The microbiome and antibiotic resistance in pasteurized camel milk

Abstract

Raw milk contains bacteria that can cause spoilage and have implications on human health. Although pasteurization is one of the main strategies employed in the dairy industry to kill these pathogens, the spore-forming bacteria are not effectively eliminated by this process. Moreover, post pasteurization, the extracellular antibiotic resistance genes (ARGs) can be transmitted to other bacteria. This study investigated the microbiome, antibiotic resistance profile, and ARGs potential transmission in pasteurized camel milk in Kuwait using shotgun sequencing. Forty pasteurized milk samples were purchased from Kuwait supermarkets and analyzed as composite samples. The results showed that spoilage and pathogenic spore-forming bacteria dominated the bacterial population of pasteurized camel milk with Bacillus and Paenibacillus constituting 40.94% and 34.27% of the population, respectively. ARGs that confer resistance to 11 classes of antibiotics mainly glycopeptide antibiotic (48.63%) and tetracycline (15.07%) were identified. Genera hosting ARGs were predicted with Paenibacillus being the most frequent genus with a mean abundance 46.8%. Moreover, the results suggested that the ARGs conferring resistance to peptide antibiotics, tetracycline, glycopeptide, and lincosamide may be transmitted to other bacteria due to their close proximity to mobile genetic elements. These findings highlight the food safety concerns associated with the consumption of pasteurized camel milk and underline the need to control the prevalence of spore-forming bacteria and extend the shelf life of pasteurized milk through the use of effective milk processing strategies.