Resistance Profile of Strains of Escherichia coli and Salmonella sp. Isolated from Raw Cow Milk Sold in the Department of Vina in Cameroon

Aims: Antimicrobial resistance, defined by the WHO as “resistance of a micro-organism to an antibiotic to which it was previously sensitive”, results from the ability of the bacterium to withstand the attack of antibiotics. This resistance is a major factor in the risk of therapeutic failure and the spread of multidrug-resistant strains from animals to humans. The present study was aimed to assess the antibiotic resistance of strains of Escherichia coli and Salmonella sp. Isolated from cattle farms in the Department of Vina, Cameroon.

Place and Duration of Study: The study involved 30 strains of Salmonella (05) and Escherichia coli (25) isolated from 60 samples of raw cow milk, collected from July to August 2021 in Vina, Adamawa Province. The samples were each made up of 15 ml of milk, taken aseptically from cattle farms and sales depots.

Methodology: Antibiotic susceptibility of 25 strains of Escherichia coli and 5 Salmonella sp. strains was wanted, according to the standard Mueller-Hinton agar diffusion method 16 antibiotic discs.

Results: The diameters of the inhibition zones formed showed fairly high resistance rates, 87.5% for Salmonella sp. and 75% for E. coli. Bacterial strains are all resistant to the Penicillin, Macrolides and Diaminopyrimidines tested. Good sensitivity was observed with levofloxacin (100%), cefixime (82.14%) and gentamycin (78.60%).

Conclusion: The importance of these resistances reflects the intensive previous use of antibiotics in livestock farming as growth-promoting additives.