Molecular Characterization of Salmonella spp. Isolates from Wild Colombian Babilla (Caiman crocodilus fuscus) Isolated In Situ

Abstract

Salmonella enterica is a pathogen capable of colonizing various environments, including the intestinal tract of different animals such as mammals, birds, and reptiles, which can act as carriers. S. enterica infection induces different clinical diseases, gastroenteritis being the most common, which in some cases, can evolve to septicemia and meningitis. Reptiles and amphibians have been reported as a reservoir of Salmonella, and transmission of the pathogen to humans has been documented. This study aimed to determine the presence of virulence genes and characterize the genotypic antibiotic resistance profile in Salmonella strains isolated from Caiman crocodilus fuscus obtained in situ (natural habitat) in Prado, Tolima, Colombia in a previous study and stored in a strain bank in our laboratory. Fifteen Salmonella strains were evaluated through endpoint PCR to determine the presence of resistance genes and virulence genes. The genes blaTEM, strB, and sul1 were detected in all the strains that confer resistance to ampicillin, streptomycin, and sulfamethoxazole, as well as the virulence genes invA, pefA, prgH, spaN, tolC, sipB, sitC, pagC, msgA, spiA, sopB, sifA, lpfA, csgA, hilA, orgA, iroN, avrA, and sivH, indicating the possible role of babilla (Caiman crocodilus fuscus) as a carrier of multidrug-resistant bacteria.

The Role of Birds in Salmonellosis

“…The emergence of antimicrobial-resistant strains in birds is a growing concern [41]. The increase in antimicrobial-resistant strains of Salmonella in avian species is a burgeoning concern that substantially impacts the well-being of animals and humans.…”

Virulence genes identification in Salmonella enterica isolates from humans, crocodiles, and poultry farms from two regions in Colombia

“…Moreover, genes on chromosomes, Salmonella pathogenicity islands (SPIs), mobile genetic elements (i.e., transposons, plasmids, and bacteriophages), and pili [12]; that code for adaptation to the host cell, resistance to antimicrobials, and the ability to overcome host defense mechanisms encoded virulence factors [7,12]. Preliminary studies have established the presence and resistance to antibiotics of different serotypes of S. enterica in the poultry industry in Tolima and Santander departments, Available at www.veterinaryworld.org/Vol.16/October-2023/11.pdf as well as in various isolates from humans and crocodiles (Caiman crocodilus) in the department of Tolima [9,[13][14][15][16]. To improve the understanding of the virulence profile and establish strategies that contribute to the control and prevention of salmonellosis, this study aimed to identify virulence genes in S. enterica isolates from patients with gastroenteritis, chicken carcasses and cloacal swabs, and crocodiles from two regions in Colombia.…”