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
2010 ◽  
Vol 78 (4) ◽  
pp. 1772-1780 ◽  
Author(s):  
Hirotaka Hiyoshi ◽  
Toshio Kodama ◽  
Tetsuya Iida ◽  
Takeshi Honda

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.


2019 ◽  
Vol 10 ◽  
Author(s):  
Yi Sun ◽  
Du Guo ◽  
Zi Hua ◽  
Huihui Sun ◽  
Zhanwen Zheng ◽  
...  

2007 ◽  
Vol 70 (4) ◽  
pp. 1011-1016 ◽  
Author(s):  
TSAI-HSIN CHIU ◽  
JINGYUN DUAN ◽  
YI-CHENG SU

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.


2008 ◽  
Vol 76 (5) ◽  
pp. 2202-2211 ◽  
Author(s):  
Timothy Casselli ◽  
Tarah Lynch ◽  
Carolyn M. Southward ◽  
Bryan W. Jones ◽  
Rebekah DeVinney

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.


2013 ◽  
Vol 26 (1) ◽  
pp. 115-134 ◽  
Author(s):  
Maha Bouzid ◽  
Paul R. Hunter ◽  
Rachel M. Chalmers ◽  
Kevin M. Tyler

SUMMARYCryptosporidiumis a protozoan parasite of medical and veterinary importance that causes gastroenteritis in a variety of vertebrate hosts. Several studies have reported different degrees of pathogenicity and virulence amongCryptosporidiumspecies and isolates of the same species as well as evidence of variation in host susceptibility to infection. The identification and validation ofCryptosporidiumvirulence factors have been hindered by the renowned difficulties pertaining to thein vitroculture and genetic manipulation of this parasite. Nevertheless, substantial progress has been made in identifying putative virulence factors forCryptosporidium. This progress has been accelerated since the publication of theCryptosporidium parvumandC. hominisgenomes, with the characterization of over 25 putative virulence factors identified by using a variety of immunological and molecular techniques and which are proposed to be involved in aspects of host-pathogen interactions from adhesion and locomotion to invasion and proliferation. Progress has also been made in the contribution of host factors that are associated with variations in both the severity and risk of infection. Here we provide a review comprised of the current state of knowledge onCryptosporidiuminfectivity, pathogenesis, and transmissibility in light of our contemporary understanding of microbial virulence.


2015 ◽  
Vol 81 (21) ◽  
pp. 7394-7402 ◽  
Author(s):  
Nan Li ◽  
Ting Qin ◽  
Xiao Lin Zhang ◽  
Bei Huang ◽  
Zhi Xin Liu ◽  
...  

ABSTRACTFlavobacterium columnareis an important bacterial pathogen of freshwater fish that causes high mortality of infected fish and heavy economic losses in aquaculture. The pathogenesis of this bacterium is poorly understood, in part due to the lack of efficient methods for genetic manipulation. In this study, a gene deletion strategy was developed and used to determine the relationship between the production of chondroitin lyases and virulence. TheF. johnsoniaeompApromoter (PompA) was fused tosacBto construct a counterselectable marker forF. columnare.F. columnarecarrying PompA-sacBfailed to grow on media containing 10% sucrose. A suicide vector carrying PompA-sacBwas constructed, and a gene deletion strategy was developed. Using this approach, the chondroitin lyase-encoding genes,cslAandcslB, were deleted. The ΔcslAand ΔcslBmutants were both partially deficient in digestion of chondroitin sulfate A, whereas a double mutant (ΔcslAΔcslB) was completely deficient in chondroitin lyase activity. Cells ofF. columnarewild-type strain G4and of the chondroitin lyase-deficient ΔcslAΔcslBmutant exhibited similar levels of virulence toward grass carp in single-strain infections. Coinfections, however, revealed a competitive advantage for the wild type over the chondroitin lyase mutant. The results indicate that chondroitin lyases are not essential virulence factors ofF. columnarebut may contribute to the ability of the pathogen to compete and cause disease in natural infections. The gene deletion method developed in this study may be employed to investigate the virulence factors of this bacterium and may have wide application in many other members of the phylumBacteroidetes.


2015 ◽  
Vol 197 (18) ◽  
pp. 2958-2964 ◽  
Author(s):  
Ngoc Quang Phan ◽  
Takashi Uebanso ◽  
Takaaki Shimohata ◽  
Mutsumi Nakahashi ◽  
Kazuaki Mawatari ◽  
...  

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.


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

2016 ◽  
Vol 49 (2) ◽  
pp. 116-123 ◽  
Author(s):  
Sukyung Kim ◽  
Sera An ◽  
Bomi Park ◽  
Eun-Gyoung Oh ◽  
Ki Cheol Song ◽  
...  

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