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

BACKGROUND: Carbapenemase-producing Enterobacteriaceae (CPE) may cause healthcare-associated infections with high mortality rates. New Delhi metallo-ß-lactamase-1 (NDM-1) is among 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: This was a 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 10 patients with a median age of 71 years (range: 45-90), located in three separate but affiliated healthcare facilities. One patient was infected (the index case); the nine others were colonized. Nine NDM-1-producing Klebsiella pneumoniae, an 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 minimum inhibitory concentrations (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. CONCLUSION: 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 several had frequent hospitalizations in Ireland, raising concerns regarding the possibility of increasing but unrecognized prevalence of NDM-1 and potential decline in value of travel history as a marker of colonization risk.

First report of IMI-1-producing colistin-resistant Enterobacter clinical isolate in Ireland, March 2013.

We report the first case in Ireland of an IMI-1 carbapenemase-producing Enterobacter asburiae, which was resistant to both colistin and fosfomycin. The circumstances under which this isolate was acquired were unclear. Several reports of IMI-producing Enterobacter spp. have emerged in recent years, and colistin resistance in Enterobacteriaceae is also increasingly reported. Laboratories should be aware of the unusual antibiograms of IMI-producing isolates.

Use of palivizumab and infection control measures to control an outbreak of respiratory syncytial virus in a neonatal intensive care unit confirmed by real-time polymerase chain reaction.

Respiratory syncytial virus (RSV) is a potentially life-threatening infection in premature infants. We report an outbreak involving four infants in the neonatal intensive care unit (NICU) of our hospital that occurred in February 2010. RSV A infection was confirmed by real-time polymerase chain reaction. Palivizumab was administered to all infants in the NICU. There were no additional symptomatic cases and repeat RSV surveillance confirmed that there was no further cross-transmission within the unit. The outbreak highlighted the infection control challenge of very high bed occupancy in the unit and the usefulness of molecular methods in facilitating detection and management.

Molecular characterization of carbapenem-resistant Acinetobacter species in an Irish university hospital: predominance of Acinetobacter genomic species 3.

A 30 month prospective study of Acinetobacter species encountered in the Central Pathology Laboratory of St James's Hospital, Dublin, Ireland, was conducted to investigate the prevalence and molecular epidemiology of carbapenem resistance in such isolates. Acinetobacter genomic species 3 (AG3) was found to be the predominant Acinetobacter species (45/114, 39 %) in our institution. A total of 11 % of all Acinetobacter species (12/114) and 22 % of AG3 isolates (10/45) were carbapenem resistant. Carbapenem resistance was mediated by Ambler class D beta-lactamase OXA-23 in all 12 isolates, with insertion sequence ISAba1 found upstream of bla(OXA-23). ISAba1 was also found upstream of bla(ADC-25), which encodes the enzyme AmpC, in an Acinetobacter baumannii isolate, and upstream of the aminoglycoside-acetyltransferase-encoding gene aacC2 in three AG3 isolates. Inter-species plasmidic transfer was most likely involved in the emergence and spread of bla(OXA-23) among the Acinetobacter isolates within our institution. The emergence of carbapenem resistance was associated not only with prior carbapenem use but also with the use of other antimicrobial agents, most notably beta-lactam/beta-lactamase-inhibitor combinations. The study demonstrated the emerging trend of carbapenem resistance in the wider context of the Acinetobacter genus, and reiterated the paramount importance of the prudent use of antimicrobial agents, stringent infection control measures and resistance surveillance of pathogens.

Detection and molecular characterisation of plasmidic AmpC beta-lactamases in Klebsiella pneumoniae isolates from a tertiary-care hospital in Dublin, Ireland.

This study determined the types of AmpC enzymes produced by Klebsiella pneumoniae isolates resistant to third-generation cephalosporins and the clonality of these isolates. The presence of AmpC enzymes was identified by cephalosporin-cloxacillin synergy tests. Genes encoding AmpC enzymes were characterised by PCR and sequencing. Pulsed-field gel electrophoresis (PFGE) was used to type the isolates. Fifteen K. pneumoniae isolates were positive for bla(AmpC), 13 were positive for bla(ACC-1) and two were positive for bla(DHA-1). Production of the DHA-1 enzyme was inducible. The ampR gene was identified upstream of the bla(DHA-1) gene. PFGE demonstrated the polyclonal origin of the isolates carrying bla(ACC-1).

Candidaemia in an Irish tertiary referral hospital: epidemiology and prognostic factors.

There were two parts to this study. Part 1 evaluated the epidemiology of Candida bloodstream isolates within the Southern Health Board (SHB) of Ireland from 1992 to 2003 by retrospective surveillance of all such isolates of patients reported from SHB hospitals to our laboratory database during that period. Part 2 reviewed candidaemia cases occurring in Cork University Hospital (CUH) from 1999 to 2003 using surveillance of all positive blood culture isolates in CUH microbiology laboratory during the 5-year period. In part 1, 250 Candida bloodstream isolates were reported in the SHB over 12 years. There was a pattern of decreasing percentage of C. albicans with time. Whereas in part 2, 63 cases of candidaemia were identified in CUH from 1999 to 2003. Candida albicans constituted 50% of all isolates, while C. parapsilosis and C. glabrata accounted for 21.2% and 18.2% respectively. Average annual incidence rate was 0.48 episodes/1000 admissions and 0.70 episodes/10 000 patient-days. Vascular catheters were the commonest source of candidaemia (61.9%) followed by the urinary tract (12.7%). Risk factors included exposure to multiple antibiotics (75%); central vascular catheterization (73%); multiple colonization sites (71%); severe gastrointestinal (GI) dysfunction (54%) and acute renal failure (43%). Crude 7-day and 30-day mortality rates were 20.6% and 39.7% respectively. Logistic regression multivariate analysis identified the following to be independent predictors for mortality: age > or =65 years [odds ratio (OR) 7.2, P = 0.013]; severe GI dysfunction (OR 10.6, P = 0.01); acute renal failure (OR 7.6, P = 0.022); recent/concurrent bacteraemia (OR 5.2, P = 0.042); endotracheal intubation (OR 7.7, P = 0.014); while major surgery was associated with a better prognosis (OR 0.05, P = 0.002). Appropriate antifungal treatment was also found to be associated with survival (Fisher's exact test, P < 0.001). The epidemiology of Candida bloodstream isolates within our health board had changed over the years. Incidence and mortality of candidaemia were relatively high in our hospital. Dysfunction of major organ systems and recent bacteraemia were found to predict mortality.

Prosthetic valve endocarditis caused by Veillonella parvula.

Veillonella species is a rare cause of endocarditis. We report a case of a 49-year-old man with Veillonella parvula prosthetic valve endocarditis who presented with acute cardiac failure due to valvular dehiscence. His clinical course was complicated by cortical blindness and limb paresis as a result of cerebral embolism. The endocarditis was successfully treated with urgent valve replacement surgery and a prolonged course of metronidazole.

Erysipelothrix rhusiopathiae endocarditis: a preventable zoonosis?

BACKGROUND: Erysipelothrix rhusiopathiae is a bacterium ubiquitous in the environment. It can cause a variety of diseases and the risk of infection is closely related to the level of occupational exposure to infected or colonised animals. AIMS: To discuss the clinical features and treatment of this zoonosis, to increase awareness of this pathogen and to emphasise the need for meticulous attention to hygienic work practices in reducing the risk of infection. METHOD: A case report of a farmer with E. rhusiopathiae endocarditis and the management of the infection. RESULTS: The patient was successfully treated with valve replacement surgery and antimicrobial therapy. CONCLUSIONS: Early identification of this microorganism is essential for appropriate treatment of endocarditis. Greater awareness and safe work practices can help reduce the risk of human infection by this microorganism.