Antimicrobial Susceptibility and Molecular Characterization of Escherichia coli Recovered from Milk and Related...

Area of Science:

• Food safety and microbiology
• Veterinary public health
• Antimicrobial resistance

Background:

• Pathogenic microorganisms like Escherichia coli (E. coli) in milk pose a significant health risk.
• Understanding the prevalence and characteristics of E. coli in the dairy supply chain is crucial for public health.

Purpose of the Study:

• To investigate the occurrence and antimicrobial susceptibility of E. coli in cow milk and associated farm samples.
• To determine the genetic relatedness of E. coli isolates to identify potential sources of contamination.

Main Methods:

• Culturing of 250 samples (raw milk, teat, hands, utensils, feces) for E. coli identification.
• Antimicrobial susceptibility testing of isolated E. coli strains.
• Partial sequencing and phylogenetic analysis to assess genetic relatedness.

Main Results:

• E. coli was detected in 40.4% of samples, with the highest prevalence in milk (68.0%) and fecal matter (66.0%).
• Significant antimicrobial resistance was observed, particularly to teicoplanin (100%), while susceptibility was high for chloramphenicol (95.2%) and azithromycin (92.9%).
• Phylogenetic analysis revealed 11 haplotypes and relatedness among isolates, suggesting cross-contamination across samples and potential links to other African regions.

Conclusions:

• E. coli is prevalent in cow milk and related farm environments, posing a food safety risk.
• Multiple drug resistance in E. coli isolates is a concern, necessitating careful antibiotic use in dairy farming.
• Genetic relatedness indicates cross-contamination pathways, highlighting the need for improved hygiene practices throughout milk production.