Detection of virulence-associated genes in Salmonella Enteritidis isolates from chicken in South of Brazil

Abstract

RESUMO.-[Detecção de genes associados à virulência em cepas de Salmonella Enteritidis isoladas de frangos na região sul do Brasil.] Salmonella spp. estão entre os principais agentes causadores de doenças transmitidas por alimentos, e o sorovar Salmonella Enteritidis é o mais frequentemente isolado no mundo. A virulência de Salmonella spp. e a sua interação com o hospedeiro são processos complexos que envolvem fatores de virulência para sobreviver às defesas do hospedeiro. O objetivo deste estudo foi detectar genes de virulência em cepas de S. Enteritidis isoladas a partir de fontes avícolas no sul do Brasil. Ensaios de PCR foram desenvolvidos para a detecção de nove genes (lpfA, agfA, sefA, invA, hilA, avrA, sopE, sivH are considered the main agents of foodborne disease and Salmonella Enteritidis is one of the most frequently isolated serovars worldwide. The virulence of Salmonella spp. and their interaction with the host are complex processes involving virulence factors to overcome host defenses. The purpose of this study was to detect virulence genes in S. Enteritidis isolates from poultry in the South of Brazil. PCR-based assays were developed in order to detect nine genes (lpfA, agfA, sefA, invA, hilA, avrA, sopE, sivH and spvC) associated with the virulence in eighty-four isolates of S. Enteritidis isolated from poultry. The invA, hilA, sivH, sefA and avrA genes were present in 100% of the isolates; lpfA and sopE were present in 99%; agfA was present in 96%; and the spvC gene was present in 92%. It was possible to characterize the isolates with four different genetic profiles (P1, P2, P3 and P4), as it follows: P1, positive for all genes; P2, negative only for spvC; P3, negative for agfA; and P4, negative for lpfA, spvC and sopE. The most prevalent profile was P1, which was present in 88% of the isolates. Although all isolates belong to the same serovar, it was possible to observe variations in the presence of these virulence-associated genes between different isolates. The characterization of the mechanisms of virulence circulating in the population of Salmonella Enteritidis is important for a better understanding of its biology and pathogenicity. The frequency of these genes and the establishment of genetic profiles can be used to determine patterns of virulence. These patterns, associated with in vivo studies, may help develop tools to predict the ability of virulence of different strains.

Detection of virulence genes of Salmonella in diarrhoeic ducks by using Polymerase chain reaction

“…Table 7 revealed that all isolates from diarrheic and slaughtered ducks harbor invA gene and amplified at 284bp fragments. These results were agreed with Borges et al [21] S. Typhimurium isolated from diarrheic ducks had pef gene and had 60%pathogenicity in mice , but S. Typhimurium isolated from slaughtered ducks had no genes and lower in pathogenicity in mice 40%. Also S. Virchow isolated from diarrheic ducks contain no pef gene although it differ in pathogenicity 40% in adults and 60% in small ducks and also S. Kentucky from diarrheic ducks one contain pef gene and other had no gene although pathogenicity in both 60% , S. Infants had no stn gene and not enterotoxigenic , S. Virchow had stn gene and not enterotoxigenic (this indicated that may gene not expressed).…”

Occurrence of ingression of Salmonella spp. in Betel leaf (Piper betle L.)

“…spvC gene (located on virulence plasmid) product promotes rapid growth and survival of Salmonella spp. within host cells (Borges et al 2013). Results showed that the prevalence of invasion (sefA and invA) and TTSS associated genes (hila, avrA and sopE) are high in internalized Salmonella isolates which indicates probable mechanisms of internalization of the isolates.…”

Avaliação da capacidade de produção de biofilmes e detecção da enzima KPC em Salmonella spp. isoladas de aviário e linha de abate de aves

“…In the evaluation of biofilm production, it was used the polyethylene microplates and capsule production technique according to Stepanovic et al (2004) and Rodrigues et al (2006), respectively. The virulence factors of salmonella were researched, represented by the genes IpfA, agfA, sefA, invA, hilA, avrA, sopE, sivH,e spvC, using the Polymerase Chain Reaction (PCR) method described by Borges et al (2013). The lineages were submitted to the carbapenems antibiotic resistence test by the disk diffusion method with carbapenems according to the Clinical and Laboratory Standards Institute-CLSI (2010), and the research of the resistance to carbapenems gene bla KCP , by the strains Salmonella spp.…”

“…Os genes utilizados na presente pesquisa (Tabela 2) foram selecionados com base em estudo realizado por Borges et al (2013) Borges et al (2013) e NCBI (2014) Para a extração do DNA transferiu-se 1mL da cultura ativa para um tubo tipo Eppendorf. O tubo foi submetido à centrifugação por 4min a 9000rpm, o sobrenadante foi descartado e o pallet ressuspendido em 100µL de água deionizada estéril.…”

“…Assim sendo, a presente pesquisa objetivou a verificação da capacidade de estirpes de Salmonella spp isoladas de aviário e linha de abate de frangos de um frigorífico no estado do Rio Grande do Sul produzirem biofilmes e apresentarem resistência a antibióticos carbapenêmicos. Na avaliação da produção de biofilme, foi empregada a técnica de microplacas de polietileno e produção de cápsula segundo Stepanovic et al (2004) e Rodrigues et al (2006), respectivamente.Foram pesquisados os fatores de virulência de salmonelas, representados pelos genes IpfA, agfA, sefA, invA, hilA, avrA, sopE, sivH,e spvC, utilizando o método de Reação de cadeia de Polimerase (PCR), descrita por Borges et al (2013). As estirpes foram submetidas ao teste de resistência a antibióticos carbapenêmicos pelo método de disco difusão com carbapenêmicos segundo Clinical and Laboratory Standards Institute-CLSI (2010) e pesquisa do gene de resistência a carbapenêmicos bla KCP , pela técnica de PCR, segundo NAAS et al (2007).…”