenous therapy that includes vancomycin is necessary for resolution.

Clin Infect Dis, 2000 Nov, 31(5), 1306 - 8
An outbreak of Staphylococcus aureus strains with reduced susceptibility to glycopeptides in a French general hospital; Pina P et al.; We describe the isolation of Staphylococcus aureus isolates with glycopeptide heteroresistant subpopulation from 15 patients (11 with colonizations and 4 with infections) in a French hospital . Non of the patients were previously treated with glycopeptides . The 15 isolates belonged to 2 different pulsotypes unrelated to other methicillin-resistant S . aureus isolates from the same hospital.

Clin Infect Dis, 2000 Nov, 31(5), 1295 - 9
Association between nasal carriage of Staphylococcus aureus and infection in liver transplant recipients; Bert F et al.; We reviewed the records of 87 patients who underwent liver transplantation and who were screened by use of nasal swabs on the day before surgery . Twenty-four patients harbored methicillin-susceptible Staphylococcus aureus (MSSA), and 8 harbored methicillin-resistant S . aureus (MRSA) . MSSA infection occurred in 3 (12.5%) of 24 MSSA carriers and in 2 (3.2%) of 63 noncarriers (nonsignificant) . In contrast, MRSA infection occurred more frequently in MRSA carriers (7 {87.5%} of 8) than in MRSA noncarriers (8 {10.1%} of 79; P<.001) . Nasal carriage of MRSA is associated with a very high risk of MRSA infection in liver transplant recipients.

Clin Infect Dis, 2000 Nov, 31(5), 1170 - 4 Epub 2000 Nov 07.
Staphylococcus aureus bacteremia: predictors of 30-day mortality in a large cohort; Mylotte JM et al.; We performed a retrospective study of a large cohort of patients who had episodes of Staphylococcus aureus bacteremia (SAB) from January 1995 through February 1999 at 1 medical center to identify predictors of 30-day mortality in SAB . Among 293 patients with episodes of SAB, 68 died (23.2%) within 30 days of onset . There was no significant difference in 30-day mortality associated with treatment with vancomycin, a beta-lactam, or a miscellaneous group of antimicrobial agents (P=.180) . By logistic regression, an acute physiology score (a component of the acute physiology and chronic health evaluation {APACHE III}) >60 at onset of SAB was the most important predictor of 30-day mortality (odds ratio {OR}, 15.7) . Other significant predictors were lung (OR, 5.8) or unknown (OR, 4.1) focus of SAB, age > or =65 years (OR, 2.0), and diabetes mellitus (OR, 2.4) . Future investigators of SAB should take into consideration acute severity of illness at onset as well as other factors when evaluating or comparing outcomes.

J Hosp Infect, 2000 Nov, 46(3), 236 - 7
Tea tree oil as an alternative topical decolonization agent for methicillin-resistant Staphylococcus aureus; Caelli M et al.; The combination of a 4% tea tree oil nasal ointment and 5% tea tree oil body wash was compared with a standard 2% mupirocin nasal ointment and triclosan body wash for the eradication of methicillin-resistant Staphylococcus aureus carriage . The tea tree oil combination appeared to perform better than the standard combination, although the difference was not statistically significant due to the small number of patients .

J Hosp Infect, 2000 Nov, 46(3), 216 - 21
Long-term MRSA carriage in hospital patients; MacKinnon MM et al.; A retrospective study was performed to determine the frequency of and risk factors for long-term carriage of methicillin-resistant Staphylococcus aureus amongst 79 patients who initially acquired MRSA during hospital admission and were re-admitted at least once during the study period (28 months in total) . Of the 52 patients who were re-screened during their re-admissions, 33 (63%) had positive MRSA screens on at least one re-screening and 19 (37%) had all negative screens . Patients whose case notes had been tagged were more likely to have screens performed . Of the potential risk factors assessed, only the presence of skin lesions significantly increased the risk of prolonged MRSA carriage (P = 0.032) . Evaluation of the effect of anti-MRSA eradication treatment showed that patients who were subsequently MRSA negative on all re-admissions were more likely to have received some form of anti-MRSA treatment than those who remained positive on at least one re-admission (P = 0.048) . The results show that the strain of MRSA at our hospitals (predominantly EMRSA 15) is associated with prolonged carriage in certain patients and that attempts at eradication often do not affect the duration of carriage . This has infection control implications for the management of known MRSA positive patients re-admitted to hospital .

Adv Ren Replace Ther, 2000 Oct, 7(4), 280 - 8
Peritoneal infections; Piraino B; Peritoneal dialysis related infections include infection of the catheter exit site, subcutaneous pathway, or effluent . Exit-site infections, predominately owing to Staphylococcus aureus, are defined as purulent drainage at the exit site, although erythema may be a less serious type of exit-site infection . Tunnel infections are underdiagnosed clinically, and sonography of the tunnel is useful to delineate the extent of the infection and to evaluate response to antibiotic therapy . S aureus infections occur more frequently in S aureus carriers and immunosuppressed patients and can be reduced by mupirocin prophylaxis either intranasally or at the exit site . Patients with peritonitis present with cloudy effluent and usually pain, although 6% of patients may initially have pain without cloudy effluent . A white blood cell count of 100 or greater per microL, 50% of which are polymorphonuclear cells, has long been the hallmark of peritonitis . Empiric therapy is controversial, with some recommending cefazolin and others vancomycin (with cefatazidime for Gram-negative coverage) . The choice should depend on the center's antibiotic sensitivity profile; those centers with a high rate of Enterococcus- or methicillin resistant organisms should use vancomcycin . Peritonitis episodes occurring in association with a tunnel infection with the same organism seldom resolve with antibiotics and require catheter removal . Other indications for catheter removal are refractory peritonitis, relapsing peritonitis, tunnel infection with inner-cuff involvement that does not respond to antibiotic therapy (based on ultrasound criteria), fungal peritonitis, and enteric peritonitis owing to intra abdominal pathology . Centers can reduce dialysis related infections to very low levels by proper catheter selection and insertion, careful selection and training of patients, avoidance of spiking techniques, and use of antibiotic prophylaxis against S . aureus . Further research is required to identify methods to reduce the risk of enteric peritonitis .

Lancet, 2000 Oct 14, 356(9238), 1307 - 12
Effectiveness of a hospital-wide programme to improve compliance with hand hygiene . Infection Control Programme; Pittet D et al.; BACKGROUND: Hand hygiene prevents cross infection in hospitals, but compliance with recommended instructions is commonly poor . We attempted to promote hand hygiene by implementing a hospital-wide programme, with special emphasis on bedside, alcohol-based hand disinfection . We measured nosocomial infections in parallel . METHODS: We monitored the overall compliance with hand hygiene during routine patient care in a teaching hospital in Geneva, Switzerland, before and during implementation of a hand-hygiene campaign . Seven hospital-wide observational surveys were done twice yearly from December, 1994, to December, 1997 . Secondary outcome measures were nosocomial infection rates, attack rates of methicillin-resistant Staphylococcus aureus (MRSA), and consumption of handrub disinfectant . FINDINGS: We observed more than 20,000 opportunities for hand hygiene . Compliance improved progressively from 48% in 1994, to 66% in 1997 (p<0.001) . Although recourse to handwashing with soap and water remained stable, frequency of hand disinfection substantially increased during the study period (p<0.001) . This result was unchanged after adjustment for known risk factors of poor adherence . Hand hygiene improved significantly among nurses and nursing assistants, but remained poor among doctors . During the same period, overall nosocomial infection decreased (prevalence of 16.9% in 1994 to 9.9% in 1998; p=0.04), MRSA transmission rates decreased (2.16 to 0.93 episodes per 10,000 patient-days; p<0.001), and the consumption of alcohol-based handrub solution increased from 3.5 to 15.4 L per 1000 patient-days between 1993 and 1998 (p<0.001) . INTERPRETATION: The campaign produced a sustained improvement in compliance with hand hygiene, coinciding with a reduction of nosocomial infections and MRSA transmission . The promotion of bedside, antiseptic handrubs largely contributed to the increase in compliance.

Peptides, 2000 Sep, 21(9), 1301 - 11
Prevention of diseases caused by Staphylococcus aureus using the peptide RIP; Balaban N et al.; Staphylococcus aureus causes many diseases including cellulitis, keratitis, osteomyelitis, septic arthritis and mastitis . The heptapeptide RIP has been shown to prevent cellulitis in mice, which was induced by S . aureus strain Smith diffuse . Here we show that RIP can also significantly reduce the overall pathology and delay the onset of disease symptoms in several other models of S . aureus infections, including: keratitis (tested in rabbits against S . aureus 8325-4), osteomyelitis (tested in rabbits against S . aureus MS), mastitis (tested in cows against S . aureus Newbould 305, AE-1, and environmental infections) and septic arthritis (tested in mice against S . aureus LS-1) . These findings substantiate that RIP is not strain specific in its inhibitory activity and that RIP is an effective inhibitor of bacterial pathology at multiple body sites following diverse routes and doses of administration . These findings strongly evidence the potential value of RIP as a chemotherapeutic agent.

Nephrol Dial Transplant, 2000 Nov, 15(11), 1782 - 7
Renal pathological findings in infective endocarditis; Majumdar A et al.; BACKGROUND: Accounts of renal pathological findings in infective endocarditis are mostly based on studies from many years ago . We reviewed a group of patients with infective endocarditis in the light of modern concepts of renal pathology, including the largest reported series of renal biopsies in this condition . METHODS: Renal tissue was available for retrospective study from 62 patients with confirmed infective endocarditis out of 354 diagnosed with the disease between 1981 and 1998 inclusive . Twenty patients had a renal biopsy and 42 a necropsy . RESULTS: Common renal lesions noted were localized infarcts in 31%, noted only in necropsy material, and acute glomerulonephritis in 26%, noted in biopsy and necropsy material . The commonest type of glomerulonephritis was vasculitic, without deposition of immunoproteins in glomeruli . Of the renal infarcts over half were due to septic emboli, mostly in patients infected with Staphylococcus aureus . Acute interstitial nephritis was found in 10% but was more common in biopsy material and seemed attributable to antibiotics . Renal cortical necrosis found in 10% was apparent only at necropsy . There were various other findings in the kidney . CONCLUSIONS: The kidneys are commonly affected in infective endocarditis by a variety of complications of clinical significance . The commonest type of glomerulonephritis does not appear to be attributable to deposition of immune complexes . A renal biopsy may be helpful in the investigation of renal impairment in a patient with infective endocarditis.

Inflamm Res, 2000 Sep, 49(9), 486 - 96
Kinetics of cells and cytokines during immune-mediated inflammation in the mammary gland of cows systemically immunized with Staphylococcus aureus alpha-toxin; Riollet C et al.; OBJECTIVE: To examine changes in inflammatory mediators, lymphocyte subpopulations and neutrophil activation that occur during an immune-mediated recruitment of neutrophils in the mammary gland . SUBJECTS: 11 clinically healthy cows . TREATMENT: 5 cows received 2 subcutaneous injections of 30 microg of alpha-toxin of Staphylococcus aureus, two months apart . Three months after the last immunization, 5 microg of alpha-toxin were injected, via the teat end, in one randomly selected quarter of the 5 immunized cows and of the 6 unimmunized cows (control group) . METHODS: Blood and milk samples were collected at several times during 4 days post-challenge . Blood and milk cells were purified to be stained with specific mAbs and analysed by flow cytometry, or to be used for cytokine RT-PCR . Bovine serum albumin, haptoglobin, cytokines and C5a were also analysed in milk or plasma samples using radial immunodiffusion assay or ELISA . RESULTS: Large amounts of cells (> 1 million/ml of milk) were recruited in the quarters of the immunized cows, whereas no recruitment occurred in the control group . In blood of immunized animals, haptoglobin was present and expression of surface adhesion molecules on neutrophils was modified whereas no change was observed concerning the lymphocyte subpopulations . On milk-derived neutrophils, the expression of CD11b and CD18 was upregulated compared to blood, in contrast to CD62L that was downregulated . The CD8+ cells were recruited as soon as 12 h post-challenge, in contrast to the CD4+ cells, 96 h post-challenge . No IL-1beta, TNF-alpha, IL-8 and C5a were detected using ELISA . mRNA of IL-1alpha, IL-1beta, IL-6, TNF-alpha, IL-8 and IL-12 were found in almost all the samples . CONCLUSIONS: The immunization triggered an early and massive neutrophil recruitment from the blood into the milk compartment as well as the recruitment of a cytotoxic/suppressor lyphocyte population during the early acute phase response . These results could help to devise new vaccinal strategies to fight against staphylococcal mastitis.

Lett Appl Microbiol, 2000 Nov, 31(5), 368 - 73
Rapid differentiation of Staphylococcus aureus from staphylococcal species by arbitrarily primed-polymerase chain reaction; Benito MJ et al.; An arbitrarily primed-polymerase chain reaction (AP-PCR) method was optimized to differentiate Staphylococcus aureus from other staphylococcal species, using DNA from crude cell extract . From the different assays carried out, the best resolution of the band patterns was obtained when the reaction mixture contained 200 micromol l(-1) dNTPs, 200 ng primer, 1 U Taq DNA polymerase and 3 mmol l(-1) MgCl2 and the amplification conditions were: initial denaturation of 94 degrees C for 1 min, primer annealing of 30 degrees C for 1.5 min, DNA extension at 55 degrees C for 5 min and final extension at 55 degrees C for 5 min . The results of the characterization of the staphylococcal isolates by AP-PCR are in accordance with those of the biochemical identification by the API Staph System, time of analysis of the AP-PCR being only 6-7 h . Thus, this technique could be a useful method for microbial quality assurance.

Eur J Immunol, 2000 Oct, 30(10), 3039 - 48
Identification of centerin: a novel human germinal center B cell-restricted serpin; Frazer JK et al.; For naive B cells to mature in response to antigen triggering and become either plasma cells or memory B cells, a complex array of events takes place within germinal centers (GC) of secondary lymphoid organs . With the long-term objective of defining and characterizing molecules that control the generation of GC, we have subtracted RNA messages derived from highly purified B cells at the follicular mantle stage of differentiation from GC B cells . Using this approach, we have identified a novel molecule, centerin, belonging to the family of serine-protease inhibitors or serpins . Transcription of centerin is highly restricted to GC B cells and their malignant counterparts, Burkitt's lymphoma lines . The putative centerin protein shares the highest sequence identity with thyroxine-binding globulin and possesses arginine/serine at its P1/P1' active site, suggesting that it interacts with a trypsin-like protease(s) . In addition, several other sequence features of centerin also indicate that it serves as a bonafide protease inhibitor . Finally, we demonstrate differentially up-regulated transcription of this novel gene by resting, naive B cells stimulated in vitro via CD40 signaling, while Staphylococcus aureus Cowan strain-mediated B cell activation fails to generate this reponse . Because CD40 signaling is required for naive B cells to enter the GC reaction and for GC B cells to survive, it is likely that centerin plays a role in the development and/or sustaining of GC.

Can J Microbiol, 2000 Oct, 46(10), 920 - 6
A CD-1 mouse model of infection with Staphylococcus aureus: influence of gender on infection with MRSA and MSSA isolates; Yanke SJ et al.; Staphylococcus aureus is an important pathogen of humans and other animals, causing bacteremia, abscessation, toxemia, and other infectious diseases . An animal model using CD-1 mice was developed to study the pathogenesis of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA) . When inoculated into the CD-1 mouse model, it was shown that both MSSA isolates, (HR 78 and CSA-1) and MRSA isolates (MRSA 456 and MRSA 457) led to chronic infection of the kidney . Female CD-1 mice inoculated with MRSA 456 proved to be more susceptible to infection and mortality than their male counterparts . Castrated mice became more susceptible to infection than intact male mice, suggesting a hormonal involvement in the infection process.

J Immunol, 2000 Nov 15, 165(10), 5392 - 6
Cutting edge: TLR2-deficient and MyD88-deficient mice are highly susceptible to Staphylococcus aureus infection; Takeuchi O et al.; Toll-like receptor (TLR) family acts as pattern recognition receptors for pathogen-specific molecular patterns . We previously showed that TLR2 recognizes Gram-positive bacterial components whereas TLR4 recognizes LPS, a component of Gram-negative bacteria . MyD88 is shown to be an adaptor molecule essential for TLR family signaling . To investigate the role of TLR family in host defense against Gram-positive bacteria, we infected TLR2- and MyD88-deficient mice with Staphylococcus aureus . Both TLR2- and MyD88-deficient mice were highly susceptible to S . aureus infection, with more enhanced susceptibility in MyD88-deficient mice . Peritoneal macrophages from MyD88-deficient mice did not produce any detectable levels of cytokines in response to S . aureus . In contrast, TLR2-deficient macrophages produced reduced, but significant, levels of the cytokines, and TLR4-deficient macrophages produced the same amounts as wild-type cells, indicating that S . aureus is recognized not only by TLR2, but also by other TLR family members except for TLR4.

Can J Cardiol, 2000 Oct, 16(10), 1282 - 8
Isolated pulmonic valve endocarditis in healthy hearts: a case report and review of the literature; Ramadan FB et al.; The case of a 53-year-old man with isolated pulmonic valve endocarditis in a structurally normal heart is presented . The patient had a history of chronic obstructive pulmonary disease and was admitted to hospital with an apparent exacerbation with pneumonia . Blood cultures grew Staphylococcus aureus, and an echocardiogram identified a large vegetation on the pulmonic valve in a structurally normal heart . He was unsuccessfully treated with antibiotics and eventually required pulmonic valve replacement . The literature from 1960 to 1999 identified only 36 reported cases of pulmonic valve endocarditis in structurally normal hearts . The present report underscores the importance of suspecting pulmonic valve endocarditis in patients with multiple pulmonary lesions, and discusses the predisposing factors, clinical features, diagnostic role of echocardiography and the potential benefits of early surgical treatment.

Comp Biochem Physiol A Mol Integr Physiol, 2000 Oct, 127(2), 237 - 47
Host defense function in neutrophils from the American bison (Bison bison); Swain SD et al.; Selected host defense functions of neutrophils isolated from American bison (Bison bison) were characterized and compared with those of cattle (Bos taurus) . Bison neutrophils had a robust chemotactic response to both IL-8 and LTB(4), with maximal responses occurring at 10(-7) M (IL-8) and 10(-8) M (LTB(4)) . The magnitude of the chemotactic response to IL-8 was similar in bison and bovine neutrophils (except at 10(-7) M IL-8, where bison had a stronger response) . In response to LTB(4), bison neutrophils had a much stronger chemotaxis at both 10(-8) and 10(-7) M than did bovine cells . Production of reactive oxygen species (ROS) in response to phorbol myristate acetate (PMA) and opsonized zymosan (OpZ) was similar between bison and bovine neutrophils . However, the production of ROS in bison neutrophils stimulated with OpZ was primarily intracellular, while extracellular release of ROS was evident in bovine neutrophils stimulated with OpZ . Like bovine neutrophils, bison neutrophils did not generate a respiratory burst in response to fMLF . Granules prepared from bison neutrophils had potent direct killing action on the Gram-negative bacteria Escherichia coli but failed to kill the Gram-positive bacteria Staphylococcus aureus and, at intermediate doses, actually had a permissive effect for this bacteria . Thus, bison neutrophils have potent host defense capabilities similar in quality to those of bovine neutrophils; however, unique differences are present, which may allow bison neutrophils to respond to the distinct immunological challenges that bison encounter.

FEMS Immunol Med Microbiol, 2000 Nov, 29(3), 213 - 20
Identification of a novel antigen from Staphylococcus epidermidis; Lang S et al.; A genomic DNA library of Staphylococcus epidermidis NCTC 11047 was constructed, using the Lambda Zap Express cloning vector, and screened with serum collected from a patient with S . epidermidis endocarditis . Sequence analysis of a 30 kDa cloned protein, termed staphylococcal secretory antigen, SsaA, identified a novel protein not previously reported in S . epidermidis . SsaA showed strong homology with two other staphylococcal proteins: SceB from Staphylococcus carnosus and a staphyloxanthin biosynthesis protein from Staphylococcus aureus . Further investigation revealed SsaA to be a highly antigenic protein that was expressed in vivo and could be recovered from whole cells and from the culture supernatant . A combination of Western blot analysis and PCR screening identified SsaA or a homologue in 103/103 staphylococcal strains . SsaA-like genes were not detected in other Gram-positive bacteria of medical importance or a number of Gram-negative organisms . Elevated anti-SsaA IgG antibody levels were detected in sera of five patients with S . epidermidis endocarditis but not in patients with other S . epidermidis infections, endocarditis of other aetiologies or patients with no evidence of infection . The expression of SsaA during episodes of S . epidermidis endocarditis suggests a virulence role specific to the pathogenesis of this infectious disease.

Nat Med, 2000 Nov, 6(11), 1275 - 7
Toxin in bullous impetigo and staphylococcal scalded-skin syndrome targets desmoglein 1; Amagai M et al.; Exfoliative toxin A, produced by Staphylococcus aureus, causes blisters in bullous impetigo and its more generalized form, staphylococcal scalded-skin syndrome . The toxin shows exquisite specificity in causing loss of cell adhesion only in the superficial epidermis . Although exfoliative toxin A has the structure of a serine protease, a target protein has not been identified . Desmoglein (Dsg) 1, a desmosomal cadherin that mediates cell-cell adhesion, may be the target of exfoliative toxin A, because it is the target of autoantibodies in pemphigus foliaceus, in which blisters form with identical tissue specificity and histology . We show here that exfoliative toxin A cleaved mouse and human Dsg1, but not closely related cadherins such as Dsg3 . We demonstrate this specific cleavage in cell culture, in neonatal mouse skin and with recombinant Dsg1, and conclude that Dsg1 is the specific receptor for exfoliative toxin A cleavage . This unique proteolytic attack on the desmosome causes a blister just below the stratum corneum, which forms the epidermal barrier, presumably allowing the bacteria in bullous impetigo to proliferate and spread beneath this barrier.

J Antimicrob Chemother, 2000 Nov, 46(5), 775 - 84
Treatment of methicillin-resistant staphylococcus aureus infections with quinupristin-dalfopristin in patients intolerant of or failing prior therapy . For the Synercid Emergency-Use Study Group; Drew RH et al.; Safety and efficacy of quinupristin-dalfopristin (an injectable streptogramin antibiotic) were evaluated in the treatment of a variety of infections due to methicillin-resistant Staphylococcus aureus (MRSA) in patients either intolerant of or failing prior therapy . The influence of resistance phenotypes on treatment outcome was also assessed . This worldwide, multicentre, open-label, non-comparative, emergency-use clinical study enrolled patients with one or more of nine predefined, culture-confirmed infections with MRSA, who had no clinically appropriate alternative antibiotic therapy . The recommended quinupristin-dalfopristin dose was 7.5 mg/kg administered iv every 8 h for a duration judged appropriate by the investigator . There were no restrictions on prior or concomitant treatment with other antibiotics . Clinical, microbiological and laboratory assessments were performed at baseline, during study drug treatment, within 24 h after the last dose, and 7-21 days post-therapy . Ninety patients {age (mean +/- S.D.) 57.4 +/- 18.5 years} with significant underlying medical illnesses were treated at 63 centres in five countries . The most common indications were bone and joint infection (44.4% of patients) and skin and skin structure infection (16.7%) . The mean (+/- S.D.) daily dose and treatment duration was 20.2 +/- 2.9 mg/kg/day for 28.5 +/- 22.3 days, most frequently administered every 8 h . The overall success rate (defined as a clinical outcome of either cure or improvement and a bacteriological outcome of eradication or presumed eradication) was 71.1% in the all-treated population (n = 90) and 66.7% in patients who were both clinically and bacteriologically evaluable (n = 27) . Success rates for endocarditis, respiratory tract infection and bacteraemia of unknown source were below the population mean . The macrolide-lincosamide-streptogramin type B resistance phenotype did not appear to alter the response rate . The most common non-venous adverse events related to study medication were arthralgias (10.8%), myalgias (8.6%) and nausea (8.6%) . Quinupristin-dalfopristin should be considered as a treatment option for infections caused by MRSA, especially in patients intolerant of or failing alternate therapy.

J Clin Microbiol, 2000 Nov, 38(11), 3926 - 31
Community acquisition of gentamicin-sensitive methicillin-resistant Staphylococcus aureus in southeast Queensland, Australia; Nimmo GR et al.; Community-acquired methicillin-resistant Staphylococcus aureus (MRSA) susceptible to gentamicin has been reported in a number of countries in the 1990s . To study the acquisition of gentamicin-sensitive MRSA (GS-MRSA) in southeast Queensland and the relatedness of GS-MRSA to other strains of MRSA, 35 cases of infection due to GS-MRSA from October 1997 through September 1998 were examined retrospectively to determine the mode of acquisition and risk factors for MRSA acquisition . Thirty-one isolates from the cases were examined using a variety of methods (antibiotyping, phage typing, pulsed-field gel electrophoresis {PFGE} fingerprinting, and coagulase typing by restriction analysis of PCR products) and were compared with strains of local hospital-acquired gentamicin-resistant MRSA (GR-MRSA) and of Western Australian MRSA (WA-MRSA) . Only 6 of 23 cases of community-acquired GS-MRSA had risk factors for MRSA acquisition . Twenty of 21 isolates from cases of community-acquired infection were found to be related by PFGE and coagulase typing and had similar phage typing patterns . Hospital- and nursing home-acquired GS-MRSA strains were genetically and phenotypically diverse . Community-acquired GS-MRSA strains were not related to nosocomial GR-MRSA or WA-MRSA, but phage typing results suggest that they are related to GS-MRSA previously reported in New Zealand.

Pediatr Int, 2000 Oct, 42(5), 528 - 33
Sepsis in children; Oda K et al.; BACKGROUND: Sepsis remains lethal to children . At our institution, we have noted that approximately 2% of all hospitalized patients have had sepsis . In the present study, we analyzed episodes of sepsis that occurred in our ward . METHODS: Sepsis that occurred in our institution between January 1984 and December 1998 was reviewed and analyzed . RESULTS: Three hundred and sixty-six episodes of sepsis in 244 admitted patients were analyzed . Sepsis occurred in approximately 2% of all hospitalized patients . Forty-three of 244 patients were under 1 year of age . Eighty-seven percent (212/244) of cases had underlying diseases . Hematologic disorders or neoplasms were the most common underlying disease, comprising 55% of all patients (133/244) . Two-hundred and fifty-one of 366 episodes of sepsis were acquired during hospitalization . We identified 409 causative agents . There were 25 polymicrobial infections (25/366; 7%) . Gram-positive bacteria comprised 68% of all organisms (280/409) . Staphylococcus aureus was the most common organism, comprising 18% of causing agents (75/409) . Sixty-six organisms came from the insertion of a central venous catheter . Eighty-one patients experienced recurrent episodes of sepsis . In terms of complications, respiratory distress was the most common complication (36 episodes) and there were 15 episodes of shock . Thirty-seven patients died of sepsis . Sepsis caused by Gram-negative bacteria showed significantly higher mortality than Gram-positive bacteria (11/43 (26%) vs 15/146 (10%); P= 0.053) . CONCLUSIONS: In our institution, approximately 20% of septic patients were under 1 year of age and 90% had underlying diseases . The causative agents of sepsis affected the outcome.

Boll Chim Farm, 2000 Jul-Aug, 139(4), 167 - 72
Synthesis and antimicrobial activity of new 6-phenylimidazo{2,1-b}thiazole derivatives; Ulusoy N et al.; A series of new N2-substituted-6-phenylimidazo{2,1-b}thiazole-3-acetic acid hydrazides (2a-j) were synthesized and evaluated for in vitro antimicrobial activity against various bacteria and fungi . Some of the compounds showed antimicrobial activity against Staphylococcus aureus ATCC 6538, Staphylococcus epidermidis ATCC 12228, Trichophyton mentagrophytes var . Erinacei NCPF-375, Trichophyton rubrum and Microsporum audounii (MIC 25-0.24 micrograms/ml) . The in vitro antimycobacterial activity of the new compounds was also investigated . The compounds exhibited different degrees of inhibition (17.98%) against Mycobacterium tuberculosis H37Rv in the primary screen that was conducted at 12.5 micrograms/ml using the BACTEC 460 radiometric system.

Am J Health Syst Pharm, 2000 Oct 15, 57 Suppl 2, S10 - 2
Economic justification of antimicrobial management programs: implications of antimicrobial resistance; Paladino JA; The relationship between the problem of antimicrobial resistance and efforts to control antimicrobial costs is explored . Antimicrobial drug management typically centers around controlling costs and controlling antimicrobial resistance . Selection of therapeutic alternatives without adherence to a well-developed program or without a rationale based on data from the medical literature may promote antimicrobial resistance . Attempts to select alternatives can produce cost shifting rather than cost containment . The annual cost associated with antimicrobial resistance in the United States is estimated to be as high as $47 billion . In one study, patients with bacteremia caused by methicillin-resistant Staphylococcus aureus had an average length of stay 2.7 days longer than patients with susceptible strains and a mean cost of care that was $3500 higher . Infection control is one of the most important duties of health care practitioners . Given today's prevailing reimbursement structure, hospitals with high rates of nosocomial and resistant infections are likely to lose money . A basic problem with the current approach to controlling resistance is that the two most common strategies, highly restrictive formularies and drug cycling, work in opposition . Antimicrobial management programs should be directed at ensuring the most appropriate use of antimicrobials rather than focusing on limiting choices.

Am J Health Syst Pharm, 2000 Oct 15, 57 Suppl 2, S4 - 9
Area under the inhibitory curve and a pneumonia scoring system for predicting outcomes of vancomycin therapy for respiratory infections by Staphylococcus aureus; Moise PA et al.; Treatment factors predictive of clinical and microbiological outcomes and the relationship between a pneumonia scoring system and clinical outcomes in vancomycin-treated patients with a Staphylococcus aureus-associated lower-respiratory-tract infection (LRTI) were studied . A computer database review identified patients for whom S . aureus was isolated from a respiratory-tract specimen between January 1 and December 31, 1998, and who had antimicrobials ordered within 72 hours of isolation of that organism . Through further review of individual patient charts, this group was restricted to those treated with vancomycin for a documented S . aureus-associated LRTI . Classification-and-regression-tree (CART) modeling was performed to determine which clinical variables were correlated with clinical outcomes and microbiological outcomes . Median changes in clinical pneumonia scores from baseline in two patient groups (those with clinical success and those with clinical failure) were compared . Seventy patients met the study criteria . CART modeling found that both outcomes were associated with area under the inhibitory curve (AUIC) . The pneumonia scoring system was predictive of eventual clinical success as early as day 3 of treatment; having at least a 4-point decrease in the pneumonia score by day 3 was correlated with an 87% clinical success rate . Both AUIC and a pneumonia scoring system were useful for predicting clinical and microbiological outcomes of vancomycin therapy in patients with LRTIs caused by S . aureus.

Appl Environ Microbiol, 2000 Nov, 66(11), 4890 - 6
Use of hydrostatic pressure for inactivation of microbial contaminants in cheese; O'Reilly CE et al.; The objective of this study was to determine the effect of high pressure (HP) on the inactivation of microbial contaminants in Cheddar cheese (Escherichia coli K-12, Staphylococcus aureus ATCC 6538, and Penicillium roqueforti IMI 297987) . Initially, cheese slurries inoculated with E . coli, S . aureus, and P . roqueforti were used as a convenient means to define the effects of a range of pressures and temperatures on the viability of these microorganisms . Cheese slurries were subjected to pressures of 50 to 800 MPa for 20 min at temperatures of 10, 20, and 30 degrees C . At 400 MPa, the viability of P . roqueforti in cheese slurry decreased by >2-log-unit cycles at 10 degrees C and by 6-log-unit cycles at temperatures of 20 and 30 degrees C . S . aureus and E . coli were not detected after HP treatments in cheese slurry of >600 MPa at 20 degrees C and >400 MPa at 30 degrees C, respectively . In addition to cell death, the presence of sublethally injured cells in HP-treated slurries was demonstrated by differential plating using nonselective agar incorporating salt or glucose . Kinetic experiments of HP inactivation demonstrated that increasing the pressure from 300 to 400 MPa resulted in a higher degree of inactivation than increasing the pressurization time from 0 to 60 min, indicating a greater antimicrobial impact of pressure . Selected conditions were subsequently tested on Cheddar cheese by adding the isolates to cheese milk and pressure treating the resultant cheeses at 100 to 500 MPa for 20 min at 20 degrees C . The relative sensitivities of the isolates to HP in Cheddar cheese were similar to those observed in the cheese slurry, i.e., P . roqueforti was more sensitive than E . coli, which was more sensitive than S . aureus . The organisms were more sensitive to pressure in cheese than slurry, especially with E . coli . On comparison of the sensitivities of the microorganisms in a pH 5.3 phosphate buffer, cheese slurry, and Cheddar cheese, greatest sensitivity to HP was shown in the pH 5.3 phosphate buffer by S . aureus and P . roqueforti while greatest sensitivity to HP by E . coli was exhibited in Cheddar cheese . Therefore, the medium in which the microorganisms are treated is an important determinant of the level of inactivation observed.

Scand J Infect Dis, 2000, 32(5), 562 - 3
Brain abscess caused by methicillin-resistant Staphylococcus aureus; Ahlm C et al.; A Swedish tourist was admitted to a Cuban hospital due to epileptic seizures caused by brain tumors . Upon return to Sweden and admission to our hospital, methicillin-resistant Staphylococcus aureus (MRSA) was isolated . He was later considered to be free of MRSA but then developed a brain abscess from which MRSA was isolated.

Bioorg Med Chem Lett, 2000 Oct 16, 10(20), 2263 - 6
Analogues of SB-203207 as inhibitors of tRNA synthetases; Banwell MG et al.; SB-203207 and 10 analogues have been prepared, by elaboration of altemicidin, and evaluated as inhibitors of isoleucyl, leucyl and valyl tRNA synthetases (IRS, LRS, and VRS, respectively) . Substituting the isoleucine residue of SB-203207 with leucine and valine increased the potency of inhibition of LRS and VRS, respectively . The leucine derivative showed low level antibacterial activity, while several of the compounds inhibited IRS from Staphylococcus aureus WCUH29 more strongly than rat liver IRS.

Phytother Res, 2000 Nov, 14(7), 575 - 7
Cytotoxicity and antibacterial activity of ethanol extract from leaves of a herbal drug, boneset (Eupatorium perfoliatum); Habtemariam S et al.; The cytotoxic and antibacterial activity of an ethanol extract of leaves of a herbal drug, boneset (Eupatorium perfoliatum), was investigated . The extract showed potent cytotoxicity with EC(50) values (12-14 microg/mL) comparable to a standard cytotoxic agent, chlorambucil . The extract showed a weak antibacterial activity against gram-positive test organisms (Staphylococcus aureus and Bacillus megaterium) .

J Interferon Cytokine Res, 2000 Oct, 20(10), 907 - 13
Microspheres containing neutralizing antibodies to tumor necrosis factor-alpha and interleukin-1 beta protect rats from Staphylococcus aureus-induced peritonitis; D'Souza M et al.; Previous studies using microencapsulated neutralizing antibodies (NA) to tumor necrosis factor (TNF) and interleukin-1 (IL-1) in combination with gentamicin have demonstrated improved survival in a peritonitis model of gram-negative septic shock . Microencapsulation has been shown to improve the effectiveness of NA by delivering them intracellularly, taking advantage of the natural phagocytic activity of the macrophage . It is the purpose of this study to see if microencapsulated NA to TNF and IL-1 in combination with vancomycin can improve survival compared with NA in solution in Staphlococcus aureus-induced septic shock . Groups of 10 rats received the following treatments: (1) S . aureus plus no treatment, (2) S . aureus plus blank microspheres, (3) S . aureus plus vancomycin, (4) S . aureus plus a microsphere form of NA and vancomycin, (5) S . aureus plus a solution form of NA and vancomycin, (6) S . aureus plus a microsphere form of NA, and (7) S . aureus plus a solution form of NA . Survival was monitored for 5 days, and plasma TNF and IL-1 levels were measured for 48 h after S . aureus administration . All (100%) animals that received the microsphere form of NA plus vancomycin, 20%-70% of the animals that received the microsphere form of NA alone, and 20% of the animals that received antibiotics alone survived for 5 days or more . None of the animals in the no treatment group or blank microsphere treatment group and only 10% of the animals in the solution form of NA plus or minus vancomycin group survived for more than 5 days . Plasma TNF and IL-1 levels were significantly increased after S . aureus treatment . Simultaneous and delayed treatment with the microsphere form of NA plus or minus vancomycin significantly reduced TNF and IL-1 levels, and the solution form of NA significantly reduced only TNF levels after immediate treatment . The survival rate was higher in animals with lower TNF levels and IL-1 levels . The results demonstrate that the microsphere form of cytokine NA is 100% effective in combination with vancomycin in protecting rats from S . aureus-induced peritonitis . The microsphere form was also more efficient in attenuating both TNF and IL-1 levels.

Am J Physiol Gastrointest Liver Physiol, 2000 Nov, 279(5), G1094 - 103
Superantigen immune stimulation activates epithelial STAT-1 and PI 3-K: PI 3-K regulation of permeability; McKay DM et al.; Signal transducers and activators of transcription (STATs) are critical intracellular signaling molecules for many cytokines . We compared the ability of T84 epithelial cells to activate STATs in response to cytokines {interferon-gamma (IFN-gamma), interleukin (IL)-4, IL-10, and tumor necrosis factor-alpha (10 ng/ml)} and conditioned medium from superantigen {Staphylococcus aureus enterotoxin B (SEB)}-activated peripheral blood mononuclear cells (PBMC) using electrophoretic mobility shift assays (EMSA) . Of the cytokines tested, only IFN-gamma caused a STAT-1 response . Exposure to SEB-PBMC-conditioned medium resulted in STAT-1 or STAT-1/3 activation, and inclusion of anti-IFN-gamma antibodies in the conditioned medium abolished the STAT-1 signal . Cells treated with transcription factor decoys, DNA oligonucleotides bearing the STAT-1 recognition motif, and then SEB-PBMC-conditioned medium displayed a reduced STAT-1 signal on EMSA, yet this treatment did not prevent the drop in transepithelial resistance (measured in Ussing chambers) caused by SEB-PBMC-conditioned medium . In contrast, the phosphatidylinositol 3'-kinase (PI 3-K) inhibitor LY-294002 significantly reduced the drop in transepithelial resistance caused by SEB-PBMC-conditioned medium . Thus data are presented showing STAT-1 (+/-STAT-3) and PI 3-K activation in epithelial cells in response to immune mediators released by superantigen immune activation . Although the involvement of STAT-1/-3 in the control of barrier function remains a possibility, PI-3K has been identified as a regulator of T84 paracellular permeability.

J Spinal Disord, 2000 Oct, 13(5), 422 - 6
Postoperative spinal wound infection: a review of 2,391 consecutive index procedures; Weinstein MA et al.; Postoperative infection remains a troublesome but not uncommon complication after spinal surgery . Most previous reports, however, are small or involve cases with more than one surgeon often at different institutions . This study represents a single surgeon's 9-year experience with postoperative infection at one institution . The authors describe the features of wound infection after spinal surgery with reference to diagnosis, microbiology, and treatment and they describe a protocol for effective management of postoperative spinal wound infection . The records of the senior author (F.P.C.) during a 9-year period for cases of postoperative wound infection were reviewed . Of 2,391 operative procedures, 46 cases of wound infection were identified, yielding an overall infection rate of 1.9% . Patients' preoperative risk factors, original diagnosis prompting the surgery, onset of infection, presentation, treatment, and outcome were analyzed . The mean age of the 23 men and 23 women was 57.2 years . The preoperative diagnoses included lumbar degenerative scoliosis or spinal stenosis in 28 cases, disk prolapse in 8 cases, metastatic disease in 4 cases, degenerative disk disease in 1 case, and a group of 5 miscellaneous cases . Seventeen (37%) of the patients underwent at least one previous spinal surgery at the same site . Twenty-three patients had a fusion, of whom 22 also had instrumentation . Forty-three (93%) of the patients had significant wound drainage after an average of 15 days (range, 5-80 days) . The other three patients were examined approximately 2 years after the surgery . Fourteen of the patients also had pyrexia (temperature >37.5 degrees C) at presentation . Staphylococcus aureus alone was cultured in 29 patients, whereas another six patients had a different single organism . In nine patients, more than one organism was cultured during their hospital stay . Surgical treatment included primary closure in only seven patients, with most undergoing wound drainage and debridement followed by delayed closure . Instruments were removed in the three patients with late presentation who had solid fusion at operation . Viable bone graft and instrumentation were left in situ in all patients who were seen before fusion . All wounds healed without sequelae, except for three that required flap closure . Pseudarthrosis was noted in three patients after more than 1 year of follow-up in this series . Postoperative spinal wound infection is a potentially devastating problem . In this series, infection was more common in patients undergoing fusion with instrumentation and in patients with cancer metastatic to the spine . An aggressive surgical approach, including repeated debridement followed by delayed closure, is justified . Instrumentation may be safely left in situ to provide stability for fusion.

J Hosp Infect, 2000 Oct, 46(2), 123 - 9
Control of a methicillin-resistant Staphylococcus aureus outbreak in a neonatal intensive care unit by unselective use of nasal mupirocin ointment; Hitomi S et al.; In September 1996, an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) colonization occurred in the neonatal intensive care unit (NICU) of our hospital . After failing to control the outbreak by conventional methods we implemented an intranasal blanket use programme of mupirocin ointment from the beginning of November 1997 . In the programme, patients who had been carrying MRSA received intranasal administration of the ointment three times daily for the first three days and consecutively three times weekly, while newly admitted patients and those who had not been colonized were prophylactically medicated three times weekly . This blanket administration was executed for one month . Methicillin-resistant Staphylococcus aureus colonization became undetectable in all but one intubated inpatient who had already been colonized before the start of the programme, and no new acquisitions occurred until the middle of January 1998, seven weeks after the termination of the blanket use programme . The rate of colonized patients in the unit also decreased . During and after the programme, neither an increase in minimum inhibitory concentration for the antibiotic nor apparent adverse reactions in any of the treated patients were observed . We concluded that this procedure is an effective method of controlling an MRSA outbreak in an NICU when the outbreak cannot be managed with conventional measures .

J Hosp Infect, 2000 Oct, 46(2), 118 - 22
Effects on nursing workload of different methicillin-resistant Staphylococcus aureus (MRSA) control strategies; Farrington M et al.; Nursing staff workload may influence hospital-acquired staphylococcal transmission . Closure of wards to new admissions is used in some institutions as part of methicillin-resistant Staphylococcus aureus (MRSA) outbreak control, and we postulated that it worked by reducing staff workload, allowing more time for good infection control practices . We have used the GRASPCopyright workload system to compare nursing workload during six MRSA outbreaks . Two outbreaks occurred while an aggressive control policy ('old'; 1994-1995) was in place, with a low threshold for ward closure . Control measures had been relaxed before the later four outbreaks, with wards remaining fully or partially open unless MRSA transmission proved intractable ('new'; 1995-1996) . To standardize the analysis we compared GRASP and epidemiological data for periods while MRSA transmission was occurring on each ward ('during'), and four week periods 'before' and 'after' . Closing wards to admissions reduces staff workload towards a quality environment, although the nursing requirements of remaining patient rises . Workload pressures may rise during outbreaks if wards are not closed quickly and fully, and patients are not transferred to specialist isolation facilities . Changes in nursing workload need to be assessed during comparative studies of outbreak control measures and the GRASP(c) system appears to be a sensitive way to measure these .

J Dairy Sci, 2000 Oct, 83(10), 2269 - 75
Influence of bispecific antibodies on the in vitro bactericidal activity of bovine neutrophils against Staphylococcus aureus; Tomita GM et al.; We conducted the following study to determine if bispecific antibodies enhance the bactericidal activity of bovine neutrophils . Bispecific antibodies were synthesized by chemically crosslinking bovine neutrophil monoclonal antibodies to Staphylococcus aureus 305 capsule polysaccharide monoclonal antibodies . The efficiency of chemically coupling monoclonal antibody monomers was approximately 50% for each bispecific antibody produced . Monoclonal antibodies against neutrophils enhanced the respiratory burst activity of neutrophils by 2.3- to 2.5-fold . To determine the influence of bispecific antibodies on neutrophil function, S . aureus 305 was preincubated with various concentrations of bispecific antibodies and neutrophils were then added to the opsonized bacteria at different bacteria to neutrophil ratios . The bactericidal activity of neutrophils was expressed as a percentage reduction in colony-forming units in test cultures compared with the number of colony-forming units in control test cultures that did not contain bispecific antibodies or neutrophils . The addition of bispecific antibodies to test cultures increased the bactericidal activity of neutrophils . A reduction in colony-forming units as a function of increasing the S . aureus 305 to neutrophils ratio was observed in both the absence and presence of bispecific antibodies . However, a greater reduction was observed in the presence of bispecific antibodies . Increasing concentrations of bispecific antibodies enhanced the bactericidal activity of neutrophils at a constant S . aureus 305 to neutrophil ratio of 1:500 . The results indicate that bispecific antibodies that recognize both S . aureus 305 capsular polysaccharide and neutrophil antigens potentiate the bactericidal activity of neutrophils.

J AOAC Int, 2000 Sep-Oct, 83(5), 1096 - 107
Evaluation of a dry, rehydratable film method for rapid enumeration of Staphylococcus aureus; Mach PA et al.; Results with the new 3M Petrifilm Rapid S . aureus Count (RSA) Plate method were compared with those of the classical Baird-Parker agar (BPA) method for detection and enumeration of Staphylococcus aureus . Studies on 219 bacterial strains demonstrated that the Petrifilm RSA plate is more sensitive than and as specific as the classical BPA method for confirmed identification of S . aureus . Counts of colonies from 71 pure cultures, 61 naturally contaminated food samples, and more than 750 artificially inoculated food samples showed that the Petrifilm RSA method was as effective as the classical BPA method for identification and enumeration of S . aureus . The Petrifilm RSA method gave results in one-third the time required for the classical method.

J Vet Med B Infect Dis Vet Public Health, 2000 Sep, 47(7), 517 - 26
The ability of the enzyme-linked immunosorbent assay to detect antibody against Staphylococcus aureus in milk following experimental intramammary infection; Fox LK et al.; Changes in the milk antibody levels against Staphylococcus aureus were measured at the start of an experimental intramammary instillation of either S . aureus (Study I) or Staphylococcus hyicus (Study II) . A commercial enzyme-linked immunosorbent assay system was used . Twenty-one Holstein cows were enrolled in Study I and 15 Holstein cows were used in Study II . Pathogen instillation began 21 days before the start of the non-lactating period . Cows received intramammary antibiotic treatment in all quarters immediately after the last milking, the start of the non-lactating period . Lacteal secretions were collected before the start of the non-lactating period, and during the immediate postpartum period in both studies, and during the non-lactating period in Study I . Milk was cultured for mastitis pathogens and S . aureus antibody levels and somatic cell counts were determined from all samples . There was an approximate 2-week delay in the elevation in antibody levels in response to the instillation of S . aureus . Antibody levels remained elevated in cows with S . aureus intramammary infections postpartum, but were below threshold in cows where intramammary infections were cured during the non-lactating period . Antibody levels were elevated by S . hyicus intramammary infections, remained elevated for the first 12 days postpartum, but were below threshold by day 21 postpartum . Cows with incipient intramammary S . aureus infections might be misclassified as false negatives by the antibody test . However, results suggest that cows with S . hyicus intramammary infections that were not cured would not be misclassified if milk is withheld from test for the first 30 days postpartum, as recommended by the manufacturer of the test.

Adv Perit Dial, 2000, 16, 324 - 7
Nasal carriage of Staphylococcus aureus in families of children on peritoneal dialysis . European Pediatric Peritoneal Dialysis Study Group (EPPS); Oh J et al.; Nasal carriage of Staphylococcus aureus is a risk factor for catheter-related infections with S . aureus in patients on chronic peritoneal dialysis (CPD) . In children, S . aureus may transmitted to the catheter either from the patients' nares, or from the nares of caregiving carriers . As part of a prospective trial on the efficacy of mupirocin prophylaxis in children on CPD and their caregivers, we evaluated the prevalence of S . aureus carriage in 92 families of pediatric CPD patients . Patients and their caregivers (usually both parents) were screened by three nasal cultures obtained within four weeks . In 62% of the families, neither the patients nor any caregiver carried S . aureus . In 23%, the patient or at least one caregiver (sometimes both) was identified as a carrier . In 15%, at least one caregiver, but not the patient, was colonized with S . aureus . During further follow-up by once-monthly nasal cultures, 5 of the 57 initially negative patients developed S . aureus colonization, and in two families, at least one caregiver turned positive . Including these "occasional" carriers, the cumulative likelihood of one or several family members carrying S . aureus gradually increased to a plateau of about 55% after 6 observation months . Susceptibility rates of cultured S . aureus were 100% for vancomycin, 99% for aminoglycosides, 95% for piperacillin/tazobactam, 94% for cephalosporins, and 15% for ampicillin . In two patients and two caregivers (four different families), methicillin-resistant S . aureus was found . Three isolates from three different families were resistant to mupirocin . We conclude that S . aureus colonization is common in families of children on CPD . While 85% of carrier families are detected by 3 sequential nose cultures in patient and caregivers, up to 9 cultures may be required in "occasional" carriers.

Adv Perit Dial, 2000, 16, 271 - 5
Outcome and clinical implications of a surveillance and treatment program for Staphylococcus aureus nasal carriage in peritoneal dialysis patients; Crabtree JH et al.; Staphylococcus aureus nasal carriage (SANC) is a risk factor for development of S . aureus dialysis-related infections . Reported here are results of a SANC surveillance and treatment program employed by our dialysis unit over a two-year period . Surveillance nasal cultures were performed at 3-month intervals in 129 peritoneal dialysis patients . Those with SANC applied mupirocin ointment intranasally 3 times daily for 5 consecutive days for 3 consecutive months . Treatment was repeated only when subsequent cultures showed SANC . Infection and catheter loss rates were compared to 63 historical controls, and between SANC and non SANC patients of the study group . Patients who were initially non carriers showed increasing probability for acquiring SANC throughout the study period . Following treatment, the probability for recurrence of SANC was 26%, 41%, 58%, and 62% at 1, 3, 6, and 12 months . The rates of S . aureus exit-site or tunnel infection (p = 0.36), peritonitis (p = 0.0002), and catheter loss (p = 0.01) were lower in the study group as compared to controls . Despite treatment, SANC patients demonstrated a twofold increase in exit-site/tunnel infection rate (p = 0.03) and a threefold increase in catheter loss rate (p = 0.1) as compared to non SANC patients . The high rate of SANC recurrence and the long interval between surveillance cultures may explain the failure of the current protocol to completely eliminate the risk for S . aureus infections . The results support a change in the treatment plan to that of continuing the monthly mupirocin regimen indefinitely once SANC has been identified.

Adv Perit Dial, 2000, 16, 257 - 61
The effectiveness of mupirocin preventing Staphylococcus aureus in catheter-related infections in peritoneal dialysis; Thodis E et al.; The objective of this study was to evaluate the effectiveness of mupirocin on Staphylococcus aureus with regard to peritoneal dialysis (PD)-catheter exit-site infections (ESI), tunnel infections (TI), and peritonitis episodes (PE) . The study was performed on 42 continuous ambulatory peritoneal dialysis (CAPD) patients (group I) treated from April 1998 to July 1999 . These patients were instructed to apply mupirocin daily at the catheter exit site as part of their exit-site care . The control was the same group's historical infection data . Results were also recorded for a second group of 16 patients (group II) with newly implanted PD catheters were also instructed to apply mupirocin at the exit site daily . During the control period (before daily mupirocin application), group I recorded 16 episodes of ESI (0.30 episodes per patient-year), 6 episodes of TI (0.11 episodes per patient-year), 15 episodes of PE (0.28 episodes per patient-year), and one case of catheter removal (0.019 episodes per patient-year) owing to S . aureus exit-site infection coexisting with peritonitis . The rate of S . aureus exit-site infection during this period was 0.11 episodes per patient-year; of S . aureus tunnel infection, 0.057 episodes per patient-year; and of S . aureus peritonitis, 0.076 episodes per patient-year . During the mupirocin period, infections and peritonitis owing to S . aureus dramatically decreased (p < 0.01 and p < 0.001 respectively) . The rate of S . aureus exit-site infection was 0.02 episodes per patient-year, with no S . aureus tunnel infections, and no catheter removals owing to S . aureus peritonitis . Similarly, in group II, no episodes were recorded of any ESI, TI, or PE owing to S . aureus, although 4 episodes of ESI (0.37 episodes per patient-year, 2 with other gram-positive bacteria, and 2 with gram-negative bacteria) and 8 PEs (0.75 episodes per patient-year) were seen . We conclude that mupirocin application provides excellent prophylaxis for catheter-related infections owing to S . aureus, and that reduction of these infections may improve the long-term survival of patients on CAPD.

Adv Perit Dial, 2000, 16, 248 - 51
Clonotypes of Staphylococcus aureus isolated from continuous ambulatory peritoneal dialysis patients: what is the vector between nares and infection site?
Nakamura M, Watanabe Y, Osono E, Ohwada K, Kurihara S, Toume K, Yoneshima H, Ohkuni H.
Staphylococcus aureus is frequently isolated from patients with infections related to continuous ambulatory peritoneal dialysis (CAPD) . In many cases, the organism is also isolated simultaneously from the anterior nares . To clarify the transmission trail of S . aureus, we used DNA analysis to identify clonotypes of clinical strains . The nares and exit sites of 32 CAPD patients were swabbed, and PD fluid samples were taken for pathogen culture . Genome DNA of S . aureus was digested with restriction enzyme Sma I for pulsed-field gel electrophoresis . We also asked the patients how they usually performed the PD procedure . S . aureus was isolated from 4 patients, including 3 who hosted two strains isolated separately from different sites . The DNA patterns of the strains isolated from these latter 3 patients were identical . However, the clonotypes from all 4 patients were different . Most of the patients did not wash their hands and wear masks while exchanging PD bags and caring for their exit sites . After the patients were disinfected and re-educated in proper procedures, S . aureus was not detected in any of them . These data suggest that no outbreak occurred in our hospital and that the vectors of endogenous infection were the patients themselves, probably their hands . A bacteriological study presents an efficient opportunity to re-educate patients in PD procedure.

J Biol Chem, 2001 Jan 26, 276(4), 2466 - 73 Epub 2000 Oct 23.
Identification of residues in the Staphylococcus aureus fibrinogen-binding MSCRAMM clumping factor A (ClfA) that are important for ligand binding; Hartford OM et al.; Clumping factor A (ClfA) is a cell surface-associated protein of Staphylococcus aureus that promotes binding of this pathogen to both soluble and immobilized fibrinogen (Fg) . Previous studies have localized the Fg-binding activity of ClfA to residues 221-559 within the A region of this protein . In addition, the C-terminal part of the A region (residues 484-550) has been implicated as being important for Fg binding . In this study, we further investigate the involvement of this part of ClfA in the interaction of this protein with Fg . Polyclonal antibodies generated against a recombinant protein encompassing residues 500-559 of the A region inhibited the interaction of both S . aureus and recombinant ClfA with immobilized Fg in a dose-dependent manner . Using site-directed mutagenesis, two adjacent residues, Glu(526) and Val(527), were identified as being important for the activity of ClfA . S . aureus expressing ClfA containing either the E526A or V527S substitution exhibited a reduced ability to bind to soluble Fg and to adhere to immobilized Fg . Furthermore, bacteria expressing ClfA containing both substitutions were almost completely defective in Fg binding . The E526A and V527S substitutions were also introduced into recombinant ClfA (rClfA-(221-559)) expressed in Escherichia coli . The single mutant rClfA-(221-559) proteins showed a significant reduction in affinity for both immobilized Fg and a synthetic fluorescein-labeled C-terminal gamma-chain peptide compared with the wild-type protein, whereas the double mutant rClfA-(221-559) protein was almost completely defective in binding to either species . Substitution of Glu(526) and/or Val(527) did not appear to alter the secondary structure of rClfA-(221-559) as determined by far-UV circular dichroism spectroscopy . These data suggest that the C terminus of the A region may contain at least part of the Fg-binding site of ClfA and that Glu(526) and Val(527) may be involved in ligand recognition.

Cytometry, 2000 Nov 1, 41(3), 203 - 8
Rapid DNA fingerprinting of pathogens by flow cytometry; Larson EJ et al.; BACKGROUND: A new method for rapid discrimination among bacterial strains based on DNA fragment sizing by flow cytometry is presented . This revolutionary approach combines the reproducibility and reliability of restriction fragment length polymorphism (RFLP) analysis with the speed and sensitivity of flow cytometry . METHODS: Bacterial genomic DNA was isolated and digested with a rare-cutting restriction endonuclease . The resulting fragments were stained stoichiometrically with PicoGreen dye and introduced into an ultrasensitive flow cytometer . A histogram of burst sizes from the restriction fragments (linearly related to fragment length in base pairs) resulted in a DNA fingerprint that was used to distinguish among different bacterial strains . RESULTS: Five different strains of gram-negative Escherichia coli and six different strains of gram-positive Staphylococcus aureus were distinguished by analyzing their restriction fragments with DNA fragment sizing by flow cytometry . Fragment distribution analyses of extracted DNA were approximately 100 times faster and approximately 200,000 times more sensitive than pulsed-field gel electrophoresis (PFGE) . When sample preparation time is included, the total DNA fragment analysis time was approximately 8 h by flow cytometry and approximately 24 h by PFGE . CONCLUSIONS: DNA fragment sizing by flow cytometry is a fast and reliable technique that can be applied to the discrimination among species and strains of human pathogens . Unlike some polymerase chain reaction (PCR)-based methods, sequence information about the bacterial strains is not required, allowing the detection of unknown, newly emerged, or unanticipated strains.

Biochim Biophys Acta, 2000 Oct 18, 1523(2-3), 135 - 9
Inactivation of a novel three-cistronic operon tcaR-tcaA-tcaB increases teicoplanin resistance in Staphylococcus aureus; Brandenberger M et al.; A novel teicoplanin-associated operon termed tcaR-tcaA-tcaB was identified by Tn917-mediated insertional mutagenesis . Resistance to teicoplanin rose 4-fold by insertional inactivation of tcaA or by deletion of the entire operon . tcaA encodes a hypothetical transmembrane protein with a metal-binding motif, possibly a sensor-transducer . tcaB codes for a membrane-associated protein, which has sequence homologies to a bicyclomycin resistance protein . The two genes are preceded by tcaR encoding a putative regulator with sequence homologies to the transcriptional regulator MarR . The fact that tcaA inactivation as well as deletion of tcaRAB produced the same increase in teicoplanin resistance confirmed the association of tcaRAB with teicoplanin susceptibility . Cotransductional crosses showed that the level of teicoplanin resistance produced by these insertions was strain-dependent and that in the methicillin-resistant strain COL, it was paired with a remarkable decrease in methicillin resistance . This allowed to postulate that tcaRAB may be involved in some way in cell wall biosynthesis, and that teicoplanin may interact with TcaA and/or TcaB either directly or indirectly.

J Immunol Methods, 2000 Nov 1, 245(1-2), 79 - 89
Effect of IFN-gamma on the killing of S . aureus in human whole blood . Assessment of bacterial viability by CFU determination and by a new method using alamarBlue; DeForge LE et al.; Given the increasing incidence of methicillin resistant Staphylococcus aureus (MRSA) and the recent emergence of MRSA with a reduced susceptibility to vancomycin, alternative approaches to the treatment of infection are of increasing relevance . The purpose of these studies was to evaluate the effect of IFN-gamma on the ability of white blood cells to kill S . aureus and to develop a simpler, higher throughput bacterial killing assay . Using a methicillin sensitive clinical isolate of S . aureus, a clinical isolate of MRSA, and a commercially available strain of MRSA, studies were conducted using a killing assay in which the bacteria were added directly into whole blood . The viability of the bacteria in samples harvested at various time points was then evaluated both by the classic CFU assay and by a new assay using alamarBlue . In the latter method, serially diluted samples and a standard curve containing known concentrations of bacteria were placed on 96-well plates, and alamarBlue was added . Fluorescence readings were taken, and the viability of the bacteria in the samples was calculated using the standard curve . The results of these studies demonstrated that the CFU and alamarBlue methods yielded equivalent detection of bacteria diluted in buffer . For samples incubated in whole blood, however, the alamarBlue method tended to yield lower viabilities than the CFU method due to the emergence of a slower growing subpopulation of S . aureus upon incubation in the blood matrix . A significant increase in bacterial killing was observed upon pretreatment of whole blood for 24 h with 5 or 25 ng/ml IFN-gamma . This increase in killing was detected equivalently by the CFU and alamarBlue methods . In summary, these studies describe a method that allows for the higher throughput analysis of the effects of immunomodulators on bacterial killing.

FEBS Lett, 2000 Oct 20, 483(2-3), 135 - 8
Induction of synthesis of an antimicrobial peptide in the skin of the freeze-tolerant frog, Rana sylvatica, in response to environmental stimuli; Matutte B et al.; An extract of skin taken from specimens of the freeze-tolerant wood frog, Rana sylvatica, that were collected from cold (<7 degrees C) ponds and maintained at 5 degrees C lacked detectable antimicrobial activity . In contrast, an extract of skin taken from specimens maintained at 30 degrees C for 3 weeks under laboratory conditions contained a high concentration (approximately 4 nmol/g) of a single antimicrobial peptide of the brevinin-1 family (FLPVVAGLAAKVLPSIICAVTKKC) . The peptide inhibited growth of Escherichia coli (minimum inhibitory concentration 45 microM) and Staphylococcus aureus (minimum inhibitory concentration 7 microM) . The data suggest that synthesis of the peptide is induced when the animal is in an environment that promotes the growth of microorganisms consistent with a role in the animal's defense strategy.

J Infect, 2000 Jul, 41(1), 97 - 100
Aspergillus vertebral osteomyelitis in a child with a primary monocyte killing defect: response to GM-CSF therapy; Abu Jawdeh L et al.; We report the first case of vertebral aspergillosis in a child with a primary defect in monocyte killing, an extremely rare immunodeficiency The diagnosis of defective monocyte killing was made by an in vitro assay that showed normal killing of Staphylococcus aureus by the patient's neutrophils but impaired killing by his monocytes . Importantly, the extensive granulomatous infection that involved the vertebral column, posterior mediastinum, pleura, and lung was not responsive to aggressive treatment with a combination of liposomal amphotericin B . intralesional amphotericin B . itraconazole, and granulocyte transfusions . Dramatic clinical and radiological improvement was only seen after the addition of granulocyte macrophage-colony stimulating factor (GM-CSF) to his treatment regimen . The use of GM-CSF in the treatment of invasive aspergillosis in immunocompromised patients requires further evaluation.

Can J Vet Res, 2000 Oct, 64(4), 232 - 7
Longitudinal evaluation of CD4+ and CD8+ peripheral blood and mammary gland lymphocytes in cows experimentally inoculated with Staphylococcus aureus; Rivas AL et al.; Staphylococcus aureus is a major pathogen associated with mastitis, a disease affecting both women and dairy cows . The longitudinal profiles of bovine peripheral blood and mammary gland lymphocyte phenotypes in response to S . aureus-induced mastitis were investigated in dairy cows . Increased percentage of CD4 lymphocytes in the mammary gland between 1 and 8 days post-inoculation, increased milk CD4 protein density per cell between 1-8 days post-inoculation, and a statistically significant negative correlation between post-inoculation bacterial counts in milk and blood lymphocyte CD4 protein density were found . Together with blood and milk leukocyte counts, the milk lymphocyte CD4/CD8 ratio and the milk lymphocyte CD4 protein density were more informative indicators than milk somatic cell counts and bacteriology for identification of early vs . late inflammatory phases . These findings suggest that CD4+ lymphocytes play a protective role in the early stages of S . aureus-induced mastitis.

J Heart Valve Dis, 2000 Sep, 9(5), 697 - 704
Aortic valve replacement for endocarditis: determinants of early and late outcome; Langley SM et al.; BACKGROUND AND AIM OF THE STUDY: The study aim was to determine risk factors for operative mortality, recurrent infection, reoperation and long-term survival following aortic valve replacement (AVR) for infective endocarditis . METHODS: Between 1973 and 1997, 109 patients (91 male, 18 female, mean age 52.6 years) underwent isolated AVR for infective endocarditis in our unit . Native valve endocarditis was present in 89 (81.6%) and prosthetic valve endocarditis in 20 (18.4%) . Active culture-positive endocarditis was present in 53 (48.6%) . Preoperatively, 99 patients (90.8%) were in NYHA classes III and IV . Indications for surgery included cardiac failure in 41 patients, valvular dysfunction in 38, vegetations in 18, sepsis in seven, abscess in six and embolism in four . Mechanical valves were implanted in 69 patients (63.3%) and bioprostheses in 40 (36.7%), including a homograft in 19 (17.4%) . Follow up was complete (mean 5.8 years; range: 0-23.8 years; total 633.5 patient-years) . RESULTS: The operative mortality was 10.1% (11 deaths) . At ten years, freedom from recurrent infection was 94.2%, and freedom from reoperation 83.6% . Biological valve and younger age were significant adverse parameters for freedom from reoperation (p = 0.01 and p = 0.01) . There have been 21 late deaths, 15 due to cardiac causes . Kaplan-Meier survival, including operative mortality, at five and ten years was 77.4% and 68.0%, respectively . On Cox proportional hazards regression, Staphylococcus aureus infection (p = 0.008) and older age (p = 0.04) were independent adverse predictors of survival . CONCLUSION: AVR for endocarditis carries a relatively high operative mortality, but can result in a satisfactory freedom from recurrent infection, reoperation and long-term survival . Analysis of our series demonstrates that implantation of a biological valve limits the freedom from reoperation and that infection by Staph . aureus reduces the probability of long-term survival.

Fukushima J Med Sci, 1999 Dec, 45(2), 125 - 33
Rhabdomyolysis and aggravation of arthritis in a rheumatoid arthritis patient as a result of sepsis due to Staphylococcus aureus infection of a rheumatoid nodule; a catastrophic outcome; Saito H et al.; A 63-year-old man with rheumatoid arthritis presented with rhabdomyolysis and intractable arthritis of acute onset . He was diagnosed to have sepsis due to Staphylococcus aureus infection through of an ulcerated rheumatoid nodule . Staphylococcus aureus isolated from pus in the ulcerated rheumatoid nodule and a blood sample obtained from the heart post-mortem produced the toxic shock syndrome toxin-1 (TSST-1) . The TSST-1 and/or unmethylated CpG motifs in the oligonucleotides present in a bacterium, Staphylococcus aureus in this case, might be implicated in the induction of rhabdomyolysis and intractable arthritis.

Laryngoscope, 2000 Oct, 110(10 Pt 1), 1702 - 6
Value of antral puncture in the intensive care patient with fever of unknown origin; Vandenbussche T et al.; OBJECTIVE: To evaluate the use of maxillary sinus puncture as a routine diagnostic procedure to exclude or confirm purulent sinusitis in intensive care unit (ICU) patients presenting with fever or a septic state of unknown origin . STUDY DESIGN: Retrospective . METHODS: All patients admitted to the ICU at the University Hospital Ghent who required ENT examination to exclude acute sinusitis as possible cause of their otherwise inexplicable fever or septic state underwent maxillary sinus puncture via the inferior meatus . The results of clinical examination and the relation between the presence of foreign bodies (e.g., nasogastric tubes) and culture results from the middle meatus and sinuses were analyzed . RESULTS: One hundred five punctures were performed in 53 patients . Macroscopic purulent effusions were obtained from 25 and nonpurulent effusions from 19 sinuses . The presence of a nasogastric tube did not influence puncture results but significantly increased colonization of the middle meatus . Staphylococcus aureus and Gram-negative agents were frequently cultured from sinus aspirates . Although purulent secretions often reveal no growth, most patients present with a multibacterial (40%) or monobacterial (28%) infection . Simple anterior rhinoscopy reduces the need for antral puncture . Only 8% of punctures in patients with a normal clinical examination were positive . CONCLUSIONS: Antral puncture proves to be a simple, fast, safe, inexpensive, and effective procedure for immediate diagnosis of acute nosocomial sinusitis in ICU patients and is therefore recommended as first procedure in these patients, even when only minor clinical abnormalities are present.

Antimicrob Agents Chemother, 2000 Nov, 44(11), 3229 - 31
Development of resistance to ciprofloxacin, rifampin, and mupirocin in methicillin-susceptible and -resistant Staphylococcus aureus isolates; Schmitz FJ et al.; A relationship between resistance to methicillin and resistance to fluoroquinolones, rifampin, and mupirocin has been described for Staphylococcus aureus . Differences in resistance rates may be explainable by a higher spontaneous mutation rate (MR) or a faster development of resistance (DIFF) in methicillin-resistant S . aureus (MRSA) . No differences in MR, DIFF, and mutations in grlA and gyrA were detected between methicillin-susceptible S . aureus and MRSA . The higher resistance rates in MRSA are not the result of hypermutability of target genes or a faster emergence of different mutations and may be the consequence of clonal spread of multiresistant MRSA.

Antimicrob Agents Chemother, 2000 Nov, 44(11), 3206 - 9
Thrombin-induced platelet microbicidal protein susceptibility phenotype influences the outcome of oxacillin prophylaxis and therapy of experimental Staphylococcus aureus endocarditis; Dhawan VK et al.; We previously showed that in vitro susceptibility profiles of Staphylococcus aureus to thrombin-induced platelet microbicidal protein 1 (tPMP-1) impacted the outcome of vancomycin treatment in experimental infective endocarditis . In this same model, treatment with oxacillin (a more rapid staphylocidal agent than vancomycin) enhanced the clearance of both tPMP-1-susceptible and -resistant cells from vegetations . The extent of clearance was greater for tPMP-1-susceptible cells.

Antimicrob Agents Chemother, 2000 Nov, 44(11), 3193 - 5
Intracellular penetration and activity of gemifloxacin in human polymorphonuclear leukocytes; Garcia I et al.; The intracellular penetration and activity of gemifloxacin in human polymorphonuclear leukocytes (PMN) were evaluated . Gemifloxacin reached intracellular concentrations eight times higher than extracellular concentrations . The uptake was rapid, reversible, and nonsaturable and was affected by environmental temperature, cell viability, and membrane stimuli . At therapeutic extracellular concentrations, gemifloxacin showed intracellular activity against Staphylococcus aureus.

Antimicrob Agents Chemother, 2000 Nov, 44(11), 3163 - 6
RNA polymerase inhibitors with activity against rifampin-resistant mutants of Staphylococcus aureus; O'Neill A et al.; A collection of rifampin-resistant mutants of Staphylococcus aureus with characterized RNA polymerase beta-subunit (rpoB) gene mutations was cross-screened against a number of other RNA polymerase inhibitors to correlate susceptibility with specific rpoB genotypes . The rpoB mutants were cross-resistant to streptolydigin and sorangicin A . In contrast, thiolutin, holomycin, corallopyronin A, and ripostatin A retained activity against the rpoB mutants . The second group of inhibitors may be of interest as drug development candidates.

Antimicrob Agents Chemother, 2000 Nov, 44(11), 3055 - 60
In vitro synergistic effects of double and triple combinations of beta-lactams, vancomycin, and netilmicin against methicillin-resistant Staphylococcus aureus strains; Rochon-Edouard S et al.; Several studies have previously reported synergistic effects between vancomycin and a given beta-lactam or a given aminoglycoside against methicillin-resistant Staphylococcus aureus (MRSA) strains . The aim of our study was to exhaustively compare the effects of different combinations of a beta-lactam, vancomycin, and/or an aminoglycoside against 32 clinical MRSA strains with different aminoglycoside susceptibility patterns . The effects of 26 different beta-lactam-vancomycin and 8 different aminoglycoside-vancomycin combinations were first studied using a disk diffusion screening method . The best interactions with vancomycin were observed with either imipenem, cefazolin, or netilmicin . By checkerboard studies, imipenem-vancomycin and cefazolin-vancomycin each provided a synergistic bacteriostatic effect against 22 strains; the mean fractional inhibitory concentration (FIC) indexes were 0.35 and 0.46 for imipenem-vancomycin and cefazolin-vancomycin, respectively . The vancomycin-netilmicin combination provided an indifferent effect against all of the 32 strains tested; the mean of FIC index was 1 . 096 . The mean concentrations of imipenem, cefazolin, netilmicin, and vancomycin at which FIC indexes were calculated were clinically achievable . Killing experiments were then performed using imipenem, cefazolin, netilmicin, and vancomycin at one-half of the MIC, alone and in different combinations, against 10 strains . The vancomycin-netilmicin regimen was rarely bactericidal, even against strains susceptible to netilmicin . The imipenem-vancomycin and cefazolin-vancomycin combinations were strongly bactericidal against six and five strains, respectively . The addition of netilmicin markedly enhanced the killing activity of the combination of cefazolin or imipenem plus vancomycin, but only for the MRSA strains against which the beta-lactam-vancomycin combinations had no bactericidal effect . It is noteworthy that the latter strains were both susceptible to netilmicin and heterogeneously resistant to methicillin.

Antimicrob Agents Chemother, 2000 Nov, 44(11), 2991 - 8
Activities of LY333328 and vancomycin administered alone or in combination with gentamicin against three strains of vancomycin-intermediate Staphylococcus aureus in an in vitro pharmacodynamic infection model; Aeschlimann JR et al.; Staphylococcus aureus with intermediate glycopeptide susceptibility (glycopeptide-intermediate S . aureus {GISA}) has been isolated from patients with apparent therapy failures . We studied the killing activity of vancomycin over a range of simulated conventional doses (1 to 1.5 g every 12 h) against three of these GISA strains in an in vitro pharmacodynamic infection model . We also studied the activity of a new glycopeptide (LY333328) at a simulated dose of 3 mg/kg of body weight every 24 h or 5 mg/kg every 24 h, as well as the potential for vancomycin and gentamicin synergy against these GISA strains . Four doses of vancomycin with or without gentamicin or two doses of LY333328 were administered over the 48-h study period . The vancomycin and LY333328 MICs and minimal bactericidal concentrations (MBCs) for the three GISA strains (strains 14379, 992, and Mu50) were 8 and 8 microgram/ml and 1 and 2 microgram/ml, respectively, for GISA 14379, 6 and 6 microgram/ml and 1 and 1 microgram/ml, respectively, for GISA 992, and 8 and 12 microgram/ml and 2 and 8 microgram/ml, respectively, for GISA Mu50 . Vancomycin and LY333328 MICs and MBCs were 0.75 and 1.0 microgram/ml and 1 and 1 microgram/ml, respectively for a vancomycin-susceptible comparator strain (methicillin-resistant S . aureus {MRSA} 494) . The addition of albumin to the growth medium increased the LY333328 MICs and MBCs approximately 8- to 16-fold . Vancomycin was bacteriostatic against the three GISA strains at doses of 1, 1.125, and 1.25 g every 12 h . Vancomycin was bactericidal at the dose of 1.5 g every 12 h against all strains; bactericidal activity occurred against the GISA strains at 8- to 10-fold lower ratios of the peak concentration to the MIC and the area under the concentration-time curve from time zero to 24 h (AUC(0-24)) to the MIC compared to those for the vancomycin-sensitive control strain . Overall, vancomycin activity was significantly correlated with the AUC(0-24) (R(2) = 0.79; P < 0.001) by multiple stepwise regression analyses . The addition of gentamicin did not significantly affect killing activity against any strain . LY333328 was bactericidal against GISA strains 14379 and 992 and against MRSA 494 only with the 5-mg/kg/day dose simulations . The higher dose of LY333328 also prevented regrowth over the 48-h experiments for all strains tested . Higher doses of vancomycin (1.5 g every 12 h) and LY333328 (5 mg/kg every 24 h) may represent potential treatment options for infections caused by GISA strains.

J Immunol, 2000 Oct 15, 165(8), 4346 - 52
The expression of p18INK4 and p27kip1 cyclin-dependent kinase inhibitors is regulated differently during human B cell differentiation; Schrantz N et al.; Cell cycle progression is under the control of cyclin-dependent kinases (cdks), the activity of which is dependent on the expression of specific cdk inhibitors . In this paper we report that the two cdk inhibitors, p27(Kip1) and p18(INK4c), are differently expressed and control different steps of human B lymphocyte activation . Resting B cells contain large amounts of p27(Kip1) and no p18(INK4c) . In vitro stimulation by Staphylococcus aureus Cowan 1 strain or CD40 ligand associated with IL-10 and IL-2 induces a rapid decrease in p27(Kip1) expression combined with cell cycle entry and progression . In contrast, in vitro Ig production correlates with specific expression of p18(INK4c) and early G(1) arrest . This G(1) arrest is associated with inhibition of cyclin D3/cdk6-mediated retinoblastoma protein phosphorylation by p18(INK4c) . A similar contrasting pattern of p18(INK4c) and p27(Kip1) expression is observed both in B cells activated in vivo and in various leukemic cells . Expression of p18(INK4c) was also detected in various Ig-secreting cell lines in which both maximum Ig secretion and specific p18(INK4c) expression were observed during the G(1) phase . Our study shows that p27(Kip1) and p18(INK4c) have different roles in B cell activation; p27(Kip1) is involved in the control of cell cycle entry, and p18(INK4c) is involved in the subsequent early G(1) arrest necessary for terminal B lymphocyte differentiation.

FEMS Microbiol Lett, 2000 Sep 15, 190(2), 299 - 303
Novel arbekacin- and amikacin-modifying enzyme of methicillin-resistant Staphylococcus aureus; Fujimura S et al.; An aminoglycoside-modifying enzyme in arbekacin-resistant methicillin-resistant Staphylococcus aureus (MRSA), exhibiting 4'''-N-acetylation, was examined . Although the MRSA strain with AAC(4''') had no AAC(6')-APH(2") activity, a DNA fragment of the AAC(6')-APH(2") gene was amplified by PCR and the purified N-terminal 30-amino acid sequence of this AAC(4''') was identical to AAC(6')-APH(2") . Direct DNA sequencing of this 'silent' AAC(6')-APH(2") gene revealed a single point mutation leading to a substitution of Gly for Asp80, through which the secondary structure is affected . A change in protein conformation could lead to a cleavage and a change of the enzymatic activity . We propose a new aminoglycoside-resistance mediated by AAC(4''') is caused by a mutation-modified AAC(6')-APH(2").

J Biomed Mater Res, 2000 Dec 15, 52(4), 709 - 15
Prevention of infection with tobramycin-containing bone cement or systemic cefazolin in an animal model; Nijhof MW et al.; We investigated in an animal model the efficacy of tobramycin-containing bone cement and systemic cefazolin for infection prophylaxis . In 18 female rabbits, the femoral cavity was inoculated with Staphylococcus aureus before injection of bone cement . The first group of six rabbits received tobramycin-containing Simplex-P bone cement . Two other groups of six rabbits received plain Simplex-P bone cement . Preoperatively, in one of the two latter groups cefazolin was administered intravenously . The other group served as untreated controls . The rabbits were monitored for clinical signs of infection . At 7 days' follow-up, the femora were harvested and cultures from the bone adjacent to the cement plug were quantified . Cultures from the rabbits which received antibiotic prophylaxis (either cefazolin systemically or tobramycin-containing bone cement) were all negative . In contrast, all rabbits in the untreated control group had positive cultures . These rabbits also had other signs of infection such as an elevated erythrocyte sedimentation rate and loss of body weight . Culture results were confirmed by the absence of bacterial DNA in the polymerase chain reaction hybridization assay . In conclusion, we found that both tobramycin-containing bone cement and systemic cefazolin are effective in preventing implant bed infection in rabbits up to 7 days after contamination with S . aureus .

J Biomed Mater Res, 2000 Dec 15, 52(4), 662 - 8
A mechanistic study of the antibacterial effect of silver ions on Escherichia coli and Staphylococcus aureus; Feng QL et al.; To investigate the mechanism of inhibition of silver ions on microorganisms, two strains of bacteria, namely Gram-negative Escherichia coli (E . coli) and Gram-positive Staphylococcus aureus (S . aureus), were treated with AgNO(3) and studied using combined electron microscopy and X-ray microanalysis . Similar morphological changes occurred in both E . coli and S . aureus cells after Ag(+) treatment . The cytoplasm membrane detached from the cell wall . A remarkable electron-light region appeared in the center of the cells, which contained condensed deoxyribonucleic acid (DNA) molecules . There are many small electron-dense granules either surrounding the cell wall or depositing inside the cells . The existence of elements of silver and sulfur in the electron-dense granules and cytoplasm detected by X-ray microanalysis suggested the antibacterial mechanism of silver: DNA lost its replication ability and the protein became inactivated after Ag(+) treatment . The slighter morphological changes of S . aureus compared with E . coli recommended a defense system of S . aureus against the inhibitory effects of Ag(+) ions .

Am J Otolaryngol, 2000 Sep-Oct, 21(5), 298 - 305
Computed tomography vs . magnetic resonance imaging of acute bacterial sinusitis: a rabbit model; Kerschner JE et al.; PURPOSE: Computed topography (CT) and magnetic resonance imaging (MRI) are important, both clinically and in a research setting, in assessing bacterial sinusitis (BS) . The use of CT scanning to evaluate sinus opacification in a reversible model of rabbit acute sinusitis has been reported . MRI offers the potential for better visualization of soft tissue and fluid changes within the paranasal sinuses . MRI has potential as a research tool in animal models of sinusitis . This article compares the use of CT and MRI in measuring maxillary sinus opacification in rabbits during experimental, reversible BS . MATERIALS AND METHODS: In 2 independent trials, New Zealand White rabbits were imaged for baseline anatomy, and BS was generated by sinus inoculation with Staphylococcus aureus . Serial imaging was performed as a measure of the progression and resolution of BS during the trials . Two experienced, independent reviewers then scored each CT and MRI for percent opacification of the maxillary sinus . These scores were analyzed to assess the degree of agreement between the reviewers . RESULTS: The correlation coefficients for CT and MRI were 0.6816 and 0.3584, respectively . The Z-statistic comparing these correlation coefficients was significant (P < .0001), indicating that CT is a more precise measure of reversible BS in this rabbit model . Differences in mean scan time and cost per scan were also significantly different (P < .0001), with CT being both quicker and less expensive . CONCLUSIONS: Greater interobserver consistency of scan interpretation, with less time and cost, make CT the preferred tool for measuring BS in this rabbit model . Attributes of MRI such as better resolution of fluid-tissue interfaces and custom surface coil design for visualization of specific anatomic structures are discussed as they may increase the effectiveness of MRI as an imaging modality in future sinusitis research.

Int J Food Microbiol, 2000 Oct 1, 61(1), 1 - 10
Staphylococcal enterotoxins; Balaban N et al.; Staphylococcus aureus is a major human pathogen that produces a wide array of toxins, thus causing various types of disease symptoms . Staphylococcal enterotoxins (SEs), a family of nine major serological types of heat stable enterotoxins, are a leading cause of gastroenteritis resulting from consumption of contaminated food . In addition, SEs are powerful superantigens that stimulate non-specific T-cell proliferation . SEs share close phylogenetic relationships, with similar structures and activities . Here we review the structure and function of each known enterotoxin.

Shock, 2000 Sep, 14(3), 253 - 7; discussion 257-8
Differential effect of caspase inhibition on proinflammatory cytokine release in septic patients; Oberholzer A et al.; The interleukins (IL)-1beta and IL-18 represent potent players in the proinflammatory cytokine cascade . Their activation is regulated predominantly through the IL-1-converting enzyme (ICE)/caspase-1 . The role of caspases in the secretion of IL-1beta and IL-18, as well as in the release of the secondary-induced cytokines IL-12 and interferon (IFN)-gamma in whole blood from septic patients compared to healthy controls, was studied . Inhibition of caspase activity by Z-VAD significantly reduced lipopolysaccharide (LPS) and Staphylococcus aureus (SAC) induced release of mature IL-1beta in septic patients and controls . In contrast, in whole blood from septic patients significantly elevated basal level of IL-18 were found, which could neither be further increased by LPS or SAC, nor be inhibited by Z-VAD . Release of IL-12 p40 was significantly lower in septic patients compared to controls and was not affected by Z-VAD . Despite high levels of IL-18, IFN-gamma was not detected in whole blood from septic patients even after stimulation with SAC or LPS . Thus, during sepsis, caspases participate in the processing of IL-1beta, whereas maturation of IL-18 during sepsis appears to be independent of caspases . The lack of IFN-gamma release seen in septic patients could be attributed to low IL-12 release rather than to diminished IL-18 release.

Arch Intern Med, 2000 Oct 9, 160(18), 2781 - 7
Neurologic manifestations of infective endocarditis: a 17-year experience in a teaching hospital in Finland; Heiro M et al.; BACKGROUND: Many previous studies have endeavored to find appropriate means to reduce the occurrence of neurologic manifestations in patients with infective endocarditis (IE) . We evaluated patients with IE-associated neurologic complications and compared them with patients with IE who did not have neurologic symptoms . Particular attention was focused on assessing the impact of cardiac surgery and the presence of potential risk factors for complications on the outcome of the patients . METHODS: A total of 218 episodes designated as definite or possible IE according to Duke criteria and treated during the years 1980 through 1996 in a Finnish teaching hospital were retrospectively evaluated for neurologic manifestations . RESULTS: Neurologic complications were identified in 55 episodes (25%), with an embolic event as the most frequent manifestation (23/55; 42%) . In the majority (76%) of episodes, the neurologic manifestation was evident before antimicrobial treatment was started, being the first sign of IE in 47% of episodes . Only 1 recurrent cerebral embolization was observed . Neurologic complications were significantly associated with Staphylococcus aureus infection (29% vs 10%; P =.001) and with IE affecting both the aortic and the mitral valves (56% vs 23%; P<.01), but not with echocardiographic detection of vegetations or anticoagulant therapy . Death during the acute phase of IE occurred in 13 episodes (24%) with neurologic complications and in 17 episodes (10%) without neurologic complications (P<.03) . In episodes with neurologic complications, the IE-associated mortality rate was 25% (10/40) in the medical treatment group and 20% (3/15) in the surgical group . No neurologic deterioration was observed in these surgically treated patients postoperatively . CONCLUSIONS: Our results reinforce the belief that rapid diagnosis and initiation of antimicrobial therapy may still be the most effective means to prevent neurologic complications . These data underscore the importance of diagnostic alertness to the prognosis of patients with IE.

Catheter Cardiovasc Interv, 2000 Oct, 51(2), 196 - 8
Successful conservative treatment of an infected central venous stent; Naddour F et al.; Several cases of stent infection have been reported in the medical literature . Most required surgical removal of the stent, sometimes with severe sequelae including limb loss . We report the case of a 39-year-old hemodialysis patient who, 3 weeks prior to admission, had undergone angioplasty of the right innominate and subclavian veins with implantation of a Wallstent . He was admitted to the hospital with sepsis due to Staphylococcus aureus and had histological evidence of endovascular infection within the stent . The patient was successfully treated with a 6-week course of intravenous antibiotics delivered directly into the stent, thus avoiding the need for surgical removal of the device.

J Ethnopharmacol, 2000 Nov, 73(1-2), 243 - 9
Seasonal effect on Brazilian propolis antibacterial activity; Sforcin JM et al.; The behavior of microorganisms towards the antibiotic action of propolis has been widely investigated . Since reports dealing with seasonal effect on propolis activity are not available, this assay was carried out aiming to observe the in vitro antimicrobial activity of propolis, collected during the four seasons, on bacterial strains isolated from human infections . Dilution of ethanolic extract of propolis (EEP) in agar was the method performed, with serial concentrations ranging from 0.4 to 14.0% (% v/v) . The behavior of some bacteria was analysed according to the incubation period in medium plus propolis, and the survival curve was plotted . It was verified that the growth of Gram-positive bacteria is inhibited by low propolis concentrations (0.4%) whereas Gram-negative bacteria were less susceptible to this substance, the minimal inhibitory concentration ranging from 4.5 to 8.0% . There was no significant difference with regards to the seasonal effect on the survival curve of Staphylococcus aureus and Escherichia coli; after incubation with propolis, there was an efficient antimicrobial action, mainly towards Gram-positive bacteria.

FEMS Immunol Med Microbiol, 2000 Oct, 29(2), 155 - 62
An epidemiological study on the occurrence of Staphylococcus aureus in superficial abscesses of patients presenting for surgery in a teaching hospital in Khartoum, Sudan; Mahdi SE et al.; A group of patients (n=86) suffering from superficial abscesses was recruited in the Khartoum Teaching Hospital, Sudan . Detailed clinical and socio-economic data were collected . It appeared that 83% of all patients were younger than 40 . Labourers were most prevalent (28%), followed by students (23%) and housewives (16%) . The head and neck were most often affected (22%), with hands being second (19%) . In 92% of all pus cultures a microbial agents was identified, the large majority being Staphylococcus aureus (69%) . Among patients, 47% were nasal carriers of S . aureus, similar to the carriage rate measured among controls, suggesting that nasal carriage is no risk factor for abscess development . Multivariate logistic regression analysis revealed that a history of abscess, recent traditional medical treatment, poor hygiene and low socio-economic status were significantly and independently associated with the occurrence of superficial abscesses.

FEMS Immunol Med Microbiol, 2000 Oct, 29(2), 145 - 53
Human antibody response during sepsis against targets expressed by methicillin resistant Staphylococcus aureus; Lorenz U et al.; The identification of target structures is a prerequisite for the development of new treatment options, like antibody based therapy, against methicillin resistant Staphylococcus aureus (MRSA) . In this study we identified immunodominant structures which were expressed in vivo during sepsis caused by MRSA . Using human sera we compared the immune response of humans with MRSA sepsis with the immune response of normal individuals and asymptomatically colonized individuals . We identified and characterized four staphylococcal specific antigenic structures . One target is a staphylococcal protein of 29 kDa that exhibited 29% identity to secreted protein SceA precursor of Staphylococcus carnosus . The putative function of this protein, which was designated IsaA (immunodominant staphylococcal antigen), is unknown . The second target is an immunodominant protein of 17 kDa that showed no homology to any currently known protein . This immunodominant protein was designated IsaB . The third and fourth antigens are both immunodominant proteins of 10 kDa . One of these proteins showed 100% identity to major cold shock protein CspA of S . aureus and the other protein was identified as the phosphocarrier protein Hpr of S . aureus . The identified immunodominant proteins may serve as potential targets for the development of antibody based therapy against MRSA.

FASEB J, 2000 Dec, 14(15), 2380 - 2
Anti-inflammatory effects of sodium butyrate on human monocytes: potent inhibition of IL-12 and up-regulation of IL-10 production; Saemann MD et al.; Cytokines are critical in regulating unresponsiveness versus immunity towards enteric antigens derived from the intestinal flora and ingested food . There is increasing evidence that butyrate, a major metabolite of intestinal bacteria and crucial energy source for gut epithelial cells, also possesses anti-inflammatory properties . Its influence on cytokine production, however, is not established . Here, we report that butyrate strongly inhibits interleukin-12 (IL-12) production by suppression of both IL-12p35 and IL-12p40 mRNA accumulation, but massively enhances IL-10 secretion in Staphylococcus aureus cell-stimulated human monocytes . The effect of butyrate on IL-12 production was irreversible upon the addition of neutralizing antibodies to IL-10 or transforming growth factor b1 and of indomethacin . In anti-CD3-stimulated peripheral blood mononuclear cells, butyrate enhanced IL-10 and IL-4 secretion but reduced the release of IL-2 and interferon-g . The latter effect was in part a result of suppressed IL-12 production but also a result of inhibition of IL-12 receptor expression on T cells . These data demonstrate a novel anti-inflammatory property of butyrate that may have broad implications for the regulation of immune responses in vivo and could be exploited as new therapeutic approach in inflammatory conditions.

Clin Microbiol Rev, 2000 Oct, 13(4), 686 - 707
Vancomycin-resistant enterococci; Cetinkaya Y et al.; After they were first identified in the mid-1980s, vancomycin-resistant enterococci (VRE) spread rapidly and became a major problem in many institutions both in Europe and the United States . Since VRE have intrinsic resistance to most of the commonly used antibiotics and the ability to acquire resistance to most of the current available antibiotics, either by mutation or by receipt of foreign genetic material, they have a selective advantage over other microorganisms in the intestinal flora and pose a major therapeutic challenge . The possibility of transfer of vancomycin resistance genes to other gram-positive organisms raises significant concerns about the emergence of vancomycin-resistant Staphylococcus aureus . We review VRE, including their history, mechanisms of resistance, epidemiology, control measures, and treatment.

J Hosp Infect, 2000 Sep, 46(1), 43 - 9
Effect of delayed infection control measures on a hospital outbreak of methicillin-resistant Staphylococcus aureus; Harbarth S et al.; All patients positive for methicillin-resistant Staphylococcus aureus (MRSA) at the University Hospitals of Geneva, Switzerland, between 1989 and 1997 (N = 1771) were included in a cohort study to evaluate the consequences of delayed containment of a hospital-wide outbreak occurring during a 4-year absence of MRSA control measures . The effects of efforts to control both the MRSA reservoir and the number of bacteraemic patients were assessed . Intensive infection control measures were initiated in 1993 and included patient screening, on-site surveillance, contact isolation, a computerized alert system, and hospital-wide promotion of hand hygiene . An increase in the rate of new MRSA-infected or -colonized patients was observed between 1989 and 1994 (from 0.05 to 0.60 cases per 100 admissions), which subsequently decreased to 0.24 cases in 1997 (P<0.001) . However, the proportion of laboratory-documented methicillin-resistant isolates among all S . aureus showed little variation in the years from 1993 onwards (range, 19-24%), reflecting the result of an increase in the number of screening cultures . The annual number of patients with MRSA bacteraemia strongly correlated with the hospital-wide prevalence of MRSA patients (R(2)= 0.60; P = 0.01) and the rate of new MRSA patients (R(2)= 0.97; P<0.001) . Consequently, the attack rate of nosocomial MRSA bacteraemia served as an excellent marker for the MRSA patient reservoir . In conclusion, despite delayed implementation, infection control measures had a substantial impact on both the reservoir of MRSA patients and the attack rate of MRSA bacteraemia.

Blood, 2000 Oct 15, 96(8), 2649 - 54
Up-regulation of HIV coreceptors CXCR4 and CCR5 on CD4(+) T cells during human endotoxemia and after stimulation with (myco)bacterial antigens: the role of cytokines; Juffermans NP et al.; Concurrent infections in patients with human immunodeficiency virus (HIV) infection stimulate HIV replication . Chemokine receptors CXCR4 and CCR5 can act as HIV coreceptors . The authors hypothesized that concurrent infection increases the HIV load through up-regulation of CXCR4 and CCR5 . Using experimental endotoxemia as a model of infection, changes in HIV coreceptor expression were assessed in 8 subjects injected with lipopolysaccharide (LPS, 4 ng/kg) . The expression of CXCR4 and CCR5 on CD4(+) T cells was increased 2- to 4-fold, 4 to 6 hours after LPS injection . In whole blood in vitro, LPS induced a time- and dose-dependent increase in the expression of CXCR4 and CCR5 on CD4(+) T cells . Similar changes were observed after stimulation with cell wall components of Mycobacterium tuberculosis (lipoarabinnomannan) or Staphylococcus aureus (lipoteichoic acid), or with staphylococcal enterotoxin B . LPS increased viral infectivity of CD4-enriched peripheral blood mononuclear cells (PBMCs) with a T-tropic HIV strain . In contrast, M-tropic virus infectivity was reduced, possibly because of elevated levels of the CCR5 ligand cytokines RANTES and MIP-1beta . LPS-stimulated up-regulation of CXCR4 and CCR5 in vitro was inhibited by anti-TNF and anti-IFN gamma . Incubation with recombinant TNF or IFN gamma mimicked the LPS effect . Anti-interleukin 10 (anti-IL-10) reduced CCR5 expression, without influencing CXCR4 . In accordance, rIL-10 induced up-regulation of CCR5, but not of CXCR4 . Intercurrent infections during HIV infection may up-regulate CXCR4 and CCR5 on CD4(+) T cells, at least in part via the action of cytokines . Such infections may favor selectivity of HIV for CD4(+) T cells expressing CXCR4 . (Blood . 2000;96:2649-2654)

Southeast Asian J Trop Med Public Health, 2000 Mar, 31(1), 72 - 6
Epidemiological analysis of methicillin resistant Staphylococcus aureus in Thailand; Wongwanich S et al.; The geographical distribution of 65 clinical isolates of methicillin resistant Staphylococcus aureus (MRSA) recovered from 7 hospitals in Thailand was investigated . The presence of mecA gene in MRSA was determined by specific PCR with the use of primers 5'-GTAGTTGTCGGGTTTGGT-3' and 5'-GGTATCATCTTGTACCCA-3' . Chromosomal DNA restriction analysis with SmaI was resolved by pulsed-field gel electrophoresis (PFGE) compared with antibiotype analysis and phage type analysis . All 65 strains carried mecA gene . They all were resistant to penicillin, tetracycline, erythromycin, amoxicillin/clavulanic acid and variably resistant to gentamicin, ofloxacin, trimethoprim-sulfamethoxazole, chloramphenicol, fosfomycin and clindamycin; and all isolates were susceptible to vancomycin . A total of 19 PFGE patterns designated as type A, A1, A2, A3, A4, B, B1, C, D, E, E1, E2, F, F1, F2, G, H, I and J was identified . Type A4 and E were commonly found in every studied areas . Phage typing showed even greater variability that 52 (80%) isolates belonged to 25 different phage types; 13 (20%) isolates were non-typable . The clarity and polymorphism of the PFGE patterns enable us to discriminate between isolates which could not be differentiated by antibiogram or phage type analysis . The findings demonstrate the existence of a common epidemic MRSA clone in Thailand.

Microbiol Immunol, 2000, 44(8), 653 - 6
Firm adherence of Staphylococcus aureus and Staphylococcus epidermidis to human hair and effect of detergent treatment; Mase K et al.; Staphylococcus aureus and S . epidermidis are common pathogens in hospitals, and care should be taken not to disseminate these organisms among patients . We have focused on human hair as a source of bacterial contamination . We treated hair with culture solutions of S . aureus and S . epidermidis, and then performed scanning electron microscopy . Bacteria were detected on the surface of the cuticles of the hair, and the attached bacteria were not completely removed even by repeated washing with detergents . These results suggested that hair could be a source of bacterial contamination and indicated the importance of decontamination of hair.

J Med Chem, 2000 Oct 5, 43(20), 3809 - 12
Synthesis, antibacterial, and cytotoxic evaluation of certain 7-substituted norfloxacin derivatives; Fang KC et al.; We report herein the synthesis and biological evaluation of two series of 7-substituted norfloxacin derivatives . Most compounds tested in this study demonstrated better activity against methicillin-resistant Staphylococcus aureus than norfloxacin . Preliminary in vitro evaluation indicated that the 7-{4-(2-hydroxyiminoethyl)piperazin-1-yl} derivatives 3b-e possess distinct cytotoxicity profiles as compared with their alpha-methylene-gamma-butyrolactone counterparts, 4b,e: i.e., excellent activities against the renal cancer subpanel . Among them, 1-ethyl-6-fluoro-7- inverted question mark4-{2-(4-chlorophenyl)-2-hydroxyiminoethyl}-1-p ipe razinyl inverted question mark-4-oxo-1,4-dihydro-3-quinolinecarboxylic acid (3d) demonstrated the most significant activities against renal cancer cell lines, with log GI(50) values of -6.40 against CAK-1, -6.14 against RXF 393, and -7.54 against UO-31, compared with a mean log GI(50) value of -5.03.

J Antimicrob Chemother, 2000 Oct, 46(4), 633 - 8
Sitafloxacin in the treatment of patients with infections caused by vancomycin-resistant enterococci and methicillin-resistant Staphylococcus aureus; Shetty N et al.; Sitafloxacin is a new quinolone active against multi-resistant Gram-positive pathogens . An open study was conducted in patients with serious systemic infections with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant enterococcus (VRE) . Patients with MRSA were recruited if treatment with glycopeptides had failed . Of 11 patients with MRSA infection, four were cured, six failed treatment and one was indeterminate . Of nine patients with VRE infection (one patient had both pathogens), five were cured and four failed . Fifteen adverse events in 12 patients were potentially related to the study drug . Sitafloxacin was effective in VRE and some recalcitrant MRSA infections.

J Antimicrob Chemother, 2000 Oct, 46(4), 617 - 20
In vivo deletion of the methicillin resistance mec region from the chromosome of Staphylococcus aureus strains; Deplano A et al.; Two sets of Staphylococcus aureus isolates recovered from two patients exhibited similar susceptibility profiles except for oxacillin susceptibility (MSSA) or resistance (MRSA) . SMA:I macrorestriction and inter-IS256 PCR analysis showed patterns closely related to the Belgian epidemic MRSA clone 1 in each pair of MSSA/MRSA strains . Loss of one large SMA:I DNA fragment and concurrent gain of a smaller fragment in the MSSA isolates was observed . The mecA sequence present in the MRSA was absent in the MSSA variant . Therefore, in vivo deletion of the mec region may occur in some lineages of S . aureus more frequently than previously thought.

Clin Pharmacokinet, 2000 Sep, 39(3), 167 - 83
Clinical pharmacokinetics of teicoplanin; Wilson AP; The glycopeptide antibacterial teicoplanin has become increasingly popular in the last decade with the rise in infections related to methicillin-resistant Staphylococcus aureus . Teicoplanin has 6 major and 4 minor components . It is predominantly (90%) bound to plasma proteins . Of the several methods available to measure concentrations in serum, fluorescence polarisation immunoassay has high reliability and specificity . Teicoplanin is not absorbed orally, but intravenous and intramuscular administration are well tolerated . Teicoplanin is eliminated predominantly by the kidneys and only 2 to 3% of an intravenously administered dose is metabolised . Total clearance is 11 ml/h/kg . Steady state is reached only slowly, 93% after 14 days of repeated administration . Elimination is triexponential, with half-lives of 0.4 to 1.0, 9.7 to 15.4 and 83 to 168 hours . Volumes of distribution are 0.07 to 0.11 (initial phase), 1.3 to 1.5 (distribution phase) and 0.9 to 1.6 (steady state) L/kg . A standard dosage regimen of 6 mg/kg every 12 hours for 3 doses, then daily, will produce therapeutic serum concentrations of > or = 10 mg/L in most patients . Higher dosages may be required in certain patients, for example intravenous drug abusers or those with burns, because of unpredictable clearance . Concentrations in bone reach 7 mg/L at 12 hours after a dose of teicoplanin 6 mg/kg, but reach only 3.5 mg/L in the cartilage . Doses of 10 mg/kg are necessary to achieve adequate bone concentrations . There is little penetration into cerebrospinal fluid or the aqueous or vitreous humour . In fat, concentrations may be subtherapeutic (0.5 to 5 mg/L) after a dose of 400mg . A single prophylactic dose of 12 mg/kg is sufficient to maintain therapeutic concentrations during cardiopulmonary bypass or burns surgery . High loading doses reduce the delay to attaining therapeutic concentrations . Premature neonates require a loading dose of 15 mg/kg and a maintenance dosage of 8 mg/kg daily to ensure therapeutic serum concentrations . Children need loading with 10 mg/kg every 12 hours for 3 doses followed by maintenance with 10 mg/kg/day . Clearance is reduced predictably in renal failure, and dosage adjustments can be based on the ratio of impaired clearance to normal clearance . In patients on haemodialysis, 3 loading doses of 6 mg/kg at 12-hour intervals followed by maintenance doses every 72 hours produced trough plasma concentrations of 8 mg/L in most patients at 48 hours . The monitoring of serum concentrations is not necessary to avoid toxicity, but can be helpful in certain patient groups to ensure therapeutic concentrations are present, especially in those not responding to treatment.

Nihon Kokyuki Gakkai Zasshi, 2000 Jul, 38(7), 561 - 5
{A case of Wegener's granulomatosis with pachymeningitis}; Niimi T et al.; A 62-year-old woman who had been receiving corticosteroid therapy for pachymeningitis since 1997 was admitted to our hospital when an abnormal shadow was noticed in her chest radiograph . In bronchial and nasal mucosal biopsies, the findings of a necrotic granulomatous lesion and vasculitis were compatible with Wegener's granulomatosis, although this is rarely seen with pachymeningitis . After further corticosteroid therapy together with cyclophosphamide treatment, the size of the thoracic X-ray shadow decreased . Methicillin-resistant Staphylococcus aureus (MRSA) was cultured from the sputum and the nasal fluid, and may have contributed to the advance of the disease in the airway . This case will require continuing careful observation.

Kansenshogaku Zasshi, 2000 Aug, 74(8), 653 - 7
{Search for Staphylococcus aureus heterogeneously resistant to vancomycin (hetero-VRSA) in MRSA strains isolated from clinical samples during 1990s}; Nakamachi Y et al.; Hetero-VRSA was studied in 978 MRSA strains isolated from clinical samples during 1991 to 1998 . Although no VRSA was detected, 23 strains (2.4%) were identified as hetero-VRSA by the vancomycin-resistance using MU3 agar plate . The frequency of hetero-VRSA was not increased in the course of time . MIC of the hetero-VRSA to vancomycin and teicoplanin was 1-2 micrograms/ml and 0.5-12 micrograms/ml, respectively . All of the hetero-VRSA strains were confirmed as a heterogeneous strain by a population analysis . Although 43% of the hetero-VRSA strains were coagulase type II, positive for TSST-1, and enterotoxin type C, others were various in the characteristics . In the gene analysis by pulse field gelelectrophoresis (PFGE), 4 sets of 2 strains were found to be identical among the 23 strains but the other 15 strains were genetically different . We speculate that hetero-VRSA strains were generated in 1991 secondary possibly by use of beta-lactam antibiotics.

Sao Paulo Med J, 2000 Sep 7, 118(5), 158 - 60
Musculoskeletal manifestations of bacterial endocarditis; Rangel EB et al.; CONTEXT: The incidence of staphylococcal infection has been increasing during the last 20 years . OBJECTIVE: Report a case of staphylococcal endocarditis preceded by musculoskeletal manifestations, which is a rare form of clinical presentation . DESIGN: Case report . CASE REPORT: A 45-year-old-man, without addictions and without known previous cardiopathy, was diagnosed as having definitive acute bacterial endocarditis due to Staphylococcus aureus . Its etiology was community-acquired, arising from a non-apparent primary focus . In addition, the musculoskeletal symptoms preceded the infective endocarditis (IE) by about 1 month, which occurred together with other symptoms, e.g . mycotic aneurysms and petechiae . Later, the patient showed perforation of the mitral valve and moderate mitral insufficiency with clinical control.

Arq Neuropsiquiatr, 2000 Sep, 58(3B), 843 - 51
Staphylococcus aureus meningitis in children: a review of 30 community-acquired cases; Rodrigues MM et al.; In spite of the steady increase in the incidence of Staphylococcus aureus infections, it remains a relatively uncommon cause of meningitis . To our knowledge, no series of community-acquired S . aureus meningitis (CASAM) restricted to children has been published . So far in this retrospective study we report our experience with CASAM in children, hospitalized from 1983 to 1998 at Nossa Senhora da Gloria Children's Hospital (HINSG) . During the sixteen-year study period, 2,319 new cases of acute pyogenic meningitis were diagnosed at HINSG . Community-acquired S . aureus was identified as the causative agent in 30 patients (1.3 percent) . The predominantly spinal localization of the agent is stressed . In contrast with publications which analyze adults, it has a better prognosis.

Microbes Infect, 2000 Sep, 2(11), 1383 - 92
Immunotherapy against antibiotic-resistant bacteria: the Russian experience with an antistaphylococcal hyperimmune plasmaand immunoglobulin; Kelly J; The Russian experience with the preparation and clinical application of an antitoxic antistaphylococcal hyperimmune plasma and immunoglobulin is described . The immunotherapies were developed in the late 1960s and put into widespread use in the Soviet Union for the prophylaxis and treatment of sepsis, pneumonia, and other conditions caused by an epidemic of antibiotic-resistant Staphylococcus aureus.

Clin Infect Dis, 2000 Sep, 31(3), 723 - 7 Epub 2000 Oct 04.
Adults with meningitis caused by oxacillin-resistant Staphylococcus aureus; Lu CH et al.; Since 1995, 11 adult patients with oxacillin-resistant Staphylococcus aureus (ORSA) meningitis have been identified at Chang Gung Memorial Hospital-Kaohsiung, in Kaohsiung, Taiwan . The 11 patients were 8 men and 3 women, aged 17-78 years . A postneurosurgical state was an underlying condition for all, and fever and disturbances in consciousness were the most common clinical manifestations . Infection with S . aureus only was found in 8 patients, and mixed infection was found in the other 3 . The 8 patients with meningitis caused by S . aureus only were mainly treated with intravenous vancomycin, 2-4 g/day; 4 of these patients died . Although ORSA meningitis is uncommon among adults with culture-proven bacterial meningitis, its incidence has been increasing in recent years . The diagnosis of adult ORSA meningitis can be confirmed only with a positive culture of cerebrospinal fluid, and the choice of initial empirical antibiotics must be guided by the accumulated data concerning the relative frequency of the implicated pathogens found at each institution . Despite the high rate of mortality associated with ORSA meningitis, intravenous vancomycin therapy seems to be one of the best choices for management of this condition in adults.

Clin Infect Dis, 2000 Sep, 31(3), 684 - 9 Epub 2000 Oct 04.
Analysis of 42 cases of septicemia caused by an epidemic strain of methicillin-resistant Staphylococcus aureus: evidence of resistance to vancomycin; Burnie J et al.; Recent case reports of vancomycin treatment failures in the United States, Japan, and France have prompted a retrospective analysis of 42 cases of septicemia caused by epidemic methicillin-resistant Staphylococcus aureus strain 15 (EMRSA-15), which is the most prevalent epidemic strain of methicillin-resistant S . aureus in the United Kingdom; all cases occurred in a teaching hospital in Manchester, United Kingdom, between 1994 and 1998 . Mortality was lowest (4%) in patients with rifampin-susceptible isolates treated with vancomycin and rifampin . It rose to 38% in patients who were treated with both antibiotics but in whom the organism became resistant to rifampin during therapy, and it reached 78% in patients who had rifampin-resistant isolates or in whom rifampin was contraindicated (P<.0001; Fisher exact test, 2-tailed) . All isolates were susceptible to vancomycin by conventional laboratory testing, but susceptibility was lost by growth in vancomycin in vitro, becoming resistant at a minimum inhibitory concentration of 8 mg/L . This was associated with accumulation of cell-wall material . The deoxyribonucleic acid fingerprint remained unchanged . This study suggests that rifampin played a key role in the prevention of deaths caused by an epidemic strain of methicillin-resistant S . aureus that readily gave rise to a subpopulation with reduced susceptibility to vancomycin.

J Clin Microbiol, 2000 Oct, 38(10), 3879 - 81
Vancomycin-intermediate Staphylococcus aureus in Korea; Kim MN et al.; Recent reports on some methicillin-resistant Staphylococcus aureus (MRSA) with reduced susceptibility to vancomycin have been a major concern in Korea because of the widespread use of vancomycin due to a high prevalence of MRSA in the country . We describe a 45-year-old man with long-standing pelvic abscess due to MRSA . In spite of vancomycin and teicoplanin treatment for a long period of time, the patient died from MRSA sepsis . The blood culture isolate of MRSA exhibited reduced susceptibility to vancomycin (MIC, 8 microg/ml) . This is the first report of a vancomycin-intermediate S . aureus case from Korea.

J Clin Microbiol, 2000 Oct, 38(10), 3867 - 9
Molecular analysis of methicillin-resistant Staphylococcus aureus as a causative agent of bronchopulmonary infection: relation to colonization in the upper respiratory tract; Watanabe H et al.; Using five diagnostic markers, we compared the types of 72 strains of methicillin-resistant Staphylococcus aureus (MRSA) isolated simultaneously from the nasal cavity, pharynx, and sputum from 24 patients . Almost identical MRSA types had colonized the nasal cavity and sputum from the same patient for 21 (88%) of the patients . We speculate that most MRSA organisms isolated in sputum are derived from the nasal cavity, while a few are derived from the pharynx.

J Clin Microbiol, 2000 Oct, 38(10), 3746 - 9
Characterization of Staphylococcus aureus coagulase type VII isolates from staphylococcal food poisoning outbreaks (1980-1995) in Tokyo, Japan, by pulsed-field gel electrophoresis; Shimizu A et al.; Staphylococcus aureus coagulase type VII strains have been the strains most frequently isolated from staphylococcal food poisoning outbreaks in Tokyo, Japan . We applied pulsed-field gel electrophoresis (PFGE) of chromosomal DNA digested with SmaI to characterize 129 coagulase type VII strains . These were isolated from 129 cases occurring in outbreaks in 35 districts during a 16-year period (1980-1995) . The 129 outbreak strains were classified into three types, designated A (n = 115), B (n = 10), and C (n = 4) . Types A and C were further divided into 33 (A1 to A33) and 4 (C1 to C4) subtypes, respectively . Strains of the same subtypes were isolated from food poisoning cases in the same districts at time intervals of 1 or 2 to 5 years . PFGE typing appears to be a useful method for subdividing strains of S . aureus coagulase type VII . A combination of coagulase typing and PFGE typing would provide more detailed information than the former method alone in epidemiologic investigations of staphylococcal food poisoning.

J Clin Microbiol, 2000 Oct, 38(10), 3527 - 33
Multicenter evaluation of epidemiological typing of methicillin-resistant Staphylococcus aureus strains by repetitive-element PCR analysis . The European Study Group on Epidemiological Markers of the ESCMID; Deplano A et al.; Rapid and efficient epidemiologic typing systems would be useful to monitor transmission of methicillin-resistant Staphylococcus aureus (MRSA) at both local and interregional levels . To evaluate the intralaboratory performance and interlaboratory reproducibility of three recently developed repeat-element PCR (rep-PCR) methods for the typing of MRSA, 50 MRSA strains characterized by pulsed-field gel electrophoresis (PFGE) (SmaI) analysis and epidemiological data were blindly typed by inter-IS256, 16S-23S ribosomal DNA (rDNA), and MP3 PCR in 12 laboratories in eight countries using standard reagents and protocols . Performance of typing was defined by reproducibility (R), discriminatory power (D), and agreement with PFGE analysis . Interlaboratory reproducibility of pattern and type classification was assessed visually and using gel analysis software . Each typing method showed a different performance level in each center . In the center performing best with each method, inter-IS256 PCR typing achieved R = 100% and D = 100%; 16S-23S rDNA PCR, R = 100% and D = 82%; and MP3 PCR, R = 80% and D = 83% . Concordance between rep-PCR type and PFGE type ranged by center: 70 to 90% for inter-IS256 PCR, 44 to 57% for 16S-23S rDNA PCR, and 53 to 54% for MP3 PCR analysis . In conclusion, the performance of inter-IS256 PCR typing was similar to that of PFGE analysis in some but not all centers, whereas other rep-PCR protocols showed lower discrimination and intralaboratory reproducibility . None of these assays, however, was sufficiently reproducible for interlaboratory exchange of data.

Eur J Clin Microbiol Infect Dis, 2000 Aug, 19(8), 612 - 7
In vitro zones of inhibition of coated vascular catheters predict efficacy in preventing catheter infection with Staphylococcus aureus in vivo; Bassetti S et al.; This report summarizes data from 35 rabbit model experiments investigating the relationship between in vitro anti-infective catheter coating zones of inhibition and in vivo efficacy . The rabbit model studies involving 15 anti-infective coatings demonstrate an inverse correlation between the sizes of zones of inhibition of Staphylococcus aureus and both the quantity of Staphylococcus aureus removed from the catheter and the risk of a purulent infection . The review of seven previously published clinical trials reveals that the use of anti-infective coated catheters, efficacious in the rabbit model, was associated with a higher success rate than the use of uncoated catheters in preventing both Staphylococcus aureus catheter colonization (odds ratio: 1.28; 95% confidence interval: 0.84-1.93) and Staphylococcus aureus catheter-related bloodstream infection (odds ratio: 3.07; 95% confidence interval: 0.98-9.60) in humans . These findings strongly suggest a correlation between zones of inhibition and in vivo efficacy . In vitro zones of inhibition may serve as a useful screening test for evaluating new anti-infective coatings.

Eur J Pediatr, 2000 Sep, 159(9), 689 - 91
Staphylococcus aureus septicaemia in a patient with cystic fibrosis; Aebischer CC et al.; Although bacterial colonisation of bronchi may occur from early childhood onwards, infections extending beyond the lungs are uncommon in patients with cystic fibrosis . A 12-year-old boy with cystic fibrosis, receiving oral corticosteroids for 3 weeks because of allergic bronchopulmonary aspergillosis, experienced pneumonia and septicaemia caused by Staphylococcus aureus . He was treated with flucloxacillin, ticarcillin-clavulanate, aztreonam, cefazolin and rifampin according to resistance testing of S . aureus cultured from the blood . On day 25 the patient finally had recovered . CONCLUSION: Systemic steroid therapy for allergic bronchopulmonary aspergillosis may favour life-threatening systemic bacterial infection which is rare in the immunocompetent patient with cystic fibrosis.

Arthritis Rheum, 2000 Sep, 43(9), 2073 - 80
The effects of local administration of lactoferrin on inflammation in murine autoimmune and infectious arthritis; Guillen C et al.; OBJECTIVE: To determine whether lactoferrin can modify articular inflammation in murine models of autoimmune and septic arthritis . METHODS: Collagen arthritis was induced in DBA/1 mice and Staphylococcus aureus septic arthritis in Swiss mice . Joints with established inflammation were injected periarticularly with 0.5 mg or 1 mg of human lactoferrin, and arthritis was monitored for 3 days . RESULTS: DBA/1 mice injected with lactoferrin showed significantly suppressed local inflammation for up to 3 days, achieving up to 71% of the effect of corticosteroid . Periarticular injection of 125I-lactoferrin confirmed that 25% of lactoferrin was retained in paws after 6 hours . Serum levels of interleukin-6, however, were not significantly reduced, suggesting a predominantly local antiinflammatory effect . Similarly, local, periarticular administration of lactoferrin into S aureus-infected Swiss mice significantly suppressed paw inflammation and did not enhance bacterial survival . CONCLUSION: Lactoferrin may have clinical utility in reducing articular inflammation, particularly in septic arthritis, in which antiinflammatory effects may be achieved without promoting bacterial survival.

Z Kardiol, 2000 Aug, 89(8), 691 - 7
{Impediment of cellular immune response under treatment with ticlopidine in a patient with Staphylococcus aureus endocarditis}; Alter P et al.; A 52-year-old male with coronary artery disease was admitted with acute aortic valve endocarditis and a temperature up to 39.5 degrees C caused by Staphylococcus aureus . The patient was treated with ticlopidine (Tiklyd) after percutaneous transluminal coronary angioplasties to reduce restenosis by inhibiting thrombocyte aggregation . Upon admission c-reactive protein (CRP) was 389 mg/l . Interleukin-6 (IL-6) and Interleukin-2-receptor (IL-2-rec) were distinctly increased . Monoclonal antimyocardial antibodies were found . Leukocyte count never exceeded 9.8 G/l; however, transesophageal echocardiography validated a soft vegetation of the aortic valve . Antibiotic therapy was initiated with imipenem, gentamicin and vancomycin; clarithromycin was added after five days . Temperature normalized after 24 days . The c-reactive protein decreased from 389 mg/l to 6 mg/l, and the elevated cytokine levels decreased accordingly . Agranulocytosis or pancytopenia by ticlopidine through a toxic mechanism have been described, which are normally reversible within three weeks; there has not yet been a description of a missing leukocyte response in endocarditis as in this case report . This is a special situation with lack of or impeded immunological response, which limits the use of ticlopidine, especially since a therapeutic alternative with clopidogrel is available.

J Lipid Res, 2000 Oct, 41(10), 1680 - 8
Sphingolipids and cholesterol modulate membrane susceptibility to cytosolic phospholipase A(2); Klapisz E et al.; Modulation of cytosolic phospholipase A(2) (cPLA(2)) activity by sphingomyelin (SPH), ceramide (Cer), and cholesterol (Chol) was investigated in CHO-2B cells activated by the calcium ionophore A23187 and epinephrine . Chol depletion of CHO-2B cells by treatment with methyl-beta-cyclodextrin (5 mm) resulted in the inhibition of the release of arachidonic acid whereas the restoration of the level by Chol-loaded cyclodextrin relieved inhibition . Conversion of CHO-2B cellular SPH to Cer by Staphylococcus aureus sphingomyelinase enhanced endogenous cPLA(2) activation as well as uptake by cells of C2- and C6-ceramide analogs . These results were confirmed in vitro with purified human recombinant cPLA(2) acting on a model phospholipid substrate . The enzyme activity was inhibited by SPH but reactivated by Cer as well as by Chol added to glycerophospholipid liposomal substrates containing SPH . The results of this study, which combine in situ and in vivo experimental approaches, indicate that membrane microdomains enriched in SPH and Chol play a role in the modulation of the activity of cPLA2 and in arachidonic acid-derived mediator production.

Scand J Immunol, 2000 Oct, 52(4), 362 - 8
Neutrophil response of transgenic mice expressing human group IIA phospholipase A2 in bacterial infections; Laine VJ et al.; Group IIA phospholipase A2 (PLA2) is a newly recognized acute phase protein with marked antibacterial properties . We have shown previously that transgenic C57BL/6 J mice expressing human group IIA PLA2 (PLA2+ mice) are more resistant to bacterial infections than nontransgenic C57BL/6 J mice that, among mice, are unusual in that they lack the mouse analogue of group IIA PLA2 (PLA2- mice) . To elucidate the possible mechanisms involved in the host response of these mice in bacterial infection, peripheral inflammatory cell responses of PLA2+ and PLA2- mice were studied after i.p . administration of Escherichia coli, E . coli lipopolysaccharide or Staphylococcus aureus . Uninfected PLA2+ mice had higher numbers of lymphocytes and polymorphonuclear neutrophil leukocytes (PMNs) in their blood than PLA2- mice . In PLA2+ mice, the number of PMNs increased in peripheral blood in parallel with the concentration of group IIA PLA2 after the administration of bacteria, whereas these responses were not seen in PLA2- mice . High concentrations of group IIA PLA2 in PLA2+ mice may increase the synthesis of bioactive molecules, such as prostaglandins, which in turn may mobilize PMNs into circulation . Our results support the hypothesis that group IIA PLA2 is an important inflammatory mediator in bacterial infections.

Immunology, 2000 Oct, 101(2), 185 - 90
Staphylococcal enterotoxin B induces potent cytotoxic activity by intraepithelial lymphocytes; Roberts AI et al.; In food poisoning, Staphylococcus aureus secretes staphylococcal enterotoxin B (SEB), a superantigen that causes intense T-cell proliferation and cytotoxicity . The effects of SEB on lytic activity by human intestinal intraepithelial lymphocytes (IEL) were investigated . Jejunal IEL, from morbidly obese individuals undergoing gastric bypass operations, were tested for SEB-induced cytotoxicity against C1R B-lymphoblastoid cells, HT-29 adenocarcinoma cells, or CD1d-transfected cells using the 51Cr-release assay . Fas and Fas ligand expression were detected by immunofluorescence and flow cytometry and soluble ligand by enzyme-linked immunosorbent assay (ELISA) . In the presence of SEB, IEL became potently cytotoxic against C1R cells and interferon-gamma (IFN-gamma)-precultured HT-29 cells, causing 55+/-10% and 31+/-6% lysis, respectively, greater than that by phytohaemagglutinin (PHA)-, interleukin-2 (IL-2)-, or anti-T-cell receptor (TCR)-activated IEL . SEB-stimulated peripheral blood (PB) CD8+ T cells lysed similar numbers of C1R cells but fewer HT-29 cells (53+/-13% and 8+/-5%, respectively) . IEL killing of C1R cells involved interaction of major histocompatibility complex (MHC) class II with TCR, CD2 with CD58, and CD11a with CD54, and was perforin mediated . SEB-induced IEL lysis of HT-29 cells, in contrast, was caused by an unknown target cell structure, not MHC class II or CD1d, and resulted from a combination of perforin and Fas-mediated events . The potent cytotoxic activities of IEL promoted by SEB utilize two different mechanisms, depending on the surface receptors expressed by the target cells.

Int J Pharm, 2000 Aug 25, 204(1-2), 91 - 5
Penetration of topical and oral ofloxacin into the aqueous and vitreous humor of inflamed rabbit eyes; Ozturk F et al.; PURPOSE: This study aimed to investigate the penetration of topical and oral ofloxacin into aqueous humor and vitreous humor in post-traumatic endophthalmitis model in rabbits . METHODS: A standardized intraocular infection after penetrating injury was made in the right eyes of 16 rabbits . Intraocular infection was induced by intravitreal injection of a suspension of Staphylococcus aureus . The intact left eyes were maintained as controls . The animals were divided randomly into two groups . (1) In the topical group, two drops of ofloxacin 0.3% eyedrops were instilled to both eyes every 30 min for 4 h . (2) In the topical-oral group, two doses of 25 mg/kg of ofloxacin at 12-h intervals were given orally, then the protocol of the first group was applied . Aqueous and vitreous humor samples were taken 30 min after the last drop . Ofloxacin concentrations were measured by using HPLC . RESULTS: Mean aqueous levels of ofloxacin in control eyes were: 3.25 +/- 2.55 microg/ml in topical group . 4.58 +/- 5.39 microg/ml in topical-oral group . Mean aqueous levels in inflamed eyes were: 5.21 +/- 4.55 microg/ml in topical group, 10.34 +/- 8.88 microg/ml in topical-oral group . Mean vitreous levels of ofloxacin in control eyes were: 0.17 +/- 0.07 microg/ml in topical group, 1.30 +/- 1.23 microg/ml in topical-oral group . Mean vitreous levels in inflamed eyes were: 0.35 +/- 0.22 microg/ml in topical group, 3.48 +/- 2.69 microg/ml in topical-oral group . There was no significant difference among the groups (P > 0.05), however . CONCLUSIONS: The result of this study suggests that oral supplementation of ofloxacin to topical instillation increased the ocular levels of ofloxacin in the post-traumatic endophthalmitis model . Mean drug concentrations in aqueous and vitreous humors were above the 90% minimum inhibitory concentrations (MIC90) for most of the common microorganisms causing endophthalmitis in all eyes, except in the vitreous humors of the intact eyes instilled topically.

Artif Cells Blood Substit Immobil Biotechnol, 2000 Sep, 28(5), 415 - 28
Effects of liposome-encapsulated ciprofloxacin on phagocytosis, nitric oxide and intracellular killing of Staphylcoccus aureus by murine macrophages; Wong JP et al.; The effects of liposome-encapsulated ciprofloxacin on phagocytosis, nitric oxide production and intracellular killing of Staphylococcus aureus in murine macrophages were evaluated in this study . Mice were pretreated with three daily doses of liposome-encapsulated ciprofloxacin (45 mg/kg body weight/dose, intraperitoneal injection) . At day 3 post drug administration, peritoneal macrophages were harvested by peritoneal lavage, and the phagocytic activity of the macrophages was determined by a chemiluminescence assay using opsonized zymosan particles . The phagocytic activity was found to be 7-fold higher in the liposome-encapsulated ciprofloxacin-treated group when compared to the untreated control group . For S . aureus-infected macrophages incubated with liposomes containing subinhibitory concentrations of ciprofloxacin (0.05 to 0.25 microg/mL), there were significant increases (up to 40 microM) in the levels of nitrite (NO2-, an end product of nitric oxide synthesis), and concommitant decreases (2-3 log) in the intracellular concentrations of S . aureus . Peak nitrite levels (20-40 microM) were produced when concentrations of liposome-encapsulated ciprofloxacin used were 0.1 to 0.25 microg/mL . These results suggest that liposome-encapsulated ciprofloxacin may have profound effects on the immunological functions of macrophages.

Rev Med Chil, 2000 May, 128(5), 526 - 8
{Nocardia asteroides infection in a patient with systemic lupus erythematosus}; Mc-Nab P et al.; Nocardia asteroides infection are unusually observed in systemic Lupus erithematous (SLE) patients . They are generally associated to steroidal and immunosuppressive therapy . We report a 24 years old female with SLE diagnosed in 1994 who developed a severe preeclampsia in her first pregnancy requiring emergency caesarean section . Post partum acute renal failure and type IV lupus nephropathy were treated with hemodialysis, methylprednisolone, cyclophosphamide and prednisone . Three months later, while she was receiving the fourth cyclophosphamide dose, she presented with a pleuro pneumonia and occipital abscess, both caused by Nocardia asteroides . She was treated with cotrimoxazole + cefixime and pleural decortication was required . Five months later, she developed Meningitis caused by Nocardia asteroides and hydrocephalus . She was treated with ceftriaxone, vancomycin, cotrimoxazole and ventricular shunting procedure . Two months later, a retroperitoneal abscess was diagnosed and surgically drained but the patient died, due to a methicillin-resistant Staphylococcus aureus septicemia.

Braz J Infect Dis, 2000 Aug, 4(4), 197 - 203
Tissue pharmacokinetics of amoxicillin . An experimental design in rats; Baglie S et al.; Amoxicillin is used as the drug of first choice in many situations in medicine and dentistry, in spite of several reports regarding bacterial resistance . There is little data about the tissue concentration of this antimicrobial agent . Serum levels of amoxicillin have been evaluated in detail, but tissue levels have not . This study was carried out to determine the tissue concentration of amoxicillin during the first 10 h after administration . Four polyurethane sponges were implanted in the backs of 54 male rats . After 14 days, they received 40 mg/kg of po amoxicillin suspension . The animals were killed in groups of 6 at 15, 30, 60, 90, 120, 240, 360, 480 and 600 min after the administration . Serum, placed on paper discs, and granulomatous tissue were assayed by a microbiological method using Mueller Hinton agar inoculated with 108 cfu of Staphylococcus aureus (ATCC 25923) . After 18 h of incubation, the inhibition zones were measured . It was observed that the drug in the serum and the tissue reached higher concentrations than MIC and MBC within a period of 30 min and 8 h following administration . We conclude that this method can allow determination of antibiotic tissue concentration without the need for infecting the animal and, therefore, without the associated animal pain and suffering in presently used models.

Biochim Biophys Acta, 2000 Jun 15, 1479(1-2), 114 - 22
Engineering of substrate mimetics as novel-type substrates for glutamic acid-specific endopeptidases: design, synthesis, and application; Wehofsky N et al.; This account reports on the development and function of novel substrate mimetics as artificial substrates for Glu-specific endopeptidases . Firstly, in an empirical way, various aliphatic and aromatic analogs of the already established carboxymethyl thioester-substrate mimetics were designed from simple structure-function relationship studies . The specificity of the newly developed substrates for Staphylococcus aureus V8 protease-catalyzed reactions have been examined by steady-state hydrolysis kinetic studies . Additionally, these studies were expanded to the use of the equally Glu-specific endopeptidase from Bacillus licheniformis (BL-GSE) which can easily be purified from alcalase in high yields . Finally, the novel substrate mimetics were used as acyl donor components in BL-GSE- and V8 protease-catalyzed model acyl transfer reactions . The results clarify the newly developed substrate mimetics as efficient acyl donors as well as BL-GSE as an attractive alternative to V8 protease for enzymatic peptide synthesis.

Am J Ophthalmol, 2000 Jul, 130(1), 20 - 4
The effectiveness of a topical antibiotic irrigating solution in a model of staphylococcal keratitis after lamellar keratectomy; Rao SN et al.; PURPOSE: To create a model of Staphylococcus aureus keratitis after lamellar keratectomy; to assess the toxicity of an antibiotic irrigating solution on the corneal stromal bed; and to test the chemotherapeutic effectiveness of a topical antibiotic, both alone and with an antibiotic-containing irrigating solution in preventing S . aureus keratitis after lamellar keratectomy . METHODS: The right eye of each of 38 rabbits were used in this study . In 18 eyes, a lamellar flap was created with a microkeratome, and an inoculum of S . aureus (either 1,000, 5,000, or 50,000 CFUs) was instilled under each flap; the eyes were examined for signs of infection and inflammation at 24 and 48 hours . In another five eyes, a lamellar flap was created in the same manner and the stromal bed was irrigated with 0.3% ofloxacin; the eyes were assessed for ocular inflammatory changes and evidence of crystalline deposits . Finally, in each of 15 additional eyes, 1,000 CFUs of S . aureus were instilled under a lamellar flap to create experimental infectious keratitis . The keratitis was treated according to three regimens: irrigation of the stromal bed with sterile balanced salt solution; irrigation of the stromal bed with 0.3% ofloxacin, followed by application of topical ofloxacin four times a day; application of topical ofloxacin only, four times a day . Eyes were examined for infection and ocular inflammatory changes at 24 and 48 hours . RESULTS: Staphylococcus aureus keratitis can consistently be produced under the stromal flap by inoculation of relatively few organisms . Irrigation of the stromal bed with commercial-strength topical ofloxacin does not appear to be toxic to the stromal bed, with no evidence of crystalline precipitates of the antibiotic . In our model of infectious keratitis after lamellar keratectomy, both topical ofloxacin alone and the combination of topical ofloxacin and irrigation of the stromal bed with 0.3% ofloxacin were effective at preventing S . aureus keratitis . However, the combined treatment of antibiotic irrigation plus topical antibiotic was more effective at preventing inflammation than topical ofloxacin alone.CONCLUSIONS: In this model of S . aureus keratitis after lamellar keratectomy, irrigation of the stromal bed with antibiotic plus topical antibiotic appears to be both safe and effective for preventing infection.

J Bacteriol, 2000 Oct, 182(20), 5893 - 7
SarA represses agr operon expression in a purified in vitro Staphylococcus aureus transcription system; Chakrabarti SK et al.; Mutation and genetic complementation studies suggested that two chromosomal loci, agr and sar, are involved in the upregulation of several exotoxin genes and the downregulation of a number of surface protein genes in a growth phase-dependent manner in Staphylococcus aureus . We purified recombinant T7-tagged SarA from Escherichia coli and determined its effect on transcription from several S . aureus promoters by using purified RNA polymerase reconstituted with either sigma(A) or sigma(B) from S . aureus . Of the seven sigma(A)-dependent promoters that we tested, SarA repressed transcription from agrP2, agrP3, cna, sarP1, and sea promoters and did not affect sec and znt promoters . Furthermore, SarA had no effect on transcription from the sigma(B)-dependent sarP3 promoter . In vitro experimental data presented in this report suggest that SarA expression is autoregulated.

J Bacteriol, 2000 Oct, 182(20), 5721 - 9
Population studies of methicillin-resistant and -sensitive Staphylococcus aureus strains reveal a lack of variability in the agrD gene, encoding a staphylococcal autoinducer peptide; van Leeuwen W et al.; The virulence of Staphylococcus aureus is controlled by the accessory gene regulator (agr) system, including an extracellular inducer encoded by agrD . Variable agr PCR restriction fragment length polymorphism (RFLP) patterns of unique S . aureus strains (n = 192) were determined for a region comprising agrD and parts of the neighboring agrC and agrB genes . Twelve unique RFLP patterns were identified among S . aureus strains in general; these patterns were further specified by sequencing . All sequences could be catalogued in the three current agr groups . A major proportion of the S . aureus strains belong to agr group 1, whereas only 6% of the methicillin-susceptible S . aureus strains and 5% of the methicillin-resistant S . aureus strains belong to agr groups 2 and 3, respectively . The homology between groups varied from 75 to 80%, and within groups it varied from 96 to 100% . Different levels of sequence variability were observed in the different agr genes . agr-related bacterial interference among colonizing S . aureus strains in the noses of persistent and intermittent human carriers was studied . S . aureus strains belonging to different agr groups were encountered in the same individual . This may suggest that the activity of the agrD gene product does not define colonization dynamics, which is further substantiated by the rarity of agr group 2 and 3 strains.

J Dairy Sci, 2000 Sep, 83(9), 2004 - 7
Evaluation of an experimental milking pulsation system for effects on milking and udder health; Wilson DJ et al.; This study was to test whether cows milked by an experimental pulsation method differed from cows milked with conventional pulsation milking in somatic cell count (SCC), intramammary infections (IMI) defined by milk bacteriological culture results, teat end condition, or milk flow rate . The study design was a 1-yr trial with a completely randomized block crossover . Holstein cows were blocked into 15 pairs of contemporaries . Both cows from each pair were milked with experimental pulsation and with conventional pulsation for 6 mo, in reverse order from each other . The SCC (217,000/ml) of experimentally milked cows was not significantly different from SCC of conventionally milked cows (175,000/ml) . Mean milk flow rate was 5.2 lb/min (2.4 kg/min) for experimentally milked cows and 5.3 lb/min (2.4 kg/min) for conventionally milked cows, not significantly different . Differences among the experimentally and conventionally milked cows, respectively, in new (13.5 and 12.7%), chronic (12.9 and 8.9%), and negative (73.6 and 78.4%) quarter culture results were not significant . New IMI per 100 d of lactation were 1.50 and 1.46, and chronic IMI per 100 d were 1.85 and 1.27, for experimentally and conventionally milked cows, respectively . These IMI rates were not significantly different between pulsation types . There were more new Staphylococcus aureus IMI associated with conventional pulsation, but overall cases of Staph . aureus were similar between the two types of pulsation . Teat end scores for the experimentally and conventionally milked cows, respectively, were good (6.5 and 11.7%), intermediate (68.2 and 66.9%), and poor (25.3 and 21.4%), not significantly different . These results support previous studies, which have found that except for complete failure of pulsation, differences in pulsation characteristics apparently have little effect on milking and udder health.

J Dairy Sci, 2000 Sep, 83(9), 1981 - 8
Protection against Staphylococcus aureus mastitis in dairy cows using a bismuth-based teat seal containing the bacteriocin, lacticin 3147; Twomey DP et al.; We assessed the effectiveness of a novel dry cow treatment containing lacticin 3147 using deliberate challenge studies in lactating cows . Infection-free quarters of lactating cows were infused with Teat seal (Cross Vetpharm Group, Ltd., Dublin, Ireland) combined with the food-grade bacteriocin, lacticin 3147 . Natural infection of the teat was simulated by deliberately introducing Staphylococcus aureus into the teat duct and teat sinus . Relative to control quarters, teat seal plus lacticin 3147 reduced the number of teats shedding viable cells when an inoculum of either approximately 1.7 x 10(3) or approximately 6.8 x 10(3) cfu per teat was used . In addition, the numbers of challenge organisms in those teats from which S . aureus was subsequently recovered were also reduced . However, when the concentration of bacteriocin in the teat seal formulation was reduced by approximately 50%, the number of teats shedding S . aureus cells was not reduced . These data indicate the potential for lacticin 3147 to prevent staphylococcal mastitis infections when a sufficient concentration of the bacteriocin is present . This study also highlights the application of a lactating-cow model to assess the effectiveness of antimicrobial intramammary products on mastitic cell populations.

J Am Acad Dermatol, 2000 Oct, 43(4 Pt 2), S57 - S69
Dermatopharmacology of ciclopirox nail lacquer topical solution 8% in the treatment of onychomycosis; Bohn M et al.; Ciclopirox is a synthetic hydroxypyridone antifungal agent . In contrast to the azoles, glucuronidation is the main metabolic pathway of ciclopirox; therefore interactions with drugs metabolized via the cytochrome P(450) system are unlikely . Ciclopirox is also distinct from the common systemic agents, which interfere with sterol biosynthesis . In fact, ciclopirox chelates trivalent cations (such as Fe(3+)), inhibits metal-dependent enzymes that are responsible for degradation of toxic metabolites in the fungal cells, and targets diverse metabolic (eg, respiratory) and energy producing processes in microbial cells . Ciclopirox is a broad spectrum antimicrobial with activity against all the usual dermatophytes as well as yeast and nondermatophyte molds . It has demonstrated activity against gram positive and negative bacteria, including resistant strains of Staphylococcus aureus . Ciclopirox exhibits fungal inhibitory activity (minimum inhibitory concentration < 4 microg/mL for dermatophytes) as well as fungicidal activity; to date resistance to the drug has not been identified . Ciclopirox has been formulated in a nail lacquer delivery system . After evaporation of volatile solvents in the lacquer, the concentration of ciclopirox in the remaining lacquer film reaches approximately 35%, providing a high concentration gradient for penetration into the nail . Radiolabel data demonstrate penetration into infected nails after only 1 application of the lacquer . Ciclopirox nail lacquer is a topical product that provides an active fungicidal agent in a delivery system capable of promoting nail penetration . With repeated applications, the antifungal agent is homogeneously distributed through all layers of the toenail achieving concentrations of ciclopirox in excess of inhibitory and fungicidal concentrations for most pathogens . Although ciclopirox readily penetrates nails, very low levels of ciclopirox are recoverable systemically, even after chronic use . Ciclopirox nail lacquer 8% is a topical product that provides an active fungicidal agent in a delivery system capable of penetrating nails.

Infect Control Hosp Epidemiol, 2000 Sep, 21(9), 603 - 5
Prevalence of nasal colonization with methicillin-resistant Staphylococcus aureus in selected patient populations; Price MF et al.; Methicillin-resistant Staphylococcus aureus nasal colonization was investigated in patients arriving for elective cardiovascular surgery, renal patients admitted for arteriovenous graft surgery, and patients transferred to our hospital from other institutions . Renal patients were significantly more likely to be colonized and represent a potential source of MRSA to our institution.

Infect Control Hosp Epidemiol, 2000 Sep, 21(9), 583 - 7
Comparison of systematic versus selective screening for methicillin-resistant Staphylococcus aureus carriage in a high-risk dermatology ward; Girou E et al.; OBJECTIVE: To compare two strategies for screening methicillin-resistant Staphylococcus aureus (MRSA) carriers in a high-risk dermatology ward: systematic screening of all admitted patients versus selective screening of patients at risk . DESIGN: The two strategies were applied prospectively during two consecutive periods . In period A (8.5 months), only patients transferred from other wards, or with a history of prior hospitalization, or presenting chronic wounds or disease with denuded skin were considered at high risk of MRSA carriage and sampled . In period B (7.5 months), all admitted patients were systematically screened . End-points were the number of patients having a MRSA-positive screening sample on admission during period B and having none of the risk factors used in period A, the rate of imported MRSA cases, and the rate of acquired cases . SETTING: A 1,032-bed university hospital with a 19-bed inpatient dermatology ward, a referral center for toxic epidermal necrolysis and severe extensive dermatoses . PATIENTS: The study included 729 dermatology inpatients (370 in period A and 359 in period B) . RESULTS: During period A, screening samples were obtained on admission for 30% of patients (77% of the patients at risk) and identified 25 MRSA carriers . During period B, 90.5% of admitted patients were screened, and 26 MRSA carriers were detected on admission; all of these patients belonged to at least one predefined category at risk for carriage . Overall rates of imported and acquired cases were similar between the two periods (6.8% vs 7.5%, and 2.9% vs 2.4%, respectively) . CONCLUSIONS: A screening strategy targeted to patients at risk of harboring MRSA has similar sensitivity and is more cost-effective than a strategy of systematic screening to identify MRSA carriers on admission.

Surg Endosc, 2000 Sep, 14(9), 812 - 6
The influence of laparoscopic surgery on postoperative polymorphonuclear leukocyte function; Sietses C et al.; BACKGROUND: Laparoscopic surgery is thought to result in a better preservation of patients' immunological defenses . Polymorphonuclear leukocytes (PMN) are the most important effector cells in the elimination of pathogenic microorganisms . Because little is known about their function after laparoscopic surgery, we studied PMN phagocytosis, antigen expression, and oxygen radical production . METHODS: In this study, 17 patients scheduled for Nissen fundoplication were randomly assigned to undergo either a laparoscopic or conventional procedure . To study phagocytic capacity, PMN were incubated with fluorescein isothiocyanate (FITC)-labeled Staphylococcus aureus . Plasma opsonic capacity was measured by comparing PMN phagocytosis in the presence of patients' own plasma with phagocytosis in the presence of control plasma . Cellular activation was measured by the expression of various cell surface markers and by assessment of PMA-stimulated oxidative burst . RESULTS: Phagocytosis by PMN in the presence of patients' plasma was significantly lower 2 h after the conventional operation . No decrease in phagocytosis was observed when control plasma was used, indicating a decreased opsonic capacity of plasma after conventional surgery . No changes were observed after laparoscopic surgery . Furthermore, CD11b expression was significantly lower after the laparoscopic approach, indicating a blunted cellular activation . A significantly lower PMA-stimulated oxidative burst further confirmed the tempered stimulation after laparoscopic surgery . CONCLUSIONS: Laparoscopic surgery results in a preservation of the plasma opsonic capacity, and thereby the ability of PMN to phagocytose bacteria . Moreover, the postoperative cellular activation is reduced . The preserved phagocytosis and the blunted activation may prevent the development of postoperative infectious complications.

J Assoc Physicians India, 1999 Jun, 47(6), 619 - 21
Spontaneous bacterial peritonitis in liver cirrhosis with ascites; Jain AP et al.; OBJECTIVE: The study was designed to elucidate the correlation of spontaneous bacterial peritonitis (SBP) with aetiology of liver cirrhosis, overall mortality, ascitic fluid and systemic microbial infections . METHODS: Sixty three patients with cirrhosis of the liver were included in this study . These patients were diagnosed on the basis of clinical evaluation, biochemical investigation, ultrasonography, ascitic fluid examination for protein, cells, pH, and bacterial culture . RESULTS: SBP developed in 22 (34.92%) patients of cirrhosis . Culture positive SBP was present in 18 (81.81%) and culture negative neutrocytic ascitis (CNNA) in 4 (18.18%) . In the culture positive group, 14 (77.7%) patients had monomicrobial bacterascites (MNB), the commonest organism being coagulase positive Staphylococcus aureus eight (44.44%) followed by E . coli (22.22%) . Only 4 (22.22%) had infection by more than one organism . Direct bed side inoculation of ascitic fluid into blood culture bottle was a better method for bacterial yield than the conventional method of ascitic fluid culture (81.8% vs . 18.2%) . Only 22.8% patients with SBP had ascitic fluid protein less than 1 gm%, ascitic fluid pH < 7.3 and polymorphonuclear cell count > 250/cmm . CONCLUSION: Spontaneous bacterial peritonitis is common complication in Child Pugh class C cirrhosis . Alcoholic cirrhosis with SBP carries high mortality than their non-alcoholic group . The most common organisms isolated were coagulase positive Staphylococcus aureus followed by E . coli.

Kyobu Geka, 2000 Sep, 53(10), 867 - 9
{A successfully repaired case of methicillin-resistant Staphylococcus aureus infective endocarditis in a girl with VSD}; Nakashima K et al.; We report a successful case of active infective endocarditis due to Methicilin-Resistant Staphylococcus aureus (MRSA) . A 2-year-old girl who had a ventricular septal defect (VSD) complained of persistent fever . Echocardiography showeda large vegetation on the tricuspid valve and a small VSD . She underwent vegetectomy, tricuspid valvoplasty and direct closure of VSD . Vancomycin treatment was also effective to abolish infection . She was discharged without any complication.

Mol Microbiol, 2000 Sep, 37(6), 1372 - 8
Electrophysiological evidence for heptameric stoichiometry of ion channels formed by Staphylococcus aureus alpha-toxin in planar lipid bilayers; Krasilnikov OV et al.; Staphylococcal alpha-toxin forms homo-oligomeric channels in lipid bilayers and cell membranes . Here, we report that electrophysiological monitoring of single-channel function using a derivatized cysteine substitution mutant allows accurate determination of the subunit stoichiometry of the oligomer in situ . The electrophysiological phenotype of channels formed in planar lipid bilayers with the cysteine replacement mutant I7C is equal to that of the wild type . When pores were formed with I7C, alterations of several channel properties were observed upon modification with SH reagents . Decreases in conductance then occurred that were seen only as negative voltage was applied . At the level of single channels, these were manifest as stepwise changes in conductance, each step most probably reflecting modification of a single SH group within the oligomer . Because seven steps were observed, the functional channel formed by alpha-toxin in planar lipid membranes is a heptamer.

Immunol Lett, 2000 Oct 3, 74(2), 111 - 5
Ehrlich ascites tumour unbalances splenic cell populations and reduces responsiveness of T cells to Staphylococcus aureus enterotoxin B stimulation; Segura JA et al.; Tumours must avoid host immune response to survive and proliferate; to achieve this purpose, tumours interact with cells of the immune system by means of tumour secreted factors . The alterations of splenic cell populations in mice bearing the Ehrlich ascites tumour have been studied . A rapid and acute response was observed, characterized by a decrease in both CD4 and CD8 T cells, and a transient increase in the number of B cells, which peaked 2 days after tumour inoculation . An increase in macrophage population and in the homing antigen CD18 was also detected . In vitro incubations of splenic cells with the Staphylococcus aureus enterotoxin B (SEB) showed that tumour induces a state of reduced responsiveness to stimulation of T cells, mainly affecting CD8 T cells, and a diminished IFN-gamma expression.

FEBS Lett, 2000 Sep 15, 481(2), 169 - 76
Packaging of up to 240 subunits of a 17 kDa nuclease into the interior of recombinant hepatitis B virus capsids; Beterams G et al.; The icosahedral nucleocapsid of hepatitis B virus (HBV) consists of multiple subunits of a single 183 amino acids (aa) core protein encasing the viral genome . However, recombinant core protein alone also forms capsid-like particles . We have recently shown that a 238 aa protein centrally inserted into the core protein can be displayed on the particle surface . Here we demonstrate that replacement of the C-terminal basic domain by the 17 kDa Staphylococcus aureus nuclease also yields particles but that in these the foreign domains are located in the interior . The packaged nuclease is enzymatically active, and the chimeric protein forms mosaic particles with the wild-type core protein . Hence the HBV capsid is useful as a molecular platform which, dependent on the fusion site, allows foreign protein domains to either be packaged into or be exposed on the exterior of the particle . These results are of relevance for the use of the HBV capsid as a vaccine carrier, and as a target for antiviral therapy.

J Ethnopharmacol, 2000 Oct, 72(3), 483 - 8
Phytochemical flavones isolated from Scutellaria barbata and antibacterial activity against methicillin-resistant Staphylococcus aureus; Sato Y et al.; A crude extract prepared from Scutellaria barbata D . Don (Lamiaceae) was analyzed in the effort to discover antibacterial compounds against high-level strains of methicillin-resistant Staphylococcus aureus (MRSA) . Apigenin and luteolin were isolated from the plant as active constituents against the bacteria . These flavonoid congeners were selectively toxic to S . aureus, including the MRSA and methicillin-sensitive S . aureus strains.

Occup Med (Lond), 2000 Aug, 50(6), 395 - 7
Methicillin-resistant Staphylococcus aureus and multidrug resistant tuberculosis: Part 2; Patel D et al.; Drug resistant tuberculosis has been recognized since chemotherapy first became available . However, drug resistance has increased in many countries, and recently strains resistant to both rifampicin and isoniazid (multidrug resistant tuberculosis) have emerged . This review discusses the epidemiology of multidrug resistant tuberculosis (MDRTB), and the control of MDRTB in healthcare facilities . Relevant papers for this review were identified by a systematic literature search on Medline . MDRTB is already established world-wide, and although the overall problem of resistance remains low in the UK, it is of significant clinical importance due to its high case-fatality, higher transmission risk, and complex treatment . The key elements of MDRTB control are prompt recognition, confirmation and treatment of cases, and the institution of strict infection control procedures to reduce the airborne spread of infection from infectious patients to others . This review emphasizes the importance of a multidisciplinary approach to management, with liaison between tuberculosis physicians, the microbiology department, infection control team, consultant in communicable disease, and occupational health.

Occup Med (Lond), 2000 Aug, 50(6), 392 - 4
Methicillin-resistant Staphylococcus aureus and multidrug resistant tuberculosis: Part 1; Patel D et al.; The first of these articles reviews the epidemiology of MRSA and its clinical importance in a healthcare setting . The methods of controlling the spread of hospital acquired MRSA are discussed with an emphasis on the role of screening staff for MRSA . Relevant papers for the review were identified by a systematic literature search on Medline . The prevalence of MRSA is increasing in the United Kingdom, as is the prevalence of 'epidemic' MRSA strains . Several countries have recently reported cases of Staphylococcus aureus with intermediate-level resistance to vancomycin . The key measures to minimizing hospital-acquired MRSA are stringent infection control programmes and strict antibiotic policies . Staff screening should only be undertaken after a detailed risk assessment of the local situation has been made by the occupational health and infection control teams . Priority should be given to high-risk areas of a hospital where MRSA is endemic.

J Clin Ultrasound, 2000 Oct, 28(8), 414 - 6
Radial artery mycotic pseudoaneurysm: an unusual complication of catheterization; Tsao JW et al.; Radial artery pseudoaneurysms are rare, and those that become infected are rarer still . We present the case of a patient who developed a radial artery pseudoaneurysm as a late complication of arterial catheterization . Blood cultures were positive for Staphylococcus aureus, and a pulsatile mass, with associated tissue necrosis, was palpable over the radial artery . The diagnosis was confirmed by gray-scale and color Doppler sonography, which showed a partially thrombosed pseudoaneurysm and turbulent flow in the pseudoaneurysm and native artery .

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