Molecular diagnostic approaches for haemorrhagicsepticaemia (HS): A review

Abstract

Haemorrhagic septicaemia (HS), a major bacterial disease of economic significance affecting cattle and buffaloes in India, is known to be caused by Gram - negative bacterium Pasteurella multocida strains. Conventionally, disease diagnosis is based on clinical signs and laboratory methods involving isolation and characterisation of causative agent. In view of limitations of conventional approaches, in recent times, DNA - based assays are increasingly being employed for rapid and specific detection of bacterium. This review brings comprehensive information on DNAbased rapid detection methods [P. multocida - specific polymerase chain reaction (PM - PCR), haemorrhagic serogroup - B - specific(HSB) - PCR, Multiplex Capsular typing, Real - Time PCR, loop - mediated isothermal amplification] and typing tools [restriction endonuclease analysis (REA), pulsed - field gel electrophoresis, randomly amplified polymorphic DNA (RAPD)/repetitive extragenic palindromic (REP)/enterobacterial repetitive intergenic consensus (ERIC) - PCR, ribotyping, amplified fragment length polymorphism, multilocus sequence typing, sequencing] with their suitability for epidemiological studies of HS outbreaks. It is suggested to employ PM/HSB - PCR assays directly on clinical materials for rapid detection and typing tools such as REA and REP - PCR/ERIC - PCR, could be employed in parallel to conventional methods of bacterial isolation and characterisation, for rapid investigation and differentiation of P. multocida isolates causing HS outbreaks in various geographical regions of India.