Abstract
Resistance to cephalosporins of the third and fourth generations in Enterobacteriaceae is an increasing problem worldwide. This resistance is mainly attributed to the production of extended-spectrum β-lactamases (ESBLs). In Nigeria SHV-, TEM- and CTX-M-type ESBLs have been reported in Enterobacter spp., Klebsiella spp. and Escherichia coli.1–3 Besides these classical ESBLs, there are various other plasmid-mediated β-lactamases that are less common but which are regarded as emerging and increasing in frequency among the β-lactamase family. Here we report the emergence of OXA-10, VEB-1 and CMY β-lactamases and mobile genetic elements in three clinical isolates of Providencia spp. isolated between October 2008 and April 2009 in two tertiary hospitals in Nigeria.
Three strains of Providencia spp. were identified using the VITEK 2 GN card system following cultivation of clinical samples on MacConkey agar and blood agar base with 5% sheep blood (Oxoid, UK). Isolate Providencia rettgeri 58K was recovered in late 2008 from the catheter tip of a patient hospitalized at Lagos University Teaching Hospital (LUTH) in Lagos, Nigeria. The patient was notably hypertensive and was diagnosed with an exacerbation of chronic kidney disease, secondary to adult polycystic kidney disease. He had been catheterized for 19 days, with insertion of the catheter from the private hospital where he was hospitalized before his referral to LUTH. The patient was not febrile at any time and there was no infection documented. Isolate Providencia stuartii V1 was recovered from the gunshot wound of a patient admitted to the National Orthopaedic Hospital Igbobi (NOHI), Lagos, in early 2009, while isolate P. stuartii V2 was also recovered at NOHI from the wound swab of a patient who had had a motorcycle accident. The three patients had not received antibiotics prior to the isolation of the strains.