characterization of Escherichia Coli isolated from chicken derived fecal samples in Uganda

Abstract

Antimicrobial resistance (AMR) is a global health distress, that threatens attainment of Sustainable Development Goals. A high cost is incurred in the treatment of resistant bacterial infection in animals and humans. The study aimed at obtaining the antibiograms of the archived E. coli isolates from chicken farms in Wakiso District. Furthermore, the bacteria were screened for the presence of the tetM gene. The study was carried out in CDL laboratory at COVAB, Makerere university between the month of December 2019 and February 2020. A total of 81 archived E. coli were selected, retrieved from -80 ⁰C freezer. These were first enriched in the nutrient broth then sub cultured on MacConkey to observe the colonies formed. Biochemical tests were performed to confirm the isolates then drug sensitivity was done using 9 antibiotics, Tetracycline, Colistin, Meropenem, Cefepime, Chloramphenicol, Cephalexin, Ampicillin, Gentamicin and Co-trimoxazole. A conventional PCR was carried out to screen for the presence of tetM and MecA genes. The E. coli isolates were highly resistant to Tetracycline 79/81(97.53%) and Co-trimoxazole 78/81(96.30%), moderate resistance was obtained against Ampicillin 38/81(46.91), Cephalexin 34/81(41.98%) and Colistin 57/81/49(70.37%). A low resistance was obtained in Chloramphenicol 9/81(11.11%), Gentamicin 6/81(7.41%), Meropenem 2/81(2.47%) and Cefepime 0/81(100%). All E. coli isolates screened negative for the tetM gene. The study confirmed existence of AMR in E. coli archived poultry isolates were most of the resistance was multiple at 98.7% with only 1.2% resistance to 1 antibiotic. There was a high resistance to the most commonly used antibiotics such as Co-trimoxazole and tetracycline and a low resistance frequency among the newly introduced antibiotics like Meropenem and Cefepime. Prudent use of antibiotics should be highly embraced by veterinary practitioners and farmers. More studies on genotypic characterization of E. coli isolates from poultry farms should be carried out to assess the prevalence of the resistant genes. This will help in drawing attention to the most relevant control points.