Enterococci

FEMS Microbiol Lett, 1999 Apr 1, 173(1), 265 - 71
In situ inversion of the conjugative transposon Tn916 in Enterococcus faecium DPC3675; O'Keeffe T et al.; Enterococcus faecium DPC3675 is a derivative of E . faecium DPC1146 which contains a single copy of the conjugative transposon Tn916 . Although the transposon is observed to be oriented in one direction in individual colonies, DNA extracted from cultures grown from these colonies contains the transposon in both orientations, as determined by PCR analysis and sequencing of the transposon/chromosome junctions . Therefore, Tn916 possesses a hitherto unreported ability to invert within a particular insertion site during growth in broth.

Chest, 1999 Apr, 115(4), 1085 - 91
The incidence of and clinical variables associated with vancomycin-resistant enterococcal colonization in mechanically ventilated patients; Bhorade SM et al.; STUDY OBJECTIVES: (1) To determine in our ICU the incidence of vancomycin-resistant enterococcus (VRE) colonization in mechanically ventilated patients without a history of VRE infection or colonization; and (2) to determine the risk factors and outcome variables associated with VRE colonization in these patients . DESIGN: A prospective cohort study conducted between January 1996 and March 1998 . SETTING: Medical and cardiac critical care units in a tertiary care urban university hospital . PATIENTS: Mechanically ventilated patients without evidence of pneumonia at the onset of ventilation . INTERVENTIONS: None . MEASUREMENTS AND RESULTS: Patients underwent rectal cultures by standard methods on day 1, day 3 or 4, day 6 or 7, and day 14 of intubation to detect VRE . Thirteen of 83 patients (16%) had rectal cultures positive for VRE (VRE+) at some point while being mechanically ventilated during their stay in the ICU . In comparison, approximately 15 of 2,100 medical ICU patients (0.7%) had clinical VRE infections as determined by the hospital's infection control program during a 2-year period . VRE+ patients had a higher incidence of immunosuppression than patients who had rectal cultures negative for VRE (VRE-) (9 of 13 {69%} vs 16 of 70 {23%}, respectively; p < 0.01) and neutropenia (4 of 13 {31%} vs 5 of 70 {7%}, respectively; p < 0.01) . Hospital length of stay (LOS) was longer in VRE+ patients than in VRE- patients (27+/-17 days vs 17+/-14 days, respectively; p = 0.05), whereas pre-ICU hospital LOS and ICU LOS were similar in both patient groups . Five of 67 patients (7%) were VRE+ on day 1 of intubation, suggesting colonization at a prior site of care . Three of 29 patients who had subsequent rectal cultures converted to VRE+ while in the ICU . This group had a higher incidence of immunosuppression and neutropenia, and received more vancomycin compared with the patients who remained VRE- (p < 0.01) . However, there was no significant difference in the use of other broad-spectrum antibiotics (such as antipseudomonal penicillins, third-generation cephalosporins, quinolones, and clindamycin), enteral tube feedings, or sucralfate between the two groups . In addition, a topical antibiotic paste (a gentamicin, nystatin, polymixin slurry) that was placed in the oropharynx to prevent bacterial overgrowth was not found to increase the incidence of VRE colonization in this patient population . CONCLUSIONS: The incidence of VRE colonization was surprisingly high: 16% in mechanically ventilated patients in a hospital in which VRE was not previously known to be endemic . Risk factors for the acquisition of VRE colonization included immunosuppression, neutropenia, and vancomycin use . Increased LOSs and hospital costs were seen in VRE+ patients compared to VRE- patients . Whether VRE colonization is a contributor to severe disease that leads to prolonged hospitalization and increased resource allocation or whether it is simply a marker of disease severity cannot be determined from this study . To the extent that specific antibiotic protocols are used to reduce antibiotic-resistant flora in the ICU, monitoring the incidence of VRE in the stool specimens of immunocompromised, mechanically ventilated patients can be a simple and useful tool to assess one effect of these strategies.

J Clin Microbiol, 1999 May, 37(5), 1638 - 41
Survey of antibiotic resistance among enterococci in North Rhine-Westphalia, Germany; Reinert RR et al.; A surveillance study on antibiotic resistance of enterococcal isolates (n = 730) was carried out in North Rhine-Westphalia, Germany, in 1997 . Resistance rates to ampicillin (7.4%), high-level gentamicin (15.0%), high-level streptomycin (27.9%), ciprofloxacin (37.9%), vancomycin (1.5%), and teicoplanin (1.5%) were determined . All vancomycin-resistant enterococci (VRE) carried the vanA gene . SmaI and ApaI macrorestriction patterns indicated an intra- and interhospital spread of VRE.

Br J Biomed Sci, 1998 Jun, 55(2), 149 - 56
The emergence of enterococci as a cause of nosocomial infection; Hunt CP; Enterococci have traditionally been regarded as low-grade pathogens but have emerged as an increasingly important cause of nosocomial infection . The rise in hospital-acquired enterococcal infection has been in part due to the increased use of broad-spectrum antibiotics and the rising number of severely ill patients . The intrinsic resistance of enterococci to many antimicrobial agents, and the acquisition of resistance to the few antibiotics available for treatment, has led to real therapeutic difficulties . The microbiological laboratory has an important role to play in the control of enterococcal infection through surveillance, and should be able to identify antibiotic-resistant strains likely to cause a problem . Infection control measures, such as source isolation of infected or colonised patients, should be considered . The possibility that vancomycin-resistant strains of enterococci are entering the community via the food chain indicates the need for greater control of the use of glycopeptide antibiotics in animal feed.

Am J Infect Control, 1999 Apr, 27(2), 84 - 91
Improving the appropriateness of vancomycin use by sequential interventions; Lipsky BA et al.; BACKGROUND: Vancomycin usage is directly associated with the incidence of vancomycin-resistant enterococci . Optimal methods to reduce inappropriate use have not been delineated . We determined the appropriateness of vancomycin prescribing at our hospital on the basis of national guidelines and assessed the effect of sequential administrative and educational interventions . METHODS: In this prospective 3-phase study conducted in a Veterans Affairs Medical Center, we monitored vancomycin prescribing at baseline and in 2 follow-up periods . Administrative interventions included discussions with service chiefs and revising routine perioperative antibiotic prophylaxis orders . Educational interventions included in-services about vancomycin-resistant enterococci and appropriate vancomycin prescribing . In each monitoring period, 50 consecutive new vancomycin orders that could be evaluated were classified for appropriateness and categorized by indication . RESULTS: At baseline, 70% of vancomycin use was inappropriate . Surgical services accounted for 84% of orders . Interventions targeted services with high or frequently inappropriate vancomycin use . After administrative interventions, inappropriate vancomycin use dropped to 40% of orders (P =.003) . Improvements were noted in targeted services . Educational interventions further decreased inappropriate vancomycin use, but the effect appeared transient . CONCLUSIONS: The simple, nonrestrictive administrative interventions used resulted in a statistically significant (30%) reduction in inappropriate vancomycin prescribing . However, educational interventions provided only transient benefit on institutional prescribing patterns.

J Microbiol Methods, 1999 Mar, 35(2), 95 - 100
Reverse transcription polymerase chain reaction method for the detection of glycopeptide resistance in enterococci; Privitera O et al.; In this work we have developed reverse transcription polymerase chain reaction (RT-PCR) methods for detecting specific mRNA from enterococci, particularly vanA and vanB genes, responsible for glycopeptide resistance in this genus . mRNA from the two genes was detected immediately after RNA extraction of a midlog phase culture, determined by growth rate analysis . Because of the short half-life associated with many bacterial RNA species (1.5-2 min), time is an important factor in obtaining RNA of good yield and high purity . Our results showed that: (i) the transcription of mRNA related to vanA ligase in enterococci showing Van A phenotype happens only after induction with both vancomycin and teicoplanin; (ii) the transcription of mRNA related to vanB ligase happens only in the presence of vancomycin and (iii) there was no transcription of mRNA in the two strains positive to vanA gene after PCR experiments . RT-PCR methodology can have numerous applications in microbiology for studying gene expression in isolated bacteria and also in nonculturable cells in environmental samples, for studies of mechanisms and/or as an indicator of viability in bacterial communities.

Syst Appl Microbiol, 1999 Feb, 22(1), 9 - 21
Determination of the nucleotide sequence of the 23S ribosomal RNA and flanking spacers of an Enterococcus faecium strain, reveals insertion-deletion events in the ribosomal spacer 1 of enterococci; Naimi A et al.; The usefulness of 16S-23S (ITS1) and 23S-5S (ITS2) ribosomal spacer nucleotide sequence determination, as a complementary approach to the biochemical tests traditionally used for enterococcal species identification, is shown by its application to the identification of a strain, E27, isolated from a natural bacteria mixture used for cheese production . Using combined approaches we showed, unambiguously, that strain E27 belongs to the Enterococcus faecium species . However, its ITS1 region has an interesting peculiarity . In our previous study of ITS1s from various enterococcal species (NAIMI et al., 1997, Microbiology 143, 823-834), the ITS1s of the two E . faecium strains studied, were found to contain an additional 115-nt long stem-loop structure as compared to the ITS1s of other enterococci, only one out of the 3 ITS1s of E . hirae ATCC 9790, was found to contain a similar 107-nt long stem-loop structure . The ITS1 of strain E27 is 100% identical to that of E . faecium ATCC 19434T, except that the 115-nt additional fragment is absent . This strongly suggests the existence of lateral DNA transfer or DNA recombination events at a hot spot position of the ITS1s from E . faecium and E . hirae . Small and large ITS1 nucleotide sequence determination for strain E27 generalized the notion of two kinds of ITSs in enterococci: one with a tRNA(Ala) gene, one without tRNA gene . To complete strain E27 characterization, its 23S rRNA sequence was established . This is the first complete 23S rRNA nucleotide sequence determined for an enterococcal species.

Appl Environ Microbiol, 1999 Apr, 65(4), 1777 - 80
Genomic relationships between Enterococcus faecium strains from different sources and with different antibiotic resistance profiles evaluated by restriction endonuclease analysis of total chromosomal DNA using EcoRI and PvuII; Quednau M et al.; Forty-seven Enterococcus faecium strains from different sources were evaluated by restriction endonuclease analysis (REA) of total chromosomal DNA . Strains from chicken, pork, and humans were clearly divided into separate clusters, whereas strains from different countries, strains with different antibiotic resistance profiles, or clinical and healthy-subject strains were not.

Infect Control Hosp Epidemiol, 1999 Mar, 20(3), 171 - 5
The prevalence of colonization with vancomycin-resistant Enterococcus at a Veterans' Affairs institution; Tokars JI et al.; OBJECTIVE: To study vancomycin-resistant Enterococcus (VRE) prevalence, risk factors, and clustering among hospital inpatients . DESIGN: Rectal-swab prevalence culture survey conducted from February 5 to March 22, 1996 . SETTING: The Veterans' Affairs Medical Center, Atlanta, Georgia . PATIENTS: Hospital (medical and surgical) inpatients . RESULTS: The overall VRE prevalence was 29% (42/147 patients) . The VRE prevalence was 52% (38/73 patients) among patients who had received at least one of six specific antimicrobials during the preceding 120 days, compared with only 5% (4/74) among those who had not received the antimicrobials (relative risk, 9.6; P<.001) . The longer the period (up to 120 days) during which antimicrobial use was studied, the more closely VRE status was predicted . Among 67 hospital patients in 28 multibed rooms, clustering of VRE among current roommates was not found . CONCLUSIONS: At this hospital with relatively high VRE prevalence, VRE colonization was related to antibiotic use but not to roommate VRE status . In hospitals with a similar VRE epidemiology, obtaining cultures from roommates of VRE-positive patients may not be as efficient a strategy for identifying VRE-colonized patients as obtaining screening cultures from patients who have received antimicrobials.

Yonsei Med J, 1998 Dec, 39(6), 562 - 8
Vancomycin-resistant enterococcal infections in Korea; Kim JM et al.; Enterococci recently became the second-to-third most commonly isolated organism from nosocomial infections . Enterococci are intrinsically more resistant to many antimicrobial agents and often show acquired resistance to many antimicrobial agents including high-level aminoglycosides . With the increased use of vancomycin, vancomycin-resistant enterococci (VRE) has become an important nosocomial pathogen . In Korea, the proportion of VRE among all enterococcal of VRE is no longer low in some settings and recent observations of a sudden increase of VRE isolation in several hospitals in Korea suggests that VRE infection may become a serious problem in the near future . The most important considerations are that vancomycin-resistant genes may spread to other highly virulent genera, such as MRSA, and that there are no approved and convincingly effective antibiotics for the treatment of VRE . Therefore, current efforts have concentrated on limiting the spread of these organisms within the hospital environment . Prudent use of antimicrobial agents and strict adherence to preventive measures such as aggressive communication, education, and infection control practices are essential to control the spread of this organism . However, hospital infection control protocols and the laboratory support they require are costly in terms of space and supplies, as well as in personnel resources . These factors add further pressure to already stretched hospital budgets . Nevertheless, policies or programs defining and managing VRE infection or colonization should be established and now is the time to enforce an overall management strategy against VRE.

Yonsei Med J, 1998 Dec, 39(6), 554 - 61
Antimicrobial resistance in enterococci; Pai CH et al.; Enterococci have emerged as a major nosocomial pathogen and as an ever-increasing problem in antimicrobial resistance . They are ubiquitous in the intestinal flora of humans and animals and inherently resistant to a wide array of antimicrobial agents, and, more alarmingly, they seem to have a potential facility for acquiring new resistance determinants, including beta-lactamase production, high-level resistance to aminoglycosides, and recently, glycopeptide resistance . Collectively, all of these properties make enterococci one of most difficult nosocomial pathogens to treat and control today . The purpose of this review was to examine the epidemiology, the mechanisms, and laboratory detection of resistance of enterococci to the two major groups of antibiotics: aminoglycosides and glycopeptides.

HNO, 1999 Jan, 47(1), 25 - 32
{Modification of bacterial growth by alloplastic bone substitutes}; Geyer G et al.; BACKGROUND: To determine the applicability of alloplastic materials as bone substitutes it is now standard procedure to test materials for possible toxic effects and to study their behavior in animal models and cell cultures . This is especially important with respect to middle ear implants that can be put at risk by recurrent infections and require additional testing in a bacterially contaminated environment . MATERIALS AND METHODS: In the present study ionomeric cement (V-O CEM), bioactive glass ceramic and hydroxyapatite were subjected to contamination with S . aureus, E . coli, Pr . mirabilis, Ps . aeruginosa and Enterococci using agar diffusion and microbial suspension tests and examined for their antibacterial activity . A special feature of V-O CEM that had to be considered was that it could be implanted in two physical states (as a viscous substance and a fully hardened material) . RESULTS: The agar diffusion test showed that an antibacterial effect of freshly mixed V-O CEM was demonstrable for up to 60 min . In the microbial suspension test growth of E . coli was found to be promoted after 48-h incubation by V-O CEM set for 1 h . S . aureus exhibited a depressed growth, while Pseudomonas cultures demonstrated cell death after 48 h . V-O CEM set for 24 h and 7 days, respectively, exerted a similar though less pronounced effect . Using the microbial suspension test, a comparison was also made of the antibacterial activities of 24-h V-O CEM, bioactive glass ceramic and hydroxyapatite against cultures of S . aureus, Pseudomonas and E . coli . The inhibitory effect of hydroxyapatite on the growth of S . aureus was found to persist beyond the 48-h incubation period . There was slight growth of E . coli in the presence of bioactive glass ceramic after 48 h, whereas hydroxyapatite produced inhibition of microbial growth . V-O CEM inhibited the growth of Pseudomonas, unlike bioactive glass ceramic and hydroxyapatite, which transiently promoted bacterial growth . DISCUSSION AND CONCLUSIONS: Our findings showed that V-O CEM, bioactive glass ceramic and hydroxyapatite exhibited material-dependent bacterial colonization and thus resembled polymeric bone substitutes (susceptible to invasion by S . epidermidis) and metals (sensitive to S . aureus) . In general, users of bone substitutes should conduct preclinical tests in order to obtain advance information on the properties of possible replacement material . Since there can be varying interactions between the materials studied and bacterial growth, material-specific effects on bacterial growth should be investigated . While it is recognized that in vitro studies are an inadequate simulation of the clinical situation, they still provide some insight into the likely behavior of a bone substitutes in human sites.

Pediatr Cardiol, 1999 May-Jun, 20(3), 227 - 8
Enterococcus avium endocarditis in an infant with tetralogy of Fallot; Swaminathan S et al.; We report a case of infective endocarditis secondary to Enterococcus avium in a 1-year-old infant with tetralogy of Fallot and a Blalock-Taussig shunt . To our knowledge, this is the first case of E . avium endocarditis to be reported.

Emerg Infect Dis, 1999 Jan-Feb, 5(1), 143 - 6
Proficiency of clinical laboratories in and near Monterrey, Mexico, to detect vancomycin-resistant enterococci; McDonald LC et al.; Early detection of vancomycin-resistant enterococci is important for preventing its spread among hospitalized patients . We surveyed the ability of eight hospital laboratories in and near Monterrey, Mexico, to detect vancomycin resistance in Enterococcus spp . and found that although laboratories can reliably detect high-level vancomycin resistance, many have difficulty detecting low-level resistance.

J Clin Microbiol, 1999 Apr, 37(4), 1084 - 91
DNA banding pattern polymorphism in vancomycin-resistant Enterococcus faecium and criteria for defining strains; Morrison D et al.; The degree of DNA banding pattern polymorphism exhibited by vancomycin-resistant Enterococcus faecium (VREM) strains isolated on a renal unit over an 11-month period was investigated . Thirty VREM strains from different patients were analyzed by pulsed-field gel electrophoresis (PFGE; with extended run and optimal pulse times), ribotyping, plasmid profile analysis, biotyping, pyrolysis mass spectrometry, and antibiogram analysis . PFGE resolved 17 banding patterns which formed four distinct clusters at the 82% similarity level . Intercluster band differences ranged from 14 to 31 bands . The strains in one cluster, which contained seven patterns that differed from each other by one to seven bands and from the common pattern by five bands, were confirmed to be a single strain by four of the five other typing methods . The strains in a second cluster with eight patterns, which differed from each other by 1 to 12 bands, contained two subclusters . This subdivision was supported by ribotyping and biotyping . However, it was unclear whether these subclusters represented distinct strains . In one strain, marked polymorphism (patterns that differed from each other by up to four bands) was observed in the ribotype pattern . This study demonstrates the high degree of DNA banding pattern polymorphism found for some strains of VREM and illustrates the complexity involved in defining such strains.

Chem Biol, 1999 Mar, 6(3), 177 - 87
Mutational analysis of active-site residues of the enterococcal D-ala-D-Ala dipeptidase VanX and comparison with Escherichia coli D-ala-D-Ala ligase and D-ala-D-Ala carboxypeptidase VanY; Lessard IA et al.; BACKGROUND: Vancomycin-resistant enterococci are pathogenic bacteria that attenuate antibiotic sensitivity by producing peptidoglycan precursors that terminate in D-Ala-D-lactate rather than D-Ala-D-Ala . A key enzyme in effecting antibiotic resistance is the metallodipeptidase VanX, which reduces the cellular pool of the D-Ala-D-Ala dipeptide . RESULTS: We constructed eleven mutants, using the recently determined VanX structure as a basis, to investigate residue function . Mutating Asp142 or Ser114 showed a large effect principally on KM, consistent with roles in recognition of the D-Ala-D-Ala termini . The drastic reduction or absence of activity in the Arg71 mutants correlates with a role in the stabilization of an anionic tetrahedral transition state . Three residues of the Escherichia coli D-Ala-D-Ala ligase (Ddl), Glu15, Ser 281 and Arg255, are similarly conserved and have equivalent functions with respect to VanX, consistent with a convergent evolution of active sites to bind D-Ala-D-Ala and lower energy barriers for formation of the tetrahedral intermediate and transition states . In the N-acyl-D-Ala-D-Ala carboxypeptidase VanY, all active-site residues are conserved (except for the two responsible for recognition of the dipeptide amino terminus) . CONCLUSIONS: The mutagenesis results support structure-based functional predictions and explain why the VanX dipeptidase and Ddl ligase show narrow specificity for the D,D-dipeptide substrate . The results reveal that VanX and Ddl, two enzymes that use the same substrate but proceed in opposite directions driven by distinct cofactors (zinc versus ATP), evolved similar architectural solutions to substrate recognition and catalysis acceleration . VanY sequence analysis predicts an active site and mechanism of reaction similar to VanX.

Biochemistry, 1999 Mar 9, 38(10), 3000 - 11
Equilibrium analyses of the active-site asymmetry in enterococcal NADH oxidase: role of the cysteine-sulfenic acid redox center; Mallett TC et al.; Recent studies {Mallett, T . C., and Claiborne, A . (1998) Biochemistry 37, 8790-8802} of the O2 reactivity of C42S NADH oxidase (O2 --> H2O2) revealed an asymmetric mechanism in which the two FADH2.NAD+ per reduced dimer display kinetic inequivalence . In this report we provide evidence indicating that the fully active, recombinant wild-type oxidase (O2 --> 2H2O) displays thermodynamic inequivalence between the two active sites per dimer . Using NADPH to generate the free reduced wild-type enzyme (EH2'/EH4), we have shown that NAD+ titrations lead to differential behavior as only one FADH2 per dimer binds NAD+ tightly to give the charge-transfer complex . The second FADH2, in contrast, transfers its electrons to the single Cys42-sulfenic acid (Cys42-SOH) redox center, which remains oxidized during the reductive titration . Titrations of the reduced NADH oxidase with oxidized 3-acetylpyridine and 3-aminopyridine adenine dinucleotides further support the conclusion that the two FADH2 per dimer in wild-type enzyme can be described as distinct "charge-transfer" and "electron-transfer" sites, with the latter site giving rise to either intramolecular (Cys42-SOH) or bimolecular (pyridine nucleotide) reduction . The reduced C42S mutant is not capable of intramolecular electron transfer on binding pyridine nucleotides, thus confirming that the Cys42-SOH center is in fact the source of the redox asymmetry observed with wild-type oxidase . These observations on the role of Cys42-SOH in the expression of thermodynamic inequivalence as observed in wild-type NADH oxidase complement the previously described kinetic inequivalence of the C42S mutant; taken together, these results provide the overlapping framework for an alternating sites cooperativity model of oxidase action.

FEBS Lett, 1999 Feb 19, 445(1), 27 - 30
The Enterococcus hirae copper chaperone CopZ delivers copper(I) to the CopY repressor; Cobine P et al.; Expression of the cop operon which effects copper homeostasis in Enterococcus hirae is controlled by the copper responsive repressor CopY . Purified Zn(II)CopY binds to a synthetic cop promoter fragment in vitro . Here we show that the 8 kDa protein CopZ acts as a copper chaperone by specifically delivering copper(I) to Zn(II)CopY and releasing CopY from the DNA . As shown by gel filtration and luminescence spectroscopy, two copper(I) are thereby quantitatively transferred from Cu(I)CopZ to Zn(II)CopY, with displacement of the zinc(II) and transfer of copper from a non-luminescent, exposed, binding site in CopZ to a luminescent, solvent shielded, binding site in CopY.

Infect Control Hosp Epidemiol, 1999 Feb, 20(2), 106 - 9
Control of vancomycin-resistant enterococci at a community hospital: efficacy of patient and staff cohorting; Jochimsen EM et al.; OBJECTIVE: To evaluate the efficacy of patient and staff cohorting to control vancomycin-resistant enterococci (VRE) at an Indianapolis community hospital . DESIGN: To interrupt transmission of VRE, a VRE point-prevalence survey of hospital inpatients was conducted, and VRE-infected or -colonized patients were cohorted on a single ward with dedicated nursing staff and patient-care equipment . To assess the impact of the intervention, staff compliance with contact isolation procedures was observed, and the VRE point-prevalence survey was repeated 2 months after the cohort ward was established . RESULTS: Following the establishment of the cohort ward, VRE prevalence among all hospitalized inpatients decreased from 8.1% to 4.7% (25 positive cultures among 310 patients compared to 13 positive cultures among 276 patients, P=.14); VRE prevalence among patients whose VRE status was unknown before cultures were obtained decreased from 5.9% to 0.8% (18 positive cultures among 303 patients compared to 2 positive cultures among 262 patients, P=.002); and observed staff-patient interactions compliant with published isolation recommendations increased (5 {22%} of 23 interactions compared to 36 {88%} of 41 interactions, P<.0001) . CONCLUSIONS: Our data suggest that, in hospitals with endemic VRE or continued VRE transmission despite implementation of contact isolation measures, establishing a VRE cohort ward may be a practical and effective method to improve compliance with infection control measures and thereby to control epidemic or endemic VRE transmission.

J Hosp Infect, 1999 Feb, 41(2), 137 - 43
Isolation and epidemiological study of vancomycin-resistant Enterococcus faecium from patients of a haematological unit in Poland; Samet A et al.; Enterococcus faecium has recently emerged as a serious nosocomial pathogen . Vancomycin resistant enterococci (VRE) have been isolated in Europe and the USA since 1988 . This is the first report on isolation of vancomycin resistant E . faecium (VREM) strains in Poland, from Haematological Unit patients in the Clinical Hospital in Gdansk . In total, 6412 samples were examined between December 1996 and October 1997 . Five hundred and five isolates of Enterococcus spp . were collected . One hundred and one were classified as Enterococcus faecium of which 49 were resistant to vancomycin (MIC > 256 mg/L) and teicoplanin (MIC > 256 mg/L), characteristic of the VanA phenotype . Twenty-nine patients were infected or colonized . A PCR-based specific diagnostic assay confirmed the phenotype . The multiplex PCR-restriction fragment length polymorphism patterns were consistent with VanA-type of vancomycin-resistant E . faecium for all isolates examined . These isolates were epidemiologically-related as shown by PCR-fingerprinting.

Antimicrob Agents Chemother, 1999 Mar, 43(3), 592 - 7
Synergy of an investigational glycopeptide, LY333328, with once-daily gentamicin against vancomycin-resistant Enterococcus faecium in a multiple-dose, in vitro pharmacodynamic model; Zelenitsky SA et al.; The pharmacodynamics of an investigational glycopeptide, LY333328 (LY), alone and in combination with gentamicin, against one vancomycin-susceptible and two vancomycin-resistant Enterococcus faecium strains were studied with a multiple-dose, in vitro pharmacodynamic model (PDM) . Dose-range data for the PDM studies were obtained from static time-kill curve studies . In PDM experiments conducted over 48 h, peak LY concentrations of 0.1x and 1x the MIC every 24 h and peak gentamicin concentrations of 18 micrograms/ml every 24 h (Gq24 h) and 6 micrograms/ml every 8 h (Gq8 h) were studied alone and in the four possible LY-gentamicin combinations . Compared to either antibiotic alone, LY-gentamicin combination regimens produced significantly higher apparent killing rates (KRs) calculated during the initial 2 h postdosing . The mean KRs for LY or gentamicin alone versus those for the LY-gentamicin combination regimens were 0.35 +/- 0.55 log10 CFU/ml/h (95% confidence interval {CI95%}, 0 to 0.70) and 1.46 +/- 0.71 log10 CFU/ml/h (CI95%, 1.01 to 1.91), respectively (P < 0.0001) . Bacterial killing at 48 h (BK48), which was calculated by subtracting the bacterial counts at 48 h from the initial inoculum, with a negative value indicating net growth, was also significantly greater . The mean BK48S were -0.69 +/- 0.44 log10 CFU/ml (CI95%, -0.41 to -0.97) and 3.72 +/- 2.28 log10 CFU/ml (CI95%, 2.28 to 5.17) for LY or gentamicin alone versus LY-gentamicin combination regimens, respectively (P < 0.0001) . None of the 12 regimens with LY or gentamicin alone but 75% (9 of 12) of the LY-gentamicin combination regimens were bactericidal . Eighty-three percent (10 of 12) of the LY-gentamicin combination regimens also demonstrated synergy . No significant differences between the pharmacodynamics of LY-gentamicin combination regimens containing Gq24 h versus those containing Gq8h were detected.

Antimicrob Agents Chemother, 1999 Mar, 43(3), 483 - 91
Molecular diversity and evolutionary relationships of Tn1546-like elements in enterococci from humans and animals; Willems RJ et al.; We report on a detailed study on the molecular diversity and evolutionary relationships of Tn1546-like elements in vancomycin-resistant enterococci (VRE) from humans and animals . Restriction fragment length polymorphism (RFLP) analysis of the VanA transposon of 97 VRE revealed seven different Tn1546 types . Subsequent sequencing of the complete VanA transposons of 13 VRE isolates representing the seven RFLP types followed by sequencing of the identified polymorphic regions in 84 other VanA transposons resulted in the identification of 22 different Tn1546 derivatives . Differences between the Tn1546 types included point mutations in orf1, vanS, vanA, vanX, and vanY . Moreover, insertions of an IS1216V-IS3-like element in orf1, of IS1251 in the vanS-vanH intergenic region, and of IS1216V in the vanX-vanY intergenic region were found . The presence of insertion sequence elements was often associated with deletions in Tn1546 . Identical Tn1546 types were found among isolates from humans and farm animals in The Netherlands, suggesting the sharing of a common vancomycin resistance gene pool . Application of the genetic analysis of Tn1546 to VRE isolates causing infections in Hospitals in Oxford, United Kingdom, and Chicago, Ill., suggested the possibility of the horizontal transmission of the vancomycin resistance transposon . The genetic diversity in Tn1546 combined with epidemiological data suggest that the DNA polymorphism among Tn1546 variants can successfully be exploited for the tracing of the routes of transmission of vancomycin resistance genes.

J Biochem (Tokyo), 1999 Feb, 125(2), 414 - 21
Properties of the V0V1 Na+-ATPase from Enterococcus hirae and its V0 moiety; Murata T et al.; We report here the large-scale purification of vacuolar (V0V1)-type Na+-ATPase from Enterococcus hirae achieved using column anion-exchange and gel filtration chromatographies; 32 mg of purified enzyme comprising nine subunits, A, B, C, D, E, F, G, I, and K, was obtained from 20 liter culture . This amount is 500-fold larger than that reported in the previous paper {Murata, T., Takase, K., Yamato, I., Igarashi, K., and Kakinuma, Y . (1997) J . Biol . Chem . 272, 24885-24890} . The purified enzyme shows a high specific activity of ATP hydrolysis (35.7 micromol Pi released/min/mg protein) . ATP-driven 22Na+ uptake by reconstituted V0V1-proteoliposomes exhibited an apparent Kt value for Na+ of 40 microM, which is near the Km value (20 microM) for Na+ of the ATP hydrolytic activity . Denatured gel electrophoresis revealed that six subunits, A, B, C, D, E, and F, are releasable as the V1 subunit from the V0V1 complex by incubation with ethylenediaminetetraacetic acid; subunit G was not identified . The remaining V0-liposomes containing I and K subunits catalyzed Na+ uptake in response to potassium diffusion potential (Deltapsi, inside negative); the Kt value for Na+ of this reaction was estimated to be about 2 mM . Inhibition by N,N'-dicyclohexylcarbodiimide (DCCD) of the Na+-ATPase activity and Deltapsi-driven Na+ uptake by the V0-liposomes was prevented by the presence of Na+, suggesting that the Na+ binding site overlaps with the DCCD-reactive site.

J Clin Microbiol, 1999 Mar, 37(3), 818 - 20
Variation in structure and location of VanA glycopeptide resistance elements among enterococci from a single patient; Tremlett CH et al.; Forty-six VanA glycopeptide-resistant enterococci (GRE) from a single patient were investigated for variation in structure and location of VanA resistance elements . Together with identification to species level and pulsed-field gel electrophoresis, these data divided the GRE into 10 groups and subgroups . Combining data in this manner appears helpful when investigating the epidemiology of GRE.

Am J Surg, 1998 Dec, 176(6A Suppl), 67S - 73S
Treatment of acute gynecologic infections with trovafloxacin . Trovafloxacin Surgical Group; Roy S et al.; BACKGROUND: Trovafloxacin, a broad-spectrum fourth-generation quinolone with gram-positive and gram-negative aerobic and anaerobic bacterial activity, is available in oral and intravenous formulations . The objective of this prospective, multicenter, double-blind, randomized study was to compare the efficacy of trovafloxacin with that of cefoxitin, an approved drug for treatment of acute gynecologic infections, together with amoxicillin/clavulanic acid as oral follow-on treatment . METHODS: Patients with a clinical diagnosis of acute pelvic infection received either intravenous alatrofloxacin with oral trovafloxacin follow-on (trovafloxacin) or a combined regimen of cefoxitin followed by amoxicillin/clavulanic acid for a maximum of 14 days . The primary endpoint was clinical response to therapy on follow-up at day 30 . RESULTS: Clinical success rates were comparable between the trovafloxacin (n = 107) and comparative (n = 119) groups at study end (90% vs . 86%, respectively; 95% confidence interval, -4.5, 12.5) . Among clinically evaluable patients, clinical success rates for infections involving Enterococcus species were higher with trovafloxacin than with the comparative regimen at the end of treatment (96% and 85%) and at study end (96% and 86%) . CONCLUSION: Intravenous alatrofloxacin followed by oral trovafloxacin for a maximum of 14 days of total therapy was efficacious in the treatment of acute pelvic infections.

Infect Control Hosp Epidemiol, 1999 Jan, 20(1), 60 - 3
Vancomycin use in a hospital with vancomycin restriction; Roghmann MC et al.; We evaluated vancomycin use in a hospital with endemic vancomycin-resistant enterococci and a vancomycin restriction program . Only 68% of vancomycin was prescribed appropriately . Inappropriate use was due primarily to empirical therapy . In the patients with a microbiological diagnosis following empirical therapy, 83% (25/30) had infections due to bacteria sensitive to an appropriate antibiotic other than vancomycin . However, only 60% (15/25) of these patients had their vancomycin orders changed.

Ann Surg, 1999 Jan, 229(1), 137 - 45
Reconstructive surgery for ischemic-type lesions at the bile duct bifurcation after liver transplantation; Schlitt HJ et al.; OBJECTIVE: To assess the feasibility, morbidity, mortality, and clinical success rate of surgical reconstruction of the biliary system in patients with ischemic-type biliary lesions in their liver graft . SUMMARY BACKGROUND DATA: After liver transplantation, strictures in the biliary tree with secondary sludge formation can occur in the absence of vascular problems . Jaundice, pruritus, and recurrent cholangitis are predominant clinical features leading to considerable morbidity . Interventional measures are the first-line treatment but are frequently only of transient success . Retransplantation is usually considered when interventional treatment is not effective . METHODS: Surgical exploration and reconstruction was performed in 17 patients with ischemic-type biliary strictures at a median of 2 years after liver transplantation . Findings during surgery, surgical strategies, and postsurgical courses are described . Clinical symptoms and biochemical parameters of cholestasis and liver function were analyzed in the postsurgical course . RESULTS: During surgery, all 17 patients were found to have strictures or sclerotic changes involving the hepatic bifurcation and extrahepatic bile duct . Sludge or stones were present in nine patients . In 14 patients with viable bile ducts proximal to the bifurcation, surgical reconstruction was performed by resection of the bifurcation and hepaticojejunostomy . In three patients with more extensive biliary destruction, portoenterostomy with or without peripheral hepatojejunostomy was performed . The prevalence rate of biliary infection at surgery was 93%; the predominant organisms were Candida and enterococci . The perioperative mortality rate was 0% . Clinical symptoms and biochemical parameters became normal or were considerably improved in 14 of 16 patients (88%) . CONCLUSIONS: The hepatic bifurcation seems to be a predominant site for ischemic-type biliary changes after liver transplantation . Surgical treatment by resection of the bifurcation and reconstruction by high hepaticojejunostomy is a safe and highly effective approach leading to cure or persistent major improvement in most patients.

Eur J Clin Microbiol Infect Dis, 1998 Nov, 17(11), 798 - 800
Treatment options for chronic prostatitis due to vancomycin-resistant Enterococcus faecium; Taylor SE et al.; Prostatitis due to vancomycin-resistant enterococci has not been previously described . Reported here is a case of chronic prostatitis due to Enterococcus faecium, resistant to vancomycin, ampicillin, ciprofloxacin and doxycycline, in a 42-year-old liver transplant recipient . Treatment with a combination of rifampin and nitrofurantoin for 6 weeks resulted in long-lasting cure . Other antimicrobial agents active in vitro against vancomycin-resistant enterococci, such as quinupristin/ dalfopristin and chloramphenicol, are unlikely to achieve sufficient prostatic tissue levels to be successfully utilized for treatment of this condition.

Med Clin (Barc), 1998 Dec 12, 111(20), 761 - 4
{Bacteremia due to vancomycin-resistant enterococci in neutropenic cancer patients}; Marron A et al.; BACKGROUND: The aim of this study was to determine the incidence, clinical characteristics and outcome of vancomycin-resistant enterococcal bacteremia . PATIENTS AND METHODS: We included all cases of enterococcal bacteremia in neutropenic cancer patients documented between January 1986 and December 1995 in a 1,000-bed university hospital, where a prospective surveillance of all cases of bacteremia is regularly done . Molecular typing was performed on all vancomycin-resistant strains with the analysis of chromosomic DNA by macrorestriction . RESULTS: Seventeen cases of enterococcal bacteremia were documented . Seven (41%) were caused by vancomycin-resistant strains (E . faecium 3 and E . gallinarum 4), six of which occurred in the last 5 years of the study period . The average age of patients was 43 years (18-69) and most of them had acute leukemia . Eighty percent of these patients had received vancomycin and/or cephalosporins within 2 weeks prior to bacteremia . Previous administration of antibiotics was more frequent in patients with bacteremia caused by vancomycin-resistant enterococci than in those with bacteremia caused by susceptible strains (86% vs 30%; p < 0.05) . The mean number of previous antibiotics (2.4 vs 0.8; p < 0.05) as well as days of treatment (13.6 vs 4.3; p = 0.05) were also higher among patients with resistant enterococcal bacteremia . The overall mortality was 57% . CONCLUSIONS: This study shows the emergence of sporadic cases of bacteremia caused by vancomycin-resistant enterococci in neutropenic cancer patients in our area . This fact seems to be related with the previous administration of antibiotics and advice that a rational use of these agents is needed.

FEMS Microbiol Lett, 1999 Jan 1, 170(1), 25 - 30
Strain typing among enterococci isolated from home-made Pecorino Sardo cheese; Mannu L et al.; Three molecular techniques (RAPD-polymerase chain reaction analysis, plasmid profile and pulsed-field gel electrophoresis) were used for a preliminary approach to type, at strain level, enterococci isolated from a 24-h-old home-made Pecorino Sardo (protected designation of origin) cheese . A high genetic polymorphism was found . Clusters obtained by the RAPD technique and plasmid profile analysis contained different strains . Pulsed-field gel electrophoresis proved to be an efficient and highly reproducible typing method . In addition, by combining the results from plasmid profile analysis and pulsed-field gel electrophoresis, it was possible to identify closely related strains probably belonging to the same clonal lineage.

Zentralbl Hyg Umweltmed, 1998 Dec, 201(4-5), 297 - 309
Investigation into the efficacy of disinfectants against MRSA and vancomycin-resistant enterococci; Goroncy-Bermes P; In the study reported here, several disinfectants for surfaces, instruments, hands and mucous membrane were tested for their effectiveness against methicillin-resistant strains of S . aureus and vancomycin-resistant enterococci . The results show that after use of the recommended concentrations with the recommended contact times, which were determined on the basis of the criteria for disinfectants according to the DGHM guideline for the testing and evaluation of chemical disinfection procedures, an adequate effect was able to be proved . Increased resistance of the methicillin-resistant S . aureus and vancomycin-resistant E . faecium strains to the tested disinfectants was not found . Only after use of diluted solutions differences in the bacterial count reductions were observed . In further studies it is to be investigated whether these differences are due to resistance to antibiotics or to intrinsic resistance.

J Clin Microbiol, 1999 Feb, 37(2), 413 - 6
Vancomycin-resistant Enterococcus faecium colonization in children; Singh-Naz N et al.; Nosocomial vancomycin-resistant Enterococcus (VRE) infections have been described in only small numbers of pediatric patients . In none of these studies were multivariate analyses performed to assess which factors were independent risk factors in these patients . In the present cohort study of patients admitted to our hematology/oncology unit, surveillance cultures revealed a colonization rate of 24% and all isolates were identified as Enterococcus faecium . Risk factors associated with colonization with VRE identified by multiple logistic regression analysis included young age and chemotherapy with antineoplastic agents, cefotaxime, vancomycin, and ceftazidime . A molecular epidemiological tool, pulsed-field gel electrophoresis, was used to determine the relatedness of the VRE isolates detected . DNA analysis by this method identified two major clusters of VRE isolates . Young children with gastrointestinal colonization with VRE, without evidence of clinical infection, can serve as a reservoir for the spread of VRE.

Diagn Microbiol Infect Dis, 1998 Nov, 32(3), 141 - 6
In vitro susceptibility and molecular analysis of gentamicin-resistant enterococci; Chow JW et al.; Enterococci with gentamicin MICs of 256 to 1,024 micrograms/mL were evaluated for susceptibility to ampicillin plus gentamicin synergism . Sixteen of eighteen enterococcal isolates were not susceptible to synergistic killing by ampicillin plus gentamicin; 11 possessed aac(6')-aph(2"), and 4 possessed aph(2")-Ic . A gentamicin MIC of 512 or 1,024 micrograms/mL predicted lack of ampicillin/gentamicin synergism, but a gentamicin MIC of 256 micrograms/mL did not . For six enterococcal strains possessing the gentamicin-resistance gene aph(2")-Ic, ampicillin plus dibekacin, ampicillin plus netilmicin, and ampicillin plus amikacin produced synergistic killing in five, three, and two strains, respectively.

FEMS Immunol Med Microbiol, 1998 Dec, 22(4), 283 - 91
A lipoteichoic acid fraction of Enterococcus hirae activates cultured human monocytic cells via a CD14-independent pathway to promote cytokine production, and the activity is inhibited by serum components; Arakaki R et al.; To elucidate the cellular activation mechanisms of lipoteichoic acid (LTA) compared with those of lipopolysaccharide (LPS), a quantitatively major LTA fraction, QM-1M, was prepared from hot phenol-water extracts of Enterococcus hirae (ATCC 9790) by hydrophobic octyl-Sepharose chromatography and by ion-exchange membrane (QMA-Mem Sep 1010) chromatography as a 60% 1-propanol- and 1 M NaCl-eluted fraction . Unlike the reference Escherichia coli LPS, QM-1M did not demonstrate any ability to induce cytokines in a human whole blood culture system in this study, whereas QM-1M induced a few cytokines such as interleukin (IL)-8 and tumor necrosis factor-alpha in human monocytic THP-1 cell and human peripheral mononuclear cell (PBMC) cultures in the absence of serum . Fetal calf and human sera decreased the above cytokine induction by QM-1M in THP-1 and PBMC cultures, whereas sera increased activities of the reference LPS . IL-8 induction in the absence of serum in response to QM-1M was demonstrated to proceed through a CD14-independent pathway unlike the reference LPS.

Crit Care Med, 1998 Dec, 26(12), 2001 - 4
External sources of vancomycin-resistant enterococci for intensive care units; Bonten MJ et al.; OBJECTIVE: The incidence of colonization and infection with vancomycin-resistant enterococci (VRE) has increased dramatically in the last 5 yrs, especially in intensive care units (ICUs) . We studied VRE-colonization in patients on admission to a medical ICU (MICU) where VRE colonization is endemic . DESIGN: Prospective, descriptive analysis . SETTING: An MICU of a public hospital . PATIENTS: Three hundred and one consecutively admitted patients . MEASUREMENTS AND MAIN RESULTS: Rectal swabs were obtained on admission from all patients . VRE isolates from all colonized patients were genetically fingerprinted by pulsed-field gel-electrophoresis (PFGE) . Forty-three (14%) of 301 patients were colonized with VRE on MICU admission . Three (7%) of these 43 patients were admitted directly from the community without prior hospital contact . Risk of colonization on admission was related to the length of stay in the hospital before MICU-admission (odds ratio 4.65 for patients with a stay of at least 3 days) and previous in-hospital use of antibiotics . Of 22 VRE PFGE strain types recognized in the MICU during the study period, four (18%) were introduced by patients admitted directly from the community and ten (45%) were introduced by patients admitted from other hospital wards . CONCLUSIONS: These results show that although ICUs are considered epicenters for antibiotic resistance, sources extraneous to our MICU (e.g., other wards) contributed the majority of VRE strain types in the unit.

Dis Aquat Organ, 1998 Oct 8, 34(2), 103 - 8
Enterococcus-like infections in Macrobrachium rosenbergii are exacerbated by high pH and temperature but reduced by low salinity; Cheng W et al.; Macrobrachium rosenbergii (10 to 15 g and 8 to 12 g at intermolt) were challenged with an enterococcus-like bacterium (strain KM002) previously isolated and identified as the causal agent of mortality . Challenge doses and conditions of pH, salinity and temperature were varied to determine the influence of environmental factors on the development of disease and mortality . Survival was 100% for the unchallenged control groups in all trials . In pH tests, the onset of mortality was earlier at pH 8.8 to 9.5 than at pH 4.6 to 5.2 and 7.5 to 7.7 . Also, as pH 8.8 to 9.5, all challenged prawns died within 6 d in high dose challenge tests . By contrast, 20% of the prawns challenged at pH 4.6 to 5.2 and 7.5 to 7.7 survived . At low dose challenge (5 x 10(4) cfu prawn(-1)), survival increased significantly except at pH 8.8 to 9.5 . In salinity tests at 2 challenge doses (1 x 10(6) and 2 x 10(7) cfu prawn(-1)), onset of mortality was earliest at 15 ppt and cumulative mortality was 100% at 15 ppt and 0 ppt . By contrast, survival was 80% at 5 and 10 ppt at the low dose challenge and 40% and 60%, respectively, at the high dose challenge . When the challenge dose was reduced to 5 x 10(4) cfu prawn(-1), survival was not significantly different at different salinity levels . In temperature tests at pH 7.2 to 7.5 and at 2 challenge doses (2 x 10(7) and 4 x 10(7) cfu prawn(-1)), the onset of mortality was earliest at 33 to 34 degrees C and total mortality occurred at 27 to 28 degrees C and 33 to 34 degrees C . By contrast, there were 40% and 20% survivors, respectively, for low and high challenge doses at 30 to 31 degrees C . Reducing the challenge dose to 5 x 10(4) cfu prawn(-1) gave higher survival in all groups . However, survival at 33 to 34 degrees C was still lowest . In similar temperature tests but at pH 8.8 to 9.5, onset of mortality was somewhat accelerated and there was 100% death for all the high challenge groups . At low challenge doses, mortality was lower but still highest in the 33 to 34 degrees C group . Results indicated that mortality of M . rosenbergii caused by this Enterococcus-like bacterium was exacerbated by environmental parameters of temperature and pH different from those known to be optimal for prawn growth . By contrast, low salinity appeared to have a beneficial effect on survival . Further work is needed to determine the mechanisms underlying these effects.

Arch Surg, 1998 Dec, 133(12), 1343 - 6
Third-generation cephalosporins and vancomycin as risk factors for postoperative vancomycin-resistant enterococcus infection; Dahms RA et al.; OBJECTIVE: To examine use of third-generation cephalosporins (3GCs) alone and in association with vancomycin hydrochloride as a risk factor for vancomycin-resistant enterococcus (VRE) infection in surgical patients . DESIGN: Case-control retrospective study analyzing antibiotic use in the 30 days preceding culture of VRE or vancomycin-sensitive enterococcus from an infected site . SETTING: A large tertiary care teaching hospital . PATIENTS: Surgical inpatients with VRE infections between September 3, 1993, and January 29, 1997, were matched with patients with vancomycin-sensitive enterococcus infections . Matches were based on surgical procedure, initial infection site, and immunosuppression . Matches were found for 32 of 50 surgical patients with VRE . Twenty matched pairs of patients were recipients of solid organ transplants . MAIN OUTCOME MEASURES: Multivariate logistic regression analysis was done to examine 3GCs and vancomycin as risk factors for VRE infection . Univariate analysis of use of other antibiotic agents and demographic data was also performed . RESULTS: Multivariate analysis showed significant differences in the use of 3GCs both alone and concurrently with vancomycin . Univariate analysis also showed higher use of metronidazole, concurrent vancomycin and metronidazole, concurrent vancomycin and ceftazidime, and all antibiotics combined in patients with VRE infections . CONCLUSIONS: This matched control study showed that use of 3GCs, alone (P=.05) or concurrently with vancomycin (P=.05), was a risk factor for VRE infection in surgical patients . Judicious administration of third-generation antibiotics is warranted in surgical patients with other risk factors for VRE.

J Investig Med, 1998 Dec, 46(9), 435 - 43
Investigation of an outbreak of vancomycin-resistant Enterococcus faecium in a low prevalence university hospital; Hwang YS et al.; BACKGROUND: Until 1995, there were no cases of vancomycin resistant enterococcus (VRE) identified at our university hospital . From May 1995 to August 1996, we investigated a cluster of 10 cases of phenotypic class Van B Enterococcus faecium . METHODS: Patients were matched with controls who were on the same unit for at least 7 days prior to the case developing VRE . Control patients were age and sex matched if possible, and had duration of hospitalization at least as long as the number of days it took the patient to become VRE positive . We analyzed 16 independent risk factors using Epi-info version 6 . Environmental cultures were obtained in the MICU where 5 of the patients were located . All 10 patient isolates and environmental isolates were analyzed by pulsed field gel electrophoresis (PFGE) . RESULTS: PFGE confirmed the genetic relatedness of all 10 patient isolates and environmental isolates . The VRE-positive group was more likely to be immunosuppressed and to have exposure to 3 physicians . In the MICU, significant, P < 0.05) risk factors for VRE were higher Apache scores, location adjacent to a VRE case, duration of vancomycin and amino-glycoside use, duration of invasive catheter use, and diarrhea . Among the VRE-positive environmental cultures was a blood pressure cuff wash that was used on several patients . CONCLUSION: We hypothesize that a VRE strain was introduced into our hospital environment and was spread by personnel or contaminated equipment . As a consequence of this study, a hospital-wide VRE policy was implemented.

Am J Gastroenterol, 1998 Dec, 93(12), 2491 - 500
Prospective case-cohort study of intestinal colonization with enterococci that produce extracellular superoxide and the risk for colorectal adenomas or cancer; Winters MD et al.; OBJECTIVE: The aim of this study was to determine whether intestinal colonization with enterococci that produce extracellular superoxide (O2*-), a free radical implicated in the development of colorectal cancer, is associated with these lesions or their precursors . METHODS: A prospective case-cohort study was performed by isolating enterococci from stools of consecutive patients undergoing colonoscopy who had no prior history of colonoscopy or colorectal cancer . A food frequency questionnaire was also administered to control for dietary factors known to affect the risk for these lesions . RESULTS: Among 159 evaluable participants were 77 with no precancerous or cancerous pathology, 61 with adenomas <2 cm, 10 with adenomas > or =2 cm, and 11 with cancer . Regression analyses found no associations for those subjects with adenomas of any size or with cancer and colonization with O2*--producing enterococci, any nutrient, or age . For those patients with large adenomas > or = 2 cm or cancer, however, significant associations were noted for age (OR 1.94 per decade, 95% CI 1.2-3.5), beta-carotene (OR 0.44 per 500 microg/1000 kcal/day, 95% CI 0.2-0.8), vitamin A (OR 3.20 per 500 microg/1000 kcal/day, 95% CI 1.2-8.9), and vitamin E (OR 0.09 per 10 mg/ 1000 kcal/day, 95% CI 0.006-0.9), but not colonization with O2*--producing enterococci . Second stools collected 1 yr later, however, often contained dissimilar enterococcal flora, undermining an important study assumption . CONCLUSIONS: Significant associations were found for those with large adenomas or cancer (but not small adenomas), with age, and with foods enriched for vitamin A, vitamin E, and beta-carotene . An association between colonization with O2*--producing enterococci and colorectal adenomas or cancer, however, could not be ascertained, possibly because intestinal enterococcal flora changes over time, leaving a potentially cohesive hypothesis of colon cancer and risk factors as yet unanswered.

J Antimicrob Chemother, 1998 Nov, 42(5), 605 - 12
Molecular analysis of diverse elements mediating VanA glycopeptide resistance in enterococci; Palepou MF et al.; Differences were examined among 24 distinct elements mediating VanA-type glycopeptide resistance in enterococci isolated from hospital patients and non-human sources in the UK . The methods used included long-PCR restriction fragment length polymorphism (L-PCR RFLP) analysis and DNA hybridization . All elements had conserved vanRSHAX genes, but variation occurred upstream of vanR and downstream of vanX . Twenty-one VanA elements had significant alterations upstream of vanR in the transposition genes orf1 and orf2: either parts of these genes were absent or they were disrupted by IS1216V or IS3-like insertion sequences . Among VanA elements with alterations downstream of vanX, seven lacked vanY, one lacked both vanY and vanZ, and ten had copies of insertion sequence IS1216V between vanX and vanY . All VanA elements of group D (from geographically and temporally diverse enterococci) were characterized by the presence of an IS1216V/IS3-like/orf1 complex and a point mutation in vanX, both of which were absent from the other 23 groups of VanA elements . This finding is consistent with the dissemination of a stable resistance element . We conclude that L-PCR RFLP analysis, combined with DNA hybridization, merits further development for studying the evolution and epidemiology of VanA resistance elements in enterococci.

Tidsskr Nor Laegeforen, 1998 Oct 30, 118(26), 4070 - 3
{Infections caused by multiresistant enterococci in Norway}; Harthug S et al.; During the last decade antimicrobial resistant pathogens have become a major medical problem . Internationally, multiresistant enterococci have increased nosocomial morbidity and mortality . Such strains are often resistant to ampicillin, aminoglycosides, and glycopeptides such as vancomycin . The spread of these strains has been shown to correlate to the use of antibiotics and the practice of suboptimal infection control within health care facilities . The current situation in Norwegian hospitals is presented, including the only six cases with infections and the three carriers of vancomycin resistant enterococci found to date . Surveillance in the hospitals shows that such strains are uncommon in non-infected patients . To maintain this favourable situation it is necessary to continue to practice effective methods of infection control and to employ sound antibiotic policies.

J Infect Dis, 1999 Jan, 179(1), 163 - 71
The changing molecular epidemiology and establishment of endemicity of vancomycin resistance in enterococci at one hospital over a 6-year period; Kim WJ et al.; The contributions of clonal spread, transfer of genetic elements, and introduction of new strains to the establishment of endemicity of vancomycin-resistant enterococci (VRE) were determined . The study took place at one hospital between 1990, when VRE were first detected, and 1996, when endemicity had become established . Isolates from 183 patients were categorized into 24 strain types by pulsed-field gel electrophoresis; the resistance genotype was determined by polymerase chain reaction . Between 1990 and 1993, 69% of patients were infected with the same vanB Enterococcus faecium strain . VanA resistance was not detected until 1993, but in 1996, the ratio of vanA to vanB was 2.2:1 . Over time, 8 vanA strains were detected; a 35- or 40-kb conjugative vanA plasmid was found in 4 of the 8 strains . Clonal spread was a major factor in the establishment of endemicity . Transfer of genetic elements and introduction of new strain types were detected less often . However, these events may have been equally important evolutionarily.

Am J Infect Control, 1998 Dec, 26(6), 569 - 71
Detection of vancomycin-resistant enterococci colonization in a children's hospital; Christenson JC et al.; BACKGROUND: Vancomycin-resistant enterococci (VRE) are important nosocomial pathogens in many hospitals . The true prevalence of VRE in pediatric hospitals is not known . METHODS: A surveillance study was performed at a pediatric tertiary care medical center by using vancomycin-containing screening media . RESULTS: Six children (of 112 screened) were found to be colonized with VRE . Colonized patients had a history of receiving broad-spectrum antimicrobial agents . CONCLUSION: In the absence of VRE infections, surveillance studies can help determine the extent of VRE colonization and support infection control measures.

Antimicrob Agents Chemother, 1998 Dec, 42(12), 3279 - 81
In vitro activity of the new ketolide HMR3647 in comparison with those of macrolides and pristinamycins against Enterococcus spp; Torres C et al.; Ninety-four erythromycin-susceptible and 107 erythromycin-resistant enterococcal strains (MIC of >/=512 microgram/ml) were inhibited by the ketolide HMR3647 at MICs of </=0.007 to 0.06 and 0.03 to 8 microgram/ml, respectively . Eighteen vanA-positive isolates and 29 high-level-penicillin-resistant isolates, all of them erythromycin resistant, were inhibited by HMR3647 at an MIC range of 0.015 to 4 microgram/ml . The new ketolide has excellent activity against Enterococcus species.

J Hosp Infect, 1998 Nov, 40(3), 237 - 41
The toilet as a transmission vector of vancomycin-resistant enterococci; Noble MA et al.; An elderly woman, admitted to the intensive care unit of a large university teaching hospital, was found to be colonized with vancomycin-resistant enterococci leading to the temporary closure of the unit . She had acquired the organism nosocomially, most likely from an environmental source, which had been contaminated when the toilet of a former patient, also colonized with vancomycin-resistant enterococci, had become blocked and overflowed throughout his and the adjoining room . This is the first report of a hospital toilet as the transmission vector for vancomycin-resistant enterococci.

Mem Inst Oswaldo Cruz, 1998 Sep-Oct, 93(5), 587 - 8
Vancomycin-resistant enterococci in intensive care hospital settings; Austin DJ et al.; Vancomycin-resistant enterococci (VRE) have recently emerged as a nosocomial pathogen and present an increasing threat to the treatment of severely ill patients in intensive-care hospital settings . We outline results of a study of the epidemiology of VRE transmission in ICUs and define a reproductive number R0; the number of secondary colonization cases induced by a single VRE-colonized patient in a VRE-free ICU, for VRE transmission . For VRE to become endemic requires R0 > 1 . We estimate that in the absence of infection control measures R0 lies in the range 3-4 in defined ICU settings . Once infection control measures are included R0 = 0.6, suggesting that admission of VRE-colonized patients can stabilize endemic VRE.

J Food Prot, 1998 Nov, 61(11), 1454 - 8
Growth and adherence on stainless steel by Enterococcus faecium cells; Andrade NJ et al.; Enterococcus faecium isolated from Brazilian raw milk was used in this study . For growth studies, E . faecium was inoculated into 10% RSM (reconstituted skim milk) and MRS both, incubated at 6.5 and 9 degrees C for 10 days and at 30, 42, and 45 degrees C for 48 h . Cells were enumerated after spread-plating onto MRS agar and incubating at 30 degrees C for 48 h . The ability of E . faecium cells to adhere to stainless-steel chips (6 by 6 by 1 mm, AISI 304, finish #4) was investigated . MRS broth containing stainless steel chips was inoculated to an initial concentration of 10(3) or 10(6) CFU/ml of E . faecium . Adherent cells were stained with acridine orange and enumerated by epifluorescence microscopy . E . faecium grew between 6.5 and 42 degrees C in MRS and between 9 and 40 degrees C in RSM . In MRS broth with 10(6) or 10(3) CFU/ml, the g (generation time) values were 0.62 and 0.42 h and R (growth rate) values were 1.6 and 2.4 h-1 . Values of R = 2.3 h-1 and g = 0.43 h were determined for E . faecium growing in RSM with 10(3) CFU/ml . In MRS broth, for samples with a starting concentration of 10(6) cells per ml, adherence to stainless-steel chips was first observed at 2 h . However, adherence was first observed at 4 h in samples with an initial concentration of 10(3) cells per ml . After 10 h of exposure the number of adherent cells was similar for all samples regardless of initial inoculum . These results indicate that E . faecium readily adheres to stainless steel . It also underscores the need to control E . faecium by using appropriate low storage temperatures and adequate sanitizing practices in the dairy industry.

Clin Infect Dis, 1998 Nov, 27(5), 1259 - 65
The role of chloramphenicol in the treatment of bloodstream infection due to vancomycin-resistant Enterococcus; Lautenbach E et al.; The incidence of bacteremia due to vancomycin-resistant Enterococcus (VRE) has increased markedly in recent years . We investigated the role of chloramphenicol in its treatment . All cases of VRE bacteremia occurring at our facility during a 45-month period were analyzed . The response to chloramphenicol, its effect on mortality, and the incidence of adverse effects were assessed . Fifty-one patients (65.4%) received chloramphenicol . Among patients in whom a response could be assessed, 22 (61.1%) of 36 demonstrated a clinical response, while 34 (79.1%) of 43 showed a microbiological response . Forty-two patients (53.8%) died as a result of the bacteremia . Although the mortality rate was lower for patients treated with chloramphenicol, the difference was not significant (odds ratio = 0.72; 95% confidence interval, 0.28-1.85; P = .49), nor was there an association between earlier initiation of therapy and reduced mortality (P = .45) . In cases with central line-related bacteremia, there was no difference in mortality among patients treated with chloramphenicol, line removal, or both (P = .36) . Although 16 patients (31.4%) had adverse effects, none could be definitely attributed to chloramphenicol . Although chloramphenicol was well-tolerated, no significant effect of its use on mortality could be demonstrated.

Infect Immun, 1998 Dec, 66(12), 6022 - 3
Correlation of cecal microflora of HLA-B27 transgenic rats with inflammatory bowel disease; Onderdonk AB et al.; Transgenic rats with a high level of expression of the human major histocompatibility complex class I molecule HLA-B27 develop chronic inflammatory bowel disease (IBD) and arthritis . Assessment of the cecal microflora showed a rise in numbers of Escherichia coli and Enterococcus spp., corresponding to the presence and severity of IBD in these rats.

J Am Med Inform Assoc, 1998 Nov-Dec, 5(6), 554 - 62
Reducing vancomycin use utilizing a computer guideline: results of a randomized controlled trial; Shojania KG et al.; BACKGROUND: Vancomycin-resistant enterococci represent an increasingly important cause of nosocomial infections . Minimizing vancomycin use represents a key strategy in preventing the spread of these infections . OBJECTIVE: To determine whether a structured ordering intervention using computerized physician order entry that requires use of a guideline could reduce intravenous vancomycin use . DESIGN: Randomized controlled trial assessing frequency and duration of vancomycin therapy by physicians . PARTICIPANTS AND SETTING: Three hundred ninety-six physicians and 1,798 patients in a tertiary-care teaching hospital . INTERVENTION: Computer screen displaying, at the time of physician order entry, an adaptation of the Centers for Disease Control and Prevention guidelines for appropriate vancomycin use . MAIN OUTCOME MEASURES: The frequency of initiation and renewal of vancomycin therapy as well the duration of therapy prescribed on a per prescriber basis . RESULTS: Compared with the control group, intervention physicians wrote 32 percent fewer orders (11.3 versus 16.7 orders per physician; P = 0.04) and had 28 percent fewer patients for whom they either initiated or renewed an order for vancomycin (7.4 versus 10.3 orders per physician; P = 0.02) . In addition, the duration of vancomycin therapy attributable to physicians in the intervention group was 36 percent lower than the duration of therapy prescribed by control physicians (26.5 versus 41.2 days; P = 0.05) . Analysis of pharmacy data confirmed a decrease in the overall hospital use of intravenous vancomycin during the study period . CONCLUSION: Implementation of a computerized guideline using physician order entry decreased vancomycin use . Computerized guidelines represent a promising tool for changing prescribing practices.

Diagn Microbiol Infect Dis, 1998 Oct, 32(2), 95 - 9
In vitro activity of RPR 106972 alone and in combination with vancomycin, ampicillin, and gentamicin against multidrug-resistant enterococci; Messick CR et al.; This investigation used checkerboard and time-kill assays to evaluate the in vitro activity of RPR 106972 (45% pristinamycin IB and 55% pristinamycin IIB) alone and in combination with vancomycin or ampicillin +/- gentamicin against multidrug-resistant enterococci . The checkerboard procedure resulted in synergistic or additive effects in 91% of the isolates with the combination of RPR 106972 plus vancomycin versus 68% with RPR 106972 plus ampicillin . The addition of gentamicin to either combination resulted in synergistic or additive results in 100% of the isolates . Inhibitory activity was observed with the time-kill assay with mean change in log10 CFU/mL at 24 h of -0.31 for RPR 106972, 3.3 for vancomycin, -0.46 for RPR 106972 plus vancomycin, and -0.35 for RPR 106972 plus vancomycin and gentamicin . No antagonism was noted with any of the combinations . RPR 106972 demonstrates good inhibitory activity against Enterococcus faecium and may prove useful in the treatment of enterococcal infections.

Int Endod J, 1998 Jan, 31(1), 1 - 7
Microbiological status of root-filled teeth with apical periodontitis; Molander A et al.; The present study examined the microbiological status of 100 root-filled teeth with radiographically verified apical periodontitis--the pathology (P) group--and of 20 teeth without signs of periapical pathosis--the technical (T) group . In the P group 117 strains of bacteria were recovered in 68 teeth . In most of the cases examined one or two strains were found . Facultative anaerobic species predominated among these isolates (69% of identified strains) . Growth was classified as 'sparse' or 'very sparse' in 53%, and as 'heavy' or 'very heavy' in 42% . Enterococci were the most frequently isolated genera, showing 'heavy' or 'very heavy' growth in 25 out of 32 cases (78%) . In 11 teeth of the T group no bacteria were recovered, whilst the remaining nine yielded 13 microbial strains . Eight of these grew 'very sparsely' . It is concluded that the microflora of the obturated canal differs from that found normally in the untreated necrotic dental pulp, quantitatively as well as qualitatively . Nonsurgical retreatment strategies should be reconsidered.

J Infect, 1998 May, 36(3), 324 - 7
RP59500 (Quinupristin/dalfopristin): three case reports of its use in infection due to Enterococcus faecium; Cassell J et al.; We describe three cases of Enterococcus faecium sepsis arising in immunocompromised patients, severely ill with other conditions, who were treated with the new injectable streptogramin RP59500 . There are still few reports of clinical experience with this drug . All had bacteriological resolution, with one patient recovering fully . Although two of the three patients died, this was due to underlying disease in one case and a gram-negative superinfection in another . Quinupristin/dalfopristin therapy was not associated with significant adverse effects in any of the patients.

FEMS Microbiol Lett, 1998 Nov 1, 168(1), 145 - 51
Detection of the satA gene and transferability of virginiamycin resistance in Enterococcus faecium from food-animals; Hammerum AM et al.; The satA gene encoding streptogramin A resistance was detected in virginiamycin-resistant Enterococcus faecium isolates from pigs and broilers . The satA gene was present in 22 of 89 (25%) virginiamycin-resistant E . faecium isolates . It was shown that the satA gene and other gene(s) encoding streptogramin resistance could be transferred between isogenic E . faecium strains at frequencies ranging from 2.3 x 10(-4) to 2.2 x 10(-3) transconjugants per donor.

Eur J Clin Microbiol Infect Dis, 1998 Aug, 17(8), 576 - 7
Enterococcus hirae septicemia in a patient with end-stage renal disease undergoing hemodialysis; Gilad J et al.; Enterococcus hirae, member of the Enterococcus genus known to cause infection in animals, is rarely encountered in clinical practice . There are no published reports describing clinical features of Enterococcus hirae infection in humans . A case of Enterococcus hirae septicemia in a 49-year-old patient with end-stage renal disease undergoing hemodialysis is reported here . A review of the available literature regarding the clinical spectrum of Enterococcus hirae infection in humans and the antimicrobial susceptibility of Enterococcus hirae is also included.

Presse Med, 1998 Sep 26, 27(28), 1427 - 9
{Vancomycin resistant enterococcus in France . High prevalence in a young ambulatory care patient population}; Guerin F et al.; OBJECTIVE: Assess the prevalence of asymptomatic carriage of vancomycin-resistant Enterococci in a population of healthy young French subjects . METHODS: Stool samples obtained from 100 persons living in south-eastern France (20 sampling sites) were directly seeded on enriched selective media containing 6 mg/l vancomycin . Bacterial species and their resistant gene were identified with classical methods and multiplex genomic amplification . RESULTS: The incidence of asymptomatic carriage was 17% with a homogeneous geographic distribution of the resistant strains . Nine Enterococcus faecium van A strains and 8 E . gallinarum van C1 strains were isolated . CONCLUSION: These findings demonstrate carriage of vancomycin-resistant Enterococci in a population of young ambulatory subjects in France . The incidence observed was much higher than in an earlier study conducted in France . These results might be explained by a much more sensitive detection technique . Care should be taken to avoid dissemination in hospital settings.

ANNA J, 1998 Aug, 25(4), 381 - 6; quiz 387-8
Vancomycin resistant enterococcus in a hospital-based dialysis unit; Korff A et al.; OBJECTIVE: The emergence of vancomycin resistant enterococcus (VRE) poses a serious threat to the health care community . Reservoirs of VRE are thought to exist in certain high-risk patient groups who reintroduce the organism into the hospital environment . The frequent use of vancomycin in dialysis patients may place this population at higher risk of developing VRE . This article describes the development of VRE and a point prevalence study conducted in a hospital-based dialysis unit . SETTING/SAMPLE: A dialysis unit of a tertiary care center in the eastern United States was selected as the study site . Patients who agreed to participate in the study after giving informed consent were included . Of the 85 members of this target population 33 (38.8%) agreed to participate in the study . The duration of the study was 30 days . DESIGN: After the literature was reviewed, a point prevalence study was completed at the study site . Stool samples or rectal swabs were collected from the study participants and analyzed for the presence of VRE . A chart review of patient demographic and prior treatment information was completed in order to help identify factors that correlate to the presence of VRE . METHODS: Stool or rectal swab samples were cultured on selective media and sensitivity to vancomycin was measured . RESULTS: A 9.1% prevalence of VRE was detected within the study group . The number of VRE positive subjects (3) did not allow statistically significant correlation with the demographic and prior treatment data collected . CONCLUSION: Although VRE remains a serious threat to the health care community, the prevalence of VRE within the study group does not vary markedly from rates previously reported.

J Bacteriol, 1998 Nov, 180(21), 5792 - 5
DdlN from vancomycin-producing Amycolatopsis orientalis C329.2 is a VanA homologue with D-alanyl-D-lactate ligase activity; Marshall CG et al.; Vancomycin-resistant enterococci acquire high-level resistance to glycopeptide antibiotics through the synthesis of peptidoglycan terminating in D-alanyl-D-lactate . A key enzyme in this process is a D-alanyl-D-alanine ligase homologue, VanA or VanB, which preferentially catalyzes the synthesis of the depsipeptide D-alanyl-D-lactate . We report the overexpression, purification, and enzymatic characterization of DdlN, a VanA and VanB homologue encoded by a gene of the vancomycin-producing organism Amycolatopsis orientalis C329.2 . Evaluation of kinetic parameters for the synthesis of peptides and depsipeptides revealed a close relationship between VanA and DdlN in that depsipeptide formation was kinetically preferred at physiologic pH; however, the DdlN enzyme demonstrated a narrower substrate specificity and commensurately increased affinity for D-lactate in the C-terminal position over VanA . The results of these functional experiments also reinforce the results of previous studies that demonstrated that glycopeptide resistance enzymes from glycopeptide-producing bacteria are potential sources of resistance enzymes in clinically relevant bacteria.

J Med Microbiol, 1998 Oct, 47(10), 849 - 62
Glycopeptide-resistant enterococci: a decade of experience; Woodford N; Since their first description in 1988, glycopeptide-resistant enterococci (GRE) have emerged as a significant cause of nosocomial infections and colonisations, particularly in Europe and the USA . Two major genetically distinct forms of acquired resistance, designated VanA and VanB, are recognised, although intrinsic resistance occurs in some enterococcal species (VanC) and a third form of acquired resistance (VanD) has been reported recently . The biochemical basis of each resistance mechanism is similar; the resistant enterococci produce modified peptidoglycan precursors that show decreased binding affinity for glycopeptide antibiotics . Although VanA resistance is detected readily in the clinical laboratory, the variable levels of vancomycin resistance associated with the other phenotypes makes detection less reliable . Under-reporting of VanB resistance as a result of a lower detection rate may account, in part, for the difference in the numbers of enterococci displaying VanA and VanB resistance referred to the PHLS Laboratory of Hospital Infection . Since 1987, GRE have been referred from >1100 patients in almost 100 hospitals, but 88% of these isolates displayed the VanA phenotype . It is possible that, in addition to the problems of detection, there may be a real difference in the prevalence of VanA and VanB resistance reflecting different epidemiologies . Our present understanding of the genetic and biochemical basis of these acquired forms of glycopeptide resistance has been gained mainly in the last 5 years . However, these relatively new enterococcal resistances appear still to be evolving; there have now been reports of transferable VanB resistance associated with either large chromosomally borne transposons or plasmids, genetic linkage of glycopeptide resistance and genes conferring high-level resistance to aminoglycoside antibiotics, epidemic strains of glycopeptide-resistant Enterococcus faecium isolated from multiple patients in numerous hospitals, and of glycopeptide dependence (mutant enterococci that actually require these agents for growth) . The gene clusters responsible for VanA and VanB resistance are located on transposable elements, and both transposition and plasmid transfer have resulted in the dissemination of these resistance genes into diverse strains of several species of enterococci . Despite extensive research, knowledge of the origins of these resistances remains poor . There is little homology between the resistance genes and DNA from either intrinsically resistant gram-positive genera or from the soil bacteria that produce glycopeptides, which argues against direct transfer to enterococci from these sources . However, recent data suggest a more distant, evolutionary relationship with genes found in glycopeptide-producing bacteria . In Europe, VanA resistance occurs in enterococci isolated in the community, from sewage, animal faeces and raw meat . This reservoir suggests that VanA may not have evolved in hospitals, and its existence has been attributed, controversially, to use of the glycopeptide avoparcin as a growth promoter, especially in pigs and poultry . However, as avoparcin has never been licensed for use in the USA and, to date, VanB resistance has not been confirmed in non-human enterococci, it is clear that the epidemiology of acquired glycopeptide resistance in enterococci is complex, with many factors contributing to its evolution and global dissemination.

Syst Appl Microbiol, 1998 Aug, 21(3), 450 - 3
Application of 23S rDNA-targeted oligonucleotide probes specific for enterococci to water hygiene control; Frahm E et al.; Identification of enterococci species by hybridization with recently designed species-specific and group-specific 23S rDNA-targeted oligonucleotide probes was superior to results obtained with a common biochemical test panel . Considering these findings, a molecular biological procedure for the detection of enterococci in water samples was developed . A short enrichment is followed by an amplification step and a hybridization reaction in microtiter plate format . The detection limit is about 1 CFU/ml, and results are available within 26 h.

Infect Control Hosp Epidemiol, 1998 Sep, 19(9), 647 - 52
Failure to eradicate vancomycin-resistant enterococci in a university hospital and the cost of barrier precautions; Lai KK et al.; OBJECTIVE: To describe the effect of infection control interventions on the incidence of vancomycin-resistant enterococci (VRE), the utility of pharyngeal cultures for surveillance for VRE colonization, and the cost of barrier precautions . DESIGN: Evaluation of the occurrence of VRE infection or colonization, rates of vancomycin use, results of surveillance cultures before and after interventions, and the cost of increased barrier precautions . SETTING: University of Massachusetts Medical Center, a 347-bed tertiary-care teaching hospital with eight intensive-care units, one burn unit, and one bone marrow transplant unit . PARTICIPANTS: Patients in the intensive-care units and staff who were involved with patients colonized or infected with VRE . METHODS: Infection control interventions included placement of patients with VRE in private rooms, strict contact isolation, cohorting of patient and nursing staff, prohibiting of equipment sharing, and monitoring of compliance with the vancomycin restriction policy, with hand washing, and of the adequacy of environmental cleaning . Both rectal and pharyngeal cultures were obtained from patients at the beginning of the outbreak, and the utility of pharyngeal cultures was evaluated . The cost of barrier precautions was estimated by comparing the cost of glove and gown use before and after the outbreak began . RESULTS: The interventions decreased the number of new cases of VRE, but total eradication of VRE was not achieved . Compliance with the room-cleaning protocol was 91% (141/155 observations) . Hand washing following interaction with patients who were not in isolation was 51%, vs 100% for patients in isolation . Overall, handwashing compliance was 71% (319/449): 56% (130/231) for physicians and 86% (187/218) for nurses (P<.0001) . The mean number of doses of vancomycin dispensed per 1,000 patient days decreased from 145 to 114 per 1,000 patient days (P<.001) . Compliance with vancomycin-use guidelines was 85% . Forty-six (77%) of 60 surveillance rectal swabs yielded enterococci, as compared to only 4 (11%) of 36 pharyngeal cultures (P<.0001) . Expenses on glove and gowns alone increased by over $11,000 per year since the epidemic began . CONCLUSIONS: Implementation of the various infection control measures did not eradicate VRE cases from the hospital . Rectal cultures were more useful than pharyngeal cultures for surveillance of VRE . Controlling VRE epidemics can be costly.

J Clin Microbiol, 1998 Nov, 36(11), 3327 - 31
Comparison of genomic methods for differentiating strains of Enterococcus faecium: assessment using clinical epidemiologic data; Savor C et al.; Genomic DNA extracted from 45 vancomycin-resistant Enterococcus faecium (VRE) isolates was cleaved with HindIII and HaeIII and subjected to agarose gel electrophoresis . The ability of this method (restriction endonuclease analysis {REA}) to distinguish strains at the subspecies level was compared with results previously determined by pulsed-field gel electrophoresis (PFGE) . Chart reviews were performed to provide a clinical correlation of possible epidemiologic relatedness . A likely clinical association was found for 29 patients as part of two outbreaks . REA found 21 of 21 isolates were the same type in the first outbreak, with PFGE calling 19 strains the same type . In the second outbreak with eight patient isolates, HindIII found six were the same type and two were unique types . HaeIII found three strains were the same type, two strains were a separate type, and three more strains were unique types, while PFGE found three were the same type and five were unique types . No single "ideal" method can be used without clinical epidemiologic investigation, but any of these techniques is helpful in providing focus to infection control practitioners assessing possible outbreaks of nosocomial infection.

J Clin Microbiol, 1998 Nov, 36(11), 3303 - 8
Molecular analysis of glycopeptide-resistant Enterococcus faecium isolates collected from Michigan hospitals over a 6-year period; Thal L et al.; The purpose of this study was to evaluate the molecular relatedness of clinical isolates of glycopeptide-resistant Enterococcus faecium isolates collected from hospitals in Michigan . A total of 379 isolates used in this study were all vancomycin-resistant E . faecium isolates collected from 28 hospitals and three extended-care facilities over a 6-year period from 1991 to 1996 . For the 379 isolates, there were 73 pulsed-field gel electrophoresis (PFGE) strain types . Within strain types, there were as many as six restriction fragment differences . Most isolates (70%) belonged to six strain types, which were designated M1 (36%), M2 (3%), M3 (18%), M4 (6%), M10 (4%), and M11 (3%) . PFGE strain M1 was cultured from 135 patients in 13 hospitals during the period 1993 to 1996 . Strain type M2 was cultured from 11 patients in two hospitals during the period 1991 to 1992 and was not observed after 1992 . Strain type M3 was cultured from 70 patients in 10 hospitals during the period of 1994 to 1996 . Both M4 and M10 were cultured from 23 patients in three hospitals and from 15 patients in two hospitals, respectively, during 1995 to 1996 . M11 was cultured from 13 patients in four hospitals during 1996 . A total of 23 of 28 hospitals had evidence of clonal dissemination of some isolates . Plasmid content and hybridization analysis done on 103 isolates from one hospital and two affiliated extended-care facilities indicated that the strains contained from one to eight plasmids . Mating experiments indicated transfer of vancomycin resistance from 94 of these isolates into plasmid-free E . faecium GE-1 at transfer frequencies of <10(-9) to 10(-4) . Gentamicin resistance and erythromycin resistance were cotransferred at various frequencies . A probe for the vanA gene hybridized to the plasmids of 23 isolates and to the chromosomes of 72 isolates . A probe for the vanB gene hybridized to the chromosomes of 8 isolates . The results of this study suggest inter- and intrahospital dissemination of vancomycin-resistant E . faecium strains over a 6-year period in southeastern Michigan . The majority of isolates studied belonged to the same few PFGE strains, indicating that clonal dissemination was responsible for most of the spread of resistance that occurred.

Zhonghua Yi Xue Za Zhi, 1997 May, 77(5), 327 - 31
{Trends and changes in antimicrobial resistance of clinical isolates from 11 hospitals in Beijing area}; Zhang F et al.; OBJECTIVE: To study the antimicrobial resistance and its changes of clinical isolates in Beijing area . METHODS: The diameters of the inhibition zones of clinical isolates around antibiotic susceptibility test discs at 12 hospitals in Beijing area were computerfiled and analysed by the software of 'WHONET' according to NCCLS published in 1994 . RESULTS: A total of 10,305 isolates were collected in 1995 . The percentages of resistance were as follows: (1) in E . coli: amikacin, 8%, ceftazidime, 15%, the other third generation cephalosporins, about 30%, (2) in Klebsiella spp: ofloxacin, 0%, ceftazidime, 15%, ciprofloxacin, 17%, norfloxacin, 15%, ofloxacin, 5%, (4) in Staph . aureus: norvancomycin, 0%, (5) in Strep . pneumoniae: penicillin G, 9%, (6) in Enterococcus spp: norvancomycin, 7% . The antimicrobial resistant changes over a six year period from 1990 to 1995 were surveyed and it was found that resistant percentage of the most isolates to quinolones, for example norfloxacin, increased significantly year by year and no remarkable differences of resistance to antimicrobial agents but quinolones were observed in Ps . aeruginosa . CONCLUSION: Antimicrobial resistance should be emphasised during clinical therapy with antimicrobial agents, and trends in antimicrobial resistance of isolates should be followed.

J Natl Med Assoc, 1998 Sep, 90(9), 537 - 40
Multidrug-resistant enterococci: the dawn of a new era in resistant pathogens; Antony SJ; Resistant enterococci, especially vancomycin-resistant enterococci, have rapidly become an important nosocomial pathogen . They are increasingly prevalent among hospitalized patients, patients with serious chronic illnesses, and immunosuppressed patients . Risk factors identified include previous antibiotics, exposure to contaminated equipment, and close proximity to infected patients . Treatment of multidrug-resistant pathogens has become increasingly difficult, with increased morbidity and mortality in these patients . Strict infection control measures remain the mainstay in the management of these infections.

FEMS Microbiol Lett, 1998 Sep 15, 166(2), 355 - 60
The PBP 5 synthesis repressor (psr) gene of Enterococcus hirae ATCC 9790 is substantially longer than previously reported; Massidda O et al.; A reexamination of the nucleotide sequence of the psr gene of Enterococcus hirae revealed the presence of two additional nucleotides at residues 1190 and 1191 . As a result, instead of a stop codon after 148 aa, the psr gene product would contain 293 aa residues . The revised size of the gene product was confirmed by subsequently cloning and expressing the psr gene in Escherichia coli . The derived amino acid sequence of the revised psr gene product was found to be similar to several other proteins in the combined GenBank/EMBL database . The protein products of some of these genes are thought to play regulatory role(s) in exo or capsular polysaccharide synthesis and/or in cell wall metabolism . All the putative homologs of the revised Psr appear to have a putative membrane-anchoring domain at their N-termini . Amino acid blocks with high degrees of similarity have been identified in the aligned sequences, and it is suggested that these common motifs could be of structural or functional importance.

Diagn Microbiol Infect Dis, 1998 Aug, 31(4), 525 - 30
Colonization and microbiology of the motile enterococci in a patient population; Van Horn KG et al.; The motile enterococci with the vanC gene have intrinsic low-level resistance to vancomycin, but have not been implicated in a nosocomial outbreak . We determined the colonization rate of motile enterococci in hospitalized and nonhospitalized patients . Perianal or stool specimens were cultured in Enterococcosel broth supplemented with 6 micrograms of vancomycin per mL . Rapid motility and pigment tests were performed on all enterococci isolated . A total of 82 motile and/or pigmented enterococci were isolated from 679 patients for a colonization rate of 12.1% . There were 43 Enterococcus gallinarum, 32 Enterococcus casseliflavus, 4 Enterococcus flavescens, and 3 Enterococcus mundtii identified . The E . gallinarum vancomycin MIC90 was 32 micrograms/mL and the E . casseliflavus vancomycin MIC90 was 8 micrograms/mL.

Infect Control Hosp Epidemiol, 1998 Aug, 19(8), 546 - 51
Spread of vancomycin-resistant enterococci: differences between the United States and Europe; Goossens H; There are major differences in the epidemiology of vancomycin-resistant enterococci (VRE) between the United States and Europe . In contrast with Europe, VRE in the United States are resistant to many antibiotics, and there appears to be less genetic variability among these isolates . European VRE of human origin are usually susceptible to many other antibiotics and are highly polyclonal . These clinical isolates have the same susceptibility profiles as VRE isolated from animals . The differences in the spread of VRE between the United States and Europe might be explained by the overconsumption of glycopeptides and other antibiotics in hospitals in the United States and the use of avoparcin as a growth promotor in Europe.

Antimicrob Agents Chemother, 1998 Oct, 42(10), 2710 - 7
Treatment of vancomycin-resistant Enterococcus faecium with RP 59500 (quinupristin-dalfopristin) administered by intermittent or continuous infusion, alone or in combination with doxycycline, in an in vitro pharmacodynamic infection model with simulated endocardial vegetations; Aeschlimann JR et al.; Quinupristin-dalfopristin is a streptogramin antibiotic combination with activity against vancomycin-resistant Enterococcus faecium (VREF), but emergence of resistance has been recently reported . We studied the activity of quinupristin-dalfopristin against two clinical strains of VREF (12311 and 12366) in an in vitro pharmacodynamic model with simulated endocardial vegetations (SEVs) to determine the potential for resistance selection and possible strategies for prevention . Baseline MICs/minimal bactericidal concentrations (microg/ml) for quinupristin-dalfopristin, quinupristin, dalfopristin, and doxycycline were 0.25/2, 64/>512, 4/512, and 0.125/8 for VREF 12311 and 0.25/32, 128/>512, 2/128, and 0.25/16 for VREF 12366, respectively . Quinupristin-dalfopristin regimens had significantly less activity against VREF 12366 than VREF 12311 . An 8-microg/ml simulated continuous infusion was the only bactericidal regimen with time to 99.9% killing = 90 hours . The combination of quinupristin-dalfopristin every 8 h with doxycycline resulted in more killing compared to either drug alone . Quinupristin-dalfopristin-resistant mutants (MICs, 4 microg/ml; resistance proportion, approximately 4 x 10(-4)) emerged during the quinupristin-dalfopristin monotherapies for both VREF strains . Resistance was unstable in VREF 12311 and stable in VREF 12366 . The 8-microg/ml continuous infusion or addition of doxycycline to quinupristin-dalfopristin prevented the emergence of resistance for both strains over the 96-h test period . These findings replicated the development of resistance reported in humans and emphasized bacterial factors (drug susceptibility, high inoculum, organism growth phase) and infectious conditions (penetration barriers) which could increase chances for clinical resistance . The combination of quinupristin-dalfopristin with doxycycline and the administration of quinupristin-dalfopristin as a high-dose continuous infusion warrant further study to determine their potential clinical utility.

Antimicrob Agents Chemother, 1998 Oct, 42(10), 2564 - 8
Comparison of inhibitory and bactericidal activities and postantibiotic effects of LY333328 and ampicillin used singly and in combination against vancomycin-resistant Enterococcus faecium; Baltch AL et al.; One hundred ninety-five individual vancomycin-resistant Enterococcus faecium (VRE) isolates from five upstate New York hospitals were studied for antimicrobial susceptibilities to LY333328, quinupristin-dalfopristin, teicoplanin, ampicillin, and gentamicin . LY333328 was the most active antibiotic against VRE . The effect of media and methods on the antibacterial activity of LY333328, its synergy with ampicillin, and the postantibiotic effects (PAE) of LY333328 and ampicillin were evaluated . In microdilution tests, the MIC of LY333328 at which 90% of the isolates were inhibited (MIC90) was 2 microg/ml in Mueller-Hinton II (MH II) broth and 1 microg/ml in brain heart infusion (BHI) broth . In contrast, on MH II agar the MIC90 was 4 microg/ml and on BHI agar it was >16 microg/ml . Bactericidal activity was observed for most strains at concentrations from 8 to >/=133 times the MIC of the tube macrodilution in MH II broth . A bactericidal effect of LY333328 plus ampicillin was demonstrated in time-kill studies, but there was great strain-to-strain variability . By the MH II agar dilution method, bacteristatic synergy (defined as a fractional inhibitory concentration of <0.5) with LY333328 and ampicillin was demonstrated for 61% of the strains tested . Under similar conditions, there was synergy with LY333328 and quinupristin-dalfopristin or gentamicin for 27 and 15% of the strains tested, respectively . The PAE of LY333328 was prolonged (23.0 h at 10 times the MIC) . However, 50% normal pooled human serum decreased the PAE to 12.2 h at 10 times the MIC . Test conditions and media had a considerable effect on VRE susceptibilities to LY333328 . The prolonged PAE of LY333328, a potent new bactericidal glycopeptide, and its synergy with ampicillin in a large proportion of strains suggest that further evaluation of this drug in pharmacokinetic studies and experimental infections, including those with VRE, is warranted.

Chem Biol, 1998 Sep, 5(9), 489 - 504
Homologs of the vancomycin resistance D-Ala-D-Ala dipeptidase VanX in Streptomyces toyocaensis, Escherichia coli and Synechocystis: attributes of catalytic efficiency, stereoselectivity and regulation with implications for function; Lessard IA et al.; BACKGROUND: Vancomycin-resistant enterococci are pathogenic bacteria that have altered cell-wall peptidoglycan termini (D-alanyl-D-lactate {D-Ala-D-lactate} instead of D-alanyl-D-alanine {D-Ala-D-Ala}), which results in a 1000-fold decreased affinity for binding vancomycin . The metallodipeptidase VanX (EntVanX) is key enzyme in antibiotic resistance as it reduces the cellular pool of the D-Ala-D-Ala dipeptide . RESULTS: A bacterial genome search revealed vanX homologs in Streptomyces toyocaensis (StoVanX), Escherichia coli (EcoVanX), and Synechocystis sp . strain PCC6803 (SynVanX) . Here, the D,D-dipeptidase catalytic activity of all three VanX homologs is validated, and the catalytic efficiencies and diastereoselectivity ratios for dipeptide cleavage are reported . The ecovanX gene is shown to have an RpoS (sigma(s))-dependent promoter typical of genes turned on in stationary phase . Expression of ecovanX and an associated cluster of dipeptide permease genes permitted growth of E . coli using D-Ala-D-Ala as the sole carbon source . CONCLUSIONS: The key residues of the EntVanX active site are strongly conserved in the VanX homologs, suggesting their active-site topologies are similar . StoVanX is a highly efficient D-Ala-D-Ala dipeptidase; its gene is located in a vanHAX operon, consistent with a vancomycin-immunity function . StoVanX is a potential source for the VanX found in gram-positive enterococci . The catalytic efficiencies of D-Ala-D-Ala hydrolysis for EcoVanX and SynVanX are 25-fold lower than for EntVanX, suggesting they have a role in cell-wall turnover . Clustered with the ecovanX gene is a putative dipeptide permease system that imports D-Ala-D-Ala into the cell . The combined action of EcoVanX and the permease could permit the use of D-Ala-D-Ala as a bacterial energy source under starvation conditions.

Klin Padiatr, 1998 Jul-Aug, 210(4), 261 - 3
Vancomycin-resistant-enterococci--colonization of 24 patients on a pediatric oncology unit; Schuster F et al.; BACKGROUND: Colonization with multidrug-resistant vancomycin-resistant-enterococci (VRE) could become a serious problem, since there is no proven therapy in case of an infection or in case of transfer of glycopeptid-resistance to other organisms . PATIENTS: Description of 24 from 48 pediatric oncology patients with VRE-colonization . METHODS: Stool samples were taken from all patients of our pediatric oncology unit from March 1996 until June 1997 . Barrier isolation was introduced in May 1996, a prudent use of glycopeptid antibiotica in July 1996 . RESULTS: 193 stool sample examinations demonstrated that 24 (50%) of the 48 patients were colonized with VRE . 11 (46%) of these 24 patients were VRE-carriers at the time of their first examination; 9 (37%) patients acquired VRE during their therapy and 4 (17%) patients had come from other hospitals and already were VRE-positive when they entered our unit . In March 1997, one year after the outbreak only four patients still were VRE-positive, in June 1997 all of them were VRE-negative . The average time of colonization was 12.5 weeks . 17 (70%) of the 24 colonized patients had received glycopeptide antibiotics, 16 of them within two months before the appearance of VRE in their stool . Five colonized patients died, four of them because of their oncological illness, one because of a sepsis without proof of VRE in his blood . In the end none of our patients suffered from a VRE-infection, and besides that, the transfer of glycopeptid-resistance to other organisms was not observed . CONCLUSION: With barrier isolation and a very restrictive use of glycopeptid-antibiotica, colonization can be decreased and even stopped . Inspite of the high number of colonized patients no VRE-infectious disease occurred.

Am J Kidney Dis, 1998 Sep, 32(3), 415 - 8
Vancomycin-resistant enterococcus in end-stage renal disease; Brady JP et al.; The percentage of nosocomial vancomycin-resistant enterococci (VRE) has been increasing rapidly in the United States . This has recently resulted in recommendations to reserve vancomycin use for cases with proven resistance to other antimicrobials . We prospectively investigated the incidence of VRE in our dialysis population and compared it with a control group of 40 clinic patients with chronic renal insufficiency (CRI) who had a serum creatinine level greater than 1.5 mg/dL, but were not undergoing dialysis . The incidence of VRE on our campus is almost 10%, which is similar to US data . We studied 50 chronic hemodialysis (HD) patients and 50 peritoneal dialysis (PD) patients . Each patient had a rectal swab test performed and cultured for the presence of enterococci . Antimicrobial exposures over the 6 months before the initial swab test were reviewed in each patient . At least one repeated swab test was performed in 30 CRI, 45 HD, and 37 PD patients . From the initial swab culture, vancomycin-sensitive enterococci (VSE) were isolated in 65% of CRI, 54% of HD, and 70% of PD patients . No CRI or HD patients had VRE isolated and 2% (1 of 50) of PD patients had VRE isolated . The remaining patients had no enterococci isolated . Review of antimicrobial exposures in the 6 months before the initial swab test showed 0% of CRI, 32% of HD, and 36% of PD patients received vancomycin . Other antimicrobials were administered to 40% of CRI, 46% of HD, and 78% of PD patients in the same time period . In the month immediately preceding the initial swab test, 0% of CRI, 12% of HD, and 22% of PD patients received vancomycin and 18% of CRI, 20% of HD, and 36% of PD patients received other antimicrobials . Results from repeated cultures showed that 57% of CRI, 40% of HD, and 38% of PD patients changed their culture status related to VSE, VRE, or no enterococci present . Cultures of 342 swabs from 140 patients yielded three VRE isolates in two patients . We conclude that despite the frequent use of vancomycin and other antimicrobials, the incidence of VRE in our renal population is less than the reported incidence . Given this lack of VRE isolates, we recommend the continued judicious use of vancomycin in treating renal patients and continued enterococcal sensitivity surveillance.

J Clin Microbiol, 1998 Oct, 36(10), 2996 - 3001
Use of molecular and reference susceptibility testing methods in a multicenter evaluation of MicroScan dried overnight gram-positive MIC panels for detection of vancomycin and high-level aminoglycoside resistances in enterococci; Chen YS et al.; Modified MicroScan gram-positive MIC no . 8 panels (PM-8) were analyzed for their improved ability to detect vancomycin resistance (VR) and high-level aminoglycoside resistance (HLAR) in enterococci . A validation study design that utilized selected challenge strains, recent clinical isolates, and reproducibility experiments in a multicenter format was selected . Three independent medical centers compared the commercial panels to reference broth microdilution panels (RBM) and Synergy Quad Agar (QA) . Resistance was verified by demonstration of VR and HLAR genes by PCR tests . The study was conducted in three phases . (i) In the challenge phase (CP), two well-characterized sets of enterococci were obtained from the Centers for Disease Control and Prevention; one set contained 50 isolates for VR testing and one contained 48 isolates for HLAR testing . In addition, a set of 47 well-characterized isolates representing diverse geographic areas, obtained from earlier national surveillance studies, was tested at the University of Iowa College of Medicine (UICM) . (ii) In the efficacy phase (EP), each laboratory tested 50 recent, unique clinical isolates by all methods . (iii) In the reproducibility Phase (RP), each laboratory tested the same 10 strains by all methods in triplicate on three separate days . All isolates from the EP were sent to the UICM for molecular characterization of vanA, -B, -C1, -C2-3, and HLAR genes . In the CP, the ranking of test methods by error rates (in parentheses; very major and major errors combined, versus PCR results) were as follows: for high-level streptomycin resistance (HLSR), QA (12.0%) > PM-8 (5.2%) > RBM (1.6%); for high-level gentamicin resistance (HLGR), RBM (3.7%) > PM-8 (3.1%) > QA (2.6%); and for VR, RBM = QA (3.0%) > PM-8 (1.2%) . In the EP, agreement between all methods and the reference PCR result was 98.0% for HLSR, 99.3% for HLGR, and 98 . 6% for VR . In the RP, the percentages of results +/- 1 log2 dilution of the all-participant mode were as follows: for VR, 100% (PM-8), 98.9% (QA), and 90.0% (RBM); for HLSR, 99.6% (RBM), 98.5% (PM-8), and 82.2% (QA); and for HLGR, 99.6% (RBM), 99.3% (PM-8), and 98.1% (QA) . The ability of the PM-8 to detect VR and HLAR in enterococci was comparable to those for reference susceptibility and molecular PCR methods and was considered acceptable for routine clinical laboratory use.

Antimicrob Agents Chemother, 1998 Sep, 42(9), 2215 - 20
Glycopeptide antibiotic resistance genes in glycopeptide-producing organisms; Marshall CG et al.; The mechanism of high-level resistance to vancomycin in enterococci consists of the synthesis of peptidoglycan terminating in D-alanyl-D-lactate instead of the usual D-alanyl-D-alanine . This alternate cell wall biosynthesis pathway is ensured by the collective actions of three enzymes: VanH, VanA, and VanX . The origin of this resistance mechanism is unknown . We have cloned three genes encoding homologs of VanH, VanA, and VanX from two organisms which produce glycopeptide antibiotics: the A47934 producer Streptomyces toyocaensis NRRL 15009 and the vancomycin producer Amycolatopsis orientalis C329.2 . The predicted amino acid sequences are highly similar to those found in VRE: 54 to 61% identity for VanH, 59 to 63% identity for VanA, and 61 to 64% identity for VanX . Furthermore, the orientations of the genes, vanH, vanA, and vanX, are identical to the orientations found in vancomycin-resistant enterococci . Southern analysis of total DNA from other glycopeptide-producing organisms, A . orientalis 18098 (chloro-eremomycin producer), A . orientalis subsp . lurida (ristocetin producer), and Amycolatopsis coloradensis subsp . labeda (teicoplanin and avoparcin producer), with a probe derived from the vanH, vanA, and vanX cluster from A . orientalis C329.2 revealed cross-hybridizing DNA in all strains . In addition, the vanH, vanA, vanX cluster was amplified from all glycopeptide-producing organisms by PCR with degenerate primers complementary to conserved regions in VanH and VanX . Thus, this gene sequence is common to all glycopeptide producers tested . These results suggest that glycopeptide-producing organisms may have been the source of resistance genes in vancomycin-resistant enterococci.

J Bacteriol, 1998 Sep, 180(18), 4942 - 5
The Na+-responsive ntp operon is indispensable for homeostatis of K+ and Na+ in Enterococcus hirae at limited proton potential; Kawano M et al.; Enterococcus hirae ATCC 9790 grew well in Na+-deficient, low-K+ medium, but growth was inhibited by carbonylcyanide m-chlorophenylhydrazone (CCCP) . Growth inhibition and decrease of cellular K+ levels in the presence of CCCP were relieved by the addition of Na+ and a high concentration of K+ . In contrast, in the mutant defective in Na+-ATPase or the NtpJ component of the KtrII K+ uptake system, CCCP-induced growth inhibition was rescued by a high concentration of K+ but not of Na+ . These transporters are thus indispensable for homeostatis of K+ and Na+ at low proton potential.

Int J Syst Bacteriol, 1998 Apr, 48 Pt 2, 383 - 7
Enterococcus asini sp . nov . isolated from the caecum of donkeys (Equus asinus); de Vaux A et al.; Several Gram-positive, non-spore-forming and non-motile bacteria consisting of pairs or chains of cocci were isolated during an investigation of the bacterial flora of the caecum of donkeys . Physiological and metabolic data indicated that the strains belong to the genus Enterococcus; phenotypic traits of these organisms were not consistent with any of the currently known Enterococcus species . 16S rRNA gene sequence analysis placed these strains in the genus Enterococcus . Their closest relatives are Enterococcus avium, Enterococcus faecium and Enterococcus pseudoavium with a sequence similarity of 97.4% . This group of strains can be differentiated from the other Enterococcus spp . by their phenotypic characteristics: strains do not grow in 6.5% NaCl; they do not produce acid from mannitol, sorbitol, sorbose, sucrose, raffinose, ribose and tagatose; they produce acid from D-xylose; they are able to utilize pyruvate; and they present a negative reaction on arginine . The name Enterococcus asini sp . nov . is proposed for these strains; the type strain is AS2T (= DSM 11492T).

J Bacteriol, 1998 Sep, 180(17), 4426 - 34
Genetic linkage and cotransfer of a novel, vanB-containing transposon (Tn5382) and a low-affinity penicillin-binding protein 5 gene in a clinical vancomycin-resistant Enterococcus faecium isolate; Carias LL et al.; Mechanisms for the intercellular transfer of VanB-type vancomycin resistance determinants and for the almost universal association of these determinants with those for high-level ampicillin resistance remain poorly defined . We report the discovery of Tn5382, a ca . 27-kb putative transposon encoding VanB-type glycopeptide resistance in Enterococcus faecium . Open reading frames internal to the right end of Tn5382 and downstream of the vanXB dipeptidase gene exhibit significant homology to genes encoding the excisase and integrase of conjugative transposon Tn916 . The ends of Tn5382 are also homologous to the ends of Tn916, especially in regions bound by the integrase enzyme . PCR amplification experiments indicate that Tn5382 excises to form a circular intermediate in E . faecium . Integration of Tn5382 in the chromosome of E . faecium C68 has occurred 113 bp downstream of the stop codon for the pbp5 gene, which encodes high-level ampicillin resistance in this clinical isolate . Transfer of vancomycin, ampicillin, and tetracycline resistance from C68 to an E . faecium recipient strain occurs at low frequency in vitro and is associated with acquisition of a 130- to 160-kb segment of DNA that contains Tn5382, the pbp5 gene, and its putative repressor gene, psr . The interenterococcal transfer of this large chromosomal element appears to be the primary mechanism for vanB operon spread in northeast Ohio . These results expand the known family of Tn916-related transposons, suggest a mechanism for vanB operon entry into and dissemination among enterococci, and provide an explanation for the nearly universal association of vancomycin and high-level ampicillin resistance in clinical E . faecium strains.

Arch Ophthalmol, 1998 Aug, 116(8), 1109 - 11
Conjunctival dermoid cyst seen on examination as a chronically red eye; Martinez LM et al.; We describe a patient who was seen with a unilateral red eye and purulent discharge refractory to antibiotic treatment with multiple antibiotic regimens over the previous 4 months . Initially it was believed to be a bacterial conjunctivitis, but when conventional treatments failed it was thought to be a viral conjunctivitis with bacterial superinfection . Cultures yielded only Enterococcus . There was a small mass with a draining fistulous tract at the lateral canthus . Symptoms persisted despite courses of topical and systemic antibiotics followed by a tapering dose of steroids . The patient was taken to the operating room for an orbitotomy through the conjunctiva at the lateral canthus . Findings from pathologic examination of the excised mass demonstrated a dermoid cyst of the conjunctiva . This clinical appearance obscured the diagnosis.

Rev Esp Cardiol, 1998 Jul, 51(7), 604 - 6
{Aneurysm of the anterior mitral valve in a case of aortic endocarditis in a patient with ulcerative colitis}; Castillo Dominguez JC et al.; We report a case of an aortic endocarditis caused by Enterococcus faecium in a 34 year old patient diagnosed with ulcerative colitis . A Doppler echocardiogram showed an anterior mitral valve leaflet aneurysm, which made surgery necessary . Mitral valve leaflet aneurysm is a rare, though well-known complication of aortic valve endocarditis which can eventually perforate.

Bone Marrow Transplant, 1998 Jul, 22(2), 207 - 9
Vancomycin-resistant enterococcal infections in bone marrow transplant recipients; Koc Y et al.; Vancomycin-resistant enterococci (VRE) infections have been increasingly reported in immunosuppressed individuals over the past decade . Emergence of this pathogen in the bone marrow transplantation (BMT) setting, in the form of bacteremia or positive stool cultures, is of concern because of lack of effective antimicrobial therapy . We report episodes of vancomycin-resistant E . faecium bacteremia in two patients undergoing BMT including the first case of VRE meningitis observed in this setting . Since the outcome in these patients undergoing matched unrelated donor BMT was fatal, we believe that routine screening for VRE in high risk patients should be considered . Management of VRE carrier state in BMT candidates is unclear at present.

Infect Control Hosp Epidemiol, 1998 Jul, 19(7), 515 - 8
Environmental contamination with vancomycin-resistant enterococci in an outpatient setting; Smith TL et al.; Eleven cancer patients colonized with vancomycin-resistant enterococci (VRE) were followed as outpatients . Environmental cultures were obtained from clinic rooms before and after patients care . Environmental contamination occurred in 29% of encounters . Superficial disinfection did not eradicate contamination, although more thorough cleaning did . We conclude that environmental VRE contamination occurs in the outpatient setting . Infection control practices, similar to those used in the inpatient setting, may be necessary for outpatient clinics.

Mol Cell, 1998 Jul, 2(1), 75 - 84
The structure of VanX reveals a novel amino-dipeptidase involved in mediating transposon-based vancomycin resistance; Bussiere DE et al.; VanX is a zinc-dependent D-alanyl-D-alanine dipeptidase that is a critical component in a system that mediates transposon-based vancomycin resistance in enterococci . It is also a key drug target in circumventing clinical vancomycin resistance . The structure of VanX from E . faecium has been solved by X-ray crystallography and reveals a Zn(2+)-dipeptidase with a unique overall fold and a well-defined active site confined within a cavity of limited size . The crystal structures of VanX, the VanX:D-alanyl-D-alanine complex, the VanX:D-alanine complex, and VanX in complex with phosphonate and phosphinate transition-state analog inhibitors, are also presented at high resolution . Structural homology searches of known structures revealed that the fold of VanX is similar to those of two proteins: the N-terminal fragment of murine Sonic hedgehog and the Zn(2+)-dependent N-acyl-D-alanyl-D-alanine carboxypeptidase of S . albus G.

Acta Clin Belg, 1998 Jun, 53(3), 168 - 77
Anti-infective strategies in neutropenic patients; Maertens J et al.; In spite of considerable progress in clinical care and supportive measures, infection remains by far the principal cause of morbidity and mortality in febrile neutropenic patients, especially following intensive myelosuppressive therapy for haematological malignancies . The concept of empirical therapy, dating from the early 1970s and referring to the use of broad-spectrum antibiotics without or before definite proof of infection, was of paramount importance for the elimination of early infectious deaths, mainly due to Gram-negative bacteria, and has dramatically reduced mortality figures by infection to about 6% . However over the last two decades, consecutive trials have witnessed marked shifts, both in the spectrum of offending pathogens, bacterial as well as non-bacterial, and in the clinical presentations . Although most clinical studies completed by international groups have advocated the use of combination therapy on theoretical grounds, including a beta-lactam plus an aminoglycoside or double beta-lactam no single recent trial comparing monotherapy with the newer extended-spectrum compounds versus combination therapy could demonstrate relevant differences in outcome . Contrary, combinations were hampered by associated toxicity . We currently accept monotherapy with agents such as carbapenems and third-generation cephalosporins (ceftazidime) as standard of empirical care in neutropenic patients while the results of ongoing trials with fourth-generation cephalosporins and fluoroquinolones are awaited with impatience . However, the universally adopted and indiscriminate implementation of broadspectrum therapy has undoubtedly taken a toll of current anti-infective strategies, including the emergence of highly resistant isolates and the disastrous shift towards invasive mould and yeast infections . Consequently, empirical therapy has evolved towards a planned-progressive modification in persistent neutropenic febricity, especially aiming at early antifungal coverage . However, randomised data on second-and third-line modifications of empirical regimens are sparse; moreover, significant divergence exists between European and North-American centres . The exact place and need for glycopeptide antibiotics remains another controversial issue, certainly, in view of the alarming isolation of resistant enterococci . The improved identification of patient subgroups by the development of accurate risk assessment models based on prognostic factors, such as age, underlying disorder, duration of neutropenia, intensity of treatment and offending pathogen, should result in a more rational application of antimicrobial agents and may pave the way to a patient-tailored (rather than a planned-progressive) and modifiable anti-infective approach with respect to hospitalisation and need for extended-spectrum empirical therapy.

J Food Prot, 1998 Jul, 61(7), 833 - 8
Bacteriocidal activity of sanitizers against Enterococcus faecium attached to stainless steel as determined by plate count and impedance methods; Andrade NJ et al.; Enterococcus faecium attached to stainless steel chips (100 mm2) was treated with the following sanitizers: sodium hypochlorite, peracetic acid (PA), peracetic acid plus an organic acid (PAS), quaternary ammonium, organic acid, and anionic acid . The effectiveness of sanitizer solutions on planktonic cells (not attached) was evaluated by the Association of Official Analytical Chemists (AOAC) suspension test . The number of attached cells was determined by impedance measurement and plate count method after vortexing . The decimal reduction (DR) in numbers of the E . faecium population was determined for the three methods and was analyzed by analysis of variance (P < 0.05) using Statview software . The adhered cells were more resistant (P < 0.05) than nonadherent cells . The DR averages for all of the sanitizers for 30 s of exposure were 6.4, 2.2, and 2.5 for the AOAC suspension test, plate count method after vortexing, and impedance measurement, respectively . Plate count and impedance methods showed a difference (P < 0.05) after 30 s of sanitizer exposure but not after 2 min . The impedance measurement was the best method to measure adherent cells . Impedance measurement required the development of a quadratic regression . The equation developed from 82 samples is as follows: log CFU/chip = 0.2385T2-0.96T + 9.35, r2 = 0.92, P < 0.05, T = impedance detection time in hours . This method showed that the sanitizers PAS and PA were more effective against E . faecium than the other sanitizers . At 30 s, the impedance method recovered about 25 times more cells than the plate count method after vortexing . These data suggest that impedance measurement is the method of choice when evaluating the number of bacterial cells adhered to a surface.

Drugs Exp Clin Res, 1998, 24(2), 73 - 6
Effect of quinupristin/dalfopristin alone or in combination with vancomycin on the structure of Enterococcus faecium; Lorian V et al.; Twenty strains of Enterococcus faecium susceptible to quinupristin/dalfopristin (< 2 mg/l) were DNA fingerprinted to exclude strain duplication . Ten strains were susceptible to vancomycin (minimal inhibitory concentration {MIC} < 2 mg/l) and 10 were resistant to vancomycin (MIC > 400 mg/l) . Vancomycin at 1/2 MIC, quinupristin/dalfopristin at 1/4 MIC and their combination, except for a tube control, was added to 10 ml trypticase soy broth tubes which were planted with the respective 24-h trypticase soy broth cultures . The products of incubation were sampled periodically throughout 24 h for gram stain and electron microscopy . Cell size was measured on photographs at 20,000x final magnification and results were statistically analyzed . The cells of all strains of Enterococcus faecium exposed for 12 h to quinupristin/dalfopristin were comparable in size to the control, Most cells, however, showed areas of low density of ribosome in the center of the cells . The cells of Enterococcus faecium resistant to vancomycin exposed to vancomycin were larger than the controls with means of 1.96 micron -2.07 micron versus 1.16 micron (p < 0.001); these cells consisted of individual organisms connected by wide cross walls of abnormal fibrous structure . Enterococcus faecium sensitive to vancomycin exposed to vancomycin remained comparable to the control . The combination of quinupristin/dalfopristin plus vancomycin produced large cells with multiple abnormal cross walls in both vancomycin-resistant and vancomycin-sensitive Enterococcus faecium . The addition of quinupristin/dalfopristin to vancomycin appears to modify the vancomycin-susceptible strains to respond to vancomycin in the same manner as do the vancomycin-resistant organisms.

J Clin Microbiol, 1998 Aug, 36(8), 2333 - 5
Screening of stool samples for identification of vancomycin-resistant Enterococcus isolates should include the methyl-alpha-D-glucopyranoside test to differentiate nonmotile Enterococcus gallinarum from E . faecium; Turenne CY et al.; The methyl-alpha-D-glucopyranoside (MDG) test has been shown to be superior to motility testing in differentiating Enterococcus faecium from E . gallinarum . In the present study, 33 vancomycin-resistant enterococcus (VRE) isolates collected as part of a stool surveillance study were compared by using motility and MDG . Motility testing identified all 33 isolates as E . faecium, whereas MDG identified 11 of the 33 isolates as nonmotile E . gallinarum . The MDG results were confirmed by sequencing the 16S rDNA V6-to-V8 region . We conclude that the MDG test is a necessary component of routine VRE screening.

J Clin Microbiol, 1998 Aug, 36(8), 2294 - 7
Detection and differentiation of vanC-1, vanC-2, and vanC-3 glycopeptide resistance genes in enterococci; Clark NC et al.; The VanC phenotype, as found in Enterococcus gallinarum, E . casseliflavus, and E . flavescens, is characterized by intrinsic low-level resistance to vancomycin . The nucleotide sequences of the vanC-1 gene in E . gallinarum, the vanC-2 gene in E . casseliflavus, and the vanC-3 gene in E . flavescens have been reported, although there is some disagreement as to whether E . flavescens is a legitimate enterococcal species . Previous attempts to differentiate the vanC-2 and vanC-3 genes by PCR analysis have been unsuccessful . The purpose of the present study was to detect and differentiate the three vanC determinants and examine the distribution of these genes in a collection of both typical and atypical enterococci . The 796-bp vanC-1 PCR product was amplified only from E . gallinarum isolates . As expected, due to the extensive homology in the vanC-2 and vanC-3 gene sequences, all of the E . casseliflavus and E . casseliflavus/flavescens isolates produced the 484-bp vanC-2 PCR product, although the E . gallinarum isolates were negative . Only the E . casseliflavus/flavescens isolates produced the 224-bp vanC-3 product . Using the three sets of primers, we were able to detect and distinguish the vanC-1, vanC-2, and vanC-3 genes from both typical and atypical enterococci strains . Antimicrobial susceptibility tests and analysis of genomic DNA by pulsed-field gel electrophoresis were also performed, but the results indicated that they were not able to distinguish among strains possessing the three vanC genotypes.

Rev Esp Cardiol, 1998, 51 Suppl 2, 51 - 7
{Drug treatment of native valve infective endocarditis in patients not addicted to parenteral drugs}; Llinares Mondejar P et al.; Infectious endocarditis is an infection that is characterized by the presence of microorganisms in dense populations in vegetating lesions in the endocardium . Because phagocyte penetration to the interior of the vegetation is practically impossible, to cure infectious endocarditis, high doses of bactericidal antibiotics are administered, usually intravenously and for a long duration . In this article, antibiotic treatment is reviewed, depending on the isolated microorganism and in cases where necessary, treatment is initiated in an empirical manner . Once the microorganism was isolated, the recommended guidelines for antibiotic treatment have gone through some variations in recent years, due to the changing pattern of antibiotic sensitivity of some microorganisms, to the point of finding ourselves on occasion without an effective treatment (e.g . multiresistant enterococci) . In addition, these variations are due to the introduction of new antibiotics that allow, in special cases, for the treatment to be administered on an outpatient basis . Using anticoagulation in infectious endocarditis is still considered controversial . In general, only patients having cardiac valvular prostheses seem to benefit from its use.

J Infect Dis, 1998 Jul, 178(1), 159 - 63
Penicillin-binding protein 5 sequence alterations in clinical isolates of Enterococcus faecium with different levels of beta-lactam resistance; Rybkine T et al.; The low-affinity penicillin-binding protein (PBP) 5 is the main beta-lactam target and is responsible for resistance to this class of antibiotics in Enterococcus faecium . The PBP 5 variants of 15 clinical isolates (including 8 resistant to vancomycin) with different levels of beta-lactam resistance were analyzed . Most of the highly beta-lactam-resistant isolates produced small quantities of PBP 5 of low affinity . This was associated with particular amino acid substitutions: an Ala or Ile for Thr-499, a Glu for Val-629, and a Pro for Ser-667 . A change of Met-485 to Thr or Ala (adjacent to the conserved SDN box) was observed in isolates with MICs of ampicillin of 64 or 128 microg/mL, respectively . In the 2 most resistant isolates, with MICs of ampicillin of 256 microg/mL, an additional Ser was present just after Ser-466 . Thus, particular point mutations in PBP 5 and combinations thereof may lead to high-level beta-lactam resistance in E . faecium.

J Clin Microbiol, 1998 Jul, 36(7), 2105 - 8
Genetic analysis of multiple vancomycin-resistant Enterococcus isolates obtained serially from two long-term-care patients; Schoonmaker DJ et al.; Fifty-eight vancomycin-resistant enterococcal isolates were obtained from two patients over 9 weeks . Numerous pulsed-field gel electrophoresis fingerprinting types were isolated from each patient . By PCR, all isolates were vanA+ . However, many isolates from patient B were found to lack vanA by hybridization . Our results demonstrate the importance of examining multiple isolates, especially from patients who are at high risk of infection.

J Clin Microbiol, 1998 Jul, 36(7), 1927 - 32
Molecular characterization of vancomycin-resistant enterococci from hospitalized patients and poultry products in The Netherlands; van den Braak N et al.; Vancomycin-resistant enterococci (VRE) pose an emerging health risk, but little is known about the precise epidemiology of the genes coding for vancomycin resistance . To determine whether the bacterial flora of consumer poultry serves as a gene reservoir, the level of contamination of poultry products with VRE was determined . VRE were genotyped by pulsed-field gel electrophoresis (PFGE), and transposon structure mapping was done by PCR . The vanX-vanY intergenic regions of several strains were further analyzed by sequencing . A total of 242 of 305 (79%) poultry products were found to be contaminated with VRE . Of these VRE, 142 (59%) were high-level-vancomycin-resistant Enterococcus faecium strains (VREF) . PFGE revealed extensive VREF heterogeneity . Two genotypes were found nationwide on multiple occasions: type A (22 of 142 VREF {15%}) and type B (14 of 142 VREF {10%}) . No PFGE-deduced genetic overlap was found when VREF from humans were compared with VREF from poultry . Two vanA transposon types were identified among poultry strains . In 59 of 142 (42%) of the poultry VREF, the size of the intergenic region between vanX and vanY was approximately 1,300 bp . This transposon type was not found in human VREF . In contrast, all human strains and 83 of 142 (58%) of the poultry VREF contained an intergenic region 543 bp in size . Sequencing of this 543-bp intergenic vanX-vanY region demonstrated full sequence conservation . Though preliminary, these data suggest that dissemination of the resistance genes carried on transposable elements may be of greater importance than clonal dissemination of resistant strains . This observation is important for developing strategies to control the spread of glycopeptide resistance.

Langenbecks Arch Surg, 1998 Mar, 383(1), 35 - 43
Management of abdominal sepsis; Berger D et al.; INTRODUCTION: Today the management of the different forms of peritonitis is generally standardised . The classification of primary and secondary peritonitis is well accepted . From a pathophysiological point of view, postoperative and post-traumatic peritonitis should be considered as independent entities . The bacteriological isolates from the inflamed peritoneal cavity do not correlate with the clinical course, and the occurrence of enterococci and bacteroides may be slightly related to ongoing infectious complications . CLASSIFICATION: Valuable scoring systems mainly rely on systemic signs of the septic disease and seem to better differentiate the prognosis of the disease than more surgically oriented scores do . Although the scoring systems did not allow any clinical decision, they should be used to help better compare patients treated in different institutions . The observation of the minor relevance of bacteriology and the superiority of general sepsis scores agrees with the fact that pre-existing septic organ dysfunction and pre-existing comorbidity are the main determinants of mortality . TREATMENT: Surgical therapy focuses on the control of the source of infection because it has been clearly shown that, without resolving the source of infection, the prognosis remains poor . Adjuvant surgical measures aim at the further reduction of the bacterial load in the peritoneal cavity . Planned relaparotomy, relaparotomy on demand, and continuous closed peritoneal lavage are used . RESULTS: Clinical results proved these methods to be equally effective although pathophysiological considerations favour closed peritoneal lavage . CONCLUSION: Summarising the available data, we need a more sophisticated understanding of the pathophysiology of the peritonitis, and well-designed clinical studies are necessary to define the optimal surgical treatment modalities.

Transplantation, 1998 May 27, 65(10), 1397 - 8
Interaction between tacrolimus and chloramphenicol in a renal transplant recipient; Schulman SL et al.; BACKGROUND: The metabolism of tacrolimus is influenced by several medications when they are given concurrently . We report the interaction between tacrolimus and chloramphenicol in a renal transplant recipient . METHODS: An adolescent with vancomycin-resistant Enterococcus was given standard doses of chloramphenicol . Tacrolimus trough levels increased, and the dose was adjusted to maintain the target trough level . Pharmacokinetic studies were obtained during chloramphenicol administration and 14 days after its discontinuation . RESULTS: Toxic levels of tacrolimus were seen on the second day of chloramphenicol administration, requiring an 83% reduction in the tacrolimus dose . The dose-adjusted area under the curve value for tacrolimus was 7.5-fold greater while the patient was on chloramphenicol . These data are consistent with inhibition of tacrolimus clearance by chloramphenicol CONCLUSIONS: Chloramphenicol interferes with tacrolimus metabolism . Careful monitoring of tacrolimus trough levels during concomitant chloramphenicol therapy is recommended to avoid toxicity.

J Hosp Infect, 1998 May, 39(1), 13 - 8
Selective isolation of vancomycin-resistant enterococci; Nelson RR; Many laboratories are likely to be or to become involved in screening patients for the carriage of vancomycin-resistant enterococci (VRE) . A choice has to be made from the numerous formulations described and decisions made on the degree of vancomycin supplementation and the need for an enrichment phase . Few comparative trials and little critical evaluation has been performed to date and there is as yet no clear choice as to the optimal formulation . Laboratories must choose the formulation that most suits their particular requirements and circumstances.

Cell Mol Life Sci, 1998 Apr, 54(4), 325 - 31
Control of peptidoglycan synthesis in vancomycin-resistant enterococci: D,D-peptidases and D,D-carboxypeptidases; Reynolds PE; Resistance to glycopeptide antibiotics in enterococci results from the synthesis of peptidoglycan precursors with low affinity for these antibiotics . The resistance proteins are encoded on transposons in VanA and VanB type enterococci and are involved in regulation, synthesis of new resistant precursors and elimination of wild-type sensitive precursors by hydrolysis of D-alanyl-D-alanine (D,D-peptidase activity encoded by vanX) and removal of D-alanine from UDP-N-acetylmuramyl (UDP-MurNAc)-pentapeptide (D,D-carboxypept-idase activity encoded by vanY) . The substrate specificities of VanX and VanY ensure that essentially only precursors with low affinity for glycopeptide antibiotics are available for peptidoglycan synthesis in strains induced to resistance.

Arch Intern Med, 1998 May 25, 158(10), 1127 - 32
The role of "colonization pressure" in the spread of vancomycin-resistant enterococci: an important infection control variable; Bonten MJ et al.; OBJECTIVE: The spread of nosocomial multiresistant microorganisms is affected by compliance with infection control measures and antibiotic use . We hypothesized that "colonization pressure" (ie, the proportion of other patients colonized) also is an important variable . We studied the effect of colonization pressure, compliance with infection control measures, antibiotic use, and other previously identified risk factors on acquisition of colonization with vancomycin-resistant enterococci (VRE) . METHODS: Rectal colonization was studied daily for 19 weeks in 181 consecutive patients who were admitted to a single medical intensive care unit . A statistical model was created using a Cox proportional hazards regression model including length of stay in the medical intensive care unit until acquisition of VRE, colonization pressure, personnel compliance with infection control measures (hand washing and glove use), APACHE (Acute Physiology and Chronic Health Evaluation) 11 scores, and the proportion of days that a patient received vancomycin or third-generation cephalosporins, sucralfate, and enteral feeding . RESULTS: With survival until colonization with VRE as the end point, colonization pressure was the most important variable affecting acquisition of VRE (hazard ratio {HR}, 1.032; 95% confidence interval {C1}, 1.012-1.052; P=.002) . In addition, enteral feeding was associated with acquisition of VRE (HR, 1.009; 95% CI, 1.000-1.017; P=.05), and there was a trend toward association of third-generation cephalosporin use with acquisition (HR, 1.007; 95% CI, 0.999-1.015; P=.11) . The effects of enteral feeding and third-generation cephalosporin use were more important when colonization pressure was less than 50% . Once colonization pressure was 50% or higher, these other variables hardly affected acquisition of VRE . CONCLUSIONS: Acquisition of VRE was affected by colonization pressure, the use of antibiotics, and the use of enteral feeding . However, once colonization pressure was high, it became the major variable affecting acquisition of VRE.

Protein Sci, 1998 May, 7(5), 1147 - 55
A thioredoxin fusion protein of VanH, a D-lactate dehydrogenase from Enterococcus faecium: cloning, expression, purification, kinetic analysis, and crystallization; Stoll VS et al.; The gene encoding the vancomycin resistance protein VanH from Enterococcus faecium, a D-lactate dehydrogenase, has been cloned into a thioredoxin expression system (pTRxFus) and expressed as a fusion protein . The use of several other expression systems yielded only inclusion bodies from which no functional protein could be recovered . Experiments to remove the thioredoxin moiety by enterokinase cleavage at the engineered recognition site under a variety of conditions resulted in nonspecific proteolysis and inactivation of the protein . The intact fusion protein was, therefore, used for kinetic studies and crystallization trials . It has been purified to greater than 90% homogeneity by ammonium sulfate precipitation followed by phenyl Sepharose chromatography . Based on k(cat)/KM for pyruvate, it is 20% as active as native VanH . Michaelis constants for NADPH, NADH, and pyruvate, of approximately 3.5 microM, 19.0 microM, and 1.5 mM, respectively, were comparable to those reported for the native VanH (Bugg TDH et al., 1991, Biochemistry 30:10408-10415) . Like native VanH, maximum activity of the fusion protein requires the presence of an anion (phosphate or acetate), however, in addition, a strongly reducing environment is needed for optimal efficacy . Competitive inhibition constants for ADP-ribose, NAD+, and oxamate have also been determined . Crystallization by hanging drop vapor diffusion produced two different crystal forms, one hexagonal and the other tetragonal . Flash-frozen crystals of the tetragonal form diffracted to 3.0 A resolution at a synchrotron radiation source.

Infect Control Hosp Epidemiol, 1998 Apr, 19(4), 261 - 4
Disinfection of hospital rooms contaminated with vancomycin-resistant Enterococcus faecium; Byers KE et al.; Sixteen percent of hospital room surfaces remained colonized by vancomycin-resistant enterococci (VRE) after routine terminal disinfection . Disinfection with a new "bucket method" resulted in uniformly negative cultures . Conventional cleaning took an average of 2.8 disinfections to eradicate VRE from a hospital room, while only one cleaning was required with the bucket method.

Ceska Gynekol, 1997 Aug, 62(4), 204 - 12
{Antibiotic prophylaxis of infectious complications in gynecologic surgery}; Zivny J et al.; Infections are still the most frequent postoperative complications and one of the limiting factors of successful gynaecological surgery . In recent years information on successful anti-microbial chemoprophylaxis is increasing and is associated with reduced postoperative inflammations, febrile morbidity and early complications . Views differ above all as regards indications for the use of antibiotic prophylaxis and the selection of a suitable antibiotic . Data in the literature differ also as regards achieved results . The submitted work had the objective to test on a representative group the success and rationality of medicamentous prophylaxis in gynaecological surgery and to contribute to a clearer view on controversial points . 203 women admitted to the Second Gynaecological and Obstetric Department of the First Medical Faculty Charles University and General Faculty Hospital Prague for elective abdominal or vaginal hysterectomy on account of a benign indication were divided into three groups which did not differ from the demographic or medical aspect . In group A (53 women) for prophylaxis two doses of Augmentin were used (combination of amoxycillin with clavulanic acid) i.v., patients in group M (50 women) had three doses of Mandol (Cefamandol) i.m., and in control group K (100 patients) no antibiotics were administered prophylactically . The authors investigated the postoperative course and evaluated some parameters in relation to possible postoperative infectious complications . The results proved unequivocally that prophylaxis with Augmentin reduces significantly the postoperative infectious morbidity (11.5%), febrile morbidity (5.6%) and the incidence of early infectious complications (3.8%) after abdominal or vaginal hysterectomy, as compared with the control group (35%, 31% and 11% resp.) . Prophylaxis with Cefamandol reduced only in few parameters postoperative complications, but in general did not lead to a significant improvement of the postoperative course nor to a reduction of postoperative inflammatory complications . Similar results were obtained when only complications after abdominal hysterectomy were evaluated . The results of bacteriological examination confirmed the expected differences in the spectrum of efficacy of the two antibiotics on the most common microbial flora in the given area, i.e . a high sensitivity of Augmention to enterococci and bacterioids and resistance of these bacteria to Mandol . These results can be considered one of the reasons of different results of the two antibiotics . Prophylaxis with amoxycillin/clavulanic acid was found to be safe, very effective and financially feasible prevention of postoperative infectious complications after abdominal and vaginal hysterectomy . It led to a significant increase in the number of cases without any complications, when compared with the control group.

Clin Infect Dis, 1998 May, 26(5), 1200 - 3
Epidemiology, appropriateness, and cost of vancomycin use; Jarvis WR; Pharmaceutical costs, which approach $40 billion annually, account for about 8% of health care costs . Prescription drugs represent 5% to 20% of the total hospital budget, and antimicrobials account for 20% to 50% of hospital pharmaceutical costs . At one university hospital, the percentage of patients receiving antimicrobials increased from 31.8% in 1988 to 53.1% in 1994 . Receipt of vancomycin has been associated with the emergence of resistant enterococci and has resulted in Centers for Disease Control and Prevention (CDC) recommendations for its use . Studies show that vancomycin use is increasing, that dosing is often inappropriate, that certain populations (such as oncology, neurosurgery, and cardiovascular surgery patients) are more likely to receive vancomycin, and that often use is not consistent with CDC recommendations . Few studies have assessed the cost of vancomycin use; those that have show that it is costly . Further studies of vancomycin use are needed, so that use can be improved through focused educational programs.

Clin Infect Dis, 1998 May, 26(5), 1127 - 33
Vancomycin-resistant and vancomycin-susceptible enterococcal bacteremia: comparison of clinical features and outcomes; Lucas GM et al.; Vancomycin-resistant Enterococcus (VRE) is a major nosocomial pathogen . We collected clinical and laboratory data on 93 hospitalized adults with VRE bacteremia and 101 adults with vancomycin-susceptible enterococcal (VSE) bacteremia . Risk factors for VRE bacteremia included central venous catheterization, hyperalimentation, and prolonged hospitalization prior to the initial blood culture . VRE-infected patients were less likely to have undergone recent surgery or have polymicrobial bacteremia, suggesting a pathogenesis distinct from traditional VSE bacteremia . Prior exposure to metronidazole was the only significant pharmacologic risk factor for VRE bacteremia . Animal studies suggest metronidazole potentiates enterococcal overgrowth in the gastrointestinal tract and translocation into the bloodstream . An increasing APACHE II score was the major risk factor for death in a multivariate analysis, with VRE status being of only borderline significance.

Chem Biol, 1998 Apr, 5(4), 197 - 207
Active-site mutants of the VanC2 D-alanyl-D-serine ligase, characteristic of one vancomycin-resistant bacterial phenotype, revert towards wild-type D-alanyl-D-alanine ligases; Healy VL et al.; BACKGROUND: The rising number of vancomycin-resistant enterococci (VREs) is a major concern to modern medicine because vancomycin is currently the 'last resort' drug for life-threatening infections . The D-alanyl-D-X ligases (where X is an hydroxy or amino acid) of bacteria catalyze a critical step in bacterial cell-wall peptidoglycan assembly . In bacteria that produce glycopeptide antibiotics and in opportunistic pathogens, including VREs, D-, D-ligases serve as switches that confer antibiotic resistance on the bacteria themselves . Peptidoglycans in vancomycin-sensitive bacteria end in D-alanyl-D-alanine, whereas in vancomycin-resistant bacteria they end in D-alanyl-D-lactate or D-alanyl-D-serine . RESULTS: We demonstrate that the selective utilization of D-serine by the Enterococcus casseliflavus VanC2 ligase can be altered by mutagenesis of one of two residues identified by homology to the X-ray structure of the Escherichia coli D-alanyl-Dalanine ligase (DdlB) . The Arg322-->Met (R322M) and Phe250-->Tyr (F250Y) ligase mutants show a 36-44-fold decrease in the use of D-serine, as well as broadened specificity for utilization of other D-amino acids in place of D-serine . The F250Y R322M double mutant is effectively disabled as a D-alanyl-D-serine ligase and retains 10% of the catalytic activity of wild-type D-alanyl-D-alanine ligases, reflecting a 6,000-fold switch to the D-alanyl-D-alanine peptide . Correspondingly, the Leu282-->Arg mutant of the wild-type E . coli DdlB produced a 560-fold switch towards D-alanyl-D-serine formation . CONCLUSIONS: Single-residue changes in the active-site regions of D-, D-ligases can cause substantial changes in recognition and activation of hydroxy or amino acids that have consequences for glycopeptide antibiotic efficacy . The observations reported here should provide an approach for combatting antibiotic-resistant bacteria.

Antimicrob Agents Chemother, 1998 May, 42(5), 1088 - 92
Characterization of vancomycin-resistant Enterococcus faecium isolates from the United States and their susceptibility in vitro to dalfopristin-quinupristin; Eliopoulos GM et al.; In the course of clinical studies with the investigational streptogramin antimicrobial dalfopristin-quinupristin, isolates of vancomycin-resistant Enterococcus faecium were referred to our laboratory from across the United States . Seventy-two percent of the strains were of the VanA type, phenotypically and genotypically, while 28% were of the VanB type . High-level resistance to streptomycin or gentamicin was observed in 86 and 81%, respectively, of the VanA strains but in only 69 and 66%, respectively, of the VanB strains . These enterococci were resistant to ampicillin (MIC for 50% of the isolates tested {MIC50} and MIC90, 128 and 256 microg/ml, respectively) and to the other approved agents tested, with the exception of chloramphenicol (MIC90, 8 microg/ml) and novobiocin (MIC90, 1 microg/ml) . Considering all of the isolates submitted, dalfopristin-quinupristin inhibited 86.4% of them at concentrations of < or = 1 microg/ml and 95.1% of them at < or = 2 microg/ml . However, for the data set comprised of only the first isolate submitted for each patient, 94.3% of the strains were inhibited at concentrations of < or = 1 microg/ml and 98.9% were inhibited at concentrations of < or = 2 microg/ml . Multiple drug resistance was very common among these isolates of vancomycin-resistant E . faecium, while dalfopristin-quinupristin inhibited the majority at concentrations that are likely to be clinically relevant.

Antimicrob Agents Chemother, 1998 May, 42(5), 1229 - 32
A new high-level gentamicin resistance gene, aph(2'')-Id, in Enterococcus spp; Tsai SF et al.; Enterococcus casseliflavus UC73 is a clinical blood isolate with high-level resistance to gentamicin . DNA preparations from UC73 failed to hybridize with intragenic probes for aac(6')-Ie-aph(2'')-Ia and aph(2'')-Ic . A 4-kb fragment from UC73 was cloned and found to confer resistance to gentamicin in Escherichia coli DH5alpha transformants . Nucleotide sequence analysis revealed the presence of a 906-bp open reading frame whose deduced amino acid sequence had a region with homology to the aminoglycoside-modifying enzyme APH(2'')-Ic and to the C-terminal domain of the bifunctional enzyme AAC(6')-APH(2'') . The gene is designated aph(2'')-Id, and its observed phosphotransferase activity is designated APH(2'')-Id . A PCR-generated intragenic probe hybridized to the genomic DNA from 17 of 118 enterococcal clinical isolates (108 with high-level gentamicin resistance) from five hospitals . All 17 were vancomycin-resistant Enterococcus faecium isolates, and pulsed-field typing revealed three distinct clones . The combination of ampicillin plus either amikacin or neomycin exhibited synergistic killing against E . casseliflavus UC73 . Screening and interpretation of high-level aminoglycoside resistance in enterococci may need to be modified to include detection of APH(2'')-Id.

New Microbiol, 1998 Apr, 21(2), 113 - 22
Molecular epidemiology by ribotyping and PCR-ribotyping of Enterococcus faecium strains isolated from intercontinental areas; Sechi LA et al.; In this study classical ribotyping based on hybridization of an enteroccocal ribosomal operon previously cloned from Enterococcus hirae (Sechi and Daneo-Moore, 1993) with XbaI cut chromosomal DNA and PCR-ribotyping were used to characterize the molecular epidemiology of 131 Enterococcus faecium, with high-level resistance to gentamicin, isolated from different hospitals in Italy and the United States . The ribotyping was able to differentiate all 131 clinical isolates into 96 family patterns . These family patterns appeared to be useful in establishing epidemiological spread . The results obtained were in agreement with those previously published, suggesting the presence of five to six operons in the Enterococcus genus (Sechi et al., 1994) . We performed PCR-ribotyping, based on conserved sequences at the 3' end of the enterococcal 16S rrn and the 5' end of the 23S rrn, on 131 clinical isolates as well as on several enterococcal ATCC strains tested . The results were then compared with those obtained with the classical ribotyping method . The results suggest the presence of at least four classes of intergenic spacers among enterococci, but these classes are not helpful in differentiating between Enterococci or among Enterococcal isolates.

Am J Gastroenterol, 1998 Apr, 93(4), 636 - 9
Enterococcal bacteremia after transjugular intrahepatic portosystemic shunts (TIPS); Brown RS Jr et al.; The objective of this study was to analyze a series of patients with Enterococcus faecium infection following transjugular intrahepatic portosystemic shunts (TIPS) in order to define the risk factors, outcome, and role of treatment including hepatic transplantation . This study is a case series from a tertiary referral center for liver transplantation . The medical records of four patients referred to one teaching hospital in San Francisco between 1990 and 1995 for evaluation or management of Enterococcal infection following TIPS were reviewed . A review of the microbiology records of all 314 patients who underwent TIPS at that institution and a MEDLINE search were performed to assess whether any other cases existed . The effect of therapy on survival was assessed, in particular, the repeated use of TIPS and prolonged courses of antibiotics . All four patients had thrombosis of their TIPS at the time of diagnosis of enterococcal bacteremia . All were treated with prolonged courses of intravenous antibiotics . One patient had echocardiographic evidence of subacute bacterial endocarditis with chronic aortic insufficiency . In all cases, liver transplantation was contraindicated in the acute setting because of uncontrolled endovascular infection . Two of four patients survived; these were the only two patients who had had a successful repeat TIPS . Enterococcal bacteremia is a rare complication following TIPS but carries a high mortality . It usually occurs in the setting of technically difficult TIPS with shunt thrombosis . Management should be focused on long term antibiotics and attempts at reestablishment of portal decompression with another TIPS . Liver transplantation should not be considered until the infection is cleared . Prophylaxis for Enterococcus species should be considered in technically difficult or unsuccessful TIPS.

Appl Environ Microbiol, 1998 May, 64(5), 1825 - 30
Antibiotic resistance patterns of enterococci and occurrence of vancomycin-resistant enterococci in raw minced beef and pork in Germany; Klein G et al.; The food chain, especially raw minced meat, is thought to be responsible for an increase in the incidence of vancomycin-resistant enterococci (VRE) in human nosocomial infections . Therefore, 555 samples from 115 batches of minced beef and pork from a European Union-licensed meat-processing plant were screened for the occurrence of VRE . The processed meat came from 45 different slaughterhouses in Germany . Enterococci were isolated directly from Enterococcosel selective agar plates and also from Enterococcosel selective agar plates supplemented with 32 mg of vancomycin per liter . In addition, peptone broth was used in a preenrichment procedure, and samples were subsequently plated onto Enterococcosel agar containing vancomycin . To determine resistance, 209 isolates from 275 samples were tested with the glycopeptides vancomycin, teicoplanin, and avoparcin and 19 other antimicrobial substances by using a broth microdilution test . When the direct method was used, VRE were found in 3 of 555 samples (0.5%) at a concentration of 1.0 log CFU/g of minced meat . When the preenrichment procedure was used, 8% of the samples were VRE positive . Our findings indicate that there is a low incidence of VRE in minced meat in Germany . In addition, the resistance patterns of the VRE isolates obtained were different from the resistance patterns of clinical isolates . A connection between the occurrence of VRE in minced meat and nosocomial infections could not be demonstrated on the basis of our findings.

Tidsskr Nor Laegeforen, 1998 Mar 20, 118(8), 1188 - 90
{First infection with vancomycin resistant type VanA enterococci in a Norwegian hospital}; Haarr E et al.; Enterococci are part of the normal human and animal bowel flora . They are considered bacteria of relatively low virulence, but are important nosocomial pathogens . In the context of their intrinsic resistance to a number of antimicrobial agents, the rapid emergence of multiresistant enterococci is alarming . As inhabitants of the gastrointestinal tract, they come into close contact with other bacteria and may pass antibiotic resistance genes to them . We report the first case of infection with a VanA vancomycin-resistant . Enterococcus in Norway . The strain was identified as Enterococcus faccium with high level resistance to aminoglycosides, ampicillin, teicoplanin and vancomycin . The VanA phenotype was confirmed by PCR detection of the vanA gene . Transmission, treatment, prevention, and control of infections with vancomycin-resistant enterococci is discussed.

Dig Dis, 1998 Jan-Feb, 16(1), 47 - 60
Antimicrobial treatment of intra-abdominal infections; Elsakr R et al.; There have been several recent changes that influence the management of intra-abdominal infections . These changes include important developments in antibiotic resistance such as increases in pneumococcal resistance, emergence of multi-drug-resistant enterococcal isolates, and decreasing sensitivity of anaerobes and gram-negative rods . In addition there are new antibiotics such as piperacillin/tazobactam, and new antibiotic dosing regimens such as single daily dosing of aminoglycosides . In this article, we will review the therapeutic approach to intra-abdominal infections with special emphasis on the various forms of peritonitis, cholecystitis, cholangitis, and diverticulitis . Several new concepts about the treatment of enterococcus, the management of bacterial and fungal peritonitis, and the prevention of spontaneous bacterial peritonitis will also be reviewed . Specific recommendations for the management of the different infections including antibiotic doses and costs will be provided . Finally the role of invasive procedures in the management of some of the infections will be explored.

Antimicrob Agents Chemother, 1998 Apr, 42(4), 963 - 4
Transferable, plasmid-mediated vanB-type glycopeptide resistance in Enterococcus faecium; Rice LB et al.; An approximately 60-kb transferable, vanB-carrying plasmid has been identified in a clinical Enterococcus faecium strain . A similar plasmid has been observed in an unrelated E . faecium strain, suggesting that plasmid transfer of vanB operons occurs in nature and plays a role in the dissemination of VanB-type resistance among strains of E . faecium.

Nippon Ishinkin Gakkai Zasshi, 1998, 39(1), 17 - 25
{Augmentation of anti-Candida activity of neutrophils by macrophages treated with itraconazole}; Hara E et al.; Effects of itraconazole (ITCZ) on anti-Candida activity of a macrophage (MP)-neutrophil axis were examined in vitro . Murine peritoneal MP, stimulated by an enterococcal preparation FK-23, released tumor necrosis factor a (TNF) into the culture medium in 20 hr-culture period . This level of TNF production by the stimulated MP, which were measured by a bioassay or immunological assay, was heightened by co-stimulation with 0.5 mg/ml of ITCZ . Supernatants obtained from the culture medium of FK-23 and ITCZ-treated MP not only contained about 10 ng/ml of TNF but also had the capacity to enhance anti-Candida activity of murine neutrophils . This enhancement was blocked by pretreatment of the MP-supernatant with anti-TNF antibody . Observation by scanning electron microscope suggested that cell walls of the candida mycelia, the growth of which was inhibited by the neutrophils in the presence of either the MP-supernatant or TNF, sustained similar structural damage . These results suggest that ITCZ augments anti-Candida activity of neutrophils through enhanced production of TNF by MP in vitro.

J Bacteriol, 1998 Apr, 180(7), 1848 - 54
An exported inducer peptide regulates bacteriocin production in Enterococcus faecium CTC492; Nilsen T et al.; Production of the bacteriocins enterocin A and enterocin B in Enterococcus faecium CTC492 was dependent on the presence of an extracellular peptide produced by the strain itself . This induction factor (EntF) was purified, and amino acid sequencing combined with DNA sequencing of the corresponding gene identified it as a peptide of 25 amino acids . The gene encodes a prepeptide of 41 amino acids, including a 16-amino-acid leader peptide of the double-glycine type . Environmental factors influenced the level of bacteriocin production in E . faecium CTC492 . The optimal pH for bacteriocin production was 6.2 . At pH 5.5, growth was slow, and very little bacteriocin was formed . The presence of NaCl or ethanol (EtOH) was also inhibitory to bacteriocin production, and at high concentrations of these solutes, no bacteriocin production was observed . The induction factor induced its own synthesis, and by dilution of the culture 106 times or more, nonproducing cultures were obtained . Bacteriocin production was induced in these cultures by addition of EntF . The response was linear, and low bacteriocin production could be induced by about 10(-17) M EntF . This response was attenuated by low pH or the presence of high concentrations of NaCl or EtOH, and 300 times more EntF was needed to induce detectable bacteriocin production in the presence of 6.5% NaCl . High levels of bacteriocin production in cultures grown at low pH or in the presence of high concentrations of NaCl or EtOH were obtained by addition of sufficient amounts of EntF.

Am J Clin Pathol, 1998 Apr, 109(4), 399 - 403
Antimicrobial susceptibility testing of a clinical isolate of vancomycin-dependent enterococcus using D-alanine-D-alanine as a growth supplement; Sng LH et al.; Bacteremia due to a vancomycin-dependent enterococcus (VDE) occurred during long-term vancomycin therapy in a renal transplant recipient with underlying pancreatitis and a vancomycin-resistant enterococcal (VRE) wound infection and bacteremia . The VDE was isolated from blood during vancomycin therapy and grew only in the presence of vancomycin and D-alanine-D-alanine (DADA), a substance required for cell-wall synthesis . Colonies beyond the periphery of growth of the VDE around a vancomycin disk contained vancomycin-independent revertant mutants after 48 hours of incubation . Pulsed-field gel electrophoresis of the VDE, revertant mutant, the initial blood culture isolate of VRE, and an autopsy isolate showed that the four strains were identical . Antimicrobial susceptibility testing was performed using standard macrobroth and microbroth dilution methods . DADA was used as a growth supplement for macrobroth dilution susceptibility testing of the VDE isolate . Minimum inhibitory concentrations (MICs) were similar for the VRE isolate and the VDE revertant, which were both resistant to ampicillin, high-level gentamicin, ciprofloxacin, imipenem, vancomycin, and daptomycin, and were susceptible to fusidic acid, high-level streptomycin, rifampin, and a quinupristin-dalfopristin combination . The MICs of teicoplanin were 2 microg/mL or less and 16 microg/mL for the clinical VRE isolate and the VDE revertant, respectively . The autopsy isolate was resistant to all antimicrobials tested and showed a fourfold increase in MICs for quinupristin-dalfopristin compared with that of the original blood isolate . The VDE was susceptible to all drugs tested except vancomycin.

Pediatr Infect Dis J, 1998 Mar, 17(3), 184 - 8
An investigation of vancomycin-resistant Enterococcus faecium within the pediatric service of a large urban medical center; McNeeley DF et al.; BACKGROUND: Between 1990 to 1992 and 1993 to 1995 there was a >5-fold increase (16.7% to 89.8%) in vancomycin-resistant Enterococcus faecium isolates as a percentage of all isolates of vancomycin-resistant enterococci on the pediatric units of The New York Hospital-Cornell Medical Center (NYH-CMC) . A molecular epidemiologic investigation was undertaken to determine the extent to which this increase was associated with the spread of a vanA-containing clone of vancomycin-resistant E . faecium that had been previously defined in adults hospitalized at NYH-CMC or with the spread of another vanA clone that had been defined in children hospitalized on the pediatric service at Memorial Sloan-Kettering Cancer Center, which shares a common pediatric intensive care unit and pediatric house staff with NYH-CMC . METHODS: Molecular genotyping of vancomycin-resistant E . faecium isolates obtained from pediatric patients from 1993 to 1995 was performed by pulsed field gel electrophoresis of chromosomal SmaI digests . Southern hybridization was performed using vanA- and vanB-specific probes . Medical records of patients were reviewed for pertinent clinical and demographic information . RESULTS: A single vanB clone of vancomycin-resistant E . faecium was responsible for 17 (77.3%) of 22 isolates in the neonatal intensive care unit (NICU) of NYH-CMC . Two other vanB strains of vancomycin-resistant E . faecium and 2 vanA strains were identified among the 5 remaining NICU isolates . Vancomycin-resistant E . faecium isolates from the other pediatric units represented a heterogeneous population of primarily vanA strains, but vanA clonal strains previously identified from patients on adult services at NYH-CMC and from children hospitalized at Memorial Sloan-Kettering Cancer Center were not detected . CONCLUSION: A newly identified vanB clone was responsible for the increase in vancomycin-resistant E . faecium isolates in the NICU of NYH-CMC . The increase of vancomycin-resistant E . faecium among children hospitalized at NYH-CMC was unrelated to the spread of vancomycin-resistant E . faecium among adults in the same hospital or among children at an affiliated facility cared for by the same house staff and sharing a common pediatric intensive care unit.

J Antibiot (Tokyo), 1998 Jan, 51(1), 73 - 8
Mono and double modified teicoplanin aglycon derivatives on the amino acid no . 7; structure-activity relationship; Pavlov AY et al.; A series of 7d-aminomethylated derivatives (mono modified) and their amides (double modified) at the amino acid No . 7 of teicoplanin aglycon were prepared with the aim of obtaining activity against vancomycin-resistant VanA enterococci . Among mono modified compounds, the 7d-n-decylaminomethyl derivative was the most active against VanA enterococci (4 micrograms/ml) . Amides of the latter with 3-dimethylamino-propylamine or methylamine were found to be up to four times more active against glycopeptide-susceptible Gram-positive bacteria, and up to four times less active against VanA enterococci than the starting compound.

Zentralbl Hyg Umweltmed, 1998 Feb, 200(5-6), 457 - 64
{Inactivation of chlorhexidine for in vitro testing of disinfectants}; Kampf G et al.; An insufficient neutralization of chlorhexidine (4%), tested in vitro against Enterococcus faecium ATCC 6057, was suspected in the quantitative suspension test although the combination Tween 80, cysteine, histidine and saponine was assessed as sufficient for neutralising chlorhexidine . Bactericidal activity of each neutralising compound and their combinations was excluded . Sufficient neutralization was observed when all dilution steps and the corresponding agar plates were supplemented with the neutralising compounds . Successful neutralization in broth is not equivalent with successful neutralization in tryptic saline . We suggest to supplement at least the agar plates of the first dilution step with neutralising compounds when testing chlorhexidine.

Biotechniques, 1998 Mar, 24(3), 432 - 7
Long PCRs of transposons in the structural analysis of genes encoding acquired glycopeptide resistance in enterococci; Haaheim H et al.; Glycopeptide-resistant enterococci (GRE) associated with multiple antibiotic resistance present a major challenge to clinical practice and infection control due to limited or nonexistent antimicrobial treatment options . The genes encoding VanA- and VanB-type glycopeptide resistance have been shown to reside on transposons Tn1546 and Tn1547, respectively . These transferable genetic elements may carry the resistance determinants between and within different ecological niches . Molecular epidemiological studies of nosocomial outbreaks of VanA- and VanB-type GRE indicate horizontal transfer of glycopeptide resistance genes as an important mechanism for the spread of GRE . To target infection control and better understand the epidemiology of GRE, outbreak investigations and molecular epidemiological studies should therefore apply at least two different approaches, i.e., molecular-typing methods to analyze bacterial genomic heterogeneity and structural analysis of mobile resistance determinants . Here we describe the development and use of long PCRs in the structural analysis of vanA and vanB gene clusters in GRE.

J Community Health Nurs, 1998, 15(1), 9 - 20
Transmission of vancomycin-resistant enterococcus among family members: a case study; Neuman K et al.; Enterococci are persistent organisms naturally occurring in the digestive tract, able to persist on environmental surfaces for days or weeks, surviving heat and desiccation . They are the second most common bacterial cause of nosocomial infection . Recent strains of enterococci resistant to vancomycin pose a serious health hazard to hospitalized, institutionalized, and immunocompromised patients . This article presents a case study of community-acquired vancomycin-resistant enterococcus in an otherwise healthy child and suggests strategies for management and containment in the community.

Bioorg Khim, 1997 Nov, 23(11), 851 - 67
{Glycopeptide antibiotics resistance mechanism as the basis for novel derivatives development capable to overcome resistance}; Trenin AS et al.; The data on the genetic and biochemical bases of bacterial resistance to antibiotics of the vancomycin-ristocetin group are summarized . Special emphasis is placed on the mechanism of resistance associated with target modification and on molecular interactions occurring upon contact of glycopeptides with normal and modified targets . The prospects for developing new derivatives active against resistant bacteria are discussed . The most rational approach to the chemical transformation of glycopeptides involves the modification of the internal "binding pocket" and the peripheral regions of the molecule that participate in the stabilization of the antibiotic-target complex . Novel semisynthetic drugs of this group active against glycopeptide-resistant enterococci are described.

Antimicrob Agents Chemother, 1998 Mar, 42(3), 534 - 9
The gene encoding the low-affinity penicillin-binding protein 3r in Enterococcus hirae S185R is borne on a plasmid carrying other antibiotic resistance determinants; Raze D et al.; Two plasmid-derived NcoI DNA fragments of 14 and 4.5 kb, respectively, have been isolated from the multidrug-resistant strain Enterococcus hirae S185R and analyzed . The 14-kb fragment contains two inverted (L and R) IS1216 insertion modules of the ISS1 family . These modules define a Tn5466 transposon-like structure that contains one copy of the methylase-encoding ermAM conferring erythromycin resistance and one copy of the adenylyl-transferase-encoding aadE conferring streptomycin resistance . Immediately on the left side of IS1216L there occurs a copy of pbp3r encoding the low-affinity penicillin-binding protein (PBP) PBP3r, itself preceded by a psr-like gene (psr3r) that controls the synthesis of PBP3r . ermAM, aadE, and the transposase gene (tnp) of IS1216R have the same polarities, and these are opposite those of psr3r, pbp3r, and the tnp gene of IS1216L . The 4.5-kb fragment is a copy of the 4.5-kb sequence at the 5' end of the 14-kb fragment, although it is not a restriction product of the 14-kb fragment . It contains three genes with the same polarity: psr3r, pbp3r, and tnp in an IS1216 element . Because of the very high degree of identity (99%) with the chromosomal psrfm and pbp5fm genes of Enterococcus faecium D63R, it is proposed that both the psr3r and pbp3r genes were transferred from an E.faecium strain and inserted in a plasmid of E . hirae . E . hirae is the first known bacterial species in which a low-affinity PBP-encoding gene has been found to be plasmid borne.

Antimicrob Agents Chemother, 1998 Mar, 42(3), 502 - 8
Diversity of VanA glycopeptide resistance elements in enterococci from humans and nonhuman sources; Woodford N et al.; Elements mediating VanA glycopeptide resistance in 106 diverse enterococci from humans and nonhuman sources were compared with the prototype VanA transposon, Tn1546, in Enterococcus faecium BM4147 . The isolates included 64 from individual patients at 15 hospitals in the United Kingdom (isolated between 1987 and 1996) and 42 from nonhuman sources in the United Kingdom (27 from raw meat, 7 from animal feces, and 8 from sewage) . VanA elements were assigned to 24 groups (designated groups A to X) with primers that amplified 10 overlapping fragments of Tn1546 . Ten groups of elements were found only in human enterococci, eight groups of elements were unique to nonhuman strains, and six groups of elements were common in enterococci from all sources . Elements indistinguishable from Tn1546 (group A) were observed more frequently in enterococci from nonhuman sources (34 versus 9%) but were identified in enterococci that caused outbreaks in hospital patients between 1987 and 1995 . The most common group found in human enterococci (group H; 33%) was rarely observed in enterococci from other sources (5%) . Group H elements differed from Tn1546 in three regions and included a novel insertion sequence, designated IS1542, between orf2 and vanR . The VanA elements of 14 other groups had a similar insertion at this position and/or distinct insertions at other positions . We conclude that VanA elements in enterococci are heterogeneous, although all show regions of homology with Tn1546 . Furthermore, the elements most common among the human and nonhuman enterococci studied were different . This approach may be useful for monitoring the evolution of VanA resistance and may also be applicable in local "snapshot" epidemiological studies . However, as transposition events involving insertion sequences accounted for the differences observed between several groups, the stability of the elements must be assessed before their true epidemiological significance can be determined.

J Antimicrob Chemother, 1997 May, 39 Suppl A, 145 - 51
Effect of quinupristin/dalfopristin on the outcome of vancomycin-resistant Enterococcus faecium bacteraemia: comparison with a control cohort; Linden PK et al.; Serious infection with vancomycin-resistant Enterococcus faecium (VREF) strains has no proven effective antimicrobial therapy . We compared the clinical and bacteriological outcomes of 20 patients with VREF bacteraemia treated with quinupristin/dalfopristin (RP 59500), an investigational streptogramin, with a historical cohort of 42 patients with VREF bacteraemia treated with other agents . Quinupristin/dalfopristin demonstrated in-vitro bacteriostatic activity against all 20 initial VREF blood isolates (MIC range 0.03-0.50 mg/L) by macrobroth dilution . The clinical characteristics of both groups were comparable for major outcome-dependent variables . There were five cases of recurrent VREF bacteraemia in the quinupristin/dalfopristin-treated cohort and 21 in the controls (P = 0.11); persistence of VREF at the primary site was found in six and 18 of the evaluable patients with follow-up cultures in these two cohorts (P = 0.06) . In-hospital mortality was high in both groups: 65% in the quinupristin/dalfopristin group and 52% in the control group; however, VREF-associated mortality was significantly lower in the quinupristin/dalfopristin group (five and 17 respectively; P = 0.05) . Follow-up susceptibility testing of five VREF isolates in the quinupristin/ dalfopristin group did not demonstrate resistance to quinupristin/dalfopristin . Quinupristin/ dalfopristin may be a useful agent for the therapy of serious VREF infection . Further clinical investigations are warranted to confirm or refute its clinical efficacy.

J Antimicrob Chemother, 1997 May, 39 Suppl A, 109 - 13
The effect of antibiotic exposure on adherence to neutrophils of Enterococcus faecium resistant to phagocytosis; Herrera-Insua I et al.; Many clinical isolates of Enterococcus faecium are resistant to neutrophil-mediated phagocytosis and killing . As antibiotic exposure may alter bacterial surface properties and promote phagocytosis, we used a fluorescence microscopy assay to examine the effect of antibiotic pretreatment on the resistance to phagocytosis of six strains of E . faecium . Using two antimicrobial agents with good in-vitro activity against E . faecium, namely quinupristin/ dalfopristin and sparfloxacin, we found that exposure to quinupristin/dalfopristin at concentrations both below and above the MIC promoted bacterial adherence to neutrophils (PMNs) for all of three strains of vancomycin-susceptible E . faecium, while sparfloxacin was similarly effective in two of these three strains . In contrast, neither antibiotic was effective in promoting PMN adherence for three vancomycin-resistant strains of E . faecium . The variability amongst strains in response to antibiotic exposure suggests that either the mechanisms of resistance to phagocytosis, or its regulation, may be different amongst different strains of E . faecium.

J Antimicrob Chemother, 1997 May, 39 Suppl A, 63 - 6
Synergic activity of vancomycin-quinupristin/dalfopristin combination against Enterococcus faecium; Lorian V et al.; Clinical specimens were cultured, and the strains identified by the Vitek system as Enterococcus faecium were characterized by their DNA . The MIC vancomycin, quinupristin/dalfopristin and teicoplanin for each isolate was determined . Ten vancomycin-sensitive and ten vancomycin-resistant strains of E . faecium were tested . Quinupristin/dalfopristin at 0.25 x MIC and vancomycin at 0.5 x MIC separately as well as in combination were added to Trypticase Soy Broth tubes inoculated with a 24 h culture . The results obtained by determining cfu at 2, 4, 8, 12 and 24 h indicated that the combination of subinhibitory concentrations of quinupristin/dalfopristin plus vancomycin produced after 24 h, in vancomycin-resistant strains, a consistent degree of synergy . Synergy was observed up to only 12 h when similar combinations were employed for vancomycin-sensitive strains . Vancomycin-sensitive strains tended to be slightly less susceptible to quinupristin/dalfopristin than vancomycin-resistant strains.

J Antimicrob Chemother, 1997 May, 39 Suppl A, 23 - 8
Bactericidal and inhibitory activity of quinupristin/dalfopristin against vancomycin- and gentamicin-resistant Enterococcus faecium; Hill RL et al.; There is a need for new agents, or combinations of agents, for the treatment of infections caused by vancomycin- and gentamicin-resistant Enterococcus faecium (VGREF) that may be resistant to all available antimicrobial agents . The early in-vitro activity of quinupristin/dalfopristin (30:70)--an injectable streptogramin--encouraged us to test this agent against VGREF . By broth dilution, the MICs of quinupristin/dalfopristin against 38 isolates of VGREF ranged from 0.06 mg/L to 2.0 mg/L (mode 0.12 mg/L) . The addition of 0.5 mg/L of ciprofloxacin significantly reduced the modal MIC of quinupristin/dalfopristin to 0.015 mg/L (P = 5.75 x 10(-8)) . Although the addition of 8.0 mg/L of teicoplanin or 4 mg/L of tetracycline did not significantly reduce the modal MIC, the lowest concentration of the MIC range was reduced from 0.06 to 0.015 mg/L . In broth, quinupristin/dalfopristin had slow bactericidal activity against the four strains tested over 48 h, with a 1-2 log10 cfu/mL reduction after 24 h in > 1 mg/L of quinupristin/dalfopristin for two strains and > 8 mg/L for the two other strains . A mixture of quinupristin/dalfopristin in a 70:30 ratio was more bactericidal: against one of the four strains 4-32 mg/L of the combination produced a further 0.5-1.0 log10 reduction in cfu/mL after 24 h and there was a reduction of 6.0 log10 cfu/mL after 48 h for another . By ultracentrifugation, the binding of 32 mg/L quinupristin/dalfopristin to human plasma protein was 90%, and in plasma broth, 32 mg/L of quinupristin/dalfopristin maintained bacteriostatic but not bactericidal activity . There is some useful synergy with ciprofloxacin and tetracycline, and the activity of quinupristin/dalfopristin may be enhanced against some strains by reversing the concentrations of its two components, quinupristin and dalfopristin, as that may occur in vivo.

Infect Control Hosp Epidemiol, 1998 Feb, 19(2), 109 - 12
Absence of rectal colonization with vancomycin-resistant enterococci among high-risk pediatric patients; Trabulsi A et al.; We prospectively surveyed for rectal colonization with vancomycin-resistant Enterococcus among 93 high-risk pediatric patients who were hospitalized at least 5 (median, 20) days . Fifty-two patients (56%) had enterococcal colonization; none had active infection with Enterococcus . All enterococci were vancomycin-susceptible (minimum inhibitory concentration < or =4 microg/mL) . Associated exposures included recent antibiotics (50, 96%), surgical procedures (26, 58%), and immunosuppression (15, 29%).

Pa Med, 1997 Oct, 100(10), 30 - 2
Vancomycin-resistant enterococci: an emerging health problem; Whittle J et al.; Since 1995, KePRO has worked with the peer review organization for 13 other states/commonwealths and the District of Columbia, as well as the Boston Regional Office of the Health Care Financing Administration, in the implementation of the largest study ever conducted involving Vancomycin-resistant enterococci (VRE) . Fifteen Pennsylvania hospitals volunteered to participate in the study, designed to identify and assess the appropriateness of vancomycin use, contributing 19 percent of the total records used in the baseline study . This article, the first of two, describes VRE and its increasing prevalence . In the second installment, we will describe patterns of vancomycin use identified in KePRO's study of participating Pennsylvania hospitals, as well as the steps these hospitals are taking to control antibiotic use . Since all data gathered by KePRO are protected by federal confidentiality guidelines, the facilities that graciously agreed to pioneer KePRO's vancomycin utilization project will not be identified or identifiable.

Zhonghua Yi Xue Za Zhi (Taipei), 1998 Jan, 61(1), 53 - 8
Infective endocarditis complicated with thalamic infarction and mycotic aneurysm rupture: a case report; Hung SC et al.; A 39-year-old female with mitral valve prolapse experienced left side hemisensory disturbance four months after gastric surgery . Echocardiogram disclosed vegetation on the mitral valve and blood cultures showed growth of enterococcus . With a diagnosis of thalamic infarction complicating infective endocarditis, she was hospitalized for further treatment . After four weeks of antibiotic therapy, she developed sudden headache and obtundation . Imaging studies revealed intracerebral hemorrhage (ICH), resulting from mycotic aneurysm rupture . She survived and recovered after emergency craniotomy and evacuation of the hematoma . However, the ICH recurred six weeks later and the patient died after five days in a deep coma . Patients with mitral valve prolapse are common . Those who have systolic murmur or valvular thickening and redundancy are at particular risk of infective endocarditis and should receive antibiotic prophylaxis perioperatively as recommended by the American Heart Association . Clinical manifestations of infective endocarditis and its complications, as in our patient, are often trivial . Prompt diagnosis and intervention are crucial . In view of the poor prognosis associated with ICH due to mycotic aneurysm rupture, we suggest cerebral angiography be performed in patients presenting with focal neurologic deficits or with warning headache for early detection of accessible lesions for excision.

Am J Infect Control, 1998 Feb, 26(1), 40 - 6
Vancomycin-resistant Enterococcus faecium in a Veterans Affairs Medical Center: association with antibiotic usage; Dever LL et al.; BACKGROUND: Colonization and infection with vancomycin-resistant Enterococcus faecium (VREF) has been associated with the use of vancomycin and other antibiotics in individual patients . The objective of this study was to determine the association of VREF with the aggregate usage of antibiotics on nursing units in a hospital . METHODS: This was a retrospective correlation study . A usage ratio was calculated for each parenteral antibiotic on each nursing unit as the per-bed usage by weight of that antibiotic divided by its average usage throughout the hospital . An average usage ratio (AUR) for each nursing unit was calculated as the mean of usage ratios of individual antibiotics . The AUR was used to compare the usage of antibiotics among nursing units in the hospital . The incidence of VREF infections on individual nursing units in a Veterans Affairs Medical Center was correlated with the usage of parenteral antibiotics separately and in aggregate in univariate and multivariate regression analyses . RESULTS: The AUR was strongly and positively correlated with the recovery of VREF on individual nursing units . By univariate analyses, increasing use of each antibiotic tested was associated with isolation of VREF but only clindamycin remained significant in the multivariate model . However, usage of various antibiotics was highly interrelated, and only clindamycin usage was significantly correlated with usage of all other antibiotics studied . Intensive care and acute care units and units with fewer patient beds were more likely to have patients with VREF infection than were subacute care units (p < 0.003) or larger units (p < 0.01) . CONCLUSIONS: VREF infections were associated with greater aggregate antibiotic use on nursing units . Determination of antibiotic usage ratios may provide a convenient and useful tool for examining the association of antibiotic usage with other nosocomial infections.

Arch Intern Med, 1998 Mar 9, 158(5), 522 - 7
Enterococcus faecium bacteremia: does vancomycin resistance make a difference?
Stosor V, Peterson LR, Postelnick M, Noskin GA.
BACKGROUND: Enterococcus faecium has received increased attention, primarily due to the emergence of vancomycin resistance . The purpose of this investigation was to study the epidemiological characteristics of vancomycin-resistant E faecium (VRE) bacteremia and to determine the clinical impact of vancomycin resistance on the outcome of patients with this infection . METHODS: We retrospectively analyzed the clinical features and outcome of 53 patients with E faecium bacteremia . RESULTS: From January 1992 until December 1995, there were 32 episodes of bacteremia caused by vancomycin-susceptible E faecium (VSE) and 21 caused by VRE . An intra-abdominal site was the most common source of bacteremia in both groups . All of the VRE and 78% of VSE bacteremia cases were nosocomially acquired . Previous administration of vancomycin was associated with VRE bacteremia (P<.001), as were indwelling bladder catheters (P=.01) . Fifty-nine percent of the patients with VSE bacteremia survived vs 24% with VRE (P=.009), despite similar severity-of-illness scores . In 62% of the patients with VRE sepsis, death was related to the bacteremia (P=.01) . Patients infected with VRE had longer hospitalizations than those with VSE (34.8 vs 16.7 days, respectively) (P=.004), were more likely to be on the medical service (P=.03), and on the average, had hospitalization costs of more than $27,000 per episode than did patients with VSE bloodstream infection ($83,897 vs $56,707, respectively) (P=.04) . CONCLUSIONS: Vancomycin-resistant E faecium bacteremia is a complication of prolonged hospitalization in debilitated patients . Vancomycin resistance has a negative impact on survival in patients with E faecium bacteremia and leads to higher health care costs.

Emerg Infect Dis, 1998 Jan-Mar, 4(1), 37 - 47
Diversity among multidrug-resistant enterococci; Murray BE; Enterococci are associated with both community- and hospital-acquired infections . Even though they do not cause severe systemic inflammatory responses, such as septic shock, enterococci present a therapeutic challenge because of their resistance to a vast array of antimicrobial drugs, including cell-wall active agents, all commercially available aminoglycosides, penicillin and ampicillin, and vancomycin . The combination of the latter two occurs disproportionately in strains resistant to many other antimicrobial drugs . The propensity of enterococci to acquire resistance may relate to their ability to participate in various forms of conjugation, which can result in the spread of genes as part of conjugative transposons, pheromone-responsive plasmids, or broad host-range plasmids . Enterococcal hardiness likely adds to resistance by facilitating survival in the environment (and thus enhancing potential spread from person to person) of a multidrug-resistant clone . The combination of these attributes within the genus Enterococcus suggests that these bacteria and their resistance to antimicrobial drugs will continue to pose a challenge.

Rev Assoc Med Bras, 1997 Jul-Sep, 43(3), 217 - 22
{Evaluation of antimicrobial sensitivity of 87 clinical isolates of vancomycin-resistant enterococci}; Saraiva IH et al.; OBJECTIVES: 1) To evaluate the antimicrobial susceptibility pattern of vancomycin-resistant enterococci to the antimicrobial agents that are commonly used to treat enterococci infections and to some alternative drugs . 2) To evaluate the accuracy of E test for susceptibility testing enterococci . MATERIAL AND METHOD: We evaluated 87 clinical VRE isolates that were selected from a previous study which analyzed 1936 clinical isolates collected and processed in 97 US medical centers in the last quarter of 1992 . The isolates were identified to the species level by using the API 20S System, the Vitek gram-positive identification cards and a modified version of the conventional method proposed by Facklam and Collins . The in vitro susceptibility testing was performed by broth microdilution, E test and disk diffusion methods, following the criteria described by the National Committee for Clinical Laboratory Standards (NCCLS) . The VRE isolates were tested against antimicrobial agents commonly used to treat enterococci infections (vancomycin, teicoplanin, ampicillin, penicillin, gentamicin and streptomycin) and against ten potential alternative drugs (chloramphenicol, doxycycline, sparfloxacin, ciprofloxacin, clinafloxacin, erythromycin, spectinomycin, trospectomycin, trimetoprim-sulfametoxazol and novobiocin) . RESULTS: Our results showed a high rate of resistance to ampicillin and penicillin (86%) . High level resistance to gentamicin and streptomycin was demonstrated by 82% and 85% respectively . Although teicoplanin and vancomycin belong to the same antibiotic group (glycopeptide), 29% of VRE were susceptible to teicoplanin . Among the alternative drugs, trospectomycin, doxycyclin and chloramphenicol showed the highest in vitro activity, with 94%, 92% and 82% susceptibility respectively . In addition, erythromycin, trimetoprim-sulfametoxazol and ciprofloxacin showed the highest rates of resistance (98%, 83% and 69%, respectively) . CONCLUSION: The treatment options for infections caused by vancomycin-resistant enterococci seem to be very narrow since a small percentage of those isolates were susceptible to the other antimicrobial agents commonly used to treat these infections and only a few of the alternative drugs tested showed good in vitro activity . Many regimens using various antibiotic combinations have been tested against VRE, most of them with fluoroquinolones . However further studies are necessary to evaluate the clinical role of these antibiotic combinations.

Curr Microbiol, 1998 Feb, 36(2), 114 - 8
Relationship of K+-uptaking system with H+-translocating ATPase in Enterococcus hirae, grown at a high or low alkaline pH; Trchounian A et al.; Potassium ion pool was studied in glycolyzing Enterococcus hirae, grown at high or low alkaline pH (pH 9.5 and 8.0, respectively) . Energy-dependent increase of K+ pool was lower for the wild-type cells, grown at pH 9.5, than that for the cells grown at pH 8.0 . It was inhibited by N,N'-dicyclohexylcarbodiimide (DCCD) . The stoichiometry of DCCD-inhibited K+ influx to DCCD-inhibited H+ efflux for the wild-type cells, grown at pH 9.5 or 8.0, was fixed for different K+ external activity . DCCD-inhibited ATPase activity of membrane vesicles was significantly stimulated by K+ for the wild-type cells grown at pH 9.5, and required K+ for the wild-type cells grown at pH 8.0, while the levels of alpha and beta subunits of the F1 and b subunit of the F0 were lower for the cells grown at pH 9.5 than that for the cells grown at pH 8.0 . Such an ATPase activity was residual in membrane vesicles from the atpD mutant with a nonfunctional F0F1 . ATPase activity of membrane vesicles from the mutant with defect in Na+-ATPase was higher for the cells grown at pH 9.5 than that for the cells grown at pH 8.0, and was inhibited by DCCD . An energy-dependent increase of K+ pool in this bacterium, grown at a high or low alkaline pH, is assumed to occur through a K+ uptaking system, most probably the Trk . The latter functions in a closed relationship with the H+-translocating ATPase F0F1.

Transplantation, 1998 Feb 15, 65(3), 439 - 42
Incidence and outcome of infection by vancomycin-resistant Enterococcus following orthotopic liver transplantation; Newell KA et al.; Vancomycin-resistant Enterococcus (VRE) has become a significant nosocomial pathogen . For this study, the records of 325 patients who underwent orthotopic liver transplantation (OLT) were reviewed . Thirty-four patients were infected by VRE (incidence of 10.5%, 14% in adults vs . 5% in children, P < 0.01) . Common features of patients who developed infections with VRE included previous antibiotic use (25 patients, 15 of whom received vancomycin), co-infection by other pathogens (28 patients), and relaparotomy following OLT (20 patients) . Pulmonary and/or renal failure preceded infection by VRE in 11 and 4 adult patients, respectively . Biliary complications were exceedingly common in patients infected by VRE (28 patients) and significantly increased the risk of infection by VRE (21.5% vs . 3.1% for patients without biliary complications, P < 0.0001) . Mortality associated with VRE infections was high (56% vs . 19% for patients not infected by VRE, P < 0.0005) . The most frequent cause of death was sepsis (16 of 19 patient deaths), often polymicrobial . The high incidence of infection by VRE following OLT, the lack of effective antibiotics for the treatment of VRE, and the association of VRE with patient mortality emphasizes the need to define the risk factors associated with VRE infection . We suggest early surgical intervention to treat complications that may predispose patients to infection by VRE.

J Clin Microbiol, 1998 Feb, 36(2), 592 - 4
Comparison of eight methods to detect vancomycin resistance in enterococci; Endtz HP et al.; A collection of genetically unrelated vancomycin-resistant enterococci (VRE) including 50 vanA, 15 vanB, 50 vanC1, and 30 vanC2 VRE were used to evaluate the accuracy of eight currently available susceptibility test methods (agar dilution, disk diffusion, E-test, agar screen plate, Vitek GPS-TA and GPS-101, and MicroScan overnight and rapid panels) . vanA VRE were detected by all methods . vanB VRE were often not detected by Vitek GPS-TA and MicroScan rapid (sensitivities, 47 and 53%, respectively), though the new Vitek GPS-101 was found to be a significant improvement . E-test and the agar screen were the only two methods detecting all VRE, including the vanC1/C2 VRE.

J Clin Microbiol, 1998 Feb, 36(2), 437 - 42
Molecular analysis of Tn1546 in Enterococcus faecium isolated from animals and humans; Jensen LB et al.; The internal areas and the position of integration of the glycopeptide resistance element Tn1546 were characterized by using PCR fragment length polymorphism, sequencing, and DNA hybridization techniques with 38 high-level vancomycin-resistant Enterococcus faecium isolates of human and animal origins from Europe and the United States . Only minor variations in the coding regions within Tn1546 were found, suggesting high genetic stability . The isolates originated from broilers (n = 5), a chicken (n = 1), a duck (n = 1), a turkey (n = 1), pigs (n = 8), a pony (n = 1), and humans (n = 23) . A total of 13 different types were defined based on a single-nucleotide difference in the vanX gene, the presence of insertion sequences, and hybridization patterns . For some types more than one isolate were found . For type 1, 10 isolates of both human and animal origins were found . All were indistinguishable from the reference strain, BM4147 . For type 2, 11 isolates of human and animal origins were found . Six human isolates from England were all of type 3 . Two human isolates from the United States, indistinguishable from each other, were type 9 . These results showed that vancomycin-resistant E . faecium of animal and human origins can contain indistinguishable genetic elements coding for vancomycin resistance, indicating either horizontal gene transfer between E . faecium organisms of human and animal origins or the existence of a common reservoir for glycopeptide resistance.

J Infect Dis, 1998 Feb, 177(2), 378 - 82
Stability of vancomycin-resistant enterococcal genotypes isolated from long-term-colonized patients; Bonten MJ et al.; Genotypic variation and stability of isolates of vancomycin-resistant enterococci (VRE) were studied to determine genetic diversity and whether strain definition based on pulsed-field gel electrophoresis (PFGE) is applicable to an endemic setting . Twenty-two PFGE types were identified among 455 VRE isolates . One-on-one comparisons of 10 vanA Enterococcus faecium strain types all yielded > 10 band differences . Variations among vanA and vanB E . faecium isolates from individual long-term-colonized (4-160 days) patients yielded < 3 band differences for > 85% of comparisons . Comparison of all strains without grouping by vancomycin resistance types yielded two peaks of band differences: one with < 3 and one with > 10 band differences . These data show that VRE isolates were genetically closely related or very different; demonstrate that within individual patients, VRE isolates show little genetic variation; and provide empirical evidence that PFGE can be used to study the epidemiology of VRE endemicity.

Eur J Pediatr, 1998 Jan, 157(1), 20 - 7
Control of a nosocomial outbreak of vancomycin resistant Enterococcus faecium in a paediatric oncology unit: risk factors for colonisation; Nourse C et al.; In order to determine the extent of vancomycin resistant enterococcus (VRE) colonisation within a paediatric oncology unit, the risk factors for the acquisition of the organism, the molecular epidemiology of the isolates and the impact of infection control measures, extensive patient and environmental surveillance was undertaken with identification, antibiotic susceptibility testing and pulsed-field gel electrophoresis (PFGE) of all VRE isolates . A matched case control study was carried out . Fourteen patients (19% of screened patients) with VRE colonisation were identified (12 with Enterococcus faecium) . All isolates manifested the Van A phenotype . Extensive environmental contamination with VRE was present . PFGE of E . faecium isolates from 10 patients and from five of six environmental cultures revealed patterns suggesting genetic relatedness . Following comparison of the 14 cases with 41 controls matched for age (+/- 4 years) and cohabitation on the oncology unit, risk factors for colonisation with VRE included duration of neutropenia, (OR, 3.72; 95% CI, 1.0-13.1), and antibiotic therapy, (OR, 4.07; 95% CI, 1.08-15.3), the number of antibiotic agents received, (OR, 8.4; 95% CI, 1.34-34.3) and the duration of therapy with amikacin, (OR, 10.7; 95% CI, 1.4-81.5), ceftazidime, (OR, 11.5; 95% CI, 2.2 59.9) or teicoplanin, (OR, 12.3; 95% CI, 2.25-67.4) . Implementation of stringent infection control measures reduced environmental contamination from 25% of samples in week 1 to none in week 11 . Two additional colonised patients were identified during the subsequent 6 months . CONCLUSION: Risk factors for VRE colonization in paediatric oncology patients included duration of neutropenia, duration of any antibiotic therapy, exposure to ceftazidime, amikacin or teicoplanin and the number of antibiotics used . The study suggests that environmental contamination played an important role in patient-to-patient transmission of VRE and interventions including implementation of infection control measures were associated with a decreased incidence of gastro-intestinal colonisation.

Diagn Microbiol Infect Dis, 1997 Dec, 29(4), 233 - 9
In vitro activity of the combination of trovafloxacin and other antibiotics against enterococci; Schick DG et al.; The activities of trovafloxacin and ciprofloxacin against 38 strains of non-beta-lactamase-producing enterococci, resistant to ampicillin, 34 strains susceptible to ampicillin, and 3 vancomycin-resistant enterococci were studied . Trovafloxacin was more active than ciprofloxacin against all the enterococci studied . The ampicillin-resistant strains were more susceptible than the ampicillin-susceptible strains to both agents . The effect of combining trovafloxacin with gentamicin, ampicillin-sulbactam, novobiocin, rifampin, teicoplanin, and vancomycin was determined for 17 strains by the checkerboard method . An additive effect by inhibition was seen with all antibiotics studied . The results by killing varied with the different agents studied . Gentamicin, ampicillin-sulbactam, and novobiocin produced an additive killing effect with trovafloxacin . Reduced killing was seen when rifampin, vancomycin, or teicoplanin were added to trovafloxacin.

Kyobu Geka, 1998 Jan, 51(1), 79 - 81
{Acute myocardial infarction due to traumatic hemorrhagic shock with open fracture: a case report of staged amputation and CABG}; Sakakibara Y et al.; A 55-years-old man was admitted to an emergent hospital with hypovolemic pre-shock and open fracture of the right lower extremity . CPR was needed for myocardial infarction induced by hemorrhagic shock . Wound infection and bacteremia (Enterococcus SP) were noted 10 days after admission . Severe three vessel disease was demonstrated by preoperative (amputation) evaluation, he was also referred for CABG . For a control of infectious focus before using cardiopulmonary bypass, two-stage-operation (amputation and CABG) were selected . Both perioperative courses were uneventful and the patient recovered well after rehabilitation.

An Med Interna, 1997 Sep, 14(9), 465 - 6
{Enterococcal infective endocarditis on native aortic valve}; Becares Lozano M et al.; Enterococcal endocarditis accounts for 10% of all bacterial endocardits . The infection progresses in a subacute way and when localized on the aortic valve it has a very poor prognosis since the valve is usually destroyed being death the fatal outcome . We report a case of a patient with infective endocarditis resulting from the implantion of the Enterococcus on the native aortic valve . Nor visk factors or an apparent main gate could be found . The patient was hospitalized after several months of a non especific febrile syndrome . The literature is reviewed . Diagnostic tests and clinical signs are discussed making emphasis on the refractoriness to chemotherapy.

Int J Biochem Cell Biol, 1997 Nov, 29(11), 1245 - 54
Copper deficiency and heart disease: molecular basis, recent advances and current concepts; Nath R; Copper is an essential trace element and has profound influence on cardiac myopathy and heart metabolism . Dietary Cu restriction in rats results in cardiomyopathy, and affects the integrity of the basal lamina of cardiac myocytes and capillaries . Decreased levels of delta subunits of ATP synthetase and nuclear encoded subunits of cytochrome oxidase system have been observed . Alteration in expression of glutathione peroxidase and catalase in heart and liver in Cu deficiency (Cu-) has been noted involving both transcriptional and post transcriptional mechanisms . A short description of two genetically inherited disorders of Cu metabolism, i.e . Wilson's disease and Menkes' disease, and Indian childhood cirrhosis (environmental and/or genetic) have been included to illustrate that advances in the knowledge of Cu cellular transport gives a better understanding of the molecular basis of the pathophysiology of these diseases . Menkes' disease, a human model of defective Cu transport and Cu- has shown many pathological changes, similar to those of heart disease in Cu- . The recent cloning of four genes of putative Cu pumping ATPases (Cu-ATPases) from widely different sources, i.e . two from Enterococcus hirae and one each from Wilson's and Menkes disease patients (which are defective in Cu transport and metabolism), has opened a new chapter in the study of Cu cellular transport and metabolism . The encoded gene products, i.e . Cu-ATPases, show extensive homology and are members of a new class of ATP-driven Cu pumps involved in regulation of cellular Cu . Further, Cu transport by Cop B-ATPase (E . hirae) in membrane vesicles and in isolated rat liver plasma membrane has provided biochemical evidence of its role in ATP-driven Cu transport . In this short review I have critically examined the current evidence of the molecular basis of the pathophysiology of cardiomyopathy in Cu- and, have indicated the possible role of P-type Cu ATPase which may be one of the obligatory factors contributing to cardiomyopathy in experimental animals and probably humans . Experimental verification of this hypothesis will be the aim of future studies.

Recenti Prog Med, 1997 Nov, 88(11), 507 - 12
{Enterococcal endocarditis: clinical features and therapeutic approach}; Perrone A et al.; Enterococci are implicated in about 20% of cases of infective endocarditis, topically in aged subjects with gastro-intestinal and/or genitourinary diseases . These forms are usually associated with an increased morbidity and mortality, in that also reflecting the difficulties encountered to set up a specific therapeutic approach . Among the various antibiotics effective against enterococci, particular attention has been recently given to those belonging to glycopeptide group . In the current study we have assessed the efficacy of teicoplanin associated to ampicillin plus sulbactam in 27 consecutive patients with enterococcus-mediated endocarditis, admitted to our hospital between June 1987 and September 1995 . In 17 patients the source of infection has been identified in the gastrointestinal tract . The clinical recovery and the bacteriologic eradication have been achieved in 24/27 (88.8%) patients . The results indicate the necessity of a prophylactic antibiotic treatment in aged individuals with diseases affecting the gastrointestinal tract and further suggest the efficacy of teicoplanin and ampicillin plus sulbactam association for the treatment of endocarditis caused by enterococci.

Can Nurse, 1997 Nov, 93(10), 36 - 9
Managing vancomycin-resistant enterococci . A winning team approach; Robinson K et al.; Antibiotics have been the treatment of choice for a broad range of bacterial infections for decades . In recent years, however, concern has been growing over the increasing incidence of infections that are resistant to known antibiotics . A 1995 outbreak of ampicillin- and vancomycin-resistant enterococci (VRE) at the 3Y site of the McMaster University Medical Centre brought this concern home to us and resulted in the development of outbreak-management guidelines for VRE.

J Bacteriol, 1998 Jan, 180(2), 317 - 29
Properties of the P-type ATPases encoded by the copAP operons of Helicobacter pylori and Helicobacter felis; Bayle D et al.; The cop operons of Helicobacter pylori and Helicobacter felis were cloned by gene library screening . Both operons contain open reading frames for a P-type ion pump (CopA) with homology to Cd2+ and Cu2+ ATPases and a putative ion binding protein (CopP), the latter representing a CopZ homolog of the copYZAB operon of Enterococcus hirae . The predicted CopA ATPases contained an N-terminal GMXCXXC ion binding motif and a membrane-associated CPC sequence . A synthetic N-terminal peptide of the H . pylori CopA ATPase bound to Cu2+ specifically, and gene disruption mutagenesis of CopA resulted in an enhanced growth sensitivity of H . pylori to Cu2+ but not to other divalent cations . As determined experimentally, H . pylori CopA contains four pairs of transmembrane segments (H1 to H8), with the ATP binding and phosphorylation domains lying between H6 and H7, as found for another putative transition metal pump of H . pylori (K . Melchers, T . Weitzenegger, A . Buhmann, W . Steinhilber, G . Sachs, and K . P . Schafer, J . Biol . Chem . 271:446-457, 1996) . The corresponding transmembrane segments of the H . felis CopA pump were identified by hydrophobicity analysis and via sequence similarity . To define functional domains, similarly oriented regions of the two enzymes were examined for sequence identity . Regions with high degrees of identity included the N-terminal Cu2+ binding domain, the regions of ATP binding and phosphorylation in the energy transduction domain, and a transport domain consisting of the last six transmembrane segments with conserved cysteines in H4, H6, and H7 . The data suggest that H . pylori and H . felis employ conserved mechanisms of ATPase-dependent copper resistance.

Scand J Infect Dis . 1997;29(5):530.
Endocarditis caused by Enterococcus avium; Perez-Castrillon JL et al.; Enterococcus avium has rarely been reported as a pathogen in humans . We describe a case of endocarditis caused by E . avium . It responded to ampicillin and gentamicin, although a valve replacement was necessary for severe aortic insufficiency . This microorganism should be regarded as significant in endocarditis.

Infect Dis Clin North Am, 1997 Dec, 11(4), 851 - 65
Vancomycin-resistant enterococci . Mechanism and clinical relevance; Eliopoulos GM; Vancomycin-resistant enterococci have spread widely throughout the United States . Mechanisms of glycopeptide resistance are understood to a significant extent . These organisms are associated with considerable morbidity . Treatment options are limited, and control of their spread requires considerable effort and results in increased costs.

Antimicrob Agents Chemother, 1997 Dec, 41(12), 2749 - 53
Influence of erythromycin resistance, inoculum growth phase, and incubation time on assessment of the bactericidal activity of RP 59500 (quinupristin-dalfopristin) against vancomycin-resistant Enterococcus faecium; Caron F et al.; RP 59500, a mixture of two semisynthetic streptogramin antibiotics (quinupristin and dalfopristin), is one of a few investigational agents currently in clinical trials with inhibitory activity against multiple-drug-resistant strains of Enterococcus faecium . We evaluated the bactericidal activity of this antimicrobial against 30 recent clinical isolates of vancomycin-resistant E . faecium, including 23 erythromycin-resistant (MIC, >256 microg/ml) and 7 erythromycin-intermediate (MIC, 2 to 4 microg/ml) strains . All isolates were inhibited by RP 59500 at 0.25 to 1.0 microg/ml . The bactericidal activity of RP 59500 was markedly influenced by the erythromycin susceptibility of the strains and by several technical factors, such as inoculum growth phase and time of incubation of counting plates . As determined by time-kill methods, RP 59500 at a concentration of 2 or 8 microg/ml failed to kill erythromycin-resistant organisms under any conditions . Bactericidal activity was observed against all seven erythromycin-intermediate isolates when log-phase inocula were used and the cells were counted after 48 h of incubation (mean reductions in viable bacteria for RP 59500 at concentrations of 2 and 8 microg/ml, 3.45 and 3.50 log10 CFU/ml, respectively), but killing was diminished when the plates were examined at 72 h (mean killing, 3.06 and 2.95 log10, CFU/ml, respectively) . No bactericidal activity was observed when stationary-phase cultures were used . On the basis of these data, we expect that bactericidal activity of RP 59500 against the multiple-drug-resistant E . faecium strains currently encountered would be distinctly uncommon.

Clin J Oncol Nurs, 1997 Jul, 1(3), 73 - 7
Vancomycin-resistant enterococcus; Warnick F; Vancomycin-resistant enterococcus (VRE) rapidly is becoming a significant cause of nosocomial infections . VRE lives in the environment (e.g., bedside tables, side rails, door knobs) for five to seven days, making transmission difficult to eliminate . Patients who are immunosuppressed or are receiving multiple antibiotics are particularly susceptible to developing VRE infections . Nursing management is the cornerstone of prevention and treatment . Nurses need to identify patients at risk, maintain isolation, and educate patients, family members, and other healthcare team members.

Liver Transpl Surg, 1997 Nov, 3(6), 586 - 90
An outbreak of vancomycin-resistant Enterococcus faecium in liver transplant recipients; Dominguez EA et al.; Vancomycin-resistant Enterococcus faecium (VREF) has become a significant nosocomial pathogen for immunosuppressed patients . During a 5-month period in 1993, 8 cases of invasive infection with VREF (7 with bacteremia) were identified in liver transplant recipients, half of whom were adults . Epidemiology and microbiology studies were designed to identify the source and to determine the risk factors for this infection . Overall mortality was 50% (3 adults and 1 child) . Mortality in bacteremic patients was 57% . A case-control study showed that cases were more likely to have been treated with a third-generation cephalosporin or vancomycin and to have undergone more than four biliary tract procedures . Environmental surveillance cultures yielded only one VREF isolate from a rectal temperature probe, but this device was used in only 2 of the cases . Cultures from all surgery and radiology suites were negative . All VREF isolates were genotyped by contour-clamped homogenous electric field electrophoresis of chromosomal DNA restriction fragments . These studies showed that a single clone was responsible for the outbreak, although other clones could be detected in the hospital . After implementing strict contact isolation on the liver transplant unit, only 1 additional patient with VREF was identified during this outbreak . In conclusion, it was found that antibiotic use and biliary tract manipulation were risk factors for developing invasive infections with VREF after liver transplantation . Optimal treatment is still unclear but most likely includes a combination of two or more antibiotics . Prompt institution of infection control measures can preclude rapid spread of this nosocomial pathogen.

Liver Transpl Surg, 1997 Nov, 3(6), 563 - 70
Infectious complications after OKT3 induction in liver transplantation; Whiting JF et al.; The present study examines the incidence, risk factors, bacteriology, and mortality of infectious episodes and the role of antimicrobial prophylactic regimens after OKT3 induction in liver transplantation . Infections occurring in the first 6 months were evaluated according to the Centers for Disease Control criteria in 102 transplant recipients . Patients were administered OKT3 for 5 to 10 days, beginning intraoperatively, azathioprine, low-dose prednisone, and delayed introduction of cyclosporine . There were 140 major and 30 minor infections for an incidence of 1.7 infections per patient . Twenty-seven patients (26%) had no infectious episodes during the 6 months of follow-up . Bacterial and fungal infections peaked during the first month posttransplantation, whereas viral infections peaked during the second month . Infection-related mortality was 10% . One-year survival rate of patients who suffered a major infection was less than those who were infection free, but the difference was not statistically significant (79% vs . 89%; P = .61) . There was a significantly higher incidence of enterococcal infections under cefotetan prophylaxis than under ampicillin-sulbactam (.375 vs . 11 infections per patient; P = .0017) . There were 14 episodes of cytomegalovirus disease (14%) but no cytomegalovirus-related mortality or graft loss, and all cases responded to ganciclovir treatment . Bivariate and multivariate analyses identified only retransplantation as a risk factor for infection . In conclusion, OKT3 induction after liver transplantation is associated with a manageable incidence of bacterial, viral, or fungal infections . This is caused by, at least in part, improved anti-infective prophylaxis.

Arch Surg, 1997 Dec, 132(12), 1294 - 302
A randomized, double-blind clinical trial comparing cefepime plus metronidazole with imipenem-cilastatin in the treatment of complicated intra-abdominal infections . Cefepime Intra-abdominal Infection Study Group; Barie PS et al.; OBJECTIVE: To evaluate the safety and efficacy of cefepime hydrochloride plus metronidazole vs the combination of imipenem and cilastatin sodium in the treatment of complicated intra-abdominal infections in adult patients . DESIGN: Prospective, randomized, double-blind multicenter study . SETTING: University-affiliated hospitals in the United States and Canada . PATIENTS: Three hundred twenty-three patients with complicated intra-abdominal infections in whom an operative procedure or percutaneous drainage was required for diagnosis and management . INTERVENTION: Cefepime, 2 g, was administered intravenously every 12 hours (n= 164) in addition to metronidazole, 500 mg (or 7.5 mg/kg) intravenously every 6 hours . Imipenen-cilastatin sodium, 500 mg, was administered intravenously every 6 hours (n= 159) . Surgical infection management was determined by the patients' surgeons . MAIN OUTCOME ASSESSMENTS: Clinical cure, defined as elimination of all signs and symptoms relevant to the original infection; and treatment failure, defined as persistence, increase or worsening of signs and symptoms resulting in an antibiotic change, requirement of an additional surgical procedure to cure the infection, or a wound infection with fever . RESULTS: Of the initial isolates, 84% were susceptible to cefepime and 92% were susceptible to imipenem-cilastatin . Among the 217 protocol-valid patients, those treated with cefepime+metronidizole were deemed clinical cures (88%) more frequently than were imipenem-cilastatin-treated patients (76%) (P=.02) . Using multivariate analysis to adjust for identified clinical risk factors for an adverse outcome (severity of presenting illness, isolation of enterococcus, type of infection, and duration of prestudy hospitalization), there was a trend (P=.06) toward a higher cure rate favoring cefepime+metronidazole . Pathogens were eradicated in significantly (P=.01) more patients treated with combined cefepime and metronidazole (89%) than with imipenem-cilastatin (76%) . CONCLUSION: The combination of cefepime plus metronidazole is safe and effective therapy for patients with severe intra-abdominal infections.

Diagn Microbiol Infect Dis, 1997 Nov, 29(3), 203 - 5
In vitro activity of chloramphenicol alone and in combination with vancomycin, ampicillin, or RP 59500 (quinupristin/dalfopristin) against vancomycin-resistant enterococci; Messick CR et al.; Using a checkerboard assay, ampicillin, vancomycin, and RP 59500, each in combination with chloramphenicol, were tested for synergy against 23 isolates of vancomycin-resistant enterococci . Additive effects were seen in 62.5% of the isolates when exposed to chloramphenicol plus RP 59500 . Additive effects were observed in 20% and 15% of isolates with chloramphenicol plus vancomycin or ampicillin, respectively . No antagonism was noted.

J Clin Microbiol, 1997 Dec, 35(12), 3166 - 70
Clinical and epidemiological significance of enterococci intrinsically resistant to vancomycin (possessing the vanC genotype)
Toye B, Shymanski J, Bobrowska M, Woods W, Ramotar K.
Constitutive low-level vancomycin resistance is found intrinsically in certain enterococcal species and is encoded by vanC ligase genes . These intrinsically vancomycin-resistant enterococci (VRE) will be referred to as VANC VRE . A prospective study to determine the clinical and epidemiologic significance of VANC VRE was conducted . VANC VRE were recovered from the stools of 34 of 601 (5.7%) patients, a rate similar to that obtained for the stools of 100 outpatients in the community (5%) . VANC VRE were also isolated from the nonstool specimens of 9 of 538 patients (1.7%), including two patients with bacteremia . No VRE of the vanA or vanB genotypes were detected in nonstool specimens . Eighty-two hospital contacts of the first 23 patients found to be colonized or infected with VANC VRE were screened, and 6 contacts were found to be gastrointestinal carriers of VANC VRE . However, typing of isolates from these 6 contacts by pulsed-field gel electrophoresis with SmaI showed the isolates to be unique and different from those recovered from the index patients . In fact, all VANC VRE isolates from different patients in this study were unique . A case-control study with patients who were negative when screened for VANC VRE as controls failed to identify any risk factor associated with colonization or infection with this organism . VANC VRE were infrequently recovered from clinical specimens but were occasionally found as part of the normal stool flora . Since no transmission between patients was documented, additional isolation procedures may not be necessary for patients colonized or infected with VANC VRE.

Infect Control Hosp Epidemiol, 1997 Nov, 18(11), 771 - 3
Epidemiological study of hospital-acquired infection with vancomycin-resistant Enterococcus faecium: possible transmission by an electronic ear-probe thermometer; Porwancher R et al.; Clonal spread of vancomycin-resistant Enterococcus faecium among seven patients on one ward of a community teaching hospital was identified by contour-clamped homogeneous electric-field gel electrophoresis . Environmental cultures isolated the same strain from the handle of a shared electronic ear-probe thermometer . Cross-contamination of the clonal strain between two geographically separate units on this ward, sharing equipment but not personnel, suggests the possibility of an environmental source.

Infect Control Hosp Epidemiol, 1997 Nov, 18(11), 767 - 9
Prescribing pattern of vancomycin in a community teaching hospital with low prevalence of vancomycin-resistant enterococci; Watanakunakorn C; A 1-month prospective survey of all inpatients given vancomycin was performed in a community teaching hospital with a low prevalence of vancomycin-resistant enterococci . Only 20 of the 97 vancomycin orders written from August 1 to September 1, 1996, were consistent with Hospital Infection Control Practices Advisory Committee (HICPAC) guidelines . Surgical prophylaxis accounted for 37 of the 77 orders inconsistent with HICPAC guidelines.

Antimicrob Agents Chemother, 1997 Nov, 41(11), 2573 - 5
In vitro activities of an investigational quinolone, glycylcycline, glycopeptide, streptogramin, and oxazolidinone tested alone and in combinations against vancomycin-resistant Enterococcus faecium; Mercier RC et al.; We evaluated the in vitro activities of clinafloxacin, CL331,002, LY333328, quinupristin dalfopristin, and eperezolid (formerly known as U-100,592) against four strains of enterococci . All regimens tested resulted in the growth inhibition of each isolate . Against the three clinafloxacin-susceptible strains, clinafloxacin tested alone was the most active treatment, decreasing the bacterial inoculum by more than 3 log10 CFU/ml after 24 h in time-kill curve studies.

Diagn Microbiol Infect Dis, 1997 Oct, 29(2), 107 - 9
Study to determine the ability of clinical laboratories to detect antimicrobial-resistant Enterococcus spp . in Buenos Aires, Argentina; Cookson ST et al.; Few reports of vancomycin-resistant enterococci have appeared outside the USA . Therefore, we evaluated the ability of five laboratories in Buenos Aires, Argentina, to perform susceptibility testing using the disk diffusion method . Laboratories had difficulty identifying the low- and intermediate-level vancomycin-resistant phenotypes . This suggests that the disk diffusion method used by laboratories abroad may fail to detect some vancomycin-resistant enterococci.

J Hosp Infect, 1997 Oct, 37(2), 157 - 64
Chlorhexidine gluconate (CHG) activity against clinical isolates of vancomycin-resistant Enterococcus faecium (VREF) and the effects of moisturizing agents on CHG residue accumulation on the skin; Frantz SW et al.; The effectiveness of skin decontamination by chlorhexidine gluconate (CHG) in the presence of commonly-used skin moisturizing lotions was evaluated using vancomycin-resistant Enterococcus faecium (VREF) as a representative nosocomial pathogen . Anti-bacterial efficacy was determined in vitro using pigskin preparations inoculated with five VREF clinical isolates to evaluate Calgon Vestal 2 and 4% (by weight) CHG solutions in comparison with Hibiclens Antiseptic Antimicrobial Cleaner (4% CHG solution) . Control inocula were determined for each experiment from recovery of VREF harvested directly from the surface of each control piece of skin . These CHG formulations were evaluated in the presence and absence of Calgon Vestal 'Lotion Soft Skin Conditioner' (LSSC) to determine potential interactions of CHG with LSSC, and also with inverted question markVaseline Intensive Care' lotion as a CHG-deactivating agent . The 2% Calgon Vestal CHG alone reduced VREF 10(2)-10(3)-fold, as well as 10(3)-10(4)-fold when LSSC was present, and was as efficacious as either 4% CHG solution when these were tested in the presence of LSSC . Four percent Calgon Vestal CHG produced reductions of 10(3)-10(5)-fold with or without LSSC present . Conversely, inverted question markHibiclens' showed similar reductions in the presence of LSSC to that for the Calgon Vestal 4% CHG, but only a 10(1)-10(3)-fold reduction without LSSC . inverted question markVaseline Intensive Care' lotion completely inactivated the VREF-killing effects for all of the CHG formulations tested, while LSSC and inverted question markVaseline Intensive Care' lotion both showed minimal activity alone against these VREF isolates . These results indicate that the Calgon Vestal 2% CHG solution is as effective against VREF, even in the presence of LSSC, as either the 4% Calgon Vestal or Hibiclens 4% CHG formulations; the use of this lower concentration of CHG may be associated with less irritation, particularly with concomitant use of LSSC.

J Clin Microbiol, 1997 Nov, 35(11), 2966 - 8
Strains of glycopeptide-resistant Enterococcus faecium can alter their van genotypes during an outbreak; Woodford N et al.; Two isolates of Enterococcus faecium with VanA glycopeptide resistance were isolated during a hospital outbreak of E . faecium with plasmid-mediated VanB resistance . Both were found to be identical to the VanB outbreak strain by pulsed-field gel electrophoresis . The genotype of this strain changed from vanB to vanA through an intermediate isolate that contained both the vanA and vanB gene clusters on distinct plasmids.

FEMS Microbiol Lett, 1997 Oct 1, 155(1), 55 - 61
Arrangement of the vanA gene cluster in enterococci of different ecological origin; Werner G et al.; Glycopeptide-resistant enterococci (vanA) isolated from infections in humans, from non-hospitalized humans, from sewage, from animal feces and from meat products in Germany (20 Enterococcus faecium and one Enterococcus hirae) were investigated for the arrangement of the genes in the vanA gene cluster by means of overlapping PCR with five primer pairs . In 20 of these strains, the vanA gene clusters were uniform which suggests a horizontal spread among different ecosystems . In one clinical isolate a rearrangement was detected in the vanY-vanZ region.

Eur J Clin Microbiol Infect Dis, 1997 Aug, 16(8), 594 - 8
Enterococcus cecorum septicemia in a malnourished adult patient; Greub G et al.; Enterococcus cecorum, a species typically isolated from chicken, pigs, calves, horses, ducks, cats, dogs, and canaries, was isolated from the blood of a patient with severe septicemia . The isolate was identified by conventional biochemical tests . Identity as Enterococcus cecorum was confirmed by SDS-PAGE analysis of whole cell protein . This is the first report of the isolation of Enterococcus cecorum in a clinical setting.

Am J Infect Control, 1997 Oct, 25(5), 377 - 80
Microbiologic evaluation of needleless and needle-access devices; Arduino MJ et al.; OBJECTIVE: This study was carried out to determine whether needleless intravenous access devices are more likely to allow microorganisms to enter the fluid pathway than intravenous needle-access devices . METHODS: A laboratory study was conducted with two needleless and one intravenous needle-access devices and Enterococcus faecium as a bacterial challenge . Inocula of E . faecium were prepared on the basis of the numerical estimates of 1000 to 10,000 colony-forming units (CFU)/cm2 of bacterial flora on dry regions of skin (arms, legs, and hands) . The septum of each access device was inoculated with 10 to 20 microliters of a 10(4) to 10(5) CFU/ml challenge suspension, which was allowed to dry on the surface of the septum . In the first part of the experiment, the needleless or needle-access cannula of each device was used to puncture the corresponding septum without previously disinfecting the top of the septum . In the second part, the contaminated septum was punctured after disinfecting the septum with a 70% isopropyl alcohol wipe . After each puncture, trypticase soy broth was flushed through the fluid pathway of the intravenous access device, collected, and cultured by the membrane filtration technique . The septum of each injection-site cap and the needleless or needle-access cannula were sampled with sterile premoistened swabs . Swabs were cultured on blood agar plates . RESULTS: The rate of fluid pathway contamination was 100% (40/40) for one of the needleless intravenous access devices and 80% (20/25) for the other when septa were contaminated with E . faecium and not disinfected before puncture . The rate for the intravenous needle-access device was 72% (18/25) . When the septa of the three different devices tested were disinfected with 70% isopropyl alcohol, E . faecium was isolated on only one septum from all devices tested in part two (1/74, 1.3%) . CONCLUSIONS: These laboratory studies demonstrate that there is no statistically significant difference in the rate of fluid pathway contamination between needleless and intravenous needle-access devices . However, if the septa of either needleless or needle systems are not disinfected before puncture, a high rate of fluid pathway contamination may occur.

J Antimicrob Chemother, 1997 Sep, 40(3), 449 - 52
Teicoplanin in the treatment of enterococcal endocarditis: clinical and microbiological study; Venditti M et al.; Seven cases of enterococcal endocarditis treated with teicoplanin (7-10 mg/kg/day for 28-105 days) alone (one case) or in combination with aminoglycosides (six cases) were reviewed . All patients were cured . Serum bactericidal activity titres after intravenous gentamicin (5 mg/kg every 24 h) and teicoplanin (10 mg/kg every 24 h) were measured on day 7 of treatment in four patients against five enterococcal isolates: mean titres were 1:54 (range 1:16-64) and 1:22 (1:8-32) at 0.5 and 24 h post-infusion, respectively . Time-kill studies showed synergy between teicoplanin and gentamicin against three isolates . We conclude that single daily-dose teicoplanin/gentamicin combined therapy may represent a rational alternative to standard penicillin/gentamicin therapy and a useful regimen for home treatment of selected cases of enterococcal endocarditis.

J Antimicrob Chemother, 1997 Sep, 40(3), 377 - 82
Molecular genetic analysis of high-level gentamicin resistance in Enterococcus hirae; Mangan MW et al.; High-level resistance to gentamicin was studied in seven clinical isolates of Enterococcus hirae . In common with other members of the genus Enterococcus, such resistance in E . hirae was associated with single, large, conjugative plasmids . Molecular genetic analysis revealed five distinct plasmid types amongst the seven isolates . The determinant mediating high-level gentamicin resistance in E . hirae was also shown to be homologous to that already characterized for other enterococcal species.

Antimicrob Agents Chemother, 1997 Sep, 41(9), 2016 - 8
VanD-type glycopeptide-resistant Enterococcus faecium BM4339; Perichon B et al.; Enterococcus faecium BM4339 was constitutively resistant to vancomycin (MIC, 64 microg/ml) and to low levels of teicoplanin (MIC, 4 microg/ml) . A 605-bp product obtained with the V1 and V2 primers for amplification of genes encoding D-Ala:D-Ala ligases and related glycopeptide resistance proteins was sequenced after cloning . The deduced amino acid sequence had 69% identity with VanA and VanB and 43% identity with VanC, consistent with the finding that BM4339 synthesized peptidoglycan precursors terminating in D-lactate . This new type of glycopeptide resistance phenotype was designated VanD.

J Antimicrob Chemother, 1997 Aug, 40(2), 161 - 70
Management of infections due to resistant enterococci: a review of therapeutic options; Landman D et al.; The incidence of nosocomial enterococcal infection has increased steadily over the past two decades . The treatment of patients with enterococcal infection has been complicated by the emergence of strains possessing high level resistance to aminoglycosides, penicillins and, most recently, glycopeptides . Several recent studies have evaluated alternative antimicrobial agents for use against strains resistant to some or all standard agents . In this report, we review the therapeutic options for the management of antibiotic-resistant enterococcal infection.

Ann Pharmacother, 1997 Sep, 31(9), 970 - 3
Impact of a vancomycin restriction policy on use and cost of vancomycin and incidence of vancomycin-resistant Enterococcus; Morgan AS et al.; OBJECTIVE: To review the appropriateness of vancomycin therapy, changes in vancomycin use, and the incidence of vancomycin-resistant Enterococcus (VRE) after implementation of a limited restriction policy requiring approval from the Infectious Diseases Approval service to continue vancomycin therapy beyond 72 hours . DESIGN: A prospective chart review was conducted in April 1995 . Pharmacy billing data and infection control data were compared before and after policy implementation . SETTING: A 725-bed university teaching institution . PATIENTS: All patients receiving vancomycin during April 1995 . MAIN OUTCOME MEASURES: Appropriateness of use was based on the Centers for Disease Control and Prevention (CDC) recommendations for prudent vancomycin use . RESULTS: A total of 333 courses of vancomycin therapy were reviewed . Vancomycin use was appropriate in 219 (66%) courses . Of the 114 courses that did not meet the CDC guidelines, 76 (67%) were for empiric use, 35 (31%) were for prophylactic use, and 3 (3%) were for therapeutic use . Overall, the total number of grams used decreased 9%, grams per 1000 patient-days decreased by 10, and the total number of patients exposed to vancomycin decreased 0.5% . Several services had large decreases in vancomycin use . Vancomycin expenditures decreased by $15788 for the 7-month time period . The incidence of VRE remained unchanged, at 30% of all enterococcal isolates 2 years after policy implementation . CONCLUSIONS: The limited restriction policy was effective in decreasing the total grams of vancomycin used . However, one-third of vancomycin therapy was inappropriate and the incidence of VRE was unchanged . A more stringent restriction policy could potentially increase appropriate use, further decrease the amount of vancomycin used, and decrease the incidence of VRE.

Pathol Biol (Paris), 1997 May, 45(5), 430 - 2
{Bactericidal activity of quinolones (including sparfloxacin) against Enterococcus; in vitro antagonisms with gentamicin}; Watine J et al.; We selected 20 clinical Enterococcus isolates in order to represent the different types of amoxicillin and/or gentamicin-resistance present in our hospital . Bacteriostatic and bactericidal activities of amoxicillin, pefloxacin, ofloxacin, ciprofloxacin, sparfloxacin, vancomycin, alone or associated with gentamicin, were evaluated on those 20 isolates . Sparfloxacin or ciprofloxacin were more frequently bacteriostatic and/or bactericidal than pefloxacin or ofloxacin . The effect of quinolones and gentamicin in combination use was not only synergistic but antagonistic, which is not in agreement with others' results.

J Bacteriol, 1997 Sep, 179(18), 5903 - 13
Transcriptional regulation of the Enterococcus faecium BM4147 vancomycin resistance gene cluster by the VanS-VanR two-component regulatory system in Escherichia coli K-12; Haldimann A et al.; An Escherichia coli K-12 model system was developed for studying the VanS-VanR two-component regulatory system required for high-level inducible vancomycin resistance in Enterococcus faecium BM4147 . Our model system is based on the use of reporter strains with lacZ transcriptional and translational fusions to the PvanR or PvanH promoter of the vanRSHAX gene cluster . These strains also express vanR and vanS behind the native PvanR promoter, the arabinose-inducible ParaB promoter, or the rhamnose-inducible PrhaB promoter . Our reporter strains have the respective fusions stably recombined onto the chromosome in single copy, thereby avoiding aberrant regulatory effects that may occur with plasmid-bearing strains . They were constructed by using allele replacement methods or a conditionally replicative attP plasmid . Using these reporter strains, we demonstrated that (i) the response regulator VanR activates PvanH, but not PvanR, expression upon activation (phosphorylation) by the partner kinase VanS, the noncognate kinase PhoR, or acetyl phosphate, indicating that phospho-VanR (P-VanR) is a transcriptional activator; (ii) VanS interferes with activation of VanR by PhoR or acetyl phosphate, indicating that VanS also acts as a P-VanR phosphatase; and (iii) the conserved, phosphate-accepting histidine (H164) of VanS is required for activation (phosphorylation) of VanR but not for deactivation (dephosphorylation) of P-VanR . Similar reporter strains may be useful in new studies on these and other interactions of the VanS-VanR system (and other systems), screening for inhibitors of these interactions, and deciphering the molecular logic of the signal(s) responsible for activation of the VanS-VanR system in vivo . Advantages of using an E . coli model system for in vivo studies on VanS and VanR are also discussed.

Proc Natl Acad Sci U S A, 1997 Sep 16, 94(19), 10040 - 4
Bacterial resistance to vancomycin: overproduction, purification, and characterization of VanC2 from Enterococcus casseliflavus as a D-Ala-D-Ser ligase; Park IS et al.; The VanC phenotype for clinical resistance of enterococci to vancomycin is exhibited by Enterococcus gallinarum and Enterococcus casseliflavus . Based on the detection of the cell precursor UDP-N-acetylmuramic acid pentapeptide intermediate terminating in D-Ala-D-Ser instead of D-Ala-D-Ala, it has been predicted that the VanC ligase would be a D-Ala-D-Ser rather than a D-Ala-D-Ala ligase . Overproduction of the E . casseliflavus ATCC 25788 vanC2 gene in Escherichia coli and its purification to homogeneity allowed demonstration of ATP-dependent D-Ala-D-Ser ligase activity . The kcat/Km2 (Km2 = Km for D-Ser or C-terminal D-Ala) ratio for D-Ala-D-Ser/D-Ala-D-Ala dipeptide formation is 270/0.69 for a 400-fold selection against D-Ala in the C-terminal position . VanC2 also has substantial D-Ala-D-Asn ligase activity (kcat/Km2 = 74 mM-1min-1).

Rinsho Byori, 1997 Aug, 45(8), 795 - 800
{Transient hyperphosphatasemia observed in a boy with acute lymphoblastic leukemia}; Kikuchi S et al.; A detailed time course of alkaline phosphatase (ALP; EC3.1.3.1) activity of transient hyperphosphatasemia (TH) in a 9-year-old boy with acute lymphoblastic leukemia (ALL) is described . The patient's serum ALP activity rose transiently to 49 times the upper limit of normal adult, without any evidences of hepatic and bone disease . The half-life of ALP activity was calculated about 10 days . We characterized ALP isoenzymes by usual electrophoresis using cellulose acetate membrane (Titan III iso-vis) and polyacrylamide disc gel (AlkPhor), and isoelectric focusing using polyacrylamide slab gel . The former two methods showed typical two bands (fast-alpha 2 and alpha 2 beta bands) and the latter one method revealed more basic bands of liver and bone, suggesting the extensive sialylation . The patient complained fever and diarrhea . Enterococcus faecium was detected from his stool . Etiologically, two more patients in the same ward showed TH in the same period . It suggested TH would be occurred by infectious states . Awareness of such benign forms of hyperphosphatasemia not related to malignancy will aid the physician in the differential diagnosis of elevated ALP activity.

Microbiology, 1997 Aug, 143 ( Pt 8), 2639 - 46
The form of folate affects the mechanisms of methotrexate resistance in Enterococcus hirae {corrected}; Tamura T et al.; Several mechanisms have been described to explain the resistance of cells to methotrexate (MTX); however, the basis for the heterogeneity of mechanisms has been obscure . It was hypothesized that the type of MTX resistance in a single species can be influenced by the form of extracellular folate supplied during the development of resistance . Two strains of MTX-resistant Enterococcus hirae {corrected} were developed by transferring the bacteria to media containing increasing concentrations of MTX in the presence of constant concentrations of either 5-formyl-5,6,7,8-tetrahydropteroylglutamic acid (5-HCO-H4PteGlu) or pteroylglutamic acid (PteGlu) . These resistant strains were designated E . hirae/MTX/5-HCO-H4PteGlu and E . hirae/MTX/PteGlu, respectively {corrected} . The mechanisms of MTX resistance included: (1) increased folic acid reductase (FAR) activity in both resistant strains but increased dihydrofolate reductase (DHFR) activity only in E . hirae/MTX/PteGlu {corrected}; (2) decreased synthesis and intracellular retention of MTX containing two glutamyl residues; (3) decreased uptake of MTX accompanied by decreased uptake of folates; and (4) reduction of folate-binding capacity . Among these, the form of folate present in the media during the development of resistance affected DHFR and FAR activities and the transport of folates . These findings, together with data from other laboratories, suggest that it may be important to use a reduced form of folate, a more physiological form than oxidized PteGlu, in the media during the development of resistance for the study of the mechanisms of MTX resistance in cultured cells.

Pathology, 1997 Aug, 29(3), 303 - 4
Increasing vancomycin resistance in Enterococcus spp . in Australia: facing the challenge in the laboratory; Anderson M et al.; High level vancomycin resistance in enterococci (VRE) is increasing in Australia . If the spread of VRE is to be checked, then it is vital for laboratories to be able to detect it promptly and accurately . We have established a rapid and accurate screening method using Enterococcosel agar supplemented with 6 mg/l vancomycin . It can recover VRE from spiked feces, it may be used to screen feces for carriage of VRE and it is not subject to the confounding effects which feces introduce to broth enrichment culture.

J Hosp Infect, 1997 Aug, 36(4), 249 - 59
Gene transfer, gentamicin resistance and enterococci; Simjee S et al.; Enterococci are versatile pathogens by virtue of their ability to exhibit low-level intrinsic resistance to clinically useful antibiotics and their tolerance to adverse environmental conditions . In the last 20 years these pathogens have become progressively more difficult to treat because of their aptitude for acquiring antibiotic-resistance genes . Of increasing concern is the rapid dissemination of the AAC6'-APH2" bi-functional aminoglycoside modifying enzyme . This enzyme confers high-level resistance to gentamicin and all other related aminoglycosides with the exception of streptomycin . The gene conferring this phenotype has been associated with both narrow and broad host range plasmids, and has recently been found on conjugative transposons . The nature of these conjugative elements raises the possibility of the resistance gene spreading to other pathogenic bacteria.

Antimicrob Agents Chemother, 1997 Aug, 41(8), 1805 - 7
Identification and characterization of IS1476, an insertion sequence-like element that disrupts VanY function in a vancomycin-resistant Enterococcus faecium strain; MacKinnon MG et al.; The vanY gene of vancomycin-resistant enterococci encodes a D,D-carboxypeptidase . By using a PCR detection strategy, a VanA Enterococcus faecium clinical isolate was found to have an insertion sequence (IS)-like element designated IS1476 in vanY . The activity of the VanY D,D-carboxypeptidase in this isolate was decreased in a fluorometric fluoraldehyde o-phthalaldehyde assay with diacetyl-L-Lys-D-Ala-D-Ala as the substrate . This, to our knowledge, is the first report of an IS-like element in a vancomycin resistance gene.

Biochemistry, 1997 Jul 15, 36(28), 8611 - 8
13C NMR analysis of the cysteine-sulfenic acid redox center of enterococcal NADH peroxidase; Crane EJ 3rd et al.; In order to characterize the native Cys42-sulfenic acid redox center of the flavoprotein NADH peroxidase by NMR, an expression protocol has been developed which yields the {3-13C}Cys42-labeled protein in 100 mg quantities . Difference spectra of the labeled minus unlabeled oxidized enzyme (E) give a peak at 41.3 ppm (relative to dioxane) which represents the Cys42-sulfenic acid . Reduction of labeled E with 1 equiv of NADH gives the air-stable two-electron reduced (EH2) species, and oxidized minus reduced difference spectra give maxima and minima at 41.3 and 30.8 ppm, respectively, corresponding to the Cys42-sulfenic acid and -thiolate species . Peroxide inactivation of E, which has previously been attributed to oxidation of the Cys42-sulfenic acid to the Cys42-sulfinic and/or sulfonic acid states, gives rise to a new maximum in the difference spectrum of Einactive minus E at 57.0 ppm . A similar expression protocol was used to obtain the {ring-2-13C}His-labeled peroxidase HHAA mutant (His10His23Ala87Ala258); the spectral change over the pH range 5.8-7 . 8 is attributed to deprotonation of the surface-exposed His23 . Furthermore, replacement of Arg303, which is hydrogen bonded to His10, has no effect on the 13C spectrum . These results provide direct evidence in support of the peroxidase Cys42-sulfenic acid/thiol redox cycle and add significantly to our structure-based understanding of protein-sulfenic acid stabilization and function.

Emerg Infect Dis, 1997 Jul-Sep, 3(3), 311 - 7
Vancomycin-resistant enterococci outside the health-care setting: prevalence, sources, and public health implications; McDonald LC et al.; Although nosocomial acquisition and subsequent colonization of vancomycin-resistant enterococci (VRE), an emerging international threat to public health, has been emphasized in the United States, colonization among nonhospitalized persons has been infrequently documented . In contrast, in Europe, colonization appears to occur frequently in persons outside the health-care setting . An important factor associated with VRE in the community in Europe has been avoparcin, a glycopeptide antimicrobial drug used for years in many European nations at subtherapeutic doses as a growth promoter in food-producing animals . In Europe, evidence suggests that foodborne VRE may cause human colonization . Although avoparcin has never been approved for use in the United States, undetected community VRE transmission may be occurring at low levels . Further studies of community transmission of VRE in the United States are urgently needed . If transmission with VRE from unrecognized community sources can be identified and controlled, increased incidence of colonization and infection among hospitalized patients may be prevented.

J Infect, 1997 Jul, 35(1), 77 - 8
Isolation of Enterococcus avium from bile and blood in a patient with acute cholecystitis; Verhaegen J et al.; The isolation of Enterococcus avium from bile fluid and blood of an uncompromised patient with acute cholecystitis is reported . As advanced identification of Enterococcus sp . by biochemical and physiological tests is not routinely done, the occurrence of E . avium infections may be underestimated.

New Microbiol, 1997 Jul, 20(3), 221 - 5
Synergy and mechanism of interaction between pefloxacin and penicillin G against enterococci; Grossato A et al.; In vitro synergy between penicillin and pefloxacin against Enterococcus hirae and Enterococcus faecium strains with different penicillin susceptibility was studied . The combination was synergistic against penicillin-resistant strains . E . hirae R40 and E . faecium 28R, but not against the penicillin-susceptible ones (E . hirae ATCC 9790 and E . faecium 28S) . Analysis of PBPs of cells, grown in the presence of pefloxacin, showed that PBP5 of penicillin-resistant strains, the PBP responsible for the resistance of enterococci to beta-lactam antibiotics, is consistently reduced while it is almost unaffected in the penicillin-susceptible strains even at the highest concentrations of pefloxacin . These results indicate that pefloxacin interferes with the mechanism of synthesis of PBPs and particularly of PBP5, a protein whose production has already been modified in resistant strains, in some way rectifying the previous alteration.

J Appl Microbiol, 1997 Jul, 83(1), 120 - 6
Enumeration of Enterococcus sp . using a modified mE method; Rhodes MW et al.; A modified mE medium (mEI) containing the chromogenic substrate indoxyl-beta-D-glucoside to detect beta-D-glucosidase activity was evaluated with respect to specificity and recovery of enterococci from environmental waters . Extending incubation from 24 to 48 h improved enterococci recovery but 77% of the colonies classified as non-target were confirmed as enterococci . Randomly chosen enterococcal isolates from sewage, exposed in microcosms containing 0.22 micron membrane filtered fresh or estuarine water, exhibited differences in persistence as a function of exposure treatment . Decreasing the concentration of or eliminating indoxyl-beta-D-glucoside from mE did not significantly affect recovery of purified isolates.

J Lab Clin Med, 1997 Jul, 130(1), 14 - 20
Vancomycin-resistant enterococci: clinical, microbiologic, and epidemiologic features; Noskin GA; Enterococci have emerged as important nosocomial pathogens with increasing antimicrobial resistance . Within the past 5 years, vancomycin-resistant strains have disseminated throughout the United States and Europe . Many of these organisms are also highly resistant to beta-lactams and aminoglycosides, making them virtually untreatable . Because optimal therapy for these infections is unknown, attributable mortality rates for patients with vancomycin-resistant enterococcal bacteremia are extremely high . Recently identified risk factors for acquisition include prolonged hospitalization, prior antibiotic use, and serious underlying illness . Until effective therapy is available, prevention of infection by proper infection control procedures and judicious antibiotic use is critical.

Prev Vet Med, 1997 Jul, 31(1-2), 95 - 112
Avoparcin used as a growth promoter is associated with the occurrence of vancomycin-resistant Enterococcus faecium on Danish poultry and pig farms; Bager F et al.; We determined the association between the use of the glycopeptide antibiotic avoparcin as a growth promoter and the occurrence of Enterococcus faecium (VREF) with high-level resistance to vancomycin (MIC > or = 64 micrograms ml-1) on poultry and pig farms . The investigations were conducted as retrospective cohort studies, where groups of farms exposed or not exposed to avoparcin between September 1994 and April 1995 were compared . In poultry, the association between the use of avoparcin and the occurrence of VREF was confounded by the use of broad-spectrum antibiotics, and the adjusted relative risk was 2.9 (1.4-5.9) . In pigs, the association had a similar magnitude with a non-adjusted relative risk of 3.3 (0.9-12.3) . The similar findings in the two studies provide evidence in favour of a causal association between the use of avoparcin and the occurrence of VREF on farms, and suggest that food animals constitute a potential reservoir of infection for VREF in humans.

Proc Natl Acad Sci U S A, 1997 Jun 10, 94(12), 6480 - 3
D-Ala-D-Ala ligases from glycopeptide antibiotic-producing organisms are highly homologous to the enterococcal vancomycin-resistance ligases VanA and VanB; Marshall CG et al.; The crisis in antibiotic resistance has resulted in an increasing fear of the emergence of untreatable organisms . Resistance to the glycopeptide antibiotic vancomycin in the enterococci, and the spread of these pathogens throughout the environment, has shown that this scenario is a matter of fact rather than fiction . The basis for vancomycin resistance is the manufacture of the depsipeptide D-Ala-D-lactate, which is incorporated into the peptidoglycan cell wall in place of the vancomycin target D-Ala-D-Ala . Pivotal to the resistance mechanism is the production of a D-Ala-D-Ala ligase capable of ester formation . Two highly efficient depsipeptide ligases have been cloned from vancomycin-resistant enterococci: VanA and VanB . These ligases show high amino acid sequence similarity to each other ( approximately 75%), but less so to other D-Ala-D-X ligases (<30%) . We have cloned ddls from two glycopeptide-producing organisms, the vancomycin producer Amycolatopsis orientalis and the A47934 producer Streptomyces toyocaensis . These ligases show strong predicted amino acid homology to VanA and VanB (>60%) but not to other D-Ala-D-X ligases (<35%) . The D-Ala-D-Ala ligase from S . toyocaensis shows D-Ala-D-lactate synthase activity in cell-free extracts of S . lividans transformed with the ddl gene and confirms the predicted enzymatic activity . These results imply a close evolutionary relationship between resistance mechanisms in the clinics and in drug-producing bacteria.

Prof Nurse, 1997 Jun, 12(9), 641 - 4
Vancomycin-resistant enterococci: implications for infection control; Molyneux R et al.; The incidence of vancomycin-resistant enterococci (VRE) infection is increasing . Immunosuppressed individuals are particularly vulnerable to infection with VRE . Strict attention to infection control measures is important in preventing the spread of multiresistant organisms.

Infect Dis Clin North Am, 1997 Jun, 11(2), 367 - 84
Vancomycin-resistant enterococcus . Detection, epidemiology, and control measures; Boyce JM; VRE have spread rapidly since their initial description in 1988 . Although much has been learned about the epidemiology of VRE, further studies are needed to establish the reservoirs of the organism and the relative importance of various modes of transmission . There is considerable anecdotal evidence that nosocomial transmission of VRE can be thwarted by using measures such as those recommended by HICPAC, especially if they are implemented promptly after VRE have been introduced into hospitals.

Am Surg, 1997 Jun, 63(6), 525 - 35
How many antibiotics are necessary to treat abdominal trauma victims?
Sims EH, Thadepalli H, Ganesan K, Mandal AK.
We wanted to determine the value of single-versus multiple-antibiotic treatment in cases of penetrating abdominal trauma . Of 357 patients entered into a prospective, randomized, examiner-blinded study, 291 met all protocol criteria; 101 of these patients received cefoperazone alone, 95 were given ceftriaxone with metronidazole, and 95 were placed on metronidazole, gentamicin, and ampicillin . Aerobic and anaerobic bacterial cultures were obtained upon opening and closing the peritoneum . The three groups were found to be similar upon evaluation of key parameters, such as the median number of febrile days, morbidity, incisional wound infection, intra-abdominal abscess, septicemia, other infections, hospital stay, and death . Fifteen of 291 (5%) patients had infectious complications, and 12 (4.1%) developed noninfectious complications . There were six (2.1%) deaths, two in each antibiotic group . Noninfectious complications occurred more frequently in the triple-antibiotic group, which was statistically significant (P = 0.013) . There were no therapeutic failures, and therefore, the routine usage of additional antibiotics to cover for enterococcus needs justification.

J Clin Microbiol, 1997 Jun, 35(6), 1565 - 70
Emergence and dissemination of a highly vancomycin-resistant vanA strain of Enterococcus faecium at a large teaching hospital; Pegues DA et al.; We prospectively identified patients at the Massachusetts General Hospital from whom vancomycin-resistant enterococci (VRE) were isolated from a clinical specimen from 1 January 1991 through 31 December 1995 . VRE strains were available from 139 (82%) of the 169 patients with clinical cases . Of these, 39 (28%) were identical or closely related by pulsed-field gel electrophoresis (i.e., VRE type A strain), including 38 (43%) of 89 VRE strains in 1995 . By multivariate analysis, acquisition of the VRE type A strain was associated with receipt of clindamycin (odds ratio {OR} = 10.5), 15 or more days of hospitalization before the first isolation of VRE (OR = 2.9), and residence on one of the general medical floors (OR = 7.8) . The VRE type A strain was a vanA strain of Enterococcus faecium and was highly resistant to all antimicrobial agents tested except chloramphenicol . These findings document the rapid dissemination of a highly resistant strain of E . faecium among patients and among other extant VRE strains at the Massachusetts General Hospital in 1995.

Arch Intern Med, 1997 May 26, 157(10), 1132 - 6
Effect of a vancomycin restriction policy on ordering practices during an outbreak of vancomycin-resistant Enterococcus faecium; Anglim AM et al.; BACKGROUND: With the development of nosocomial pathogens that are resistant to multiple antimicrobial agents, reasonable restriction of antibiotic use has become a priority . METHODS: During an outbreak of vancomycin-resistant enterococcal infections, an audit of vancomycin hydrochloride use was conducted during October 3 through 21, 1994, and January 24 through February 2, 1995 . During these periods, all orders for vancomycin were reviewed by clinical pharmacists . Use was classified as either appropriate or inappropriate based on recommendations by the Hospital Infection Control Practice Advisory Committee (HICPAC) of the Centers for Disease Control and Prevention, Atlanta, Ga . A policy restricting the use of vancomycin was adopted in November 1994 . RESULTS: During the first audit in October 1994, 61% of vancomycin orders were considered inappropriate according to HICPAC criteria . At the time of this audit, the first cases of an outbreak of nosocomial vancomycin-resistant Enterococcus faecium had been detected . The follow-up audit showed that 30% of vancomycin orders were inappropriate by HICPAC criteria (P < .001) . Overall use of vancomycin decreased by 50% and remained at this lower level for the following year . CONCLUSION: The institution of a vancomycin restriction policy was associated with a reduction of both inappropriate drug orders and total use.

Biochem Biophys Res Commun, 1997 May 19, 234(2), 341 - 5
The stabilizing residues and the functional domains in the hyperthermophilic V-ATPase of Desulfurococcus; Shibui H et al.; To clarify a universal mechanism of the intramolecular rotation of ATP-synthase, an operon encoding a stable, ancestral ATPase was cloned from a heterotrophic archaeum Desulfurococcus strain SY . The operon of about 7 kbp contained genes E, C, G, A, B and D encoding subunits with predicted molecular weights of 23,217, 41,659, 11,499, 65,476, 52,295, and 24,897, respectively . The sequence was compared with that of Na-ATPase of Enterococcus hirae, A-ATPase of Halobacterium salinarium, V-ATPase of Methanosarcina mazei, and ATP synthase of Methanococcus jannaschii, which are homologous . (1) The cause of hyperthermostability: The main exchanges in the amino acid residues of hyperthermophilic proteins included Asp --> Glu (11 residues of A subunit of E.h.) and, Ser --> Ala . (2) The domains needed for the intramolecular rotation: The domains similar to those established in F-type ATPases were also found in the V-type ATPases of species with a different energy metabolism.

Bioorg Khim, 1997 May, 23(5), 410 - 21
{Non-natural aglycones of glycopeptide antibiotics of the vancomycin group . Synthesis and antibacterial activity.}; Pavlov AIu et al.; A new approach for the modification of the heptapeptide core of glycopeptide antibiotics was proposed based on the replacement of amino acid residues in positions 1 and 3 in teicoplanin aglycone and in position 1 in the eremomycin aglycone . Six novel nonnatural aglycones of the vancomycin type were obtained . Compounds derived from the teicoplanin aglycone exhibited in vitro activity against Gram-positive bacteria, and two of them were also active against the vancomycin-resistant enterococci.

Arch Phys Med Rehabil, 1997 May, 78(5), 553 - 5
Controlling the spread of vancomycin-resistant enterococci with a rehabilitation cohort unit; Duerden ME et al.; Enterococci are common to the human gastrointestinal tract . Recently there has been an emergence of vancomycin-resistant enterococci (VRE); infection requires strict contact isolation . Patients with VRE infections are at higher risk for morbidity and mortality . As a result of the high prevalence of VRE, it was recommended that a cohort unit be established to control its spread within our metropolitan community hospital . We report the development of a rehabilitation VRE cohort unit . We present case studies of five patients who developed nosocomial colonization and one with an infection with VRE; all were treated on the rehabilitation cohort unit . Protocols for VRE isolation and procedures for decontamination in the cohort unit were developed . If a cohort unit is necessary, it is feasible to conduct a rehabilitation program in a cohort unit with strict adherence to contact isolation.

Nippon Rinsho, 1997 May, 55(5), 1206 - 12
{Regulation mechanism of glycopeptide resistance expression}; Ohno A et al.; The glycopeptide antibiotics have been used to treat severe infections caused by pathogenic Gram- positive bacteria since their discovery in the 1950s . However, resistance is now emerging and spreading among enterococci . The mechanism of resistance is the synthesis of a modified cell-wall precursor, terminating in D-lactate with a lower affinity for the glycopeptides . Three glycopeptide resistance phenotype (VanA, VanB and VanC) have been distinguished on the basis of the level and inducibility of the resistance to vancomycin and teicoplanin . Especially, most attention has been focused on VanA resistance because of a high-level resistance . VanA-resistance has been associated with five genes (vanR, vanS, vanH, vanA, vanX) on the transposon Tn 1546, which usually resides on a plasmid . Synthesis of VanH, VanA and VanX is regulated at the transcriptional level by the VanR-VanS two-component regulatory system . The VanH dehydrogenase and the VanA ligase, which is D-Ala-D-Ala ligase of altered substrates specificity, catalyze the synthesis of the depsipeptide D-alanyl-D-lactate . The VanX dipeptidase hydrolyzes the dipeptide D-alanyl-D-alanine produced by the host ligase.

Infect Control Hosp Epidemiol, 1997 May, 18(5), 345 - 7
Activity of disinfectants against vancomycin-resistant Enterococcus faecium; Saurina G et al.; Vancomycin-resistant enterococci (VRE) often contaminate the hospital environment . We examined the activity of commonly used disinfectants against eight strains of VRE, using a quantitative suspension test method . Isopropyl alcohol and sodium hypochlorite were highly effective . Hydrogen peroxide was ineffective for all strains . After 10 minutes of incubation (the manufactures' recommended time of exposure), three phenolic and three quaternary ammonium compounds also were highly effective . After 3 minutes of exposure, however, occasional failures did occur . With the exception of 3% hydrogen peroxide, most disinfectants appear to be active against VRE.

Infect Control Hosp Epidemiol, 1997 May, 18(5), 333 - 9
Colonization with vancomycin-resistant Enterococcus faecium: comparison of a long-term-care unit with an acute-care hospital; Bonilla HF et al.; OBJECTIVE: To compare the epidemiology of vancomycin-resistant Enterococcus faecium (VRE) in a long-term-care unit and an acute-care hospital . DESIGN: Point-prevalence surveys for VRE rectal colonization of patients were carried out over a 21-month period in patients in a long-term-care unit and an acute-care hospital (medical ward and intensive-care units) . The environment and hands of healthcare workers also were sampled for VRE . Contour-clamped homogeneous electric field (CHEF) electrophoresis was used to evaluate possible transmission among roommates and the relatedness of patient strains to those in the environment and on the hands of healthcare workers . SETTING: A 200-bed Veterans Affairs Medical Center with an attached 90-bed long-term-care unit . RESULTS: From December 1994 to January 1996, rectal VRE colonization of patients in the long-term-care unit increased significantly from 9% to 22% . In contrast, patients on the medical ward rarely were colonized after the first survey in December 1994, and only two intensive-care-unit patients were found to be colonized during the four surveys . The environment was contaminated persistently in the long-term-care unit . In the four surveys, carriage of VRE on hands of healthcare workers varied from 13% to 41%; 65% of healthcare workers with VRE found on their hands worked in the long-term-care unit . Seven different strains were identified by CHEF typing . Although the initial survey found only vanA strains, subsequent surveys showed vanB strains also were present . CONCLUSIONS: Residents of a long-term-care unit frequently were colonized with VRE, but infections were uncommon in this population . The environment of the long-term-care unit was contaminated with VRE, and VRE was found frequently on the hands of healthcare workers in this unit . Both vanA and vanB genotypes were found in this setting.

Antimicrob Agents Chemother, 1997 May, 41(5), 956 - 60
Overexpression and characterization of the chromosomal aminoglycoside 6'-N-acetyltransferase from Enterococcus faecium; Wright GD et al.; The chromosomal gene aac(6')-Ii, encoding an aminoglycoside 6'-N-acetyltransferase in Enterococcus faecium, renders this organism resistant to moderate levels of many aminoglycoside antibiotics . The ubiquitous presence of aac(6')-Ii in E . faecium complicates the selection of antibiotics for treatment of infections caused by this organism . In view of the importance of this enzyme, we have initiated studies to gain an understanding of its molecular mechanism of acetyl transfer . The AAC(6')-Ii enzyme was overexpressed in Escherichia coli and purified in a simple three-step procedure which yields 55 mg of pure dimeric protein per liter of cell culture . Steady-state kinetic analyses revealed a broad substrate specificity and demonstrated that acetylation occurs exclusively at position N-6' . k(cat)/Km values were on the order of 10(4) M(-1) s(-1), which is relatively low compared to other aminoglycoside-modifying enzymes . In addition, MIC values were positively correlated with k(cat), the rate when the enzyme is saturated with the aminoglycoside substrate, and not with k(cat)/Km, the rate at low aminoglycoside (sub-Km) concentrations . These results describe an enzyme which is not optimally evolved for aminoglycoside inactivation and suggest that this chromosomally encoded enzyme may have an alternate physiological function.

Antimicrob Agents Chemother, 1997 May, 41(5), 931 - 5
Influence of inducible cross-resistance to macrolides, lincosamides, and streptogramin B-type antibiotics in Enterococcus faecium on activity of quinupristin-dalfopristin in vitro and in rabbits with experimental endocarditis; Fantin B et al.; The influence of inducible cross-resistance to macrolides, lincosamides, and streptogramin B (MLS(B)) type antibiotics (inducible MLS(B) phenotype) on the activity of quinupristin-dalfopristin was investigated against Enterococcus faecium in vitro and in rabbits with experimental endocarditis . In vitro, quinupristin-dalfopristin displayed bacteriostatic and bactericidal activities against a MLS(B)-susceptible strain similar to those against two strains with the inducible MLS(B) phenotype . In addition, induction of the two MLS(B)-resistant strains with quinupristin (0.016 to 1 microg/ml) or quinupristin-dalfopristin (0.08 to 0.25 microg/ml) increased the MICs of quinupristin from 8 microg/ml to 32 to > 128 microg/ml, but did not modify the MIC of dalfopristin (2 microg/ml) or quinupristin-dalfopristin (0.5 microg/ml) . In a rabbit endocarditis model, quinupristin-dalfopristin was as active as amoxicillin against the MLS(B)-susceptible E . faecium strain . In contrast, the activity of quinupristin-dalfopristin was significantly decreased in animals infected with either of the two inducible MLS(B)-resistant strains (P < 0.05), although no mutants resistant to quinupristin-dalfopristin were detected . Against the clinical strain with the inducible MLS(B) phenotype, quinupristin-dalfopristin was not effective and was less active than amoxicillin (P < 0.001); however, the activity of the combination of amoxicillin and dalfopristin-quinupristin was superior to that of amoxicillin (P < 0.01) . The different impact of the inducible MLS(B) phenotype in E . faecium on the activity of quinupristin-dalfopristin in vitro and in experimental endocarditis may be related to the reduced diffusion of dalfopristin compared with that of quinupristin into cardiac vegetations that we previously reported . This result emphasizes the importance of the constant presence of dalfopristin at the site of infection to ensure synergism with quinupristin.

Clin Infect Dis, 1997 May, 24(5), 1001 - 3
Infectious complications of hepatic cryosurgery; Riley DK et al.; Hepatic cryosurgery is a novel procedure for patients with metastatic liver disease . To date, no reviews of the infectious complications of this procedure have been published . One hundred and fifty patients underwent 158 hepatic cryosurgical procedures at Allegheny General Hospital (Pittsburgh) from November 1987 through July 1995 . Gastrointestinal malignancies accounted for 93% of the underlying diagnoses . The following 12 infections were directly related to the cryosurgical procedure: hepatic abscess (six), intraperitoneal abscess (three), ascending cholangitis (two), and an intrahepatic device (Infusaid; Strato/Infusoid, Norwood, MA) infection (one) . Enterococcus was the most commonly isolated organism . Seven of the 12 infections were polymicrobial . The patients who developed infections had longer hospital stays (26 days vs . 13 days) and had more days of fever (6.5 days vs . 2.3 days) . than those who did not develop infections . If perioperative manipulation of the biliary tree is avoided, the infection rate in patients who undergo hepatic cryosurgery may be decreased even further . Overall, cryoablation of the liver is not related to an increased risk of infection.

J Clin Microbiol, 1997 May, 35(5), 1248 - 50
A PCR assay for identification of Enterococcus faecium; Cheng S et al.; Enterococcus faecium has recently emerged as a serious nosocomial pathogen . The prevalence and severity of enterococcal infections, the mortality rate from such infections, and the antibiotic resistance of enterococci are often species dependent . Since conventional biochemical methods fail to differentiate E . faecium from certain newly described enterococcal species, a PCR-based assay was developed for the rapid identification of E . faecium.

J Biol Chem, 1997 Apr 4, 272(14), 8932 - 6
CopY is a copper-inducible repressor of the Enterococcus hirae copper ATPases; Strausak D et al.; The cop operon of Enterococcus hirae effects copper homeostasis in this organism . It encodes a repressor, CopY, an activator, CopZ, and two P-type copper ATPases, CopA and CopB . Expression of all four genes is regulated by the ambient copper . In this regulation, CopY apparently acts as a copper-inducible repressor . By DNase I footprinting, it was shown that purified CopY protected two discrete sites in the region encompassing nucleotides -71 to -11 relative to the translational start site and containing hyphenated inverted repeats . Transcription is initiated between these repeats at nucleotide -42, in a domain that remained accessible to DNase I in the DNA-repressor complex . Chemical cross-linking revealed that CopY exists as a dimer in solution . In DNA band-shift assays, it was apparent that the CopY-DNA interaction occurred in two discrete steps . Half-maximal binding of repressor to the two operator sites was observed at 2 x 10(-9) M and 5 x 10(-9) M CopY, respectively . Copper ions released CopY from the promoter/operator with an apparent half-binding constant for Cu(I) of 20 microM . The site-directed mutations A-61T and A-30T essentially abolished the binding of CopY to the respective binding sites, and the double mutation A-61T/A-30T inactivated both binding sites . Thus, CopY is a copper-inducible repressor of the cop operon of E . hirae, exhibiting highly specific DNA-protein interactions with two sites on the cop promoter/operator and playing a key role in copper homeostasis in E . hirae.

J Biochem (Tokyo), 1997 Apr, 121(4), 779 - 86
Structural feature of the major but not cytokine-inducing molecular species of lipoteichoic acid; Hashimoto M et al.; Previously, lipoteichoic acid (LTA) of Enterococcus hirae was found to exhibit definite cytokine-inducing activity but synthetic specimens which share the fundamental structural principles proposed for LTA had no corresponding activity . We also showed recently that several minor components totally less than 5% of the LTA fraction from E . hirae ATCC 9790 possessed the activity, whereas the major component (over 90%) did not {Suda, Y., Tochio, H., Kawano, K., Takada, H., Yoshida, T., Kotani, S., and Kusumoto, S . (1995) FEMS Immun . Med . Microbiol . 12, 97-112} . In the present study, the structure of the major component of LTA was studied in an attempt to elucidate the reason for the lack of the activity in the synthetic compounds . The major component of the LTA was first digested by hydrofluoric acid hydrolysis to cleave phosphodiester linkages present . The hydrolysis products were separated and characterized by means of NMR and MS . The linkage positions of the original phosphodiesters were determined from the NMR spectra of an alkali-treated product without hydrofluoric acid degradation . The compound was proved to consist of 1,3-linked poly(glycerophosphate) and a lipid anchor, Glc(alpha1-2)Glc(alpha1-3)acyl(2)Gro, the former being linked to the 6-position of the distal glucose of the latter . The 2-position of the glycerol residues in the glycerophosphate part were substituted by oligoglucose esterified partially with alanine . The gross structure elucidated here thus coincides with the previous conclusion described by Fischer {Fischer, W . (1990) in Glycolipids, Phosphoglycolipids and Sulfoglycolipids (Kates, M., ed.) pp . 123 234, Plenum Press, New York} . Thus, the molecular species with this so-called "LTA structure" is not responsible for the cytokine-inducing activity.

Rinsho Byori, 1997 Apr, 45(4), 381 - 90
{Laboratory-evaluation of antimicrobial susceptibility testings to detect vancomycin-resistant enterococci}; Yamane N et al.; The emergence and dissemination of vancomycin-resistant enterococci (VRE) emphasizes the need for laboratories to be able to correctly detect them . The study described was conducted to evaluate the test methods presently available in Japan to discriminate between the isolates of VRE and those susceptible (VSE) . Among the phenotypic test methods evaluated, an agar screening method which utilized 8 micrograms per ml of vancomycin in Mueller-Hinton agar plate appeared to have a sufficient accuracy . When 23 isolates of vanA positive, 31 of vanB positive, 4 of both positive and 60 of both negative were tested, the sensitivity and specificity to detect VRE were estimated to be 98.3% and 100%, respectively . Also, all the VRE isolates were interpreted as being resistant or intermediate by the E test recently approved in Japan, when the results were read after 48 hr-incubation . Whereas, two disk diffusion tests, Showa disk and NCCLS-based Sensi-disc, were evaluated, but both methods failed to discriminate between VRE and VSE, in particular, between the isolates with vanB positive and negative . The automated system, Vitek GPS-TA produced high frequencies of very major errors; 8.7% for vanA positives and 58% for vanB positives . A total of 1,214 enterococcal isolates from multisite laboratories in Japan, comprising 7 different species, were first tested onto agar screening test plates, but none of isolates represented phenotypic vancomycin resistance . With these results, it can be recommended to detect VRE in clinical microbiology laboratories as follows: First, all the enterococcal isolates will be tested onto the agar screening plates or by the E test . Then, if the isolate is interpreted as being resistant or intermediate, the laboratory should confirm whether it is positive for vanA or vanB by polymerase chain reaction (PCR) specified.

Antimicrob Agents Chemother, 1997 Apr, 41(4), 872 - 4
Heterogeneous expression of glycopeptide resistance in enterococci associated with transfer of vanB; Hayden MK et al.; In mating experiments using a clinical strain that constitutively expresses vanB-encoded glycopeptide resistance, resistance transfer was detectable at a frequency of <10(-7) transconjugants/donor . Vancomycin MICs for transconjugants were 2- to 10-fold lower than those for the donor; both inducibly and constitutively resistant transconjugants were obtained . These findings demonstrate that the transfer of vanB among enterococci can be associated with substantial alterations in the level and control of glycopeptide resistance expression.

Int J Food Microbiol, 1997 Mar 18, 35(1), 57 - 66
Isolation of vancomycin resistant Enterococcus faecium from food; Wegener HC et al.; In a survey of vancomycin resistant Enterococcus faecium (VREF) in Danish meat products, VREF could be detected in 16% of 160 samples of broilers collected at slaughterhouses and in 15% of 26 samples of pork collected from the retail trade . VREF were isolated by enrichment for 24 h in nutrient broth supplemented with vancomycin (50 micrograms/ml) prior to plating on Slanetz and Bartley agar . Using direct plating on Slanetz and Bartley agar, VREF could be isolated from only 1.7% of 540 samples of broilers from slaughterhouses and 2.2% of 90 samples of broilers from retail outlets . VREF was not detected in 124 samples of pork and 128 samples of beef from retail outlets by the direct plating method . An additional enrichment step in nutrient broth supplemented with vancomycin enhanced the detection rate of VREF by approximately three times compared to the direct plating method when investigating the same 160 samples of broilers by the two methods . The implications and public health aspects of VREF in food is discussed.

Biochemistry, 1997 Mar 4, 36(9), 2531 - 8
D-alanine:D-alanine ligase: phosphonate and phosphinate intermediates with wild type and the Y216F mutant; Fan C et al.; The crystallographic structure of the D-alanine:D-alanine ligase of the ddlB gene of Escherichia coli complexed with a D-Ala-D-alpha-hydroxybutyrate phosphonate and the structure of the Y216F mutant ligase complexed with a D-Ala-D-Ala phosphinate have been determined to 2.2 and 1.9 A resolution, respectively, and refined to R factors of 0.156 and 0.158 . In each complex the inhibitor has reacted with ATP to produce ADP and a tight-binding phosphorylated transition state intermediate . Comparison of these two structures with the known crystal structure of the phosphinate intermediate of the wild-type ligase shows no major conformational changes, but B factors indicate differences in mobility of loops covering the binding site . The weaker inhibition of the Y216F mutant by both inhibitors is thought to be due in part to the loss of an interloop hydrogen bond . A similar mechanism may account for poor inhibition of VanA, the homologous D-Ala:D-lactate ligase produced by vancomycin-resistant enterococci.

Biochemistry, 1997 Mar 4, 36(9), 2353 - 9
Biologically important conformations of aminoglycoside antibiotics bound to an aminoglycoside 3'-phosphotransferase as determined by transferred nuclear Overhauser effect spectroscopy; Cox JR et al.; NMR spectroscopy has been used to study the interaction of aminoglycoside antibiotics with an aminoglycoside antibiotic 3'-phosphotransferase {APH(3')-IIIa} . APH(3')-IIIa is an enterococcal enzyme that is responsible for the ATP-dependent O-phosphorylation of a broad range of aminoglycoside antibiotics . The NMR method of transferred nuclear Overhauser effect spectroscopy (TRNOESY) was used to detect intra- and inter-ring NOEs for butirosin A and amikacin in their respective ternary complexes with APH(3')-IIIa and ATP . NOE-derived distance constraints were used in energy minimization and dynamics routines to yield enzyme-bound structures for butirosin A . These structures suggest that the 2,6-diamino-2,6-dideoxy-D-glucose and D-xylose rings have restricted motions and are in a stacking arrangement . The TRNOE spectra for amikacin suggest that the 6-amino-6-deoxy-D-glucose ring is flexible when the antibiotic is bound to APH(3')-IIIa . The 15N resonances of butirosin A were assigned and the pKa values of the amino groups of butirosin A and amikacin were determined by 15N NMR spectroscopy . The N3 amino groups of butirosin A and amikacin have lowered pKa values, which is attributed to the (S)-4-amino-2-hydroxybutyryl (AHB) group of the antibiotics . This work provides an insight into the geometrical and electrostatic nature of aminoglycoside antibiotics bound to a modifying enzyme and will provide a basis for the design of inhibitors of APH(3')-IIIa.

Am J Med, 1997 Mar, 102(3), 284 - 93
Vancomycin-resistant enterococci; Murray BE; Enterococci have been recognized as an important cause of nosocomial infections for almost 20 years and as a cause of endocarditis for almost a century . While long known for their capacity of displaying multiple antibiotic resistant traits, the extent to which this could occur was not fully appreciated until the emergence of enterococci with acquired resistance to vancomycin; this resistance has been particularly problematic because it often occurs in the uncommon subset of enterococci that are also highly resistant to ampicillin-a combination with devastating therapeutic consequences . The observation that vancomycin resistance can be transferred to and expressed in other gram-positive organisms, for which vancomycin is often considered the primary therapeutic alternative, is a chilling reminder of just how close we may be to a wide array of potentially untreatable "killer" microbes.

Diagn Microbiol Infect Dis, 1997 Mar, 27(3), 85 - 92
Assessment of the synergistic interactions of levofloxacin and ampicillin against Enterococcus faecium by the checkerboard agar dilution and time-kill methods; Smith CE et al.; Multidrug-resistant enterococci have become increasingly difficult to eradicate in a growing number of nosocomial infections . With the emergence of vancomycin-resistant enterococci, the use of synergistic antibiotic combinations has become one of the only remaining therapeutic options . Levofloxacin, the active l-isomer of ofloxacin, is a new oral and intravenous fluoroquinolone with a broad spectrum of activity against numerous Gram-positive, Gram-negative, and atypical organisms . The in vitro activity of levofloxacin, alone and in combination with ampicillin, against recent clinical isolates of Enterococcus faecium was assessed for synergistic interactions using the checkerboard agar dilution technique and time-kill methodology . Against all strains, the static technique of checkerboard agar dilution demonstrated indifferent or additive effects for the ampicillin + levofloxacin combination . With the dynamic time-kill technique, synergy was demonstrated for ampicillin (16 micrograms/ml) + levofloxacin (2 micrograms/ml) combination against three levofloxacin-sensitive, ampicillin-resistant isolates . At 24 h, the combination yielded a > or = 2-log10 decrease in CFU/ml compared to levofloxacin alone, while ampicillin had negligible effects . Against both a levofloxacin-intermediate, ampicillin-resistant isolate, and a highly levofloxacin-resistant, ampicillin-resistant isolate, none of the ampicillin+levofloxacin combinations tested demonstrated a synergistic interaction . The time-kill method suggested synergy for the ampicillin+levofloxacin combination against some strains of E . faecium.

J Perinatol, 1997 Mar-Apr, 17(2), 130 - 4
Use of human milk in the intensive care nursery decreases the incidence of nosocomial sepsis; el-Mohandes AE et al.; OBJECTIVES: This study compares stool colonization and incidence of sepsis in human milk-fed (HM) and formula-fed (FF) intensive care nursery (ICN) patients . STUDY DESIGN: Infants recruited prospectively were fed HM based on the decision of their mothers (59 HM and 114 FF) . The incidence of sepsis was determined during the following three intervals: period 1, first 10 days of life; period 2, 11 to 24 days; and period 3, 25 to 38 days . RESULTS: Frequency of Escherichia coli and Enterococcus sp . colonization was increased in HM infants . The incidence of sepsis was 9.5% in period 1 (5% in HM vs 10% in FF), 17.2% in period 2 (9% in HM vs 20% in FF), and 12.5% in period 3 (0% in HM vs 15% in FF) . The odds ratio for sepsis in HM infants was 0.4, the 95% limits 0.15 to 0.95, p = 0.04 . CONCLUSIONS: HM feeding in the ICN has a protective effect against nosocomial sepsis, which is unrelated to its influence on gastrointestinal (GI) flora.

Chem Biol, 1997 Mar, 4(3), 195 - 202
Production of hybrid glycopeptide antibiotics in vitro and in Streptomyces toyocaensis; Solenberg PJ et al.; BACKGROUND: The glycopeptide antibiotics vancomycin and teicoplanin are currently the last line of defence against some microorganisms that are resistant to many drugs . The emergence of vancomycin-resistant and teicoplanin-resistant enterococci underscores the need for more potent antibiotics . The glycosylation patterns of glycopeptides and chemical modifications of the glycosyl moieties have been shown to greatly influence their antibiotic activity, and certain combinations have resulted in highly active new compounds . To explore further the production of more potent glycopeptide antibiotics, we assessed whether glycosyltransferases could be used to produce hybrid compounds that contain various combinations of sugars and peptide cores . RESULTS: We cloned five glycosyltransferase genes from Amycolatopsis orientalis strains that produce vancomycin or a related glycopeptide, A82846 . The gtfB and gtfE' genes from A . orientalis strains expressed in Escherichia coli produced glucosyltransferase activities that added glucose or xylose to the vancomycin heptapeptide . The GtfE' protein added glucose efficiently to two other heptapeptides related to teicoplanin to produce hybrid glycopeptide antibiotics . The cloned gtfE' gene, driven by the strong constitutive promoter ermEp*, was introduced into Streptomyces toyocaensis, which produces the antibiotic A47934, a heptapeptide related to teicoplanin; recombinant organisms produced glucosyl A47934, a hybrid glycopeptide antibiotic . CONCLUSIONS: Cloned glycosyltransferases from glycopeptide antibiotic producers can be used to produce novel hybrid antibiotics, both in vitro and in vivo . Because similar enzymes have differing degrees of substrate specificity, it is advantageous to characterize the substrate specificity with enzymes expressed in E . coli prior to constructing recombinant actinomycetes for production.

Infection, 1997 Mar-Apr, 25(2), 127 - 8
Recurrent septicemias with Enterococcus faecium; Elsner HA et al.; A 17-year-old male patient with extrahepatic biliary atresia underwent an orthotopic liver transplantation in September 1994 . In blood cultures drawn in November and (6 weeks later) December 1994, from bile secretions in May 1995, stool in June 1995 an wound abscess in August 1995, ampicillin-resistant Enterococcus faecium was isolated . Pulsed-field gel electrophoresis demonstrated the clonal identity of the isolates . To our knowledge, repeated infections with the same E . faecium strain over a period of 9 months have not been described before . As multiple-resistant enterococci may colonize and reinfect liver transplant recipients for such a long time, preoperative antibiotic therapy should be administered cautiously in order not to select these organisms.

Infect Control Hosp Epidemiol, 1997 Mar, 18(3), 195 - 9
Susceptibility of vancomycin-resistant enterococci to environmental disinfectants; Anderson RL et al.; OBJECTIVE: To determine the susceptibilities of vancomycin-resistant and -sensitive enterococci (VRE and VSE) to various concentrations of commonly used, commercial, hospital-grade disinfectants . DESIGN: A microbial suspension test using inocula of 10(8) cells per mL in a disinfectant test dilution was used to determine inactivation kinetics of the test strains . In each test, 1-mL aliquots were removed from the cell-disinfectant mixtures at 15 and 30 seconds and then at 1-minute intervals for 5 minutes and neutralized . Appropriate serial dilutions were plated on agar medium for enumeration of survivors . RESULTS: VRE and VSE challenge inocula (in the absence of any additional protein or serum challenge) were below the limit of detection (5 colony-forming units/mL) after 15 seconds' exposure to the manufacturers' suggested use-dilutions of quaternary ammonium, phenolic, or iodophor germicidal detergents . In subsequent tests, when the disinfectants were diluted far beyond-the recommended use-dilutions (extended dilution), no differences were demonstrated between the susceptibilities of VRE and VSE . CONCLUSIONS: VRE and VSE are sensitive to a spectrum of commonly used environmental disinfectants and have parallel inactivation rates when challenged with extended dilutions of these products . Our findings did not demonstrate a relationship between antibiotic and germicide resistance . Routine disinfection and housekeeping protocols presently used in hospitals need not be altered due to concerns about the potential for environmentally mediated transmission of antibiotic-resistant microorganisms.

J Med Microbiol, 1997 Feb, 46(2), 150 - 6
Incidence and detection of multi-drug-resistant enterococci in Dublin hospitals; Lavery A et al.; In February 1994, an outbreak of vancomycin-resistant Enterococcus faecium (VREM) occurred in the oncology unit of a Dublin hospital . Between February and July 1994, VREM was isolated from 18 patients, one staff member and 14 environmental sites within the unit . The isolates also had high-level aminoglycoside and penicillin resistance . Three pulsed-field gel electrophoresis (PFGE) types were identified, two of them from multiple patients and environmental sites . Plasmid typing allowed subdivision of PFGE types . A retrospective study of enterococci isolated from blood cultures between January 1991 and January 1994 showed that, before the outbreak, fewer than 2% of isolates were vancomycin-resistant but that the incidence of high-level gentamicin resistance had increased from 17% to 60% and ampicillin resistance from 22% to 51% . Among clinically significant non-blood-culture enterococci isolated between September and December 1993, fewer than 1% were vancomycin-resistant, 13% were ampicillin-resistant and 44% highly gentamicin-resistant . None produced beta-lactamase . High-content gentamicin disks (120 micrograms) and low-content vancomycin disks (5 micrograms) allowed simple, reliable detection of resistant enterococci . MICs of vancomycin and teicoplanin determined by agar dilution and E-test agreed well, but values tended to be slightly lower by E-test.

J Clin Microbiol, 1997 Feb, 35(2), 388 - 92
Clonal dissemination and colony morphotype variation of vancomycin-resistant Enterococcus faecium isolates in metropolitan Detroit, Michigan; Dunne WM Jr et al.; Thirty-two isolates of vancomycin-resistant Enterococcus faecium (VRE) recovered from 25 patients hospitalized at six hospitals in the metropolitan Detroit, Mich., area over a 32-month period were examined for relatedness by repetitive-sequence PCR (rep-PCR) . All isolates were shown to carry the vanA gene by PCR . The rep-PCR patterns generated from each isolate showed that the first three VRE isolates obtained from hospital A between June 1992 and February 1994 were distinct strains . Thereafter, all VRE isolates originating from hospital A and those collected from five other area hospitals had identical rep-PCR patterns . On detailed examination, subcultures of 25 of the 32 VRE isolates produced two distinct colony types characterized phenotypically by a rough and a smooth appearance, respectively . Both colony types retained the vanA locus and the rep-PCR pattern of the primary isolate . These data suggest that a single strain of VRE with the capacity to produce two colonial variants has been disseminated to several Detroit-area hospitals . The clinical significance of the colonial morphotypes is unclear.

Ned Tijdschr Geneeskd, 1997 Jan 11, 141(2), 108 - 9
{Vancomycin-resistant enterococci . Work Group Hospital Infection Epidemiology}; Endtz HP et al.; Since 1995 patients with infections with vancomycin-resistant enterococci (VRE) have been reported in Rotterdam, the Netherlands . From prevalence studies in the Netherlands at the end of 1995 and the start of 1996, it appeared that 2% of the patients studied in and outside hospitals had VRE . Restrictive antibiotic prescription in human and veterinary medicine is indicated in order to postpone the problem.

Scand J Infect Dis, 1997, 29(3), 259 - 63
Intrahospital spread of vancomycin-resistant Enterococcus faecium in Sweden; Torell E et al.; During a 17-week period vancomycin-resistant Enterococcus faecium (VRE) was found in clinical specimens from 4 in-patients . All bacterial isolates were phenotypically VanA, showing high-level resistance to vancomycin (MIC 256 micrograms/ml) and teicoplanin (MIC 24-256 micrograms/ml) . The corresponding gene (vanA) was detected with PCR in strains from 3 of the patients . Three patients had been hospitalized at the renal unit at Orebro Medical Centre Hospital (OMCH) . The fourth patient, diagnosed in another hospital, had received treatment in the oncology unit at OMCH . All patients recovered without treatment specific for VRE . Isolates from 2 patients were indistinguishable by pulsed-field gel electrophoresis of genomic DNA . Genetically, these strains were related to the VRE isolates from the 2 other patients . Screening of hospital staff and other in-patients for gastrointestinal carriage of VRE was negative . Glycopeptide-resistant enterococci have not previously been found in OMCH . No new cases were identified during a 10-month follow-up period . Our cases represent the first nosocomial outbreak of VRE in Sweden.

J Ind Microbiol Biotechnol, 1997 Jan, 18(1), 62 - 7
Growth and bacteriocin production by Enterococcus faecium DPC1146 in batch and continuous culture; Parente E et al.; Production of the bacteriocin enterocin 1146 (E1146) by Enterococcus faecium DPC1146 was studied in batch and continuous fermentation . Growth was strongly inhibited by lactic acid . In batch fermentations maximum E1146 activity (2.8 MBU L-1) was obtained in 9 h with 20 g L-1 glucose . Increase in initial glucose concentration did not lead to a proportional increase in E1146 activity . A simple linear model was found to be adequate to explain the relationship between specific bacteriocin production rate and specific growth rate in batch fermentations with initial glucose concentration higher than 20 g L-1 . Maximum bacteriocin activity (2.9-3.2 MBU L-1) was obtained in continuous fermentations at dilution rates between 0.12 and 0.17 h-1 and specific bacteriocin production rate increased linearly with dilution rate.

Arch Surg, 1997 Jan, 132(1), 76 - 81
Enterococcal bacteremia in the surgical intensive care unit . Does vancomycin resistance affect mortality? The Johns Hopkins SICU Study Group; Mainous MR et al.; OBJECTIVE: To determine the incidence and mortality rate associated with nosocomial bacteremia caused by vancomycin-resistant Enterococcus in a surgical intensive care unit . DESIGN: A retrospective study . SETTING: The surgical intensive care unit of a large university hospital tertiary referral center . PATIENTS: All patients in the surgical intensive care unit with a documented nosocomial bacteremia between January 1, 1992, and December 31, 1994 . INTERVENTIONS: None . MAIN OUTCOME MEASURE: Mortality rate . RESULTS: Of the 134 nosocomial bacteremic episodes, 30.6% involved enterococci; 24.4% of the enterococci were resistant to vancomycin . Patients with vancomycin-resistant enterococcal bacteremia had a significantly longer hospital stay (mean +/- SD, 28 +/- 18 vs 12 +/- 10 days; P = .005) and were more likely to have been treated with vancomycin (70% vs 10.3%; P = .001) than patients with vancomycin-sensitive enterococcal bacteremia . The mortality (41.0%) associated with enterococcal bacteremia was similar to the overall bacteremic mortality (41.7%) . There was no difference in episode-specific mortality associated with vancomycin-resistant enterococci (40%) vs vancomycin-sensitive enterococci (38.7%) . Of the 4 deaths associated with vancomycin-resistant enterococcal bacteremia, only 2 occurred within 14 days of the bacteremia, as did 8 of 12 deaths associated with vancomycin-sensitive enterococcal bacteremia (P = .64) . CONCLUSIONS: Enterococci were the most commonly isolated nosocomial blood-borne pathogens in the surgical intensive care unit . Nearly 25% of the enterococcal bacteremic episodes were resistant to vancomycin . Vancomycin-resistant Enterococcus is associated with a prolonged hospital stay and with vancomycin use . Nevertheless, vancomycin resistance itself does not increase the mortality rate associated with enterococcal bacteremia.

J Bacteriol, 1997 Jan, 179(1), 97 - 106
The VanS sensor negatively controls VanR-mediated transcriptional activation of glycopeptide resistance genes of Tn1546 and related elements in the absence of induction; Arthur M et al.; Transposon Tn1546 from Enterococcus faecium BM4147 encodes a histidine protein kinase (VanS) and a response regulator (VanR) that regulate transcription of the vanHAX operon encoding a dehydrogenase (VanH), a ligase (VanA), and a D,D-dipeptidase (VanX) . These last three enzymes confer resistance to glycopeptide antibiotics by production of peptidoglycan precursors ending in the depsipeptide D-alanyl-D-lactate . Transcription of vanS and the role of VanS in the regulation of the vanHAX operon were analyzed by inserting a cat reporter gene into vanS . Transcription of cat and vanX was inducible by glycopeptides in partial diploids harboring vanS and vanS(omega)cat but was constitutive in strains containing only vanS(omega)cat . Promoters P(R) and P(H), located upstream from vanR and vanH, respectively, were cloned into a promoter probing vector to study transactivation by chromosomally encoded VanR and VanS . The promoters were inactive in the absence of vanR and vanS, inducible by glycopeptides in the presence of both genes, and constitutively activated by VanR in the absence of VanS . Thus, induction of the vanHAX operon involves an amplification loop resulting from binding of phospho-VanR to the P(R) promoter and increased transcription of the vanR and vanS genes . Full activation of P(R) and P(H) by VanR was observed in the absence of VanS, indicating that the sensor negatively controls VanR in the absence of glycopeptides, presumably by dephosphorylation . Activation of the VanR response regulator in the absence of VanS may involve autophosphorylation of VanR with acetyl phosphate or phosphorylation by a heterologous histidine protein kinase.

FEBS Lett, 1996 Dec 9, 399(1-2), 143 - 6
Phosphoenzyme formation by purified, reconstituted copper ATPase of Enterococcus hirae; Wyler-Duda P et al.; The Enterococcus hirae CopB ATPase serves in the secretion of excess copper from cells and belongs to the recently discovered, new class of heavy metal transport ATPases . We here report the affinity purification of CopB to near homogeneity and its reconstitution into phospholipid vesicles . In these proteoliposomes, the ATPase formed an acylphosphate reaction intermediate with the gamma-phosphate of ATP . ATPase activity and phosphoenzyme formation were inhibited by vanadate with an I(50) of 0.1 mM . Our results suggest that heavy metal and non-heavy metal ATPases operate by the same underlying mechanism.

Clin Infect Dis, 1996 Dec, 23(6), 1234 - 9
Vancomycin-resistant enterococcal bacteremia: natural history and attributable mortality; Edmond MB et al.; Previous studies have shown that bacteremia due to vancomycin-resistant Enterococcus species (VRE) is associated with mortality of 17%-100%, but comorbid conditions may have confounded the estimates . We designed a historical cohort study to determine the mortality attributable to VRE bacteremia . Twenty-seven patients with VRE bacteremia were identified as cases . Within 7 days of the onset of bacteremia, severe sepsis developed in 12 patients (44%) and septic shock developed in 10 (37%) . Case patients were closely matched to control patients without VRE bacteremia (1:1) by time of hospitalization, duration of exposure, underlying disease, age, gender, and surgical procedure . The mortality was 67% among cases and 30% among matched controls (P = 0.1) . Thus, the mortality attributable to VRE bacteremia was 37% (95% confidence interval {CI}, 10%-64%) and the risk ratio for death was 2.3 {CI, 1.2-4.1) . We conclude that VRE bacteremia is associated with high rates of severe sepsis and septic shock . The attributable mortality approaches 40%, and patients who have VRE bacteremia are twice as likely to die than closely matched controls.

Bratisl Lek Listy, 1996 Nov, 97(11), 680 - 3
Do low vancomycine serum levels predict failures of vancomycine therapy in neutropenic cancer patients?
Netriova J, Hal'ko J, Studena-Mrazova M, Kukuckova E, Stopkova K, Kral'ovicova K, Demitrovicova A, Grausova S, Krupova I, Trupl J, Krcmery V Jr.
Vancomycine serum levels were measured in 198 cancer patients with documented grampositive bacteremia and twenty two failed . Failures were analyzed for risk factors of therapy failure . Only 8 of 22 showed low serum peak or through vancomycin levels . One patient was treated less than 7 days, 9 had persisting and 4 catheter associated bacteremia . Bacteremias due to VAN resistant strains were excluded . In 14 out of 22 patients, multiple or one risk factor could be determined, but in 8 patients, no risk factor was found . Hence the, case control study was conducted to compare the group of failures in 22 patients with a group of patients with underlying disease and neutropenia treated successfully within the same period and same antibiotic policy at the same cancer center, by VAN for gram-positive bacteremia . Persisting, catheter associated and enterococcal bacteremias were the only statistical significant risk factors predicting a therapy failure in cancer patients . Neither Vancomycine serum peak nor through levels predicted the outcome: failure or cure of gram-positive bacteremia in cancer patients . (Tab . 1, Ref . 5.).

J Hosp Infect, 1996 Nov, 34(3), 191 - 6
Heat and chemical resistance of enterococci; Bradley CR et al.; Recent reports have highlighted the tolerance of vancomycin-resistant strains of enterococci to heat . This study examined the tolerance of vancomycin-resistant and sensitive strains of enterococci and an NCTC type strain to 65, 71 and 80 degrees C, and also to low concentrations of a chlorine-releasing agent, alcohol and glutaraldehyde . Variation in the tolerance to chemicals was observed but there was no correlation between vancomycin resistance and tolerance to chemical disinfectants . The NCTC type strain was killed within the time/temperature parameters set by the Department of Health for thermal washer/disinfectors, i.e . 65 degrees C for 10 min, 71 degrees C for 3 min and 80 degrees C for 1 min . However, the clinical strains showed varying resistance to heat, irrespective of their vancomycin susceptibility . One strain survived 80 degrees C for 3 min . These results showed that clinical isolates can be resistant to commonly used disinfection processes, although the practical significance of these results is debatable.

J Hosp Infect, 1996 Nov, 34(3), 171 - 82
Epidemiology of an outbreak due to glycopeptide-resistant Enterococcus faecium on a leukaemia unit; Chadwick PR et al.; The clinical and molecular epidemiology of two clusters of colonization and infection of patients by glycopeptide-resistant enterococci (GRE) on a leukaemia and bone marrow transplantation unit was studied over a two-and-a half-year period . Thirty-five patients became colonized, of whom six developed clinical infections . Of the 53 isolates of GRE, 49 were Enterococcus faecium, multiply-resistant to vancomycin and ampicillin . DNA fingerprinting of 48 E . faecium isolates by pulsed-field gel electrophoresis identified six DNA types . One strain of VanB phenotype E . faecium predominated during the initial outbreak, and an unrelated strain of the VanA phenotype was present in a second cluster . Environmental and patient isolates of E . faecium were indistinguishable by DNA typing . The VanA phenotype enterococci probably arose by transfer from the renal ward at a nearby hospital, and a patient with persistent diarrhoea may have contributed to contamination and cross-infection . GRE may cause significant infections in immunocompromised patients, and are readily transmitted between them . GRE were controlled, but not eradicated on the unit; infection control measures included improved environmental cleaning and modification of antibiotic use . In order to control GRE, it is necessary to educate healthcare workers and implement the traditional, effective values of good personal hygiene and environmental cleanliness.

J Clin Microbiol, 1996 Nov, 34(11), 2841 - 2
Comparison of inoculation methods for testing enterococci by using vancomycin screening agar; Jorgensen JH et al.; One hundred four recent clinical isolates of Enterococcus species were screened for vancomycin resistance by using inocula of 10(5) or 10(6) CFU dispensed by pipet and by use of a cotton swab dipped in a 0.5 McFarland standard organism suspension applied to the surface of brain heart infusion agar containing 6 micrograms of vancomycin per ml . The three inoculation methods were equivalent in the detection of nonsusceptible isolates . The use of swab inoculation was convenient and less costly than the use of micropipets.

Diagn Microbiol Infect Dis, 1996 Oct, 26(2), 79 - 85
Bactericidal activity of the fluoroquinolone DU-6859a alone and in combination with other antimicrobial agents against multiresistant enterococci; Korten V et al.; The in vitro activity of DU-6859a (DU) alone and in combination with various antimicrobials was evaluated against multiresistant enterococci including some isolates with defined gyrA mutations . DU produced rapid in vitro killing against most enterococci that lacked resistance to ciprofloxacin, but it was not bactericidal against strains with MICs of ciprofloxacin of > or = 8 micrograms/ml, or against one of four strains with an MIC of ciprofloxacin of 4 micrograms/ml . The combination of DU with rifampin was antagonistic against two of two isolates tested . Combinations of DU and novobiocin, gentamicin, or a beta-lactam (amoxicillin, ampicillin-sulbactam, or amoxicillin-clavulanate) were generally indifferent . When different beta-lactams were used together, with or without DU, bactericidal activity was observed against some isolates . Despite the absence of synergistic interactions with other agents, DU is a promising fluoroquinolone for use against enterococci, although prior development of resistance to currently available fluoroquinolones diminishes some of its effect.

Eur J Clin Microbiol Infect Dis, 1996 Oct, 15(10), 826 - 9
Serological investigation of enterococcal infections using western blot; Sulaiman A et al.; To assess the usefulness of Western blot in the diagnosis of enterococcal infections, a pilot study was conducted with a newly developed Western blot using sera from patients with confirmed enterococcal infections . Sera from 17 of 19 patients with enterococcal endocarditis reacted strongly to enterococcal antigens on the Western blot, and most produced specific bands at molecular weights 98 kDa and 54 kDa . Sera from patients with bacteremic cholangitis and pyelonephritis reacted frequently as well, but the pattern of bands was different from that observed with endocarditis . Eighty-five percent of 26 sera tested from patients with bacteremia and associated deep-seated infections (endocarditis, cholangitis, and pyelonephritis) were positive on Western blot, compared to 30% of sera from bacteremic patients with no clinically determined deep focus of infection (p < 0.001).

Clin Infect Dis, 1996 Oct, 23(4), 767 - 72
Risk factors associated with vancomycin-resistant Enterococcus faecium infection or colonization in 145 matched case patients and control patients; Tornieporth NG et al.; Risk factors and mortality associated with vancomycin-resistant Enterococcus faecium (VREF) infection or colonization were examined at a tertiary care hospital by comparing 145 patients who had VREF isolates (cases) to 145 patients with vancomycin-susceptible Enterococcus faecium (VSEF) isolates (controls) . The number of deaths per 100 person-days of hospitalization after diagnosis did not differ significantly between VREF patients (1.2) and VSEF patients (0.8) . Multivariate analyses found that the duration of hospitalization ( > or = 7 days), intrahospital transfer between floors, use of antimicrobials (i.e., vancomycin and third-generation cephalosporins), and duration of vancomycin use ( > or = 7 days) was independently associated with VREF infection or colonization . This study, which has a large sample size, confirms some earlier observations regarding risks for VREF infection or colonization and identifies factors that may be potentially exploited to develop interventional strategies for the control of this emerging nosocomial problem.

Clin Infect Dis, 1996 Oct, 23(4), 760 - 6
Nosocomial infections with vancomycin-resistant Enterococcus faecium in liver transplant recipients: risk factors for acquisition and mortality; Papanicolaou GA et al.; The risk factors for acquisition of and mortality due to nosocomial infection with vancomycin-resistant Enterococcus faecium (VREF) in orthotopic liver transplant (OLT) recipients were studied at a tertiary care hospital; 32 VREF-infected OLT patients (cases) were compared with 33 randomly selected OLT recipients (controls) . More antibiotics were administered preoperatively to cases (mean, 4 antibiotics per patient for 474 antibiotic-days) than to controls (mean, 1.8 antibiotics per patient for 131 antibiotic-days) . Cases were more likely than controls to have received vancomycin therapy preoperatively and to have been hospitalized in the intensive care unit (ICU) preoperatively . Logistic regression revealed that the risk factors for acquisition of VREF infection were surgical reexploration and a prolonged stay in the surgical ICU postoperatively . In the cases, the risk factors for mortality were admission to the ICU preoperatively and hemodialysis . The mortality rate associated with polymicrobial bloodstream infections was 100% despite appropriate therapy . Sixteen and 18 cases received parenteral chloramphenicol and doxycycline, respectively, for treatment of VREF infection . There were no hematologic adverse effects attributed to chloramphenicol treatment . DNA analysis of selected E . faecium isolates suggested that infections were due to multiple clones . In summary, the source of VREF infection in OLT patients is the gastrointestinal tract . Antibiotic selective pressure may contribute to colonization . Infection with VREF is a predictor of morbidity and mortality in OLT patients.

Clin Podiatr Med Surg, 1996 Oct, 13(4), 661 - 9
Vancomycin-resistant enterococci; Thakor K et al.; The enterococcus has emerged as one of the most important nosocomial pathogens: an organism with the ability to develop resistance to all available antibiotics . This article details the historic significance of the enterococcus and delineates the clinical presentations and therapeutic options for the clinician . In addition, recent guidelines from the Centers for Disease Control and Prevention are reviewed, and additional steps are suggested to prevent the spread of this scourge of the 1990s.

Trends Microbiol, 1996 Oct, 4(10), 401 - 7
Glycopeptide resistance in enterococci; Arthur M et al.; Glycopeptide resistance in enterococci results from the production of peptidoglycan precursors with low affinity for these antibiotics . The mobility of the resistance genes by transposition and conjugation and the ability of the resistance proteins to interfere with synthesis of normal precursors in different hosts indicate that dissemination into other bacterial species should be anticipated.

Pediatr Infect Dis J, 1996 Oct, 15(10), 848 - 54
Vancomycin-resistant Enterococcus faecium on a pediatric oncology ward: duration of stool shedding and incidence of clinical infection; Henning KJ et al.; OBJECTIVE: To determine the duration of stool shedding and incidence of clinical infection among pediatric oncology patients colonized with vancomycin-resistant Enterococcus faecium (VRE) in our institution . METHODS: Stool cultures were obtained from all patients admitted from May 15 to August 2, 1994 . Patients were followed for evidence of clinical VRE infection and surveillance stool results through August 15, 1995 . Genetic relatedness of stool-clinical isolate pairs and serial stool samples was evaluated using pulsed field gel electrophoresis . RESULTS: Twenty-three (32%) of 73 screened patients were colonized with VRE . Eight (35%) of the colonized patients cleared VRE from stool; 10 (43%) were persistent carriers, excreting organisms for 19 to 331 days (median, 112 days); and 5 patients had an insufficient number of stools to determine length of carriage . Persistent carriers had a median of 6 hospital readmissions; 8 of 10 were positive at first or second readmission Clinical VRE infection developed in 6 of 73 patients (annual incidence, 8.2%) . Clinical cases had more days of neutropenia between colonization and infection than colonized patients during a comparable follow-up (49 vs . 16 days, P = 0.04) . Five of 6 stool-clinical isolate pairs were identical by pulsed field gel electrophoresis . Serial stools from 6 of 7 patients (collected 20 to 343 days apart) were identical by pulsed field gel electrophoresis . CONCLUSION: Persistent gastrointestinal colonization with VRE is common among pediatric oncology patients . Carriage of the same VRE clone for up to 1 year was demonstrated . In the majority of cases invasive and colonizing isolates were identical by DNA fingerprinting techniques, suggesting that the colonizing VRE was the source of infection . Intermittent excretion of organisms in stool makes vigilant tracking and immediate isolation of such patients crucial to control efforts . Prolonged neutropenia may increase the risk of developing clinical infection among VRE-colonized patients.

Antimicrob Agents Chemother, 1996 Oct, 40(10), 2356 - 62
Inhibition of peptidoglycan biosynthesis in vancomycin-susceptible and -resistant bacteria by a semisynthetic glycopeptide antibiotic; Allen NE et al.; LY191145 is a p-chlorobenzyl derivative of LY264826 (A82846B) with activity against both vancomycin-susceptible and -resistant enterococci . Incorporation of L-{14C}lysine into peptidoglycan of intact vancomycin-susceptible and -resistant Enterococcus faecium was inhibited by LY191145 (50% inhibitory concentrations of 1 and 5 microgram/ml, respectively) . Inhibition was accompanied by accumulation of UDP-muramyl-peptide precursors in the cytoplasm . This agent inhibited late-stage steps in peptidoglycan biosynthesis in permeabilized E . faecium when either the UDP-muramyl-pentapeptide precursor from vancomycin-susceptible E . faecium or the UDP-muramyl-pentadepsipeptide precursor from vancomycin-resistant E . faecium was used as a substrate . Inhibition of late-stage steps led to accumulation of an N-acetyl-{14C}glucosamine-labeled lipid intermediate indicative of inhibition of the transglycosylation step . Inhibition of peptidoglycan polymerization without affecting cross-linking in a particulate membrane-plus-wall-fragment assay from Aerococcus viridans was consistent with this explanation . The fact that inhibition of peptidoglycan biosynthesis by LY191145 was not readily antagonized by an excess of free acyl-D-alanyl-D-alanine or acyl-D-alanyl-D-lactate ligands indicates that the manner in which this compound inhibits transglycosylation may not be identical to that of vancomycin.

Appl Environ Microbiol, 1996 Oct, 62(10), 3881 - 4
Evaluation of Enterolert for enumeration of enterococci in recreational waters; Budnick GE et al.; Enterolert (IDEXX Laboratories Inc., Westbrook, Maine), a semiautomated, most probable number method for enumeration of enterococci, was compared with the standard membrane filter method by parallel testing of 138 marine and freshwater recreational bathing water samples . No statistically significant difference and a strong linear correlation were found between methods . Culturing of 501 Enterolert test wells resulted in false-positive and false-negative rates of 5.1 and 0.4%, respectively . Less time for setup, incubation (24 versus 48 h), and reading of Enterolert permits more efficient monitoring of recreational bathing areas.

J Bacteriol, 1996 Oct, 178(20), 6078 - 81
Gene transfer in Mycoplasma arthritidis: transformation, conjugal transfer of Tn916, and evidence for a restriction system recognizing AGCT; Voelker LL et al.; Mycoplasma arthritidis is a rat pathogen causing a severe polyarthritis . The study of its pathogenic mechanisms has been hampered by the lack of genetic systems for use with M . arthritidis . Described here are procedures for genetic transformation of M . arthritidis and conjugal transfer of Tn916 from an enterococcal donor to M . arthritidis . The location of Tn916 insertion sites in the mycoplasmal chromosome was random, suggesting that Tn916 may be useful as an insertional mutagen in this organism . Additionally, a restriction and modification system was identified which presented a strong barrier to gene transfer . For transformation, the restriction system was circumvented by using DNA that was modified in vitro with the appropriate site-specific methylase (AluI).

J Biol Chem, 1996 Sep 27, 271(39), 23661 - 6
Intracellular Na+ regulates transcription of the ntp operon encoding a vacuolar-type Na+-translocating ATPase in Enterococcus hirae; Murata T et al.; The Gram-positive bacterium Enterococcus hirae has a vacuolar-type Na+-translocating ATPase that is encoded by the ntp operon (ntpFIKECGABDHJ) (Takase, K., Kakinuma, S., Yamato, I., Konishi, K., Igarashi, K., and Kakinuma, Y . (1994) J . Biol . Chem . 269, 11037-11044) . Primer extension experiments identified the start site of transcription of this operon upstream of the ntpF gene . In parallel with the increases of both Na+-pumping activity in whole cells and Na+-stimulated ATPase activity in the membranes, the amounts of the two major subunits (A and B) of this enzyme increased remarkably in cells grown on medium containing high concentrations of NaCl but not on medium containing KCl or sorbitol . Chloramphenicol completely abolished the increases of the enzyme activity and the amounts of A and B subunits, suggesting that the Na+-ATPase level increased by de novo synthesis of the enzyme with the stimulation of high concentrations of the external sodium ions . Finally, Western blot and Northern blot experiments revealed that the increase in the Na+-ATPase level with the external Na+ was further accelerated by addition of an ionophore, such as monensin, which rendered the cell membrane permeable to Na+ . These results suggest that the transcription of the Na+-ATPase operon is regulated by the intracellular concentration of sodium ions.

Ann Intern Med, 1996 Sep 15, 125(6), 448 - 56
A comparison of the effect of universal use of gloves and gowns with that of glove use alone on acquisition of vancomycin-resistant enterococci in a medical intensive care unit; Slaughter S et al.; OBJECTIVE: To determine the efficacy of the use of gloves and gowns compared with that of the use of gloves alone for the prevention of nosocomial transmission of vancomycin-resistant enterococci . DESIGN: Epidemiologic study and controlled, nonrandomized clinical trial . SETTING: University-affiliated, 900-bed, urban teaching hospital in which vancomycin-resistant enterococci are endemic . PATIENTS: 181 consecutive patients admitted to the medical intensive care unit for 48 hours or more . INTERVENTION: It was determined that all hospital employees would always use gloves and gowns when attending 8 particular beds in the medical intensive care unit and would always use gloves alone when attending 8 others . Compliance with precautions was monitored weekly . Rectal surveillance cultures were taken from patients daily . Cultures of environmental surfaces, such as those of bed rails, bedside tables, and other frequently touched objects in patient rooms and common areas, were taken monthly . Pulsed-field gel electrophoresis was used for molecular epidemiologic typing of vancomycin-resistant enterococci . MEASUREMENTS: The number of patients becoming colonized by vancomycin-resistant enterococci; the number of days to acquisition of vancomycin-resistant enterococci; and other measurements, including nosocomial infections, length of hospital stay, and mortality rates . RESULTS: The 93 patients in glove-and-gown rooms and the 88 patients in glove-only rooms had similar demographic and clinical characteristics . Fifteen (16.1%) patients in the glove-and-gown group and 13 (14.8%) in the glove-only group had vancomycin-resistant enterococci on admission to the medical intensive care unit . Twenty-four (25.8%) patients in the glove-and-gown group and 21 (23.9%) in the glove-only group acquired vancomycin-resistant enterococci in the medical intensive care unit . The mean times to colonization among the patients who became colonized were 8.0 days in the glove-and-gown group and 7.1 days in the glove-only group . None of these comparisons were statistically significant . Risk factors for acquisition of vancomycin-resistant enterococci induced length of stay in the medical intensive care unit, use of enteral feeding, and use of sucralfate . Compliance with precautions was 79% in glove-and-gown rooms and 62% in glove-only rooms (P < 0.001) . Only 25 of 397 (6.3%) environmental cultures were positive for vancomycin-resistant enterococci . Nineteen types of vancomycin-resistant enterococci were documented by pulsed-field gel electrophoresis during the study period . CONCLUSIONS: Universal use of gloves and gowns was no better than universal use of gloves only in preventing rectal colonization by vancomycin-resistant enterococci in a medical intensive care unit of a hospital in which vancomycin-resistant enterococci are endemic . Because the use of gowns and gloves together may be associated with better compliance and may help prevent transmission of other infectious agents, this finding may not be applicable to outbreaks caused by single strains or hospitals in which the prevalence of vancomycin-resistant enterococci is low.

J Assoc Physicians India, 1996 Sep, 44(9), 602 - 5
'O' set connector system in CAPD; Annigeri RA et al.; 51 CAPD patients (age 55.5 +/- 14.5 yrs, 35 male, 16 female) on CAPD using 'O' set were studied retrospectively during the period January 1993 to April 1995 . Etiology of ESRD was Diabetic nephropathy-25(49%) and the other causes-26(51%) . The total duration of observation on 'O' set was 553 patient months, the mean duration was 10.8 +/- 6.1 months . 24 patients (47%) developed total of 30 episodes of peritonitis . The incidence of peritonitis was 18.4 patient months per episode of peritonitis . The organisms responsible for peritonitis were Gram positive-6(20%), Gram negative-3(10%), Fungal-1(3.3%), Mycobacterial-1(3.3%), Eosinophilic-1(3.3%), Sterile-12(40%) and unknown-6(20%) 2 patients of bacterial peritonitis and a patient with tuberculous peritonitis died while rest of the patients responded favourably to antibiotics . 13(52%) diabetic patients and 11(42%) non-diabetic patients had peritonitis (p-NS) and the peritonitis rates in diabetics and non diabetics were 18.3 and 18.6 patient months per episode respectively (p-NS) . Exit site infection was seen in 5 patients (10%) (Staph aureus-4, Enterococci-1) and all responded to antibiotic therapy . 7 patients had total of 10 episodes of symptomatic accidental intraperitoneal sodium hypochlorite instillation, none had any long term adverse effects . The 'O' set procedure was done by self in 10(20%) and by others in 41(80%) cases . The peritonitis rates when performed by self and others were 18.5 and 18.4 patient months per episode respectively (p-NS) . The cost of being on CAPD using 'O' set, Y-bag and twin bag were Rs . 1,50,000, 2,10,000 and 3,72,000 per annum respectively and cost of maintenance haemodialysis was 1,36,800 per annum . The cost of CAPD using 'O' set was comparable to that of maintenance haemodialysis . The 'O' set connector system in CAPD is found to be safe, cost effective and efficient.

Scand J Gastroenterol, 1996 Sep, 31(9), 887 - 91
Efficacy of SF 68 in the treatment of acute diarrhea . A placebo-controlled trial; Buydens P et al.; BACKGROUND: The therapeutic value of Bioflorin, a preparation containing Enterococcus SF 68 strain, was evaluated in adult patients with acute diarrhea . METHODS: In a double-blind randomized trial we compared the effect of SF 68 strain in a dose of 150 x 10(6) colony-forming units three times a day for 5 days compared with placebo on the duration of diarrhea in 211 adults . RESULTS: Patients receiving SF 68 had a reduced duration of diarrhea compared with placebo, with a highly statistically significant difference between treatments . The proportion of patients with continuing diarrhea during the 2nd day of treatment was 61% in patients receiving SF 68 and 96% in those receiving placebo (P < 0.01) . During the 3rd day diarrhea was still present in 8% of patients given SF 68, compared with 66% of those given placebo (P < 0.01) . The mean (+/-SD) duration of diarrhea was 1.69 days (0.6) in patients given SF 68 compared with 2.81 days (0.9) in those given placebo . When pathogens were found in the first stool culture, they could not be detected at post-treatment examination . No adverse reactions were observed . CONCLUSIONS: Oral bacteriotherapy with SF 68 strain shortens the duration and the severity of diarrhea in adults and represents a safe and effective approach to re-establishing a balanced microbial flora in this condition.

Pharmacotherapy, 1996 Sep-Oct, 16(5), 819 - 29
Vancomycin-resistant enterococci; Palmer SM et al.; Vancomycin-resistant enterococci (VRE) are a major problem in numerous institutions in the United States . Most VRE are resistant to all available antimicrobial agents, resulting in serious therapeutic dilemmas . The resistance genes are transmitted on transposons, so the potential for dissemination to other species is significant . Risk factors associated with VRE infection and colonization are vancomycin and cephalosporin use, but numerous patient-related factors also contribute . Although resistant strains appear to arise from the patient's endogenous flora, VRE may be spread through direct contact with contaminated environmental surfaces and hands of caregivers . Published guidelines for preventing such spread suggest implementing infection-control practices and vancomycin restrictions . The ideal drug regimen for the treatment of VRE is unknown . Various drug combinations have been studied in the laboratory, but patient treatment data are scarce . There is an urgent need for new antimicrobial agents.

Infect Control Hosp Epidemiol, 1996 Sep, 17(9), 576 - 80
Risk factors for mortality associated with enterococcal bloodstream infections; Stroud L et al.; OBJECTIVE: To determine risk factors for mortality in patients with a nosocomial enterococcal primary bloodstream infection (EPBI) and to assess whether vancomycin resistance placed a patient at increased risk of death . DESIGN/SETTING: A retrospective cohort study was conducted in four National Nosocomial Infection Surveillance System hospitals . RESULTS: Of 145 patients identified with EPBIs, 74 (51%) died, and 26 (18%) had a vancomycin-resistant isolate . Upon comparing patients with EPBIs who survived to those who died, no associations were found between mortality and prior invasive device use, procedure history, type or number of prior nosocomial infections, length of hospitalization before infection, or receipt of vancomycin . Independent predictors of mortality were indices of severity of illness (APACHE II score and comorbidity weighted index), age, the use of third-generation cephalosporins or metronidazole during the week prior to infection, and female gender . CONCLUSIONS: Vancomycin resistance was not an independent predictor of death, and its role was difficult to establish, because cohort patients were among the most severely ill of all hospitalized patients . Enterococcal primary bloodstream infections appear to indicate severe, lifethreatening disease processes . The pathogenicity of enterococci and the role of vancomycin resistance as a cause of mortality in patients with EPBIs need to be assessed further.

Pediatr Infect Dis J, 1996 Sep, 15(9), 800 - 5
Neonatal enterococcal bacteremia: an increasingly frequent event with potentially untreatable pathogens; McNeeley DF et al.; BACKGROUND: Enterococci can cause serious infections in the newborn . The increased number of these infections since the late 1970s and the increased isolation of organisms resistant to many commonly used antimicrobials prompted review of our experience with enterococcal bacteremia in the neonatal intensive care unit . This review was aimed at defining the character of illness of newborns who had these infections during a 20-year period . METHODS: This was a retrospective review of the medical records of newborns with enterococci isolated from blood . RESULTS: Between January, 1974, and December, 1993, 138 episodes of enterococcal bacteremia occurred in newborns hospitalized in the neonatal intensive care unit . Thirty-four episodes occurred during the first decade and 104 episodes during the second decade . One hundred of the 138 episodes were reviewed . In 64% of these episodes other microorganisms were also isolated from blood . Comparison of clinical characteristics associated with these episodes in the first and second decade demonstrated that episodes occurring in the more recent decade occurred in older infants (mean age of onset, 44.7 vs . 16.1 days; episodes occurring after 14 days, 73% vs . 41%) . Common characteristics associated with enterococcal bacteremia included the presence of a central vascular catheter (77%), necrotizing enterocolitis (33%) and abdominal distension (21%) . Vancomycin-resistant enterococci caused bacteremia in 6 infants and caused illnesses indistinguishable from those caused by susceptible organisms . CONCLUSIONS: In the more recent decade there were three times the number of episodes of enterococcal bacteremia in our neonatal intensive care unit than there were in the previous decade . The characteristics associated with these infections were similar to those occurring with other nosocomial bacterial infections in the neonate and did not change during the period reviewed . Most recent episodes occurred as part of polymicrobial infections in newborns hospitalized for more than 1 month . Infections caused by vancomycin-resistant enterococci occurred in older patients but were clinically indistinguishable from infections caused by sensitive organisms.

Dis Colon Rectum, 1996 Sep, 39(9), 981 - 5
Treatment of perianal infection following bone marrow transplantation; Cohen JS et al.; PURPOSE: Bone marrow transplantation (BMT) is often associated with profound neutropenia . Allogeneic transplant recipients also have defects in both humoral and cellular immunity and thus are subject to increased risk of serious, often life-threatening, infection even beyond the period of granulocyte recovery . The current study was undertaken to evaluate patients who required operative intervention for perianal sepsis following BMT . METHODS: The bone marrow transplant database at a single institution was used to identify all patients diagnosed with perianal infections after autologous or allogeneic BMT . Charts were reviewed in a retrospective manner . RESULTS: Over a ten-year period ending in November 1993, 963 BMT were performed at the City of Hope National Medical Center . Twenty-four patients were diagnosed with perianal infections following their transplants . Fifteen patients did not have purulent collections requiring drainage and were treated with antibiotics and supportive measures alone . Nine patients (37.5 percent) required surgical intervention between 10 and 380 days following transplantation . At the time of surgical intervention, seven patients had purulent collections and two patients had acute and chronic inflammation, tissue necrosis, and fibrosis . Of the two patients with an absolute neutrophil count less than 1,000, a purulent collection was found in one of the patients . Cultures taken from perianal abscesses were almost all polymicrobial, and the most common organisms were Escherichia coli, Bacteroides, Enterococcus, and Klebsiella . For those patients undergoing surgical intervention, mean time to complete wound closure by secondary intention was 37.6 days; five patients healed in less than 15 days, two patients healed at 93 and 114 days, and two patients had persistent, open wounds at time of death, which was unrelated to their perianal disease . Five patients were receiving systemic steroids at time of surgical intervention; this did not appear to affect time to wound healing . CONCLUSIONS: Perianal infections are a rare complication of BMT . Majority of these infections are polymicrobial, and organisms isolated are similar to those seen in the perianal infections of nonimmunosuppressed patients . Despite steroid use, granulocytopenia does not exclude the possible presence of purulent collections, and clinical examination should guide the decision for surgical drainage . In general, perianal wound healing is not prolonged in BMT patients.

J Bacteriol, 1996 Sep, 178(17), 5272 - 8
Evidence that the PBP 5 synthesis repressor (psr) of Enterococcus hirae is also involved in the regulation of cell wall composition and other cell wall-related properties; Massidda O et al.; psr has been reported by M . Ligozzi, F . Pittaluga, and R . Fontana, (J . Bacteriol . 175:2046-2051, 1993) to be a genetic element located just upstream of the structural gene for the low-affinity penicillin-binding protein 5 (PBP 5) in the chromosome of Enterococcus hirae ATCC 9790 and to be involved in the repression of PBP 5 synthesis . By comparing properties of strains of E . hirae that contain a full-length, functional psr with those of strains that possess a truncated form of the gene, we have obtained data that indicate that psr is involved in the regulation of several additional surface-related properties . We observed that cells of strains that possessed a truncated psr were more sensitive to lysozyme-catalyzed protoplast formation, autolyzed more rapidly in 10 mM sodium phosphate (pH 6.8), and, in contrast to strains that possess a functional psr, retained these characteristics after the cultures entered the stationary growth phase . Cellular lytic properties did not correlate with differences in the cellular contents of muramidase-1 or muramidase-2, with the levels of PBP 5 produced, or with the penicillin susceptibilities of the strains . However, a strong correlation was observed with the amounts of rhamnose present in the cell walls of the various strains . All of the strains examined that possessed a truncated form of psr also possessed approximately one-half of the rhamnose content present in the walls of strains that possessed a functional psr . These data suggest that psr is also involved in the regulation of the synthesis of, or covalent linkage to the cell wall peptidoglycan of, a rhamnose-rich polysaccharide . These differences in cell wall composition could be responsible for the observed phenotypic differences . However, the multiple effects of psr suggest that it is part of a global regulatory system that, perhaps independently, affects several cell surface-related properties.

Biochemistry, 1996 Aug 6, 35(31), 9951 - 7
Structure of the native cysteine-sulfenic acid redox center of enterococcal NADH peroxidase refined at 2.8 A resolution; Yeh JI et al.; In order to obtain the crystal structure of the flavoprotein NADH peroxidase with its native Cys42-sulfenic acid redox center, a strategy combining reduced exposure of crystals to ambient oxygen and data collection at -160 degrees C was applied . The structure of the native enzyme to 2.8 A resolution is described; these results conclusively establish the existence of the Cys42-sulfenic acid as the functional non-flavin redox center of the peroxidase and provide the first structure for any naturally occurring protein-sulfenic acid . The Cys42-sulfenic acid atoms C alpha-C beta-S gamma-O roughly define a planar arrangement which is stacked parallel to the si face of the FAD isoalloxazine and positions the sulfenyl oxygen atom only 3.3 A from FAD-C4A . His10-N epsilon 2 contributes a hydrogen bond to the sulfenic acid oxygen, at a distance of 3.2 A . Although one oxygen atom (OX1) of the non-native Cys42-sulfonic acid derivative identified in the earlier wild-type peroxidase structure was taken to represent the native Cys42-sulfenic acid oxygen {Stehle, T., Ahmed, S . A., Claiborne, A., & Schulz, G . E . (1991) J . Mol . Biol . 221, 1325-1344}, this structure shows that the sulfenic acid oxygen does not occupy this position, nor is it hydrogen-bonded to Cys42-N as was OX1 . Comparison of the native Cys42-sulfenic acid structure with that of two-electron reduced glutathione reductase provides an insight into the sulfenic acid FAD charge-transfer interaction observed with both wild-type and His10 mutant peroxidases . A model of the E.NADH intermediate recently observed in stopped-flow analyses of the enzyme {Crane, E . J., III, Parsonage, D., Poole, L . B., & Claiborne, A . (1995) Biochemistry 34, 14114-14124} has also been generated to assist in analyzing the chemical mechanism of sulfenic acid reduction.

Oral Microbiol Immunol, 1996 Aug, 11(4), 259 - 65
Fimbrial-mediated colonization of murine teeth by Actinomyces naeslundii; Beem JE et al.; Groups of mice fed diets high in sucrose or glucose were orally inoculated with 10(10), 10(9) or 10(8) colony-forming units of one of the following Actinomyces naeslundii strains possessing the type 1 (T1+) and/or the type 2 (T2+) fimbriae: T14VJ1 (T1+, T2+), 5519 (T1+), 5951 (T2+), and 147 (non-fimbriated) . Ninety-six hours after inoculation their upper jaws were cultured to look at the implantation of each of these strains on the teeth . In mice fed a sucrose diet, regardless of the presence or absence of fimbriae, each bacterial strain colonized 100% of the mice at the highest inoculation doses of the infecting organism . But at a dose of 10(8), T14V-J1 was the only strain which colonized 100% (12/12) of the mice, 5519 colonized 10/11, 5951 colonized 9/11 and 147 colonized 7/11 . These differences were not statistically significant . When mice were fed a high-glucose diet, 100% infection was achieved with strains T14V-J1, 5519 and 5951 only at the highest dose of 10(10) colony-forming units . Strain 147 colonized in 8/9 of the mice at that dosage . At lower dosages, no bacterial strain implanted in 100% of the mice . In the glucose experiment at a dose of 10(8), strains expressing the T1 fimbriae implanted significantly better than strains without the T1 fimbriae . At a dose of 10(9) colony-forming units, the parent strain T14V-J1 implanted significantly better than strains without the T1 fimbriae . Similarly, strain 5519 (T1+) implanted significantly better than 5951 and implanted better than 147, although the difference was not significant . These results suggest that while the presence of the T1 and T2 fimbriae may confer some advantage in the establishment of these organisms in vivo, even the strains without fimbriae were able to colonize . Strains T14VJ1 and 5519 were found to bind well to hydroxyapatite treated with mouse saliva, while strains 5951 and 147 did not . Only T2 fimbriated strains T14V-J1 and 5951 exhibited a lactose-reversible coaggreation with indigenous strains of enterococci that may contribute to the elevated levels of colonization of strain 5951 in vivo.

AACN Clin Issues, 1996 Aug, 7(3), 403 - 8
Vancomycin-resistant enterococcus: case reviews after transplantation; Dobbin KR et al.; Increased and inappropriate use of vancomycin during the past 35 years has led to the development of vancomycin-resistant enterococcal (VRE) species that are difficult and expensive to treat . This article presents case reviews of patients who experienced vancomycin-resistant enterococcus faecium (VREF) infections during prolonged hospitalizations after transplantation . The risk factors for the development of VRE infection, prevention measures, and the interventions to be implemented once VRE infection is diagnosed are discussed.

J Clin Microbiol, 1996 Aug, 34(8), 2042 - 4
Evaluation of commercial vancomycin agar screen plates for detection of vancomycin-resistant enterococci; Van Horn KG et al.; Brain heart infusion-6-micrograms/ml vancomycin agar plates obtained from five commercial sources (B-D Microbiology Systems, Carr-Scarborough Microbiologicals, MicroBio Products, PML Microbiologicals, and REMEL) were evaluated with 714 enterococci for detection of vancomycin resistance . All 465 (100%) vancomycin-resistant enterococci (MIC > or = 32 micrograms/ml) were detected by each manufacturer's agar screen plate, and each manufacturer's agar screen plate detected at least 99% of the 177 vancomycin-susceptible enterococci (MIC < or = 4 micrograms/ml) . Detection of the 72 vancomycin-intermediate enterococci (MIC = 6 to 16 micrograms/ml) ranged from 94% for B-D Microbiology Systems to 99% for PML Microbiologicals.

Arch Intern Med, 1996 Jul 8, 156(13), 1458 - 62
Bloodstream infections with vancomycin-resistant enterococci; Montecalvo MA et al.; OBJECTIVES . To describe the population in whom bloodstream infections with vancomycin-resistant enterococci occur and the clinical and microbiologic features of infection . METHODS . From June 1, 1991, to January 31, 1994, 73 patients with bloodstream infections with vancomycin-resistant enterococci were identified by retrospective review of hospital charts and microbiology records . RESULTS . Fifty-two (73%) of 71 patients with evaluable data were hospitalized in an intensive care, unit, the adult oncology unit, or the acquired immunodeficiency syndrome unit . Before the development of the bloodstream infection with vancomycin-resistant enterococci, patients were hospitalized and received antibiotics for a median of 26 and 25.5 days, respectively . A hematologic malignancy, respiratory failure, or renal failure requiring dialysis was present in 59 patients (83%) . Acute Physiology and Chronic Health Evaluation II scores of the patients ranged from 6 to 35 (median, 17) . Forty-five (63%) of the patients died . Compared with 37 patients who had only a single positive blood culture, the 34 patients with 2 or more blood cultures positive for vancomycin-resistant enterococci more often were neutropenic or had acquired immunodeficiency syndrome (74% vs 35%; P = .002) . CONCLUSIONS . Bloodstream infections with vancomycin-resistant enterococci predominantly affect severely ill patients who have received extensive antibiotic treatment during a prolonged hospitalization . Immunocompromised patients are more likely to have a persistent blood-stream infection with vancomycin-resistant enterococci.

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