scholarly journals Salmonella enterica’s “Choice”: Itaconic Acid Degradation or Bacteriocin Immunity Genes

Genes ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 797
Author(s):  
Rolf D. Joerger
Keyword(s):  
Itaconic Acid ◽  
Isocitrate Lyase ◽  
Open Reading Frames ◽  
Metabolic Inhibitor ◽  
Pathogen Invasion ◽  
Genomic Location ◽  
Serovar Typhimurium ◽  
Immunity Genes ◽  
Salmonella Genome ◽  
Uncompetitive Inhibitor

Itaconic acid is an immunoregulatory metabolite produced by macrophages in response to pathogen invasion. It also exhibits antibacterial activity because it is an uncompetitive inhibitor of isocitrate lyase, whose activity is required for the glyoxylate shunt to be operational. Some bacteria, such as Yersinia pestis, encode enzymes that can degrade itaconic acid and therefore eliminate this metabolic inhibitor. Studies, primarily with Salmonella enterica subspecies enterica serovar Typhimurium, have demonstrated the presence of similar genes in this pathogen and the importance of these genes for the persistence of the pathogen in murine hosts. This minireview demonstrates that, based on Blast searches of 1063 complete Salmonella genome sequences, not all Salmonella serovars possess these genes. It is also shown that the growth of Salmonella isolates that do not possess these genes is sensitive to the acid under glucose-limiting conditions. Interestingly, most of the serovars without the three genes, including serovar Typhi, harbor DNA at the corresponding genomic location that encodes two open reading frames that are similar to bacteriocin immunity genes. It is hypothesized that these genes could be important for Salmonella that finds itself in strong competition with other Enterobacteriacea in the intestinal tract—for example, during inflammation.

scholarly journals Global Transcriptional Analysis of Dehydrated Salmonella enterica Serovar Typhimurium

2012 ◽  
Vol 78 (22) ◽  
pp. 7866-7875 ◽  
Author(s):  
Nadia Gruzdev ◽  
Michael McClelland ◽  
Steffen Porwollik ◽  
Shany Ofaim ◽  
Riky Pinto ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Lipid A ◽  
Isocitrate Lyase ◽  
Protein Biosynthesis ◽  
Potassium Transport ◽  
Transcriptional Analysis ◽  
Scaffolding Protein ◽  
Transport Channel ◽  
Content Type ◽  
Serovar Typhimurium

ABSTRACTDespite the scientific and industrial importance of desiccation tolerance inSalmonella, knowledge regarding its genetic basis is still scarce. In the present study, we performed a transcriptomic analysis of dehydrated and water-suspendedSalmonella entericaserovar Typhimurium using microarrays. Dehydration induced expression of 90 genes and downregulated that of 7 genes. Ribosomal structural genes represented the most abundant functional group with a relatively higher transcription during dehydration. Other main induced functional groups included genes involved in amino acid metabolism, energy production, ion transport, transcription, and stress response. The highest induction was observed in thekdpFABCoperon, encoding a potassium transport channel. Knockout mutations were generated in nine upregulated genes. Five mutants displayed lower tolerance to desiccation, implying the involvement of the corresponding genes in the adaptation ofSalmonellato desiccation. These included genes encoding the isocitrate-lyase AceA, the lipid A biosynthesis palmitoleoyl-acyltransferase Ddg, the modular iron-sulfur cluster scaffolding protein NifU, the global regulator Fnr, and the alternative sigma factor RpoE. Notably, these proteins were previously implicated in the response ofSalmonellato oxidative stress, heat shock, and cold shock. A strain with a mutation in the structural genekdpAhad a tolerance to dehydration comparable to that of the parent strain, implying that potassium transport through this system is dispensable for early adaptation to the dry environment. Nevertheless, this mutant was significantly impaired in long-term persistence during cold storage. Our findings indicate the involvement of a relatively small fraction of theSalmonellagenome in transcriptional adjustment from water to dehydration, with a high prevalence of genes belonging to the protein biosynthesis machinery.

scholarly journals Differences in Enzymatic Properties Allow SodCI but Not SodCII To Contribute to Virulence in Salmonella enterica Serovar Typhimurium Strain 14028

2004 ◽  
Vol 186 (16) ◽  
pp. 5230-5238 ◽  
Author(s):  
Radha Krishnakumar ◽  
Maureen Craig ◽  
James A. Imlay ◽  
James M. Slauch
Keyword(s):  
Salmonella Enterica ◽  
Osmotic Shock ◽  
Acid Resistance ◽  
Noncovalent Interaction ◽  
Open Reading Frames ◽  
Striking Difference ◽  
Significant Difference ◽  
Serovar Typhimurium

ABSTRACT Salmonella enterica serovar Typhimurium produces two Cu/Zn cofactored periplasmic superoxide dismutases, SodCI and SodCII. While mutations in sodCI attenuate virulence eightfold, loss of SodCII does not confer a virulence phenotype, nor does it enhance the defect observed in a sodCI background. Despite this in vivo phenotype, SodCI and SodCII are expressed at similar levels in vitro during the stationary phase of growth. By exchanging the open reading frames of sodCI and sodCII, we found that SodCI contributes to virulence when placed under the control of the sodCII promoter. In contrast, SodCII does not contribute to virulence even when expressed from the sodCI promoter. Thus, the disparity in virulence phenotypes is due primarily to some physical difference between the two enzymes. In an attempt to identify the unique property of SodCI, we have tested factors that might affect enzyme activity inside a phagosome. We found no significant difference between SodCI and SodCII in their resistance to acid, resistance to hydrogen peroxide, or ability to obtain copper in a copper-limiting environment. Both enzymes are synthesized as apoenzymes in the absence of copper and can be fully remetallated when copper is added. The one striking difference that we noted is that, whereas SodCII is released normally by an osmotic shock, SodCI is “tethered” within the periplasm by an apparently noncovalent interaction. We propose that this novel property of SodCI is crucial to its ability to contribute to virulence in serovar Typhimurium.

scholarly journals Complete DNA Sequence and Comparative Analysis of the 50-Kilobase Virulence Plasmid of Salmonella entericaSerovar Choleraesuis

2001 ◽  
Vol 69 (4) ◽  
pp. 2612-2620 ◽  
Author(s):  
Takeshi Haneda ◽  
Nobuhiko Okada ◽  
Noriko Nakazawa ◽  
Takatoshi Kawakami ◽  
Hirofumi Danbara
Keyword(s):  
Comparative Analysis ◽  
Systemic Infection ◽  
Open Reading Frames ◽  
Virulence Plasmid ◽  
Sequence Element ◽  
E Coli ◽  
Virulence Plasmids ◽  
Serovar Typhimurium ◽  
Insertion Sequence Element ◽  
Reading Frames

ABSTRACT The complete nucleotide sequence of pKDSC50, a large virulence plasmid from Salmonella enterica serovar Choleraesuis strain RF-1, has been determined. We identified 48 of the open reading frames (ORFs) encoded by the 49,503-bp molecule. pKDSC50 encodes a known virulence-associated operon, the spv operon, which is composed of genes essential for systemic infection by nontyphoidalSalmonella. Analysis of the genetic organization of pKDSC50 suggests that the plasmid is composed of several virulence-associated genes, which include the spvRABCD genes, plasmid replication and maintenance genes, and one insertion sequence element. A second virulence-associated region including the pef(plasmid-encoded fimbria) operon and rck (resistance to complement killing) gene, which has been identified on the virulence plasmid of S. enterica serovar Typhimurium, was absent. Two different replicon regions, similar to the RepFIIA and RepFIB replicons, were found. Both showed high similarity to those of the pO157 plasmid of enterohemorrhagic Escherichia coliO157:H7 and the enteropathogenic E. coli (EPEC) adherence factor plasmid harbored by EPEC strain B171 (O111:NM), as well as the virulence plasmids of Salmonella serovars Typhimurium and Enteritidis. Comparative analysis of the nucleotide sequences of the 50-kb virulence plasmid of serovar Choleraesuis and the 94-kb virulence plasmid of serovar Typhimurium revealed that 47 out of 48 ORFs of the virulence plasmid of serovar Choleraesuis are highly homologous to the corresponding ORFs of the virulence plasmid of serovar Typhimurium, suggesting a common ancestry.

scholarly journals Antibiotic Resistance Conferred by a Class I Integron and SXT Constin in Vibrio cholerae O1 Strains Isolated in Laos

2004 ◽  
Vol 48 (7) ◽  
pp. 2364-2369 ◽  
Author(s):  
Masaaki Iwanaga ◽  
Claudia Toma ◽  
Tomoko Miyazato ◽  
Sithat Insisiengmay ◽  
Noboru Nakasone ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Vibrio Cholerae ◽  
Hot Spot ◽  
Antibiotic Resistance Gene ◽  
Gene Cassette ◽  
Drug Susceptibility ◽  
Open Reading Frames ◽  
Class I ◽  
Serovar Typhimurium ◽  
Vibrio Cholerae O1

ABSTRACT Changes in the drug susceptibility pattern were observed in Vibrio cholerae O1 isolated in the Lao People's Democratic Republic during 1993 to 2000. In this study, 50 V. cholerae O1 strains were selected during this period for studying the presence of class I integron and SXT constin. Twenty-four streptomycin-resistant strains out of 26 isolated before 1997 contained a class I integron harboring the aadA1 gene cassette. Twenty-four strains isolated after 1997 contained an SXT constin (a large conjugative element). Twenty of the strains were resistant to chloramphenicol, tetracycline, streptomycin, and trimethoprim-sulfamethoxazole, while four strains were susceptible to the antibiotic tested. The resistance genes included in the SXT constins were floR, tetA, strAB, and sulII, which encode resistance to chloramphenicol, tetracycline, streptomycin, and sulfamethoxazole, respectively. The antibiotic resistance gene cluster was found to be deleted in the four susceptible strains. SXTLAOS did not contain dfrA1 or dfr18, which confer resistance to trimethoprim in SXTET and SXTMO10, respectively. A hot spot region of SXTLAOS was sequenced, and we identified two novel open reading frames showing homology to sO24 (exonuclease) and sO23 (helicase) of the genomic island associated with the multidrug resistance region of Salmonella enterica serovar Typhimurium DT104. Analysis of SXTLAOS showed that there is a continuous flux of genes among V. cholerae SXT constins which should be carefully monitored.

scholarly journals Salmonellagenomic island 3 is an integrative and conjugative element and contributes to copper and arsenic resistance ofSalmonella enterica

2019 ◽  
Author(s):  
Nobuo Arai ◽  
Tsuyoshi Sekizuka ◽  
Yukino Tamamura ◽  
Masahiro Kusumoto ◽  
Atsushi Hinenoya ◽  
...  
Keyword(s):  
Mobile Genetic Element ◽  
Open Reading Frames ◽  
Trna Genes ◽  
Sequencing Analysis ◽  
Arsenic Resistance ◽  
Filter Mating ◽  
Serovar Typhimurium ◽  
Resistance Island ◽  
Reading Frames ◽  
Integrative And Conjugative Element

ABSTRACTSalmonellagenomic island 3 (SGI3) was first described as a chromosomal island inSalmonella4,[5],12:i:-, a monophasic variant ofSalmonella entericasubsp.entericaserovar Typhimurium. The SGI3 DNA sequence detected fromSalmonella4,[5],12:i:-isolated in Japan was identical to that of a previously reported one across entire length of 81 kb. SGI3 consists of 86 open reading frames, including a copper homeostasis and silver resistance island (CHASRI) and an arsenic resistance operon in addition to genes related to conjugative transfer and DNA replication or partitioning, suggesting that the island is a mobile genetic element. We successfully selected transconjugants that acquired SGI3 after filter mating experiments using theS. entericaserovars Typhimurium, Heidelberg, Hadar, Newport, Cerro, and Thompson as recipients. Southern blot analysis using I-CeuI-digested genomic DNA demonstrated that SGI3 was integrated into a chromosomal fragment of the transconjugants. PCR and sequencing analysis demonstrated that SGI3 was inserted into the 3′ end of the tRNA genespheVorpheR. The length of the target site was 52 or 55 bp, and a 55-bpattIsequence indicating generation of the circular form of SGI3 was also detected. The transconjugants had a higher MIC against CuSO4compared with the recipient strains under anaerobic conditions. Resistance was defined by thecusgene cluster in the CHASRI. The transconjugants also had distinctly higher MICs against Na2HAsO4compared with recipient strains under aerobic conditions. These findings clearly demonstrate that SGI3 is an integrative and conjugative element and contributes to the copper and arsenic resistance ofS. enterica.

scholarly journals Analysis of the Organization of Multicopy Linear- and Circular-Plasmid-Carried Open Reading Frames inBorrelia burgdorferi Sensu Lato Isolates

1998 ◽  
Vol 66 (3) ◽  
pp. 1149-1158 ◽  
Author(s):  
Jason A. Carlyon ◽  
Crystal LaVoie ◽  
Shian-Ying Sung ◽  
Richard T. Marconi
Keyword(s):  
Southern Hybridization ◽  
Fragment Length Polymorphism ◽  
Pulsed Field Gel Electrophoresis ◽  
Open Reading Frames ◽  
Homogeneous Electric Field ◽  
Related Sequence ◽  
Circular Plasmid ◽  
Genomic Location ◽  
Single Primer ◽  
Reading Frames

ABSTRACT Plasmid cp8.3 of Borrelia afzelii IP21 carries several open reading frames (ORFs) and a 184-bp inverted repeat (IR) element. It has been speculated that this plasmid may encode factors involved in virulence or infectivity. In this report, we have characterized the distribution, molecular variability, and organization of ORFs 1, 2, and 4 and the IR elements among isolates of the Borrelia burgdorferi sensu lato complex. ORFs 1 and 2 are contained within a segment of cp8.3 that is bordered by the IR elements, while ORF 4 resides just outside of the IR-bordered region. By PCR, ORF 4 was amplified from most isolates while ORFs 1 and 2 were amplified from only some B. afzelii isolates. However, Southern hybridization analyses with ORF 1, 2, and 4 probes detected related sequences even in some isolates that were PCR negative. The ORF restriction fragment length polymorphism patterns varied widely even among isolates of the same species. Two-dimensional contour-clamped homogeneous electric field–pulsed-field gel electrophoresis and Southern hybridization detected ORF 1-, 2-, and 4-related sequences on linear and circular plasmids. In addition, an ORF 4-related sequence was detected on a previously uncharacterized, circular plasmid that is greater than 70 kb in size. The IR elements originally identified on plasmid cp8.3 of B. afzelii IP21 were also analyzed by Southern hybridization. Related sequences were detected in some but not all B. burgdorferi sensu lato isolates. These sequences are carried on plasmids in addition to cp8.3 in some isolates. Single-primer PCR analyses demonstrated that in some isolates these sequences exist with IR orientation. The data presented here demonstrate that the IR elements and the ORF 1-, 2-, and 4-related sequences are multicopy and are variable in organization and in genomic location among isolates of the B. burgdorferi sensu lato complex. These analyses provide additional evidence for the highly variable organization of the plasmid component of the B. burgdorferi sensu lato genome.

scholarly journals SalmonellaGenomic Island 3 Is an Integrative and Conjugative Element and Contributes to Copper and Arsenic Tolerance ofSalmonella enterica

2019 ◽  
Vol 63 (9) ◽  
Author(s):  
Nobuo Arai ◽  
Tsuyoshi Sekizuka ◽  
Yukino Tamamura ◽  
Masahiro Kusumoto ◽  
Atsushi Hinenoya ◽  
...  
Keyword(s):  
Open Reading Frames ◽  
Trna Genes ◽  
Sequencing Analysis ◽  
Content Type ◽  
Arsenic Tolerance ◽  
Filter Mating ◽  
Serovar Typhimurium ◽  
Resistance Island ◽  
Reading Frames ◽  
Integrative And Conjugative Element

ABSTRACTSalmonellagenomic island 3 (SGI3) was first described as a chromosomal island inSalmonella4,[5],12:i:–, a monophasic variant ofSalmonella entericasubsp.entericaserovar Typhimurium. The SGI3 DNA sequence detected fromSalmonella4,[5],12:i:– isolated in Japan was identical to that of a previously reported one across entire length of 81 kb. SGI3 consists of 86 open reading frames, including a copper homeostasis and silver resistance island (CHASRI) and an arsenic tolerance operon, in addition to genes related to conjugative transfer and DNA replication or partitioning, suggesting that the island is a mobile genetic element. We successfully selected transconjugants that acquired SGI3 after filter-mating experiments using theS. entericaserovars Typhimurium, Heidelberg, Hadar, Newport, Cerro, and Thompson as recipients. Southern blot analysis using I-CeuI-digested genomic DNA demonstrated that SGI3 was integrated into a chromosomal fragment of the transconjugants. PCR and sequencing analysis demonstrated that SGI3 was inserted into the 3′ end of the tRNA genespheVorpheR. The length of the target site was 52 or 55 bp, and a 55-bpattIsequence indicating generation of the circular form of SGI3 was also detected. The transconjugants had a higher MIC against CuSO4compared to the recipient strains under anaerobic conditions. Tolerance was defined by thecusgene cluster in the CHASRI. The transconjugants also had distinctly higher MICs against Na2HAsO4compared to recipient strains under aerobic conditions. These findings clearly demonstrate that SGI3 is an integrative and conjugative element and contributes to the copper and arsenic tolerance ofS. enterica.

scholarly journals Identification of GtgE, a Novel Virulence Factor Encoded on the Gifsy-2 Bacteriophage of Salmonella enterica Serovar Typhimurium

2002 ◽  
Vol 184 (19) ◽  
pp. 5234-5239 ◽  
Author(s):  
Theresa D. Ho ◽  
Nara Figueroa-Bossi ◽  
Minhua Wang ◽  
Sergio Uzzau ◽  
Lionello Bossi ◽  
...  
Keyword(s):  
Virulence Factor ◽  
Salmonella Enterica ◽  
Virulence Genes ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Systemic Infection ◽  
Open Reading Frames ◽  
Effector Protein ◽  
Protein Sequence Analysis ◽  
Serovar Typhimurium ◽  
Reading Frames

ABSTRACT The Gifsy-2 temperate bacteriophage of Salmonella enterica serovar Typhimurium contributes significantly to the pathogenicity of strains that carry it as a prophage. Previous studies have shown that Gifsy-2 encodes SodCI, a periplasmic Cu/Zn superoxide dismutase, and at least one additional virulence factor. Gifsy-2 encodes a Salmonella pathogenicity island 2 type III secreted effector protein. Sequence analysis of the Gifsy-2 genome also identifies several open reading frames with homology to those of known virulence genes. However, we found that null mutations in these genes did not individually have a significant effect on the ability of S. enterica serovar Typhimurium to establish a systemic infection in mice. Using deletion analysis, we have identified a gene, gtgE, which is necessary for the full virulence of S. enterica serovar Typhimurium Gifsy-2 lysogens. Together, GtgE and SodCI account for the contribution of Gifsy-2 to S. enterica serovar Typhimurium virulence in the murine model.

scholarly journals Identification of RpoS (ςS)-Regulated Genes inSalmonella enterica Serovar Typhimurium

2000 ◽  
Vol 182 (20) ◽  
pp. 5749-5756 ◽  
Author(s):  
Magdalena Ibanez-Ruiz ◽  
Véronique Robbe-Saule ◽  
Daniel Hermant ◽  
Séverine Labrude ◽  
Françoise Norel
Keyword(s):  
Dna Methyltransferase ◽  
Open Reading Frames ◽  
Gene Fusions ◽  
Start Site ◽  
E Coli ◽  
Methylguanine Dna Methyltransferase ◽  
Serovar Typhimurium ◽  
Flanking Regions ◽  
Type Strains ◽  
Genetic Rearrangements

ABSTRACT The rpoS gene encodes the alternative sigma factor ςS (RpoS) and is required for survival of bacteria under starvation and stress conditions. It is also essential forSalmonella virulence in mice. Most work on the RpoS regulon has been in the closely related enterobacterial speciesEscherichia coli. To characterize the RpoS regulon inSalmonella, we isolated 38 unique RpoS-activatedlacZ gene fusions from a bank of Salmonella enterica serovar Typhimurium mutants harboring random Tn5B21 mutations. Dependence on RpoS varied from 3-fold to over 95-fold, and all gene fusions isolated were regulated by growth phase. The identities of 21 RpoS-dependent fusions were determined by DNA sequence analysis. Seven of the fusions mapped to DNA regions inSalmonella serovar Typhimurium that do not match any knownE. coli sequence, suggesting that the composition of the RpoS regulon differs markedly in the two species. The other 14 fusions mapped to 13 DNA regions very similar to E. coli sequences. None of the insertion mutations in DNA regions common to both species appeared to affect Salmonella virulence in BALB/c mice. Of these, only three (otsA, katE, andpoxB) are located in known members of the RpoS regulon. Ten insertions mapped in nine open reading frames of unknown function (yciF, yehY, yhjY,yncC, yjgB, yahO, ygaU,ycgB, and yeaG) appear to be novel members of the RpoS regulon. One insertion, that in mutant C52::H87, was in the noncoding region upstream from ogt, encoding aO 6-methylguanine DNA methyltransferase involved in repairing alkylation damage in DNA. The ogt coding sequence is very similar to the E. coli homolog, but the ogt 5′ flanking regions were found to be markedly different in the two species, suggesting genetic rearrangements. Using primer extension assays, a specificogt mRNA start site was detected in RNAs of theSalmonella serovar Typhimurium wild-type strains C52 and SL1344 but not in RNAs of the mutant strains C52K (rpoS), SL1344K (rpoS), and C52::H87. In mutant C52::H87, Tn5B21 is inserted at the ogt mRNA start site, with lacZ presumably transcribed from the identified RpoS-regulated promoter. These results indicate that ogtgene expression in Salmonella is regulated by RpoS in stationary phase of growth in rich medium, a finding that suggests a novel role for RpoS in DNA repair functions.

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