Revista de Medicina y Cirugía Veterinaria Acceso abierto

Abstracto

Assessment of Bacterial Contamination and Antibiotic Susceptibility Patterns of Bacteria Isolated from Milk collected from Biharwe in Mbarara District: Cross-Sectional Study

Nathan Mugenyi1*, Martin Amanya2, Pius Stewart Ssebagala3, Desire Kisembo3, Fortunate Kabuuye Joseph3, Prize Ninsiima4

Introduction: Bacterial contamination in milk is increasingly becoming a global health threat that is predisposing humans to various food borne pathogens. This study is carried out to isolate and identify the possible common bacteria which cause milk contamination and the risks associated with it in Biharwe.

Methods: A cross-sectional study was carried out in Biharwe small holder dairy farms, Kashari Sub County, Mbarara district, from March 2022 to October 2022 to assess bacterial contamination, isolate, identify, and test antibiotic susceptibility patterns of organisms. A total of 20 milk samples were randomly collected from 20 privately owned small holder dairy farms with healthy lactating animals. Isolation and identification of organisms was carried out by using biochemical tests. The bacteria so identified and their isolation rate were E. coli (20%), Citrobacter freundii (40%), Enterobacter Cloacae (30%), Enterobacter agglomerans (10%). These are indicative of significant contamination of milk and important human pathogens. The antibiotic susceptibility test was performed on Mueller-Hinton agar by the Kirby-Bauer disk diffusion method. About 100 % of E. coli isolates was sensitive to Tetracycline with 0% resistance, 75% of Citrobacter freundii was sensitive to Tetracycline with 25% resistant isolates, 100% of Entrobacter cloacae was sensitive to Tetracycline with 0% resistance, and 100% of E. agglomerans was sensitive with 0% resistance. Overall 90% of the isolates were sensitive to Tetracycline with only 10% resistance. All the bacterial isolates were 100% sensitive to Gentamicin with 0% resistant. 100% of Citrobacter freundii, Entrobacter cloacae and Enterobacter agglomerans isolates were resistant to Ampicillin while only 50% of E. coli isolates was sensitive to Ampicillin. 100% of Entrobacter cloacae, E. coli and Enterobacter agglomerans isolates were sensitive to Streptomycin while 75% of Citrobacter freundii was sensitive and 25% was resistant to Streptomycin. Citrobacter freundii was the only isolated organism resistant to more than one antibiotic (100% resistant to Ampicillin and 25% resistant to Tetracycline and Streptomycin). Therefore, the pattern of antibiotic susceptibility tests among the isolates is statistically significant in Gentamicin (P=0.00).

Conclusion: This study revealed that raw cow’s milk in the study area could be an important source of infection with a wide range of organisms, particularly gram-negative bacteria. An important source of microbial contamination of milk is fecal pollution probably cow dung. There is need for instituting effective control measures to protect public health. This includes mandatory milk pasteurization by traders and improved hygienic handling of containers during milking, ensuring milking is not done on floors with cow dung.