Table 2_Antimicrobial resistance patterns of Escherichia coli detected from milk, milking environment, and milk consumers in Addis Ababa milksheds, Ethiopia.xlsx

Isolates were tested for antimicrobial susceptibility against twelve antimicrobials from eight antimicrobial classes using the Kirby-Bauer disk diffusion method on Mueller-Hinton agar, following the guidelines of the European Committee on Antimicrobial Susceptibility Testing (EUCAST). Multidrug resistance (MDR) and multiple antimicrobial resistance indices (MARI) were calculated, and analyses were performed using R. Presumptive E. coli was isolated from 18.6% and confirmed in 12.6% of the 404 samples analyzed.

Overall, 84.3% of isolates were resistant to at least one antimicrobial tested, with the highest resistance rates for gentamicin (64.7%), ampicillin (52.9%), and tetracycline (41.2%), while resistance to ceftazidime (5.9%) and cefotaxime (7.8%) were low. MDR was observed in 50.9% of the isolates, with MARI values ranging from 0.17 to 1. The study revealed a low detection rate of E. coli but a considerably high proportion of AMR in Addis Ababa milksheds, Ethiopia.

The finding underscores the need for targeted One Health surveillance to curb the emergence and simultaneous occurrences of antimicrobial-resistant E. coli at dairy production interfaces and safeguard public health.</p>