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  1. Fulltext Isolation and Metagenomic Identification of Avian Leukosis Virus Associated with Mortality in Broiler Chicken
    Bande F, Arshad SS, Omar AR
    Adv Virol, 2016;2016:9058403.
    PMID: 27597865 DOI: 10.1155/2016/9058403
    Avian leukosis virus (ALV) belongs to the family Retroviridae and causes considerable economic losses to the poultry industry. Following an outbreak associated with high mortality in a broiler flock in northern part of Malaysia, kidney tissues from affected chickens were submitted for virus isolation and identification in chicken embryonated egg and MDCK cells. Evidence of virus growth was indicated by haemorrhage and embryo mortality in egg culture. While viral growth in cell culture was evidenced by the development of cytopathic effects. The isolated virus was purified by sucrose gradient and identified using negative staining transmission electron microscopy. Further confirmation was achieved through next-generation sequencing and nucleotide sequence homology search. Analysis of the viral sequences using the NCBI BLAST tool revealed 99-100% sequence homology with exogenous ALV viral envelope protein. Phylogenetic analysis based on partial envelope sequences showed the Malaysian isolate clustered with Taiwanese and Japanese ALV strains, which were closer to ALV subgroup J, ALV subgroup E, and recombinant A/E isolates. Based on these findings, ALV was concluded to be associated with the present outbreak. It was recommended that further studies should be conducted on the molecular epidemiology and pathogenicity of the identified virus isolate.
  2. Fulltext Molecular detection, phylogenetic analysis, and identification of transcription motifs in feline leukemia virus from naturally infected cats in malaysia
    Bande F, Arshad SS, Hassan L, Zakaria Z
    Vet Med Int, 2014;2014:760961.
    PMID: 25506469 DOI: 10.1155/2014/760961
    A nested PCR assay was used to determine the viral RNA and proviral DNA status of naturally infected cats. Selected samples that were FeLV-positive by PCR were subjected to sequencing, phylogenetic analysis, and motifs search. Of the 39 samples that were positive for FeLV p27 antigen, 87.2% (34/39) were confirmed positive with nested PCR. FeLV proviral DNA was detected in 38 (97.3%) of p27-antigen negative samples. Malaysian FeLV isolates are found to be highly similar with a homology of 91% to 100%. Phylogenetic analysis revealed that Malaysian FeLV isolates divided into two clusters, with a majority (86.2%) sharing similarity with FeLV-K01803 and fewer isolates (13.8%) with FeLV-GM1 strain. Different enhancer motifs including NF-GMa, Krox-20/WT1I-del2, BAF1, AP-2, TBP, TFIIF-beta, TRF, and TFIID are found to occur either in single, duplicate, triplicate, or sets of 5 in different positions within the U3-LTR-gag region. The present result confirms the occurrence of FeLV viral RNA and provirus DNA in naturally infected cats. Malaysian FeLV isolates are highly similar, and a majority of them are closely related to a UK isolate. This study provides the first molecular based information on FeLV in Malaysia. Additionally, different enhancer motifs likely associated with FeLV related pathogenesis have been identified.
  3. Fulltext Pathogenesis and Diagnostic Approaches of Avian Infectious Bronchitis
    Bande F, Arshad SS, Omar AR, Bejo MH, Abubakar MS, Abba Y
    Adv Virol, 2016;2016:4621659.
    PMID: 26955391 DOI: 10.1155/2016/4621659
    Infectious bronchitis (IB) is one of the major economically important poultry diseases distributed worldwide. It is caused by infectious bronchitis virus (IBV) and affects both galliform and nongalliform birds. Its economic impact includes decreased egg production and poor egg quality in layers, stunted growth, poor carcass weight, and mortality in broiler chickens. Although primarily affecting the respiratory tract, IBV demonstrates a wide range of tissues tropism, including the renal and reproductive systems. Thus, disease outcome may be influenced by the organ or tissue involved as well as pathotypes or strain of the infecting virus. Knowledge on the epidemiology of the prevalent IBV strains in a particular region is therefore important to guide control and preventions. Meanwhile previous diagnostic methods such as serology and virus isolations are less sensitive and time consuming, respectively; current methods, such as reverse transcription polymerase chain reaction (RT-PCR), Restriction Fragment Length Polymorphism (RFLP), and sequencing, offer highly sensitive, rapid, and accurate diagnostic results, thus enabling the genotyping of new viral strains within the shortest possible time. This review discusses aspects on pathogenesis and diagnostic methods for IBV infection.
  4. In vitro isolation and molecular identification of reptarenavirus in Malaysia
    Abba Y, Hassim H, Hamzah H, Ibrahim OE, Ilyasu Y, Bande F, et al.
    Virus Genes, 2016 Oct;52(5):640-50.
    PMID: 27142080 DOI: 10.1007/s11262-016-1345-7
    Boid inclusion body disease (BIBD) is a viral disease of boids caused by reptarenavirus. In this study, tissue from naturally infected boid snakes were homogenized and propagated in African Monkey kidney (Vero) and rat embryonic fibroblast (REF) cells. Virus replication was determined by the presence of cytopathic effect, while viral morphology was observed using transmission electron microscopy. Viral RNA was amplified using RT-PCR with primers specific for the L-segment of reptarenavirus; similarly, quantification of viral replication was done using qPCR at 24-144 h postinfection. Viral cytopathology was characterized by cell rounding and detachment in both Vero and REF cells. The viral morphology showed round-to-pleomorphic particles ranging from 105 to 150 nm which had sand-like granules. Sanger sequencing identified four closely associated reptarenavirus species from 15 (37.5 %) of the total samples tested, and these were named as follows: reptarenavirus UPM-MY 01, 02, 03, and 04. These isolates were phylogenetically closely related to the University Helsinki virus (UHV), Boa Arenavirus NL (ROUTV; BAV), and unidentified reptarenavirus L20 (URAV-L20). Comparison of deduced amino acid sequences further confirmed identities to L-protein of UHV, L-polymerase of BAV and RNA-dependent RNA polymerase of URAV-L20. Viral replication in Vero cells increased steadily from 24 to 72 h and peaked at 144 h. This is the first study in South East Asia to isolate and characterize reptarenavirus in boid snakes with BIBD.
  5. Fulltext Breaking the cycle of the COVID-19 transmission: A challenge for Nigeria
    Garba B, Zakaria Z, Salihu MD, Bande F, Saidu B, Bala JA
    J Glob Health, 2020 Dec;10(2):020309.
    PMID: 33110513 DOI: 10.7189/jogh.10.020309
  6. Fulltext Serological evidence of West Nile viral infection in archived swine serum samples from Peninsular Malaysia
    Mohammed MN, Yasmin AR, Noraniza MA, Ramanoon SZ, Arshad SS, Bande F, et al.
    J Vet Sci, 2021 May;22(3):e29.
    PMID: 33908203 DOI: 10.4142/jvs.2021.22.e29
    West Nile virus (WNV), a neurotropic arbovirus, has been detected in mosquitos, birds, wildlife, horses, and humans in Malaysia, but limited information is available on WNV infection in Malaysian pigs. We tested 80 archived swine serum samples for the presence of WNV antibody and West Nile (WN) viral RNA using ID Screen West Nile Competition Multi-species enzyme-linked immunosorbent assay kits and WNV-specific primers in reverse transcription polymerase chain reaction assays, respectively. A WNV seroprevalence of 62.5% (50/80) at 95% confidence interval (51.6%-72.3%) was recorded, with a significantly higher seroprevalence among young pigs (weaner and grower) and pigs from south Malaysia. One sample was positive for Japanese encephalitis virus antibodies; WN viral RNA was not detected in any of the serum samples.
  7. Fulltext Molecular Characterization and Phylogenetic Analysis of Listeria monocytogenes Isolated from Milk and Milk Products in Kaduna, Nigeria
    Usman UB, Kwaga JK, Kabir J, Olonitola OS, Radu S, Bande F
    Can J Infect Dis Med Microbiol, 2016;2016:4313827.
    PMID: 27597873 DOI: 10.1155/2016/4313827
    In this study, Listeria (L.) monocytogenes isolated from milk and milk products in Kaduna, Nigeria, were subjected to a multiplex PCR assay to identify virulence-associated genes (such as prf A, inl A, hly A, act A, and iap). Of the 36 isolates, 9 (25%) were positive for one or two virulence-associated genes. Based on the sample type, 6 (16.9%) of the isolates that possessed virulence-associated genes were obtained from raw milk, 2 (3.2%) from "Manshanu," and 1 (2.8%) from "Kindrimo." Sequence and phylogenetic analysis based on the 16S rRNA revealed that Nigerian L. monocytogenes isolates (NGA 34A, NGA 35A, NGA 41A, and NGA 38A), when compared with reference L. monocytogenes, were grouped into two distinct clusters, A and B, with sequence (NGA 34A, NGA 35A, and NGA 41A) phylogenetically closer to J1776; N1-011A; R2-502; J1816; and J2-031, whereas L. monocytogenes isolate (NGA 38A) clustered with EDG; J1-220; J1926; J1817; and J2-1091. The separation of the Nigerian L. monocytogenes isolates into linage A (responsible for epidemic listeriosis) and lineage B (responsible for sporadic cases of listeriosis) is of public health concern and that local isolates might have potentials for human food borne listeriosis based on the virulence factors so far identified.
  8. Fulltext Prediction and In Silico Identification of Novel B-Cells and T-Cells Epitopes in the S1-Spike Glycoprotein of M41 and CR88 (793/B) Infectious Bronchitis Virus Serotypes for Application in Peptide Vaccines
    Bande F, Arshad SS, Hair Bejo M, Kadkhodaei S, Omar AR
    Adv Bioinformatics, 2016;2016:5484972.
    PMID: 27667997 DOI: 10.1155/2016/5484972
    Bioinformatic analysis was used to predict antigenic B-cell and T-cell epitopes within the S1 glycoprotein of M41 and CR88 IBV strains. A conserved linear B-cell epitope peptide, YTSNETTDVTS(175-185), was identified in M41 IBV strains while three such epitopes types namely, VSNASPNSGGVD(279-290), HPKCNFRPENI(328-338), and NETNNAGSVSDCTAGT(54-69), were predicted in CR88 IBV strains. Analysis of MHCI binding peptides in M41 IBV strains revealed the presence of 15 antigenic peptides out of which 12 were highly conserved in 96-100% of the total M41 strains analysed. Interestingly three of these peptides, GGPITYKVM(208), WFNSLSVSI(356), and YLADAGLAI(472), relatively had high antigenicity index (>1.0). On the other hand, 11 MHCI binding epitope peptides were identified in CR88 IBV strains. Of these, five peptides were found to be highly conserved with a range between 90% and 97%. However, WFNSLSVSL(358), SYNISAASV(88), and YNISAASVA(89) peptides comparably showed high antigenicity scores (>1.0). Combination of antigenic B-cells and T-cells peptides that are conserved across many strains as approach to evoke humoral and CTL immune response will potentially lead to a broad-based vaccine that could reduce the challenges in using live attenuated vaccine technology in the control of IBV infection in poultry.
  9. Antigenic potential of a recombinant polyvalent DNA vaccine against pathogenic leptospiral infection
    Garba B, Bahaman AR, Zakaria Z, Bejo SK, Mutalib AR, Bande F, et al.
    Microb Pathog, 2018 Nov;124:136-144.
    PMID: 30138761 DOI: 10.1016/j.micpath.2018.08.028
    Leptospirosis is a serious epidemic disease caused by pathogenic Leptospira species. The disease is endemic in most tropical and sub-tropical regions of the world. Currently, there is no effective polyvalent vaccine for prevention against most of the circulating serovars. Moreover, development of an efficient leptospiral vaccine capable of stimulating cross-protective immune responses against a wide range of serovars remains a daunting challenge. This, in part, is associated with the extensive diversity and variation of leptospiral serovars from region to region. In this study, a multi-epitope DNA vaccine encoding highly immunogenic epitopes from LipL32 and LipL41 was designed using in-silico approach. The DNA encoding antigenic epitopes was constructed from conserved pathogenic Leptospira genes (LipL32 and LipL41). Immunization of golden Syrian hamsters with the multi-epitope chimeric DNA vaccine resulted in the production of both agglutinating and neutralizing antibodies as evidence by MAT and in-vitro growth inhibition tests respectively. The antibodies produced reacted against eight different serovars and significantly reduced renal colonization following in vivo challenge. The vaccine was also able to significantly reduce renal colonization which is a very important factor responsible for persistence of leptospires among susceptible and reservoir animal hosts. In conclusion, the leptospiral multi-epitope chimeric DNA vaccine can serve as a potentially effective and safe vaccine against infection with different pathogenic leptospiral serovars.
  10. Investigations for the Possible Use of a Monoclonal Antibody Produced against Strongyloides ratti Antigen as an Immunodiagnostic Reagent for Active Strongyloidiasis
    Mahmuda A, Bande F, Abdulhaleem N, Abd Majid R, Awang Hamat R, Omar Abdullah W, et al.
    Iran J Parasitol, 2018 8 3;13(2):204-214.
    PMID: 30069204
    Background: Currently, most of the available serological diagnostic kits for strongyloidiasis are based on the use of the crude antigens of Strongyloides ratti, which are good, but with less sensitivity towards the infection. Hence, this study aimed to produce and evaluate monoclonal antibody for detecting soluble parasite antigen in animal sera.

    Methods: The study was conducted in the Department of Medical Microbiology and Parasitology, University Putra Malaysia in 2014-2017. Saline extract protein from the infective larvae of S. ratti was used to immunize BALB/c mice and subsequent fusion of the B-cells with myeloma cells (SP2/0) using 50% PEG. The hybridomas were cultured in HAT medium and cloned by limiting dilutions. Positive hybrids were screened by indirect ELISA. The ascites fluid from the antibody-secreting hybridoma was purified and the MAb was characterized by western-blots and evaluated in sandwich ELISA for reactivity against the homologous and heterologous antigens.

    Results: An IgG1 that recognizes a 30 and 34 kDa protein bands was obtained. The MAb was recognized by all S. ratti-related antigens and cross-reacted with only Toxocara canis antigens in both assays. The minimum antigen detection limit was found to be 5 ng/ml. All antibody-positive rat and dog sera evaluated have shown antigen-positive reactions in Sandwich-ELISA.

    Conclusion: The MAb produced, was able to detect antigens in strongyloidiasis and toxocariasis in animal models and may also be useful for the serological detection of active strongyloidiasis and visceral toxocariasis in human sera.

  11. First molecular detection of porcine bocavirus in Malaysia
    Mohan Jacob D, Lee CY, Arshad SS, Selvarajah GT, Bande F, Ong BL, et al.
    Trop Anim Health Prod, 2018 Apr;50(4):733-739.
    PMID: 29243138 DOI: 10.1007/s11250-017-1489-z
    Several strains of porcine bocaviruses have been reported worldwide since their first detection in Sweden in 2009. Subsequently, the virus has been reported to be associated with gastrointestinal and respiratory signs in weaner and grower pigs. Although Malaysia is host to a self-sufficient swine livestock industry, there is no study that describes porcine bocavirus in the country. This report is the first to describe porcine bocavirus (PBoV) in Malaysian swine herds. PBoV was identified in various tissues from sick and runt pigs using the conventional PCR method with primers targeting conserved regions encoding for the nonstructural protein (NS1) gene. Out of 103 samples tested from 17 pigs, 32 samples from 15 pigs were positive for porcine bocavirus. In addition, a higher detection rate was identified from mesenteric lymph nodes (52.9%), followed by tonsil (37.0%), and lungs (33.3%). Pairwise comparison and phylogenetic analyses based on a 658-bp fragment of NS1 gene revealed that the Malaysian PBoV strains are highly similar to PBoV3 isolated in Minnesota, USA. The presence of porcine bocavirus in Malaysia and their phylogenetic bond was marked for the first time by this study. Further studies will establish the molecular epidemiology of PBoV in Malaysia and clarify pathogenicity of the local isolates.
  12. Fulltext Major epidemiological factors associated with leptospirosis in Malaysia
    Garba B, Bahaman AR, Bejo SK, Zakaria Z, Mutalib AR, Bande F
    Acta Trop, 2018 Feb;178:242-247.
    PMID: 29217379 DOI: 10.1016/j.actatropica.2017.12.010
    INTRODUCTION: Leptospirosis is a zoonotic disease caused by a diverse pathogenic leptospira species and serovars. The disease is transmitted directly following contact with infected urine and other body fluids or indirectly after contact with water or soil contaminated with infected urine.

    OBJECTIVES: While a wide range of domestic and wild animals are known to be reservoirs of the disease, occupation, international travel and recreation are beginning to assume a center stage in the transmission of the disease. The objective of this study is to review available literatures to determine the extent to which these aforementioned risk factors aid the transmission, increase incidence and outbreak of leptospirosis in Malaysia.

    STUDY DESIGN: The review was conducted based on prevalence, incidence, and outbreak cases of leptospirosis among human and susceptible animals predisposed to several of the risk factors identified in Malaysia.

    METHODS: Literature searchers and reviews were conducted based on articles published in citation index journals, Malaysian ministry of health reports, periodicals as well as reliable newspapers articles and online media platforms. In each case, the newspapers and online media reports were supported by press briefings by officials of the ministry of health and other agencies responsible.

    RESULTS: The disease is endemic in Malaysia, and this was attributed to the large number of reservoir animals, suitable humid and moist environment for proliferation as well as abundant forest resources. Over 30 different serovars have been detected in Malaysia in different domestic and wild animal species. This, in addition to the frequency of flooding which has increased in recent years, and has helped increase the risk of human exposure. Occupation, recreation, flooding and rodent population were all identified as an important source and cause of the disease within the study population.

    CONCLUSION: There is an urgent need for the government and other stakeholders to intensify efforts to control the spread of the disease, especially as it greatly affect human health and the tourism industry which is an important component of the Malaysian economy. The risk of infection can be minimized by creating awareness on the source and mode of transmission of the disease, including the use of protective clothing and avoiding swimming in contaminated waters. Moreover, improved diagnostics can also help reduce the suffering and mortalities that follow infection after exposure to infection source.

  13. Global distributions and strain diversity of avian infectious bronchitis virus: a review
    Bande F, Arshad SS, Omar AR, Hair-Bejo M, Mahmuda A, Nair V
    Anim Health Res Rev, 2017 Jun;18(1):70-83.
    PMID: 28776490 DOI: 10.1017/S1466252317000044
    The poultry industry faces challenge amidst global food security crisis. Infectious bronchitis is one of the most important viral infections that cause huge economic loss to the poultry industry worldwide. The causative agent, infectious bronchitis virus (IBV) is an RNA virus with great ability for mutation and recombination; thus, capable of generating new virus strains that are difficult to control. There are many IBV strains found worldwide, including the Massachusetts, 4/91, D274, and QX-like strains that can be grouped under the classic or variant serotypes. Currently, information on the epidemiology, strain diversity, and global distribution of IBV has not been comprehensively reported. This review is an update of current knowledge on the distribution, genetic relationship, and diversity of the IBV strains found worldwide.
  14. Fulltext Prevalence and risk factors of feline leukaemia virus and feline immunodeficiency virus in peninsular Malaysia
    Bande F, Arshad SS, Hassan L, Zakaria Z, Sapian NA, Rahman NA, et al.
    BMC Vet Res, 2012 Mar 22;8:33.
    PMID: 22439903 DOI: 10.1186/1746-6148-8-33
    BACKGROUND: Feline leukaemia virus (FeLV) and feline immunodeficiency virus (FIV) are major causes of morbidity and mortality in domestic and wild felids. Despite the clinical importance of feline retroviruses and the growing interest in cats as pets, information about FeLV and FIV in Malaysia is presently insufficient to properly advise veterinarians and pet owners. A cross-sectional study was carried out from January 2010 to December 2010 to determine the prevalence and risk factors associated with FeLV and FIV among domestic cats in peninsular Malaysia. Plasma samples were harvested from the blood of 368 domestic cats and screened for evidence of FeLV p27 antigen and FIV antibodies, using an immunochromatographic kit. Additionally, data on cat demographics and health were collected using a structured questionnaire, and were evaluated as potential risk factors for FeLV or FIV status.

    RESULTS: Of the 368 cats that were evaluated in this study, 12.2% (45/368; 95% CI = 8.88 - 15.58) were positive for FeLV p27 antigen, 31.3%, (115/368; 95% CI = 26.51 - 35.99) were seropositive to FIV antibodies, and 4.3% (16/368; 95% CI = 2.27 - 6.43) had evidence of both viruses. Factors found to significantly increase the risk for FeLV seropositivity include sex, age, behaviour, sickness, and living in a multi-cat household. Seropositive response to FIV was significantly associated with sex, neuter status, age, behaviour, and health status.

    CONCLUSIONS: The present study indicates that FeLV and FIV are common among domestic cats in peninsular Malaysia, and that factors related to cat demographics and health such as age, sex, behaviour, health status and type of household are important predictors for seropositive status to FeLV or FIV in peninsular Malaysia. High prevalence of FeLV or FIV observed in our study is of concern, in view of the immunosuppressive potentials of the two pathogens. Specific measures for control and prevention such as screening and routine vaccination are needed to ensure that FeLV and FIV are controlled in the cat population of peninsular Malaysia.

  15. Fulltext Progress and challenges toward the development of vaccines against avian infectious bronchitis
    Bande F, Arshad SS, Bejo MH, Moeini H, Omar AR
    J Immunol Res, 2015;2015:424860.
    PMID: 25954763 DOI: 10.1155/2015/424860
    Avian infectious bronchitis (IB) is a widely distributed poultry disease that has huge economic impact on poultry industry. The continuous emergence of new IBV genotypes and lack of cross protection among different IBV genotypes have been an important challenge. Although live attenuated IB vaccines remarkably induce potent immune response, the potential risk of reversion to virulence, neutralization by the maternal antibodies, and recombination and mutation events are important concern on their usage. On the other hand, inactivated vaccines induce a weaker immune response and may require multiple dosing and/or the use of adjuvants that probably have potential safety risks and increased economic burdens. Consequently, alternative IB vaccines are widely sought. Recent advances in recombinant DNA technology have resulted in experimental IB vaccines that show promise in antibody and T-cells responses, comparable to live attenuated vaccines. Recombinant DNA vaccines have also been enhanced to target multiple serotypes and their efficacy has been improved using delivery vectors, nanoadjuvants, and in ovo vaccination approaches. Although most recombinant IB DNA vaccines are yet to be licensed, it is expected that these types of vaccines may hold sway as future vaccines for inducing a cross protection against multiple IBV serotypes.
  16. Fulltext Ultrastructure of Felis catus whole fetus (Fcwf-4) cell culture following infection with feline coronavirus
    Alazawy A, Arshad SS, Bejo MH, Omar AR, Tengku Ibrahim TA, Sharif S, et al.
    J Electron Microsc (Tokyo), 2011;60(4):275-82.
    PMID: 21593079 DOI: 10.1093/jmicro/dfr031
    Feline coronavirus (FCoV) consists of two biotypes based on their growth in cell culture and their antigenicity. Infections with FCoV are highly prevalent in the cat population worldwide. In this study, Felis catus whole fetus (Fcwf-4)cell culture was infected with FCoV UPM11C/08. Virus multiplication in cell culture was monitored and examined under the transmission electron microscope. The virus particles revealed the characteristic morphology of feline FCoV represented by envelope viruses surrounded by peplomers. Virus attachment and entry into the cell occurred 15 h post-infection (pi), and the myriad of virus particles were observed both extracellularly and intracellularly after 48 h pi. Thereafter, intracellular virus particles were observed to be present in vacuoles or present freely in the cytoplasm.
  17. The distribution of important sero-complexes of flaviviruses in Malaysia
    Kumar K, Arshad SS, Toung OP, Abba Y, Selvarajah GT, Abu J, et al.
    Trop Anim Health Prod, 2019 Mar;51(3):495-506.
    PMID: 30604332 DOI: 10.1007/s11250-018-01786-x
    Flaviviruses (FVs) are arthropod-borne viruses of medical and veterinary importance. Numerous species of FVs have been isolated from various host; mainly humans, animals, ticks, and mosquitoes. Certain FVs are extremely host-specific; at the same time, some FVs can infect an extensive range of species. Based on published literatures, 11 species of FVs have been detected from diverse host species in Malaysia. In humans, dengue virus and Japanese encephalitis virus have been reported since 1901 and 1942. In animals, the Batu Cave virus, Sitiawan virus, Carey Island, Tembusu virus, Duck Tembusu virus, and Japanese encephalitis viruses were isolated from various species. In mosquitoes, Japanese encephalitis virus and Kunjin virus were isolated from Culex spp., while Zika virus and Jugra virus were isolated from Aedes spp. In ticks, the Langat virus was isolated from Ixodes spp. One of the major challenges in the diagnosis of FVs is the presence of sero-complexes as a result of cross-reactivity with one or more FV species. Subsequently, the distribution of specific FVs among humans and animals in a specific population is problematic to assess and often require comprehensive and thorough analyses. Molecular assays such as quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and digital droplet RT-PCR (ddRT-PCR) have been used for the differentiation of flavivirus infections to increase the accuracy of epidemiological data for disease surveillance, monitoring, and control. In situations where sero-complexes are common in FVs, even sensitive assays such as qRT-pCR can produce false positive results. In this write up, an overview of the various FV sero-complexes reported in Malaysia to date and the challenges faced in diagnosis of FV infections are presented.
  18. Fulltext Japanese encephalitis in Malaysia: An overview and timeline
    Kumar K, Arshad SS, Selvarajah GT, Abu J, Toung OP, Abba Y, et al.
    Acta Trop, 2018 Sep;185:219-229.
    PMID: 29856986 DOI: 10.1016/j.actatropica.2018.05.017
    Japanese encephalitis (JE) is a vector-borne zoonotic disease caused by the Japanese encephalitis virus (JEV). It causes encephalitis in human and horses, and may lead to reproductive failure in sows. The first human encephalitis case in Malaya (now Malaysia) was reported during World War II in a British prison in 1942. Later, encephalitis was observed among race horses in Singapore. In 1951, the first JEV was isolated from the brain of an encephalitis patient. The true storyline of JE exposure among humans and animals has not been documented in Malaysia. In some places such as Sarawak, JEV has been isolated from mosquitoes before an outbreak in 1992. JE is an epidemic in Malaysia except Sarawak. There are four major outbreaks reported in Pulau Langkawi (1974), Penang (1988), Perak and Negeri Sembilan (1998-1999), and Sarawak (1992). JE is considered endemic only in Sarawak. Initially, both adults and children were victims of JE in Malaysia, however, according to the current reports; JE infection is only lethal to children in Malaysia. This paper describes a timeline of JE cases (background of each case) from first detection to current status, vaccination programs against JE, diagnostic methods used in hospitals and factors which may contribute to the transmission of JE among humans and animals in Malaysia.
  19. Fulltext Development and immunogenic potentials of chitosan-saponin encapsulated DNA vaccine against avian infectious bronchitis coronavirus
    Bande F, Arshad SS, Bejo MH, Omar AR, Moeini H, Khadkodaei S, et al.
    Microb Pathog, 2020 Dec;149:104560.
    PMID: 33068733 DOI: 10.1016/j.micpath.2020.104560
    Infectious Bronchitis (IB) is an economically important avian disease that considerably threatens the global poultry industry. This is partly, as a result of its negative consequences on egg production, weight gain as well as mortality rate.The disease is caused by a constantly evolving avian infectious bronchitis virus whose isolates are classified into several serotypes and genotypes that demonstrate little or no cross protection. In order to curb the menace of the disease therefore, broad based vaccines are urgently needed. The aim of this study was to develop a recombinant DNA vaccine candidate for improved protection of avian infectious bronchitis in poultry. Using bioinformatics and molecular cloning procedures, sets of monovalent and bivalent DNA vaccine constructs were developed based on the S1 glycoprotein from classical and variants IBV strains namely, M41 and CR88 respectively. The candidate vaccine was then encapsulated with a chitosan and saponin formulated nanoparticle for enhanced immunogenicity and protective capacity. RT-PCR assay and IFAT were used to confirm the transcriptional and translational expression of the encoded proteins respectively, while ELISA and Flow-cytometry were used to evaluate the immunogenicity of the candidate vaccine following immunization of various SPF chicken groups (A-F). Furthermore, histopathological changes and virus shedding were determined by quantitative realtime PCR assay and lesion scoring procedure respectively following challenge of various subgroups with respective wild-type IBV viruses. Results obtained from this study showed that, groups vaccinated with a bivalent DNA vaccine construct (pBudCR88-S1/M41-S1) had a significant increase in anti-IBV antibodies, CD3+ and CD8+ T-cells responses as compared to non-vaccinated groups. Likewise, the bivalent vaccine candidate significantly decreased the oropharyngeal and cloacal virus shedding (p < 0.05) compared to non-vaccinated control. Chickens immunized with the bivalent vaccine also exhibited milder clinical signs as well as low tracheal and kidney lesion scores following virus challenge when compared to control groups. Collectively, the present study demonstrated that bivalent DNA vaccine co-expressing dual S1 glycoprotein induced strong immune responses capable of protecting chickens against infection with both M41 and CR88 IBV strains. Moreso, it was evident that encapsulation of the vaccine with chitosan-saponin nanoparticle further enhanced immune responses and abrogates the need for multiple booster administration of vaccine. Therefore, the bivalent DNA vaccine could serve as efficient and effective alternative strategy for the control of IB in poultry.
  20. Fulltext Prevalence and risk factors of Japanese encephalitis virus (JEV) in livestock and companion animal in high-risk areas in Malaysia
    Kumar K, Arshad SS, Selvarajah GT, Abu J, Toung OP, Abba Y, et al.
    Trop Anim Health Prod, 2018 Apr;50(4):741-752.
    PMID: 29243139 DOI: 10.1007/s11250-017-1490-6
    Japanese encephalitis (JE) is vector-borne zoonotic disease which causes encephalitis in humans and horses. Clinical signs for Japanese encephalitis virus (JEV) infection are not clearly evident in the majority of affected animals. In Malaysia, information on the prevalence of JEV infection has not been established. Thus, a cross-sectional study was conducted during two periods, December 2015 to January 2016 and March to August in 2016, to determine the prevalence and risk factors in JEV infections among animals and birds in Peninsular Malaysia. Serum samples were harvested from the 416 samples which were collected from the dogs, cats, water birds, village chicken, jungle fowls, long-tailed macaques, domestic pigs, and cattle in the states of Selangor, Perak, Perlis, Kelantan, and Pahang. The serum samples were screened for JEV antibodies by commercial IgG ELISA kits. A questionnaire was also distributed to obtain information on the animals, birds, and the environmental factors of sampling areas. The results showed that dogs had the highest seropositive rate of 80% (95% CI: ± 11.69) followed by pigs at 44.4% (95% CI: ± 1.715), cattle at 32.2% (95% CI: ± 1.058), birds at 28.9% (95% CI: ± 5.757), cats at 15.6% (95% CI: ± 7.38), and monkeys at 14.3% (95% CI: ± 1.882). The study also showed that JEV seropositivity was high in young animals and in areas where mosquito vectors and migrating birds were prevalent.
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