The pathogenic potential and genetic attributes of Escherichia coli in milk from dairy cows with subclinical mastitis

Abstract

The centrality of milk and dairy products to the human diet allows potential pathogens to pose a threat to human health. Pathogenic Escherichia coli is a zoonotic foodborne pathogen with many virulence genes which cause variations in its pathogenicity. The current study aimed to investigate the pathogenic potential of E. coli from milk of dairy cows with subclinical mastitis and evaluate the genetic relatedness to E. coli from human sources. The majority of the E. coli isolates belonged to the A (55.0%) and B2 (22.5%) phylogenetic groups and the most prevalent virulence genes were colV (90.0%), fyuA (75.0%) and vat (42.5%). Mice injected with G4-BD23 (P < 0.05) and G5-BD3 had lower survival rates than controls and visible pathological changes to lung and kidney. Nineteen MLST types were identified in 40 dairy E. coli isolates and three STs (ST10, ST48 and ST942) were shared with those from human sources. Some dairy E. coli isolates were phylogenetically related to human E. coli isolates indicating pathogenic potential.

Keywords:

• Public health
• Escherichia coli
• pathogenic potential
• phylogenetic analysis
• virulence genes
• genetic relatedness

Acknowledgments

We thank the Animal Clinical Laboratory of Hebei Agricultural University for providing the technical support. The authors would like to express their gratitude to EditSprings (https://www.editsprings.cn) for the expert linguistic services provided.

Disclosure statement

The authors declare no potential conflicts of interest with respect to the research, authorship, or publication of this article.

Data availability statement

The original sequences we used for primer sequences design can be found in GenBank (https://www.ncbi.nlm.nih.gov/genbank/) under the accession numbers in Table 1.

Additional information

Funding

This research was supported by Hebei key research and development program (19226611D).