Genetic Relationship between Salmonella Isolates Recovered from Calves and Broilers Chickens in Kafr El-Sheikh City Using ERIC PCR

A prevalent bacterial intestinal infection with severe economic damage is salmonellosis. Our study was carried out to diagnose Salmonella from chickens and calves, to determine its resistance to antimicrobials' phenotypic and genotypic characterization of integrons and beta lactamase genes in the multidrug resistance of different Salmonella serotypes, and to detect the genetic relationship between Salmonella isolates collected from different origins using an ERIC PCR. In total, 200 samples from diseased chicken and diarrheic calves were obtained from 50 various farms from Kafr El-sheikh, Egypt. Salmonella poultry isolates were characterized as S. Typhimurium (3/8), S. Enteritidis (3/8), and S. Kentucky (2/8), but Salmonella isolates from cattle were S. Enteritidis (1/2) and S. Kentucky (1/2). When antibiotic susceptibility testing was completed on all of the isolates, it showed that there was multidrug resistance present (MDR). A PCR was applied for identifying the accompanying class 1 integrons and ESBLs from MDR Salmonella isolates (two isolates of S. Kentucky were divided as one from calf and one from poultry). Our results detected blaTEM and class 1 integron, but were negative for bla IMP, bla VIM, and bla SHV. An ERIC PCR was conducted for understanding the clonal relation between various beta-lactamase-producing MDR Salmonella isolates. The same four previously mentioned isolates were also tested. The two isolates of S. Enteritidis isolated from poultry and calves had 100% similarity despite indicating that there were interactions between broilers and calves living on the same farm that caused infection from the same Salmonella strains, while the other two isolates of S. Kentucky showed only 33% serovarities.

Automated summary

The study aimed to diagnose Salmonella from chickens and calves, determine its resistance to antimicrobials, characterize integrons and beta lactamase genes in MDR Salmonella, and detect genetic relationships between isolates using ERIC PCR. Results showed MDR in Salmonella isolates and the presence of blaTEM and class 1 integron genes. ERIC PCR revealed clonal relationships between isolates, with S. Enteritidis isolates from poultry and calves showing 100% similarity, indicating possible cross-infection between animals on the same farm, while S. Kentucky isolates showed lower serovarities.