Antibiotic resistance and plasmid profiling of Vibrio parahaemolyticus isolated from shrimp farms along the southwest coast of India

High consumer demand for seafood has led to the need for large-scale, reliable supply through aquaculture farming. However, bacterial infections - which can spread rapidly among the dense farming area pose a major threat to this industry. The farmers therefore often resort to extensive use of antibiotics, both prophylactically and therapeutically, in order to protect their stocks. The extensive use of antibiotics in aquaculture has been postulated to represent a major contributing factor in the rising incidence of antimicrobial resistant pathogenic bacteria in seafood; which may then lead to the spread of antimicrobial resistant bacteria in the environment as well as posing a significant threat to human health. This study aimed to characterize antibiotic resistance of Vibrio parahaemolyticus from shrimp and shellfish in Selangor, Malaysia. The antibiotic susceptibility of 385 V. parahaemolyticus isolates was investigated against 14 antibiotics followed by plasmid profiling and plasmid curing to determine the antibiotic mediation. A large number of isolates showed resistance to ampicillin (85%), amikacin (66.8%), and kanamycin (50.1%). A notable resistance pattern was also observed to the third generation cephalosporins (cefotaxime 55.8% and ceftazidime 34%). Only 338 V. parahaemolyticus isolates had 1-7 different plasmids and could be categorized into 27 patterns based on the number and pattern of plasmid present. Interestingly, there was no correlation between the number of plasmids and antibiotic resistant patterns seen in the isolates. The antibiotic resistance was mediated by both chromosomal and plasmid mediation among the resistant isolates. In summary, our results demonstrate that incidence of pathogenic V. parahaemolyticus in seafood in Selangor remains in relatively assuring levels, however the identification of antibiotic resistance among the isolates does rises a public health concern and warrants for continuous surveillance.

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Detection and molecular characterization of Vibrio parahaemolyticus isolated from seafood harvested along the southwest coast of India

Food Microbiology ◽

10.1016/j.fm.2008.04.002 ◽

2008 ◽

Vol 25 (6) ◽

pp. 824-830 ◽

Cited By ~ 39

Author(s):

P RAGHUNATH ◽

S ACHARYA ◽

A BHANUMATHI ◽

I KARUNASAGAR ◽

I KARUNASAGAR

Keyword(s):

Molecular Characterization ◽

Vibrio Parahaemolyticus ◽

Southwest Coast Of India ◽

Southwest Coast

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Seasonal Variation in Abundance of Total and Pathogenic Vibrio parahaemolyticus Bacteria in Oysters along the Southwest Coast of India

Applied and Environmental Microbiology ◽

10.1128/aem.71.7.3575-3580.2005 ◽

2005 ◽

Vol 71 (7) ◽

pp. 3575-3580 ◽

Cited By ~ 116

Author(s):

A. Deepanjali ◽

H. Sanath Kumar ◽

I. Karunasagar ◽

I. Karunasagar

Keyword(s):

Vibrio Parahaemolyticus ◽

Pcr Amplification ◽

Seasonal Abundance ◽

Southwest Coast Of India ◽

Colony Hybridization ◽

Southwest Coast ◽

Alkaline Peptone Water ◽

Pathogenic Vibrio ◽

Hemolysin Gene ◽

Peptone Water

ABSTRACT The seasonal abundance of Vibrio parahaemolyticus in oysters from two estuaries along the southwest coast of India was studied by colony hybridization using nonradioactive labeled oligonucleotide probes. The density of total V. parahaemolyticus bacteria was determined using a probe binding to the tlh (thermolabile hemolysin) gene, and the density of pathogenic V. parahaemolyticus bacteria was determined by using a probe binding to the tdh (thermostable direct hemolysin) gene. Furthermore, the prevalence of V. parahaemolyticus was studied by PCR amplification of the toxR, tdh, and trh genes. PCR was performed directly with oyster homogenates and also following enrichment in alkaline peptone water for 6 and 18 h. V. parahaemolyticus was detected in 93.87% of the samples, and the densities ranged from <10 to 104 organisms per g. Pathogenic V. parahaemolyticus could be detected in 5 of 49 samples (10.2%) by colony hybridization using the tdh probe and in 3 of 49 samples (6.1%) by PCR. Isolates from one of the samples belonged to the pandemic serotype O3:K6. Twenty-nine of the 49 samples analyzed (59.3%) were positive as determined by PCR for the presence of the trh gene in the enrichment broth media. trh-positive V. parahaemolyticus was frequently found in oysters from India.

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