Phenotypic and Genotypic Detection of Carbapenemase-Producing Escherichia Coli and Klebsiella Pneumoniae in Accra, Ghana

Background: Escherichia coli and Klesbsiella pneumoniae belong to the Enterbacteriaceae family, and are pathogens of high clinical significance. They are prone to acquiring antibiotic resistance genes, including those encoding carbapenemases, which confer resistance to carbapenems (the current drugs of the last resort against infections with multidrug-resistance [MDR] Enterobacteriacaea). However , little is known about carbapenemase-producing E.coli and K.pneumoniae in Ghana. Aim: To investigate the occurence of the carbapenem resistance among MDR E. coli and K.pneumoniae isolated from clinical specimens in Accra using phenoypic and genotypic methods. Methodology: The study was cross-sectional, involving 114 clinics MDR E.coli and K. pneumoniae isolates originating from 15 different samples types from the Central Microbiology Laboratory of the Korel bu Teaching Hospital between the periods of December 2020 to March 2021. The isolates were re-cultured, subsequently identified using standard biochemical tests, and subjected to antibiotic sussceptibility testing using the Kirby-Bauer methods. Carbapenem resistance was determinedbased on imipenem, meropenem, and ertapenem zones of inhibition, as well as mininium inhibitory concentrations (MIC_S); carbapenemase was confirmed phenotypically with the Modified Hodge test (MHT) and Modified Carbapenem Inactivation Method (mCIM) and genotypically with miltiplex PCR targeting blac_KPC,bla_IMP, bla_NDM, blA_VIM, and bla_OXA-48. Results: Of the 144 MDR isolates, (69.4%) were E-coli and K.pnemoniae. The distribution of antimicrobial resistance rates among them were ampicillin (97.2%), cefuroxime (93.1%). sulfamethoxazole-trimethoprim (86.8%), tetracycline (85.4%), cefotaxime and cefpodxime (77.1%) each , amoxicillin-clavulanate (75%),ceftriaxone (73.6%), ciprofloxacin (70.8%),levofloxacin (66.0%), cefepime (65.3%). ceftazidime (64.6%), gentamicin (48.6%) ,piperacillin-tazobactam (40.3%) , cefoxitin (14.6%), amikacin (13.9%), ertapenem and meropenem (5.6%) each , and imipenem (2.8%). In total, 5.6% (8/144) of them were carbapenem-resistant (carbapenem MIC range =0.094-32.0 ug/ml), with 75% (6/8) of these testing positive by the phenotypic tests and 62.5% (5/8) by the genotypic test of which 80% [4/5] carried bla_OXA-48 and 20% (1/5)bla_NDM). The bla_IMP,bla_VIM, and bla_KPC genes were not detected. Conclusin: Although the rates of antubiotic resistance among the isloates were high, the prevallence of carbapenemase producers were low. There is evidence that bla_OXA-48 and bla_NDM may be circulating in Ghana, warranting upscaling of antimicrobial resistance surveillance programmes and fortification of infection prevention and control programmes in the country. (author)