Plasmid-mediated 16S rRNA methylases among extended-spectrum- -lactamase-producing Salmonella enterica Senftenberg isolates from Algeria

blaCTX-M-15, 9 isolates representative of individual PFPs (comprising 78 isolates) had peak profiles corresponding to blaCTX-M-14, 2 isolates representative of individual PFPs (comprising 3 isolates) had peak profiles corresponding to blaCTX-M-9 and 1 isolate had a peak profile corresponding to blaCTX-M-1. The rapid dissemination of CTX-M-producing Enterobacteriaceae reported in a number of countries is a significant public health concern. In this study, members of CTX-Mgroup-1and CTX-M-group-9-producing isolates were both common, accounting for 60% and 40% of isolates, respectively. This is in keeping with what has previously been observed in other European countries. CTX-M-14 accounts for most CTX-M-group-9 enzymes in Ireland. This is similar to the situation reported from Spain, where CTX-M-14 is the predominant group-9 CTX-M enzyme, but contrasts with the neighbouring UK where CTX-M-14 appears to be less common. CTX-M-15 is the predominant group 1 genotype, again in concordance with what has been observed in other European countries. The dissemination of specific clones or clonal groups has been central to the dramatic increase in the prevalence of CTX-M b-lactamases in Europe and worldwide. In this study, six major clusters of related isolates comprising 50% of all CTX-M-producing E. coli were defined by PFGE. Few healthcare institutions in Ireland have reported outbreaks of ESBL-PE transmission. These data show evidence of interand intrahospital dissemination of clonal groups. We also identified the presence of the UK epidemic ‘strain A’, which has recently been confirmed as belonging to the internationally disseminated clone O25:H4-ST131. The widespread dissemination of Enterobacteriaceae producing CTX-M-15 and CTX-M-14 in Ireland may reflect introduction via foreign travel, originally from areas where these genotypes are common, and subsequent significant local spread. Spread may be facilitated by levels of antimicrobial consumption. According to a recent European Surveillance of Antimicrobial Consumption report, the total outpatient use of antimicrobials in Ireland was 21.23 defined daily doses per 1000 inhabitants in 2006, representing midto high-range use compared with other European countries. Although there is recent evidence of increasing public policy emphasis on and public interest in the control of antimicrobial resistance, there is little evidence that measures taken to date have lead to improved control of the dissemination of ESBL-PE in the community and the principal routes of transmission in this setting have not been defined.