Oral immunization with a dam mutant of Yersinia pseudotuberculosis protects against plague

Microbiology ◽  
2005 ◽  
Vol 151 (6) ◽  
pp. 1919-1926 ◽  
Author(s):  
Victoria L. Taylor ◽  
Richard W. Titball ◽  
Petra C. F. Oyston
Keyword(s):  
Gene Expression ◽  
Bile Salts ◽  
Yersinia Pseudotuberculosis ◽  
Lethal Dose ◽  
Oral Immunization ◽  
Wild Type ◽  
Gene Encoding ◽  
Serovar Typhimurium ◽  
Dna Adenine Methylase ◽  
Methylase Gene

Inactivation of the gene encoding DNA adenine methylase (dam) has been shown to attenuate some pathogens such as Salmonella enterica serovar Typhimurium and is a lethal mutation in others such as Yersinia pseudotuberculosis strain YPIII. In this study the dam methylase gene in Yersinia pseudotuberculosis strain IP32953 was inactivated. Unlike the wild-type, DNA isolated from the mutant could be digested with MboI, which is consistent with an altered pattern of DNA methylation. The mutant was sensitive to bile salts but not to 2-aminopurine. The effect of dam inactivation on gene expression was examined using a DNA microarray. In BALB/c mice inoculated orally or intravenously with the dam mutant, the median lethal dose (MLD) was at least 106-fold higher than the MLD of the wild-type. BALB/c mice inoculated with the mutant were protected against a subcutaneous challenge with 100 MLDs of Yersinia pestis strain GB and an intravenous challenge with 300 MLDs of Y. pseudotuberculosis IP32953.

scholarly journals Oral Immunization with an rfaH Mutant Elicits Protection against Salmonellosis in Mice

2004 ◽  
Vol 72 (7) ◽  
pp. 4297-4301 ◽  
Author(s):  
Gábor Nagy ◽  
Ulrich Dobrindt ◽  
Jörg Hacker ◽  
Levente Emödy
Keyword(s):  
Type Strain ◽  
Wild Type Strain ◽  
Lethal Dose ◽  
Fold Increase ◽  
Oral Immunization ◽  
Oral Infection ◽  
Wild Type ◽  
Virulence Attenuation ◽  
Serovar Typhimurium

ABSTRACT Loss of the transcriptional antiterminator RfaH results in virulence attenuation (>104-fold increase in 50% lethal dose) of the archetypal Salmonella enterica serovar Typhimurium strain SL1344 by both orogastric and intraperitoneal routes of infection in BALB/c mice. Oral immunization with the mutant efficiently protects mice against a subsequent oral infection with the wild-type strain. Interestingly, in vitro immunoreactivity is not confined to strain SL1344; rather, it is directed also towards other serovars of S. enterica and even Salmonella bongori strains.

scholarly journals Engineering and Preclinical Evaluation of Attenuated Nontyphoidal Salmonella Strains Serving as Live Oral Vaccines and as Reagent Strains

2011 ◽  
Vol 79 (10) ◽  
pp. 4175-4185 ◽  
Author(s):  
Sharon M. Tennant ◽  
Jin-Yuan Wang ◽  
James E. Galen ◽  
Raphael Simon ◽  
Marcela F. Pasetti ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Lethal Dose ◽  
Invasive Disease ◽  
Oral Immunization ◽  
Oral Vaccines ◽  
Wild Type ◽  
Lethal Challenge ◽  
Antibiotic Resistant ◽  
Content Type ◽  
Serovar Typhimurium

ABSTRACTWhile nontyphoidalSalmonella(NTS) has long been recognized as a cause of self-limited gastroenteritis, it is becoming increasingly evident that multiple-antibiotic-resistant strains are also emerging as important causes of invasive bacteremia and focal infections, resulting in hospitalizations and deaths. We have constructed attenuatedSalmonella entericaserovar Typhimurium andSalmonella entericaserovar Enteritidis strains that can serve as live oral vaccines and as “reagent strains” for subunit vaccine production in a safe and economical manner. Prototype attenuated vaccine strains CVD 1921 and CVD 1941, derived from the invasive wild-type strainsS. TyphimuriumI77 andS. EnteritidisR11, respectively, were constructed by deletingguaBA, encoding guanine biosynthesis, andclpP, encoding a master protease regulator. TheclpPmutation resulted in a hyperflagellation phenotype. An additional deletion infliDyielded reagent strains CVD 1923 and CVD 1943, respectively, which export flagellin monomers. Oral 50% lethal dose (LD50) analyses showed that the NTS vaccine strains were all highly attenuated in mice. Oral immunization with CVD 1921 or CVD 1923 protected mice against lethal challenge with wild-typeS. TyphimuriumI77. Immunization with CVD 1941 but not CVD 1943 protected mice against lethal infection withS. EnteritidisR11. Immune responses induced by these strains included high levels of serum IgG anti-lipopolysaccharide (LPS) and anti-flagellum antibodies, with titers increasing progressively during the immunization schedule. SinceS. TyphimuriumandS. Enteritidisare the most common NTS serovars associated with invasive disease, these findings can pave the way for development of a highly effective, broad-spectrum vaccine against invasive NTS.

scholarly journals Salmonella DNA Adenine Methylase Mutants Confer Cross-Protective Immunity

2001 ◽  
Vol 69 (11) ◽  
pp. 6725-6730 ◽  
Author(s):  
Douglas M. Heithoff ◽  
Elena Y. Enioutina ◽  
Raymond A. Daynes ◽  
Robert L. Sinsheimer ◽  
David A. Low ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Bile Salts ◽  
Protective Immunity ◽  
Humoral Response ◽  
Low Grade ◽  
Wild Type ◽  
Enhanced Sensitivity ◽  
Mutant Strains ◽  
Serovar Typhimurium ◽  
Dna Adenine Methylase

ABSTRACT Salmonella isolates that lack or overproduce DNA adenine methylase (Dam) elicited a cross-protective immune response to different Salmonella serovars. The protection afforded by the Salmonella enterica serovar Typhimurium Dam vaccine was greater than that elicited in mice that survived a virulent infection. S. enterica serovar Typhimurium Dam mutant strains exhibited enhanced sensitivity to mediators of innate immunity such as antimicrobial peptides, bile salts, and hydrogen peroxide. Also, S. enterica serovar Typhimurium Dam− vaccines were not immunosuppressive; unlike wild-type vaccines, they failed to induce increased nitric oxide levels and permitted a subsequent robust humoral response to diptheria toxoid antigen in infected mice. Dam mutant strains exhibited a low-grade persistence which, coupled with the nonimmunosuppression and the ectopic protein expression caused by altered levels of Dam, may provide an expanded source of potential antigens in vaccinated hosts.

scholarly journals The Response Regulator PhoP Is Important for Survival under Conditions of Macrophage-Induced Stress and Virulence in Yersinia pestis

2000 ◽  
Vol 68 (6) ◽  
pp. 3419-3425 ◽  
Author(s):  
Petra C. F. Oyston ◽  
Nick Dorrell ◽  
Kerstin Williams ◽  
Shu-Rui Li ◽  
Michael Green ◽  
...  
Keyword(s):  
Gene Expression ◽  
Yersinia Pestis ◽  
Pathogenic Bacteria ◽  
Yersinia Pseudotuberculosis ◽  
Bacterial Species ◽  
Lethal Dose ◽  
Wild Type ◽  
Virulence Gene Expression

ABSTRACT The two-component regulatory system PhoPQ has been identified in many bacterial species. However, the role of PhoPQ in regulating virulence gene expression in pathogenic bacteria has been characterized only in Salmonella species. We have identified, cloned, and sequenced PhoP orthologues from Yersinia pestis,Yersinia pseudotuberculosis, and Yersinia enterocolitica. To investigate the role of PhoP in the pathogenicity of Y. pestis, an isogenic phoPmutant was constructed by using a reverse-genetics PCR-based strategy. The protein profiles of the wild-type and phoP mutant strains, grown at either 28 or 37°C, revealed more than 20 differences, indicating that PhoP has pleiotrophic effects on gene expression in Y. pestis. The mutant showed a reduced ability to survive in J774 macrophage cell cultures and under conditions of low pH and oxidative stress in vitro. The mean lethal dose of the phoP mutant in mice was increased 75-fold in comparison with that of the wild-type strain, indicating that the PhoPQ system plays a key role in regulating the virulence of Y. pestis.

scholarly journals Salmonella Exploits Caspase-1 to Colonize Peyer's Patches in a Murine Typhoid Model

2000 ◽  
Vol 192 (2) ◽  
pp. 249-258 ◽  
Author(s):  
Denise M. Monack ◽  
David Hersh ◽  
Nafisa Ghori ◽  
Donna Bouley ◽  
Arturo Zychlinsky ◽  
...  
Keyword(s):  
Proinflammatory Cytokines ◽  
Mammalian Cells ◽  
Yersinia Pseudotuberculosis ◽  
Lethal Dose ◽  
Cysteine Proteases ◽  
Peyer's Patches ◽  
Peyer’S Patches ◽  
Wild Type ◽  
M Cell ◽  
Caspase 1

Salmonella typhimurium invades host macrophages and induces apoptosis and the release of mature proinflammatory cytokines. SipB, a protein translocated by Salmonella into the cytoplasm of macrophages, is required for activation of Caspase-1 (Casp-1, an interleukin [IL]-1β–converting enzyme), which is a member of a family of cysteine proteases that induce apoptosis in mammalian cells. Casp-1 is unique among caspases because it also directly cleaves the proinflammatory cytokines IL-1β and IL-18 to produce bioactive cytokines. We show here that mice lacking Casp-1 (casp-1−/− mice) had an oral S. typhimurium 50% lethal dose (LD50) that was 1,000-fold higher than that of wild-type mice. Salmonella breached the M cell barrier of casp-1−/− mice efficiently; however, there was a decrease in the number of apoptotic cells, intracellular bacteria, and the recruitment of polymorphonuclear lymphocytes in the Peyer's patches (PP) as compared with wild-type mice. Furthermore, Salmonella did not disseminate systemically in the majority of casp-1−/− mice, as demonstrated by significantly less colonization in the PP, mesenteric lymph nodes, and spleens of casp-1−/− mice after an oral dose of S. typhimurium that was 100-fold higher than the LD50. The increased resistance in casp-1−/− animals appears specific for Salmonella infection since these mice were susceptible to colonization by another enteric pathogen, Yersinia pseudotuberculosis, which normally invades the PP. These results show that Casp-1, which is both proapoptotic and proinflammatory, is essential for S. typhimurium to efficiently colonize the cecum and PP and subsequently cause systemic typhoid-like disease in mice.

scholarly journals Identification of New Flagellar Genes of Salmonella enterica Serovar Typhimurium

2006 ◽  
Vol 188 (6) ◽  
pp. 2233-2243 ◽  
Author(s):  
Jonathan Frye ◽  
Joyce E. Karlinsey ◽  
Heather R. Felise ◽  
Bruz Marzolf ◽  
Naeem Dowidar ◽  
...  
Keyword(s):  
Salmonella Enterica Serovar Typhimurium ◽  
Transcriptional Start Site ◽  
Null Alleles ◽  
Wild Type ◽  
Gene Encoding ◽  
Isolation And Characterization ◽  
Serovar Typhimurium ◽  
Chemotaxis Proteins ◽  
Flagellar Genes ◽  
Rna Levels

ABSTRACT RNA levels of flagellar genes in eight different genetic backgrounds were compared to that of the wild type by DNA microarray analysis. Cluster analysis identified new, potential flagellar genes, three putative methyl-accepting chemotaxis proteins, STM3138 (McpA), STM3152 (McpB), and STM3216(McpC), and a CheV homolog, STM2314, in Salmonella, that are not found in Escherichia coli. Isolation and characterization of Mud-lac insertions in cheV, mcpB, mcpC, and the previously uncharacterized aer locus of S. enterica serovar Typhimurium revealed them to be controlled by σ28-dependent flagellar class 3 promoters. In addition, the srfABC operon previously isolated as an SsrB-regulated operon clustered with the flagellar class 2 operon and was determined to be under FlhDC control. The previously unclassified fliB gene, encoding flagellin methylase, clustered as a class 2 gene, which was verified using reporter fusions, and the fliB transcriptional start site was identified by primer extension analysis. RNA levels of all flagellar genes were elevated in flgM or fliT null strains. RNA levels of class 3 flagellar genes were elevated in a fliS null strain, while deletion of the fliY, fliZ, or flk gene did not affect flagellar RNA levels relative to those of the wild type. The cafA (RNase G) and yhjH genes clustered with flagellar class 3 transcribed genes. Null alleles in cheV, mcpA, mcpB, mcpC, and srfB did not affect motility, while deletion of yhjH did result in reduced motility compared to that of the wild type.

scholarly journals Thermal Resistance and Gene Expression of both Desiccation-Adapted and Rehydrated Salmonella enterica Serovar Typhimurium Cells in Aged Broiler Litter

2017 ◽  
Vol 83 (12) ◽  
Author(s):  
Zhao Chen ◽  
Xiuping Jiang
Keyword(s):  
Gene Expression ◽  
Heat Treatment ◽  
Thermal Resistance ◽  
High Temperatures ◽  
Human Pathogens ◽  
Wild Type ◽  
Broiler Litter ◽  
Content Type ◽  
Serovar Typhimurium ◽  
Trehalose Synthesis

ABSTRACT The objective of this study was to investigate the thermal resistance and gene expression of both desiccation-adapted and rehydrated Salmonella enterica serovar Typhimurium cells in aged broiler litter. S. Typhimurium was desiccation adapted in aged broiler litter with a 20% moisture content (water activity [aw], 0.81) for 1, 2, 3, 12, or 24 h at room temperature and then rehydrated for 3 h. As analyzed by quantitative real-time reverse transcriptase PCR (qRT-PCR), the rpoS, proV, dnaK, and grpE genes were upregulated (P < 0.05) under desiccation stress and could be induced after 1 h but in less than 2 h. Following rehydration, fold changes in the levels of these four genes became significantly lower (P < 0.05). The desiccation-adapted ΔrpoS mutant was less heat resistant at 75°C than was the desiccation-adapted wild type (P < 0.05), whereas there were no differences in heat resistance between desiccation-adapted mutants in two nonregulated genes (otsA and PagfD) and the desiccation-adapted wild type (P > 0.05). Survival characteristics of the desiccation-adapted ΔPagfD (rdar [red, dry, and rough] morphotype) and ΔagfD (saw [smooth and white] morphotype) mutants were similar (P > 0.05). Trehalose synthesis in the desiccation-adapted wild type was not induced compared to a nonadapted control (P > 0.05). Our results demonstrated the importance of the rpoS, proV, dnaK, and grpE genes in the desiccation survival of S. Typhimurium. By using an ΔrpoS mutant, we found that the rpoS gene was involved in the cross-protection of desiccation-adapted S. Typhimurium against high temperatures, while trehalose synthesis or rdar morphology did not play a significant role in this phenomenon. In summary, S. Typhimurium could respond rapidly to low-aw conditions in aged broiler litter while developing cross-protection against high temperatures, but this process could be reversed upon rehydration. IMPORTANCE Physical heat treatment is effective in eliminating human pathogens from poultry litter used as biological soil amendments. However, prior to physical heat treatment, some populations of microorganisms may be adapted to the stressful conditions in poultry litter during composting or stockpiling, which may cross-protect them against subsequent high temperatures. Our previous study demonstrated that desiccation-adapted S. enterica cells in aged broiler litter exhibited enhanced thermal resistance. However, there is limited research on the underlying mechanisms of the extended survival of pathogens under desiccation conditions in animal wastes and cross-tolerance to subsequent heat treatment. Moreover, no information is available about the thermal resistance of desiccation-adapted microorganisms in response to rehydration. Therefore, in the present study, we investigated the gene expression and thermal resistance of both desiccation-adapted and rehydrated S. Typhimurium in aged broiler litter. This work will guide future research efforts to control human pathogens in animal wastes used as biological soil amendments.

scholarly journals Inactivation of the Stress- and Starvation-Inducible gls24 Operon Has a Pleiotrophic Effect on Cell Morphology, Stress Sensitivity, and Gene Expression inEnterococcus faecalis

2000 ◽  
Vol 182 (16) ◽  
pp. 4512-4520 ◽  
Author(s):  
Jean-Christophe Giard ◽  
Alain Rince ◽  
Herve Capiaux ◽  
Yanick Auffray ◽  
Axel Hartke
Keyword(s):  
Gene Expression ◽  
Bile Salts ◽  
Morphological Changes ◽  
Tap Water ◽  
Stress Protein ◽  
Biological Significance ◽  
Stress Sensitivity ◽  
Northern Analysis ◽  
Alkaline Stress ◽  
Wild Type

ABSTRACT Enterococcus faecalis induces the synthesis of at least 42 proteins during 24 h of glucose starvation. Because of its induction during carbohydrate and complete starvation (incubation in tap water) and CdCl2 and bile salts stresses, one of these proteins (Gls24) was qualified as a “general stress protein” and was analyzed at the molecular level. Its corresponding gene,gls24, seems to be the penultimate gene of an operon composed, altogether, of six open reading frames (ORFs). The ORF preceding gls24 (orf4) showed very strong identity with gls24. The deduced polypeptides of these two genes showed similarity with a 20-kDa hypothetical protein fromLactococcus lactis and an alkaline stress protein fromStaphylococcus aureus with no previously known biological significance. Data from the operon sequence and Northern analysis led to the conclusions that (i) gls24 possesses its own promoter which is especially induced at the onset of starvation and (ii) the operon promoter is stress inducible in exponential-phase cells. A mutation in the gls24 gene led to a severe reduction of growth rate and reduction of survival against 0.3% bile salts in the 24-h-starved cells compared to the wild-type strain. Moreover, the chain length of the mutant is significantly reduced during growth. These results argue strongly for a role of the protein Gls24 and/or GlsB in morphological changes and in stress tolerance inE. faecalis. Comparison of two-dimensional protein gels from wild-type cells with those from gls24 mutant cells revealed a pleiotropic effect of the mutation on gene expression. At least nine proteins were present in larger amounts in the mutant. For six of them, the corresponding N-terminal microsequence has been obtained. Three of these sequences map in genes coding forl-lactate dehydrogenase, lipoamide dehydrogenase, and pyruvate decarboxylase, all involved in pyruvate metabolism.

scholarly journals Braun Lipoprotein (Lpp) Contributes to Virulence of Yersiniae: Potential Role of Lpp in Inducing Bubonic and Pneumonic Plague

2008 ◽  
Vol 76 (4) ◽  
pp. 1390-1409 ◽  
Author(s):  
Jian Sha ◽  
Stacy L. Agar ◽  
Wallace B. Baze ◽  
Juan P. Olano ◽  
Amin A. Fadl ◽  
...  
Keyword(s):  
Acute Inflammation ◽  
Potential Role ◽  
Lethal Dose ◽  
Wild Type ◽  
Pneumonic Plague ◽  
Essentially Normal ◽  
Serovar Typhimurium ◽  
Highly Virulent ◽  
Lethal Doses

ABSTRACT Yersinia pestis evolved from Y. pseudotuberculosis to become the causative agent of bubonic and pneumonic plague. We identified a homolog of the Salmonella enterica serovar Typhimurium lipoprotein (lpp) gene in Yersinia species and prepared lpp gene deletion mutants of Y. pseudotuberculosis YPIII, Y. pestis KIM/D27 (pigmentation locus minus), and Y. pestis CO92 with reduced virulence. Mice injected via the intraperitoneal route with 5 × 107 CFU of the Δlpp KIM/D27 mutant survived a month, even though this would have constituted a lethal dose for the parental KIM/D27 strain. Subsequently, these Δlpp KIM/D27-injected mice were solidly protected against an intranasally administered, highly virulent Y. pestis CO92 strain when it was given as five 50% lethal doses (LD50). In a parallel study with the pneumonic plague mouse model, after 72 h postinfection, the lungs of animals infected with wild-type (WT) Y. pestis CO92 and given a subinhibitory dose of levofloxacin had acute inflammation, edema, and masses of bacteria, while the lung tissue appeared essentially normal in mice inoculated with the Δlpp mutant of CO92 and given the same dose of levofloxacin. Importantly, while WT Y. pestis CO92 could be detected in the bloodstreams and spleens of infected mice at 72 h postinfection, the Δlpp mutant of CO92 could not be detected in those organs. Furthermore, the levels of cytokines/chemokines detected in the sera were significantly lower in animals infected with the Δlpp mutant than in those infected with WT CO92. Additionally, the Δlpp mutant was more rapidly killed by macrophages than was the WT CO92 strain. These data provided evidence that the Δlpp mutants of yersiniae were significantly attenuated and could be useful tools in the development of new vaccines.

Cyclopropane Fatty Acids are Important for Salmonella enterica serovar Typhimurium Virulence

2021 ◽  
Author(s):  
Joyce E. Karlinsey ◽  
Angela M. Fung ◽  
Norah Johnston ◽  
Howard Goldfine ◽  
Stephen J. Libby ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Salmonella Enterica ◽  
Membrane Lipids ◽  
Fatty Acid Content ◽  
Acid Stress ◽  
Oxidase Inhibitor ◽  
Cyclopropane Fatty Acid ◽  
Wild Type ◽  
Gene Encoding ◽  
Serovar Typhimurium

A variety of eubacteria, plants and protozoa can modify membrane lipids by cyclopropanation, which is reported to modulate membrane permeability and fluidity. The ability to cyclopropanate membrane lipids has been associated with resistance to oxidative stress in Mycobacterium tuberculosis , organic solvent stress in Escherichia coli , and acid stress in E. coli and Salmonella . In bacteria, the cfa gene encoding cyclopropane fatty acid (CFA) synthase is induced during the stationary phase of growth. In the present study we constructed a cfa mutant of Salmonella enterica serovar Typhimurium 14028s ( S . Typhimurium) and determined the contribution of CFA-modified lipids to stress resistance and virulence in mice. Cyclopropane fatty acid content was quantified in wild-type and cfa mutant S. Typhimurium. CFA levels in a cfa mutant were greatly reduced compared to wild-type, indicating that CFA synthase is the major enzyme responsible for cyclopropane modification of lipids in Salmonella . S . Typhimurium cfa mutants were more sensitive to extreme acid pH, the protonophore CCCP, and hydrogen peroxide, compared to wild-type. In addition, cfa mutants exhibited reduced viability in murine macrophages and could be rescued by addition of the NADPH phagocyte oxidase inhibitor diphenyleneiodonium (DPI) chloride. S . Typhimurium lacking cfa was also attenuated for virulence in mice. These observations indicate that CFA modification of lipids makes an important contribution to Salmonella virulence.

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