The Transmission of Strains in Dairy Herds in Different Housing Systems.

Cattle are frequent carriers of spp.; therefore, these bacteria may be transmitted to humans through meat or milk. spp. in raw milk derives most commonly from secondary fecal contamination during the milking process; however, the udder excretion of may be a cause of milk-borne infection. Studies were carried out on a -positive farm with two different housing systems (with free-stall and tie-stall systems). The sampling process comprised several stages, including samples being taken from animals, such as from raw milk and feces, and from the environment, such as the from floor in the milking parlor and from teat cups. None of the individual raw milk samples or swabs from the floor in the parlor before the milking process were positive for spp. Simultaneously, spp. was isolated from all swabs from the floor after the milking process and in the bulk tank milk samples from the two farms. The incidence of isolated from fecal and teat swab samples ranged from 15.4% to 26.7% and from 8.9% to 25%, respectively. Altogether, 59 recovered isolates were classified, based on sequencing of the short variable region, showing 15 different allele types, and the majority of them were distributed among one farm. Analysis of the virulence and antimicrobial properties showed that genes related to adherence, invasion and cytotoxicity were widely distributed among the recovered strains. In relation to AMR, multidrug resistance was noted in 16.1% of strains.