TY  - GEN
T1  - Pathological, genomic and phenotypical characterization of Vibrio parahaemolyticus, causative agent of acute hepatopancreatic necrosis disease (AHPND) in Mexico
A1  - Lozano-Olvera, R.
LA  - English
YR  - 2021
UL  - http://discoverylib.upm.edu.my/discovery/Record/oai:http:--agris.upm.edu.my:0-19686
AB  - Moribund whiteleg shrimp (Penaeus vannamei) affected by acute hepatopancreatic necrosis disease (AHPND) from farms in northwestern Mexico were sampled for pathological analysis. Bacterial isolates were molecularly identified as Vibrio parahaemolyticus (VP) by the presence of the tlh gene. The tdh-negative, trh-negative and tlh-positive VP strains were further characterized by enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR). The VP pure strains were used in immersion challenges with shrimp, and farmed and challenged shrimp presented the same clinical and pathological signs: lethargy, empty gut, pale and aqueous hepatopancreas and expanded chromatophores. Using fresh mount, histological analysis and bacterial density count, three stages of AHNPD (initial, acute and terminal) were identified in the affected shrimp. Pathognomonic lesions indicated severe desquamation of tubular epithelial cells of the hepatopancreas. VP had different virulence and was dose dependent. VP strains showed wide tolerance to different environment conditions of temperature, salinity and pH, and pathogenic and non-pathogenic VP strains from Mexico had similar morphological and physiological characteristics but pathogenic VP strains were most sensitive to nalidixic acid and showed resistance to penicillin. Whole genomic sequence of 22 VP strains from Asia, Mexico and South America shows the presence of similar chromosomic pathogenic mechanisms, and comparative analysis by multilocus sequence analysis (MLSA) of seven genes clearly showed that most of the isolates are independent strains.
KW  - Prawns and shrimps
KW  - Penaeus vannamei
KW  - Animal pathology
KW  - Isolation of microorganisms
KW  - Vibrio parahaemolyticus
KW  - Vibrio
KW  - Bacteria
KW  - Bacterial diseases
KW  - Genes
KW  - Bacterial counting
KW  - Virulence
KW  - Dosage
KW  - Histopathology
KW  - Antimicrobial resistance
ER  -