Detection of WSSV in cultured shrimps, captured brooders, shrimp postlarvae and water samples in Bangladesh by PCR using different primers

摘要

Detection of whitespot syndrome virus (WSSV) in cultured shrimps (Penaeus monodon), P. monodon brooders, shrimp postlarvae and water samples in Bangladesh was carried out by Polymerase chain reaction (PCR) using five different pairs of primers yielding amplicons ranging from 3 10 to 23 10 bp. The primer pairs used in this study are designated as KF 1 - 2 (2310 bp), Lo 1 - 2 (1447 bp), Lo 5 - 6 (775 bp), IK 1 - 2 (486 bp) and IK 3 - 4 (310 bp). Out of 42 cultured shrimp tested, 36 were positive for WSSV, with 18 by non-nested reaction and 18 by nested reaction. In non-nested reaction only one shrimp sample showed positive for WSSV with all the five primer pairs, four showed positive with primer pairs Lo 1 - 2, Lo 5 - 6, IK 1 - 2 and IK 3 - 4, two showed positive with primer pairs Lo 5 - 6, IK 1 - 2 and IK 3 - 4, 2 positive with primer pairs IK 1 - 2 and IK 3 - 4 and nine showed positive with primer pairs IK 3 - 4 only. In nested reaction all the 18 samples showed positive with primer pairs M 1 - 2 and IK 3 - 4. All the five brooders were positive for WSSV by non-nested PCR with primers IK 3 - 4 and only one was positive by primers yielding higher fragments. Out of 18 post larvae tested, two were positive by nested reaction using IK 1 - 2 and IK 3 - 4. Among 12 water samples analysed, three showed positive in non-nested reaction with primers IK 3 - 4 only and five showed positive in nested reaction with primers IK 1 - 2 and IK 3 - 4. All the PCR products were further confirmed by dot blot hybridization using biotinylated probe.