Detection and Characterization of spp. in Raw Commingled Bulk Tank Milk from Dairies in Pennsylvania.

A microbiological survey was conducted to determine the presence of spp. in raw commingled bulk tank milk (BTM) collected from the Pennsylvania dairies intended for pasteurization. The survey found 8.1% (10/123) of samples positive for Cerro was the predominant serovar and genetic analysis of the Cerro showed the existence of diverse yet closely related genotypes. Antibiotic susceptibility testing conducted on all isolates showed pan-susceptible pattern against 15 drugs covering 9 drug classes. The study helped determine the presence of spp. in the commingled BTM, antibiotic susceptibility patterns, and serovars along with genotypic diversity among the predominant serovar, Cerro.