Drug Resistance, Characterization and Phylogenetic Discrepancy of Salmonella enterica Isolates from Distinct Sources

Salmonella enterica is one of the foodborne pathogens that can infect humans, spreading from one person to another by contaminated food and water. To identify the pathogenic S. enterica from the contaminated food product, culture-based and molecular identifications, drug resistance profiling, virulence and genetic traits of the strains have been used. Herein, different animal products was subjected to screen for S. enterica prevalence, pathogenic characterization and compared with clinical Salmonella isolates (human). A total of 173 isolates from animal products and 51 isolates from clinical samples were collected. S. Typhi, S. Agona and S. Ohio were predominant serovars in blood, stool and different animal products. Both, clinical [37% (n = 19/51)] and animal product-associated isolates [21% (n = 37/173)] expressed their highest resistance to nalidixic acid. Thirty-one percentage of (n = 16/51) clinical isolates and 12% (n = 21/173) animal food-associated isolates were resistant to multiple classes of antibiotics. Class 1 integrons encoded by S. Typhi, S. Infantis and S. Emek were screened for sequence analysis, the result revealed that the cassettes encoded-aminoglycoside acetyltransferase and dihydrofolate reductase enzymes. Salmonella pathogenicity island-1 encoded-hilA gene was detected most frequently in all the isolates. PFGE profile revealed the genetic traits of the isolates which were closely linked with antibiotic-resistant properties and virulent characteristics. Only S. Enteritidis, collected from different samples had clonal similarities. In summary, drug-resistant pathogenic Salmonella prevalence was observed in the animal product that could be an important alarm to consumers with the risk of enteric fever and it causes the potential risk to public health.