Bacteriology and Infectious Diseases

Biography

Biography: Nadia Mukhtar

Abstract

Neonatal calf diarrhea and subsequent mortality is one of the main economic losses associated to dairy industry particularly in developing countries like Pakistan. Among infectious agents,rotavirus is the major one. Fecal samples(n=200)from cattle and buffalocalves suffering from diarrhea(n=100each)and of age<3 months were taken aseptically from dairy populated districts of Punjab province and processed for detection of rotavirus thorough commercially available ELISA kit. Out of 200diarrheic fecal samples, a total of 12samples;5cattle calves and 7buffalo calves were found positive after processing. Among these,3cattle calves and5buffalo calves were from Lahore district while 2cattle calves and 2buffalo calves were from Faisalabad district. When the virus was switched to MDBKcellline a remarkable difference in the CPEs was observed and after 9successive passages the titer of the virus was 1×108.5TCID50/ml. The onset of diarrhea was delayed and decrease in severity was observed in the calves that had been fed with colostrum that contained high concentrations of antibody to the bovine rotavirus. The average antibody titers in 25cattle dams at 0,14,28and42days post vaccination were 0%,57%,68%and78% respectively. The average antibody titers in 25buffalo dams at0,14,28and42days-post-vaccination were 0%,55%,70%and82%respectively. These results indicate the protective maternal antibody level against rotavirus were developed which will be transferred passively to calves. The challenge study using same live rotavirus strain reveals protection among calves from vaccinated dams while calves from unvaccinated dams showed mild to severe diarrhea The vaccine efficacy findings led to a strategy of vaccinating dams shortly before delivery, to boost levels of RV-specific antibody in colostrum. It is to be noted that the dose and timing are integral to the success of this mode of vaccination.