Adaptations of Vibrio parahaemolyticus to Stress During Environmental Survival, Host Colonization, and Infection

Abstract

Vibrio parahaemolyticus (Vp) is an aquatic Gram-negative bacterium that may infect humans and cause gastroenteritis and wound infections. The first pandemic of Vp associated infection was caused by the serovar O3:K6 and epidemics caused by the other serovars are increasingly reported. The two major virulence factors, thermostable direct hemolysin (TDH) and/or TDH-related hemolysin (TRH), are associated with hemolysis and cytotoxicity. Vp strains lacking tdh and/or trh are avirulent and able to colonize in the human gut and cause infection using other unknown factors. This pathogen is well adapted to survive in the environment and human host using several genetic mechanisms. The presence of prophages in Vp contributes to the emergence of pathogenic strains from the marine environment. Vp has two putative type-III and type-VI secretion systems (T3SS and T6SS, respectively) located on both the chromosomes. T3SS play a crucial role during the infection process by causing cytotoxicity and enterotoxicity. T6SS contribute to adhesion, virulence associated with interbacterial competition in the gut milieu. Due to differential expression, type III secretion system 2 (encoded on chromosome-2, T3SS2) and other genes are activated and transcribed by interaction with bile salts within the host. Chromosome-1 encoded T6SS1 has been predominantly identified in clinical isolates. Acquisition of genomic islands by horizontal gene transfer provides enhanced tolerance of Vp toward several antibiotics and heavy metals. Vp consists of evolutionarily conserved targets of GTPases and kinases. Expression of these genes is responsible for the survival of Vp in the host and biochemical changes during its survival. Advanced genomic analysis has revealed that various genes are encoded in Vp pathogenicity island that control and expression of virulence in the host. In the environment, the biofilm gene expression has been positively correlated to tolerance toward aerobic, anaerobic, and micro-aerobic conditions. The genetic similarity analysis of toxin/antitoxin systems of Escherichia coli with VP genome has shown a function that could induce a viable non-culturable state by preventing cell division. A better interpretation of the Vp virulence and other mechanisms that support its environmental fitness are important for diagnosis, treatment, prevention and spread of infections. This review identifies some of the common regulatory pathways of Vp in response to different stresses that influence its survival, gut colonization and virulence.

The pathogen Vibrio alginolyticus H1 and its antagonist Pseudoalteromonas piscicida H2 associated with the health status of cuttlefish Sepia pharaonis

“…Another outstanding characteristic of V. alginolyticus H1 was its highly extraordinary motility. The expressions of the virulence related factors are significantly influenced by environmental factors, especially the factors that are involved in host immunity, such as oxidative stress and iron limitation [ 32 , 53 , 54 ]. Similar to the previous reports [ 55 , 56 ], ROS and H 2 O 2 exhibited the same effects on the virulence factors of V. alginolyticus H1.…”

Insights into the Vibrio Genus: A One Health Perspective from Host Adaptability and Antibiotic Resistance to In Silico Identification of Drug Targets

“…Moreover, transcriptional proteins and signal transduction mechanisms are highly conserved in human pathogens; this fully reflects how bacteria can adapt to different environments, such as saline water and the human body. Changes in physicochemical parameters such as pH, osmolarity, temperature, and salinity can quickly kill unprepared microorganisms [ 44 , 45 , 46 ]. However, perceiving such changes through stimuli (such as the presence of bile in the human gastrointestinal tract) is one of the main obstacles to be overcome by some species by altering their gene expression, for example, by reallocating outer membrane proteins, thus allowing survival in different acidic concentrations [ 47 ].…”

Modeling pH and Temperature Effects as Climatic Hazards in Vibrio Vulnificus and Vibrio Parahaemolyticus Planktonic Growth and Biofilm Formation

“…Dense cyanobacteria blooms in these dynamic ecosystems can also increase water column pH > 9 due to metabolically‐driven decreases in dissolved CO2 to less than 1 μmol per liter (Adams et al., 2022 ; Huisman et al., 2018 ). Changes in environmental parameters not only affect the growth and distribution of Vibrio species but may also alter their gene expression, resulting in enhanced virulence profiles (Billaud et al., 2022 ; Correa Velez & Norman, 2021 ; Pazhani et al., 2021 ; Williams et al., 2014 ). To understand the changing abundances of Vibrio spp.…”