Investigation of the first outbreak of OXA-48-producing Klebsiella pneumoniae in Ireland

SummaryBackgroundCarbapenemase-producing Enterobacteriaceae (CPE) strains are encountered with increasing frequency in Europe. In November 2010 the European Centre for Disease Control (ECDC) graded Ireland as only having sporadic occurrence of CPE.AimTo describe the epidemiological and molecular typing analysis of the first outbreak of OXA-48-producing Klebsiella pneumoniae in an Irish tertiary care referral centre.MethodsSixteen OXA-48-producing K. pneumoniae isolates were detected, from both clinical and screening specimens, and analysed by pulsed-field gel electrophoresis and by multi-locus sequence typing.FindingsTyping analysis revealed that two outbreak strains were circulating in the hospital, one among surgical patients and one among medical patients. The ‘medical strain’ ST13 had already been identified as an internationally disseminated clone, whereas the ‘surgical strain’ ST221 had not previously been reported as an OXA-48-carrying strain.ConclusionAlthough the outbreak on surgical wards was successfully controlled by implementing strict infection control measures, intermittent detection of individual patients carrying the ‘medical strain’ of OXA-48 K. pneumoniae has persisted since then. The experience from this outbreak suggests that OXA-48 K. pneumoniae is endemic at low level in the healthcare setting in the Dublin region.