Complete genome sequence ofVibrio parahaemolyticusFORC_023 isolated from raw fish storage water

Abstract

Vibrio parahaemolyticusis a Gram-negative halophilic bacterium that causes food-borne gastroenteritis in humans who consumeV. parahaemolyticus-contaminated seafood.The FORC_023 strain was isolated from raw fish storage water, containing live fish at a sashimi restaurant. Here, we aimed to sequence and characterize the genome of the FORC_023 strain. The genome of the FORC_023 strain showed two circular chromosomes, which contained 4227 open reading frames (ORFs), 131 tRNA genes and 37 rRNA genes. Although the genome of FORC_023 did not include major virulence genes, such as genes encoding thermostable direct hemolysin (TDH) and TDH-related hemolysin (TRH), it contained genes encoding other hemolysins, secretion systems, iron uptake-related proteins and severalV. parahaemolyticusislands. The highest average nucleotide identity value was obtained between the FORC_023 strain and UCM-V493 (CP007004-6). Comparative genomic analysis of FORC_023 with UCM-V493 revealed that FORC_023 carried an additional genomic region encoding virulence factors, such as repeats-in-toxin and type II secretion factors. Furthermore,in vitrocytotoxicity testing showed that FORC_023 exhibited a high level of cytotoxicity toward INT-407 human epithelial cells. These results suggested that the FORC_023 strain may be a food-borne pathogen.

Recovery of Pasteurization-Resistant Vibrio parahaemolyticus from Seafoods Using a Modified, Two-Step Enrichment

“…The results revealing positive KP activity and tlh amplicons suggest the presence of environmental V. parahaemolyticus pathogens [ 19 , 20 ], and that these strains (i.e., VHT1 and VHT2 derived strains, VHT79, VHT80, and VHT81) ( Table 5 and Table 7 ) possess heat-stable hemolysin gene(s), such as tlh , and that it encodes a heat-stress protecting product, possibly suggesting a positive correlation between V. parahaemolyticus heat resistance (i.e., 62 °C, 8 h) and persistent vibriosis cases, as noted by Ueda et al [ 75 ], whose work determined a positive correlation between thermolabile protein expression and thermotolerance in a member of Gram-negative bacteria. The PCR results confirm that this pathogen could use tdh -independent hemolysin(s), such as trh [ 38 , 71 ], tlh [ 2 , 38 ], VP3048 putative hemolysin [ 48 ], and/or others [ 71 ] for exhibiting KP activity ( Table 7 ), and that urease-positive V. parahaemolyticus strains do not simultaneously possess a tdh -encoding gene, as noted by Wang et al [ 63 ]. Additionally, the data suggest that tdh and tlh hemolysins are not essential in environmental V. parahaemolyticus metabolism, as these genes were absent in a subset ( tlh gene) or all ( tdh gene) of our culture isolates ( Table 6 ).…”

“…However, the present study revealed that select strains, the heat-resistant, urease + V. parahaemolyticus VHT1 and VHT2, were KP + ( Table 7 ). Letchumanan et al [ 38 ] and Chung et al [ 71 ] noted other V. parahaemolyticus hemolysins, such as the thermolabile hemolysin ( tlh ) and thermostable direct hemolysin ( tdh ), respectively, that could contribute to KP + . Hemolysin gene-specific PCR analyses revealed that the V. parahaemolyticus strains VHT1 and VHT2 were tdh − but tlh + ( Table 7 ).…”

Occurrence and antibiotic resistance of Vibrio parahaemolyticus isolated from the Tunisian coastal seawater

“…This virulence was associated especially with the production of thermostable direct haemolysin (tdh) and/or thermostable-related haemolysin (trh) (Wang et al 2018), also known as the Kanagawa phenomenon (KP) (Leoni et al 2016). Nevertheless, virulence was reported in some negative tdh and trh strains (Ottaviani et al 2012;Chung et al 2016). Some specific clones of V. parahaemolyticus were recognized as responsible for pandemic episodes such as O4:K68; O3:K6; O3:K69 serovars (Haendiges et al 2015;Han et al 2017).…”

Functional Analysis of Hypothetical Proteins of Vibrio parahaemolyticus Reveals the Presence of Virulence Factors and Growth-Related Enzymes With Therapeutic Potential

“…In gram-negative bacteria, Type VI secretion systems are associated with the machinery that is required for injecting effector proteins into eukaryotic cells to exert virulence, symbiosis, as well as antibacterial activity. 130 - 132 We also identified S-type Pyocin (MSR16_hyp_89 and MSR17_hyp_256), an effector of the type VI secretion system that has the potential to mediate antibacterial toxicity. 133 , 134 …”

“…In gram-negative bacteria, Type VI secretion systems are associated with the machinery that is required for injecting effector proteins into eukaryotic cells to exert virulence, symbiosis, as well as antibacterial activity. [130][131][132] We also identified S-type Pyocin (MSR16_hyp_89 and MSR17_ hyp_256), an effector of the type VI secretion system that has the potential to mediate antibacterial toxicity. 133,134 V. parahaemolyticus also encodes genes for the formation of the type III secretion system, and we identified Type III secretion chaperone CesT among the hypothetical proteins (MSR16_hyp_195, MSR16_hyp_1271, MSR17_hyp_116, and MSR17_hyp_745).…”