Influence of environmental parameters on total and pathogenic Vibrio parahaemolyticus isolated from mussels and clams.

Safety and toxicity assessment of Lactobacillus salivarius AP-32 with Probiotic potential in vivo and in vitro.

Antimicrobial peptide LRSG08 from Penaeus vannamei exhibits antibacterial activity against Vibrio spp. in aquatic products.

Development and validation of TaqMan-based real-time PCR assays for translucent post larvae disease (TPD) detection in Penaeus vannamei.

Inhibition mechanism of linalool on Vibrio parahaemolyticus biofilms and its removal of biofilms on the surfaces of shrimp and its processing materials.

Butyrate-producing bacteria (BPB) are widely used as additives in aquaculture because of the beneficial effects of the butyrate they produce. However, most available BPB currently are of terrestrial origin, which are quite different from aquatic animals, resulting in profoundly unstable probiotic performance. This study isolated a novel, indigenous BPB, Clostridium moniliforme G18, from the gut of mud crabs, Scylla paramamosain. The strain demonstrated robust butyric acid production, tolerance to gastrointestinal conditions (pH 4-9, 0-3% NaCl, 0.4-1.0% bile salts), antibiotic sensitivity, pathogen inhibition, and non-hemolytic activity. Dietary supplementation with G18 alone or in combination with resistant starch and galactooligosaccharides (GR18) significantly enhanced mud crab body weight (P < 0.05). The supplementation improved intestinal health by enhancing histomorphology and upregulating tight junction genes (ZO-1 and Claudin). Furthermore, it boosted antioxidant capacity (elevated SOD and CAT; reduced MDA), modulated immune responses (increased AKP and ACP; reduced ALT and AST, P < 0.05), and increased intestinal butyrate levels. Analysis of the gut microbiota of mud crabs fed G18 alone or in combination with prebiotics revealed an increase in alpha diversity and beneficial composition changes (including reduced Vibrionaceae and elevated Proteocatella, P < 0.05). Following Vibrio parahaemolyticus challenge, mud crabs fed G18 and GR18 showed significantly higher survival rate (66.7% and 73.3%, respectively, P < 0.05) versus 53.3% in the control group. These diets mitigated intestinal damage, restored immune and antioxidant parameters, and enhanced the expression of barrier function genes. These results establish indigenous C. moniliforme G18 as a highly promising probiotic candidate for enhancing growth and health in mud crabs.

This study aimed to isolate lactic acid bacteria (LAB) from the intestines of whiteleg shrimp ( Litopenaeus vannamei ) for potential probiotic use and to evaluate the effects of dietary synbiotic supplementation on shrimp growth performance and digestive enzyme activity. A total of 249 LAB isolates were obtained from shrimp intestines collected in extensive ponds in Ca Mau province. Among these, 15 isolates exhibited strong antagonistic activity against Vibrio parahaemolyticus , with inhibition zones ranging from 6 to 11 mm. Most isolates were Gram-positive, non-motile, non-spore-forming, and exhibited cell shapes ranging from short rods to spherical. Four isolates demonstrated strong protease and leu-aminopeptidase activities, although α-amylase production was relatively low. Strain LAB8.1CM was identified as Lactiplantibacillus plantarum based on 16S rRNA gene sequencing (99.7% homology) and exhibited promising probiotic characteristics, indicating its potential as a safe feed additive. In a 60-day feeding trial, shrimp were assigned to five dietary treatments: control (basal diet), prebiotic (0.2% banana extract), probiotic ( L. plantarum 10 8 CFU/kg), synbiotic-0.2% (banana extract 0.2% + L. plantarum 10 8 CFU/kg), and synbiotic-0.4% (banana extract 0.4% + L. plantarum 10 8 CFU/kg), each with three replicates. Synbiotic supplementation significantly improved digestive enzyme activities, including α-amylase, β-galactosidase, protease, and leu-aminopeptidase. Growth performance parameters, such as weight gain, daily weight gain, specific growth rate, and feed conversion ratio, were also significantly enhanced, particularly in shrimp fed the synbiotic-0.2% diet. Survival rates did not differ significantly among treatments. These findings indicate that dietary supplementation with selected LAB strains, in combination with prebiotics, can effectively enhance growth, digestion, and health in whiteleg shrimp, highlighting their potential as synbiotic feed additives for sustainable aquaculture practices.

Increased global consumption of fish and seafood, driven by their nutritional benefits, has highlighted concerns regarding bacterial contamination, particularly by Vibrio parahaemolyticus. This study investigates the prevalence and associated risk factors of V. parahaemolyticus in fish samples collected from three cities in the Kurdistan region of Iraq. A total of 185 fish samples were collected and analyzed for V. parahaemolyticus contamination using enrichment and isolation protocols. The overall detection rate was 9.19%, with no significant differences observed between cities, fish age, sex, or species. However, fish exhibiting abnormal physical signs, such as loose scales, pale gills, and bulging eyes, showed significantly higher contamination rates. Seasonal trends indicated a decreasing, though not statistically significant, trend in contamination from spring to summer. The cortisol level and lymphocyte count showed significant elevation, with a decrease in red cell count and abnormal physical appearance in fish compared with normal fish. These findings highlight the role of physiological and environmental factors in V. parahaemolyticus contamination and emphasize the need for improved biosafety measures in freshwater fish handling and processing to mitigate public health risks.

In vitro bacterial competition assays were performed to evaluate the ecological and antibacterial role of the PirABvp toxin complex produced by Vibrio parahaemolyticus Vp278. When co-cultured with V. cholerae, the PirABvp producing strains exhibited competitive dominance, eliminating V. cholerae after 19-24 h, whereas non-producing strains coexisted with V. cholerae throughout the incubation period. Quantification and immunodetection analyses confirmed a time-dependent increase in PirBvp levels during competition, reaching up to 350 ng/mL, while non-producer strains showed no toxin production. Recombinant PirBvp displayed direct antibacterial activity, causing up to 66.6% reduction in V. cholerae growth and a 5.2-log decrease in CFU at 20 μg/mL. Similarly, A. fischeri exhibited dose-dependent inhibition of bioluminescence and viability, with cell counts reduced from 3.0 × 109 to 5.2 × 105 CFU/mL at 20 μg/mL. The inhibitory effect was markedly reduced when PirBvp was preincubated with IPTG and the glycoprotein Fetuin, suggesting that the jacalin-like lectin domain, which binds to amino sugars in the bacterial membrane, is essential for its antibacterial action. These findings demonstrate that PirBvp contributes to interspecific competition and ecological dominance of V. parahaemolyticus through direct, lectin-mediated antibacterial activity.

This study evaluates the effects of supplementing whiteleg shrimp (Penaeus vannamei) feed with Streptomyces strains (TM1, TM2, TM7, TM21, TM22), Bacillus strains (AQ1, BIO2, BAL3), and their combinations at different densities (106, 107, and 108 CFU/g) on growth performance, immune response, water quality, and Vibrio control. Two experiments were conducted over 36 days: the first tested individual Bacillus and Streptomyces consortia at varying doses, and the second assessed combined treatments. Survival was monitored after shrimp were fed probiotics and subsequently challenged with Vibrio parahaemolyticus. Results showed significant improvements in final body weight (FBW), daily weight gain (DWG), feed conversion ratio (FCR), survival rate (SR), and total hemocyte count (THC) in all probiotic treatments, with greater benefits at higher probiotic doses. Combined probiotic treatments consistently produced greater numerical enhancements in growth performance than single-strain applications, indicating synergistic effects between Streptomyces and Bacillus consortia. Water quality responses differed between probiotic types, with Streptomyces treatments providing rapid early reductions in total ammonia nitrogen (TAN) and nitrite, whereas Bacillus-supplemented treatments achieved delayed but more stable and higher removal efficiencies toward the end of the experiment. The combination treatment B8S8 (Bacillus and Streptomyces at 108 CFU/g each) yielded the greatest growth enhancement (approximately 143% FBW and 149% DWG increase relative to the control) and effectively reduced Vibrio counts, achieving 2.9 and 3.1 log reductions in water (B6S8 and B8S8, respectively) and 3.5 and 3.6 log reductions in the shrimp gastrointestinal tract. In combined treatments, TAN and nitrite removal efficiencies exceeded 95% by Day 36, with no significant differences among probiotic combinations. This probiotic supplementation strategy enhances shrimp health and growth in recirculating aquaculture systems at 100 shrimp/100 L, suggesting that combined Streptomyces and Bacillus consortia are a promising approach for improving P. vannamei aquaculture productivity.

V. parahaemolyticus has several virulence factors, including thermostable direct hemolysin (TDH), TDH-related hemolysin (TRH), and two separate type III secretion systems (T3SSs), T3SS1 and T3SS2. T3SS1 is responsible for cytotoxicity, primarily through the activity of its effector VP1680. To gain a detailed understanding of the relationship between the amount of effector, its expression timing, and cytotoxicity, a system is required to regulate protein expression levels and timing. In the present study, we developed an effector protein expression system controlled by an arabinose-dependent transcription factor and found that cytotoxicity toward mammalian cells increased in a VP1680-dependent manner. To ensure specific protein degradation, we also established a targeted protein degradation system, including VP0917 (ClpP) and VP0918 (ClpX)-, or VP0917 and VP1014 (ClpA)-mediated degradation of ssrA-tagged proteins (proteins bearing the C-terminal degradation tag encoded by tmRNA). By combining these systems, more than 50% of the targeted protein could be degraded within 20 min. As a byproduct of creating the systems, we obtained an enhanced green fluorescent protein variant that emits strong fluorescence in V. parahaemolyticus. The protein degradation system developed in this study has demonstrated the potential to control intracellular protein levels to a certain extent. Moreover, experimentally controlling intracellular protein levels will allow for a more detailed examination of the relationship between protein quantity and cellular phenotype, potentially overcoming the limitations of the "all-or-nothing" model.

This study was carried out to determine the presence of Vibrio parahaemolyticus (V. parahaemolyticus) from shrimps (n=90) obtained from fishermen in Aydın province. According to traditional methods, 40 isolates gave suspicious positive results on Thiosulfate Citrate Bile Sucrose (TCBS) agar. All V. parahaemolyticus strain known to have thermolabile hemolysin encoded by tlh gene as species marker. In order to identify suspicious strains, tlh genes specific to V. parahaemolyticus were detected by using tlh primers. Eleven strains of the suspicious isolates gave a positive reaction with Real Time PCR. Antibiotic resistance of the isolates gave a positive reaction as V. parahaemolyticus by real-time PCR, penicillin G (10units), clindamycin (2µg), piperacillin (100µg), amoxicillin-clavulanic acid (30µg), ciprofloxacin (5µg) and gentamicin (10µg) was determined by disk diffusion. All isolates showed resistance to Penicillin G and Clindamycin and One isolate showed multiple resistance to all antibiotics tested. All isolates, except the isolate showing multiple antibiotic resistance, were susceptible to Piperacillin, Ciprofloxacin and Gentamicin. As a result, it is recommended to establish effective control measures to reduce the risk of V. parahaemolyticus infection in terms of public health, it is recommended to use effective methods routinely to ensure the safety of foods and to detect V. parahaemolyticus in foods and the environment.

Dietary supplementation with plant essential oils-loaded chitosan nanoparticles improves growth, body composition, digestive enzymes, and immune response in whiteleg shrimp (Litopenaeus vannamei): Influence on histopathology and survivability against Vibrioparahaemolyticus.

Differential regulation of key virulence factors by SbfR in Vibrio parahaemolyticus.

Combined histopathological, immunoenzymatic and transcriptomic analyses reveal the immune response mechanisms of silver pomfret infected by Vibrio parahaemolyticus.

The role of Surfactin, Skf/Sdp toxins, and phospholipids in the biocontrol ability of Bacillus subtilis JSHY-K3 against acute hepatopancreatic necrosis disease in shrimp aquaculture.

RPA-CRISPR/Cas12a-coupled microfluidic biosensor enabling on-site, sensitive quantification of Vibrio parahaemolyticus.

Correlation of Elastic Light Scatter pattern analysis of clinical and shellfish strains of Vibrio parahaemolyticus from New Zealand with virulence characteristics.

Profiles of gut microbiome in Litopenaeus vannamei artificially infected with Vibrio parahaemolyticus causing translucent post-larva disease.

Screening of proteins interacting with vhvp-2 protein from Vibrio parahaemolyticus causing translucent post-larvae disease in Pacific white shrimp Litopenaeus vannamei.