Emergence of OXA-48 carbapenemase-producing Escherichia coli and Klebsiella pneumoniae in dogs

To evaluate the possible occurrence of carbapenemase-producing Escherichia coli and Klebsiella spp. strains in domestic animals. Veterinary clinical E. coli (n = 1175) and Klebsiella spp. (n = 136) isolates consecutively collected from livestock and companion animals in Germany from June 2012 to October 2012 were screened for their susceptibility to carbapenems using the agar disc diffusion test. Carbapenemase genes were characterized by PCR and sequencing; conjugation assays were performed. Carbapenemase-positive isolates were assigned to phylogenetic lineages by multilocus sequence typing and the clonal relatedness was determined using macrorestriction analysis and subsequent PFGE. Carbapenem non-susceptible isolates of Klebsiella pneumoniae (n = 5) and E. coli (n = 3) were obtained from six dogs hospitalized in a single veterinary clinic in Hessia, Germany, partly at the same time and consecutively over the study period. All isolates harboured carbapenemase gene blaOXA-48 located within Tn1999.2 transposons on conjugative ~60 kb plasmids. The K. pneumoniae isolates belonged to sequence type ST15, pulsotype 1, and coexpressed CTX-M-15, SHV-28, OXA-1 and TEM-1. Two E. coli isolates were assigned to ST1196 and pulsotype 2 and coproduced CMY-2, SHV-12 and TEM-1, while the third E. coli isolate was of ST1431 (pulsotype 3), and possessed blaCTX-M-1, blaOXA-2 and blaTEM-1. This is the first known report of OXA-48-producing bacteria from companion animals. The clonal nature of the K. pneumoniae and two E. coli isolates suggests a nosocomial dissemination rather than repeated introduction by individual patients into the clinic.