Staphylococcus aureus

J Biol Chem, 1999 Jul 2, 274(27), 18942 - 6
Inactivated pbp4 in highly glycopeptide-resistant laboratory mutants of Staphylococcus aureus; Sieradzki K et al.; Both vancomycin- and teicoplanin-resistant laboratory mutants of Staphylococcus aureus produce peptidoglycans of altered composition in which the proportion of highly cross-linked muropeptide species is drastically reduced with a parallel increase in the representation of muropeptide monomers and dimers (Sieradzki, K., and Tomasz, A . (1997) J . Bacteriol . 179, 2557-2566; and Sieradzki, K . , and Tomasz, A . (1998) Microb . Drug Resist . 4, 159-168) . We now report that the distorted peptidoglycan composition is related to defects in penicillin-binding protein 4 (PBP4); no PBP4 was detectable by the fluorographic assay in membrane preparations from the mutants, and comparison of the sequence of pbp4 amplified from the mutants indicated disruption of the gene by two types of abnormalities, a 17-amino acid long duplication starting at position 305 of the pbp4 gene was detected in the vancomycin-resistant mutant, and a stop codon was found to be introduced into the pbp4 KTG motif at position 261 in the mutant selected for teicoplanin resistance . Additional common patterns of disturbances in the peptidoglycan metabolism of the mutants are indicated by the increased sensitivity of mutant cell walls to the M1 muramidase and decreased sensitivity to lysostaphin, which is a reversal of the susceptibility pattern of the parental cell walls . Furthermore, the results of high performance liquid chromatography analysis of lysostaphin digests of peptidoglycan suggest an increase in the average chain length of the glycan strands in the peptidoglycan of the glycopeptide-resistant mutants . The increased molar proportion of muropeptide monomers in the cell wall of the glycopeptide-resistant mutants should provide binding sites for the "capture" of vancomycin and teicoplanin molecules, which may be part of the mechanism of glycopeptide resistance in S . aureus.

J Antimicrob Chemother, 1999 May, 43(5), 737 - 40
Efficacy and pharmacodynamics of teicoplanin given daily during the first 3 days and then on alternate days for methicillin-resistant Staphylococcus aureus infections; Bantar C et al.; Fifteen evaluable patients (mean age, 67 years) were enrolled to assess the efficacy of teicoplanin, 6 mg/kg given daily during the first 3 days and then on alternate days, for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections . Eight patients had soft tissue infections, four catheter-associated bacteraemia, two osteomyelitis and one pneumonia . Clinical cure was observed in 13 of 15 patients . Both clinical and bacteriological failures were shown in the two patients with osteomyelitis . The mean serum levels of teicoplanin (mg/L) were 22, 8 and 6.7 for peak, 24 h and 48 h troughs, respectively . The dosage employed in this study proved effective in non-deep-seated MRSA infections.

J Antimicrob Chemother, 1999 May, 43(5), 729 - 31
Reduced susceptibility to vancomycin of nosocomial isolates of methicillin-resistant Staphylococcus aureus; Kantzanou M et al.; The MICs of vancomycin for 56 random nosocomial Staphylococcus aureus isolates homogeneously resistant to methicillin (homMRSA), 16 heterogeneously resistant isolates (hetMRSA) and 25 susceptible isolates (MSSA) were determined by a standard broth microdilution method . Representative isolates were also tested by an agar incorporation method, the Etest and population analysis . Although always in the susceptible range, MICs of vancomycin for homMRSA were significantly higher than those for hetMRSA or MSSA . Moreover, a homMRSA strain belonging to one of the major Greek MRSA clones contained a sub-population of cells that could grow in the presence of vancomycin 8 mg/L at a frequency of 6.7 x 10(-8).

J Antimicrob Chemother, 1999 May, 43 Suppl B, 31 - 7
The effect of moxifloxacin on its target topoisomerases from Escherichia coli and Staphylococcus aureus; Schedletzky H et al.; The effect of moxifloxacin on its target enzymes was evaluated by three different approaches: (i) the MICs of moxifloxacin and nine other fluoroquinolones were determined for mutants of Escherichia coli (n = 13) and Staphylococcus aureus (n = 5) carrying different combinations of resistance mutations; (ii) the activity of moxifloxacin on isolated targets was determined as IC50 values for wild-type and mutant type II topoisomerases from E . coli; and (iii) the mutation frequencies were determined for two single-step mutants (MI with a Ser83-->Leu mutation in gyrA and WT-4 with a Ser80-->Ile mutation in parC) and their parent strain (WT) . Of the quinolones tested, moxifloxacin was the only one showing an equivalent high activity against both targets . This is reflected by a comparable high susceptibility of the test strains of E . coli and S . aureus and by the IC50 values of moxifloxacin which were 50-90% lower than those of ciprofloxacin, norfloxacin and sparfloxacin for the wild-type and single mutant enzymes of gyrase and topoisomerase IV . However, double mutant GyrA was significantly more sensitive to moxifloxacin than to the other fluoroquinolones tested, while wild-type topoisomerase IV was two-fold more refractory . Mutation rates of WT, MI and WT-4 for ciprofloxacin and moxifloxacin were 5 x 10(-8) vs 4 x 10(-10); <6 x 10(-11) vs <6 x 10(-11); and 2 x 10(-6) vs 5 x 10(-7), respectively . These data indicate an equivalent high inhibitory activity of moxifloxacin on DNA gyrase and topoisomerase IV of E . coli.

J Food Prot, 1999 Jun, 62(6), 644 - 9
Bacterial contamination of ready-to-eat foods and fresh products in retail shops and food factories; Kaneko KI et al.; Raw vegetables cut for salad, cooked salad, cooked rice, boiled noodles, bean curd, and cooked Japanese foods were purchased in 27 retail shops in Tokyo . Intact vegetables before being processed and ready-to-eat fresh salad products were obtained from two food factories located in the suburbs of Tokyo . Two hundred thirty-eight retail samples, 137 samples of intact vegetables, and 159 samples of fresh products were examined for aerobic plate count (APC), coliforms, Escherichia coli, Listeria spp., Staphylococcus aureus, and Bacillus cereus . The APC of retail foods were 2.1 to 5.7 log CFU/g, and the range for the coliforms was 0.1 to 2.3 log CFU/g . The APC and coliform values showed that the raw vegetables cut for salad were the most heavily contaminated among the six kinds of ready-to-eat foods examined . Although L . monocytogenes was not detected, two samples of raw vegetables and five kinds of cooked foods yielded Listeria spp . S . aureus was detected in one sample of Japanese cooked food . The APC of the intact vegetables were 2.9 to 7.3 log CFU/g upon arrival and 2.2 to 7.2 log CFU/g after 3 days storage at 10 degrees C . The APC of the fresh products were 3.4 to 7.6 log CFU/g upon arrival and 4.7 to 8.7 log CFU/g after 3 days storage at 10 degrees C . The isolation rates for coliforms were 6.1 to 50% for intact vegetables and 50 to 66.7% for fresh products . E . coli was detected only in the fresh products . B . cereus was isolated from 20.1% (17 of 81) of the intact vegetables and 9.2% (8 of 87) of the fresh products.

J Biomol NMR, 1999 May, 14(1), 85 - 8
{13C}-constant-time {15N,1H}-TROSY-HNCA for sequential assignments of large proteins; Salzmann M et al.; The greatly improved sensitivity resulting from the use of TROSY during 15N evolution and amide proton acquisition enables the recording of HNCA spectra of large proteins with constant-time 13C alpha evolution . In {13C}-ct-{15N,1H}-TROSY-HNCA experiments with a 2H/13C/15N-labeled 110 kDa protein, 7,8-dihydroneopterin aldolase from Staphylococcus aureus, nearly all correlation peaks seen in the {15N,1H}-TROSY-HNCA spectrum were also detected . The improved resolution in the 13C dimension then enabled a significant number of sequential assignments that could not be obtained with {15N,1H}-TROSY-HNCA without {13C}-constant-time period.

Pediatr Radiol, 1999 May, 29(5), 367 - 71
MRI evaluation of infectious and non-infectious synovitis: preliminary studies in a rabbit model; Strouse PJ et al.; BACKGROUND: Literature on magnetic resonance imaging (MR) evaluation of inflammatory joint effusions is sparse . OBJECTIVE: To describe an animal model for studying infectious and non-infectious joint effusions with magnetic resonance imaging . MATERIALS AND METHODS: Ten rabbit knees with septic arthritis and four with talc synovitis were imaged with MR . Contralateral knees injected with saline served as controls . Fat saturation T2-weighted and gadolinium-enhanced T1-weighted images were assessed for joint effusion, and periarticular and adjacent intraosseous increased signal or enhancement . Each knee was cultured and underwent pathologic examination . RESULTS: Both Staphylococcus aureus and talc produced effusions in all knees . The degree of periarticular signal and enhancement was greater in infected knees than talc-injected knees . No abnormal enhancement was seen within bone . Pathologic examination showed a greater degree of inflammation and joint destruction in the infected knees, but no evidence of osteomyelitis . CONCLUSION: A greater degree of abnormal signal and enhancement seen on MR suggests a more vigorous inflammatory process, as seen with septic arthritis . In spite of advanced septic arthritis, no enhancement was evident within bone, suggesting that enhancement within bone is not an expected finding in isolated septic arthritis and should raise concern for osteomyelitis.

Biochem Biophys Res Commun, 1999 Jun 24, 260(1), 111 - 6
Functional mimicry of protein A of Staphylococcus aureus by a proteolytically cleaved fragment; Sinha P et al.; Protein A (PA) of Staphylococcus aureus has an array of biological functions, such as antitumor, antitoxic, anticarcinogenic, immunomodulatory, antifungal, and antiparasitic properties . We have already established that a theoretical trypsin-digested peptide fragment of protein A (20-mer) mimics immunomodulatory and IgG binding property of PA . In the present report we have concentrated on a 16-mer chymotryptic fragment of protein A, which has a sequence of 13 amino acids in common with the previously studied 20-mer peptide . Molecular modeling study qualitatively predicted that both 20-mer and 16-mer peptides retain Fc binding ability from an interaction energy point of view . In the present study our aim was to understand whether this theoretically predicted 16-mer chymotryptic fragment could be formed in a real experiment and also to understand its biological activities . Chymotrypsin cleavage of PA at 37 degrees C for 24 h produced four major fragments on reverse-phase HPLC . The amino acid analyses of each fragment show the absence of cysteine residue from all fragments, which justifies the absence of cysteine in PA . We also observed high content of aspartic acid and glutamic acid residues in all fragments . On gel-filtration chromatography the chymotrypsin cleavage of PA shows five peaks, one of which overlaps with our theoretically selected 16-mer peptide on superimposition . We verified the IgG binding capacity of 16-mer peptide by capillary electrophoresis . The 16-mer peptide also induces the production of TNFalpha and IL-1alpha in serum of mice . The above observations suggest that the 16-mer peptide may be produced by chymotrypsin cleavage and also that this peptide possesses some of the major biological properties of PA, such as IgG binding, TNFalpha and IL-1alpha elicitation, etc .

Biochem Biophys Res Commun, 1999 Jun 24, 260(1), 105 - 10
Induction of cell proliferation and apoptosis: dependence on the dose of the inducer; Das T et al.; Protein A (PA) of Staphylococcus aureus is known as an immunomodulator . In a search of the molecular mechanism(s) of PA-induced immunocyte potentiation, we found dose-dependent binding of PA (0.01 to 100 microg/ml PA) to the mice splenic lymphocytes . Interestingly, treatment of 1 microg PA/20 g mice increased the splenic lymphocyte number approximately 5-fold over control but at a 10-microg dose the cell number was decreased compared with a 1-microg dose . Flow cytometric analysis of cell-cycle phase distribution of nuclear DNA in splenic lymphocytes showed that at a 1-microg dose, PA shifted the cell-cycle phases from G0/G1 to S and G2/M supporting the pro-proliferative role of PA . In contrast, the same inducer increased the sub-G1 cell population at a 10-microg dose indicating the breakdown of cellular DNA . These findings were supported by DNA ladder formation and nuclear breakdown at this higher dose . Further studies revealed that at a 1-microg dose, the level of the pro-proliferative/anti-apoptotic protein bcl-2 was increased in splenic lymphocytes whereas at a 10-microg dose it showed a decreasing trend . In contrast, concentrations of proapoptotic proteins, p53 and bax, were increased at a 10-microg dose . A search of the mechanism(s) of such differential action of PA at these two doses revealed that the lower dose of PA upregulated the production of interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) to the extent which has already been reported by our laboratory to be beneficial to the host . However, at a larger dose, much higher release of TNF-alpha and interleukin-2 (IL-2) may account for the apoptosis of splenic cells . All these findings indicated that the cross-talk between all these pro- and anti-apoptotic factors may contribute to maintain a balance between growth and death of cells and may be one of the important factors deciding whether a cell would follow a proliferative pathway or an apoptotic pathway .

Scand J Infect Dis, 1999, 31(1), 98 - 100
Primary sternal osteomyelitis and septicaemia due to Staphylococcus aureus; Mofredj A et al.; Primary sternal osteomyelitis is rare in these recent decades . Only scattered cases have been reported, most of them in intravenous drug users . We report the case of an 88-y-old woman who presented a primary sternal infection due to Staphylococcus aureus associated with secondary septicaemia . The only predisposing factor was radiotherapy for a malignant tumour of the right mammary gland 20 y ago . Diagnostic evaluation and therapeutic management are briefly discussed.

J Antimicrob Chemother, 1999 Jan, 43(1), 113 - 8
The clinical efficacy of continuous-infusion flucloxacillin in serious staphylococcal sepsis; Leder K et al.; Since the efficacy of beta-lactams against pathogens such as methicillin-susceptible Staphylococcus aureus (MSSA) is related to the time for which serum drug concentrations exceed the MIC for the pathogen, administration of anti-staphylococcal beta-lactams by continuous infusion may provide a more suitable means of drug delivery than intermittent dosing . To assess the clinical efficacy of continuous-infusion therapy, we reviewed the outcomes for 20 consecutive patients with proven serious MSSA sepsis (three with endocarditis, ten osteomyelitis, one endocarditis plus osteomyelitis and six deep abscess) treated with continuous-infusion flucloxacillin (8-12 g/day) . Patients initially receiving routine intermittent-dose flucloxacillin therapy were changed to continuous-infusion flucloxacillin (mean duration 29 days; range 4-60 days) for completion of their treatment course . In the majority of cases this was given at home . Serum flucloxacillin concentrations during continuous-infusion flucloxacillin 12 g/day were 11.5->40 mg/L (ten patients) and those during continuous-infusion flucloxacillin 8 g/day were 8->40 mg/L (five patients), these concentrations being well above the expected MIC of flucloxacillin for MSSA . Continuous-infusion flucloxacillin was well tolerated by most patients, and 14/17 patients (82%) who completed their course of continuous-infusion flucloxacillin were judged clinically and microbiologically cured at long-term follow-up (mean 67 weeks; range 4-152 weeks) . These preliminary data suggest that, following initial intermittent-dose flucloxacillin therapy, continuous-infusion flucloxacillin is an effective treatment option for serious MSSA sepsis, and forms a feasible and possibly preferable alternative to glycopeptides when considering home-based parenteral therapy for these infections . Further studies are needed to identify whether continuous-infusion flucloxacillin can entirely replace intermittent-dose therapy for such infections.

J Antimicrob Chemother, 1999 Jan, 43(1), 105 - 12
Cost-effectiveness of prophylactic nasal mupirocin in patients undergoing peritoneal dialysis based on a randomized, placebo-controlled trial; Davey P et al.; The study objective was to measure the benefits of elimination of nasal carriage of Staphylococcus aureus by calcium mupirocin ointment in patients undergoing continuous ambulatory peritoneal dialysis . The design was a prospective, placebo-controlled, randomized clinical trial . The subjects were 267 patients recruited from nine renal units in Belgium, France and the UK . The main outcome measures were the rate of catheter exit site infection (ESI), rates of other infections and healthcare costs from the perspective of a hospital budget-holder . The rate of ESI caused by S . aureus was significantly reduced from one in 28.1 patient months to one in 99.3 patient months (P = 0.006) and there were also non-significant trends towards lower rates of ESI caused by any organism and peritonitis caused by S . aureus . In comparison with the placebo group, patients in the mupirocin group with ESI had lower antibiotic (P = 0.02) and hospitalization costs (P = 0.065) . However, overall costs of antibiotic treatment, for all infections combined, were not significantly different (P = 0.2) and total antibiotic costs (including mupirocin) were significantly higher in the mupirocin group (P = 0.001) . Mupirocin prophylaxis would have been cost-neutral if the rate of ESI increased to >75% in the placebo group, or if all healthcare costs increased by 40%, or if the cost of screening was reduced from Pound Sterling 15 to Pound Sterling 3 per patient, or if the cost of mupirocin treatment was reduced from Pound Sterling 93 to Pound Sterling 40 per patient year . In conclusion, savings in healthcare costs are unlikely to be sufficiently great to offset the cost of mupirocin and screening for nasal carriage of S . aureus . The decision about whether or not to implement mupirocin should depend on a local analysis of the value of preventing ESIs caused by S . aureus.

Biosci Biotechnol Biochem, 1999 May, 63(5), 884 - 91
Assembly of Staphylococcus aureus leukocidin into a pore-forming ring-shaped oligomer on human polymorphonuclear leukocytes and rabbit erythrocytes; Sugawara N et al.; Staphylococcal leukocidin consists of two separate proteins, LukS and LukF, which cooperatively lyse human and rabbit polymorphonuclear leukocytes and rabbit erythrocytes . Here we studied the pore-forming properties of leukocidin and the molecular architecture of the leukocidin pore . (1) Leukocidin caused an efflux of potassium ions from rabbit erythrocytes and swelling of the cells before hemolysis . However, ultimate lysis of the toxin-treated swollen erythrocytes did not occur when polyethylene glycols with hydrodynamic diameters of > or = 2.1 nm were present in the extracellular space . (2) Electron microscopy showed the presence of a ring-shaped structure with outer and inner diameters of 9 and 3 nm, respectively, on leukocidin-treated human polymorphonuclear leukocytes and rabbit erythrocytes . (3) Ring-shaped structures of the same dimensions were isolated from the target cells, and they contained LukS and LukF in a molar ratio of 1:1 . (4) A single ring-shaped toxin complex had a molecular size of 205 kDa . These results indicated that LukS and LukF assemble into a ring-shaped oligomer of approximately 200 kDa on the target cells, forming a membrane pore with a functional diameter of approximately 2 nm.

Retina, 1999, 19(3), 223 - 9
Experimental prophylaxis of Staphylococcus aureus endophthalmitis after vitrectomy: the use of antibiotics in irrigating solution; Liang C et al.; PURPOSE: To test the efficacy of clindamycin and gentamicin in irrigating solution during vitrectomy to prevent experimental Staphylococcus aureus endophthalmitis . MATERIALS AND METHODS: Thirty-six New Zealand white rabbits were divided into six groups . Vitrectomy using two different irrigating solutions was followed by intravitreal injection of S . aureus: Group 1, balanced salt solution (BSS) followed by 1,000 colony-forming units (CFU) S . aureus; Group 2, BSS fortified with clindamycin, 10 microg/mL, and gentamicin, 8 microg/mL (CGBSS), followed by intravitreal injection of 1,000 CFU S . aureus; Group 3, BSS followed by 2,000 CFU S . aureus; Group 4, CGBSS followed by 2,000 CFU S . aureus; Group 5, BSS followed by 4,000 CFU S . aureus; and Group 6, CGBSS followed by 4,000 CFU S . aureus . The eyes were examined clinically after surgery . Vitreous samples were cultured and histologic studies were performed . RESULTS: Severe endophthalmitis developed in all eyes in Groups 1, 3, and 5 (not given antibiotics) . No endophthalmitis developed in Group 2 . In Group 4, five of the six eyes were normal and one eye had endophthalmitis . In Group 6, one eye had clear vitreous and fundus, three eyes had moderate vitreous haze, and the other four eyes demonstrated severe endophthalmitis . Bacterial growth in Groups 1, 2, 3, 4, 5, and 6 were 4/4, 0/4, 6/6, 1/6, 4/6, and 2/8 eyes, respectively . CONCLUSION: When 1,000 to 2,000 CFU S . aureus were injected after vitrectomy, clindamycin and gentamicin in the irrigating solution significantly diminished the intraocular inflammation and the rate of positive bacterial culture . Clindamycin and gentamicin in the irrigating solution were not significantly effective when 4,000 CFU bacteria was injected; however, the degree of inflammation was less severe than in the control group.

Retina, 1999, 19(3), 218 - 22
Penetration of topical and oral ciprofloxacin into the aqueous and vitreous humor in inflamed eyes; Ozturk F et al.; PURPOSE: To assess the aqueous and vitreous penetration of ciprofloxacin after topical and combined topical and oral administration and investigate the effects of inflammation on drug penetration . METHODS: A standardized penetrating injury was made in the right eyes of 16 rabbits . Intraocular inflammation was induced by intravitreal injection of a suspension of Staphylococcus aureus in these eyes . The animals were divided into two groups according to treatment methodology: topical and topical-oral . The intact left eyes of the animals were maintained as controls . In the topical treatment group, two drops of ciprofloxacin 0.3% were instilled to both eyes every 30 minutes for 4 hours . In the topical-oral treatment group, animals were given two oral 40 mg/kg doses of ciprofloxacin at 12-hour intervals . After the last oral dose, the protocol of the topical group was applied to these eyes . Half an hour after the last drop, 100-microL samples were taken from aqueous and vitreous humor of all eyes . Drug concentrations were measured using high-pressure liquid chromatography . RESULTS: Mean aqueous levels of ciprofloxacin in control eyes were 2.31 microg/mL (range, 1.02-6.27 microg/mL) in the topical group and 5.88 microg/mL (1.52-17.81) in the topical-oral group . Mean aqueous levels in inflamed eyes were 7.36 microg/mL (2.34-17.15) in the topical group and 14.43 microg/mL (2.18-18.66) in the topical-oral group . Mean vitreous levels in control eyes were 0.77 microg/mL (0.09-1.93) in the topical group and 1.01 microg/mL (0.49-1.57) in the topical-oral group . Mean vitreous levels in inflamed eyes were 0.95 microg/mL (0.18-1.27) in the topical group and 1.98 microg/mL (0.51-3.34) in the topical-oral group . There was no significant difference among the groups (P > 0.05) . Mean aqueous levels in all eyes and mean vitreous levels in the combined topical and oral group of inflamed eyes were above the 90% minimum inhibitory concentration for most of the common microorganisms causing endophthalmitis . CONCLUSION: There is an increase in both aqueous and vitreous humor concentrations with inflammation and with oral and topical administrations, as opposed to topical only, of ciprofloxacin . Using oral as well as topical treatment may be a beneficial method of antibiotic prophylaxis in ocular trauma once a patient has received intravenous or intravitreal therapy.

J Vet Med Sci, 1999 May, 61(5), 569 - 71
Effect of vitamin B2 on somatic cell counts in milk of clinical Staphylococcus aureus mastitis; Sato S et al.; Effects of intravenous injection of Vitamin B2 (VB2) on the nitroblue tetrazolium (NBT) reductivity of peripheral blood neutrophils and the somatic cell counts (SCC) in quarter milk of Staphylococcus aureus mastitis were investigated . The NBT reductivities of neutrophils were enhanced at 2 days after single injection of VB2 (5.0 and 2.5 mg/kg), and were also enhanced at 4 days after initial injection of continuous 3 days of VB2 (2.5 mg/kg) . The SCC in quarter milk were significantly decreased at 3, 7 and 14 days after initial injection of continuous 3 days of VB2 (2.5 mg/kg), however, S . aureus in the infected quarter was not cured bacteriologically by VB2 injection.

Mayo Clin Proc, 1999 Jun, 74(6), 553 - 8
Staphylococcus aureus prosthetic joint infection treated with prosthesis removal and delayed reimplantation arthroplasty; Brandt CM et al.; OBJECTIVE: To estimate in patients with Staphylococcus aureus prosthetic joint infection after total hip arthroplasty (THA) or total knee arthroplasty (TKA) the microorganism-specific cumulative probability of treatment failure after prosthesis removal and delayed reimplantation arthroplasty . PATIENTS AND METHODS: All patients with S aureus THA or TKA infection, according to a strict case definition, who were treated with prosthesis removal and delayed reimplantation arthroplasty at Mayo Clinic Rochester between 1980 and 1991 were identified . The study group comprised patients who were free of infection at the time of reimplantation arthroplasty . This cohort was followed up until treatment failure, infection with another organism, prosthesis removal, death, or loss to follow-up occurred . The Kaplan-Meier survival method was used to estimate the cumulative probability of treatment failure . RESULTS: Among 120 S aureus prosthetic joint infections treated with prosthesis removal during the study period, 38 episodes (22 THA, 16 TKA) in 36 patients met the study inclusion criteria . After a median of 7.4 years (range, 0.9 year-16.4 years) of follow-up, treatment failure occurred in 1 (2.6%) of 38 episodes 1.4 years after reimplantation arthroplasty . The 5-year cumulative probability of treatment failure was 2.8% (95% confidence interval, 0%-8.2%) . CONCLUSIONS: These data suggest that prosthesis removal and delayed reimplantation arthroplasty is an effective treatment to limit the recurrence of S aureus prosthetic joint infection, provided there is no evidence of infection at the time of reimplantation arthroplasty.

J Orthop Res, 1999 May, 17(3), 382 - 91
Experimental acute hematogenous osteomyelitis in mice . II . Influence of Staphylococcus aureus infection on T-cell immunity; Yoon KS et al.; A murine model of acute hematogenous osteomyelitis was used to study the immune response following Staphylococcus aureus infection and to examine the hypothesis that the bacteria may modify T-cell responses due to the production of bacterial enterotoxins with mitogenic or superantigenic activity . Lymph-node T cell-receptor expression was assessed with use of flow cytometry and reverse transcription-polymerase chain reaction techniques, and increased apoptosis (programmed cell death) in T-cell subsets was monitored . The expression and levels of circulating cytokines and T-cell cytokines within tissues surrounding the damaged area of the proximal tibia were also investigated . Analysis of T-cell receptors in experimental osteomyelitis revealed two distinct patterns of T-cell evolution during the disease . Certain T-cell subsets (Vbeta2, Vbeta3, Vbeta9, and Vbeta10) were activated and expanded during the first 24 hours after infection; they reached maximum levels 6 days after infection, followed by a return to pre-infection levels . In contrast, other T-cell subsets (Vbeta11, Vbeta12, Vbeta13, Vbeta14, and Vbeta16) contracted during the first 24 hours after infection, followed by expansion to a maximum level 9 days after infection . Activation and proliferation of T-cell subsets (notably Vbeta14 T cells) was followed by apoptosis, suggesting that staphylococcal bone infection caused superantigenic-like effects on the mouse immune system . Analysis of cytokine responses in local tissue revealed that the T-cell cytokines interleukin-2 and interferon-gamma showed a late and relatively short activation pattern compared with the inflammatory cytokines interleukin-1, interleukin-6, and tumor necrosis factor-alpha . The results suggest that Staphylococcus aureus bone infection may undermine the antibacterial immune response through downregulation of T-cell immunity and immune-cytokine production, which could increase the severity of the systemic infection and local osseous destruction that occur with acute hematogenous osteomyelitis.

AORN J, 1999 Jun, 69(6), 1169 - 72, 1175-7, 1179 passim
Airborne particulates in the OR environment; Edmiston CE Jr et al.; Intraoperative sampling of airborne particulates is rarely performed in the OR environment because of technical difficulties associated with sampling methodologies and because of the common belief that airborne contamination is infrequently associated with surgical site infections (SSIs) . In this study, investigators recovered non-viable (i.e., lint) and viable (i.e., microorganisms) particulates during vascular surgery using a personal cascade impactor sampling device . The predominant nonviable particulates recovered during intraoperative sampling were wood pulp fibers from disposable gowns and drapes . Several potential nosocomial pathogens (e.g., Staphylococcus aureus, Staphylococcus epidermidis) and other drug-resistant isolates frequently were recovered from an area adjacent to the surgical field . The widespread presence of airborne particulates during surgery suggests that further studies are warranted to assess the role these particles may play in the development of SSIs or in dissemination of nosocomial pathogens within the OR and hospital environment.

Infect Immun, 1999 Jul, 67(7), 3667 - 9
Isolation and characterization of a sigB deletion mutant of Staphylococcus aureus; Nicholas RO et al.; The sigB gene of Staphylococcus aureus, coding for the alternate sigma factor B, has been deleted by allelic replacement mutagenesis . The mutant grew as well as the parent in vitro, although it was deficient in clumping factor, coagulase, and pigment . In two murine and one rat infection model the mutant showed no reduction in virulence.

Infect Immun, 1999 Jul, 67(7), 3267 - 75
Innate antimicrobial activity of nasal secretions; Cole AM et al.; Minimally manipulated nasal secretions, an accessible form of airway surface fluid, were tested against indigenous and added bacteria by using CFU assays . Antimicrobial activity was found to vary between donors and with different target bacteria and was markedly diminished by dilution of the airway secretions . Donor-to-donor differences in electrophoresis patterns of nasal secretions in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (PAGE) and acid urea-PAGE analyses were readily observed, suggesting that polymorphic genes encode the secreted proteins . Three donors (of twenty-four total), whose nasal fluid yielded similar protein band patterns and did not kill indigenous bacteria, were determined to be heavy nasal carriers of Staphylococcus aureus . Their fluid was deficient in microbicidal activity toward a colonizing strain of S . aureus but the defect was corrected in vitro by a 1:1 addition of nasal fluid from noncarriers . The microbicidal activity of normal fluid was inactivated by heating it for 10 min to 100 degrees C and could not be restored solely by the addition of two major nasal antimicrobial proteins, lysozyme and lactoferrin . Several other known antimicrobial proteins and peptides, including statherin, secretory phospholipase A2, and defensins, were identified in nasal secretions and likely contribute to their total antimicrobial properties . Nasal fluid may serve as a useful model for the analysis of lower-airway secretions and their role in host defense against airway colonization and pulmonary infections.

Infect Immun, 1999 Jul, 67(7), 3215 - 20
Moesin functions as a lipopolysaccharide receptor on human monocytes; Tohme ZN et al.; Bacterial endotoxin (lipopolysaccharide {LPS}), a glycolipid found in the outer membranes of gram-negative bacteria, induces the secretion of proinflammatory cytokines such as tumor necrosis factor alpha (TNF-alpha), interleukin-1 (IL-1), and IL-6 by monocytes/macrophages . The secretion of these biologically active compounds leads to multiple pathological conditions, such as septic shock . There is substantial evidence that chronic exposure to LPS mediates, at least in part, the tissue destruction associated with gram-negative infection . CD14, a 55-kDa protein, has been identified as an LPS receptor . In conjunction with a serum protein, LPS binding protein (LBP), LPS-CD14 interactions mediate many LPS functions in the inflammatory response . However, CD14 lacks a cytoplasmic domain, or any known signal transduction sequence motif, suggesting the existence of another cell surface domain capable of transducing signals . In this paper, we report a second, CD14-independent LPS binding site, which, based on biological activity, appears to be a functional LPS receptor . Cross-linking experiments were performed to identify LPS binding sites . Two molecules were identified: a 55-kDa protein (CD14) and a second, 78-kDa band . Sequencing of the 78-kDa protein by mass spectroscopic analysis revealed 100% homology with moesin (membrane-organizing extension spike protein) . Antibody to CD14 induced partial blocking of the LPS response . However, antimoesin monoclonal antibody completely blocked the LPS-induced TNF-alpha response in human monocytes, without blocking CD14 binding of LPS . Irrelevant isotype controls had no effect . Additional experiments were performed to evaluate the specificity of the antimoesin blocking . Separate experiments evaluated antimoesin effects on monocyte chemotaxis, IL-1 production in response to IL-1 stimulation, and TNF-alpha secretion in response to Staphylococcus aureus stimulation . Antimoesin blocked only LPS-mediated events . The data suggest that moesin functions as an independent LPS receptor on human monocytes . The role of moesin in transduction of CD14-mediated signals is discussed.

Res Microbiol, 1999 May, 150(4), 287 - 90
HSa of Staphylococcus aureus, a new member of the HU family of bacterial histone-like proteins; Viter S et al.; Histone-like proteins of the HU family are small, sequence-independent DNA binding proteins that facilitate a variety of DNA transactions . Here we report isolation from cell-free extracts of Staphylococcus aureus of HSa, a new member of the HU family . The NH2-terminal amino acid sequence of HSa led to identification of the corresponding gene (hsa) using the genome sequence of S . aureus . HSa is 90 amino acids long (Mr = 9 620) and shares 64 to 80% identity with homologs found in the genus Bacillus.

West Indian Med J, 1999 Mar, 48(1), 20 - 2
Methicillin resistant Staphylococcus aureus; Swanston WH; The prevalence of methicillin resistant Staphylococcus aureus (MRSA) at the General Hospital, Port-of-Spain, between June 1995 and May 1996 was determined . The MRSA prevalence rate was 4.6% of all S aureus isolates, with all but one nosocomially acquired . 15 isolates were associated with infections, and three were colonizing strains . 17 of the 18 patients with MRSA had received antibiotics previously, including 13 who had received multiple antibiotics . Skin and soft tissue were the sites of infection and colonization in 12 cases; and surgical wards and the Intensive Care Unit (ICU) accounted for 16 MRSA isolates . All isolates were sensitive to vancomycin and all but one were resistant to gentamicin . MRSA occurred sporadically in a wide distribution of wards and physicians' services, although the isolation of three strains from the ICU and three strains from a surgical ward were temporally related . Only one of two deaths was attributable to MRSA . Control of the spread of MRSA in this hospital must include the reinforcement of the appropriate use of antibiotics, hand washing and appropriate isolation of patients in the surgical and intensive care wards.

Biol Pharm Bull, 1999 May, 22(5), 463 - 70
Inhibitory effect of polyoxotungstates on the production of penicillin-binding proteins and beta-lactamase against methicillin-resistant Staphylococcus aureus; Fukuda N et al.; In our continuous work on the enhancement of the antibacterial activity of beta-lactam antibiotics against the cells of methicillin-resistant Staphylococcus aureus (MRSA) strains by Keggin-structural polyoxotungstates and their lacunary species, Wells-Dawson, double-Keggin, and Keggin-sandwich polyoxotungstates are also found to be synergistic but highly cytotoxic . The coexistence of polylysine or protamine sulphate decreased the synergistic potency of the polyoxotungstates, due to their electrostatic interaction with negatively charged polyoxotungstates . Inductively coupled plasma atomic emission spectrometry (ICP) analysis of the polyoxotungstate-treated cells indicated that the polyoxotungstates uptaken in the cell are preferentially located at the membrane fraction with intact composition . The polyoxotungstates depressed not only the production of PBP2', but also the production of beta-lactamase which hydrolyzes beta-lactam antibiotics on the membrane . This leads to the synergistic effect of polyoxotungstates against the MRSA cells in the coexistence of beta-lactam antibiotics which have high affinities to PBPs 1-4 . MRSA cells which were modified to be susceptible to beta-lactam antibiotics during incubation in the presence of polyoxotungstates recovered their resistance to beta-lactam antibiotics when they were subcultured in the absence of the polyoxotungstate.

J Cataract Refract Surg, 1999 Jun, 25(6), 753 - 62
Simultaneous bilateral cataract extraction; Ramsay AL et al.; PURPOSE: To evaluate the visual outcome and safety of simultaneous bilateral cataract extraction . SETTING: Stobhill Hospital NHS Trust, Glasgow, United Kingdom . METHODS: This retrospective case review comprised 259 consecutive patients (518 eyes) who had simultaneous bilateral cataract surgery . Surgeries included bilateral extracapsular procedures, uniocular extracapsular procedures performed simultaneously with a different type of intraocular lens surgery in the other eye, and 1 bilateral intracapsular procedure . Outcome measures were postoperative best spectacle-corrected visual acuity (BSCVA), intraoperative and postoperative complication rates, and conjunctival swab culture results . RESULTS: Eighty-three percent of patients (75% of eyes) with measured preoperative and postoperative BSCVA achieved an acuity of 6/12 or better . Intraoperative and postoperative complication rates were similar to those in previous reports of unilateral extracapsular surgery and simultaneous bilateral cataract surgery . Endophthalmitis occurred in 1 eye (0.19%) . There were no bilateral complications that resulted in visual loss . Cultures were positive from 42% of conjunctival swabs; 81% of positive cultures were coagulase-negative Staphylococcus and 10% were Staphylococcus aureus . CONCLUSIONS: Simultaneous bilateral cataract surgery did not lead to an increased incidence of serious intraoperative or postoperative complications, and visual acuity results were good.

Curr Eye Res, 1999 May, 18(5), 358 - 62
Clarithromycin for experimental Staphylococcus aureus keratitis; Hume EB et al.; PURPOSE: Clarithromycin, a macrolide antibiotic not previously tested against the common causes of bacterial keratitis, was analyzed for its effectiveness in reducing the number of viable bacteria in a Staphylococcus keratitis model . An in vivo comparison of the effectiveness of clarithromycin to erythromycin, minocycline, and tetracycline for three strains of Staphylococcus aureus was done . METHODS: Rabbit eyes were intrastromally injected with 100 colony forming units of one of three strains of S . aureus . Two strains were methicillin-sensitive (ATCC 25923 and MSSA 309) and one strain methicillin-resistant (COL) . Eyes were treated every 30 minutes with 0.3% clarithromycin, erythromycin, tetracycline, or minocycline from 4 to 9 hours postinfection . The number of colony forming units (CFU) per cornea in all eyes was determined at 10 hours postinfection . RESULTS: Vehicle-treated and untreated eyes (controls) contained over 6 logs of CFU per cornea, a value significantly higher than any of the antibiotic-treated eyes (P < or = 0.0001) . Clarithromycin or erythromycin therapy significantly decreased the number of CFU per cornea by approximately 5 logs in the eyes infected with the methicillin-sensitive strains and by approximately 4 logs in the eyes infected with the methicillin-resistant strain . Tetracycline and minocycline were also successful in treating these strains, but overall showed less effectiveness than clarithromycin and erythromycin . CONCLUSIONS: Clarithromycin proved to be an effective ocular medication for the therapy of experimental S . aureus keratitis . The effectiveness of clarithromycin in this model and its known effectiveness for a variety of bacterial pathogens suggests a role for this drug as a useful ocular antibiotic.

J R Coll Surg Edinb, 1999 Jun, 44(3), 161 - 3
Surgical patients with methicillin resistant staphylococcus aureus infection: an analysis of outcome using P-POSSUM; Menon KV et al.; The significance of MRSA infection in surgical patients was studied using the P-POSSUM scoring system . All surgical patients undergoing operation between 1/10/96 and 30/09/97 were prospectively scored using P-POSSUM . A subset of these patients with MRSA infection was analysed using P-POSSUM predicted mortality . Physiological and operative severity scores were compared with non-MRSA surgical patients and length of hospital stay with P-POSSUM matched non-MRSA controls . Thirty of the 1,132 patients were MRSA positive and of these five died, giving a P-POSSUM observed/expected deaths ratio of 1.7 (not significant; 95% CI -0.24 to 0.10) . The P-POSSUM physiology score of 30 MRSA positive patients, compared with the non-MRSA group (n = 1102), was significantly more severe (20.9 v/s 17.4; 95% CI 1.09 to 5.95) as was the operative severity score (15.6 v/s 9.2; 95% CI 4.40 to 8.42) . The length of stay for surviving MRSA positive patients was significantly longer than P-POSSUM matched controls . MRSA infection in surgical patients does not increase mortality . However, patients who contract MRSA infection are more debilitated and have undergone a greater surgical insult.

Nat Med, 1999 Jun, 5(6), 702 - 5
Intra-articularly localized bacterial DNA containing CpG motifs induces arthritis; Deng GM et al.; Unmethylated CpG motifs are often found in bacterial DNA, and exert immunostimulatory effects on hematopoietic cells . Bacteria produce severe joint inflammation in septic and reactive arthritides; bacterial DNA may be involved in this process . We injected bacterial DNA originating from Escherichia coli and Staphylococcus aureus and oligonucleotides containing CpG directly into the knee joints of mice of different strains . Arthritis was seen by histopathology within 2 hours and lasted for at least 14 days . Unmethylated CpG motifs were responsible for this induction of arthritis, as oligonucleotides containing these motifs produced the arthritis . The arthritis was characterized by an influx of monocytic, Mac-1+ cells and by a lack of T lymphocytes . Depletion of monocytes resulted in abrogation of the synovial inflammation . Tumor necrosis factor (TNF)-alpha, a cytokine produced by cells of the monocyte/macrophage lineage, is an important mediator of this disease, as expression of mRNA for TNF-alpha was evident in the inflamed joints, and the CpG-mediated inflammation was abrogated in mice genetically unable to produce this cytokine . These findings demonstrate that bacterial DNA containing unmethylated CpG motifs induces arthritis, and indicate an important pathogenic role for bacterial DNA in septic arthritis.

Arch Intern Med, 1999 Jun 14, 159(11), 1244 - 7
Staphylococcus aureus bacteremia among elderly vs younger adult patients: comparison of clinical features and mortality; McClelland RS et al.; BACKGROUND: Previous studies give conflicting results regarding the effect of age on outcomes in Staphylococcus aureus bacteremia (SAB) . These studies have been limited by retrospective design or small sample size . METHODS: We conducted a prospective cohort study of 385 patients with SAB aged 18 to 90 years . The setting was a large academic medical center . We observed patients from diagnosis of SAB to discharge or death . Discharged patients were contacted 12 weeks after their first positive culture findings . Data were collected on demographics, comorbid conditions, focus of infection, length of stay, and outcome . Primary outcomes were total mortality and death due to SAB . RESULTS: Comparisons were made between 145 patients, aged 66 to 90 years, and 240 patients, aged 18 to 60 years . Forty-three (29.7%) of the elderly patients and 36 (15%) of the younger patients died . Death directly attributable to SAB occurred in 21 (14.5%) older and 15 (6.3%) younger patients . After adjusting for confounding variables, older patients continued to have higher total mortality (odds ratio, 2.21; 95% confidence interval, 1.32-3.70), and higher mortality from SAB (odds ratio, 2.30; 95% confidence interval, 1.13-4.69) . Infection with methicillin-resistant S aureus was associated with higher total mortality in the elderly (odds ratio, 2.59; 95% confidence interval, 1.23-5.43) . CONCLUSIONS: Staphylococcus aureus bacteremia among the elderly is associated with high mortality . Both total mortality and mortality directly attributable to SAB are more than twice as likely in older patients . Infection with methicillin-resistant S aureus carries a worse prognosis than infection with methicillin-sensitive S aureus in the elderly.

Pflugers Arch, 1999 Jul, 438(2), 218 - 23
The role of tumour necrosis factor-alpha (TNF-alpha) in fever and the acute phase reaction in rabbits; Mabika M et al.; We investigated the role of tumour necrosis factor-alpha (TNF-alpha) in fever and the acute phase reaction using a specific type-IV phosphodiesterase inhibitor, rolipram, that inhibits the production of TNF-alpha . The body temperatures and serum iron concentrations of rabbits were measured following injections of lipopolysaccharide (LPS) or Staphylococcus aureus (S . aureus) with either rolipram, diclofenac sodium or the appropriate control solutions . Rolipram significantly (P<0.05) inhibited the first phase of both LPS and Staphylococcal fever, but had no effect on the second phase . The fall in serum iron concentration was not significantly affected by the injection of rolipram together with LPS or S . aureus . These results suggest that TNF-alpha is a pyrogen that plays a role during the first phase of fever, at least . However, TNF-alpha appears not to mediate the fall in serum iron concentration during the acute phase reaction.

Immunol Lett, 1999 Apr 15, 67(3), 157 - 65
Protein A of Staphylococcus aureus evokes Th1 type response in mice; Sinha P et al.; Protein A (PA) of Staphylococcus aureus is known to elicit several cytokines such as IFN gamma, TNF alpha and IL1 . However, it has not been delineated yet as to which differentiation pathway lymphocytes follow after stimulation by PA . In this report, we attempted to collect such evidences . Cytokines, such as IFN gamma, IL2, IL4, IL6, IL10, TNF alpha, IL1alpha and IL1beta were measured in serum by ELISA . Our results show that 1 microg dose of PA stimulates the production of IFN gamma (115 +/- 5 pg/ml), TNF alpha (250 +/- 8 pg/ml) and IL1alpha (100 +/- 5 pg/ml) as compared to control levels of, 22 +/- 2, 20 +/- 2 and 35 +/- 3 pg/ml respectively whereas IL2 and IL1beta secretion were less (beyond the lower detection limit of the kit and 25 +/- 1 pg/ml, respectively) as compared to control (28 +/- 2 and 52 +/- 4 pg/ml, respectively) . Larger dose of PA (10 microg) increases the expression of IL2 (75 +/- 3 pg/ml), TNF alpha (1380 +/- 120 pg/ml), IL1alpha (495 +/- 10 pg/ml) and IL1beta (110 +/- 7 pg/ml) as compared to controls described above . We also observed that 1 microg dose of PA decreases IL4, IL6 and IL10 secretion to 9 +/- 1, 10 +/- 1 and 10 +/- 2 pg/ml, respectively, whereas 10 microg dose also decreased them to 11 +/- 1, 12 +/- 2 and 30 +/- 4 pg/ml, respectively as compared to the background controls, i.e . 50 +/- 5, 50 +/- 2 and 215 +/- 9 pg/ml respectively . The ratio of IFN gamma to IL4 increased and the peak value at 4 h, came to 13 +/- 1 and 9.6 +/- 0.5 with 1 microg and 10 microg PA, respectively, which is an established parameter indicating a Th1 type response . Flow cytometry analysis of CD4+/CD8+ cells, and c-myc protein expression by splenocytes indicate that 1 microg dose of PA causes 2-fold increase of CD4+ cells with no change in CD8+ cells, and 10-fold increase in c-myc protein, whereas 10 microg dose increases CD4+ cells 4-fold, CD8+ cells 3-fold and c-myc protein 100-fold . The cell cycle data shows an induction of apoptosis in thymocytes and splenocytes with the large dose (10 microg), whereas the 1 microg dose does not show any apoptosis . This report indicates that a Th1 response is induced in mice, after PA inoculation at a dose of 1 microg animal . Thus, cytokine mediated therapeutic strategies should consider the fact that an induction of large concentration of some cytokines might become detrimental to the host.

Ned Tijdschr Geneeskd, 1999 May 8, 143(19), 994 - 7
{Prevention of a suspected epidemic of methicillin-resistant staphylococcus aureus (MRSA) in a nursing home}; Hoebe CJ; EPIDEMIC: Following the identification of an index patient with meticillin-resistant Staphylococcus aureus (MRSA) in a Dutch nursing home with 175 residents in the south of Limburg province, the Netherlands (microbiological diagnosis obtained from a foreign laboratory), a survey was carried out to trace contacts by means of the 'ring principle' of outbreak management . If positive cultures were found in the first ring of residents the contact and source tracing was extended . According to the Dutch guidelines for MRSA in nursing homes many preventive measures were taken regarding colonised residents and employees and the cleaning of rooms . Ten days after the occurrence of the index, 29 persons, 9 employees and 20 residents, were diagnosed as colonised with MRSA . Because of this extraordinary count compared with earlier Dutch findings (only 0.16% of inhabitants colonised) there were doubts about the laboratory results . A counter expertise from a Dutch lab and the National Institute of Health and Environmental Hygiene showed no MRSA, but meticillin-sensitive S . aureus . DISCUSSION: This alleged epidemic had very aggravating consequences for residents and employees and large financial consequences for the nursing home . There was a good reaction to the crisis by a multidisciplinary team with external specialists . The Inspectorate of Health emphasized the importance of standardized quality and interpretation of laboratory results by microbiological experts . This should be kept in mind when contracting foreign laboratories specially because the Dutch policy is to strictly avoid MRSA in intramural setting . Verification of diagnosis proved again to be an essential step in outbreak management.

Structure Fold Des, 1999 Mar 15, 7(3), 277 - 87
The structure of a Staphylococcus aureus leucocidin component (LukF-PV) reveals the fold of the water-soluble species of a family of transmembrane pore-forming toxins; Pedelacq JD et al.; BACKGROUND: Leucocidins and gamma-hemolysins are bi-component toxins secreted by Staphylococcus aureus . These toxins activate responses of specific cells and form lethal transmembrane pores . Their leucotoxic and hemolytic activities involve the sequential binding and the synergistic association of a class S and a class F component, which form hetero-oligomeric complexes . The components of each protein class are produced as non-associated, water-soluble proteins that undergo conformational changes and oligomerization after recognition of their cell targets . RESULTS: The crystal structure of the monomeric water-soluble form of the F component of Panton-Valentine leucocidin (LukF-PV) has been solved by the multiwavelength anomalous dispersion (MAD) method and refined at 2.0 A resolution . The core of this three-domain protein is similar to that of alpha-hemolysin, but significant differences occur in regions that may be involved in the mechanism of pore formation . The glycine-rich stem, which undergoes a major rearrangement in this process, forms an additional domain in LukF-PV . The fold of this domain is similar to that of the neurotoxins and cardiotoxins from snake venom . CONCLUSIONS: The structure analysis and a multiple sequence alignment of all toxic components, suggest that LukF-PV represents the fold of any water-soluble secreted protein in this family of transmembrane pore-forming toxins . The comparison of the structures of LukF-PV and alpha-hemolysin provides some insights into the mechanism of transmembrane pore formation for the bi-component toxins, which may diverge from that of the alpha-hemolysin heptamer.

Jpn J Antibiot, 1999 Mar, 52(3), 268 - 77
{Combination effect of teicoplanin and panipenem on highly resistant strains of MRSA}; Utsui Y et al.; We investigated the in vitro combination effect of teicoplanin (TEIC) and panipenem (PAPM) on highly oxacillin-resistant strains of Staphylococcus aureus (MRSA) isolated from various clinical specimens . Combination of TEIC and PAPM using checkerboard titration technique by agar dilution exhibited an excellent effect with mean fractional inhibitory concentration index of 0.18 +/- 0.07 on 47 MRSA strains, and the effects were judged as synergistic against all of the strains tested . In the combination of TEIC and PAPM at 1/4 MIC each against exponentially growing cells of MRSA, good bactericidal activity was found when TEIC and PAPM were added simultaneously, and PAPM was added at 1 or 2 hours prior to addition of TEIC, although the bactericidal activity was scarcely demonstrated when TEIC was added at 1 or 2 hours prior to addition of PAPM . Bactericidal activity against MRSA was enhanced in the combination of TEIC and PAPM at 1/4 MIC each for MRSA than the bactericidal activity of TEIC at 1 MIC alone . TEIC alone showed no bactericidal activity against P . aeruginosa in the mixed cultures with MRSA, while strong bactericidal activity against P . aeruginosa was induced by PAPM . In vitro bactericidal activities against mixed cultures of MRSA with P . aeruginosa were evaluated under conditions of concentrations of TEIC and PAPM, alone and in combination, whose plasma concentrations in human were simulated by a pharmacokinetic simulation model . Bactericidal activity against MRSA was enhanced by the combination of TEIC at 200 mg twice or once daily with PAPM at 500 mg twice daily in comparison with the bactericidal activity of each antibiotic alone, and P . aeruginosa was killed by the antibacterial activity of PAPM.

Acta Orthop Scand, 1999 Apr, 70(2), 199 - 202
Acute spinal epidural abscess without concurrent spondylodiscitis . Successful closed treatment in 10 cases; Ahl T et al.; We performed a retrospective survey of the clinical records and radiological examinations of 10 patients with a diagnosis of spinal epidural abscess, without spondylodiscitis . All patients had an acute onset of fever and local or radiating back pain . 3 patients had mild, and 1 patient severe neurological symptoms . The diagnosis and subsequent regression of the abscess after treatment were verified by MRI . In all cases, the imaging findings included signs of septic arthritis in an adjoining facet joint . 7/10 abscesses were located in the lumbar region . Blood cultures showed Staphylococcus aureus as the etiological agent in 8/10 patients . In 2 cases, no agent was found, probably due to ongoing antibiotic therapy when the cultures were taken . All patients were treated successfully using antibiotics alone, with complete regression of the neurological symptoms.

Ann Intern Med, 1999 May 18, 130(10), 810 - 20
Cost-effectiveness of transesophageal echocardiography to determine the duration of therapy for intravascular catheter-associated Staphylococcus aureus bacteremia; Rosen AB et al.; BACKGROUND: The appropriate duration of therapy for catheter-associated Staphylococcus aureus bacteremia is controversial . Conventional practice dictates that all patients receive prolonged courses of intravenous antibiotics . Some clinicians recommend abbreviated therapeutic courses, but an alternate approach involves prospectively identifying patients for whom abbreviated therapy is appropriate . OBJECTIVE: To determine the cost-effectiveness of transesophageal echocardiography (TEE) in establishing duration of therapy for catheter-associated S . aureus bacteremia . DESIGN: Cost-effectiveness analysis . DATA SOURCES: MEDLINE search of literature; clinical data from patients with S . aureus bacteremia (n = 196) and patients with endocarditis (n = 60); and costs obtained from the study institution, regional home health agency, and national estimates of professional and technical fees . TARGET POPULATION: Patients with catheter-associated S . aureus bacteremia on native heart valves without intravenous drug use or clinically apparent metastatic infection, immunosuppression, or indwelling prosthetic devices . TIME HORIZON: Patient lifetime . PERSPECTIVE: Societal . INTERVENTIONS: Antibiotic treatment based on TEE results compared with 2- or 4-week empirical therapy . OUTCOME MEASURES: Quality-adjusted life expectancy, costs, and incremental cost-effectiveness ratios . RESULTS OF BASE-CASE ANALYSIS: Compared with empirical short-course therapy, the TEE strategy cost $4938 per quality-adjusted life-year (QALY) gained . The effectiveness of the TEE strategy and the effectiveness of the long-course strategy were sufficiently similar that the additional cost of empirical long-course therapy ($1,667,971 per QALY) was higher than that which society usually considers cost-effective . RESULTS OF SENSITIVITY ANALYSES: In a four-way sensitivity analysis (endocarditis prevalence, TEE cost, short-course relapse rate, and TEE specificity), compared with empirical short-course therapy, the TEE strategy results ranged from cost savings to $155,624 per QALY . CONCLUSION: Within the limitations of existing empirical data, this study suggests that for patients with clinically uncomplicated catheter-associated S . aureus bacteremia, the use of TEE to determine therapy duration is a cost-effective alternative to 2- or 4-week empirical therapy.

Philos Trans R Soc Lond B Biol Sci, 1999 Apr 29, 354(1384), 721 - 38
Studies of antibiotic resistance within the patient, hospitals and the community using simple mathematical models; Austin DJ et al.; The emergence of antibiotic resistance in a wide variety of important pathogens of humans presents a worldwide threat to public health . This paper describes recent work on the use of mathematical models of the emergence and spread of resistance bacteria, on scales ranging from within the patient, in hospitals and within communities of people . Model development starts within the treated patient, and pharmacokinetic and pharmacodynamic principles are melded within a framework that mirrors the interaction between bacterial population growth, drug treatment and the immunological responses targeted at the pathogen . The model helps identify areas in which more precise information is needed, particularly in the context of how drugs influence pathogen birth and death rates (pharmacodynamics) . The next area addressed is the spread of multiply drug-resistant bacteria in hospital settings . Models of the transmission dynamics of the pathogen provide a framework for assessing the relative merits of different forms of intervention, and provide criteria for control or eradication . The model is applied to the spread of vancomycin-resistant enterococci in an intensive care setting . This model framework is generalized to consider the spread of resistant organisms between hospitals . The model framework allows for heterogeneity in hospital size and highlights the importance of large hospitals in the maintenance of resistant organisms within a defined country . The spread of methicillin resistant Staphylococcus aureus (MRSA) in England and Wales provides a template for model construction and analysis . The final section addresses the emergence and spread of resistant organisms in communities of people and the dependence on the intensity of selection as measured by the volume or rate of drug use . Model output is fitted to data for Finland and Iceland and conclusions drawn concerning the key factors determining the rate of spread and decay once drug pressure is relaxed.

J Hosp Infect, 1999 May, 42(1), 45 - 51
The influence of methicillin-resistant Staphylococcus aureus (MRSA) carriers in a nursery and transmission of MRSA to their households; Mitsuda T et al.; We examined two persistent MRSA-carrier nurses in a maternity hospital to elucidate the transmission of methicillin-resistant Staphylococcus aureus (MRSA) from healthcare providers to newborn infants and to the nurses' own families . Genotyping of the MRSA strains was performed by analyzing genomic DNA restriction length polymorphisms from pulsed-field gel electrophoresis (PFGE-RFLPs) . The children of these nurses were carrying genotypically identical MRSA strains as their mother . Both MRSA carrier families remained asymptomatic over a two-year follow-up period . Eradication of nasal MRSA carriage from the two nurses resulted in declining MRSA carriage rates among infants in the nursery . Healthcare providers may become transient or persistent MRSA carriers whilst working in hospitals in which MRSA is endemic . They may then become a source of infection for patients as well as their own families . We recommend that healthcare providers should be examined for MRSA if an MRSA epidemic occurs in a hospital . The families of any such carriers should also be examined for MRSA.

J Chromatogr B Biomed Sci Appl, 1999 Apr 30, 727(1-2), 219 - 25
Simple and rapid analytical method for carbapenems using capillary zone electrophoresis; Taniguchi S et al.; A simple and rapid analytical method for carbapenems using high-performance capillary electrophoresis is described . All therapeutic carbapenem injections in Japan (imipenem, panipenem and meropenem) and four other beta-lactams (piperacillin, cefotiam, cefotaxime, latamoxef) were separated and determined with good repeatability in about 10 min using simple free zone capillary electrophoresis . The electrophoresis buffer was 100 mM phosphate buffer of pH 8.0, and a fused-silica capillary of 25 microm I.D . and 47 cm length was adopted . The present method was successfully applied to monitor the degradation of carbapenems under various conditions (at various temperatures or in coexistence with other drugs prescribed in the case of methicillin-resistant Staphylococcus aureus).

J Vasc Surg, 1999 Jun, 29(6), 1090 - 6
Bacterial resistance of refrigerated and cryopreserved aortic allografts in an experimental virulent infection model; Litzler PY et al.; PURPOSE: The bacterial resistance of refrigerated and cryopreserved aortic allografts in a highly virulent infection in a dog model was studied . METHODS: The infrarenal aorta of 12 dogs was replaced with either a cryopreserved aortic allograft (group I, n = 6) or a refrigerated aortic allograft (group II, n = 6) in infected sites . Allografts were harvested from dogs and stored for 1 week, either by cryopreservation (-140 degrees C) or refrigerated method (4 degrees C), in a preservation medium . At the time of implantation, induction of infection was achieved with an infected piece of knitted Dacron placed just beneath the allograft . The Dacron was contaminated in vitro by soaking it in a solution with Staphylococcus aureus PR209 . All 12 dogs received no adjunct antibiotic or antithrombotic therapy . Four weeks after implantation, the animals were killed to recover the grafts for bacteriological and histological analyses . Bacterial results were expressed as colony-forming units (CFU)/cm2 of graft material . RESULTS: In group I, only one allograft grew bacteria at 2 . 16 x 10(6 )CFU/cm2, with a blood culture positive for S aureus . In group II, one dog died at 3 weeks from a false septic aneurysm rupture, all the allografts were infected (P <.05) with a mean bacterial count of 9.41 +/- 6.8 x 10(4) CFU/cm2, and three blood cultures were positive for S aureus . The patency of the grafts was analyzed at the time of recovery . Three laminar thrombi without occlusion were present in group I; none were present in group II . A better preserved endothelium in group I was revealed by means of histologic analysis staining with factor VIII antibody before implantation . After 4 weeks of implantation in the infected site, infected allografts presented polynuclear infiltrates in the media with a high degree of inflammatory reaction, and endothelial recovery was more significant in group I, with numerous young plump cells . CONCLUSION: This study demonstrates that cryopreserved allografts implanted in infected sites in a dog model can produce greater bacterial resistance.

Proc Natl Acad Sci U S A, 1999 Jun 8, 96(12), 7005 - 10
Unexpected abundance of self-splicing introns in the genome of bacteriophage Twort: introns in multiple genes, a single gene with three introns, and exon skipping by group I ribozymes; Landthaler M et al.; Analysis of RNA that can be labeled with GTP indicates the existence of group I introns in genes of at least three transcriptional classes in the genome of Staphylococcus aureus bacteriophage Twort . A single ORF of 142 amino acids (Orf142) is interrupted by three self-splicing group I introns, providing the first example of a phage gene with multiple intron insertions . Twort Orf142 is encoded in a message that is abundant 15-20 min after infection and is highly similar to a late gene product (Orf8) of the morphologically related Listeria phage A511 . The introns in orf142 are spliced in vivo and contain all the conserved features of primary sequence and secondary structure of group I introns in subgroup IA2, which includes the introns in Escherichia coli phage T4 and the Bacillus phages beta22 and SPO1 . Introns I2 and I3 in orf142 are highly similar, and their intron insertion sites are closely spaced . The presence of transcripts with a skipped exon between these introns indicates that they may fold into a single active ribozyme resulting in alternative splicing . Alternatively, the cleaved 5' exon preceding I2 may undergo trans splicing to the 3' exon that follows I3 . Regardless of the detailed mechanism, these results demonstrate a new means whereby a single gene can give rise to multiple messenger RNAs.

Biochem J, 1999 Jun 15, 340 ( Pt 3), 657 - 69
Protein modification during biological aging: selective tyrosine nitration of the SERCA2a isoform of the sarcoplasmic reticulum Ca2+-ATPase in skeletal muscle; Viner RI et al.; The accumulation of covalently modified proteins is an important hallmark of biological aging, but relatively few studies have addressed the detailed molecular-chemical changes and processes responsible for the modification of specific protein targets . Recently, Narayanan et al . {Narayanan, Jones, Xu and Yu (1996) Am . J . Physiol . 271, C1032-C1040} reported that the effects of aging on skeletal-muscle function are muscle-specific, with a significant age-dependent change in ATP-supported Ca2+-uptake activity for slow-twitch but not for fast-twitch muscle . Here we have characterized in detail the age-dependent functional and chemical modifications of the rat skeletal-muscle sarcoplasmic-reticulum (SR) Ca2+-ATPase isoforms SERCA1 and SERCA2a from fast-twitch and slow-twitch muscle respectively . We find a significant age-dependent loss in the Ca2+-ATPase activity (26% relative to Ca2+-ATPase content) and Ca2+-uptake rate specifically in SR isolated from predominantly slow-twitch, but not from fast-twitch, muscles . Western immunoblotting and amino acid analysis demonstrate that, selectively, the SERCA2a isoform progressively accumulates a significant amount of nitrotyrosine with age (approximately 3.5+/-0 . 7 mol/mol of SR Ca2+-ATPase) . Both Ca2+-ATPase isoforms suffer an age-dependent loss of reduced cysteine which is, however, functionally insignificant . In vitro, the incubation of fast- and slow-twitch muscle SR with peroxynitrite (ONOO-) (but not NO/O2) results in the selective nitration only of the SERCA2a, suggesting that ONOO- may be the source of the nitrating agent in vivo . A correlation of the SR Ca2+-ATPase activity and covalent protein modifications in vitro and in vivo suggests that tyrosine nitration may affect the Ca2+-ATPase activity . By means of partial and complete proteolytic digestion of purified SERCA2a with trypsin or Staphylococcus aureus V8 protease, followed by Western-blot, amino acid and HPLC-electrospray-MS (ESI-MS) analysis, we localized a large part of the age-dependent tyrosine nitration to the sequence Tyr294-Tyr295 in the M4-M8 transmembrane domain of the SERCA2a, close to sites essential for Ca2+ translocation.

J Med Microbiol, 1999 Jun, 48(6), 515 - 21
Occurrence of methicillin-resistant and -susceptible Staphylococcus aureus within a single colony contributing to MRSA mis-identification; Falcao MH et al.; Many methods have been described for the detection of methicillin-resistant Staphylococcus aureus (MRSA), but the homogeneous or heterogeneous expression of methicillin resistance affects the reliability of those methods . This study demonstrates that close association between methicillin-susceptible S . aureus (MSSA) and MRSA strains in the host colonisation site can present additional problems for the detection of MRSA in clinical laboratories, which may contribute to failure in the control of MRSA infection in hospital . Worse, this association may also account for the emergence of MRSA during antibiotic therapy.

J Immunol, 1999 Jun 15, 162(12), 7402 - 8
Protection by group II phospholipase A2 against Staphylococcus aureus; Laine VJ et al.; Group II phospholipase A2 (PLA2) is an enzyme that has marked antibacterial properties in vitro . To define the role of group II PLA2 in the defense against Staphylococcus aureus, we studied host responses in transgenic mice expressing human group II PLA2 and group II PLA2-deficient C57BL/6J mice in experimental S . aureus infection . After the administration of S . aureus, the transgenic mice showed increased expression of group II PLA2 mRNA in the liver and increased concentration of group II PLA2 in serum, whereas the PLA2-deficient mice completely lacked the PLA2 response . Expression of human group II PLA2 resulted in reduced mortality and improved the resistance of the mice by killing the bacteria as indicated by low numbers of live bacteria in their tissues . Human group II PLA2 was responsible for the bactericidal activity of transgenic mouse serum . These results suggest a possible role for group II PLA2 in the innate immunity against S . aureus infection.

Semin Thromb Hemost, 1999, 25(2), 217 - 21
Thrombotic microangiopathy manifesting as thrombotic thrombocytopenic purpura/hemolytic uremic syndrome in the cancer patient; Gordon LI et al.; The complication of thrombotic thrombocytopenic purpura or hemolytic uremic syndrome (TTP/HUS) can occur in cancer patients . It is characterized by a microangiopathic hemolytic anemia, severe thrombocytopenia, and renal failure . Pulmonary manifestations, especially pulmonary edema, are a common observation . Neurologic changes are also frequently seen . The etiology is unknown at this time . It has been observed in many different types of cancer and is most commonly seen in gastric adenocarcinoma followed by carcinoma of the breast, colon, and small cell lung carcinoma . The hemolysis can be massive and is due to red cell fragmentation, as schistocytes are present in all the cases . Though immune complexes are present in the plasma, the antiglobulin (Coomb's) test is negative . Chemotherapeutic agents, especially mitomycin C, have been implicated as causative factors . There is a correlation of this complication with the cumulative dose . However, chemotherapy cannot account for all the cases as the syndrome can occur in untreated patients . It can be differentiated from disseminated intravascular coagulation by the absence of a coagulopathy . Management should consist of plasma exchange, use of a Staphylococcus aureus column (Prosorba), and control of hypertension . Because of the susceptibility to pulmonary edema, blood volume overloading should be avoided.

Kansenshogaku Zasshi, 1999 Apr, 73(4), 328 - 35
{Soluble proteins from Staphylococcus aureus can change expression of CD11b and CD62L, but not H2O2 production by human blood granulocytes}; Onogawa T et al.; We examined the production of CD11b, CD62L and H2O2 by human peripheral blood granulocytes after treatment with soluble proteins prepared from five different pressure-disrupted strains of Staphylococcus aureus (SaSP) by flow cytometory . Peripheral blood was treated with final SaSP concentrations of 0.05, 0.5 and 5.0 micrograms for 20 min at 37 degrees C . The ratio of CD11b positive granulocytes did not increase at concentrations from 0.05 to 5.0 micrograms, but fluorescence intensity showed about two and three-fold increase, respectively, at concentrations of 0.5 and 5.0 micrograms, in comparison with that of control cells . The ratio CD62L positive cells decreased as follows: 0.5 microgram, 53.8% and 5.0 micrograms, 19.0%, respectively, whereas the control value was 79.8% . Fluorescence intensity also decreased as follows: 0.5 microgram, 10.4 and 5.0 micrograms, 9.2, respectively, whereas the control value was 46.8 . Slight induction of H2O2 was found at 5.0 micrograms concentration only . In addition, SaSP treatment granulocytes that stimulated with PMA (1 ng) increased H2O2 production . Thus, SaSP has no beneficial effect against H2O2 production by granulocytes . All of the SaSP preparations indicated similar results for the production of CD11b, CD62L and H2O2 by granulocytes . SaSP effects activation of granulocytes, and the activation may occur independently of protein kinase C.

Epidemiol Infect, 1999 Apr, 122(2), 329 - 36
Coagulase gene polymorphism of Staphylococcus aureus isolates from dairy cattle in different geographical areas; Su C et al.; The objectives of this study were to investigate the coagulase gene polymorphism of Staphylococcus aureus isolates obtained from bovine mastitic milk and to determine the resistance of predominant and rare coagulase genotypes to bovine blood neutrophil bactericidal activities . A total of 453 isolates were collected from four countries: the Czech Republic, France, Korea and the United States . The isolates were subtyped into 40 types by restriction fragment length polymorphism (RFLP) of the coagulase gene . Twenty-three strains from predominant and rare genotypes were evaluated for their ability to resist neutrophil bactericidal activities . There were significant (P < 0.01) differences in the average percent neutrophil killing of the predominant (16.7%) and rare (39.7%) genotypes when bacteria were opsonized with antiserum . The results indicate that the profiles of coagulase genotype differ among geographic locations, and only a few genotypes prevail in each location . In addition, the predominant genotypes were more resistant to neutrophil bactericidal activities than rare genotypes.

Epidemiol Infect, 1999 Apr, 122(2), 241 - 9
Analysis of genomic diversity within the Xr-region of the protein A gene in clinical isolates of Staphylococcus aureus; Kobayashi N et al.; Protein A of Staphylococcus aureus contains a polymorphic Xr-region characterized by a tandem repeat of eight amino acid units . In this study, the diversity of genes encoding the repeat regions and their relatedness among S . aureus strains was analyzed . Ten different protein-A types characterized by repeat numbers 4-13 were identified in a total of 293 clinical isolates . The protein-A type with 10 repeat units (10 repeats) in the Xr-region was most frequently detected in methicillin-resistant S . aureus, whereas the majority of methicillin-susceptible strains were distributed almost evenly into protein-A types with 7-11 repeats . Strains that belonged to a single coagulase type were classified into multiple protein-A types, e.g . strains with the common coagulase types II and VII were differentiated into 7 and 8 protein-A types, respectively . Nucleotide sequence analysis of the Xr-region of 42 representative strains revealed the presence of 37 different genotypes (spa types), which were constituted by a combination of several of 24 different repeat unit genotypes . Based on the similarity in arrangement of repeat unit genotypes, 34 strains with different repeat numbers were classified into 5 genetic clusters (C1-C5) . The clusters C1, C2 and C3 consisted exclusively of strains with identical coagulase types II, III, and IV, respectively . These findings suggested that the protein-A gene of S . aureus has evolved from a common ancestral clone in individual clusters independently.

Epidemiol Infect, 1999 Apr, 122(2), 227 - 33
Phages for methicillin-resistant Staphylococcus aureus: an international trial; Richardson JF et al.; An internationally agreed and validated set of phages is used worldwide for the typing of strains of Staphylococcus aureus of human origin . However, because of the sometimes reduced susceptibility of methicillin-resistant strains (MRSA) to these phages, some of the national typing centres use locally isolated and characterized sets of experimental phages . In this trial, 42 such phages were distributed to 6 centres and tested against 744 isolates of MRSA with the intention of defining a phage set to augment the international set . The use of these experimental phages increased the percentage typability from 75% with the international set to 93% and the number of identifiable lytic patterns from 192 to 424 . A subset of 10 experimental phages was selected . When this subset was compared with the experimental panel, the typability rate was 91% and 370 distinct patterns were obtained . This subset of phages has been distributed for international trial.

Unfallchirurg, 1999 Apr, 102(4), 324 - 8
{Nosocomial infections with methicillin-resistant Staphylococcus aureus (MRSA) and epidermidis (MRSE) strains . Their importance, prophylaxis and therapy in orthopedic surgery}; Konig DP et al.; MRSA/MRSE infections are a major problem in hospitals and although in orthopaedic units the incidence is low awareness of this problem is necessary . Once a MRSA strain has been isolated the strict use of the hygiene precautions has to be applied to avoid epidemic spread of the strain . The patient has to be isolated . The staff has to use gloves and gowns whilst treating the patient . A antimicrobiel hand wash solution has to be used after taking off the gloves and before leaving the isolation room . Patient and staff have to be informed about the pathogenicity and the way of infection spread so that infection precaution rules are fulfilled . Antibiotics should only be used in clinically well defined cases and the overall use of antibiotics should be reduced to lower the incidence of MRSA/E isolates . The problems of an MRSA case and its successful treatment are demonstrated.

Diagn Microbiol Infect Dis, 1999 Jun, 34(2), 77 - 81
Detection of ileS-2 gene encoding mupirocin resistance in methicillin-resistant Staphylococcus aureus by multiplex PCR; Nunes EL et al.; The presence of the ileS-2 gene, responsible for mupirocin resistance, in clinical isolates of methicillin-resistant Staphylococcus aureus was determined by multiplex polymerase chain reaction . Three pairs of primers were used, which yielded specific fragments of femA (encoding a unique feature of S . aureus), mecA (encoding resistance to methicillin) and ileS-2 genes . The multiplex polymerase chain reaction system is an easy and time-saving technique that, together with a rapid method for DNA extraction by boiling, may be incorporated as a routine analysis in clinical diagnostic laboratories.

Pediatr Infect Dis J, 1999 May, 18(5), 410 - 4
Methicillin-resistant and borderline methicillin-resistant asymptomatic Staphylococcus aureus colonization in children without identifiable risk factors; Suggs AH et al.; BACKGROUND: The recent evolution in the epidemiology of methicillin-resistant asymptomatic Staphylococcus aureus (MRSA) infections in children, whereby children without traditional risk factors for MRSA have been hospitalized in increasing numbers, prompted us to establish whether a parallel increase in "asymptomatic" MRSA colonization had occurred . METHODS: We cultured the nares and perineum of 500 children attending our Pediatric Emergency Department . RESULTS: One hundred thirty-two (26.4%) of these children were colonized with S . aureus . Eleven (8.3%) of the S . aureus isolates were MRSA; 4 (36.4%) of the 11 subjects colonized with MRSA had no risk factors . Seven (5.3%) of the 132 S . aureus isolates were borderline methicillin-resistant S . aureus (BRSA); 5 (71.4%) of the 7 subjects colonized with BRSA had no MRSA risk factors . CONCLUSIONS: These findings indicate that MRSA and BRSA isolates are circulating in the community and that MRSA isolates are no longer confined to children with frequent contact with a health care environment.

Circulation, 1999 Jun 1, 99(21), 2791 - 7
Acetylsalicylic acid reduces vegetation bacterial density, hematogenous bacterial dissemination, and frequency of embolic events in experimental Staphylococcus aureus endocarditis through antiplatelet and antibacterial effects; Kupferwasser LI et al.; BACKGROUND: Platelets are integral to cardiac vegetations that evolve in infectious endocarditis . It has been postulated that the antiplatelet aggregation effect of aspirin (ASA) might diminish vegetation evolution and embolic rates . METHODS AND RESULTS: Rabbits with Staphylococcus aureus endocarditis were given either no ASA (controls) or ASA at 4, 8, or 12 mg . kg-1 . d-1 IV for 3 days beginning 1 day after infection . Vegetation weights and serial echocardiographic vegetation size, vegetation and kidney bacterial densities, and extent of renal embolization were evaluated . In addition, the effect of ASA on early S aureus adherence to sterile vegetations was assessed . In vitro, bacterial adherence to platelets, fibrin matrices, or fibrin-platelet matrices was quantified with either platelets exposed to ASA or S aureus preexposed to salicylic acid (SAL) . ASA at 8 mg . kg-1 . d-1 (but not at 4 or 12 mg . kg-1 . d-1) was associated with substantial decreases in vegetation weight (P<0.05), echocardiographic vegetation growth (P<0.001), vegetation (P<0.05) and renal bacterial densities and renal embolic lesions (P<0.05) versus controls . Diminished aggregation resulted when platelets were preexposed to ASA or when S aureus was preexposed to SAL (P<0.05) . S aureus adherence to sterile vegetations (P<0.05) or to platelets in suspension (P<0.05), fibrin matrices (P<0.05), or fibrin-platelet matrices (P<0.05) was significantly reduced when bacteria were preexposed to SAL . CONCLUSIONS: ASA reduces several principal indicators of severity and metastatic events in experimental S aureus endocarditis . These benefits involve ASA effects on both the platelet and the microbe.

Biochemistry, 1999 May 18, 38(20), 6689 - 98
Structure of the agonist-binding sites of the Torpedo nicotinic acetylcholine receptor: affinity-labeling and mutational analyses identify gamma Tyr-111/delta Arg-113 as antagonist affinity determinants; Chiara DC et al.; Photoaffinity labeling of the Torpedo nicotinic acetylcholine receptor (nAChR) with {3H}d-tubocurarine (dTC) has identified a residue within the gamma-subunit which, along with the analogous residue in delta-subunit, confers selectivity in binding affinities between the two agonist sites for dTC and alpha-conotoxin (alpha Ctx) MI . nAChR gamma-subunit, isolated from nAChR-rich membranes photolabeled with {3H}dTC, was digested with Staphylococcus aureus V8 protease, and a 3H-labeled fragment was purified by reversed-phase high-performance liquid chromatography . Amino-terminal sequence analysis of this fragment identified 3H incorporation in gamma Tyr-111 and gamma Tyr-117 at about 5% and 1% of the efficiency of {3H}dTC photoincorporation at gamma Trp-55, the primary site of {3H}dTC photoincorporation within gamma-subunit {Chiara, D . C., and Cohen, J . B . (1997) J . Biol . Chem 272, 32940-32950} . The Torpedo nAChR delta-subunit residue corresponding to gamma Tyr-111 (delta Arg-113) contains a positive charge which could confer the lower binding affinity seen for some competitive antagonists at the alpha-delta agonist site . To test this hypothesis, we examined by voltage-clamp analysis and/or by {125I}alpha-bungarotoxin competition binding assays the interactions of acetylcholine (ACh), dTC, and alpha Ctx MI with nAChRs containing gamma Y111R or delta R113Y mutant subunits expressed in Xenopus oocytes . While these mutations affected neither ACh equilibrium binding affinity nor the concentration dependence of channel activation, the gamma Y111R mutation decreased by 10-fold dTC affinity and inhibition potency . Additionally, each mutation conferred a 1000-fold change in the equilibrium binding of alpha Ctx MI, with delta R113Y enhancing and gamma Y111R weakening affinity . Comparison of these results with previous results for mouse nAChR reveals that, while the same regions of gamma- (or delta-) subunit primary structure contribute to the agonist-binding sites, the particular amino acids that serve as antagonist affinity determinants are species-dependent.

Biochemistry, 1999 May 18, 38(20), 6537 - 46
Penicillin-binding protein 2a from methicillin-resistant Staphylococcus aureus: kinetic characterization of its interactions with beta-lactams using electrospray mass spectrometry; Lu WP et al.; Penicillin-binding protein 2a (PBP2a) is the primary beta-lactam resistance determinant of methicillin-resistant Staphylococcus aureus (MRSA) . MecA, the gene coding for PBP2a, was cloned with the membrane-anchoring region at the N-terminus deleted . The truncated protein (PBP2a) was overexpressed in Escherichia coli mostly in the soluble form accounting for approximately 25% of soluble cell protein and was purified to homogeneity . The purified protein was shown to covalently bind beta-lactams in an 1:1 ratio as determined by electrospray mass spectrometry . A novel method based on HPLC-elctrospray mass spectrometry has been developed to quantitatively determine the formation of the covalent adducts or acyl-PBP2a complexes . By using this method, combined with kinetic techniques including quench flow, we have extensively characterized the interactions between PBP2a and three beta-lactams and determined related kinetic parameters for the first time . The apparent first-order rate constants (ka) of PBP2a acylation by benzylpenicillin showed a hyperbolic dependence on the concentration of benzylpenicillin . This is consistent with the mechanism that the binding of the penicillin to PBP2a consists of reversible formation of a Michaelis complex followed by formation of the penicilloyl-PBP2a adduct, and allowed the determination of the individual kinetic parameters for these two steps, the dissociation constant Kd of 13.3 mM and the first-order rate constant k2 of 0.22 s-1 . From these values, the second-order rate constant k2/Kd, the value reflecting the overall binding efficiency of a beta-lactam, of 16.5 M-1 s-1 was obtained . The fairly high Kd value indicates that benzylpenicillin fits rather poorly into the protein active site . Similar studies on the interaction between PBP2a and methicillin revealed k2 of 0.0083 s-1 and Kd of 16.9 mM, resulting in an even smaller k2/Kd value of 0.49 M-1 s-1 . The rate constants k3 for deacylation of the acyl-PBP2a complexes, the third step in the interactions, were measured to be <1.5 x 10(-)5 s-1 . These results indicate that the resistance of PBP2a to penicillin inactivation is mainly due to the extremely low penicillin acylating rate in addition to the low association affinity, but not to a fast rate of deacylation . Acylation of PBP2a by a high-affinity cephalosporin, Compound 1, also followed a saturation curve of ka versus the compound concentration, from which k2 = 0.39 s-1, Kd = 0.22 mM, and k2/Kd = 1750 M-1 s-1 were obtained . The 100-fold increase in the k2/Kd value as compared with that of benzylpenicillin is mostly attributable to the decreased (60-fold) Kd, indicating that the cephalosporin fits much better to the binding pocket of the protein.

Age Ageing, 1999 Mar, 28(2), 229 - 32
Nasal colonization by Staphylococcus aureus in active, independent, community seniors; Lee YL et al.; OBJECTIVE: to evaluate the prevalence of nasal colonization with Staphylococcus aureus (SA) in active, independent community seniors and old people in a nursing home . DESIGN: cross-sectional brief questionnaire and screening culture of anterior nares specimens from 165 elders at a community centre and cross-sectional data from a recent survey in a nursing home . RESULTS: the prevalence of SA colonization in community seniors (27%) was similar to that in the nursing home (29%) . The proportion of SA isolates that were methicillin-resistant was much lower in the community seniors (2.3%) than in the nursing-home residents (31%) . There was less antibiotic resistance in those living at home . CONCLUSION: in community seniors the prevalence of SA colonization was similar to that in nursing-home residents, but the prevalence of methicillin-resistant SA was lower . Susceptibility patterns of antibiotics tested against the SA showed less resistance than isolates from nursing-home patients.

J Antimicrob Chemother, 1999 Apr, 43(4), 593 - 6
Concentration and bactericidal activity of fusidic acid and cloxacillin in serum and synovial fluid; Somekh E et al.; Fusidic acid and cloxacillin were studied in patients who underwent joint aspiration for noninfectious disorders . Nine patients were given oral 500 mg fusidic acid tid for 72 h, the last dose being given 4, 8 or 12 h before the joint aspiration . Cloxacillin was administered in a single 2 g iv dose to 9 patients, 0.5, 4 or 8 h before the aspiration . Bactericidal activity was determined against five isolates each of methicillin-susceptible and methicillin-resistant Staphylococcus aureus . Satisfactory activity (> or = 1:3) was detected in the serum in patients who received fusidic acid, while in the synovial fluids titres reflected borderline effectiveness (c . 1:2) . Despite drug concentrations and excellent MICs, fusidic acid demonstrated markedly lower inhibitory and bactericidal activity against S . aureus than did cloxacillin.

J Antimicrob Chemother, 1999 Apr, 43(4), 589 - 91
Effect of teicoplanin on isolation of Staphylococcus aureus from blood culture media; Chern IF et al.; Intraoperative bacteraemia has been used as an indicator of the efficacy of prophylactic antibiotics . Two clinical isolates of Staphylococcus aureus in nutrient broth, with or without human serum, were exposed to teicoplanin (50 mg/L) and, either immediately or after 30 min, inoculated into blood culture bottles . Bottles with and without resin were used and the experiment was repeated five times with one strain . In the absence of teicoplanin, an inoculum of 10 cfu/mL produced growth in both resin and non-resin bottles . In the presence of teicoplanin, an inoculum of at least 10(5) cfu/mL was required in non-resin bottles to obtain growth, but this was reduced to 10(2)-10(3) cfu/mL for resin bottles . Intraoperative blood cultures overestimate the efficacy of bacterial killing by prophylactic antibiotics during surgery.

J Antimicrob Chemother, 1999 Apr, 43(4), 467 - 75
Evaluation of a new 3-h hybridization method for detecting the mecA gene in Staphylococcus aureus and comparison with existing genotypic and phenotypic susceptibility testing methods; Skov RL et al.; A new 3-h hybridization assay for detection of the staphylococcal mecA gene and the Staphylococcus aureus nuclease gene was evaluated by comparing the assay with existing genotypic and phenotypic methods . A total of 275 S . aureus strains were tested, including 257 epidemiologically unrelated strains (135 mecA-positive and 122 mecA-negative; collection I), and 18 strains with known borderline resistance to methicillin (collection II) . Complete agreement was obtained for both collections when comparing the new assay with genotypic methods . We further evaluated a range of phenotypic susceptibility methods recommended in Europe and/or USA using the presence of the mecA gene as the defining standard . For collection I a high degree of agreement was found for both Etests (256 strains) and the oxacillin screen plate test (255 strains); the degree of agreement was lower for agar dilution methicillin (250 strains) and oxacillin 1 microg discs (239 strains) . For the borderline strains a high degree of agreement was only obtained by the oxacillin screen plate test (17 of 18 strains) . The other tests were less accurate, in the following order: agar dilution methicillin, Etest methicillin, Etest oxacillin and oxacillin discs with disagreement for four, five, nine and 13 strains, respectively . In conclusion, the new hybridization assay is a rapid and exact method for detecting the mecA gene and the S . aureus nuclease gene . This study confirms that phenotypic tests for methicillin resistance in S . aureus strains creates both false-susceptible and false-resistant results, especially for borderline resistant strains.

Infect Control Hosp Epidemiol, 1999 May, 20(5), 362 - 6
Issues in the management of resistant bacteria in long-term-care facilities; Bradley SF; The prevalence of antibiotic-resistant bacteria in the long-term-care setting and the risk to nursing home residents is still unknown . Few studies have been done in community-based nursing homes, and most have focused on colonization rather than infection rates . Concerns about methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci have been expressed most often, while relatively scant attention has been paid to the problem of antibiotic resistance in gram-negative bacilli . Antibiotic resistance precautions need to be developed for nursing homes that are simple, effective, inexpensive, and recognize the unique rehabilitative and long-term custodial missions of chronic-care facilities.

Infect Control Hosp Epidemiol, 1999 May, 20(5), 353 - 5
Outbreak of methicillin-resistant Staphylococcus aureus in a German tertiary-care hospital; Ruchel R et al.; A biphasic outbreak of methicillin-resistant Staphylococcus aureus in intensive-care units of a German tertiary-care hospital afflicted 89 patients within 4 years . The spread of the outbreak most likely was facilitated by the contamination of mobile radiograph equipment . The outbreak was controlled by measures of hospital hygiene.

Infect Control Hosp Epidemiol, 1999 May, 20(5), 351 - 3
Bacitracin versus mupirocin for Staphylococcus aureus nasal colonization; Soto NE et al.; We performed a randomized prospective study of 5-day treatment with topical mupirocin or bacitracin for the elimination of Staphylococcus aureus nasal colonization in healthcare workers (HCWs) . Nasal cultures were obtained from 141 HCWs, 37 (26%) of whom showed S . aureus . After 72 to 96 hours of treatment, the organism was eradicated in 15 (94%) of 16 by mupirocin and in 8 (44%) of 18 by bacitracin (P = .0031) . Similar efficacy was demonstrated at 30 days . Mupirocin may be more effective than bacitracin for eradication of S . aureus in healthy HCWs.

Medicina (B Aires), 1999, 59(1), 43 - 8
{Risk factors for nosocomial bacterial infection in children: a case-control study}; Paganini HR et al.; With the objective to identify independent risk factors associated with the development of nosocomial bacteremia, we have performed a prospective, exploratory, case-control study . All non-neutropenic children with nosocomial bacteremia admitted during a seven-month period were eligible . All children non-neutropenic without nosocomial bacteremia were eligible as controls . The incidence of bacteremia in the study population was 11.3/1000 admissions . Ninety one cases and ninety nine controls were analyzed . In 46% of patients clinical foci were detected . The catheter-related infection was the most frequently founded . Staphylococcus spp coagulase negative, Staphylococcus aureus and Klebsiella pneumoniae were the microorganisms more frequently isolated . Multivariate analysis identified five risk factors independently associated with nosocomial bacteremia: admission outside of Intensive Care Units (ICU) (OR: 8.14, 2.60-25.5), previous antibiotic treatment (OR: 5.02, 2.18-11.5), invasive procedures (OR: 5.35, 1.70-16.8), without surgery (OR: 2.99, 1.37-6.52) and the presence of central venous lines (OR: 5.35, 2.13-12.4) . Our data give strong support for the value of testing strict guidelines for limiting vascular catheter and antibiotic use, and limiting the invasive procedures.

Antimicrob Agents Chemother, 1999 Jun, 43(6), 1449 - 58
Cloning and nucleotide sequence determination of the entire mec DNA of pre-methicillin-resistant Staphylococcus aureus N315; Ito T et al.; In methicillin-resistant Staphylococcus aureus, the methicillin resistance gene mecA is localized within a large chromosomal region which is absent in the methicillin-susceptible S . aureus chromosome . The region, designated mec DNA, is speculated to have originated from the genome of another bacterial species and become integrated into the chromosome of the S . aureus cell in the past . We report here cloning and determination of the structure of the entire mec DNA sequence from a Japanese S . aureus strain, N315 . The mec DNA was found to be 51,669 bp long, including terminal inverted repeats of 27 bp and a characteristic pair of direct repeat sequences of 15 bp each: one is situated in the right extremity of mec DNA, and the other is situated outside the mec DNA and abuts the left boundary of mec DNA . The integration site of mec DNA was found to be located in an open reading frame (ORF) of unknown function, designated orfX . Clusters of antibiotic resistance genes were noted in mec DNA carried by transposon Tn554 and an integrated copy of plasmid pUB110 . Both the transposon and plasmid were integrated in the proximity of the mecA gene, the latter being flanked by a pair of insertion sequence IS431 elements . Many ORFs other than those encoding antibiotic resistance were considered nonfunctional because of the acquired mutations or partial deletions found in the ORFs . Two ORFs potentially encoding novel site-specific recombinases were found in mec DNA . However, there was no ORF that might encode mec DNA-specific transposase or integrase proteins, indicating that the mec DNA is not a transposon or a bacteriophage in nature.

Antimicrob Agents Chemother, 1999 Jun, 43(6), 1429 - 34
Characterization of novel antimicrobial peptoids; Goodson B et al.; Peptoids differ from peptides in that peptoids are composed of N-substituted rather than alpha-carbon-substituted glycine units . In this paper we report the in vitro and in vivo antibacterial activities of several antibacterial peptoids discovered by screening combinatorial chemistry libraries for bacterial growth inhibition . In vitro, the peptoid CHIR29498 and some of its analogues were active in the range of 3 to 12 microg/ml against a panel of gram-positive and gram-negative bacteria which included isolates which were resistant to known antibiotics . Peptoid antimicrobial activity against Staphylococcus aureus was rapid, bactericidal, and independent of protein synthesis . beta-Galactosidase and propidium iodide leakage assays indicated that the membrane is the most likely target of activity . Positional isomers of an active peptoid were also active, consistent with a mode of action, such as membrane disruption, that does not require a specific fit between the molecule and its target . In vivo, CHIR29498 protected S . aureus-infected mice in a simple infection model.

Antimicrob Agents Chemother, 1999 Jun, 43(6), 1324 - 8
Molecular investigation of the postantibiotic effects of clarithromycin and erythromycin on Staphylococcus aureus cells; Champney WS et al.; The kinetics of recovery after inhibition of growth by erythromycin and clarithromycin were examined in Staphylococcus aureus cells . After inhibition for one mass doubling by 0.5 microg of the antibiotics/ml, a postantibiotic effect (PAE) of 3 and 4 h duration was observed for the two drugs before growth resumed . Cell viability was reduced by 25% with erythromycin and 45% with clarithromycin compared with control cells . Erythromycin and clarithromycin treatment reduced the number of 50S ribosomal subunits to 24 and 13% of the number found in untreated cells . 30S subunit formation was not affected . Ninety minutes was required for resynthesis to give the control level of 50S particles . Protein synthesis rates were diminished for up to 4 h after the removal of the macrolides . This continuing inhibition of translation was the result of prolonged binding of the antibiotics to the 50S subunit as measured by 14C-erythromycin binding to ribosomes in treated cells . The limiting factors in recovery from macrolide inhibition in these cells, reflected as a PAE, are the time required for the synthesis of new 50S subunits and the slow loss of the antibiotics from ribosomes in inhibited cells.

Science, 1999 May 28, 284(5419), 1523 - 7
Broadly protective vaccine for Staphylococcus aureus based on an in vivo-expressed antigen; McKenney D et al.; Vaccines based on preferential expression of bacterial antigens during human infection have not been described . Staphylococcus aureus synthesized poly-N-succinyl beta-1-6 glucosamine (PNSG) as a surface polysaccharide during human and animal infection, but few strains expressed PNSG in vitro . All S . aureus strains examined carried genes for PNSG synthesis . Immunization protected mice against kidney infections and death from strains that produced little PNSG in vitro . Nonimmune infected animals made antibody to PNSG, but serial in vitro cultures of kidney isolates yielded mostly cells that did not produce PNSG . PNSG is a candidate for use in a vaccine to protect against S . aureus infection.

Am J Med, 1999 May 3, 106(5A), 11S - 18S; discussion 48S-52S
Control of methicillin-resistant Staphylococcus aureus in the hospital setting; Herwaldt LA; Methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of nosocomial infections . Healthcare professionals in the United States should develop programs to prevent transmission of this organism within their institutions . Aggressive control efforts are justified for several reasons: (1) the incidence of nosocomial MRSA reflects the general effectiveness of infection control practice; (2) MRSA do not replace susceptible strains but instead increase the overall rate of nosocomial S . aureus infections; (3) MRSA infections cause substantial morbidity and mortality; (4) serious MRSA infections must be treated with vancomycin . Thus, in hospitals with high rates of MRSA, use of this antimicrobial agent increases, which in turn may increase the risk for selecting vancomycin-resistant enterococci . Hospitals have used numerous different approaches to control nosocomial spread of MRSA . Staff should choose a control method based on the prevalence of MRSA in their institution and in their referring facilities, the rate of nosocomial transmission of MRSA in their hospital, the risk factors present in their patient population, the reservoirs and modes of transmission specific to their hospital, and their resources . Any MRSA control plan must stress adherence to basic infection control measures, such as hand washing and contact isolation precautions . In addition, decolonization of patients and staff, control of antimicrobial use, surveillance cultures, and molecular typing may be helpful adjuncts.

Am J Med, 1999 May 3, 106(5A), 2S - 10S; discussion 48S-52S
Methicillin-resistant Staphylococcus aureus: long-term care concerns; Bradley SF; Colonization of residents of long-term care facilities with methicillin-resistant Staphylococcus aureus (MRSA) is an important healthcare concern . MRSA colonization is prevalent; in two of the most common sites of colonization, nares and wounds, colonization rates range from 8% to 53%, and 30% to 82%, respectively . With such a large number of patients harboring the organism, it is imperative that long-term care facilities are knowledgeable regarding the overall significance of MRSA, are aware of MRSA infection rates at their facilities, and have established a threshold above which outbreak precautions will be instituted . More importantly, facilities must ensure that appropriate precautions (e.g., hand washing, glove changes, gowns) are utilized to prevent transmission of MRSA to noncolonized residents . If these basic measures are taken, MRSA-colonized residents of long-term facilities should be able to be fully integrated into the everyday activities within the long-term care environment . In the event of an outbreak of MRSA infection, stricter isolation of colonized and infected residents is warranted, and such isolation should be discontinued as soon as the chain of transmission has been disrupted . Systemic antibiotics should be avoided in asymptomatic colonized patients; topical antibiotics like mupirocin should be reserved for short-term administration in outbreak situations.

J Antibiot (Tokyo), 1999 Mar, 52(3), 269 - 75
Lactonamycin, a new antimicrobial antibiotic produced by Streptomyces rishiriensis MJ773-88K4 . I . Taxonomy, fermentation, isolation, physico-chemical properties and biological activities; Matsumoto N et al.; Lactonamycin (1) was isolated from a culture broth of Streptomyces rishiriensis MJ773-88K4 . Antibiotic 1 exhibited antimicrobial activities against Gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE).

J Antibiot (Tokyo), 1999 Feb, 52(2), 127 - 33
Time and concentration dependent influence of dirithromycin on neutrophils oxidative burst; Levert H et al.; Dirithromycin is a 14-membered macrolide antibiotic, well known to yield high intragranulocytic levels after several hour exposure . We chose therefore to investigate oxidative metabolism after prolonged incubation periods with neutrophils . Neutrophil generation of reactive oxygen species, represented by superoxide anion, was assessed after fMLP or Staphylococcus aureus-induced activation of the respiratory burst . Cellular uptake of the drug was assessed concurrently, in order to attempt a correlation with time-dependent modifications of the cellular oxidative status . For 1 hour exposure time, a pro-oxidant effect was reported for lower concentrations, achievable during therapeutic administration, whereas the highest ones promoted a potent anti-oxidant effect . After prolonged incubation times, the anti-oxidant effect alone was reported, with time-dependent modifications of IC50 values . These values could be correlated with intracellular accumulation of the drug . The anti-inflammatory activity reported here for high dirithromycin concentrations, could be nevertheless clinically relevant, since dirithromycin cellular uptake extends beyond 4 hours.

J Pediatr Orthop, 1999 May-Jun, 19(3), 413 - 6
Community-acquired methicillin-resistant Staphylococcus aureus: a cause of musculoskeletal sepsis in children; Gwynne-Jones DP et al.; Between August 1996 and August 1997, 130 children were admitted to our pediatric orthopaedic unit with Staphylococcus aureus musculoskeletal infection . Twenty-six of the 130 staphylococcal isolates were resistant to methicillin, an incidence of 20% . All but one of the infections, a femoral fixator-pin infection, were community-acquired . Twenty-two of the infections were superficial; however, there were four cases of deep musculoskeletal sepsis due to methicillin-resistant S . aureus . In areas where methicillin-resistant S . aureus is prevalent in the community, methicillin resistance should be considered in any overwhelming staphylococcal infection not responding to conventional antibiotics despite adequate surgical debridement.

Microb Pathog, 1999 Jun, 26(6), 317 - 23
Mechanisms of Staphylococcus aureus invasion of cultured osteoblasts; Ellington JK et al.; Staphylococcus aureus is a bacterial pathogen causing approximately 80% of all cases of human osteomyelitis . This bacterium can adhere to and become internalized by osteoblasts and previous studies indicate that osteoblasts are active in the internalization process . In the current study, we examined the roles of microfilaments, microtubules and clathrin-dependent receptor-mediated endocytosis in the internalization of S . aureus by MC3T3-E1 mouse osteoblast cells . Microfilament and microtubule polymerization was inhibited with cytochalasin D and colchicine . Clathrin-coated pit formation was examined by using the transaminase inhibitor, monodanslycadaverine . The results of this study indicate that mouse osteoblasts utilize actin microfilaments, microtubules and clathrin-coated pits in the internalization of S . aureus; however, microfilaments seem to play the most significant role in the invasion process .

Curr Microbiol, 1999 Jun, 38(6), 342 - 8
Superiority of 11,12 carbonate macrolide antibiotics as inhibitors of translation and 50S ribosomal subunit formation in Staphylococcus aureus cells; Champney WS et al.; Three pairs of related macrolide antibiotics, differing at the 11,12 position of the macrolactone ring, were compared for effects on growth rate, cell viability, protein synthesis, and 50S ribosomal subunit formation in Staphylococcus aureus cells . For each parameter measured, the 11,12 carbonate-derivatized compound was more inhibitory compared with the corresponding 11,12-hydroxy antibiotic . Substitution at the 3-position of the ring was also important in the relative inhibition observed . The degree of inhibition found in two different growth media was proportional to the generation time of the cells . Inhibition of both protein synthesis and 50S subunit formation by each drug correlated well with the inhibition of cell viability . The results indicate that closure of the 11,12-hydroxyl groups in macrolide antibiotics with a carbonate substitution generates a more effective antimicrobial agent.

Curr Eye Res, 1999 Mar, 18(3), 177 - 85
A comparison of the early inflammatory effects of an agr-/sar- versus a wild type strain of Staphylococcus aureus in a rat model of endophthalmitis; Giese MJ et al.; PURPOSE: We examined the ability of a wild type and an isogenic mutant strain of Staphylococcus aureus, deficient in the production of hemolysins and lipase (agr (-)/sar (-)), to induce endophthalmitis and inflammatory cell infiltration into the eye at 6, 24 and 48 hours after injection in a rat model of endophthalmitis . METHODS: Rat eyes were injected with 25 microl of viable S . aureus or sterile saline . Eyes were graded for clinical signs of inflammation daily, removed and processed for standard histologic analysis 6, 24 and 48 hours after injections . Comparisons of clinical scores and mean inflammatory cell numbers were made between S . aureus and control injected eyes . RESULTS: Both experimental groups developed clinical signs of endophthalmitis and demonstrated infiltration of inflammatory cells at 24 and 48 hours . Clinical inflammation in the Mutant I group was less than the wild type group at these times and significantly less at 48 hours (p<0.05) . No statistically significant difference in the number of inflammatory cells was detected between the wild type and Mutant I injected eyes at 24 hours . At 48 hours, inflammatory cells increased by 75.0% in the wild type group and decreased by 19.0% in the Mutant I group and a statistically significant difference was seen between these two groups (p<0.05) . At all times, the majority of inflammatory cells were neutrophils . By 48 hours, an increase in monocytes-macrophages was noted . CONCLUSION: Both strains of S . aureus induced clinical signs of inflammation and inflammatory cell infiltration . Clinical inflammation and inflammatory cell numbers were less in rats injected with the Mutant I strain . These results suggest that hemolysins and lipase may be important in the early induction phase of the inflammatory response.

J Dairy Sci, 1999 May, 82(5), 927 - 38
Possible risk factors associated with penicillin-resistant strains of Staphylococcus aureus from bovine subclinical mastitis in early lactation; Osteras O et al.; A randomized controlled field study of selective dry cow therapy with 686 cows allocated to two control groups (sampling only or placebo) or two therapy groups was used to screen for possible factors associated with penicillin-resistant strains of Staphylococcus aureus after the dry period . Therapy was given either as a total dose of 400,000 IU of penicillin and 100 mg of neomycin per infected quarter as dry cow preparation or as a total dose of 1.2 million IU of penicillin and 1200 mg of dihydrostreptomycin per infected quarter as a lactation formula . Success cows had all quarters identified as being free of penicillin-resistant strains of Staphylococcus aureus both at calving and at 30 +/- 17 d after calving . Failure cows were those having penicillin-resistant strains of Staph . aureus in any quarter at both or one of these two samples after the dry period . Using logistic regression, four variables were found to be associated with penicillin-resistant strains of Staph . aureus after the dry period . These included the identification of penicillin-resistant strains of Staph . aureus either at 45 +/- 32 d before drying off and at drying off, treatment for acute clinical mastitis at least once during the previous lactation, the weighted SCC of all cows' milk by daily milk yield within the herd, and therapy in the lactation formula compared with the two control groups . Our finding that the use of lactation formula increases the risk of resistance development is contradictory to present arguments underlying Norwegian dry cow therapy strategy.

Emerg Infect Dis, 1999 May-Jun, 5(3), 450 - 3
Fatal case due to methicillin-resistant Staphylococcus aureus small colony variants in an AIDS patient; Seifert H et al.; We describe the first known case of a fatal infection with small colony variants of methicillin-resistant Staphylococcus aureus in a patient with AIDS . Recovered from three blood cultures as well as from a deep hip abscess, these variants may have resulted from long-term antimicrobial therapy with trimethoprim/sulfamethoxazole for prophylaxis of Pneumocystis carinii pneumonia.

Am J Respir Cell Mol Biol, 1999 Jun, 20(6), 1303 - 9
Neutrophil emigration in the lungs, peritoneum, and skin does not require gelatinase B; Betsuyaku T et al.; Polymorphonuclear leukocytes (PMN) release gelatinase B in response to variable stimuli . Gelatinase B degrades basement membrane components in vitro, and inhibition of matrix metalloproteinase activity blunts PMN migration through a prototype basement membrane (Matrigel) and amnionic membranes . Accordingly, it has been speculated that gelatinase B is necessary for PMN emigration . To test this hypothesis we induced acute inflammation in the lungs, peritoneum, and skin in mice with a null mutation of the gelatinase B gene (gelatinase B-/-) and littermate controls (gelatinase B+/+) . At 3, 6, 12, and 24 h after intratracheal instillation of LPS, the emigration of PMN in the lung, as determined by PMN in bronchoalveolar lavage fluid, was similar in gelatinase B-/- and gelatinase B+/+ mice . The number of PMN in the peritoneal cavity 4 h after thioglycollate-induced peritonitis was also comparable in gelatinase B-/- and gelatinase B+/+ mice . At 4 h after an intradermal injection of interleukin-8, numerous PMN were present extravascularly in the dermis in both gelatinase B-/- and gelatinase B+/+ mice and the myeloperoxidase activities of the skin at the injection sites were indistinguishable between the two types of mice . PMN from gelatinase B-/- mice migrated through Matrigel in response to zymosan-activated serum with the same efficiency as did PMN from gelatinase B+/+ mice . In vitro, gelatinase B-/- PMN killed Staphylococcus aureus and Klebsiella pneumoniae as effectively as did PMN from gelatinase B+/+ mice . These findings indicate that gelatinase B is not required for PMN emigration, and suggest that the antibacterial function of PMN is preserved despite gelatinase B deficiency.

Jpn J Ophthalmol, 1999 Mar-Apr, 43(2), 69 - 74
Lectin cytochemistry of the lacrimal sac epithelium in experimental dacryocystitis; Maeda S et al.; PURPOSE: To study the glycoconjugates in the lacrimal sac epithelium of Japanese white rabbits with experimentally induced chronic dacryocystitis . METHODS: Chronic dacryocystitis was induced by a subcutaneous injection of albumin followed by an injection of Staphylococcus aureus into the lacrimal sac . The histological appearance of the lacrimal sac was studied using the alcian blue-periodic acid-Schiff sequence . In addition, the specific binding to the lacrimal sac epithelium of Ulex europaeus agglutinin 1, Ricinus communis agglutinin 1, peanut agglutinin, and soybean agglutinin was also studied . RESULTS: Staining with alcian blue-periodic acid-Schiff sequence showed hyperplasia of the goblet cells in the inflamed lacrimal sac epithelium . Lectin cytochemistry revealed specific binding of Ulex europaeus agglutinin 1, Ricinus communis agglutinin 1, peanut agglutinin, and soybean agglutinin to the lacrimal sac epithelium . CONCLUSIONS: These results indicated that the composition of glycoconjugates in the lacrimal sac epithelium is markedly changed in dacryocystitis . There seems to be a fundamental abnormality in glycoconjugate synthesis in the chronically inflamed lacrimal sac epithelium.

An Med Interna, 1999 Apr, 16(4), 171 - 4
{Left-sided endocarditis in patients with HIV infection}; Valencia Ortega ME et al.; BACKGROUND: Left-sided endocarditis in HIV-infected patients has an special clinical, epidemiological and microbiological characteristics and its relationship with drug addicts subjects is unknown . PATIENTS AND METHODS: Since 1986 up to 1996 we have been diagnosed 214 episodes of infective endocarditis in 190 HIV-infected patients . In 34 cases (15%) there was left-sided endocarditis . These patients are described . RESULTS: Mean age was 30 years and 28 were male (82%) . Thirty patients had been intravenous drug addicts (IVDA) but only 18 were active-IVDA . In three cases the endocarditis was nosocomial . Mean CD4+ lymphocyte count was 176 per mm3 and 59% were AIDS-patients . Tuberculosis was the most frequent opportunistic infection (14 cases) . The presentation was subacute in 70% and the most important symptom was fever . Only 3 (9%) had septic emboli in chest X-ray . The affected valve was mitral in 31 patients (91%) . The blood culture was negative in 21 episodes (62%) and only in 6, Staphylococcus aureus was isolated . The mortality was 18% and 68% were outcome without any problem . CONCLUSIONS: Left-sided endocarditis in patients with HIV infection is a very serious problem . It seems to affect to patients with severe immunosuppression and the culture blood may be negative . Its diagnosis is difficult and the mortality is elevated.

FEBS Lett, 1999 Apr 23, 449(2-3), 187 - 90
Comparison of synthesis and antibacterial activity of temporin A; Harjunpaa I et al.; Temporin A is a small, basic, highly hydrophobic, antibacterial peptide found in the skin of the European red frog, Rana temporaria . It was synthesized twice by the FastMoc solid phase method using amino acids protected at the N(alpha)-position with either 9-fluorenylmethoxycarbonyl or 2-(4-nitrophenylsulfonyl)ethoxycarbonyl . The syntheses of temporin A demonstrates the difference between 2-(4-nitrophenylsulfonyl)ethoxycarbonyl and 9-fluorenylmethoxycarbonyl amino acids . The purified peptide showed also antibacterial activity against clinically important gram-positive bacteria . It was found to have a moderately good activity against both methicillin resistant and sensitive strains of Staphylococcus aureus, but a weaker activity against vancomycin resistant strains of Enterococcus faecium.

Pediatr Dermatol, 1999 Mar-Apr, 16(2), 118 - 20
Eosinophilic pustular folliculitis in infancy: report of two new cases; Larralde M et al.; Eosinophilic pustular folliculitis (EPF) is a cutaneous inflammatory follicular disorder of unknown etiology . The diagnosis is made on the basis of clinical and histopathologic features . We describe two patients who had recurrent episodes of pruritic follicular papular and pustular lesions on the face, extremities, and trunk . The eruptions lasted for 1 month with intermittent remissions . Laboratory tests disclosed no infectious or parasitic etiology in patient 2 . In patient 1 we isolated methicillin-resistant Staphylococcus aureus in a blood culture . He had sepsis with lung and liver involvement . EPF is a self-limited dermatosis . On occasion, skin lesions may become superinfected, resulting in localized pyoderma or rarely systemic infection (sepsis) . Histologically both of our patients showed a moderate mixed inflammatory infiltrate with numerous eosinophils centered around hair follicles . Their lesions responded well to topical corticosteroids.

Drugs Exp Clin Res, 1999, 25(1), 13 - 21
Antagonistic effects of combination photosensitization by hypericin, meso-tetrahydroxyphenylchlorin (mTHPC) and photofrin II on Staphylococcus aureus; Kubin A et al.; Photodynamic therapy involves the application of a photosensitizer activated by visible light to generate cytotoxic reactive oxygen . In addition to clinical investigations, in vitro studies concerning photodynamic potency of sensitizers as well as quantification of illumination procedures are necessary . In our investigation, the objective was to evaluate not only the effects of photosensitizer and light on Gram-positive Staphylococcus aureus, but also to investigate possible synergistic or antagonistic effects of these sensitizers . Therefore, we used hypericin, Photofrin II, porfimer sodium and meso-tetrahydroxyphenylchlorin (mTHPC) alone, as well as in combination . Log-phase cells of S . aureus exhibited a marked sensitivity to white thermal light irradiation in the presence of Photofrin II and mTHPC . However, hypericin caused a rather stimulated growth expressed in increased optical density (OD) and increase of total cell count (TCC) of the culture . Combination sensitization of S . aureus by Photofrin II and mTHPC with hypericin likewise caused a stimulation of bacterial growth . No synergistic effects were obtained by combination of Photofrin II and mTHPC; photoresponse of S . aureus was rather decreased by using combined porphyrins . In comparison, TCC and colony-forming units (CFU) were suppressed in the presence of mTHPC after an illumination procedure as well as in dark reactions . These effects were also obtained in the combination photosensitization by mTHPC and Photofrin II . In the presence the of hypericin, photodynamic effects of mTHPC and Photofrin II were inhibited . It was finally concluded that hypericin in our model is not a proper sensitizer for combination photo-sensitization due to antagonistic effects on photodynamic activity of mTHPC and Photofrin II.

Cornea, 1999 May, 18(3), 361 - 5
Staphylococcal infection under a LASIK flap; Webber SK et al.; PURPOSE: To report a staphylococcal infection under a laser in situ keratomileusis (LASIK) flap and to discuss the management of this rare and potentially devastating complication . METHODS: A patient was referred to our practice having had bilateral LASIK . She was found to have abscesses under the left corneal flap . Staphylococcus aureus was identified as the infecting organism by corneal scrape and treated with appropriate antibiotics . The cornea improved, and then the abscess recurred . The abscess was again scraped and intensive treatment reinstituted . RESULTS: After successful treatment, the patient recovered excellent visual acuity with only a minimal astigmatic error . CONCLUSION: The possible reasons for the apparent improvement and then recurrence of the abscess are discussed . The management of this case including the need for corneal scrape and antibiotic prophylaxis is discussed in relation to previously reported cases.

Zh Vopr Neirokhir Im N N Burdenko, 1999 Jan-Mar, (1), 28 - 30
{Meningioma with a peritumoral abscess}; Onopchenko EV et al.; The paper presents a rare case of meningioma associated with peritumoral abscess formed in a 63-year-old female undergone right nephrectomy for abscessed pyelonephritis and drainage of gluteal abscesses 3 months before admission . Brain computed tomography revealed a left frontotemporal heterogeneous mass lesion with margin contrast accumulation . At surgery, convexity meningioma with peritumoral abscess was totally removed . Hematogenous spread of Staphylococcus aureus is most likely to be responsible for peritumoral abscess . The paper also gives a review of literature and a brief account of the case.

Microb Drug Resist, 1999 Spring, 5(1), 1 - 7
The Staphylococcus aureus transposon Tn551: complete nucleotide sequence and transcriptional analysis of the expression of the erythromycin resistance gene; Wu SW et al.; The complete nucleotide sequence of Staphylococcus aureus transposon Tn551 was determined . The 5,266-bp sequence encoded five putative proteins . Comparison of the nucleotide sequence of Tn551 with that of the enterococcal transposon Tn917 showed that the two transposons were 99.8% identical and differed only at 11 positions along the entire sequence . The genetic organization of Tn551 was also identical to that of Tn917 . Northern analysis of RNA prepared from a staphylococcal strain bearing Tn551 displayed three erm-associated transcripts that were constitutively produced . Mapping of the 5' ends of the transcripts by primer extension suggested that the constitutive transcription of erm was initiated from a nucleotide located 5 bp downstream of ORF1 . A second set of three erythromycin-inducible transcripts was also detected and these showed a pattern similar to that described for Tn917 . A simple and rapid method is described for the use of the Tn551 sequence information in sequencing transposon-inactivated staphylococcal genes.

J Med Microbiol, 1999 Mar, 48(3), 303 - 7
Emergence of mupirocin resistance in multiresistant Staphylococcus aureus clinical isolates belonging to Brazilian epidemic clone III::B:A; Ramos RL et al.; Mupirocin is a topical antimicrobial agent that has been successfully used to eradicate methicillin-resistant Staphylococcus aureus from the anterior nares and other sites of patients and health care personnel . This report describes the acquisition of a novel mupirocin resistance gene (ileS) by an epidemic MRSA clone that is geographically widespread in Brazil.

J Med Microbiol, 1999 Mar, 48(3), 297 - 301
Subtyping of methicillin-resistant Staphylococcus aureus isolates from the North-West of England: a comparison of standardised pulsed-field gel electrophoresis with bacteriophage typing including an inter-laboratory reproducibility study; Walker J et al.; Bacteriophage typing is currently the recognised methodology for the typing of methicillin-resistant Staphylococcus aureus (MRSA) in the UK . Bacteriophage typing is less discriminatory and does not type all isolates compared with some molecular methods for typing MRSA . Chromosomal genotyping by pulsed-field gel electrophoresis (PFGE) is increasingly recognised as an improved method for typing MRSA, providing increased discrimination and typability . In this study the results of a comparison of bacteriophage typing and PFGE typing and subtyping are presented for a large collection of isolates from the North-West of England . Isolates belonging to the most frequently isolated epidemic methicillin-resistant Staphylococcus aureus (EMRSA) bacteriophage types 15 and 16 were typed by PFGE with further discrimination of common PFGE types possible into a number of subtypes . These results for a large collection of isolates demonstrate the improved typing of MRSA with PFGE . The widespread acceptance of PFGE for typing MRSA isolates has been hampered by the lack of standardised methodologies . Recently, a standardised PFGE strain typing system, known as the GenePath system has become available . The results of an inter-laboratory comparison of PFGE typing for a collection of isolates demonstrated good reproducibility with this system.

Mil Med, 1999 May, 164(5), 353 - 7
Arthroplasty after war injuries to major joints; Haspl M et al.; From 1992 to 1995, replacement of the joint with an endoprosthesis after serious wounding and major destruction of joint elements was performed in 10 soldiers . Arthroplasty was performed on five knees, three hips, and two shoulders . The age range of the wounded soldiers was 22 to 55 years (mean, 37.7 years) . Six soldiers suffered explosive injuries, and 4 were injured by gunfire . Time elapsed from the moment of wounding to the time of total joint replacement was 9 to 42 months . We decided on arthroplasty as the preferred treatment because of the presence of strong contractures and very painful movement . In 8 patients, the results of the treatment, based on a follow-up time of 36 to 48 months, were good . In 2 patients, early septic arthritis developed after arthroplasty of the knee with concomitant loosening of the endoprosthesis . Staphylococcus aureus was detected in both patients . In those 2 patients, therefore, arthrodesis of the knee with external fixation was performed.

J Allergy Clin Immunol, 1999 May, 103(5 Pt 1), 895 - 900
Staphylococcal toxic shock syndrome toxin-1 inhibits monocyte apoptosis; Bratton DL et al.; BACKGROUND: Chronic atopic dermatitis (AD) lesions are associated with colonization by exotoxin-producing Staphylococcus aureus . Evidence suggests that cytokine production in AD, particularly of GM-CSF, prolongs survival of both peripheral blood monocytes and dermal monocyte-macrophages, the predominate inflammatory cell in lesions caused by chronic AD . OBJECTIVE: We sought to determine whether the staphylococcal exotoxin, toxic shock syndrome toxin-1 (TSST-1), could stimulate prosurvival cytokine production in monocytes and thereby inhibit apoptosis . METHODS: Cultures of peripheral blood monocytes from normal donors and subjects with AD were incubated with various concentrations of TSST-1, and the incidence of apoptosis was assessed by examining cytospin preparations and the appearance of hypodiploid DNA in the flow cytometer . Culture supernatants were analyzed for GM-CSF, IL-1beta, and TNF-alpha by ELISA . RESULTS: TSST-1, in a concentration-dependent manner starting at 0.1 pg/mL, significantly inhibited monocyte apoptosis and resulted in the production of the prosurvival cytokines GM-CSF, IL-1beta, and TNF-alpha . In coculture conditions with conditioned media from TSST-1-stimulated monocytes, with or without neutralizing antibody to the various cytokines, the data show GM-CSF production was responsible for the inhibition of apoptosis . CONCLUSIONS: The data strongly suggest that staphylococcal exotoxins known to colonize skin lesions on patients with chronic AD may induce the production of GM-CSF, resulting in inhibition of monocyte-macrophage apoptosis, and thereby contribute to the chronicity of this inflammatory disease.

J Periodontol, 1999 Apr, 70(4), 370 - 4
Bacteriostatic effects of hyaluronic acid; Pirnazar P et al.; BACKGROUND: This investigation is one of a series of projects seeking to ascertain whether hyaluronic acid (HA) is therapeutically effective in tissue regeneration procedures . The rationale for these investigations is to test the hypothesis that HA can serve as a bioabsorbable carrier for other substrates as well as itself actively promote the regeneration of tissue . METHODS: In this paper, we report on the bacteriostatic and bactericidal properties of 3 molecular weight formulations of recombinant HA (low, 141 kD; medium, 757 kD; and high, 1,300 kD) on selected oral and non-oral microorganisms in the planktonic phase . Three concentrations of each HA formulation were screened, 0.5, 1.0, and 2.0 mg/ml, using a standard broth culture assay . RESULTS: Recombinant HA exerted varied bacteriostatic effects on all the bacterial strains tested depending on its molecular weight (MW) and concentration . The high concentrations of the medium MW HA had the greatest bacteriostatic effect, particularly on the Actinobacillus actinomycetemcomitans, Prevotella oris, Staphylococcus aureus, and Propionibacterium acnes strains . The 1.0 mg/ml concentration of high MW HA had the greatest overall bacteriostatic effect, inhibiting the growth of all 6 bacterial strains tested . Among the bacterial strains studied, HA was found to have no bactericidal effects, regardless of concentration or molecular weight . CONCLUSIONS: The results of this study suggest that HA in the MW range of 1,300 kD may prove beneficial in minimizing bacterial contamination of surgical wounds when used in guided tissue regeneration surgery.

Life Sci, 1999, 64(18), 1675 - 87
The release of bradykinin in bovine mastitis; Eshraghi HR et al.; The kinin peptides are released during inflammation and are amongst the most potent known mediators of vasodilatation, pain and oedema . Despite early reports of the presence of kinins in milk, no previous study has investigated the role of the kinin system in bovine mastitis . The present study indicated that mastitis was accompanied by raised levels of bradykinin (BK) in milk and the increased levels of BK correlated with the severity of mastitis . Raised BK levels in mastitic milk were not dependent on the presence of inflammatory cells, nor were they secondary to changes in blood levels of BK . In milk from sub-clinically inflamed quarters, BK was raised in those milks where Staphylococcus aureus (S . aureus) was isolated but not in those milks where no pathogen was isolated . Increasing S . aureus artificially, also caused an increase in the milk BK . Increases in milk BK were not restricted only to the mastitic quarters of the udder . In udders in which mastitis was detected in one or more quarters, BK increases were also detected in the apparently uninvolved quarters.

Indian J Med Sci, 1998 Dec, 52(12), 553 - 5
Incidence of post operative wound infection and their antibiogram in a teaching and referral hospital; Murthy R et al.; A total of 406 post-operative clean wounds were studied for the presence of sepsis and antibiogram of organisms were established . The over all post-operative sepsis rate was 13% (clinical) and 12% (bacteriological) . Staphylococcus aureus (32%) and Pseudomonas species (21%) were the commonest organisms recovered and Netilmycin, Cephaloridine and Norfloxacin were the most effective antibiotics against both Gram positive and negative infections . This study reflects the change in pattern of infecting bacterial flora in case of post operative wound infections and its antibiogram.

J Clin Microbiol, 1999 Jun, 37(6), 2047 - 50
Disk with high oxacillin content discriminates between methicillin-resistant and borderline methicillin-susceptible Staphylococcus aureus strains in disk diffusion assays using a low salt concentration; Petersson AC et al.; A separation between mecA+ strains of Staphylococcus aureus and strains lacking mecA was achieved by the disk diffusion assay and the agar dilution method, utilizing disks containing 5 microg of oxacillin and inocula of approximately 5 x 10(5) CFU/spot, respectively, provided that agar with 0 to 0.5% NaCl and incubation at 30 degrees C were employed . The 5-microg oxacillin disks clearly discriminated between borderline methicillin-susceptible and mecA+ strains . The oxacillin MICs were more affected by the inoculum density and salt concentration than were the methicillin MICs, and oxacillin MICs of 4 to 16 microg/ml were obtained for strains lacking mecA . Significantly higher levels of beta-lactamase production and reduced oxacillin susceptibilities were recorded for strains lacking mecA, in particular strains of phage group V, when agar with >/=2% NaCl was used than when agar with 0 to 0.5% NaCl was employed . The results indicate that the borderline methicillin-susceptible phenotype is a salt-dependent in vitro phenomenon of questionable clinical relevance.

J Clin Microbiol, 1999 Jun, 37(6), 1913 - 20
Detection of an archaic clone of Staphylococcus aureus with low-level resistance to methicillin in a pediatric hospital in Portugal and in international samples: relics of a formerly widely disseminated strain?
Sa-Leao R, Santos Sanches I, Dias D, Peres I, Barros RM, de Lencastre H.
Close to half of the 878 methicillin-resistant Staphylococcus aureus (MRSA) strains recovered between 1992 and 1997 from the pediatric hospital in Lisbon were bacteria in which antibiotic resistance was limited to beta-lactam antibiotics . The other half were multidrug resistant . The coexistence of MRSA with such unequal antibiotic resistance profiles prompted us to use molecular typing techniques for the characterization of the MRSA strains . Fifty-three strains chosen randomly were typed by a combination of genotypic methods . Over 90% of the MRSA strains belonged to two clones: the most frequent one, designated the "pediatric clone," was reminiscent of historically "early" MRSA: most isolates of this clone were only resistant to beta-lactam antimicrobials and remained susceptible to macrolides, quinolones, clindamycin, spectinomycin, and tetracycline . They showed heterogeneous and low-level resistance to methicillin (MIC, 1.5 to 6 microg/ml), carried the ClaI-mecA polymorph II, were free of the transposon Tn554, and showed macrorestriction pattern D (clonal type II::NH::D) . The second major clone was the internationally spread and multiresistant "Iberian" MRSA with homogeneous and high-level resistance to methicillin (MIC, >200 microg/ml) and clonal type I::E::A . Surprisingly, the multidrug-resistant and highly epidemic Iberian MRSA did not replace the much less resistant pediatric clone during the 6 years of surveillance . The pediatric clone was also identified among contemporary MRSA isolates from Poland, Argentina, The United States, and Colombia, and the overwhelming majority of these were also associated with pediatric settings . We propose that the pediatric MRSA strain represents a formerly widely spread archaic clone which survived in some epidemiological settings with relatively limited antimicrobial pressure.

J Clin Microbiol, 1999 Jun, 37(6), 1709 - 13
Controlled clinical comparison of bioMérieux VITAL and BACTEC NR-660 blood culture systems for detection of bacteremia and fungemia in adults; Wilson ML et al.; A total of 9,446 blood cultures were collected from adult patients at three university-affiliated hospitals . Of these, 8,943 cultures were received with both aerobic bottles filled adequately; 885 yielded 1,016 microorganisms, including 622 isolates (61%) that were the cause of sepsis, 337 isolates (33%) that were contaminants, and 57 isolates (6%) that were indeterminate as the cause of sepsis . With the exception of Staphylococcus aureus, which was recovered more often from VITAL aerobic bottles, more pathogenic microorganisms were recovered from BACTEC NR6 (aerobic) bottles than from VITAL aerobic bottles . Growth of pathogenic microorganisms was detected earlier in VITAL aerobic bottles . A total of 8,647 blood cultures were received with both anaerobic bottles filled adequately; 655 yielded 740 microorganisms, including 486 isolates (66%) that were the cause of sepsis, 215 isolates (29%) that were contaminants, and 39 isolates (6%) that were indeterminate as the cause of sepsis . More pathogenic microorganisms were recovered from VITAL anaerobic bottles than from BACTEC NR7 (anaerobic) bottles . Growth of pathogenic microorganisms was detected earlier in VITAL anaerobic bottles . In 8,500 sets all four bottles were received adequately filled . When paired aerobic and anaerobic bottle sets (systems) were compared, more pathogenic microorganisms (again with the exception of S . aureus) were recovered from the BACTEC system . For the 304 septic episodes (253 unimicrobial and 51 polymicrobial), significantly more were detected by the BACTEC system . We conclude that VITAL requires modification to improve recovery of pathogenic microorganisms to make it competitive with other commercially available blood culture systems.

Commun Dis Intell, 1999 Mar 18, 23(3), 69 - 73
Reduced susceptibility of Staphylococcus aureus to vancomycin--a review of current knowledge; Paterson DL; Antibiotic options for patients with methicillin resistant Staphylococcus aureus infections are severely limited . Unfortunately, infections with S . aureus with reduced susceptibility to vancomycin and teicoplanin have been recently reported for the first time . Commonly used laboratory methods for determining antibiotic susceptibility may be inadequate for detecting reduced susceptibility to vancomycin . Even though no confirmed cases have yet been detected in Australia, a high index of suspicion must be maintained for the occurrence of such organisms . Strategies for prevention of the spread of S . aureus with reduced susceptibility to vancomycin should be prepared by Australian hospitals prior to their first cases being identified . This article outlines the background to this developing issue and discusses laboratory methods and findings, with some current recommendations for diagnostic laboratories.

Crit Care Med, 1999 Apr, 27(4), 798 - 801
Head-injured patients who are nasal carriers of Staphylococcus aureus are at high risk for Staphylococcus aureus pneumonia; Campbell W et al.; OBJECTIVE: To determine if head-injured patients with premorbid nasal colonization with Staphylococcus aureus are at increased risk for S . aureus infection . DESIGN: Patients admitted over a 2-yr period were enrolled if they met the following criteria: Injury Severity Score > or = 9, intensive care unit (ICU) admission, hospitalization in another hospital < 24 hrs, no recent use of antibiotics . SETTING: Acute care trauma facility . PATIENTS: Any patient sustaining acute, blunt, or penetrating injury and meeting the enrollement criteria were eligible . INTERVENTIONS: Swab cultures of both internal nares were performed within 72 hrs of readmission and cultured for S . Aureus . Patients were prospectively monitored for S . Aureus infections until discharge . MEASUREMENTS AND MAIN RESULTS: Admission nasal cultures were positive (NC+) for S . aureus in 144 of the 776 patients cultured . Forty of the 144 NC+ patients had isolated head (37) or high cervical spine (3) injury, and 11 of that group (27.5%) developed S . aureus infections . The remaining 104 patients positive for S . aureus on admission had no head injury (74) or head combined with torso and extremity injuries (30) . S . aureus infection was diagnosed in 11 of the 104 patients (10.6%) . The difference in incidence of infections is significant (p <.01), as is the difference in incidence of pneumonia (20% vs . 3.8%, respectively {p <.01}) . Organisms causing pneumonia were often the same organisms isolated from the nares on admission . CONCLUSIONS: Nasal colonization with S . aureus at the time of severe head injury increases the risk of S . aureus pneumonia during hospitalization . Prophylactic measures against S . aureus pneumonia may help reduce the length and cost of hospitalization.

Ann Surg, 1999 May, 229(5), 651 - 60; discussion 660-1
Hemorrhage decreases macrophage inflammatory protein 2 and interleukin-6 release: a possible mechanism for increased wound infection; Angele MK et al.; OBJECTIVE: To determine whether alteration in wound exudate cell immune function occurs after trauma-hemorrhage . BACKGROUND: Although clinical and experimental studies indicate that the rate of wound infection is increased after trauma and hemorrhagic shock, the underlying mechanism for this increased susceptibility remains unknown . METHODS: Male C3H/HeN mice were subjected to a midline laparotomy and polyvinyl alcohol sponges were implanted subcutaneously in the abdominal wound before hemorrhage (35+/-5 mm Hg for 90 minutes and resuscitation) or sham operation . The wound exudate cells from the sponges were harvested on the first, third, and fifth postoperative day and cultured for 24 hours in the presence of lipopolysaccharide (10 microg/ml) or heat-killed Staphylococcus aureus . Interleukin (IL)-1beta, IL-6, monocyte chemotactic protein 1, macrophage inflammatory protein 2, and nitrite levels were determined in the supernatants . The distribution of macrophages and polymorphonuclear leukocytes was assessed in the sponge with and without in vivo injection of S . aureus . The phagocytic activity of isolated wound exudate cells was determined using fluorescent S . aureus . RESULTS: The composition of exudate cells was unaltered by hemorrhagic shock; however, in vivo injection of S . aureus significantly decreased the percentage of macrophages under such conditions . Wound exudate cell phagocytic activity and the release of IL-1beta, IL-6, monocyte chemotactic protein 1, and macrophage inflammatory protein 2 was decreased on the first postoperative day . The release of IL-1beta and IL-6 was also decreased on the third postoperative day in hemorrhaged mice . On the fifth postoperative day, wound exudate cell cytokine production was comparable to that in shams . CONCLUSIONS: Because most wound infections occur early after severe trauma, these results suggest that the dysfunction of wound exudate cells after hemorrhage might contribute to the increased incidence of wound infections . Therefore, attempts to enhance or restore wound cell immune function might be helpful for decreasing the incidence of wound infections in trauma victims.

Eur Arch Otorhinolaryngol, 1999, 256(3), 153 - 7
Evaluation of ozonated oxygen in an experimental animal model of osteomyelitis as a further treatment option for skull-base osteomyelitis; Steinhart H et al.; The standard treatment of chromic skull-base osteomyelitis is antibiotics and surgical removal of sequestrums . Hyperbaric oxygen therapy has been found to be a useful method for managing refractory cases of chronic osteomyelitis . Since a minimal blood supply is needed for hyperbaric oxygen therapy, chronic osteomyelitis can produce necrotic infected areas that are not nutrified and therefore not assessable for hyperbaric oxygen therapy . Ozone is known to be an oxidizing medium with a strong bactericidal effect . We investigated the influence of locally applied ozonated oxygen on the development of chronic osteomyelitis in an experimental animal model using the femur of the rabbit . The proximal sides of the femurs of 40 rabbits were prepared and a needle inserted into the intramedullary cavity . Osteomyelitis was induced with an infusion of Staphylococcus aureus and sodium morrhuate into the bone . The needle was left in a intramedular location . After a 4-week delay animals were randomly separated into treatment and control groups . The infected femur of treated animals was flushed three times a day with 20 ml of ozonated oxygen at an ozone concentration of 107 micrograms/ml O2 over periods of 2 or 4 weeks . Clinical, radiographic and microbiological findings were documented . Chronic osteomyelitis occurred in all animals . Ten rabbits were excluded from further study during the investigation because of excessive weight loss (> 15% of the original weight) . Bacterial cultures showed no significant reduction of S . aureus concentrations in the ozone-treated group, although comparison of radiographic results revealed less serious osteomyelitis-related bone damage in these animals (P < 0.01) . These findings indicate that refractory osteomyelitis in the head and neck may benefit from locally applied "flush" therapy with ozonated oxygen in addition to treatment with antibiotics, surgery and hyperbaric oxygen.

Anaesthesist, 1999 Mar, 48(3), 169 - 72
{Epidural abscess following a lumbar epidural catheter for mobilization of the knee}; Kranke W et al.; We report on a case of a lumbar epidural abscess with staphylococcus aureus following a catheter epidural anaesthesia in a previously healthy and not immunosuppressed 34-year-old female . The indication for the epidural anaesthesia was mobilization of the right knee following arthrotomy due to chronic synovitis . On postoperative day 7 the patient experienced lumbar pain, headache and meningism . Magnetic resonance imaging revealed an epidural abscess at the height of the 3rd and 4th lumbar vertebrae . A right-sided intralaminar fenestration with debridement and drainage of the abscess was carried out immediately after confirmation of the diagnosis . The patient was discharged from hospital on postoperative day 21 without any neurological sequelae . This is another addition to the published cases of epidural abscess following a epidural technique . It underlines the need for a proper aseptic technique, to abandon frequent changes of bacterial filters, daily examination of the entry site of the catheter and strategies for close and continuous monitoring of patients following epidural anaesthesia.

Br J Dermatol, 1999 Mar, 140(3), 518 - 20
Staphylococcal scalded skin syndrome in an adult associated with methicillin-resistant Staphylococcus aureus; Acland KM et al.; We report the first adult case of staphylococcal scalded skin syndrome (SSSS) due to methicillin-resistant Staphylococcus aureus (MRSA) . This case is particularly unusual as the MRSA produced toxic shock syndrome toxin 1 and enterotoxin, but not exfoliatoxin . SSSS was originally described in neonates and is thought to result from exfoliatins which produce subcorneal splitting of the epidermis and are only produced by certain strains of S . aureus . This case reflects the range of toxins that can be associated with SSSS and the clinical manifestations of MRSA infection in adult patients.

Br J Dermatol, 1999 Feb, 140(2), 328 - 33
Folliculitis decalvans including tufted folliculitis: clinical, histological and therapeutic findings; Powell JJ et al.; In a series of 18 patients with folliculitis decalvans attending the Oxford hair clinic, eight were found to have areas of tufted folliculitis either at presentation or follow-up . There was no difference between these two groups in their presentation, clinical course, growth of causative organism (Staphylococcus aureus) or investigations including histology . We suggest that these two entities form part of a spectrum of a single disease . We performed lymphocyte staining on affected scalp biopsies, including CD4: CD8 and T-cell/B-cell ratios, but found no evidence of local immune suppression or failure which would explain the abnormal host response to a common pathogen in this rare condition . We introduced a new treatment regimen for these patients, oral rifampicin and oral clindamycin together for 10 weeks . Ten of the 18 patients have responded well with no evidence of recurrence 2-22 months after one course of treatment, and 15 of the 18 responded after two or three courses.

Immunology, 1999 Jan, 96(1), 90 - 7
Arachidonic acid, but not its metabolites, is essential for FcgammaR-stimulated intracellular killing of Staphylococcus aureus by human monocytes; Zheng L et al.; Since arachidonic acid (AA) production by phospholipase A2 (PLA2) is essential for the Fcgamma receptor (FcgammaR)-mediated respiratory burst and phagocytosis of opsonized erythrocytes by monocytes and macrophages, we focused in this study on the role of AA and its metabolites in the FcgammaR-stimulated intracellular killing of Staphylococcus aureus by human monocytes . The results revealed that the PLA2 inhibitors, but not inhibitors of cyclo-oxygenase and lipoxygenase, markedly suppressed the FcgammaR-mediated killing process . The production of O-2 by monocytes upon FcgammaR cross-linking was inhibited by 4-bromophenacyl bromide in a dose-dependent fashion, indicating that inhibition of PLA2 activity impairs the oxygen-dependent bactericidal mechanisms of monocytes, which could be partially restored by addition of exogenous AA and docosahexaenoic acid, but not myristic acid . These polyunsaturated fatty acids, but not myristic acid, stimulated the intracellular killing of S . aureus by monocytes, although not as effectively as FcgammaR cross-linking . Furthermore, FcgammaR cross-linking stimulated the release of AA from monocytes . Studies with selective inhibitors revealed that the FcgammaR-mediated activation of PLA2 is dependent on Ca2+ and tyrosine kinase activity . Together these results indicate a key role for PLA2/AA, but not its major metabolites, in mediating the FcgammaR-stimulated intracellular killing of S . aureus by monocytes.

Clin Exp Dermatol, 1998 Nov, 23(6), 249 - 53
An outbreak of methicillin-resistant staphylococcus aureus (MRSA) in a dermatology day-care unit; Farrell AM et al.; We describe an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) in a dermatology day-care unit and the methods used to determine the mechanism of spread and control it . The epidemic strain had a characteristic sensitivity pattern and was typeable with phages 29, 80, 95, 47, 54 and 77, which was of considerable value in interpreting the epidemiological data . The method of spread was studied by examination of the medical and nursing records of patients who had acquired MRSA (to determine which members of staff they had encountered and which other MRSA-positive patients had been present in the department at the same time) and by the microbiological screening of all patients and staff . However, screening of all staff by nasal swabbing failed to identify carriage of the epidemic strain, while extensive swabbing of surfaces on the day-care unit also failed to show any evidence of MRSA in the environment . This suggests that the MRSA was most probably spread from patient to patient via the hands of staff, although there was also the possibility of direct transmission from patient to patient . Nine patients acquired the unique strain of MRSA and once acquired it proved difficult to eradicate, although in the majority, the infection did not appear to be clinically significant . However, in two patients MRSA contributed to a fatal outcome: these were the two most elderly patients and were the only two who were receiving systemic corticosteroids . The outbreak was brought under control with rigorous hygienic measures and the decision to discharge all patients with MRSA from the day-care unit . Repeat screening (swabs of nose, axilla and groin) of all day-care unit and in-patients 11 months after the last MRSA case showed no evidence of any residual MRSA infection in the day-care unit.

Rev Alerg Mex, 1999 Jan-Feb, 46(1), 3 - 7
{use of a Staphylococcus bacterial vaccine in pediatric patients with chronic sinusitis}; Martinez Perez A et al.; INTRODUCTION: The antigenic extracts of bacterial vaccine (Staphylococcus aureus) they increase the phagocitosis, the immunoglobulins concentrations and they help in the immunologic response . OBJECTIVE: To determine the effectiveness of the bacterial vaccine in patient pediatric with chronic sinusitis . MATERIAL AND METHOD: Through a prospective, observational, descriptive and logitudinal study 50 patients were studied with clinical and radiological diagnosis of chronic sinusitis in the period of May from 1997 to July of 1998; they talked to three outlines of antibiotics, they were made studies of cytology hematic, of snot, perspired pharyngeal and immunoglobulin determination and x-rays of breasts paranasals . The extract of 0.1 ml was applied twice up to 0.5 ml per week, subcutaneous trial during eight months, with pursuit of six months and control of cytology hematic, as well as immunoglobulin determination . RESULTS: 82% (41) of the patients they improved and nine (18%) they persisted with symptoms, of these five required the antimicrobials prescription, three tonsillectomi . There was an immunoglobulin increment, mainly of the IgA and IgG in 38 (76%) patient.

J Pharm Sci, 1999 May, 88(5), 510 - 4
A novel microbial infection-responsive drug release system; Tanihara M et al.; The aim of this study was to construct a novel drug delivery system suitable for controlled release of antibiotics . There is a need for devices that release antibiotics only during microbial infection, because prophylactic or prolonged use of antibiotics leads to serious problems, such as renal and liver toxicity and the emergence of drug-resistant bacteria (e.g., meticillin-resistant Staphylococcusaureus) . We found previously that Staphylococcus aureus-infected wound fluid showed high thrombin-like activity; therefore, in this study we designed an antibiotic release system triggered by thrombin activity . We synthesized an insoluble polymer-drug conjugate in which gentamicin was bound to poly(vinyl alcohol) hydrogel through a newly developed thrombin-sensitive peptide linker . The conjugate released gentamicin when it was incubated with Staphylococcus aureus-infected wound fluid, with thrombin and leucine aminopeptidase, or with human plasma and Ca2+, whereas no biologically active gentamicin was released when the conjugate was incubated with noninfected wound fluid, with leucine aminopeptidase alone, with thrombin alone, or with plasma . Furthermore, the conjugate reduced the bacterial number in an animal model of Staphylococcus aureus infection . These results demonstrated that the conjugate has sufficient specificity and excellent potential as a stimulus-responsive, controlled drug release system.

Eur J Biochem, 1999 May, 262(1), 166 - 75
Controlled cleavage of KLH1 and KLH2 by the V8 protease from Staphylococcus aureus reassociation, electrophoretic and transmission electron microscopy study of peptide fragments; Gebauer W et al.; The reassociation behaviour of protease V8-cleaved peptides from KLH1 and KLH2, the two hemocyanin isoforms from the giant keyhole limpet Megathura crenulata, has been studied by transmission electron microscopy of negatively stained specimens and SDS/PAGE . Reassociation of the complete mixture of protease cleavage products and of combinations of peptide fragments purified by HPLC was performed in the presence of 100 mm CaCl2 and 100 mm MgCl2 at pH 7.4, over a period of 1 to 4 weeks . The V8 protease splits KLH1 into peptide fragments containing the functional units abc, def, defg, defgh, g and h . This mixture of peptide fragments reassociated to form helical tubular polymers, with a diameter of approximately 25 nm . The single functional units g and h were not incorporated into the polymer . An essentially identical polymer was formed from the re-mixed HPLC-purified fragments abc, def and defg alone . As with uncleaved subunit, the tubular polymer of V8-cleaved KLH1 forms bundles . The combination of peptides def and defg led to the formation of short arc-like filamentous structures, which aggregated but showed little tendency to associate into larger polymers . The KLH1 peptide fragments abc and def alone, did not reassociate and in combination their potential to form polymers was very low . With KLH2, the V8 protease generated peptide fragments containing the functional units abc, defg, defgh and h, which in combination slowly reassociated to form a tubular polymer significantly different to that obtained from the KLH1 V8 fragments . The three-functional unit fragment abc from KLH2 showed no tendency to polymerize and the combination of peptides defg + defgh generated only disordered aggregates, with some indication of malformed tubules . The combination of biochemical and electron microscopical methods enabled the characterization of these polymers with respect to peptide composition and higher order structure.

APMIS, 1999 Apr, 107(4), 425 - 30
Frequency of alpha- and beta-haemolysin in Staphylococcus aureus of bovine and human origin . A comparison between pheno- and genotype and variation in phenotypic expression; Aarestrup FM et al.; The phenotypic expression of haemolysins and the presence of genes encoding alpha and beta-haemolysin were determined in 105 Staphylococcus aureus isolates from bovine mastitis, 100 isolates from the nostrils of healthy humans, and 60 isolates from septicaemia in humans . Furthermore, the possible change in expression of haemolysins after subcultivation in human and bovine blood and milk was studied in selected isolates . Alpha-haemolysin was expressed phenotypically in 39 (37%) of the bovine isolates, in 59 (59%) of the human carrier isolates, and in 40 (67%) of the isolates from septicaemia . Beta-haemolysin was expressed in 76 (72%) bovine, 11 (11%) carrier, and 8 (13%) septicaemia isolates . Significantly more bovine than human isolates expressed beta-haemolysin and significantly fewer expressed alpha-haemolysin . Genotypically, the gene encoding alpha-haemolysin was detected in all isolates . A significant difference in the prevalence of the gene encoding beta-haemolysin between the bovine (96%), human carrier (56%) and isolates from septicaemia (57%) was found . Of the bovine isolates, 75% of those carrying the gene encoding beta-haemolysin expressed beta-haemolysin phenotypically, whereas only 20% of the carrier isolates and 24% of the septicaemia isolates did so . No change in expression of haemolysins could be observed after subcultivation of bovine isolates in human blood and milk . After 5 to 10 subcultures in bovine blood and 1 to 4 in bovine milk, 9 of 10 human isolates originally phenotypically beta-haemolysin negative initiated the expression of beta-haemolysin . This study showed that a larger proportion of S . aureus of bovine origin carry the beta-haemolysin gene compared to isolates from humans . Furthermore, a larger number of the isolates of bovine origin carrying the beta-haemolysin gene express this gene phenotypically compared to isolates of human origin.

Bioorg Med Chem Lett, 1999 Apr 5, 9(7), 1023 - 8
Analogues of 4,5-bis(3,5-dichlorophenyl)-2-trifluoromethyl-1H-imidazole as potential antibacterial agents; Antolini M et al.; A preliminary exploration of analogues of 4,5-bis(3,5-dichlorophenyl)-2-trifluoromethyl-1H-imidazole, 1, as novel antibacterial agents was carried out to determine the basic features of the structure responsible for the observed biological activity . The presence of two aryl rings, the imidazole NH and either a good electron withdrawing group or an aldehyde or amino group at C-2 were required for good levels of activity against methicillin resistant Staphylococcus aureus (MRSA).

Eur J Immunol, 1999 Apr, 29(4), 1397 - 405
The role of IL-4 in the staphylococcal enterotoxin B-triggered immune response: increased susceptibility to shock and deletion of CD8Vbeta8+ T cells in IL-4 knockout mice; Aroeira LS et al.; Administration of superantigens in vivo triggers responding T cells into clonal expansion and subsequent activation of the programmed cell death pathway, as well as into anergy . We examined the possibility that Th1 cytokines are involved in rescue from superantigen-induced programmed cell death and prevention of anergy by studying the Staphylococcus aureus enterotoxin B (SEB) immune response in mice in which the IL-4 gene was deleted (IL-4-/-) . In these mice, Th1 cell activation triggers increased IFN-gamma and reduced IL-5 production as compared to IL-4+/+ mice . The primary anti-SEB antibody response in IL-4-/- mice is thus dominated by immunoglobulins of the IgG2a isotype, whereas the IgG1 isotype prevails in IL-4+/+ mice . Our results also show that, in contrast to expectations, IL4-/- mice are more susceptible to SEB plus low-dose D-galactosamine-induced shock and that this response is TNF-alpha-dependent . In vivo treatment induces partial deletion and anergy of remaining SEB-reactive T cells . During the SEB-induced response, CD4Vbeta8+ T cells are deleted in IL-4-/- mice, but not in IL-4+/+ mice, suggesting a function for IL-4 in CD8+ T cell rescue from apoptosis . We show that IL-4 efficiently protects CD8+ T cells from in vitro starvation-induced apoptosis, and conclude that IL-4 has an important role in Th1 immune response regulation.

J Med Microbiol, 1999 May, 48(5), 495 - 9
Lectin typing of methicillin-resistant Staphylococcus aureus; Munoz A et al.; This study reports the patterns of agglutination of 77 clinical isolates of methicillin-resistant Staphylococcus aureus by 32 commercially available lectins . Cell suspensions were not pre-treated . Each isolate was cultured on three media: Columbia blood agar, trypticase-soy agar and Chapman Stone agar . The lectins agglutinating each isolate varied widely depending on culture medium; only five isolates were agglutinated by the same set of lectins regardless of the culture medium used . Lectin typing could be a useful epidemiological tool, but it is necessary to standardise assay conditions (notably culture medium) to enable meaningful comparison of the results produced by different research groups or centres.

Am J Respir Crit Care Med, 1999 May, 159(5 Pt 1), 1377 - 82
G-CSF during Escherichia coli versus Staphylococcus aureus pneumonia in rats has fundamentally different and opposite effects; Karzai W et al.; We investigated if bacteria type alters outcome with prophylactic granulocyte colony stimulating factor (G-CSF) therapy during pneumonia . Rats received G-CSF or placebo daily for 6 d and after the third dose were intrabronchially inoculated with either Escherichia coli or Staphylococcus aureus . Without G-CSF, E . coli and S . aureus produced similar (p = NS) mortality rates (36 versus 38%) and serial changes in mean circulating neutrophil counts (CNC), but differing mean (+/- SE) tumor necrosis factor (TNF) levels (E . coli, 259 +/- 104 versus S . aureus, 51 +/- 17 pg/ml, p = 0.01) . G-CSF prior to bacteria increased mean CNC more than six times compared with placebo (p = 0.001) . However, with G-CSF in the first 6 h after E . coli, there was a greater than 20-fold decrease in mean (+/- SE) CNC (x 10(3)/ mm3) to below placebo (0.5 +/- 0.1 versus 0.8 +/- 0.1), whereas with G-CSF after S . aureus, there was only a fivefold decrease in mean CNC and CNC were greater than placebo (1.8 +/- 0.2 versus 0.8 +/- 0.1) (E . coli versus S . aureus decrease in CNC with G-CSF, p = 0.001) . With E . coli, G-CSF worsened oxygenation and increased bacteremia and mortality, whereas with S . aureus, G-CSF improved oxygenation and decreased bacteremia and mortality (G-CSF therapy, E . coli versus S . aureus, p = 0.03, 0.05, and 0.001, respectively) . Thus, during S . aureus pneumonia with low TNF levels, G-CSF increased CNC and bacterial clearance, resulting in less pulmonary injury and decreased death . During E . coli pneumonia with high TNF levels, G-CSF paradoxically decreased CNC, resulting in impaired bacterial clearance and worsened pulmonary injury and death . Bacterial species and the associated inflammatory mediator response can alter outcome with prophylactic G-CSF therapy during pneumonia.

Clin Immunol, 1999 May, 91(2), 226 - 33
Synergistic inhibition of human B cell activation by gold sodium thiomalate and auranofin; Hirohata S et al.; The mechanism of action of gold compounds, which are effective in the treatment of rheumatoid arthritis (RA), has not been clearly identified . Since one of the characteristic features of RA is chronic stimulation of B cells, the current studies compared the effects of parenteral gold (gold sodium thiomalate; GST) and orally active gold (auranofin; AUR) on human B cells . IgM production was induced from highly purified B cells obtained from healthy donors by stimulation with Staphylococcus aureus Cowan I (SA) plus IL-2 . T cell proliferation and IFN-gamma production was induced from highly purified T cells by stimulation with immobilized mAb to CD3 . AUR as well as GST suppressed B cell IgM production at much lower concentrations than those that suppressed T cell proliferation or IFN-gamma production . Thus, as little as 0.01 microg/ml AUR (0.015 microM) markedly suppressed IgM production, but neither T cell proliferation nor IFN-gamma production . AUR as well as GST is required at the initiation of cultures to exert optimal suppressive effects on IgM production . Moreover, AUR as well as GST suppressed the expression of CD98 and CD71 on SA-stimulated B cells . Of note, AUR and GST exerted a synergistic inhibitory effect on B cell production of IgM and IgG in a manner which was reversed by catalase, but not by ascorbate . The synergistic inhibitory effect is most likely to be due to thiomalate components of GST, since AUR and thiomalate exerted comparable synergistic inhibitory effects on B cell function . Finally, AUR and bucillamine, another antirheumatic drug with thiol groups, also showed synergistic inhibition of B cell function . These results indicate that AUR and GST preferentially inhibit the function of B cells by interfering with the initial activation of B cells . More importantly, the data indicate that AUR synergizes with GST or thiols to inhibit B cell function in a manner that depends upon the generation of hydrogen peroxide . These synergistic inhibitory effects of AUR and compounds with thiols on in vitro human B cell activation suggest the therapeutic efficacy of combinations of these compounds in RA .

Ther Apher, 1998 Nov, 2(4), 300 - 4
The efficacy of therapeutic plasmapheresis for the treatment of fatal hemophagocytic syndrome: two case reports; Matsumoto Y et al.; A potentially fatal hemophagocytic syndrome (HPS) has been noted in patients with reactive HPS . We describe 2 patients with reactive HPS treated with a regimen of therapeutic plasmapheresis and evaluate the efficacy of plasmapheresis for fatal HPS . Case 1 was a 31 year-old woman who had been treated for systemic lupus erythematosus (SLE) with corticosteroid hormones and immunosuppressants . She presented with persistent leukopenia and thrombocytopenia with spiking fever . She had an elevated level of serum ferritin, liver dysfunction, coagulopathy, and plasma inflammatory cytokines . Her bone marrow smear disclosed numerous hemophagocytosis of histiocytes . She was administered therapeutic plasmapheresis with total plasma exchange by fresh frozen plasma . There was an immediate and prominent decrease of cytokines, and she completely recovered . Case 2 was a 34 year-old woman who had been receiving high doses of corticosteroids and plasmapheresis for severe Stevens-Johnson's syndrome . After 18 months, she presented with physical and laboratory findings resembling lupus-like conditions and was administered high doses of corticosteroids and immunosuppressants . Human parvovirus B19 infection was detected by IgM and IgG antibodies and viral DNA from a bone marrow sample; moreover, a bone marrow smear disclosed findings of HPS . Repeated therapeutic plasmapheresis was effective for improving her symptoms and laboratory abnormalities; however, she suffered from septic methicilline resistant staphylococcus aureus infection and finally died of a brain hemorrhage resulting from disseminated intravascular coagulation (DIC).

FEMS Microbiol Lett, 1999 Apr 15, 173(2), 279 - 84
Staphylococcus aureus adhesion to bone matrix and bone-associated biomaterials; Hudson MC et al.; Staphylococcus aureus is a frequent cause of orthopedic infections in humans . The bacterium expresses several adhesins that facilitate bacterial binding to the bone matrix and to bone implant biomaterials coated with host plasma constituents . The relevant S . aureus adhesins are termed microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) and specific MSCRAMMs are involved in bone and joint infections.

Biosci Biotechnol Biochem, 1999 Mar, 63(3), 588 - 90
An organosulfur compound isolated from oil-macerated garlic extract, and its antimicrobial effect; Yoshida H et al.; An organosulfur compound was isolated from oil-macerated garlic extract by silica gel column chromatography and preparative TLC . From the results of NMR, IR, and MS analyses, its structure was determined as E-4,5,9-trithiadeca-1,7-diene-9-oxide (iso-E-10-devinylajoene, iso-E-10-DA) . This compound was different from E-4,5,9-trithiadeca-1,6-diene-9-oxide (E-10-devinylajoene, E-10-DA) only in the position of a double bond . Iso-E-10-DA had antimicrobial activity against Gram-positive bacteria, such as Bacillus cereus, B . subtilis, and Staphylococcus aureus, and yeasts at the concentration lower than 100 micrograms/ml, but Gram-negative bacteria were not inhibited at the same concentration . The antimicrobial activity of iso-E-10-DA was inferior to those of similar oil-macerated garlic extract compounds such as E-ajoene, Z-ajoene, and Z-10-DA . From these results, it was suggested that trans structure and/or the position of double bond of iso-E-10-DA reduce the antimicrobial activity.

Liver Transpl Surg, 1999 May, 5(3), 238 - 45
Impaired leukocyte phagocytosis in patients undergoing hemihepatectomy for liver metastases; Wiezer MJ et al.; Patients undergoing partial hepatectomy have an increased susceptibility to infection . To investigate whether this increased risk is related to impaired leukocyte function, we studied polymorphonuclear leukocyte (PMN) phagocytosis in patients undergoing a hemihepatectomy because of liver metastasis (LM, n = 11) and in patients undergoing major abdominal surgery because of abdominal malignancy (AM, n = 8) . Eight healthy volunteers (HVs) served as controls . Leukocyte suspensions were incubated with fluorescein isothiocyanate-labeled Staphylococcus aureus, and phagocytosis was measured by flow cytometry . Preoperative PMN phagocytosis, in the presence of autologous plasma, was significantly less in patients with LM compared with patients with AM or HVs . This impaired phagocytosis was potentially restored in the presence of normal plasma . The decreased phagocytic capacity of PMNs from patients with LM was not related to levels of known plasma opsonins or phenotypic changes of PMNs . Rather, it was related to a deficiency of unidentified plasma factors . After surgery, the phagocytic capacity of PMNs of patients with AM decreased by approximately 30%, which correlated with decreasing levels of immunoglobulin G and C3 . In conclusion, patients with LM had a decreased PMN phagocytic capacity before surgery . This impairment in phagocytosis disappeared 1 week after surgery . We propose that the presence of LM leads to a deficiency of factor(s) in the blood that impairs PMN phagocytic capacity.

Int J Infect Dis, 1998-99 Winter, 3(2), 82 - 7
Molecular fingerprinting of mupirocin-resistant methicillin-resistant Staphylococcus aureus from a burn unit; Udo EE et al.; OBJECTIVES: To characterize mupirocin-resistant methicillin-resistant Staphylococcus aureus (MRSA) isolated from patients in a burn unit by pulsed-field gel electrophoresis and plasmid contents . METHODS: A total of 53 methicillin-resistant S . aureus, consisting of 48 mupirocin-resistant and 5 mupirocin-susceptible MRSA were compared by plasmid content and pulsed-field gel electrophoresis of Sma I digested genomic DNA . RESULTS: Of the 48 mupirocin-resistant isolates, 39 expressed high-level, and 9 expressed low-level mupirocin resistance . Plasmids were detected in all of the 53 isolates; however, only the high-level mupirocin-resistant isolates contained a 38 kb-conjugative plasmid that encoded high-level mupirocin resistance . Pulsed-field gel electrophoresis divided the isolates into four patterns designated types I to IV . Forty-three isolates consisting of 34 high-level, 5 low-level mupirocin-resistant and 4 mupirocin-susceptible isolates defined the type-I pattern . Eight isolates, five high-level and three low-level mupirocin-resistant isolates had the type-II pulsed-field pattern . The type-III and type-IV pulsed-field patterns consisted of a single isolate each . The type-I and type-II pulsed-field patterns were related and only differed by four Sma I bands . CONCLUSIONS: Results of typing the mupirocin-resistant MRSA from the burn unit with pulsed-field gel electrophoresis indicated that closely related MRSA clones previously circulating in the unit had acquired a high-level mupirocin-resistant plasmid, and spread aided by mupirocin use.

Infect Immun, 1999 May, 67(5), 2677 - 81
Mechanisms of internalization of Staphylococcus aureus by cultured human osteoblasts; Jevon M et al.; Staphylococcus aureus is an important bone pathogen, and evidence shows that this organism is internalized by chick osteoblasts . Here we report that S . aureus is internalized by human osteoblasts . Internalization was inhibited by monodansylcadaverine and cytochalasin D and to a lesser extent by ouabain, monensin, colchicine, and nocodazole . We propose that internalization occurs via a receptor-mediated pathway, requiring the participation of cytoskeletal elements, principally actin.

Infect Immun, 1999 May, 67(5), 2475 - 81
Membrane permeabilization by thrombin-induced platelet microbicidal protein 1 is modulated by transmembrane voltage polarity and magnitude; Koo SP et al.; Thrombin-induced platelet microbicidal protein 1 (tPMP-1) is a small, cationic peptide generated from rabbit platelets when they are exposed to thrombin in vitro . It has potent microbicidal activity against a broad spectrum of bacterial and fungal pathogens, including Staphylococcus aureus . Previous in vitro studies involving whole staphylococcal cells and planar lipid bilayers (as artificial bacterial membrane models) suggested that membrane permeabilization by tPMP-1 is voltage dependent (S.-P . Koo, M . R . Yeaman, and A . S . Bayer, Infect . Immun . 64:3758-3764, 1996; M . R . Yeaman, A . S . Bayer, S . P . Koo, W . Foss, and P . M . Sullam, J . Clin . Investig . 101:178-187, 1998) . Thus, the aims of the present study were to specifically characterize the electrophysiological events associated with membrane permeabilization by tPMP-1 by using artificial planar lipid bilayer membranes . We assessed the influence of transmembrane voltage polarity and magnitude on the initiation and modulation of tPMP-1 membrane permeabilization at various concentrations of tPMP-1 (range, 1 to 100 ng/ml) added to the cis side of the membranes . The incidence of membrane permeabilization induced by tPMP-1 at all of the concentrations tested was more frequent at -90 mV than at +90 mV . It is noteworthy that membrane permeabilization due to 1-ng/ml tPMP-1 was successfully initiated at -90 mV but not at +90 mV . Further, the mean onset times of induction of tPMP-1 activity were comparable under the various conditions . Modulation of ongoing membrane permeabilization was dependent on voltage and tPMP-1 concentration . Membrane permeabilization at a low tPMP-1 concentration (1 ng/ml) was directly correlated with trans-negative voltages, while a higher tPMP-1 concentration (100 ng/ml) induced conductance which was more dependent on trans-positive voltages . Collectively, these data indicate that the mechanism of tPMP-1 microbicidal activity at the bacterial cytoplasmic membrane may involve distinct induction and propagation stages of membrane permeabilization which, in turn, are modulated by transmembrane potential, as well as peptide concentration.

Infect Immun, 1999 May, 67(5), 2299 - 305
Antibacterial action of extracellular mammalian group IIA phospholipase A2 against grossly clumped Staphylococcus aureus; Dominiecki ME et al.; Fibrinogen-dependent interactions of Staphylococcus aureus are believed to contribute to bacterial virulence by promoting bacterial attachment to fibrinogen-coated surfaces and inducing the formation of bacterial clumps that are likely resistant to phagocytosis . Although S . aureus produces several fibrinogen-binding proteins, the cell wall-associated protein clumping factor (encoded by clfA) appears to be most important in bacterial interactions with immobilized or soluble purified fibrinogen . We have compared bacterial clumping in several strains of S . aureus, including isogenic ClfA+ and ClfA- Newman strains, in the presence of purified rabbit fibrinogen, human plasma, and inflammatory fluid and examined the effect of clumping on bacterial sensitivity to mammalian group IIA phospholipase A2 (PLA2) . This enzyme is the major extracellular bactericidal agent in inflammatory fluid active against S . aureus . Both ClfA-dependent and ClfA-independent bacterial clumping was observed, depending on the source and fibrinogen content of the biological fluid . In each case, clumping only partially reduced the antibacterial activity of PLA2, suggesting that this extracellular enzyme can substantially penetrate dense bacterial clumps . Bacterial clumps could be dispersed by added proteases, restoring full antibacterial activity to PLA2 . Thus, the extracellular mobilization of group IIA PLA2 during inflammation may provide a mechanism by which the host can control the proliferation and survival of S . aureus even after bacterial clumping.

Clin Diagn Lab Immunol, 1999 May, 6(3), 311 - 5
Recombinant human gamma interferon in human immunodeficiency virus-infected children: safety, CD4(+)-lymphocyte count, viral load, and neutrophil function (AIDS Clinical Trials Group Protocol 211); Shearer WT et al.; Nineteen children with human immunodeficiency virus (HIV) infection were treated with recombinant human gamma interferon (rIFN-gamma) (50 microg/m2 subcutaneously three times each week during weeks 1 through 12 and 100 microg/m2 subcutaneously three times each week during weeks 13 through 24) in a phase I/II clinical trial . All children continued to receive previously prescribed therapy with oral zidovudine or didanosine . Children were assessed clinically and with laboratory studies during 24 weeks of study treatment and for 12 weeks after completion of rIFN-gamma therapy . In general, rIFN-gamma therapy was well tolerated . There were two clinical or laboratory adverse events thought to be possibly or probably study drug associated . One child developed acute pancreatitis; another child developed granulocytopenia . Median CD4(+)-lymphocyte counts and plasma HIV RNA concentrations did not change significantly during therapy . In vitro neutrophil bactericidal activity against Staphylococcus aureus and superoxide production were not significantly affected by rIFN-gamma therapy . We conclude that rIFN-gamma therapy in HIV-infected children receiving single-agent antiretroviral therapy is safe and does not produce consistent changes in CD4(+)-lymphocyte count, plasma HIV RNA concentration, or in vitro neutrophil function.

Scand J Infect Dis, 1998, 30(6), 618 - 9
Intramedullary spinal cord abscess associated with cervical spondylodiskitis and epidural abscess; Derkinderen P et al.; A 50-year-old man presented a cervical vertebral osteomyelitis and epidural abscess due to Staphylococcus aureus . There were significant changes in the cervical region, as revealed by CT scan and MRI, leading to the diagnosis of associated intramedullary abscess of the spinal cord, which was confirmed by anatomopathological study.

Scand J Infect Dis, 1998, 30(6), 573 - 7
Acute osteomyelitis in children: a population-based retrospective study 1965 to 1994; Dahl LB et al.; OBJECTIVES: To investigate changes in occurrence, clinical features, laboratory and other investigations, aetiology and use of antibiotics, and to calculate the incidence of acute hematogenous osteomyelitis (AHO) in children up to 12 y of age in the county of Troms in the northern part of Norway . METHODS: Retrospective chart review of 86 children, newborn to 11 y old . with AHO between 1965 and 1994 . RESULTS: A constant yearly incidence (95% CI) of 0.1 (0.08-0.12) per 1000 children could be calculated (X2 for trend 0.51;p = 0.48) . The female proportion (95% CI) was 0.6 (0.48-0.72) . The median duration of complaints prior to admission was 4 days . Erythrocyte sedimentation rate (ESR; mean (95% CI)= 59 mm/h (52-66)) and C-reactive protein concentration (CRP; mean (95% CI)= 63 mg/l (36-90)) were elevated in 96% and 89%, respectively . Local and/or blood cultures were taken in 97% . In 55% an agent was found . Staphylococcus aureus (S . aureus) was responsible in 76% . The proportion of betalactamase-producing strains tended to increase (49%; X2 for trend 3.72; p = 0.054) . In 78% the long bones of the upper or lower extremities were affected . Penicillin or ampicillin combined with cloxacillin or dicloxacillin was the preferred therapy . The median duration of antibiotic treatment was 7 weeks . The use of penicillin declined (p = 0.008), whereas that of cloxacillin/dicloxacillin increased (p < 0.001) . The use of ampicillin was unchanged (p = 0.79) . CONCLUSION: The study confirms reports from various epochs and remote regions concerning the unchanged characteristics of AHO in children, except for the high proportion of females in the present study . An incidence for childhood AHO in a defined geographical region is given.

J Card Surg, 1998 Jul, 13(4), 252 - 9
Bloodstream, respiratory, and deep surgical wound infections after open heart surgery; Gol MK et al.; Nosocomial infections are one of the most feared complications after open heart surgery . A large retrospective study was conducted to evaluate the nature and scope of the problem . Between 1992 and 1998, 9352 patients who had undergone open heart surgery were evaluated . Bloodstream infections, pneumonia, and deep sternal wound infections were included . Univariate and logistic regression analyses were conducted to identify the high-risk patients that were likely to become infected . Three hundred forty-six infections in 276 patients were diagnosed . Age, preoperative albumin level, banked blood requirement, duration of operation, diabetes mellitus, previous open heart surgery, moderate or severe pericardial adhesions, obesity, postoperative low cardiac output, and postoperative cerebrovascular accident were found to be significant in univariate and logistic regression analyses for infectious outcome . Univariate analysis also revealed additional significant factors: fresh frozen plasma requirement, duration of cardiopulmonary bypass and cross-clamp, preoperative high levels of blood urea and glucose, presence of occlusive peripheral arterial disease, preoperative history of hypertension, and nasal carriage of Staphylococcus aureus . Methicillin resistant S . aureus was involved in 58.4% of the infections . Risk factors should be individualized for patients and every effort should be carried out to minimize infectious outcome.

J Exp Med, 1999 May 3, 189(9), 1497 - 506
Role of the scavenger receptor MARCO in alveolar macrophage binding of unopsonized environmental particles; Palecanda A et al.; Alveolar macrophages (AMs) avidly bind and ingest unopsonized environmental particles and bacteria through scavenger-type receptors (SRs) . AMs from mice with a genetic deletion of the major macrophage SR (types AI and AII; SR-/-) showed no decrease in particle binding compared with SR+/+ mice, suggesting that other SRs are involved . To identify these receptors, we generated a monoclonal antibody (mAb), PAL-1, that inhibits hamster AM binding of unopsonized particles (TiO2, Fe2O3, and latex beads; 66 +/- 5, 77 +/- 2, and 85 +/- 2% inhibition, respectively, measured by flow cytometry) . This antibody identifies a protein of approximately 70 kD on the AM surface (immunoprecipitation) that is expressed by AMs and other macrophages in situ . A cDNA clone encoding the mAb PAL-1-reactive protein isolated by means of COS cell expression was found to be 84 and 77% homologous to mouse and human scavenger receptor MARCO mRNA, respectively . Transfection of COS cells with MARCO cDNA conferred mAb-inhibitable TiO2 binding . Hamster MARCO also mediates AM binding of unopsonized bacteria (67 +/- 5 and 47 +/- 4% inhibition of Escherichia coli and Staphylococcus aureus binding by mAb PAL-1) . A polyclonal antibody to human MARCO identified the expected approximately 70-kD band on Western blots of lysates of normal bronchoalveolar lavage (BAL) cells (>90% AMs) and showed strong immunolabeling of human AMs in BAL cytocentrifuge preparations and within lung tissue specimens . In normal mouse AMs, the anti-MARCO mAb ED31 also showed immunoreactivity and inhibited binding of unopsonized particles (e.g., TiO2 approximately 40%) and bacteria . The novel function of binding unopsonized environmental dusts and pathogens suggests an important role for MARCO in the lungs' response to inhaled particles.

Antimicrob Agents Chemother, 1999 May, 43(5), 1111 - 7
In vitro antibacterial activities of platelet microbicidal protein and neutrophil defensin against Staphylococcus aureus are influenced by antibiotics differing in mechanism of action; Xiong YQ et al.; Thrombin-induced platelet microbicidal protein-1 (tPMP-1) and human neutrophil defensin-1 (HNP-1) are small, cationic antimicrobial peptides . These peptides exert potent in vitro microbicidal activity against a broad spectrum of human pathogens, including Staphylococcus aureus . Evidence suggests that tPMP-1 and HNP-1 target and disrupt the bacterial membrane . However, it is not yet clear whether membrane disruption itself is sufficient to kill the bacterium or whether subsequent, presumably intracellular, events are also involved in killing . We investigated the staphylocidal activities of tPMP-1 and HNP-1 in the presence or absence of pretreatment with antibiotics that differ in their mechanisms of action . The staphylocidal effects of tPMP-1 and HNP-1 on control cells (no antibiotic pretreatment) were rapid and concentration dependent . Pretreatment of S . aureus with either penicillin or vancomycin (bacterial cell wall synthesis inhibitors) significantly enhanced the anti-S . aureus effects of tPMP-1 compared with the effects against the respective control cells over the entire tPMP-1 concentration range tested (P < 0.05) . Similarly, S . aureus cells pretreated with these antibiotics were more susceptible to HNP-1 than control cells, although the difference in the effects against cells that received penicillin pretreatment did not reach statistical significance (P < 0.05 for cells that received vancomycin pretreatment versus effects against control cells) . Studies with isogenic pairs of strains with normal or deficient autolytic enzyme activities demonstrated that enhancement of S . aureus killing by cationic peptides and cell wall-active agents could not be ascribed to a predominant role of autolytic enzyme activation . Pretreatment of S . aureus cells with tetracycline, a 30S ribosomal subunit inhibitor, significantly decreased the staphylocidal effect of tPMP-1 over a wide peptide concentration range (0.16 to 1.25 microgram/ml) (P < 0.05) . Furthermore, pretreatment with novobiocin (an inhibitor of bacterial DNA gyrase subunit B) and with azithromycin, quinupristin, or dalfopristin (50S ribosomal subunit protein synthesis inhibitors) essentially blocked the S . aureus killing resulting from exposure to tPMP-1 or HNP-1 at most concentrations compared with the effects against the respective control cells (P < 0.05 for a tPMP-1 concentration range of 0.31 to 1.25 microgram/ml and for an HNP-1 concentration range of 6.25 to 50 microgram/ml) . These findings suggest that tPMP-1 and HNP-1 exert anti-S . aureus activities through mechanisms involving both the cell membrane and intracellular targets.

J Antimicrob Chemother, 1999 Mar, 43(3), 407 - 10
Extracellular and intracellular killing in neutrophil granulocytes of Staphylococcus aureus with rifampicin in combination with dicloxacillin or fusidic acid; Nielsen SL et al.; The effect of rifampicin in combination with dicloxacillin or fusidic acid on the extracellular and intracellular killing of Staphylococcus aureus in human neutrophil granulocytes in the presence of serum was studied . At the extracellular level rifampicin significantly reduced the bactericidal activity of dicloxacillin, but had an indifferent effect on the activity of fusidic acid . The combination of rifampicin with dicloxacillin or fusidic acid led to intracellular killing no different from that produced by rifampicin alone . However, owing to the high intracellular activity of rifampicin, the intracellular killing by the drug combinations was greater than that by dicloxacillin or fusidic acid alone.

J Clin Periodontol, 1999 Apr, 26(4), 206 - 11
Increased release of elastase from in vitro activated peripheral neutrophils in patients with adult periodontitis; Figueredo CM et al.; The main object of this study was to determine if there was a difference between patients with adult periodontitis and healthy controls in the release of elastase . We also wanted to test the release of alpha-1-antitrypsin and lactoferrin from in vitro-activated peripheral neutrophils . A leukocyte-rich preparation from venous blood was made by lysing the red blood cells . The leukocytes were stimulated for 1 h at 37 degrees C with opsonized Staphylococcus aureus and the released elastase was measured with a chromogenic substrate . The release of elastase after stimulation with bacteria was significantly higher in patients than in controls . The amounts of elastase from unstimulated cells, i.e., both released extracellularly and extracted from the pellet, were similar in the 2 groups . However, after stimulation, the amount of elastase in the patient group, but not in the control group, was significantly increased . Similar releases of alpha-1-antitrypsin (AIAT) and lactoferrin were found in both groups of subjects . In conclusion, this study shows that peripheral neutrophils from patients with adult periodontitis release more active elastase after in vitro activation compared to healthy controls . The release of A1AT and lactoferrin showed no differences, indicating that the increased elastase activity was not due to a impaired inhibition by A1AT and that the differences in degranulation were limited to the primary granula.

Med Dosw Mikrobiol, 1998, 50(3-4), 151 - 60
{Phagocytosis and killing of Staphylococcus aureus by granulocytes in mice after granulocyte-macrophage colony stimulating factor (GM-CSF) injection}; Czygier M et al.; GM-CSF is a hematopoietic growth factor . In vitro it stimulates the proliferation of myeloid progenitors and formation of granulocyte and macrophage colonies . It was found that GM-CSF in vitro is also stimulated the function of mature granulocytes, but we have no information about such influence in vivo . The purpose of this investigation was the evaluation in vivo of the GM-CSF effect on phagocytosis, bactericidal activity, and lysosome enzyme activities in granulocytes . GM-CSF was injected into mice subcutaneously during 5 consecutive days in the dose of 1 microgram/kg/d . The examination of the percent of cell phagocytizing bacteria (Staphylococcus aureus), NBT test, bactericidal activity and activation of acid phosphatase, alkaline phosphatase, peroxidase and esterase was performed every day and an evident increase of the tested parameters was found . These results prove in vivo activation of granulocytes by GM-CSF.

Med Dosw Mikrobiol, 1998, 50(3-4), 141 - 9
{Phagocytosis and killing of Staphylococcus aureus by mouse granulocytes after interleukin-3 (IL-3) injection}; Czygier M et al.; Interleukin-3 is a multipotential hematopoietic growth factor, which like other colony stimulating factors (CSFs) is effective "in vitro" stimulation of the mature cells function . It was found that IL-3 synergistically with GM-CSF and G-CSF stimulated the proliferation of the granulocytes . Therefore the purpose of this investigation was the evaluation "in vivo" of the influence of IL-3 on the phagocytosis, bactericidal activity, and enzyme activities of granulocytes . IL-3 was injected into mice subcutaneously during 5 days in dose 1 microgram/kg/d . The examination of the percent of cells phagocytizing bacteria (Staphylococcus aureus), NBT test and bactericidal activity, were performed every day and evident increase of the tested parameters was found . Additionally the enzyme activities in primary granules were measured and showed on increase of acid phosphatase and peroxidase activity.

Kansenshogaku Zasshi, 1999 Mar, 73(3), 225 - 32
Molecular typing of methicillin-resistant Staphylococcus aureus in a university teaching hospital; Ishimoto T et al.; Plasmid analysis and pulsed-field gel electrophoresis (PFGE) were used to study the epidemiologic relationship among methicillin-resistant Staphylococcus aureus (MRSA) strains isolated at Tokyo Medical and Dental University Hospital . We found that 263 of 276 MRSA isolates had plasmids, which could be classified into 30 different patterns according to the number and plasmid molecular weight . Strains which harboured a single plasmid of approximately 13.4 Mds in molecular weight were the most numerous (55.7% of the isolates) . These strains were isolated from 14 of 17 hospital wards . The largest number of strains with this plasmid pattern (33 strains) were isolated from a single ward . PFGE typing was then performed to further confirm the relationships among these 33 strains . The PFGE banding patterns of these strains were highly similar . The antibiogram profiles of these strains were also correlated with the PFGE pattern . Thus, the results suggest that these strains are epidemiologically related and spread throughout the ward . Combined plasmid analysis and PFGE were effective for discriminating the various MRSA isolates.

Biochem Biophys Res Commun, 1999 Apr 29, 258(1), 141 - 7
A minimized Fc binding peptide from protein A induces immunocyte proliferation and evokes Th1-type response in mice; Sinha P et al.; It is now well established that PA is a potent biological response modifier, showing simultaneously antitumor, antitoxic, anticarcinogenic, antifungal, antiparasitic and immunomodulatory properties . Since PA is a foreign protein, it is quite logical to assume that it may be cleaved into smaller peptide fragments in vivo which may be responsible for biological activities of whole PA molecule . The present study was undertaken to dissect out the structural entities of PA responsible for its biological properties . Protein A (PA) of Staphylococcus aureus has a unique property of binding with immunoglobulins . On the basis of molecular modeling and energy minimization studies a 20-mer tryptic fragment (theoretical) was predicted to retain IgG binding capacity which has been verified by immunoblot . This peptide sequence was selected to carry out experimental studies to show its functional mimicry of PA . We observed in the sera of 20-mer peptide treated mice that the concentrations of IFNgamma, TNFalpha and IL1alpha increase to a peak level by 4 h; on the other hand, there was a decrease in IL4, IL6 and IL10 concentrations at the same time (4 h) . The ratio of IFNgamma to IL4 showed Th1 type of response with the peptide as well as with that of PA . The nitric oxide concentration in sera also increases and the peak increase was in 6 h with both the peptide and PA . Cell cycle analysis using FACS shows that 20 micrograms dose of peptide was non-toxic to thymocytes and spleenocytes; on the other hand, it was immunoproliferative, shifting the thymocytes and spleenocytes from G0/G1 to S phase of the cell cycle . Further studies are in progress to evaluate other biological properties of the peptide, to evaluate if this peptide could be used as a substitute of PA to mimic at least some of its biological activities .

Cell Immunol, 1999 May 1, 193(2), 147 - 54
Unresponsiveness of peripheral T cells induced by apoptotic bodies derived from autologous T cells; Nakamura K et al.; Several reports described the dose-dependent effect of Staphylococcus aureus enterotoxin B (SEB) regarding both levels of apoptosis and anergy of T cells . We investigated here whether T-cell apoptosis induced with SEB causes unresponsiveness of naive T cells . Apoptotic bodies were isolated from human T cells stimulated with antigen-presenting cells (APCs) and SEB by the continuous density gradient centrifugation method . When naive T cells were stimulated with APCs and SEB in the presence of apoptotic bodies, their proliferation was dose dependently suppressed and their TCRs were less downregulated than those of T cells stimulated without apoptotic bodies . Furthermore, those T cells were predisposed not to respond to restimulation with fresh APCs and SEB in the absence of apoptotic bodies . These results, taken together with the observation of tight binding of apoptotic bodies to APCs, imply that T cells stimulated in the presence of apoptotic bodies may undergo unresponsiveness due to interruption of contact with APCs .

Int J Antimicrob Agents, 1999 Feb, 11(2), 159 - 61
Beneficial effect of combination antiplatelet therapy on the development of experimental Staphylococcus aureus endocarditis; Nicolau DP et al.; Previous studies in our laboratory have shown that antiplatelet agents, aspirin and ticlopidine, in clinically relevant concentrations influence the development and treatment of experimental endocarditis . To study the influence of combination antiplatelet treatment on the development of aortic vegetations, infected animals received either aspirin alone, ticlopidine alone, aspirin plus ticlopidine or no antiplatelet therapy . The combination antiplatelet treated group had a statistically significant (P = 0.043) reduction of the vegetative weight as compared with the untreated controls . While both the single antiplatelet agent groups showed a reduction in the size of the vegetation, neither achieved statistical significance . None of the treatment groups significantly altered the bacterial density relative to untreated controls . These findings reveal that the combination of aspirin and ticlopidine, two potent inhibitors of platelet aggregation with different mechanisms of action, act synergistically to optimally reduce the weight of aortic valve vegetations.

J Arthroplasty, 1999 Apr, 14(3), 339 - 46
The use of vancomycin and tobramycin in acrylic bone cement: biomechanical effects and elution kinetics for use in joint arthroplasty; Klekamp J et al.; We examined the effects of vancomycin on the compressive strength and fatigue life of bone cement and the pharmacokinetics and antimicrobial activity against methicillin-resistant Staphylococcus aureus of vancomycin eluted from bone cement, both alone and in combination with tobramycin . Two cements, Palacos and Simplex, were tested . Three antibiotic preparations were tested: lyophilized vancomycin (vancomycin-L), vancomycin powder (vancomycin-P), and tobramycin powder (Lilly, Indianapolis, IN) . Although antibiotics did not significantly affect compressive strength, the fatigue life of bone cement was significantly decreased with vancomycin . Thus, fatigue testing revealed effects on cement strength not apparent by compression testing . Vancomycin-P had a substantially less detrimental effect on fatigue strength than vancomycin-L . Vancomycin-P elutes less efficiently than tobramycin . Although relatively little vancomycin-P eluted from bone cement, it retained biologic activity.

Microbiology, 1999 Apr, 145 ( Pt 4), 801 - 8
Characterization of a chromosomally encoded glycylglycine endopeptidase of Staphylococcus aureus; Ramadurai L et al.; The authors previously reported the cloning of a lytic-enzyme-encoding gene, lytM, from an autolysis-defective mutant of Staphylococcus aureus . In the present work, the lytM gene was overexpressed in Escherichia coli and the product was purified to homogeneity by affinity chromatography and HPLC . Biochemical analysis of LytM-cleaved peptidoglycan fragments indicated that LytM is a glycylglycine endopeptidase . Immunoelectron microscopic studies with anti-LytM rabbit IgG showed that LytM is expressed during the early exponential phase and is overexpressed in an autolysis-defective mutant compared with the parent strain . Also, a uniform distribution of gold particles on the surface of actively growing bacterial cells indicates that LytM plays a role in cell growth . Northern blot analyses of lytM expression in two global regulatory mutants, agr and sar, showed that expression of lytM is increased about twofold in these mutants as compared with the parents . Protein homology searches revealed that LytM could be a member of the zinc protease family, as it contained a homologous 38-amino-acid motif, Tyr-X-His-X11-Val-X12/20-Gly-X5-6-His . Atomic absorption spectrometric analysis of LytM revealed the presence of 0.9 mol zinc (mol LytM)(-1).

Acta Crystallogr D Biol Crystallogr, 1999 May, 55(5), 1076 - 8
Crystallization and preliminary X-ray crystallographic studies of RepDC, a hybrid rolling-circle plasmid replication initiator protein; Klimenko DE et al.; The hybrid plasmid-replication initiator protein RepDC, which is a fusion of the catalytic fragment of the RepD protein and the DNA-binding fragment of the RepC protein from Staphylococcus aureus, has been successfully crystallized and X-ray data to 3.5 A have been collected on a synchrotron radiation source . Crystals belong to space group I4132 with unit-cell dimensions a = b = c = 165.1 A . The crystals are estimated to contain one protein monomer per asymmetric unit, with 55% solvent content.

Rev Clin Esp, 1999 Feb, 199(2), 55 - 8
{Septic pulmonary embolism in patients on chronic hemodialysis with Staphylococcus aureus bacteremia}; Bello Martinez E et al.; Twenty-one cases of septic pulmonary embolism were selected from a series of 76 patients on chronic haemodialysis diagnosed of S . aureus bacteremia . Ninety percent of patients underwent dialysis through an arteriovenous fistula and 10% by means of a prosthetic access . The most common symptoms were fever (100%), pleuritic pain (66%) and productive cough (55%); twenty-four percent of patients had inflammatory signs at vascular accesses . All patients had some symptoms indicative of pulmonary pathology and all of them had positive blood cultures and findings in the chest X-ray . The clinical course was favourable in 100% of cases . Accesses were lost only in the two cases with prosthetic material . The diagnosis was obtained by chest X-ray and blood cultures . Other more sophisticated tests did not improve the diagnostic yielding.

Ethiop Med J, 1997 Oct, 35(4), 215 - 23
Effect of "siljo" fermentation on growth of Staphylococcus aureus, Bacillus cereus and Listeria monocytogenes; Dessie G et al.; The fate of Staphylococcus aureus, Bacillus cereus, and Listeria monocytogenes in control gruel and fermenting "siljo" was assessed . S . aureus reached levels of 10(8) cfu/ml within 48 h in the control gruel . In fermenting "siljo" the count decreased all through the fermentation time . B.cereus was completely inhibited in fermenting "siljo" within 24 h, whereas it survived until 72 h in the control gruel . Complete inhibition of L.monocytogenes was noted at 48 h in fermenting "siljo" . L.monocytogenes survived until 96 h in control gruel . Fermentation resulted in fall in pH to < 5.0 within 48-72 h and increase in titratable acidity was also noted . As "siljo" is usually consumed after 72 h of fermentation, "siljo" fermented for more than three days is safe from food intoxication caused by B . cereus or S.aureus or infection from L.monocytogenes.

Retina, 1999, 19(2), 127 - 30
Effects of trauma and infection on ciprofloxacin levels in the vitreous cavity; Ozturk F et al.; OBJECTIVE: This study was designed to determine the effects of trauma and infection on vitreous ciprofloxacin levels after intravitreal injection of ciprofloxacin in rabbits . METHODS: A penetrating injury was made in the right eyes of 24 rabbits . In the eyes of half of the traumatized animals, a standardized intraocular infection was induced by intravitreal injection of a suspension of Staphylococcus aureus . The intact left eyes of the traumatized group were maintained as controls . Ciprofloxacin (200 microg/0.1 mL) was injected into the midvitreous cavity of both eyes in all animals and samples were obtained at 2, 8, 24, and 48 hours after injection . Drug concentrations were measured using high-pressure liquid chromatography analysis . RESULTS: At the second hour, the mean vitreous concentration of ciprofloxacin in the traumatized eyes was lower than that in control eyes (P<0.05) . The mean ciprofloxacin concentrations were significantly higher (P<0.05) in the traumatized-infected eyes than were those in control or traumatized eyes at 24 and 48 hours . The elimination half-life of ciprofloxacin in control and traumatized eyes was 6.02 hours and 5.02 hours, respectively, and infection prolonged the half-life to 15.06 hours . Vitreous levels of ciprofloxacin were above the minimum inhibitory concentration (MIC90) for most of the common microorganisms causing endophthalmitis in all groups at 2 and 8 hours, but also at 24 and 48 hours in traumatized-infected eyes . CONCLUSION: Infection appears to decrease the clearance of ciprofloxacin . Therapeutic drug levels in traumatized-infected eyes were maintained up to 48 hours . Assuming that the animal model used may have a predictive value for the drug elimination in traumatized-infected human eyes, we suggest that local administration of ciprofloxacin every 2 days may be relevant from the therapeutic perspective.

J Dairy Sci, 1999 Apr, 82(4), 696 - 703
Comparison of tilmicosin and cephapirin as therapeutics for Staphylococcus aureus mastitis at dry-off; Nickerson SC et al.; Forty-four cows (26 Jerseys and 18 Holsteins) that had at least 1 mammary quarter that was naturally (n = 12) or experimentally (n = 84) infected with Staphylococcus aureus were allotted to three treatment groups of approximately equal number at the end of lactation . Cows were dried off by abrupt cessation of milking, and dry cow therapy was administered as an intramammary infusion of cephapirin benzathine at 10 ml per quarter, an intramammary infusion of tilmicosin (solution containing 300 mg/ml) at 5 ml per quarter, or a subcutaneous injection of tilmicosin at 5 mg/kg of body weight on the day of drying off and another injection 4 d later . Mammary secretions were monitored during the dry period and postpartum for antimicrobial residues, intramammary infection (IMI) status, and somatic cell counts . Results demonstrated the following percentage cures for IMI caused by Staph . aureus at 28 d postcalving based on individual mammary quarters: cephapirin benzathine, 78.1%; tilmicosin infused, 74.2%; and tilmicosin injected, 9.1% . During the first 4 wk after drying off, the mean concentration of tilmicosin in mammary secretions from cows infused with the antibiotic remained approximately 10-fold higher than that in secretions from cows injected with the antibiotic (3.43 vs . 0.32 ppm), and, by the time of calving, concentrations for cows treated with both methods were below the dilution limit of the assay (< 0.1 ppm) . Results demonstrated that intramammary infusion of tilmicosin was equally as effective as cephapirin benzathine in curing IMI caused by Staph . aureus at drying off; however, the subcutaneous injection of tilmicosin at the dose used was not effective as a dry cow therapeutic against Staph . aureus.

J Biol Chem, 1999 Apr 30, 274(18), 12855 - 60
Rat liver serine dehydratase . Bacterial expression and two folding domains as revealed by limited proteolysis; Ogawa H et al.; A pCW vector harboring rat liver serine dehydratase cDNA was expressed in Escherichia coli . The expressed level was about 5-fold higher in E . coli BL21 than in JM109 cell extract; the former lacked two kinds of proteases . Immunoblot analysis revealed the occurrence of a derivative other than serine dehydratase in the JM109 cell extract . The recombinant enzyme was purified to homogeneity . Staphylococcus aureus V8 protease and trypsin cleaved the enzyme at Glu-206 and Lys-220, respectively, with a concomitant loss of enzyme activity . Spectrophotometrically, the nicked enzyme showed a approximately 50% reduced capacity for binding of the coenzyme pyridoxal phosphate and no spectral change of circular dichroism in the region at 300-480 nm, whereas circular dichroism spectra of both enzymes in the far-UV region were similar, suggesting that proteolysis impairs the coenzyme binding without an accompanying gross change of the secondary structure . Whereas the nicked enzyme behaved like the intact enzyme on Sephadex G-75 column chromatography, it was dissociated into two fragments on the column containing 6 M urea . Upon the removal of urea, both fragments spontaneously refolded . These results suggest that serine dehydratase consists of two folding domains connected by a region that is very susceptible to proteases.

J Pediatr Surg, 1999 Mar, 34(3), 381 - 6
Multiple intestinal ulcerations and perforations secondary to methicillin-resistant Staphylococcus aureus enteritis in infants; Han SJ et al.; PURPOSE: The aim of this study was to define a distinctive clinical entity of multiple intestinal ulcerations and perforations in infants . METHODS: Two infants underwent abdominal exploration for surgical abdomen and were noted to have multiple intestinal ulcerations and perforations . A peculiar and unique surgical finding, numerous transverse linear ulcerations scattered along the entire small intestine, prompted us to search for similar instances . Five similar cases were additionally identified by members of the Korean Association of Pediatric Surgeons . The clinical courses, the surgical findings, and the results of bacterial cultures were reviewed . As well, the tissues of resected intestines were examined histopathologically . RESULTS: The characteristics of this entity are as follows . (1) It usually occurs in infants who have been treated with broad-spectrum antibiotics . (2) Despite broad-spectrum antibiotic treatment, diarrhea and abdominal distension developed progressively and deteriorated . (3) Histological evaluation showed mucosal ulcers with neutrophil infiltration, submucosal microabscesses, and colonies of Gram-positive cocci . (4) Methicillin-resistant Staphylococcus aureus (MRSA) was the predominant organism cultured from the body fluid . (5) Only two cases, the completely resected one and the one immediately treated postoperatively with vancomycin, survived . CONCLUSIONS: This entity is caused by multiple intestinal ulcerations and perforations secondary to MRSA enteritis in infants . It has a high mortality rate because of its difficult diagnosis . However, early recognition of this entity can lead to successful treatment.

Surg Today, 1999, 29(4), 327 - 37
Methicillin-resistant Staphylococcus aureus proliferation in the rat gut is influenced by gastric acid inhibition and the administration of antibiotics; Yoshida Y; The author studied methicillin-resistant Staphylococcus aureus (MRSA) proliferation in the rat gut which was influenced by gastric acid inhibition and the administration of antibiotics . When male Wistar rats were bred by total parenteral nutrition (TPN), and were continuously administered famotidine 4 mg/kg per day, the gastric acidity was observed to decrease to pH 6.4+/-0.1 . However, when they were bred by TPN, and histamine 4 mg/kg per hour was continuously administered, the gastric acidity was observed to increase to pH 1.9+/-0.4 . MRSA was thus able to cross over to the small intestine only during the famotidine medication . If rats were intravenously administered latamoxef (LMOX) after an oral inoculation of MRSA, then the viable MRSA counts in the stomach, small intestine, and large intestine all decreased on day 4 . In contrast, if the gastric acidity decreased and the rats were treated by an oral administration of kanamycin and metronidazole before an oral inoculation of MRSA and thereafter were administered LMOX, then the MRSA count significantly increased . It is thus concluded that a suppression of gastric acid and a great disorder of the intestinal flora is indispensable for the colonization of MRSA into the small intestine, while in vitro the propagation of MRSA requires a continuity of suppression absent in the bacterial flora.

Biochim Biophys Acta, 1999 Apr 12, 1431(1), 132 - 47
The role of the non-conserved residue at position 104 of class A beta-lactamases in susceptibility to mechanism-based inhibitors; Guo F et al.; The role of the non-conserved amino acid residue at position 104 of the class A beta-lactamases, which comprises a highly conserved sequence of amino acids at the active sites of these enzymes, in both the hydrolysis of beta-lactam substrates and inactivation by mechanism-based inhibitors was investigated . Site-directed mutagenesis was performed on the penPC gene encoding the Bacillus cereus 569/H beta-lactamase I to replace Asp104 with the corresponding Staphylococcus aureus PC1 residue Ala104 . Kinetic data obtained with the purified Asp104Ala B . cereus 569/H beta-lactamase I was compared to that obtained from the wild-type B . cereus and S . aureus enzymes . Replacement of amino acid residue 104 had little effect on the Michaelis parameters for the hydrolysis of both S- and A-type penicillins . Relative to wild-type enzyme, the Asp104Ala beta-lactamase I had 2-fold higher Km values for benzylpenicillin and methicillin, but negligible difference in Km for ampicillin and oxacillin . However, kcat values were also slightly increased resulting in little change in catalytic efficiency, kcat/Km . In contrast, the Asp104Ala beta-lactamase I became more like the S . aureus enzyme in its response to the mechanism-based inhibitors clavulanic acid and 6-beta-(trifluoromethane sulfonyl)amido-penicillanic acid sulfone with respect to both response to the inhibitors and subsequent enzymatic properties . Based on the known three-dimensional structures of the Bacillus licheniformis 749/C, Escherichia coli TEM and S . aureus PC1 beta-lactamases, a model for the role of the non-conserved residue at position 104 in the process of inactivation by mechanism-based inhibitors is proposed.

Biomaterials, 1999 Apr, 20(7), 647 - 54
Spectroscopic investigation of tertiary fold of staphylococcal protein A to explore its engineering application; Kikuchi J et al.; Staphylococcal protein A is a cell wall constituent of most strains of Staphylococcus aureus, and it is characterized by its binding affinity to some immunological classes . A mutated low molecular weight type protein A (LPA; Mwt = 27 kDa) which consists of the domains, E, D, A, B and 13 residues of the C-domain was prepared in this study . Since LPA does not possess a cell wall-bound region in contrast to wild-type protein A (WPA; Mwt = 42 kDa), we have established a methodology of large scale purification of LPA without using any extracellular expression systems such as Escherichia coli . Using this relatively abundant protein, the immobilization of the LPA with silk fibroin of Bombyx mori was performed . Thermal stability of LPA immobilized with silk fibroin is higher than that of free LPA at high temperature judging from the immunoglobulin G (IgG)-binding affinity . However, the apparent value of its affinity decreased relative to that of immobilized WPA . These results indicate that structural information is essential to explore improvement of IgG-binding affinity of immobilized LPA . Therefore, secondary structure of free LPA was detected by its characteristic helical pattern in circular dichroism (CD) in aqueous solution . In addition to this, tertiary fold of four IgG-binding domains were investigated by two-dimensional 1H-NMR spectra . Four significantly high-field shifted cross-peaks attributed to methyl signals of alanine residues suggest that all four domains pack into a three helix bundle motif in solution . These structural data and properties of IgG-binding affinity suggest that spatial arrangement of four IgG-binding domains are packed into a compact globular molecular shape . This causes a certain active site of immobilized LPA to be buried in the silk fibroin fiber.

Microbiology, 1999 Jan, 145 ( Pt 1), 177 - 83
Staphylococcus aureus expresses a cell surface protein that binds both IgG and beta2-glycoprotein I; Zhang L et al.; The existence of a second IgG-binding protein, protein Sbi, in Staphylococcus aureus has been reported previously . Later data indicated that protein Sbi also bound another serum component . This component has now been affinity-purified on immobilized protein Sbi and identified as beta2-glycoprotein I (beta2-GPI), also known as apolipoprotein H . The minimal beta2-GPI-binding domain was identified by shotgun phage display and the binding was shown to be mediated by a region of 57 amino acids, clearly separated from the IgG-binding domain . It is also shown that protein Sbi, and thus the beta2-GPI-binding activity, is expressed on the staphylococcal cell surface at levels varying between strains.

Eur J Pediatr, 1999 Apr, 158(4), 312 - 4
Neonatal suppurative parotitis: a study of five cases; Sabatino G et al.; Suppurative parotitis is uncommon in newborns . During a 9-year study period, five cases of neonatal suppurative parotitis were detected in 3,624 hospital admissions . The relative risk of developing neonatal suppurative parotitis in admitted infants was 5.52 (0.62-49.35) . Staphylococcus aureus was the causative organism most commonly detected in the hospital-acquired cases . Antimicrobial therapy was effective in all cases; surgery was not required . CONCLUSION: Although neonatal suppurative parotitis is now uncommon in the newborn, it cannot be considered a "vanishing disease".

J Hosp Infect, 1999 Mar, 41(3), 223 - 8
Outcome following haemodialysis catheter-related Staphylococcus aureus bacteraemia; Peacock SJ et al.; Staphylococcus aureus is a frequent cause of haemodialysis access-related bacteraemia . The propensity for this organism to seed from the bloodstream to distant sites is well recognized, but the rate at which this occurs is poorly defined in patients with removable haemodialysis catheters . This retrospective study identified 47 patients with 50 episodes of S . aureus haemodialysis catheter-related bacteraemia between August 1993 and December 1995 . Adverse events were recorded until February 1996 . Thirty of 50 episodes (60%) were apparently uncomplicated . Bacterial seeding to heart valves or distant sites was documented in eight episodes (16%), of which six occurred during antibiotic therapy . A further 12 patients had persistent bacteraemia in the absence of a defined focus of infection, the last positive blood culture ranging from 2-19 days (mean 6.6, median 5) after removal of the haemodialysis catheter and commencing appropriate antibiotic treatment . The serious nature of this infection confirms the need for prevention, together with effective strategies for investigation and treatment in this patient population.

J Hosp Infect, 1999 Mar, 41(3), 173 - 9
All Wales surveillance of methicillin-resistant Staphylococcus aureus (MRSA): the first year's results; Morgan M et al.; Over the last five years, hospitals in Wales have experienced difficulties with increasing numbers of isolates of methicillin-resistant Staphylococcus aureus (MRSA) . Continuous total population surveillance of MRSA was introduced with the objectives of gaining an understanding of the extent and variation in time and place of its occurrence, the burden of disease and possible risk factors associated with its isolation and resistance to other antibiotics . All first isolates of MRSA from both hospital and community settings and all isolates of methicillin-sensitive Staphylococcus aureus (MSSA) associated with bacteraemia and cerebrospinal fluid (CSF) isolates detected in medical microbiology laboratories in Wales were collected via CoSurv, a set of interconnected data-base modules for communicable disease control . A data set was collected on each isolate and the patient associated with that isolate and compiled centrally at CDSC (Wales) for all-Wales analysis of the MRSA situation . Surveillance started in January 1996 and at the end of the first year, 2700 new isolates of MRSA had been reported from hospital and community settings, giving a rate of 92.43/100,000 population . The incidence of MRSA from bacteraemias and CSF was 5.20/100,000 compared with 12.70/100,000 for MSSA . MRSA from bacteraemia and CSF was significantly more commonly associated with male patients than MSSA . MRSA patients were significantly older . For all MRSA isolates, the highest reporting rate was in men aged 75+ (647.21/100,000) . The highest incidence of invasive disease was also in men aged 75+ (45.69/100,000) . Isolates from post-surgical patients were more likely to be involved in invasive disease (OR = 2.59), P < 0.001) than strains from other sources . The majority of isolates were resistant to at least two antibiotics in addition to methicillin, most frequently erythromycin and the fluoroquinolones . Very little resistance to fusidic acid, mupirocin or rifampicin was reported . Continuous total population surveillance has provided a minimum incidence of MRSA in Wales and has allowed a simple and intelligible picture of the problem to be determined, which has been fed back to hospitals to assist decisions on control.

J Clin Microbiol, 1999 May, 37(5), 1619 - 20
Misclassification of susceptible strains of Staphylococcus aureus as methicillin-resistant S . aureus By a rapid automated susceptibility testing system; Ribeiro J et al.; Eight Staphylococcus aureus strains initially identified by Vitek GPS-BS or GPS-SA cards as resistant to oxacillin, but susceptible to most non-beta-lactam antibiotics, were found on further testing to be susceptible to oxacillin and ceftizoxime by disk diffusion tests . For all these strains, the MICs of oxacillin were </=0.5 microg/ml by agar dilution tests, and the strains were oxacillin susceptible when tested by the BBL Crystal MRSA ID and a Vitek machine with GPS-101 cards . None grew on oxacillin-salt agar screening plates . None were positive for mecA gene sequences by PCR . When S . aureus strains tested by Vitek GPS-SA or GPS-BS cards appear resistant to only penicillin and oxacillin, a confirmatory test such as the oxacillin-salt agar screening method should be performed.

J Clin Microbiol, 1999 May, 37(5), 1591 - 4
Evaluation of MRSA-Screen, a simple anti-PBP 2a slide latex agglutination kit, for rapid detection of methicillin resistance in Staphylococcus aureus; Cavassini M et al.; The MRSA-Screen test (Denka Seiken Co., Ltd., Tokyo, Japan), consisting of a slide latex agglutination kit that detects PBP 2a with a monoclonal antibody, was blindly compared to the oxacillin disk diffusion test, the oxacillin-salt agar screen, and PCR of the mecA gene for the detection of methicillin resistance in Staphylococcus aureus . A total of 120 methicillin-susceptible S . aureus (MSSA) and 80 methicillin-resistant S . aureus (MRSA) isolates, defined by the absence or presence of the mecA gene, respectively, were tested . The MRSA-Screen test, the oxacillin disk diffusion test, and the oxacillin-salt agar screening test showed sensitivities of 100, 61.3, and 82.5% and specificities of 99.2, 96.7, and 98.3%, respectively . We conclude that the MRSA-Screen is a very accurate, reliable, and fast test (15 min) for differentiation of MRSA from MSSA colonies on agar plates.

J Clin Microbiol, 1999 May, 37(5), 1459 - 63
Methicillin-resistant Staphylococcus aureus outbreak in a veterinary teaching hospital: potential human-to-animal transmission; Seguin JC et al.; During a 13-month period, 11 equine patients visiting a veterinary teaching hospital for various diagnostic and surgical procedures developed postprocedural infections from which methicillin (oxacillin)-resistant Staphylococcus aureus (MRSA) strains were isolated . The S . aureus isolates were identified by conventional methods that included Gram staining, tests for colonial morphology, tests for clumping factor, and tests for coagulase and urease activities and were also tested with the API STAPH IDENT system . Antimicrobial susceptibility tests were performed by the disk diffusion method . The biochemical profile and antibiogram of each isolate suggested that the isolates may have come from a common source . Because MRSA strains are very uncommon animal isolates but are rather common human isolates, a nasal swab specimen for culture was collected voluntarily from five persons associated with equine surgery and recovery in an attempt to identify a possible source of the organisms . MRSA strains were isolated from three of the five people, with one person found to be colonized with two biotypes of MRSA . The MRSA isolates from the people appeared to be identical to the isolates from horses . Further study of the isolates included SmaI and EagI macrorestriction analysis by pulsed-field gel electrophoresis conducted in two different laboratories . The results indicated that both the equine and human isolates were members of a very closely related group which appear to have originated from a common source . On the basis of the pattern associated with the infection, it is speculated that the members of the Veterinary Teaching Hospital staff were the primary source of the infection, although the specific mode of transmission is unclear.

J Refract Surg, 1999 Mar-Apr, 15(2 Suppl), 216 - 7
Bacterial keratitis following laser in situ keratomileusis for hyperopia; al-Reefy M; A 42-year-old Bahraini man had uneventful laser in situ keratomileusis for hyperopia (OD: +3.00 +0.75 x 155 degrees; OS: +2.00 +0.50 x 155 degrees) . Three weeks later, he presented with localized keratitis in his right eye, with localized keratitis at the flap margin with stromal edema . Uncorrected visual acuity was 20/80 OD with no improvement with pinhole, and was 20/20 OS . Corneal smear culture showed a positive growth of Staphylococcus aureus . The patient was immediately treated with subconjunctival gentamicin and intensive topical ofloxacin 0.3% with systemic cephalosporin . The patient recovered from keratitis within 2 weeks and his uncorrected visual acuity OD improved to 20/20 . Keratitis following LASIK should be treated promptly so that it does not lead to permanent reduction in visual acuity.

Ugeskr Laeger, 1999 Mar 15, 161(11), 1580 - 4
{Carriers of Staphylococcus aureus as a source of nosocomial infections . Epidemiological and prophylactic aspects}; Kolmos HJ; 20% of the normal population are nasal carriers of Staphylococcus aureus (Sa), and the carrier rate is even higher in insulin dependent diabetics, intravenous drug addicts, patients on haemo- and peritoneal dialysis, and HIV infected patients . Nasal Sa carriers have an increased risk of Sa infections following invasive therapy . Mupirocin, a novel topical antibiotic, is highly effective against nasal Sa . A number of studies indicate that it may reduce the incidence of Sa infections in dialysis patients, however experience with other categories of patients is sparse . Surgical wound infection with Sa is a particularly serious complication after implantation of foreign body material, e.g . artificial joints . There is a need for controlled clinical trials to test the efficacy of mupirocin in eradicating Sa in these types of patients . Uncritical use of mupirocin for topical treatment of wounds should be avoided in order to prevent development of resistance.

J Immunol, 1999 Apr 15, 162(8), 4801 - 5
CD14 plays no major role in shock induced by Staphylococcus aureus but down-regulates TNF-alpha production; Haziot A et al.; Recent in vitro studies have suggested that CD14, a major receptor for LPS, may also be a receptor for cell wall components of Gram-positive bacteria and thus play a role in Gram-positive shock . To analyze the in vivo role of CD14 in responses to Gram-positive bacteria, CD14-deficient and control mice were injected with Staphylococcus aureus, and the effects on lethality, bacterial clearance, and production of cytokines were analyzed . Survival of CD14-deficient and control mice did not differ significantly after administration of various doses of either unencapsulated or encapsulated S . aureus; furthermore, mice in both groups displayed similar symptoms of shock . In addition, inflammatory cytokines such as TNF-alpha and IL-6 were readily detectable in the serum of CD14-deficient mice injected with live or antibiotic-killed S . aureus . Surprisingly, the serum concentration of TNF-alpha in CD14-deficient mice was at least threefold higher than in control mice after injection of either unencapsulated or encapsulated S . aureus, suggesting that CD14 down-regulates TNF-alpha . A similar increase in serum TNF-alpha occurred when CD14-deficient animals were injected with gentamicin-killed bacteria even though no symptoms of shock were observed . These studies indicate that CD14, in contrast to its key function in responses to the Gram-negative bacterium, Escherichia coli 0111, does not play a prominent role in septic shock induced by S . aureus, and that the symptoms of S . aureus shock are not due solely to TNF-alpha.

J Immunol, 1999 Apr 15, 162(8), 4550 - 9
Unique superantigen activity of staphylococcal exfoliative toxins; Monday SR et al.; Certain strains of Staphylococcus aureus express one or both of two related, but immunologically distinct, exfoliative toxins (ETA and ETB) . These toxins induce the symptoms associated with staphylococcal scalded skin syndrome . Both ETs have been shown to stimulate T cell proliferation . Recently, it was reported that ETA is a superantigen that stimulates T cells bearing human Vbeta2 or several murine Vbetas . However, other investigators have proposed that the superantigenicity reported for ETA resulted from contaminants in commercial preparations . This present study addresses those conflicting reports by assessing the biological and immunologic activities of highly purified rETs . ETA and ETB required APCs to induce selective polyclonal expansion of several human Vbetas (huVbetas), although, neither toxin expanded huVbeta2 . ETB induced expansion of murine T cells bearing Vbetas 7 and 8, those that have the highest homology to the huVbetas expanded by ETA and ETB . Although flow cytometry of ETB-stimulated T cells matched PCR results, stimulation by ETA reduced percentages of T cells positive for several huVbetas that had been shown to have increased levels of mRNA transcripts . ETA and ETB induced contrasting reactions in vivo . In rabbits, ETB was moderately pyrogenic and enhanced susceptibility to lethal shock, while ETA lacked both activities . Predictions based on comparisons with other superantigens suggest molecular regions potentially involved in receptor binding in the ETA crystal structure and a modeled ETB three-dimensional structure . These results show that ETs are superantigens with unique properties that could account for the discrepancies reported.

Aust N Z J Med, 1999 Feb, 29(1), 66 - 72
Investigation of a cluster of Staphylococcus aureus invasive infection in the top end of the Northern Territory; Skull SA et al.; INTRODUCTION: Staphylococcus aureus invasive infection remains a serious condition associated with considerable morbidity and mortality . Following notification of five cases at Royal Darwin Hospital (RDH), we searched for related cases, determined their epidemiological characteristics and attempted to identify the source of this apparent cluster . METHODS: We reviewed RDH microbiology records between June 1996 and April 1997 for S . aureus isolates with similar antibiograms to notified cases . We used antibiotic resistance patterns, bacteriophage typing and two molecular typing techniques to subtype implicated isolates . Hospital records were reviewed for admission details and associated costs were estimated . RESULTS: Fifty-four cluster-related isolates occurred in 47 separate presentations . The peak incidence was in the wet season . The most important risk factor for staphylococcal invasive infection was the presence of skin sores/scabies in 17/54 cases (31%), followed by intravascular line use in 14/54 (26%), open trauma in 11/54 (20%), underlying end stage renal failure and alcoholism each in ten of 54 (18%) . The mean admission length was 30 days and antibiotics were given for an average of 23 days . Death due to S . aureus infection occurred in eight of 47 (17%) presentations . S . aureus pneumonia was community acquired in 12/13 patients (92%) and six of 13 (46%) died . Ten of 13 (80%) pneumonia patients had at least one other focus of S . aureus infection . The cost of antibiotics and hospital bed per presentation was approximately $16,000 . Presentations with skin sores/scabies cost considerably more ($31,000) . No common epidemiologic features were found for community or hospital acquired cases . CONCLUSION: Considerable mortality and cost was attributable to cases of S . aureus invasive infection during this cluster; particularly those with community acquired pneumonia or skin sores/scabies . Staphylococcal antibiotic cover should be considered early for unwell patients presenting to hospital with pneumonia and other signs of potential S . aureus infection . It is appropriate to target public health efforts to prevent skin sores and to provide adequate treatment when they occur.

Crit Care Med, 1999 Mar, 27(3), 549 - 53
Neutrophil function capacity to express CD10 is decreased in patients with septic shock; Martens A et al.; OBJECTIVE: To evaluate the performance of a newly developed assay to assess neutrophil function capacity . After optimization, the assay was performed on samples derived from patients with septic shock and compared with healthy controls and patients with a systemic viral infection . DESIGN: Prospective evaluation of the performance of a new assay . SETTINGS: Medical intensive care unit, hospital laboratory . PATIENTS: Ten patients with septic shock, ten patients with infectious mononucleosis, and ten healthy controls . MEASUREMENTS AND MAIN RESULTS: We report an assay to assess neutrophil function capacity, in which CD10 membrane expression is measured by FACS before and after in vitro stimulation with Staphylococcus aureus bacteria . This assay evaluates the early activation state of circulating neutrophils and is shown to be of value in diagnosing a sepsis syndrome . First the assay was optimized . As an anticoagulant, sodium-citrate gave the best results . Blood samples must be kept on ice to reduce activation inside the siliconized tube and can be stored in this way for at least 8 hrs without affecting the test results . Kinetic studies showed a maximal expression of CD10 on neutrophils of healthy volunteers after 15 mins of stimulation with S . aureus bacteria . Second, the test was performed on samples derived from ten septic patients and ten patients with infectious mononucleosis . Septic patients had a significantly decreased CD10 expression capacity compared with healthy controls . Patients with infectious mononucleosis have a significantly higher CD10 expression capacity compared with septic patients, but in approximately one-half of them, the expression capacity was below the range found in controls . CONCLUSIONS: These results indicate that in circulating neutrophils, the secretory vesicles have been mobilized completely in patients with septic shock . The assay proves to be of acceptable analytical quality and can be quickly and easily performed . Regarding clinical performance, this assay may be helpful in diagnosing septic shock.

Br J Biomed Sci, 1998 Jun, 55(2), 99 - 106
Motif-dependent DNA analysis of a methicillin-resistant Staphylococcus aureus collection; Cotter L et al.; Methicillin-resistant Staphylococcus aureus (MRSA) has become a major nosocomial pathogen in recent years . Once introduced into the hospital environment, MRSA can spread rapidly, and its subsequent treatment is often difficult as it may be simultaneously resistant to several antibiotics . A useful strategy both to identify the source of infection and to monitor specific infecting strains would be beneficial, facilitating the implementation of control and preventive measures . In this study, a typing strategy, based on the amplification of a conserved repeat-motif in the bacterial genome, was applied in a hospital setting to analyse an MRSA collection . Using a fluorescent-labelled oligonucleotide primer RW3A, which annealed to several dispersed short-repeat sequences occurring throughout the bacterial genome, DNA amplification fingerprint patterns were produced by polymerase chain reaction (PCR) . Thirty-nine MRSA isolates were successfully analysed using conventional agarose gel electrophoresis and GeneScan technology . The latter method provides a finer resolution, making use of capillary electrophoresis in an ABI Prism 310 genetic analyser . The fluorescent detection approach can facilitate the construction of a fingerprint database which can be accessed for comparison of any isolate . Quantitative analysis of all patterns divided the MRSA isolates into four different groups, based on their RW3A fingerprints . Most of the isolates (88%) were assigned to one of three main groups, while the remaining isolates (12%) comprised a fourth, miscellaneous group.

J Bacteriol, 1999 Apr, 181(8), 2492 - 500
Promoter analysis of the cap8 operon, involved in type 8 capsular polysaccharide production in Staphylococcus aureus; Ouyang S et al.; The production of type 8 capsular polysaccharide (CP8) in Staphylococcus aureus is regulated in response to a variety of environmental factors . The cap8 genes required for the CP8 production in strain Becker are transcribed as a single large transcript by a primary promoter located within a 0.45-kb region upstream of the first gene of the cap8 gene cluster . In this study, we analyzed the primary cap8 promoter region in detail . We determined the transcription initiation site of the primary transcript by primer extension and identified the potential promoter sequences . We found several inverted and direct repeats upstream of the promoter . Deletion analysis and site-directed mutagenesis showed that a 10-bp inverted repeat of one of the repeats was required for promoter activity . We showed that the distance but not the specific sequences between the inverted repeat and the promoter was critical to the promoter activity . However, insertion of a DNA sequence with two or four helix turns in this intervening region had a slight effect on promoter activity . To demonstrate the biological significance of the 10-bp inverted repeat, we constructed a strain with a mutation in the repeat in the S . aureus Becker chromosome and showed that the repeat affected CP8 production mostly at the transcriptional level . By gel mobility shift assay, we demonstrated that strain Becker produced at least one protein capable of specific binding to the 10-bp inverted repeat, indicating that the repeat serves as a positive regulatory protein binding site . In addition, reporter gene fusion analysis showed that the cap8 promoter activity was influenced by various growth media and affected most by yeast extract . Our results suggest that yeast extract may exert its profound inhibitory effect on cap8 gene expression through the 10-bp inverted repeat element.

Ann Thorac Surg, 1999 Feb, 67(2), 533 - 5
The Freestyle stentless bioprosthesis for prosthetic valve endocarditis; Sakaguchi T et al.; We report a case of methicillin-resistant Staphylococcus aureus-induced prosthetic valve endocarditis, which was successfully treated with aortic valve replacement using the Freestyle stentless bioprosthesis . The total root and stentless design of this bioprosthesis allows for more radical removal of infected tissue and easier treatment for annular abscess, while requiring less prosthetic materials than a conventional prosthesis . This bioprosthesis thus seems to be a valuable option for active endocarditis.

J Pept Res, 1999 Jan, 53(1), 47 - 55
Addition and omission analogs of the 13-residue antibacterial and hemolytic peptide PKLLKTFLSKWIG: structural preferences, model membrane binding and biological activities; Bikshapathy E et al.; The consequences of selective addition or deletion of polar amino acids in a 13-residue antibacterial peptide PKLLKTFLSKWIG on structure, membrane binding and biological activities have been investigated . The variants generated are (a) S and T residues replaced by K, (b) S and T residues deleted individually and together, (c) introduction of two additional K and (d) deletion of L and L with T . In the aqueous environment all the peptides were unordered . In trifluoroethanol, the spectra of peptides belonging to groups (a-c) suggest distorted helical conformation . Peptides in group (d) appear to adopt beta-sheet conformation . The peptides bind to zwitterionic and negatively charged lipid vesicles, although to different extents . With the exception of peptides in group (d), all the other peptides exhibited comparable antibacterial activity against Escherichia coli and Staphylococcus aureus . However, the changes made in the peptides in groups (a-c) resulted in reduction of hemolytic activity compared to the parent peptide . Extent of binding to lipid vesicles composed of phosphatidylcholine and cholesterol appears to correlate with hemolytic activity . It appears that polar and charged residues play a major role in modulating the biological activities of the 13-residue peptide PKLLKTFLSKWIG . The 11-residue peptide-like PKLLKFLKWIG has selective antibacterial activity . Thus, by judicious engineering it should be possible to generate short peptides with selective antibacterial activity.

Protein Eng, 1999 Feb, 12(2), 173 - 8
Hydrophobicity engineering of cholera toxin A1 subunit in the strong adjuvant fusion protein CTA1-DD; Agren L et al.; Protein engineering of the cholera toxin A1 subunit (CTA1) fused to a dimer of the Ig-binding D-region of Staphylococcus aureus protein A (DD) was employed to investigate the effect of specific amino acid changes on solubility, stability, enzymatic activity and capacity to act as an adjuvant in vivo . A series of CTA1-DD analogues were selected by a rational modeling approach, in which surface-exposed hydrophobic amino acids of CTA1 were exchanged for hydrophilic counterparts modeled for best structural fit . Of six different mutants initially produced, two analogues, CTA1Phe132Ser-DD and CTA1Pro185Gln-DD, were demonstrated to have 50 and 70% increased solubility, respectively, at neutral pH . The double mutant CTA1Phe132Ser/Pro185Gln-DD was at least threefold more soluble, demonstrating an additive effect of the two mutations . Only the Phe132Ser analogue retained full biological activity and stability compared with the native CTA1-DD fusion protein . Two mutants, Pro185Gln and Phe31His mutations, exhibited unaltered ADP-ribosyltransferase activity in vitro, but demonstrated markedly reduced adjuvant function . Since the Pro185 and Phe31 amino acids are located in close vicinity on the distal side of the molecule relative to the enzymatically active cleft, it is conceivable that this region is involved in mediating a biological function, separate from the enzymatic activity but intrinsic to the adjuvant activity of CTA1.

J Dairy Sci, 1999 Mar, 82(3), 645 - 7
Efficacy of parenterally or intramammarily administered tilmicosin or ceftiofur against Staphylococcus aureus mastitis during lactation; Owens WE et al.; Two antibiotic preparations, tilmicosin and ceftiofur, were tested intramammarily and parenterally against Staphylococcus aureus mastitis in lactating cows . Neither product was effective as a lactating cow treatment at the doses and durations of treatment tested . Injection or infusion of tilmicosin and infusion of ceftiofur resulted in reductions of bacteria present in milk; however, only one quarter treated with infusion of tilmicosin was cured, and no cures were observed for the other treatments . Somatic cell counts were transiently reduced by infusion of ceftiofur and by infusion and injection of tilmicosin; however, they returned to pretreatment values by 28 d posttreatment.

Clin Microbiol Rev, 1999 Apr, 12(2), 224 - 42
Clinical, microbial, and biochemical aspects of the exfoliative toxins causing staphylococcal scalded-skin syndrome; Ladhani S et al.; The exfoliative (epidermolytic) toxins of Staphylococcus aureus are the causative agents of the staphylococcal scalded-skin syndrome (SSSS), a blistering skin disorder that predominantly affects children . Clinical features of SSSS vary along a spectrum, ranging from a few localized blisters to generalized exfoliation covering almost the entire body . The toxins act specifically at the zona granulosa of the epidermis to produce the characteristic exfoliation, although the mechanism by which this is achieved is still poorly understood . Despite the availability of antibiotics, SSSS carries a significant mortality rate, particularly among neonates with secondary complications of epidermal loss and among adults with underlying diseases . The aim of this article is to provide a comprehensive review of the literature spanning more than a century and to cover all aspects of the disease . The epidemiology, clinical features, potential complications, risk factors, susceptibility, diagnosis, differential diagnoses, investigations currently available, treatment options, and preventive measures are all discussed in detail . Recent crystallographic data on the toxins has provided us with a clearer and more defined approach to studying the disease . Understanding their mode of action has important implications in future treatment and prevention of SSSS and other diseases, and knowledge of their specific site of action may provide a useful tool for physiologists, dermatologists, and pharmacologists.

Biochemistry, 1999 Apr 6, 38(14), 4296 - 302
The staphylococcal alpha-toxin pore has a flexible conformation; Vecsey-Semjen B et al.; The alpha-toxin from Staphylococcus aureus undergoes several conformational changes from the time it is released from the bacterium to the moment it forms a channel in the plasma membrane of its target cell . It is initially a soluble monomer, which undergoes membrane binding and oligomerization into a heptameric ring and finally inserts into the lipid bilayer to form a pore . Here we have analyzed the stability of different forms of the alpha-toxin (monomer as well as heptamers in solution, bound to the membrane and membrane-inserted) by differential scanning calorimetry and limited proteolysis . Data presented here show that, in contrast to both the membrane-bound prepore complex and the monomer in solution, the membrane-inserted alpha-toxin channel does not undergo cooperative unfolding and is highly susceptible to proteases . These observations suggest that the channel has a looser conformation . Interestingly, resistance to proteases could be recovered upon solubilization of the channel, indicating that the loss of rigid tertiary packing only occurred upon membrane insertion . Far-UV CD data, however, suggest that the transmembrane beta-barrel must be stably folded and that therefore only the Cap and Rim domains of the channel are loosely packed . All together, our data show that the alpha-toxin channel is not a rigid complex within the membrane but adopts a rather flexible conformation.

Clin Exp Immunol, 1999 Mar, 115(3), 377 - 82
Intracellular interferon-gamma (IFN-gamma) production in normal children and children with atopic dermatitis; Campbell DE et al.; A reduction in the in vitro production of IFN-gamma has been consistently described in atopic dermatitis (AD) . Whether this reduction is due to a decrease in the population of peripheral blood mononuclear cells (PBMC) producing IFN-gamma or reduced IFN-gamma production per cell, or a combination of both is not clear . We have examined the intracellular production of IFN-gamma in children with AD and in healthy non-atopic controls . As Staphylococcus aureus colonization is a feature of childhood AD, and is postulated to contribute to the cutaneous inflammation in atopic dermatitis, S . aureus and Staphylococcal enterotoxin B (SEB) were used to activate PBMC . Stimulated PBMC from subjects with AD had significantly fewer IFN-gamma-containing cells in response to SEB (P < 0.001) and S . aureus (P < 0.01) than normal non-atopic children . In addition, SEB-stimulated PBMC from children with AD had less IFN-gamma per cell than normal non-atopic children (P < 0.01) . Reduction in the proportion of cells containing IFN-gamma was seen in CD4+, CD8+ and natural killer (NK) cells in PBMC from children with AD . Our findings indicate that reduced production of IFN-gamma observed in childhood AD is due to both a decrease in the number of IFN-gamma-producing cells and a reduced amount of IFN-gamma production per cell . Furthermore, we found that this defect was not confined to CD4+ T cells, suggesting a more generalized defect in IFN-gamma production in childhood AD.

Enferm Infecc Microbiol Clin, 1999 Feb, 17(2), 56 - 64
{Bacteremia by Staphylococcus aureus: analysis of 311 episodes}; Rubio M et al.; BACKGROUND: The aim of this study was to set up the differences between nosocomial and community acquired S . aureus bacteremia, to identify the features of the patients at high risk of endocarditis and to define the characteristics of the patients with methicillin resistant S . aureus (MRSA) . METHODS: We prospectively studied 311 cases of S . aureus bacteremia detected at our hospital during a four-year period . RESULTS: Nosocomial acquisition of bacteremia was found in 63% of the cases, 45% of which were caused by MRSA . Nosocomial bacteria generally presented in older patients with more severe underlying conditions and a higher prevalence of invasive procedures than patients with the community-acquired disease . Likewise, the primary focus of infection was identifiable in most of the nosocomial episodes and mortality was also higher . Endocarditis presented in 19% of the bacteremia episodes and almost 90% of patients with endocarditis were intravenous drug users (IDU) . The risk of endocarditis in this group was 64% whereas it was only 3% in non-IDU patients . Overall mortality was 33% and mortality directly due to the bacteremia was 22% . CONCLUSIONS: IDU patients were at high risk of endocarditis but most had a favourable outcome . Bacteremia was community-acquired in these patients and they rarely presented MRSA bacteremia . Patients with previous valvular diseases were at high risk of endocarditis and had a high mortality . Non-IDU patients with community-acquired bacteremia were at a low risk of endocarditis, regardless of whether a primary focus of infection had been identified or not . Mortality was lower in this group than in patients with nosocomial bacteremia and there were no cases of MRSA bacteremia . Mortality was higher in patients treated with vancomycin than in patients treated with other antibiotics active against S . aureus.

J Infect Dis, 1999 May, 179(5), 1157 - 61
Recurrent Staphylococcus aureus bacteremia: pulsed-field gel electrophoresis findings in 29 patients; Fowler VG Jr et al.; To identify risk factors for relapse among 309 prospectively identified cases of Staphylococcus aureus bacteremia, patients with recurrent S . aureus bacteremia were identified, and pulsed-field gel electrophoresis (PFGE) was performed on isolates from both episodes . PFGE banding patterns from both isolates were identical in 23 patients, consistent with relapsed infection . Patients with PFGE-confirmed relapse were more likely by both univariate and multivariate analyses to have an indwelling foreign body (odds ratio {OR}=18.2, 95% confidence interval {CI}=7 . 6-43.6; P<.001), to have received vancomycin therapy (OR=4.1, 95% CI=1.5-11.6; P=.008), or be hemodialysis-dependent (OR=4.1, 95% CI=1 . 8-9.3; P=.002) than patients who did not develop recurrent bacteremia . These results suggest that recurrent episodes of S . aureus bacteremia are primarily relapses and are associated with an indwelling foreign body, receiving vancomycin therapy, and hemodialysis dependence.

Surg Today, 1999, 29(3), 280 - 3
Conservative management of a methicillin-resistant Staphylococcus aureus (MRSA)-infected aortobifemoral graft: report of a case; Nakazawa T et al.; A 63-year-old man was referred to our department for treatment of intermittent claudication in the right lower limb . The preoperative angiogram showed severe stenosis extending from the terminal aorta to the bilateral common femoral arteries, with occlusion of the right superficial femoral artery and the left popliteal artery . He underwent aortobifemoral bypass with thromboendarterectomy of the left common femoral artery, and right graft-popliteal artery bypass . The patient had an uneventful postoperative course; however, 14 days after the operation, a pulsatile mass suddenly appeared in the left groin . Emergency surgery revealed disruption of the left distal anastomosis of the aortobifemoral bypass and therefore, revision, in the form of graft-profunda femoris artery interposition with graft-superficial femoral artery bypass, was performed . Microscopic examination showed colonies of bacteria in the host artery adventitia adjacent to the anastomosis . Culture of the discharge from the right groin operative scar revealed methicillin-resistant Staphylococcus aureus (MRSA) . The discharge resolved following the intravenous administration of vancomycin and the local application of vancomycin ointment . There were no operative complications other than the MRSA infection, and the patient was discharged 20 days after revision surgery . In the 14 months since the revision, all grafts have remained patent and there have been no further symptoms of graft infection.

Acta Orthop Scand, 1999 Feb, 70(1), 47 - 50
No influence of large volume blood loss on serum vancomycin concentrations during orthopedic procedures; Klekamp JW et al.; We prospectively studied orthopedic patients with either large or small blood loss who also received vancomycin prophylaxis to determine the effect of intraoperative volume shifts on serum vancomycin concentrations . There were 6 index patients in the large blood loss group (greater than 2 L), and 7 in the control group (less than 2 L) . Mean estimated blood loss for index and controls was 4.4 L and 1.0 L, respectively . Mean intraoperative fluid resuscitation, excluding blood products, was 12.4 L and 5.1 L, respectively . There was a modest inverse correlation between blood loss and intraoperative serum half-life of vancomycin . Although controls maintained slightly higher intraoperative vancomycin concentrations at each time-point, there was no statistically significant difference between the groups with regard to absolute concentrations or rate of decline . After 8 hours, the serum vancomycin concentration exceeded the MIC-90 for Staphylococcus aureus by approximately eightfold in all but one case patient . This was a morbidly obese patient with massive blood loss . Thus, blood loss during orthopedic procedures has minimal effects on intraoperative kinetics of vancomycin . Redosing is rarely indicated, although a preoperative 1.5 gram-dose should be considered for patients weighing more than 90 kg.

Gen Physiol Biophys, 1998 Dec, 17(4), 349 - 63
Channel-sizing experiments in multichannel bilayers; Krasilnikov OV et al.; The possibility of obtaining information about the radius of high and low conductance states of channels in multichannel membranes was tested experimentally . In spite of the interference of non-electrolytes on the numbers of channels that appeared in the membrane, the non-electrolyte-exclusion method was successfully adapted to multichannel bilayers to estimate the radius of the larger opening of the low conductance state of the channel induced by Staphylococcus aureus alpha-toxin . At the pH used, the channel transition to a low conductance state was accompanied by a decrease of the opening radius from 1.3 +/- 0.2 nm to 0.9 +/- 0.1 nm . The determination criteria for maximum size of a channel opening when using the non-electrolyte exclusion method is discussed.

FEMS Microbiol Lett, 1999 Mar 15, 172(2), 247 - 53
Antiseptic susceptibility and distribution of antiseptic-resistance genes in methicillin-resistant Staphylococcus aureus; Noguchi N et al.; We examined the antiseptic susceptibilities and distribution of antiseptic-resistance genes qacA and smr in 98 isolates of methicillin-resistant Staphylococcus aureus obtained in 1992 . Seventy-one strains were resistant to antiseptics . The qacA and smr genes were detected in 10 and 20 strains, respectively . The remaining 41 strains without qacA and smr were divided into two groups that exhibited low-level (n = 22) and high-level (n = 19) resistance to acriflavin . DNA cloning and sequencing suggested that norfloxacin-resistance gene norA was responsible for the high-level resistance to acriflavin . Our results indicated that four or more antiseptic-resistance genes exist in methicillin-resistant S . aureus and that antiseptic-resistant methicillin-resistant S . aureus strains without qacA and smr are widely spread in Japan.

FEMS Microbiol Lett, 1999 Mar 15, 172(2), 173 - 7
Shift-down in growth rate rather than high cell density induces toxic shock syndrome toxin-1 gene expression in Staphylococcus aureus; Timmins BS et al.; A luciferase-based reporter system for the expression of the toxic shock syndrome toxin-1 gene (tst) of Staphylococcus aureus FRI 1187 was used in continuous culture to determine whether high cell density on transient shift-down or shift-up of specific growth rate (mu) induced expression of tst . Little expression occurred at steady state at a low dilution rate (D) and in a transient period of increasing mu . However, a rapid and approximately 130-fold increase in expression occurred during a transient shift-down of mu . These findings suggest reduction of mu is a key element in the control of tst expression.

Antimicrob Agents Chemother, 1999 Apr, 43(4), 990 - 2
Growth in the presence of salicylate increases fluoroquinolone resistance in Staphylococcus aureus; Gustafson JE et al.; Salicylate and acetylsalicylate slightly increased fluoroquinolone resistance in ciprofloxacin-susceptible and -resistant Staphylococcus aureus . Salicylate allowed a greater number of cells from ciprofloxacin-susceptible and -resistant strains to survive on high fluoroquinolone concentrations . Salicylate also increased the frequency with which a susceptible strain mutated to become more resistant to ciprofloxacin.

Antimicrob Agents Chemother, 1999 Apr, 43(4), 966 - 8
In vitro activities of 13 fluoroquinolones against Staphylococcus aureus isolates with characterized mutations in gyrA, gyrB, grlA, and norA and against wild-type isolates; Munoz Bellido JL et al.; The in vitro activities of 13 fluoroquinolones (FQs) were tested against 90 Staphylococcus aureus clinical isolates: 30 wild type for gyrA, gyrB, grlA and norA and 60 with mutations in these genes . Clinafloxacin (CI-960), sparfloxacin, and grepafloxacin were the most active FQs against wild-type isolates (MICs at which 90% of isolates were inhibited, 0.06 to 0.1 microgram/ml) . Mutations in grlA did not affect the MICs of newer FQs . grlA-gyrA double mutations led to higher MICs for all the FQs tested . Efflux mechanisms affected the newer FQs to a much lesser extent than the less recently developed FQs.

Antimicrob Agents Chemother, 1999 Apr, 43(4), 925 - 9
A new resistance gene, linB, conferring resistance to lincosamides by nucleotidylation in Enterococcus faecium HM1025; Bozdogan B et al.; Resistance to lincomycin and clindamycin in the clinical isolate Enterococcus faecium HM1025 is due to a ribosomal methylase encoded by an ermAM-like gene and the plasmid-mediated inactivation of these antibiotics . We have cloned and determined the nucleotide sequence of the gene responsible for the inactivation of lincosamides, linB . This gene encodes a 267-amino-acid lincosamide nucleotidyltransferase . The enzyme catalyzes 3(5'-adenylation) (the adenylation of the hydroxyl group in position 3 of the molecules) of lincomycin and clindamycin . Expression of linB was observed in both Escherichia coli and Staphylococcus aureus . The deduced amino acid sequence of the enzyme did not display any significant homology with staphylococcal nucleotidyltransferases encoded by linA and linA' genes . Sequences homologous to linB were found in 14 other clinical isolates of E . faecium, indicating the spread of the resistance trait in this species.

Am J Emerg Med, 1999 Mar, 17(2), 121 - 4
Low- versus high-pressure irrigation techniques in Staphylococcus aureus-inoculated wounds; Pronchik D et al.; Current teaching emphasizes the importance of high-pressure (5 to 8 pounds per square inch {psi}) irrigation of traumatic wounds . The purpose of this study was to compare the irrigation efficacy, in an animal wound model, of the traditional higher-pressure, lower-volume (HPLV) syringe and catheter method of wound irrigation with a novel lower-pressure, higher-volume (LPHV) "port" method of irrigation . Experimental rat wounds were inoculated and incubated for 1 to 5 hours with a pathogenic strain of Staphylococcus aureus bacteria, then irrigated with one of the two methods . Irrigation times, mean irrigation pressures, and bacterial removal of the two techniques were compared . LPHV irrigation times were one third those of the HPLV . Mean irrigation pressures were 8.8 psi for HPLV and 1.6 psi for LPHV . HPLV and LPHV were found to be equally effective at washing out bacteria from the inoculated wounds at all times studied.

Biosens Bioelectron, 1999 Feb, 14(2), 163 - 70
Detecting staphylococcal enterotoxin B using an automated fiber optic biosensor; King KD et al.; The Man-portable Analyte Identification System (MANTIS), the first fully automated, self-contained, portable fiber optic biosensor, was utilized for the detection of Staphylococcal Enterotoxin B (SEB), a bacterial toxin produced by Staphylococcus aureus that commonly causes food poisoning . Because of its remarkable toxicity and stability, SEB is considered a prime threat as a biological weapon of mass destruction . The assay for SEB was used to evaluate the MANTIS' ability to function in the presence of various environmental interferents . The sensor could reliably detect SEB spiked into liquid samples containing a variety of smoke particles . However, substantial interference occurred when SEB was mixed into matrices capable of adsorbing SEB, such as 1% solutions of clay, topsoil, or pollen . Of equal importance, none of the interferents produced false positives in the MANTIS . The MANTIS demonstrated the capability to perform simultaneous immunoassays rapidly in the field with little or no user intervention.

Int J Food Microbiol, 1999 Feb 18, 46(3), 271 - 4
Restriction fragment length polymorphisms analysis by pulsed-field gel electrophoresis for discrimination of Staphylococcus aureus isolates from foodborne outbreaks; Suzuki Y et al.; A number of outbreaks of disease due to Staphylococcus aureus occurring in Aichi-ken, Japan, have provided the opportunity to investigate aspects of the molecular epidemiology of this and related organisms . Coagulase types, enterotoxin types, phage types, and restriction fragment length polymorphisms (RFLPs) as assessed by pulsed-field gel electrophoresis (PFGE) was performed for S . aureus infections diagnosed in the area of Aichi-ken . Among the 56 isolates of S . aureus from 30 outbreaks, 15 distinctive RFLP types were found by digestion with the restriction enzyme, SmaI . A total of 32 isolates from patients, foodstuffs and cooks on six occasions had the same RFLP types, coagulase types, enterotoxin types and phage types in the same outbreaks . Moreover, the coagulase and phage types could be separated in terms of RFLP . In one outbreak, ten isolates, which were derived from six patients, two foodstuffs and two cooks, had the same coagulase type, enterotoxin type, phage type, and RFLP type . This PFGE method may therefore prove useful for subclassifying S . aureus and differentiating isolates of the same coagulase types and phage types derived from sporadic cases and those derived from foodborne outbreaks.

Microbiol Immunol, 1999, 43(1), 19 - 27
The hsp operons are repressed by the hrc37 of the hsp70 operon in Staphylococcus aureus; Kuroda M et al.; The heat-shock proteins are coded for the polycistronic operons hsp70 and hsp60 in Staphylococcus aureus . The hsp70 operon is comprised of five genes, hrc37, hsp20, hsp70, hsp40 and orf35, and the hsp60 is comprised of two genes, hsp10 and hsp60 . The hsp70 operon transcribed five different sizes of mRNA from three promoters: P1, the most active promoter, transcribed 6.0 and 3.6 kb mRNAs; P2 transcribed a single 1.8 kb mRNA; and P3 transcribed 4.2 and 2.4 kb mRNAs . The hsp60 operon transcribed a single 2.1 kb transcript from only one promoter, P1 . Both operons had a common structure of inverted repeat element (CIRCE, Controlling Inverted Repeat of Chaperon Expression) at the promoter region . All of the transcripts were heat (46 C) inducible . One of the unidentified genes, hrc37, was characterized . The disruptant of the hrc37 in the hsp70 operon enhanced the transcription of both operons at 37 C (derepression) . Complementation of the disruptant with the cloned hrc37 plasmid recovered the repression of the transcription of both operons at 37 C . The product of hrc37, Hrc37, was found to bind to the CIRCE element . These findings indicated that Hrc37 from the hsp70 operon repressed the transcription of both the hsp70 and hsp60 operons by binding to the CIRCE element located at the promoter region.

Infect Control Hosp Epidemiol, 1999 Mar, 20(3), 202 - 5
Regional dissemination and control of epidemic methicillin-resistant Staphylococcus aureus . Manitoba Chapter of CHICA-Canada; Nicolle LE et al.; A methicillin-resistant Staphylococcus aureus (MRSA) strain introduced into the largest tertiary-care teaching hospital in Manitoba in 1993 led to a sustained outbreak with secondary outbreaks at one community hospital, two large long-term-care facilities, and nosocomial transmission at a second teaching hospital . Control measures were consistent at each institution and were coordinated on a province-wide basis . MRSA is not currently endemic in any facility in the province.

Am J Ther, 1998 Jul, 5(4), 213 - 20
Ciprofloxacin resistance in methicillin-resistant Staphylococcus aureus: associated factors and resistance to other antibiotics; Hershow RC et al.; At the University of Illinois Hospital, antibiotic susceptibility testing was retrospectively performed on 254 stored clinical methicillin-resistant Staphylococcus aureus (MRSA) isolates cultured from 1985 through 1990 to characterize resistance to ciprofloxacin and other antibiotics . In case-control analyses, inpatients with and without ciprofloxacin-resistant strains were compared . Ciprofloxacin-resistance increased from 7% before 1988 to 83% in 1990 . A sudden increase in resistance to trimethoprim-sulfamethoxazole also occurred in 1988, and by 1990, 65% of strains were resistant to both antibiotics . In 95 patients with recent MRSA isolation (70 acquired nosocomially, 25 acquired in the community), ciprofloxacin resistance was more common in the nosocomial group (80% v 60%, P < 0.05) . In that group, no host or in-hospital factors were associated with ciprofloxacin resistance . Among community cases, a greater proportion with ciprofloxacin-resistant MRSA had diabetes mellitus (60% v 0%, P = 0 . 002) . Thus, with use, ciprofloxacin resistance emerged rapidly in MRSA and developed particularly among strains resistant to trimethoprim-sulfamethoxazole . Combined resistance to these antibiotics, uncommon in previous reports, severely limits oral therapy as an option for MRSA carriage or infection.

Mol Cell Biochem, 1999 Jan, 190(1-2), 75 - 8
A phosphorus-31 nuclear magnetic resonance study on the complex of chicken gizzard myosin subfragment 1 with adenosine diphosphate; Tanokura M et al.; The complex of Mg-ADP with chicken gizzard myosin subfragment 1 (S1), obtained by the treatment with Staphylococcus aureus V8 proteinase, was observed with 31P NMR at various temperatures between 0 and 25 degrees C . The signal of S1.ADP complex was observed at -2 to -3 ppm as a rather broad peak . As compared with the results for rabbit skeletal muscle S1.ADP complex (Tanokura M, Ebashi S: J Biochem 113: 19-21, 1993), the signal was assigned to beta-phosphate of ADP in the S1.ADP complex . The signal of the complex was so broad and weak that the dependences on temperature and magnetic field strength were not clear . The observation suggests the tight interaction of S1 with the phosphate moieties of ADP in the complex and the extremely anisotropic distribution of electrons around phosphorus nuclei.

Br J Cancer, 1999 Mar, 79(7-8), 1042 - 8
Constitutive expression of CD26/dipeptidylpeptidase IV on peripheral blood B lymphocytes of patients with B chronic lymphocytic leukaemia; Bauvois B et al.; We have investigated the expression of the ectoenzyme dipeptidylpeptidase IV (DPP IV)/CD26 on lymphocytes obtained from patients with B chronic lymphocytic leukaemia (B-CLL) and compared it with healthy subjects . Using two-colour immunofluorescence analysis with CD26 and CD20 or CD23 monoclonal antibodies, CD26 was found undetectable on peripheral resting B-cells (CD20+ CD23-) from normal donors whereas it was expressed on B-cells activated in vitro with interleukin (IL)-4 and Staphylococcus aureus strain cowan I (CD20+ CD23+) . The expression of CD26 on leukaemic B-cells (CD20+ CD23+) was clearly induced in 22 out of 25 patients examined . Consequently, induced levels of CD26 cell surface expression on either normal activated and malignant B-cells coincided with the enhancement of DPP IV activity detected on the surface of these cells . Reverse transcription polymerase chain reaction analyses showed that the transcript levels of the CD26 gene was higher in normal activated B-cells and B-CLL cells than in resting B-cells, suggesting that CD26 was expressed at the level of transcriptional activation . These observations provide evidence of the abnormal expression of DPPIV/CD26 in B-CLL which, therefore, may be considered as a novel marker for B-CLL . Further investigation in relation to CD26 expression and other B malignancies needs to be defined.

J Dermatol Sci, 1999 Feb, 19(2), 134 - 8
Reduced amount of secretory component of IgA secretion in tears of patients with atopic dermatitis; Toshitani A et al.; Coupled with the previous finding that sIgA excretion was reduced onto the surface of the skin, we demonstrated that sIgA secretion in the tears of patients with atopic dermatitis (AD) was significantly lower than that of normal subjects, using a small stick made of nitrocellulose membrane . In the bacterial cultures, we have also detected a higher frequency of Staphylococcus aureus in the tears from patients with AD compared to normal subjects . These findings suggested reduced sIgA secretion on the mucous membrane might play a crucial role in the pathomechanisms of the ocular lesions, such as abnormal bacterial flora and ocular complications as well as the establishment of skin lesions in AD.

Yonsei Med J, 1998 Dec, 39(6), 587 - 94
Epidemiological typing of methicillin-resistant Staphylococcus aureus outbreak isolates by pulsed-field gel electrophoresis and antibiogram; Kim EC et al.; Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common nosocomial pathogens . In April 1997, there were five MRSA-infected patients among 16 patients in the Neonatal Intensive Care Unit (NICU), Seoul National University Hospital, which is a tertiary-care hospital with 1,500 beds . The infections had spread from twin patients with MRSA who had transferred from Hospital C . MRSA was isolated from the axilla of 15 (94%) of the 16 patients, including the two patients with obvious infections . Three (19%) of 16 doctors and nine (30%) of 30 nurses had MRSA colonization of the anterior nares . Six different PFGE patterns (A through F) were identified in the 53 isolates of MRSA tested . Twelve of 13 isolates from infected sites of five patients showed pattern F . Three MRSA strains obtained from hospital C showed closely or possibly related pattern F . MRSA of type F was isolated from three of 16 patients' axilla, and one of 3 doctors' and three of 30 nurses' nasal swabs . The antibiogram code for 12 of 13 MRSA isolates from five infected patients was 66,754 . PFGE patterns of these isolates were either F, F1, F2 or Fa . Only one of three strains isolated from clinical specimens of patients in Hospital C showed the antibiogram code 66754, although they were all PFGE types F1 and Fa . In conclusion, the presumptive sources of the outbreak of MRSA infection in NICU were the twin patients transferred from hospital C . Antibiogram correlated reasonably well to the PFGE type . An effective notification system is needed when a MRSA-infected patient is transferred to another hospital to control the spread of the infection.

Yonsei Med J, 1998 Dec, 39(6), 526 - 33
Acquisition of methicillin resistance and progression of multiantibiotic resistance in methicillin-resistant Staphylococcus aureus; Ito T et al.; Methicillin-resistant Staphylococcus aureus (MRSA) produces specific penicillin-binding protein, PBP2', which shows remarkably low affinities to most beta-lactam antibiotics except those such as penicillin G and ampicillin . The region surrounding mecA has been called additional DNA or mec and is thought to be of extraspecies origin . From the study of mec, we found that mec is a novel mobile genetic element and designated as staphylococcal cassette chromosome mec (SCCmec) . There are three types of SCCmec . In the past decades, MRSA has become resistant to many antibiotics, such as carbapenems, new quinolones, and minocycline etc . It seems to be a characteristic of MRSA to acquire multi-resistance by accumulating multiple resistance genes around the mecA gene inside SCCmec.

Zentralbl Bakteriol, 1999 Feb, 289(1), 37 - 46
Increased typability of multiresistant Staphylococcus aureus by reverse phage typing; Ben-Yaakov M et al.; Sixty percent of Staphylococcus aureus isolates from patients in Israeli hospitals proved to be non typable by the conventional phage typing method . Heat pretreatment improved typability only to 54% while reverse typing increased typability to 75% . In general isolates typable by conventional phages belonged to group V, II, III, I, or to mixed groups . While isolates typable only by reverse typing belonged to group III, II, the extended group III + IIIa, or to mixed groups, but seldom to group I . Although most isolates were resistant to penicillin G, only one half were resistant to other antibiotics as well . While one third of these isolates could by typed by conventional phage typing, typability was significantly improved to over 80%, by the use of reverse typing as the additional typing method . Two main groups of oxacillin resistant isolates were identified . The partial resistant group consisting of isolates resistant to penicillin G and oxacillin with no or few other resistances . These isolates were mostly typable by conventional phage typing (group V) and dominated in the first study period (1989-1990) but were only seldom isolated in the second one (1991-1992) . The multiresistant group consisted of isolates resistant to penicillin G and oxacillin accompanied by resistances to 3-5 other antibiotics (chloramphenicol, clindamycin, erythromycin, gentamicin and tetracycline) . These isolates were mostly typable by reverse typing (the extended group III + IIIa) and showed no change in isolation frequencies during the entire study period . Reverse typing is proposed by us as a typing tool for these multiresistant S . aureus isolates.

J Photochem Photobiol B, 1998 Dec, 47(2-3), 202 - 10
Photosensitization of Staphylococcus aureus with malachite green isothiocyanate: inactivation efficiency and spectroscopic analysis; Golding PS et al.; The potential of malachite green isothiocyanate as a photosensitizer for the inactivation of bacteria has been evaluated . Samples of Staphylococcus aureus are treated with the dye and exposed to continuous-wave red light from a filtered xenon lamp . Reduction in cell viability is seen to increase with radiation dose, whilst non-photosensitized samples are largely unaffected with exposure . The mechanism of photosensitization and the subsequent inactivation is addressed . UV-Vis and Fourier-transform infrared absorption spectrometry have been applied to this biological system, revealing the rapid hydrolysis of the isothiocyanate group of the dye and the transition to the colourless carbinol base when in solution . On binding to Staphylococcus aureus via a complexation mechanism, the dye is seen to be stabilized in its cationic form . Involvement of the excited triplet state of the photosensitizer is suggested and identification of reduced dye photoproducts is made following irradiation.

Diagn Microbiol Infect Dis, 1999 Mar, 33(3), 201 - 3
Evaluation of a rapid slide agglutination test for identification of Staphylococcus aureus; Papasian CJ et al.; This study compared the Staph Latex Kit (Remel) with two other rapid agglutination tests (Staphaurex Plus (Murex) and Staphyloslide (Becton Dickinson Microbiological Systems)) and the tube coagulase test . The Staph Latex Kit, Staphaurex Plus, Staphyloslide, and Tube Coagulase correctly identified 98.4%, 100%, 99.5%, and 99.5%, of 191 staphylococcal isolates, respectively.

J Immunol, 1999 Mar 15, 162(6), 3231 - 6
Final maturation of dendritic cells is associated with impaired responsiveness to IFN-gamma and to bacterial IL-12 inducers: decreased ability of mature dendritic cells to produce IL-12 during the interaction with Th cells; Kalinski P et al.; Activation of immature CD83- dendritic cells (DC) in peripheral tissues induces their maturation and migration to lymph nodes . Activated DC become potent stimulators of Th cells and efficient inducers of Th1- and Th2-type cytokine production . This study analyzes the ability of human monocyte-derived CD1a+ DC at different stages of IL-1 beta and TNF-alpha-induced maturation to produce the major Th1-driving factor IL-12 . DC at the early stages of maturation (2 and 4 h) produced elevated amounts of IL-12 p70 during interaction with CD40 ligand-bearing Th cells or, after stimulation with the T cell-replacing factors, soluble CD40 ligand and IFN-gamma . The ability to produce IL-12 was strongly down-regulated at later time points, 12 h after the induction of DC maturation, and in fully mature CD83+ cells, at 48 h . In contrast, the ability of mature DC to produce IL-6 was preserved or even enhanced, indicating their intact responsiveness to CD40 triggering . A reduced IL-12-producing capacity of mature DC resulted mainly from their impaired responsiveness to IFN-gamma, a cofactor in CD40-induced IL-12 p70 production . This correlated with reduced expression of IFN-gamma R (CD119) by mature DC . In addition, while immature DC produced IL-12 and IL-6 after stimulation with LPS or Staphylococcus aureus Cowan I strain, mature DC became unresponsive to these bacterial stimuli . Together with the previously described ability of IL-10 and PGE2 to stably down-regulate the ability to produce IL-12 in maturing, but not in fully mature, DC, the current data indicate a general resistance of mature DC to IL-12-modulating factors.

J Biol Chem, 1999 Apr 2, 274(14), 9193 - 9
Importance of the carboxyl terminus in the folding and function of alpha-hemolysin of Staphylococcus aureus; Sangha N et al.; The physical state of two model mutants of alpha-hemolysin (alphaHL), alphaHL(1-289), a carboxyl-terminal deletion mutant (CDM), and alphaHL(1-331), a carboxyl-terminal extension mutant (CEM), were examined in detail to identify the role of the carboxyl terminus in the folding and function of native alphaHL . Denatured alphaHL can be refolded efficiently with nearly total recovery of its activity upon restoration of nondenaturing conditions . Various biophysical and biochemical studies on the three proteins have revealed the importance of an intact carboxyl terminus in the folding of alphaHL . The CDM exhibits a marked increase in susceptibility to proteases as compared with alphaHL . alphaHL and CEM exhibit similar fluorescence emission maxima, and that of the CDM is red-shifted by 9 nm, which indicates a greater solvent exposure of the tryptophan residues of the CDM . In addition, the CDM binds 8-anilino-1-naphthalene sulfonic acid (ANS) and increases its fluorescence intensity significantly unlike alphaHL and CEM, which show marginal binding . The circular dichroism studies point that the CDM possesses significant secondary structure, but its tertiary structure is greatly diminished as compared with alphaHL . These data show that the CDM has several of the features that characterize a molten globule state . Experiments with freshly translated mutants, using coupled in vitro transcription and translation, have further supported our observations that deletion at the carboxyl terminus leads to major structural perturbations in the water-soluble form of alphaHL . The studies demonstrate a critical role of the carboxyl terminus of alphaHL in attaining the native folded state.

Biochemistry, 1999 Mar 23, 38(12), 3778 - 84
Calponin binds to the 20-kilodalton regulatory light chain of myosin; Szymanski PT et al.; Calponin (CaP) is a 34 kDa smooth muscle-specific protein that has been implicated in regulation of smooth muscle contractility . Two CaP binding sites on smooth muscle myosin rod have been recently described {Szymanski and Tao (1997) J.Biol.Chem . 272, 11142-11146} . We used a combination of cosedimentation, overlay, and fluorescence assays to determine the interaction between CaP and both subfragment 1 of myosin and isolated 20 kDa regulatory light chain of myosin (RLC) . Subfragment 1, which was generated by cleavage of myosin with Staphylococcus aureus protease (myosin S1SA) inhibits cosedimentation of CaP with myosin filaments . Fluorescence assay showed that CaP labeled with fluorescent label (DAN-CaP) interacts with myosin S1SA in solution via a single class of binding sites . The binding constant (kaff) of this interaction at 50 mM NaCl is (2 . 1 +/- 0.2) x 10(6) M-1 (n = 3) . The interaction between DAN-CaP and myosin S1SA depends on ionic strength, and the EC50 of inhibition of this interaction occurs at about 130 mM NaCl . In contrast, the subfragment 1 that was generated by papain digestion (myosin S1PA), which cleaves RLC 4 kDa away from the NH2-terminal end of the molecule, does not interact with DAN-CaP . Overlay and fluorescent assay in solution showed that CaP binds to isolated RLC, suggesting that the interaction between CaP and subfragment 1 of myosin is due to a direct binding of CaP to RLC . CaP binding to myosin S1SA is stronger than to subfragment 2 in physiological salt concentrations . CaP binding to myosin head strengthened upon phosphorylation of RLC by Ca2+/calmodulin-dependent myosin light chain kinase . We suggest that CaP binds to subfragment 1 of myosin, exclusively via the NH2-terminal end of RLC, and this interaction could play a role in regulation of the actin-myosin interaction in smooth muscle contractility.

Acta Crystallogr D Biol Crystallogr, 1999 Feb, 55 ( Pt 2), 554 - 6
Crystallization of ClfA and ClfB fragments: the fibrinogen-binding surface proteins of Staphylococcus aureus; Deivanayagam CC et al.; Recombinant constructs encoding the fibrinogen-binding domains of ClfA and ClfB from Staphylococcus aureus have been crystallized . ClfA was crystallized in the orthorhombic space group P212121 with unit-cell parameters a = 39.58, b = 81.39 and c = 112.65 A . A complete data set was recorded to 2.1 A resolution and had a Vm of 2 . 3 A3 Da-1 with 46.5% solvent, suggesting one molecule per asymmetric unit . Co-crystals of ClfA with the 17 amino-acid C-terminal peptide of fibrinogen gamma-chain diffracted to 2.1 A resolution and had unit-cell parameters a = 39.11, b = 81.39 and c = 109.51 A in the space group P212121 . ClfB was crystallized in the tetragonal space group P41212 or P43212 with unit-cell parameters a = 96.31, b = 96 . 31 and c = 84.13 A and diffracted to 2.45 A resolution . The estimated Vm of 2.6 A3 Da-1 with 53% solvent indicated one molecule in the asymmetric unit.

Acta Crystallogr D Biol Crystallogr, 1999 Feb, 55 ( Pt 2), 525 - 7
Crystallization and preliminary X-ray analysis of B-domain fragments of a Staphylococcus aureus collagen-binding protein; Deivanayagam CC et al.; Recombinant proteins of monomeric and dimeric B-domain repeats of a Staphylococcus aureus FDA 574 collagen-binding adhesin have been crystallized . The single repeat unit (B1) was crystallized in a body-centered orthorhombic lattice with a = 96.9, b = 101.3, c = 120 . 8 A in either the I222 or I212121 space group . These crystals diffracted to 2.5 A resolution and the calculated Vm values of 3.2 and 2.2 A3 Da-1 suggest the possibility of a dimer or a trimer in the asymmetric unit . The two-repeat fragment (B1B2) crystallized in the orthorhombic space group P212121 with cell dimensions a = 42.4, b = 79.4, c = 130.4 A and diffracted to 2.3 A resolution . For this species, the calculated Vm value of 2.2 A3 Da-1 indicates the presence of a monomer in the asymmetric unit.

Poult Sci, 1999 Mar, 78(3), 346 - 52
Induction of the delayed footpad and wattle reaction to killed Staphylococcus aureus in chickens; Zhu XY et al.; Two experiments were conducted to induce the delayed footpad reaction (DFR) to killed Staphylococcus aureus antigen . In Experiment 1, tracheal, cloacal, and choanal swabs were collected from chickens prior to sensitization with S . aureus to determine the carrier status of S . aureus . The second experiment compared the DFR to the delayed wattle reaction (DWR) . Chickens were subjected to single or multiple sensitizations in the neck with S . aureus antigen between 4 and 6 wk of age . One week later, birds were challenged with S . aureus either in the right footpad or wattle . The left footpad or wattle was injected with PBS . The thicknesses of the footpad or the wattle were measured up to 96 h postchallenge . The recoveries of S . aureus from the choanal slit and trachea were significantly higher than that of the cloaca (P < 0.001) . Birds of Experiment 1 showed a significant DFR (P < 0.0001) following intradermal challenge with killed S . aureus that was sustained through 48 h postchallenge with no difference in the DFR between carrier and noncarrier birds . In Experiment 2, the thicknesses of the footpad and wattle were significantly increased following challenge with S . aureus (P < 0.0001), with the footpad showing a greater response than the wattle (P < 0.001) . Three sensitizing dosages, as compared to two dosages, resulted in a less pronounced DFR and DWR (P < 0.02) . These results indicate that the DFR can be used as a delayed reaction model in the study of staphylococcosis in poultry.

J Food Prot, 1999 Mar, 62(3), 244 - 51
Isolation and detection of Listeria monocytogenes using fluorogenic and chromogenic substrates for phosphatidylinositol-specific phospholipase C; Restaino L et al.; The BCM Listeria monocytogenes detection system (LMDS) consists of a selective preenrichment broth (LMPEB), selective enrichment broth (LMSEB), selective/differential plating medium (LMPM), and identification on a confirmatory plating medium (LMCM) . The efficacy of the BCM LMDS was determined using pure cultures and naturally and artificially contaminated environmental sponges . The BCM LMPEB allowed the growth of Listeria and resuscitation of heat-injured L . monocytogenes . The BCM LMSEB, which contains the fluorogenic substrate 4-methylumbelliferyl-myo-inositol-1-phosphate and detects phosphatidylinositol phospholipase C (PI-PLC) activity, provided a presumptive positive test for the presence of pathogenic Listeria (L . monocytogenes and L . ivanovii) after 24 h at 35 degrees C . An initial inoculum of 10 to 100 CFU/ml of L . monocytogenes in BCM LMSEB yielded a fluorogenic response after 24 h . On BCM LMPM, L . monocytogenes and L . ivanovii were the two Listeria species forming turquoise convex colonies (1.0 to 2.5 mm in diameter) from PI-PLC activity on the chromogenic substrate, 5-bromo-4-chloro-3-indoxyl-myo-inositol-1-phosphate . L . monocytogenes was distinguished from L . ivanovii by either its fluorescence on BCM LMCM or acid production from rhamnose . False-positive organisms (Bacillus cereus, Staphylococcus aureus, Bacillus thuringiensis, and yeasts) were eliminated by at least one of the media in the BCM LMDS . Using a pure culture system, the BCM LMDS detected one to two L . monocytogenes cells from a sponge rehydrated in 10 ml of DE neutralizing broth . In an analysis of 162 environmental sponges from facilities inspected by the U.S . Department of Agriculture (USDA), the values for identification of L . monocytogenes by BCM LMDS and the USDA method were 30 and 14 sites, respectively, with sensitivity and specificity values of 85.7 and 100.0% versus 40.0 and 66.1%, respectively . No false-positive organisms were isolated by BCM LMDS, whereas 26.5% of the sponges tested by the USDA method produced false-positive results.

J Rheumatol, 1999 Mar, 26(3), 663 - 7
The clinical spectrum of severe septic bursitis in northwestern Spain: a 10 year study; Garcia-Porrua C et al.; OBJECTIVE: To assess the clinical and microbiological characteristics of septic bursitis in those cases that required treatment at the hospital during the past 10 years in a northwestern area of Spain . METHODS: The charts of all patients diagnosed as having septic bursitis at Hospital Xeral-Calde, Lugo, Spain, from October 1987 through September 1997 were reviewed based on published criteria and graded according to severity . RESULTS: Sixty-nine patients diagnosed with definite and 6 with probable septic bursitis met the criteria for severe septic bursitis . Sixty-two were male (82.7%) . The mean age at the time of diagnosis was 51 years . The most frequently involved sites were olecranon (47%) and prepatellar (44%) bursae . Among predisposing factors, the presence of prepatellar bursitis was correlated with a job that involved frequent trauma on the bursae . The main clinical and laboratory findings were cellulitis and/or erythema (94.7%), fever (77.3%), and leukocytosis (72%) . Noninflammatory synovial fluid (SF, < 2,000 leukocytes/mm3) was observed in 4/32 (12.5%) cases . Positive SF cultures were obtained in 69 of 75 patients (92%) . Staphylococcus aureus was the most common pathogen (84%) . Blood cultures were positive in 12 of 62 patients (19.4%) . Three patients had osteomyelitis . This complication was associated with a longer delay to diagnosis from the onset of symptoms (> 3 weeks vs 9.3+/-13.3 days for the group as a whole) . Apart from these 3 cases, overall outcome was excellent . CONCLUSION: Severe septic bursitis is a common disease . Local trauma is the most common risk factor for this infection . Although the most common pathogen is S . aureus, other pathogens such as Brucella abortus play an important role in this infection in our area.

Plasmid, 1999 Mar, 41(2), 120 - 4
Construction and analysis of a modified Tn4001 conferring chloramphenicol resistance in Mycoplasma pneumoniae; Hahn TW et al.; The Staphylococcus aureus transposon Tn4001 and derivatives thereof have been transformed successfully in several mycoplasma species . In order to expand the versatility of Tn4001 for other genetic manipulations and for use in mycoplasma species resistant to gentamicin (Gm), chloramphenicol acetyltransferase (Cat) from S . aureus was evaluated as a selectable marker . The cat gene was cloned in both orientations into a modified Tn4001 and transformed into Mycoplasma pneumoniae, conferring resistance to Cm and Gm . Replacement of the gene for GmR in Tn4001 with cat likewise conferred CmR when transformed into M . pneumoniae . The minimum inhibitory concentration to Cm in transformants with cat derivatives of Tn4001 was 300-500 microg/ml, and Cat enzyme activity was demonstrated by using a fluorescent substrate .

J Leukoc Biol, 1999 Feb, 65(2), 241 - 8
Trp-Lys-Tyr-Met-Val-D-Met stimulates superoxide generation and killing of Staphylococcus aureus via phospholipase D activation in human monocytes; Bae YS et al.; Among the phagocytic leukocytes, monocytes have the important role of clearing out parasitic microorganisms . They accomplish this through production of toxic metabolites of oxygen . Trp-Lys-Tyr-Met-Val-D-Met (WKYMVm), a peptide that stimulates phosphoinositide (PI) hydrolysis in human leukocytes, including monocytes, binds to a unique cell surface receptor and stimulates superoxide generation, killing of Staphylococcus aureus, and activation of phospholipase D (PLD) in human monocytes . Preincubation of the cells with a PI-specific phospholipase C (PLC) inhibitor (U-73122), protein kinase C inhibitor (GF109203X), or intracellular Ca2+ chelator (BAPTA/AM) before the peptide stimulus totally inhibits the peptide-induced PLD activation and superoxide generation . On the other hand, tyrosine kinase inhibitor genistein only partially inhibits the peptide-induced processes . The peptide-induced bacteria killing activity shares regulatory mechanisms for PLD activation with the superoxide generation, which is inhibited in the presence of 1-butanol . We suggest that the peptide stimulates PLD downstream of PLC activation and PLD activation in turn is essential for the peptide-induced immunological functions such as the superoxide generation and killing of bacteria by human monocytes.

Med Trop (Mars), 1998, 58(3), 297 - 306
{Tropical myositis}; Saissy JM et al.; Tropical pyomyositis (TP) is a microbial infection involving one or more skeletal muscles that rapidly leads to abscess . The most common infectious agent is Staphylococcus aureus . Since muscle tissue is highly resistant to infection, occurrence of TP is contingent upon one or more compromising factors such as trauma, skin lesions, parasitosis, or malnutrition . HIV infection is currently a major factor in the occurrence of TP . While Staphylococcus aureus accounts for 80% of cases, other microbial agents have been identified including gram-positive cocci and gram-negative bacilli . TP is endemic in intertropical zones of Africa and Latin America and in island areas of the Pacific Ocean . However a growing number of non-tropical cases have been reported in association with AIDS . The most frequent presentation is single-muscle involvement in the thighs, calves, and buttocks . The symptomatic phase or suppurative phase is almost always associated with hyperthermia . The infected muscle indurates prior to development of characteristic fluctuance . Hemocultures are seldom positive but needle aspiration may confirm diagnosis . Ultrasound imaging can allow early detection . Severe sepsis or cardiovascular, renal, or pleuropulmonary complications are observed in 10% of cases . Treatment is antibiotic therapy with penicillin M and surgical drainage or needle puncture of abscess cavities . Prognosis is generally favorable even in HIV-infected patients.

J Nucl Med, 1999 Mar, 40(3), 484 - 90
Pretargeting of bacterial endocarditis in rats with streptavidin and 111In-labeled biotin; Fogarasi M et al.; A radioimaging approach for the detection of endocarditis has been investigated using two-step pretargeting with streptavidin and radiolabeled biotin . METHODS: Hemodynamic alterations within the rat heart were induced by placing an in-dwelling catheter into the left ventricle through the aortic valves . The animals were subsequently infected with Staphylococcus aureus through a tail vein . After an incubation period, rats were first injected with streptavidin and, 2 h later, with 111In-labeled ethylene-diaminetetraacetic acid-biotin . Whole-body gamma camera images were taken 4-5 h postinjection of the radiolabeled biotin . Control animals consisted of catheterized but uninfected, infected but uncatheterized and normal untreated rats . As a further control, the labeled biotin was administered to a study animal without the preadministration of streptavidin . RESULTS: Histology showed typical endocarditic changes in the hearts of study animals with massive deposition of gram-positive cocci . Catheterized but uninfected animals showed alterations corresponding to nonbacterial thrombotic endocarditis . Macroautoradiography showed accumulation of radiolabel in the endocarditic vegetations of study animals . Whole-body gamma camera images showed important cardiac uptake in 7 of 8 catheterized and infected animals and in 3 of 6 catheterized but uninfected animals . Normal rats and those infected but not catheterized showed negative results by histology, autoradiography and imaging . The percent uptake of the injected dose in the heart was 0.20 (SD = 0.13) in catheterized and infected animals, 0.12 (SD = 0.10) in catheterized but uninfected animals, 0.10 (SD = 0.04) in infected but uncatheterized animals and 0.04 (SD = 0.01) in normal control animals . CONCLUSION: The two-step pretargeting approach using streptavidin and 111In-labeled biotin was used successfully to detect S . aureus-induced bacterial endocarditis in rats.

Ned Tijdschr Geneeskd, 1999 Jan 23, 143(4), 205 - 8
{Secondary infection with methacillin resistant Staphylococcus aureus in Dutch hospitals (July 1997-June 1996}; Esveld MI et al.; OBJECTIVE: To study the spread of methicillin-resistant Staphylococcus aureus (MRSA) in hospitals, especially secondary MRSA infections in relation to the origin of the MRSA strain and the measures taken regarding contact isolation . DESIGN: Secondary data analysis . METHODS: As part of the national MRSA surveillance of the National Institute of Public Health and the Environment, data were collected using questionnaires . The analysis covered the period July 1994-June 1996 and was performed for index cases of secondary infections versus sporadic cases . Possible risk factors were determined . RESULTS: In the study period 30 index cases of (clusters of) secondary infections and 191 sporadic cases were found . The size of the clusters was limited . Strict contact isolation as described in the guidelines of the Dutch Working Group on Infection Prevention prevented secondary infections in most cases . Patients for whom no relation could be found between the MRSA infection and a stay abroad were found to have caused more secondary infections, even when the data were corrected for contact isolation measures.

Dtsch Tierarztl Wochenschr, 1999 Feb, 106(2), 67 - 71
Effect of pesticide water pollution on some haematological, biochemical and immunological parameters in Tilapia nilotica fish; Khalaf-Allah SS; Nine groups of Tilapia nilotica fish each consisting of 50 fish were used to assess the effect of pesticides on the haematological, biochemical and immunological parameters in fish . Four groups were injected with 0.05 ml of Staphylococcus aureus antigen plus complete Freund's adjuvant, the first group (G1) was exposed to lindane treatment, the second (G2) was exposed to dialdrin, the third (G3) was exposed to diazinon and the forth group (G4) was exposed to malathion . Four other groups were not immunized, but injected with the adjuvant and exposed to the pesticides, the fifth group (G5) was exposed to lindane, the sixth (G6) was exposed to dialdrin, the seventh (G7) was exposed to diazinon and the eighth group (G8) was exposed to malathion . The ninth group (G9) was exposed to water without any pesticide treatment and served as controls . Both vaccinated and non-vaccinated groups were exposed to 1/10 LC50 of the tested pesticides for 30 days . The results revealed that the mean total RBCs, WBCs counts, PCV, Hb, MCV, MCH, MCHC values were lower in vaccinated groups than in the groups exposed to the tested pesticides . The total protein, globulin and serum enzymes ALAT; ASAT values as well as macrophage phagocytic index and antibody titer were lower in vaccinated as compared to the non-vaccinated groups.

J Biol Chem, 1999 Mar 26, 274(13), 8405 - 10
Inactivation of the dlt operon in Staphylococcus aureus confers sensitivity to defensins, protegrins, and other antimicrobial peptides; Peschel A et al.; Positively charged antimicrobial peptides with membrane-damaging activity are produced by animals and humans as components of their innate immunity against bacterial infections and also by many bacteria to inhibit competing microorganisms . Staphylococcus aureus and Staphylococcus xylosus, which tolerate high concentrations of several antimicrobial peptides, were mutagenized to identify genes responsible for this insensitivity . Several mutants with increased sensitivity were obtained, which exhibited an altered structure of teichoic acids, major components of the Gram-positive cell wall . The mutant teichoic acids lacked D-alanine, as a result of which the cells carried an increased negative surface charge . The mutant cells bound fewer anionic, but more positively charged proteins . They were sensitive to human defensin HNP1-3, animal-derived protegrins, tachyplesins, and magainin II, and to the bacteria-derived peptides gallidermin and nisin . The mutated genes shared sequence similarity with the dlt genes involved in the transfer of D-alanine into teichoic acids from other Gram-positive bacteria . Wild-type strains bearing additional copies of the dlt operon produced teichoic acids with higher amounts of D-alanine esters, bound cationic proteins less effectively and were less sensitive to antimicrobial peptides . We propose a role of the D-alanine-esterified teichoic acids which occur in many pathogenic bacteria in the protection against human and animal defense systems.

Chest, 1999 Mar, 115(3 Suppl), 34S - 41S
Nosocomial infections in the ICU: the growing importance of antibiotic-resistant pathogens; Weber DJ et al.; Patients hospitalized in ICUs are 5 to 10 times more likely to acquire nosocomial infections than other hospital patients . The frequency of infections at different anatomic sites and the risk of infection vary by the type of ICU, and the frequency of specific pathogens varies by infection site . Contributing to the seriousness of nosocomial infections, especially in ICUs, is the increasing incidence of infections caused by antibiotic-resistant pathogens . Prevention and control strategies have focused on methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus, and extended-spectrum beta-lactamase-producing Gram-negative bacilli, among others . An effective infection control program includes a surveillance system, proper handwashing, appropriate patient isolation, prompt evaluation and intervention when an outbreak occurs, adherence to standard guidelines on disinfection and sterilization, and an occupational health program for health-care providers . Studies have shown that patients infected with resistant strains of bacteria are more likely than control patients to have received prior antimicrobials, and hospital areas that have the highest prevalence of resistance also have the highest rates of antibiotic use . For these reasons, programs to prevent or control the development of resistant organisms often focus on the overuse or inappropriate use of antibiotics, for example, by restriction of widely used broad-spectrum antibiotics (e.g., third-generation cephalosporins) and vancomycin . Other approaches are to rotate antibiotics used for empiric therapy and use combinations of drugs from different classes.

Immunopharmacol Immunotoxicol, 1999 Feb, 21(1), 89 - 108
Ehrlich's ascites fluid adsorbed over protein A containing Staphylococcus aureus Cowan I produces inhibition of tumor growth; Verma AS et al.; Our earlier studies have shown that removal of various blocking factors from the sera of tumor-bearing animals and humans by adsorption over heat-attenuated and formalin-fixed-Staphylococcus aureus Cowan I (SAC) containing Protein A (PA) causes antitumor immune response . It was also shown that this procedure caused regression of a wide variety of established animal and human tumors . In the present investigation, the therapeutic potential of inoculation of ascites fluid adsorbed in vitro over non-viable SAC containing PA has been demonstrated in Ehrlich' s ascites tumor (EAT) in mouse . The antitumor effect was evident by a significant decrease in body weight (p<0.001) as well as significant reduction in viability of ascites tumor cells (p<0.001) in peritoneal cavity . However, some of the responding animals died earlier than controls, this may be due to the toxicity associated with therapy . The toxic effects were evident in decreased contents of glutathione, and increased activity of glutathione-S-transferase, decreased activity of microsomal enzymes and also in an early death of some of tumor regressed animals . The probable causes of toxicity of the therapy and prospects of reversing these toxic effects are discussed.

Planta Med, 1999 Feb, 65(1), 76 - 8
Chemical analysis and antimicrobial activity of the resin Ladano, of its essential oil and of the isolated compounds; Demetzos C et al.; Fractionation of the resin Ladano from Cistus creticus subsp . creticus and susceptibility testing using the chromatographic fractions showed that its antistaphylococcal activity was mainly due to the diterpene sclareol . The antimicrobial activity of its essential oil, of the chromatographic fractions, and of the isolated compounds was also evaluated against Staphylococcus aureus, Staphylococcus epidermidis, and Staphylococcus hominis.

Toxicon, 1999 Apr, 37(4), 651 - 60
TsTX-IV, a short chain four-disulfide-bridged neurotoxin from Tityus serrulatus venom which acts on Ca2+-activated K+ channels; Novello JC et al.; The primary structure of TsTX-IV, a neurotoxin isolated from Tityrus serrulatus scorpion venom, is reported . Its amino acid sequence was determined by automated Edman sequential degradation of the reduced and carboxymethylated toxin and of relevant peptides obtained by digestion with Staphylococcus aureus strain V8 protease or trypsin and cleavage by CNBr . The complete sequence showed 41 amino acid residues, which account for an estimated molecular weight of 4520, and eight half-cystine residues which cross-link the toxin molecule with four disulfide bonds . The molecular weight determined by mass spectrometry was 4518 . Comparison of this sequence with those from other scorpion toxins showed a resemblance with toxins which act on different types of K+ channels . TsTx-IV was able to block Ca2+-activated K+ channels of high conductance . TsTX-IV is the first four-disulfide-bridged short toxin from T . serrulatus so far completely sequenced.

Farmaco, 1998 Aug-Sep, 53(8-9), 541 - 4
Synthesis and antimicrobial activity of some 5-aryl-2-{N,N-disubstituted thiocarbamoylthio)acylamino}-1,3,4-oxadiazoles; Ates O et al.; In this study, a number of novel 5-aryl-2-{(N,N-disubstituted thiocarbamoylthio)acylamino}-1,3,4-oxadiazole derivatives were synthesized by the reaction of potassium salts of N,N-disubstituted dithiocarbamoic acids with 2-{(alpha-chloro-alpha-phenylacetyl/alpha-bromopropionyl)-amino}-5 -aryl-1, 3,4-oxadiazoles . Structures of the compounds were confirmed by the spectral data (IR, 1H NMR, EIMS) and elemental analyses . Most of the compounds were tested against various microorganisms and four of them were found to be weakly active against Staphylococcus aureus and Staphylococcus epidermidis.

Emerg Infect Dis, 1999 Jan-Feb, 5(1), 147 - 9
Staphylococcus aureus with reduced susceptibility to vancomycin isolated from a patient with fatal bacteremia; Rotun SS et al.; A Staphylococcus aureus isolate with reduced susceptibility to vancomycin was obtained from a dialysis patient with a fatal case of bacteremia . Comparison of the isolate with two methicillin-resistant S . aureus (MRSA) isolated obtained from the same patient 4 months earlier suggests that the S . aureus with reduced susceptibility to vancomycin emerged from the MRSA strain with which the patient was infected . Atypical phenotypic characteristics, including weak or negative latex-agglutination test results, weak or negative-slide coagulase test results, heterogeneous morphologic features, slow rate of growth, and vancomycin susceptibility (by disk diffusion test) were observed.

Emerg Infect Dis, 1999 Jan-Feb, 5(1), 9 - 17
The economic impact of Staphylococcus aureus infection in New York City hospitals; Rubin RJ et al.; We modeled estimates of the incidence, deaths, and direct medical costs of Staphylococcus aureus infections in hospitalized patients in the New York City metropolitan area in 1995 by using hospital discharge data collected by the New York State Department of Health and standard sources for the costs of health care . We also examined the relative impact of methicillin-resistant versus -sensitive strains of S . aureus and of community-acquired versus nosocomial infections . S . aureus-associated hospitalizations resulted in approximately twice the length of stay, deaths, and medical costs of typical hospitalizations; methicillin-resistant and -sensitive infections had similar direct medical costs, but resistant infections caused more deaths (21% versus 8%) . Community-acquired and nosocomial infections had similar death rates, but community-acquired infections appeared to have increased direct medical costs per patient ($35,300 versus $28,800) . The results of our study indicate that reducing the incidence of methicillin-resistant and -sensitive nosocomial infections would reduce the societal costs of S . aureus infection.

Cytokine, 1999 Jan, 11(1), 61 - 5
Influence of recombinant human erythropoietin on neutrophil function in premature neonates; Soubasi V et al.; The in vivo influence of recombinant human erythropoietin (rhEpo) and iron on human neutrophil (PMN) antimicrobial function was assessed . A total of 21 preterm infants were randomized to receive either 200 U/kg/other day of rHuEPO+12 mg/kg/day of iron (EPO+high Fe, seven infants) or 200 U/kg/other day of rhEPO+4 mg/kg/day of iron (EPO+standard Fe, 9 infants) or 4 mg/kg/day of iron only (standard Fe, five infants) . PMNs were isolated from blood of these infants 60+/-5 days after birth and from eight healthy adults . No differences between infants and adults were found in PMN random migration and chemotactic activity to N-formylmethionyl leucyl phenylalanine (FMLP), superoxide anion production in response to FMLP and phagocytosis of Staphylococcus aureus . In contrast, percentage phagocytosis was significantly lower in EPO+standard Fe as compared to both EPO+high Fe and standard Fe groups (P<0.01) . This modest impairment of phagocytic activity of neonatal PMNs found in association with administration of rhEPO and standard iron may be related to consumption of iron during rhEPO-enhanced erythropoiesis .

Acta Radiol, 1999 Mar, 40(2), 181 - 6
Thoracic CT findings in long-term hemodialysis patients; Coskun M et al.; PURPOSE: To evaluate thoracic CT findings of long-term hemodialysis patients . MATERIAL AND METHODS: Thoracic CT findings of 117 uremic patients (61 men, 56 women) with complaints of cough, dyspnea, low-grade pyrexia, malaise, weight loss, and profuse perspiration were retrospectively documented . RESULTS: Atelectasis (60%), cardiomegaly (60%), pleural effusion (51%), vascular congestion (44%), parenchymal consolidation (38%), parenchymal scarring-fibrosis (31%), and lymphadenopathy (29%) were the most common CT findings in the thoraces of the long-term hemodialysis patients . Staphylococcus aureus was detected in 13 patients (11%) who had parenchymal infiltration . Thoracic tuberculosis was identified in 15 patients (13%), 11 of these cases being confined to the lung parenchyma, 3 to the pleura, and 1 involving the pleura and pericardium . CONCLUSION: In patients under long-term hemodialysis treatment, parenchymal consolidation, secondary to infectious agents such as S . aureus and Mycobacterium tuberculosis, is the most important CT finding since these lesions can be detected and treated successfully if they are considered as etiologic factors early on.

J Chemother, 1999 Feb, 11(1), 46 - 9
Elution of vancomycin and tobramycin bonded to vascular grafts; Leblebicioglu H et al.; The elution of vancomycin and tobramycin from vascular grafts sealed with collagen and human blood was studied in vitro . The release of antibiotics was measured in three different types of soaked grafts, including grafts soaked with antibiotic after being sealed with albumin, those sealed with antibiotic and albumin mixture and those impregnated with fresh blood and antibiotic mixture . Each antibiotic was tested at two different concentrations, i.e . 5 mg/ml and 10 mg/ml for vancomycin and 2 mg/ml and 5 mg/ml for tobramycin . The eluted antibiotic concentrations were determined by the fluorescence polarization immunoassay . Initially large quantities of antibiotics were quickly eluted, depending on the amount of antibiotic mixture . A measurable amount of vancomycin was released for 3 days . There was no difference between the elution kinetics of the two antibiotics from the three different soaked grafts (p>0.05) . Antibiotic-soaked grafts provided zones of inhibition against Staphylococcus aureus on Trypticase soy agar plate for up to 24 h . These results suggest that local application for 24 h of vancomycin or tobramycin with vascular grafts may be effective to prevent graft infection as shown by the fluorescence polarization immunoassay.

Clin Orthop, 1999 Feb, (359), 229 - 36
Oral rifampin plus azithromycin or clarithromycin to treat osteomyelitis in rabbits; Shirtliff ME et al.; A rabbit model for Staphylococcus aureus osteomyelitis was used to compare 28-day combination antibiotic therapy using oral rifampin (40 mg/kg, twice daily) plus oral azithromycin (50 mg/kg, once per day), oral clarithromycin (80 mg/kg, twice daily), or parenteral nafcillin (30 mg/kg, four times daily) . The left tibial metaphysis of New Zealand White rabbits was infected with Staphylococcus aureus . Grades 3 to 4 osteomyelitis (according to the Cierny-Mader classification system) development in the rabbits was confirmed radiographically . After antibiotic therapy regimens of 28 days, all tibias from controls that were infected but left untreated (n = 10) revealed positive cultures for Staphylococcus aureus at a mean concentration of 2.8 x 10(4) colony forming units/g bone . The rifampin plus clarithromycin (n = 15) and rifampin plus azithromycin (n = 15) groups showed significantly lower percentages of positive Staphylococcus aureus infection (20% and 13.3%, respectively) and bacterial concentrations (3.5 x 10(1) and 1.75 x 10(1) colony forming units/g bone, respectively) . The osteomyelitic tibias of the nafcillin plus rifampin treated group (n = 7) showed no detectable Staphylococcus aureus infection (significantly lower than controls) . The differences observed for bone bacterial concentrations and sterilization percentages between the antibiotic treated groups were not statistically significant . Although fluoroquinolones (including ofloxacin and ciprofloxacin) are the agents usually prescribed with rifampin, increasing resistance has been observed . Although macrolides traditionally are not used in the treatment of osteomyelitis, the results of this study indicate that azithromycin and clarithromycin may be attractive partners for rifampin for the treatment of Staphylococcus aureus osteomyelitis in humans.

Clin Orthop, 1999 Feb, (359), 136 - 45
Functional outcome of plate fusions for disorders of the occipitocervical junction; Huckell CB et al.; Twenty-eight patients with average followup of 27 months (range, 12-51 months) required occipitocervical fusion with plates . A 1992 to 1996 consecutive case series enrolled patients prospectively from two institutions . Five surgeons participated . Sixteen patients had inflammatory arthritis; four, osteogenesis imperfecta; three, tumors; three, congenital anomalies; one, pseudarthrosis after odontoid fracture; and one, osteoarthritis . Twenty-two of 28 (78.6%) patients had serious comorbid medical conditions . Additional halo immobilization of 6 weeks was used in 16 of 27 patients . Four patients required revision surgery . No patients showed a decline in neurologic status and average neurologic improvement was one Nurick grade . Two-year followup showed 13 (50%) excellent, nine (34.6%) good, two (7.7%) fair, and two (7.7%) poor outcomes based on a functional outcome scale . There were three deaths during the followup period (overall mortality rate of 10.7%) . One death was attributable to airway obstruction, one death 14 months postoperatively was attributable to late Methicillin resistant Staphylococcus aureus sepsis at the bone graft donor site, and one death 41 months postoperatively was attributable to a stroke . The overall fusion rate was 85.2% (23 of 27 patients), with a 96.3% (26 of 27 patients) occipitocervical fusion rate . Three patients had a possible asymptomatic end segment pseudarthrosis with screw loosening . Twenty-two of 26 (84.6%) interviewed patients would choose the surgery again if given the choice.

Kansenshogaku Zasshi, 1999 Jan, 73(1), 25 - 34
{Studies on detection methods for Legionella species from environmental water}; Kasuga O et al.; We investigated selective cultivation media and previous treatments of samples suitable for detection of Legionella species from environmental water and for elimination of co-existing microbes which gave rise to an interference with the evaluation of Legionella sp . growth . Twenty thousand U of polymyxin B (PL-B)/ml and 100 micrograms of oxytetracycline (OTC)/ml seem to be useful as additives to MWY selective agar medium . Both antibiotics markedly inhibited the growth of co-existing microbes with almost no influence on the growth of Legionella sp . In the studies on the resistance of 8 strains of Legionella sp., 24 strains of co-existing microbes and 2 standard strains of Staphylococcus aureus and Escherichia coli to acid treatment (0.2 M HCl-KCl, pH 2.2, 25 degrees C, 4 minutes) and heating (50 degrees C, 20 minutes), acid treatment or heating alone showed no inhibition on the growth of almost all strains examined . However, combination with acid treatment after heating resulted in an apparent extinction of almost all microbes except for Legionella sp., Seven strains from co-existing microbes showed an apparent growth inhibition against 8 strains of Legionella sp . with different serotypes and were all identified as Pseudomonas aeurginosa, which were all eliminated by means of the combination with acid treatment after heating . From these results, it was concluded that the combined pre-treatment of water samples with acid after heating and the addition of PL-B and OTC into the selective cultivation medium is an useful method for detection of Legionella sp . from environmental water.

FEMS Microbiol Lett, 1999 Feb 15, 171(2), 97 - 102
Identification of three additional femAB-like open reading frames in Staphylococcus aureus; Tschierske M et al.; Three new proteins, FmhA, FmhB and FmhC, with significant identities to FemA and FemB were identified in the Staphylococcus aureus (ATCC 55748) genome database . They were mapped to the SmaI-C, SmaI-H and SmaI-A fragments of the S . aureus 8325 chromosome, respectively . Whereas insertional inactivation of fmhA and fmhC had no effects on growth, antibiotic susceptibility, lysostaphin resistance, or peptidoglycan composition of the strains, fmhB could not be inactivated, strongly suggesting that fmhB may be an essential gene . As deduced from the functions of FemA and FemB which are involved in the synthesis of the peptidoglycan pentaglycine interpeptide, FmhB may be a candidate for the postulated FemX thought to add the first glycine to the nascent interpeptide.

J Shoulder Elbow Surg, 1999 Jan-Feb, 8(1), 1 - 5
Infection after rotator cuff repair; Settecerri JJ et al.; Sixteen patients (15 men and 1 woman) were treated for infection complicating rotator cuff repair during the period 1975 through 1994 . Eight of the 16 patients had their initial procedure performed elsewhere . The remaining 8 procedures were performed at our institution with the known incidence of this complication being 0.27% . In addition to intravenous antibiotic therapy, an average of 3.5 (range 2 to 8) operative procedures were required to eradicate the infections . Micro-organisms cultured were Propionibacter in 6, coagulase negative Staphylococcus in 4, Staphylococcus aureus in 4, Peptostreptococcus magnus in 1, and both Propionibacter and coagulase-negative Staphylococcus in 1 . The deltoid was restored in all patients; the rotator cuff was reparable in 11 . In the 12 shoulders with greater than 1 year of follow-up (average 51 months, range 14 to 165 months), active elevation averaged 110 degrees and external rotation 50 degrees . Four patients had no pain, 4 had minimal pain, and the remaining 4 had moderate pain . Satisfactory final results, which were determined by the patients' opinion or with the use of either the University of California, Los Angeles score or the modified Neer system, were obtained in 5 (42%) of the shoulders.

Eur J Cardiothorac Surg, 1999 Jan, 15(1), 97 - 9
Pseudoaneurysm of the left ventricle after isolated pericarditis and Staphylococcus aureus septicemia; de Boer HD et al.; Left ventricular pseudoaneurysm after isolated pericarditis as a result of Staphylococcal septicemia is very rare . A case of a very young patient is described . Diagnosis is made by echocardiography . Immediate surgical resection of the pseudoaneurysm is the therapy of choice.

Arch Orthop Trauma Surg, 1999, 119(1-2), 82 - 5
Susceptibility to local infection in biological internal fixation . Experimental study of open vs minimally invasive plate osteosynthesis in rabbits; Arens S et al.; Resistance to local infection after fracture fixation with plate osteosynthesis may be influenced by the implantation technique . It is known that the extent of the surgical approach to the bone can compromise the local defence capacity . We have investigated susceptibility to infection after a local bacterial challenge in rabbit tibiae using either the open surgical approach for 'biological' internal fixation of standard 2.0 dynamic compression plates or the method of minimally invasive plate osteosynthesis (MIPO), a percutaneous, tunnelling insertion technique preserving the integrity of the overlying soft tissue . After the wounds had been closed, various concentrations of Staphylococcus aureus were injected in the direct vicinity of the implants . The infection rate for the open surgical technique was 38.5% and that for the MIPO technique, 25% . This difference is not statistically significant (P > 0.05) suggesting that resistance to local infection associated with the MIPO method is at least equivalent to the open approach for plate osteosynthesis.

FEMS Immunol Med Microbiol, 1999 Feb, 23(2), 135 - 46
Possible virulence factors of Staphylococcus aureus in a mouse septic model; Tao M et al.; Twenty clinical isolates of Staphylococcus aureus were examined to elucidate the virulence factors which are directly related to lethality in a mouse septic model . Heat or formalin treatment of the organism abolished the lethal activity of the live organism during challenge intravenously administered via the tail vein . Nevertheless, injection of ten times concentrated culture supernatant fluid (SUP) showed lethal activity in the mouse . However, there was no lethality when SUP was heated at 60 degrees C for 15 min . To examine variations of SUP lethality among strains, we collected 20 strains of S . aureus from four different hospitals . Then, we compared several factors for SUP lethality, which were the extracellular toxins and enzymes, such as toxic shock syndrome toxin 1, enterotoxin A, B, D, and hemolysins (alpha,beta,gamma), and also cytotoxic activity to human polymorphonuclear leukocytes and Vero cells . No difference was found among these factors except cytotoxic activity to Vero cells . Furthermore, we compared two strains in a mouse septic model according to the grade of bacteremia and lethal events . We found that mortality was higher with challenge by the strain whose SUP was lethal in comparison to the strain whose SUP was not lethal, even though the viable bacteria counts in the septic blood in both strains were not significantly different . This strongly supports the possibility that extracellular products, not the cell wall components, of S . aureus play the key role in the lethal event in this mouse septic model . In addition, among the extracellular products, those which have cytotoxic activity to Vero cells may contribute to the lethality in sepsis caused by S . aureus in this murine model.

Biochim Biophys Acta, 1999 Feb 4, 1417(1), 167 - 82
Heparin influence on alpha-staphylotoxin formed channel; Krasilnikov OV et al.; The effects of heparin on ion channels formed by Staphylococcus aureus alpha-toxin (ST channel) in lipid bilayers were studied under voltage clamp conditions . Heparin concentrations as small as 100 pM induced a sharp dose-dependent increase in channel voltage sensitivity . This was only observed when heparin was added to the negative-potential side of lipid bilayers in the presence of divalent cations . Divalent cations differ in their efficiency: Zn2+>Ca2+>Mg2+ . The apparent positive gating charge increased 2-3-fold with heparin addition as well as with acidification of the bathing solution . 'Free' carboxyl groups and carboxyl groups in ion pairs of the protein moiety are hypothesized to interact with sulfated groups of heparin through divalent cation bridges . The cis mouth of the channel (that protrudes beyond the membrane plane on the side of ST addition and to which voltage was applied) is less sensitive to heparin than the trans-mouth . It is suggested that charged residues which interact with heparin at the cis mouth of ST channels and which contribute to the effective gating charge at negative voltage may be physically different from those at the trans mouth and at positive voltage.

Int J Antimicrob Agents, 1999 Jan, 11(1), 47 - 52
Discrepancies between mecA PCR and conventional tests used for detection of methicillin resistant Staphylococcus aureus; Araj GF et al.; Conventional and molecular techniques are being used in the detection of methicillin resistance in Staphylococcus aureus but they do not always show concordant results . In this study, a mecA PCR-based amplification was compared with the 1 microg oxacillin disk diffusion test and the Epsilometer test (E-test) for detection of MICs . Among 31 isolates initially characterized as MRSA by the disk diffusion test, mecA was detected in only 13 (42%) isolates . The E-test showed a wide range of oxacillin MICs (0.5 - > 256 microg/ml) among these 31 MRSA isolates: seven isolates had an MIC of > 256 microg/ml, one had 64 microg/ml, two had 4 microg/ml, two had 3 microg/ml, one had 2.5 microg/ml, nine had 2 microg/ml, three had 1.5 microg/ml, five had 1 microg/ml and one had 0.5 microg/ml . Comparing the mecA PCR results with the E-test oxacillin MIC findings revealed that mecA was detected in seven of eight isolates (87.5%) with an MIC of > or = 64 microg/ml, in three of 14 isolates (21.4%) with an MIC of 2-4 microg/ml and in three of nine isolates (33.3%) with an MIC of < 2 microg/ml . Beta-lactamase production was positive in 28/31 isolates (90.3%) . Because of this variation between tests and since several resistance mechanisms are known to mediate methicillin resistance in S . aureus, the reliable detection of MRSA cannot be solely based on detection of mecA gene in S . aureus . At this stage and until new guidelines are introduced by an official body, such as NCCLS, a combination of conventional methods alone or together with a molecular method should be used every time S . aureus is tested for detection of methicillin resistance.

Int J Antimicrob Agents, 1999 Jan, 11(1), 39 - 46
Improved efficacy with nonsimultaneous administration of netilmicin and minocycline against methicillin-resistant Staphylococcus aureus in in vitro and in vivo models; Goto Y et al.; The effect of combined administration of netilmicin and minocycline against methicillin-resistant Staphylococcus aureus (MRSA) was investigated by using in vitro and in vivo models . Thirty one isolates of MRSA were tested for sensitivity to netilmicin, minocycline, and combination of both by the chequer board method . We used then a dynamic in vitro system, which simulates in vivo serum kinetics, to assess the effect of various combination regimens of these antibiotics against an MRSA isolate with a fractional inhibitory concentration index of 0.25 . The following dose regimens were compared: netilmicin given alone; minocycline given alone; both antibiotics given simultaneously; netilmicin followed by minocycline at 2 h; or minocycline followed by netilmicin at 2 h . Netilmicin showed a stronger activity than minocycline . On the other hand, their combination was synergistic against 19% of isolates and additive against 77% of isolates . Against one isolate only, it was indifferent, and no antagonism was observed . In the auto-simulation system, the combination of antibiotics was generally more effective than single drugs, with the regimen netilmicin followed by minocycline at 2 h showing the highest antibacterial effect . In the mouse model of pulmonary infection, the bacterial counts and histopathological findings of the lungs improved by treatment with this regimen . This regimen led also to a significantly high survival rate of mice with systemic infection compared to the other treatment regimens . Therefore, it was concluded that administration of netilmicin followed by minocycline at 2 h may be an effective combination against MRSA infection.

Arch Intern Med, 1999 Mar 8, 159(5), 473 - 5
Infective endocarditis due to Staphylococcus aureus: deleterious effect of anticoagulant therapy; Tornos P et al.; BACKGROUND: The use of anticoagulant therapy in patients with infective endocarditis (IE) is a controversial issue . OBJECTIVE: To study the impact of anticoagulant therapy on the clinical outcome, mortality, and cause of death in a series of patients with native and prosthetic left-sided Staphylococcus aureus IE . METHODS: This report is based on all consecutive cases of IE diagnosed at our hospital between 1975 to 1997 . Clinical data, including the use of anticoagulant therapy at the time of diagnosis, were prospectively obtained, and antibiotic treatment and surgical indications were uniform throughout the study period . Computed tomographic scans of all clinical records were reviewed . RESULTS: Of 637 consecutive patients with IE, 56 had left-sided S aureus IE affecting native valves in 35 patients and prosthetic valves in 21 patients . Of the patients with prosthetic valve IE, 19 (90%) were taking oral anticoagulant therapy at the time of diagnosis while no patient with native valve IE was receiving such treatment . There were no differences between native valve IE and prosthetic valve IE in age, sex, embolic episodes, and number of central nervous system complications . Mortality was higher in prosthetic valve IE than in native valve IE (71% vs 37%; P=.02) . No patient with native valve IE died due to central nervous system complications, while 73% (11 of 15 patients) with prosthetic valve IE died due to central nervous system complications . The difference in the distribution of the type of death (stroke vs other) was significant (P<.007) . CONCLUSIONS: Our results suggest that in left-sided S aureus IE anticoagulant therapy is closely associated with death due to neurologic damage . According to our data, as soon as the clinical diagnosis of S aureus IE is indicated the use of anticoagulant therapy should be immediately stopped until the septic phase of the disease is overcome.

Arch Intern Med, 1999 Mar 8, 159(5), 462 - 9
Clinical features of Staphylococcus aureus endocarditis: a 10-year experience in Denmark; Roder BL et al.; BACKGROUND: Both morbidity and mortality resulting from Staphylococcus aureus endocarditis are known to be high, and the incidence of this disease seems to increase . The Statens Serum Institut, Copenhagen, Denmark, made it possible for us to analyze the clinical features of S aureus endocarditis in a nation-wide population of non-drug addicts . METHODS: Almost all Danish cases of bacteremia due to S aureus are reported to the Staphylococcus laboratory, Statens Serum Institut . The medical records were reviewed in cases reported from 1982 to 1991 in which the diagnosis of endocarditis was reported or suspected . RESULTS: A total of 260 patients, 145 males and 115 females, fulfilled the diagnostic criteria . The median age was 67.5 years . In 83 patients, the diagnosis of endocarditis was not suspected clinically . The overall mortality rate among those patients whose disease was diagnosed clinically was 46% . Among the subset of patients who received medical therapy only and appropriate antistaphylococcal treatment, mortality was significantly associated with late congestive heart failure, age, and involvement of the central nervous system . CONCLUSIONS: A raised awareness of the paucity of clinical findings and a more frequent use of echocardiography as a screening method seem essential to improve the prognosis of patients with S aureus endocarditis . Involvement of the central nervous system constitutes a relative indication of early valve replacement.

J Clin Invest, 1999 Mar, 103(5), 715 - 21
Cell-wall determinants of the bactericidal action of group IIA phospholipase A2 against Gram-positive bacteria; Foreman-Wykert AK et al.; We have shown previously that a group IIA phospholipase A2 (PLA2) is responsible for the potent bactericidal activity of inflammatory fluids against many Gram-positive bacteria . To exert its antibacterial activity, this PLA2 must first bind and traverse the bacterial cell wall to produce the extensive degradation of membrane phospholipids (PL) required for bacterial killing . In this study, we have examined the properties of the cell-wall that may determine the potency of group IIA PLA2 action . Inhibition of bacterial growth by nutrient deprivation or a bacteriostatic antibiotic reversibly increased bacterial resistance to PLA2-triggered PL degradation and killing . Conversely, pretreatment of Staphylococcus aureus or Enterococcus faecium with subinhibitory doses of beta-lactam antibiotics increased the rate and extent of PL degradation and/or bacterial killing after addition of PLA2 . Isogenic wild-type (lyt+) and autolysis-deficient (lyt-) strains of S . aureus were equally sensitive to the phospholipolytic action of PLA2, but killing and lysis was much greater in the lyt+ strain . Thus, changes in cell-wall cross-linking and/or autolytic activity can modulate PLA2 action either by affecting enzyme access to membrane PL or by the coupling of massive PL degradation to autolysin-dependent killing and bacterial lysis or both . Taken together, these findings suggest that the bacterial envelope sites engaged in cell growth may represent preferential sites for the action and cytotoxic consequences of group IIA PLA2 attack against Gram-positive bacteria.

Arch Pharm Res, 1999 Feb, 22(1), 25 - 9
Psammaplin A, a natural bromotyrosine derivative from a sponge, possesses the antibacterial activity against methicillin-resistant Staphylococcus aureus and the DNA gyrase-inhibitory activity; Kim D et al.; Psammaplin A, a natural bromotyrosine derivative from an associated form of two sponges (Poecillastra sp . and Jaspis sp.) was found to possess the antimicrobial effect on the Gram-positive bacteria, especially on methicillin-resistant Staphylococcus aureus (MRSA) . The minimal inhibitory concentration of psammaplin A against twenty one MRSAs ranged from 0.781 to 6.25 microg/ml, while that of ciprofloxacin was 0.391-3.125 microg/ml . Psammaplin A could not bind to penicillin binding protein, but inhibited the DNA synthesis and the DNA gyrase activity with the respective 50% (DNA synthesis) and 100% (DNA gyrase) inhibitory concentration 2.83 and 100 microg/ml . These results indicate that psammaplin A has a considerable antibacterial activity, although restricted to a somewhat narrow range of bacteria, probably by inhibiting DNA gyrase.

Vet Rec, 1999 Jan 16, 144(3), 60 - 4
Methicillin-resistant Staphylococcus aureus infections in 11 dogs; Tomlin J et al.; Methicillin-resistant Staphylococcus aureus infection was identified in 11 dogs . The infection was associated with surgical treatment especially orthopaedic surgery . Infection after traumatic wounding, and recurrent pyoderma was also seen . Oral antibiotic treatment improved or resolved the infection in nine of the 11 dogs, although the methicillin-resistant isolates were susceptible to relatively few antibiotics.

J Infect Dis, 1999 Apr, 179(4), 883 - 91
Transmission dynamics of epidemic methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci in England and Wales; Austin DJ et al.; A simple epidemiological framework for the analysis of the transmission dynamics of hospital outbreaks of epidemic methicillin-resistant Staphylococcus aureus (EMRSA) and vancomycin-resistant enterococci (VRE) in hospitals in England and Wales is presented . Epidemic strains EMRSA-15 and EMRSA-16 are becoming endemic in hospitals in the United Kingdom, and theory predicts that EMRSA-15 and EMRSA-16 will reach respective endemic levels of 158 (95% confidence interval {CI}, 143-173) and 116 (95% CI, 109-123) affected hospitals with stochastic fluctuations of up to 30 hospitals in each case . An epidemic of VRE is still at an early stage, and the incidence of hospitals newly affected by VRE is growing exponentially at a rate r=0.51/year (95% CI, 0.48-0.54) . The likely impact of introducing surveillance policies if action is taken sufficiently early is estimated . Finally, the role of heterogeneity in hospital size is considered: "Super-spreader hospitals" may increase transmission by 40%-132% above the expected mean.

Folia Microbiol (Praha), 1998, 43(6), 617 - 22
Substrate-dependent cadmium toxicity affecting energy-linked K+/86Rb transport in Staphylococcus aureus; Tynecka Z et al.; Bacteria accumulate high amounts of potassium in the cytoplasm . For studying transport of K+ (with 86Rb as a marker) in bacteria (Staphylococcus aureus 17810S), the cells were depleted of the internal K+ pool by a DNP treatment . Kinetics and energetics of 86Rb transport was assayed with glucose as an exogenous energy source . It was shown that 86Rb uptake proceeded via a low affinity K+ transport system with an apparent K(m) of 2.3 mmol/L Rb+ . Studies with the lipophilic cation TPP+ (tetraphenylphosphonium), the protonophore CCCP (carbonyl cyanide 3-chlorophenylhydrazone) and inhibitors (HQNO--2-heptyl-4-hydroxyquinoline N-oxide; iodoacetate) indicated that 86Rb transport was driven by delta psi (membrane potential) generated via the respiratory chain . The effect of Cd2+ on 86Rb transport was assayed with two energy donors--glucose and L-lactate . It was found that Cd2+ strongly inhibited delta psi-dependent 86Rb transport energized by cadmium-sensitive glucose oxidation, but was not toxic when cadmium-insensitive L-lactate was used as an energy source . The mechanism of these differential, substrate-dependent effects of Cd2+ on 86Rb transport is discussed.

J Hepatol, 1999 Feb, 30(2), 249 - 53
Staphylococcus aureus nasal carriage in 104 cirrhotic and control patients . A prospective study; Chapoutot C et al.; BACKGROUND/AIMS: Bacterial infections, specially Staphylococcus aureus (S . aureus) septicemia, remain a leading cause of death following liver transplantation . It has been demonstrated that nasal carriage of S . aureus is associated with invasive infections in patients undergoing hemodialysis and could be decreased by use of antibiotic nasal ointment . However, in cirrhotic patients, the frequency of nasal carriage is unknown . The aims of this study were to determine the prevalence of S . aureus nasal carriage in cirrhotic patients and to assess nosocomial contamination . METHODS: One hundred and four patients were included in a prospective study, 52 cirrhotic and 52 control (hospitalized patients without cirrhosis or disease which might increase the rate of nasal carriage of S . aureus) . On admission and after a few days of hospitalization, nasal specimens from each anterior naris were obtained for culture . S . aureus was identified by the gram strain, positive catalase and coagulase reactions; antibiotic susceptibility was determined using a disk-diffusion test . RESULTS: Both groups were similar with regard to age and sex . The prevalence of nasal colonization on hospital admission was 56% in cirrhotic patients and 13% in control patients (p = 0.001) . After an average of 4 days, 42% of cirrhotics and 8% of control patients were colonized (p = 0.001), without any nosocomial contamination . Three strains out of 29 were oxacillin-resistant in cirrhotic patients, and none in controls (p>0.05) . There was no statistical difference in carriage rate according to sex, age, cause of cirrhosis and Child-Pugh score . Previous hospitalization (OR, 6.3; 95% CI, 2.3 to 19.9; p = 0.0006) and cirrhosis (OR, 4.4; 95% CI, 1.5 to 13.4; p = 0.0048) were independent predictors of colonization . CONCLUSION: Cirrhotic patients had a higher S . aureus nasal carriage rate than control subjects . Previous hospitalization and cirrhosis diagnosis were correlated to nasal colonization . Further studies are necessary to determine if nasal decontamination could reduce S . aureus infections after liver transplantation.

Wien Klin Wochenschr, 1999 Jan 15, 111(1), 26 - 32
{Hypoplastic left-heart syndrome . Initial intensive care experiences with the Norwood operation in Vienna}; Golej J et al.; Palliative surgery of the hypoplastic left heart syndrome (HLHS), whereby both pulmonary and systemic circulation are restored, was first described by Norwood in 1983 . Careful ventilatory and pharmacologic modulation of the ratio of pulmonary to systemic vascular resistance are a crucial part of pre-, peri- and postoperative management . We report our experience in 3 of 7 newborns with HLHS who underwent the Norwood operation . Hemodynamic and respiratory parameters were evaluated retrospectively in these patients and we analysed the influence of diagnostic and therapeutic interventions on the course of disease before and after operation . During prostaglandin therapy two of three patients required mechanical ventilation preoperatively because of pulmonary hyperperfusion . Decreased myocardial contractility, oliguria and increased pulmonary vascular resistance characterized the postoperative course . The management included a careful application of inotropic support when necessary, adaptation of the ventilatory setting in order to modulate pulmonary perfusion and, in addition, institution of peritoneal dialysis . One patient died from staphylococcus aureus and superinfection with respiratory syncytial virus on day 41 after the operation . Maintaining an optimal balance between pulmonary and systemic blood flow is an essential aspect of postoperative management . Serum lactate and central venous oxygen saturation are helpful parameters in monitoring therapeutic measures in these patients . We conclude from our preliminary experience, that the Norwood operation might be an alternative therapeutic approach for newborns with HLHS in whom heart transplantation is not possible.

Eur J Dermatol, 1999 Mar, 9(2), 129 - 31
Hyperimmunoglobin E syndrome: a sign of TH1/TH2 imbalance?
Shirafuji Y, Matsuura H, Sato A, Kanzaki H, Katayama H, Arata J.
We report on a patient with hyperimmunoglobulin E syndrome, who developed pruritic vesiculopapules from the age of six months and also had recurrent episodes of skin abscesses and oral thrush . Serum IgE was extremely elevated at 59,514 IU/ml and specific IgE antibody to Staphylococcus aureus was positive . Histological examination from a vesiculopapule on the face revealed that eosinophil-rich infiltration involved hair follicles, similar to eosinophilic pustular folliculitis . We also examined cytokine profiles of circulating CD4+ T cells by intracellular cytokine staining and flow cytometry . The ratio of cells positive for interferon-gamma was significantly reduced compared with a control . Several reports have shown decreased interferon-gamma production by peripheral blood mononuclear cells of patients with hyperimmunoglobulin E syndrome . We think that this cytokine profile and the histological findings of our patient support the hypothesis that TH1/TH2 imbalance is involved in hyperimmunoglobulin E syndrome.

Curr Pharm Des, 1999 Feb, 5(2), 45 - 55
Methicillin-resistance in Staphylococcus aureus - molecular basis, novel targets and antibiotic therapy; Ehlert K; Methicillin-resistant S . aureus are the major cause of nosocomial bacteremias showing a high morbidity rate in intensive care units . These strains are often resistant against almost all antibiotics in clinical use with the exception of vancomycin . However, the first isolation of a S . aureus strain with a diminished susceptibility to vancomycin from a hospitalized patient in Japan has been reported very recently . Therefore, current antibiotic therapy is difficult and expensive, often a combination of several antibiotics has to be used . For this reason novel antibiotics to combat staphylococcal bacteremias, which prevent further spread of resistance are urgently needed . One approach might be the investigation of the mechanism of methicillin resistance, which is mediated by PBP2a, an additional penicillin-binding protein present in resistant strains with low affinity to ss-lactams . Beside PBP2a other housekeeping genes, the so called fem factors, are involved in expression of methicillin resistance . Two of these fem factors, the FemAB proteins, have been shown to participate in the formation of the pentaglycine crossbridge, which is a unique staphylococcal cell wall component . The biosynthesis of the pentaglycine side chains is not fully elucidated, but follows an interesting novel mechanism with unusual glycyl-tRNA as a substrate . Furthermore, inactivation of femAB, which have been reported as essential for bacterial growth, causes a completely restoration of antibiotic susceptibility in MRSA strains . Thus, these proteins might serve as attractive novel anti-staphylococcal targets for a small-range antibiotic.

J Biol Chem, 1999 Mar 12, 274(11), 6911 - 9
Characterization of the interaction between the herpes simplex virus type I Fc receptor and immunoglobulin G; Chapman TL et al.; Herpes simplex virus type I (HSV-1) virions and HSV-1-infected cells bind to human immunoglobulin G (hIgG) via its Fc region . A complex of two surface glycoproteins encoded by HSV-1, gE and gI, is responsible for Fc binding . We have co-expressed soluble truncated forms of gE and gI in Chinese hamster ovary cells . Soluble gE-gI complexes can be purified from transfected cell supernatants using a purification scheme that is based upon the Fc receptor function of gE-gI . Using gel filtration and analytical ultracentrifugation, we determined that soluble gE-gI is a heterodimer composed of one molecule of gE and one molecule of gI and that gE-gI heterodimers bind hIgG with a 1:1 stoichiometry . Biosensor-based studies of the binding of wild type or mutant IgG proteins to soluble gE-gI indicate that histidine 435 at the CH2-CH3 domain interface of IgG is a critical residue for IgG binding to gE-gI . We observe many similarities between the characteristics of IgG binding by gE-gI and by rheumatoid factors and bacterial Fc receptors such as Staphylococcus aureus protein A . These observations support a model for the origin of some rheumatoid factors, in which they represent anti-idiotypic antibodies directed against antibodies to bacterial and viral Fc receptors.

Biochem Biophys Res Commun, 1999 Mar 5, 256(1), 142 - 6
S . aureus superantigen protein A expands CD4(+)/CD8(+)/CD19(+)/CD34(+) cells in mice: a potential immunorestorer; Ghosh AK et al.; Protein A (PA) of Staphylococcus aureus is known for its immunostimulatory, anti-cancer, and anti-toxic properties . The present study revealed that PA stimulates specific immunocytes to act as a potential immunorestorer . It has also been shown that the percentage of various cell types bearing different clusters of differentiation markers, e.g., CD4(+), CD8(+), CD19(+), increases considerably after inoculation with PA . It has also been observed that CD34(+) progenitor cells of bone marrow also increased significantly (P < 0.05) upon PA treatment . PA significantly elevated Th-1 cytokines, e.g., IFN-gamma, TNF-alpha, and IL-1alpha . The increased percentages of CD4(+), CD8(+), CD19(+), CD34(+) cells and elevated cytokine levels in PA treated animals may contribute to the reported anti-tumor, anti-fungal, anti-parasitic, and anti-toxic properties of PA . Since in various diseased conditions and during toxic drug therapy lymphocytes bearing such differentiation markers get suppressed, this type of approach could help in immunorestoration of the host . These findings might help in designing therapeutic approaches toward various diseases which cause immunosuppression .

Biochem Biophys Res Commun, 1999 Mar 5, 256(1), 6 - 12
Molecular modeling and experimental approaches toward designing a minimalist protein having Fc-binding activity of Staphylococcal protein A; Sengupta J et al.; Protein A (PA), a cell wall constituent of Staphylococcus aureus, has got the unique property of binding with the Fc fragment of IgG from various species . The sequence data indicate five highly homologous Fc-binding regions in protein A . Computer sequence analysis provided the tryptic and chymotryptic fragments of IgG-binding domains of protein A . Molecular modeling in conjunction with molecular mechanical calculation has been used to search for the smallest possible proteolytic fragments of PA, still retaining Fc-binding activity . A 20-residue peptide (typtic fragment) and a 16-residue peptide (chymotryptic fragment) have been indicated, by molecular modeling studies, to possess IgG-binding affinity comparable to that of the B domain of Protein A . Binding of a 20-residue peptide has been substantiated experimentally by immunoprecipitation, capillary electrophoresis, and circular dichroism spectroscopic analyses .

Spinal Cord, 1999 Feb, 37(2), 103 - 9
Extradural infections of the spine; Klekamp J et al.; OBJECTIVES: We have observed a recent increase in the incidence of spinal extradural infections . To determine postoperative outcome and prognosis we have undertaken a retrospective study on patients with spinal extradural abscesses between 1978 and 1996 treated in the Department of Neurosurgery at the Nordstadt Hospital in Hannover, Germany . METHODS: Case records, outpatient files, operation notes, neuroradiological examinations and pathological reports were analysed . Neurological function was documented using a score system for each symptom . RESULTS: Twenty-two patients underwent 24 operations during the study period . Staphylococcus aureus was the organism most commonly isolated . Patients presented after a mean history of 1.8+/-2.6 months with acute development of severe para- or tetraparesis and were followed up for an average period of 6+/-7 months . Two groups were distinguished . One group was characterized by epidural collections of pus (14 patients) . Two patients in this group were not operated due to their moribund state and died from uncontrollable septicemia . Two of the remaining 12 operated patients died within 30 days after surgery due to generalized septicemia or other medical problems unrelated to the spinal involvement . Of the ten surviving patients, five sustained major neurological deficits, whereas the remaining five patients made an incomplete recovery . The second group consisted of eight patients in a significantly better pre-operative health condition in whom granulomatous material was obtained during the operation and the outcome was considerably better . No patient in this group died . Six patients recovered with no or mild neurological deficits . CONCLUSION: Spinal extradural infections require immediate surgical intervention . Neurological outcome depends on the pre-operative neurological status . Survival is determined by the general health condition of the patient.

Immunol Lett, 1999 Feb, 65(3), 175 - 81
Therapeutic and prophylactic uses of protein A in the control of Leishmania donovani infection in experimental animals; Ghose AC et al.; The role of the immunomodulator Protein A (PA) (from Staphylococcus aureus, Cowan I strain) in the control of leishmanial infection was studied in experimental animals . Treatment of Leishmania donovani infected hamsters with PA led to a moderate level of reduction of parasite load in their spleen (68%) and liver (46%) . However, combination therapy of PA with the antileishmanial drug stibanate induced a more marked reduction of the spleen (88%) and liver (85%) parasitemia compared to that induced by PA or drug treatment alone . Similar results were also obtained with L . donovani infected BALB/c mice as the combination therapy of PA and stibanate led to a significant reduction (84%) of liver parasite load in comparison to that induced by PA (38%) or drug (61%) treatment alone . Apart from its therapeutic use, PA could also be used as a prophylactic agent in the control of leishmanial infection . Thus, treatment of hamsters with PA before leishmanial challenge significantly reduced their organ parasite load (by 59-78%) compared to that observed in infected controls without prior PA treatment . The antileishmanial effect of PA was likely to be mediated through the activation of macrophages leading to an enhancement of their phagocytic as well as leishmaniacidal activities . Subsequent studies demonstrated that PA treatment led to an increased production of nitric oxide by macrophages which could primarily be responsible for their enhanced parasite killing ability.

Int J Oral Maxillofac Surg, 1999 Feb, 28(1), 60 - 1
Toxic shock syndrome secondary to a dental abscess; Fardy CH et al.; A 9-year-old girl presented with arthralgia and myalgia which progressed to developing renal failure and overwhelming septic shock . The underlying cause was assumed to be a periodontal abscess from an upper right deciduous canine tooth . The pus from the abscess grew a toxic shock syndrome toxin 1-producing Staphylococcus aureus . This case illustrates the importance of an oral surgical review of patients presenting with features of toxic shock syndrome if the source of the infection is not immediately obvious.

Infect Control Hosp Epidemiol, 1999 Feb, 20(2), 133 - 5
The continuing evolution of methicillin-resistant Staphylococcus aureus in Western Australia; Torvaldsen S et al.; Methicillin-resistant Staphylococcus aureus (MRSA) has been notifiable in Western Australia since 1985 . This article reviews the notification data from 1994 to 1997, focusing on increases in MRSA notifications and the proportion that are local strains; changes in the geographical distribution of MRSA; and changes in antibiotic-resistance patterns.

Nippon Geka Gakkai Zasshi, 1998 Dec, 99(12), 831 - 6
{Indications for and limitations of minimally invasive cardiac surgery with the lower ministernotomy approach}; Kobayashi J et al.; The chief benefits of small skin incisions are reduced patient discomfort, accelerated recovery, and cosmetic satisfaction without compromising the quality of surgery . Since April 1997, the lower ministernotomy approach without femoral cannulation has been performed in 43 patients in the authors' institutions . The indications for this approach were initial single valve surgery and secundum-type atrial septal defect . Cases of aortic valve regurgitation that could be repaired, and aortic stenosis that necessitated annular enlargement were excluded . Among patients with mitral valve disease, those with chronic atrial fibrillation were excluded frpm undergoing the Maze procedure and those reguiring chordal reconstruction for anterior leaflet were also excluded . Mitral valve repair for mitral regurgitation was performed in 8 patients, and open mitral commissurotomy in 2 . Mitral valve replacement was performed in 3 patients and aortic valve replacement in 13 . Closure of an atrial septal defect was carried out in 18 cases . An approximately 10-cm median skin incision was made, and a ministernotomy with a lower semitransverse division (inverted L-shape) was carried out . Cardiopulmonary bypass was initiated with ascending aortic cannulation and right-angled venous cannulae in the superior and inferior vena cava for mitral valve disease . Single venous cannulae from the right atrial appendage was used for aortic valve disease . Surgery was performed with mild hypothermia and intermittent tepid blood cardioplegia with diltiazem . A rigid 30-degree angle scope held by a videoscope holder with a flexible arm was used for mitral valve surgery . There were one hospital death due to perioperative myocardial infarction and pulmonary embolism . There was one reopening for bleeding which resulted in methicillin-resistant Staphylococcus aureus mediastinitis . However, the patients was discharged after rectal muscle flap repair . There was one reoperation for mitral valve repair due to hemolysis . The improvement of surgical instruments and materials will further facilitate this procedurePublication Types:

Clinical Trial

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