Multiple Drug Resistance in Escherichia coli Strains with Potential to Produce Shiga Toxins Isolated from Various Chicken Meats Obtained from Selected Vendors in Sri Serdang, Malaysia

Abstract

This study aimed to determine the presence, Shiga toxin production, contamination level and multidrug resistance properties of Escherichia coli isolated from chicken meat samples. Overall, 120 chicken parts — 20 samples from each of chicken breast, drumstick, wings, thighs, backs, and legs — were purchased from supermarkets and night market vendors and analyzed immediately after transfer to the laboratory. A bacteriological culture-based technique on MacConkey agar and Eosin Methylene Blue (EMB) agar, Gram staining, and further growth on Sorbitol MacConkey (SMAC) agar, and polymerase chain reaction (PCR) using the Stx2 primer were used to characterize the Shiga toxin-producing E. coli (STEC). Antimicrobial susceptibility testing using agar-disc diffusion was performed with commonly used antibiotics on Mueller-Hinton agar. Out of 120 samples, the prevalence of E. coli was 25% (n=30). Incidence was highest in chicken legs at 50% (n=10/20) and lowest in drumsticks at 10% (n=2/20). The highest contamination level was in chicken legs at 3.00 × 10³ CFU/g, while the lowest was observed in drumsticks at 1.32 × 10³ CFU/g. Of the 30 E. coli isolates, only 16.6% (n=5) harboured Stx2 genes, indicating the presence of STEC. High resistance was observed to Amoxycillin (100%), Tetracycline (100%), Doxycycline (93.3%), Mecillinam (90%), and Levofloxacin (70%). Low resistance was found to Ciprofloxacin (10%), Streptomycin (10%), Ceftazidime (13.3%), and Ceftriaxone (16.7%). Educating vendors on good hygiene practices is critical to eliminating contamination and preventing outbreaks associated with E. coli.