Molecular characterization of multidrug-resistant Escherichia coli in the Greater Accra Region, Ghana: a 'One Health' approach.

Background: "One Health," a concept that highlights the need to bring on board multiple players and actors together to address major health problems, has been proposed to be effective in data gathering to mitigate the menace of antimicrobial drug resistance (AMR). Genomic data on extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-EC) across humans, animals, and the environment are limited in low- and middle-income countries (LMICs), including Ghana.

Objective: This study determined the prevalence and patterns of AMR in E. coli from diverse sources, and characterized AMR genes, sequence types (STs), and plasmid replicon types in ESBL-EC.

Methodology: In a cross-sectional study, we randomly collected 1500 specimens from healthy humans, cattle, pigs, lettuce, spring onions, pork, beef, and soil samples, between January 2022 - April 2023. E. coli was isolated by routine culture and confirmed by MALDI-TOF MS. E. coli isolates were screened for their susceptibility against 13 antimicrobial agents and ESBL-production. ESBL-EC isolates were whole-genome sequenced (WGS), and in silico analysis was used to determine AMR genes, sequence types (STs), and plasmid replicon types.

Result: Of the 1500 specimens from diverse sources cultured, 140 (9.3%) were positive for E. coli. No E. coli was isolated from lettuce, spring onions, and pork. Fifty (35.7%) E. coli isolates were resistant to three or more of the antimicrobials tested, and 30 (21.4%) were ESBL-EC. The proportion of ESBL-EC identified in healthy humans were 14 (20%), cattle 9 (22.5%), pigs 3 (15%), beef 1 (50%) and soil 3 (37.5%). ESBL-EC isolates were highly resistant to ampicillin (100%), cefuroxime (100%), ciprofloxacin (53.6%), and tetracycline (58.2%). However, all ESBL-EC were susceptible to meropenem. Commonly detected AMR genes were blaTEM-1B (32%), tetA (48%) and sul2 (32%), with majority recovered from healthy human and soil samples. The dominant sequence types found were 12% (3) for ST10, ST 9312, ST 206, and ST 4151. The prevalent plasmid replicon types detected were IncFIB (Apoo1918) (40%) and IncFII (pCoo) (36%).

Conclusion: Within the metropolis surveyed, we identified MDR ESBL-EC harbouring various AMR genes and plasmid replicon types with diverse E. coli sequence types in healthy humans, animals, and the environment. The detection of blaCTX-M-15 in agricultural soil isolate is worrisome, emphasizing the need for a "One Health" approach in combating AMR.