Staphylococcus aureus

J Hosp Infect, 1999 Feb, 41(2), 133 - 5
Evaluation of tube coagulase and a fluorogenic substrate for rapid detection of methicillin-resistant Staphylococcus aureus from selective enrichment broth in an outbreak of EMRSA 15; Ford M et al.; We investigated the use of tube coagulase and a fluorescent substrate, N-t-BOC-val-pro-arg-7-amido-4-methylcoumarin for the rapid detection of MRSA in selective broth enrichment cultures during an outbreak . These methods were compared with direct plating of swabs and plating a selective broth enrichment culture using 200 screening swabs collected from forty patients during the investigation of an outbreak of E-MRSA 15 . Overall 66 swabs were positive for MRSA following subculture of broth enrichment culture . Direct plating detected 25 (38%) positives, tube coagulase 37 (56%), and fluorescent substrate 49 (74%) respectively, although nine of the 49 turned out to be false reactions . When detection from individual patients was analyzed, selective broth subculture identified 28 patients colonized with MRSA . Direct plating detected only 12 (43%) of these patients . The tube coagulase and fluorescence methods detected MRSA in 17 (60%) and 19 (68%) patients respectively . The tube coagulase method was found to be 100% specific for MRSA suggesting its use as a rapid method for the detection of MRSA from selective enrichment broth.

J Hosp Infect, 1999 Feb, 41(2), 123 - 32
A Norwegian nosocomial outbreak of methicillin-resistant Staphylococcus aureus resistant to fusidic acid and susceptible to other antistaphylococcal agents; Andersen BM et al.; In Norway, infections caused by methicillin resistant Staphylococcus aureus (MRSA) are still uncommon . From December 1993 to January 1997, MRSA was isolated from 22 people in Oslo county; 17 patients and five carriers (healthcare workers) . A cluster of ten people (five patients and five healthcare workers) were associated with an outbreak at two hospitals in Oslo . The five patients were all admitted to the same intensive care unit (ICU) at Ulleval University Hospital between May-July 1995 (they were not transferred from abroad) and treated for acute neurological lesions . After surgery, four of them (one died) were transferred to another hospital for rehabilitation and training . The presence of MRSA was discovered in the patients and the five healthcare workers during the 10 months June 1995-March 1996 . All cluster strains showed an unusual antibiotic resistance pattern in vitro, with a relatively low degree of methicillin resistance, resistance to fusidic acid, but sensitivity to all other anti-staphylococcal agents . A clonal spread of this fusidic acid resistant MRSA was supported by strain typing using pulsed-field gel electrophoresis (PFGE), which showed that all ten cluster strains belonged to one type or its subtype.

Vojnosanit Pregl, 1998 Nov-Dec, 55(6), 611 - 5
{Efficacy of continuous ambulatory peritoneal dialysis in treatment of children with end-stage renal insufficiency}; Sahapozova E et al.; Three children (2 girls and 1 boy) with end-stage renal failure were put in program of continuous ambulatory peritoneal dialysis in the period of 2.5 years (January 1995-September 1997) . The age of the children at the treatment onset was 5-12 years . One of three children died due to cardiovascular failure after six-month treatment . Two out of three children had a total of 8 episodes of peritonitis in the period of 37 months during the treatment with peritoneal dialysis . The incidence of peritonitis occurrence in our patients was one episode in 4 patients/months . Most frequent cause for peritonitis occurrence was Staphylococcus aureus in 50% of isolated bacteria . Obtained results in peritoneal equilibration test revealed that the transport and ultrafiltration rate of peritoneal membrane decreased after recurrent peritonitis episodes.

J Antimicrob Chemother, 1998 Dec, 42(6), 807 - 10
The effect of reserpine, an inhibitor of multidrug efflux pumps, on the in-vitro activities of ciprofloxacin, sparfloxacin and moxifloxacin against clinical isolates of Staphylococcus aureus; Schmitz FJ et al.; In Staphylococcus aureus, in addition to mutations in the grl and gyr gene loci, multidrug efflux pumps like NorA contribute to decreased fluoroquinolone susceptibility . Efflux pumps can be inhibited by the plant alkaloid reserpine, which, at 20 mg/L, reduced sparfloxacin, moxifloxacin and ciprofloxacin IC50s and MICs by up to four-fold in 11, 21 and 48 of the 102 unrelated clinical isolates tested, respectively . The effect was less pronounced with the hydrophobic drugs sparfloxacin and moxifloxacin than with the hydrophilic drug ciprofloxacin and was stable in all 25 clonally related isolates tested.

J Orthop Trauma, 1999 Feb, 13(2), 102 - 6
Efficacy of gentamycin-impregnated resorbable hydroxyapatite cement in treating osteomyelitis in a rat model; Solberg BD et al.; OBJECTIVE: To test the effectiveness of a self-setting hydroxyapatite cement (HAC) as a carrier of gentamycin for the treatment of chronic osteomyelitis in a rat model by using a void-fill placement technique . DESIGN: Osteomyelitis of the tibia was created with Staphylococcus aureus (ATCC 49230) in sixty retired female breeder Sprague-Dawley rats by using the model by Korkusuz et al . (J Bone Joint Surg 1993;75B:111-114) . At seven weeks after infection, all animals demonstrated clinical and radiographic signs of osteomyelitis and were debrided and divided into four treatment groups: A, debridement only; B, debridement and daily intraperitoneal gentamycin (0.2 milligram per kilogram per day); C, debridement and gentamycin-impregnated HAC in a void-fill model (1.0 milligram per kilogram of gentamycin); and D, debridement and gentamycin-impregnated polymethylmethacrylate (PMMA) beads (1.0 milligram per kilogram of gentamycin) . Tibiae were harvested at zero weeks (control, n = 6), three weeks (n = 3 per group), five weeks (n = 4 per group), and seven weeks (n = 4 per group) and analyzed with quantitative bacteriologic analysis . OUTCOME MEASUREMENT: Qualitative bacteriologic analysis was performed by using serial dilution plating of homogenized tissue samples on standard soy trypticase agar plates . Reexamination by phage typing was performed to exclude contamination . RESULTS: The quantitative counts for Groups C (HAC) and D (PMMA) were significantly less (p < 0.003) than those for Group A (debridement alone) or Group B (intraperitoneal gentamycin) at all time points after time zero . There was no difference between Groups C and D at any time point . CONCLUSION: HAC is an effective adjuvant in treating chronic osteomyelitis in a rat model when using a void-fill placement technique.

J Orthop Trauma, 1999 Feb, 13(2), 98 - 101
Use of a tobramycin-impregnated polymethylmethacrylate pin sleeve for the prevention of pin-tract infection in goats; Voos K et al.; OBJECTIVE: To test the hypothesis that antibiotic-laden polymethylmethacrylate (PMMA) pin sleeves prevent infection around skeletal external fixation pins . DESIGN: An experimental study using an animal model was conducted . ANIMALS: In each of five goats, three four-millimeter half-pins were placed in the left and right iliac crests, for a total of thirty half-pins . The pins were infected with one milliliter of broth containing 7.6 x 10(5) colony-forming units per milliliter of Staphylococcus aureus (ATCC 25923) . INTERVENTION: The pins in the right iliac crest were treated with the tobramycin-impregnated pin sleeves, and the pins in the left iliac crest (control) were left untreated . RESULTS: The results showed clinical evidence of infection (i.e., looseness and gross pus) and heavy bacterial growth (average 6.8 x 10(10) colony-forming units per milliliter) for the untreated pins, but no clinical evidence of infection and no bacterial growth at forty-eight hours for the treated pins . CONCLUSION: The present results indicate that the use of the antibiotic-impregnated PMMA pin sleeve can prevent the development of pin-tract infection and appears to prevent colonization of the external fixation pins.

APMIS, 1998 Dec, 106(12), 1157 - 64
Secretion of IL-6, IL-8 and G-CSF by human endothelial cells in vitro in response to Staphylococcus aureus and staphylococcal exotoxins; Soderquist B et al.; The capacity of endothelial cells to produce and release cytokines (IL-6, IL-8 and G-CSF) in response to exposure to Staphylococcus aureus strains or staphylococcal exotoxins (alpha-toxin, enterotoxin A and TSST-1) was investigated . An endothelial cell culture model of human umbilical vein endothelial cells (HUVEC) was used . Five out of ten clinical isolates of S . aureus were found to induce cytokine production and release from endothelial cells . Four of the five isolates that induce cytokine release produced enterotoxin A, B, C, D and/or TSST-1, compared with two of those that did not induce release . Purified staphylococcal exotoxins (1 pg/ml-1 microg/ml) did not act as primary stimuli and induced no detectable cytokine secretion . When endothelial cells were prestimulated with IL-1beta or TNF alpha at a concentration of 1 ng/ml for 2 h, IL-1beta served as a potent primary stimulus for IL-6, IL-8 and G-CSF production, whereas TNF alpha did not induce any significant cytokine release during the subsequent 24 h . A further increase in IL-6 and G-CSF release, but not of IL-8, was observed when IL-1beta prestimulated cells were exposed to alpha-toxin or TSST-1 . However, to potentiate cytokine production (IL-6 and IL-8) by SEA, both IL-1beta and the toxin had to be present simultaneously . Our data show that S . aureus, but not staphylococcal exotoxins, have the capacity to act as primary stimuli of endothelial cells and induce production and release of cytokines . IL-1beta may prime HUVEC to release IL-6, IL-8 and G-CSF prior to subsequent stimulation with staphylococcal exotoxins.

Eur J Clin Microbiol Infect Dis, 1998 Dec, 17(12), 877 - 9
High-level mupirocin resistance among Spanish methicillin-resistant Staphylococcus aureus; Alarcon T et al.; Twelve strains of methicillin-resistant Staphylococcus aureus with high-level resistance to mupirocin were studied . The MIC of methicillin was 16 to 128 mg/l and the MIC of mupirocin > or = 512 mg/l . All of the isolates carried a plasmid of about 30 MDa, and one strain lost resistance to mupirocin when the plasmid was cured . Three different resistance patterns were found: six strains were resistant to ciprofloxacin, kanamycin, and 10 mg/l of cadmium sulfate; two strains were resistant to these agents as well as to gentamicin, erythromycin, clindamycin, mercury chloride, and ethidium bromide; and four strains were resistant to the previously named agents as well as to rifampicin and tetracycline . The use of this valuable topical antibiotic, especially in long-term-care facilities, should be monitored to avoid dissemination of resistance.

Proc Natl Acad Sci U S A, 1999 Mar 2, 96(5), 2279 - 84
Crossreactive recognition of viral, self, and bacterial peptide ligands by human class I-restricted cytotoxic T lymphocyte clonotypes: implications for molecular mimicry in autoimmune disease; Misko IS et al.; The immunodominant, CD8(+) cytotoxic T lymphocyte (CTL) response to the HLA-B8-restricted peptide, RAKFKQLL, located in the Epstein-Barr virus immediate-early antigen, BZLF1, is characterized by a diverse T cell receptor (TCR) repertoire . Here, we show that this diversity can be partitioned on the basis of crossreactive cytotoxicity patterns involving the recognition of a self peptide-RSKFRQIV-located in a serine/threonine kinase and a bacterial peptide-RRKYKQII-located in Staphylococcus aureus replication initiation protein . Thus CTL clones that recognized the viral, self, and bacterial peptides expressed a highly restricted alphabeta TCR phenotype . The CTL clones that recognized viral and self peptides were more oligoclonal, whereas clones that strictly recognized the viral peptide displayed a diverse TCR profile . Interestingly, the self and bacterial peptides equally were substantially less effective than the cognate viral peptide in sensitizing target cell lysis, and also resulted only in a weak reactivation of memory CTLs in limiting dilution assays, whereas the cognate peptide was highly immunogenic . The described crossreactions show that human antiviral, CD8(+) CTL responses can be shaped by peptide ligands derived from autoantigens and environmental bacterial antigens, thereby providing a firm structural basis for molecular mimicry involving class I-restricted CTLs in the pathogenesis of autoimmune disease.

Int J Food Microbiol, 1999 Jan 12, 46(1), 45 - 55
A mathematical model for bacterial inactivation; Xiong R et al.; The first order kinetic model, the Buchanan model and Cerf's model, can model a linear survival curve, a survival curve with a shoulder and a survival curve with a tailing, respectively . However, they are not suitable for fitting a sigmoidal survival curve . The three models were integrated into a new model that was capable of fitting the four most commonly observed survival curves: linear curves, curves with a shoulder, curves with a tailing (biphasic curves) and sigmoidal curves . The new model was compared with the Whiting-Buchanan model using the survival curves of Staphylococcus aureus . The goodness-of-fit of the proposed model is practically as good as that of the Whiting-Buchanan model . Compared with the Whiting-Buchanan model, the proposed model has a more mechanistic background . Since for non-linear survival curves, such as biphasic and sigmoidal curves, the t(m-D) value (the time required for an m-log-cycle reduction of microorganisms under a given condition) cannot be estimated accurately by the existing or traditional method, a new method is also proposed to predict accurately the t(m-D) value for non-linear survival curves.

Ann Intern Med, 1999 Feb 2, 130(3), 221 - 5
Nasal carriage of and infection with Staphylococcus aureus in HIV-infected patients; Nguyen MH et al.; BACKGROUND: Staphylococcus aureus is a common cause of serious infection in patients infected with HIV . OBJECTIVES: To evaluate risk factors for and quantitative effect of S . aureus infection in HIV-infected patients, with special attention to nasal carriage . DESIGN: Prospective, multihospital cohort study . SETTING: Three tertiary care Veterans Affairs Medical Centers . PARTICIPANTS: 231 ambulatory HIV-infected patients . RESULTS: Thirty-four percent of patients were nasal carriers of S . aureus . Of these patients, 38% were persistent carriers and 62% were intermittent carriers . Twenty-one episodes of infection occurred in 13 patients: Ten were bacteremias (including 2 cases of endocarditis), 1 was pneumonia, and 10 were cutaneous or subcutaneous infections . Seventeen (85%) of these episodes occurred in patients with CD4 counts less than 100 cells/mm3 . Recurrent infections occurred in 3 of 7 patients who survived an initial S . aureus infection . The mortality rate was higher among patients with S . aureus infection than among those without infection (P = 0.03) . Factors significantly associated with S . aureus infection were nasal carriage, presence of a vascular catheter, low CD4 count, and neutropenia . Molecular strain typing indicated that for 6 of 7 infected patients, the strain of S . aureus isolated from the infected sites was the same as that previously cultured from the nares . CONCLUSION: Nasal carriage is an important risk factor for S . aureus infection in HIV-infected patients . Controlled studies are indicated to determine whether eradication of nasal carriage in a selected subset of patients (for example, those with a low CD4 cell count) might prevent invasive S . aureus infection in patients with HIV infection.

Biophys J, 1999 Mar, 76(3), 1469 - 79
Localization and environment of tryptophans in soluble and membrane-bound states of a pore-forming toxin from Staphylococcus aureus; Raja SM et al.; The location and environment of tryptophans in the soluble and membrane-bound forms of Staphylococcus aureus alpha-toxin were monitored using intrinsic tryptophan fluorescence . Fluorescence quenching of the toxin monomer in solution indicated varying degrees of tryptophan burial within the protein interior . N-Bromosuccinimide readily abolished 80% of the fluorescence in solution . The residual fluorescence of the modified toxin showed a blue-shifted emission maximum, a longer fluorescence lifetime as compared to the unmodified and membrane-bound alpha-toxin, and a 5- to 6-nm red edge excitation shift, all indicating a restricted tryptophan environment and deeply buried tryptophans . In the membrane-bound form, the fluorescence of alpha-toxin was quenched by iodide, indicating a conformational change leading to exposure of some tryptophans . A shorter average lifetime of tryptophans in the membrane-bound alpha-toxin as compared to the native toxin supported the conclusions based on iodide quenching of the membrane-bound toxin . Fluorescence quenching of membrane-bound alpha-toxin using brominated and spin-labeled fatty acids showed no quenching of fluorescence using brominated lipids . However, significant quenching was observed using 5- and 12-doxyl stearic acids . An average depth calculation using the parallax method indicated that the doxyl-quenchable tryptophans are located at an average depth of 10 A from the center of the bilayer close to the membrane interface . This was found to be in striking agreement with the recently described structure of the membrane-bound form of alpha-toxin.

Antimicrob Agents Chemother, 1999 Mar, 43(3), 717 - 21
Evaluation of bactericidal activities of LY333328, vancomycin, teicoplanin, ampicillin-sulbactam, trovafloxacin, and RP59500 alone or in combination with rifampin or gentamicin against different strains of vancomycin-intermediate Staphylococcus aureus by time-kill curve methods; Hershberger E et al.; This in vitro study evaluated the activities of vancomycin, LY333328, and teicoplanin alone and in combination with gentamicin, rifampin, and RP59500 against Staphylococcus aureus isolates with intermediate susceptibilities to vancomycin . Ampicillin-sulbactam and trovafloxacin were also evaluated . LY333328 and ampicillin-sulbactam resulted in bactericidal activity against all isolates . The combination of gentamicin with glycopeptides showed synergistic activity, while rifampin had no added benefit.

Antimicrob Agents Chemother, 1999 Mar, 43(3), 667 - 71
Comparison of efficacies of oral levofloxacin and oral ciprofloxacin in a rabbit model of a staphylococcal abscess; Fernandez J et al.; Oral levofloxacin was compared to oral ciprofloxacin in a Staphylococcus aureus subcutaneous abscess model in rabbits . Rabbits were surgically prepared with subcutaneous wiffle balls (43 mm in diameter) and allowed to recover for 4 to 6 weeks . Rabbits were infected by direct injection into the capsule with S . aureus ATCC 29213 (5 x 10(5) CFU) and were allowed to remain infected for 8 days before the initiation of anti-infective treatment . Efficacy was determined by assessing the bacterial load within the capsule over a 10-day treatment period . In single-dose pharmacokinetic studies in infected rabbits, similar area under the concentration-time curve/MIC ratios were obtained in the plasma and abscess fluid for levofloxacin at 45 mg/kg of body weight and ciprofloxacin at 200 mg/kg of body weight . Similar efficacies were seen with levofloxacin at 45 mg/kg/day and ciprofloxacin 400 mg/kg/day by day 10 . In this model, levofloxacin was significantly more efficacious than ciprofloxacin (P < 0.01).

Antimicrob Agents Chemother, 1999 Mar, 43(3), 498 - 502
Prediction of the effects of inoculum size on the antimicrobial action of trovafloxacin and ciprofloxacin against Staphylococcus aureus and Escherichia coli in an in vitro dynamic model; Firsov AA et al.; The effect of inoculum size (N0) on antimicrobial action has not been extensively studied in in vitro dynamic models . To investigate this effect and its predictability, killing and regrowth kinetics of Staphylococcus aureus and Escherichia coli exposed to monoexponentially decreasing concentrations of trovafloxacin (as a single dose) and ciprofloxacin (two doses at a 12-h interval) were compared at N0 = 10(6) and 10(9) CFU/ml (S . aureus) and at N0 = 10(6), 10(7), and 10(9) CFU/ml (E . coli) . A series of pharmacokinetic profiles of trovafloxacin and ciprofloxacin with respective half-lives of 9.2 and 4 h were simulated at different ratios of area under the concentration-time curve (AUC) to MIC (in {micrograms x hours/milliliter}/{micrograms/milliliter}): 58 to 466 with trovafloxacin and 116 to 932 with ciprofloxacin for S . aureus and 58 to 233 and 116 to 466 for E . coli, respectively . Although the effect of N0 was more pronounced for E . coli than for S . aureus, only a minor increase in minimum numbers of surviving bacteria and an almost negligible delay in their regrowth were associated with an increase of the N0 for both organisms . The N0-induced reductions of the intensity of the antimicrobial effect (IE, area between control growth and the killing-regrowth curves) were also relatively small . However, the N0 effect could not be eliminated either by simple shifting of the time-kill curves obtained at higher N0s by the difference between the higher and lowest N0 or by operating with IEs determined within the N0-adopted upper limits of bacterial numbers (IE's) . By using multivariate correlation and regression analyses, linear relationships between IE and log AUC/MIC and log N0 related to the respective mean values {(log AUC/MIC)average and (log N0)average} were established for both trovafloxacin and ciprofloxacin against each of the strains (r2 = 0.97 to 0.99) . The antimicrobial effect may be accurately predicted at a given AUC/MIC of trovafloxacin or ciprofloxacin and at a given N0 based on the relationship IE = a + b {(log AUC/MIC)/(log AUC/MIC)average} - c {(log N0)/(log N0)average} . Moreover, the relative impacts of AUC/MIC and N0 on IE may be evaluated . Since the c/b ratios for trovafloxacin and ciprofloxacin against E . coli were much lower (0.3 to 0.4) than that for ampicillin-sulbactam as examined previously (1.9), the inoculum effect with the quinolones may be much less pronounced than with the beta-lactams . The described approach to the analysis of the inoculum effect in in vitro dynamic models might be useful in studies with other antibiotic classes.

J Antibiot (Tokyo), 1998 Dec, 51(12), 1087 - 92
Diperamycin, a new antimicrobial antibiotic produced by Streptomyces griseoaurantiacus MK393-AF2 . I . Taxonomy, fermentation, isolation, physico-chemical properties and biological activities; Matsumoto N et al.; Antibacterial antibiotics, diperamycin (1) was produced in the culture broth of Streptomyces griseoaurantiacus MK393-AF2 . Various spectroscopic analyses of 1 suggested that 1 belonged to a member of cyclic hexadepsipeptide antibiotic . Antibiotic 1 had potent inhibitory activity against various Gram-positive bacteria including Enterococcus seriolicida and methicillin-resistant Staphylococcus aureus.

J Ocul Pharmacol Ther, 1999 Feb, 15(1), 91 - 6
High dose intramuscular methylprednisolone in experimental Staphylococcus aureus endophthalmitis; Yoshizumi MO et al.; We attempted to determine whether treatment using intramuscular methylprednisolone plus intravitreal vancomycin decreased ocular inflammation and preserved retinal function better in experimental Staphylococcus aureus (S . aureus) endophthalmitis than treatment with intravitreal vancomycin alone . Sixteen rabbits received intravitreal inoculations in both eyes with S . aureus and the rabbits were divided into two groups (group I and group II) of eight rabbits each . Group I rabbits were treated with one injection of intravitreal vancomycin in each eye at either 24, 36, 48 or 72 hours after bacterial inoculation followed by seven consecutive days of high dose intramuscular methylprednisolone (30 mg/kg per day) . Group II rabbits were treated with only one intravitreal injection of vancomycin in each eye at equivalent time intervals as in Group I . Clinical evaluations of ocular inflammation were performed by slit-lamp biomicroscopy and indirect ophthalmoscopy . Electroretinography (ERG) was performed eight days after bacterial inoculation to assess retinal function in all eyes . The combination of intramuscular methylprednisolone and intravitreal vancomycin resulted in a degree of ocular inflammation equal to eyes treated with intravitreal vancomycin alone at all treatment intervals . ERG responses were not significantly different in either group . A single intravitreal injection of vancomycin plus daily intramuscular methylprednisolone for seven days were found neither to decrease ocular inflammation nor preserve retinal function better than a single intravitreal injection of vancomycin in our experimental model of S . aureus endophthalmitis.

Dermatol Surg, 1999 Feb, 25(2), 89 - 93
The evaluation of a cadexomer iodine wound dressing on methicillin resistant Staphylococcus aureus (MRSA) in acute wounds; Mertz PM et al.; BACKGROUND: Many bacteria have become resistant to commonly-used antibiotics . OBJECTIVE: The purpose of this study was to examine the effect of a cadexomer iodine wound dressing on methicillin resistant Staphylococcus aureus (MRSA) . METHOD: Partial thickness wounds were made on the backs of three pigs and inoculated with a known amount of MRSA . Wounds were treated with either cadexomer iodine dressing or vehicle dressing (without iodine), or they were left untreated . Three wounds from each treatment group per animal were cultured using quantitative scrub techniques after 24, 48, or 72 hours of treatment . CONCLUSIONS: The cadexomer iodine dressing significantly reduced MRSA and total bacteria in the wounds as compared to both the no treatment control and vehicle . No significant differences were observed in the number of bacteria recovered between the no treatment control and cadexomer (vehicle) treated wounds . Cadexomer iodine may be an effective agent for preventing proliferation of MRSA in wounds.

Microbiol Immunol, 1998, 42(12), 829 - 36
New evidence that the Tyr-157 and Tyr-159 residues of staphylococcal exfoliative toxin B are essential for its toxicity; Sakurai S et al.; To determine the active site of exfoliative toxin B (sETB) of Staphylococcus aureus, the etb gene was cloned from an S . aureus SU strain obtained from a patient with impetigo . We prepared a frame shift mutant protein from a recombinant plasmid with a BglII linker inserted into the Tyr-155 codon of the ETB gene (pETB/BglIIL) . The recombinant mutant protein (ETB/BglIIL) obtained from Escherichia coli containing pETB/BgIIIL showed no toxicity in neonatal mice and no agglutination activity . The 20-kDa ETB/BglIIL contained 185 amino acid residues . Site-directed mutagenesis was used to introduce mutations at either Tyr-155, Tyr-157, Tyr-159, or Tyr-162 . Substitution of any of the Tyr residues decreased exfoliative activity compared with that of native sETB (4,000 EU/ml) . Substitution of Tyr-155 with a Phe (ETBYN155) decreased activity 5-fold (800 EU/ml) . Substitution of Tyr-157 with Leu (ETB/Y157) decreased activity 80-fold (50 EU/ml) and decreased agglutination titer 5-fold compared with that of native sETB (400,000) . Substitution of Tyr-159 with Leu (ETB/Y159)decreased activity 4-fold (1,000 EU/ml) . When both Tyr-157 and Tyr-159 were mutated (ETB/Y157-159), both toxicity and antigenicity were completely lost . On an immunodiffusion test, ETBNY157 showed a faint precipitation line, but ETB/BglIIL and ETB/Y157-159 had no activity, showing that the Tyr-157 and Tyr-159 residues are essential for the toxicity and antigenicity of ETB.

Kyobu Geka, 1999 Feb, 52(2), 163 - 7
{Curative report of two cases with MRSA mediastinitis after cardiovascular surgery, treated by new irrigation technique (intermittent mass-irrigation technique)}; Matsumura G et al.; We experienced a 42-year-old patient who underwent aortic valve replacement and a 63-year-old patient who underwent coronary artery bypass grafting with mediastinitis caused by methicillin-resistant Staphylococcus aureus (MRSA) . They were successfully treated with the intermittent mass-irrigation technique . The irrigation device consistent of a irrigation tube which placed in upper half of mediastinum and three suction tubes which placed in lower half . We dripped the wash composed of 0.03-0.05% of Povidone-Iodine with 1,000 ml of physiological saline, for 3 to 5 times a day by condition . After each wash, we cross clamped the drainage tubes and filled mediastinum with 0.5 grams of vancomycin hydrochloride dissolved in 100 ml of physiological saline, dripped from irrigation tube, for 30 minutes . After 9-day irrigation in the former case and 16-day irrigation in the latter case, the culture of drainage turned negative . We presumed that this new method is effective for mediastinitis after cardiovascular surgery.

Trends Microbiol, 1998 Dec, 6(12), 484 - 8
Surface protein adhesins of Staphylococcus aureus; Foster TJ et al.; Staphylococcus aureus can colonize the host to initiate infection by adhering to components of the extracellular matrix . Adherence is mediated by surface protein adhesins (MSCRAMMs) . Ligand binding by these fibronectin-, fibrinogen- and collagen-binding proteins occurs by distinct mechanisms that are being investigated at the molecular level.

Rinsho Biseibutshu Jinsoku Shindan Kenkyukai Shi, 1998 Nov 25, 9(1), 27 - 32
Studies on Methicillin-Resistant Staphylococcus aureus Bacteremia Due to Laboratory Medical Analysis; Furuta I I et al.; We encountered 64 patients with methicillin-resistant Staphylococcus aureus (MRSA) bacteremia between April 1993 and March 1994 . Mean patient age was 54 years . There were 46 males and 18 females . Underlying diseases mainly consisted of traffic accident (10 patients), valvular heart disease (5 patients), chronic renal failure (5 patients), leukemia (5 patients), pneumonia (3 patients), and malignant lymphoma (3 patients) . The common clinical laboratory findings of MRSA bacteremia included decreses in total protein, albumin and hemoglobin as well as increases in white blood cells (neutrophils) and C reactive protein . In particular, an increase in C reactive protein by 10 mg/dl or more may be useful for diagnosing bacteremia . Laboratory findings were compared between surviving and non-surviving patients . There were significant differences in albumin, cholesterol, bilirubin, creatinine, and CRP . In 18 patients (28.1%), bacteremia was caused by infection due to contamination of central venous catheters . Since medical treatment with intra-vascular devices may cause bacteremia, sufficient caution is needed.

Epidemiol Infect, 1998 Dec, 121(3), 507 - 14
Epidemiological characterization of methicillin-resistant Staphylococcus aureus isolated in the North West of England by protein A (spa) and coagulase (coa) gene polymorphisms; Walker J et al.; In a comparative study, isolates of methicillin-resistant Staphylococcus aureus (MRSA) with known pulsed-field gel electrophoresis (PFGE) and bacteriophage type were analysed by polymerase chain reaction (PCR) and restriction fragment length polymorphisms (RFLP) for additional discriminatory subtyping information . PFGE was previously performed using standardized, commercially available kits and pre-programmed software . Isolates were examined for coagulase (coa) and protein A (spa) gene polymorphisms following PCR amplification of the coa hypervariable and spa repeat regions . Coa gene RFLPs produced a total of 38 distinct combined patterns after digestion with HaeIII and AluI and identified the predominant epidemic (EMRSA) types 15 and 16 . A unique HaeIII restriction site was identified by RFLP and sequence analysis in the coa gene for EMRSA 15 but not EMRSA 16 . The spa gene PCR yielded a total of 14 different profiles ranging from 3-18 repeats with the 2 predominant EMRSA types falling into 2 distinct groups . PCR detection of coa and spa polymorphisms offer a rapid preliminary strain identification and discriminatory subtyping information for surveillance of MRSA.

J Food Prot, 1999 Feb, 62(2), 194 - 7
Fate of gram-positive bacteria in reconditioned, pork-processing plant water; Palumbo SA et al.; This study investigated the responses of Enterococcus faecium (ATCC 19433), Staphylococcus aureus (196E), and Listeria monocytogenes Scott A in water from a local meat-processing plant . Each bacterium was added to a starting count of 3 log10 CFU/ml and held from 5 to 28 degrees C . At intervals (0, 2, 7, 14, and 21 days), aliquots were plated on appropriate selective agars . In contrast to the gram-negative bacteria studied previously and which grew, the three gram-positive bacteria survived with some slight increase in number in only nonchlorinated, reconditioned water, either filtered (0.22 microm pore size) or nonfiltered . The presence of chlorine in either potable or reconditioned water contributed to the rapid decline in viable counts for all three bacteria . These results further emphasize the importance of residual chlorine in preventing the growth of these gram-positive bacteria in potable and reconditioned waters.

Biomaterials, 1999 Feb, 20(3), 229 - 32
Resistance of antibiotic-bonded gelatin-coated polymer meshes to Staphylococcus aureus in a rabbit subcutaneous pouch model; Goeau-Brissonniere O et al.; This study examines the efficacy of the bonding of rifampicin, vancomycin or gentamicin to gelatin-coated knitted polymer meshes to prevent perioperative infection . Antibiotic bonding was obtained by soaking the meshes for 15 min in a solution containing 20 mg ml(-1) of rifampicin or 10 mg ml(-1) of vancomycin or gentamicin . A polymer mesh was implanted in a subcutaneous pouch in 16 rabbits: four received a rifampicin-soaked mesh, four received a vancomycin-soaked mesh, four received a gentamicin-soaked mesh, and four received an untreated mesh (control group) . At the time of implantation, all the meshes were contaminated locally with 10(8) colony forming units of Staphylococcus aureus . Meshes were harvested one week later and submitted to bacterial counts . At the time of explantation, none of the antibiotic-soaked meshes were infected, whereas all the untreated meshes were infected . These results show that antibiotic soaking evidently prevents perioperative infection of gelatin-coated knitted polymer meshes in this model.

Clin Infect Dis, 1999 Jan, 28(1), 106 - 14
Infective endocarditis due to Staphylococcus aureus: 59 prospectively identified cases with follow-up; Fowler VG Jr et al.; Fifty-nine consecutive patients with definite Staphylococcus aureus infective endocarditis (IE) by the Duke criteria were prospectively identified at our hospital over a 3-year period . Twenty-seven (45.8%) of the 59 patients had hospital-acquired S . aureus bacteremia . The presumed source of infection was an intravascular device in 50.8% of patients . Transthoracic echocardiography (TTE) revealed evidence of IE in 20 patients (33.9%), whereas transesophageal echocardiography (TEE) revealed evidence of IE in 48 patients (81.4%) . The outcome for patients was strongly associated with echocardiographic findings: 13 (68.4%) of 19 patients with vegetations visualized by TTE had an embolic event or died of their infection vs . five (16.7%) of 30 patients whose vegetations were visualized only by TEE (P < .01) . Most patients with S . aureus IE developed their infection as a consequence of a nosocomial or intravascular device-related infection . TEE established the diagnosis of S . aureus IE in many instances when TTE was nondiagnostic . Visualization of vegetations by TTE may provide prognostic information for patients with S . aureus IE.

Ned Tijdschr Geneeskd, 1998 Nov 28, 142(48), 2630 - 3
{The spread of a 'Dutch' methicillin-resistant Staphylococcus aureus strain}; Schneeberger PM et al.; Following isolation of a methicillin-resistant Staphylococcus aureus (MRSA) in a patient subjected to amputation below the knee because of a vasculopathy, further investigations were carried out . Nose, throat and wound cultures were taken from staff and patients who had had contact with the index patient . After taking inventory cultures and cleansing of the two wards involved, these wards were quarantined . The bacterial strain was characterized using microbiological standard methods . The MRSA was encountered in a total of nine patients and two nurses . An infection due to this MRSA was found in two patients and one nurse . Eradication in the hospital was successful . MRSA with the same phage type was found in one nurse and one patient in two nearly hospitals and in one patient in a nearby city . Anamnestically, there had been no contact between them . Tracing this sort of outbreak in time is not possible with the current preventive MRSA policy because there are no demonstrable risk groups for a MRSA occurring in the Netherlands . Routine checking for MRSA carriership among nursing personnel and long-staying surgical patients is a possibility to detect spread of this MRSA . It appears advisable to take restrictive measures even against this S . aureus with restricted resistance, because neither penicillins nor cephalosporins are efficacious . In general, more attention should be given to prevention of nosocomial transmission of S . aureus.

Infection, 1999 Jan-Feb, 27(1), 28 - 33
Subverting bacterial resistance using high dose, low solubility antibiotics in fibrin; Woolverton CJ et al.; Antibiotics (ABs) delivered from fibrin were evaluated for control of multi-drug resistant (MDR) Staphylococcus aureus . ABs having low aqueous solubility (< or = 1 mg/ml) were encapsulated by fibrin (composed of fibrinogen, thrombin, Factor XIIIa and calcium chloride) and examined . Electron microscopy revealed fibrin-caged, tetracycline crystals that were 0.26 to 2.8 microns in size and bound within the reticular matrix . Antibiograms documented that S . aureus ATCC 27659 was resistant to erythromycin (ERY), penicillin G (PEN), streptomycin (STR), sulfamethoxazole-trimethoprim (SXT) and tetracycline (TET) . However, low solubility formulations of STR (10 mg/ml) or SXT (0.5 mg/ml), delivered from fibrin and evaluated by the agar disk diffusion assay, produced zones of growth inhibition after 18-24 h at 37 degrees C in vitro, indicating renewed susceptibility of S . aureus ATCC 27659 to these ABs . ERY, PEN and TET were unable to overcome resistance at concentrations up to 10 mg/ml . In vivo, intraperitoneal (i.p.) injection of 150 mg/kg STR delivered from fibrin resulted in 100% survival of rats with MDR S . aureus peritonitis as compared with control rats receiving i.p . STR (150 mg/kg) in 0.9% saline . The results demonstrate that some low solubility ABs delivered from fibrin are efficacious in controlling infection mediated by MDR S . aureus.

Infect Immun, 1999 Mar, 67(3), 1331 - 7
Hyperproduction of alpha-hemolysin in a sigB mutant is associated with elevated SarA expression in Staphylococcus aureus; Cheung AL et al.; To evaluate the role of SigB in modulating the expression of virulence determinants in Staphylococcus aureus, we constructed a sigB mutant of RN6390, a prototypic S . aureus strain . The mutation in the sigB gene was confirmed by the absence of the SigB protein in the mutant on an immunoblot as well as the failure of the mutant to activate sigmaB-dependent promoters (e.g., the sarC promoter) of S . aureus . Phenotypic analysis indicated that both alpha-hemolysin level and fibrinogen-binding capacity were up-regulated in the mutant strain compared with the parental strain . The increase in fibrinogen-binding capacity correlated with enhanced expression of clumping factor and coagulase on immunoblots . The effect of the sigB mutation on the enhanced expression of the alpha-hemolysin gene (hla) was primarily transcriptional . Upon complementation with a plasmid containing the sigB gene, hla expression returned to near parental levels in the mutant . Detailed immunoblot analysis as well as a competitive enzyme-linked immunosorbent assay of the cell extract of the sigB mutant with anti-SarA monoclonal antibody 1D1 revealed that the expression of SarA was higher in the mutant than in the parental control . Despite an elevated SarA level, the transcription of RNAII and RNAIII of the agr locus remained unaltered in the sigB mutant . Because of a lack of perturbation in agr, we hypothesize that inactivation of sigB leads to increased expression of SarA which, in turn, modulates target genes via an agr-independent but SarA-dependent pathway.

Infect Immun, 1999 Mar, 67(3), 1045 - 9
Alpha-toxin and gamma-toxin jointly promote Staphylococcus aureus virulence in murine septic arthritis; Nilsson IM et al.; Septic arthritis is a common and feared complication of staphylococcal infections . Staphylococcus aureus produces a number of potential virulence factors including certain adhesins and enterotoxins . In this study we have assessed the roles of cytolytic toxins in the development of septic arthritis by inoculating mice with S . aureus wild-type strain 8325-4 or isogenic mutants differing in the expression of alpha-, beta-, and gamma-toxin production patterns . Mice inoculated with either an alpha- or beta-toxin mutant showed degrees of inflammation, joint damage, and weight decrease similar to wild-type-inoculated mice . In contrast, mice inoculated with either double (alpha- and gamma-toxin-deficient)- or triple (alpha-, beta-, and gamma-toxin-deficient)-mutant S . aureus strains showed lower frequency and severity of arthritis, measured both clinically and histologically, than mice inoculated with the wild-type strain . We conclude that simultaneous production of alpha- and gamma-toxin is a virulence factor in S . aureus arthritis.

Am J Gastroenterol, 1999 Feb, 94(2), 391 - 7
A reassessment of splenic hypofunction in celiac disease; Corazza GR et al.; OBJECTIVES: Because there is controversy regarding the prevalence, familial occurrence, and possible factors inducing splenic hypofunction in celiac disease, we have reassessed them in a large series of untreated patients and their first-degree relatives . METHODS: Pitted red cell counting was used to measure splenic function and the effect that age at diagnosis has on it, while severity of intestinal lesions and nutritional status were estimated by multiple linear regression analysis . Moreover, serum tuftsin activity was assayed by measuring its ability to stimulate phagocytosis of opsonized Staphylococcus aureus . RESULTS: We found that 32.8% of untreated celiacs and none of their relatives had pitted red cell values in the range of splenic hypofunction (>4%) . Only age at diagnosis, but not the other two covariates, was significantly associated with the degree of splenic hypofunction . Tuftsin activity was depressed in celiac disease and this reduction was significantly greater in hyposplenic patients . CONCLUSIONS: In celiac disease the prevalence of splenic hypofunction is lower than formerly believed . The duration of preexposure to gluten is a crucial factor for the prevalence and severity of this complication that does not affect celiac relatives . In celiac disease splenic hypofunction is accompanied by a reduced phagocyte activity linked to the decreased release of tuftsin.

J Immunol Methods, 1999 Jan 1, 222(1-2), 171 - 82
General expression vectors for production of hydrophobically tagged immunogens for direct iscom incorporation; Andersson C et al.; A new general strategy for the production of recombinant protein immunogens has been investigated . The rationale involves the production of a recombinant immunogen as fused to a composite tag comprising one domain suitable for affinity purification and a hydrophobic tag designed for direct incorporation through hydrophobic interaction of the affinity-purified immunogen into an adjuvant system, in this case immunostimulating complexes (iscoms) . Three different hydrophobic tags were evaluated: (i) a tag denoted IW containing stretches of hydrophobic isoleucine (I) and tryptophan (W) residues; (ii) a tag denoted MI consisting of the transmembrane region of hemagglutinin from influenza A virus; and (iii) a tag denoted PD designed to be pH-dependent in such a way that an amphiphatic alpha-helix would be formed at low pH . As an affinity tag, an IgG-binding domain Z derived from Staphylococcus aureus protein A (SpA) was used, and a malaria peptide M5, derived from the central repeat region of the Plasmodium falciparum blood-stage antigen Pf155/RESA, served as a model immunogen in this study . Three different fusion proteins, IW-Z-M5, MI-Z-M5 and PD-Z-M5, were produced in Escherichia coli, and after affinity purification these were evaluated in iscom-incorporation experiments . Two of the fusion proteins, IW-Z-M5 and MI-Z-M5 were found in the iscom fraction following preparative ultracentrifugation, indicating iscom incorporation . This was further supported by electron microscopy analysis showing that iscoms were formed . Furthermore, these iscom preparations were demonstrated to induce efficient M5-specific antibody responses upon immunization of mice, confirming successful incorporation into iscoms . The implications of these results for the design and production of subunit vaccines are discussed.

N Engl J Med, 1999 Feb 18, 340(7), 493 - 501
Emergence of vancomycin resistance in Staphylococcus aureus . Glycopeptide-Intermediate Staphylococcus aureus Working Group; Smith TL et al.; BACKGROUND: Since the emergence of methicillin-resistant Staphylococcus aureus, the glycopeptide vancomycin has been the only uniformly effective treatment for staphylococcal infections . In 1997, two infections due to S . aureus with reduced susceptibility to vancomycin were identified in the United States . METHODS: We investigated the two patients with infections due to S . aureus with intermediate resistance to glycopeptides, as defined by a minimal inhibitory concentration of vancomycin of 8 to 16 microg per milliliter . To assess the carriage and transmission of these strains of S . aureus, we cultured samples from the patients and their contacts and evaluated the isolates . RESULTS: The first patient was a 59-year-old man in Michigan with diabetes mellitus and chronic renal failure . Peritonitis due to S . aureus with intermediate resistance to glycopeptides developed after 18 weeks of vancomycin treatment for recurrent methicillin-resistant S . aureus peritonitis associated with dialysis . The removal of the peritoneal catheter plus treatment with rifampin and trimethoprim-sulfamethoxazole eradicated the infection . The second patient was a 66-year-old man with diabetes in New Jersey . A bloodstream infection due to S . aureus with intermediate resistance to glycopeptides developed after 18 weeks of vancomycin treatment for recurrent methicillin-resistant S . aureus bacteremia . This infection was eradicated with vancomycin, gentamicin, and rifampin . Both patients died . The glycopeptide-intermediate S . aureus isolates differed by two bands on pulsed-field gel electrophoresis . On electron microscopy, the isolates from the infected patients had thicker extracellular matrixes than control methicillin-resistant S . aureus isolates . No carriage was documented among 177 contacts of the two patients . CONCLUSIONS: The emergence of S . aureus with intermediate resistance to glycopeptides emphasizes the importance of the prudent use of antibiotics, the laboratory capacity to identify resistant strains, and the use of infection-control precautions to prevent transmission.

Diagn Microbiol Infect Dis, 1999 Jan, 33(1), 43 - 6
Activity of clinafloxacin, trovafloxacin, quinupristin/dalfopristin, and other antimicrobial agents versus Staphylococcus aureus isolates with reduced susceptibility to vancomycin; Cohen MA et al.; Isolations of Staphylococcus aureus strains with reduced susceptibility to vancomycin are now being reported worldwide . In testing here by broth microdilution according to NCCLS guidelines and applying vancomycin breakpoint criteria (susceptible at 4 micrograms/mL), two of three strains were susceptible (MICs at 4 micrograms/mL) rather than intermediate (MICs at 8 micrograms/mL) as previously reported by other laboratories . Clinafloxacin was more active (MICs/MBCs at 0.5 to 2 micrograms/mL) than ciprofloxacin, grepafloxacin, levofloxacin, ofloxacin, and sparfloxacin . Trovafloxacin, trimethoprim/sulfamethoxazole, and quinupristin/dalfopristin were the next most active agents, although quinupristin/dalfopristin was bactericidal against only two of these three strains . Amikacin, imipenem, oxacillin, and rifampin were less active.

Diagn Microbiol Infect Dis, 1999 Jan, 33(1), 39 - 42
Comparison of ex-vivo serum bactericidal activity of cefepime, ceftazidime and cloxacillin against Staphylococcus aureus; Dan M et al.; Cefepime (1 g), ceftazidime (1 g), and cloxacillin (2 g) were administered intravenously to 10 volunteers each . After infusion of a single dose over 30 min, blood samples were obtained at 0.5, 1, 2, 3, 4, 5, 6, 8, 10, and 12 h (for ceftazidime at 0.5 and 4 h) after dosing . Drug levels were determined by the bioassay method . Serum bactericidal activity against five clinical isolates of cloxacillin-susceptible Staphylococcus aureus were determined by the microdilution method according to the National Committee for Clinical Laboratory Standards guidelines . The mean peak serum level was 76.88 +/- 24.71 mg/L for cefepime, 42.8 +/- 15.98 mL/L for ceftazidime, and 92.81 +/- 24.7 mg/L for cloxacillin . Concentrations of cefepime were detected during the whole testing period (mean trough level, 1.43 +/- 0.9 mg/L at 12 h), whereas concentrations of cloxacillin were measurable up to 5 h after administration (mean trough level, 0.90 +/- 0.97 mg/L) . The mean peak reciprocal bactericidal titers were 29.41 for cefepime, 5.6 for ceftazidime, and 377 for cloxacillin . Effective bactericidal titers were detected as long as 5 h for cefepime (approximately 40% of the dosing interval) and 3 h for cloxacillin (at least 50% of the dosing interval) . For ceftazidime, serum bactericidal activity was markedly lower compared with that of cefepime . Although cefepime has demonstrated an improved antistaphylococcal bactericidal activity compared with ceftazidime, it was somewhat lower than that of cloxacillin.

Br J Dermatol, 1998 Dec, 139 Suppl 53, 37 - 40
Fusidic acid in dermatology; Wilkinson JD; Fusidic acid is an antibiotic that belongs to a group of its own, the fusidanes . The molecule has a steroid-like structure but does not possess any steroid activity . The structure is thought to be responsible for the steroid-like high penetration, and for the fact that no cross-resistance or cross-allergy has been seen with other antibiotics in routine clinical use . The anti-microbial activity of fusidic acid is specifically aimed at the most common skin pathogens, including Staphylococcus aureus, towards which it is one of the most potent antibiotics . The place of fusidic acid in dermatology is in the treatment of mild to moderately severe skin and soft-tissue infections, e.g . impetigo, folicullitis, erythrasma, furunculosis, abscesses and infected traumatic wounds, whereas it is of less use in conditions such as hidradenitis suppurativa, chronic leg ulcers, burns and pressure sores . The topical combinations of fusidic acid with either betamethasone or hydrocortisone are extremely useful in the treatment of atopic dermatitis/eczema whenever staphylococcal/secondary infection is suspected, and in more persistent cases of eczema where staphylococcal superantigen may be playing an important exacerbating role.

Br J Dermatol, 1998 Dec, 139 Suppl 53, 13 - 6
Staphylococcus aureus colonization in atopic dermatitis and its therapeutic implications; Abeck D et al.; Skin colonization with Staphylococcus aureus is a characteristic feature of atopic dermatitis with more than 90% of patients being colonized . Extracellular matrix proteins are important for the adherence of S . aureus to human keratinocytes . The bacterium interferes in the inflammatory process of atopic dermatitis in various ways, among which the ability to release superantigens in a high percentage of clinical isolates is of great importance . As the colonization correlates significantly with the severity of eczema, anti-staphylococcal treatment measurements are widely used . In cases of atopic dermatitis exacerbation with wide-spread weeping lesions, a systemic antibiotic treatment is warranted, with erythromycin no longer being recommended due to an increased resistance rate . In localized superinfected lesions the topical application of an antibiotic-glucocorticoid preparation may offer advantages to the mere steroid application . Based on efficacy and resistance data, fusidic acid is the antibiotic of choice . There is evidence that phototherapy in atopic dermatitis may be even more effective when combined with anti-staphylococcal measurements . In the future new therapeutical options may be available.

Proc Natl Acad Sci U S A, 1999 Feb 16, 96(4), 1218 - 23
Structure-activity analysis of synthetic autoinducing thiolactone peptides from Staphylococcus aureus responsible for virulence; Mayville P et al.; The synthesis of virulence factors and other extracellular proteins responsible for pathogenicity in Staphylococcus aureus is under the control of the agr locus . A secreted agr-encoded peptide, AgrD, processed from the AgrD gene product, is known to be an effector of self-strain activation and cross-strain inhibition of the agr response . Biochemical analysis of AgrD peptides isolated from culture supernatants has suggested that they contain an unusual thiol ester-linked cyclic structure . In the present work, chemical synthesis is used to confirm that the mature AgrD peptides contain a thiolactone structure and that this feature is absolutely necessary for full biological activity . The AgrD synthetic thiolactone peptides exhibited biological activity in vivo in a mouse protection test . Structure-activity studies have allowed key aspects of the peptide structure involved in the differential activation and inhibition functions to be identified . Accordingly, we propose a model for activation and inhibition of the agr response in which the former, but not the latter, involves specific acylation of the agr transmembrane receptor, AgrC.

J Invest Dermatol, 1999 Feb, 112(2), 249 - 53
Evidence for superantigen involvement in skin homing of T cells in atopic dermatitis; Strickland I et al.; The environmental factors that contribute to the homing of T cells in skin disease is unknown . The skin lesions of atopic dermatitis (AD) are frequently colonized with superantigen (SAg), producing strains of Staphylococcus aureus . In vitro, these superantigens have the capacity to activate and expand T cells expressing specific T cell receptor BV gene segments, and also to increase their skin homing capacity via upregulation of the skin homing receptor, cutaneous lymphocyte-associated antigen (CLA) . These activities have been proposed to enhance the chronic cutaneous inflammation of AD, but an in vivo role for SAg has not been conclusively demonstrated . In this study, we sought direct evidence for in vivo SAg activity by comparing the SAg profiles of S . aureus cultured from the skin of AD subjects to the T cell receptor Vbeta repertoire of their skin homing (CLA+) T cells in peripheral blood . SAg secreting S . aureus strains were identified in six of 12 AD patients, and all of these subjects manifested significant SAg-appropriate Vbeta skewing within the CLA+ subsets of both their CD4+ and their CD8+ T cells . T cell receptor Vbeta skewing was not detectable among the overall CD4+ or CD8+ T cell subsets of these subjects, and was not present within the CLA+ T cell subsets of five patients with plaque psoriasis and 10 normal controls . T cell receptor BV genes from the presumptively SAg-expanded populations of skin homing T cells were cloned and sequenced from three subjects and, consistent with a SAg-driven effect, were found to be polyclonal . We conclude that SAg can contribute to AD pathogenesis by increasing the frequency of memory T cells able to migrate to and be activated within AD lesions.

Biol Pharm Bull, 1999 Jan, 22(1), 73 - 6
Biological activities of 1,1,6-trisubstituted indanes: beyond magainin 2; Numao N et al.; MSI-78 is a peptide analog of naturally occurring magainin 2 isolated from the skin of Xenopus laevis . The peptide is known to have one of the strongest antibacterial activities in magainin 2 analogs against methicillin-resistant Staphylococcus aureus (MRSA) . To find novel compounds superior to MSI-78, we have further designed, synthesizing 1,1-di(4-aminobutyl)-6-benzylindane (PM4) and 1,1-dibenzyl-6-(4-aminobutyl) indane (PM5), and tested their inhibitory ability of the growth of S . aureus . In an in vitro assay, PM4 showed the same antibacterial activity against the bacterium as MSI-78, and non-hemolytic activity against human red blood cells (RBCs) at the MIC (minimum inhibitory concentration) value, in contrast to the latter . On the other hand, PM5 showed stronger antibacterial activity than MSI-78, but being still accompanied with hemolysis at the MIC value . Otherwise, stronger decarboxylase activity for oxaloacetate was observed in PM5, rather than magainin 2 analogs or Oxaldie 1 as a control peptide, but not in PM4.

FEBS Lett, 1999 Jan 25, 443(2), 220 - 4
Programming of enzyme specificity by substrate mimetics: investigations on the Glu-specific V8 protease reveals a novel general principle of biocatalysis; Wehofsky N et al.; In this paper the universal validity of the substrate mimetic concept in enzymatic C-N ligations was expanded to anionic leaving groups based on the specificity determinants of Glu-specific endopeptidase from Staphylococcus aureus (V8 protease) . In an empirical way a specific mimetic moiety was designed from simple structure-function relationship studies . The general function of the newly developed substrate mimetics to serve as an artificial recognition site for V8 protease have been examined by hydrolysis kinetic studies . Enzymatic peptide syntheses qualify the strategy of substrate mimetics as a powerful concept for programming the enzyme specificity in the direction of a more universal application of enzymes in the general area of biocatalysis.

Microb Drug Resist, 1998 Winter, 4(4), 277 - 88
Spread of a methicillin-resistant and multiresistant epidemic clone of Staphylococcus aureus in Argentina; Corso A et al.; One hundred forty-eight recent methicillin-resistant Staphylococcus aureus (MRSA) isolates collected from 13 hospitals in Argentina were examined for antibiotic susceptibility and clonal type, using hybridization with DNA probes specific for mecA and Tn554, and pulsed-field gel electrophoresis (PFGE) of chromosomal SmaI digests . The majority of the isolates (62.2%) shared the common PFGE B pattern and carried variants of mecA and Tn554 polymorphs characteristic of an MRSA clone widely spread in Brazilian hospitals . Similarly to the Brazilian isolates, the MRSA clone recovered in the Argentinian hospitals (XI::B::B) and its close relatives (XI::B'::B, XI::AA::B, XI::M::B, XI::omega omega::B, and III::W::B) showed susceptibility to spectinomycin and resistance to numerous antibacterial agents, including beta-lactams, tetracycline, aminoglycosides, macrolides, trimethoprim/sulfamethoxazole, ciprofloxacin, and fosfomycin, and more than 60% of the isolates were also resistant to chloramphenicol and rifampin . The XI::B::B MRSA clone represented the majority of isolates recovered in most of the hospitals, nine of which were located in the city of Buenos Aires, three in the province of Buenos Aires, and one in the province of Tucuman, 1,312 km northwest of the city of Buenos Aires . The observations document further geographic expansion of this South American MRSA clone across national boundaries.

J Protein Chem, 1998 Nov, 17(8), 827 - 34
The complete amino acid sequence of a trypsin inhibitor from Bauhinia variegata var . candida seeds; Di Ciero L et al.; Trypsin inhibitors of two varieties of Bauhinia variegata seeds have been isolated and characterized . Bauhinia variegata candida trypsin inhibitor (BvcTI) and B . variegata lilac trypsin inhibitor (BvlTI) are proteins with Mr of about 20,000 without free sulfhydryl groups . Amino acid analysis shows a high content of aspartic acid, glutamic acid, serine, and glycine, and a low content of histidine, tyrosine, methionine, and lysine in both inhibitors . Isoelectric focusing for both varieties detected three isoforms (pI 4.85, 5.00, and 5.15), which were resolved by HPLC procedure . The trypsin inhibitors show Ki values of 6.9 and 1.2 nM for BvcTI and BvlTI, respectively . The N-terminal sequences of the three trypsin inhibitor isoforms from both varieties of Bauhinia variegata and the complete amino acid sequence of B . variegata var . candida L . trypsin inhibitor isoform 3 (BvcTI-3) are presented . The sequences have been determined by automated Edman degradation of the reduced and carboxymethylated proteins of the peptides resulting from Staphylococcus aureus protease and trypsin digestion . BvcTI-3 is composed of 167 residues and has a calculated molecular mass of 18,529 . Homology studies with other trypsin inhibitors show that BvcTI-3 belongs to the Kunitz family . The putative active site encompasses Arg (63)-Ile (64).

Mol Microbiol, 1998 Dec, 30(5), 991 - 1001
SarA level is a determinant of agr activation in Staphylococcus aureus; Chien Y et al.; The control of virulence determinant expression in Staphylococcus aureus is a complex process involving global regulatory loci such as sar and agr . The sar locus consists of a 372 bp sarA open reading frame (ORF) preceded by a triple promoter region interspersed with two putative smaller ORFs (ORF3 and ORF4) . The triple promoter system yields three overlapping sar transcripts (sarA, sarC and sarB of 0.56, 0.8 and 1.2 kb respectively) . We have recently shown that the SarA protein binds to the agr promoter region to stimulate the transcription of RNAII and RNAIII, two major transcripts encoded within the agr locus . To assess the role of the region upstream of sarA in agr expression, we evaluated the contribution of ORF3 and ORF4 to SarA protein expression and to agr activation by introducing nonsense mutations into the respective ORFs . Northern analysis of sar mutant clones containing these mutations carried on a shuttle plasmid revealed that all three sar-related transcripts are present . Using anti-SarA monoclonal antibodies with defined epitopes in a competitive ELISA to determine the SarA protein level, we found that the introduction of a stop codon in ORF3 on a shuttle plasmid carrying the intact sar locus in a sar mutant led to a significant decrease in SarA protein level compared with the non-mutated control . The effect of a nonsense mutation in ORF4 on SarA levels is much less . Likewise, an analogous sar mutant clone with a deletion in ORF3 also displayed a lower SarA level than its intact counterpart . The reduction in SarA expression correlated with a lower level of agr activation in the corresponding sar mutant clone . These data suggest that ORF3, and to a lesser degree ORF4, may affect agr expression by modulating SarA protein expression.

Clin Exp Obstet Gynecol, 1998, 25(4), 119 - 20
Methicillin resistant Staphylococcus aureus as a cause of chorioamnionitis; Geisler JP et al.; BACKGROUND: Chorioamnionitis is a leading cause of morbidity and mortality in preterm infants . Only rarely is Staphylococcus aureus implicated . A case of methicillin resistant Staphylococcus aureus causing chorioamnionitis and endometritis is presented . CASE REPORT: A 39-year-old gravida 2 para 1 female, who previously worked as the unit clerk in the pediatric pulmonary unit of a children's hospital, was initially admitted at 22 weeks with a shortened cervix . The patient refused emergency cerclage . She was released from the hospital and returned at 25 4/7 weeks' estimated gestational age with possible spontaneous rupture of membranes . An amniocentesis was performed and revealed a gram stain positive for many gram positive cocci as well as a glucose of < 2 mg% . The patient was started on intravenous ampicillin and gentamicin and induction of labor with oxytocin was begun . Approximately 1 day after the patient's delivery, the culture from the amniocentesis was noted to have grown methicillin resistant Staphylococcus aureus, and the patient's (as well as the neonate's) regimen was switched to vancomycin . CONCLUSION: A Medline search revealed no cases of methicillin resistant Staphylococcus aureus causing chorioamnionitis . When chorioamnionitis or refractory endometritis is encountered in a patient who works in the health care industry, methicillin resistant staphylococcus aureus must be considered.

Vaccine, 1999 Jan, 17(2), 126 - 33
Epitopic overload at the site of injection may result in suppression of the immune response to combined capsular polysaccharide conjugate vaccines; Fattom A et al.; Capsular polysaccharide (CP) conjugate vaccines targeting a variety of bacterial infections are currently under development and clinical evaluation . The inclusion of multiple CP serotypes combined in a single injection is an important maneuver being evaluated . The combination of CP conjugate vaccines into a single multivalent injection may result in competition among the different components and adversely affect the immunogenicity of any individual conjugate . We observed a reduction of 30-90% in antibody responses to several serotypes in mice when immunogenicity of a 12-valent Escherichia coli (E . coli) lipopolysaccharide (LPS) conjugate vaccine was compared to the immunogenicity of each monovalent vaccine evaluated separately . A reduction of 30% was observed in the Staphylococcus aureus (S . aureus) type 8 CP antibodies when a type 8-rEPA conjugate was combined with a type 5-rEPA conjugate . S . aureus types 5 and 8-rEPA conjugates were combined with 100 micrograms of either rEPA (homologous) or diphtheria toxoid (DT) (heterologous) carrier proteins, and evaluated in rEPA or DT primed mice . The addition of the homologous protein resulted in a 64% reduction in type 5 CP antibodies . The heterologous protein did not affect the immunogenicity of the type 5 . We postulate that the free protein competed with the conjugate and recruited most of the rEPA primed T cells . In the case of the DT conjugates, the DT targeted different populations of the T cells, thus interference was not observed . These data suggested that the epitopic load rather than the antigenic load at the site of injection caused reduced immunogenicity of the conjugates . We theorize that individual components of multivalent CP vaccines conjugated to the same carrier proteins would compete for a limited number of specific carrier protein primed T cells . This would result in one or more components being unavailable in eliciting a sufficient immune response . The use of multiple carrier proteins should be considered as an approach to reduce interference when multivalent conjugate vaccines are to be formulated into a single injection.

J Clin Microbiol, 1999 Mar, 37(3), 690 - 3
Rapid detection of epidemic strains of methicillin-resistant Staphylococcus aureus; Wichelhaus TA et al.; Fifty methicillin-resistant Staphylococcus aureus (MRSA) initial isolates obtained from patients hospitalized in the orthopedic clinic of the Frankfurt University Hospital and 150 methicillin-sensitive Staphylococcus aureus (MSSA) isolates were investigated in this study to determine whether the Slidex Staph-Kit is capable of differentiating between MRSA and MSSA owing to its unique performance characteristics . The Slidex Staph-Kit is a combined latex hemagglutination test designed to detect clumping factor, protein A, and a specific surface immunogen for S . aureus . Clumping factor-positive strains cause erythrocytes sensitized with fibrinogen to hemagglutinate, thereby resulting in visible red clumps . S . aureus strains deficient in clumping factor agglutinate latex particles sensitized with specific antibodies against surface proteins of S . aureus, thereby resulting in visible white clumps . Our results demonstrate that white clumping has a 99% specificity as well as a 98% positive predictive value for MRSA . Clumping factor-negative MRSA, which have been reported to occur in several countries, are epidemic in the Frankfurt area and account for 80% of all MRSA initial isolates in the orthopedic clinic of the Frankfurt University Hospital . Genotyping of all MRSA isolates by macrorestriction analysis of chromosomal DNA revealed that 83% of clumping factor-negative MRSA are closely related to the "southern-German" epidemic strain . This is the first study demonstrating the Slidex Staph-Kit's capability for identifying epidemic clumping factor-negative S . aureus strains as methicillin resistant even prior to antimicrobial susceptibility testing.

J Clin Microbiol, 1999 Mar, 37(3), 664 - 74
Validation of binary typing for Staphylococcus aureus strains; van Leeuwen W et al.; Most of the DNA-based methods for genetic typing of Staphylococcus aureus strains generate complex banding patterns . Therefore, we have developed a binary typing procedure involving strain-differentiating DNA probes which were generated on the basis of randomly amplified polymorphic DNA (RAPD) analysis . We present and validate the usefulness of 15 DNA probes, according to generally accepted performance criteria for molecular typing systems . RAPD analysis with multiple primers was performed on 376 S . aureus strains of which 97% were methicillin resistant (MRSA) . Among the 1,128 RAPD patterns generated, 66 were selected which identified 124 unique DNA fragments . From these amplicons, only 12% turned out to be useful for isolate-specific binary typing . The nature of the RAPD-generated DNA fragments was investigated by partial DNA sequence analysis . Several homologies with known S . aureus sequences and with genes from other species were discovered; however, 87% of the probe sequences are of previously unknown origin . The locations of most of the DNA probes on the chromosome of S . aureus NCTC 8325 were determined by hybridization . Seven fragments were randomly dispersed along the genome, five were clustered within the 2500- to 2600-kb position of the genome, and the remaining four did not recognize complementary sequences in S . aureus NCTC 8325 . A total of 103 S . aureus strains (69% MRSA) were used for the validation of the binary typing technique . The 15 DNA probes provided stable epidemiological markers, both in vitro (type consistency after serial passages on culture media) and in vivo (comparison of sequential isolates recovered from cases of persistent colonization) . The discriminatory power of binary typing (D = 0.998) exceeded that of pulsed-field gel electrophoresis (D = 0.966) and RAPD analysis (D = 0.949) . Reproducibility, measured by analyzing multiple strains belonging to a multitude of different epidemiological clusters, was comparable to that of other genotyping techniques used . Contribution of the DNA probes to the discriminatory power of the system was analyzed by comparison of dendrograms . This study demonstrates that binary typing is a robust tool for the genetic typing of S . aureus isolates.

J Clin Microbiol, 1999 Mar, 37(3), 570 - 4
Rapid identification and typing of Staphylococcus aureus by PCR-restriction fragment length polymorphism analysis of the aroA gene; Marcos JY et al.; The Staphylococcus aureus aroA gene, which encodes 5-enolpyruvylshikimate-3-phosphate synthase, was used as a target for the amplification of a 1,153-bp DNA fragment by PCR with a pair of primers of 24 and 19 nucleotides . The PCR products, which were detected by agarose gel electrophoresis, were amplified from all S . aureus strains so far analyzed (reference strains and isolates from cows and sheep with mastitis, as well as 59 isolates from humans involved in four confirmed outbreaks) . Hybridization with an internal 536-bp DNA fragment probe was positive for all PCR-positive samples . No PCR products were amplified when other Staphylococcus spp . or genera were analyzed by using the same pair of primers . The detection limit for S . aureus cells was 20 CFU when the cells were suspended in saline; however, the sensitivity of the PCR was lower (5 x 10(2) CFU) when S . aureus cells were suspended in sterilized whole milk . TaqI digestion of the PCR-generated products rendered two different restriction fragment length polymorphism patterns with the cow and sheep strains tested, and these patterns corresponded to the two different patterns obtained by antibiotic susceptibility tests . Analysis of the 59 human isolates by our easy and rapid protocol rendered results similar to those of other assays.

J Clin Microbiol, 1999 Mar, 37(3), 504 - 9
Dissemination of two methicillin-resistant Staphylococcus aureus clones exhibiting negative staphylase reactions in intensive care units; Hsueh PR et al.; From December 1997 to March 1998, 25 methicillin-resistant Staphylococcus aureus (MRSA) isolates exhibiting negative Staphylase (Oxoid Ltd., Basingstoke, England) reactions were identified from various clinical specimens from 13 patients in six intensive care units (ICUs) or in wards following a stay in an ICU at the National Taiwan University Hospital . The characteristics of these isolates have not been previously noted in other MRSA isolates from this hospital . Colonies of all these isolates were grown on Trypticase soy agar supplemented with 5% sheep blood and were nonhemolytic and unpigmented . Seven isolates, initially reported as Staphylococcus haemolyticus (5 isolates) and Staphylococcus epidermidis (2 isolates) by the routine identification scheme and with the Vitek GPI system (bioMerieux Vitek, Inc., Hazelwood, Mo.), were subsequently identified as S . aureus by positive tube coagulase tests, standard biochemical reactions, and characteristic cellular fatty acid chromatograms . The antibiotypes obtained by the E test, coagulase types, restriction fragment length polymorphism profiles of the staphylococcal coagulase gene, and random amplified polymorphic DNA patterns generated by arbitrarily primed PCR of the isolates disclosed that two major clones disseminated in the ICUs . Clone 1 (16 isolates) was resistant to clindamycin and was susceptible to trimethoprim-sulfamethoxazole (TMP-SMZ) and was coagulase type II . Clone 2 (eight isolates) was resistant to clindamycin and TMP-SMZ and was coagulase type IV . These two epidemic clones from ICUs are unique and underline the need for caution in identifying MRSA strains with colonial morphologies not of the typical type and with negative Staphylase reactions.

J Toxicol Environ Health A, 1999 Feb 12, 56(3), 165 - 82
Differential regulation of in vitro cytokine production by human blood cells in response to methylmethacrylate; Liu Y et al.; The effect of methylmethacrylate (MMA) on human whole blood cultures (WBC) obtained from healthy donors was investigated . Lymphocyte transformation and cytokine production, that is, interleukin 6 (IL-6), interferon-gamma (IFN-gamma), and tumor necrosis factor-alpha (TNF-alpha), were used to evaluate the immunological activities of MMA . Primary cytotoxicity testing of MMA in Jurkat cells showed that this compound decreased the cell proliferation to 50% at a concentration of >60 mmol/L . Similarly, MMA significantly decreased lymphocyte transformation in either phytohemagglutinin (PHA) or Staphylococcus aureus protein A (SpA) activated WBC at 100 mmol/L . In contrast to activated WBC, MMA had no observed effect on resting blood cells . Cytokine expression in WBC seemed differentially modulated by MMA . There was a tendency for IL-6 production in both resting and PHA-stimulated WBC to be upregulated, while IL-6 induced in SpA stimulated cultures was downregulated . TNF-alpha was slightly increased by MMA in resting WBC at early incubation periods, and it was slightly downregulated in response to PHA or SpA activation . Suppression of IFN-gamma secretion was observed in WBC with or without PHA or SpA stimulation . The overall results demonstrated that MMA at physiological levels could influence the cytokine production in normal human blood cells in vitro . Alterations of cytokine production patterns by MMA indicate that this compound has multiple regulatory effects on immune reactions in normal human blood.

Reg Anesth Pain Med, 1999 Jan-Feb, 24(1), 24 - 9
Effect of Staphylococcus aureus bacteria and bacterial toxins on meningeal permeability in vitro; Ummenhofer WC et al.; BACKGROUND AND OBJECTIVES: Epidural catheterization is associated with a significant bacterial colonization rate and occasionally frank infection . During epidural space infection, decreased analgesia despite increased epidural opioid doses has been described . One possible explanation for this observation is that bacterial infection decreases meningeal permeability . The purpose of the study was to determine whether Staphylococcus aureus bacteria, the most common organism causing epidural space infection, or S . aureus toxins alter meningeal permeability . METHODS: Spinal meninges of M . nemestrina monkeys were mounted in a previously established in vitro diffusion cell model and exposed to S . aureus toxins A, B, and F . Simultaneous transmeningeal fluxes of mannitol and sufentanil were measured before and after toxin exposure and compared to controls . In a second series of experiments, diffusion cells were inoculated with live S . aureus bacteria in suspension and the permeability of sufentanil was investigated . RESULTS: Staphylococcus aureus toxin-A increased the transmeningeal flux of mannitol but not sufentanil . Toxins B and F did not alter the meningeal permeability of either drug . Inoculation with live S . aureus bacteria increased the transmeningeal flux of sufentanil by 115+/-21% (P = .032) . CONCLUSIONS: These data demonstrate that S . aureus alpha-toxin and live S . aureus bacteria can increase meningeal permeability . Thus, clinical observations of decreased epidural analgesia in the face of bacterial infection cannot be explained by decreased meningeal permeability.

Minerva Anestesiol, 1998 Nov, 64(11), 529 - 34
{Therapeutic objectives and strategies in NBIA 1 (Hallovorden-Spatz syndrome)}; Bruscoli F et al.; A 10 years old male patient, DG, was admitted in the ICU because of continuous uncontrolled movements due to a neurologycal degenerative disease (Hallervorden-Spatz syndrome) able to determine reduction of spontaneous breathing efficacy . At admission he presented acute ventilatory failure, because of a Staphylococcus aureus broncopneumonia, so he had a tracheal tube and mechanical ventilation (pressure support) . During hospitalization (4 months in ICU and 2 months in Pediatric Department) DG received tracheotomy and percutaneous gastrostomy, to obtain adequate spontaneous ventilation and artificial enteral nutrition; a satisfactory pharmacological control of choreo-athetosic movements, with not great interference with original sleep-awake cycle, was obtained . Actually DG is living in his family (9 months follow-up); he has tracheotomy and percutaneous gastrostomy; he can relate with the environment; in a few months, he'll go to school again . He need 30 daily administrations of 8 different drugs; family, supported by an integrated multidisciplinary equipe, takes care of him . The role of Intensivist is essential not only in the management of acute phases in chronic diseases, but also in the longterm management of a homely care.

Vet Immunol Immunopathol, 1999 Jan 4, 67(1), 47 - 54
Pregnancy-associated glycoprotein and decreased polymorphonuclear leukocyte function in early post-partum dairy cows; Dosogne H et al.; Phagocytosis and oxidative burst activity of polymorphonuclear neutrophil leukocytes (PMN) isolated from blood and pregnancy-associated glycoprotein (bPAG) concentrations in plasma were evaluated in two longitudinal studies in dairy cows from 3 weeks before until 5 weeks after calving, carried out in the United States and in Europe . Ingestion of Staphylococcus aureus by blood PMN increased during the first week after calving and normalised 3 weeks post-partum . Phagocytosis of Escherichia coli did not change in the early post-partum period . In both studies, a significant decrease in oxidative burst activity of PMN was observed between 1 and 3 weeks after calving . In all cows, a very significant increase in plasma bPAG concentration was found between 1 week before and 2 weeks after calving . The peak of bPAG concentration in plasma immediately preceded the alterations of blood PMN functions . These results suggest that bPAG may be associated with inhibition of PMN function of dairy cows during the early post-partum period.

Invest Ophthalmol Vis Sci, 1999 Feb, 40(2), 385 - 91
Acute inflammation of the eyelid and cornea in Staphylococcus keratitis in the rabbit; Sloop GD et al.; PURPOSE: The inflammatory response during Staphylococcus keratitis was analyzed biochemically and histologically to determine the source of the neutrophils infiltrating the tear film and cornea . METHODS: Rabbit eyes were swabbed and then examined by slit-lamp microscopy at 0, 5, 10, 15, 20, and 25 hours after intracorneal inoculation with Staphylococcus aureus . Bacterial colony-forming units were quantified in the cornea, eyelid, and acute inflammatory exudate . Myeloperoxidase activity of ocular swabs of acute inflammatory exudate, corneal homogenates, and eyelid homogenates was determined . Gross and microscopic examinations of corneas and eyelids were performed . RESULTS: The colony-forming units per cornea exceeded 10(7) after 10 hours, whereas no bacteria were cultured from the eyelid until 15 hours postinfection . Slit-lamp examination revealed progressive pathology, and the myeloperoxidase activities of ocular swabs, corneas, and eyelids increased markedly by 15 hours postinfection . Corneas showed a wave of neutrophils moving from the tear film toward bacteria in the central corneal stroma and early neutrophil migration from the limbus into the stroma . In the eyelid, neutrophils migrated from the stromal vessels to the tear film . CONCLUSIONS: Staphylococcus keratitis in the rabbit causes acute inflammation in the overlying eyelid . Neutrophils of the acute inflammatory exudate interact with the infected cornea, whereas neutrophils migrating through the cornea from the limbus remained distant from the site of infection.

J Emerg Med, 1999 Jan-Feb, 17(1), 207 - 11
Staphylococcus aureus isolation from the lesions, the hands, and anterior nares of patients with atopic dermatitis; Williams JV et al.; Staphylococcus aureus colonization is common in atopic dermatitis (AD) and can exacerbate the disease . Some patients with atopic dermatitis may act as a reservoir for S . aureus transmission to others . This study compared S . aureus colonization in atopic dermatitis patients and their caregivers with control patients and their caregivers . Quantitative cultures were obtained from the lesions, clinically normal skin, hands, and anterior nares of 100 patients with atopic dermatitis, 100 controls with other cutaneous disorders, and 200 caregivers . The AD patients had significantly greater presence of S . aureus from lesional and clinically normal skin, as well as the hand . Significantly increased carriage of S . aureus was found in the anterior nares of caretakers of AD patients compared with control caretakers . Topical corticosteroid use did not affect recovery of S . aureus . There was a significant correlation between recovery of S . aureus from lesional skin and recovery from the anterior nares and hands . The nares and hands may be important reservoirs and vectors for autotransmission of S . aureus to lesional skin and for transmission to patients with AD.

J Hosp Infect, 1999 Jan, 41(1), 39 - 44
An MRSA outbreak in a urology ward and its association with Nd:YAG coagulation laser treatment of the prostate; Jones JW et al.; An outbreak of methicillin resistant Staphylococcus aureus (MRSA) involving 88 patients in a general urology ward is described . Symptomatic bacteraemia and epididymo-orchitis occurred in 10 and 8% of patients respectively . Patients had a particularly high risk of acquiring serious MRSA infection after endoscopic neodymium yttrium aluminium garnet (Nd:YAG) laser treatment of the prostate . Appreciation of the mode of transmission of MRSA, a programme of continuing education for all medical and nursing staff, simple changes in ward protocol and advances in surgical laser technique contributed to the control of the outbreak.

J Hosp Infect, 1999 Jan, 41(1), 29 - 37
Improved recognition of MRSA case clusters by the application of molecular subtyping using pulsed-field gel electrophoresis; Macfarlane L et al.; Methicillin-resistant Staphylococcus aureus (MRSA) is increasingly common in hospital and community populations, making the recognition of true nosocomial outbreaks more difficult . We have used pulsed-field gel electrophoresis (PFGE) with Sma I digestion to analyse retrospectively two perceived outbreaks of epidemic methicillin-resistant Staphylococcus aureus 15 (EMRSA 15) colonization . The first cluster of cases in patients and staff on a general ward (ward D) revealed three different antibiograms based on differences in ciprofloxacin and rifampicin sensitivities . All isolates typed using PFGE, which was more discriminatory than phage-typing . One PFGE banding profile labelled type 5 was predominant, but 12 isolates proved to be subtypes of type 5 and two were PFGE type 11 . Four staff members carried a strain not found in patients, three carried strains found in patients and transient carriage was highlighted as a problem when screening staff . PFGE enhanced the epidemiological data and proved that the cases on this ward did not comprise one large outbreak but numerous sporadic cases and smaller clusters . In contrast, isolates from a second cluster of cases which occurred on ward F were indistinguishable using antibiograms, phage-typing and PFGE, confirming this was more likely to be a true outbreak of colonization . We conclude that PFGE usefully augments epidemiological information and allows more logical infection control decisions to be made, with better utilization of scarce resources.

J Nucl Med, 1999 Jan, 40(1), 192 - 7
A novel method to label liposomes with 99mTc by the hydrazino nicotinyl derivative; Laverman P et al.; In this study a new 99mTc labeling method for polyethyleneglycol (PEG)-coated liposomes is described . The in vitro and in vivo characteristics were compared with the conventional 99mTc-HMPAO-labeled PEG-coated liposomes . METHODS: PEG-coated liposomes were labeled with 99mTc by the hydrazino nicotinyl (HYNIC) derivative of distearoylphosphatidyl-ethanolamine (DSPE) and compared with PEG-coated liposomes labeled with 99mTc-HMPAO . In vitro stability tests were performed . Biodistribution and imaging characteristics of both liposomal preparations were determined in rats with Staphylococcus aureus infection in the left calf muscle . Results: Per liposome, 230 hydrazine groups were incorporated . The labeling efficiency of the 99mTc-HYNIC liposomes was greater than 95%, so no postlabeling purification was required, in contrast to the 99mTc-HMPAO liposomes . The 99mTc-HYNIC liposomes showed greater in vitro stability than the conventional 99mTc-HMPAO liposomes . Abscess uptake of the 99mTc-HYNIC liposomes was significantly greater (1.74+/-0.38%ID/g versus 1.26+/-0.29%ID/g, 24 h postinjection, P < 0.03) . Furthermore, kidney uptake of the 99mTc-HYNIC liposomes was one third of the uptake of the 99mTc-HMPAO liposomes (0.79+/-0.07%ID/g versus 2.47+/-0.35%ID/g, 24 h postinjection, P < 0.0001) . CONCLUSION: This new 99mTc-HYNIC-based labeling method for liposomes is rapid, efficient and easy to perform . Most importantly, the 99mTc-labeled liposomes have an improved stability and in vivo characteristics . The new labeling method is a major step forward toward a radiopharmaceutical for infection imaging that can be prepared in a one-step procedure within 15 min at room temperature and thus can be applied in every routine clinical practice.

Surg Today, 1999, 29(1), 10 - 5
Tumor necrosis factor-alpha production after esophageal cancer surgery: differences in the response to lipopolysaccharide stimulation among whole blood, pleural effusion cells, and bronchoalveolar lavage fluid cells; Kimura Y et al.; The body's defense mechanism in response to stress may appear to be the sum of activation and suppression . We investigated chronological changes in tumor necrosis factor-alpha (TNF-alpha) production by local effusion cells and whole blood of esophageal cancer patients who had undergone radical resection . Whole blood, pleural effusion cells, and bronchoalveolar lavage fluid (BALF) cells were obtained from the 20 patients . Whole blood was stimulated with Escherichia coli (1 microg/ml), Staphylococcus aureus (10 microg/ml), and lipopolysaccharide (LPS) (1 microg/ml), and pleural effusion cells and BALF cells were stimulated with LPS; 24-H incubation and TNF-alpha concentration in supernate was measured by enzyme-linked immunosorbent assay (ELISA) . Within 3 h after starting the operation, TNF-alpha production in whole blood was significantly (P < 0.05) decreased compared with preoperative value by each stimulation, and this suppression persisted up to day 3 . These reductions in postoperative TNF-alpha production correlated with intraoperative hemorrhage . On the other hand, the LPS-induced release of TNF-alpha into pleural effusion cells and BALF cells were markedly increased during the study period . These results indicate that large quantities of cytokines are produced by a second attack, such as infection, in areas where immunocytes accumulate . We believe that the body reacts to surgical stress in a variety of ways . Circulating blood and immunocytes that accumulate in damaged organs are thought to react very differently to stress.

Z Naturforsch {C}, 1998 Nov-Dec, 53(11-12), 1040 - 4
Correlation between virulence of various strains of mycobacteria and their susceptibility to ethanolic extract of propolis (EEP); Scheller S et al.; Ethanol extract of propolis (EEP) has antibacterial, antiviral, antiprotozoal and antifungal properties, in addition to many biological effects . Our laboratory has demonstrated a synergistic effect of EEP and antibiotics on the growth of Staphylococcus aureus, and suggested that the bactericidal effect of EEP was expressed mainly on virulent mycobacteria rather than on non-virulent (attenuated) ones . The present study was designed to reconfirm the latter finding, by subjecting 17 different mycobacteria strains to EEP, and evaluating whether there is a correlation between the virulence of the mycobacteria strains studied and their susceptibility to EEP . Our findings demonstrate that while the four non-virulent strains studied are not susceptible to EEP, out of the 13 virulent strains studied seven are susceptible and six are resistant to it . These results suggest that while there is no full correlation between virulence of the mycobacteria tested and their susceptibility to EEP, the few strains that were resistant to EEP were non-virulent.

Clin Exp Immunol, 1999 Jan, 115(1), 95 - 102
Complement depletion aggravates Staphylococcus aureus septicaemia and septic arthritis; Sakiniene E et al.; The aim of the study was to assess the role of the complement system in Staphylococcus aureus arthritis and septicaemia . The murine model of haematogenously acquired septic arthritis was used, injecting intravenously toxic shock syndrome toxin-1 (TSST-1), producing S . aureus LS-1 . Complement was depleted using cobra venom factor (CVF) . Evaluation of arthritis was performed clinically and histopathologically . In addition, the effect of complement depletion on the phagocytic activity of leucocytes was assessed in vivo and in vitro . Six days after inoculation of S . aureus the prevalence of arthritis in decomplemented mice was three-fold higher than that in controls (91% versus 25%) . The clinical severity of arthritis at the end of the experiment, expressed as arthritic index, was 7.3 and 1.9, respectively . These findings were confirmed by histological index of synovitis as well as of cartilage and/or bone destruction being significantly higher in decomplemented mice than in controls (9.8 +/- 1.7 versus 4.9 +/- 1.2, P < 0.05; and 7.9 +/- 1.7 versus 3.0 +/- 0.9, P < 0.05, respectively) . Also, the septicaemia-induced mortality was clearly higher in decomplemented mice compared with the controls . CVF treatment significantly reduced in vivo polymorphonuclear cell-dependent inflammation induced by subcutaneous injection of olive oil and mirroring the capacity of polymorphonuclear cells (PMNC) to migrate and/or extravasate . Besides, the decomplementation procedure significantly impaired phagocytic activity of peripheral blood leucocytes in vitro, since the number of phagocytes being able to ingest bacteria decreased by 50% when the cells were maintained in decomplemented serum compared with those in intact serum . The conclusion is that complement depletion aggravates the clinical course of S . aureus arthritis and septicaemia, possibly by a combination of decreased migration/extravasation of PMNC and an impairment of phagocytosis.

Biophys J, 1999 Feb, 76(2), 837 - 45
Genetically engineered metal ion binding sites on the outside of a Channel's transmembrane beta-barrel; Kasianowicz JJ et al.; We are exploring the ability of genetically engineered versions of the Staphylococcus aureus alpha-hemolysin (alphaHL) ion channel to serve as rationally designed sensor components for analytes including divalent cations . We show here that neither the hemolytic activity nor the single channel current of wild-type alphaHL was affected by {Zn(II)} </= 1 mM . Binding sites for the divalent cations were formed by altering the number and location of coordinating side chains, e.g., histidines and aspartic acids, between positions 126 and 134, inclusive . Several mutant alphaHLs exhibited Zn(II)-induced current noise that varied with Zn(II) concentration . At a fixed divalent cation concentration, the current fluctuation kinetics depended on the analyte type, e.g., Zn(II), Cu(II), Ni(II), and Co(II) . We also show that the ability of Zn(II) to change the mutant channel current suggests that the pore's topology is beta-sheet and that position 130 is near the turn at the trans mouth . Both conclusions are consistent with the crystal structure of WT-alphaHL oligomerized in detergent . Our results, in the context of the channel's crystal structure, suggest that conductance blockades were caused by Zn(II) binding to the outside surface of the pore . Thus, analyte-induced current blockades alone might not establish whether an analyte binding site is inside a pore.

Eur J Epidemiol, 1998 Dec, 14(8), 807 - 16
Molecular characterization of methicillin-resistant Staphylococcus aureus (MRSA) in a university hospital in Italy; Villari P et al.; The molecular epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in a university hospital in Italy was studied in a five-month period in 1996, during which all S . aureus isolated were collected . All MRSA isolates (95) and a sample of methicillin-susceptible S . aureus (20) were typed with a variety of phenotypic and genotypic methods . Clonal identities were determined by pulsed-field gel electrophoresis (PFGE) of chromosomal SmaI digests and, for MRSA isolates, by probing ClaI digests with a mecA probe and a Tn554 probe . Overall, MRSA represented 32.3% of all isolates, with very high percentages from the intensive care units (adult and neonatal) . PFGE after restriction with SmaI resolved genomic DNA of 95 MRSA strains into 26 major PFGE patterns . The use of southern blot hybridization of ClaI genomic digests with mecA and Tn554 allowed us a significant increase in discrimination, differentiating at least 32 different clones . Two major clones, however, each sharing common ClaI-mecA and Tn554 type and PFGE pattern as well as a common resistance phenotype, represented more than 50% of all MRSA isolates . The recovery of these two clones in the majority of the isolates of adult and neonatal intensive care units, respectively, is indicative of typical nosocomial outbreaks and clonal spread . It is concluded that intensive care units are major areas requiring preventative interventions.

Infect Control Hosp Epidemiol, 1999 Jan, 20(1), 31 - 6
Methicillin-resistant Staphylococcus aureus and antimicrobial use in Belgian hospitals; Crowcroft NS et al.; OBJECTIVE: To investigate relationships between the incidence of methicillin-resistant Staphylococcus aureus (MRSA) and the use of different classes of antimicrobials in Belgian hospitals . DESIGN: Using Pearson correlation coefficients, the number of new nosocomial MRSA-colonized or -infected patients in the second half of 1994 and the first half of 1995 reported by the national MRSA surveillance program was compared with use of various antimicrobial classes as reported by the National Institute for Sickness and Disability Insurance . Relationships between different classes of antimicrobials were evaluated in a correlation matrix . MRSA incidence, antimicrobial use, and potential confounding factors were included in a multiple linear regression analysis . SETTING: 50 hospitals in Belgium . RESULTS: The use of a number of different classes of antimicrobials was interrelated . In the multivariate analysis, the incidence of nosocomial MRSA increased with increasing use of ceftazidime and cefsulodin (P=.0003), amoxicillin with clavulanic acid (P=.02), and quinolones (P=.005) . No association was found between MRSA incidence and total antimicrobial use . CONCLUSIONS: The relationships between antimicrobial use and MRSA are complex . Interventions aimed at promoting more rational prescribing patterns should be supported by adequate experimental and epidemiological evidence . Advice for preventing and controlling MRSA has focused mainly on hygienic measures and precautions to avoid cross-transmission; the role of relieving antimicrobial pressure needs to be clarified.

Infect Control Hosp Epidemiol, 1999 Jan, 20(1), 26 - 30
Risk factors for colonization or infection due to methicillin-resistant Staphylococcus aureus in HIV-positive patients: a retrospective case-control study; Onorato M et al.; OBJECTIVE: To determine the risk factors for colonization or infection with methicillin-resistant Staphylococcus aureus in human immunodeficiency virus (HIV)-infected patients . DESIGN: Retrospective matched-pair case-control study . SETTING: Continuity clinic and inpatient HIV service of a university medical center . POPULATION: Patients with HIV infection from the general population of eastern and coastal Texas and from the Texas Department of Criminal Justice . DATA COLLECTION: Patient charts and the AIDS Care and Clinical Research Program Database were reviewed for the following: age, race, number of admissions, total hospital days, presence of a central venous catheter, serum albumin, total white blood cell count and absolute neutrophil count, invasive or surgical procedures, any cultures positive for S . aureus, and a history of opportunistic illnesses, diabetes, or dermatologic diagnoses . Data also were collected on the administration of antibiotics, antiretroviral therapy, steroids, cancer chemotherapy, and subcutaneous medications . RESULTS: In the univariate analysis, the presence of a central venous catheter, an underlying dermatologic disease, lower serum albumin, prior steroid therapy, and prior antibiotic therapy, particularly antistaphylococcal therapy or multiple courses of antibiotics, were associated with increased risk for colonization or infection with methicillin-resistant S . aureus . Multivariate analysis yielded a model that included presence of a central venous catheter, underlying dermatologic disease, broad-spectrum antibiotic exposure, and number of hospital days as independent risk factors for colonization or infection with methicillin-resistant S . aureus . CONCLUSIONS: In our HIV-infected patient population, prior hospitalization, exposure to broad-spectrum antibiotics, presence of a central venous catheter, and dermatologic disease were risk factors for acquisition of methicillin-resistant S . aureus.

Spine, 1999 Jan 15, 24(2), 133 - 6
Epidural abscess of the cervical spine with osteomyelitis of the odontoid process; Wiedau-Pazos M et al.; STUDY DESIGN: A case report . OBJECTIVES: To document the rare condition of staphylococcal osteomyelitis of the odontoid process and to increase knowledge about the clinical characteristics and favorable outcome if patients are managed appropriately . SUMMARY OF BACKGROUND DATA: Osteomyelitis of the odontoid process caused by Staphylococcus aureus is a rare disease . A handful of cases have been reported within the last 30 years . Destructive odontoid peg involvement is most commonly associated with rheumatoid disease, which has a distinct clinical course compared with that of bacterial infection . METHODS: Two patients with bacterial osteomyelitis of the odontoid peg underwent medical and surgical treatment . They were observed for 3 years . All authors were involved in the care of these patients . RESULTS: Close monitoring of the patients' neurologic status and the use of noninvasive imaging techniques to evaluate the cervical spine led to an individualized treatment plan including antibiotic medication and transoral surgery with good outcomes in both cases . CONCLUSIONS: Awareness of the occurrence of bacterial osteomyelitis of the odontoid process, with or without neurologic symptoms, in patients with neck pain and fever may lead to earlier detection of this potentially critical condition, which has an excellent prognosis when treated early and appropriately.

Antimicrob Agents Chemother, 1999 Feb, 43(2), 421 - 3
Comparative activities of clinafloxacin, grepafloxacin, levofloxacin, moxifloxacin, ofloxacin, sparfloxacin, and trovafloxacin and nonquinolones linozelid, quinupristin-dalfopristin, gentamicin, and vancomycin against clinical isolates of ciprofloxacin-resistant and -susceptible Staphylococcus aureus strains; Jones ME et al.; The activities of eight fluoroquinolones and linezolid, quinupristin-dalfopristin (Synercid), gentamicin, and vancomycin were tested against 96 ciprofloxacin-susceptible and 205 ciprofloxacin-resistant Staphylococcus aureus strains . Overall, clinafloxacin, followed by moxifloxacin and trovafloxacin, was the most active quinolone tested . For all isolates, linezolid and quinupristin-dalfopristin showed activities that were at least comparable to vancomycin, with no cross-resistance to any other test compound.

Antimicrob Agents Chemother, 1999 Feb, 43(2), 354 - 6
Efflux pump-mediated quinolone resistance in Staphylococcus aureus strains wild type for gyrA, gyrB, grlA, and norA; Munoz-Bellido JL et al.; Fluoroquinolone efflux was studied in 47 Staphylococcus aureus clinical strains with MICs of ciprofloxacin (CFX) of < or = 2 micrograms/ml . Forty-three strains were wild type for gyrA, gyrB, and grlA quinolone resistance-determining regions and for norA and its promoter region . Forty of these strains (MICs of CFX, 0.1 to 0.2 microgram/ml) did not show efflux of fluoroquinolones . Three strains (MICs of CFX, 1 to 2 micrograms/ml) showed efflux . These results suggest that efflux can appear in S . aureus clinical strains in the absence of mutations in norA and its promoter.

Antimicrob Agents Chemother, 1999 Feb, 43(2), 335 - 40
Effects of NorA inhibitors on in vitro antibacterial activities and postantibiotic effects of levofloxacin, ciprofloxacin, and norfloxacin in genetically related strains of Staphylococcus aureus; Aeschlimann JR et al.; NorA is a membrane-associated multidrug efflux protein that can decrease susceptibility to fluoroquinolones in Staphylococcus aureus . To determine the effect of NorA inhibition on the pharmacodynamics of fluoroquinolones, we evaluated the activities of levofloxacin, ciprofloxacin, and norfloxacin with and without various NorA inhibitors against three genetically related strains of S . aureus (SA 1199, the wild-type; SA 1199B, a NorA hyperproducer with a grlA mutation; and SA 1199-3, a strain that inducibly hyperproduces NorA) using susceptibility testing, time-kill curves, and postantibiotic effect (PAE) methods . Levofloxacin had the most potent activity against all three strains and was minimally affected by addition of NorA inhibitors . In contrast, reserpine, omeprazole, and lansoprazole produced 4-fold decreases in ciprofloxacin and norfloxacin MICs and MBCs for SA 1199 and 4- to 16-fold decreases for both SA 1199B and SA 1199-3 . In time-kill experiments reserpine, omeprazole, or lansoprazole increased levofloxacin activity against SA 1199-3 alone by 2 log10 CFU/ml and increased norfloxacin and ciprofloxacin activities against all three strains by 0.5 to 4 log10 CFU/ml . Reserpine and omeprazole increased norfloxacin PAEs on SA 1199, SA 1199B, and SA 1199-3 from 0.9, 0.6, and 0.2 h to 2.5 to 4.5, 1.1 to 1.3, and 0.4 to 1.1 h, respectively; similar effects were observed with ciprofloxacin . Reserpine and omeprazole increased the levofloxacin PAE only on SA 1199B (from 1.6 to 5.0 and 3.1 h, respectively) . In conclusion, the NorA inhibitors dramatically improved the activities of the more hydrophilic fluoroquinolones (norfloxacin and ciprofloxacin) . These compounds may restore the activities of these fluoroquinolones against resistant strains of S . aureus or may potentially enhance their activities against sensitive strains.

Antimicrob Agents Chemother, 1999 Feb, 43(2), 240 - 5
glmM operon and methicillin-resistant glmM suppressor mutants in Staphylococcus aureus; Glanzmann P et al.; The Staphylococcus aureus phosphoglucosamine mutase gene glmM was shown to be the last gene of a three-cistron operon, orf1-orf2-glmM . One transcriptional start was identified upstream of orf1, and a second start producing a monocistronic transcript was identified upstream of glmM . Disruption of glmM abolished GlmM production, decreased methicillin resistance, and resulted in teicoplanin hypersusceptibility without affecting the production of the endogenous penicillin-binding proteins and PBP 2' . Complementation of the glmM mutation by the complete glmM operon restored both methicillin resistance and normal teicoplanin susceptibility . In contrast, a highly methicillin-resistant suppressor mutant obtained by selection for growth in the presence of methicillin remained GlmM deficient and teicoplanin hypersusceptible . The suppressor mutation was not linked to the glmM operon but was correlated with decreased autolysis and increased production of a 49-kDa protein, suggesting that there is an alternative pathway for glucosamine-1-phosphate synthesis in S . aureus.

FEBS Lett, 1999 Jan 8, 442(1), 34 - 8
Characterization of the bleomycin resistance determinant encoded on the transposon Tn5; Kumagai T et al.; The transposon Tn5 carries a gene, ble, which confers resistance to bleomycin (Bm) and gives a survival advantage to its host cell . We found that the ble gene product, designated BLMT, is a binding protein with a strong affinity for Bm . BLMT quenched both the antibacterial and DNA-cleaving activities of Bm, when incubated with the antibiotic . An electron spin resonance spin-trapping analysis showed that BLMT inhibits the generation of Bm-induced hydroxyl radical, by trapping Bm but not the hydroxyl radical . Western blot analysis using an anti-BLMT monoclonal antibody revealed that BLMT is immunologically distinct from Bm-binding proteins from Streptomyces verticillus, Staphylococcus aureus and Streptoalloteichus hindustanus . Escherichia coli, transformed with a mutant ble having leucine instead of proline at N-terminal amino acid position 7, lost resistance to Bm, although the cell maintained the survival benefit . This suggests that the Bm resistance mediated by ble is independent of its ability to give a survival advantage to the host bacterium.

Chirurgie, 1998 Dec, 123(6), 572 - 9
{Tricalcium phosphate, an antibiotic carrier: a study focused on experimental osteomyelitis in rabbits}; Lambotte JC et al.; PURPOSE OF THE STUDY: Macroporous beta tricalcium phosphate ceramic beads were elaborated to be a resorbable bone substitute and a drug delivery system carrying gentamicin or vancomycin . The aim of this study was to evaluate this implant into a rabbit experimental osteomyelitis . MATERIAL AND METHOD: Experimentation included 24 rabbits and was performed in three stages, according to Norden's description . Induction of osteomyelitis was obtained by injection of a sclerosing agent and of Staphylococcus aureus through the lateral side of the metaphysis of the proximal tibia . Three weeks after inoculation, animals were randomly dispatched to one of the three treatment groups . After surgical debridment (to collect cinetics data), the first group received no further treatment and was considered as a control; the second group received a ceramic implant; the third group received a gentamicin-loaded ceramic implant . Euthanasia occurred between 2 days and 21 days after the debridment . Bone samples were obtained to quantify the bacterial and gentamicin bone concentrations . Gentamicin level was also measured inside the ceramic implant . Antibiotic concentration was assessed by a immunoenzymatic method . RESULTS: Osteomyelitis was obtained in 21 of the 24 animals (87.5%) . Antibiotic release was early and complete (before the third day) but gentamicin still remained in the bone for 10 days . Bacterial concentration suggested an antimicrobial activity of the implant, but not a full sterilisation of the osteomyelitis . CONCLUSION: Norden's experimental osteomyelitis model with rabbit was proposed to assess the therapeutic activity of systemic antibiotics, but not to evaluate biomaterials . Therefore we have shifted for experimental evaluation of biomaterials to a metaphyseal osteomyelitis in the sheep, the patterns of which are close from those of the human disease.

J Am Acad Dermatol, 1999 Jan, 40(1), 77 - 84
Prophylactic antibiotics in patients undergoing laser resurfacing of the skin; Manuskiatti W et al.; BACKGROUND: Carbon dioxide (CO2) laser resurfacing produces a superficial second-degree burn that needs to be protected from bacterial and fungal infections . OBJECTIVE: We investigated the effects of various systemic and topical antimicrobial regimens . METHODS: Four different regimens using oral ciprofloxacin, topical antibiotics (intranasal mupirocin ointment and otic solution), oral ketoconazole, and oral fluconazole were tested in four time periods . The frequency and types of the infections with various regimens was compared . RESULTS: The study included 356 sequential patients who underwent facial CO2 laser resurfacing . Infections occurred in 27 patients (7.6%) . Without antibiotic prophylaxis, 8.2% of patients had bacterial infections from days 3 to 12 after the procedure (average, day 5) . With prophylactic ciprofloxacin only, 4.3% of patients had bacterial infections; these occurred almost exclusively after ciprofloxacin was discontinued . For 7 months, patients were randomly assigned to either receive or not receive mupirocin intranasally . All Staphylococcus aureus infections that occurred were seen in patients who had used intranasal mupirocin . Yeast infections were seen in 6 patients (1.7%), but mostly occurred more than 10 days after the procedure . Yeast infections were of approximately equal occurrence in the ciprofloxacin group (2.2%) and in the non-ciprofloxacin group (1.8%) . No yeast infections occurred in patients who had undergone antifungal prophylaxis . CONCLUSION: Post-CO2 resurfacing infections are not rare but can appear subtly and might only be noticeable in the second postoperative week . Prophylactic intranasal mupirocin is ineffective, but ciprofloxacin is effective in preventing infection with both gram-positive and gram-negative bacteria . Oral ketoconazole and fluconazole are effective in preventing yeast infections.

Langenbecks Arch Surg, 1998 Dec, 383(6), 460 - 5
Major injury induces increased production of interleukin-10 in human granulocyte fractions; Koller M et al.; Patients with severe trauma or polytrauma frequently acquire alterations in immune functions which are correlated to dysbalanced cytokine synthesis . In these settings the role of polymorphonuclear neutrophil granulocytes (PMN) as cytokine-producing cells is less well characterized . The immunosuppressive role of interleukin (IL)-10 is well known, and increased systemic IL-10 levels are related to the severity of injury and to posttraumatic complications . We determined concentrations of IL-10 in culture supernatants of 30 individual PMN fractions isolated from 18 severely traumatized patients (15 polytraumata, Injury Severity Score: 18-41, 3 severely burned patients) admitted to intensive care units . IL-10 was analyzed by ELISA (R&D Systems, Wiesbaden, Germany) . PMN were isolated from EDTA-anticoagulated peripheral blood employing a one-step procedure based on a discontinuous double Ficoll gradient . The cells {1 x 10(6)/ml RPMI 1640 supplemented with 10% fetal calf serum and 25 mM N-(2-hydroxyethyl)-piperazine-N'-(2-ethanesulfonic acid} were stimulated with 0.05% heat-killed Staphylococcus aureus (Pansorbin, Calbiochem-Novabiochem, Bad Soden, Germany) for 24 h using cell culture conditions . Our results show that PMN fractions of traumatized patients produce significantly (P<0.008) higher amounts of IL-10 (354+/-95 pg/ml, n = 30) than normal healthy donor cells (125+/-95 pg/ml, n = 7) . IL-10 release from PMN fractions exceeded the release from isolated patients' peripheral blood mononuclear cells induced by similar stimulation or by stimulation with toxic shock syndrome toxin-1 (10 ng) and concanavalin A (2 microg) . Our results provide evidence that PMN fractions play an active role in the development of posttraumatic immunosuppression by autocrine or paracrine mechanisms, for example, by suppressing one's own antimicrobial activities or determining the development of T-cell responses via their ability to release IL-10.

J Biol Chem, 1999 Feb 5, 274(6), 3541 - 8
Bioenergetics of the staphylococcal multidrug export protein QacA . Identification of distinct binding sites for monovalent and divalent cations; Mitchell BA et al.; The multidrug efflux pump QacA from Staphylococcus aureus confers resistance to an extensive range of structurally dissimilar compounds . Fluorimetric analyses demonstrated that QacA confers resistance to the divalent cation 4',6-diamidino-2-phenylindole, utilizing a proton motive force-dependent efflux mechanism previously demonstrated for QacA-mediated resistance to the monovalent cation ethidium . Both the ionophores nigericin and valinomycin inhibited QacA-mediated export of ethidium, indicating an electrogenic drug/nH+ (n >/= 2) antiport mechanism . The kinetic parameters, Km and Vmax, were determined for QacA-mediated export of four fluorescent substrates, 4',6-diamidino-2-phenylindole, 3', 3'-dipropyloxacarbocyanine, ethidium, and pyronin Y . Competition studies showed that QacA-mediated ethidium export is competitively inhibited by monovalent cations, e.g . benzalkonium, and non-competitively inhibited by divalent cations, e.g . propamidine, which suggests that monovalent and divalent cations bind at distinct sites on the QacA protein . The quaternary ammonium salt, 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene, was used as a membrane-specific fluorescence probe and demonstrated that the amount of substrate entering the inner leaflet was significantly reduced in QacA-containing strains, supporting the notion that the substrate is extruded directly from the membrane.

J Med Microbiol, 1999 Jan, 48(1), 17 - 23
DNA typing of methicillin-resistant Staphylococcus aureus: isolates and factors associated with nosocomial acquisition in two Brazilian university hospitals; Santos KR et al.; Control and prevention of methicillin-resistant Staphylococcus aureus (MRSA) infections should include early identification of patients at higher risk of MRSA acquisition and analysis of isolates by discriminatory bacterial DNA typing methods . One hundred and three MRSA isolates cultured between Sept . 1994 and Sept . 1995 from 62 patients in two teaching hospitals (hospital 1, in Rio de Janeiro; hospital 2, in Minas Gerais) were tested for antimicrobial resistance and genomic DNA was analysed by pulsed-field gel electrophoresis (PFGE) . Ten profiles were identified: A, B, C, I and J in hospital 1 and A, B, D, E, F, G and H in hospital 2 . PFGE patterns A and B were isolated at both hospitals . The majority (80%) of isolates had similar PFGE patterns (type A) . Subtype A1 was isolated at both hospitals, but was more frequent in hospital 2 (54%), while subtype A2 predominated in hospital 1 (63%) . MRSA isolates were resistant to the majority of antimicrobial agents tested . However, susceptibility to vancomycin alone was found in 32% of the isolates at hospital 1, whereas 48% of isolates from hospital 2 were susceptible to both vancomycin and mupirocin, and 34% demonstrated susceptibility to vancomycin, mupirocin and chloramphenicol . Thirty-nine percent of all isolates were mupirocin-resistant, with 90% of these belonging to PFGE pattern A . Four main risk factors were associated with MRSA infection or colonisation which may be useful in the early identification of patients at risk: >7 days hospitalisation (95%), very dependent patients (84%), invasive procedures (79%) and recent antimicrobial therapy (79%) . The data demonstrate that PFGE pattern A is disseminated in both hospitals . However, at both hospitals subtypes of pattern A and the other PFGE types were associated with different antibiotic resistance patterns.

Neurol Med Chir (Tokyo), 1998 Nov, 38(11), 743 - 5
Subdural empyema caused by hematogenous dissemination from an abscess in thigh to a preexisting chronic subdural hematoma--case report; Kawamoto S et al.; A 63-year-old male with a preexisting chronic subdural hematoma presented with progressive confusion and left hemiparesis as well as high fever . Subdural empyema was strongly suspected . At surgery, the empyema was encapsulated by definite inner and outer membranes . Cultures isolated from the subdural fluid and from an abscess of his left thigh yielded methicillin-resistant Staphylococcus aureus . A pulsed-field gel electrophoresis showed these two strains were genetically identical . Hematogenous infection of a preexisting subdural hematoma is an extremely rare cause of subdural empyema.

FEMS Microbiol Lett, 1999 Jan 1, 170(1), 97 - 103
Genetic analysis of the cap5 locus of Staphylococcus aureus; Wann ER et al.; Staphylococcus aureus expresses at least eight distinct serotypes of capsular polysaccharide (CP) . Gene clusters involved in the expression of serotypes 1, 5 and 8 have been cloned and sequenced . In this report we describe the isolation and analysis of serotype 5 capsular polysaccharide-defective mutants . A naturally occurring cap mutation in the laboratory strains 8325-4 and RN4220 was mapped to the cap5E gene by genetic complementation . The cap5H-K genes were shown to be responsible for CP5 serotype specificity by transduction and complementation.

Anal Biochem, 1999 Feb 1, 267(1), 57 - 64
Carbamylation of cysteine: a potential artifact in peptide mapping of hemoglobins in the presence of urea; Lippincott J et al.; Peptide mapping is a useful technique for identifying posttranslational modifications . However, sometimes artifacts can be introduced during the mapping procedure which can be misleading in identifying the origin and nature of the modifications . During peptide mapping of unalkylated hemoglobins with Staphylococcus aureus V8 proteinase, we found a significant level of carbamylated cysteines . Carbamylation was not detected if recombinant human hemoglobin (rHb1.1) was alkylated prior to digestion . Our experiments indicated that this modification was an artifact of the digestion procedure in which the slightly acidic conditions promoted the reaction of cysteine sulfhydryls with residual cyanate derived from urea . Carbamylmercaptans were found to be stable under acidic conditions but were unstable in base . The extent of cysteine carbamylation can be moderated by the use of scavengers .

Ophthalmology, 1999 Jan, 106(1), 142 - 7
Methicillin-resistant Staphylococcus aureus infections after scleral buckling procedures for retinal detachments associated with atopic dermatitis; Oshima Y et al.; OBJECTIVE: To determine the incidence and the clinical course of methicillin-resistant Staphylococcus aureus as a cause of acute-onset infections in patients with atopic dermatitis after a scleral buckling procedures . DESIGN: A retrospective chart review . PARTICIPANTS: Two hundred eighty-seven patients (293 eyes) who underwent scleral buckling procedures to treat rhegmatogenous retinal detachments at either Osaka Rosai Hospital or Osaka University Medical School between July 1, 1995, and June 30, 1997, participated . Of these, 32 eyes (10.9%) were associated with atopic dermatitis . INTERVENTION: Demographic and clinical data were abstracted from patients' medical records . MAIN OUTCOME MEASURES: The incidence, clinical features, and management of postoperative infections associated with methicillin-resistant S . aureus were studied . RESULTS: Methicillin-resistant S . aureus infection after scleral buckling procedures was identified in 6 (18.8%) of 32 eyes of patients with atopic dermatitis but in only 1 (0.4%) of the other 261 cases without atopic dermatitis (P < 0.001) . The average interval from the scleral buckling procedures to the initial onset of infection was 8.3 +/- 9.1 days (range, 2-28 days) . Bacterial infection and inflammation were controlled in four eyes by prompt removal of the infected buckle in combination with vancomycin administration . In the other three eyes, however, repeat intravitreous injections of vancomycin or emergent vitrectomies were required because of the development of endophthalmitis . CONCLUSIONS: Methicillin-resistant S . aureus is an important causative pathogen of scleral buckling infections, particularly in patients with retinal detachment associated with atopic dermatitis . Preoperative evaluation and intraoperative attention to contamination are recommended to prevent methicillin-resistant S . aureus infections in these patients.

Clin Orthop, 1998 Oct, (355), 290 - 9
Osteoclasts and effects of interleukin 4 in development of chronic osteomyelitis; Pesanti EL et al.; The cellular response to trauma and infection was studied in a murine model of posttraumatic osteomyelitis . Osteoclast response differed markedly depending on whether infection with Staphylococcus aureus accompanied the bone trauma . In animals recovering from sterile trauma, osteoclastic activity that was limited to the damaged or dead bone fragments caused rapid elimination of all recognizable dead bone within 1 week . New bone was laid down in an orderly fashion . Animals with superimposed infection had an intense polymorphonuclear leukocyte response develop . Additionally, osteoclasts behaved as acute inflammatory responders with substantial activity at the margins of the infected site and at previously uninjured tibial cortex adjacent to the infection . Despite the exuberant osteoclast response, bony fragments were not resorbed (for at least 4 weeks after the trauma), that is, sequestra developed, and new bone was laid down over morphologically dead bone and on the cortex (involucrum) . When the inhibitory cytokine, interleukin 4 was given in a single dose with the bacterial inoculum, the osteoclast response was moderated with almost complete elimination of osteoclast activity at normal tibial cortex adjacent to the infected site . The limitation of osteoclastic activity did not impair the host's containment of bacterial growth.

J Mol Biol, 1999 Jan 29, 285(4), 1339 - 46
Cross-linking localization of a HIV-1 reverse transcriptase peptide involved in the binding of primer tRNALys3; Dufour E et al.; Human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) initiates the synthesis of DNA from the 3' end of its specific primer, tRNALys3 . The regions of tRNALys3 in close contact with RT are well known, while a precise knowledge of the RT regions interacting with tRNALys3 is not yet available . To address this question we cross-linked the heterodimeric p66/p51 RT to tRNALys3 using cis-aquahydroxydiammino-platinum . Ribonucleoprotein complexes of molecular masses higher than the p66 subunit were obtained . After RNase A digestion of the RT-tRNA complex, a labeled oligoribonucleotide (ORN) was mainly found associated to the p66 subunit . This labeled p66-ORN complex was then proteolyzed with Staphylococcus aureus V8 protease . A highly purified radioactive peptide was obtained after two chromatographic purification steps . Its N-terminal sequence corresponded with amino acid residues 241VQPI244 . Using the crystallographic structure of HIV-1 RT, this peptide was localized at the beta14-sheet end, near to the hairpin formed by beta12 and beta13-sheets ("primer grip") and the alphaH-helix . The so called "VQPI peptide" is in the border of the thumb and the palm subdomains of the p66 subunit . This study palliates the absence of a three- dimensional structure of the RT-tRNA complex and led to a peptide in interaction with tRNALys3 present in all HIV-1 RT isolates .

J Antibiot (Tokyo), 1998 Oct, 51(10), 929 - 35
A new anti-MRSA antibiotic complex, WAP-8294A . I . Taxonomy, isolation and biological activities; Kato A et al.; WAP-8294A, produced by Lysobacter sp., is a complex consisting of water soluble depsipeptide antibiotics . It was further purified by column chromatographies and HPLC, and 19 components were obtained . WAP-8294A2, a major component, and minor components A1, A4, Ax8, Ax9 and Ax13 were active against gram-positive bacteria, in particular, methicillin-resistant Staphylococcus aureus (MRSA) in vitro . WAP-8294A2 was highly active in vivo in mice against the systemic infection of MRSA.

Int J Antimicrob Agents, 1998 Nov, 10(4), 309 - 12
Typing of consecutive methicillin-resistant Staphylococcus aureus isolates from intensive care unit patients and staff with pulsed-field gel electrophoresis; Mueller-Premru M et al.; Six consecutive methicillin-resistant Staphylococcus aureus (MRSA) isolates obtained in a 2-month period from tracheal aspirates of six intensive care unit (ICU) patients with nosocomial pneumonia and two MRSA isolates from nasal carriers among staff were typed to determine whether one or more strains were involved and whether nasal carriage was the source of the outbreak . Pulsed-field gel electrophoresis (PFGE) of chromosomal DNA was used to type MRSA isolates . The typing showed that the outbreak was caused by a single epidemic MRSA clone . The MRSA strain isolated from the staff was unrelated to the outbreak strain and was therefore not the source of the outbreak in this study . The source was apparently the index patient followed by transfer of MRSA to other patients on medical equipment or on the hands of staff who did not adhere strictly to infection control measures.

J Immunol, 1999 Jan 15, 162(2), 939 - 47
Regulation and functional involvement of macrophage scavenger receptor MARCO in clearance of bacteria in vivo; van der Laan LJ et al.; The scavenger receptors expressed by macrophages are thought to play an important role in the immune response against bacteria by mediating binding and phagocytosis . A novel member of the class A scavenger receptor family, macrophage receptor with collagenous structure (MARCO), has recently been identified . In this study we have generated a panel of mAbs with specificities for different domains of this receptor . Two of those reacting with the C-terminal cysteine-rich domain block ligand binding of MARCO . The in vivo expression of this murine receptor is normally restricted to distinct populations of macrophages in the spleen and lymph nodes . During bacillus Calmette-Guerin (BCG) infection, during bacterial sepsis, or after the injection of purified LPS, however, the expression of MARCO is rapidly induced on macrophages in other tissues, including Kupffer cells in the liver . Using the mouse macrophage cell line J774.2, it was shown that LPS stimulation up-regulates surface expression of MARCO in a dose- and time-dependent fashion . The proinflammatory cytokines IL-1, IL-6, TNF-alpha, and IFN-gamma had little or no effect . Using inhibitory mAbs, the relevance of MARCO for the clearance of circulating bacteria in vivo was determined . Although the overall elimination of live Escherichia coli and Staphylococcus aureus from the blood did not appear to be affected by treatment with these Abs, the capturing of heat-killed bacteria by macrophages in the marginal zone areas of the spleen was clearly inhibited . This study suggests a role for MARCO in the host antibacterial defense.

Kansenshogaku Zasshi, 1998 Dec, 72(12), 1269 - 74
{Immunoglobulin production by human peripheral B cells against Staphylococcus aureus}; Miyashita T et al.; Immunoglobulin (Ig) production by human B cells in thymus-independent (TI) and -dependent (TD) immune response against Staphylococcus aureus was investigated in vitro . Highly purified human peripheral B cells were cultured either in the presence of formalinized Cowan I strain Staphylococcus aureus (SAC) or with anti-CD3 stimulated T cells, and Ig content in supernatants was analyzed after 10 days of culture by specific sandwich ELISA . When activated with SAC in the absence of T cells, B cells produced minimal amounts of Ig . In the presence of interleukin-2 (IL-2) or supplemental recombinant CD40 ligand plus IL-2, Ig production by SAC-induced B cells was dramatically enhanced . When cultured with T cells stimulated with low concentrations of anti-CD3 or when cultured with smaller numbers of T cells, B cells produced large amounts of Ig, whereas T cells stimulated with higher concentrations of anti-CD3 or large numbers of T cells failed to induce effective Ig secretion by B cells . These findings suggest that TI immune response against Staphylococcus aureus is strongly enhanced in the presence of activated T cells in an antigen non-specific manner, indicating its critical role in the local humoral immune defense . Moreover, it is indicated that the secretion of Ig induced by TD antigens participates in the immune defense against Staphyloccocus aureus dependent on activated T cell/B cell ratio or an impact of CD3 stimulation on T cells.

Kansenshogaku Zasshi, 1998 Dec, 72(12), 1253 - 60
{Nosocomial pneumonia experienced in a community hospital}; Kobashi Y et al.; To clarify the characteristic features of nosocomial pneumonia in a community hospital, we performed a clinical analysis of 147 patients (155 episodes) with nosocomial pneumonia . The following results were obtained . 1, Regarding the risk factors for nosocomial pneumonia, factors such as the patient whose age was over 65 years, a duration of admission of over one month, performance status 4 and underlying respiratory diseases associated with the appearance of nosocomial pneumonia . 2, The causative microorganism isolated from the sputum of the patient with nosocomial pneumonia was frequently a multi-drug resistant microorganism such as Methicillin-resistant Staphylococcus aureus (MRSA) . 3, regarding treatment, although several antibiotics were administered for a long time, mechanical ventilation was used on 31% of the patients, and steroid pulse therapy was carried out on 24% . The clinical efficacy was poor with a 50% mortality rate . The reason why treatment of nosocomial pneumonia was difficult is thought to be been related to the general condition of these inpatients and to the appearance of a multi-drug resistant, polymicrobial microorganisms.

Zentralbl Hyg Umweltmed, 1998 Dec, 201(4-5), 311 - 23
Model tests for the efficacy of disinfectants on surfaces . IV . Communication: dependence of test results on the amount of contamination and the kind of active substance; Peters J et al.; In the assessment of efficacy of surface disinfectants, many influencing factors have to be taken into account . One essential item is whether the surface to be disinfected is clean or soiled . Among the feasible soilings, the blood is of particular consequences because it ads impediments to many disinfecting agents . This paper shows to what extent the impairment of the efficacy of typical active agents depends on the blood burden of the surfaces . Therefore, test surfaces (varnished plywood) were contaminated with 0.01 to 0.08 ml of coagulating blood per test area (3 cm2) . The blood contained cells of Staphylococcus aureus as test germs . The disinfection was effected by immersing the test objects in the disinfecting solution for 5 seconds and mingling the adhering disinfecting solution (about 0.02 ml) with the coagulated blood on the test surface with a glass spatula for about 20 seconds . Subsequently, the test objects remained in a horizontal position at room conditions for 4 hours and then the numbers of surviving test germs were determined . The graphical representation of the results shows that the efficacy curves of formaldehyde and phenol lie very closely together, i.e . their effect is hardly impaired by the different blood burdens of the test areas . The efficacy curves of glutaraldehyde, peracetic acid, chloramine T, and quaternary ammonium compounds lie very far apart from each other . To achieve the same microbicidal effect (log N/N0 = -5) when the contaminating amount is raised from 10 microliters/3 cm2 to 80 microliters/3 cm2, the concentration of chloramine T has to be raised by a factor of 5.4, peracetic acid by a factor of 9, glutaraldehyde by a factor of 24, quaternary ammonium compound even by a factor of 67 . Ethanol and sodium hypochlorite showed a divergent behaviour . For ethanol, the efficacy diminution produced by increasing the contamination amount by a factor of 4 can be compensated by raising the concentration from 50% to about 70% . But again and again, there were test objects on which the number of germs able to reproduce had only been lowered by a factor of about 10(-3) . At the highest contamination of 80 microliters/3 cm2, even 95% ethanol proved to be completely insufficient . With sodium hypochlorite even at the lowest contamination of 10 microliters/3 cm2, a microbicidal effect of only about 10(-5) was obtained . With increasing contamination, the highest achievable microbicidal effect clearly decreased . It is remarkable that the microbicidal effect of this active agent decreased with increasing concentrations . The results show how important it is in testing the efficacy of disinfecting agents to exactly lay down the amount of contaminating substances . To find out how safely an agent works under harder circumstances, the dependence of the microbicidal effect from the amount of contaminating substances per test area has to be determined.

Infect Immun, 1999 Feb, 67(2), 740 - 4
Impact of the high-affinity proline permease gene (putP) on the virulence of Staphylococcus aureus in experimental endocarditis; Bayer AS et al.; Staphylococcus aureus causes a wide variety of invasive human infections . However, delineation of the genes which are essential for the in vivo survival of this pathogen has not been accomplished to date . Using signature tag mutagenesis techniques and large mutant pool screens, previous investigators identified several major gene classes as candidate essential gene loci for in vivo survival; these include genes for amino acid transporters, oligopeptide transporters, and lantibiotic synthesis (W . R . Schwan, S . N . Coulter, E . Y . W . Ng, M . H . Langhorne, H . D . Ritchie, L . L . Brody, S . Westbrock-Wadman, A . S . Bayer, K . R . Folger, and C . K . Stover, Infect . Immun . 66:567-572, 1998) . In this study, we directly compared the virulence of four such isogenic signature tag mutants with that of the parental strain (RN6390) by using a prototypical model of invasive S . aureus infection, experimental endocarditis (IE) . The oligonucleotide signature tag (OST) mutant with insertional inactivation of the gene (putP) which encodes the high-affinity transporter for proline uptake exhibited significantly reduced virulence in the IE model across three challenge inocula (10(4) to 10(6) CFU) in terms of achievable intravegetation densities (P, <0.05) . The negative impact of putP inactivation on in vivo survival in the IE model was confirmed by simultaneous challenge with the original putP mutant and the parental strain as well as by challenge with a putP mutant in which this genetic inactivation was transduced into a distinct parental strain (S6C) . In contrast, inactivation of loci encoding an oligopeptide transporter, a purine repressor, and lantibiotic biosynthesis had no substantial impact on the capacity of OST mutants to survive within IE vegetations . Thus, genes encoding the uptake of essential amino acids may well represent novel targets for new drug development . These data also confirm the utility of the OST technique as an important screening methodology for identifying candidate genes as requisite loci for the in vivo survival of S . aureus.

Infect Immun, 1999 Feb, 67(2), 589 - 94
Inhibition of Staphylococcus aureus adherence to collagen under dynamic conditions; Mohamed N et al.; Staphylococcus aureus is the most common etiological agent of bacterial arthritis and acute osteomyelitis and has been shown to bind to type II collagen under static and dynamic conditions . We have previously reported the effect of shear on the adhesion of S . aureus Phillips to collagen and found that this process is shear dependent (Z . Li, M . Hook, J . M . Patti, and J . M . Ross, Ann . Biomed . Eng . 24{Suppl . 1}:S-55) . In this study, we used recombinant collagen adhesin fragments as well as polyclonal antibodies generated against adhesin fragments in attempts to inhibit bacterial adhesion . A parallel-plate flow chamber was used in a dynamic adhesion assay, and quantification of adhesion was accomplished by phase contrast video microscopy coupled with digital image processing . We report that both recombinant fragments studied, M19 and M55, and both polyclonal antibodies studied, alpha-M17 and alpha-M55, inhibit adhesion to varying degrees and that these processes are shear dependent . The M55 peptide and alpha-M55 cause much higher levels of inhibition than M19 and alpha-M17, respectively, at all wall shear rates studied . Our results demonstrate the importance of using a dynamic system in the assessment of inhibitory strategies and suggest the possible use of M55 and alpha-M55 in clinical applications to prevent infections caused by S . aureus adhesion to collagen.

J Biol Chem, 1999 Jan 29, 274(5), 2845 - 50
Characterization of the elastin binding domain in the cell-surface 25-kDa elastin-binding protein of staphylococcus aureus (EbpS); Park PW et al.; Our previous studies have established that a cell-surface 25-kDa elastin-binding protein of Staphylococcus aureus (EbpS) mediates binding of this pathogen to the extracellular matrix protein elastin . Results from binding assays examining the activity of various EbpS fragments suggested that the elastin recognition domain is contained within the first 59 amino acids . In this report, we have used functional analyses with synthetic peptides and recombinant truncated forms of EbpS to localize the elastin binding domain to a 21-amino acid region contained within residues 14-34 of EbpS . Further evidence for the importance of this domain was obtained by demonstrating that the inhibitory activity of anti-EbpS antibodies on staphylococcal elastin binding was neutralized when these antibodies were pre-absorbed with a truncated recombinant EbpS construct containing residues 1-34 . Overlapping synthetic peptides corresponding to EbpS residues 14-36 were then generated and tested for elastin binding activity to define further the elastin binding domain, and results from these studies showed that sequences spanning amino acids Gln14-Asp23, Asp17-Asp23, and Thr18-Glu34 inhibit binding of Staphylococcus aureus to elastin . Our analyses indicate that the hexameric sequence Thr18-Asn-Ser-His-Gln-Asp23 is the minimal sequence common to all active synthetic peptides, proteolytic fragments, and recombinant constructs of EbpS . Furthermore, substitution of Asp23 with Asn abrogated the blocking activity of the synthetic peptides, demonstrating the requirement for a charged amino acid at this location . The composite data indicate that staphylococcal elastin binding is mediated by a discrete domain defined by short peptide sequences in the amino-terminal extracellular region of EbpS.

Tohoku J Exp Med, 1998 Sep, 186(1), 67 - 70
Specificity of 4'''-acetylation by an aminoglycoside-modifying enzyme in arbekacin-resistant strains of methicillin-resistant Staphylococcus aureus; Fujimura S et al.; Four arbekacin (ABK)-resistant clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) were studied regarding their mechanism of aminoglycoside-resistance . Metabolites of amikacin (AMK) and gentamicin(GM) were obtained by reaction with excess amounts of crude enzyme preparation extracted from the ABK-resistant MRSA strains . Then the metabolites were then isolated and analyzed by means of 1H, 13C-nuclear magnetic resonance . The AMK-modification was 4'''-N-acetylation . However, the site of GM-acetylation may be 6'-N-position by these strains.

Tohoku J Exp Med, 1998 Sep, 186(1), 61 - 6
Efficacy of long-term sulfamethoxazole-trimethoprim therapy in a boy with hyperimmunoglobulin E syndrome; Tanaka H et al.; A boy with hyperimmunoglobulin E syndrome (HIE syndrome), who was successfully treated with long-term sulfamethoxazole-trimethoprim (SMX-TMP) is reported . He had been suffering from recurrent pruritic dermatitis soon after birth and had a significant high level of serum immunoglobulin E . Although an initiation of SMX-TMP therapy resulted in resolution of his clinical manifestations, cessation of the treatment exacerbated the symptoms . Chemoprophylaxis of other oral antibiotics, which were suitable for Staphylococcus aureus isolated from lesions of the patient were unsuccessful . Another trial of low-dose SMX-TMP therapy resulted in gradual subsidence of the clinical manifestations . From these observations, efficacy of SMX-TMP therapy to prevent bacterial infection in the patient is clinically apparent . Although precise mechanism of the therapy remains speculative, long-term SMX-TMP therapy might be of benefit and low clinical toxicity in HIE syndrome.

Hautarzt, 1998 Dec, 49(12), 902 - 6
{Cutaneous Staphylococcus aureus colonisation of atopic eczema . Mechanisms, pathophysiological importance and therapeutic consequences}; Abeck D et al.; Mechanisms for the increased Staphylococcus aureus colonization in atopic eczema are only partially known . From the aspect of the bacterium, the presence of various extracellular matrix components seems important . In the host epidermal lipid deficencies disturbing barrier dysfunction are important . Staphylococcus aureus' immunological and inflammatory effects include the release of superantigens, additional exotoxins and exoenzymes and perhaps bacterial DNA-triggered mechanisms . Therapeutic possibilities include the use of systemic antibiotics in cases of generalized superinfected atopic eczema, the use of corticosteroids and specific antibiotic-antiseptic combinations in cases of localised superinfected atopic eczema and the wide-spread use of topical antiseptics in cases of microbial-laden atopic eczema.

ORL J Otorhinolaryngol Relat Spec, 1999 Jan-Feb, 61(1), 45 - 7
Methicillin-resistant Staphylococcus aureus neck infections resulting in a delayed abscess and a tracheo-oesophageal fistula; Ahmad I et al.; We describe 2 cases of methicillin-resistant Staphylococcus aureus neck infections resulting in a deep neck abscess in one and formation of a tracheo-oesophageal fistula in the other . Predisposing factors, preventive measures and the principles of management are discussed . The role of carrier detection and rational use of antibiotics are highlighted.

J Allergy Clin Immunol, 1999 Jan, 103(1 Pt 1), 119 - 24
Prevalence and role of serum IgE antibodies to the Staphylococcus aureus-derived superantigens SEA and SEB in children with atopic dermatitis; Bunikowski R et al.; BACKGROUND: The skin of patients with atopic dermatitis exhibits a striking susceptibility to colonization and infection with Staphylococcus aureus . In this context it has been previously shown that S aureus-derived superantigens could function as classic allergens, inducing production of functionally relevant specific IgE antibodies . OBJECTIVE: The aim of this study was to determine the prevalence and the role of circulating staphylococcal enterotoxin A (SEA)- and staphylococcal enterotoxin B (SEB)-specific IgE antibodies in children with atopic dermatitis . METHODS: In a cross-sectional study of 58 children with atopic dermatitis, the presence of IgE antibodies to SEA and SEB was correlated with the severity of the disease and the total and other unrelated allergen-specific IgE titers and density of colonization with S aureus strains on atopic skin and episodes of superficial S aureus skin infections . RESULTS: Twenty of 58 children (34%) were sensitized to superantigens (45% to SEB, 10% to SEA, 45% to SEA and SEB) . In this group, severity of atopic dermatitis and levels of specific IgE to food and air allergens were significantly higher . The degree of disease severity correlated to a higher extent with the presence of SEA/SEB-specific antibodies than with total serum IgE levels . Density of colonization with superantigen-secreting S aureus strains was higher in the superantigen IgE-positive group . Sixty-three percent of these children experienced repeated episodes of superficialS aureus skin infections . CONCLUSIONS: Sensitization to S aureus-derived superantigens may be involved in disease exacerbation . The presence of SEA/SEB-specific antibodies had additional explanatory value for disease severity and therefore may be helpful in the characterization of children with severe atopic dermatitis.

J Infect, 1998 Nov, 37(3), 274 - 81
Molecular epidemiology as an effective tool in the surveillance of infections in the neonatal intensive care unit; Villari P et al.; OBJECTIVES: nosocomial infections result in considerable morbidity and mortality in Neonatal Intensive Care Units (NICUs) . The aim of this study was to investigate the usefulness of the molecular epidemiology approach in the surveillance and control of infections in the NICU . METHODS: a 1-year prospective surveillance of nosocomial infections in a NICU was performed using traditional epidemiological methods as well as molecular typing of micro-organisms . RESULTS: the nosocomial infection rate among the 343 newborns was 24.8% . The risk of infection was associated with low birth weight, prolonged length of stay, empiric antibiotic treatment and nasopharyngeal colonization . Four pathogens (Klebsiella pneumoniae, methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant Staphylococcus epidermidis (MRSE) and methicillin-sensitive Staphylococcus aureus (MSSA) were responsible for more than 80% of the infections . Extended-spectrum beta-lactamase-producing (ESBL) K . pneumoniae and MRSA infections constituted outbreaks caused by a single clone, whereas MRSE and MSSA infections did not represent outbreaks but rather a series of sporadic infections caused by different strains . CONCLUSIONS: molecular epidemiology techniques are powerful tools that can elucidate modes of spread and reservoirs of infection in the NICU and identify effective measures to control epidemic or endemic situations.

J Dermatol Sci, 1999 Jan, 19(1), 31 - 6
Suppressive effect of ultraviolet (UVB and PUVA) radiation on superantigen production by Staphylococcus aureus; Yoshimura-Mishima M et al.; It is well known that Staphylococcus aureus (S . aureus) proliferates on the moist skin lesion of atopic dermatitis . Reduction of bacteria colonization from skin lesions by antibiotics has been reported to be effective for the treatment of atopic dermatitis . S . aureus produces superantigens which can activate T cells and possibly enhance the inflammatory reaction . Photo(chemo)therapy has been successfully used for the treatment of severe cases of atopic dermatitis . We have previously reported that photo(chemo)therapy had bacteriostatic effect on S . aureus . Now we examined the effect of UVB and psoralen plus UVA (PUVA) on superantigen production from S . aureus . We isolated S . aureus from six atopic dermatitis patients . S . aureus was irradiated in vitro with UVB (0, 5, 10 mJ/cm2) or PUVA (0.001% psoralen plus 0, 5, 10 mJ/cm2 UVA) and incubated 4 h with 100 strokes per min . After incubation, the amounts of superantigens in the supernatant were measured using ELISA kit . The production of superantigens decreased in an ultraviolet dose-dependent manner . The suppressive effects of UV radiation on superantigen production may be involved in the therapeutic efficacy of photo(chemo)therapy for atopic dermatitis.

J Am Soc Nephrol, 1999 Jan, 10(1), 93 - 100
Neutrophil apoptosis and dysfunction in uremia; Cendoroglo M et al.; The high prevalence of bacterial infections among patients with end-stage renal disease suggests that "professional" phagocytes such as neutrophils are functionally impaired . This dysfunction has been ascribed to uremic toxins, malnutrition, and dialysis . The aim of this study was to investigate the contribution of apoptosis to neutrophil dysfunction in uremia . Neutrophils harvested from uremic patients (n = 6) and age-/gender-matched healthy control subjects (n = 6) were incubated with either 50% autologous plasma or 10% fetal calf serum . After 24-h incubation, apoptosis was quantified by flow cytometry by using propidium iodide nuclear staining . Neutrophils from healthy volunteers were also incubated with either 50% heterologous normal or uremic plasma . After 24-h incubation, apoptosis was quantified by flow cytometry and transmission electron microscopy . In addition, superoxide production was determined by measuring the capacity to reduce ferri- to ferro-cytochrome C by using 4-beta-phorbol 12-beta-myristate 13-alpha-acetate or N-formyl methionyl-leucyl-phenylalanine (fMLP) for stimulus . Phagocytosis was determined by the uptake of 14C-labeled heat-killed Staphylococcus aureus . Compared with normal neutrophils, uremic neutrophils demonstrated greater apoptosis in the presence of autologous plasma (9 +/- 4 versus 19 +/- 6%, P = 0.01) as well as 10% fetal calf serum (19 +/- 7 versus 31 +/- 6%, P = 0.03) . Furthermore, compared with normal neutrophils exposed to heterologous normal plasma, those exposed to heterologous uremic plasma exhibited higher apoptosis rates (19 +/- 3 versus 40 +/- 5%, P = 0.002), lower tMLP-stimulated superoxide production (22.6 +/- 2.5 versus 15.5 +/- 1.1 nmol O2*-/3.12 x 10(5) cells/30 min, P = 0.01), and a lower phagocytosis index (38 +/- 3% versus 27 +/- 5%, P = 0.04) . Apoptosis correlated inversely with fMLP-stimulated superoxide production (r = -0.60, P = 0.04) and phagocytosis (r = -0.57, P = 0.05) . These results suggest that uremic neutrophils undergo accelerated in vitro apoptosis . Furthermore, uremic plasma accelerates apoptosis of normal neutrophils, resulting in a dysfunctional pattern that is similar to that observed in uremia.

J Clin Microbiol, 1999 Feb, 37(2), 342 - 9
Molecular genotyping of Staphylococcus aureus strains: comparison of repetitive element sequence-based PCR with various typing methods and isolation of a novel epidemicity marker; van der Zee A et al.; Repetitive sequence-based (Rep)-PCR genotyping as described here is based on the presence of homologues of Mycoplasma pneumoniae repeat-like elements in Staphylococcus . In this study we comparatively evaluated the usefulness of rep-PCR typing with two sets of well-defined collections of Staphylococcus aureus strains . Rep-PCR analysis of the first collection of S . aureus strains (n = 59) and one Staphylococcus intermedius strain showed 14 different rep-PCR patterns, with each pattern harboring 6 to 15 DNA fragments . The discriminatory power of rep-PCR typing compared well to those of arbitrarily primed PCR (average of 20 types) and pulsed-field gel electrophoresis (11 types) . S . aureus strain collection I comprised four outbreak-related groups of isolates . The isolates in only one group were found to have identical rep-PCR profiles . However, in an analysis of isolates from three additional independent local outbreaks (n for outbreaks 1 and 2 = 5, n for outbreak 3 = 12), identical rep-PCR types were found among strains isolated during each outbreak . Therefore, we conclude that rep-PCR genotyping may be an easy and fast method for monitoring of the epidemiology of nosocomial Staphylococcus infections . Rep-PCR analysis of strain collection II, which consisted of epidemic and nonepidemic methicillin-resistant S . aureus (MRSA) strains, revealed that a cluster of similar rep-PCR profiles was found among MRSA isolates which were more frequently isolated and which were most often associated with outbreaks.

Eur J Med Res, 1998 Dec 16, 3(12), 546 - 8
Phagocytosis of Escherichia coli and Staphylococcus aureus by neutrophils of human immunodeficiency virus-infected patients; Schaumann R et al.; To study the influence of human immunodeficiency virus (HIV) infection on phagocytosis of Escherichia coli (E . coli) and Staphylococcus aureus (S . aureus) by polymorphonuclear neutrophils (PMN) from HIV-infected patients in vitro . PMN were isolated from the blood of 25 HIV-infected patients (group 1: CD subset4 </= 250/microL: 14 patients, group 2: CD subset4 >250/microL: 11 patients ) by Percoll density gradient and incubated with E . coli and S . aureus . Subculture technique was used to determine PMN function at 0, 0.5, 1, 2, 4, 6, and 24 hours . Controls were run with PMN from healthy volunteers . Phagocytosis of E.coli and S.aureus by PMN of HIV-infected patients was significantly lower in group 1 (p <0.05) . Reduced phagocytosis of E . coli and S . aureus was found in HIV-infected patients with low CD subset4-cell counts . Our findings may contribute to increased susceptibility to bacterial infection in HIV-infected patients with low CD subset4-cell counts.

J Cataract Refract Surg, 1999 Jan, 25(1), 65 - 71
Prospective evaluation of external ocular microbial growth and aqueous humor contamination during cataract surgery; Tervo T et al.; PURPOSE: To analyze the route of aqueous humor contamination leading to the development of postoperative endophthalmitis . SETTING: Department of Ophthalmology, University of Helsinki, Finland . METHODS: Forty-nine eyes of 49 patients (31 having phacoemulsification and 18 extracapsular cataract extraction {ECCE}) participated in the study . Four bacterial cultures were taken: preoperative conjunctival swab, lid margin culture, intraoperative lacrimal lake sample, and immediate postoperative anterior chamber fluid sample . RESULTS: Preoperative lid margin cultures were positive in 59.2% of eyes, conjunctival cultures in 69.4%, and lacrimal lake cultures in 24.9% . Four aqueous humor samples (8.2%) showed bacterial growth in the anterior chamber aspirate: 3 in the phacoemulsification and 1 in the ECCE group . The bacteria isolated in this study, Staphylococcus epidermidis and Propionibacterium acnes (2 positive isolates each) were sensitive to the preoperative topical antibiotics used . No aqueous humor sample or any from other locations showed gram-negative microbe growth . The most frequently recovered microbes in all samples collected from the 3 other sources were S epidermidis and other coagulase-negative staphylococcus species, followed by P acnes and other propionibacterium species . Staphylococcus aureus, and diptheroids . CONCLUSION: The ocular surface significantly contributed to the transmission of microbes into the eye during cataract surgery . These microbes could not be eradicated by topical preoperative antibiotics . However, no patient developed postoperative endophthalmitis . Natural defense mechanisms appear to fend off a minor inoculum with these microbes of relatively low pathogenicity.

Am J Physiol, 1999 Jan, 276(1 Pt 1), C267 - 78
Detection of local ATP release from activated platelets using cell surface-attached firefly luciferase; Beigi R et al.; We have developed a method for measuring the local concentration of ATP at the extracellular surface of live cells . This method relies on the specific attachment to the cell surface of a chimeric protein that consists of the IgG-binding domain of Staphylococcus aureus protein A fused in-frame with the complete sequence for firefly luciferase (proA-luc) . Expression of proA-luc in Escherichia coli and its one-step affinity purification are straightforward . Attachment to cells is demonstrated to be specific and antibody dependent using several suspended and adherent cell types . Light production by cell surface-attached luciferase is continuous, linearly related to ATP concentration, and sufficient to provide nanomolar sensitivity . The spatial resolution of this method enables the observation of strictly local changes in extracellular ATP during its secretion from activated platelets . Furthermore, the activity of cell-attached luciferase is relatively refractory to the inclusion of nucleotidases in the medium, arguing for its effectiveness in cell systems possessing potent ecto-ATPases.

Microbiol Immunol, 1998, 42(11), 723 - 9
Epidemiologic typing of methicillin-resistant Staphylococcus aureus in neonate intensive care units using pulsed-field gel electrophoresis; Saito Y et al.; To elucidate the mode of dissemination of methicillin-resistant Staphylococcus aureus (MRSA) in neonate intensive care units (NICUs), a total of 223 isolates from 3 separate hospitals were investigated between 1994 and 1996 by a DNA fingerprinting technique with pulsed-field gel electrophoresis (PFGE) . Exoprotein profiles of some strains were also examined using SDS-polyacrylamide gel-electrophoresis (SDS-PAGE) and the assessment of enzyme/toxin production such as coagulase, enterotoxin and TSST-1 . Judging from the strain typing data from PFGE results and the epidemiological data, 2 different types of PFGE patterns (A and B) and their subtypes (A', A'' and B') were identified . The A type including A' and A'' (comprising approximately 95% of the isolates) was markedly dominant . Only 5% of the isolates belonged to type B and subtype B' . On the other hand, MRSA isolated from adult patients admitted to the same hospital showed many different PFGE patterns . The results strongly suggested that some strain(s) with specific PFGE pattern(s) is prevalent in NICUs . Furthermore, isolates which expressed the same PFGE pattern did not always express the same SDS-PAGE pattern . There were some isolates with different abilities to produce coagulase, enterotoxin C and toxic-shock syndrome toxin (TSST)-1, and the abilities had no relation with a particular type of PFGE pattern . Therefore, a combination of PFGE analysis and biochemical analyses of coagulase, enterotoxin C and TSST-1 may provide us with more detailed information for the epidemiological study of MRSA in NICUs.

Intensive Care Med, 1998 Dec, 24(12), 1327 - 30
Outbreaks of Staphylococcus aureus infections during treatment of late onset pneumonia with ciprofloxacin in a prospective, randomized study; Manhold C et al.; We carried out a prospective, randomized four-center study in nosocomial pneumonia to evaluate the clinical and microbiological efficacy and safety of different treatment regimens in adult intensive care patients . During the randomized treatment of 18 patients with late onset pneumonia, ciprofloxacin (CIP) was compared to ceftazidim plus gentamicin (CAZ/GM), outbreaks of Staphylococcus aureus infections occurred in center 1 . This article reports the unexpected findings . In the CIP group six out of ten patients were superinfected or reinfected with ciprofloxacin-resistant pathogens at the follow-up on day 5 after treatment . Four out of these six patients were superinfected with methicillin-susceptible or methicillin-resistant S . aureus (MRSA) . Four superinfected patients died with pneumonia during treatment or before the follow-up . In the CAZ/GM group one out of eight patients was superinfected with MRSA . One patient died with pneumonia during treatment . There was no problem with multiresistant S . aureus or MRSA before the study period in center 1 . In conclusion, we observed outbreaks of S . aureus infections during the treatment of late onset pneumonia with ciprofloxacin, which were associated with a high mortality . These superinfections occurred in mechanically ventilated, postoperative cardiac surgical patients after 13 days in the intensive care unit (ICU) . We recommend combining ciprofloxacin with an antibiotic agent active against gram-positive bacteria in ventilator-associated pneumonia after a prolonged ICU stay . Selective pressure of ciprofloxacin could have played a role in these superinfections.

Diagn Microbiol Infect Dis, 1998 Nov, 32(3), 243 - 6
Molecular discrimination of enterotoxin C subtype in clinical isolates of Staphylococcus aureus; Kobayashi N et al.; The subtype of staphylococcal enterotoxin C (SEC) of 33 S . aureus clinical isolates was determined by polymerase chain reaction and direct DNA sequencing of a portion of the SEC gene encoding the SEC subtype-specific region . With the exception of a single strain with the SEC2 gene, all other strains showing different biologic and genetic properties were proved to possess the SEC3 gene.

Diagn Microbiol Infect Dis, 1998 Nov, 32(3), 159 - 63
Comparative study of BacT/Alert FAN bottles and standard BacT/Alert bottles; Gibb AP et al.; A total of 5,230 paired blood cultures were studied . One sample was divided between aerobic and anaerobic BacT/Alert standard bottles, and the other divided between aerobic and anaerobic BacT/Alert FAN bottles . There were 44 occasions where Staphylococcus aureus was recovered only from the FAN bottles, compared to six where only the standard bottles were positive (p < 0.001), and 21 occasions where Escherichia coli was isolated only from FAN bottles, compared to eight occasions where only the standard bottles were positive for this organism (p < 0.05) . In 21 of 28 cases reviewed where S . aureus was isolated from FAN bottles only the patient had been receiving anti-staphylococcal antibiotics . However, only 2 of 30 cases where Gram-negative bacilli were isolated from FAN bottles had documented recent appropriate antibiotic therapy . Patients in whom FAN bottles are more likely to recover organisms cannot be selected on the basis of documented antibiotic treatment.

Gan To Kagaku Ryoho, 1998 Dec, 25 Suppl 4, 595 - 8
{MRSA infection concured and exsited and the examination of a home cases}; Yasunaga A et al.; MRSA (methicillin-resistant Staphylococcus aureus) infection was admitted to 4 cases out of 171 cases that carried out the home medical treatment and exist to, period until to March, in 1998 with this hospital in April, in 1986 . As for age, a sex distinction was a mal whichere from 63 years old to 78 years old . A cause disease that reached to home medical treatment was brain blood vessel obstract 2 cases, spine damage 1 case, pulmonary emphysema 1 case . MRSA disappeared with many times wound treatments and a calorie by intra venous hyper alimentary increase that a bed sore cases . An intestinal case was seen a sepsis and candida, MRSA dermatitis with MRSA dermatitis . Bthing servis of it passes, start vancomycin hydrochloride administration peculiar to transnasal tube with improved . The respiratory case pass under tracheostomy tube control with balloon and the detection of MRSA is not admitting with diabetes control with mouth ingestion . It exists and as for MRSA infection the risk of severe infection concurrence is few with only settlement unlike an in hospital a home medical treatment cases with . If an enfeebled persons inside a home are paid attention rigid control is unnecessary . Most important thing are control of local area and improvement of whole body, and whole body.

Kansenshogaku Zasshi, 1998 Nov, 72(11), 1176 - 81
Antimicrobial effects of electrolytic products of sodium chloride--comparative evaluation with sodium hypochlorite solution and efficacy in handwashing; Hitomi S et al.; We examined the in vitro bactericidal effects and efficacy on handwashing of water containing electrolytic products of sodium chloride (electrolytic water) . The electrolytic water, whose pH and concentration of free residual chlorine were 6.7-6.9 and 20-22 ppm, respectively, showed equal reduction of both Staphylococcus aureus and Escherichia coli to dilution of commercially available sodium hypochlorite containing 60 ppm of free residual chlorine . This bactericidal effect was calculated to be due to hypochlorous acid, based on the pH and the amount of chlorine in solution . Handwashing with the electrolytic water reduced the numbers of S . aureus on hands by 1/10(2), while running water and 0.2% benzalkonium chloride with 80% ethanol gave a 1/10 and 1/10(5) reduction, respectively . We conclude that electrolytic water might be applicable for handwashing in place of running water.

Glycobiology, 1999 Jan, 9(1), 21 - 30
Glycosylation sites and site-specific glycosylation in human Tamm-Horsfall glycoprotein; van Rooijen JJ et al.; The N-glycosylation sites of human Tamm-Horsfall glycoprotein from one healthy male donor have been characterized, based on an approach using endoproteinase Glu-C (V-8 protease, Staphylococcus aureus ) digestion and a combination of chromatographic techniques, automated Edman sequencing, and fast atom bombardment mass spectrometry . Seven out of the eight potential N-glycosylation sites, namely, Asn52, Asn56, Asn208, Asn251, Asn298, Asn372, and Asn489, turned out to be glycosylated, and the potential glycosylation site at Asn14, being close to the N-terminus, is not used . The carbohydrate microheterogeneity on three of the glycosylation sites was studied in more detail by high-pH anion-exchange chromatographic profiling and 500 MHz1H-NMR spectroscopy . Glycosylation site Asn489 contains mainly di- and tri-charged oligosaccharides which comprise, among others, the GalNAc4 S (beta1-4)GlcNAc terminal sequence . Only glycosylation site Asn251 bears oligomannose-type carbohydrate chains ranging from Man5GlcNAc2to Man8GlcNAc2, in addition to a small amount of complex-type structures . Profiling of the carbohydrate moieties of Asn208 indicates a large heterogeneity, similar to that established for native human Tamm-Horsfall glycoprotein, namely, multiply charged complex-type carbohydrate structures, terminated by sulfate groups, sialic acid residues, and/or the Sda-determinant.

Clin Immunol, 1999 Jan, 90(1), 15 - 21
Regulation of human IL-18 mRNA expression; Marshall JD et al.; As virtually nothing is known about the pattern of expression of human IL-18, we investigated certain factors that may contribute to the regulation of IL-18 mRNA accumulation and compared this with regulation of the human gene encoding the p40 chain of IL-12, a cytokine that shares similar biologic activity with IL-18 . IL-18 mRNA was expressed constitutively in unstimulated PBMC or monocytes, unlike p40, which required induction by a stimulus . Upon stimulation, IL-18 transcript accumulation was enhanced with an earlier and more transient pattern of expression than IL-12 p40 mRNA . Bacteria-derived stimuli and priming with IFN-gamma or IL-4 also upregulated IL-18 mRNA in a fashion similar to that of IL-12 p40 . IL-10 exerted an inhibitory effect on IL-18 mRNA accumulation, though not as markedly as in the suppression of IL-12 p40 by IL-10 . Finally, unlike IL-12 p40 mRNA, the constitutive accumulation of IL-18 transcripts by unstimulated cells was amplified in the presence of the translational blocker cycloheximide, which also caused a superinduction of IL-18 expression after Staphylococcus aureus stimulation .

J Spinal Disord, 1998 Dec, 11(6), 498 - 500
Influence of antibiotics on infection in spinal surgery: a prospective study of 110 patients; Wimmer C et al.; The purpose of this prospective study was to evaluate the effect of prophylactic antibiotic treatment on postoperative antibiotic spinal wound infection after spinal surgery with instrumentation . Subjects consisted of 110 successive patients that underwent instrumented fusion with Cotrel-Dubousset (CD) or Miami Moss instrumentation . In 56 cases, the indication for surgery was painful spondylolisthesis . The remaining 54 patients were treated for idiopathic scoliosis . In total, 172 spinal procedures were performed and included in the study . Preoperative infection prophylaxis consisting of 2 g cefamandole was administered to all patients . Patients received three doses of 2 g/day cefamandole after surgery for 3 days . Follow-up ranged from 1 to 4 years . The study revealed an early infection in one (0.6%) of the 172 procedures in a patient with spondylolisthesis . A late infection occurred in one (0.6%) patient with the diagnosis of idiopathic scoliosis . In both cases, cultures were positive for Staphylococcus aureus.

Microbiology, 1998 Dec, 144 ( Pt 12), 3387 - 95
Three new members of the serine-aspartate repeat protein multigene family of Staphylococcus aureus; Josefsson E et al.; Three new genes encoding the serine-aspartate (SD) repeat-containing proteins SdrC, SdrD and SdrE were found in Staphylococcus aureus strain Newman . The SD repeats had earlier been found in the S . aureus fibrinogen-binding clumping factors ClfA and ClfB . The clfA and clfB genes encode high-molecular-mass fibrinogen-binding proteins that are anchored to the cell surface of S . aureus . The sdr genes now reported are closely linked and tandemly arrayed . The putative Sdr proteins have both organizational and sequence similarity to ClfA and ClfB . At the N-terminus, putative secretory signal sequences precede approximately 500 residue A regions . The A regions of the Sdr and Clf proteins exhibit only 20-30% residue identity when aligned with any other member of the family . The only conserved sequence is the consensus motif TYTFTDYVD . The Sdr proteins differ from ClfA and ClfB by having two to five additional 110-113 residue repeated sequences (B-motifs) located between region A and the R-region . Each B-motif contains a consensus Ca2+-binding EF-hand loop normally found in eukaryotic proteins . The structural integrity of recombinant SdrD(B1-B5) protein comprising the five B-repeats of SdrD was shown by bisANS fluorescence analysis to be Ca2+-dependent, suggesting that the EF-hands are functional . When Ca2+ was removed the structure collapsed to an unfolded conformation . The original structure was restored by addition of Ca2+ . The C-terminal R-domains of the Sdr proteins contain 132-170 SD residues . These are followed by conserved wall-anchoring regions characteristic of many surface proteins of Gram-positive bacteria . The sdr locus was present in all 31 S . aureus strains from human and bovine sources tested by Southern hybridization, although in a few strains it contained two rather than three genes.

J Virol, 1999 Feb, 73(2), 930 - 8
Chimeric plant virus particles administered nasally or orally induce systemic and mucosal immune responses in mice; Brennan FR et al.; The humoral immune responses to the D2 peptide of fibronectin-binding protein B (FnBP) of Staphylococcus aureus, expressed on the plant virus cowpea mosaic virus (CPMV), were evaluated after mucosal delivery to mice . Intranasal immunization of these chimeric virus particles (CVPs), either alone or in the presence of ISCOM matrix, primed CPMV-specific T cells and generated high titers of CPMV- and FnBP-specific immunoglobulin G (IgG) in sera . Furthermore, CPMV- and FnBP-specific IgA and IgG could also be detected in the bronchial, intestinal, and vaginal lavage fluids, highlighting the ability of CVPs to generate antibody at distant mucosal sites . IgG2a and IgG2b were the dominant IgG subclasses in sera to both CPMV and FnBP, demonstrating a bias in the response toward the T helper 1 type . The sera completely inhibited the binding of human fibronectin to the S . aureus FnBP . Oral immunization of the CVPs also generated CPMV- and FnBP-specific serum IgG; however, these titers were significantly lower and more variable than those generated by the intranasal route, and FnBP-specific intestinal IgA was undetectable . Neither the ISCOM matrix nor cholera toxin enhanced these responses . These studies demonstrate for the first time that recombinant plant viruses have potential as mucosal vaccines without the requirement for adjuvant and that the nasal route is most effective for the delivery of these nonreplicating particles.

Burns, 1998 Nov, 24(7), 631 - 6
A profile of methicillin resistant Staphylococcus aureus infection in the burn center of the Sultanate of Oman; Prasanna M et al.; A retrospective study of patterns of infection in 168 patients admitted during 1995 and 1996 in the burns-unit of Khoula hospital at Muscat, Oman was performed . Out of 819 isolates positive for pathogenic bacterial culture, there were 326 (39.8%) isolates positive for methicillin resistant Staphylococcus aureus (MRSA) infection . Incidence of MRSA infection was marginally more than that of Pseudomonas aeroginosa . The proportion of patients developing MRSA infection sometime or the other during their burns-unit stay ranging from 1 to 112 days rose from 48% in 1995 to 52.7% in 1996 . No sophisticated tests were done to identify the MRSA strain but study of the antibiograms of each MRSA positive isolate showed very similar patterns of sensitivity to different antibiotics . This suggests the source of infection to be common and in all probability 'noscomial', since all patients acquired MRSA infection in the hospital . The susceptibility of MRSA to ciprofloxacin, cotrimoxazole and fucidin was 76, 51 and 37% of isolates in 1995, and 59, 44 and 26% in 1996 were susceptible to these drugs . Vancomycin was the antibiotic to which most MRSA cultures were susceptible, but partial resistance was reported due to very low susceptibility observed in 1.4% of the isolates in 1995 and 1.1% of the isolates in 1996 . The control measures being practiced in the burns-unit of Khoula Hospital, especially mechanical cleaning and chemical disinfection of all surfaces, are discussed in detail . This paper emphasizes the need for preventive measures against MRSA infection in the burns-unit.

J Med Microbiol, 1998 Jun, 47(6), 533 - 41
Reduction in cytokine release from human monocytes by modifications in cell wall structure of Staphylococcus aureus induced by subinhibitory concentrations of oxacillin; Schmitz FJ et al.; Whole bacterial cells of Staphylococcus aureus as well as purified staphylococcal peptidoglycan (PG) have been demonstrated to stimulate human monocytes to release cytokines . Hypothesising that the phenomenon of changes induced by beta-lactam antibiotics in cell-wall composition may alter the immunological properties of the intact cell wall as well as of purified cell-wall components, this study assessed whether cytokine release by human monocytes is altered if cells from strains grown in the presence or absence of sub-minimal inhibitory concentrations of oxacillin are used as stimuli . Whole bacterial cells and isolated PG from these strains, grown in the presence of oxacillin, showed a significantly reduced stimulation of tumour necrosis factor-alpha, interleukin (IL)-1beta and IL-6 release by human monocytes in a concentration-dependent fashion . The serum-induced potentiation of cytokine production by human monocytes in response to PG with modified cross-linking was also reduced . These observations may have particular relevance for staphylococcal infections, in which clinically achievable beta-lactam concentrations do not suppress staphylococcal growth yet may alter and possibly enhance virulence.

J Med Microbiol, 1998 Feb, 47(2), 173 - 8
A retrospective molecular analysis of gentamicin resistance in Staphylococcus aureus strains from UK hospitals; Wright CL et al.; The composite transposon Tn4001 and a related chromosomal Tn4001-like element, encode resistance to the aminoglycosides gentamicin, tobramycin and kanamycin (GmTmKmr) in Australian strains of Staphylococcus aureus . Southern hybridisation analysis of GmTmKmr S . aureus strains isolated from various hospitals in the UK between 1975 and 1985 indicated that they predominantly encoded chromosomal copies of Tn4001 or a Tn4001-like element . However, a strain isolated in 1985 was found to carry Tn4001 on a plasmid related to pSK1, the prototypical multiresistance plasmid commonly detected in S . aureus strains from Australian hospitals.

J Med Microbiol, 1998 May, 47(5), 417 - 25
A collagen-binding protein produced by Aeromonas hydrophila; Ascencio F et al.; The gastrointestinal pathogen Aeromonas hydrophila strain A186 produces a collagen-binding protein (CNBP) which is found extracellularly and loosely associated with the cell surface . The cell-associated CNBP was purified by sequential ammonium sulphate precipitation, size-exclusion chromatography and ion-exchange chromatography, or by sequential ammonium sulphate precipitation and affinity chromatography with collagen-Sepharose . The purified CNBP was homogeneous in SDS-PAGE, and had a mol . wt of c . 98 kDa . Cyanogen bromide cleavage of the CNBP destroyed collagen-binding activity; however, enzymic digestion with Staphylococcus aureus V8 protease generated > 10 polypeptide fragments, from which a 30-kDa polypeptide contained the strongest collagen-binding activity . Binding of collagen by the CNBP was restricted to the alpha1 (I) chain of the collagen molecule and binding seemed to involve both the carbohydrate moieties and certain peptide sequences on the collagen . Collagen-saccharides generated by alkaline hydrolysis inhibited collagen binding by A . hydrophila . Also, glycosidase digestion and chemical alteration of the carbohydrate residues of collagen reduced its ability to be bound by the CNBP . Collagen-homologous synthetic peptides inhibited binding of 125I-collagen by the bacteria.

Drugs, 1998 Dec, 56(6), 1047 - 52; discussion 1053-4
Pexiganan acetate; Lamb HM et al.; Pexiganan acetate (MSI 78) is a synthetic cationic peptide (22 amino acids) with antibacterial activity . It is an analogue of magainin 2, which is a host defence peptide isolated from frog skin . The drug is thought to act by disturbing the permeability of the cell membrane or cell wall . Pexiganan acetate has good in vitro activity against Gram-positive and Gram-negative aerobes; 99% of strains were susceptible to the agent using a break-point of 64 mg/L . 89 to 97% of anaerobes were susceptible to pexiganan acetate using the same break-point . After 7 passages in vitro, there was no evidence of resistance to pexiganan acetate among 2 strains of Staphylococcus aureus . In 2 phase III multicentre randomised double-blind trials in diabetic patients with infected foot ulcers, both topical pexiganan acetate 1% and oral ofloxacin 800 mg/day achieved clinical cure or improvement in about 90% of patients . Eradication of pathogens in the 2 studies was achieved in 82% of ofloxacin recipients and 66% of pexiganan acetate recipients at the end of therapy . Limited data indicate that pexiganan acetate is well tolerated.

Chemotherapy, 1999 Jan-Feb, 45(1), 37 - 47
Role of inhibition of penicillin binding proteins and cell wall cross-linking by beta-lactam antibiotics in low- and high-level methicillin resistance of Staphylococcus aureus; Higashi Y et al.; We have investigated the relationships between the minimum inhibitory concentrations (MICs) of eight beta-lactams and their binding affinities of penicillin binding proteins in low- and high-level methicillin-resistant Staphylococcus aureus (MRSA) . For high-level MRSA (H-MRSA), a significant correlation was found between IC50 for PBP2A and MIC, whilst no clear relationship was apparent for low-level MRSA (L-MRSA) . However, the product of the IC50s for PBP2A and PBP4 significantly correlated with the MIC in L-MRSA . Since PBP4 is thought to mediate secondary cross-linking of the staphylococcal cell wall, we analyzed the effect on cell wall cross-linking of L- and H-MRSA of two representative drugs (cefoselis and flomoxef) . Interestingly, the decrease in cell wall cross-linking, which was clearly observed in L-MRSA, was diminished with H-MRSA . It is concluded that for L-MRSA, a reduction in cell wall cross-linking caused by inhibiton of PBP4 may contribute to the antimicrobial activity of beta-lactam antibiotics, while for H-MRSA, inhibition of PBP2A mainly determines the antimicrobial activity . Since neither alteration of expression nor binding affinity of PBP4 were observed in these studies, unknown factors must operate to diminish the effect of PBP4 inhibition and contribute to the mechanism of high level resistance of MRSA.

J Med Microbiol, 1998 Aug, 47(8), 705 - 9
The effect of culture conditions on the in-vitro adherence of methicillin-resistant Staphylococcus aureus; Van Wamel WJ et al.; Methicillin-resistant isolates of Staphylococcus aureus (MRSA) were divided on the basis of their epidemiologic behaviour into two subgroups, epidemic MRSA (EMRSA) and sporadic MRSA (SMRSA) strains . An existing adherence assay was modified to determine differences in adherence properties between these two groups of MRSA, and the influence of culture conditions on the adherence of SMRSA and EMRSA strains to plastic, human collagen I (HuCol I) and pharyngeal carcinoma Detroit 562 cells (D562) was determined . In-vitro parameters, such as culture medium, growth temperature and growth phase of the bacterium, influenced the adherence of MRSA strains to plastic significantly . Even more pronounced differences in adherence due to changes in growth conditions and growth phase of the bacteria were found for the adherence of MRSA strains to HuCol I . Growth phase had a significant effect on the adherence of MRSA strains to the pharyngeal carcinoma cells D562 . However, the study did not find conditions which made it possible to distinguish EMRSA from SMRSA strains . These data show that extrapolation of in-vitro data concerning adherence of MRSA strains to in-vivo conditions should be treated with caution.

Arch Pharm Res, 1998 Feb, 21(1), 62 - 6
Screening and isolation of antibiotic resistance inhibitors from herb materials-resistance inhibition of volatile components of Korean aromatic herbs; Lee CK et al.; The resistance inhibitory activities of 54 odorant mixtures (essential oil) from 41 Korean aromatic herbs were tested against multi-drug resistant Staphylococcus aureus SA2, which has resistances to 10 usual antibiotics including chloramphenicol . As results, combinations of 28 kinds of samples from 21 herbs and chloramphenicol have resistance inhibitory activities in dose dependent manner.

Clin Diagn Lab Immunol, 1999 Jan, 6(1), 101 - 4
Ceramidase activity in bacterial skin flora as a possible cause of ceramide deficiency in atopic dermatitis; Ohnishi Y et al.; A marked decrease in the content of ceramide has been reported in the horny layer of the epidermis in atopic dermatitis (AD) . This decrease impairs the permeability barrier of the epidermis, resulting in the characteristic dry and easily antigen-permeable skin of AD, since ceramide serves as the major water-holding molecule in the extracellular space of the horny layer . On the other hand, the skin of such patients is frequently colonized by bacteria, most typically by Staphylococcus aureus, possessing genes such as those for sphingomyelinase, which are related to sphingolipid metabolism . We therefore tried to identify a possible correlation between the ceramide content and the bacterial flora obtained from the skin of 25 patients with AD versus that of 24 healthy subjects, using a thin-layer chromatographic assay of the sphingomyelin-associated enzyme activities secreted from the bacteria . The findings of the assay demonstrated that ceramidase, which breaks ceramide down into sphingosine and fatty acid, was secreted significantly more from the bacterial flora obtained from both the lesional and the nonlesional skin of patients with AD than from the skin of healthy subjects; sphingomyelinase, which breaks sphingomyelin down into ceramide and phosphorylcholine, was secreted from the bacterial flora obtained from all types of skin at similar levels for the patients with AD and the healthy controls . The finding that the skin of patients with AD is colonized by ceramidase-secreting bacteria thus suggests that microorganisms are related to the deficiency of ceramide in the horny layer of the epidermis, which increases the hypersensitivity of skin in AD patients by impairing the permeability barrier.

Int J STD AIDS, 1998 Dec, 9(12), 726 - 30
An outbreak of methicillin-resistant Staphylococcus aureus (MRSA) infection in HIV-seropositive persons; Smith NP et al.; Staphylococcus aureus is a cause of considerable morbidity and mortality in HIV-seropositive persons . Although methicillin-resistant S . aureus (MRSA) is encountered worldwide and in many areas of medical care, little has been reported on clinical infection with MRSA in patients with HIV . We report on an outbreak of MRSA infection in HIV antibody positive patients, using case reports to describe an outbreak of MRSA infection in HIV-seropositive persons . Six cases of clinical MRSA infection were reported over a 4-week period on patients on an HIV dedicated ward . All cases had previous AIDS diagnoses and low CD4 cell counts (median 8 x 10(6)/l; range 0 to 238) . Two cases had infected skin lesions and 2 cases had infected indwelling central venous catheters with septicaemia . Two cases had pneumonia, one with concurrent infection at the entry site of a percutaneous endoscopic gastrostomy (PEG) feeding tube . Isolates of MRSA from the 6 cases were compared by pulsed-field gel electrophoresis of Sma1 chromosomal digests . The resultant banding pattern showed the same strain was responsible for all the infections . A seventh inpatient, the index case, had positive carriage with the same strain of MRSA . To define ongoing MRSA carriage after the outbreak, 29 consecutive ward patients were swabbed for MRSA: all were negative . All patients identified with MRSA infection responded to treatment with intravenous teicoplanin, although carriage was unaltered . Four of the 6 cases died within 7 weeks of diagnosis of MRSA . MRSA can cause severe morbidity in patients with end-stage HIV disease . A small outbreak of MRSA was controlled by simple precautionary measures with no subsequent ongoing transmission of MRSA.

Bioorg Med Chem Lett, 1998 Nov 3, 8(21), 3007 - 10
Nitroglycosylated meso-arylporphyrins as photoinhibitors of gram positive bacteria; Sol V et al.; Novel porphyrins bearing nitro groups and glucosyl moieties were synthesized . The antibacterial activity of these compounds on Escherichia coli and Staphylococcus aureus is described . Results reveal that their photocytotoxicity is markedly dependent on the nature, the number and the linking position of the glycosyl moieties and nitro groups controlling their amphiphilic characters.

Bioorg Med Chem Lett, 1998 Oct 20, 8(20), 2833 - 8
Synthesis and antibacterial activity of novel 7-(3-substituted-3 or 4-trifluoromethyl-1-pyrrolidinyl)-8-methoxyfluoroquinolones; Fukui H et al.; The titled compounds were synthesized and evaluated for in vitro antibacterial activity . The (3R, 4S)-3-aminomethyl-4-trifluoromethyl derivative (S-34109) was confirmed to be optimal because of its superior activity against quinolone and methicillin-resistant Staphylococcus aureus and low side effect potential.

Bioorg Med Chem Lett, 1998 Feb 3, 8(3), 221 - 6
Methyloxime-substituted aminopyrrolidine: a new surrogate for 7-basic group of quinolone; Hong CY et al.; Novel fluoroquinolones containing oxime functionalized aminopyrrolidines have been synthesized . They were found to possess potent antibacterial activities against both Gram-negative and Gram-positive organisms, including methicillin resistant Staphylococcus aureus (MRSA) . Among these compounds, LB20277 (compound 12) showed the most favorable in vivo efficacy and pharmacokinetic profile in animals . Based on these promising results, LB20277 was selected as a candidate for further evaluation.

J Appl Microbiol, 1998 Dec, 85(6), 972 - 84
Genetic analysis of the bacteriocin-encoding plasmids pRJ6 and pRJ9 of Staphylococcus aureus by transposon mutagenesis and cloning of genes involved in bacteriocin production; de Oliveira SS et al.; pRJ6 and pRJ9, small Staphylococcus aureus plasmids which code for bacteriocins, exhibited a bactericidal activity against several lactic acid bacteria and strains of Listeria monocytogenes, an important food-borne pathogen . Filter-mating experiments using plasmid derivatives tagged with either Tn551 or Tn917-lac showed that pRJ6, but not pRJ9, could be mobilized by staphylococcal conjugative plasmids . Transposon mutagenesis of both plasmids was also performed . The bacteriocin and immunity structural genes of pRJ6 are part of the same operon, which is located around co-ordinate 4.0, being transcribed from right to left . However, gene cloning experiments using a staphylococcal vector showed some evidence for the involvement of additional functions of pRJ6 in bacteriocin expression . One function involved in pRJ6 mobilization mapped around co-ordinate 5.2, and it appears to be transcribed from left to right . The bactericidal action exerted by strains harbouring pRJ9 appears to reflect the activity of at least two bacteriocins, whose combined action results in a broader spectrum of activity and in a higher antagonistic activity . Gene cloning experiments also supported these assumptions.

Nephrol Dial Transplant, 1998 Dec, 13(12), 3160 - 4
Adherence of Staphylococcus aureus isolated in peritoneal dialysis-related exit-site infections to HEp-2 cells and silicone peritoneal catheter materials; Kreft B et al.; BACKGROUND: Peritoneal catheter exit-site infections cause a relevant morbidity in peritoneal dialysis patients and are frequently caused by Staphylococcus aureus . We tested the hypothesis that adherence of exit-site-derived S . aureus to epithelial cells and peritoneal catheter silicone tubes discriminates virulent and less virulent strains . METHODS: The binding of isolated S . aureus to an epithelial cell line (HEp-2) and to silicone tubes was analyzed using light-microscopy or radioactive labeling of bacteria . RESULTS: Of 378 exit-site swabs, 99 (26%) were positive for microbial growth . S . aureus was cultured in 25 of 99 positive swabs; three of 13 swabs taken in exit-site infections grade 3 and 4 that had tested positive for S . aureus . Adherence of S . aureus from exit-site infections grade 2, 3 and 4 to Hep-2 cells did not differ from adherence of bacteria isolated from asymptomatic or moderately inflamed catheter exit sites (grade 0-2) . However, binding of S . aureus to silicone tubes was enhanced in grade 0/1 compared with grade 2-4 exit-site isolates . CONCLUSIONS: Staphylococcus aureus is an important pathogen in CAPD-related exit-site infection being isolated in about 6.6% of all exit-site swabs (and in 25% of all positive swabs) . Silicone-adhesive strains may be of more clinical significance in peritoneal dialysis patients since adhesion to silicone was increased in S . aureus strains isolated in more severe exit-site infections.

J Heart Valve Dis, 1998 Nov, 7(6), 639 - 46
In vivo efficacy of antimicrobial-coated fabric from prosthetic heart valve sewing rings; Darouiche RO et al.; BACKGROUND AND AIMS OF THE STUDY: Antimicrobial coating of medical devices has recently emerged as a potentially effective method for preventing device-related infections . The objective of this animal study was to examine in vivo the antimicrobial efficacy of prosthetic heart valve sewing ring fabric coated with: (i) silver; (ii) combined minocycline and rifampin (M/R); or (iii) combined chlorhexidine and chloroxylenol (CH/CX) . METHODS: A rabbit model of Staphylococcus aureus colonization and infection of subcutaneously implanted fabric of prosthetic heart valve sewing rings was used . Following administration of anesthesia and preoperative antibiotic prophylaxis, 0.5 x 0.5 cm samples of fabric were placed subcutaneously into the back of rabbits . Each rabbit received a total of eight samples: (i) two uncoated; (ii) two silver-coated; (iii) two M/R-coated; and (iv) two CH/CX-coated . After injecting a bacterial inoculum of 2 x 10(5) c.f.u . of S . aureus onto each implanted sample, the wounds were sutured . Rabbits were monitored daily for one week, killed and the test fabrics removed and cultured . RESULTS: Rates of device colonization, device-related infection and device-related abscess were similar between the uncoated and silver-coated devices . Devices coated with M/R were less likely to be colonized or cause device-related infection when compared with uncoated devices, and less likely to be associated with abscess formation than silver-coated devices . There was a tendency for CH/CX-coated devices to be less colonized than uncoated devices . Only M/R-coated and CH/CX-coated devices produced zones of inhibition in vitro . Implantation of M/R-coated and CH/CX-coated devices in rabbits did not result in detectable systemic concentrations of the antimicrobial coating agents . Colonization of antimicrobial-coated devices was not associated with resistant S . aureus isolates . CONCLUSIONS: These results suggest that silver-coated sewing rings may not prove to be clinically anti-infective . In contrast, antimicrobial-coated sewing rings that produce effective zones of inhibition, particularly those coated with M/R, are likely to be clinically protective.

Antimicrob Agents Chemother, 1999 Jan, 43(1), 90 - 5
In vitro activity of the ketolide HMR 3647 (RU 6647) for Legionella spp., its pharmacokinetics in guinea pigs, and use of the drug to treat guinea pigs with Legionella pneumophila pneumonia; Edelstein PH et al.; The activities of HMR 3647, HMR 3004, erythromycin, clarithromycin, and levofloxacin for 97 Legionella spp . isolates were determined by microbroth dilution susceptibility testing . Growth inhibition of two Legionella pneumophila strains grown in guinea pig alveolar macrophages was also determined . The concentrations required to inhibit 50% of strains tested were 0.06, 0.02, 0.25, 0.03, and 0.02 microg/ml for HMR 3647, HMR 3004, erythromycin, clarithromycin, and levofloxacin, respectively . BYEalpha broth did not significantly inhibit the activities of the drugs tested, as judged by the susceptibility of the control Staphylococcus aureus strain; however, when Escherichia coli was used as the test strain, levofloxacin activity tested in BYEalpha broth was fourfold lower . HMR 3647, HMR 3004, erythromycin, and clarithromycin (0.25 and 1 microg/ml) reduced bacterial counts of two L . pneumophila strains grown in guinea pig alveolar macrophages by 0.5 to 1 log10, but regrowth occurred over a 2-day period . HMR 3647, erythromycin, and clarithromycin appeared to have equivalent intracellular activities which were solely static in nature . HMR 3004 was more active than all drugs tested except levofloxacin . In contrast, levofloxacin (1 microg/ml) was bactericidal against intracellular L . pneumophila and significantly more active than the other drugs tested . Therapy studies with HMR 3647 and erythromycin were performed in guinea pigs with L . pneumophila pneumonia . When HMR 3647 was given (10 mg/kg of body weight) by the intraperitoneal route to infected guinea pigs, mean peak plasma levels were 1.4 microg/ml at 0.5 h and 1.0 microg/ml at 1 h postinjection . The terminal half-life phase of elimination from plasma was 1.4 h . All 16 L . pneumophila-infected guinea pigs treated with HMR 3647 (10 mg/kg/dose given intraperitoneally once daily) for 5 days survived for 9 days after antimicrobial therapy, as did all 16 guinea pigs treated with the same dose of HMR 3647 given twice daily . Fourteen of 16 erythromycin-treated (30 mg/kg/dose given intraperitoneally twice daily) animals survived, whereas 0 of 12 animals treated with saline survived . HMR 3647 is effective against L . pneumophila in vitro, in infected macrophages, and in a guinea pig model of Legionnaires' disease . HMR 3647 given once daily should be evaluated as a treatment for Legionnaires' disease in humans.

Antimicrob Agents Chemother, 1999 Jan, 43(1), 12 - 5
Uptake and intracellular activity of moxifloxacin in human neutrophils and tissue-cultured epithelial cells; Pascual A et al.; The penetration by moxifloxacin of human neutrophils (polymorphonuclear leukocytes {PMN}) and tissue-cultured epithelial cells (McCoy cells) was evaluated by a fluorometric assay . At extracellular concentrations of 5 mg/liter, the cellular-to-extracellular concentration ratios (C/E) of moxifloxacin in PMN and McCoy cells were 10.9 +/- 1.0 and 8.7 +/- 1.0, respectively (20 min; 37 degrees C) . The uptake of moxifloxacin by PMN was rapid, reversible, nonsaturable (at extracellular concentrations ranging from 1 to 50 microg/ml), and not affected by cell viability . The uptake of moxifloxacin was affected by external pH and the environmental temperature . The incubation of PMN in the presence of sodium fluoride, sodium cyanide, and carbonyl cyanide m-chlorophenylhydrazone significantly decreased the C/E of this agent . Neither PMN stimulation nor phagocytosis of opsonized Staphylococcus aureus significantly affected the uptake of moxifloxacin by human PMN . This agent, at concentrations of 0.5, 1, and 5 mg/liter, induced a significant reduction in the survival of intracellular S . aureus in human PMN . In summary, moxifloxacin reaches much higher intracellular concentrations within phagocytic and nonphagocytic cells than extracellular ones, remaining active inside the neutrophils.

Arch Pharm Res, 1998 Dec, 21(6), 734 - 7
Screening and isolation of antibiotic resistance inhibitors from herb materials IV-resistance inhibitors from Anetheum graveolens and Acorus gramineus; Kim H et al.; The hexane fractions from methanolic extracts of Anetheum graveolens L . (Umbelliferae) and Acorus gramineus Soland . (Araceae), revealed potent inhibitory activities against the resistance of multi-drug resistant Staphylococcus aureus SA2 when combined with ampicillin (Am) or chloramphenicol (Cm) . As active principles, carvone and the liquid mixture containing carvone from Anetheum graveolens L . and a liquid mixture mainly consisting of benzoic acid phenylmethyl ester (benzyl benzoate) from Acorus gramineus Soland, were identified . They showed resistance inhibition at the level of 20-50 micrograms/ml when combined with 100 or 50 micrograms/ml of Am or Cm, respectively.

J Ocul Pharmacol Ther, 1998 Dec, 14(6), 555 - 63
Pharmacokinetics of intravitreal vancomycin in normal and infected rabbit eyes; Coco RM et al.; The purpose of this study was to determine the pharmacokinetics governing the distribution and elimination of intravitreally injected vancomycin in normal and infected rabbit eyes . Two groups each of 36 pigmented animals were used . Group 1 served as control . In Group 2, experimental endophthalmitis was induced in the right vitreous by inoculation with Staphylococcus aureus . Once endophthalmitis developed, a vancomycin solution was injected . Four animals from each group were killed at nine time points post-injection, the vitreous and aqueous were removed, and blood samples were taken for HPLC analysis . Data analysis was performed using the RSTRIP program . The half-lives were 69 hours in normal vitreous and 14.53 hours in infected vitreous . Therapeutic drug levels were present in the vitreous 84 hours post-injection in all eyes; they were detected from 2 to 48 hours in normal aqueous but at lower levels in the infected ones . Kv and Ca/Cv ratios suggested that the primary route of elimination was across the retina and the anterior chamber in normal eyes, and via the retina in infected eyes . Results indicate that pharmacokinetic parameters change in pathological conditions, which may help establish better treatment guidelines for endophthalmitis.

Eur J Immunol, 1998 Dec, 28(12), 4418 - 23
Quiescent memory B cells in human peripheral blood co-express bcl-2 and bcl-x(L) anti-apoptotic proteins at high levels; Bovia F et al.; The anti-apoptotic proteins bcl-2 and bcl-xL seem to exhibit strictly opposite expression patterns in normal lymphoid cell differentiation stages, with bcl-2 low and bxl-xL high in immature and mature proliferating cells, the reverse being the case in recirculating quiescent cells . However, it is in fact not known whether recirculating memory cells are bcl-xL low or high . We analyzed memory (immunoglobulin isotype-switched) B cells in human peripheral blood, which were small lymphocytes in the G0 phase of the cell cycle, but proliferated better than naive B cells in response to Staphylococcus aureus Cowan I . Ex vivo these cells co-expressed bcl-2 together with bcl-xL mRNA and protein at high levels . The mcl-1 mRNA level was low . The bcl-xL mRNA level decreased during culture in medium containing fetal calf serum, which implies that it is maintained in vivo by continuous or frequent, non-mitogenic signal(s) . The high bcl-xL expression of memory B cells may be relevant with regard to their longevity and/or their capacity to undergo an accelerated secondary type immune response.

Zentralbl Bakteriol, 1998 Nov, 288(3), 373 - 81
Coagulase-negative variants of methicillin-resistant Staphylococcus aureus subsp . aureus strains isolated from hospital specimens; Mlynarczyk G et al.; At the Department of Clinical Bacteriology of Medical University of Warsaw, S . aureus strains displaying negative reactions in the coagulase tube-test were isolated with a relatively high frequency from clinical specimens . As many as seventeen of such strains all from different patients were isolated during 1994 among MRSA strains . Despite coagulase negativity all strains were positive in tests for clumping factor (CF), protein A and thermonuclease . Biochemical characteristics, phage patterns and antibiotic resistance characteristics of these strains were tested . Most of the coagulase-negative strains possessed a heterogenous type of methicillin resistance . Apart from methicillin most of them were resistant to many other antimicrobials . All were resistant to gentamicin, tetracyclines and macrolide-lincosamide-streptogramine B . An occurrence of coagulase-negative S . aureus strains may lead to problems in their identification and the necessity of an application of other methods like CF, protein A or biochemical reactions.

J Immunol, 1998 Dec 15, 161(12), 6681 - 8
Structural basis of the gp120 superantigen-binding site on human immunoglobulins; Karray S et al.; B cell superantigens (SAg) interact with normal human nonimmune Igs (Igs), independently of the light chain isotype, and activate a large proportion of the B cell repertoire . Recently, the major envelope protein of HIV-1, gp120, was found to exhibit SAg-like properties for B cells with potential pathologic consequences for the infected host . This unconventional mode of interaction contrasts with its binding to immunization-induced Abs, which requires the tertiary structure of the heavy and light chain variable regions . In this report, we have examined the structural basis of the interaction between human Igs and gp120 . We found that gp120 binding is restricted to Igs from the V(H)3 gene family and that the two V(H) genes 3-23 and 3-30, known to be overutilized during all stages of B cell development, frequently impart gp120 binding . We also provide evidence that the viral gp120 SAg can interact with only a subset of the human V(H)3+ Igs that can convey binding to the prototypic bacterial B cell SAg protein A from Staphylococcus aureus . Finally, we have identified amino acid positions present primarily in the first and third framework regions of the Ig heavy chain variable region, outside the conventional hypervariable loops, which correlate with gp120 binding . In a three-dimensional sequence-homology model, these residues partially overlap with the predicted SAg protein A binding site for V(H)3+ Igs.

West Indian Med J, 1998 Sep, 47(3), 113 - 4
Tubo-ovarian abscess after tubal ligation; Pickering KD et al.; Tubo-ovarian abscess usually results from ascending infection of the lower genital tract . In a few cases it can occur as a result of direct contamination at the time of tubal sterilization . We describe a case that presented seven years after post partum tubal sterilization, showing both acute and chronic componentsPIP: This paper presents the case of a 32-year-old woman who developed a tubo-ovarian abscess 7 years following tubal ligation via minilaparotomy . Symptoms experienced included pain, which was exacerbated by walking, and mild deep dyspareunia . Abdominal and pelvic examinations revealed pain in the left iliac fossa, cervical excitation tenderness, and an ill-defined left adnexal mass . Sonographic evaluation of the pelvis showed an irregularly shaped, cystic mass (8.0 x 4.5 x 5.3 cm) with thickened internal septations and solid parts . A left tubo-ovarian multilobulated complex mass adherent to the omentum and the pelvic side was found upon laparotomy . There was pus in the Pouch of Douglas, and the uterus was 10 weeks in size with symmetrical enlargement . The previously ligated right fallopian tube and the ovary were unremarkable . Management includes left adnexectomy, omental biopsy, and 5-day course of antibiotics against Staphylococcus aureus, which was cultured from the purulent material in the Pouch of Douglas . Tubo-ovarian abscess should be considered in diagnosing patients presenting symptoms of pelvic inflammatory disease .

Cytogenet Cell Genet, 1998, 82(3-4), 215 - 21
Optimized mitogen stimulation induces proliferation of neoplastic B cells in chronic lymphocytic leukemia: significance for cytogenetic analysis.The Tampere Chronic Lympocytic Leukemia group; Larramendy ML et al.; We tested the effects of interleukin-2 (IL-2), human recombinant tumor necrosis factor alpha (TNF-alpha), Staphylococcus aureus Cowan I (SAC), TPA, and their combinations, using a standard thymidine incorporation assay, in order to identify an optimal mitogen combination (OMC) for 24 consecutive patients with B-cell chronic lymphocytic leukemia (B-CLL) . The combination that induced the highest thymidine incorporation was chosen as the OMC for each patient . Among 14 mitogen combinations tested, there were six different OMCs, of which the most frequent was TNF-alpha + IL-2 . It was the OMC in 9 of 24 cases . The other OMCs were TNF-alpha + TPA1 (5/24), SAC + IL-2 (5/24), TPA1 + IL-2 (3/24), TPA10 + IL-2 (1/24), and TNF-alpha + TPA10 + IL-1 (1/24) . The mitogenic power of the selected OMC in each case was then evaluated both by the combination of immunophenotyping and molecular cytogenetic techniques known as MAC (Morphology, Antibody, Chromosomes) and standard chromosome analysis . After OMC stimulation, the levels of DNA synthesis and B-cell proliferation (mitotic index) were, on average, 10-fold higher than those observed after standard TPA stimulation (P < 0 . 0001) . The proportion of mitotic B cells exceeded the proportion of mitotic T cells in 70.1% of the cases after OMC stimulation . After TPA stimulation, 7.7% +/- 2.5% of all mitoses were B-cell mitoses, whereas after OMC stimulation this proportion rose to 57.9% +/- 5.3% . The frequency of clonal chromosomal aberrations increased from 46% after TPA stimulation to 79% after OMC stimulation . The clonal aberrations del(6q), del(11q), and/or del(13q) were observed in 26%, 32%, and 42% of the patients with the respective clonal chromosomal aberrations, whereas the corresponding frequencies after TPA stimulation were only 4%, 21%, and 17% . When the lineage involvement of cells with clonal chromosomal aberrations from three patients was analyzed, the aberrations were found to be restricted to B cells only, and in one patient to a minor subset of B cells . The results demonstrate that an individually chosen OMC induces a high rate of proliferation in neoplastic B cells . We found deletions in 6q, 11q, and 13q at higher frequencies than reported previously, most probably as a result of an improved mitogenic response . The identification of an optimal mitogen stimulation for each patient, prior to chromosome analysis, can well be expected to reduce the rate of false-normal results in the future . This is essential for accurate evaluation of the prognostic significance of chromosomal aberrations in B-CLL.

Am J Vet Res, 1998 Dec, 59(12), 1537 - 9
Serotyping scheme for Staphylococcus aureus isolated from cows with mastitis; Guidry A et al.; OBJECTIVE: To identify the Staphylococcus aureus capsular serotypes that are not typable, using capsular serotypes 5 and 8, which are currently used to type S aureus isolated from cows with mastitis . SAMPLE POPULATION: Milk samples (n = 273) from cows with mastitis in 178 dairy herds in California, Wisconsin, Michigan, Texas, and New York that were collected by state diagnostic laboratories and S aureus-positive milk samples collected by Veterinary Health Services in the United Kingdom (15), France (22), The Netherlands (36), and Germany (21) . PROCEDURE: Capsular serotyping of coded isolates was performed by use of direct cell agglutination and immunoprecipitation of cell extracts with antisera specific for capsular types 5 and 8 and a newly developed S aureus serotyping antiserum 336 . RESULTS: In the United States, S aureus capsular types 5 and 8 accounted for 18 and 23% of the isolates, respectively, and type 336 accounted for 59% . Percentage of capsular serotypes in European samples were as follows: type 5 = 34%, type 8 = 34%, type 336 = 30%, and nontypable = 2% . CONCLUSIONS: Serotypes 5 and 8 accounted for only 41% of S aureus isolates from US milk samples, but accounted for 70% of isolates from European milk samples . Addition of the newly developed serotyping antiserum 336 to the typing scheme accounted for 100% of US samples and 98% of European samples and will enable development of a more comprehensive S aureus vaccine.

Invest Ophthalmol Vis Sci, 1998 Dec, 39(13), 2785 - 90
Cytokine expression in a rat model of Staphylococcus aureus endophthalmitis; Giese MJ et al.; PURPOSE: To examine the ability of viable Staphylococcus aureus to induce the production of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, cytokine-induced neutrophil chemoattractant (CINC), and interferon (IFN)-gamma after intravitreal injection . METHODS: Experimental rat eyes were injected with a 25-microl volume of approximately 80 colony-forming units of viable S . aureus; control eyes received sterile saline . Eyes were graded daily for signs of clinical inflammation and were removed 6, 24, 48, and 72 hours after injection . One group was prepared for histologic analysis, and vitreous was removed from the other group for cytokine analysis, using standard enzyme-linked immunosorbent assay procedures . RESULTS: TNF-alpha, IL-1beta, CINC, and IFN-gamma were detected in experimental vitreous samples at increased levels that peaked at 24 hours . TNF-alpha, IL-1beta, and CINC declined at 48 hours, but IFN-gamma remained elevated . At 72 hours, levels returned to baseline . Statistically significant elevations of TNF-alpha, IL-1beta, and CINC were detected in experimental samples at 24, but not at 6 and 48 hours compared with levels in saline control samples (P < 0.03) . A statistically significant increase in IFN-gamma was detected at 24 and 48 hours compared with control levels (P < 0.03) . In experimental animals, clinical inflammation and inflammatory cells peaked at 24 hours, persisted at 48 hours, and began to decline thereafter . Neutrophils were the predominant inflammatory cell detected at 24 (72.3% of cells) and 48 (60.1%) hours . By 72 hours, the total number of inflammatory cells had decreased by 75.0%, and the cellular infiltrate had changed so that neutrophils equaled monocytes-macrophages . CONCLUSIONS: S . aureus induced the expression of TNF-alpha, IL-1beta, CINC, and IFN-gamma . The time course of these cytokine levels could account for the clinical inflammatory responses and the entry and decline of vitreous cells in this model of bacterial endophthalmitis.

J Clin Microbiol, 1999 Jan, 37(1), 39 - 44
Heterogeneously vancomycin-resistant Staphylococcus epidermidis strain causing recurrent peritonitis in a dialysis patient during vancomycin therapy; Sieradzki K et al.; Methicillin-resistant Staphylococcus epidermidis (MRSE) was recovered over a 2-month period from the dialysis fluid of a peritoneal dialysis (PD) patient who experienced recurrent episodes of peritonitis during therapeutic and prophylactic use of vancomycin . Characterization of five consecutive MRSE isolates by molecular and microbiological methods showed that they were representatives of a single strain, had reduced susceptibility to vancomycin, did not react with DNA probes specific for the enterococcal vanA or vanB gene, and showed characteristics reminiscent of the properties of a recently described vancomycin-resistant laboratory mutant of Staphylococcus aureus . Cultures of these MRSE isolates were heterogeneous: they contained-with a frequency of 10(-4) to 10(-5)-bacteria for which vancomycin MICs were high (25 to 50 microg/ml) which could easily be selected to "take over" the cultures by using vancomycin selection in the laboratory . In contrast, the five consecutive MRSE isolates recovered from the PD patient during virtually continuous vancomycin therapy showed no indication for a similar enrichment of more resistant subpopulations, suggesting the existence of an "occult" infection site in the patient (presumably at the catheter exit site) which was not accessible to the antibiotic.

Proteins, 1998 Dec 1, 33(4), 550 - 7
The slow step of folding of Staphylococcus aureus PC1 beta-lactamase involves the collapse of a surface loop rate limited by the trans to cis isomerization of a non-proline peptide bond; Wheeler KA et al.; We wished to test the hypothesis that the non proline cis to trans isomerization of the peptide bond at position 167 in the S . aureus beta-lactamase PC1 exerts a significant controlling effect on the folding pathway of this enzyme . The previous data presented in support of this hypothesis could not rule out the effect of factors unrelated to non-proline cis/trans isomerization . We have used the plasmid pET9d to direct soluble overproduction of the S . aureus beta-lactamase PC1 and a site-directed mutant (Ile 167 to Pro) in Escherichia coli . Following purification the proteins were subjected to a comparative analysis of the kinetics of unfolding and refolding using the techniques of near- and far-UV circular dichroism spectroscopy and fluorescence spectroscopy in conjunction with "double-jump" experiments . Results show that the fully-unfolded I167P mutant enzyme retains 20% of molecules in a fast-refolding form and that slower-refolding molecules fold faster than the recombinant wild-type enzyme . The final stage of folding involves folding of the omega-loop into a conformation essential for enzymatic activity . In support of the original hypothesis, the folding of this omega-loop is rate limited by the isomerization of the Glu 166-Ile 167 peptide bond.

J Am Geriatr Soc, 1998 Dec, 46(12), 1555 - 7
Prevalence and outcome of methicillin-resistant Staphylococcus aureus colonization in two nursing centers in Georgia; Rahimi AR; OBJECTIVES: To evaluate the cost-effectiveness and validity of aggressive diagnosing and eradication of methicillin-resistant Staphylococcus aureus (MRSA) colonization . DESIGN: An observational study of MRSA colonization . SETTING: Two skilled nursing facilities in Georgia . PARTICIPANTS: Eighty-seven residents of the above-mentioned skilled nursing facilities INTERVENTION: No changes were made in either nursing facility practices or patient treatments . MEASUREMENTS: The presence or absence of MRSA colonization was determined at the beginning of the study, after hospitalizations or absences from the facility, and 12 months after initial testing . RESULTS: Eighty-seven participants began the study, and 56 completed it . At the beginning of the study, 17.9% of the 56 who later completed the study were positive for MRSA . By the end of the study, colonization had decreased to 14.3% . The difference in the number of positive cultures for residents returning from the hospital compared with those returning from non-hospital settings was not statistically significant (P = .546) . No deaths or hospitalizations were attributable to MRSA infection . CONCLUSION: Because no significant correlation was found between MRSA colonization and active MRSA-related infections, patients colonized by MRSA should not be barred from admission to nursing homes.

Ther Drug Monit, 1998 Dec, 20(6), 612 - 8
Population pharmacokinetics of vancomycin in Japanese pediatric patients; Yasuhara M et al.; The population pharmacokinetic profile of vancomycin (VCM) in Japanese pediatric patients infected with methicillin-resistant Staphylococcus aureus was analyzed using 181 samples of serum concentration data from 49 patients obtained in routine drug monitoring . The one-compartment linear model was adopted, where the VCM clearance (CL) and the distribution volume (Vd) were correlated with covariates such as postnatal age (AGE) and body weight (BWT) . The population pharmacokinetic analysis program NONMEM with the first-order conditional estimation method was used . The results showed that the population mean clearance normalized by BWT increases with AGE up to 1 year of age {CL(L/hour per kg) = 0.1 19 + 0.0619 x (AGE - 1)} and decreases with age over 1 year old {CL(L/hour per kg) = 0.119 + 0.00508 x (1 - AGE)} . The population mean of the distribution volume normalized by BWT was independent of AGE (Vd (L/kg) = 0.522) . The interindividual variability of CL was 39.6%, and that of Vd was 18.8% . The intraindividual, residual variability was 34.6% . These results were compared with those in other articles, and a guideline for dosage adjustment in VCM therapy is discussed.

J Vet Med Sci, 1998 Nov, 60(11), 1281 - 3
Production of exfoliative toxin A by Staphylococcus aureus isolated from mastitic cow's milk and farm bulk milk; Hayakawa Y et al.; The production of exfoliative toxins A and B (ETA and ETB) by Staphylococcus aureus isolated from mastitic cow's milk and farm bulk milk was examined by the reverse passive latex agglutination method (RPLA) . ETA was detected in 2 (1.2%) of 162 isolates from mastitic cow's milk and in 1 (0.6%) of 166 isolates from farm bulk milk . RPLA titers of these isolates were much lower than in human isolates . No ETB was detected in any of the isolates tested . These ETA-positive isolates belonged to bovine ecovar . They were non-typable using the international phage set for human strains . When these ETA-positive isolates were subcutaneously inoculated into neonatal mice, general exfoliation of the epidermis accompanied by the so-called Nikolsky sign was not recognized . By the immunoblotting and PCR methods, however, ETA and eta gene were recognized in the ETA-positive isolates from mastitic cow's milk and farm bulk milk . These data suggest that ETA is also produced by bovine isolates of S . aureus, but in smaller quantities.

Rev Assoc Med Bras, 1998 Oct-Dec, 44(4), 263 - 8
{Effect of nosocomial bacteremia caused by oxacillin-resistant Staphylococcus aureus on mortality and length of hospitalization}; Moreira M et al.; OBJECTIVES: To identify the attributed mortality rate of bloodstream hospital infection by Staphylococcus aureus resistant to methicillin (MRSA) and its effect on length of hospital stay . DESIGN: Case-control study . SETTING: Hospital Sao Paulo da Universidade Federal de Sao Paulo, a 660-bed, tertiary-care teaching hospital in Sao Paulo, Brazil . PATIENTS: Seventy one adults patients with hospital-acquired MRSA bacteremia diagnosed between January 1, 1991, and September 30, 1992, and 71 MRSA-free controls were matched by the following criteria: age, sex, underlying disease, surgical procedure, same risk time and admission date . RESULTS: The incidence of patients with hospital sepsis by MRSA accounted for 73.22% of the patients with hospital bloodstream infection by Staphylococcus aureus . The mortality rate of the cases was 56.33 (40/71) and 11.26 (8/71) of the controls . The attributable mortality rate was 45.07% (OR = 17.0; IC 95% = 3.58-202.26; p = 0.000001) . The length of hospital stay median time was of 32.55 days for the cases and 29.75 for the controls (p = 0.32) . CONCLUSION: A high level of sepsis by MRSA was observed in all the Staphylococcus aureus bacteremia . The bloodstream hospital infection by MRSA itself does provide a high level of mortality independently from the patients base disease, without however, increasing their hospital length of stay.

J Bacteriol, 1998 Dec, 180(24), 6642 - 8
A putative multisubunit Na+/H+ antiporter from Staphylococcus aureus; Hiramatsu T et al.; We cloned several genes encoding an Na+/H+ antiporter of Staphylococcus aureus from chromosomal DNA by using an Escherichia coli mutant, lacking all of the major Na+/H+ antiporters, as the host . E . coli cells harboring plasmids for the cloned genes were able to grow in medium containing 0.2 M NaCl (or 10 mM LiCl) . Host cells without the plasmids were unable to grow under the same conditions . Na+/H+ antiport activity was detected in membrane vesicles prepared from transformants . We determined the nucleotide sequence of the cloned 7-kbp region . We found that seven open reading frames (ORFs) were necessary for antiporter function . A promoter-like sequence was found in the upstream region from the first ORF . One inverted repeat followed by a T-cluster, which may function as a terminator, was found in the downstream region from the seventh ORF . Neither terminator-like nor promoter-like sequences were found between the ORFs . Thus, it seems that the seven ORFs comprise an operon and that the Na+/H+ antiporter consists of seven kinds of subunits, suggesting that this is a novel type of multisubunit Na+/H+ antiporter . Hydropathy analysis of the deduced amino acid sequences of the seven ORFs suggested that all of the proteins are hydrophobic . As a result of a homology search, we found that components of the respiratory chain showed sequence similarity with putative subunits of the Na+/H+ antiporter . We observed a large Na+ extrusion activity, driven by respiration in E . coli cells harboring the plasmid carrying the genes . The Na+ extrusion was sensitive to an H+ conductor, supporting the idea that the system is not a respiratory Na+ pump but an Na+/H+ antiporter . Introduction of the plasmid into E . coli mutant cells, which were unable to grow under alkaline conditions, enabled the cells to grow under such conditions.

Vet Microbiol, 1998 Oct, 63(2-4), 275 - 81
The use of pulsed field gel electrophoresis to investigate the epidemiology of Staphylococcus aureus infection in commercial broiler flocks; McCullagh JJ et al.; Pulsed field gel electrophoresis (PFGE) analysis of SmaI restriction patterns was used to type 109 isolates of Staphylococcus aureus collected from broiler farms and hatcheries in Northern Ireland . Forty-seven isolates from clinical conditions in broilers and 62 strains from hatcheries, were examined . The PFGE patterns demonstrated a similarity between 85% of strains from clinical sources and 71% of the hatchery isolates . The association of disease with the predominant strain type and presence of these same strains in the hatchery, indicates that the hatchery is a potential source of the infection for clinical broiler disease.

Vet Microbiol, 1998 Oct, 63(2-4), 177 - 87
Influence of pig age on virus titer and bactericidal activity of porcine reproductive and respiratory syndrome virus (PRRSV)-infected pulmonary intravascular macrophages (PIMs); Thanawongnuwech R et al.; Twelve pigs (six 4-week-old and six 4-month-old cross-bred, specific pathogen free pigs) were used as donors for both pulmonary intravascular macrophages (PIMs) and pulmonary alveolar macrophages (PAMs) . The PIMs and PAMs were infected in vitro with low (ISU-55) or high (VR-2385) virulence strains of PRRSV at 1 multiplicity of infection (m.o.i.) for comparisons of virus titers at 48 h post infection (PI) . PIMs were as permissive as PAMs to infection with both PRRSV isolates yielding similar progeny titers (10(4.81) vs . 10(5.22) TCID50/ml, respectively) . Both ISU-55 and VR-2385 were able to infect PIMs and no significant difference in virus replication as measured by virus titers between isolates was found (10(5.33) vs . 10(4.69) TCID50/ml, respectively) . PIMs from 4-weak-old pigs yielded a higher virus titer following PRRSV infection than PIMs from 4-month-old pigs (10(5.43) vs . 10(4.59) TCID50/ml, respectively; p < 0.02) . VR-2385-infected PIMs had significantly decreased bactericidal (Staphylococcus aureus) activity compared with uninfected PIMS at 48 h PI (p < 0.05) . There was no difference in bactericidal activity between ISU-55 (low virulence)-infected PIMs and VR-2385 (high virulence)-infected PIMs . Both ISU-55 and VR-2385 infection significantly decreased the production of superoxide anion (SOA) at 24 and 48 h PI (p < 0.01) . In conclusion, (1) PRRSV had a detrimental effect on bactericidal activity and SOA production of PIMs, (2) PIMs from younger pigs were more permissive to PRRSV infection, and (3) the selected PRRSV strains, which differ in their abilities to induce pneumonia in vivo were not different when tested in vitro by measuring virus titer and bactericidal functions.

Antonie Van Leeuwenhoek, 1998 May, 73(4), 327 - 30
Inter-strain comparison by pyrolysis mass spectrometry of Staphylococcus aureus isolates associated with nosocomial infection; Sisson PR et al.; Pyrolysis mass spectrometry was used to characterise Staphylococcus aureus isolates from an outbreak of postoperative wound infections on a mixed surgical ward . The PyMS results were compared with those of phage typing . Both suggested a single strain of S . aureus, of phage type 3C, 55, 71, was responsible for six of the 13 wound infections . PyMS differentiated an isolate from a member of staff of similar phage type to the epidemic strain, which had previously been considered to be the point source for the outbreak . PyMS is a rapid and inexpensive technique for investigating nosocomial outbreaks, including those caused by S . aureus and, in this instance, was more discriminatory than phage typing.

J Leukoc Biol, 1998 Dec, 64(6), 835 - 44
Bacterial phagocytosis activates extracellular signal-regulated kinase and p38 mitogen-activated protein kinase cascades in human neutrophils; McLeish KR et al.; The hypothesis that bacterial phagocytosis by human polymorphonuclear neutrophils (PMNs) stimulates MAPK cascades that regulate respiratory burst activation was tested . Extracellular response kinase (ERK) and p38 kinase, but not c-Jun NH2-terminal kinase, activities were increased within 5 min of phagocytosis of plasma-opsonized Staphylococcus aureus (S-SA), reached maximum at 20-30 min, and remained elevated through 60 min . The role of Fcy receptors was examined using gamma globulin-opsonized SA (IgG-SA), whereas CR3 receptors were activated by particulate beta-glucan . IgG-SA stimulated a maximal ERK activity at 30 min, whereas p38 activity was maximal at 5 min . Beta-glucan stimulated maximal ERK activity at 5 min and maximal p38 activity at 2 min . Non-opsonized bacteria were ingested at 10% of the level of S-SA and stimulated a minimal increase in ERK and p38 activity at 60 min . S-SA stimulation of ERK was inhibited by wortmannin, LY294002, and genistein, but not calphostin C; whereas p38 stimulation was inhibited by calphostin C and genistein, but not wortmannin and LY294002 . Simultaneous measurement of phagocytosis and H2O2 production by flow cytometry was used to assess the role of ERKs and p38 kinase in phagocytosis . The MEK inhibitor PD098059 had no significant effect on phagocytosis or H2O2 production . The p38 kinase inhibitor SB203580 significantly attenuated H2O2 production, whereas phagocytosis was unaffected . In conclusion, bacterial phagocytosis stimulates ERK and p38 activation by distinct signal transduction pathways . Phagocytosis-stimulated p38 kinase activity is necessary for optimal H2O2 production.

J Antimicrob Chemother, 1998 Nov, 42(5), 597 - 603
Accumulation of rifampicin by Escherichia coli and Staphylococcus aureus; Williams KJ et al.; A centrifugation method was used to investigate the accumulation of 14C-rifampicin by Staphylococcus aureus and Escherichia coli, and to characterize the mechanism of rifampicin transport into S . aureus . For both species, drug accumulation was rapid with the steady-state concentration (SSC) reached within 40 s of drug exposure . Rifampicin accumulation by S . aureus was temperature and pH dependent; the lower the experimental temperature and the lower the experimental pH, the lower was the concentration of rifampicin accumulated . Accumulation was unaffected by the presence of inhibitors of antibiotic efflux, carbonyl cyanide m-chlorophenylhydrazone (CCCP), dinitrophenol (DNP), or reserpine . Exposure to increasing concentrations of rifampicin suggested that the accumulation process was saturable above a rifampicin concentration of 0.2 mg/L . Michaelis-Menten kinetics gave an apparent Km and Vmax for rifampicin, calculated from a Lineweaver-Burk plot, of 0.05 mg/L (0.06 microM) and 3.8 ng rifampicin per second, respectively . However, calculations suggest that these values reflect those for binding of rifampicin to its target, RNA polymerase.

J Antimicrob Chemother, 1998 Nov, 42(5), 577 - 83
Evaluation of disc diffusion and Etest for determining the susceptibility of Staphylococcus aureus to mupirocin; Palepou MF et al.; The susceptibilities to mupirocin of 102 selected clinical isolates of Staphylococcus aureus and of control strain S . aureus NCTC 6571 were determined by disc diffusion (using discs containing 5, 15, 25, 30, 50 and 200 microg of mupirocin) and Etest and the results were compared with MICs determined using an agar incorporation method . On the basis of agar incorporation MICs, 42 isolates were sensitive to mupirocin (MIC < or = 4 mg/L), 39 showed low-level resistance (MICs = 8-128 mg/L) and 22 were highly resistant (MICs > or = 256 mg/L) and contained the mupA resistance gene . Using Stokes' criteria, none of the discs used gave major errors (sensitive isolates classified as highly resistant) or very major errors (highly resistant isolates classified as sensitive) in assigning a category of susceptibility, but minor errors (a difference of one category) were noted with all strengths . The best correlation with agar incorporation MIC was obtained with 25 microg mupirocin discs, which classified correctly 98 (95%) isolates, while worse correlations were noted with 5 microg and 200 microg discs which are the only types currently available commercially, for which there were 47 and 30 minor errors, respectively . The MICs found by Etest were the same as, or lower than, those determined by agar incorporation . Etests classified correctly all 42 mupirocin-sensitive isolates, 19 (49%) low-level resistant isolates and 16 (73%) highly resistant isolates . Two isolates that contained the mupA gene and showed agar incorporation MICs of 256 mg/L and 512 mg/L were not classified as highly resistant by any of the diffusion methods used . Agar incorporation MIC determination, possibly supported by detection of the mupA gene, offers the most effective means of identifying high-level mupirocin resistance in S . aureus, although the Etest also proved to be reproducible . However, we conclude that 25 microg discs warrant further evaluation for possible use in clinical laboratories, as they appear to be more reliable than the discs currently available.

Int J Immunopharmacol, 1998 Nov, 20(11), 595 - 614
Enhanced clearance of a multiple antibiotic resistant Staphylococcus aureus in rats treated with PGG-glucan is associated with increased leukocyte counts and increased neutrophil oxidative burst activity; Liang J et al.; PGG-Glucan {Betafectin}, a highly purified soluble beta-(1-6)-branched beta-(1 3)-linked glucan isolated from Saccharomyces cerevisiae, has broad in vitro and in vivo anti-infective activities unrelated to cytokine induction . Here we present in vivo results on the anti-infective activity of PGG-Glucan against a multiple antibiotic resistant Staphylococcus aureus . PGG-Glucan (0.25-4 mg/kg) was administered intramuscularly to male Wistar rats 48 h, 24 h, and 4 h before and 4 h after intraperitoneal implantation of a gelatin capsule containing 10(8)S . aureus colony forming units (CFU) . Blood samples were collected at various times after challenge to determine CFU levels, leukocyte counts and neutrophil oxidative burst activity; serum TNF-alpha, and IL-1beta levels were also evaluated . The 0.25 mg/kg PGG-Glucan dose had no effect on reducing blood CFU levels; however, PGG-Glucan doses of 0.5 mg/kg, 1 mg/kg, 2 mg/kg or 4 mg/kg significantly reduced blood CFU levels by 48 h after challenge . Reduced CFU levels correlated with significantly elevated absolute monocyte counts, absolute neutrophil counts, and neutrophil oxidative burst activity in the absence of any effect on TNF-alpha or on IL-1beta levels . In additional studies, effects on mortality and blood CFU levels were evaluated in rats treated with ampicillin (an antibiotic to which the S . aureus was resistant), PGG-Glucan, or both agents . Mortality and blood CFU levels were reduced most in combination-treated rats compared to saline control rats or rats treated with either ampicillin alone or PGG-Glucan alone . We conclude that in vivo (1) PGG-Glucan can enhance clearance of an antibiotic resistant S . aureus, (2) that this clearance is accompanied by an increase in monocytes and neutrophils as well as a potentiation of neutrophil oxidative microbiocidal activity without alteration of the proinflammatory cytokine response, and (3) PGG-Glucan can enhance the effectiveness of traditional antibiotic treatment.

Kansenshogaku Zasshi, 1998 Oct, 72(10), 1035 - 40
{Analysis of utility of the phenotyping method on detection of cases infected by multiple strains of methicillin-resistant Staphylococcus aureus (MRSA)}; Sawai T et al.; In this study, we compared the types of methicillin-resistant Staphylococcus aureus (MRSA) isolated from several foci of the same patient to find the incidence of multiple strain infection of MRSA in bacteremia cases . We will also evaluate the utility of the typing methods of phenotyping and genotyping for the above mentioned objective and judge the dissimilarity of clinical characteristics between the single strain infection and multiple strains infection . We studied 21 cases of MRSA bacteremia who were culture-positive both from blood and other foci in the same patient at Nagasaki University Hospital during 1990-1994 . Clinical data were retrospectively collected from the patients' records . Phenotyping of all 113 MRSA isolates were done by coagulase typing (I-VIII), production of enterotoxins (SEA-SED) and toxic shock syndrome toxin-1 (TSST-1), hemolysis typing and antibiogram (MIC) . In addition, typing of the same isolates were done by Pulsed-Field Gel Electrophoresis (PFGE), using Gene Navigator System as the genotyping . Several types of MRSA were found from different foci in the same patient in 8 of 21 cases (38%) by phenotyping . The same typing results were obtained in 7 of 8 the multiple strains isolated cases by PFGE . Two types were obtained from another case by phenotyping, but by PFGF, 3 types were obtained . We consider that phenotyping method is convenient and reliable for judgment of the difference in types isolated from different foci in the same patient, but PFGE possibly provide us more detailed epidemiological information . The epidemiological investigation must be done very carefully, especially in immunocompromised hosts as MRSA bacteremia cases, because the chance of multiple strains infection is relatively high among these cases.

Microbiology, 1998 Nov, 144 ( Pt 11), 3159 - 69
Isolation and characterization of Staphylococcus aureus starvation-induced, stationary-phase mutants defective in survival or recovery; Watson SP et al.; Ten Staphylococcus aureus mutants, defective in the starvation-induced stationary phase of growth were isolated from two independent Tn917-LTV1 transposon insertion libraries and were designated suv as they had apparent survival defects . Seven of these mutants were defective under amino-acid-limiting conditions alone . Two mutants (suv-3 and suv-20) demonstrated lower plating efficiency when starved for glucose, phosphate or amino acids and one mutant (suv-11) had reduced plating efficiency after amino acid or glucose starvation . All of the mutants tested were as resistant to hydrogen peroxide assault as the parent, but six were more sensitive to low pH conditions . All the mutants were physically mapped on the S . aureus chromosome using PFGE . Chromosomal DNA flanking the Tn917-LTV1 insertion sites was rescued by cloning into Escherichia coli . DNA sequence analysis resulted in the identification of a number of transposon-disrupted ORFs encoding putative components such as superoxide dismutase (suv-1), haem A synthase (suv-3), a component of the SOS response (suv-9) and hypoxanthine-guanine phosphoribosyltransferase (suv-20) . The Tn917-LTV1 insertion created lacZ transcriptional fusions for some of the stationary-phase loci . Expression analysis indicated that suv-4 was induced at mid-exponential phase, whereas suv-3 and suv-11 were induced at the onset of stationary phase . The possible roles of these suv components in stationary-phase survival or recovery is discussed.

Wound Repair Regen, 1998 Sep-Oct, 6(5), 449 - 56
Single local instillation of Staphylococcus aureus peptidoglycan prevents diabetes-induced impaired wound healing; Qiu JG et al.; Diabetes-induced impaired wound healing is characterized by inhibition of the inflammatory response to wounding, macrophage infiltration, angiogenesis, fibroplasia, reparative collagen accumulation, and wound breaking strength . Because all of these processes are accelerated in normal rats by a single local application at operation of Staphylococcus aureus peptidoglycan, we hypothesized that S . aureus peptidoglycan would prevent diabetes-induced impaired wound healing, despite persistent, untreated hyperglycemia, polydipsia, glycosuria, and polyuria . Sprague- Dawley male rats were divided into two groups . One group received an intraperitoneal injection of streptozotocin (65 mg/kg) in citrate solution; the other group received an intraperitoneal injection of an equivalent volume of citrate solution . Seventeen days after the injections, the diabetic and control rats received aseptically two 5.5-cm paravertebral incisions and subcutaneous implantation of six polyvinyl alcohol sponges, three on each side . On one side, each sponge contained 0.5 mg S . aureus peptidoglycan in 50 microliter saline solution, and the incision was inoculated along its length with 4.7 mg S . aureus peptidoglycan in 157 microliter saline solution (860 microgram/S . aureus peptidoglycan/cm incision); on the other side, the same respective volumes of saline were used . During the preoperative and postoperative periods, diabetic rats lost a small amount of weight (2%), were hyperglycemic (363 +/- 10 mg/100 ml blood), polydipsic, glycosuric, and polyuric, whereas the controls gained weight (25%) and were normoglycemic (104 +/- 5 mg/100 ml blood); these differences were significantly different (p <.001 in each case) . In controls, S . aureus peptidoglycan inoculation increased wound breaking strength (by a factor of 2.0) and hydroxyproline content (by a factor of 1.4; p <.001 in each case); in diabetics, there were significant decreases in wound breaking strength (by a factor of 1.7) and hydroxyproline content (by a factor of 1.3) of saline solution-inoculated incisions and sponges compared with the wound breaking strength and hydroxyproline content of saline solution-inoculated incisions and sponges in controls (p <.02 and p <.001, respectively) . These decreases were completely prevented when the incisions and polyvinyl alcohol sponges had been inoculated at operation with S . aureus peptidoglycan; S . aureus peptidoglycan inoculation in the diabetic rats increased wound breaking strength by a factor of 2.2 and sponge reparative tissue hydroxyproline by a factor of 1.6 (p <.001 in each case) . Thus, diabetes-induced impaired wound healing was prevented completely by a single local instillation at operation of S . aureus peptidoglycan, despite persistent, untreated hyperglycemia, polydipsia, polyuria, and glycosuria.

Kidney Int, 1998 Nov, 54(5), 1684 - 9
Incidence and outcome of Staphylococcus aureus bacteremia in hemodialysis patients; Marr KA et al.; BACKGROUND: Staphylococcus aureus bacteremia is frequently associated with metastatic complications and infective endocarditis (IE) . The Duke criteria for the diagnosis of IE utilize echocardiographic techniques and are more sensitive than previous criteria . The documentation of IE in patients undergoing hemodialysis (HD) has become increasingly important in order to avoid the overuse of empiric vancomycin and the emergence of antibiotic resistance . METHODS: Patients who developed S . aureus bacteremia while undergoing HD at a tertiary medical center or one of four affiliated outpatient HD units were identified . Clinical outcome (death, metastatic complications, IE, and microbiologic recurrence) was assessed during hospitalization and at three months after discharge . Transthoracic and transesophageal echocardiograms were performed and the Duke criteria were used to diagnose IE . Pulse field gel electrophoresis was performed to confirm genetic similarity of recurrent isolates . RESULTS: Four hundred and forty-five patients underwent hemodialysis for 5431.8 patient-months . Sixty-two developed 65 episodes of S . aureus bacteremia (1.2 episodes/100 patient-months) . Complications occurred in 27 (44%) patients . Bacteremia recurred in patients who dialyzed through polytetrafluorethylene grafts (44.4% vs . 7.1%, P = 0.0.01), and there was a trend to increased recurrence in patients who received only vancomycin (19.5% vs . 7.1%, P = 0.4) . IE was diagnosed in 8 patients (12%), six of whom had normal transthoracic echocardiograms . CONCLUSIONS: Sensitive echocardiographic techniques and the Duke criteria for the diagnosis of IE should be used to determine the proper duration of antibiotic therapy in hemodialysis patients with S . aureus bacteremia . This diagnostic approach, coupled with early removal of hardware, may assist in improving outcomes.

EMBO J, 1998 Dec 1, 17(23), 6854 - 62
Characterization of intermediates in the process of plant peroxisomal protein import; Pool MR et al.; A hybrid protein in which the immunoglobulin G-binding domain of Staphylococcus aureus protein A replaced the N-terminal 43 amino acids of glycolate oxidase (a peroxisomal protein) was affinity purified after expression in Escherichia coli and used to study peroxisomal protein import in vitro . The fusion protein, which co-purifies with the bacterial chaperones dnaK and groEL, binds to glyoxysomes and is partially translocated in an ATP-dependent reaction which is independent of eukaryotic cytosol . Both binding and translocation are dependent upon the amount of glyoxysomes present . The partially translocated species has a transmembrane location and is extractable by salt, indicating that it is held in the membrane by ionic interactions . In the absence of ATP, the fusion protein binds to the surface of the glyoxysomes and competes the binding of authentic matrix proteins . The surface-bound protein can be chased to the transmembrane species upon the addition of ATP . These results indicate that the surface-bound form is a true translocation intermediate . The availability of this fusion protein in milligram quantities offers the possibility to use the intermediate formed in the absence of ATP and the transmembrane species to probe interactions with the peroxisome import machinery.

J Am Acad Dermatol, 1998 Dec, 39(6), 975 - 81
Incidence of postoperative infection or positive culture after facial laser resurfacing: a pilot study, a case report, and a proposal for a rational approach to antibiotic prophylaxis; Ross EV et al.; BACKGROUND: Laser skin resurfacing (LSR) has emerged as a popular procedure for facial rejuvenation; however, there are no clear guidelines regarding systemic antibiotic prophylaxis . OBJECTIVE: We attempt to provide practical guidelines for antibiotic prophylaxis in LSR based on our experiences, pharmacology, and a review of the literature . METHODS: In a pilot study, four consecutive full-face LSR patients were treated without oral or topical antibiotics . The next four patients received oral prophylaxis with a narrow spectrum antibiotic . We also report the case of a severe gram-negative infection after LSR . RESULTS: For full-face LSR, 2 of 4 consecutive patients without antibiotic prophylaxis experienced focal Staphylococcus aureus infection . The next 4 consecutive patients, who had received gram-positive oral prophylaxis, were all culture negative after 2 days . All test sites (5 of 5) were culture negative despite the absence of systemic or topical antibiotics . One patient not in the pilot study receiving gram-positive antibiotic prophylaxis experienced a gram-negative infection . CONCLUSION: We recommend narrow-spectrum gram-positive oral antibiotic coverage for full-face and regional LSR.

Minerva Urol Nefrol, 1998 Sep, 50(3), 179 - 83
{Infections from extemporaneous catheters for hemodialysis . Experience in a center}; Ottone S et al.; BACKGROUND AND AIMS: This study reports a retrospective evaluation of the predominance of infection in 67 dual lumen central venous catheters (CVC), 35 of which were positioned in the femoral vein by the nephrological team and 32 in the subclavian vein by anesthetists . METHODS: The microorganisms responsible for infection, the prevalence of clinically symptomatic infections, the relationship between CVC-correlated infection and the time the catheter remained inserted were evaluated, together with a comparison between the two different insertion sites . RESULTS: Culture tests, performed using Maki's semiquantitative technique, gave positive results in 16/67 (23.8%) cases . The main pathogenic agents found were Staphylococcus epidermidis (37.5%) and Staphylococcus aureus (31.2%) . In 3/16 cases (18.78%) infections were clinically symptomatic . The mean permanence of CVC with positive cultures was not statistically different to the mean permanence of CVC with negative cultures (22.44 +/- 13.48 vs 18.38 +/- 17.76) . The microorganisms isolated on femoral and subclavian catheters showed a comparable distribution and the prevalence of infection was not statistically different in the two insertion sites . CONCLUSIONS: In conclusion, in the absence of infection, the authors tend to keep working catheters in the site, thus avoiding repeated invasive manoeuvres for replacement and/or repositioning, whereas in the presence of suspected systemic infection they feel it is more prudent to remove the CVC without waiting for the results of the hemoculture, starting first empiric and then specific antibiotic treatment on the basis of the antibiogram.

Biochem J, 1998 Dec 15, 336 ( Pt 3), 625 - 30
Cholesterol relieves the inhibitory effect of sphingomyelin on type II secretory phospholipase A2; Koumanov KS et al.; Secretory type II phospholipase A2 (sPLA2) is inhibited by sphingomyelin (SPH); cholesterol either mixed with the model glycerophospholipid substrate or added to the assay medium as separated liposomes counteracts this inhibition efficiently . The inhibition of fatty acid release assayed by quantitative gas chromatography-MS is observed when SPH is added to erythrocyte membranes as the substrate instead of a readily hydrolysable phosphatidylethanolamine/phosphatidylserine model mixture . Hydrolysis of SPH by Staphylococcus aureus sphingomyelinase suppresses its inhibitory potency . The addition of cholesterol to SPH liposomes with a 1:1 stoichiometry relieves completely the inhibition of sPLA2 exerted by SPH . The mechanism of inhibition suggested by the binding assay is that sPLA2 binds with affinity to the SPH interface, after either phase segregation at the assay temperature or on the pure SPH liposomes added to the incubation medium . Cholesterol is shown to suppress the binding affinity of the enzyme for the SPH interface . A model for inhibition is suggested in which binding of the sphingosine moiety is competitive for sPLA2 (inhibition) or for cholesterol (release of the enzyme).

Acta Microbiol Pol, 1998, 47(2), 167 - 75
Characteristics of Staphylococcus aureus isolates from atopic dermatitis with reference to proteolytic activity; Baran-Raunstrup K et al.; Staphylococcus aureus strains from atopic dermatitis (AD) patients were investigated . Diversities of biological properties, strain relationships and/or group tendencies between strains were analysed . Fifty four S . aureus strains were divided into seven biotypes using a standard biochemical API Staph system . The largest population (twenty two isolates, 40.7%) belonged to biotype A No . 6716153 . Using a standard phage set S . aureus isolates were typed into three groups: I, II and III . However, twenty seven (50.0%) isolates belonged to group No . III . Production of proteolytic enzymes was expressed by all isolates, and 87.0% showed high or moderate proteolytic activity . Also alpha or beta haemolysins production by 83.0% of the strains was demonstrated . Antimicrobial susceptibility for each strain was analysed using fifteen antibiotics . Most isolates were sensitive to chloramphenicol (98.0%), neomycin (98.0%) and fucidin (88.0%) and were resistant to ampicillin, oxacillin and rondomycin (< 20.0%) . No isolate was sensitive to all antibiotics of our study . Obvious correlations were not observed between biochemical types, phage types, haeomolysin production and antibiotic resistance pattern but proteolytic activity was demonstrated by most strains in each test.

Biochemistry, 1998 Dec 1, 37(48), 17054 - 67
Structural and dynamical characterization of a biologically active unfolded fibronectin-binding protein from Staphylococcus aureus; Penkett CJ et al.; A 130-residue fragment (D1-D4) taken from a fibronectin-binding protein of Staphylococcus aureus, which contains four fibronectin-binding repeats and is unfolded but biologically active at neutral pH, has been studied extensively by NMR spectroscopy . Using heteronuclear multidimensional techniques, the conformational properties of D1-D4 have been defined at both a global and a local level . Diffusion studies give an average effective radius of 26.2 +/- 0.1 A, approximately 75% larger than that expected for a globular protein of this size . Analysis of chemical shift, 3JHNalpha coupling constant, and NOE data show that the experimental parameters agree well overall with values measured in short model peptides and with predictions from a statistical model for a random coil . Sequences where specific features give deviations from these predictions for a random coil have however been identified . These arise from clustering of hydrophobic side chains and electrostatic interactions between charged groups . 15N relaxation studies demonstrate that local fluctuations of the chain are the dominant motional process that gives rise to relaxation of the 15N nuclei, with a persistence length of approximately 7-10 residues for the segmental motion . The consequences of the structural and dynamical properties of this unfolded protein for its biological role of binding to fibronectin have been considered . It is found that the regions of the sequence involved in binding have a high propensity for populating extended conformations, a feature that would allow a number of both charged and hydrophobic groups to be presented to fibronectin for highly specific binding.

Jpn J Antibiot, 1998 Aug, 51(8), 521 - 30
{A novel method of detecting Staphylococcus aureus heterogeneously resistant to vancomycin (hetero-VRSA)}; Hanaki H et al.; We have developed a new method of detecting clinical S . aureus strains possessing heterogeneous resistance to vancomycin (hetero-VRSA) . The method exploits characteristic antagonism between vancomycin and beta-lactam antibiotics against the strain Mu3, a representative hetero-VRSA . The method comprises of the following procedures: 1) overnight culture of bacteria is streaked on brain heart infusion agar containing 4 micrograms/ml of vancomycin, 2) paper discs impregnated with any one of beta-lactam antibiotics are placed onto the plate, and 3) the plate is incubated at 37 degrees C and the cell growth was observed after 24 h and 48 h of incubation . The Mu3 cells were grown only around the beta-lactam discs due to the antagonism between vancomycin and beta-lactam against Mu3 cells . A total of 321 MRSA clinical strains isolated in 1995 and 1996 from 12 medical facilities in Japan were tested with this method . A total of 39 strains (12.1%; 24 h) and 67 strains (20.96%; 48 h) grew around the beta-lactam discs . All the 10 strains (representing 10 facilities), tested with the analysis of resistant subpopulations to vancomycin, showed similar heterogeneous patterns as observed with Mu3 . The method was considered as a convenient and rapid substitute for the population analysis, the authentic method for the detection of hetero-VRSA strains.

Appl Environ Microbiol, 1998 Dec, 64(12), 4803 - 8
Two-component anti-Staphylococcus aureus lantibiotic activity produced by Staphylococcus aureus C55; Navaratna MA et al.; Staphylococcus aureus C55 was shown to produce bacteriocin activity comprising three distinct peptide components, termed staphylococcins C55alpha, C55beta, and C55gamma . The three peptides were purified to homogeneity by a simple four-step purification procedure that consisted of ammonium sulfate precipitation followed by XAD-2 and reversed-phase (C8 and C18) chromatography . The yield following C8 chromatography was about 86%, with a more-than-300-fold increase in specific activity . When combined in approximately equimolar amounts, staphylococcins C55alpha and C55beta acted synergistically to kill S . aureus or Micrococcus luteus but not S . epidermidis strains . The N-terminal amino acid sequences of all three peptides were obtained and staphylococcins C55alpha and C55beta were shown to be lanthionine-containing (lantibiotic) molecules with molecular weights of 3,339 and 2,993, respectively . The C55gamma peptide did not appear to be a lantibiotic, nor did it augment the inhibitory activities of staphylococcin C55alpha and/or C55beta . Plasmids of 2 . 5 and 32.0 kb are present in strain C55, and following growth of this strain at elevated temperature (42 degreesC), a large proportion of the progeny failed to produce strong bacteriocin activity and also lost the 32.0-kb plasmid . Protoplast transformation of these bacteria with purified 32-kb plasmid DNA regenerates the ability to produce the strong bacteriocin activity.

Antimicrob Agents Chemother, 1998 Dec, 42(12), 3325 - 7
Comparative efficacy of trovafloxacin in experimental endocarditis caused by ciprofloxacin-sensitive, methicillin-resistant Staphylococcus aureus; Kim YS et al.; The new fluoroquinolone trovafloxacin was tested against a ciprofloxacin-sensitive, methicillin-resistant Staphylococcus aureus strain in the rabbit model of endocarditis . Trovafloxacin was more effective than vancomycin (CFU/g of vegetation, 2.65 +/- 1.87 versus 4.54 +/- 2.80 {mean +/- standard deviation}; P < 0.05) or ampicillin-sulbactam plus rifampin (4.9 +/- 1.1 CFU/g) . The addition of ampicillin-sulbactam to trovafloxacin tended to reduce titers further.

Antimicrob Agents Chemother, 1998 Dec, 42(12), 3317 - 9
Examination of methicillin-resistant and methicillin-susceptible Staphylococcus aureus mutants with low-level fluoroquinolone resistance; Sulavik MC et al.; For Staphylococcus aureus, stepwise mutations result in high-level quinolone resistance . Methicillin-resistant and -susceptible quinolone-resistant, first-step mutants generated in vitro were obtained and found to be no different than those recovered from murine abscesses . Approximately 10% of all first-step mutants were resistant to ethidium bromide, and selected strains had mutations that mapped to flqB . NorA-mediated resistance among first-step mutants may be more prevalent than previously reported.

Antimicrob Agents Chemother, 1998 Dec, 42(12), 3073 - 8
Antibiotic-induced release of lipoteichoic acid and peptidoglycan from Staphylococcus aureus: quantitative measurements and biological reactivities; van Langevelde P et al.; Antibiotics with different mechanisms of action may vary with respect to their effects on the release and immunostimulatory activities of cell wall fragments from gram-positive bacteria . Therefore, after Staphylococcus aureus was cultured for 4 h in the absence of antibiotics (control) and in the presence of beta-lactam antibiotics (imipenem, flucloxacillin, or cefamandole) and protein synthesis-inhibiting antibiotics (erythromycin, clindamycin, or gentamicin), the lipoteichoic acid (LTA) and peptidoglycan (PG) levels in the bacterial supernatants were measured . beta-Lactam antibiotics greatly enhanced the release of LTA and PG (4- to 9-fold and 60- to 85-fold, respectively), whereas protein synthesis inhibitors did not affect PG release and even inhibited the release of LTA compared to the amount of LTA released in control cultures . The capacity of beta-lactam supernatants to stimulate the production of tumor necrosis factor alpha and interleukin-10 in human whole blood was significantly higher than that of protein synthesis inhibitor or control supernatants; the amounts of these cytokines released were directly proportional to the concentrations of PG and LTA in the supernatants . Enzymatic degradation of PG in the supernatants indicated that PG was mainly responsible for the observed biological reactivity.

Acad Emerg Med, 1998 Nov, 5(11), 1076 - 80
Wound irrigation with tap water; Moscati RM et al.; OBJECTIVE: The study hypothesis was that irrigation with tap water is as efficacious as irrigation with sterile saline in removing bacteria from simple lacerations in preparation for wound closure . METHODS: The study was conducted in a laboratory rat model previously described in the literature for evaluating wound irrigation techniques . The study used a randomized, blinded crossover design using 10 animals . Two full-thickness skin lacerations were made on each animal and each wound was inoculated with standardized concentrations of a Staphylococcus aureus broth . Wounds were irrigated for 4 minutes with normal saline from a syringe or 4 minutes with tap water from a faucet . Tissue specimens were sampled from each laceration prior to and following irrigation . Bacterial counts per gram of tissue were determined for each specimen and compared pre- and postirrigation . RESULTS: Preirrigation bacterial counts were not significantly different for saline vs tap water specimens . The wounds irrigated with saline had a mean reduction in bacterial count of 54.7% (SD=+/-28%), while the wounds irrigated with tap water had a mean reduction in bacterial count of 80.6% (SD=+/-20%) (p < 0.05, 2-tailed, paired t-test) . CONCLUSIONS: In this animal model, bacterial decontamination of simple lacerations was not compromised, and was actually improved using tap water irrigation . This is most likely due to the mechanical differences in the types of irrigation . In certain instances, such as with upper-extremity lacerations, tap water irrigation would likely be cheaper and less labor-intensive than irrigation with normal saline from a syringe.

FEMS Microbiol Lett, 1998 Nov 15, 168(2), 227 - 33
The enterotoxin D plasmid of Staphylococcus aureus encodes a second enterotoxin determinant (sej); Zhang S et al.; Staphylococcus aureus enterotoxin D is one of the serotypes most commonly associated with food poisoning . Further characterization of the enterotoxin D-encoding plasmid revealed the presence of an open reading frame which encodes a previously unidentified enterotoxin, designated staphylococcal enterotoxin J (SEJ) . SEJ is a protein of 269 amino acid residues which has substantial sequence similarity to the staphylococcal A, E, D family of enterotoxins . The enterotoxin D and J open reading frames are transcribed in opposite directions and are separated by an 895 nucleotide intergenic region which contains a perfect inverted repeat, with each arm of the repeat having a length of 21 nucleotides . Chloramphenicol acetyl transferase (cat) transcriptional fusions were used to quantify expression from the enterotoxin gene promoters . Both enterotoxin genes are expressed in S . aureus . However, only sed is regulated by the agr virulence gene signal transduction pathway . Western blot analyses utilizing anti-enterotoxin antisera have confirmed the results obtained with the cat reporter system . PCR amplification studies suggest that the sej determinant may be present on all sed-encoding plasmids.

Blood, 1998 Dec 1, 92(11), 4366 - 74
In vivo treatment with granulocyte colony-stimulating factor results in divergent effects on neutrophil functions measured in vitro; Leavey PJ et al.; We have studied the effects of granulocyte colony-stimulating factor (G-CSF) administration to normal individuals on a variety of functional and biochemical neutrophil characteristics that relate to host defense . G-CSF adversely affected neutrophil (polymorphonuclear leukocyte {PMN}) chemotaxis . While this could be partially explained by reduced assembly of neutrophil F-actin, we also recognized an elevated cytosolic calcium mobilization and a normal upregulation of neutrophil CD11b . G-CSF resulted in reduced PMN killing of Staphylococcus aureus with a 10:1 (bacteria:neutrophil) ratio and normal killing with a 1:1 ratio . In association with this, we demonstrated divergent effects on the respiratory burst of intact cells and divergent effects on the content of marker proteins for neutrophil granules . While G-CSF may have resulted in increased content of cytochrome b558 in the cell membrane, it did not alter the amounts of cytosolic oxidase components . After therapy, there was normal content of the azurophilic granule marker, myeloperoxidase, decreased content of the specific granule marker, lactoferrin, and normal content of lysozyme (found in both granules classes) . Finally, G-CSF therapy markedly reduced the apoptotic rate of the isolated neutrophil . Therefore, considering disparate functional and biochemical activities, the real benefit of G-CSF therapy may lie in enhanced number and survival of neutrophils.

Acta Derm Venereol, 1998 Nov, 78(6), 424 - 7
Expression of T cell receptor V beta chain in lesional skin of atopic dermatitis; Ha SJ et al.; Atopic dermatitis is a chronic, relapsing inflammatory skin disorder characterized by local infiltration of T cells . To date, numerous reports have shown that Staphylococcus aureus may exacerbate atopic dermatitis, and superantigens produced by this organism are thought to be one of the major causative factors in atopic dermatitis . The purpose of this study was to evaluate the role of staphylococcal superantigen in atopic dermatitis by observing expression of the variable region of beta chain of T cell receptor (TCR V beta) in the inflammatory cells infiltrating cutaneous lesions of atopic dermatitis . Fourteen patients with atopic dermatitis were enrolled . Punch biopsy specimens were obtained from lesional and normal-appearing skin of all patients . The expression of TCR V beta was studied by means of immunohistochemical technique using monoclonal antibodies . In 4 out of 14 patients, the tendencies of preferential expression of specific TCR V beta were found in lesional skin . This study suggested that staphylococcal superantigen and its corresponding T cell subsets may act as causative or pathogenic factors in a subgroup of atopic dermatitis.

Eur J Clin Microbiol Infect Dis, 1998 Sep, 17(9), 622 - 8
Clinical and epidemiological findings in mechanically-ventilated patients with methicillin-resistant Staphylococcus aureus pneumonia; Pujol M et al.; Over the 5-year period from 1990 to 1994, a prospective cohort study was conducted to define the clinical and epidemiological characteristics of ventilator-associated methicillin-resistant Staphylococcus aureus (MRSA) pneumonia acquired during a large-scale outbreak of MRSA infection . Of 2411 mechanically ventilated patients, 347 (14.4%) acquired MRSA, 220 (63.4%) had MRSA positive respiratory tract samples and 41 (18.6%) developed ventilator-associated MRSA pneumonia . The overall attack rate for ventilator-associated MRSA pneumonia was 1.56 episodes/1000 ventilator days, but annual attack rates varied according to the trend of the outbreak (range 4.9-0.2) . In comparison with methicillin-sensitive Staphylococcus aureus (MSSA), which was implicated in 98 episodes of ventilator-associated pneumonia, MRSA caused exclusively late-onset ventilator-associated pneumonia, while MSSA caused both early-onset {55 of 98 (56.1%) episodes} and late-onset {43 of 98 (43.8%) episodes} ventilator-associated pneumonia . Logistic regression analysis of all patients with Staphylococcus aureus pneumonia revealed intubation for more than 3 days (odds ratio (OR),1.11; confidence interval (CI):1.03-1.18) and prior bronchoscopy (OR,5.8; CI,1.85-18.19) to be independent variables associated with MRSA pneumonia . The results indicate that MRSA ventilator-associated pneumonia is a frequent complication in intensive care patients, manifesting itself as late-onset pneumonia in patients who have been intubated for prolonged periods and/or have often undergoing previous bronchoscopy.

Infect Control Hosp Epidemiol, 1998 Nov, 19(11), 872 - 6
Prevalence of nosocomial infections in general hospitals in Belo Horizonte; Rezende EM et al.; OBJECTIVE: To assess the magnitude of nosocomial infections (NI) in general hospitals of Belo Horizonte . DESIGN: Multicenter point-prevalence study of nosocomial infections . SETTING: All of the 11 general hospitals of Belo Horizonte that have more than 20 beds, from August 27 to October 5, 1992 . RESULTS: Of the 2,339 patients surveyed, 267 patients had 328 nosocomial infections . The global prevalence rate of NI was 14.0%, ranging from 4.6% to 27.3% in the hospitals surveyed . The most prevalent infections were found to be pneumonia and surgical-wound infections, representing 19.5% and 19.2%, respectively, of the total infections . The highest prevalence rates of NI were observed in the cardiac surgery (31.9%), pediatric (27.2%), and orthopedic (20.7%) services . The most frequently isolated microorganisms were Staphylococcus aureus, Escherichia coli, Pseudomonas species, and Klebsiella species . CONCLUSION: The study allowed a thorough evaluation of the NI distribution profile in Belo Horizonte, Minas Gerais, Brazil, and showed it to be a serious public health problem that requires interinstitutional efforts so that effective action can be taken.

Int J Infect Dis, 1998 Jul-Sep, 3(1), 26 - 31
Extensive intra-hospital spread of a methicillin-resistant staphylococcal clone; Sanches IS et al.; OBJECTIVE: Infection by antibiotic-resistant bacteria can pose serious complications to the therapy of cancer patients . The authors introduced DNA fingerprinting techniques for tracking methicillin-resistant Staphylococcus aureus (MRSA) clones recovered at a central cancer hospital of Lisbon (Instituto Portugues de Oncologia) with the purpose of making an inventory of the MRSA clones endemic during 1995, and compared them with the outbreak-related clones of 1993 . DESIGN: A small group (6 strains) of epidemiologically related MRSA isolated during a suspected outbreak in 1993 and all consecutive single-patient isolates of MRSA (34 strains) recovered between January and November of 1995 from infected patients and health care personnel were characterized using DNA probes and pulsed-field gel electrophoresis . RESULTS: The six 1993 strains and more than half of all 1995 isolates, including those recovered from the health care personnel, showed DNA fingerprints characteristic of the "Iberian MRSA," a multiresistant clone widespread in Portuguese and Spanish hospitals . Four patients were infected by another MRSA clone previously seen only in hospitals in Brazil . CONCLUSION: The epidemic Iberian clone was among the index cases involved with the MRSA outbreak in 1993, and this was found to be endemic in a follow-up survey conducted in 1995, colonizing health care personnel and spreading to most hospital wards . A few isolates of another epidemic clone, the Brazilian MRSA, also were detected among 1995 isolates . A better understanding of the mechanism(s) of epidemicity of these rapidly spreading clones is urgently needed.

J Hosp Infect, 1998 Nov, 40(3), 225 - 35
A control programme for MRSA (methicillin-resistant Staphylococcus aureus) containment in a paediatric intensive care unit: evaluation and impact on infections caused by other micro-organisms; Cosseron-Zerbib M et al.; Methicillin-resistant Staphylococcus aureus (MRSA) is increasingly reported as a hospital-acquired pathogen in intensive care units (ICUs) . The inconsistent application of hygiene measures by healthcare workers accounts largely for the epidemic dissemination of such resistant strains . The efficacy of a control programme to prevent spread of MRSA was assessed in our paediatric ICU (PICU) from April 1992 to December 1995 . Patients initially had weekly MRSA cultures taken from samples of anterior nares and perineum, but from January 1994, cultures were also obtained upon admission . Immediately after notification, all MRSA carriers were isolated . Education of hospital staff was an essential component of our programme . Nosocomial infection rates were recorded retrospectively in 1992 and 1993, and prospectively in 1994 and 1995 . Incidence rates between 'pre-programme' and 'programme' periods were compared . The rate of MRSA infection decreased from 5.9-0.8/1000 Patient-Days (PD), (P < 10(-7) . MRSA carriage also decreased from 34-2% (P < 10(-9) and the ratio of MRSA to all S . aureus fell from 71-11% (P < 10(-4) . The decrease in the global incidence of infection from 20.1-13.9/1000 PD (P = 0.002) was due only to the decrease in MRSA infection . However, between 1994 and 1995, there was a significant increase in the number of transplant patients despite a constant patient/nurse ratio . The nosocomial infection rates caused by other micro-organisms decreased among the transplant patients from 64.8-33.2/1000 transplanted PD (P = 0.009) between 1994 and 1995 . At the same time, we observed a slight increase of infections in non-transplanted patients, which may have been due to the effect of increased overall workload on those patients who were supposed to have fewer nosocomial risk factors . We conclude that implementation of infection control measures directed towards limiting person-to-person spread was effective in controlling high MRSA infection rates in a PICU, but it is important to allow enough time for staff to carry out hygiene practices thoroughly.

J Hosp Infect, 1998 Nov, 40(3), 203 - 9
Methicillin-resistant Staphylococcus aureus: impact at a national cystic fibrosis centre; Thomas SR et al.; In many patient populations there has been a progressive increase in the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) . We examined the prevalence and consequences of acquiring MRSA in the adult cystic fibrosis (CF) population at Royal Brompton . Patients who became colonized by MRSA between 1965 and 1997 were identified from an existing database and case-notes were reviewed . Clinical and microbiological data were recorded . Twenty-six patients became colonized with MRSA during this period . Median age at acquisition was 23.4 years (range 11.8-43.3 years) and median FEV1 (percent predicted) was 28.9% (range 12-81%) . Twenty patients (77%) had an FEV1 of < or = 40% predicted MRSA was probably acquired by four patients at Royal Brompton . In 17 patients isolates wer first identified whilst under the care of a total of 11 other institutions . Since the first case of MRSA infection in 1982, there has been an increase in prevalence to a current rate of nine cases in the first seven months of 1997 . The commonest site of colonization was the lower airway (96%); the nose (23%) and skin sites (15%) were more rarely affected . Duration of colonization was frequently brief with nine cases (35%) lasting less than one month . The identification of MRSA appeared to be of little clinical significance, and did not generally affect outcomes . Only three patients were MRSA positive at the time of death, and in only one of these was MRSA considered a possible contributing factor.

J Hosp Infect, 1998 Nov, 40(3), 179 - 91
MRSA in cystic fibrosis . London, 16 June 1997; Staphylococcal strains involved in bovine mastitis are inhibited by Staphylococcus aureus antimicrobial peptides; Departamento de Microbiologia Geral, Universidade Federal do Rio de Janeiro, BrazilThe inhibitory activity of five bacteriocin (Bac)-producer strains of Staphylococcus aureus was tested against bacteria pathogenic for cattle . Sixty-five epidemiologically unrelated strains of Staph . aureus involved in bovine mastitis were used as indicators in an agar diffusion test . Bacteriocins produced by four strains could inhibit only a limited number of test organisms . However, all 65 indicator strains proved to be susceptible to the combined action of both bacteriocins encoded by pRJ9, a Bac plasmid found in strain A53 . Therefore, the bacteriocins produced by this strain may represent new antimicrobial peptides with potential applications in the prevention and treatment of bovine mastitis.

J Biol Chem, 1998 Dec 4, 273(49), 32614 - 7
Pb(II)-translocating P-type ATPases; Rensing C et al.; The cad operon of Staphylococcus aureus plasmid pI258, which confers cadmium resistance, encodes a transcriptional regulator, CadC, and CadA, an ATP-coupled Cd(II) pump that is a member of the superfamily of cation-translocating P-type ATPases . The Escherichia coli homologue of CadA, termed ZntA, is a Zn(II)/Cd(II) pump . The results described in this paper support the hypothesis that ZntA and CadA are Pb(II) pumps . First, CadC is a metal-responsive repressor that responds to soft metals in the order Pb>Cd>Zn . Second, both CadA and ZntA confer resistance to Pb(II) . Third, transport of 65Zn(II) in everted membrane vesicles of E . coli catalyzed by either of these two P-type ATPase superfamily members is inhibited by Pb(II).

J Bacteriol, 1998 Dec, 180(23), 6232 - 41
Role of SarA in virulence determinant production and environmental signal transduction in Staphylococcus aureus; Chan PF et al.; The staphylococcal accessory regulator (encoded by sarA) is an important global regulator of virulence factor biosynthesis in Staphylococcus aureus . To further characterize its role in virulence determinant production, an sarA knockout mutant was created by insertion of a kanamycin antibiotic resistance cassette into the sarA gene . N-terminal sequencing of exoproteins down-regulated by sarA identified several putative proteases, including a V8 serine protease and a novel metalloprotease, as the major extracellular proteins repressed by sarA . In kinetic studies, the sarA mutation delays the onset of alpha-hemolysin (encoded by hla) expression and reduces levels of hla to approximately 40% of the parent strain level . Furthermore, SarA plays a role in signal transduction in response to microaerobic growth since levels of hla were much lower in a microaerobic environment than after aerobic growth in the sarA mutant . An exoprotein exhibiting hemolysin activity on sheep blood, and up-regulated by sarA independently of the accessory gene regulator (encoded by agr), was specifically induced microaerobically . Transcriptional gene fusion and Western analysis revealed that sarA up-regulates both toxic shock syndrome toxin 1 gene (tst) expression and staphylococcal enterotoxin B production, respectively . This study demonstrates the role of sarA as a signal transduction regulatory component in response to aeration stimuli and suggests that sarA functions as a major repressor of protease activity . The possible role of proteases as regulators of virulence determinant stability is discussed.

J Bacteriol, 1998 Dec, 180(23), 6082 - 9
The Staphylococcus aureus alternative sigma factor sigmaB controls the environmental stress response but not starvation survival or pathogenicity in a mouse abscess model; Chan PF et al.; The role of sigmaB, an alternative sigma factor of Staphylococcus aureus, has been characterized in response to environmental stress, starvation-survival and recovery, and pathogenicity . sigmaB was mainly expressed during the stationary phase of growth and was repressed by 1 M sodium chloride . A sigB insertionally inactivated mutant was created . In stress resistance studies, sigmaB was shown to be involved in recovery from heat shock at 54 degreesC and in acid and hydrogen peroxide resistance but not in resistance to ethanol or osmotic shock . Interestingly, S . aureus acquired increased acid resistance when preincubated at a sublethal pH 4 prior to exposure to a lethal pH 2 . This acid-adaptive response resulting in tolerance was mediated via sigB . However, sigmaB was not vital for the starvation-survival or recovery mechanisms . sigmaB does not have a major role in the expression of the global regulator of virulence determinant biosynthesis, staphylococcal accessory regulator (sarA), the production of a number of representative virulence factors, and pathogenicity in a mouse subcutaneous abscess model . However, SarA upregulates sigB expression in a growth-phase-dependent manner . Thus, sigmaB expression is linked to the processes controlling virulence determinant production . The role of sigmaB as a major regulator of the stress response, but not of starvation-survival, is discussed.

J Food Prot, 1998 Nov, 61(11), 1459 - 64
Plasmid-mediated resistance to antimicrobial agents among listeriae; Lemaitre JP et al.; The resistance to 14 antiseptic-disinfectant and dye compounds of 208 strains of Listeria (132 L . monocytogenes, 63 L . innocua, 8 L . seeligeri, 1 L . ivanovii, 1 L . welshimeri, and 3 Listeria spp.) was tested by the agar-dilution procedure . The Listeria strains were isolated from different varieties of foods, environments of cheese dairies, humans, and wild birds . A total of 14 (6.7%) Listeria strains (12 L . monocytogenes and 2 L . innocua) were resistant to benzalkonium chloride, hexamidine diisethionate, and ethidium bromide . This multiple resistance was observed more frequently from strains of Listeria spp . detected on carcasses of poultry (47%) than strains isolated from human listeriosis cases or carriers (11.5%), red meats (10%), cheeses (5.4%), wild birds (0.9%), and environments of cheese dairies (0%) . Among resistant strains, 10 groups of strains (71.5%) were differentiated by serogroup, phage typing, and sensitivity or resistance to cadmium . Extrachromosomal DNA was found in all resistant strains and was transferred at a high frequency among Listeria spp . (8.7 x 10(-6) to 1 x 10(-3) transconjugant CFUs per one donor CFU) . These resistances were also transferable between L . monocytogenes and Staphylococcus aureus with similar transfer frequencies (7.8 x 10(-6) to 1 x 10(-4) and between strains of Staphylococcus aureus with similar transfer frequencies from 8 x 10(-7) to 3.3 x 10(-6) . These results suggest that emergence of this multiple resistance in Listeria spp . could be due to acquisition of a replicon originating in staphylocci.

J Clin Pathol, 1998 Aug, 51(8), 633 - 4
Unusual aetiology of persistent back pain in a patient with multiple myeloma: infectious discitis; Burton CH et al.; A 47 year old man with multiple myeloma presented with persistent back pain caused by infectious discitis . Aspiration of the affected vertebral disc space was carried out, guided by computed tomography, and microbiological examination of the aspirate revealed Staphylococcus aureus and Mycobacterium tuberculosis . Antituberculous and antistaphylococcal antibiotic treatment resulted in a dramatic clinical response with complete resolution of the vertebral abscess . Detailed radiological and microbiological investigations are necessary to diagnose unusual causes of chronic bone pain such as discitis or infectious bone disease in patients with multiple myeloma.

Infect Immun, 1998 Dec, 66(12), 5988 - 93
Selective activation of sar promoters with the use of green fluorescent protein transcriptional fusions as the detection system in the rabbit endocarditis model; Cheung AL et al.; The global regulatory locus sar is composed of three overlapping transcripts initiated from a triple-promoter system (designated P1, P3, and P2) . To explore if the individual sar promoters are differentially expressed in vitro and in vivo, we constructed a shuttle plasmid (pALC1434) containing a promoterless gfpUV gene (a gfp derivative {Clontech}) preceded by a polylinker region . Recombinant shuttle vectors containing individual sar promoters upstream of the gfpUV reporter gene were then introduced into Staphylococcus aureus RN6390 . Northern and immunoblot analysis revealed that P1 is stronger than the P2 and P3 promoters in vitro . Additionally, the levels of the gfpUV transcript driven by individual sar promoters also correlated with the growth cycle dependency of these promoters in liquid cultures, thus suggesting the utility of pALC1434 as a vehicle for reporter fusion . Using the rabbit endocarditis model, we examined the expression of these three GFPUV fusions in vivo by fluorescence microscopy of infected cardiac vegetations 24 h after initial intravenous challenge . Similar to the in vitro findings, P1 was activated both in the center and on the surface of the vegetations . In contrast, the P3 promoter was silent both in vivo and in vitro as determined by fluorescence microscopy . Remarkably, P2 was silent in vitro but became highly activated in vivo . In particular, the sar P2 promoter was activated on the surface of the vegetation but not in the center of the lesion . These data imply that in vivo promoter activation of sar differed from that observed in vitro . Moreover, the individual sar promoters may be differentially expressed in different areas within the same anatomic niche, presumably reflecting the microbial physiological response to distinct host microenvironments . As the sar locus controls the synthesis of both extracellular and cell wall virulence determinants, these promoter-gfpUV constructs should be useful to characterize many aspects of S . aureus gene regulation in vivo.

Eur J Biochem, 1998 Oct 15, 257(2), 389 - 94
The lactose transporter of Staphylococcus aureus--overexpression, purification and characterization of the histidine-tagged domains IIC and IIB; Kowolik CM et al.; The lactose-specific enzyme II (IICBlac) of the phosphoenolpyruvate-dependent phosphotransferase system (PTS) of Staphylococcus aureus couples translocation to phosphorylation of the transported lactose . It is composed of the N-terminal membrane-bound IIC domain, which includes the sugar-binding site, and the C-terminal IIB domain, which contains the phosphorylation site at Cys476 . IIC (residues 1-461) fused with a C-terminal affinity tag of six histidine residues and IIB (residues 461-570) fused with an N-terminal histidine tag were overexpressed in Escherichia coli and purified by Ni2+ chelate affinity chromatography . 2 mg of IIClac-His6 obtained from 10 g of cells and 12 mg of His6-IIBlac obtained from 8 g of wet cells were purified to homogeneity . 56% of the total IIClac-His6 activity present in the membranes could be recovered . Purification by affinity chromatography yields the opportunity to exchange the detergent . The Km determined in an activity assay for IIClac-His6 in the presence of the histidine-tagged IIBlac domain (His6-IIBlac) was similar to the Km determined for histidine-tagged IICBlac-His {Peters, D . & Hengstenberg, W . (1995) Eur . J . Biochem . 228, 798-804}, suggesting that substrate affinity is barely influenced by the expression of the domains as separate proteins . The Vmax is reduced by a factor of 25 compared with IICBlac-His . His6-IIBlac also complements the activity of the IICBlac mutant C476S, which possesses an inactive IIB domain . This result indicates that IIC and IIB are flexibly linked in such a way that free His6-IIBlac can displace the inactive IIB domain fron its contact site on the IIC domain . His6-IIBlac is shorter and more stable than a previously constructed IIB domain (IIBlac-His) {Peters, D . & Hengstenberg, W . (1995) Eur . J . Biochem . 228, 798-804)}, which contained a C-terminal histidine tag . The Km values for phosphoenolpyruvate-dependent phosphorylation of His6-IIBlac and IIBlac-His are nearly indistinguishable, suggesting that the location of the affinity tag either at the N-terminal or at the C-terminal end of the domain does not influence the substrate affinity.

Br J Rheumatol, 1998 Oct, 37(10), 1095 - 101
Surface-associated protein from Staphylococcus aureus stimulates osteoclastogenesis: possible role in S . aureus-induced bone pathology; Meghji S et al.; OBJECTIVE: Staphylococcus aureus is the cause of bone destruction in osteomyelitis, bacterial arthritis and orthopaedic implant failure . We have previously shown that gentle saline extraction of S . aureus has revealed the presence of an extremely potent stimulator of osteoclast activation in both the murine calvarial bone resorption assay and the isolated chick osteoclast resorption assay . In order to investigate the mechanism of action of this surface-associated material (SAM), we have investigated its capacity to recruit osteoclasts . METHODS: The murine bone marrow osteoclast recruitment assay was used . The ability of the recruited cells to resorb dentine slices was also investigated . Results . The SAM from S . aureus dose dependently stimulated tartrate-resistant acid phosphatase (TRAP)-positive osteoclast formation and pit formation on dentine slices . Neutralization of the cytokines tumour necrosis factor alpha and interleukin (IL)-6 totally inhibited, but antagonism of IL-1 only partially blocked, the stimulated maturation of osteoclast-like cells . CONCLUSION: These findings suggest that bone destruction associated with local infection by S . aureus is due to the stimulation of osteoclast formation induced by the action of the easily solubilized SAM, and could explain the large numbers of osteoclasts found in infarcted bone in osteomyelitis.

Clin Exp Allergy, 1998 Oct, 28(10), 1264 - 72
Circulating CLA+ lymphocytes from children with atopic dermatitis contain an increased percentage of cells bearing staphylococcal-related T-cell receptor variable segments; Torres MJ et al.; BACKGROUND: Atopic dermatitis is an allergic T-cell mediated skin inflammation . Staphylococcus aureus colonization is very common in cutaneous atopic dermatitis lesions . The cutaneous lymphocyte-associated antigen (CLA) is a T cell skin homing receptor that defines T lymphocytes associated with the cutaneous immune response . OBJECTIVE: To study whether CLA+ T cells from atopic dermatitis children present a selective expression for Staphylococcus aureus-related TCR Vbeta segments . METHODS: Peripheral blood T cells were stained with HECA-452 (anti-CLA) and a panel of TCR Vbeta specific monoclonal antibodies and analysed by flow cytometry . RESULTS: Atopic dermatitis patients have a higher percentage of circulating CLA+ CD3+ lymphocytes compared with healthy controls . Patients with active atopic dermatitis during the study expressed a higher percentage of cells positive for the TCR Vbeta2 and Vbeta5.1 segments in the CLA+ but not in the CLA- subset . These TCR Vbetas are recognized by staphylococcal superantigens . Moreover, there was an increased percentage of HLA-DR+ expression by CLA+ Vbeta5.1+ T cells in patients with active atopic dermatitis, but those patients whose eczema was inactive had very similar values to healthy controls regarding TCR Vbeta and HLA-DR phenotype in circulating CLA+ T lymphocytes . CONCLUSION: Our data indicate that circulating skin-homing T cells of patients with active atopic dermatitis contain an increased percentage of cells bearing TCR Vbeta segments related with Staphylococcus aureus . Staphylococcus superantigens may therefore trigger expansion or at least circulation of appropriate CLA+ T cells.

J Biol Chem, 1998 Nov 27, 273(48), 31702 - 6
Effects of substrate and inhibitor binding on proteolysis of isoleucyl-tRNA synthetase from Staphylococcus aureus; Pope AJ et al.; Binding of ligands to isoleucyl-tRNA synthetase (IleRS; E) from Staphylococcus aureus was investigated through effects on proteolytic digestion . Approximately 50-fold higher concentrations of protease (trypsin or chymotrypsin) were required to inactivate IleRS after incubation with substrates and formation of the E . Ile-AMP intermediate compared with free E . Binding of pseudomonic acid A (PS-A) or isoleucynol adenylate (Ile-ol-AMP) also induced resistance to proteolysis and altered the patterns of IleRS cleavage fragments in an inhibitor-class specific manner . The determinants for PS-A binding were investigated via proteolysis of E.{3H}PS-A . Limited proteolysis of E.{3H}PS-A (excising residues 186-407) could be achieved without significant loss of bound inhibitor, eliminating this region as contributing to inhibitor binding . Assays were developed which allowed IleRS proteolysis to be readily followed using fluorescence polarization . Inhibitor-protected IleRS was labeled with fluorescein isothiocyanate with only a small effect upon catalytic activity (Fl-IleRS) . The (pseudo) kinetics of proteolytic cleavage of Fl-IleRS could be measured at low nanomolar Fl-IleRS concentrations in 96/384-well microtiter plates, allowing real-time monitoring of dose-dependent protection from proteolysis . Thus, inhibitor (and substrate) binding could be reproducibly assessed in the absence of measurements of catalytic acitvity . This could potentially form the basis of novel screening assays for ligands to other proteins.

J Biol Chem, 1998 Nov 27, 273(48), 31691 - 701
Characterization of isoleucyl-tRNA synthetase from Staphylococcus aureus . II . Mechanism of inhibition by reaction intermediate and pseudomonic acid analogues studied using transient and steady-state kinetics; Pope AJ et al.; The interactions of isoleucyl-tRNA synthetase (IleRS, E) from Staphylococcus aureus with both intermediate analogues and pseudomonic acid (PS-A) have been investigated using transient and steady-state techniques . Non-hydrolyzable analogues of isoleucyl-AMP (I) were simple competitive inhibitors (Ile-ol-AMP, Ki = 50 nM and Ile-NHSO2-AMP, Ki = 1 nM;) . PS-A (J) inhibits IleRS via a slow-tight binding competitive mechanism where E.J (Kj = approximately 2 nM), undergoes an isomerization to form a stabilized E*.J complex (K*j = 50 pM) . To overcome tight-binding artifacts when K*j << {E}, K*j values were estimated from PPi/ATP exchange where {S} >> Km, thus raising K*j,app well above {E} . Using {3H}PS-A, it was confirmed that binding occurs with 1:1 stoichiometry and is reversible . Formation of inhibitor complexes was monitored directly through changes in enzyme tryptophan fluorescence . For Ile-ol-AMP and Ile-NHSO2-AMP, the fluorescence intensity of E.I was identical to that when E.Ile-AMP forms catalytically . Binding of PS-A induced only a small change in IleRS fluorescence that was characterized using transient kinetic competition . SB-205952, a PS-A analogue, produced a 37% quenching of IleRS fluorescence upon binding as a result of radiationless energy transfer . Inhibitor reversal rates were obtained by measuring relaxation between spectroscopically different complexes . Together, these data represent a comprehensive solution to the kinetics of inhibition by these compounds.

J Biol Chem, 1998 Nov 27, 273(48), 31680 - 90
Characterization of isoleucyl-tRNA synthetase from Staphylococcus aureus . I: Kinetic mechanism of the substrate activation reaction studied by transient and steady-state techniques; Pope AJ et al.; The kinetic mechanism for the amino acid activation reaction of Staphylococcus aureus isoleucyl-tRNA synthetase (IleRS; E) has been determined from stopped-flow measurements of the tryptophan fluorescence associated with the formation of the enzyme-bound aminoacyl adenylate (E.Ile-AMP; Scheme 1) . Isoleucine (Ile) binds to the E.ATP complex (K4 = 1.7 +/- 0.9 microM) approximately 35-fold more tightly than to E (K1 = 50-100 microM), primarily due to a reduction in the Ile dissociation rate constant (k-1 approximately 100-150 s-1, cf . k-4 = 3 +/- 1.5 s-1) . Similarly, ATP binds more tightly to E.Ile (K3 = approximately 70 microM) than to E (K2 = approximately 2.5 mM) . The formation of the E.isoleucyl adenylate intermediate, E.Ile-AMP, resulted in a further increase in fluorescence allowing the catalytic step to be monitored (k+5 = approximately 60 s-1) and the reverse rate constant (k-5 = approximately 150-200 s-1) to be determined from pyrophosphorolysis of a pre-formed E.Ile-AMP complex (K6 = approximately 0.25 mM) . Scheme 1 was able to globally predict all of the observed transient kinetic and steady-state PPi/ATP exchange properties of IleRS by simulation . A modification of Scheme 1 could also provide an adequate description of the kinetics of tRNA aminoacylation (kcat,tr = approximately 0.35 s-1) thus providing a framework for understanding the kinetic mechanism of aminoacylation in the presence of tRNA and of inhibitor binding to IleRS.

J Mass Spectrom, 1998 Oct, 33(10), 1009 - 16
Identification of the active site serine of penicillin-binding protein 2a from methicillin-resistant Staphylococcus aureus by electrospray mass spectrometry; Sun Y et al.; Penicillin-binding protein 2a (PBP2a), a high molecular mass PBP, is the primary enzyme responsible for the beta-lactam resistance in methicillin-resistant Staphylococcus aureus (MRSA) . Inhibition of a PBP such as PBP2a by beta-lactams is due to covalent modification of an active site serine residue . Based on the sequence alignment with well studied beta-lactamases, DD-carboxypeptidases and other high molecular mass PBPs, the serine of a tetrad S403XXK in PBP2a was tentatively identified as the penicillin-binding site . However, direct evidence for the involvement of serine403 has not been reported . In this study, a method which combines liquid chromatography/electrospray mass spectrometry (LC/MS) and nano-electrospray MS for the identification of the active site serine in PBP2a is described . The covalent binding of the beta-lactams was carried out in vitro with the recombinant PBP2a . Peptide mapping of the cyanogen bromide fragments from penicilloyl-PBP2a, using microbore LC/MS, provided a rapid identification of the modified peptide with a 334 Da mass increase . The acylated peptide was isolated and further digested with trypsin . Nano-electrospray MS/MS sequencing of the acylated peptide in the tryptic digest showed that the penicillin was indeed attached to serine403.

Res Commun Mol Pathol Pharmacol, 1998 Aug, 101(2), 179 - 86
Novel compounds, 1,3-selenazine derivatives, as antibacterial agents against Escherichia coli and Staphylococcus aureus; Koketsu M et al.; The antibacterial activities of several kinds of novel 4H-5,6-dihydro-1,3-selenazine derivatives against Escherichia coli and Staphylococcus aureus were investigated . 4-Hydroxy-4-methyl-2-p-tolyl-4H-5,6-dihydro-1,3-selenazine (TS-1), 4-ethyl-4-hydroxy-2-p-tolyl-4H-5,6-dihydro-1,3-selenazine (TS-2), and 4-hydroxy-4-methyl-2-pentyl-4H-5,6-dihydro-1,3-selenazine (PS-1) exhibited strong inhibitory activity against E . coli, and TS-1, TS-2, PS-1, 4-hydroxy-4-methyl-2-pentyl-6-propyl-4H-5,6-dihydro-1,3-selenazine (PS-6) and 4-hydroxy-4-methyl-2-pentyl-6-phenyl-4H-5,6-dihydro-1,3-selenazine (PS-8) also showed inhibitory activity against S . aureus . 4H-5,6-dihydro-1,3-thiazines and 1,3-selenazole had no inhibitory activities against both bacteria . TS-1, TS-2, and PS-1 exhibited marked antibacterial activities against both Gram-negative and Gram-positive bacteria.

J Immunol, 1998 Nov 15, 161(10), 5627 - 32
Staphylococcal enterotoxin A-induced injury of human lung endothelial cells and IL-8 accumulation are mediated by TNF-alpha; Fujisawa N et al.; Staphylococcal enterotoxin A (SEA), a superantigen produced by some strains of Staphylococcus aureus, causes a variety of clinical manifestations ranging from food poisoning to shock . S . aureus can also be associated with the development of acute respiratory distress syndrome, and SEA has been shown to cause an inflammatory reaction in the lung . Therefore, we examined possible interactions between SEA, PBMCs, polymorphonuclear cells (PMNs), and normal human lung microvascular endothelial cells (HMVEC-L), as well as the role of these interactions on the secretion of IL-8 . Injury to HMVEC-L, as measured by the release of 51Cr, increased significantly when HMVEC-L were incubated with SEA and PBMCs . IL-8 was secreted by both PBMCs and HMVEC-L . The accumulation of IL-8 in the culture medium of HMVEC-L was increased by SEA in a dose-dependent manner and was directly related to the number of PBMCs present . Although neither anti-human IL-8 nor IL-1 mAb inhibited HMVEC-L cytotoxicity, anti-human TNF-alpha mAb inhibited both the cytotoxicity and IL-8 accumulation completely . When HMVEC-L were incubated with supernatants from SEA-treated PBMCs, HMVEC-L cytotoxicity was comparable with HMVEC-L incubated with SEA and PBMCs at the same time . Although high concentrations of purified PMNs induced HMVEC-L lysis in a dose-dependent manner, the effect of PMNs was not changed in the presence of SEA . These findings suggest that TNF-alpha secreted by SEA-stimulated PBMCs plays a leading role in HMVEC-L injury.

Am J Kidney Dis, 1998 Nov, 32(5), 752 - 60
Effect of a silver device in preventing catheter-related infections in peritoneal dialysis patients: silver ring prophylaxis at the catheter exit study; Pommer W et al.; Catheter-related infections remain a significant cause of method failure in chronic peritoneal dialysis (PD) therapy . Given the increasing antibiotic resistance, such nonpharmacological strategies as local silver devices attract more interest . To establish whether a silver ring device (designed by Grosse-Siestrup in 1992) mounted onto the PD catheter and placed at the exit site at skin level is effective in preventing exit-site and other catheter-related infections, a prospective 12-month, multicenter, controlled study stratified by diabetes status was conducted . The study subjects were assessed by an extensive structured inventory, including a broad spectrum of control variables, such as age, body mass index (BMI), Staphylococcus aureus carrier status, catheter features, mode and quality of PD therapy, comorbidity, and psychosocial rehabilitation . Ten experienced German outpatient dialysis centers (seven adult, three pediatric) participated in the trial . All eligible patients (n=195) from the study area without catheter-related infections during the ascertainment period were included (incidental subjects undergoing PD therapy for at least 3 months) . The main outcome measures were the occurrence of first exit-site infections (primary study end point), sinus tract/tunnel infection, and peritonitis . Ninety-seven patients were assigned to the silver ring and 98 patients to the control group . Baseline characteristics of age, sex, proportion of pediatric and incidental patients, S aureus carrier status, and other variables were similar in both groups . The incidence of infections in the silver ring group versus the control group was as follows: 23 of 97 versus 16 of 98 patients had exit-site infections, 12 of 97 versus 12 of 98 patients had sinus tract/tunnel infections, 16 of 97 versus 18 of 98 patients had peritonitis, respectively . Kaplan-Meier analysis for the probability of an infection-free interval showed no statistical difference (log-rank test) between the two groups . Displacement of the silver ring contributed to study termination in 6% of the study group patients, including two patients with catheter loss . Univariate analysis and multiple logistic regression identified younger age (<50 years), low serum albumin level (<35 g/L), number of previously placed PD catheters, short cuff-exit distance (<2 cm), and S aureus nasal carriage as risk factors for the development of exit-site infections . In conclusion, our study does not show any benefit of the silver ring in preventing catheter-related infections in PD patients . Thus, prevention of infection-related method failure in PD still has to rely on conventional antibiotic treatment strategies and less so on alternative methods.

J Clin Lab Immunol, 1996, 48(4), 167 - 75
Serum levels of anti-Staphylococcus aureus-specific IgE in patients with atopic dermatitis; Yamada H et al.; We investigated the role of Staphylococcus aureus-specific IgE in patients with atopic dermatitis (AD) . The titer of serum S . aureus-specific IgE was measured using the RAST method in 67 patients with AD and correlated with serum LDH, eosinophil count and total IgE . The titer of S . aureus-specific IgE was elevated in 41 patients but was not detected in 26 patients . The mean serum level of total IgE was higher in the positive group than in the negative group, but the eosinophil count and LDH levels were not different between the two groups . S . aureus was detected and cultured from the skin of 33/41 (80%) patients in the positive group, but only from the skin of 5/26 (19%) patients of the negative group . Our results suggest that S . aureus-specific antibody is present in patients with moderate-to-severe atopic dermatitis and may be involved in the pathogenesis of AD.

J Infect, 1998 Jan, 36(1), 67 - 72
Methicillin-resistant Staphylococcus aureus: a questionnaire and microbiological survey of nursing and residential homes in Barking, Havering and Brentwood; Namnyak S et al.; The study determined the policies and procedures for the control and prevention of methicillin-resistant Staphylococcus aureus (MRSA) and its prevalence among nursing and residential homes, and evaluated whether certain home characteristics such as bed size, staffing level, and type of home are related to the prevalence of MRSA . A 21-questionnaire survey, with primarily categorical responses, was mailed to the home managers of all the 121 nursing and residential homes in the district, following which a simple, stratified random sample of 28 (23.14%) homes was taken and all agreeing residents screened from multiple sites for MRSA . Seventy-seven (63.6%) homes returned a completed questionnaire, 13 (46.4%) of whom agreed to participate in the microbiological study . The response rates for returning questionnaires and agreeing to participate in the microbiological study were similar for nursing and residential homes (65% vs . 60%; 67% vs . 40%; P = 0.12; P = 0.62), respectively . Nursing homes had a mean bed size of 30 (95% Confidence Interval (CI) 17-43), not significantly different from residential homes of 23 (95% CI 18-27; P = 0.26) . The nursing homes employed a mean of 8.6 (95% CI 4.7-12.5) staff nurses per home; significantly higher than residential homes with a mean of 1.6 (95% CI 0.3-2.8; P = 0.006) . No significant differences in mean number of home care assistants employed per home (22.8; 95% CI 12.4-33.13; and 14.4; 95% CI 11.83-16.90; P = 0.098, for nursing and residential homes, respectively) were observed . None of the homes had employed infection control practitioners . Only four (6.8%) of the responding homes stated that MRSA was a problem . Nursing homes were not significantly more likely to have admission policies for colonized person than residential homes (10/13 vs . 40/55, P = 1.00) . Of the fifty-five (71.4%) homes who had admission policies, 40 (72.7%) stated that persons colonized/infected with MRSA would not be accepted, while 12 (21.8%) would accept such persons in single-room isolation and/or barrier nursing . Greater proportions of residential homes than nursing homes would not accept admission of persons with documented MRSA colonization (30/35 vs . 4/10, P = 0.007) . Four (9.1%) homes (three nursing) had identified a total of five residents colonized/infected with MRSA in 5 years prior to the survey . Two hundred and forty-six residents were screened (552 sites), two (0.81%) of whom were found to be colonized in the nose (one resident) and in the groin (two residents) with MRSA, giving a 2-month weighted point prevalence rate of 0.14% (95% CI 0.01-0.26%) . We conclude that in our district the nursing staffing levels and control measures vary widely within these homes, while the prevalence of residents who are colonized/infected with MRSA is lower than in other areas . We suggest that the exclusion admission policy for MRSA positive patients should be abandoned and targeted infection control programmes be instituted.

Microb Drug Resist, 1998 Fall, 4(3), 247 - 56
Development of penicillin resistance among Staphylococcus aureus isolated from bovine mastitis in Denmark and other countries; Aarestrup FM et al.; This review gathers the published information regarding penicillin resistance among Staphylococcus aureus isolated from bovine mastitis from 43 different countries worldwide . For selected countries, trends over time are shown . The occurrence of resistance in the different countries is discussed in relation to the potential value of penicillin for therapy.

Microb Drug Resist, 1998 Fall, 4(3), 185 - 93
Conjugative transfer of high-level mupirocin resistance and the mobilization of non-conjugative plasmids in Staphylococcus aureus; Udo EE et al.; A 31-kb conjugative plasmid, pXU12, encoding high-level mupirocin resistance via the mupA gene, was isolated from a multiply resistant Staphylococcus aureus isolate, MB494 . pXU12 was derived by a deletion of an 8.6-kb EcoRI fragment from a approximately 40-kb plasmid in the parental isolate during curing and conjugation experiments . It transferred rapidly in conjugation experiments, with transconjugants being obtained after 15 min of mating, and mobilized a 3.0-kb erythromycin resistance plasmid, pXU13, from the parental isolate at high frequencies . The cotransfer of pXU13 by pXU12 was unaffected by varying the donor-recipient ratios in the mating mixtures or the length of incubation . pXU12 also mobilized 11 other nonconjugative plasmids belonging to different incompatibility groups and cotransferred at high frequencies . The ability of pXU12 to mobilize different nonconjugative plasmids suggested that it can be used to transfer and isolate non-conjugative plasmids from resistant S . aureus strains in the laboratory, especially from strains where phage-dependent methods of transfer are not applicable.

Microb Drug Resist, 1998 Fall, 4(3), 169 - 74
Macrolide antibiotic inhibition of translation and 50S ribosomal subunit assembly in methicillin-resistant Staphylococcus aureus cells; Champney WS et al.; Methicillin-resistant Staphylococcus aureus cells were treated with three macrolide antibiotics to examine the inhibitory effect of the drugs on the growth rate and cell viability . Inhibition of protein synthesis and 50S ribosomal subunit assembly were also examined . The growth rate and cell viability were reduced by each antibiotic in both erythromycin-susceptible and erythromycin-resistant MRSA organisms . Translation and the formation of the 50S ribosomal subunit were inhibited to an equal extent in the erythromycin-susceptible cells, but protein synthesis was affected to a greater extent by each macrolide in the erythromycin-resistant organisms . Clarithromycin was the most inhibitory of the three compounds, followed by erythromycin and azithromycin in relative effectiveness . The use of these compounds against MRSA organisms is discussed.

Microb Drug Resist, 1998 Fall, 4(3), 159 - 68
Suppression of glycopeptide resistance in a highly teicoplanin-resistant mutant of Staphylococcus aureus by transposon inactivation of genes involved in cell wall synthesis; Sieradzki K et al.; The teicoplanin-resistant laboratory mutant TNM of Staphylococcus aureus strain COL (minimal inhibitory concentration for teicoplanin increased from 3 to 200 microg/ml) produced an abnormal peptidoglycan in which the proportion of cross-linked oligomeric muropeptides (pentameric and higher than pentameric species), representing approximately 60% of all muropeptide species in the parental strain, was reduced to approximately 17% in the mutant . In parallel, there was an increase in the representation of the monomeric muropeptides from 4% (in the parent) to 20% in the resistant strain . The mutant cell wall showed greatly increased porosity for the detergent extraction of cytoplasmic proteins, and this property was abolished in a Tn551 insertional derivative of TNM, which was selected for reduced (parental level) teicoplanin resistance . Transposon inactivation of the global regulatory genes Sigma-B and sar, and several genes involved in early steps of staphylococcal peptidoglycan synthesis, all caused extensive reduction of teicoplanin resistance in mutant TNM, in some cases to levels close to or below the MIC value of the parental strain.

J Immunol Methods, 1998 Sep 1, 218(1-2), 161 - 7
A simple method for determining K(A)s of both low and high affinity IgG antibodies; O'Hare T et al.; A rapid and convenient method for measuring affinity constants (K(A)) of IgG antibody-hapten complexes is described . A key advantage of this method is its suitability for quantification of both low and high affinity interactions . A comparison is made of the K(A)s of the low affinity anti-phosphocholine (PC) antibody T15 (K(A) = 2.9 x 10(5) M(-1)) and five heavy chain complementarity determining region 2 (HCDR2) mutant antibodies expressed as IgG2b transfectants . As a demonstration of the general applicability of the technique, colchicine binding to the high affinity monoclonal IgG2a antibody C44 (K(A) = 1.5 x 10(9) M(-1)) is measured also; thus the assay is applicable over a four-log range of affinities . The assay, based upon use of fixed Staphylococcus aureus Cowan I strain cells as an adsorbent for antibody-radiolabeled antigen complexes, is conducted over a range of hapten concentrations at constant antibody concentration . The K(A) is obtained by Scatchard analysis.

J Antimicrob Chemother, 1998 Oct, 42(4), 427 - 37
In-vitro and in-vivo antibacterial activities of CS-834, a new oral carbapenem; Sakagawa E et al.; We evaluated the in-vitro and in-vivo antibacterial activities of R-95867 and CS-834, a new oral carbapenem which is an ester-type prodrug of R-95867 . Against Gram-positive bacteria, R-95867 was as active or two to 256 times more active than cefpodoxime, cefdinir, cefditoren and ofloxacin, while its activity was similar to or two to eight times lower than that of imipenem . Against most Gram-negative bacteria it was as active or two to 1024 times more active than the other compounds tested . Against Helicobacter pylori it was two to 64 times more active than orally active anti-H . pylori agents, i.e . amoxycillin, clarithromycin and lansoprazole . It also showed potent bactericidal activity against Staphylococcus aureus and Escherichia coli . R-95867 induced a spherical form in E . coli and showed high affinity for PBP 2 in E . coli . Against systemic infections in mice caused by various bacteria, CS-834 showed an excellent protective effect and its in-vivo efficacy correlated well with the in-vitro activity of R-95867 . These results suggest that CS-834 may be effective in the therapy of various bacterial infections.

Mayo Clin Proc, 1998 Nov, 73(11), 1083 - 4
Staphylococcus aureus meningitis in a patient with acquired immunodeficiency syndrome; Miller LG et al.; Meningitis due to Staphylococcus aureus is well described but uncommon . Most cases arise as a complication of neurosurgical interventions or head trauma, although some arise spontaneously . To our knowledge, no case of S . aureus meningitis has been previously reported in a person with the acquired immunodeficiency syndrome (AIDS) . Herein we describe a case of S . aureus meningitis in a person with AIDS who had no history of a neurosurgical procedure, head trauma, or overwhelming bacteremia . Treatment of this infection was successful . S . aureus should be added to the list of potential pathogens that can cause spontaneous meningitis in people with AIDS.

J Clin Microbiol, 1998 Dec, 36(12), 3707 - 9
Multicenter evaluation of a modified protocol for the RAPIDEC staph system for direct identification of Staphylococcus aureus in blood cultures; van Griethuysen A et al.; A modified protocol for the RAPIDEC Staph system (bioMerieux, Marcy-l'Etoile, France) for direct identification of Staphylococcus aureus in blood cultures was evaluated in a multicenter study . A total of 129 blood cultures (BACTEC 9000 Blood Culture System; Becton Dickinson Diagnostic Instrument Systems, Sparks, Md.) containing gram-positive cocci in clusters were analyzed by conventional methods and by RAPIDEC Staph in accordance with the manufacturer's protocol and in accordance with a modified protocol . The sensitivity, specificity, and positive and negative predictive values obtained with the manufacturer's protocol were 90.5, 97.7, 95 . 0, and 95.5%, respectively, and those obtained with the modified protocol were 100, 96.6, 93.3, and 100%, respectively . The modified protocol for the RAPIDEC Staph is easier to perform than the manufacturer's protocol and is very reliable.

J Clin Microbiol, 1998 Dec, 36(12), 3614 - 8
Nasal carriage of staphylococcus aureus and epidemiology of surgical-site infections in a Sudanese university hospital; Ahmed AO et al.; Surgical site infections (SSI) due to Staphylococcus aureus among 256 male and 158 female patients (mean age, 28 years) undergoing elective surgery at the Soba University Hospital (Khartoum, Sudan) were studied . During an 11-month study period all patients were analyzed for nasal carriage of S . aureus at the time of admission . Follow-up of the development of SSI proceeded until 4 weeks after the operations . In addition, nasal swabs were obtained periodically during the same period from 82 members of the staff . In order to discriminate autoinfection from cross infection, bacterial isolates were typed by random amplification of polymorphic DNA (RAPD), pulsed-field gel electrophoresis (PFGE) of DNA macrorestriction fragments, and restriction fragment length polymorphism analysis of the protein A and coagulase genes . Preoperative cultures revealed the presence of S . aureus in the noses of 98 patients (24%) . The overall number of postsurgical wound infections in the entire group was 57 (14%), 24 of which were due to S . aureus . Only 6 of the 98 nasal S . aureus carriers suffered from wound infections by the same species . In these six cases the infecting strain could not be genetically discriminated from the nasal inhabitant, substantiating autoinfection . However, nasal carriage of S . aureus is not a significant risk factor for the development of SSI in this setting (6 of 98 patients with autoinfection versus 18 of 316 patients {414 - 98 patients} with cross infection; P = 0.81), most probably due to the fact that noncarriers are at a significant and relatively large risk for acquiring an independent S . aureus SSI . The other S . aureus strains causing SSI showed a high degree of genetic heterogeneity, demonstrating that it is not an epidemic strain that is causing the SSI . Among the staff personnel screened, 47.4% did not carry S . aureus in the nose at any time during the study period, whereas 13 . 2% persistently carried a single strain in the nose . Another 39.5% could be classified as intermittent carriers . When strains derived from staff personnel were genetically typed, it was demonstrated that most of the strains represented genetic variants clearly differing from the isolates causing SSI . On the other hand, possible cross colonization among staff personnel and even cross infection from staff personnel to patients or from patient to patient were demonstrated in some cases, but epidemic spread of a single strain or a few clonally related strains of S . aureus could be excluded.

J Clin Microbiol, 1998 Dec, 36(12), 3532 - 9
Clonal distribution of methicillin-resistant Staphylococcus aureus in Poland; Leski T et al.; We report on a study of 158 methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates obtained from 1990 to 1996 in 18 different hospitals in Poland . All isolates were recovered from infection and carriage sites of patients, carriage sites of health care personnel, and hospital environment samples . Fifty-seven MRSA strains described here were studied previously and these were divided into two different clusters according to the degree of heterogeneity of methicillin resistance expression . The aim of this study was to extend the correlation between the two clusters and identify the clonal identities among all isolates by a combination of different methodologies: (i) analysis of mecA polymorphs and Tn554 insertion patterns and (ii) determination of pulsed-field gel electrophoresis patterns of chromosomal SmaI digests . Ninety-seven of 158 strains showed a heterogeneous expression of resistance to methicillin . Among these, 75 (77.3%) were ClaI-mecA type I, ClaI-Tn554 type NH (NH, no homology with transposon Tn554), and pulsed-field gel electrophoresis (PFGE) pattern A (I::NH::A); 10 isolates were III::B::M (10.3%); and the remaining clones included a few or single isolates . The isolates with homogeneous expression of resistance to methicillin (n = 61) were predominantly ClaI-mecA type III (49 of 61 {80.3%}) but had great variability in their ClaI-Tn554 and PFGE patterns . This study confirmed the existence of two main clusters of MRSA in Poland.

J Biol Chem, 1998 Nov 20, 273(47), 31145 - 52
The binding of calcium to the B-repeat segment of SdrD, a cell surface protein of Staphylococcus aureus; Josefsson E et al.; In the Sdr family of Staphylococcus aureus cell surface proteins, three recently cloned members (Josefsson, E., McCrea, K., Ni Eidhin, D., O'Connell, D., Cox, J . A., Hook, M., and Foster, T . (1998) Microbiology, in press) display variable numbers of B-repeats, i.e . segments of 110-113 residues that probably make up one folding unit . Each B-repeat contains one conserved EF-hand motif and two acidic stretches . Equilibrium dialysis revealed that segment B1-B5 of SrdD contains 14 Ca2+-binding sites with high affinity ({Ca2+}0.5, 4 microM), whereas flow dialysis yielded 5 sites of high affinity (class I) and 10 of low affinity (class II) . The discrepancy could be explained by the slow induction of high affinity in the class II sites . Kinetic experiments using fluorescent Ca2+ indicators corroborated slow binding of Ca2+ at the latter sites . Circular dichroism and Trp fluorescence showed that, whereas the Ca2+ form is well folded, the metal-free form seems strongly disorganized . The Ca2+-induced conformational changes comprise both fast and slow steps, giving thus a structural support for the induction of class II Ca2+-binding sites . The B-repeats may act as rulers or springs that modulate the distance between the interactive A region and the bacterial cell surface.

Lett Appl Microbiol, 1998 Oct, 27(4), 229 - 34
Antimicrobial substances produced by Staphylococcus aureus strains isolated from cattle in Brazil; de Oliveira SS et al.; Among 46 isolates of Staphylococcus aureus obtained from cattle in the State of Paraiba, Brazil, four were shown to produce antimicrobial substances (AMS) . The two best AMS producers carried single plasmids of about 8.0 kbp and 50 kbp, respectively, which were designated pRJ34 and pRJ35 . Curing experiments and molecular analysis associated the AMS production with the presence of these plasmids in the cells . The biochemical properties exhibited by the AMS suggested that they might be bacteriocins (Bac) . The bacteriocin encoded by pRJ34 showed properties identical to those of the bacteriocins encoded by other small staphylococcal Bac plasmids . However, the bacteriocin encoded by the large plasmid pRJ35 has shown some properties which distinguish it from the other bacteriocins of Staph . aureus described so far, suggesting it may be a new member of the staphylococcal bacteriocin family.

Zentralbl Bakteriol, 1995 Oct, 282(4), 519 - 32
Characteristics of Staphylococcus aureus strains isolated from clinical and non-clinical human sources in Trinidad: susceptibility to bacteriophages and antimicrobial agents, and toxigenicity; Adesiyun AA et al.; The susceptibility of Staphylococcus aureus strains isolated from human clinical and non-clinical sources in Trinidad to bacteriophages and antimicrobial agents was determined . The ability of the strains to produce enterotoxins and toxic shock syndrome toxin-1 (TSST-1) was also investigated . Of the 554 strains tested, 454 (81.8%) were susceptible to international phage set (IPS) phages with strains isolated from bacteruria (57.1%) and bacteremia (53.3%) having a low sensitivity compared to isolates from aspirates (87.3%) and anterior nares (97.4%) . All sources combined, strains were most susceptible to phages belonging to several groups (mixed) . Overall, 419 (75.6%) strains were resistant to one or more of nine antimicrobial agents tested . Resistance to penicillin was most prevalent, with 413 (74.5%) strains found to be resistant . Prevalence of resistance to tetracycline, gentamicin, oxacillin, cefuroxime and ciprofloxacin was 5.1%, 2.0%, 0.7%, 0.4% and 0.4%, respectively . Of the 554 strains tested, 307 (55.4%) produced staphylococcal enterotoxins A (SEA), B (SEB), C (SEC) and D (SED) singly or in combination . Strains recovered from high vaginal swabs were least enterotoxigenic (40.0%) as compared to umbilical infection isolates which were most enterotoxigenic (78.9%) . TSST-1 was produced by 95 (19.0%) out of 499 strains tested, with isolates from bacteruria found to be most toxigenic (33.3%) . It was concluded that the S . aureus strains tested were highly susceptible to bacteriophages and antimicrobial agents (except penicillin) and that enterotoxigenic and TSST-1 producers were widespread and have an aetiologic potential.

Zentralbl Bakteriol, 1995 Oct, 282(4), 367 - 71
Detection of staphylococcal enterotoxin B and toxic shock syndrome toxin: PCR versus conventional methods; Schumacher-Perdreau F et al.; An equal accuracy of commercially available kits, i.e., the reverse passive latex agglutination test (RPLA-Oxoid) and the Enzyme-Linked Immunosorbent Assay (SET-EIA Riedel Haen, Germany) to identify the presence of the staphylococcal enterotoxin B and the toxic shock syndrome toxin TSST-1 as well as the PCR-technique to detect the presence of the seb and tst-genes was demonstrated in 18 Staphylococcus aureus isolates . Selection of a primer pair from the etb gene sequence allowing simultaneously detection of the etb and tst-genes in S . aureus using a rapid DNA extraction method is emphasized.

Zentralbl Bakteriol, 1995 Nov, 283(1), 90 - 4
Respiratory burst of human polymorphonuclear leukocytes in response to the galactoside-specific mistletoe lectin; Braun JM et al.; The phagocytic activity of human polymorphonuclear leukocytes (PMNLs) towards Staphylococcus aureus Cowan 1 was evaluated in chemiluminescence assays . As to check its activating ability, galactoside-specific mistletoe lectin (ML-1) was coincubated with PMNLs which were then challenged with S . aureus . Statistically significant (p < 0.001) chemiluminescent response (correlating with phagocytic activity) could be demonstrated at optimal experimental condition, viz: 1 x 10(6) PMNLs incubated with 0.005 ng ML-1 for 30 and 60 minutes before S . aureus challenge . Other experimental schedules (different timing and PMNL/ML-1 concentrations) did not present with statistically relevant changes in chemiluminescent response . These studies suggest that optimal ML-1 concentrations enhance the phagocytic activity of PMNLs which might be of benefit in thus treated patients as to prevent (or lower the rate of) infections under antineoplastic therapy.

J Spinal Disord, 1998 Oct, 11(5), 452 - 3
Septic arthritis of a lumbar facet joint: report of a case with early MRI findings; Fujiwara A et al.; A 56-year-old man was hospitalized with a 2-day history of back pain and fever . A magnetic resonance (MR) scan taken on admission showed a facet joint effusion and soft-tissue abnormality posterior to the joint . Follow-up MR imaging confirmed the facet joint destruction and periarticular abscess . A biopsy specimen grew Staphylococcus aureus . MR imaging is helpful in detecting this rare infection in the earliest phase of the disease.

Cent Afr J Med, 1998 Apr, 44(4), 102 - 4
Septicaemia in sickle cell anaemia patients: the Ibadan experience; Aken'ova YA et al.; OBJECTIVE: To describe the pattern of septicaemia among sickle cell anaemia patients . DESIGN: Descriptive study . SETTING: Haematology Day Care Unit of the University College Hospital, Ibadan, Nigeria . SUBJECTS: 269 patients with sickle cell anaemia who presented with fever greater than 38 degrees C . RESULTS: The blood of 97 of the patients exhibited positive growth with isolation of bacteria thereby confirming the diagnosis of septicaemia in them . Fifty seven (59%) of the isolates were gram negative while 40 (41%) were gram positive pathogens . Klebsiella sp . was the predominant gram negative bacteria while Staphylococcus aureus was the predominant gram positive bacteria . The sensitivity tests on the isolates confirmed Ceftozidine (Fortum) was the most effective antibacterial agent for the gram negative and gram positive pathogens . The 172 patients, who had no bacteria pathogens isolated did well with prophylactic broad spectrum antibiotics . Thirty one patients with positive malarial parasites had full anti-malarial therapy . CONCLUSION: The incidence of gram negative septicaemia is high in patients with sickle cell anaemia . Klebsiella spp . is the predominant gram negative bacterium while Staphylococcus aureus is the predominant gram positive bacterium . Ceftozidine appears to be the most effective antibiotic against both the gram positive and gram negative bacterial infection.

Ugeskr Laeger, 1998 Oct 26, 160(44), 6357 - 8
{Spread of methicillin-resistant Staphylococcus aureus . Are our hygienic precautions sufficient?}; Lykke J et al.; A patient was transferred from Pakistan to a Danish orthopaedic ward . In Denmark he was tested MRSA-positive . Two months after he was discharged, similar MRSA strains were found in another patient . The two patients had been on the same ward for one week . All hygienic precautions had been taken . Staff and other patients on the ward at the relevant time all tested MRSA-negative.

Genome, 1998 Oct, 41(5), 709 - 19
Isolation and preliminary characterization of histone H1.b allelic variants from quail erythrocytes; Palyga J et al.; Our goal was to purify and characterize the allelic variants H1b1 and H1b2 of histone H1.b, one of the seven subtypes of this linker histone extracted from Japanese quail erythrocyte nuclei . These variants are revealed phenotypically as band H1.3 or part of band H1.4 by polyacrylamide gel electrophoresis (PAGE) in sodium dodecyl sulfate (SDS) . All H1 subtypes together were separated from H5 by gel-permeation chromatography through Bio-Gel P-150 . H1 was then fractionated on a column of the cation-exchange resin Amberlite CG-50 by using a shallow guanidine hydrochloride gradient, which enriched subtype H1.b together with H1.z and overlapping with subtypes H1.a and H1.b . Alternatively purification of subtypes was achieved electrophoretically: total H1 fractions from quail with different H1 phenotypes were first resolved into sub-types by PAGE in acetic acid-urea; after staining, the appropriate H1.b bands from several parallel gel pieces were excised and the histone was concentrated by PAGE in SDS . After fragmentation of H1.b in the gel pieces with N-bromosuccinimide (NBS), PAGE in SDS indicated no difference between H1b1 and H1b2 in the C-terminal "half" of the polypeptides . In contrast, limited digestion with endoprotease V8 from Staphylococcus aureus has shown that differences, probably by a few residues in length, reside in the N-terminal part of the molecule, close to the amino-terminus.

FEMS Microbiol Lett, 1998 Oct 15, 167(2), 221 - 7
A plasmid that encodes three genes for resistance to macrolide antibiotics in Staphylococcus aureus; Matsuoka M et al.; In previous letters, FEMS Microbiol . Lett . 148 (1997) 91-96, it was demonstrated that plasmid pMS97-obtained from a in 1971 clinically isolated Staphylococcus aureus strain MS8968 resistant to macrolide (Mac) antibiotics--carried an msrA gene and uncharacterized erm gene, respectively . msrA encodes a cytoplasmic membrane protein that mediates the so-called 'active Mac-efflux' (designated hereafter as msrSA') and erm encodes a methyltransferase by which a specific adenine residue of 23S rRNA is modified: methylation prevents Mac antibiotics from binding to the 50S ribosomal subunit . Interestingly, we found, in addition, an mph-like gene (hereafter referred to as mphBM) present together with msrSA' and erm on pMS97 . By a BLASTP analysis, the gene mphBM product has 49% identity and 67% similarity to the amino acid sequence of MPH(2')II encoded by mphB from Escherichia coli . The order of genes was 5'-msrSA'-mphBM-3', with a 342-base-pair spacer sequence . Although we have not yet determined where erm gene is located on pMS97, the gene seems to be downstream from mphBM . This finding suggests a warning to us concerning the imprudent use of antibiotics.

Acta Anaesthesiol Scand, 1998 Oct, 42(9), 1096 - 9
Bactericidal activity of preservative-free bupivacaine on microorganisms in the human skin flora; Sakuragi T et al.; BACKGROUND: The rate at which the bactericidal activity of preservative-free bupivacaine develops at body temperature and at room temperature is not known . We studied the bactericidal activity of preservative-free bupivacaine on two strains of methicillin-resistant Staphylococcus aureus (MRSA), two strains of methicillin-susceptible S . aureus (MSSA), and each of Staphylococcus epidermidis and Escherichia coli . METHODS: The pathogen was exposed to 0.5% bupivacaine for 1, 3, 6, 12, and 24 h at 37 degrees C and room temperature . In addition, each strain of MRSA, MSSA, and S . epidermidis was exposed to distilled water, and 0.125%, 0.25%, 0.5%, and 0.75% bupivacaine at 37 degrees C . The inocula from the suspensions were cultured for 48 h at 37 degrees C . RESULTS: The 1- through 24-h exposures of 4 strains of S . aureus to 0.5% bupivacaine at room temperature reduced the colony count by 21.7%, 34.7%, 51.1%, 65.6%, and 81.1%, respectively, and the exposure at 37 degrees C reduced the count by 34.1%, 50.8%, 66.3%, 94.5%, and 96.0%, respectively . The differences were significant at all exposure times (P < 0.001, respectively) . No organisms grew in the strain of E . coli after 24-h exposure and in the strain of S . epidermidis after 12- and 24-h exposures at 37 degrees C . The percent change from controls in the strains of E . coli and S . epidermidis was significantly higher than that in the strains of S . aureus at all exposure times at room temperature and 37 degrees C (P < 0.0001, respectively) . Higher concentrations of bupivacaine were associated with lower colony count . CONCLUSION: Our results show that preservative-free bupivacaine possesses a temperature- and concentration-dependent bactericidal activity, and S . aureus is more resistant to the bactericidal activity of bupivacaine than are S . epidermidis and E . coli.

Dtsch Med Wochenschr, 1998 Oct 16, 123(42), 1235 - 8
{Fever, negative blood culture findings and absence of response to antibiotic therapy in a patient after a second aortic valve prosthesis}; Miljak T et al.; HISTORY AND CLINICAL FINDINGS: A 53-year-old patient had a prosthetic valve (St . Jude Medical 25) 9 years ago because of a Staphylococcus aureus endocarditis with severe aortic regurgitation . An initially mild, progressively more severe, aortic regurgitation then developed as a result of an empty paravalvular abscess cavity, requiring another valve replacement . Fever started on the 3rd postoperative day and persisted despite combined treatment with beta-lactam antibiotics and aminoglycoside . INVESTIGATIONS: At first no infectious focus could be identified radiologically or by echocardiography . But transoesophageal echocardiography revealed vegetations in the old abscess cavity . Several blood cultures were negative, while serological tests gave markedly raised antibody titers against Coxiella burnetii . DIAGNOSIS, TREATMENT AND COURSE: Assuming Coxiella burnetii endocarditis the patient was given doxycycline, 2 x 100 mg daily and cotrimoxazole, 1 x 960 mg daily . The fever subsided and the vegetations had disappeared after four weeks . Because of the high risk of recurrence the antibiotic treatment was to be continued for two years . CONCLUSION: Coxiella burnetii should be considered as a possible cause of fever of unknown origin, especially in patients with existing or operated cardiac valvar defects, when endocarditic vegetations have been demonstrated and several blood cultures have been negative.

APMIS, 1998 Sep, 106(9), 901 - 8
Virulence factors of Staphylococcus aureus strains causing infective endocarditis--a comparison with strains from skin infections; Hogevik H et al.; The objective was to study potential bacterial virulence factors in S . aureus endocarditis . S . aureus strains isolated from patients with well-classified episodes of infective endocarditis (IE) (n=26) were compared with control S . aureus strains from consecutive patients with skin infections (n=30) . The potential virulence factors studied were Staphylococcal enterotoxin A-D (SEA, SEB, SEC, SED) and toxic shock syndrome toxin-1 (TSST-1) production and binding capacity to the extracellular matrix proteins: fibronectin, collagen type I, collagen type II and bone sialoprotein (BSP) . None of the potential virulence factors studied was more prevalent among the IE strains . BSP binding was more often found in the control group with skin infections . Endocarditis patients with previous damage of the heart valves were more often infected by strains not producing any enterotoxin . No correlation was found between the potential bacterial virulence factors studied and IE . Concerning the toxins known to act as superantigens (SEA-E and TSST-1), the tendencies in this and other studies indicate that a larger study group might identify them as pathogenic factors in a subgroup of staphylococcal endocarditis.

Curr Microbiol, 1998 Dec, 37(6), 418 - 25
Inhibition of translation and 50S ribosomal subunit formation in Staphylococcus aureus cells by 11 different ketolide antibiotics; Champney WS et al.; Eleven structurally similar ketolide antibiotics were tested at a concentration of 1 microg/ml for their relative inhibitory effects on growth and ribosome activities in Staphylococcus aureus cells . Ten of the compounds examined had an inhibitory effect on protein synthesis at this concentration and eight of the 11 compounds were also effective inhibitors of the formation of the 50S ribosomal subunit . All of the drugs tested inhibited protein synthesis to a greater extent than they affected 50S subunit formation . The decline in growth rate and cell number was proportional to the effect on ribosome formation and function . The growth of an ermC erythromycin-resistant strain of S . aureus was also significantly inhibited by nine ketolide compounds, suggesting that they were not inducers of methylase gene expression . These inhibitory activities can be related to structural differences between these ketolide antibiotics.

Curr Microbiol, 1998 Dec, 37(6), 412 - 7
A comparison of the inhibition of translation and 50S ribosomal subunit formation in Staphylococcus aureus cells by nine different macrolide antibiotics; Champney WS et al.; Nine structurally similar macrolide antibiotics were tested at a concentration of 0.5 microg/ml for their relative inhibitory effects on ribosome functions in Staphylococcus aureus cells . Eight of the compounds examined inhibited protein synthesis at this concentration . Seven of the nine compounds were also effective in blocking formation of the 50S ribosomal subunit . Roxithromycin and 14-hydroxy clarithromycin inhibited protein synthesis to a greater extent than they affected 50S subunit formation . Conversely, the compound 11, 12-carbonate-3 deoxy-clarithromycin affected 50S assembly more than translation . Only clarithromycin had any effect on 30S ribosomal subunit assembly . The decline in growth rate and cell number was proportional to the effect on ribosome formation or function by each compound . These inhibitory activities can be related to structural differences between these macrolide antibiotics.

Clin Rheumatol, 1998, 17(5), 407 - 8
Methicillin-resistant Staphylococcus aureus septic arthritis: urgent and emergent; Byrne PA et al.; A 71-year-old male rheumatoid patient presented with MRSA septic arthritis . The impact of this organism on musculoskeletal practice is discussed.

Biochim Biophys Acta, 1998 Nov 11, 1414(1-2), 108 - 26
The interaction of Staphylococcus aureus bi-component gamma-hemolysins and leucocidins with cells and lipid membranes; Ferreras M et al.; Staphylococcus aureus gamma-hemolysins (HlgA, HlgB and HlgC) and Panton-Valentine leucocidins (LukS-PV and LukF-PV) are bi-component toxins forming a protein family with some relationship to alpha-toxin . Active toxins are couples formed by taking one protein from each of the two subfamilies of the S-components (LukS-PV, HlgA and HlgC) and the F-components (LukF-PV and HlgB) . We compared the mode of action of the six possible couples on leukocytes, red blood cells and model lipid membranes . All couples were leucotoxic on human monocytes, whereas only four couples (HlgA+HlgB, HlgC+HlgB, LukS-PV+HlgB and HlgA+LukF-PV) were hemolytic . Toxins HlgA+HlgB and HlgC+HlgB were also able to induce permeabilisation of model membranes by forming pores via oligomerisation . The presence of membrane-bound aggregates, the smallest and most abundant of which had molecular weight and properties similar to that formed by alpha-toxin, was detected by SDS-PAGE . By infrared spectroscopy in the attenuated total reflection configuration (FTIR-ATR), the secondary structure of both components and of the aggregate were determined to be predominantly beta-sheet and turn with small variations among different toxins . Polarisation experiments indicated that the structure of the membrane complex was compatible with the formation of a beta-barrel oriented perpendicularly to the plane of the membrane, similar to that of porins . The couple LukS-PV+LukF-PV was leucotoxic, but not hemolytic . When challenged against model membranes it was able to bind to the lipid vesicles and to form the aggregate with the beta-barrel structure, but not to increase calcein permeability . Thus, the pore-forming effect correlated with the hemolytic, but not with the complete leucotoxic activity of these toxins, suggesting that other mechanisms, like the interaction with endogenous cell proteins, might also play a role in their pathogenic action.

Biochim Biophys Acta, 1998 Nov 11, 1414(1-2), 65 - 74
Identifying the cholesterol binding domain in the nicotinic acetylcholine receptor with {125I}azido-cholesterol; Corbin J et al.; A novel photoreactive analog of cholesterol, 3alpha-(4-azido-3-{125I}iodosalicylic)-cholest-5-ene ({125I}azido-cholesterol), was used to label both native acetylcholine receptor (AChR)-rich membranes from Torpedo californica and affinity-purified Torpedo AChRs reconstituted into lipid vesicles . In both cases all four AChR subunits incorporated {125I}azido-cholesterol on an equal molar basis and neither the pattern nor the extent of labeling was affected by the presence of the agonist carbamylcholine . Labeled regions in each of the AChR subunits were initially mapped by Staphylococcus aureus V8 protease digestion to large fragments which contain the AChR transmembrane segments . Sites of {125I}azido-cholesterol incorporation were further mapped by exhaustive tryptic digestion of the V8 protease subunit fragments alphaV8-20 (alphaSer-173-Glu-338), alphaV8-10 (alphaAsn-339-Gly-439), and gammaV8-14 (gammaLeu-373-Pro-489) . The digests were separated by reverse-phase high-performance liquid chromatography and labeled peptides identified by amino-terminal sequence analysis . {125I}Azido-cholesterol labeling was localized to peptides that contain almost exclusively the alpha-M4, alpha-M1 and gamma-M4 membrane spanning segments . These results establish that the binding domain for cholesterol is at the lipid-protein interface of the AChR.

East Afr Med J, 1998 Jul, 75(7), 402 - 5
Surgical wound infection in a teaching hospital in Ethiopia; Kotisso B et al.; The magnitude and pattern of surgical wound infection in a teaching hospital in Gondar, northwest Ethiopia, was studied prospectively over a one year period . Out of 129 abdominal surgical wounds from 129 patients, fifty (38.7%) yielded pathogenic organisms on culture . The wound infection rate was 21% on clinical grounds alone . Wound infection was significantly associated with class of wound; with the highest rate being 61.4% for contaminated or dirty wound . There was no difference in infection rate between emergency and elective operations . Staphylococcus aureus and Escherichia coli were the leading aetiologic agents with rates of 28.8% and 27.1% of pathogenic isolates respectively . Surgical wound infection accounted for delay in the discharge of 14.7% of patients . This study has shown that the surgical wound infection rate in this teaching and tertiary level care hospital is high and control measures should be re-evaluated.

Microbiol Immunol, 1998, 42(9), 655 - 9
Expression analysis of the autolysin gene (atl) of Staphylococcus aureus; Oshida T et al.; The bifunctional autolysin gene (atl) of Staphylococcus aureus was transcribed into a 4.1-kb transcript . The transcription initiation site was located at an adenine residue 33-nt upstream from the putative atl start codon . Analysis using a promoter-reporter plasmid showed that promoter activity increased during the exponential growth phase . The Tn551 insertion site of the autolysis-deficient mutant S . aureus RUSAL2 was located in the putative catalytic region of the glucosaminidase domain.

Biochemistry, 1998 Nov 3, 37(44), 15423 - 33
Domain structure of the Staphylococcus aureus collagen adhesin; Rich RL et al.; Sequence analysis of surface proteins from Gram-positive bacteria indicates a composite organization consisting of unique and repeated segments . Thus, these proteins may contain discrete domains that could fold independently . In this paper, we have used a panel of biophysical methods, including gel permeation chromatography, analytical ultracentrifugation, circular dichroism, and fluorescence spectroscopy, to analyze the structural organization of the Staphylococcus aureus collagen adhesin, CNA . Our results indicate that the structure, function, and folding of the ligand-binding domain (A) are not affected by the presence or absence of the other major domain (B) . In addition, little or no interaction is observed between the nearly identical repeat units within the B domain . We propose that CNA is indeed a mosaic protein in which the different domains previously indicated by sequence analysis operate independently.

J Thorac Imaging, 1998 Oct, 13(4), 261 - 70
Bacterial pneumonia in immunocompromised patients; Conces DJ Jr; Immunocompromised patients develop infections resulting from a wide range of organisms . The most commonly encountered type of infection is bacterial in origin . Many of the infections are community-acquired pneumonias in which most of the infections are caused by organisms that typically produce disease in the healthy person . Hospital-acquired pneumonias are particularly serious, being caused by the highly virulent gram-negative bacilli and Staphylococcus aureus . Immunocompromised patients frequently have indwelling intravascular catheters . These catheters may become infected and seed the lung with septic emboli, producing a hematogenous pneumonia . Underlying conditions and therapy increase the risk for aspiration in the immunocompromised patient . These aspirations can result in the development of an aspiration pneumonia and lung abscess formation . The majority of pneumonias resulting from Legionella and Nocardia occur in immunocompromised patients.

Acta Orthop Scand, 1998 Aug, 69(4), 412 - 4
Prophylactic mupirocin could reduce orthopedic wound infections . 1,044 patients treated with mupirocin compared with 1,260 historical controls; Gernaat-van der Sluis AJ et al.; We analyzed the effect of perioperative elimination of nasal carriage of Staphylococcus aureus using mupirocin nasal ointment on the reduction of the postoperative wound infection rate in orthopedics . In an unblinded intervention trial, we compared 1,044 patients treated with mupirocin (intervention group) with 1,260 historical controls (control group) . From each group a random sample of 50 patients was taken . Risk factors were analyzed in these random samples and we found it unlikely that different distributions of risk factors might have influenced the results . The wound infection rates were 14/1,044 in the intervention group and 34/1,260 in the control group (p = 0.02) . The rates of wound infections caused by S . aureus were subsequently 7/1,044 and 14/1,260 (p = 0.3) . On checking the data we found that prophylaxis had unintentionally not been given to 172 patients in the intervention group . Correction of the data gave a comparable total infection rate, but a further reduced infection rate by S . aureus . Our findings suggest that prophylactic treatment with mupirocin in orthopedic surgery can reduce the infection rate.

Zhonghua Yi Xue Za Zhi (Taipei), 1998 Sep, 61(9), 513 - 9
Management of descending necrotizing mediastinitis; Fu YL et al.; BACKGROUND: Descending necrotizing mediastinitis (DNM) is uncommon, and may be lethal if not treated adequately and promptly . Delayed diagnosis of the disease is sometimes encountered in clinical practice . METHODS: Eight consecutive patients with acute DNM were identified between 1991 and 1995, including five men and three women . The mean age was 45.8 years (range, 22-71 years) . The infectious sources consisted of six esophageal perforations, one cervical cutting injury and one tonsillitis . The clinical presentations were evaluated . Diagnostic procedures including chest radiograph, sonogram and computerized tomography scans of the chest and neck were examined . Diagnosis and treatment, including culture results from drained fluids and debrided tissues, and antibiotic and supportive therapies were reviewed . RESULTS: Six patients who underwent aggressive surgical treatment recovered well . Two patients who received supportive treatment died of sepsis alone . The cultured bacteria included: Klebsiella oxytoca, Staphylococcus aureus, Trichosporum and other mixed oral cavity flora . CONCLUSIONS: Early diagnosis and adequate antibiotic and support therapies are essential to achieve good patient outcomes in acute descending mediastinitis . Adequate drainage and debridement, appropriate antibiotic therapy, and sufficient nutritional and respiratory support are the main treatment elements.

J Food Prot, 1998 Oct, 61(10), 1384 - 6
Characterization of staphylococcal bovine mastitis isolates using the polymerase chain reaction; Lee SU et al.; A polymerase chain reaction (PCR) assay was adapted to detect toxin genes of staphylococcal isolates from cases of bovine mastitis . Samples were obtained from three geographical areas: Korea and Idaho and Washington in the northwest United States . Samples from Korea and Washington were randomly chosen . Idaho samples were from a prospective study of mastitis etiology . Forty-one milk samples from 25 commercial farms in south-central Idaho were collected from cows with symptoms of mastitis . Although Staphylococcus aureus constituted 37.5% of mastitis isolates, these isolates lacked genes for staphylococcal enterotoxins (SEs), toxic shock syndrome toxin, and exfoliative toxins . In contrast, 4 of 13 isolates from Washington and 6 of 20 isolates from South Korea expressed SEs . These results suggest that PCR may be an effective means of screening bovine isolates for toxins . They also emphasize the potential for significant geographic differences in mastitis etiology.

Can J Vet Res, 1998 Oct, 62(4), 293 - 8
Avirulence and immunogenicity in mice of a bovine mastitis Staphylococcus aureus mutant; Bogni C et al.; An avirulent mutant, designated RC122, was derived from Staphylococcus aureus bovine mastitis strain RC108 after N-methyl-N'-nitro-N-nitrosoguanidine mutagenesis . Mutant RC122, which was isolated on the basis of reduced colony size, showed diminished virulence in mice (LD50 of RC122: 3.1 x 10(10) cfu vs LD50 of RC108: 2.3 x 10(7) cfu) . Mutant RC122 grew more slowly than its parental strain and showed decreased production of several exoproteins, such as alpha- and beta-hemolysin, DNAse and coagulase . The production of its capsule was induced only under in vivo growth conditions . Clearance studies performed in the mouse kidney revealed that the kinetics of disappearance of the mutant was similar to that of its parental strain . Protection experiments carried out by intraperitoneal administration in mice showed that mutant RC122 conferred a good degree of protection from challenge with homologous and heterologous strains.

Arch Dis Child, 1998 Aug, 79(2), 179 - 80
Endocarditis as the first presentation of AIDS in infancy; van Doorn CA et al.; A two month old Ugandan boy underwent surgery for an obstructive right ventricular vegetation associated with disseminated Staphylococcus aureus infection . Both the child and his mother subsequently tested positive for HIV infection . Very little is know about the incidence of endocarditis in paediatric patients with AIDS . To our knowledge this is the first case reported of disseminated S aureus infection associated with endocarditis and an obstructing vegetation in an HIV positive infant with a structurally normal heart . The initial signs and symptoms for endocarditis were atypical, a reflection of the overwhelming infection in an immunocompromised patient . Severe infections may have an atypical presentation in immunosuppressed patients . AIDS needs to be considered in these patients, especially if they come from populations with endemic HIV infection.

Appl Environ Microbiol, 1998 Nov, 64(11), 4264 - 8
rRNA stability in heat-killed and UV-irradiated enterotoxigenic Staphylococcus aureus and Escherichia coli O157:H7; McKillip JL et al.; Differentiation of viable cells from nonviable cells is of considerable importance in the development of methods to detect foodborne pathogens . To study the suitability of 16S rRNA as an indicator of cell viability in nucleic acid-based detection assays, we examined rRNA stability in two representative foodborne pathogens, Escherichia coli O157:H7 and enterotoxigenic Staphylococcus aureus, which were inactivated by extreme heat, moderate heat, and UV irradiation . Cell death under all conditions was confirmed by a failure to grow in brain heart infusion broth after incubation for 48 h at 37 degrees C . rRNA stability was monitored by a Northern blot analysis, and detection was evaluated by using reverse transcription (RT)-PCR performed with two primer sets (which produced 325- and 1, 400-bp amplicons) . rRNA of neither pathogen was detected by Northern blot analysis and RT-PCR after cells were killed by autoclaving at 121 degrees C for 15 min . In contrast, intact rRNA of both pathogens were detected by Northern blotting and could be amplified by RT-PCR up to 48 h after cells were killed by heat treatment at 80 degrees C and UV irradiation at 254 nm . rRNA was a suitable target molecule for monitoring bacterial viability under extreme heat conditions, but the presence of rRNA was not correlated with viability following moderate heat inactivation or UV irradiation of cells.

Antimicrob Agents Chemother, 1998 Nov, 42(11), 3044 - 6
Quinolone resistance mutations in the GrlB protein of Staphylococcus aureus; Tanaka M et al.; Two altered GrlB proteins (one with an Asp-432-->Asn alteration and one with an Asn-470-->Asp alteration) of Staphylococcus aureus were purified as fusion proteins to maltose-binding protein . The 50% inhibitory concentrations of levofloxacin were 14 and 3.4 microg/ml against topoisomerase IV containing GrlB proteins with alterations at positions 432 and 470, respectively . These results suggest that the alteration of Asp to Asn at position 432 may be responsible for quinolone resistance.

Antimicrob Agents Chemother, 1998 Nov, 42(11), 3024 - 7
Characterization of erythromycin-resistant isolates of Staphylococcus aureus recovered in the United States from 1958 through 1969; Nicola FG et al.; We tested 16 erythromycin-resistant clinical isolates of S . aureus, recovered from patients hospitalized in the United States from 1958 to 1969, for the presence of ermA, ermB, and ermC by using PCR . Fifteen of 16 isolates contained at least one copy of ermA; the remaining isolate, which was also clindamycin resistant, contained ermB . Eight of the 15 isolates harboring ermA, all of which were inducible, contained a single copy of the gene in the chromosome, while the remaining seven isolates had two copies of the gene . ermB was plasmid encoded and mediated constitutive resistance to erythromycin.

Antimicrob Agents Chemother, 1998 Nov, 42(11), 2817 - 23
Effects of subinhibitory concentrations of antibiotics on alpha-toxin (hla) gene expression of methicillin-sensitive and methicillin-resistant Staphylococcus aureus isolates; Ohlsen K et al.; Concentrations of antibiotics below the MIC are able to modulate the expression of virulence-associated genes . In this study, the influence of subinhibitory doses of 31 antibiotics on the expression of the gene encoding the staphylococcal alpha-toxin (hla), a major virulence factor of Staphylococcus aureus, was investigated with a novel gene fusion protocol . The most striking observation was a strong induction of hla expression by subinhibitory concentrations of beta-lactams and an almost complete inhibition of alpha-toxin expression by clindamycin . Whereas glycopeptide antibiotics had no effect, the macrolide erythromycin and several aminoglycosides reduced and fluoroquinolones slightly stimulated hla expression . Furthermore, Northern blot analysis of hla mRNA and Western blot (immunoblot) analysis of culture supernatants of both methicillin-sensitive and methicillin-resistant S . aureus strains revealed that methicillin-induced alpha-toxin expression is a common phenomenon of alpha-toxin-producing strains . Some methicillin-resistant S . aureus isolates produced up to 30-fold more alpha-toxin in the presence of 10 microg of methicillin per ml than in its absence . The results indicate that the novel gene fusion technique is a useful tool for studying the modulation of virulence gene expression by antibiotics . Moreover, the results suggest that the effects of certain antibiotics on virulence properties may be relevant for the management of S . aureus infections.

Jpn J Thorac Cardiovasc Surg, 1998 Sep, 46(9), 915 - 8
{A case report of infective endocarditis caused by MRSA and characterized by pedicled vegetation on the posterior wall of left atrium}; Yuda A et al.; We report here a case of active infective endocarditis caused by Methicilin-Resistant Staphylococcus aureus (MRSA) . A 24-year-old woman was admitted to the Osaka Medical Collage Hospital with continuous fever . After admission, MRSA was detected by blood culture and chemotherapy with Vancomycin was started . However, after 1 week, her condition had not improved . Moreover, a pedicled vegetation on the posterior wall of the left atrium and mitral regurgitation due to prolapse of the anterior leaflet were revealed by transesophageal echocardiography . The vegetation grew to about 2 cm in diameter and prolapsed into the left ventricle during diastole . We performed an early operation although the infection was still active due to its rapid growth and the risk of embolism . There was a large pedicled vegetation on the posterior wall of the left atrium as shown by preoperative echocardiography, but the mitral valve appeared to be intact . Therefore, the vegetation was completely removed and the mitral annulus was plicated by Kay's method to treat the associated mitral regurgitation . Postoperatively, we administered VCM 2 g/day for 24 days . The course was uneventful . The patient was discharged from the hospital on the 31st postoperative day.

Kansenshogaku Zasshi, 1998 Sep, 72(9), 924 - 34
{In vitro specific binding of Shiga toxin 1 and 2 by TAK-751S (Gb3 analog)}; Takeda T et al.; TAK-751S is a synthetic trisaccharide coupled to Chromosorb P using a spacer sequence of 8-methoxycarboyloctyl (MCO) . Its chemical structure is similar to a human receptor (Gb3) of Stx produced by enterohemorrhagic Escherichia coli (EHEC) . In vitro efficacy of TAK-715S was studied by using ACHN cultured cell assay, which is sensitive and specific for measuring low level of Stx . Under various conditions, TAK-715S was mixed with purified Stx1 and Stx2, and residual free toxins in the solution were measured by using ACHN cells . TAK-715S was demonstrated to bind specifically to Stx1 and Stx2 under the condition similar to a human intestine while Chromsorb P did not bind to any Stx . The binding activity was stable in the presence of various processed foods, fresh vegetables and fruits . Antibiotics such as fosfomycin, kanamycin and norfloxacin did not disturb its binding capability . Minimum inhibitory concentrations of these antibiotics against Staphylococcus aureus FDA209P or E . coli NIHJ JC-2 neither changed after incubating with TAK-751S for 60 min at 37 degrees C . These results suggest that TAK-751S can be given orally with various foods and antibiotics for the elimination of Stx1 and Stx2 in the gut of patients with EHEC infections.

Am J Infect Control, 1998 Oct, 26(5), 513 - 21
Changes in bacterial flora associated with skin damage on hands of health care personnel; Larson EL et al.; In a prospective observational study of 40 nurses (20 with diagnosed hand irritation and 20 without), nurses with damaged hands did not have higher microbial counts (P = .63), but did have a greater number of colonizing species (means: 3.35 and 2.63, P = .03) . Although numbers were small, nurses with damaged hands were significantly more likely to be colonized with Staphylococcus hominis (P = .03) . Fifty-nine percent of S hominis isolates from nurses with damaged hands were resistant to methicillin compared with 27% of isolates from those with healthy skin (P = .14) . Twenty percent of nurses with damaged hands were colonized with Staphylococcus aureus compared with none of the nurses with normal hands (P = .11) . Nurses with damaged hands were also twice as likely to have gram-negative bacteria (P = .20), entercocci (P = .13), and Candida (P = .30) present on the hands . Antimicrobial resistance of the coagulase-negative staphylococcal flora (with the exception of S hominis) did not differ between the 2 groups, nor did a trend toward increasing resistance exist when compared with other studies during the past decade . Skin moisturizers and protectant products were used almost universally by nurses at work, primarily products brought from home . Efforts to improve hand condition are warranted because skin damage can change microbial flora . Such efforts should include assessment or monitoring of hand care practices, formal institutional policy adoption and control of use of skin protectant products or lotions, and prudent use of latex gloves or more widespread use of powder-free and nonlatex products.

Am J Infect Control, 1998 Oct, 26(5), 495 - 501
Effect of laundering on the barrier properties of reusable surgical gown fabrics; Leonas KK; BACKGROUND: Relationships between selected fabric characteristics and the barrier effectiveness of surgical gown fabrics to bacterial transmission were examined . The effect of laundering on these characteristics was determined . METHODS: Five commercially available reusable surgical gowns were evaluated in this study . Four of the gowns were produced from woven fabrics . One gown was produced from a 3-layer composite that contained a microporous membrane between a woven and knit fabric . By using standard test methods, the following characteristics were evaluated: thickness, weight, pore size, and oil and water repellency . Gowns were laundered 25 and 50 times by a commercial laundry service that specialized in cleaning surgical gowns . Gown fabrics were sterilized only before laboratory evaluation and not after each laundering cycle . Resistance of the fabrics to the transmission of microorganism suspensions under a hydrostatic pressure was determined . Staphylococcus aureus was the microorganism used in this study . CONCLUSIONS: A combination of several fabric characteristics were associated with the barrier properties of the surgical gown fabrics studied . Repellency and pore size contributed to gown performance . Laundering reduced the ability of the fabric to prevent the transmission of bacteria through the fabrics . Only 1 fabric showed no transmission of bacteria after laundering . This fabric retained the greatest degree of repellency and had the greatest thickness . Higher repellency ratings generally corresponded with higher barrier properties . Two fabrics showed no significant increase in the amount of bacteria that transmitted through the fabric after laundering . Both of these gowns were reinforced with a second fabric layer.

Rev Esp Quimioter, 1998 Sep, 11(3), 238 - 44
{Comparison of the in vitro and in vivo effects of meropenem and ciprofloxacin on the morphology of Escherichia coli and Staphylococcus aureus}; Martinez FF et al.; In the treatment of infections, subinhibitory concentrations are commonly present and induce a wide range of effects . Some of these effects have been reported to improve the efficacy of these compounds . One of these effects, the change of the bacterial morphology, was assayed in this study both in vitro and in vivo, and their results were compared . Two antimicrobial agents (meropenem and ciprofloxacin) and two standard Gram-positive and Gram-negative strains (S . aureus y E . coli) were used . The methods employed included the in vitro exposure of microorganisms on Mueller-Hinton agar plates, and the in vivo intraperitoneal infection model in mice . With all the sub-MICs tested, the in vitro results showed that meropenem induced the formation of round cells (spheroplasts) on E . coli, while ciprofloxacin produced filaments . With S . aureus, the two antimicrobial agents induced the formation of cellular aggregates (clusters) with a diameter greater than 1 mm . The in vivo results confirmed those observed in vitro, but to a lesser extent . These results agree with those expected in relation with the mechanisms of action of each drug, and could be important in order to prevent a lost in efficacy when the levels of the drug are below the MIC.

Eur J Pharm Sci, 1998 Oct, 6(4), 303 - 9
Synthesis and evaluation of lysozyme derivatives exhibiting an enhanced antimicrobial action; Bernkop-Schnurch A et al.; In order to generate novel preservatives exhibiting a broad antimicrobial spectrum against Gram-positive as well as Gram-negative bacteria, lysozyme was modified by the covalent attachment of caffeic acid and cinnamic acid, respectively . Linkage of these organic acids to lysozyme was achieved by the constitution of amide bindings between the carboxyl group of ligands and primary amino groups of the enzyme mediated by a carbodiimide . Compared to nonmodified lysozyme, the lytic activity of all resulting conjugates was reduced . In contrast, bacterial growth of Escherichia coli (ATCC 8739) could be strongly inhibited by lysozyme-caffeic acid conjugates and to a lower degree also by lysozyme-cinnamic acid conjugates . The minimal inhibitory concentration against E . coli was 0.05% for the lysozyme derivative of the highest antimicrobial activity . However, the efficacy of lysozyme derivatives against Staphylococcus aureus (ATCC 6538) was slightly reduced . As the antimicrobial spectrum of lysozyme altogether could be substantially widened, these derivatives represent promising candidates as novel preservatives for various pharmaceutical and cosmetic formulations.

Inflammation, 1998 Oct, 22(5), 493 - 507
Heparin binding protein (CAP37) is an opsonin for Staphylococcus aureus and increases phagocytosis in monocytes; Heinzelmann M et al.; Heparin binding protein (HBP), also known as cationic antibiotic protein (CAP37) or azurocidin, is stored in azurophilic granules of neutrophils and is released to the extracellular space when granulocytes phagocytose Staphylococcus aureus . We investigated whether extracellular HBP also has the potential to increase phagocytosis of S . aureus by other phagocytes . We used flow cytometry to characterize the binding of HBP to S . aureus and to simultaneously measure phagocytosis and superoxide production of opsonized S . aureus in monocytes and granulocytes . Our results demonstrate that HBP is a strong opsonin for S . aureus, and that monocytes, but not granulocytes, increase phagocytosis of HBP-treated S . aureus . However, HBP-treated S . aureus increases the production of superoxide in both monocytes and granulocytes as compared with untreated S . aureus . These findings support the role of granulocytes in the afferent limb of inflammation and demonstrate that HBP, when released from activated granulocytes, potentiates bacterial uptake in monocytes and enhances the potential of microbial killing in monocytes and granulocytes.

J Biol Chem, 1998 Nov 6, 273(45), 29847 - 56
Characterization of antibacterial COOH-terminal proenkephalin-A-derived peptides (PEAP) in infectious fluids . Importance of enkelytin, the antibacterial PEAP209-237 secreted by stimulated chromaffin cells; Goumon Y et al.; Proenkephalin-A (PEA) and its derived peptides (PEAP) have been described in neural, neuroendocrine tissues and immune cells . The processing of PEA has been extensively studied in the adrenal medulla chromaffin cell showing that maturation starts with the removal of the carboxyl-terminal PEAP209-239 . In 1995, our laboratory has shown that antibacterial activity is present within the intragranular chromaffin granule matrix and in the extracellular medium following exocytosis . More recently, we have identified an intragranular peptide, named enkelytin, corresponding to the bisphosphorylated PEAP209-237, that inhibits the growth of Micrococcus luteus (Goumon, Y., Strub, J . M., Moniatte, M., Nullans, G., Poteur, L., Hubert, P., Van Dorsselaer, A., Aunis, D., and Metz-Boutigue, M . H . (1996) Eur . J . Biochem . 235, 516-525) . As a continuation of this previous study, in order to characterize the biological function of antibacterial PEAP, we have here examined whether this COOH-terminal fragment is released from stimulated chromaffin cells and whether it could be detected in wound fluids and in polymorphonuclear secretions following cell stimulation . The antibacterial spectrum shows that enkelytin is active against several Gram-positive bacteria including Staphylococcus aureus, but it is unable to inhibit the Gram-negative bacteria growth . In order to relate the antibacterial activity of enkelytin with structural features, various synthetic enkelytin-derived peptides were tested . We also propose a computer model of synthetic PEAP209-237 deduced from 1H NMR analysis, in order to relate the antibacterial activity of enkelytin with the three-dimensional structure . Finally, we report the high phylogenetic conservation of the COOH-terminal PEAP, which implies some important biological function and we discuss the putative importance of enkelytin in the defensive processes.

Med Trop (Mars), 1998, 58(2), 155 - 7
{Methicillin-resistant Staphylococcus aureus in Dakar}; Sow AI et al.; This study was carried out at the Fann University Hospital Center in Dakar, Senegal between 1994 and 1996 . The purpose was to assess the prevalence of methicillin-resistant Staphylococcus aureus and to propose alternative treatments . A total of 149 stains of Staphylococcus aureus were isolated from a variety of clinical specimens . Sensitivity to various antibiotics was tested by the disc diffusion technique (anti-biogram) . Resistance to methicillin was evaluated by the oxacillin disc diffusion technique on Mueller-Hinton agar containing 5% NaCl . The prevalence of methicillin resistance was 66.4% . All strains of Staphylococcus aureus were sensitive to vancomycin . Other highly effective antibiotics included fucidic acid (94%), aminoglycosides (91%), cotrimoxazol (89.6%), and norfloxacin (84.5%) . Most strains (70.6%) presented a wide profile against macrolides and related groups . The LSa phenotype (resistance to lincosamines and streptogramines) was the predominant resistant phenotype . The results of this study indicate that the prevalence of methicillin-resistant Staphylococcus aureus is increasing in Senegal . Since these strains respond well to chloramphenicol and cotrimoxazole, clinicians are advised to use these drugs as an alternative first-line treatment.

Mol Microbiol, 1998 Oct, 30(2), 393 - 404
Staphylococcus aureus genetic loci impacting growth and survival in multiple infection environments; Coulter SN et al.; The Gram-positive bacterium Staphylococcus aureus infects diverse tissues and causes a wide spectrum of diseases, suggesting that it possesses a repertoire of distinct molecular mechanisms promoting bacterial survival in disparate in vivo environments . Signature-tag transposon mutagenesis screening of a 1520-member library identified numerous S . aureus genetic loci affecting growth and survival in four complementary animal infection models including mouse abscess, bacteraemia and wound and rabbit endocarditis . Of a total of 237 in vivo attenuated mutants identified by the murine models, less than 10% showed attenuation in all three models, emphasizing the advantage of screening in diverse disease environments . The largest gene class identified by these analyses encoded peptide and amino acid transporters, some of which were important for S . aureus survival in all animal infection models tested . The identification of staphylococcal loci affecting growth, persistence and virulence in multiple tissue environments provides insight into the complexities of human infection and on the molecular mechanisms that could be targeted by new antibacterial therapies.

Mol Microbiol, 1998 Oct, 30(2), 245 - 57
Clumping factor B (ClfB), a new surface-located fibrinogen-binding adhesin of Staphylococcus aureus; Ni Eidhin D et al.; The surface-located fibrinogen-binding protein (clumping factor; ClfA) of Staphylococcus aureus has an unusual dipeptide repeat linking the ligand binding domain to the wall-anchored region . Southern blotting experiments revealed several other loci in the S . aureus Newman genome that hybridized to a probe comprising DNA encoding the dipeptide repeat . One of these loci is analysed here . It also encodes a fibrinogen-binding protein, which we have called ClfB . The overall organization of ClfB is very similar to that of ClfA, and the proteins have considerable sequence identity in the signal sequence and wall attachment domains . However, the A regions are only 26% identical . Recombinant biotinylated ClfB protein bound to fibrinogen in Western ligand blots . ClfB reacted with the alpha- and beta-chains of fibrinogen in the ligand blots in contrast to ClfA, which binds exclusively to the gamma-chain . Analysis of proteins released from the cell wall of S . aureus Newman by Western immunoblotting using antibody raised against the recombinant A region of ClfB identified a 124 kDa protein as the clfB gene product . This protein was detectable only on cells that were grown to the early exponential phase . It was absent from cells from late exponential phase or stationary phase cultures . Using a clfB mutant isolated by allelic replacement alone and in combination with a clfA mutation, the ClfB protein was shown to promote (i) clumping of exponential-phase cells in a solution of fibrinogen, (ii) adherence of exponential-phase bacteria to immobilized fibrinogen in vitro, and (iii) bacterial adherence to ex vivo human haemodialysis tubing, suggesting that it could contribute to the pathogenicity of biomaterial-related infections . However, in wild-type exponential-phase S . aureus Newman cultures, ClfB activity was masked by the ClfA protein, and it did not contribute at all to interactions of cells from stationary-phase cultures with fibrinogen . ClfB-dependent bacterial adherence to immobilized fibrinogen was inhibited by millimolar concentrations of Ca2+ and Mn2+, which indicates that, like ClfA, ligand binding by ClfB is regulated by a low-affinity inhibitory cation binding site.

What Is Anthrax?, What Is Bioengineering?, What Is Nitrification?, What Is Rhizobia?, What Is Botulism?, s, Microorganisms, s, Microbiology, s, Bacteriology, e, Microorganism, s, Microbes, s, Yeasts, c, Pasteurella, n, Escherichia coli, a, Campylobacter, n, S. cerevisiae, c, Bacteria, r, Antimicrobials, n, Erythromycin, r, Microorganism, s, Microorganisms, s, Bacillus, n, Microorganisms, o, Yeasts, a, Klebsiella, s, Petri dish, o, Escherichia coli, s, Escherichia coli, n, Listeriosis, e, S. cerevisiae, c, Bacillus, s, Bacteriological

Scientific Publications - Work Done by Microbiology Reader Bioscreen C
Agricultural Microbiology Anaerobic Microbiology Antimicrobial Susceptibility Artificial Atmosphere Bioassay of Antibiotics Biofilm Microbiology Bioreactor Technology Biotechnology Cell Biology Clinical Microbiology Environmental Microbiology Experiments with Yeast	Fermentation Food Microbiology Functional Genomics Gene Technology Growth Media Development Growth Rate and Lag Time Industrial Microbiology Medical/Pharmaceutical Field Microbiological Assay Microbiological Research Microbiology of Cosmetics go to a specific theme...	Military Microbiology Molecular Microbiology Mutagenicity and Genotoxicity Oral Microbiology Patents Postantibiotic Studies Soil Microbiology Spore Microbiology Veterinary Microbiology Waste/Wastewater Treatment Water Microbiology Wine Microbiology

� 2005 Transgalactic Ltd (manufacturer of Bioscreen C software) | Privacy Statement | P.O. Box 1393, 00101 Helsinki, Finland, phone: +358 9 85172920, fax: +358 9 8749481, e-mail: microbiology@bionewsonline.com

Last modified: May 25, 2005