Role in virulence and protective efficacy in pigs of Salmonella enterica serovar Typhimurium secreted components identified by signature-tagged mutagenesis

Carnell, Sonya; Bowen, Alison J.; Morgan, Elfed; Maskell, Duncan J.; Wallis, Timothy S.; Stevens, Mark P.

doi:10.1099/mic.0.2006/006726-0

Cited by 75 publications

(85 citation statements)

References 54 publications

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“…Signature-tagged transposon mutagenesis (STM; Hensel et al 1995) has markedly accelerated the assignment of roles to Salmonella genes in vivo. By this method S. Typhimurium transposon mutants were screened in parallel for their ability to colonize the intestines of mice and calves (260 mutants; Tsolis et al 1999) and calves, chickens and pigs (1045 mutants; Morgan et al 2004;Carnell et al 2007). Importantly, these studies revealed that Salmonella deploys both conserved-and host-specific colonization factors.…”

Section: Molecular Basis Of Intestinal Colonization Of Food-producingmentioning

confidence: 99%

Molecular insights into farm animal and zoonoticSalmonellainfections

Stevens

Humphrey

Maskell

2009

Phil. Trans. R. Soc. B

145

102

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Salmonella enterica is a facultative intracellular pathogen of worldwide importance. Infections may present in a variety of ways, from asymptomatic colonization to inflammatory diarrhoea or typhoid fever depending on serovar-and host-specific factors. Human diarrhoeal infections are frequently acquired via the food chain and farm environment by virtue of the ability of selected non-typhoidal serovars to colonize the intestines of food-producing animals and contaminate the avian reproductive tract and egg. Colonization of reservoir hosts often occurs in the absence of clinical symptoms; however, some S. enterica serovars threaten animal health owing to their ability to cause acute enteritis or translocate from the intestines to other organs causing fever, septicaemia and abortion. Despite the availability of complete genome sequences of isolates representing several serovars, the molecular mechanisms underlying Salmonella colonization, pathogenesis and transmission in reservoir hosts remain ill-defined. Here we review current knowledge of the bacterial factors influencing colonization of food-producing animals by Salmonella and the basis of host range, differential virulence and zoonotic potential.

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Section: Molecular Basis Of Intestinal Colonization Of Food-producingmentioning

confidence: 99%

Molecular insights into farm animal and zoonoticSalmonellainfections

Stevens

Humphrey

Maskell

2009

Phil. Trans. R. Soc. B

145

102

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“…As this mutant was not attenuated in either the chick or calf model of infection this may reflect the ability of the bacteria to express different adhesions to exploit different animal hosts. 81 Several genes under the control of the PhoPQ two-component system (TCS) were identified in this screen. The Salmonella PhoPQ TCS is known to regulate a number of genes that play a role in growth in low Mg 2+ , resistance to antimicrobial peptides, bile salts and acid pH.…”

Section: Salmonella Entericamentioning

confidence: 99%

“…80 The remaining 40 transposon mutants were associated only with attenuation in the pig model of infection. 81 One of the mutants identified had a transposon insertion in safA gene. This gene is part of an operon (safABCD) which is located within the Salmonella enterica centisome 7 genomic island (SCI) also known as SPI-6.…”

Section: Salmonella Entericamentioning

confidence: 99%

“…81 This screen identified 119 mutants attenuated for virulence in the porcine model of infection. Of these 119 mutants, the transposon insertion site of 79 had been identified in the previous screen.…”

Section: Salmonella Entericamentioning

confidence: 99%

“…This raises the possibility that this system may play a role in colonization of pigs by Salmonella. 81 In recent years STM has been improved by modifying the mutagenizing transposon to include a T7 RNA polymerase promoter (P T7 ) that is used to generate a unique transcript for each mutant from the genomic sequence adjacent to the mutation. This modification makes exogenous unique sequence tags unnecessary.…”

Section: Salmonella Entericamentioning

confidence: 99%

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Signature tagged mutagenesis in the functional genetic analysis of gastrointestinal pathogens

Cummins

Gahan

2012

Gut Microbes

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Signature tagged mutagenesis is a genetic approach that was developed to identify novel bacterial virulence factors. It is a negative selection method in which unique identification tags allow analysis of pools of mutants in mixed populations. The approach is particularly well suited to functional genetic analysis of the gastrointestinal phase of infection in foodborne pathogens and has the capacity to guide the development of novel vaccines and therapeutics. In this review we outline the technical principles underpinning signature-tagged mutagenesis as well as novel sequencing-based approaches for transposon mutant identification such as TraDIS (transposon directed insertion-site sequencing). We also provide an analysis of screens that have been performed in gastrointestinal pathogens which are a global health concern (Escherichia coli, Listeria monocytogenes, Helicobacter pylori, Vibrio cholerae and Salmonella enterica). The identification of key virulence loci through the use of signature tagged mutagenesis in mice and relevant larger animal models is discussed.

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