scholarly journals Reciprocal regulation of Yersinia pestis biofilm formation and virulence by RovM and RovA

Open Biology ◽  
2016 ◽  
Vol 6 (3) ◽  
pp. 150198 ◽  
Author(s):  
Lei Liu ◽  
Haihong Fang ◽  
Huiying Yang ◽  
Yiquan Zhang ◽  
Yanping Han ◽  
...  
Keyword(s):  
Gene Expression ◽  
Yersinia Pestis ◽  
Biofilm Formation ◽  
Virulence Gene ◽  
Reciprocal Regulation ◽  
Virulence Gene Expression ◽  
Biofilm Production ◽  
Gene Regulatory ◽  
Virulence Factor Production ◽  
Transmissible Infection

RovA is known to enhance Yersinia pestis virulence by directly upregulating the psa loci. This work presents a complex gene regulatory paradigm involving the reciprocal regulatory action of RovM and RovA on the expression of biofilm and virulence genes as well as on their own genes. RovM and RovA enhance and inhibit Y. pestis biofilm production, respectively, whereas RovM represses virulence in mice. RovM directly stimulates the transcription of hmsT , hmsCDE and rovM , while indirectly enhancing hmsHFRS transcription. It also indirectly represses hmsP transcription. By contrast, RovA directly represses hmsT transcription and indirectly inhibits waaAE-coaD transcription, while RovM inhibits psaABC and psaEF transcription by directly repressing rovA transcription. rovM expression is significantly upregulated at 26°C (the temperature of the flea gut) relative to 37°C (the warm-blooded host temperature). We speculate that upregulation of rovM together with downregulation of rovA in the flea gut would promote Y. pestis biofilm formation while inhibiting virulence gene expression, leading to a more transmissible infection of this pathogen in fleas. Once the bacterium shifts to a lifestyle in the warm-blooded hosts, inhibited RovM production accompanied by recovered RovA synthesis would encourage virulence factor production and inhibit biofilm gene expression.

scholarly journals Association among biofilm formation, virulence gene expression, and antibiotic resistance in Proteus mirabilis isolates from diarrhetic animals in northeast China

2020 ◽  
Author(s):  
Yadong Sun ◽  
Shanshan Wen ◽  
Lili Zhao ◽  
Qiqi Xia ◽  
Yue Pan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Antibiotic Resistance ◽  
Biofilm Formation ◽  
Northeast China ◽  
Virulence Gene ◽  
Drug Susceptibility ◽  
Multidrug Resistant ◽  
Virulence Gene Expression ◽  
Biofilm Production ◽  
High Level

Abstract Background The aim of this study was to investigate the association among biofilm formation, virulence gene expression, and antibiotic resistance in P. mirabilis isolates collected from diarrhetic animals (n = 176) in northeast China between September 2014 and October 2016. Results Approximately 92.05% of the isolates were biofilm producers, whereas 7.95% of the isolates were non-producers. The prevalence of virulence genes in biofilm producers was significantly higher than that in non-producers. Biofilm production was significantly associated with the expression of ureC , zapA , rsmA , hmpA , mrpA , atfA , and pmfA ( P < 0.05). Drug susceptibility tests revealed that approximately 76.7% of the isolates were multidrug-resistant (MDR) and extensively drug-resistant (XDR). Biofilm production was significantly associated with resistance to doxycycline, tetracycline, sulfamethoxazole, kanamycin, and cephalothin ( P < 0.05). Although the pathogenicity of the biofilm producers was stronger than that of the non-producers, the biofilm-forming ability of the isolates was not significantly associated with morbidity and mortality in mice ( P > 0.05). Conclusion Our findings suggested that a high level of multidrug resistance in diarrhetic animals infected with P. mirabilis in northeast China.The results of this study indicated that the positive rates of the genes expressed by biofilm-producing P. mirabilis isolates were significantly higher than those expressed by non-producing isolates.

scholarly journals Regulation of Rugosity and Biofilm Formation in Vibrio cholerae: Comparison of VpsT and VpsR Regulons and Epistasis Analysis of vpsT, vpsR, and hapR

2007 ◽  
Vol 189 (2) ◽  
pp. 388-402 ◽  
Author(s):  
Sinem Beyhan ◽  
Kivanc Bilecen ◽  
Sofie R. Salama ◽  
Catharina Casper-Lindley ◽  
Fitnat H. Yildiz
Keyword(s):  
Gene Expression ◽  
Vibrio Cholerae ◽  
Biofilm Formation ◽  
Virulence Gene ◽  
Virulence Gene Expression ◽  
Epistasis Analysis ◽  
Genome Expression ◽  
Ggdef Domain ◽  
Whole Genome Expression ◽  
Virulence Factor Production

ABSTRACT Vibrio cholerae undergoes phenotypic variation that generates two morphologically different variants, termed smooth and rugose. The transcriptional profiles of the two variants differ greatly, and many of the differentially regulated genes are controlled by a complex regulatory circuitry that includes the transcriptional regulators VpsR, VpsT, and HapR. In this study, we identified the VpsT regulon and compared the VpsT and VpsR regulons to elucidate the contribution of each positive regulator to the rugose variant transcriptional profile and associated phenotypes. We have found that although the VpsT and VpsR regulons are very similar, the magnitude of the gene regulation accomplished by each regulator is different. We also determined that cdgA, which encodes a GGDEF domain protein, is partially responsible for the altered vps gene expression between the vpsT and vpsR mutants. Analysis of epistatic relationships among hapR, vpsT, and vpsR with respect to a whole-genome expression profile, colony morphology, and biofilm formation revealed that vpsR is epistatic to hapR and vpsT. Expression of virulence genes was increased in a vpsR hapR double mutant relative to a hapR mutant, suggesting that VpsR negatively regulates virulence gene expression in the hapR mutant. These results show that a complex regulatory interplay among VpsT, VpsR, HapR, and GGDEF/EAL family proteins controls transcription of the genes required for Vibrio polysaccharide and virulence factor production in V. cholerae.

scholarly journals Association among biofilm formation, virulence gene expression, and antibiotic resistance in Proteus mirabilis isolates from diarrhetic animals in northeast China

2020 ◽  
Author(s):  
Yadong Sun ◽  
Shanshan Wen ◽  
Lili Zhao ◽  
Qiqi Xia ◽  
Yue Pan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Antibiotic Resistance ◽  
Biofilm Formation ◽  
Northeast China ◽  
Virulence Gene ◽  
Drug Susceptibility ◽  
Multidrug Resistant ◽  
Virulence Gene Expression ◽  
Biofilm Production ◽  
High Level

Abstract Background The aim of this study was to investigate the association among biofilm formation, virulence gene expression, and antibiotic resistance in P. mirabilis isolates collected from diarrhetic animals (n = 176) in northeast China between September 2014 and October 2016. Results Approximately 92.05% of the isolates were biofilm producers, whereas 7.95% of the isolates were non-producers. The prevalence of virulence genes in biofilm producers was significantly higher than that in non-producers. Biofilm production was significantly associated with the expression of ureC , zapA , rsmA , hmpA , mrpA , atfA , and pmfA ( P < 0.05). Drug susceptibility tests revealed that approximately 76.7% of the isolates were multidrug-resistant (MDR) and extensively drug-resistant (XDR). Biofilm production was significantly associated with resistance to doxycycline, tetracycline, sulfamethoxazole, kanamycin, and cephalothin ( P < 0.05). Although the pathogenicity of the biofilm producers was stronger than that of the non-producers, the biofilm-forming ability of the isolates was not significantly associated with morbidity and mortality in mice ( P > 0.05). Conclusion Our findings suggested that a high level of multidrug resistance in diarrhetic animals infected with P. mirabilis in northeast China.The results of this study indicated that the positive rates of the genes expressed by biofilm-producing P. mirabilis isolates were significantly higher than those expressed by non-producing isolates.

scholarly journals Association among biofilm formation, virulence gene expression, and antibiotic resistance in Proteus mirabilis isolates from diarrhetic animals in northeast China

2019 ◽  
Author(s):  
Yadong Sun ◽  
Shanshan Wen ◽  
Lili Zhao ◽  
Qiqi Xia ◽  
Yue Pan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Antibiotic Resistance ◽  
Biofilm Formation ◽  
Northeast China ◽  
Virulence Gene ◽  
Drug Susceptibility ◽  
Multidrug Resistant ◽  
Virulence Gene Expression ◽  
Biofilm Production ◽  
High Level

Abstract Background The aim of this study was to investigate the association among biofilm formation, virulence gene expression, and antibiotic resistance in P. mirabilis isolates collected from diarrhetic animals (n = 176) in northeast China between September 2014 and October 2016. Results Approximately 92.05% of the isolates were biofilm producers, whereas 7.95% of the isolates were non-producers. The prevalence of virulence genes in biofilm producers was significantly higher than that in non-producers. Biofilm production was significantly associated with the expression of ureC , zapA , rsmA , hmpA , mrpA , atfA , and pmfA ( P < 0.05). Drug susceptibility tests revealed that approximately 76.7% of the isolates were multidrug-resistant (MDR) and extensively drug-resistant (XDR). Biofilm production was significantly associated with resistance to doxycycline, tetracycline, sulfamethoxazole, kanamycin, and cephalothin ( P < 0.05). Although the pathogenicity of the biofilm producers was stronger than that of the non-producers, the biofilm-forming ability of the isolates was not significantly associated with morbidity and mortality in mice ( P > 0.05). Conclusion Our findings suggested that a high level of multidrug resistance in diarrhetic animals infected with P. mirabilis in northeast China.The results of this study indicated that the positive rates of the genes expressed by biofilm-producing P. mirabilis isolates were significantly higher than those expressed by non-producing isolates.

scholarly journals Norlichexanthone Reduces Virulence Gene Expression and Biofilm Formation in Staphylococcus aureus

PLoS ONE ◽  
2016 ◽  
Vol 11 (12) ◽  
pp. e0168305 ◽  
Author(s):  
Mara Baldry ◽  
Anita Nielsen ◽  
Martin S. Bojer ◽  
Yu Zhao ◽  
Cathrine Friberg ◽  
...  
Keyword(s):  
Gene Expression ◽  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Virulence Gene ◽  
Virulence Gene Expression

scholarly journals Novel Inhibitors of Staphylococcus aureus Virulence Gene Expression and Biofilm Formation

PLoS ONE ◽  
2012 ◽  
Vol 7 (10) ◽  
pp. e47255 ◽  
Author(s):  
Yibao Ma ◽  
Yuanxi Xu ◽  
Bryan D. Yestrepsky ◽  
Roderick J. Sorenson ◽  
Meng Chen ◽  
...  
Keyword(s):  
Gene Expression ◽  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Virulence Gene ◽  
Virulence Gene Expression

scholarly journals Indole Inhibits ToxR Regulon Expression inVibrio cholerae

2019 ◽  
Vol 87 (3) ◽  
Author(s):  
Mondraya F. Howard ◽  
X. Renee Bina ◽  
James E. Bina
Keyword(s):  
Virulence Factor ◽  
Virulence Gene ◽  
Dependent Manner ◽  
Content Type ◽  
Virulence Gene Expression ◽  
Type Vi Secretion ◽  
Biofilm Production ◽  
Factor Production ◽  
Periplasmic Domain ◽  
Virulence Factor Production

ABSTRACTIndole is a degradation product of tryptophan that functions as a signaling molecule in many bacteria. This includesVibrio cholerae, where indole was shown to regulate biofilm and type VI secretion in nontoxigenic environmental isolates. Indole is also produced by toxigenicV. choleraestrains in the human intestine, but its significance in the host is unknown. We investigated the effects of indole on toxigenicV. choleraeO1 El Tor during growth under virulence inducing conditions. The indole transcriptome was defined by RNA sequencing and showed widespread changes in the expression of genes involved in metabolism, biofilm production, and virulence factor production. In contrast, genes involved in type VI secretion were not affected by indole. We subsequently found that indole repressed genes involved inV. choleraepathogenesis, including the ToxR virulence regulon. Consistent with this, indole inhibited cholera toxin and toxin-coregulated pilus production in a dose-dependent manner. The effects of indole on virulence factor production and biofilm were linked to ToxR and the ToxR-dependent regulator LeuO. The expression ofleuOwas increased by exogenous indole and linked to repression of the ToxR virulence regulon. This process was dependent on the ToxR periplasmic domain, suggesting that indole was a ToxR agonist. This conclusion was further supported by results showing that the ToxR periplasmic domain contributed to indole-mediated increased biofilm production. Collectively, our results suggest that indole may be a niche-specific cue that can function as a ToxR agonist to modulate virulence gene expression and biofilm production inV. cholerae.

scholarly journals Host stress hormone norepinephrine stimulates pneumococcal growth, biofilm formation and virulence gene expression

2014 ◽  
Vol 14 (1) ◽  
pp. 180 ◽  
Author(s):  
Sara Sandrini ◽  
Fayez Alghofaili ◽  
Primrose Freestone ◽  
Hasan Yesilkaya
Keyword(s):  
Gene Expression ◽  
Biofilm Formation ◽  
Virulence Gene ◽  
Stress Hormone ◽  
Virulence Gene Expression

Norfloxacin Sub-Inhibitory Concentration Affects Streptococcus suis Biofilm Formation and Virulence Gene Expression

2020 ◽  
Author(s):  
Baobao Li ◽  
Li Yi ◽  
Jinpeng Li ◽  
Shenglong Gong ◽  
Xiao Dong ◽  
...  
Keyword(s):  
Gene Expression ◽  
Biofilm Formation ◽  
Inhibitory Concentration ◽  
Mrna Level ◽  
Virulence Gene ◽  
Streptococcus Suis ◽  
Economic Losses ◽  
Swine Industry ◽  
Virulence Gene Expression ◽  
Viable Bacteria

Streptococcus suis (S. suis) is a major pathogen causing economic losses to the swine industry. Norfloxacins are usually used at sub-MIC (Minimum Inhibitory Concentration) doses to prevent S. suis infection. This study demonstrates the effect of norfloxacin sub-MIC on biofilm formation and virulence gene expression in S. suis.It was found that 1/4 MIC of norfloxacin increased biofilm formation in S. suis, the biofilms formed contained a higher number of viable bacteria. Additionally, bacterial growth rates were inhibited at 1/2 MIC of norfloxacin. Furthermore, the mRNA level of S. suis virulence gene cps, ef, sly, fpbs, gdh and gapdh increased by real-time PCR, while the virulence gene mrp decreased at 1/4 MIC. In conclusion, Norfloxacin sub-MICs affects biofilm formation and virulence gene expression in S. suis. These findings suggest that investigating the effect of the administration of antibiotics sub-MICs on bacterial biofilms and infection may lead to the development of future antibiotic treatments modalities.

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