Clin Infect Dis, 2001 May 1, 32(9), 1373 - 5 Epub 2001 Apr 09. Successful treatment of vancomycin-resistant Enterococcus endocarditis with oral linezolid; Babcock HM et al.; We report a case of vancomycin-resistant Enterococcus faecium endocarditis that failed to respond to sequential monotherapy with chloramphenicol and quinupristin/dalfopristin but was successfully treated with oral linezolid. Antimicrob Agents Chemother, 2001 May, 45(5), 1480 - 6 Penicillin-binding protein 5 and expression of ampicillin resistance in Enterococcus faecium; Rice LB et al.; We report a structural and transcriptional analysis of the pbp5 region of Enterococcus faecium C68 . pbp5 exists within a larger operon that includes upstream open reading frames (ORFs) corresponding to previously reported psr (penicillin-binding protein synthesis repressor) and ftsW (whose product is a transmembrane protein that interacts with PBP3 in Escherichia coli septum formation) genes . Hybridization of mRNA from C68, CV133, and four ampicillin-resistant CV133 mutants revealed four distinct transcripts from this region, consisting of (i) E . faecium ftsW (ftsW(Efm)) alone; (ii) psr and pbp5; (iii) pbp5 alone; and (iv) ftsW(Efm), psr, and pbp5 . Quantities of the different transcripts varied between strains and did not always correlate with quantities of PBP5 or levels of ampicillin resistance . Since the psr of C68 is presumably nonfunctional due to an insertion of an extra nucleotide in the codon for the 44th amino acid, the region extending from the ftsW(Efm) promoter through the pbp5 gene of C68 was cloned in E . coli to facilitate mutagenesis . The psr ORF was regenerated using site-directed mutagenesis and introduced into E . faecium D344-SRF on conjugative shuttle vector pTCV-lac (pCWR558 {psr ORF interrupted}; pCWR583 {psr ORF intact}) . Ampicillin MICs for both D344-SRF(pCWR558) and D344-SRF(pCWR583) were 64 microg/ml . Quantities of pbp5 transcript and protein were similar in strains containing either construct regardless of whether they were grown in the presence or absence of ampicillin, arguing against a role for PSR as a repressor of pbp5 transcription . However, quantities of psr transcript were increased in D344-SRF(pCWR583) compared to D344-SRF(pCWR558), especially after growth in ampicillin; suggesting that PSR acts in some manner to activate its own transcription. Antimicrob Agents Chemother, 2001 May, 45(5), 1394 - 401 In vivo efficacy of trovafloxacin against Bacteroides fragilis in mixed infection with either Escherichia coli or a vancomycin-resistant strain of Enterococcus faecium in an established-abscess murine model; Stearne LE et al.; The pharmacodynamic and pharmacokinetic properties of trovafloxacin were studied in a standardized murine model of established subcutaneous abscesses . Daily dosing regimens of 37.5 to 300 mg/kg every 8 h (q8h) or every 24 h (q24h) were started 3 days after inoculation with mixtures containing either Bacteroides fragilis-Escherichia coli-autoclaved cecal contents (ACC) or B . fragilis-vancomycin-resistant Enterococcus faecium (VREF)-ACC . Treatment was continued for 3 or 5 days . The efficacy of treatment was determined by the decrease in abscess bacterial counts and abscess weights, as well as by the reduction in inflammation (biodistribution of (99m)Tc-HYNIC immunoglobulin G) compared to saline-treated controls . Trovafloxacin showed a significant dose-response effect on the bacterial counts, weight, and inflammation of B . fragilis-E . coli abscesses after 3 and/or 5 days of treatment . A maximum 3.4 and 3.1 log(10) reduction in CFU/abscess in the respective B . fragilis and E . coli bacterial counts was attained after 5 days of treatment with daily doses of 300 mg/kg . The peak serum concentration was more predictive for effect than the area under the concentration-time curve . The C(max) was the pharmacodynamic index most predictive for success, and the efficacy of the q24h regimens was significantly better than the q8h regimens . The antibiotic was ineffective against the VREF in mixed infection with B . fragilis, while the killing of the anaerobe in the same combination was significantly less than in the E . coli combination (P < 0.05) . We conclude that this is a useful model for studying the activity of antimicrobials for the treatment of small (<1-cm), undrainable, mixed-infection abscesses . In addition, we have shown for the first time that a decrease in bacterial numbers also leads to a reduction in both abscess weight and inflammation. Emerg Infect Dis, 2001 Mar-Apr, 7(2), 183 - 7 Emergence of vancomycin-resistant enterococci; Rice LB; Vancomycin and ampicillin resistance in clinical Enterococcus faecium strains has developed in the past decade . Failure to adhere to strict infection control to prevent the spread of these pathogens has been well established . New data implicate the use of specific classes of antimicrobial agents in the spread of vancomycin-resistant enterococci (VRE) . Extended-spectrum cephalosporins and drugs with potent activity against anaerobic bacteria may promote infection and colonization with VRE and may exert different effects on the initial establishment and persistence of high-density colonization . Control of VRE will require better understanding of the mechanisms by which different classes of drugs promote gastrointestinal colonization. Clin Microbiol Infect, 2001 Jan, 7(1), 17 - 21 Chloramphenicol treatment for vancomycin-resistant Enterococcus faecium bacteremia; Ricaurte JC et al.; OBJECTIVE: To evaluate the results of treating vancomycin-resistant Enterococcus faecium (VREF) bacteremia with chloramphenicol . METHODS: We retrospectively reviewed the charts of all adult patients with VREF bacteremia treated with chloramphenicol during the calendar year 1998 at a 522-bed tertiary referral center in New York City . Patients were identified by reviewing microbiology laboratory records . Patients with clinically significant VREF bacteremia who received chloramphenicol for at least 48 h were included in the study . Clinical and microbiological outcomes were determined . Microbiological and molecular tests were performed on a small representative sample of isolates to identify the presence of resistance mechanisms and to look for similarity among the isolates . RESULTS: Seven episodes of significant VREF bacteremia occurred in six patients . Mean age was 54 years . All patients had cancer and three had severe neutropenia . Five of seven episodes were associated with chronic indwelling devices, but in only one of these cases was the device removed . All isolates were susceptible to chloramphenicol in vitro . All six microbiologically evaluable episodes had a favorable response to chloramphenicol treatment, and four of seven (57%) clinically evaluable episodes had favorable outcomes . Only one death may have been due to VREF bacteremia, so the maximal attributable mortality was 14% . The three representative samples that were tested further were indistinguishable from one another and they displayed no evidence of resistance mechanisms . CONCLUSIONS: In a cohort of severely ill cancer patients, chloramphenicol was effective in treating VREF bacteremia . The use of chloramphenicol should be considered in treating infections with this highly resistant organism, where therapeutic options are limited. South Med J, 2001 Mar, 94(3), 353 - 5 Vancomycin-resistant Enterococcus faecium osteomyelitis: successful treatment with quinupristin-dalfopristin; Summers M et al.; Vancomycin-resistant enterococci (VRE) have recently emerged as an increasing concern in the management of severe infections . Treatment of these life-threatening infections has been limited to quinupristin-dalfopristin and, more recently, linezolid therapy . We report the first case, to our knowledge, of vancomycin-resistant Enterococcus faecium vertebral osteomyelitis treated successfully with quinupristin-dalfopristin . We review the recent epidemiology of VRE and briefly outline the pharmacology and pharmacokinetics of quinupristin-dalfopristin. J Clin Microbiol, 2001 Apr, 39(4), 1678 - 9 Vertebral osteomyelitis caused by Enterococcus raffinosus; Sandoe JA et al.; Enterococcus raffinosus is a rare isolate in clinical specimens . A case of vertebral osteomyelitis caused by E . raffinosus in an elderly patient is described and confirms this organism to be an opportunistic human pathogen. Protein Sci, 2001 Apr, 10(4), 836 - 44 Sequencing of the ddl gene and modeling of the mutated D-alanine:D-alanine ligase in glycopeptide-dependent strains of Enterococcus faecium; Gholizadeh Y et al.; Glycopeptide dependence for growth in enterococci results from mutations in the ddl gene that inactivate the host D-Ala:D-Ala ligase . The strains require glycopeptides as inducers for synthesis of resistance proteins, which allows for the production of peptidoglycan precursors ending in D-Ala-D-Lac instead of D-Ala-D-Ala . The sequences of the ddl gene from nine glycopeptide-dependent Enterococcus faecium clinical isolates were determined . Each one had a mutation consisting either in a 5-bp insertion at position 41 leading to an early stop codon, an in-frame 6-bp deletion causing the loss of two residues (KDVA243-246 to KA), or single base-pair changes resulting in an amino acid substitution (E13 --> G, G99 --> R, V241 --> D, D295 --> G, P313 --> L) . The potential consequences of the deletion and point mutations on the 3-D structure of the enzyme were evaluated by comparative molecular modeling of the E . faecium enzyme, using the X-ray structure of the homologous Escherichia coli D-Ala:D-Ala ligase DdlB as a template . All mutated residues were found either to interact directly with one of the substrates of the enzymatic reaction (E13 and D295) or to stabilize the position of critical residues in the active site . Maintenance of the 3-D structure in the vicinity of these mutations in the active site appears critical for D-Ala:D-Ala ligase activity. Microb Drug Resist, 2000 Winter, 6(4), 327 - 30 Effectiveness of a vancomycin restriction policy in changing the prescribing patterns of house staff; Richardson LP et al.; After noting a rise in vancomycin-resistant enterococci (VRE) infections, we initiated a program to decrease inappropriate vancomycin use that focused on improvement of house staff prescribing practices . The initial intervention in June, 1995, encouraging house staff to follow hospital guidelines for vancomycin use and eliciting support from service chiefs in this effort, had little impact . A more intensive educational intervention, beginning in January, 1996, involved concurrent review of all vancomycin orders and one-on-one discussion with the house staff regarding the rationale for the order by an infectious diseases clinical pharmacist . When usage was deemed inappropriate, the pharmacist asked that vancomycin be discontinued, but no automatic stop orders were issued . During the next two and one-half years, this second intervention proved effective at decreasing inappropriate use from 39% to 16.8% +/- 2.4% (p = 0.005) . This change was primarily due to a decrease in appropriate vancomycin prophylaxis by cardiothoracic surgery . VRE infections decreased from 0.29/100 patients discharged prior to initiating the program to 0.13/100 patients discharged after the second intervention (p = 0.01) . This educational program, although labor-intensive, preserved house staff decision-making skills related to antibiotic prescribing at the same time that it decreased inappropriate vancomycin use. Microb Drug Resist, 2000 Winter, 6(4), 305 - 11 Streptogramin resistance and shared pulsed-field gel electrophoresis patterns in vanA-containing Enterococcus faecium and Enterococcus hirae isolated from humans and animals in Spain; Robredo B et al.; The present study was performed to determine if any of the 45 vanA-containing Enterococcus faecium or 18 vanA-containing E . hirae strains were shared by chickens (32 E . faecium/l7 E . hirae) and humans (13 E . faecium/1 E . hirae) using pulsed field gel electrophoresis (PFGE) and to study quinupristin-dalfopristin (Q-D) resistance . Seven of the 45 E . faecium isolates (from 2 outpatients and from 5 poultry products) were resistant to Q-D (MIC > or = 16 microg/ml); one strain was shown to have satA by PCR and sequencing and, in the other six isolates, the recently described satG gene was demonstrated . Six different PFGE patterns were detected among the 7 Q-D E . faecium-resistant isolates . None of the E . hirae isolates showed Q-D resistance . Among the 45 vanA -containing E . faecium strains, 25 unrelated clones were found by PFGE with highly diverse patterns and an indistinguishable PFGE pattern was observed in vanA-containing E . faecium strains from two humans and two poultry products . A single PFGE pattern was detected in 17 of 18 vanA-containing E . hirae isolates, obtained from one human and 16 chicken samples . Based on the presence of indistinguishable PFGE patterns among VR E . faecium and E . hirae from humans and chickens, we conclude that horizontal transfer of these strains could occur between both groups. Fish Shellfish Immunol, 2001 Jan, 11(1), 53 - 63 Effects of intrinsic and extrinsic factors on the haemocyte profile of the prawn, Macrobrachium rosenbergii; Cheng W et al.; The giant freshwater prawn Macrobrachium rosenbergii was investigated for its total haemocyte count (THC) based on season, sex, size and feeding rate . The THC, when the prawns were subjected to injections of foreign materials was also investigated . The prawns displayed the highest and lowest THC in autumn and winter respectively, with no significant difference between male and female, or among animals with a body weight range of 7-115 g . The prawns displayed the lowest THC at D3 stage, and the highest in C stage . The prawns displayed the lowest THC when they were fed at 0.1% feeding rate among feeding rates of 0.1%, 0.5%, 1.0% and 1.5% body weight x day(-1) . Prawns injected with carbon powder and Enterococcus showed increased THC during the first 6 h . Prawns injected with saline and carbon powder had the lowest THC after 30 h, and recovered to the normal value after 54 h . Prawns injected with Enterococcus showed the lowest THC after 42 h, and showed delayed recovery. Arch Microbiol, 2001 Jan, 175(1), 41 - 5 Potassium uptake with low affinity and high rate in Enterococcus hirae at alkaline pH; Kawano M et al.; Two high-affinity K+ uptake systems, KtrI and KtrII, have been reported in Enterococcus hirae . A mutant, JEMK1, defective in these two systems did not grow at pH 10 in low-K+ medium (less than 1 mM K+), but grew well when supplemented with 10 mM KCl . In this mutant, we found an energy-dependent K+ uptake at pH 10 with a low affinity for K+ (Km of approximately 20 mM) and an extremely high rate {Vmax of 1.6 micromol x min(-1) (mg protein)(-1)} . Rb+ uptake {Km of approximately 40 mM and Vmax of 0.5 micromol x min(-1) (mg protein)(-1)}, which was inhibited competitively by K+ and less prominently by Cs+, was also observed . The specificity of this transport is likely to be K+>Rb+>Cs+ . This peculiar K+ transport plays a role as a salvage mechanism against defects in high-affinity systems in the K+ homeostasis of this bacterium. Lancet, 2001 Mar 17, 357(9259), 853 - 5 Variant esp gene as a marker of a distinct genetic lineage of vancomycin-resistant Enterococcus faecium spreading in hospitals; Willems RJ et al.; In the USA, vancomycin-resistant Enterococcus faecium (VREF) is endemic in hospitals, despite lack of carriage among healthy individuals . In Europe, however, hospital outbreaks are rare, but VREF carriage among healthy individuals and livestock is common . We used amplified fragment-length polymorphism analysis to genotype 120 VREF isolates associated with hospital outbreaks and 45 non-epidemic isolates from the USA, Europe, and Australia . We also looked for the esp virulence gene in these isolates and in 98 VREF from animals . A specific E . faecium subpopulation genetically distinct from non-epidemic VREF isolates was found to be the cause of the hospital epidemics in all three continents . This subpopulation contained a variant of the esp gene that was absent in all non-epidemic and animal isolates . Identification of the variant esp gene will be important in guiding infection-control strategies, and the Esp protein could be a new target for antibacterial therapy. Pathol Biol (Paris), 2001 Feb, 49(1), 23 - 32 {Evaluation of 7 endoscope washer-disinfectors: bactericidal activity of the disinfectants, antibacterial efficacity of paired washer-disinfector products}; Dusseau JY et al.; The authors studied seven automatic washer disinfectors for flexible endoscopes with two methods . The first method, a microdilution method, studied the bactericidal activity of the seven disinfectants against 21 strains: four reference strains, 14 hospital strains reported in the literature as nosocomial strains responsible for infections transmitted by flexible endoscopes and three vancomycin-resistant Enterococci . The ability of the seven automatic washer disinfectors to decontaminate flexible endoscopes following inoculation with four reference strains was studied with the second method . There were three kinds of results: the results of three automatic washer disinfectors in conformity with both methods; the results of three automatic washer disinfectors conformity with 1 method only; the results of one automatic washer disinfector without conformity with any methods . Both methods should be used for evaluation of automatic washer disinfector . Then, these results emphasize the necessity to modify the use of disinfectants and/or the systems of some automatic washer disinfectors. Rev Esp Cardiol, 2001 Mar, 54(3), 402 - 4 {Isolated pulmonary endocarditis on native valve in elderly patient without predisposing factors}; Perez-Paredes M et al.; Isolated infective endocarditis in the native pulmonary valve is an unusual clinical entity in patients without predisposing factors and in non-intravenous drugs users . We present the case of a 75-year-old patient, with a subacute clinical picture of fever and pulmonary cavity nodules, admitted to our hospital with an initial suspected diagnosis of pulmonary tuberculosis . The presence of Enterococcal bacteremia in hemocultive and the documentation of a large vegetation in pulmonary valve by transtoracic and transesophageal echocardiography were key factors for final diagnosis. Antimicrob Agents Chemother, 2001 Apr, 45(4), 1309 - 11 Diversity of Tn1546 elements in clinical isolates of glycopeptide-resistant enterococci from Scottish hospitals; Brown AR et al.; The Tn1546-related elements of 48 Van glycopetide-resistant enterococci were compared . Ten distinct Tn1546 types were identified with variation primarily due to IS1542 and IS1216V-like insertions . Clonal isolates frequently differed in their Tn1546 type, indicating instability of Tn1546-related elements . A putative hybrid promoter was identified, generated upstream of vanR by the insertion of IS1542 . The presence of this hybrid promoter was associated with constitutive expression of the van genes and elevated teicoplanin resistance. J Antimicrob Chemother, 1999 Feb, 43(2), 261 - 6 The control of hyperendemic glycopeptide-resistant Enterococcus spp . on a haematology unit by changing antibiotic usage; Bradley SJ et al.; The rectal carriage of glycopeptide-resistant Enterococcus spp . (GRE) had been established at approximately 50% in a series of prevalence studies on a busy haematological malignancy unit . The aim of this study was to reduce the chance of patients acquiring GRE . A prospective three-phase sequential study was performed . In Phase 1, the acquisition rate of GRE detectable by rectal swab was measured without any intervention for a period of 4 months . For the following 8 months (Phase 2), the first-line treatment for febrile neutropenic episodes was changed from monotherapy with ceftazidime to piperacillin/tazobactam . In addition, an intense education programme was introduced to improve hygiene to reduce the risk of case-to-case spread . In the final 4 months (Phase 3), ceftazidime was again used as the first-line antimicrobial, while continuing the same level of training in relation to hygiene . The carriage of GRE was measured from rectal swabs done weekly . During the initial 4 months, at any time, 40-50% of patients in the unit were colonized with GRE, and 43 of 75 (57%) new patients initially negative for GRE acquired it within 6 weeks of their admission . In Phase 2, 25 patients out of 129 (19%) acquired GRE, with the acquisition rate falling progressively so that in the last 3 months, only one new patient acquired GRE (logrank comparison of probabilities for cohort 1 vs cohort 2b: P < 0.0001) . A return to ceftazidime in Phase 3 was associated with a return of the risk of acquiring detectable GRE colonization, despite continued hygiene teaching and surveillance, with 21 out of 58 patients (36%) acquiring GRE (cohort 1 vs cohort 3: P = 0.08) . Glycopeptide usage was not reduced during the period of the study . Clinical cases were seen only in Phases 1 and 3 . Although the reduction in the risk of acquiring GRE may have been due in part to hygiene practices as well as to the change in antimicrobial usage, or may have occurred spontaneously for other reasons, the return of the problem with the reintroduction of ceftazidime strongly suggests that this antibiotic was responsible for encouraging the acquisition of detectable GRE. Mol Microbiol, 2001 Mar, 39(5), 1307 - 20 Dominant-negative mutants of prgX: evidence for a role for PrgX dimerization in negative regulation of pheromone-inducible conjugation; Bae T et al.; PrgX negatively regulates prgQ transcriptional readthrough in the pheromone-inducible enterococcal conjugative plasmid pCF10 . We isolated and characterized 13 dominant-negative prgX mutants, all of which mapped in either the N- or the C-terminus of PrgX . In all mutants, the in vivo level of Qa RNA, an antisense RNA to prgQ RNA, was greatly reduced . When oligomerization of PrgX was tested with a phage lambda cI repressor fusion system, the oligomerization domain was found to be between amino acid residues 78 and 280 . When histidine-tagged PrgX (His-PrgX) was purified by nickel column chromatography from a strain also expressing PrgX, PrgX was co-purified with His-PrgX . Although PrgX was expressed at a much higher level than His-PrgX, an approximately equal amount of PrgX was co-purified . Pheromone induction greatly decreased the co-purification of PrgX . Based on these data, we propose that both the N- and the C-terminal domains of PrgX are required for PrgX positive autoregulation and for the repression of prgQ transcription readthrough . In vivo, PrgX exists as a dimer, and dimerization is mediated by the central region of PrgX. Curr Opin Investig Drugs, 2000 Oct, 1(2), 173 - 80 Synercid Aventis; Pavan B; Rhone-Poulenc Rorer (RPR) developed Synercid (RP-59500), an injectable synergistic combination of quinupristin and dalfopristin as a treatment for a variety of infections caused by Gram-positive anaerobic bacteria . The treatment was approved in the UK in July 1999, for use in patients with nosocomial pneumonia, skin and soft tissue infections and clinically significant infections due to Enterococcus faecium when there is no other active antibacterial agent {337556,335257} . It was launched in the UK and the US in September 1999 {342899} . In December 1999, Synercid successfully completed the Mutual Recognition Procedure in the EU under Aventis Pharma for use in patients with these infections {351525} . In September 2000, Merrill Lynch predicted first-year sales in 1999 of Euro 15 million, rising to Euro 171 million in 2004 {384874} . In January 1999, BT Alex Brown predicted sales of US $88 million in 1999 rising to US $450 million in 2002 {318220} . In April 1999, ABN Amro predicted annual sales of DM 30 million in 1999, rising to DM 150 million in 2002 {328676}. Biochim Biophys Acta, 2001 May 1, 1505(1), 75 - 81 Catalytic properties of Na(+)-translocating V-ATPase in Enterococcus hirae; Murata T et al.; V-ATPases make up a family of proton pumps distributed widely from bacteria to higher organisms . We found a variant of this family, a Na(+)-translocating ATPase, in a Gram-positive bacterium, Enterococcus hirae . The Na(+)-ATPase was encoded by nine ntp genes from F to D in an ntp operon (ntpFIKECGABDHJ): the ntpJ gene encoded a K(+) transporter independent of the Na(+)-ATPase . Expression of this operon, encoding two transport systems for Na(+) and K(+) ions, was regulated at the transcriptional level by intracellular Na(+) as the signal . Structural aspects and catalytic properties of purified Na(+)-ATPase closely resembled those of other V-type H(+)-ATPases . Interestingly, the E . hirae enzyme showed a very high affinity for Na(+) at catalytic reaction . This property enabled the measurement of ion binding to this ATPase for the first time in the study of V- and F-ATPases . Properties of Na(+) binding to V-ATPase were consistent with the model that V-ATPase proteolipids form a rotor ring consisting of hexamers, each having one cation binding site . We propose here a structure model of Na(+) binding sites of the enzyme. Infect Control Hosp Epidemiol, 2001 Feb, 22(2), 116 - 9 Reality check: should we try to detect and isolate vancomycin-resistant enterococci patients? Ostrowsky B, Steinberg JT, Farr B, Sohn AH, Sinkowitz-Cochran RL, Jarvis WR. Antimicrobial resistance, including vancomycin resistance in enterococci (VRE), is a growing problem in healthcare facilities . This "Reality Check" session focused on the question of whether we should try to detect and isolate patients colonized or infected with VRE. J Clin Microbiol, 2001 Mar, 39(3), 1165 - 8 Possible horizontal transfer of the vanB2 gene among genetically diverse strains of vancomycin-resistant Enterococcus faecium in a Korean hospital; Lee WG et al.; A total of 25 isolates of vanB-containing Enterococcus faecium were recovered from patients in a single Korean hospital over a 20-month period . There were two distinct vanB2 patterns among the 11 pulsed-field gel electrophoresis types; 17 contained the prototype vanB2 and 8 contained a novel vanB2 with a 177-bp deletion in vanY(B) . Both vanB2 genes were transmissible in vitro at a mean frequency of 1.1 x 10(-8) transconjugants/donor . These results suggest the horizontal spread of vanB2 is occurring among genetically diverse strains of E . faecium in Korean hospitals. Clin Infect Dis, 2001 Mar 1, 32(5), 826 - 9 Epub 2001 Feb 23. Effectiveness of gloves in the prevention of hand carriage of vancomycin-resistant enterococcus species by health care workers after patient care; Tenorio AR et al.; Gloving reduces acquisition of vancomycin-resistant Enterococcus species (VRE) on the hands, and it should be considered for routine inpatient care, even for contact with the intact skin of patients who may be colonized with VRE . However, gloving does not completely prevent contamination of the hands, and hand washing is necessary after glove removal. Semin Respir Infect, 2000 Dec, 15(4), 314 - 26 Vancomycin-resistant enterococci; McGeer AJ et al.; Over the last 2 decades, enterococci, formerly viewed as organisms of minimal clinical impact, have emerged as important hospital-acquired pathogens in immunosuppressed patients and intensive care units (ICUs) . Vancomycin resistance in enterococci is increasing steadily . Vancomycin-resistant enterococci (VRE) composed 26% of nosocomial enterococci in 1999, a 47% increase from 1994 to 1998 . More that 25% of ICU enterococci are resistant to vancomycin . Antimicrobial therapy is problematic for all VRE, but particularly when bactericidal activity is necessary . Quinipristin-dalfopristin and linezolid are 2 new approved antimicrobials for the treatment of recalcitrant infections caused byVRE . Control of the transmission of VRE, although successful in preventing infections, is neither simple nor inexpensive, and VRE has become endemic in many hospitals . However, endemicity poses serious risks to the health of current and future patients, and of itself, is expensive . Data on the cost-effectiveness of VRE prevention programs are currently lacking and urgently needed; however, because the added cost of a single VRE infection far exceeds those of gowns, gloves, and screening, it seems likely that such control programs represent significant cost savings for those hospitals willing to undertake them. Anal Chem, 2001 Feb 1, 73(3), 444 - 52 Chromatographic interactions between proteins and sulfoalkylbetaine-based zwitterionic copolymers in fully aqueous low-salt buffers; Viklund C et al.; Macroporous monoliths containing N,N-dimethyl-N-methacryloyloxyethyl-N-(3-sulfopropyl)ammonium betaine (SPE) have been synthesized via in situ photopolymerization, yielding a stoichiometric balance between sulfur and nitrogen in the final polymer, which is indicative of a genuine strong/strong zwitterionic character . The chromatographic properties of these zwitterionic resins were evaluated with respect to the retention behavior of inorganic ions and proteins . The weak electrostatic nature of the interaction between the sulfobetaine monoliths and proteins provided a high selectivity between basic proteins and peptides . Elution was accomplished with low-ionic-strength fully aqueous mobile phases, whereby high recovery was obtained, even for hydrophobic proteins . Chaotropic ions such as perchlorate or thiocyanate were used as mobile phase modifiers to modulate the apparent ion exchange group density, thus introducing a route for the modulation of the ionic strength that is required to competitively elute the protein . The promising features of polymeric sulfoalkylbetaine interaction layers for separation and analysis of biological extracts was also manifested in an application involving purification of biologically active peptide-pheromone obtained from Enterococcus faecium. Dig Dis Sci, 2000 Nov, 45(11), 2183 - 6 Enterococcal bactibilia in patients with malignant biliary obstruction; Nomura T et al.; Biliary obstruction due to pancreaticobiliary malignancy is often accompanied by bactibilia . The aims of this study were to clarify the impact of preoperative antibiotic use on bile bacterial flora and to identify the bile bacteria responsible for postoperative septic complications in patients with malignant biliary obstruction . Eighty-four patients with malignant biliary obstruction underwent a biliary decompression procedure before definitive surgery . In 63 patients (75%), preoperative bile culture was positive, with nine species being detected . Only the incidence of enterococcal bactibilia increased after antibiotic use (P = 0.0009), with a 16% incidence before and 63% after antibiotic use . When analyzing the correlation between preoperative bile bacteria and postoperative complications, only the Enterococcus species was associated with the occurrence of complications (P = 0.037) . In conclusion, bile bacterial flora changes after preoperative antibiotic use, with a significant increase in the incidence of enterococcal bactibilia . The Enterococcus species is most responsible for postoperative septic complications in patients with malignant biliary obstruction. J Basic Microbiol, 2000, 40(5-6), 303 - 10 Isolation of an 1,3-1,4-beta-glucan degrading Enterococcus faecium strain from the intestinal tract of chicken and partial characterization of its novel 1,3-1,4-beta-glucanase; Beckmann L et al.; An Enterococcus faecium strain with a novel endo 1,3-1,4-endo-beta-glucanase (lichenase, E.C . 3.2.1.73) was isolated from the intestinal tract of broiler chicken . The enzyme was secreted into the culture medium and acted exclusively on mixed linked 1,3-1,4-beta-glucans as determined with a reducing sugar assay . The purified enzyme has its isoelectric point at pI 4.8, maximum activity was determined at pH 6.5 and 40 degrees C . Thermal stability of the enzyme was low, but high pH stability and high residual activity was observed after incubation in digesta samples from the chicken intestine . Multiple lichenase activities were obtained from culture supernatants on SDS/PAGE and native zymograms, but it is concluded that the lichenase consists of one active protein at 30.5 kD and additional polypeptides of unknown function. Ned Tijdschr Geneeskd, 2000 Dec 30, 144(53), 2572 - 6 {Epidemiologic increase of various genotypes of vancomycin-resistant Enterococcus faecium in a university hospital}; Mascini EM et al.; After a report of a possible relationship between an outbreak of vancomycin-resistant enterococci (VRE) in a nearby hospital and earlier admission of two of the patients with this VRE in the University Medical Centre of Utrecht (UMCU), the Netherlands, an extensive search for VRE carriers was started in the UMCU . In the study period of two months, VRE carriership was diagnosed in 51 patients in nine of the 11 wards investigated . Twenty-six patients in eight wards were colonized with the same VRE genotype as in the nearby hospital; spread was demonstrated in three wards . In addition, six patients of one ward were colonized with a second genotype and seven other patients with a third genotype, while 12 patients were carriers of a unique genotype . Most carriers were found in the internal medicine/nephrology and dialysis ward . Far-reaching measures (such as cohort nursing, admission stops, use of gowns and gloves, disinfection and restriction of use of vancomycin) taken in the four wards where spread was demonstrated, appeared effective but in three wards, spread was again demonstrated later . Frequent readmissions and transfers of patients appear to play an important part in this matter . None of the 51 colonized patients developed a serious VRE infection. Ned Tijdschr Geneeskd, 2000 Dec 30, 144(53), 2568 - 72 {Vancomycin-resistant Enterococcus faecium outbreak in a nephrology ward}; van der Steen LF et al.; In April 2000, an outbreak of vancomycin-resistant Enterococcus faecium (VRE) was discovered in an internal medicine/nephrology and dialysis ward of the Eemland Hospital, Amersfoort, the Netherlands . Although enterococci are considered relatively non-virulent, VRE are resistant to almost all commercially available antibiotics . Surveillance cultures were obtained from all patients at the ward, all patients visiting the dialysis ward and the environment of patients . VRE were determined and clustering of strains was analysed using molecular genotyping . In all, 12 patients were colonized with the outbreak strain . Transmission of VRE usually occurs via the hands of health care workers . The ward was closed for new admissions, patients were divided in cohorts of colonized and non-colonized patients, and rooms were disinfected after patient discharge . Infection control measures (such as handwashing and use of gloves and gowns) were enforced and prescriptions of vancomycin and cephalosporins were reduced . With these measures the outbreak could be controlled . Epidemiological analysis demonstrated that earlier admission and previous use of ciprofloxacin, amoxicillin and amoxicillin-clavulanic acid were risk factors for colonization . A nearby hospital was a possible source of this outbreak. Antimicrob Agents Chemother, 2001 Mar, 45(3), 986 - 9 Molecular analysis of Tn1546-like elements in vancomycin-resistant enterococci isolated from patients in Europe shows geographic transposon type clustering; Schouten MA et al.; Resistance mechanism relatedness was studied in 18 clinical, European vanA vancomycin-resistant enterococci . Molecular analysis revealed 10 Tn1546-like elements, suggesting two evolutionary lineages . Lineage I dominated the European mainland, and lineage II dominated the United Kingdom and Israel . Geographic clustering reflected different types of meat consumption between countries, since each lineage is associated with colonization of different animals. Antimicrob Agents Chemother, 2001 Mar, 45(3), 901 - 4 Enterocin P causes potassium ion efflux from Enterococcus faecium T136 cells; Herranz C et al.; Enterocin P is a bacteriocin produced by Enterococcus faecium P13 . We studied the mechanism of its bactericidal action using enterocin-P-sensitive E . faecium T136 cells . The bacteriocin is incapable of dissipating the transmembrane pH gradient . On the other hand, depending on the buffer used, enterocin P dissipates the transmembrane potential . Enterocin P efficiently elicits efflux of potassium ions, but not of intracellularly accumulated anions like phosphate and glutamate . Taken together, these data demonstrate that enterocin P forms specific, potassium ion-conducting pores in the cytoplasmic membrane of target cells. Clin Infect Dis, 2001 Feb 15, 32(4), 587 - 94 Epub 2001 Feb 07. Attributable mortality rate and duration of hospital stay associated with enterococcal bacteremia; Caballero-Granado FJ et al.; The mortality rate of patients with cases of enterococcal bacteremia is high, although it has often been related to the patients' underlying conditions rather than to the infection itself . To analyze the attributable prognosis of enterococcal bacteremia (assessed by its attributable mortality rate and duration of hospital stay), a prospective, matched case-control study was done . All adults with an episode of enterococcal bacteremia without endocarditis were included . A control patient was randomly selected for every case patient and matched by sex, age and hospital ward . Univariate and multivariate analyses were performed . A total of 122 pairs were included, and incidence of enterococcal bacteremia was 2.3 episodes/1000 discharges . Crude 30-day mortality rates for case patients and control patients were 23% and 17%, respectively (P=.29); thus, the estimated attributable mortality rate was 6% (95% confidence interval, -4% to 16%) . The mean duration of hospital stay of case patients and control patients were 38 and 17 days, respectively (P<.001); thus, the estimated attributable duration of hospital stay was 21 days (95% CI, 7-32 days) . Enterococcal bacteremia without endocarditis does not increase risk of death by itself but extends the duration of hospital stay of patients who develop it. Am J Infect Control, 2001 Feb, 29(1), 53 - 7 Evaluation of a successful vancomycin-resistant Enterococcus prevention intervention in a community of health care facilities; Sohn AH et al.; BACKGROUND: In April 1997, vancomycin-resistant enterococci (VRE) emerged in several health care facilities in the Siouxland region and a VRE Task Force was formed . From 1997 through 1999, an evaluation of VRE prevalence at 30 facilities was performed . METHODS: In 1999, we conducted a survey and focus groups of health care workers to address initial reactions to VRE, feasibility of the Task Force recommendations, and lessons learned . RESULTS: Personnel at 29 (97%) facilities surveyed completed the questionnaire, and 15 health care workers from 11 facilities participated in 5 focus groups . The outcomes of expanded education and improved awareness of VRE for patients and health care workers were ranked the No . 1 priority overall and by long-term care facility personnel . Respondents agreed that Task Force recommendation adherence had significantly improved infection control (83%) and that the Task Force was an appropriate mechanism to coordinate infection control efforts (90%) . Focus groups commented that it was most difficult to educate family members about VRE; they expressed concern about variation between VRE policies, especially between acute care and long-term care facilities, and about the quality of life of isolated patients . CONCLUSIONS: Our data illustrate that this intervention has been far-reaching and include the development of a health care infrastructure that may be used as a model to address additional health care issues (eg, emerging pathogens or biological threats). Chest, 2001 Feb, 119(2 Suppl), 426S - 30S Antibiotic utilization: is there an effect on antimicrobial resistance? Patterson JE. The antimicrobial resistance problem in hospitals continues to worsen . In particular, extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-KP) and vancomycin-resistant enterococci (VRE) are significant causes of morbidity and mortality among critically ill patients . Treating infections caused by these pathogens presents therapeutic dilemmas . The association between broad-spectrum beta-lactam overutilization and selection for ESBL-KP has been appreciated for some time; several institutions have reported a decrease in the prevalence of ESBL-KP with a shift in antibiotic utilization from third-generation cephalosporins to other broad-spectrum drugs . Currently, optimal treatment of ESBL-KP includes the carbapenems, but widespread use of these drugs is expensive and may be associated with further selection of antibiotic resistance and/or superinfection with other inherently resistant pathogens . VRE are especially difficult organisms to treat because of their inherent and acquired resistance to most currently available antibiotics . The prevalence of VRE has also been documented to decrease upon a shift in antibiotic use from third-generation cephalosporins to broad-spectrum antibiotics of other classes . Thus, antibiotic utilization measures appear to contribute to the control of the emergence of multidrug-resistant pathogens such as ESBL-KP and VRE. Chest, 2001 Feb, 119(2 Suppl), 405S - 411S Implementation of strategies to control antimicrobial resistance; Murthy R; Antimicrobial resistance has emerged as a major public health issue in recent years . A steady increase in resistance continues despite the introduction of new antibiotics, and resistant bacteria have been associated with increased patient morbidity and mortality as well as with increased costs . Addressing the problem of antimicrobial resistance requires both infection control and regulation of antibiotic use; addressing either alone is insufficient . Mounting evidence shows that control of the use of broad-spectrum antibiotics (especially vancomycin and third-generation cephalosporins) and implementation of infection control measures can result in decreased incidence of antibiotic-resistant bacteria such as vancomycin-resistant enterococci and extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella . Recent reports from professional organizations and a consensus of experts have outlined strategies for the control of resistance in hospitals, with specific measures identified for antibiotic control and infection control . These reports have emphasized the importance of a multidisciplinary approach in tackling this problem in hospitals and have suggested that a quality-improvement model be used to address antimicrobial resistance . A close collaboration among the disciplines of infectious diseases, microbiology, hospital epidemiology, pharmacy, and nursing, with particular emphasis in ICUs, and with strong support from hospital leadership, can result in an effective program that can be readily incorporated into the quality-improvement goals of any health-care organization. Biochem J, 2001 Feb 15, 354(Pt 1), 115 - 22 Bioactivity of {6R}-5-formyltetrahydrofolate, an unusual isomer, in humans and Enterococcus hirae, and cytochrome c oxidation of 10-formytetrahydrofolate to 10-formyldihydrofolate; Baggott JE et al.; The bio-inactive C-6 isomer, {6R}-5-formyl-tetrahydrofolate (5-HCO-H(4)F), is not found in Nature . An oral dose of 13.5 micromol of {6R}-5-HCO-H(4)F in humans results in the appearance of the naturally occurring {6S}-5-methyl-tetrahydrofolate and relatively large amounts of other bioactive folates in plasma . The removal of the asymmetry at C-6 could account for these results . Two oxidized cytochrome c {cyt c (Fe3+)} molecules oxidize one 10-formyl-tetrahydrofolate (10-HCO-H(4)F) with second-order kinetics and a rate constant of 1.3 x 10(4) M(-1) x s(-1) . The folate product of this oxidation reaction is 10-formyl-dihydrofolate (10-HCO-H(2)F), which has no C-6 asymmetric centre and is therefore bioactive . The folate-requiring bacterium, Enterococcus hirae, does not normally biosynthesize cytochromes but does so when given an exogenous source of haem (e.g . haemin) . E . hirae grown in haemin-supplemented media for 3 days utilizes both {6R}- and {6S}-5-HCO-H(4)F in contrast to that grown in control medium, which utilizes only the {6S} isomer . Since known chemical reactions form 10-HCO-H(4)F from 5-HCO-H(4)F, the unusually large rate constant for the oxidation of 10-HCO-H(4)F by cyt c (Fe3+) may account for the unexpected bioactivity of {6R}-5-HCO-H(4)F in humans and in E . hirae grown in haemin-containing media . We used an unnatural C-6 folate isomer as a tool to reveal the possible in vivo oxidation of 10-HCO-H(4)F to 10-HCO-H(2)F; however, nothing precludes this oxidation from occurring in vivo with the natural C-6 isomer. Kidney Int, 2001 Feb, 59(2), 718 - 24 Outpatient vancomycin use and vancomycin-resistant enterococcal colonization in maintenance dialysis patients; Atta MG et al.; BACKGROUND: Although outpatient vancomycin is widely used as empiric therapy for dialysis-associated infections, its relationship with vancomycin-resistant enterococcal (VRE) colonization is not established . METHODS: During a two-year prospective cohort study, rectal swabs obtained from patients at the start and finish of the study period and during interim hospitalizations were cultured for VRE . RESULTS: Ten of 124 patients initially grew VRE . Twenty-four of the remaining patients had no follow-up cultures because of patient death (62%), transfer to another dialysis facility (17%), patient's refusal (7%), and transplantation (4%), and were thus excluded . The remaining patients (N = 90) had a median age of 54.3 years and were 92% African American and 50% male . Fifty-eight percent were treated by hemodialysis . They received 403 g of intravenous vancomycin over 157.2 patient-years of follow-up, 73% as outpatients . Sixteen of 90 patients (17.8%) became colonized with VRE, an incidence rate of one case per 9.8 patient-years of follow-up . None of the 29 patients who did not receive vancomycin developed VRE compared with 26% of those treated with vancomycin (P = 0.001) . The odds ratio (95% CI) for the association of outpatient vancomycin (g per year) with VRE colonization was 1.23 (1.05, 1.44, P = 0.008) . The association remained significant following adjustment in separate logistic regression analyses for relevant demographic, clinical, antimicrobial (inpatient vancomycin, oral or intravenous cephalosprins, aminoglycosides, quinalones, or antianaerobics), and hospitalization exposures . The unadjusted relative risk of death in patients growing VRE was significantly higher than in those not colonized with VRE (P = 0.005) . CONCLUSIONS: VRE colonization is a relatively common and under recognized problem among chronic dialysis patients . It is strongly and independently associated with the outpatient use of vancomycin, which should be avoided whenever possible. Clin Microbiol Infect, 2000 Nov, 6(11), 585 - 92 National guidelines for the judicious use of glycopeptides in Belgium; Gordts B et al.; OBJECTIVE: The 'HICPAC guidelines', published in the USA in 1995 stressed the crucial role of restrictive usage of glycopeptides in the strategy to limit the emergence and spread of resistant enterococci . Because controversy still remains in Belgium on the necessity and feasability of restricting glycopeptide usage, the infectious diseases advisory board (IDAB) developed a consensus statement on the judicious use of glycopeptides in Belgium . METHODS: The literature on the indications for glycopeptide treatment was reviewed, categorized and discussed by a working party of the IDAB.Consequently, the IDAB reached consensus on the warranted indications for glycopeptide use in Belgium . RESULTS: The opinion of the IDAB-members is reported in a consensus statement specifying the indications for treatment and for prophylaxis with glycopeptide antimicrobials, as well as the situations where glycopeptides should not be used, taking into account the specific epidemiology of bacterial resistance, the availability of antibiotics and the common prescribing practices in Belgium . CONCLUSIONS: The IDAB concludes that restrictive usage of glycopeptides must also be a priority in Belgium . Guidelines on the judicious use of these antibiotics adapted to the national situations must contribute to this objective. Biochem Biophys Res Commun, 2001 Jan 26, 280(3), 713 - 9 Purification and functional analysis of the copper ATPase CopA of Enterococcus hirae; Wunderli-Ye H et al.; The Enterococcus hirae ATPase CopA is a member of the recently discovered heavy metal ATPases and shares 43% sequence identity with the human Menkes and Wilson copper ATPases . To study CopA biochemically, it was overexpressed in E . coli with an N-terminal histidine tag and purified to homogeneity by nickel affinity chromatography . The purified CopA catalyzed ATP hydrolysis with a V(max) of 0.15 micromol/min/mg and a K(m) for ATP of 0.2 mM and had an optimum pH of 6.25 . The activity was 3- to 4-fold stimulated by reconstitution into proteoliposomes . The enzyme formed an acylphosphate intermediate . Its kinetics of formation and the effects of inhibitors and metal ions upon it support a function of CopA in copper transport . Purification and functional reconstitution of CopA provides the basis to study copper transport in vitro . Antimicrob Agents Chemother, 2001 Feb, 45(2), 621 - 3 Linezolid therapy of vancomycin-resistant Enterococcus faecium experimental endocarditis; Patel R et al.; We compared the activities of linezolid (25 mg/kg of body weight, administered intraperitoneally every 8 h) and of vancomycin (25 mg/kg of body weight, administered intraperitoneally every 8 h) in a rat model of vanA vancomycin-resistant Enterococcus faecium experimental endocarditis . Results were expressed as median log(10) CFU per gram of vegetation after 3 days of treatment . The median log(10) CFU per gram of vegetation was 10.1 among 7 untreated control animals, 10.2 among 9 vancomycin-treated animals, and 7.9 among 10 linezolid-treated animals . Linezolid treatment was more active (P < 0.05) than vancomycin treatment or no treatment. J Clin Microbiol, 2001 Feb, 39(2), 820 - 2 Infection of central nervous system by motile Enterococcus: first case report; Kurup A et al.; A 66-year-old man with four indwelling ventriculoperitoneal shunts for multiloculated hydrocephalus from a complicated case of meningitis a year before developed shunt infection based on a syndrome of fever, drowsiness, and cerebrospinal fluid neutrophil pleocytosis in the background of repeated surgical manipulation to relieve successive shunt blockages . The cerebrospinal fluid culture, which yielded a motile Enterococcus species, was believed to originate from the gut . This isolate was lost in storage and could not be characterized further . The patient improved with vancomycin and high-dose ampicillin therapy . He relapsed a month later with Enterococcus gallinarum shunt infection, which responded to high-dose ampicillin and gentamicin therapy . This is probably the first case report of motile Enterococcus infection of the central nervous system. J Clin Microbiol, 2001 Feb, 39(2), 811 - 5 Vancomycin-resistant Enterococcus faecium strain carrying the vanB2 gene variant in a Polish hospital; Kawalec M et al.; About 2.5 years after the first isolation of the VanA phenotype of vancomycin-resistant Enterococcus faecium (VREM) in Poland, the first VREM strains with the VanB phenotype have emerged independently in two different Warsaw hospitals . In one of these the VREM strain was selected during the long-term antimicrobial treatment of a patient with a wide variety of infection risk factors who died after 3 months of hospitalization . The strain was found to contain the transferable vanB2 gene cluster variant of the polymorphic type that was identified earlier in vancomycin-resistant enterococci from several different countries . In the course of infection the strain underwent genetic diversification due to DNA recombination. Med Clin North Am, 2000 Nov, 84(6), 1471 - 95 Antienterococcal antibiotics; Lefort A et al.; The treatment of severe enterococcal infections based on the currently available antibacterial agents is difficult . The help of the microbiology laboratory for determining MICs, MBCs, and most effective synergistic combinations is crucial . There is a need for good prospective multicenter clinical trials to improve the prognosis of such infections by defining therapeutic strategies better . Such a requirement is highly suitable for the treatment of infections caused by enterococci exhibiting acquired resistance mechanisms to the available agents . The current clinical development of new compounds looks promising in these persistently life-threatening infections mostly occurring in deficient hosts. Tunis Med, 2000 Nov, 78(11), 667 - 70 {Infectious endocarditis caused by a glycopeptide-resistant enterococus}; Jouaihia W et al.; Enterococci are an important cause of infective endocarditis . Their resistance to most of the antibiotics involve real therapeutic problems . We report the first clinical isolate of glycopeptide resistant enterococcus from blood culture of patient with a prosthetic valve endocarditis . The strain is an E . faecium with a high level of resistance to vancomycin and teicoplanin (MIC > 256 mg/l), a low level of resistance to gentamycin (MIC = 6 mg/l) and susceptible to ampicillin (MIC = 1.5 mg/l) . Therapeutic failure was observed leading to a surgical treatment . Therapy of such infection caused by multiresistant Enterococcus must be based on the study of bactericidal activity of antibiotic associations . In order to control the spread of this emerging resistance, the implementation of control measures is necessary. J Antimicrob Chemother, 2001 Jan, 47(1), 105 - 8 Glycopeptide-resistant Enterococcus faecium infections in paediatric liver transplant recipients: safety and clinical efficacy of quinupristin/dalfopristin; Verma A et al.; We describe our experience of quinupristin/dalfopristin for glycopeptide-resistant Enterococcus faecium (GREF) infections in 19 paediatric liver transplant recipients . The median patient age was 2 years and all were receiving immunosuppressive regimens . Quinupristin/dalfopristin was well tolerated and complete resolution of infection was seen in 74% of patients . Side-effects included reversible elevation of serum alkaline phosphatase, skin rash, itching, diarrhoea and vomiting, but therapy was not withdrawn from any patient . Quinupristin/dalfopristin appears safe and efficacious in critically ill immunocompromised children with renal or hepatic impairment. Eur J Clin Microbiol Infect Dis, 2000 Nov, 19(11), 816 - 22 Prevalence of vancomycin-resistant enterococci in Europe; Schouten MA et al.; The aim of the present study was to determine the prevalence of vancomycin-resistant enterococci (VRE) in Europe . Overall, 49 laboratories in 27 countries collected 4,208 clinical isolates of enterococci . Species identification, susceptibility testing, and van gene determination by polymerase chain reaction were performed in a central laboratory . Overall, 18 vanA and 5 vanB isolates of VRE were found . The prevalence of vanA VRE was highest in the UK (2.7%), while the prevalence of vanB VRE was highest in Slovenia (2%) . Most vanA and vanB VRE were identified as Enterococcus faecium . Most VRE isolates originated from the patient's urogenital tract, skin, or digestive tract . VRE were equally distributed among clinical departments, with no clear preponderance in any single patient group . A total of 71 isolates containing the vanC gene were identified . The prevalence of vanC VRE was highest in Latvia and Turkey, where rates were 14.3 and 11.7%, respectively . Two-thirds of these isolates were identified as Enterococcus gallinarum and one-third as Enterococcus casseliflavus; the majority of these isolates were cultured from feces . Almost all isolates were obtained from hospitalized patients, mostly children . The highest prevalence of high-level gentamicin-resistant enterococci was seen in Turkey and Greece . In general, the distribution of this resistance type seemed unrelated to the occurrence of VRE . The prevalence of vanA/ vanB VRE in Europe is still low; the majority of the VRE isolates exhibit the vanC genotype and colonize the gastrointestinal tract of hospitalized children. Liver Transpl, 2001 Jan, 7(1), 27 - 31 Natural history of vancomycin-resistant enterococcal colonization in liver and kidney transplant recipients; Patel R et al.; At Mayo Medical Center (Rochester, MN), surveillance rectal (and other-site) cultures have been routinely collected from liver transplant recipients as part of a selective bowel decontamination program . Beginning in 1995, vancomycin-resistant enterococcus (VRE) colonization and infection were identified in Mayo Clinic liver and kidney transplant patients through our surveillance cultures . The purpose of this study is to describe the natural history of VRE colonization in this patient population . Fifty-two patients with VRE colonization (predominantly with a single vanB clone) were identified from September 1995 through December 1997 . Five hundred ninety cultures were reviewed for this study (mean, 11.3 cultures/patient) . The median time from initial VRE colonization to the last surveillance culture obtained was 306 days (range, 1 to 1,393 days) . VRE infection was documented in 6 patients (11.3%) . Eighteen patients (35%) met the criteria for clearance of VRE colonization, defined as VRE-negative rectal culture results on at least 3 consecutive occasions greater than 1 week apart . However, VRE was detected on subsequent surveillance cultures from 2 of these patients (11% relapse rate) . Of the remaining 34 patients, 16 remained colonized with VRE and 18 did not meet the definition for clearance of VRE colonization because of incomplete follow-up . This study documents that VRE colonization usually persists for months to years in liver and kidney transplant patients. Infect Control Hosp Epidemiol, 2000 Dec, 21(12), 789 - 91 Choice of antibiotic and risk of colonization with vancomycin-resistant Enterococcus among patients admitted for treatment of community-acquired pneumonia; Manzella J et al.; A time-series prospective study of patients admitted to the hospital for treatment of community-acquired pneumonia was undertaken to determine vancomycin-resistant enterococcal perianal colonization rates among patients who received ceftriaxone with or without erythromycin versus those who received levofloxacin . A colonization rate of 16% (8/51) was found in the ceftriaxone-erythromycin group versus 0% (0/52) in the levofloxacin group . Int J Antimicrob Agents, 2000 Nov, 16 Suppl 1, S19 - 24 Selective pressure by antibiotic use in livestock; Witte W; Selective pressure exerted by the use of antibiotics as growth promoters in food animals appears to have created large reservoirs of transferable antibiotic resistance in these ecosystems . This first became evident for oxytetracycline and later for the streptothricin antibiotic nurseothricin, for which a transfer of relevant resistance determinants (sat genes) to bacterial pathogens of humans was demonstrated . With the emergence of glycopeptide resistance in Enterococcus faecium outside hospitals, a large reservoir of transferable resistance (vanA gene cluster) was identified in animal husbandry due to the use of avoparcin as feed additive . The spread of resistance, which reaches the human enterococcal flora via meat products, is probably due to the dissemination of the vanA gene cluster integrated into different conjugative plasmids among a variety of different strains . Streptogramin resistance associated with the resistance genes vatA and vatG has been found in E . faecium of animal and of clinical origin . Because virginiamycin has been used as growth promoter in animals but streptogramins have been used infrequently in human medicine, this again suggests an animal origin of resistance . Since the use of avoparcin ended, a decline in the rates of glycopeptide-resistant E . faecium (GREF) from animals and humans in the community has been recorded . This supports the ban of antibacterial growth promoters that might interfere with human chemotherapy that has been introduced in European Union countries. Int J Antimicrob Agents, 2000 Nov, 16 Suppl 1, S11 - 7 Acquired and intrinsic glycopeptide resistance in enterococci; Gholizadeh Y et al.; Enterococci are Gram-positive cocci responsible for severe human infections, such as endocarditis, meningitis, and septicemia and constitute an increasingly frequent cause of nosocomial infections . Enterococci are resistant to nearly all classes of drugs including, since 1986, glycopeptides . Vancomycin and teicoplanin act by blocking cell wall formation and resistance is due to synthesis of modified late peptidoglycan precursors . Glycopeptide resistance can be intrinsic or acquired and strains may be resistant to vancomycin and teicoplanin, or to vancomycin only . Five types of glycopeptide resistance and their biochemical mechanisms have been described in enterococci . Clinical isolates that are dependent on vancomycin for growth have been isolated . Data suggest a dual origin for resistance: glycopeptide-producing organisms or enterococcal species intrinsically resistant to these drugs. J Clin Microbiol, 2001 Jan, 39(1), 351 - 3 Accuracy of the VITEK 2 system to detect glycopeptide resistance in enterococci; van Den Braak N et al.; We evaluated the accuracy of the VITEK 2 fully automated system to detect and identify glycopeptide-resistant enterococci (GRE) compared to a reference agar dilution method . The sensitivity of vancomycin susceptibility testing with VITEK 2 for the detection of vanA, vanB, and vanC1 strains was 100% . The sensitivity of vancomycin susceptibility testing of vanC2 strains was 77% . The sensitivity of teicoplanin susceptibility testing of vanA strains was 90% . Of 80 vanC enterococci, 78 (98%) were correctly identified by VITEK 2 as Enterococcus gallinarum/Enterococcus casseliflavus . Since the identification and susceptibility data are produced within 3 and 8 h, respectively, VITEK 2 appears a fast and reliable method for detection of GRE in microbiology laboratories. N Engl J Med, 2000 Dec 28, 343(26), 1925 - 32 Effect of antibiotic therapy on the density of vancomycin-resistant enterococci in the stool of colonized patients; Donskey CJ et al.; BACKGROUND: Colonization and infection with vancomycin-resistant enterococci have been associated with exposure to antibiotics that are active against anaerobes . In mice that have intestinal colonization with vancomycin-resistant enterococci, these agents promote high-density colonization, whereas antibiotics with minimal antianaerobic activity do not . METHODS: We conducted a seven-month prospective study of 51 patients who were colonized with vancomycin-resistant enterococci, as evidenced by the presence of the bacteria in stool . We examined the density of vancomycin-resistant enterococci in stool during and after therapy with antibiotic regimens and compared the effect on this density of antianaerobic agents and agents with minimal antianaerobic activity . In a subgroup of 10 patients, cultures of environmental specimens (e.g., from bedding and clothing) were obtained . RESULTS: During treatment with 40 of 42 antianaerobic-antibiotic regimens (95 percent), high-density colonization with vancomycin-resistant enterococci was maintained (mean {+/-SD} number of organisms, 7.8+/-1.5 log per gram of stool) . The density of colonization decreased after these regimens were discontinued . Among patients who had not received antianaerobic antibiotics for at least one week, 10 of 13 patients who began such regimens had an increase in the number of organisms of more than 1.0 log per gram (mean increase, 2.2 log per gram), whereas among 10 patients who began regimens of antibiotics with minimal antianaerobic activity, there was a mean decrease in the number of enterococci of 0.6 log per gram (P=0.006 for the difference between groups) . When the density of vancomycin-resistant enterococci in stool was at least 4 log per gram, 10 of 12 sets of cultures of environmental specimens had at least one positive sample, as compared with 1 of 9 sets from patients with a mean number of organisms in stool of less than 4 log per gram (P=0.002) . CONCLUSIONS: For patients with vancomycin-resistant enterococci in stool, treatment with antianaerobic antibiotics promotes high-density colonization . Limiting the use of such agents in these patients may help decrease the spread of vancomycin-resistant enterococci. Rinsho Byori, 2000 Nov, 48(11), 1036 - 43 {Vancomycin-resistant enterococci (VRE)}; Fujita N; Vancomycin-resistant enterococci is a worldwide threat not only in hospitals, but also in communities . Community-acquired infections play an important role in spreading VRE because the use of avoparcin, an antimicrobial growth promoter in food animals, is strongly suggested to cause the emergence of VRE . In particular, chickens imported into Japan have been reported to be highly contaminated with VRE, and this may be a key issue in the prevalence of VRE . Nosocomial VRE infections have become a serious problem in immuno-compromised patients throughout the world, and many VREs have been isolated in Japan in the last few years; however, fortunately, nosocomial outbreaks are still rare . VRE can survive for weeks in hospital environments, which makes infection control difficult and complicated, and strains of VRE resistant to almost all antimicrobial agents are a real threat . In outbreaks of VRE, prudent antimicrobial use and prompt effective infection control are important. Antimicrob Agents Chemother, 2001 Jan, 45(1), 243 - 51 In vitro activity of trovafloxacin against Bacteroides fragilis in mixed culture with either Escherichia coli or a vancomycin- resistant strain of Enterococcus faecium determined by an anaerobic time-kill technique; Stearne LE et al.; To determine the efficacy of trovafloxacin as a possible treatment for intra-abdominal abscesses, we have developed an anaerobic time-kill technique using different inocula to study the in vitro killing of Bacteroides fragilis in pure culture or in mixed culture with either Escherichia coli or a vancomycin-resistant strain of Enterococcus faecium (VREF) . With inocula of 5 x 10(5) CFU/ml and trovafloxacin concentrations of </=2 microg/ml, a maximum observed effect (E(max)) of >/=6.1 (log(10) CFU/ml) was attained with all pure and mixed cultures within 24 h . With inocula of 10(8) CFU/ml, a similar E(max) and a similar concentration to produce 50% of E(max) (EC(50)) for B . fragilis were found in both pure cultures and mixed cultures with E . coli . However, to produce a similar killing of B . fragilis in the mixed cultures with VREF, a 14-fold increase in the concentration of trovafloxacin was required . A vancomycin-susceptible strain of E . faecium and a trovafloxacin-resistant strain of E . coli were also found to confer a similar "protective" effect on B . fragilis against the activity of trovafloxacin . Using inocula of 10(9) CFU/ml, the activity of trovafloxacin was retained for E . coli and B . fragilis and was negligible against VREF . We conclude that this is a useful technique to study the anaerobic killing of mixed cultures in vitro and may be of value in predicting the killing of mixed infections in vivo . The importance of using mixed cultures and not pure cultures is clearly shown by the difference in the killing of B . fragilis in the mixed cultures tested . Trovafloxacin will probably be ineffective in the treatment of infections involving large numbers of enterococci . However, due to its ability to retain activity against large cultures of B . fragilis and E . coli, trovafloxacin could be beneficial in the treatment of intra-abdominal abscesses. J Microbiol Methods, 2001 Jan, 43(3), 233 - 9 Development of the Specific and Random Amplification (SARA)-PCR for both species identification of enterococci and detection of the vanA gene; Knijff E et al.; A rapid and reliable polymerase chain reaction (Specific and Random Amplification (SARA)-PCR) has been developed to identify enterococcal species and to detect the vanA gene in one single reaction . This technique was based on the use of the primer set previously designed to amplify a part of the vanA gene (Dutka-Malen et al., J . Clin . Microbiol., 33 (1995) 24-27) . In the chosen low stringency conditions complex patterns were obtained, with a sharp band of approximately 700 bp in cases where the vanA gene was present . Discrimination at the species and strain level was achieved by applying the SARA-PCR assay to a collection of 55 enterococcal isolates and type strains . Simultaneously the vanA gene was detected in all strains showing high resistance to vancomycin. Clin Infect Dis, 2001 Jan, 32(1), 23 - 9 Epub 2000 Dec 08. Vancomycin-resistant enterococci among chronic hemodialysis patients: a prospective study of acquisition; D'Agata EM et al.; To determine the prevalence and rate of acquisition of vancomycin-resistant enterococci (VRE) among patients undergoing chronic (i.e., long-term) hemodialysis who were admitted to a tertiary care center, serial rectal cultures for VRE were performed at hospital admission and every 5 days until hospital discharge . A total of 7 (6%) of the 119 patients were colonized with VRE at admission . Six (19%) of the 32 patients who remained in the hospital > or =4 days acquired VRE . A nonambulatory status was significantly associated with colonization at admission (OR, 9.7; 95% CI, 1.8-53; P=.01), and vancomycin exposure was significantly associated with VRE acquisition (relative risk, 1.8; 95% CI, 1.1-2.9; P=.02) . All patients acquired VRE from epidemiologically linked dialysis patients colonized with similar VRE genotypes . Hospital acquisition of VRE contributes substantially to the increasing prevalence of VRE in the chronic hemodialysis patient population. Int J Hyg Environ Health, 2000 Oct, 203(2), 147 - 52 Nosocomial outbreak of vancomycin-resistant Enterococcus faecium at a German university pediatric hospital; Elsner HA et al.; Nosocomial Infections caused by vancomycin-resistant enterococci (VRE) are an emerging threat to critically ill patients . At the University Hospital Eppendorf, VRE were isolated from 38 patients between August 1993 and April 1997, of whom 32 were hospitalized at the Department of Pediatrics . Pulsed-field gel electrophoresis revealed that 26 Enterococcus faecium isolates from patients of the Department of Pediatrics were identical or closely related, and that isolates from three additional patients of the same department were possibly related . All of these isolates were of vanA genotype . They were resistant to glycopeptides, ampicillin, ciprofloxacin, clindamycin, and erythromycin . Most isolates displayed high-level resistance to gentamicin, but all remained susceptible to quinupristin/dalfopristin . Implementation of stringent hand disinfection and environmental disinfection policies, as well as measures for patient isolation contained this first outbreak of VRE at a German Children's hospital, which emphasizes the importance of hygienic measures for the control of nosocomial spread of these organisms. Braz J Infect Dis, 1998 Jun, 2(3), 160 - 163 Vancomycin-Resistant Enterococcus faecium: First Case in Brazil; Dalla Costa LM et al.; We report a fatal case of septicemia due to a vancomycin-resistant Enterococcus faecium in a 9 year old girl with aplastic anemia . The isolate was also resistant to ampicillin, teicoplanin, gentamicin (high level), and streptomycin (high level) . We believe that this is the first case of vancomycin-resistant Enterococcus (VRE) reported from a clinical specimen in Brazil. Microbiology, 2000 Dec, 146 Pt 12, 3129 - 40 Antibacterial activity of synthetic analogues based on the disaccharide structure of moenomycin, an inhibitor of bacterial transglycosylase; Baizman ER et al.; Moenomycin is a natural product glycolipid that inhibits the growth of a broad spectrum of Gram-positive bacteria . In Escherichia coli, moenomycin inhibits peptidoglycan synthesis at the transglycosylation stage, causes accumulation of cell-wall intermediates, and leads to lysis and cell death . However, unlike Esc . coli, where 5-6 log units of killing are observed, 0-2 log units of killing occurred when Gram-positive bacteria were treated with similar multiples of the MIC . In addition, bulk peptidoglycan synthesis in intact Gram-positive cells was resistant to the effects of moenomycin . In contrast, synthetic disaccharides based on the moenomycin disaccharide core structure were identified that were bactericidal to Gram-positive bacteria, inhibited cell-wall synthesis in intact cells, and were active on both sensitive and vancomycin-resistant enterococci . These disaccharide analogues do not inhibit the formation of N:-acetylglucosamine-ss-1, 4-MurNAc-pentapeptide-pyrophosphoryl-undecaprenol (lipid II), but do inhibit the polymerization of lipid II into peptidoglycan in Esc . coli . In addition, cell growth was required for bactericidal activity . The data indicate that synthetic disaccharide analogues of moenomycin inhibit cell-wall synthesis at the transglycosylation stage, and that their activity on Gram-positive bacteria differs from moenomycin due to differential targeting of the transglycosylation process . Inhibition of the transglycosylation process represents a promising approach to the design of new antibacterial agents active on drug-resistant bacteria. Curr Infect Dis Rep, 1999 Oct, 1(4), 319 - 327 An Update on the Emergence of Glycopeptide Resistance in Enterococci; Gardam MA et al.; Glycopeptide resistance may be either constitutive or transferable (on plasmids or as a transposon), and four phenotypes (van A, B, C, D) have been described to date . Recent data suggest solid media screening protocols appear to be insensitive at detecting low levels of carriage, and up to 40% of colonized patients may be falsely glycopeptide-resistant enterococci (GRE) negative . Managing GRE-colonized or -infected patients using contact precautions appears to be useful in controlling clonal outbreaks, but may be of limited utility once GRE is endemic . Alternate strategies to manage GRE-colonized patients with prolonged carriage and in outpatient or home health settings include using risk-based transmission assessment to limit the logistic and psychosocial difficulties associated with the use of continuous contact precautions . The therapeutic options for treating GRE infection remain limited . Attempts to decolonize GRE-colonized patients with bacitracin appear to be of limited utility. Curr Infect Dis Rep, 1999 Jun, 1(2), 148 - 152 Vancomycin-Resistant Enterococcus: Infectious Endocarditis Treatment; Rybak MJ et al.; Vancomycin-resistant Enterococcus species represent serious gram-positive pathogens for which there is currently no recommended therapy . There are a number of new antibiotics with activity against these pathogens in development . Although there is a great deal of experience with some of these agents for skin and soft tissue infections, bacteremia, pneumonia, and intra-abdominal infections, there is currently little information available for the treatment of endocarditis . Animal and limited human data thus far suggest that new agents such as quinuprisitin-dalfopristin, LY333328 (a new glycopeptide antibiotic), and daptomycin (a lipopeptide antibiotic) may prove useful for this indication . Additional information, and especially combination treatment, are warranted to improve success and limit the emergence of resistance to these new antibiotics. Rev Esp Cardiol, 2000 Nov, 53(11), 1437 - 42 {Clinical features and prognosis of infective endocarditis in the elderly}; Castillo Dominguez JC et al.; INTRODUCTION AND OBJECTIVES: In recent decades the mean age of patients with infective endocarditis has progressively increased . The objective of the present study was to describe the clinical features and prognoses of infective endocarditis in the elderly . METHODS: A prospective study was performed of 125 non drug abuser patients over the age of 14 years and admitted from 1987 until 1997 in a single institution . Twenty-one patients were older than 65 years . RESULTS: No significant differences were observed among the age groups with respect to delay in diagnosis, clinical signs, site of the infection and the rate of negative blood cultures . Prosthetic valve endocarditis was more frequent in elderly than in younger adults (41 and 33%, respectively) . S . viridans and enterococcus were more frequent (47 compared with 29% in younger adults, p < 0.05) . Elderly patients underwent surgery less frequently (46 versus 56%) and most surgery was performed on an emergency basis . The in hospital mortality was higher in the elderly (50 versus 15%), p < 0.05 . CONCLUSIONS: Prosthetic valve endocarditis and severe complications during the active phase are more frequent in the elderly and this is related to a worse prognosis in the short and intermediate term . A higher rate of elective surgery during the active phase could improve the prognosis of infective endocarditis in the elderly. Antimicrob Agents Chemother, 2000 Dec, 44(12), 3444 - 6 Characterization of a divergent vanD-type resistance element from the first glycopeptide-resistant strain of Enterococcus faecium isolated in Brazil; Dalla Costa LM et al.; Enterococcus faecium 10/96A from Brazil was resistant to vancomycin (MIC, 256 microg/ml) but gave no amplification products with primers specific for known van genotypes . A 2,368-bp fragment of a van cluster contained one open reading frame encoding a peptide with 83% amino acid identity to VanH(D), and a second encoding a D-alanine-D-lactate ligase with 83 to 85% identity to VanD . The divergent glycopeptide resistance phenotype was designated VanD4. J Bacteriol, 2000 Dec, 182(23), 6806 - 14 Biochemical and genetic evidence that Enterococcus faecium L50 produces enterocins L50A and L50B, the sec-dependent enterocin P, and a novel bacteriocin secreted without an N-terminal extension termed enterocin Q; Cintas LM et al.; Enterococcus faecium L50 grown at 16 to 32 degrees C produces enterocin L50 (EntL50), consisting of EntL50A and EntL50B, two unmodified non-pediocin-like peptides synthesized without an N-terminal leader sequence or signal peptide . However, the bacteriocin activity found in the cell-free culture supernatants following growth at higher temperatures (37 to 47 degrees C) is not due to EntL50 . A purification procedure including cation-exchange, hydrophobic interaction, and reverse-phase liquid chromatography has shown that the antimicrobial activity is due to two different bacteriocins . Amino acid sequences obtained by Edman degradation and DNA sequencing analyses revealed that one is identical to the sec-dependent pediocin-like enterocin P produced by E . faecium P13 (L . M . Cintas, P . Casaus, L . S . Havarstein, P . E . Hernandez, and I . F . Nes, Appl . Environ . Microbiol . 63:4321-4330, 1997) and the other is a novel unmodified non-pediocin-like bacteriocin termed enterocin Q (EntQ), with a molecular mass of 3,980 . DNA sequencing analysis of a 963-bp region of E . faecium L50 containing the enterocin P structural gene (entP) and the putative immunity protein gene (entiP) reveals a genetic organization identical to that previously found in E . faecium P13 . DNA sequencing analysis of a 1,448-bp region identified two consecutive but diverging open reading frames (ORFs) of which one, termed entQ, encodes a 34-amino-acid protein whose deduced amino acid sequence was identical to that obtained for EntQ by amino acid sequencing, showing that EntQ, similarly to EntL50A and EntL50B, is synthesized without an N-terminal leader sequence or signal peptide . The second ORF, termed orf2, was located immediately upstream of and in opposite orientation to entQ and encodes a putative immunity protein composed of 221 amino acids . Bacteriocin production by E . faecium L50 showed that EntP and EntQ are produced in the temperature range from 16 to 47 degrees C and maximally detected at 47 and 37 to 47 degrees C, respectively, while EntL50A and EntL50B are maximally synthesized at 16 to 25 degrees C and are not detected at 37 degrees C or above. Haematologica, 2000 Nov, 85(11), 1158 - 64 Vancomycin-resistant Enterococcus faecium infection in three children given allogeneic hematopoietic stem cell transplantation: clinical and microbiologic features; Carretto E et al.; BACKGROUND AND OBJECTIVES: The emergence of vancomycin-resistant enterococci (VRE) as nosocomial pathogens is a major problem in the US; in Europe, VRE nosocomial infections are uncommon and only rarely have been reported in Pediatric or Neonatal Units . The aim of this study is to report on the clinical and microbiological features of VRE infections in 3 children given hematopoietic stem cell transplantation (HSCT) . PATIENTS AND METHODS: Five episodes of vancomycin-resistant Enterococcus faecium (VREF) infection were diagnosed in 3 children given an allogeneic HSCT . Molecular methods, such as random amplification of polymorphic DNA (RAPD) fingerprinting and automated ribotyping, were used in order to define the circulation of strains . RESULTS: All the isolates were resistant to all commercially available agents and showed the VanA genotypic profile . All children were successfully treated with the combination of quinupristin/dalfopristin (QD) plus teicoplanin (TEC), although treatment was not sufficient to eradicate the micro-organism promptly from the gastrointestinal tract . All our children are still alive . After the first isolation of VRE, a surveillance protocol was started and we documented that the rate of colonization in children and their mothers was less than 1.5% . The RAPD method demonstrated the possible nosocomial transmission of one strain . INTERPRETATION AND CONCLUSIONS: Our experience demonstrates that VRE infection is a life-threatening complication in children given HSCT . Prompt diagnosis of this infection and its treatment with the combination of QD and TEC can successfully manage this severe infection in profoundly immunocompromised patients. Cardiovasc Pathol, 2000 Sep-Oct, 9(5), 293 - 6 Active infective endocarditis involving all four cardiac valves; Steiner I et al.; A case is presented of a 70-year-old man treated for 3 months for necrotizing pancreatitis with multiorgan failure . The autopsy revealed enterococcal endocarditis affecting all eleven valvular cusps of the four heart valves. J Antimicrob Chemother, 2000 Nov, 46(5), 823 - 6 Impact of a new quinolone, DU-6859a, and two oral carbapenems, CS-834 and L-084, on the rat and mouse caecal microflora; Liu CX et al.; We determined the influence of a new quinolone, DU-6859a, and two oral carbapenems, CS-834 and L-084, on the rat and mouse caecal microflora . The caecum-skin fistula-implanted rats and conventional mice were given oral antimicrobials at doses of 30 mg/kg bid for 5 days . DU-6859a generated a marked decrease in the numbers of caecal flora except for enterococci . CS-834 and L-084 had little impact on the rat caecal flora . CS-834 caused a great decrease in the numbers of mouse caecal flora but L-084 did not . In vitro studies suggest that the difference is due to the extension of inactivation of antimicrobials by caecum contents. J Antimicrob Chemother, 2000 Nov, 46(5), 713 - 6 Influence of different medium components on the in vitro activity of the growth-promoting antibiotic flavomycin against enterococci; Butaye P et al.; The growth-promoting antibiotic flavomycin (also called bambermycin, flavophospholipol and moenomycin) has a complex spectrum of activity against enterococci, with some species being naturally resistant and others susceptible . In this study, proteins added to Mueller-Hinton II medium had a strong deleterious effect on the activity of flavomycin, glucose had no effect and starch decreased the activity of flavomycin . The fatty substances Tween 80 and tributyrin increased the activity of flavomycin for several enterococcal species . Slight differences in the composition of the susceptibility test medium affected the MIC results obtained, indicating that strict standardization of the test medium is necessary. J Clin Microbiol, 2000 Nov, 38(11), 4242 - 5 Improved pulsed-field gel electrophoresis for typing vancomycin-resistant enterococci; Turabelidze D et al.; A rapid protocol for subtyping vancomycin-resistant enterococci by pulsed-field gel electrophoresis is reported . The procedure is simple and potentially cost-effective and allows reproducible subtyping of the strains in approximately 1 day. J Clin Microbiol, 2000 Nov, 38(11), 4201 - 7 Application of tRNA intergenic spacer PCR for identification of Enterococcus species; Baele M et al.; tRNA intergenic spacer PCR (tDNA-PCR) was evaluated for its usefulness in the differentiation of enterococcal species of human and animal origin . This technique was carried out for 124 strains belonging to 17 enterococcal species and generated DNA fragments, which were separated by capillary electrophoresis . tDNA-PCR enabled us to discriminate for all species tested . Enterococcus faecium showed minor but reproducible differences with Enterococcus durans, while Enterococcus hirae was easily distinguishable . Enterococcus avium, Enterococcus malodoratus, and Enterococcus raffinosus generated highly similar though distinctive patterns. J Clin Microbiol, 2000 Nov, 38(11), 4058 - 65 Evaluation of fluorescence-based amplified fragment length polymorphism analysis for molecular typing in hospital epidemiology: comparison with pulsed-field gel electrophoresis for typing strains of vancomycin-resistant Enterococcus faecium; Antonishyn NA et al.; Fluorescence-based amplified fragment length polymorphism (fbAFLP) is a novel assay based on the fluorescent analysis of an amplified subset of restriction fragments . The fbAFLP assay involves the selective PCR amplification of restriction fragments from a total digest of genomic DNA . The ligation of adapters with primer-specific sites coupled with primers containing selective nucleotides allowed the full potential of PCR to be realized while maintaining the advantages of restriction endonuclease analysis . Fluorescence-based fragment analysis with polyacrylamide gel electrophoresis provides the accurate band sizing required for homology assessment . The large number of phylogenetically informative characters obtained by fbAFLP is well suited for cluster analysis and database development . The method demonstrated excellent reproducibility and ease of performance and interpretation . We typed 30 epidemiologically well-characterized isolates of vancomycin-resistant enterococci from an outbreak in a university hospital by fbAFLP . Clustering of fbAFLP data matched epidemiological, microbiological, and pulsed-field gel electrophoresis data . This study demonstrates the unprecedented utility of fbAFLP for epidemiological investigation . Future developments in standardization and automation will set fbAFLP as the "gold standard" for molecular typing in epidemiology. Braz J Med Biol Res, 2000 Nov, 33(11), 1269 - 74 Typing of Enterococcus faecium by polymerase chain reaction and pulsed field gel electrophoresis; Bedendo J et al.; Polymerase chain reaction (PCR) with JB1 or REP consensus oligonucleotides and pulsed field gel electrophoresis (PFGE) were used to study genomic DNA extracted from 31 strains of enterococci . Eleven ATCC strains, representative of 11 species of Enterococcus, were initially tested by JB1-PCR, revealing that Enterococcus malodoratus and Enterococcus hirae presented identical banding patterns . Eight Enterococcus faecium isolates from Stanford University and 12 from Sao Paulo Hospital were studied by JB1-PCR, REP-PCR (1/2)R and PFGE . Among the isolates from Stanford University, 5 genotypes were defined by JB1-PCR, 7 by REP-PCR (1/2)R and 4 by PFGE . Among the isolates from Sao Paulo Hospital, 9 genotypes were identified by JB1-PCR, 6 by REP-PCR and 5 by PFGE . The three methods identified identical genotypes, but there was not complete agreement among them. Clin Infect Dis, 2000 Oct, 31(4), 1058 - 65 Epub 2000 Oct 25. Insights into the epidemiology and control of infection with vancomycin-resistant enterococci; Hayden MK; Despite control efforts, the incidence of nosocomial infections due to vancomycin-resistant enterococci (VRE) continues to increase in the United States . VRE are thought to spread primarily by cross-contamination . Recent molecular epidemiologic studies have refined our understanding of this phenomenon . If VRE are not controlled soon after introduction into a hospital, sporadic cases may evolve into a monoclonal outbreak, which may then evolve to polyclonal endemicity . An intervention that is effective in containing VRE in one setting may be ineffective in another . Control of VRE where they are endemic is particularly challenging . Although eradication of endemic VRE may not be possible, aggressive, multifaceted programs have been successful in diminishing the problem . A mathematical model of transmission of VRE and the effect of infection control measures in settings where they are endemic has been reported . The use of such a model may allow more precise determination of the impact of control strategies in the future. Protein Expr Purif, 2000 Nov, 20(2), 300 - 7 Analysis of three overexpression systems for VanX, the Zinc(II) dipeptidase required for high-level vancomycin resistance in bacteria; Brandt JJ et al.; The gene from Enterococcus faecilis encoding the dipeptidase VanX was subcloned into overexpression vectors pET-5b, pET-27b, and IMPACT-T7, and VanX was overexpressed in BL21(DE3) pLysS Escherichia coli . The pET-5b-vanx overexpression plasmid produces VanX at approximately 12 mg/L under optimum conditions . VanX produced from this overexpression system exists primarily as a dimer in solution, binds ca . 1 Zn(II) ion per monomer, and exhibits K(m) and k(cat) values of 500 +/- 40 microM and 0.074 +/- 0.001 s(-1), respectively, when l-alanine-p-nitroanilide is used as substrate . The IMPACT-T7-vanx overexpression plasmid produces a VanX-fusion protein with a chitin-binding domain that allows for purification of the fusion construct with a chitin column . Cleavage of the fusion protein is completed by an on-column chemical cleavage, resulting in approximately 10 mg/L of purified VanX . VanX produced from this system is identical to that produced from the pET-5b system, except the CD spectrum of the IMPACT-T7-produced VanX suggests a small change in secondary structure . This change in secondary structure does not affect any of the kinetic or metal-binding properties of the enzyme . The pET-27b-vanx overexpression plasmid produces and secretes VanX into the growth medium; this system allows for 20 mg of VanX to be isolated per liter of growth medium . The pET-27b-produced VanX is identical to that produced from pET-5b . J Infect, 2000 Jul, 41(1), 95 - 7 Treatment of a vancomycin-resistant Enterococcus faecium ventricular drain infection with quinupristin/dalfopristin and review of the literature; Tan TY et al.; Central nervous system infections involving vancomycin-resistant Enterococcus faecium (VREF) are infrequently described and pose significant therapeutic difficulties, because these organisms are intrinsically resistant to many antibiotics . We describe the use of intrathecal quinupristin/dalfopristin to treat a VREF-associated infection in a neuro--surgical patient. Antimicrob Agents Chemother, 2000 Nov, 44(11), 3189 - 92 Impact of flavophospholipol and vancomycin on conjugational transfer of vancomycin resistance plasmids; Riedl S et al.; The influence of vancomycin and flavophospholipol (FPL) on the transfer rate of conjugative plasmids harboring the vancomycin resistance operon vanA was determined in several clinical and animal isolates of Enterococcus faecium . FPL significantly inhibited the frequency of transfer of conjugative VanA plasmids up to 70-fold . Vancomycin had no significant effect on the transfer rate of VanA plasmids. Int J Syst Evol Microbiol, 2000 Sep, 50 Pt 5, 1755 - 60 Atopobacter phocae gen . nov., sp . nov., a novel bacterium isolated from common seals; Lawson PA et al.; Two strains of a Gram-positive, catalase-negative, facultatively anaerobic, rod-shaped bacterium isolated from common seals were characterized using phenotypic and molecular taxonomic methods . The two strains closely resembled each other based on their biochemical characteristics, and PAGE analysis of whole-cell protein patterns confirmed their close phenotypic affinity . 16S rRNA gene sequencing showed that the two strains were genetically highly related (99.8% sequence similarity) and that they constitute a new line of descent within the lactic acid group of bacteria . The nearest phylogenetic neighbours of the unknown bacterium were Granulicatella spp., with related taxa such as enterococci, carnobacteria, Desemzia incerta, Lactosphaera pasteurii, Melissococcus plutonius, tetragenococci and vagococci more distantly related . Based on phylogenetic and phenotypic evidence it is proposed that the unknown bacterium from seals be classified in a new genus as Atopobacter phocae gen . nov., sp . nov . The type strain of Atopobacter phocae is CCUG 42358T (= CIP 106392T). J Bacteriol, 2000 Nov, 182(21), 6228 - 32 Vancomycin resistance is associated with serine-containing peptidoglycan in Enterococcus gallinarum; Grohs P et al.; In Enterococcus gallinarum SC1, a low-level vancomycin-resistant strain, only monomeric muropentapeptides with a C-terminal D-alanine were detected after growth without vancomycin . In contrast, in SC1 induced by vancomycin, as well as in AIB39, a constitutive vancomycin-resistant strain, monomeric and dimeric muropentapeptides with a C-terminal D-serine were detected. Shock, 2000 Sep, 14(3), 343 - 6 Selective digestive tract decontamination and vancomycin-resistant enterococcus isolation in the surgical intensive care unit; Dahms R et al.; Vancomycin-resistant Enterococcus (VRE) has emerged as a significant nosocomial pathogen in the surgical intensive care unit (SICU) . We wished to test the hypothesis that the use of selective digestive tract decontamination (SDD) in the SICU affects the frequency of VRE isolation . A retrospective review of hospital records and the SICU database was performed using patients admitted to the SICU service for three or more days from January 1, 1996 to December 31, 1999 at our large tertiary-care teaching hospital . During this time use of SDD in selected patient populations decreased due to physician preference . Information gathered included length of SICU stay, presence of VRE infection or colonization, and use and duration of SDD protocol, vancomycin, and ceftazidime . There were 110 newly diagnosed VRE cases in the SICU during this time period . During the same time period 54 patients received SDD . Eight patients who received SDD had positive VRE cultures and seven had the initial positive culture after receiving SDD . Overall, 9.1% of eligible SICU patients received SDD, 18.5% of patients in the SICU for over 3 days had VRE, 7.3% of VRE patients received SDD, and 13.0% of the SICU patients who received SDD subsequently developed VRE . SDD use was not associated with VRE in univariate analysis . Logistic regression analysis showed higher odds ratios for SDD use in combination with vancomycin than for vancomycin use alone (OR=4.3 vs . 10.9) . Odds ratios were over three times higher for SDD plus vancomycin plus ceftazidime use when compared to vancomycin plus ceftazidime use alone (OR=70.5 vs . 19.8) . We conclude that administration of SDD alone did not correlate with increased VRE isolation, but that SDD use in conjunction with vancomycin and ceftazidime was associated with VRE isolation. Shock, 2000 Sep, 14(3), 259 - 64 Reduction of vancomycin-resistant enterococcal infections by limitation of broad-spectrum cephalosporin use in a trauma and burn intensive care unit; May AK et al.; Both vancomycin and third-generation cephalosporin use are believed to contribute to a rise in vancomycin-resistant enterococci (VRE) infections . In 1998, the largest number of VRE infections in our hospital occurred in the trauma/burn intensive care unit (TBICU), accounting for nearly 20% of hospital infections . In an attempt to control the VRE infection rate, antibiotic protocols for prophylaxis, empiric, and definitive therapy were initiated during the final quarter of 1998 to minimize cephalosporin use by the introduction of piperacillin/tazobactam . Therefore, we undertook a study of the VRE infection rate for the TBICU in relation to vancomycin, piperacillin/tazobactam, piperacillin, third-generation cephalosporin, and total cephalosporin use before and after efforts to limit cephalosporins . These data were compared to those in the medical and surgical intensive care units . During 1998, seven VRE infections occurred in the TBICU . Following initiation of antibiotic protocols, one case of VRE infection occurred in the subsequent month and no cases in the 17 months since . The decrease in the VRE infection rate corresponded with a significant increase in the use of piperacillin/tazobactam and a reduction in third-generation and total cephalosporin use . In contrast, cephalosporin use in the medical and surgical intensive care units remains significantly higher than in the TBICU, and neither unit has had a reduction in their VRE infection rates. Clin Microbiol Rev, 2000 Oct, 13(4), 513 - 22 Relationships between enterococcal virulence and antimicrobial resistance; Mundy LM et al.; Enterococci have become a vexing problem in clinical medicine because of their ability to infect patients who are typically receiving antibiotic therapy for unrelated underlying illness . Moreover, the infections have become extremely difficult to manage because of the accumulation of antibiotic resistances among enterococci . The ability of enterococci to cause disease is an intrinsic property of the organism or possibly subpopulations within enterococcal species . The probability of an infection's becoming established, however, is almost certainly in part a function of the enterococcal burden . By altering endogenous bacterial flora, antibiotic therapy promotes increased colonization by antibiotic-resistant organisms . Therefore, antibiotic resistance and intrinsic virulence both contribute to disease, but in separate and complementary ways . We review the virulence of enterococci, as distinct from the acquisition of antimicrobial resistance genes, and identify current gaps in our understanding of enterococcal virulence and the basis for disease. Int J Food Microbiol, 2000 Sep 25, 60(2-3), 185 - 94 Occurrence of the vancomycin-resistant genes vanA, vanB, vanCl, vanC2 and vanC3 in Enterococcus strains isolated from poultry and pork; Lemcke R et al.; It is suspected that the use of avoparcin as a feeding antibiotic for the fat stock contributes to development of cross-resistance against vancomycin and teicoplanin . After isolating enterococci strains from poultry and pork meat by cultivation on citrate azide Tween carbonate agar (CATC) and screening the vancomycin resistance on Columbia colistin nalidixic acid agar (CNA, supplemented with 5% sheepblood and 5 mg vancomycin/l) the polymerase chain reaction (PCR) was used for the detection of the vancomycin resistance genes vanA ('high level'), vanB ('moderate high level'), vanC1, vanC2 and vanC3 ('low level') . Out of 1643 E.-isolates from 115 poultry and 50 pork samples, 420 isolates could be identified as vancomycin resistant, 202 isolates of which carry the vanA, one isolate both the vanA and the vanC1, 38 isolates the vanC1, 14 isolates the vanC2, nine isolates both the vanC1 and the vanC3 gene and 156 isolates carry no gene . The vanB gene was not found in these isolates . Comparing vanA-positive food isolates with those from different human sources by means of the pulsed field gel electrophoresis (PFGE) it could clearly be demonstrated that they do not show homological fingerprints according to the source of origin . It is therefore unlikely that there is a close genetic relationship between isolates from animal foodstuff and humans. Appl Environ Microbiol, 2000 Oct, 66(10), 4200 - 4 A strain of Enterococcus faecium (18C23) inhibits adhesion of enterotoxigenic Escherichia coli K88 to porcine small intestine mucus; Jin LZ et al.; Few studies, if any, have addressed the adhesion of enterococci to the intestinal mucosa and their interference with the adhesion of pathogens, although more than 60% of probiotic preparations in the market contain strains of enterococci . The objective of this study was to investigate if Enterococcus faecium 18C23 has the ability to inhibit the adhesion of Escherichia coli K88ac and K88MB to the small intestine mucus of piglets . Approximately 9% of E . faecium 18C23 organisms adhered to the small intestine mucus, and the adhesion was found to be specific . Living E . faecium 18C23 culture efficiently inhibited the adhesion of E . coli K88ac and K88MB to the piglet intestine mucus . Inhibition of the adhesion of E . coli K88ac to the small intestine mucus was found to be dose dependent . Inhibition of >90% was observed when 10(9) CFU or more of living E . faecium 18C23 culture per ml was added simultaneously with E . coli to immobilized mucus . The substances from both the 18C23 cells and the spent culture supernatant contributed to the inhibition of adhesion of E . coli K88 to the small intestine mucus receptors . The inhibiting effect was not solely a pH effect since considerable inhibitory action was demonstrated after neutralizing the mixture or spent culture supernatant to pH 7.0 . Part of the inhibition of adhesion of E . coli K88ac by E . faecium 18C23 or its supernatant might occur through steric hindrance. Pharmacotherapy, 2000 Sep, 20(9 Pt 2), 203S - 212S; discussion 224S-228S Control of glycopeptide-resistant enterococci in an oncology unit; Bradley SJ; Enterococci are responsible for 10-12% of nosocomial infections . Since 1987 the incidence of glycopeptide-resistant enterococci (GRE; termed vancomycin-resistant enterococci in the United States) has increased dramatically . The mechanism of GRE is well understood and involves mutation of a single terminal amino acid in a peptidoglycan precursor leading to reduced vancomycin affinity . Studies implicated antibiotic selection pressure as a major risk factor for GRE infection and colonization . In the hematology unit of a London hospital, GRE emerged in December 1993, with 38% of patients positive in a point prevalence study . Between December 1993 and June 1995, 13 patients acquired GRE bacteremia, five of whom died . Between 1995 and 1996 a prospective sequential study was undertaken to determine the effect of changing antibiotic treatment of febrile neutropenia (FN) . All patients admitted to the hematology unit were enrolled in the study . In phase 1, treatment continued with ceftazidime monotherapy . In phase 2, piperacillin-tazobactam replaced ceftazidime, and enhanced infection control measures were encouraged . In phase 3, therapy returned to ceftazidime . In phase 1, 57% of patients became colonized or infected with GRE . Phase 2, which was divided into two 4-month cohorts, showed a significant reduction in GRE acquisition, falling to 8% colonization and no clinical infections in the second 4 months . In phase 3, despite heightened infection control procedures, the acquisition rate rose to 36%. Infect Control Hosp Epidemiol, 2000 Sep, 21(9), 575 - 82 Outbreak of vancomycin-resistant enterococci in a burn unit; Falk PS et al.; OBJECTIVE: To investigate and control an outbreak of colonization and infection caused by vancomycin-resistant enterococci (VRE) in a burn intensive care unit (BICU) . DESIGN: Epidemiological investigation, including multiple point-prevalence culture surveys of patients and environment, cultures from hands of healthcare workers (HCWs), pulsed-field gel electrophoresis (PFGE) typing of patient and environmental isolates, case-control study, and institution and monitoring of control measures . SETTING: BICU in an 800-bed university medical center in Galveston, Texas . RESULTS: Between June 6, 1996, and July 14, 1997, 21 patients were colonized by VRE, and 4 of these patients developed bacteremia . Of 2,844 environmental cultures, 338 (11.9%) were positive, but all hand cultures from HCWs were negative . PFGE typing indicated that the outbreak was clonal, with VRE isolates from patients differing by < or =4 bands from the index case . Thirteen of 14 environmental isolates varied by < or =4 bands from the pattern of the index case . A case-control study analyzed by exact logistic regression identified diarrhea (odds ratio {OR}, 43.9; 95% confidence interval {CI95}, 5.5-infinity; P=.0001) and administration of an antacid (OR, 24.2; CI95, 2.9-infinity; P=.002) as independent risk factors for acquisition of VRE . During a 5-week period in October and November 1996, all patient and 317 environmental cultures were negative for VRE . The outbreak recurred from a contaminated electrocardiogram lead that had not been identified during the prior 5 weeks . VRE were finally eradicated from the BICU in July 1997, using barrier isolation and a very aggressive environmental decontamination program . CONCLUSIONS: A VRE outbreak in a BICU over 13 months was caused by a single clone . After apparent eradication of VRE from a BICU, recrudescence of the outbreak occurred, evidently from a small inapparent source of environmental contamination . Changes in gastrointestinal (GI) tract function (motility) and administration of medications, other than antibiotics, that have an effect on the GI tract may increase the risk of GI tract colonization by VRE in burn patients . Application of barrier isolation and an aggressive environmental decontamination program can eradicate VRE from a burn population. Antimicrob Agents Chemother, 2000 Oct, 44(10), 2876 - 9 Detection of the high-level aminoglycoside resistance gene aph(2")-Ib in Enterococcus faecium; Kao SJ et al.; A new high-level gentamicin resistance gene, designated aph(2")-Ib, was cloned from Enterococcus faecium SF11770 . The deduced amino acid sequence of the 897-bp open reading frame of aph(2")-Ib shares homology with the aminoglycoside-modifying enzymes AAC(6')-APH(2"), APH(2")-Ic, and APH(2")-Id . The observed phosphotransferase activity is designated APH(2")-Ib. Oncology (Huntingt), 2000 Aug, 14(8 Suppl 6), 31 - 4 Current treatments for infection in neutropenic patients with hematologic malignancy; Greene JN et al.; Neutropenic patients with cancer are a heterogeneous group of patients who carry a variable risk for infection . When such patients present with fever, appropriate empiric antibiotic therapy is initiated and continued until clinical improvement or clinical or microbiologic data direct a modification in treatment . As the duration of neutropenia increases, so does the need for antimicrobial modifications . Changes in therapy may include antimicrobials directed against gram-positive bacteria, resistant gram-negative bacteria, or fungi . Because of the high risk for colonization by vancomycin-resistant enterococci, vancomycin use is restricted as first-line empiric therapy unless the patient is at a high risk for serious gram-positive infection . Usually in the setting of neutropenia, gram-positive infections are of low virulence . Prophylactic antibiotic therapy may increase the selection of resistant strains and should be avoided . Antibiotic therapy should always be combined with prudent infection-control measures, such as aseptic practices, barrier isolation, handwashing, removal of infected catheters, and infection monitoring . In the immunocompromised patient with cancer and neutropenia, all infections should be treated, with the extent, duration, and site of treatment being directed by risk stratification and specific pathogen identification . Patients with neutropenia are at risk for severe morbidity and mortality related to infection. Clin Infect Dis, 2000 Aug, 31(2), 586 - 9 Epub 2000 Sep 07. Aminoglycoside resistance in enterococci; Chow JW; High-level aminoglycoside resistance in enterococci is mediated generally by aminoglycoside-modifying enzymes, which eliminate the synergistic bactericidal effect usually seen when a cell wall-active agent is combined with an aminoglycoside . Clinical microbiology laboratories currently screen for aminoglycoside resistance in enterococci by testing gentamicin and streptomycin susceptibility . If the recently detected aminoglycoside resistance genes, aph(2")-Ib, aph(2")-Ic, and aph(2")-Id, become more prevalent among clinical isolates, the approach for detecti