Title: Repression of flagella is a common trait in field isolates of Salmonella enterica serovar Dublin and is associated with invasive human infections Author:Yim, Lucía; Sasías, Sebastián; Martínez, Arací; Betancor, Laura; Estevez, Verónica; Scavone, Paola; Bielli, Alejandro; Sirok, Alfredo; Chabalgoity, José Alejandro Subject:Flagella -- Physiology ; Salmonella Infections -- Microbiology ; Salmonella Enterica -- Pathogenicity Description:
The nontyphoidal Salmonella enterica serovar Dublin is adapted to cattle but infrequently infects humans, very often resulting in invasive infections with high levels of morbidity and mortality. A Salmonella-induced intestinal acute inflammatory response is postulated as a mechanism to prevent bacterial dissemination to systemic sites. In S. enterica serovar Typhimurium, flagella contribute to this response by providing motility and FliC-mediated activation of pattern recognition receptors. In this study, we found 4 Salmonella enterica isolates, with the antigenic formula 9,12:-:-, that, based on fliC sequence and multilocus sequence type (MLST) analyses, are aflagellate S. Dublin isolates. Interestingly, all were obtained from human bloodstream infections. Thus, we investigated the potential role of flagella in the unusual invasiveness exhibited by S. Dublin in humans by analyzing flagellation and proinflammatory properties of a collection of 10 S. Dublin human clinical isolates. We found...
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Infection and immunity, April 2014, Vol.82(4), pp.1465-76
1098-5522 (E-ISSN); 24421045 Version (PMID); 10.1128/IAI.01336-13 (DOI)
Title: Genomic Comparison of the Closely Related Salmonella enterica Serovars Enteritidis and Dublin Author:Betancor, Laura; Yim, Lucía; Martínez, Arací; Fookes, Maria; Sasias, Sebastian; Schelotto, Felipe; Thomson, Nicholas; Maskell, Duncan; Chabalgoity, José A Subject:Comparative Genomics ; Host Specificity ; Pseudogenes ; S. Dublin ; S. Enteritidis. ; Salmonella Description:
The Enteritidis and Dublin serovars of Salmonella enterica are closely related, yet they differ significantly in pathogenicity and epidemiology. S. Enteritidis is a broad host range serovar that commonly causes gastroenteritis and infrequently causes invasive disease in humans. S. Dublin mainly colonizes cattle but upon infecting humans often results in invasive disease.To gain a broader view of the extent of these differences we conducted microarray-based comparative genomics between several field isolates from each serovar. Genome degradation has been correlated with host adaptation in Salmonella, thus we also compared at whole genome scale the available genomic sequences of them to evaluate pseudogene composition within each serovar.Microarray analysis revealed 3771 CDS shared by both serovars while 33 were only present in Enteritidis and 87 were exclusive to Dublin. Pseudogene evaluation showed 177 inactive CDS in S. Dublin which correspond to active genes in S. Enteritidis, nine of...
Is part of:
The open microbiology journal, 2012, Vol.6, pp.5-13
1874-2858 (E-ISSN); 22371816 Version (PMID); 10.2174/1874285801206010005 (DOI)
Title: A Naturally Occurring Deletion in FliE from Salmonella enterica Serovar Dublin Results in an Aflagellate Phenotype and Defective Proinflammatory Properties Author:Sasías, Sebastián; Martínez-Sanguiné, Adriana; Betancor, Laura; Martínez, Arací; D'Alessandro, Bruno; Iriarte, Andrés; Chabalgoity, José A; Yim, Lucía Subject:Flie ; Salmonella ; Flagella ; Proinflammatory Capacity ; Serovar Dublin ; Bacterial Proteins -- Genetics ; Flagella -- Genetics ; Salmonella Enterica -- Genetics ; Sequence Deletion -- Genetics Description:
serovar Dublin is adapted to cattle but is able to infect humans with high invasiveness. An acute inflammatory response at the intestine helps to prevent dissemination to systemic sites. Flagella contribute to this response by providing motility and FliC-mediated signaling through pattern recognition receptors. In a previous work, we reported a high frequency (11 out of 25) of Dublin isolates lacking flagella in a collection obtained from humans and cattle. The aflagellate strains were impaired in their proinflammatory properties and The aim of this work was to elucidate the underlying cause of the absence of flagella in Dublin isolates. We report here that class 3 flagellar genes are repressed in the human aflagellate isolates, due to impaired secretion of FliA anti-sigma factor FlgM. This phenotype is due to an in-frame 42-nucleotide deletion in the gene, which codes for a protein located in the flagellar basal body. The deletion is predicted to produce a protein lacking amino...
Is part of:
Infection and immunity, January 2018, Vol.86(1)
1098-5522 (E-ISSN); 29061704 Version (PMID); 10.1128/IAI.00517-17 (DOI)