Emergence of VIM metallo-β-lactamase among carbapenem-resistant Pseudomonas species in northwest Nigeria

Background: Pseudomonas species are a leading cause of nosocomial infections particularly among the critically ill patients. The increased resistance to broad spectrum antibiotics observed in these strains makes the use of reserve antibiotics such as carbapenems a routine. However, resistance to carbapenems has also been reported worldwide. Here, we reported the first detection of VIM-carbapenemase producing Pseudomonas species in northwest Nigeria. Materials/methods: Consecutive, non-duplicate isolates of Pseudomonas species recovered from clinical samples in two leading hospitals in Sokoto, northwest Nigeria were collected and identified by matrix assisted laser desorption ionization time of flight mass spectrometry. The susceptibility of the isolates to antibiotics was determined using the disc diffusion method. Carbapenem resistant isolates were evaluated for carbapenemase production using the modified Carba-NP test. Carbapenemase encoding genes were investigated using RT-PCR technique and confirmed by conventional PCR and sequencing. Results: A total of 44 strains of Pseudomonas spp. were isolated from different pathological specimens processed in the two hospitals. The antibiotic susceptibility testing result showed that only 8 (18.2%) of the 44 Pseudomonas spp. were resistant to carbapenems. Five of the carbapenems resistant isolates were found to be carbapenemase producers by the modified Carba-NP test. Carbapenemase genes including bla(VIM-5) (n = 4) and bla(VIM-2) (n = 1) were identified in the five carbapenemase producing Pseudomonas species. Conclusions: We reported for the first time, the emergence of clinical Pseudomonas spp. harbouring blaVIM genes in northwest Nigeria. The finding of this study underscores the need for national antibiotic stewardship protocols in order to prevent outbreaks of multi-drug resistant bacterial infections in our hospitals.