J Dairy Sci, 1997 Apr, 80(4), 788 - 91 Activity of selected antimicrobial agents against strains of Staphylococcus aureus isolated from bovine intramammary infections that produce beta-lactamase; Watts JL et al.; The activity of selected antimicrobial agents was determined against strains of Staphylococcus aureus that were isolated from bovine intramammary infections and that were positive or negative for beta-lactamase . A total of 107 S . aureus strains (70 that were positive for beta-lactamase and 37 that were negative for beta-lactamase) were used in the study . Production of beta-lactamase was determined using a chromogenic cephalosporin disk method . Minimum inhibitory concentrations (MIC) for each test strain were determined using a commercially available microdilution panel . The following compounds were tested: penicillin, ampicillin, oxacillin, cephapirin, ceftiofur, penicillin plus novobiocin, erythromycin, and pirlimycin . Of the five beta-lactam compounds tested, penicillin and ampicillin were most affected by beta-lactamase activity, but oxacillin, cephapirin, and ceftiofur were not affected . Penicillin plus novobiocin also demonstrated excellent activity against strains of S . aureus that were both positive and negative for beta-lactamase . Erythromycin and pirlimycin demonstrated good activity against the S . aureus strains that were negative for beta-lactamase; 90% of the isolates had an MIC of < or = 0.5 microgram/ml (MIC90) . The MIC90 for erythromycin and pirlimycin for strains that were positive for beta-lactamase was > 64.0 micrograms/ml . However, 8 strains, in addition to producing beta-lactamase, were also resistant to macrolides and lincosaminides . Recalculation of the MIC90 without these 8 strains yielded equivalent values for both erythromycin and pirlimycin with strains that were positive or negative for beta-lactamase (MIC90 < or = 0.5 microgram/ml). J Antimicrob Chemother, 1997 Apr, 39(4), 515 - 8 An evaluation of the bactericidal activity of ampicillin/sulbactam, piperacillin/tazobactam, imipenem or nafcillin alone and in combination with vancomycin against methicillin-resistant Staphylococcus aureus (MRSA) in time-kill curves with infected fibrin clots; Palmer SM et al.; The activity of piperacillin/tazobactam, ampicillin/sulbactam, imipenem and nafcillin alone and in combination with vancomycin was compared with vancomycin monotherapy against MRSA in test-tube time-kill studies and in infected fibrin clots . Bactericidal activity was achieved with all regimens except nafcillin monotherapy in test tubes but only with imipenem/vancomycin and nafcillin/vancomycin in fibrin clots infected with heterogeneous strains . No regimen was effective against the homogeneous strain . These agents may have potential as alternatives to vancomycin in selected infections. J Antimicrob Chemother, 1997 Apr, 39(4), 493 - 8 Effect of combination therapy of rifampicin and azithromycin on TNF levels during a rat model of chronic osteomyelitis; Littlewood-Evans AJ et al.; The purpose of the present study was to evaluate the combination of azithromycin and rifampicin on experimental chronic osteomyelitis due to Staphylococcus aureus . Alterations in bone bacterial titre, activity of tumour necrosis factor (TNF), a cytokine implicated in inflammation-induced bone pathology, and histopathological changes during infection and following antibiotic treatment were evaluated . Rats were infected with S . aureus by direct tibial inoculation and then randomized 56 days after infection to receive saline treatment or a combination of azithromycin and rifampicin (50 mg/kg po and 25 mg/kg sc respectively) once daily for 21 days . The combination of azithromycin and rifampicin was successful as determined by dramatic reduction in bone bacterial counts (approximately log 4 cfu), but regrowth of the organisms occurred suggesting that the duration of treatment was insufficient . TNF alpha mRNA and TNF activity were constantly elevated by approximately 20- and >200-fold, respectively, and remained elevated irrespective of antimicrobial treatment . Bone histology revealed extensive increase in bone turnover in both the infected and antibiotic treated bones with no difference being observed between the groups . This suggests that, in infected bone, the elevated TNF levels observed may be directly related to the bone pathology and both remain largely unchanged despite potent antibiotic therapy. J Antimicrob Chemother, 1997 Apr, 39(4), 477 - 81 In-vitro modelling of the bactericidal activity of teicoplanin versus flucloxacillin as used in surgical prophylaxis, against Staphylococcus aureus; Steer JA et al.; The bactericidal activities of teicoplanin and flucloxacillin in a 50:50 mixture of human serum and Iso-sensitest broth were compared in an in-vitro pharmacokinetic model, at serum concentrations present during surgical prophylaxis . The bactericidal activity of teicoplanin with and without serum was also compared . Six strains of Staphylococcus aureus were tested . The bactericidal rate of teicoplanin in serum was significantly lower than the rate in broth alone . However, there was no significant difference in the bactericidal rates in serum of teicoplanin compared with flucloxacillin, an antibiotic which is commonly used as prophylaxis for certain surgical procedures. Biosci Biotechnol Biochem, 1997 Apr, 61(4), 565 - 72 Molecular biology of the pore-forming cytolysins from Staphylococcus aureus, alpha- and gamma-hemolysins and leukocidin; Tomita T et al.; Staphylococcus aureus is an important opportunistic pathogen . It produces a variety of extracellular proteins, which may play important roles in infections by this bacterium . Staphylococcal alpha-toxin is a pore-forming 33-kDa polypeptide . In the first part of this article, we will refer to the roles of cell membranes in the pore formation by alpha-toxin as well as the molecular dissection of alpha-toxin for understanding its pore-forming nature . Staphylococcal gamma-hemolysin and leukocidin are bi-component cytolysins, which have different cell specificities towards erythrocytes and leukocytes, respectively . We have found that these bi-component cytolysins share a common component . In the second part of this article, we will refer to the current status of knowledge of molecular cloning of the genes coding for gamma-hemolysin and leukocidin, molecular domains of the toxins which decide the cell specificities, and mode of action of these bi-component toxins. Biol Pharm Bull, 1997 Apr, 20(4), 401 - 4 Extraction and purification of effective antimicrobial constituents of Terminalia chebula RETS . against methicillin-resistant Staphylococcus aureus; Sato Y et al.; Examination of the EtOH extract of the fruiting bodies of Terminalia chebula RETZ . led to the isolation of two potent antimicrobial substances against even methicillin-resistant strains of Staphylococcus aureus . On the basis of spectroscopic evidence, the two isolates have been identified as gallic acid and its ethyl ester. J Trop Pediatr, 1997 Apr, 43(2), 103 - 5 Epidemiological aspects of liver abscesses in children in the Western Cape Province of South Africa; Hendricks MK et al.; A high incidence (28 per 100,000 admissions) of liver abscesses is reported in children from the Western Cape Province of South Africa . Of a total of 84 childhood hepatic abscesses over a 10-year period, 51 per cent (43 patients) were primary pyogenic, 30 per cent (25 patients) amoebic, 2 per cent (two patients) Ascaris, and 17 per cent (14 patients) were culture negative . Protein calorie malnutrition was evident in 56 per cent of cases . Amoebic abscesses originated in patients from rural areas, whereas pyogenic abscesses occurred in patients from urban and periurban environments . Staphylococcus aureus was cultured in 85 per cent of pyogenic liver abscesses . Gram negative organisms were identified in four cases of amoebic hepatic abscess where secondary infection occurred . Co-existing parasites of Ascaris lumbricoides and Trichuris trichiura were identified in the stools of 31 per cent of patients . A low (4.8 per cent) mortality is reported for this series. Int Immunol, 1997 Apr, 9(4), 599 - 606 Ligation of MHC class I induces apoptosis in human pre-B cell lines, in promyelocytic cell lines and in CD40-stimulated mature B cells; Wallen-Ohman M et al.; A murine mAb (BAL-1) was previously shown to induce apoptosis when cross-linked on the cell surface of different B acute lymphocytic leukemia (ALL) and pro-myelocytic cell lines . The present study shows that BAL-1 specifically recognizes the MHC class I (MHC-I) . The apoptotic response was not dependent on the epitope specificity, since other anti-MHC-I antibodies, reacting with different monomorphic determinants of the alpha chain or beta 2-microglobulin, also induced apoptosis in these cells . However, external cross-linking of antibodies was strictly required for the apoptotic effect . Among cells originating from mature peripheral blood B cells, anti-CD40-stimulated cells were susceptible to anti-MHC-I-induced apoptosis, whereas B cells activated with Staphylococcus aureus Cowan I (SAC) or with the superantigen staphylococcal enterotoxin A (SEA) were non-responsive . Mature SEA-activated T cells were also resistant to MHC-I-induced apoptosis . In situ terminal deoxynucleotidyl transferase staining of apoptotic cells at various stages during MHC-I-induced cell death revealed that apoptosis occurred predominantly in the G2/M phase of the cell cycle, with the first apoptotic cells appearing after approximately 12 h of incubation . These results suggest a role for MHC-I-mediated apoptosis during differentiation and activation of certain hematopoietic cells. J Appl Microbiol, 1997 Apr, 82(4), 485 - 93 Comparison of type A enterotoxigenic Staphylococcus aureus strains isolated from geographically far distant locations by pulsed field gel electrophoresis; Tsen HY et al.; Staphylococcal enterotoxin A (SEA) is one of the major staphylococcal enterotoxins which may cause food-borne outbreaks . In order to investigate the difference in genomic types and to elucidate the most disseminated strains for enterotoxin A-producing strains of Staphylococcus aureus, a total of 60 SEA Staph . aureus strains isolated from food and clinical samples in Taiwan and 30 strains of the same enterotoxigenic type of strains obtained from geographically far distant locations were compared for their pulsed field gel electrophoresis (PFGE) patterns . The rare cutting endonuclease SmaI generated 10 distinct genome patterns for the 60 local SEA isolates and 15 and eight genome patterns, respectively, for the 20 and 10 SEA strains originally isolated from the USA and other countries . The local isolates are less diverse in genome patterns as compared to the US isolates . Of all these PFGE patterns, a certain pattern, such as pattern 3, is shared by the food and clinical isolates and the local and foreign isolates . Thus, although SEA Staph . aureus strains from geographically far distant locations showed considerable genetic diversity, PFGE pattern 3 strain might be one of the most disseminated strains. J Med Microbiol, 1997 Apr, 46(4), 297 - 306 Genome organisation of Staphylococcus aureus isolates from different populations; El-Adhami W et al.; Isolates from three different Staphylococcus aureus populations were examined for restriction fragment length polymorphisms (RFLPs) of total DNA digested with the endonuclease SmaI . The populations were: community S . aureus isolates collected at random from healthy individuals (38 isolates); methicillin-resistant S . aureus (MRSA) type strains involved in separate outbreaks of infection in Melbourne (1982) and Canberra (1990) (two isolates); and a collection of clinical methicillin-sensitive S . aureus (MSSA) causing hospital infection (20 isolates) . RFLPs with CspI and SmaI and hybridisation analyses of both, showed that the community and the MSSA isolates were not genetically closely related, and, accordingly, they could not be grouped into clusters as seen with the MRSA types . However, a few MSSA isolates were found to be closely related to each other and appeared to be similar to the standard strain S . aureus 8325-4 and to some MRSA types . Although there was substantial variability between the three groups, physical mapping with genomic DNA fragments from the standard strain S . aureus 8325-4 to probe large fragments generated with CspI and SmaI from the chromosomes of selected community and MRSA isolates, demonstrated a well conserved genome organisation between representative isolates from the three groups. Infect Immun, 1997 Apr, 65(4), 1550 - 6 Staphylococcal accessory regulator (sar) in conjunction with agr contributes to Staphylococcus aureus virulence in endophthalmitis; Booth MC et al.; Previous studies showed that an agr mutant strain of Staphylococcus aureus was partially attenuated in virulence compared to a parental strain in experimental endophthalmitis . The purpose of this study was to determine whether the sar locus, either alone or through interactions with agr, contributes to the regulation of virulence in S . aureus endophthalmitis . Experimental endophthalmitis was established by the midvitreous injection of approximately 30 CFU of S . aureus RN6390 or the isogenic attenuated strains RN6911 (agr mutant), ALC136 (sar mutant), and ALC135 (agr sar double mutant) . Unexpectedly, the rate of reduction in electroretinographic B-wave amplitude in eyes infected with strain ALC136 (sar mutant) was not significantly different from the parental strain on postinfection day (PID) 5 (10% retention) . In contrast, ALC135 (agr sar double mutant)-infected eyes retained 73% of preoperative B-wave amplitude on PID 5 . Therefore, unlike agr, a mutation in the sar locus alone does not alter the overall virulence of wild-type S . aureus in experimental endophthalmitis . However, the combined effect of insertional mutations in both the sar and agr global regulators leads to near-complete attenuation of virulence. Infect Immun, 1997 Apr, 65(4), 1536 - 40 Transcriptional regulation of the Staphylococcus aureus collagen adhesion gene, cna; Gillaspy AF et al.; We demonstrate that transcription of the Staphylococcus aureus collagen adhesin gene (cna) is temporally regulated, with expression being highest in exponentially growing cultures and falling to almost undetectable levels as cultures enter the post-exponential-growth phase . The temporal regulation of cna transcription was not affected by mutation of agr . We also demonstrate that the collagen adhesin is expressed by both agr+ and agr-negative S . aureus cells growing in bone. J Am Podiatr Med Assoc, 1997 Apr, 87(4), 153 - 64 PMMA bead versus parenteral treatment of Staphylococcus aureus osteomyelitis; Heard GS et al.; A . rabbit model of Staphylococcus aureus osteomyelitis was used to compare 3 weeks of clindamycin-impregnated polymethylmethacralate (PMMA) bead treatment with 3 weeks of gentamicin-impregnated polymethylmethacralate bead treatment, 4 weeks of parenteral clindamycin treatment, and surgical debridement without any antibiotic treatment . The animals were weighed throughout the course of the experiment and cortical bone and marrow flush specimens were obtained for bacterial culture at the end of therapy . The cortical specimens were bacteria free in 100% (6/6) of the animals receiving parenteral clindamycin, 83% (5/6) of the animals in the clindamycin PMMA group and, none of the animals in the gentamicin PMMA group . The marrow flush specimens were bacteria free in 83% (5/6) of the animals in the parenteral clindamycin group, 67% (4/6) of the animals in the clindamycin PMMA group, and 40% (2/5) of the animals in the gentamicin PMMA group . While these findings are preliminary and further studies with larger numbers of animals are needed, the authors suggest that when PMMA bead therapy is being contemplated, serious consideration should be given to replacing gentamicin with clindamycin in treatment of gram-positive osteomyelitis . Furthermore, incorporation of clindamycin with gentamicin (or tobramycin) should be considered when treating mixed gram-positive and gram-negative osteomyelitis. Pediatr Res, 1997 Apr, 41(4 Pt 1), 547 - 53 High level interleukin-12 production, but diminished interferon-gamma production, by cord blood mononuclear cells; Scott ME et al.; Cell-mediated immunity (CMI) in neonates is relatively deficient when compared with adults . Defects in cytokine production and/or regulation may contribute to heightened susceptibility to infection by intracellular pathogens . The heterodimeric cytokine IL-12 is a key regulator of CMI and inducer of interferon-gamma (IFN-gamma) production . We report here that umbilical cord blood-derived mononuclear cells (MNC) are capable of producing IL-12 (p40 subunit, measured by RIA, and IL-12 p70 heterodimer, by ELISA) at levels comparable to or greater than adult peripheral blood MNC, after stimulation with heat-killed Staphylococcus aureus in 18-h cultures . As in adult MNC, S . aureus induced IL-12 p40 mRNA accumulation in cord blood MNC . IFN-gamma was also produced in the S . aureus-stimulated cultures, in an IL-12-dependent manner, but cord blood MNC produced 5-fold lower levels of IFN-gamma compared with adult MNC (p < 0.05) . Preincubation with IL-10 inhibited IL-12 p40 production by cord blood and adult peripheral blood MNC in a dose-dependent fashion, whereas neutralization of endogenous IL-10 enhanced IL-12 and IFN-gamma levels . The results demonstrate that the relative CMI deficiency in neonates is not due to an intrinsic defect in the capacity of neonatal MNC to produce IL-12 . The underlying factors responsible for diminished IFN-gamma production are not known, but may lie in the balance of stimulatory and inhibitory signals delivered to the IFN-gamma secreting cells along with IL-12, or may relate more to the absence of memory T cells among cord blood MNC. J Bacteriol, 1997 Apr, 179(8), 2651 - 7 Transcription analysis of the Staphylococcus aureus gene encoding penicillin-binding protein 4; Domanski TL et al.; The high level of cross-linking found in Staphylococcus aureus peptidoglycan is dependent on the low-molecular-weight penicillin-binding protein PBP4 . Recently, the PBP4 gene, pbpD, was cloned and shown to be adjacent to and divergently transcribed relative to the putative ABC-type transporter gene, abcA . Disruption of abcA (in strain KB400) was previously shown to result in heightened resistance to several antibiotics known to interact with PBP4, suggesting that the regulation of pbpD is affected by abcA . In this report, this hypothesis was confirmed by use of a Northern (RNA) blot analysis which revealed increased accumulation of pbpD-specific transcripts in KB400 compared to that in the wild-type strain, 8325-4 . By using reverse-phase high-performance liquid chromatography to examine the structure of the peptidoglycan, it was demonstrated that the increased expression of pbpD resulted in an increased level of peptidoglycan cross-linking in the staphylococcal cell wall . Promoter fusion studies demonstrated that the abcA mutation caused approximately 7-fold and 100-fold increases in pbpD and abcA promoter activities, respectively . Primer extension experiments revealed that these genes have long, untranslated leader sequences that result in a transcriptional overlap of 80 bp . Interestingly, deletion of a 26-bp region containing an inverted repeat sequence resulted in the loss of expression from both the abcA and the pbpD promoters . These data provide evidence that abcA and pbpD are under the control of a common regulatory mechanism that may involve the transport function of the abcA gene product. J Bacteriol, 1997 Apr, 179(8), 2557 - 66 Inhibition of cell wall turnover and autolysis by vancomycin in a highly vancomycin-resistant mutant of Staphylococcus aureus; Sieradzki K et al.; A highly vancomycin-resistant mutant (MIC = 100 microg/ml) of Staphylococcus aureus, mutant VM, which was isolated in the laboratory by a step-pressure procedure, continued to grow and synthesize peptidoglycan in the presence of vancomycin (50 microg/ml) in the medium, but the antibiotic completely inhibited cell wall turnover and autolysis, resulting in the accumulation of cell wall material at the cell surface and inhibition of daughter cell separation . Cultures of mutant VM removed vancomycin from the growth medium through binding the antibiotic to the cell walls, from which the antibiotic could be quantitatively recovered in biologically active form . Vancomycin blocked the in vitro hydrolysis of cell walls by autolytic enzyme extracts, lysostaphin and mutanolysin . Analysis of UDP-linked peptidoglycan precursors showed no evidence for the presence of D-lactate-terminating muropeptides . While there was no significant difference in the composition of muropeptide units of mutant and parental cell walls, the peptidoglycan of VM had a significantly lower degree of cross-linkage . These observations and the results of vancomycin-binding studies suggest alterations in the structural organization of the mutant cell walls such that access of the vancomycin molecules to the sites of wall biosynthesis is blocked. Clin Exp Immunol, 1997 Apr, 108(1), 138 - 43 Production of interleukins 10 and 12 by peripheral blood mononuclear cells (PBMC) in chronic hepatitis C virus (HCV) infection; Kakumu S et al.; We previously reported that interferon-gamma (IFN-gamma) production by PBMC in response to HCV core protein was increased in patients with type C chronic liver disease . To understand better the pathophysiology of this disease, we evaluated production of IL-10 and IL-12 by PBMC from 41 patients with chronic HCV infection, including asymptomatic HCV carriers with persistently normal serum ALT values . IL-10 is known to inhibit many effector functions of the immune system, suppressing Th1-type cell development, while IL-12 stimulates differentiation of Th1-type cells, facilitating cell-mediated immunity . IL-10 production was determined by culturing lymphocytes with concanavalin A (Con A), while IL-12 was produced by monocytes in the presence of Staphylococcus aureus Cowan 1 (SAC) with or without recombinant HCV core protein, respectively . The cytokine levels in culture supernatants were measured by ELISA . Spontaneous IL-10 production was greater in patients with chronic hepatitis (CH) (229 +/- 119 pg/ml, P < 0.01) and liver cirrhosis (LC) (185 +/- 88 pg/ml, P < 0.05) than in controls (119 +/- 27 pg/ml), while it was decreased during IFN treatment (70 +/- 25 pg/ml) . Both HCV core protein and Con A enhanced IL-10 production by cells from HCV-infected patients . IL-12 was not detectable in medium alone cultures, and SAC-induced IL-12 production did not differ between various patient groups and controls . Simultaneous addition of HCV protein resulted in an increase of IL-12 production in chronic liver disease compared with SAC-alone cultures . Addition of IL-10 to the cultures equally suppressed IFN-gamma production for both controls and patient groups, but the enhancing effect of IL-12 on IFN-gamma production was significantly less in LC than in controls and other patient groups . The findings suggest that secretion of IL-10/IL-12 by cells from control individuals and various patient groups may be different, and that the cytokines might show different effects on IFN-gamma production by some cells. J Invest Dermatol, 1997 Apr, 108(4), 488 - 94 T-cell proliferation to superantigen-releasing Staphylococcus aureus by MHC class II-bearing keratinocytes under protection from bacterial cytolysin; Tokura Y et al.; Skin colonization with Staphylococcus aureus may exacerbate skin disorders by activation of lesional T cells with release of superantigens . Although T cells are effectively stimulated by staphylococcal superantigens in the presence of epidermal accessory cells, it remains to be elucidated whether in vivo cutaneous colonization with S . aureus can activate T cells . We examined how T cells are stimulated in the presence of keratinocytes by mitomycin C (MMC)-treated S . aureus that are unable to propagate but retain their ability to produce superantigens . Peripheral blood mononuclear cells (PBMCs) proliferated well in response to MMC-treated superantigen-producing S . aureus and bacterial supernatants . When purified T cells were cultured with MMC-treated S . aureus or supernatant in the presence of interferon-gamma-pre-treated keratinocytes, the supernatant, but not MMC-treated S . aureus, stimulated T cells . MMC-treated S . aureus had a cytotoxic effect on keratinocytes . Furthermore, keratinocytes were highly susceptible to alpha-toxin compared with monocytes and B cells functioning as accessory cells in PBMCs . This suggests that a lack of response of T cells to S . aureus plus keratinocytes is due to damage of superantigen-presenting function of keratinocytes by cytolysin . The activity of alpha-toxin was much less stable than that of superantigen during incubation . Given that S . aureus-colonized skin provides circumstances in which viable keratinocytes are exposed to superantigens but not to active cytolysin(s), skin-infiltrating T cells may be effectively stimulated by S . aureus. Schweiz Med Wochenschr, 1997 Mar 22, 127(12), 471 - 8 {Inter- and intrahospital transmission of methicillin-resistant Staphylococcus aureus}; Harbarth S et al.; Occurrence and spread of methicillin-resistant Staphylococcus aureus (MRSA) has become a major problem worldwide . The majority of hospitals in Switzerland have not so far been affected by this epidemic . We report two out-breaks of MRSA transmission in the surgical intensive care unit at the University Hospital of Geneva and show the possible inter- and intrahospital dissemination of MRSA . Evidence for cross-infection is confirmed by epidemiological investigation and molecular typing . Infection control measures and general precautions are necessary to halt further spread of MRSA. Pediatr Surg Int, 1997 Mar 21, 12(2/3), 213 - 4 Psoas abscess associated with renal pathology in children Driver CP, Renshaw PR, Youngson GG. Pyogenic psoas abscess in children is most commonly a primary disease process associated with Staphylococcus aureus . We report three cases of secondary psoas abscess associated with underlying renal pathology. Pediatr Surg Int, 1997 Mar 21, 12(2/3), 108 - 12 Specific and nonspecific lymphadenitis in childhood: etiology, diagnosis, and therapy Beiler HA, Eckstein TM, Roth H, Daum R. Over a period of 4 years, 39 children with lymphadenitis were treated surgically; in 31 cases cervical lymph nodes were the main location . In 9 cases the lymphadenitis was caused by mycobacterial infection . Staphylococcus aureus was the most frequent causative organism of unspecific lymphadenitis (11 cases) . The therapy of choice appears to be surgical treatment and medical care after operation . Especially in mycobacterial lymphadenitis, complete surgical excision of the lymph node is decisive for definitive healing . There was only 1 case of therapy-resistant, relapsing cervical lymphadenitis that needed a second operation . Causative organisms in this case were Mycobacterium avium and Mycobacterium intracellulare . All other patients showed an uneventful postoperative clinical course . We believe that a consequent diagnostic process and cooperation between the pediatric surgeon and pediatrician are necessary for effective therapy. J Exp Med, 1997 Mar 17, 185(6), 993 - 1004 Soluble and membrane-bound forms of signaling lymphocytic activation molecule (SLAM) induce proliferation and Ig synthesis by activated human B lymphocytes; Punnonen J et al.; In this study it is shown that both membrane-bound and soluble forms of signaling lymphocytic activation molecule (SLAM) induce proliferation and Ig synthesis by activated human B cells . Activated B cells express the membrane-bound form of SLAM (mSLAM), the soluble (s) and the cytoplasmic (c) isoforms of SLAM, and the expression levels of mSLAM on B cells are rapidly upregulated after activation in vitro . Importantly, recombinant sSLAM and L cells transfected with mSLAM efficiently enhance B cell proliferation induced by anti-mu mAbs, anti-CD40 mAbs or Staphylococcus aureus Cowan I (SAC) in the presence or absence of IL-2, IL-4, IL-10, IL-12, or IL-15 . sSLAM strongly enhances proliferation of both freshly isolated B cells and B cells derived from long-term in vitro cultures, indicating that SLAM acts not only during the initial phase of B cell activation but also during the expansion of preactivated B cells . In addition, sSLAM enhances production of IgM, IgG, and IgA by B cells activated by anti-CD40 mAbs . SLAM has recently been shown to be a high affinity self-ligand, and the present data suggest that signaling through homophilic SLAM-SLAM binding during B-B and B-T cell interactions enhances the expansion and differentiation of activated B cells. J Clin Invest, 1997 Mar 15, 99(6), 1445 - 52 Altered responses of human macrophages to lipopolysaccharide by hydroperoxy eicosatetraenoic acid, hydroxy eicosatetraenoic acid, and arachidonic acid . Inhibition of tumor necrosis factor production; Ferrante JV et al.; The regulation of allergic and autoimmune inflammatory reactions by polyunsaturated fatty acids and their metabolic products (eicosanoids) continues to be of major interest . Our data demonstrate that arachidonic acid 5,8,11,14-eicosatetraenoic acid (20:4n-6) and its hydroxylated derivatives 15(s)-hydroxy-5,8,11,13-eicosatetraenoic acid (15-HETE) and 15(s)-hydroperoxy-5,8,11,13-eicosatetraenoic acid (15-HPETE) regulate agonist-induced tumor necrosis factor alpha (TNF) production, a cytokine that plays a role in inflammatory diseases . Although 20:4n-6 and 15-HETE caused a reduction in production of TNF in mononuclear leukocytes stimulated with phytohaemagglutinin, pokeweed mitogen, concanavalin A, and Staphylococcus aureus, 15-HPETE was far more active . 15-HPETE was also found to dramatically depress the ability of bacterial lipopolysaccharide to induce TNF production in monocytes and the monocytic cell line Mono Mac 6 . These fatty acids depressed the expression of TNF mRNA in Mono Mac 6 cells stimulated with LPS; 15-HPETE was fivefold more active than 20:4n-6 and 15-HETE . While 15-HPETE treatment neither affected LPS binding to Mono Mac 6 cells nor caused a decrease in CD14 expression, the fatty acid significantly reduced the LPS-induced translocation of PKC (translocation of alpha, betaI, betaII, and epsilon isozymes), suggesting that 15-HPETE acts by abrogating the early signal transduction events . The findings identify another molecule that could form the basis for development of antiinflammatory pharmaceuticals. J Membr Biol, 1997 Mar 15, 156(2), 157 - 72 Influence of Cys-130 S . aureus alpha-toxin on planar lipid bilayer and erythrocyte membranes; Krasilnikov OV et al.; Replacement of an amino acid residue at position 130 -Gly by Cys- in the primary structure of Staphylococcus aureus alpha-toxin decreases the single-channel conductance induced by the toxin in planar lipid bilayers . Concomitantly, the pH value at which the channel becomes unable to discriminate between Cl- and K+ ions is also decreased . By contrast, the pH dependence of the efficiency of the mutant toxin to form ion channels in lipid bilayers was unchanged (maximum efficiency at pH 5.5-6.0) . The asymmetry and nonlinearity of the current-voltage characteristics of the channel were increased by the point mutation but the diameter of the water pore induced by the mutant toxin, evaluated in lipid bilayers and in erythrocyte membranes, was found to be indistinguishable from that formed by wild-type toxin and equal to 2.4-2.6 nm . Alterations at the "trans mouth" were found to be responsible for all observed changes of the channel properties . This mouth is situated close to the surface of the second leaflet of a bilayer lipid membrane . The data obtained allows us to propose that the region around residue 130 in fact determines the main features of the ST-channel and takes part in the formation of the trans entrance of the channel. Nurs Stand, 1997 Mar 12, 11(25), 58, 61 - 2 Methicillin resistant Staphylococcus aureus; Dunford CE; Methicillin-resistant Staphylococcus aureus (MRSA) has had a major impact on health care causing much anxiety and distress to patients and staff, and resulting in huge financial costs . It has been widely publicised by the media which in some cases has added to people's alarm . The screening, treatment and resultant isolation affects all aspects of the patient's care and will also influence the management of any wounds . MRSA has been isolated in both acute and chronic wounds and so the management of these must be included in any infection control policy. Tumori, 1997 Mar-Apr, 83(2), 618 - 20 Tuberculous skeletal muscle involvement in acute leukemia: report on two cases; del Giglio A et al.; Bacterial infection of skeletal muscle (pyomyositis) is usually followed by abscess formation . The most commonly isolated pathogen is Staphylococcus aureus . Tuberculosis rarely affects patients with acute leukemia . The authors report on 2 patients, one with acute myelogenous leukemia and the other with acute lymphoblastic leukemia whose clinical course was complicated by tuberculous skeletal muscle abscesses . In both instances, musculoskeletal pain was accompanied by evidence of muscle abscesses by imaging studies of the painful areas . Therefore, in patients with acute leukemia and evidence of muscle abscesses with initial cultures negative for bacteria and fungi, one should include tuberculosis in the differential diagnosis. Chirurg, 1997 Mar, 68(3), 264 - 8; discussion 269-70 {Effectiveness of alcoholic hand disinfectants against methicillin resistant Staphylococcus aureus}; Kampf G et al.; In order to determine the efficacy of hand disinfectants based on alcohol against three MRSA strains and 3 methicillin-susceptible S . aureus strains (MSSA), 1-propanol (60%) as well as Sterillium and Spitaderm were investigated in the quantitative suspension test at various dilutions and reactions times (15, 30 and 60s) . All undiluted disinfectants revealed reduction factors > 6 against MRSA and MSSA after 30s . Diluted disinfectants (50%) were significantly less effective against MRSA at short reaction times (15 s) (p < 0.05) . Sterillium in a dilution of 50% did not reach 5 reduction factors against either MRSA or MSSA after 30 s . The impact of an appropriate use of hand disinfectants in order to break chains of infections with MRSA is obvious. J Nihon Univ Sch Dent, 1997 Mar, 39(1), 12 - 6 Effects of nonopsonized Escherichia coli on myeloperoxidase activity in medium used for incubation of leukocytes from patients with gingivitis and periodontitis; Zekonis J et al.; An attempt was made to explore the myeloperoxidase (MPO) activity in medium used for incubation of peripheral venous blood (PVB) leukocytes from patients with gingivitis and periodontitis and to compare it with that of periodontally healthy subjects . The study population included 54 gingivitis patients (G), 52 periodontitis patients (P) and 52 control subjects (C) . All these groups were assessed by clinical, laboratory and statistical methods . The leukocytes were incubated with opsonized zymosan, Escherichia coli ATCC25922, nonopsonized E.coli or Staphylococcus aureus 256 . The respective levels of MPO activity in incubation media of PVB leukocytes taken from group G patients were 598.0 +/- 29.2 conventional units (c.u.), 640.0 +/- 26.3 c.u., 662.0 +/- 37.6 c.u . and 750.0 +/- 40.8 c.u . (control incubation medium: 564.0 +/- 25.1 c.u.); those for group P patients were 672.0 +/- 34.3 c.u., 678.0 +/- 43.1 c.u., 692.0 +/- 47.9 c.u . and 762.0 +/- 34.7 c.u . (control: 612.0 +/- 35.2 c.u.); those for group C subjects were 556.0 +/- 30.2 c . u., 714.0 +/- 28.2 c.u., 1276.0 +/- 69.0 c.u . and 794.0 +/- 47.1 c.u . (control: 534.0 +/- 29.0 c.u.) . MPO activity was increased most significantly when nonopsonized E.coli was added to the incubation medium of PVB leukocytes taken from subjects with intact periodontium . MPO activity was unchanged when the leukocytes were taken from periodontitis patients. East Afr Med J, 1997 Mar, 74(3), 203 - 4 Experience with methicillin resistant Staphylococcus aureus at the Nairobi Hospital; Hayanga A et al.; The problem of MRSA was recognised in mid year of 1996 among both in and out patients at the Nairobi Hospital . The Infection Control Committee, through the microbiology section of the laboratory, immediately accelerated the surveillance programme which included culturing all the wards, beddings, sinks, utensils, furniture and staff . The source was identified and disinfectant methods were modified to eradicate the infection from the community . Relentless fight against the micro-organism through the recommended methods resulted in no more cases at the end of the year . Nosocomial infections must be recognised by all hospitals which must have viable infection control programmes . The Nairobi hospital has an active and on-going infection control programme which enabled this problem to be identified and solved in a timely manner. East Afr Med J, 1997 Mar, 74(3), 198 - 202 Review of methicillin resistant Staphylococcus aureus with special reference to handling of surgical patients; Gakuu LN; If used rationally, antibiotics can cure most bacterial infections . However, there is an increasing tendency globally for bacteria to become resistant to antibiotics . In Kenya, the occurrence of methicillin resistant Staphylococcus aureus(MRSA) is becoming increasingly prevalent . Penicillin, despite its narrow antibacterial spectrum, is still widely used in developing countries in prophylaxis as well as in curative settings . In surgical patients, antibiotic resistance is seen in: patients who are immunosuppressed, patients who have extensive burns and compound fractures, patients requiring prolonged hospital stay and those with malnutrition and low serum albumen levels . Various forms of theatre inadequacies may also result into antibiotic resistance . There are many methods of controlling the spread of MRSA and they should be put into place in surgical units with the assistance of infection control units . This paper is a review of MRSA as regards its history, prevalence, modes of transmission, surveillance, control measures, treatment and implications for both health care workers and patients. East Afr Med J, 1997 Mar, 74(3), 174 - 6 Experiences and studies on antimicrobial resistance in Japan: useful lessons for developing countries; Kamiya Y; The use of antimicrobial drugs in Japan is remarkably high . In 1994, the total production cost of antimicrobial drugs amounted to 3.38 billion US dollars . The intensive use of broad-spectrum drugs, especially for treatment of increasing number of immunocompromised and elderly patients, resulted in the emergence and spread of antimicrobial-resistant organisms in Japan . A bacteriological study in a chronic care centre shows a variety of bacterial pathogens with increased antimicrobial resistance such as methicillin-resistant Staphylococcus aureus . Control measures of nosocomial infections with resistant organisms have been established and strengthened . This includes surveillance researches such as re-evaluation of disinfectants. East Afr Med J, 1997 Mar, 74(3), 166 - 70 Community acquired bacterial infections and their antimicrobial susceptibility in Nairobi, Kenya; Malonza IM et al.; The purpose of the study was to determine the pattern and antimicrobial sensitivity on community acquired bacterial strains in Nairobi, Kenya . Clinical specimens collected from out-patient clinics at the Kenyatta National Hospital were cultured on appropriate media and identified according to Cowen and Steel's manual . The antimicrobial sensitivity was determined using comparative disc diffusion techniques . Between 1991 and 1995, there were a total of 1659 positive cultures comprising 30 different bacterial species . Out of the overall gram negative isolates (61.9%), E.coli and Klebsiella spp formed over 70% . Among the gram positive, Staphylococcus aureus, Enterococcus and coagulase negative staphylococcus spp constituting 41%, 26% and 18% respectively were the most common . Most organisms showed multiple resistance patterns to commonly used antimicrobials similar to hospital acquired infections . The gram negative isolates were resistant to cotrimoxazole, ampicillin, tetracyclines, chloramphenicol, and sulphamethoxazole . However, the sensitivity of these organisms to gentamicin and kanamycin was between 60 and 90% . Among the gram positive isolates, there was a high resistance to penicillin and tetracyclines (60-90%) while the resistance to lincomycin, minocycline and chloramphenicol was low (5-50%) . All isolates were, however, highly sensitive to cephalosporins and fluoroquinolones . Beta-lactamase production among, E.coli, Klebsiella spp and Staphylococcus aureus was 48.9%, 76.7%, 76.1% respectively . Methicillin resistance for Staphylococcus aureus was 59.2% . Indiscriminate use of antibiotics in the community may have selected for resistant strains . This calls for urgent need to review policies on prescription practices. East Afr Med J, 1997 Mar, 74(3), 134 - 7 Pattern of bacterial infections and antimicrobial susceptibility at the Kenyatta National Hospital, Nairobi, Kenya; Omari MA et al.; To monitor clinically significant isolates and their antimicrobial susceptibilities, all specimens sent to microbiology laboratory of the Kenyatta National Hospital were cultured on appropriate media . The susceptibility of the isolates was performed on Muller Hinton or diagnostic sensitivity test (DST) agar using comparative discs diffusion technique . The results were then entered into Microbe Base 2 computer programme . A total of 7416 clinically significant isolates were collected from 1991 to 1995 . The most commonly isolated organisms were E.coli, Klebsiella and Staphylococcus aureus . Most of these hospital acquired infections had multiple resistance to conventional antimicrobials, namely, penicillin, tetracyclines, gentamicin, trimethoprim/sulphamethoxazole and ampicillin . The resistance pattern was high among both gram negative and positive bacteria isolates . Beta-lactamase production amongst them were 51%, 69.3%, 79.6% respectively . Prevalence of methicillin resistant Staphylococcus aureus was 39.8% . Addition of clavulanic acid to amoxycillin increased Staphylococcus aureus susceptibility three fold . The emergence of multiple drug resistance calls for a continuous monitoring and reviewing of antibiotic policy in the hospital and the country at large. Ann Trop Paediatr, 1997 Mar, 17(1), 15 - 20 Multi-resistant Staphylococcus haemolyticus in a neonatal unit in New Delhi; Mehta G et al.; We describe a cluster of infections in a neonatal nursery due to an infrequently reported staphylococcal species, Staphylococcus haemolyticus . S . haemolyticus resistant to penicillin, methicillin, gentamicin, erythromycin, chloramphenicol and tetracycline (PMGECT) was isolated from a series of infections in neonates (conjunctivitis 6, blood 2, pustules 2) over a period of 3 weeks in a neonatal nursery . Surveillance cultures from 22 neonates, their mothers in an adjacent maternity ward and staff revealed that S . haemolyticus with three resistance patterns (PMGECT, PMG and PME) was circulating in the unit . It was isolated from two caesarian wounds, the nose/ear/umbilicus of six asymptomatic infants and from the noses of three mothers and one nurse . S . haemolyticus showed a higher frequency of resistance to antibiotics than Staphylococcus aureus and Staphylococcus epidermidis isolated from the unit at the same time . Local and asymptomatic infections were treated with local neosporin application whereas netilmicin was used to treat systemic infection . Infections were controlled by emphasising the importance of handwashing, asepsis and eye care. Panminerva Med, 1997 Mar, 39(1), 56 - 60 Bilateral acute suppurative parotitis due to Staphylococcus aureus: an hospital acquired case with fatal outcome; Manfredi R et al.; During recent decades, acute bacterial parotitis has progressively changed its etiological and clinical spectrum . New risk factors and causative agents are emerging, while the associated rates of complications and mortality may remain still significant . A rare case of concurrent bilateral suppurative parotitis caused by Staphylococcus aureus has been observed in a patient hospitalized for prior abdominal surgery and multiple underlying illnesses . The disease had a complicated and ultimately fatal outcome, despite a timely diagnosis being made and a specific treatment started . A literature review dealing with risk factors, microbiology, clinical picture, complications, differential diagnosis, treatment and outcome of suppurative parotitis is presented. Br J Biomed Sci, 1997 Mar, 54(1), 10 - 2 Monitoring outbreaks of methicillin-resistant Staphylococcus aureus: use of a commercial database and personal computer; Allen JL et al.; A commercial database and personal computer were used to record relevant information on outbreaks of hospital infection associated with methicillin-resistant Staphylococcus aureus (MRSA) . The data were easily stored, amended and retrieved, and there was sufficient flexibility and capacity within the data fields to allow day-to-day monitoring of the outbreak. Boll Chim Farm, 1997 Mar, 136(3), 244 - 9 Synthesis and biological activity of nifuroxazide and analogs; Tavares LC et al.; Nifuroxazide and thirteen analogs were synthesized from substituted benzoic acids and minimal inhibitory concentrations were determined using the serial dilution tests, in three sequential steps . Nifuroxazide and chloramphenicol were used as reference standards . The tests were performed in TSB against the standard bacterial strain of Staphylococcus aureus ATCC 25923. J Clin Pathol, 1997 Mar, 50(3), 257 - 8 Comparison of methods for the isolation of methicillin resistant Staphylococcus aureus; Davies S et al.; The control of methicillin resistant Staphylococcus aureus (MRSA) relies on the rapid and sensitive detection of carriage . The roles of an enrichment broth, duration of incubation, and Baird-Parker medium containing ciprofloxacin (BPC) were evaluated in comparison with standard media in a centre where the prevalence of ciprofloxacin resistance among MRSA is over 98% . Screening swabs from 402 sites were plated onto BPC, mannitol salt agar (MSA), and MSA with methicillin (MMSA) . The swabs were enriched in Tryptone-T broth with 6% salt for 24 hours and the broths subcultured onto BPC, MSA, and MMSA . MRSA was isolated from 134 swabs . Significantly more isolates were obtained by incubating culture plates for 42 hours rather than 18 hours, by the use of broth enrichment, and by addition of methicillin or ciprofloxacin to media . BPC was the most sensitive medium (107 isolates (80%) by direct culture at 42 hours), grew the fewest contaminants, and allowed provisional reporting of 73% of isolates at 18 hours by colonial appearance and use of Staphaurex Plus rapid latex reagent . This may allow the introduction of infection control measures a day earlier than when other established methods are used. Natl Med J India, 1997 Mar-Apr, 10(2), 61 - 2 In vitro activity of netilmicin against clinical isolates of methicillin resistant and susceptible Staphylococcus aureus; Manoharan A et al.; BACKGROUND: The emergence of methicillin-resistant Staphylococcus aureus and its multidrug-resistant property has led to the search for an effective antibiotic to combat staphylococcal sepsis . At present, vancomycin remains the most effective antibiotic . This study evaluated the in vitro efficacy of netilmicin (an aminoglycoside) and compared its activity with 4 other antibiotics, viz . vancomycin, amikacin, tobramycin and ofloxacin . METHODS: The minimum inhibitory concentration of the antibiotics was determined by the agar dilution method . Thirty strains each of methicillin-resistant and -susceptible S . aureus isolated from pus and blood cultures were included . RESULTS: The susceptibility to netilmicin was found to be 100% and was the same as that observed for vancomycin . CONCLUSION: All the methicillin-resistant S . aureus strains tested showed 100% susceptibility to netilmicin, suggesting its use in patients with such infections as an alternative to vancomycin . However, this finding needs to be verified in the clinical setting. Mech Ageing Dev, 1997 Mar, 94(1-3), 7 - 16 Evidence of enhanced type 2 immune response and impaired upregulation of a type 1 response in frail elderly nursing home residents; Castle S et al.; Peripheral blood mononuclear cells (PBMC) of frail elderly nursing home residents had significantly higher PHA-induced interleukin-10 (IL-10) production compared to PBMC's from young control subjects . No correlation was observed between IL-10 production and interleukin-12 (IL-12) p40 production, proliferative response or with the proportion of CD28-negative T cells . To better characterize the host response to a ubiquitous pathogen, the dose response and time-dependent (kinetic) production of IL-10 and IL-12 p40 of PBMC stimulated with Staphylococcus aureus Cowan (SAC) was studied . IL-10 production continued to increase at 48 h, while IL-12 p40 levels declined or remained stable, in both young and elderly subjects . In analyzing how excessive IL-10 production might influence antigen presenting cell functions, IL-12 was markedly inhibited by recombinant IL-10 (rIL-10), while anti-IL-10 enhances IL-12 p40 production in cultures from young controls; but the PBMC cultured from an elderly cohort were not able to generate similar absolute levels of IL-12 p40 even in the presence of anti-IL-10 . These preliminary data suggest that there may be both over production of IL-10 in some individuals, as well an an impaired ability to upregulate a T Helper 1 (type 1) reaction . These age-related changes could even be more dramatic at the tissue level and contribute to the impaired delayed type hypersensitivity (DTH) and failed host defense to infection, such as to primary and reactivation tuberculosis. Pediatr Dermatol, 1997 Mar-Apr, 14(2), 131 - 43 Diagnosis and treatment of pustular disorders in the neonate; Van Praag MC et al.; The diagnosis of a pustular dermatosis occurring during the first months of life is usually based on clinical findings . However, some cases may require simple investigations including microscopic examination of pustular content, cultures, and skin biopsies . The main benign transient neonatal types of pustulosis include erythema toxicum neonatorum, infantile acropustulosis, transient neonatal pustular melanosis, and neonatal acne . The most common causes of infectious pustular skin lesions include bacterial infections, which may be initially localized (Staphylococcus aureus) or septicemic (with Listeria monocytogenes as the leading causitive agent); viral infections (herpes simplex, varicella-zoster, and cytomegalovirus infections); fungal infections (candidiasis); or parasitic disorders (scabies) . The main objective of this article is to propose a systematic approach to pustular eruptions in the neonate . The need for investigating every neonate with pustules for an infectious disease is emphasized . The Tzanck smear, the Gram's stain, and a potassium hydroxide preparation are the most important quick diagnostic tests . The Tzanck smear is a very easy, rapid, and sensitive test for detection of a herpetic infection (multinucleated giant cells) as well as noninfectious pustular eruptions (eosinophils, neutrophils) . Therefore the Tzanck smear should be the first test performed . Moreover, a Gram's stain and potassium hydroxide preparation should be performed in cases of neonatal pustular disorders to detect bacterial and fungal infections . The goal of this diagnostic approach is to spare a healthy neonate with a benign transient condition an invasive evaluation for sepsis, potentially harmful antibiotic therapy, and prolonged hospitalization, with its own inherent morbidity. J Infect, 1997 Mar, 34(2), 113 - 8 Increasing frequency of vertebral osteomyelitis following Staphylococcus aureus bacteraemia in Denmark 1980-1990; Jensen AG et al.; From 1980 to 1990, 309 cases of haematogenous osteomyelitis were identified in Denmark . Haematogenous osteomyelitis of the vertebral column increased significantly (P < 0.01) from the first to the second half of the period due to an increased number of patients > 50 years of age with community-acquired infection . Vertebral osteomyelitis differed significantly from osteomyelitis of other bones in accordance to age distribution (median 66 vs . 16 years), male/female ratio (75/71 vs . 105/ 58) and patients with diabetes (13% vs . 6%) . We found a higher risk of haematogenous osteomyelitis in patients > 50 years of age and among patients with community-acquired infection . The highest incidence (5%) of vertebral osteomyelitis in Staphylococcus aureus bacteraemia in this age group was found in cases without an identified portal of entry . The highest incidence (34%) of osteomyelitis of other bones was found in community-acquired cases in the age group 1-20 years and without an identified portal of entry . The present study discusses reasons for the continued increase of vertebral osteomyelitis among adults and describes incidence rates and major risk factors for developing haematogenous osteomyelitis among patients with S . aureus bacteraemia . We suggest that the localization of haematogenous S . aureus osteomyelitis is connected with the presence of red bone marrow. Br J Rheumatol, 1997 Mar, 36(3), 328 - 32 Clinical isolates of Staphylococcus aureus have osteolytic surface proteins and a proportion of the population have antibodies that block this activity: is this of prognostic significance? Nair SP, Meghji S, Wilson M, Nugent I, Ross A, Ismael A, Bhudia NK, Harris M, Henderson B. Staphylococcus aureus is directly implicated in the bone destruction associated with infected orthopaedic implants and bacterial arthritis . The Oxford (laboratory) strain of this organism has surface-associated proteins (SAPs) which have potent osteolytic activity . In this study, we have examined the osteolytic activity of SAPs from clinical isolates and also investigated the role of the humoral immune response to such proteins . Nine patients with infected orthopaedic prostheses or infective arthritis, and six volunteers not suffering from overt S . aureus infection, were examined . The sera from 5/9 patients and 4/6 volunteers were able to neutralize the osteolytic activity of the SAPs . The SAPs were extracted from four clinical isolates and were found to have osteolytic activity, but with a wide range of efficacies and potencies . All four patients from whom the clinical isolates were obtained had serum IgG antibodies to the surface proteins from their autologous isolates as determined by ELISA . In conclusion, clinical isolates of S . aureus contain osteolytic SAPs which may be responsible for bone destruction . Apparently disease-free individuals and patients have antibodies able to block this activity . However, since the capacity of patients' sera to neutralize the activity of the SAPs derived from their own S . aureus isolate was not investigated, it is unclear whether these findings are of prognostic value. Eur J Clin Microbiol Infect Dis, 1997 Mar, 16(3), 203 - 9 Central venous catheter-related sepsis in a cohort of 366 hospitalised patients; Tacconelli E et al.; Five hundred two central venous catheters inserted in 366 patients were evaluated prospectively over a one-year period to determine the frequency and risk factors associated with catheter-related sepsis . For study purposes, in cases in which catheter infection was suspected but the initial blood cultures were negative, the catheters were replaced by guidewire technique; otherwise, the catheters were routinely changed after 21 days by guidewire technique . A catheter-related infection was suspected in 190 cases (190/502, 38%) . A diagnosis of catheter-related sepsis was established in 50 patients, which represents 10% of the total number of lines (502) . Over a total of 6428 days of catheter use, the infection rate was 0.8 cases of sepsis per 100 catheter-days . Staphylococcus epidermidis, Staphylococcus aureus, and Candida spp . were the most frequently isolated aetiological agents of sepsis . On univariate analysis, six variables affecting the rate of catheter-related sepsis were identified: neutropenia for more than eight days (p < 0.001); AIDS (p < 0.001); haematological malignancy (p < 0.001); administration of total parenteral nutrition (p = 0.001); duration of site use (p = 0.04); and high APACHE II score (p = 0.04) . The logistic regression analysis revealed that AIDS and haematological malignancies were independent risk factors of catheter-related sepsis . Catheter replacement over a guidewire was no more likely to be associated with sepsis than was percutaneous catheter insertion . In conclusion, although the incidence of established catheter infection is much lower than the incidence of suspected infection, in most cases of suspected infection it is wise to change the catheter with the guidewire technique and wait for culture of the tip, rather than to remove the catheter immediately . Such a policy may help reduce the number of unnecessary catheter removals. Clin Exp Pharmacol Physiol, 1997 Mar-Apr, 24(3-4), 217 - 22 Mechanism of the potentiation of vasoconstriction by neuropeptide Y in arterioles from the submucosa of the guinea-pig small intestine; Neild T et al.; 1 . Neuropeptide Y (NPY; 3-100 nmol/L) caused a concentration-dependent potentiation of constriction in response to noradrenaline or the thromboxane mimetic U46619 in arterioles from the submucosa of the guinea-pig small intestine . 2 . In arterioles permeabilized by exposure to the alpha-toxin of Staphylococcus aureus and maintained in Ca(2+)-buffered medium, NPY potentiated the contractile effects of Ca2+ . The magnitude of the potentiation was the same as in intact arterioles . 3 . Exposure of arterioles to 1 mumol/L nifedipine to inhibit Ca2+ influx or to 20 mumol/L cyclopiazonic acid to abolish Ca2+ uptake into internal stores had no effect on the potentiating action of NPY. Kansenshogaku Zasshi, 1997 Mar, 71(3), 229 - 35 {Coagulase typing of Staphylococcus aureus in the geriatric wards after introduction of preventive measures of hospital infection}; Masaki H et al.; In the early 1980's methicillin-resistant Staphylococcus aureus (MRSA) was reported as a major pathogenic organism of geriatric hospital infection in Japan . At the same time in our geriatric wards, including 190 beds, MRSA infection was prevalent . In the early 1980's in our geriatric wards minocycline was one of the most sensitive antibiotics to MRSA isolated in our wards and used frequently against MRSA pneumonias and bacteremia . In the late 1980's resistant strains of MRSA to minocycline rapidly increased because vancomycin was not allowed to introduced for treatment of MRSA before 1991 in Japan . At the same period the predominant coagulase type changed from type II to type VII . To decrease minocycline-resistant strains to MRSA after 1987, use of minocycline was limited . Moreover since Oct . 1991 to decrease nosocomial infections some active preventive measures against hospital infection, including limited use of 2nd and 3rd cephems, were taken . In this study changing patterns of coagulase type of Staphylococcus aureus were discussed . At least 4 years was needed to find out that the predominant coagulase type changed from type VII to type II again in 1991 . In this study about 22 antimicrobial agents MICs of 313 strains of Staphylococcus aureus isolated between March 1992 and June 1993 were determined and compared with the data of MICs before introduction of preventive measures . The pattern of susceptibility to MINO was in part improved . Thus the some sensitive strains of S . aureus were observed again in our geriatric wards . Interestingly indeed it took approximately 5 years to find out the emergence of sensitive strains to MINO since limitation of use of MINO in 1987. J Med Microbiol, 1997 Mar, 46(3), 222 - 32 Coagulase and protein A polymorphisms do not contribute to persistence of nasal colonisation by Staphylococcus aureus; Van Belkum A et al.; The nasal carriage rate of Staphylococcus aureus was examined in a longitudinal study of 31 healthy Danish volunteers . Each person was classified as persistent (>8 positive cultures from 10 examinations), an intermittent carrier (50-80% positive cultures) or an ocassional carrier (positive cultures on 10-40% of ocassions only) . One hundred and twenty strains from these persons were subjected to phage typing and random amplification of polymorphic DNA (RAPD) analysis . Phage and RAPD typing were in close agreement . RAPD confirmed the spread of a particular S . aureus clone (phage type 95) throughout Denmark . However, no common genotype or phenotype characteristics of S . aureus that could separate persistent from intermittent or incidental colonisers were identified . The immunoglobulin binding protein A and the prothrombin binding coagulase protein are both putative S . aureus virulence or defence factors . Analysis of polymorphisms in the variable repeat regions in the genes for these proteins showed no correlation between the number of repeat units and, consequently, the protein structure with the ability of strains to persist in the human nasal mucosa . The amount of protein A, detectable by its IgG binding activity, appeared not to be correlated to persistence of carriage . Thus protein A and coagulase gene polymorphisms do not seem to play a significant role in the propensity of S . aureus to colonise human nasal epithelium . Furthermore, based on the genetic heterogeneity encountered among the S . aureus strains it is suggested that within the current study population, no single clonal lineage of S . aureus has increased capability to colonise the human nasal epithelium. J Med Microbiol, 1997 Mar, 46(3), 214 - 21 Enterotoxin production by Staphylococcus aureus clones and detection of Brazilian epidemic MRSA clone (III::B:A) among isolates from food handlers; Soares MJ et al.; Staphylococcus aureus is a major bacterial pathogen involved in a wide range of diseases varying from infections to toxaemia . Staphylococcal food-poisoning syndrome is caused by ingestion of bacterial enterotoxins . These toxins are microbial superantigens and may also be virulence factors involved in staphylococcal infection . This study determined the enterotoxin types and pulsed-field gel patterns found among S . aureus isolates obtained from food handlers in community or hospital-located kitchens . Staphylococcal enterotoxin C was the most frequent enterotoxin produced . The data also suggested horizontal spread of ent genes among isolates belonging to the Brazilian epidemic MRSA clone III::B:A . A subclone of MRSA clone III::B:A was isolated from two hospital kitchen workers . This was the first report of this clone from a hospital in Teresina, Piaui State, although the presence of this MRSA clone has already been reported in six other Brazilian cities. J Med Microbiol, 1997 Mar, 46(3), 208 - 13 Role of certain virulence factors in a murine model of Staphylococcus aureus arthritis; Gemmell CG et al.; The susceptibility of male Swiss white mice (MF1) to Staphylococcus aureus-induced arthritis was investigated with wild-type strain allelic replacement mutants . Comparison was made with a known mouse arthritogenic strain . The development and severity of arthritis were dependent both on the numbers of live bacteria injected intravenously and also on the mutant used; the ID50 ranged from (5 X 10(6))-(1 x 10(8)) cfu . The results indicate that expression of the genes associated with virulence, including those for protein A and alpha-haemolysin, play a major role in the pathogenesis of staphylococcal septic arthritis . When either virulence component was carried by the S . aureus variant, a greater degree of inflammation, pannus formation and cartilage destruction was detected histologically . Loss of one or more virulence factors lowered the septic arthritis severity score based on clinical and histological parameters. Scand J Immunol, 1997 Mar, 45(3), 282 - 6 Beneficial effect of glucocorticoids on the course of haematogenously acquired Staphylococcus aureus nephritis; Verba V et al.; The effect of combined antibiotic and corticosteroid treatment on the course of haematogenously acquired Staphylococcus aureus nephritis was studied . Mice were given a single injection of S . aureus producing toxic shock syndrome toxin-1 in a dose capable of inducing a high frequency of inflammatory kidney lesions and divided into three groups according to a treatment regimen . In all untreated animals inflammatory infiltrates were seen in kidney cortex and medulla with high frequencies of glomerular (90%) and tubular damage (50%) as well as fibrotic changes (50%) . The treatment with antibiotics alone reduced significantly only the occurrence of focal inflammatory infiltrates . In contrast, the mice treated with a combination of antibiotics and corticosteroids displayed in 64% of cases normal histological kidney appearance and a significant decrease in occurrence of glomerular (P<0.01) and tubular (P<0.05) lesions . Immunohistochemically, the combined treatment resulted in a more pronounced decrease in numbers of CD4, IL-2R (four to fivefold) and CD8 positive cells in kidney inflammatory lesions compared to antibiotics only treated group . Thus, glucocorticoids in association with antibiotics are shown to improve the outcome of septic murine nephritis, possibly due to suppression of kidney infiltrating T cells. Lab Invest, 1997 Mar, 76(3), 427 - 38 Establishment of three monoclonal antibodies specific for prespermatogonia and intratubular malignant germ cells in humans; Hiraoka N et al.; Intratubular malignant germ cells (ITMGC), as assessed by clinicopathologic or cytogenetic studies, are regarded as a preinvasive lesion of all human testicular germ cell tumors with the exception of yolk sac tumors (in infants) and spermatocytic seminomas . To characterize specific surface molecules of ITMGC, we raised three mouse monoclonal antibodies (mAb) against NCR-G3 (G3), a multipotent, human embryonal carcinoma (EC) cell line, and screened cryostat sections of human testicular tissue containing ITMGC . These three mAb (HB5, IgG1; HF2, IgG1; HE11, IgG1) reacted to the surface of ITMGC, seminomas, and EC in vivo as well as to human EC cell lines in vitro . Expression of HB5 and HF2 antigens was down-regulated during cellular differentiation of G3 cells by retinoic acid or N,N'-hexamethylene-bis-acetamide treatment, whereas that of HE11 antigen was up-regulated with cellular differentiation by retinoic acid . Furthermore, these three mAb reacted to stage-specific prespermatogonia in the human fetus but not in human adults . HB5, HF2, and HE11 antigens were shown to be glycoproteins with molecular weights of approximately 80, 80, and 70 kd, respectively, and could be immunoprecipitated after deglycosylation treatment . Peptide mapping with Staphylococcus aureus V8 protease suggested that the HB5 and HF2 antigens were identical . We concluded that HB5/HF2 and HE11 antigens are oncodevelopmental antigens in testicular germ cell tumors and human spermatogenesis that may play a significant role in tumorigenesis and the development of human germ cells. Chest, 1997 Mar, 111(3), 698 - 705 Acute activation of circulating polymorphonuclear neutrophils following in vivo administration of cocaine . A potential etiology for pulmonary injury; Baldwin GC et al.; Crack cocaine has become a major drug of abuse in the United States and its use is associated with a broad spectrum of pulmonary complications . The present study was conducted to determine whether controlled in vivo administration of cocaine (inhaled or IV) alters the function of circulating inflammatory cells in a manner capable of contributing to acute lung injury . Subjects who regularly smoked crack cocaine were asked to abstain from illicit drug use for at least 8 h, and were then administered one of the following treatments on each of 4 study days: inhaled cocaine base (45 mg), inhaled placebo (4.5 mg cocaine base, a subphysiologic dose), IV cocaine HCl (0.35 to 0.50 mg/kg), or IV placebo (saline solution) . Samples of blood were obtained from a peripheral venous catheter and blood cells were isolated before and 10 to 45 min after treatment . The administration of either cocaine base or cocaine HCl, but not their corresponding placebos, resulted in the activation of circulating polymorphonuclear neutrophils (PMNs) . Exposure to cocaine in vivo enhanced the antibacterial activity of PMNs, as measured by their ability to kill Staphylococcus aureus . Antitumor activity, as measured in an antibody-dependent cell-mediated cytotoxicity assay, also increased following short-term administration of cocaine . Finally, short-term exposure to cocaine enhanced production of interleukin 8, a potent PMN chemoattractant and neutrophil-activating factor associated with both acute and chronic lung injury . These studies demonstrate that short-term in vivo exposure to cocaine activates the effector function and cytokine production of circulating PMNs . Therefore, it is possible that bursts of acute inflammatory activity resulting from crack use could contribute to lung injury. Clin Infect Dis, 1997 Mar, 24(3), 419 - 21 Role of epicardial pacing wire cultures in the diagnosis of poststernotomy mediastinitis; Maroto LC et al.; Mediastinitis after cardiac surgery is difficult to diagnose in many cases . The transitory epicardial pacing wires used after surgery are placed in the mediastinum, so the culture of these wires could be useful for the diagnosis of this disease . To test this hypothesis, we routinely cultured the epicardial pacing wires of 565 patients undergoing extracorporeal circulation . Wires were removed on the 7th to 9th postoperative day under sterile conditions and were cultured with routine techniques used for the culture of venous catheters . Mediastinitis developed in 16 patients, and Staphylococcus aureus was the most common pathogen (81.25%) . We had 103 positive and 462 negative cultures . There were 458 true-negative, 12 true-positive, 91 false-positive and 4 false-negative results . For mediastinitis in general, epicardial pacing wire culture has a sensitivity of 75%, specificity of 83.4%, positive predictive value of 11.6%, and negative predictive value of 99.1% . For Staphylococcus aureus mediastinitis, epicardial pacing wire culture has a sensitivity of 84.6%, specificity of 95.8%, positive predictive value of 32.3%, and negative predictive value of 99.6% . We conclude that a sterile culture of the epicardial pacing wires strongly contradicts a diagnosis of postsurgical mediastinitis. Bioorg Med Chem, 1997 Mar, 5(3), 557 - 67 Studies on 3'-quaternary ammonium cephalosporins--III . Synthesis and antibacterial activity of 3'-(3-aminopyrazolium) cephalosporins; Ohki H et al.; The synthesis and in vitro antibacterial activity of 7 beta-{(Z)-2-(2-aminothiazol-4-yl)-2-methoxyiminoacetamido}cephalos porins bearing N-mono or dialkyl and carbamoyl aminopyrazolium, and five- or six-membered rings fused to the 3-aminopyrazolium methyl groups at the 3-position, are described . Aminopyrazolium methyl cephalosporins (23e, f, i), with fused saturated and unsaturated rings were especially effective against Staphylococcus strains compared to 3-amino-2-methylpyrazolium methyl cephalosporin (1) . Among the cephalosporins prepared in this work, 7 beta-{(Z)-2-(2-aminothiazol-4-yl)-2-methoxyiminoacetamido}-3-(4,5, 6, 7-tetrahydro-1-pyrazolo{1,5-a}pyrimidinio)methyl-3-cephem-4-carbox ylate (23f) showed a good balance of antibacterial activity against both Gram-positive bacteria including Staphylococcus aureus and Gram-negative bacteria including P . aeruginosa . An imidazopyrazolium group at the 3-position in, for example, cephalosporin (23i) was particularly effective for improving antibacterial activity against MRSA. Kaohsiung J Med Sci, 1997 Mar, 13(3), 195 - 9 Septic arthritis of adult hip treated by total hip replacement--a case report; Hsu YP et al.; Septic arthritis is usually seen in children as an acute febrile illness induced by septicemia, local inoculation of a joint caused by trauma or adjacent osteomyelitis . It also occurs in adults particulary those with debilitating disease or sepsis at other sites . It normally happens in knee joints, but rarely in hip joints . A 65-year-old patient suffered from hip pain and febrile episodes intermittently for two months . Diagnostic hip aspiration was performed with 60 ml pus drained . The aspirate grew Staphylococcus aureus . Hip arthrotomy was performed with extensive debridement . Eighteen months later, this patient received total hip replacement and he has remained well for 8 years, with no evidence of infection or of implants loosening. Drugs Aging, 1997 Mar, 10(3), 185 - 98 Methicillin-resistant Staphylococcus aureus in nursing homes . Epidemiology, prevention and management; Bradley SF; Infections caused by Staphylococcus aureus are a significant cause of morbidity and mortality in elderly persons in the community, hospitals and chronic care facilities . Methicillin-resistant S . aureus (MRSA) has become an important cause of severe infection in acutely ill patients in hospitals from diverse geographic areas . Whether MRSA has the same potential to spread and cause infection in nursing homes has only recently been explored . In the facilities studied, asymptomatic MRSA carriage has been common, but patients do not appear to have the same risk of acquiring the organism . The risk of MRSA colonisation appears to be associated with increasing debility, the presence of invasive devices or wounds, and increased overall mortality . Most nursing home residents acquire MRSA during a hospital stay, not in the nursing home . Transmission of MRSA between nursing home residents may be less efficient than that seen among hospitalised patients . Once residents acquire MRSA, they remain persistently colonised for months to years . Many different MRSA strains circulate within nursing homes, probably reflecting the strains found in referring hospitals . Fortunately, although MRSA colonisation is relatively common, rates of MRSA infection and attributable mortality appear to be low . However, the presence of MRSA in a facility might lead to fewer treatment options when infections do occur, with more adverse effects and increased costs . The routine use of surveillance cultures and antibacterials in an attempt to permanently eradicate MRSA from nursing home residents has not been successful, and resistance has quickly emerged . More importantly, nursing homes should utilise infection control practices that disrupt transmission by direct contact, thus preventing the potential spread of MRSA . Simple, inexpensive precautions, which emphasise handwashing and the use of gloves and gowns when soiling by patient body fluids is likely, are generally effective . Knowledge of the patient's MRSA colonisation status is not necessary when these universal barrier precautions are applied to the care of all patients . If an increase in the rate of MRSA infections is documented, more intensive infection control measures should be implemented. Biosci Biotechnol Biochem, 1997 Mar, 61(3), 541 - 4 Gene of LukF-PV-like component of Panton-Valentine leukocidin in Staphylococcus aureus P83 is linked with lukM; Kaneko J et al.; Staphylococcus aureus P83 (ATCC 31890) produces five components, I to V for synergistic toxins, leukocidin and gamma-hemolysin {Sudo et al., Biosci . Biotech . Biochem., 56, 1786-1789 (1995)} . We report here the identification of component II, which is designated LukF-PV(P83) and its gene (lukF-PV(P83)) . The lukF-PV(P83) gene was found to be one base downstream of the stop codon of the lukM gene . The deduced amino acid sequence of LukF-PV(P83) showed 78.4% identity with that of LukF-PV . The lukM and lukF-PV(P83) genes were encoded as one operon like that of Panton-Valentine leukocidin. J Hosp Infect, 1997 Mar, 35(3), 175 - 84 National survey of MRSA: Ireland, 1995; Johnson Z et al.; The objective of this survey was to obtain an indication of the size of the methicillin-resistant Staphylococcus aureus (MRSA) problem in Ireland prior to introducing national MRSA control guidelines . A survey of all microbiology laboratories in Ireland was carried out over two weeks in Spring 1995 . For patients from whom MRSA was isolated during the study period standard demographic and clinical data were requested and period prevalence/1000 discharges was calculated . All 45 microbiology laboratories surveyed responded . MRSA was isolated from 448 patients during the two-week period . The period prevalence of MRSA was 16.5/1000 discharges . Males aged > or = 65 had the highest rate (50/1000 discharges) . Half of all isolates were from patients in surgical or medical wards, but 4% were from community-based sources such as GPs, nursing homes and hospices . Thirty-two percent of MRSA patients were infected rather than colonized . MRSA is clearly a significant problem in Ireland . While it is largely a hospital problem at present, the increasing trend towards day procedures and shorter hospital stay means that infection will increase in the community. Reg Anesth, 1997 Mar-Apr, 22(2), 178 - 84 Bactericidal activity of 0.5% bupivacaine with preservatives on microorganisms in the human skin flora; Sakuragi T et al.; BACKGROUND AND OBJECTIVES: The bactericidal activity of 0.5% bupivacaine with preservatives at body temperature and at room temperature is not known . We studied the bactericidal activity of 0.5% bupivacaine with 0.08% methyl para-oxybenzoate and 0.02% propyl para-aminobenzoate as preservatives and of the preservatives alone at 37 degrees C and at room temperature on two strains of methicillin-resistant Staphylococcus aureus, two strains of methicillin-susceptible S . aureus, and one strain each of Staphylococcus epidermidis and Escherichia coli . METHODS: The pathogen was exposed to 0.5% bupivacaine with preservatives or to the preservatives alone for 1, 3, 6, 12, and 24 hours at 37 degrees C and at room temperature . The inocula from these suspensions were cultured for 48 hours at 37 degrees C after the antimicrobial activity of bupivacaine was inactivated by 1:1,000 dilution with physiological saline . RESULTS: The 1- through 12-hour exposures of four strains of S . aureus to 0.5% bupivacaine with preservatives at room temperature reduced the mean colony count by 24.2%, 49.2%, 71.3%, and 89.6%, respectively, and the exposure at 37 degrees C reduced the count by 74.1%, 95.2%, 99.9%, and 99.8%, respectively . The differences for 1- through 12-hour exposures were significant (P < .001) . The percentage kill in the strains of E . coli and S . epidermidis was significantly higher than that in the strains of S . aureus at all exposure times at room temperature (E . coli, P < .001; S . epidermidis, P < .0001) and at 1- and 3-hour exposures at 37 degrees C (E . coli, P < .001; S . epidermidis, P < .0001) . The bactericidal activity of the preservatives was markedly lower that that of 0.5% bupivacaine with preservatives (P < .0001) . CONCLUSIONS: The bactericidal activity of 0.5% bupivacaine with preservatives is stronger at body temperature than at room temperature; the bactericidal activity may be due, to a large extent, to bupivacaine rather than to the preservatives; and S . aureus is more resistant to the bactericidal activity of bupivacaine than are S . epidermidis and E . coli. Biol Pharm Bull, 1997 Mar, 20(3), 267 - 70 Synthesis of reversed magainin 2 analogs enhanced antibacterial activity; Iwahori A et al.; Magainin 2 is an antimicrobial peptide found in the skin of Xenopus laevis . To find a reversed peptide comparable to the antibacterial activity of magainin 2 analogs, we have synthesized three reversed analogs, the peptide 53D, 87-ISM and A87-ISM, corresponding to the normal peptide D35, MSI-78 and MSI-78A, respectively . We examined their ability to inhibit the growth of Escherichia coli and Staphylococcus aureus . Among the analogs, the A87-ISM, that is, the reverse of MSI-78A enhanced the amphiphilicity and the alpha-helical tendency of magainin 2, showed not only almost the same antibacterial activity against the bacteria as MSI-78A, but also stronger activity than other magainin 2 analogs . In addition, at the MIC (minimum inhibitory concentration) value, A87-ISM shows no hemolysis to human red blood cells, while both MSI-78 and MSI-78A cause strong hemolysis at the MIC value . This result indicates that a novel reversed peptide comparable or superior to normal magainin 2 analogs is available. Zentralbl Veterinarmed B, 1997 Mar, 44(1), 29 - 37 Respiratory burst activity of phagocytic cells isolated from the mammary glands and blood of camels (Camelus bactrianus); Cooray R et al.; The oxidative burst activity of phagocytic cells isolated from camel blood and mammary glands was studied using a chemiluminescence (Cl) assay . The polymorphonuclear leucocytes (PMNL) isolated from camel blood mounted a luminol-dependent Cl response upon stimulation with opsonized zymosan or opsonized Staphylococcus aureus . These responses showed an overall similarity to those described in other mammalian species . The leucocytes isolated from the mammary glands mounted Cl responses similar to those observed with blood PMNL but to a lower magnitude . Like the Cl responses of blood cells, the Cl responses induced by mammary gland leucocytes were associated with degranulation and the release of lysosomal enzymes such as myeloperoxidase (MPO). Am J Sports Med, 1997 Mar-Apr, 25(2), 261 - 7 Septic arthritis after arthroscopic anterior cruciate ligament reconstruction . Diagnosis and management; Williams RJ 3rd et al.; We performed a retrospective study of knee joint infections after arthroscopic anterior cruciate ligament reconstruction at our institution . Two thousand five hundred anterior cruciate ligament reconstructions were performed between 1988 and 1993 . Seven (0.3%) patients experienced postoperative deep infections of the knee . All anterior cruciate ligament reconstructions were performed using arthroscopically assisted techniques . Six (86%) of these patients had concomitant open procedures performed, including meniscal repair, posterolateral corner reconstruction, and medial collateral ligament reconstruction . Four patients had acute (< 2 weeks), two patients had subacute (2 weeks to 2 months), and one patient had late (> 2 months) infections . All patients had positive cultures from knee joint aspirates with the organisms Staphylococcus aureus, Staphylococcus epidermidis, Peptostreptococcus, or a combination thereof . All patients underwent immediate arthroscopic irrigation and debridement . All infections were intraarticular; six patients also had extraarticular sites of infection . Four patients underwent repeat irrigation and debridement at approximately 1 week . The anterior cruciate ligament graft was removed from four patients . All patients were treated with intravenous antibiotics for 4 to 6 weeks, protected weightbearing, and physical therapy . At a mean followup of 29 months, mean knee extension was 0 degree, and mean knee flexion was 122 degrees (range, 70 degrees to 135 degrees) . Six (86%) patients had minimal to no pain in their operative knee, and they were satisfied with their functional results. Arch Otolaryngol Head Neck Surg, 1997 Mar, 123(3), 328 - 36 Clinical and histologic response of subcutaneous expanded polytetrafluoroethylene (Gore-Tex) and porous high-density polyethylene (Medpor) implants to acute and early infection; Sclafani AP et al.; OBJECTIVE: To examine the responses of subcutaneously implanted expanded polytetrafluoroethylene (e-PTFE, Gore-Tex) and porous high-density polyethylene (PHDPE, Medpor) to experimentally induced infection . DESIGN: Sprague-Dawley rats were implanted subcutaneously with either e-PTFE or PHDPE implants . Inocula of Staphylococcus aureus were injected directly over the implants and the wounds were observed for clinical signs of infection . After the animals were killed, the implants were harvested and underwent Histologic examination . SUBJECTS: Twenty-eight adult male Sprague-Dawley rats weighing 200 to 250 g . INTERVENTION: A 8-mm diameter, 1-mm-thick implant of either e-PTFE or PHDPE was placed in a subcutaneous pocket over each animal's dorsum . Either at the time of implantation or 14 days afterward, an inoculum of 10(9) colony-forming units of S aureus was injected transcutaneously directly over each implant . The animals were observed for 7 days before being killed . The implants were harvested and examined by both conventional light and scanning electron microscopy, and the degree of capsule reaction, infection, inflammation, and implant degradation was evaluated . RESULTS: Implants inoculated at the time of implantation were more likely to become clinically infected . Results for e-PTFE and PHDPE implants were similar in this group (5 of 5 e-PTFE and 5 of 5 PHDPE implants infected) . The PHDPE implants inoculated 14 days after implantation were less likely to become infected (1 of 4 infected) than e-PTFE implants (3 of 4 infected), and were statistically less likely to become infected than PHDPE implants inoculated immediately after implantation (25% vs 100%; P < .02) . Histologically, this resistance to infection correlated with increasing fibrovascular ingrowth into the PHDPE implants . The infected PHDPE implant had little to no ingrowth compared with PHDPE control implants . The uninfected e-PTFE implant had evidence of early fibrovascular ingrowth into the peripheral pores of the implant . CONCLUSIONS: Because of differences in pore size, PHDPE promotes faster fibrovascular ingrowth . The presence of vascularized host tissue in and around the implant lends stability and resistance to experimentally induced infection . Conservative management of clinical implant infections should be considered if bacterial seeding occurs after substantial fibrovascular ingrowth is present . Future alloplast designs should include pore sizes that will encourage invasion of the implant by host tissue. Scand J Plast Reconstr Surg Hand Surg, 1997 Mar, 31(1), 77 - 81 Toxic shock syndrome after burn injuries in children; Blomqvist L; Toxic shock syndrome is a life-threatening exotoxin mediated disease caused by Staphylococcus aureus, which was originally described as affecting menstruating women, but has lately been reported after surgical procedures and burns . The high mortality emphasises the importance of early diagnosis . In most cases there is a prodromal period with fever (> 38.9 degrees C), myalgia, headache, and vomiting before the onset of hypotension and multiorgan failure . We present two cases in children with minor burns, and review current recommendations for treatment. Ann Pharmacother, 1997 Mar, 31(3), 315 - 8 Vancomycin-induced thrombocytopenia: a challenge and rechallenge; Howard CE et al.; OBJECTIVE: To report a case of thrombocytopenia apparently associated with vancomycin use . CASE SUMMARY: A 58-year-old white man was admitted to the hospital with chronic osteomyelitis of the foot due to methicillin-resistant Staphylococcus aureus that later spread hematogenously to the cervical vertebrae . During the first course of therapy with vancomycin, his platelet count decreased from 397 x 10(3)/mm3 to 22 x 10(3)/mm3 . After discontinuation of the drug, it increased to 310 x 10(3)/mm3 . During the second course of vancomycin, the platelet count decreased to 77 x 10(3)/mm3, and increased to 404 x 10(3)/mm3 after discontinuation of the drug . DISCUSSION: Vancomycin has been reported as a rare cause of thrombocytopenia . Thrombocytopenia can occur as an adverse drug reaction by the following three mechanisms: direct toxic effect, drug absorption (hapten) formation, and an "innocent bystander" immune response . CONCLUSIONS: We suspect that the thrombocytopenia in this patient, which involved an increased number of megakaryocytes in the bone marrow, was due to vancomycin. FEMS Microbiol Lett, 1997 Mar 1, 148(1), 91 - 6 A dyadic plasmid that shows MLS and PMS resistance in Staphylococcus aureus; Matsuoka M et al.; Out of a collection of 56 Staphylococcus aureus clinical strains from 1971 to 1990 in Japan, we found one 1971 isolate, strain MS8968, harboring plasmid pMS97 . A transductant strain, MS15009(pMS97), showed inducible resistance to a group of drugs, the so-called MLS antibiotics in the presence of a low concentration of erythromycin (EM) . However, in the case of oleandomycin (OL), the strain showed resistance to another group of antibiotics: 14-membered macrolides (EM and OL), a 16-membered macrolide (mycinamicin I), and type B streptogramin, the so-called PMS antibiotics . Moreover, plasmid pMS97 contained an erm gene with universal primers specific for erm A, AM, B, BC, C, C', and G and an msrA gene with primers specific for msrA . The first finding suggests that two genes encoding functionally different mechanisms for MLS and PMS resistance, erm and msrA, are present together within plasmid pMS97 originating from S . aureus. Biochem J, 1997 Mar 1, 322 ( Pt 2), 353 - 63 Induction of cytosolic phospholipase A2 activity by phosphatidic acid and diglycerides in permeabilized human neutrophils: interrelationship between phospholipases D and A2; Bauldry SA et al.; Relationships between phospholipases are poorly understood, but phosphatidic acid (PA) and diglycerides (DGs), produced by phospholipase D (PLD) and phosphatidate phosphohydrolase actions, might function as second messengers coupling cell stimulation to cellular responses . This study investigates the role of PLD-mediated PA and DG formation in inducing phospholipase A2 (PLA2) activity in intact human neutrophils (PMNs) and in PMNs permeabilized with Staphylococcus aureus alpha-toxin . PMNs were labelled with {3H}arachidonic acid (AA) to assess AA release and metabolism and diacylglycerol formation, or with {3H}1-O-hexadecyl-2-lyso-glycerophosphatidylcholine for the determination of platelet-activating factor (PAF), PA and alkylacylglycerol production . In intact PMNs primed with tumour necrosis factor alpha before stimulation with N-formyl-Met-Leu-Phe, AA release and metabolism and PAF formation increased in parallel with enhanced PA and DG formation, and inhibition of PA and DG production led to a decrease in both AA release and PAF accumulation . In alpha-toxin-permeabilized PMNs, AA release and PAF production result from the specific activation of cytosolic PLA2 (cPLA2) . In this system, PA and DG formation were always present when cPLA2 activation occurred; blocking PA and DG production inhibited AA release and PAF accumulation . Adding either PA or DG back to permeabilized cells (with endogenous PA and DG formation blocked) led to a partial restoration of AA release and PAF formation; a combination of PA and DGs reconstituted full cPLA2 activity . These results strongly suggest that products of PLD participate in activating cPLA2 in PMNs. Clin Orthop, 1997 Mar, (336), 278 - 85 Delayed local treatment of rabbit tibial fractures with biodegradable cefazolin microspheres; Jacob E et al.; The prevention of infection is a primary objective in the treatment of open fractures . The objective of this study was to compare the efficacy of biodegradable, poly (DL-lactide-co-glycolide) cefazolin microspheres and free cefazolin powder in Staphylococcus aureus contaminated rabbit tibial fractures when treatment was delayed for 2 hours . Fractures were produced in the tibia of rabbits, inoculated with Staphylococcus aureus, and 2 hours later treated by either direct local application of cefazolin microspheres or an equivalent dose of free cefazolin powder . Control animals did not receive antibiotic therapy . The fractures then were stabilized with a bone plate, and the animals were observed for 8 weeks . Local antibiotic therapy with biodegradable cefazolin microspheres prevented the establishment of infection in all animals, and cultures of the tibiae were sterile in all cases . In contrast, clinical evidence of infection developed in 50% of the rabbits that had been treated with free cefazolin powder and 71% of the control animals . Staphylococcus aureus was recovered from the tibiae of 75% and 100% of these animals, respectively . The results of this study suggest that local antibiotic therapy with biodegradable, controlled release cefazolin microspheres may be useful for the management of open fractures in humans, even when treatment is delayed for several hours after bacterial contamination. Blood, 1997 Mar 1, 89(5), 1612 - 20 Inhibition of the defense system stimulating interleukin-12 interferon-gamma pathway during critical Illness; Ertel W et al.; Interleukin-12 (IL-12) and interferon-gamma (IFN-gamma) exert protective effects during experimental endotoxemia through upregulation of cellular immunity and phagocytic functions . They are part of a positive regulatory feedback loop that enhances the production of the other . Because critically ill patients show a marked suppression of T-cell and macrophage functions with a high susceptibility to infection, potential defects in the immunity/inflammation upregulating IL-12 IFN-gamma pathway were studied . As an ex vivo model of endotoxemia, lipopolysaccharide (LPS) stimulated whole blood from 25 critically ill patients and 12 healthy individuals was incubated with either recombinant human (rh) IL-12 or rhIFN-gamma, respectively . IFN-gamma dose-dependently (P < .05) increased the release of IL-12 p40 and p70 into LPS-stimulated whole blood from healthy humans without effect in whole blood from critically ill patients . RhIL-12 p70 enhanced (P < .05) the secretion of IFN-gamma in controls, while it was ineffective in LPS-stimulated whole blood from critically ill patients . The observed inhibition of the IL-12 IFN-gamma pathway is not specific to LPS, since Staphylococcus aureus Cowan strain I (SAC)-stimulated whole blood from critically ill patients showed similar suppression . The secretion of IL-12 and IFN-gamma was less reduced in critically ill patients when using isolated cultures of adherent cells or lymphocytes . Although preculture of whole blood from healthy humans with IL-10, but not with IL-4, mimicked suppression of the IL-12 IFN-gamma pathway similar to that observed during critical illness, the release of antiinflammatory reacting cytokines (IL-4, IL-10, transforming growth factor {TGF}-beta 1) was decreased into LPS-stimulated whole blood from critically ill patients . These results indicate at least two mechanisms responsible for dramatic disturbances of the IL-12 IFN-gamma pathway during critical illness: (1) deactivation of IL-12 and IFN-gamma producing leukocytes in vivo early after the primary insult, and (2) presence of serum suppressive factors different from IL-4, IL-10, or TGF-beta 1 . Because IL-12 and IFN-gamma upregulate essential immune functions, the marked inhibition of IL-12 and IFN-gamma release may be pivotal for high susceptibility of critically ill patients to infection. Protein Expr Purif, 1997 Mar, 9(2), 228 - 32 Exploiting the unique biophysical properties of bacteriocins to purify Bac 1829 from Staphylococcus aureus KSI1829; Crupper SS et al.; Bac1829 from Staphylococcus aureus KSI1829 is a newly identified peptide bacteriocin that inhibits a broad spectrum of bacteria . By taking advantage of its cationic and hydrophobic nature, a purification scheme was developed utilizing preparative isoelectric focusing and hydrophobic interaction chromatography . Due to a high pI value of approximately 9-10, 71% of the total Bac1829 activity was concentrated in two fractions by preparative isoelectric focusing . Final purification by high performance liquid chromatography on a propyl hydrophobic interaction column resulted in a 136-fold purification with an increase in specific activity from 181 to 24,623 antimicrobial units (AU)/mg protein . A total of 14,848 AU of Bac 1829 were purified using this revised procedure, compared to 8702 AU as described previously . Mass spectrographic analysis of the purified sample yielded a single peak of 6418 +/- 2 daltons . Since many bacteriocins possess similar biophysical attributes, the purification scheme presented in this communication may be applicable to those which have proven difficult to purify or have not been purified. Antimicrob Agents Chemother, 1997 Mar, 41(3), 530 - 4 Induction of ermSV by 16-membered-ring macrolide antibiotics; Kamimiya S et al.; The erm family of 23S rRNA adenine-N6-methyltransferases confers resistance to all macrolide-lincosamide-streptograminB (MLS) antibiotics, but not all MLS antibiotics induce synthesis of Erm methyltransferase with equal efficiency in a given organism . The induction efficiency of a test panel of MLS antibiotics was studied by using two translational attenuator-lac reporter gene fusion constructs, one based on ermSV from Streptomyces viridochromogenes NRRL 2860 and the other based on ermC from Staphylococcus aureus RN2442 . Four types of responses which were correlated with the macrolide ring size were seen, as follows: group 1, both ermSV and ermC were induced by the 14-membered-ring macrolides erythromycin, lankamycin, and matromycin, as well as by the lincosamide celesticetin; group 2, neither ermSV nor ermC was induced by the 12-membered-ring macrolide methymycin or by the lincosamide lincomycin or the streptogramin type B antibiotic ostreogrycin B; group 3, ermSV was selectively induced over ermC by the 16-membered-ring macrolides carbomycin, chalcomycin, cirramycin, kitasamycin, maridomycin, and tylosin; and group 4, ermC was selectively induced over ermSV by the 14-membered-ring macrolide megalomicin . These data suggest that the leader peptide determines the specificity of induction by different classes of MLS antibiotics and that for a given attenuator, a major factor which determines whether a given macrolide induces resistance is its size. Ann Emerg Med, 1997 Mar, 29(3), 404 - 8 Incision and drainage of cutaneous abscesses is not associated with bacteremia in afebrile adults; Bobrow BJ et al.; STUDY OBJECTIVE: To determine the prevalence of bacteremia associated with incision and drainage (I&D) of cutaneous abscesses in afebrile adult emergency department patients . Such information has implications for the ED management of immunocompromised patients, patients with history of endocarditis, and patients with prosthetic appliances such as heart valves and artificial joints . METHODS: We conducted a prospective clinical study in the adult ED of an urban tertiary care teaching hospital . Our subjects were afebrile patients aged 18 to 65 years with localized, nondraining, purulent cutaneous abscesses requiring outpatient surgical management . Before I&D, blood for aerobic and anaerobic blood culture was drawn under sterile conditions . The wound was opened and samples for aerobic wound culture were obtained . Two and 10 minutes after I&D, blood was again drawn, from separate venipunctures . All patients were discharged home with ED follow-up scheduled 48 hours later . RESULTS: From the 50 patients who completed the study, 150 blood samples (50 before and 100 after I&D) and 50 wound samples were obtained . No blood culture was positive, but 30 wound cultures (64%) were positive; the most commonly isolated organism was Staphylococcus aureus . CONCLUSION: I&D of localized cutaneous abscesses in afebrile adults is unlikely to result in transient bacteremia . Larger studies are needed to determine whether routine antibiotic prophylaxis is necessary for afebrile patients undergoing I&D. Phytochemistry, 1997 Mar, 44(6), 985 - 9 Isolation of six low molecular weight heat shock proteins and partial characterization of heat shock protein 29 from mung bean hypocotyl; Wu DH et al.; Heat shock protein (HSP29) together with five other low-M(r) HSPs have been isolated from mung bean hypocotyls by preparative continuous elution SDS-PAGE . Autoradiography and immunochemical analysis of 2D electrophoretograms of the radiolabelled HSP29 revealed that it consists of seven isotypes, two of which are constitutive while the other five are heat-inducible . The pI values of the seven isotypes range from 4.6 to 6.6 . A monoclonal antibody raised against the HSP29 isolate reacted with six of the seven isotypes . When HSP29 was subjected to partial proteolysis by V8 Staphylococcus aureus protease (EC 3.4.21.19), two fragments of 12 and 17 kDa were identified, neither of which was recognized by the antibody. J Bacteriol, 1997 Mar, 179(5), 1614 - 21 Molecular characterization and transcriptional analysis of type 8 capsule genes in Staphylococcus aureus; Sau S et al.; A 20.5-kb contiguous DNA fragment from Staphylococcus aureus Becker affecting type 8 capsule (CP8) biosynthesis was previously cloned . Sequencing analysis indicated that 16 open reading frames (ORFs) encoded within this fragment might be involved in CP8 synthesis . Using various plasmids containing DNA inserts derived from the 20.5-kb region, we showed by complementation of chemical mutants that 8 of the 16 ORFs were required for CP8 synthesis . To determine the involvement of the remaining eight ORFs, nonpolar gene-specific chromosomal mutations located in each of these ORFs were constructed . We found that three additional ORFs were also involved in the CP8 synthesis . Thus, 11 of the 16 ORFs were shown to affect CP8 synthesis . Complementation analyses of these 11 type 8 capsule (cap8) genes affecting CP8 production showed several promoters within the cap8 gene cluster . However, by Northern hybridization using either the entire cap8 gene cluster or the internal fragments of individual ORFs as probes, one 17-kb cap8-specific transcript was detected . Using xylE as the reporter gene, we found that the promoter at the beginning of the cap8 operon was much stronger than any of the internal promoters . These results suggest that the cap8 genes are transcribed mainly as a single large transcript . In addition, Southern hybridization analyses showed that cap8H, cap8I, cap8J, and cap8K, located in the central region of the cap8 gene cluster, were CP8 specific. Mol Cells, 1997 Feb 28, 7(1), 28 - 33 Regulation of toxic shock syndrome toxin-1 gene in Staphylococcus aureus; Woo JH et al.; Staphylococcus aureus produces various proteins in response to discrete signals from the external environment like many other pathogenic microorganisms . Certain staphylococcal exoproteins including toxic shock syndrome toxin-1 (TSST-1) are secreted according to the stimuli from the environment, and the quantity synthesized is influenced by a number of different parameters . Using a transposon Tn551-mediated mutagenesis, a mutant (RN 6390) defective in TSST-1 from synthesis was constructed . TSST-1 from wild strain and mutant stain were purified and quantitated from culture supernatants of Staphylococcus aureus . The mutant strain RN 6390 produced only 2% of TSST-1 compared with that produced by the wild strain RN4282 . Southern blot hybridization with a tst (TSST-1 gene) probe indicated that the inactivated chromosomal locus is distinct from the tst . These results suggest that transposition by Tn551 inactivated a chromosomal locus whose activity was essential for the expression of the TSST-1 gene. Biochim Biophys Acta, 1997 Feb 18, 1344(3), 230 - 40 Interfacial regulation of bacterial sphingomyelinase activity; Jungner M et al.; The objective of this study was to define how the quality of the buffer/membrane interface influences the activity of bacterial sphingomyelinase acting at the interface . The enzyme reaction was carried out in a zero-order trough using a surface barostat . This approach allowed for proper control of the physico-chemical properties of the substrate molecules . Since the molecular area of ceramide is smaller than that of sphingomyelin, the hydrolysis reaction could be followed 'on-line' from the monolayer area decrease at constant surface pressure . The hydrolysis reaction could be divided into two separate phases, the first being the lag-phase (time between enzyme addition and commencement of the monolayer area change), and the second phase being the actual hydrolysis reaction (from which a maximal degradation rate could be determined) . The activity of sphingomyelinase (Staphylococcus aureus) toward bovine brain sphingomyelin (bb-SM) was markedly enhanced by Mg2+ (maximal activation at 5 mM) . Mg2+ also influenced the lag-phase of the reaction (the lag-time increased markedly when the Mg2+ concentration decreased below 1 mM) . Saturated sphingomyelins (bb-SM and N-palmitoyl sphingomyelin {N-P-SM}) were more slowly degraded than the mono-unsaturated N-oleoyl sphingomyelin (N-O-SM) . Both bb-SM and N-P-SM monolayers underwent a phase-transition at room temperature, whereas the N-O-SM monolayer did not . The phase-transition (liquid-expanded to liquid-condensed) was observed to greatly increase the lag-time of the hydrolysis reaction . The activity of sphingomyelinase was also sensitive to the lateral surface pressure of the monolayer membrane . Maximal degradation rate was achieved at 20 mN/m (with bb-SM, 30 degrees C); above this pressure the lag-time of the reaction increased sharply . The inclusion of 4 mol% of cholesterol into a {3H}sphingomyelin monolayer markedly increased the extent of {3H}sphingomyelin degradation, and shortened the lag-time of the reaction . The inclusion of 10 mol% of zwitterionic or negatively charged phospholipids to the {3H}sphingomyelin monolayer did not affect the sphingomyelinase reaction significantly . In conclusion, this study has demonstrated that the physico-chemical properties of the substrate molecules have a dominating influence on the activity of a bacterial sphingomyelinase acting at the buffer/membrane interface. Orv Hetil, 1997 Feb 16, 138(7), 397 - 401 {Chronic granulomatous disease (CGD): dysfunction of the neutrophil granulocyte NADPH-oxidase enzyme system}; Nemet K et al.; Dysfunction of NADPH oxidase results in chronic granulomatous disease (CGD), a syndrome characterized by severe bacterial and fungal infections . Phagocytes of the patients are unable to kill ingested microorganisms which leads to the formation of granulomas and abscesses . Predominant pathogens are the catalase-positive bacteriae (Staphylococcus aureus) and some fungi (Aspergillus species) . Infections of these patients should be treated by antimicrobial agents, which penetrate cells and kill pathogens inside . The aim of this study was to give a short description of the structure and function of the NADPH oxidase enzyme and to summarize the results obtained during the diagnostic of 10 patients with chronic granulomatous disease . Characterization of the disease was confirmed by mutation analyses. J Immunol, 1997 Feb 15, 158(4), 1670 - 80 Anti-human kappa opioid receptor antibodies: characterization of site-directed neutralizing antibodies specific for a peptide kappa R(33-52) derived from the predicted amino terminal region of the human kappa receptor; Buchner RR et al.; Site-directed polyclonal Abs specific for a synthetic peptide with sequence homology to the predicted N-terminal sequence of the human kappa opioid receptor {anti-kappa R-(33-52)} are capable of binding to normal human cells and cell lines expressing mRNA specific for the human kappa receptor . Flow cytometric analysis of 1) a neuronal cell line (NT2), 2) blood-derived CD14+ monocytes, 3) monocyte-like cell lines (U937 and THP 1), 4) blood-derived CD3+ T cells and a T cell line, and 5) human B cell lines bound anti-kappa R-(33-52) in a specific manner . Anti-kappa R-(33-52) was also found to specifically neutralize the immunosuppressive activities associated with the kappa R-selective agonist U50,488H . This antiserum was found to block U50,488H-mediated inhibition of 1) Staphylococcus aureus Cowen strain I-induced B and T lymphocyte proliferation, 2) PHA-induced T lymphocyte proliferation, and 3) S . aureus Cowen strain I-induced IgG production . However, this antiserum failed to neutralize mu R-selective agonist (Tyr-D-Ala-Gly-NMe-Phe-Gly-ol)-mediated suppression of IgG synthesis . Finally, the kappa R-selective antagonist nor-binaltorphimine hydrochloride inhibits the binding of anti-kappa R-(33-52) to the U937 cell line . These results suggest that anti-kappa R-(33-52) specifically interacts with the human kappa R molecule . Studies conducted with anti-kappa R-(33-52) indicated that this antiserum effectively blocked U50,488H-mediated immunosuppression, but by itself did not enhance or suppress lymphocyte activation . These data suggest that anti-kappa R-(33-52) 1) does not interact with the effector binding site of the receptor, but sterically interferes with U50,488H binding to the receptor; and/or 2) the antiserum interacts with a secondary binding site that is important for ligand binding, but may not be involved in signal transduction. J Mol Biol, 1997 Feb 14, 266(1), 23 - 30 A single amino acid substitution in Staphylococcus aureus dihydrofolate reductase determines trimethoprim resistance; Dale GE et al.; A single amino acid substitution, Phe98 to Tyr98, in dihydrofolate reductase (DHFR) is the molecular origin of trimethoprim (TMP) resistance in Staphylococcus aureus . This active site amino acid substitution was found in all S . aureus TMP-resistant clinical isolates tested . In order to explore the structural role of Tyr98 in TMP-resistance the ternary complexes of the chromosomal S . aureus DHFR (SaDHFR) with methotrexate (MTX) and TMP in the presence of nicotinamide adenine dinucleotide phosphate (NADPH) as well as that of mutant Phe98Tyr DHFR SaDHFR(F98Y) ternary folate-NADPH complex have been determined by X-ray crystallography . Critical evidence concerning the resistance mechanism has also been provided by NMR spectral analyses of 15N-labelled TMP in the ternary complexes of both wild-type and mutant enzyme . These studies show that the mutation results in loss of a hydrogen bond between the 4-amino group of TMP and the carbonyl oxygen of Leu5 . This mechanism of resistance is predominant in both transferable plasmid-encoded and non-transferable chromosomally encoded resistance . Knowledge of the resistance mechanism at a molecular level could help in the design of antibacterials active against multi-resistant Staphylococcus aureus (MRSA), one of todays most serious problems in clinical infectology. Br J Nurs, 1997 Feb 13-26, 6(3), 134 - 6, 138, 140-2 The nursing management of MRSA on a spinal injuries unit; Tyler C; The aim of this article is to encourage nurses to question their actions when caring for patients with methicillin-resistant Staphylococcus aureus (MRSA) . Some of the main effects of isolation are discussed with reference to specific problems encountered by spinal cord-injured patients in isolation . The advantages and potential problems of a policy for the management of MRSA in a spinal injuries unit are outlined . It concludes that it is not always necessary to isolate all patients who are colonized/Infected with MRSA; provided that basic Infection control measures are followed carefully, and staff, patients, and visitors are educated on the risks of MRSA, it is safe to nurse some of these patients on an open ward. Biochim Biophys Acta, 1997 Feb 7, 135