Mol Microbiol, 2001 Aug, 41(3), 665 - 73 Identification of a cell wall channel of Streptomyces griseus: the channel contains a binding site for streptomycin; Kim BH et al.; Cells of the Gram-positive actinomycete Streptomyces griseus were disrupted and the cell envelope was subjected to sucrose step-gradient centrifugation . The different fractions were analysed for NADH-oxidase activity and the formation of ion-permeable channels in lipid bilayers . Highest channel-forming activity and highest NADH-oxidase activity were found in different fractions . The cell wall fraction contained an ion-permeable channel with a single-channel conductance of 850 pS in 1 M KCl . The channel-forming protein, with an apparent molecular mass of 28 kDa, was purified to homogeneity using fast protein liquid chromatography after the extraction of whole cells with detergent . Single-channel experiments suggest that the cell wall channel is wide and water-filled . Titration experiments with streptomycin produced by S . griseus suggested that the cell wall channel binds this antibiotic with a half saturation constant of about 6 mM in 1 M KCl . The binding of streptomycin was found to be ionic strength dependent and the half saturation constant decreased to 60 microM at 0.1 M KCl . The results indicate that the 28 kDa protein represents the hydrophilic pathway through the cell wall of the Gram-positive bacterium S . griseus. Shock, 2001 Sep, 16(3), 178 - 82 Peptidoglycan primes for LPS-induced release of proinflammatory cytokines in whole human blood; Wang JE et al.; The pathophysiological mechanisms involved in mixed bacterial infections caused by gram-positive and gram-negative bacteria are largely unknown . The present study examines the potential interaction between lipopolysaccharide (LPS) and peptidoglycan (PepG) in the induction of the sepsis-associated cytokines tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and IL-10 in whole human blood . Plasma values of these cytokines were measured by enzyme immunoassays and a TNF bioassay . Co-administration of PepG (10 microg/mL) or muramyl dipeptide (MDP, 1 microg/mL) with LPS (10 ng/mL) caused significantly elevated values of TNF-alpha and IL-6 in the blood that could not be obtained by the sum of the values obtained by each stimulant alone, or by 3-fold higher doses of either bacterial component alone . This phenomenon was observed 1 h after stimulation, throughout the experimental period (24 h), and with different doses of LPS and PepG . In contrast, the release of IL-10 was not influenced by the co-administration of PepG or MDP with LPS . The TNF-alpha release induced by co-administration of LPS and PepG was abrogated after pretreatment with a monoclonal antibody against CD14 (18D11) . Addition of PepG or MDP to whole blood caused a 2-fold increase in the surface expression of CD14 on monocytes, as measured by flow cytometry . In contrast, LPS caused decreased expression of this receptor . Our data suggest that PepG and MDP primes human whole blood leukocytes for LPS-induced release of proinflammatory cytokines . We speculate that synergy between PepG and LPS may contribute to the pathogenesis in sepsis caused by mixed bacterial infections. Clin Diagn Lab Immunol, 2001 Sep, 8(5), 972 - 9 Lipoteichoic acid inhibits interleukin-2 (IL-2) function by direct binding to IL-2; Plitnick LM et al.; Lipoteichoic acid (LTA) is associated with the cell envelope of most gram-positive bacteria . Although previously thought to act mainly as a virulence factor by virtue of its adhesive nature, evidence is now provided that LTA can also suppress the function of interleukin-2 (IL-2), an autocrine growth factor for T cells . LTA from four separate bacterial strains lowered the levels of detectable IL-2 during a peripheral blood mononuclear cell response to the antigen tetanus toxoid (TT) . T-cell proliferation in response to TT was similarly inhibited by LTA . In contrast, levels of detectable gamma interferon increased . In addition, LTA inhibited IL-2 detection by enzyme-linked immunosorbent assay (ELISA) and blocked the proliferative response of an IL-2-dependent T-cell line to soluble IL-2 . Further studies using ELISA demonstrated that LTA blocks IL-2 detection and function by binding directly to IL-2 . Flow cytometric analysis revealed that IL-2 binding to T cells is inhibited in the presence of purified LTA but not LTA plus anti-LTA monoclonal antibody . In summary, these studies demonstrate a novel effect of LTA on the immune response through direct binding to IL-2 and inhibition of IL-2 function . Importantly, gram-positive organisms from which LTA is obtained not only play an important role in the pathology of diseases such as bacterial endocarditis, septic shock, acute respiratory distress syndrome, and multiple organ failure but also comprise a significant portion of commensal populations within the human host . Inhibition of IL-2 function by LTA may represent yet another mechanism by which gram-positive bacteria dampen the host immune response and facilitate survival . Thus, LTA provides a potential target for therapeutic intervention when gram-positive organisms are involved. J Endotoxin Res, 2000, 6(5), 401 - 5 Role of MD-2 in TLR2- and TLR4-mediated recognition of Gram-negative and Gram-positive bacteria and activation of chemokine genes; Dziarski R et al.; MD-2 is associated with TLR4 on the cell surface and enables TLR4 to respond to LPS . TLR2 without MD-2 does not respond to pure protein-free endotoxic LPS, ReLPS, and lipid A . MD-2 enables TLR2 to respond to non-activating LPS, ReLPS, and lipid A, and enhances TLR2-mediated responses to Gram-negative and Gram-positive bacteria, protein-containing LPS, peptidoglycan, and lipoteichoic acid . MD-2 enables TLR4 to respond to a wide variety of endotoxic LPS partial structures, Gram-negative bacteria, and Gram-positive lipoteichoic acid, but not to Gram-positive bacteria, peptidoglycan, and lipopeptide . MD-2 physically associates with both TLR4 and TLR2, but the association with TLR2 is weaker than with TLR4 . Also, MD-2 and TLR2 and TLR4 enhance each other's expression . The highest induced genes in human monocytes stimulated with Gram-positive and Gram-negative bacterial cell wall components are chemokine genes, and IL-8 is the highest induced chemokine . Both Gram-positive and Gram-negative bacteria activate TLR2-->MyD88-->IRAK-->TRAF-->NIK-->IKK-->NF-->kappaB signal transduction pathway that induces transcription of the IL-8 gene . Therefore, TLR2 is a functional receptor for both Gram-positive and Gram-negative bacteria and it induces activation of IL-8. J Endotoxin Res, 2000, 6(5), 383 - 7 The role of Toll-like receptors and MyD88 in innate immune responses; Akira S et al.; Toll-like receptors (TLRs) are phylogenetically conserved receptors that recognize pathogen associated molecular patterns (PAMPS) . We previously generated mice lacking TLR2 and TLR4 and showed the differential role of TLR2 and TLR4 in microbial recognition . TLR4 functions as the transmembrane component of the lipopolysaccharide (LPS) receptor, while TLR2 recognizes peptidoglycan from Gram-positive bacteria and lipoprotein . We also generated mice lacking MyD88, an adaptor involved in IL-1R/TLR signalings . The responses to a variety of bacterial components were completely abrogated in MyD88-deficient cells . However, unlike the signaling mediated by other bacterial components such as lipoprotein and bacterial DNA, activation of NF-kappaB and MAP kinases was induced in response to LPS even in the absence of MyD88, which indicates the existence of a MyD88-independent pathway . We have recently found that the MyD88-independent pathway is involved in LPS-induced maturation of dendritic cells (DCs). Pediatr Res, 2001 Sep, 50(3), 315 - 21 Toll-like receptors as sensors of pathogens; Hallman M et al.; Initial recognition of microbes, as they enter the body, is based on germ line-encoded pattern recognition receptors that selectively bind to essential components of pathogens . This allows the body to respond immediately to the microbial invasion before the development of active immunity . The signal-transducing receptors that trigger the acute inflammatory cascade have been elusive until very recently . On the basis of their genetic similarity to the Toll signaling pathway in Drosophila, mammalian Toll-like receptors (TLRs) have been identified . By now, nine transmembrane proteins in the TLR family have been described . Mammalian TLR4 is the signal-transducing receptor activated by the bacterial lipopolysaccharide . The activation of TLR4 leads to DNA binding of the transcription factor NF-kappaB, resulting in activation of the inflammatory cascade . Activation of other TLRs is likely to have similar consequences . TLR2 mediates the host response to Gram-positive bacteria and yeast . TLR1 and TLR6 may participate in the activation of macrophages by Gram-positive bacteria, whereas TLR9 appears to respond to a specific sequence of bacterial DNA . The TLRs that control the onset of an acute inflammatory response are critical antecedents for the development of adaptive acquired immunity . Genetic and developmental variation in the expression of microbial pattern recognition receptors may affect the individual's predisposition to infections in childhood and may contribute to susceptibility to severe neonatal inflammatory diseases, allergies, and autoimmune diseases. Hypertension, 2001 Aug, 38(2), 177 - 82 Downregulation of angiotensin II type 1 receptors during sepsis; Bucher M et al.; Our study aimed to characterize the mechanisms underlying the attenuated cardiovascular responsiveness toward the renin-angiotensin system during sepsis . For this purpose, we determined the effects of experimental Gram-negative and Gram-positive sepsis in rats . We found that sepsis led to a ubiquitous upregulation of NO synthase isoform II expression and to pronounced hypotension . Despite increased plasma renin activity and plasma angiotensin (Ang) II levels, plasma aldosterone concentrations were normal, and the blood pressure response to exogenous Ang II was markedly diminished in septic rats . Mimicking the fall of blood pressure during sepsis by short-term infusion of the NO donor sodium nitroprusside in normal rats did not alter their blood pressure response to exogenous Ang II . Therefore, we considered the possibility of an altered expression of Ang II receptors during sepsis . It turned out that Ang II type 1 receptor expression was markedly downregulated in all organs of septic rats . Further in vitro studies with rat renal mesangial cells showed that NO and a combination of proinflammatory cytokines (interleukin-1beta, tumor necrosis factor-alpha, and interferon-gamma) downregulated Ang II type 1 receptor expression in a synergistic fashion . In summary, our data suggest that sepsis causes a systemic downregulation of Ang II type 1 receptors that is likely mediated by proinflammatory cytokines and NO . We suggest that this downregulation of Ang II type 1 receptors is the main reason for the attenuated responsiveness of blood pressure and of aldosterone formation to Ang II and, therefore, contributes to the characteristic septic shock. Curr Opin Ophthalmol, 2001 Aug, 12(4), 282 - 7 Keratoprosthesis: an update; Khan B et al.; Porous polytetrafluoroethylene and polyurethane skirt materials, as well as copolymers of poly (2-hydroxyethyl methacrylate), have shown promise in approaching the goal of a "biointegratable" keratoprosthesis . A novel fixation method that uses scleral haptics also has been introduced to increase stability . An all silicone device that can be sewn into position has been used successfully, temporarily, during vitreoretinal procedures . The prognosis of keratoprosthesis (KPro) procedures depends on the preoperative diagnosis: graft failure-noncicatrizing disease>ocular cicatricial pemphigoid>chemical burns>Stevens-Johnson syndrome . The likelihood of endophthalmitis after KPro surgery follows this scheme . Causative organisms tend to be gram-positive . Modified vitreoretinal techniques also have been developed, allowing successful treatment of posterior segment complications . The science of keratoprosthesis is advancing more rapidly than in previous years . However, use of KPro to address complicated corneal blindness worldwide remains limited . The authors conducted an English language literature review from January 1, 2000 to April 1, 2001 and describe advances of note in the field of keratoprosthesis design, materials, and medical and surgical management. FEMS Microbiol Lett, 2001 Aug 7, 202(1), 1 - 7 Triclosan: a widely used biocide and its link to antibiotics; Schweizer HP; Triclosan is the active ingredient in a multitude of health care and consumer products with germicidal properties, which have flooded the market in recent years in response to the public's fear of communicable bacteria . Although originally thought to kill bacteria by attacking multiple cellular targets, triclosan was recently shown to target a specific bacterial fatty acid biosynthetic enzyme, enoyl-{acyl-carrier protein} reductase, in Gram-negative and Gram-positive bacteria, as well as in the Mycobacteria . Triclosan resistance mechanisms include target mutations, increased target expression, active efflux from the cell, and enzymatic inactivation/degradation . These are the same types of mechanisms involved in antibiotic resistance and some of them account for the observed cross-resistance with antibiotics in laboratory isolates . Therefore, there is a link between triclosan and antibiotics, and the widespread use of triclosan-containing antiseptics and disinfectants may indeed aid in development of microbial resistance, in particular cross-resistance to antibiotics. Acta Odontol Scand, 2001 Jun, 59(3), 124 - 30 Toll-like receptors and their signaling mechanism in innate immunity; Kaisho T et al.; In Drosophila the Toll family, a group of transmembrane proteins, plays crucial roles in the host defense against invading pathogens . Mammalian species also conserve this system as the Toll-like receptor (TLR) family, which includes more than 10 members that have been identified so far . Both the Toll and TLR families recognize various kinds of microorganisms through pathogen-associated molecular patterns . Mammalian TLRs are expressed on macrophages and dendritic cells and mediate the signal for cytokine release or upregulation of costimulatory molecules . These activities cooperatively generate host defense mechanisms . Recently, gene targeting experiments, including ours, have contributed much to clarifying not only the function but also the signaling mechanism of TLRs . TLR2 is essential for recognizing lipopeptides and lipoproteins from several microorganisms and also peptidoglycans derived from gram-positive bacteria . TLR4 recognizes lipopolysaccharides and lipoteichoic acids from gram-negative and- positive bacteria, respectively . Furthermore, TLR9 is critical for recognizing bacterial DNAs . Thus, TLRs distinguish various immunostimulatory molecular patterns . Although TLR9 can produce similar biological responses, studies with mutant mice lacking a TLR-associating protein, MyD88, showed that TLR signaling is differentially regulated among TLR family members . Here, we describe recent progress in elucidating the function and signaling mechanisms of the TLR family. Folia Microbiol (Praha), 2001, 46(1), 71 - 2 Restriction and modification systems of ruminal bacteria; Pristas P et al.; A high frequency of type II restriction endonuclease activities was detected in Selenomonas ruminantium but not in other rumen bacteria tested . Eight different restriction endonucleases were characterized in 17 strains coming from genetically homogeneous local population . Chromosomal DNA isolated from S . ruminantium strains was found to be refractory to cleavage by various restriction enzymes, implying the presence of methylase activities additional to those required for protection against the cellular endonucleases . The presence of Dam methylation was detected in S . ruminantium strains as well as in several other species belonging to the Sporomusa subbranch of low G + C Gram-positive bacteria (Megasphaera elsdenii, Mitsuokella multiacidus). Folia Microbiol (Praha), 2001, 46(1), 45 - 8 Phenotypic and genetic data supporting reclassification of Butyrivibrio fibrisolvens isolates; Kopecny J et al.; Among 55 Butyrivibrio fibrisolvens strains five ribotypes of B . fibrisolvens were described on the basis of RFLP profiles of 16S rDNA regions obtained with restriction endonuclease HaeIII . In the phylogenetic tree, these ribotypes were located in the XIVa cluster of Gram-positive bacteria . Phenotypic differences of selected ribotype groups became the basis for further reclassification of B . fibrisolvens. Transfus Clin Biol, 2001 Jun, 8(3), 278 - 81 Mechanisms of severe transfusion reactions; Kopko PM et al.; Serious adverse effects of transfusion may be immunologically or non-immunologically mediated . Currently, bacterial contamination of blood products, particularly platelets, is one of the most significant causes of transfusion-related morbidity and mortality . Septic transfusion reactions can present with clinical symptoms similar to immune-mediated hemolytic transfusion reactions and transfusion-related acute lung injury . Extremely high fever and/or gastrointestinal symptoms, in a transfusion recipient, may be indicative of sepsis . The diagnosis is based upon culturing the same organism from both the patient and the transfused blood component . Numerous organisms have been implicated as the cause of septic transfusion reactions . Due to different storage conditions, gram negative organisms are more often isolated from red blood cell components; gram positive organisms are more often isolated from platelets . Prevention of septic transfusion reactions is primarily dependent on an adequate donor history and meticulous preparation of the donor phlebotomy site . Visual inspection of blood components prior to transfusion is also vital to preventing these reactions . Several methods of detection of bacterial contamination and inactivation of pathogens are currently under active investigation. Drug Resist Updat, 2000 Jun, 3(3), 178 - 189 beta -Lactamases: which ones are clinically important? Rice LB, Bonomo RA. The introduction of a large array of beta-lactam antibiotics has spawned the emergence of an even larger variety of beta-lactamases designed to confer resistance to these agents . beta-lactamases are produced by both gram-positive and gram-negative bacteria, but their clinical importance is far greater among the gram-negatives . The virtual explosion in our knowledge about the variety of these enzymes can often create confusion and frustration among those not well versed in the field . In this paper, we attempt to focus the discussion of beta-lactamases on those enzymes that are of the greatest clinical importance, the Ambler Class A and C enzymes . We also discuss the growing importance of the Ambler Class B metallo beta-lactamases, which hydrolyze carbapenems and are increasing in prevalence in areas of significant carbapenem usage . Nippon Yakurigaku Zasshi, 2001 Jul, 118(1), 5 - 14 {Induction of histidine decarboxylase in inflammation and immune responses}; Endo Y; Histamine is a classical, but still interesting inflammatory mediator . Many people have long believed that histamine is derived from mast cells or basophils alone . However, the histamine-forming enzyme, histidine decarboxylase (HDC), is induced in a variety of tissues in response (i) to gram-positive and gram-negative bacterial components (lipopolysaccharides, peptidoglycan, and enterotoxin A) and (ii) to various cytokines (IL-1, IL-3, IL-12, IL-18, TNF, G-CSF, and GM-CSF) . HDC is induced even in mast-cell-deficient mice . The histamine newly formed via the induction of HDC is released immediately and may be involved in a variety of immune responses . Reviewing our work and that of Schayer and Kahlson, the pioneers in this field, lead us to the conclusion that nowadays we need to understand that histamine can be produced via the induction of HDC by a mechanism coupled with the cytokine network . We call this histamine "neohistamine", to distinguish it from the classical histamine derived from mast cells or basophils . Neohistamine is involved in physiological reactions, inflammation, immune responses and a variety of diseases such as periodontitis, muscle fatigue (or temporomandibular disorders), stress- or drug-induced gastric ulcers, rheumatoid arthritis, complications in diabetes, hepatitis, allograft rejection, allergic reactions, tumor growth, and inflammatory side effects of aminobisphosphonates. Clin Exp Rheumatol, 2001 Jul-Aug, 19(4), 459 - 62 Widespread nocardiosis in two patients with Behçet's disease; Korkmaz C et al.; Nocardia spp., a group of gram-positive variably acid-fast aerobic bacteria, are opportunistic pathogens in immunocompromised hosts . We here-within describe 2 cases of widespread nocardiosis in patients with Behcet's disease . In addition to endogen endophthalmitis in case 1, both cases developed lung, brain and skin involvement . Despite brain involvement, the prognosis was good, although vision was completely lost in case 1, which was directly attributable to a delay in both diagnosis and treatment. Int J Syst Evol Microbiol, 2001 Jul, 51(Pt 4), 1401 - 3 Facklamia miroungae sp . nov., from a juvenile southern elephant seal (Mirounga leonina); Hoyles L et al.; An unusual gram-positive, catalase-negative, facultatively anaerobic, coccus-shaped organism that originated from a juvenile elephant seal was characterized by phenotypic and molecular taxonomic methods . Comparative 16S rRNA gene sequencing showed that the unknown coccus represents a new subline within the genus Facklamia . The unknown strain was readily distinguishable from all currently recognized species of the genus Facklamia (Facklamia hominis, Facklamia languida, Facklamia ignava, Facklamia sourekii and Facklamia tabacinasalis) by biochemical tests and electrophoretic analysis of whole-cell proteins . Based on phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium be classified as Facklamia miroungae sp . nov . The type strain of F . miroungae is CCUG 42728T (= CIP 106764T) . F . miroungae is the first member of the genus Facklamia to be isolated from an animal other than man. Int J Syst Evol Microbiol, 2001 Jul, 51(Pt 4), 1245 - 56 Alkaliphilus transvaalensis gen . nov., sp . nov., an extremely alkaliphilic bacterium isolated from a deep South African gold mine; Takai K et al.; A novel extreme alkaliphile was isolated from a mine water containment dam at 3.2 km below land surface in an ultra-deep gold mine near Carletonville, South Africa . The cells of this bacterium were straight to slightly curved rods, motile by flagella and formed endospores . Growth was observed over the temperature range 20-50 degrees C (optimum 40 degrees C; 45 min doubling time) and pH range 8.5-12.5 (optimum pH 10.0) . The novel isolate, one of the most alkaliphilic micro-organisms yet described, was a strictly anaerobic chemo-organotroph capable of utilizing proteinaceous substrates such as yeast extract, peptone, tryptone and casein . Elemental sulfur, thiosulfate or fumarate, when included as accessory electron acceptors, improved growth . The G+C content of genomic DNA was 36.4 mol % . Phylogenetic analysis based on the 16S rDNA sequence indicated that the isolate is a member of cluster XI within the low G+C gram-positive bacteria, but only distantly related to previously described members . On the basis of physiological and molecular properties, the isolate represents a novel species, for which the name Alkaliphilus transvaalensis gen . nov., sp . nov . is proposed (type strain SAGM1T = JCM 10712T = ATCC 700919T) . The mechanism of generation of the highly alkaline microbial habitat and the possible source of the alkaliphile are discussed. Clin Infect Dis, 2001 Sep 1, 33 Suppl 2, S84 - 93 Clinical presentations of soft-tissue infections and surgical site infections; Nichols RL et al.; Skin and soft-tissue infections that usually follow minor traumatic events or surgical procedures are caused by a wide spectrum of bacteria . Less frequently, the infections occur spontaneously, which often is clinically confusing and leads to delays in diagnosis . Most of the infections are self-limited and easily treated with local measures and/or antibiotics . Others are life-threatening, requiring prompt diagnosis and aggressive surgical debridement in addition to the wise choice of antibiotic agents to limit tissue loss and preserve life . Many survivors experience critical tissue losses that may require changes in lifestyle as well as major reconstructive cosmetic surgery . Involvement of antibiotic-resistant gram-positive microorganisms in these infections only increases the difficulty of their treatment and may have a significant influence on the ultimate outcome. J Ethnopharmacol, 2001 Sep, 77(1), 5 - 9 An ethnobotanical study of plants used for the treatment of sexually transmitted diseases (njovhera) in Guruve District, Zimbabwe; Kambizi L et al.; The use of medicinal plants in Guruve District, Zimbabwe, contributes significantly to primary health care of the people of the area . This paper presents findings of a survey of plants used for the treatment of sexually transmitted diseases (STDs) in the district . Ethnobotanical information obtained from traditional herbalists and other knowledgeable rural dwellers, has revealed 15 plant species belonging to 10 families as medicinal plants used for the treatment of these infections in the area . Six of these are the commonest and most frequently prescribed by the healers . Roots are the most frequently used parts of the plants constituting 53% of preparations while oral administration of extracts is the main method of prescription . Based on the information gathered from the traditional healers, Acacia nilotica (L.) Willd . ex Delile, Cassia abbreviata Oliv . Dichrostachys cinerea Wight and Arn, Solanum incanum L., Vernonia amygdalina Del . and Zanha africana (Radlk) Excell . are the most frequently used plants for the treatment of STDs . The methanol extracts of Cassia abbreviata, Zanha africana and Acacia nilotica showed significant inhibition against Gram-positive and Gram-negative bacteria, while acetone extracts of these plants inhibited most of the species . Generally the water extracts show less activity than acetone and methanol extracts. Farmaco, 2001 May-Jul, 56(5-7), 447 - 9 Effect of the exposure to gentamicin and diltiazem on the permeability of model membranes; Trombetta D et al.; Preliminary observations showed that the calcium-antagonist diltiazem enhances the 'in vitro' bactericidal action of the aminoglycoside gentamicin, especially against Gram-positive bacteria . To verify if a non-specific interaction of these two drugs with biomembranes may play a role in their synergic effect on bacterial cells, we have studied the effect of exposure to gentamicin, in the absence or presence of diltiazem, on the release of carboxyfluorescein (CF) trapped in phosphatidylcholine (PC) unilamellar vesicles (LUVs) used as model membranes . A significant leakage of trapped CF from PC LUVs was registered when liposomes were treated with gentamicin and diltiazem together, employed at doses (50 and 100 microg/ml, respectively) unable to affect CF release if applied alone; the combined effect of gentamicin and diltiazem was synergic and not cumulative . The present findings demonstrate that the simultaneous exposure to gentamicin and diltiazem may induce significant alterations in the permeability of phospholipid membranes and, so, very likely, in functional properties of bacterial membranes, targets of their action. J Antibiot (Tokyo), 2001 May, 54(5), 441 - 7 TPU-0031-A and B, new antibiotics of the novobiocin group produced by Streptomyces sp . TP-A0556; Sasaki T et al.; Two novel antibiotics, TPU-0031-A and B, were isolated from the culture broth of an actinomycete strain . The producing strain, TP-A0556, was identified as Streptomyces sp . based on the taxonomic study . The new antibiotics were obtained by solvent extraction and chromatographic purification . Spectroscopic analyses showed that TPU-0031-A and B were 7'-demethylnovobiocin and 5"-demethylnovobiocin, respectively . These compounds showed antibiotic activity against Gram-positive and -negative bacteria. FEMS Microbiol Lett, 2001 Jul 24, 201(2), 151 - 5 Methyl chloride utilising bacteria are ubiquitous in the natural environment; McAnulla C et al.; Enrichment and isolation of methyl chloride utilising bacteria from a variety of pristine terrestrial, freshwater, estuarine and marine environments resulted in the detection of six new methyl chloride utilising Hyphomicrobium strains, strain CMC related to Aminobacter spp . and to two previously isolated methyl halide utilising bacteria CC495 and IMB-1, and a Gram-positive isolate SAC-4 phylogenetically related to Nocardioides spp . All the pristine environments sampled for enrichment resulted in the successful isolation of methyl chloride utilising organisms. J Vet Intern Med, 2001 Jul-Aug, 15(4), 394 - 400 Ability of hematologic and serum biochemical variables to differentiate gram-negative and gram-positive mastitis in dairy cows; Smith GW et al.; Medical records of 142 dairy cows with clinical mastitis were examined to determine whether hematologic or serum biochemical results could be used to distinguish between mastitis episodes caused by gram-negative bacteria (n = 78) from those caused by gram-positive bacteria (n = 64) . Signalment, historic information, hematologic and serum biochemical results, milk culture results, and outcome (discharged from hospital or died) were obtained from the medical records . Cows with gram-negative mastitis had significantly (P < .01) lower blood leukocyte, segmented neutrophil, monocyte, and lymphocyte counts and had higher blood hemoglobin concentrations and hematocrits than did cows with gram-positive mastitis . Serum urea nitrogen was the only serum biochemical result associated with pathogen type, and it was higher in cows with gram-negative mastitis than in those with gram-positive mastitis . Mortality rate (25% overall) did not differ between groups . Logistic regression indicated that routine hematologic analysis (segmented neutrophil count, monocyte count, and hemoglobin concentration) was an accurate predictor of gram-negative mastitis, with a sensitivity of .93, a specificity of .89, and an overall accuracy of 91% . The values for sensitivity and specificity were higher than those previously reported for clinical tests differentiating mastitis episodes caused by gram-negative bacteria from those caused by gram-positive bacteria . Our results indicate that routine hematologic analysis is useful for predicting pathogen type in dairy cows with clinical mastitis, thereby facilitating treatment decisions. J Biol Chem, 2001 Sep 14, 276(37), 34686 - 94 Epub 2001 Jul 18. Peptidoglycan recognition proteins: a novel family of four human innate immunity pattern recognition molecules; Liu C et al.; The innate immune system recognizes microorganisms through a series of pattern recognition receptors that are highly conserved in evolution . Insects have a family of 12 peptidoglycan recognition proteins (PGRPs) that recognize peptidoglycan, a ubiquitous component of bacterial cell walls . We report cloning of three novel human PGRPs (PGRP-L, PGRP-Ialpha, and PGRP-Ibeta) that together with the previously cloned PGRP-S, define a new family of human pattern recognition molecules . PGRP-L, PGRP-Ialpha, and PGRP-Ibeta have 576, 341, and 373 amino acids coded by five, seven, and eight exons on chromosomes 19 and 1, and they all have two predicted transmembrane domains . All mammalian and insect PGRPs have at least three highly conserved C-terminal PGRP domains located either in the extracellular or in the cytoplasmic (or in both) portions of the molecules . PGRP-L is expressed in liver, PGRP-Ialpha and PGRP-Ibeta in esophagus (and to a lesser extent in tonsils and thymus), and PGRP-S in bone marrow (and to a lesser extent in neutrophils and fetal liver) . All four human PGRPs bind peptidoglycan and Gram-positive bacteria . Thus, these PGRPs may play a role in recognition of bacteria in these organs. J Fr Ophtalmol, 2001 Jun, 24(6), 597 - 602 {Infectious keratitis after penetrating keratoplasty}; Tixier J et al.; PURPOSE: To investigate the prevalence of microbial keratitis, predisposing risk factors, the spectrum of pathogens and the prognosis for graft survival and visual outcome in patients who developed microbial keratitis following penetrating keratoplasty (PK) . MATERIAL: and methods: We reviewed 16 cases (15 patients) of microbial keratitis after PK . In all cases, corneal scrapings were obtained and microbiologically analyzed . Efficacy of treatment was evaluated by anatomical (clarity of graft) and visual recovery . RESULTS: Principal indications for PK were pseudophakic bullous keratopathy (50%) and microbial keratitis in the previous graft (25%) . Sixty-three per cent of infections occurred within 1 year of PK . Principal predisposing risk factors were suture-related problems (44%) and microbial keratitis in the previous graft (25%) . All of the scrapings were positive according to the microbiological evaluation with gram-positive cocci (64%), gram-positive rods (12%), fungi (18%), and Acanthamoeba (6%) . We found 1 case of polymicrobial infection . Best visual and anatomical results were observed in nonadvanced cases and/or these treated early . After medical and surgical treatments, 8 patients (50%) had a clear graft and 10 patients (63%) had visual acuity less than 20/200 . CONCLUSION: Postoperative control of risk factors and early recognition of infectious complications may decrease the incidence of severe microbial keratitis after PK. Brain, 2001 Aug, 124(Pt 8), 1544 - 54 Bacterial peptidoglycan and immune reactivity in the central nervous system in multiple sclerosis; Schrijver IA et al.; Multiple sclerosis is believed to result from a CD4+ T-cell response against myelin antigens . Peptidoglycan, a major component of the Gram-positive bacterial cell wall, is a functional lipopolysaccharide analogue with potent proinflammatory properties and is conceivably a mediator of sterile inflammation . Here we demonstrate that peptidoglycan is present within antigen-presenting cells in the brain of multiple sclerosis patients . These cells have macrophage and dendritic cell characteristics, and are immunocompetent as evidenced by co-expression of inflammatory cytokines and co-stimulatory molecules . In addition, intrathecal plasma cells specific for peptidoglycan are present in multiple sclerosis brain tissue, and antibodies binding peptidoglycan are present in CSF during active disease . Peptidoglycan may thus contribute to T- and B-cell activity during brain inflammation without a requirement for local bacterial replication. FEMS Microbiol Ecol, 2001 Jul, 36(2-3), 211 - 222 Isolation and characterisation of new Gram-negative and Gram-positive atrazine degrading bacteria from different French soils; Rousseaux S et al.; The capacity of 12 soils to degrade atrazine was studied in laboratory incubations using radiolabelled atrazine . Eight soils showed enhanced degradation of this compound . Twenty-five bacterial strains able to degrade atrazine were isolated by an enrichment method from 10 of these soils . These soils were chosen for their wide range of physico-chemical characteristics . Their history of treatment with atrazine was also variable . The genetic diversity of atrazine degraders was determined by amplified ribosomal restriction analysis (ARDRA) of the 16S rDNA gene with three restriction endonucleases . The 25 bacterial strains were grouped into five ARDRA types . By sequencing and aligning the 16S rDNA genes, the isolates were shown to belong to the Gram-negative species Chelatobacter heintzii, Aminobacter aminovorans, Stenotrophomonas maltophilia and to the Gram-positive genus Arthrobacter crystallopoietes . These species were not described previously as being capable of atrazine degradation . Most Gram-negative bacteria could mineralise (14)C ring labelled atrazine and carried the atzA, atzB, atzC and trzD genes . Gram-positive strains could convert atrazine to cyanuric acid and carried only the atzB and atzC genes . In this study, we describe the atrazine degradation capacities and corresponding genes in bacterial species that were not known as atrazine degraders . We report for the first time the occurrence of the trzD gene in these atrazine-mineralising bacteria and we demonstrate the potential use of colony hybridisation to isolate bacteria involved in atrazine degradation. J Membr Biol, 2001 Jul 15, 182(2), 147 - 57 Study of the properties of a channel-forming protein of the cell wall of the gram-positive bacterium Mycobacterium phlei; Riess FG et al.; The gram-positive bacterium Mycobacterium phlei was treated with detergents . Reconstitution experiments using lipid bilayers suggested that the detergent extracts contain a channel forming protein . The protein was purified to homogeneity by preparative SDS-PAGE and identified as a protein with an apparent molecular mass of about 135 kDa . The channel-forming unit dissociated into subunits with a molecular mass of about 22 kDa when it was boiled in 80% dimethylsulfoxid (DMSO) . The channel has on average a single channel conductance of 4.5 nS in 1 m KCl and is highly voltage-dependent in an asymmetric fashion when the protein is added to only one side of the membrane . Zero-current membrane potential measurements with different salts implied that the channel is highly cation-selective because of negative point charges in or near the channel mouth . Analysis of the single-channel conductance as a function of the hydrated cation radii using the Renkin correction factor and the effect of the negative point charges on the single-channel conductance suggest that the diameter of the cell wall channel is about 1.8 to 2.0 nm . The channel properties were compared with those of other members of the mycolata and suggest that these channels share common features . Southern blots demonstrated that the chromosome of M . phlei and other mycolata tested contain homologous sequences to mspA (gene of the cell wall porin of Mycobacterium smegmatis). Vet Surg, 2001 Jul-Aug, 30(4), 366 - 73 Comparison of two methods for presurgical disinfection of the equine hoof; Hennig GE et al.; OBJECTIVES: To determine for equine hooves the normal resident aerobic bacterial population and the efficacy of 2 methods of disinfection . Study Design-Measurement of total bacterial, gram-positive bacterial, and gram-negative bacterial surface populations from the frog, sole, and hoof wall after each step of 2 different preoperative surgical disinfection techniques . ANIMALS: Six adult horses . METHODS: Hoof wall, sole, and frog samples were collected for quantitative bacteriology before, during, and after 2 multistep antiseptic preparation techniques: Method A-6-minute scrub with povidone-iodine soap, followed by 24-hour submersion in povidone-iodine solution-soaked cotton; and Method B-initial removal of superficial layer of hoof capsule before completing Method A disinfection procedures . RESULTS: Removal of the superficial hoof layer, application of the povidone iodine scrub, and completion of the povidone-iodine soak all significantly (P < .0008) decreased total bacterial numbers . Method B had significantly lower bacterial counts than method A at each consecutive step . Final total bacterial counts remained greater than 10(5) bacteria per gram of tissue regardless of preparation method . CONCLUSIONS: The hoof surface hosts a broad spectrum of aerobic gram-positive and -negative bacteria, many of which are potential pathogens . Bacterial numbers can be significantly reduced by removal of the superficial hoof surface, by application of a povidone-iodine scrub, and by use of a 24-hour povidone-iodine soak . However, bacterial populations >10(5) g per tissue persist after these disinfection procedures . CLINICAL RELEVANCE: Regardless of the preparation methods used in this study, bacterial populations capable of inducing wound infection remain on the hoof capsule . Biotech Histochem, 2001 Jan, 76(1), 15 - 22 Gram staining and lectin binding properties of Myxosporea and Sporozoea; Schachner et al.; The staining method developed by Christian Gram was introduced as a simple and highly selective tool for demonstrating myxosporean and coccidian sporogonic stages . When using standard blood staining procedures for those enigmatic parasites it is sometimes difficult to distinguish them from fish host tissue . They clearly exhibit a partial gram-positive reaction in histological sections, but staining is variable in air dried fish organ imprints . To visualize the gram-negative background of different host tissue components in histological sections, the conventional safranin counterstain of the gram protocol may be modified as follows: after application of 2% crystal violet (basic violet 3) and Lugol's solution, sections are stained with 0.1% nuclear fast red-5% aluminum sulfate and 0.35% aniline blue (acid blue 22) dissolved in saturated aqueous picric acid . Replacement of the gram-specific dye crystal violet with 2% malachite green gave similar results in organ imprints containing myxospores or coccidia, but only in sections containing myxosporea . Staining for 1 min with an aqueous solution of 0.5% malachite green and followed 1 min washing was sufficient for rapidly demonstrating the parasite spores in organ imprints of both myxosores and oocysts . With regard to the role of acid mucopolysaccharides and other carbohydrates in the gram reaction of spores, alcian blue 8GX staining was compared to the binding of FITC-labeled WGA, GS I and GS II . Each lectin was applied at 20 microl/ml PBS, HEPES for 1 hr . Whereas WGA yielded a nonspecific pattern like the alcian blue staining, GS II resulted in a pattern similar to the gram staining results . This binding was weak in untreated specimens, but was significantly enhanced when digested first within trypsin overnight in a humid chamber at 37 degrees C . The binding of GS II to both myxosporidian and coccidian spores suggests that they are both composed of polymers containing N-acetyl-D-glucosamine residues . Furthermore, the results suggest that this hexosamine plays a key role in the gram reaction. Int J Med Microbiol, 2001 May, 291(2), 107 - 17 Regulation of transcription in Helicobacter pylori: simple systems or complex circuits? Scarlato V, Delany I, Spohn G, Beier D. A common strategy used by both Gram-negative and Gram-positive bacterial pathogens is based on the synchronisation of virulence gene expression using a variety of regulatory systems and networks to overcome host defence . During the last decade an exponentially growing number of studies on Helicobacter pylori, a human pathogen associated with diverse stomach diseases, have mainly focussed on the elucidation of mechanisms and functions of virulence factors . A subset of these studies were focussed on the molecular mechanisms regulating gene transcription in H . pylori with the aim of understanding the profound physiological changes that this pathogen, as well as other bacteria, undergoes during infection . Despite the limited number of putative regulatory proteins, as deduced from genome sequence analyses, evidence is accumulating for the existence of new and complex circuits regulating gene transcription and virulence of this bacterium . Here we will focus on the molecular mechanisms used by H . pylori to control gene transcription. Structure (Camb), 2001 Jun, 9(6), 527 - 37 A structural genomics approach to the study of quorum sensing: crystal structures of three LuxS orthologs; Lewis HA et al.; BACKGROUND: Quorum sensing is the mechanism by which bacteria control gene expression in response to cell density . Two major quorum-sensing systems have been identified, system 1 and system 2, each with a characteristic signaling molecule (autoinducer-1, or AI-1, in the case of system 1, and AI-2 in system 2) . The luxS gene is required for the AI-2 system of quorum sensing . LuxS and AI-2 have been described in both Gram-negative and Gram-positive bacterial species and have been shown to be involved in the expression of virulence genes in several pathogens . RESULTS: The structure of the LuxS protein from three different bacterial species with resolutions ranging from 1.8 A to 2.4 A has been solved using an X-ray crystallographic structural genomics approach . The structure of LuxS reported here is seen to have a new alpha-beta fold . In all structures, an equivalent homodimer is observed . A metal ion identified as zinc was seen bound to a Cys-His-His triad . Methionine was found bound to the protein near the metal and at the dimer interface . CONCLUSIONS: These structures provide support for a hypothesis that explains the in vivo action of LuxS . Specifically, acting as a homodimer, the protein binds a methionine analog, S-ribosylhomocysteine (SRH) . The zinc atom is in position to cleave the ribose ring in a step along the synthesis pathway of AI-2. Biochemistry, 2001 Jul 10, 40(27), 7964 - 72 Biosynthesis of D-alanyl-lipoteichoic acid: the tertiary structure of apo-D-alanyl carrier protein; Volkman BF et al.; The D-alanylation of lipoteichoic acid (LTA) allows the Gram-positive organism to modulate its surface charge, regulate ligand binding, and control the electromechanical properties of the cell wall . The incorporation of D-alanine into LTA requires the D-alanine:D-alanyl carrier protein ligase (AMP-forming) (Dcl) and the carrier protein (Dcp) . The high-resolution solution structure of the 81-residue (8.9 kDa) Dcp has been determined by multidimensional heteronuclear NMR . An ensemble of 30 structures was calculated using the torsion angle dynamics approach of DYANA . These calculations utilized 3288 NOEs containing 1582 unique nontrivial NOE distance constraints . Superposition of residues 4-81 on the mean structure yields average atomic rmsd values of 0.43 +/- 0.08 and 0.86 +/- 0.09 A for backbone and non-hydrogen atoms, respectively . The solution structure is composed of three alpha-helices in a bundle with additional short 3(10)- and alpha-helices in intervening loops . Comparisons of the three-dimensional structure with the acyl carrier proteins involved in fatty acid, polyketide, and nonribosomal peptide syntheses support the conclusion that Dcp is a homologue in this family . While there is conservation of the three-helix bundle fold, Dcp has a higher enthalpy of unfolding and no apparent divalent metal binding site(s), features that distinguish it from the fatty acid synthase acyl carrier protein of Escherichia coli . This three-dimensional structure also provides insights into the D-alanine ligation site recognized by Dcl, as well as the site which may bind the poly(glycerophosphate) acceptor moiety of membrane-associated LTA. Turk J Pediatr, 2001 Apr-Jun, 43(2), 105 - 9 Monotherapy with meropenem versus combination therapy with piperacillin plus amikacin as empiric therapy for neutropenic fever in children with lymphoma and solid tumors; Duzova A et al.; The purpose of this study was to compare meropenem monotherapy with combination therapy for empirical treatment of neutropenic fever in children with lymphoma and solid tumors . Ninety episodes of neutropenic fever in children (0.7-16.0; mean age 7.7 years) with solid tumors in a single center were randomized to receive either meropenem (50 mg/kg/dose-maximum 1 g, every 8 hours) or piperacillin (200 mg/kg/dose, every 6 hours) plus amikacin (15 mg/kg daily) . Failure was defined as treatment modification . Non-Hodgkin's lymphoma (NHL) accounted for 62.2 percent of all episodes, and solid tumors (37.8%) for the rest . Blood cultures were positive in 23 percent of all episodes . Sixty-seven percent of all isolated microorganisms stained Gram-positive . Overall success was 70.0 percent (63/90) . The success with meropenem was comparable to that seen with piperacillin plus amikacin: 76.6 versus 64.6 percent (p = 0.25) . The failure rate was 33 percent with Gram-positive culture and 78 percent with Gram-negative or mixed cultures . The solid tumor group had significantly less bacteremia (4/34 versus 17/56; p < 0.05) and treatment failure (3/34 versus 24/56; p < 0.001) than the NHL group . No serious drug-related adverse event was noticed . Meropenem monotherapy was as effective as piperacillin plus amikacin combination in the empirical treatment of neutropenic fever in children with lymphoma and solid tumors. Am J Kidney Dis, 2001 Jul, 38(1), 127 - 31 Cefepime versus vancomycin plus netilmicin therapy for continuous ambulatory peritoneal dialysis-associated peritonitis; Wong KM et al.; Cefepime is a cephalosporin with a broad spectrum of activity against most gram-positive and gram-negative pathogens . In this study, we attempted to compare the safety and efficacy of cefepime monotherapy against the potentially more toxic combination of vancomycin and netilmicin in the treatment of continuous ambulatory peritoneal dialysis (CAPD)-associated bacterial peritonitis . Eighty-one consecutive CAPD patients who presented with peritonitis from January 1, 1998, to June 30, 2000, were recruited for study . Patients were randomized to be administered either intraperitoneal (IP) cefepime, 1 g once daily (group A), or intravenous vancomycin and netilmicin at conventional doses (group B) for 10 days . Bacterial growth was obtained in 52 episodes (66%), and pathogens identified included gram-positive organisms (30 episodes; 38%), gram-negative organisms (14 episodes; 18%), mixed organisms (2 episodes; 2.5%), and fungus (6 episodes; 8%) . Eight patients were excluded after randomization for various reasons (6 patients, fungal peritonitis; 2 patients, wrong diagnoses) . Because of the relatively low peritonitis rate after the use of a disconnect system, the sample size of this study was relatively small, giving a power of 0.45 . There were no significant differences in primary response rates and cure rates (no relapse >28 days after completion of antibiotic therapy) between both groups of patients (group A versus group B, 82% {32 of 39 patients} versus 85% {29 of 34 patients} and 72% {28 of 39 patients} versus 76% {26 of 34 patients}, respectively; P = not significant) . No significant side effect was encountered in either group . Total peritonitis-related hospitalizations were 84 patient-days (1, 7, 8, 11, 20, and 37 patient-days) and 115 patient-days (3, 6, 9, 14, 21, 21, and 41 patient-days), whereas total costs per patient cure were estimated to be US $1,039 and US $1,371 in groups A and B, respectively . We conclude that once-daily 1-g IP cefepime monotherapy is a simple, safe, and cost-effective alternative to vancomycin and netilmicin therapy in the treatment of CAPD-associated bacterial peritonitis. Orthopedics, 2001 Jun, 24(6), 587 - 9 Culture results and amputation rates in high-pressure paint gun injuries of the hand; Mirzayan R et al.; High-pressure paint gun injuries have been well described in the literature, and the use of antibiotics is recommended as part of their management . However, there is no scientific evidence to support the use of antibiotics . In addition, the type of paint injected (water- versus oil-based) has never been investigated to determine the extent of morbidity resulting from these injuries . This study examines the organisms cultured in wounds resulting from these injuries and whether the type of paint injected had an influence on amputation rates . Charts of 35 patients with high-pressure paint gun injuries to their hands were reviewed . The amputation rate was 50% with oil-based paints and 0% with water-based paints . Forty-seven percent of wound cultures were positive, with gram-negative bacteria found in 58% of isolates . Our findings support the use of antibiotics, which should cover both gram-positive and gram-negative organisms. J Mol Biol, 2001 Jul 6, 310(2), 291 - 7 Modular structure, local flexibility and cold-activity of a novel chitobiase from a psychrophilic Antarctic bacterium; Lonhienne T et al.; The gene archb encoding for the cell-bound chitobiase from the Antarctic Gram-positive bacterium Arthrobacter sp . TAD20 was cloned and expressed in Escherichia coli in a soluble form . The mature chitobiase ArChb possesses four functionally independent domains: a catalytic domain stabilized by Ca(2+), a galactose-binding domain and an immunoglobulin-like domain followed by a cell-wall anchorage signal, typical of cell-surface proteins from Gram-positive bacteria . Binding of saccharides was analyzed by differential scanning calorimetry, allowing to distinguish unequivocally the catalytic domain from the galactose-binding domain and to study binding specificities . The results suggest that ArChb could play a role in bacterium attachment to natural hosts . Kinetic parameters of ArChb demonstrate perfect adaptation to catalysis at low temperatures, as shown by a low activation energy associated with unusually low K(m) and high k(cat) values . Thermodependence of these parameters indicates that discrete amino acid substitutions in the catalytic center have optimized the thermodynamic properties of weak interactions involved in substrate binding at low temperatures . Microcalorimetry also reveals that heat-lability, a general trait of psychrophilic enzymes, only affects the active site domain of ArChb . Appl Environ Microbiol, 2001 Jul, 67(7), 2922 - 6 Photosynthetic and phylogenetic primers for detection of anoxygenic phototrophs in natural environments; Achenbach LA et al.; Primer sets were designed to target specific 16S ribosomal DNA (rDNA) sequences of photosynthetic bacteria, including the green sulfur bacteria, the green nonsulfur bacteria, and the members of the Heliobacteriaceae (a gram-positive phylum) . Due to the phylogenetic diversity of purple sulfur and purple nonsulfur phototrophs, the 16S rDNA gene was not an appropriate target for phylogenetic rDNA primers . Thus, a primer set was designed that targets the pufM gene, encoding the M subunit of the photosynthetic reaction center, which is universally distributed among purple phototrophic bacteria . The pufM primer set amplified DNAs not only from purple sulfur and purple nonsulfur phototrophs but also from Chloroflexus species, which also produce a reaction center like that of the purple bacteria . Although the purple bacterial reaction center structurally resembles green plant photosystem II, the pufM primers did not amplify cyanobacterial DNA, further indicating their specificity for purple anoxyphototrophs . This combination of phylogenetic- and photosynthesis-specific primers covers all groups of known anoxygenic phototrophs and as such shows promise as a molecular tool for the rapid assessment of natural samples in ecological studies of these organisms. Res Microbiol, 2001 Apr-May, 152(3-4), 231 - 43 A new family of high-affinity ABC manganese and zinc permeases; Claverys JP; Phylogenetic analysis of 47 extracellular putative metal binding receptors (MBRs) belonging to the newly defined cluster suggests the existence of two subclusters . The question of substrate specificity of the corresponding ATP binding cassette (ABC) permeases is discussed, based on data collected from 19 of them concerning their regulation, metal requirement of permease mutants, metal uptake and metal binding . The proposal that the two subclusters correspond to paralogous metal permeases dedicated primarily to manganese and to zinc transport is made . The question of a direct role of MBRs as adhesins of Gram-positive bacteria is then discussed and the importance of metal permeases for cellular processes and host-bacteria interactions is reviewed. Retina, 2001, 21(3), 210 - 3 Intraocular vancomycin levels after intravitreal injection in post cataract extraction endophthalmitis; Haider SA et al.; PURPOSE: Intravitreal antibiotics are the mainstay of treatment of endophthalmitis following cataract surgery . The purpose of this study is to determine the range of intraocular vancomycin found after intravitreal therapy and assess the optimum time for repeat injections . METHODS: Aqueous and vitreous vancomycin was assayed at the time of reinjection in 14 patients with endophthalmitis showing a poor clinical response after their primary injection . Nine patients received vancomycin 2 mg and another five received vancomycin 1 mg . In six patients the injection was repeated at 48 hours and in seven at 72 hours . Two patients received three injections . RESULTS: Aqueous vancomycin varied from 8.4 to 170 mg/L and the vitreous vancomycin level ranged from 21.2 to 220 mg/L . CONCLUSIONS: In the current study vitreous vancomycin levels were variable, but well within the therapeutic range for sensitive Gram-positive organisms . At times they exceeded the putative retinotoxic levels (100 mg/L) . Higher aqueous levels were found after an injection of 2 mg than after 1 mg . Vancomycin levels were still very high 3 days after injection of 2 mg where results were available . Assay at the time of repeat injection may provide insight into the adequacy of vitreous levels and guide future therapy. J Dairy Sci, 2001 Jun, 84(6), 1407 - 12 Influence of subclinical mastitis during early lactation on reproductive parameters; Schrick FN et al.; Our objective was to determine the effects of mastitis during early lactation on the reproductive performance of Jersey cows . From 1986 to 1997, quarter foremilk samples were collected every 4 to 8 wk during lactation, at drying off, near calving, and when clinical mastitis was diagnosed and were evaluated microbiologically to identify causative bacteria . Services per conception, days open, and days to first service were obtained from DHIA records on 752 cows . Cows were separated by mastitis type (clinical, n = 186; subclinical, n = 240; control, uninfected or infected after confirmed pregnancy, n = 326) . Cows were reclassified based on the time of clinical or subclinical mastitis as follows: period 1, before first service (n = 374); period 2, between first service and pregnancy (n = 52); and period 3, after confirmed pregnancy or uninfected (control; n = 326) . Milk production did not differ for any group separations . Reproductive performance did not differ between gram-negative or gram-positive mastitis pathogens . Cows with clinical or subclinical mastitis before first service had increased days to first service (77.3+/-2.7 and 74.8+/-2.7 d), days open (110.0+/-6.9 and 107.7+/-6.9 d), and services per conception (2.1+/-0.2 and 2.1+/-0.2) compared with controls (67.8+/-2.2 d, 85.4+/-5.8 d, 1.6+/-0.2; P < 0.05) . Days to first service were not increased in cows with clinical or subclinical mastitis during period 2 (70.6+/-3.3 and 61.2+/-7.8 d) . However, days open (143.6+/-8.5 d) and services per conception (3.0+/-0.2) were increased (P < 0.05) in cows with clinical mastitis during period 2, but not in cows with subclinical mastitis (90.9+/-20.2 d and 2.1+/-0.5) . Cows initially diagnosed subclinical that became clinical during period 2 exhibited increased days to first service (93.9+/-10.1 d), days open (196.0+/-26.2 d), and services per conception (4.3+/-0.7) compared with control animals (P < 0.05) . In conclusion, subclinical mastitis reduced reproductive performance of lactating cows similar to clinical mastitis . Subclinical mastitis followed by clinical mastitis resulted in the most severe loss in reproductive performance. J Agric Food Chem, 2001 Jun, 49(6), 2830 - 4 Reaction of B . cereus bacteria and peroxidase enzymes under pressures >400 MPa; Prestamo G et al.; It is known that B . cereus (Gram-positive bacteria) and peroxidase enzymes are resistant to pressures of approximately 400 MPa in fruit and vegetable products among others . The aim of the present work is to have knowledge about their behavior when using pressures >400 MPa without other combined treatments . The results showed that B . cereus was not inactivated at pressures of 1000 MPa for 15 min at 20 degrees C . In peroxidase enzymes the results remained similar and the pressure of 1000 MPa for 30 min was not enough to inactivate them . The apple cell structure at these high-pressure levels revealed that it changed and the cells were less cemented . The treated apple presented a translucent aspect, and some fluids migrated from the inside to the outside of the cell. Curr Biol, 2001 Apr 3, 11(7), R264 - 7 Bacterial pathogenesis: the answer to virulence is in the pore; Gauthier A et al.; A wide variety of Gram-negative bacterial pathogens use a 'type III' protein secretion system to deliver bacterial virulence factors into host cells . Recent results suggest that Gram-positive pathogens may employ similar methods to deliver virulence factors into host cells. Int J Syst Evol Microbiol, 2001 May, 51(Pt 3), 937 - 44 Proposal of Mycetocola gen . nov . in the family Microbacteriaceae and three new species, Mycetocola saprophilus sp . nov., Mycetocola tolaasinivorans sp . nov . and Mycetocola lacteus sp . nov., isolated from cultivated mushroom, Pleurotus ostreatus; Tsukamoto T et al.; The taxonomic positions of 10 tolaasin-detoxifying bacteria, which were isolated from the cultivated mushroom Pleurotus ostreatus, were investigated . These strains are Gram-positive, obligately aerobic, non-sporulating and irregular rod-shaped bacteria . They have the following characteristics: the major menaquinone is MK-10, the DNA G+C content ranges from 64 to 65 mol%, the diamino acid in the cell wall is lysine and the muramic acid in the peptidoglycan is an acetyl type . The major fatty acids are anteiso-C15:0 and anteiso-C17:0 . On the basis of morphological, physiological and chemotaxonomic characteristics, together with DNA-DNA reassociation values and 16S rRNA gene sequence comparison data, the new genus Mycetocola gen . nov . is proposed for these bacteria in the family Microbacteriaceae and three new species are also proposed: Mycetocola saprophilus sp . nov . (type strain CM-01T = IFO 16274T = MAFF 211324T = NRRL B-24119T), Mycetocola tolaasinivorans sp . nov . (type strain CM-05T = IFO 16277T = MAFF 211325T = NRRL B-24120T) and Mycetocola lacteus sp . nov . (type strain CM-10T = IFO 16278T = MAFF 211326T = NRRL B-24121T) . The type species of the genus is Mycetocola saprophilus sp . nov. Int J Syst Evol Microbiol, 2001 May, 51(Pt 3), 933 - 6 Nocardia veterana sp . nov., isolated from human bronchial lavage; Gurtler V et al.; A nocardioform bacterium was isolated from the bronchoscopic lavage of a 78-year-old man with a past history of tuberculous pleurisy, who presented with bilateral upper lobe lesions at Austin and Repatriation Medical Centre, Heidelberg, Australia . The strain was aerobic, Gram-positive, produced beige substrate mycelium and scant white aerial mycelium . It showed chemotaxonomic markers which were consistent with the classification of Nocardia: i.e . meso-diaminopimelic acid, N-glycolylmuramic acid, arabinose and galactose as diagnostic sugars; phospholipids phosphatidylinositol mannosides, phosphatidylinositol, phosphatidylethanolamine and diphosphatidylglycerol; a menaquinone with a cyclic isoprene side chain, MK-8(H4cycl.); a fatty acid pattern composed of unbranched saturated and monounsaturated fatty acids with a considerable amount of tuberculostearic acid; and mycolic acids composed of 54-62 carbon atoms with three principal mycolic acids which were mono- and polyunsaturated, showing a chain length C56, C58 and C60 and accounting for over 70% of the entire pattern . The 16S rDNA sequence showed the highest similarity to the type strain of Nocardia vaccinii; the DNA-DNA similarity of the two strains was 31% . These data, together with distinct physiological traits and molecular biological analyses, as well as chemotaxonomic results, led to the conclusion that the novel isolate represents a new species within the genus Nocardia for which the name Nocardia veterana sp . nov . is proposed . The type strain is M157222T (DSM 44445T = NRRL B-24136T). Chem Biol, 2001 Jun, 8(6), 593 - 611 Structure-based design and in-parallel synthesis of inhibitors of AmpC beta-lactamase; Tondi D et al.; BACKGROUND: Group I beta-lactamases are a major cause of antibiotic resistance to beta-lactams such as penicillins and cephalosporins . These enzymes are only modestly affected by classic beta-lactam-based inhibitors, such as clavulanic acid . Conversely, small arylboronic acids inhibit these enzymes at sub-micromolar concentrations . Structural studies suggest these inhibitors bind to a well-defined cleft in the group I beta-lactamase AmpC; this cleft binds the ubiquitous R1 side chain of beta-lactams . Intriguingly, much of this cleft is left unoccupied by the small arylboronic acids . RESULTS: To investigate if larger boronic acids might take advantage of this cleft, structure-guided in-parallel synthesis was used to explore new inhibitors of AmpC . Twenty-eight derivatives of the lead compound, 3-aminophenylboronic acid, led to an inhibitor with 80-fold better binding (2; K(i) 83 nM) . Molecular docking suggested orientations for this compound in the R1 cleft . Based on the docking results, 12 derivatives of 2 were synthesized, leading to inhibitors with K(i) values of 60 nM and with improved solubility . Several of these inhibitors reversed the resistance of nosocomial Gram-positive bacteria, though they showed little activity against Gram-negative bacteria . The X-ray crystal structure of compound 2 in complex with AmpC was subsequently determined to 2.1 A resolution . The placement of the proximal two-thirds of the inhibitor in the experimental structure corresponds with the docked structure, but a bond rotation leads to a distinctly different placement of the distal part of the inhibitor . In the experimental structure, the inhibitor interacts with conserved residues in the R1 cleft whose role in recognition has not been previously explored . CONCLUSIONS: Combining structure-based design with in-parallel synthesis allowed for the rapid exploration of inhibitor functionality in the R1 cleft of AmpC . The resulting inhibitors differ considerably from beta-lactams but nevertheless inhibit the enzyme well . The crystal structure of 2 (K(i) 83 nM) in complex with AmpC may guide exploration of a highly conserved, largely unexplored cleft, providing a template for further design against AmpC beta-lactamase. Crit Care Med, 2001 Jun, 29(6), 1101 - 8 Impact of a rotating empiric antibiotic schedule on infectious mortality in an intensive care unit; Raymond DP et al.; OBJECTIVE: The development of antibiotic-resistant bacteria is associated with significant morbidity and mortality in critically ill patients . We postulated that quarterly rotation of empirical antibiotics could decrease infectious complications from resistant organisms in an intensive care unit (ICU) . DESIGN: Prospective cohort study . SETTING: An ICU at a university medical center . SUBJECTS: All patients admitted to the general, transplant, or trauma surgery services who developed pneumonia, peritonitis, or sepsis of unknown origin . INTERVENTIONS: A 2-yr study consisting of 1 yr of nonprotocol-driven antibiotic use and 1 yr of rotating empirical antibiotic assignment . MEASUREMENTS AND MAIN RESULTS: Over 100 variables were recorded for each infectious episode, including patient characteristics (e.g., Acute Physiology and Chronic Health Evaluation {APACHE} II score, age, comorbidities), infection characteristics (e.g., site, organism), treatment characteristics (e.g., antibiotic, treatment duration) and outcome measures (e.g., mortality, length of stay, antibiotic cost) . Of 1456 consecutive admissions to the ICU, 540 episodes of infection were treated . No differences were noted in age, APACHE II score, race, overall antibiotic utilization or duration of therapy between the 2 yrs of study . Outcome analysis revealed significant reductions in the incidence of antibiotic-resistant Gram-positive coccal infections (7.8 infections/100 admissions vs . 14.6 infections/100 admissions, p <.0001), antibiotic-resistant Gram-negative bacillary infections (2.5 infections/100 admissions vs . 7.7 infections/100 admissions, p <.0001), and mortality associated with infection (2.9 deaths/100 admissions vs . 9.6 deaths/100 admissions, p <.0001) during rotation . Logistic regression identified age (odds ratio {OR}, 1.03; 95% confidence interval {CI}, 1.01-1.06), APACHE II score (OR, 1.06; 95% CI, 1.01-1.13), solid organ transplantation (OR, 9.50; 95% CI, 2.01-52.21), and malignancy (OR, 10.16; 95% CI, 4.11-26.96) as independent predictors of mortality . Antibiotic rotation was an independent predictor of survival (OR 6.27, 95% CI 2.78-14.16) . CONCLUSION: Rotation of empirical antibiotic therapy seems to be a promising method to reduce infectious mortality in an ICU. J Immunol, 2001 Jun 15, 166(12), 7319 - 26 Characterization of a pattern recognition protein, a masquerade-like protein, in the freshwater crayfish Pacifastacus leniusculus; Lee SY et al.; A multifunctional masquerade-like protein has been isolated, purified, and characterized from hemocytes of the freshwater crayfish, Pacifastacus leniusculus . It was isolated by its Escherichia coli binding property, and it binds to formaldehyde-treated Gram-negative bacteria as well as to yeast, Saccharomyces cerevisiae, whereas it does not bind to formaldehyde-fixed Gram-positive bacteria . The intact masquerade (mas)-like protein is present in crayfish hemocytes as a heterodimer composed of two subunits with molecular masses of 134 and 129 kDa . Under reducing conditions the molecular masses of the intact proteins are not changed . After binding to bacteria or yeast cell walls, the mas-like protein is processed by a proteolytic enzyme . The 134 kDa of the processed protein yields four subunits of 65, 47, 33, and 29 kDa, and the 129-kDa protein results in four subunits of 63, 47, 33, and 29 kDa in 10% SDS-PAGE under reducing conditions . The 33-kDa protein could be purified by immunoaffinity chromatography using an Ab to the C-terminal part of the mas-like protein . This subunit of the mas-like protein has cell adhesion activity, whereas the two intact proteins, 134 and 129 kDa, have binding activity to LPSs, glucans, Gram-negative bacteria, and yeast . E . coli coated with the mas-like protein were more rapidly cleared in crayfish than only E . coli, suggesting this protein is an opsonin . Therefore, the cell adhesion and opsonic activities of the mas-like protein suggest that it plays a role as an innate immune protein. J Trauma, 2001 May, 50(5), 810 - 6 Early elevation of soluble CD14 may help identify trauma patients at high risk for infection; Carrillo EH et al.; BACKGROUND: Elevated levels of soluble CD14 (sCD14) have been implicated in both gram-positive and gram-negative sepsis, and it has been associated with high mortality in trauma patients who become infected . METHODS: Eleven healthy volunteers and 25 adult trauma patients with multiple injuries and a mean Injury Severity Score of 32 participated . Whole blood was obtained at intervals . Immunohistochemistry was used to quantify membrane CD14 (mCD14), by flow cytometry and plasma levels of sCD14 by enzyme-linked immunosorbent assay . Analysis of variance and Student's T test with Mann-Whitney posttest were used to determine significance at p < 0.05 . RESULTS: On posttrauma day 1, sCD14 was significantly different in the plasma of infected patients compared with normal controls (7.16 +/- 1.87 microg/mL vs . 4.4 +/- 0.92 microg/mL, p < 0.01), but not significantly different from noninfected patients . The percentage of monocytes expressing mCD14 in trauma patients did not differentiate them from normal controls; however, mCD14 receptor density did demonstrate significance in septic trauma patients (n = 15) versus normal controls on posttrauma day 3 (p = 0.0065) . CONCLUSION: On the basis of our data, mCD14 did not differentiate infected and noninfected trauma patients, although trauma in general reduced mCD14 and elevated sCD14 . Interestingly, 100% of patients who exceeded plasma levels of 8 microg/mL of sCD14 on day 1 after injury developed infections . Therefore, early high expressers of sCD14 may be at higher risk for infectious complications after trauma. Water Sci Technol, 2001, 43(1), 77 - 82 Study of microbial community of brewery-treating granular sludge by denaturing gradient gel electrophoresis of 16S rRNA gene; Chan OC et al.; The microbial community structure of granular sludge from an upflow anaerobic sludge blanket (UASB) reactor treating brewery effluent was studied by denaturing gradient gel electrophoresis (DGGE) . Twelve major bands were observed in the DGGE fingerprint for the Bacteria domain and four bands for the Archaea domain . Of the bacterial bands observed, six were successfully purified and sequenced . Among them, three were related to the gram-positive low G + C group, one to the Delta subclass of the Proteobacteria, one to the Gamma subclass, and one to the Cytophaga group with no close related sequence . The 16S rRNA sequences of the four archaeal bands were closely associated with Methanosaeta concilii and Methanobacterium formicum. J Int Assoc Physicians AIDS Care, 1996 Apr, 2(4), 35 - 7 Macrolides, azalides, and streptogrammins; Prescott LM; AIDS: The Third International Conference on the Macrolides, Azalides, and Streptogramins was held in Lisbon, Portugal . Conferees were given news on the latest advances in the development of innovative antibiotics belonging to these increasingly important groups of drugs, and learned of their expanding clinical indications . The following areas were emphasized at the conference: multiresistant gram-positive bacteremias in patients with serious underlying infections, azithromycin's effectiveness against acute community-acquired pneumonia, results of clarithromycin plus ethambutol in HIV-infected patients with MAC bacteremia, duodenal ulcers associated with Helicobacter pylori infections, and use of roxithromycin against AIDS-related cryptosporidium diarrhea . J Mol Microbiol Biotechnol, 2001 Jul, 3(3), 401 - 13 Hierarchical control versus autoregulation of carbohydrate utilization in bacteria; Gunnewijk MG et al.; The involvement of phosphoeno/pyruvate:sugar phosphotransferase (PTS) proteins, like HPr and IIA(Glc), in the regulation of carbohydrate utilization has been well established in Gram-negative and Gram-positive bacteria . The majority of the studies of PTS-mediated regulation have been concerned with the hierarchical control of carbohydrate utilization, which results in the preferential utilization of a particular carbohydrate from a mixture of substrates . The underlying mechanisms of PTS-mediated hierarchical control involve the inhibition of expression of other catabolic enzymes and transporters and/or the allosteric regulation of their activity, which prevents the transcriptional inducer to be formed or taken up into the cell . More recently, it has become clear that PTS components allow also the cell to tune the uptake rate(s) to the carbohydrate availability in the medium and the metabolic capacity of the cell . The different phosphorylated species of HPr play a central role in this autoregulatory control circuit, both at the gene and at the protein level . Our knowledge of hierarchical control and autoregulation of carbohydrate utilization in bacteria is discussed. J Immunol, 2001 Jun 1, 166(11), 6855 - 60 Bacterial DNA and lipopolysaccharide induce synergistic production of TNF-alpha through a post-transcriptional mechanism; Gao JJ et al.; LPS is well recognized for its potent capacity to activate mouse macrophages to produce TNF-alpha, an important inflammatory mediator in bacterial infection-related diseases such as septic shock . We demonstrate here that while inducing only low levels of TNF-alpha alone, DNA from both Gram-negative and Gram-positive bacteria synergizes with subthreshold concentrations of LPS (0.3 ng/ml) to induce TNF-alpha in the RAW 264.7 macrophage-like cell line . The bacterial DNA effects are mimicked by synthetic CpG-containing oligodeoxynucleotides, but not non-CpG-containing oligodeoxynucleotides . Pretreatment of macrophages with either DNA for 2-8 h inhibits macrophage TNF-alpha production in responses to DNA/LPS . However, when pretreatment was extended to 24 h, DNA/LPS synergy on TNF-alpha is further enhanced . RT-PCR analysis indicates that mRNA levels of the TNF-alpha gene, however, are not synergistically induced by bacterial DNA and LPS . Analyses of the half-life of TNF-alpha mRNA indicate that TNF-alpha message has a longer half-life in bacterial DNA- and LPS-treated macrophages than that in bacterial DNA- or LPS-treated macrophages . These findings indicate that the temporally controlled, synergistic induction of TNF-alpha by bacterial DNA and LPS is not mediated at the transcriptional level . Instead, this synergy may occur via a post-transcriptional mechanism. Arch Surg, 2001 May, 136(5), 592 - 6 Pancreatic infection in severe pancreatitis: the role of fungus and multiresistant organisms; Gloor B et al.; HYPOTHESIS: Recent controlled clinical studies suggest a positive effect of early antibiotic treatment on late morbidity and mortality in severe acute pancreatitis . However, widespread use of antibiotics may lead to an increased number of fungal infections and multiresistant bacteria, thereby worsening the outcome of the disease . DESIGN: Single-center prospective study . SETTING: University hospital, gastrointestinal surgical service . PATIENTS: One hundred three patients with necrotizing pancreatitis seen consecutively in our service . INTERVENTIONS: In addition to standard treatment, patients with proven necrotizing pancreatitis received a prophylactic intravenous antibiotic treatment . Pancreatic infection was regarded as an indication for surgery . MAIN OUTCOME MEASURES: Pancreatic infection, microbiological findings, drug resistance, fungal infections . RESULTS: Thirty-three patients (32%) had infected necrosis . Gram-negative organisms were isolated from 19 patients (58%), Gram-positive organisms were isolated from 18 patients (55%), fungal organisms were isolated from 8 patients (24%), and multiresistant organisms were isolated from 3 patients (9%) . In 7 patients (21%), the organisms cultured from the pancreatic tissue were resistant to the antibiotics given in for prophylaxis . Infection with multiresistant organisms or organisms resistant to the antibiotic used for prophylaxis, but not with fungal infection or Gram-positive or Gram-negative infection, was correlated with a negative outcome . CONCLUSIONS: Fungal infection under adequate treatment is not associated with a negative outcome . The occurrence of multiresistant organisms seems to be a rare finding (3 of 103 patients) . Antibiotic prophylaxis is effective in preventing infection in necrotizing pancreatitis, but optimal choice and duration of administration of the antibiotic agent(s) need to be carefully determined to avoid the sequelae of multiresistant organisms. Clin Ther, 2001 Apr, 23(4), 566 - 77 Pharmacokinetics and tolerability of extended-release clarithromycin; Guay DR et al.; BACKGROUND: Clarithromycin is a semisynthetic macrolide that exhibits broad-spectrum activity against gram-positive, gram-negative, and atypical respiratory tract and skin/skin structure pathogens, Mycobacterium species, and Helicobacter pylori . It is indicated for the treatment of a wide variety of respiratory and dermatologic infections in children and adults as well as prophylaxis and treatment of Mycobacterium avium complex infection and peptic ulcers due to H . pylori . OBJECTIVE: In this article, we review the results of 3 studies of the steady-state pharmacokinetic profiles of clarithromycin and 14(R)-hydroxy-clarithromycin after multiple oral once-daily doses of 500-mg extended-release (ER) clarithromycin tablets . We also review the drug tolerability in 2 phase III comparative clinical trials of immediate-release (IR) and ER clarithromycin conducted in adults with acute maxillary sinusitis (AMS) and acute exacerbation of chronic bronchitis (AECB) . METHODS: In the 3 pharmacokinetic studies, multiple-dose regimens of clarithromycin IR (one 250-mg or 500-mg tablet twice daily) and clarithromycin ER (one or two 500-mg tablets once daily), administered to healthy male and female volunteers, were evaluated . The effect of administration in nonfasting versus fasting conditions was assessed as well . Tolerability information was collected from each adult patient enrolled in phase III efficacy studies conducted to support the application for US Food and Drug Administration approval for the treatment of AMS and AECB . Regimens evaluated were 500 mg IR clarithromycin tablets twice daily or 1000 mg (2 x 500 mg) ER clarithromycin tablets once daily for 7 days (AECB) or 14 days (AMS) . RESULTS: Bioavailability of the ER clarithromyin tablet administered with food was equivalent to that of the reference IR tablet, based on area under the plasma concentration-time curve (AUC) for both parent compound and active metabolite . The bioavailability of the ER tablet was 30% lower (based on clarithromycin AUC) when administered under fasting versus nonfasting conditions . Compared with the IR tablet, administration of the ER tablet resulted in significantly lower (P < 0.05) clarithromycin peak plasma concentration (Cmax), delayed time to Cmax, and lower degree of concentration fluctuation, confirming its in vivo extended-release characteristics . The most frequently reported adverse events (AEs) in the phase III clinical trials were diarrhea, abnormal taste, and nausea and were generally mild or moderate . The incidence of AEs was comparable for the 2 formulations . The severity of gastrointestinal AEs was significantly less for the ER formulation than for the IR formulation (P = 0.018), as was the frequency of premature study discontinuation due to gastrointestinal AEs or abnormal taste (P = 0.004) . CONCLUSIONS: The results from the 3 pharmacokinetic studies reviewed demonstrate the bioequivalence of the ER and IR formulations and support the use of this clarithromycin ER formulation in a once-daily dosing regimen in phase III clinical trials . The ER tablet should be taken with food to maximize bioavailability . The results of 2 phase III comparative clinical efficacy and safety trials of clarithromycin ER tablets versus IR tablets in AMS and AECB confirm the good tolerability of the ER formulation. Antimicrob Agents Chemother, 2001 Jun, 45(6), 1843 - 6 Pharmacokinetics and tissue penetration of linezolid following multiple oral doses; Gee T et al.; The pharmacokinetics of multiple-dose linezolid were determined following administration of five 600-mg oral doses given every 12 h to each of six healthy male volunteers . Concentrations of the drug were determined in plasma and inflammatory blister fluid using high-pressure liquid chromatography . A mean peak concentration in plasma of 18.3 microg/ml (standard deviation {SD}, 6.0) was attained at a mean time of 0.7 h (SD, 0.3) after the final dose . The penetration into the inflammatory fluid was 104% (SD, 20.7) . A mean peak concentration of 16.4 microg/ml (SD, 10.6) was attained in the inflammatory fluid at 3 h (SD, 0.6) after the final dose . The elimination half-life from serum and inflammatory fluid was 4.9 (SD, 1.8) and 5.7 (SD, 1.7) h, respectively . The area under the concentration-time curve in plasma and blister fluid was 140.3 (SD, 73.1) and 155.3 (SD, 80.1) microg x h/ml, respectively . These data suggest that linezolid has good tissue penetration, and we can predict that it will be successful in the treatment of a variety of gram-positive infections. Przegl Epidemiol, 2000, 54(3-4), 305 - 13 {Microorganisms in clinical material collected from patients at the Public Clinical Hospital Nr 1 in Gdansk from 1997-1999}; Samet A et al.; Occurrence of microorganisms isolated from clinical specimens collected from patients in Clinical Hospital no . 1 in Gdansk in years 1997-1999 was analyzed . In this period there was no change in occurrence of Gram-negative bacteria, that accounted for 44-46% isolates . The number of isolations of Gram-positive bacteria dropped from 45% to 40%, and yeast risen from 5% to 10% . The analysis of blood cultures shows decrease in occurrence of bacteremia caused by Gram-negative bacteria and increase in occurrence bacteremia caused by Gram-positive bacteria and yeast . We observed also that the number of multi-resistant Gram-positive isolates (MRSA, VRE) decreased but there was rise in occurrence of multiresistant Gram-negative isolates (ESBL+, CRPA). FEMS Microbiol Rev, 2001 May, 25(3), 269 - 84 Cell wall teichoic acids: structural diversity, species specificity in the genus Nocardiopsis, and chemotaxonomic perspective; Naumova IB et al.; Data on the structures of cell wall teichoic acids, the anionic carbohydrate-containing polymers, found in many Gram-positive bacteria have been summarized and the polymers of the actinomycete genus Nocardiopsis have been considered from the taxonomic standpoint . The structures of these polymers or their combinations have been demonstrated to be indicative of each of seven Nocardiopsis species and two subspecies, verified by the DNA-DNA relatedness data, and to correlate well with the grouping of the organisms based on 16S rDNA sequences . As each of the intrageneric taxa discussed is definable by the composition of teichoic acids, the polymers are considered to be valuable taxonomic markers for the Nocardiopsis species and subspecies . The (13)C NMR spectra of the polymers, data on the products of their chemical degradation, and distinguishing constituents of whole cell walls derived from teichoic acids are discussed, which are useful for identification of certain polymers and members of the genus Nocardiopsis at the species and subspecies level in microbiological practice. J Cardiovasc Pharmacol, 2001 May, 37(5), 548 - 63 Cardiovascular sympathomimetic amine interactions in rats treated with monoamine oxidase inhibitors and the novel oxazolidinone antibiotic linezolid; Humphrey SJ et al.; Linezolid (PNU-100766) is a new gram-positive oxazolidinone antibiotic that is effective at in vitro concentrations < or =4 microg/ml and in vivo doses < or =10 mg/kg . Because linezolid also competitively inhibits human monoamine oxidase-A (MAO-A; Ki = 55 microM), we monitored its effects on the cardiovascular responses to tyramine and amine cold remedies in comparison with standard MAO inhibitors . In anesthetized rats, the pressor response to 16 microg i.v . tyramine was potentiated by the MAO-A inhibitors clorgyline (0.1-1.0 mg/kg i.v.) and moclobemide (5.0-50 mg/kg p.o.), but not by the MAO-B inhibitor selegiline (0.15-15 mg/kg p.o.) . Fifteen milligrams per kilogram intravenous linezolid weakly potentiated i.v . tyramine independent of changes in alpha-adrenoceptor reactivity, but this effect was not enhanced chronically (90-100 mg/kg/day) . In conscious rats, 30 mg/kg/day oral linezolid (8 microg/ml plasma concentration) minimally affected the pressor response to 20 mg/kg oral tyramine, whereas 100 mg/kg/day linezolid (20 microg/ml plasma concentration) moderately potentiated this response similar to 3 mg/kg per day moclobemide . Linezolid's tyramine potentiation was reversible, attenuated by food, and independent of pseudoephedrine, phenylpropanolamine, and dextromethorphan interactions . These studies demonstrate that high-dose linezolid only moderately potentiates the cardiovascular effects of tyramine and validate these models for evaluating such MAO inhibitory interactions. Biochim Biophys Acta, 2001 Jun 1, 1505(2-3), 185 - 208 A novel scenario for the evolution of haem-copper oxygen reductases; Pereira MM et al.; The increasing sequence information on oxygen reductases of the haem-copper superfamily, together with the available three-dimensional structures, allows a clear identification of their common, functionally important features . Taking into consideration both the overall amino acid sequences of the core subunits and key residues involved in proton transfer, a novel hypothesis for the molecular evolution of these enzymes is proposed . Three main families of oxygen reductases are identified on the basis of common features of the core subunits, constituting three lines of evolution: (i) type A (mitochondrial-like oxidases), (ii) type B (ba3-like oxidases) and (iii) type C (cbb3-type oxidases) . The first group can be further divided into two subfamilies, according to the helix VI residues at the hydrophobic end of one of the proton pathways (the so-called D-channel): (i) type A1, comprising the enzymes with a glutamate residue in the motif -XGHPEV-, and (ii) type A2, enzymes having instead a tyrosine and a serine in the alternative motif -YSHPXV- . This second subfamily of oxidases is shown to be ancestor to the one containing the glutamate residue, which in the Bacteria domain is only present in oxidases from Gram-positive or purple bacteria . It is further proposed that the Archaea domain acquired terminal oxidases by gene transfer from the Gram-positive bacteria, implying that these enzymes were not present in the last common ancestor before the divergence between Archaea and Bacteria . In fact, most oxidases from archaea have a higher amino acid sequence identity and similarity with those from bacteria, mainly from the Gram-positive group, than with oxidases from other archaea . Finally, a possible relation between the dihaemic subunit (FixP) of the cbb3 oxidases and subunit II of caa3 oxidases is discussed . As the families of haem-copper oxidases can also be identified by their subunit II, a parallel evolution of subunits I and II is suggested. South Med J, 2001 Apr, 94(4), 438 - 40 Rothia dentocariosa endocarditis complicated by multiple intracranial hemorrhages; Ricaurte JC et al.; Rothia dentocariosa is a gram-positive rod found commonly as part of the normal flora of the mouth . It rarely causes clinical disease . Subacute infective endocarditis has been the most commonly reported R dentocariosa infection, and extracardiac complications occur frequently . Solitary intracranial hemorrhages have been reported in two cases . We describe the first case of infective endocarditis complicated by the sequential and unusually prolonged development of multiple new intracranial hemorrhages. Mol Plant Microbe Interact, 2001 May, 14(5), 639 - 52 Polymorphism of the polyketide synthase gene phID in biocontrol fluorescent pseudomonads producing 2,4-diacetylphloroglucinol and comparison of PhID with plant polyketide synthases; Ramette A et al.; Many biocontrol fluorescent pseudomonads can protect plants from soilborne fungal pathogens through production of the antifungal secondary metabolite 2,4-diacetylphloroglucinol (Phl) . One of the phl biosynthetic genes, phlD, encodes a polyketide synthase similar to plant chalcone synthases . Here, restriction analysis of phlD from 39 Phl+ biocontrol fluorescent pseudomonads yielded seven different banding patterns . The gene was sequenced in seven strains, representing the different restriction patterns . Cluster analysis of phlD restriction data or phlD sequences indicated that phlD polymorphism was high, and two main clusters were obtained when predicted PhlD sequences were compared . When the seven PhlD sequences were studied with those of other procaryotic polyketide synthases (gram-positive bacteria) and plant chalcone synthases, however, Phl+ pseudomonads, gram-positive bacteria, and plants clustered separately . Yet, sequence analysis of active site regions for PhlD and plant chalcone synthases revealed that PhlD can be considered a member of the chalcone synthase family, which may be interpreted as convergent evolution of key enzymes involved in secondary metabolism . For the 39 Phl+ pseudomonads, a relationship was found among phlD restriction patterns, phylogenetic groups defined by 16S rDNA restriction analysis (confirmed by 16S rDNA sequencing), and production levels of Phl in vitro. Perit Dial Int, 2001 Mar-Apr, 21(2), 154 - 7 Diagnostic value of effluent endotoxin level in gram-negative peritonitis in CAPD patients; Muhammed KO et al.; OBJECTIVE: To evaluate the diagnostic usefulness of effluent endotoxin by Limulus amoebocyte lysate (LAL) assay in gram-negative peritonitis patients on continuous ambulatory peritoneal dialysis (CAPD) therapy . DESIGN: Prospective study with patients serving as their own controls . Standard microbiologic work up and endotoxin analysis of effluents (night dwell) were done during the pre- and posttreatment phases . SETTING: Specimens from three teaching hospitals were processed and tested at a common center . Patients were left for treatment at their respective centers without intervention . PATIENTS: 32 clinical peritonitis and 40 infection-free CAPD patients were studied . RESULTS: 75% (n = 24) of cultures were positive: 41.6% (n = 10) gram-negative and 58.4% (n = 14) gram-positive bacteria . Effluents of pre- and posttreated gram-negative cultures had endotoxin levels of 1.53 +/- 0.169 and 0.214 +/- 0.085 endotoxin units (EU)/mL, respectively (p < 0.0001); pre- and posttreated gram-positive levels of 0.102 +/- 0.06 and 0.122 +/- 0.052 EU/mL, respectively (p > 0.05); pre- and posttreated culture-negative peritonitis levels of 0.110 +/- 6.025 and 0.087 +/- 0.031 EU/mL, respectively (p > 0.05); peritonitis-free effluents contained 0.117 +/- 0.079 EU/mL . The diagnostic specificity and the sensitivity of LAL assay were 100% and 98.2% respectively . CONCLUSION: Where initial microbiological work-up cannot demonstrate a pathogen, effluent endotoxin determined by quantitative LAL assay is a useful marker for diagnosis and management, within safe time limits, of gram-negative peritonitis in CAPD patients. Clin Diagn Lab Immunol, 2001 May, 8(3), 515 - 21 Peptidoglycan and lipoteichoic acid modify monocyte phenotype in human whole blood; Jorgensen PF et al.; We examined the influence of the gram-positive cell wall products peptidoglycan (PepG) and lipoteichoic acid (LTA), compared to lipopolysaccharide (LPS), on the monocyte expression of receptors involved in antigen presentation (HLA-DR, B7.1, and B7.2), cell adhesion (intercellular adhesion molecule-1 {ICAM-1} and lymphocyte function associated antigen-3 {LFA-3}), phagocytosis (Fc gamma RI), and cell activation (CD14) . We also evaluated possible influences of the immunosuppressive drugs cyclosporine A, tacrolimus, and sirolimus on the expression of these receptors . Pretreatment of whole blood for 4 h with the immunosuppressive drugs did not influence the expression of the surface receptors in normal or stimulated blood . Stimulation with both PepG and LTA caused significant up-regulation of the surface expression of ICAM-1 and HLA-DR on whole blood monocytes, similar to that obtained with LPS, whereas B7.1, B7.2, LFA-3, and Fc gamma RI were not modulated . PepG and LTA also caused increased expression of CD14, whereas LPS down-regulated this molecule . In contrast, we did not detect any significant influence of any of the bacterial products on the plasma concentration of soluble CD14 . We hypothesized that the increased expression of surface CD14 in blood stimulated with PepG would prime for cellular activation by LPS . Indeed, we show that PepG and the partial PepG structure muramyl dipeptide acted in synergy with LPS to cause the release of tumor necrosis factor-alpha . The results suggest that PepG and LPS provoke partly different responses on monocyte phenotype and that CD14 may play different roles in the innate response to gram-positive and gram-negative bacteria. J Bacteriol, 2001 May, 183(10), 3184 - 92 Role of acid metabolism in Streptomyces coelicolor morphological differentiation and antibiotic biosynthesis; Viollier PH et al.; Studies of citrate synthase (CitA) were carried out to investigate its role in morphological development and biosynthesis of antibiotics in Streptomyces coelicolor . Purification of CitA, the major vegetative enzyme activity, allowed characterization of its kinetic properties . The apparent K(m) values of CitA for acetyl coenzyme A (acetyl-CoA) (32 microM) and oxaloacetate (17 microM) were similar to those of citrate synthases from other gram-positive bacteria and eukaryotes . CitA was not strongly inhibited by various allosteric feedback inhibitors (NAD(+), NADH, ATP, ADP, isocitrate, or alpha-ketoglutarate) . The corresponding gene (citA) was cloned and sequenced, allowing construction of a citA mutant (BZ2) . BZ2 was a glutamate auxotroph, indicating that citA encoded the major citrate synthase allowing flow of acetyl-CoA into the tricarboxylic acid (TCA) cycle . Interruption of aerobic TCA cycle-based metabolism resulted in acidification of the medium and defects in morphological differentiation and antibiotic biosynthesis . These developmental defects of the citA mutant were in part due to a glucose-dependent medium acidification that was also exhibited by some other bald mutants . Unlike other acidogenic bald strains, citA and bldJ mutants were able to produce aerial mycelia and pigments when the medium was buffered sufficiently to maintain neutrality . Extracellular complementation studies suggested that citA defines a new stage of the Streptomyces developmental cascade. Am J Kidney Dis . 2001 May;37(5):E38. Antineutrophil cytoplasmic autoantibody specific for proteinase 3 in a patient with shunt nephritis induced by Gemella morbillorum; Nagashima T et al.; A 17-year-old girl had been placed with ventriculoperitoneal, then ventriculoatrial shunts for congenital hydrocephalus since birth . The patient originally was diagnosed as having a lupus-like disease, but later turned out to have shunt nephritis, presenting with fever, proteinuria, pancytopenia, and hypocomplementemia . Antineutrophil cytoplasmic autoantibody specific for proteinase 3 (PR3-ANCA) was detected in her serum . The patient received oral prednisolone and repeated methylprednisolone pulses, with essentially no beneficial effects . A gram-positive coccus, Gemella morbillorum, was recovered from her blood as well as cerebrospinal fluid, and the culture of the shunt catheter established the diagnosis of shunt nephritis . Removal of the shunt catheter improved symptoms dramatically and decreased PR3-ANCA in serum to an undetectable level . Because steroids had no effects and the control of bacterial infection lowered PR3-ANCA levels, the antibody would have been induced by continuous infection with G morbillorum. Biochem Biophys Res Commun, 2001 Apr 27, 283(1), 195 - 204 Isolation and characterization of the genes encoding a novel oxygenase component of angular dioxygenase from the gram-positive dibenzofuran-degrader Terrabacter sp . strain DBF63; Kasuga K et al.; A gram-positive bacterium Terrabacter sp . strain DBF63 is able to degrade dibenzofuran (DF) via initial dioxygenation by a novel angular dioxygenase . The dbfA1 and dbfA2 genes, which encode the large and small subunits of the dibenzofuran 4,4a-dioxygenase (DFDO), respectively, were isolated by a polymerase chain reaction-based method . DbfA1 and DbfA2 showed moderate homology to the large and small subunits of other ring-hydroxylating dioxygenases (less than 40%), respectively, and some motifs such as the Fe(II) binding site and the {2Fe-2S} cluster ligands were conserved in DbfA1 . DFDO activity was confirmed in Escherichia coli cells containing the cloned dbfA1 and dbfA2 genes with the complementation of nonspecific ferredoxin and ferredoxin reductase component of E . coli . Under this condition, these cells exhibited angular dioxygenation of DF and dibenzo-p-dioxin, and monooxygenation of fluorene, but not angular dioxygenation of carbazole, xanthene, and phenoxathiin . Phylogenetic analysis revealed that DbfA1 formed a branch with recently reported large subunits of polycyclic aromatic hydrocarbon (PAH) dioxygenase from gram-positive bacteria but did not cluster with that of other angular dioxygenases, i.e., DxnA1 from Sphingomonas sp . strain RW1 {Armengaud, J., Happe, B., and Timmis, K . N . J . Bacteriol . 180, 3954-3966, 1998} and CarAa from Pseudomonas sp . strain CA10 {Sato, S., Nam, J.-W., Kasuga, K., Nojiri, H., Yamane, H., and Omori, T . J . Bacteriol . 179, 4850-4858, 1997} . Vet Rec, 2000 Apr 29, 146(18), 515 - 8 Evaluation of bacteria isolated from infected eyes of captive, non-domestic animals; Williams DL et al.; Bacteria isolated from the eyes of captive species with suspected ocular infections at London Zoo were identified by standard methods . The sensitivity of the organisms to several topical antibiotics was determined by using sensitivity discs, and the minimum inhibitory concentrations of chloramphenicol and fusidic acid were determined . Correlations were evaluated between the results from the antibiotic discs and the minimum inhibitory concentrations and, where possible, between the clinical response to treatment and the results of bacteriological sensitivity tests . Unlike the isolates found in cats and dogs gram-positive cocci accounted for 54 per cent of isolates but almost half of the bacteria isolated were gram-negative organisms. Int J Syst Evol Microbiol, 2001 Mar, 51(Pt 2), 475 - 9 Aerococcus sanguicola sp . nov., isolated from a human clinical source; Lawson PA et al.; Phenotypic and phylogenetic studies were performed on an unknown, Gram-positive, catalase-negative coccus isolated from human blood . Comparative 16S rRNA gene sequencing demonstrated that the organism represents a new subline within the genus Aerococcus . The unknown bacterium was readily distinguished from the three currently recognized Aerococcus species, Aerococcus christensenii, Aerococcus urinae and Aerococcus viridans, by biochemical tests and electrophoretic analysis of whole-cell proteins . On the basis of phylogenetic and phenotypic evidence, it is proposed that this unknown bacterium from blood be classified as Aerococcus sanguicola sp . nov . The type strain of Aerococcus sanguicola is CCUG 43001T (= CIP 106533T). Microbiology, 2001 May, 147(Pt 5), 1197 - 212 Genomic analysis of the histidine kinase family in bacteria and archaea; Kim D et al.; Two-component signal transduction systems, consisting of histidine kinase (HK) sensors and DNA-binding response regulators, allow bacteria and archaea to respond to diverse environmental stimuli . HKs possess a conserved domain (H-box region) which contains the site of phosphorylation and an ATP-binding kinase domain . In this study, a genomic approach was taken to analyse the HK family in bacteria and archaea . Based on phylogenetic analysis, differences in the sequence and organization of the H-box and kinase domains, and the predicted secondary structure of the H-box region, five major HK types were identified . Of the 336 HKs analysed, 92% could be assigned to one of the five major HK types . The Type I HKs were found predominantly in bacteria while Type II HKs were not prevalent in bacteria but constituted the major type (13 of 15 HKs) in the archaeon Archaeoglobus fulgidus . Type III HKs were generally more prevalent in Gram-positive bacteria and were the major HK type (14 of 15 HKs) in the archaeon Methanobacterium thermoautotrophicum . Type IV HKs represented a minor type found in bacteria . The fifth HK type was composed of the chemosensor HKs, CheA . Several bacterial genomes contained all five HK types . In contrast, archaeal genomes either contained a specific HK type or lacked HKs altogether . These findings suggest that the different HK types originated in bacteria and that specific HK types were acquired in archaea by horizontal gene transfer. J Biol Chem, 2001 Jul 13, 276(28), 25680 - 6 Epub 2001 Apr 20. The role of toll-like receptors (TLRs) in bacteria-induced maturation of murine dendritic cells (DCS) . Peptidoglycan and lipoteichoic acid are inducers of DC maturation and require TLR2; Michelsen KS et al.; Toll-like receptors (TLRs) have been found to be key elements in pathogen recognition by the host immune system . Dendritic cells (DCs) are crucial for both innate immune responses and initiation of acquired immunity . Here we focus on the potential involvement of TLR ligand interaction in DC maturation . TLR2 knockout mice and mice carrying a TLR4 mutation (C3H/HeJ) were investigated for DC maturation induced by peptidoglycan (PGN), lipopolysaccharide (LPS), or lipoteichoic acids (LTAs) . All stimuli induced maturation of murine bone marrow-derived DCs in control mice . TLR2(-)/- mice lacked maturation upon stimulation with PGN, as assessed by expression of major histocompatibility complex class II, CD86, cytokine, and chemokine production, fluorescein isothiocyanate-dextran uptake, and mixed lymphocyte reactions, while being completely responsive to LPS . A similar lack of maturation was observed in C3H/HeJ mice upon stimulation with LPS . DC maturation induced by LTAs from two different types of bacteria was severely impaired in TLR2(-)/-, whereas C3H/HeJ mice responded to LTAs in a manner similar to wild-type mice . We demonstrate that DC maturation is induced by stimuli from Gram-positive microorganisms, such as PGN and LTA, with similar efficiency as by LPS . Finally, we provide evidence that TLR2 and TLR4 interaction with the appropriate ligand is essential for bacteria-induced maturation of DCs. Clin Chest Med, 2001 Mar, 22(1), 71 - 85 Respiratory infection in the chronically critically ill patient . Ventilator-associated pneumonia and tracheobronchitis; Ahmed QA et al.; The long-term ventilated patient is at high risk for developing nosocomial pneumonia or tracheobronchitis . In general, the frequency of infection increases with the duration of mechanical ventilation, but the risk appears to be greatest in the first week of intubation . Although these types of infection are common and may have morbidity and mortality impact, the daily risk is less in the long-term ventilated patient than in the acutely ill intubated patient . This reduced daily risk may reflect a "survivor effect," with less healthy patients dying early in the hospital stay and not surviving long enough to undergo tracheostomy and long-term ventilation . A number of factors predispose these patients to infection, including host defense impairment and exposure to large numbers of bacteria . This exposure can occur through the airway, and proper care of respiratory therapy devices is essential to minimize the risk for infection . Most infections of the lower respiratory tract are preceded by airway colonization with EGN bacteria and, with improvement in host defenses and nutrition, infection in the face of colonization is less likely . In some patients, colonization can be eliminated . When the long-term ventilated patient does develop infection, it generally involves highly resistant gram-negative or gram-positive organisms and therapy should be prompt and appropriate . Not all such patients respond to systemic antibiotics, and the use of adjunctive aerosol therapy may have benefit for those with either tracheobronchitis or pneumonia, especially if highly resistant pathogens are present. Rheumatology (Oxford), 2001 Apr, 40(4), 438 - 46 Peptidoglycan from sterile human spleen induces T-cell proliferation and inflammatory mediators in rheumatoid arthritis patients and healthy subjects; Schrijver IA et al.; OBJECTIVES: Peptidoglycan (PG), a component of Gram-positive bacteria, may be involved in rheumatoid arthritis (RA) because of its ability to induce production of proinflammatory cytokines, to induce arthritis in rodents, and its presence in antigen-presenting cells in RA joints . METHODS: In the present study, physiologically relevant PG was able to induce T-cell proliferation in peripheral blood and synovial fluid samples of RA patients, but the magnitude of the response did not differ from that of cells from healthy subjects . In addition, production of cytokines associated with RA (interleukins (IL)-1beta, IL-6, IL-8, IL-10, IL-12 and tumour necrosis factor alpha) and of the matrix metalloproteinase, gelatinase B (MMP-9), was induced in blood and synovial fluid cultures of RA patients . CONCLUSION: The fact that PG, which can be found in synovial tissues of RA patients is able to induce the production of inflammatory mediators supports the hypothesis that PG plays a role in the pathogenesis of RA by influencing the inflammatory microenvironment of the joint. Intern Med, 2001 Mar, 40(3), 246 - 9 Pulmonary nocardiosis associated with idiopathic thrombocytopenic purpura; Ando T et al.; A 69-year-old woman with idiopathic thrombocytopenic purpura, who was regularly followed and treated with prednisolone and danazol, was admitted to our hospital because of shortness of breath . Chest roentgenogram showed a large amount of left-sided pleural effusion . Gram-positive branching rods, subsequently identified as Nocardia farcinica, were isolated from the fluid . Antibiotic treatment together with pleural drainage with an intercostal catheter resulted in complete remission of pyothorax . Pulmonary nocardiosis is a rare disease, but recognition of the disease in immunocompromised patients and the prompt initiation of appropriate treatments based on isolation of the pathogen can lead to a successful outcome. Chemotherapy, 2001 May-Jun, 47(3), 226 - 31 Treatment of febrile neutropenia with cefepime monotherapy; Jandula BM et al.; BACKGROUND AND OBJECTIVE: The empirical administration of a broad-spectrum beta-lactam antibiotic, either as monotherapy or in combination with an aminoglycoside, is an essential component of the initial management of patients with fever and severe neutropenia . Multiple antibiotics have been tested for this indication . Cefepime is a fourth-generation cephalosporin with in vitro activity against most gram-negative and many gram-positive bacteria . We have studied the use of this agent as monotherapy in this indication . METHODS: One hundred and twenty-six episodes of febrile neutropenia in 98 adults with hematological malignancies were treated with cefepime monotherapy . Cefepime was given at a dose of 2 g every 8 h i.v . Most episodes (49%) were fever of unexplained origin, while a microbiologically documented and clinically documented infection occurred in 25% episodes each . Seventy-six (61%) episodes occurred after conventional chemotherapy, while 51 (41%) after a hematopoietic stem cell transplantation . Results: Twelve episodes (10%) were not evaluable for response . Among the 114 evaluable episodes, 69 (55% of the initial sample and 61% of those evaluable) responded to cefepime monotherapy, while therapy failed in 45 cases (36% of the initial sample and 39% of those evaluable), including 14 cases who developed breakthrough bacteremia during therapy . There were no deaths due to bacterial infection . At the end of all antibiotic therapy (final outcome) 69 episodes were cured only with monotherapy, 47 were cured with modification of therapy and 10 patients died from an unrelated cause . The only variable that appeared to correlate with response to therapy was the duration of neutropenia, which was longer among patients who failed or developed breakthrough bacteremia than among those who responded to monotherapy . INTERPRETATION AND CONCLUSIONS: Initial empirical antibiotic therapy with cefepime as a single agent in patients with febrile neutropenia and a hematological malignancy is effective, but patients with prolonged neutropenia appear to be at higher risk for failure . However, with appropriate therapeutic changes the risk of dying from a bacterial infection is very low . J Clin Pharmacol, 2001 Apr, 41(4), 404 - 14 Multiple-dose pharmacokinetics and safety of two regimens of quinupristin/dalfopristin (Synercid) in healthy volunteers; Chevalier P et al.; Quinupristin/dalfopristin (Q/D) is a novel streptogramin antibiotic for the treatment of severe gram-positive infections . The purpose of this open, nonrandomized, parallel-group, phase I trial was to evaluate Q/D pharmacokinetics after single and repeated doses under the two different dosing regimens corresponding to the effective doses and to evaluate tolerability . Two groups of 10 healthy volunteers received multiple 1-hour intravenous infusions of 7.5 mg/kg Q/D either every 8 or 12 hours for 4 or 5 days, respectively . Plasma concentrations of Q, D, and metabolites were determined using high-performance liquid chromatography and selective microbiological assays . The two regimens q8h and q12h lead to the same disposition profile after single and repeated administration . Single-dose data confirmed the high plasma clearances of Q and D (about 0.90 l/h/kg) obtained previously . Unchanged drugs were the main components in plasma, with each of the three metabolites representing about 20% (in terms of the AUC ratio) of the parent drugs . Comparable steady-state concentrations were reached from day 2 of both regimens . A similar moderate increase in Cmax and AUC (about 20%) of parent drugs was observed between the first and last day of treatment . This phenomenon, which was also observed for the metabolites, was not expected considering the short terminal disposition half-lives of the parent drugs and trough plasma concentrations of all components mostly below the limits of quantitation at steady state, whatever the dosing regimen . The clearances of parent drugs at steady state were about 20% lower as compared with that observed following the first drug administration (statistically significant difference) . No trend suggesting a treatment effect on any laboratory parameter, vital signs, or electrocardiographic parameters was identified . However, 80% of subjects reported venous adverse events probably related to treatment. Pediatr Infect Dis J, 2001 Mar, 20(3), 343 - 9 Empiric use of cefepime in the treatment of lower respiratory tract infections in children; Bradley JS et al.; BACKGROUND: These studies were designed to assess the efficacy and safety of cefepime, a fourth generation cephalosporin, for the treatment of serious infections, including lower respiratory tract infections (LRTI) in children . METHODS: Four clinical trials of cefepime for the treatment of serious bacterial infections enrolled 259 children with LRTI . In 3 trials cefepime was compared with ceftazidime (n = 166), cefotaxime (n = 16) or cefuroxime (n = 12) . One trial was noncomparative (n = 65) . RESULTS: Treatment with cefepime 50 mg/kg/ dose administered every 8 to 12 h produced a satisfactory clinical response (clinical signs of infection resolved or improved with no evidence of recurrent infection at posttreatment follow-up) in 88 to 100% of patients, comparable with comparator therapy . In children from whom a causative pathogen was identified, bacteriologic eradication was comparable between cefepime and comparator therapy . Cefepime was as safe and well-tolerated as comparator therapy . Few treatment-related clinical or laboratory adverse events were noted and were equivalent to comparator in all studies . CONCLUSION: Cefepime is as effective, safe and well-tolerated for the empiric treatment of children with LRTI as comparator agents but offers the advantage of an enhanced spectrum of activity for Gram-positive and Gram-negative pathogens compared with second or third generation cephalosporins. Crit Care, 2001, 5(2), 53 - 5 Epub 2001 Feb 26.