Antimicrobial resistant Brucella spp. prevail in raw milk and animal feces of different livestock farms.

BACKGROUND

Brucella spp. is a zoonotic pathogen that affects both livestock and humans, causing reproductive issues in animals and severe health complications in humans, including undulant fever, hepatomegaly, and arthritis. Contaminated raw milk and feces serve as potential transmission sources, despite its public health significance, limited studies have assessed the prevalence of Brucella spp. in raw milk and feces, particularly in endemic regions like Pakistan.

OBJECTIVE

This study aimed to determine the prevalence of Brucella spp. in raw milk and feces of livestock in Punjab and Islamabad Capital Territory, Pakistan, and evaluate the antibiotic resistance profiles of the isolated strains.

METHODS

The raw milk and fecal samples were collected randomly from the different livestock farms of Punjab, Pakistan. The areas were selected based on the different sociodemographic attributes like climate, land usage, number of animals, husbandry practices and operational convenience, which may influence the spatial and temporal distribution of livestock diseases. Brucella spp. was isolated using Brucella agar, a highly specific medium, and confirmed at the molecular level through IS711 gene analysis. Antibiotic susceptibility testing was performed to determine the multiple antibiotic resistance (MAR) index and identify multidrug-resistant (MDR) strains.

RESULTS

A total of 100 samples, including 60 raw milk samples (cows = 25, buffalo = 25, goats = 10) and 40 fecal samples (cows = 16, buffalo = 15, goats = 9), were collected from various livestock farms. The incidence of Brucella spp. was found higher (7.5%) in raw milk than in the animal´s feca (15%). All the strains showed multiple antibiotic resistance (MAR) index (0.3-0.5) which was higher than the critical value (> 0.2). Additionally, 75% of the strains were classified as multidrug-resistant (MDR), highlighting their resistance to multiple antibiotics.

CONCLUSION

These findings indicate the antimicrobial resistance and prevalence of Brucella spp. in the dairy industry which could be a serious threat to public health.

CLINICAL TRIAL NUMBER: Not applicable.