Occurrence of Virulence and Resistance Genes in Salmonella in Cloacae of Slaughtered Chickens and Ducks at Pluck Shops in Trinidad

Abstract

The study used PCR to determine the molecular basis of the antibiotic resistance and virulence profiles of isolates of Salmonella by targeting genes encoding for carriage and persistence in the poultry. A total of 1503 cecal samples from poultry were collected, 91 (6.1%) were positive for Salmonella spp. Ten different serotypes were detected from Salmonella isolates. The study was also conducted to determine the occurrence of 13 virulence and 12 resistance genes in isolates of Salmonella spp. All 46 isolates of Salmonella spp. tested were positive to one or more of the 12 virulence genes detected, ranging from 0.0% (viaB) to 100.0% (invA, mgtB, pipA and spi4D) (P<0.05). Occurrence of virulence genes varied significantly (P<0.05) by serotype but not by animal species. Of the 12 resistance genes assayed, only 4 (33.3%), strA, ampC, cmy2 and qnrB were detected. Overall, the occurrence of detection resistance genes was 71.7% (33/46), with 87.1% and 40.0% of the isolates from chickens and ducks, respectively positive (p=0.0009). The occurrence of resistance gene ranged from 2.2% (cmy2) to 50.0% (qnrB) in resistance gene positive isolates. The findings provide evidence that poultry from pluck shops are colonized by pathogenic Salmonella harboring virulence and antimicrobial resistance genes which may have clinical and therapeutic consequences, if the genes detected are expressed. Although there is a need for prudent use of antimicrobial agents in poultry production systems which should be constant monitoring for the prevalence of resistance in Salmonella isolates using phenotypic methods, the importance and knowledge of the occurrence of resistance genes in the pathogen in Trinidad cannot be ignored.

Molecular characterization of virulence and resistance genes in Salmonella strains isolated from chickens sold at the informal chicken market in Gauteng Province, South Africa

“…Both invA and sopE are encoded by SPI-1, which is involved in host invasion, and the frequency of detection of sopE (79.1%) in the current study is lower than the 99% found in chickens in Brazil (Borges et al, 2013) but higher than the 67.7% detected in Trinidad (Kumar et al, 2021). SopE, an effector for translocation, contributes to the expression of Salmonella invasion by stimulating membrane ruffling (Bakshi et al, 2000).…”

“…The mgtB gene, found in 87.3% of our isolates and 90.9% of the patterns, has been reported at higher frequencies by others elsewhere such as 100% in Trinidad and China (Kumar et al, 2021; Zhang et al, 2018). However, lower frequencies of the mgtB gene have been reported by others (Liu et al, 2012).…”

“…However, Kumar et al (2021) detected 12 (92.3%) of 13 virulence genes assayed in Salmonella isolates recovered from ‘pluck shop’ outlets in Trinidad and Tobago, and Elkenany et al (2019) found 8 (80%) of 10 virulence genes assayed in Egypt. Furthermore, the frequency of the individual virulence genes assayed was in agreement with our findings, where the frequency of the virulence genes detected varied significantly by the sources and types of samples (0.4%: sefC ‐ 100%: invA ) (Awad et al, 2020; Kumar et al, 2021; Wang, Wang, et al, 2020). It has been suggested that these variations may influence the type of Salmonella infection manifested, whether systemic or enteric (Ulaya, 2013).…”

“…Virulence genes encoded in SPI-1 to SPI-5, detection frequency, and their activities in the pathogenicity of Salmonella spp. recovered from chickens or cases of human salmonellosis have been well documented in the literature (Kumar et al, 2021;Pavon et al, 2022;Zishiri et al, 2016). The frequency and types of virulence genes in Salmonella isolated from poultry are variable across countries (Kumar et al, 2021;Lozano-Villegas et al, 2023;Zishiri et al, 2016).…”

Salmonella in Pig Farms and on Pig Meat in Suriname

“…We could not find a single study on antimicrobial resistance genes in Salmonella from pigs in the Caribbean, and only few on Salmonella as a whole in the Caribbean. In poultry strains in Trinidad, a quite higher prevalence of resistance was found compared to our study, and this included plasmid-mediated colistin resistance [36][37][38].…”