Fiona Boyle

Enumeration and Characterization of Antimicrobial-Resistant Escherichia coli Bacteria in Effluent from Municipal, Hospital, and Secondary Treatment Facility Sources

ABSTRACT We describe a modification of the most probable number (MPN) method for rapid enumeration of antimicrobial-resistant Escherichiacoli bacteria in aqueous environmental samples. E. coli (total and antimicrobial-resistant) bacteria were enumerated in effluent samples from a hospital (n = 17) and municipal sewers upstream (n = 5) and downstream (n = 5) from the hospital, effluent samples from throughout the treatment process (n = 4), and treated effluent samples (n = 13). Effluent downstream from the hospital contained a higher proportion of antimicrobial-resistant E. coli than that upstream from the hospital. Wastewater treatment reduced the numbers of E. coli bacteria (total and antimicrobial resistant); however, antimicrobial-resistant E. coli was not eliminated, and E. coli resistant to cefotaxime (including extended-spectrum beta-lactamase [ESBL] producers), ciprofloxacin, and cefoxitin was present in treated effluent samples.

Production of KPC-2 Carbapenemase by an Escherichia coli Clinical Isolate Belonging to the International ST131 Clone

The rapid international dissemination of Klebsiella pneumoniae carbapenemase (KPC)-producing organisms is of major concern. Of the 13 variants of KPC described to date, KPC-2 is the most widely reported and disseminated. KPC-producing isolates of K. pneumoniae have reached epidemic proportions in

Inter-hospital outbreak of Klebsiella pneumoniae producing KPC-2 carbapenemase in Ireland

OBJECTIVES To describe an outbreak of KPC-2-producing Klebsiella pneumoniae with inter-hospital spread and measures taken to control transmission. METHODS Between January and March 2011, 13 K. pneumoniae isolates were collected from nine patients at hospital A and two patients at hospital B. Meropenem, imipenem and ertapenem MICs were determined by Etest, carbapenemase production was confirmed by the modified Hodge method and by a disc synergy test, and confirmed carbapenemase producers were tested for the presence of carbapenemase-encoding genes by PCR. PFGE, plasmid analysis, multilocus variable-number tandem-repeat analysis (MLVA) and multilocus sequence typing (MLST) analysis were performed on all or a subset of isolates. RESULTS Meropenem, imipenem and ertapenem MICs were 4 to >32, 8-32 and >16 mg/L, respectively. PCR and sequencing confirmed the presence of bla(KPC-2). PFGE identified four distinguishable (≥88%) pulsed-field profiles (PFPs). Isolates distinguishable by PFGE had identical MLVA profiles, and MLST analysis indicated all isolates belonged to the ST258 clone. Stringent infection prevention and control measures were implemented. Over a period of almost 8 months no further carbapenemase-producing Enterobacteriaceae (CPE) were isolated. However, KPC-2-producing K. pneumoniae was detected in two further patients in hospital A in August (PFP indistinguishable from previous isolates) and October 2011 (PFP similar to but distinguishable from previous isolates). CONCLUSIONS Stringent infection prevention and control measures help contain CPE in the healthcare setting; however, in the case of hospital A, where CPE appears to be established in the population served, it may be virtually impossible to achieve eradication or avoid reintroduction into the hospital.

Increasing prevalence of ESBL production among Irish clinical Enterobacteriaceae from 2004 to 2008: an observational study

BackgroundExtended spectrum β-lactamase (ESBL) producing Enterobacteriaceae infections are associated with delayed initiation of appropriate treatment, poor outcomes and increased hospital stay and expense. Although initially associated with healthcare settings, more recent international reports have shown increasing isolation of ESBLs in the community. Both hospital and community ESBL epidemiology in Ireland are poorly defined.MethodsThis report describes clinical and laboratory data from three hospitals over 4.5 years. All significant isolates of Enterobacteriaceae were subjected to standardized antimicrobial susceptibility testing and screening for ESBL production. Available patient data from hospital databases were reviewed.ResultsThe database included 974 ESBL producing organisms from 464 patients. Urine and blood isolates represented 84% and 3% of isolates respectively. E. coli predominated (90.9%) followed by K. pneumoniae (5.6%). The majority of patients (n = 246, 53.0%) had been admitted to at least one of the study hospitals in the year prior to first isolation of ESBL. The overall 30-day all-cause mortality from the date of culture positivity was 9.7% and the 1 year mortality was 61.4%. A Cox regression analysis showed age over 60, male gender and previous hospital admissions were significant risk factors for death within 30 days of ESBL isolation. Numbers of ESBL-producing E. coli isolated from urine and blood cultures increased during the study. Urine isolates were more susceptible than blood isolates. Co-resistance to other classes of antimicrobial agents was more common in ESBL producers from residents of long stay facilities (LSF) compared with hospital inpatients who lived at home.ConclusionsThis work demonstrates a progressively increasing prevalence of ESBL Enterobacteriaceae in hospital, LSF and community specimens in a defined catchment area over a long time period . These results will improve clinician awareness of this problem and guide the development of empiric antimicrobial regimens for community acquired bloodstream and urinary tract infections.

Enterococcus faecium of the vanA Genotype in Rural Drinking Water, Effluent, and the Aqueous Environment

ABSTRACT Total enterococci and vancomycin-resistant enterococci (VRE) were enumerated in samples of effluent (n = 50) and water (n = 167) from a number of sources. VRE were detected in the outflow of a wastewater treatment plant and in a single rural drinking water supply, suggesting potential for transmission to humans through environmental contamination.

First Report of Extended-Spectrum-β-Lactamase-Producing Salmonella enterica Serovar Kentucky Isolated from Poultry in Ireland

ABSTRACT Therapy of invasive human salmonellosis is complicated by increasing antimicrobial resistance. Food animals are the principal source of infection with nontyphoid Salmonella. We report the emergence of broad-spectrum-cephalosporin resistance in Salmonella enterica serovar Kentucky in poultry in Ireland.

First Report of Extended Spectrum β-Lactamase producing Salmonella Kentucky isolated from Poultry in Ireland

ABSTRACT Therapy of invasive human salmonellosis is complicated by increasing antimicrobial resistance. Food animals are the principal source of infection with nontyphoid Salmonella. We report the emergence of broad-spectrum-cephalosporin resistance in Salmonella enterica serovar Kentucky in poultry in Ireland.

Dissemination of extended-spectrum β-lactamase-producing Escherichia coli at home: a potential occupational hazard for healthcare workers?

Extended-spectrum b-lactamases (ESBLs) in Gram-negative pathogens are increasingly prevalent in Ireland. They present significant therapeutic and infection control challenges. While much of the literature has focused on the dissemination of ESBLproducing organisms to patients in different clinical and epidemiological settings, several reports have also investigated the transmission of such strains among household members of patients carrying them. However, the potential risk of