Abstract

Salmonella sp. is an important worldwide zoonotic agent, frequently isolated among reptile microbiota. This genus has ever-growing importance to public and animal health, as well as food hygiene. In the present study, cloacal swabs were collected from Caiman latirostris individuals; 103 samples from animals captive in two different colonies and 12 from animals in the wild. All animals were sexed, and total length was measured at sampling. Swabs were inoculated in Tetrathionate broth and were cultured in MacConkey and XLT4 agars, and incubated at 37°C, for the isolation of Salmonella spp. Samples isolated were characterized according to their biochemical profile using API 20E (BioMérieux). Serotyping was performed according to the Kauffman-White method, and the pattern of susceptibility to antibiotics was verified using the disk diffusion method. Presence of four virulence genes (invA, spvC, sefC e pef) was assessed using Multiplex-PCR. Correlations between the presence of Salmonella spp., gender, and total length were also analyzed. Frequency of animals positive for Salmonella spp. among captive animals was 30% and 48.38%, respectively. The agent was detected in 50% of the animals in the wild. There were significantly more positive males than females in one of the captivity sites and in the other, a significant correlation between the presence of the bacteria, and total length was observed. There were no significant differences in incidence of Salmonella spp. between captive and wild Caiman latirostris. A total of 45 Salmonella spp. samples from 15 different serotypes were isolated: S. infantis, S. typhimurium, S. grumpensis, S. cerro, S. anatum, S. agona, S. enterica subsp. enterica. (O: 13, 23), S. coeln, S. enterica subsp. enterica (rough strain), S. enteritidis, S. newport, S. minnesota, S. enterica subsp. enterica (O: 6, 8: ch: -), S. enterica subsp. enterica (O: 4, 12: ch: -), S. schwarzengrund. All of them were in the subspecies Salmonella enterica subsp. enterica (Group I). In general, strains were sensitive to all antibiotics tested, but resistances were observed for cotrimoxazole, chloranfenicol, neomycin, gentamicin, and tetracycline in five samples of Salmonella spp. isolated from captivity. There were also three multiresistant strains in captivity (S. infantis, S. typhimurium, and S. grumpensis). In relation to virulence genes, all samples presented the invA gene, S. enteritidis presented all genes studied and in S. enterica subsp. enterica (rough strain) was detected the genes invA and sefC.