Vancomycin-resistant Enterococci Isolates Research Articles

1009. Venous 1: A Prospective Multicenter Cohort Study of Enterococcal Bacteremia

BackgroundEnterococci often cause hospital-associated bloodstream infections in critically ill and immunocompromised patients. Prospective studies to assess the clinical impact of enterococcal bacteremia (EB) are lacking. We conducted a prospective study to investigate the clinical and microbiological factors associated with mortality in EB.MethodsAdults with EB were prospectively followed in three US tertiary hospitals from September 2016 to March 2018. Individuals with EB for whom follow-up blood culture data within 7 days of index culture were available were included. Microbiologic failure (MF) was defined as clearance of bacteremia ≥4 days after the first blood culture. The main outcome was hospital mortality.ResultsA total of 282 patients were included with 69 (24%) infected with vancomycin-resistant enterococci (VRE). The majority of patients were male (60%) with a median age of 63 years. Median length of hospitalization for VRE patients was longer (25 d) than non-VRE (13 days, P < 0.001). E. faecium corresponded to 77% of VRE isolates, whereas E. faecalis comprised 72% of non-VRE. The average time to first blood culture was 16 days for VRE vs. 4 days for non-VRE (P < 0.001). Patients with VRE were more likely to have hematological malignancy or bone marrow transplant (P < 0.003), whereas patients infected non-VRE were more likely to have solid tumors (P = 0.02). The most common antibiotic used was daptomycin as monotherapy for both VRE and non-VRE with a median dose of 8 mg/kg for both groups. Overall mortality was 25% (43% vs. 20% in VRE vs. non-VRE patients, respectively; P < 0.0001). Factors significantly associated with mortality in univariate analyses included ICU admission, prolonged hospitalization, hematological malignancy, use of immunosuppressive therapy, hemodialysis, neutropenia (<500 cell/mL), Pitt bacteremia score >3, infection with VRE and MF. ICU admission (RR 3.3; 95% CI 1.7–7.5, neutropenia (RR 4.1; 95% CI 1.3–12.9), Pitt bacteremia score >3 (RR 6.8; 95% CI 2.6–18.0), MF (RR 4.7; 95% CI 2.2–10.3) and infection with VRE (RR 4.1; 95% CI 1.1–16.6) remained significantly associated with mortality in multivariate analyses.ConclusionThe presence of VRE in EB and MF are associated with increased mortality. EB represent a major burden of disease in hospital settings.Disclosures C. Arias, Merck & Co., Inc.: Grant Investigator, Research support. MeMed: Grant Investigator, Research support. Allergan: Grant Investigator, Research support.

Isolation and molecular characterization of enterococci from different animal species

The study was undertaken to determine the occurrence of Enterococcus spp. with special reference to vancomycin resistant enterococci (VRE) in bovines, equines and poultry; detection of vancomycin resistance gene markers by polymerase chain reaction (PCR) and to compare VRE isolates by means of pulse field gel electrophoresis (PFGE). In this study, 60 VRE were isolated from 150 faecal samples. Besides vancomycin sensitivity, isolates were also tested for 6 more antimicrobial drugs by MIC. Significant number of isolates exhibited intermediate level of resistance to vancomycin (70%), norfloxacin (50%) and cephalothin (43.3%). Multidrug resistance (MDR) was observed in 37 (61.6%) isolates. Multiplex PCR revealed vanC1 (14), vanC2/3 (9), van C1 + vanC2/3 (11) but no vanA or vanB genes. Further genotyping of the VRE isolates carrying vanC genes using pulse field gel electrophoresis revealed ~73% homology.

Prevalence of vancomycin resistance among isolates of enterococci in Iran: a systematic review and meta-analysis.

IntroductionEnterococcus is responsible for 10% of hospital-acquired infections. The purpose of this review was to evaluate the prevalence of vancomycin-resistant Enterococcus (VRE) isolates in Iran using a meta-analysis method.Materials and methodsIranian databases, including Magiran and IranDoc, and international databases, including PubMed and MedLib, were examined carefully, and a total of 20 articles published between 2000 and 2011 were extracted. The data were subjected to meta-analysis and random-effects models. In addition, heterogeneous studies were assessed using the I2 index. Finally, the data were analyzed using R and STATA software.ResultsThe results showed that the strain of Enterococcus faecalis had been more common than Enterococcus faecium in clinical infection (69% vs 28%). However, resistance to vancomycin was higher among strains of E. faecium compared with strains of E. faecalis (33% vs 3%). The complete resistance, intermediate resistance, and sensitivity to vancomycin among Enterococcus isolates were 14% (95% CI: 11, 18), 14% (95% CI: 5, 23), and 74% (95% CI: 65, 83), respectively. The resistance patterns, depending on the sample type, did not show a significant difference. In addition, the resistance of isolated strains to vancomycin in outpatients was significantly higher than that in inpatients (16% vs 1%). Moreover, 80%–86% of resistant strains were genotype van A and 14%–20% of resistant strains were genotype van B.ConclusionThe findings of the present review show that there is a high frequency of resistant Enterococcus in Iran. Therefore, consideration of the prevalence and frequency of subjected resistant strains can be helpful for decision makers to implement proper health policies in this direction.

Overview of Prevalence, Characteristics, Risk Factors, Resistance, and Virulence of Vancomycin-Resistant Enterococci in Saudi Arabia.

Vancomycin-resistant enterococci (VRE) are Gram-positive bacteria that are resistant to vancomycin. Infections caused by VRE are associated with adverse outcomes such as extended length of hospital stay, increased cost, and high mortality rate. Clinical and surveillance VRE isolates have been reported from Saudi Arabia. In this review, prevalence, characteristics, risk factors, resistance, and virulence of VRE isolates associated with infection and colonization in Saudi Arabia are described.

Mathematical modelling of vancomycin-resistant enterococci transmission during passive surveillance and active surveillance with contact isolation highlights the need to identify and address the source of acquisition

BackgroundClinical studies and mathematical simulation suggest that active surveillance with contact isolation is associated with reduced vancomycin-resistant enterococci (VRE) prevalence compared to passive surveillance. Models using pre- and post-intervention data that account for the imperfect observation and serial dependence of VRE transmission events can better estimate the effectiveness of active surveillance and subsequent contact isolation; however, such analyses have not been performed.MethodsA mathematical model was fitted to surveillance data collected pre- and post-implementation of active surveillance with contact isolation in the haematology-oncology ward. We developed a Hidden Markov Model to describe undetected and observed VRE colonisation/infection status based on the detection activities in the ward. Bayesian inference was used to estimate transmission rates. The effectiveness of active surveillance was assumed to be via increased detection and subsequent contact isolation of VRE positive patients.ResultsWe estimated that 31% (95% credible interval: 0.33–85%) of the VRE transmissions were due to cross-transmission between patients. The ratio of transmission rates from patients with contact isolation versus those without contact isolation was 0.33 (95% credible interval: 0.050–1.22).ConclusionsThe majority of the VRE acquisitions in the haematology-oncology ward was estimated to be due to background rates of VRE, rather than within ward patient to patient acquisition. The credible interval for cross-transmission was wide which results in a large degree of uncertainty in the estimates. Factors that could account for background VRE acquisition include endogenous acquisition from antibiotic selection pressure and VRE in the environment. Contact isolation was not significantly associated with reduced VRE transmission in settings where the majority of VRE acquisition was due to background acquisition, emphasising the need to identify and address the source of acquisition. As the credible interval for the ratio of VRE transmission in contact isolated versus non-contact isolated patients crossed 1, there is a probability that the transmission rate in contact isolation was not lower. Our finding highlights the need to optimise infection control measures other than active surveillance for VRE and subsequent contact isolation to reduce VRE transmission. Such measures could include antimicrobial stewardship, environmental cleaning, and hand hygiene.

Enterococcus spp. in Ragusano PDO and Pecorino Siciliano cheese types: A snapshot of their antibiotic resistance distribution

In the present study, 110 enterococci were isolated from two Sicilian cheese types, Ragusano PDO and Pecorino Siciliano. Isolates, firstly identified by MALDI-TOF/MS and a multiplex PCR assay, were tested for susceptibility to the most relevant clinical antibiotics. Clonal relationships among isolates were evaluated by pulsed-field-gel electrophoresis (PFGE) analysis and the presence of vanA and vanB genes, in vancomycin resistant enterococci (VRE), was investigated. Overall, E. faecalis, E. durans (35% for each species) and E. faecium (28%) were the major identified species. Different occurrence between cheese types was revealed. Most isolates from Ragusano PDO cheese were identified as E. durans (46%) and/or E. faecalis (43%), while E. faecium (605) was mainly detected in Pecorino Siciliano cheese. High incidence of resistance (97% of total strains) was detected for rifampicin, erythromycin and ampicillin. Moreover, 83 isolates (75%) exhibited multidrug-resistant phenotypes and the one VRE (vanB) isolate was identified as E. durans. PFGE analysis clustered isolates into 22 genotypes and the presence of the same PFGE types, for both E. durans and E. faecalis, in the two cheese types, suggest the link between enterococci and geographical area of production. Results of present study raise concerns about possible role of dairy enterococci as reservoirs of antibiotic resistance.

Outbreak of vancomycin-resistant Enterococcus faecium clone ST796, Switzerland, December 2017 to April 2018.

A large outbreak of vancomycin-resistant enterococci (VRE) is affecting four hospitals in the Canton of Bern, Switzerland, since December 2017. Of 89 cases identified as carriers, 77 (86.5%) VRE isolates were virtually indistinguishable using whole genome sequencing, and identified as multilocus sequence type (MLST) ST796. This clone, previously only described in Australia and New Zealand, is characterised by rapid spread and the ability to cause bloodstream infections. It requires a multifaceted infection prevention effort.

Presence of the esp gene in Enterococcus faecium derived from oropharyngeal microbiota of haematology patients

ObjectivesAntibiotic use and immunocompromised status in haematology patients have been shown to determine the constituents of commensal microbiota with highly increased resistance, including vancomycin resistant enterococci. We compared the carriage of virulence factor genes and the capacity for biofilm formation in vancomycin resistant enterococci (VRE) originating from the oropharyngeal and stool cultures of haematology patients. DesignPCR tests were used to investigate the presence of genes encoding pathogenicity factors (esp and hyl) in VRE isolates. The genotype of vancomycin resistance was investigated by multiplex PCR tests for vanA and vanB genes. PFGE typing was conducted to exclude the duplicate isolates. ResultsOf 3310 pharyngeal swabs taken from inpatients at a clinic for haematology, Enterococcus species were recovered in 6.46%. All VRE investigated were identified as Enterococcus faecium and were highly vancomycin resistant. VanA genotype was confirmed in all. In the group of oropharyngeal carriers (n = 8 patients), 15 strains were recovered from oropharyngeal specimens and PFGE typing revealed 5 types and 3 subtypes. Identical types of VRE in the oropharynx and stool cultures were found in three patients from this group. In the group of stool carriers (n = 24 patients) VRE were obtained from stools only and placed in 21 macro-restriction patterns. The esp gene was more common in VRE isolated from the oropharynx than in isolates from stools (p = 0.014). Results were not significant when we compared the presence of hyl genes in oropharyngeal isolates with those from stool cultures (p = 0.66) or when we investigated the association between esp and hyl gene carriage and capability of biofilm formation in non-repeated VRE. ConclusionsIn the present study, isolation of VRE from the oropharynx in haematology patients was associated with esp gene carriage. Further research is needed to investigate the clinical and long-term effects of this finding.

Occurrence of bacteria with a dangerous extent of antibiotic resistance in poultry in the Central Region of Moravia

The study aimed to determine the occurrence ofEnterobacteriaceaeproducing broad-spectrum beta-lactamases, vancomycin-resistant enterococci (VRE) and methicillin-resistantStaphylococcus aureusstrains in poultry in Moravia, Czech Republic, including phenotypic and genotypic analyses of the extent of resistance. Using chromogenic screening media, a total of 240 clinical samples collected from poultry and the poultry farm environment were processed. Phenotypic tests identified 23 isolates of broad-spectrum beta-lactamase-producingEscherichia coliand one VRE isolate (Enterococcus faeciumwith VanA resistance). Methicillin-resistantStaphylococcus aureusstrains were not detected. Among the isolates producing broad-spectrum beta-lactamases, 17 produced extended-spectrum beta-lactamases, most frequently CTX-M; the remaining 6 isolates were CIT-type AmpC enzymes. No carbapenemase-producing strains were detected. Pulsed-field gel electrophoresis showed that 21E. colistrains (91%) were genetically unrelated isolates. Increasing resistance of bacteria to antibiotic agents poses a serious issue for both human and veterinary medicine globally. For humans, a potential source of resistant bacteria may be animals or their products entering the human food chain, for example poultry. The presented study extends existing knowledge about the occurrence of resistant bacteria in poultry in Moravia and describes the phenotype and genotype of their resistance to antibiotics.

The Path to New Halogenated Quinolines With Enhanced Activities Against Staphylococcus epidermidis.

Antibiotic-resistant bacteria and surface-attached bacterial biofilms play a significant role in human disease. Conventional antibiotics target actively replicating free-floating, planktonic cells. Unfortunately, biofilm communities are endowed with nonreplicating persister cells that are tolerant to antibiotics. Innovative approaches are necessary to identify new molecules able to eradicate resistant and tolerant bacterial cells. Our group has discovered that select halogenated quinolines (HQs) can eradicate drug-resistant, gram-positive bacterial pathogens and their corresponding biofilms. Interestingly, the HQ scaffold is synthetically tunable and we have discovered unique antibacterial profiles through extensive analogue synthesis and microbiologic studies. We recently reported the synthesis of 14 new HQs to investigate the impact of ClogP values on antibacterial and biofilm eradication activities. We conducted diverse synthetic modifications at the 2-position of the HQ scaffold in an attempt to enhance water solubility and found new compounds that display enhanced activities against Staphylococcus epidermidis. In particular, HQ 2 (ClogP = 3.44) demonstrated more potent antibacterial activities against methicillin-resistant S epidermidis (MRSE) 35984 planktonic cells (minimum inhibitory concentration = 0.59 µM) compared with methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus isolates while demonstrating potent MRSE biofilm eradication activities (minimum biofilm eradication concentration = 2.35 µM). We believe that HQ could play a critical role in the development of next-generation antibacterial therapeutics.

Vancomycin-Resistant Enterococci (VRE) in The Intensive Care Unit in a Nonoutbreak Setting: Identification of Potential Reservoirs and Epidemiological Associations Between Patient and Environmental VRE

OBJECTIVE Among nosocomial bloodstream infections caused by enterococcal species, Ireland has the highest proportion caused by vancomycin-resistant enterococci (VRE) in Europe at 45.8%. The contribution of the near-patient environment to VRE transmission outside of outbreaks was investigated. DESIGN A prospective observational study was conducted during 7 sampling periods. METHODS Recovery of VRE isolates by swabbing the near-patient environment and patients in the intensive care unit (ICU) was conducted to identify reservoirs, clinical and molecular epidemiological associations, and the success of active surveillance cultures (ASCs). RESULTS Of 289 sampling occasions involving 157 patients and their bed spaces, VRE isolates were recovered from patient bed spaces, clinical samples, or both on 114 of 289 sampling occasions (39.4%). The patient and their bed space were positive for VRE on 34 of 114 VRE-associated sampling occasions (29.8%). Of 1,647 environment samples, 107 sites (6.5%) were VRE positive, with significantly greater VRE recovery from isolation rooms than from the open-plan area (9.1% vs 4.1%; P < .0001). The most frequently VRE-contaminated sites were the drip stand, bed control panel, and chart holders, which together accounted for 61% of contaminated sites. The use of ASCs resulted in a 172% increase in identification of VRE-colonized patients. Molecular typing revealed 2 environmental clusters, 1 cluster involving 3 patients and generally greater heterogeneity of patient isolates compared to environmental isolates. CONCLUSION Even outside of outbreaks, near-patient ICU environmental contamination with VRE is common. Better infection control policies that limit environmental transmission of VRE in the ICU and that are supported by molecular epidemiological studies, in real time, are needed. Infect Control Hosp Epidemiol 2018;39:40-45.

Rapid monitoring of vancomycin-resistant Enterococcus faecium in hospital departments by repetitive element palindromic polymerase chain reaction

The current increase in nosocomial infections caused by vancomycin-resistant enterococci (VRE) warrants improvement of detection methods and hygiene measures. Knowledge of the local epidemiology is important for monitoring compliance of medical personnel with hygiene measures. To evaluate semi-automated repetitive element palindromic polymerase chain reaction (rep-PCR) for rapid molecular typing of VRE. Primary VRE isolates were collected during an observation period of one year and retrospectively typed by rep-PCR. Molecular typing was performed on isolates from two departments with elevated VRE rates and patients with increased risk for systemic VRE infections. Typing results were correlated with temporal and spatial information on patient moves, VRE laboratory results and multi-locus sequence typing (MLST). Approximately 70% of VRE isolates within a department could be assigned to similarity clusters. Spread of VRE was limited to the individual departments. There was no evidence for spread of endemic VRE strains within the geographical catchment area of the hospital. Our results demonstrate the utility of rep-PCR typing on a department level. However, a Diversilab® threshold of ≥98% had to be applied to claim similarity, and suspected transmissions needed to be confirmed by vanA/B genotyping and compiled information on spatial and temporal patient contact. MLST verified the findings. Spread of predominantly detected vancomycin-resistant Enterococcus faecium was limited to the department level with no evidence for wider dissemination within the hospital. Well-standardized and validated (semi-)automated rep-PCR systems are useful for rapid detection of possible VRE transmission. However, suspected transmissions need to be confirmed by clinical and microbiological parameters.

A novel bacteriocin from Enterococcus faecalis 478 exhibits a potent activity against vancomycin-resistant enterococci.

The emergence of multidrug-resistant enterococci (MDRE) and particularly vancomycin-resistant enterococci (VRE) is considered a serious health problem worldwide, causing the need for new antimicrobials. The aim of this study was to discover and characterize bacteriocin against clinical isolates of MDRE and VRE. Over 10,000 bacterial isolates from water, environment and clinical samples were screened. E. faecalis strain 478 isolated from human feces produced the highest antibacterial activity against several MDRE and VRE strains. The optimum condition for bacteriocin production was cultivation in MRS broth at 37°C, pH 5–6 for 16 hours. The bacteriocin-like substance produced from E. faecalis strain EF478 was stable at 60°C for at least 1 hour and retained its antimicrobial activity after storage at -20°C for 1 year, at 4°C for 6 months, and at 25°C for 2 months. A nano-HPLC electrospray ionization multi-stage tandem mass spectrometry (nLC-ESI-MS/MS) analysis showed that the amino acid sequences of the bacteriocin-like substance was similar to serine protease of E. faecalis, gi|488296663 (NCBI database), which has never been reported as a bacteriocin. This study reported a novel bacteriocin with high antibacterial activity against VRE and MDRE.

Genetic characteristics and molecular epidemiology of vancomycin-resistant Enterococci isolates from Caribbean countries

Emergence of vancomycin-resistant Enterococci (VRE) that first appeared on the stage about three decades ago is now a major concern worldwide as it has globally reached every continent. Our aim was to simply undertake a multinational study to delineate the resistance and virulence genes of clinical isolates of VRE isolates from the Caribbean. We employed both conventional (standard microbiological methods including use of E-test strips, chromogenic agar) and molecular methods (polymerase chain reactions–PCR, pulsed-field gel electrophoresis–PFGE and multilocus sequence typing–MLST) to analyze and characterize 245 Enterococci species and 77 VRE isolates from twelve hospitals from eight countries in the Caribbean. The PCR confirmed and demonstrated the resistance and virulence genes (vanA and esp) among all confirmed VRE isolates. The PFGE delineated clonally related isolates from patients from the same country and other countries in the region. The main sequence types of the VRE isolates from the region included STs 412, 750, 203, 736 and 18, all from the common ancestor for clonal complex 17 (CC17). Despite this common ancestor and association of outbreaks of this lineage clones, there has been no reports of outbreaks of infection by VRE in several hospitals in the Caribbean.

Epidemiology of Extended-Spectrum β-Lactamase-Producing E. coli and Vancomycin-Resistant Enterococci in the Northern Dutch-German Cross-Border Region.

Objectives: To reveal the prevalence and epidemiology of extended-spectrum β-lactamase (ESBL)- and/or plasmid AmpC (pAmpC)- and carbapenemase (CP) producing Enterobacteriaceae and vancomycin-resistant enterococci (VRE) across the Northern Dutch–German border region.Methods: A point-prevalence study on ESBL/pAmpC/CP producing Enterobacteriaceae and VRE was carried out in hospitalized patients in the Northern Netherlands (n = 445, 2012–2013) and Germany (n = 242, 2012). Healthy individuals from the Dutch community (n = 400, 2010–2012) were also screened. In addition, a genome-wide gene-by-gene approach was applied to study the epidemiology of ESBL-Escherichia coli and VRE.Results: A total of 34 isolates from 27 patients (6.1%) admitted to Dutch hospitals were ESBL/pAmpC positive and 29 ESBL-E. coli, three pAmpC-E. coli, one ESBL-Enterobacter cloacae, and one pAmpC-Proteus mirabilis were found. In the German hospital, 18 isolates (16 E. coli and 2 Klebsiella pneumoniae) from 17 patients (7.7%) were ESBL positive. In isolates from the hospitalized patients CTX-M-15 was the most frequently detected ESBL-gene. In the Dutch community, 11 individuals (2.75%) were ESBL/pAmpC positive: 10 ESBL-E. coli (CTX-M-1 being the most prevalent gene) and one pAmpC E. coli. Six Dutch (1.3%) and four German (3.9%) hospitalized patients were colonized with VRE. Genetic relatedness by core genome multi-locus sequence typing (cgMLST) was found between two ESBL-E. coli isolates from Dutch and German cross-border hospitals and between VRE isolates from different hospitals within the same region.Conclusion: The prevalence of ESBL/pAmpC-Enterobacteriaceae was similar in hospitalized patients across the Dutch–German border region, whereas VRE prevalence was slightly higher on the German side. The overall prevalence of the studied pathogens was lower in the community than in hospitals in the Northern Netherlands. Cross-border transmission of ESBL-E. coli and VRE seems unlikely based on cgMLST analysis, however continuous monitoring is necessary to control their spread and stay informed about their epidemiology.

Comparative Effectiveness of Vancomycin vs. Metronidazole in Mild Clostridium difficile Infections, and Potential Impact on Subsequent Vancomycin-Resistant Enterococcus (VRE) Isolation

BackgroundThe epidemiology and clinical characteristics of Clostridium difficile infections (CDI) have evolved dramatically in the past decade. Vancomycin is the treatment of choice for moderate to severe CDI, with superior cure rates observed in comparative trials. However, controlled comparative efficacy data pertaining to mild CDI is lacking. Furthermore, the potential impact of vancomycin treatment on subsequent Vancomycin-Resistant Enterococcus (VRE) isolation rates remains unknown at the individual patient level.MethodsA Retrospective cohort analysis was executed at the Assaf Harofeh Medical Center, Israel, from 2010 to 2015. Adult patients (>18 years) with a first episode of acute CDI, determined per pre-established criteria, were enrolled. The efficacy of vancomycin vs..metronidazole was evaluated in the subset of patients with mild CDI. The outcomes of patients, who received vancomycin or metronidazole (but not both), were compared by Cox regression. A prediction score was used to control for possible confounders associated with being treated with vancomycin. The independent association of oral vancomycin treatment during the acute CDI and later (up to 18 months) VRE isolation was analyzed using Cox regression.ResultsA total of 413 patients with CDI were included in the study. The majority were elderly (median age 75 years, range 19–120), and had extensive comorbidities (mean Charlson’s combined condition score 6.7 ± 3.4) and significant acute illness indices (35% with severe to fulminant Horn index). Among 126 patients with mild disease, no differences were observed in terms of clinical outcomes between vancomycin or metronidazole treatment. Metronidazole remained non-inferior even after incorporating a prediction score to control for confounders associated with being a “vancomycin case”. Ten patients had new post-CDI VRE isolation. In multivariable analysis, oral vancomycin treatment during the acute CDI was the strongest independent predictor for later isolation of VRE (aOR=6.7, P = 0.04).ConclusionOur study suggests that metronidazole should remain the recommended treatment of choice for mild CDI, due to clinical non-inferiority and an apparent association between vancomycin therapy and subsequent VRE isolation on an individual patient level analysis.Disclosures All authors: No reported disclosures.

Decrease in Vancomycin-Resistant Enterococcus Colonization After Extensive Renovation of a Unit Dedicated to the Treatment of Hematologic Malignancies and Hematopoietic Stem-Cell Transplantation.

OBJECTIVE While a direct relation between hospital construction and concomitant infection rates has been clearly established, few data are available regarding the environmental decontamination effects of renovation in which surfaces are replaced and regarding subsequent infection incidence. DESIGN Retrospective clinical study with vancomycin-resistant Enterococcus (VRE) molecular strain typing and environmental cultures. SETTING A regional referral center for acute leukemia and hematopoietic stem-cell transplantation. PATIENTS Overall, 536 consecutive hospital admissions for newly diagnosed acute leukemia or a first autologous or allogeneic stem-cell transplantation were reviewed. INTERVENTION During 2009-2010, our unit underwent complete remodeling including replacement of all surfaces. We assessed the effects of this construction on the incidence of hospital-acquired VRE colonization before, during, and after the renovation. RESULTS We observed a sharp decrease in VRE colonization rates (hazard ratio, <0.23; 95% confidence interval, 0.18-0.44; P<.0001) during the first year after the renovation, with a return to near baseline rates thereafter. The known risk factors for VRE colonization appeared to be stable over the study interval. Environmental cultures outside of patient rooms revealed several contaminated areas that are commonly touched by unit personnel. Multilocus sequence typing of VRE isolates that were cryopreserved over the study interval showed that dominant strains prior to construction disappeared and were replaced by other strains after the renovation. CONCLUSIONS Unit reconstruction interrupted endemic transmission of VRE, which resumed with novel strains upon reopening. Contamination of environmental surfaces and shared equipment may play an important role in endemic transmission of VRE. Infect Control Hosp Epidemiol 2017;38:1055-1061.

Linezolid activity against clinical Gram-positive cocci with advanced antimicrobial drug resistance in Iran.

The aim of the study was to investigate the linezolid activity against clinical Gram-positive cocci with advanced antimicrobial drug resistance. A collection of methicillin resistant Staphylococcus aureus (MRSA), vancomycin resistant enterococci (VRE), penicillin non-susceptible Streptococcus pneumoniae (PNSP), and group B streptococci (GBS) were isolated from various clinical samples. Antimicrobial susceptibility tests were done using standard methods Subsequently, we investigated linezolid antibacterial activities, the first approved oxazolidinone against isolates by the standard broth microdilution method. According to our results, MRSA and PNSP isolates were multidrug resistant, and almost half of the VRE isolates were high level gentamicin resistant (HLGR). Furthermore, resistance to linezolid was not seen among the isolates. The MIC90 values for MRSA, VRE, PNSP and GBS isolates were 4μg/ml, 2μg/ml, 1μg/ml, and 0.5μg/ml, respectively. Only 6.25% of vancomycin resistant enterococci showed intermediate susceptibility to this antibiotic. These findings indicate that linezolid has an excellent activity against clinical drug resistant Gram-positive isolates in Iran. Constant monitoring and surveillance of linezolid MIC distribution allows the researchers to assess and detect gradual upward MIC drifts.

Intestinal Colonization of Vancomycin-Resistant Enterococci Isolates among Patients in an Iranian Hospital

Vancomycin-resistant enterococci (VRE) remain as one of the important cause of nosocomial infections. Reports of the VRE carriers are increasing worldwide. In this study, a total of 220 patients was screened for vancomycin-resistant enterococci colonization, of which 36 (16.3) were VRE carriers. Among the VRE isolates, 17 were vanA positive. The distribution of VRE carriers in different wards that pose high risks for healthcare infection to hospitalized patients emphasizes applying suitable infection control strategies to prevent the dissemination of the organism. This is the first report from Iran in which a vanA-containing enterococci were isolated from intestinal colonization of patients. Strict measures are required to control the further spread of VRE strains in the Iranian patients.

Ampicillin for the treatment of complicated urinary tract infections caused by vancomycin–resistant Enterococcus spp (VRE): a single-center university hospital experience

Vancomycin-resistant enterococci (VRE) are a common cause of urinary tract infections (UTIs) and are typically multidrug resistant, including ampicillin. This retrospective study evaluated outcomes of 84 adult patients hospitalized between January 2007 and December 2015 with ampicillin– and vancomycin–resistant enterococcus isolates causing UTI and treated with ampicillin. Treatment response was classified as clinical cure and microbiological eradication. Clinical cure was achieved in 88.1% (74/84) of patients. In patients with follow–up cultures, microbiological eradication was achieved in 86% (50/58) of patients. Cure rates were similar in patients with indwelling urinary catheters (n = 45) receiving catheter exchange/removal (90.47%; 19/21) versus catheter retention (87.5%; 21/24). Presence of co–morbidities, such as diabetes and chronic kidney disease, were not associated with increased risk of treatment failure. Immunocompromised patients achieved lower cure rates of 78.1% (25/32) compared with 94.2% (49/52) among those without immune impairment (P = 0.038). Presence of an underlying urinary tract abnormality was also associated with a lower cure rate of 71.4% (15/21) compared with 93.7% (59/63) in those without urinary tract abnormalities (P = 0.0135). Overall cure rates remained high in all groups providing good evidence to support ampicillin for the treatment of complicated UTI caused by ampicillin– and vancomycin–resistant enterococci.