Wide spread of carbapenemase producers in a Nigerian environment.

Abstract

BACKGROUND\nOccurrence of carbapenemase producers is not only found in hospital and community settings, but also in the environment. It may correspond to acquired and usually plasmid-borne ß-lactamase genes, or to chromosomal genes being intrinsic to the species.\n\n\nOBJECTIVES\nWe aimed to evaluate the occurrence of such carbapenemase prodcuers among environmental samples from Nigeria.\n\n\nMETHODS\nAfter plating 122 environmental samples on carbapenem-containing media, 259 isolates were recovered from which 125 were carbapenemase producers according to the results of the Rapid CARBA NP test.\n\n\nRESULTS\nThe majority of the strains recovered corresponded to natural producers of carbapenemases, i.e.Stenotrophomonas maltophilia (n\u2009=\u2009108), Burkholderia cepacia (n\u2009=\u20091), Shewanella spp. (n\u2009=\u20091), Sphingobacterium spp. (n\u2009=\u20091) and Chryseobacterium gleum (n\u2009=\u20091). Eleven strains (Enterobacteriaceae, Acinetobacter baumannii) produced an acquired carbapenemase, being mostly of the NDM-type. In addition, two Pseudomonas otitidis strains were identified as producing the Ambler class B carbapenemase POM-1, further confirming that this carbapenemase is naturally produced in that environmental species. Finally, several isolates co-producing 16S rRNA methylases (ArmA, RmtC) and/or extended-spectrum ß-lactamases (CTX-M-9, CTX-M-15) were also identified.\n\n\nCONCLUSION\nOur study revealed the presence and the diversity of clinical relevant antibiotic resistance bacteria into the environment in Nigeria.