Molecular Characterization of Y. enterocolitica Isolated from Dairy Environment with Special Reference to the Antimicrobial Activity of Milk Proteins Hydrolysates

Abstract

Yersinia species, especially Yersinia enterocolitica, are considered as the most prevalent milk-borne pathogens. Y. enterocolitica is the causative agent of yersiniosis, a zoonotic disease of growing epidemiological importance with significant consequences for public health. A total of 300 samples out of milk and milk products water and environmental samples were collected from dairy cattle rural house and local dairy shops and vendors to be investigated for presence of Yersinia spp. Isolates were molecularly identified and screened for virulence markers, biofilm production and antimicrobial resistance profile. Finally, the antimicrobial activity of milk proteins hydrolysates against Y. enterocolitica was detected. Yersinia spp. was recovered from 50% of the examined samples. The most prevalent species was Y. enterocolitica (isolated from 21.7 and 30% of milk and its products, and environmental samples, respectively). Detection of virulence genes revealed that 24% of Y. enterocolitica isolates harbored both ail and yst genes. Y. enterocolitica isolates showed high antimicrobial resistance to various antimicrobials. Also, different biofilm phenotypes were produced by these isolates. The most produced biofilm phenotype was moderate (68.9%). The parent proteins (CCP, CWP) and their pepsin hydrolysates (P-CCP and P-CWP) were potentially effective in inhibiting Y. enterocolitica growth and peptides P-CWP exhibited the strongest effect against Y. enterocolitica.

Keywords

• yersinia enterocolitica
• virulence and antimicrobial resistance
• milk & milk products
• dairy environment
• biofilm formation
• antimicrobial biopeptides