Phenotypic Detection of Extended Spectrum Beta lactamase and Carbapenemase Co-producing Clinical Isolates from Two Tertiary Hospitals in Kano, North West Nigeria.

BACKGROUND: Continue rise in unprofessional use of antibiotics in our hospitals and communities is worrisome. A research study was therefore conducted to detect extended spectrum beta-lactamase (ESBL), carbapenemase, metallobeta lactamase and their co-production phenotypically from isolates obtained from patients admitted to or attending two tertiary hospitals in Kano, Nigeria.

METHOD: A total of 248 isolates of Escherichia coli and Klebsiella pneumoniaewere screened phenotypically for ESBL production and carbapenemase production according to CLS1 2012 breakpoints using double disk synergy test and modified Hodge test (MHT) respectively. Antibiotic susceptibility of the organisms was tested against colistin, tigecycline and 3 flouroquinolones.

RESULTS: The result shows that 58.0% of the isolates were ESBL producers with higher percentage in K. pneumoniae (62.9%). Further, about 40.3% and 36.6% of the isolates were resistant to meropenem and imipenem respectively. However, E. coli showed higher resistance to meropenem (47.1%) while K. pneumoniae showed higher resistance to imipenem (44.4%). Co-productions of carbapenemase and ESBL were observed in both E. coli and K. pneumoniae. Carbapenemase producing isolates were more obtained from uro-pathogens and wound isolates, with almost all the cases of co-production of the β lactamases occurring in urine and cathertips isolates. Overall susceptibilities of the isolates to colistin and tigecycline were 64.6and70.0% respectively, but isolates were less susceptible to flouroquinolones.

CONCLUSION: The finding of the study therefore indicates that carbapenem resistance is mediated by carbapenemase production and or overproduction of ESBL coupled with reduced porins. Co-production of carbapenemase, MBLs and ESBLs by some of the isolates is worrisome. Susceptibility to colistin and tigecycline was still promising, but increasing resistance to flouroquinolones has been observed.