We isolated and characterized Nipah virus (NiV) from Pteropus vampyrus bats, the putative reservoir for the 1998 outbreak in Malaysia, and provide evidence of viral recrudescence. This isolate is monophyletic with previous NiVs in combined analysis, and the nucleocapsid gene phylogeny suggests that similar strains of NiV are co-circulating in sympatric reservoir species.

Newcastle disease virus (NDV) is a contagious viral disease of many avian species particularly domestic poultry, and is responsible for causing significant economic losses to the poultry industry in Southeast Asia including Malaysia. Here we report the sequence and phylogenetic analysis of NDV that has been circulating in Malaysia. A total of 151 NDV isolates were selected during 1999-2012 throughout Malaysia and were characterized phylogenetically. The partial region of matrix (M) and fusion (F) protein of NDV was amplified by reverse transcriptase PCR, directly sequenced and compared genetically to the published sequences obtained from GenBank. The deduced amino acid sequence of the F protein cleavage site revealed the presence of three different motifs; 112RRRKRF117, 112RRQKRF117 typical for velogenic strains while 112GKQGRL117 indicates it is from avirulent strain or lentogenic strain. The phylogenetic analysis revealed that 13 isolates belonged to genotype I, 2 to genotype III, 6 to genotype VI, 1 to genotype VIII and 129 to genotype VII. Isolates belonging to genotype VII were further divided into five subgenotypes; VIIa, VIIb, VIId, VIIe and VIIh. Based on the phylogenetic tree and geographical data, it is found that NDV genotype VIIb and VIIe were isolated in 1999 while in year 2000 to 2009, most of the NDV isolates were NDV genotype VIId originated from China. No subgenotype VIId viruses were recovered after 2009 in Malaysia. In 2010-2012, NDV outbreaks were caused by subgenotypes VIIa and VIIh in Peninsular Malaysia. Interestingly, these subgenotypes have been isolated in East Malaysia since 2002 but did not cause major outbreak.  These information points to the existence of multiple genotypes of NDV in Malaysia especially genotype VII and these findings emphasize the importance of continuous surveillance of NDV in Malaysia.

No abstract

The emergence of avian diseases can cause major economic problems due to production losses and mortality in domestic poultry. Astrovirus is frequently associated with enteric diseases in poultry, being isolated from cases of runting-stunting syndrome (RSS) of broiler chickens, poult enteritis complex (PEC), and poult enteritis mortality syndrome (PEMS) of turkeys. Avian astrovirus can be detected in chickens from both healthy and poorly performing flocks. In Malaysia, information and reports regarding chicken astrovirus (CAstV) in poultry are limited. The objective of this study is to perform a phylogenetic study on the avian astrovirus isolated from a suspected case in 2019 and to determine the subgroups of avian astrovirus strains that existed in Malaysia. Reverse Transcription Polymerase chain reaction (RT-PCR) was performed based on the partial ORF1b gene and the nucleotide sequence was analyzed. Phylogenetic analysis showed that this isolate was clustered together with CAstV strains from several strain from USA, Malaysia and others. Furthermore, the isolate from broiler chicken showed 97.2% to 99.4% of its nucleotide identity with isolates from the American strains, compared to the previously CAstv Malaysia strain, which shared 94.8% to 95%.Therefore, the current study provides important information on the epidemiology of CAstV and highlights the importance of control strategies against CAstV-infected poultry in Malaysia.

The effectiveness of the new inactivated vaccine develop from local velogenic strain of Newcastle disease virus (NDV) Genotype VII and commercial vaccines LaSota were compared by determining the immune response and virus shedding of vaccinated chickens. Ten different groups of chicken consists of ten each, were vaccinated with and without adjuvant of the inactivated vaccine via intramuscular and subcutaneous, respectively. Three different adjuvants were used which include Oil-emulsion Complete Freund’s, Oil-emulsion Squalene-based, and aluminium hydroxide gel (Alum). As a comparison, a group of chicken was vaccinated with commercial vaccine and control group was not vaccinated. With 100% survival rate and highest mean haemaglutination-inhibition (HI) titre of log2 6, the inactivated vaccine with adjuvant Alum and Oil-emulsion Complete Freund’s surpassed the LaSota. In addition, the virus shedding was significantly reduced and comparable to LaSota vaccinated chicken. Whereas, without adjuvant, the chicken HI antibody titre is below log2 4 after vaccination and only 20-30% were survived. Based on the post-mortem findings on the survived chicken from each vaccinated group, their internal organs appeared normal and no sign of haemorrhage or pathognomonic signs of Newcastle disease (ND). Conclusively, vaccinated chicken are effectively protected from morbidity and mortality against virulent genotype VII challenge with the addition of adjuvant into inactivated local strain of NDV genotype VII vaccine. Thus, the development of inactivated local NDV genotype VII vaccine is a promising candidate to control the current ND endemic in Malaysia.