Strain Variations in Monodon Baculovirus (mbv) Infecting Penaeus Monodon (tiger Shrimp) in India

Viral diseases are the most serious problem in shrimp culture as they result in severe production and economic losses. Monodon baculovirus (MBV) is a member of nucleopolyhedrosis virus (NPV) group that infect penaeid shrimps. Polymerase chain reaction (PCR) assays have been reported for specific and accurate detection of MBV. As variations in the strains of MBV would greatly affect the detection efficiency of PCR assays, the objective of this study was to understand the existence of strain variations in MBV infecting Penaeus monodon in India. Shrimp samples collected from the shrimp farms and hatcheries of India during the period from March 2004 to March 2012 were screened for MBV infection by wet mount squash method and PCR. MBV infected samples collected during different years and from different sources were used to study the strain variations by PCR amplification of polyhedrin gene. Nucleotide sequencing and aminoacid analyses showed that the isolate, MBV9/ SDDL/04 was distinctly different among the nine isolates obtained from shrimp samples which confirmed the existence of variation in the strains of MBV in India.