scholarly journals Yersinia pseudotuberculosis doxycycline tolerance strategies include modulating expression of genes involved in cell permeability and tRNA modifications

2021 ◽  
Author(s):  
Hector S Alvarez-Manzo ◽  
Robert K Davidson ◽  
Jasper Van Cauwelaert de Wyels ◽  
Katherine L Cotten ◽  
Benjamin Nguyen ◽  
...  
Keyword(s):  
Yersinia Pseudotuberculosis ◽  
Cell Permeability ◽  
Phenotypic Change ◽  
Bacterial Survival ◽  
Translational Machinery ◽  
Doxycycline Treatment ◽  
Expression Of Genes ◽  
Relevant Dose ◽  
A Minor ◽  
Mouse Model Of Infection

Antibiotic tolerance is typically associated with a phenotypic change within a bacterial population, resulting in a transient decrease in antibiotic susceptibility that can contribute to treatment failure and recurrent infections. Although tolerant cells may emerge prior to treatment, the stress of prolonged antibiotic exposure can also promote tolerance. Here, we sought to determine how Yersinia pseudotuberculosis responds to doxycycline exposure, to then verify if these gene expression changes could promote doxycycline tolerance in culture and in our mouse model of infection. Only four genes were differentially regulated in response to a physiologically-relevant dose of doxycycline: osmB and ompF were upregulated, tusB and cnfy were downregulated; differential expression also occurred during doxycycline treatment in the mouse. ompF, tusB and cnfy were also differentially regulated in response to chloramphenicol, indicating these could be general responses to ribosomal inhibition. cnfy has previously been associated with persistence and was not a major focus here. We found deletion of the OmpF porin resulted in increased antibiotic accumulation, suggesting expression may promote diffusion of doxycycline out of the cell, while OsmB lipoprotein had a minor impact on antibiotic permeability. Overexpression of tusB significantly impaired bacterial survival in culture and in the mouse, suggesting that tRNA modification by TusB, and the resulting impacts on translational machinery, may play an important role in promoting tolerance. We believe this is the first observation of bactericidal activity of doxycycline, which was revealed by reversing tusB downregulation. 

Detection and Isolation of Yersinia pestis Without Fraction 1 Antigen by Monoclonal Antibody in Foods and Water

2012 ◽  
Vol 75 (9) ◽  
pp. 1555-1561 ◽  
Author(s):  
TONG ZHAO ◽  
PING ZHAO ◽  
MICHAEL P. DOYLE
Keyword(s):  
Monoclonal Antibody ◽  
Yersinia Pestis ◽  
Magnetic Beads ◽  
Yersinia Pseudotuberculosis ◽  
Brain Heart Infusion ◽  
Enteric Bacteria ◽  
Immunoblot Analysis ◽  
Enzyme Linked Immunosorbent Assay ◽  
Whole Cells ◽  
A Minor

Most available immunoassays for Yersinia pestis are based on the detection of fraction 1 antigen (F1) when yersiniae are grown at 37°C. A monoclonal antibody (MAb) was developed based on the detection of surface antigens that are not F1. F1-deficient Y. pestis cells were induced and used to immunize BALB/c mice from which MAb (immunoglobulin G1), which specifically recognizes Y. pestis, with or without F1, was obtained. This MAb (6B5) did not cross-react with enteric bacteria, including Yersinia enterocolitica. Enzyme-linked immunosorbent assay results revealed that MAb 6B5 is specific for Y. pestis, with the exception of a minor cross-reaction with Yersinia pseudotuberculosis. Western immunoblot analysis revealed that MAb 6B5 recognizes a Y. pestis outer membrane protein of ca. 30 kDa. Magnetic beads that were coated with MAb 6B5 were compared with beads coated with polyclonal antibody (PAb; rabbit) against Y. pestis for the isolation of Y. pestis in food and water samples by using a PATHATRIX cell concentration apparatus. Enrichment cultures of Y. pestis in different foods by using two different times (6 and 24 h) in brain heart infusion broth at 37°C were evaluated. Results revealed MAb 6B5–coated magnetic beads were equivalent to magnetic beads coated with PAb against Y. pestis A1122 whole cells in concentrating Y. pestis for isolation, especially when samples were enriched for 6 h. However, the selectivity for Y. pestis of the magnetic beads coated with MAb 6B5 was greater than that coated with PAb.

scholarly journals Superantigen YPMa Exacerbates the Virulence ofYersinia pseudotuberculosis in Mice

2000 ◽  
Vol 68 (5) ◽  
pp. 2553-2559 ◽  
Author(s):  
Christophe Carnoy ◽  
Chantal Mullet ◽  
Heide Müller-Alouf ◽  
Emmanuelle Leteurtre ◽  
Michel Simonet
Keyword(s):  
Yersinia Pseudotuberculosis ◽  
Systemic Infection ◽  
Peyer's Patches ◽  
Peyer’S Patches ◽  
Wild Type ◽  
Bacterial Inoculation ◽  
Mesenteric Lymph Nodes ◽  
Strain Determination ◽  
Mouse Model Of Infection

ABSTRACT Yersinia pseudotuberculosis, a gram-negative bacterium responsible for enteric and systemic infection in humans, produces a superantigenic toxin designated YPMa (Y. pseudotuberculosis-derived mitogen). To assess the role of YPMa in the pathogenesis of Y. pseudotuberculosis, we constructed a superantigen-deficient mutant and compared its virulence in a mouse model of infection to the virulence of the wild-type strain. Determination of the survival rate after intravenous (i.v.) bacterial inoculation of OF1 mice clearly showed that inactivation ofypmA, encoding YPMa, reduced the virulence of Y. pseudotuberculosis. Mice infected i.v. with 104 and 105 wild-type bacteria died within 9 days, whereas mice infected with the ypmA mutant survived 12 and 3 days longer, respectively. This decreased virulence of the ypmAmutant strain was not due to an impaired colonization of the spleen, liver, or lungs. In contrast to i.v. challenge, bacterial inoculation by the intragastric (i.g.) route did not reveal any difference in virulence between wild-type Y. pseudotuberculosis and theypmA mutant since the 50% lethal doses were identical for both strains. Moreover, inactivation of ypmA gene did not affect the bacterial growth of Y. pseudotuberculosis in Peyer's patches, mesenteric lymph nodes (MLNs), and spleen after oral infection. Histological studies of spleen, liver, lungs, heart, Peyer's patches, and MLNs after i.v. or i.g. challenge with the wild type or the ypmA mutant did not reveal any feature that can be specifically related to YPMa. Our data show that the superantigenic toxin YPMa contributes to the virulence of Y. pseudotuberculosis in systemic infection in mice.

scholarly journals The smpB-ssrA Mutant of Yersinia pestis Functions as a Live Attenuated Vaccine To Protect Mice against Pulmonary Plague Infection

2010 ◽  
Vol 78 (3) ◽  
pp. 1284-1293 ◽  
Author(s):  
Nihal A. Okan ◽  
Patricio Mena ◽  
Jorge L. Benach ◽  
James B. Bliska ◽  
A. Wali Karzai
Keyword(s):  
Yersinia Pestis ◽  
Type Iii Secretion ◽  
Control Mechanism ◽  
Live Attenuated Vaccine ◽  
Present Evidence ◽  
Translational Machinery ◽  
Full Capacity ◽  
Quality Control Mechanism ◽  
Mouse Model Of Infection ◽  
Related Proteins

ABSTRACT The bacterial SmpB-SsrA system is a highly conserved translational quality control mechanism that helps maintain the translational machinery at full capacity. Here we present evidence to demonstrate that the smpB-ssrA genes are required for pathogenesis of Yersinia pestis, the causative agent of plague. We found that disruption of the smpB-ssrA genes leads to reduction in secretion of the type III secretion-related proteins YopB, YopD, and LcrV, which are essential for virulence. Consistent with these observations, the smpB-ssrA mutant of Y. pestis was severely attenuated in a mouse model of infection via both the intranasal and intravenous routes. Most significantly, intranasal vaccination of mice with the smpB-ssrA mutant strain of Y. pestis induced a strong antibody response. The vaccinated animals were well protected against subsequent lethal intranasal challenges with virulent Y. pestis. Taken together, our results indicate that the smpB-ssrA mutant of Y. pestis possesses the desired qualities for a live attenuated cell-based vaccine against pneumonic plague.

scholarly journals Hnf1α (MODY3) Controls Tissue-Specific Transcriptional Programs and Exerts Opposed Effects on Cell Growth in Pancreatic Islets and Liver

2009 ◽  
Vol 29 (11) ◽  
pp. 2945-2959 ◽  
Author(s):  
Joan-Marc Servitja ◽  
Miguel Pignatelli ◽  
Miguel Ángel Maestro ◽  
Carina Cardalda ◽  
Sylvia F. Boj ◽  
...  
Keyword(s):  
Pancreatic Islets ◽  
Target Genes ◽  
Functional Dependence ◽  
T Antigen ◽  
Monogenic Diabetes ◽  
Tissue Specific ◽  
Cell Dysfunction ◽  
Expression Of Genes ◽  
Expression Studies ◽  
A Minor

ABSTRACT Heterozygous HNF1A mutations cause pancreatic-islet β-cell dysfunction and monogenic diabetes (MODY3). Hnf1α is known to regulate numerous hepatic genes, yet knowledge of its function in pancreatic islets is more limited. We now show that Hnf1a deficiency in mice leads to highly tissue-specific changes in the expression of genes involved in key functions of both islets and liver. To gain insights into the mechanisms of tissue-specific Hnf1α regulation, we integrated expression studies of Hnf1a-deficient mice with identification of direct Hnf1α targets. We demonstrate that Hnf1α can bind in a tissue-selective manner to genes that are expressed only in liver or islets. We also show that Hnf1α is essential only for the transcription of a minor fraction of its direct-target genes. Even among genes that were expressed in both liver and islets, the subset of targets showing functional dependence on Hnf1α was highly tissue specific. This was partly explained by the compensatory occupancy by the paralog Hnf1β at selected genes in Hnf1a-deficient liver. In keeping with these findings, the biological consequences of Hnf1a deficiency were markedly different in islets and liver. Notably, Hnf1a deficiency led to impaired large-T-antigen-induced growth and oncogenesis in β cells yet enhanced proliferation in hepatocytes. Collectively, these findings show that Hnf1α governs broad, highly tissue-specific genetic programs in pancreatic islets and liver and reveal key consequences of Hnf1a deficiency relevant to the pathophysiology of monogenic diabetes.

scholarly journals Iron-Sulfur Cluster Repair Contributes to Yersinia pseudotuberculosis Survival within Deep Tissues

2019 ◽  
Vol 87 (10) ◽  
Author(s):  
Kimberly M. Davis ◽  
Joanna Krupp ◽  
Stacie Clark ◽  
Ralph R. Isberg
Keyword(s):  
Yersinia Pseudotuberculosis ◽  
Nitrosative Stress ◽  
Bacterial Survival ◽  
Wild Type ◽  
Iron Sulfur Cluster ◽  
Content Type ◽  
Iron Sulfur ◽  
Repair Protein ◽  
Peripheral Cells ◽  
Host Tissues

ABSTRACT To successfully colonize host tissues, bacteria must respond to and detoxify many different host-derived antimicrobial compounds, such as nitric oxide (NO). NO has direct antimicrobial activity through attack on iron-sulfur (Fe-S) cluster-containing proteins. NO detoxification plays an important role in promoting bacterial survival, but it remains unclear if repair of Fe-S clusters is also important for bacterial survival within host tissues. Here we show that the Fe-S cluster repair protein YtfE contributes to the survival of Yersinia pseudotuberculosis within the spleen following nitrosative stress. Y. pseudotuberculosis forms clustered centers of replicating bacteria within deep tissues, where peripheral bacteria express the NO-detoxifying gene hmp. ytfE expression also occurred specifically within peripheral cells at the edges of microcolonies. In the absence of ytfE, the area of microcolonies was significantly smaller than that of the wild type (WT), consistent with ytfE contributing to the survival of peripheral cells. The loss of ytfE did not alter the ability of cells to detoxify NO, which occurred within peripheral cells in both WT and ΔytfE microcolonies. In the absence of NO-detoxifying activity by hmp, NO diffused across ΔytfE microcolonies, and there was a significant decrease in the area of microcolonies lacking ytfE, indicating that ytfE also contributes to bacterial survival in the absence of NO detoxification. These results indicate a role for Fe-S cluster repair in the survival of Y. pseudotuberculosis within the spleen and suggest that extracellular bacteria may rely on this pathway for survival within host tissues.

scholarly journals Brassinazole Resistant 1 Activity Is Organ-Specific and Genotype-Dependent in Barley Seedlings

2021 ◽  
Vol 22 (24) ◽  
pp. 13572
Author(s):  
Jolanta Groszyk ◽  
Magdalena Szechyńska-Hebda
Keyword(s):  
Signaling Pathways ◽  
Minor Amount ◽  
Golden Promise ◽  
Gene Expressions ◽  
Crop Species ◽  
Molecular Weights ◽  
Expression Of Genes ◽  
Organ Specific ◽  
Seminal Roots ◽  
A Minor

Brassinosteroids (BRs) control many plant developmental processes by regulating different groups of transcription factors, and consequently gene expressions. The most known is BZR1, the main member of the BES1 family. However, to date, it is poorly characterized in crop species. The main goal of the presented study was to identify HvBZR1 and determine its activity in 5-day-old barley (the stage is related to one leaf on the main shoot and a few seminal roots) using two cultivars with different sensitivities to BRs. Using the anti-OsBZR1 antibody, we identified the forms of HvBZR1 transcription factor with different molecular weights, which can be related to different phosphorylated forms of serine/threonine residues. Two phosphorylated forms in the shoots and one dephosphorylated form in the roots were determined. A minor amount of the dephosphorylated form of the HvBZR1 in the Haruna Nijo shoots was also found. The phosphorylated forms gave a higher band intensity for Golden Promise than Haruna Nijo. The bands were similar in their intensity, when two different phosphorylated forms were compared in Golden Promise, while a reduced intensity was detected for the phosphorylated form with a lower molecular weight for Haruna Nijo. Degradation of the phosphorylated forms in the shoots (complete degradation in Golden Promise and significant but not complete in Haruna Nijo) and the presence of the dephosphorylated form in the roots were proven for the etiolated barley. In the case of Haruna Nijo, a wider range of the regulators of the BR biosynthesis and signaling pathways induced the expected effects, 24-EBL (0.001 µM) and bikinin (10 and 50 µM) caused low amount of the phosphorylated forms, and at the same time, a tiny band of dephosphorylated form was detected. However, the expression of genes related to the BR biosynthesis and signaling pathways was not a determinant for the protein amount.

scholarly journals More Evidence of Collusion: a New Prophage-Mediated Viral Defense System Encoded by Mycobacteriophage Sbash

mBio ◽  
2019 ◽  
Vol 10 (2) ◽  
Author(s):  
Gabrielle M. Gentile ◽  
Katherine S. Wetzel ◽  
Rebekah M. Dedrick ◽  
Matthew T. Montgomery ◽  
Rebecca A. Garlena ◽  
...  
Keyword(s):  
Microbial Evolution ◽  
Bacterial Survival ◽  
Defense System ◽  
Microbial World ◽  
Content Type ◽  
Strong Selection ◽  
Defense Systems ◽  
Expression Of Genes ◽  
Bacterial Chromosomes ◽  
Selection For

ABSTRACTThe arms race between bacteria and their bacteriophages profoundly influences microbial evolution. With an estimated 1023phage infections occurring per second, there is strong selection for both bacterial survival and phage coevolution for continued propagation. Many phage resistance systems, including restriction-modification systems, clustered regularly interspaced short palindromic repeat-Cas (CRISPR-Cas) systems, a variety of abortive infection systems, and many others that are not yet mechanistically defined, have been described. Temperate bacteriophages are common and form stable lysogens that are immune to superinfection by the same or closely related phages. However, temperate phages collude with their hosts to confer defense against genomically distinct phages, to the mutual benefit of the bacterial host and the prophage. Prophage-mediated viral systems have been described inMycobacteriumphages andPseudomonasphages but are predicted to be widespread throughout the microbial world. Here we describe a new viral defense system in which the mycobacteriophage Sbash prophage colludes with itsMycobacterium smegmatishost to confer highly specific defense against infection by the unrelated mycobacteriophage Crossroads. Sbash genes30and31are lysogenically expressed and are necessary and sufficient to confer defense against Crossroads but do not defend against any of the closely related phages grouped in subcluster L2. The mapping of Crossroads defense escape mutants shows that genes132and141are involved in recognition by the Sbash defense system and are proposed to activate a loss in membrane potential mediated by Sbash gp30 and gp31.IMPORTANCEViral infection is an ongoing challenge to bacterial survival, and there is strong selection for development or acquisition of defense systems that promote survival when bacteria are attacked by bacteriophages. Temperate phages play central roles in these dynamics through lysogenic expression of genes that defend against phage attack, including those unrelated to the prophage. Few prophage-mediated viral defense systems have been characterized, but they are likely widespread both in phage genomes and in the prophages integrated in bacterial chromosomes.

scholarly journals YshB Promotes Intracellular Replication and Is Required for Salmonella Virulence

2019 ◽  
Vol 201 (17) ◽  
Author(s):  
Rajdeep Bomjan ◽  
Mei Zhang ◽  
Daoguo Zhou
Keyword(s):  
Small Rnas ◽  
Intracellular Survival ◽  
The Body ◽  
Host Cells ◽  
Bacterial Survival ◽  
Body Of Knowledge ◽  
Common Causes ◽  
Salmonella Virulence ◽  
Mouse Model Of Infection

ABSTRACT Salmonella virulence requires the initial invasion of host cells, followed by modulation of the intracellular environment for survival and replication. In an effort to characterize the role of small RNAs in Salmonella pathogenesis, we inadvertently identified a 5-kDa protein named YshB that is involved in the intracellular survival of Salmonella. We show here that yshB expression is upregulated upon entry into macrophages. When yshB expression is upregulated before bacterial entry, invasion efficiency is inhibited. Lack of YshB resulted in reduced bacterial survival within the macrophages and led to reduced virulence in a mouse model of infection. IMPORTANCE Salmonella gastroenteritis is one of the most common causes of foodborne disease, possibly affecting millions of people globally each year. Here we characterize the role of a novel small protein, YshB, in mediating Salmonella intracellular survival. This elucidation adds to the body of knowledge regarding how this bacterium achieves intracellular survival.

scholarly journals Influence of the Cpx Extracytoplasmic-Stress-Responsive Pathway on Yersinia sp.-Eukaryotic Cell Contact

2007 ◽  
Vol 75 (9) ◽  
pp. 4386-4399 ◽  
Author(s):  
Katrin E. Carlsson ◽  
Junfa Liu ◽  
Petra J. Edqvist ◽  
Matthew S. Francis
Keyword(s):  
Yersinia Pseudotuberculosis ◽  
Response Regulator ◽  
Extreme Environments ◽  
Signal Transduction Pathway ◽  
Eukaryotic Cell ◽  
Eukaryotic Cells ◽  
Cell Contact ◽  
Virulence Determinants ◽  
Negative Effects ◽  
Expression Of Genes

ABSTRACT The extracytoplasmic-stress-responsive CpxRA two-component signal transduction pathway allows bacteria to adapt to growth in extreme environments. It controls the production of periplasmic protein folding and degradation factors, which aids in the biogenesis of multicomponent virulence determinants that span the bacterial envelope. This is true of the Yersinia pseudotuberculosis Ysc-Yop type III secretion system. However, despite using a second-site suppressor mutation to restore Yop effector secretion by yersiniae defective in the CpxA sensor kinase, these bacteria poorly translocated Yops into target eukaryotic cells. Investigation of this phenotype herein revealed that the expression of genes which encode several surface-located adhesins is also influenced by the Cpx pathway. In particular, the expression and surface localization of invasin, an adhesin that engages β1-integrins on the eukaryotic cell surface, are severely restricted by the removal of CpxA. This reduces bacterial association with eukaryotic cells, which could be suppressed by the ectopic production of CpxA, invasin, or RovA, a positive activator of inv expression. In turn, these infected eukaryotic cells then became susceptible to intoxication by translocated Yop effectors. In contrast, bacteria harboring an in-frame deletion of cpxR, which encodes the cognate response regulator, displayed an enhanced ability to interact with cell monolayers, as well as elevated inv and rovA transcription. This phenotype could be drastically suppressed by providing a wild-type copy of cpxR in trans. We propose a mechanism of inv regulation influenced by the direct negative effects of phosphorylated CpxR on inv and rovA transcription. In this fashion, sensing of extracytoplasmic stress by CpxAR contributes to productive Yersinia sp.-eukaryotic cell interactions.

scholarly journals Point Mutations in a Peptidoglycan Biosynthesis Gene Cause Competence Induction in Haemophilus influenzae

2000 ◽  
Vol 182 (12) ◽  
pp. 3323-3330 ◽  
Author(s):  
Caixia Ma ◽  
Rosemary J. Redfield
Keyword(s):  
Haemophilus Influenzae ◽  
Signal Sequence ◽  
Point Mutations ◽  
Cell Permeability ◽  
Dna Uptake ◽  
Peptidoglycan Biosynthesis ◽  
Peptidoglycan Synthesis ◽  
Expression Of Genes ◽  
Conserved Residue ◽  
Competence Induction

ABSTRACT We have identified three new Haemophilus influenzaemutations causing cells to exhibit extreme hypercompetence at all stages of growth. The mutations are in murE, which encodes the meso-diaminopimelate-adding enzyme of peptidoglycan synthesis. All are point mutations causing nonconservative amino acid substitutions, two at a poorly conserved residue (G435→R and G435→W) and the third at a highly conserved leucine (L361→S). The mutant strains have very similar phenotypes and do not exhibit any defects in cell growth, permeability, or sensitivity to peptidoglycan antibiotics. Cells retain the normal specificity of DNA uptake for the H. influenzae uptake signal sequence. The mutations do not bypass genes known to be needed for competence induction but do dramatically increase expression of genes required for the normal pathway of DNA uptake. We conclude that the mutations do not act by increasing cell permeability but by causing induction of the normal competence pathway via a previously unsuspected signal.

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