Radiology, 1998 Jul, 208(1), 159 - 65 Percutaneous drainage of fluid collections in the extremities; Wu HP et al.; PURPOSE: To analyze the results of percutaneous drainage of fluid collections in the extremities . MATERIALS AND METHODS: From 1990-1997, 28 patients aged 14-90 years underwent percutaneous drainage of 33 fluid collections in the extremities; two patients underwent multiple drainages . Fluid collections were in the hip-groin area (n = 16), thighs (n = 6), buttocks (n = 6), knees (n = 3), calf (n = 1), and axilla (n = 1) . Three intraarticular collections were included . The patients who had undergone prior procedures were eight who had undergone surgical drainage, 10 who had undergone needle aspiration, and one who had undergone surgical debridement . The two most common guidance methods of catheter placement were ultrasound localization and fluoroscopy . RESULTS: The average drainage duration was 18.2 days (range, 1-93 days) . The estimated cavity sizes were 4-733 cm3 . Purulent fluid was drained in 13 patients . Staphylococcus aureus was the most commonly identified organism (n = 9) . Nine patients had postoperative lymphoceles; five of these patients underwent sclerotherapy . Two (7%) patients had two complications, one of which was major . Failure occurred in four (16%) of 25 patients; two needed repeat drainage for recurrence, and two needed subsequent surgery . Success could not be determined in three patients who were lost to follow-up . CONCLUSION: Percutaneous drainage of fluid collections in the extremities is an effective alternative to open-incision drainage in inpatients and outpatients. J Am Soc Nephrol, 1998 Jul, 9(7), 1314 - 7 Silent infection in clotted hemodialysis access grafts; Ayus JC et al.; Thrombotic and infectious complications are frequent causes of hemodialysis vascular access failure and contribute considerably to the cost of care for chronic hemodialysis patients . Although there is clear indication for removal of patent grafts in unresolved bacteremia, there are no guidelines for the management of clotted nonfunctioning grafts . To evaluate for the existence and clinical relevance of silent infection in clotted nonfunctioning hemodialysis grafts, a study was conducted with a series of 20 hemodialysis patients who presented with fever (15 patients), or fever and clinical signs of sepsis (five patients), in whom the source of infection was not immediately localized to any organ system . Comparison was made with 21 asymptomatic patients with clotted grafts who served as control subjects . All patients and control subjects came from a pool of 115 chronic hemodialysis patients in an outpatient hemodialysis unit in the Houston metropolitan area, who were on hemodialysis for a period of time ranging from 3 to 15 yr . Indium scans were performed, followed by removal of the clotted grafts in all patients and control subjects . Bacterial cultures of the recovered surgical material and blood were done concomitantly in all study participants . Indium scans showed positive uptake in or around the clotted grafts in all of the patients and in 15 of the control subjects . Purulent material was found in the grafts in all patients and in 13 of 15 indium scan-positive control subjects . When positive, blood culture pathogens were identical to those cultured from the graft material in all instances . The predominant pathogens were Staphylococcus aureus, followed by Staphylococcus epidermidis . There was no evidence of graft infection in the control subjects if indium scan was negative . Chart review dating back to the start of dialysis revealed five past infectious episodes in the patient group, compared with four in the control group . These findings suggest that clotted nonfunctioning grafts are frequent harbingers of infection . They should be suspected as the source of infection in every hemodialysis patient that presents with fever, even in the absence of clinical signs of graft site infection. Jpn J Antibiot, 1998 Apr, 51(4), 272 - 80 {Increase of non-amidated muropeptides in the cell wall of vancomycin-resistant Staphylococcus aureus (VRSA) strain Mu50}; Hanaki H et al.; The mechanism of resistance was studied with vancomycin-resistant Staphylococcus aureus (VRSA) strain Mu50 . It was demonstrated that the incorporation of 14C-N-acetylglucosamine into the cell wall of Mu50 was not suppressed in the presence of 8 microliters/ml of vacomycin, whereas it was completely suppressed in vancomycin-susceptible strains FDA209P and H-1 . Increased binding of vancomycin to the wall of Mu50 was observed compared to the control strains: 1.7 x 10(16) (Mu50), 6.1 x 10(15) (209P), and 6.7 x 10(15) (H-1) vancomycin molecules/mg cell wall, respectively . Remarkable proportion of the cell-wall component muropeptides were non-amidated in the cell wall of Mu50 . In concordance with this phenomena, peptidoglycan cross-linkage decreased strikingly in the Mu50 strain . Free D-Ala-D-Ala residues at the end of muropeptides in the pre-existing cell wall generated by decreased cross-linkage seems to account for increased vancomycin binding . The increase of vancomycin-resistance level is presumably caused by sequestration of vancomycin molecules from primary target point on cell membrane . It was considered that at least two phenotypic changes are required for the vancomycin resistance in the Mu50 strain . First, as we have described previously, is the activated cell wall synthesis, and second, the reduction of cross-linkage of peptidoglycan by production of non-amidated muropeptide precursors. J Biochem (Tokyo), 1998 Jul, 124(1), 163 - 70 Conformation, filament assembly, and activity of single-headed smooth muscle myosin; Konishi K et al.; Single-headed myosin was prepared by digestion of porcine aorta smooth muscle myosin with Staphylococcus aureus V8 protease in the presence of actin . The single-headed myosin preparation contained intact light chains, a rod fragment of a heavy chain, and a heavy chain of which only a minor fraction contained a nick in the head segment . Below 0.2 M NaCl, the single-headed myosin showed a decrease in Ca2+-ATPase activity and an increase in the elution time on gel filtration HPLC in a phosphorylation-dependent manner, indicating a phosphorylation-dependent conformational transition between the extended and folded forms . These conformations were confirmed by electron microscopic observation of rotary-shadowed samples of single-headed myosin . However, the conformational transition of single-headed myosin occurred in a narrower range with lower salt concentrations than that of double-headed myosin . The filament assembly of single-headed myosin was thus facilitated and phosphorylation-independent . The single-headed myosin also showed high actin-activated ATPase activity independent of phosphorylation . These results indicate that the two-headed structure of smooth muscle myosin is not essential for the conformational transition, but is required for the phosphorylation-dependent regulation of enzymatic activity and filament assembly. Commun Dis Public Health, 1998 Jun, 1(2), 126 - 7 Molecular characterisation of methicillin resistant Staphylococcus aureus; Walker J et al.; Finer discrimination between strains of methicillin resistant Staphylococcus aureus (MRSA) than phage typing can provide is needed to identify and characterise spread of infection in outbreaks . This study compares three molecular methods with each other and with phage typing . Pulsed field gel electrophoresis provides the greatest discrimination, but finer discrimination is obtainable by combining methods. Oral Dis, 1997 Dec, 3(4), 262 - 71 Characteristics and responses of EBV immortalized B cells from periodontal disease patients; Celenligil H et al.; OBJECTIVE: This study was designed to examine human B cell responses to Actinobacillus actinomycetemcomitans (Aa) . The general hypothesis to be tested was that Epstein-Barr virus (EBV) immortalized B cells could be used to investigate variations in B cell responsiveness of periodontitis patients to periodontal pathogens, and that B cells derived from the peripheral blood of periodontal disease patients infected with Aa demonstrate differences in in vitro activities compared to periodontally healthy subjects . DESIGN: EBV-transformed B cell lines were used to analyze immunoglobulin and Aa-specific antibody responses, as well as to determine the frequencies of cells producing immunoglobulin (Ig) of a specific isotype and detect clones secreting antibodies specific for Aa . Lymphoblastoid cells lines (LCL) were derived by clonal transformation of peripheral blood lymphocytes from 10 Aa-infected patients with adult periodontitis (Aa-AP) and seven normal subjects . METHODS: The B cells were incubated in Aa-coated polystyrene plates to separate adherent and non-adherent cells, and stimulate the cells with the whole bacteria . In addition, the B cells were stimulated with Aa LPS, E . coli LPS, or the polyclonal B cell activators (PBAs), pokeweed mitogen (PWM) and Staphylococcus aureus protein A (SpA) . Both adherent and non-adherent cell populations were cultured for up to 15 days . MAIN OUTCOME MEASURE: Total immunoglobulins (Igs) and antibody (IgG, IgA, IgM) levels to Aa in the culture supernatants were assessed using an ELISA . The distribution of IgG, IgA, IgM and Aa-specific antibody producing cells was analyzed by a double immunoenzymatic staining technique . RESULTS: IgM levels produced by the LCLs were significantly increased vs IgG and IgA (P < 0.001) . Three days after Aa stimulation, a marked increase in the level of total Igs and Aa-specific antibody was observed in adherent cells from Aa-AP (P < 0.05-0.03) . Aa-specific antibody levels were significantly higher in the supernatants from Aa-AP vs normals throughout the culture interval (P < 0.03) . There was also a significant increase in Aa-specific antibody levels after stimulation with Aa LPS or E . coli LPS (P < 0.05), whereas PWM and SpA had no significant effect on antibody to Aa . There was a predominance of IgM cells compared to IgG and IgA isotypes (P < 0.04) in LCLs from Aa-infected patients . After stimulation with Aa, a significant increase in the number of IgA (111%) and IgG (48%) secreting cells was observed, concomitant with a 74% decrease in the Ig-negative cell population . Total Aa+ cells increased significantly after stimulation (P < 0.001), predominated by Aa-specific IgG and IgM antibody producing cells . CONCLUSIONS: These results showed that LCLs from Aa-infected patients were polyclonal with respect to isotype distribution . Further stimulation with Aa revealed a shift to cytoplasmic IgG and IgA expression, as well as increases in the Aa-specific B cell population . In contrast, the PBAs stimulated the LCLs to synthesize primarily IgM . Additionally, the findings indicated that: (1) without T cells, polyclonal activation of B cells may lead to elevated Aa-specific B cell populations; and (2) the presence of previously sensitized B cells is required to exert an antigen specific antibody response in the LCL . We conclude that secondary activation of primed B cells by oral bacteria or their products in advanced periodontal lesions may contribute to the local accumulation of significant numbers of Ig-producing cells . This report also suggested that EBV-mediated transformation can be used to probe B cell-bacterial interactions in studies of periodontitis. Kansenshogaku Zasshi, 1998 May, 72(5), 536 - 42 {Difference of host response in identical toxin-produced Staphylococcus aureus-injected mice}; Onogawa T et al.; Biological activities of two strains of Staphylococcus aureus (S . aureus), KU-1-06-37 and KU-1-12-44, which produce enterotoxin type C, TSST-1 and alpha-toxin were examined using Std:ddY strain mice . These two strains were found to be different in lethality, ratio of weight loss, induction of leukopenia, adhesion to surrounding organs and clearance period of bacterial cells from the liver, kidney and spleen within 24 hrs after intraperitoneal injection in the mice . All of them were weak or fast in KU-1-12-44 injected mice . Serum amyloid A on all the KU-1-06-37 and KU-1-12-44 injected mice rose within 5 hr to 18 hr . However, this concentration of KU-1-12-44 injected mice was about 40% lower compared with that of KU-1-06-37 injected mice at 21 hr . On the other hand, ability of bacterial adhesion to established cell lines, Vero and HeLa cells, was tested in vitro . Percentage adhesion of KU-1-06-37 was high to both cells, but that of KU-1-12-44 was high to Vero cells and was low to HeLa cells . Adhesion of KU-1-06-37 to HeLa cells that were treated with lipoteichoic acid was about 40% inhibition compared with untreated cells, although that of KU-1-12-44 to them was inhibited only 9% . As the results, identical toxin-produced KU-1-06-37 and KU-1-12-44 showed different biological activities in vivo and in vitro . Not only toxin production but also adhesion to cells or organs in mice may contribute to S . aureus virulence to the host. J Neurosci Nurs, 1998 Apr, 30(2), 105 - 9, 114-5 Spinal cervical infection: a case report and current update; Saban KL et al.; Cervical spine infection is a term used to encompass osteomyelitis, discitis and epidural abscess . Most cases are caused by Staphylococcus aureus but other organisms have been isolated . The most frequent source is hematogenous spread from a nearby or distant source . Diagnosis is often confusing . The most common symptom is worsening back or neck pain that increases with movement . Patients may have motor or sensory changes if there is compression of the nerve roots or spinal cord . If the condition is not treated promptly, it may progress to irreversible neurologic deficit . Positive blood cultures and an elevated erythrocyte sedimentation rate (ESR) may be seen . Radiologic findings may include a paravertebral swelling, a destruction of the vertebral end plates and adjacent portions of the bodies and disc space and the presence of an epidural mass . Treatment includes radical surgical intervention for debridement and decompression to stabilize the spine in conjunction with 8-12 weeks of intravenous antibiotics . Closed continuous local antibiotic irrigation with a gravity control outflow system has been used. J Bacteriol, 1998 Jul, 180(13), 3477 - 9 Characterization of the earliest known Staphylococcus aureus plasmid encoding a multidrug efflux system; Paulsen IT et al.; The staphylococcal qacB-encoding multidrug resistance plasmid pSK156, isolated from a clinical strain dating from 1951, was characterized . Comparison of the regions flanking qacB with other qacA- and qacB-encoding plasmids provided insights into the evolution and dissemination of these multidrug efflux genes and led to the detection of the earliest known copy of the insertion sequence IS257. Retina, 1998, 18(2), 130 - 5 Timing of dexamethasone treatment in experimental Staphylococcus aureus endophthalmitis; Yoshizumi MO et al.; PURPOSE: This study sought to determine whether intravitreal dexamethasone with vancomycin preserves retinal function in eyes with experimental Staphylococcus aureus endophthalmitis better than intravitreal vancomycin alone . METHODS: Twenty-four rabbits received intravitreal injections in both eyes with S . aureus . Right eyes were treated with intravitreal dexamethasone plus vancomycin and left eyes were treated with vancomycin alone at 24, 36, 48, or 72 hours after inoculation . Evaluation was performed by slit-lamp biomicroscopy, indirect ophthalmoscopy, and electroretinogram . Vitreous humor cultures and histopathologic examinations were performed on the eyes after the rabbits were killed . RESULTS: The combination of intravitreal dexamethasone and vancomycin resulted in significantly less inflammation than vancomycin alone at 24 and 36 hours after inoculation, but electroretinograms showed significantly better preservation only at 36 hours after bacterial inoculation . Viable bacteria were cultured from eyes treated 48 and 72 hours after inoculation . CONCLUSION: Intravitreal dexamethasone was found to be beneficial by electroretinography when administered 36 hours after infection . In the authors' model, a single intravitreal injection of vancomycin with or without the addition of dexamethasone was insufficient to sterilize eyes 48 and 72 hours after bacterial inoculation. J Biomed Mater Res, 1998 Jul, 41(1), 142 - 53 Tissue reactions to bacteria-challenged implantable leads with enhanced infection resistance; van Wachem PB et al.; Tissue reactions to implantable pacemaker leads were investigated in an early infection model in rabbits . Both standard leads and surface-modified leads were used . The surface modification technique was applied to achieve controlled release of the antibiotic gentamicin . The insulating polyurethane tubing material of the leads was provided with an acrylic acid/acrylamide copolymer surface graft and then loaded with gentamicin . Implantation periods varied from day 4, to week 3 1/2, to week 10 . We investigated tissue reactions in the absence of an infectious challenge and also the efficacy of surface-modified leads in preventing infection after challenge with Staphylococcus aureus was evaluated . It was demonstrated that the applied surface modification did not induce adverse effects although during early postimplantation an increase in infiltration of granulocytes and macrophages and wound fluid and fibrin deposition were observed . After bacterial challenge, standard leads were heavily infected at each explantation period, denoted by abscesses, cellular debris, and bacterial colonies . In contrast, little or no infection was observed, either macroscopically or by bacterial cultures, with the surface-modified leads . Microscopy showed little evidence of the bacterial challenge, and that primarily at day 4 . It was concluded that the applied surface modification demonstrated enhanced infection resistance and thus represents a sound approach to the battle against infectious complications with biomaterials. Medicina (B Aires), 1997, 57(3), 281 - 6 {Community-acquired Staphylococcus aureus bacteremia in children: analysis of mortality risk factors}; Paganini HR et al.; Sixty episodes of community-acquired Staphylococcus aureus bacteremia (SaCB) were prospectively analyzed between January 1990 and December 1994 . The mean age of the patients was 78 (1-180) months . Thirteen (55%) of the children had underlying disease, the most frequent one being acute lymphoblastic leukemia . In 83% of the episodes a primary site of infection was observed . Skin and osteoarticular foci were the most frequently encountered . Only two patients had endocarditis . Arterial hypotension was detected in 17% of the patients . Ninety two percent of S . aureus isolated were penicillin-resistant . Only two strains were methicillin-resistant . In 24 (40%) episodes where metastatic foci were detected, osteoarticular infections were predominant . Mortality due to SaCB was 20% . Multivariate analysis by logistic regression revealed that arterial hypotension (RR = 24.8; 4.77-128.9), leucopenia (RR = 10.3; 1.25-86.2) and non hemato-oncologic diseases (RR = 10.0; 1.09-92.2) correlated with high mortality rate (p = < 0.001). Berl Munch Tierarztl Wochenschr, 1998 May, 111(5), 161 - 3 Experimental induction of renal lesions in chickens; Sokkar SM et al.; The present work was conducted to investigate the possibility of inducing renal lesions in chickens subcutaneously or orally inoculated with E . coli {E . coli O1K67(B12)}, Staphylococcus aureus and Actinomyces pyogenes . The strains were previously isolated from the kidneys of broilers showing different pathological lesions . The gross lesions observed in the kidneys included enlargement, congestion, haemorrhagic spots in addition to dilatation and distension of the ureters . The microscopic lesions were mainly interstitial nephritis . The lesions were acute and changed gradually to subacute or chronic nephritis . The glomerular lesions were not common . The wall of the primary branches of the ureter and the ureters was heavily infiltrated with inflammatory cells, also granular and albuminous casts were seen in the renal tubules . The lesions were not related to the inoculated pathogen, although they were more severe in chickens inoculated with E . coli and Staph . aureus more than in Actinomyces pyogenes . Reisolation of the inoculated pathogens was more successful from the birds inoculated subcutaneously than from those infected orally. Zentralbl Bakteriol, 1998 May, 287(4), 433 - 47 Virulence factors of Staphylococcus aureus in the pathogenesis of endocarditis . A comparative study of clinical isolates; Nozohoor S et al.; It is now generally accepted that adherence of microorganisms to various components of cardiac valve surfaces or vegetation lodging on the heart valves is an important early event in the pathogenesis of infective endocarditis . 120 clinical isolates of S . aureus obtained from patients with endocarditis and wound infections and from nasopharyngeal carriers were quantitatively analysed in vitro for their ability to bind to fibronectin and to produce protein A and alpha-toxin . Both cell-bound and extracellular protein A were measured and alpha-toxin was determined as antigen and as haemolytic activity . The highest fibronectin binding ability was found in carrier strains while no significant differences between strains were observed regarding the production of protein A . Strains isolated from patients with endocarditis produced significantly lower amounts of alpha-toxin than did strains from the other two groups . An inverse relationship between the production of protein A and of alpha-toxin was noticed in the material . Animal passage of five strains in an experimental endocarditis model showed a good reproducibility of the test systems and one strain was upregulated in its fibronectin binding ability and in alpha-toxin production . These in vitro results indicate that the fibronectin binding ability is not the decisive adherence factor and question the role of alpha-toxin as a virulence factor in endocarditis. Zentralbl Bakteriol, 1998 May, 287(4), 363 - 73 Comparison of genetic characteristics of MRSA strains present in a Warsaw hospital in 1992 and 1996; Leski TA et al.; Nine isolates of methicillin-resistant Staphylococcus aureus (MRSA) collected in a Warsaw hospital in 1996 were typed by phenotypic (resistograms) and genotypic (PFGE and plasmid restriction analysis-REAP) methods . Twenty-four (MRSA) strains collected in this hospital during a period of the same duration in 1992 and typed earlier using resistograms and PFGE were also typed by REAP . Comparison of typing results obtained for isolates from 1992 and 1996 showed that strains characterised by PFGE patterns of two distinct types described as specific of the two clonally related groups of Polish MRSA in a multicentre study in 1992 are continuously present in the hospital . However, MRSA strains representing PFGE patterns not observed before were also found within the collection from 1996 . REAP typing has proved to have a discriminatory power similar to that of PFGE analysis . Nevertheless, due to the lack of plasmids or difficulties in plasmid DNA isolation in 3 out of 33 studied strains, the typability of REAP turned out to be lower than that of PFGE. Zentralbl Bakteriol, 1998 May, 287(4), 277 - 314 The genome of Staphylococcus aureus: a review; Mlynarczyk A et al.; The genome of Staphylococcus aureus consists of a single circular chromosome (2.7-2.8 mbp) plus an assortment of extrachromosomal accessory genetic elements: conjugative and nonconjugative plasmids, mobile elements (IS, Tn, Hi), prophages and other variable elements . Plasmids (1-60 kbp) are classified into 4 classes and there are 15 known incompatibility groups . Mobile elements of the genome (0.8-18 kbp) appear in the chromosome or in plasmids of classes II and III . Prophages (45-60 kbp) are integrated in the bacterial chromosome, and they are UV- or mitomycin-inducible . Temperate bacteriophages of S . aureus are members of the Siphoviridae and the serological groups A, B and F occur most frequently . In the paper presented, the characteristics of chromosome, plasmids, transposons and other genetic elements of S . aureus genome are given and an alphabetical list of known genes of this species is included. Infect Immun, 1998 Jul, 66(7), 3476 - 9 In vitro resistance to thrombin-induced platelet microbicidal protein is associated with enhanced progression and hematogenous dissemination in experimental Staphylococcus aureus infective endocarditis; Dhawan VK et al.; We examined the influence of thrombin-induced platelet microbicidal protein 1 (tPMP-1) on the progression and hematogenous dissemination of experimental endocarditis caused by isogenic Staphylococcus aureus strains differing in tPMP susceptibility (tPMPs) or resistance (tPMPr) in vitro . Following simultaneous challenge of animals with both strains, significantly higher tPMPr bacterial densities were present in vegetations (P < 0.0001), kidneys (P < 0 . 0001), and spleens (P < 0.0001) compared with those for the tPMPs strain . These data indicate that tPMP-1 limits the intravegetation proliferation and hematogenous dissemination of a tPMPs strain in experimental endocarditis, while the tPMPr phenotype confers a selective advantage associated with the enhanced progression of this infection. Infect Immun, 1998 Jul, 66(7), 3170 - 8 Factors affecting the collagen binding capacity of Staphylococcus aureus; Gillaspy AF et al.; To determine whether the ability of Staphylococcus aureus to bind collagen involves an adhesin other than the collagen adhesin encoded by cna, we examined the collagen binding capacity (CBC) of 32 strains of S . aureus . With only two exceptions, a high CBC corresponded with the presence of cna . Both exceptions involved cna-positive strains with a low CBC . The first was a single strain (ACH5) that encoded but did not express cna . The second were the mucoid strains Smith diffuse and M, both of which encoded and expressed cna but bound only minimal amounts of collagen . Analysis of capsule mutants suggests that the reduced CBC observed in the mucoid strains was due to masking of the collagen adhesin on the cell surface and that this masking effect is restricted to heavily encapsulated strains . Differences in the CBC of the remaining cna-positive strains were correlated to variations in the level of cna transcription and were independent of the number of B domain repeats in the cna gene . In all cna-positive strains other than ACH5, cna transcription was temporally regulated, with cna mRNA levels being highest in cells taken from exponentially growing cultures and falling to almost undetectable levels as cultures entered the post-exponential growth phase . The CBC was also highest with cells taken from exponentially growing cultures . Mutation of agr resulted in a slight increase in cna transcription and a corresponding increase in CBC during the exponential growth phase but did not affect the temporal pattern of cna transcription . Mutation of sar resulted in a more dramatic increase in CBC and a delay in the post-exponential-phase repression of cna transcription . Mutation of both sar and agr had an additive effect on both CBC and cna transcription . We conclude that (i) cna encodes the primary collagen-binding adhesin in S . aureus, (ii) sar is the primary regulatory element controlling expression of cna, and (iii) the regulatory effects of sar and agr on cna transcription are independent of the interaction between sar and agr. Am J Respir Crit Care Med, 1998 Jun, 157(6 Pt 1), 1838 - 43 Sublingual capnometry for diagnosis and quantitation of circulatory shock; Nakagawa Y et al.; We investigated sublingual tissue PCO2 during hemorrhagic and septic shock . Hemorrhagic shock was induced in 10 rats . Sublingual PCO2 increased from 45 to 125 mm Hg and arterial pressure declined from 138 to 49 mm Hg, end-tidal PCO2 decreased from 35 to 13 mm Hg, and cardiac index fell from 290 to 77 ml/min/kg . Arterial blood lactate increased from 0.9 to 15.8 mmol/L . Gastric PCO2 was measured in five animals and it increased from 46 to 87 mm Hg . No significant changes were observed in eight "sham" bled animals including the five animals in which gastric PCO2 was measured . Highly significant linear correlations (p < 0.001) between sublingual PCO2 and gastric PCO2 (r = 0.71), cardiac index (r = -0.74), and arterial lactate (r = 0.59) were documented . We subsequently investigated sublingual PCO2 in five animals in which sepsis was induced by intravenous infusion of live Staphylococcus aureus . Like hemorrhagic shock, highly significant linear correlations were observed between end-tidal PCO2 and cardiac index and between sublingual PCO2 and arterial blood lactate . Sublingual PCO2 promises to serve as a technically simple, noninvasive, and rapid response quantitator of severity of circulatory shock states. J Clin Invest, 1998 Jun 15, 101(12), 2640 - 9 Vaccination with a recombinant fragment of collagen adhesin provides protection against Staphylococcus aureus-mediated septic death; Nilsson IM et al.; Staphylococcus aureus is a major cause of nosocomial and community-acquired infections . Morbidity and mortality due to infections such as sepsis, osteomyelitis, septic arthritis, and invasive endocarditis remain high despite the use of antibiotics . The emergence of antibiotic resistant super bugs mandates that alternative strategies for the prevention and treatment of S . aureus infections are developed . We investigated the ability of vaccination with a recombinant fragment of the S . aureus collagen adhesin to protect mice against sepsis-induced death . Actively immunized NMRI mice were intravenously inoculated with the S . aureus clinical isolate strain Phillips . 14 d after inoculation, mortality in the collagen adhesin-vaccinated group was only 13%, compared with 87% in the control antigen immunized group (P < 0.001) . To determine if the protective effect was antibody mediated, we passively immunized naive mice with collagen adhesin-specific antibodies . Similar to the active immunization strategy, passive transfer of collagen adhesin-specific antibodies protected mice against sepsis-induced death . In vitro experiments indicated that S . aureus opsonized with sera from collagen adhesin immunized mice promoted phagocytic uptake and enhanced intracellular killing compared with bacteria opsonized with sera from control animals . These results indicate that the collagen adhesin is a viable target in the development of immunotherapeutics against S . aureus. J Immunol, 1998 Jun 15, 160(12), 5936 - 44 Molecular mechanisms of the induction of IL-12 and its inhibition by IL-10; Aste-Amezaga M et al.; Exogenously added IL-10 rapidly inhibited Staphylococcus aureus- or LPS-induced cytokine mRNA expression in human PBMCs and monocytes, with a maximal effect observed when IL-10 was added from 20 h before until 1 h after the addition of the inducers . Nuclear run-on assays revealed that the inhibition of IL-12 p40, IL-12 p35, and TNF-alpha was at the gene transcriptional level and that the addition of IL-10 to S . aureus- or LPS-treated PBMCs did not affect mRNA stability . The inhibitory activity of IL-10 was abrogated by cycloheximide (CHX), suggesting the involvement of a newly synthesized protein(s) . The addition of CHX at 2 h before S . aureus or LPS also inhibited the accumulation of IL-12 p40 mRNA, but did not inhibit IL-12 p35 and TNF-alpha mRNA . This finding suggests that p40 transcription is regulated through a de novo synthesized protein factor(s), whereas the addition of CHX at 2 h after S . aureus activation caused superinduction of the IL-12 p40, IL-12 p35, and TNF-alpha genes . These results indicate that in human monocytes, the mechanism(s) of IL-10 suppression of both IL-12 p40 and IL-12 p35 genes is primarily seen at the transcriptional level, and that the induction of the IL-12 p40 and p35 genes have different requirements for de novo protein synthesis. Zentralbl Hyg Umweltmed, 1997 Aug, 200(2-3), 172 - 88 {Insertion possibility of 16S-23S space amplification and random amplified polymorphic DNA analysis for typing of methicillin-resistant Staphylococcus aureus strains in the context of nosocomial infections}; Schmitz FJ et al.; Within the scope of the present study n = 183 MRSA isolates from the extended area of Dusseldorf and n = 93 international MRSA strains from seven different countries were typed by pulsed-field gel electrophoresis and two PCR methods (RAPD and 16S-23S-spacer amplification) . The isolates could be subdivided into 30 different types by PFGE, into 21 by means of RAPD and 18 by 16S-23S-spacer amplification . PFGE had the highest discriminatory potential, however, a combined use of the three typing methods allows a more detailed differentiation even of those isolates with identical PFGE pattern . Both amplification procedures were rapid, easy in handling with reproductable results . For a temporary epidemiological analysis within 24 hours, both amplification methods could be combined . In case the investigated isolates were still suspected of showing a "clonal identity", they should be analysed by additional PFGE (lasting about four days) . Although the international isolates were chosen by random selection, several MRSA strains with identical pattern could be found in different countries of the world . Some RAPD-, spacer- and PFGE pattern were constant over many years . This reflects a high genetic stability of single strains. Clin Infect Dis, 1998 Jun, 26(6), 1302 - 9 Staphylococcus aureus prosthetic valve endocarditis: optimal management and risk factors for death; John MD et al.; The mortality rate associated with Staphylococcus aureus prosthetic valve endocarditis (PVE) remains high . To identify clinical events associated with an increased risk of death among patients with S . aureus PVE and to evaluate the role of valve replacement surgery in reducing mortality, we conducted a retrospective cohort study of patients who met strict criteria for definite S . aureus PVE . The primary endpoint for the study was survival at 3 months from the date of diagnosis . S . aureus PVE was diagnosed in 33 patients . Of these, 14 (42%) died within 90 days of the diagnosis . Cardiac complications were detected in 22 (67%), and central nervous system (CNS) complications were detected in 11 (33%) . A stepwise logistic regression multivariate model demonstrated that cardiac complications, but not CNS complications, were associated with increased mortality and that performing valve replacement surgery during antibiotic therapy was associated with decreased mortality . These associations were confirmed by using a Cox proportional hazards model with time-dependent covariates to control for survival bias . Performing valve replacement surgery during antimicrobial therapy will reduce the mortality among patients with S . aureus PVE, even those without evidence of cardiac complications. Mol Microbiol, 1998 May, 28(3), 655 - 62 Transmembrane topology and histidine protein kinase activity of AgrC, the agr signal receptor in Staphylococcus aureus; Lina G et al.; The agr P2 operon in Staphylococcus aureus codes for the elements of a density-sensing cassette made up of a typical two-component signalling system and its corresponding inducer . It is postulated that the autoinducer, a post-translationally modified octapeptide generated from the AgrD peptide, interacts with a receptor protein, coded by agrC, to transmit a signal via AgrA regulating expression of staphylococcal virulence genes through expression of agr RNA III . We show by analysis of PhoA fusions that AgrC is a transmembrane protein, and confirm using Western blotting that a 46 kDa protein corresponding to AgrC is present in the bacterial membrane . This protein is autophosphorylated on a histidine residue only in response to supernatants from an agr+ strain, and can also respond to the purified native octapeptide . A recombinant fusion protein where most of the N-terminal region of AgrC is replaced by the Escherichia coli maltose-binding protein is also autophosphorylated in response to stimulation by agr+ supernatants or purified octapeptide . We conclude that AgrC is the sensor molecule of a typical two-component signal system in S . aureus, and that the ligand-binding site of AgrC is probably located in the third extracellular loop of the protein. FEMS Microbiol Lett, 1998 Jun 1, 163(1), 19 - 24 Iron repressibility of siderophore and transferrin-binding protein in Staphylococcus aureus; Lim Y et al.; In order to investigate whether the iron acquisition mechanisms of Staphylococcus aureus are induced by iron restriction in vitro, we examined S . aureus ATCC 6538 for production of siderophore and expression of transferrin-binding protein (SA-tbp) in normal or deferrated brain heart infusion broth (BHI) . Siderophore production was earlier and greater in the deferrated BHI . The SA-tbp, detected by ligand blot assay, was expressed only in the deferrated BHI . When human transferrin was added to the deferrated BHI, siderophore production was later and lower than when transferrin was not present . In conclusion, both iron acquisition mechanisms of S . aureus were found to be iron-repressible and via both of them, human transferrin-bound iron was utilized for growth under iron-restricted condition. FEMS Microbiol Lett, 1998 Jun 1, 163(1), 1 - 9 Cloning and characterization of an accessory gene regulator (agr)-like locus from Staphylococcus epidermidis; Van Wamel WJ et al.; The presence of sequences related to the agr of Staphylococcus aureus was demonstrated in Staphylococcus epidermidis by agr-specific PCR, and Southern blot . The agr-like locus of S . epidermidis A086 was cloned and sequenced . An overall homology of 68% was found between the agr locus from S . epidermidis and S . aureus . The agr locus from S . epidermidis was organized similar to those from S . aureus and S . lugdunensis . The putative RNAII molecule contains four open reading frames, agr A, B, C and D . AgrA was a response regulator . AgrB showed homology with transducer and translocase molecules . AgrC is expected to act as a histidine protein kinase in which a leucine zipper is present . AgrD is presumably processed into an autoinducer peptide . The putative RNAIII molecule contained an open reading frame encoding a putative 26 amino acid (aa) polypeptide, which differed in 3 aa from the RNAIII encoded delta-toxin of S . aureus . Kinetic studies showed that the production of this RNAIII was elevated during the post-exponential phase . delta-Toxin activity was demonstrated for 21 of 23 tested S . epidermidis strains . Kinetic studies of the production of delta-toxin showed that the toxin was produced during the post-exponential phase . Sequencing of S . epidermidis A097, which showed a delayed agr-response, revealed a truncated AgrC lacking the histidine kinase domain . These data indicate that an agr-like locus is active in S . epidermidis during the post-exponential phase. Br J Sports Med, 1998 Jun, 32(2), 153 - 4 An outbreak of methicillin resistant Staphylococcus aureus infection in a rugby football team; Stacey AR et al.; Outbreaks of infection caused by methicillin resistant Staphylococcus aureus are common in hospitals and nursing homes, but until now none have been reported in the community . This is a report of an outbreak involving five members of a rugby football team. Eur J Clin Microbiol Infect Dis, 1998 Feb, 17(2), 128 - 30 Influenza A outbreak among adolescents in a ski hostel; Lyytikainen O et al.; An outbreak of influenza A H3N2 with a high attack rate (49%) and abrupt onset (69% became ill within 2 days) occurred among 81 ski school participants who stayed in a crowded hostel in Austria in early 1997 . Two students were hospitalized with pneumonia; one of them died . Cultures of blood and/or respiratory secretions from the hospitalized students yielded toxin-producing Staphylococcus aureus . Influenza A H3N2 was confirmed serologically in four participants, including one surviving hospitalized student, and by polymerase chain reaction of lung tissue from the deceased student . This investigation demonstrates that influenza can cause an explosive outbreak among skiers in a crowded hostel, leading to severe complications among previously healthy adolescents. Electrophoresis, 1998 May, 19(5), 695 - 700 DNA cycle sequencing of a common restriction fragment of Staphylococcus aureus bacteriophages by capillary electrophoresis using replaceable linear polyacrylamide; Kleparnik K et al.; The nucleotide sequence of a part of a 4.9 kbp common restriction fragment isolated from Staphylococcus aureus bacteriophage (bacterial virus) 3A has been determined by capillary electrophoresis (CE) . The fast separation of sequencing fragments in linear polyacrylamide solution at a temperature of 55 degrees C allowed the reading of more than 650 bases of sequence in 60 min . The single strand (ss)DNA fragments were prepared by cycle sequencing with fluorescently labeled dideoxy-terminators on the cloned bacteriophage DNA template . With respect to analysis speed, sequence read-length, low sample consumption and automation, CE offers a simple, labor-saving and inexpensive procedure for DNA sequencing . Operating the CE columns at elevated temperature proved to be a rapid procedure capable of extending sequence read-length . The resulting sequence of the common restriction fragment can be used for the preparation of specific primers and oligonucleotide hybridization probes for identification of Staphylococcus aureus bacteriophages and/or prophages belonging to the bacteriophage species 3A. FEMS Microbiol Lett, 1998 May 15, 162(2), 265 - 74 The two-component lysis system of Staphylococcus aureus bacteriophage Twort: a large TTG-start holin and an associated amidase endolysin; Loessner MJ et al.; The lysis genes of the virulent Staphylococcus aureus bacteriophage Twort were cloned and their nucleotide sequences determined . The endolysin gene plyTW encodes a 53.3-kDa protein, whose catalytic site is located in the amino-terminal domain . An enzymatically active fragment (N-terminal 271 amino acids) was overexpressed in Escherichia coli and partially purified . The enzyme rapidly cleaves staphylococcal peptidoglycan, and was shown to act as N-acetylmuramoyl-L-alanine amidase (EC 3.5.1.28) . Significant sequence homology to the specific cell wall targeting domain of lysostaphin was observed in a 101-amino acid C-terminal overlap . However, we found that the large C-terminal portion (63%, 295 aa) of PlyTW is not required for staphylolytic activity . Located upstream of and overlapping plyTW by 35 bp in a different reading frame (+1), we identified holTW, which starts with a single TTG triplet . The gene specifies a 185-amino acid (20.5 kDa) holin protein, which features two potential hydrophobic, antiparallel transmembrane domains, and a highly charged, acidic C-terminus . HolTW is the largest class II holin described to date . It can substitute for the defective allele in phase lambda S' amber mutants, both in trans from an expression plasmid, and from within gt11::holTW . The proposed function is the formation of unspecific membrane lesions to promote access of the endolysin to the bacterial peptidoglycan. J Dairy Res, 1998 May, 65(2), 273 - 81 Behaviour and enterotoxin production by Staphylococcus aureus during the manufacture and ripening of raw goats' milk lactic cheeses; Vernozy-Rozand C et al.; To study the possible presence of staphylococcal enterotoxin A in raw goats' milk lactic cheese, milk was inoculated with an enterotoxigenic Staphylococcus aureus strain to a final concentration of 4, 5 and 6 log(cfu/ml) . Cheese was prepared following industrial specifications and ripened for 42 d . Detection of the enterotoxins was by the Vidas Staph enterotoxin test (BioMerieux) and by an indirect double-sandwich ELISA technique using anti-enterotoxin monoclonal antibodies . Staphylococcal counts declined markedly after draining, and by the end of ripening they had disappeared from some cheeses . In contrast, aerobic mesophilic organisms grew well . The level of staphylococcal enterotoxin A recovered varied from 1 to 2.5 ng/g cheese made with an initial population of 10(5) or 10(6) cfu/ml . Only traces of enterotoxin A (0.5 ng/g) were detected in cheeses made with the lowest Staph . aureus inoculum used in this study . Enterotoxin A was also detected in cheeses from which Staph . aureus had disappeared. J Nucl Med, 1998 Jun, 39(6), 1089 - 94 Imaging experimental osteomyelitis using radiolabeled liposomes; Awasthi V et al.; We evaluated radiolabeled liposomes (liposomes labeled both with 99mTc and 111In) for the early detection of osteomyelitis in an experimental model . METHODS: Liposomes, containing 5% polyethylene glycol-distearoyl phosphatidylethanolamine with encapsulated glutathione and deferoxamine, were prepared and labeled with 99mTc and 111In by a previously described method . Acute osteomyelitis was induced in male New Zealand rabbits by intramedullary injection of sodium-morrhuate and Staphylococcus aureus in the tibial bone marrow . Serial imaging studies, consisting of radiolabeled liposome imaging (2-4 mCi 99mTc and 75-125 microCi 111In), 99mTc-methylene diphosphonate (MDP) (3-5 mCi) and 67Ga-citrate (500 microCi), were performed starting at the third day after injection . Each radionuclide study was separated by at least 2 days . The animals also underwent radiography of the lower extremities . The animals were then killed and the infected tibia was excised for histopathology . RESULTS: For interpreting relative efficacy of individual radiopharmaceuticals, only animals showing positive histopathological findings (n = 9) were considered . Radiographs (Days 12, 13) were conclusive for osteomyelitis in only 3 rabbits . Radiolabeled liposome imaging (Days 4-6) showed positivity in 8 cases and was equivocal in 1 . Though the lesion could be delineated as early as 8 hr postinjection in the 99MTc window, the best target-to-nontarget ratio (T/NT) of 1.86 +/- 0.19 was obtained at 48 hr in the 111In window . Three-phase 99mTc-MDP scan (Day 7) was positive in only 5 rabbits with 3 hr T/NT of 1.6 +/- 0.23 . Galium-67-citrate images (Days 9-11) were positive in 8 cases and equivocal in 1, the mean 48 hr T/NT being 1.74 +/- 0.24 . These results show liposomes are better than 99mTc-MDP for imaging bone infection . Given the early localization and better quality of the images, radiolabeled liposomes also exhibited advantages over 67Ga-citrate for detection of acute osteomyelitis. Proc Natl Acad Sci U S A, 1998 Jun 9, 95(12), 6602 - 6 Bacteria lacking a multidrug pump: a sensitive tool for drug discovery; Hsieh PC et al.; Microorganisms express multidrug resistance pumps (MDRs) that can confound antibiotic discovery . We propose the use of mutants deficient in MDRs to overcome this problem . Sensitivity to quinolones and to amphipathic cations (norfloxacin, benzalkonium chloride, cetrimide, pentamidine, etc.) was increased 5- to 30-fold in a Staphylococcus aureus mutant with a disrupted chromosomal copy of the NorA MDR . NorA was required both for increased sensitivity to drugs in the presence of an MDR inhibitor and for increased rate of cation efflux . This requirement suggests that NorA is the major MDR protecting S . aureus from the antimicrobials studied . A 15- to 60-fold increase in sensitivity to antimicrobials also was observed in wild-type cells at an alkaline pH that favors accumulation of cations and weak bases . This effect was synergistic with a norA mutation, resulting in an increase up to 1,000-fold in sensitivity to antimicrobials . The usefulness of applying MDR mutants for natural product screening was demonstrated further by increased sensitivity of the norA- strain to plant alkaloid antimicrobials, which might be natural MDR substrates. Nucl Med Commun, 1998 Mar, 19(3), 271 - 81 The kinetics of radiolabelled interleukin-8 in infection and sterile inflammation; Van der Laken CJ et al.; Radiolabelled interleukin-8 (IL-8) is a promising agent for the imaging of infection and inflammation . Several experiments were performed to explore further the imaging potential of radiolabelled IL-8 . IL-8 was radioiodinated via the Bolton-Hunter method . Rabbits with focal infection (Escherichia coli, Staphylococcus aureus) or sterile inflammation (zymosan) were injected intravenously with 18.5 MBq (0.5 mCi) of 123I-IL-8 . In separate studies, rabbits were injected intravenously with 111In-granulocytes with or without 125I-IL-8 . Gamma camera images were obtained at 5 min, 1, 4 and 8 h post-injection (p.i.) . Biodistribution was determined at 8 h p.i . In all models, the biodistribution of 123I-IL-8 was characterized by rapid blood clearance and high uptake in infection and sterile inflammation . All foci could be clearly visualized within 4 h p.i . Ex vivo abscess-to-contralateral muscle ratios increased to 114.7+/-23.0 (E . coli), 52.3+/-24.5 (S . aureus) and 49.8+/-8.3 (zymosan) at 8 h p.i . In the circulation, most 123I-IL-8 was bound to erythrocytes . The abscess uptake of 125I-IL-8 reached high levels despite reduced migration of granulocytes towards the site of infection due to the anti-inflammatory activity of intravenously injected IL-8 . IL-8 could be injected without induction of neutropenia at a dosage of 2 ng kg(-1) . In conclusion, the characteristics of radiolabelled IL-8 for imaging of infection and sterile inflammation are highly encouraging and warrant further optimization for clinical application. Burns, 1998 Mar, 24(2), 91 - 8 Methicillin-resistant Staphylococcus aureus versus the burn patient; Cook N; Methicillin-resistant Staphylococcus aureus (MRSA) has become a frequent cause of nosocomial infection, its increasing prevalence posing serious therapeutic and infection control problems within the hospital environment . MRSA is a major challenge to the burn patient, with potential to cause significant morbidity and mortality . Burn patients have been shown to become colonised and infected more readily than other patient groups . Extensive burn injuries are particularly susceptible to infection as a result of the disruption of the normal skin barrier and accompanying depression of immune responses . Extended hospitalisation and antibiotic therapy have been identified as additional risk factors for MRSA carriage and infection . Microbial surveillance, epidemiological studies and the introduction of strict infection control regimes can reduce the prevalence of MRSA but may be insufficient for eradication or prevention of outbreak situations . Recognition of the clinical importance of MRSA to the burn patient highlights the need to take appropriate measures to minimise transmission and infection in this vulnerable group of patients. Antimicrob Agents Chemother, 1998 Jun, 42(6), 1355 - 60 Lysostaphin treatment of experimental methicillin-resistant Staphylococcus aureus aortic valve endocarditis; Climo MW et al.; The emergence of clinical isolates of methicillin-resistant Staphylococcus aureus with reduced susceptibility to vancomycin has prompted a search for new and novel therapeutic agents active against S . aureus . Lysostaphin, a peptidase produced by Staphylococcus simulans, specifically cleaves the glycine-glycine bonds unique to the interpeptide cross-bridge of the S . aureus cell wall . The effectiveness of various regimens of dosing with intravenous lysostaphin was compared to that of vancomycin in the rabbit model of aortic valve endocarditis caused by a clinical methicillin-resistant S . aureus isolate . All animals were treated for a total of 3 days . The most active regimen, lysostaphin given three times daily, produced sterile vegetations in 10 of 11 treated rabbits, with a mean reduction in vegetation bacterial counts of 8.5 log10 CFU/g compared to the counts in the untreated controls . In contrast, vancomycin given twice daily sterilized no vegetations and reduced vegetation bacterial counts by only 4.8 log10 CFU/g . Lysostaphin given once daily was less effective, reducing mean vegetation bacterial counts by only 3.6 log10 CFU/g, but the combination of lysostaphin once daily and vancomycin twice daily reduced the mean vegetation bacterial density by 7.5 log10 CFU/g, a result that was significantly better than that for either regimen alone (P < 0.05) . Lysostaphin was well tolerated by the rabbits, with no evidence of immunological reactions following up to 9 weeks of intravenous administration . We conclude that lysostaphin given alone or in combination with vancomycin is more effective in the treatment of experimental methicillin-resistant S . aureus aortic valve endocarditis than vancomycin alone. Nephrol Dial Transplant, 1998 May, 13(5), 1256 - 8 Optimizing screening procedures for Staphylococcus aureus nasal carriage in patients on haemodialysis; Wanten GJ et al.; BACKGROUND: So far it remains unclear what the optimal screening method for detection of S . aureus nasal carriage in patients on haemodialysis is with regard to number of cultures performed, culture interval, and necessity of a broth-enrichment procedure . METHODS: A prospective, uncontrolled study was performed at the renal unit of a tertiary care centre, including all haemodialysis patients (n=91) attending the unit during the study period . The purpose was to determine the optimal screening method for S . aureus nasal carriage in patients on haemodialysis . RESULTS: When compared to the conventional culture method, inclusion of a broth-enrichment procedure increased the number of cultures positive for S . aureus significantly (31 vs 24%, P<0.0001) . Of 91 patients 37% were S . aureus carriers (defined as at least 1 of 5 cultures positive), 33% were stable carriers (defined as at least 2 of 5 cultures positive) . Fourth and 5th cultures, taken at subsequent dialysis sessions, captured only two additional carriers (6% of all carriers) . With respect to culture results and identification of carrier status a short (1-h) and a long (>24-h) sampling procedure showed no significantly different results . CONCLUSIONS: S . aureus nasal carriage in haemodialysis patients can be conveniently established with three nasal cultures taken with 1-h intervals, and the inclusion of a broth-enrichment procedure. J Am Soc Nephrol, 1998 Jun, 9(6), 1085 - 92 Staphylococcus aureus prophylaxis in hemodialysis patients using central venous catheter: effect of mupirocin ointment; Sesso R et al.; Central venous catheterization is a common technique to establish rapid and temporary access for hemodialysis . However, it is a known risk factor for Staphylococcus aureus infection and bacteremia . Mupirocin is a topical antibiotic with high in vitro anti-staphylococcal activity . A randomized prospective trial was conducted to assess the effectiveness of mupirocin ointment in the prevention of Staphylococcus aureus skin and catheter colonization, and episodes of bacteremia in 136 end-stage renal disease patients . Of these, 67 received skin disinfection at the venous catheter insertion site with povidone iodine (control group), and 69 received the same treatment followed by application of 2% mupirocin ointment at the cannula site after catheter placement and at the end of each dialysis session . Patients were followed until catheter removal and were monitored for the development of Staphylococcus aureus skin/catheter colonization and episodes of bacteremia . Median duration of catheter use was greater in the mupirocin than in the control group (37 versus 20 d, P < 0.01) . Patients in the mupirocin group had a significantly lower rate of Staphylococcus aureus isolation from the pericatheter skin (1.76 per 1000 versus 14.27 per 1000 patient-days, P < 0.001) and from the catheter surface (3.17 per 1000 versus 14.27 per 1000 patient-days, P < 0.001) . The proportion of patients with Staphylococcus aureus skin infection at the insertion site was lower in the mupirocin group (4.3% versus 23.9%, P = 0.001) . Staphylococcus aureus-associated bacteremia was observed in 17 patients (two in the mupirocin group {0.71 episodes per 1000 patient-days} and 15 in the control group {8.92 per 1000 patient-days}, P < 0.001) . The hazard ratio of developing Staphylococcus aureus bacteremia was 7.2 (95% confidence interval, 1.6 to 31.6) times greater in patients not receiving mupirocin . Mupirocin applied to the insertion site significantly reduces the risk of Staphylococcus aureus skin and catheter colonization, exit-site infection, and Staphylococcus aureus bacteremia in hemodialysis patients. Biochem J, 1998 Jun 15, 332 ( Pt 3), 755 - 61 Reaction of soluble penicillin-binding protein 2a of methicillin-resistant Staphylococcus aureus with beta-lactams and acyclic substrates: kinetics in homogeneous solution; Graves-Woodward K et al.; The kinetics of reaction of solubilized penicillin-binding protein 2a (sPBP2a) of methicillin-resistant Staphylococcus aureus with a variety of beta-lactams and acyclic species was studied in homogeneous aqueous solution at 37 degreesC in 25 mM Hepes buffer, pH7.0, containing 1 M NaCl . Under these conditions, but not at lower salt concentrations, protein precipitation did not occur either during or after the reaction . The reactions of beta-lactams in general could be monitored by competition with a chromophoric beta-lactam, nitrocefin, or directly in certain cases by protein fluorescence . Rate constants for reaction of a wide variety of beta-lactams are reported . The interactions are characterized by a slow second-order acylation reaction followed by a slower deacylation . For example, the rate constants for benzylpenicillin were 12 M-1.s-1 and 3x10(-5) s-1 respectively . The acylation is slow in comparison with those of normal non-resistant high-molecular-mass penicillin-binding proteins . sPBP2a also seemed to catalyse the slow hydrolysis of a variety of acyclic depsipeptides but not that of a d-Ala-d-Ala peptide . The reactions with certain depsipeptides also led to protein precipitation . These reactions were, however, not affected by prior blockage of the beta-lactam-binding site by benzylpenicillin and thus might take place elsewhere on the enzyme . Two classes of potential transition- state analogue inhibitors, phosphonate monoesters and boronates, seemed to have little effect on the rate of reaction of sPBP2a with nitrocefin and therefore seem to have little affinity for the beta-lactam-binding/D,D-peptidase site. Biochem J, 1998 Apr 15, 331 ( Pt 2), 489 - 95 Inhibition of kinases impairs neutrophil activation and killing of Staphylococcus aureus; Schnyder B et al.; Intracellular phosphorylations polymorphonuclear neutrophils are mediated by kinases, including mitogen activated-protein (MAP) kinases and phosphatidylinositol 3-kinase . In the present study we demonstrate their effector functions upon both ligation of cell-surface seven-transmembrane-spanning receptors by bacterial peptide formylmethionyl-leucylphenylalanine as well as in the process of destruction of Staphylococcus aureus . To regulate neutrophil MAP kinases p38 and p44/42, specifically, we made use of their specific inhibitors 10 microM SK&F 86002 (for p38) and PD 098059 (for activating kinase of p44/42) . SK&F 86002 was a potent inhibitor (by 70%) of induced antimicrobial oxygen-radical generation compared with PD 098059 (by 20%) . SK&F 86002 and PD 098059 inhibited mobilization of a dominant neutrophil adhesion molecule, beta2 integrin, from cytoplasmic granules to the plasma membrane by 40 and 10% respectively, and the combination of the two drugs resulted in a 90% effect . The combined effect of both drugs was moderate inhibition of bacterial destruction, despite the fact that neither compound had detectable effect on bactericidal activity if applied individually . Bacterial destruction was also inhibited by wortmannin (0.1 microM), the specific inhibitor of phosphatidylinositol 3-kinase, which had previously been described to target various other activations of the neutrophil, including oxygen-radical generation . Although the relative contribution of p38 and p44/42 MAP kinases varied, the marked effects of the combined inhibition of the kinases revealed their concerted actions to be critical for normal neutrophil function. Lancet, 1998 May 30, 351(9116), 1614 - 9 Exanthematous disease induced by toxic shock syndrome toxin 1 in the early neonatal period; Takahashi N et al.; BACKGROUND: We have seen a number of patients who developed systemic exanthema and thrombocytopenia in the first week of life . Although nearly 100% of the patients were carriers of meticillin-resistant Staphylococcus aureus (MRSA), no clear link between MRSA and this exanthematous disease has yet been made . METHODS: 20 neonates with exanthema and thrombocytopenia were selected for study . To see whether superantigenic exotoxins from MRSA are involved in the pathogensis of the exanthematous disease, we studied the production of these exotoxins by MRSA isolates from the neonates . We studied the expression of T-cell-receptor Vbeta and CD45RO in T cells taken from four of the neonates . We also analysed the DNA sequences of 16 cloned Vbeta2-positive T-cell-receptor-chain genes taken from two of the neonates . FINDINGS: Although most of the patients recovered within 5 days of onset of the exanthematous disease without any active treatment, two preterm infants died in the recovery phase . All patients showed colonisation by MRSA . The MRSA produced toxic shock syndrome toxin-1 (TSST-1) . The number of T cells positive for T-cell-receptor Vbeta2, reactive to TSST-1, was increased in the four patients studied (p<0.0001), and these T cells expressed CD45RO (p=0.0185) . None of the Vbeta2 clones had the same junctional sequences . INTERPRETATION: The polyclonal expansion of Vbeta2-positive T cells in patients colonised by TSST-1-producing MRSA suggests that the pathogenic micro-organism of this neonatal exanthematous disease is S aureus, mainly MRSA, and that in its pathogenesis it activates T cells by TSST-1 . Although the pathogenesis of both this exanthematous disease and toxic shock syndrome are fundamentally the same, a diagnosis of toxic shock syndrome cannot be made in this case, based on the clinical criteria for toxic shock syndrome . We propose neonatal toxic-shock-syndrome-like exanthematous disease (NTED) as the name for this disease. J Clin Microbiol, 1998 Jun, 36(6), 1653 - 9 Assessment of resolution and intercenter reproducibility of results of genotyping Staphylococcus aureus by pulsed-field gel electrophoresis of SmaI macrorestriction fragments: a multicenter study; van Belkum A et al.; Twenty well-characterized isolates of methicillin-resistant Staphylococcus aureus were used to study the optimal resolution and interlaboratory reproducibility of pulsed-field gel electrophoresis (PFGE) of DNA macrorestriction fragments . Five identical isolates (one PFGE type), 5 isolates that produced related PFGE subtypes, and 10 isolates with unique PFGE patterns were analyzed blindly in 12 different laboratories by in-house protocols . In several laboratories a standardized PFGE protocol with a commercial kit was applied successfully as well . Eight of the centers correctly identified the genetic homogeneity of the identical isolates by both the in-house and standard protocols . Four of 12 laboratories failed to produce interpretable data by the standardized protocol, due to technical problems (primarily plug preparation) . With the five related isolates, five of eight participants identified the same subtype interrelationships with both in-house and standard protocols . However, two participants identified multiple strain types in this group or classified some of the isolates as unrelated isolates rather than as subtypes . The remaining laboratory failed to distinguish differences between some of the related isolates by utilizing both the in-house and standardized protocols . There were large differences in the relative genome lengths of the isolates as calculated on the basis of the gel pictures . By visual inspection, the numbers of restriction fragments and overall banding pattern similarity in the three groups of isolates showed interlaboratory concordance, but centralized computer analysis of data from four laboratories yielded percent similarity values of only 85% for the group of identical isolates . The differences between the data sets obtained with in-house and standardized protocols could be the experimental parameters which differed with respect to the brand of equipment used, imaging software, running time (20 to 48 h), and pulsing conditions . In conclusion, it appears that the standardization of PFGE depends on controlling a variety of experimental intricacies, as is the case with other bacterial typing procedures. J Hosp Infect, 1998 May, 39(1), 19 - 26 Control of an outbreak of an epidemic methicillin-resistant Staphylococcus aureus also resistant to mupirocin; Irish D et al.; An epidemic methicillin-resistant Staphlococcus aureus (EMRSA-3) appeared in a District hospital in June 1989 as part of a regional outbreak . The dynamics of the outbreak were complex and involved patient transfer between hospitals and wards . Control measures followed UK guidelines and included the use of nasal mupirocin . During these efforts a mupirocin-resistant MRSA {MuMRSA: mupirocin minimum inhibitor concentration (MIC) > 256 mg/L} emerged, probably in a patient who had been given eight mupirocin courses over nine months . The MuMRSA had a narrower phage-typing pattern than EMRSA-3, but was indistinguishable by pulsed-field gel electrophoresis of SmaI chromosomal restriction enzyme digests and its susceptibility pattern to other antibiotics . The results of in vitro curing and gene probing indicated that mupirocin resistance was encoded on a 48 Md plasmid . MuMRSA spread occurred in 12 patients and 11 staff . The affected patients were nursed on the same ward . The strain was eradicated from patients with oral ciprofloxacin and rifampicin, triclosan skin treatment and nasal fusidic acid and bacitracin cream . The control of the outbreak had significant medical, social and financial implications . Fortunately, there were alternative topical agents to mupirocin, an agent which has played such a key role in MRSA eradication in recent years. Cytokine, 1998 Apr, 10(4), 241 - 8 Detection, cDNA cloning and sequencing of canine interleukin 12; Buttner M et al.; In canine peripheral blood mononuclear cells (PBMC) the mRNAs coding for both subunits of canine interleukin 12 (IL-12) were identified using reverse transcription polymerase chain reaction (RT-PCR) . Stimulation of canine PBMC with Staphylococcus aureus strain Cowan plus Concanavalin A for 5 h resulted in significant mRNA synthesis . Likewise, inactivated vaccinia virus induced IL-12 mRNA synthesis, however with different kinetics . The complete nucleotide sequence for both IL-12 subunits was determined using rapid amplification of cDNA ends (RACE)-PCR and cloning of amplified specific cDNAs . Computer-aided amino acid (aa) sequence comparison of both canine IL-12 subunits revealed more than 80% identity with the amino acid sequences of six other mammalian species . Closest relationship was found to human, porcine, bovine and cervine IL-12 . However, no reactivity was found with antibodies directed against human IL-12, when supernatants of stimulated canine PBMC were tested . Supernatants of canine PBMC stimulated for IL-12 release also induced interferon gamma (IFN-gamma) mRNA as detectable by RT-PCR; however, it was not clear whether IFN-gamma mRNA synthesis was due to an IL-12 specific effect or other stimuli . As to the stimulating effect of IL-12 on canine IFN-gamma mRNA synthesis, recombinant human IL-12 was found to be a good inducer . Since IL-12 is regarded a major regulatory molecule of T-cell-mediated immune response and cell growth our work on the cloning and sequencing of this cytokine from dogs lays the basis for future investigations on the biological and possible therapeutic role of canine IL-12. J Struct Biol, 1998, 121(2), 110 - 22 alpha-Hemolysin from Staphylococcus aureus: an archetype of beta-barrel, channel-forming toxins; Gouaux E; alpha-Hemolysin, secreted from Staphylococcus aureus as a water-soluble monomer of 33.2 kDa, assembles on cell membranes to form transmembrane, heptameric channels . The structure of the detergent-solubilized heptamer has been determined by X-ray crystallography to 1.9 A resolution . The heptamer has a mushroom-like shape and measures up to 100 A in diameter and 100 A in height . Spanning the length of the molecule and coincident with the molecular sevenfold axis is a water-filled channel that ranges in diameter from approximately 16 to approximately 46 A . A 14 strand antiparallel beta-barrel, in which two strands are contributed by each subunit, defines the transmembrane domain . On the exterior of the beta-barrel there is a hydrophobic belt approximately 30 A in width that provides a surface complementary to the nonpolar portion of the lipid bilayer . The extensive promoter-protomer interfaces are composed of both salt-links and hydrogen bonds, as well as hydrophobic interactions, and these contacts provide a molecular rationalization for the stability of the heptamer in SDS solutions up to 65 degrees C . With the structure of the heptamer in hand, we can better understand the mechanisms by which the assembled protein interacts with the membrane and can postulate mechanisms of assembly. Cell Mol Life Sci, 1998 Apr, 54(4), 372 - 7 Beta-lactamases as models for protein-folding studies; Vanhove M et al.; This review traces some of the key features of the folding of beta-lactamases and their relevance to the way proteins fold in general . Studies on the enzymes have highlighted the nature and role of equilibrium and transient condensed states . The kinetics of folding are multiphasic, and when monitored by acrylamide quenching of the tryptophan fluorescence, an early phase provides evidence for the transient accumulation of a nonnative intermediate involving burial of tryptophan in a nonpolar environment . Intermediate phases can be understood in terms of progressive folding of different parts of the molecule . The later, slow phases are associated with proline isomerization in the TEM-1 enzyme and, in its P167T mutant form, with isomerization from trans to cis of the E166 T167 peptide bond . Coupled with kinetic and X-ray crystallographic studies of the beta-lactamase from Staphylococcus aureus and its D179Q mutant, it appears that the final stage of folding is that of collapse and packing of the omega-loop on to the main body of the protein. Cell Mol Life Sci, 1998 Apr, 54(4), 300 - 4 Assembly of the monomer unit of bacterial peptidoglycan; van Heijenoort J; The biosynthesis of peptidoglycan is a two-stage process . The first stage concerns the endocellular assembly of its monomer unit, whereas the second one concerns the exocellular polymerization steps . The continued interest for this system is due to (i) the emergence of new resistance mechanisms; (ii) the need of specific targets in the search for new antibacterials; and (iii) the steady progress in the study of the correlation of peptidoglycan metabolism with cell growth and division . The various steps of the assembly of the monomer unit will be discussed as well as the correlations between the two stages . Finally, the flexibility of the pathway will be exemplified in Escherichia coli and Staphylococcus aureus. Biosci Biotechnol Biochem, 1998 Apr, 62(4), 825 - 8 Complete amino acid sequence of chitinase-A from leaves of pokeweed (Phytolacca americana); Yamagami T et al.; The complete amino acid sequence of pokeweed leaf chitinase-A was determined . First all 11 tryptic peptides from the reduced and S-carboxymethylated form of the enzyme were sequenced . Then the same form of the enzyme was cleaved with cyanogen bromide, giving three fragments . The fragments were digested with chymotrypsin or Staphylococcus aureus V8 protease . Last, the 11 tryptic peptides were put in order . Of seven cysteine residues, six were linked by disulfide bonds (between Cys25 and Cys74, Cys89 and Cys98, and Cys195 and Cys208); Cys176 was free . The enzyme consisted of 208 amino acid residues and had a molecular weight of 22,391 . It consisted of only one polypeptide chain without a chitin-binding domain . The length of the chain was almost the same as that of the catalytic domains of class IL chitinases . These findings suggested that this enzyme is a new kind of class IIL chitinase, although its sequence resembles that of catalytic domains of class IL chitinases more than that of the class IIL chitinases reported so far . Discussion on the involvement of specific tryptophan residue in the active site of PLC-A is also given based on the sequence similarity with rye seed chitinase-c. J Bacteriol, 1998 May, 180(10), 2759 - 65 Penicillin-binding protein 1 of Staphylococcus aureus is essential for growth; Wada A et al.; pbpA, a gene encoding penicillin-binding protein (PBP) 1 of Staphylococcus aureus, was cloned in an Escherichia coli MC1061 transformant which grew on a plate containing 512 microg of vancomycin per ml . This gene encodes a 744-amino-acid sequence which conserves three motifs of PBPs, SXXK, SXN, and KTG . The chromosomal copy of pbpA could be disrupted only when RN4220, a methicillin-sensitive S . aureus strain, had additional copies of pbpA in its episome . Furthermore, these episomal copies of pbpA could not be eliminated by an incompatible plasmid when the chromosomal copy of pbpA was disrupted beforehand . Based on these observations, we concluded that pbpA is essential for the growth of methicillin-sensitive S . aureus. J Bacteriol, 1998 May, 180(10), 2609 - 15 Genetic instability of the global regulator agr explains the phenotype of the xpr mutation in Staphylococcus aureus KSI9051; McNamara PJ et al.; Staphylococcus aureus KSI9051 has a complex mutation that was associated with the aberrant expression of cell surface and extracellular proteins (M . S . Smeltzer, M . E . Hart, and J . J . Iandolo, J . Bacteriol . 61:919-925, 1993) . This mutation was named xpr, although no specific gene was identified . Here this mutation is referred to as Delta1058::Tn551 . In this study, we show that in strain KSI9051, the Delta1058::Tn551 mutation occurred coincidentally with a frameshift in agrC that is expected to truncate the sensor component of the known staphylococcal global regulatory locus agr . Remarkably, pleiotropic mutations affecting cell surface and extracellular proteins are generated at frequencies approaching 50% upon the transduction of erythromycin resistance (Emr) encoded by Delta1058::Tn551 from S . aureus KSI905 back to its parental strain, S6C . Three independent isolates created in the manner of KSI9051 contained mutations within agrC . Each isolate had different mutations, suggesting that the transduction of Emr encoded by Delta1058::Tn551 affects the stability of agrC in S6C . In similar experiments with strains from an S . aureus 8325 genetic background, a mutant AgrC phenotype could not be isolated, implying that strain S6 has aberrant genetic behavior . A comparison of the nucleotide sequences of AgrC from several strains revealed seven errors in the GenBank entry for agr (X52543); these data were confirmed with plasmid pRN6650, the original wild-type clone of agr. Biochim Biophys Acta, 1998 Apr 29, 1397(2), 169 - 74 Analysis and overexpression in Escherichia coli of a staphylococcal gene encoding seryl-tRNA synthetase; Bausch N et al.; We have sequenced and expressed in Escherichia coli the gene encoding the seryl-tRNA synthetase from the pathogenic bacterium Staphylococcus aureus . The overexpressed and purified recombinant enzyme was able to aminoacylate unfractionated tRNA from E . coli . Its activity was not affected by antibodies raised against and inhibiting the E . coli seryl-tRNA synthetase . Infect Control Hosp Epidemiol, 1998 May, 19(5), 328 - 32 Staphylococcus aureus nasal colonization in patients with cirrhosis: prospective assessment of association with infection; Chang FY et al.; OBJECTIVE: To determine if Staphylococcus aureus colonization of the anterior nares was a risk factor for S aureus infection in patients with cirrhosis and to determine the predictors of S aureus infection in colonized patients . DESIGN: Prospective cohort study . PATIENTS: 84 consecutive patients with cirrhosis admitted to the liver transplant unit of a university-affiliated Veterans' Affairs Medical Center . RESULTS: Overall, 39 (46%) of the 84 patients were nasal carriers of S aureus, of which 24 (29%) were methicillin-resistant Staphylococcus aureus (MRSA) and 15 (18%) were methicillin-sensitive Staphylococcus aureus (MSSA) . Only MRSA, but never MSSA, carriage was acquired in the hospital; all 15 of the MSSA versus 14 (58%) of the 24 MRSA carriers were nasal carriers on first (admission) culture (P=.001) . Of the 10 (42%) of 24 MRSA carriers who were not colonized on admission, 3 became MRSA carriers within 1 month, and 7 acquired MRSA carriage more than a month later . Higher Child-Pugh score was independently associated with MRSA carriage (odds ratio {OR}, 1.54; 95% confidence interval {CI95}, 1.1-2.3) . S aureus nasal carriers (9 {23%} of 39) were significantly more likely to develop S aureus infections than noncarriers (2 {4%} of 45; P=.02) . Central venous catheter use was associated independently with S aureus infections in the carriers (OR, 4.1; CI95 2.8-6.1) . Mortality was significantly higher in carriers who developed S aureus infections as compared to those who did not (57% vs 13%; P=.022); S aureus infection was an independent predictor of mortality in the carriers (OR, 8.7; CI95, 1.2-63.8) . CONCLUSIONS: Colonization of the anterior nares was a significant predictor of S aureus infection in patients with cirrhosis. Bioorg Khim, 1998 Mar, 24(3), 163 - 70 {Complete amino acid sequence of catalase from the fungus Penicillium vitale}; Kozlov EA et al.; The polypeptide sequence of the unmodified catalase from Penicillium vitale containing 696 amino acid residues was deduced . The sequences of 76 tryptic peptides of the unmodified catalase, 63 tryptic peptides of the catalase with modified Lys residues, 48 peptides resulting from catalase cleavage by the Staphylococcus aureus V8 protease, and 9 fragments obtained by BrCN-treatment were considered, and a comparison with the sequences of other catalases was made. Vasa, 1998 May, 27(2), 122 - 4 Ruptured cervical aneurysm of the carotid artery--case report of a rare disease; Buerger T et al.; Rupture of a cervical carotid artery aneurysm is a rare but life-threatening event . The diagnostic evaluation and therapeutic management of a 55-year-old woman with such a lesion are described . In this case, the aneurysmal rupture was complicated by localized Staphylococcus aureus infection confirmed by bacteriologic culture of excised tissue, septicemia, and prevertebral and intraspinal abscess . Definitive diagnosis was a ruptured mycotic aneurysm of the extracranial carotid artery . The origin of the infection was probably the patient's previously infected vascular prosthesis for hemodialysis. Enferm Infecc Microbiol Clin, 1998 Mar, 16(3), 118 - 22 {Psoas muscle abscess . Description of a series of 19 cases}; Navarro V et al.; Abscess of the psoas muscle (PA) is every more frequently observed in recent years . The PA diagnosed in the authors' center over a period of 91 months are presented, analyzing the main clinical features, microbiologic causal agents, risk factors, treatment and the differences between primary and secondary PA . A total of 19 cases of which 14 were secondary PA (73.7%) and 5 primary PA (26.3%) were diagnosed . The main foci of infection of the former were the bone and the genitourinary tract, with intestinal infection being rare . The most frequent clinical data were lumbar pain with possible irradiation to the lower limb, fever, and leucocytosis with neutrophilia . Gram negative and enteric anaerobes were the bacteria most often identified, followed by Staphylococcus aureus and Mycobacterium tuberculosis . In a high percentage of patients (57.8%) a history of immunodeficiency was reported . In regard to treatment, surgical drainage was performed in 5 cases (26.3%), while ten cases (52.6%) were treated by DPCT . Four patients (21%) were exclusively treated with antibiotics . Recurrence was observed in three cases (15.3%) of the DPCT group requiring new drainage . Of all the cases, 18 were cured while one death occurred, being attributed to the underlying tumoral disease of advanced stage . The authors believe DPCT to be a good therapeutic option in both primary and secondary PA, thereby avoiding the risks of major surgery . In the cases with no underlying immunodeficiency the existence of secondary PA should be discarded as occurred in 7 out of 8 cases with no history of immunodeficiency in this series of patients. Microbiology, 1998 May, 144 ( Pt 5), 1359 - 67 Molecular characterization of an autolytic amidase of Listeria monocytogenes EGD; McLaughlan AM et al.; The gene encoding a 102 kDa autolysin has been cloned from an expression library of Listeria monocytogenes EGD genomic DNA, using a direct screening protocol . The encoded protein has two domains, an N-terminal enzymic domain showing a high level of homology to the amidase domain of the major autolysin (atl) of Staphylococcus aureus, and a C-terminal, putative cell-wall-binding domain containing four imperfect direct repeats . In order to examine the role of the enzyme, the autolysin-encoding gene was insertionally inactivated by site-specific integration of a temperature sensitive plasmid . The enzyme accounts for 66% of the total lytic enzyme activity when L . monocytogenes walls are used as substrate and several of the major autolytic bands are missing on renaturing gels when compared to the wild-type . The enzyme does not appear to be directly involved in cell separation but has a role in motility . Characterization of the recombinant enzyme expressed in Escherichia coli has revealed it to be an amidase and to be able to hydrolyse a range of peptidoglycan substrates. Comp Immunol Microbiol Infect Dis, 1998 Apr, 21(2), 115 - 33 Epidemiosurveillance of antimicrobial compound resistance of Staphylococcus intermedium clinical isolates from canine pyodermas; Pellerin JL et al.; In a retrospective study, 131 Staphylococcus intermedius strains isolated from apparently healthy dogs, and 187 Staphylococcus intermedius strains isolated from dog pyodermas in the clinical microbiology laboratory at the National Veterinary School in Nantes, during three successive periods: 1986-87, 1992-93 and 1995-96, were investigated and compared for their antimicrobial susceptibility . Results indicated that 60% to 65% of the strains were susceptible to Chloramphenicol and Doxycyclin, 65% to 80% of the strains were susceptible to macrolides (Erythromycin, Lincomycin and Clindamycin) and to Trimethoprim/Sulfonamide association . More than 95% of the strains were susceptible to three betalactamins tested: Oxacillin, Amoxycillin/Clavulanic acid, Cephalexin, to Gentamicin, to Fucidic Acid and to two quinolones: Enrofloxacin and Marbofloxacin . This last group is made up of choice antibacterials for the treatment of dog pyoderma . Many different resistance patterns were observed in each period with no really predominant profile, because of low plasmidic vs chromosomal balance of the genetic basis of antibacterial resistance in Staphylococcus intermedius . However, the proportion of multiresistant (> or = 3 drugs) strains increased from 10.8% in the first period, to 28% in the third period . This increased frequency of resistance suggests strongly that, as in Staphylococcus aureus human infections, the prescription of antibiotic compounds increases the prevalence of resistant strains. Biochem Biophys Res Commun, 1998 May 19, 246(2), 431 - 5 Methylesters of L-arginine and N-nitro-L-arginine induce nitric oxide synthase in Staphylococcus aureus; Choi WS et al.; The presence of L-arginine methylester (AME), L-arginine ethylester (AEE), or N-nitro-L-arginine methylester (NAME) in the growth media of Staphylococcus aureus increased the nitric oxide synthase (NOS) activity approximately 5- to 14-fold . The increase of NOS activity was confirmed by two assay methods, namely assaying the formation of L-{3H} citrulline from L-{3H} arginine and NO formation . The increase of NOS activity was most likely due to increased de novo synthesis, demonstrated by Western immunoblot analysis . The addition of methanol to the culture medium also increased the NOS activity as much as that found with the above three compounds . Evidence is presented to show that AME, AEE, or NAME gave rise to the formation of methanol in vivo by the action of intracellular esterase(s) and that methanol is subsequently involved in the induction of NOS in this bacterial system. J Nat Prod, 1998 May, 61(5), 640 - 2 Antibacterial activity of lonchocarpol A; Salvatore MJ et al.; Lonchocarpol A, a flavanone, demonstrates in vitro inhibitory activity against methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecium . This activity is antagonized by mouse plasma, which may account for its lack of in vivo activity . This compound demonstrates no differentiation with respect to the inhibition of RNA, DNA, cell wall, and protein synthesis. Arq Bras Cardiol, 1997 Dec, 69(6), 407 - 12 {Infective endocarditis in adolescents . Analysis of risk factors for hospital mortality}; Aoun NB et al.; PURPOSE: To study the epidemiological, clinical, therapeutic and evolutive aspects of endocarditis in a group of patients aging 12 to 20 years-old (mean 15.5) . METHODS: Thirty-three consecutive patients (14 males, 19 females) admitted with infective endocarditis were retrospectively studied . RESULTS: Infective endocarditis mortality was 42% . Rheumatic heart disease was the predominant underlying condition in 63% of patients . Congenital heart disease (24%) and cardiac prosthesis (12%) were the other affections involved . The majority of patients (78%) were in functional class III and IV, with more deaths than the 22% who were in functional class I and II (p = 0.01) . Staphylococcus aureus was the most frequently isolated agent (42% of the positive blood cultures, followed by Staphylococcus viridans, 21%) . Multivariate analysis identified total leukocyte count above 10,000/mm3 and functional class, both at admission (p = 0.01 and p = 0.004, respectively), and the occurrence of embolic complications (p = 0.03) as independent predictors of in-hospital mortality . CONCLUSION: Rheumatic heart disease remains, as in adults, the main predisposing factor for infective endocarditis in adolescents, and S . aureus is, like in children, the leading agent . Mortality is high and functional class at hospital admission, embolic complications and leukocytosis are independent predictors of in-hospital mortality. Infect Control Hosp Epidemiol, 1998 Apr, 19(4), 234 - 9 Comparison of vancomycin and cefuroxime for infection prophylaxis in coronary artery bypass surgery; Vuorisalo S et al.; OBJECTIVE: To investigate clinically significant differences between vancomycin and cefuroxime for perioperative infection prophylaxis in coronary artery bypass surgery . DESIGN: A total of 884 patients were randomized prospectively to receive either cefuroxime (444) or vancomycin (440) and were assessed for infectious complications during hospitalization and 1 month postoperatively . SETTING: A university hospital . RESULTS: The overall immediate surgical-site infection rate was 3.2% in the cefuroxime group and 3.5% in the vancomycin group (difference, -0.3; 95% confidence interval, -2.6-2.1) . CONCLUSIONS: The data suggest that vancomycin has no clinically significant advantages over cephalosporin in terms of antimicrobial prophylaxis . We suggest that cefuroxime (or first-generation cephalosporins, which were not studied here) is a good choice for infection prophylaxis in connection with coronary artery bypass surgery in institutions without methicillin-resistant Staphylococcus aureus problems . In addition to the increasing vancomycin-resistant enterococci problem, the easier administration and usually lower price of cefuroxime make it preferable to vancomycin. Microb Pathog, 1998 Apr, 24(4), 241 - 51 Assessment of the role of gamma-toxin in experimental endophthalmitis using a hlg-deficient mutant of Staphylococcus aureus; Supersac G et al.; Purified gamma-toxin is known to have a proinflammatory effect in the rabbit vitreous humor . To assess the biological role of the gamma-toxin, when expressed in vivo by Staphylococcus aureus strain Newman, the vitreous humor of rabbit eye was used as an infection model . A gamma-toxin-deficient mutant of strain Newman was constructed by allelic replacement . S . aureus Newman wild-type, its hlg-deficient derivative strain (N65) and the strain N65 complemented with the wild-type hlg+ gene were injected into the vitreous humor of rabbit eye . All three strains produced a strong proinflammatory effect in the eye conjunctiva, posterior and anterior chambers, suggesting a role for another unidentified proinflammatory component of strain Newman distinct from the gamma-toxin . These components are not the leucocidin of Panton-Valentine, beta-toxin or alpha-toxin which are not produced by this strain . Only the hlg-deficient mutant lacked the ability to cause inflammation in the eyelid, whereas the two Hlg-producing strains gave strong inflammation . These data suggest that in vivo, strain Newman produces as yet unidentified proinflammatory molecules and that the in vivo-produced HlgA, HlgB and HlgC molecules expressed by the gamma-toxin locus, contribute in part to the inflammatory process observed in vivo in the rabbit eye . Eur J Immunol, 1998 May, 28(5), 1534 - 43 Sequential production of IL-2, IFN-gamma and IL-10 by individual staphylococcal enterotoxin B-activated T helper lymphocytes; Assenmacher M et al.; Upon primary activation, T helper (Th) cell populations express different cytokines transiently and with different kinetics . Stimulation of naive murine splenic Th cells with the bacterial superantigen Staphylococcus aureus enterotoxin B (SEB) in vitro results in expression of IL-2, IFN-gamma and IL-10 with fast, intermediate and slow kinetics, respectively . This first report of a functional analysis of cells separated alive according to cytokine expression shows that these cytokines are not produced by different Th cell subpopulations, but can be expressed sequentially by individual Th cells . Th cells, activated with SEB for 1 day and isolated according to expression of IL-2, using the cellular affinity matrix technology, upon continued stimulation with SEB later secrete most of the IFN-gamma and IL-10 . Likewise, after 2 days of SEB culture, cells expressing IFN-gamma, separated according to specific surface-associated IFN-gamma as detected by magnetofluorescent liposomes, 1 day later secrete IL-10 . Thus, individual Th1 cells can contribute to the control of their own IFN-gamma expression by sequential expression of first IL-2, supporting their proliferation, and later IL-10, down-regulating the production of IFN-gamma-inducing monokines and limiting the pro-inflammatory effects of IFN-gamma. Transplantation, 1998 May 15, 65(9), 1169 - 72 Staphylococcus aureus nasal colonization and association with infections in liver transplant recipients; Chang FY et al.; BACKGROUND: Staphylococcus aureus has emerged as a leading cause of bacterial infections after liver transplantation . However, the role of nasal colonization in the development of S aureus infections has never been explored in liver transplant recipients . The objectives of this study were to determine whether nasal carriage of S aureus was a risk factor for S aureus infections in liver transplant recipients . METHODS: Over a 2-year period, 30 consecutive liver transplant recipients were studied . Beginning when the recipients were transplant candidates, nasal cultures were performed at each admission and monthly thereafter until discharge or death . RESULTS: Overall, 67% (20/30) of the patients were nasal carriers, 70% of the carriers had methicillin-resistant S aureus (MRSA), 15% had methicillin-sensitive S aureus, and 15% had both MRSA and methicillin-sensitive S aureus . Infections were significantly associated with the carrier state; 100% (9/9) of the infected patients were carriers as compared with 50% (11/21) of the noninfected patients (P=0.01) . All infections were a result of MRSA, and 56% (5/9) of the infections were bacteremia . Median time to the onset of S aureus infections was 16 days after transplant . Pulse field gel electrophoresis (with digestion of S aureus with SmaI restriction enzyme) in seven infected patients demonstrated that the isolates from the anterior nares matched the invasive isolates in all cases . A total of 43% (3/7) of these infected patients shared the same restriction pattern . CONCLUSION: MRSA colonization of the anterior nares was a significant predictor of MRSA infections in liver transplant recipients . Infections occurred only in those colonized with MRSA and were a result of the endogenously colonizing S aureus strains in all cases. J Hosp Infect, 1998 Apr, 38(4), 305 - 18 N-terminal sequence polymorphism in the coagulase gene of Staphylococcus aureus and its potential use as an epidemiological marker; el-Adhami W et al.; N-terminal DNA sequences of the coagulase gene were amplified from Staphylococcus aureus strain ISP8 (NCTC 8325-4) DNA using the polymerase chain reaction . The amplified DNA product (984 bp) was used to probe SmaI and DraI digested total DNA of methicillin- and multi-resistant S . aureus (MRSA) type strains, methicillin-sensitive S . aureus (MSSA) clinical isolates, and community (commensal) isolates . A SmaI fragment of a similar size in all the isolates examined hybridized with the coagulase gene fragment probe . All MRSA isolates, representing closely related (clonal) types, revealed identical coagulase hybridization patterns with DraI digested DNA . MSSA and community isolates closely related to ISP8 by SmaI fragment analysis shared closely related DraI/coagulase hybridization patterns, differing from that identified for the MRSAs . In contrast, the community and MSSA isolates not related to ISP8 as judged by total SmaI fragment polymorphisms, were also diverse in their DraI/coagulase hybridization patterns . In addition, the intensity of the hybridization signal obtained with the MRSA isolates varied significantly (less than) from the other isolates, indicating the presence of multiple and probably different coagulase genes between the isolates . The findings reported here indicate that hybridization analysis using single genes as DNA probes is less discriminant than restriction fragment length polymorphism analysis of the total genome of different isolates. J Hosp Infect, 1998 Apr, 38(4), 297 - 303 Limited effectiveness of chlorhexidine based hand disinfectants against methicillin-resistant Staphylococcus aureus (MRSA); Kampf G et al.; Hand disinfectants containing chlorhexidine are thought to be less bactericidal against methicillin-resistant Staphylococcus aureus (MRSA) than methicillin-susceptible Staphylococcus aureus (MSSA) . We report an in vitro comparison between three distinct MRSA strains and three MSSA strains . The bactericidal efficacy of chlorhexidine digluconate, 'Hibiscrub' and 'Hibisol' against Staphylococcus aureus was determined in a quantitative suspension test . Logarithmic reduction factors (RF) were calculated for each of six parallel experiments . Chlorhexidine digluconate and 'Hibisol' showed RF > 5 at most concentrations and reaction times but 'Hibiscrub' did not . MRSA was found to be significantly less susceptible than MSSA to chlorhexidine digluconate, 'Hibiscrub' and 'Hibisol' (P < 0.05; two-tailed t-test for independent samples) . 'Hibisol' was significantly more effective against MRSA than 'Hibiscrub' (P < 0.05) . Hand disinfectants containing both alcohol and chlorhexidine (e.g., 'Hibisol') are more effective against MRSA than scrubs based only on chlorhexidine ('Hibiscrub') and should be used in clinical practice. Pharmacol Res, 1998 Mar, 37(3), 197 - 201 In vitro interaction between spiramycin and polymorphonuclear neutrophils oxidative metabolism; Moutard I et al.; PMNs are a major component of body defense against microbial invasion, involving reactive oxygen species in great quantity, which could benefit from antibiotic therapy . Recently, possible antibiotic effects on phagocyte functions (impairment or stimulation of reactive oxygen species production) were studied . In our study, an in vitro evaluation was made on macrolide activity on phagocyte respiratory burst functions, using assay of superoxide anion (O2.-) in response to four stimuli systems: N-formyl Met-Leu-Phe (fMLP), an analogue of bacterial chemotactic factors; 4 beta-phorbol 12-myristate 13-acetate (PMA), a direct activator of protein kinase C (PKC); calcium ionophore (A23187), which acts directly on calcium influx; and a bacterial strain, Staphylococcus aureus . We have shown that spiramycin, at therapeutic plasma concentrations, increased O2.- generation by bacteria and fMLP-stimulated PMNs, with rate of 26% for 1 microgram ml-1 and 34% for 5 micrograms ml-1, respectively . This pro-oxidant effect, however, weaker, was observed when PMNs were stimulated by PMA . A weak anti-oxidant effect was observed with A23187 . For higher concentrations, spiramycin decreased strongly O2.- production, with IC50 values of 74 micrograms ml-1, 154 micrograms ml-1, 296 micrograms ml-1 and 400 micrograms ml-1 when PMNs were stimulated with bacteria, A23187, fMLP and PMA, respectively . The effect of spiramycin seemed to result from an intracellular mechanism by intervention of PMN oxidative metabolism (NADPH-oxidase activation), rather than a simple chemical interaction, because no effect has been observed in acellular models . For higher spiramycin concentrations, the decrease of O2.- production observed could not be taken into consideration because this concentration was not used in therapy . The enhanced of O2.- production observed could be used in therapy, so as to increase PMNs bactericidal activity. Infect Immun, 1998 Jun, 66(6), 3024 - 7 Enhanced levels of Staphylococcus aureus stress protein GroEL and DnaK homologs early in infection of human epithelial cells; Qoronfleh MW et al.; Antibodies to Staphylococcus aureus heat shock proteins (Hsps) are present in the sera of patients with S . aureus endocarditis (M . W . Qoronfleh, W . Weraarchakul, and B . J . Wilkinson, Infect . Immun . 61:1567-1570, 1993) . Although these proteins are immunogenic, their role in infection has not been established . We developed a cell culture system as a model to examine the potential involvement of staphylococcal Hsps in the initial events of infection . This study supports a model in which a clinical endocarditis isolate responds to host cell signals by selectively regulating the synthesis of numerous proteins, including the stress proteins Hsp60 (GroEL homolog) and Hsp70 (DnaK homolog) and a unique 58-kDa protein. J Biol Chem, 1998 May 22, 273(21), 13177 - 81 Multiple binding sites in the interaction between an extracellular fibrinogen-binding protein from Staphylococcus aureus and fibrinogen; Palma M et al.; Efb (previously Fib) is a fibrinogen-binding protein secreted by Staphylococcus aureus . It has previously been shown that it plays a role in a wound infection model in the rat and that antibodies against Efb reduce the number of recovered bacteria from the mammary glands in a mouse mastitis model . Efb binds to the alpha-chain of fibrinogen and does not participate in bacterial adherence to fibrinogen . The binding of Efb to fibrinogen is divalent, with one binding site within the two repeat regions in Efb at the N terminus and one binding site at the C terminus . The divalent binding nature leads to precipitation of Efb-fibrinogen complex when the proteins are added to each other at a 1:1 molar ratio . The interaction between Efb and fibrinogen is strongly enhanced by Ca2+ or Zn2+ but not by Mg2. Ugeskr Laeger, 1998 Apr 6, 160(15), 2257 - 60 {Spread and control of methicillin resistant Staphylococcus aureus in a department of dermatology}; Norregaard C et al.; Patients with skin diseases caused a spread of methicillin-resistant Staphylococcus aureus (MRSA) to 17 patients in our Department of Dermatology, because of their heavily scaly skin . Patients with severe dermatosis are regularly treated with dicloxacillin . The resistance of bacteria strain concerned suggests a selection because of the use of dicloxacillin in the Department . The strain is sensitive to gentamicin, which differentiates it from strains imported from abroad . Increased hygienic precautions, isolation of infected patients, staff and management efforts and a close contact with the microbiologists prevented MRSA from spreading to other hospital wards. J Biomed Mater Res, 1998 Jun 15, 40(4), 660 - 70 Influence of thrombus components in mediating Staphylococcus aureus adhesion to polyurethane surfaces; Baumgartner JN et al.; The role of protein and cellular components of thrombi in mediating bacterial adhesion on artificial surfaces was investigated in this study . The attachment of Staphylococcus aureus on polyurethane surfaces was observed directly using an automated video microscopy system . Surfaces were preconditioned with components of platelet-fibrin thrombi, including fibrinogen, thrombin, plasma, and isolated platelets . Experiments were performed in a radial flow chamber, and attachment rate constants were compared on the preconditioned surfaces in an effort to understand the complex relationship that exists between bacterial infection and thrombosis on synthetic biomaterials . Preadsorption of fibrinogen to surfaces significantly increased S . aureus adhesion compared to those preadsorbed with albumin alone while the presence of fibrin dramatically increased bacterial attachment compared to plasma preadsorbed surfaces . While the presence of adherent platelets also increased bacterial attachment, fibrin appeared to play a larger role in mediating bacterial adhesion on polyurethane surfaces . Striking results were obtained on the zwitterionic phosphonated polyurethane for a number of pretreatment conditions with regard to decreased bacterial adhesion and fibrinogen deposition. J Antimicrob Chemother, 1998 Apr, 41(4), 481 - 4 Relationship between ciprofloxacin, ofloxacin, levofloxacin, sparfloxacin and moxifloxacin (BAY 12-8039) MICs and mutations in grlA, grlB, gyrA and gyrB in 116 unrelated clinical isolates of Staphylococcus aureus; Schmitz FJ et al.; The in-vitro activities of five fluoroquinolones were tested against 70 ciprofloxacin-resistant and 46 ciprofloxacin-susceptible unrelated isolates of Staphylococcus aureus . All 116 S . aureus isolates were studied for the presence of mutations in the grl and gyr loci . The order of efficacy of the fluoroquinolones tested, from least to most active, was: ciprofloxacin, ofloxacin, levofloxacin, sparfloxacin and moxifloxacin (BAY 12-8039), in response to all characterized mutations in grlA, grlB, gyrA and gyrB . Moxifloxacin was active against most S . aureus isolates tested (MIC90 = 1 mg/L for ciprofloxacin-resistant isolates) and was less influenced by known mutations. Jpn J Antibiot, 1998 Mar, 51(3), 237 - 47 {Mechanism of vancomycin resistance in MRSA strain Mu50}; Hanaki H et al.; The mechanism of vancomycin resistance in methicillin-resistant Staphylococcus aureus (MRSA) Mu50 was investigated . More than 3 times increase of the incorporation of 14C-GluNAc into the cell wall of Mu50 was observed compared to those of vancomycin-susceptible strains FDA209P, H-1, LR5P1 . The amount of cytoplasmic murein-monomer precursor increased more than 3 times in Mu50 compared to those of control strains . There was an increased production of PBP1, PBP2, and PBP2', which were 1.51, 17.2, and 7.06 times greater, respectively, in Mu50 than those in H-1, and 2.38, 4.46, and 1.96 times greater respectively, than those in LR5P1 . By transmission electromicrograph, it was shown that the cell wall of Mu50 was twice thicker than that of LR5P1 . Increase of tightly-bound vancomycin to the cell wall fraction was observed in Mu50 when compared to those in FDA209P and H-1 strains . From these results, the increase of the vancomycin targets, free D-Ala-D-Ala residues in the cell wall, in number, due to the activated cell wall synthesis, and/or decrease of the cross-linkage of the cell wall was suggested to be the mechanism of vancomycin resistance in the Mu50 strain. Clin Infect Dis, 1998 May, 26(5), 1204 - 14 Genesis of methicillin-resistant Staphylococcus aureus (MRSA), how treatment of MRSA infections has selected for vancomycin-resistant Enterococcus faecium, and the importance of antibiotic management and infection control; Schentag JJ et al.; We extensively studied the epidemiology and time course of endemic methicillin-resistant Staphylococcus aureus (MRSA) in the Millard Fillmore Hospital, a 600-bed teaching hospital in Buffalo . The changeover from methicillin-susceptible S . aureus to MRSA begins on the first hospital day, when patients are given cefazolin as presurgical prophylaxis . Under selective antibiotic pressure, colonizing flora change within 24 to 48 hours . For patients remaining hospitalized, subsequent courses of third-generation cephalosporins further select and amplify the colonizing MRSA population . Therefore, managing antibiotic selective pressure might be essential . Other strategies include attention to dosing, so that serum concentrations of drug exceed the minimum inhibitory concentration, and antibiotic cycling . Although there are some promising new antibiotics on the horizon, it is necessary to deal with many resistance patterns by using the combined strategies of infection control and antibiotic management. Clin Infect Dis, 1998 May, 26(5), 1179 - 81 Staphylococcus aureus: a well-armed pathogen; Archer GL; Staphylococcus aureus is a virulent pathogen that is currently the most common cause of infections in hospitalized patients . S . aureus infection can involve any organ system . The success of S . aureus as a pathogen and its ability to cause such a wide range of infections are the result of its extensive virulence factors . The increase in the resistance of this virulent pathogen to antibacterial agents, coupled with its increasing prevalence as a nosocomial pathogen, is of major concern . The core resistance phenotype that seems to be most associated with the persistence of S . aureus in the hospital is methicillin resistance . Methicillin resistance in nosocomial S . aureus isolates has been increasing dramatically in United States hospitals and is also associated with resistance to other useful antistaphylococcal compounds . Possible ways to decrease the incidence of nosocomial S . aureus infections include instituting more effective infection control, decreasing nasal colonization, developing vaccines, and developing new or improved antimicrobials. J Clin Microbiol, 1998 Apr, 36(4), 1128 - 34 Application of an optimized and highly discriminatory method based on arbitrarily primed PCR for epidemiologic analysis of methicillin-resistant Staphylococcus aureus nosocomial infections; Olmos A et al.; The optimization of an arbitrarily primed PCR method for typing 96 methicillin-resistant Staphylococcus aureus (MRSA) isolates was compared with pulsed-field gel electrophoresis . Identical results in the differentiation of MRSA clones and identification of the main cluster that included 82 strains (88% of patients) were obtained by both techniques. J Clin Microbiol, 1998 Apr, 36(4), 1109 - 12 Sensitivity and specificity of an improved rapid latex agglutination test for identification of methicillin-sensitive and -resistant Staphylococcus aureus isolates; Smole SC et al.; The performance of a second-generation rapid agglutination kit, Slidex Staph Plus (SSP; bioMerieux), was compared to those of the Slidex Staph (SS; bioMerieux), Staphaurex (SRX; Murex Diagnostics), and BBL Staphyloslide (BBL; Becton Dickinson) kits by using 508 clinical isolates composed of 150 methicillin-sensitive Staphylococcus aureus (MSSA) organisms, 154 methicillin-resistant S . aureus (MRSA) organisms, and 204 non-S . aureus Staphylococcus spp . Of the 508 isolates tested, 75% were fresh clinical isolates, with the remainder taken from five different freezer collections . All four agglutination tests had comparable sensitivities for MSSA and MRSA . However, the SS kit was significantly less specific (93.1%) than the three other tests (P > 0.05, McNemar test) . These results demonstrate that the new rapid latex agglutination kit, SSP, was more specific for the identification of S . aureus than the previous version and performed comparably to the SRX and BBL kits. J Clin Microbiol, 1998 Apr, 36(4), 1042 - 5 Detection of staphylococcal superantigenic toxins by a CD69-specific cytofluorimetric assay measuring T-cell activation; Lina G et al.; The presence of staphylococcal superantigenic toxins in the supernatants of liquid cultures was detected by an easy and rapid method assessing the activation of T lymphocytes by cytofluorimetric measurement of CD69 expression . Staphylococcus aureus cells were grown in Eagle's minimum essential medium supplemented with 5% heat-inactivated fetal calf serum . Supernatant fluids from all S . aureus strains producing superantigen-related toxins, including enterotoxins A to E, toxic shock syndrome toxin, and exfoliative toxins A and B, induced CD69 expression in a significantly higher number of T cells than a cutoff of 2% . This CD69 assay might be used for initial detection of superantigens from S . aureus strains isolated in the context of staphylococcal toxemia or related chronic human diseases such as atopic dermatitis or Kawasaki syndrome. J Clin Microbiol, 1998 Apr, 36(4), 986 - 9 Soft salt-mannitol agar-cloxacillin test: a highly specific bedside screening test for detection of colonization with methicillin-resistant Staphylococcus aureus; Mir N et al.; The early detection of colonization with methicillin-resistant Staphylococcus aureus (MRSA) of patients in intensive-care units is an essential step in the strategy for preventing MRSA epidemics . In this study, tubes containing soft salt-mannitol agar with cloxacillin (6 microg/ml) (SSMAC) were prepared for inoculation of clinical samples at patients' bedsides by personnel of an intensive-care unit . A total of 1,914 swabs from different sample sites of 81 patients were dipped into SSMAC tubes, and after 24 h of incubation (in an incubator located near the intensive-care unit), an evident color change was considered by the intensive-care-unit personnel to be an MRSA alarm . Sixty-three (3.3%) SSMAC tubes were considered positive for MRSA, 1,827 (95.4%) were considered negative, and 24 (1.2%) were considered intermediate . Compared with values for parallel conventional surveillance cultures for MRSA, excluding tubes with intermediate results, the