Prevalence of Vibrio vulnificus in Shrimp Farm and Seafood Processing Environment: Molecular Characterization, Antibiotic Resistance and Mitigation Measures
Jul 2026· Thalassas: An International Journal of Marine Sciences· Vol 42· 0 citations· 62 references
TL;DR
The importance of monitoring V. vulnificus in shrimp production systems and the need for effective antimicrobial resistance management strategies are highlighted, highlighting the importance of effective disinfection practices in mitigating the risk of V. vulnificus contamination in the seafood processing industry.
Vibrio parahaemolyticus represents a contaminant of emerging concern in coastal aquaculture ecosystems, where antibiotic residues associated with intensive shrimp farming can drive the co-selection of antimicrobial resistance (AMR), virulence, and environmental persistence. The Vedaranyam Canal in Tamil Nadu, India, forms a critical interface linking estuarine ecology, brackishwater aquaculture, and seafood supply chains. In this study, 356 confirmed V. parahaemolyticus isolates recovered from canal water (n = 165), shrimp farm pond shrimp (n = 102), and retail seafood shrimp (n = 89) were subjected to comprehensive phenotypic and molecular characterization. Antimicrobial susceptibility testing revealed a high prevalence of multidrug resistance (80.6%), with multiple antibiotic resistance (MAR) indices ranging from 0.16 to 0.96; pond shrimp isolates exhibited the greatest resistance burden. Elevated resistance frequencies were observed against penicillin (97%), methicillin (91%), erythromycin (84%), and norfloxacin (82%). Virulence gene screening showed universal detection of toxR and tlh, whereas tdh and trh were detected in 15.2% and 7.3% of isolates, respectively. Among AMR determinants, tetA (41.6%), blaTEM (39.6%), and sul1 (34.3%) predominated. Biofilm formation was detected in 77.0% of isolates, including 12.6% strong biofilm producers, while efflux pump activity was observed in 41.0%. Significant associations were identified between strong biofilm formation and MDR phenotype (OR = 6.2, p < 0.001), and between efflux pump activity and MDR (OR = 4.8, p < 0.001). Seasonal prevalence increased during summer and monsoon periods and showed a positive correlation with temperature (r = 0.45, p < 0.05). These findings identify the Vedaranyam canal-aquaculture continuum as a hotspot for AMR dissemination and persistence, highlighting the need for integrated One Health surveillance.
Abisha Juliet Mary Sj, M. Petchimuthu, S. Deepika et al.· Environmental Pollution· 0 citations
In the present study, samples (hepatopancreas and muscles) from 100 cultured shrimp (Penaeus indicus) were collected. The water samples (n = 30) were obtained from the same shrimp aquaculture farms located at Damietta Governorate in Egypt. An additional 30 samples of human stool were also taken from fish workers who consumed or handled shrimp in the farms. Traditional and regular molecular methods were used for the isolation of Vibrio spp. The investigation identified 165 (63.5%) Vibrio spp. with predominance of V. fluvialis (41.2%), V. alginolyticus (31.5%) and V. parahaemolyticus (7.9%). Findings of large-scale multidrug resistance (77.5% of isolates) and also of the presence of carbapenemase genes (blaKPC, blaNDM) and extended-spectrum beta-lactamase genes (blaCTX-M, blaTEM) were important discoveries. This strong resistance, due to the fact that a lot of pressure has been exerted on the aquaculture through the use of antibiotics, demonstrates the ineffectiveness of antibiotics in combating vibriosis in shrimp farming. The clinical signs observed in shrimps were red and fragile shells, and pale hepatopancreas. Histopathological analyses corroborated the presence of sloughed hepatopancreas epithelium, vacuolation, oedema and hemocytic infiltration. Regarding sequence similarity, the gyrB gene was sequenced, and all of the shrimp hepatopancreas isolates showed 100% sequence identity with the human stool isolates, which indicates potential genetic relatedness of V. fluvialis isolates. However, because of the conserved nature of gyrB, higher resolution tools are needed to verify transmission (e.g., MLST or WGS). The results of this study show that ecological management strategies and improved farm hygiene practices can be more effective intervention strategies than antibiotic use, providing valuable insights for sustainable shrimp aquaculture and public health interventions.
Maha M. Rezk, D. Hamza, E. Ismael et al.· Scientific Reports· 0 citations
The present study assessed the population of Vibrio spp. and total heterotrophic bacteria (THB) in a semi-intensive Litopenaeus vannamei culture farm located along the Velankanni coast, Tamil Nadu, India. The investigation was carried out in four culture ponds during two consecutive culture periods, from February 2023 to June 2023 and from August 2023 to December 2023. Water, sediment and shrimp samples were collected on the 1st, 25th, 45th, 65th, 90th, 115th and 140th days of culture. Total heterotrophic bacteria were enumerated using Zobell’s marine agar, whereas Vibrio spp. were enumerated using thiosulphate citrate bile salts sucrose agar. Bacterial loads increased with the progression of culture days in both culture periods, and sediment samples generally recorded higher bacterial counts than water and animal samples. The highest THB counts in water, sediment and shrimp samples were 9.5 × 10⁷ CFU/ml, 4.3 × 10⁸ CFU/g and 9.8 × 10⁵ CFU/g, respectively, all in pond C during the first culture period at 140 DOC. Vibrio spp. also increased with culture duration, with the highest counts recorded in pond C during the first culture period. Pond C showed elevated Vibrio counts and was associated with White Feces Syndrome, reduced survival and lower average body weight. The findings indicate that regular monitoring of bacterial load, particularly Vibrio spp., is important for microbial management in L. vannamei culture ponds.
Vijaya Abraham, V. Indra· Uttar Pradesh Journal of Zoo...· 0 citations
Background:
Vibrio parahaemolyticus and Vibrio cholerae are important foodborne pathogens found in marine shrimp, potentially causing gastrointestinal illness in humans. Diseases caused by these pathogens negatively impact public health, tourism, and Thailand’s seafood-processing industry.
Aim:
This study investigated the occurrence of Vibrio spp. in ready-to-eat raw and cooked shrimp dishes sold in Bangkok, Thailand, with an emphasis on V. parahaemolyticus prevalence, virulence gene carriage, and antimicrobial resistance.
Methods:
Between January and September 2023, 100 shrimp samples were collected from 50 restaurants and 50 street vendors. The shrimp samples (25 g) were enriched in alkaline peptone water and cultured on TCBS agar. The suspected colonies were identified using MALDI-TOF MS. Antimicrobial susceptibility was assessed by disk diffusion, and virulence genes were detected by polymerase chain reaction. Logistic regression analysis was conducted to estimate the odds ratios for Vibrio prevalence by cooking status, food type, and restaurant type.
Results:
V. cholerae was not detected, whereas V. parahaemolyticus was isolated from 18% of the samples. The hemolysin genes tdh and trh were absent from all V. parahaemolyticus isolates. The insecticidal toxin genes pirA and pirB were identified in 3 V. parahaemolyticus isolates. Resistance to ampicillin and cefotaxime was observed in 55.6% and 44.4% of isolates, respectively, whereas all isolates remained susceptible to meropenem. In addition, 88.9% of the isolates were susceptible to ceftazidime, azithromycin, erythromycin, and tetracycline. Logistic regression analysis identified “cooking status” as a significant risk factor: raw shrimp dishes were more than eight times more likely to be contaminated than cooked ones (odds ratio = 8.238, p < 0.05).
Conclusion:
These findings highlight the risk of V. parahaemolyticus contamination in raw shrimp and the antimicrobial resistance of this bacterium. Although neither the tdh nor the trh genes were detected, raw shrimp consumption should be discouraged to minimize exposure to foodborne pathogens and antimicrobial-resistant bacteria.
Pornpawit Tanpichai, S. Semsirmboon, Onanong Charoenwai et al.· Open Veterinary Journal· 0 citations
Fish-borne zoonotic pathogens represent an emerging global public health concern due to increasing seafood consumption, climate change, and the rapid expansion of marine fisheries and aquaculture systems worldwide. The present study investigated the prevalence, molecular detection, and epidemiological characteristics of major zoonotic pathogens among commercially important marine fish species collected from the Gulf of Aqaba, Jordan. A total of 300 marine fish samples representing six commercially important fish species were collected between January and May 2026 from three coastal landing sites. Samples were screened for Vibrio spp., Anisakis larvae, and Mycobacterium marinum using microbiological, parasitological, and polymerase chain reaction (PCR)-based molecular techniques targeting the toxR and hsp65 genes. The overall prevalence of zoonotic pathogens was 27.3% (82/300). Vibrio spp. exhibited the highest prevalence (18.0%), followed by Anisakis larvae (7.7%) and M. marinum (4.3%). Significant differences were observed among fish species and sampling locations (p < 0.05). Grouper and rabbitfish demonstrated higher pathogen burdens compared with tuna and barracuda species. Molecular assays successfully confirmed the targeted gene sequences in positive isolates. The findings demonstrate the circulation of multiple zoonotic pathogens in marine fish from the Gulf of Aqaba and highlight the importance of molecular surveillance, seafood safety monitoring, and One Health-based preventive strategies. Continuous epidemiological surveillance and public health interventions are necessary to reduce zoonotic transmission risks associated with seafood consumption and occupational exposure.
Montasir Al-Mansi, Majd Amjad al Shatarat, Dana Saleh Alhnaity et al.· Genetics and Molecular Resea...· 0 citations
Vibrio parahaemolyticus is a leading cause of seafood-associated gastroenteritis, yet the ecological and genomic significance of environmental populations as potential reservoirs remains incompletely characterized. From May to October 2024, 108 water samples were collected monthly at one coastal and two estuarine sites in Haiyan, Zhejiang. Confirmed isolates (n = 39) underwent whole-genome sequencing, MLST/cgMLST, virulence and AMR gene screening, integron characterization with BLASTp (+2.17.0) integrase family typing, and viral-region prediction. Culture-based detection was absent in May and rose to 66.7% in October (Cochran–Armitage trend, p = 0.003), with descriptively higher detection at the coastal site. MLST identified 28 STs including four novel types (Simpson’s diversity = 0.953). All isolates lacked tdh, trh, and T3SS2 but retained T3SS1 and MAM7. One estuarine isolate carried CALIN-associated dfrA31 and qnrVC5. All integrases matched VpaIntIA (95.9–100% identity), not mobile class 1–3 integrases. Viral regions were detected in 38/39 isolates; filamentous phage annotations in 52.6%. Haiyan coastal V. parahaemolyticus shows seasonal and spatial patterns, high diversity, and a mobilome dominated by chromosomal super-integrons, underscoring the need for integrase family typing in environmental surveillance.