Molecular Characterization of Avian Infectious Bronchitis Virus Isolated in Malaysia during 2014-2016.

Avian Infectious Bronchitis (IB) is a highly contagious disease which can cause huge economic losses to the poultry industry. Forty five IB viruses (IBV) were isolated from poultry in Malaysia during 2014-2016. Phylogenetic analysis of the spike glycoprotein 1 (S1) gene revealed that all isolates were clustered into five distinct groups. The predominant type of IBV isolated was QX strains (47%), second was 4/91 type (27%), followed by Malaysian strain MH5365/95 (13%), Massachusetts type (11%) and finally Taiwanese strains (2%). Four types of S1 protein cleavage recognition motifs were found among the isolates which includes HRRRR, RRSRR, RRFRR and RRVRR. To our knowledge, this is the first report describing the motif RRVRR and are unique to Malaysian strains. Six IBVs were grouped in Malaysian MH5365/95 strains. Among these, one isolate was different from others where it only shared 82% identity with MH5365/95 and to others. It formed its own branch in the Malaysian cluster suggesting it may be a variant unique to Malaysia. Alignment analysis of the S1 amino acid sequences indicated that point mutations, insertions and deletions contribute to the divergence of IB variants. This study indicated at least five groups of IBV are circulating in Malaysia with most of the isolates belonged to QX strains. As new IBV variants continue to emerge, further study need to be carried out to determine whether the current available vaccine is able to give protection against the circulating virus.

Evidence for Nipah virus recrudescence and serological patterns of captive Pteropus vampyrus.

This study aimed to describe the transmission dynamics, the serological and virus excretion patterns of Nipah virus (NiV) in Pteropus vampyrus bats. Bats in captivity were sampled every 7-21 days over a 1-year period. The data revealed five NiV serological patterns categorized as high and low positives, waning, decreasing and increasing, and negative in these individuals. The findings strongly suggest that NiV circulates in wild bat populations and that antibody could be maintained for long periods. The study also found that pup and juvenile bats from seropositive dams tested seropositive, indicating that maternal antibodies against NiV are transmitted passively, and in this study population may last up to 14 months. NiV was isolated from the urine of one bat, and within a few weeks, two other seronegative bats seroconverted. Based on the temporal cluster of seroconversion, we strongly believe that the NiV isolated was recrudesced and then transmitted horizontally between bats during the study period.

Ketamine and xylazine combinations for short-term immobilization of wild variable flying foxes (Pteropus hypomelanus).

Collection of biological samples from pteropid bats requires chemical restraint of the bats to minimize risks to humans and stress to the bat. The effectiveness of an intravenous combination of ketamine and xylazine for short-term restraint of wild-caught variable flying foxes (Pteropus hypomelanus) in a field situation was evaluated. Eight adult male variable flying foxes were injected intravenously with 0.1 ml of ketamine and xylaxine containing 5 mg of ketamine and 1 mg of xylazine. The mean induction time was 80 +/- 20 sec, and mean immobilization time was 26 +/- 10 min. The ketamine-xylazine combination used in this study produced effective short-term immobilization of wild variable flying foxes for the collection of biological samples.