Characterization of S1 gene sequence variations of attenuated QX-like and variant infectious bronchitis virus strains and the pathogenicity of the viruses in specific-pathogen-free chickens.

Besides the vaccine strains, the Malaysian variant (MV) and QX-like are the predominant IBVs detected on commercial poultry farms. These two virus strains are distinct based on genomic and pathogenicity studies. In this study, we determined the sequence of the S1 gene and compared the pathogenicity of serial passage 70 (P70) of Malaysian QX-like (QX/P70) and MV (MV/P70) strains with that of their respective wild-type viruses. The nucleotide and amino acid sequences of the complete S1 genes of QX/P70 and MV/P70 showed 1.4 to 1.6% and 3.0 to 3.3% variation, respectively, when compared to the wild-type virus. Most of the mutations were insertions and substitutions in the hypervariable regions (HVRs), primarily in HVR 3. Furthermore, selection pressure analysis showed that both viruses are under purifying selection. A pathogenicity study in specific-pathogen-free (SPF) chickens showed a reduction in respiratory and kidney lesions in chickens inoculated with MV/P70, but not with QX/P70, when compared to the respective wild-type viruses. However, MV/P70 is still pathogenic and can cause ciliary damage. In conclusion, the MV IBV strain is more responsive than the QX-like IBV strain following the attenuation process used for the development of a live attenuated IBV vaccine.

Evaluation of the antigen relatedness and efficacy of a single vaccination with different infectious bronchitis virus strains against a challenge with Malaysian variant and QX-like IBV strains.

BACKGROUND: The predominant infectious bronchitis virus (IBV) strains detected in chickens in Malaysia are the Malaysian variant (MV) and QX-like, which are associated with respiratory distress, nephropathy, and high mortality. On the other hand, the antigenic relatedness and efficacy of IBV vaccines against these 2 field IBV strains are not well characterized. OBJECTIVES: This study aimed to determine the antigen relatedness and efficacy of different IB vaccine strains against a challenge with MV and QX-like strains. METHODS: The antigen relatedness and the ability of different IB vaccine strains in conferring protection against MV and QX-like were assessed based on the clinical signs, macroscopic lesions, and ciliary activity. RESULTS: The MV strain IBS037A/2014 showed minor antigenic subtype differences with the vaccine virus Mass H120 and 4/91 strains but showed major antigenic subtype differences with the K2 strain. The Malaysian QX-like strain IBS130/2015 showed major antigenic subtype differences with the MV strain IBS037A/2014 and the vaccine strains except for K2. Chickens vaccinated once with Mass (H120) or with non-Mass (4/91 and K2) developed antibody responses with the highest antibody titer detected in the groups vaccinated with H120 and 4/91. The mean ciliary activities of the vaccinated chickens were between 56 to 59% and 48 to 52% in chickens challenged with IBS037A/2014 and IBS130/2015, respectively. The vaccinated and challenged birds showed mild to severe lesions in the lungs and kidneys. CONCLUSIONS: Despite the minor antigenic subtype differences, a single inoculation with Mass or non-Mass vaccines could not protect against the MV IBS037A/2014 and QX-like IBS130/2015.

Prevalence of Muscular Sarcosporidiosis in Slaughtered Domestic Pigs in Perak, Peninsular Malaysia.

Sarcosporidiosis is a disease caused by intracellular protozoan parasites, namely, Sarcocystis spp. In pigs, three species of Sarcocystis spp. have been recognised, including Sarcocystis meischeriana, Sarcocystis porcifelis and Sarcocystis suihominis. The aim of this study is to determine the prevalence of muscular sarcosporidiosis in pigs using the pepsin digestion technique. A total of 150 fresh heart, oesophagus and thigh muscle samples from 50 Yorkshire and Landrace pigs were collected from two local abattoirs in Perak from May to August 2014. All the fresh muscle samples were thoroughly examined for macrocyst-forming Sarcocystis spp. and processed using the peptic digestion technique to detect bradyzoites. The results from the muscle samples showed that 58% (29 out of 50) of the pigs were positive for Sarcocystis spp. These findings highlight the importance of implementing stringent measures for screening pigs in abattoirs for Sarcocystis spp. infection because this infection in pigs is a public health concern.

Screening for Zoonotic Fascioliasis in Slaughtered Large Ruminants in Abattoirs in Perak, Malaysia.

Fascioliasis, or trematode infestation, is an important disease caused by Fasciola hepatica and Fasciola gigantica. Both species are hepatic parasites that affect humans. We have examined the zoonotic aspects of fascioliasis. A total of 80 fresh liver samples were collected from 67 Kedah-Kelantan crossbred cattle and 13 Murrah buffalo at 4 local abattoirs in Perak, Malaysia. The samples were examined macroscopically to detect the presence of Fasciola spp. The results show 7.50% (6 of 80) of the animals were diagnosed with fascioliasis. Overall, 7.46% (5 of 67) and 7.69% (1 of 13) of cattle and buffalo samples were positive, respectively. There were only F. gigantica species identified in the samples. Our findings suggest that precautions should be taken because the disease has a zoonotic impact on public health.

The prevalence of parasitic infestation of small ruminant farms in perak, malaysia.

Helminthiasis due to strongyles such as Haemonchus contortus, coccidiosis caused by Eimeria sp. and blood parasite diseases such as theileriosis by Theileria sp. have been reported to cause severe morbidity and mortality annually in small ruminants in Malaysia. The aims of this study were to investigate the prevalence of helminthiasis, coccidiosis and theileriosis and to determine the packed cell volume (PCV) value of small ruminants in Perak, Malaysia. Blood and faecal samples were obtained from a total of 175 animals from 7 small ruminant farms in Kampar, Larut Matang and Selama, Kuala Kangsar and Manjung districts in Perak; the samples were examined for parasitic infestations from April to July 2011. The results of this study show that H. contortus was found in 152 (86.86%) animals, Eimeria sp. was found in 162 (92.57%) animals and the blood protozoa Theileria sp. was found in 25 (14.30%) animals. The PCV values of all of these animals were recorded between 7% and 44%. A total of 42 (24%) animals were anaemic, with a PCV of less than 21%. Continuous monitoring of small ruminant farms will provide important information for assisting farmers with managing the spread of parasitic infections and maintaining the productivity of animals.

Development of single tubing-type canister for cryo-storage of bull semen and their effect on sperm motility and viability

The objective of this study was to evaluate the potential of using single tubing-type canister on sperm quality. Semen was collected from the Bali cattle bull by electroejaculation technique and was cryopreserved in liquid nitrogen using slow freezing cryopreservation method. Two type of canister volume was used in this study; commercial canister (342.25π x 278 mm²) and single tubing-type canister (4π x 90 mm²). Makler counting chamber and computer assisted sperm analyzer (CASA) were used to evaluate the sperm motility and viability of post-thaw sperm. Results showed that the bull sperm motility and viability at the bottom of tubing-type canister was statistically higher and significant as compared to the commercial canister (p<0.05). Significant changes were found in sperm kinetics (VCL, VAP, VSL) of tubing-type canister compared to commercial canister. No significant changes in the motility and viability of the bull sperm at the top of tubing-type canister and commercial canister. There were no significant changes in sperm progression (LIN, WOB, PROG) in both the canisters. Developed tubing-type canister in this study showed potential as an alternative to be used in bull sperm cryo-storage.