Association between resistance to vancomycin and death in cases of Enterococcus faecium bacteremia.

We conducted a retrospective cohort study to determine the association between resistance to vancomycin and mortality among hospitalized patients with Enterococcus faecium bacteremia. We compared outcomes for patients infected with vancomycin-resistant versus vancomycin-susceptible E. faecium among 69 patients with bacteremia defined according to the National Nosocomial Infections Surveillance system. The univariate odds ratio (OR) for death associated with vancomycin resistance was 2.1 (P=.172). After controlling for severity of illness, we found that vancomycin resistance was not associated with mortality (OR, 1.74; 95% confidence interval, 0.5-6.12; P=.39). Vancomycin resistance does not independently increase mortality among patients with E. faecium bacteremia.     

Inducible resistance to vancomycin in Enterococcus faecium D366

Strain D366, a clinical isolate of Enterococcus faecium, is resistant (minimum inhibitory concentration [MIC] 32 mg/L) to vancomycin. When exponential-phase cultures were exposed to half the MIC of vancomycin, a lag of 3-4 h occurred before growth resumed. Cells preexposed to 1/2 MICs of vancomycin did not show any lag. Pregrowth of D366 with vancomycin caused resistance to all glycopeptides tested. Pregrowth in vancomycin resulted in synthesis of a 3.95-kDa cytoplasmic-membrane-associated protein. This protein was correlated with resistance in mutants with high-level resistance, in the presence of NaCl, which inhibited the activity of vancomycin, and when several glycopeptides with varying activities were tested. Vancomycin-grown cells appeared abnormal and lysed at a much slower rate than did normal cells. We conclude that (1) vancomycin resistance in D366 is inducible; (2) resistance is correlated with the synthesis of 39.5-kDa cytoplasmic membrane protein; and (3) this protein play an additional role in the inhibition of normal lytic functions.     

Infections due to vancomycin-resistant Enterococcus faecium resistant to linezolid

Linezolid is a new oxazolidinone antibiotic used to treat infections caused by vancomycin-resistant enterococci (VRE). In early clinical trials, emergence of resistance occurred rarely. We report clinical details and antibiotic susceptibility from five patients treated with linezolid for VRE infections who had resistant organisms isolated during therapy. Four were transplant patients receiving protracted courses of the drug; three cases were associated with treatment failure. One of 45 linezolid-treated patients developed resistance during therapy. Susceptibility testing should be done in all cases on starting therapy.     

Impact on human intestinal microflora of an Enterococcus faecium probiotic and vancomycin

The aims of this study were to evaluate the impact of a fermented milk product containing viable Enterococcus faecium on human intestinal microflora and to evaluate any risk of development of vancomycin-resistant enterococci (VRE). Twenty Danish and 20 Swedish healthy volunteers were given 150 ml of the fermented milk product once daily, equivalent to a daily dose of 4.5 x 10(9) to 7.5 x 10(9) CFU E. faecium, for 10 d. Half of the volunteers also received 125 mg vancomycin orally q.i.d. for 10 d. Faecal samples were collected on day 0 before intake, on day 10 directly after end of intake and on day 31, 3 weeks after the end of the experiment. There was a significant increase in the total number of enterococci on day 10 (p < 0.01) in the group receiving only the E. faecium supplement, but 3 weeks later the level was as before intake. In the vancomycin group, the total number of enterococci was reduced on day 10 (p < 0.01) but had increased on day 31 (p < 0.01) in relation to day 0. In none of the Swedish and 4 of the Danish volunteers, VRE were sporadically detected, but without relation to intake of the probiotic or vancomycin. In healthy young Danish individuals the VRE carrier rate tended to be higher than previously found.     

Case report vancomycin -resistant Enterococcus faecium VanA phenotype: first documented isolation in India

In recent years, vancomycin-resistant enterococci, especially Enterococcus faecium has emerged as an important nososcomial pathogen and represents a serious threat to patients with impaired host defences. We report infection with vancomycin-resistant Enterococcus faecium in a 3-year-old child with patent ductus arteriosus. The organism, isolated from a central venous catheter tip, exhibited a high-level resistance to vancomycin (minimum inhibitory concentration > or = 256 microg/ ml) and was also resistant to teicoplanin. The child probably died due to sepsis from this highly resistant organism. To the best of our knowledge, this is the first reported isolation of VanA phenotype Enterococcus faecium in India.     

Novel vancomycin resistance gene cluster in Enterococcus faecium ST1486, Belgium,June 2021

We identified a novel van gene cluster in a clinical Enterococcus faecium isolate with vancomycin minimum inhibitory concentration (MIC) of 4 µg/mL. The ligase gene, vanP, was part of a van operon cluster of 4,589 bp on a putative novel integrative conjugative element located in a ca 98 kb genomic region presumed to be acquired by horizontal gene transfer from Clostridium scidens and Roseburia sp. 499. Screening for van genes in E. faecium strains with borderline susceptibility to vancomycin is important.     

Community dissemination of vancomycin-resistant Enterococcus faecium

BACKGROUND AND OBJECTIVE: In the United States, vancomycin-resistant enterococci (VRE) are predominantly acquired in the hospital. The extent of dissemination of VRE into the community in the United States has not been examined. Our objective was to determine the prevalence of VRE among nonhospitalized patients. METHODS: We conducted a cross-sectional surveillance study in an ambulatory care clinic. One hundred ambulatory patients participated in the study. Measurements included a written questionnaire on patient demographics, clinical data, and prior exposure to health care settings and antibiotics; rectal swabs; pulsed-field gel electrophoresis; and polymerase chain reaction genotyping. RESULTS: Three of 100 subjects (3%) were colonized with VRE, including one person who did not have any exposure to a health care setting or antibiotics. CONCLUSIONS: VRE was recovered from nonhospitalized patients. Physicians should be alert to the potential of VRE transmission in the ambulatory care setting.     

Risk Factors for Acute Cholangitis Caused by Enterococcus faecalis and Enterococcus faecium

Background/AimsAcute cholangitis (AC) is a potentially life-threatening bacterial infection, and timely antimicrobial treatment, faster than that achieved with bacterial cultures, is recommended. Although the current guidelines refer to empirical antimicrobial treatment, various kinds of antimicrobial agents have been cited because of insufficient analyses on the spectrum of pathogens in AC. Enterococcus spp. is one of the most frequently isolated Gram-positive bacteria from the bile of patients with AC, but its risk factors have not been extensively studied. This study aimed to analyze the risk factors of AC caused by Enterococcus faecalis and Enterococcus faecium.MethodsPatients with AC who were hospitalized in a Japanese tertiary center between 2010 and 2015 were retrospectively analyzed. Patients’ first AC episodes in the hospital were evaluated.ResultsA total of 266 patients with AC were identified. E. faecalis and/or E. faecium was isolated in 56 (21%) episodes of AC. Prior endoscopic sphincterotomy (EST), the presence of a biliary stent, prior cholecystectomy, and past intensive care unit admission were more frequently observed in AC patients with E. faecalis and/or E. faecium than in those without such bacteria. Prior EST was identified as an independent risk factor for AC caused by E. faecalis and/or E. faecium in the multivariate analysis.ConclusionsGiven the intrinsic resistance of E. faecalis and E. faecium to antibiotics, clinicians should consider empirical therapy with anti-enterococcal antibiotics for patients with prior EST.     

Host specificity of vancomycin-resistant Enterococcus faecium

Amplified-fragment length polymorphism (AFLP) analysis was used to investigate the genetic relationships among 255 vancomycin-resistant Enterococcus faecium (VREF) strains isolated from hospitalized patients, nonhospitalized persons, and various animal sources. Four major AFLP genogroups (A-D) were discriminated. The strains of each taxon shared >/=65% of the restriction fragments. Most isolates recovered from nonhospitalized persons (75%) were grouped together with all pig isolates in genogroup A. Most isolates from hospitalized patients (84%), a subset of veal calf isolates (25%), and all isolates from cats and dogs clustered in genogroup C. Most isolates from chickens (97%) and turkeys (86%) were grouped in genogroup B, whereas most veal calf isolates (70%) clustered in genogroup D. Therefore, VREF strains are predominantly host-specific, and strains isolated from hospitalized patients are genetically different from the prevailing VREF strains present in the fecal flora of nonhospitalized persons.     

临床分离屎肠球菌对8种抗生素的耐药性分析

目的了解广东、河北、甘肃等地临床分离的39株屎肠球菌对8种抗生素的耐药性及产β-内酰胺酶的情况。方法采用纸片琼脂扩散法检测屎肠球菌耐药情况;用头孢硝噻吩法检测屎肠球菌产β-内酰胺酶情况。结果 39株屎肠球菌对红霉素的耐药率最高,达到94.87%,其次是高浓度庆大霉素和青霉素,分别为84.62%和79.48%,环丙沙星的耐药率也达到76.92%,米诺环素为38.46%,而氯霉素则体现出较好的敏感率,其耐药率为17.95%,尚未发现有耐万古霉素及呋喃妥因的菌株,两者耐药率均为0。39株屎肠球菌β-内酰胺酶阳性率为0。汕头地区分离屎肠球菌呈多重耐药性,对青霉素、红霉素、环丙沙星和高浓高度庆大霉素耐药率达100.00%。结论临床分离的屎肠球菌多重耐药性严重,尤其是汕头地区分离的细菌,临床应根据药敏结果合理选用抗感染药物。     

Centromere anatomy in the multidrug-resistant pathogen Enterococcus faecium

Multidrug-resistant variants of the opportunistic human pathogen Enterococcus have recently emerged as leading agents of nosocomial infection. The acquisition of plasmid-borne resistance genes is a driving force in antibiotic-resistance evolution in enterococci. The segregation locus of a high-level gentamicin-resistance plasmid, pGENT, in Enterococcus faecium was identified and dissected. This locus includes overlapping genes encoding PrgP, a member of the ParA superfamily of segregation proteins, and PrgO, a site-specific DNA binding homodimer that recognizes the cenE centromere upstream of prgPO. The centromere has a distinctive organization comprising three subsites, CESII separates CESI and CESIII, each of which harbors seven TATA boxes spaced by half-helical turns. PrgO independently binds both CESI and CESIII, but with different affinities. The topography of the complex was probed by atomic force microscopy, revealing discrete PrgO foci positioned asymmetrically at the CESI and CESIII subsites. Bending analysis demonstrated that cenE is intrinsically curved. The organization of the cenE site and of certain other plasmid centromeres mirrors that of yeast centromeres, which may reflect a common architectural requirement during assembly of the mitotic apparatus in yeast and bacteria. Moreover, segregation modules homologous to that of pGENT are widely disseminated on vancomycin and other resistance plasmids in enterococci. An improved understanding of segrosome assembly may highlight new interventions geared toward combating antibiotic resistance in these insidious pathogens.     

Ciprofloxacin in the treatment of nosocomial multiply resistant Acinetobacter calcoaceticus bacteremia

Summary Twelve cases of multiply resistantAcinetobacter calcoaceticus bacteremia occurred in three intensive care units in three different outbreaks. All patients were mechanically ventilated, on broad spectrum antibiotics and had central lines when bacteremia occurred. The sites of primary infection were: abdominal (n=3); respiratory (n=4); central lines (n=4); CNS (n=1). In eight cases the acinetobacter strains were susceptible to ciprofloxacin only. Four other strains were sensitive to amikacin as well. All 11 patients treated with ciprofloxacin alone (seven) or in combination with amikacin (four) fully recovered from the infection. The 12th patient died before antibiotic susceptibility was available. Ciprofloxacin seems to be an excellent therapeutic agent forA. calcoaceticus infections.

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Ciprofloxacin in der Therapie der nosokomialen Bakteriämie durch multiresistente Acinetobacter calcoaceticus

Zusammenfassung Während drei verschiedener Ausbrüche traten in drei Intensivstationen 12 Fälle von Bakteriämie durch multiresistente Stämme vonAcinetobacter calcoaceticus auf. Als die Bakteriämie auftrat, wurden alle diese Patienten künstlich beatmet, erhielten Breitspektrumantibiotika und hatten zentrale Gefäßkatheter. In drei Fällen war die Primärinfektion im Abdomen, in vier Fällen in den Atemwegen lokalisiert, viermal handelte es sich um Katheterinfektionen und einmal um eine ZNS-Infektion. In acht Fällen waren die Acinetobacter-Stämme nur gegen Ciprofloxacin empfindlich. Bei vier Stämmen bestand auch Empfindlichkeit gegen Amikacin. Alle mit Ciprofloxacin allein (sieben) oder in Kombination mit Amikacin (vier) behandelten Patienten erholten sich vollständig von ihrer Infektion. Der 12. Patient starb bevor die Resistenztestung vorlag. Ciprofloxacin ist offensichtlich ein ausgezeichnetes Therapeutikum zur Behandlung von Infektionen durchA. calcoaceticus.

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This work was presented in part at the Congress of Infectious Diseases, Rio de Janeiro, Brazil, April 1988.