scholarly journals An Acylase from Shewanella Putrefaciens Presents a Vibrio Parahaemolyticus Acylhomoserine Lactone-Degrading Activity and Exhibits Temperature-, Ph- and Metal-Dependences

2020 ◽  
Vol 49 (4) ◽  
pp. 375-381
Author(s):  
Z. Fang ◽  
D. Sun ◽  
J. Gao ◽  
M. Guo ◽  
L. Sun ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Vibrio Parahaemolyticus ◽  
Shewanella Putrefaciens ◽  
Regulation Mechanism ◽  
Degrading Enzyme ◽  
Acylhomoserine Lactone

Shewanella putrefaciens supernatant was found to increase the virulence factors of Vibrio parahaemolyticus by efficiently degrading its acylhomoserine lactone (AHL). To further reveal the regulation mechanism and its key degrading enzyme, a potential AHL-degrading enzyme acylase (Aac) from S. putrefaciens was cloned, and the influences of temperature, pH, protein modifiers, and metals on Aac were tested. Aac was significantly influenced by temperature and pH, and exhibited the highest AHL-degrading activity at temperatures of 37 °C and pH of 8. Mg2+ and Fe2+ can further increase the AHL-degrading activity. 10 mM EDTA inhibited its activity possibly by chelating the co-factors (metals) required for Aac activity. Tryptophan and arginine were identified as key components for Aac activity that are critical to its AHL-degrading activity. This study provides useful information on Aac and for V. parahaemolyticus control.

scholarly journals Vibrio parahaemolyticus : Basic Techniques for Growth, Genetic Manipulation, and Analysis of Virulence Factors

2020 ◽  
Vol 59 (1) ◽  
Author(s):  
Suneeta Chimalapati ◽  
Alexander E. Lafrance ◽  
Luming Chen ◽  
Kim Orth
Keyword(s):  
Virulence Factors ◽  
Vibrio Parahaemolyticus ◽  
Genetic Manipulation

scholarly journals Contribution of Vibrio parahaemolyticus Virulence Factors to Cytotoxicity, Enterotoxicity, and Lethality in Mice

2010 ◽  
Vol 78 (4) ◽  
pp. 1772-1780 ◽  
Author(s):  
Hirotaka Hiyoshi ◽  
Toshio Kodama ◽  
Tetsuya Iida ◽  
Takeshi Honda
Keyword(s):  
Cell Lines ◽  
Virulence Factors ◽  
Vibrio Parahaemolyticus ◽  
Biological Activities ◽  
Infection Model ◽  
Cytotoxic Activities ◽  
Mutant Strains ◽  
Thermostable Direct Hemolysin ◽  
Clinical Illness ◽  
Pathogenic Vibrios

ABSTRACT Vibrio parahaemolyticus, one of the human-pathogenic vibrios, causes three major types of clinical illness: gastroenteritis, wound infections, and septicemia. Thermostable direct hemolysin (TDH) secreted by this bacterium has been considered a major virulence factor of gastroenteritis because it has biological activities, including cytotoxic and enterotoxic activities. Previous reports revealed that V. parahaemolyticus strain RIMD2210633, which contains tdh, has two sets of type III secretion system (T3SS) genes on chromosomes 1 and 2 (T3SS1 and T3SS2, respectively) and that T3SS1 is responsible for cytotoxicity and T3SS2 is involved in enterotoxicity, as well as in cytotoxic activity. However, the relative importance and contributions of TDH and the two T3SSs to V. parahaemolyticus pathogenicity are not well understood. In this study, we constructed mutant strains with nonfunctional T3SSs from the V. parahaemolyticus strain containing tdh, and then the pathogenicities of the wild-type and mutant strains were evaluated by assessing their cytotoxic activities against HeLa, Caco-2, and RAW 264 cells, their enterotoxic activities in rabbit ileal loops, and their lethality in a murine infection model. We demonstrated that T3SS1 was involved in cytotoxic activities against all cell lines used in this study, while T3SS2 and TDH had cytotoxic effects on a limited number of cell lines. T3SS2 was the major contributor to V. parahaemolyticus-induced enterotoxicity. Interestingly, we found that both T3SS1 and TDH played a significant role in lethal activity in a murine infection model. Our findings provide new indications that these virulence factors contribute to and orchestrate each distinct aspect of the pathogenicity of V. parahaemolyticus.

scholarly journals Attenuation of Multiple Vibrio parahaemolyticus Virulence Factors by Citral

2019 ◽  
Vol 10 ◽  
Author(s):  
Yi Sun ◽  
Du Guo ◽  
Zi Hua ◽  
Huihui Sun ◽  
Zhanwen Zheng ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Vibrio Parahaemolyticus

scholarly journals Interference with Pseudomonas aeruginosa Quorum Sensing and Virulence by the Mycobacterial Pseudomonas Quinolone Signal Dioxygenase AqdC in Combination with the N-Acylhomoserine Lactone Lactonase QsdA

2019 ◽  
Vol 87 (10) ◽  
Author(s):  
Franziska S. Birmes ◽  
Ruth Säring ◽  
Miriam C. Hauke ◽  
Niklas H. Ritzmann ◽  
Steffen L. Drees ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Rhodococcus Erythropolis ◽  
Quorum Quenching ◽  
Signal Molecules ◽  
Content Type ◽  
Acylhomoserine Lactone ◽  
Regulatory Effects ◽  
Epithelial Lung Cells

ABSTRACT The nosocomial pathogen Pseudomonas aeruginosa regulates its virulence via a complex quorum sensing network, which, besides N-acylhomoserine lactones, includes the alkylquinolone signal molecules 2-heptyl-3-hydroxy-4(1H)-quinolone (Pseudomonas quinolone signal [PQS]) and 2-heptyl-4(1H)-quinolone (HHQ). Mycobacteroides abscessus subsp. abscessus, an emerging pathogen, is capable of degrading the PQS and also HHQ. Here, we show that although M. abscessus subsp. abscessus reduced PQS levels in coculture with P. aeruginosa PAO1, this did not suffice for quenching the production of the virulence factors pyocyanin, pyoverdine, and rhamnolipids. However, the levels of these virulence factors were reduced in cocultures of P. aeruginosa PAO1 with recombinant M. abscessus subsp. massiliense overexpressing the PQS dioxygenase gene aqdC of M. abscessus subsp. abscessus, corroborating the potential of AqdC as a quorum quenching enzyme. When added extracellularly to P. aeruginosa cultures, AqdC quenched alkylquinolone and pyocyanin production but induced an increase in elastase levels. When supplementing P. aeruginosa cultures with QsdA, an enzyme from Rhodococcus erythropolis which inactivates N-acylhomoserine lactone signals, rhamnolipid and elastase levels were quenched, but HHQ and pyocyanin synthesis was promoted. Thus, single quorum quenching enzymes, targeting individual circuits within a complex quorum sensing network, may also elicit undesirable regulatory effects. Supernatants of P. aeruginosa cultures grown in the presence of AqdC, QsdA, or both enzymes were less cytotoxic to human epithelial lung cells than supernatants of untreated cultures. Furthermore, the combination of both aqdC and qsdA in P. aeruginosa resulted in a decline of Caenorhabditis elegans mortality under P. aeruginosa exposure.

Characteristics of Virulent Vibrio parahaemolyticus Isolated from Oregon and Washington

2007 ◽  
Vol 70 (4) ◽  
pp. 1011-1016 ◽  
Author(s):  
TSAI-HSIN CHIU ◽  
JINGYUN DUAN ◽  
YI-CHENG SU
Keyword(s):  
Pacific Northwest ◽  
Virulence Factors ◽  
Gel Electrophoresis ◽  
Vibrio Parahaemolyticus ◽  
Pulsed Field Gel Electrophoresis ◽  
Outbreak Strain ◽  
Pulsed Field ◽  
Clinical Strains ◽  
Virulent Strains ◽  
The Pacific

Thirty-four virulent strains of Vibrio parahaemolyticus containing tdh and/or trh genes isolated from Oregon and Washington coastal water were analyzed for O-group antigens and urease activity, and by pulsed-field gel electrophoresis. Six O serotypes (O1, O3, O4, O5, O10, and O11) were identified among the isolates, with the O5 group (19 isolates) being the most prevalent, followed by the O1 group (9 isolates). Nearly all (33 of 34) isolates were capable of producing urease, which reaffirmed the correlation between urease production and virulence factors of V. parahaemolyticus strains isolated from the Pacific Northwest. Pulsed-field gel electrophoresis analysis with NotI and SfiI digestions of the 34 V. parahaemolyticus isolates plus five clinical strains revealed 22 patterns (N1S1 to N20S22), with N1S1 (25.6%) being the most common, followed by N2S2 (10.3%). Nine Oregon isolates were grouped with a 1997 Oregon outbreak strain (027-1C1) with the same serotype (O5), virulence factors (tdh+ and trh+), and genotype (N1S1). Three Washington isolates were found to share the same serotype (O1), virulence factors (tdh+ and trh+), and genotype (N2S2) with a 1997 Washington outbreak strain (10293). The repetitive isolation of virulent strains of V. parahaemolyticus identical to clinical strains involved in previous outbreaks indicates potential hazards associated with oyster consumption. These data may be useful in risk assessment of V. parahaemolyticus infections associated with raw oyster consumption in Oregon and Washington.

scholarly journals Vibrio parahaemolyticus Inhibition of Rho Family GTPase Activation Requires a Functional Chromosome I Type III Secretion System

2008 ◽  
Vol 76 (5) ◽  
pp. 2202-2211 ◽  
Author(s):  
Timothy Casselli ◽  
Tarah Lynch ◽  
Carolyn M. Southward ◽  
Bryan W. Jones ◽  
Rebekah DeVinney
Keyword(s):  
Virulence Factors ◽  
Hela Cells ◽  
Type Iii Secretion ◽  
Vibrio Parahaemolyticus ◽  
Secretion System ◽  
Type Iii ◽  
Rho Family Gtpases ◽  
Rho Family ◽  
Gtpase Activation ◽  
Chromosome I

ABSTRACT Vibrio parahaemolyticus is a leading cause of seafood-borne gastroenteritis; however, its virulence mechanisms are not well understood. The identification of type III secreted proteins has provided candidate virulence factors whose functions are still being elucidated. Genotypic strain variability contributes a level of complexity to understanding the role of different virulence factors. The ability of V. parahaemolyticus to inhibit Rho family GTPases and cause cytoskeletal disruption was examined with HeLa cells. After HeLa cells were infected, intracellular Rho activation was inhibited in response to external stimuli. In vitro activation of Rho, Rac, and Cdc42 isolated from infected HeLa cell lysates was also inhibited, indicating that the bacteria were specifically targeting GTPase activation. The inhibition of Rho family GTPase activation was retained for clinical and environmental isolates of V. parahaemolyticus and was dependent on a functional chromosome I type III secretion system (CI-T3SS). GTPase inhibition was independent of hemolytic toxin genotype and the chromasome II (CII)-T3SS. Rho inhibition was accompanied by a shift in the total actin pool to its monomeric form. These phenotypes were abrogated in a mutant strain lacking the CI-T3S effector Vp1686, suggesting that the inhibiting actin polymerization may be a downstream effect of Vp1686-dependent GTPase inhibition. Although Vp1686 has been previously characterized as a potential virulence factor in macrophages, our findings reveal an effect on cultured HeLa cells. The ability to inhibit Rho family GTPases independently of the CII-T3SS and the hemolytic toxins may provide insight into the mechanisms of virulence used by strains lacking these virulence factors.

scholarly journals DNA-Binding Protein HU Coordinates Pathogenicity in Vibrio parahaemolyticus

2015 ◽  
Vol 197 (18) ◽  
pp. 2958-2964 ◽  
Author(s):  
Ngoc Quang Phan ◽  
Takashi Uebanso ◽  
Takaaki Shimohata ◽  
Mutsumi Nakahashi ◽  
Kazuaki Mawatari ◽  
...  
Keyword(s):  
Gene Expression ◽  
Growth Rate ◽  
Virulence Factors ◽  
Vibrio Parahaemolyticus ◽  
Binding Protein ◽  
Negative Regulator ◽  
Independent Manner ◽  
Content Type ◽  
Expression Levels ◽  
Hu Proteins

ABSTRACTHU is one of the most abundant nucleoid-associated proteins in bacterial cells and regulates the expression of many genes involved in growth, motility, metabolism, and virulence. It is known thatVibrio parahaemolyticuspathogenicity is related to its characteristic rapid growth and that type III secretion system 1 (T3SS1) contributes to its cytotoxicity. However, it is not known if HU plays a role in the pathogenicity ofV. parahaemolyticus. In the present study, we investigated the effect of HU proteins HU-2 (HUα) (V. parahaemolyticus2911 [vp2911]) and HUβ (vp0920) on the pathogenicity ofV. parahaemolyticus. We found that a deletion of both HU subunits (yielding the ΔHUs [Δvp0920Δvp2911] strain), but not single deletions, led to a reduction of the growth rate. In addition, expression levels of T3SS1-related genes, includingexsA(positive regulator),exsD(negative regulator),vp1680(cytotoxic effector), andvp1671(T3SS1 apparatus), were reduced in the ΔHUs strain compared to the wild type (WT). As a result, cytotoxicity to HeLa cells was decreased in the ΔHUs strain. The additional deletion ofexsDin the ΔHUs strain restored T3SS1-related gene expression levels and cytotoxicity but not the growth rate. These results suggest that the HU protein regulates the levels of T3SS1 gene expression and cytotoxicity in a growth rate-independent manner.IMPORTANCENucleoid-binding protein HU regulates cellular behaviors, including nucleoid structuring, general recombination, transposition, growth, replication, motility, metabolism, and virulence. It is thought that both the number of bacteria and the number of virulence factors may affect the pathogenicity of bacteria. In the present study, we investigated which factor(s) has a dominant role during infection in one of the most rapidly growing bacterial species,Vibrio parahaemolyticus. We found thatV. parahaemolyticuscytotoxicity is regulated, in a growth rate-independent manner, by the HU proteins through regulation of a number of virulence factors, including T3SS1 gene expression.

Virulence factors involved in the pathogenesis of Vibrio parahaemolyticus

2013 ◽  
Vol 24 (2) ◽  
pp. 41-47 ◽  
Author(s):  
Diana R. Zamora-Pantoja ◽  
Elsa I. Quiñones-Ramírez ◽  
Francisco J. Fernández ◽  
Carlos Vázquez-Salinas
Keyword(s):  
Virulence Factors ◽  
Vibrio Parahaemolyticus
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