Isolation and identification of antimicrobial-resistant strains of Escherichia coli from poultry meat

Abstract

The rising prevalence of antibiotic-resistant Escherichia coli (E. coli) serotypes in poultry meat represents a significant public health concern, complicating the treatment of infections in both humans and animals. This study aimed to isolate and identify various E. coli serotypes from poultry meat samples and evaluate their antibiotic resistance profiles. A total of 100 refrigerated poultry meat samples were collected from the Central Agricultural Market in Chisinau and analyzed using microbiological methods, including selective culturing on E. coli-specific media and typing using Bruker MALDI-TOF biotyper. Antibiotic susceptibility was assessed through disk diffusion method. The findings revealed a range of resistance levels to commonly used antibiotics in poultry farming. Most isolates exhibited typical E. coli characteristics, such as lactose fermentation on MacConkey agar and metallic green sheen on Eosin Methylene Blue agar. Notably, some serotypes demonstrated the ability to grow efficiently at temperatures exceeding 42°C. Resistance to at least one antibiotic was observed in over 40% of the serotypes, while 17% showed multidrug resistance (resistant to three or more antibiotics). The highest resistance rates were found for chloramphenicol, aztreonam, and enrofloxacin. These results highlight the need to revise treatment protocols in poultry production and emphasize cautious use of antibiotics-whether for treatment or prophylaxis-to curb the spread of resistant E. coli strains.