Impact of Parasitism on Levels of Human‐Pathogenic Vibrio Species in Eastern Oysters

World-wide increases in Vibrio-associated diseases have been reported in aquaculture and humans in co-occurrence with increased sea surface temperatures. Twelve species of Vibrio are known to cause disease in humans, but three species dominate the number of human infections world-wide: Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio vulnificus. Fluorescent protein (FP)-labelled bacteria have been used to make great progress through in situ studies of bacterial behavior in mixed cultures or within host tissues. Currently, FP-labelling methods specific for Vibrio species are still limited by time-consuming counterselection measures that require the use of modified media and temperatures below the optimal growth temperature of many Vibrio species. Within this study, we used a previously reported R6K-based suicide delivery vector and two newly constructed transposon variants to develop a tailored protocol for FP-labelling V. cholerae, V. parahaemolyticus, and V. vulnificus environmental isolates within two days of counterselection against the donor Escherichiacoli. This herein presented protocol worked universally across all tested strains (30) with a conjugation efficiency of at least two transconjugants per 10,000 recipients.

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The Impact of Water Intrusion on Pathogenic Vibrio Species to Inland Brackish Waters of China

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17186781 ◽

2020 ◽

Vol 17 (18) ◽

pp. 6781

Author(s):

Qingyao Wang ◽

Songzhe Fu ◽

Qian Yang ◽

Jingwei Hao ◽

Can Zhou ◽

...

Keyword(s):

Seawater Intrusion ◽

Water Area ◽

Vibrio Species ◽

Most Probable Number ◽

Potential Health ◽

Probable Number ◽

Inland River ◽

Pathogenic Vibrio ◽

The Impact ◽

Vibrio Spp

The estuary is the ecological niche of pathogenic Vibrio spp. as it provides abundant organic and inorganic nutrients from seawater and rivers. However, little is known about the ecology of these Vibrio species in the inland brackish water area. In this study, their co-occurrence and relationships to key environmental constraints (salinity and temperature) in the Hun-Tai River of China were examined using the most probable number polymerase chain reaction (MPN-PCR) approach. We hereby report 2-year continuous surveillance based on six water indices of the Hun-Tai River. The results showed that seawater intrusion maximally reached inland as far as 26.5 km for the Hun-Tai River. Pathogenic Vibrio spp. were detected in 21.9% of the water samples. In particular, V. cholerae, V. parahaemolyticus, and V. vulnificus were isolated in 10 (10.4%), 20 (20.8.5%), and 2 (2.08%) samples, respectively. All V. parahaemolyticus strains were tdh gene negative, 10% were positive for the trh gene. Multi-locus sequence typing (MLST) divided V. parahaemolyticus strains into 12 sequence types (STs) for the Hun-Tai River. Five STs were respectively present in various locations along the Hun-Tai River. The PCR assay for detecting six virulence genes and Vibrio seventh pandemic island I and II revealed three genotypes in 12 V. cholerae isolates. The results of our study showed that seawater intrusion and salinity have profound effects on the distribution of pathogenic Vibrio spp. in the inland river, suggesting a potential health risk associated with the waters of the Hun-Tai River used for irrigation and drinking.

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