Prevalence and antimicrobial resistance of food safety related Vibrio species in inland saline water shrimp culture farms / Prevalencia y resistencia a los antimicrobianos de especies de Vibrio relacionadas con la inocuidad de los alimentos en granjas de cultivo de camarones de aguas saladas continentales

This study evaluated the potential pathogenicity and antimicrobial resistance (AMR) of Vibrio species isolated from inland saline shrimp culture farms. Out of 200 Vibrio isolates obtained from 166 shrimp/water samples, 105 isolates were identified as V. parahaemolyticus and 31 isolates were identified as V. alginolyticus and V. cholerae, respectively. During PCR screening of virulence-associated genes, the presence of the tlh gene was confirmed in 70 and 19 isolates of V. parahaemolyticus and V. alginolyticus, respectively. Besides, 10 isolates of V. parahaemolyticus were also found positive for trh gene. During antibiotic susceptibility testing (AST), very high resistance to cefotaxime (93.0%), amoxiclav (90.3%), ampicillin (88.2%), and ceftazidime (73.7%) was observed in all Vibrio species. Multiple antibiotic resistance (MAR) index values of Vibrio isolates ranged from 0.00 to 0.75, with 90.1% of isolates showing resistance to ≥ 3 antibiotics. The AST and MAR patterns did not significantly vary sample-wise or Vibrio species-wise. During the minimum inhibitory concentration (MIC) testing of various antibiotics against Vibrio isolates, the highest MIC values were recorded for amoxiclav followed by kanamycin. These results indicated that multi-drug resistant Vibrio species could act as the reservoirs of antibiotic resistance genes in the shrimp culture environment. The limited host range of 12 previously isolated V. parahaemolyticus phages against V. parahaemolyticus isolates from this study indicated that multiple strains of V. parahaemolyticus were prevalent in inland saline shrimp culture farms. The findings of the current study emphasize that routine monitoring of emerging aquaculture areas is critical for AMR pathogen risk assessment.(AU)

Prevalence and antimicrobial resistance of food safety related Vibrio species in inland saline water shrimp culture farms.

This study evaluated the potential pathogenicity and antimicrobial resistance (AMR) of Vibrio species isolated from inland saline shrimp culture farms. Out of 200 Vibrio isolates obtained from 166 shrimp/water samples, 105 isolates were identified as V. parahaemolyticus and 31 isolates were identified as V. alginolyticus and V. cholerae, respectively. During PCR screening of virulence-associated genes, the presence of the tlh gene was confirmed in 70 and 19 isolates of V. parahaemolyticus and V. alginolyticus, respectively. Besides, 10 isolates of V. parahaemolyticus were also found positive for trh gene. During antibiotic susceptibility testing (AST), very high resistance to cefotaxime (93.0%), amoxiclav (90.3%), ampicillin (88.2%), and ceftazidime (73.7%) was observed in all Vibrio species. Multiple antibiotic resistance (MAR) index values of Vibrio isolates ranged from 0.00 to 0.75, with 90.1% of isolates showing resistance to ≥ 3 antibiotics. The AST and MAR patterns did not significantly vary sample-wise or Vibrio species-wise. During the minimum inhibitory concentration (MIC) testing of various antibiotics against Vibrio isolates, the highest MIC values were recorded for amoxiclav followed by kanamycin. These results indicated that multi-drug resistant Vibrio species could act as the reservoirs of antibiotic resistance genes in the shrimp culture environment. The limited host range of 12 previously isolated V. parahaemolyticus phages against V. parahaemolyticus isolates from this study indicated that multiple strains of V. parahaemolyticus were prevalent in inland saline shrimp culture farms. The findings of the current study emphasize that routine monitoring of emerging aquaculture areas is critical for AMR pathogen risk assessment.

Complete genome sequencing and characterization of single-stranded DNA Vibrio parahaemolyticus phage from inland saline aquaculture environment.

Despite their evolutionary, molecular biology and biotechnological significance, relatively fewer numbers of single-stranded DNA (ssDNA) filamentous phages belonging to the family Inoviridae have been discovered and characterized to date. The present study focused on genome sequencing and characterization of an ssDNA Vibrio parahaemolyticus phage V5 previously isolated from an inland saline shrimp culture farm. The complete circular genome of phage V5 consisted of 6658 bp with GC content of 43.7%. During BLASTn analysis, only 36% of phage V5 genome matched with other Vibrio phage genomes in the NCBI database with a sequence identity value of 79%. During the phylogenetic analysis, phage V5 formed a separate branch in the minor clade. These features indicate the novel nature of the phage V5 genome. Among 10 predicted open reading frames (ORFs) in the phage V5 genome, 6 encoded for the proteins of known biological functions, whereas the rest were classified as hypotheticals. Proteins involved in replication and structural assembly were encoded by the phage genome. However, the absence of genes encoding for DNA/RNA polymerases and tRNAs signified that phage V5 is dependent on the host`s molecular machinery for its propagation. As per our knowledge, this is the first study describing the novel genome sequence of an ssDNA V. parahaemolyticus phage from the inland saline environment.