Antimicrobial resistance and virulence factor gene profiles of Enterococcus spp. isolates from wild Arctocephalus australis (South American fur seal) and Arctocephalus tropicalis (Subantarctic fur seal)

2015 ◽  
Vol 31 (12) ◽  
pp. 1935-1946 ◽  
Author(s):  
Naiara Aguiar Santestevan ◽  
Dejoara de Angelis Zvoboda ◽  
Janira Prichula ◽  
Rebeca Inhoque Pereira ◽  
Guilherme Raffo Wachholz ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Virulence Factor ◽  
South American ◽  
Factor Gene ◽  
Gene Profiles ◽  
Fur Seal ◽  
Enterococcus Spp ◽  
Virulence Factor Gene ◽  
Arctocephalus Tropicalis

scholarly journals Virulence Factor Gene Profiles of Escherichia coli Isolates from Clinically Healthy Pigs

2006 ◽  
Vol 72 (10) ◽  
pp. 6680-6686 ◽  
Author(s):  
Peter Schierack ◽  
Hartmut Steinrück ◽  
Sylvia Kleta ◽  
Wilfried Vahjen
Keyword(s):  
Escherichia Coli ◽  
Virulence Factor ◽  
Virulence Genes ◽  
Clinical Signs ◽  
Virulence Gene ◽  
Bacterial Populations ◽  
Factor Gene ◽  
E Coli ◽  
Gene Profiles ◽  
Virulence Factor Gene

ABSTRACT Nonpathogenic, intestinal Escherichia coli (commensal E. coli) supports the physiological intestinal balance of the host, whereas pathogenic E. coli with typical virulence factor gene profiles can cause severe outbreaks of diarrhea. In many reports, E. coli isolates from diarrheic animals were classified as putative pathogens. Here we describe a broad variety of virulence gene-positive E. coli isolates from swine with no clinical signs of intestinal disease. The isolation of E. coli from 34 pigs from the same population and the testing of 331 isolates for genes encoding heat-stable enterotoxins I and II, heat-labile enterotoxin I, Shiga toxin 2e, and F4, F5, F6, F18, and F41 fimbriae revealed that 68.6% of the isolates were positive for at least one virulence gene, with a total of 24 different virulence factor gene profiles, implying high rates of horizontal gene transfer in this E. coli population. Additionally, we traced the occurrence of hemolytic E. coli over a period of 1 year in this same pig population. Hemolytic isolates were differentiated into seven clones; only three were found to harbor virulence genes. Hemolytic E. coli isolates without virulence genes or with only the fedA gene were found to be nontypeable by slide agglutination tests with OK antisera intended for screening live cultures against common pathogenic E. coli serogroups. The results appear to indicate that virulence gene-carrying E. coli strains are a normal part of intestinal bacterial populations and that high numbers of E. coli cells harboring virulence genes and/or with hemolytic activity do not necessarily correlate with disease.

Effect of curcumin on growth, biofilm formation and virulence factor gene expression of Porphyromonas gingivalis

Odontology ◽  
2020 ◽  
Vol 109 (1) ◽  
pp. 18-28
Author(s):  
Vijay M. Kumbar ◽  
Malleswara Rao Peram ◽  
Manohar S. Kugaji ◽  
Tejas Shah ◽  
Sanjivani P. Patil ◽  
...  
Keyword(s):  
Gene Expression ◽  
Porphyromonas Gingivalis ◽  
Virulence Factor ◽  
Biofilm Formation ◽  
Factor Gene ◽  
Virulence Factor Gene

scholarly journals A family of genus-specific RNAs in tandem with DNA-binding proteins control expression of thebadAmajor virulence factor gene inBartonella henselae

2016 ◽  
Vol 6 (2) ◽  
pp. e00420 ◽  
Author(s):  
Nhan Tu ◽  
Ronan K. Carroll ◽  
Andy Weiss ◽  
Lindsey N. Shaw ◽  
Gael Nicolas ◽  
...  
Keyword(s):  
Dna Binding ◽  
Virulence Factor ◽  
Binding Proteins ◽  
Dna Binding Proteins ◽  
Factor Gene ◽  
Virulence Factor Gene

Polymorphism and regulation of the spxB (pyruvate oxidase) virulence factor gene by a CBS-HotDog domain protein (SpxR) in serotype 2 Streptococcus pneumoniae

2007 ◽  
Vol 67 (4) ◽  
pp. 729-746 ◽  
Author(s):  
Smirla Ramos-Montañez ◽  
Ho-Ching Tiffany Tsui ◽  
Kyle J. Wayne ◽  
Jordan L. Morris ◽  
Lindsey E. Peters ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Virulence Factor ◽  
Pyruvate Oxidase ◽  
Factor Gene ◽  
Virulence Factor Gene ◽  
Domain Protein

scholarly journals Control ofStaphylococcus aureusQuorum Sensing by a Membrane-Embedded Peptidase

2019 ◽  
Vol 87 (5) ◽  
Author(s):  
Chance J. Cosgriff ◽  
Chelsea R. White ◽  
Wei Ping Teoh ◽  
James P. Grayczyk ◽  
Francis Alonzo
Keyword(s):  
Gene Expression ◽  
Virulence Factors ◽  
Virulence Factor ◽  
Inflammatory Responses ◽  
Infection Model ◽  
Active Site Residues ◽  
Accessory Gene ◽  
Content Type ◽  
Factor Gene ◽  
Virulence Factor Gene

ABSTRACTGram-positive bacteria process and release small peptides, or pheromones, that act as signals for the induction of adaptive traits, including those involved in pathogenesis. One class of small signaling pheromones is the cyclic autoinducing peptides (AIPs), which regulate expression of genes that orchestrate virulence and persistence in a range of microbes, including staphylococci, listeriae, clostridia, and enterococci. In a genetic screen forStaphylococcus aureussecreted virulence factors, we identified anS. aureusmutant containing an insertion in the geneSAUSA300_1984(mroQ), which encodes a putative membrane-embedded metalloprotease. A ΔmroQmutant exhibited impaired induction of Toll-like receptor 2-dependent inflammatory responses from macrophages but elicited greater production of the inflammatory cytokine interleukin-1β and was attenuated in a murine skin and soft tissue infection model. The ΔmroQmutant phenocopies anS. aureusmutant containing a deletion of the accessory gene regulatory system (Agr), wherein both strains have significantly reduced production of secreted toxins and virulence factors but increased surface protein A abundance. The Agr system controls virulence factor gene expression inS. aureusby sensing the accumulation of AIP via the histidine kinase AgrC and the response regulator AgrA. We provide evidence to suggest that MroQ acts within the Agr pathway to facilitate the optimal processing or export of AIP for signal amplification through AgrC/A and induction of virulence factor gene expression. Mutation of MroQ active-site residues significantly reduces AIP signaling and attenuates virulence. Altogether, this work identifies a new component of the Agr quorum-sensing circuit that is critical for the production ofS. aureusvirulence factors.

scholarly journals PlcR is a pleiotropic regulator of extracellular virulence factor gene expression in Bacillus thuringiensis

1999 ◽  
Vol 32 (5) ◽  
pp. 1043-1053 ◽  
Author(s):  
Herve Agaisse ◽  
Myriam Gominet ◽  
Ole Andreas Okstad ◽  
Anne-Brit Kolsto ◽  
Didier Lereclus
Keyword(s):  
Gene Expression ◽  
Bacillus Thuringiensis ◽  
Virulence Factor ◽  
Factor Gene ◽  
Virulence Factor Gene ◽  
Pleiotropic Regulator

scholarly journals Control of Staphylococcus aureus quorum sensing by a membrane-embedded peptidase

2019 ◽  
Author(s):  
Chance J. Cosgriff ◽  
Chelsea R. White ◽  
Wei Ping Teoh ◽  
James P. Grayczyk ◽  
Francis Alonzo
Keyword(s):  
Gene Expression ◽  
Staphylococcus Aureus ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Virulence Factor ◽  
Inflammatory Responses ◽  
Infection Model ◽  
Accessory Gene ◽  
Factor Gene ◽  
Virulence Factor Gene

AbstractGram-positive bacteria process and release small peptides or “pheromones” that act as signals for the induction of adaptive traits including those involved in pathogenesis. One class of small signaling pheromones is the cyclic auto-inducing peptides (AIPs), which regulate expression of genes that orchestrate virulence and persistence in a range of microbes including Staphylococci, Listeria, Clostridia, and Enterococci. In a genetic screen for Staphylococcus aureus secreted virulence factors, we identified a S. aureus mutant containing an insertion in gene SAUSA300_1984 (mroQ), which encodes a putative membrane-embedded metalloprotease. A ΔmroQ mutant exhibits impaired induction of TLR2-dependent inflammatory responses from macrophages, but elicits greater production of the inflammatory cytokine IL-1β and is attenuated in a murine skin and soft tissue infection model. The ΔmroQ mutant phenocopies a S. aureus mutant containing a deletion of the accessory gene regulatory system (Agr), wherein both strains have significantly reduced production of secreted toxins and virulence factors, but increased surface Protein A abundance. The Agr system controls virulence factor gene expression in S. aureus through sensing accumulation of AIP via the histidine kinase AgrC and response regulator AgrA. We provide evidence to suggest that MroQ acts within the Agr pathway to facilitate optimal processing or export of AIP for signal amplification through AgrC/A and induction of virulence factor gene expression. Mutation of MroQ active site residues significantly reduces AIP signaling and attenuates virulence. Altogether, this work identifies a new component of the Agr quorum sensing circuit that is critical for the production of S. aureus virulence factors.

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