Comparative Genomic Analysis of 450 Strains of Isolated from Diseased Animals.

is a leading cause of bacterial infections in animals and humans. We sequenced a collection of 450 strains from diseased animals to better understand the genetic makeup of their virulence and resistance features. The presence of pathogenicity islands (SPIs) varied by serotype. . Enteritidis carried the most SPIs ( = 15), while . Mbandaka, . Cerro, Meleagridis, and . Havana carried the least ( = 10). Typhimurium, Choleraesuis, . I 4,5,12:i:-, and Enteritidis each contained the operon on IncFII or IncFII-IncFIB hybrid plasmids. Two IIIa carried a operon with deletion on the chromosome. Twelve plasmid types including 24 hybrid plasmids were identified. IncA/C was frequently associated with Newport (83%) and . Agona (100%) from bovine, whereas IncFII (100%), IncFIB (100%), and IncQ1 (94%) were seen in . Choleraesuis from swine. IncX (100%) was detected in all . Kentucky from chicken. A total of 60 antimicrobial resistance genes (ARGs), four disinfectant resistances genes (DRGs) and 33 heavy metal resistance genes (HMRGs) were identified. The strains from sick animals contained various SPIs, resistance genes and plasmid types based on the serotype and source of the isolates. Such complicated genomic structures shed light on the strain characteristics contributing to the severity of disease and treatment failures in infections, including those causing illnesses in animals.