Metallo-Beta-Lactamase-Producing Acinetobacter spp. From Clinical Isolates at a Tertiary Care Hospital in Ghana

Metallo-beta-lactamase-producing Acinetobacter spp. is a major challenge for therapeutic treatment of nosocomial infections. This study is aimed at determining the prevalence of MBL-producing Acinetobacter spp. among 87 clinical isolates of Acinetobacter spp. from the Korle-Bu Teaching Hospital, Accra, between August 2014 and July 2015. Acinetobacter spp. was identified by standard bacteriological method, and resistance to different antibiotics was assessed with the Kirby-Bauer disc diffusion method. Meropenem-resistant Acinetobacter isolates were screened for enzyme activity using the modified Hodge test (MHT) and combined disc test (CDT). Additionally, multiplex PCR was used to determine MBL genes presence (blaVIM,blaIMP, and blaNDM). All Acinetobacter isolates showed high resistance to cefotaxime (90.8%), ceftazidime (75.9%), cotrimoxazole (70.1%), ciprofloxacin (64.4%), gentamicin (72.4%), levofloxacin (67.8%), and meropenem (59.8%). A total of 54 (62.1%) of Acinetobacter isolates were multidrug-resistant. Out of 52 (59.8%) meropenem-resistant Acinetobacter, 3 (5.8%) were carbapenemase producers by MHT, whilst, 23 (44.2%) were CDT positive. There was no significant difference between the resistance pattern of amikacin, ceftazidime, cotrimoxazole, ciprofloxacin, and meropenem amongst CDT-positive and CDT-negative isolates (p>0.05). A total of 7/87 (8.1%) CDT-positive Acinetobacter isolates harboured blaNDM; of these, 4 (57.1%) were from wound swabs, urine (n=2) (28.6%), and ear swab (n=1) (14.3%). The study revealed that less than 9% of Acinetobacter spp. contained blaNDM encoding genes. Strict antibiotics usage plan and infection control measures are required to prevent the spread of these resistance genes.