Staphylococcus aureus

Anaesth Intensive Care, 1999 Oct, 27(5), 447 - 51
Pulsed-field gel electrophoresis is a useful tool in the monitoring of methicillin-resistant Staphylococcus aureus epidemic outbreaks in the intensive care unit; Cameron RJ et al.; We wished to determine how pulsed-field gel electrophoresis may be of use in monitoring methicillin-resistant Staphylococcus aureus (MRSA) outbreaks in the intensive care unit (ICU) . A retrospective epidemiological analysis was conducted . All 27 ICU patients and 11 patients from other hospital wards from whom MRSA was isolated over a one year period were included in the study . Seventeen of the 27 ICU MRSA isolates were analysed by pulsed-field gel electrophoresis for clonality and compared with the 11 other hospital isolates genotypes over the same period . During three MRSA outbreaks, five MRSA genotypes were identified in ICU whilst the same five genotypes and three additional were found in the rest of the hospital . Pulsed-field gel electrophoresis analysis was useful in identifying clonality of ICU MRSA infections and establishing that they were imported from hospital wards, rather than arising de novo in ICU . We were further able to identify clonal clusters within the unit linked by temporal and geographical proximity, suggestive of cross-infection . Pulsed-field gel electrophoresis typing might be additionally useful in tracing the source of human and/or environmental factors if a genotype were persistently identified.

Scand J Immunol, 1999 Oct, 50(4), 363 - 70
Staphylococcus aureus Cowan strain 1 activation of B-chronic lymphocytic leukaemia cells augments the response to CD40 stimulation; Soderberg O et al.; The signals involved in regulating the proliferation, differentiation and survival of B-chronic lymphocytic leukemia (B-CLL) cells are fully understood . B-CLL cells have been found to respond poorly to various activation signals and only after successful Epstein-Barr virus (EBV) transformation has it been possible to maintain such cells in long-term cultures . In this work we describe a new method to activate and induce proliferation in B-CLL cells and to maintain such cells in long-term culture for longer than 1 month . We used a combination of protocols in an attempt to mimic some of the signals of a thymus-dependent immune response . The B-CLL cells were first activated with Staphylococcus aureus Cowan strain 1 (SAC) particles plus thioredoxin (Trx), followed by stimulation with interleukin (IL)-2 + Trx . This treatment primed the cells for further stimulation with anti-CD40 monoclonal antibody (MoAb) presented on irradiated CD32L cells (the CD40-system) or soluble CD40 Ligand, and a combination of Trx and cytokines (IL-4 + IL-10), which allowed the cells to be maintained for up to 1 month with preserved viability and a variable rate of proliferation . However, induced proliferation of the B-CLL cells was limited to approximately 1 month, suggesting that additional signals are required to facilitate further proliferation.

FEMS Microbiol Lett, 1999 Oct 15, 179(2), 233 - 9
Potentiation of methicillin activity against methicillin-resistant Staphylococcus aureus by diterpenes; Nicolson K et al.; Totarol is a diterpene compound extracted from the totara tree . Totarol and eight other diterpenes were found to potentiate methicillin, one reducing the minimum inhibitory concentration of methicillin against resistant Staphylococcus aureus 256-fold . Totarol did not inhibit the synthesis of DNA or peptidoglycan in S . aureus, but reduced the respiration rate by 70% . Under potentiation conditions, diterpenes had only a slight effect on the respiration rate, but had a significant effect on expression of PBP 2a . We conclude that the primary staphylococcal target for totarol is the respiratory chain, but that potentiation of methicillin by diterpenes is by interference with PBP 2a expression.

Med Pregl, 1999 Jun-Aug, 52(6-8), 267 - 9
{Effect of the "baby friendly" program on the number of neonatal infections at the maternity ward in Senta}; Molnar-Sabo I et al.; INTRODUCTION: The aim of this paper was to assess how the Baby Friendly Hospital Initiative affects occurrence, structure and outcome of neonatal infections at our department . MATERIAL AND METHODS: This retrospective study included all newborn infants born in 1995, when all the babies were at the neonatal ward and all the babies born in 1998, who were with their mothers . Newborn infants with low-birth-weight or shortened gestation were excluded . The assumption was that faster onset of lactation and thus breast-feeding decrease incidence of infections, but that there is an increased risk due to hygienic habits of mothers, especially those with no qualifications and difficult living conditions . The paper assesses the percentage of infections occurrence . RESULTS: Occurrence of infection was established clinically, whereas general signs of infection, as well as local signs of infection were confirmed by laboratory and bacteriological findings . Antibiotic therapy was applied . In great number of infections Staphylococcus aureus was isolated . In 1998 a certain increase of low-birth-weight and low gestation newborn infants was registered . In mature babies included into the Baby Friendly Program, number of infections has not changed, but the treatment was a little shorter . Infections were much more frequent in low-birth-weight and low gestation newborn infants . On the average the treatment in such cases was a little longer, but not only due to infection . DISCUSSION: Baby Friendly Hospital Initiative has not significantly affected the incidence of intrahospital infections in newborn infants . On the average the treatment in mature newborn infants was shorter, probably due to better lactation and transfer of immunoglobulins from mother to child . CONCLUSION: If Baby Friendly Hospital Initiative means adequate epidemiological supervision of mothers, this program does not significantly affect the risk from intrahospital infections.

Microbiology, 1999 Sep, 145 ( Pt 9), 2497 - 505
Matrix-binding proteins of Staphylococcus aureus: functional analysis of mutant and hybrid molecules; Hartford O et al.; The fibrinogen-binding protein ClfA and the collagen-binding protein Cna are surface-associated adhesins of Staphylococcus aureus . ClfA has a dipeptide repeat region R composed mainly of serine and aspartate residues, more than 40 of which are required along with the 28-residue region W, the LPXTG motif and region M to display the ligand-binding region A on the cell surface in a functional form . Cna has a 61-residue region W and at least one 187-residue region B linking the collagen-binding region A to peptidoglycan . A cna mutant of S . aureus lacking region B was shown to bind collagen at the same level as wild-type Cna+ cells, indicating that region B is not necessary for ligand binding . Furthermore, altering the number of B repeats did not influence the level of collagen binding . In order to study the ability of C-terminal domains of Cna and ClfA to support functional ligand-binding activity of different adhesins, chimeric proteins were constructed and expressed in S . aureus . Surprisingly, the presence of a single Cna B domain and a nonapeptide linker located between ClfA region A and Cna region WM failed to support fibrinogen binding by S . aureus cells, despite the fact that ClfA region A was detected on the bacterial surface by immunoblotting . In contrast, the ClfA region A-Cna region B hybrid expressed as a recombinant protein in Escherichia coli did bind fibrinogen in Western ligand blots and in an ELISA-type assay . It is concluded that Cna region B cannot support functional display of ClfA region A on the bacterial cell surface . However, the ClfA dipeptide repeat region R and region WM did promote functional surface expression of the Cna collagen-binding domain in a hybrid Cna-ClfA protein.

Int J Biol Macromol, 1999 Nov, 26(2-3), 167 - 71
Micropurification of beta- and gamma-crystallins from rabbit aqueous humor; Leone MG et al.; Soluble crystallins are normally present in the aqueous humor, originating from the lens, and their concentration may increase in certain conditions such as cataract, possibly contributing to aqueous outflow pathway obstruction, leading to glaucoma . Whether the stability and the tendency of aqueous crystallins to aggregate are different in patients with certain forms of open-angle glaucoma has not so far been established, mainly due to the lack of a suitable purification procedure from this fluid in which crystallins are present at very low concentration together with dozens of other proteins . About 4 microg each of beta- and gamma-crystallins were obtained from 20 ml of rabbit aqueous humor by C8 reversed-phase high-performance liquid chromatography (HPLC) and high-performance electrophoresis chromatography (HPEC) . The identity of the proteins was confirmed by amino acid analysis following sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and electrophoretic blotting onto polyvinylidene fluoride membranes, with or without previous digestion with Staphylococcus aureus protease V8.

Mol Gen Genet, 1999 Sep, 262(2), 323 - 31
Interactive regulatory pathways control virulence determinant production and stability in response to environmental conditions in Staphylococcus aureus; Lindsay JA et al.; The accessory gene regulator (agr) and staphylococcal accessory regulator (sar) loci are important regulators of toxin production in Staphylococcus aureus . In this study we examined how environmental conditions degree of aeration and salt concentration - affect the transcription and translation of mRNAs for alpha-haemolysin (Hla) and serine protease (Ssp) via these pathways and influence the stability of these proteins . Using Northern analysis, we have confirmed earlier observations that sarA is involved in the upregulation of RNAIII, the effector molecule encoded by the agr locus . However, this effect was abolished in highly aerated cultures . While sarA does appear to have an up-regulatory effect on hla transcription that is independent of agr, we propose that the PC1839 (sarA) mutant produces less alpha-haemolysin activity mainly as a result of post-translational inactivation by proteases . The most obvious phenotypic feature of PC1839 (sarA) is the upregulation of proteases . In this study we show that ssp is repressed by SarA at the transcriptional level . Western analysis using an anti-alpha-haemolysin antibody identified a major breakdown product that is only present in the supernatant of strains that are overexpressing serine protease . We have also confirmed that agr exerts a significant regulatory influence on hla at the level of translation, as well as transcription . Finally, the addition of salt upregulates ssp transcription and dramatically downregulates transcription of hla, and is an example of an environmental parameter that affects toxin production independently of agr and sarA . How environmental signals are transduced to control alpha-haemolysin and serine protease production, activity and stability at multiple levels are discussed.

Mult Scler, 1999 Oct, 5(5), 327 - 34
Impaired interleukin-12 production in multiple sclerosis patients; Rohowsky-Kochan C et al.; Multiple Sclerosis (MS), a disease of the human central nervous system, is believed to be a T cell mediated autoimmune disorder with genetic and environmental influences . Interleukin-12 (IL-12), a proinflammatory cytokine produced primarily by antigen presenting cells is a potent inducer of interferon-gamma (IFN-gamma) and other Th1 cytokines that may play an important role in MS pathogenesis . We have investigated IL-12 production induced by the T cell independent pathway in untreated and IFN-beta treated MS patients, healthy individuals and other neurological disease (OND) patients in response to the human pathogen Staphylococcus aureus . We report that peripheral blood mononuclear cells (PBMC) from untreated MS patients produce normal amounts of the biologically active IL-12 p70 heterodimer but significantly less free IL-12 p40 heavy chain than PBMC from both healthy and disease controls when challenged in vitro with Staphylococcus aureus . Both mRNA expression of the inducible IL-12 p40 chain and protein levels were found to be reduced in untreated MS patients . No decrease in the production of the IL-12 p40 was seen in MS patients on IFN-beta therapy . The decreased production of IL-12 p40 heavy chain is not attributed to increased IL-10 secretion, a defect in the production of cytokines by macrophages or the number of cytokine producing cells . The factor(s) responsible for the decrease in p40 remain to be determined . Since IL-12 p40 antagonizes the biological activity of IL-12 in vitro and in vivo, identification of a defect in the 'natural' antagonist of IL-12, may provide the basis for immune therapy.

J Infect Dis, 1999 Nov, 180(5), 1561 - 8
Influence of in vitro susceptibility phenotype against thrombin-induced platelet microbicidal protein on treatment and prophylaxis outcomes of experimental Staphylococcus aureus endocarditis; Dhawan VK et al.; Thrombin-induced platelet microbicidal protein-1 (tPMP-1) is a small, cationic staphylocidal peptide from rabbit platelets . In the current study, the outcomes of vancomycin treatment and prophylaxis were compared in experimental infective endocarditis (IE) caused by an isogenic Staphylococcus aureus strain pair differing in tPMP-1 susceptibility (tPMPS) or resistance (tPMPR) in vitro (ISP479C and ISP479R, respectively) . Vancomycin therapy (selected for its intrinsically slow bactericidal activity) reduced ISP479C (but not ISP479R) densities in vegetations compared with controls (P<.01) . In contrast, prophylactic administration of vancomycin yielded no differences in efficacies for the 2 challenge strains . These data suggest that the tPMPR phenotype in vitro has a negative effect on the antimicrobial therapy (but not the prophylaxis) of experimental S . aureus IE . These disparate results may be explained in part by the requirement for microbicidal effects in the treatment of established IE, whereas prophylactic efficacy depends more on growth inhibitory and antiadhesion effects.

J Orthop Trauma, 1999 Sep-Oct, 13(7), 470 - 6
Influence of the design for fixation implants on local infection: experimental study of dynamic compression plates versus point contact fixators in rabbits; Arens S et al.; OBJECTIVES: Comparison of infection resistance after local bacterial challenge associated with two different designs for fixation implants: the conventional dynamic compression plate (DCP) and the point contact fixator (PC-Fix) . DESIGN: Randomized, prospective study in experimental animals . Grouped sequential experimental procedure . Observation time was twenty-eight days, with twenty animals per group . SETTING: Following surgery, animals were kept without restrictions in individual hutches . ANIMALS: Forty White New Zealand rabbits . Thirty-eight animals, nineteen per group, were included in the final evaluation . INTERVENTION: Under sterile conditions, specially manufactured titanium DCP or PC-Fix of identical dimensions were fixed to rabbit tibiae . After wound closure, different concentrations of Staphylococcus aureus, between 2 x 10(4) and 2 x 10(8) colony-forming units (CFU), were inoculated percutaneously at the implant site . MAIN OUTCOME MEASUREMENTS: Implants, underlying bone, and surrounding soft tissues were removed under sterile conditions and quantitatively evaluated for bacterial growth . Infection was defined as positive bacterial growth at the bone-implant interface . RESULTS: The overall infection rate was 45 percent . The infection dose of 50 percent (ID50) was 7.08 x 10(5) CFU for the DCP group and 8.51 x 10(6) CFU for the PC-Fix group . The infection rate was 63 percent (twelve of nineteen animals) for the DCP group and 26 percent (five of nineteen animals) for the PC-Fix group . This difference was statistically significant (p = 0.022) . CONCLUSIONS: After local bacterial challenge, we found a statistically significant difference in the infection rates depending on the implant design . The higher infection resistance associated with the PC-Fix design seems to be related to the reduced contact area at the bone-implant interface.

J Antibiot (Tokyo), 1999 Jul, 52(7), 660 - 5
In vivo antibacterial activity of FK041, a new orally active cephalosporin; Tawara S et al.; The therapeutic activities of orally administered FK041 were evaluated in mouse models of systemic and local infections with a variety of bacteria and were compared with those of cefdinir (CFDN) and cefditoren pivoxil (CDTR-PI) . FK041 exhibited potent therapeutic activity against lethal systemic infections induced by intraperitoneally inoculated Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae with 50% effective doses (ED50) in the range of 0.20 to 0.36 mg/kg and was more active than CFDN and CDTR-PI . This result correlated well with its in vitro activity . The therapeutic effects of FK041 and reference drugs on murine local infections were evaluated in an in vivo pharmacokinetic model simulating human plasma concentrations for oral administration of 50 mg, 100 mg, and 200 mg . Against murine subcutaneous abscess induced by S . aureus, FK041 was as effective as CFDN and significantly more effective than CDTR-PI in reducing the number of recoverable viable bacteria in the skin at the infection sites . The efficacy of FK041 against murine pneumonia with H . influenzae was comparable to that of CDTR-PI and was superior to that of CFDN in reducing viable bacteria activity in the lungs . These results strongly suggest that FK041 has potential for clinical use against various bacterial infections.

Arthritis Rheum, 1999 Sep, 42(9), 1823 - 7
Fcgamma receptor polymorphisms in Wegener's granulomatosis: risk factors for disease relapse; Dijstelbloem HM et al.; OBJECTIVE: Several studies have recently identified polymorphisms of receptors for the Fc fragment of IgG (FcgammaR) as genetic factors influencing susceptibility to multiple autoimmune and infectious diseases . This genetic predisposition could also influence the expression of Wegener's granulomatosis (WG), a systemic autoimmune disease with chronic nasal carriage of Staphylococcus aureus as an important risk factor for disease relapses . Therefore, we analyzed 3 functional FcgammaR polymorphisms from 91 patients with WG and 154 controls for a possible relationship with disease expression and occurrence of relapses . METHODS: FcgammaR phenotypes were determined using amplification of FcgammaR-genomic regions in allotype-specific polymerase chain reactions . Of particular interest in the analysis were 2 allotypic forms of FcgammaRIIa (R131 or H131) and 2 allotypic forms of FcgammaRIIIa (V158 or F158), all of which are functionally different . RESULTS: Analysis of FcgammaR phenotypes demonstrated that patients with WG were more prone to disease relapse in the first 5 years after diagnosis if they were homozygous for both the R131 form of FcgammaRIIa and the F158 form of FcgammaRIIIa (relative risk 3.3, 95% confidence interval 1.6-6.8) . These polymorphisms are both associated with decreased FcR-mediated clearance, which may be relevant to the chronic nasal carriage of S aureus . CONCLUSION: Both the R/H131 polymorphism of FcgammaRIIa and the V/F158 polymorphism of FcgammaRIIIa represent heritable risk factors for the development of disease relapses in WG.

J AOAC Int, 1999 Sep-Oct, 82(5), 1171 - 4
An immunoassay method for rapid detection of Staphylococcus aureus in cosmetics, pharmaceutical products, and raw materials; Hughes D et al.; The TECRA Staphylococcus aureus Visual Immunoassay allows a presumptive positive or negative result for the presence of S . aureus to be obtained within 26 h, in contrast to 4-5 days by traditional cultural methods . Presumptive positive immunoassay results are confirmed by streaking the enrichment broth onto conventional agar media . A validation study was undertaken to compare the TECRA assay with a cultural reference method based on the Bacteriological Analytical Manual (8th Ed.), which is also consistent with U.S . Pharmacopoeia requirements . The products tested included a range of cosmetics (toothpaste, shampoos, conditioners, sunscreens, moisturizers, lip and eye creams) and pharmaceuticals (cough mixtures, laxatives, ulcer treatments, infant formulae, antiseptic cream), as well as some pharmaceutical ingredients . Samples were inoculated with S . aureus at 10-20 cfu/g, and then enriched for 24 h at 35 degrees-37 degrees C at a product-to-sample ratio of 1:100 . Two different enrichment broths were used for the study: Tryptone Soya Broth with 4% Tween 80 and Modified Letheen Broth . For both enrichment broths, results of the immunoassay and the reference method showed close correlation . The TECRA S . aureus Visual Immunoassay provides a rapid and convenient alternative to cultural methods and provides advantages to industry, such as greater speed of product and ingredient release and faster tracing of contamination problems . Because the immunoassay may be read either visually or with the aid of a plate reader, there is no need for an initial outlay on capital equipment . However, the assay can be automated if required.

Vet Microbiol, 1999 Sep 15, 69(3), 217 - 24
Genotyping of Staphylococcus aureus isolated from bovine mastitis; Annemuller C et al.; The present study was designed to comparatively investigate 25 Staphylococcus aureus strains isolated from bovine subclinical mastitis . The S . aureus strains, obtained from six different farms at five locations in one region of Germany, were characterized by phenotypic and genotypic methods . The S . aureus could be identified and further characterized by their cultural, biochemical and hemolytic properties . To analyze the epidemiological relationship the isolates were subjected to DNA fingerprinting by macrorestriction analysis of their chromosomal DNA, by PCR amplification of the gene encoding the 16S-23S rRNA intergenic spacer, by PCR amplification of the gene encoding the IgG binding region and the X region of protein A and by amplifying, and subsequent, digestion of the gene encoding staphylococcal coagulase . The macrorestriction analysis revealed five DNA restriction patterns with DNA patterns I, III and IV occurring in three, four, and three different farms, respectively . In addition, clones with different DNA patterns could be found within one herd . The PCR products for the spacer DNA, the spa gene encoding the X region of protein A and the coa gene encoding coagulase corresponded mostly to the pattern observed by DNA fingerprinting . Amplification of the gene encoding the IgG binding region revealed sizes of 620 bp for 20 of the isolates and 280 bp for four isolates indicating, for the latter, a deletion of segments in this region . These findings show, that single, widely distributed clones seemed to be responsible for cases of bovine subclinical mastitis found in one region of Germany.

Vet Microbiol, 1999 Sep 15, 69(3), 189 - 98
Comparison of Staphylococcus aureus recovered from personnel in a poultry hatchery and in broiler parent farms with those isolated from skeletal disease in broilers; Rodgers JD et al.; Personnel from one broiler hatchery, and workers on 18 separate broiler parent farms which supply the hatchery, were tested for hand and nasal carriage of Staphylococcus aureus . In both locations, nasal carriage of S . aureus was more common than hand carriage . A total of 63 S . aureus strains were characterised by biotyping, protein A analysis and pulsed field gel electrophoresis (PFGE) typing . Of these, 36 were recovered from broiler hatchery personnel, 14 from broiler parent farm personnel and 13 from cases of skeletal disease in commercial broilers . Biotyping and protein A analysis indicated that none of the strains recovered from hatchery personnel were of the poultry biotype, but that two strains recovered from the hands of two broiler parent farm personnel could be grouped together with 12/13 of strains recovered from skeletal disease in broilers, as poultry biotypes . PFGE-typing could not distinguish 9/13 strains recovered from skeletal disease in broilers and one of the strains from the broiler parent farm personnel from isolate 24 (I . 24), which is the predominant S . aureus strain type associated with clinical disease in N . Ireland broiler flocks . The present study found no evidence of nasal carriage of S . aureus strains of poultry biotype by humans . The finding of hand carriage by broiler parent farm personnel, suggests that handling by personnel may contribute to the dissemination of I . 24 or other S . aureus strains associated with skeletal disease in broilers.

No To Shinkei, 1999 Sep, 51(9), 815 - 8
{Methicillin-resistant Staphylococcus aureus subdural abscess in an elderly patient with dementia}; Takahashi O et al.; A 74-year-old man was admitted to our hospital because of a fever of 38.2 degrees C and drowsiness . Two months before admission, he was admitted to another hospital with the diagnosis of Alzheimer's disease . One week before admission, he had a fever which was judged to be due to pyelonephritis . Because imipenem cilastatin and minocycline were not effective in relieving symptoms, he was transferred to our hospital . Methicillin-resistant Staphylococcus aureus (MRSA) was cultured from the blood, and vancomycin was started on the 5th hospital day . Because of the persistent fever and signs of inflammation, Gallium-scintigraphy was performed, showing abnormal accumulation in the left fronto-parietal region of the brain and the sacral region . Enhanced brain CT revealed a crescentic low density area and a fine, intense line of enhancement in the left fronto-parietal region . An emergency drainage of abscess was performed via single left fronto-parietal burr hole . A slightly yellowish, bloody, purulent fluid was obtained . The subdural space was irrigated with saline containing antibiotics and a drain was inserted . MRSA was cultured from the obtained fluid . The fever gradually subsided and drowsiness disappeared . He had had decubitus ulcer, stage I on the surface, in the sacral region, which later turned out to have unexpectedly deep undermining lesion reaching to periosteum . MRSA was cultured from this decubitus lesion . MRSA which entered into blood stream from the decubitus site might have been implanted in the subdural hematoma . Thus, subdural abscess should be kept in mind as an active differential diagnosis in elderly patients with fever and drowsiness.

Diabet Med, 1999 Sep, 16(9), 767 - 71
Methicillin-resistant Staphylococcus aureus: an increasing problem in a diabetic foot clinic; Tentolouris N et al.; AIM: To study the prevalence of pathogenic organisms and the prevalence and outcome of methicillin-resistant Staphylococcus aureus (MRSA) infection in foot ulcers in diabetic patients . METHODS: A retrospective analysis of wound swabs taken from infected foot ulcers in diabetic patients, selected from an outpatient diabetic foot clinic . Seventy-five patients (79 ulcers) with positive wound swabs were included . Size of ulcer and time to healing, in particular for MRSA-infected ulcers, were measured in all patients . RESULTS: Gram-positive aerobic bacteria were the commonest micro-organism isolated (56.7%) followed by gram-negative aerobic bacteria and anaerobes (29.8% and 13.5%, respectively) . Of the gram-positive aerobes, S . aureus was found most frequently and 40% were MRSA . MRSA was isolated more commonly in patients treated with antibiotics prior to the swab compared to those who had not received antibiotics (P = 0.01) . Patients whose foot ulcers were infected by MRSA had longer healing time than patients whose ulcers were infected by methicillin-sensitive S . aureus (mean (range) 35.4 (19-64) and 17.8 (8-24) weeks, respectively, P = 0.03) . CONCLUSION: MRSA infection is common in diabetic foot ulcers and is associated with previous antibiotic treatment and prolonged time to healing . Further studies are required to assess the need for antibiotics in treating foot ulcers in diabetes and to assess the optimum therapeutic approach to this problem.

J Immunol, 1999 Oct 15, 163(8), 4519 - 26
Nitric oxide participates in the recovery of normal jejunal epithelial ion transport following exposure to the superantigen, Staphylococcus aureus enterotoxin B; McKay DM et al.; Bacterial superantigens (SAgs) are potent T cell activators . Mice treated 4 h previously with the SAg, Staphylococcus aureus enterotoxin B (SEB), display reduced ion transport (assessed by short circuit current) responses to prosecretory stimuli, which normalize 24 h posttreatment . Here, mice were treated with SEB alone or in combination with an inhibitor of the inducible form of NO synthase (iNOS), l -NIL . Subsequently, jejunal iNOS expression was detected by immunohistochemistry, ion transport was evaluated in Ussing chambers, and serum levels of TNF-alpha and IFN-gamma were measured by ELISA . SEB-treated mice had increased epithelial iNOS immunoreactivity, and numerous iNOS-positive CD3+ T cells occurred in their mucosa and submucosa . Concomitant treatment with l -NIL did not affect the reduced short circuit current responsiveness to electrical nerve stimulation or the prosecretory agents, carbachol and forskolin, that occurred 4 h post-SEB (5 microgram) treatment . However, Isc responses in l -NIL- plus SEB-treated mice were still significantly reduced 24 h posttreatment, indicating a role for NO in the restoration of normal ion transport following exposure to SAgs . The prolongation of epithelial ion transport abnormalities correlated with elevated serum levels of TNF-alpha and IFN-gamma in mice treated 24 h previously with l -NIL plus SEB compared with those in controls and SEB-only-treated mice . Additionally, mice treated with l -NIL plus SEB and TNF-alpha- or IFN-gamma-neutralizing Abs displayed normal jejunal ion transport characteristics 24 h posttreatment . We conclude that NO mobilization is important in the homeostatic recovery response following immune stimulation by SAgs and that the beneficial effect of NO in this model system is probably via regulation of TNF-alpha and IFN-gamma production.

Bioorg Med Chem Lett, 1999 Sep 20, 9(18), 2685 - 90
3D QSAR studies on new oxazolidinone antibacterial agents by comparative molecular field analysis; Pae AN et al.; Three-dimensional QSAR studies for two series of new oxazolidinone antibacterial agents were conducted using the comparative molecular field analysis (CoMFA) . In vitro activities (MICs) of the compounds against methicillin-resistant Staphylococcus aureus 88 (MRSA 88) exhibited a strong correlation with their steric, electrostatic factors and lipophilicities.

Antimicrob Agents Chemother, 1999 Oct, 43(10), 2565 - 8
Treatment of experimental staphylococcal endocarditis due to a strain with reduced susceptibility in vitro to vancomycin: efficacy of ampicillin-sulbactam; Backo M et al.; We evaluated several 3-day antimicrobial regimens in the treatment of experimental endocarditis caused by an oxacillin-resistant Staphylococcus aureus strain exhibiting intermediate susceptibility in vitro to vancomycin (VISA) . Neither vancomycin alone nor trovafloxacin exhibited in vivo efficacy; addition of amikacin to vancomycin yielded a modest in vivo effect . In contrast, the combination of ampicillin and sulbactam was highly effective in vivo, causing a mean decrease in VISA vegetation densities of >5 log(10) CFU/g versus those of untreated controls.

Antimicrob Agents Chemother, 1999 Oct, 43(10), 2404 - 8
Multiple novel inhibitors of the NorA multidrug transporter of Staphylococcus aureus; Markham PN et al.; The multidrug transporter NorA contributes to the resistance of Staphylococcus aureus to fluoroquinolone antibiotics by promoting their active extrusion from the cell . Previous studies with the alkaloid reserpine, the first identified inhibitor of NorA, indicate that the combination of a chemical NorA inhibitor with a fluoroquinolone could improve the efficacy of this class of antibiotics . Since reserpine is toxic to humans at the concentrations required to inhibit NorA, we sought to identify new inhibitors of NorA that may be used in a clinical setting . Screening of a chemical library yielded a number of structurally diverse inhibitors of NorA that were more potent than reserpine . The new inhibitors act in a synergistic manner with the most widely used fluoroquinolone, ciprofloxacin, by substantially increasing its activity against both NorA-overexpressing and wild-type S . aureus isolates . Furthermore, the inhibitors dramatically suppress the emergence of ciprofloxacin-resistant S . aureus upon in vitro selection with this drug . Some of these new inhibitors, or their derivatives, may prove useful for augmentation of the antibacterial activities of fluoroquinolones in the clinical setting.

Perit Dial Int, 1999 Jul-Aug, 19(4), 376 - 9
Effect of duration of chronic peritoneal dialysis therapy on the development of peritonitis; Troidle L et al.; OBJECTIVE: Long-term chronic peritoneal dialysis (CPD) therapy has been associated with alterations in peritoneal membrane structure and peritoneal macrophage function . We thus reviewed our experience with the development of peritonitis among patients maintained on CPD therapy for various time periods to determine if the spectrum of organisms, rates of peritonitis, and outcome changed with the duration of CPD therapy . SETTING AND PATIENTS: Patients maintained on CPD therapy in our out-patient unit in New Haven, Connecticut . DESIGN: Retrospective review of the charts of patients maintained on CPD therapy (HomeChoice Cycler or Ultrabag, Baxter, McGaw Park, IL, U.S.A.) between 1 January 1997 and 31 March 1998 . These patients were divided into three groups: group 1, patients maintained on CPD therapy < or = 12 months; group 2, patients maintained on CPD therapy for 13-36 months; and group 3, patients maintained on CPD therapy for > or = 37 months . RESULTS: The study included 256 patients: 101 patients in group 1, 110 patients in group 2, and 45 patients in group 3 . All groups of patients were similar in age . There were significantly fewer Caucasians and fewer males in group 3 in comparison to groups 1 and 2 . The incidence of diabetes mellitus, coronary artery disease, and peripheral vascular disease was significantly lower among patients in group 3 in comparison to groups 1 and 2 . There were 155 episodes of peritonitis during the study period for an overall rate of 1 episode in 18.7 patient-months . The overall, gram-positive, and gram-negative rates of peritonitis were not significantly different among the patients in groups 1, 2, and 3 . There were more episodes of Staphylococcus aureus peritonitis among patients in group 3 in comparison to group 2 (1 episode in 59.6 vs 1 episode in 280.2 patient-months, respectively) . Two weeks after the development of peritonitis, 94.6% of the patients in group 3 continued CPD therapy, while 79.4% of the patients in group 1 continued CPD therapy (p < 0.05) . No patient in group 3 transferred to hemodialysis, while 10.3% and 8.2% of the patients in groups 1 and 2 transferred to hemodialysis (p < 0.05) . The death rate 2 weeks after the onset of peritonitis was 10.3%, 9.8%, and 5.4% in groups 1, 2, and 3, respectively (p = NS) . CONCLUSIONS: Despite the immunological and morphological changes that occur in the peritoneal cavity with increased time on CPD therapy, there was no difference in the overall, gram-positive, or gram-negative rates of peritonitis for patients maintained on CPD therapy for various time periods . Patients in group 3 continued CPD therapy more often than did patients in group 1 . Patients in group 3 transferred to hemodialysis less often than did the remaining patients in the study period . The incidence of death was not significantly different for the three groups of patients.

Crit Care Med, 1999 Sep, 27(9), 1908 - 15
Effect of short-term enteral feeding with eicosapentaenoic and gamma-linolenic acids on alveolar macrophage eicosanoid synthesis and bactericidal function in rats; Palombo JD et al.; OBJECTIVES: Because vasoactive eicosanoids derived from arachidonic acid present in immune cell phospholipids promote lung inflammation in critically ill patients, novel experimental diets containing eicosapentaenoic acid from fish oil and gamma-linolenic acid from borage oil have been designed to limit arachidonic acid metabolism . However, excess dietary eicosapentaenoic acid impairs superoxide formation and bacterial killing by immune cells . The present study determined whether short-term enteral feeding with diets enriched with either eicosapentaenoic acid alone or in combination with gamma-linolenic acid would modulate alveolar macrophage eicosanoid synthesis without compromising bactericidal function . DESIGN: Prospective, randomized, controlled, blinded study . SETTING: University medical center . SUBJECTS: Adult male Sprague-Dawley rats . INTERVENTIONS: Rats underwent surgical placement of a gastroduodenal feeding catheter and were randomly assigned to receive one of three high-fat (55.2% of total calories), low-carbohydrate diets containing isocaloric amounts of lipids for 4 days . The control diet was enriched with linoleic acid, whereas the two test diets were low in linoleic acid and enriched with either 5 mole % eicosapentaenoic acid alone or in combination with 5 mole % gamma-linolenic acid . Alveolar macrophages were then procured to assess phospholipid fatty acid composition, eicosanoid synthesis after stimulation with endotoxin, superoxide formation and phagocytosis by flow cytometry, and killing of Staphylococcus aureus MEASUREMENTS AND MAIN RESULTS: Alveolar macrophage levels of arachidonic acid were significantly (p < .01) lower and levels of eicosapentaenoic and dihomo-gamma-linolenic acids were higher after feeding the eicosapentaenoic and gamma-linolenic acid diet vs . the linoleic acid diet . Ratios of thromboxane B2,/B3, leukotriene B4/B5, and prostaglandin E2/E1 were reduced in the macrophages from rats given either the eicosapentaenoic acid or eicosapentaenoic acid with gamma-linolenic acid diet compared with ratios from rats given the linoleic acid diet . Macrophages from rats given the eicosapentaenoic with gamma-linolenic acid diet released 35% or 24% more prostaglandin E1 than macrophages from rats given either the linoleic acid or the eicosapentaenoic acid diet, respectively . Macrophage superoxide generation, phagocytosis of opsonized zymosan, and killing of S . aureus were similar irrespective of dietary treatment . CONCLUSION: Short-term enteral feeding with an eicosapentaenoic acid-enriched or eicosapentaenoic with gamma-linolenic acid-enriched diet rapidly modulated the fatty acid composition of alveolar macrophage phospholipids, promoted a shift toward formation of less inflammatory eicosanoids by stimulated macrophages, but did not impair alveolar macrophage bactericidal function relative to responses observed after feeding a linoleic acid diet.

Pathol Int, 1999 Jul, 49(7), 672 - 5
Marked histiocytosis in the portal tract in a patient with reactive hemophagocytic syndrome: An autopsy case; Terada T et al.; We report an autopsy case of reactive hemophagocytic syndrome with peculiar liver histology . A 71-year-old female was diagnosed as having acute myelogenous leukemia and treated with chemotherapy . During her course, methicillin-resistant Staphylococcus aureus (MRSA) was noted in blood culture and she was diagnosed as having MRSA sepsis . She died of respiratory failure 5 months after the onset of leukemia and 10 days after the MRSA sepsis . Ante-mortem liver function tests were within normal ranges . At autopsy, myeloblastic leukemia cells positive for CD13 were present in the bone marrow and, to a much lesser extent, in the spleen and liver . Numerous histiocytes of a bland appearance with erythrophagocytosis were noted in the bone marrow and spleen . The histiocytes were positive for CD68, but negative for S-100 and lysozymes . In the liver, many histiocytes of bland appearance with erythrophagocytosis and CD68 positivity were present in the portal tracts with no Kupffer cell hyperplasia . There were no hepatocellular degeneration, fatty changes or sinusoidal dilations . We consider that this histiocytosis was associated with MRSA infection and diagnosed this as infection-associated hemophagocytic syndrome . In previously reported cases, hemophagocytosis in hyperplastic Kupffer cells was the main liver change of reactive hemophagocytic syndrome . The present case suggests that marked histiocytosis in portal tracts only may be a main feature of liver changes in reactive hemophagocytic syndrome and that such cases may not show abnormal liver function tests.

Nippon Jinzo Gakkai Shi, 1999 Aug, 41(5), 505 - 10
{A case of non-Hodgkin's lymphoma presenting with acute renal failure diagnosed by renal biopsy}; Yaomura T et al.; We report a case of non-Hodgkin's lymphoma (NHL) presenting with acute renal failure . A-56-year-old male was admitted to our hospital on October, 1997 with fever and renal dysfunction . Physical examination showed no abnormality except for hepatomegaly . Body surface lymphadenopathy was not observed . Computed tomography (CT) of the abdomen showed markedly enlarged kidneys bilaterally and a mass of soft tissue density, which was considered as a swelling lymph node, around the aortic artery . The renal biopsy revealed parenchymal involvement of the NHL cells without normal tubulo-interstitial structure, but the glomeruli were almost intact . Our case rapidly fell into oliguria and acute renal failure, hence needed hemodialysis . After chemotherapy was performed, his renal function gradually improved and the kidney became smaller on subsequent CT . Unfortunately, the patient happened to suffer from methicillin-resistant staphylococcus aureus (MRSA) infection in a neutropenic state and died . Necropsy revealed recovery of the renal interstitium without residual NHL cells . Renal lymphoma without any other organ or nodal involvement is a rare type of NHL, which considered primary renal lymphoma (PRL) . However, we believe this case to have been a result of lymphomatous infiltration of the kidneys in disseminated lymphoma.

Infect Control Hosp Epidemiol, 1999 Sep, 20(9), 604 - 6
Prospective evaluation of a hospital epidemiologist's activities at a European tertiary-care medical center; Ruef C; OBJECTIVE: Assessment of the distribution of tasks and consultations provided by the hospital epidemiologist (HE) at University Hospital of Zurich (UHZ) . DESIGN: Prospective collection of data on hospital epidemiology consultations over a 3-year period (1995-1997) . Time spent per consultation and activities of infection control practitioners were not recorded . SETTING: A 1,040-bed tertiary-care university hospital in Zurich, Switzerland . RESULTS: Between January 1, 1995, and December 31, 1997, the HE received 1,660 requests for consultation . Advice or action was sought in the following areas: epidemiology (27.5% of requests); quality assurance, including antibiotic utilization and technology assessment (24.8%); infection control and practice guidelines (22.5%); disinfection and sterilization (11.6%); clinical infectious diseases (13.4%) . During 1997, 35% of epidemiology consults were related to methicillin-resistant Staphylococcus aureus and 5.8% to tuberculosis . Public or private hospitals not affiliated with UHZ requested 40% of all consults . CONCLUSIONS: This study shows that HEs are involved in many different activities . Only 27.5% of hospital epidemiology consultations were directly related to issues of epidemiology . Practical knowledge of the methodologies for continuous quality improvement and assessment of various new technologies is important for HEs . The results of this study may be useful in discussions between HEs and administrators about allocation of resources or issues of reimbursement.

In Vitro Cell Dev Biol Anim, 1999 Sep, 35(8), 472 - 80
Staphylococcus aureus adherence to nasal epithelial cells in a physiological in vitro model; Hoefnagels-Schuermans A et al.; Nasal carriage of Staphylococcus aureus represents a risk factor for subsequent invasive infections and interpatient transmission of strains . No physiological in vitro model of nasal epithelial cells is available to study both patient- and bacteria-related characteristics and their interaction, leading to adherence and colonization . Starting with tissues from human nasal polyps, a confluent, squamous, nonkeratinized epithelium in collagen-coated 96-well microtiter plates was obtained after 14 d . This in vitro cell-layer was characterized histologically, ultrastructurally, and immunohistochemically and showed features that were indistinguishable from those observed in the squamous nonkeratinized epithelium found in the posterior part of the vestibulum nasi . Adherence experiments were performed with four different 3H-thymidine-labeled Staphylococcus aureus strains . The effect of bacterial inoculum size, temperature of incubation, and incubation medium were studied . The adherence results were found to be reproducible, reliable and sensitive, allowing detection of small quantitative differences in adherence between the Staphylococcus aureus strains . There was no significant difference in adherence at 23 degrees C and 37 degrees C, nor between the incubation medium M199 and phosphate-buffered saline . Plastic adherence could be reduced and standardized with use of siliconized tips and a constant bacterial inoculum volume of 100 microl/well . This physiological and reliable in vitro cell-culture model offers a unique opportunity to study Staphylococcus aureus adherence to squamous, nonkeratinized nasal epithelial cells and both patient and bacterial characteristics involved in this interaction.

FEMS Microbiol Lett, 1999 Sep 15, 178(2), 271 - 5
Proteolytic cleavage of the repressor (BlaI) of beta-lactamase synthesis in Staphylococcus aureus; Lewis RA et al.; The proteolytic cleavage of BlaI was shown to correlate with beta-lactamase synthesis in Staphylococcus aureus . BlaI was found to be autoregulatory when expressed from the blaZ promoter . Insertion of a 10-bp linker into the SnaBI site of blaRI resulted in constitutive synthesis of beta-lactamase.

J Bacteriol, 1999 Oct, 181(19), 6184 - 7
4,4'-diapophytoene desaturase: catalytic properties of an enzyme from the C(30) carotenoid pathway of Staphylococcus aureus; Raisig A et al.; Staphylococcus aureus synthesizes C(30) carotenoids . Their formation involves the introduction of three double bonds, which is catalyzed by a single enzyme . This enzyme, 4,4'-diapophytoene desaturase from S . aureus, was overexpressed in Escherichia coli and purified in one step by affinity chromatography, and then the protein was characterized with respect to substrate specificity, cofactor requirement, and oligomerization.

J Bacteriol, 1999 Oct, 181(19), 5909 - 14
Expression of the Staphylococcus aureus UDP-N-acetylmuramoyl- L-alanyl-D-glutamate:L-lysine ligase in Escherichia coli and effects on peptidoglycan biosynthesis and cell growth; Mengin-Lecreulx D et al.; The monomer units in the Escherichia coli and Staphylococcus aureus cell wall peptidoglycans differ in the nature of the third amino acid in the L-alanyl-gamma-D-glutamyl-X-D-alanyl-D-alanine side chain, where X is meso-diaminopimelic acid or L-lysine, respectively . The murE gene from S . aureus encoding the UDP-N-acetylmuramoyl-L-alanyl-D-glutamate: L-lysine ligase was identified and cloned into plasmid vectors . Induction of its overexpression in E . coli rapidly results in abnormal morphological changes and subsequent cell lysis . A reduction of 28% in the peptidoglycan content was observed in induced cells, and analysis of the peptidoglycan composition and structure showed that ca . 50% of the meso-diaminopimelic acid residues were replaced by L-lysine . Lysine was detected in both monomer and dimer fragments, but the acceptor units from the latter contained exclusively meso-diaminopimelic acid, suggesting that no transpeptidation could occur between the epsilon-amino group of L-lysine and the alpha-carboxyl group of D-alanine . The overall cross-linking of the macromolecule was only slightly decreased . Detection and analysis of meso-diaminopimelic acid- and L-lysine-containing peptidoglycan precursors confirmed the presence of L-lysine in precursors containing amino acids added after the reaction catalyzed by the MurE ligase and provided additional information about the specificity of the enzymes involved in these latter processes.

J Trauma, 1999 Sep, 47(3), 551 - 4
Anterior mediastinal abscess after closed sternal fracture; Cuschieri J et al.; BACKGROUND: Although sternal fractures after blunt chest trauma are markers for significant impact, the fracture itself is generally not associated with any specific wound complications . Mediastinal abscess and sternal osteomyelitis rarely occur after blunt trauma or cardiopulmonary resuscitation . Management of such complications is difficult, and requires a spectrum of operative procedures that range from simple closure to muscle flap reconstruction . METHODS: The trauma registry of a Level I trauma center was used to identify patients suffering a sternal fracture between January of 1994 and August of 1997 . Records were reviewed for the mechanism of injury, length of hospital stay, and posttraumatic mediastinal abscess . RESULTS: Twenty-six patients were identified with sternal fracture . No clinically significant cardiac or aortic complications were noted . Three patients, all with a history of intravenous drug abuse and requiring central venous access in the emergency room, developed methicillin resistant Staphylococcus aureus mediastinitis . Sternal re-wiring and placement of an irrigation system successfully treated all three patients . CONCLUSION: Posttraumatic mediastinal abscess is an uncommon complication of blunt trauma in general and sternal fracture in particular . It can be recognized by the development of sternal instability . Risk factors include the presence of hematoma, intravenous drug abuse, and source of staphylococcal infection . Treatment with early debridement and irrigation can avoid the need for muscle flap closure.

South Med J, 1999 Sep, 92(9), 909 - 11
Smitten by a kitten; Israeli E et al.; Mammalian bite wounds are commonly encountered in the emergency department . When patients come early (<8 hours after injury), local infection is not usually evident . At this stage, the issue of providing prophylactic antibiotic therapy arises . We report a complication of a cat bite to the hand in a previously healthy 32-year-old man . This patient did not seek medical treatment immediately after the cat bite, and distinct local infection did not develop . Nevertheless, his course was complicated with acute Staphylococcus aureus endocarditis . We discuss the common pathogens involved in a cat bite infection, including S aureus, and delineate the indications for prophylactic antibiotic therapy after a mammalian bite wound.

Infect Immun, 1999 Oct, 67(10), 5541 - 4
Alpha-toxin damages the air-blood barrier of the lung in a rat model of Staphylococcus aureus-induced pneumonia; McElroy MC et al.; We have shown that injury to alveolar epithelial type I cells may account, in part, for damage to the air-blood barrier of the lung in a rat model of Staphylococcus aureus pneumonia . We have also shown that alpha-toxin is an important cause of damage to the air-blood barrier; however, our data suggest that the toxin is not acting directly on alveolar type I cells.

Infect Immun, 1999 Oct, 67(10), 5001 - 6
Development and characterization of a Staphylococcus aureus nasal colonization model in mice; Kiser KB et al.; Staphylococcus aureus nasal carriage is a risk factor for infection in humans, particularly in the hospital environment . Attenuation of carriage has proven effective in reducing the prevalence of infection in some high-risk groups . To study staphylococcal factors that influence nasal colonization, a mouse model of S . aureus nasal colonization was developed . Mice were inoculated intranasally with S . aureus Reynolds, and nasal carriage was evaluated by quantitating cultures of the nasal tissues from mice sacrificed at various time points after inoculation . The majority of mice inoculated with 10(8) CFU of S . aureus maintained nasal carriage for at least 20 days . Nasal colonization rates were similar for inbred (BALB/c and C57BL/6) and outbred (ICR) mice . Colonization was not affected by mouse passage of strain Reynolds . Lower inoculum doses (<10(7) CFU) resulted in reduced colonization after 7 days . However, mice given streptomycin in their drinking water developed long-term carriage of S . aureus, and they were colonized with inocula as low as 10(5) CFU . Nasal colonization was also established with two other S . aureus strains (one strain each of human and murine origins) . S . aureus recovered from the nares of experimentally colonized mice expressed high levels of capsule, and the ability of a capsule-defective mutant to persist in the nares was reduced in comparison to that of the parent strain . This nasal colonization model should prove useful for studies of factors that mediate S . aureus colonization and for assessment of targets for antimicrobial intervention or vaccine development.

Jpn J Thorac Cardiovasc Surg, 1999 Aug, 47(8), 368 - 76
Computerized antibiogram for methicillin-resistant Staphylococcus aureus in chest surgery; Yoshida J et al.; BACKGROUND: An increasing number of cases of postoperative morbidity involving methicillin-resistant Staphylococcus aureus have been reported in thoracic surgery . To prevent its outbreak, cluster analysis using a personal computer was employed . METHODS: A total of 120 patients undergoing operations on the lung and mediastinum were included into this study . Materials were isolates of methicillin-resistant Staphylococcus aureus newly recovered from across the hospital . The cluster analysis used antimicrobial susceptibility in 12 drugs, which were categorically valued to produce Euclidean distance to form clusters of similarity . RESULTS: Six of the 120 patients were found to be positive for the microbe before or after thoracotomy . A total of two patients (1.7%) became symptomatic postoperatively, i.e., one of four preoperatively-positive patients and one of two postoperatively-positive cases . The analysis suggested that preoperative patients shared the strains in the same non-surgical ward . DISCUSSION: A computerized antibiogram does not always strictly type Staphylococcal strains but has advantages in typing with ease and at decreased cost . The current analysis suggested that patient harboring the strains migrated across wards . CONCLUSION: Computerized antibiograms for Staphylococcal strains may assist to prevent an outbreak of their infection in chest surgery.

Rev Soc Bras Med Trop, 1999 Jul-Aug, 32(4), 395 - 400
{A longitudinal study of healthy Staphylococcus aureus carriers among the students of a nursing aide course}; Santos BM; The objective of the present study was to determine the extent of colonization by Staphylococcus aureus and the evolution of carrier status among students of a technical nursing course during their professional training . Forty students participated in the study, samples were collected from their nasal cavity and right and left hands at six different times during the technical nursing course . Nineteen students (45.2%) were found to be occasional carriers, 12 (28.6%) were intermittent carriers, 6 (14.3%) were persistent carriers, and 5 (11.9%) were non-carriers, showing that colonization did not increase during the course . Twenty-four of them (57.1%) did not perform activities related to nursing before or during the course, whereas 18 (42.9%) performed them.

Acta Derm Venereol, 1999 Sep, 79(5), 360 - 2
Bactericidal activity of manganese and iodide ions against Staphylococcus aureus: a possible treatment for acute atopic dermatitis; Inoue T et al.; We reported previously that balneotherapy using Kusatsu hot-spring water is useful for controlling the skin symptoms of acute flares/exacerbations of refractory cases of atopic dermatitis . As Staphylococcus aureus on the skin surface decreased in number or disappeared after balneotherapy, the hot-spring water was suspected to act against the microorganism . The hot-spring water showed strong bactericidal activity against S . aureus in vitro . In order to clarify the mechanism further, the bactericidal activity of the hot-spring water was examined by adding back cations and anions in same concentrations as those in the original hot-spring water, one at a time to cation- and anion-exchanged hot-spring water . The findings clearly demonstrated that the bactericidal activity was expressed by manganese and iodide ions in acidic conditions (pH 2.0-3.0) . Thus, the probable mechanism for the improvement of skin manifestations through Kusatsu balneotherapy is the bactericidal activity of the hot-spring water against S . aureus . When added to water acidified with sulphuric acid (pH 2.0-3.0) a synergistic effect of the 2 ions was observed, so that an anti-staphylococcal effect was obtained even at low concentrations (1 mg/kg) . Acidic solutions containing manganese and iodide ions may thus be clinically useful for treating skin conditions caused by S . aureus.

J Neurosurg Sci, 1999 Mar, 43(1), 63 - 7
Cervical spinal epidural abscesses . A report on five cases; Piccolo R et al.; The authors report a series of five cases of non tuberculous cervical spinal epidural abscesses . There were neither patients suffering from immunodeficiency syndromes nor drug addicts; all the patients were in their seventh decade; two patients were affected by diabetes mellitus refractory to medical treatment . Retropharyngeal abscess was the main etiological risk factor (two cases); Staphylococcus aureus was cultured in two cases . Gadolinium MRI was necessary for a preoperative diagnosis, planning surgical approach and postoperative prognosis . Surgical debridement was performed via an anterior approach in those cases where the collection was located lower than C4 and did not span more than three vertebral segments; posterior approach, via a laminectomy, was performed in a case of C1-C2 location of the lesion and in a case of involvement of the whole cervical spine . Surgical results were poor in those patients affected by diabetes mellitus, a lesion involving the high cervical segments (higher than C4) or a lesion spanning more than three levels . Medical treatment with MRI follow-up was not undertaken in any of the patients and we opted for surgical drainage in all the cases due to the possibility of a sudden neurological deterioration, caused both by spinal cord mechanical compression and vascular compromission.

Biochemistry, 1999 Sep 21, 38(38), 12296 - 304
Cooperative structural dynamics and a novel fidelity mechanism in histidyl-tRNA synthetases; Qiu X et al.; The crystal structure of the Staphylococcus aureus histidyl-tRNA synthetase apoprotein has been determined at 2.7 A resolution . Several important loops in the active site either become disordered or adopt very different conformations compared to their ligand-bound states . These include the histidine A motif (Arg257-Tyr262) that is essential for substrate recognition, a loop (Gly52-Lys62) that seems to control the communication between the histidine and ATP binding sites, the motif 2 loop (Glu114-Arg120) that binds ATP, and the insertion domain that is likely to bind tRNA . These ligand-induced structural changes are supported by fluorescence experiments, which also suggest highly cooperative dynamics . A dynamic and cooperative active site is most likely necessary for the proper functioning of the histidyl-tRNA synthetase, and suggests a novel mechanism for improving charging fidelity.

Vestn Khir Im I I Grek, 1999, 158(1), 45 - 8; discussion 48-9
{The information value of the biological properties of the causative agent in the prognosis of the duration of the course of suppurative inflammatory diseases of staphylococcal etiology}; Deriabin DG et al.; The informative value of biological characteristics of Staphylococcus aureus reflecting the ability of microbes to inactivate certain factors of natural resistance (lysozyme, complement, immunoglobulins, bactericidal component of interferon) was established in determining the duration of the caused by them pyo-inflammatory diseases such as postinfection abscesses, lactation mastitis . On this basis the heterogeneous successive procedure of pattern recognition was used to develop algorithms allowing prognosis of the duration of pyo-inflammatory diseases of staphylococcal etiology in 84.6-94.4% of the patients after the quantitative and qualitative assessment of the biological properties of the pathogen with not less than 90% reliability.

Biochem Biophys Res Commun, 1999 Sep 24, 263(2), 301 - 7
Mechanism of antibacterial and degradation behavior of a chlorinated isoxazolylnaphthoquinone; Bogdanov PM et al.; The chemical stability of 3-chloro-2-hydroxy-(3, 4-dimethyl-5-isoxazolyl)-1,4-naphthoquinon-4-imine (ClQ(1)), a new potential antimicrobial agent was analyzed at different pH values by first-derivative spectroscopy . The degradation of ClQ(1) followed a pseudo-first-order kinetics in aqueous media at different pH values . The interaction of antibiotics with respiratory chain of Staphylococcus aureus generates superoxide anion, an oxygen radical capable of producing damage to the bacteria . The performed assays have demonstrated that ClQ(1) presents higher activity and toxic oxidant generation at pH 5.0 than at pH 7.5 . In addition, the antibacterial activity of other halogenated isoxazolylnaphthoquinones was also studied in different collection and clinical strains which presented the following decreasing activity, ClQ(1) > BrQ(1) > DClQ(1) whereas DBrQ(1) did not show inhibition properties . The antibacterial and stability properties evidenced by ClQ(1) are so important that must be taken into account when new alternative treatments against beta-lactamase-positive S . aureus strains are investigated .

Acta Crystallogr D Biol Crystallogr, 1999 Sep, 55 ( Pt 9), 1626 - 9
Crystal engineering: deletion mutagenesis of the 24 kDa fragment of the DNA gyrase B subunit from Staphylococcus aureus; Dale GE et al.; The 24 kDa fragment of DNA gyrase B from Staphylococcus aureus was expressed in Escherichia coli and purified for crystallization . Crystals of the wild-type protein grew in the presence of cyclothialidine but proved difficult to reproduce . In order to improve the crystallization, the flexible regions of the protein were deleted by mutagenesis . The mutant proteins were analyzed by differential scanning calorimetry and the most stable mutants produced crystals . It was possible to reproducibly grow single well defined crystals in the microbatch system which belonged to the space group C2 and diffracted isotropically to approximately 2 A resolution.

Eur Respir J, 1999 Jul, 14(1), 113 - 7
Exhaled nitric oxide in patients with Wegener's granulomatosis; Haubitz M et al.; In Wegener's granulomatosis (WG), a pathogenic role of infections, in particular of a chronic colonization of the nasal mucosa with Staphylococcus aureus, has been postulated . Nitric oxide (NO), which is thought to play a role in primary host defence and inflammation, is produced endogenously within the respiratory tract, mainly from the paranasal sinuses . In order to further characterize its role in WG, nasal and pulmonary NO excretion in WG patients in comparison to healthy volunteers was measured . Seventeen patients with WG were included in the study . Five patients had active disease (bloody rhinitis with ulceration and crusting) and immunosuppressive therapy (IST), and 12 were in remission (six with, and six without, IST) . S . aureus was found in the swabs of all patients with active WG and in three patients in remission . NO was measured in exhaled gas using a chemiluminescence analyser . The NO excretion rate in nasally sampled gas was significantly reduced (p<0.05) in patients with active WG ((mean+/-SD)102+/-100 nL x min(-1)) compared to healthy controls (299+/-13 nL x min(-1)), and patients in remission (281+/-86 nL x min(-1) with IST, 280+/-133 nL x min(-1) without IST) . Pulmonary NO excretion in active or nonactive WG patients did not significantly differ from that of healthy volunteers (48+/-21 nL x min(-1)) . These results demonstrate a reduced nasal NO excretion in active Wegener's granulomatosis . This may be caused by destruction and/or functional impairment of sinus epithelium . The reduced NO concentration may well compromise host defence in the upper airways, thus contributing to colonization with Staphylococcus aureus and further promoting Wegener's granulomatosis.

Plasmid, 1999 Sep, 42(2), 144 - 9
Rapid method for the identification of essential genes in Staphylococcus aureus; Xia M et al.; A strategy based on a vector host-dependent for autonomous replication, pSA3182, was utilized both for the rapid screening for Staphylococcus aureus genes essential for cell viability and for the introduction of specific polarity-neutral deletions in nonessential genes . The results obtained support the use of pSA3182 for both purposes .

Plasmid, 1999 Sep, 42(2), 134 - 8
Comparative analysis of staphylococcal plasmids carrying three streptogramin-resistance genes: vat-vgb-vga; Allignet J et al.; Several staphylococcal plasmids (26-45 kb) carry all three streptogramin-resistance (Sg(R)) genes, vat, vgb, and vga . Seven such plasmids harbored by independent strains belonging to three taxa (Staphylococcus aureus, S . simulans, and S . cohnii subsp . urealyticum) were compared and the deleted derivative of one of them, pIP680 (11.3 kb), carrying the three streptogramin-resistance genes was sequenced . The seven native plasmids had in common a 12.1-kb part cocarrying the three Sg(R) genes . Sequence analysis of pIP680 revealed that the simultaneous presence of these three genes has probably resulted from cointegration of two plasmids: (i) a pAMbeta1-like plasmid harboring vat-vgb and whose replication gene has been inactivated by an IS257 insertion and (ii) a functional vga plasmid whose replication is similar to that of two staphylococcal plasmids, pSX267 and pSK41 .

Mayo Clin Proc, 1999 Sep, 74(9), 885 - 9
Pseudo-outbreak of methicillin-resistant Staphylococcus aureus; Ender PT et al.; OBJECTIVE: To determine whether a high rate of methicillin-resistant Staphylococcus aureus at our institution was due to laboratory misclassification and to evaluate the effect of this misclassification . MATERIAL AND METHODS: We evaluated all S . aureus isolates identified at our institution during a 60-day period in 1997 . Automated susceptibility test results (using the Vitek system) from our clinical microbiology laboratory and an independent laboratory were compared with oxacillin agar screen plate results at both laboratories . Isolates with discordant results for susceptibility to oxacillin were tested by broth microdilution minimal inhibitory concentrations and for the presence of the mecA gene . RESULTS: Eighteen (72%) of the 25 organisms (obtained from 17 patients) found to be resistant to oxacillin by the Vitek system at our institution were susceptible by the oxacillin agar screen . Discordant isolates tested by broth microdilution minimal inhibitory concentrations and for the mecA gene were found to be oxacillin susceptible and mecA gene negative . Thus, at our hospital, almost three fourths of the organisms initially identified as methicillin-resistant S . aureus by the Vitek system were actually susceptible to oxacillin . This misclassification resulted in needless infection control measures and unnecessary vancomycin use . CONCLUSION: Hospitals that use only automated susceptibility testing for S . aureus should periodically validate their results with additional testing.

Z Naturforsch {C}, 1999 Jul-Aug, 54(7-8), 549 - 53
Synergism between ethanolic extract of propolis (EEP) and anti-tuberculosis drugs on growth of mycobacteria; Scheller S et al.; Ethanolic extract of propolis exerts a strong anti-bacterial activity, in addition to antifungal, antiviral and antiprotozoal properties . In previous studies from these laboratories we have demonstrated that the intensity of the bactericidal activity of EEP is correlated with the virulence of the mycobacteria tested, and that EEP has a synergistic effect with antibiotics on growth of staphylococcus aureus . In the present study we investigated whether the same synergism and correlation exists between EEP and some anti-tuberculosis drugs on tuberculosis mycobacteria with different degrees of virulence . Six standard strains and 11 wild strains of mycobacteria were exposed for 30 days to EEP, with or without streptomycin, rifamycin, isoniazid or ethambutol . Out of the 17 strains, 8 were resistant to at least two standard antibiotics, and were considered "multi-resistant strains" . The rest were either susceptible or resistant to only one of the antimycobacterial drugs . Antagonism was recorded only in one case, when Staphylococcus aureus were treated with a mixture of EEP and ethambutol, suggesting that a chemical bond could have been formed between this anti-tuberculosis antibiotic and one of the active components of the ethanol extract of propolis.

Zhonghua Gan Zang Bing Za Zhi, 1999 Jun, 7(2), 77 - 9
{Apoptosis of peripheral blood lymphocytes of patients with chronic hepatitis B and clinical significance}; Ji W et al.; OBJECTIVE: To explore the effects of apoptosis of peripheral blood lymphocytes (PBLs) of patients with chronic hepatitis B (CHB) on the persistent infection of hepatitis B virus (HBV) . METHODS: The PBLs of 15 patients with CHB were isolated and cultured with or without Staphylococcus aureus enterotoxin B (SEB; 0.2 mg/L), or in the presence or absence of recombinant HBcAg (rHBcAg; 1.0 mg/L) for 48 hours in vitro . After incubations, the cells were harvested by centrifugation and then apoptosis of the PBLs was studied by staining with fluorescent dyes YOPRO-1 and Hoechst33342 . RESULTS: The percentage of apoptotic cells of PBLs of patients with CHB was significantly higher than in normal controls (P < 0.01) in the presence or absence of SEB or rHBcAg, but the ratio of apoptotic cells in rHBcAg-stimulated PBLs of the patients was the highest, reaching (24.6 +/- 6.1)% . The patients with seropositive for HBeAg had higher percentage of apoptotic cells in their cultured PBLs than those with seronegative for HBeAg had, but the ratio of apoptotic cells in cultured PBLs of the patients with chronic heavy and severe hepatitis B was lower than that of the patients with chronic mild and moderate hepatitis B (P < 0.01) . CONCLUSION: Activation-induced cell death of PBLs of the patients with CHB may be related to persistent infection of HBV, and assay of apoptosis of PBLs of patients with CHB may provide valuable information about pathogenesis of CHB.

J Clin Microbiol, 1999 Oct, 37(10), 3411 - 4
Use of multiplex PCR to detect classical and newly described pyrogenic toxin genes in staphylococcal isolates; Monday SR et al.; Staphylococcus aureus may contain one or more genes that encode a variety of immunomodulatory pyrogenic toxins (PTs), including the staphylococcal enterotoxins and toxic shock syndrome toxin (TSST) . The PTs interact with several cellular targets to produce disease, such as food poisoning and toxic shock syndrome . At present, nine serologically distinct enterotoxins and one immunoreactive form of TSST have been identified and characterized . As isolates of S . aureus are further assessed, it is anticipated that this number will increase . To facilitate screening, a multiplex PCR was designed to simultaneously determine which of these 10 currently known PT genes an individual S . aureus isolate possesses . We show here, using S . aureus isolates with characterized PT phenotypes, that this novel PCR technique reliably detects each of the known PTs in a single reaction.

J Clin Microbiol, 1999 Oct, 37(10), 3198 - 203
Genotyping of epidemic methicillin-resistant Staphylococcus aureus phage type 15 isolates by fluorescent amplified-fragment length polymorphism analysis; Grady R et al.; Fluorescent amplified-fragment length polymorphism (FAFLP) analysis was investigated for its ability to identify and subtype isolates of an epidemic methicillin-resistant phage type of Staphylococcus aureus, EMRSA-15 . These isolates were also characterized by PCR-restriction fragment length polymorphism (PCR-RFLP) of the coagulase gene and pulsed-field gel electrophoresis (PFGE) . For FAFLP, DNA was double digested with restriction enzymes ApaI plus TaqI or EcoRI plus MseI . Site-specific adaptors were ligated to one or the other set of restriction fragments, and PCR amplification was carried out with adaptor-specific primers . Amplified fragments separated on an ABI 377 automated sequencer and analyzed with Genescan version 2.1 software generated FAFLP profiles for all the isolates . The presence or absence of fragments was scored, similarity coefficients were calculated, and UPGMA (unweighted pair group method using arithmatic averages) cluster analysis was performed . Either enzyme-primer combination readily differentiated EMRSA-15 from other methicillin-resistant S . aureus (MRSA) isolates and also revealed heterogeneity within the phage type . The discriminatory power of FAFLP was high . By combining both enzyme-primer data sets, 24 isolates were divided into 11 profiles . PCR-RFLP did not discriminate among these EMRSA-15 isolates . PFGE could discriminate well between isolates but was not as reproducible as FAFLP . All S . aureus and MRSA isolates in this study were typeable by FAFLP, which was easy to perform, robust, and reproducible, with evident potential to subtype MRSA for purposes of hospital infection control.

J Clin Microbiol, 1999 Oct, 37(10), 3133 - 40
Follow-up of Staphylococcus aureus nasal carriage after 8 years: redefining the persistent carrier state; VandenBergh MF et al.; Studies of Staphylococcus aureus nasal carriage have distinguished three carriage patterns: persistent, intermittent, and noncarriage . The criteria used to identify these carriage patterns have been inconsistent . In 1988 the S . aureus nasal carrier index, i.e., the proportion of nasal swab specimen cultures yielding S . aureus, was determined for 91 staff members of various departments of a large university hospital by obtaining weekly nasal swab specimens for culture over a 12-week period . Thirty-three (36%) persons had carrier indices of 0.80 or higher, 15 (17%) had indices between 0.1 and 0.7, and 43 (47%) had indices of zero . In 1995, 17 individuals with carrier indices of 0.80 or higher in 1988 were available for reexamination . For 12 (71%) of these individuals, S . aureus was again isolated from a single nasal swab, i.e., from each individual with a 1988 carrier index of 1.0 but from only half of those with indices below 1.0 . Genotyping (by randomly amplified polymorphic DNA analysis and pulsed-field gel electrophoresis) of all S . aureus strains showed that strains isolated from only three individuals, all with 1988 carrier indices of 1.0, in 1988 and 1995 showed genetic similarity . In conclusion, persistent S . aureus nasal carriage is a unique characteristic of a fraction of the population, and the attribute "persistent" should be confined to those individuals for whom serial nasal swab specimen cultures consistently yield S . aureus.

Int J Dermatol, 1999 Aug, 38(8), 582 - 6
Characteristics of bacterial skin infections in children compared to adults at a tertiary dermatologic center; Sugeng MW et al.; BACKGROUND: Bacterial skin infections in children and adults are caused by different organisms with different antimicrobial susceptibility . METHODS: A comparative retrospective study was carried out on 233 adults and 53 children with bacterial skin infections . Skin swab cultures and sensitivity tests were performed using standard methods . Statistical analysis was performed using the Pearson chi-squared and Fisher tests . A P value of < 0.05 was considered to be significant . RESULTS: Primary and secondary skin infections occurred in equal proportions in children, whereas secondary skin infections were more common in adults (70.8%) . Staphylococcus aureus was the main cause of skin infections, particularly in children (72.6%) . S . aureus in children and adults was highly susceptible to cloxacillin, cephalexin, chloramphenicol, neomycin, cotrimoxazole, and clindamycin, moderately susceptible to erythromycin, and insensitive to tetracycline, ampicillin, and penicillin . CONCLUSIONS: It is important to monitor the trends of bacterial infections and their antibiotic susceptibility as this can assist medical practitioners in their choice of antimicrobial therapy . Such monitoring will also help to detect the emergence of resistant bacterial strains and caution us to take care in the use of certain drugs.

J Biotechnol, 1999 Aug 20, 73(2-3), 181 - 4
Expression of a clone specific DNA sequence from Staphylococcus aureus in Escherichia coli; el-Adhami W; Staphylococcus aureus produces a large number of factors thought to contribute to virulence, although the precise role of some of these individual factors is not clearly defined . To investigate whether specific virulence factors might be responsible for the selection and dominance of certain genotypes of methicillin- and multiply resistant S . aureus (MRSA), the method of subtractive hybridisation was used to identify conserved DNA sequences associated with the clinical, clonal populations of S . aureus . The findings described in this report indicate that the method of subtractive hybridisation is a valuable tool to identify clone specific virulence factors, which might be of potential as diagnostic markers and as alternative vaccine targets.

Undersea Hyperb Med, 1999 Fall, 26(3), 169 - 74
Therapy with hyperbaric oxygen and cefazolin for experimental osteomyelitis due to Staphylococcus aureus in rats; Mendel V et al.; Hyperbaric oxygen (HBO2) is used as adjunctive therapy for chronic osteomyelitis, yet its efficacy remains controversial . A recently developed rat model for osteomyelitis due to Staphylococcus aureus was used to compare the results of treatment with HBO2, cefazolin, a combination of both, or no treatment . For the induction of tibial osteomyelitis, S . aureus was inoculated into the medullary cavity . Arachidonic acid was used as the sclerosing agent . With that procedure, an infection rate of 96% was attained . For long-term antibiotic treatment, a port system was developed and implanted . Hyperbaric treatment alone reduced the colony-forming units (CFU) from 2.9 x 10(6) to 6.2 x 10(5) x g(-1) of tibial bone . The effect on the infection was more pronounced with antibiotic therapy alone, 10.5 x 10(4) CFU per g of tibial bone were measured . However, changes were most marked using a 4-wk combination therapy consisting of HBO2 and an antibiotic agent . The colony count was 2.7 x 10(3) CFU . Each of the treatment modalities resulted in a significant therapeutic effect . The results not only demonstrated the effectiveness of HBO2 in the treatment of osteomyelitis, but revealed a potential additive effect with the combination of HBO2 and an antibiotic.

Am J Rhinol, 1999 Jul-Aug, 13(4), 273 - 7
Post-functional endoscopic sinus surgery methicillin-resistant Staphylococcus aureus sinusitis; Jiang RS et al.; Methicillin-resistant Staphylococcus aureus (MRSA) is a highly virulent bacterium that is difficult to eradicate . It has become a common nosocomial pathogen, but it also causes sporadic infections in some outpatients . Among 358 chronic sinusitis patients who received functional endoscopic sinus surgery (FESS) for treatment between July 1995 and June 1997 in our department, 18 were infected postoperatively by MRSA by the end of August 1997 . One patient was excluded because she received another nasal surgery, partial turbinectomy, and submucous resection of the nasal septum, after FESS . Most of 17 MRSA infected patients presented themselves with mucopurulent nasal discharge and/or nasal crust . The treatment was generally difficult because MRSAs were resistant to multiple antibiotics . When quinolone antibiotics were used to treat most patients, the improvement rate was 76.5% . We conclude that MRSA infections in post-FESS patients might affect the outcome of FESS.

Aust N Z J Ophthalmol, 1999 Jun-Aug, 27(3-4), 237 - 40
Detection of staphylococcal superantigens from contact-lens-induced inflammatory diseases; Zhu H et al.; PURPOSE: We investigated the correlation between the production of superantigens in Staphylococcus-aureus-induced ulcer and contact-lens-induced peripheral ulcer (CLPU) and infiltrative keratitis (IK) . METHODS: Twenty-five S . aureus strains used in the study were isolated either from CLPU cases (six), or IK events (13) or asymptomatic eyes (six) . A polymerase chain reaction (PCR) was employed to detect genes for superantigenic staphylococcal enterotoxins A-D, toxic shock syndrome toxin-1 and exfoliative toxins A and B . Reversed passive latex aggregation, enzyme-linked immunosorbent assay (ELISA) and immunoblot were used to examine the production of staphylococcal enterotoxins A-D and toxic shock syndrome toxin-1 . RESULTS: The frequency of the superantigenic genes was not significantly different among the clinical isolates when asymptomatic isolates were compared with the strains isolated from CLPU and IK events . ELISA and immunoblot showed non-specific protein cross-reactions . CONCLUSIONS: The results suggest that detection of superantigenic toxin genes in ocular strains of S . aureus by PCR is a specific, sensitive, rapid and inexpensive alternative to traditional immunological assays . The role, if any, of the S . aureus superantigens in the production of CLPU/IK remains uncertain.

Aust N Z J Ophthalmol, 1999 Jun-Aug, 27(3-4), 224 - 7
Effect of lysozyme on adhesion and toxin release by Staphylococcus aureus; Thakur A et al.; PURPOSE: Staphylococcus aureus is a common cause of ocular infection and inflammation . We hypothesized that potential for S . aureus to cause an ocular infection would be enhanced if these bacteria are able to adhere to the biomaterials used in contact lenses . In turn, bacterial adhesion could also be influenced by other factors, such as properties of contact lenses and the absorbance of some tear components . We investigated the effect of the tear protein lysozyme on S . aureus adhesion to contact lenses and its effect on production of toxins or enzymes . METHODS: Bacterial adhesion on contact lenses was determined by counting the total number of bacteria as well as viable bacteria on lysozyme-coated or non-coated lenses, and by counting bacteria grown in the presence or absence of lysozyme in the medium . Toxin and enzyme production was assessed by haemolysis and proteolysis assays . RESULTS: Our results indicate that adhesion was significantly increased in the presence of lysozyme, both in the medium and coated onto contact lenses (P=0.04) . The presence of lysozyme did not alter the production of alpha- or beta- toxins . However, the presence of lysozyme inhibited elastase activity . CONCLUSION: These results indicate that lysozyme deposition on contact lenses promoted S . aureus adhesion . The tear protein lysozyme might modify elastase activity and thus modulate the production of corneal degradation resulting from the action of this enzyme.

Surg Today, 1999, 29(8), 724 - 9
New methods of control against postoperative methicillin-resistant Staphylococcus aureus infection; Kusachi S et al.; The incidence of postoperative infections caused by methicillin-resistant Staphylococcus aureus (MRSA) in Japan has been increasing dramatically . In March 1990, we assigned special doctors in infection control (infection control doctor, ICD), and defined comprehensive controls against MRSA infection . A total of 3536 cases of digestive tract surgery performed at our department were studied during the period between September 1987 and August 1997 . We changed the use of antibiotics to prevent postoperative infection . Cefazolin (CEZ) was employed for surgery of the upper digestive tract, including esophagus, stomach, duodenum, and gallbladder . Cefotiam (CTM) was employed for surgery of the lower digestive tract, liver, and pancreas . In esophageal resection, the tracheal tube was extracted during the early postoperative period, and for cervical esophagogastroanastomosis, the autosuture was changed to layer-to-layer anastomosis . We have achieved successful control of postoperative MRSA infection, the incidence having decreased to 0.3% (9/2703) . In conclusion, our methods of control against postoperative MRSA infection implies that comprehensive measures of prevention, including the reviewed specification and usage of antibiotics and operation management, have been well implemented . This value is the lowest and the first of any domestic hospital or institute in Japan, suggesting a continued and significant decrease.

Mikrobiol Z, 1999 May-Jun, 61(3), 46 - 51
{The abdominal cavity microflora of children with appendicular peritonitis}; Veselyi SV; Specific features and variability of microflora have been investigated in 75 patients with appendicular peritonitis . The patients' age was from 2 to 15 . Forty-five (45) children had local peritonitis, 17, diffuse and 13 children had total peritonitis . Complications were found in 18 (49.5%) patients . Appendicular peritonitis in children was accompanied by the permanent competition and changes in microflora . Microbiological pattern depended on the process stage and varied during a rather short period . The abundance of microorganism species during local peritonitis was gradually replaced by the prevalence of Staphylococcus aureus and especially Escherichia coli under the spread inflammation . The change of microflora during post-operation period was observed in 21 patients (56.8%) . In 9 patients the change was detected on the 15th--3rd day after the operation . Complications were observed in 85.7% of patients with changed microflora in the post-operation period . A conclusion was made that the prescription of the optimal antibacterial schemes of peritonitis treatment in children should be made with the account of change of bacterial agents during pathological process.

Scand J Infect Dis, 1999, 31(3), 319 - 21
Primary psoas abscess due to Fusobacterium nucleatum; Smetana GW; A case of primary pyogenic psoas abscess due to Fusobacterium nucleatum is described . Clinicians must maintain a high index of clinical suspicion for the diagnosis of psoas abscess . Although Staphylococcus aureus accounts for most cases of primary psoas abscess, this report emphasizes the importance of bacteriological confirmation of the microorganism involved.

Pneumonol Alergol Pol, 1999, 67(1-2), 60 - 4
{A case of empyema after pneumonectomy caused by methicillin-resistant staphylococcus aureus infection treated successfully with local administration with vancomycin}; Kachel T et al.; A 55-year-old man underwent left pneumonectomy due to squamous cell carcinoma . Three weeks later bronchopleural fistula and pleural empyema with MRSA infection were recognized . Treatment was based on closed pleural drainage and antibiotic therapy . Initially patient was treated with trimethoprin-sulfamethoxazole and then vancomycin intravenously but empyema was not cured completely . Therefore repeated instillation of vancomycin into the empyema cavity was applied . After 6 days of treatment, culture studies of the pleural fluid became negative and drainage tube was removed 5 days later . We suggest that local administration of vancomycin is an effective method in postpneumonectomy empyema with MRSA infection.

Acta Med Port, 1999 Apr-Jun, 12(4-6), 169 - 76
{The diversity of Staphylococcus aureus strains isolated in a Lisbon hospital over a 4-year period}; Cristino JM et al.; Over a 4-year period, 2020 Staphylococcus aureus strains isolated in Santa Maria Hospital were studied, 26.3% of which were methicillin-resistant (MRSA) . The main specimens from which the strains were isolated included pus, blood and sputum/bronchial secretions . Isolation in blood cultures was the most common source among patients from medical units . Antimicrobial susceptibility studies showed that while in methicillin susceptible strains sensitivity to other antimicrobial agents (apart from penicillin resistance) was the rule, in MRSA strains there was resistance to most antibiotics . Only vancomycin was active against all strains . Phage typing showed that 75.5% of the strains were typable with phages at 100 x R.T.D . Among methicillin sensitive strains, a big diversity of phage patterns was observed, including phage groups I, II, III and V, as well as with phage association D11/95 . The large majority of MRSA strains were lysed by group III phages, although several distinct patterns were observed . Within these strains, lysis by groups II and V phages was not observed . Plasmid profiling was the least discriminant issue in the characterization of these micro-organisms because most of the strains harboured only one plasmid (or none) . These results showed that a dominant MRSA strain did not exist in this hospital, but rather several distinct strains . The importance, as well as the difficulties in controlling the spread of MRSA strains in the present conditions of high prevalence, are highlighted.

Microbiol Immunol, 1999, 43(6), 505 - 12
Quantification of phagocytosis in human neutrophils by flow cytometry; Heinzelmann M et al.; Phagocytosis represents a central element of the host response to microbial invasion . We describe a flow cytometric method for measuring the kinetics of phagocytosis of two bacteria by human polymorphonuclear leukocytes (PMNs) . Over a 60-min period, isolated human PMNs were exposed to Staphylococcus aureus (rapidly phagocytosed) and Klebsiella pneumoniae (slowly phagocytosed) . This method distinguished adherent from ingested bacteria by quenching fluorescein isothiocyanate-labeled extracellular bacteria with ethidium bromide . This further allowed the exclusion of dead, highly permeable, and subsequently bright-red fluorescent PMNs . Our experiments with two different bacteria, various PMN-to-bacteria ratios (1:1, 1:10, 1:100), and different individuals proved that 1) flow cytometric analysis is accurate and useful for characterizing phagocytosis, 2) adherent bacteria can be distinguished from ingested bacteria after quenching with ethidium bromide, and that 3) phagocytosis kinetics of two bacteria with different onsets of phagocytosis can be determined by flow cytometry and the assessment of a score that quantifies phagocytosis.

J Infect Dis, 1999 Oct, 180(4), 1370 - 3
Protection against Staphylococcus aureus sepsis by vaccination with recombinant staphylococcal enterotoxin A devoid of superantigenicity; Nilsson IM et al.; Staphylococcal exotoxins are virulence determinants in Staphylococcus aureus arthritis and septicemia . To assess the utility of enterotoxins as vaccine candidates for these diseases, a genetically modified staphylococcal enterotoxin A (SEA) that lacks superantigenic properties was used . Mice immunized with recombinant (r) SEA had significantly longer survival than control immunized mice and lost significantly less weight than the controls . Transfer of SEA-specific antibodies to naive mice resulted in good protection against death in staphylococcal sepsis . In vitro proliferative responses to SEA by naive lymphocytes were almost totally abolished on incubation with serum from rSEA but not with control antigen-immunized mice . These results suggest that immunization with rSEA devoid of superantigenic properties provides good protection against S . aureus sepsis . In addition, the data indicate that the protection is at least in part mediated by SEA neutralizing antibodies.

J Infect Dis, 1999 Oct, 180(4), 1365 - 9
Cross-reactive antibodies prevent the lethal effects of Staphylococcus aureus superantigens; Bavari S et al.; The exotoxins produced by Staphylococcus aureus, staphylococcal enterotoxins (SE) A-E and toxic shock syndrome toxin (TSST)-1, which are associated with serious diseases, including food poisoning and toxic shock syndrome, are termed superantigens (SAgs) . To examine whether common antigenic epitopes were present and whether vaccination with 1 bacterial SAg could protect against challenge with a different SE or TSST-1, mice were vaccinated with SEA, SEB, SEC1, or TSST-1 individually or in combination . Mice injected with a single toxin developed high antibody titers against other SAgs . Marked improvement in survival was observed when immunized mice were challenged with a heterologous toxin . Mice vaccinated with a mixture of toxins were fully protected against 1 or multiple toxin challenges, indicating no interference effects of multivalent vaccinations . More importantly, higher titers were found against each SAg with the multivalent vaccination than with injection with a single SAg . Thus, immunizations with 1 SAg can induce cross-protective antibodies to heterologous SAgs, and multicomponent vaccination can enhance antibody responses against each bacterial SAg.

Cell Transplant, 1999 Jul-Aug, 8(4), 405 - 11
Effectiveness of acidic oxidative potential water in preventing bacterial infection in islet transplantation; Miyamoto M et al.; At a number of points in the current procedures of islet isolation and islet culture after the harvesting of donor pancreata, microorganisms could potentially infect the islet preparation . Furthermore, the use of islets from multiple donors can compound the risks of contamination of individual recipients . Acidic oxidative potential water (also termed electrolyzed strong acid solution, function water, or acqua oxidation water), which was developed in Japan, is a strong acid formed on the anode in the electrolysis of water containing a small amount of sodium chloride . It has these physical properties: pH, from 2.3 to 2.7; oxidative-reduction potential, from 1,000 to 1,100 mV; dissolved chlorine, from 30 to 40 ppm; and dissolved oxygen, from 10 to 30 ppm . Because of these properties, acidic oxidative potential water has strong bactericidal effects on all bacteria including methicillin-resistant Staphylococcus aureus (MRSA), viruses including HIV, HBV, HCV, CMV, and fungi as a result of the action of the active oxygen and active chlorine that it contains . We conducted this study to evaluate the effect of acidic oxidative potential water irrigation on bacterial contamination on the harvesting of porcine pancreata from slaughterhouses for islet xenotransplantation by counting the number of pancreatic surface bacteria using the Dip-slide method, and on the results of islet culture; and to evaluate the direct effect on isolated islets when it is used to prevent bacterial contamination by the static incubation test and by morphological examination . Direct irrigation of the pancreas by acidic oxidative potential water was found to be very effective in preventing bacterial contamination, but direct irrigation of isolated islets slightly decreased their viability and function.

Radiology, 1999 Sep, 212(3), 687 - 92
Osteoid osteoma: CT-guided percutaneous resection and follow-up in 38 patients; Sans N et al.; PURPOSE: To reevaluate at medium term the results of computed tomography (CT)-guided percutaneous resection of osteoid osteomas . MATERIALS AND METHODS: Thirty-eight patients who had undergone treatment by means of this technique were reexamined with a mean follow-up of 3.7 years . The short- and medium-term clinical course and histologic features of the resection specimens were analyzed . RESULTS: The bone fragment could be analyzed in all cases, and the diagnosis of osteoid osteoma was confirmed in 28 patients (74%) . A different diagnosis was made in six patients: mucoid cyst, subchondral arthritic geode, fibrous dysplastic lesion, focal osteochondritis, or focal chronic osteomyelitis . Cure was obtained in 32 patients (84%), whatever the cause . Complications, generally minor and transient, were observed in nine patients (24%) . The most severe complications were two femoral fractures and one focal chronic osteomyelitis due to Staphylococcus aureus infection . CONCLUSION: The results of this study confirm the efficacy of percutaneous resection of osteoid osteomas and the possibility of using this method for successful treatment of other small bone lesions.

Radiol Med (Torino), 1999 Jun, 97(6), 467 - 71
{Chronic spondylodiscitis . Clinical aspects and imaging features}; Meneghello A et al.; INTRODUCTION: The diagnosis of a chronic inflammatory process involving the vertebral body and disk is often very difficult because patient's history, subjective symptoms and physical findings are often unconclusive . Thus imaging techniques play a decisive role . Radiography, tomography, CT and MR have different capabilities and limitations and provide different findings in spondylodiscitis . MATERIAL AND METHODS: We observed 18 cases of spondylodiscitis in the last three years . The responsible microbe, a Staphylococcus aureus from extraosseous sites, was found in two cases at blood culture . Small cell inflammatory infiltration was confirmed with CT-guided biopsy in one case, while the other cases were diagnosed based on constant chronic back pain, feveret, moderate neutrophile leukocytosis or increased erythrosedimentation speed, plus changes in radiographic patterns following antibiotic therapy . RESULTS: Plain radiography and tomography are the techniques of choice to detect or suspect the lesion, which is then studied with CT or MRI . Clear-cut irregularities and erosions on opposing vertebral bodies, reactive bone sclerosis and reduced disk space were typical signs in our series; nine patients presented irregular cavitations(s), like bone caries, surrounded by reactive sclerosis in the body near the frontal vertebral plate . CONCLUSIONS: Together with the imaging patterns of all cases, we studied in detail three cases, relative to physical findings and diagnostic techniques . We also compared the changes in chronic spondylodiscitis with those in intraspongious herniation, intervertebral osteochondritis and severe degenerative arthritis . Bone erosions on the anterior cortical surface of the vertebral body were seen in 50% of our cases and may represent a specific sign of chronic spondylodiscitis if the finding is confirmed in further studies.

Lik Sprava, 1999 Apr-May, (3), 79 - 82
{The development of a coagglutination reaction using staphylococcal peptidoglycan for the diagnosis of staphylococcal infection}; Pozur VK et al.; Our objective in this study was to develop and assess the diagnostic value of a coagglutination test with making use of peptidoglycane of Staphylococcus aureus in the identification of diseases of staphylococcal etiology . A total of 166 patients with diseases of staphylococcal etiology were examined . A test was elaborated of coagglutination with making use of peptidoglycane of Staphylococcus aureus for a differential identification of antibodies to peptidoglycan in healthy persons and patients with staphylococcosis.

Lik Sprava, 1999 Apr-May, (3), 42 - 4
{The effect of ecological and microbiological factors on the health status of pregnant women with pyelonephritis and on their newborn infants}; Iashchukevych MIe; An analysis was performed of history, course of pregnancy, parturition, and condition of the newborn babies in female patients with pyelonephritis depending on the microbiological factor and environmental situation in the zone of residence . The pregnant women living under adverse environmental conditions display high levels of endocrine, cardiovascular, gastrointestinal disorders, and of tonsillitis . In the majority of cases, pregnancy is noted to be complicated by anemia (76.7%) and fetoplacental incompetence (62.9%), with infants being born in asphyxia presenting with signs of hypotrophy, congenital infection . Of the above infants, 37% develop postnatal inflammatory conditions . Two variants were shown to play a part in the etiology of pyelonephritis: monoetiological one marked by predominance of Staphylococcus aureus and Escherichia coli and polyetiological variant characterized by predominance of Candida fungi, Staphylococcus aureus, and mycoplasma . Irrespective of the microbiological factor, the female patients with pyelonephritis demonstrated high levels of premature birth, had a history of infertility, and were presenting with genital and extragenital pathologies.

Nucleosides Nucleotides, 1999 Jun-Jul, 18(6-7), 1297 - 9
Detection of nucleic acids by cycling probe technology on magnetic particles: high sensitivity and ease of separation; Bhatt R et al.; Cycling Probe Technology (CPT) is a signal amplification system that allows detection of nucleic acid target sequences without target amplification . CPT employs a sequence specific chimeric probe, typically DNA-RNA-DNA, which hybridizes to a complementary target DNA sequence and becomes a substrate for RNase H . Cleavage occurs at the RNA internucleotide linkages and results in dissociation of the probe from the target, thereby making it available for the next probe molecule . This communication describes the use of oligonucleotides attached to solid supports for target capture and release followed by solution and solid phase cycling . Through the attachment of chimeric probes to Sera-Mag magnetic particles (SMP) a simple and effective method of separating the cleaved probe from non-cycled probe has been developed . By capturing the target DNA on particles and separating it from the extraneous non-specific DNA we are able to dramatically reduce background and thus discriminate between samples of Methicillin Resistant (MRSA) and Methicillin Sensitive (MSSA) Staphylococcus Aureus . We conjugated oligonucleotide probes to SMPs (approximately 1 um) and Nylon beads (NB) which were coated with ID Biomedical's proprietary coating materials (R, patent pending) . The general structure of the constructs is shown below: {table: see text}

Ophthalmic Res, 1999, 31(6), 446 - 51
Ofloxacin levels after intravitreal injection . Effects of trauma and inflammation; Ozturk F et al.; PURPOSE: This study was carried out to get an insight into the ofloxacin elimination after intravitreal injection in rabbits . We also studied the effects of trauma and inflammation on the vitreous ofloxacin levels after intravitreal injection of ofloxacin . METHODS: A penetrating eye injury in the right eye was inflicted on 24 rabbits and another 12 animals were used as control . A standardized intraocular inflammation was induced by intravitreal injection of a suspension of Staphylococcus aureus in half of the traumatized eyes . Ofloxacin (200 microg/0.1 ml) was injected into the midvitreous cavity of both traumatized and control right eyes, and samples were obtained at 2, 8, 24 and 48 h after injection . Drug concentrations were measured using high-pressure liquid chromatography analysis . RESULTS: Vitreous levels of ofloxacin were above the MIC(90) at 2 and 8 h in all groups for most of the common microorganisms causing endophthalmitis and also at 24 h in traumatized-infected eyes . At the second hour, the mean vitreous concentrations of ofloxacin both in traumatized and traumatized-infected eyes were lower than that in the control eyes (p < 0.05) . At 8 h, the mean vitreous concentrations of ofloxacin in the traumatized and in the traumatized-infected eyes were higher than that in the control eyes (p < 0.05) . At 24 h, the mean ofloxacin concentration was higher in the traumatized-infected eyes than that in control (p < 0.01) and traumatized eyes (p < 0.05), and also higher in the traumatized eyes than that in the control eyes (p < 0.05) . The mean ofloxacin concentrations in the traumatized and traumatized-infected eyes were significantly higher (p < 0.01) than those in the controls at 48 h . The elimination half-life of ofloxacin in the control eyes was 5.65 h and trauma and inflammation prolonged the half-life to 9.47 and 9 . 72 h, respectively . CONCLUSION: Clearance of ofloxacin is fast and appears to be reduced by trauma and inflammation . Therapeutic drug levels in traumatized-infected eyes were maintained up to 24 h . This may be an important pharmacokinetic advantage in treating endophthalmitis unless the dose used has local toxicity and allows a longer dose interval when the dose is repeated.

J Antimicrob Chemother, 1999 Aug, 44(2), 263 - 73
Treatment of hospitalized patients with complicated gram-positive skin and skin structure infections: two randomized, multicentre studies of quinupristin/dalfopristin versus cefazolin, oxacillin or vancomycin . Synercid Skin and Skin Structure Infection Group; Nichols RL et al.; Quinupristin/dalfopristin (Synercid), the first injectable streptogramin antibiotic available for the treatment of complicated gram-positive skin and skin structure infections, was compared with standard comparators (cefazolin, oxacillin or vancomycin) in one USA and one international trial . These two randomized, open-label trials of virtually identical design enrolled a total of 893 patients (450 quinupristin/dalfopristin, 443 comparator) . The majority of patients had erysipelas, traumatic wound infection or clean surgical wound infection . Staphylococcus aureus was the most frequently isolated pathogen in both treatment groups and polymicrobial infection was more common in the quinupristin/dalfopristin group than in the comparator group . The clinical success rate (cure plus improvement) in the clinically evaluable population was equivalent between the two treatment groups (68.2% quinupristin/dalfopristin, 70.7% comparator; 95% CI, -10.1, 5.1) despite a shorter mean duration of treatment for quinupristin/dalfopristin patients . In the bacteriologically evaluable population, by-patient and by-pathogen bacteriological eradication rates were somewhat lower for quinupristin/dalfopristin (65.8% and 66.6%, respectively) than for the comparator regimens (72.7% and 77.7%, respectively) . The lower bacteriological response rates in the quinupristin/dalfopristin group were, in part, due to a higher rate of polymicrobial infections and a higher incidence of patients classified as clinical failure, a category which included premature discontinuation of treatment because of local venous adverse events . The bacteriological eradication rate for quinupristin/dalfopristin was higher in monomicrobial infections than in polymicrobial infections (72.6% versus 63.3%, respectively), whereas the corresponding rate for the comparator regimens was lower for monomicrobial infections than polymicrobial infections (70.8% versus 83.1%) . This finding was not unexpected, since the spectrum of quinupristin/dalfopristin is focused on gram-positive pathogens and additional antibiotics to treat gram-negative bacteria were not required per protocol . The systemic tolerability of both treatment regimens was qualitatively similar . A higher rate of drug-related venous adverse events was reported for quinupristin/dalfopristin (66.2%) than for the comparator regimen (28.4%) . Premature discontinuation of study drug was primarily due to adverse clinical events for quinupristin/dalfopristin (19.1%), whereas the most common reason for discontinuation among those receiving the comparator regimens was treatment failure (11.5%) . Quinupristin/dalfopristin is an effective alternative for the treatment of hospitalized patients with complicated skin and skin structure infections due to quinupristin/ dalfopristin-susceptible gram-positive organisms, including methicillin- and erythromycin-resistant S . aureus.

J R Soc Med, 1999 Jun, 92(6), 283 - 5
Antibacterial activity of honey against strains of Staphylococcus aureus from infected wounds; Cooper RA et al.; The antibacterial action of honey in infected wounds does not depend wholly on its high osmolarity . We tested the sensitivity of 58 strains of coagulase-positive Staphylococcus aureus, isolated from infected wounds, to a pasture honey and a manuka honey . There was little variation between the isolates in their sensitivity to honey: minimum inhibitory concentrations were all between 2 and 3% (v/v) for the manuka honey and between 3 and 4% for the pasture honey . Thus, these honeys would prevent growth of S . aureus if diluted by body fluids a further seven-fold to fourteen-fold beyond the point where their osmolarity ceased to be completely inhibitory . The antibacterial action of the pasture honey relied on release of hydrogen peroxide, which in vivo might be reduced by catalase activity in tissues or blood . The action of manuka honey stems partly from a phytochemical component, so this type of honey might be more effective in vivo . Comparative clinical trials with standardized honeys are needed.

Appl Environ Microbiol, 1999 Sep, 65(9), 4134 - 40
Staphylococcal surface display of immunoglobulin A (IgA)- and IgE-specific in vitro-selected binding proteins (affibodies) based on Staphylococcus aureus protein A; Gunneriusson E et al.; An expression system designed for cell surface display of hybrid proteins on Staphylococcus carnosus has been evaluated for the display of Staphylococcus aureus protein A (SpA) domains, normally binding to immunoglobulin G (IgG) Fc but here engineered by combinatorial protein chemistry to yield SpA domains, denoted affibodies, with new binding specificities . Such affibodies, with human IgA or IgE binding activity, have previously been selected from a phage library, based on an SpA domain . In this study, these affibodies have been genetically introduced in monomeric or dimeric forms into chimeric proteins expressed on the surface of S . carnosus by using translocation signals from a Staphylococcus hyicus lipase construct together with surface-anchoring regions of SpA . The recombinant surface proteins, containing the IgA- or IgE-specific affibodies, were demonstrated to be expressed as full-length proteins, localized and properly exposed at the cell surface of S . carnosus . Furthermore, these chimeric receptors were found to be functional, since recombinant S . carnosus cells were shown to have gained IgA and IgE binding capacity, respectively . In addition, a positive effect in terms of IgA and IgE reactivity was observed when dimeric versions of the affibodies were present . Potential applications for recombinant bacteria with redirected binding specificity in their surface proteins are discussed.

J Antimicrob Chemother, 1999 Aug, 44(2), 193 - 9
Intracellular activity of trovafloxacin against Staphylococcus aureus; van den Broek PJ et al.; The effect of trovafloxacin on Staphylococcus aureus ingested by human granulocytes or monocytes was compared with that on S . aureus in cell-free medium . Maximum growth inhibition (E(R,max)) by the antibiotic was 0.530 log10/h for S . aureus within granulocytes, 0.912 log10/h for S . aureus within monocytes, and 1.830-1.916 log10/h for S . aureus in medium . EC50, the concentration at which 50% of the maximum growth inhibition is achieved, did not differ significantly under the conditions investigated . After inhibition of intracellular killing by granulocytes with sodium fluoride, the intracellular antibacterial activity of trovafloxacin was still less than that in medium . A 3.4 times higher concentration was needed to achieve the same effect on phagocytosed S . aureus as in cell-free medium . Trovafloxacin binds more strongly to granulocytes than to monocytes, the respective cellular concentrations being 10 and four times higher than that in medium . In conclusion, the activity of trovafloxacin against S . aureus ingested by human granulocytes or monocytes is less than that against S . aureus in cell-free medium and is not related to the cell-associated concentration . Intracellular conditions are not favourable for the antibacterial activity of trovafloxacin.

J Ethnopharmacol, 1999 Sep, 66(3), 339 - 42
Antimicrobial activity of xanthones from Calophyllum species, against methicillin-resistant Staphylococcus aureus (MRSA); Dharmaratne HR et al.; During the past 5 years, a considerable number of known and new xanthones from the Calophyllum species of Sri Lanka have been isolated and characterized . We have investigated the antimicrobial activity of Calophyllum xanthones, with a special reference to methicillin-resistant Staphylococcus aureus (MRSA) . These activity studies were carried out using the agar plate method . Calozeloxanthone, a xanthone which has been isolated from C . moonii and C . lankensis, showed the highest activity against methicillin-resistant S . aureus (MRSA) strains at a concentration of 8.3 microg/ml . Hence, calozeyloxanthone appears to hold promise as an antimicrobial agent in the treatment of infections with S . aureus, including methicillin-sensitive S . aureus (MRSA), and should be investigated further.

Poult Sci, 1999 Aug, 78(8), 1191 - 7
Biochemical and molecular characterization of erthromycin-resistant avian Staphylococcus spp . isolated from chickens; Nawaz MS et al.; The epidemiology of the two common erythromycin-resistant methylase (erm) genes ermC and ermA was analyzed in 12 coagulase-negative Staphylococcus spp . and 34 coagulase-positive Staphylococcus spp . isolated from chicken . Southern hybridization indicated that only 2 of the 12 coagulase-negative Staphylococcus spp . strains contained the ermC gene on the plasmid; 1 strain of Staphylococcus xylosus harbored the ermC gene on a 2.5-kb plasmid, and 1 strain of Staphylococcus cohnii harbored the gene on a 4.0-kb plasmid . Twelve of the 34 strains of Staphylococcus aureus contained the ermC gene . Eleven of these strains had the ermC gene on a 2.5-kb plasmid, and 1 strain had the gene on a 4.0-kb plasmid . Ten of the 12 coagulase-negative Staphylococcus spp . and 22 of the 34 coagulase-positive Staphylococcus spp . harbored the ermA gene exclusively on the chromosome . Two different ermA EcoRI restriction fragment length polymorphisms (RFLP) were identified . A majority of the isolates was found to have two chromosomal inserts (8.0- and 6.2-kb EcoRI fragments) of ermA . One strain of S . aureus had different chromosomal inserts (6.4- and 5.8-kb EcoRI fragments) of ermA . Our results indicate that either the ermC or ermA gene, homologous to those described in human isolates, was present in all avian Staphylococcus spp . and that ermA was the predominant gene in coagulase-negative and coagulase-positive avian Staphylococcus spp . The size and copy numbers of the ermA gene were different from its human counterpart.

Poult Sci, 1999 Aug, 78(8), 1116 - 25
The effect of a second dexamethasone treatment on turkeys previously challenged in an experimental Escherichia coli respiratory model of turkey osteomyelitis complex; Huff GR et al.; In two separate experiments, turkeys that had survived immunosuppression with dexamethasone (DEX) and air sac inoculation with low numbers of Escherichia coli at 5 wk of age were maintained until 13 wk of age, at which time they were given a second treatment with DEX . All mortalities and birds that were necropsied 8 and 15 d (Experiment 1) and 21 d (Experiment 2) after the last DEX injection were scored for air sacculitis/pericarditis and turkey osteomyelitis complex (TOC) . In both experiments, all of the lesions that characterize TOC were reproduced, including osteomyelitis of the proximal tibia, synovitis/tendonitis, abscesses in the soft tissues, and green liver . In Experiment 1, all mortalities after Day 7 had TOC lesions, whereas 44% of mortalities had green livers . Staphylococcus aureus was isolated from 90% of all TOC lesions cultured . In Experiment 2, the incidence of mortality, air sacculitis, TOC, and green liver as well as the heterophil:lymphocyte ratio were significantly higher in birds that had previously been treated with DEX but had never been challenged with E . coli than in birds that had survived both treatment with DEX and challenge with 25 or 50 cfu of E . coli . Staphylococcus aureus was isolated from 73% of TOC lesions cultured, whereas E . coli was isolated from only 5.4% of the lesions . These studies suggest that TOC incidence may be related to a stress-induced susceptibility to opportunistic infection.

Antimicrob Agents Chemother, 1999 Sep, 43(9), 2222 - 4
Introduction of a norA promoter region mutation into the chromosome of a fluoroquinolone-susceptible strain of Staphylococcus aureus using plasmid integration; Kaatz GW et al.; It has been postulated that a mutation 11 bp 3' to the -10 motif of the norA promoter is involved in the increased expression of the gene observed in some strains of Staphylococcus aureus exhibiting efflux-related fluoroquinolone resistance . Introduction of this mutation into the chromosome of a fluoroquinolone-susceptible strain by plasmid integration resulted in the minimum inhibitory concentrations of NorA substrates being increased, fluoroquinolone uptake being reduced, and norA expression being enhanced . Diffuse hybridization of norA and integrating vector probes at a similar molecular weight range, higher than that of the norA transcript, was observed in the integrant, suggesting the possibility of a plasmid-based promoter contributing to norA expression . The ratio of the quantity of this transcript, which was also observed in the parent strain of the integrant, to the quantity of primary norA transcript was 0.14, demonstrating that it was unlikely that this mRNA species contributed significantly to the results observed . It is more likely that the introduced promoter region mutation does affect the expression of norA.

Antimicrob Agents Chemother, 1999 Sep, 43(9), 2121 - 5
Characterization of fmtA, a gene that modulates the expression of methicillin resistance in Staphylococcus aureus; Komatsuzawa H et al.; FmtA is a factor which affects the methicillin resistance level in methicillin-resistant Staphylococcus aureus . Since FmtA has two of three conserved motifs which are typically found in penicillin-binding proteins (PBPs) and beta-lactamases, we investigated the penicillin-binding activity of recombinant FmtA and found no such activity . Immunoblotting analysis revealed that FmtA localizes in the membrane fraction . To investigate the function of FmtA, high-pressure liquid chromatography analysis of cell wall muropeptides was performed with an fmtA-inactivated mutant and its parent . The mutant showed a reduced cross-linking and partially reduced amidation of glutamate residues in the peptidoglycan of the mutant . The transcription of fmtA was dose dependently increased by the addition of beta-lactam antibiotics, fosfomycin, and bacitracin, while its transcription was not changed by the addition of vancomycin or tetracycline . These results reveal that Fmt is a membrane-located, non-penicillin-binding protein and that mutation of fmtA affects the cell wall structure, although its precise function is still unknown.

J Neurosurg, 1999 Sep, 91(3), 510 - 4
Endovascular occlusion of a carotid pseudoaneurysm complicating deep neck space infection in a child . Case report; Reisner A et al.; Pseudoaneurysm formation of the cervical internal carotid artery (ICA) is a rare, potentially lethal complication of deep neck space infection . This entity typically occurs following otolaryngological or upper respiratory tract infection . The pseudoaneurysm is heralded by a pulsatile neck mass, Homer's syndrome, lower cranial neuropathies, and/or hemorrhage that may be massive . The recommended treatment includes prompt arterial ligation . The authors present a case of pseudoaneurysm of the cervical ICA complicating a deep neck space infection . A parapharyngeal Staphylococcus aureus abscess developed in a previously healthy 6-year-old girl after she experienced pharyngitis . The abscess was drained via an intraoral approach . On postoperative Day 3, the patient developed a pulsatile neck mass, lethargy, ipsilateral Horner's syndrome, and hemoptysis, which resulted in hemorrhagic shock . Treatment included emergency endovascular occlusion of the cervical ICA and postembolization antibiotic treatment for 6 weeks . The patient has made an uneventful recovery as of her 18-month follow-up evaluation . Conclusions drawn.from this experience and a review of the literature include the following: 1) mycotic pseudoaneurysms of the carotid arteries have a typical clinical presentation that should enable timely recognition; 2) these lesions occur more commonly in children than in adults; 3) angiography with a view to performing endovascular occlusion should be undertaken promptly; and 4) endovascular occlusion of the pseudoaneurysm is a viable treatment option.

J Trop Pediatr, 1999 Aug, 45(4), 233 - 6
Primary staphylococcal pneumonia in young children: a review of 100 cases; Goel A et al.; Staphylococcus aureus (S . aureus) is responsible for a small proportion of acute respiratory infections in children . Nevertheless a high index of suspicion is required because of the potential for rapid progression, the need for antibiotics different to those routinely administered in the treatment of pneumonia, and the high incidence of complications . There are few data from developing countries . The objective of this retrospective review was to document the natural history of primary staphylococcal pneumonia at Red Cross Childrens' Hospital in Cape Town over a 7-year period (1989-1995) . Staphylococcal pneumonia was defined as acute pneumonia with microbiological evidence of S . aureus or with characteristic radiological features . One hundred patients were identified . The median age was 5 months, 78 patients being below one year of age . Cough and fever were present in almost all patients at the time of presentation . Tachypnoea, recession, dullness, and crepitations were commonly elicited signs . Initial chest radiographs revealed empyema, pleural effusion, or pyopneumothorax in 67 patients . A further 26 patients developed such changes on subsequent chest radiographs . Pneumatocoeles were identified in 37 patients--most of these were only noted on radiographs taken some days after admission . Microbiological confirmation was obtained in 92 cases . S . aureus was isolated in 23/98 blood cultures, 62/67 pleural aspirates, and from tracheal aspirates in 16 cases . Intercostal drains were inserted in 67 cases and 20 children underwent thoracotomy . The case fatality rate was 7 per cent . This study shows that primary staphylococcal pneumonia is chiefly a disease of infants . Symptoms and signs were similar as for other forms of acute pneumonia, although in the majority of cases chest radiographs taken at the time of admission suggested the diagnosis . Treatment with antibiotics and drainage of empyema resulted in a good outcome in the majority of cases.

Zentralbl Bakteriol, 1999 Jul, 289(3), 339 - 45
Extracellular product(s) of Staphylococcus aureus stimulate their own growth; Sakata N et al.; The effect of extracellular products obtained from culture supernatant of Staphylococcus aureus strain Cowan I on the bacterial growth was studied in a synthetic medium . Addition of the extracellular products to a fresh medium stimulated growth already after 2 h of incubation, with an approximately two-fold increase in cell density as compared to an unsupplemented medium, probably by promoting an initiation of growth accompanied by a reduction of the initial lag phase . The growth-stimulating effect was also monitored as an increase of adenosine triphosphate (ATP) in the bacterial culture during the different phases of growth.

Eur J Biochem, 1999 Aug, 263(3), 921 - 7
Expression and activity of cyclic and linear analogues of esculentin-1, an anti-microbial peptide from amphibian skin; Ponti D et al.; Esculentin-1 is a potent anti-microbial peptide present in minute amounts in skin secretions of Rana esculenta . It contains 46 amino-acid residues and a C-terminal disulfide bridge . We have explored the possibility of producing analogues of this peptide by recombinant expression in Escherichia coli of a fusion protein which is sequestered in inclusion bodies . The peptide of interest has been inserted at the N-terminus of the protein, from which it can be released by cyanogen bromide cleavage . The anti-microbial activities of the recombinant peptide as well as that of a mutant linear form devoid of the disulfide bridge are presented . The recombinant analogues retain the biological activity of the natural peptide, as tested with an inhibition zone assay against a variety of microorganisms . However, experiments on the rate of bacterial killing show that gram-negative bacteria are more sensitive to the peptides than the gram-positive bacterium, the effect of the cyclic peptide being in all cases faster than that of the linear molecule . Moreover, the activity against gram-negative bacteria for both peptides is not affected by salts, whereas the activity against Staphylococcus aureus is lost at high salt concentration.

Clin Exp Immunol, 1999 Sep, 117(3), 489 - 95
Infection of human endothelial cells with Staphylococcus aureus induces the production of monocyte chemotactic protein-1 (MCP-1) and monocyte chemotaxis; Tekstra J et al.; Bacterial infection coincides with migration of leucocytes from the circulation into the bacterium-infected tissue . Recently, we have shown that endothelial cells, upon binding and ingestion of Staphylococcus aureus, exhibit proinflammatory properties including procoagulant activity and increased intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) expression on the cell surface, resulting in hyperadhesiveness, mainly for monocytes . The enhanced extravasation of monocytes to bacterium-infected sites is facilitated by the local production of chemotactic factors . From another study we concluded that the locally produced chemokine MCP-1 is important in the recruitment of monocytes to the peritoneal cavity in a model of bacterial peritonitis . In the present study we investigated whether cultured human endothelial cells after infection with bacteria produce and release MCP-1, which in turn stimulates monocyte chemotaxis . We observed that endothelial cells released significant amounts of MCP-1 within 48 h after ingestion of S . aureus . This was dependent on the number and the virulence of the bacteria used to infect the endothelial cells . The kinetics as well as the amount of MCP-1 released by S . aureus-infected endothelial cells differed markedly from that released by endothelial cells upon stimulation with IL-1beta . Supernatant from S . aureus-infected or IL-1beta-stimulated cells promoted monocyte chemotaxis which was almost entirely abrogated in the presence of neutralizing anti-MCP-1 antibody, indicating that most of the chemotactic activity was due to the release of MCP-1 into the supernatant . Our findings support the notion that endothelial cells can actively initiate and sustain an inflammatory response after an encounter with pathogenic microorganisms, without the intervention of macrophage-derived proinflammatory cytokines.

Int J Occup Med Environ Health, 1999, 12(2), 123 - 6
Effects of microwave irradiation on bacteria attached to the hospital white coats; Kakita Y et al.; A test to sterilize pieces of cloths, which are the material of hospital white coats (doctors and nurses wears), by microwave irradiation in place of autoclaving was done using a commercial 2,450 MHz microwave oven . When pieces of cloths made of cotton (35%) and polyester (65%) were contaminated experimentally with Escherichia coli or Staphylococcus aureus and irradiated by microwave, the bacteria were killed quite rapidly according to almost first-order reaction kinetics . Only after a 20-sec irradiation, when the water content of cloths was decreased from the original 48% to 35%, the relative survivals of these bacteria fell to below 1% that of the non-irradiated control . The cloths were neither browned nor crisped, even after a 10-min irradiation of microwaves.

Biophys J, 1999 Sep, 77(3), 1498 - 506
Comparison of the biophysical properties of racemic and d-erythro-N-acyl sphingomyelins; Ramstedt B et al.; In this study stereochemically pure d-erythro-sphingomyelins (SMs) with either 16:0 or 18:1(cisDelta9) as the N-linked acyl-chain were synthesized . Our purpose was to examine the properties of these sphingomyelins and acyl-chain matched racemic (d-erythro/l-threo) sphingomyelins in model membranes . Liquid-expanded d-erythro-N-16:0-SM in monolayers was observed to pack more densely than the corresponding racemic sphingomyelin . Cholesterol desorption to beta-cyclodextrin was significantly slower from d-erythro-N-16:0-SM monolayers than from racemic N-16:0-SM monolayers . Significantly more condensed domains were seen in cholesterol/d-erythro-N-16:0-SM monolayers than in the corresponding racemic mixed monolayers, when {7-nitrobenz-2-oxa-1, 3-diazol-4-yl}phosphatidylcholine was used as a probe in monolayer fluorescence microscopy . With monolayers of N-18:1-SMs, both the lateral packing densities (sphingomyelin monolayers) and the rates of cholesterol desorption (mixed cholesterol/sphingomyelin monolayers) was found to be similar for d-erythro and racemic sphingomyelins . The phase transition temperature and enthalpy of d-erythro-N-16:0-SM in bilayer membranes were slightly higher compared with the corresponding racemic sphingomyelin (41.1 degrees C and 8.4 +/- 0.4 kJ/mol, and 39.9 degrees C and 7.2 +/- 0.2 kJ/mol, respectively) . Finally, d-erythro-sphingomyelins in monolayers (both N-16:0 and N-18:1 species) were not as easily degraded at 37 degrees C by sphingomyelinase (Staphylococcus aureus) as the corresponding racemic sphingomyelins . We conclude that racemic sphingomyelins differ significantly in their biophysical properties from the physiologically relevant d-erythro sphingomyelins.

J Food Prot, 1997 Jan, 60(1), 54 - 8
Influence of processing schemes on indicative bacteria and quality of fresh aquacultured catfish fillets; Fernandes CF et al.; Fresh aquacultured catfish fillets were obtained from three processors using different processing protocols in summer, autumn, winter, and spring and evaluated for microbial quality . Twenty freshly processed fillets were randomly selected and each fillet was placed in a sterile polyethylene bag . The fillets were transported on ice-pack overnight by air immediately after processing . Five fillets were randomly selected for microbial assays . Each fillet was weighed and an equal volume of sterile 0.1% peptone water at 0 to 1 degrees C was added aseptically . The fillet was massaged (or rinsed) for 120 s and the rinse was used to determine microbial quality . Aerobes (incubation at 35 degrees C for 48 h) and psychrotrophs (incubation at 20 degrees C for 96 h) were enumerated using 3M Petrifilm Aerobic Count plates . Escherichia coli (incubation at 35 degrees C for 24 to 48 h) and total coliforms (incubation at 35 degrees C for 24 to 48 h) were enumerated on 3M Petrifilm E . coli Count plates . Staphylococcus aureus counts were determined on Baird-Parker agar (incubation at 35 degrees C for 48 h) . Significant differences (P < or = 0.05) in aerobic, psychrotrophic, total coliform, E . coli, and S . aureus counts due to temperature effects during production and variations in processing protocols were observed . E . coli and S . aureus counts were significantly different during the four seasons . E . coli and S . aureus counts were high during summer and low during winter weather . There was a significant difference (P < or = 0.05) in aerobic, psychrotrophic, and total coliform counts among the three processors during warm weather; however, these differences were significantly (P < or = 0.05) reduced in cold weather.

Respir Med, 1999 Jun, 93(6), 416 - 23
beta 2-agonist-induced inhibition of neutrophil chemotaxis is not associated with modification of LFA-1 and Mac-1 expression or with impairment of polymorphonuclear leukocyte antibacterial activity; Silvestri M et al.; Patients with chronic obstructive lung disorders often show increased susceptibility to airway infections . As beta 2-adrenoceptor agonists, in addition to reversing the contractile response of bronchial smooth muscles, may inhibit a variety of inflammatory and immuno-effector cell functions, it is possible that these drugs interfere with host defence mechanisms . The present study was designed to test in vitro whether fenoterol, a short-acting beta 2-adrenoceptor agonist, could modify human blood neutrophil recruitment and antimicrobial activity . Pre-exposure to fenoterol significantly reduced neutrophil migration towards the complement component C5a, at concentrations ranging from 10(-7) M to 10(-5) M, or towards lipopolysaccharide, at a concentration of 10(-5) M (P < 0.05, each comparison) . In contrast, the drug (10(-8)-10(-5) M) did not significantly modify the increased expression of lymphocyte function-associated antigen (LFA-1, i.e . CD11a/CD18) the macrophage antigen-1 (Mac-1, i.e . CD11b/CD18) induced by N-formylmethionylleucylphenylalanine (fMLP) (P > 0.05, each comparison) . Finally, incubation of neutrophils with fenoterol (10(-8)-10(-5) M) did not significantly influence phagocytosis or intracellular killing of bacteria (Staphylococcus aureus) or H2O2 release induced by tetradecanoyl-phorbol-acetate (P > 0.1 for each comparison) . These results suggest that short-acting beta 2-adrenoceptor agonists, such as fenoterol, are able partially to reduce neutrophil recruitment in the airways without interfering with the processes involved in phagocytic activity against bacteria.

Clin Exp Rheumatol, 1999 Jul-Aug, 17(4), 447 - 52
Vertebral osteomyelitis in northern Spain . Report of 62 cases; Belzunegui J et al.; OBJECTIVE: The records of 62 patients with clinical and radiographic evidence of vertebral osteomyelitis and positive bacteriological diagnosis, seen between 1979 and 1996, were reviewed in order to gather data on the epidemiology and the clinical pattern displayed by patients with this condition in northern Spain . RESULTS: Staphylococcus aureus (15 cases), Mycobacterium tuberculosis (15 cases) and Brucella melitensis (13 cases) were the microorganisms most frequently found in our patient series . After improvement of the sanitary and hygienic control of food products, the role of Brucella melitensis is decreasing as a causative agent (only 3 cases in the last 6 years) . Staphylococcus epidermidis, present in 4 cases (6.6%), should be suspected in elderly patients with previous intravenous cannulations (3 of 4 cases) . The most frequent risk factors were alcoholism (7 cases), chronic hepatic disease (7 cases), diabetes (6 cases) and previous surgery (6 cases) . Delay in diagnosis was high (the mean number of days between the onset of symptoms and diagnosis was 125) . The lumbar region was the most commonly affected site . Neurologic involvement was present in 10 patients on admission (16%) . ESR was > 50 mm/hr in a high number of cases . Blood cultures were found to be the most valuable routine test . Plain x-rays were normal in 10 patients (16%); in 6 of them Staphylococcus aureus was the responsible organism . Other imaging modalities showed a high sensitivity . Surgical drainage was necessary in 12 individuals (in 7 due to Mycobacterium tuberculosis) . Outcome was good in the majority of cases: only 2 patients with associated endocarditis died . Neurologic sequelae were present in another 3 patients . CONCLUSION: Vertebral osteomyelitis can be caused by a variety of pathogens . Therefore, bacteriological studies are necessary to establish the etiologic diagnosis and determine the specific antimicrobial treatment required.

J Food Prot, 1996 Mar, 59(3), 327 - 30
Detection of staphylococcal enterotoxin H by an enzyme-linked immunosorbent assay; Su YC et al.; A double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) was developed for the detection of a newly identified staphylococcal enterotoxin H (SEH) . Peroxidase was conjugated to antibodies specific to the enterotoxin . 2,2'Azino-bis(3-ethylbenz-thiazoline-6-sulfonic acid)(ABTS) in hydrogen peroxide solution was used as the enzyme substrate . A standard curve of purified SEH was prepared with concentrations ranging from 1.3 to 50 ng/ml . SEH at levels equal to 2.5 ng/ml and higher were detected by this procedure . Culture supernatant from the growth of selected Staphylococcus aureus strains was analyzed by using the ELISA . SEH was produced by three of 20 strains that produced one identified enterotoxin . Ten of 21 strains, previously shown to produce substances that induced emesis in monkeys but not any known enterotoxins (A through E), were also positive for SEH production . The other 11 strains gave negative results in the ELISA, indicating that other unidentified serological types of enterotoxin exist.

J Formos Med Assoc, 1999 Jul, 98(7), 519 - 21
Varicella arthritis diagnosed by polymerase chain reaction; Chen MK et al.; We report a 2-year-old girl who developed acute arthritis of the left knee 4 days after the onset of a typical varicella infection . She was first thought to have pyogenic arthritis caused by Staphylococcus aureus . Accordingly, oxacillin was administered upon hospitalization . On the third day after hospitalization, bacterial cultures of the synovial fluid and blood showed no growth and oxacillin was discontinued . Although a viral culture of the synovial fluid for varicella-zoster virus (VZV) was negative, varicella DNA was identified by means of polymerase chain reaction (PCR) with VZV-specific primers . The patient recovered spontaneously . To differentiate this condition from septic arthritis is important . PCR is a sensitive technique that can demonstrate the presence of VZV DNA in synovial fluid, even if viral cultures are negative.

Pediatr Neurosurg, 1999 May, 30(5), 253 - 7
Does age or other factors influence the incidence of ventriculoperitoneal shunt infections?
Davis SE, Levy ML, McComb JG, Masri-Lavine L.
Some studies indicate that infants, especially those less than 1 month of age have a higher incidence of ventriculoperitoneal shunt infections . To look at age as well as other variables that might relate to the rate of shunt infection, we reviewed the records of all patients undergoing a ventriculoperitoneal shunt insertion or revision at our institution from January 1, 1985, to December 31, 1994 . There were a total of 2,325 ventriculoperitoneal shunting procedures performed on 1,193 patients with a male:female ratio of 678:515 . The overall infection rate was 3.2% (74 infections) . Analyzed by age, the infection rates were as follows: <1 month 9/223 (4.0%), 1-6 months 16/449 (3.6%), 6-12 months 13/297 (4.4%), 12-18 months 3/122 (2.5%), 18-24 months 7/116 (6.0%) and 24+ months 26/1, 118 (2.3%) . There was no statistically significant difference between age groups (p > 0.05) . Upon selectively examining premature neonates who developed hydrocephalus secondary to intraventricular hemorrhage from the figures given above, one finds that 2/44 (4.5%) of neonates became infected, which was also not significant . The infection rate was the same irrespective of whether the procedure was to insert or revise the shunt, or whether another operative procedure was done under the same anesthesia . The etiology of the hydrocephalus was not a factor, nor was the presence of an open neural tube defect . The presence of fluid accumulation along the shunt tract or at another neurological operative site was associated with a significant increase in incidence of infection 15/168 (8.9%) when compared to those with no fluid accumulation (p < 0.001) . The type of infecting organism was divided roughly in thirds, with relatively equal representation from Staphylococcus epidermidis/coagulase negative and Staphylococcus aureus . The remaining third was comprised of a wide variety of organisms.

J Antimicrob Chemother, 1999 Jul, 44(1), 57 - 64
Effects of salicylate and related compounds on fusidic acid MICs in Staphylococcus aureus; Price CT et al.; Salicylate, acetyl-salicylate, benzoate and ibuprofen increased fusidic acid MICs for fusidic acid-resistant and -susceptible strains of Staphylococcus aureus representing six genetic lineages . The effects of these substances on fusidic acid resistance levels occurred in a strain-dependent manner . The weak acid acetate, and acetaminophen did not alter fusidic acid resistance levels, while the addition of saligenin, the alcohol of salicylate, reduced gradient plate MICs for all strains studied . These findings indicate that a benzoic acid structure is required for the induction of increased intrinsic fusidic acid resistance levels . When 2 mM salicylate was added to media used in population analyses, the number of cells able to survive on high concentrations of fusidic acid increased . This increase in cell survival was observed in two unrelated fusidic acid-resistant strains, with chromosomal (WBG8287) or plasmid (WBG1576) mediated resistance determinants and two unrelated susceptible strains . The salicylate-induced increase in fusidic acid resistance was phenotypic at low fusidic acid concentrations (relative to resistance phenotype) for WBG8287 and a fusidic acid-susceptible strain . On media containing salicylate and high fusidic acid concentrations, the mutation frequency to higher fusidic acid resistance levels was greater for WBG8287, compared with unsupplemented fusidic acid-containing media . These experiments provide evidence for a novel salicylate inducible fusidic acid resistance mechanism in S . aureus.

Int J Legal Med, 1999, 112(5), 303 - 8
Iatrogenic staphylococcus aureus septicaemia following intravenous and intramuscular injections: clinical course and pathomorphological findings; Tsokos M et al.; The clinical course, autopsy and histological findings are presented from three (one 33-year-old female and two males aged 26 and 56) fatalities resulting from injection therapy which has produced Staphylococcus aureus septicaemia . The autopsies were performed within 2-4 days postmortem . No primary focus other than the insertion site of the peripheral venous catheters or the intramuscular injections, representing the initial entry site of Staphylococcus aureus, could be identified . Death was attributed directly to the staphylococcal infection as a result of iatrogenic injection therapy for the treatment of a non-severe underlying illness (premature labour pains, acute loss of hearing, lumbago) . The forensic diagnosis of Staphylococcus aureus septicaemia following iatrogenic injections has to be critically evaluated and can be established routinely in cases with delayed autopsy only when no other cause of death is revealed by autopsy, no apparent source of infection other than the insertion site can be detected and careful attention is paid to histological and bacteriological findings . All doubtful cases of nosocomial bloodstream infections with fatal outcome should undergo an immediate autopsy . In cases of very early forensic involvement microbiological investigations, including phagotyping, molecular biological characterization and identification of bacterial toxins from micro-organisms out of appropriate specimens obtained postmortem, could be efforts of potential evidential value regarding the aetiological proof . To optimize aetiopathogenetic conclusions concerning a causal relationship between iatrogenic injections and septic complications, the medicolegal investigation should also include an interdisciplinary co-operation with consultants from other relevant fields (e.g . microbiology and hygienics).

J Antimicrob Chemother, 1999 Jul, 44(1), 33 - 41
Lentivirus-derived antimicrobial peptides: increased potency by sequence engineering and dimerization; Tencza SB et al.; We have previously described a family of cationic amphipathic peptides derived from lentivirus envelope proteins that have properties similar to those of naturally occurring antimicrobial peptides . Here, we explored the effects of amino acid truncations and substitutions on the antimicrobial potency and selectivity of the prototype peptide, LLP1 . Removal of seven residues from the C-terminus of LLP1 had little effect on potency, but abrogated haemolytic activity . Replacement of the two glutamic acid residues of LLP1 with arginine resulted in a peptide with greater bactericidal activity . We discovered that the cysteine-containing peptides spontaneously formed disulphide-linked dimers, which were 16-fold more bactericidal to Staphylococcus aureus . Monomeric and dimeric LLP1 possessed similar alpha helical contents, indicating that disulphide formation did not alter the peptide's secondary structure . The dimerization strategy was applied to magainin 2, enhancing its bactericidal activity eight-fold . By optimizing all three properties of LLP1, a highly potent and selective peptide, named TL-1, was produced . This peptide is significantly more potent than LLP1 against gram-positive bacteria while maintaining high activity against gram-negative organisms and low activity against eukaryotic cells . In addition to new antimicrobial peptides, these studies contribute useful information on which further peptide engineering efforts can be based.

Diagn Microbiol Infect Dis, 1999 Aug, 34(4), 301 - 7
Sitafloxacin (DU-6859a) and trovafloxacin: postantibiotic effect and in vitro interactions with rifampin on methicillin-resistant Staphylococcus aureus; Giamarellou-Bourboulis EJ et al.; Sitafloxacin (DU-6859a) and trovafloxacin are novel quinolones potent on methicillin-resistant Staphylococcus aureus (MRSA) that are designed for once daily administration . In order to define the adequacy of the above regimen for the therapy of infections by multiple drug-resistant MRSA, their postantibiotic effect (PAE), their bactericidal activity, and their interactions with rifampin were determined on 14 MRSA isolates resistant to both ciprofloxacin and rifampin . PAE was defined after 1-h exposure to 1x, 4x, and 10x MIC and the killing effect after exposure to 1x and 4x MIC . Rifampin was applied for interactive studies at a concentration of 2 micrograms/mL, which is equal to its mean serum level . Median PAEs produced by 1x, 4x, and 10x MIC of sitafloxacin were 1.39, 3.75, and 6.61 h respectively, and by 1x, 4x, and 10x MIC of trovafloxacin 0.87, 2.07, and 2.23 h respectively . PAEs achieved by sitafloxacin were statistically shown to be longer than those achieved by trovafloxacin; PAEs achieved by a concentration of 10x MIC of each quinolone did not differ significantly from those achieved by a concentration of 4x MIC . Both the 4x and 10x MIC concentrations produced a more prolonged PAE than the 1x MIC concentration . A rapid bactericidal activity was expressed over the first 6 h of growth by each quinolone involving 80% of isolates enhanced in some isolates by their interaction with rifampin . The above findings revealed an extended PAE and a rapid killing effect of both sitafloxacin and trovafloxacin on MRSA resistant to ciprofloxacin and to rifampin, thus supporting their once daily administration in the therapy of infections by multiple drug-resistant MRSA . However little in vitro benefit is derived by their interaction with rifampin.

Microb Pathog, 1999 Aug, 27(2), 61 - 70
Co-production of staphylococcal enterotoxin A with toxic shock syndrome toxin-1 (TSST-1) enhances TSST-1 mediated mortality in a D-galactosamine sensitized mouse model of lethal shock; De Boer ML et al.; It has previously been reported that staphylococcal enterotoxin A (SEA) is frequently co-expressed with toxic shock syndrome toxin-1 (TSST-1) in menstrual Toxic Shock Syndrome (MTSS)-associated Staphylococcus aureus . It was hypothesized that co-production of SEA and TSST-1 might yield a more virulent strain than one that produced TSST-1 but not SEA . To test this hypothesis, a TSST-1+/SEA- derivative of S . aureus RN3984 (TSST-1+/SEA+) was constructed by plasmid integration, and the isogenic pair were introduced into a D-galactosamine sensitized mouse model of lethal shock . At 72 h, 27 out of 30 (90%) mice inoculated with the parental strain died, as compared to 21 out of 30 (70%) mice inoculated with the isogenic derivative (P=0.05, Fisher's exact test; 1-tailed; 95% confidence limits, 0.80-20.80) . Our results suggest that co-production of SEA with TSST-1 does enhance the ability of this strain of S . aureus to induce lethal shock in vivo . This enhanced virulence could be due to an additive or synergistic activity of the toxin combination on T cell proliferation and cytokine production in the animal model.

J Wound Care, 1999 Apr, 8(4), 177 - 9
The use of larval therapy in wound management in the UK; Courtenay M; This study identifies hospitals and institutions in the UK using larval therapy, and determines how this therapy is clinically managed in 23 of them . A qualitative approach was adopted, with the collection of documentary evidence and data from semi-structured interviews . Larval therapy is currently used in over 350 hospitals and institutions in the UK in the treatment of a variety of wound types . It was evident from the findings that it is generally used as a last resort . However, in two hospitals, this treatment method is part of the hospital's wound management policy . Nurses were able to identify wounds that have a better response to larval therapy and recognise symptoms that may occur during treatment . A number of wound types were found to be 'difficult' with regards to larvae application, and nurses had developed their own practices involving the application of dressings and the length of time larvae were left on wounds . Patients receiving this treatment reported few symptoms . It was claimed that larval therapy is particularly effective against methicillin-resistant Staphylococcus aureus (MRSA).

Eur J Immunol, 1999 Aug, 29(8), 2400 - 5
Outcome of Staphylococcus aureus-triggered sepsis and arthritis in IL-4-deficient mice depends on the genetic background of the host; Hultgren O et al.; Disruption of the IL-4 gene in two inbred mouse strains revealed a dual role of IL-4 in Staphylococcus aureus sepsis and arthritis depending on the host's genetic background . IL-4 was protective in 129SV mice, since 5 days after S . aureus inoculation IL-4(-/-) mice displayed 70% mortality as compared to survival of all 129SV wild-type counterparts . On the other hand, IL-4 was detrimental in C57BL/6 mice, since survival of IL-4(-/-) C57BL/6 mice was increased, as compared to wild-type controls, due to decreased staphylococcal growth . Altogether, our results show the dual role of IL-4 in S . aureus sepsis and arthritis, depending on the genetic background of the host.

No Shinkei Geka, 1999 Aug, 27(8), 729 - 33
{Prevention of MRSA spread in the neurological field: intranasal application of mupirocin calcium ointment}; Niwa J et al.; From September 1997 to March 1998, forty patients with cerebral disorders were investigated . They were divided into two groups: one treated and the other untreated . Mupirocin calcium ointment (MCO) was applied three times a day for three days into the nasal cavities of the patients in the treated group . In order to check the growth of MRSA (methicillin-resistant Staphylococcus aureus), bacterial isolation culture from the nasal cavity was carried out on admission, one week after admission and one month after admission . MRSA was nor detected in isolation culture of any of the cases on admission . One week later MRSA was detected in isolation culture of one case of the 20 MCO treated patients and in three of the 20 untreated patients . There was no significant difference between treated and untreated groups . In isolation culture after one month, MRSA was recognized in four cases of 16 in the MCO treated group (three patients were discharged and one expired) . On the other hand, it was recognized in eight cases of thirteen in the untreated group (seven cases were discharged) . MRSA infection of the nasal cavity decreased significantly due to MCO treatment (p < 0.05) . It is suggested that the nasal carriage of MRSA was prevented by intranasal application of MCO on admission.

Immunology, 1999 Aug, 97(4), 601 - 10
Different effect of granulocyte colony-stimulating factor or bacterial infection on bone-marrow cells of cyclophosphamide-treated or irradiated mice; Buisman AM et al.; In the present study, the effect of treatment with granulocyte colony-stimulating factor (G-CSF) on cellular composition of the bone marrow and the number of circulating leucocytes of granulocytopenic mice, whether or not infected with Staphylococcus aureus, was assessed . With two monoclonal antibodies, six morphologically distinct cell populations in the bone marrow could be characterised and quantitated by two-dimensional flow cytometry . Granulocytopenia was induced by cyclophosphamide or sublethal irradiation . Cyclophosphamide predominantly affected the later stages of dividing cells in the bone marrow resulting in a decrease in number of granulocytic cells, monocytic cells, lymphoid cells and myeloid blasts . G-CSF administration to cyclophosphamide-treated mice increased the number of early blasts, myeloid blasts and granulocytic cells in the bone marrow, which indicates that this growth factor stimulates the proliferation of these cells in the bone marrow . During infection in cyclophosphamide-treated mice the number of myeloid blasts increased . However, when an infection was induced in cyclophosphamide and G-CSF-treated mice, the proliferation of bone-marrow cells was not changed compared to that in noninfected similarly treated mice . Sublethal irradiation affected all bone-marrow cell populations, including the early blasts . G-CSF-treatment of irradiated mice increased only the number of myeloid blasts slightly, whereas an infection in irradiated mice, whether or not treated with G-CSF, did not affect the number of bone-marrow cells . Together, these studies demonstrated that irradiation affects the early blasts and myeloid blasts in the bone marrow more severely than treatment with cyclophosphamide . Irradiation probably depletes the bone marrow from G-CSF-responsive cells, while cyclophosphamide spared G-CSF responsive cells, thus enabling the enhanced G-CSF-mediated recovery after cyclophosphamide treatment . Only in these mice, bone marrow recovery is followed by a strong mobilisation of mature granulocytes and their band forms from the bone marrow into the circulation during a bacterial infection.

Eur J Clin Invest, 1999 Aug, 29(8), 697 - 9
A novel visual immunoassay for coeliac disease screening; Garrote JA et al.; BACKGROUND: To date, the most commonly accepted techniques for the screening of coeliac disease are indirect immunofluorescence and enzyme-linked immunosorbent assay (ELISA), which reveal antiendomysium and antigliadin antibodies respectively . We report the use of a simple visual system for coeliac disease screening based on the use of Staphylococcus aureus protein A, which binds to both IgG and IgA, thus avoiding the need for two parallel immunoassays . MATERIALS AND METHODS: Opaque polystyrene microwell strips coated with a wheat gliadin extract were incubated with sera followed by incubation with protein A-colloidal gold conjugate . The resulting colour was compared with that of positive and negative control sera . The procedure took less than an hour . RESULTS: One hundred and forty-five biopsy-proven sera, 94 from active coeliac patients and 51 from non-coeliac patients with diverse gastrointestinal pathologies or diabetes mellitus, were assayed . Ninety of the 94 sera from the active coeliac patients were positive, whereas only 3 of the 51 non-coeliac control subjects were positive . The technique has a sensitivity of 95.7% and a specificity of 94.1% . CONCLUSIONS: The sensitivity and specificity of the visual system are greater than those of most ELISA systems and are similar to those observed with IgA antiendomysium antibodies when tested in the same population . Moreover, it is inexpensive, quick, simple to perform and easy to interpret, i.e . it requires no qualified personnel . It is for these features, together with the outstanding sensitivity and specificity, that we propose this immunoassay as a new test for reliable coeliac disease screening.

Clin Exp Allergy, 1999 Aug, 29(8), 1110 - 7
Possible influences of Staphylococcus aureus on atopic dermatitis-- the colonizing features and the effects of staphylococcal enterotoxins; Morishita Y et al.; BACKGROUND: Heavy colonization of atopic dermatitis (AD) with Staphylococcus aureus is well documented . This phenomenon suggests that S . aureus in AD lesions influences the disease processes of AD . OBJECTIVE: We describe the importance of the presence of S . aureus and staphylococcal enterotoxins A and B (SEA, SEB) in AD lesions . METHODS: We investigated the colonizing features of S . aureus in AD lesions using electron microscopy, the distribution of SEB in the eczematous skin of AD using immunofluorescence, the effects of SEA and SEB on normal human epidermal keratinocytes in organ culture, and the presence of specific IgE antibodies to SEA and/or SEB in serum of AD patients by enzyme immunoassay . RESULTS: S . aureus in AD lesions colonized on and in the horny layers of the eczematous skin . SEB produced by S . aureus was distributed mainly on the dermal-infiltrated cells, especially on eosinophils . SEA and SEB stimulated expression of ICAM-1 and HLA-DR in normal human keratinocytes . More than half of the AD patients in the present study had specific IgE antibodies to SEA and/or SEB in their serum . CONCLUSION: S . aureus and SEs have important roles in the exacerbation and prolongation of AD.

Infect Immun, 1999 Sep, 67(9), 4737 - 43
Staphylococcus aureus isolates from patients with Kawasaki disease express high levels of protein A; Wann ER et al.; Kawasaki disease (KD) is an acute vasculitis of young children that can be complicated by coronary artery abnormalities . Recent findings suggest that a superantigen(s) may play an important role in stimulating the immune activation associated with the disease, although the origin of this superantigen(s) is unclear . Staphylococcus aureus, isolated from the rectum or pharynx of patients with KD, secretes toxic shock syndrome toxin 1 (TSST-1) . The KD isolates express low levels of other exoproteins compared to isolates from patients with toxic shock syndrome (TSS) . Thus, it was previously suggested that the KD isolates may be defective in the global regulatory locus agr (for accessory gene regulator), which positively regulates these factors (D . Y . M . Leung et al., Lancet 342:1385-1388, 1993) . Here we describe another characteristic of KD isolates . When considered collectively, the KD isolates were found to express higher levels of staphylococcal protein A than the TSS isolates, another characteristic of an agr-defective phenotype . This correlated with a higher level of spa mRNA in these isolates . In contrast, the KD and TSS isolates expressed comparable levels of TSST-1, consistent with previous findings (D . Y . M . Leung et al., Lancet 342:1385-1388, 1993) . Analysis of RNAIII transcript levels and nucleotide sequence analysis of the RNAIII-coding region suggested that the KD isolates are not defective in RNAIII, the effector molecule of the agr regulatory system . However, induction of RNAIII transcription in the KD isolates did not result in a dramatic decrease in the amount of spa mRNA, as has been reported for other strains (F . Vandenesch, J . Kornblum, and R . P . Novick, J . Bacteriol . 173:6313-6320, 1991).

Pharmacotherapy, 1999 Aug, 19(8 Pt 2), 129S - 132S; discussion 133S-137S
Decreased antimicrobial resistance after changes in antibiotic use; Smith DW; Vancomycin-resistant enterococci (VRE) and methicillin-oxacillin-resistant Staphylococcus aureus (MRSA) originally predominated in large medical centers; however, these isolates are now common in community hospitals and community clinics . No simple answer is available regarding control of antimicrobial-resistant bacteria, especially VRE and MRSA, as their numbers increase and pose a more serious threat to patient care . The source of colonization is often difficult to identify because of transport of patients among different locations on the continuum of care (e.g., hospital to extended care facility to home and back) . At one hospital, control strategies greatly reduced the occurrence of gram-negative bacteria such as VRE . Since 1994, VRE declined from 16% to 5% . Similarly, the number of MRSA isolates declined from 35% to 23% . These declines are attributed to a cohesive working relationship among pharmacists, microbiologists, and infectious disease physicians and personnel, and to a decision to decrease administration of cephalosporins in favor of piperacillin-tazobactam.

Afr J Med Med Sci, 1997 Sep-Dec, 26(3-4), 139 - 40
Pattern of bacterial pathogens in surgical wound infections; Oni AA et al.; Wound swabs from surgical patients were studied from 1989 to 1991 to review the pattern of nosocomial infection in the University College Hospital, Ibadan, Nigeria . The prevalence rate of nosocomial infection was 4.9% . The ratio of gram-negative to gram-positive organisms in wound infection was 3:1 with klebsiella species and Pseudomonas species emerging as the most important gram-negative organisms . Staphylococcus aureus was the single most prevalent organisms in surgical would infections . Recommendations on control measures are given.

Afr J Med Med Sci, 1997 Sep-Dec, 26(3-4), 119 - 21
Plasmid profiles of multiple drug resistant local strains of Staphylococcus aureus; Adeleke OE et al.; In an attempt to determine the molecular basis for the degree of resistance among strains of S . aureus to Beta-lactam antibiotics, 50 clinical isolates of coagulase-positive strains of S . aureus were obtained . The strains and a control strain, Oxford NCTC 6571, were screened for the presence of Beta-lactamase, R-plasmid, and sensitivity to six Beta-lactam antibiotics . The molecular weight of the isolated R-plasmid DNA was determined by agarose gel electrophoresis . Forty-five of the 50 strains of S . aureus exhibited single or multiple drug-resistance . Plasmid DNA isolated from 13 of the resistant strains of S . aureus had the same molecular weight of 21 kb or 13.63 MDa, while one of the 13 strains and 3 others had R-plasmids with a higher molecular weight.

J Biol Chem, 1999 Aug 27, 274(35), 24906 - 13
Trench-shaped binding sites promote multiple classes of interactions between collagen and the adherence receptors, alpha(1)beta(1) integrin and Staphylococcus aureus cna MSCRAMM; Rich RL et al.; Most mammalian cells and some pathogenic bacteria are capable of adhering to collagenous substrates in processes mediated by specific cell surface adherence molecules . Crystal structures of collagen-binding regions of the human integrin alpha(2)beta(1) and a Staphylococcus aureus adhesin reveal a "trench" on the surface of both of these proteins . This trench can accommodate a collagen triple-helical structure and presumably represents the ligand-binding site (Emsley, J., King, S . L., Bergelson, J . M., and Liddington, R . C . (1997) J . Biol . Chem . 272, 28512-28517; Symersky, J., Patti, J . M., Carson, M., House-Pompeo, K., Teale, M., Moore, D., Jin, L., Schneider, A., DeLucas, L . J., Hook, M., and Narayana, S . V . L . (1997) Nat . Struct . Biol . 4, 833-838) . We report here the crystal structure of the alpha subunit I domain from the alpha(1)beta(1) integrin . This collagen-binding protein also contains a trench on one face in which the collagen triple helix may be docked . Furthermore, we compare the collagen-binding mechanisms of the human alpha(1) integrin I domain and the A domain from the S . aureus collagen adhesin, Cna . Although the S . aureus and human proteins have unrelated amino acid sequences, secondary structure composition, and cation requirements for effective ligand binding, both proteins bind at multiple sites within one collagen molecule, with the sites in collagen varying in their affinity for the adherence molecule . We propose that (i) these evolutionarily dissimilar adherence proteins recognize collagen via similar mechanisms, (ii) the multisite, multiclass protein/ligand interactions observed in these two systems result from a binding-site trench, and (iii) this unusual binding mechanism may be thematic for proteins binding extended, rigid ligands that contain repeating structural motifs.

J Interferon Cytokine Res, 1999 Jul, 19(7), 705 - 10
Effectiveness of IFN-gamma for liver abscesses in chronic granulomatous disease; Conte D et al.; In chronic granulomatous disease, interferon-gamma (IFN-gamma) significantly reduces the incidence and severity of recurrent infections, but its effectiveness administered ex novo during acute infection has been reported in only one case . In this report, we describe two adult brothers with chronic granulomatous disease treated successfully with IFN-gamma for acute liver abscesses . Two brothers with severe recurrent infections of unknown origin were hospitalized for septic fever, malnutrition, and ultrasonographic evidence of liver abscess . Autosomal recessive chronic granulomatous disease was diagnosed based on lack of superoxide anion production by phagocytes and absence of p47-phox protein . An antibiotic regimen specifically directed against Staphylococcus aureus was ineffective, whereas treatment with 50 microg/m2 IFN-gamma s.c . thrice weekly induced complete healing with scarring within 3 months . No septic recurrence was observed during a 4-year follow-up period . In chronic granulomatous disease, IFN-gamma is effective not only in preventing but also in healing life-threatening acute infections.

Int J STD AIDS, 1999 Jul, 10(7), 460 - 3
Reactivity of a dual amplified chlamydia immunoassay with different serovars of Chlamydia trachomatis; Okadome A et al.; A study was undertaken with different serovars (D, E, F, L2, MoPn) of Chlamydia trachomatis to determine the analytical sensitivity of a new dual amplified immunoassay (IDEIA PCE Chlamydia) for detecting chlamydial lipopolysaccharide . IDEIA PCE Chlamydia incorporates a polymer conjugate consisting of multiple copies of antibody and enzyme molecules to provide signal amplification . The test was also assessed with different protein A producing strains of Staphylococcus aureus in order to assess whether the use of a multiple antibody conjugate increased nonspecific binding . The detection limits varied for each serovar with a detection limit of 38 IFU/ml obtained with serovar F and 237 IFU/ml obtained with serovar D . The incorporation of the polymer conjugate resulted in a 2-5 fold increase in analytical sensitivity compared to an earlier version of the test using a conventional conjugate . No increase in cross reactivity with protein A producing strains of S . aureus was obtained . The new dual amplified test format offers potential as a sensitive low-cost screening assay for C . trachomatis infections.

Microbios, 1999, 97(387), 75 - 83
Changes in the phage typing patterns of Staphylococcus aureus strains at Concepción, Chile, in the last 30 years; Madrid VV et al.; Staphylococcus aureus is a ubiquitous pathogen still implicated as a common cause of community- and hospital-acquired infections . This micro-organism has demonstrated an immense adapting capacity to rapid environmental changes . In recent years, multiresistant strains have caused increasing nosocomial infections in several parts of the world . In the period 1993-94, 455 clinical isolates were typed on the basis of traditional phage typing procedure and these data were compared with others from similar studies carried out at the Department of Microbiology, University of Concepcion in 1960, 1972, and 1982 . Throughout the years, phage groups have been shifting from group I to group III and examination of phage types show that types 80 and 80/81 which were the most virulent and resistant by the 1960s, had disappeared . Nowadays, types 75 and 54/75 are most frequently found, and these have been associated with methicillin-resistant S . aureus.

Pediatr Int, 1999 Aug, 41(4), 341 - 5
Analysis of tumor necrosis factor-alpha production and polymorphisms of the tumor necrosis factor-alpha gene in individuals with a history of Kawasaki disease; Kamizono S et al.; BACKGROUND: Tumor necrosis factor (TNF)-alpha plays a central role in the pathogenesis of vasculitis in Kawasaki disease (KD) . To address the genetic background of KD, we investigated the level of TNF-alpha production and genetic polymorphisms in the 5' flanking region of the TNF-alpha gene in healthy children with a history of KD . METHODS: For TNF-alpha production, peripheral blood mononuclear cells (PBMC) of children with a history of KD (n = 61) and of non-KD children (n = 35) were stimulated with phorbol 12-myristate 13-acetate, toxic shock syndrome toxin-1 (TSST-1) and the culture supernatant of Staphylococcus aureus derived from a KD patient (S-6), which had several superantigenic activities . The genetic background of KD was addressed by studying polymorphisms in the 5' flanking region of the TNF-alpha gene at positions -1031 (thymine (T) to cytosine (C) change, termed -1031C), -863 (C to adenine (A), -863A), -857 (C to T, -857T), -308 (guanine (G) to A, -308A) and -238 (G to A, -238A) in KD, using dot-blot hybridization with sequence-specific oligonucleotide probes . RESULTS: The PBMC of KD patients with coronary artery lesions produced slightly higher levels of TNF-alpha in response to the bacterial products (such as TSST-1 and S-6) . None of the polymorphisms in the 5' flanking region of the TNF-alpha gene were related to KD . CONCLUSIONS: These results suggest that a genetic disposition towards overproduction of TNF-alpha in response to bacterial products may be involved in the pathogenesis of KD.

Kyobu Geka, 1999 Aug, 52(9), 735 - 8
{Efficacy of mupirocin in eradicating methicillin-resistant Staphylococcus aureus from nasal discharge in carrying cardiovascular surgical patients}; Soga Y et al.; Methicillin-resistant Staphylococcus aureus from nasal discharge was identified in 37 (2.5%) cardiovascular patients operated between 1995 and 1997; 25 male and 12 female, ranging from 1 to 83 years (mean 63); 2 were excluded because of Arbekacin or Isodine-gel treatment . The first 17 were treated with Vancomycin inhalation (V group) and eradication was considered to have been achieved when 3 consecutive negative cultures were obtained; the subsequent 18 were treated with Mupirocin (M group) and eradication was determined by 1 negative culture . In post-eradication electively operated 13 V and 15 M, postoperative MRSA infection was observed in one M (wound infection); the interval from the first nasal culture to the operation was 68 +/- 58 in V and 32 +/- 12 days in M, respectively (p < 0.05) . In the remaining 7 who had to undergo emergency surgery while waiting for eradication because of progression of symptoms (2 V) or prior to instituting treatment (2 V, and 3 M), postoperative MRSA infection was observed in 2 M (both pneumonia) . No deaths from infection were observed . Though the time required for conversion of the nasal culture was longer in V (13 +/- 20) than in M (7 +/- 1 days) differences were not significant . Mupirocin is easier to use, eradication can be achieved generally within a week.

J Immunol, 1999 Sep 1, 163(5), 2821 - 8
Altered immune responses and susceptibility to Leishmania major and Staphylococcus aureus infection in IL-18-deficient mice; Wei XQ et al.; IL-18, formerly designated IFN-inducing factor, is a novel cytokine produced by activated macrophages . It synergizes with IL-12 in the induction of the development of Th1 cells and NK cells . To define the biological role of IL-18 in vivo, we have constructed a strain of mice lacking IL-18 . Homozygous IL-18 knockout (-/-) mice are viable, fertile, and without evident histopathologic abnormalities . However, in contrast to the heterozygous (+/-) or wild-type (+/+) mice, which are highly resistant to the infection of the protozoan parasite Leishmania major, the IL-18-/- mice are uniformly susceptible . The infected IL-18-/- mice produced significantly lower levels of IFN-gamma and larger amounts of IL-4 compared with similarly infected +/- and +/+ mice . In contrast, when infected with the extracellular Gram-positive bacteria Staphylococcus aureus, the IL-18-/- mice developed markedly less septicemia than similarly infected wild-type (+/+) mice . However, the mutant mice developed significantly more severe septic arthritis than the control wild-type mice . This was accompanied by a reduction in the levels of Ag-induced splenic T cell proliferation, decreased IFN-gamma and TNF-alpha synthesis, but increased IL-4 production by the mutant mice compared with the wild-type mice . These results therefore provide direct evidence that IL-18 is not only essential for the host defense against intracellular infection, but it also plays a critical role in regulating the synthesis of inflammatory cytokines, and therefore could be an important target for therapeutic intervention.

J Surg Res, 1999 Sep, 86(1), 97 - 102
Use of cefazolin microspheres to treat localized methicillin-resistant Staphylococcus aureus infections in rats; Fallon MT et al.; BACKGROUND: In a previous study, the topical administration of biodegradable, controlled-release poly-(dl-lactide-co-glycolide) cefazolin microspheres could effectively prevent surgical wound infections with a sensitive strain of Staphylococcus aureus in an experimental animal model . The objective of the current study was to evaluate and compare the efficacy of topical antibiotic therapy with cefazolin microspheres to systemic cefazolin therapy for the treatment of experimental rat surgical wounds contaminated with a methicillin-resistant strain of S . aureus (MRSA) . METHODS: A local infection model in rats was used . MRSA was used to infect pockets surgically produced in the paraspinous muscles . Groups of rats received either topical cefazolin microspheres, topical cefazolin powder, parenteral cefazolin, or no treatment . Feces were cultured to evaluate the effect of antibiotic therapy on gut flora . RESULTS: The rate of clinical wound infection following topical application of cefazolin microspheres (13%) was significantly lower than the 53% infection rate observed in rats who had received a 2-week course of systemic cefazolin therapy (P = 0.046) . Moreover, single-dose topical antibiotic therapy with cefazolin microspheres completely eradicated MRSA from the wounds of 7 of 15 (47%) animals . There was no statistically significant difference, however, in the rate of clinical wound infection between rats whose wounds were treated topically with free cefazolin powder and those treated with systemic cefazolin (P = 0.12) . Importantly, selection of antibiotic-resistant bacteria was associated with systemic but not local cefazolin therapy . CONCLUSION: The results of this study suggest that topical antibiotic therapy with controlled-release cefazolin microspheres may be effective for the prevention of wound infection with both methicillin-sensitive and methicillin-resistant strains of S . aureus in selected surgical procedures that are at high risk of developing postoperative wound infection.

Clin Infect Dis, 1999 May, 28(5), 1119 - 25
Determinants of vancomycin use in adult intensive care units in 41 United States hospitals; Fridkin SK et al.; We analyzed data from a prospective observational cohort study that included 108 adult intensive care units (ICUs) in 41 United States hospitals . Use of vancomycin (defined daily doses per 1,000 patient-days), nosocomial infection rates, and proportion of all Staphylococcus aureus isolates resistant to methicillin (MRSA rate) were recorded from January 1996 through November 1997 . The median rate of vancomycin use was lowest in coronary care ICUs and highest in general surgical ICUs . Prior approval before use of vancomycin was required in only 26 (24%) of the 108 ICUs . In a multivariate linear regression model, rates of MRSA, central line-associated bloodstream infection, and the type of ICU were independent predictors of vancomycin use . None of the vancomycin control practices was associated with lower rates of vancomycin use; however, it is important to recognize that this database was not designed to measure rates of inappropriate use . Vancomycin use is heavily determined by rates of endemic MRSA and central line-associated bloodstream infection . Efforts to reduce these rates through infection control activities should be included in hospitals' efforts to reduce vancomycin use.

J Allergy Clin Immunol, 1999 Aug, 104(2 Pt 1), 441 - 6
Evaluation of the staphylococcal exotoxins and their specific IgE in childhood atopic dermatitis; Nomura I et al.; BACKGROUND: Superantigenic exotoxins produced by Staphylococcus aureus and their specific IgE antibodies are thought to be important precipitating factors of atopic dermatitis (AD), but there are few reports evaluating these 2 factors at the same time . OBJECTIVE: We examined whether the presence of the exotoxins sampled from the skin of patients with AD and the levels of anti-exotoxin IgE antibodies in their sera correlated with their severity of AD . METHODS: Patients with mild-to-severe AD, 1 to 22 years of age, were evaluated by using Leicester's scoring system . Specific IgE antibodies against these exotoxins were determined by using ELISA . S aureus was isolated from 3 different areas of the skin . We examined whether the exotoxin (staphylococcal enterotoxin {SE}A, SEB, SEC, SED, and toxic shock syndrome toxin-1) could be detected . RESULTS: The levels of SEB-specific IgE were correlated with the severity of AD . Five of 6 patients having very high SEB-specific IgE antibody titers were under 6 years of age, and SEB was most frequently isolated (41%) . There was no difference in severity between patients with or without exotoxin-producing S aureus . The severity of 9 patients who had both exotoxin-producing S aureus on the skin and specific IgE antibody against the same exotoxin in sera was significantly higher than that of the other patients . CONCLUSIONS: Anti-SEB IgE titers correlate well with the severity of AD . The presence of exotoxin-producing S aureus may precipitate AD through its specific IgE antibody.

Clin Infect Dis, 1999 May, 28(5), 1036 - 42
Interferon gamma (IFN-gamma) deficiency in generalized Epstein-Barr virus infection with interstitial lymphoid and granulomatous pneumonia, focal cerebral lesions, and genital ulcers: remission following IFN-gamma substitution therapy; Andersson J et al.; A 26-year-old previously healthy woman developed granulomatous pneumonitis, encephalitis, and genital ulceration during primary Epstein-Barr virus (EBV) infection . EBV DNA was demonstrated by polymerase chain reaction analysis of serum, lung tissue, and genital ulcer specimens . Serology verified primary EBV infection . The patient lacked lymphocytes cytotoxic to autologous EBV-transformed B lymphocytes . No spontaneous or in vitro EBV-induced interferon gamma (IFN-gamma) production was evident in peripheral blood . The cells had normal IFN-gamma production when stimulated with Staphylococcus aureus exotoxin A . In the bone marrow and peripheral blood, the number of large granular CD56+ lymphocytes (natural killer cells) increased 39%-55%, but no CD4 or CD8 cell lymphocytosis was initially found . A partial clinical response was achieved with treatment with acyclovir, corticosteroids, and intravenous gamma-globulin . Because of persistent granulomatous central nervous system and lung involvement, subcutaneous IFN-gamma therapy was started but was discontinued after 3 months because of development of fever, pancytopenia, and hepatitis . This therapy initiated a complete clinical recovery, which occurred parallel to development of EBV-specific cytotoxic CD8+ T lymphocytes and normalization of natural killer cell lymphocytosis . These findings provide evidence for an EBV-induced lymphoproliferative disorder due to a T lymphocyte dysfunction associated with a selective lack of IFN-gamma synthesis.

Zhonghua Zheng Xing Shao Shang Wai Ke Za Zhi, 1997 Sep, 13(5), 377 - 9
{Analysis of antibiotic resistance and production of enterotoxin of MRSA}; Chen X et al.; 100 separate Staphylococcus aureus (S . a) isolates at Beijing Jishuitan Hospital during Oct . 1994-Apr . 1995 were submitted to determine the proportion of methicillin-resistant S . a (MRSA) and susceptibility test to 12 antibiotics . MIC determinations of the antibiotics were performed . Also, production rate of enterotoxin was measured with RPLA method . The results showed that MRSA constituted 60% of all cultures . (Burns Dept . 67.4%, Internal Medicine 62.5%, Orthopedics Dept . 44%) . The antibiotics with resistant rate of MRSA below 50% included vancomyin (3.3%), norvancomyin (5%) and amikacin (21.5%) . The production rate of enterotoxin was 100% in MRSA and 20% in MSSA (methicillin-sensitive S . a) . In this group, 35% of MRSA and 5% of MSSA produced more than 2 types of enterotoxin.

J Clin Pathol, 1999 Mar, 52(3), 225 - 7
Evaluation of the BBL Crystal MRSA ID System for detection of oxacillin resistance in Staphylococcus aureus; Kampf G et al.; AIMS: To evaluate the BBL Crystal MRSA ID System for detection of oxacillin resistance in Staphylococcus aureus . METHODS: 52 methicillin resistant S aureus (MRSA) from five different countries and 85 methicillin susceptible S aureus (MSSA) were included . The species was confirmed by tube coagulation and detection of the clumping factor using the Staphaurex Plus . Clonal non-identity of the MRSA isolates was shown by pulsed field gel electrophoresis . MIC values (oxacillin) were determined using the Etest . Polymerase chain reaction was carried out to detect the mecA gene . The BBL Crystal MRSA ID System was carried out according to the manufacturer's instructions . RESULTS: The BBL Crystal MRSA ID System showed fluorescence in 45 of 52 MRSA (sensitivity 86.5%; negative predicitive value 92.2%), and the specificity was 97.6% (positive predicitive value 95.7%) . Two of seven MRSA that failed to show fluorescence had MIC values (oxacillin) of 4 mg/litre . CONCLUSIONS: The BBL Crystal MRSA ID System is a valuable test for detecting oxacillin resistance in S aureus . Its major advantage is the short time (4-5 hours) required to perform the test when organisms are grown on tryptic soy agar or sheep blood agar . Difficulties may arise in borderline resistant isolates.

J Clin Microbiol, 1999 Sep, 37(9), 2952 - 61
Comparison of susceptibility testing methods with mecA gene analysis for determining oxacillin (methicillin) resistance in clinical isolates of Staphylococcus aureus and coagulase-negative Staphylococcus spp; Kohner P et al.; Ninety-nine clinical staphylococcal isolates (58 coagulase-negative Staphylococcus spp . {CoNS} and 41 Staphylococcus aureus isolates) were evaluated for susceptibility to oxacillin . The following susceptibility testing methods, media, and incubation conditions were studied: agar dilution by using Mueller-Hinton (MH) medium (Difco) supplemented with either 0, 2, or 4% NaCl and incubation at 30 or 35 degrees C in ambient air for 24 or 48 h; disk diffusion by using commercially prepared MH medium (Difco) and MH II agar (BBL) and incubation at 35 degrees C in ambient air for 24 or 48 h; and agar screen (spot or swab inoculation) by using commercially prepared agar (Remel) or MH agar (Difco) prepared in-house, each containing 4% NaCl and 6 microg of oxacillin/ml (0.6-microg/ml oxacillin was also studied with MH agar prepared in-house for the agar swab method and CoNS isolates) and incubation at 35 degrees C in ambient air for 24 or 48 h for swab inoculation and at 30 or 35 degrees C in ambient air for 24 or 48 h for spot inoculation . The results for these methods were compared to the results for mecA gene detection by a PCR method . Given the ability to support growth and the results for susceptibility testing (the breakpoint for susceptible isolates was </=2 microg/ml), the best methods for CoNS isolates were (i) agar dilution by using MH medium supplemented with 4% NaCl and incubation at 35 degrees C for 48 h (no growth failures were noted, and sensitivity was 97.6%) and (ii) agar screen (swab inoculation) by using MH medium prepared in-house supplemented with 4% NaCl and containing 0.6 microg oxacillin/ml and incubation at 35 degrees C for 48 h (one isolate that did not carry the mecA gene did not grow, and the sensitivity was 100%) . All but one (agar dilution without added NaCl and incubation at 30 degrees C for 48 h) of the methods tested revealed all oxacillin-resistant S . aureus isolates, and no growth failures occurred with any method . If the breakpoint for susceptibility was lowered to </=1 microg/ml for agar dilution methods, more CoNS isolates with oxacillin resistance related to the mecA gene were detected when 0 or 2% NaCl agar supplementation was used . Only one CoNS isolate with mecA gene-associated resistance was not detected by using agar dilution and MH medium supplemented with 4% NaCl with incubation for 48 h . When the breakpoint for susceptibility was decreased 10-fold (from 6.0 to 0.6 microg of oxacillin per ml) for the agar swab screen method, fully 100% of the CoNS isolates that carried the mecA gene were identified.

J Clin Microbiol, 1999 Sep, 37(9), 3068 - 71
Interactions between methicillin and vancomycin in methicillin-resistant Staphylococcus aureus strains displaying different phenotypes of vancomycin susceptibility; Howe RA et al.; Vancomycin-sensitive, -intermediate, and -heterointermediate methicillin-resistant Staphylococcus aureus isolates were tested by using E-tests to explore the interaction of methicillin and vancomycin . For the vancomycin-intermediate and -heterointermediate strains both drugs showed antagonism at concentrations below their MICs but synergy at methicillin concentrations near the MIC . This property could be used to screen for heterointermediate S . aureus strains.

J Clin Microbiol, 1999 Sep, 37(9), 2858 - 62
Community strain of methicillin-resistant Staphylococcus aureus involved in a hospital outbreak; O'Brien FG et al.; Western Australia (WA) has been able to prevent methicillin-resistant Staphylococcus aureus (MRSA) strains from outside of the state from becoming established in its hospitals . Recently, a single-strain outbreak of MRSA occurred in a WA metropolitan teaching hospital following admission of an infected patient from a remote community . The strain responsible for the outbreak was unrelated to any imported strains and spread rapidly in the hospital . Screening of two remote communities in the region from which the index case came revealed that 42% of the people in one community and 24% in the other carried MRSA . Isolates were typed by resistance pattern, plasmid analysis, contour-clamped homogeneous electric field electrophoresis, bacteriophage pattern, and coagulase gene restriction fragment length polymorphism . It was found that of the people carrying MRSA, 39% in the former community and 17% in the latter community were carrying an MRSA strain which was indistinguishable from the strain that caused the hospital outbreak.

J Clin Microbiol, 1999 Sep, 37(9), 2798 - 803
Methicillin-resistant Staphylococcus aureus clonal types in the Czech Republic; Melter O et al.; Molecular surveillance studies have documented the extensive spread of methicillin-resistant Staphylococcus aureus (MRSA) clones . Studies carried out by Centro de Epidemiologia Molecular-Network for Tracking Gram-Positive Pathogenic Bacteria (CEM/NET) led to the identification of two international multidrug-resistant strains, which were designated as the Iberian and Brazilian MRSA clones and which were defined by multiple genomic typing methods; these included ClaI restriction digests hybridized with mecA- and Tn554-specific DNA probes and pulsed-field gel electrophoresis (PFGE) . The genotypic characteristics of these clones are distinct: the Iberian clone is defined as mecA type I, Tn554 type E (or its variants), and PFGE pattern A (I:E:A), whereas the Brazilian clone is defined as mecA type XI (or its variants), Tn554 type B, and PFGE pattern B (XI:B:B) . In this study, we characterized 59 single-patient isolates of MRSA collected during 1996 and 1997 at seven hospitals located in Prague and five other cities in the Czech Republic by using the methodologies mentioned above and by using ribotyping of EcoRI and HindIII digests hybridized with a 16S-23S DNA probe . The Brazilian MRSA clone (XI:B:B) was the major clone (80%) spread in two hospitals located in Prague and one located in Brno; the Iberian MRSA clone (I:E:A or its variant I:DD:A), although less representative (12%), was detected in two hospitals, one in Prague and the other in Plzen . Almost all the strains belonging to clone XI:B:B (45 of 47) corresponded to a unique ribotype, E1H1, whereas most strains of the I:E:A and I:DD:A clonal types (6 of 7) corresponded to ribotype E2H2.

J Clin Microbiol, 1999 Sep, 37(9), 2789 - 92
Rapid slide latex agglutination test for detection of methicillin resistance in Staphylococcus aureus; van Griethuysen A et al.; The MRSA screen test (Denka Seiken Co., Ltd.), a commercially available, rapid (20-min) slide latex agglutination test for the determination of methicillin resistance by detection of PBP 2a in Staphylococcus aureus, was compared with the oxacillin agar screen test and PCR detection of the mecA gene . A total of 563 S . aureus isolates were tested . Two hundred ninety-six of the isolates were methicillin-susceptible isolates from cultures of blood from consecutive patients . Also, 267 methicillin-resistant isolates that comprised 248 different phage types were tested . Methicillin resistance was defined as the presence of the mecA gene . Of the 267 mecA gene-positive isolates, 263 were positive by the MRSA screen test (sensitivity, 98.5%), and all the mecA-gene negative strains were negative by the MRSA screen test (specificity, 100%) . The oxacillin agar screen test detected methicillin resistance in 250 of the mecA gene-positive isolates (sensitivity, 93.6%) . The sensitivity of the MRSA screen test was statistically significantly higher than the sensitivity of the oxacillin agar screen test (P < 0 . 05) . The MRSA screen test is a highly sensitive and specific test for the detection of methicillin resistance . Also, it offers results within half an hour and is easy to perform, which makes this test a valuable tool in the ongoing battle against methicillin-resistant S . aureus.

Scand J Immunol, 1999 Sep, 50(3), 250 - 5
Interaction with complement receptor 1 (CD35) leads to amelioration of sepsis-triggered mortality but aggravation of arthritis during Staphylococcus aureus infection; Sakiniene E et al.; The aim of this study was to assess the importance of complement receptor 1 (CR1, CD35) in Staphylococcus aureus arthritis and sepsis . The murine model of haematogenously acquired septic arthritis was used, injecting toxic shock syndrome toxin 1 (TSST-1)-producing S . aureus LS-1 intravenously . CR1 was blocked using immunoglobulin G (IgG) rat antimouse CR1 monoclonal antibody (MoAb) (8C12) . Evaluation of arthritis was performed clinically and histopathologically . In addition, the effect of blocking CR1 was assessed on the phagocytic activity of leucocytes and on T-cell dependent and independent inflammation . Seven days after inoculation with bacteria, 96% of CR1 MoAb-treated mice had clinical symptoms of arthritis compared with 58% of the control animals (P < 0.01) . The severity of arthritis, expressed as mean arthritic index, was 2.9 +/- 0.5 and 1.4 +/- 0.5, respectively (P = 0.004) . Fifteen days after bacterial inoculation, all CR1 MoAb-treated mice had severe arthritis (mean arthritic index 6.3 +/- 0.6), while only 77% of controls were affected (mean arthritic index 2.9 +/- 0.6; P = 0.002) . The potential explanation of these findings is that treatment with CR1 MoAb significantly increases the polymorphonuclear cell-dependent inflammatory response as a result of enhanced vasodilatation in treated animals . We conclude that treatment with CR1 MoAb leads to amelioration of sepsis-induced mortality during S . aureus infection, possibly as a result of the increased phagocytic activity of peripheral phagocytes.

Scand J Infect Dis, 1999, 31(2), 208 - 9
Postoperative toxic shock syndrome caused by a highly virulent methicillin-resistant Staphylococcus aureus strain; Cui L et al.; We report on a rare fatal case of postoperative toxic shock syndrome caused by infection with a highly virulent methicillin-resistant Staphylococcus aureus strain, designated Sak-1, which was found to be characteristic in its increased production of toxic shock syndrome toxin 1 in human whole blood (about 30-fold more than produced in Tod Hewitt broth) . The strain also produced a high level of toxic shock syndrome toxin 1 in the circulating blood of mice experimentally infected with the strain.

Scand J Infect Dis, 1999, 31(2), 173 - 7
Interference of the antimicrobial peptide lactoferricin B with the action of various antibiotics against Escherichia coli and Staphylococcus aureus; Vorland LH et al.; The antimicrobial peptide, lactoferricin, can be generated upon gastric pepsin cleavage of lactoferrin . We have examined the interaction of lactoferricin of bovine origin, Lf-cin B, with the antibiotics penicillin G, vancomycin, gentamicin, colistin, D-cycloserine and erythromycin against E . coli ATCC 25922 and Staphylococcus aureus ATCC 25923 . We demonstrated synergism between Lf-cin B and erythromycin against E . coli, and partial synergism between Lf-cin B and penicillin G, vancomycin and gentamicin against E . coli . Only penicillin G acted in partial synergism with Lf-cin B against S . aureus . Lf-cin B antagonized vancomycin and gentamicin against S . aureus in low concentration . We conclude that Lf-cin B may facilitate the uptake of antibiotics across the cell envelope.

Acta Paediatr, 1999 Jul, 88(7), 776 - 9
Staphylococcal scalded skin syndrome: exfoliative toxin A (ETA) induces serine protease activity when combined with A431 cells; Ladhani S et al.; Staphylococcal scalded skin syndrome is the term used for a spectrum of primarily neonatal blistering skin diseases caused by the exfoliative toxins, ETA and ETB, of Staphylococcus aureus . Despite 25 y of research, the toxins' mechanism of action is still poorly understood, although evidence suggests that they may act as serine proteases . In this study, 0.1 mg purified ETA isolated from a baby with pemphigus neonatorum was incubated with A431 cells (a human squamous cell line) at 37 degrees C for 8, 24 and 48 h and the supernatant tested for protease activity using azocasein as a non-specific substrate . Phosphate-buffered saline was also incubated as negative control . Incubation of ETA with A431 cells for 48 h resulted in a four-fold increase in supernatant azocaseinolytic activity compared with buffer and cells, ETA alone and buffer alone (p < 0.001) . Furthermore, this proteolytic activity was inhibited by PMSF (p < 0.001), a specific serine protease inhibitor . These results provide further evidence for the role of the exfoliative toxins as serine proteases . Furthermore, the A431 cell assay provides a simpler, quicker, cheaper and more acceptable alternative to neonatal mouse epidermis to study the mechanism of action of the exfoliative toxins.

Pediatr Res, 1999 Aug, 46(2), 200 - 7
Human milk effects on neutrophil calcium metabolism: blockade of calcium influx after agonist stimulation; Chacon-Cruz E et al.; Neutrophils are the predominant cellular mediators of acute inflammation, and human milk suppresses multiple neutrophil functions . We sought to determine whether these effects were mediated through disruption of normal intracellular Ca2+ homeostasis . Exposure of human neutrophils to human milk, followed by washing, resulted in altered Ca2+ transient responses to formyl-peptide stimulation in which the peak cytosolic free Ca2+ concentration ({free Ca}) was the same as in unexposed cells, but the postpeak decline in {free Ca} was more rapid . This effect was observed after human milk exposures as brief as 10 s, persisted for up to 4 h after human milk removal, and was concentration dependent . On the basis of experiments examining Ca2+-free conditions followed by Ca2+ supplementation, and experiments examining spontaneous and stimulated manganese and barium influx into neutrophils, the human milk effect was due to blockade of Ca2+ influx . Decreased Ca2+ transient responses to other physiologic stimuli (IL-8, opsonized Staphylococcus aureus, and immune complexes) were observed after human milk exposures . Rat intestinal epithelial cells and HL-60 cells failed to show these effects, suggesting a selective effect on mature inflammatory cells . Characterization of the Ca2+-blocking activity showed it was heat and acid stable in human milk with a molecular mass between 30-100 kD . Commercial human milk lactoferrin exhibited Ca2+ influx blockade activity, but recombinant human lactoferrin showed none . Separation of the activity by heparin affinity chromatography showed that it was distinct from lactoferrin . Human milk-induced blockade of Ca2+ influx provides a potential mechanism for broad suppression of neutrophil functions that may contribute to the antiinflammatory properties of human milk.

J Biol Chem, 1999 Aug 20, 274(34), 24316 - 20
Anchor structure of staphylococcal surface proteins . IV . Inhibitors of the cell wall sorting reaction; Ton-That H et al.; Surface proteins of Staphylococcus aureus are covalently linked to the bacterial cell wall by a mechanism requiring a COOH-terminal sorting signal with a conserved LPXTG motif . Cleavage between the threonine and the glycine of the LPXTG motif liberates the carboxyl of threonine to form an amide bond with the amino of the pentaglycine cross-bridge in the staphylococcal peptidoglycan . We asked whether antibiotic cell wall synthesis inhibitors interfere with the anchoring of surface proteins . Penicillin G, a transpeptidation inhibitor, had no effect on surface protein anchoring, whereas vancomycin and moenomycin, inhibitors of cell wall polymerization into peptidoglycan strands, slowed the sorting reaction . Cleavage of surface protein precursors did not require a mature assembled cell wall and was observed in staphylococcal protoplasts . A search for chemical inhibitors of the sorting reaction identified methanethiosulfonates and p-hydroxymercuribenzoic acid . Thus, sortase, the enzyme proposed to cleave surface proteins at the LPXTG motif, appears to be a sulfhydryl-containing enzyme that utilizes peptidoglycan precursors but not an assembled cell wall as a substrate for the anchoring of surface protein.

Science, 1999 Aug 13, 285(5430), 1074 - 7
Insights into editing from an ile-tRNA synthetase structure with tRNAile and mupirocin; Silvian LF et al.; Isoleucyl-transfer RNA (tRNA) synthetase (IleRS) joins Ile to tRNA(Ile) at its synthetic active site and hydrolyzes incorrectly acylated amino acids at its editing active site . The 2.2 angstrom resolution crystal structure of Staphylococcus aureus IleRS complexed with tRNA(Ile) and Mupirocin shows the acceptor strand of the tRNA(Ile) in the continuously stacked, A-form conformation with the 3' terminal nucleotide in the editing active site . To position the 3' terminus in the synthetic active site, the acceptor strand must adopt the hairpinned conformation seen in tRNA(Gln) complexed with its synthetase . The amino acid editing activity of the IleRS may result from the incorrect products shuttling between the synthetic and editing active sites, which is reminiscent of the editing mechanism of DNA polymerases.

Ann Med Interne (Paris), 1999 Apr, 150(3), 265 - 8
{Systemic infection due to implanted leads of a cardiac pacemaker . Apropos of a case and review of the literature}; Delpierre S et al.; Systemic infection related to transvenous pacemaker-leads are rare, but their diagnosis is difficult . We report the observation of a 78-year-old patient whose recurrent Staphylococcus aureus septicemias linked to endocarditis related to an endovascular lead only on a third observation, characterized by an infectious bone localization . Transoesophageal echocardiography appears as the reference diagnostic method . The treatment lies in the surgical ablation of the pacing system and a prolonged antibiotic therapy . The heavy mortality caused by these pathologies leads us to reconsider the interest of a prophylaxis, particularly for elderly patients.

Alcohol Clin Exp Res, 1999 Jul, 23(7), 1199 - 206
Immune changes in alcohol-dependent patients without medical disorders; Schleifer SJ et al.; INTRODUCTION: We examined a battery of in vitro immune measures in inner city alcohol-dependent (as determined by the Structured Clinical Interview for DSM-III-R (SCID) persons who were without liver or other medical disorders and free of other substance abuse . These subjects were seeking treatment at an ambulatory alcohol treatment center . METHODS: Alcohol-dependent subjects (n = 44) were compared with healthy, nonabusing community subjects (n = 34) . Subjects, both male and female, had a mean age of 41 years and were primarily African American . Many were homeless . An extended battery of enumerative and functional immune measures was obtained, as well as information about alcohol consumption . RESULTS: CONTROLLING for age and gender, ANCOVA revealed no differences (p > 0.1) between alcohol-dependent and control subjects in leukocyte and lymphocyte subsets or in circulating CD56+ (natural killer) cells . There were also no significant differences in responses to the mitogens phytohemagglutinin, concanavalin A, or pokeweed mitogen ( > 0.1) or in natural killer cell activity (p > 0.1) . There was, however, altered granulocyte function in the alcohol-dependent sample, with decreased phagocytic activity in the alcohol-dependent males (p < 0.04) and gender and age dependent differences in the number of circulating granulocytes (p < 0.01) . Granulocyte killing of Staphylococcus aureus, however, did not differ between the groups . CONCLUSIONS: The findings suggest that although males with chronic alcohol dependence have compromised phagocytic function, chronic alcohol-dependent subjects who are free of medical disorders do not have substantial abnormalities in many immune system functions.

FEMS Immunol Med Microbiol, 1999 Aug 1, 25(1-2), 207 - 19
Pyrogenic toxins of Staphylococcus aureus in sudden unexpected nocturnal deaths in adults and older children: factors influencing the control of inflammatory responses to toxic shock syndrome toxins; Al Madani O et al.; Sudden unexpected nocturnal deaths (SUND) occur in young immigrant workers, mainly from south-east Asia, who are employed in countries such as Singapore and Saudi Arabia . Pyrogenic toxins of Staphylococcus aureus have been identified in two cases of sudden unexpected death in adults in the UK and it has been suggested that these or other toxins with superantigen properties might induce strong inflammatory responses leading to sudden unexpected nocturnal deaths . The objectives of the present study were (1) to assess the levels of antibodies to pyrogenic staphylococcal toxins in the general population, (2) to assess the levels of IgG to the toxins needed to reduce the production of inflammatory mediators by 50% in a model system, (3) to assess in a model system the effects on inflammatory responses to toxic shock syndrome toxin-1 (TSST) of cortisol levels present at night, during the day and under conditions of physiological stress . Enzyme linked immunosorbent assays were used to assess levels of IgG to TSST, staphylococcal enterotoxin A (SEA) and staphylococcal enterotoxin C (SEC) . Human buffy coats were used to examine the effect of IgG to the toxins for neutralising activity and the effect of cortisol on induction of inflammatory mediators . Tumour necrosis factor alpha (TNF-alpha) was detected by a bioassay with L929 cells, interleukin-6 (IL-6) and interleukin-10 (IL-10) were measured by an enzyme linked immunosorbent assay . IL-6 and TNF-alpha levels elicited by the toxins were not reduced by night time levels of cortisol (5-10 microg dl(-1)) levels . Day time levels of cortisol (10-20 microg dl(-1)) significantly inhibited IL-6 production but not TNF-alpha in responses . Stress levels of cortisol (40 80 microg dl(-1)) significantly reduced all three cytokines earlier than the normal day time levels . The majority of the population tested had sufficient antibodies to reduce TNF-alpha and IL-6 responses elicited by TSST and SEC in the model system . In the age range in which most sudden unexpected nocturnal death cases occur (20-39 years), males had significantly lower levels of IgG to TSST compared with females . If these toxins play a role in precipitating the series of events leading to sudden unexpected nocturnal death, the higher levels of IgG to the toxins observed in females might explain partly the much higher prevalence of these deaths among men in this age range . If inflammatory responses play a role in sudden unexpected nocturnal death, the inability of the night time levels of cortisol to control IL-6 and TNF-alpha in the model system might reflect these interactions in vivo . The methods developed for detection of the toxins in tissue samples and the quantitative IgG assays for anti-toxins can be applied to investigation of SUND victims to test the hypothesis that some of these deaths are precipitated by pyrogenic staphylococcal toxins.

FEMS Immunol Med Microbiol, 1999 Aug 1, 25(1-2), 183 - 92
The protective effect of immunisation against diphtheria, pertussis and tetanus (DPT) in relation to sudden infant death syndrome; Essery SD et al.; Epidemiological evidence indicates infants immunised against diphtheria, pertussis and tetanus (DPT) are at decreased risk of sudden infant death syndrome (SIDS) . Asymptomatic whooping cough and pyrogenic toxins of Staphylococcus aureus have been implicated in the aetiology of SIDS . The objectives of the present study were: (1) to determine if the DPT vaccine induced antibodies cross-reactive with the staphylococcal toxins; (2) to determine if antibodies to the pertussis toxin (PT) and the staphylococcal toxins were present in the sera of women during late pregnancy; (3) to examine the effects of infant immunisation on levels of antibodies to PT and the staphylococcal toxins; (4) to assess the effects of changes in immunisation schedules in the UK on the incidence and age distribution of SIDS . Enzyme-linked immunosorbent assays (ELISA) were used to measure binding of rabbit or human IgG to the DPT vaccine, PT, toxic shock syndrome toxin-1 (TSST-1) and staphylococcal enterotoxins A (SEA), B (SEB) and C (SEC) . Neutralisation activity of anti-DPT serum was assessed by a bioassay for induction of nitric oxide from human monocytes by the staphylococcal toxins . Anti-DPT serum bound to the DPT vaccine, PT and each of the staphylococcal toxins . It also reduced the ability of the four toxins to induce nitric oxide from monocytes . In pregnant women, levels of IgG to PT, SEC and TSST-1 decreased significantly in relation to increasing weeks of gestation while antibodies to SEA and SEB increased . In infants' sera there were significant correlations between levels of IgG bound to DPT and IgG bound to PT, TSST-1 and SEC but not SEA or SEB . Antibody levels to the toxins in infants declined with age; sera from infants < or = 2 months of age had higher levels of IgG bound to the toxins than those older than 2 months . This pattern was observed for infants whose immunisation schedules began at 2 months of age or 3 months of age . The decrease in IgG bound to the toxins was, however, less for those immunised at 2 months . The decrease in SIDS deaths after the change in immunisation schedules was greatest in the 4-6-month age range . While DPT immunisation might prevent some unexplained infant deaths due to asymptomatic whooping cough, these data indicate that immunisation with DPT also induces antibodies cross-reactive with pyrogenic staphylococcal toxins implicated in many cases of SIDS . Passive immunisation of infants who have low levels of these antibodies might reduce further the numbers of these infant deaths.

FEMS Immunol Med Microbiol, 1999 Aug 1, 25(1-2), 155 - 65
The protective effect of breast feeding in relation to sudden infant death syndrome (SIDS): I . The effect of human milk and infant formula preparations on binding of toxigenic Staphylococcus aureus to epithelial cells; Saadi AT et al.; Epidemiological studies indicate that breast-fed infants are at a decreased risk of sudden infant death syndrome (SIDS) compared to formula-fed infants . Increasing evidence suggests that infectious agents might be involved in some of these deaths, in particular bacteria which colonise mucosal surfaces and produce superantigenic toxins . One species implicated in recent studies of SIDS infants is Staphylococcus aureus . We tested the hypothesis that in comparison to infant formula, human milk might be a better inhibitor of binding of S . aureus to epithelial cells . In this study, two protocols were used for the binding assays which were assessed by flow cytometry: the in vitro method in which bacteria were treated with milk or formula, washed and added to epithelial cells; and a method more closely reflecting the competitive interactions in vivo in which cells, bacteria, and milk or infant formula were added at the same time . With the in vivo method, breast milk caused enhancement of bacterial binding to cells whilst infant formula caused inhibition; however, for the in vitro method, both human milk and infant formula caused consistent enhancement of binding . Flow cytometry and light microscopy studies indicated that the enhancement was due to the formation of bacterial aggregates . Human milk and infant formula preparations were also compared for components (antibodies or oligosaccharides) that could inhibit binding of S . aureus using the in vitro method . Human milk contained both IgA and IgG . Neither human milk nor infant formula contained oligosaccharides reactive with the Ulex europaeus lectin but both contained components that bound monoclonal antibodies to Lewis(a) and Lewis(b) antigens which can act as receptors for S . aureus . With both methods, synthetic Lewis(a) and Lewis(b) inhibited S . aureus binding in a dose-dependent manner . With human milk, however, the only component which showed a significant correlation with inhibition of binding was the IgA specific for the staphylococcal surface component that binds Lewis(a) . Both human milk and infant formula contain components which could potentially inhibit bacterial binding but only breast milk contains the IgA specific for the bacterial adhesin that binds Lewis(a) . Studies using the in vivo method suggest that protection associated with breast feeding in relation to SIDS could be due mainly to the formation of bacterial aggregates . The studies have implications for further research into constituents of infant formula.

FEMS Immunol Med Microbiol, 1999 Aug 1, 25(1-2), 145 - 54
Exposure to cigarette smoke, a major risk factor for sudden infant death syndrome: effects of cigarette smoke on inflammatory responses to viral infection and bacterial toxins; Raza MW et al.; Exposure to cigarette smoke is a major risk factor for sudden infant death syndrome and also for respiratory infections in children . It has been suggested that toxigenic bacteria colonizing the respiratory tract might play a role in some cases of sudden infant death syndrome and nicotine has been demonstrated to enhance the lethality of bacterial toxins in a model system . Pyrogenic toxins of Staphylococcus aureus have been identified in tissues of infants who died of sudden infant death syndrome . It has been suggested that some of these deaths were due to induction of inflammatory mediators by infectious agents during a period when infants are less able to control these responses . The aim of this study was to assess the effects of a water-soluble cigarette smoke extract on the production of tumor necrosis factor alpha and nitric oxide from human monocytes in response to staphylococcal toxic shock syndrome toxin 1 or infection of the monocytes with respiratory syncytial virus . Cell culture supernatants were examined by a bioassay using mouse fibroblasts (L-929 cell line) for tumor necrosis factor alpha activity and by a spectrophotometric method for nitrite . Compared with monocytes incubated with medium only, monocytes incubated with any of the factors or their combinations tested in the study released higher levels of tumor necrosis factor alpha and lower levels of nitric oxide . Incubation with cigarette smoke extract increased tumor necrosis factor alpha from respiratory syncytial virus-infected cells while it decreased tumor necrosis factor alpha from cells incubated with toxic shock syndrome toxin . Incubation with cigarette smoke extract decreased the nitric oxide production from respiratory syncytial virus-infected cells while it increased the nitric oxide production from cells incubated with toxic shock syndrome toxin . Monocytes from a minority of individuals demonstrated extreme tumor necrosis factor alpha responses and/or very high or very low nitric oxide . The proportion of samples in which extreme responses with a very high tumor necrosis factor alpha and very low nitric oxide were detected was increased in the presence of the three agents to 20% compared with 0% observed with toxic shock syndrome toxin 1 or 4% observed with cigarette smoke extract or respiratory syncytial virus.

FEMS Immunol Med Microbiol, 1999 Aug 1, 25(1-2), 109 - 13
The effect of prone posture on nasal temperature in children in relation to induction of staphylococcal toxins implicated in sudden infant death syndrome; Molony N et al.; The incidence of sudden infant death syndrome (SIDS) has declined in response to campaigns discouraging the prone sleeping position . Recent work suggests some SIDS death may be in response to bacterial toxins produced in the upper airway . A minimal temperature of 37 degrees C is required for induction of the pyrogenic toxins of Staphylococcus aureus identified in many SIDS infants . This aim of this study was to test the hypothesis that the prone position raises the temperature of the upper airways in children . A pilot study of 10 children (aged 3-8) and a main study of 30 children were carried out . Nasal septal temperatures were measured with an infra-red thermometer with the subjects in upright and prone positions under controlled conditions of ambient temperature and humidity . In both the pilot study and main study, nasal temperatures in the prone position were significantly higher (P < 0.01) Five subjects' prone readings were 37 degrees C or higher . These findings suggest that lying prone raises the upper airway surface temperature towards that required for toxin production . This could be one means by which the prone sleeping position contributes to the risk of SIDS.

FEMS Immunol Med Microbiol, 1999 Aug 1, 25(1-2), 103 - 8
Detection of pyrogenic toxins of Staphylococcus aureus in sudden infant death syndrome; Zorgani A et al.; It has been suggested that pyrogenic toxins of Staphylococcus aureus are involved in the series of events leading to some cases of sudden infant death syndrome (SIDS) . The objectives of the study were to screen tissues from SIDS infants for pyrogenic toxins and to compare incidence of identification of these toxins among these infants from different countries . An enzyme-linked immunosorbent assay (ELISA) and a flow cytometry method were used to screen body fluids and frozen or formalin-fixed tissues for pyrogenic toxins of S . aureus, toxic shock syndrome toxin 1 (TSST), staphylococcal enterotoxins A (SEA), B (SEB), and C1 (SEC) . Toxins were identified in tissues of 33/62 (53%) SIDS infants from three different countries: Scotland (10/ 19, 56%); France (7/13, 55%); Australia (16/30, 53%) . In the Australian series, toxins were identified in only 3/19 (16%) non-SIDS deaths (chi2 = 5.42, P < 0.02) . The flow cytometry method was useful for toxin detection in both frozen and fixed tissues, but ELISA was suitable only for frozen tissues or those fixed for less than 12 months . Identification of pyrogenic toxins in > 50% of SIDS infants from three different countries indicated further investigation into the role the toxins play in cot deaths might result in development of additional measures to reduce further the incidence of these infant deaths.

Minerva Chir, 1999 May, 54(5), 319 - 23
{Surgical wound infection . Review of the guidelines and results of a prevalence study by the Presidio Ospedaliero de Voghera}; Cestari V et al.; BACKGROUND: A prevalence study regarding hospital acquired infections and particularly surgical wound infections was performed from 17-4-1995 to 17-7-1995 in the Voghera hospital, a large one in Northern Italy . METHODS: The records of all subjects who have operated since at least 24 hours have been checked and the surgical wounds have been classified according to the guidelines of CDC (Atlanta) . RESULTS: The prevalence rate of surgical wound infections was 13.73% of operated patients, confirming the seriousness of the problem of nosocomial infections surveillance . Pseudonomas aeruginosa (31.27%) and Staphylococcus aureus (21.92%) were the most frequently isolated organisms . CONCLUSIONS: Finally, behaviour guideline have been reproposed to try to reduce surgical wound infections for a best Quality of care in the light of a Regional credit.

J Formos Med Assoc, 1999 Jun, 98(6), 452 - 4
Primary iliac muscle abscess due to Staphylococcus aureus; Liu KY et al.; A 55-year-old man presented with a 3-day history of lower back pain and right thigh pain . A diagnosis of discogenic pain had been made at two other hospitals . He had been admitted to a medical center for acute hepatitis 5 months prior to this admission . Large doses of parenteral hydrocortisone were used for 13 days to treat acute hepatitis . At the present admission, he was unable to stand and refused to move his right leg . There was mild tenderness in the right lower abdomen on deep palpation . Passive flexion and rotation of the right hip produced mild pain, while passive extension of the right hip produced severe pain and resistance . The Patrick test was positive and the psoas sign was present on the right side . The erythrocyte sedimentation rate (ESR) was 66/hr . The C-reactive protein (CRP) level was 0.161 g/L . Abdominal sonography showed a lobulated mass in the right iliac fossa . Magnetic resonance imaging showed severe swelling of the right iliac muscle with a central heterogeneous mass . Debridement, drainage of the abscess, and application of a septopal chain were performed via an anterior retroperitoneal approach, and parenteral cephazolin and gentamicin were administered . A culture of the abscess grew Staphylococcus aureus . The ESR and CRP concentrations decreased to within the normal ranges 3 weeks later . Awareness of this disease entity, careful physical examination, and appropriate imaging studies such as ultrasonography and magnetic resonance imaging are key to making a correct diagnosis.

J Formos Med Assoc, 1999 Jun, 98(6), 426 - 32
Longitudinal analysis of methicillin-resistant Staphylococcus aureus isolates at a teaching hospital in Taiwan; Chen ML et al.; In Taiwan, the frequency of nosocomial infections caused by methicillin-resistant Staphylococcus aureus (MRSA) has increased rapidly during the past 10 years . To investigate the epidemiology of MRSA infections, a total of 140 MRSA isolates collected at National Taiwan University Hospital from 1992 to 1996 were characterized by pulsed-field gel electrophoresis (PFGE) profiles and antibiotypes, as determined with the disk diffusion method . Among these isolates, six PFGE types (with 20 subtypes) and six antibiotypes were identified . Antibiotyping proved to be a poor method of epidemiologic analysis, because almost all of the MRSA isolates analyzed shared a very similar multidrug-resistant antibiotype . Most MRSA infections and colonizations in this hospital were due to the spread of strains belonging to three major PFGE types (A, B, and C) . However, the major type changed in different years with types A, B, and C being predominant in 1992 through 1993, 1994 through 1995, and 1996, respectively . The three major PFGE types spread easily throughout the hospital wards, presumably carried by health care workers and environmental contamination . Our results demonstrate that there was a dominant strain spreading in our hospital each year and the dominant strain may shift in different years.

Eur J Clin Microbiol Infect Dis, 1999 Jun, 18(6), 393 - 8
Molecular characterization and transfer among Staphylococcus strains of a plasmid conferring high-level resistance to mupirocin; Bastos MC et al.; In this work, mupirocin resistance was correlated with the presence of plasmids in methicillin-resistant Staphylococcus aureus (MRSA) strains isolated in the Rio de Janeiro Federal University Hospital in Brazil, where topical mupirocin has been used extensively since 1990 . Of 19 strains studied, those exhibiting high-level resistance carried a large and relaxable plasmid of about 35 kb . Mupirocin-sensitive derivatives, obtained by growth at 42 C of a strain exhibiting high-level resistance, were devoid of the large plasmid, which was designated pMG1 . Mupirocin resistance was transferred to strain RN8411 during overnight filter-matings at low frequencies (7.0 x 10(-9)/donor) . The pMG1 plasmid was shown to be responsible for high-level mupirocin resistance in our isolates and to be incompatible with pGO1 . Hybridization experiments suggested that mupirocin resistance in pMG1 is due to the presence of the ileS-2 gene . The pMG1 plasmid was successfully and bidirectionally transferred from Staphylococcus aureus to Staphylococcus epidermidis, suggesting that the latter may be a reservoir of this resistance plasmid . No transfer was detected to Staphylococcus haemolyticus . The development of self-transferable high-level mupirocin resistance should be considered when using mupirocin to control the spread of MRSA in hospitals.

Biochemistry, 1999 Aug 10, 38(32), 10533 - 42
Interactions of soluble penicillin-binding protein 2a of methicillin-resistant Staphylococcus aureus with moenomycin; Graves-Woodward K et al.; Kinetics studies in homogeneous aqueous solution showed that solubilized penicillin-binding protein 2a (sPBP2a) of methicillin-resistant Staphylococcus aureus (a bacterial DD-peptidase) was inhibited by the amphiphilic glycolipid antibiotic moenomycin . Inhibition at the peptidase site was determined by competition experiments between moenomycin and the chromophoric beta-lactam nitrocefin . Under conditions of high salt concentration (1 M NaCl), pseudo-first-order rate constants for the reaction of moenomycin with sPBP2a leading to inhibition of acylation by nitrocefin varied with moenomycin concentration in a biphasic fashion . At low moenomycin concentration (<20 microM) little inhibition occurred, but at higher concentrations a linear increase in rate constant with moenomycin concentration was observed, yielding a second-order rate constant of inhibition of 120 s(-)(1) M(-)(1) . Since the cmc of moenomycin under these conditions was shown to be ca . 20 microM, the inhibition was concluded to arise from reaction of sPBP2a with a moenomycin micelle . Protein fluorescence studies showed a pseudo-first-order decrease in fluorescence on reaction of the protein with moenomycin . The variation of this rate constant with moenomycin concentration was consistent with reaction of a moenomycin monomer with the protein with a second-order rate constant of 650 s(-)(1) M(-)(1) . This monomer reaction did not occur at the DD-peptidase site since its rate was unaffected by prior acylation of the enzyme by benzylpenicillin; nor did it inhibit reaction at that site by beta-lactams . Under low salt conditions (0.175 M NaCl) where reaction could be studied over a greater range of monomer concentrations since the cmc was ca . 120 microM, similar reactions were involved . Under these circumstances, inhibition was concerted with the reaction of moenomycin monomers, although fast premicellar aggregation of moenomycin with the protein also occurred . All moenomycin interactions with sPBP2a were reversible, as revealed by detergent-extraction chromatography . Lower limits to moenomycin off-rates and equilibrium dissociation constants were 7.7 x 10(-)(4) s(-)(1) and 1.2 microM, respectively . Other amphiphiles did not react in exactly the same manner as moenomycin, indicating some degree of specificity in reactions of the latter . sPBP2a did not have detectable affinity for lipid surfaces (Triton X-114 and phosphatidylglycerol vesicles) . A general scheme for reaction of moenomycin with sPBP2a is proposed.

J Hosp Infect, 1999 Jul, 42(3), 205 - 12
PCR-RFLP analysis of the coagulase gene of Staphylococcus aureus: application to the differentiation of epidemic and sporadic methicillin-resistant strains; Hookey JV et al.; Preventing cross-infection with epidemic strains of methicillin-resistant Staphylococcus aureus (MRSA) requires effective control measures . These call for simple, rapid, discriminatory and reproducible methods for typing this pathogen . In this study 140 isolates/strains from 105 hospitals in England and Wales, representing 72 diverse phage types, were analysed by bacteriophage typing and PCR coagulase (coa) gene restriction fragment length polymorphism (RFLP) . Isolates gave a coa gene PCR product that was either 660 base pairs (bp), 603 bp or 547 pb in size . The PCR products were digested with Alu I and Cfo I, and the fragments separated by gel electrophoresis . Eight coa gene RFLP patterns, numbered 1 to 8, were observed . Pattern 3 was most common (N = 25 isolates), followed by patterns 2 and 5 (18 isolates each), pattern 1 (14 isolates), pattern 4 (11 isolates), pattern 7 (10 isolates), pattern 8 (eight isolates) and pattern 6 (six isolates) . Isolates of the same phage type often gave different coa gene RFLP patterns, and the patterns within the epidemic types EMRSA-03, EMRSA-15 and EMRSA-16 were heterogeneous . Thus, representatives of EMRSA-03 were subtyped to coa RFLP patterns 1 and 2, those of EMRSA-05 to coa RFLP patterns 1, 2, 7 and 8, and those for EMRSA-16 to coa RFLP patterns 2, 3, 4, 5 and 6 . The range of patterns within single phage types of S . aureus could help to discriminate between isolates/strains, and in a hierarchical approach coa gene RFLP could occupy an intermediate position between phage typing and pulsed-field gel electrophoresis (PFGE).

J Bacteriol, 1999 Aug, 181(16), 4818 - 24
Staphylococcus aureus cap5P encodes a UDP-N-acetylglucosamine 2-epimerase with functional redundancy; Kiser KB et al.; The serotype 5 capsule gene cluster of Staphylococcus aureus comprises 16 genes (cap5A through cap5P), but little is known about how the putative gene products function in capsule biosynthesis . We propose that the N-acetylmannosaminuronic acid (ManNAcA) component of the S . aureus serotype 5 capsular polysaccharide (CP5) is synthesized from a UDP-N-acetylglucosamine (UDP-GlcNAc) precursor that is epimerized to UDP-N-acetylmannosamine (UDP-ManNAc) and then oxidized to UDP-ManNAcA . We report the purification and biochemical characterization of a recombinant UDP-GlcNAc 2-epimerase encoded by S . aureus cap5P . Purified Cap5P converted approximately 10% of UDP-GlcNAc to UDP-ManNAc as detected by gas chromatography-mass spectrometry . The epimerization of UDP-GlcNAc to UDP-ManNAc occurred over a wide pH range and was unaffected by divalent cations . Surprisingly, CP5 expression in S . aureus was unaffected by insertional inactivation of cap5P . Sequence homology searches of the public S . aureus genomic databases revealed the presence of another putative UDP-GlcNAc 2-epimerase on the S . aureus chromosome that showed 61% identity to Cap5P . Redundancy of UDP-GlcNAc 2-epimerase function in S . aureus was demonstrated by cloning the cap5P homologue from strain Newman and complementing an Escherichia coli rffE mutant defective in UDP-GlcNAc 2-epimerase activity . Our results confirm the putative function of the S . aureus cap5P gene product and demonstrate the presence of a second gene on the staphylococcal chromosome with a similar function.

Blood, 1999 Aug 15, 94(4), 1348 - 58
Retinoic acid prevents phosphorylation of pRB in normal human B lymphocytes: regulation of cyclin E, cyclin A, and p21(Cip1); Naderi S et al.; The mechanisms underlying the growth-inhibitory effect of retinoids on normal human B lymphocytes are not well understood . We addressed this issue by examining the effect of retinoic acid on the cell cycle machinery involved in G1/S transition . When retinoic acid was administered to B cells stimulated into mid to late G1 by anti-IgM antibodies (anti-mu) and Staphylococcus aureus crude cell suspension (SAC), the phosphorylation of pRB required for S-phase entry was prevented in a time- and dose-dependent manner . Thus, 2-hour treatment with retinoic acid at the optimal concentration of 1 micromol/L prevented phosphorylation of pRB, and effects were noted at concentrations as low as 10 nmol/L . Based on our results, we suggest that the rapid effect of retinoic acid on pRB phosphorylation is due primarily to the reduced expression of cyclin E and cyclin A in late G1 . This could lead to the diminished cyclin E- and cyclin A-associated kinase activities noted as early as 2 hours after addition of retinoic acid . Furthermore, our results imply that the transient induction of p21(Cip1) could also be involved . Thus, retinoic acid induced a rapid, but transient increased binding of p21(Cip1) to CDK2 . The retinoic acid receptor (RAR) agonist TTNPB mimicked the key events affected by retinoic acid, such as pRB phosphorylation, cyclin E expression, and expression of p21(Cip1), whereas the RAR-selective antagonist Ro 41-5253 counteracted the effects of retinoic acid . This implies that retinoic acid mediates its growth-inhibitory effect on B lymphocytes via the nuclear receptors.

J Infect Dis, 1999 Sep, 180(3), 896 - 9
A randomized clinical trial of mupirocin in the eradication of Staphylococcus aureus nasal carriage in human immunodeficiency virus disease; Martin JN et al.; Seventy-six human immunodeficiency virus (HIV)-infected patients with Staphylococcus aureus nasal carriage were randomized to treatment groups receiving intranasal mupirocin or placebo twice daily for 5 days . Nasal cultures for S . aureus were obtained at 1, 2, 6, and 10 weeks after therapy . At 1 week, 88% of mupirocin-treated patients had negative nasal cultures compared with 8% in placebo patients (P<.001) . The percentage of mupirocin-treated patients with persistently negative nasal cultures decreased over time (63%, 45%, and 29% at 2, 6, and 10 weeks, respectively) but remained significantly greater than the placebo group (3% at 2, 6, and 10 weeks) . In mupirocin-treated patients, most (16/19) instances of nasal recolonization were with pretreatment strains (determined by means of by pulsed field gel electrophoresis); mupirocin resistance was not observed . Five days of treatment with mupirocin eliminated S . aureus nasal carriage in HIV-infected patients for several weeks; however, since the effect waned over time, intermittent dosing regimens should be considered for long-term eradication.

Vet Immunol Immunopathol, 1999 May, 68(2-4), 169 - 76
Diapedesis across mammary epithelium reduces phagocytic and oxidative burst of bovine neutrophils; Smits E et al.; The effect of diapedesis on the phagocytic and oxidative burst activity of polymorphonuclear neutrophil (PMN) was examined, using an in vitro cell culture model consisting of a monolayer of primary mammary epithelial cells . Isolated blood PMN from 10 cows were added to the basal side of the epithelial cell monolayer . Diapedesis was induced by the addition of complement factor C5a to the apical side of the monolayer . PMN phagocytosis of Staphylococcus aureus and oxidative burst were measured before diapedesis on PMN that were non-activated and activated by incubation with C5a and on PMN after diapedesis, using flow cytometry . The percentages of PMN fluorescing due to phagocytosis of S . aureus and oxidative burst were reduced by 21.2 and 14.4%, respectively, after diapedesis . Pre-incubation in the presence of C5a had no effect on percentage PMN fluorescing due to phagocytosis or oxidative burst . The capacity for individual migrated PMN to phagocytose S . aureus and to produce an oxidative burst, as measured by the intensity of fluorescence, decreased by 34.2 and 30.3% . Activation of PMN with C5a increased intensity due to the oxidative burst, but had no effect on intensity due to phagocytosis . These data show that PMN diapedesis across mammary epithelium results in decreased phagocytosis and oxidative burst of the PMN.

Arch Pediatr Adolesc Med, 1999 Aug, 153(8), 864 - 8
Methicillin-resistant Staphylococcus aureus carriage in a child care center following a case of disease . Toronto Child Care Center Study Group; Shahin R et al.; OBJECTIVES: To study the prevalence of methicillin sodium-resistant and methicillin-sensitive Staphylococcus aureus colonization in a child care center following the diagnosis of community-acquired methicillin-resistant S . aureus (MRSA) disease in a previously well 2 1/2-year-old attendee and to determine the optimal site of detection of S . aureus . DESIGN: Point prevalence survey and questionnaire administration . SETTING: A Toronto, Ontario, child care center . INTERVENTIONS: Parents were provided with general information . Consenting parents completed a questionnaire and permitted screening of their child at 1 or more of throat, nose, and perianal sites . Families of children who were culture positive for MRSA were offered screening and suppressive therapy . Nasal and perianal swabs were obtained from child care center staff and screened . RESULTS: Of 201 children, 164 (81.6%) had completed questionnaires and had undergone screening at 1 or more sites; 38 staff members (100%) completed questionnaires and were screened . A 26-month-old classroom contact with chronic dermatitis had MRSA detected only on perianal swab . Of 3 adult household contacts of the index case and 2 adult and 1 child contacts of the classroom contact, only the 7-year-old sibling of the classroom contact was positive for MRSA . By pulse-field gel electrophoresis, these isolates were identical and not related to any of the common strains circulating in regional health care institutions . Of 40 children with S . aureus (24.4%), 33 had cultures at 3 sites, of which the throat was more sensitive (22 {67%}) than the nostrils (15 {46%}) or perianal sites (8 {24%}) . There was a tendency for higher carriage of S . aureus in children with certain risk factors, including personal hospitalization (prevalence ratio, 2.9; 95% confidence interval, 0.6-12.1), family member hospitalization (prevalence ratio, 2.0; 95% confidence interval, 0.6-6.6), and visiting the hospital emergency department (prevalence ratio, 3.2; 95% confidence interval, 0.7-14.5), all in the previous 6 months . CONCLUSIONS: To our knowledge, this is one of the first recognized cases of MRSA disease and apparent transmission in a child care center . Throat and perianal site screenings have a higher sensitivity in identifying children colonized with S . aureus than nasal culturing . Infection with MRSA should be suspected in disease unresponsive to standard antibiotic therapy.

Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi, 1998 Nov, 12(6), 355 - 8
{Clinical study of gentamycin-loaded chitosan drug delivery system}; Chen A et al.; An clinical and pharmacokinetic study for a drug delivery system (DDS) of gentamycin-loaded chitosan bar were carried out with the purpose to evaluate its efficacy and giving further data for its clinical applications . Eighteen cases of chronic osteomyelitis were treated by surgical necrectomy with implantation of gentamycin-load chitosan bar in the prepared bone cavity . After operation, the concentration of gentamycin in serum and wound drainage fluid were examined at different times and blood urea nitrogen (BUN) and serum creatinine (Cr) as well . The clinical results were evaluated by the conditions of wound healing and clinical and roentgenographic manifestations . The results showed that the serum gentamycin concentration reached its peak level (0.86 microgram/ml) at 24 hours after operation and lasted for 4 days . No increase in the concentrations of BUN and Cr were observed after implantation . The gentamycin concentration in wound drainage fluid was several hundred times higher than the minimum inhibitory concentration (MIC) for staphylococcus aureus . All of the 18 cases were followed up for 24.8 months (in an range of 6-34 months) 16 patients received initial cure and without any recurrence . So, it could be concluded that the gentamycin-loaded chitosan DDS was a simple and effective method for the treatment of chronic osteomylitis without the necessity to carry out a second operation to remove the drug carrier, and it was sound to popularize its clinical application.

FEMS Microbiol Lett, 1999 Aug 1, 177(1), 93 - 100
Transposition of IS1181 in the genomes of Staphylococcus and Listeria; Chesneau O et al.; The recombinant plasmid pIP1713 was constructed to analyse the transpositional activity of the insertion sequence IS1181 in Staphylococcus aureus RN4220, Staphylococcus carnosus TM300 and Listeria monocytogenes EGD . This 11.3-kb plasmid contains two genetically different elements: (i) a pE194ts-derived replicon, the ermC gene of which confers resistance to erythromycin in Gram-positive bacteria of several species, and (ii) a copy of IS1181, cloned from S . aureus BM3121, in which the tetracycline resistance gene, tet(T), has been inserted between the transposase-encoded gene and the downstream inverted repeat . When introduced by electroporation into the three bacterial hosts, pIP1713 delivered IS1181 omega tet(T) to various chromosomal sites . Cointegrate structures between pIP1713 and the host chromosome were occasionally detected . Transposition was associated with 8-bp repeats at the insertion sites . IS1181 omega tet(T) could be used for random mutagenesis in Gram-positive bacteria.

FEMS Microbiol Lett, 1999 Aug 1, 177(1), 15 - 22
The sae locus of Staphylococcus aureus encodes a two-component regulatory system; Giraudo AT et al.; Sae is a regulatory locus that activates the production of several exoproteins in Staphylococcus aureus . A 3.4-kb fragment of a S . aureus genomic library, screened with a probe adjacent to the transposon insertion of a sae::Tn551 mutant, was cloned into a bifunctional vector . This fragment was shown to carry the sae locus by restoration of exoprotein production in sae mutants . The sae locus was mapped to the SmaI-D fragment of the staphylococcal chromosome by pulse-field electrophoresis . Sequence analysis of the cloned fragment revealed the presence of two genes, designated saeR and saeS, encoding a response regulator and a histidine protein kinase, respectively, with high homology to other bacterial two-component regulatory systems.

Rev Inst Med Trop Sao Paulo, 1998 Nov-Dec, 40(6), 383 - 5
Visceral larva migrans and tropical pyomyositis: a case report; Lambertucci JR et al.; We report a case of tropical pyomyositis in a boy who presented with a severe febrile illness associated with diffuse erythema, and swelling in many areas of the body which revealed on operation extensive necrotic areas of various muscles that required repeated debridement . The patient gave a history of contact with dogs, and an ELISA test for Toxocara canis was positive . He also presented eosinophilia and high serum IgE levels . Staphylococcus aureus was the sole bacteria isolated from the muscles affected . We suggest that tropical pyomyositis may be caused by the presence of migrating larvae of this or other parasites in the muscles . The immunologic and structural alterations caused by the larvae, in the presence of concomitant bacteremia, would favour seeding of the bacteria and the development of pyomyositis.

Protein Eng, 1999 Jul, 12(7), 573 - 9
Relocation of the catalytic carboxylate group in class A beta-lactamase: the structure and function of the mutant enzyme Glu166-->Gln:Asn170-->Asp; Chen CC et al.; The hydrolysis of beta-lactam antibiotics by the serine-beta-lactamases proceeds via an acyl-enzyme intermediate . In the class A enzymes, a key catalytic residue, Glu166, activates a water molecule for nucleophilic attack on the acyl-enzyme intermediate . The active site architecture raises the possibility that the location of the catalytic carboxylate group may be shifted while still maintaining close proximity to the hydrolytic water molecule . A double mutant of the Staphylococcus aureus PC1 beta-lactamase, E166Q:N170D, was produced, with the carboxylate group shifted to position 170 of the polypeptide chain . A mutant protein, E166Q, without a carboxylate group and with abolished deacylation, was produced as a control . The kinetics of the two mutant proteins have been analyzed and the crystal structure of the double mutant protein has been determined . The kinetic data confirmed that deacylation was restored in E166Q:N170D beta-lactamase, albeit not to the level of the wild-type enzyme . In addition, the kinetics of the double mutant enzyme follows progressive inactivation, characterized by initial fast rates and final slower rates . The addition of ammonium sulfate increases the size of the initial burst, consistent with stabilization of the active form of the enzyme by salt . The crystal structure reveals that the overall fold of the E166Q:N170D enzyme is similar to that of native beta-lactamase . However, high crystallographic temperature factors are associated with the ohm-loop region and some of the side chains, including Asp170, are partially or completely disordered . The structure provides a rationale for the progressive inactivation of the Asp170-containing mutant, suggesting that the flexible ohm-loop may be readily perturbed by the substrate such that Asp170's carboxylate group is not always poised to facilitate hydrolysis.

Nephrol Dial Transplant, 1999 Jul, 14(7), 1710 - 4
Outcome and complications of temporary haemodialysis catheters; Kairaitis LK et al.; BACKGROUND: The use of temporary haemodialysis catheters is often complicated by mechanical or infectious complications . Risk factors for these complications and optimal management to reduce their incidence are largely unknown . METHODS: We conducted a prospective study of 105 haemodialysis catheters (79 subclavian, 26 jugular) inserted in 52 patients in order to identify patient outcomes and to analyse the effect of patient and catheter factors on the incidence of infectious complications by multivariate analysis . RESULTS: Fifty-nine per cent of catheters were removed for a suspected complication . Catheter-related bacteraemia (CRB) was diagnosed in 17 catheters (16%), giving a bacteraemia rate of 6.5 episodes per 1000 catheter days . Subgroup analysis revealed a higher risk of CRB with the use of the internal jugular compared with the subclavian site (hazard ratio 3.97, P=0.02) . Age, diabetes or catheter exchange over a guidewire did not alter the risk of CRB . The cumulative risk of developing CRB increased in a linear fashion as the period of catheterization increased . Exit-site infection was the cause for removal in eight catheters (8%) . Although the number of exit-site infections was small, the risk of exit-site infection was increased in diabetic patients (hazard ratio 10, P=0.03) and the jugular position (hazard ratio 6.5, P=0.01) but not by age or catheter exchange over a guidewire . Staphylococcus aureus and coagulase-negative staphylococcus accounted for all proven episodes of CRB . Exit-site infection was associated with a mixture of Gram-positive and Gram-negative organisms . CONCLUSIONS: Temporary haemodialysis catheters have a high failure rate associated with a significant rate of complications . Use of the internal jugular site is associated with a significantly higher risk of infectious complications and methods to reduce this risk should be considered if this site is used.

Hiroshima J Med Sci, 1999 Jun, 48(2), 49 - 56
Analysis of mec regulator genes in clinical methicillin-resistant Staphylococcus aureus isolates according to the production of coagulase, types of enterotoxin, and toxic shock syndrome toxin-1; Santo T et al.; The intrinsic resistance of methicillin-resistant Staphylococcus aureus (MRSA) is frequently explained by the production of an additional penicillin-binding protein (PBP), which is encoded by the mecA gene . The mec regulator genes, mecR1 and mecI, was identified in mecA-carrying Staphylococcus aureus N315 . Between February and March, 1993, 179 clinical MRSA isolates were collected from institutions in Hiroshima prefecture . According to serological types of coagulase, enterotoxins, and toxic shock syndrome toxin-1 (TSST-1) productions, these strains were classified into 6 groups . In 53 strains chosen from all groups, mec regulatory gene distributions were divided into two groups; one with whole regulatory genes and another with the lacking region, including 3'-partial region of the mecR1 gene and mecI gene . This same deletion was detected across the different groups, suggesting that the deletion occurred at the ancestral strain before branching according to coagulase or enterotoxin productions . The strains with this lacking region showed a high-level of resistance to methicillin, while the strains with whole regulatory genes consisted of low and high levels of resistant strains . The highly resistant strains with whole regulatory genes were found to harbor a point mutation in the mecI gene . The basal levels of mecA gene transcription were elevated in the strains with the lacking region or the mecI point mutations . These data suggest that deletion or mutation of the mecI gene, the repressor on the mecA gene, might play an important role in methicillin resistance in clinical isolates of MRSA.

Am J Pathol, 1999 Aug, 155(2), 537 - 47
Tumor-associated transforming growth factor-beta and interleukin-10 contribute to a systemic Th2 immune phenotype in pancreatic carcinoma patients; Bellone G et al.; In this study, we report coexpression of transforming growth factor-beta (TGF-beta) and interleukin-10 (IL-10) in pancreatic carcinoma tissue associated with significantly elevated levels of both cytokines in the sera of pancreatic carcinoma patients . Using conditioned media (CM) of pancreatic carcinoma cells, we further demonstrate that tumor cell-derived TGF-beta and IL-10 inhibited in an additive fashion both proliferation and the development of Th1-like responses in peripheral blood mononuclear cell (PBMC) preparations derived from normal donors . The antiproliferative and Th1-suppressive activities contained in CM of pancreatic carcinoma cells were due primarily to IL-10 and/or TGF-beta, as shown by the capacity of cytokine-specific neutralizing antibodies to reverse these effects . Finally, as compared to normal controls, PBMC derived from pancreatic carcinoma patients displayed a Th2-like cytokine expression pattern upon activation with either anti-CD3 antibody or Staphylococcus aureus strain Cowan I . Taken together, these results suggest that aberrant production of TGF-beta and IL-10 in pancreatic tumor patients skews T-cell cytokine production patterns in favor of a Th2 immunophenotype.

Am J Infect Control, 1999 Aug, 27(4), 320 - 6
Comparison of the antibacterial efficacy of 4% chlorhexidine gluconate and 1% triclosan handwash products in an acute clinical ward; Faoagali JL et al.; The antibacterial efficacy of 4% chlorhexidine gluconate (CHG) and 1% triclosan as handwash antiseptics is well established . Few published studies have identified hand bacteria found in glove juice samples, and most studies have used nonclinical study subjects.We report a longitudinal comparative study to determine the effect of 4% CHG and 1% triclosan on the composition of the hand bacterial flora of clinical staff in a specialist surgical unit . Prehandwash and posthandwash samples were collected on 3 separate occasions throughout each day by using the glove juice method and a supervised handwashing technique . Total bacterial counts were determined as well as counts for specific pathogens including methicillin-resistant Staphylococcus aureus and coliforms . Both 4% CHG and 1% triclosan were found to effectively reduce the total hand bacterial count preduty (P =.0001) . Four percent CHG also was consistently more effective at reducing the total count than was 1% triclosan . However, 1% triclosan eliminated methicillin-resistant S aureus, whereas 4% CHG failed to do so (P =.0001) . Gram-negative bacteria were more likely to be eliminated after the use of 4% CHG compared with 1% triclosan.This study is the first to report the effects of 1% triclosan on the bacterial flora present on the hands of clinical staff and demonstrates the ability of 1% triclosan to eliminate methicillin-resistant S aureus.

Clin Infect Dis, 1999 Jul, 29(1), 102 - 5
Cure of implantable venous port-associated bloodstream infections in pediatric hematology-oncology patients without catheter removal; Rubin LG et al.; The efficacy of antibiotic treatment of port-associated bloodstream infection without device removal has not been systematically studied . We analyzed the outcome of 43 consecutive port-associated bloodstream infections in pediatric hematology-oncology patients . Etiologies included Staphylococcus epidermidis (30) and Staphylococcus aureus (6) . Antibiotics were given through the port for a median of 11 days . Four ports were removed within 72 hours . In 36 (92%) of the remaining 39 episodes, there was a response to antibiotic therapy (defervescence and negative blood culture) . In 78% of episodes in which there was a response (excluding two in which the catheters were removed because of mechanical problems), the infections were cured without port removal . Two of the four relapses were cured with a second course of antibiotics . The cure rate was 92% for S . epidermidis infections and 67% for S . aureus infections . Thus, the majority of port-associated bloodstream infections in pediatric hematology-oncology patients can be cured without device removal.

Eur J Surg, 1999 Jun, 165(6), 609 - 14
Fibrinogen-impregnated collagen as a combined haemostatic agent and antibiotic delivery system in a porcine model of splenic trauma; Parker SJ et al.; OBJECTIVE: To assess the effect of rifampicin on the haemostatic function of a fibrinogen-impregnated collagen fleece . DESIGN: Laboratory experiment . SETTING: Government research establishment, UK . MATERIAL: Six Large White pigs . INTERVENTIONS: Four 5 cm incisions were made in the spleen of each animal . Three of the wounds were each covered with a sheet of either dry, saline-soaked or rifampicin-soaked fibrinogen-impregnated collagen . MAIN OUTCOME MEASURES: The bleeding time and blood loss from each wound was recorded . Systemic serum rifampicin concentrations were measured using a Staphylococcus aureus inhibition assay . RESULTS: Dry fibrinogen-impregnated collagen resulted in significantly less blood loss (112 (21) compared with 39 (13)ml, p < 0.05) and shorter bleeding time (16 (2) compared with 9 (1) min, p < 0.01) than in untreated control wounds . Pre-soaking in saline or rifampicin solution had no significant effect on its haemostatic function . Rifampicin concentrations above the minimum inhibitory concentration were recorded in the systemic circulation 45 minutes after injury and persisted for the duration of the experiment . CONCLUSIONS: Fibrinogen-impregnated collagen is an effective haemostatic agent in splenic trauma that may be of use for both the local and systemic delivery of antibiotics.

J Gastroenterol, 1999 Jun, 34(3), 395 - 9
A patient who survived total colonic type ulcerative colitis complicated by toxic megacolon, disseminated intravascular coagulation, methicillin-resistant Staphylococcus aureus infection and bilateral femoral phlebothrombosis; Arai H et al.; We report a patient who survived total colonic type ulcerative colitis (UC) complicated by toxic megacolon (TM), disseminated intravascular coagulation (DIC), methicillin-resistant Staphylococcus aureus infection, and phlebothrombosis . A 69-year-old man was treated for about 4 months under the diagnosis of ischemic colitis at another hospital, and was transferred to our hospital . Based on endoscopic and pathological findings, we strongly suspected UC, and administered salazosulfapyridine and methylprednisolone, but TM and DIC developed, necessitating urgent subtotal colectomy . Despite his elderly age and the severe complications, he recovered and was discharged from our hospital about 4 months after admission . The mortality rate of UC complicated by TM and DIC in elderly patients is high, necessitating rapid initiation of high-dose steroid administration or surgical treatment.

J Appl Microbiol, 1999 Jul, 87(1), 182 - 6
The use of enterocin CCM 4231 in soy milk to control the growth of Listeria monocytogenes and Staphylococcus aureus; Laukova A et al.; The inhibitory effect of enterocin CCM 4231 (concentration 3200 AU ml-1) was used to control the growth of Listeria monocytogenes Ohio and Staphylococcus aureus in soy milk . The growth and bacteriocin (enterocin) production of producer strain CCM 4231 in soy milk was also checked . Bacteriocin production by CCM 4231 strain in soy milk was first detected after 2 h from the beginning of cultivation (100 AU ml-1) . The stationary phase for CCM 4231 was reached after 6 h reaching 10.38 cfu ml-1 (log10) with a slight increase up to 24 h (10.43 cfu ml-1, log10), and the maximum bacteriocin production in soy milk (200 AU ml-1) was noted after 8 h of the beginning of cultivation with stability up to 24 h . The addition of enterocin CCM 4231 at 3200 AU ml-1 to a growing indicator strain, L . monocytogenes Ohio, in soy milk resulted in inhibition for 24 h . The high inhibitory effect of enterocin was found after 1 h and 2 h of its addition (in 5 h-6 h of cultivation), the difference between the experimental and the control samples (ES, CS) being 4.96 log cycles at 5 h and 5.15 log cycles at 6 h . Staphylococcus aureus was not fully inhibited, although a difference of 3.55 log cycles was found when ES and CS were compared at the end of cultivation (24 h) . The pH was not influenced by enterocin addition . The inhibitory effect of enterocin CCM 4231 against L . monocytogenes Ohio in soy milk was probably bacteriocidal; while Staph . aureus was influenced bacteriostatically . In general, the observed inhibitory activity confirmed the possibility for further application of bacteriocins in food environments as the protective agents . Of course, legislation problems must be solved.

J Ethnopharmacol, 1999 Jul, 66(1), 75 - 8
Mode of action of Buddleja cordata verbascoside against Staphylococcus aureus; Avila JG et al.; We evaluate the mode of action of verbascoside obtained from Buddleja cordata against Staphylococcus aureus by killing kinetics and incorporation of precursors methods . Verbascoside induced lethal effect on S . aureus, by affecting protein synthesis and inhibiting leucine incorporation.

Infect Control Hosp Epidemiol, 1999 Jul, 20(7), 478 - 86
Methicillin-resistant Staphylococcus aureus in French hospitals: A 2-month survey in 43 hospitals, 1995 . The Hôpital Propre II Study Group.
Screening high-risk patients for methicillin-resistant Staphylococcus aureus on admission to the hospital: is it cost effective?
Department of Microbiology, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, Ontario, CanadaOBJECTIVES: To determine the cost-effectiveness of a policy of screening high-risk patients for methicillin-resistant Staphylococcus aureus (MRSA) colonization on admission to hospital . SETTING: 980-bed university-affiliated tertiary-care hospital . PATIENTS: Between June 1996 and May 1997, patients directly transferred from another hospital or nursing home, or who had been hospitalized in the previous 3 months, were screened for MRSA within 72 hours of hospital admission . DESIGN: Nasal, perineal, and wound swabs were obtained for MRSA screening using standard laboratory methods . Laboratory and nursing costs associated with screening patients for MRSA on admission to hospital were calculated . The costs associated with the implementation of recommended infection control measures for patients with MRSA also were determined . RESULTS: 3,673 specimens were obtained from 1,743 patients . MRSA was found on admission in 23 patients (1.3%), representing 36% of the 64 patients with MRSA identified in the hospital during the year . MRSA-colonized patients were more likely to have been transferred from a nursing home (odds ratio {OR}, 6.4; P =.04) or to have had a previous history of MRSA colonization (OR, 13.1; P =.05) . Laboratory and nursing costs were found to be $8.34 per specimen, for a total cost of $30,632 during the year . The average cost of implementing recommended infection control measures for patients colonized with MRSA was approximately $5,235 per patient . CONCLUSION: If early identification of MRSA in colonized patients prevents nosocomial transmission of the organism to as few as six new patients, the screening program would save money.

Z Naturforsch {C}, 1999 May-Jun, 54(5-6), 406 - 16
Phytochemical, morphological, and biological investigations of propolis from Central Chile; Valcic S et al.; Propolis from central Chile was investigated for its plant origin by microscopical analysis of pollen grains and leaf fragments found in the sample . The pollen grains that appear with significant higher frequency in the sample corresponded to four native and two introduced species, whereas leaf fragments corresponded to four native species . Seventeen phenolic compounds that belong to the phenylpropane, benzaldehyde, dihydrobenzofuran, or benzopyran classes, were isolated from an organic extract that was found to have a moderate growth inhibitory activity against Mycobacterium avium, M . tuberculosis, and two strains of Staphylococcus aureus . The components responsible for activity were determined.

Rev Esp Med Nucl, 1999 Jun, 18(3), 209 - 13
{Septic paniculitis and 67Ga scintigraphy}; Gonzalez-Gaggero Prieto-Carre et al.; A 50 year-old patient presenting septicemia, septic panniculitis from Staphylococcus aureus and skin lesions on the buttocks, thighs and left arm was referred to the Nuclear Medicine Service, with a suspected underlying osseus problem . A whole body scan with 67Ga revealed generalized disease of the soft tissues with no bone involvement . Gallium was used for the monitor of the evolution of the lesions, since this is a good indicator of the treatment effectiveness . In this case, the use of nuclear techniques was fundamental for diagnosing the spread and evolution of the lesions until they were cured (cured being considered as when there is no gallium uptake by the lesions, months prior to this stage).

Proc Natl Acad Sci U S A, 1999 Aug 3, 96(16), 9351 - 6
The essential Staphylococcus aureus gene fmhB is involved in the first step of peptidoglycan pentaglycine interpeptide formation; Rohrer S et al.; The factor catalyzing the first step in the synthesis of the characteristic pentaglycine interpeptide in Staphylococcus aureus peptidoglycan was found to be encoded by the essential gene fmhB . We have analyzed murein composition and structure synthesized when fmhB expression is reduced . The endogenous fmhB promoter was substituted with the xylose regulon from Staphylococcus xylosus, which allowed glucose-controlled repression of fmhB transcription . Repression of fmhB reduced growth and triggered a drastic accumulation of uncrosslinked, unmodified muropeptide monomer precursors at the expense of the oligomeric fraction, leading to a substantial decrease in overall peptidoglycan crosslinking . The composition of the predominant muropeptide was confirmed by MS to be N-acetylglucosamine-(beta-1,4)-N-acetylmuramic acid(-L-Ala-D-iGln-L-Lys-D-Ala-D-Ala), proving that FmhB is involved in the attachment of the first glycine to the pentaglycine interpeptide . This interpeptide plays an important role in crosslinking and stability of the S . aureus cell wall, acts as an anchor for cell wall-associated proteins, determinants of pathogenicity, and is essential for the expression of methicillin resistance . Any shortening of the pentaglycine side chain reduces or even abolishes methicillin resistance, as occurred with fmhB repression . Because of its key role FmhB is a potential target for novel antibacterial agents that could control the threat of emerging multiresistant S . aureus.

S D J Med, 1999 Jul, 52(7), 241 - 7
Reduction in methicillin-resistant Staphylococcus aureus infection rate in a nursing home by aggressive containment strategies; Jaqua-Stewart MJ et al.; For the month of October, 1993, the Methicillin-Resistant Staphylococcus aureus nosocomial infection rate in our 42-bed Extended Care Unit/Nursing Home was 33% (8.5% for the 1993 year) . Our facility was committed to decrease colonization and infection rates and to prevent the introduction of additional colonized patients into the closed environment . Methicillin-Resistant Staphylococcus aureus containment practices were instituted and consisted of total population and staff surveillance, aggressive containment measures and followed by maintenance containment protocols . The aggressive plan included contact isolation, baths with chlorhexagluconate, treatment of nasal carriers with mupiricin and treatment of both colonized and infected patients . This was followed by maintenance measures of screening new admissions for Methicillin-Resistant Staphylococcus aureus with contact isolation and treatment for positive as described during the aggressive phase . Total population surveillance was repeated after one year . Results showed that no employees were colonized with Methicillin-Resistant Staphylococcus aureus . The initial colonization rate in residents/patients was 52% . After one year the colonization rate dropped to 2% and the infection rate to 1.4% . Molecular epidemiology demonstrated that there was limited acquisition of new strains of Methicillin-Resistant Staphylococcus aureus within the Extended Care Unit . The process was shown to be cost effective . Aggressive containment practices applied to a nursing home with a high Methicillin-Resistant Staphylococcus aureus infection rate not only reduced rates of colonization, but also markedly reduced infections . This reduction was maintained over time.

Antimicrob Agents Chemother, 1999 Aug, 43(8), 1932 - 4
Bactericidal activity of vancomycin in cerebrospinal fluid; Nagl M et al.; Intraventricular application of vancomycin is an effective therapeutic regimen for the treatment of shunt-associated staphylococcal ventriculitis . We examined the in vitro activity of vancomycin at high concentrations against Staphylococcus aureus ATCC 25923 and Staphylococcus epidermidis ATCC 12228 in human cerebrospinal fluid samples . Time-kill curves revealed equal efficacies for concentrations of 10, 100, and 300 microg/ml, and incubation times of 24 to 48 h were needed to achieve a 3 log(10) reduction of viable bacteria . A concentration of 5 microg/ml showed a slightly lower activity, but this difference was not significant . In an infant who was successfully treated for shunt-associated ventriculitis due to S . epidermidis by once-daily local administration of vancomycin (3 mg for 2 days and 5 mg for 4 days {0 . 5 to 0.8 mg/kg of body weight}) the in vivo kill kinetics were similar to those for the in vitro results . These results support time-dose regimens that provide trough vancomycin levels of 5 to 10 microg/ml.

Antimicrob Agents Chemother, 1999 Aug, 43(8), 1914 - 8
Analysis of vancomycin population susceptibility profiles, killing activity, and postantibiotic effect against vancomycin-intermediate Staphylococcus aureus; Aeschlimann JR et al.; Methicillin-resistant Staphylococcus aureus strains with decreased vancomycin susceptibility have been isolated from patients in the United States and Japan . The impact of decreased vancomycin susceptibility on the drug's pharmacodynamic parameters has not been addressed . We studied the activity of vancomycin against three clinical strains of vancomycin intermediate-susceptible Staphylococcus aureus (VISA) under high- and low-inoculum conditions, with stationary- and logarithmic-growth-phase kill curves, and in postantibiotic effect (PAE) experiments . We also investigated the stability of the decreased vancomycin susceptibility by using population susceptibility profiles . The respective vancomycin microdilution MICs and MBCs for VISA strains HIP5836, 14379, and Mu50 were 8 and 8, 8 and 8, and 8 and 16 microg/ml . HIP5836 had the most homogeneous elevation of vancomycin MICs, because the MIC for nearly all bacteria in the inoculum was 8 microg/ml . The population MICs (defined as the lowest vancomycin concentration inhibiting 99 . 9% of growth) for the first serial passages of HIP5836, Mu50, and 14379 were 8, 4, and 2 microg/ml, respectively . After 10 passages, they decreased to 4, 2, and 1 microg/ml, respectively . The Mu50 population MIC increased to 12 microg/ml after five serial passages on vancomycin agar . In the low- and high-inoculum kill curves, time to 99.9% killing was significantly (P < 0.05) longer for both Mu50 and HIP5836 than that for 14379 and a control strain . However, colony counts at 24 h were similar to those of the vancomycin-sensitive strain for all VISA strains . The PAE (at 4x MIC) ranged from 1.3 h for 14379 to 2.0 h for HIP5836 and was similar to or greater than the PAE against the vancomycin-sensitive strain . In conclusion, we found that the decreased vancomycin susceptibility increased during persistent exposures to the drug and decreased upon removal of the selective pressure . The decreased vancomycin susceptibility decreased the rate of vancomycin killing, but did not affect the extent of killing or the PAE.

Antimicrob Agents Chemother, 1999 Aug, 43(8), 1845 - 55
Activities of trovafloxacin compared with those of other fluoroquinolones against purified topoisomerases and gyrA and grlA mutants of Staphylococcus aureus; Gootz TD et al.; Frequencies of mutation to resistance with trovafloxacin and four other quinolones were determined with quinolone-susceptible Staphylococcus aureus RN4220 by a direct plating method . First-step mutants were selected less frequently with trovafloxacin (1.1 x 10(-10) at 2 to 4x the MIC) than with levofloxacin or ciprofloxacin (3.0 x 10(-7) to 3.0 x 10(-8) at 2 to 4x the MIC) . Mutants with a change in GrlA (Ser80-->Phe or Tyr) were most commonly selected with trovafloxacin, ciprofloxacin, levofloxacin, or pefloxacin . First-step mutants were difficult to select with sparfloxacin; however, second-step mutants with mutations in gyrA were easily selected when a preexisting mutation in grlA was present . Against 29 S . aureus clinical isolates with known mutations in gyrA and/or grlA, trovafloxacin was the most active quinolone tested (MIC at which 50% of isolates are inhibited {MIC(50)} and MIC(90), 1 and 4 microg/ml, respectively); in comparison, MIC(50)s and MIC(90)s were 32 and 128, 16 and 32, 8 and 32, and 128 and 256 microg/ml for ciprofloxacin, sparfloxacin, levofloxacin, and pefloxacin, respectively . Strains with a mutation in grlA only were generally susceptible to all of the quinolones tested . For mutants with changes in both grlA and gyrA MICs were higher and were generally above the susceptibility breakpoint for ciprofloxacin, sparfloxacin, levofloxacin, and pefloxacin . Addition of reserpine (20 microg/ml) lowered the MICs only of ciprofloxacin fourfold or more for 18 of 29 clinical strains . Topoisomerase IV and DNA gyrase genes were cloned from S . aureus RN4220 and from two mutants with changes in GrlA (Ser80-->Phe and Glu84-->Lys) . The enzymes were overexpressed in Escherichia coli GI724, purified, and used in DNA catalytic and cleavage assays that measured the relative potency of each quinolone . Trovafloxacin was at least five times more potent than ciprofloxacin, sparfloxacin, levofloxacin, or pefloxacin in stimulating topoisomerase IV-mediated DNA cleavage . While all of the quinolones were less potent in cleavage assays with the altered topoisomerase IV, trovafloxacin retained its greater potency relative to those of the other quinolones tested . The greater intrinsic potency of trovafloxacin against the lethal topoisomerase IV target in S . aureus contributes to its improved potency against clinical strains of S . aureus that are resistant to other quinolones.

Int J Pediatr Otorhinolaryngol, 1999 Jun 15, 49(1), 81 - 6
Orbital abscess due to acute ethmoiditis in a neonate; Reddy SC et al.; Orbital complications due to ethmoiditis are not uncommon in children . However, they are very rare in infants . A case of orbital abscess due to acute ethmoiditis in a 10 days old boy is reported . Causative microorganisms isolated from the operated specimen were Staphylococcus aureus and aspergillosis . Successful outcome was achieved following antimicrobial therapy, external ethmoidectomy, and surgical drainage of the abscess . The aetiopathogenesis and management of this clinical entity is discussed, with a brief review of the literature.

Hautarzt, 1999 Jun, 50(6), 418 - 21
{Treatment of acute exacerbated atopic eczema with emollient-antiseptic preparations using the "wet wrap" ("wet pajama") technique}; Abeck D et al.; Six patients (3 children and 3 adults) with acute exacerbated atopic eczema were treated with basic emollients in combination with chlorhexidine-soaked dressings over a period of three days using the "wet-pyjama" technique . Improvement of eczema was documented with the severity score "Scoring of Atopic Dermatitis" (SCORAD); most pronounced changes were found for the subjective parameters itch and sleep loss . Paralleling skin improvement a reduction of Staphylococcus aureus colonisation was noted . Improvement of skin changes lasted beyond the active treatment period . Wet-wrap dressings are an effective treatment modality for atopic eczema without use of corticosteroids and can be used easily on an outpatient basis when manufactured dressings are used.

Antonie Van Leeuwenhoek, 1999 Apr, 75(3), 233 - 43
Characterization of a novel bacteriocin-encoding plasmid found in clinical isolates of Staphylococcus aureus; Gamon MR et al.; Plasmids specifying bacteriocin production and immunity to its action were found in three clinical isolates of Staphylococcus aureus obtained in different hospitals located in Rio de Janeiro . These plasmids (pRJ28, pRJ29 and pRJ30) of 8.0 kb were found to generate identical restriction fragment patterns upon digestion with several enzymes, although the range of strains susceptible to the respective bacteriocin varied among the producer strains, when different Gram-positive bacteria were used as indicators, pRJ29 was then chosen for further characterization in order to compare it with pRJ6 and pRJ9, two small bacteriocin-encoding plasmids previously described in strains isolated from food . pRJ29 was found to code for a bacteriocin with chemical properties (sensitivity to proteases, heat resistance, activity under anaerobiosis, and estimated molecular weight) similar to those of pRJ6-encoded bacteriocin, conferring cross-immunity to it . However, its restriction map differed from those of pRJ6 and pRJ9 . These studies together with hybridization, incompatibility, and mobilization analyses using a derivative of pRJ29 tagged with Tn917-lac suggest that pRJ29 is a mosaic composed of genetic determinants found on pRJ6 and pRJ9, and that IS257 was not involved in the recombination events which gave rise to pRJ29.

Antonie Van Leeuwenhoek, 1999 Apr, 75(3), 183 - 9
Osmoprotective activity, urea protection, and accumulation of hydrophilic betaines in Escherichia coli and Staphylococcus aureus; Peddie BA et al.; The hydrophilic betaines, deanol betaine, triethanol betaine, diethanolthetin and methylethanolthetin, and also thioxanium betaine and citrulline betaine, were accumulated by Escherichia coli . All betaines tested had significant osmoprotective activity for E . coli and, with the exception of citrulline betaine and diethanolthetin, also demonstrated urea protection . Staphylococcus aureus accumulated only methylethanolthetin, deanol betaine and thioxanium betaine: the first two had an osmoprotective effect but conferred no urea protection . Diethanolthetin and thioxanium betaine significantly decreased urea tolerance for S . aureus.

Science, 1999 Jul 30, 285(5428), 760 - 3
Staphylococcus aureus sortase, an enzyme that anchors surface proteins to the cell wall; Mazmanian SK et al.; Surface proteins of Gram-positive bacteria are linked to the bacterial cell wall by a mechanism that involves cleavage of a conserved Leu-Pro-X-Thr-Gly (LPXTG) motif and that occurs during assembly of the peptidoglycan cell wall . A Staphylococcus aureus mutant defective in the anchoring of surface proteins was isolated and shown to carry a mutation in the srtA gene . Overexpression of srtA increased the rate of surface protein anchoring, and homologs of srtA were found in other pathogenic Gram-positive bacteria . The protein specified by srtA, sortase, may be a useful target for the development of new antimicrobial drugs.

Vet Surg, 1999 Jul-Aug, 28(4), 233 - 41
Biodegradable drug delivery systems for gentamicin release and treatment of synovial membrane infection; Cook VL et al.; OBJECTIVE: This study investigated two biodegradable drug delivery systems (BDDS) for elution of gentamicin and elimination of synovial membrane infection . STUDY DESIGN: The effect of BDDS on control and infected synovial explants was determined . ANIMALS OR SAMPLE POPULATION: Synovial explants from four adult equine cadavers . METHODS: First, BDDS were placed in phosphate buffered saline for 14 days . Eluent was tested for gentamicin concentration (G) and bioactivity . Second, synovial explants were divided into four groups (n = 14/group): Group 1 (control); Group 2 (infected control) 405 cfu Staphylococcus aureus added at 6 hours; Group 3 (antibiotic BDDS {Ab-BDDS}) Ab-BDDS added at 24 hours; Group 4 (infected Ab-BDDS) 405 cfu S . aureus added at 6 hours, Ab-BDDS added at 24 hours . Both types of Ab-BDDS were used (n = 7/type/group) . Explants were incubated in standard medium for 4 days . Medium was cultured and analyzed for (G) and hyaluronic acid concentration (HA) . Explants were analyzed for viability and morphologic changes . RESULTS: The Ab-BDDS released >500 microg/mL of active gentamicin for 10 days . In Group 3, infection was eliminated within 24 hours, but histologic scores did not return to normal . Viability was significantly reduced by infection, but if eliminated, viability tended to return to normal . In Group 3, the Ab-BDDS had no significant effect on viability or (HA) . Histopathologic scores were significantly higher for infected synovium . Infection, even if treated, significantly reduced (HA) . CONCLUSIONS: Both Ab-BDDS eliminated infection within 24 hours . However, synovial morphology, viability and function did not return to normal . CLINICAL RELEVANCE: The Ab-BDDS may be useful for treatment of synovial membrane infection.

Kansenshogaku Zasshi, 1999 Jun, 73(6), 570 - 7
{Clinical analysis of the prognosis of severe pneumonia requiring mechanical ventilation}; Kobashi Y et al.; To determine which factors are important in predicting the outcome of patients with severe pneumonia requiring mechanical ventilation, we compared 43 surviving pneumonic patients with 37 non-surviving pneumonic patients . The following results were obtained . The following characteristics were noted in the non-surviving patients as compared with surviving patients; 1 . a worsening of performance status in the background, 2 . presence of physical signs such as hypotension and trachycardia, 3 . abnormal laboratory data such as leukocytosis, lymphocytopenia, hypoalbuminemia, hepatorenal dysfunction and metabolic acidosis, 4 . presence of massive pulmonary infiltrations on chest roentgenograms, 5 . a prevalence of resistant microorganisms for many antibiotics such as MRSA (Methicillin resistant Staphylococcus aureus) . These results suggest that the most important factor affecting the prognosis of patients with severe pneumonia requiring mechanical ventilation may by the condition of the host and of the microorganisms rather than antibiotic treatment.

J Am Dent Assoc, 1999 Jul, 130(7), 1086 - 92
Odontogenic sinusitis causing orbital cellulitis; Mehra P et al.; BACKGROUND: Odontogenic sinusitis is a well-recognized condition that usually is responsive to standard medical and surgical treatment . Current antibiotic therapy recommendations are directed against the usual odontogenic and sinus flora . CASE DESCRIPTION: The authors present a case of a patient with acute sinusitis initiated by a complicated tooth extraction that did not yield readily to standard treatment . The case was complicated by orbital extension of the sinusitis . The authors isolated methicillin-resistant Staphylococcus aureus, or MRSA, species from the affected sinus that usually is not encountered in uncomplicated acute nonnosocomial or odontogenic sinusitis . CLINICAL IMPLICATIONS: Though such forms of resistant microbial flora as MRSA are rare, they may be seen in patients who have a history of intravenous, or i.v., drug use and in immunocompromised patients . Management of patients with orbital extension of sinusitis requires hospitalization and i.v . antibiotic treatment.

J Biomed Mater Res, 1999, 48(4), 578 - 90
Carboxymethyl benzylamide sulfonate dextrans (CMDBS), a family of biospecific polymers endowed with numerous biological properties: a review; Logeart-Avramoglou D et al.; The functionalized dextrans termed carboxymethyl benzylamide sulfonate dextran (CMDBS) represent a family encompassing a wide range of polymers . These soluble macromolecular compounds, which are substituted with specific chemical functional groups, are designed to interact with living systems . By analogy with glycosaminoglycan heparin, a natural highly charged anionic polysaccharide that exerts a variety of biological effects, we postulated that CMDBS compounds also possess binding sites capable of specific interactions with biological constituents, depending on the overall composition of the polymer . The synthesis and heparin-like properties of these CMDBS have been extensively investigated . Thus, it appears that dextran derivatives can mimic the action of heparin in regard to its interactions with antithrombin and serine proteases involved in blood coagulation . Other derivatives interact with various components of the immune system or with adhesive proteins such as fibronectin in modulating the proliferation of Staphylococcus aureus . Because they are able to stimulate wound healing in various in vivo models, these polysaccharides may also constitute a family of tissue repair agents because of their protecting and potentiating effects with heparin binding growth factors . Moreover, dextran derivatives in contact with cells such as endothelial cells, smooth muscle cells, or tumoral cells can affect both cell proliferation and metabolism . It appears that these bioactive polymers are also efficient tools to investigate the precise mechanism of action of individual biological activities by contrasting their mode of action to that of heparin . In addition to their numerous biological properties and biospecificity, functionalized dextrans are relatively simple to manufacture and exempt of donor contaminant, which make them attractive in a variety of clinical applications .

Eur J Clin Microbiol Infect Dis, 1999 May, 18(5), 335 - 40
Epidemiological analysis of methicillin-resistant Staphylococcus aureus in a Zagreb Trauma Hospital using a randomly amplified polymorphic DNA-typing method; Tambic A et al.; During a 1-month period in 1996, all inpatients and staff in the Zagreb Trauma Hospital were screened for methicillin-resistant Staphylococcus aureus (MRSA) carriage in order to control MRSA spread within the hospital . During the study period, 663 patients were admitted to the hospital, and screening prior to discharge revealed that 42 were colonised or infected with MRSA . Twenty-three (55%) of these would not have been detected if active screening had not been performed . Amongst 205 staff members, MRSA carriage was only found in one (0.5%) nurse . The prevalence and incidence of MRSA carriage varied significantly amongst the wards and was related to the length of hospital stay . One-third of the patients colonised or infected with MRSA had a history of previous admission to another hospital, and one-third were transferred to another institution after discharge . Thirty-nine of 42 MRSA isolates shared the same antibiotic sensitivity pattern, suggesting endemic spread of MRSA . However, randomly amplified polymorphic DNA molecular typing revealed four profiles, the most common involving 15 of 36 tested strains . There was no obvious clustering of epidemiological types by ward, except for the appearance of a single type on the burns unit, and it was likely that different strains had been introduced into the hospital by patient transfers from elsewhere . The results of this study indicate that a substantial proportion of MRSA carriers escape infection control measures if active screening is not performed . Based on the results of this study, steps have been taken to improve interhospital communication about the transfer of patients colonised with MRSA . Randomly amplified polymorphic DNA typing proved to be a useful aid to epidemiological investigations of MRSA.

Indian J Pathol Microbiol, 1999 Jan, 42(1), 101 - 5
Phlegmonous inflammation of gastrointestinal tract autopsy study of three cases; Kakkar N et al.; Three cases of Phlegmonous inflammation of gastrointestinal tract detected at necropsy are described . Predisposing factors were seen in all three cases . These were chronic alcoholism with submissive hepatic necrosis (HbsAg and HbcAg positive) in Case 1, Indian Childhood cirrhosis in Case 2 and acute on chronic Budd Chiari syndrome in Case 3 . In case 1 and 3 the inflammation was limited to the large intestine where as in Case 2 it was seen both in the stomach and large intestine . In two of the three cases blood culture grew Staphylococcus aureus (Case 1) and gram negative organisms (Case 2).

J Bacteriol, 1999 Aug, 181(15), 4452 - 60
Evidence for a holin-like protein gene fully embedded out of frame in the endolysin gene of Staphylococcus aureus bacteriophage 187; Loessner MJ et al.; We have cloned, sequenced, and characterized the genes encoding the lytic system of the unique Staphylococcus aureus phage 187 . The endolysin gene ply187 encodes a large cell wall-lytic enzyme (71.6 kDa) . The catalytic site, responsible for the hydrolysis of staphylococcal peptidoglycan, was mapped to the N-terminal domain of the protein by the expression of defined ply187 domains . This enzymatically active N terminus showed convincing amino acid sequence homology to an N-acetylmuramoyl-L-alanine amidase, whereas the C-terminal part, whose function is unknown, revealed striking relatedness to major staphylococcal autolysins . An additional reading frame was identified entirely embedded out of frame (+1) within the 5' region of ply187 and was shown to encode a small, hydrophobic protein of holin-like function . The hol187 gene features a dual-start motif, possibly enabling the synthesis of two products of different lengths (57 and 55 amino acids, respectively) . Overproduction of Hol187 in Escherichia coli resulted in growth retardation, leakiness of the cytoplasmic membrane, and loss of de novo ATP synthesis . Compared to other holins identified to date, Hol187 completely lacks the highly charged C terminus . The secondary structure of the polypeptide is predicted to consist of two small, antiparallel, hydrophobic, transmembrane helices . These are supposed to be essential for integration into the membrane, since site-specific introduction of negatively charged amino acids into the first transmembrane domain (V7D G8D) completely abolished the function of the Hol187 polypeptide . With antibodies raised against a synthetic 18-mer peptide representing a central part of the protein, it was possible to detect Hol187 in the cytoplasmic membrane of phage-infected S . aureus cells . An important indication that the protein actually functions as a holin in vivo was that the gene (but not the V7D G8D mutation) was able to complement a phage lambda Sam mutation in a nonsuppressing E . coli HB101 background . Plaque formation by lambdagt11::hol187 indicated that both phage genes have analogous functions . The data presented here indicate that a putative holin is encoded on a different reading frame within the enzymatically active domain of ply187 and that the holin is synthesized during the late stage of phage infection and found in the cytoplasmic membrane, where it causes membrane lesions which are thought to enable access of Ply187 to the peptidoglycan of phage-infected Staphylococcus cells.

Blood, 1999 Aug 1, 94(3), 1003 - 11
The interleukin-12-mediated pathway of immune events is dysfunctional in human immunodeficiency virus-infected individuals; Marshall JD et al.; Interleukin-12 (IL-12) is a potentially critical factor in the immune response against human immunodeficiency virus (HIV) because it is important for regulating proliferation and interferon-gamma (IFN-gamma) production by T cells and natural killer (NK) cells, antigen presentation and accessory cell function by macrophages and dendritic cells, and cytolytic activities of cytotoxic T-lymphocyte cells and NK cells, which are all functions known to be dysfunctional in patients with acquired immune deficiency syndrome . Peripheral blood mononuclear cells (PBMC) from HIV-infected patients have been previously shown to be deficient in the ability to produce IL-12 in response to the bacterial pathogen Staphylococcus aureus Cowan . In this study, impaired IL-12 production in cells from PBMC of HIV-infected patients compared with healthy donors was observed across a broad panel of stimuli derived from infectious pathogens with or without priming with cytokines such as IFN-gamma and IL-4, which amplify the IL-12 induction signal . Analysis of p40 and p35 mRNA accumulation showed that reductions in both subunits contribute to the lower IL-12 secretion of cells from HIV-infected individuals . PBMC from HIV-infected donors also failed to upregulate the IL-12 receptor beta2 chain (IL-12Rbeta2) in response to mitogenic stimuli . The expression of the IL-12Rbeta2 gene could, however, be restored by in vitro exposure to rIL-12 . Thus, it is possible that a primary IL-12 defect may lead to secondary deficiencies in expression of the genes for IL-12Rbeta2 and IFN-gamma, thus amplifying immune deficiency during HIV infection.

J Food Prot, 1999 Apr, 62(4), 356 - 62
Modeling the aerobic growth and decline of Staphylococcus aureus as affected by pH and potassium sorbate concentration; Giannuzzi L et al.; The effects of pH (5.0, 5.2, 5.4, 5.6, and 5,8) and concentration of potassium sorbate (10.0 and 16.6 mM) at two water activity values (0.90 and 0.92) on the aerobic growth and decline of Staphylococcus aureus ATCC 6538P, 196-E, and FDA-C243 were studied using brain-heart infusion broth . The inoculum was approximately 4 to 5 log CFU/ml, and the incubation temperature was 30 degrees C . Samples were periodically enumerated on tryptic soy agar . The Gompertz model was used to obtain microbial growth parameters, specific growth rate was obtained as a derived parameter, and the inhibition index was calculated . A linear model was fitted in cases of bacteriostatic or bactericidal action of the treatment . The ATCC 6538P strain showed the highest resistance in the range of tested conditions . Microbial behavior was modeled considering the main controlling factors, and a response surface methodology was used to determine the effects of undissociated acid concentration and pH . These results can be used to establish treatment conditions for microorganism growth or inhibition.

Auris Nasus Larynx, 1999 Jul, 26(3), 287 - 91
Malondialdehyde levels and superoxide dismutase activity in experimental maxillary sinusitis; Doner F et al.; OBJECTIVE: Acute maxillary sinusitis is one of the most common diseases in human . Reactive oxygen metabolites (ROMs) produced also physiologically in the body, are normally neutralised by antioxidative enzymes such as superoxide dismutase (SOD) . Infection is one of the causes of increased ROMs production . The most important mechanism of tissue damage produced by ROMs is the peroxidation of lipids found in cell membranes and it may be estimated by malondialdehyde (MDA) levels . The purpose of this study, is to investigate tissue damage caused by ROMs in maxillary sinusitis in 24 rabbits . METHODS: Experimental sinusitis was induced by blocking the right nose and inoculating Staphylococcus aureus into the right maxillary sinuses . Left maxillary sinuses were the control group . Animals were divided into three groups and killed at 3, 5 and 7 days . Mucosas of each maxillary sinus were examined histopathologically and MDA levels were determined . Blood samples were obtained preoperatively (control blood) and on killing days (experimental blood) . Serum MDA levels and erythrocyte SOD activities were determined . RESULTS: All the infected sinuses displayed signs of the inflammation . MDA levels and SOD activities in the experimental blood samples were significantly higher than those of the control group (P < 0.05) . Mucosal MDA levels in the experimental group were significantly higher than the controls (P < 0.01) . CONCLUSIONS: In maxillary sinusitis caused by S . aureus an increased ROMs production was observed and it may contribute to tissue damage of sinusitis.

Vet Microbiol, 1999 Jun 30, 67(3), 195 - 202
Purification and characterization of protease produced by Staphylococcus aureus isolated from a diseased chicken; Takeuchi S et al.; A protease produced by Staphylococcus aureus, isolated from a chicken suffering from dermatitis, was purified by successive precipitation with ammonium sulfate, ion-exchange chromatography on Q-Sepharose FF, Sp-Sepharose FF and Mono-Q columns . By Mono-Q column chromatography, two proteases (protease 1 and 2) were obtained . The molecular weights of protease 1 and 2 were estimated at 23.1 and 22.7 kDa, respectively, by SDS-polyacrylamide gel electrophoresis . Their isoelectric points were 5.85 and 5.55, respectively, and they possessed antigenic similarity when examined by the immunoblotting . The N-terminal amino acid sequences of both the proteases were identical (RAQYVNQLKNFKIRETQ) . The activities of both the proteases were strongly increased by reducing agents such as L-cysteine and sodium thioglycolate . Their activity was inhibited by thiol protease inhibitors, but was not inhibited by metalloprotease or serine protease inhibitors . From the results, it seems likely that these proteases, produced by S . aureus from diseased chickens, might belong to the thiol protease group.

Int J Antimicrob Agents, 1999 Jul, 12(2), 115 - 9
A multi-centre study of nosocomial methicillin-resistant Staphylococcus aureus in Greece . Greek MRSA Study Group; Kantzanou M et al.; All 105 non-replicate consecutive Staphylococcus aureus strains isolated in 1997 from seven Greek hospitals, were found to be susceptible to vancomycin, teicoplanin and chloramphenicol, but only five (8%) were susceptible to all 16 antibiotics tested . Forty-three (41%) isolates were methicillin-resistant, 58% homogeneously (homMRSA) and 42% heterogeneously (hetMRSA) . Resistance of homMRSA strains to other antibiotics was generally high (88-100%), although only one strain was resistant to netilmicin . Resistance in hetMRSA (6-39%) or in MSSA (5-11%) was significantly lower . Consequently, the majority (76%) of homMRSA were multi-drug resistant, while the dominant phenotype of hetMRSA and MSSA was resistance to penicillin (50% and 76%, respectively) . Comparison of these strains with isolates from 1994 showed higher resistance rates to erythromycin among MSSA, to erythromycin and amikacin among hetMRSA and to rifampicin among homMRSA strains.

Planta Med, 1999 Jun, 65(5), 450 - 2
Antimicrobial activity and stability of tingenone derivatives; Sotanaphun U et al.; Quinone-methide triterpenes of the tingenone series were evaluated for their antimicrobial activity . These compounds were effective against Bacillus cereus, B . subtilis, Sarcina lutea, Staphylococcus aureus, Microsporum gypseum and a Gram-negative bacterium, Klebsiella pneumoniae . Under acidic conditions, the quinone-methide part of these compounds rearranged into the divinyl-phenolic system, and the antimicrobial activity was thus lost.

Rev Pneumol Clin, 1999 Apr, 55(2), 83 - 7
{Community-acquired pneumonia caused by Staphylococcus aureus in non-HIV infected adult patients}; Germaud P et al.; Staphylococcus aureus is the sixth frequent cause of community-acquired pneumonia . We report 19 cases of staphylococcal pneumonia in 3 women and 16 men, mean age 55 years . Predisposing factors were: age > 65 years, alcoholism, chronic bronchopulmonary disease, immunodepression, renal failure, diabetes . The portal was usually the respiratory tract . Symptom onset was progressive . Thirteen patients had signs of severe disease . Radiology showed localized excavated infiltrations in 8 cases, with a pleural reaction in 9 . Bacteriological diagnosis was made on fibroscopic brushings on pleural fluid . Blood cultures were positive in 6 of 16 cases . Meti-S S . aureus was found in 17/19 cases . Outcome was favorable in 15 patients . These often severe infections require early antibiotic therapy using beta lactams active against S . aureus, combined when necessary with another antibiotic.

Pathol Biol (Paris), 1999 May, 47(5), 501 - 7
{Comparison of different techniques for the detection of heterogeneous resistance to methicillin in Staphylococcus aureus}; May L et al.; The methods for detection of methicillin resistant S . aureus (MRSA) can fail to detect resistance because phenotypic expression is often heterogeneous (40% of strains) . Seventy four strains of S . aureus {4 methicillin susceptible strains, 10 homogeneous MRSA (Ro) and 60 heterogeneous MRSA (Rh)} were isolated from different french hospitals in Paris . These strains were tested by different methods: oxacillin screen plate with 6 micrograms/ml oxacillin and 4% NaCl, agar diffusion method with 5 micrograms oxacillin disk tested either at 30 degrees C on Mueller-Hinton medium or at 37 degrees C on Mueller-Hinton plus 5% NaCl, BBL Crystal MRSA ID system tested with two inocula (0.5 and 1 McFarland equivalent bacterial suspension) at 37 degrees C for 4 h and 5 h . Dot-blot hybridization was performed under stringent condition with the mecA probe . The accuracy of the different methods for the detection of methicillin resistance is equivalent, except for the BBL crystal system with a 0.5 McFarland inoculum wich detects the resistance with an accuracy of 86% for Ro strains and 69% for Rh strains . In other respects, there was a close correlation with the detection of the phenotypic resistance and the presence of mecA gene . So this study demonstrates that these various methods can be used for the detection of methicillin resistant S . aureus . For a rapid detection (below 5 h) the BBL crystal system with a 1 McFarland inoculum can be used; the agar diffusion method remains a good method provided some conditions (inoculum, incubation temperature, addition of salt, incubation period); the oxicillin screnn plate is a very attractive method for it is easy and reliable.

Pathol Biol (Paris), 1999 May, 47(5), 474 - 7
Epidemiological study of Staphylococcus aureus resistant to methicillin responsible for nosocomial infections in nine French hospitals; Pangon B et al.; A number of European studies found that nosocomial infections were caused by a limited number of methicillin-resistant Staphylococcus aureus (MRSA) strains . A study was undertaken to determine the number of MRSA clones responsible for nosocomial infections in France . Strains responsible for nosocomial infections meeting CDC criteria were collected one week every month from June to October 1997 in nine French hospitals . Strains that were positive by the oxacillin-resistance screening test were studied for the IS 431, femA, and mecA genes . Strain type was identified using pulsed-field gel electrophoresis of fragments produced by Smal digestion . Susceptibility to antimicrobials was evaluated based on inhibition zone diameters and minimal inhibitory concentrations determined using the agar dilution method . The 83 strains studied were distributed across four pulsotypes . Eleven resistance phenotypes were identified by ascending hierarchical classification based on inhibition zone diameters . MRSAs responsible for nosocomial infections belong to a limited number of clones that express variable levels of resistance to antimicrobials.

Pathol Biol (Paris), 1999 May, 47(5), 449 - 56
{Outbreak of methicillin-resistant Staphylococcus aureus in general hospital intensive care unit}; Kahla-Clemenceau N et al.; Mantes' hospital polyvalent intensive care unit (ICU) experienced an outbreak episode caused by methicillin resistant Staphylococcus aureus (MRSA) . Suspicion of physicians was strengthened by observing the weekly reading of multiresistant germs and the significative increase of MRSA carriers incidence rate, compared with the number of admission in the ICU: 5.5% to 11.3% . This outbreak was surprising: it happened immediately after the installation in a new hospital and the reinforcement of nosocomial infection surveillance (systematic screening of every patient admitted to the I.U.C., his isolation if he presents risk factors to multiresistant germs, increasing of handwashing stations) . The overlapping period of hospitalisation concerning the 13 patients being reported as SARM carrier, having the same antibiogram, and the epidemic curve suggested a cross contamination . The index case was a MRSA carrier the day of her admission and have had a recent hospitalisation in a high risk unit . MRSA has always been isolated in nasal swab . Six patients among the thirteen carriers developed an infection and have been treated by vancomycin: two systemic infections and four pulmonary infections . The mortality rate was 33% and only one of them seemed to be directly due to MRSA . Area samples were all negative . The clinical staff have been screened with nasal swab . We identified only one nasal MRSA carrier . The pulsed-field gel electrophoresis study showed that 9/11 which have been analysed were identical . This outbreak brought about staff, more sensibilisation to the nosocomial infection and updating of plain hygien rules leaded to its stop five months later.

Pathol Biol (Paris), 1999 May, 47(5), 445 - 8
{Inquiry into the incidence of nosocomial infections and evaluation of the transmission of methicillin-resistant Staphylococcus aureus in an orthopedic surgical unit}; Zulian C et al.; Nosocomial infections are an important cause of morbidity and mortality . Methicillin resistant Staphylococcus aureus (MRSA) is often the severe causal agent in this kind of infections . In order to evaluate risk factors for nosocomial infections and nasal MRSA carriage, an incidence study was carried out on patients hospitalized in an orthopaedic surgery department in Boucicaut Hospital (Paris) . This study was carried out over a five month period . Data of all the patients who stayed more than two days in the unit were collected in medical and nursing records . Nasal swab specimens were taken at the admission of each patient included in order to screen nasal MRSA carriers . Statistical analysis were performed using Epi Info software version 6.0 . A total of 451 patients were included in the study . Nosocomial infections incidence rate was 11.5% . Risk factor significantly associated with nosocomial infection was high wound containation classes III and IV (Altemeier) . Incidence rate of MRSA carriage was 3.1% . A previous hospitalization in a general hospital 6 months before an admission at Boucicaut Hospital was the only risk factor identified . According to this, these patients, when they are admitted, are proposed to be preventely isolated awaiting their microbiological results.

Infect Immun, 1999 Aug, 67(8), 4216 - 22
Heat-shocked monocytes are resistant to Staphylococcus aureus-induced apoptotic DNA fragmentation due to expression of HSP72; Guzik K et al.; Human peripheral blood monocytes became apoptotic following phagocytosis of Staphylococcus aureus . The consequences of heat stress for monocytes were studied with regard to the effect on S . aureus-induced apoptosis . Exposure of monocytes to 41.5 degrees C for 1 h resulted in HSP72 expression and had no influence on phagocytosis of bacteria; moreover, phagocytosis of S . aureus immediately or shortly after heat shock had no effect on the S . aureus-induced monocyte apoptosis, as evidenced by DNA fragmentation assay . In contrast, cells which recovered from heat shock for 18 to 24 h, although active as phagocytes, were resistant to the S . aureus-induced apoptosis . The observed protective effect was related to the induction of HSP72, since blocking of HSP72 synthesis by an antisense oligomer abolished the protective effect of heat shock on bacterium-induced monocyte apoptosis.

Infect Immun, 1999 Aug, 67(8), 4014 - 8
New exfoliative toxin produced by a plasmid-carrying strain of Staphylococcus hyicus; Sato H et al.; A new serotype of Staphylococcus hyicus exfoliative toxin (SHET), serotype B, was isolated from the culture filtrate of a plasmid-carrying strain of S . hyicus . The new SHET was purified by precipitation with 70% saturated ammonium sulfate, gel filtration on a Sephadex G-75 column, column chromatography on DEAE-Cellulofine A-500, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) . The new SHET caused exfoliation of the epidermis as determined by the so-called Nikolsky sign when inoculated into 1-day-old chickens . The new SHET was serologically different from Staphylococcus aureus exfoliative toxins (ETs) (ETA, ETB, and ETC) and from the SHET from the plasmidless strain but showed the same molecular weight as the other serotypes of toxins on SDS-PAGE . It was thermolabile and lost its toxicity after being heated at 60 degrees C for 30 min . We propose that the new SHET be designated SHETB and that the SHET produced by the plasmidless strain be designated SHETA.

Infect Immun, 1999 Aug, 67(8), 3952 - 9
Functional analysis of the Staphylococcus aureus collagen adhesin B domain; Snodgrass JL et al.; The Staphylococcus aureus collagen adhesin (CNA) occurs in at least four forms that differ in the number (one, two, three, or four) of B domains . The B domains contain 187 amino acids and are located between the domains that anchor CNA to the cell envelope and the ligand-binding A domain . To determine whether a B domain is required for functional expression of CNA, we cloned the 2B cna gene from S . aureus strain Phillips and then eliminated both B domains by overlapping PCR . The absence of a B domain did not affect processing of the collagen adhesin to the cell surface or the ability to bind collagen . Based on our recent demonstration that the capsule can mask CNA on the surface of S . aureus cells (A . F . Gillaspy et al., Infect . Immun . 66:3170-3178, 1998), we also investigated the possibility that multiple B domains can extend the ligand-binding A domain outward from the cell surface and thereby overcome the inhibitory effect of the capsule . Specifically, we cloned the naturally occurring 4B CNA variant from S . aureus UAMS-639 and, by successive elimination of B domains, generated 1, 2, and 3B variants that are isogenic with respect to the 4B clone . After introducing each variant into microencapsulated and heavily encapsulated strains of S . aureus and growing cells under conditions known to affect capsule production (e.g., growth on Columbia agar), we correlated capsule production with exposure of CNA on the cell surface and the ability to bind collagen . Under no circumstance was the masking effect of the capsule reduced by the presence of multiple B domains . These results indicate that the B domains do not extend the ligand-binding A domain outward in a fashion that can overcome the inhibition of collagen binding associated with capsule production.

Zentralbl Veterinarmed B, 1999 Jun, 46(5), 289 - 99
The effect of experimental infectious mastitis on leukocyte subpopulations and cytokine production in non-lactating ewes; Waller KP et al.; The interactions between leukocytes and cytokines during the acute response to intramammary infections in the dry mammary gland of sheep were studied . Dry ewes were experimentally infected in one udder half with either Staphylococcus aureus or Escherichia coli, or infused with saline as control . Udder secretion samples, blood samples and udder tissue samples were collected before and 4, 8 and 24 h after infections/infusions . Total and differential leukocyte counts were calculated in both blood and mammary secretions, and flow cytometry was used to detect the presence of CD4+, CD8+, WC1+, IL-2R+, CD18+ or L-selectin + lymphocytes, CD18+ or L-selectin + neutrophils, and CD14+ leukocytes . Moreover, the concentrations of interleukin-1 beta (IL-1 beta), interleukin-8 (IL-8) and granulocyte-macrophage colony stimulating factor (GM-CSF) in udder secretions were measured using ELISA, and RT-PCR was used to detect the presence of corresponding cytokine mRNA in udder tissue biopsies . The results suggest an association between the concentrations of IL-1 beta, IL-8 and the intensity of neutrophil infiltration of the infected gland . Immunologically relevant changes in proportions of lymphocyte subpopulations might also occur in the acute phase of the inflammatory reaction of the udder . Greater cellular and cytokine responses to E . coli infection may have contributed to the milder clinical picture and more rapid resolution of infection than that seen for S . aureus . Enhancing the production of pro-inflammatory cytokines may improve defence against bacterial mastitis.

J Dairy Sci, 1999 Jul, 82(7), 1581 - 5
Deoxyribonucleic acid fingerprinting of Staphylococcus aureus from heifer mammary secretions and from horn flies; Gillespie BE et al.; Staphylococcus aureus isolated from heifer mammary secretions, streak canals, and horn flies (Haematobia irritans) were evaluated by randomly amplified polymorphic DNA fingerprinting . The relationship between DNA fingerprint patterns of S . aureus isolated from horn flies and S . aureus isolated from heifer mammary glands was examined . Amplified DNA fragments were visualized by agarose gel electrophoresis and were analyzed by densitometry . Analysis of DNA fingerprint patterns of 56 S . aureus isolates that were obtained from heifer mammary secretions or streak canals resulted in three distinct subtypes of S . aureus . Of these, 31 isolates (55%) belonged to subtype 1, 22 isolates (39%) belonged to subtype 2, and 3 (5%) belonged to subtype 3 . Eight of 10 S . aureus isolates from horn flies belonged to subtype 1, and 2 isolates belonged to subtype 2 . Thus, all of the S . aureus isolates from horn flies had DNA fingerprint patterns identical to the majority (95%) of S . aureus isolates from heifer mammary secretions or streak canals . In addition, 10 S . aureus isolates from multiparous cows from the same herd were examined by randomly amplified polymorphic DNA . All S . aureus isolates from multiparous cows belonged to subtype 3 . Results of this study suggest that horn flies may play an important role in the transmission of S . aureus to nulligravid and primigravid heifers . Furthermore, this study demonstrates the usefulness of randomly amplified polymorphic DNA fingerprinting to distinguish between different subtypes of S . aureus and to draw epidemiological inferences from the information it provides.

Pediatr Radiol, 1999 Aug, 29(8), 617 - 23
Power Doppler evaluation of joint effusions: investigation in a rabbit model; Strouse PJ et al.; OBJECTIVE: To study the power Doppler findings of septic arthritis and noninfectious synovitis in an animal model . MATERIALS AND METHODS: The right knees of 10 rabbits were inoculated with an aqueous suspension of Staphylococcus aureus . The right knees of 5 rabbits were injected with talc suspension . The right knees of 5 rabbits were injected with saline . All 20 left knees were injected with saline . Serial power Doppler images were obtained using constant-imaging parameters . Images were reviewed by blinded observers who assessed for increased power Doppler signal . RESULTS: All 10 knees inoculated with S . aureus developed septic arthritis . Each infected rabbit knee demonstrated increased signal on power Doppler on at least one examination, ranging from 1-6 days after inoculation . Only 23 of 45 examinations of infected knees were unequivocally positive by power Doppler on examinations performed 1 to 6 days after inoculation . No knee with talc synovitis demonstrated increased power Doppler signal . No control knee demonstrated increased power Doppler signal . CONCLUSION: Increased power Doppler signal may be seen with septic arthritis; however, its intensity and timing may vary from subject to subject . A normal power Doppler examination does not exclude septic arthritis.

Vet Microbiol, 1999 Jun 15, 67(2), 127 - 41
Molecular subtyping of Staphylococcus aureus isolates from cases of bovine mastitis in Brazil; Lange C et al.; Sixty-six isolates of Staphylococcus aureus obtained from milk samples of dairy cows suffering from subclinical mastitis in southern Brazil were analysed by five different molecular typing methods . These included the analysis of plasmid profiles, the analysis of coagulase (coa) gene polymorphisms by PCR amplification of the 3' terminal region of the coa gene, the PCR-based detection of polymorphisms in the X region of the protein A gene (spa), the PCR-directed analysis of variations in the spacer region between 16S and 23S rRNA, and the comparison of pulsed-field gel electrophoretically separated genomic SmaI fragment patterns . The molecular typing methods were supplemented with the biochemical characterization of the isolates and the determination of their in-vitro susceptibility to 14 different antibiotics . All genotypic and phenotypic typing methods were analyzed for their ability to discriminate between the isolates . Macrorestriction analysis proved to be the most discriminatory single method (D = 0.96) followed by rRNA spacer typing (D = 0.85), coa PCR (D = 0.82), and spa PCR (D = 0.80).

Vet Microbiol, 1999 Jun 15, 67(2), 113 - 25
Development and evaluation of an immunomagnetic separation-ELISA for the detection of Staphylococcus aureus thermostable nuclease in composite milk; Yazdankhah SP et al.; An ELISA method based on monodisperse magnetic beads was developed for the detection of Staphylococcus aureus thermostable nuclease (TNase) in composite milk, wherein S . aureus TNase is captured by magnetic beads coated with monoclonal antibodies directed against TNase and subsequently detected by an enzyme-labelled MAb against the same antigen . Sensitivity of the test was approximately 1 ng TNase, which corresponds to the amount of TNase produced and secreted by approximately 10(5) S . aureus per ml . The Immuno Magnetic Separation (IMS)-ELISA detected TNase in samples from which no S . aureus could be demonstrated on culture . The total test time is 3 h and can be performed either on preserved or fresh milk . The method may be automated.

Vet Microbiol, 1999 Jun 15, 67(2), 77 - 89
Cell tropism of Staphylococcus aureus in bovine mammary gland cell cultures; Lammers A et al.; Staphylococcus aureus is one of the most important pathogens of the bovine mammary gland . The interaction of S . aureus with cells of the bovine mammary gland is considered to play an essential role in the pathogenesis . In this study, we identified a new target cell for S . aureus adhesion and invasion . For that purpose, cells which compose the alveoli of the mammary gland were cultured . In these cultures, two morphologically different cell types, elongated and cubic cells, were observed . Adhesion and invasion of S . aureus was studied using microscopical and microbiological methods . S . aureus adhered specifically and in large numbers (about 300 bacteria/cell) to the elongated cell type . No adhesion to the cubic cell type was observed . In addition, bacteria were also found intracellularly in the elongated cells, and enclosed in membrane vesicles . Adhesion and invasion were time dependent and reached maximum levels after 4 h . Invasion was strongly reduced by staurosporine and genistein . The newly identified target cell was further characterized.

Nervenarzt, 1999 Jun, 70(6), 547 - 51
{Juvenile dermatomyositis--acute recidivism or sepsis?}; Bahner D et al.; A 22-year-old male with juvenile dermatomyositis presented with fever up to 40 degrees C and acute pain in his right thigh accompanied by muscle weakness, a skin rash and a tender swelling . Serum aspartate aminotransferase (AST) and aldolase were mildly elevated . C-reactive protein (CRP) and fibrinogen were markedly increased . The differential white blood cell count revealed relative lymphopenia . Radiography showed diffuse calcifications particularly around the thighs and knees of both legs . Magnetic resonance imaging (MRI) demonstrated inflammatory infiltrates in the right thigh . The lesions were identified as phlegmone by immunoszintigraphy with 99mTc-labelled antigranulocyte antibodies . On the 10th day of treatment Staphylococcus aureus was cultured from blood . Patients with juvenile dermatomyositis and calcinosis may develop bacterial infections of soft tissue which sometimes mimic a disease flare . For differential diagnosis plain radiographs, CT scans and MRI are of limited value . Immunoszintigraphy is able to differentiate between infiltrates caused by granulocytes and lymphocytes.

Mol Microbiol, 1999 Jul, 33(2), 317 - 26
The Staphylococcal accessory regulator (sar) represses transcription of the Staphylococcus aureus collagen adhesin gene (cna) in an agr-independent manner; Blevins JS et al.; Comparison of Staphylococcus aureus strains carrying mutations inactivating the staphylococcal accessory regulator (sar ) and/or the accessory gene regulator (agr ) suggests that sar is the primary regulatory element controlling transcription of the collagen adhesin gene (cna ) and that the regulatory effect of sar is independent of the interaction between SarA and agr . To test this hypothesis, we cloned the regions encoding each of the overlapping sar transcripts, all of which include the sarA open reading frame (ORF), and introduced each clone into cna-positive sar and agr mutants . The introduction of each clone restored the expected sar transcripts and the temporal pattern of sar transcription . The introduction of each clone also complemented the defect in cna transcription and restored collagen binding to wild-type levels . This was true even when the clones were introduced into a sar/agr double mutant . These results confirm the hypothesis that the sar-mediated regulation of cna transcription occurs via an agr-independent pathway . Direct evidence supporting this hypothesis comes from electrophoretic mobility shift assays demonstrating that SarA exhibits high-affinity binding to cis elements upstream of the cna structural gene . We also examined the correlation between sar transcription and the production of SarA . Western blot analysis of two wild-type strains indicated that SarA was produced in indistinguishable amounts during both the exponential and the post-exponential growth phases.

Mol Microbiol, 1999 Jul, 33(2), 307 - 16
Characterization of the SarA virulence gene regulator of Staphylococcus aureus; Rechtin TM et al.; Staphylococcus aureus is a potent human pathogen that expresses a large number of virulence factors in a temporally regulated fashion . Two pleiotropically acting regulatory loci were identified in previous mutational studies . The agr locus comprises two operons that express a quorum-sensing system from the P2 promoter and a regulatory RNA molecule from the P3 promoter . The sar locus encodes a DNA-binding protein that activates the expression of both agr operons . We have cloned the sarA gene, expressed SarA in Escherichia coli and purified the recombinant protein to apparent homogeneity . The purified protein was found to be dimeric in the presence and absence of DNA and to consist mostly of alpha-helices . DNase I footprinting of SarA on the putative regulatory region cis to the agr promoters revealed three high-affinity binding sites composed of two half-sites each . Quantitative electrophoretic mobility shift assays (EMSAs) were used to derive equilibrium binding constants (KD) for the interaction of SarA with these binding sites . An unusual ladder banding pattern was observed in EMSA with a large DNA fragment including all three binding sites . Our data indicate that SarA regulation of the agr operons involves binding to multiple half-sites and may involve other sites located downstream of the promoters.

Mol Microbiol, 1999 Jul, 33(1), 200 - 7
ZntR is an autoregulatory protein and negatively regulates the chromosomal zinc resistance operon znt of Staphylococcus aureus; Singh VK et al.; A chromosomally encoded znt operon of Staphylococcus aureus consists of two consecutive putative genes designated zntR and zntA . The zntA gene encodes a transmembrane protein that facilitates extrusion of Zn2+ and Co2+, whereas the zntR gene encodes a putative regulatory protein that controls the expression of the znt operon . The zntR gene was amplified using the polymerase chain reaction, cloned into Escherichia coli for overexpression as His-tagged ZntR and purified by Ni2+-affinity column . His-tag-free ZntR was purified to near homogeneity after digestion with enterokinase . Electrophoretic mobility shift assays (EMSAs) indicated that the ZntR bound to a fragment of DNA corresponding to the chromosomal znt promoter region with an affinity of about 8.0 x 10-12 M . The addition of 25 microM Zn2+ or Co2+ in the binding reaction completely or significantly inhibited association of ZntR with the znt promoter . DNase I footprinting assays identified a ZntR binding site encompassing 49 nucleotides in the znt promoter region that contained repeated TGAA sequences . These sequences have been proposed to be the binding sites for SmtB, a metallorepressor protein from the cyanobacterium Synechococcus, to its corresponding operator/promoter . In vitro transcription assays, using S . aureus RNA polymerase, revealed that ZntR represses transcription from the znt promoter in a concentration-dependent fashion . The EMSAs, DNase I footprinting and in vitro transcription assays indicate that ZntR is a trans-acting repressor protein that binds to the znt promoter region and regulates its own transcription together with that of zntA.

Microbiology, 1999 Jun, 145 ( Pt 6), 1325 - 33
Flow cytometry and other techniques show that Staphylococcus aureus undergoes significant physiological changes in the early stages of surface-attached culture; Williams I et al.; The techniques of flow cytometry, scanning and transmission electron microscopy, and confocal scanning laser microscopy were used to study the physiology of Staphylococcus aureus in the early stages of surface-attached culture, and to make direct comparisons with planktonic bacteria grown under the same conditions . Attached bacteria growing in nutrient-rich batch culture were found to go through the same growth phases as equivalent planktonic cultures, but with an exponential growth rate of about half that of the planktonic bacteria . Viability of attached bacteria was very high (around 100%) throughout the first 24 h of growth . The size and protein content of attached bacteria varied with growth phase, and both measurements were always smaller than in planktonic bacteria at equivalent growth phases . Respiratory activity per bacterium, as measured by flow cytofluorimetry, and corrected for cell volume, peaked very early in attached cultures (before the first cell division) and declined from then on, whereas in planktonic bacteria it peaked in late exponential phase . Attached and planktonic bacteria showed thicker cell walls in stationary phase than in exponential phase . Membrane potentials of planktonic and attached bacteria were similar in stationary phase, but were much lower in exponential-phase attached cells than in the equivalent planktonic cells . It is apparent that a range of significant physiological adaptations occur during the early phases of attached growth.

J Gerontol A Biol Sci Med Sci, 1999 Jun, 54(6), B260 - 7
Emerging issues in antibiotic resistant infections in long-term care facilities; Bonomo RA et al.; Managing patients infected with antibiotic resistant bacteria is becoming one of the major clinical obstacles facing physicians who treat patients in long-term care facilities (LTCFs) . Penicillin-resistant pneumococci (PRP), vancomycin-resistant enterococci (VRE), gram-negative bacteria that produce extended-spectrum and ampC-type beta-lactamase enzymes, and quinolone-resistant gram-positive and gram-negative bacteria are the major resistant pathogens that are emerging in these settings . The mechanisms responsible for the evolution of these antibiotic resistant organisms (molecular rearrangement of penicillin binding protein genes, acquisition of a mobile genetic element, and point mutation that alter the active site) are reviewed . Vancomycin intermediate Staphylococcus aureus (VISA) and multidrug efflux pumps in gram-negative bacteria are also threatening our most potent antimicrobials . Aggressive screening, education, antibiotic-control measures, and immunization are advocated as important preventive measures . The combined efforts of the medical directors, infection-control personnel, and administrators are needed to stem this problem.

Can J Microbiol, 1999 Mar, 45(3), 250 - 6
Staphylococcus aureus isogenic mutant, deficient in toxic shock syndrome toxin-1 but not staphylococcal enterotoxin A production, exhibits attenuated virulence in a tampon-associated vaginal infection model of toxic shock syndrome; De Boer ML et al.; Since menstrual toxic shock syndrome (MTSS) is associated with a predominant clone of Staphylococcus aureus which produces both toxic shock syndrome toxin-1 (TSST-1) and staphylococcal enterotoxin A (SEA), we sought to clarify the role of TSST-1 in a tampon-associated vaginal infection model in New Zealand White (NZW) rabbits, using isogenic tst+/sea+ S . aureus mutants in which tst was inactivated by allelic replacement . Rabbits infected with the tst-/sea+ strain became ill within 3 days, with fever, weight loss, conjunctival hyperemia, and lethargy . Mortality was significantly higher with the tst+/sea+ strain compared to its tst-/sea+ isogenic derivative (4/13 vs . 0/14; p < 0.05, Fisher's exact test, 2-tailed) . Mean fever index was higher (p < 0.005; t test, 2-tailed) and weight loss more sustained among survivors in the tst+/sea+ group . Furthermore, culture filtrates from the tst+/sea+ strain induced a significantly greater response in mitogenesis and TNF alpha secretion from rabbit splenocytes in vitro compared to the tst-/sea+ isogenic derivative . Thus, regardless of the role of SEA, TSST-1 significantly contributed to both morbidity and mortality in this tampon-associated vaginal infection model in NZW rabbits . This is the first demonstration of the potential role of TSST-1 and SEA in the pathogenesis of MTSS with a MTSS-associated clinical S . aureus strain in a relevant animal model.

J Clin Microbiol, 1999 Aug, 37(8), 2446 - 9
Involvement of enterotoxins G and I in staphylococcal toxic shock syndrome and staphylococcal scarlet fever; Jarraud S et al.; We investigated the involvement of the recently described staphylococcal enterotoxins G and I in toxic shock syndrome . We reexamined Staphylococcus aureus strains isolated from patients with menstrual and nonmenstrual toxic shock syndrome (nine cases) or staphylococcal scarlet fever (three cases) . These strains were selected because they produced none of the toxins known to be involved in these syndromes (toxic shock syndrome toxin 1 and enterotoxins A, B, C, and D), enterotoxin E or H, or exfoliative toxin A or B, despite the fact that superantigenic toxins were detected in a CD69-specific flow cytometry assay measuring T-cell activation . Sets of primers specific to the enterotoxin G and I genes (seg and sei, respectively) were designed and used for PCR amplification . All of the strains were positive for seg and sei . Sequence analysis confirmed that the PCR products, corresponded to the target genes . We suggest that staphylococcal enterotoxins G and I may be capable of causing human staphylococcal toxic shock syndrome and staphylococcal scarlet fever.

J Antimicrob Chemother, 1999 Jun, 43 Suppl C, 67 - 70
Levofloxacin: serum bactericidal activity against methicillin-resistant Staphylococcus aureus isolates; Muller-Serieys C et al.; The aim of this study was to assess the serum bactericidal activity (SBA) of levofloxacin compared with that of ofloxacin against methicillin-resistant Staphylococcus aureus (MRSA) isolates . Serum from 10 healthy volunteers (seven females, three males) was collected after a single oral dose of either levofloxacin (500 mg) or ofloxacin (400 mg) . Subjects were allocated randomly to treatment after at least a 1 week interval between antibiotic regimens . Three well-defined MRSA strains were tested, each susceptible to levofloxacin and ofloxacin, with different levels of resistance to methicillin (HBD 456, HBD 3 and HBD 2; class 1, 2 and 3 Tomasz heterogeneous resistance, respectively) together with a methicillin-susceptible (MSSA) reference strain (S . aureus ATCC 25,923) . SBA was tested in vitro by a microtitration method 15 min before dosing and at 1, 4, 8 and 12 h after drug absorption . Levofloxacin was significantly more bactericidal than ofloxacin against all strains of S . aureus tested (SBA > or = 1:2) . An SBA was recorded for only a short period with ofloxacin, and thereafter only bacteriostatic activity remained . This study, therefore, confirms the superior activity of levofloxacin over that of ofloxacin against MSSA and MRSA.

J Antimicrob Chemother, 1999 Jun, 43(6), 805 - 9
The postantibiotic effect of N-chlorotaurine on Staphylococcus aureus . Application in the mouse peritonitis model; Nagl M et al.; This study was designed to investigate the delay of regrowth (postantibiotic effect) in the presence of N-chlorotaurine (NCT), an endogenous active N-chlorine compound, of Staphylococcus aureus, strain Smith diffuse . The low reactivity of NCT enabled clear temporal separation of the postantibiotic and killing effect to be defined . Delay of regrowth proved to be dependent both on concentration of NCT, and incubation time . The maximum delay was 3 h . Using the model of lethal staphylococcal peritonitis in mice, in-vivo delay of regrowth of bacteria pretreated with N-chlorotaurine could be demonstrated to correlate with survival . It is concluded that the postantibiotic effect of N-chlorotaurine could be an important factor on decreasing virulence of bacteria . This effect was observed after relatively short incubation times.

Clin Exp Immunol, 1999 Jul, 117(1), 63 - 9
Protective role of NK1.1+ cells in experimental Staphylococcus aureus arthritis; Nilsson N et al.; In a model of Staphylococcus aureus-induced septic arthritis in C57Bl/6 mice we investigated the role of natural killer (NK) cells in the development of disease . Depletion of NK1.1+ cells was achieved by repeated injections of the PK136 antibody, whereas control mice received an irrelevant monoclonal antibody, O1C5.B2 . Both groups of mice then received injections intravenously with 2 x 107 live S . aureus LS-1 secreting toxic shock syndrome toxin-1 (TSST-1) . The mice were evaluated for 16 days with regard to weight, mortality and arthritis . Nine days after bacterial injection, 9/19 mice depleted of NK cells had developed arthritis compared with 1/17 in the control group (P = 0.01) . The experiment was repeated twice with the same outcome . NK cell-depleted and control mice displayed the same degree of histopathological signs of arthritis at day 16 . Depletion of NK cells did not affect uptake of bacteria by phagocytic cells in vitro, or bacterial clearance in vivo . In NK cell-depleted mice there was a tendency to increased levels of antibodies to TSST-1, whereas total immunoglobulin levels were similar to those in controls . NK cell depletion of non-infected mice did not affect the magnitude of inflammatory response during the T cell-dependent cutaneous DTH reaction to oxazolone, or during granulocyte-mediated inflammation . However, specific antibody responses to oxazolone were greatly increased in depleted animals . In conclusion, our study demonstrates that NK cells protect against arthritis during S . aureus infection . This outcome does not seem to be due to an influence on bacterial clearance, but could be due to an interaction with the host anti-inflammatory mechanisms.

Toxicol Lett, 1999 Jun 1, 106(2-3), 119 - 27
Glutathione reduces the toxicity associated with antitumor therapy of ascites fluid adsorbed over Staphylococcus aureus Cowan I in tumor bearing mice; Verma AS et al.; It has been well documented in the literature that the removal of circulatory immune complexes (CICs) from the host circulation leads to the immunopotentiation as well as generation of antitumor responses in a variety of tumors in rats, cats, dogs and human patients . CICs are the major immunosuppressive factors in tumor bearing host . Protein A (PA) has been extensively used for the removal of these CICs from the sera/plasma of tumor bearers, because PA has the ability to bind with the Fc portion of mammalian immunoglobulins . Previously, we reported for the first time a potent antitumor response by the inoculation of cell free Ehrlich's ascites fluid adsorbed in vitro over PA containing Staphylococcus aureus Cowan I (SAC) in Ehrlich's ascites tumor model . However, there was toxicity associated with this form of therapy in terms of early death of treated animals and the depletion of hepatic glutathione pool as well as phase I biotransformation enzyme and increase in glutathione-S-transferase (GST) activities . In the present investigation, tumor bearing animals were treated intraperitoneally (i.p.) on alternate days for 15 days with adsorbed ascites fluid (ad-ASF) (0.1 ml) and glutathione (GSH) (250 mg/kg body weight) separately . We found that GSH supplementation increases mean survival time of GSH and ad-ASF treated mice up to 37.2 days in comparison with 19.9 days for only ad-ASF treated animals, while percent increase in body weight was found to be not affected by the GSH substitution, which remains significantly lower (P < 0.01) in comparison to the tumor control animals . GSH supplementation causes a significant decrease (P < 0.05) of glutathione-S-transferase and restoration of aniline hydroxylase activity (P < 0.05) and aminopyrine-N-demethylase activity . We have also observed that GSH supplementation does not alter the tumor cell viability and tumor cell counts in ad-ASF treated animals in comparison to only ad-ASF treated animals, which indicates that GSH supplementation does not alter the antitumor effect of the therapy . Treatment of Ehrlich's ascites tumor bearing mice with ad-ASF and glutathione increased their survival, but did not reduce the mortality of animals because of tumor.

Lab Anim Sci, 1999 Jun, 49(3), 283 - 7
Model of Staphylococcus aureus central venous catheter-associated infection in rats; Ulphani JS et al.; BACKGROUND AND PURPOSE: Staphylococcus aureus is an important cause of intravascular catheter-associated bacteremia . We developed a rat central venous catheter (CVC)-associated infection model to study pathogenesis and treatment . METHODS: A silastic lumen-within-lumen catheter and rodent-restraint jacket were designed . Subcutaneously tunneled catheters were inserted in the jugular vein of 20 male Sprague Dawley rats . Twelve rats (group 1) were inoculated with S . aureus via the CVC; three rats (group 2) were inoculated with S . aureus via the tail vein, five rats (group 3) served as uninfected controls; and three rats (group 4) were inoculated with S . aureus via the tail vein but did not undergo CVC insertion . Five to eight days after inoculation, animals were euthanized, CVCs were aseptically removed, and quantitative culture was done . Quantitative culture also was performed on blood, heart, liver, lungs, and kidneys . RESULTS: Infection, characterized by bacteremia and metastatic disease, was observed in all rats inoculated via the CVC with as few as 100 colony-forming units (CFU) of S . aureus . Rats of group 2 were not as likely to develop CVC-associated infection, and none of the animals of groups 3 or 4 developed infection . CONCLUSIONS: This model of CVC-associated infection should prove suitable for studying pathogenesis and treatment of the condition.

J Med Microbiol, 1999 Jul, 48(7), 697 - 700
Microbiology of retroperitoneal abscesses in children; Brook I; Samples of pus from 41 children with retroperitoneal abscess treated between 1974 and 1994 yielded a total of 125 organisms (3.0 isolates/specimen); 58 isolates were aerobic and facultative species (1.4/specimen) and 67 were anaerobic (1.6/specimen) . Aerobic bacteria only were isolated from 7 (17%) abscesses, anaerobic bacteria only from 3 (7%) and mixed aerobic and anaerobic bacteria from 31 (76%); 34 (83%) infections were polymicrobial . The predominant aerobic and facultative isolates were Escherichia coli (19 isolates) and Staphylococcus aureus (6), and the predominant anaerobes were Peptostreptococcus spp . (18 isolates), Bacteroides spp . (22) and Prevotella spp . (5).

Kyobu Geka, 1999 Jul, 52(7), 563 - 8
{Methicillin-resistant Staphylococcus aureus (MRSA) mediastinitis after cardiovascular operations}; Yamaguchi H et al.; We described three cases of poststernotomy mediastinitis caused by MRSA . The first case 74-year-old woman who had undergone emergent CABG was treated by continuous closed irrigation and consecutive omental transfer . She was suffered from multiple organ failure and died . The other two cases 50-year-old woman and 66-year-old man after double valves replacement and total aortic arch replacement were managed successfully with simultaneous combination of surgical debridement and placement of omental flap . It was seemed that early aggressive surgical procedures before deterioration of general conditions associated with improvement of mortality . Additionally, it was considered that to avoid residual dead space in presternum as well as in mediastinum was essential to decrease the morbidity and hospital stay, especially in case of MRSA infection.

Dev Comp Immunol, 1999 Apr, 23(3), 241 - 52
Natural and induced apoptosis during lymphocyte development in the axolotl; Ducoroy P et al.; Lymphocytes apoptosis was characterized in a urodele amphibian, the axolotl, by morphology using electron microscopy and by flow cytometry after propidium iodide staining, as well as by biochemical criteria with the detection of DNA ladders after glucocorticoid treatment . The morphological and biochemical features observed in treated axolotls are in accordance with the criteria of apoptosis found in different models of mammalian lymphocyte programmed cell death . The onset of natural apoptosis was then detected by DNA fragmentation in thymus and in spleen during lymphocyte development and ontogenesis . A typical DNA ladder characteristic of apoptosis is detectable in the thymus as early as 5 months; apoptosis increases and peaks at 8 months, and is no longer detected by 10 months or thereafter . The ability of a superantigen, Staphylococcus aureus enterotoxin B (SEB), to induce T lymphocyte apoptosis in larvae was investigated as well . In vivo exposure of young axolotl larvae to SEB induces, as in mammals, thymocyte apoptosis as indicated by the enhancement of DNA fragmentation . These last results, natural programmed cell death and SEB induced apoptosis during thymic ontogeny, are discussed in correlation with what is known during mammalian thymic selection and apoptosis.

Arch Intern Med, 1999 Jul 12, 159(13), 1437 - 44
Risk factors for hospital-acquired Staphylococcus aureus bacteremia; Jensen AG et al.; BACKGROUND: Staphylococcus aureus bacteremia (SAB) acquired in hospitals continues to be a frequent and serious complication to hospitalization, and no previous case-control studies dealing with risk factors of this severe disease are available . METHODS: Based on a 1-year prospective analysis, the data from all patients with hospital-acquired SAB admitted to 4 hospitals in Copenhagen County, Denmark, from May 1, 1994, through April 30, 1995, were evaluated . Eighty-five patients with hospital-acquired SAB were matched to 85 control patients with a similar primary diagnosis at admission (matched controls) . Of these, 62 patients with hospital-acquired SAB were compared with 118 other patients with a similar time of admission, who were randomly selected with no clinical evidence of SAB (unmatched controls) . RESULTS: The incidence of hospital-acquired SAB was 0.71 per 1000 hospital admissions . The presence of a central venous catheter (odds ratio, 6.9; 95% confidence interval {CI}, 2.8-17.0), anemia (odds ratio, 3.3; 95% CI, 1.4-7.6), and hyponatremia (odds ratio, 3.3; 95% CI, 1.5-7.0) was significantly associated with hospital-acquired SAB in a conditional and a usual logistic regression analysis . Nasal carriage was not an independent risk factor, but nasal carriers among patients in surgery (odds ratio, 4.0; 95% CI, 1.3-13.0) had a significantly higher risk for hospital-acquired SAB compared with matched and unmatched controls . The presence of hospital-acquired SAB increased the mortality rate 2.4-fold (95% CI, 1.1-5.2) . CONCLUSIONS: The presence of a central venous catheter is an important risk factor, and hyponatremia and anemia are associated with the development of hospital-acquired SAB . Furthermore, hospital-acquired SAB in itself increases mortality.

Microbios, 1998, 96(385), 149 - 55
The antibacterial activity of plaunotol against Staphylococcus aureus isolated from the skin of patients with atopic dermatitis; Matsumoto Y et al.; Plaunotol was tested for possible antibacterial activity against twenty strains of methicillin-resistant Staphylococcus aureus (MRSA) and fourteen strains of methicillin-sensitive S . aureus (MSSA) which had been isolated from the skin of patients with atopic dermatitis under growth-promoting conditions . Plaunotol was effective against all strains tested . The dose of plaunotol for 50% inhibition of growth (ID50) ranged from 2.5 to 16 micrograms/ml for strains of MRSA and from 2.5 to 7.0 micrograms/ml for those of MSSA . These results suggest that plaunotol may be useful in the prevention of infection by MRSA and in skin care for patients with atopic dermatitis.

Luminescence, 1999 Jan-Feb, 14(1), 33 - 8
Evaluation of two methods for monitoring surface cleanliness-ATP bioluminescence and traditional hygiene swabbing; Davidson CA et al.; The minimum bacterial detection limits and operator reproducibility of the Biotrace Clean-Tracetrade mark Rapid Cleanliness Test and traditional hygiene swabbing were determined . Areas (100 cm2) of food grade stainless steel were separately inoculated with known levels of Staphylococcus aureus (NCTC 6571) and Escherichia coli (ATCC 25922) . Surfaces were sampled either immediately after inoculation while still wet, or after 60 min when completely dry . For both organisms the minimum detection limit of the ATP Clean-Tracetrade mark Rapid Cleanliness Test was 10(4) cfu/100 cm2 (p < 0.05) and was the same for wet and dry surfaces . Both organism type and surface status (i.e . wet or dry) influenced the minimum detection limits of hygiene swabbing, which ranged from 10(2) cfu/100 cm2 to >10(7) cfu/100 cm2 . Hygiene swabbing percentage recovery rates for both organisms were less than 0.1% for dried surfaces but ranged from 0.33% to 8.8% for wet surfaces . When assessed by six technically qualified operators, the Biotrace Clean-Tracetrade mark Rapid Cleanliness Test gave superior reproducibility for both clean and inoculated surfaces, giving mean coefficients of variation of 24% and 32%, respectively . Hygiene swabbing of inoculated surfaces gave a mean CV of 130% . The results are discussed in the context of hygiene monitoring within the food industry .

J Biomed Mater Res, 1999 Sep 15, 46(4), 494 - 503
Sulbactam-cefoperazone polyhydroxybutyrate-co-hydroxyvalerate (PHBV) local antibiotic delivery system: in vivo effectiveness and biocompatibility in the treatment of implant-related experimental osteomyelitis; Yagmurlu MF et al.; In this study, a novel antibiotic carrier system for use in the treatment of implant-related and chronic osteomyelitis was developed . Sulbactam-cefoperazone was introduced to rods of polyhydroxybutyrate-co-hydroxyvalerate (22 mol % HV, w/w), a member of a family of microbial-origin polymer that is biodegradable, biocompatible, and osteoconductive due to its piezoelectric property . The antibiotic-loaded carrier was implanted into the infection site that was induced by Staphylococcus aureus inoculation into the rabbit tibia . The effectiveness of this was assessed macroscopically, radiographically, bacteriologically, and histopathologically . Findings of infection subsided on day 15 and almost complete remission was observed on day 30 . The control side that contained antibiotic-free rods, however, worsened . These findings prompted us to conclude that the novel biodegradable antibiotic carrier developed in the present study seems to be a promising candidate for use in the treatment of severe bone infection .

Mol Gen Mikrobiol Virusol, 1999, (2), 29 - 34
Staphylococcus aureus isolated from Kawasaki disease patients hyper-releases extracellular protein A; Ezepchuk YV et al.; S . aureus isolates from patients with Kawasaki disease (KD) release high levels of extracellular protein A (SpA), as compared to S . aureus in other diseases . The molecular weight of this released protein A is about 70 kDa . Extracellular KD SpA purified by affinity chromatography possessed the same amino acid sequence at the NH2-terminal IgG binding region and the same antigenic specificity as recombinant and cell-wall-bound SpA preparations . The size of DNA fragments containing the spa gene from S . aureus KD strains was 160-165 kb . All of these DNA fragments contained the igb portion encoding the IgG-binding region of KD SpA . Significantly higher molecular size of the SpA molecules hyper-released in the stationary-phase culture and the lack of production of other exo-proteins allow us to speculate that S . aureus isolated from patients with KD have mutations occurring in the agr locus.

Avian Dis, 1999 Apr-Jun, 43(2), 227 - 33
Effect of hydrogen peroxide disinfection during incubation of chicken eggs on microbial levels and productivity; Sander JE et al.; Hatchery sanitation has a significant impact on chick quality . The proper use of disinfectants is essential . Aerosol bacterial counts, egg moisture loss, hatchability, chick quality, and broiler productivity were measured in eggs exposed to hydrogen peroxide fogging and compared with eggs not exposed to disinfectant during the incubation period . Hydrogen peroxide was also evaluated in the presence of a severe challenge with Staphylococcus aureus-contaminated eggs . A significant reduction was found in aerosol bacterial counts within the hatcher when incubators were fogged with 3% hydrogen peroxide when compared with water-fogged machines even in the face of high bacterial challenge . Eggs exposed to hydrogen peroxide lost a significantly greater amount of moisture during incubation, but hatchability was not affected . The use of hydrogen peroxide as a hatchery sanitizer did not affect broiler livability, body weight, or feed conversion but did reduce the incidence of retained yolk sacs in 42-day-old chickens.

Avian Dis, 1999 Apr-Jun, 43(2), 167 - 71
Organ culture of chicken bursa as a model to study the pathogenicity of infectious bursal disease virus isolates; Shakya S et al.; In vitro study with chicken bursal organ culture was attempted to assess the pathogenicity of locally isolated infectious bursal disease virus (IBDV) initially isolated from the bursa of naturally infected birds . In bursal organ culture, lymphoblastic transformation was noticed as early as 24 hr postinoculation and reached maximum at 72 hr postinoculation . The other microscopic changes were increased number of macrophages and formation of plasma cells . The IBDV antigen was detected 24 hr onward by coagglutination test with antibody coated Staphylococcus aureus strain Cowan I . On the basis of lesion score, the three isolates of IBDV (A, B, and C) were graded as virulent (B isolate) and moderately virulent (A and C isolates) . A similar pattern of pathogenicity was also observed in the in vivo pathogenicity studies in chicken based on bursa: body weight ratio and histopathologic lesion score . The bursal organ culture thus provides a useful experimental model to differentiate the IBDV isolates on the basis of their virulence.

J Microbiol Methods, 1999 Jul, 37(1), 7 - 15
Use of fluorescent amplified fragment length polymorphism (fAELP) to characterise methicillin-resistant Staphylococcus aureus; Hookey JV et al.; The new PCR-based genotyping technique, fluorescent amplified fragment length polymorphism (fAFLP), was compared for discriminatory power and reproducibility with standard phenotypic methods, a coagulase gene (coa) restriction fragment length polymorphism (RFLP) method and pulsed-field gel electrophoresis (PFGE), in typing 34 isolates and four reference strains of methicillin-resistant Staphylococcus aureus (MRSA) . The fAFLP showed from 40 to 75 fragments, 50 to 450 base pairs (bp) in size . Based on replicate studies, the isolates were judged indistinguishable when their fAFLP pattern was >93.7% similar . Only two of the isolates were indistinguishable by this criterion . Thirty-one MRSA fell into four major fAFLP groups (1, 2, 3 and 4) at the level of >79.9% similarity . Three other isolates and an EMRSA-16 strain fell outside these major groups . Within both fAFLP groups 1 and 2, two subgroups, A and B, could be identified at approximately 82.0% similarity . While most isolates within group 1 could also be separated by their phenotypic and coagulase gene (coa) RFLP pattern, all the isolates within fAFLP groups 2A and 2B were identical on the basis of these characters . The MRSA within fAFLP groups 3 and 4 were heterogeneous by their phenotypic characteristics and coa gene RFLP patterns . fAFLP was reproducible and distinguished between MRSA isolates that appeared identical by other methods . It is likely to contribute to the epidemiological analysis of outbreaks of MRSA infection.

Infect Control Hosp Epidemiol, 1999 Jun, 20(6), 408 - 11
Nosocomial methicillin-resistant and methicillin-susceptible Staphylococcus aureus primary bacteremia: at what costs?
Abramson MA, Sexton DJ.
OBJECTIVE: To determine the attributable hospital stay and costs for nosocomial methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant S . aureus (MRSA) primary bloodstream infections (BSIs) . DESIGN: Pairwise-matched (1:1) nested case-control study . SETTING: University-based tertiary-care medical center . PATIENTS: Patients admitted between December 1993 and March 1995 were eligible . Cases were defined as patients with a primary nosocomial S . aureus BSI; controls were selected according to a priori matching criteria . MEASUREMENTS: Length of hospital stay and total and variable direct costs of hospitalization . RESULTS: The median hospital stay attributable to primary nosocomial MSSA BSI was 4 days, compared with 12 days for MRSA (P=.023) . Attributable median total cost for MSSA primary nosocomial BSIs was $9,661 versus $27,083 for MRSA nosocomial infections (P=.043) . CONCLUSION: Nosocomial primary BSI due to S . aureus significantly prolongs the hospital stay . Primary nosocomial BSIs due to MRSA result in an approximate threefold increase in direct cost, compared with those due to MSSA.

J Vasc Surg, 1999 Jul, 30(1), 92 - 8
In situ replacement of infected aortic grafts with rifampicin-bonded prostheses: the Leicester experience (1992 to 1998)
Hayes PD, Nasim A, London NJ, Sayers RD, Barrie WW, Bell PR, Naylor AR.
PURPOSE: Prosthetic graft infection after aortic aneurysm surgery is a life-threatening complication . Treatment options include total graft excision and extra-anatomic bypass grafting or in situ replacement of the graft . The latter option is gaining increasing popularity, but the long-term outcome remains uncertain, particularly in light of the increasing prevalence of methicillin-resistant Staphylococcus aureus (MRSA) . We performed a prospective nonrandomized study to assess the outcome after graft excision and in situ replacement with a rifampicin-bonded prosthesis for the treatment of major aortic graft infection . METHODS: In a 6-year period from January 1992 to December 1997, 11 patients (eight men, three women) with major aortic graft infection underwent total graft excision and in situ replacement with a rifampicin-bonded prosthesis . The median age of the patients was 66 years (range, 49 to 78 years) . Four patients had a hemorrhage from an aortoenteric fistula, three had a retroperitoneal abscess, two had graft occlusion, one had a perigraft collection shown by means of computed tomography, and one had a ruptured suprarenal false aneurysm . Organisms were cultured from 10 patients . RESULTS: MRSA was isolated in two patients, both of whom had originally undergone repair of a ruptured abdominal aortic aneurysm . Two patients died (18.2%) within 30 days, and three patients (27.6%) had nonfatal complications (peritoneal candidiasis, transient renal impairment, and profound anorexia) . Two patients died late in the follow-up period . Seven patients remain alive and clinically free of infection . CONCLUSION: The long-term results after total graft excision and in situ replacement with a rifampicin-bonded prosthesis appear to be favorable . However, MRSA aortic graft infection appears to be associated with a poor prognosis.

Vet Microbiol, 1999 Jun 1, 67(1), 37 - 46
Colonization of rabbits with Staphylococcus aureus in flocks with and without chronic staphylococcosis; Hermans K et al.; Rabbits of 19 rabbitries were examined for the presence of Staphylococcus aureus in nine different body sites . Seven rabbitries experienced epidemically spreading signs of staphylococcosis while the other 12 rabbitries did not . S . aureus was isolated in all seven flocks that suffered from chronic problems of staphylococcosis and in 11 of the 12 clinically healthy flocks . The mean percentage of infected animals in these two groups was 90 and 43.3%, respectively . S . aureus was isolated from all body sites examined, but the ear and the perineum were often more intensely colonized . The number of animals colonized with S . aureus and the mean number of positive body sites in S . aureus positive rabbits were significantly higher in rabbitries with chronic staphylococcosis . This indicates that colonization capacity of S . aureus plays a role in epidemically spreading disease in rabbits . S . aureus isolates belonged to five different biotypes and 23 different phage types . Several different types simultaneously circulated in contaminated rabbitries and even simultaneously infected individual rabbits . Strains that belonged to the biotype-phage type combination mixed CV-C, 3A/3C/55/71 only occurred in rabbitries chronically dealing with signs of staphylococcosis . This may indicate a relationship between phenotypic strain properties and virulence of S . aureus.

Pediatr Allergy Immunol, 1999, 10(12 Suppl), 19 - 23
Atopic eczema: how to tackle the most common atopic symptom; Wahn U et al.; The disease management of atopic eczema includes topical and systemic treatments as well as the control of allergic and non-allergic trigger factors . The basis for topical treatment is the regular use of emollients . In addition, anti-inflammatory treatment with -- preferably mild -- topical steroids is the treatment of choice . At least-one third of the children with atopic eczema during the first years suffer from clinically relevant food allergy requiring elimination diets for at least one or two years . The most common cause of superinfection is Staphylococcus aureus . Recent data suggests that it may induce purulent superinfection as well as enhance the inflammatory process by superantigen mediated T-cell activation . Also, a number of alternative treatment strategies have been investigated during the last decade: the use of gamma-linoleic acid has been shown to be of limited benefit, while studies on interferon-gamma and on high-dose intravenous gamma-globulin are still anecdotal . The long-term effectiveness of disease management in atopic eczema depends largely on the understanding of the disease process as well as on the compliance of the parents . Thus, coping with the problem will be easier if the patient or the parents have been educated in understanding the pathogenesis, the role of trigger factors, the possibilities of prevention and the different treatment strategies.

Rev Alerg Mex, 1999 Mar-Apr, 46(2), 41 - 8
{Effect of Staphylococcus aureus extract on the expression of L-selectin and LFA-1, in neutrophils from patients with allergic bronchial asthma}; Rojas Ramos E et al.; OBJECTIVE: Messier L-selectin and LFA-1 in neutrophils from moderate and non atopic asthma patients, before and after stimuli with and without Sa (Staphylococcus aureus) . MATERIALS AND METHOD: Design Trial; experimental . We studied neutrophils from 12 moderate and non atopic asthma patients and 12 healthy subjects before and after stimuli with and without Sa . Measures: The neutrophyls adhesion molecules, CD 62-L and CD 11 a was measured by citometric flow assays . RESULTS: The median of CD 62-L molecule expression increase with the stimuli in non atopic asthma patients from 2444 (CI 1966, CS 3627, RC 1661) to 6285.5 (CI 5243, CS 7203, RC 1960), and the median of CD 11 a molecule expression decrease with the stimuli in non atopic asthma patients from 9910.5 (CI 9765, CS 9961, RC 196) to 7670 (CI 7125, CS 8291, RC 1166) . The median of CD 11 a molecule expression increase with the stimuli in healthy subjects from 593 (CI 361, CS 929, RC 568) to 1113 (CI 910, CS 1240, RC 330) and the median of CD 11 a molecule expression decrease with the stimuli in healthy subjects from 9850 (CI 9741, CS 9898, RC 157) to 9808.5 (CI 9693, CS 9890, RC 197) {CI . Inferior Cuartil, CS . Superior Cuartil, RC.-Cuartil Range}.

Can Commun Dis Rep, 1999 Jun 15, 25(12), 105 - 8
Characterization and proposed nomenclature of epidemic strains of methicillin-resistant Staphylococcus aureus in Canada; Simor A et al.; We hope that standardized nomenclature for identifying epidemic MRSA strains prevalent in Canadian hospitals will be helpful to physicians and infection control practitioners attempting to understand and control the spread of the organism in health-care facilities . It is anticipated that as MRSA continues to evolve in Canadian health-care facilities other strains may be recognized as "epidemic"; as these strains become better characterized they may be added to those designated above . Laboratory physicians and infection control personnel are invited to submit strains that may warrant characterization and designation as a Canadian epidemic strain to the Laboratory Centre for Disease Control, Health Canada, Winnipeg, Manitoba.

Antimicrob Agents Chemother, 1999 Jul, 43(7), 1756 - 8
Effect of fluoroquinolone concentration on selection of resistant mutants of Mycobacterium bovis BCG and Staphylococcus aureus; Dong Y et al.; When Mycobacterium bovis BCG and Staphylococcus aureus were plated on agar containing increasing concentrations of fluoroquinolone, colony numbers exhibited a sharp drop, followed by a plateau and a second sharp drop . The plateau region correlated with the presence of first-step resistant mutants . Mutants were not recovered at concentrations above those required for the second sharp drop, thereby defining a mutant prevention concentration (MPC) . A C-8-methoxy group lowered the MPC for an N-1-cyclopropyl fluoroquinolone.

Antimicrob Agents Chemother, 1999 Jul, 43(7), 1754 - 5
Lysostaphin treatment of experimental aortic valve endocarditis caused by a Staphylococcus aureus isolate with reduced susceptibility to vancomycin; Patron RL et al.; The rabbit model of endocarditis was used to test the effectiveness of vancomycin and two different lysostaphin dosing regimens for the treatment of infections caused by a Staphylococcus aureus strain with reduced susceptibility to vancomycin (glycopeptide-intermediate susceptible S . aureus {GISA}) . Vancomycin was ineffective, with no evidence of sterilization of aortic valve vegetations . However, rates of sterilization of aortic valve vegetations were significantly better for animals treated with either a single dose of lysostaphin (43%) or lysostaphin given twice daily for 3 days (83%) than for animals treated with vancomycin . Rabbits given a single dose of lysostaphin followed by a 3-day drug-free period had mean reductions in aortic valve vegetation bacterial counts of 7.27 and 6.63 log10 CFU/g compared with those for untreated control rabbits and the vancomycin-treated group, respectively . We conclude that lysostaphin is an effective alternative for the treatment of experimental aortic valve endocarditis caused by a clinical VISA strain.

Antimicrob Agents Chemother, 1999 Jul, 43(7), 1737 - 42
Comparative efficacies of liposomal amikacin (MiKasome) plus oxacillin versus conventional amikacin plus oxacillin in experimental endocarditis induced by Staphylococcus aureus: microbiological and echocardiographic analyses; Xiong YQ et al.; Optimal treatment strategies for serious infections caused by Staphylococcus aureus have not been fully characterized . The combination of a beta-lactam plus an aminoglycoside can act synergistically against S . aureus in vitro and in vivo . MiKasome, a new liposome-encapsulated formulation of conventional amikacin, significantly prolongs serum half-life (t1/2) and increases the area under the concentration-time curve (AUC) compared to free amikacin . Microbiologic efficacy and left ventricular function, as assessed by echocardiography, were compared in animals administered either oxacillin alone or oxacillin in combination with conventional amikacin or MiKasome in a rabbit model of experimental endocarditis due to S . aureus . In vitro, oxacillin, combined with either free amikacin or MiKasome, prevented the bacterial regrowth observed with aminoglycosides alone at 24 h of incubation . Rabbits with S . aureus endocarditis were treated with either oxacillin alone (50 mg/kg, given intramuscularly three times daily), oxacillin plus daily amikacin (27 mg/kg, given intravenously twice daily), or oxacillin plus intermittent MiKasome (160 mg/kg, given intravenously, a single dose on days 1 and 4) . The oxacillin-alone dosage represents a subtherapeutic regimen against the infecting strain in the endocarditis model (L . Hirano and A . S . Bayer, Antimicrob . Agents Chemother . 35:685-690, 1991), thus allowing recognition of any enhanced bactericidal effects between oxacillin and either aminoglycoside formulation . Treatment was administered for either 3 or 6 days, and animals were sacrificed after each of these time points or at 5 days after a 6-day treatment course (to evaluate for posttherapy relapse) . Left ventricular function was analyzed by utilizing serial transthoracic echocardiography during treatment and posttherapy by measurement of left ventricular fractional shortening . At all sacrifice times, both combination regimens significantly reduced S . aureus vegetation counts versus control counts (P < 0.05) . In contrast, oxacillin alone did not significantly reduce S . aureus vegetation counts after 3 days of therapy . Furthermore, at this time point, the two combinations were significantly more effective than oxacillin alone (P < 0.05) . All three regimens were effective in significantly decreasing bacterial counts in the myocardium during and after therapy compared to controls (P < 0.05) . In kidney and spleen abscesses, all regimens significantly reduced bacterial counts during therapy (P < 0.0001); however, only the combination regimens prevented bacteriologic relapse in these organs posttherapy . By echocardiographic analysis, both combination regimens yielded a significant physiological benefit by maintaining normal left ventricular function during treatment and posttherapy compared with oxacillin alone (P < 0.001) . These results suggest that the use of intermittent MiKasome (similar to daily conventional amikacin) enhances the in vivo bactericidal effects of oxacillin in a severe S . aureus infection model and preserves selected physiological functions in target end organs.

Antimicrob Agents Chemother, 1999 Jul, 43(7), 1719 - 24
Reversal of tetracycline resistance mediated by different bacterial tetracycline resistance determinants by an inhibitor of the Tet(B) antiport protein; Nelson ML et al.; Active efflux is a useful strategy by which bacteria evade growth inhibition by antibiotics . Certain semisynthetic tetracycline (TC) analogs, substituted at the 13th carbon at C-6 on ring C of the TC molecule, blocked TC efflux as revealed in everted membrane vesicles from class B TC-resistant (Tcr) Escherichia coli (M . L . Nelson, B . H . Park, J . S . Andrews, V . A . Georgian, R . C . Thomas, and S . B . Levy, J . Med . Chem . 36:370-377, 1993) . A representative C-13-substituted analog, 13-cyclopentylthio-5-OH-TC (13-CPTC), was shown to competitively inhibit TC translocation by the Tet(B) protein, blocking the uptake of TC into vesicles and therefore the efflux of TC from whole cells . Against Tcr E . coli, 13-CPTC, when used in combination with doxycycline, produced synergistic inhibition of growth . 13-CPTC was shown to increase the uptake of {3H}TC into the resistant cells . 13-CPTC alone was a potent growth inhibitor against TC-susceptible (Tcs) and Tcr Staphylococcus aureus and enterococci specifying class K or class L efflux-dependent TC resistance mechanisms or, unexpectedly, the class M ribosomal protection mechanism . These findings indicate that derivatives of TC, identified by their ability to block the Tet(B) efflux protein, can restore TC activity against Tcr bacteria bearing either of the two known resistance mechanisms . Blocking drug efflux and increasing intracellular drug concentrations constitute an effective approach to reversing TC resistance and may be generally applicable to other antibiotics rendered ineffective by efflux proteins.

Antimicrob Agents Chemother, 1999 Jul, 43(7), 1578 - 83
Cloning and characterization of a gene, pbpF, encoding a new penicillin-binding protein, PBP2B, in Staphylococcus aureus; Komatsuzawa H et al.; A previously unrecognized penicillin binding protein (PBP) gene, pbpF, was identified in Staphylococcus aureus . This gene encodes a protein of 691 amino acid residues with an estimated molecular mass of 78 kDa . The molecular mass is very close to that of S . aureus PBP2 (81 kDa), and the protein is tentatively named PBP2B . PBP2B has three motifs, SSVK, SSN, and KTG, that can be found in PBPs and beta-lactamases . Recombinant PBP2B (rPBP2B), which lacks a putative signal peptide at the N terminus and has a histidine tag at the C terminus, was expressed in Escherichia coli . The purified rPBP2B was shown to have penicillin binding activity . A protein band was detected from S . aureus membrane fraction by immunoblotting with anti-rPBP2B serum . Also, penicillin binding activity of the protein immunoprecipitated with anti-rPBP2B serum was detected . These results suggest the presence of PBP2B in S . aureus cell membrane that covalently binds penicillin . The internal region of pbpF and PBP2B protein were found in all 12 S . aureus strains tested by PCR and immunoblotting.

Antimicrob Agents Chemother, 1999 Jul, 43(7), 1574 - 7
DNA cleavage activities of Staphylococcus aureus gyrase and topoisomerase IV stimulated by quinolones and 2-pyridones; Saiki AY et al.; We have cloned Staphylococcus aureus DNA gyrase and topoisomerase IV and expressed them in Escherichia coli as polyhistidine-tagged proteins to facilitate purification and eliminate contamination by host enzymes . The enzyme preparations had specific activities similar to previously reported values . Potassium glutamate (K-Glu) stimulated the drug-induced DNA cleavage activity and was optimal between 100 and 200 mM for gyrase and peaked at 100 mM for topoisomerase IV . Higher concentrations of K-Glu inhibited the cleavage activities of both enzymes . Using a common buffer system containing 100 mM K-Glu, we tested the enzyme-mediated DNA cleavage activities of both gyrase and topoisomerase IV with oxolinic acid, norfloxacin, ciprofloxacin, trovafloxacin, clinafloxacin, and the 2-pyridone ABT-719 . As expected, all drugs tested demonstrated greater potency against topoisomerase IV than against gyrase . In addition, cleavage activity was found to correlate well with antibacterial activity.

Schweiz Arch Tierheilkd, 1999, 141(6), 287 - 90
{Resistance situation and enterotoxin production capacity of Staphylococcus aureus strains from bovine mastitis milk samples}; Stephan R et al.; In total, 63 S . aureus strains from mastitis milk samples of different animals in 57 farms were isolated . In 14 (22%) of the S . aureus strains resistancies against one or several of the examined antibiotics could be observed whereby six resistance patterns were found . 14.3% of the strains were penicillin resistant . 34 (54%) of the 63 S . aureus produced enterotoxins (SE) . Three strains formed SEA, 21 SEC, three SED and seven strains 2 SE, SEAC, SEAD or SEBD.

Cardiol Young, 1999 May, 9(3), 280 - 4
Sternal wound and mediastinal infections in infants with congenital heart disease; Kearns B et al.; The objective was to describe the epidemiologic, clinical, bacteriologic and therapeutic features of seven infants who developed sternal wound and mediastinal infections following palliation and/or repair procedures for congenital heart disease . A retrospective chart review was used . All infants with sternal wound and mediastinal infections were < 30 days of age at the initial operative procedure . Six of the infants had hypoplastic left heart syndrome, and one had complete transposition . Two infants required delayed closure of their chest wound . Three infants had superficial sternal infections and presented at a mean of 12 days postoperatively . Four infants had infection of the deep mediastinal structures: they were all asymptomatic and had purulent collections in their mediastinum at their second palliative operation, which was performed at a mean of 120 days after the initial surgery . Staphylococcus aureus, or coagulase-negative Staphylococcus, was isolated from the wound and/or blood of six infants . All infants with mediastinal infections were managed with operative debridement . Infants with superficial infections underwent local debridement . All infants received long-term intravenous antibiotics . Mediastinal infections in infants undergoing palliative staged procedures for congenital heart lesions may be chronic and indolent, resulting in delayed repair of congenital heart lesions.

Microbiol Immunol, 1999, 43(4), 317 - 21
Prophylaxis of local vascular graft infection with levofloxacin incorporated into albumin-sealed dacron graft (LVFX-ALB Graft); Osada T et al.; An animal model was used to assess the efficacy of levofloxacin (LVFX) incorporated into albumin (ALB)-sealed Dacron (LVFX-ALB) graft for the prevention of vascular graft infections caused by Staphylococcus aureus . Under general anesthetic, an interposition graft was placed into dog carotid artery . On completion of the operation, 0.1 ml of normal saline containing 10(7) colony-forming units (CFU) of a slime-producing S . aureus was inoculated directly onto the graft . After 1 day, the samples were sterilely harvested . The antibacterial activity of LVFX into the LVFX-ALB graft was evaluated by colony counting in bacterial cultures and by the fluorescent antibody method staining bacteria adhesion to the grafts . LVFX-ALB grafts had a lower infection rate than the control grafts (1/4, 10(2) CFU vs 4/4, 1.50 x 10(5)+/-1.38 x 10(5)CFU (mean+/-SE)) . In an immunostaining study, LVFX-ALB grafts had small fluorescent areas showing S . aureus adhesion, while fluorescence was observed over the entire surface of the control grafts . Therefore, LVFX-ALB presumably had a bactericidal action and adhesive prevention against inoculated S . aureus . LVFX-ALB may be useful in preventing graft infections during and immediately after vascular reconstruction.

Vet Microbiol, 1999 May, 66(4), 275 - 84
Molecular typing of Staphylococcus aureus of bovine origin by polymorphisms of the coagulase gene; Raimundo O et al.; Mastitis caused by Staphylococcus aureus is a disease of major economic importance to the dairy industry . Transmission occurs during milking, with chronically-infected cows acting as the major reservoirs of infection . PCR-coagulase gene typing of 151 S . aureus isolates from seven farms generated only six PCR types, with 110 (73%) isolates assigned to PCR type 1 and 23 (15.2%) isolates assigned to type 2 . PCR type 1 was the predominant type on five of the seven farms, including farms in geographically separated regions of Victoria, while type 2 predominated on two farms . With the exception of the 41 isolates from one farm, all isolates were resistant to penicillin, but susceptible to other antibiotics that are routinely used to manage mastitis in dairy cattle . Nine of 11 cows with chronic S . aureus infection showed evidence of persistence of a single PCR type for periods of up to 9 months . Two different PCR types of S . aureus were isolated from the other two cows over the same period.

J Immunol, 1999 Jul 1, 163(1), 6 - 10
Cutting edge: trimolecular interaction of TCR with MHC class II and bacterial superantigen shows a similar affinity to MHC:peptide ligands; Redpath S et al.; Bacterial superantigens such as Staphylococcus aureus enterotoxin A (SEA) are very potent stimulators of T cells . They bind to the Vbeta region of the TCR and to MHC class II, stimulating T cells at nanomolar concentrations . Using surface plasmon resonance measurements, we find that binding between the individual components of the complex (TCR-class II, TCR-SEA, SEA-class II) is very weak, but that the stability of the trimolecular complex is considerably enhanced, reaching an affinity similar to that found for TCR interactions with MHC:peptide ligand . Thus, the potency of SEA in stimulation of T cells is not due to particularly strong affinities between the proteins, but to a cooperative effect of interactions in the TCR-SEA-MHC class II trimolecular complex that brings the kinetics into a similar range to binding of conventional Ags . This range may be the optimum for T cell activation.

J Bacteriol, 1999 Jul, 181(13), 3898 - 903
Characterization of the major superoxide dismutase of Staphylococcus aureus and its role in starvation survival, stress resistance, and pathogenicity; Clements MO et al.; A Staphylococcus aureus mutant (SPW1) which is unable to survive long-term starvation was shown to have a transposon insertion within a gene homologous to the sodA family of manganese-dependent superoxide dismutases (SOD) . Whole-cell lysates of the parental 8325-4 strain demonstrated three zones of SOD activity by nondenaturing gel electrophoresis . The activities of two of these zones were dependent on manganese for activity and were absent in SPW1 . The levels of SOD activity and sodA expression were growth-phase dependent, occurring most during postexponential phase . This response was also dependent on the level of aeration of the culture, with highest activity and expression occurring only under high aeration . Expression of sodA and, consequently, SOD activity could be induced by methyl viologen but only during the transition from exponential- to postexponential-phase growth . SPW1 was less able to survive amino acid limitation and acid stress but showed no alteration in pathogenicity in a mouse abscess model of infection compared to the parental strain 8325-4.

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