Retrospective prevalence and associated risk factors of Mycoplasma haemofelis infection in owned cats.

Data on the prevalence and associated risk factors of naturally occurring haemoplasmosis in owned cats in Malaysia is limited. Being the most pathogenic of the three known feline haemoplasma species, Mycoplasma haemofelis (Mhf) infection was analysed from 2016 to 2019 to determine the periodical prevalence and associated risk factors in Northeastern Malaysia - Kelantan. Archived patient data of 77 clinically ill cats suspected of having M. haemofelis infection were reviewed in this study. Out of the 77 suspected cases, 53 (68.8%) were clinically diagnosed with haemoplasmosis amongst which 46 (59.7%) of the subpopulation were further confirmed with polymerase chain reaction (PCR). Risk factors for M. haemofelis infection (age, breed, ectoparasitism, household condition, roaming status, and sex) were analysed. There was no significant association of breed, ectoparasitism, household condition (number of cats) and occurrence of clinical signs with feline mycoplasmosis. Young, male and roamer cats were more likely to be diagnosed of mycoplasmosis than other categories of cats in this study. There was also a significant association between cats infected with 'Candidatus Mycoplasma haemominutum' with M. haemofelis. Thus, the coinfection of these two haemoplasma species is not uncommon. This study indicates that infection by M. haemofelis in anaemic cats is a common find in client-owned cats from Northeastern Malaysia. As the natural mode of transmission of haemoplasma infection remain unestablished, information in this study may highlight the importance of this disease and contribute to effective prevention and control strategies to minimize feline infectious anaemia (FIA) caused by M. haemofelis.

Quantitative Proteomics Analysis Revealed Compromised Chicken Dendritic Cells Function at Early Stage of Very Virulent Infectious Bursal Disease Virus Infection.

Chicken dendritic cells (DCs) have been demonstrated to be susceptible to infectious bursal disease virus (IBDV), a causative agent of acute and immunosuppressed disease in young chicks known as infectious bursal disease. Further functional characterization of IBDV-infected DCs of chickens is required to provide a better understanding on the influence of the virus on chicken bone marrow-derived dendritic cells (BM-DCs) following very virulent (vv) IBDV infection. Membrane proteins of BM-DCs were extracted and the proteins were further denatured and reduced before performing labeling with isobaric tags for relative and absolute quantitation. The differential expression protein profiles were identified and quantified using liquid chromatography coupled with tandem mass spectrometry, and later validated using flow cytometry and real-time reverse transcriptase PCR. The analysis has identified 134 differentially regulated proteins from a total of 283 proteins (cutoff values of ≤0.67, ≥1.5, and ProtScore >1.3 at 95% confidence interval), which produced high-yield membrane fractions. The entry of vvIBDV into the plasma membrane of BM-DCs was observed at 3 hr postinfection by the disruption of several important protein molecule functions, namely apoptosis, RNA/DNA/protein synthesis, and transport and cellular organization, without the activation of proteins associated with signaling. At the later stage of infection, vvIBDV induced expression of several proteins, namely CD200 receptor 1-A, integrin alpha-5, HSP-90, cathepsin, lysosomal-associated membrane protein, and Ras-related proteins, which play crucial roles in signaling, apoptosis, stress response, and antigen processing as well as in secretion of danger-associated proteins. These findings collectively indicated that the chicken DCs are expressing various receptors regarded as potential targets for pathogen interaction during viral infection. Therefore, fundamental study of the interaction of DCs and IBDV will provide valuable information in understanding the role of professional antigen-presenting cells in chickens and their molecular interactions during IBDV infection and vaccination.

Análisis proteómico cuantitativo revela el funcionamiento comprometido de células dendríticas del pollo en la etapa temprana de la infección con el virus muy virulento de la enfermedad infecciosa de la bolsa. Se ha demostrado que las células dendríticas de pollo (DC) son susceptibles al virus de la enfermedad infecciosa de la bolsa (IBDV), que es el agente causante de la enfermedad aguda e inmunodepresiva en pollos jóvenes conocida como enfermedad infecciosa de la bolsa. Se requiere una mayor caracterización funcional de las células dendríticas de pollos infectados con el virus de enfermedad infecciosa de la bolsa para proporcionar una mejor comprensión de la influencia del virus en las células dendríticas derivadas de la médula ósea (BM-DC), después de la infección por virus muy virulento. Se extrajeron proteínas de membrana de células dendríticas derivadas de la médula ósea, se desnaturalizaron y redujeron aún más antes de realizar el marcaje con etiquetas isobáricas para la cuantificación relativa y absoluta. Los perfiles de la expresión diferencial de proteínas se identificaron y cuantificaron utilizando cromatografía líquida junto con espectrometría de masas en tándem y luego se validaron utilizando citometría de flujo y transcripción reversa y PCR en tiempo real. El análisis identificó 134 proteínas reguladas diferencialmente de un total de 283 proteínas (valores de corte de ≤0.67, ≥1.5 y ProtScore> 1.3 con un intervalo de confianza del 95%), que produjeron fracciones de membrana de alto rendimiento. La entrada del virus muy virulento de la enfermedad infecciosa de la bolsa en la membrana plasmática de las células dendríticas derivadas de la médula ósea y se observó a las tres horas después de la infección por la interrupción de varias funciones importantes de las moléculas de proteínas por ejemplo, apoptosis, la síntesis de ARN/ADN/proteínas y transporte y organización celular, sin la activación de proteínas asociadas con la señalización. En la etapa posterior de la infección, el virus muy virulento de la enfermedad infecciosa indujo la expresión de varias proteínas, como el receptor CD200 1-A, la integrina alfa-5, HSP-90, catepsina, proteína de membrana asociada a lisosomas y las proteínas relacionadas con Ras, que desempeñan un papel crucial en la señalización, apoptosis, respuesta al estrés, procesamiento de antígenos, así como en la secreción de proteínas asociadas al peligro. Estos hallazgos indicaron en conjunto que las células dendríticas de pollo están expresando varios receptores considerados como objetivos potenciales para la interacción con patógenos durante la infección viral. Por lo tanto, el estudio fundamental de la interacción de las células dendríticas y el virus de la enfermedad infecciosa de la bolsa proporcionará información valiosa para comprender el papel de las células presentadoras de antígenos profesionales en pollos y sus interacciones moleculares durante la infección y vacunación con el virus de la enfermedad infecciosa de la bolsa.

Japanese encephalitis in Malaysia: An overview and timeline.

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.

Prevalence and risk factors of Japanese encephalitis virus (JEV) in livestock and companion animal in high-risk areas in Malaysia.

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.

Characterization of Chicken Splenic-Derived Dendritic Cells Following Vaccine and Very Virulent Strains of Infectious Bursal Disease Virus Infection.

Studies have shown that infectious bursal disease virus (IBDV) infects lymphoid cells, mainly B cells and macrophages. This study was aimed to examine the involvement of chicken splenic-derived dendritic cells (ch-sDCs) in specific-pathogen-free chickens following inoculation with IBDV vaccine strain (D78) and a very virulent (vv) strain (UPM0081). Following IBDV infection, enriched activated ch-sDCs were collected by using the negative selection method and were examined based on morphology and immunophenotyping to confirm the isolation method for dendritic cells (DCs). The presence of IBDV on enriched activated ch-sDCs was analyzed based on the immunofluorescence antibody test (IFAT), flow cytometry, and quantitative real-time PCR (RT-qPCR) while the mRNAs of several cytokines were detected using RT-qPCR. The isolated ch-sDCs resembled typical DC morphologies found in mammals by having a veiled shape and they grew in clusters. Meanwhile, the expression of DC maturation markers, namely CD86 and MHCII, were increased at day 2 and day 3 following vvIBDV and vaccine strain inoculation, respectively, ranging from 10% to 40% compared to the control at 2.55% (P < 0.05). At day 3 postinfection, IBDV VP3 proteins colocalized with CD86 were readily detected via IFAT and flow cytometry in both vaccine and vvIBDV strains. In addition, enriched activated ch-sDCs were also detected as positive based on the VP4 gene by RT-qPCR; however, a higher viral load was detected on vvIBDV compared to the vaccine group. Infection with vaccine and vvIBDV strains induced the enriched activated ch-sDCs to produce proinflammatory cytokines and Th1-like cytokines from day 3 onward; however, the expressions were higher in the vvIBDV group (P < 0.05). These data collectively suggest that enriched activated ch-sDCs were permissive to IBDV infection and produced a strong inflammatory and Th1-like cytokine response following vvIBDV infection as compared to the vaccine strain.

In vitro characterization of chicken bone marrow-derived dendritic cells following infection with very virulent infectious bursal disease virus.

Infectious bursal disease is caused by infectious bursal disease virus (IBDV), an immunosuppressive virus that targets immune cells such as B cells and macrophages. However, the involvement of dendritic cells (DCs) during IBDV infection is not well understood. In this study the in vitro effects of live and inactivated very virulent IBDV (vvIBDV) UPM0081 on bone marrow-derived DCs (BM-DC) were characterized and compared with BM-DC treated with lipopolysaccharide (LPS). Morphologically, BM-DC treated with LPS and vvIBDV showed stellate shape when compared to immature BM-DC. In addition, LPS-treated and both live and inactivated vvIBDV-infected BM-DC expressed high levels of double positive CD86 and major histocompatibility complex class II antigens (>20%). vvIBDV-infected BM-DC showed significantly higher numbers of apoptotic cells compared to LPS. Replication of vvIBDV was detected in the infected BM-DC as evidenced by the increased expression of VP3 and VP4 IBDV antigens based on flow cytometry, real-time polymerase chain reaction and immunofluorescence tests. Levels of different immune-related genes such as interleukin-1ß (IL-1ß), CXCLi2 (IL-8), IL-18, interferon gamma (IFN-γ, IL-12α, CCR7 and Toll-like receptor-3 (TLR3) were measured after LPS and vvIBDV treatments. However, marked differences were noticed in the onset and intensity of the gene expression between these two treatment groups. LPS was far more potent than live and inactivated vvIBDV in inducing the expression of IL-1ß, IL-18 and CCR7 while expression of Th1-like cytokines, IFN-γ and IL-12α were significantly increased in the live vvIBDV treatment group. Meanwhile, the expression of TLR3 was increased in live vvIBDV-infected BM-DC as compared to control. Inactivated vvIBDV-treated BM-DC failed to stimulate IFN-γ, IL-12α and TLR3 expressions. This study suggested that BM-DC may serve as another target cells during IBDV infection which require further confirmation via in vivo studies.