Characterization of Pathogenic Vibrio parahaemolyticus Isolated From Fish Aquaculture of the Southwest Coastal Area of Bangladesh.

Abu Baker Siddique,Mohammad Rafiqul Islam,Md Nayem Dewan,Mohammed Badrul Amin,Md Shafiqul Islam,Zahid Hayat Mahmud,Anowar Khasru Parvez,Sobur Ali,Dinesh Mondal,M Moniruzzaman

doi:10.3389/fmicb.2021.635539

Abstract

Vibrio parahaemolyticus is a major foodborne pathogen responsible for significant economic losses in aquaculture and a threat to human health. Here, we explored the incidence, virulence potential, and diversity of V. parahaemolyticus isolates from aquaculture farms in Bangladesh. We examined a total of 216 water, sediment, Oreochromis niloticus (tilapia), Labeo rohita (rui), and Penaeus monodon (shrimp) samples from the aquaculture system where 60.2% (130/216) samples were positive for V. parahaemolyticus. Furthermore, we identified 323 V. parahaemolyticus strains from contaminated samples, 17 of which were found positive for trh, a virulence gene. Four isolates out of the 17 obtained were able to accumulate fluid in the rabbit ileal loop assay. The correlation between the contamination of V. parahaemolyticus and environmental factors was determined by Pearson correlation. The temperature and salinity were significantly correlated (positive) with the incidence of V. parahaemolyticus. Most of the pathogenic isolates (94.1%) were found resistant to ampicillin and amoxicillin. O8: KUT was the predominant serotype of the potentially pathogenic isolates. ERIC-PCR reveals genetic variation and relatedness among the pathogenic isolates. Therefore, this region-specific study establishes the incidence of potential infection with V. parahaemolyticus from the consumption of tilapia, rui, and shrimp raised in farms in Satkhira, Bangladesh, and the basis for developing strategies to reduce the risk for diseases and economic burden.

Highlights

The Gram-negative, facultative anaerobic bacterium Vibrio parahaemolyticus is usually present in tropical and temperate coastal waters, as well as in shrimp aquaculture (Heredia et al, 2009)
Water and sediment samples were taken from three different spots of each site, and three pieces of each category of fishes were picked up in every sampling time to cover the maximum areas of the site according to the American Public Health Association (APHA) (Federation and American Public Health Association, 2005)
A bacterial suspension with turbidity comparable to 0.5 McFarland standard was made from bacterial inocula taken from overnight cultured Gelatin Agar (GA) plate and swabbed onto the Mueller-Hinton Agar (MHA) (Difco Detroit, MI, United States)

Summary

INTRODUCTION

The Gram-negative, facultative anaerobic bacterium Vibrio parahaemolyticus is usually present in tropical and temperate coastal waters, as well as in shrimp aquaculture (Heredia et al, 2009). Vibrio-related infections caused by V. parahaemolyticus, which eventually turn into an epidemic, have been observed in Asia, Europe, the United States, Peru, and Chile in the past few decades. These outbreaks were linked with rare, gradual seawater temperature rises along the shoreline (Velazquez-Roman et al, 2014). Several studies performed worldwide implicate environmental factors such as turbidity, temperature, water salinity, amounts of organic matter, and suspended chlorophyll, among others, in the distribution of V. parahaemolyticus and the abundance of the species (López-Hernández et al, 2015). Substantial interest has been grown in understanding the biotic and abiotic factors of V. parahaemolyticus Such data has value for estimating the properties and abundance of the species in aquaculture. Pathogenic strains were further characterized to determine their virulence potential in a rabbit model

MATERIALS AND METHODS

RESULTS

DISCUSSION

ETHICS STATEMENT