Staphylococcus aureus

J Antimicrob Chemother, 1996 Nov, 38(5), 859 - 63
Effect of paclitaxel alone or in combination on the intracellular penetration and activity of quinolones in human neutrophils; Garcia I et al.; We evaluated the effect of paclitaxel alone or in combination with cisplatin or doxorubicin, on the intracellular penetration and activity of ciprofloxacin, ofloxacin, levofloxacin and sparfloxacin in human polymorphonuclear leukocytes (PMN) . In general, paclitaxel either alone or in combination did not affect the intracellular concentrations of the quinolones evaluated (intracellular to extracellular concentration ratio (C/E > 4) . However, at high concentrations (20 mg/L) paclitaxel decreased the penetration of ofloxacin and levofloxacin although the C/E ratios remained higher than 3 . Paclitaxel alone or in combination affected neither the production of oxygen radicals by PMN nor the intracellular activity of the quinolones against Staphylococcus aureus.

J Am Soc Nephrol, 1996 Nov, 7(11), 2403 - 8
Nasal mupirocin prevents Staphylococcus aureus exit-site infection during peritoneal dialysis . Mupirocin Study Group; Plasma concentrations of endotoxin and antiendotoxin antibodies in patients with multiple injuries: a prospective clinical study; Department of Surgery, University of Ulm, GermanyOBJECTIVE: To investigate the time course of endotoxaemia and its effects on the synthesis of antiendotoxin antibodies in patients with multiple injuries . DESIGN: Prospective clinical study . SETTING: University hospital, Germany . PATIENTS: 40 Patients with multiple injuries and 20 healthy volunteers who served as controls . INTERVENTIONS: Blood samples were collected up to 10 days after injury and the concentrations of endotoxin, antiendotoxin antibodies to four endotoxins, and for anti-alpha-haemolysin of Staphylococcus aureus were measured . The kinetics of endotoxaemia and antiendotoxin antibodies were investigated . RESULTS: Endotoxaemia peaked 0-3 hours after injury at 0.425 EU/ml and decreased thereafter to 0.04 EU/ml within five days . Total concentrations of IgM, IgA, and IgG increased continuously after day 3 (p < 0.05), but the specific IgM response to all endotoxins was only temporary and the relative content of specific antibodies to all endotoxins peaked at day 3 (p < 0.05) . Antiendotoxin antibodies of IgM class cross-reacted among themselves . There was no general increase in specific antiendotoxin antibodies of IgA and IgG class . The relative content of specific antibodies to alpha-haemolysin of S aureus of all classes of immunoglobulins (IgM, IgA, IgG) remained on the same level from day 0-10 . CONCLUSION: Multiple injuries are associated with early and temporary endotoxaemia which causes specific increases in antiendotoxin antibodies of the IgM-class . IgM antibodies to endotoxins cross-react among themselves.

Proc Assoc Am Physicians, 1996 Nov, 108(6), 455 - 66
Interaction of tumor necrosis factor-alpha and granulocyte colony-stimulating factor on neutrophil apoptosis, receptor expression, and bactericidal function; Sullivan GW et al.; Infected patients are likely to have increased levels of tumor necrosis factor-alpha (TNF-alpha) and may be treated with recombinant human granulocyte colony-stimulating factor (G-CSF) . Recombinant human TNF-alpha activates polymorphonuclear neutrophil (PMN) inflammatory activity . We examined the effect of exposure to TNF-alpha and G-CSF alone and in combination on PMN apoptosis, receptor expression, phagocytosis, and bactericidal function . The results were compared to those obtained with a promoter of PMN apoptosis, cycloheximide . After 24 hr, 27% of PMNs were nonapoptotic, and TNF-alpha (1 unit/ml) showed no change . Cycloheximide (10 micrograms/ml) decreased the number of nonapoptotic cells to 10% of the initial PMN . In contrast, G-CSF (30 ng/ml) decreased apoptosis (57% nonapoptotic PMN after 24 hr) . Both G-CSF and TNF-alpha (but not cycloheximide) induced preservation of PMN Fc gamma RIII (467% and 167% of 24-hr controls, respectively) and beta 2-integrin expression (150% and 168% of 24-hr controls, respectively) . G-CSF (but not TNF-alpha or cycloheximide) stimulated expression of Fc gamma RI (191% of 24-hr control) and Fc gamma RII (267% of 24-hr control) . G-CSF (but not TNF-alpha) maintained the ability of PMN to ingest and kill opsonized Staphylococcus aureus . TNF-alpha decreased the effect of G-CSF on apoptosis, expression of Fc gamma RIII and Fc gamma RI, and bactericidal function . Thus, TNF-alpha promoted expression of Fc gamma RIII and beta 2-integrin receptors, which are important for phagocytic activity, and G-CSF diminished apoptosis, increased Fc gamma receptor expression, and maintained bactericidal function . TNF-alpha counteracted some effects of G-CSF . Interactions of these cytokines in vivo serve to regulate the PMN inflammatory response and bactericidal capacity.

Arzneimittelforschung, 1996 Nov, 46(11), 1045 - 53
Stereo-selective calcium antagonistic and binding properties of the enantiomers of lemildipine in vascular tissue of pigs and dogs; Nakayama K et al.; Stereo-selective calcium antagonistic properties of the enantiomers of lemildipine (CAS 94739-29-4, NB-818) were assessed in vascular tissues, including pig coronary artery and dog cerebral artery . Ca2+ antagonistic action of (-)-lemildipine was about 5 times and 100 times more potent than nifedipine and (+)-lemildipine, respectively . (-), (+), and (+/-)-lemildipine showed a slow onset and long duration of Ca2+ antagonistic action . Pretreatment with (-)-lemildipine and (+/-)-lemildipine for 30 min inhibited the contractions produced by 5-hydroxytryptamine and endothelin-1 with pD2 values between 6.0-8.5, whereas (+)-lemildipine and nifedipine were less potent . Of the lemildipine enantiomers, (+)-lemildipine at a low concentration (1 nmol/l) had a slight but significant Ca2+ agonistic action . However, (+)-lemildipine had no apparent effect on the pCa-tension relationship in the dog basilar artery permeabilized with Staphylococcus aureus alpha-toxin . Enantiomers of lemildipine as well as nifedipine competitively antagonized the specific binding of (+)-{3H}PN 200-110 (isradipine) to the membranes of pig coronary artery in the following order: (-)-lemildipine > nifedipine > (+/-)-lemildipine > (+)-lemildipine . These results suggest that the stereo-selective Ca2+ antagonistic actions of lemildipine enantiomers and nifedipine assessed in the functional experiments were well correlated with their potencies for the competition with the (+)-{3H}PN 200-110 binding to the pig coronary artery.

FEMS Immunol Med Microbiol, 1996 Nov, 16(1), 51 - 9
Developmental and environmental factors that enhance binding of Bordetella pertussis to human epithelial cells in relation to sudden infant death syndrome (SIDS); Saadi AT et al.; Asymptomatic infection due to Bordetella pertussis has been suggested to be one cause of sudden infant death syndrome (SIDS) . We examined developmental and environmental factors previously found to affect binding of another toxigenic species, Staphylococcus aureus, to human epithelial cells: expression of the Lewis(a) antigen; infection with respiratory syncytial virus (RSV); exposure to cigarette smoke; and the inhibitory effect of breast milk on bacterial binding . Binding of two strains of B . pertussis (8002 and 250825) to buccal epithelial cells was significantly reduced by treating the cells with monoclonal antibodies to Lewis(a) (P < 0.05) and Lewis(x) (P < 0.01) antigens . Both strains bound in significantly greater numbers to cells from smokers compared with cells from non-smokers (P < 0.05) . HEp-2 cells infected with RSV subtypes A or B had higher binding indices for both 8002 (P < 0.001) and 250825 (P < 0.01) . On RSV-infected cells, there was significantly enhanced binding of monoclonal antibodies to Lewis(x) (P < 0.05), CD14 (P < 0.001) and CD18 (P < 0.01); and pre-treatment of cells with anti-CD14 or CD18 also significantly reduced binding of both strains of B . pertussis . Pre-treatment of the bacteria with human milk significantly reduced their binding to epithelial cells . The results are discussed in relation to our three-year survey of bacterial carriage among 253 healthy infants, their mothers and local SIDS cases between 1993-1995 and in relation to the change to an earlier immunisation schedule for infants and the recent decline in SIDS in Britain.

Rinsho Byori, 1996 Nov, 44(11), 1093 - 9
{Mini review: a factor enhanced the antibacterial effect of beta-lactams on methicillin-resistant Staphylococcus aureus}; Tajima Y; We found a factor (Factor T) in aged mixtures of tungstate and phosphate which greatly enhances the antibacterial effects of beta-lactams on methicillin-resistant Staphylococcus aureus (MRSA), while Factor T alone did not strongly inhibit bacterial growth . The effect on methicillin-susceptible S.aureus was weak . There was no synergism of Factor T with other classes of antibiotics, nor with other groups of bacteria . Factor T is probably a complex of phosphate and tungstate, and reduced the expression of penicillin-binding protein-2', thus sensitizing the MRSA strains to beta-lactams.

Biochem Mol Biol Int, 1996 Nov, 40(4), 779 - 85
Purification and enzymatic peptide mapping of protein synthesis elongation factor-2 from mink and chicken livers; Riis B; This investigation has shown it it possible to purify elongation factor-2 from livers of two rather distinct animal species, minks and chicken, to high homogeneity by employing the same purification procedure . It is also shown that making peptide maps of the factor by the use of Staphylococcus aureus Endoprotease Glu-C gives the same pattern . Combined, these two experimental approaches show that the evolution has conserved this elongation factor in two species with a rather different physiology and choice of feeding substances . It is also shown that using mink or chicken livers as staring material for purification of eEF-2 is both technically and economically sound when obtaining large amounts of highly purified eEF-2 is the ultimate goal.

Eur J Biochem, 1996 Nov 1, 241(3), 765 - 71
Phosphorylation and dephosphorylation in the proline-rich C-terminal domain of microtubule-associated protein 2; Sanchez C et al.; The C-terminal domain of microtubule-associated protein 2 (MAP2) contains a proline-rich region and the tubulin-binding domain . We have generated antibodies to follow the phosphorylation state of the proline-rich domain . One of these antibodies (no . 305) has been raised against a synthetic peptide P (sequence RTPGTPGTPSY) phosphorylated at the threonine residues . This sequence is present in the proline-rich region of MAP2 and is phosphorylated in vitro by at least three different proline-directed protein kinases: p42mpk, p34cdc2, and GSK3 (glycogen-synthase kinase 3) alpha/beta . The MAP2 sites phosphorylated by these kinases are different, although all of them phosphorylate the C-terminal domain of MAP2 as determined by Staphylococcus aureus V8 protease mapping . Nonphosphorylated peptide P can be phosphorylated in vitro by all three kinases studied with similar efficiency . In high-molecular-mass MAP2, this sequence is highly phosphorylated in vivo at the late stages of rat development . This motif can be rapidly dephosphorylated in vitro by protein-phosphatase 1 (PP1) and 2A (PP2A) catalytic subunits but not by PP2B.

Res Vet Sci, 1996 Nov, 61(3), 231 - 3
Influence of age of the donor sheep on the phagocytosis of Staphylococcus aureus subspecies anaerobius and S aureus by neutrophils; Quiteria JA et al.; The age of the sheep donating neutrophils had a marked influence in vitro on their phagocytic ability with respect to Staphylococcus aureus and S aureus subspecies anaerobius . Neutrophils from lambs five to eight weeks old phagocytosed these organisms significantly less efficiently (P < 0.001) than neutrophils from adults two to four years old . However, neutrophils from the young animals phagocytosed S aureus significantly (P < 0.001) better than S aureus subspecies anaerobius (61.5 v 53.8 per cent), whereas there was no significant difference in the ability of the neutrophils from adult sheep to phagocytose S aureus and S aureus subspecies anaerobius (68.2 v 68.2 per cent).

Protein Expr Purif, 1996 Nov, 8(3), 332 - 40
A Trypanosoma cruzi polyantigen obtained by gene fusion: its expression in Staphylococcus aureus and rapid purification; Moreno JI; In order to simplify the large-scale production of three different Trypanosoma cruzi antigens with significant diagnosis value, their coding DNA fragments were fused to produce a single molecule . This tripartite protein was expressed using a shuttle Staphylococcal protein A (SPA) gene fusion vector . The resulting fusion protein location was intracellular when synthesized in Escherichia coli but was also proteolytically degraded during its purification . When the same construct was expressed using the Staphylococcus aureus secretion system, a nondegraded expression product was obtained from the culture medium . A "size effect" seemed to take place in the final yield . The SPA tripartite antigen fusion protein was purified in one step using IgG-Sepharose affinity chromatography . The SPA affinity tail was removed by specific proteolysis with enterokinase and further chromatography on IgG Sepharose . Specific antibodies against individual antigens reacted equally well with the purified tripartite antigen . These results suggest that the simultaneous production of several antigens in a single molecule using the S . aureus secretion system could be a good alternative, when a mixture of cloned antigens is necessary for a strict diagnosis or for immunization experiments.

J Dairy Res, 1996 Nov, 63(4), 543 - 53
Cell cycle regulation of mammary epithelial cell detachment by Staphylococcus aureus; Zavizion B et al.; The effect of Staphylococcus aureus on detachment of bovine mammary epithelial cells in culture was examined . Mammary epithelial cells became detached from fresh monolayers following a 3 h incubation in the presence of Staph . aureus M60 . Two different procedures indicated that cell detachment coincided with the S-phase of the cell cycle . The roles of proteinases, toxins and Ca availability in inducing cell detachment were examined . Addition of the proteinase inhibitor phenylmethylsulphonyl fluoride (1 mM) to the culture medium prevented cell detachment . Addition of a combination of purified staphylococcal proteinases XVI and XVII-B to the culture medium of mammary epithelial cells induced cell detachment in the absence of Staph . aureus . Cell detachment may be caused by a staphylococcal proteinase . However, addition of Ca (10 mM) to the culture medium abolished Staph . aureus-induced cell detachment, despite the fact that proteinase activity was still apparently present . Isogenic mutants of Staph . aureus M60, expressing either alpha or beta toxins but not both, induced cell detachment, but to a lesser extent than the wild type . Thus, Ca and toxins play some role during cell detachment . Clones established from detached cells that were washed and replated showed the same susceptibility to Staph . aureus-induced cell detachment as the parental cells . This indicated that there is no subclone of mammary epithelial cells more sensitive to this effect.

J Hosp Infect, 1996 Nov, 34(3), 205 - 10
When should healthcare workers be screened for methicillin-resistant Staphylococcus aureus?
Lessing MP, Jordens JZ, Bowler IC.
The role of screening of healthcare workers (HCWs) in the control of methicillin-resistant Staphylococcus aureus (MRSA) is controversial . It is recommended in guidelines by expert groups in both North America and the United Kingdom, although the role of MRSA carriage by HCWs in outbreaks is not clearly defined . The present report describes the spread of a distinct strain of MRSA to patients by a single HCW on three separate occasions over 27 months . The isolates from this HCW and patient contacts were shown to be indistinguishable by antibiogram and repetitive extragenic palindromic polymerase chain reaction (REP/PCR); none were typeable by lytic phage-typing . Throat carriage of the MRSA probably recurred in this HCW, despite attempts to eradicate it on three occasions . Over the same period, nine other small clusters were seen in the Oxford Hospital Group, involving 66 patients and 22 HCWs colonized, or occasionally infected, with a variety of MRSA strains . In none of these instances could HCWs be implicated in the initiation of an outbreak . The advantages of a screening policy include the determination of the full extent of MRSA-colonization and work exclusion; the disadvantages include detection of transient nasal carriage, disruption of staff routine and stigmatization . Screening of HCWs can be a valuable tool in the control of MRSA outbreaks but it should be used selectively . This strategy remains an important part of a control programme.

J Hosp Infect, 1996 Nov, 34(3), 197 - 203
Changes in major populations of methicillin-resistant Staphylococcus aureus in Belgium; Wildemauwe C et al.; A total of 102 epidemic methicillin-resistant Staphylococcus aureus (MRSA) isolates collected in 13 Belgian hospitals during two periods (1981-1985 and 1991-1992) were tested for phage-type, for the presence of aminoglycoside-modifying enzymes (AME), and examined by arbitrarily primed polymerase chain reaction (AP-PCR) . All isolates, but five, belonged to a few distinct phage-types of group III . Most isolates expressed a combination of AAC(6')-APH(2") with APH(3')III, and ANT(4',4") or both . Both phage-typing and AME suggested a change in the MRSA population between the two periods but the AP-PCR method revealed only slight differences.

Ann Surg, 1996 Nov, 224(5), 665 - 71
Rapid diagnosis of methicillin-resistant Staphylococcus aureus bacteremia by nested polymerase chain reaction; Kitagawa Y et al.; OBJECTIVE: The purpose of this study was to establish a rapid and sensitive diagnostic method for methicillin-resistant Staphylococcus aureus (MRSA) bacteremia in postoperative patients . SUMMARY BACKGROUND DATA: As a result of diffusion and abuse of third-generation cephalosporin antibiotics in the 1980s in Japan, an outbreak of MRSA infection has been posed . In the field of surgery, severe postoperative infections with MRSA such as MRSA bacteremia, which may lead to multiple organ failure, have emerged with a high mortality . METHODS: Thirty-five patients with high fever (above 38.5 C) or watery diarrhea or both within 2 weeks after gastrointestinal major surgery and 6 healthy volunteers were examined . Nested polymerase chain reaction was used to detect mecA and toxic shock syndrome toxin-1 (TSST-1) genes in blood specimens . RESULTS: The mecA and TSST-1 genes were not detected in the blood samples of any of the six healthy volunteers . In all 12 samples from which MRSA colonies were isolated by blood culture, mecA and TSST-1 genes were detected . Although it took at least 48 hours to identify MRSA by the blood culture method, the presence of mecA and TSST-1 genes was determined by nested polymerase chain reaction method within only 3 to 4 hours after blood sampling . CONCLUSIONS: This method, as a sensitive and rapid monitoring system for MRS bacteremia, would be clinically beneficial for prevention of cross infection and for early determination of appropriate treatment for infected patients.

Arch Biochem Biophys, 1996 Nov 1, 335(1), 102 - 8
Comparison of the beta-toxins from Staphylococcus aureus and Staphylococcus intermedius; Dziewanowska K et al.; The beta-toxins produced by Staphylococcus aureus and Staphylococcus intermedius were purified to homogeneity from culture supernatants . Although the toxin from S . aureus has been throughly studied, less is known about its unique counterpart from S . intermedius . This is the first reported purification and analysis of the S . intermedius beta-toxin . Both toxins have similar enzymatic properties, belong to the class of neutral sphingomyelinases C, and have a high specificity for sphingomyelin . They also hydrolyze lysophosphatidylcholine at a much slower rate, but have no activity toward phosphatidylcholine, phosphatidylethanolamine, or phosphatidylserine . The kinetic parameters determined for both proteins (apparent Km 1.4 mM, Vmax 100 mmol/min/microg protein) are identical . Despite these similarities, the size and amino acid composition of the two beta-toxins differ . Molecular mass values, determined by electrophoresis and gel filtration, indicate that the both enzymes are single polypeptides . The decrease in sphingomyelinase activity of S . aureus beta-toxin upon pretreatment with dithiothreitol (DTT) indicates the presence of a disulfide bond in the protein . In contrast, DTT has no effect on the enzymatic activity of S . intermedius beta-toxin . This observation is consistent with the absence of detectable cysteine residue in the protein . N-terminal amino acid sequences determined for the first 19 residues of both beta-toxins also differ, only nine of the first 19 residues are identical . Further evidence that the two proteins differ was obtained by immunological analysis which demonstrated crossreactivity but a lack of identity.

Antimicrob Agents Chemother, 1996 Nov, 40(11), 2529 - 34
In vivo efficacies of levofloxacin and ciprofloxacin in acute murine hematogenous pyelonephritis induced by methicillin-susceptible and-resistant Staphylococcus aureus strains; Frosco MB et al.; Levofloxacin, the active L-isomer of ofloxacin, has demonstrated strong activity against Staphylococcus aureus both in vitro and in vivo . In a murine model of hematogenous pyelonephritis, the in vivo efficacies of levofloxacin and ciprofloxacin were evaluated against two methicillin-susceptible and two methicillin-resistant S . aureus strains . All four isolates had virtually identical susceptibilities to levofloxacin and ciprofloxacin . Pyelonephritis was induced in carrageenan-primed mice by an intravenous injection of 0.5 ml of 10(7) CFU of methicillin-susceptible S . aureus isolates per ml or 10(8) CFU of methicillin-resistant S . aureus isolates per ml . At 1 h postinfection, the mice were treated orally with levofloxacin or ciprofloxacin once a day or twice a day (total daily dose of 20 to 160 mg/kg of body weight) for 4 days . Mice were euthanized 24 h after the final treatment, and the kidneys were excised and weighed . The kidneys were prepared for histological examination or were homogenized to determine the numbers of CFU per gram of tissue quantitatively . The reduction in the mean log10 number of CFU per gram as a function of total daily dose was recorded . A dose-response analysis showed that levofloxacin was superior to ciprofloxacin for all four isolates at any dose or regimen tested, independent of the methicillin susceptibility of the isolates . By using an inverse prediction technique, the equivalent effective doses of levofloxacin (once a day) were less than those of ciprofloxacin (twice a day) by 5.2 and 3.2 times, respectively, for methicillin-susceptible S . aureus 9039 and 3087 . For methicillin-resistant S . aureus 667 and 2878, the equivalent effective doses of levofloxacin (once a day) were less than those of ciprofloxacin (twice a day) by 4.1 and 6.4 times, respectively . In a separate study, histological examination of all infected, untreated mice showed moderate to marked hematogenous pyelonephritis . Levofloxacin-treated mice (40 mg/kg once a day) showed no evidence of pyelonephritis in the kidneys, whereas the kidneys of mice treated with the same dose of ciprofloxacin showed only a reduction in the severity of the lesions . Treatment with ciprofloxacin (80 mg/kg twice a day) demonstrated a histology comparable to that of treatment with levofloxacin (40 mg/kg once a day) . Levofloxacin (40 mg/kg once a day) reduced the log10 numbers of CFU per gram by 5 log10; however, ciprofloxacin (80 mg/kg twice a day) reduced the numbers of CFU per gram by only 3 log10 . In the present murine model of pyelonephritis, levofloxacin was superior to ciprofloxacin in preventing pyelonephritis and eradicating S . aureus.

Clin Immunol Immunopathol, 1996 Nov, 81(2), 175 - 81
Inhibition of human B cell activation by gold compounds; Hirohata S; The mechanism of action of gold compounds, which are effective in the treatment of rheumatoid arthritis (RA), has not been clearly identified . Although one of the characteristic features of RA is chronic stimulation of B cells, the effects of gold compounds on B cells have not been precisely assessed . We therefore examined the effects of gold sodium thiomalate (GST) on human B cells . IgM production was induced from highly purified B cells obtained from healthy donors by stimulation with Staphylococcus aureus Cowan 1 (SA) plus IL-2 . T cell proliferation and IFN-gamma production were induced from highly purified T cells by stimulation with immobilized mAb to CD3 . As little as 0.1 microg/ml (0.25 microM) GST almost completely suppressed B cell IgM production, whereas it did not suppress T cell proliferation or IFN-gamma production . The inhibition of IgM production by GST is not due to its thiomalate, but is most likely due to its gold components, since thiomalate alone did not inhibit IgM production . GST was required at the initiation of cultures to exert optimal suppressive effects on IgM production . Moreover, GST suppressed the expression of IL-2R (CD25) and transferrin receptor (CD71) on SA-stimulated B cells . These results indicate that GST preferentially inhibits the function of B cells at concentrations much lower than those which inhibit the function of T cells by interfering with the initial activation of B cells . The direct inhibitory effects of GST on human B cell activation described here may contribute at least in part to its therapeutic effect in RA.

FEMS Microbiol Lett, 1996 Nov 1, 144(2-3), 241 - 7
The combined effects of plasma and hydrogel coating on adhesion of Staphylococcus epidermidis and Staphylococcus aureus to polyurethane catheters; John SF et al.; The adhesion of three Staphylococcus epidermidis and three S aureus clinical isolates, to uncoated and hydrogel-coated polyurethane catheters was tested, following pretreatment of catheters with human plasma . Plasma significantly decreased the adhesion of S . epidermidis strains to uncoated polyurethane catheters, but had no significant effect on the adhesion to hydrogel-coated catheters . The influence of plasma on adhesion of S . aureus strains to catheters was strain dependent . Plasma significantly increased the adhesion of one strain (SA6) to uncoated catheters . For two other strains (SA3 and SA14) plasma produced no clear effect on their adhesion to uncoated catheters; adhesion values for each strain showed either a small but significant increase or a replicate-dependent increase or decrease . However, plasma significantly increased the adhesion of all S . aureus strains to hydrogel-coated polyurethane catheters . Overall, with the exception of one batch culture of S . epidermidis strain SE3 tested, attachment to plasma-treated hydrogel coated catheters was statistically significantly lower, by up to 85%, than attachment to plasma-treated uncoated catheters for both S . epidermidis and S . aureus.

J Infect Dis, 1996 Nov, 174(5), 1001 - 9
Penicillin G-induced microbicidal activity of endothelial cells cultured on gelfoam blocks; Zhang B et al.; A body of evidence has surfaced documenting the ability of endothelial cells cultured on monolayers to phagocytose but not kill bacteria . Several years ago, a new three-dimensional endothelial cell culturing model was developed, which simulated the morphology of the endothelium in small vessels and capillaries . Given that endothelial cells may be derived from the same pluripotent stem cells as macrophages, the question of whether endothelial cells might phagocytose and kill bacteria was explored . Endothelial cells grown on Gelfoam blocks exhibited bactericidal activity towards Staphylococcus aureus, reaching maximal killing of > 90% after 2 h . Evidence documents the involvement of bacterial adherence to the plasma membrane of the endothelial cell . This is followed by phagocytosis of S . aureus, leading to intracellular killing . Penicillin G, included in the endothelial cell growth medium, was found to be a critical factor in the bactericidal activity demonstrated by Gelfoam blocks laden with endothelial cells.

Endocrinology, 1996 Nov, 137(11), 4671 - 6
Stable and diffusible pools of nucleotides in pancreatic islet cells; Detimary P et al.; Adenine nucleotides are thought to serve as second messengers in the control of beta-cell function by glucose, e.g . by regulating the activity of ATP-dependent K+ channels . However, their localization in different intracellular pools may mask the biologically relevant changes and complicate the interpretation of measurements in whole cells . The plasma membrane of mouse islet cells was selectively permeabilized by the alpha-toxin from Staphylococcus aureus to allow diffusion of cytoplasmic nucleotides . After permeabilization of cells from freshly isolated islets, approximately 68% of ATP, 45% of ADP, and 52% of AMP rapidly diffused out of the cells, whereas the insulin content hardly varied . The nondiffusible pool of nucleotides was stable for at least 90 min at 4 C, which suggests that it is contained in cellular organelles . The size of this nondiffusible pool decreased proportionally to insulin stores when these were lowered by stimulating secretion to different degrees during culture before permeabilization . From these results, it can be calculated that nondiffusible nucleotides are mainly contained in insulin secretory granules, with a small proportion in another, probably mitochondrial, compartment . Approximately 80% GTP and 30% GDP were present in the diffusible pool, and their relative proportions in the granular pool were only about 20% that of adenine nucleotides . Incubation of the cells in 20 instead of 2 mM glucose before permeabilization did not affect the nondiffusible pool, which indicates that the increase in the ATP/ADP ratio measured in intact cells occurred in the diffusible pool . Cytoplasmic nucleotide levels could be evaluated by subtracting the nondiffusible pool from the measurements in intact cells . It emerges that glucose induces large changes in the ATP/ADP ratio in the cytoplasmic pool, and that these changes are largely due to a fall in ADP.

J Immunol, 1996 Nov 1, 157(9), 4133 - 40
Escherichia coli hemolysin and Staphylococcus aureas alpha-toxin potently induce neutrophil adhesion to cultured human endothelial cells; Krull M et al.; Adhesion of polymorphonuclear leukocytes (PMN) to endothelial cells is an essential step in inflammatory reactions . We characterized the effects of two important bacterial exotoxins, Escherichia coli hemolysin (HlyA) and Staphylococcus aureus alpha-toxin (S . alpha-toxin) on PMN adhesion to cultured HUVEC . Both toxins increased adherence of human PMN to HUVEC in a dose- and time-dependent manner, peaking after 30 min at 0.01 hemolytic units/ml HlyA or 0.5 microg/ml S . alpha-toxin . Pretreatment of HUVEC with anti-P-selectin mAbs or of PMN with anti-CD11b/CD18 mAb reduced HlyA- and S . alpha-toxin-related cell adhesion significantly . Increased P-selectin expression on toxin-treated endothelial cells was demonstrated by cell surface ELISA . Compared with endotoxin, HlyA and S . alpha-toxin did not induce the expression of E-selectin, ICAM-1, or VCAM-1 . FACS analysis showed increased CD11b/CD18 expression on HlyA-, but not on S . alpha-toxin-stimulated PMN . Platelet-activating factor, an important costimulatory factor for PMN adhesion and activation, was also active in the exotoxin-stimulated adhesion system, as evidenced by studies using the platelet-activating factor receptor antagonist BN50727 . HPLC analysis of endothelial cell extracts confirmed enhanced toxin-mediated PAF synthesis . The capacity of exotoxins to stimulate PMN adhesion to endothelial cells may be relevant in patients with severe local or systemic bacterial infections.

Infect Immun, 1996 Nov, 64(11), 4520 - 4
Antibacterial activity of antileukoprotease; Hiemstra PS et al.; Antileukoprotease (ALP), or secretory leukocyte proteinase inhibitor, is an endogenous inhibitor of serine proteinases that is present in various external secretions . ALP, one of the major inhibitors of serine proteinases present in the human lung, is a potent reversible inhibitor of elastase and, to a lesser extent, of cathepsin G . In equine neutrophils, an antimicrobial polypeptide that has some of the characteristics of ALP has been identified (M . A . Couto, S . S . L . Harwig, J . S . Cullor, J . P . Hughes, and R . I . Lehrer, Infect . Immun . 60:5042-5047, 1992) . This report, together with the cationic nature of ALP, led us to investigate the antimicrobial activity of ALP . ALP was shown to display marked in vitro antibacterial activity against Escherichia coli and Staphylococcus aureus . On a molar basis, the activity of ALP was lower than that of two other cationic antimicrobial polypeptides, lysozyme and defensin . ALP comprises two homologous domains: its proteinase-inhibitory activities are known to be located in the second COOH-terminal domain, and the function of its first NH2-terminal domain is largely unknown . Incubation of intact ALP or its isolated first domain with E . coli or S . aureus resulted in killing of these bacteria, whereas its second domain displayed very little antibacterial activity . Together these data suggest a putative antimicrobial role for the first domain of ALP and indicate that its antimicrobial activity may equip ALP to contribute to host defense against infection.

Eur J Nucl Med, 1996 Nov, 23(11), 1536 - 9
Retention of technetium-99m in infectious foci in rats after release from technetium-99m labelled human non-specific polyclonal immunoglobulin G: a dual-label study with hydrazinonicotinamido and iminothiolano immunoglobulin; Claessens RA et al.; In an effort to contribute to the understanding of the mechanism of uptake of technetium-99m labelled non-specific polyclonal human immunoglobulin G (hIgG) in inflammatory lesions we compared the tissue distribution of double-labelled 99mTc-hydrazinonicotinamido (HYNIC) hIgG-14C and 99mTc-iminothiolano hIgG-14C in groups of five Wistar rats with a Staphylococcus aureus infection of the left calf muscle between 2 h p.i . and 24 h p.i . The stability of the two double-labelled hIgG preparations was evaluated in vitro and in plasma in vivo by high-performance liquid chromatography (HPLC) analysis . At 24 h after injection of 99mTc-HYNIC-hIgG-14C the abscess uptake of 99mTc (1.5% ID/g+/-0.2% ID/g) was significantly higher (P<0.01) than the 14C uptake (1.0% ID/g+/-0.1% ID/g) . After injection of 99mTc-iminothiolano hIgG-14C no significant difference (P=0.08) was found between the abscess uptake of the two radionuclides at 24 h p.i . (99mTc: 0.8% ID/g+/-0.1% ID/g; 14C: 0.90% ID/g+/-0.09% ID/g) . HPLC analysis of plasma samples revealed release of 99mTc from both double-labelled immunoglobulin preparations . This phenomenon was more pronounced for iminothiolano hIgG than for HYNIC hIgG (43% vs 18%) . In most tissues other than abscesses significant differences were also found between the 99mTc and the corresponding 14C uptake . Our results demonstrate that the chemical form in which 99mTc is bound to hIgG severely influences its release from hIgG and its retention in infections.

Eur J Nucl Med, 1996 Nov, 23(11), 1531 - 5
Different behaviour of radioiodinated human recombinant interleukin-1 and its receptor antagonist in an animal model of infection; van der Laken CJ et al.; Recently, we demonstrated that radiolabelled interleukin-1alpha (IL-1) specifically accumulates in focal infection in mice through interaction with its receptor . Unfortunately, systemic side-effects of IL-1 limit its clinical application . We investigated whether this problem could be circumvented by using the interleukin-1 receptor antagonist (IL-1ra), an equally sized protein that binds to the same receptors as IL-1 without induction of biological effects . Biodistribution of 125I-IL-1 and 125I-IL-1ra was determined in Swiss mice with Staphylococcus aureus-induced abscesses in the left calf muscle at 4, 12, 24 and 48 h after injection of either 0.4 MBq 125I-IL-1 or 0.4 MBq 125I-IL-1ra . In vitro, the proteins displayed similar binding characteristics . High-performance liquid chromatographic analysis revealed a tendency for IL-1ra to associate with serum proteins . Both proteins rapidly cleared from most organs . However, the abscess uptake of 125I-IL-1ra was significantly lower than that of 125I-IL-1 at all time points (48 h p.i.: 0.06+/-0 . 01%ID/g vs 0.60+/-0.04%ID/g; P<0.02) . The abscess-to-contralateral muscle ratios did not exceed 15.5+/-2.9 for 125I-IL-1ra, while the ratios for 125I-IL-1 reached 46.9+/-5.7 at 48 h p.i . Despite similar in vitro receptor binding, the abscess uptake of IL-1ra was much lower than that of IL-1 . The interaction of IL-1ra with serum proteins in vivo may reduce its availability for receptor binding in the infection . Although on theoretical grounds IL-1ra is very interesting, these characteristics will prevent its development as a clinically useful radiopharmaceutical to image infection.

Gene, 1996 Oct 31, 178(1-2), 97 - 106
NBP35 encodes an essential and evolutionary conserved protein in Saccharomyces cerevisiae with homology to a superfamily of bacterial ATPases; Vitale G et al.; We have cloned a novel and essential gene, NBP35, from Saccharomyces cerevisiae that encodes a putative Nucleotide Binding Protein of 35 kDa . Sequence analysis revealed structural homology of Nbp35p with a family of bacterial ATPases involved in cell division processes and chromosome partitioning . A search in databases identified closely related sequences from yeast and higher eukaryotes, suggesting a conserved function for this family of proteins . By indirect immunofluorescence, a tagged version of Nbp35p carrying two immunoglobulin G-binding domains derived from Staphylococcus aureus Protein A was localised to the nucleus . A single amino-acid substitution in the conserved nucleotide-binding motif of Nbp35p renders the protein non-functional . Furthermore, a conserved cluster of four cysteines in the N-terminal end of the protein is also required for an essential role of Nbp35p.

J Immunol Methods, 1996 Oct 30, 198(1), 67 - 77
Chicken anti-protein A prevents Staphylococcus aureus protein A from binding to human and rabbit IgG in immunoassays and eliminates most false positive results; Hoffman WL et al.; This report demonstrates that chicken anti-protein A can prevent both soluble and surface-bound Staphylococcal protein A from binding to either human or rabbit IgG . In an ELISA assay, chicken anti-protein A prevented > 98% of the soluble protein A from binding to the human IgG-Fc coat . In a blotting assay, chicken anti-protein A prevented the membrane-bound protein A from interacting with the human IgG probe . When intact S . aureus (Cowan I strain) was bound to the surface of a microassay plate, chicken anti-protein A blocked > 98% of the cell wall protein A and permitted the probing of the surface components with human IgG . In another immunoassay, rabbit anti-enterotoxin A IgG was used to measure enterotoxin A concentrations in S . aureus culture medium supernatants after soluble protein A was blocked by chicken anti-protein A . Thus, the binding of chicken anti-protein A to protein A almost completely eliminates false positive results and permits the measurement of specific antibodies or antigens in a variety immunoassays where protein A is present.

Ann N Y Acad Sci, 1996 Oct 25, 797, 285 - 7
Prophylaxis with the immunomodulator PGG glucan enhances antibiotic efficacy in rats infected with antibiotic-resistant bacteria; Tzianabos AO et al.; The emergence of multiple antibiotic-resistant microorganisms has led to a search for alternatives to traditional therapeutic regimens . PGG glucan is a soluble beta-glucan immunomodulator that selectively enhances the microbicidal activities of neutrophils and macrophages without stimulating proinflammatory cytokine production . In the present studies, we examined the ability of PGG glucan to act in concert with antibiotics to decrease mortality in a rat model of intraabdominal sepsis using antibiotic-resistant bacteria as infectious inocula . Results of these studies demonstrated that prophylaxis with PGG glucan in combination with antibiotics provided enhanced protection against lethal challenge with Esherichia coli or Staphylococcus aureus as compared with the use of antibiotics alone.

Presse Med, 1996 Oct 19, 25(31), 1441 - 6
{Nosocomial pneumonia in intensive care units}; Fagon JY et al.; Nosocomial pneumonia is associated with substantial morbidity and mortality . Patients treated with mechanical ventilation have the highest risk for developing this intensive care unit acquired infection . Gram-negative bacilli are the predominant organisms responsible for pneumonia in this setting . However, Staphylococcus aureus has recently emerged as a significant isolate . Nosocomial pneumonia is difficult to diagnose clinically in ventilated patients because fever, lung infiltrate on chest X-ray, leukocytosis are frequent in severely ill patients under mechanical ventilation whatever lung infection is present or not and because lower respiratory tract of such patients is colonized by potentially pathogenic bacteria independently of the presence of true lung infection; thus, different diagnostic strategies are proposed . Our personal bias is that using bronchoscopic techniques to obtain bronchoalveolar lavage and protected-brush specimens permits us to devise a therapeutic strategy that is superior to one based only on clinical evaluation . Measures for prevention of nosocomial infection are essential to decrease the incidence of nosocomial pneumonia and the emergence of multiresistant pathogens.

J Immunol, 1996 Oct 15, 157(8), 3298 - 304
Enterotoxin septic shock protection and deficient T helper 2 cytokine production in growth hormone transgenic mice; Gonzalo JA et al.; Neuroendocrine hormones have long been thought to play a role in lymphoid development and function . In particular, growth hormone has been shown to mediate thymic development as well as to promote T cell engraftment in severe combined immunodeficiency mice . Murine T helper cells are classified into two subsets based on their cytokine production pattern . Here, we report that transgenic mice for bovine growth hormone show significant alterations in T cell function and decreased capability for cytokine production, an effect that is more acute in T helper cells as measured by their inability to produce IL-4 upon in vivo injection with Staphylococcus aureus enterotoxin B . Furthermore, upon immunization with conventional Ags, growth hormone transgenic mice produce an altered Ig isotype pattern characterized by a response shift from IgG1 in nontransgenic mice to IgG2 in transgenic mice . The impaired T cell responses correlated with survival from septic shock mediated by bacterial enterotoxins . We conclude that growth hormone may have the potential of regulating immune responses in pathologic processes associated with hyperactivation of T cells or with massive cytokine production.

J Am Vet Med Assoc, 1996 Oct 15, 209(8), 1457 - 63
Evaluation of udder health and mastitis in llamas; Rowan LL et al.; OBJECTIVE: To investigate intramammary infections in llamas, identify the pathogens responsible, and determine whether effects of intramammary infection could be detected by use of mastitis indicator tests commonly used for cows . DESIGN: Observational study . ANIMALS: 100 llamas on 10 farms . PROCEDURE: Milk samples were evaluated by bacterial culturing and by determination of somatic cell count (SCC), using direct microscopic and automated counting methods, California Mastitis Test score, pH, and N-acetyl-beta-d-glucosaminidase activity . Correlation coefficients were determined among the various mastitis indicator tests, and test results were determined for milk from infected and uninfected glands . RESULTS: Evidence of intramammary infection was evident in 76 of 369 (21%) milk samples, with 54 of 94 (57%) llamas having at least 1 infected gland . Staphylococcus sp other than Staphylococcus aureus were the predominant pathogens . None of the llamas had clinical signs of mastitis, and significant differences were not detected in SCC, California Mastitis Test score, pH, or N-acetyl-beta-d-glucosaminidase activity between infected and uninfected samples . California Mastitis Test scores were negative or trace for 307 of 313 (98%) samples, and SCC were low . In contrast, pH and N-acetyl-beta-d-glucosaminidase activity of milk from uninfected glands were higher than values reported for milk from uninfected cows, and neither variable was significantly correlated with the number of somatic cells in samples of llama milk . CLINICAL IMPLICATIONS: Although intramammary infections develop in llamas, inflammation (mastitis) appears to be rare . Values for mastitis indicator tests used for cows cannot be directly extrapolated to llamas . Subclinical mastitis is apparently not an important problem in llamas in the United States.

J Toxicol Environ Health, 1996 Oct 11, 49(2), 127 - 43
Reaction of human hemoglobin toward the alkylating agent S-(2-chloroethyl)glutathione; Erve JC et al.; In order to investigate if hemoglobin might serve as a biomarker of exposure for 1,2-dichloroethane (DCE) encountered in the workplace, human hemoglobin was alkylated at physiologic pH by the episulfonium ion of S-(2-chloroethyl)glutathione (CEG) . In vitro alkylation resulted in three alkylation products on the alpha chain and at least two alkylation products on the beta chain as determined directly by matrix-assisted laser desorption-ionization mass spectrometry . To ascertain if the site of alkylation was the reactive sulfhydryl present at cysteine-93 on the beta chain of hemoglobin (beta-93 Cys), a spectrophotometric assay using 4,4'-dithiodipyridine was used to measure the free sulfhydryl groups before and after treatment of hemoglobin with various amounts of CEG . Results indicate that the episulfonium ion did not react substantially at beta-93 Cys, as there was no measurable decrease in the sulfhydryl to hemoglobin ratio, even with a large excess of CEG . In contrast, iodoacetamide did react with the sulfhydryl groups and gave a dose-dependent decrease in the sulfhydryl to hemoglobin ratio as measured by this assay . CEG-treated hemoglobin was digested with Staphylococcus aureus endoproteinase Glu-C and the digest was analyzed by fast atom bombardment mass spectrometry . Only one peak in the FAB mass spectrum could correspond to a peptide modified by the episulfonium ion of CEG . These results indicate that although the episulfonium ion of CEG does alkylate human hemoglobin, beta-93 Cys is not the major alkylation target.

Microb Drug Resist, 1996 Fall, 2(3), 343 - 51
Testing the efficacy of a molecular surveillance network: methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium (VREF) genotypes in six hospitals in the metropolitan New York City area . The BARG Initiative Pilot Study Group . Bacterial Antibiotic Resistance Group; de Lencastre H et al.; Molecular fingerprinting techniques are rapidly becoming indispensable tools for hospital epidemiology . On the other hand, the relative complexity and unfamiliarity of these techniques to most hospital diagnostic laboratories limit their usefulness . In an attempt to provide a solution for this dilemma, we tested the feasibility and efficacy of a cooperative venture in which molecular typing of isolates recovered from patients in six hospitals was performed at two microbiology research laboratories with expertise in these techniques . In a small preliminary study, 30 methicillin-resistant Staphylococcus aureus (MRSA) and 30 vancomycin-resistant Enterococcus faecium (VREF) isolates were collected over a 3-week period from six hospitals in the metropolitan New York area and transported to the Laboratory of Microbiology at The Rockefeller University during the summer months of 1994 . Nineteen of the 27 confirmed MRSA isolates were closely related strains carrying the same mecA and the same Tn554 polymorphs in a pulsed-field gel electrophoresis (PFGE) background represented by closely related subtypes of a single pattern, indicating the wide distribution of this MRSA clone among the participating hospitals . Typing of the same 27 MRSA isolates was also performed at the Tuberculosis Center of the Public Health Research Institute and identical results were obtained . The 29 confirmed VREF isolates were highly heterogeneous and belonged to as many as 23 distinct clonal types as defined by PFGE patterns and probing with vanA . Characterization of the 60 isolates by these methods was completed in one month of full-time effort by a single experienced laboratory assistant guided by a doctoral-level expert in molecular fingerprinting techniques . The collection of samples for both MRSA and VREF was not intended to address epidemiological questions but to determine the feasibility of a multicenter study . On the basis of our preliminary findings we are encouraged that a larger cooperative effort is possible and with the correct sampling method we believe that epidemiological and surveillance studies could be accomplished that would provide a tracking system to assist hospitals, clinics, and chronic care facilities in controlling the spread of multidrug-resistant pathogens.

Microb Drug Resist, 1996 Fall, 2(3), 331 - 41
Characterization of methicillin-resistant Staphylococcus aureus isolates from Portuguese hospitals by multiple genotyping methods; Aires de Sousa M et al.; One hundred and eighty-three methicillin-resistant Staphylococcus aureus (MRSA) isolates from eight different Portuguese hospitals were genetically typed by random amplification of polymorphic DNA (RAPD) employing different oligonucleotide primers . Fourteen different RAPD genotypes were identified . A subset of the same strains was also characterized by pulsed-field gel electrophoresis (PFGE) and/or hybridization using mecA and Tn554 probes . In the majority of cases, the different genotyping methods have identified the same MRSA clones . However, PFGE combined with the DNA probes was clearly the method providing higher resolution . Most strains that have already been identified by PFGE and DNA probes as members of the widely spread Iberian clone of MRSA generated a common RAPD genotype . The most prevalent Iberian clone was not detected in a collection of MRSA from Poland that was also examined by RAPD . On the other hand, MRSA strains second most frequent in prevalence in the Portuguese and Polish collection appear to be identical by RAPD, indicating extensive geographic spread of this particular clone . No correlation was apparent between epidemic behavior and the number of protein A gene repeats in this particular collection of MRSA strains.

Microb Drug Resist, 1996 Fall, 2(3), 319 - 29
Tracing the origin of an outbreak of methicillin-resistant Staphylococcus aureus infections in a Portuguese hospital by molecular fingerprinting methods; Sanches IS et al.; Seventy-six methicillin-resistant Staphylococcus aureus (MRSA) isolates were collected from July 1992 to May 1995 at a 400-bed district hospital in the northeast of Portugal . During the second half of the surveillance period, in July of 1994, an outbreak was detected in the orthopedic ward . Thirty-three (out of the 76) MRSA strains were recovered only in this ward during the outbreak period . All strains were characterized by a variety of genomic fingerprints . Hybridization of ClaI and SmaI restriction digests with the mecA- and Tn554-specific DNA probes was used to identify polymorphism and determine chromosomal location of these determinants, and pulsed-field gel electrophoretic analysis of SmaI digests was used to determine chromosomal backgrounds . All strains recovered during the outbreak in the orthopedic ward were found to belong to a single clone that carried the mecA polymorph I, Tn554 type E in a macrorestriction background called H (clone I::E::H1), which was identified in 18 patients, and 5 health care personnel and from a fomite sample, and was traced to a single transfer patient admitted to the hospital at the beginning of the outbreak . The new clone I::E::H1 differed only in the macrorestriction profile from the MRSA clone previously dominant in this hospital, known as Iberian epidemic clone I::E::A, which has already been identified in several Spanish and Portuguese hospitals.

Pneumologie, 1996 Oct, 50(10), 706 - 11
{MRSA (methicillin-resistant Staphylococcus aureus) infections in patients with pulmonary diseases}; Erbes R et al.; Methicillin-resistant Staphylococcus aureus (MRSA) has become a major nosocomial pathogen . We investigated MRSA-infections in patients with pulmonary diseases referring to epidemiological aspects . Between 9/92 and 2/92 we found MRSA-infections in our hospital in 24 patients (11 female, 13 male, average age 54.6 years) . Clinical presentation, main and accompanying disorders and previous antibiotic therapy regimens were registered . Strains were typed using DNA-RFLP and lysotyping . MRSA detection were done in specimen from sputum (12/24) and from the bronchial secret (9/24) . In 18/24 cases the MRSA-colonisation was associated with infection . In 15/24 cases the first acquisition of MRSA happened in our hospital, 6/24 times the germ was carried off other institutions and in 3/24 cases it was possibly community acquired . Most frequently patients suffered from bronchial cancer (6/24), from chronical bronchitis (5/24), from pneumonia (4/24) or Cystic fibrosis (4/24) . Usually the patients showed other severe comorbidity . 13/24 patients had an antibiotic course before detecting MRSA . Typing revealed a strain already known in different hospitals of Berlin, another known strain of northern Germany and two so far unknown strains . Of interest was a different behaviour of resistance and the lost of resistance of strains in the course . MRSA-infection in pulmonary medicine emerged as a problem mostly in patients with multimorbidity and severe underlying diseases . Change of resistance in strains and new strains were observed.

Monaldi Arch Chest Dis, 1996 Oct, 51(5), 387 - 90
Mixed infection by Staphylococcus and Candida, and Wegener's granulomatosis; Valenti S et al.; We describe the case of a patient who initially presented with pneumonia from Staphylococcus aureus and Candida parapsilosis, which was resolved with antibiotic treatment, but reappeared 6 months later as full-blown Wegener's granulomatosis . The possible pathogenetic correlations between infective agents, in particular Staphylococcus aureus and Candida, and Wegener's granulomatosis are discussed.

Biosci Biotechnol Biochem, 1996 Oct, 60(10), 1571 - 4
Detection of protein A produced by Staphylococcus aureus with a fiber-optic-based biosensor; Chang YH et al.; Staphylococcus aureus is a pathogen important in causing human infections and intoxication . A sensitive fiber-optic that produces evanescent waves was developed for the detection of protein A, a product secreted only by S . aureus . In the immunosensor, a 40-mV argon-ion laser that generated laser light at 488 nm was used together with plastic optical fiber and antibodies to protein A were physically adsorbed onto the fiber . The principle of the detection involved a sandwich immunoassay with fluorescein isothiocyanate conjugated with anti-(protein A) immunoglobulin G to produce signals of the antigen-antibody reaction . The detection limit was 1 ng of protein A per milliliter . The fiber-optic immunosensor could be used for rapid and specific detection of S . aureus in clinical specimens and foods.

Respir Med, 1996 Oct, 90(9), 531 - 7
Predictors of Staphylococcus aureus pneumonia associated with human immunodeficiency virus infection; Tumbarello M et al.; This study is based on a retrospective logistic regression analysis of all human immunodeficiency virus (HIV)-infected patients with Staphylococcus aureus pneumonia (SAP) admitted to the Department of Infectious Diseases, Catholic University, Rome, Italy between January 1986 and December 1994 . Nineteen patients with 24 episodes of SAP were enrolled in the study . A control group of 38 HIV-infected patients without pneumonia was included . The attack rate of SAP was 8.31/1000 HIV-related hospital admissions and the frequency, out of the total number of bacterial pneumonia observed in the study period, was 16% (24 of 154 patients) . The large majority of SAP was community acquired . On the univariate analysis, intravenous drug abuse (IVDA) (P = 0.02), history of previous Pneumocystis carinii pneumonia (PCP) (P = 0.03) and cirrhosis (P = 0.03) were significant risk factors for SAP . In addition, IVDA and previous PCP were independent risk factors on multivariate analysis . All patients presented with fever associated with cough (74%), chest pain (26%) or shortness of breath (37%) . Chest X-ray documented lobar pneumonia (78%), predominantly in the lower lobes, consolidation with cavitation (11%), and interstitial-nodular infiltrates (11%) . Pleural effusion was present in 31% of patients . The response to therapy was favourable in 79% of patients . Recurrence occurred in 26% and death occurred in 21% of patients . Death was significantly associated with the low level (< 50 mm-3) of circulating T CD4+ cells (P = 0.03) and the recurrence of pneumonia (P = 0.03) . In conclusion, the present study indicates that S . aureus is an important aetiologic agent of bacterial pneumonia in HIV-infected patients, especially if they are drug abusers with previous PCP.

Vet Immunol Immunopathol, 1996 Oct, 53(3-4), 249 - 56
In vitro responses of cervine macrophages to bacterial stimulants; Cross ML et al.; The function of cervine (deer) mononuclear phagocytes is poorly defined . In the present study, the potential of cervine macrophages to generate phagocytic and immunoregulatory responses following stimulation with bacterial products was investigated . Blood-derived macrophages of red deer were cultured in vitro with particulate stimulants (Mycobacterium bovis BCG and Staphylococcus aureus SAC) or soluble stimulants (M . bovis PPD and Escherichia coli LPS), prior to assessment of phagocytic responses, prostaglandin secretion and cytokine production . Particulate stimulants induced vigorous phagocytic responses (superoxide anion generation, lysosomal enzyme release), secretion of prostaglandin E2 and transcription of mRNA specific for the cytokines IL-1 beta, IL-10 and TNF alpha, while soluble products invoked weaker responses . These results are discussed in relation to the role of cervine mononuclear phagocytes in regulating and participating in inflammatory and immune processes relevant to bacterial challenge.

J Antimicrob Chemother, 1996 Oct, 38(4), 589 - 97
The concentration-independent effect of monoexponential and biexponential decay in vancomycin concentrations on the killing of Staphylococcus aureus under aerobic and anaerobic conditions; Larsson AJ et al.; An in-vitro pharmacodynamic system was used to generate time-kill curves to demonstrate the concentration-independent pharmacodynamics of vancomycin against Staphylococcus aureus ATCC 29213 . Initial vancomycin concentrations of 5, 10, 20 and 40 mg/L were studied monoexponentially while simulating a 6 h half-life . One parallel experiment was performed in duplicate using an initial peak concentration of 40 mg/L where both a distribution alpha-phase half-life of 0.66 h for 1 h and an elimination beta-phase half-life of 6 h for 11 h were simulated to determine if the transient distribution phase concentrations of vancomycin have any impact on bacterial killing beyond that provided by the elimination phase concentrations . Additionally, two monoexponential experiments with peak concentrations of 40 and 20 mg/L and a half-life of 6 h were repeated in an anaerobic chamber to determine if killing of S . aureus was affected . The time to achieve a 3 log10 kill was calculated from the linear portion of the regression line and averaged (mean +/- S.D.) 9.0 +/- 1.4 h for all aerobic monoexponential experiments and was 8.4 and 8.6 h for the aerobic biexponential experiments (P > 0.05) . For the anaerobic studies, the times to reach 3 log10 kill were significantly greater averaging 18.9 +/- 1.7 h . The slopes of the bacterial kill curves were virtually identical for both monoexponential and biexponential aerobic experiments averaging -0.34 +/- 0.04, yet significantly different from the anaerobic bacterial kill curve slopes of -0.16 +/- 0.015 (P < 0.05) . Time-kill curve analyses suggest that varying the concentration of vancomycin does not affect the rate or extent of bacterial killing aerobically or anaerobically against S . aureus and more efficient killing was achieved under aerobic conditions . The simulated distribution phase concentrations did not contribute to more effective killing of this strain of S . aureus.

Infect Immun, 1996 Oct, 64(10), 4288 - 98
Altered regulation of inducible nitric oxide synthase expression in macrophages from senescent mice; Chen LC et al.; We investigated the capacity of mouse macrophages obtained from senescent animals to respond in vitro to microbial stimuli . Significant hypersecretion of nitric oxide (NO) was observed in thioglycolate-elicited macrophages from senescent mice compared with those obtained from young mice in response to lipopolysaccharide (LPS) . In contrast, both cell populations manifested equivalent responses to LPS with respect to tumor necrosis factor alpha secretion . Further, macrophages from senescent animals also showed potentiated responses to both zymosan and heat-killed Staphylococcus aureus, as assessed by NO production . Both cell populations were equivalently inhibited by a competitive inhibitor of NO synthase NG-monomethyl-L-arginine . Since endogenous beta interferon (IFN-beta) is recognized as an essential cofactor for LPS-induced NO production by macrophages, we investigated the role of IFN-beta in enhancing the capacity of both macrophage populations for LPS-induced NO production . Macrophages from young mice were minimally activated by LPS alone to express inducible NO synthase (iNOS), and the response was significantly potentiated by the addition of IFN-beta . These findings were confirmed by immunocytochemical staining of iNOS in which the frequency of iNOS-positive cells in response to LPS was enhanced in the presence of IFN-beta . Reverse transcription-PCR analyses revealed that macrophages from senescent animals produced larger amounts of iNOS mRNA in response to LPS . Further, exogenous IFN-beta potentiated iNOS mRNA expression in macrophages from young mice . In contrast, the frequency of LPS-activated macrophages for iNOS expression was markedly increased during senescence and addition of IFN-beta did not significantly change this frequency . These results correlated with reverse transcription PCR data showing high levels of iNOS mRNA in LPS-stimulated macrophages from senescent mice . LPS-induced NO production in macrophages from both young and senescent mice was inhibited by neutralizing antibody to either IFN-beta or IFN-gamma . Mixed cultures of macrophages from young and senescent mice stimulated with LPS manifested significantly enhanced NO production relative to that which would be predicted from an additive response of the two macrophage populations stimulated separately . The differential responsiveness of NO production observed with thioglycolate-elicited macrophages from young and senescent mice was also observed in resident macrophages but, interestingly, not in bone marrow culture-derived macrophages . These results suggest that environmental factors may be responsible for the potentiated NO responses of macrophages from senescent mice . Collectively, these data suggest that macrophages from senescent animals manifest an altered mechanism for regulation of macrophage function in NO production and iNOS expression by constitutive and/or induced expression of autoregulatory cytokines.

Infect Immun, 1996 Oct, 64(10), 4231 - 5
Gastrointestinal colonization by methicillin-resistant Staphylococcus aureus in immunosuppressed mice; Kato-Matsunaga N et al.; ICR mice were inoculated intranasally with methicillin-resistant Staphylococcus aureus (MRSA) N133, and the inoculated MRSA was quantitatively recovered from the ceca and feces . The viable counts of the MRSA recovered from ceca correlated well with those from feces . Some mice eliminated MRSA from the cecum by 14 days after inoculation . Intraperitoneal administration of cyclophosphamide at a dose of 200 mg/kg 3 days before inoculation inhibited the elimination of the MRSA from both ceca and feces . All mice treated with cyclophosphamide excreted more than 10(4) CFU of the MRSA per g of feces for at least 70 days, indicating persistent colonization of the MRSA in the gastrointestinal tract . Some beta-lactam antibiotics decreased the colonization level, but others did not . The colonization level was suggested to depend on the antibacterial activity of the antibiotic against the MRSA and the degree of disturbance of intestinal flora by the antibiotic.

Zentralbl Veterinarmed B, 1996 Oct, 43(8), 475 - 82
Microbiological diagnoses of chronic otitis externa in the dog; Blanco JL et al.; The microbiological characteristics of otic exudates from 26 dogs with chronic otitis externa was studied with special reference to the implication of yeasts in the aetiology of the disease . A high frequency of yeasts and Staphylococcus aureus were isolated, alone or in association . In reference to the yeasts, there was a clear predominance of the genus Candida (48% of the total yeasts) . Malassezia (Pytirosporum) represented only 3% of the isolates . It can be concluded that yeasts have an important role in the pathogenicity of this disease . For the microbiological diagnosis of otitis externa, we recommend the simultaneous use of Columbia/5% Sheep Blood Agar and Sabouraud-Dextrose without antibiotic addition, the use of 37 degrees C as the incubation temperature and direct microscopic observation of the sample before culture.

Int Immunol, 1996 Oct, 8(10), 1603 - 7
Linomide, an immunomodulator that inhibits Th1 cytokine gene expression; Arad G et al.; Linomide (LS-2616, quinoline-3-carboxamide) has strong immunomodulating effects in animal models, inhibiting toxic shock, progressive autoimmune disease and cancer . In humans, linomide strongly reduced the appearance of new lesions in multiple sclerosis yet enhanced immune responses after bone marrow transplantation . In contrast to these clear effects in vivo, attempts to show an effect of linomide in vitro have not been successful and its mode of action remains to be elucidated . Here we show that at concentrations effective in vivo, linomide is active on human peripheral blood mononuclear cells (PBMC), severely inhibiting the induction by Staphylococcus aureus enterotoxin B of mRNA of three cytokine genes expressed in Th1 cells, those for IFN-gamma, IL-2, and tumor necrosis factor-beta . Yet, cell viability was not affected by linomide . The extent of inhibition is dose-dependent on linomide . Linomide also blocked induction of IL-2 and IFN-gamma mRNA by phytohemagglutinin . The inhibitory effect is expressed immediately but can be enhanced significantly by a prolonged exposure of PBMC to linomide, reaching 10-fold . These results support the concept that linomide antagonizes the activation of Th1 cells during a cellular immune response.

Br J Dermatol, 1996 Oct, 135(4), 528 - 32
Antimicrobial effects of phototherapy and photochemotherapy in vivo and in vitro; Yoshimura M et al.; We investigated the antimicrobial effects of phototherapy and photochemotherapy in vivo and in vitro . First, Staphylococcus aureus samples were obtained using stamp agar medium from inflammatory lesions of 29 adult patients with atopic dermatitis before and after a single photochemotherapy . Therapy was oral PUVA (30 mg 8-methoxypsoralen, 8MOP plus 5J/cm2 UVA), topical PUVA (0.3% 8MOP plus 200 mJ/cm2 UVA) or UVB (80 mJ/cm2) irradiation . The number of S . aureus on the lesions was significantly reduced, even after a single treatment with all therapies . Reductions (mean +/- SD) were 69.3 +/- 26.9%, 76.3 +/- 31.3% and 83.8 +/- 18.5%, respectively . Secondly, we investigated the effect of PUVA (0.001% 8MOP plus 10, 20, 30, 40, or 50 mJ/cm2 UVA) and UVB (10, 30, 50, or 100 mJ/cm2) irradiation on the proliferation of S . aureus in vitro . PUVA and UVB treatment markedly inhibited the proliferation in a dose-dependent manner . These results seem to indicate the possibility that the antimicrobial effect of UV radiation contributes to successful photochemotherapy in patients with atopic dermatitis.

Adv Ren Replace Ther, 1996 Oct, 3(4), 302 - 8
Staphylococcus aureus vaccination for dialysis patients--an update; Fattom AI et al.; Staphylococcus aureus infections are a major cause in both hemodialysis and peritoneal dialysis patients . The availability of a safe and effective protective vaccine would be of great benefit to these patients, but attempts at using vaccines consisting of inactivated whole cells have been unsuccessful . This article discusses an alternate approach to S . aureus vaccine design using a capsular polysaccharide conjugate and preliminary results in hemodialysis and peritoneal patients.

J Hosp Infect, 1996 Oct, 34(2), 151 - 60
Epidemiology of methicillin-resistant Staphylococcus aureus in a Warsaw hospital; Mlynarczyk G et al.; Methicillin-resistant Staphylococcus aureus (MRSA) isolates were collected during two eight-month periods in 1991 and 1994, respectively . In order to study the epidemiology, all 74 strains were characterized by phage-typing, antibiotic resistance patterns and DNA-restriction map after cleavage with SmaI enzyme, and pulsed-filed gel electrophoresis (PFGE) . These investigations confirmed that MRSA in the hospital, 1991 and 1994, was not due to the spread of one or two clones, but by the simultaneous occurrence of a few well characterized strains and sporadic, occurring strains of different phage-types . Some of these might have developed from the more commonly occurring strains . Isolates from 1994 were more resistant to antibiotics in vitro, than the 1991 isolates . The typing results also indicated that whilst most of the MRSA strains in 1994 were different compared with those of 1991, some of the strains might have been present in both years . The PFGE-typing was more discriminatory and gave a higher typability than the phage-typing, especially among the multiply resistant isolates of MRSA from 1994 . Among the less resistant strains the phage-typability was high and with only few exceptions, there was a good correlation between PFGE-type and phage-type.

J Hosp Infect, 1996 Oct, 34(2), 145 - 9
Survival of methicillin-resistant Staphylococcus aureus (MRSA) on naturally contaminated dry mops; Oie S et al.; The floors of single rooms being used by inpatients colonized by methicillin-resistant Staphylococcus aureus (MRSA) were cleaned using disposable dust-attracting dry mops . Each mop was divided into 12 sections and MRSA quantified serially . This experiment was repeated a total of 21 times for four patients . The MRSA survival rate on the dry mops compared with a control was 59.0-125% after seven days, 26.3-41.6% after 14 days, 0.1-16.2% after 28 days, 0-0.1% after 56 days and 0% after 84 days . MRSA disseminated by patients over the environment can survive for several weeks on dry mops.

Pediatr Pulmonol, 1996 Oct, 22(4), 236 - 47
Acute bronchiolitis in tropical Africa: a hospital-based perspective in Ibadan, Nigeria; Johnson AW et al.; In a 30-month prospective study of severe acute lower respiratory infections in hospitalized pre-school Nigerian children, acute bronchiolitis was diagnosed in 67 cases; 19 (28.4%) and 2 (3.0%) of these had concomitant pneumonia or croup, respectively . The peak prevalence was in the wet (rainy) season (May-October) . The male/female (M:F) ratio in infants < or = 6 months was 2.9:1, differing significantly from the 1.1:1 in older subjects (P = 0.04) . None of the subjects had severe malnutrition . Neither a high fever (> or = 39 degrees C), nor tachypnea on admission was significantly correlated with co-existing pneumonia . Of the 29 subjects in whom it was possible to explore viral immunofluorescence studies and/or serodiagnosis, we identified 26 viral identifications in 18 (62.1%) cases; 6 (20.7%) had > or = 2 viruses . Respiratory syncytial virus was identified in 11 (38.0%) of the 29 cases, and parainfluenza virus (PIV) types 1, 2, and 3 in 10 (34.5%) . PIV type 3 accounted for 7 cases, including 3 with bacteremia . Bacterial isolates were made in 9 (21.4%) of 42 blood cultures and in the only lung aspirate; Staphylococcus epidermidis and Staphylococcus aureus accounted for 4 and 3 cases, respectively . Although bacteremia was 2.9 times more common in cases with co-existing pneumonia or croup, the respective frequency of virus-positive cases and that of bacteremia was not significantly different between cases with bronchiolitis alone and those with associated pneumonia or croup . No deaths were recorded, but subjects aged > 6 months had a significantly shorter hospital stay than those < 6 months old (P = 0.02) . Despite the limited sample size, our findings reflect the etiological importance of the paramyxoviruses and the seasonal pattern of bronchiolitis in tropical Africa.

Infect Control Hosp Epidemiol, 1996 Oct, 17(10), 654 - 9
Quantitative antibiogram as a typing method for the prospective epidemiological surveillance and control of MRSA: comparison with molecular typing; Blanc DS et al.; OBJECTIVE: Evaluation of the quantitative antibiogram as an epidemiological tool for the prospective typing of methicillin-resistant Staphylococcus aureus (MRSA), and comparison with ribotyping . METHODS: The method is based on the multivariate analysis of inhibition zone diameters of antibiotics in disk diffusion tests . Five antibiotics were used (erythromycin, clindamycin, cotrimoxazole, gentamicin, and ciprofloxacin) . Ribotyping was performed using seven restriction enzymes (EcoRV, HindIII, KpnI, PstI, EcoRI, SfuI, and BamHI) . SETTING: 1,000-bed tertiary university medical center . RESULTS: During a 1-year period, 31 patients were found to be infected or colonized with MRSA . Cluster analysis of antibiogram data showed nine distinct antibiotypes . Four antibiotypes were isolated from multiple patients (2, 4, 7, and 13, respectively) . Five additional antibiotypes were isolated from the remaining five patients . When analyzed with respect to the epidemiological data, the method was found to be equivalent to ribotyping . Among 206 staff members who were screened, six were carriers of MRSA . Both typing methods identified concordant of MRSA types in staff members and in the patients under their care . CONCLUSIONS: The quantitative antibiogram was found to be equivalent to ribotyping as an epidemiological tool for typing of MRSA in our setting . Thus, this simple, rapid, and readily available method appears to be suitable for the prospective surveillance and control of MRSA for hospitals that do not have molecular typing facilities and in which MRSA isolates are not uniformly resistant or susceptible to the antibiotics tested.

Infect Control Hosp Epidemiol, 1996 Oct, 17(10), 649 - 53
Colonization by Staphylococcus aureus resistant to methicillin and ciprofloxacin during 20 months' surveillance in a private skilled nursing facility; Lee YL et al.; OBJECTIVE: To evaluate endemic colonization with Staphylococcus aureus resistant to methicillin, ciprofloxacin, or both among patients of a private skilled nursing facility, with regard to colonization rate and site, and relation to infection and prior antibiotic use . DESIGN: Prospective quarterly culture surveillance of nares and rectal specimens over 20 months' observation . RESULTS: The mean prevalence was 3.8% in new admissions and 5.4% for in-house patients; cumulatively, 7.5% of the patients were colonized during the study period . The colonization rate remained stable during the study period . Screening of rectal, as well as nares, specimens detected substantially more colonized patients than would have been detected by nasal cultures alone . Five to seven percent of the colonized patients developed later infection with methicillin-ciprofloxacin-resistant S aureus . Colonized patients did not differ significantly from the noncolonized group in prior use of quinolones, but the colonized group was exposed significantly more frequently to other antibiotics than the noncolonized group . Eighty-three percent of methicillin-resistant S aureus (MRSA) isolated from infections and 89% from colonization were also ciprofloxacin resistant . CONCLUSION: Although all infecting and most colonizing isolates of MRSA were resistant to quinolones, the overall rate of colonization remained low and stable despite the continued use of quinolones . The findings suggest that good infection control practice has prevented broader spread of such strains in this facility.

Can J Microbiol, 1996 Oct, 42(10), 1024 - 31
Staphylococcus aureus strains differ in their in vitro responsiveness to human urokinase: evidence that methicillin-resistant strains are predominately nonresponsive to the growth-enhancing effects of urokinase; Hart DA et al.; Clinical isolates of Staphylococcus aureus were found to exhibit strain-specific heterogeneity to the growth-enhancing effects of human urokinase (UK), a proteinase with plasminogen activator activity . Nine out of fourteen (64%) methicillin-sensitive strains of S . aureus were responsive to UK in "in vitro" cultures . In contrast, 3/29 (10%) methicillin-resistant strains were responsive to the proteinase . When only strains isolated from western Canada were considered, 6/11 methicillin-sensitive strains and 1/26 methicillin-resistant strains were responsive to UK . The single western Canadian methicillin-resistant strain (strain 456) responsive to UK was one of two isolated from the same patient, indicating that the two strains were phenotypically different . Strain 456, resistant to 32 micrograms methicillin/mL, was responsive to as little as 50 U UK/mL and enhancement of growth was evident by 9 h of incubation at 37 degrees C . This growth enhancement was specific to UK and not duplicated by equivalent concentrations of other proteins (bovine serum albumin, trypsin, plasminogen) . The results presented indicate differences in the frequency of the UK-responsive phenotype between methicillin-sensitive and -resistant S . aureus . These findings indicate that the UK phenotype of S . aureus may have utility in both phenotyping clinical isolates, as well as providing insights into the regulation of growth in this clinically important organism.

Biotechnol Appl Biochem, 1996 Oct, 24 ( Pt 2), 155 - 9
Expression and purification of recombinant toxicshock-syndrome toxin I; Wahlsten JL et al.; Toxic-shock-syndrome toxin I (TSSTI), an exotoxin produced by certain strains of Staphylococcus aureus, has been closely associated with the pathogenesis of toxic shock syndrome . Outside the context of its staphylococcal host, TSSTI may offer therapeutic uses . We report here a strategy for high-level expression and simplified purification of TSSTI . We have subcloned the coding region for TSSTI into a vector containing an inducible T7 promoter sequence and expressed the protein in an Escherichia coli host strain . The recombinant TSSTI protein contained ten sequential histidine residues (Histag) at its N-terminus, which enabled its efficient purification using nickel-agarose-affinity resin . Histag-TSSTI (H-TSSTI) was further purified to homogeneity using a size-exclusion column . By this system, 80 mg of highly purified H-TSSTI can be consistently obtained per litre of culture in under 3 days . H-TSSTI retained biological activity and was unaffected by the presence of the Histag, as measured in lymphocyte proliferation assays.

Arch Phys Med Rehabil, 1996 Oct, 77(10), 1014 - 8
Clinical use of percutaneous intramuscular electrodes for functional electrical stimulation; Shimada Y et al.; OBJECTIVE: To evaluate the clinical use of the percutaneous intramuscular electrode in functional electrical stimulation (FES) . DESIGN: Randomized and controlled study . SETTING: A referral center and institutional practice providing outpatient care . PATIENTS: Seventeen patients (12 men, 5 women) who had implanted percutaneous intramuscular electrodes for more than 1 year were examined . The average follow-up time after implantation of electrodes was 2.2 years (range, 1yr to 4yr 10mo) . Overall, there were 327 electrodes (83 upper extremities and 244 lower extremities) . INTERVENTION: The indwelling electrode was composed of helically coiled Teflon-coated rope stranded from 19 hard drawn wires of SUS 316L stainless steel (SES 114) . MAIN OUTCOME MEASURES: The rates of breakage, movement, and infection, and the number of electrodes that needed reimplantation were evaluated . RESULTS: Only one electrode broke (0.3%) in the iliopsoas muscle at 12 weeks after implantation . Eight electrodes (2.4%) were removed because of loss of sufficient contraction force caused by movement of the electrodes . Movements occurred at 9 weeks in 6 electrodes and at 5 months in two . The failure rate of electrodes in the lower extremities was 3.7% . No failures occurred in the upper extremities . Ten electrodes (3.1%) required reimplantation . Although ten superficial infections (3.1%) were seen around the site of electrode insertion, no removals of electrode were needed . All electrodes in one patient were removed, however, because of generalized methicillin-resistant Staphylococcus aureus infection complicated with renal disease . Electrodes were reimplanted after improvement of the infection . CONCLUSIONS: The ultrafine percutaneous intramuscular electrode was considered practical for long-term FES use.

J Med Microbiol, 1996 Oct, 45(4), 294 - 301
Persistence of Staphylococcus aureus strains among cystic fibrosis patients over extended periods of time; Branger C et al.; Pulsed-field gel electrophoresis (PFGE) of SmaI macrorestriction fragments of chromosomal DNA was used to confirm the persistence of methicillin-sensitive Staphylococcus aureus isolates in the sputum of 25 cystic fibrosis patients in five French hospitals . Three-to-eight consecutive isolates, with the same esterase electrophoretic type isolated from each patient over a period of 12-28 months, were analysed . Consecutive isolates with indistinguishable PFGE profiles were found in 12 patients (48%) and consecutive isolates with similar PFGE profiles showing minor differences of one-to-four fragments (similarity coefficient >/=84%) were found in 11 patients . Consecutive isolates with different PFGE profiles were obtained from only two patients, but the profiles found in each patient were more closely related to each other than to other profiles . The results were in agreement with esterase electrophoretic typing for 23 patients, and we considered that those patients were infected with a single persistent strain . For any given patient, variations in antibiotypes and phage types of consecutive isolates were not associated with major genotypic variations . PFGE is useful in confirming the persistence of S . aureus strains in cystic fibrosis patients over long periods.

Scand J Immunol, 1996 Oct, 44(4), 361 - 8
Increasing cytotoxic activity and production of reactive oxygen and nitrogen intermediates by peritoneal macrophages during the development of multiple organ dysfunction syndrome in mice; Jansen MJ et al.; A major problem in the intensive care unit nowadays is the development of multiple organ dysfunction syndrome (MODS), a cumulative sequence of progressive deterioration of organ functions . While the pathogenic pathways of MODS remain to be elucidated, it is assumed that cells of the host defence system, especially the macrophages, are altered in their function . During the development of MODS it is assumed that macrophages are overactivated and that an exaggerated inflammatory response may contribute to its pathogenesis . In order to gain insight into the alterations of the functional status of the macrophage during the development of MODS, a series of macrophage functions was measured in the subsequent phases of zymosan induced generalized inflammation in mice . Male C57BL/6 mice received a single dose of zymosan intraperitoneally and groups of animals were killed after 2, 5, 8, and 12 days . Peritoneal macrophages were collected for in vitro assessment of the ADCC, the production of superoxide (O2-) and nitric oxide (NO), and complement mediated phagocytosis and intracellular killing of Staphylococcus aureus . A single intraperitoneal injection with zymosan resulted in a three-phase illness . During the third phase the animals developed MODS-like symptoms . Peritoneal cells from control animals produced very low to non-detectable amounts of O2- and NO, and the cytotoxic activity was also low . During the development of MODS, from day 7 onwards, the ability to produce O2- and NO2- became strongly elevated, as did the cytotoxic activity . These findings are in parallel with the development of MODS whereas the phagocytic and killing capacity remained essentially unaltered . The changes found could be detrimental for the organism, thus possibly contributing to the onset and development of MODS.

J Infect Dis, 1996 Oct, 174(4), 800 - 5
Defective polymorphonuclear leukocyte functions in children receiving chemotherapy for cancer are partially restored by recombinant human granulocyte colony-stimulating factor in vitro; Lejeune M et al.; Granulocyte colony-stimulating factor (G-CSF) has important direct and priming effects on different functions of normal mature polymorphonuclear leukocytes (PMNL) . Previous study has shown an alteration in respiratory burst and bactericidal activities of PMNL harvested from children with cancer treated with chemotherapy . The present study evaluates the possibility that recombinant human (rh) G-CSF could correct these defective functions in vitro . Free radical formation in defective PMNL was enhanced by rhG-CSF to a level similar to that found in normal PMNL primed by rhG-CSF . The defective bactericidal activity against Escherichia coli and Staphylococcus aureus was also corrected . This bactericidal activity was not different from that observed in normal PMNL primed by rhG-CSF . In conclusion, correction of the altered free radical-formation pathway by rhG-CSF in these cells contributed to the restoration of normal bactericidal activity against both gram-positive and gram-negative microorganisms.

FEMS Microbiol Lett, 1996 Oct 1, 143(2-3), 203 - 10
Localization of prophages of serological group B and F on restriction fragments defined in the restriction map of Staphylococcus aureus NCTC 8325; Borecka P et al.; Several Staphylococcus aureus strains were lysogenized by the phages of serological group B (phages phi 53, phi 85) as well as by some of serological group F (phages phi 77, phi 84) and macrorestriction fragment patterns of genomic DNA were estimated in the lysogenized, non-lysogenic and delysogenized (cured of prophages) strains . It was shown that the integration of phage DNA into chromosome of S . aureus leads to specific changes in restriction fragment pattern in all the lysogenized strains . These changes correlate well with the SmaI restriction map of S . aureus NCTC 8325 since they concern the restriction fragments defined in this map . Phages phi 53 and phi 85 integrate into SmaI fragment B . On the other hand, phages phi 77 and phi 84 integrate into SmaI fragment E of the S . aureus restriction map . The prophages of strain NCTC 8511 have their integration sites, as follows: the phage designated by us phi M integrates in fragment A, whereas the integration site for phage phi J lies in fragment E . Phage phi M was estimated to be genetically related to phages of serological group A and phage phi J to those of serological group F . Evidence was given that lysogenization of S . aureus strains by at least four prophages does not cast any doubt upon the estimation of their genetic relatedness based on their similarity in restriction pattern.

FEMS Microbiol Lett, 1996 Oct 1, 143(2-3), 195 - 201
Detection of the response regulator AgrA in the cytosolic fraction of Staphylococcus aureus by monoclonal antibodies; Morfeldt E et al.; The expression of many virulence genes in Staphylococcus aureus is controlled by a regulatory RNA molecule, RNAIII, which is encoded by the agr locus . Transcription RNAIII requires the activity of the agrA, B, C and D genes, which code for components of a quorum sensing signal transduction system . In this report we describe the overexpression and purification of the response regulator, AgrA . Monoclonal antibodies were produced and used to detect AgrA in the cytosolic fraction of S . aureus cells . Purified AgrA did not bind to the RNAIII promoter region in a DNA mobility shift experiment . This confirms previous results obtained with protein extracts from agr+ and agr- cells.

J Bacteriol, 1996 Oct, 178(19), 5810 - 2
Identification of LytSR-regulated genes from Staphylococcus aureus; Brunskill EW et al.; In this report, the characterization of a Staphylococcus aureus operon containing two LytSR-regulated genes, lrgA and lrgB, is described . Sequence and mutagenesis studies of these genes suggest that lrgA encodes a murein hydrolase exporter similar to bacteriophage holin proteins while lrgB may encode a protein having murein hydrolase activity.

J Invest Dermatol, 1996 Oct, 107(4), 603 - 9
Staphylococcal toxins and protein A differentially induce cytotoxicity and release of tumor necrosis factor-alpha from human keratinocytes; Ezepchuk YV et al.; It has been proposed that toxins and other bacterial protein products of Staphylococcus aureus can act as triggers or persistence factors in several inflammatory skin diseases . In this study, we examined the S . aureus isolates from the skin of patients with atopic dermatitis and psoriasis . We found that the bacterial isolates from these patients exhibited either characteristic superantigenic toxins or thermolabile toxins believed to be staphylococcal alpha-toxin . All of these staphylococcal strains also secreted extracellular staphylococcal protein A . We found significant differences in the action of these toxins on human keratinocytes and keratinocyte cell lines . The superantigenic toxins toxic shock syndrome toxin-1, staphylococcal enterotoxins A and B, and exfoliative toxin-A, as well as staphylococcal protein A, did not induce significant cytotoxic damage in the keratinocyte cell line HaCaT, whereas the staphylococcal alpha-toxin produced profound cytotoxicity . Keratinocyte cytotoxicity induced by staphylococcal alpha-toxin was time and concentration dependent and demonstrated the morphologic and functional characteristics of necrosis, not apoptosis . Addition of alpha-toxin to keratinocytes simultaneously induced cell lysis and tumor necrosis factor-alpha release into the medium within 30 min; apparently, it was constitutive tumor necrosis factor-alpha . On the other hand, superantigenic toxins and, in particular, protein A showed stimulation of tumor necrosis factor-alpha secretion in keratinocytes and release of this cytokine after 6-12 h of incubation . Thus, staphylococcal protein A, alpha-toxin, and superantigenic toxins found in S . aureus isolates from patients with psoriasis and atopic dermatitis can produce direct pro-inflammatory effects on keratinocytes through the release of tumor necrosis factor-alpha . We propose that these effects may be relevant to the induction and persistence of lesions in these two diseases.

JAMA, 1996 Sep 25, 276(12), 972 - 7
Infection and allergy incidence in ambulatory surgery patients using white petrolatum vs bacitracin ointment . A randomized controlled trial; Smack DP et al.; OBJECTIVE: To assess the effect of white petrolatum vs bacitracin ointment on wound infection incidence, allergic contact dermatitis incidence, and healing characteristics . DESIGN: Randomized, double-blind, prospective trial comparing white petrolatum with bacitracin ointment in postprocedure wound care . SETTING: A general outpatient dermatology clinic and a tertiary referral advanced surgical procedure clinic at Walter Reed Army Medical Center, Washington, DC . PATIENTS: A total of 922 patients who had dermatologic surgery with a total of 1249 wounds . MAIN OUTCOME MEASURES: The incidence of infection and allergic contact dermatitis during a follow-up period of 4 weeks . Healing characteristics were secondary outcomes . RESULTS: Of the 922 patients enrolled, 440 in the white petrolatum group and 444 in the bacitracin group were evaluable for clinical response . The 2 treatment groups had comparable baseline characteristics . Thirteen patients developed postprocedure infection (1.5%), 9 (2.0%) in the white petrolatum group vs 4 (0.9%) in the bacitracin group (95% confidence interval for difference, -0.4% to 2.7%; P=.37) . Eight infections (1.8%) in the white petrolatum group were due to Staphylococcus aureus vs none in the bacitracin group (P=.004) . No patient in the group using white petrolatum developed allergic contact dermatitis vs 4 patients (0.9%) in the group using bacitracin (P=.12) . Additionally, there were no clinically significant differences in healing between the treatment groups on day 1 (P=.98), day 7 (P=.86), or day 28 (P=.28) after the procedure . CONCLUSIONS: White petrolatum is a safe, effective wound care ointment for ambulatory surgery . In comparison with bacitracin, white petrolatum possesses an equally low infection rate and minimal risk for induction of allergy.

Biochem Biophys Res Commun, 1996 Sep 24, 226(3), 730 - 4
Atomic force microscopy proposes a novel model for stem-loop structure that binds a heat shock protein in the Staphylococcus aureus HSP70 operon; Ohta T et al.; The Staphylococcus aureus HSP70 operon produces a polycistronic RNA in response to heat shock, and ORF37 is the first protein to be translated . The promoter of this operon contains a palindromic nucleotide sequence that may form a stem-loop structure . Structural analysis of the promoter regions by atomic force microscopy (AFM) revealed a quadruplet that consists of a pair of stem-loops . A novel "SL2S' (Stem-Loop-Loop-Stem) model was proposed for this structure . AFM also revealed the binding of ORF37 to the quadruplet, establishing a molecular mechanism for this heat shock gene expression; ORF37 acts as a regulator by binding to the SL2S structure in the promoter.

Biochemistry, 1996 Sep 24, 35(38), 12251 - 8
Structure and kinetics of the beta-lactamase mutants S70A and K73H from Staphylococcus aureus PC1; Chen CC et al.; Two mutant beta-lactamases from Staphylococcus aureus PC1 which probe key catalytic residues have been produced by site-directed mutagenesis . In the S70A enzyme, the nucleophilic group that attacks the beta-lactam carbonyl carbon atom was eliminated . Consequently, the kcat values for hydrolysis of benzylpenicillin and nitrocefin have been reduced by 10(4)-10(5) compared with the wild-type enzyme . The crystal structure of S70A beta-lactamase has been determined at 2.1 A resolution . With the exception of the mutation site, the structure is identical to that of the native enzyme . The residual activity is attributed either to mistranslation that leads to production of wild-type enzyme and/or to remaining features of the active site that stabilize the tetrahedral transition state . Soaking of the crystals with ampicillin or clavulanate, followed by flash-freezing, has been carried out and the structures examined at 2.0 A resolution . For both experiments, the difference electron density maps revealed buildup of density in the active site that presumably corresponds to beta-lactam binding . However, neither electron density is sufficiently clear for defining the atomic details of the bound compounds . The K73H beta-lactamase has been prepared to test the possible role of Lys73 in proton transfer . It exhibits no detectable activity toward benzylpenicillin, and 10(5)-fold reduction of kcat for nitrocefin hydrolysis compared with the wild-type enzyme . No significant recovery of activity has been measured when the pH was varied between 5.0 and 8.0 . The crystal structure of K73H beta-lactamase has been determined at 1.9 A resolution . While the overall structure is similar to that of the native enzyme, the electrostatic interactions between His73 and neighboring residues indicate that the imidazole ring is positively charged . In addition, the hydroxyl group of Ser70 adopts a position that is incompatible with nucleophilic attack on substrates . A crystal soaked with ampicillin was flash-frozen, and diffraction data were collected at 2.1 A resolution . The electron density map showed no indication of substrate binding.

EMBO J, 1996 Sep 16, 15(18), 4789 - 97
Target cell specificity of a bacteriocin molecule: a C-terminal signal directs lysostaphin to the cell wall of Staphylococcus aureus; Baba T et al.; Microbial organisms secrete antibiotics that cause the selective destruction of specific target cells . Although the mode of action is known for many antibiotics, the mechanisms by which these molecules are directed specifically to their target cells hitherto have not been described . Staphylococcus simulans secretes lysostaphin, a bacteriolytic enzyme that cleaves staphylococcal peptidoglycans in general but that is directed specifically to Staphylococcus aureus target cells . The sequence element sufficient for the binding of the bacteriocin as well as of hybrid indicator proteins to the cell wall of S.aureus consisted of 92 C-terminal lysostaphin residues . Targeting to the cell wall of S.aureus occurred either when the hybrid indicator molecules were added externally to the bacteria or when they were synthesized and exported from their cytoplasm by an N-terminal leader peptide . A lysostaphin molecule lacking the C-terminal targeting signal was enzymatically active but had lost its ability to distinguish between S.aureus and S.simulans cells, indicating that this domain functions to confer target cell specificity to the bacteriolytic molecule.

Cell Immunol, 1996 Sep 15, 172(2), 205 - 16
Induction of inhibitory activity for B cell differentiation in human CD8 T cells with pokeweed mitogen, dimaprit, and cAMP upregulating agents: countersuppressive effect of platelet factor 4; Crisi GM et al.; As shown previously, native or recombinant (r) human platelet factor 4 (PF4) alleviates the suppression induced by Con A or dimaprit, a histamine type 2 receptor (H2-R) agonist, in a murine system . The effect of rPF4 on human peripheral blood cells has now been studied, using as a model pokeweed mitogen (PWM)-induced, T-cell-mediated suppression of Ig-secreting cell (ISC) formation by Staphylococcus aureus and rIL-2 activated B cells . PWM, but not phytohemagglutinin (PHA), induced inhibitory activity in mitomycin-treated CD8+ T cells, but not unfractionated or CD4+ T cells, for both ISC formation and B cell proliferation . rPF4 and its C-terminal tridecapeptide alleviated the suppressive effect of PWM-activated CD8+ T cells on ISC production but not on proliferation . Heparin did not prevent this immunoregulatory activity of PF4 . Neutralizing antibody to TGF-beta, but not to IFN-gamma or TNF-alpha, alleviated the suppression of ISC formation in some of the experiments . The H2-R appeared to play a part in inducing suppression, because the H2-R antagonist, cimetidine, prevented the PWM-induced suppression of ISC production . Furthermore, dimaprit induced suppression of ISC formation when added instead of PWM at the start of culture . Incubation of CD8+ T cells with dimaprit for only 3 hr prior to coculture with S . aureus + IL-2 activated B cells decreased the ISC response . This suppression was also alleviated by addition of rPF4 to the coculture . Similar to dimaprit, known cAMP upregulating agents, such as forskolin, dibutyryl cAMP, and cAMP analog, all induced this immunoregulatory activity in T cells . Moreover, the effect of dimaprit was prevented by the specific protein kinase A inhibitor, HA1004, suggesting strongly that upregulation of cAMP played a role in the H2-R-mediated effect . Cell contact appeared to be necessary, since supernatants from dimaprit or PWM activated T cells failed to suppress ISC production . We suggest that the known ability of PF4 to prevent TGF-beta-mediated effects on endothelial and other target cells may be involved in the alleviating effect of PF4 on the cell-contact-dependent CD8+ T-cell-mediated B cell suppression.

Hosp Pract (Off Ed), 1996 Sep 15, 31(9), 133 - 7, 142-4, 150
Catheter-associated Staphylococcus aureus bacteremia; Gold HS et al.; The majority of cases of Staphylococcus aureus bacteremia are hospital-acquired, and most are associated with infected intravenous catheters . Preventive measures, early detection of infections, and strategies for effective treatment have become matters of increasing urgency.

J Immunol, 1996 Sep 15, 157(6), 2555 - 63
L-selectin (CD62L) blockade does not impair peritoneal neutrophil emigration or subcutaneous host defense to bacteria in rabbits; Sharar SR et al.; Neutrophil (PMN) recruitment into systemic inflammatory sites in vivo is thought to be initiated by selectin-mediated endothelial adherence . We explored the role of L-selectin (CD62L) in leukocyte emigration following instillation of bacteria into the peritoneum or s.c . skin in rabbits . Pretreatment with blocking mAb against L-selectin (LAM1.3) reduced peritoneal PMN emigration 4 h after i.p . inoculation with 10(10) CFU of Escherichia coli by only 17% compared with animals receiving a nonblocking L-selectin mAb (LAM1.14) . Peritoneal PMNs from saline-treated rabbits demonstrated a complete absence of L-selectin, whereas those from LAM1.3-treated animals retained 43% of their baseline L-selectin expression . This suggests that L-selectin shedding is not a requisite event for PMN emigration under these conditions . In rabbits given s.c . inoculations with either Staphylococcus aureus or E coli, pretreatment with mAb LAM1.3 did not significantly impair PMN emigration at 24 h, nor increase the incidence, size, or associated mortality of resulting abscesses at 7 days compared with animals receiving nonblocking mAb LAM1.14 . We conclude that: 1) mAb blockade of L-selectin in vivo only modestly affects acute, E . coli-induced peritoneal PMN emigration; and 2) L-selectin blockade does not increase infectious sequelae associated with s.c . bacterial inoculation . These findings of only mildly reduced PMN emigration into the peritoneum and no alteration in s.c . host defense differ from those reported with L-selectin blockade under other, nonbacterial inflammatory conditions, and suggest that redundant selectin-mediated mechanisms (P- and E-selectin) are sufficient for normal PMN emigration in response to bacterial stimulation.

J Immunol, 1996 Sep 15, 157(6), 2514 - 20
Bacteria in the bloodstream are trapped in the liver and killed by immigrating neutrophils; Gregory SH et al.; The critical role of the liver in the resolution of systemic bacterial infections is well documented . In the case of Listeria monocytogenes, approximately 60% of bacteria inoculated i.v . into mice are recovered in the liver at 10 min after infection . Here we report that the Listeria recovered at 10 min were distributed equally among the hepatocyte and nonparenchymal liver cell populations . The majority (>/= 75%) of these organisms were bound extracellularly as judged by their sensitivity to gentamicin . In contrast, >/= 93% of Listeria recovered in the liver at 6 h were located within hepatocytes . The listerial burden of the liver decreased 0.5 to 1.0 log, between 10 min and 6 h after infection . This decrease correlated with a sevenfold increase in the percentage of neutrophils that constituted the nonparenchymal cell population . Mice rendered neutrophil deficient by pretreatment with anti-granulocyte (RB6-8C5) mAb exhibited a significant increase (>300%) rather than a decrease in liver Listeria and a marked increase in hepatocyte damage . Similarly, neutrophil-deficient mice exhibited a reduced capacity to eliminate Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus that were cleared by the liver and bound extracellularly to hepatocytes and nonparenchymal cells . These findings document the crucial role of immigrating neutrophils in nonspecific host defenses to systemic bacterial infections expressed within the liver.

J Am Vet Med Assoc, 1996 Sep 15, 209(6), 1143 - 6
Evaluation of a coagulase-negative variant of Staphylococcus aureus as a cause of intramammary infections in a herd of dairy cattle; Fox LK et al.; A coagulase-negative variant of Staphylococcus aureus was identified in a herd of 250 lactating dairy cows . During testing of the entire herd, this strain of S aureus was isolated from aseptically collected milk samples of 25 cows . Cows with intramammary infections attributable to coagulase-negative S aureus had an increased somatic cell count in their milk, which was indicative of mastitis infection . Speciation of the Staphylococcus organisms was made, using a series of biochemical tests . A strain of a coagulase-positive S aureus also caused intramammary infections in the herd and shared identical biochemical characteristics with the coagulase-negative strain . Moreover, both strains could not be typed by the use of the International Set of Bovine Phages . Analysis of these findings indicated that a coagulase-negative variant of S aureus can cause intramammary infections in cattle, coagulase-negative variants of S aureus that cause mastitis can be more prevalent in herds than coagulase-positive variants, and clinicians should avoid misclassifying coagulase-negative S aureus as organisms that are clinically unimportant.

J Chromatogr A, 1996 Sep 13, 744(1-2), 177 - 85
Comparative peptide mapping of a hepatitis C viral recombinant protein by capillary electrophoresis and matrix-assisted laser desorption time-of-flight mass spectrometry; Winkler MA et al.; Capillary electrophoresis (CE) and matrix assisted laser desorption time-of-flight mass spectrometry (MALDI-TOF-MS) were investigated as alternatives to sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis for peptide mapping with Staphylococcus aureus protease (V8) of a hydrophobic recombinant hepatitis C virus antigen, HC-31, which required 0.1% SDS for solubility . Controls (V8 only) or HC-31 digests were extracted with chloroform-methanol-water (1:4:3) to remove SDS, which interferes with MALDI-TOF, and high salt content, which affects CE . In two different runs by CE, the elution times of each of 11 peptide peaks were very reproducible (R.S.D . < 0.016) . 25 fragments were resolved by MALDI-TOF-MS, including six smaller peptides (M(r) < 13 000) resulting from V8 autodigestion . MALDI-TOF-MS indicated that partial cleavages occurred, primarily at sites where there are paired glutamic and/or aspartic acid residues.

J Mol Biol, 1996 Sep 13, 262(1), 21 - 30
Surface display of proteins on bacteriophage lambda heads; Mikawa YG et al.; We have developed plasmid and phage vectors for the display of foreign proteins on the surface of bacteriophage lambda capsid by modifying the D gene which encodes the major head protein gpD . The vectors have multiple cloning sites, and permit colour selection and conditional chain termination for recombinants . Displayed proteins can be fused to either the N or C terminus of gpD by a peptide linker . The conditional chain termination scheme, via a host Escherichia coli suppressor activity, allows the fusion and assembly of homomultimeric proteins as well as control of the number of fusion proteins per phage particle . We have successfully displayed beta-lactamase, IgG-binding domains of the Staphylococcus aureus protein A, and beta-galactosidase by cloning the genes into the vector . The constructs express functionally active proteins fused to gpD that assemble into phage particles . These results suggest that gpD may be fused to many other peptides and proteins at their N or C terminus and the fusion products may be accessible on the surface of bacteriophage lambda particles.

Arch Intern Med, 1996 Sep 9, 156(16), 1857 - 60
Microbiology of acute purulent pericarditis . A 12-year experience in a military hospital; Brook I et al.; OBJECTIVE: To study the aerobic and anaerobic micro-biological and clinical characteristics in 15 cases of acute pericarditis treated over a 12-year period . DESIGN: Retrospective review of microbiological and clinical data . SETTING: Military hospital in Bethesda, Md . RESULTS: Aerobic or facultative bacteria alone were present in 7 specimens (47%), anaerobic bacteria alone in 6 specimens (40%), and mixed aerobic-anaerobic flora in 2 specimens (13%) . In total, there were 21 isolates: 10 aerobic or facultative bacteria and 11 anaerobic bacteria, an average of 1.4 per specimen . Anaerobic bacteria predominated in patients with pericarditis who also had mediastinitis that followed esophageal perforation and in patients whose pericarditis was associated with orofacial and dental infections . The predominant aerobic bacteria were Staphylococcus aureus (3 isolates) and Klebsiella pneumoniae (2 isolates), and the predominant anaerobic bacteria were Prevotella species (4 isolates), Peptostreptococcus species (3 isolates), and Propionibacterium acnes (2 isolates) . CONCLUSION: The findings in our study highlight the potential importance of anaerobic bacteria in acute pericarditis.

Biochim Biophys Acta, 1996 Sep 6, 1303(1), 63 - 73
Leukotriene B4 and platelet activating factor production in permeabilized human neutrophils: role of cytosolic PLA2 in LTB4 and PAF generation; Bauldry SA et al.; The specific type of phospholipase A2 (PLA2) involved in formation of leukotriene B4 (LTB4) and platelet activating factor (PAF) in inflammatory cells has been controversial . In a recent report we characterized activation of the 'cytosolic' form of PLA2 (cPLA2) in human neutrophils (PMN) permeabilized with Staphylococcus aureus alpha-toxin under conditions where the secretory form of PLA2 (sPLA2) was inactive . In the current study, generation of both LTB4 and PAF in porated PMN are demonstrated . PMN, prelabeled with {3H}arachidonic acid (3H-AA, to assess AA release and LTB4 production) or with 1-O-{9',10'-3H}hexadecyl-2-lyso-glycero-3-phosphocholine (3H-lyso-PAF, for determination of lyso-PAF and PAF formation), were permeabilized with alpha-toxin in a 'cytoplasmic' buffer supplemented with acetyl CoA . Maximum production of both PAF and LTB4 required addition of 500 nM Ca2+, G-protein activation induced with 10 microM GTP gamma S, and stimulation with the chemotactic peptide, N-formyl-Met-Leu-Phe (FMLP, 1 microM); LTB4 production was confirmed by radioimmunoassay . Removal of acetyl CoA from the system had little effect on LTB4 generation but blocked PAF production with a concomitant increase in lyso-PAF formation LTB4 and PAF production occurred in parallel over time and at differing ATP and Ca2+ concentrations . Further work demonstrated that: (i) maximum production of both inflammatory mediators required a hydrolyzable form of ATP; (ii) blocking phosphorylation with staurosporin inhibited production of both; (iii) the reducing agent, dithiotreitol, had little affect on LTB4 formation but slightly enhanced PAF generation . This study clearly shows that cPLA2 activation can provide precursors for both LTB4 and PAF, that maximum PAF and LTB4 formation occur under conditions that induced optimal cPLA2 activation, that a close coupling between LTB4 and PAF formation exists, and that, after substrate generation, no additional requirements are necessary for LTB4 and PAF generation in the permeabilized PMN system.

Biochim Biophys Acta, 1996 Sep 5, 1296(2), 228 - 34
C-terminal truncation of spinach chloroplast NAD(P)-dependent glyceraldehyde-3-phosphate dehydrogenase prevents inactivation and reaggregation; Scheibe R et al.; Chloroplast NAD(P)-dependent glyceraldehyde-3-phosphate dehydrogenase (NAD(P)-GAPDH; EC 1.2.1.13) consists of two types of subunits: GapA and GapB, which are rather similar, except that GapB carries an unique C-terminal sequence extension . Here, we report evidence that this sequence extension might be responsible for aggregation and dark inactivation of the enzyme in vivo . Recently, it had been demonstrated that upon limited proteolysis of the purified 600 kDa enzyme, using the Staphylococcus aureus V8 endoproteinase (Zapponi et al . (1993) Biol . Chem . Hoppe-Seyler 374, 395-402), the C-terminus of GapB can be removed, giving rise to the 150 kDa form . Based on these findings, we analyzed the changed catalytic properties of the enzyme after proteolysis and its ability to reaggregate . The time-course of proteolysis is paralleled by a strong increase in enzyme activity and the appearance of the tetrameric enzyme form, the increase of apparent activity preceding disaggregation . The proteolyzed enzyme is characterized by its increased affinity towards the substrate 1,3-bisphosphoglycerate and thus resembles the fully activated intact enzyme . In contrast to the effector-mediated activation of the intact enzyme, both proteolytic activation and the resulting disaggregation of the high-molecular-weight form cannot be reversed, even by incubation with NAD.

Biochemistry, 1996 Sep 3, 35(35), 11503 - 11
Acid-induced molten globule state of a fully active mutant of human interleukin-6; De Filippis V et al.; Interleukin-6 (IL-6), a four-helix bundle protein, is a multifunctional cytokine which plays an important role in the regulation of the immune system, hematopoiesis, and inflammatory response, as well as in the pathogenesis of multiple myeloma . We have previously shown that a single-disulfide variant of human IL-6, lacking 22 N-terminal amino acids and the disulfide bond connecting Cys-45 and Cys-51 in the 185-residue chain of the wild-type protein, fully retains the conformational, stability, and functional properties of the full-length human IL-6 {Breton et al . (1995) Eur . J . Biochem . 227, 573-581} . In this study, we have investigated the conformational and stability properties of mutant IL-6 at acidic pH (A-state) . Using far- and near-ultraviolet (UV) circular dichroism (CD), fluorescence emission, and second-derivative absorption spectroscopy, we have established that mutant IL-6 at pH 2.0 fully retains the helical secondary structure of the native protein at pH 7.5, while the tertiary interactions are much weaker . At variance from the native species, mutant IL-6 in the A-state binds 1-anilinonaphthalene-8-sulfonic acid (ANS), a property considered most typical of a protein in the molten globule state . The pH-induced conformational change from the native to the A-state, monitored either by near-UV CD or by ANS-binding measurements, shows a transition midpoint at pH approximately 4.5, thus indicating that the partial unfolding of the protein is mediated by the titration of glutamic and/or aspartic acid residues . At pH 2.0, the thermal denaturation of mutant IL-6 occurs as a broad process of low cooperativity with a transition at 50-60 degrees C, whereas at pH 7.5 the thermal unfolding is cooperative and characterized by a transition midpoint at 65 degrees C . Of interest, the unfolding of the A-state is not complete even up to approximately 85 degrees C . The urea-mediated unfolding profile of mutant IL-6, measured by far-UV CD, is essentially identical at both pH 7.5 and 2.0, with a midpoint of the cooperative unfolding transition at 5.5 +/- 0.1 M denaturant . Both thermal and urea denaturations of the A-state are complex and cannot fit to a two-state model for unfolding . The unusual stability of mutant IL-6 in acid is also reflected by the resistance to proteolysis at pH 3.6-4.0 by Staphylococcus aureus V8 protease or cathepsin D, an acid protease released by machrophages upon inflammatory stimulation . It is suggested that the molten globule state of IL-6 at acidic pH can play a role in the biological activity of this cytokine, which can exert its activity also at mildly acidic pH, as in inflammation sites.

Chin Med J (Engl), 1996 Sep, 109(9), 711 - 9
Polymorphonuclear leukocyte-mediated bone degradation and influence of blood mononuclear cells on the mouse calvarial model; Wang YH et al.; OBJECTIVE: To investigate the relationships between degradation of bone and activated blood polymorphonuclear leukocytes (PMNL) and mononuclear leukocytes (ML) as well as their soluble products in vitro . MATERIALS AND METHODS: A neonatal mouse calvarial bone model was used to assess the activity of degradation (by measuring the amount of 45Ca release) by normal human blood leukocytes, separated PMNL and ML following 24-hour incubation . The effects of conditioned culture medium obtained from Staphylococcus aureus-stimulated ML on PMNL-mediated calvarial bone loss were also studied . RESULTS: It was demonstrated that isolated human PMNL rapidly degraded bone in a dose and time dependent manner . The PMNL-mediated bone degradation was enhanced by conditioned medium obtained from Staphylococcus aureus-stimulated ML . CONCLUSION: These findings implicate PMNL as major contributors to early bone loss in infectious diseases such as acute haematogenous osteomyelitis.

Rev Med Chil, 1996 Sep, 124(9), 1142 - 6
{Prevalence of Staphylococcus aureus among food handlers from a metropolitan university in Chile}; Soto A et al.; BACKGROUND: An important agent of food intoxication is Staphylococcus aureus, that is able to produce enterotoxins . AIM: To detect Staphylococcus aureus contamination in cafeteria food handlers of a Chilean University . SUBJECTS AND METHODS: Nose, throat, hands and nail samples from 87 food handlers were obtained for microbiological examination . RESULTS: Fifty seven subjects (65.5%) were carriers of Staphylococcus aureus . Enterotoxigenic Staphylococcus aureus was found in 36 subjects (41%) . The most frequently found enterotoxin was type B (18 samples) followed by type D (12 samples) . Men bad a higher frequency of contamination than women (83 and 57% of positive samples respectively) . CONCLUSIONS: The frequency of Staphylococcus aureus contamination among food handlers is high and should prompt personal and environmental hygienic measures.

Southeast Asian J Trop Med Public Health, 1996 Sep, 27(3), 600 - 5
Neonatal septic arthritis; Halder D et al.; Neonatal septic arthritis has always been considered as separate from its counterpart in older children . The condition is uncommon but serious . Affected neonates usually survive, but with permanent skeletal deformities . Ten cases of neonatal septic arthritis were diagnosed between January 1989 and December 1993 in the neonatal intensive care units of two referral hospitals in the state of Kelantan, Malaysia . All except one neonate was born prematurely . The mean age of presentation was 15.6 days . Joint swelling (10/10), increased warmth (7/10) and erythema of the overlying skin (7/10) were the common presenting signs . Vague constitutional symptoms preceded the definitive signs of septic arthritis in all cases . The total white cell counts were raised with shift to the left . The knee (60%) was not commonly affected, followed by the hip (13%) and ankle (13%) . Three neonates had multiple joint involvement . Coexistence of arthritis with osteomyelitis was observed in seven neonates . The commonest organism isolated was methicillin resistant Staphylococcus aureus (9/10) . Needle aspiration was performed in nine neonates and one had incision with drainage . Follow up data was available for five neonates and two of these had skeletal morbidity . Early diagnosis by frequent examination of the joints, prompt treatment and control of nosocomial infection are important for management.

J La State Med Soc, 1996 Sep, 148(9), 399 - 402
Nosocomial central venous catheter-related infections in intensive care units; Tabak OF et al.; To examine the recent microbiology of catheter-related infections (CRIs) in the intensive care unit (ICU) setting and to determine the association between selected factors and mortality among ICU patients diagnosed with a CRI, a retrospective review of all ICU patients determined to have a CRI between January 1992 and December 1994 was undertaken . A total of 108 patients with 111 episodes of CRIs were identified . The most common isolate was coagulase negative staphylococcus (37.9%), followed by Staphylococcus aureus (20.9%) . Methicillin resistance was common in both CNS (93%), and S aureus (42%) isolates . Factors predictive for death in a multivariate analysis were as follows: male sex (relative risk (RR) 2.43, 95% confidence interval (CI) 1.0, 6.07), hypotension (RR 6.90, 95% CI 1.56, 12.2), American Society of Anesthesiologist physical status score greater than 3 (RR 4.36, 95% CI 1.56, 12.2), and underlying medical condition (RR 3.50, 95% CI 1.17, 10.5) . This study demonstrated the increasing proportion of CRIs due to methicillin-resistant organisms in the ICU . Functional status and degree of illness were the strongest predictors for survival in this population.

Zh Mikrobiol Epidemiol Immunobiol, 1996 Sep-Oct, (5), 84 - 6
{The causative agent of wound infection and sepsis in burn patients}; Pal'tsyn AA et al.; The content of antibodies to the autostrains of bacteria isolated from the wound and blood of burn patients was studied . Antibodies were found not to all species and strains isolated from the wound, but only to 1 or 2 of them . Usually Staphylococcus aureus and Pseudomonas were detected . The appearance or sharp rise of the titer of antibodies even to one of all strains contaminating the wound was observed in all examined burn patients, including those having septic complications, i.e . all these patients retained their capacity of antibody formation . The causative agent of wound infection and sepsis, determined by a high titer of antibodies to it, was seldom detected in the blood . This was due to the fact that bacteria were agglutinated by antibodies or retained in tissues on the level of the histo-hematic barrier . In cases of the development of septic endocarditis the inhibiting role of antibodies was not manifested, and the causative agent of this infection was often detected in the blood.

Pediatr Med Chir, 1996 Sep-Oct, 18(5), 511 - 3
{Sepsis related to a permanent central venous catheter in children with neoplastic disease: practical implications of a continuous surveillance of the etiology}; Castagnola E et al.; Indwelling central venous catheter-related bacteremias are an important complication in patients with cancer . In general they are due to Staphylococcus aureus and Candida, while bacteremias caused by Gram-negatives are less common and often related to infusate contaminans . We describe a survey of etiological surveillance of Broviac catheter-related infections at G . Gaslini Children's Hospital of Genoa, Italy . In the period 1989-1992 an increase of Broviac catheter-related bacteremias due to Gram-negatives was demonstrated as compared with previous years (1985-1988) . At home parental management was suspected as an important risk factor, since this complication was frequently due to infusate contaminants and no epidemic cluster or positive surveillance culture was observed in the Hospital . Therefore at home management was changed, especially regarding heparin storage . The subsequent, prospective follow-up from July 1993 to December 1995 showed a significant decrease in catheter-related bacteremias due to Gram-negatives (P = 0.003, chi-square test) . In conclusion, a strict control on at home catheter management procedures must be maintained in order to reduce the risk of indwelling central venous catheter-related infections in children with cancer.

Pediatr Pathol Lab Med, 1996 Sep-Oct, 16(5), 755 - 64
Perianal abscess and fistula in ano in infancy and childhood: a clinicopathological study; al-Salem AH et al.; This is a retrospective study of 78 children with perianal abscess and/or fistula in ano presenting during a 6 1/2-year period . Sixty-five were males and 13 females . Their ages at presentation ranged from 22 days to 18 years (median 1.7 year), and the majority of males were below 2 years of age . The 13 females all presented with perianal abscess, the majority of which grew Staphylococcus aureus (69.2%) . On follow-up, none of them developed fistula in ano . Twenty-two of the 65 males (33.8%) presented initially with fistula in ano . The remaining 43 presented with perianal abscess . Four of them were found to have fistula in ano at the time of incision and drainage and on follow-up, and 14 others developed fistula in ano . Of the 40 cases of fistula in ano, all were males; 25 were on the right side and 9 on the left side, 5 had bilateral fistula in ano, and 1 had two fistulas on the left side at 3 and 5 o'clock positions . Gut-derived organisms were isolated from 88.4% of the males with perianal abscess . There appears to be a causal relationship between perianal abscess and fistula in ano.

Prikl Biokhim Mikrobiol, 1996 Sep-Oct, 32(5), 519 - 23
{Isolation and physico-chemical characteristics of Staphylococcus hyaluronidase}; Turmanidze TS et al.; A scheme for purification of hyaluronidase from Staphylococcus aureus 0-15 that allows to produce a 550-fold-purified preparation with a high specific activity was developed . Hyaluronidase was found to consist of two molecular forms with different molecular weights . Staphylococcus hyaluronidase referred to as a complex preparation and its molecular forms have action optimum at pH 5.0-7.2 and at a temperature between 30 and 37 degrees C . The enzymes were highly specific to their substrate: they catalyzed the depolimerization of hyaluronic acid but did not split the other glycosaminoglycans.

Ceska Slov Farm, 1996 Sep, 45(5), 242 - 5
{Royleanones in the roots of Salvia officinalis L . of domestic provenance and their antimicrobial activity}; Masterova I et al.; The reported investigation of the constituents of the petroleum ether extract of the root of Salvia officinalis L . confirmed the presence of the following diterpene quinones: 12.hydroxy-8, 12-abietadiene-11, 14-dione (royleanone), 7 alpha, 12-dihydroxy-8.12-abistadiene-11-14-dione (horminone) and 7 alpha-acetoxy-12-hydroxy-8, 12-abietadiene-11,14-dione (7-O-acetylhorminone) . The compounds were identified on the basic of the interpretation of results of spectral analysis . Isolated royleanones show antimicrobial activity against gram-positive bacteria (Staphylococcus aureus) . A study of abietate diterpenoids in the root of Salvia officinalis L . of Slovak provenance has been performed for the first time.

Diagn Microbiol Infect Dis, 1996 Sep, 26(1), 13 - 5
Sternoclavicular joint septic arthritis with small-colony variant Staphylococcus aureus; Spearman P et al.; Small-colony variants of Staphylococcus aureus may cause invasive disease in adults that is prolonged and refractory to standard therapies . We present a case of sternoclavicular arthritis with small-colony variant S . aureus that occurred in an 11-year-old child and discuss the importance of identification of these variants in the clinical microbiology laboratory.

Rev Prat, 1996 Sep 1, 46(13), 1599 - 602
{Follicular staphylococcal infections}; Le Bozec P; Staphylococcal folliculitis are a common disability in early adult life . Some patients suffer only one attack, while others continue to develop recurrences over months . In such a case, nasal carriage of staphylococcus aureus should be sought in the patients and family members . The lesions may often respond to topical antiseptics . Systemic antibiotics should only be started when furuncles are complicated . Topical antibiotics, applied to the anterior nares of patients and household carriers, seems to control recurrent infection more effectively than systemic antibiotics alone . Even so, few patients will experience recurrent lesions despite good initial response to treatment.

ASAIO J, 1996 Sep-Oct, 42(5), M476 - 9
Bacterial adhesion on polyurethane surfaces conditioned with thrombus components; Baumgartner JN et al.; Thrombosis and infection are two major complications associated with cardiovascular devices such as ventricular assist devices, total artificial hearts, vascular grafts, and catheters . When blood contacts an artificial biomaterial, protein deposition occurs, as do activation of the blood coagulation cascade, platelet adhesion, activation, and aggregation, all of which lead to thrombus formation . An increased incidence of bacterial infection also has been seen clinically with indwelling biomaterial devices . Some evidence suggests a possible association between thrombosis and infection, in that adherent bacteria may provide a nidus for thrombus formation, or adherent thrombi composed of platelets and fibrin may form sheltered sites for bacterial adhesion . In the current study, the authors examined Staphylococcus aureus adhesion to sulfonated, aminated, and phosphonated polyurethane surfaces that had been pre-adsorbed with solutions of increasing complexity, in an effort to approach and simulate clot formation on the surface . These solutions included various combinations of fibrinogen, albumin, plasma, thrombin, and isolated platelets . Bacterial adhesion was observed in a radial flow chamber mounted on the motorized stage of a video microscopy system, with image processing software used to perform automated data collection and image analysis . Scanning electron microscopy also was used to visualize cross-linked fibrin and bacterial adhesion on these surfaces . Bacterial adhesion was found to be lowest on the phosphonated polyurethane . The presence of fibrin or isolated platelets significantly increased bacterial adhesion compared to surfaces pre-adsorbed with albumin.

Infection, 1996 Sep-Oct, 24(5), 372 - 4
Penetration of ampicillin and sulbactam into human epididymis and testis; Klotz T et al.; Urologic refertilization microsurgery such as vaso-vasostomy or vaso-epididymostomy benefits from perioperative antibiotic prophylaxis . The ability of ampicillin and sulbactam to penetrate sufficiently into mixed epididymis or testis tissue was investigated in nine patients (bodyweights ranged from 58 kg to 92 kg, mean 77.3 kg) undergoing orchiectomy for testicular cancer or advanced prostatic cancer . Each patient received a single infusion of 3 g ampicillin/sulbactam (ratio 2:1) preoperatively for antibiotic prophylaxis . The concentrations of both components were determined in serum and in epididymis/testis tissue samples taken 30 min to 65 min after infusion . Ampicillin was determined by bioassay and sulbactam was determined by gas chromatography/ mass spectrometry . Mean tissue concentrations of ampicillin were 38.5 +/- 15.9 mg/kg . Mean tissue concentrations of sulbactam at the same time were 19.8 +/- 5.2 mg/kg . Comparison of the tissue/serum ratios for both agents showed no significant difference . These values indicate that both compounds achieve high concentrations in the scrotal organs . The concentrations exceed the MIC (minimal inhibitory concentration) values of important bacterial pathogens such as Staphylococcus aureus involved in postoperative wound infections . The combination of ampicillin and sulbactam may be effective for perioperative prophylaxis in reconstructive scrotal urologic surgery.

Eur J Clin Microbiol Infect Dis, 1996 Sep, 15(9), 747 - 9
European multicentre evaluation of a commercial system for identification of methicillin-resistant Staphylococcus aureus; Zambardi G et al.; A commercial system for the rapid detection of methicillin-resistant Staphylococcus aureus, the BBL Crystal MRSA test (C-MRSA ID; Becton Dickinson, USA), was evaluated prospectively and compared with a polymerase chain reaction test for the presence of the mecA gene . Ten European centres tested a total of 676 isolates of Staphylococcus aureus from blood cultures . The system correctly identified 661 (97.8%) isolates within 4 h . All but three mecA gene-negative isolates (99.4% specificity) yielded a negative C-MRSA ID reaction, and 158 of 170 mecA gene-positive isolates were accurately detected (92.9% sensitivity) . After repeated testing of discrepant results, sensitivity and specificity increased to 99% and 100%, respectively.

Kansenshogaku Zasshi, 1996 Sep, 70(9), 915 - 22
{Bactericidal effect of acidic electrolyzed water--comparison of chemical acidic sodium hydrochloride (NaOCl) solution}; Iwasawa A et al.; Acidic electrolyzed water is made recently by various kinds of machines and is widely utilized . In this study, we intended to clarify the relationship between the concentration of chloride and pH in the bactericidal effects with acidic electrolyzed water . The effects of weak or strong acidic electrolyzed water were compared with a pseudo-acidic water of pH adjusted by diluted hydrochloric acid and sodium hydroxide, on Staphylococcus aureus, Staphylococcus epidermidis and Pseudomononas aeruginosa . At pH 5.0 approximately 6.0, 3 bacterial strains were killed soon after being exposed to the acidic water containing chloride 50 mg/liter, and the amount of chloride did not change after allowing to stand open for 6 hours . At pH 2.67 approximately 2.80, the bactericidal effects was observed at the concentration of chloride 5 mg/liter, and 80% of chloride remained after allowing to stand for 6 hours . These results indicated that newly made strong acidic water is more effective under a smaller amount of chloride at pH 2.7, and that weak acidic electrolyzed water should be used, if stable bactericidal effect is expected in cleaning the surroundings.

Changgeng Yi Xue Za Zhi, 1996 Sep, 19(3), 241 - 6
Staphylococcal pyomyositis; Lee SS et al.; Pyomyositis, a suppurative infection of the skeletal muscle, is uncommon and frequently misdiagnosed . Staphylococcus aureus has been reported as the most common causative organism in the tropics . The purposes of this study were to examine the clinical courses including presentations, treatments, and final outcomes of Staphylococcal pymyositis in Chang Gung Memorial Hospital and to suggest a treatment modality for this disorder . From July 1985 to June 1994, 12 patients were treated in this hospital for Staphylococcal pyomyositis . There were 9 males and 3 females, whose mean age was 22.1 years . The involved patients were either in the first two or in the fifth to seventh decades of life . Fever was found in all of them . The average time lag in diagnosis was 11.8 days from the onset of minor symptoms . The Gallium-67 scan was very sensitive and valuable in localization of the disease . Debridement or surgical drainage of the abscess was done in 11 patients . All the patients recovered after between 4 and 6 weeks of adequate antibiotic treatment without major abnormalities and complications . In summary, Staphylococcal pyomyositis is a rather benign disease . However, diagnosis is often delayed due to its vague presentation and lack of clinical suspicion . Unfamiliarity with this disease may be an obstacle to appropriate management.

Nippon Kyobu Geka Gakkai Zasshi, 1996 Sep, 44(9), 1767 - 71
{MRSA-induced prosthetic valve endocarditis complicated by synthetic graft infection that did not respond to repeated vancomycin administration but improved after surgery}; Tanaka K et al.; We performed AVR and OMC in a 55-year-old male with ASR complicated by MS and ASO . Postoperatively, an ulcer formed on the left lower extremity, resulting in methicillin-resistant Staphylococcus aureus (MRSA) infection . Axillo-bilateral-femoral artery bypass was performed using synthetic grafts . However, infection developed in the anastomosis site, leading to MRSA sepsis . Since MRSA is highly susceptible to vancomycin (VCM), this drug was administered at a dose of 1.5 g/day . With negative conversion of MRSA, the infected wound healed, and the general status improved . However, after discontinuation of VCM administration, sepsis recurred . VCM administration was resumed with prolongation of the administration period and an increase in the dose . Drug administration was discontinued 3 times after 2-4 weeks each, but recurrence was observed each time . During this period, AR due to prosthetic valve endocarditis (PVE) developed . AVR and MVR were performed again, and the synthetic graft was left in place . However, after discontinuation of postoperative VCM administration, infection of the synthetic graft was also demonstrated . The graft was removed, and revascularization was performed by another route . The patient improved after these procedures . When MRSA-induced PVE or synthetic graft infection develops, the infectious foreign material should be completely removed at an early stage before progression of tissue destruction or ulcer formation even if antibiotics are effective.

Nippon Kyobu Geka Gakkai Zasshi, 1996 Sep, 44(9), 1763 - 6
{A case of ischemic necrosis on anterior chest wall and mediastinitis after coronary artery bypass grafting using bilateral internal thoracic arteries and inferior epigastric arteries}; Uchida N et al.; Coronary artery bypass grafting using bilateral internal thoracic arteries and inferior epigastric arteries was performed in a 72-year-old man with multiple coronary artery disease who had a history of gastrectomy 25 years before . He postoperatively suffered from ischemic necrosis on anterior chest wall and mediastinitis caused by methicillin resistant staphylococcus aureus and aortic rupture . He got over by drainage at twice, hemostasis of aortic rupture and long-term irrigation using vancomycin . We must not perform coronary artery bypass grafting using bilateral internal thoracic arteries and inferior epigastric arteries at same time.

J Pharm Pharmacol, 1996 Sep, 48(9), 988 - 91
The antistaphylococcal effect of nisin in a suitable vehicle: a potential therapy for atopic dermatitis in man; Valenta C et al.; Staphylococcus aureus plays a central role in the pathogenesis of atopic dermatitis and is the predominant microorganism both in the lesions and in adjacent clinically normal skin . Chronic infection might aggravate the underlying lesion and serve as a source for further S . aureus infection . Nisin is a non-toxic and non-irritant peptide with no antibiotic-like side effects . In this study the antistaphylococcal activity of nisin in six topical formulations was investigated in diffusion tests and is shown to depend both on the water content and on the technological system . Because topical products often adhere to the stratum corneum for only a short time, the kinetics of antimicrobial activity were examined using a membrane filter technique . Thirty minutes after nisin addition almost no living microorganisms were detectable in different aqueous samples . The results demonstrate the potential of nisin preparations as an alternative to common antibiotics in the treatment of S . aureus infections in atopic dermatitis.

Mol Microbiol, 1996 Sep, 21(6), 1227 - 37
Transcriptional control of the agr-dependent virulence gene regulator, RNAIII, in Staphylococcus aureus; Morfeldt E et al.; Many of the genes coding for extracellular toxins, enzymes and cell-surface proteins in Staphylococcus aureus are regulated by a 510 nt RNA molecule, RNAIII . Expression of the RNAIII gene is positively controlled by the closely linked agr operon, which encodes a multicomponent signal-transduction system, and by an unlinked operon called sar . We have analysed the 120 bp region that separates the RNAIII promoter, P3, from the divergent agr promoter, P2 . By transcription analysis, it was shown that P3 can function in trans of the agr operon . A stretch of 53 bp upstream of P3, containing an interrupted repeat of 7 bp, was found to be required for the agr-dependent expression of RNAIII . A single cytoplasmic protein was shown to bind to at least two sites within this regulatory region . The protein, which was absent in extracts from a sarA mutant, was identified as the sarA product by N-terminal amino acid sequencing . A DNA fragment from the P2 region, encompassing an almost identical repeated DNA motif, competed for the same protein . No interaction between the regulatory DNA sequence and any agr-dependent products could be demonstrated . The results of this study suggest that P3 and P2 are controlled by a mechanism involving the binding of the SarA protein to multiple sites within the regulatory regions immediately upstream of each promoter, and the as yet unknown activity of AgrA.

Toxicon, 1996 Sep, 34(9), 987 - 1001
Two neurotoxins (BmK I and BmK II) from the venom of the scorpion Buthus martensi Karsch: purification, amino acid sequences and assessment of specific activity; Ji YH et al.; Two neurotoxins, BmK I and BmK II, were purified from the venom of the Chinese scorpion Buthus martensi Karsch . The complete amino acid sequences of both toxins, each containing 64 amino acid residues, were determined by the automatic sequencing of reduced and S-carboxymethylated toxins and their peptides, obtained after cleavage with TPCK-treated trypsin and Staphylococcus aureus V8 protease, respectively . Toxicity as minimum lethal dose tested by i.c.v . injection in mice showed that BmK I was six times more potent than BmK II . Only two amino acid replacements were found: at position 59 Val in BmK I was replaced by Ile in BmK II, and at position 62 a basic Lys residue in BmK I was substituted by a neutral Asn residue in BmK II . These features suggest that the positively charged residue (Lys or Arg) in the C-terminal position 62 (or 61 or 63) may also play an important role in facilitating the interaction between scorpion neurotoxins and the receptor on sodium channels . The effects of BmK I on nerve excitability were examined with the crayfish axon using intracellular recording and voltage-clamp conditions . The results indicate that BmK I preferentially blocks the sodium channel inactivation process . Thus, functional and structural similarities suggest that BmK I and BmK II belong to group 3 of scorpion alpha-type toxins.

Nucl Med Commun, 1996 Sep, 17(9), 805 - 9
Is 201Tl a reliable agent in tumour imaging?
Ozcan Z, Burak Z, Ozcan C, Basdemir G, Ozacar T, Erdem S, Duman Y.
Thallium-201 (201Tl) imaging has been widely used to differentiate post-therapy reactions from residual viable tumour or local recurrence . However, the ability of 201Tl to discriminate between tumour and post-therapy changes with superimposed infection/inflammation is unclear . This experimental study investigated the localization of 201Tl in infected/inflamed tissues . Twenty-four rats infected with Staphylococcus aureus and 10 rats injected with a standard volume of saline solution (SS) into the thigh muscles were studied . Twenty-four ours after microorganism or SS administration, 18 MBq 201Tl was injected intravenously . Images were recorded at 20 min and 3 h post-injection . The increased tracer uptake was evaluated qualitatively and quantitatively by calculating the ratios (L/C) derived from regions of interest drawn over the lesion and the contralateral thigh muscle . After the imaging procedure, histopathological examination was also performed . Whereas the control group showed no abnormal accumulation of activity, the infected rats demonstrated markedly increased activity, especially on the 20 min images . The mean L/C ratios for the 20 min and 3 h images for the infected rats were 2.18 +/- 0.20 and 1.52 +/- 0.04, respectively (P < 0.0005) . In conclusion, positive uptake due to an infective process may limit the use of 201Tl in studies monitoring response to tumour therapy . Although delayed imaging may help to overcome this limitation, further investigations among a large series of patients are required in order to improve the reliability of 201Tl imaging in oncology.

Nucl Med Commun, 1996 Sep, 17(9), 742 - 8
Labelled Stealth liposomes in experimental infection: an alternative to leukocyte scintigraphy?
Oyen WJ, Boerman OC, Storm G, van Bloois L, Koenders EB, Crommelin DJ, van der Meer JW, Corstens FH.
Indium-111 (111In) and technetium-99m (99Tcm) Stealth liposomes were compared with 111In- and 99Tcm-labelled white blood cells (WBC) in experimental infection in a rabbit model . Preformed polyethylene glycol-coated liposomes and separated WBC were radiolabelled with either 111In-oxine or 99Tcm-hexamethylpropyleneamine oxime (99TcM-HMPAO) . After the intravenous administration of one of the four radiopharmaceuticals to rabbits with focal Staphylococcus aureus infection, scintigraphic images were recorded at various time points post-injection and the biodistribution of the radiopharmaceuticals was determined . At 4 h post-injection, uptake of 111In-WBC in the abscess was significantly higher than that of the three other products . AT later time points, 111In-WBC, 111In-liposome and 99Tcm-liposome uptake in the abscess were similar . In contrast, a 20 h post-injection, uptake of 99Tcm-WBC was significantly lower . The abscess-to-background ratios showed a similar pattern to the absolute abscess uptake: initial high values for 111In-WBC, a more gradual increase over time of the liposome preparations to the level of 111In-WBC and persistently low values for 99Tcm-WBC . Clearance from the blood of both labelled WBC preparations was significantly faster and splenic uptake significantly higher compared with those of the labelled liposomes . In conclusion, given the similar in vivo characteristics of labelled liposomes and labelled WBC, labelled liposomes may be an attractive replacement for labelled WBC, providing a continuously available, high-quality, 99Tcm-labelled radiopharmaceutical that can be prepared easily without any need to handle blood.

Comp Immunol Microbiol Infect Dis, 1996 Sep, 19(4), 283 - 8
In vivo effect of teicoplanin and vancomycin upon haemolytic and bactericidal activity of serum against Staphylococcus aureus; Rodriguez AB et al.; The present study was undertaken to determine whether teicoplanin and vancomycin influence the hemolytic and bactericidal activity of serum obtained from mice (Swiss, aged 15 +/- 2 weeks) . Haemolytic activity was measured in CH-50 units (which represents the capacity of serum complement to lyse 50% of sheep red blood cells in the presence of specific antibody) and the bactericidal activity was estimated from the number of colony-forming units (CFU/ml) of Staphylococcus aureus that survived after 24 h of incubation in the presence of serum . The results indicate that (1) teicoplanin and vancomycin increase the haemolytic activity of serum; (2) in the serum from animals treated with both teicoplanin or vancomycin, the number of CFU/ml of Staphylococcus aureus declines; and (3) these antibiotics appear to have a similar effect upon the complement system.

J Antimicrob Chemother, 1996 Sep, 38(3), 543 - 6
Mutations in the gyrA and grlA genes of quinolone-resistant clinical isolates of methicillin-resistant Staphylococcus aureus; Takahata M et al.; The mutations in the quinolone-resistance determining regions (QRDR) of the gyrA, gyrB and grlA genes and in the norA gene from five clinical isolates of methicillin resistant Staphylococcus aureus (MRSA) were examined by DNA sequencing . The mutation from Ser84 to Leu in GyrA was associated with relatively high-level resistance to quinolones, whereas the mutation from Glu88 to Gly or Lys in GyrA was associated with low-level resistance to quinolones . Mutations of the grlA gene were observed at codon 80 (Ser80) or 84 (Glu84), independent of the mutations of gyrA . No mutations were observed in either the gyrB or norA genes.

Cutis, 1996 Sep, 58(3), 227 - 9
Cutaneous herpes simplex virus, type I, in association with Staphylococcus aureus in an infant; Vinson RP et al.; A 9-month-old infant was diagnosed as having impetigo of the central face . Her clinical condition deteriorated despite treatment with intravenous antibiotics . Viral and bacterial cultures grew herpes simplex virus type I and Staphylococcus aureus, respectively . The patient's condition improved rapidly with antiviral treatment in combination with antibiotics . Recognition of the possibility of a combined viral and bacterial infection is important so that adequate treatment is not delayed.

Protein Sci, 1996 Sep, 5(9), 1907 - 16
Coupling between trans/cis proline isomerization and protein stability in staphylococcal nuclease; Truckses DM et al.; The nucleases A produced by two strains of Staphylococcus aureus, which have different stabilities, differ only in the identity of the single amino acid at residue 124 . The nuclease from the Foggi strain of S . aureus (by convention nuclease WT), which contains His124, is 1.9 kcal.mol-1 less stable (at pH 5.5 and 20 degrees C) than the nuclease from the V8 strain (by convention nuclease H124L), which contains Leu124 . In addition, the population of the trans conformer at the Lys116-Pro117 peptide bond, as observed by NMR spectroscopy, is different for the two variants: about 15% for nuclease WT and 9% for nuclease H124L . In order to improve our understanding of the origin of these differences, we compared the properties of WT and H124L with those of the H124A and H124I variants . We discovered a correlation between effects of different residues at this position on protein stability and on stabilization of the cis configuration of the Lys116-Pro117 peptide bond . In terms of free energy, approximately 17% of the increase in protein stability manifests itself as stabilization of the cis configuration at Lys116-Pro117 . This result implies that the differences in stability arise mainly from structural differences between the cis configurational isomers at Pro117 of the different variants at residue 124 . We solved the X-ray structure of the cis form of the most stable variant, H124L, and compared it with the published high-resolution X-ray structure of the cis form of the most stable variant, WT (Hynes TR, Fox RO, 1991, Proteins Struct Funct Genet 10:92-105) . The two structures are identical within experimental error, except for the side chain at residue 124, which is exposed in the models of both variants . Thus, the increased stability and changes in the trans/cis equilibrium of the Lys116-Pro117 peptide bond observed in H124L relative to WT are due to subtle structural changes that are not observed by current structure determination technique . Residue 124 is located in a helix . However, the stability changes are too large and follow the wrong order of stability to be explained simply by differences in helical propensity . A second site of conformational heterogeneity in native nuclease is found at the His46-Pro47 peptide bond, which is approximately 80% trans in both WT and H124L . Because proline to glycine substitutions at either residue 47 or 117 remove the structural heterogeneity at that position and increase protein stability, we determined the X-ray structures of H124L + P117G and H124L + P47G + P117G and the kinetic parameters of H124L, H124L + P47G, H124L + P117G, and H124L + P47G + P117G . The individual P117G and P47G mutations cause decreases in nuclease activity, with kcat affected more than Km, and their effects are additive . The P117G mutation in nuclease H124L leads to the same local conformational rearrangement described for the P117G mutant of WT (Hynes TR, Hodel A, Fox RO, 1994, Biochemistry 33:5021-5030) . In both P117G mutants, the loop formed by residues 112-117 is located closer to the adjacent loop formed by residues 77-85, and residues 115-118 adopt a type I' beta-turn conformation with the Lys116-Gly117 peptide bond in the trans configuration, as compared with the parent protein in which these residues have a typeVIa beta-turn conformation with the Lys116-Pro117 peptide bond in the cis configuration . Addition of the P47G mutation appears not to cause any additional structural changes . However, the electron density for part of the loop containing this peptide bond was not strong enough to be interpreted.

Int J Food Microbiol, 1996 Sep, 32(1-2), 185 - 97
Composition and toxigenic potential of the mould population on dry-cured Iberian ham; Nunez F et al.; The fungal population on dry-cured Iberian ham can be essential to the development of the product's unique characteristics, but health hazards due to mycotoxins may be significant . We examined the natural fungal population of Iberian hams during ripening at three different locations . Chloroform extracts from 59 selected isolates were tested for toxicity to brine shrimp larvae and VERO cells, for mutagenicity in the Ames test and for antimicrobial activity against Staphylococcus aureus . The diversity of moulds increased during ripening . Penicillium commune, Penicillium chrysogenum, Penicillium aurantiogriseum, Penicillium expansum and Penicillium echinulatum dominated most of the ripening time; however, the Eurotium species, particularly E . herbariorum and E . repens, increased in the final product . Using the above tests, most moulds were toxigenic . The toxigenic potential of the fungal population increased as the processing progressed . To minimize health hazards from uncontrolled fungal populations, we identified non toxigenic strains of Penicillium chrysogenum that could be used as starters in dry-cured hams.

Eur Respir J, 1996 Sep, 9(9), 1955 - 7
Association between Wegener's granulomatosis and Staphylococcus aureus infection?
van Putten JW, van Haren EH, Lammers JW.
Two patients are presented with Wegener's granulomatosis (WG) and lower respiratory tract infections with Staphyloccus aureus (SA) . It is posulated that there is a relationship between the infection and the induction or relapse of the disease . We suggest that bronchoalveolar lavages should be performed in cases of suspected WG to identify SA-infections . The co-existence of WG and SA support the reported beneficial effects of sulfamethoxazole/trimethoprim, but needs further evaluation in patients with and without SA-infection of the airways.

Antimicrob Agents Chemother, 1996 Sep, 40(9), 2121 - 5
Penicillin-binding protein 4 overproduction increases beta-lactam resistance in Staphylococcus aureus; Henze UU et al.; The Staphylococcus aureus mutant strain PVI selected in vitro for methicillin resistance overexpressed penicillin-binding protein (PBP) 4 . In the wild-type parent strain the pbp4 gene was separated by 419 nucleotides from a divergently transcribed abcA locus coding for an ATP-binding cassette transporter . The mutant PVI was shown to have a deletion in the pbp4-abcA promoter region that affected pbp4 transcription but not expression of abcA . Introduction of the pbp4 gene plus the mutant promoter region into different genetic backgrounds revealed that PBP 4 overproduction was sufficient to increase in vitro-acquired methicillin resistance independently of other chromosomal genes . The role of the AbcA transporter in methicillin resistance remained unknown.

Antimicrob Agents Chemother, 1996 Sep, 40(9), 2111 - 6
Efficacy of sparfloxacin and autoradiographic diffusion pattern of {14C}Sparfloxacin in experimental Staphylococcus aureus joint prosthesis infection; Cremieux AC et al.; Using a new rabbit model of methicillin-susceptible Staphylococcus aureus knee prosthesis infection, we compared the efficacies of sparfloxacin (50 mg/kg of body weight subcutaneously, twice a day) and pefloxacin (50 mg/kg subcutaneously, twice a day) . A partial knee replacement was performed with a silicone implant fitted into the intramedullary canal of the tibia, and 5 x 10(7) CFU of methicillin-susceptible S . aureus was injected into the knee . The 7-day treatment regimen was started 15 days later . The MICs and MBCs of sparfloxacin and pefloxacin were, respectively, 0.06 and 0.25 microgram/ml (MIC) and 0.25 and 1 microgram/ml (MBC) . The peak levels of sparfloxacin and pefloxacin in serum were 3.6 and 21 micrograms/ml, respectively . Three weeks after the end of treatment, animals were sacrificed and tibias were removed, pulverized, and quantitatively cultured . In contrast to pefloxacin (3.61 +/- 1.64 log10 CFU/g of bone), sparfloxacin significantly reduced the bacterial density (2.12 +/- 1.1 log10 CFU/g of bone) (P = 0.01) in comparison with the level in controls (4.59 +/- 1.21 log10 CFU/g of bone), without selection of resistant variants . Sparfloxacin was significantly more effective than pefloxacin (P = 0.025) . The autoradiographic pattern of {14C}sparfloxacin diffusion was studied in noninfected animals with prostheses and in infected animals 15 days after inoculation . Sixty minutes after completion of infusion of 250 microCi of {14C}sparfloxacin, in infected animals the highest levels of radioactivity were detected around the prosthesis, in femoral cartilage, and in articular ligaments . Radioactivity was slightly less intense in bone marrow and muscles and was very weak in compact bone . The distribution of sparfloxacin in uninfected rabbits was similar . Thus, sparfloxacin may represent a valid alternative therapy in these infections provided that it is carefully monitored for potential side effects.

Antimicrob Agents Chemother, 1996 Sep, 40(9), 2075 - 9
Specific interaction between beta-lactams and soluble penicillin-binding protein 2a from methicillin-resistant Staphylococcus aureus: development of a chromogenic assay; Roychoudhury S et al.; We investigated the enzymatic acylation of penicillin-binding protein 2a (PBP 2a) from methicillin-resistant Staphylococcus aureus by beta-lactams . Using a purified, soluble form of the protein (PBP 2a'), we observed beta-lactam-induced in vitro precipitation following first-order kinetics with respect to protein concentration . We used electrospray mass ionization spectrometry to show that the protein precipitate predominantly contained PBP 2a', with the beta-lactam bound to it in a 1:1 molar ratio . Using nitrocefin, a chromogenic beta-lactam, we confirmed the correlation between PBP 2a' precipitation and its beta-lactam-dependent enzymatic acylation by monitoring the absorbance associated with the precipitate . Finally, dissolving the precipitate in urea, we developed a simple in vitro chromogenic assay to monitor beta-lactam-dependent enzymatic acylation of PBP 2a' . This assay represents a significant improvement over the traditional radioactive penicillin-binding assay.

Chemotherapy, 1996 Sep-Oct, 42(5), 354 - 62
Pharmacodynamic effects of ciprofloxacin, fleroxacin and lomefloxacin in vivo and in vitro; Fuentes F et al.; The present study investigates the postantibiotic effect (PAE) in vivo, and the postantibiotic subinhibitory concentration effects (PA-SE) in vitro and SE in vivo of three 4-fluoroquinolones (ciprofloxacin, fleroxacin and lomefloxacin) against standard strains of Staphylococcus aureus and Escherichia coli . In vivo killing kinetics have also been performed using two different short administrations to study if the PAE duration could cover the time that the antibiotic was below the minimal inhibitory concentration (MIC) in serum . The results show that the three antimicrobial agents induced long PAEs (1.9-3.1 h) against the two microorganisms . Moderate but significant in vitro PA-SEs were also produced (1-->9 h) . The in vivo SEs were not significant except when the effect of lomefloxacin on E . coli was assayed (0.54 h) . Finally, the in vivo killing kinetics showed that the administrations that included the PAE duration were as effective as the schedule that maintained the antibiotic levels in serum above the MIC . Only when fleroxacin and S . aureus were assayed, this last administration was more effective (+0.9 log10 colony-forming units/thigh).

Am J Vet Res, 1996 Sep, 57(9), 1308 - 11
Effect of antibodies to staphylococcal alpha and beta toxins and Staphylococcus aureus on the cytotoxicity for and adherence of the organism to bovine mammary epithelial cells; Cifrian E et al.; OBJECTIVE: To determine the effect of antibodies to staphylococcal alpha and beta toxins and Staphylococcus aureus on the toxicity for and adherence of S aureus to bovine mammary epithelial cells . SAMPLE POPULATION: Cultured bovine mammary epithelial cells and Staphylococcus aureus obtained from a cow with mastitis . PROCEDURE: Cultured bovine epithelial cells were incubated with antisera to alpha and beta toxins of S aureus and culture supernatant; cell damage and S aureus adherence to cells were measured . RESULTS: Antisera to alpha, beta, and alpha + beta toxins inhibited cytotoxicity of S aureus culture supernatant . Antiserum to alpha + beta toxin was the most effective inhibitor of cytotoxicity and antiserum to beta toxin was the least effective . All 3 antisera decreased the percentage of S aureus adhered to the mammary epithelial cell monolayers and numbers of organisms per cluster of adhered bacteria . In this study, antisera to alpha and alpha + beta toxins decreased the number of S aureus clusters per dish, but antiserum to beta toxin had no significant effect . Antiserum to alpha + beta toxin decreased the percentage of epithelial cells with adhered S aureus, but neither antiserum to alpha nor beta toxin had significant effect . Antiserum to S aureus decreased the percentage of S aureus adhered, number of clusters perdish, number of organisms per cluster, and percentage of epithelial cells with S aureus adhered . CONCLUSIONS: Antibodies to staphylococcal alpha and beta toxins inhibit adherence to and cytotoxicity of S aureus for bovine mammary epithelial cells, and antibodies to S aureus inhibit adherence of S aureus to bovine mammary epithelial cells.

J Clin Microbiol, 1996 Sep, 34(9), 2267 - 9
Comparison of five tests for identification of Staphylococcus aureus from clinical samples; Luijendijk A et al.; Five different laboratory tests for the identification of Staphylococcus aureus were compared . Analyses of 271 presumptive S . aureus strains, supplemented with 59 well-defined methicillin-resistant S . aureus (MRSA) isolates, were performed . Only the Staphaurex Plus (Murex Diagnostics, Dartford, United Kingdom) and the Pastorex Staphplus (Sanofi, Marnes-La-Coquette, France) tests displayed 100% sensitivity . The observed difference with the free-coagulase test (Bacto coagulase plasma; Difco, Detroit, Mich.), a bound-coagulase (clumping factor) test, and the former Staphaurex test (Murex Diagnostics) was caused mainly by the inability of these three tests to identify some MRSA strains correctly . Among Polish MRSA isolates included in the analysis, a group of free-coagulase-negative S . aureus strains was detected . Genetic typing by random amplification of polymorphic DNA revealed that the strains showing aberrant behavior when the different test results were compared belonged to limited number of S . aureus clones.

J Clin Microbiol, 1996 Sep, 34(9), 2121 - 4
Methicillin-resistant Staphylococcus aureus isolates recovered from a New York City hospital: analysis by molecular fingerprinting techniques; de Lencastre H et al.; Fifty-five methicillin-resistant Staphylococcus aureus (MRSA) isolates collected at New York Hospital Medical Center of Queens in 1989 were analyzed by molecular fingerprinting techniques . Close to 70% of these isolates (38 of 55) shared a common pulsed-field gel electrophoretic pattern, carried the same mecA gene polymorph type II, were free of the transposon Tn554, and would not react with a mecI-specific gene probe . An additional five isolates shared all properties of the major MRSA clone except that they carried mecA gene polymorph type III . All these isolates had an extremely heterogeneous methicillin resistance phenotype that belonged to population analysis profile class 1 or 2 . The rest of the 12 MRSA isolates showed a variety of chromosomal pulsed-field gel electrophoretic patterns that carried different mecA polymorphs and that also gave positive reactions with DNA probes for Tn554 and for the mecI gene . The molecular features of the majority MRSA clone suggest that it is an archaic MRSA isolate similar in features to early MRSA isolates recovered in the 1960s.

J Natl Med Assoc, 1996 Sep, 88(9), 565 - 9
Nontropical pyomyositis in patients with AIDS; Antony SJ et al.; Nontropical pyomyositis in persons with acquired immunodeficiency syndrome (AIDS) is an unusual entity with only a few cases having been described in the United States . Staphylococcus aureus is the most common organism implicated . The infection usually presents in a subacute indolent fashion with minimal inflammation . Fever and leukocytosis may be absent, and blood cultures are frequently negative . The diagnosis usually can be established by a combination of clinical features, computed tomography or ultrasound, and prompt examination of material obtained by aspiration or debridement . This article describes two cases of S aureus pyomyositis in patients with AIDS and reviews the literature relevant to this infection.

Microbiology, 1996 Sep, 142 ( Pt 9), 2453 - 61
Mycobacterium xenopi IS1395, a novel insertion sequence expanding the IS256 family; Picardeau M et al.; An insertion sequence (IS) of Mycobacterium xenopi has been isolated and sequenced . This 1323 bp element, designated IS1395, is present in up to 18 copies in the M . xenopi genome and may be harboured in an M . xenopi extrachromosomal element . It encodes a putative transposase of 415 amino acids which displays sequence homology to the Staphylococcus aureus IS256 family . Members of this class of elements have been described in the genus Mycobacterium-for example IS1081 is present in the M . tuberculosis complex, IS1245-IS1311 in M . avium, and IS6120 in M . smegmatis; these elements exhibit an 89%, 45% and 16% amino acid identity with IS1395, respectively . Investigation of the host range of IS1395 by Southern blot analysis revealed additional IS1395-related repeated sequences in M . gordonae and M . celatum . Moreover, IS1395 represents a useful epidemiological tool for M . xenopi strain typing as it provides a diversity of restriction fragment length polymorphism patterns.

J Cell Physiol, 1996 Sep, 168(3), 638 - 47
Involvement of CD44 and the cytoskeletal linker protein ankyrin in human neutrophil bacterial phagocytosis; Moffat FL Jr et al.; The leukocyte CD44 and CD45 cell surface receptors are associated via the linker proteins ankyrin and fodrin with the cytoskeleton, which itself is important in immune cell functions such as adherence, chemotaxis, and phagocytosis . The effects of rat antihuman CD44 and CD45 monoclonal antibodies on phagocytosis of fluoresceinated heat-killed Staphylococcus aureus 502A by normal human neutrophils (PMNs) during 2 hr incubation in RPMI-1640 was studied via flow cytometry and confocal microscopy . Flow cytometry was performed using an excitation wavelength of 488 nm, fluorescence being measured at 515-560 nm on 50,000 PMNs per sample . Confocal microscopy was performed on samples after further incubation with rhodamine-conjugated antiankyrin . Anti-CD44 resulted in an increase of 27-31% compared to control (P = 0.004) in the proportion of PMNs fluorescing, an increase of 17-24% (P = 0.001) in mean intracellular fluorescence per PMN, and an increase in total PMN fluorescence of 50-58% compared to control (P < 0.001) . In contrast, anti-CD45 had little effect on phagocytosis . Colchicine (a microtubule-disrupting agent) enhanced, whereas cytochalasin-D (a microfilament inhibitor) inhibited bacterial phagocytosis; cytochalasin-D completely abrogated the effect of anti-CD44 on this PMN function . Hyaluronic acid augmented phagocytosis by an increment similar to that observed with anti-CD44 . Two-color flow cytometry and confocal microscopy demonstrated that ankyrin always colocalized with ingested fluorescein isothiocyanate (FITC)-labeled bacteria . These data strongly suggest that CD44 is involved in bacterial phagocytosis, provide further evidence of CD44 receptor linkage to cytoskeletal elements in human leukocytes, and suggest that ankyrin has a significant role in the transport of phagosomes.

Arthritis Rheum, 1996 Sep, 39(9), 1596 - 605
Addition of corticosteroids to antibiotic treatment ameliorates the course of experimental Staphylococcus aureus arthritis; Sakiniene E et al.; OBJECTIVE: To evaluate the combined effect of systemic corticosteroid and antibiotic therapy on the course of septic arthritis . METHODS: The murine model of hematogenously acquired Staphylococcus aureus arthritis was used . Mice were treated with corticosteroids and antibiotics, and were followed up individually . Arthritis was evaluated clinically and histopathologically . Serum samples and bacterial isolates were also analyzed . RESULTS: The prevalence of arthritis 14 days after the onset of the disease was 22% in the corticosteroid and antibiotic-treated group, as compared with 81% in the control (nontreated) group and 48% in the antibiotic-treated group . The severity of arthritis also decreased in the corticosteroid and antibiotic-treated group, as did the mortality rate . Immunohistochemical analysis revealed a dramatic decrease in T cells and macrophages in the synovium of mice that took the combined therapy . The mechanisms leading to this outcome include the inhibitory effect of corticosteroids on T cell and B cell proliferation and differentiation, such as suppression of interferon-gamma (IFN gamma) production . Serum levels of IFN gamma were decreased 4-fold in the antibiotic-treated group compared with the controls; a 15-fold decrease was observed in the corticosteroid and antibiotic-treated animals . In addition, serum NO3- was significantly decreased in mice treated with antibiotics (P < or = 0.05), as well as in mice treated with corticosteroids and antibiotics (P < or = 0.001) . CONCLUSION: Systemic corticosteroid administration along with antibiotic therapy had beneficial effects on the course and outcome of S aureus arthritis.

Clin Immunol Immunopathol, 1996 Sep, 80(3 Pt 2), S73 - 81
Modulation of B-cell immunoglobulin synthesis by retinoic acid; Ballow M et al.; Retinoic acid (RA) and its parent compound retinol (ROH, vitamin A) have been recognized as important immunopotentiating agents since the early 1900s . We have focused our studies on the effects of retinoids on B-cell immune function in the newborn infant . The response of cord blood mononuclear cells (CBMC) to formalinized Cowan I strain Staphylococcus aureus (SAC), a T-cell-dependent factor for inducing the differentiation of B cells into immunoglobulin (Ig)-secreting cells, was used as a model system for studying whether RA could alter the immunoglobulin synthesis of newborn B lymphocytes . The addition of RA to SAC-stimulated CBMC cultures produced a 2- to 47-fold increase in IgM synthesis . An ELISA-spot assay showed that the RA-induced enhancement in Ig synthesis was due to the recruitment of more B cells to differentiate into Ig-secreting cells . Whereas RA enhanced IgM production of CBMC stimulated with SAC, RA augmented only IgG production of SAC-stimulated adult peripheral blood mononuclear cells (PBMC) . To determine if the differences in dose-response characteristics between CBMC and adult PBMC resided within the target cell, i.e., the B cell, T-cell-enriched and T-cell-depleted (B-cell) fractions from CBMC and adult PBMC were cocultured in various combinations . The isotype, i.e., IgM vs IgG, and the dose-response curve characteristics were intrinsic to the responding B-cell source, i.e., newborn vs adult . Highly purified T cells from CBMC, when preincubated for 36 hr with RA, enhanced IgM synthesis of cord blood B cells . Supernatants from purified T cells generated a factor which could enhance B-cell synthesis . Although interleukin (IL)-2, IL-4, and IL-6 could not be detected by ELISA in the T-cell-derived supernatants, RA probably generates a cytokine/interleukin from T cells which modulates B-cell Ig secretion . RA can also act directly on B cells as evidenced by the augmentation in Ig synthesis of Epstein-Barr virus (EBV)-transformed B-cell lines . These data suggest that RA can have a direct effect on B cells . Since increased proliferation (numbers) of lymphoblastoid B cells was not responsible for the increased amounts of Ig in the supernatant fluids, we examined whether cytokines secreted by EBV-transformed B cells could be acting as an autocrine factor in increasing Ig synthesis . EBV-transformed B-cell clones incubated with RA for 6 days produced a 20- to 45-fold increase in IL-6 . An understanding of the mechanisms by which RA enhances B-cell immune function may lead to the use of RA or its derivatives in patients with immune deficiencies and in preterm infants with immature immune systems.

J Med Microbiol, 1996 Sep, 45(3), 226 - 31
Comparison of bronchoalveolar lavage and catheter lavage to confirm ventilator-associated lower respiratory tract infection; Humphreys H et al.; Lower respiratory tract infection (LRTI) is a well recognised complication of artificial ventilation in intensive care units (ICU) . Ideally, specimens for microbiological analysis should be obtained during bronchoscopy, but this is not always possible . Therefore, the microbiological diagnosis of lower respiratory tract infection by broncho-alveolar lavage (BAL) obtained during bronchoscopy was compared with catheter lavage (CL) with a balloon-tipped catheter . Adult patients with clinical evidence of lower respiratory tract infection in an adult ICU were randomly assigned to undergo BAL followed by CL or vice versa . Forty ml of normal saline 0.9% were instilled and then aspirated with a flexible bronchoscope to obtain BAL . A similar volume was instilled and aspirated with a 12-gauge Foley balloon-tipped catheter to obtain a CL sample . The number of inflammatory cells, epithelial cells and organisms seen by microscopy were quantified . Culture results were semi-quantified and classified as negative, positive, equivocal or contaminated . Seventy-nine paired specimens were obtained from 66 patients, including specimens from 10 patients taken on two or more occasions . Only 20% of BAL and 16% of CL had one or more epithelial cells and bacteria were seen in 26 BAL and 21 CL specimens, respectively; 35% of BAL and CL specimens were positive and there was a discrepancy in the culture result in only two cases . Staphylococcus aureus was the pathogen isolated most frequently and polymicrobial lower respiratory infection was diagnosed on 10 occasions (15%) . CL fluid is as reliable as BAL in diagnosing lower respiratory tract infection in ICU . This approach does not require bronchoscopic expertise and utilises convenient laboratory techniques.

J Vasc Surg, 1996 Sep, 24(3), 472 - 6
In situ repair of mycotic abdominal aortic aneurysms with rifampin-bonded gelatin-impregnated Dacron grafts: a preliminary case report; Gupta AK et al.; Treatment of mycotic aortic aneurysm by excision and extraanatomic bypass is difficult to apply when the infectious process involves the visceral arteries . On the basis of experimental studies in our laboratory that demonstrated prolonged antistaphylococcal activity of rifampin-bonded, gelatin-impregnated Dacron grafts after implantation in the arterial circulation, this conduit was successfully used for in situ replacement of a native aortic infection in two patients . Both patients had fever, leukocytosis, abdominal or back pain, and a computed tomographic scan that demonstrated contained rupture of a mycotic aneurysm . Preoperative computed tomography-guided aspiration and culture of periaortic fluid from one patient grew Staphylococcus aureus . Treatment consisted of prolonged (6 weeks) culture-specific parenteral antibiotic therapy, excision of involved aorta, oxychlorosene irrigation of the aortic bed, and restoration of aortic continuity by in situ prosthetic replacement . A preliminary right axillobifemoral bypass was performed in the patient who had an infection involving the suprarenal and infrarenal aorta . In both patients intraoperative culture of aorta wall recovered S . aureus . Patients were discharged at 20 and 21 days . Clinical follow-up and computed tomographic imaging of the replacement graft beyond 10 months after surgery demonstrated no signs of residual aortic infection . In the absence of gross pus and frank sepsis, the use of an antibiotic-bonded prosthetic graft with antistaphylococcal activity should be considered in patients who have arterial infections caused by S . aureus when excision and ex situ bypass are not feasible.

J Thorac Cardiovasc Surg, 1996 Sep, 112(3), 681 - 6
Sternal wound infection after heart operations in pediatric patients associated with nasal carriage of Staphylococcus aureus; Ruef C et al.; A cluster of six pediatric cases of deep-seated Staphylococcus aureus infection after heart operations prompted us to perform molecular typing of the S . aureus isolates by pulsed-field gel electrophoresis . This revealed the presence of genotypically distinct isolates in four of the six patients . Isolates of two patients were genotypically identical . All patients carried S . aureus in the anterior nares . In each patient, the banding pattern of deoxyribonucleic acid in these isolates was indistinguishable from that in strains isolated from blood or wound cultures . Molecular typing with pulsed-field gel electrophoresis ruled out nosocomial transmission of S . aureus between four patients; at the same time, it provided evidence for an association between nasal colonization and postoperative wound infection . Epidemiologic investigation of potential links between two patients with identical isolates did not provide any evidence for nosocomial transmission of S . aureus between these patients . Because nasal colonization with S . aureus may be a risk factor for surgical wound infection in pediatric patients undergoing heart operations, preoperative decolonization appears to be warranted.

Appl Environ Microbiol, 1996 Sep, 62(9), 3274 - 6
Effect of urea treatment on recovery of staphylococcal enterotoxin A from heat-processed foods; Akhtar M et al.; The effects of urea treatment on the potential reactivation of heat-damaged antigenic components of staphylococcal enterotoxin A (SEA) were examined with cooked foods, including mushrooms, ham, bologna, salami, and turkey . The thermal stability of purified SEA spiked into foods and native SEA produced by Staphylococcus aureus in foods was also examined . Food samples containing either spiked or native SEA were thermally processed by autoclaving or retorting . This was followed sequentially by toxin extraction, urea treatment, dialysis, reconstitution, and SE assays with the reversed passive latex agglutination and/or enzyme immunoassay kit . The results indicate that (i) urea treatment did not result in any reactivation of heat-inactivated antigenic components of SEA in any of the foods tested, (ii) the serological components of purified SEA were destroyed (> or = 96%) by autoclaving at 121.1 degrees C for 5 to 15 min or by retorting at an F0 of 4 to 18, and (iii) the immunological property of the native SEA was approximately threefold-more heat resistant than that of the purified SEA . The study suggested that the current urea method is not suitable for the detection of heat-denatured SEA in the thermally processed foods.

Mol Pharmacol, 1996 Sep, 50(3), 482 - 92
BIBW22 BS, potent multidrug resistance-reversing agent, binds directly to P-glycoprotein and accumulates in drug-resistant cells; Liu Z et al.; The expression of P-glycoprotein (P-gp) in tumor cells causes a multidrug resistance (MDR) phenotype . P-gp has been shown to mediate the transport of structurally dissimilar drugs across the cell membrane in an energy-dependent manner . In this report, we show that BIBW22 BS, a phenylpteridine analog, reverses the MDR phenotype of CEM human lymphoma cells in a dose-dependent fashion . Using a photoactive analog of BIBW22 BS inverted question mark{3H}azido-4-{N-(2-hydroxy-2-methylpropyl)-ethanolamino}-2, 7-bis(cis-2,6-dimethyl-morpholino)-6-phenylpteridine inverted question mark, we show the photoaffinity labeling of a 170-kDa protein in drug-resistant cells immunoprecipitated with P-gp-specific monoclonal antibodies . The photolabeling of P-gp by {3H}azido-BIBW22 BS was specific and saturable . Furthermore, BIBW22 BS, vinblastine, and verapamil, but not colchicine, inhibited the photolabeling of P-gp by {3H}azido-BIBW22 BS . Drug binding studies showed that membranes from MDR cells bound more BIBW22 BS than parental drug-sensitive cells, and this binding was inhibited with vinblastine and, to a lesser extent, with uridine . However, drug transport studies demonstrated that BIBW22 BS is not a substrate for P-gp efflux pump . Interestingly, BIBW22 BS was shown to accumulate more in resistant cells . Also, BIBW22 BS accumulation in drug-sensitive and -resistant cells was not energy dependent . These results are in contrast with the observed decrease in accumulation or enhanced efflux of {3H}vinblastine seen in the same MDR cells . A comparison of {3H}azido-BIBW22 BS or {3H}azidopine photolabeled P-gp by Cleveland mapping with Staphylococcus aureus V8 protease showed differences in the photolabeled peptides . Taken together, the results of this study show that BIBW22 BS is a potent MDR-reversing agent that binds directly to P-gp but is not effluxed from drug-resistant cells.

J Inorg Biochem, 1996 Sep, 63(4), 291 - 300
An electron spin resonance study and antimicrobial activity of copper(II)-phenanthroline complexes; Zoroddu MA et al.; The antimicrobial activities of some copper(II) binary complexes with unsubstituted and different substituted phenanthroline ligands were investigated . A considerable increase in the biocidal activity of the ligands on being coordinated with the copper(II) ions was observed in terms of their minimum inhibitory concentration (MIC) values . EPR measurements were performed at room and low temperature with the aim of gaining an insight into the structure/activity relationship of these complexes . Subtle differences in the chemical arrangement result in appreciable differences in the antimicrobial activity . Copper(II) complexes with 2,9-dimethyl derivative phenanthrolines were observed to be more active against Staphylococcus aureus and Escherichia coli.

J Bacteriol, 1996 Sep, 178(17), 5327 - 9
Insertional inactivation of the gene for collagen-binding protein has a pleiotropic effect on the phenotype of Staphylococcus aureus; Hienz SA et al.; This report describes phenotypical changes caused by the insertional inactivation of the gene for the collagen-binding protein in Staphylococcus aureus PH100 . Insertional inactivation resulted in reductions in the amount of fibronectin-binding protein in PH100 and the ability of intact cells to aggregate in the presence of fibronectin . However, the capacity of PH100 to adhere to immobilized fibronectin remained the same.

Infect Immun, 1996 Sep, 64(9), 3512 - 7
Involvement of superoxide and myeloperoxidase in oxygen-dependent killing of Staphylococcus aureus by neutrophils; Hampton MB et al.; We have used a quantitative assay that measures independent rate constants for phagocytosis and killing of Staphylococcus aureus to investigate the involvement of superoxide and myeloperoxidase in bacterial killing by human neutrophils . To inhibit superoxide-dependent processes, superoxide dismutase was cross-linked to immunoglobulin G and the conjugate was attached to the surface of S . aureus via protein A in its cell wall . Myeloperoxidase was inhibited with azide, and myeloperoxidase-deficient neutrophils were used . Adding the NADPH oxidase inhibitor diphenyleneiodonium, to prevent superoxide production, decreased the killing rate to 25%, indicating that oxidative killing mechanisms predominate in this system . The rate constant for killing of S . aureus with superoxide dismutase attached was 70% of that for control bacteria linked to inactivated enzyme . Superoxide dismutase had no effect in the presence of diphenyleneiodonium . The rate of killing was decreased to 33% in the presence of azide and to 40% with myeloperoxidase-deficient neutrophils . Superoxide dismutase had no effect in the presence of azide . On the assumption that the oxidative and nonoxidative components of killing can be considered separately, the oxidative rate was decreased by almost half by superoxide dismutase and was about six times lower when myeloperoxidase was inactive . We conclude that myeloperoxidase-dependent processes are strongly favored by human neutrophils as their prime mechanism of oxidative killing of S . aureus and that superoxide makes a direct contribution to killing . Our results also suggest that superoxide acts in conjunction with a myeloperoxidase-dependent pathway.

J Chromatogr A, 1996 Aug 30, 743(1), 123 - 35
Reversed-phase high-performance liquid chromatographic separation of bovine kappa-casein macropeptide and characterization of isolated fractions; Minikiewicz P et al.; From complex mixtures of non-glycosylated and differently glycosylated caseinomacropeptides (CMP; kappa-casein fragment 106-169; M(r) approximately 7000) various fractions were isolated and further purified by reversed-phase HPLC . The fractions were characterized by mass determination and composition analysis and also used in gel-permeation chromatography and NMR studies to investigate their molecular size behaviour as a function of pH, ionic strength, peptide concentration and degree of glycosylation . No evidence was found for association of any CMP fraction as a function of the experimental conditions applied, which is in contrast with suggestions made in the literature . The increased molecular size (apparent molecular mass approx . 30-45 kDa) is rather explained by a large voluminosity of the molecular species due to internal electrostatic and steric repulsion . Furthermore, the susceptibility of some non-glycosylated and glycosylated CMP fractions to enzymic attack by the Glu-specific endopeptidase from Staphylococcus aureus V8 was studied . Initial rates of proteolysis by this enzyme were independent of the degree of glycosylation . Only in the case of highly glycosylated CMP was further hydrolysis to smaller fragments inhibited . Hydrolytic products were identified by electrospray ionization and fast-atom bombardment mass spectrometry.

Blood, 1996 Aug 15, 88(4), 1359 - 64
Bcl-x rather than Bcl-2 mediates CD40-dependent centrocyte survival in the germinal center; Tuscano JM et al.; Both rapid B-cell proliferation and programmed cell death (PCD) occur during the differentiation and selection of B cells within the germinal center . To help elucidate the role of Bcl-x in B-cell antigen selection and PCD within the germinal center, we examined its expression in defined B-cell populations and by immunochemistry of tonsil tissue . Purified B-cell fractions enriched for centrocytes express high amounts of Bcl-x and relatively low amounts of Bcl-2, whereas fractions enriched for centroblasts lack significant levels of both proteins . Consistent with this observation, immunocytochemistry localized Bcl-x within cells scattered throughout the germinal center . Stimulation of tonsil B cells with either CD40 or Staphylococcus aureus Cowan increase bcl-x mRNA and protein levels . Treatment of a cell line with a germinal center phenotype (RAMOS) or the tonsillar B-cell centroblast fraction with CD40 rapidly increased Bcl-x levels and partially rescued B cells from PCD . These data suggest that Bcl-x rather than Bcl-2 may rescue centrocytes during selection in the germinal center.

FEBS Lett, 1996 Aug 12, 391(3), 243 - 6
Transmembrane glutamic acid residues play essential roles in the metal-tetracycline/H+ antiporter of Staphylococcus aureus; Fujihira E et al.; Three transmembrane aspartyl residues play essential roles in the transposon Tn10-encoded metal-tetracycline/H+ antiporter (Tet(B)) {Yamaguchi, A . et al . (1992) J . Biol . Chem . 267, 7490-7498} . The tetK gene-encoding tetracycline resistance protein (Tet(K)) of Staphylococcus aureus mediates metal-tetracycline/H+ antiport similarly to Tet(B); however, it has no transmembrane aspartyl residue . On the other hand, Tet(K) has three glutamyl residues, Glu-30, Glu-152 and Glu-397, in the putative transmembrane regions . In the present work, tet(K) gene was expressed in Escherichia coli and the transport activity was measured in everted membrane vesicles . When these glutamyl residues were replaced with Gln, the tetracycline transport activity was almost completely lost, indicating the important roles of these residues in Tet(K) . In the case of Glu-397, even the charge-conserved mutation to Asp caused complete loss of the activity . On the other hand, the mutation of Glu-30 and Glu-152 to Asp resulted in significant retention of transport activity . These results are similar to those on the mutation of the three transmembrane aspartyl residues in Tet(B), indicating that the transmembrane glutamyl residues in Tet(K) play roles similar to those of the transmembrane aspartyl residues in Tet(B).

J Med Chem, 1996 Aug 2, 39(16), 3070 - 88
Synthesis and structure-activity relationships of 2-pyridones: a novel series of potent DNA gyrase inhibitors as antibacterial agents; Li Q et al.; Two novel series of 2-pyridones were synthesized by transposition of the nitrogen of 4-quinolones to the bridgehead position . This subtle interchange of the nitrogen atom with a carbon atom yielded two novel heterocyclic nuclei, pyrido{1,2-alpha}pyrimidine and quinolizine, which had not previously been evaluated as antibacterial agents and were found to be potent inhibitors of DNA gyrase . Quinolizines with a methyl group at the 9-position such as (S)-45a (ABT-719) demonstrate exceptional broad spectrum antibacterial activity . Most notably, they are active against resistant bacteria such as methicillin-resistant Staphylococcus aureus, vancomycin-resistant strains of enterococci, and ciprofloxacin-resistant organisms . In addition, 2-pyridones also possess favorable physiochemical and pharmacokinetic properties . These 2-pyridones were synthesized from the commercially available starting materials by 10-17 linear transformations . The structure of an adduct yielded by this sequence, (S)-45a (ABT-719), was determined by X-ray crystallographic analysis.

Appl Microbiol Biotechnol, 1996 Aug, 46(1), 61 - 6
IS431mec-mediated integration of a bleomycin-resistance gene into the chromosome of a methicillin-resistant Staphylococcus aureus strain isolated in Japan; Sugiyama M et al.; A methicillin-resistant Staphylococcus aureus (MRSA) strain B-26, isolated clinically in Hiroshima University Hospital, is resistant to bleomycin together with kanamycin . In the present study, we analysed the nucleotide sequence of the 5.1-kb HindIII fragment containing the bleomycin- and kanamycin-resistance genes, which were previously cloned {Bhuiyan et al . (1995) Appl Microbiol Biotechnol 43: 65-69} from the chromosomal DNA of MRSA B-26 . The present study found that the DNA sequence contains the duplicated target sequence (GATTAGAT) consisting of 8 bp for transposase and the entire nucleotide sequence of the plasmid pUB110, together with the sequence of inverted repeats (16 bp), designated IR-r and IR-1 in IS431 mec . The 8-bp duplication sequence, produced by the transposable element, was first found by us . We proposed that bleomycin resistance in MRSA B-26 is attributed to the IS431 mec-mediated integration of pUB110 into the chromosome.

Vet Med (Praha), 1996 Aug, 41(8), 241 - 4
{Antibiotic resistance in Staphylococcus aureus mastitis in sheep, sheep milk and its products}; Simko S et al.; A study of current resistance to antibiotics was conducted in 500 strains of Staphylococcus aureus isolated from ewes with clinical and latent mastitis, from sheep milk and products made from it (sheep lumpy cheese, bryndza cheese) . A diffusion disk method was used to assay 14 kinds of antibiotics (AMP, BAC, CEF, ERY, GEN, CMP, KAN, LIN, OXA, PEN, RIF, SPI, VAN, TET) and one chemotherapeutic drug (COT) . The highest resistance was observed in the cases of clinical mastitis (from 8% and 10% in COT and KAN to 68% and 69% in PEN and TET) . Resistance significantly decreased in 13 kinds of antibiotics in the group of cases with latent mastitis (from 3% in SPI to 30% in PEN), it increased in KAN (13%) and COT (12%) only . Resistance also decreased in bulk samples of sheep milk; it was the highest in PEN (27%) and AMP (17%) and the lowest in CEF, RIF and SPI (5%) . Sheep lumpy cheese and bryndza cheese are mostly made from unpasteurized milk . Resistance continued to decrease even in these dairy products . It ranged from 2% in CEF to 16% in OXA in sheep lumpy sugar, while it varied from 0% in SPI to 14% in TET in bryndza cheese . The results demonstrate that sheep milk and products made from it are not any important sources of antibiotic resistance of S . aureus in Central Slovakia.

Arch Pharm (Weinheim), 1996 Aug-Sep, 329(8-9), 427 - 30
Synthesis and antimicrobial properties of new 4-(alkylidene/arylidene)- amino-5-(2-furanyl)-2,4-dihydro-3H-1,2,4-triazole-3-thiones and 6-aryl-3-(2-furanyl)-7H-1,2,4-triazolo{3,4-b}{1,3,4}thiadiazines; Ergenc N et al.; A series of 4-(alkylidene/arylidene)amino-5-(2-furanyl)-2,4-dihydro- 3H-1,2,4-triazole-3-thiones (2) and 6-aryl-3-(2-furanyl)-7H-1,2,4-triazolo{3,4-b}{1,3,4}thiadiazines (3) were synthesized . The configuration of 2g was assigned on the basis of 1H-NMR data . Of the new derivatives tested, only 2b, 2g, and 4f were found to be active against Staphylococcus aureus and/or Staphylococcus epidermidis (MIC 125-1.95 micrograms/ml), whereas all exhibited varying degrees of antifungal activity (MIC 25-0.8 micrograms/ml).

Pathology, 1996 Aug, 28(3), 259 - 61
Rapid genotypic confirmation of methicillin resistance; Inglis TJ et al.; Detection of phenotypic methicillin resistance in Staphylococcus aureus clinical strains by conventional disk diffusion testing is fraught with problems . We used gene amplification of the mecA locus by polymerase chain reaction (PCR), in conjunction with a capillary/air thermal cycler, to overcome both the inaccuracy of phenotypic methods and the lengthy processing times required for previous genotypic methods . The rapid PCR method correctly identified methicillin resistance in a consecutive series of 30 S . aureus isolates when compared with routine and reference phenotypic methods . The shorter processing time and smaller reagent volumes required for the air thermal cycler make same-day determination of methicillin resistance in clinical isolates feasible for diagnostic laboratories.

Zentralbl Bakteriol, 1996 Aug, 284(4), 516 - 39
Quantitative analysis of multivariate data using artificial neural networks: a tutorial review and applications to the deconvolution of pyrolysis mass spectra; Goodacre R et al.; The implementation of artificial neural networks (ANNs) to the analysis of multivariate data is reviewed, with particular reference to the analysis of pyrolysis mass spectra . The need for and benefits of multivariate data analysis are explained followed by a discussion of ANNs and their optimisation . Finally, an example of the use of ANNs for the quantitative deconvolution of the pyrolysis mass spectra of Staphylococcus aureus mixed with Escherichia coli is demonstrated.

Vet Immunol Immunopathol, 1996 Aug, 52(4), 313 - 21
Reactivity of monoclonal antibodies with bovine blood mononuclear cells activated by mitogens and superantigens; Schuberth HJ et al.; Monoclonal antibodies forming seven preliminary clusters in the third ruminant CD workshop (PC15, 16b, 16c, 20b, 26b, 26c and 30) were analysed by flow cytometry upon reaction with in vitro stimulated bovine mononuclear cells . Concanavalin A (Con A), pokeweed mitogen (PWM) and three Staphylococcus aureus enterotoxins (superantigens SEA, SEB and SEC2) were used as stimulating agents . The mAbs in PC15, 16c and 26b reacted uniformly irrespective of the stimulating agent, in contrast to clusters PC16b, 20b, 26c and 30, which could be subgrouped according to differential reaction pattern depending on mitogen or superantigen stimulation . The mAbs CC28 and CACT114A seem to detect an antigen preferably induced by superantigens . MAb GB16A was shown to react strongly with Con A . Depending on the activation antigen, its time course of expression was either the same upon superantigen stimulation as that for mitogen-stimulated cells or slightly delayed.

J Pharm Pharmacol, 1996 Aug, 48(8), 861 - 5
Antibacterial activity of xanthones from guttiferaeous plants against methicillin-resistant Staphylococcus aureus; Iinuma M et al.; Extracts of Garcinia mangostana (Guttiferae) showing inhibitory effects against the growth of S . aureus NIHJ 209p were fractionated according to guidance obtained from bioassay and some of the components with activity against methicillin-resistant Staphylococcus aureus (MRSA) were characterized . One active isolate, alpha-mangostin, a xanthone derivative, had a minimum inhibitory concentration (MIC) of 1.57-12.5 micrograms mL-1 . Other related xanthones were also examined to determine their anti-MRSA activity . Rubraxanthone, which was isolated from Garcinia dioica and has a structure similar to that of alpha-mangostin, had the highest activity against staphylococcal strains (MIC = 0.31-1.25 micrograms mL-1), an activity which was greater than that of the antibiotic vancomycin (3.13-6.25 micrograms mL-1) . The inhibitory effect against strains of MRSA of two of the compounds when used in conjunction with other antibiotics was also studied . The anti-MRSA activity of alpha-mangostin was clearly increased by the presence of vancomycin; this behaviour was not observed for rubraxanthone . The strong in-vitro antibacterial activity of xanthone derivatives against both methicillin-resistant and methicillin-sensitive Staphylococcus aureus suggests the compounds might find wide pharmaceutical use.

J Dairy Sci, 1996 Aug, 79(8), 1347 - 52
Enhancing bactericidal activity of bovine lymphoid cells during the periparturient period; Shafer-Weaver KA et al.; The antibacterial activity of bovine lymphocytes was evaluated following in vitro stimulation with interleukin-2 . Mononuclear cells were isolated from the blood, lymph node, and mammary parenchymal tissue of four lactating and four periparturient dairy cows . These cells were evaluated for antibacterial activity against Staphylococcus aureus following incubation for 48 h with or without interleukin-2 . Cultures stimulated with interleukin-2 had higher bactericidal activity of all three isolated cell populations than did unstimulated cultures, regardless of lactational stage . This observation suggests that this effector function may possibly be activated in vivo and may potentially increase mammary gland resistance to bacterial infections during periods of increased susceptibility . Flow cytometric analysis of the cultured cells revealed that antibacterial effector cells were mainly CD2+ and were depleted of macrophages . Despite shifts in CD4+, CD8+, and gamma delta T lymphocytes during the periparturient period, bactericidal activity was similar among the three cell sources . This similarity suggests that these lymphocyte phenotypes might not be directly responsible for this effector function . Identification of the antibacterial effector phenotype and its mechanism of action may lead to immunoregulatory strategies aimed at enhancing this novel bactericidal function.

Int J Food Microbiol, 1996 Aug, 31(1-3), 231 - 43
Model for the survival of Staphylococcus aureus in nongrowth environments; Whiting RC et al.; A model was developed to estimate the survival times of Staphylococcus aureus in nongrowth environments . A four strain mixture of S . aureus was inoculated into BHI broth that had a lactate buffer with various combinations of pH (3-7) and lactate (0-1%), NaCl (0.5-20%) and NaNO2 (0-200 ppm) and stored at different temperatures (4-42 degrees C) . At appropriate times the survivors were enumerated by sampling and spreading on TSA plates . The survival curves were modeled with two forms of a logistic equation and the D values were determined . Polynomial regression equations were then calculated to predict the effect of the environmental factors on the D values . Survival times were increased with higher pH values, lower temperatures, and lower nitrite and lactate concentrations . Added salt increased survival times until the salt concentrations exceeded that of most foods.

Infect Control Hosp Epidemiol, 1996 Aug, 17(8), 514 - 20
Host-bacteria interactions in foreign body infections; Francois P et al.; Persistent staphylococcal infections are a major medical problem, especially when they occur on implanted materials or intravascular catheters . This review describes some of the recently discovered molecular mechanisms of Staphylococcus aureus attachment to host proteins coating biomedical implants . These interactions involve specific surface proteins, called bacterial adhesins, that recognize specific domains of host proteins deposited on indwelling devices, such as fibronectin, fibrinogen, or fibrin . Elucidation of molecular mechanisms of S aureus adhesion to the different host proteins may lead to the development of specific inhibitors blocking attachment of S aureus, which may decrease the risk of bacterial colonization of indwelling devices.

Infect Control Hosp Epidemiol, 1996 Aug, 17(8), 512 - 3
Methicillin-resistant Staphylococcus aureus control in hospitals: the Dutch experience; Vandenbroucke-Grauls CM; The Netherlands is one of the few countries where methicillin-resistant Staphylococcus aureus (MRSA) still is uncommon . In 1988, the Werkgroep Infectie Preventie (Working Party on Infection Prevention) issued guidelines on the control of MRSA that could be applied nationwide . The mainstay of the guideline is that all patients who carry MRSA are strictly isolated in single rooms . In 1989, a surveillance study was started by the National Institute of Public Health and the Environment . This study showed that approximately 200 new cases of MRSA colonization or infection occur each year . Small outbreaks of MRSA occur occasionally in The Netherlands, but the surveillance data confirm the success of the Dutch policy.

Infect Control Hosp Epidemiol, 1996 Aug, 17(8), 509 - 11
Methicillin-resistant Staphylococcus aureus control in hospitals: the French experience . Association des Pays de la Loire pour l'Eviction des Infections Nosocomiales; Richet H et al.; The first cases of isolation of Staphylococcus aureus resistant to methicillin in France were published in 1962 . However, until recently, very few epidemiological studies or attempts to control the epidemic have been done in France . In this article, we present the results of a prospective study performed during a 3-month period in 27 hospitals of the Region des Pays de la Loire . Among the 94,605 hospitalized patients included in the study, 0.45% (427) developed methicillin-resistant Staphylococcus aureus (MRSA) infections, the incidence rate ranging from 0% to 1.2% . Thirty-four percent of MRSA-infected patients were 80 years old or older, 30% had been transferred from another service and 19% from another hospital, 56% were hospitalized at least once during the previous year, MRSA had been isolated at least once previously in 18% of MRSA-infected patients, 19% died, 16% were transferred to another service and 11% to another hospital, and only 32% were discharged to their homes . A poor compliance to contact isolation precautions was observed in all hospitals: 46% of MRSA-infected patients were hospitalized in a private room; gloves, masks, and gowns were worn for the care of 63.4%, 14%, and 42.5% of MRSA-infected patients, respectively; and handwashing was feasible in the rooms of 52% of the patients.

Infect Control Hosp Epidemiol, 1996 Aug, 17(8), 503 - 8
Methicillin-resistant Staphylococcus aureus epidemiology and control in Belgian hospitals, 1991 to 1995 . Groupement pour le Dépistage, l'Etude et la Prévention des Infections Hospitalières; Struelens MJ et al.; OBJECTIVES: To describe the Belgian methicillin-resistant Staphylococcus aureus (MRSA) surveillance network, the evolution of methods used in Belgian hospitals for MRSA detection and control, and MRSA incidence from 1994 to 1995 . DESIGN, SETTING, AND PARTICIPANTS: Questionnaire surveys; infection control physicians from acute-care hospitals in Belgium . INTERVENTION: Publication of national guidelines for MRSA control in 1993 . RESULTS: The participation rate in surveys ranged from 42% to 57% of hospitals . In 1995, 88% of participants detected MRSA strains by disk diffusion tests, with little improvement in standardization since 1991 . More centers employed the oxacillin agar screen method (27%), automated systems (29%), or a combination of methods (29%) than in 1991 (P < .005) . Between 1991 and 1995, the proportion of hospitals reporting MRSA control measures increased from 68% to 95% (P < .01) . Practices that were used increasingly included patient placement in private room (from 50% to 93%, P < .01) and hand decontamination with antiseptic (from 43% to 87%, P < .01) . The proportion of centers that reported screening MRSA carriers and treating them topically increased two- and threefold, respectively (P < .05) . Surveillance data from 1994 to 1995 showed that MRSA represented a mean of 21.3% of S aureus clinical isolates (range, 1.6% to 62.4%) . The median incidence of nosocomial MRSA acquisition was 2.8 per 1,000 admissions, with a wide range (0 to 13.7 per 1,000 admissions) across hospitals of all sizes . The median incidence decreased over the first three semesters of surveillance in hospitals with continuous participation . CONCLUSION: MRSA detection and control measures have improved in Belgian hospitals after publication of national guidelines . However, MRSA incidence rates show the persistence of nosocomial transmission, with large variations between centers . The national MRSA surveillance network should indicate whether control efforts eventually will curb the problem.

Infect Control Hosp Epidemiol, 1996 Aug, 17(8), 496 - 502
Automatic alerts for methicillin-resistant Staphylococcus aureus surveillance and control: role of a hospital information system; Pittet D et al.; BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is an escalating problem in hospitals worldwide . The hospital reservoir for MRSA includes recognized and unrecognized colonized or infected patients, as well as previously colonized or infected patients readmitted to the hospital . Early and appropriate infection control measures (ICM) are key elements to reduce MRSA transmission and to control the hospital reservoir . OBJECTIVE: To describe the role of an expert system applied to the control of MRSA at a large medical center (1,600 beds) with high endemic rates . METHODS: The University Hospital of Geneva has an extended hospital information system (HIS), DIOGENE, structured with an open distributed architecture . It includes administrative, medical, nursing, and laboratory applications with their relational databases . Among available patient databases, clinical microbiology laboratory and admission-discharge-transfer (ADT) databases are used to generate computer alerts . A laboratory alert (lab alert) is printed daily in the Infection Control Program (ICP) offices, listing all patients with cultures positive for MRSA detected within the preceding 24 hours . Patients might be either newly detected patients colonized or infected with MRSA, or previously recognized MRSA patients having surveillance cultures . The ICP nurses subsequently go to the ward or call the ward personnel to implement ICM . A second alert, the "readmission alert," detects readmission to the hospital of any patient previously colonized or infected with MRSA by periodic queries (q 1 min) to the ADT database . The readmission alert is printed in the ICP offices, but also forwarded with added guidelines to the emergency room . RESULTS: During the first 12 months of application (July 1994 to June 1995), the lab alert detected an average of 4.6 isolates per day, corresponding to 314 hospital admissions (248 patients); the use of this alert saved time for the ICP nurses by improving work organization . There were 438 readmission alerts (1.2 alerts per day) over the study period; of 347 patients screened immediately upon readmission, 114 (33%) were positive for MRSA carriage . Delayed recognition of readmitted MRSA carriers decreased significantly after the implantation of this alert; the proportion of MRSA patients recognized at the time of admission to the hospital increased from 13% in 1993 to 40% in 1995 (P < .001) . CONCLUSIONS: Hospital information system-based alerts can play an important role in the surveillance and early prevention of MRSA transmission, and it can help to recognize patterns of colonization and transmission.

J Chemother, 1996 Aug, 8(4), 290 - 4
Prophylactic administration of amoxicillin and clavulanic acid in pregnant women with premature rupture of the membranes; Tampakoudis P et al.; Seventy-five pregnant women (mean gestational age 32.26 weeks, range 20-36 weeks) with premature rupture of the membranes (PROM) were admitted in our department during 1989 and the first 6 months of 1990 . Amoxicillin and clavulanic acid was initially administered at a dose of 1.2 g i.v . every 8 hours for 3-4 days and was followed by oral administration of 625 mg every 8 hours until labor . Sixty-one patients (mean gestational age 32.6 +/- 2.3 weeks, range 26-36 weeks) achieved an uncomplicated course of their pregnancies with a mean time of 11.4 +/- 5.7 days (range 3-27 days), from rupture to delivery . Fourteen women (mean gestational age 30.8 +/- 5 weeks, range 20-36 weeks) developed chorioamnionitis 3.5 +/- 0.9 days (range 1.4-5.6 days) after the rupture with several degrees of leukocyte infiltration of the membranes, placenta and the umbilical cord . Five women (mean gestational age 23.8 +/- 2.3 weeks, range 20-26 weeks) had complications resulting in fetal/infant death, three of them because of fetal sepsis (Escherichia coli, Pseudomonas aeroginosa, Staphylococcus aureus) . The newborns were followed up 6 months from delivery and had no signs of drug influence . Few side effects were observed with the chief complaints involving the gastrointestinal tract (4%) . No one discontinued the drug . It seems therefore, that the prophylactic administration of amoxicillin and cluvalanic acid in women with PROM is associated with a significant prolongation of pregnancy and with a reduction in the incidence of fetal/maternal infections.

J Chemother, 1996 Aug, 8(4), 251 - 3
Multidrug resistance among methicillin-resistant Staphylococcus aureus in Greece; Tsakris A et al.; A total of 472 strains of Staphylococcus aureus isolated in a university hospital in Thessaloniki, Greece during 1993-1994 were studied; 202 (42.8%) of them were characterized as methicillin-resistant (MRSA) and were mainly recovered from respiratory materials . The minimal inhibitory concentrations (MICs) of methicillin-susceptible (MSSA) and methicillin-resistant strains to 10 alternative antibiotics were also compared . All MRSA isolates were resistant to penicillin and most of them, in contrast to MSSA, exhibited resistance to gentamicin, tobramycin, tetracycline, erythromycin and ciprofloxacin with resistance rates ranging from 89.6% to 59.4% . Also, considerable proportions of MRSA were found resistant to co-trimoxazole (47.0%) and rifampicin (27.7%) . All isolates were sensitive to vancomycin while susceptibility to chloramphenicol was of equal incidence among the examined populations . Overall, MRSA vs . MSSA exhibited a significantly (chi 2; P < 10-8) higher incidence of resistance to 8 out of the 10 antibiotics examined.

Inflamm Res, 1996 Aug, 45(8), 393 - 7
Peptide inhibitor of interleukin-8 (IL-8) reduces staphylococcal enterotoxin-A (SEA) induced neutrophil trafficking to the lung; Miller EJ et al.; Staphylococcal enterotoxin A (SEA) is a superantigen, produced by some strains of Staphylococcus aureus (S . aureus), which can cause a variety of clinical manifestations ranging from food poisoning to shock . SEA can also stimulate human alveolar macrophages to produce interleukin-8 (IL-8), a member of the alpha-chemokine subfamily that activates and is chemotactic for neutrophils . In these studies we showed that in rabbits, intravenous SEA significantly decreased the circulating white blood cell population from a baseline value of 6409 +/- 2027 x 10(3) cells/ml to 1943 +/- 862 x 10(3) cells/ml in 7 h . There was a concommitent increase in IL-8 in the circulating plasma (baseline: 60 +/- 34 pg/ml, 7 h post SEA: 109 +/- 64 pg/ml) . The increase in circulating IL-8 was accompanied by a much greater increase in the IL-8 concentration of the epithelial lining fluid (ELF) where the IL-8 increased from 0.05 +/- 0.08 ng/ml (control) to 13.8 +/- 9.3 ng/ml (SEA treated) . The increase in IL-8 concentration in the alveolar spaces was paralleled by an increase in both the percentage of neutrophils (1.4 +/- 0.9% (control) to 26.0 +/- 10.8% (SEA treated)) and total number of neutrophils (0.04 +/- 0.02 x 10(6)/ml (control) to 4.8 +/- 3.3 10(6)/ml (SEA treated) in the airspaces, and the numbers of neutrophils in the ELF correlated with the IL-8 concentration r = 0.62, p = 0.006) . When antileukinate, a hexapeptide which inhibits the binding of IL-8 to neutrophils, was administered to animals receiving SEA, the IL-8 concentration in the ELF (14.8 +/- 10.7 ng/ml) was not significantly different from the concentration of IL-8 in those animals receiving SEA alone) . However, both the percentage of neutrophils (9.5 +/- 3.2%), and the total number of neutrophils (1.3 +/- 1.0 x 10(6)/ml) in the ELF following SEA and antileukinate administration was significantly lower than in animals which only received SEA (p < 0.05) . The findings suggest that SEA released into the circulation during a Staphylococcal infection can cause an inflammatory reaction in the lung . Since this reaction is at least partially mediated by IL-8, antileukinate may have pharmacologic potential in reducing the inflammatory reaction.

Inflamm Res, 1996 Aug, 45(8), 386 - 92
Interleukin-8 (IL-8) is a major neutrophil chemotaxin from human alveolar macrophages stimulated with staphylococcal enterotoxin A (SEA); Miller EJ et al.; Since Staphylococcus aureus is an important human pathogen, and infection of the lungs is characterized by neutrophil infiltration we studied the role of a staphylococcal toxin, enterotoxin A (SEA) on the synthesis and secretion of IL-8 by human alveolar macrophages . As SEA concentration was increased, the IL-8 accumulation in the macrophage conditioned medium increased . The concentration of mRNA encoding IL-8 was also elevated in the macrophage in response to increases in SEA concentration . Although the monocytic cell line U937 was able to respond to SEA and secrete IL-8, treatment with PMA prior to SEA stimulation increased the IL-8 accumulation around fifty fold indicating that maturation of the undifferentiated cell to a more macrophage-like cell facilitated IL-8 accumulation . Stimulating human alveolar macrophages with high concentrations of SEA caused an increase in IL-1 accumulation . However, when the cells were incubated with SEA in the presence of IL-1 receptor antagonist, there was no decrease in IL-8 accumulation . Addition of a neutralizing anti-IL-8 monoclonal antibody to the culture medium of SEA-stimulated macrophages significantly reduced the neutrophil chemotactic activity of the medium . These studies showed that IL-8 is a major neutrophil chemotaxin from human alveolar macrophages stimulated with SEA.

Inflammation, 1996 Aug, 20(4), 439 - 50
Activation of phospholipase D is an early event in integrin-mediated signalling leading to phagocytosis in human neutrophils; Serrander L et al.; Integrin receptors on human neutrophils mediate adhesion and phagocytosis . These functions are linked to a signal-transduction cascade that rearranges the cytoskeleton . The intention of this study was to clarify how activation of phospholipase D (PLD) is coupled to the complement receptor three (CR3, CD18/CD11b)-mediated ingestion process . Carbobenzyloxy-leucine-tyrosine-choloromethylketone (zLYCK) inhibited PLD activation induced by complement-opsonized yeast particles (COYP) by 39% . Phagocytosis of these particles was reduced by zLYCK to the same extent . Anti-CD18-antibodies bound to protein A-positive Staphylococcus aureus bacteria induced a significant PLD activation . These particles were not ingested which implicates that CR-mediated ingestion per se is not required to induce PLD activity . Cytochalasin B-treatment, which blocks actin reorganization, partly reduced COYP-mediated PLD activity, but had no effect on activity caused by anti-CD18-coated particles . This excludes activation of PLD to be a secondary event, but rather an early signal in the phagocytic uptake prior to actin reorganization . These data suggest an important and early role for PLD in integrin-mediated phagocytosis.

Immunopharmacol Immunotoxicol, 1996 Aug, 18(3), 397 - 419
Evaluation of interleukin-1 receptor antagonist (IL-1RA) and tumor necrosis factor binding protein (TNF-BP) in a rodent abscess model of host resistance; Colagiovanni DB et al.; Modulation of pro-inflammatory cytokine responses can alter the normal protective mechanisms against invading pathogens . The cytokines interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha) are crucial in the inflammatory cascade for upregulation of adhesion molecule expression, neutrophil recruitment, and additional cytokine induction . To determine if the cytokine antagonists interleukin-1 receptor antagonist (IL-1ra) and tumor necrosis factor-binding protein (TNF-bp) alter host resistance mechanisms they were evaluated in a rodent abscess model . It has previously been shown that subcutaneous Staphylococcus aureus injections induce abscess formation in rats . These abscesses can be examined over a pre-determined time course for evaluation of size, severity and time to resolution . Treatment with immunosuppressive drug therapy can modify the normal course of abscess formation and/or resolution . IL-1ra and TNF-bp were administered either alone or in combination . Also, the effects of these cytokine antagonists in combination with dexamethasone were tested . Results indicated TNF-bp at any dose examined did not adversely alter any parameter of abscess formation or resolution . In contrast, high doses of IL-1ra increased abscess severity, while more clinically relevant doses did not . Combination treatment with IL-1ra and TNF-bp did not alter abscess parameters above individual findings . Dexamethasone, given in combination with either cytokine antagonist, significantly increased severity grading scores above dexamethasone given alone . Overall the data indicated high dosing regimens of IL-1ra or TNF-bp only caused transient impacts on this host resistance model, while more clinically relevant doses did not impact any aspect of the abscess . These findings demonstrate that these anti-cytokine therapies do not alter general host resistance.

Mol Microbiol, 1996 Aug, 21(3), 491 - 500
In vivo immobilization of enzymatically active polypeptides on the cell surface of Staphylococcus carnosus; Strauss A et al.; Many surface proteins of Gram-positive bacteria are covalently anchored to the cell wall by a ubiquitous mechanism, involving a specific, C-terminal sorting signal . To achieve cell-wall immobilization of a normally secreted enzyme in vivo, we constructed a hybrid protein consisting of Staphylococcus hyicus lipase and the C-terminal region of Staphylococcus aureus fibronectin binding protein B (FnBPB) . This region comprised the authentic cell-wall-spanning region and cell-wall sorting signal of FnBPB . Expression of the hybrid protein in Staphylococcus carnosus resulted in efficient cell-wall anchoring of enzymatically active lipase . The cell-wall-immobilized lipase (approximately 10,000 molecules per cell) retained more than 80% of the specific activity, compared to the C-terminally unmodified S . hyicus lipase secreted by S.carnosus cells . After releasing the hybrid protein from the cell wall by lysostaphin treatment . Its specific activity was indistinguishable from that of the unmodified lipase . Thus, the C-terminal region of FnBPB per se was fully compatible with folding of the lipase to an active conformation . To study the Influence of the distance between the cell-wall sorting signal and the C-terminus of the lipase on the activity of the immobilized lipase, the length of this spacer region was varied . Reduction of the spacer length gradually reduced the activity of the surface-immobilized lipase . On the other hand, elongation of this spacer did not stimulate the activity of the immobilized lipase, indicating that the spacer must exceed a critical length of approx . 90 amino acids to allow efficient folding of the enzyme, which probably can only be achieved outside the peptidoglycan web of the cell wall . When the lipase was replaced by another enzyme, the Escherichia coli beta-lactamase, the resulting hybrid was also efficiently anchored in an active conformation to the cell wall of S . carnosus . These results demonstrate that it is possible to immobilize normality soluble enzymes on the cell wall of S . carnosus-without radically altering their catalytic activity-by fusing them to a cell-wall-immobilization unit, consisting of a suitable cell-wall-spanning region and a standard cell-wall sorting signal.

Skeletal Radiol, 1996 Aug, 25(6), 576 - 9
Tropical pyomyositis: imaging findings and a review of the literature; Pretorius ES et al.; Tropical pyomyositis is a rare cause of multiple abscesses of skeletal muscle . The entity is rare in temperate climates and, as its name suggests, is more common in areas such as the tropics and South Pacific . Staphylococcus aureus is the most common cause of infection . Therapy is aggressive, with surgical debridement and drainage followed by antibiotics . We report an unusual case of tropical myositis which simulated tumor recurrence in a patient without the typical risk factors associated with tropical pyomyositis.

J Hosp Infect, 1996 Aug, 33(4), 289 - 300
Staphylococcus aureus carriage and infections among patients in four haemo- and peritoneal-dialysis centres in Denmark . The Danish Study Group of Peritonitis in Dialysis (DASPID); Zimakoff J et al.; A three-month prospective surveillance study was undertaken in four dialysis centres to establish the prevalence of Staphylococcus aureus carriage in a Danish population of patients on haemodialysis (HD) or on continuous ambulatory peritoneal dialysis (CAPD) . General data such as sex, age, diagnosis, number of months in dialysis, hospital and ward were registered on a precoded form . Standardized nose and four skin swabs (axillae, groins, perineum) were performed on the first day of the survey . After one and two months, nose swabs were collected . Infections were registered and cultures were sent for phage-typing together with the S . aureus strains isolated from the swabs; 59.5% of HD patients and 51.2% of CAPD patients carried S . aureus . Permanent carriage was most frequent (P < 0.00009), primarily in the nose (44.0 and 34.9%, respectively in HD and CAPD) . Skin carriage alone was rare (2.4 and 4.7%) . Approximately one third (36.6 and 40.7%) of infections were caused by S . aureus . Although diabetics were not significantly more frequent carriers (60.5%) than non-diabetics (55.0%), the incidence of infection was much higher (26.3% vs . 10.3%, P = 0.004) . In CAPD, peritonitis and tunnel/exit-site infections predominated (81.4%), often caused by S . aureus (34.8%) . More than two thirds of the infections in HD patients were related to intravascular catheterization . The most serious infection was septicaemia, in all cases due to S . aureus . S aureus infections occurred significantly more frequently among carriers (P = 0.005), and more than half the patients were infected by the same or possibly the same strain as they carried in the nose or on skin . Different regimens for the elimination of S . aureus carriage in dialysis patients are discussed . A policy for risk assessment of patients should be developed, and the elimination of S . aureus carriage before dialysis should be encouraged . Controlled trials comparing the cost-effectiveness of recommended regimens to eliminate carriage in HD/CAPD patients are needed . Nose swabs are reliable indicators of carriage in dialysis patients.

J Dairy Res, 1996 Aug, 63(3), 369 - 75
Relationship between thickness, chapping and Staphylococcus aureus colonization of bovine teat tissue; Fox LK et al.; Post-milking measurements of teat skin chapping score, teat thickness and colonization by Staphylococcus aureus were determined for 11.5 d . Three teats on each of twelve Holstein cows, free from Staph . aureus intramammary infections, were immersed in 1 M-NaOH solution to induce teat chapping; the fourth teat served as a control . To achieve different degrees of chapping, one teat per cow received one immersion after each milking for three consecutive milking periods, a second teat received two immersions, and the third teat received one immersion which coincided with the last immersion of the other two teats . All teats were challenged twice with a skim milk broth culture of Staph . aureus (5 x 10(6) cfu) after the first and second milking following NaOH treatment . Measures were initiated with the milking following the last Staph . aureus challenges . Tissue thickness of the lateral side of the teat (barrel) and colonization by Staph . aureus declined with time . Thickness of the teat end varied more erratically . Teat skin chapping score was positively correlated (P < 0.001) with tissue thickness of the barrel and Staph . aureus colonization . Thickness of the barrel was not significantly correlated with Staph . aureus colonization . Barrel thickness as a covariate had a significant effect (P < 0.05) on teat skin colonization of Staph . aureus, whereas teat skin score and teat end thickness had no significant effect . Thus, thickness of the lateral side of the teat explained the greatest variation in Staph . aureus teat skin colonization in the model tested.

Pediatr Emerg Care, 1996 Aug, 12(4), 288 - 90
Staphylococcal tracheitis, pneumonia, and adult respiratory distress syndrome; Horowitz IN; A child initially seen in the emergency department with respiratory distress was diagnosed with viral laryngotracheitis and discharged home on oral steroids . She returned the following day without abatement of her symptoms and was admitted with upper airway obstruction and pneumonia . Bacterial tracheitis was diagnosed when the tracheal aspirate grew a pure culture of Staphylococcus aureus . Hemodynamic instability and severe parenchymal lung disease ensued from septic shock and adult respiratory distress syndrome requiring inotropic support and assisted ventilation . Oscillatory ventilation was instituted when the patient failed conventional ventilation.

New Horiz, 1996 Aug, 4(3), 353 - 60
Problems with resistance in pediatric intensive care; Toltzis P et al.; Antibiotic resistance in the neonatal and pediatric intensive care environments has not been rigorously investigated . There is reason to believe that the epidemiology of antibiotic resistance in these settings may be different from that in other hospital settings because the patients' preadmission health status, the maturity of their immune systems, and their outpatient exposure to antibiotics are different from those seen in adults . At the present time, the areas of greatest concern are the outbreaks of infection caused by methicillin-resistant Staphylococcus aureus in the neonatal ICUs and the emergence of antibiotic-resistant Gram-negative bacteria in pediatric intensive care units (PICU) . In the former, colonization and transmission by nursery personnel remains one of the great challenges in infection control . In the latter, new information is emerging which challenges the notion that antibiotic-restriction policies might be an effective means for modulating the emergence of antibiotic-resistant Gram-negative pathogens in the pediatric intensive care environment . It appears that these organisms are largely imported into the ICU from the community and are not a result of antibiotic practices within the unit itself . This observation requires that strategies to control these organisms in the PICU be reassessed.

J Dermatol, 1996 Aug, 23(8), 539 - 44
Leukemoid reaction in epidermal squamous cell carcinoma; Kiyosawa T et al.; There have been no previous concrete reports of leukemoid reactions associated with squamous cell carcinoma originating in cutaneous tissue . Here we report a case of epidermal squamous cell carcinoma of the sacral region and an associated leukemoid reaction . The tumor invaded deeply and destroyed both the sacrum and coccyx . The white blood cell count was greater than 20,000/mm3 . After resection of the tumor, white blood cells transiently decreased, but did not fall under 10,000/mm3 . Post-operative infection by methicillin-resistant Staphylococcus aureus and Bacteroides caccae caused sepsis and further elevation of the leukocytes to greater than 50,000/mm3 . The leukemoid reaction in the case appeared to have been caused initially by direct invasion of bone by epidermal squamous cell carcinoma and later by severe infection.

Antimicrob Agents Chemother, 1996 Aug, 40(8), 1881 - 8
Quinolone resistance mutations in topoisomerase IV: relationship to the flqA locus and genetic evidence that topoisomerase IV is the primary target and DNA gyrase is the secondary target of fluoroquinolones in Staphylococcus aureus; Ng EY et al.; Mutations in the flqA (formerly ofx/cfx) resistance locus of Staphylococcus aureus were previously shown to be common after first-step selections for resistance to ciprofloxacin and ofloxacin and to map on the S . aureus chromosome distinctly from gyrA, gyrB, and norA.grlA and grlB, the genes for the topoisomerase IV of S . aureus, were identified from a genomic lambda library on a common KpnI fragment, and grlB hybridized specifically with the chromosomal SmaI A fragment, which contains the flqA locus . Amplification of grlA sequences (codons 1 to 251) by PCRs from nine independent single-step flqA mutants, one multistep mutant, and the parent strain identified mutations encoding a change from Ser to Phe at position 80 in four mutants, a novel change from Ala to either Glu or Pro at position 116 in three mutants, and no change in three mutants . In the multistep mutant, another resistance locus, flqC, was mapped by transformation to the chromosomal SmaI G fragment by linkage to omega(ch::Tn551)1051 (58%) and nov (97.9%), which encodes resistance to novobiocin . This fragment contains the gyrA gene, and flqC mutants had a mutation in gyrA encoding a change from Ser to Leu at position 84, a change previously found in resistant clinical isolates . In genetic outcrosses, the flqC (gyrA) mutation expressed resistance only in flqA mutants, including those with both types of grla mutations . The silent mutant allele of gyrA was present in a flqA background and expressed resistance only upon introduction of a grlA mutation . At fourfold the MIC of ciprofloxacin, the bactericidal activity of ciprofloxacin was reduced in a grlA mutant and was abolished in gyrA grlA double mutants . These findings provide direct genetic evidence that topoisomerase IV is the primary target of current fluoroquinolones in S . aureus and that this effect may result from the greater sensitivity of topoisomerase IV relative to that of DNA gyrase to these agents . Furthermore, resistance from an altered DNA gyrase requires resistant topoisomerase IV for its expression.

Antimicrob Agents Chemother, 1996 Aug, 40(8), 1870 - 4
Uptake of cefepime by phagocytosing polymorphonuclear neutrophils and subsequent intracellular killing; Pruul H et al.; Studies of the uptake of beta-lactam antibiotics indicate that they do not accumulate in phagocytic cells . Uptake of beta-lactams is thought to occur through passive diffusion, and this is limited because of their acidic nature . Many studies of antibiotic uptake have utilized either resting phagocytic cells or cells in their postphagocytic phase . We have examined the uptake of cefepime by actively phagocytosing neutrophils under various conditions of neutrophil stimulation in order to determine cefepime intracellular activity against Escherichia coli and Staphylococcus aureus . Exposure of cefepime increased bactericidal activity against E . coli both when bacteria were added during exposure to the antibiotic and when they were added to the neutrophils in the postantibiotic phase . Antibacterial activity was only partially inhibited by phenylbutazone, and an exposure of 4 min to cefepime is sufficient for optimal intracellular activity . Under the same conditions, cefepime-associated killing of S . aureus was not as great as was observed for E . coli . Quantitation of intracellular cefepime showed that neutrophil activation in opsonizing conditions increased the antibiotic concentration by 75 (E . coli) and 55% (S . aureus) . The response of neutrophils to the combination of serum, E . coli, and cefepime indicates a significant increase in the chemiluminescence response, compared with the response obtained with bacteria in the absence of cefepime . These data indicate that cefepime rapidly enters phagocytic cells under opsonizing conditions with concomitant increases in oxidative metabolism and intracellular activity against E . coli.

Antimicrob Agents Chemother, 1996 Aug, 40(8), 1835 - 42
Hydrophilicity of quinolones is not an exclusive factor for decreased activity in efflux-mediated resistant mutants of Staphylococcus aureus; Takenouchi T et al.; The elevated expression of the norA gene is responsible for efflux-mediated resistance to quinolones in Staphylococcus aureus (E.Y.W . Ng, M . Trucksis, and D.C . Hooper, Antimicrob . Agents Chemother . 38:1345-1355, 1994) . For S . aureus transformed with a plasmid containing the cloned norA gene, SA113(pTUS20) (H . Yoshida, M . Bogaki, S . Nakamura, K . Ubukata, and M . Konno, J . Bacteriol . 172:6942-6949, 1990), and an overexpressed mutant, SA-1199B (G.W . Kaatz, S.M . Seo, and C.A . Ruble, J . Infect . Dis . 163:1080-1086, 1991), the MICs of norfloxacin increased 16 and 64 times compared with its MICs for the recipient and wild-type strains, SA113 and SA-1199, respectively . MICs of CS-940, however, increased only two and eight times, even though these two fluoroquinolones are similarly hydrophilic (apparent logPs of approximately -1) . No good correlation was found, among 15 developed and developing quinolones, between the increment ratio in MICs and hydrophobicity (r = 0.61) . Analysis of the quantitative structure-activity relationship among 40 fluoroquinolones revealed that the MIC increment ratio was significantly correlated with the bulkiness of the C-7 substituent and bulkiness and hydrophobicity of the C-8 substituent of fluoroquinolones (r = 0.87) and not with its molecular hydrophobicity (r = 0.47) . Cellular accumulation of norfloxacin in SA-1199B was significantly lower than that in SA-1199, and it was increased by addition of carbonyl cyanide m-chlorophenyl hydrazone . On the other hand, accumulations of CS-940 in these strains were nearly identical, and they were not affected by addition of the protonophore.

Clin Infect Dis, 1996 Aug, 23(2), 255 - 9
Nosocomial and community-acquired Staphylococcus aureus bacteremias from 1980 to 1993: impact of intravascular devices and methicillin resistance; Steinberg JP et al.; The rate of nosocomial bacteremia due to Staphylococcus aureus has increased over the past decade, but trends in community-acquired S . aureus bacteremia are less certain . This hospital-based observational study compares nosocomial and community-acquired S . aureus bacteremias during 1980-1983 and 1990-1993 . The rate of nosocomial S . aureus bacteremia increased from 0.75 to 2.80 cases per 1,000 discharges, while the rate of community-acquired S . aureus bacteremia increased from 0.84 to 2.43 cases per 1,000 discharges . The number of nosocomial device-related bacteremias increased eightfold; 56% of S . aureus bacteremias were associated with devices during 1990-1993 . Intravascular devices were associated with no community-acquired S . aureus bacteremias during 1980-1983 but with 22% during 1990-1993 . Methicillin-resistant S . aureus (MRSA) seldom caused bacteremia during 1980-1983 . From 1990 to 1993, MRSA caused 32% and 18.5% of nosocomial and community-acquired S . aureus bacteremias, respectively . The rates of both community-acquired and nosocomial S . aureus bacteremias have increased significantly since 1980 . In addition to their role in nosocomial infections, MRSA and intravascular device-related S . aureus bacteremias are emerging problems in the nonhospital setting.

Acta Paediatr Jpn, 1996 Aug, 38(4), 339 - 42
Periorbital cellulitis: a comparison of different treatment regimens; Kanra G et al.; Periorbital cellulitis was retrospectively investigated in a cohort of 69 children, 1.5-16 years of age, who were admitted to Hacettepe University Children's Hospital . The aim of the study was to define the most important cause of the disease and to choose the most appropriate antimicrobial regimen . Sinusitis (43%) was found to be the most frequent disease associated with periorbital cellulitis . Trauma (25%) and odontogenic infections (6%) were the next most common predisposing causes . Staphylococcus aureus was isolated from 14 (74%) of 19 cultures . Two antibiotic combinations, penicillin plus chloramphenicol and sulbactam-ampicillin (SAM) with or without ornidazole was used in 30 (43%) and 39 (57%) of 69 cases, respectively . The duration of treatment with these two antibiotic combinations was generally between 7 and 10 days . No statistical difference was found between the two antibiotic combinations in the cure and recurrence rates but five (17%) of the 30 cases using penicillin plus chloramphenicol, and one (3%) of the 39 cases using SAM with or without ornidazole had recurrent periorbital cellulitis . It was concluded that SAM can be the first line of drug treatment for periorbital cellulitis as it is easily used in every age group and etiology (trauma, sinusitis, etc.) . It provides total recovery and has less side effects and risk of recurrence . It also has a broad antimicrobial spectrum.

Kidney Int, 1996 Aug, 50(2), 643 - 52
Disturbed host defense in peritoneal cavity during CAPD: characterization of responsible factors in dwell fluid; Vanholder R et al.; In this study, the factors in overnight dwell fluid (8 to 10 hr dwell) depressing granulocyte (GC) NAD(P)H-oxidase dependent radical species production are characterized . At present, most studies have essentially focused on fresh, unspent dialysate and on peritoneal macrophages . The response to Staphylococcus aureus (Staph A) was dose-dependently depressed for both GC CO2 production (from 91.3 +/- 8.4 to 9.0 +/- 1.5 dpm/10(3) GC, P < 0.01) and chemiluminescence (CL) (peak from 7.3 +/- 0.8 to 1.6 +/- 0.8 cps x 10(3)/GC, P < 0.01) . Stimulation with formyl-methionine-leucine-phenylalanine (f-MLP), phorbol myristic acid (PMA), Staphylococcus epidermidis (Staph Epi), E . coli, latex and zymosan revealed a parallel depression, pointing to an intrinsic metabolic defect, rather than failure of particle ingestion . The addition of glucose to the normal cell medium to obtain the same concentration as in the CAPD effluent (2.9 +/- 0.3 mg/dl) depressed function but not to the same extent as the genuine PD effluent . Opsonization of Staph A and E . coli induced a partial correction . No effect of pH or osmolality was observed . HPLC fractionation of CAPD effluent on a polarity based gradient revealed an elution of depressive factors in hydrophobic fractions with a nadir in F7 and F12 . Analysis of the elution pattern of various uremic solutes revealed elution in F12 of p-cresol, a solute with known inhibitory effect on GC function . These events may be related to recent peritonitis (CL in response to Staph A 0.3 +/- 0.1 in effluent of 6 patients with recent peritonitis versus 2.6 +/- 0.8 cps x 10(3)/GC in 12 patients without recent peritonitis (P < 0.01) . We conclude that the GC response is depressed in the presence of CAPD effluent due to excess glucose, lack of opsonization, and uremic solutes of which p-cresol is one of the responsible compounds.

Burns, 1996 Aug, 22(5), 384 - 9
A comparison of phenotypic properties of Staphylococcus aureus isolated from burned children and other patient groups; Edwards-Jones V et al.; This study aimed to determine whether strains of Staph . aureus isolated from children on our paediatric burns unit were different from strains isolated from other patient groups . Of particular interest was the incidence of toxin production amongst the different patient groups and the potential association with toxic shock syndrome (TSS) . Wound isolates of Staph . aureus were collected from three patient groups: (1) hospital inpatients, (2) community patients and (3) patients from a regional burns unit . One hundred isolates were collected from each group (n = 300) . Each isolate was tested for enterotoxin and TSST-1 production, phage type, antibiogram and tryptophan dependence . The results were compared, to determine whether there were any differences between the isolates from each of these patient groups . There were some variations in antibiotic sensitivity patterns and phage type of the isolates between the different patient groups but there was no significant difference in the incidence of toxin production, which was an important observation . The 100 isolates collected from this burns unit were derived from 58 patients . The colonization patterns of the Staph . aureus showed that 12 patients were colonized by more than one isolate and that these were a mixture of toxin-positive and toxin-negative strains . The medical records were examined for evidence of TSS; there was a higher incidence of toxic episodes in the patients colonized with strains which produced TSST-1 toxin.

Neth J Med, 1996 Aug, 49(2), 86 - 9
Tropical pyomyositis in a temperate climate: a case report; Simmers TA et al.; Pyomyositis is an abscess-forming infection of large skeletal muscles, usually with Staphylococcus aureus . Although it is common in the tropics and relatively rare in temperate climates, imported cases due to growing global mobility may be expected to increase its incidence outside tropical regions . Early diagnosis and correct management are imperative in this potentially fatal disorder, and require a high degree of clinical suspicion . A case report is presented demonstrating typical aspects of diagnosis and treatment.

J Surg Res, 1996 Aug, 64(2), 116 - 9
The biologic role of B2 integrins in the host response to expanded polytetrafluoroethylene; Benton LD et al.; We hypothesized that the adherence of leukocytes to a vascular graft surface is mediated by B2 integrins . We studied integrin expression and monoclonal antibody inhibition of peripheral blood leukocyte (PBL) binding in vitro and CD11b expression in vivo . Human PBL were grown on ePTFE in culture and labeled with monoclonal antibodies to CD11a, -b, -c, and/or CD18 . Percentage of monoclonal antibody binding and inhibition of leukocyte adherence was studied for up to 30 min using flow cytometry . ePTFE segments were implanted subcutaneously in SH-1 mice and PBL harvested 4 days later . PBL binding of monoclonal antibodies against CD11b was measured using flow cytometry . CD18 was constitutively expressed and CD11a decreased over time . CD11b increased from 41 to 62% and CD11c increased transiently (P < 0.003, P < 0.005) . Inhibiton of PBL adherence was greatest by CD11b (34%) and CD11b + CD18 (57%) (P < 0.005, P < 0.0025) . Implanted ePTFE caused a fourfold increase in PBL monoclonal antibody binding of CD11b (P < 0.001) compared to sham, Staphylococcus aureus alone, and combination of ePTFE and S . aureus . In conclusion, leukocyte integrins play a central role in the interaction between PBLs and ePTFE as measured by binding of monoclonal antibodies and inhibition of PBL adherence . This is also true in vivo since PBL increase CD11b expression four times when ePTFE is compared to sham . These observations indicate a potential role in vivo for B2 integrins in vascular prosthetic infections.

Am J Surg, 1996 Aug, 172(2), 151 - 4
Infection of endovascular stents in a swine model; Thibodeaux LC et al.; BACKGROUND: Percutaneous balloon angioplasty with intravascular metallic stent placement has rapidly gained popularity for the treatment of arterial occlusive disease . Although the incidence of vascular prosthetic infection is well described, the risk of infection following metallic stent placement is unknown . The purpose of this study was to determine if intravascular metallic stents could become infected following systemic bacterial challenge . METHODS: Balloon expandable metallic stents were implanted in the iliac arteries of 10 swine following balloon catheter angioplasty . A second angioplasty, without stent placement, was also performed in the contralateral iliac artery . A bacterial challenge with Staphylococcus aureus was then infused into the aorta immediately after stent placement . Group 1 (n = 5) was killed at 72 hours, and group 2 (n = 5) at 3 weeks . A third group (n = 5) underwent stent placement without bacterial challenge and was killed at 3 weeks . At the time of death, the stents were cultured, and both iliac arteries were submitted for pathologic examination . Arterial patency and evidence of systemic infection were also assessed . RESULTS: In the animals sacrificed at 72 hours (group 1), 80% had stent cultures with significant growth of S aureus; while at 3 weeks (group 2), 60% of cultures were positive . Of the stents placed without bacterial challenge (group 3), none had a positive culture at 3 weeks . In group 2, 40% of the stented arteries remained patent, while 100% of group 3 remained patent until sacrifice at 3 weeks . All of the stented arteries which were patent at 3 weeks were culture negative, while all those which were thrombosed were culture positive for S aureus . When compared to angioplasty alone, the presence of a stent was strongly associated with pathologic evidence of inflammation {93% versus 7%} . The quality of inflammation in the stented groups also differed . Ninety percent of the stented arteries in groups 1 and 2 had acute inflammation, compared to only 20% in group 3 . The remainder of the stented arteries in group 3 had chronic inflammation or were normal . CONCLUSION: In the swine model, intravascular metallic stents have the potential to become infected . This is associated with acute inflammation of the arterial wall and vessel thrombosis . Further studies evaluating the incidence of stent infections in humans are needed.

Eur J Biochem, 1996 Aug 1, 239(3), 752 - 8
Receptor-induced translocation of activated guanine-nucleotide-binding protein alpha i subunits to the cytoskeleton in myeloid differentiated human leukemia (HL-60) cells; Wieland T et al.; The regulation of the cytoskeletal localization of guanine-nucleotide-binding protein alpha i subunits by formyl peptide receptors was studied in myeloid differentiated human leukemia (HL-60) cells . Stimulation of formyl peptide receptors with N-formyl-Met-Leu-Phe (fMet-Leu-Phe) transiently increased the amount of alpha i subunits in the Triton X-100-insoluble cytoskeleton . Similar to the biphasic regulation of the actin content, fMet-Leu-Phe ( > or = 10 nM) rapidly increased the cytoskeletal alpha i content (about threefold at 30 s), which was followed by a rapid reversal to control levels . The formyl peptide receptor increased the cytoskeletal content of both alpha i subtypes, alpha i2 and alpha i3- present in HL-60 cells . In cells permeabilized with Staphylococcus aureus alpha-toxin, fMet-Leu-Phe increased binding of the stable GTP analogue, guanosine 5'-{gamma-thio}triphosphate (GTP{S}), to cytoskeletal proteins in a pertussis-toxin-sensitive manner, which was completely abolished by the F-actin-disrupting agent, cytochalasin B . Using the photoreactive GTP analogue, m-acetylanilido-GTP, the formyl peptide receptor-regulated GTP binding sites at the cytoskeleton were identified as 40-kDa proteins, the molecular size of alpha i subunits . Cytoskeleton prepared from stimulated cells did not exhibit increased GTP{S} binding, which suggests that activated alpha i subunits are translocated to the cytoskeleton . Finally, in alpha-toxin-permeabilized HL-60 cells, fMet-Leu-Phe and GTP{S} cooperatively stimulated actin polymerization . In conclusion, evidence is provided that chemoattractant receptors cause translocation of activated alpha i subunits to the cytoskeleton coincidentally with F-actin formation . The data therefore argue for a potential role of translocated alpha i subunits in the process of receptor-induced actin polymerization.

Clin Orthop, 1996 Aug, (329), 273 - 80
Persistence of bacteria on antibiotic loaded acrylic depots . A reason for caution; Kendall RW et al.; Bacterial growth on the surface of antibiotic loaded acrylic cement was examined in an in vitro model . Tobramycin or vancomycin impregnated discs were incubated in broth containing either Staphylococcus epidermidis or Staphylococcus aureus organisms . At 24, 48, and 96 hours, the broth and the surface of the acrylic discs were examined for viable organisms . In the broth, only 6% (8 of 136) of samples contained viable organisms at 24 hours, and all samples were sterile by 96 hours . This is in contrast to the surface of the discs, which revealed the presence of viable organisms at all study time periods . Growth was noted in 99% and 30% of the Staphylococcus epidermidis and Staphylococcus aureus discs, respectively, at 24 hours . Viable organisms were found on both types of discs through 96 hours (20% of Staphylococcus epidermidis and 15% of Staphylococcus aureus) . The surface of bone cement is therefore a suitable substrate for bacterial growth, even in the presence of antibiotics . In clinical practice, antibiotic loaded acrylic cement should therefore be used with caution and clear indications.

FEMS Microbiol Lett, 1996 Aug 1, 141(2-3), 255 - 60
Impact of sar and agr on methicillin resistance in Staphylococcus aureus; Piriz Duran S et al.; The global regulators agr and sar control expression of cell wall and extracellular proteins . Inactivation of either sar and/or agr in a typical heterogeneously methicillin-resistant Staphylococcus aureus resulted in a small but reproducible decrease in the number of cells in the subpopulation expressing high methicillin resistance . The amount of low affinity penicillin-binding protein PBP2', the prerequisite for methicillin resistance, was apparently not affected, however, a reduction in PBP1 and PBP3 production was observed, suggesting that these resident PBPs of the cells might be involved somehow together with PBP2' in high level methicillin resistance.

FEMS Microbiol Lett, 1996 Aug 1, 141(2-3), 117 - 27
Iron depletion and virulence in Staphylococcus aureus; Trivier D et al.; Staphylococcus aureus is able to grow in the presence of extremely low iron concentrations (0.04 microM) . In iron-limiting conditions, this species develops alternative metabolic strategies such as highly efficient iron-uptake mechanisms which are only partially shared with S . epidermidis . Here we summarize the mechanisms induced by iron starvation in S . aureus in order to elucidate the virulence characteristics of this bacterium.

Plast Reconstr Surg, 1996 Aug, 98(2), 338 - 45
The effect of infection and lag screw fixation on revascularization and new bone deposition in membranous bone grafts in a rabbit model; Fialkov JA et al.; We have suggested that rigid fixation of membranous bone grafts in the presence of infection may improve graft-recipient bone union by facilitating graft revascularzation . To test this hypothesis, we grafted autogenous membranous bone grafts to the mandibles of 94 New Zealand White rabbits . Lag screw fixation was applied in half the animals . The wounds were inoculated with a range of Staphylococcus aureus doses . Infected and noninfected rabbits were injected weekly over a 5-week course with fluorescein bone markers and with a marker of vascular endothelium (procion red) just prior to sacrifice . Revascularization and new bone deposition in the grafts were then quantified histologically for the 75 rabbits available for data collection . Infection decreased the amount of graft revascularized and the amount of new bone deposited for both rigidly fixated and nonfixated grafts . Grafts fixated with a lag screw showed a greater amount of revascularization and new bone deposition in the presence and absence of infection when compared with nonfixated grafts, supporting the hypothesis that rigid fixation of membranous bone grafts in the presence of infection may promote graft survival and union by improving revascularization and osteogenesis within the graft.

Microbiology, 1996 Aug, 142 ( Pt 8), 2153 - 60
A low-fibronectin-binding mutant of Staphylococcus aureus 879R4S has Tn918 inserted into its single fnb gene; Greene C et al.; A low-fibronectin-binding mutant of Staphylococcus aureus strain 879R4SSp generated by transposon Tn918 mutagenesis is attenuated in a rat endocarditis model (J.M . Kuypers & R.A . Procter, 1989, Infect Immun 57, 2306-2312) . PCR and Southern hybridization analysis with primers and probes, respectively, for the fnbA and fnbB genes of strains 8325-4 showed that strain 879R4SSp possesses a single fnb gene which is homologous to fnbA . This was confirmed by sequencing 41 bp of 5' non-coding and 237 bp of 5' coding DNA, which showed 97% base identity to fnbA . Southern hybridization and sequencing showed that Tn918 was inserted 41 bp 5' to fnbA in the mutant 879R4SSp/1536, between the promoter and initiation codon . Reduced adherence of the mutant to surface-bound fibronectin correlated with lower expression of a 180 kDa wall-associated fibronectin-binding protein.

J Appl Bacteriol, 1996 Aug, 81(2), 191 - 4
Survival of Staphylococcus aureus and enterotoxin A in glassy and rubbery states of gelatin; Bolton KJ et al.; About 1% of Staphylococcus aureus cells survived the production of gelatin sheets containing nutrient broth . Those cells which survived showed no evidence of injury . Growth occurred in rubbery state gelatin with a(w) values of 0.98 and 0.93 ; viability decreased during storage at a(w) values of 0.89, 0.62 and 0.36 but there was little loss of viability in gelatin at an aw of 0.25 over 27 d storage at 26 degrees C . Assays for enterotoxin A detected no synthesis of new toxin but no loss in pre-formed toxin . The results suggest that high levels of Staph . aureus and its toxins should be excluded from glassy and rubbery state food products in order to prevent illness.

Infect Immun, 1996 Aug, 64(8), 3435 - 7
Tumor necrosis factor primes neutrophils to kill Staphylococcus aureus by an oxygen-dependent mechanism and Plasmodium falciparum by an oxygen-independent mechanism; Kowanko IC et al.; The cytokine tumor necrosis factor (TNF) plays the important role of priming neutrophils for increased antimicrobial activity . We now demonstrate that human neutrophils which lack the ability to generate oxygen radicals, from patients with chronic granulomatous disease, show TNF-induced enhancement of killing of intraerythrocytic stages of Plasmodium falciparum but not of Staphylococcus aureus.

Infect Immun, 1996 Aug, 64(8), 3407 - 9
Interleukin-8 gene expression in Staphylococcus aureus-infected endothelial cells; Yao L et al.; Interleukin-8 (IL-8) plays a crucial role in the migration of neutrophils to bacterium-infected sites . This study investigated IL-8 induction in Staphylococcus aureus-infected endothelial cells (EC) . We observed that S . aureus-infected EC were induced to express both IL-8 mRNA and protein, which can promote transmigration of neutrophils across an EC monolayer.

Infect Immun, 1996 Aug, 64(8), 3394 - 6
Sequence of the toxic shock syndrome toxin gene (tstH) borne by strains of Staphylococcus aureus isolated from patients with Kawasaki syndrome; Deresiewicz RL et al.; To explore whether a novel staphylococcal clone or structural variant of toxic shock syndrome toxin 1 is associated with Kawasaki syndrome, six toxigenic strains of Staphylococcus aureus from Kawasaki syndrome patients were studied . The strains were divisible into two groups based on phenotypic and genotypic characteristics and are therefore unequivocally not clonal . Portions of the tstH genes of each strain were sequenced . Three were sequenced in their entirety, while the remainder were sequenced from codon 66 to codon 137 of the mature protein only . Two of the former group differed slightly in the sequences of their signal peptides relative to the sequence published for the tstH signal peptide . Those differences did not affect toxin processing or secretion . The sequenced portions of the regions encoding mature toxic shock syndrome toxin 1 were identical in all six strains and corresponded exactly to the published sequence of tstH . No evidence was found for the existence of a structural variant of tstH uniquely associated with Kawasaki syndrome.

Infect Immun, 1996 Aug, 64(8), 3267 - 72
Proteins of 30 and 36 kilodaltons, membrane constituents of the Staphylococcus aureus L form, induce production of tumor necrosis factor alpha and activate the human immunodeficiency virus type 1 long terminal repeat; Akashi A et al.; We have previously demonstrated that the membrane of the Staphylococcus aureus L form induced tumor necrosis factor alpha (TNF-alpha) from murine macrophages . In this study, we purified two proteins which induce TNF-alpha production from a human monocytic cell line, THP-1, and murine macrophages . These molecules were purified from delipidated membranes by deoxycholic acid extraction, two-step anion-exchange chromatography, and preparative electrophoresis . Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified proteins showed for each a single band with a molecular mass of 30, and 36 kDa . These proteins were heat stable . Polymyxin B did not affect the production of TNF-alpha induced by these proteins . Furthermore, these proteins induced comparable levels of TNF-alpha in both lipopolysaccharide-responsive and -nonresponsive mouse macrophages . Pretreatment of murine macrophages with gamma interferon enhanced 30- and 36-kDa protein-mediated TNF-alpha production . The 30-kDa protein showed lethal toxicity to D-galactosamine-treated mice . The 30- and 36-kDa proteins stimulated the human immunodeficiency virus type 1 long terminal repeat in a monocytic cell line but not a T-cell line . This effect appeared to be mediated through the induction of nuclear factor kappaB . These results indicate that the 30- and 36-kDa proteins, membrane constituents of the S . aureus L form, may play a role in S . aureus infection and/or in human immunodeficiency virus type 1-infected individuals.

Infect Immun, 1996 Aug, 64(8), 3142 - 7
Influence of agr on fibrinogen binding in Staphylococcus aureus Newman; Wolz C et al.; The ability of Staphylococcus aureus to bind fibrinogen is believed to be important in promoting bacterial adherence to both intravascular catheters and host tissues during infection . We investigated the influence of the global regulator agr on the fibrinogen binding capacity and its relationship to the expression of coagulase (encoded by coa) and clumping factor (encoded by clfA) in strain Newman . Strains were obtained by transducing site-specific mutations of clfA, coa, and agr into strain Newman to obtain single, double, and triple mutants of the respective genes . As expected, the clfA mutant bound less soluble 125I-labeled fibrinogen than the corresponding coa mutant in agr+ strains; however, with agr mutant strains, the upregulation in fibrinogen binding capacity correlated mostly with the increased expression and transcription of coagulase as shown by Western (immunoblot) and Northern (RNA) blot analysis . In particular, the coa agr double mutant resulted in a significant reduction in fibrinogen binding compared with that of the agr mutant . The contribution of clfA to fibrinogen binding in agr-negative strains was less than that of coa (32,740 +/- 1,189 versus 18,141 +/- 334 and 38,919 +/- 1,021 cpm for clfA agr, coa agr, and the single agr mutant, respectively) . Thus, coagulase is a major binding protein for soluble fibrinogen in the agr-negative background . In in vitro microtiter and catheter adherence assays with solid-phase fibrinogen, clumping factor, but not coagulase, plays a major role in binding to immobilized fibrinogen . coa transcription was negatively modulated by agr and occurred mainly during the exponential growth phase . In contrast, clfA transcription was agr independent and was strongest during the postexponential phase . Although an agr coa clfA triple mutant bound less soluble fibrinogen than the agr coa double mutant (8,504 +/- 831 versus 18,141 +/- 334 cpm), significant residual fibrinogen binding capacity remained in the triple mutant, thus suggesting an additional fibrinogen binding component . By using direct ligand affinity blotting with 125I-fibrinogen, we could identify coagulase and an additional unidentified 52-kDa protein as a fibrinogen binding component in cell extracts . This band was absent in the extract of the coa clfA double mutant.

Infect Immun, 1996 Aug, 64(8), 3007 - 15
Mitogenic activities of amino acid substitution mutants of staphylococcal enterotoxin B in human and mouse lymphocyte cultures; Neill RJ et al.; Site-directed mutagenesis has been used to introduce amino acid substitutions at specific residues of the staphylococcal enterotoxin B (SEB) gene cloned from Staphylococcus aureus 10-275 . The mitogenic activities of these derivatives were determined in two assay systems: (i) mouse spleen cells and (ii) a mixture of human peripheral blood mononuclear cells and lymphocytes . Substitution of either His-12, His-32, His-121, His-166, Lys-152, or Gly-205 did not significantly alter the mitogenic activity from that of the wild-type toxin in either proliferation assay . Substitution of either residue Asn-23, Phe-44, or Cys-93 reduced the mitogenicity of SEB by a degree that depended upon the assay system used . Similar to the results reported by others measuring toxin activation of mouse lymphoid cells, we found that substitutions of these three residues of SEB caused at least 800-fold reductions of mitogenic activity from that of the wild-type toxin . When tested for toxicity in vivo in D-galactosamine-treated mice, the reduced activities of these mutant toxins, however, were not as pronounced . In contrast, when tested in the human cell mitogenicity assay, these mutant toxins were active . Small alterations in activity (two- to fivefold reduction) were observable only at low concentrations . Our findings reveal the importance of using human lymphocytes in addition to the traditional mouse spleen cell assay when assessing biological activities of staphylococcal enterotoxins.

Infect Immun, 1996 Aug, 64(8), 2974 - 9
Selective killing of human monocytes and cytokine release provoked by sphingomyelinase (beta-toxin) of Staphylococcus aureus; Walev I et al.; The best-known activity of Staphylococcus aureus sphingomyelinase C, alias beta-toxin, is as a hemolysin that provokes hot-cold lysis of erythrocytes which contain substantial amounts of sphingomyelin in the plasma membrane . Sheep erythrocytes are most susceptible, and we found that one hemolytic unit, representing the toxin concentration that elicits 50% hemolysis of 2.5 X 10(8) erythrocytes per ml, corresponds to 0.05 enzyme units or to approximately 0.25 microg of sphingomyelinase per ml . The cytotoxic action of beta-toxin on nucleated cells has not been described in any detail before, and the present investigation was undertaken to fill this information gap . We now identify beta-toxin as a remarkably potent monocytocidal agent . At a concentration of 0.001 U/ml, corresponding to approximately 5 ng/ml, beta-toxin killed over 50% of human monocytes (10(6) cells per ml) within 60 min . By contrast, 1 to 5 microg of beta-toxin per ml had no cytocidal effects on human granulocytes, fibroblasts, lymphocytes, or erythrocytes . A selective monocytocidal action was also observed with sphingomyelinase C from Bacillus cereus and a Streptomyces sp., whereas phospholipase A2 and phospholipase D at 100 U/ml were without effect . Monocytes succumbing to the action of beta-toxin processed and released interleukin-1beta, soluble interleukin-6 receptor, and soluble CD14 into the supernatant . Thus, monocyte killing by beta-toxin is associated with cytokine-related events that are important for the initiation and progression of infectious disease . These findings uncover a potentially important role for sphingomyelinase as a determinant of microbial pathogenicity.

J Bacteriol, 1996 Aug, 178(15), 4381 - 91
Isolation of a gene involved in 1,3-beta-glucan synthesis in Aspergillus nidulans and purification of the corresponding protein; Kelly R et al.; Saccharomyces cerevisiae has two highly homologous genes, FKS1 and FKS2, which encode interchangeable putative catalytic subunits of 1,3-beta-glucan synthase (GS), an enzyme that synthesizes an essential polymer of the fungal cell wall . To determine if GS in Aspergillus species is similar, an FKS homolog, fksA, was cloned from Aspergillus nidulans by cross-hybridization, and the corresponding protein was purified . Sequence analysis revealed a 5,716-nucleotide coding region interrupted by two 56-bp introns . The fksA gene encodes a predicted peptide of 229 kDa, FksAp, that shows a remarkable degree of conservation in size, charge, amino acid identity, and predicted membrane topology with the S . cerevisiae FKS proteins (Fksps) . FksAp exhibits 64 and 65% identity to Fks1p and Fks2p, respectively, and 79% similarity . Hydropathy analysis of FksAp suggests an integral membrane protein with 16 transmembrane helices that coincide with the transmembrane helices of the Saccharomyces Fksps . The sizes of the nontransmembrane domains are strikingly similar to those of Fks1p . The region of FksAp most homologous to the Saccharomyces FKS polypeptides is a large hydrophilic domain of 578 amino acids that is predicted to be cytoplasmic . This domain is 86% identical to the corresponding region of Fks1p and is a good candidate for the location of the catalytic site . Antibodies raised against a peptide derived from the FksAp sequence recognize a protein of approximately 200 kDa in crude membranes and detergent-solubilized active extracts . This protein is enriched approximately 300-fold in GS purified by product entrapment . Purified anti-FksAp immunoglobulin G immunodepletes nearly all of the GS activity in crude or purified extracts when Staphylococcus aureus cells are used to precipitate the antibodies, although it does not inhibit enzymatic activity when added to extracts . The purified GS is inhibited by echinocandins with a sensitivity equal to that displayed by whole cells . Thus, the product of fksA is important for the activity of highly purified preparations of GS, either as the catalytic subunit itself or as an associated copurifying subunit that mediates susceptibility of enzymatic activity to echinocandin inhibition.

J Bone Joint Surg Am, 1996 Aug, 78(8), 1201 - 5
Effect of intraoperative blood loss on the serum level of cefazolin in patients managed with total hip arthroplasty . A prospective, controlled study; Meter JJ et al.; The effect of intraoperative blood loss on serum levels of cefazolin in patients being managed with total hip arthroplasty was studied . Eighteen patients, thirteen men and five women, with a mean age of sixty-five years (range, forty to eighty-five years) were enrolled in the study . Fifteen had a primary total hip arthroplasty and three, a revision . Each patient served as his or her own control . Baseline clearance of cefazolin was determined at a minimum of forty-eight hours before the operation . Each patient received one gram of cefazolin intravenously . Serial serum concentrations were determined from specimens drawn at zero, five, ten, twenty, thirty, sixty, 120, 240, and 300 minutes after administration . Fifteen minutes before the skin incision was made, each patient again received one gram of cefazolin intravenously . Serum samples were collected at the same time-intervals, and the serum levels of cefazolin were determined with use of capillary electrophoresis . Data regarding intraoperative blood loss as well as replacement of fluid and blood were recorded . The administration of the antibiotic, retrieval of the serum samples, and estimation of the blood loss were performed by the same person in the same manner for all patients . The preoperative and intraoperative creatinine clearances (mean and standard deviation), estimated with use of the formula of Cockcroft and Gault, were 62.06 +/- 21.28 and 74.02 +/- 24.75 milliliters per minute, respectively . The amount of intraoperative blood loss averaged 1137 +/- 436 milliliters (range, 675 to 2437 milliliters) . The preoperative and intraoperative cefazolin clearances averaged 0.49 +/- 0.21 and 0.52 +/- 0.30 milliliter per minute per kilogram, respectively . During joint replacement, the commonly accepted interval between doses of cefazolin is four hours . In the present study, the serum level of cefazolin at four hours was forty-five micrograms per milliliter . This corresponds to an osseous concentration that well exceeds the minimum inhibitory concentration for Staphylococcus aureus, which is 0.5 microgram per milliliter . This study suggests that, with blood losses of less {corrected} than 2000 milliliters, it is not necessary to administer cefazolin at intraoperative intervals of less than four hours in order to maintain a concentration of antibiotics that is higher than the minimum inhibitory concentration for the most common infecting organisms.

Surgery, 1996 Aug, 120(2), 382 - 7; discussion 388
Hypoxemia/reoxygenation down-regulates interleukin-8-stimulated bactericidal activity of polymorphonuclear neutrophil by differential regulation of CD16 and CD35 mRNA expression; Knowles R et al.; BACKGROUND: The purpose of this study was to determine the effects of hypoxemia/reoxygenation (H/R) on the regulation of interleukin-8 (IL-8)-stimulated human polymorphonuclear neutrophil (PMN) bactericidal activity . METHODS: Venous human whole blood was rendered normoxic (Pvo2 saturation 60% to 80%), hypoxemic (Pvo2 saturation, less than 15%), or H/R (Pvo2 saturation more than 97%) by dialyzing the blood against a gas mixture of N2/H2/CO2 +/- 30% O2 . Two hundred microliter aliquots from each study group were incubated with IL-8 (50 ng/ml) for 45 minutes before fluorescein isothiocyanate-conjugated mouse antihuman CD16 or CD35 antibodies were added . Bactericidal activity was measured with the release of 51Cr from labeled bacteria at 1:1, 5:1, and 10:1 PMN-target ratios . Steady-state mRNA levels for CD16 and CD35 were quantified by Northern blot analyses . RESULTS: H/R reduced PMN bactericidal activity compared with hypoxemic levels for staphylococcus aureus (48 +/- 5.6 versus 27 +/- 3.3) and Escherichia coli (58 +/- 7.1 versus 33 +/- 4.2) . H/R reduced the surface expression of CD16 but not CD35 (mean channel fluorescence CD16, 610 +/- 70 versus 310 +/- 30 for hypoxemia versus H/R; p < 0.01) . After H/R was performed, IL-8 decreased mRNA levels for CD16 but not for CD35 compared with levels seen during hypoxemia + IL-8 . CONCLUSIONS: H/R down-regulates IL-8-stimulated PMN bactericidal activity by decreasing steady-state mRNA levels and surface expression of CD16 . PMN bactericidal capability after H/R + IL-8 is primarily complementary and not Fc gamma receptor dependent.

South Med J, 1996 Aug, 89(8), 818 - 20
Fragmentation hemolysis: an unusual indication for valve replacement in native valve infective endocarditis; Gradon JD et al.; Intravascular mechanical fragmentation of erythrocytes is an uncommon occurrence in native valve infective endocarditis . We report a case of fragmentation hemolysis in a patient with tricuspid valve endocarditis due to Staphylococcus aureus . She received transfusion of multiple units of packed red blood cells and ultimately required surgical removal of the affected valve to control the hemolytic process . We believe this to be only the fifth such reported case and the first in which surgical therapy was necessary to control the hemolytic process.

J Infect Dis, 1996 Aug, 174(2), 417 - 21
Effect of granulocyte colony-stimulating factor on the course of infection with gram-positive bacteria in mice during granulocytopenia induced by sublethal irradiation or cyclophosphamide; Buisman AM et al.; This study assesses the effect of granulocyte colony-stimulating factor (G-CSF) on the outcome of infection with Listeria monocytogenes or Staphylococcus aureus in mice during leukocytopenia induced by sublethal total body irradiation or cyclophosphamide treatment . The role of granulocytes during infection was assessed in the thigh muscle, spleen, and liver . G-CSF treatment in naive mice increased the number of blood granulocytes; upon infection, these numbers increased further, but G-CSF did not affect the outgrowth of bacteria in the tissues . Cyclophosphamide treatment and sublethal irradiation decreased the number of blood granulocytes, which was not affected by G-CSF treatment . However, during infection in cyclophosphamide-treated mice, G-CSF increased the number of granulocytes in the circulation and at the site of infection and decreased the number of bacteria in the tissues . Treatment with G-CSF did not affect the number of granulocytes or the course of infection in irradiated mice.

J Infect Dis, 1996 Aug, 174(2), 414 - 7
A new model of experimental prosthetic joint infection due to methicillin-resistant Staphylococcus aureus: a microbiologic, histopathologic, and magnetic resonance imaging characterization; Belmatoug N et al.; Partial knee arthroplasty was done in rabbits with a silicone-elastomer implant . Immediately after closing the surgical wound, 5 x 10(6) cfu of methicillin-resistant Staphylococcus aureus was injected into the joint . Disease evolution was studied at different stages of infection up to 8 weeks . Prosthetic infection developed in all animals . Gross pathology and histopathologic changes were characteristic of joint and bone infection . Quantitative bacterial counts from infected bone confirmed disease chronicity . The mean number of colony-forming units per gram of bone +/- SD 1 week after infection was 4.84 +/- 0.24 log10 cfu/g and remained stable from week 1 to week 8 . Magnetic resonance imaging showed evidence of prosthetic infection as of week 1, while only mild radiologic changes of bone were seen 2 weeks after infection . This model produces a prosthetic infection that is reproducible and close to that of human prosthetic infection.

Am J Ophthalmol, 1996 Aug, 122(2), 245 - 54
The effect of Staphylococcus aureus phage lysate vaccine on a rabbit model of staphylococcal blepharitis, phlyctenulosis, and catarrhal infiltrates; Giese MJ et al.; PURPOSE: To evaluate the effect of Staphylococcus aureus phage lysate (SPL) vaccination on the development of blepharitis, corneal phlyctenules, and catarrhal infiltrates and on the development of antibodies and the delayed-type hypersensitivity response to S . aureus . METHODS: Eighty rabbits received an intradermal immunization of cell wall-complete Freund's adjuvant followed by a booster immunization . Rabbits were given topical applications of viable S . aureus in both eyes and 40 rabbits received subcutaneous SPL vaccinations . Clinical observations were made weekly . An enzyme-linked immunosorbent assay was used to measure IgG, IgA, and IgM antibody levels to ribitol teichoic acid in sera, corneas, and tears . The delayed-type hypersensitivity response was evaluated by skin testing after subcutaneous injection of staphylococcal antigens . RESULTS: In the SPL-vaccinated group, phlyctenules developed in eight of 40 rabbits while blepharitis developed in 13 of 40 . In the nonvaccinated group, phlyctenules developed in three of 40 rabbits and blepharitis developed in five of 40 . The number of rabbits with blepharitis was significantly higher in the SPL-vaccinated group than in the nonvaccinated group . In general, the antibody response to ribitol teichoic acid was enhanced, while the delayed-type hypersensitivity response to S . aureus was depressed . CONCLUSIONS: Vaccination with SPL was not found to have a beneficial effect on the development of blepharitis, phlyctenules, and catarrhal infiltrates in our rabbit model.

J Pediatr Hematol Oncol, 1996 Aug, 18(3), 323 - 6
Pyomyositis during induction chemotherapy for acute lymphocytic leukemia; Corden TE et al.; PURPOSE: Pyomyositis is a rare disease in temperate climate regions and frequently has a subacute presentation . Because of this, the entity is often misdiagnosed . PATIENTS AND METHODS: Two boys with acute lymphocytic leukemia (ALL) who presented with muscle pain, shortly after receiving induction chemotherapy, were evaluated . RESULTS: Presenting physical examination and laboratory findings were unremarkable except for extremity pain and tenderness . These symptoms were initially attributed to a neurotoxic side effect of vincristine . As the children's symptoms progressed, muscle abscess formation was finally delineated by gallium and computed tomography scans, and the diagnosis of pyomyositis was made . In both cases, the invading organism was Staphylococcus aureus . Both children responded well to incision and drainage of the abscesses and antibiotic therapy . CONCLUSION: Four cases of pyomyositis occurring in ALL patients shortly after induction chemotherapy have now been described . We feel that when children from this population present with muscle pain, pyomyositis should be part of the differential diagnosis . With early medical and surgical intervention, morbidity and mortality can be avoided.

J Biotechnol, 1996 Jul 31, 48(3), 201 - 8
Optimization of the rate of DNA hybridization and rapid detection of methicillin resistant Staphylococcus aureus DNA using fluorescence polarization; Tsuruoka M et al.; The hybridization rate of two complementary single-stranded DNA 24-mers was determined at various NaCl concentrations using a fluorescence polarization method . The rate was taken as the rate constant of the second order reaction, obtained by mathematical fitting of the time course curves of hybridization . The rate increased with the NaCl concentration, plateauing in the concentration range of about 1-2 M . Over the temperature range of 46 degrees C to 56 degrees C, it was found that in 0.8 M NaCl, hybridization was complete in under 10 min and that the difference in the polarization values between specific hybridization and non-specific binding was greater at lower temperatures . Under the optimized conditions of 0.8 M NaCl at 46 degrees C, the time for DNA hybridization to reach 90% completion decreased to less than 5 min . The assay time for one sample was 10 min and the detection limit was of the order of 10(-10) M (40 fmol per assay) . Under the optimized conditions, the DNA of methicillin resistant Staphylococcus aureus (MRSA), which had been multiplied by PCR, could be detected within 10 min.

J Mol Biol, 1996 Jul 26, 260(4), 553 - 69
The refined crystal structure of toxic shock syndrome toxin-1 at 2.07 A resolution; Papageorgiou AC et al.; The pyrogenic toxin toxic shock syndrome toxin-1 from Staphylococcus aureus is a causative agent of the toxic shock syndrome disease . It belongs to a family of proteins known as superantigens that cross-link major histocompatibility class II molecules and T-cell receptors leading to the activation of a substantial number of T cells . The crystal structure of this protein has been refined to 2.07 A with an Rcryst value of 20.4% for 51,240 reflections . The final model contains three molecules in the asymmetric unit with good stereochemistry and a root-mean-square deviation of 0.009 A and 1.63 from ideality for bond lengths and bond angles, respectively . The overall fold is considerably similar to that of other known microbial superantigens (staphylococcal enterotoxins) . However, a detailed structural analysis shows that toxic shock syndrome toxin-1 lacks several structural features that affect its specificity for V beta elements of the T-cell receptor and also its recognition by major histocompatibility class II molecules.

Am J Physiol, 1996 Jul, 271(1 Pt 2), R149 - 56
Microglia digest Staphylococcus aureus into low molecular weight biologically active compounds; Fincher EF 4th et al.; Excess sleep and fever are central nervous system (CNS) facets of the acute phase response; these responses are induced by microbial products, such as muramyl peptides, via their ability to enhance cytokine production . Although peripheral macrophages are known to digest bacteria, thereby releasing muramyl peptides that, in turn, stimulate cytokine production, it was unknown whether CNS phagocytes such as microglia also had this capacity . Primary cultures of microglia were allowed to phagocytize and digest Staphylococcus aureus radiolabeled with a cell wall-specific marker . Radiolabeled low molecular weight substances released into the culture medium were partially purified and tested for the ability to induce excess sleep, fever, and cytokine production . These substances increased non-rapid eye movement sleep, electroencephalographic slow-wave activity, and brain temperature after intracerebroventricular injection into rabbits . They also induced interleukin-1, tumor necrosis factor, and the interleukin-1 receptor antagonist production in human monocytes . Results suggest that microglia perform fundamental macrophage functions and further implicate microglia as resident immunocompetent cells.

J Pept Sci, 1996 Jul-Aug, 2(4), 223 - 32
Hydrophobic effects on antibacterial and channel-forming properties of cecropin A-melittin hybrids; Juvvadi P et al.; The design of cecropin-melittin hybrid analogues is of interest due to the similarities in the structure of the antimicrobial peptides cecropin and melittin but differences in their lytic properties . We suspected that a hydrophobic residue in position 2 of milittin (Ile8 in the hybrid) plays an important role in the activity of the 15-residue hybrid, KWKLFKKIGAVLKVL-NH2, {CA(1-7)M(2-9)NH2} and have now examined its role in the analogue toward five test bacteria . Deletion of Ile8 reduced activity, and it was not restored by lengthening to 15 residues by addition of another threonine at the C-terminus . Replacement of Ile8 by a hydrophobic leucine maintained good activity and Ala8 was equally active for four organisms, although less active against Staphylococcus aureus . Replacement by the hydrophilic Ser8 strongly reduced potency against all five organisms . Deletion of Leu15 decreased activity, but addition of Thr16 maintained good activity . The presence of hydrophobic residues appears to have a significant effect on the process of antibacterial activity . These peptide analogues showed voltage-dependent conductance changes and are capable of forming ion-pores in planar lipid bilayers . The antibacterial action of the peptides is thought to be first an ionic interaction with the anionic phosphate groups of the membrane followed by interaction with the hydrocarbon core of the membrane and subsequent reorientation into amphipathic alpha-helical peptides that form pores (ion-channels), which span the membrane . The analogue also showed an increase in alpha-helicity with an increase in hexafluoro 2-propanol concentration.

Microb Drug Resist, 1996 Summer, 2(2), 277 - 86
A phosphoglucomutase-like gene essential for the optimal expression of methicillin resistance in Staphylococcus aureus: molecular cloning and DNA sequencing; Wu S et al.; We describe here the cloning and sequencing of a new auxiliary gene identified by Tn551 insertional mutagenesis of the highly and homogeneously methicillin-resistant Staphylococcus aureus strain COL . The insertionally inactivated mutant RUSA315 had intact mecA and normal amounts of PBP2A, but drastically reduced antibiotic resistance (drop in methicillin MIC from 1600 to 1.5 micrograms ml-1), a unique heterogeneous phenotype, and a compositional change in the cell wall characterized by the complete disappearance of the unsubstituted disaccharide pentapeptide from the peptidoglycan . Cloning in E . coli followed by sequencing located the Tn551 insert omega 720 in an open reading frame of 451 codons, provisionally called femR315, defining a polypeptide with a deduced amino acid sequence that showed over 26% sequence identity and 57% overall sequence similarity with the phosphoglucomutase (PGM) gene of E . coli . The Tn551 insertion site of a previously described mutant 12F (femD) also lies in the same gene as femR315 . The wild-type form of femR315 subcloned in a shuttle vector fully restored expression of high level (parental) methicillin resistance in mutant RUSA315 . The exact biochemical function of femR315 is not known . However, enzymes similar to PGM catalyze the isomerization of hexose and hexosamine phosphates leading to the formation of glucosamine-1-P, which is an obligate precursor in the biosynthesis of UDP-N-acetylglucosamine (UDP-NAGA) . We propose that the suppression of methicillin resistance in RUSA315 is related to some functional or quantitative abnormality of UDP-NAGA metabolism.

Microb Drug Resist, 1996 Summer, 2(2), 261 - 8
The role of the nonconserved residues at position 167 of class A beta-lactamases in susceptibility to mechanism-based inhibitors; Guo F et al.; Differences in specificities between the class A beta-lactamases for both substrate and inhibitors are known . The role of the nonconserved amino acid residue at position 167 of the class A enzyme, which forms a cis bond with the catalytically essential Glu-166 residue, 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 thr-167 with the corresponding Staphylococcus aureus PC1 residue Ile . Kinetic data obtained from the purified Thr-167-Ile B . cereus 569/H beta-lactamase was compared to that obtained from the wild-type B . cereus and S . aureus enzymes and indicated that the replacement had little effect on the Michaelis parameters for the hydrolysis of S- and A-type penicillins . However, the Thr-167-Ile enzymes became more S . aureus PC1-like in its response to the mechanism-based inhibitors clavulanic acid and 6-beta-(trifluoromethane sulfonyl)amidopenicillanic acid sulfone . A model for the role of this nonconserved residue at position 167 in the mechanism of inactivation by mechanism-based inhibitors is proposed.

Microb Drug Resist, 1996 Summer, 2(2), 257 - 60
Borderline susceptibility to methicillin in Staphylococcus aureus: a new mechanism of resistance?
Montanari MP, Massidda O, Mingoia M, Varaldo PE.
Staphylococcus aureus strains with borderline levels of susceptibility or resistance to antistaphylococcal penicillinase-resistant penicillins (PRPs) were initially reported as neither heteroresistant nor multiply resistant organisms, producing large amounts of beta-lactamase, and becoming fully susceptible to PRPs in the presence of beta-lactamase inhibitors . This borderline susceptibility or low-level resistance was suggested to be due to beta-lactamase hyperproduction: according to this hypothesis, the staphylococcal beta-lactamase, when hyperproduced, would succeed in partially hydrolyzing methicillin and related PRPs . However, later studies demonstrated that borderline PRP susceptibility cannot be explained soley on this basis, beta-lactamase hyperproduction being neither sufficient nor necessary to determine the borderline phenotype . Intrinsic mechanisms have also been reported to be associated with some borderline PRP susceptible S . aureus strains . The more recent discovery of a PRP-hydrolyzing beta-lactamase (methicillinase) produced, in addition to the conventional penicillinase, by borderline S . aureus strains suggests that this second, more specific beta-lactamase is more likely to be responsible for the borderline phenotype than an increased amount of the penicillinase . The slow kinetics of PRP hydrolysis by methicillinase is consistent with its association with reduced susceptibility rather than true resistance to PRPs . The combined effect of methicillinase plus penicillinase on some common substrates might explain the increased beta-lactamase activity often observed in borderline S . aureus strains.

Microb Drug Resist, 1996 Summer, 2(2), 193 - 9
Effects of penicillin-binding protein 4 overproduction in Staphylococcus aureus; Henze UU et al.; The pbp4 gene of a Staphylococcus aureus strain selected stepwise in vitro for growth on increasing concentrations of penicillin and of its susceptible parent strain showed overall identity except in the promoter region . In the mutant a deletion upstream of the pbp4 structural gene removed 90 nucleotides (nt) that were framed by a 12 nt inverted repeat . This deletion occurred in step 4 of the in vitro selection procedure and was paralleled by a significant increase in the penicillin-binding protein 4 (PBP4) production . The in vitro step selected mutant showed a remarkable increase in the cross-linking of the peptidoglycan compared to its parent . This was linked to morphological changes in the appearance of the cells, which were surrounded by a very thick and fuzzy cell wall.

Rev Assoc Med Bras, 1996 Jul-Sep, 42(3), 147 - 50
{Study of the susceptibility of Staphylococcus sp . and Enterococcus sp . to teicoplanin and vancomycin}; Mimica I et al.; PURPOSE: The study was performed in order to evaluate the susceptibility of Enterococcus and Staphylococcus to teicoplanin and vancomycin . METHODS: 150 Enterococcus strains and 450 Staphylococcus strains (298 Staphylococcus aureus and 152 negative coagulase strains) isolated in three Brazilian hospitals were studied . The MICs were determined using teicoplanin and vancomycin E Test strips . The range of the antimicrobial concentration in each strip went from 256 mcg/mL to 0.016 mcg/mL . Diffusion tests using disks impregnated with 10 mcg of teicoplanin and 30 mcg of vancomycin were also performed . RESULTS: All the 298 Staphylococcus aureus strains were susceptible to the two antimicrobials . Three of the 152 negative coagulase strains presented intermediate susceptibility to teicoplanin (MICs between 8 and 16 mcg/mL) . Four of the 150 Enterococcus strains presented intermediate susceptibility to vancomycin but were totally susceptible to teicoplanin . CONCLUSION: According to these results teicoplanin and vancomycin are good therapeutical options in the treatment of staphylococcal and enterococcal infections.

Klin Monatsbl Augenheilkd, 1996 Jul, 209(1), 13 - 20
{Perioperative conjunctival flora}; Herde J et al.; BACKGROUND: The conjunctival flora is of great interest for each case of intraocular operation preventing postoperative infections . Despite of negative cultures before the operation we investigated in a prospective randomized study perioperatively the bacterial situation of the conjunctiva in 105 patients . MATERIAL AND METHODS: We took conjunctival swabs for microbiological examination from patient's eye operated on cataract or glaucoma, on the day of admission to the eye clinic and in the morning of the operating day . In addition, specimens were taken by nurses with Transwab MW-172 P before the local anaesthesia, disinfection of the conjunctiva and lids and application of eye drops, after these procedures by a research worker, at the end of the operation by the surgeon and two to three days after the operation by nurses with Transwab MW-172 P again . In 53 patients we collected lacrimal fluid to measure the lysozyme concentration . RESULTS: Out of 686 conjunctival swabs we have found 126 (18.4%) positive cultures . Staphylococcus epidermidis had the highest incidence (109 = 86.5%) followed by Staphylococcus aureus (7 = 5.5%) . Only in 28 eyes all conjunctival swabs, taken at different times, were negative . There was an increase of positive cultures from routine swabs on the day of admission from 13 (12.4%), to 33 (31.7%) in the swabs taken on the day of the operation in the morning . On the other side the positive cultures decreased then continuously before and after the preparation of the operation, at the end of the operation and during two to three days postoperatively . There was'nt any statistical correlation between the concentration of the lacrimal lysozyme and the rate of positive cultures . CONCLUSION: The preoperative bacteriological diagnostic of the conjunctiva is important mainly for the prevention of postoperative endophthalmitis despite the transience and fluctuation of the conjunctival flora but also in case of endophthalmitis for rapid specific antibiotical therapy.

Plasmid, 1996 Jul, 36(1), 1 - 8
Nucleic acid sequence and affiliation of pLUG10, a novel cadmium resistance plasmid from Staphylococcus lugdunensis; Chaouni LB et al.; Tolerance of Staphylococcus lugdunensis to relatively high levels of cadmium is mediated by a 3117-bp plasmid, pLUG10 . Sequencing reveals three major open reading frames (ORFs) in a single orientation . One ORF encompasses the origin of replication and its predicted product (RepL: 350 amino acids (aa)) shows 70% homology in its deduced aa sequence with Rep proteins of the pT181 family . A lagging strand conversion signal (palA) very similar to that of class 1 plasmids is present outside the rep-ori locus . The other two ORFs of 209 and 116 aa show 92.5% homology between their deduced aa sequences and the CadB and CadX peptides from the pOX6 plasmid of Staphylococcus aureus . The CadX-like peptide is 40% homologous to the S . aureus CadC product . Deletion of the C-terminal cadX gene by restriction enzyme digestion or frame-shift inactivation of the cadB gene reduced, but did not completely abolish, cadmium resistance . The two gene products may act cooperatively to confer cadmium resistance in S . lugdunensis.

Ann Acad Med Singapore, 1996 Jul, 25(4), 609 - 11
Pyomyositis revisited; Kong NC et al.; Pyomyositis, purportedly a common tropical infection affecting mainly healthy adults and children, appears to be most uncommon in this region . We report a case of pyomyositis caused by a Methicillin-resistant Staphylococcus aureus (MRSA) in a previously healthy army officer . This case serves to illustrate the difficulty in recognising this disease entity, which is why many cases may have been missed . With the increasing incidence of MRSA nosocomial infections, the emergence of MRSA in a hitherto community-acquired infection poses a major concern especially since intravenous drug abuse and acquired immune deficiency syndrome (AIDS) are on the rise in our country . We hope to inculcate greater awareness of this infection.

Ann Acad Med Singapore, 1996 Jul, 25(4), 492 - 5
Validity of Bayesian forecasting programme in therapeutic drug monitoring of vancomycin in a surgical intensive care unit: a prospective evaluation; Balram C et al.; The objectives of this study were: (a) to assess the predictive performance of a 2-compartment Bayesian vancomycin forecasting programme in critically ill patients in the surgical intensive care unit, and (b) to show the applicability of the programme, which is based on parameters derived from Western population, in our local Asian population . Twenty critically ill patients were enrolled into the study programme . All patients received multiple-dose vancomycin for infections due to methicillin-resistant staphylococcus aureus (MRSA) . The patients dosage regimen were optimised by entering a set of peak and trough vancomycin serum levels into a clinical computer program (MB; USC*PACK PC collection; University of Southern California, USA) by utilising a 2-compartment Bayesian population model . The correlation between observed and predicted serum peak and trough concentrations were evaluated for both the non-fitted and fitted models by linear regression analysis . There was a significant correlation between observed and predicted concentrations using the fitted model (r = 0.97, P < 0.05) . There was no significant correlation of these concentrations in the non-fitted model (r = 0.8) . This study shows that the Bayesian programme is able to accurately predict future vancomycin concentrations in our local Asian population . It is possible to optimise patients dosage regimens with the knowledge of two concentrations of vancomycin in order to achieve targeted therapeutic goals.

Blood Coagul Fibrinolysis, 1996 Jul, 7(5), 522 - 9
Effects of endothelial cells on activity of staphylokinase; Ueshima S et al.; Staphylokinase (SAK), produced by Staphylococcus aureus, induces fibrinolytic activity in circulation without systemic fibrinolytic activation . Since the effect of blood vessels on the activity of SAK has not yet been clarified, plasminogen activator (PA) activity of SAK in the presence or absence of endothelial cells was analyzed . The endothelial cells used in this experiment were of a cloned established cell line (TKM-33) . In the expression of PA activity by SAK or streptokinase (SK), the kinetic constants revealed as Vmax/km were increased about 1.5-fold in the presence of endothelial cells . Furthermore, an initial lag phase which was observed during the plasminogen activation by SAK was markedly shortened in the presence of endothelial cells . In the case of SK, an initial lag phase was not observed in the absence or presence of endothelial cells . Although PA activity of SAK was inhibited by alpha 2-antiplasmin (alpha 2-AP), the inhibitory effect of alpha 2-AP in the presence of endothelial cells was weaker than in the absence of endothelial cells . The cyanogen bromide digested fibrinogen fragment-2 (FCB-2) distinctly enhanced the PA activity of SAK in the absence and the presence of endothelial cells . However, alpha 2-AP and FCB-2 did not cause a significant alteration of PA activity of SK even in the absence or presence of endothelial cells . These findings suggest that PA activity of SAK is enhanced by endothelial cells, but inhibited by alpha 2-AP . Moreover, PA activity of SAK is further enhanced by fibrin clot in the presence of endothelial cells.

Perit Dial Int, 1996 Jul-Aug, 16(4), 352 - 6
Nasal carriage and peritonitis by Staphylococcus aureus in patients on continuous ambulatory peritoneal dialysis: a prospective study; Wanten GJ et al.; OBJECTIVE: To establish whether or not patients on continuous ambulatory peritoneal dialysis (CAPD) using current infection control measures who are nasal carriers of Staphylococcus aureus are at risk for the development of S . aureus peritonitis . DESIGN: A prospective 22-month study analyzing nasal and skin/nasal (i.e., nasal and/or exit-site) carrier status for S . aureus and peritonitis episodes . Nasal swab cultures for S . aureus were taken with 1- to 3-month intervals; swab cultures from the catheter exit site were taken only when infection was suspected . SETTING: Renal unit, tertiary-care center . PATIENTS: All patients on CAPD at our center that could be observed during at least 2 months . INTERVENTIONS: None . MAIN OUTCOME MEASURES: Nasal and skin/nasal carrier status, occurrence of peritonitis . RESULTS: Of 54 enrolled patients, 31 (57%) were nasal carriers for S . aureus: 6 of these 31 developed S . aureus peritonitis as opposed to none of 23 non-carriers (p = 0.03) . The S . aureus peritonitis rate in 28 skin/nasal carriers was increased when compared to non-carriers (p = 0.02), but there was no difference between chronic and intermittent skin/nasal carriers (p = 0.63) . CONCLUSIONS: In our population, nasal carriers are at increased risk for the development of S . aureusperitonitis . Further studies should evaluate the effect of eradication of nasal carriage of S . aureus and the effect of additional preventive hygienic measures on the occurrence of peritonitis by S . aureus.

J Antimicrob Chemother, 1996 Jul, 38 Suppl A, 97 - 106
Susceptibility of respiratory strains of Staphylococcus aureus to fifteen antibiotics: results of a collaborative surveillance study (1992-1993) . The Alexander Project Collaborative Group; Schito GC et al.; As part of the Alexander Project during 1992 and 1993, 690 Staphylococcus aureus strains isolated from community-acquired lower respiratory tract infections by clinical microbiology centres located in Europe and the USA were analysed by a co-ordinating laboratory that determined minimal inhibitory concentrations of 15 antimicrobial agents using a standardised microdilution technique . The prevalence of penicillin-susceptible microorganisms in this collection of pathogens was significantly higher in Europe (21.2%) than it was in the USA (12.1%) . Most isolates (72.5%), however, were strains that had acquired the ability to synthesise a beta-lactamase but which were sensitive to methicillin . The incidence of methicillin-resistance (9.1% overall) was highly variable depending on geographic location and year of isolation . Analysis of MIC50, MIC90, MIC range and modal MIC of the 15 antibiotics assayed disclosed no major differences between the data sets obtained during the 2-year survey . Except for methicillin-resistant S . aureus, the activity of all the beta-lactams tested, with the exclusion of penicillin, amoxycillin and cefixime (that were completely inactive), was satisfactory . The effect of beta-lactamase synthesis was inhibited by the combination of amoxycillin with clavulanate, and by cefuroxime and ceftriaxone . Cefaclor was slightly less effective . Erythromycin, clarithromycin and azithromycin showed identical cross-resistance rates (around 10%) . Resistance to the macrolides was more frequent in the USA than in Europe and was the sole trait found to increase during the survey . Doxycycline, chloramphenicol, co-trimoxazole and the two fluoroquinolones tested (ofloxacin and ciprofloxacin) were remarkably effective (resistance lower than 1%) . Only doxycycline and, to a lesser extent, co-trimoxazole were partially active against methicillin-resistant strains.

Mol Immunol, 1996 Jul, 33(10), 891 - 900
Bacterial superantigens induce V beta-specific T cell receptor internalization; Makida R et al.; Staphylococcal enterotoxins can cause toxic shock syndrome and autoimmune diseases . Circulating T cells from these diseases have a very wide range of expression in particular T cell receptor (TCR) beta chain variable regions (V beta) . One possibility for this wide range of TCR V beta expression is that during acute infection with organisms secreting superantigens (SAg) these potent molecules might modulate TCR expression . To test this hypothesis, we investigated the potential effects of SAg on TCR V beta cell surface expression . Peripheral blood mononuclear cells (PBMC) from healthy donors were incubated with staphylococcal SAg . Toxic shock syndrome toxin-1 (TSST-1) induced downregulation of V beta 2 expression, whereas staphylococcal enterotoxin (SE) B induced V beta 3-and V beta 12-specific downregulation . TSST-1 did not interfere with anti-V beta 2 mAb binding . Therefore, this downregulation was not due to steric hindrance of Ab binding by TSST-1 . TSST-1 induced V beta 2 downregulation was time-, dose- and temperature-dependent . CD3 expression decreased in parallel with reduction of V beta expression . CD4 and CD8 expression were only slightly decreased . CD2, CD25 and HLA-DR expression were upregulated following TSST-1 stimulation of T cell lines . To investigate the fate of TCR after toxin stimulation, V beta 8+ Jurkat T cells were incubated with SEE which is known to stimulate V beta 8+ T cells, and analysed with fluoresence microscopy, and immunoprecipitation and Western blotting . After SEE stimulation, there was an increase in V beta 8 molecules found in the cytoplasm which correlated with loss of cell surface V beta 8 molecules, suggesting internalization of cell surface V beta 8 molecules was induced by SEE stimulation . Shedding of V beta 8 molecules into the culture supernatant was not detected . These data demonstrate that SAg mediated downregulation of TCR expression occurs primarily as the result of TCR internalization . This downregulation phenomenon may have physiological and pathological consequences in patients infected with Staphylococcus aureus.

Proteins, 1996 Jul, 25(3), 286 - 99
Folding simulations and computer redesign of protein A three-helix bundle motifs; Olszewski KA et al.; In solution, the B domain of protein A from Staphylococcus aureus (B domain) possesses a three-helix bundle structure . This simple motif has been previously reproduced by Kolinski and Skolnick (Proteins 18: 353-366, 1994) using a reduced representation lattice model of proteins with a statistical interaction scheme . In this paper, an improved version of the potential has been used, and the robustness of this result has been tested by folding from the random state a set of three-helix bundle proteins that are highly homologous to the B domain of protein A . Furthermore, an attempt to redesign the B domain native structure to its topological mirror image fold has been made by multiple mutations of the hydrophobic core and the turn region between helices I and II . A sieve method for scanning a large set of mutations to search for this desired property has been proposed . It has been shown that mutations of native B domain hydrophobic core do not introduce significant changes in the protein motif . Mutations in the turn region were also very conservative; nevertheless, a few mutants acquired the desired topological mirror image motif . A set of all atom models of the most probable mutant was reconstructed from the reduced models and refined using a molecular dynamics algorithm in the presence of water . The packing of all atom structures obtained corroborates the lattice model results . We conclude that the change in the handedness of the turn induced by the mutations, augmented by the repacking of hydrophobic core and the additional burial of the second helix N-cap side chain, are responsible for the predicted preferential adoption of the mirror image structure.

Pediatr Dermatol, 1996 Jul-Aug, 13(4), 278 - 80
Periauricular eczematization in childhood atopic dermatitis; Kim KH et al.; We investigated the prevalence of periauricular eczematization (PAE) in children with atopic dermatitis (AD) in Korea, and evaluated the clinical significance of the lesion in terms of its treatment in relation to a possible pathogenetic role for Staphylococcus aureus . Tentatively, PAE was classified as infraauricular and postauricular fissuring, which were observed in 62 (57.9%) and 37 (34.6%) of 107 patients, respectively . Sixty eight patients (64.5%) had infraauricular or postauricular fissures, or both, and this prevalence was significantly (p < 0.01) higher than that in controls (1.3%) . Staphylococcus aureus was cultured from oozing material from infraauricular fissures in 12 of 14 patients, and topical application of erythromycin cream to the ear lesions led to faster and more definite improvement . Our study shows that PAE is a characteristic clinical manifestation of AD, probably induced by S . aureus . Topical antibiotics are worth trying for effective management of this disorder.

J Burn Care Rehabil, 1996 Jul-Aug, 17(4), 346 - 50
Cellulitis associated with burn scars: a retrospective review; Mukhdomi GJ et al.; This retrospective study evaluated 55 patients with burn scar cellulitis who required hospital readmission from January 1977 to July 1994 . The overall incidence of burn scar cellulitis was 1.6%, and it was highest among patients who had undergone fascial excision (17.1%) as compared to those who had undergone tangential excisions (1.5%), or those who received nonoperative therapies (0.7%) . Also, the use of meshed graft 4:1 for wound coverage exhibited a higher incidence of scar cellulitis (17.1%) as compared to the use of 2:1 meshed graft (1.1%) . Methicillin-sensitive Staphylococcus aureus was the most common offending organism (69%), so it was concluded that all patients should be treated initially with antibiotics having methicillin-sensitive staphylococcal coverage . The lower extremity was involved 80% of the time, and the most commonly affected age group was 11 to 15 years . All patients were healthy and displayed no vascular, immunologic, or neurologic compromise at the time of readmission.

Intensive Care Med, 1996 Jul, 22(7), 683 - 7
Rapid identification of Staphylococcus aureus in bronchoalveolar lavage fluid using a DNA probe (Accuprobe); Allaouchiche B et al.; OBJECTIVE: Staphylococcus aureus is one of the prominent causative agents of ventilator-associated pneumonia (VAP) . Gram staining of bronchoalveolar lavage (BAL) fluid is not always reliable . A nonisotopid probe (Accuprobe) has been developed by Gen-Probe for the specific identification of S . aureus isolated from cultures . This study was undertaken to assess the reliability of this probe for the early diagnosis of S . aureus VAP . DESIGN: A prospective study in 120 consecutive patients . SETTING: Department of intensive care medicine at a university hospital . PATIENTS: 120 ventilated patients (70 males and 50 females; mean age 52 +/- 12 years; mean simplified acute physiologic score = 13 +/- 4) were studied . INTERVENTIONS: 164 bronchoalveolar lavages were performed (none of the patients received prior antibiotic therapy) . MEASUREMENTS AND RESULTS: S . aureus was identified 29 times at significant concentrations (> or = 10(4) cfu/ml) and 7 times at < 10(4) cfu/ml . The sensitivity and specificity of the Accuprobe system were 100 and 96%, respectively . We found agreement between quantitative cultures and probes in 96.3% of cases . CONCLUSIONS: We conclude that this probe provides a rapid (< or = 7 h) and accurate diagnosis of S . aureus pulmonary infection.

Toxicon, 1996 Jul, 34(7), 763 - 9
Amino acid sequence of a lectin-like protein from Lachesis muta stenophyrs venom; Aragon-Ortiz F et al.; The primary structure of the lectin-like protein from Lachesis muta stenophyrs venom was deduced from analysis of the N-terminus and the sequence of peptides obtained after digestion with trypsin, Arg-C enzyme, Staphylococcus aureus V8 protease and endoproteinase Asp-N . Peptides generated by cleavage of the lectin with cyanogen bromide and o-iodosobenzoic acid were also sequenced . Comparison of the complete 135 amino acid residues sequence with those of the lectin from the venom of Crotalus atrox, with platelet coagglutinin from Bothrops jararaca beta-fragment and with the anticoagulant B protein chain from Trimeresurus flavoviridis venom, revealed 92, 46 and 29% identity, respectively . Significant homology was also found with C-type carbohydrate-recognition domain-like structures from invertebrate and vertebrate lectins . To our knowledge, this is the second known primary structure of a lectin-like protein from snake venom.

Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 1996 Jul, 82(1), 34 - 7
Management of contaminated bone grafts: an experimental in vitro study; Hooe W et al.; OBJECTIVES: This study tested various protocols for bone decontamination after bacterial contact to determine if these treatments altered bone structure . STUDY DESIGN: Femurs from five Sprague-Dawley rats were sectioned and separated into eight groups . These were contaminated in a broth containing Pseudomonas aeroginosa and Staphylococcus aureus . Subsequently, the groups were treated with eight different decontamination regimens . A Scheffe's Grouping test was used to statistically compare the bacterial counts after each treatment protocol . RESULTS: Treatment with 4% chlorhexidine gluconate and 4% alcohol, Neosporin, cefazolin, and saline solution had little effect on bacterial growth . However, povidone-iodine, autoclaving, and ethyl alcohol with ethanol did significantly decrease the bacterial colony counts from the bone specimens . The autoclave and ethyl alcohol/ethanol induced changes in bony histologic examination . CONCLUSIONS: Results suggested that povidone-iodine decontaminates bone specimens without altering histologic conditions . Determination of successful grafting of bone treated with this protocol is required before its recommendation for clinical use.

Mol Microbiol, 1996 Jul, 21(1), 181 - 95
The 19-residue pro-peptide of staphylococcal nuclease has a profound secretion-enhancing ability in Escherichia coli; Suciu D et al.; Staphylococcus aureus secretes two forms of extracellular nuclease, nuclease A and nuclease B . Nuclease A, consisting of 149 residues, is a proteolytic product of nuclease B, which is a processing intermediate that has a 19-residue N-terminal pro-peptide between the signal peptide and nuclease A . It has been shown that nuclease A can be secreted by Escherichia coli by fusing it to the OmpA signal peptide . We now demonstrate that the addition of the pro-peptide between the OmpA signal peptide and nuclease A leads to a significantly enhanced secretion rate in E . coli . The processing and secretion rates of nuclease B at 37 degrees C were at least 10 times faster than those of nuclease A . Nuclease B was also secreted efficiently under conditions which blocked the secretion of nuclease A, such as secA mutations and the addition of phenethyl alcohol or sodium azide . This enhancing effect of the pro-peptide was not as striking when it was attached to beta-lactamase, indicating that the pro-peptide acts as a specific secretion enhancer for nuclease A . Equilibrium circular dichroism on purified nuclease A and nuclease B indicated that the pro-peptide itself had no significant destabilizing effect on the mature protein . The existence of similar pro-peptides in Gram-positive bacterial secretory proteins indicates that they may also serve as secretion enhancers for individual proteins.

Nucl Med Commun, 1996 Jul, 17(7), 616 - 20
Biodistribution of 111In-labelled IgG and IgM in experimental infection; Oyen WJ et al.; Both the protein used and the conjugation method are factors which may be relevant for targeting infection with 111In-labelled proteins . In this study, human immunoglobulin G (IgG), conjugated to either DTPA or LiLo, and LiLo conjugated human immunoglobulin M (IgM) were evaluated . In rats with Staphylococcus aureus calf muscle infection, biodistribution was determined 6, 24 and 48 h after the injection of 111In-DTPA-IgG, 111InLiLo-IgG or 111In-LiLo-IgM . Absolute abscess uptake of 111In-LiLo-IgG was significantly higher than that of 111In-DTPA-IgG (P < 0.05) . Since blood clearance of 111In-LiLo-IgG was initially significantly slower (P < 0.01), the higher abscess uptake did not result in higher abscess-to-background ratios . 111In-LiLo-IgG accumulated to a greater extent in the liver (P < 0.001) . 111In-DTPA-IgG showed higher uptake in the kidneys and bone marrow (P < 0.001 and P < 0.01, respectively) . Although decreasing over time, 111In-LiLo-IgM showed reasonable abscess uptake and rapid blood clearance, resulting in higher abscess-to-background ratios compared with 111In-LiLo-IgG (P < 0.01) . However, liver and spleen uptake were three- to four-fold higher than that of 111In-LiLo-IgG (P < 0.001) . Compared with DTPA-conjugation, chelation with LiLo has a minor influence on abscess targeting of 111In-labelled IgG . However, differences in blood clearance and organ uptake do occur . 111In-LiLo-IgM shows high relative accumulation in abscesses as well as high liver and spleen uptake . 111In-LiLo-IgM appears promising for imaging infection outside the trunk region.

J Infect, 1996 Jul, 33(1), 11 - 3
Community and hospital acquired Staphylococcus aureus septicaemia: 115 cases from a Dublin teaching hospital; Cunney RJ et al.; Despite advances in diagnostic techniques and antimicrobials, septicaemia due to Staphylococcus aureus remains a common clinical problem with a significant mortality . We retrospectively compared community and hospital acquired cases of S . aureus septicaemia occurring in our 600 bed teaching hospital over a 30 month period . Of 110 episodes 32 (29%) were community acquired and 78 (71%) hospital acquired . A likely primary source was identified in 14 (44%) of community acquired cases and in 73 (94%) of hospital acquired cases . A secondary focus of infection was more common in community acquired cases (17, 53%) than hospital acquired cases (5, 6%) . Mortality was significantly higher in community acquired cases (22% vs . 6%) . An association was also found between the presence of endocarditis and increased mortality, although this did not reach significance . We also compared hospital acquired septicaemia due to methicillin sensitive and methicillin resistant S . aureus found a significantly higher mortality in the methicillin resistant group (22% vs . 3%, P < 0.05) . S . aureus septicaemia remains an important cause of morbidity and mortality, particularly when associated with secondary foci of infection . This study also emphasises the importance of control of methicillin resistant strains in hospital.

Zentralbl Bakteriol, 1996 Jul, 284(2-3), 164 - 9
T-cell activation and proliferation in a case of recurrent menstrual toxic shock syndrome; Arvand M et al.; A case of menses-related toxic shock syndrome with a relapse within 9 days is presented . Cervical smear of the patient yielded growth of a Staphylococcus aureus strain which produced toxic shock syndrome toxin-1 (TSST-1) . Serum antibody against TSST-1 were absent in the first sample which was obtained in the acute phase and did not increase significantly within 5 weeks . We studied the proliferative response of the patient's T cells during and after the acute phase of disease to evaluate whether they have been rendered unresponsive to TSST-1 . We could not detect any reduction in the T cell proliferation at any time . Peripheral T cells of the patient were analysed flow-cytometrically at two different times to determine the expression of the T cell activity markers CD25 and HLA-DR . The expression of HLA-DR was increased during the acute phase and had declined significantly at the time of the second analysis; the CD25 expression remained constant.

J Hosp Infect, 1996 Jul, 33(3), 201 - 6
Carriage of Staphylococcus aureus in the elderly; Parnaby RM et al.; The point prevalence and incidence of Staphylococcus aureus (methicillin-sensitive and -resistant) carriage by inpatients on acute elderly care wards was estimated . The relationship to body site and to previous admissions to hospital or other institutions was determined . Fifty-five patients were included in the point prevalence study and 136 in the incidence study, which was performed over a two-month period . One in three patients carried S . aureus and 1 in 20 was infected . The incidence rate for MRSA was 2.9% . No endemic strain was found . Nostrils were significantly associated with carriage, and skin break isolates were significant in the point prevalence survey . Screening these sites alone would be most cost effective.

Adv Ren Replace Ther, 1996 Jul, 3(3), 222 - 7
Peritoneal catheter exit-site and tunnel infections; Piraino B; Peritoneal catheter exit-site and tunnel infections may lead to peritonitis and catheter loss . Exit-site infections are diagnosed when there is pericatheter erythema and/or purulent drainage . Staphylococcus aureus is the most common cause of both exit-site and tunnel infections . S . aureus nasal carriage is an important risk factor for S . aureus catheter infections . Few other risk factors for catheter infections have been identified . Treatment of catheter infections consists of antibiotic therapy, often prolonged, as well as intensification of exit-site care . Refractory cases may resolve with revision of the tunnel and exit-site with removal of the superficial cuff, but some patients undergoing this procedure will develop peritonitis . Once peritonitis develops from a tunnel infection, the catheter should be replaced . Research on prevention of catheter infections has focused on three areas: antibiotic prophylaxis, exit-site care, and new catheter designs . Several antibiotic protocols, including intranasal mupirocin, cyclical oral rifampin, and exit-site mupirocin, are effective in decreasing S . aureus catheter infections and should be used more widely . New catheter designs may, in the future, prove to further diminish catheter infection and loss, but there are insufficient data at this time to show superiority of one catheter over another.

Adv Ren Replace Ther, 1996 Jul, 3(3), 208 - 17
Clinical considerations in hemodialysis access infection; Albers FJ; Hemoaccess infections remain a substantial cause of morbidity in patients on hemodialysis, especially with the increasing reliance on prosthetic devices as the average age of the hemodialysis population increases . Access manipulation, either through needle puncture or secondary surgical procedures, is the primary etiology of infection . Other conditions such as access location, patient hygiene, and intravenous drug use can cause contamination . Local evidence of inflammation or infection, especially pain and purulence, are the most reliable signs of infection; however, the access can be infected and there may be minimal systemic symptoms . Medical therapy must be directed primarily against Staphylococcus aureus, with vancomycin being used most frequently . There are distinct conditions in which infection with gram-negative bacilli is also common . A coordinated effort between medical management and surgical intervention is essential to optimize therapy . Several situations, such as loss of vascular integrity or infection at anastomosis sites, mandate full excision of the graft . However, the access or at least the access site, can be preserved through creative surgical intervention along with aggressive medical treatment . Approaches to the diagnosis and treatment of infection in autologous arteriovenous fistulae, polytetrafluoroethylene arteriovenous conduits, and cuffed dual-lumen venous hemodialysis catheters are discussed.

Pacing Clin Electrophysiol, 1996 Jul, 19(7), 1105 - 11
The treatment of septicemia in pacemaker patients; Bohm A et al.; The authors analyzed the data of seven patients who had undergone open heart surgery because of pacemaker endocarditis in the past 4 years . Repeated surgical interventions on the pacemaker system were found to be the most common predisposing factors . Staphylococcus aureus and Staphylococcus epidermidis were the most common causative organisms . Two-dimensional echocardiography was important in the diagnosis of cases with atypical clinical picture and negative blood cultures . We concluded that: (1) any pacemaker patient with fever should be considered to have a pacemaker endocarditis; (2) all of these patients should be examined by two-dimensional echocardiography; and (3) the total removal of the infected hardware seems to be the only way to achieve complete recovery.

Med Hypotheses, 1996 Jul, 47(1), 35 - 8
Cancer is a hybrid produced by a relationship between a plant bacterium and a mammalian cell: an original concept; White MW; Facts presented in previously published articles (1-7) support the conclusion that the malignant cell, although of animal origin, metabolizes and respires anaerobically . Facts also support the conclusion that plant bacterial conidia (spores) derived, under duress, from one of the several groups belonging to the Ascomycete family or from the Staphylococcus aureus coagulase positive micro-organism are present intracellularly . It is this group of conidia, when formed, that survives as a primitive oval, spheroidal type of a unicell . They are identical in all respects to the various carbohydrate, protein, and fat molecules . Although these conidia have lost their original outside cell wall and all their enzymes and metabolites, they survive none the less as bacteria by retaining within their cytoplasm a genetically viable anion acceptor complex (oxidant), and their asexual procreative unit . It is this oxidant factor that survives within a sac or cell, as long as it is free of the atmospheric environment . Ultimately, with an ensuing circulating but compatible flow of blood by the host, there develops an annealing process whereby the genes of each species unite to form a plant animal intracellular hybridization . This somatic association accounts for the origin of the metabolic and respiratory anaerobiosis and also for the subsequent growth and pathophysiology that occurs in those living human beings suffering from the various malignant diseases.

Can J Vet Res, 1996 Jul, 60(3), 237 - 40
In vivo expression of exoprotein synthesis with a Sae mutant of Staphylococcus aureus; Rampone H et al.; The expression of exoprotein synthesis of Staphylococcus aureus Sae mutant RC121 and its parental strain was studied under in vivo growth conditions . Cultures of both strains were inoculated into dialysis sacs implanted in sheep peritoneum . Results indicated that similar to in vitro grown mutant cells, Sae mutant RC121 shows diminished synthesis of alpha- and beta-hemolysin, coagulase, DNase and protein A . However, in vitro and in vivo grown mutant cultures showed different exoprotein profiles in SDS-PAGE; some bands from in vivo mutant cultures were diminished or missing and others appeared as more concentrated, when compared with the pattern of the in vivo grown parental strain, while all the exoprotein bands from the in vitro cultures of the mutant were diminished or missing as compared to the in vitro grown parental strain . The virulence of the Sae mutant, assayed by intraperitoneal injection in mice, was lower than that of the parental strain after both in vivo and in vitro growth conditions.

Antimicrob Agents Chemother, 1996 Jul, 40(7), 1665 - 9
NorA plasmid resistance to fluoroquinolones: role of copy number and norA frameshift mutations; Sun L et al.; Staphylococcus aureus NorA protein is a transmembrane multidrug efflux pump that confers low-level resistance to hydrophilic fluoroquinolones . The norA gene promoter is active in Escherichia coli HB101 . We have examined the genetic basis of norA-mediated resistance in E . coli by introducing a wild-type norA gene into HB101 in plasmid pCL1921, pBR322, or pUC18 exhibiting copy numbers that spanned a 22-fold range . Increased ciprofloxacin resistance correlated with norA transcript levels seen by Northern (RNA) analysis . Thus, contrary to some reports, a wild-type norA gene confers fluoroquinolone resistance in E . coli in a copy-number-dependent fashion and does not require mutational activation . Interestingly, a multicopy pUC19norA derivative gave transformants exhibiting a range of resistance phenotypes . The norA gene of one transformant carried a single base deletion (ATACAAT to AACAAT; the deleted base is underlined) in the putative--10 Pribnow box resulting in a promoter down-regulatory mutation; a second plasmid had acquired a frameshift producing a null mutation at codon 112 . These mutations override the dual resistance-growth-inhibitory phenotype of high-copy-number norA plasmids . The results have implications for using the standard E . coli HB101 system to assess NorA function and potentially for plasmid-borne transmission of norA-mediated drug resistance.

Chemotherapy, 1996 Jul-Aug, 42(4), 253 - 8
In vitro antibacterial activity of TOC-50, a new parenteral cephalosporin against methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis; Nomura S et al.; The in vitro activity of TOC-50, a new parenteral cephalosporin, was assessed against methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus epidermidis (MRSE) . TOC-50 showed excellent activity, which was stronger than that of methicillin, cloxacillin, the cephalosporins tested, imipenem, gentamycin, minocycline, ofloxacin and ciprofloxacin against MRSA and had a minimum inhibitory concentration (MIC) comparable to that of vancomycin (the MICs of TOC-50 and vancomycin for growth inhibition of 90% of the strains tested were 3.13 and 1.56 micrograms/ml, respectively) . Against MRSE, TOC-50 exhibited excellent activity, which was stronger than that of methicillin, ampicillin, the cephalosporins tested and imipenem, and was twice as active as vancomycin . In terms of the bactericidal effect against MRSA, TOC-50 was superior to vancomycin.

Chemotherapy, 1996 Jul-Aug, 42(4), 248 - 52
Reduced susceptibility of methicillin-resistant Staphylococcus aureus to cetylpyridinium chloride and chlorhexidine; Irizarry L et al.; Sensitivities of 120 strains of Staphylococcus aureus to methicillin, cetylpyridinium chloride (CPC) and chlorhexidine (CH) were measured by the agar dilution technique . The MICs for CPC and CH were < or = 2 micrograms/ml in 93 and 83% of methicillin-sensitive S . aureus, respectively, and > 2 micrograms/ml in 81 and 83% of methicillin-resistant S . aureus (MRSA), respectively . Overall, the MICs for CPC and CH were 5-10 times greater in the methicillin-resistant than in the methicillin-sensitive strains (p < 0.001) . The MICs for CPC and CH also predicted the relative susceptibilities of S . aureus strains to the bactericidal action of these agents in growth and time-kill studies . The possibility that antiseptics and disinfectants contribute to the selection and maintenance of multiply resistant MRSA is considered.

Br J Clin Pract, 1996 Jul-Aug, 50(5), 237 - 9
Methicillin-resistant Staphylococcus aureus bacteraemia at a tertiary teaching hospital; Cheong I et al.; Between July and December 1994, 25 patients with MRSA bacteraemia were treated at the Hospital Kuala Lumpur, a tertiary hospital in Malaysia with 3000 beds . The patients included 15 males and 10 females whose mean age was 46.7 years (range 13-75) . The sources of their MRSA were: Urology/Nephrology, 11; General ICU, six; Orthopaedic, four; Medicine, three; Surgery, one . Their underlying diseases were: end-stage and chronic renal failure, 11; burns, three; acute necrotising pancreatitis, two; haematological malignancies, two; and one each of fracture of the neck of the femur, pustular psoriasis, alcoholic cirrhosis, liver abscess, peptic ulcer (antrectomy), choledochol cyst, and abdominal aneurysm with gangrene of the legs . Six patients were also diabetic . A total of 19 infections were considered nosocomial . The duration of hospital stay ranged from one to 60 days, mean 16 days . On the day of blood culture, 20 patients (80%) were febrile and 15(60%) had leucocytosis . A total of 14 patients were considered to have received prolonged broad-spectrum antibiotics before the bacteraemia; of these, 11 had had either a third-generation cephalosporin and/or a quinolone . The primary foci of infection were: vascular access dialysis catheters, six; infected AV fistulae, three; non-surgical wounds, five; orthopaedic pin, one; multiple venous lines and catheters, nine; unknown, one . The sensitivities to anti-MRSA antibiotics were: vancomycin, 100%; fusidic acid, 96%; rifampicin, 96%; ciprofloxacin and perfloxacin 28% each . In all, 13 patients (52%) eventually died; nine of these deaths were directly attributed to MRSA bacteraemia . The microbiological eradication rate was 88% . Mortality was significantly associated with duration of hospital stay and failure to remove the infected catheters/peripheral lines after the development of MRSA bacteraemia.

J Pediatr Orthop, 1996 Jul-Aug, 16(4), 518 - 21
Microbiological tolerance in orthopaedic infections: delayed response of septic arthritis and osteomyelitis of the hip due to infection with tolerant Staphylococcus aureus; Thometz JG et al.; A 14-year-old boy presented to another hospital with a clinical picture of septic arthritis . After aspiration of purulent material from the joint, empiric antibiotic treatment was initiated and an arthrotomy was performed . Antibiotic treatment was then modified to nafcillin according to microbiological sensitivity results of the isolated Staphylococcus aureus as determined by minimal inhibitory concentration testing . One week later purulent drainage recurred and open drainage had to be repeated; an abscess anterior to the joint was noted . Once again the infection failed to resolve, and the patient was transferred to our institution where a third arthrotomy had to be performed . The organism isolated at the first aspiration was reexamined and found to have a minimal bactericidal concentration to minimal inhibitory concentration ratio of 32, implying a tolerant organism . The antibiotic treatment was modified to an antibiotic not subject to the tolerance phenomenon, and the infection resolved without additional surgical intervention.

Zentralbl Veterinarmed B, 1996 Jul, 43(5), 313 - 5
A new pathogenic Staphylococcus aureus type in commercial rabbits; Devriese LA et al.; Heavy losses in commercial rabbitries with mainly cutaneous infections were found to be caused by a special Staphylococcus aureus type . This type differs from the previously known rabbit and hare pathogenic strains causing similar infections, mainly in its unique phage type.

Appl Environ Microbiol, 1996 Jul, 62(7), 2356 - 9
The expression of the Photinus pyralis luciferase gene in Staphylococcus aureus Cowan I allows the development of a live amplifiable tool for immunodetection; Steidler L et al.; We expressed the luc gene, encoding luciferase from Photinus pyralis, in Staphylococcus aureus Cowan I downstream of the plasmid-borne promoter for protein A . Constitutive luciferase synthesis did not impair the growth rate of the host nor did it affect the stability of the plasmid . Light production started immediately after addition of luciferin . The kinetic profile is of the glowing rather than the peak type . Because S . aureus Cowan I produces large quantities of protein A, of which a substantial part becomes covalently attached to rigid cell walls, the bacterial cells could be specifically immobilized on a substrate to which immunoglobulin G molecules were adsorbed either directly or as secondary antibodies . Light production from these cells can be used as a reporter tool for the detection of antigen-antibody complexes . Fourfold amplifications of the emitted signals were obtained by in situ incubation of the bound cells in bacterial growth medium.

J Orthop Res, 1996 Jul, 14(4), 663 - 7
Influence of bacterial strains on bone infection; Cordero J et al.; Experiments were performed on 120 rabbits to compare the probability of infection after bone surgery without an implant, with polymethylmethacrylate, and with autografts . Staphylococcus aureus phage type 94/96, isolated from a human osteomyelitis, was instilled into the intramedullar cavity after reaming of the femoral canal and before insertion of the implant . The different 50% infective doses were determined for each of the groups for comparative purposes . The bacterial concentrations required to produce infection in femora without an implant were two times less than those necessary in femora implanted with polymethylmethacrylate . The bone graft required bacterial concentrations nine times less than those necessary to infect femora containing polymethylmethacrylate and four times less than those required to infect femora without an implant . The results presented here confirm that the susceptibility to infection in orthopaedic surgery is not only material dependent but also bacteria dependent.

Mil Med, 1996 Jul, 161(7), 382 - 6
The epidemiology of dermatologic and venereologic disease in a deployed operational setting; Vidmar DA et al.; We studied the epidemiology, morbidity, and etiology of dermatologic and non-human immunodeficiency virus venereologic disease (Derm/STD) aboard a deployed aircraft carrier to revise Derm/STD training objectives for shipboard primary care providers . Onboard supplies for treatment of Derm/STD were also evaluated . Over 3 months, 929 Derm/STD patients were treated for 1,320 diagnoses generating 2,011 visits . Derm/STD caused 22% of the total morbidity . Pyoderma alone accounted for nearly one-half of that morbidity and involved many work-center groups . Air wing, aircraft maintenance, and engineering work-center groups had lower burdens of pyoderma . Bacterial cultures were performed on 248 exudative dermatoses . Staphylococcus aureus was the dominant pathogen and was overwhelmingly sensitive in vitro to common, inexpensive antibiotics . Strategies to encourage prevention, earlier diagnosis, and rapid treatment of Derm/STD by deployed primary care providers are discussed.

Kyobu Geka, 1996 Jul, 49(8 Suppl), 680 - 3
{A case report of an infective endocarditis caused by methicillin-resistant Staphylococcus aureus with successful mitral valve replacement}; Kawahira T et al.; We report a case of successful mitral valve replacement performed on the patient who is an infective endocarditis due to MRSA . She was 27-year-old female and treated by antibiotics medication because of remittent fever two years ago . On August 1995, cerebral infarction occurred and she was pointed out endocarditis . After high fever continued, blood cultures demonstrated MRSA . Furthermore, echocardiography showed vegetation on posterior mitral valve leaflet and moderate mitral regurgitation so, mitral valve replacement with a S.J.M . 25 mm performed to control MRSA sepsis condition . During operation, we used VCM 2 g into the extracorporeal circulation and after operation 0.5 g intravenously every 6 hours . Two weeks later we changed antibiotics to FOM, Viccillin and ABK according to the result of minimum inhibitory concentration (MIC) obtained through blood culture . The patient was discharged on the 44 th postoperative day because of her uneventful postoperative course.

Kyobu Geka, 1996 Jul, 49(8 Suppl), 617 - 20
{Valve replacement concomitant with anulus reconstruction}; Sawazaki M et al.; It is important that surgical treatment of infective endocarditis involves complete debridement of the affected tissue . In case of abscess formation in the mitral anulus and/or aortic root, disruption of the anulus occurs because of radical resection of the abscess . David et al . reported a new technique for mitral and aortic anulus reconstruction . The novel part of the technique was the endocardial repair, i.e., suturing of a pericardial patch to the endocardium of the left ventricle . We were surprised to learn that the left ventricular endocardium and muscle are capable of tolerating the stress induced by the prosthetic ring, especially in the mitral position . Since 1992, we treated eight cases of anulus disruption using this technique ; 5 cases involved the mitral anulus, 1 involved the aortic, and 2 involved both . We used a slightly different technique involving suturing of a patch not only to the left ventricular endocardium but also to left atrial wall for reinforcement . Two patients died in the perioperative period . One had a brain abscess ; the other had methicillin-resistant Staphylococcus aureus sepsis and mediastinitis . There was 1 late (sudden, unknown) death 3 years after the operation . No perivalvular leakage, dehiscence of the patch, hemolysis, prosthetic valve endocarditis, or thromboembolism have been observed in the other 5 patients.

Infect Immun, 1996 Jul, 64(7), 2408 - 14
Respiratory activity is essential for post-exponential-phase production of type 5 capsular polysaccharide by Staphylococcus aureus; Dassy B et al.; Capsule formation is believed to have a significant role in bacterial virulence . To examine the possible involvement of capsular polysaccharide (CP) from Staphylococcus aureus in the pathological mechanisms associated with staphylococcal infections, we investigated the influence of respiratory activity on type 5 CP production by S . aureus grown in the presence of various concentrations of dissolved oxygen or nitrate . The effects of several metabolic inhibitors (arsenite, cyanide, azide, trimethylamine N-oxide, 2-heptyl-4-hydroxyquinoline N-oxide, and 2,4-dinitrophenol) were also tested . The metabolism of the bacteria was estimated by measuring their reductive capacity and by monitoring the pH and concentrations of fermentation products . Type 5 CP was always produced by S . aureus during the exponential phase of growth under all culture conditions tested . In contrast, post-exponential-phase CP production appeared to be strictly dependent on the respiratory activity . Since post-exponential-phase CP production contributes at least two-thirds of the total CP obtained, the influence of S . aureus respiration on CP production might be of some importance in the process of infection.

Infect Immun, 1996 Jul, 64(7), 2371 - 80
Bacterially induced bone destruction: mechanisms and misconceptions; Nair SP et al.; Normal bone remodelling requires the coordinated regulation of the genesis and activity of osteoblast and osteoclast lineages . Any interference with these integrated cellular systems can result in dysregulation of remodelling with the consequent loss of bone matrix . Bacteria are important causes of bone pathology in common conditions such as periodontitis, dental cysts, bacterial arthritis, and osteomyelitis . It is now established that many of the bacteria implicated in bone diseases contain or produce molecules with potent effects on bone cells . Some of these molecules, such as components of the gram-positive cell walls (lipoteichoic acids), are weak stimulators of bone resorption in vitro, while others (PMT, cpn60) are as active as the most active mammalian osteolytic factors such as cytokines like IL-1 and TNF . The complexity of the integration of bone cell lineage development means that there are still question marks over the mechanism of action of many well-known bone-modulatory molecules such as parathyroid hormone . The key questions which must be asked of the now-recognized bacterial bone-modulatory molecules are as follows: (i) what cell population do they bind to, (ii) what is the nature of the receptor and postreceptor events, and (iii) is their action direct or dependent on the induction of secondary extracellular bone-modulating factors such as cytokines, eicosanoids, etc . In the case of LPS, this ubiquitous gram-negative polymer probably binds to osteoblasts or other cells in bone through the CD14 receptor and stimulates them to release cytokines and eicosanoids which then induce the recruitment and activation of osteoclasts . This explains the inhibitor effects of nonsteroidal and anticytokine agents on LPS-induced bone resorption . However, other bacterial factors such as the potent toxin PMT may act by blocking the normal maturation pathway of the osteoblast lineage, thus inducing dysregulation in the tightly regulated process of resorption and replacement of bone matrix . At the present time, it is not possible to define a general mechanism by which bacteria promote loss of bone matrix . Many bacteria are capable of stimulating bone matrix loss, and the information available would suggest that each organism possesses different factors which interact with bone in different ways . With the rapid increase in antibiotic resistance, particularly with Staphylococcus aureus and M . tuberculosis, organisms responsible for much bone pathology in developed countries only two generations ago, we would urge that much greater attention should be focused on the problem of bacterially induced bone remodelling in order to define pathogenetic mechanisms which could be therapeutic targets for the development of new treatment modalities.

Can J Cardiol, 1996 Jul, 12(7), 641 - 4
Bacterial pericarditis after heart transplantation: successful management of two cases with catheter drainage and antibiotics; Davies RA et al.; OBJECTIVE: To describe the diagnosis and management of bacterial pericarditis after heart transplantation . PATIENTS AND METHODS: Two patients with Staphylococcus aureus pericarditis after heart transplantation were successfully treated conservatively with closed catheter drainage and antibiotics . RESULTS: The patients were alive three and six years, respectively, following surgery . At follow-up, right heart catheterization demonstrated normal hemodynamics in one patient and a pattern of constrictive pericarditis in the other patient which was man-aged with furosemide . CONCLUSIONS: Conservative management of bacterial pericarditis by closed catheter drainage and antibiotics can be considered in selected patients after heart transplantation.

J Immunol, 1996 Jul 1, 157(1), 411 - 6
Defective monocyte costimulation for IFN-gamma production in familial disseminated Mycobacterium avium complex infection: abnormal IL-12 regulation; Frucht DM et al.; We have described previously a family in which several members have disseminated Mycobacterium avium complex infection . PBMC from affected members produced abnormally low amounts of IFN-gamma upon stimulation with PHA . Using PHA-stimulated allogeneic cocultures of highly purified monocytes and T cells from familial patients and normal subjects, we have now demonstrated that familial patient monocytes are defective in accessory cell function for IFN-gamma production . Familial patient monocytes did not inhibit IFN-gamma production by normal cells, nor did inhibition of PG synthesis restore normal IFN-gamma production by familial patient cells . Familial patient cells responded to the addition of exogenous IL-12 by increasing IFN-gamma production, while addition of exogenous anti-IL-12 had an insignificant effect on their IFN-gamma production . IL-12 was undetectable in PHA-stimulated cocultures of familial patient monocytes with familial or normal T cells . In addition, IL-12 production by adherent cells from patients and their unaffected mothers was abnormally low following stimulation with fixed Staphylococcus aureus Cowan I strain . However, normal amounts of IL-12 were detected when adherent familial patient cells were stimulated with S . aureus Cowan I strain and IFN-gamma, suggesting abnormal regulation of IL-12 production by familial monocytes . This is the first report of defective IL-12 production associated with increased susceptibility to an infectious disease, a finding that supports the critical role of this cytokine in host defense.

J Bone Joint Surg Br, 1996 Jul, 78(4), 647 - 51
Influence of materials for fixation implants on local infection . An experimental study of steel versus titanium DCP in rabbits; Arens S et al.; Resistance to infection may be influenced by foreign bodies such as devices for fracture fixation . It is known that stainless steel and commercially-pure titanium have different biocompatibilities . We have investigated susceptibility to infection after a local bacterial challenge using standard 2.0 dynamic compression plates of either stainless steel or titanium in rabbit tibiae . After the wounds had been closed, various concentrations of a strain of Staphylococcus aureus were inoculated percutaneously . Under otherwise identical experimental conditions the rate of infection for steel plates (75%) was significantly higher than that for titanium plates (35%) (p < 0.05).

J Appl Bacteriol, 1996 Jul, 81(1), 7 - 18
Inhibitory effects of sucrose monolaurate, alone and in combination with organic acids, on Listeria monocytogenes and Staphylococcus aureus; Monk JD et al.; The effects of sucrose esters of fatty acids, alone and in combination with ethylenediaminetetraacetic acid (EDTA), acetic acid, lactic acid and citric acid, on survival, growth and thermal inactivation of Listeria monocytogenes and Staphylococcus aureus were determined . The presence of sucrose monocaprate (400 micrograms ml-1) in tryptose phosphate broth (TPB) or tryptic soy broth (TSB) did not inhibit the growth of L . monocytogenes or Staph . aureus, respectively . However, significantly (P < or = 0.05) lower populations of L . monocytogenes were detected in TPB containing as little as 100 micrograms ml-1 sucrose monolaurate (SML) during the logarithmic growth phase compared to populations detected in TPB containing no SML . At 400 micrograms ml-1, SML was lethal to L . monocytogenes . Less marked inhibitory effects were observed with Staph . aureus . The addition of EDTA to broth containing SML had a synergistic effect on the inhibition of both organisms . The chelator alone had no effect at 100 micrograms ml-1 on either pathogen but was inhibitory at 200 micrograms ml-1 . Inhibition of L . monocytogenes was more pronounced as the incubation temperature was decreased from 30 degrees C to 15 or 5 degrees C . The addition of 0.1% acetic or lactic acid to TPB minimized the inhibitory effect of 100 and 200 micrograms ml-1 SML during the first 32 h of incubation . Staphylococcus aureus behaved similarly, but not as dramatically, to L . monocytogenes when cultured in TSB supplemented with SML alone or SML and organic acids . A synergistic inhibitory effect of SML and EDTA on heat inactivation of L . monocytogenes was evident but the reverse phenomenon was observed with Staph . aureus . The effectiveness of SML in controlling the growth of L . monocytogenes and Staph . aureus in foods most likely to be contaminated with these pathogens should be further investigated.

J Am Coll Surg, 1996 Jul, 183(1), 19 - 24
Effect of Merocel vaginal sponge on growth of Staphylococcus aureus and production of toxic shock syndrome-associated toxins; Schlievert PM; BACKGROUND: Staphylococcus aureus toxic shock syndrome toxin-1 and enterotoxin B are the major causes of toxic shock syndrome . These toxins are produced in sufficient concentrations to produce illness in the presence of certain tampons . This necessitates evaluating tampons, as well as wound dressings for their effects on S . aureus growth and toxin production . STUDY DESIGN: In this study, the Merocel vaginal sponge was evaluated both in vitro and in vivo in a rabbit model for effect on S . aureus . The Merocel sponge was tested in Erlenmeyer shake flasks containing growth media and in dialysis tubing immersed in agar growth media for both effect on S . aureus plate counts compared to media alone and effect on production of toxic shock syndrome toxins . The in vivo test included placement of Merocel sponges subcutaneously along the flanks of rabbits with subsequent inoculation with toxic shock syndrome bacteria and evaluation for development of illness and death . RESULTS: In the two standard in vitro tests, the shake flask and tampon sac, the Merocel sponge inhibited both growth of toxic shock syndrome S . aureus and production of toxic shock syndrome toxin-1 and enterotoxin B . The Merocel sponge also prevented development of toxic shock syndrome in a rabbit model . CONCLUSIONS: The data suggest the Merocel sponge may reduce the risk of development of toxic shock syndrome in association with its use . These studies may serve as models for evaluation of other products that are intended to be used on mucosal and skin surfaces, for their effect on toxic shock syndrome toxins.

Radiology, 1996 Jul, 200(1), 217 - 8
Air enema for reduction of intussusception in children: risk of bacteremia; Somekh E et al.; PURPOSE: To evaluate the incidence of bacteremia in children undergoing air enema for the diagnosis and reduction of intussusception . MATERIALS AND METHODS: Twenty-seven children who underwent air enema for the diagnosis and treatment of intussusception were evaluated to identify the incidence of transient bacteremia and fever associated with the procedure . Blood cultures were obtained prior to the manipulation (point 0), immediately after completion of the procedure (point 1), and 2 hours later (point 2) . RESULTS: The results of six of 81 sets of blood cultures were positive for bacterial pathogens . Three of them that were obtained at point 0 and two at point 1 grew common skin contaminants . A sixth blood culture drawn at point 1 was positive for Staphylococcus aureus . No patient had more than one positive blood culture result, and all recovered without antimicrobial therapy . Five patients had temperature elevations to > or = 38 degrees C following the enema . Only one of the patients was febrile at admission, and none had positive blood culture results . CONCLUSION: The risk of bacteremia from enteric pathogens following air enema for reduction of intussusception in children appears to be low.

J Infect Dis, 1996 Jul, 174(1), 83 - 8
Collagen binding of Staphylococcus aureus is a virulence factor in experimental endocarditis; Hienz SA et al.; The role of Staphylococcus aureus collagen binding in the development of experimental endocarditis was studied . Two isogenic strains of S . aureus, 1 carrying an insertional inactivation of the gene encoding collagen-binding protein, were compared in a rat model of catheter-induced infective endocarditis (i.e.) . Separate groups of rats with traumatized aortic valves were intravenously challenged with 1 of the strains . In rats sacrificed 24 h after inoculation, the collagen-binding strain significantly outnumbered the mutant strain (P < .001); however, 1 h after challenge, there was no difference in numbers of the 2 strains . The results were substantiated, using a 1:1 mixture of the parent strain and the mutant as an inoculate . Our findings suggest that collagen binding of S . aureus is important in the sustenance of experimental IE and plays a limited role during the initial attachment of the microorganism to traumatized aortic valves.

J Cell Physiol, 1996 Jul, 168(1), 26 - 33
Supplemental L-arginine HCl augments bacterial phagocytosis in human polymorphonuclear leukocytes; Moffat FL Jr et al.; That L-arginine (L-Arg) augments the host response to acute bacterial sepsis suggests that this amino acid intervenes early in the immune response, perhaps via the nitric oxide synthetase (NOS) pathway . The effect of L-Arg supplementation on in vitro phagocytosis of fluorescein-labeled, heat-killed Staphylococcus aureus by peripheral blood neutrophils (PMNs) from 12 normal human volunteers was studied . Separated PMNs were incubated for 2 h with labeled bacteria, with and without supplemental L-Arg, D-arginine, glycine, and/or the NOS inhibitors L-canavanine, aminoguanidine, or L-NG-nitroarginine methyl ester . PMNs were fixed and extracellular fluorescence quenched with crystal violet . By flow cytometry and confocal microscopy, L-Arg supplementation was shown to result in a highly significant increase in PMN bacterial phagocytosis, the maximal effect being seen with L-Arg 380 microM and falling off with higher concentrations . This augmentation was completely abrogated by NOS inhibitors in molar excess, but inhibitors alone did not suppress phagocytosis below that of unsupplemented controls . Neither D-arginine nor glycine affected phagocytosis; the L-Arg effect was stereospecific and not related to utilization of L-Arg as an energy source . L-Arg supplementation significantly enhances bacterial phagocytosis in human neutrophils, perhaps by effects on cytoskeletal phenomena, and this appears to be mediated through NOS activity . Phagocytosis by nonspecific immune cells which intervene early in the response to sepsis is critically important, and beneficial effects of L-Arg on the clinical course of sepsis may be due at least in part to augmentation of phagocyte function.

Med J Aust, 1996 Jun 17, 164(12), 721 - 3
Emerging epidemic of community-acquired methicillin-resistant Staphylococcus aureus infection in the Northern Territory; Maguire GP et al.; OBJECTIVE: To investigate the epidemiology of WA MRSA (the recently recognised Western Australian strains of methicillin-resistant Staphylococcus aureus) in the north of the Northern Territory (NT) . DESIGN: Retrospective survey of data from hospital records . SETTING: Royal Darwin Hospital (a tertiary referral hospital that serves the north of the NT) between January 1991 and July 1995 . Subjects: All inpatients with clinical MRSA infection . OUTCOME MEASURES: Incidence of MRSA infection, classification of MRSA as WA or EA (Eastern Australian) based on antibiotic susceptibility, patient demographic details (age, sex, ethnicity, region of residence), source of infection (nosocomial or community-acquired) . RESULTS: There were 125 WA MRSA and 93 EA MRSA infections, comprising 7% of all S . aureus infections . The incidence of WA MRSA infections consistently increased, while that of EA MRSA initially fell and then increased . All EA MRSA infections were nosocomial, while 50% of WA MRSA infections were community-acquired . Rates of WA MRSA infections were highest in patients from the west region of the NT, adjacent to the Kimberley region of Western Australia (WA) . Community-acquired WA MRSA infections were more likely to affect Aboriginals than non-Aboriginals (relative risk {RR}, 25.86; 95% confidence interval {CI}, 12.51-53.47, based on population data; RR, 15.43; 95% CI, 7.85-30.32, based on admission data), as were nosocomial EA MRSA infections (RR, 2.54; 95% CI, 1.44-4.47, based on population data; RR, 2.30; 95% CI, 1.52-3.46, based on admission data) . CONCLUSIONS: Changes in the epidemiology of MRSA infection in the north of the NT are consistent with the hypothesis that community-acquired WA MRSA spread into and across the NT from the Kimberley region of WA . Alternatively, crowded living conditions, hygiene difficulties and increasing use of broad spectrum antibiotics may have led to independent emergence of WA MRSA in both regions . Current infection control policies and their use in rural Aboriginal communities must be reassessed.

Eur J Biochem, 1996 Jun 15, 238(3), 653 - 60
A recombinant insect-specific alpha-toxin of Buthus occitanus tunetanus scorpion confers protection against homologous mammal toxins; Bouhaouala-Zahar B et al.; We have constructed a cDNA library from venom glands of the scorpion Buthus occitanus tunetanus and cloned a DNA sequence that encodes an alpha-toxin . This clone was efficiently expressed in Escherichia coli as a fusion protein with two Ig-binding (Z) domains of protein A from Staphylococcus aureus . After CNBr treatment of the fusion protein and HPLC purification, we obtained approximately 1 mg recombinant apha-toxin/l bacterial culture . The toxin, called Bot XIV, displays no toxicity towards mammals but is active towards insects as shown by its paralytic activity against Blatella germanica cockroach and by electrophysiological studies on Periplaneta americana cockroaches . The Bot XIV protein fused to two Z domains is highly immunogenic in mice and induces production of antisera that specifically recognize and neutralize highly toxic components that had been injected into mice . This fusion protein could be very useful for development of potent protective antisera against scorpion venoms.

Experientia, 1996 Jun 15, 52(6), 600 - 4
Antibacterial effect of 2-hydroxy-N-(3,4-dimethyl-5-isoxazolyl)-1, 4-naphthoquinone-4-imine on Staphylococcus aureus; Bogdanov P et al.; The mechanism by which a new naphthoquinone derivative, the 2-hydroxy-N-(3,4-dimethyl-5-isoxazolyl)-1, 4-naphthoquinone-4-imine (INQI-E) has antibacterial effect against Staphylococcus aureus was studied . The interaction of INQI-E with the bacteria was followed by absorption spectroscopy at 323 and 490 nm . The absorption band of INQI-E at 490 nm undergoes a hypochromic shift with a decrease of intensity . This effect was found to be reversible by oxygenation during the first hours of incubation . The participation of an oxidation-reduction process related to the respiratory chain was demonstrated by oxygen consumption . An increase in O2 uptake and inhibition of S . aureus growth was observed . Experiments with three inhibitors of the respiratory chain demonstrated that the pathway induced by INQI-E was antimycin-resistant and KCN- and salicylhydroxamic acid (SHAM)-sensitive, which suggests that INQI-E is capable of diverting the normal electron flow to an alternate superoxide-producing route . On the other hand, experiments with Tiron, a specific scavenger of superoxide, hindered the effect of INQI-E against S . aureus, indicating that the inhibitory growth effect of this quinone-imine is mainly due to the production of the cytotoxic superoxide radical.

Blood, 1996 Jun 15, 87(12), 5257 - 68
BCL-6 expression during B-cell activation; Allman D et al.; Translocations involving the BCL-6 gene are common in the diffuse large cell subtype of non-Hodgkin's lymphoma . Invariably, the BCL-6 coding region is intact, but its 5' untranslated region is replaced with sequences from the translocation partner . The present study shows that BCL-6 expression is regulated in lymphocytes during mitogenic stimulation . Resting B and T lymphocytes contain high levels of BCL-6 mRNA . Stimulation of mouse B cells with anti-IgM or IgD antibodies, bacterial lipopolysaccharide, phorbol 12-myristate 13-acetate plus ionomycin, or CD40 ligand led to a five-fold to 35-fold decrease in BCL-6 mRNA levels . Similar downregulation of BCL-6 mRNA was seen in human B cells stimulated with Staphylococcus aureus plus interleukin-2 or anti-IgM antibodies and in human T lymphocytes stimulated with phytohemagglutinin . BCL-6 mRNA levels began to decrease 8 to 16 hours after stimulation, before cells entered S phase . Although polyclonal activation of B cells in vitro invariably decreased BCL-6 MRNA expression, activated B cells from human germinal centers expressed BCL-6 mRNA at levels comparable to the levels in resting B cells . Despite these similar mRNA levels, BCL-6 protein expression was threefold to 34-fold higher in germinal center B cells than in resting B cells, suggesting that BCL-6 protein levels are controlled by translational or posttranslational mechanisms . These observations suggest that the germinal center reaction provides unique activation signals to B cells that allow for continued, high-level BCL-6 expression.

J Immunol, 1996 Jun 15, 156(12), 4952 - 60
Enhanced expression of IL-12 associated with Th1 cytokine profiles in active pulmonary sarcoidosis; Moller DR et al.; Sarcoidosis is a multisystem granulomatous disease of unknown etiology characterized by the expansion of activated oligoclonal CD4+ T cells and macrophages at sites of disease . To investigate the immunopathogenesis of sarcoidosis, we analyzed patterns of cytokine expression in bronchoalveolar lavage cells and fluid from patients with pulmonary sarcoidosis and idiopathic pulmonary fibrosis and from normal volunteers . We found dominant type 1 cytokine expression, with elevated mRNA and protein levels of IFN-gamma, but not IL-4, in sarcoid lung cells and fluid compared with those in normal samples . To define immunoregulatory mechanisms important to this type 1 response, we analyzed the expression of IL-12 and IL-10 in lung cells and fluid . Using semiquantitative PCR, we found significantly higher mRNA expression of the regulated IL-12 p40 subunit, but not IL-10, in sarcoid compared with normal lung cells . Consistent with these observations, strikingly elevated levels of p40 protein were found in sarcoid compared with normal bronchoalveolar lavage fluid . Unstimulated and Staphylococcus aureus-stimulated sarcoid alveolar macrophages produced greater amounts of IL-12 than normal alveolar macrophages when cultured in vitro . We hypothesize that sarcoidosis is a Th1-mediated disease driven by chronic, dysregulated production of IL-12 at sites of disease.

J Immunol, 1996 Jun 15, 156(12), 4543 - 54
Phosphatidylinositol 3-kinase activation in normal human B lymphocytes; Aagaard-Tillery KM et al.; A variety of signals, mediated via either the B cell Ag receptor (BCR), or non-BCR molecules such as CD40 or cytokine receptors, have been shown to be crucial for the regulation of B cell survival, growth, and differentiation . Although it is clear that a variety of signaling pathways can be activated in B cells in a stimulus-dependent manner, it remains unknown whether differential activation of these signaling pathways is the underlying mechanism controlling B cell fate, i.e., growth vs differentiation . Initial studies reported here indicated that stimulation of highly purified peripheral blood B cells with the polyclonal B cell activators Staphylococcus aureus and CD40 ligand (CD40L) resulted in the rapid induction of phosphatidylinositol 3-kinase (PI 3-kinase) activity . Moreover, pretreatment of B cells with wortmannin, a specific inhibitor of PI 3-kinase, resulted in a complete block in induction of PI 3-kinase activity . The effects of wortmannin, as well as a second PI 3-kinase inhibitor, LY294002, on the induction of both B cell growth and differentiation were therefore investigated . Although these PI 3-kinase inhibitors variably inhibited B cell DNA synthesis in a stimulus-dependent manner, both drugs effected a near-complete block of the ability of each of these stimuli to induce Ig production . Furthermore, separation of B cells into naive IgD+ and postswitch IgD- B cells failed to reveal differential sensitivity of these populations to wortmannin . These results suggest that activation of PI 3-kinase, or other wortmannin- and LY294002-sensitive targets, is a crucial event that occurs during the differentiation of normal human B lymphocytes . The differential sensitivity of B cell responses to inhibitors of PI 3-kinase supports the notion that distinct signal transduction pathways are involved in differentiation vs proliferation of normal human B lymphocytes.

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