Draft Genome-Sequence-Based Genomic Characterization of Salmonella enterica subsp. enterica serovar Oslo Isolated from Clinical Samples in South India and a Comparison with Global Isolates.

Non-typhoidal Salmonellae are significant foodborne pathogens with ≥2,600 serovars and a diverse range of hosts, which significantly increases the chances of infection in humans. Salmonella enterica subsp. enterica serovar Oslo (S. Oslo) is a rare serovar associated with foodborne illnesses. Here, we aim to report the draft, whole-genome sequences of S. Oslo ST2344 and ST1370 with reduced ciprofloxacin susceptibility, isolated from clinical samples. Thirty S. Oslo isolates were identified following the standard microbiological techniques. Twenty-six of the thirty (86.66%) S. Oslo isolates were pan-susceptible to the antimicrobials examined, while four isolates showed decreased ciprofloxacin susceptibility (minimum inhibitory concentration: 0.12-0.50 µg/mL). Pulsed-field gel electrophoresis analysis showed strains were heterogeneous with the two sequence types of ST1370 and ST2344, which were observed in multilocus sequence typing . The average genome size of the four S. Oslo isolates ranged from 4,760,441 to 5,002,787 bp, with an average G+C content of 52%. Different virulence genes encompassing Salmonella Pathogenicity Island 1 to 5 linked to disease pathogenesis were found by genome analysis. The draft genome of S. Oslo clinical isolates provides insight into the molecular characteristics of the S. Oslo currently prevalent in India, and the phylogenetic analysis sheds light on their evolutionary pattern.