Role of sigma factor E in regulation of Salmonella Agf expression

Yoo, Ah Young; Yu, Jinghua; Yoo, Hyung Joun; Lee, Tae Ho; Lee, Woon Ho; Oh, Jun-Hyok; Kang, Ho Young

doi:10.1016/j.bbrc.2012.11.025

Cited by 18 publications

(14 citation statements)

References 30 publications

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“…The high frequency of lpfA and agfA were similar to other data obtained by previous works that studied different serovars , Borsoi et al 2009, Cesco 2010. Besides being important in the adhesion during the infection process, the agfA gene is also associated with biofilm formation (Barnhart & Chapman 2006, Yoo et al 2013. Our results show this gene is present in isolates from carcasses, which can pose greater risk of contamination on the slaughterhouses.…”

Section: Discussionmentioning

confidence: 77%

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

et al. 2013

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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.

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Section: Discussionmentioning

confidence: 77%

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

et al. 2013

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“…Similar studies with different Salmonella serovars have shown the presence of the agf A gene in over 91.4%, the lfp A gene in 80.63%, and the three genes together in more than 73.34% of strains isolated from birds. The frequency of virulence determinants and the establishment of genetic profiles of isolates help to determine effective control protocols and prevention measures in the industry [ 15 , 23 , 24 ].…”

Section: Resultsmentioning

confidence: 99%

Salmonella enterica Serovar Minnesota Biofilms, Susceptibility to Biocides, and Molecular Characterization

et al. 2021

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The presence of virulence genes, phylogenetic relationships, biofilm formation index (BFI), and ultrastructure in S. Minnesota at different temperatures (4, 25, and 36 °C) were analyzed. In addition, the ability of biocidal agents (chlorhexidine1%, sodium hypochlorite 1%, and peracetic acid 0.8%) to inhibit biofilms formed by 20 strains isolated from broiler slaughter plants from two Brazilian companies in 2009, 2010, and 2014 was determined. The presence of specific genes was evaluated by PCR and phylogeny between strains by pulsed-field gel electrophoresis. The BFI was determined using tryptone soy broth with 5% of chicken juice, and its structure was observed by scanning electron microscopy. The presence of specific genes indicated that S. Minnesota has the potential to cause disease in humans, adapting to adverse conditions. Temperatures of 25 and 36 °C favored biofilm formation, although at 4 °C, there was still biomass that could contaminate the final product. Tolerance to all biocides was identified in 12/20 (60%), representing a real risk of adaptation mechanisms development, especially regarding to resistance to sodium hypochlorite. Phylogenetic analysis indicated cross-contamination and spread among companies, which was probably related to biofilms formation. Results show the necessity of attention to this serovar considering its resistance to sodium hypochlorite, including the need for rigorous control, adopting low temperatures to prevent biofilms formation in the poultry industry.

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“…σ E is involved in sensing mis-folded pilin subunits in E. coli (Jones et al 1997) and regulates aggregative fimbriae in Salmonella typhimurium (Yoo et al 2013). The RseA protein has been hypothesized to control biofilm-associated genes in response to envelope stress mediated by conjugative pili in E. coli (Yang et al 2008) and to control extracellular polysaccharide adhesin by Actinobacillus pleuropneumoniae (Bossé et al 2010).…”

Section: Resultsmentioning

confidence: 99%

Exploitation of a “hockey-puck” phenotype to identify pilus and biofilm regulators in Serratia marcescens through genetic analysis

2016

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Pili are essential adhesive determinants for many bacterial pathogens. A suppressor mutation screen that takes advantage of a pilus-mediated self-aggregative “hockey-puck” colony phenotype was designed to identify novel regulators of type I pili in Serratia marcescens. Mutations that decreased pilus biosynthesis mapped to the fimABCD operon; to the genes alaT, fkpA, and oxyR; upstream of the flagellar master regulator operon flhDC; and to an uncharacterized gene encoding a predicted DUF1401 domain. biofilm formation and pilus-dependent agglutination assays were used to characterize the relative importance of the identified genes in pilus biosynthesis. Additional mutagenic or complementation analysis was used to verify the role of candidate genes in pilus biosynthesis. Presented data support a model that CRP negatively regulates pilus biosynthesis through increased expression of flhDC and decreased expression of oxyR. Further studies are warranted to determine the mechanism by which these genes mediate pilus biosynthesis or function.

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Role of sigma factor E in regulation of Salmonella Agf expression

Cited by 18 publications

References 30 publications

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

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

Salmonella enterica Serovar Minnesota Biofilms, Susceptibility to Biocides, and Molecular Characterization

Exploitation of a “hockey-puck” phenotype to identify pilus and biofilm regulators in Serratia marcescens through genetic analysis

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