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.

Vibrio harveyi virulence gene expression in vitro and in vivo during infection in black tiger shrimp Penaeus monodon

2020 ◽  
Vol 139 ◽  
pp. 153-160
Author(s):  
S Peeralil ◽  
TC Joseph ◽  
V Murugadas ◽  
PG Akhilnath ◽  
VN Sreejith ◽  
...  
Keyword(s):  
Gene Expression ◽  
Virulence Genes ◽  
Vibrio Harveyi ◽  
Penaeus Monodon ◽  
Challenge Test ◽  
Virulence Gene ◽  
Economic Losses ◽  
Virulence Gene Expression

Luminescent Vibrio harveyi is common in sea and estuarine waters. It produces several virulence factors and negatively affects larval penaeid shrimp in hatcheries, resulting in severe economic losses to shrimp aquaculture. Although V. harveyi is an important pathogen of shrimp, its pathogenicity mechanisms have yet to be completely elucidated. In the present study, isolates of V. harveyi were isolated and characterized from diseased Penaeus monodon postlarvae from hatcheries in Kerala, India, from September to December 2016. All 23 tested isolates were positive for lipase, phospholipase, caseinase, gelatinase and chitinase activity, and 3 of the isolates (MFB32, MFB71 and MFB68) showed potential for significant biofilm formation. Based on the presence of virulence genes, the isolates of V. harveyi were grouped into 6 genotypes, predominated by vhpA+ flaB+ ser+ vhh1- luxR+ vopD- vcrD+ vscN-. One isolate from each genotype was randomly selected for in vivo virulence experiments, and the LD50 ranged from 1.7 ± 0.5 × 103 to 4.1 ± 0.1 × 105 CFU ml-1. The expression of genes during the infection in postlarvae was high in 2 of the isolates (MFB12 and MFB32), consistent with the result of the challenge test. However, in MFB19, even though all genes tested were present, their expression level was very low and likely contributed to its lack of virulence. Because of the significant variation in gene expression, the presence of virulence genes alone cannot be used as a marker for pathogenicity of V. harveyi.

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 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 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 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

scholarly journals Carbohydrate Availability Regulates Virulence Gene Expression in Streptococcus suis

PLoS ONE ◽  
2014 ◽  
Vol 9 (3) ◽  
pp. e89334 ◽  
Author(s):  
M. Laura Ferrando ◽  
Peter van Baarlen ◽  
Germano Orrù ◽  
Rosaria Piga ◽  
Roger S. Bongers ◽  
...  
Keyword(s):  
Gene Expression ◽  
Virulence Gene ◽  
Streptococcus Suis ◽  
Virulence Gene Expression ◽  
Carbohydrate Availability

Motility, biofilm formation, apoptotic effect and virulence gene expression of atypical Salmonella Typhimurium outside and inside Caco-2 cells

2018 ◽  
Vol 114 ◽  
pp. 153-162 ◽  
Author(s):  
Ibtissem Chakroun ◽  
Abdelkarim Mahdhi ◽  
Patricia Morcillo ◽  
Hector Cordero ◽  
Alberto Cuesta ◽  
...  
Keyword(s):  
Gene Expression ◽  
Salmonella Typhimurium ◽  
Biofilm Formation ◽  
Virulence Gene ◽  
Virulence Gene Expression ◽  
Apoptotic Effect

scholarly journals The micronutrient zinc inhibits EAEC strain 042 adherence, biofilm formation, virulence gene expression, and epithelial cytokine responses benefiting the infected host

Virulence ◽  
2013 ◽  
Vol 4 (7) ◽  
pp. 624-633 ◽  
Author(s):  
Pedro Medeiros ◽  
David T Bolick ◽  
James K Roche ◽  
Francisco Noronha ◽  
Caio Pinheiro ◽  
...  
Keyword(s):  
Gene Expression ◽  
Biofilm Formation ◽  
Virulence Gene ◽  
Infected Host ◽  
Virulence Gene Expression ◽  
Eaec Strain ◽  
Cytokine Responses

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.

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