Evaluation of the pathogenesis of non-typical strain with α-hemolysin, Vibrio parahaemolyticus 353, isolated from Chinese seafood through comparative genome and transcriptome analysis

Antimicrobial susceptibility and genomic characterization of Vibrio parahaemolyticus isolated from aquatic foods in 15 provinces, China, 2020

Prevalent in marine, estuarine and coastal environments, Vibrio parahaemolyticus is one of the major foodborne pathogens which can cause acute gastroenteritis through consumption of contaminated food. This study encompassed antimicrobial resistance, molecular characteristics and phylogenetic relationships of 163 V. parahaemolyticus isolated from aquatic foods across 15 provinces in China. The isolates showed high resistance rates against ampicillin (90.80 %, 148/163) and cefazolin (72.39 %, 118/163). Only 5 isolates demonstrated multi-drug resistance (MDR) phenotypes. A total of 37 different antibiotic resistance genes (ARGs) in correlation with seven antimicrobial categories were identified. tet(34) and tet(35) were present in all 163 isolates. Other most prevalent ARGs were those conferring resistance to β-lactams, with prevalence rate around 18.40 % (30/163). The virulence genes tdh and trh were found in 17 (10.43 %) and 9 (5.52 %) isolates, respectively. Totally 121 sequence types (STs) were identified through whole genome analysis, among which 60 were novel. The most prevalent sequence type was ST3 (9.20 %, 15/163), which shared the same genotype profile of trh_, tdh+ and blaCARB-22+. Most of the tdh+V. parahaemolyticus isolates was clustered into a distinctive clade by the phylogenetic analysis. Our study showed that the antimicrobial resistance of V. parahaemolyticus in aquatic foods in China was moderate. However, the emerging of MDR isolates implicate strengthened monitoring is needed for the better treatment of human V. parahaemolyticus infections. High genetic diversity and virulence potential of the isolates analyzed in this study help better understanding and evaluating the risk of V. parahaemolyticus posed to public health.

Sources and contamination routes of seafood with human pathogenic Vibrio spp.: A Farm-to-Fork approach

Vibrio spp., known human foodborne pathogens, thrive in freshwater, estuaries, and marine settings, causing vibriosis upon ingestion. The rising global vibriosis cases due to climate change necessitate a deeper understanding of Vibrio epidemiology and human transmission. This review delves into Vibrio contamination in seafood, scrutinizing its sources and pathways. We comprehensively assess the contamination of human-pathogenic Vibrio in the seafood chain, covering raw materials to processed products. A "Farm-to-Fork" approach, aligned with the One Health concept, is essential for grasping the complex nature of Vibrio contamination. Vibrio's widespread presence in natural and farmed aquatic environments establishes them as potential entry points into the seafood chain. Environmental factors, including climate, human activities, and wildlife, influence contamination sources and routes, underscoring the need to understand the origin and transmission of pathogens in raw seafood. Once within the seafood chain, the formation of protective biofilms on various surfaces in production and processing poses significant food safety risks, necessitating proper cleaning and disinfection to prevent microbial residue. In addition, inadequate seafood handling, from inappropriate processing procedures to cross-contamination via pests or seafood handlers, significantly contributes to Vibrio food contamination, thus warranting attention to reduce risks. Information presented here support the imperative for proactive measures, robust research, and interdisciplinary collaboration in order to effectively mitigate the risks posed by human pathogenic Vibrio contamination, safeguarding public health and global food security. This review serves as a crucial resource for researchers, industrials, and policymakers, equipping them with the knowledge to develop biosecurity measures associated with Vibrio-contaminated seafood.

Incidence, virulence genes and antimicrobial resistance of Vibrio parahaemolyticus isolated from seafood

The objective of the study was to establish the incidence, pathogenic factors and antimicrobial resistance of Vibrio parahaemolyticus in seafood from retail shops in Bulgaria. A hundred and eighty samples of sea fish, mussels, oysters, veined rapa whelks, shrimps and squids were included in the study. PCR methods were used to identify V. parahaemolyticus and prove tdh and trh genes. Antimicrobial resistance was established by disc diffusion method, and MAR index was calculated. The results proved the presence of V. parahaemolyticus in 24% (44/180) of the seafood samples. tdh-positive V. parahaemolyticus was not found, while the trh gene was detected in one veined rapa whelk isolate. All isolates were susceptible to Sulfamethoxazole/trimethoprim, Tetracycline, Gentamycin, Amoxicillin-clavulanic acid, Amikacin, Ciprofloxacin, and Levofloxacin. Intermediate resistance was found to Ampicillin (25%; 11/44), Cefepime (16%; 7/44), and Ceftazidime (2%; 1/44). The results showed that 16% (7/44) of the isolates were resistant to Cefepime, 9% (4/44) to Ampicillin, and 5% (2/44) to Ceftazidime. MAR-index values ranged from 0.10 to 0.30. The incidence of pathogenic and multidrug-resistant V. parahaemolyticus strains in seafood offered on the market poses a risk to consumer health.