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| Microb Drug Resist, 1996 Summer, 2(2), 225 - 9 Peptidoglycan composition of vancomycin-resistant Enterococcus faecium; de Jonge BL et al.; Muropeptide composition of peptidoglycan isolated from isogenic vancomycin-resistant and sensitive Enterococcus faecium strains was analyzed by reverse-phase high-performance liquid chromatography combined with amino acid and fast atom bombardment mass spectrometric analyses . Peptidoglycan of the sensitive and resistant strains was the same and was composed of tri- and tetrapeptides stem peptide subunits with or without aspartate or asparagine substitutions on the epsilon-amino group of the lysine residue . Thus, the synthesis of lactate-terminating peptidoglycan precursors in vancomycin-resistant E . faecium did not affect the chemical composition of peptidoglycan. Microb Drug Resist, 1996 Summer, 2(2), 219 - 23 Genetics of glycopeptide resistance in enterococci; Evers S et al.; Glycopeptide resistance in enterococci is phenotypically and genotypically heterogeneous . The genes responsible for inducible resistance to high levels of vancomycin and teicoplanin (VanA phenotype) are carried by the 10,851-bp Tn1546 transposon . Transposition of Tn1546 into self-transferable plasmids and subsequent transfer by conjugation appears to be responsible for the dissemination of this type of resistance . Nine polypeptides are encoded by Tn1546 that belong to five functional groups: transposition functions (ORF1 and ORF2), regulation of resistance gene expression (VanR and VanS), synthesis of depsipeptide D-Ala-D-lactate (VanH and VanA), hydrolysis of D-Ala-D-Ala-containing peptidoglycan precursors (VanX and VanY), and low-level teicoplanin resistance (VanZ) . VanB-type resistance (various levels of resistance to vancomycin and susceptibility to teicoplanin) is also due to production of D-Ala-D-Lac . The VanB ligase of VanB-type strains is structurally and functionally similar to VanA . The vanB gene was found on composite transposon Tn1547, which, in turn, was part of larger conjugative chromosomally located elements (90 to 250 kb) . In contrast to acquired VanA- and VanB-type resistance, VanC-type resistance (low level of resistance to vancomycin and susceptibility to teicoplanin) is an intrinsic property of motile enterococci . Resistance in these species is due to synthesis of dipeptide D-Ala-D-Ser by VanC ligases leading to production of cell wall precursors with reduced vancomycin affinity. Diagn Microbiol Infect Dis, 1996 Jul, 25(3), 127 - 31 Comparative in vitro activity of quinupristin/dalfopristin against multidrug resistant Enterococcus faecium; Bonilla HF et al.; The in vitro susceptibilities of 82 strains of vancomycin resistant Enterococcus faecium (VREF), (49 vanA and 33 vanB) from over 13 hospitals in Europe and United States were studied . The MIC for several antibiotics showed high levels of resistance to vancomycin, ampicillin, gentamicin, and imipenem . All VREF strains were highly susceptible to quinupristin/dalfopristin with a MIC 90% of 0.5 microgram/ml for both vanA and vanB phenotypes . Time-kill and synergy studies of VREF for quinupristin/dalfopristin alone and quinupristin/dalfopristin in combination with several antibiotics (ampicillin, gentamicin, ciprofloxacin, rifampin and novobiocin) did not show bactericidal activity . In induction experiments using SF6550, (VREF, a vanA strain), quinupristin/dalforpristin showed a delay in the expression of vancomycin resistance by 2.5 hours . The results of this study show quinupristin/dalfopristin to have excellent in vitro activity versus multiple resistant E . faecium. Electrophoresis, 1996 Jul, 17(7), 1234 - 41 Purification of glycopeptide antibiotics by isoelectric focusing in multicompartment electrolyzers with immobiline membranes; Bossi A et al.; The purification of small glycopeptides (a Hepta-Tyr of the teicoplanin family, exhibiting broad activity against highly glycopeptide-resistant enterococci) by isoelectric focusing in multicompartment electrolyzers with buffering, isoelectric membranes, is described . The main obstacle to such a preparative technique, in common with all focusing methodologies, is the poor solubility of the analyte at the pI value with resultant precipitation and coprecipitation of all impurities with the main fraction . A good solubilizing power was obtained in hydro-organic solvents, particularly a mixture of 6 M urea and 20-25% trifluoroethanol . Best results, however, were obtained with mixtures of 8 M urea and zwitterionic detergents, notably the 3-{(3-cholamidopropyl)dimethylammonia}-1-propanesulfonate (CHAPS) family . A unique behavior of the peptide was found in concentration gradients of CHAPS: solubility increases up to 3.5% CHAPS, but the curve shows a maximum and then solubility decreases again at 5% CHAPS . In mixtures of 8 M urea and 3.5% CHAPS, sample loads of 500 up to 1000 mg Hepta-Tyr could be purified in a single run, with recoveries > 90% and purity in excess of 99% . The main glycopeptide fraction (pI 8.56) was collected into an isoelectric trap delimited by pI 8.46 and pI 8.65 membranes . Attempts at purifying the glycopeptide by most known reversed phase-high performance liquid chromatography (RP-HPLC) techniques failed completely. Pharmacotherapy, 1996 Jul-Aug, 16(4), 584 - 92 Treatment of vancomycin-resistant enterococci, with a focus on quinupristin-dalfopristin; Fuller RE et al.; Enterococci are the second most common cause of hospital-acquired infections, and drug resistance among these organisms is a growing problem . Vancomycin-resistant enterococci (VRE) now account for 7.9% of the nosocomial enterococcal infections . There is no standard therapy for VRE . Although some agents have shown in vitro activity alone or in combination, including ciprofloxacin, doxycycline, novobiocin, teicoplanin, chloramphenicol, and rifampin, treatment options are limited to combinations of drugs with marginal efficacy against the pathogens . Quinupristin-dalfopristin is a new investigational agent with activity against gram-positive cocci, including VRE. J Hosp Infect, 1996 Jul, 33(3), 191 - 200 Investigation of an outbreak of vancomycin-resistant Enterococcus faecium by random amplified polymorphic DNA (RAPD) assay; Issack MI et al.; In this study, 122 isolates of vancomycin-resistant Enterococcus faecium (VREF) obtained from 103 patients over a four-year period in a London teaching hospital, were typed by a random amplified polymorphic DNA method . All the isolates exhibited high-level resistance to vancomycin (MIC 128-1024 mg/L), and were resistant to teicoplanin (32-256 mg/L) . Nine RAPD types were distinguished by using a single primer . Clustering of certain types in time and space was noted . These results suggest that although several different strains of VREF were involved in this outbreak, cross-infection with individual types occurred on some wards . RAPD is a useful technique for the investigation of the epidemiology of VREF. Am J Health Syst Pharm, 1996 Jul 1, 53(13), 1570 - 5 Limiting vancomycin use to combat vancomycin-resistant Enterococcus faecium; Belliveau PP et al.; The implementation, monitoring, and impact of a program to restrict vancomycin use are described . A vancomycin restriction program was implemented in February 1995 at an acute care teaching hospital after guidelines for vancomycin use were established by a multidisciplinary group . Pharmacists reviewed each vancomycin order, suggested alternative treatments when vancomycin use did not comply with the guidelines, and set duration limits for all orders . Orders requiring greater clinical experience for review were referred to a pharmacist or a physician in the division of infectious diseases . The program was monitored by an infectious diseases pharmacist . Data collected after the program was established showed that the volume of vancomycin use decreased substantially . Problems in enforcing the restriction program included administration of vancomycin for surgical prophylaxis before the order reached the pharmacy, continuing use of vancomycin for initial empirical treatment of febrile neutropenic and immunocompromised patients, inadequate tracking of the evaluations, and deficiencies in the evaluations related to a need for continuing education of the pharmacists about the program . Use of vancomycin decreased after a pharmacy-enforced restriction program was implemented. Antimicrob Agents Chemother, 1996 Jul, 40(7), 1745 - 7 In vitro activities in new oxazolidinone antimicrobial agents against enterococci; Eliopoulos GM et al.; The comparative in vitro activities of two new oxazolidinone antimicrobial agents, U-100592 and U-100766, against 180 isolates of enterococci representing several resistance profiles were examined by using an agar dilution technique . The two oxazolidinones inhibited all isolates, including strains resistant to vancomycin, ampicillin, and minocycline, at concentrations between 1 and 4 micrograms/ml. Antimicrob Agents Chemother, 1996 Jul, 40(7), 1645 - 8 Induction signals for vancomycin resistance encoded by the vanA gene cluster in Enterococcus faecium; Lai MH et al.; The induction of vancomycin resistance in enterococci containing the vanA gene cluster is thought to be controlled by a two-component sensor-response regulator system encoded by vanR and vanS . Eight inducing compounds were identified by screening a panel of more than 6,800 antibiotics and synthetic compounds including the three tested glycopeptides (vancomycin, avoparcin, and ristocetin), two other cell wall biosynthesis inhibitors (moenomycin and bacitracin), two cyclic peptide antibiotics (antibiotic AO341 beta and polymyxin B), and a macrocyclic lactone antibiotic (moxidectin) . Induction activity by structurally unrelated antibiotics suggests that the induction signal is not a structural feature of vancomycin. Gene, 1996 Jun 26, 172(2), 239 - 43 The Drosophila melanogaster gene vha14 encoding a 14-kDa F-subunit of the vacuolar ATPase; Guo Y et al.; A Drosophila melanogaster (Dm) cDNA (vha14) encoding the 14-kDa F-subunit of the vacuolar H(+)-ATPase (V-ATPase) has been cloned via homology with the corresponding Manduca sexta (Ms) gene . Its deduced translation product is a 124-amino-acid polypeptide sharing 90% identity with the Ms polypeptide and 50% identity with an analogous polypeptide of Saccharomyces cerevisiae, and a more distant similarity to a subunit of the Na(+)-transporting ATPase of Enterococcus hirae . Homology was also found with expressed sequence tags from man, Arabidopsis thaliana, Caenorhabditis elegans and C . briggsiae, Oryza sativa and Plasmodium falciparum, indicating that the subunit is phylogenetically conserved . The Dm gene (vha14) is present as a single copy at cytological position 52B on the second chromosome, and gives rise to an mRNA species of 0.65 kb . Expression of the latter shows relatively little variation during development, or between adult head, thorax and abdomen, suggesting that the F-subunit is a relatively ubiquitous component of the V-ATPase. Ann Pharmacother, 1996 Jun, 30(6), 680 - 2 Vancomycin resistance: when failure becomes an opportunity for leadership; Edmiston CE Jr; OBJECTIVE: To discuss the emergence of the enterococci as significant nosocomial pathogens and reports of glycopeptide resistance as demonstrating the failure of healthcare professionals to limit the clinical impact of these organisms . BACKGROUND: The enterococci have long occupied a peculiar position in medical and surgical patients . A component of the normal gastrointestinal tract, these organisms exhibit little overt pathogenicity in healthy hosts, but are frequently recovered in patients with severe debilitative or immunosuppresive disorders . While the enterococci have always demonstrated intrinsic resistance to a broad range of antiinfective agents, recent findings of moderate to high-level glycopeptide resistance potentially threaten the limited therapeutic options for methicillin-resistant gram-positive cocci . FINDINGS: The emergence and dissemination of vancomycin-resistant enterococci are signs of much greater problems, which include incomplete success of formulary controls, unreliable detection and identification of resistant microorganisms within the hospital environment, and poor fundamental infection control practices by all healthcare professionals . CONCLUSIONS: The Hospital Infection Control Practices . Advisory Committee Recommendations for the Prevention and Spread of Vancomycin Resistance are an important step in resolving these issues through the elements of collegiality and shared leadership. J Antibiot (Tokyo), 1996 Jun, 49(6), 575 - 81 Reductive alkylation of glycopeptide antibiotics: synthesis and antibacterial activity; Cooper RD et al.; Reductive alkylation of the A82846 family of glycopeptide antibiotics has the potential of producing seven products . N-Alkylation of the disaccharide amino function can be accomplished selectively, and offers the greatest increase in antibacterial activity . Products resulting from N-alkylation of LY264826 (A82846B) provide the most potent derivatives as compared to other members of this class of antibiotics . Two of these derivatives, LY307599 and LY333328 are approximately 500 times more active than vancomycin against vancomycin-resistant enterococci. Lett Appl Microbiol, 1996 Jun, 22(6), 417 - 9 Purification and N-terminal amino acid sequence of Enterocin CRL 35, a 'pediocin-like' bacteriocin produced by Enterococcus faecium CRL 35; Farias ME et al.; Enterocin CRL 35, a bacteriocin produced by Enterococcus faecium CRL 35 that inhibits food-borne pathogens, was purified by precipitation with (NH4)2SO4, gel filtration, ion exchange and reverse phase chromatography . The partial N-terminal amino acid sequence indicated a strong homology with other 'pediocin-like bacteriocins' previously described. Planta Med, 1996 Jun, 62(3), 275 - 7 Comparison of antimicrobial properties of monoterpenes and their carbonylated products; Naigre R et al.; Some monoterpenes and their carbonylated products were evaluated for their antibacterial and antifungal properties . The carbonylation of tested monoterpenes was shown to increase the bacteriostatic and fungistatic activities specifically by the contact method . Concerning the killing effects, only (1R,2S,5R)-isopulegol, its carbonylated products, and (R)-carvone showed significant bactericidal activities, particularly against Enterococcus faecium and Escherichia coli above a concentration of 10 microliters/ml . A fungicidal efficiency of (1R,2S,5R)-isopulegol and (R)-carvone against Aspergillus niger was also noted . It seems that the presence of an oxygenated function in the framework increases the antimicrobial properties . However, monoterpenes were more active using a micro-atmosphere method. Diagn Microbiol Infect Dis, 1996 May, 25(1), 15 - 20 Selection of Enterococcus faecium strains with stable and unstable resistance to the streptogramin RP 59500 using stepwise in vitro exposure; Millichap J et al.; Therapy of vancomycin-resistant enterococcal infections is an increasing problem for many large medical centers . One promising agent for use against Enterococcus faecium is RP 59500 (Quinupristin/Dalfopristin) . To assess the potential for emergence of resistant strains during clinical trials with this new compound, we collected and tested 11 vancomycin-resistant and three vancomycin-susceptible E . faecium strains . The strains were exposed to doubling dilutions of RP 59500, beginning at drug concentrations ranging from 0.25 to 16 micrograms/ml agar . A saturated swab with approximately 3 x 10(7) organisms/ml was spread as a lawn on agar containing RP 59500 and incubated at 35 degrees C for 48 h . Growth on the highest drug-containing plate was used to prepare the inoculum for the next series of resistance-selection experiments . After the final passage, the range of the highest RP 59500 plate concentration with growth was 32-512 micrograms/ml (initial resistance frequency ranging from 1 x 10(-6) to > 1 x 10(-4) . After the selection of resistant strains, the organisms were passed twice weekly on antimicrobial agent-free media to determine resistance stability in the absence of drug . Resistance in strains with an RP 59500 MIC of > or = 16 micrograms/ml was stable after repeated passage for 4 weeks . These results indicate that stable resistance to RP 59500 can be selected in E . faecium when the organism is exposed to increasing drug concentrations only slightly above the minimum inhibitory concentration (MIC) . This stable resistance is seen in strains exhibiting an MIC > or = 16 micrograms/ml, and unstable in those with resistance where the RP 59500 MIC is less than eight times the original drug MIC . Our observation suggests more than one mechanism of resistance is likely present when stable resistance to RP 59500 develops. Hepatogastroenterology, 1996 May-Jun, 43(9), 586 - 9 Bacteremia following postoperative choledochofiberscopy--a prospective study; Chen MF et al.; BACKGROUND/AIMS: The following investigation was undertaken in order to determine the frequency and clinical consequences of bacteremia after postoperative choledochofiberscopy . MATERIALS AND METHODS: A total of 100 patients were prospectively studied for the frequencies of bacteremia after postoperative choledochoscopy . RESULTS: Positive blood cultures were obtained in 15%; at 5-minutes period in seven patients, at 15-minutes in eight patients and at 30-minutes in two patients . There were two patients with positive cultures at 5 minutes and 10 minutes periods . All the bacteria species cultured were aerobes . Enterococcus, E-coli and Klebsilla were the most commonly cultured bacteria . The frequencies of occurrence of bacteremia seemed not be influenced by the existence of residual stones, session of the endoscopy and duration of the procedure . Six of the 15 bacteremic patients developed cholangitis within 24 hours of the procedure . They all recovered with antibiotic treatment . Patients with negative blood cultures were not found with cholangitic symptoms after the postoperative choledochoscopy . CONCLUSIONS: The results of our study indicated that fifteen percent of patients undergoing postoperative choledochofiberscopy are associated with bacteremia . We believe that with adequate aseptic preparation and meticulous, gentle manipulation, routine prophylactic antibiotics may not be necessary for postoperative choledochoscopy in selected conditions. Jpn J Antibiot, 1996 May, 49(5), 456 - 64 {Isolation rate of E . coli from surgical infections and their susceptibilities}; Shinagawa N et al.; Escherichia coli isolated from surgical infections during the period from July 1983 to June 1995 were investigated in a multicenter study involving 19 hospitals in Japan, and the following results were obtained . 1 . Although the isolation rate of E . coli was not high from postoperative infections, it was most frequently isolated from primary infections throughout the study period . E . coli, Klebsiella spp . and anaerobic bacteria were predominant from fresh infections . From the cases that had previous antibiotics treatment, Enterococcus spp . were the most predominant isolates followed by MRSA and Pseudomonas spp . in this order . 2 . Against E . coli, cefozopran, carumonam and aztreonam had the strongest activity, followed by cefmenoxime, imipenem, latamoxef, gentamicin and ofloxacin . Recently, we have noticed that antibiotic resistant E . coli strains particularly against cefazolin are increasing year by year. J Clin Microbiol, 1996 May, 34(5), 1096 - 9 Random amplified polymorphic DNA typing versus pulsed-field gel electrophoresis for epidemiological typing of vancomycin-resistant enterococci; Barbier N et al.; Sixty vancomycin-resistant vanA mutant Enterococcus faecium (VRE) isolates, collected during a 40-month period from 48 patients hospitalized in a French Cancer Referral Center, were typed by using random amplified polymorphic DNA (RAPD), and the results were compared with those previously obtained by typing with SmaI pulsed-field gel electrophoresis (PFGE), which is currently recognized as the "gold standard." The discriminating power of RAPD typing, with seven primers and 11 combinations of primers, was tested on 18 strains, and only the most discriminating combination was further tested on the whole collection . We compared the epidemiological usefulness of RAPD typing of 60 clinical VRE isolates with that of SmaI PFGE typing . With primers AP4 and ERIC1R, RAPD generated 30 patterns versus the 36 patterns generated by SmaI PFGE . However, this did not hamper the epidemiologically correct clustering of 15 related strains and the detection of multiple colonization in nine patients . We conclude that this simple RAPD technique is well suited to the epidemiological typing of VRE and the monitoring of its nosocomial spread. Antimicrob Agents Chemother, 1996 May, 40(5), 1263 - 5 Plasmid-borne high-level resistance to gentamicin in Enterococcus hirae, Enterococcus avium, and Enterococcus raffinosus; Straut M et al.; Enterococcus hirae, E . avium, and E . raffinosus isolated in Romania, Tunisia, and Portugal harbored plasmids pICC8, pIP1700, and pIP1701, respectively, encoding resistance to high levels of gentamicin (Gmr) . The Gmr marker was carried on pIP1700 by a Tn4001-like element and on pICC8 and pIP1701 by Tn4001-truncated structures . pICC8 carried, in addition to Gmr, chloramphenicol, erythromycin, and tetracycline-minocycline (TetM) resistance determinants . The gene tetM of pICC8 was carried on a Tn916-like element. Arch Microbiol, 1996 May, 165(5), 297 - 305 The Bradyrhizobium japonicum fixGHIS genes are required for the formation of the high-affinity cbb3-type cytochrome oxidase; Preisig O et al.; We report structural and functional analyses of the Bradyrhizobium japonicum fixGHIS genes, which map immediately downstream of the fixNOQP operon for the symbiotically essential cbb3-type heme-copper oxidase complex . Expression of fixGHIS, like that of fixNOQP, is strongly induced in cells grown microaerobically or anaerobically . A fixGHI deletion led to the same prominent phenotypes as those known from a fixNOQP deletion: defective symbiotic nitrogen fixation (Fix-) and decreased cytochrome oxidase activity in cells grown under oxygen deprivation . Only traces, if any, of cytochrome cbb3 subunits were present in membranes isolated from the delta fixGHI strain, as revealed by Western blot analysis with subunit-specific antibodies . This effect was not due to lack of fixNOQP transcription . The results suggested a critical involvement of the fixGHIS gene products in the assembly and/or stability of the cbb3-type heme-copper oxidase . On the basis of sequence similarities between the FixI protein and a Cu-transporting P-type ATPase (CopA) of Enterococcus hirae, and between FixG and a membrane-bound oxidoreductase (RdxA) of Rhodobacter sphaeroides, we postulate that a membrane-bound FixGHIS complex might play a role in uptake and metabolism of copper required for the cbb3-type heme-copper oxidase. Postgrad Med, 1996 May, 99(5), 60 - 5, 69-71 Vancomycin-resistant enterococci . The 'superbug' scourge that's coming your way; Hagman HM et al.; Strains of vancomycin-resistant enterococci (VRE) have emerged and spread widely throughout the United States during the last few years . Multiply-resistant strains of Enterococcus faecium are especially troublesome because they are often resistant to all commercially available antimicrobial agents . At present, VRE infections occur most often in hospitalized patients with severe underlying disease who have undergone invasive procedures and received prolonged courses of broad-spectrum antimicrobial therapy . Because therapeutic options are limited, prevention of spread from patients with known cases to other vulnerable patients is essential. J Biol Chem, 1996 Apr 26, 271(17), 10042 - 7 The ntpJ gene in the Enterococcus hirae ntp operon encodes a component of KtrII potassium transport system functionally independent of vacuolar Na+-ATPase; Murata T et al.; The ntpJ gene, the tail end in the vacuolar type Na+-ATPase (ntp) operon of Enterococcus hirae, encodes a putative 49-kDa hydrophobic protein resembling K+ transporter protein in Saccharomyces cerevisiae (Takase, K., Kakinuma, S., Yamato, I., Konishi, K., Igarashi, K., and Kakinuma, Y . (1994) J . Biol . Chem . 269, 11037-11044) . Northern blotting experiment revealed that the ntpJ gene was transcribed as a cistron in the ntp operon . We constructed an Enterococcus strain in which the ntpJ gene was disrupted by cassette mutagenesis with erythromycin resistance gene . The growth of this mutant was normal at low pH . However, the mutant did not grow at high pH in K+-limited medium (less than 1 mM), while the wild type strain grew well; the internal K+ concentration of this mutant was as low as 7% of that of the wild type strain, suggesting that the K+ accumulation at high pH was inactivated by disruption of the ntpJ gene . Potassium uptake activity via the KtrII system, which had been proposed as the proton potential-independent, Na+-ATPase-coupled system working at high pH (Kakinuma, Y., and Harold, F . M . (1985) J . Biol . Chem . 260, 2086-2091), was missing in this mutant strain . However, this mutant retained as high activities of Na+-ATPase and Na+ pumping as the wild type strain . From these results, we conclude that the NtpJ is a membraneous component of the KtrII K+ uptake system but not a functional subunit of vacuolar Na+-ATPase complex; the interplay between the KtrII system and the Na+-ATPase was discussed. Biochemistry, 1996 Apr 16, 35(15), 4732 - 40 Kinetic comparison of the specificity of the vancomycin resistance VanSfor two response regulators, VanR and PhoB; Fisher SL et al.; Induction of vancomycin resistance in the Gram-positive Enterococci requires a two-componet regulatory system, VanS and VanR, for transcriptional activation of three genes (vanH, A, X) that encode enzymes for a cell wall biosynthetic pathway that produces an altered peptidoglycan intermediate with lower affinity for the antibiotic . The catalytic efficiency (kcat/KM) has been determined for phosphotransfer from the phosphohistidyl form of VanS to both its homologous partner VanR and the heterologous (Escherichia coli) response regulator Phob . The rate of formation of the phosphoaapartyl forms of VanR and PhoB were determined as well as the rate of appearance of inorganic phosphate . Using PhoB in excess of P-VanS, a pseudo-first-order rate constant (kxfer) of 0.2 min-1 for phosphotransfer and a KM for PhoB of 100 microM were readily determined . The corresponding kxfer of 96 min-1 for phosphotransfer from P-VanS to VanR required quench kinetics . A KM of 3 microM was estimated for VanR, leading to a 10(4)-fold preference in kxfer/KM for phosphotransfer to VanR compared to PhoB . No phosphotransfer was detachable to three other E . coli response regulators, OmpR, ArcB, or CreB, providing some sense of the selectivity against two-component regulatory system cross-talk . In the phosphotransfer from P-VanS to PhoB and VanR, there was evidence of competition between water, to give Pi, and the specific aspartyl beta-COO- moiety of either PhoB or VanR with about 25% of the initial flux generating inorganic phosphate . The kinetics of phosphotransfer from P-VanS to VanR were complicated by inhibition by free VanS but, the inhibition pattern could be modeled to yield at KD of 30 nM for VanR binding to free VanS, an affinity similar to that of the CheA-CheY pair in E . coli chemotaxis. MMWR Morb Mortal Wkly Rep, 1996 Apr 12, 45(14), 289 - 91 Assessment of testing for and completeness of reporting of vancomycin-resistant enterococci--Connecticut, 1994; Penicillin resistance and autolysis in enterococci; Department of Microbiology and Immunology, Temple University, School of Medicine, Philadelphia, Pennsylvania 19140, USAComparison of several cell wall-related properties of the ATCC 9790 strain and the R40 strain, a penicillin-resistant, PBP5 overproducing strain, and Rev14, a penicillin-hypersensitive, PBP5-deficient strain, is consistent with a role of the genetic element, psr, in the global regulation of lysozyme sensitivity, autolytic capacity, and wall-rhamnose-containing polysaccharide content . These parameters appear to be independently regulated by a system that involves psr in a currently unknown manner. Microb Drug Resist, 1996 Spring, 2(1), 95 - 8 Bacterial walls, peptidoglycan hydrolases, autolysins, and autolysis; Shockman GD et al.; Knowledge of the chemistry, ultrastructure, biosynthesis, assembly, and function of bacterial cell walls has expanded enormously since the opening of this field of research approximately 40 years ago, primarily by the early work of Milton Salton . It has become abundantly clear that, in most environments, walls are essential to the survival and growth of bacteria and in many ways are structurally and functionally unique . A common but not universal feature of bacterial walls is the presence of peptidoglycan (PG; murein, or in the case of certain Archae the analogous structure-pseudomurein) . PGs are considered to be primarily responsible for the protective and shape-maintaining properties of walls . They are a biologically unique class of macro-molecules in that they are not linear or even branched macromolecules . Instead they are two- or three-dimensional net like polymers that are linked together by three different chemical bonds (glycosidic, amide, and peptide) . In addition, they contain the D-isomers of some amino acids and therefore may possess DL, LD, and DD linkages . Furthermore, the exact chemical structure of a PG may vary depending on environmental factors, however, retaining the essential protective and shape maintaining properties of the wall . Thus, the overall architectural plan of the wall may be more important than the exact shape of the bricks used for the construct . Another somewhat unique feature of PGs (and walls) is their final assembly in situ on the outside of the cellular permeability barrier . A broad variety of bacteria have been shown to possess enzymes that can hydrolyze bonds in the wall PG . Hydrolysis of a sufficient number of bonds can result in the weakening of, or serious damage to, the protective properties of the PG . Frequently, a bacterial strain may possess more than one PG hydrolase activity . A commonly believed, but as yet unproven, hypothesis is that PG hydrolases play one or more roles in PG assembly and/or surface growth and cell division . At a minimum, such potentially suicidal activities must be exquisitely well regulated . Currently we know little concerning the regulation of these activities, or how they communicate with, and integrate with, chromosome replication, synthesis of cytoplasmic macromolecules, cell growth, and division, although such, probably two-way, communications must occur in growing and dividing cells . Recent data indicate that the psr element in Enterococcus hirae described by Fontana and collaborators as a genetic element that is involved in the regulation of the synthesis of PBP 5, also is involved in the regulation of several other surface properties . These properties include (1) autolysis rates of exponential phase . cells, (2) the retention of this property after cells enter the stationary phase, (3) lysozyme sensitivity, and (4) the ratio of rhamnose-containing wall polysaccharide to PG in the walls . Thus the psr element may be a part of a "global" regulation and communication system in E . hirae. Enferm Infecc Microbiol Clin, 1996 Apr, 14(4), 240 - 4 {Risk factors associated with the development of surgical wound infection in a general surgery service}; Dierssen T et al.; BACKGROUND . To evaluate incidence, etiology and risk factors of surgical wound infection (SWI) in a service of general surgery in a tertiary hospital . METHODS . Retrospective cohort study . The relative risk (RR) and its 95% confidence interval (CI) have been used as a measure of association between risk factors and SWI . Multiple logistic regression has been selected as multivariate analysis . RESULTS . Of 619 surgical patients, 60 (9.7%) developed SWI . The most frequently isolated microorganism was Enterococcus (26%), but a higher prevalence of gram negative was also found . On admission, the factors associated with SWI were: diabetes mellitus (RR = 2.5, CI95% = {1.0-6.3}), age older than 65 years (RR = 2.66, CI95% = {0.8-9.0}) and contaminated and dirty surgery (linear trends chi square, p = 0.044); among the amendable medical care factors, the duration of the surgery is the unique to be pointed out with an increment of 5 /1000 per minute (p = 0.011) . The admission an emergency unit presented a non significant adjusted RR of SWI near to 3 (CI95% = {0.9-9.6}) . CONCLUSIONS . SWI is related most importantly to risk factors at admission not amendable by the physician . Our results showed that the only factor susceptible to be changed is the duration of the surgical intervention. Antimicrob Agents Chemother, 1996 Apr, 40(4), 886 - 90 Intracellular activities of RP 59500 (quinupristin-dalfopristin) and sparfloxacin against Enterococcus faecium; Herrera-Insua I et al.; RP 59500, a combination of the streptogramins quinupristin and dalfopristin, and sparfloxacin are new antibiotics with good in vitro activities against Enterococcus faecium, which is an increasingly important nosocomial pathogen with resistance to multiple antimicrobials . Since fluoroquinolones and related macrolides have displayed high intracellular concentrations inside host cells, we evaluated the intracellular activities of these agents inside neutrophils against three strains each of vancomycin-susceptible E . faecium (VSEF) and vancomycin-resistant E . faecium (VREF) . At concentrations equal to four times the MIC, RP 59500 and sparfloxacin decreased the number of intracellular VSEF organisms, while both antibiotics were at best bacteriostatic against intracellular VREF strains . At concentrations equal to one-fourth of the MIC, both antibiotics were bacteriostatic against intracellular VSEF strains but were ineffective in inhibiting the growth of VREF strains . Despite their anticipated markedly higher intracellular human neutrophil (PMN) concentrations, RP 59500 and sparfloxacin activities in medium alone were equal to or greater than those inside PMNs against almost all strains . We conclude that the intracellular PMN concentrations of these antibiotics may not be directly related to their intracellular activities in our assay . The reason for the differences in their activities against VSEF versus VREF remains undefined. Clin Infect Dis, 1996 Apr, 22(4), 663 - 70 Differences in outcomes for patients with bacteremia due to vancomycin-resistant Enterococcus faecium or vancomycin-susceptible E . faecium; Linden PK et al.; To determine the differences in outcome in cases of enterococcal bacteremia due to vancomycin-resistant organisms, we compared consecutive patients on a liver transplant service who had clinically significant bacteremia due to vancomycin-resistant Enterococcus faecium (VREF) (n = 54) with a contemporaneous cohort of patients who had vancomycin-susceptible E . faecium (VSEF) bacteremia (n = 48) . VREF bacteremia occurred significantly later in the hospitalization than did VSEF bacteremia (43 days vs . 24 days, respectively; P < .01); in addition, VREF was more frequently the sole blood pathogen isolated (91% of patients) than was VSEF (56% of patients) (P = .0002) . Invasive interventions for intraabdominal and intrathoracic infection were required more often in the VREF cohort than in the VSEF cohort (34 of 45 patients vs . 20 of 41 patients, respectively; P = .01) . Vancomycin resistance more frequently resulted in recurrent bacteremia (22 of 54 patients infected with VREF vs . 7 of 48 patients infected with VSEF; P = .006), persistent isolation of Enterococcus species at the primary site (27 of 33 patients infected with VREF vs . 7 of 18 patients infected with VSEF; P = .005), and endovascular infection (4 patients infected with VREF vs . none infected with VSEF) . The decrement in patient survival, as measured from the last bacteremic episode, was greater in the VREF cohort (P = .02) . Vancomycin resistance, shock, and liver failure were independent risk factors for Enterococcus-associated mortality . Higher rates of refractory infection, serious morbidity, and attributable death occurred in the VREF cohort and were partially mediated by the lack of effective antimicrobial therapy. J Infect Dis, 1996 Apr, 173(4), 909 - 13 Effective treatment of multidrug-resistant enterococcal experimental endocarditis with combinations of cell wall-active agents; Brandt CM et al.; The efficacy of treatment with a combination of ampicillin, imipenem, and vancomycin was compared with that of two-drug combinations or monotherapy in a model of experimental endocarditis using a strain of Enterococcus faecium with high-level resistance to vancomycin and moderate intrinsic resistance to ampicillin and imipenem . In vitro time-kill synergy studies demonstrated bactericidal synergistic activity only for the triple combination . In vivo, monotherapy with vancomycin was not effective . Treatment with either ampicillin or imipenem alone or in combination with vancomycin resulted in <4 log10 reduction in colony-forming units (cfu) per gram of vegetation . The combination of ampicillin with imipenem was highly active (an additional 5 log10 reduction in cfu per gram of vegetation compared with the most active single agent), but efficacy was not increased by the addition of vancomycin to ampicillin and imipenem . Therapy with the combination of ampicillin and imipenem may be effective for some strains of multidrug-resistant enterococcal infections. Plasmid, 1996 Mar, 35(2), 71 - 80 A novel tetracycline-resistant determinant, tet(U), is encoded on the plasmid pKq10 in Enterococcus faecium; Ridenhour MB et al.; Nine tetracycline (Tc)-resistant clinical isolates of Enterococcus faecium were screened for plasmid content using agarose gel electrophoresis . pKQ10, a 1.9-kb plasmid carrying a novel Tc resistance determinant, was isolated from one of the isolates . The nucleotide sequence of this plasmid revealed an open reading frame corresponding to an 11.8-kDa protein and containing 105 amino acid residues . There was some limited similarity between this protein and tet(M), tet(O), tet(Q), tet(S), tetB(P), and otr(A), which overlapped, but did not include, the consensus GTP-binding sequences . The low-level, Tc-resistant determinant of pKQ10, named tet(U), does not appear to correspond to any other known Tc resistance determinant. J Bacteriol, 1996 Mar, 178(6), 1774 - 5 Importance of the E-46-D-160 polypeptide segment of the non-penicillin-binding module for the folding of the low-affinity, multimodular class B penicillin-binding protein 5 of Enterococus hirae; Mollerach ME et al.; Compared with the other class B multimodular penicillin- binding proteins (PBPs), the low-affinity PBP5 responsible for penicillin resistance in Enterococcus hirae R40, has an extended non-penicillin-binding module because of the presence of an approximately 110-amino-acid E-46(-)D-160 insert downstream from the membrane anchor . Expression of pbp5 genes lacking various parts of the insert-encoding region gives rise to proteins that are inert in terms of penicillin binding, showing that during folding of the PBP, the insert plays a role in the acquisition of a correct penicillin-binding configuration by the G-364(-)Q-678 carboxy-terminal module. Arch Surg, 1996 Mar, 131(3), 338 - 42 Antibiotic-resistant enterococci and the changing face of surgical infections; de Vera ME et al.; BACKGROUND: Enterococci have not been thought to play an important role in intra-abdominal infections because of their relatively low virulence . However, this notion is changing because of the recent emergence of these microbes as significant nosocomial pathogens . OBJECTIVES: To review the mechanisms of antibiotic resistance of enterococci and to discuss the significance of multidrug-resistant enterococci in surgical infections . DATA SOURCES: Medical and basic science literature relating to enterococci . DATA SYNTHESIS: In addition to having intrinsic resistance to a number of antibiotics, enterococci have the ability to acquire resistant genes through the exchange of plasmids or transposons from other bacterial species . Moreover, enterococci have been shown to transmit these genes to other bacterial species in turn . The extensive resistance of these microorganisms has led to their emergence as significant nosocomial pathogens, ranking second only to Escherichia coli in the number of pathogenic isolates recovered from patients in intensive care units . There has also been a marked increase in vancomycin-resistant enterococcal infections in surgical patients in the last 5 years . Some studies associate the prior use of vancomycin or third-generation cephalosporins with the emergence of these strains . Overall, enterococcal infections are associated with increased morbidity and mortality . CONCLUSIONS: In view of the marked resistance of enterococci to antibiotics and their ability to disseminate resistance genes, these microbes have become important pathogens . Enterococci pose a threat to surgical patients, often causing significant therapeutic dilemmas. Biochemistry, 1996 Feb 20, 35(7), 2380 - 7 The active-site histidine-10 of enterococcal NADH peroxidase is not essential for catalytic activity; Crane EJ 3rd et al.; In order to test the proposal {Stehle, T., Claiborne, A., & Schulz, G . E . (1993) Eur . J . Biochem . 211, 221-226} that the active-site His10 of NADH peroxidase functions as an essential acid-base catalyst, we have analyzed mutants in which this residue has been replaced by Gln or Ala . The k(cat) values for both H10Q and H10A peroxidases, and the pH profile for k(cat) with H10Q, are very similar to those observed with wild-type peroxidase . Both mutants, however, exhibit K(m)(H2O2) values much higher (50-70-fold) than that for wild-type enzyme, and stopped-flow analysis of the H2O2 reactivity of two-electron reduced H10Q demonstrates that this difference is due to a 150-fold decrease in the second-order rate constant for this reaction with the mutant . Stopped-flow analyses also confirm that reduction of the enzyme by NADH is essentially unaffected by His10 replacement and remains largely rate-limiting in turnover; the formation of an E.NADH intermediate in the conversion of E-->EH2 is confirmed by diode-array spectral analyses with H10A . Both H10Q and H10A mutants, in their oxidized E(FAD, Cys42-sulfenic acid) forms, exhibit enhanced long-wavelength absorbance bands (lambda(max) = 650 nm and 550 nm, respectively), which most likely reflect perturbations in a charge-transfer interaction between the Cys42-sulfenic acid and FAD . Combined with the 50-fold increase in the second-order rate constant for H2O2 inactivation (via Cys42-sulfenic acid oxidation) of the H10Q mutant, these observations support the proposal that His10 functions in part to stabilize the unusual Cys42-sulfenic acid redox center within the active-site environment. J Chemother, 1996 Feb, 8(1), 33 - 6 Vancomycin susceptibility in enterococcal blood isolates in Italy: a multicenter retrospective analysis; Venditti M et al.; A retrospective, multicenter survey was performed to evaluate the frequency of vancomycin resistance among enterococcal blood isolates in Italian hospitals during 1993 . Twenty-four laboratories, representing 21 cities, provided data on 177,623 blood cultures . Of 15,500 positive cultures, 778 (5%) yielded an Enterococcus . Of 362 evaluable cases of enterococcal bacteremia, a vancomycin resistant Enterococcus (VRE) was found in only 6 (1.6%) . Based on these results, VRE bacteremia did not appear to be a major problem in Italian hospitals in 1993. J Antimicrob Chemother, 1996 Feb, 37(2), 323 - 9 Treatment of experimental endocarditis caused by multidrug resistant Enterococcus faecium with ramoplanin and penicillin; Landman D et al.; Antibiotic resistant strains of enterococci are being isolated with increasing frequency . Effective treatment of infections caused by Enterococcus faecium resistant to ampicillin, vancomycin and aminoglycosides has not been established . We studied the activity of ramoplanin, a new lipoglycopeptide antibiotic, against two strains of multidrug resistant E . faecium . In time kill studies, ramoplanin was bactericidal against both strains, but not in the presence of 50% serum . The combination of ramoplanin and penicillin was bactericidal even in the presence of serum . In rabbits with experimental endocarditis neither penicillin nor ramoplanin significantly reduced vegetation colony counts when given alone, although ramoplanin significantly reduced spleen and kidney bacterial counts of both strains . The combination of ramoplanin plus penicillin resulted in a significant reduction of vegetation bacterial counts (-3.2 and -3.7 log10 cfu/g for strains VA3 and MMC3, respectively, P < 0.01) . All spleen cultures and 9 out of 10 kidney cultures from each strain were sterile following combination therapy . While ramoplanin will not be available for parenteral therapy, further research into the development of other lipoglycopeptide antibiotics is warranted. Biochem J, 1996 Feb 1, 313 ( Pt 3), 711 - 5 Peptidoglycan structure of Enterococcus faecium expressing vancomycin resistance of the VanB type; Billot-Klein D et al.; Resistance to glycopeptide antibiotics in enterococci is due to the synthesis of UDP-MurNAc-tetrapeptide-D-lactate (where Mur is muramic acid) replacing the normal UDP-MurNAc-pentapeptide precursor . The peptidoglycan structures of an inducible VanB-type glycopeptide-resistant Enterococcus faecium, D366, and its constitutively resistant derivative, MT9, were determined . Using HPLC, 17 muropeptides were identified and were present regardless of whether resistance was expressed or not . The structures of 15 muropeptides were determined using MS and amino acid analysis . The cross-bridge between D-alanine and L-lysine consisted of one asparagine . No monomer pentapeptide or tetrapeptide-D-lactate could be identified . These results obtained with D366 (non-induced) and MT9 indicate that, in the absence of vancomycin, the cell wall synthetic machinery of E . faecium can process the lactate-containing precursor as efficiently as the normal pentapeptide . In contrast, the presence of subinhibitory inducing concentrations of vancomycin interfered with the synthesis of oligomers. Med J Aust, 1996 Jan 15, 164(2), 116 - 20 Emerging resistance in Enterococcus spp; Heath CH et al.; Enterococcus spp . are becoming increasingly important nosocomial pathogens . They are intrinsically resistant to most antibiotics, and effective therapy depends primarily on the penicillins, vancomycin and the aminoglycosides . Under antibiotic selection pressure they have developed high level resistance to these agents, and the first vancomycin-resistant enterococcal infection in Australia was described recently . The vancomycin-resistance genes are of particular concern because of their potential to transfer to other gram-positive organisms . The prevention and control of resistant enterococci is a major challenge that is best met by a combination of active infection control measures and restriction of broad-spectrum antibiotic use. Nephrologie, 1996, 17(6), 327 - 8 {Acute interstitial nephropathy induced by vancomycin}; Azar R et al.; The authors report a case of tubulo-interstitial nephritis with acute renal failure due to vancomycin used to treat a patient with enterococcus endocarditis . Rechallenge with vancomycin several days after stopping the drug resulted in the appearance of a maculopapular rash and rapid onset of acute oligo-anuric renal failure . Renal biopsy revealed acute interstitial nephritis . This feature is suggestive of cellular mediated hypersensitivity. C R Seances Soc Biol Fil, 1996, 190(4), 467 - 9 {Molecular and epidemiologic aspects of the resistance to antibiotics: example of glycopeptides on enterococci}; Courvalin P; The emergence of glycopeptide resistance in enterococci results in a severe clinical problem . Efforts to limit the spread of glycopeptide-resistant enterococci are now considered essential . The many ways in which the resistant strains can disseminate, both in the community and in hospitals, are a source of difficulty in reaching that goal. Annu Rev Microbiol, 1996, 50, 753 - 89 Bacterial heavy metal resistance: new surprises; Silver S et al.; Bacterial plasmids encode resistance systems for toxic metal ions including Ag+, AsO2-, AsO4(3-), Cd2+, CO2+, CrO4(2-), Cu2+, Hg2+, Ni2+, Pb2+, Sb3+, TeO3(2-), Tl+, and Zn2+ . In addition to understanding of the molecular genetics and environmental roles of these resistances, studies during the last few years have provided surprises and new biochemical mechanisms . Chromosomal determinants of toxic metal resistances are known, and the distinction between plasmid resistances and those from chromosomal genes has blurred, because for some metals (notably mercury and arsenic), the plasmid and chromosomal determinants are basically the same . Other systems, such as copper transport ATPases and metallothionein cation-binding proteins, are only known from chromosomal genes . The largest group of metal resistance systems function by energy-dependent efflux of toxic ions . Some of the efflux systems are ATPases and others are chemiosmotic cation/proton antiporters . The CadA cadmium resistance ATPase of gram-positive bacteria and the CopB copper efflux system of Enterococcus hirae are homologous to P-type ATPases of animals and plants . The CadA ATPase protein has been labeled with 32P from gamma-32P-ATP and drives ATP-dependent Cd2+ uptake by inside-out membrane vesicles . Recently isolated genes defective in the human hereditary diseases of copper metabolism, Menkes syndrome and Wilson's disease, encode P-type ATPases that are more similar to the bacterial CadA and CopB ATPases than to eukaryote ATPases that pump different cations . The arsenic resistance efflux system transports arsenite, using alternatively either a two-component (ArsA and ArsB) ATPase or a single polypeptide (ArsB) functioning as a chemiosmotic transporter . The third gene in the arsenic resistance system, arsC, encodes an enzyme that converts intracellular arsenate {As (V)} to arsenite {As (III)}, the substrate of the efflux system . The three-component Czc (Cd2+, Zn2+, and CO2+) chemiosmotic efflux pump of soil microbes consists of inner membrane (CzcA), outer membrane (CzcC), and membrane-spanning (CzcB) proteins that together transport cations from the cytoplasm across the periplasmic space to the outside of the cell . Finally, the first bacterial metallothionein (which by definition is a small protein that binds metal cations by means of numerous cysteine thiolates) has been characterized in cyanobacteria. J Infect, 1996 Jan, 32(1), 11 - 6 Mechanisms of glycopeptide resistance in enterococci; Arthur M et al.; Inducible resistance to high levels of glycopeptide antibiotics in clinical isolates of enterococci is mediated by Tn1546 or related transposons . Tn1546 encodes the VanH dehydrogenase which reduces pyruvate to D-lactate (D-Lac) and the VanA ligase which catalyses synthesis of the depsipeptide D-alanyl-D-lactate (D-Ala-D-Lac) . The depsipeptide replaces the dipeptide D-Ala-D-Ala leading to production of peptidoglycan precursors which bind glycopeptides with reduced affinity . In addition, Tn1546 encodes the VanX dipeptidase and the VanY D,D-carboxypeptidase that hydrolyse the dipeptide D-Ala-D-Ala and the C-terminal D-Ala residue of the cytoplasmic precursor UDP-MurNAC-L-Ala-gamma-D- Glu-L-Lys-D-Ala-D-Ala, respectively . These two proteins act in series to eliminate D-Ala-D-Ala-containing precursors . VanX is required for resistance whereas VanY only slightly increases the level of resistance mediated by VanH, VanA and VanX. Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 1996 Jan, 81(1), 50 - 2 Prevention of microbial contamination of the dental unit caused by suction into the turbine drive air lines; Ojajarvi J; OBJECTIVE: To determine whether a specially designed antisuction device can prevent the bacterial contamination of the drive air lines of the dental turbine that is caused by suction when the turbine is stopped . STUDY DESIGN: A dental unit with and without the antisuction device and three different types of sterilized handpieces were used in the tests . Each turbine was operated in air, then submerged into a bacterial suspension of E . coli and enterococci for 3 seconds, removed, and stopped . This procedure was repeated 10 times . Possible bacterial contamination of the drive air lines was examined by submersing the head of a sterilized handpiece with the turbine running into a nutrient broth for 30 seconds . The broth was incubated at 35 degrees C up to 2 days . RESULTS: After use of the conventional dental unit, bacterial growth of drive air lines was found in 10 of 150 broth samples . After the installation of the antisuction device no bacterial growth was found in any of the 138 samples . The difference in the contamination frequencies is statistically significant (p = 0.011, Fisher's two-sided exact test) . CONCLUSIONS: The drive air lines of the turbine in the dental unit may become contaminated despite the sterilization of handpieces . The antisuction device installed into the dental unit was found to prevent the contamination . With the exception of possibly immunocompromised patients, the transmission of microbes by exhaust air may be too small to cause infections . However, transmission of oral material between patients should be prevented in dental practice. Clin Infect Dis, 1996 Jan, 22(1), 136 - 7 A citywide survey of vancomycin-resistant Enterococcus--New York City, 1993; Washko R et al.; Vancomycin-resistant Enterococcus (VRE) has become an increasingly important nosocomial pathogen . Questionnaires were sent to all New York City (NYC)-licensed laboratories to ask about testing procedures used, number of isolates identified, species identified, and vancomycin susceptibility for enterococcal isolates in 1993 . Of 127 laboratories, 118 (93%) responded . Fifty-three (45%) of the 118 laboratories reported both the number of enterococcal isolates tested and the number of VRE isolates identified during 1993; 15 (28%) of the 53 laboratories did not isolate VRE, and the remaining 38 laboratories identified 3,822 (8.1%) VRE isolates . VRE was first identified by a NYC-licensed (commercial) laboratory in 1988 . Among NYC hospital laboratories, 65 (97%) of 67 identified at least one VRE isolate during 1989-1993 . This survey demonstrates that there has been a marked increase in the number of VRE isolates identified in NYC laboratories. Chem Biol, 1996 Jan, 3(1), 37 - 44 Synthesis and evaluation of inhibitors of bacterial D-alanine:D-alanine ligases; Ellsworth BA et al.; BACKGROUND: D-Alanine:D-alanine ligase is essential for bacterial cell wall synthesis, assembling one of the subunits used for peptidoglycan crosslinking . The resulting aminoacyl-D-Ala-D-Ala strand is the Achilles' heel of vancomycin-susceptible bacteria; binding of vancomycin to this sequence interferes with crosslinking and blocks cell-wall synthesis . A mutant enzyme (VanA) from vancomycin-resistant Enterococcus faecium has been found to incorporate alpha-hydroxy acids at the terminal site instead of D-Ala; the resulting depsipeptides do not bind vancomycin, yet function in the crosslinking reaction . To investigate the binding specificity of these ligases, we examined their inhibition by a series of substrate analogs . RESULTS: Phosphinate and phosphonate dipeptide analogs (which, after phosphorylation by the enzyme, mimic intermediates in the ligation reaction) were prepared and evaluated as reversible inhibitors of the wild-type ligases DdlA and DdlB from Escherichia coli and of the mutant enzyme VanA . Ki values were calculated for the first stage of inhibitor binding according to a mechanism in which inhibitor competes with D-Ala for both substrate binding sites . DdlA is potently inhibited by phosphinates but not by phosphonates, while DdlB and VanA show little discrimination; both series of compounds inhibit DdlB strongly and VanA weakly . CONCLUSIONS: VanA has greatly reduced affinity for all the ligands studied . The relative affinities of the inhibitors in the reversible binding step are not, however, consistent with the substrate specificities of the enzymes . We propose a mechanism in which proton transfer from the attacking nucleophile to the departing phosphate occurs directly, without intervention of the enzyme. Chem Biol, 1996 Jan, 3(1), 21 - 8 Bacterial resistance to vancomycin: five genes and one missing hydrogen bond tell the story; Walsh CT et al.; A plasmid-borne transposon encodes enzymes and regulator proteins that confer resistance of enterococcal bacteria to the antibiotic vancomycin . Purification and characterization of individual proteins encoded by this operon has helped to elucidate the molecular basis of vancomycin resistance . This new understanding provides opportunities for intervention to reverse resistance. Scand J Infect Dis, 1996, 28(2), 191 - 3 First documented isolation of vancomycin-resistant Enterococcus faecium in Sweden; Melhus A et al.; In recent years enterococci, and Enterococcus faecium in particular, have emerged as important nosocomial pathogens . Of major concern is the increasing antimicrobial resistance to traditionally used agents such as ampicillin, gentamicin and vancomycin . We present a patient with prosthetic heart valves colonized with vancomycin-resistant E . faecium . This is the first reported isolation of vancomycin-resistant E . faecium in Sweden. Infect Control Hosp Epidemiol, 1996 Jan, 17(1), 36 - 41 Resistant enterococci: a prospective study of prevalence, incidence, and factors associated with colonization in a university hospital; Weinstein JW et al.; OBJECTIVE: To determine the prevalence of gastrointestinal tract colonization with antibiotic-resistant enterococci at ward entry and to study the incidence and risk factors for nosocomial acquisition of colonization with resistant enterococci . DESIGN: A prospective cohort study conducted between February 1 and March 15, 1993 . METHODS: Rectal cultures were obtained within 24 hours of admission or transfer onto the study wards and repeated at weekly intervals and at the time of discharge . Patients harboring antibiotic-resistant enterococci at the time of admission or after admission were compared to patients who were not colonized with these organisms . Clinical and epidemiologic risk factors for colonization were abstracted prospectively by daily chart review . Following a univariate analysis of risk factors associated with colonization, a multivariate statistical analysis using three separate models was done . SETTING: A 1,125-bed, tertiary-care teaching hospital in North Carolina . PATIENTS: A total of 350 patients admitted to two general medical wards and the medical intensive care unit during the study period . RESULTS: Antibiotic-resistant enterococci were isolated from 52 patients: 19 were colonized at admission to the study, and 33 later acquired resistant strains . At the time of admission, 5.4% of the patients were colonized with ampicillin-resistant enterococci (ARE), including 1.1% that were colonized with vancomycin-resistant enterococci . Prior hospitalization was associated with colonization with ARE at admission (P = .01) . Independent risk factors for nosocomial acquisition of ARE included treatment with more than three antibiotics, empiric use of antibiotics, use of third-generation cephalosporins, and the use of enteral tube feedings . Antibiotics used prophylactically were not associated with resistant enterococcal colonization . CONCLUSIONS: Our data help to elucidate the epidemiology of gastrointestinal tract colonization with resistant enterococci . We hypothesize that surveillance and control programs will be more likely to succeed if targeted at patients receiving more than three antibiotics, empiric antibiotics, and enteral tube feedings (Infect Control and Hosp Epidemiol 1996;17:36-41). Antimicrob Agents Chemother, 1996 Jan, 40(1), 257 - 9 Penicillin tolerance and modification of lipoteichoic acid associated with expression of vancomycin resistance in VanB-type Enterococcus faecium D366; Gutmann L et al.; Induction of vancomycin resistance in Enterococcus faecium D366, which exhibits a VanB-type resistance, as well as its constitutive expression in MT9, a derivative of D366, was associated with penicillin tolerance as shown by decreased lysis and killing of the cells . This phenomenon was linked neither to decreased expression of the different autolysins nor to their decreased lytic activity on the different cell walls . The only change observed was that almost twice the normal amount of D-alanine was attached to the lipoteichoic acid. Chemotherapy, 1996 Jan-Feb, 42(1), 37 - 46 High-level gentamicin-resistant enterococci: in vitro activity of double and triple combinations of antimicrobial drugs; Ferrara A et al.; The ability of double and triple combinations of antimicrobials with different mechanisms of action, such as teicoplanin, meropenem, gentamicin and sparfloxacin, to achieve synergisms was investigated in vitro on some moderate-level gentamicin-resistant (MLGR: 8 < or = MIC < or = 256 mg/l) and high-level gentamicin-resistant (HLGR: MIC > 500 mg/l) enterococci . On MLGR strains, a constant synergistic effect was achieved by a combination of teicoplanin with gentamicin or with meropenem, while generally addition, sometimes close to synergism, was exhibited by gentamicin-meropenem, gentamicin-sparfloxacin and teicoplanin-sparfloxacin associations . Triple combinations of teicoplanin, meropenem and gentamicin, or teicoplanin, sparfloxacin and gentamicin, always showed a remarkable advantage in terms of synergism over double combinations . On HLGR enterococci, the only double association showing an additive effect, sometimes close to synergism, was teicoplanin plus meropenem, while the triple combination of teicoplanin with gentamicin and meropenem always showed a marked synergistic effect . An effect very close to synergism was also shown by the combination of teicoplanin with sparfloxacin and gentamicin. J Clin Microbiol, 1996 Jan, 34(1), 210 - 2 Comparison of rectal and perirectal swabs for detection of colonization with vancomycin-resistant enterococci; Weinstein JW et al.; Patients whose gastrointestinal tracts are colonized with vancomycin-resistant enterococci (VRE) may serve as a reservoir for nosocomial transmission . We compared the sensitivities and concordance of several methods used to detect VRE colonization . Eighty-two paired rectal and perirectal swabs were obtained from 13 patients over a 9-day period . The sensitivity of both rectal and perirectal swabs was 79% . There was 100% concordance of culture results between simultaneously obtained rectal and perirectal swabs, and the quantities of growth were similar by these two methods of detection . Our data suggest that rectal and perirectal swabs are equally sensitive for the detection of VRE colonization. Postgrad Med J, 1996 Jan, 72(843), 51 - 2 Enterococcal endocarditis after extracorporeal shock wave lithotripsy for nephrolithiasis; Zimhony O et al.; We report a case of enterococcal endocarditis following extracorporeal shock wave lithotripsy (ESWL) for ureteral stone . Although endocarditis following ESWL is very rare, transient bacteraemia occurs during ESWL . This case is a reminder that enterococcal endocarditis may follow innovative genitourinary procedures without appropriate prophylaxis. Vet Microbiol, 1996 Jan, 48(1-2), 29 - 39 The humoral immune response of turbot to recently isolated pathogenic Enterococcus strains . Cross-reactivity with other Gram-positive bacteria; Leiro J et al.; An Enterococcus sp . causing severe mortalities among farmed turbot (Scophthalmus maximus) has recently been detected in northwest Spain . We found that specific turbot serum antibodies raised against isolate RA-99.1 of the new pathogen by intraperitoneal immunization, did not cross react in enzyme-linked immunosorbent assay (ELISA) with other enterococcal or non-enterococcal Gram-positive bacteria . In immunoblotting, antibodies raised against strain RA-99.1 recognized the same components in the homologous total soluble antigen preparation (TSA) as in TSA of two other isolates of the pathogen obtained from different farms . Anti-RA-99.1 serum also recognized some components of the TSA of several other Gram-positive bacteria . Immunogold labelling indicated that the antigens which provoke the humoral immune response to this pathogen are located mainly on the bacterial surface. J Antimicrob Chemother, 1996 Jan, 37(1), 127 - 32 Treatment of experimental endocarditis due to multidrug-resistant Enterococcus faecium with clinafloxacin and penicillin; Zaman MM et al.; Clinafloxacin, a new quinolone antibiotic with enhanced activity against Gram-positive bacteria, has demonstrated in-vitro activity against multidrug-resistant Enterococcus faecium, particularly when combined with penicillin . Rabbits with experimental endocarditis due to a multidrug-resistant strain of E . faecium were treated with clinafloxacin and/or penicillin . After three days of therapy, significant reduction of bacterial concentrations were found in vegetations, kidneys, and spleens of animals treated with clinafloxacin . The combination of clinafloxacin and penicillin was significantly better in reducing vegetation bacterial concentrations compared to the other groups (-4.4 log10 cfu/g compared with control) . Serum levels of clinafloxacin consistently exceeded the MIC of the strain, and clinafloxacin-resistant isolates could not be detected . Clinafloxacin demonstrated promising activity in vivo against multidrug-resistant E . faecium, and further studies are warranted. Proc Natl Acad Sci U S A, 1995 Dec 5, 92(25), 11603 - 7 Phosphinate analogs of D-, D-dipeptides: slow-binding inhibition and proteolysis protection of VanX, a D-, D-dipeptidase required for vancomycin resistance in Enterococcus faecium; Wu Z et al.; VanX is a D-Ala-D-Ala dipeptidase that is essential for vancomycin resistance in Enterococcus faecium . Contrary to most proteases and peptidases, it prefers to hydrolyze the amino substrate but not the related kinetically and thermodynamically more favorable ester substrate D-Ala-D-lactate . The enzymatic activity of VanX was previously found to be inhibited by the phosphinate analogs of the proposed tetrahedral intermediate for hydrolysis of D-Ala-D-Ala . Here we report that such phosphinates are slow-binding inhibitors . D-3-{(1-Aminoethyl)phosphinyl}-D-2-methylpropionic acid I showed a time-dependent onset of inhibition of VanX and a time-dependent return to uninhibited steady-state rates upon dilution of the enzyme/inhibitor mixture . The initial inhibition constant Ki after immediate addition of VanX to phosphinate I to form the E-I complex is 1.5 microM but is then lowered by a relatively slow isomerization step to a second complex, E-I*, with a final K*i of 0.47 microM . This slow-binding inhibition reflects a Km/K*i ratio of 2900:1 . The rate constant for the slow dissociation of complex E-I* is 0.24 min-1 . A phosphinate analog with an ethyl group replacing what would be the side chain of the second D-alanyl residue in the normal tetrahedral adduct gives a K*i value of 90 nM . Partial proteolysis of VanX reveals two protease-sensitive loop regions that are protected by the intermediate analog phosphinate, indicating that they may be part of the VanX active site. Infect Control Hosp Epidemiol, 1995 Dec, 16(12), 680 - 5 Natural history of colonization with vancomycin-resistant Enterococcus faecium; Montecalvo MA et al.; OBJECTIVE: To determine the incidence, duration, and genetic diversity of colonization with vancomycin-resistant Enterococcus faecium (VREF) . SETTING: Oncology unit of a 650-bed university hospital . METHODS: Surveillance perianal swab cultures were performed on admission and weekly . The molecular relatedness of VREF isolates was determined by pulsed-field gel electrophoresis and by the hybridization pattern of the vanA resistance determinant . RESULTS: During 8 months of surveillance, the VREF colonization rate was 16.6 patients per 1,000 patient-hospital days, which was 10.6 times greater than the VREF infection rate . Eighty-six patients with VREF colonization were identified . Colonization persisted for at least 7 weeks in the majority of patients . Of 36 colonized patients discharged from the hospital and then readmitted, an average of 2 1/2 weeks later, 22 (61%) patients still were colonized with VREF . Of the 14 patients who were VREF-negative at readmission, only three patients remained culture-negative throughout hospitalizations . PFGE demonstrated that colonization with the same VREF isolate may persist for at least 1 year, and patients may be colonized with more than one strain of VREF . CONCLUSION: VREF colonization is at least 10-fold more prevalent than infection among oncology patients . Colonization often persists throughout lengthy hospitalizations and may continue for long periods following hospitalization. Indian J Med Res, 1995 Dec, 102, 255 - 7 Determination of high level resistance to aminoglycosides among enterococci; Cherian BP et al.; Two hundred and ten strains of enterococci showing resistance to gentamicin (10 micrograms/disc) were tested for high level resistance by detecting the minimum inhibitory concentration and by using high content disc diffusion test . Only 67 per cent of these had high level resistance to gentamicin . High level kanamycin resistance in the group was 84 per cent, while high level streptomycin resistance was 61 per cent . Only 85 of the 140 strains with high level gentamicin resistance had similar streptomycin resistance . Results using locally made high content discs, correlated 100 per cent with MIC results . High level resistance to enterococci should be reported on a routine basis, especially when isolated from patients with serious infections. J Biol Chem, 1995 Nov 24, 270(47), 28392 - 6 An iron-regulated gene, magA, encoding an iron transport protein of Magnetospirillum sp . strain AMB-1; Nakamura C et al.; Magnetospirillum sp . AMB-1 is a freshwater magnetic bacterium which synthesizes intracellular particles of magnetite (Fe3O4) . A genomic DNA fragment required for synthesis of magnetic particles was previously isolated from a nonmagnetic transposon Tn5 mutant . We have determined the complete nucleotide sequence of this fragment . The 2975-base pair region contains two putative open reading frames . One open reading frame, designated magA, encodes a polypeptide which is homologous to the cation efflux proteins, the Escherichia coli potassium ion-translocating protein, KefC, and the putative Na+/H(+)-antiporter, NapA, from Enterococcus hirae . Northern hybridization demonstrated that the magA mRNA transcript is 1.3 kilobases in size, corresponding to the size of the magA gene . A functional promoter was located upstream from the magA gene, and the transcription in AMB-1 was regulated by environmental iron concentration . Vesicles isolated from E . coli in which the MagA protein was expressed exhibited iron accumulation ability . We consider that the MagA protein is an iron transport involved in the synthesis of magnetic particles in AMB-1. Diagn Microbiol Infect Dis, 1995 Nov, 23(3), 123 - 7 Activity of two novel fluoroquinolones (DU-6859a and DV-7751a) tested against glycopeptide-resistant enterococcal isolates; Jones RN et al.; Two novel fluoroquinolones, DU-6859a and DV-7751a, were compared with three peer compounds (ciprofloxacin, levofloxacin, and ofloxacin) by testing 150 strains of enterococci that were resistant to vancomycin . Standardized methods recommended by the National Committee for Clinical Laboratory Standards were used for all minimum inhibitory concentration tests, and DU-6859a was additionally tested by the standardized disk diffusion procedure (5-mu g disks) . The rank order of the fluoroquinolone spectrums against these Enterococcus spp . isolates was DU-6859a (71.3% of strains inhibited at < or = 2 mu g/ml) > DV-7751a (38.7%) > levofloxacin (33.3%) > ofloxacin (32.0%) > ciprofloxacin (3.3%) . Using previously proposed break point zone diameters of > or = 16 mm (susceptible) and < or = 12 mm (resistant), the DU-6859a disk diffusion tests for these glycopeptide-resistant organisms were without false-susceptible or false-resistant error (81.3% absolute agreement) . These results indicate that among the investigational and currently marketed fluoroquinolones, DU-6859a appears to have the greatest potential value in the therapy of Enterococcus spp . strains that are resistant to the glycopeptides and many other therapeutic agents. Diagn Microbiol Infect Dis, 1995 Nov, 23(3), 119 - 22 Selective media for detecting gastrointestinal carriage of vancomycin-resistant enterococci; Barton AL et al.; Nosocomial infection with vancomycin-resistant enterococci (VRE) has become a significant problem . Effective institution of infection control measures depends on rapid identification of carriage of the organism, especially in asymptomatic individuals . We compared two selective media for use in screening for the presence of VRE and found that an agar medium containing bile esculin azide supplemented with 8 mu g/ml of vancomycin was a useful and cost-effective means for primary screening for asymptomatic gastrointestinal carriage of VRE. Vet Med (Praha), 1995 Nov, 40(11), 337 - 9 {The effect of monensin on a rumen strain of Enterococcus faecium CCM 4231}; Laukova A et al.; Monensin from three different manufacturing companies (Eli Lilly Co., Indianapolis, USA; Pharmachim, Bulgaria; Spofa Prague, Czech Republic) were added to pure cultures of rumen strain Enterococcus faecium CCM 4231 at final concentrations 25 micrograms per ml and 50 microgram per ml . Enterococci represent a strong bacterial group colonizing the rumen regarding to lactic acid production . Ent . faecium CCM 4231 is own, lactic acid-producing isolate from the rumen content of calf with a broad antimicrobial activity (bacteriocin production) . This strain was obtained in the microbial preparation Inhicol to protect enteritis in young ruminants, especially . The growth of CCm 4231 strain was inhibited at both concentrations (25 microgram/ml; 50 micrograms/ml) using all three monensins in comparison with controls (Figs . 1 and 2) . The beginning of the growth inhibition was detected within 2 hours after ionophore addition . Monensin made in Bulgaria was the most effective of all when the three monensins were compared . No significant differences are found in the effect of monensins made in different production companies . Our results extend the knowledge about inhibition effect of monensin on Gram-positive bacteria, enterococci including . Moreover, the quality of monensins made by different companies is attested synchronous . In general, regarding the practical point of view, it is also contribution for the selection and application of the most suitable additives. Eur J Clin Microbiol Infect Dis, 1995 Nov, 14(11), 959 - 63 Epidemiologic analysis of glycopeptide-resistant Enterococcus strains in neutropenic patients receiving prolonged vancomycin administration; Plessis P et al.; Vancomycin-resistant enterococci have been isolated with increasing frequency since 1988 . Thus far, most of these resistant enterococci have belonged to the Enterococcus faecium species, and epidemiological studies have shown a wide diversity among interhospital and intrahospital isolates . This report presents an epidemiologic investigation of 25 vancomycin-resistant Enterococcus strains--24 Enterococcus faecium and one Enterococcus gallinarum--isolated from the stools or blood of adult patients receiving intravenous vancomycin prophylaxis during neutropenia and hospitalized in a single hematologic unit . Macrorestriction patterns of total DNA and of ribosomal DNA regions were used to analyze the strains . Strains produced different total DNA restriction fragment length polymorphism patterns after SmaI digestion . Ribotyping was less discriminative than pulsed-field gel electrophoresis . The results confirmed the genetic unrelatedness of the strains . Prolonged vancomycin administration, commonly used in hematologic units, could be involved in the selection of endogenous resistant enterococcal strains. J Antimicrob Chemother, 1995 Nov, 36(5), 821 - 5 Characterization of vancomycin resistance in Enterococcus durans; Cercenado E et al.; During investigation of an outbreak of vancomycin resistant Enterococcus faecium in a paediatric hospital, an isolate of Enterococcus durans resistant to vancomycin, teicoplanin, ampicillin and highly resistant to gentamicin and streptomycin was found in the stools of a patient also colonized with a strain of E . faecium with the same resistance pattern . Minimal inhibitory concentrations of vancomycin and teicoplanin were 512 and 64 mg/mL, respectively . Resistance to vancomycin as well as high-level resistance to gentamicin was transferable to an E . faecium recipient strain . Both multiresistant E . faecium and E . durans isolates as well as the transconjugant presented only one plasmid . The vanA gene was detected and localized to the high molecular weight plasmid by DNA hybridization with a vanA gene probe . Growth in vancomycin resulted in induction of an approximately 40 kDa protein visible in membrane preparations from these cells . Genetic linkage between vancomycin and gentamicin resistance genes in the same plasmid is suggested. Infect Control Hosp Epidemiol, 1995 Nov, 16(11), 634 - 7 Controlling vancomycin-resistant enterococci; Boyce JM et al.; After controlling an epidemic of vanB-type vancomycin-resistant Enterococcus faecium (VRE), we contained a subsequent vanA E faecium outbreak by using prospective laboratory-based surveillance, placing patients with VRE in private rooms, requiring the use of both gowns and gloves by all personnel entering the patients' rooms, and conducting prevalence surveys of patients on affected wards. Clin Infect Dis, 1995 Nov, 21(5), 1234 - 7 Clinical and molecular epidemiology of vancomycin-resistant Enterococcus faecium during its emergence in a city in southern Texas; Moreno F et al.; During a 19-month period from April 1993 to October 1994, 41 isolates of vancomycin-resistant Enterococcus faecium (VREF) were detected in seven different hospitals in a city in southern Texas . A case-control study to determine the risk factors for acquisition was done in the hospital in which the majority of isolates were detected . Pulsed-field gel electrophoresis (PFGE) of whole-cell DNA was used to determine strain identity . Thirty-five (85%) of the 41 VREF isolates were of the vanB phenotype . Of these, 32 (91%) of 35 were the same strain by PFGE typing . The same vanB strain was documented in five different hospitals in the city . In contrast, 4 (67%) of 6 of the vanA phenotype VREF isolates were distinct strains by PFGE typing . Significant risk factors for colonization or infection with VREF were prior exposure to antibiotics (P = .04), the previous use of third-generation cephalosporins (P = .03), and the previous use of parenteral vancomycin (P = .002) . Infection-control and antibiotic-utilization measures were implemented to control cross-transmission and selection of VREF isolates . During the emergence of VREF in our city, clonal dissemination of a single strain of vanB VREF among six hospitals was documented . Limited cross-transmission of vanA phenotype VREF isolates occurred, but most vanA VREF isolates were distinct strains selected in individual hospital environments. J Clin Microbiol, 1995 Nov, 33(11), 3008 - 18 Multilaboratory evaluation of screening methods for detection of high-level aminoglycoside resistance in enterococci . National Committee for Clinical Laboratory Standards Study Group on Enterococci; Swenson JM et al.; Since the early 1970s, the synergistic activity of an aminoglycoside with a cell wall-active agent has been predicted by determining the ability of an enterococcus to grow in the presence of high levels of the aminoglycoside (usually > or = 2,000 micrograms/ml) . However, a variety of media and concentrations of aminoglycosides has been used for this screening procedure . In the present study, we sought to optimize the agar dilution, broth microdilution, and disk diffusion tests used to detect high-level gentamicin and streptomycin resistance in enterococci . For dilution tests, brain heart infusion agar or broth gave the best growth and performance . For agar dilution, 500 micrograms of gentamicin per ml, 2,000 micrograms of streptomycin per ml, and an inoculum of 1 x 10(6) CFU/ml were optimal, while for broth microdilution, 500 micrograms of gentamicin per ml, 1,000 micrograms of streptomycin per ml, and an inoculum of 5 x 10(5) CFU/ml were best . Growth of more than one colony in the agar dilution test was determined to be the best indicator of high-level resistance . For disk diffusion, Mueller-Hinton agar, 120-micrograms gentamicin disks, and 300-micrograms streptomycin disks with breakpoints of no zone for resistance and > or = 10 mm for susceptibility gave the best sensitivity and specificity if results for strains with zones of 7 to 9 mm are considered inconclusive, indicating that a broth or agar test should be performed to determine susceptibility or resistance. Enferm Infecc Microbiol Clin, 1995 Nov, 13(9), 516 - 21 {Detection of antibiotic resistance in Enterococcus sp . Comparison of GPS-TA (BioMérieux-Vitek), Uniscept MIC-3 (bioMérieux-Vitek) and conventional methods}; Alamo I et al.; BACKGROUND: The treatment of severe enterococcus infections requires synergism of a beta-lactamic or glycopeptide and a aminoglycoside, but when resistance to first one or high-level resistance to aminoglycosides are present, synergism would be lost . We compared the adequacy of two commercially available systems to detect antibiotic resistance . METHODS: We studied 158 isolates of Enterococcus sp., with high-level resistance to gentamicin (40 isolates) and streptomycin (89 isolates), resistance to ciprofloxacin (34 isolates), resistance to ampicillin (7 isolates) and with intermediate susceptibility to vancomycin (3 isolates) . No one was beta-lactamase producer by Cefinase disk method . We use disk diffusion as reference technique to detect high-level streptomycin resistance . The susceptibility to the remainder antibiotics was studied by agar dilution method, according to NCCLS . We studied the accuracy of GPS-TA cards and Uniscept MIC-3 in relation to the degree of agreement with conventional means, following FDA criteria . RESULTS: Essential agreement for MIC was less than 90 with MIC-3 for ampicillin (81.5%) and ciprofloxacin (71.3%) . Categorical agreement rate was less than 90% (76.4%) and major error rate was higher than 3% (10.9%) with the use of MIC-3 for ciprofloxacin . Very major errors for ampicillin, vancomycin and ciprofloxacin were not produced by any system . The very major error rates for high level resistance to gentamicin and streptomycin with GPS-TA card were 5 and 15.7%, respectively . CONCLUSIONS: We do not recommend the use of the Uniscept MIC-3 panel with visual reading to detect susceptibility to ciprofloxacin . Detection of high levels of aminoglucoside resistance by GPS-TA card should be supplemented with conventional techniques because of the high rate of major error . Due to the low number of strains that have been studied, we can not assure the suitability of these systems to detect ampicillin or vancomycin resistance. Biochemistry, 1995 Oct 31, 34(43), 14114 - 24 Analysis of the kinetic mechanism of enterococcal NADH peroxidase reveals catalytic roles for NADH complexes with both oxidized and two-electron-reduced enzyme forms; Crane EJ 3rd et al.; Anaerobic titrations of the two-electron-reduced NADH peroxidase (EH2) with NADH and 3-acetylpyridine adenine dinucleotide (AcPyADH) yield the respective complexes without significant formation of the four-electron-reduced enzyme (EH4) . Further analysis of the EH2/EH4 redox couple, however, yields a midpoint potential of -312 mV for the free enzyme at pH 7 . The catalytic mechanism of the peroxidase has been evaluated with a combination of kinetic and spectroscopic approaches, including initial velocity and enzyme-monitored turnover measurements, anaerobic stopped-flow studies of the reactions of both oxidized enzyme (E) and EH2 with NADH and AcPyADH, and diode-array spectral analyses of both the reduction of E-->EH2 by NADH and the formation of EH2.NADH . Overall, these results are consistent with rapid formation of an E.NADH complex with distinct spectral properties and a rate-limiting hydride transfer step that yields EH2, with no direct evidence for intermediate FADH2 formation . The EH2.NADH complex described previously {Poole, L . B., & Claiborne, A . (1986) J . Biol . Chem . 261, 14525-14533} is not catalytically competent and reacts relatively slowly with H2O2 . Stopped-flow analyses do, however, support the very rapid formation of an EH2.NADH* intermediate, with spectral properties that distinguish it from the static EH2.NADH form, and yield a first-order rate constant for the conversion between the two species that is smaller than kcat . The combined rapid-reaction and steady-state data are best accommodated by a limiting type of ternary complex mechanism very similar to that proposed previously {Parsonage, D., Miller, H., Ross, R.P., & Claiborne, A . (1993) J . Biol . Chem . 268, 3161-3167}. Microb Drug Resist, 1995 Fall, 1(3), 249 - 53 Successful treatment of persistent bacteremia due to vancomycin-resistant, ampicillin-resistant Enterococcus faecium; Mekonen ET et al.; Emergence of vancomycin-resistant enterococci has become an increasing problem in many medical centers . We report a liver transplant recipient with vancomycin-resistant Enterococcus faecium bacteremia who was successfully treated using very high dose continuous infusion ampicillin/sulbactam, plus gentamicin after he remained bacteremic on high dose ampicillin and gentamicin . At our institution, 83% of E . faecium isolates from 1994 were inhibited by ampicillin/sulbactam compared to 66% for ampicillin at an MIC < or = 64 micrograms/ml . None of these strains produced beta-lactamase, suggesting sulbactam may have an unexplained beneficial effect against some enterococci . Although an MIC of < or = 8 micrograms/ml is required for ampicillin to be considered active against enterococci, much higher levels of ampicillin or ampicillin/sulbactam are safely achievable . The response of our patient and the reported in vivo data have implications for future treatment of this pathogen, and may necessitate a reevaluation of susceptibility interpretation guidelines by clinical laboratories, and therapeutic drug dosing by clinicians. Microb Drug Resist, 1995 Fall, 1(3), 245 - 7 Quinupristin/dalfopristin (RP 59500) therapy for vancomycin-resistant Enterococcus faecium aortic graft infection: case report; Sahgal VS et al.; A 46-year-old woman was admitted to the hospital with severe peripheral vascular disease, requiring multiple vascular surgical procedures . During the sixth hospital week, after prior therapy with multiple antibiotics, Enterococcus faecium was isolated as the only organism from an operating room culture of an infected aortic graft . Histological examination of the graft showed infiltration with polymorphonuclear leukocytes . Subsequently, cultures of an infected inguinal wound yielded Enterococcus faecium with mixed bacterial growth . Both isolates of Enterococcus faecium were resistant to all available antimicrobials, including ampicillin, vancomycin, tetracycline, chloramphenicol, and ciprofloxacin . Compassionate use therapy with quinupristin/dalfopristin (RP59500) was administered for 25 days, the patient's clinical condition improved, and wound healing occurred . Transient elevation of serum alkaline phosphatase was noted . This case demonstrates successful eradication of deep VREF infection by quinupristin/dalfopristin with good tolerance of prolonged therapy. Microb Drug Resist, 1995 Fall, 1(3), 241 - 3 Serious infections caused by multiply-resistant Enterococcus faecium; Wade JJ et al.; Three liver transplant patients developed serious intraabdominal infections and recurrent bacteremias due to strains of Enterococcus faecium with high-level resistance to vancomycin . The enterococci were also resistant to all other antibacterials except pristinamycin, which, given orally, proved ineffective . One strain was sensitive to tetracycline . Increasingly, clinicians are likely to encounter infections caused by multiply-resistant enterococci, and these cases illustrate the seriousness of such infections in compromised patients. Ann Pharmacother, 1995 Oct, 29(10), 1022 - 7 Quinupristin/dalfopristin (RP 59500): a new streptogramin antibiotic; Chant C et al.; OBJECTIVE: To review the current knowledge on RP 59500 (quinupristin/dalfopristin, Synercid), a new streptogramin antibiotic, with respect to its pharmacology, pharmacokinetics, pharmacodynamics, mechanism of resistance, and in vitro inhibitory and bactericidal activity . DATA SOURCES: A MEDLINE search using keywords RP 59500, pristinamycin, virginiamycin, and streptogramin was performed . Relevant abstracts presented at recent scientific conferences also were consulted . STUDY SELECTION: Because RP 59500 is a relatively new investigational agent, relevant in vitro and animal studies were selected . All available human studies were included as well . DATA EXTRACTION: Data from in vitro and in vivo studies were included, with particular emphasis on human studies . DATA SYNTHESIS: RP 59500 is a new injectable streptogramin antibiotic consisting of a mixture o 2 synergistic pristinamycin compounds . RP 59500 possesses in vitro inhibitory and bactericidal activity against most isolates of gram-positive organisms including vancomycin-resistant Enterococcus faecium, selected gram-negative bacteria, and most anaerobic organisms . Based on preliminary data, the drug appears to be metabolized rapidly and extensively while exhibiting a significant postantibiotic effect . Data from ongoing clinical trials suggests that RP 59500 is well-tolerated except for mild injection site irritations . However, before the role of RP 59500 within the vast armamentarium of antimicrobials can be elucidated, additional studies need to be conducted to document its clinical efficacy . CONCLUSIONS: Based on in vitro susceptibility testing, in vivo studies, and preliminary clinical data, RP 59500 may be an alternative to the glycopeptides, especially for inherently resistant organisms . Further studies are needed to confirm this agent's in vitro activity and to establish its clinical efficacy. Clin Microbiol Rev, 1995 Oct, 8(4), 585 - 615 Current perspectives on glycopeptide resistance; Woodford N et al.; In the last 5 years, clinical isolates of gram-positive bacteria with intrinsic or acquired resistance to glycopeptide antibiotics have been encountered increasingly . In many of these isolates, resistance arises from an alteration of the antibiotic target site, with the terminal D-alanyl-D-alanine moiety of peptidoglycan precursors being replaced by groups that do not bind glycopeptides . Although the criteria for defining resistance have been revised frequently, the reliable detection of low-level glycopeptide resistance remains problematic and is influenced by the method chosen . Glycopeptide-resistant enterococci have emerged as a particular problem in hospitals, where in addition to sporadic cases, clusters of infections with evidence of interpatient spread have occurred . Studies using molecular typing methods have implicated colonization of patients, staff carriage, and environmental contamination in the dissemination of these bacteria . Choice of antimicrobial therapy for infections caused by glycopeptide-resistant bacteria may be complicated by resistance to other antibiotics . Severe therapeutic difficulties are being encountered among patients infected with enterococci, with some infections being untreatable with currently available antibiotics. Antimicrob Agents Chemother, 1995 Oct, 39(10), 2341 - 4 In vitro interactions between different beta-lactam antibiotics and fosfomycin against bloodstream isolates of enterococci; Pestel M et al.; The effects of 16 different beta-lactam-fosfomycin combinations against 50 bloodstream enterococci were compared by a disk diffusion technique . Cefotaxime exhibited the best interaction . By checkerboard studies, the cefotaxime-fosfomycin combination provided a synergistic bacteriostatic effect against 45 of the 50 isolates (MIC of cefotaxime at which 90% of the isolates were inhibited, >2,048 micrograms/ml; MIC of fosfomycin at which 90% of the isolates were inhibited, 128 micrograms/ml; mean of fractional inhibitory concentration indexes, 0.195) . By killing curves, cefotaxime (at 64 micrograms/ml) combined with fosfomycin (at > or = 64 micrograms/ml) was bactericidal against 6 of 10 strains tested. Thorac Cardiovasc Surg, 1995 Oct, 43(5), 302 - 4 Aortic insufficiency and enterococcal endocarditis complicating systemic lupus erythematosus; Demircin M et al.; A case of aortic valve replacement for aortic insufficiency complicated with enterococcal endocarditis in a patient with systemic lupus erythematosus (SLE) is described . The cardiac complications of SLE may involve the endocardium, myocardium, pericardium, and coronary vessels . Steroids which are used for treatment probably increase the incidence of valve incompetence . Aortic insufficiency or infective endocarditis complicating Libman-Sacks endocarditis is rarely observed and may require valve replacement . Echocardiography is an important diagnostic tool . Renal function, pulmonary status, and cerebral complications require special attention in these patients. Eur J Clin Microbiol Infect Dis, 1995 Oct, 14(10), 878 - 82 Detection of aminoglycoside-penicillin synergy against Enterococcus faecium using high-content aminoglycoside disks; Torres C et al.; Thirty-seven Enterococcus faecium strains were screened for high-level aminoglycoside resistance with an agar diffusion test using high-content aminoglycoside disks (300 micrograms of streptomycin and 120 micrograms of gentamicin, tobramycin, kanamycin or amikacin) . The inhibition zones obtained were correlated with results of time-kill penicillin-aminoglycoside synergy studies . An 11 mm breakpoint differentiated strains susceptible or resistant to the synergy of streptomycin plus penicillin . Irrespective of the inhibition zones obtained with tobramycin and kanamycin disks, Enterococcus faecium strains never showed synergy with penicillin in combination with these aminoglycosides . Penicillin-amikacin synergy cannot be predicted by the amikacin disks . Nevertheless, even though kanamycin disks do not predict penicillin-kanamycin synergy, they can be used to predict penicillin-amikacin synergy . In summary, high-content streptomycin, gentamicin and kanamycin disks can be used to predict the susceptibility of Enterococcus faecium strains to the synergistic combination of penicillin plus one of the aminoglycosides (streptomycin, gentamicin or amikacin, respectively). FEMS Immunol Med Microbiol, 1995 Oct, 12(2), 97 - 112 Cytokine-inducing glycolipids in the lipoteichoic acid fraction from Enterococcus hirae ATCC 9790; Suda Y et al.; Five high molecular weight glycolipids capable of stimulating human peripheral whole-blood cell cultures to cause interleukin 6 (IL-6) and tumor necrosis factor (TNF)-alpha induction were isolated from one of the lipoteichoic acid fractions (LTA-2) extracted from Enterococcus hirae ATCC 9790 (Tsutsui et al., (1991) FEMS Microbiol . Immunol . 76, 211-218) by a combination of hydrophobic interaction and anion-exchange chromatographies . This purification procedure resulted in a remarkable increase in the cytokine-inducing activities on the weight basis of isolated glycolipids (a maximum of 36- and 17-fold increases of IL-6 and TNF-alpha induction, respectively) . The total yield of these bioactive glycolipids amounted to 6 wt% of the parent LTA-2 fraction, while the recovery rate in terms of the cytokine-inducing activities was estimated to be sufficient . The chemical composition and the profile, using SDS-PAGE, revealed that all of the isolated bioactive components were high molecular weight glycolipids, which were distinct from each other and from the parent LTA-2 fraction . These findings suggest that the IL-6 and TNF-alpha-inducing activities previously noted in the parent LTA-2 fraction are not attributable to a chemical entity, the structure of which had been proposed elsewhere (Fischer, W . (1990) in Glycolipids, Phosphoglycolipids and Sulfoglycolipids (Kates, M . ed.) pp . 123-234, Plenum Press, New York), but to the other high molecular weight glycolipids described here. J Clin Microbiol, 1995 Oct, 33(10), 2770 - 3 Vancomycin-dependent Enterococcus faecium isolated from stool following oral vancomycin therapy; Dever LL et al.; The isolation of clinical strains of enterococci requiring vancomycin for growth has only recently been reported . We describe the isolation of Enterococcus faecium requiring vancomycin for growth from the stool of a patient who had completed oral vancomycin therapy . Growth of the vancomycin-dependent E . faecium was supported by ristocetin and D-alanyl-D-alanine but not by daptomycin, teicoplanin, or D,L-alanine . Spontaneous revertants not requiring vancomycin occurred at a rate of 1 in 10(6) . Both the vancomycin-dependent E . faecium and the revertant hybridized with a vanB gene probe and had identical contour-clamped homogeneous electrophoresis patterns . The majority of revertant colonies were resistant to teicoplanin, suggesting constitutive production of the vanB ligase . We believe the vancomycin-dependent E . faecium evolved from a vancomycin-resistant, vancomycin-independent E . faecium in the presence of high concentrations of vancomycin in the intestine. J Bacteriol, 1995 Oct, 177(20), 5912 - 7 Identification of a gene (arpU) controlling muramidase-2 export in Enterococcus hirae; Lleo MM et al.; Muramidase-2 of Enterococcus hirae is a 74-kDa peptidoglycan hydrolase that plays a role in cell wall growth and division . To study its regulation, we isolated a mutant defective in muramidase-2 release under certain growth conditions . This mutant had cell walls which apparently lacked 74-kDa muramidase-2 but which accumulated two proteolytic fragments of 32 and 43 kDa, which exhibited muramidase-2 activity in the membrane fraction . By complementation cloning, we identified a 2.6-kb fragment of the E . hirae chromosome containing a gene cluster coding for proteins of 58 to 137 amino acids . One of these genes (arpU), which encoded a 15.9-kDa protein, was shown to complement the defect of the A9 mutant in trans . We propose that this gene may be involved in the regulation of muramidase-2 export. FEMS Microbiol Lett, 1995 Oct 1, 132(1-2), 107 - 14 Induction of vancomycin resistance in Enterococcus faecium by non-glycopeptide antibiotics; Allen NE et al.; Bacitracin and other antibiotics that inhibit late stages in peptidoglycan biosynthesis induce vancomycin resistance in a high-level, inducibly vancomycin-resistant strain of Enterococcus faecium . Exposure to bacitracin led to synthesis of the lactate-containing UDP-MurNAc-pentadepsipeptide precursor required for vancomycin resistance . These findings indicate that inhibition of peptidoglycan biosynthesis can lead to induction of vancomycin resistance and raise the possibility that multiple signals may serve to induce resistance. Surgery, 1995 Oct, 118(4), 716 - 21; discussion 721-3 Definition of the role of enterococcus in intraabdominal infection: analysis of a prospective randomized trial; Burnett RJ et al.; BACKGROUND . The role of enterococcus in intraabdominal infection is controversial . This study examines the contribution of enterococcus to adverse outcome in a large intraabdominal infection trial . METHODS . A randomized prospective double-blind trial was performed to compare two different antimicrobial regimens in combination with surgical or percutaneous drainage in the treatment of complicated intraabdominal infections . A total of 330 valid patients was enrolled from 22 centers in North America . RESULTS . In 330 valid patients, 71 had enterococcus isolated from the initial drainage of an intraabdominal focus of infection . This finding was associated with a significantly higher treatment failure rate than that of patients without enterococcus (28% versus 14%, p < 0.01) . In addition, only Acute Physiology and Chronic Health Evaluation II score and presence of enterococcus were significant independent predictors of treatment failure when stepwise logistic regression was performed (p < 0.01 and < 0.03) . Risk factors for the presence of enterococcus include age, Acute Physiology and Chronic Health Evaluation II, preinfection hospital length of stay, postoperative infections, and anatomic source of infection . There was no difference between the clinical trial treatment regimens with regard to overall failure, failure associated with enterococcus, or frequency of enterococcal isolation . CONCLUSIONS . This study is the first to report enterococcus as a predictor of treatment failure in complicated intraabdominal infections . This trial also identifies several significant risk factors for the presence of enterococcus in such infections. Orv Hetil, 1995 Oct 1, 136(40), 2161 - 4 {Experience with microbiological studies of the diabetic foot}; Kajetan M et al.; In order to determine the microbiological characteristics of diabetic foot infection, 60 diabetic patients (21 women, 39 men; age between 43 and 89 years with a duration of diabetes from 0.5 to 37 years) were investigated . Immediately after the hospitalisation specimens from infected foot lesions were taken using Port-A-Cul special transport medium . Aerobic cultures were done in all cases according to conventional methods while anaerobic cultures were carried out when clinical signs indicated to perform it . Out of 60 lesions only 2 proved to be sterile . In the remaining 58 patients a total of 138 isolates were found resulting in an average of 2.3 organisms per lesions . Only aerobic isolates were identified in 45 patients whereas anaerobic species were also found in 12 patients . Only Candida was found in 1 patient while Candida in combination with bacterial strains was observed in 3 patients . In antimicrobial susceptibility testing beta-lactamase-stable antibiotics with broad spectrum, covering enterococcus and anaerobic organisms proved to be most effective . Diabetic foot infections have a polymicrobial nature . Antibiotic treatment of infections should be based on the results of microbiological investigation of diabetic foot. J Infect Dis, 1995 Oct, 172(4), 993 - 1000 Epidemiology and mortality risk of vancomycin-resistant enterococcal bloodstream infections; Shay DK et al.; Risk factors for vancomycin-resistant enterococcal (VRE) bloodstream infection (BSI) were studied at a tertiary-care hospital by comparing 46 patients with VRE-BSI with 46 randomly selected patients with vancomycin-susceptible enterococcal (VSE) BSI . Among patients with an enterococcal BSI, risk factors for mortality were determined . Independent risk factors for VRE-BSI were increasing APACHE II score (odds ratio {OR}, 2.3/5-point increase; 95% confidence interval {CI}, 1.4-3.9), receipt of vancomycin (OR, 11; 95% CI, 5.5-21), or diagnosis of hematologic malignancy (OR, 8.4; 95% CI, 3.9-18) . After controlling for APACHE II score and gender, patients with VRE- versus VSE-BSI did not have a significantly elevated risk of mortality (OR, 3.3; 95% CI, 0.7-15) . Five of 28 VRE blood isolates typed using pulsed-field gel electrophoresis had identical banding patterns . These data suggest that increasing severity of illness, underlying disease, and receipt of vancomycin are major risk factors for VRE-BSI. J Biol Chem, 1995 Sep 29, 270(39), 23143 - 9 Cross-talk between the histidine protein kinase VanS and the response regulator PhoB . Characterization and identification of a VanS domain that inhibits activation of PhoB; Fisher SL et al.; VanS is a two-component transmembrane sensory kinase that, together with its response regulator VanR, activates the expression of genes responsible for vancomycin resistance in Enterococcus faecium BM4147 . In this report, we demonstrate that the cytoplasmic domain of VanS (including residues Met95 to Ser384) is capable of high level activation (> 500 fold) of the Escherichia coli response regulator PhoB in vivo in the absence of its signaling kinases PhoR, CreC (PhoM), or acetyl phosphate synthesis . In vitro experiments carried out on the purified proteins confirmed that the activation is due to efficient cross-talk between VanS and PhoB, since phospho-VanS catalyzed transfer of its phosphoryl group to PhoB with approximately 90% transfer in 5 min at a 1:4 VanS/PhoB stoichiometry . However, the rate of transfer was at least 100-fold slower than that observed between phospho-VanS and VanR . The in vivo activation of PhoB was used as a reporter system to identify peptide fragments of VanS capable of interfering with activation by VanS(Met95-Ser384), in order to identify an interaction domain . A library of plasmids encoding fragments of VanS(Met95-Ser384) was constructed using transposon mutagenesis, and a subpopulation of these plasmids encoded peptides that interfered with activation of PhoB by VanS(Met95-Ser384) . A minimal size fragment (Met95-Ile174) was shown to be both necessary and sufficient for potent inhibition (85%) of this activation. Antimicrob Agents Chemother, 1995 Sep, 39(9), 2112 - 5 Characterization of antimicrobial resistance in enterococci of animal origin; Thal LA et al.; Among 97 enterococci cultured from animals, gentamicin MICs were > or = 2,000 micrograms/ml for 9 isolates and between 250 and 1,024 micrograms/ml for 6 isolates . For two isolates tested (gentamicin MICs, 256 and 512 micrograms/ml, respectively), there was no in vitro synergy with penicillin plus gentamicin, resistance was transferable, and there was no hybridization with a probe specific for 6'-aminoglycoside acetyltransferase-2"-aminoglycoside phosphotransferase . The results of the study indicate the presence of a unique gentamicin resistance genotype in enterococci of animal origin. Antimicrob Agents Chemother, 1995 Sep, 39(9), 2068 - 72 Identification of daptomycin-binding proteins in the membrane of Enterococcus hirae; Boaretti M et al.; Daptomycin, a lipopeptide antibiotic active against gram-positive bacteria, was preliminarily shown to inhibit lipoteichoic acid (LTA) synthesis as a consequence of membrane binding in the presence of Ca2+ (P . Canepari, M . Boaretti, M . M . Lleo, and G . Satta, Antimicrob . Agents Chemother . 34:1220-1226, 1990) . In the present study, it is shown that, along with binding bacterial-membrane components, daptomycin binds the protein fraction with a noncovalent bond, as suggested by the instability of the bond in the presence of ionic detergents such as sodium dodecyl sulfate . Analysis of membrane proteins by isoelectric focusing electrophoresis reveals that five bands with isoelectric points ranging from 5.9 to 6.2 bind radioactive daptomycin . These proteins are therefore called daptomycin-binding proteins . In an attempt to correlate these proteins to the main inhibition observed during LTA synthesis, two-dimensional thin-layer chromatography of lipids synthesized during daptomycin treatment was performed . A threefold increase in diglucosyl diacylglycerol is demonstrated, while the compounds phosphatidyl-alpha-kojibiosyldiacylglycerol, glycerophospho-phosphatidyl-alpha-kojibiosyldiacylglycerol, and glycerophospho-kojibiosyldiacylglycerol, which follow diglucosyl diacylglycerol in LTA synthesis, decrease progressively with time during the course of daptomycin treatment. Clin Infect Dis, 1995 Sep, 21(3), 516 - 22 Enterococcal arthritis: case report and review; Raymond NJ et al.; We report a case of septic arthritis due to Enterococcus species and review 18 additional cases reported in the literature from 1966 through 1993 for which clinical or treatment data were available . In 11 of the 19 cases, prosthetic joints were affected (9 knees, 2 hips) and in 8 cases, native joints were affected . Of those patients with prosthetic joint infections, 6 had preexisting osteoarthritis and 3 had rheumatoid arthritis; only one patient with native joint infection had a recognized (although unspecified), preexisting joint abnormality . Pain, fever (temperature, > 37 degrees C), and tenderness were the most common clinical findings in patients with native joint infections . The microbiological diagnosis was made by culture of synovial fluid or synovial tissue (16 of 19), blood (1 of 19), or an unstated specimen (2 of 19) . Polymicrobial infection was present in 6 (32%) of 19 patients . Of fourteen patients treated with either a parenteral penicillin (11 of 19) or a glycopeptide (3 of 19), 11 made an uncomplicated recovery . An aminoglycoside was also used to treat 7 of these 14 patients (4 of these 7 had prosthetic joints) . All 11 prosthetic joint infections were ultimately clinically cured; for most of these patients, the original prosthesis was removed . For two patients with native joint infections, amputation of the infected limb was necessary to cure the infection. Gastroenterol Nurs, 1995 Sep-Oct, 18(5), 177 - 81 Enterococcal nosocomial infection: epidemiology and practice; Aliberti LC; Caring for patients susceptible to enterococcal infections is a part of practice for nurses working in today's hospital units . While enterococci are not particularly virulent organisms, they are well suited to causing infection in hospitalized patients, especially in the very old, the seriously ill, and the immunosuppressed . Despite increased understanding of the clinical threat posed by multiresistant strains of enterococci, the incidence of nosocomial enterococcal infection is growing . In this article the author examines the epidemiology and risk factors for colonization and infection with enterococcal bacteria and provides a brief review of antibiotic sensitivities for the organisms . A case study illustrates the course and consequence of infection with multiresistant enterococcus for the seriously ill patient . The importance of education of health professionals in prevention and control of enterococcal infection and superinfection is discussed. Infect Dis Clin North Am, 1995 Sep, 9(3), 463 - 81 In vitro testing of antimicrobial agents; Woods GL; Indications for determining the inhibitory activity of an antimicrobial agent are well defined, and the data provided by such testing are useful for guiding therapy in a cost-effective manner . Susceptibility test methods with inhibition as an endpoint are standardized, and guidelines regarding methodology, quality control, and reporting are published . The ultimate decision concerning reporting, however, should be made jointly by clinical microbiologists, members of the hospital Pharmacy and Therapeutics or Infection Control Committee, and infectious disease clinicians . The NCCLS also has published tentative guidelines regarding methods for determining bactericidal activity of antimicrobial agents . Given the many biologic and technical variables that influence these tests, standardization is critical for appropriate interpretation of results . In contrast to tests that measure inhibition, however, the clinical value of bactericidal testing is poorly defined, and additional information gained by conducting well-designed, prospective, blinded clinical trials is needed . Methods for determining synergism/antagonism have not been standardized, which makes interpreting results and comparing results of tests performed at different institutions difficult . With the exception of detecting high-level aminoglycoside resistance in enterococci as a means to predict synergism between these drugs and cell wall-active agents, the clinical relevance of assessing synergism is not well documented. J Trauma, 1995 Sep, 39(3), 609 - 11 Nosocomial meningitis caused by multiresistant enterococcus as a life-threatening complication of pelvic injury: case report; Lamer C et al.; Bacterial meningitis after pelvic trauma has never been described . We recently treated a patient who developed, during the course of his hospitalization, multiresistant enterococcal meningitis after severe pelvic injury, including a comminutive sacral fracture . Dural tear may have been the main factor leading to secondary infection of the cerebrospinal fluid . Treatment with intravenous continuous infusion of vancomycin plus rifampin, associated with closed subarachnoid drainage, resulted in a complete cure . Therapeutic cerebrospinal fluid levels of vancomycin were obtained only during the first 8 days of treatment . Use of glycopeptides in meningitis and the role of cerebrospinal fluid drainage are discussed . Physicians should be aware of the diagnosis and therapeutic features of this life-threatening complication. Ann Intern Med, 1995 Aug 15, 123(4), 250 - 9 Enterococci resistant to multiple antimicrobial agents, including vancomycin . Establishment of endemicity in a university medical center; Morris JG Jr et al.; OBJECTIVES: To determine the distribution of and risk factors for colonization and infection with vancomycin-resistant enterococci; to evaluate the molecular epidemiology of these strains; and to assess the effect of interventions, including 1) strict adherence to infection control procedures and 2) restricted use of vancomycin . DESIGN: Problem identification based on descriptive studies, point-prevalence surveys, and case-control studies and followed by specific interventions and evaluation of the response to these interventions . SETTING: University medical center . PARTICIPANTS: All patients hospitalized between May 1992 and June 1994 (59,196 admissions) . MAIN RESULTS: 75 active infections attributed to vancomycin-resistant enterococci were identified . Thirty-one patients (41%) had bloodstream infections and 6 (8%) died . The incidence of active infection was highest in the organ transplantation unit (13.2 infections/1000 admissions) . In the point-prevalence studies, vancomycin-resistant enterococci were isolated from 20% of a random sample of hospitalized patients in July, August, and September 1993 (adjusted prevalence, 16.9%) . Case-control studies showed significant associations between colonization and infection and 1) receipt of antimicrobial agents, particularly vancomycin, and 2) severity of illness . Although several small case clusters had isolates with identical banding patterns on pulsed field gel electrophoresis, at least 45 different banding patterns were noted among medical center isolates . Interventions took place in November and December 1993 . Vancomycin restriction policies resulted in a 59% decrease in intravenous vancomycin use and an 85% decrease in oral vancomycin use . Point-prevalence surveys done in April, May, and June 1994 showed a consistent 20% level of colonization with vancomycin-resistant enterococci strains (adjusted prevalence, 18.7%) . No significant changes were seen in rates of vancomycin-resistant enterococci infection . CONCLUSIONS: Vancomycin-resistant enterococci are an important cause of illness and death in the study institution, particularly among organ transplant recipients and other seriously ill persons; they have also become a common intestinal colonizer among hospitalized patients . The diversity of isolates (based on molecular typing studies) suggests that resistant organisms have been introduced from multiple sources . Interventions that effectively lower the overall level of colonization with vancomycin-resistant enterococci must still be identified. An Med Interna, 1995 Aug, 12(8), 374 - 6 {Synergic effect of a teicoplanin and cefpirome combination with aminoglucosides on enterococci . Therapeutic importance}; Hoyos Lopez A et al.; In this work we have evaluated the in vitro activity of teicoplanin and cefpirome to Enterococcus sp . combined with aminoglycosides gentamicin, tobramycin, netilmicin and amikacin . The combination with a greater percentage of synergy were teicoplanin plus tobramycin (70%), continued by teicoplanin plus gentamicin (69%) and teicoplanin plus netilmicin (58%) . The combination of teicoplanin plus aminoglycosides results of great utility in the treatment os serious infections such as endocarditis, meningitis and bacteremia by enterococci, in allergic cases, or resistance to penicillin. Diagn Microbiol Infect Dis, 1995 Aug, 22(4), 349 - 52 Comparison of the in vitro activity of levofloxacin and other antimicrobial agents against vancomycin-susceptible and vancomycin-resistant Enterococcus species; Hayden MK et al.; The in vitro activities of levofloxacin and other antibiotics against 133 clinical isolates of vancomycin-resistant and vancomycin-susceptible enterococci were evaluated . Only 14 (39%) of the vancomycin-susceptible isolates and 11 (11%) of the vancomycin-resistant isolates were susceptible to levofloxacin . Levofloxacin exhibited a marked inoculum effect for all enterococci tested . These results suggest that levofloxacin may be of limited use in the treatment of serious enterococcal infections. Antimicrob Agents Chemother, 1995 Aug, 39(8), 1772 - 8 Use of primers selective for vancomycin resistance genes to determine van genotype in enterococci and to study gene organization in VanA isolates; Miele A et al.; Vancomycin resistance in enterococci is an emerging therapeutic problem . Resistance is not always detected by standard microbiological methods . Oligonucleotide primers for PCR were designed to target amplification of defined regions of genes of the vanA cluster, as well as vanB and vanC1 . These primers correctly identified 30 vancomycin-resistant isolates tested (17 VanA, 7 VanB, and 6 Enterococcus gallinarum) . No amplification was observed with Enterococcus casseliflavus or vancomycin-susceptible strains . Using PCR and Southern blotting, we found that all 17 VanA isolates had orf-1, orf-2, vanR, vanS, vanH, vanA, and vanY genes in the same sequence and that the intergenic distances in the vanR-vanA segments were the same . The described methods should be applicable to the rapid detection of the different vancomycin resistance genotypes in enterococci. MMWR Morb Mortal Wkly Rep, 1995 Jul 14, 44(27), 504 - 6 Statewide surveillance for antibiotic-resistant bacteria--New Jersey, 1992-1994; Vancomycin-resistant Enterococcus faecium sepsis following persistent colonization; Department of Medicine, Northwestern University Medical School, Chicago, Ill., USAVancomycin-resistant enterococci have emerged as important nosocomial pathogens and represent a serious threat to patients with impaired host defenses . We describe a patient with leukemia who developed prolonged colonization with vancomycin-resistant Enterococcus faecium and ultimately died of sepsis due to this multidrug-resistant organism . This case report confirms that colonization with vancomycin-resistant enterococci may last indefinitely and that asymptomatic carriage can lead to invasive infection. J Antimicrob Chemother, 1995 Jul, 36(1), 253 - 8 Ampicillin plus ciprofloxacin therapy of experimental endocarditis caused by multidrug-resistant Enterococcus faecium; Landman D et al.; The combination of ampicillin and ciprofloxacin displayed bactericidal in-vitro activity against two strains of Enterococcus faecium which were highly resistant to ampicillin, vancomycin, and aminoglycosides . This antibiotic combination was used to treat rabbits with experimental endocarditis caused by these strains . Although a significant decrease in vegetation bacterial counts occurred with one strain, the degree of killing did not approach that of penicillin with an aminoglycoside against susceptible enterococci. J Antimicrob Chemother, 1995 Jul, 36(1), 237 - 40 Detection of high- and moderately high-level resistance to gentamicin and streptomycin in Enterococcus faecium by a disc diffusion method; Lopardo H et al.; We evaluated an agar disc diffusion test for the detection of high-level (> or = 2000 mg/L) and moderately high-level resistance to gentamicin (MIC, > or = 128- < or = 1024 mg/L) and streptomycin (MIC, > or = 256- < or = 1024 micrograms/ml) with 70 clinical isolates of Enterococcus faecium . Results obtained using disks containing 120 micrograms gentamicin and 300 micrograms streptomycin were compared with MICs determined by an agar dilution method . Based on the scattergrams, the closest zone diameter correlations with MIC breakpoints were as follows: susceptible, > or = 16 mm; and resistant, < or = 10 mm, for both streptomycin and gentamicin . No major or very major errors were found with either aminoglycoside using these values . We conclude that agar disk diffusion test can be used to accurately detect high-level or moderately high-level gentamicin and streptomycin resistance in E . faecium. J Hepatol, 1995 Jul, 23(1), 39 - 46 Long-term effects of Enterococcus faecium SF68 versus lactulose in the treatment of patients with cirrhosis and grade 1-2 hepatic encephalopathy; Loguercio C et al.; In 40 patients with cirrhosis on a dietary protein regimen of 1 g/kg b.w., we determined the effect on chronic hepatic encephalopathy of long-term administration of Enterococcus faecium (SF68) versus lactulose . The patients received one of the two treatments for three periods of 4 weeks, each separated by drug-free 2-week intervals . The efficacy of treatment was assessed by arterial blood ammonia concentration, mental status, number connection (Reitan's part A) test and flash-evoked visual potentials . At the end of the third period the reduction in both blood ammonia concentrations and Reitan's test times was more enhanced in patients on SF68 than in patients on lactulose . Furthermore, while patients on lactulose tended to return to basal values during drug-free intervals, responders in the SF68 group maintained improvement throughout the study . In conclusion, SF68 is at least as useful as lactulose for the chronic treatment of chronic hepatic encephalopathy; it has no adverse effects, and treatment can be interrupted for 2 weeks without losing the beneficial effects. Med Clin North Am, 1995 Jul, 79(4), 935 - 42 Antibiotic therapy in the allergic patient; Segreti J et al.; A variety of antimicrobial classes are now available . Thus, a careful history and skin testing for hypersensitivity reactions are often not done . It is often easier to give an alternative agent rather than to determine if the person does indeed have a hypersensitivity reaction to a particular drug . There remain situations (e.g., enterococcal endocarditis, neurosyphilis, syphilis in pregnant women), however, in which options for appropriate therapy are limited . In this setting, an accurate history accompanied by appropriate skin testing and desensitization is indicated. Med Clin North Am, 1995 Jul, 79(4), 761 - 87 Aminoglycosides; Lortholary O et al.; Despite their nephrotoxic and ototoxic side effects, AG remain useful antibiotics because of their major, rapid, and dose-dependent bactericidal effects . Combination therapy with an AG appears particularly important in neutropenic and other high-risk patients to provide broad-spectrum bactericidal activity, synergism, and reduction of emergence of resistant pathogens . OD AG therapy is associated with high peak levels in serum that maintain efficacy and low-to-undetectable trough levels in serum that attenuate the risk of toxicity . Administration of short-term OD AG therapy to patients not at risk without renal impairment may not absolutely require dosing monitoring . This therapeutic strategy has been proved useful in clinical trials, now including febrile episodes in neutropenic patients, but it should be avoided during infections in which antimicrobial synergism is required, such as enterococcal endocarditis. Medicine (Baltimore), 1995 Jul, 74(4), 191 - 200 An analysis of 110 serious enterococcal infections . Epidemiology, antibiotic susceptibility, and outcome; Patterson JE et al.; A prospective, observational study of 110 patients with serious infections due to Enterococcus spp . in 6 university and community teaching hospitals in Connecticut was conducted to define the epidemiology of community and nosocomial serious enterococcal infections and to determine risk factors, including antibiotic resistances, that contribute to outcome . Serious community and nosocomial enterococcal infections involved a variety of sites, and antibiotic resistance was common . Types of infection by major organ system were cardiovascular, 54% (catheter-related bacteremia 28%, primary bacteremia 18%, endocarditis 6%, septic thrombophlebitis 1%); intra-abdominal, 13% (including cholangitis, 6%); renal, 13%; skin and soft tissue, 5%; bone and joint, 4%; pleuropulmonary, 4%; central nervous system, 3%; deep surgical wound, 3%; and endometritis, 2% . Sixty-one percent of infections were nosocomial; 48% of these occurred in the intensive care unit . Enterococcus faecium was responsible for 20% of all infections . Antibiotic resistances among the infections included high-level gentamicin resistance (26%), ampicillin resistance (10%), and vancomycin resistance (8%) . Clinical cure was achieved in 64% of patients; 6.8% of patients relapsed, 6.8% had recurrence of the infection with a different pathogen, and overall mortality was 23% . Ampicillin resistance and a high acute physiology and chronic health evaluation (APACHE) II score were highly predictive of lack of cure. Antimicrob Agents Chemother, 1995 Jul, 39(7), 1480 - 4 Inducible and constitutive expression of vanC-1-encoded resistance to vancomycin in Enterococcus gallinarum; Sahm DF et al.; Clinical isolates Enterococcus gallinarum AIB39 and E . gallinarum GS1 were studied to establish whether the expression of vanC-1-mediated resistance may be inducible or constitutive . By growth curve analysis, strain AIB39 exhibited the same lag period (i.e., 1 to 1.5 h) whether it was subcultured to unsupplemented brain heart infusion broth or broth containing 6 micrograms of vancomycin per ml, a growth pattern typical of constitutively expressed resistance . Use of high-performance liquid chromatography (HPLC) to separate peptidoglycan precursor extracts substantiated this finding because the serine-terminating pentapeptide precursor UDP-MurNAc-L-Ala-D-Glu-L-Lys-D-Ala-D-Ser was produced in the presence and absence of vancomycin, whereas no UDP-MurNAc-L-Ala-D-Glu-L-Lys-D-Ala-D-Ala was detected . In contrast, results with strain GS1 were consistent with inducible expression . GS1 demonstrated a lag time that was 3 to 4 h longer when it was subcultured to vancomycin-containing broth than when it was subcultured in unsupplemented broth . HPLC analysis showed that in the absence of vancomycin only UDP-MurNAc-L-Ala-D-Glu-L-Lys-D-Ala-D-Ala was detected, but in the presence of drug only UDP-MurNAc-L-Ala-D-Glu-L-Lys-D-Ala-D-Ala was found . Inducible expression of vanC-1-mediated resistance in E . gallinarum is consistent with recent findings suggesting the presence of at least two ligases in this species . Although vanC-1 may be intrinsic to E . gallinarum, our findings raise doubt regarding the natural mechanism of this gene's expression. Pediatr Clin North Am, 1995 Jun, 42(3), 717 - 35 New antimicrobial agents; Goldfarb J; In any discussion of new antimicrobial agents in the 1990s, a warning and a plea are necessary . The spreading emergence of resistance among bacteria raises concerns for the effectiveness of antimicrobial therapy . Penicillin-resistant pneumococci are probably of most significance in pediatrics and are increasing in frequency, in part related to the use of antimicrobial therapy in young children to treat such infections as otitis media . New practice guidelines have suggested the more limited use of antimicrobial agents in treating serious otitis media . When pediatricians do treat, they should select effective agents . Limiting therapy to brief courses with effective and narrow-spectrum agents may be helpful also . Treating long enough to ensure eradication in serious infections is equally important . Methicillin-resistant S aureus are also increasing and are increasingly a concern in community-acquired infections and nosocomial infections . Using topical agents, such as mupirocin, to treat impetigo and other superficial skin infections can limit exposure to systemic agents and may delay the spread of resistance . Vancomycin-resistant enterococcal infections, an infrequent pediatric problem, are most frightening because no alternative therapies are available . Their occurrence is directly related to use of vancomycin in the communities that are affected . Containing the spread of drug-resistant bacteria will likely require a concerted effort by both physicians and the public . The indiscriminate use of antimicrobial agents to treat non-bacterial infections should be contained . The public must be educated to understand that antimicrobial agents are ineffective against viral infections . In the setting of managed care, educating administrators who make practice decisions that cheaper is not always better will be crucial . The issues of day-care infections and spread of potential pathogens must take on increasing attention and methods to decrease infection sought . Curbing inappropriate use of antimicrobial agents will be as important as learning the nuances between new agents. Pediatr Clin North Am, 1995 Jun, 42(3), 703 - 16 Reducing the spread of antimicrobial-resistant microorganisms . Control of vancomycin-resistant enterococci; Shay DK et al.; Strategies to reduce the spread of hospital-acquired microorganisms resistant to multiple antimicrobial agents are discussed . Because hospitals have experienced a rapid increase in the incidence of infection and colonization with vancomycin-resistant enterococci (VRE) in the past 5 years, the Hospital Infection Control Practices Advisory Committee of the Centers for Disease Control and Prevention has issued recommendations for preventing the spread of vancomycin resistance . Controlling VRE dissemination in pediatric patients requires prompt detection of VRE by microbiology laboratories, education of staff and families about VRE, use of infection control measures to prevent person-to-person VRE transmission, and prudent vancomycin use. J Clin Microbiol, 1995 Jun, 33(6), 1554 - 7 Comparison of field inversion gel electrophoresis with contour-clamped homogeneous electric field electrophoresis as a typing method for Enterococcus faecium; Green M et al.; Direct comparisons between contour-clamped homogeneous electric field (CHEF) electrophoresis and field inversion gel electrophoresis (FIGE) to determine the epidemiology of antibiotic-resistant enterococci have not been previously published . Fifty non-beta-lactamase-producing, ampicillin-resistant Enterococcus faecium isolates and 10 vancomycin-resistant E . faecium strains collected from multiple centers were analyzed in a blinded fashion by CHEF electrophoresis and FIGE after digestion with SmaI . Isolates were considered clonally related if there was a difference of three of fewer bands between electrophoretic patterns . Agreement between CHEF electrophoresis and FIGE was seen for 12 of 13 identified groups of ampicillin-resistant E . faecium and 7 of 7 groups of vancomycin-resistant E . faecium . The lone discordance was accounted for by a fourth band difference between two strains recognized near 350 kb by CHEF electrophoresis but not by FIGE, placing them into different clonal groups . Better band separation was noted in the 50- to 200-kb range for FIGE, while CHEF electrophoresis revealed better resolution over 250 kb more reliably, including detection of some bands not seen on FIGE . Molecular epidemiologic investigations of E . faecium by either technique should provide comparable results. J Clin Microbiol, 1995 Jun, 33(6), 1524 - 7 Ability of commercial and reference antimicrobial susceptibility testing methods to detect vancomycin resistance in enterococci; Tenover FC et al.; We evaluated the abilities of 10 commercially available antimicrobial susceptibility testing methods and four reference methods (agar dilution, broth microdilution, disk diffusion, and the agar screen plate) to classify enterococci correctly as vancomycin susceptible or resistant using 50 well-characterized strains of enterococci . There was a high level of agreement of category classification data obtained with broth-based systems (Sceptor, MicroMedia, Pasco, and Sensititre), agar dilution, and an antibiotic gradient method (E test) with data obtained by reference broth microdilution; no very major or major errors were seen, and minor errors were < or = 6% . Increased minor error rates were observed with disk diffusion (12%), Alamar (16%), Uniscept (16%), and conventional (overnight) MicroScan panels (16%) . The errors were primarily with Enterococcus casseliflavus strains and organisms containing the vanB vancomycin resistance gene . Very major error rates of 10.3 and 20.7% were observed with Vitek and MicroScan Rapid (MS/Rapid) systems, respectively; however, only the MS/Rapid system produced major errors (13.3%) . On repeat testing of discrepant isolates, the very major error rate with the Vitek system dropped to 3.4%, while the very major error rate with the MS/Rapid system increased to 27.6%; major errors with the MS/Rapid system were not resolved . Many of the commercial systems had only 4 dilutions of vancomycin, which resulted in up to 84% of values being off scale (e.g., Uniscept) . Of the methods tested, most conventional broth- and agar-based methods proved to be highly accurate when incubation was done for a full 24 h, although several of the tests had high minor error rates . Automated systems continued to demonstrate problems in detecting low-level resistance. J Hosp Infect, 1995 Jun, 30 Suppl, 483 - 93 The emergence of Enterococcus faecium resistant to glycopeptides and other standard agents--a preliminary report; Wade JJ; We describe the emergence of vancomycin-resistant (VmR) Enterococcus faecium on a liver unit . Over a 22 month period, 110 patients acquired VmR E . faecium . Ribotyping identified 116 patient isolates . Five ribotypes accounted for 78% of patient isolates, the maximum number of patient isolates of a single ribotype was 37, and five clusters of four ribotypes were found . Seven patients acquired more than one ribotype . Environmental sampling yielded VmR E . faecium of the same ribotype as concurrent patient isolates . Clinical specimens from 38 liver transplant patients yielded VmR E . faecium and these were compared to 29 who acquired vancomycin-sensitive (VmS) E . faecium . Logistic regression analysis indicated that duration of admission was the only independent risk factor for acquisition of VmR E . faecium. J Antimicrob Chemother, 1995 Jun, 35(6), 877 - 81 In-vitro activity of two glycylcyclines against enterococci resistant to other agents; Fraise AP et al.; Two new glycylcyclines, CL 329,998 and CL 331,002, were tested for in-vitro activity against 178 clinical strains of enterococci which were resistant to one or more of the commonly used agents (ampicillin, high level gentamicin, vancomycin and teicoplanin) . Both glycylcyclines demonstrated good activity (MICs < or = 0.5 mg/L) against all isolates tested, including those strains which demonstrated multiple resistance . As resistant enterococci are increasing in importance, new agents with activity against these strains are urgently required . Glycylcyclines have in-vitro activity which suggests they may be useful agents for treatment of infections caused by these organisms. J Antimicrob Chemother, 1995 Jun, 35(6), 855 - 64 Intravenous ciprofloxacin as treatment for patients with acute suppurative cholangitis: a randomized, controlled clinical trial; Sung JJ et al.; One hundred consecutive patients with acute suppurative cholangitis were randomized in a prospective, controlled clinical trial to receive either ciprofloxacin (200 mg bd iv) or triple therapy comprising ceftazidime (1 g bd iv), ampicillin (500 mg qds iv) and metronidazole (500 mg tds iv); 46 and 44 patients in the ciprofloxacin and triple therapy groups respectively were suitable for inclusion in the analysis of efficacy . In two-thirds of the patients biliary obstruction was caused by ductal calculi and in one-third by malignant or benign strictures of the biliary tract . Bacteraemia was documented in 38% of patients in the ciprofloxacin group and in 34% of patients in the triple therapy group, while bile cultures were positive in 87% and 92% of patients in the ciprofloxacin and triple therapy groups respectively . Escherichia coli, Klebsiella spp . and Enterococcus spp . were the most common biliary isolates . Eighty-five per cent of evaluable patients in the ciprofloxacin group and 77% of those in the triple therapy group responded to therapy . The mean durations of fever, septicaemic shock and hospitalization were also similar in the two treatment groups . Six (13%) patients in the ciprofloxacin group and seven (16%) in the triple therapy group required urgent endoscopy or surgery for uncontrolled infection . Recurrence of fever after an initial response was documented in one (2%) patient receiving ciprofloxacin and in three (7%) patients receiving triple therapy . The incidences of mortality were 4% in the ciprofloxacin group and 2% in the triple therapy group . The results of this study suggest that ciprofloxacin alone is adequate empirical therapy for patients with cholangitis. Curr Microbiol, 1995 May, 30(5), 265 - 8 Hemagglutination properties of Enterococcus; Carvalho Mda G et al.; In total, 86 enterococcal strains including representatives of most of the described species were tested for the ability to agglutinate human, sheep, and rabbit erythrocytes . Five strains did not react with any of the erythrocytes tested, and 81 (94.2%) strains agglutinated only rabbit erythrocytes . The hemagglutination titers ranged from 2 to 64 . Loss of the hemagglutination activity was observed when rabbit erythrocytes were treated with trypsin or neuraminidase . Trypsin treatment of the bacterial suspensions also caused loss of the agglutination ability . On the other hand, heat treatment of bacterial suspensions increased the efficiency of the interactions, and higher titers were obtained . Assays for inhibition of hemagglutination were performed with alpha-D-fucose, alpha-D-galactose, beta-D-galactose, D-glucose, N-acetyl-galactosamine, N-acetyl-glucosamine, N-acetylneuraminic acid, N-acetylneuraminic acid-lactose, and fetuin . Only fetuin was able to inhibit the hemagglutination reactions . The results showed that hemagglutination properties are common to the different enterococcal species tested . They also suggest that enterococci possess hemagglutinins of proteic and non-proteic nature that are involved in the attachment to sialic acid-containing receptors on the surface of rabbit erythrocytes. Am J Surg, 1995 May, 169(5A Suppl), 8S - 12S Multidrug-resistant enterococci: a threat to the surgical patient; Low DE et al.; The enterococcus has become an important nosocomial pathogen, reported by the National Nosocomial Infections Surveillance System as the third most common pathogen associated with blood-stream infections and the second most commonly isolated pathogen overall . It is now more frequently recognized as a cause of superinfection in the surgical patient, as the possible result of the frequent use of ineffective antimicrobials for prophylaxis and treatment . Both of these findings are due, in part, to the intrinsic antimicrobial resistance of the enterococci . Of greater concern is the ready ability of this organism to acquire resistance traits . During the past 5 years, the appearance and rapid dissemination of strains with high-level resistance to vancomycin, ampicillin, gentamicin, and streptomycin have been reported; in some cases, no effective antimicrobial therapy was available to patients infected with these strains . Enterococci, in addition to their intrinsic and acquired tolerance to beta-lactams, have acquired the ability to inactivate penicillin and ampicillin via beta-lactamase production . Prompt recognition of such multiresistant enterococci, the implementation of effective infection control precautions, and rational use of antimicrobials may limit or even prevent the spread of such strains in the hospital setting. Chemotherapy, 1995 May-Jun, 41(3), 165 - 71 Penicillin resistance and aminoglycoside-penicillin synergy in enterococci; Lopardo HA et al.; Susceptibility to penicillin, vancomycin, imipenem, streptomycin, kanamycin and gentamicin was tested in 130 clinical isolates of Enterococcus spp . by an agar dilution method . Penicillin resistance (MIC > 8 mg/l) was only observed among strains of Enterococcus faecium and Enterococcus raffinosus . Thirty-nine percent of the penicillin-resistant enterococci showed low-level resistance to at least one of the three aminoglycosides tested (gentamicin, kanamycin and streptomycin) . Six Enterococcus strains (5 E . faecium and 1 E . raffinosus) with low-level resistance to gentamicin and different MICs for penicillin were tested for antibiotic synergy using time-killing curves . When penicillin concentrations equal to or higher than the MICs were used, synergism was established, even when highly penicillin-resistant strains (MIC > 200 mg/l) were tested . No synergy was observed when penicillin concentrations were below the MICs. Clin Infect Dis, 1995 May, 20(5), 1137 - 44 Chloramphenicol for the treatment of vancomycin-resistant enterococcal infections; Norris AH et al.; A retrospective study of patients who received chloramphenicol for the treatment of serious vancomycin-resistant enterococcal infections between 1 January 1993 and 31 August 1993 was conducted at the University of Pennsylvania Medical Center (Philadelphia) . Antimicrobial susceptibilities as well as the clinical course of infection, adverse events, and response to therapy of 16 patients were reviewed . Forty-seven percent of enterococcal isolates were susceptible only to chloramphenicol, tetracycline, and nitrofurantoin . Types of infection included bacteremias (n = 7), abscesses (n = 7), and others (n = 5) . Of 14 patients for whom a clinical response could be ascertained, eight (57%) showed improvement after treatment . Of 11 patients for whom a microbiological response could be ascertained, eight (73%) had sterile cultures after treatment . No lasting adverse effect related to the drug occurred . In-hospital mortality was 56%, but only one death could be directly attributed to vancomycin-resistant enterococcal infection . Chloramphenicol appears to be a useful and well-tolerated agent for the treatment of serious vancomycin-resistant enterococcal infections. Clin Infect Dis, 1995 May, 20(5), 1126 - 33 Vancomycin-resistant Enterococcus faecium bacteremia: risk factors for infection; Edmond MB et al.; We describe an outbreak of vancomycin-resistant Enterococcus faecium (vanA phenotype) bacteremia on the oncology ward of a tertiary care community hospital . In 10 of the 11 cases the patients had leukemia and were neutropenic (median duration of neutropenia, 21 days) at the time of bacteremia . On average, patients received six antibiotic agents for a total of 61 agent-days prior to development of vancomycin-resistant E . faecium bacteremia . The mortality rate was 73% . Molecular typing of 22 isolates revealed that the majority (83%) represented a common strain, indicating nosocomial spread . When the 11 cases were compared to 22 matched control patients, gastrointestinal colonization with vancomycin-resistant E . faecium (odds ratio {denominator, 0} infinity, P = .005) and the use of antimicrobial agents with significant activity against anaerobes (metronidazole, clindamycin, and imipenem; odds ratio infinity, P = .02) were found to be risk factors for the development of vancomycin-resistant E . faecium bacteremia . Since no proven therapy for such infection exists, there is an urgent need to identify effective measures to prevent and control the development of vancomycin-resistant E . faecium bacteremia. J Biol Chem, 1995 Apr 21, 270(16), 9217 - 21 Copper and silver transport by CopB-ATPase in membrane vesicles of Enterococcus hirae; Solioz M et al.; The P-type ATPase, CopB, of Enterococcus hirae is required for the copper resistance displayed by this organism and thus was postulated to be a copper pump . Using 64Cu+ and 110mAg+, we here show ATP-driven copper and silver accumulation catalyzed by CopB in native inside-out membrane vesicles of E . hirae . CopB ATPase exhibited an apparent Km for Cu+ and Ag+ of 1 microM and for ATP of 10 microM . Transport was maximal at pH 6 and had an apparent Vmax of 0.07 nmol.min-1.mg-1 for both copper and silver transport . Vanadate displayed a biphasic effect on transport: maximal inhibition was observed at 40 microM vanadate for copper transport and 60 microM for silver transport, respectively . At higher vanadate concentrations, these inhibitions were reversed . The CopB ATPase of E . hirae is thus a pump for the extrusion of monovalent copper and silver ions, with copper probably being the natural substrate. Biochemistry, 1995 Apr 18, 34(15), 5180 - 90 An L40C mutation converts the cysteine-sulfenic acid redox center in enterococcal NADH peroxidase to a disulfide; Miller H et al.; Multiple sequence alignments including the enterococcal NADH peroxidase and NADH oxidase indicate that residues Ser38 and Cys42 align with the two cysteines of the redox-active disulfides found in glutathione reductase (GR), lipoamide dehydrogenase, mercuric reductase, and trypanothione reductase . In order to evaluate those structural determinants involved in the selection of the cysteine-sulfenic acid (Cys-SOH) redox centers found in the two peroxide reductases and the redox-active disulfides present in the GR class of disulfide reductases, NADH peroxidase residues Ser38, Phe39, Leu40, and Ser41 have been individually replaced with Cys . Both the F39C and L40C mutant peroxidases yield active-site disulfides involving the new Cys and the native Cys42; formation of the Cys39-Cys42 disulfide, however, precludes binding of the FAD coenzyme . In contrast, the L40C mutant contains tightly-bound FAD and has been analyzed by both kinetic and spectroscopic approaches . In addition, the L40C and S41C mutant structures have been determined at 2.1 and 2.0 A resolution, respectively, by X-ray crystallography . Formation of the Cys40-Cys42 disulfide bond requires a movement of Cys42-SG to a new position 5.9 A from the flavin-C(4a) position; this is consistent with the inability of the new disulfide to function as a redox center in concert with the flavin . Stereochemical constraints prohibit formation of the Cys41-Cys42 disulfide in the latter mutant. J Clin Microbiol, 1995 Apr, 33(4), 791 - 3 Detection of vancomycin resistance in enterococci by the Alamar MIC system; Zabransky RJ et al.; The ability of the Alamar microdilution MIC system to detect vancomycin resistance in enterococci was evaluated by comparing the results with an agar dilution screen method . Of 100 strains tested, 41 were resistant and 47 were susceptible by both tests . Five strains were intermediate and one was resistant by the Alamar MIC system but susceptible by the agar screen . Three strains each were susceptible or intermediate by the Alamar MIC system but resistant by the agar screen . The predictive values for the Alamar MIC system were 94% (susceptible) and 88% (combined intermediate and resistant) . The Alamar MIC system does not appear to have sufficient accuracy for the detection or confirmation of vancomycin resistance in enterococci. Antimicrob Agents Chemother, 1995 Apr, 39(4), 830 - 3 Inducible and constitutive expression of resistance to glycopeptides and vancomycin dependence in glycopeptide-resistant Enterococcus avium; Rosato A et al.; A clinical isolate of Enterococcus avium, Ea1, which exhibited inducible, low-level resistance to vancomycin and teicoplanin, and two mutants selected from this strain, Ea3 and Ea31, were studied . Ea3 was vancomycin dependent and derived from Ea1, while Ea31 was not vancomycin dependent, was constitutively resistant, and was derived from Ea3 . Hybridization studies revealed that vanA was present in Ea1 and suggested that it was located on a high-molecular-weight plasmid . In the absence of induction, Ea1 synthesized only the natural UDP-MurNAc-pentapeptide precursor, and after induction it synthesized an additional precursor identified as UDP-MurNAc-tetrapeptide-D-lactate . The latter was the only precursor found in Ea3 and Ea31, even after precursor accumulation . From these results, we infer that (i) the low level of resistance to glycopeptides in strain Ea1 may be in part due to the residual synthesis of the normal precursor and (ii) the vancomycin dependence of mutant Ea3 could be due to the fact that this strain does not produce any peptidoglycan precursor in the absence of induction. J Bacteriol, 1995 Apr, 177(8), 2227 - 9 Potassium/proton antiport system of growing Enterococcus hirae at high pH; Kakinuma Y et al.; The cytoplasmic pH (pHin) of Enterococcus hirae growing at pH 9.2 was maintained at about 8.1 . Membrane-permeating amines such as ammonia alkalinized the pHin from 8.1 to 9.0 at a high concentration and induced K+ extrusion . The pHin alkalinization was transient; the pHin fell from 9.0 to the original value of pH 8.1, at which point K+ extrusion ceased, and remained constant . Cells accumulated ammonium ion to an extent stoichiometrically equivalent to the K+ loss . This bacterium continued to grow well under this condition . These results suggest that the pHin-responsive primary K+/H+ antiport system (Y . Kakinuma, and K . Igarashi, J . Biol . Chem . 263:14166-14170, 1988) works for the pHin regulation of this organism growing at a high pH. J Biol Chem, 1995 Mar 3, 270(9), 4349 - 54 Two trans-acting metalloregulatory proteins controlling expression of the copper-ATPases of Enterococcus hirae; Odermatt A et al.; Enterococcus hirae possesses two P-type ATPases, CopA and CopB, that are involved in copper homeostasis . These enzymes are induced by extracellular copper concentrations that are either too low or too high for optimal growth . To identify the regulatory proteins involved in induction, the DNA upstream of copA was cloned and sequenced . Following a putative promoter region, it contains two genes, copY and copZ, that encode proteins of 145 and 69 amino acids, respectively . Both proteins contain metal binding motifs and exhibit significant sequence similarity to known regulatory proteins . Gene disruption of copY by reverse genetics caused constitutive overexpression of CopA and CopB, generating a copper-dependent phenotype . In contrast, disruption of copZ suppressed the expression of the two copper-ATPases, rendering the cells copper-sensitive . Both null mutations could be complemented in trans with plasmids bearing copY or copZ . Thus, copY and copZ encode trans-acting metalloregulatory proteins that are required for induction of the cop operon by copper . In this mechanism, CopY apparently acts as a metal-fist type repressor and CopZ as an activator. Biochemistry, 1995 Feb 28, 34(8), 2455 - 63 Overexpression, purification, and characterization of VanX, a D-, D-dipeptidase which is essential for vancomycin resistance in Enterococcus faecium BM4147; Wu Z et al.; Vancomycin resistance in Enterococcus faecium requires five genes: vanR, vanS, vanH, vanA, and vanX . The functions and mechanism of four gene products have been known, with VanR/S for signal transduction and transcriptional regulation and VanH/A to synthesize D-Ala-D-lactate . But the function of the fifth gene product, VanX, has been unknown until very recently, when Reynolds and colleagues discovered D-, D-dipeptidase activity in crude extracts of a VanX overproducer {Reynolds, P . E., et al . (1994) Mol . Microbiol . 13, 1065-1070} . We report here the expression of VanX in Escherichia coli and its purification to homogeneity . VanX has been characterized as a metal-activated D-, D-dipeptidase with an optimal pH range of 7-9 . The kcat and Km of D-Ala-D-Ala in the absence of divalent metal are determined to be 4.7 s-1 and 1 mM, respectively . However, in the presence of metal cations, kcat can be as high as 788 s-1 . VanX is unable to hydrolyze D-Ala-D-lactate, the substituted moiety in the peptidoglycan that leads to vancomycin resistance, not only because of low binding affinity (Ki estimated at 242 mM) but also due to a kcat less than 0.005 s-1 . The more than 10(5)-fold differential in catalytic efficiency of VanX for hydrolysis of D-Ala-D-Ala vs D-Ala-D-lactate leaves D-Ala-D-lactate intact for subsequent incorporation into peptidoglycan.(ABSTRACT TRUNCATED AT 250 WORDS) Gene, 1995 Feb 27, 154(1), 87 - 92 The vanZ gene of Tn1546 from Enterococcus faecium BM4147 confers resistance to teicoplanin; Arthur M et al.; A five-gene cluster from Tn1546 confers resistance to the glycopeptide antibiotics vancomycin (Vm) and teicoplanin (Te) by synthesis of pentadepsipeptide peptidoglycan precursors terminating in D-lactate, which replaces D-alanine in the same position of precursors utilized by susceptible enterococci . Cloning and nucleotide sequencing indicated that Tn1546 contains an additional gene, designated vanZ, which confers low-level Te resistance, in the absence of the genes required for pentadepsipeptide synthesis . Analysis of cytoplasmic peptidoglycan precursors, accumulated in the presence of ramoplanin, showed that VanZ-mediated Te resistance does not involve incorporation of a substituent of D-alanine into the precursors. FEBS Lett, 1995 Feb 13, 359(2-3), 255 - 8 Electrogenic Na+ transport by Enterococcus hirae Na(+)-ATPase; Kakinuma Y et al.; Energy-dependent generation of a membrane potential (delta psi) (-45 mV, interior negative) was observed in the F0F1, H(+)-ATPase-defective mutant of Enterococcus hirae . The generation of delta psi was found at high pH (but not at low pH), for which intracellular Na+ was required but not extracellular K+ . The delta psi-generating activity was induced in cells cultured in media containing high concentrations of Na+, and was not observed in the Na(+)-ATPase mutants . These results suggest that E . hirae Na(+)-ATPase is responsible for the electrogenic sodium pump. J Pediatr Surg, 1995 Feb, 30(2), 173 - 8; discussion 178-81 Pediatric appendectomy; Pearl RH et al.; PURPOSE: To define patterns of care and outcome for pediatric appendectomy . METHODS: A study was designed to evaluate all pediatric appendectomies performed in the 147 Department of Defense hospitals worldwide . Cases of nonincidental appendectomy were identified through discharge diagnoses and operative logs, and 98.6% of the charts were retrieved for review . All charts were abstracted, and data were entered into a 127-field database for analysis . RESULTS: Over a 12-month period, ending January 1993, appendectomy was performed on 1,366 pediatric patients in the Department of Defense hospital system . The patients' median age was 12 years (range, 6 months to 18 years); 59% were male . The diagnosis was normal appendix for 157 patients (12%), acute nonperforated appendicitis for 930 (68%), and perforated appendicitis for 279 (20%) . Age < or = 8 years was predictive (P < .001) of a higher rate of perforated appendicitis (33% v 18%) but was not predictive of normal pathology (13% v 11%) . Female gender was associated with a significantly higher rate of normal pathology (17% v 8%; P < .001) but not of perforation (18% v 22%) . Temperature elevation and right lower quadrant pain and tenderness did not clinically distinguish between diagnostic groups . Sixty-two percent of patients with a normal appendix had a white blood cell count of more than 10,000/mm3, as did 91% of patients with acute or perforated appendicitis . Those with perforated appendicitis received pre- and postoperative antibiotics, primarily ampicillin/gentamicin/clindamycin or Flagyl (41%), cefoxitin (34%), or Unasyn (15%) . In 77% of this subgroup, intraoperative cultures were positive, with isolates for Escherichia coli (76%) Enterococcus (30%), Bacteroides (24%), and Pseudomonas (20%) predominating . There were no deaths . Major complications occurred in 1.2% of patients with acute appendicitis and in 6.4% of those with perforated appendicitis; there were no major complications in the group with normal appendectomies . The hospitalization period was more than 7 days for 1.6%, 40%, and 3.8%, respectively . CONCLUSION: This large series, from a large number of hospitals, with multiple practitioners, can serve as a community standard for pediatric appendectomy in the 1990s. Enferm Infecc Microbiol Clin, 1995 Feb, 13(2), 96 - 8 {False sensitivity of Enterococcus faecium to amoxicillin-clavulanic acid with the MicroScan system}; Joyanes P et al.; BACKGROUND: We have observed by using MicroScan automatic system discrepancies in susceptibility results of Enterococcus faecium strains to ampicillin and amoxicillin/clavulanic acid . METHODS AND RESULTS: Seventy-six strains of E . faecium were studied with MicroScan; 98.7% of them were inhibited by 16 mg/l of amoxycillin-clavulanic acid versus 60.5% inhibited by the same concentration of ampicillin . We have evaluated the susceptibility to ampicillin, amoxicillin and amoxicillin-clavulanic acid of 7 strains of E . faecium by both MicroScan and standard microdilution assay . MIC values of ampicillin were similar by both methods but MIC values of amoxicillin/clavulanic acid obtained by MicroScan (< or = 4/2 mg/l in 6 strains) were considerably lower than those obtained by standard microdilution (> or = 16/8 in 6 strains) . This phenomenon was not dependent of betalactamase production or bacterial inocula . CONCLUSIONS: When using MicroScan, E . faecium strains resistant to ampicillin (betalactamase non producers) must be also considered resistant to amoxicillin/clavulanic acid without considering the values obtained by this system. Diagn Microbiol Infect Dis, 1995 Feb, 21(2), 95 - 100 Emerging multiply resistant enterococci among clinical isolates . II . Validation of the etest to recognize glycopeptide-resistant strains; Jones RN et al.; Accurate, quantitative susceptibility testing of the enterococci for glycopeptide (vancomycin and teicoplanin) activity has become very important to guide chemotherapy as a result of emerging resistance . Reference dilution tests using broth and agar are generally difficult to perform, or in some commercial forms have demonstrated interpretive error . An alternative method, the Etest has promise as a system with qualitative and quantitative accuracy . Nearly 2000 enterococci from 97 laboratories in the United States were tested using broth microdilution, disk diffusion, and Etest methods . The Etest quantitative accuracy (+/- 1 log2 dilution) compared to the broth microdilution minimum inhibitory concentration was 90.1% (teicoplanin) to 94.1% (vancomycin) . The qualitative interpretive accuracy of the Etest ranged from 98.7% for vancomycin to 99.9% for teicoplanin (no false-susceptible errors) . All three tests were in remarkable agreement, with < or = 0.8% maximal discord by interpretive category . The Etest appears to be an excellent alternative to reference and standardized methods for producing quantitative activity measurements of glycopeptide susceptibility or resistance. Microb Drug Resist, 1995 Winter, 1(4), 335 - 9 In vitro activity of RP 59500 (quinupristin/dalfopristin) and ramoplanin against vancomycin-resistant Enterococcus faecium; Ristow TA et al.; Vancomycin-resistant Enterococcus faecium (VREF) collected between July 1991 and February 1994 were tested in vitro against RP 59500 and ramoplanin using agar dilution and standard macro broth dilution procedures . Colony counts were determined at 0, 4, and 24 h . RP 59500 had an MIC range of < or = 0.5-8 micrograms/ml with an MIC90 of 2 micrograms/ml and a MBC range of < or = 0.5-16 micrograms/ml with an MBC90 of 16 micrograms/ml . Ramoplanin had an MIC range of < or = 0.125-1 microgram/ml with an MBC range of < or = 0.125-4 micrograms/ml . The MIC90 for ramoplanin was 1 microgram/ml and the MBC90 was 4 micrograms/ml for the tested isolates . Against these isolates of E . faecium, RP 59500 was bactericidal at 8x MIC, a potentially achievable level using a high drug dosage . Ramoplanin was bactericidal at 2x MIC. Folia Microbiol (Praha), 1995, 40(6), 639 - 46 Hypocholesterolemic and immunostimulatory effects of orally applied Enterococcus faecium M-74 in man; Mikes A et al.; Lyophilized Enterococcus faecium M-74 was administered to 12 adult subjects in a daily oral dose of 5 x 10(9) bacteria for six weeks . The bacterium temporarily colonized the host intestine and its excretion with stool persisted for five weeks after the last does . The mean levels of serum cholesterol and LDL showed a a biphasic effect--an elevation followed by a sharp decrease (on day 64 of investigation) . The decrease corresponded in time with a significant increase in the ability to reduce iodonitrotetrazolium and superoxide production by peripheral neutrophils incubated with zymosan or phorbol myristate acetate, and also with an elevated production of IgG by peripheral blood mononuclear cells . Hence, intake of E . faecium may have a hypocholesterolemic and immunostimulatory effect . It was also demonstrated that E . faecium significantly reduced the average activity of beta-D-glucuronidase in stools. Scand J Infect Dis, 1995, 27(4), 401 - 3 Increased bactericidal activity as documented by serum bactericidal titers for a triple combination of cell wall active agents against gentamicin-resistant enterococci; Antony SJ et al.; Infections caused by entercocci have become increasingly difficult to treat because these bacteria are becoming increasingly resistant to commonly used antibiotics such as ampicillin, gentamicin and vancomycin . A consensus for an optimal therapy of enterococcal infections caused by resistant isolates has not yet been determined . We present a patient with prolonged enterococcal sepsis in whom a combination of ampicillin, vancomycin and imipenem was ultimately successful in suppressing enterococcal bacteremia . The enhanced activity of this triple combination was documented by the results of serial serum bactericidal titers. J Infect Dis, 1995 Jan, 171(1), 106 - 12 Comparison of different beta-lactam-glycopeptide-gentamicin combinations for an experimental endocarditis caused by a highly beta-lactam-resistant and highly glycopeptide-resistant isolate of Enterococcus faecium; Caron F et al.; A synergistic bactericidal effect between penicillin, vancomycin, and gentamicin has been described against enterococci highly resistant to beta-lactams and glycopeptides . Since such a synergy was also observed in vitro between ceftriaxone, teicoplanin, and gentamicin against Enterococcus faecium 70/90, the efficacy of different combinations including penicillin or ceftriaxone, vancomycin or teicoplanin, and gentamicin was compared in vivo in experimental endocarditis . In vitro, all four triple combinations provided a bactericidal effect . In rabbits, after a 5-day treatment, the ceftriaxone-vancomycin-gentamicin combination was the most effective, both in reducing the total bacterial titers and in eradicating the subpopulation resistant to the synergy . Compared with the 5-day regimen, 10- and 20-day regimens of ceftriaxone-vancomycin-gentamicin, each followed by a 3-day antibiotic-free period, increased the number of sterilized animals but failed to avoid the emergence of resistant bacteria, which occurred in 10%-20% of animals. Diagn Microbiol Infect Dis, 1995 Jan, 21(1), 47 - 50 In vitro antimicrobial susceptibility of glycopeptide-resistant enterococci; Freeman C et al.; The results of susceptibility testing of 48 phenotyped strains of glycopeptide antibiotic-resistant enterococci are reported . Minimum inhibitory and bactericidal concentrations (MICs and MBCs) were determined for 27 vanA, 17 vanB, and 4 vanC strains . Antibiotics exhibiting the greatest activity included novobiocin (MIC90 = 8 micrograms/ml and MBC90 = 32 micrograms/ml), ramoplanin (MIC90 = 2 micrograms/ml and MBC90 = 4 micrograms/ml), and the streptogramin RP59500 (MIC90 = 4 micrograms/ml and MBC90 = 32 micrograms/ml) . These antibiotics warrant further investigation as potentially useful agents, either alone or in combination, for treating enterococcal infections. Eur J Clin Microbiol Infect Dis, 1995, 14 Suppl 1, S33 - 7 Enterococci: susceptibility patterns and therapeutic options; Nicoletti G et al.; Enterococci do not possess the common virulence factors found in many other bacteria, but they have a number of other characteristics which make them particularly pathogenic . These organisms are intrinsically resistant to a number of antimicrobial agents, including beta-lactams (penicillins and cephalosporins), polymyxins and the lincosamides . They are also tolerant to the bactericidal activity of penicillins and glycopeptides, and some of the group have acquired resistance to a number of other clinically important antimicrobial agents including ampicillin, aminoglycosides, chloramphenicol and erythromycin . Numerous national and international studies have demonstrated the changes in the antibiotic resistance of enterococci . Many strains now exhibit multiple drug resistance, the most important being high-level resistance to streptomycin and gentamicin . Organisms exhibiting this high-level resistance are usually resistant to all synergistic combinations of beta-lactam antibiotics and aminoglycosides . Ampicillin-resistant strains are now emerging, some of which are beta-lactamase producers . While resistance to glycopeptides remains rare, it is increasing dramatically in many areas of the world . As nosocomial isolates of enterococci have displayed resistance to essentially every useful antimicrobial agent, it is likely to become increasingly difficult to treat and control enterococcal infections . The glycopeptide antibiotics vancomycin and, particularly, teicoplanin are the only alternatives currently available . Although a bactericidal combination of antibiotics appears necessary only in endocarditis and meningitis and although knowledge of the prevalence of resistant strains can be used to guide the selection of appropriate therapy, optimal regimens for the treatment of infections caused by multiresistant strains have yet to be determined.(ABSTRACT TRUNCATED AT 250 WORDS) J Clin Microbiol, 1995 Jan, 33(1), 215 - 6 Susceptibility to levofloxacin predicted from in vitro susceptibility testing results obtained with ciprofloxacin and with ofloxacin; Cormican MG et al.; A test battery of bacterial strains with a high incidence of resistance to fluoroquinolones was studied to determine the extent to which susceptibility to levofloxacin could be predicted from susceptibility tests performed with ciprofloxacin or ofloxacin as reagents . Isolates susceptible or intermediately susceptible to ofloxacin (MICs < or = 4 micrograms/ml) may be regarded as susceptible to levofloxacin, with the exception of Enterococcus faecium . Ciprofloxacin-susceptible isolates (MICs < or = 1 micrograms/ml) were also completely susceptible to levofloxacin . Clinical laboratories could use either of the currently used fluoroquinolones (ciprofloxacin or ofloxacin) to predict levofloxacin activity and spectrum with little risk of false-susceptible errors (0.0 to 1.3%) . Results obtained with ofloxacin are superior in maximizing recognition of levofloxacin-susceptible clinical isolates. J Infect Dis, 1994 Dec, 170(6), 1539 - 48 IS6770, an enterococcal insertion-like sequence useful for determining the clonal relationship of clinical enterococcal isolates; Thorisdottir AS et al.; Enterococci expressing resistance to antimicrobial agents are increasingly important nosocomial pathogens . Effective strategies to prevent or abort outbreaks of resistant enterococcal infection will rely on an accurate understanding of the mechanisms by which these organisms spread . A 1065-bp insertion-like sequence (IS6770) is present in varying copy numbers in > 90% of enterococcal strains thus far examined . Hybridization patterns resulting from hybridization of enterococcal genomic DNA with an internal IS6770 probe vary considerably between unrelated strains and correlate well with results of pulsed-field gel electrophoresis and field-inversion gel electrophoresis in identifying clonal relationships among enterococcal isolates . IS6770 analysis of several outbreaks of resistant enterococci has confirmed the spread of single resistant clones rather than the emergence of resistance within the resident flora . These results suggest that IS6770 hybridization will be a useful tool for tracing the epidemiology of nosocomial enterococcal infections. J Biochem (Tokyo), 1994 Dec, 116(6), 1302 - 8 Purification and characterization of the catalytic moiety of vacuolar-type Na(+)-ATPase from Enterococcus hirae; Kakinuma Y et al.; We have previously reported the molecular cloning and sequences of the ntp genes for Enterococcus hirae Na(+)-translocating ATPase {Takase, K., Kakinuma, S., Yamato, I., Konishi, K., Igarashi, K., and Kakinuma, Y . (1994) J . Biol . Chem . 269, 11037-11044}; the expected structure of this enzyme complex resembles those of the vacuolar H(+)-ATPase complexes in eukaryotes . In this paper we report purification and characterization of the catalytic moiety of Na(+)-ATPase, whose molecular size was about 400 kDa, consisting of polypeptides of 69 kDa (NtpA), 52 kDa (NtpB), and 29 kDa (NtpD) with a probable stoichiometry of 3:3:1 . Purified enzyme hydrolyzed GTP as the best substrate (GTP > CTP > UTP > ATP), and the activity was maximal at around pH 6.0 . The activity was not stimulated by sodium ions, and was selectively inhibited by nitrate . These properties were different from those of membrane-bound Na(+)-ATPase, suggesting that a significant conformational change of the catalytic moiety may take place upon dissociation from the membrane-embedded moiety and probably also loss of other hydrophilic subunits . Antiserum against purified enzyme inhibited the Na(+)-stimulated ATPase activity of the membranes . Immunoblotting analysis revealed that the change in the amounts of A and B subunits of the membranes paralleled that of the Na(+)-ATPase activity . Furthermore, the A subunit was missing in the membranes of a Na(+)-ATPase mutant, and recovered in those of its revertant . These immunochemical data are consistent with the notion that this enzyme is the hydrophilic catalytic moiety of the V-type Na(+)-ATPase in E . hirae. J Chemother, 1994 Dec, 6(6), 377 - 82 Observations on the tolerance and the paradoxical effect in enterococci; Puntorieri M et al.; Enterococci, already know to be relatively unaffected by several antibiotics due to their inheritant characteristics, are increasingly resistant to some very important groups of drugs, by means of acquisition or exchange of new genetic traits of resistance . Resistance or moderate susceptibility towards penicillin is an interesting characteristic of enterococci, whose low degree of susceptibility to this drug is due to a low affinity for penicillin-binding proteins (PBP) . Some strains of enterococci are not killed by the action of this drug but are "tolerant" (MIC/MBC > 32 mg/l) . This kind of "resistance", in which the probability of surviving under selective pressure of the drug is increased, is probably linked to the deficiency of the cell's autolytic system . Only rarely does another form of resistance called the "paradoxical effect" appear, in which higher numbers of cells survive at high concentrations than at lower concentrations . In our study the degree of bactericidal activity of some beta-lactams was considered . Our results demonstrate that: i) the paradoxical effect appears more in cultures in exponential phase compared to aged cultures; ii) mutated strains show an increased number of cells that respond paradoxically (the behavior is genetically determined); iii) different beta-lactams induced different degrees of autolysis. Cardiologia, 1994 Dec, 39(12 Suppl 1), 267 - 74 {Therapy and prevention of infective endocarditis}; Rocchi G et al.; Antibiotic therapy has improved infective endocarditis prognosis . The observance of general rules to choose the more suitable antibiotic drugs, as regard to their effectiveness, pharmacodynamic peculiarities and use, is mandatory . If the infection is due to antibiotic resistant microorganisms, microbiological analyses to estimate the bactericidal effect of the antibiotics, must be carried out . Resistance to penicillins, oligopeptides and aminoglycosides makes endocarditis produced by Enterococcus spp difficult to treat . The identification of patients at risk for infective endocarditis after surgical and invasive instrumental procedures, allows to introduce antibiotic prophylaxis regimens which can reduce the probability of acquiring the disease. Biochemistry, 1994 Nov 29, 33(47), 14115 - 20 Active-site labeling of an aminoglycoside antibiotic phosphotransferase (APH(3')-IIIa); McKay GA et al.; The aminoglycoside antibiotics are inactivated by modifying enzymes that are now widely distributed in many pathogenic bacteria . This situation threatens the continued use of these clinically important drugs . We have undertaken studies to understand the molecular mechanism of aminoglycoside resistance, and we report the affinity labeling of the enterococcal aminoglycoside 3'-phosphotransferase, APH(3')-IIIa, with an electrophilic ATP analogue, 5'-{p-(fluorosulfonyl)benzoyl}adenosine (FSBA) . Incubation of purified APH(3')-IIIa with FSBA resulted in time-dependent irreversible inactivation of enzyme activity with a binding constant, Ki, of 0.406 mM and a rate of maximal inactivation, kmax, of 0.086 min-1 . Addition of ATP completely protected the enzyme from inactivation, consistent with labeling of the ATP binding site . Reaction of APH(3')-IIIa with {14C}FSBA showed that inactivated APH(3')-IIIa incorporates 1 mol of FSBA/mol of enzyme . Peptide mapping of FSBA-inactivated APH(3')-IIIa resulted in the identification of two peptide peaks with highly increased absorbance at 260 nm, indicative of covalent labeling with FSBA . Analysis by electrospray ionization mass spectrometry and Edman degradation revealed two tryptic peptides, Val31-Lys44 and Leu34-Arg49, which incorporated the FSBA label at Lys33 and Lys44, respectively . This establishes the importance of the N-terminal region of APHs in ATP binding, a region of these enzymes which has heretofore not been considered for involvement in substrate binding. Plasmid, 1994 Nov, 32(3), 344 - 9 The prevalence of sequences homologous to IS256 in clinical enterococcal isolates; Rice LB et al.; Using dot blot hybridization techniques and an internal IS256 probe, we screened 103 clinical enterococcal isolates for the presence of sequences homologous to IS256 . Most screened isolates exhibited resistance to one or more antimicrobial agents . Overall, hybridization to the internal IS256 probe was demonstrable in 88/103 (85%) isolates . 49/53 (92%) gentamicin-resistant isolates hybridized with the IS256 probe . In addition, 34/45 (76%) gentamicin-susceptible, aph2"(-) strains possessed sequences homologous to IS256 . Southern hybridization experiments indicated that IS256 was frequently present in multiple copies in gentamicin-susceptible strains . These results suggest that IS256 is highly prevalent in clinical enterococcal isolates and that we may anticipate the emergence of novel, IS256-based composite mobile elements. Indian Pediatr, 1994 Nov, 31(11), 1357 - 61 Neonatal conjunctivitis: a profile; Verma M et al.; Neonatal conjunctivitis is one of the commonest infections encountered in the newborn . A prospective study was conducted on all babies born over a period of one year . No prophylactic ocular medication was instilled routinely in newborns . Babies developing purulent eye discharge were diagnosed to have conjunctivitis . Eye Swab from the neonates and maternal vaginal/cervical swabs were sent for culture . Chloromycetin eye drops were used for treatment and in case of no response, changed as per sensitivity report or to gentamicin eye drops . Oral erthromycin was given for dacryocystitis or when there was no response to topical therapy . The incidence of conjunctivitis was 7.2% . Two seasonal peaks, namely, February and then May and June, were noted . In 91.6% of the babies, conjunctivitis developed within the first week . A prolonged rupture of membranes was associated with a significantly higher incidence of conjunctivitis (p < 0.01) . The most common organism grown from conjunctival swab was Staph aureus (35.2%) followed by Enterococcus (4.3%), Klebsiella (3.5%) and E . coli (2.8%) . From vaginal/cervical swabs, E . coli was the most common organism isolated . No concurrence of organisms was noted between eye swabs and vaginal/cervical swabs . A uniformly good response to chloromycetin eye drops was noted with only 3.5% requiring a change of therapy . It is concluded that neonatal conjunctivitis is commonly acquired postnatally and responds well to topical chloromycetin therapy . Oral erythromycin may be used in resistant cases which will cover the chlamydial infection also. J Clin Microbiol, 1994 Nov, 32(11), 2840 - 2 Evaluation and characterization of multiresistant Enterococcus faecium from 12 U.S . medical centers; Sader HS et al.; Forty-two Enterococcus faecium isolates resistant to ampicillin, penicillin, gentamicin, streptomycin, vancomycin, and teicoplanin (VanA phenotype) from 12 U.S . medical centers were analyzed by pulsed-field gel electrophoresis of chromosomal DNA . The isolates were tested for susceptibility to 12 alternative drugs . The results indicated both intrahospital and interhospital diversity among multiresistant vanA enterococcal isolates . Furthermore, the finding of isolates with identical pulsed-field gel electrophoresis patterns in different centers strongly suggests some interhospital clonal transmission. J Clin Microbiol, 1994 Nov, 32(11), 2837 - 9 Simple test of synergy between ampicillin and vancomycin for resistant strains of Enterococcus faecium; Green M et al.; The combination of ampicillin and vancomycin kills some but not all strains of ampicillin- and vancomycin-resistant Enterococcus faecium . We compared a simple test for synergy utilizing a commercially available microdilution susceptibility system with time-kill studies and determined acceptable breakpoints for this test for 20 strains of ampicillin- and vancomycin-resistant E . faecium . The combination of ampicillin and vancomycin was tested for synergy by time-kill, broth macrodilution, and broth microdilution procedures . Repeat testing of isolates by macro- and microdilution synergy methods yielded MICs that were within one twofold dilution of each other for both intra- and intertest comparisons . Synergy was always detected by time-kill studies when the MIC of ampicillin in the combination synergy screen was < or = 8 micrograms/ml in the presence of vancomycin . No synergy was detected when the MIC was > 16 micrograms/ml in the combination microdilution synergy screen . The determination of the synergy by the broth microdilution procedure appears to be simple, convenient, and accurate. J Clin Microbiol, 1994 Nov, 32(11), 2671 - 6 Risk factors for acquiring ampicillin-resistant enterococci and clinical outcomes at a Canadian tertiary-care hospital; McCarthy AE et al.; The number of ampicillin-resistant enterococci (ARE) was noted to be increased at our teaching hospital . To determine the risk factors for acquiring this organism and to compare clinical outcomes, over a 5-month period 38 patients infected or colonized with ARE were compared with 76 patients, infected or colonized with ampicillin-susceptible enterococci (ASE) . Risk factors included nosocomial acquisition, duration of hospitalization, admission to a medical service, prior antimicrobial therapy, and combination therapy for at least 7 days . The mortality rate of patients infected or colonized with ARE was higher than that of patients infected or colonized with ASE (34 versus 14%; P = 0.03), but most deaths did not appear to be related to enterococcal infection . Over a 2-year period, 16 patients with ARE bacteremia were also compared with 23 patients with ASE bacteremia . The risk factors associated with ARE bacteremia also included nosocomial acquisition, duration of hospitalization, and prior antimicrobial therapy . The mortality of patients with ARE bacteremia was also higher than that of patients with ASE bacteremia (81 versus 30%; P = 0.003), with most deaths being due to the underlying disease or a complication of it . Typing of ARE isolates by pulsed-field gel electrophoresis showed that two genotypes predominated in our institution . A prolonged hospital stay, exposure to multiple antimicrobial agents, and perhaps nosocomial transmission are important factors in acquiring ARE . The presence of ARE may also be a marker for poor outcome. J Antimicrob Chemother, 1994 Nov, 34(5), 797 - 802 Treatment of experimental endocarditis due to multidrug resistant Enterococcus faecium with ciprofloxacin and novobiocin; Quale JM et al.; The effectiveness of ciprofloxacin and/or novobiocin therapy was assessed for experimental endocarditis caused by three strains of Enterococcus faecium resistant to ampicillin, vancomycin, and aminoglycosides . Rabbits with endocarditis caused by two of the strains had a significant decrease in bacterial counts in vegetations when treated with both antibiotics . Further studies using combination therapy with ciprofloxacin plus novobiocin for multidrug resistant strains of E . faecium are warranted. Drugs, 1994 Nov, 48(5), 678 - 88 Multidrug-resistant Enterococcus faecium . An untreatable nosocomial pathogen; Spera RV Jr et al.; The prevalence of enterococci and nosocomial pathogens has increased over the past 15 years . They have become increasingly resistant to agents traditionally useful in the treatment of invasive diseases due to enterococci . Vancomycin resistance, first described in clinical isolates in 1988, has disseminated worldwide . It is usually associated with high-level resistance to penicillins and aminoglycosides rendering the treatment of patients with vancomycin-resistant enterococci very difficult . Several investigators have reported mortality rates greater than 50% for vancomycin-resistant enterococcal bacteraemia . Risk factors associated with vancomycin-resistant enterococcal bacteraemia include prolonged hospital stay, neutropenia, prior oral or parenteral vancomycin use, and broad spectrum antibiotics . Since there is no uniformly effective antimicrobial therapy for patients infected with vancomycin-resistant enterococci, preventing of the spread of infection with the rigorous application of barrier precautions and other infectious control techniques is of paramount importance. Science, 1994 Oct 21, 266(5184), 439 - 43 Vancomycin resistance: structure of D-alanine:D-alanine ligase at 2.3 A resolution; Fan C et al.; The molecular structure of the D-alanine:D-alanine ligase of the ddlB gene of Escherichia coli, co-crystallized with an S,R-methylphosphinate and adenosine triphosphate, was determined by x-ray diffraction to a resolution of 2.3 angstroms . A catalytic mechanism for the ligation of two D-alanine substrates is proposed in which a helix dipole and a hydrogen-bonded triad of tyrosine, serine, and glutamic acid assist binding and deprotonation steps . From sequence comparison, it is proposed that a different triad exists in a recently discovered D-alanine:D-lactate ligase (VanA) present in vancomycin-resistant enterococci . A molecular mechanism for the altered specificity of VanA is suggested. J Appl Bacteriol, 1994 Oct, 77(4), 362 - 9 Characterization and identification of Vagococcus fluvialis strains isolated from domestic animals; Pot B et al.; Strains of Vagococcus fluvialis, a species of Gram-positive catalase-negative cocci, related to the genera Enterococcus and Carnobacterium, were isolated from various lesions of pigs, from lesions and tonsils of cattle and cats and from tonsils of a horse . Most lesion strains were isolated in mixed culture from animals with disease conditions unrelated to coccal infection . Certain differences with the species description of Vagococcus fluvialis were found: only a proportion of the strains was motile; many strains gave positive reactions to Voges-Proskauer, alkaline phosphatase and leucine arylamidase tests or produced acid from galactose and D-tagatose . SDS-PAGE of whole-cell protein patterns, however, confirmed the phenotypic identification . Guidelines for identification of Vagococcus fluvialis are given and an emended description of the species is proposed. J Bacteriol, 1994 Oct, 176(20), 6334 - 9 Determination of the gene sequence and the molecular structure of the enterococcal peptide antibiotic AS-48; Martinez-Bueno M et al.; The structural gene of the enterococcal peptide antibiotic AS-48 (as-48) has been identified and cloned by using two degenerate 17-mer DNA oligonucleotides on the basis of the amino acid sequences of two peptides obtained by digestion of the antibiotic with Glu-C endoproteinase . That as-48 gene codes for a 105-amino-acid prepeptide, giving rise to a 70-amino-acid mature protein . Comparative analysis demonstrated that the 16-amino-acid sequence of one of the AS-48 Glu-C peptides, designated V8-5, was composed of a 12-amino-acid sequence corresponding to the C-terminal end sequence (from isoleucine +59 to tryptophan +70 {I+59 to W+70}) of the prepeptide and terminated in four residues forming the N terminus (M+1 to E+4) of a putative AS-48 propeptide . These data, combined with the characteristics of the gene sequence, strongly suggested that the antibiotic peptide was a 70-residue cyclic molecule . We propose that the AS-48 translated primary product is very likely submitted to a posttranslational modification during secretion (i) by an atypical or a typical signal peptidase that cleaves off a 35-residue or shorter signal peptide, respectively, from the prepeptide molecule and (ii) by the linkage of the methionine residue (M+1) to the C-terminal tryptophan residue (W+70) to obtain the cyclic peptide (a tail-head linkage). J Bacteriol, 1994 Oct, 176(19), 6131 - 3 Involvement of folic acid and methionine in the synthesis of certain membrane-associated nucleotide sugars by Enterococcus hirae; Wood RC; A membrane preparation from Enterococcus hirae contained UDP and methyl-UDP (mUDP) monosaccharides . This preparation, when incubated with combinations of folic acid, L-serine, and S-adenosyl-L-methionine in a reaction system containing UDP-glucose, promoted synthesis of certain mUDP sugars . Folic acid and serine produced mUDP-glucose and mUDP-rhamnose; S-adenosylmethionine produced mUDP-glucose, mUDP-mannose, and mUDP-fucose. Diagn Microbiol Infect Dis, 1994 Oct, 20(2), 113 - 6 Detection of vancomycin resistance in enterococci by the Vitek AMS system; Zabransky RJ et al.; The ability of the Vitek AMS system to detect vancomycin resistance in enterococci was evaluated by comparing the results to an agar dilution screen method . Of 100 strains tested, 43 were resistant and 51 were susceptible by both tests . Two strains were intermediate by Vitek but susceptible by agar screen, one was intermediate by Vitek but resistant by agar screen, and four were susceptible by Vitek but resistant by agar screen . When the Vitek intermediate and resistant results were combined, the false resistant rate was 4.4% and false susceptible rate was 8.5% . In its current format, the Vitek system appears not to have acceptable accuracy for the detection of vancomycin resistance in enterococci. Proc Natl Acad Sci U S A, 1994 Sep 27, 91(20), 9651 - 4 P-type ATPase from the cyanobacterium Synechococcus 7942 related to the human Menkes and Wilson disease gene products; Phung LT et al.; DNA encoding a P-type ATPase was cloned from the cyanobacterium Synechococcus 7942 . The cloned ctaA gene encodes a 790-amino acid polypeptide related to the CopA Cu(2+)-uptake ATPase of Enterococcus hirae, to other known P-type ATPases, and to the candidate gene products for the human diseases of copper metabolism, Menkes disease and Wilson disease . Disruption of the single chromosomal gene in Synechococcus 7942 by insertion of an antibiotic-resistance cassette results in a mutant cell line with increased tolerance to Cu2+ compared with the wild type. Microbiol Res, 1994 Sep, 149(3), 247 - 51 The effect of some antibiotics on Enterococcus faecium SF 68 inoculated in germ-free mice; Trovatelli LD et al.; A strain of Enterococcus faecium SF 68 (sensitive to penicillin, tetracycline, virginiamicin and tylosin, but resistant to streptomycin) was administered to five groups of germ-free mice . Each group was subsequently given 40 micrograms/ml and then 80 micrograms/ml of a single antibiotic . The following determinations were made: a) colonization of the bacterial strain before and after administration of the antibiotic and b) the MICs in the original strain and after administration of the antibiotic (80 micrograms Iml) . The results show that in the mice treated with streptomycin, colonization is not influenced by the antibiotic treatment; in mice treated with antibiotics to which the strain is sensitive, the colonization increases in proportion to the level of the antibiotic resistance (tylosin and tetracycline). Diagn Microbiol Infect Dis, 1994 Sep, 20(1), 41 - 3 An old antibiotic for a new multiple-resistant Enterococcus faecium? Moreno F, Jorgensen JH, Weiner MH. Enterococci have become an important cause of nosocomial infections and may demonstrate high-level resistance to multiple antibiotics . We present the case of a 68-year-old man with a history of small cell lung cancer, who developed bacteremia due to a strain of Enterococcus faecium . The isolate was resistant to multiple antibiotics including vancomycin, ampicillin, aminoglycosides, quinolones, and macrolides . The patient was successfully treated with doxycycline and removal of an infected central venous catheter. Environ Health Perspect, 1994 Sep, 102 Suppl 3, 107 - 13 Newer systems for bacterial resistances to toxic heavy metals; Silver S et al.; Bacterial plasmids contain specific genes for resistances to toxic heavy metal ions including Ag+, AsO2-, AsO4(3-), Cd2+, Co2+, CrO4(2-), Cu2+, Hg2+, Ni2+, Pb2+, Sb3+, and Zn2+ . Recent progress with plasmid copper-resistance systems in Escherichia coli and Pseudomonas syringae show a system of four gene products, an inner membrane protein (PcoD), an outer membrane protein (PcoB), and two periplasmic Cu(2+)-binding proteins (PcoA and PcoC) . Synthesis of this system is governed by two regulatory proteins (the membrane sensor PcoS and the soluble responder PcoR, probably a DNA-binding protein), homologous to other bacterial two-component regulatory systems . Chromosomally encoded Cu2+ P-type ATPases have recently been recognized in Enterococcus hirae and these are closely homologous to the bacterial cadmium efflux ATPase and the human copper-deficiency disease Menkes gene product . The Cd(2+)-efflux ATPase of gram-positive bacteria is a large P-type ATPase, homologous to the muscle Ca2+ ATPase and the Na+/K+ ATPases of animals . The arsenic-resistance system of gram-negative bacteria functions as an oxyanion efflux ATPase for arsenite and presumably antimonite . However, the structure of the arsenic ATPase is fundamentally different from that of P-type ATPases . The absence of the arsA gene (for the ATPase subunit) in gram-positive bacteria raises questions of energy-coupling for arsenite efflux . The ArsC protein product of the arsenic-resistance operons of both gram-positive and gram-negative bacteria is an intracellular enzyme that reduces arsenate {As(V)} to arsenite {As(III)}, the substrate for the transport pump . Newly studied cation efflux systems for Cd2+, Zn2+, and Co2+ (Czc) or Co2+ and Ni2+ resistance (Cnr) lack ATPase motifs in their predicted polypeptide sequences . Therefore, not all plasmid-resistance systems that function through toxic ion efflux are ATPases . The first well-defined bacterial metallothionein was found in the cyanobacterium Synechococcus . Bacterial metallothionein is encoded by the smtA gene and contains 56 amino acids, including nine cysteine residues (fewer than animal metallothioneins) . The synthesis of Synechococcus metallothionein is regulated by a repressor protein, the product of the adjacent but separately transcribed smtB gene . Regulation of metallothionein synthesis occurs at different levels; quickly by derepression of repressor activity, or over a longer time by deletion of the repressor gene at fixed positions and by amplification of the metallothionein DNA region leading to multiple copies of the gene. Yeast, 1994 Sep, 10(9), 1217 - 25 A putative P-type Cu(2+)-transporting ATPase gene on chromosome II of Saccharomyces cerevisiae; Rad MR et al.; We have sequenced a gene on the right arm near the telomere of chromosome II of Saccharomyces cerevisiae which codes for a putative P-type cation-transporting ATPase (PCA1) . The gene codes for a 1216 amino acids protein . The PCA1 gene expresses a 3.5 kb message in both haploid and diploid cells when grown in glucose-based rich medium YPD . The gene product is most similar at the C-terminal region to a human copper-transporting ATPase and Enterococcus hirae copper-transporting ATPases and also an N-terminal dithiol region that was proposed to be a 'metal-binding motif' . Cells lacking PCA1 display no obvious phenotype when tested under standard conditions: whereas they cease growth much earlier than the isogenic wild-type cells in a minimal medium with high copper concentration . Overexpression of PCA1 under GAL1/10 promoter in yeast cells causes poor growth . We also show that yeast strains carrying PCA1 in multiple copies grow slower than isogenic wild-type strains in a minimal synthetic medium containing 0.3 mM-CuSO4. Contemp Intern Med, 1994 Sep, 6(9), 7 - 17 Confronting antibiotic resistance in enterococcal infections; Hayden MK et al.; The increase in enterococcal infections, particularly nosocomial, and the resistance of many species to multiple antibiotics challenge treatment decisions . Resistance screening and synergistic combinations of antimicrobials may be effective. Am J Infect Control, 1994 Aug, 22(4), 202 - 6 Colonization pattern of vancomycin-resistant Enterococcus faecium; Yamaguchi E et al.; BACKGROUND: Vancomycin-resistant Enterococcus faecium is increasingly recognized as a serious problem by hospital epidemiologists . Understanding its colonization patterns may help in designing strategies to control its nosocomial spread in the hospital . METHODS: Twenty patients, selected at random, with vancomycin-resistant E . faecium isolated from cultures of various body sites were studied to determine sites of colonization . For 12 of these patients, cultures of environmental surfaces of their rooms and wards were also obtained . RESULTS: Eighteen patients (90%) had vancomycin-resistant E . faecium grown in stool cultures . In five patients (25%), vancomycin-resistant E . faecium was cultured from other sites: groins (four), popliteal fossae (three), mouth (one), and an open wound site (one) . Patients with positive cultures from the groins and popliteal fossae also had growth of vancomycin-resistant E . faecium in cultures of diarrhea soiling those sites . No patients had the organism isolated from their nares . Vancomycin-resistant E . faecium grew in cultures obtained from bedside stand tables, over-bed tables, used linen, and bedside rails . CONCLUSIONS: In the 20 patients studied, colonization of vancomycin-resistant E . faecium was limited chiefly to the enteric tract . Absence of colonization of such a secluded area with poor antibiotic penetrability as the nares is encouraging . In our study, vancomycin-resistant E . faecium was isolated from various environmental surfaces from the rooms and wards of patients with vancomycin-resistant E . faecium in their stools. Zentralbl Hyg Umweltmed, 1994 Aug, 196(2), 181 - 96 {Further studies on the falsification of the steam resistance of bioindicators by superheating}; Spicher G et al.; As a supplement to a preceding paper (Zbl . Hyg., 194 (1993) . 369-279) the resistance of bioindicators has been investigated which differed only in the material of which the carriers are made (filter paper and glass fibre fleece, respectively) . The conditions of the tests were such that further evidence could be expected for the fact that the characteristic values of bioindicators can be falsified by superheating of the carrier and its envelope . As a test organism Enterococcus faecium has been used . To avoid side effects, the bacteria have been dried on to the carriers from a suspension in water distillators . The exposition basket of the resistometer has been loaded with 3 rows of 15 indicators (disc shaped; diameter: 6 mm), arranged parallel . At a temperature of 68 degrees C the dependency of (relative) frequency of indicators having surviving test organisms capable of multiplying on exposure time to saturated steam has been determined . Free exposed indicators made of filter paper required considerably longer exposure periods than indicators made of glass fibre fleece to change from "(nearly) all the indicators have test organisms capable of multiplying" to "(nearly) all the indicators are free from test organisms capable of multiplying" . The exposure time to free 50% of carriers made of filter paper from test organisms capable of multiplying (t50%) amounted to 44.1 minutes . The frequency of indicators free from test organisms was higher at the ends than in the middle of the exposed rows . When such indicators had been wetted before exposure, they showed a t50% value of 2.3 minutes, and the frequency of indicators free from surviving test organisms was distributed over the exposed indicators evenly . Free exposed indicators made of glass fibre fleece showed a t50% value of 4.4 minutes . The frequency of indicators free from test organisms was evenly distributed . Wetting of the indicators before exposure changed t50% value only slightly . When indicators made of glass fibre fleece had been exposed between two layers of filter paper they showed a very high t50% value (47.5 minutes), and the frequency of indicators free from test organisms was unevenly distributed . Indicators being sterile could be found mainly at the ends of the exposed rows . In an envelope of parchment paper bioindicators made of glass fibre fleece showed considerably higher characteristic values than when free exposed . Superheating of the carriers amounted to about 3 Kelvin.(ABSTRACT TRUNCATED AT 400 WORDS) Biochem Biophys Res Commun, 1994 Jul 15, 202(1), 44 - 8 Induction of the putative copper ATPases, CopA and CopB, of Enterococcus hirae by Ag+ and Cu2+, and Ag+ extrusion by CopB; Odermatt A et al.; The two P-type ATPases CopA and CopB are effecting regulation of cellular copper activity in Enterococcus hirae . With antibodies against these ATPases, we showed on Western blots the simultaneous induction of CopA and CopB by copper or silver ions . Copper contents of wild type and mutant cells lacking either CopA, CopB or both enzymes were measured by atomic absorption . Strains disrupted in copB showed clearly enhanced copper contents . Mutants lacking CopB also lost the ability of energy dependent efflux of silver ions . Our results demonstrate that CopA and CopB are under the same genetic control and support the proposal that CopB is a copper and silver exporting ATPase. FEMS Microbiol Lett, 1994 Jul 15, 120(3), 307 - 13 Ribosomal RNA gene (rrn) organization in enterococci; Sechi LA et al.; A cloned 1.8-kb probe containing the 3' end of 16S ribosomal RNA and the 5' end of 23S ribosomal RNA from Enterococcus hirae was used to analyze various endonuclease digests of enterococci . In the ATCC strains tested we observed a remarkable conservation of the ApaI sites in the rrn operons, and a partial conservation of EcoRI sites . Using a number of other endonuclease digestions with the ApaI rrn probe, we estimate the number of rrn operons in enterococci to be between five and six. FEMS Microbiol Lett, 1994 Jul 1, 120(1-2), 119 - 23 Characteristics of an ethidium efflux system in Enterococcus hirae; Midgley M; An energy-dependent efflux system for ethidium and related cations has been detected in Enterococcus hirae ATCC 9790 . The system was partially expressed when the organism was grown on a complex medium but was induced by the addition of phosphonium ions and related compounds . Mutants showing constitutive expression of the efflux system have been isolated on the basis of increased resistance to ethidium. Biochem J, 1994 Jul 1, 301 ( Pt 1), 5 - 8 Analysis of peptidoglycan precursors in vancomycin-resistant Enterococcus gallinarum BM4174; Reynolds PE et al.; Vancomycin resistance in enterococci is an increasing clinical problem, and several phenotypes have been identified . We demonstrate here that the resistance mechanism in the constitutively vancomycin-resistant Enterococcus gallinarum BM4174 involves an altered pathway of peptidoglycan synthesis and hydrolysis of the normal precursors in the vancomycin-sensitive pathway . A ligase encoded by the vanC gene catalyses synthesis of D-Ala-D-Ser and substitutes this dipeptide for D-Ala-D-Ala in peptidoglycan precursors . It is presumed that this substitution lowers the affinity of vancomycin for its target site . Destruction of D-Ala-D-Ala (D,D-peptidase activity) and of UDP-MurNAc-L-Ala-D-isoGlu-L-Lys-D-Ala-D-Ala by removal of the terminal D-Ala residue (D,D-carboxypeptidase activity) ensures that the normal vancomycin-sensitive pathway of peptidoglycan synthesis cannot function in the resistant strain. Antimicrob Agents Chemother, 1994 Jul, 38(7), 1675 - 7 Emergence of high-level resistance to glycopeptides in Enterococcus gallinarum and Enterococcus casseliflavus; Dutka-Malen S et al.; Enterococcus gallinarum BM4231 and Enterococcus casseliflavus BM4232, isolated from the feces of a patient under oral therapy with vancomycin, were resistant to high levels of vancomycin (MICs of > 256 micrograms/ml) and teicoplanin (MICs of 128 and 64 micrograms/ml, respectively) . This phenotype is new for these bacterial species that are naturally resistant to low levels of vancomycin and appears to be due to in vivo acquisition of plasmid pIP218 carrying the vanA gene cluster. Antimicrob Agents Chemother, 1994 Jul, 38(7), 1668 - 70 Activity of clinafloxacin against multidrug-resistant Enterococcus faecium; Burney S et al.; Enterococci resistant to ampicillin, vancomycin, and/or aminoglycosides are a growing clinical problem . We studied the in vitro activity of the new fluoroquinolone clinafloxacin (PD 127,391) against 15 clinical isolates of multidrug-resistant Enterococcus faecium . In kill-kinetic studies, clinafloxacin (1 microgram/ml) was bactericidal against 7 of 12 susceptible isolates, although substantial regrowth occurred in 4 isolates at 48 h . The addition of ampicillin (20 micrograms/ml) resulted in bactericidal activity in all 12 isolates, and no regrowth was seen . For three isolates resistant to clinafloxacin, effective killing was not observed at these concentrations of antibiotics . Clinafloxacin with ampicillin shows promising activity against many of these multiply resistant enterococci. J Hosp Infect, 1994 Jul, 27(3), 187 - 93 Nosocomial infection due to enterococci attributed to a fluidized microsphere bed . The value of pyrolysis mass spectrometry; Freeman R et al.; The potential of fluidised microsphere beds as sources of nosocomial Enterococcal infection was investigated with the help of pyrolysis mass spectrometry . Isolates from clinical specimens collected from two patients who were nursed sequentially on a fluidized microsphere bed were compared with similar isolates cultured from the microspheres before and after decontamination . Pyrolysis mass spectrometry confirmed that nosocomial spread had indeed occurred and that the existing decontamination process was inadequate . Recommendations for improvements to this decontamination process appear to have prevented further cases. J Hosp Infect, 1994 Jul, 27(3), 179 - 86 Enterococcal bacteraemia: a prospective study of 125 episodes; Gray J et al.; One hundred and twenty-five episodes of enterococcal bacteraemia occurring over a 50-month period were studied prospectively . Enterococcus faecium was the commonest species, accounting for 76 (59.8%) of the 127 isolates . Overall, 33.1% of isolates were resistant to ampicillin and one isolate (0.8%) to vancomycin; high-level gentamicin resistance was detected in 4.3% of 93 isolates tested . The percentage of nosocomial episodes was 70.4, and 95.2% of the patients had significant underlying illness . Central venous catheters (CVCs) were the commonest source of infection . Eighty-four per cent of episodes were ultimately treated with appropriate antibiotics . The overall mortality rate was 17.6%, and that directly attributable to infection was 8.0% . An increased mortality rate was observed in intensive care and neonatal unit patients, and in patients who had received antimicrobial therapy in the 2 weeks prior to enterococcemia . CVC-related infections were associated with a reduced mortality . No other clinical or microbiological factors were found to influence outcome. Clin Infect Dis, 1994 Jul, 19(1), 163 - 5 Successful treatment of meningitis due to multiply resistant Enterococcus faecium with a combination of intrathecal teicoplanin and intravenous antimicrobial agents; Losonsky GA et al.; Following neurosurgery necessitated by intractable seizures, Enterococcus faecium meningitis that was resistant to ampicillin, a high-level aminoglycoside (MIC, > 2,000 micrograms/mL), and vancomycin developed in a 6-year-old boy . Treatment with intrathecal teicoplanin in combination with intravenous clindamycin, rifampin, and ampicillin was successful . The role of intravenous and intrathecal antibiotics in treatment of this infection is discussed . This case is illustrative of the safety and potential usefulness of intrathecally administered teicoplanin. J Clin Microbiol, 1994 Jul, 32(7), 1700 - 4 Development of a standardized screening method for detection of vancomycin-resistant enterococci; Swenson JM et al.; The incidence of vancomycin resistance among enterococci is increasing in the United States and elsewhere in the world, but automated susceptibility testing methods have difficulty detecting resistance expressed by certain strains . The agar screening method described by Willey et al . (B . M . Willey, B . N . Kreiswirth, A . E . Simor, G . Williams, S . R . Scriver, A . Phillips, and D . E . Low, J . Clin . Microbiol . 30:1621-1624, 1992) has been proposed as a reliable method for confirming vancomycin resistance . In this study, we investigated various parameters associated with the agar screening method and, on the basis of the findings, established optimum testing conditions for the method . First, to evaluate media and vancomycin concentrations, one laboratory used Mueller-Hinton and brain heart infusion agars supplemented with 4, 6, and 8 micrograms of vancomycin per ml to test 100 genetically characterized enterococcal strains . On the basis of the results obtained, brain heart infusion agar supplemented with 6 micrograms of vancomycin per ml was selected for further study . Subsequently, eight laboratories used the medium to test both reference and clinical isolates . There was very good performance with the reference strains and, among 158 clinical isolates tested, the method demonstrated sensitivity and specificity of 100% and from 96 to 99%, respectively. Lett Appl Microbiol, 1994 Jul, 19(1), 12 - 5 Influence of pH on the production of enterocin 1146 during batch fermentation; Parente E et al.; The production of enterocin 1146, a bacteriocin from Enterococcus faecium DPC1146, was studied during batch fermentation at pH 5, 5.5, 6 and 6.5 . The bacteriocin was produced throughout the growth of the micro-organism, showing primary metabolite kinetics . Bacteriocin production stopped at the end of growth and was followed by a decrease in activity due primarily to adsorption on the cells of the producer . The optimal pH for enterocin 1146 production was 5.5, because of higher bacteriocin yield per unit of biomass and slower adsorption/degradation, while optimal pH for growth was between 6.0 and 6.5. FEMS Microbiol Lett, 1994 Jun 15, 119(3), 359 - 63 Conjugal transfer of the vancomycin resistance determinant vanB between enterococci involves the movement of large genetic elements from chromosome to chromosome; Quintiliani R Jr et al.; Resistance to various levels of vancomycin and susceptibility to teicoplanin in enterococci (VanB phenotype) is mediated by the vanB gene cluster . VanB-type resistance was transferred by intra- and inter-specific conjugation between different strains of Enterococcus . Analysis of SfiI-digested genomic DNA by zero integrated-field electrophoresis followed by Southern hybridization revealed vanB-containing chromosomal insertions of approximately 90-250 kb in the transconjugants . Thus, transfer of VanB-type resistance is associated with the movement of large genetic elements from chromosome to chromosome. Biochemistry, 1994 Jun 7, 33(22), 6936 - 44 Broad spectrum aminoglycoside phosphotransferase type III from Enterococcus: overexpression, purification, and substrate specificity; McKay GA et al.; The aminoglycoside phosphotransferases (APHs) are responsible for the bacterial inactivation of many clinically useful aminoglycoside antibiotics . We report the characterization of an enterococcal enzyme, APH(3')-IIIa, which inactivates a broad spectrum of aminoglycosides by ATP-dependent O-phosphorylation . Overproduction of APH(3')-IIIa has permitted the isolation of 30-40 mg of pure protein/(L of cell culture) . Purified APH(3')-IIIa is a mixture of monomer and dimer which is slowly converted to dimer only over time . Dimer could be dissociated into monomer by incubation with 2-mercaptoethanol, suggesting that dimerization is mediated by formation of disulfide bond(s) . Both monomer and dimer show Km values in the low micromolar range for good substrates such as kanamycin and neomycin, and kcat values of 1-4 s-1 . All aminoglycosides show substrate inhibition except amikacin and kanamycin B . Determination of minimum inhibitory concentrations indicates a positive correlation between antibiotic activity and kcat/Km, but not with Km or kcat . NMR analysis of phosphorylated kanamycin A has directly demonstrated regiospecific phosphoryl transfer to the 3'-hydroxyl of the 6-aminohexose ring of the antibiotic . Analysis of structure-activity relationships with a variety of aminoglycosides has revealed that the deoxystreptamine aminocyclitol ring plays a critical role in substrate binding . This information will form the basis for future design of inhibitors of APH(3')-IIIa. FEBS Lett, 1994 Jun 6, 346(1), 44 - 7 Copper pumping ATPases: common concepts in bacteria and man; Solioz M et al.; Recently, four genes encoding putative copper pumping ATPases have been cloned from widely different sources: two genes from Enterococcus hirae that are involved in copper metabolism and two human genes that are defective in the copper-related Wilson and Menkes disease . The predicted gene products are P-type ATPases . They exhibit extensive sequence similarity and appear to be members of a new class of ATP driven copper pumps involved in the regulation of cellular copper. Antimicrob Agents Chemother, 1994 Jun, 38(6), 1363 - 7 Outbreak of vancomycin-, ampicillin-, and aminoglycoside-resistant Enterococcus faecium bacteremia in an adult oncology unit; Montecalvo MA et al.; An outbreak of bacteremia caused by Enterococcus faecium with high-level resistance to vancomycin (MIC of > or = 256 micrograms/ml), ampicillin (MIC of > or = 64 micrograms/ml), and gentamicin or streptomycin (MIC of > or = 2,000 micrograms/ml) occurred in an adult oncology unit from June 1991 to May 1992 . Active surveillance for the presence of this organism in stool or perianal cultures was begun in September 1991 . Between June 1991 and May 1992, seven patients with bacteremia and 22 noninfected carriers of the organism in stool were identified . The vanA gene, tested for by PCR and gene probe, was present in all isolates evaluated . All bacteremic patients also had resistant E . faecium present in a stool or perianal culture; the stool isolates tested were closely related to the respective blood isolates as determined by pulsed-field gel electrophoresis . Antibiotic regimens using high-dose ampicillin and an aminoglycoside were ineffective with four patients . Five patients (71%) had multiple positive blood cultures; four of these patients died . Following a multiple logistic regression analysis, it was found that bacteremic patients received a significantly greater number of total antibiotic days compared with noninfected stool carriers (P = 0.019) . The emergence of E . faecium with high-level resistance to vancomycin, ampicillin, and aminoglycosides underscores the importance of performing susceptibility testing on all clinically significant isolates . In the neutropenic adult oncology patient, bacteremia with this organism is of probable gastrointestinal origin, is often persistent, and is refractory to treatment with ampicillin in combination with an aminoglycoside . Prolonged use of antibiotics may predispose patients with gastrointestinal colonization to develop bacteremia. Antimicrob Agents Chemother, 1994 Jun, 38(6), 1225 - 9 Bactericidal activities of antibiotics against vancomycin-resistant Enterococcus faecium blood isolates and synergistic activities of combinations; Hayden MK et al.; The effects of teicoplanin (8 micrograms/ml), ampicillin (64 micrograms/ml), imipenem (32 micrograms/ml), and gentamicin (4 micrograms/ml), alone and in combination, against 13 unique blood isolates of vancomycin-resistance (MIC for 90% of isolates tested {MIC90}, 512 micrograms/ml), teicoplanin-susceptible (MIC90, 2.0 micrograms/ml), ampicillin-resistant (MIC90, 128 micrograms/ml), and non-beta-lactamase-producing Enterococcus facium (vancomycin-resistant enterococci {VRE} isolates) were evaluated by time-kill studies . All 13 isolates exhibited high-level resistance to streptomycin; 7 isolates exhibited high-level gentamicin resistance (HLGR) . After 24 h of incubation, ampicillin (64 micrograms/ml) combined with gentamicin (4 micrograms/ml) was bactericidal against three of the VRE isolates that did not display HLGR . Synergy between ampicillin and gentamicin was not observed against these isolates . Teicoplanin (8 micrograms/ml) alone was bactericidal at 24 h against five of six VRE isolates that lacked HLGR, but was not bactericidal against any HLGR VRE isolate at that time point . The addition of ampicillin (64 micrograms/ml) or imipenem (32 micrograms/ml) to teicoplanin did not significantly enhance the killing of HLGR VRE isolates as a group (P = 0.335) . However, there was a trend toward improved killing of some HLGR VRE isolates by teicoplanin plus imipenem . Vancomycin (32 micrograms/ml) combined with ampicillin (64 micrograms/ml) was neither bactericidal nor synergistic against HLGR VRE isolates . Overall, bactericidal activity was attainable against 7 of 13 VRE isolates at 24 h. Minerva Ginecol, 1994 Jun, 46(6), 337 - 41 {Antibiotic prophylaxis with cefotaxime in gynecological endoscopy}; Marchino GL et al.; It is now well known that even short operations of limited scope lower the body's defences by influencing the immune system . As a result this leads to a change in microbial flora which encourages an increase in the number of Gram-negative, aerobic, anaerobic and enterococcal colonies . In order to prevent infective postoperative complications which might occur after endoscopic surgery, the authors suggest using a series of valuable recommendations which are reported in this paper . Among these the most important is antibiotic prophylaxis which is able to limit the episodes of infection, thus making a positive contribution to the postoperative iter . Cefotaxime was chosen by the authors since this molecule offers both reliable and efficacious prophylaxis as has also been shown by other studies in the obstetrics and gynecological field . The results obtained by this study fully concord with data reported in the literature. Radiology, 1994 May, 191(2), 495 - 9 Bloodstream infections after interventional procedures in the biliary tract; Clark CD et al.; PURPOSE: To assess the adequacy of prophylaxis for interventional radiologic biliary procedures and the etiologic organisms of subsequent bloodstream infections . MATERIALS AND METHODS: Data from 148 patients who underwent 480 interventional radiologic biliary procedures were evaluated for evidence of bloodstream infection . Data analyzed included type of procedure performed, whether an antibiotic was used, and evidence of infectious complications occurring during and within 72 hours after the procedure . All culture data obtained before and after the procedure were recorded . RESULTS: Seven cases of new bloodstream infection were identified, five of which were caused by Enterococcus species . No substantial risk factors for bloodstream infection were identified, although it occurred only in patients who had recently undergone biliary surgery or underwent manipulations other than simple cholangiography . Microbial colonization of the bile was associated with older age . Evidence of possible or proved infection after the first interventional procedure was more common in patients with positive bile cultures . CONCLUSION: Although the importance of enterococcal bacteremia is uncertain, current recommendations for cephalosporin prophylaxis for interventional radiologic biliary procedures should be reevaluated. Res Vet Sci, 1994 May, 56(3), 397 - 8 Pathogenicity of Enterococcus hirae for chicken embryos and betamethasone-treated chicks; Abdul-Aziz TA et al.; An isolate Enterococcus hirae was used to determine its pathogenicity for chicken embryos and for chicks treated with betamethasone . E hirae was inoculated intravenously into four-day-old chicks which had been treated for three consecutive days with betamethasone, and chick embryos were inoculated into the allantoic cavity with 10(2) and 10(3) bacteria . E hirae was not pathogenic for the chicks or for the embryos. Plasmid, 1994 May, 31(3), 312 - 6 Studies on excision of conjugative transposons in enterococci: evidence for joint sequences composed of strands with unequal numbers of nucleotides; Rice LB et al.; We determined the nucleotide sequence of polymerase chain reaction products resulting from amplification of joint regions created after excision of transposons Tn5381 and Tn916 from a single site within plasmid pAD1 . For both transposons, two joint sequences were observed . One (ATAGAT) was six nucleotides in length and identical to one of the junction sequences flanking the integrated transposon . This sequence also represents the original target sequence within pAD1 . The other (TATGT (Tn5381) or TAGTT (Tn916)) was five nucleotides in length and identical to the junction sequence at the other end of the integrated transposons . These results suggest that excision of conjugative transposons from some insertion sites in gram-positive bacteria results in the formation of a joint region heteroduplex mismatched in nucleotide number as well as complementarity. J Burn Care Rehabil, 1994 May-Jun, 15(3), 236 - 9 Enterococcal infections as a cause of mortality and morbidity in patients with burns; Law EJ et al.; Enterococcal sepsis is a significant cause of death on our burn unit . In a 3-year period, enterococci were responsible for 11% to 13% of all infections . Bacteremias with enterococci ranged from 4.2% to 2.1% per year . Sixty-four percent of enterococcal bacteremias were polymicrobial . Septic deaths associated with enterococcal sepsis ranged from 20% to 10.3% . Antibiotic resistance to enterococci appears to be increasing. J Clin Microbiol, 1994 May, 32(5), 1148 - 53 Outbreak of multidrug-resistant Enterococcus faecium with transferable vanB class vancomycin resistance; Boyce JM et al.; Enterococcus faecium strains resistant to ampicillin, high levels of gentamicin, and vancomycin but susceptible to teicoplanin (vanB class vancomycin resistance) were recovered from 37 patients during an outbreak involving a 250-bed university-affiliated hospital . Three isolates with vancomycin MICs ranging from 8 to 256 micrograms/ml all hybridized with a vanB probe . Restriction endonuclease analysis of chromosomal and plasmid DNA suggested that all isolates tested were derived from a single clone . Vancomycin resistance was shown to be transferable . Risk factors for acquiring the epidemic strain included proximity to another case patient (P, 0.0005) and exposure to a nurse who cared for another case patient (P, 0.007) . Contamination of the environment by the epidemic strain occurred significantly more often when case patients had diarrhea (P, 0.001) . Placing patients in private rooms and requiring the use of gowns as well as gloves by personnel controlled the outbreak . These findings suggest that multidrug-resistant E . faecium strains with transferable vanB class vancomycin resistance will emerge as important nosocomial pathogens . Because extensive environmental contamination may occur when affected patients develop diarrhea, barrier precautions, including the use of both gowns and gloves, should be implemented as soon as these pathogens are encountered. Diagn Microbiol Infect Dis, 1994 May, 19(1), 57 - 60 Bactericidal action of gentamicin against enterococci that are sensitive, or exhibit low- or high-level resistance to gentamicin; Fasola EL et al.; Treatment of serious enterococcal infection involves the use of penicillin-aminoglycoside combination therapy if the aminoglycoside minimum inhibitory concentration (MIC) is < or = 2000 micrograms/ml, and the organism is susceptible to penicillin or ampicillin . We evaluated killing of 15 enterococci that differ in their susceptibility to gentamicin using time-kill studies at different gentamicin concentrations . Sensitive strains had a uniform population killed by gentamicin concentrations equal to or above the MIC . Low-level resistant strains (MIC > or = 8 but < or = 2000 micrograms/ml of gentamicin) had a diverse population with large numbers of cells killed at one-half the MIC, while the highly resistant strains (MIC > 2000 micrograms/ml) showed no killing by any concentration of gentamicin. Biochemistry, 1994 Apr 19, 33(15), 4625 - 31 Identification of the DNA-binding site for the phosphorylated VanR protein required for vancomycin resistance in Enterococcus faecium; Holman TR et al.; The vancomycin resistance operon of Enterococcus faecium encodes a two-component regulatory system comprising VanS and VanR . In vitro experiments showed that about 5% of a labile phosphorylated VanR (P-VanR) was accumulated from ATP and a maltose-binding protein-VanS fusion protein (MBP-VanS) . Alternatively, about an 8% abundance of P-VanR was produced with acetyl phosphate . In such incubations, gel shift experiments revealed that P-VanR selectively bound to a 254-bp DNA fragment that contains the vanH promoter for the vanH, vanA, and vanX structural genes . When VanS was added with a mole ratio for VanS:VanR of higher than 1:1, VanS competed with DNA for P-VanR and abolished the gel shift . P-VanR bound 500-fold more tightly to the vanH promoter region, with an estimated EC50 of 40 nM, than the unphosphorylated VanR . A second DNA fragment of 197 bp containing the proposed vanR promoter for the vanR and vanS regulatory genes also exhibited gel shift, but with much lower affinities . A mutant VanR(D53A) was shown to be incompetent for phosphorylation by phosphorylated MBP-VanS or by acetyl phosphate; however, it still bound DNA specifically, albeit with low affinity . DNase I footprinting by P-VanR revealed that a ca . 80-bp region was protected on the vanH promoter and a ca . 40-bp region was protected on the vanR promoter . The unphosphorylated VanR footprinted the same 80 bp on the vanH promoter, but only 20 bp on the vanR promoter.(ABSTRACT TRUNCATED AT 250 WORDS) Int J Syst Bacteriol, 1994 Apr, 44(2), 365 - 7 Evidence for a close phylogenetic relationship between Melissococcus pluton, the causative agent of European foulbrood disease, and the genus Enterococcus; Cai J et al.; The 16S rRNA gene sequence of Melissococcus pluton, the causative agent of European foulbrood disease, was determined in order to investigate the phylogenetic relationships between this organism and other low-G + C-content gram-positive bacteria . A comparative sequence analysis revealed that M . pluton is a close phylogenetic relative of the genus Enterococcus. J Biol Chem, 1994 Apr 1, 269(13), 9453 - 9 Operon of vacuolar-type Na(+)-ATPase of Enterococcus hirae; Solioz M et al.; The Gram-positive bacteria Enterococcus hirae expel sodium by two systems: a Na+/H(+)-antiporter and a vacuolar-type Na(+)-ATPase . We isolated a mutant, NalkA, defective in the Na(+)-ATPase . NalkA grew normally at neutral pH but was unable to grow in the presence of > 100 mM sodium at pH 9.5 . By functional complementation at high pH, we cloned pES1, a plasmid from an E . hirae gene bank containing a 5.2-kilobase pair region of genomic DNA . The genomic DNA in pES1 contains five complete open reading frames, ntpM, -N, -O, -P, and -Q, encoding proteins of 75, 16, 23, 38, and 11 kDa . A sixth incomplete open reading frame, ntp 'L, precedes ntpM . The 3'-end of the cloned DNA overlaps with a previously published sequence encoding the ntpA and ntpB subunits of the E . hirae Na(+)-ATPase (Takase, K., Yamato, I., and Kakinuma, Y . 1993) J . Biol . Chem . 268, 11610-11616) . The insert of pES1 therefore represents the upstream region of the ntp operon that encodes the E . hirae Na(+)-ATPase . Complementation analysis with various deletions derived from pES1 suggest that the original mutation is in the ntpM gene . Of the new genes described here, three exhibited significant sequence similarity to known proteins; ntpM shares 24% identical amino acid residues with the "116-kDa" subunits of eukaryotic vacuolar ATPases, ntpN exhibits 28% sequence identity with the 16-kDa proteolipid of human vacuolar ATPase, and ntpO has sequence homology to the 31-kDa subunit of the bovine kidney vacuolar ATPase . No known proteins with sequence similarity to ntp'L, -P, or -Q could be identified . Disruption of either ntpM, -N, or -O in wild-type cells by cassette mutagenesis resulted in mutants unable to effect ATP-driven sodium extrusion . NtpM, -N, and -O therefore represent three new gene products involved in sodium extrusion by the vacuolar-type Na(+)-ATPase of E . hirae, and three more gene products, NtpL, -P, and -Q, may also be constituents of this enzyme . The ntp operon thus contains at least eight genes. J Chemother, 1994 Apr, 6(2), 121 - 6 Infections by ampicillin-resistant enterococci: a case-control study; Venditti M et al.; We identified 17 (20%) of 83 consecutive enterococcal isolates from hospitalized patients with documented infection as high-level ampicillin-resistant enterococci (ARE) . Of these, 16 isolates were identified as Enterococcus faecium and 1 isolate as Enterococcus raffinosus . A case-control study found no significant differences with respect to underlying diseases, central venous catheterization, nosocomial acquisition of the infection and sites of infection . Patients with ARE infection were older and had a higher inhospital fatality rate than those with ampicillin-susceptible Enterococcus (ASE) infection . Hospitalization in a surgery service (usually for an abdominal procedure), prolonged hospital stay, prior treatment with antibiotics (in particular imipenem and metronidazole), were also more frequent among patients with ARE infection . ARE isolates were more frequently resistant to imipenem, ciprofloxacin and streptomycin than ASE isolates. Antimicrob Agents Chemother, 1994 Apr, 38(4), 824 - 9 Synergy and resistance to synergy between beta-lactam antibiotics and glycopeptides against glycopeptide-resistant strains of Enterococcus faecium; Gutmann L et al.; A synergistic effect between vancomycin or teicoplanin and different beta-lactam antibiotics was found for two strains of Enterococcus faecium, EFM4 and EFM11, expressing resistance to glycopeptides and belonging to the VANA class . The MICs of penicillin for these two strains were 16 and 128 micrograms/ml, respectively . By using a penicillin-binding protein (PBP) competition assay, it was shown that the affinities of PBPs for different beta-lactam antibiotics and the MICs of these antibiotics obtained in the presence of teicoplanin correlated with the substitution of two high-molecular-weight PBPs for the low-molecular-weight PBP5 as the essential target . Mutants of EFM4 and EFM11 which had lost the synergistic effect between beta-lactams and glycopeptides were selected on teicoplanin plus ceftriaxone at a frequency of 10(-5) and 10(-3), respectively . The mechanism of the loss of synergy was explored . For the mutants derived from EFM4, it was associated with a change in PBPs, while for the mutants derived from EFM11, it was related to some unknown change on the conjugative plasmid responsible for the glycopeptide resistance . These combined observations reflect the relationship which seems to exist between the new D-lactate peptidoglycan precursor, synthesized when the vancomycin resistance is expressed, and the affinity of the different PBPs for this precursor. Kansenshogaku Zasshi, 1994 Apr, 68(4), 486 - 90 {Enterococcus faecium obtained from surveillance cultures of the stool of the patients with hematological malignancies}; Fukuda T et al.; Surveillance cultures of the stool were obtained from 55 patients with hematological malignancies, who have been receiving norfloxacin or tosufloxacin during their neutropenic periods, from May, 1991 to September, 1992 . Cultures were performed using 5% blood agar with piperacillin 300 micrograms/ml and amikacin 20 micrograms/ml and bacteria resistant to these antibiotics were analyzed further . Thirty-four over 55 patients were positive for enterococci and 22 strains of 23 examined were Enterococcus faecium . They are resistant to quinolones, aminoglycosides, cephalosporins and penicillins but not to vancomycin . Eighteen of them were also resistant to high-dose gentamicin . Appropriate measures should be used to prevent intrahospital spread of these resistant isolates. Singapore Med J, 1994 Apr, 35(2), 177 - 9 Five cases of high-level aminoglycoside resistant enterococcal septicaemia in Singapore; Chiew YF; Five clinical cases of enterococcal septicaemia were studied retrospectively including determination of high-level aminoglycoside resistance (HLAR) to gentamicin, streptomycin and kanamycin . This is the first study of its kind in Singapore . The clinical features and risk factors for this illness were analysed and found to be very similar to enterococcal bacteremia in general . It is important to carry out tests to detect HLAR so that unnecessary aminoglycoside toxicity can be prevented or to decide on the appropriate aminoglycoside to combine with a cell wall-active agent in severe enterococcal sepsis. J Antimicrob Chemother, 1994 Mar, 33(3), 553 - 61 vanA-mediated vancomycin-resistant Enterococcus spp . in sewage; Torres C et al.; Three high-level vancomycin-resistant Enterococcus strains (two Enterococcus faecium and one Enterococcus durans) were recovered from three of eight sewage samples taken from the general sewage collector at Logrono (Northern Spain) . The strains were present in the sewage samples at estimated concentrations of ten resistant bacteria/mL, corresponding to about 0.4% of the enterococcal population . The VanA protein was detected in each strain by immunoblotting of membrane extracts of the vancomycin-induced cells, and the vanA gene was demonstrated in the wild strains and their transconjugants by DNA-DNA hybridization . This is the first, confirmed report of vanA mediated vancomycin resistance in E . durans. J Am Vet Med Assoc, 1994 Feb 15, 204(4), 602 - 5 Administration of vancomycin for treatment of ascending bacterial cholangiohepatitis in a cat; Jackson MW et al.; A 12-year-old neutered male domestic shorthair cat, being treated with methimazole for hyperthyroidism, developed chronic cholangitis with portal fibrosis and chronic cholecystitis . The common bile duct was not patent, which necessitated cholecystojejunostomy . Four days after surgery, the cat developed suppurative cholangio-hepatitis caused by a beta-lactam resistant Enterococcus . The cat's condition was further complicated by the concurrent development of hypokalemic polymyopathy . On the basis of minimum inhibitory concentrations, the Enterococcus was determined to be susceptible to vancomycin and resistant to numerous antibiotics commonly used for treatment of infections caused by Enterococcus spp . The cat recovered without evidence of adverse effects attributable to vancomycin. Antimicrob Agents Chemother, 1994 Feb, 38(2), 385 - 7 Bactericidal activities of peptide antibiotics against multidrug-resistant Enterococcus faecium; Mobarakai N et al.; Multidrug-resistant Enterococcus faecium has emerged as a serious pathogen for which no effective therapy has been established . In this report, we describe the activities of two peptide antibiotics, ramoplanin and daptomycin, against 15 isolates of E . faecium resistant to vancomycin, ampicillin, and aminoglycosides using time-kill experiments . Both antibiotics were rapidly bactericidal when tested in broth; however, the addition of 50% serum resulted in significant regrowth . The combination of ampicillin with either ramoplanin or daptomycin largely prevented this regrowth . These peptide antibiotics showed good activity against these pathogens . While the development of daptomycin has been halted, ramoplanin may hold promise for the therapy of multidrug-resistant E . faecium, especially when combined with ampicillin. Clin Infect Dis, 1994 Feb, 18(2), 233 - 9 Enterococcal meningitis: report of four cases and review; Stevenson KB et al.; Enterococci, a significant cause of human infections outside of the CNS, have only rarely been documented to cause meningitis . To add to our understanding of this uncommon infectious process, we report our experience with four patients with enterococcal meningitis and summarize findings associated with 28 additional cases found in the medical literature . The majority of the adult patients with this condition had coexistent chronic underlying illnesses and were frequently exposed to immunosuppressive therapy . In addition, more than one-third of these patients had experienced CNS trauma or surgery, and 31% had an infection with enterococci at a site other than the CNS . Pediatric patients predominantly had underlying CNS pathology primarily consisting of neural tube defects or hydrocephalus . Primary meningitis occurred in 25% of pediatric patients, with most of these episodes occurring in neonates . Most patients presented with expected signs, symptoms, and physical features of acute bacterial meningitis and had typical CSF abnormalities, including leukocytic pleocytosis, elevated protein levels, and hypoglycorrhachia . The overall mortality rate among patients with enterococcal meningitis was 13% . The small number of patients in this review failed to demonstrate a definite difference in mortality among patients treated with cell wall-active agents alone vs . those treated with combination therapy with an aminoglycoside, although studies of patients with other complicated enterococcal infections suggest that combination therapy would be preferable. Diagn Microbiol Infect Dis, 1994 Feb, 18(2), 105 - 9 Enteric eradication of vancomycin-resistant Enterococcus faecium with oral bacitracin; O'Donovan CA et al.; The emergence of vancomycin-resistant Enterococcus faecium (VREF) has produced a therapeutic dilemma . The colonization of the intestinal tract with VREF may predispose patients to infections by this organism and may contribute to its nosocomial spread . It is reasonable to attempt to eradicate VREF from colonized patients . The optimal regimen, however, is unknown and this study was designed to evaluate the efficacy of oral regimens of vancomycin and bacitracin for the elimination of VREF from the enteric tract . Enterococcal isolates were tested for susceptibilities to vancomycin, bacitracin, and ampicillin with median minimum inhibitory concentrations of > 512 micrograms/ml, 10 units/ml, and 128 micrograms/ml, respectively . All patients were given an initial trial of oral vancomycin 125 mg every 6 h for 10 days . Those who failed oral vancomycin were then given oral bacitracin 25,000 units every 6 h for 10 days due to its favorable in vitro activity . VREF was eradicated from the stools of 42% of patients (eight of 19) receiving oral vancomycin as compared with all eight patients receiving oral bacitracin (P < 0.01) . The organism recurred in two bacitracin patients (25%) 8 and 20 days after completion of therapy . Whether prior vancomycin therapy predisposed patients to colonization by VREF was also examined . Ten (53%) of 19 patients had received prior vancomycin therapy before isolation of VREF from the stool . Our data suggest that oral bacitracin may be an effective alternative to commercially available oral vancomycin for the eradication of VREF from the enteric tract. Andrologia, 1994 Jan-Feb, 26(1), 35 - 8 Bacteroides ureolyticus in men consulting for infertility; Balmelli T et al.; A screening of 3196 semen analyses performed in our clinic from January 1986 to December 1990 revealed 314 (9.8%) patients whose semen was infected with Bacteroides ureolyticus . Investigating the relationship between the presence of B . ureolyticus, the seminal microflora and the conventional semen parameters, we observed that the presence of this micro-organism in the semen was coupled (1) to an increased presence of Enterococcus species, (2) to an increased number of short-tailed spermatozoa and epithelial cells, and (3) to a decreased total fructose concentration (mg ejaculate-1) . These results suggest that B . ureolyticus or its toxins may influence sperm morphology and function by yet unknown mechanisms and may also increase the number of epithelial cells by soft tissue infection in vivo . The decreased fructose levels suggest that this anaerobic micro-organism might specifically colonize the seminal vesicles, while the normal zinc values recorded suggest a normal prostatic function . Overall, our data support the hypothesis that the presence of B . ureolyticus is not associated with nongonococcal urethritis. Z Kardiol, 1994 Jan, 83(1), 2 - 8 {Antibiotic therapy of infectious endocarditis (when, with what drug, how long?}; Schuler G; The aim of antibiotic therapy in bacterial endocarditis is to sterilize infected cardiac structures and vegetations . Pathogenic organisms are present in great numbers within vegetations and abscess-formations . They exist in a state of reduced metabolic activity so that they are able to tolerate even therapeutic levels of bactericidal antibiotic concentrations . Because vegetations are normally devoid of blood vessels, impregnation with antibiotic agents is poor . Effective therapy is greatly improved by identification of the pathogenic organism involved . With very few exceptions isolation is possible prior to initiation of antibiotic therapy . In acute cases with signs of septicemia, however, therapy cannot await results of bacterial testing . In these patients selection of antibiotic agents is based on associated evidence such as the presence of a prosthetic heart valve or intravenous drug addiction . Once the pathogen has been identified antibacterial therapy should be tailored according to the test results . Bactericidal antibiotics should always be preferred over bacteriostatic agents; in many cases adequate bactericidal levels can only be achieved by combining various agents, such as ampicillin and gentamycin for treatment of enterococcal endocarditis . Dosing intervals must take into account the resulting trough levels, which should always exceed the minimal inhibitory concentrations for a specific bacterial strain . In cases with inadequate control of infection, congestive heart failure resulting from valve dysfunction, and abscess formation, surgery as the only means of eradicating the infection and restoring cardiac performance should not be delayed. R I Med, 1994 Jan, 77(1), 5 - 6 Bacterial endocarditis and septic arthritis presenting as polymyalgia rheumatica; Spomer A et al.; We describe a case of enterococcus endocarditis in a 74-year-old woman with hypercholesterolemia, porcine aortic valve, and osteoarthritis . She presented with the abrupt onset of severe back pain, proximal myalgia, and left knee synovitis, associated with an anemia and marked elevation of ESR . She was misdiagnosed as having polymyalgia rheumatica until both the synovial fluid and blood cultures grew enterococcus . Her musculoskeletal symptoms totally resolved with antibiotic treatment . Septic arthritis is a rare manifestation of bacterial endocarditis . However, one-third of all cases of bacterial endocarditis have musculoskeletal symptoms . These include backache, arthritis of the peripheral joints, and diffuse myalgia and arthralgia . Unexplained rheumatic complaints should alert us to the possibility of bacterial endocarditis. Med Dosw Mikrobiol, 1994, 46(1-2), 59 - 62 {Etiologic factors in acute inflammatory states of the abdominal cavity}; Pietkiewicz K et al.; Three hundred and two samples of biological material from patients operated because of acute inflammatory states of abdominal cavity were investigated . Both aerobic and anaerobic bacteria were investigated . Among aerobic flora most frequently occurred enterococci, E . coli and Pseudomonas . Bacteroides and Peptostreptococcus were most frequently occurring anaerobes . Mixed flora was seen very often . Isolated microorganisms were tested for susceptibility to ciprofloxacin, cefoperazone, cefotaxime, gentamicin, netilmicin and in cases of anaerobes to metronidazole. J Biol Chem, 1993 Dec 15, 268(35), 26334 - 7 Functional expression of the Enterococcus hirae NaH-antiporter in Escherichia coli; Strausak D et al.; We recently described the cloning of napA, the putative structural gene for the NaH-antiporter of Enterococcus hirae (Waser, M., Bienz-Hess, D., Davies, K., and Solioz, M . (1992) J . Biol . Chem . 267, 5396-5400) . To analyze the gene product of napA, we expressed it in Escherichia coli . When placed under the control of a T7 promoter, napA could be transcribed and labeled specifically with {35S}methionine . The resultant gene product exhibited an apparent M(r) of 3,4 x 10(4) when subjected to sodium dodecyl sulfate-gel electrophoresis . The function of NapA was tested by expressing it from its own promoter in the E . coli mutant EP432 . This mutant lacks both of the endemic NaH-antiporters, NhaA and NhaB; its growth is thus very sensitive to Na+ and Li+ and membranes derived from this strain do not exhibit NaH-antiport activity . When complemented with napA, EP432 gained tolerance to Na+ or Li+ . Membranes prepared from the complemented mutant exhibited NaH-antiport activity . The properties of this activity were determined by acridine fluorescence measurements on vesicles energized with lactate . The NaH-antiporter expressed by napA exhibited a Km of 1 mM for Na+ and 0.1 mM for Li+ at pH 7.5 . At pH 8.5, the relative rate of NaH-antiport activity was 50%, with little change in the Km, and approached zero at pH 9 . These results demonstrate that napA is the structural gene for the NaH-antiporter of E . hirae . NapA exhibits properties different from those of the two E . coli NaH-antiporters encoded by nhaA and nhaB, yet functionally complements a defect in these genes. J Clin Microbiol, 1993 Dec, 31(12), 3336 - 9 Reliability of the E test for detection of ampicillin, vancomycin, and high-level aminoglycoside resistance in Enterococcus spp; Schulz JE et al.; By comparison with agar dilution results, the E test was investigated for the ability to detect high-level aminoglycoside (gentamicin and streptomycin), ampicillin, and vancomycin resistance among strains representing six enterococcal species . For ampicillin and vancomycin, disk diffusion results also were obtained . No false high-level aminoglycoside resistance occurred, and no false gentamicin susceptibility was noted . With the high-range streptomycin E test (2,048 micrograms), 24% of the 38 resistant strains were falsely susceptible . However, these discordances could likely be reconciled by adjustments in incubation duration and by using broth microdilution rather than agar screen breakpoint criteria, or by using the lower-range (1,024-micrograms) strip . For ampicillin, category results obtained by E test and disk diffusion showed good agreement with agar dilution; E test MICs were generally comparable to agar dilution MICs . The E test was more sensitive than disk diffusion for detecting vancomycin-intermediate strains, but for these strains and those exhibiting low-level vancomycin resistance (MIC, 32 to 128 micrograms/ml), disk diffusion and E test inhibition zones must be interpreted with caution . Given the reliability of E test for detecting resistance to anti-enterococcal agents, the decision to use this method should be based on convenience, cost, testing frequency, and satisfaction with currently used methods. Biochim Biophys Acta, 1993 Nov 7, 1179(2), 166 - 9 Na+ and K+ transport by 4-chlorophenylurethane-monensin in Enterococcus hirae de-energized and energized cells studied by 23Na-NMR and K+ atomic absorption; Rabaste F et al.; Na+ and K+ movements induced by 4-chlorophenylurethane-monensin, which presents an inverted ion selectivity (K+ > Na+) in model systems compared with monensin, were followed on Enterococcus hirae cells by 23Na-NMR and K+ atomic absorption . For de-energized cells, the urethane derivative is much more selective for K+ than monensin, but only at low concentrations (10(-3)-10(-4) mM) . For higher concentrations, as previously shown for monensin, the sodium and potassium movements are driven by the ion gradients present . On energized cells, both K+ and Na+ gradients were highly perturbed, and this can be related to the higher toxicity in mice and bacteria for this derivative. Antimicrob Agents Chemother, 1993 Nov, 37(11), 2427 - 31 High-level penicillin resistance and penicillin-gentamicin synergy in Enterococcus faecium; Torres C et al.; Thirty-seven Enterococcus faecium strains with different levels of penicillin susceptibility were studied in time-kill experiments with a fixed concentration (5 micrograms/ml) of gentamicin combined with different penicillin concentrations (6 to 600 micrograms/ml) . Synergy was defined as a relative decrease in counts of greater than 2 log10 CFU per milliliter after 24 h of incubation when the combination of the antibiotics was compared with its most active component alone . The minimal synergistic penicillin concentrations found were 6 micrograms/ml for 16 of 16 strains for which penicillin MICs were < or = 25 micrograms/ml, 20 to 100 micrograms/ml for 14 of 17 strains for which penicillin MICs were 50 to 200 micrograms/ml, and 200 to 500 micrograms/ml for 4 of 4 strains for which MICs penicillin were > 200 micrograms/ml . Penicillin-gentamicin synergy was observed even in high-level penicillin-resistant E . faecium strains at penicillin concentrations close to one-half the penicillin MIC . The possibility of treating infections caused by high-level penicillin-resistant E . faecium strains with penicillin-gentamicin combinations in particular cases may depend on the penicillin levels attainable in vivo. Dig Dis Sci, 1993 Nov, 38(11), 2104 - 12 Antibacterial activity of bile salts against common biliary pathogens . Effects of hydrophobicity of the molecule and in the presence of phospholipids; Sung JY et al.; In vitro studies have demonstrated that bile salts have cytotoxic and bacteriostatic properties . The cytotoxic effect of bile salts is reduced when lecithin is added . The effect of lecithin on the bacteriostatic property of bile salts is not known . In this report, we test the hypotheses that (1) the bacteriostatic activity of bile salts is a function of the hydrophobicity of the molecules, and (2) lecithin, by engaging the hydrophobic component of bile salts, attenuates the bacteriostatic property of these molecules . Two common biliary pathogens, Escherichia coli and Enterococcus fecalis, were tested in this experiment . The results demonstrate that hydrophobic bile salts (sodium taurodeoxycholate, sodium deoxycholate) have more significant inhibition on the growth of bacteria when compared with the hydrophilic bile salts (sodium taurocholate, sodium chenodeoxycholate, and sodium tauroursodeoxycholate) . When lecithin is added, creating a mixed micellar solution and mimicking the in vivo conditions, the antibacterial activities of even the more potent bacteriostatic bile salts are significantly reduced . The finding that lecithin significantly attenuates the bacteriostatic property of even the hydrophobic bile salts raises questions about the clinical significance of such bacteriostatic effect in vivo; as bile salts in the bile exist in mixed micellar solution. Infect Control Hosp Epidemiol, 1993 Nov, 14(11), 629 - 35 A case-control study of nosocomial ampicillin-resistant enterococcal infection and colonization at a university hospital; Sexton DJ et al.; OBJECTIVE: To assess risk factors for colonization and nosocomial infection with ampicillin-resistant enterococci (ARE) . DESIGN: Patients with ampicillin-resistant enterococci were compared retrospectively by logistic regression analysis with controls harboring susceptible strains . ARE were characterized by whole plasmid DNA analysis and restriction enzyme analysis of plasmid (REAP) DNA with EcoRI . SETTING: The study was done at a 1,125 bed, tertiary-care teaching hospital in North Carolina with patients from whom enterococci were isolated from June 1, 1989, to March 30, 1991 . PATIENTS: The final study group comprised 44 cases with nosocomially-acquired colonization or infection with ARE and 100 controls with ampicillin-susceptible strains . Clinical and epidemiological risk factors for ARE were abstracted by chart review . RESULTS: After controlling for age and site of infection, patients with ARE were more likely to have been admitted previously to our hospital and to have received third-generation cephalosporins and clindamycin . However, only advanced age and clindamycin therapy were independently associated with presence of ARE . REAP with EcoRI showed 20 groups of enterococci on 19 different wards . CONCLUSIONS: These results suggest that ARE are endemic and multifocal in origin in our hospital and that advanced age and use of clindamycin are important selective risk factors for ARE colonization and infection. Antimicrob Agents Chemother, 1993 Oct, 37(10), 2069 - 73 Antibiotic treatment of experimental endocarditis due to vancomycin- and ampicillin-resistant Enterococcus faecium; Whitman MS et al.; We compared ciprofloxacin, rifampin, and gentamicin treatments, alone and in combination, for 5 days in the therapy of experimental aortic valve endocarditis in rats caused by a clinical isolate of vancomycin-resistant Enterococcus faecium . The MICs and MBCs of vancomycin, ciprofloxacin, rifampin, and gentamicin were 250 and > 1,000, 3.1 and 6.3, 0.098 and 1.6, and 12.5 and > 50 micrograms/ml, respectively . Infected rats were sacrificed after completing 5 days of therapy . Additional rats within each treatment group were followed for 5 days beyond the last dose of antibiotic therapy . Although survivals in the different groups were not significantly different after 5 days of therapy, survival was significantly better 5 days beyond the last dose of antibiotic therapy in rats treated with rifampin-containing regimens . The combination of ciprofloxacin and gentamicin was bactericidal in vitro and in vegetations from rats with enterococcal endocarditis . Rifampin alone was similarly bactericidal in vivo, but it was not significantly better than rifampin in combination with other antibiotics . Subpopulations resistant to rifampin, but not ciprofloxacin, were detected in the inoculum and in most vegetations during therapy . However, the combination of ciprofloxacin plus both gentamicin and rifampin reduced both the rifampin-susceptible and -resistant population in vegetations of 9 of 10 animals below the level of detection after 5 days of therapy . Nevertheless, a residual enterococcal population apparently remained in numbers of < 2 log10 CFU/g after 5 days of therapy, which resulted in relapse . Perhaps a longer course of therapy would have eliminated this residual population and improved efficacy. J Clin Microbiol, 1993 Oct, 31(10), 2786 - 7 Evaluation of MicroScan rapid panels for detection of high-level aminoglycoside resistance in enterococci; Woods GL et al.; The ability of MicroScan rapid panels to detect high-level aminoglycoside-resistant enterococci was evaluated . By agar dilution, 46 of 139 isolates were susceptible to gentamicin (GNT) and streptomycin (STRP); the rest were highly resistant to one or both agents . Rapid panels detected 97.5% of STRP- and GNT-resistant isolates and had a specificity of 95.6% . Detection of resistance by conventional panels at 18 h was 64.6% for STRP and 90.2% for GNT. Appl Environ Microbiol, 1993 Oct, 59(10), 3411 - 7 Modeling the growth of Enterococcus faecium in bologna sausage; Zanoni B et al.; A study to set up mathematical models which allow the prediction of Enterococcus faecium growth in bologna sausage (mortadella) was carried out . Growth curves were obtained at different temperatures (5, 6, 12, 15, 25, 32, 35, 37, 42, 46, 50, 52, and 55 degrees C) . The Gompertz and logistic models, modified by Zwietering, were found to fit with the representation of experimental curves . The variations of the parameters A (i.e., the asymptotic value reached by the relative population during the stationary growth phase), mu m (i.e., the maximum specific growth rate during the exponential growth phase), and lambda (i.e., the lag time) with temperature were then modeled . The variation of A with temperature can be described by an empirical polynomial model, whereas the variation of mu m and lambda can be described by the Ratkowsky model modified by Zwietering and the Adair model, respectively . Data processing of these models has shown that the minimum growth temperature for E . faecium is 0.1 degrees C, the maximum growth temperature is 53.4 degrees C, and the optimal growth temperature is 42 to 45 degrees C. Semin Perioper Nurs, 1993 Oct, 2(4), 262 - 8 Vancomycin-resistant enterococcus: an emerging nosocomial pathogen and its implications for the operating room setting; Hernandez JM et al.; Enterococci, an emerging group of nosocomial pathogens with high-level resistance to various antibiotics, will demand effective, conscientious, and continuous use of Universal Precautions to combat their pernicious threat . Effective Universal Precautions/body substance isolation infection control precautions and methodologies and innovative medical and surgical procedures will play a significant role in containing these highly infectious pathogens. Biochem Biophys Res Commun, 1993 Sep 15, 195(2), 1063 - 9 A gene encoding the 16-kDa proteolipid subunit of Enterococcus hirae Na(+)-ATPase complex; Kakinuma Y et al.; By further sequencing the cloned genome DNA of Enterococcus hirae that retains the genes encoding two major subunits of Na(+)-transport ATPase (Takase, K., Yamato, I., and Kakinuma, Y . (1993) J . Biol . Chem . 268, 11610-11616), we found a gene, ntpK, encoding a very hydrophobic protein of 156 amino acids (Mr = 16,036) . The amino acid sequence deduced from the ntpK gene matched with the partial sequence of a 16-kDa protein purified as the proteolipid component of Na(+)-ATPase . The amino acid sequence and the hydropathy profile of the NtpK product were very similar with those of the 16-kDa proteolipids of vacuolar (V-) H(+)-ATPases in eukaryotes . The amino-terminal half of this sequence was highly homologous to the carboxyl-terminal half, suggesting that it was evolved from a common ancestral gene through duplication . The proteolipid of E . hirae Na(+)-ATPase belongs to that of the eukaryotic V-ATPase. J Infect Dis, 1993 Sep, 168(3), 681 - 6 Triple combination penicillin-vancomycin-gentamicin for experimental endocarditis caused by a highly penicillin-and glycopeptide-resistant isolate of Enterococcus faecium; Caron F et al.; A combination of low-dose penicillin (75,000 IU/kg twice daily {b.i.d.}) vancomycin (30 mg/kg b.i.d.) and gentamicin (6 mg/kg b.i.d.) has been shown to be as effective as a combination of high-dose penicillin (500,000 IU/kg b.i.d.) and gentamicin (6 mg/kg b.i.d.) in the treatment of rabbit endocarditis caused by an Enterococcus faecium strain moderately resistant to beta-lactams and highly resistant to glycopeptides . The same regimens were evaluated against an E . faecium strain highly resistant to both penicillin (MIC, 128 micrograms/mL) and vancomycin (MIC, 512 micrograms/mL) . High doses of penicillin-gentamicin and vancomycin-gentamicin had no effect in in vitro killing-curve studies or in rabbits after treatment for 5 days . High doses of penicillin-vancomycin were only bacteriostatic in killing curves and provided a small reduction in the bacterial titers of the vegetations . In contrast, high-dose penicillin-vancomycin-gentamicin was bactericidal in vitro and highly effective in treating rabbits . However, the emergence of a bacterial subpopulation resistant to the synergistic effect of penicillin and vancomycin could reduce the clinical utility of this combination. Antimicrob Agents Chemother, 1993 Sep, 37(9), 1904 - 8 Novel antibiotic regimens against Enterococcus faecium resistant to ampicillin, vancomycin, and gentamicin; Landman D et al.; Enterococci have emerged as significant nosocomial pathogens . Enterococci with resistance to commonly used antibiotics are appearing more frequently . We encountered at our institution several infections caused by Enterococcus faecium with high-level resistance to ampicillin, vancomycin, and gentamicin . The optimal antibiotic therapy for serious infections with unusually resistant enterococci has not been established . Using time-kill studies, we tested the effectiveness of various antibiotic combinations against 15 isolates of multidrug-resistant enterococci . No antibiotic was consistently effective when used alone . The combination of ampicillin plus ciprofloxacin was bactericidal for the 12 isolates for which the ciprofloxacin MIC was < or = 8 micrograms/ml . The combination of ciprofloxacin plus novobiocin also demonstrated activity against these isolates . No combination was found to be bactericidal for the remaining three isolates, which were highly ciprofloxacin resistant . These antibiotic combinations may be important for the future treatment of serious infections caused by these resistant pathogens. Antimicrob Agents Chemother, 1993 Sep, 37(9), 1896 - 903 Characterization of the chromosomal aac(6')-Ii gene specific for Enterococcus faecium; Costa Y et al.; Chromosomal gene aac(6')-Ii of Enterococcus faecium CIP 54-32, encoding a 6'-N-aminoglycoside acetyltransferase was characterized . The gene was identified as a coding sequence of 549 bp corresponding to a protein with a calculated mass of 20,666 Da . Analysis of the sequence of the deduced protein suggested that it was the second member of a subfamily of AAC(6')-I enzymes . Insertional inactivation of aac(6')-Ii led to aminoglycoside susceptibility of CIP 54-32, suggesting that this gene plays a role in resistance to AAC(6')-I substrates . The gene was detected by DNA hybridization in all 26 strains of E . faecium tested but not in 44 other enterococci of 13 species . These data suggest that the aac(6')-Ii gene is species specific and may be used to identify E . faecium. MMWR Morb Mortal Wkly Rep, 1993 Aug 6, 42(30), 597 - 9 Nosocomial enterococci resistant to vancomycin--United States, 1989-1993; Examination gloves as barriers to hand contamination in clinical practice; Department of Epidemiology, Harborview Medical Center, Seattle, WAOBJECTIVE--To test the effectiveness of vinyl and latex gloves as barriers to hand contamination with gram-negative organisms and enterococci during routine hospital procedures . DESIGN AND INTERVENTIONS--We studied 137 procedures during which a health care worker's gloved hand contacted a patient's mucous membrane and was thus potentially contaminated with gram-negative rods or enterococci . Quantitative hand cultures were obtained from each health care worker before and after the gloved contact using a modified glove juice method, and the exterior glove surface was also quantitatively cultured after patient contact . Used gloves were then tested for leaks using the American Society for Testing and Materials' watertight test . SETTING--Harborview Medical Center, a 330-bed city-county hospital and level I regional trauma and burn center, is both a teaching facility affiliated with the University of Washington and the major provider of care to indigent and uninsured persons in Seattle-King County, Washington . PATIENTS AND OTHER PARTICIPANTS--Respiratory therapists performing endotracheal tube care on intubated intensive care unit patients, registered nurses performing digital rectal stimulation for bowel training on patients with spinal cord injury in the rehabilitation ward, and dentists performing routine dental examinations and procedures on healthy outpatients in the dental clinic . MAIN OUTCOME MEASURE AND RESULTS--Eighty-six of the 135 gloves cultured had gram-negative rods or enterococci on the external surface after use and were thus sources of potential hand contamination . Microbial contamination of the health care worker's hands occurred in 11 (13%; 95% confidence interval, 6% to 20%) of these 86 events, and was more frequent with vinyl (10 of 42) than latex (one of 44) gloves (P < .01) . After use, glove leaks were also more frequent in vinyl gloves (26 of 61) than with latex gloves (six of 70) (P < .001) . Even when leaks were present, gloves prevented hand contamination in 77% of instances and quantitative counts of microorganisms contaminating hands were 2 to 4 logs less than counts on external glove surfaces . Health care workers reported awareness of the presence of glove leaks in only seven (22%) of the 32 events in which leaks were subsequently demonstrated . CONCLUSIONS--Under conditions of routine use, gloves effectively function as a protective barrier even when leaks are present . Latex gloves were less frequently associated with leaks and hand contamination . Since hand contamination occurred after 13% of exposures and cannot be readily identified by health care workers, routine hand washing should be done after each patient contact. Lancet, 1993 Jul 10, 342(8863), 76 - 9 Emergence of vancomycin-resistant enterococci in New York City; Frieden TR et al.; Enterococci, a common cause of nosocomial infection, are intrinsically resistant to most antimicrobials and readily acquire additional resistance . Vancomycin-resistant enterococci (VRE) have caused clusters of nosocomial infections since 1988 . In April, 1991, the New York City Department of Health asked all city laboratories to submit suspected VRE isolates for confirmation . Clinical and epidemiological characteristics of the first 100 patients with VRE were identified, and antimicrobial susceptibility testing, restriction enzyme analysis, and DNA-DNA hybridisation with the vanA gene probe were done . From September, 1989, to October, 1991, 361 patients with VRE were identified at 38 hospitals . The number of hospitals reporting VRE increased from 1 in 1989 to 38 by October, 1991 . 98% of 100 VRE infections were nosocomially acquired and 83% patients had received vancomycin and/or a cephalosporin in the 30 days before isolation of VRE . Of 23 isolates from 21 of the first 100 patients, 19 (83%) were resistant to all available antimicrobials . Four vanA probing patterns were noted, and restriction enzyme analysis of the 23 isolates revealed 14 strains . VRE have emerged rapidly in New York City . Molecular analyses suggest that a highly mobile genetic element--eg, a transposon--is responsible for the rapid spread of vancomycin resistance. Zentralbl Hyg Umweltmed, 1993 Jul, 194(4), 369 - 79 {Superheating of germ carriers falsifies the steam resistance of bioindicators}; Spicher G et al.; In the course of experiments on the resistance of bioindicators in saturated steam the authors noticed that carriers made of filter paper showed superheating by hygroscopic condensation . The differences in temperature between the bioindicators and the saturated steam amounted to about 5 Kelvin . Even after 20 minutes temperature equilibrium has not been reached . As a result of overheating and reduced water activity the frequency of bioindicators with surviving test organisms was increased . Beyond that, the microbiologic results depended on storage conditions of the bioindicators before putting them into the resistometer . The lower (higher) the-relative humidity, the higher (lower) the superheating, and the higher (smaller) the frequency of indicators with test organisms having survived . Carriers made of glass fibre fleece did not show any superheating and related effects . But carriers onto which small amounts of a suspension of test organisms in blood have been dried on, gave a superheating of about 1.7 Kelvin . Under identical conditions t50% values of bioindicators made of filter paper and bioindicators made of glass fibre fleece differed considerably . Experiments with Enterococcus faecium as test organism at 75 degrees C resulted in 14.4 and 1.7 minutes, respectively . Therefore, the high resistance of test organisms dried onto filter paper is an artefact caused by superheating . The experimental results should have consequences on the manufacture and use of bioindicators as well as chemoindicators and on the evaluation of results got with them. J Biol Chem, 1993 Jun 15, 268(17), 12775 - 9 Primary structure of two P-type ATPases involved in copper homeostasis in Enterococcus hirae; Odermatt A et al.; We cloned an operon, copAB, from Enterococcus hirae encoding two P-type ATPases of 727 and 745 amino acids, respectively . Both enzymes display heavy metal ion binding motifs in their polar N-terminal region . With an antibody against CopB, we showed on Western blots that expression of the operon is induced by either low or high ambient copper concentrations . Disruption of the copA gene renders the cells dependent, whereas copper disruption of copB results in a copper-sensitive phenotype . CopA exhibits 35% sequence similarity to CopB and 43% similarity to the ATPase encoded by the recently cloned human Mc1 gene, a gene responsible for the Menkes inborn error of copper metabolism . Our results imply that CopA and CopB are heavy metal ion ATPases that regulate the cytoplasmic copper activity, with CopA serving in the uptake and CopB in the extrusion of copper. Antimicrob Agents Chemother, 1993 Jun, 37(6), 1238 - 42 Constitutively vancomycin-resistant Enterococcus faecium resistant to synergistic beta-lactam combinations; Green M et al.; Vancomycin resistance among enterococci has recently been recognized . Synergy between vancomycin and penicillin has been shown in vitro for isolates of Enterococcus faecium resistant to both of these antibiotics . We describe three isolates of vancomycin-resistant E . faecium which demonstrate unique phenotypic characteristics . The isolates exhibited high-level resistance to both vancomycin and teicoplanin, consistent with the VanA phenotype . However, resistance in these isolates could not be induced or cured, and mating experiments failed to detect a transfer of resistance . The combination of vancomycin and penicillin did not significantly change the MIC of penicillin for any of the three isolates . Immunoblotting with polyclonal anti-VanB antibody showed no reaction with the cellular proteins of these strains . Probing with a vanA oligonucleotide revealed hybridization with chromosomal but not plasmid DNA . The mechanism of constitutive resistance of those strains remains unclear . A second mutational change, perhaps involving PBP 5, may explain the presence of resistance to synergistic combination penicillin-vancomycin therapy . In vitro evaluation of penicillin-vancomycin should be carried out in all clinical cases where this therapeutic regimen is being considered. J Clin Microbiol, 1993 Jun, 31(6), 1609 - 11 Clonal spread of vancomycin-resistant Enterococcus faecium between patients in three hospitals in two states; Chow JW et al.; The DNAs of 3* vancomycin-resistant Enterococcus faecium isolates from five hospitals in three states were analyzed by contour-clamped homogeneous electric field electrophoresis and plasmid analysis . There were 22 strain types . One strain type was common to patients in three hospitals in two states . These results suggest the apparent intra- and interhospital spread of vancomycin-resistant E . faecium. Biochemistry, 1993 May 18, 32(19), 5057 - 63 Purification and characterization of VanR and the cytosolic domain of VanS: a two-component regulatory system required for vancomycin resistance in Enterococcus faecium BM4147; Wright GD et al.; Resistance to the glycopeptide antibiotic vancomycin requires five genes . Two of these, vanR and vanS, have sequence homology to cytoplasmic response regulatory (VanR) and transmembrane sensory (VanS) proteins of two-component regulatory systems used to sense and transduce environmental signals . We report the overproduction and purification to homogeneity of VanR (27 kDa) and of a fusion protein of VanS (residues 95-374, the cytosolic domain) to the maltose binding protein (MBP), yielding a MBP-VanS protein of 76 kDa . The MBP-VanS fusion protein displayed an ATP-dependent autophosphorylation on a histidine residue with a rate of 0.17 min-1 and a phosphorylation stoichiometry of 10-15% . 32P-PhosphoMBP-VanS transferred the phosphoryl group to VanR . 32P-Phospho VanR showed chemical stability anticipated for an aspartyl phosphate and was relatively stable to hydrolysis (t1/2 = 10-12 h) . Thus, the vancomycin resistance operon appears to have collected and specifically tailored the His kinase and Asp phosphoryl receptor of two-component signal transduction logic for sensing extracellular vancomycin and turning on structural genes, vanA and vanH, to make altered peptidoglycan structures such that vancomycin does not bind. Antimicrob Agents Chemother, 1993 May, 37(5), 1190 - 2 Antimicrobial susceptibilities of enterococci isolated from hospitalized patients; Venditti M et al.; One hundred and one isolates of Enterococcus species isolated recently from hospitalized patients were evaluated in vitro for antibiotic susceptibility . Teicoplanin and mideplanin were the most active agents, followed by ramoplanin, vancomycin, ciprofloxacin, ampicillin, and imipenem . High-level resistance to gentamicin (MIC > 500 micrograms/ml) and/or streptomycin (MIC > 2,000 micrograms/ml) was found in 60 isolates . High-level resistance to ampicillin (MIC > or = 16 micrograms/ml) was found in 17 isolates . MBC studies revealed that ramoplanin possesses significant bactericidal activity. Cornea, 1993 May, 12(3), 273 - 6 Enterococcal infectious crystalline keratopathy; Lam S et al.; Two patients developed infectious crystalline keratopathy (ICK) 9 and 11 months after penetrating keratoplasty . In both cases, cultures yielded enterococcus sensitive to vancomycin . The first patient developed diffuse loss of corneal and conjunctival epithelia after 24 h of treatment with vancomycin eyedrops, whereas the second patient did not respond after 14 days of topical vancomycin therapy . Both patients eventually required penetrating keratoplasty . Enterococcus is a ubiquitous bacterium resistant to many antibiotics that should be suspected of causing ICK. Int J Food Microbiol, 1993 May, 18(3), 211 - 21 Comparative evaluation of two methods of enumerating enterococci in foods: collaborative study; Peterz M et al.; Two methods of enumerating enterococci in foods were compared in a collaborative study . Thirteen laboratories tested four blind duplicate samples containing different levels of enterococci and two negative control samples . Freeze-dried mixtures of bacteria were used as simulated food samples . The freeze-dried samples were reconstituted and either spread directly on the surface of Slanetz and Bartley medium (SB) and incubated at 44 degrees C for 48 h or preincubated in tryptone soya agar at 37 degrees C for 2 h before being overlaid by SB and incubated at 37 degrees C for a further 46 h . The numbers CFU of enterococci recovered by the two methods were not significantly different except for one sample where the 37 degrees C method gave a somewhat higher recovery . The 44 degrees C method was less time-consuming and less laborious. J Bacteriol, 1993 May, 175(10), 3213 - 9 Characterization of intergenic spacers in two rrn operons of Enterococcus hirae ATCC 9790; Sechi LA et al.; Two DNA restriction enzyme fragments coding for the 3' termini of 16S rRNA, the 5' termini of 23S rRNA, and the intergenic spaces between them in Enterococcus hirae ATCC 9790 were cloned and sequenced . The intergenic space of one of these genes contains a tRNA(Ala) sequence, whereas the other does not . Nevertheless, the intergenic spaces contain several regions that exhibit high levels of sequence homology and are capable of forming structures with similar base pairs . An analysis of Southern blots of chromosomal DNA cut with one and two restriction enzymes indicated that E . hirae has a total of six rrn operons. J Infect Dis, 1993 May, 167(5), 1224 - 7 In vivo development of teicoplanin resistance in a VanB Enterococcus faecium isolate; Hayden MK et al.; Acquired vancomycin resistance in enterococci may be associated with teicoplanin susceptibility (VanB) or teicoplanin resistance (VanA) . This paper characterizes the first instance of in vivo emergence of teicoplanin resistance in an Enterococcus faecium strain of VanB phenotype . Vancomycin-resistant (MIC, 256/512 micrograms/mL) E . faecium was isolated intermittently from a patient's blood over 4 months . The MIC of teicoplanin for the first 5 isolates was 1.0 micrograms/mL; it was 64 micrograms/mL for the final 2 . Analysis of plasmid and chromosomal DNA revealed the isolates to be of clonal origin . Conjugal transfer of vancomycin resistance was not obtained . A vanB DNA probe hybridized with both teicoplanin-susceptible and resistant isolates, but a vanA probe failed to hybridize with any isolate . SDS-PAGE of membrane proteins from a teicoplanin-resistant isolate revealed constitutive production of a normally inducible 41-kDa protein . These findings challenge the ultimate utility of teicoplanin for treatment of infections caused by vancomycin-resistant enterococci. J Antimicrob Chemother, 1993 May, 31 Suppl D, 87 - 95 The Enterococcus endocarditis model in experimental animals and its relevance to human infection; Gutschik E; The model of plastic-catheter induced left-sided enterococcal endocarditis has been used since 1970 in rabbits and since 1978 in rats in order to describe the pathophysiology of this unique infectious disease and to assess the most efficacious antibiotic regimens for treatment and prevention . A critical review of the experimental design is presented with a proposal of longer duration of therapy, recognition of relapse, and reisolation of infecting strains for susceptibility testing . The natural history of left-sided experimental enterococcal endocarditis is described and the results of classical beta-lactam-aminoglycoside combinations are reviewed . Interesting new observations on antibiotic dosing principles are discussed and new combinations of antibiotics against beta-lactamase producing enterococcal strains, strains highly resistant to gentamicin or resistant to glycopeptide antibiotics, are appraised for treatment and prophylaxis. J Antimicrob Chemother, 1993 May, 31(5), 711 - 23 In-vitro synergy and mechanism of interaction between vancomycin and ciprofloxacin against enterococcal isolates; Unal S et al.; In-vitro synergy between vancomycin and ciprofloxacin against 44 enterococcal isolates was studied . Synergy occurred in chequerboard MIC determinations with six Enterococcus faecium strains resistant to both vancomycin and ciprofloxacin . The combination was additive for strains susceptible to one or both antibiotics . Time-kill studies involving selected strains with different susceptibility patterns confirmed the chequerboard results . The effect of ciprofloxacin on the induction of vancomycin resistance was compared in two vancomycin-resistant strains of E . faecium . Sub-inhibitory concentrations of ciprofloxacin prevented induction of vancomycin resistance in a ciprofloxacin-resistant strain, but not in a ciprofloxacin-susceptible strain . Membranes isolated from vancomycin-resistant ciprofloxacin-resistant cultures grown with vancomycin and ciprofloxacin at < or = 8 mg/L (0.125 x MIC) expressed a 39.5-kDa membrane protein involved in the expression of vancomycin resistance, but the protein was not detected in membranes from cultures grown in ciprofloxacin 16 mg/L . These findings indicated that a vancomycin-ciprofloxacin combination can be synergic against enterococci resistant to both vancomycin and ciprofloxacin, but would be unlikely to offer any advantage in the treatment of enterococcal infections because of the high concentrations required. J Clin Pathol, 1993 May, 46(5), 474 - 5 Colonial variation in vancomycin resistant Enterococcus faecium; Baillie LW et al.; Vancomycin resistant enterococci are increasingly being isolated from inpatients . This report describes the colonial variation present in most isolates of vancomycin resistant Enterococcus faecium obtained at this hospital . Colonial variants within the same culture were indistinguishable by antimicrobial susceptibility, biochemical reactions, and ribotyping . Failure to appreciate this colonial variation will lead to pure cultures being regarded as contaminated or mixed. Eur J Clin Microbiol Infect Dis, 1993 Apr, 12(4), 241 - 7 Enterococcal septicemia in patients with hematological malignancies; Venditti M et al.; Thirty-six cases of enterococcal septicemia in patients with hematological malignancies were reviewed retrospectively and categorized according to their clinical significance using strict previously described definitions . Overall, most of the infected patients were males (77%), had acute leukemia (64%), had recently received cytotoxic drug therapy (86%), were granulocytopenic at the onset of septicemia (77%), and acquired the infection during hospitalization (77%) . The source of septicemia was unknown in 18 (50%) patients, intestinal in 15 (42%) and intravascular in three (8%) . Mortality was 19% among 21 inpatients who had clinically significant septicemia and 30% among patients with septicemia of uncertain clinical significance . The fatal outcome could be definitively attributed to enterococcal septicemia in only one of the nine inpatients who died . Clinically significant septicemia appeared somewhat more frequently to be polymicrobial (p = 0.06), whereas septicemia of unknown significance presented more frequently as breakthrough septicemia (p = 0.013) . Unless associated with intravascular infection, enterococcal septicemia in patients with hematological malignancies seems to represent a marker of cytotoxic drug damage of the intestinal mucosa rather than a truly invasive infection. Am Surg, 1993 Apr, 59(4), 219 - 22 Pyogenic hepatic abscess: a case for open drainage; Hansen N et al.; A retrospective review of 24 patients treated at the University of Chicago for pyogenic liver abscess from 1979 to 1989 was performed to determine if there is a changing etiology in pyogenic liver abscess and if percutaneous drainage is a reliable treatment alternative to open drainage . Biliary tract disease was the most common cause and presented in 29 per cent of patients . Klebsiella and enterococcus were the most common bacterial organisms cultured in 33 and 29 per cent of patients, respectively . The overall mortality rate was 25 per cent, however, if open drainage, in addition to a definitive procedure such as cholecystectomy or bowel resection was performed, there were no deaths . We therefore recommend the use of percutaneous drainage alone only in selected patients. J Trauma, 1993 Apr, 34(4), 579 - 84; discussion 584-5 Abdominal surgical wound infection is lowered with improved perioperative enterococcus and bacteroides therapy; Weigelt JA et al.; Perioperative antibiotics decrease surgical wound infection (SWI) in trauma patients requiring abdominal exploration . This investigation evaluated 24 hours of cefoxitin or ampicillin/sulbactam used for early therapy in such patients . Patients were randomly assigned to one of two treatment groups . The primary endpoint evaluated was SWI, which was defined as purulent drainage or active wound treatment . Five hundred ninety-two patients were evaluated: 283 received ampicillin/sulbactam and 309 received cefoxitin . The incidence of wound infection among the ampicillin/sulbactam patients was 2% and among cefoxitin patients it was 7% (p < 0.004) . The cefoxitin patients with colon injuries were analyzed (p < 0.007) . The major difference between the two groups was an increased incidence of enterococcal infections in the cefoxitin-treated patients . A single broad-spectrum antibiotic given for 24 hour perioperatively effectively controls SWI . Use of ampicillin/sulbactam results in a significantly lower SWI rate than use of cefoxitin, which may be a result of improved enterococcal and Bacteroides coverage. J Bacteriol, 1993 Apr, 175(7), 2046 - 51 Identification of a genetic element (psr) which negatively controls expression of Enterococcus hirae penicillin-binding protein 5; Ligozzi M et al.; Enterococcus hirae ATCC 9790 produces a penicillin-binding protein (PBP5) of low penicillin affinity which under certain conditions can take over the functions of all the other PBPs . The 7.1-kb EcoRI fragment containing the pbp5 gene of this strain and of two mutants, of which one (E . hirae R40) overproduces PBP5 and the other (E . hirae Rev14) does not produce PBP5, was cloned in pUC18 and sequenced . In the 7.1-kb EcoRI fragment cloned from strain ATCC 9790, an open reading frame (psr) potentially encoding a 19-kDa protein was identified 1 kb upstream of the pbp5 gene . An 87-bp deletion in this element was found in the 7.1-kb EcoRI fragment cloned from strains R40 and Rev14 . In addition, several base substitutions were found in the pbp5 genes of strains R40 and Rev14 . One of these converted the 42nd codon, TCA, to the stop codon, TAA, in the pbp5 gene of Rev14 . Escherichia coli strains were transformed with plasmids carrying the 7.1-kb EcoRI insert or a 2.6-kb HincII insert containing only the pbp5 gene of the three strains . Immunoblotting analysis of proteins expressed by these transformants showed that the 87-bp deletion in psr was associated with the PBP5 overproducer phenotype of strain R40 and the conversion of the TCA codon to the stop codon was associated with the PBP5 nonproducer phenotype of strain Rev14 . None of the other nucleotide substitutions had any apparent effect on the level of PBP5 synthesized. Infect Dis Clin North Am, 1993 Mar, 7(1), 117 - 33 Aminoglycoside resistant enterococcal endocarditis; Eliopoulos GM; There are few well-documented cases of infective endocarditis due to highly aminoglycoside-resistant enterococci reported to date . Nevertheless, strains with high-level resistance to both streptomycin and gentamicin are now sufficiently common that the number of cases of endocarditis due to these organisms will undoubtedly continue to increase . Serious efforts to develop appropriate alternative treatment strategies are now clearly necessary . All high-level gentamicin-resistant bloodstream isolates from patients with suspected or proven endocarditis should be screened for high-level streptomycin resistance . Because these two resistance traits are mediated by distinct genetic elements, a significant minority of highly gentamicin-resistant enterococci will be susceptible to synergistic killing by combinations of cell wall-active antibiotics with streptomycin . For strains highly resistant to both aminoglycosides, there is no evidence of benefit from use of these toxic antimicrobials, and treatment with a cell wall-active agent alone is warranted . Based on older literature and animal models, perhaps as many as 40% to 50% of cases of enterococcal endocarditis might be curable by such regimens . Alternative combinations using a cell wall-active antibiotic together with a fluoroquinolone or rifampin cannot be specifically recommended based on any firm data from the literature, but possible merits of such combinations can be explored in vitro under appropriate circumstances . For ampicillin- and vancomycin-susceptible strains, ampicillin would seem preferable because this drug typically demonstrates greater bactericidal activity in vitro as a single agent . Consideration could be given to administration of ampicillin by continuous intravenous infusion . Several animal studies indicating effectiveness of penicillins for enterococcal endocarditis have used dosing regimens resulting in sustained serum levels . It is unknown whether these observations are relevant to human enterococcal infections . Testing for beta-lactamase production should be undertaken if penicillins are to be used . For strains that are resistant to achievable concentrations of penicillins, or when the patient is intolerant of beta-lactams, vancomycin can be used . In animal models, teicoplanin has appeared to be superior to vancomycin, but high concentrations must be attained . This drug is not yet approved for clinical use, however, and it is unclear if any advantage would exist in treatment of human infections . The recent emergence of enterococci which are resistant to glycopeptides has introduced another potential complicating factor; some of these are also substantially resistant to beta-lactams as well . In some reports, favorable interactions between vancomycin and beta-lactams have been observed against vancomycin-resistant strains.(ABSTRACT TRUNCATED AT 400 WORDS) Postgrad Med, 1993 Feb 15, 93(3), 121 - 4, 127-8 Enterococcal infections . The increasing threat of nosocomial spread and drug resistance; Vemuri RK et al.; Enterococcal nosocomial infections are becoming more common . Their multiple resistance mechanisms to various antibiotics pose serious therapeutic problems . Despite 40 years of intense development of antimicrobial agents, no agent surpasses the synergistic effects of a combination of a penicillin or vancomycin plus an aminoglycoside for treatment of enterococcal infections . New agents that have bactericidal activity against enterococci are needed as the incidence of resistant strains increases. Diagn Microbiol Infect Dis, 1993 Feb, 16(2), 145 - 8 Prevalence of enterococcal high-level aminoglycoside resistance in Japan . Comparative detection by three methods; Chiew YF et al.; A total of 250 strains of enterococci isolated in Kumamoto University Hospital, Japan, during the period from January to March 1992 were tested for high-level aminoglycoside resistance . Brain-heart infusion (BHI) agar plates supplemented with 1000 micrograms/ml of gentamicin or 2000 micrograms/ml of streptomycin detected 164 (66%) isolates resistant to either gentamicin or streptomycin alone, or both, and consisted of 107 (43%) resistant to gentamicin and 96 (38%) resistant to streptomycin . The Vitek Gram-Positive Susceptibility card (GPS-TA) revealed high correlations with those by agar screens, the results indicating a sensitivity of 100% and 99% to gentamicin and streptomycin, respectively, and 100% specificity to both . Also, the microdilution tests of the National Committee for Clinical Laboratory Standards (NCCLS) showed 100% and 92% sensitivity to gentamicin and streptomycin, respectively, and no false resistance (100% specificity) when compared with the results by agar screens. J Antimicrob Chemother, 1993 Feb, 31(2), 227 - 35 The activity of daptomycin on Enterococcus faecium protoplasts: indirect evidence supporting a novel mode of action on lipoteichoic acid synthesis; Boaretti M et al.; The effect of daptomycin, an acidic lipopeptide antibiotic active against Gram-positives, was studied in Enterococcus faecium protoplasts . This antibiotic killed 99% of the protoplasts within 60 minutes of treatment, while vancomycin was ineffective, thus excluding peptidoglycan synthesis as the only target of the action of daptomycin . As previously seen with whole cells, in protoplasts lipoteichoic acid synthesis was the earliest and most strongly inhibited among types of macro-molecular synthesis . Radioactive daptomycin tightly bound only to the cytoplasmic membrane, in which the enzymes involved in lipoteichoic acid synthesis are located . These conclusions strongly support our previous proposal that daptomycin, though active against peptidoglycan synthesis, primarily inhibits lipoteichoic acid synthesis. Arch Tierernahr, 1993, 45(1), 49 - 55 Influence of Avotan on the microflora and concentrations of ammonia and volatile fatty acids in the rumen; Sommer A et al.; The influence of Avotan (Firm Cyanamid) was studied on VFA concentration, pH, dynamics of NH3 and on numbers of chosen species of rumen microorganisms in physiological experiments with four young bulls and two wethers with rumen cannulas . It was found no marked physiological change in pH of rumen fluid under the influence of Avotan . Difference between groups were statistical significant . Avotan caused significant (P < or = 0.01) decrease of molar % of acetic acid (from 67.0 to 62.1) and an increase of propionic acid (from 16.41 to 28.21 mol %) in wethers . These changes were nonsignificant with bulls . The acetate: propionate ratio decreased significantly from 4.1 to 2.2 in wethers . Avotan decreased highly significantly (P < or = 0.01) the level of NH3 in the rumen fluid during the observed period (0, 1.5, 3, 4.5 and 6 hours after feeding) in bulls . It was observed the similar effect in wethers 3 hours after feeding (from 170 mmol to 81 mmol/l) . Decrease of the total number of microorganisms in the rumen fluid was observed in animals which received Avotan (on the average 3.5 times in young bulls, and 4.5 times in wethers) . The number of enterococci decreased significantly (2.8-4.5 times), number of amylolytic bacteria decreased less significantly. Avian Dis, 1993 Jan-Mar, 37(1), 234 - 9 Enterococcus durans infection in young chickens associated with bacteremia and encephalomalacia; Cardona CJ et al.; Two unrelated flocks of chicks experienced elevated mortality from 4 to 10 days of age . Clinical signs in affected birds included a full range of neurological disorders . Livers and spleens were grossly enlarged at necropsy . Enterococcus durans was isolated from multiple organs, including brains . Histologically, there were multifocal coagulative necrosis in the liver, areas of malacia in brain stem, and cerebellar white matter . Inoculation of 1-day-old chicks with a suspension of E . durans resulted in bacteremia but did not produce the lesions observed in field cases. Int J Syst Bacteriol, 1993 Jan, 43(1), 63 - 8 A new approach to use of bacteriolytic enzymes as a tool for species identification: selection of species-specific indicator strains with bacteriolytic activity towards Enterococcus strains; Berlutti F et al.; We describe the bacteriolytic activity of 377 group D Enterococcus isolates expressed towards 25 Enterococcus strains belonging to different species and Micrococcus luteus ATCC 4698 . Of the 26 indicator strains used to reveal bacteriolytic activity, 5 were lysed by all of the strains of some species and were not lysed by all of the strains of other species . The use of these indicator strains allowed us to devise a new method to differentiate group D Enterococcus strains, based on qualitative analysis (lysis or no lysis of the indicator strains) of bacteriolytic activity . The bacteriolytic patterns obtained fell into six bacteriolytic groups corresponding (98% agreement) to species or groups of enterococci as determined by a comparison with data from a phenetic similarity study. Diagn Microbiol Infect Dis, 1993 Jan, 16(1), 89 - 91 Comparison of Streptex versus PathoDx for group D typing of vancomycin-resistant Enterococcus; Truant AL et al.; Vancomycin-resistant enterococci recently isolated from patient specimens were tested with both Streptex and PathoDx group D latex agglutination antisera . Using routine protocols, all isolates from patients at Temple University Hospital were positive with the PathoDx reagents and were negative with the Streptex reagents . Isolates required extensive boiling for positive reactions to occur using Streptex reagents. Diagn Microbiol Infect Dis, 1993 Jan, 16(1), 83 - 5 In vitro activity of nine fluoroquinolone antibiotics against 200 strains of enterococci; Murray PR et al.; The in vitro activity of nine fluoroquinolones against 200 recent clinical isolates of enterococci was evaluated . The relative activity was WIN57273 > sparfloxacin > ciprofloxacin, temafloxacin > ofloxacin > fleroxacin, lomefloxacin, norfloxacin > enoxacin . Susceptibility to gentamicin or streptomycin did not influence the activity of the fluoroquinolones. Obstet Gynecol, 1993 Jan, 81(1), 115 - 7 Single-dose ampicillin prophylaxis does not eradicate enterococcus from the lower genital tract; Graham JM et al.; OBJECTIVES: To determine the carriage rate of enterococcus in the lower genital tract of women having a cesarean delivery and to determine whether a single 2-g intraoperative dose of ampicillin eradicates enterococcus from the lower genital tract . METHODS: Lower genital tract cultures were taken in 84 women who were in labor or had ruptured membranes and who were about to have an indicated cesarean delivery . The subjects were randomized to receive either a single 2-g dose of ampicillin or a cephalosporin as prophylaxis . Cultures were repeated 24 hours postpartum . RESULTS: Enterococcus was isolated preoperatively in 33 subjects (39.3%) and postoperatively in 36 (42.9%) . The enterococcus was eradicated in five of 17 women (29.5%) who received ampicillin . CONCLUSION: These results suggest that a single 2-g dose of ampicillin does not eradicate enterococcus from the lower genital tract. Surg Today, 1993, 23(5), 390 - 5 Bacteriological investigation of bile in patients with cholelithiasis; Ohdan H et al.; The microflora in bile from the gallbladder and common bile duct was investigated in 303 patients who underwent surgery for cholelithiasis . The purpose of this study was to identify current bacteria and bacterial casts in the biliary tract and also to analyze the relationship between bactericholia at the time of operation and postoperative infection . Bile cultures were positive in 38% of all patients, although a higher incidence of positive bile cultures occurred in patients over 70 years of age (77%), those with common duct stones (83%), those with pigment stones (65%), and those who underwent gastrectomy (71%) . The predominant organisms were Escherichia coli (22%), Klebsiella (18%), and Enterococcus (15%) . Obligate anaerobes were less frequently seen (4%), being found only in patients with pigment stones and always mixed with aerobes . Four patients developed postoperative infections (1.3%) which were all caused by biliary bacteria . The following two factors may contribute to this low incidence of postoperative infections: our policy of operating electively whenever possible, and the prophylactic use of antibiotics to which the organisms cultured from bile are sensitive. Surg Gynecol Obstet, 1993, 177 Suppl, 23 - 9; discussion 35-40 A randomized study of cefepime versus the combination of gentamicin and mezlocillin as an adjunct to surgical treatment in patients with acute cholecystitis; Yellin AE et al.; In patients with acute cholecystitis, antibiotics are used as an adjunct to cholecystectomy to reduce the incidence of postoperative septic complications thought to be related to bactibilia . Combinations of penicillins, or cephalosporins or aminoglycosides, or both, are often used . Cefepime is a fourth-generation cephalosporin with excellent activity against gram-positive and gram-negative bacteria, including Pseudomonas species . It has a prolonged serum half-life, allowing twice-daily dosing, and is not nephrotoxic . This study was undertaken to determine whether or not cefepime was as effective as the combination of gentamicin and mezlocillin in patients with acute cholecystitis . One hundred and forty-nine patients were randomized, two to one, to receive cefepime or gentamicin and mezlocillin . Cefepime was given intravenously at 2 grams every 12 hours; gentamicin, 1.0 to 1.5 milligrams per kilograms every eight hours, and mezlocillin, 3 to 4 grams every four to six hours . All patients underwent cholecystectomy . Bile cultures were obtained, and concentrations of cefepime in blood, bile, peritoneal fluid and gallbladder were determined in a subset of patients . There were 56 evaluable cefepime-treated and 34 evaluable gentamicin and mezlocillin-treated patients . Bactibilia was present in 17 of 56 cefepime-treated patients (30.4 percent) and ten of 34 gentamicin and mezlocillin-treated patients (29.4 percent) . Enterococci were recovered in six cefepime-treated patients . Clinical and bacteriologic responses were similar for the cefepime-treated and gentamicin and mezlocillin-treated groups, with one failure in each group, a wound infection in a patient receiving cefepime and a subhepatic abscess in a patients receiving gentamicin and mezlocillin . Other measures of outcome, such as the number of days of fever, days nothing by mouth, days of hospitalization and days of antibiotic therapy were similar in both groups . Cefepime, with every 12 hour dosing, achieved extremely high concentrations in all tissues assayed at the time of the operation, a mean of eight hours after administration . Adverse clinical events were similar in both treatment groups . Cefepime is as effective as gentamicin and mezlocillin in preventing septic complications after cholecystectomy for acute cholecystitis . Cefepime requires fewer doses, does not require drug monitoring, is not associated with nephrotoxicity and may therefore prove to be a cost-effective alternative to combination therapy that uses an aminoglycoside. FEMS Microbiol Lett, 1992 Dec 15, 79(1-3), 261 - 7 The autolytic ('suicidase') system of Enterococcus hirae: from lysine depletion autolysis to biochemical and molecular studies of the two muramidases of Enterococcus hirae ATCC 9790; Shockman GD; Autolysis of Enterococcus hirae ATCC 9790 is the result of the action of endogenous enzymes that hydrolyze bonds in the protective and shape-maintaining cell wall peptidoglycan . It is thought that these potentially suicidal enzymes play a positive role(s) in wall growth and division and are expressed as autolysins when cell wall assembly and/or repair are inhibited . E . hirae possesses two potentially autolytic enzymes, both of which are muramidases . Although they hydrolyze the same bond as hen egg-white lysozyme, both are high-molecular-mass, complex enzymes . Muramidase-1 is synthesized as a zymogen, requiring protease activation . It is a glucoenzyme that is also multiply nucleotidylated with an unusual nucleotide, 5-mercaptouridine monophosphate . Muramidase-2 is almost certainly a product of a separate gene . The deduced amino acid sequence of a cloned gene for extracellular muramidase-2 showed several unusual features . It appears to be a two-, or perhaps three-domain protein with a putative glycosidase-active site near the N-terminal end and six 45-amino-acid-long repeats at the C-terminal end which are presumed to be involved with high-affinity binding to the insoluble peptidoglycan substrate . Muramidase-2 binds penicillin with low affinity . The presence of several amino acid groupings characteristic of serine-active site beta-lactam-interactive proteins is consistent with the possible presence of a penicillin-binding, third domain . Indirect evidence consistent with a role(s) for these enzymes in cell wall growth and division has been obtained . However, proof of such role(s) awaits modern genetic, molecular, and biochemical analyses. Acta Ophthalmol (Copenh), 1992 Dec, 70(6), 842 - 3 Enterococcal endophthalmitis following cataract extraction, treated with ampicillin intravitreally; Ejdervik-Lindblad B et al.; A case of Enterococcal endophthalmitis developed following an extracapsular cataract extraction . The infection was successfully treated with intravenous and intravitreal ampicillin, but a secondary glaucoma led to a later enucleation . We report a case of postoperative endophthalmitis with an unusual etiology, which did not respond to common treatment. Lab Anim Sci, 1992 Dec, 42(6), 548 - 50 Diarrhea caused by a slow-growing Enterococcus-like agent in neonatal rats; Etheridge ME et al.; An enteropathogenic Enterococcus-like agent was isolated from a spontaneous outbreak of diarrhea that occurred in a colony containing neonatal rats . Diarrhea was experimentally reproduced in virus-antibody-free neonatal rats inoculated with this purified "enterococcus." Gram-positive cocci were adhered to the small intestinal villi of affected animals from which the organism was reisolated . The isolate's classification in the genus Enterococcus was confirmed by genetic probe; however, because of its unique fermentation pattern, it could not be definitively speciated . Indirect immunofluorescence assays indicate that this strain of enterococcus and Enterococcus hirae, another strain pathogenic for neonatal rats, differ antigenically . Enterococci should be considered as potential etiologic agents in outbreaks of diarrhea involving neonatal rats and future efforts directed to increasing our understanding of the pathophysiology of this disease. Antimicrob Agents Chemother, 1992 Dec, 36(12), 2611 - 6 Daptomycin or teicoplanin in combination with gentamicin for treatment of experimental endocarditis due to a highly glycopeptide-resistant isolate of Enterococcus faecium; Caron F et al.; Using an experimental endocarditis model, we studied the activity of daptomycin used alone or in combination with gentamicin against an Enterococcus faecium strain that was highly resistant to glycopeptides and susceptible to gentamicin . In vitro, the MIC of daptomycin was 1 micrograms/ml . In vivo, daptomycin appeared to be effective only when it was used in a high-dose regimen, i.e., 12 mg/kg of body weight every 8 h (-2.5 log10 CFU/g versus controls; P < 0.05), particularly when it was combined with gentamicin (-5.0 log10 CFU/g versus controls; P < 0.01) . Since the distribution of daptomycin into cardiac vegetations, as evaluated by autoradiography, appeared to be homogeneous, the poor in vivo activity of daptomycin was considered to be related to its high degree of protein binding, as suggested by killing curves studies . Since the MIC of teicoplanin for the vancomycin-resistant E . faecium strain used in the study was only 64 micrograms/ml and since an in vitro synergy between teicoplanin at high dose and gentamicin was observed, a high-dose regimen of teicoplanin, i.e., 40 mg/kg every 12 h, was also assessed in vivo . This treatment provided marginal activity only when it was combined with gentamicin (-2.3 log10 CFU/g versus controls; P < 0.05) . These results suggest that the levels of daptomycin or teicoplanin in serum required to cure experimental endocarditis caused by a highly glycopeptide-resistant strain of E . faecium would not be achievable in humans. Infect Control Hosp Epidemiol, 1992 Dec, 13(12), 700 - 5 Vancomycin-resistant Enterococcus faecium in hospitalized children; Rubin LG et al.; OBJECTIVE: Determine the epidemiology and risk factors for colonization with vancomycin-resistant Enterococcus faecium . DESIGN: Survey; case-control study . SETTING: Children's hospital . PATIENTS: Pediatric oncology patients . INTERVENTION: Contact isolation, restriction of vancomycin prescribing . RESULTS: There was a high prevalence of colonization with vancomycin-resistant enterococci among pediatric oncology patients . The length of hospitalization and the administration of vancomycin and other intravenous antibiotics was associated with colonization . Prevention of colonization was associated with restriction of vancomycin use and contact isolation . CONCLUSIONS: Vancomycin use may predispose to colonization with vancomycin-resistant E faecium . Vancomycin-resistant E faecium may be nosocomially spread . Contact isolation and restriction of vancomycin use may prevent spread of vancomycin-resistant E faecium. FEMS Microbiol Lett, 1992 Nov 1, 77(1-3), 109 - 15 Biosynthesis of modified peptidoglycan precursors by vancomycin-resistant Enterococcus faecium; Allen NE et al.; In the presence of bacitracin, vancomycin-resistant Enterococcus faecium (vanA phenotype) accumulate UDP-N-acetylmuramyl(UDP-Mur-NAc)-tetrapeptide and a UDP-MurNAc-depsipentapeptide containing lactate substituted for the carboxy-terminal-D-alanine residue . In an in vitro peptidoglycan polymerization assay, the modified precursors function and confer resistance to vancomycin. Antimicrob Agents Chemother, 1992 Nov, 36(11), 2533 - 5 Increasing resistance of enterococci to ciprofloxacin; Schaberg DR et al.; We determined that resistance to ciprofloxacin has emerged in enterococci over the last 5 years in our hospital, mainly in strains demonstrating the phenotype of high-level gentamicin resistance . All high-level-gentamicin-resistant isolates from 1985 and 1986 were susceptible, whereas 24% of isolates from 1989 and 1990 were resistant to ciprofloxacin . Plasmid and genomic DNA typing showed at least six unique strains exhibiting resistance, but one type accounted for 80% of recent resistant isolates, suggesting a role for cross infection in the emergence of resistance.
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