Colonisation with extended-spectrum beta-lactamase (ESBL) not detected in a prevalence study.

Background The Mid-West of Ireland has higher than average national rates of invasive extended-spectrum beta-lactamase (ESBL) bloodstream infections and carbapenemase-producing Enterobacteriaceae (CPE), with increasing numbers of ESBL isolates detected in community-dwelling patients. Aims To conduct a point prevalence study in a convenience sample of the Mid-West population with the aim of determining the extent of ESBL colonisation Methods Utilising anonymised community stool samples that had completed routine analysis, we conducted a point prevalence study over a four-week period on all samples that met defined inclusion and exclusion criteria. Limited epidemiological data was recorded: (1) age of patient, (2) gender, (3) sender location. From these stool specimens, rectal swabs were inoculated (eSwab™ 480CE, Copan, Italy), which were subsequently cultured on selective chromogenic agar (Colorex™ ESBL). Culture plates were incubated aerobically at 37˚C for 24 hours. Results Of 195 samples processed, 58% (n=112) were from females. The median patient age was 62.4 years (range 20-94 years). 186 samples (95%) originated from general practitioner clinics. During the study period, only nine eligible stool samples were received from LTCF (6 public). From 195 Colorex™ ESBL chromogenic agar plates cultured, no ESBL-producing organisms were detected. Conclusions This community point prevalence study did not identify ESBL-colonisation despite high numbers of patients with invasive ESBL bloodstream infections presenting for admission in our institution. We believe this may be because of our small sample size. Data regarding antimicrobial exposure and other risk factors for ESBL-colonisation was also not available. We remain vigilant for ESBL-producing organisms

An optimised work-flow to reduce time-to-detection of carbapenemase-producing Enterobacteriaceae (CPE) using direct testing from rectal swabs

Rapid detection of patients with carbapenem-producing Enterobacteriaceae (CPE) is essential for the prevention of nosocomial cross-transmission, allocation of isolation facilities and to protect patient safety. Here, we aimed to design a new laboratory work-flow, utilising existing laboratory resources, in order to reduce time-to-diagnosis of CPE. A review of the current CPE testing processes and of the literature was performed to identify a real-time commercial polymerase chain reaction (PCR) assay that could facilitate batch testing of CPE clinical specimens, with adequate CPE gene coverage. Stool specimens (210) were collected; CPE-positive inpatients (n=10) and anonymised community stool specimens (n=200). Rectal swabs (eSwab™) were inoculated from collected stool specimens and a manual DNA extraction method (QIAamp® DNA Stool Mini Kit) was employed. Extracted DNA was then processed on the Check-Direct CPE® assay. The three step process of making the eSwab™, extracting DNA manually and running the Check-Direct CPE® assay, took <5 minutes, 1 hour 30 minutes and 1 hour 50 minutes, respectively. It was time efficient with a result available in under 4 hours, comparing favourably with the existing method of CPE screening; average time-to-diagnosis of 48/72 hours. Utilising this CPE work-flow would allow a ‘same-day’ result. Antimicrobial susceptibility testing results, as is current practice, would remain a ‘next-day’ result. In conclusion, the Check-Direct CPE® assay was easily integrated into a local laboratory work-flow and could facilitate a large volume of CPE screening specimens in a single batch, making it cost-effective and convenient for daily CPE testing

A case of fatal daptomycin-resistant, vancomycinresistantenterococcal infective endocarditis in end-stage kidney disease

Introduction: Ireland currently has the highest reported rate in Europe of vancomycin-resistant Enterococcus (VRE) isolated from the bloodstream, but data regarding the prevalence of VRE endocarditis remain scarce. Treatment options for Enterococcus-mediated endocarditis are limited, and therefore daptomycin is commonly used off licence in this setting. Case presentation: A 60-year-old male with end-stage kidney disease (ESKD) presented with VRE bacteraemia secondary to a gangrenous right foot colonized with vancomycin-resistant Enterococcus faecium. Aortic valve endocarditis was confirmed using transoesophageal echocardiography. Treatment was commenced with linezolid and subsequently modified to combination therapy with daptomycin and rifampicin. High-dose daptomycin therapy was employed unsuccessfully and, after 20 days of therapy, daptomycin resistance emerged, which proved fatal. Conclusion: The case was ethically challenging and involved a refusal of amputation and, ultimately, any form of treatment by the patient. In summary, however, daptomycin-resistant VRE bacteraemia complicated by recalcitrant daptomycin-resistant VRE endocarditis proved fatal for this patient. Further evaluation of the efficacy and safety of high-dose daptomycin for the treatment of VRE infective endocarditis is needed

The first occurence of a CTX-M ESBL-producing Escherichia coli outbreak mediated by mother to neonate transmission in an Irish neonatal intensive care unit.

Background: Escherichia coli (E. coli) comprise part of the normal vaginal microflora. Transfer from mother to neonate can occur during delivery resulting, sometimes, in neonatal bacterial disease. Here, we aim to report the first outbreak of CTX-M ESBL-producing E. coli with evidence of mother-to-neonate transmission in an Irish neonatal intensive care unit (NICU) followed by patient-to-patient transmission. Methods: Investigation including molecular typing was conducted. Infection was defined by clinical and laboratory criteria and requirement for antimicrobial therapy with or without positive blood cultures. Colonisation was determined by isolation without relevant symptoms or indicators of infection. Results: Index case was an 8-day-old baby born at 34 weeks gestation who developed ESBL-producing E. coli infections at multiple body sites. Screening confirmed their mother as colonised with ESBL-producing E. coli. Five other neonates, in the NICU simultaneously with the index case, also tested positive. Of these, four were colonised while one neonate developed sepsis, requiring antimicrobial therapy. The second infected neonate’s mother was also colonised by ESBL-producing E. coli. Isolates from all eight positive patients (6 neonates, 2 mothers) were compared using pulsed-field gel electrophoresis (PFGE). Two distinct ESBL-producing strains were implicated, with evidence of transmission between mothers and neonates for both strains. All isolates were confirmed as CTX-M ESBL-producers. There were no deaths associated with the outbreak. Conclusions: Resources were directed towards control interventions focused on hand hygiene and antimicrobial stewardship, which ultimately proved successful. Since this incident, all neonates admitted to the NICU have been screened for ESBL-producers and expectant mothers are screened at their first antenatal appointment. To date, there have been no further outbreaks

Incidence, management and outcomes of the first cfr-mediated linezolid-resistant Staphylococcus epidermidis outbreak in a tertiary referral centre in the Republic of Ireland.

Aim: To report the first Irish outbreak of cfr-mediated linezolid-resistant Staphylococcus epidermidis. Methods: Linezolid-resistant S. epidermidis isolated at University Hospital Limerick from four blood cultures, one wound and four screening swabs (from nine patients) between April and June 2013 were characterized by pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and staphylococcal cassette chromosome (SCCmec) typing. Antibiotic susceptibilities were determined according to the guidelines of the British Society for Antimicrobial Chemotherapy. The outbreak was controlled through prohibiting prescription and use of linezolid, adherence to infection prevention and control practices, enhanced environmental cleaning, isolation of affected patients, and hospital-wide education programmes. Findings: PFGE showed that all nine isolates represented a single clonal strain. MLST showed that they belonged to ST2, and SCCmec typing showed that they encoded a variant of SCCmecIII. All nine isolates were cfr positive, and eight isolates were positive for the G2576T 23S rRNA mutation commonly associated with linezolid resistance. Isolates exhibited multiple antibiotic resistances (i.e. linezolid, gentamicin, methicillin, clindamycin, ciprofloxacin, fusidic acid and rifampicin). The adopted infection prevention intervention was effective, and the outbreak was limited to the affected intensive care unit

An Irish outbreak of New Delhi metallo-β-lactamase (NDM)-1 carbapenemase-producing Enterobacteriaceae: increasing but unrecognised prevalence

Background Carbapenemase-producing Enterobacteriaceae (CPE) can cause healthcare–associated infections with high mortality rates. New Delhi metallo-beta-lactamase-1 (NDM-1) is amongst the most recently discovered carbapenemases. Aim To report the first outbreak of NDM-1 CPE in Ireland, including microbiological and epidemiological characteristics, and assessing the impact of infection prevention and control measures. Methods Retrospective microbiological and epidemiological review. Cases were defined as patients with a CPE positive culture. Contacts were designated as roommates or ward mates. Findings This outbreak involved ten patients, with a median age of 71 years (range 45-90 years), located in three separate but affiliated healthcare facilities. One patient was infected (the index case); the nine others were colonised. Nine NDM-1-producing Klebsiella pneumoniae, a NDM-1-producing Escherichia coli and a K. pneumoniae carbapenemase (KPC)-producing Enterobacter cloacae were detected between week 24 2014 and week 37 2014. Pulsed field gel electrophoresis demonstrated similarity. NDM-1 positive isolates were meropenem resistant with MICs ranging from 12 to 32 μg/ml. All were tigecycline susceptible (MICs ≤1 μg/ml). One isolate was colistin resistant (MIC 4.0 μg/ml; mcr-1 gene not detected). In 2015, four further NDM-1 isolates were detected. Conclusions The successful management of this outbreak was achieved via the prompt implementation of enhanced infection prevention and control practices to prevent transmission. These patients did not have a history of travel outside of Ireland, but a number had frequent hospitalisations in Ireland, raising concerns regarding the possibility of increasing but unrecognised prevalence of NDM-1 and potential decline in value of travel history a marker of colonisation risk