Displaying publications 21 - 40 of 81 in total

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  1. Development of SYBR green I based one-step real-time RT-PCR assay for the detection and differentiation of very virulent and classical strains of infectious bursal disease virus
    Kong LL, Omar AR, Hair Bejo M, Ideris A, Tan SW
    J Virol Methods, 2009 Nov;161(2):271-9.
    PMID: 19591873 DOI: 10.1016/j.jviromet.2009.06.023
    A SYBR Green I based one-step real-time reverse transcriptase polymerase chain reaction was developed for the detection and differentiation of very virulent (vv) and classical strains of infectious bursal disease virus (IBDV). The assay showed high PCR efficiency >93% and high reproducibility with coefficient of variation less than 0.5%. When tested on characterized IBDV strains, the very virulent and classical-specific primers detected accurately only vvIBDV and classical IBDV strains, respectively. The diagnostic efficacy of the assay was also tested on 140 bursal samples from experimental infection and 37 bursal samples from cases suspected of IBD. The assay was able to detect IBDV from bursal samples collected at days 3 and 5 post-infection with the vvIBDV strain UPM94/273 and the classical IBDV strain D78. The assay was also able to detect bursal samples infected dually with D78 and UPM94/273. The melting temperature values of the amplification products from the classical and very virulent viral infection were statistically significant (P<0.05). The specificity of the assay for detecting IBDV from suspected cases was confirmed by sequence analysis of the VP2 gene. The assay showed high sensitivity since bursal samples which were negative for IBDV were confirmed by virus isolation and PCR amplification. Hence, the new assay offers an attractive method for rapid detection of strains of IBDV.
  2. Development of a modified method for sequencing high G:C regions in chicken anemia virus genome
    Chowdhury SM, Omar AR, Aini I, Hair-Bejo M, Jamaluddin AA, Wan KL, et al.
    J. Biochem. Mol. Biol. Biophys., 2002 Jun;6(3):229-32.
    PMID: 12186760
    Two areas in the chicken anemia virus (CAV) genome have high G:C content with secondary structures. These two G:C rich areas could not be sequenced with Perkin Elmer's Big Dye Terminator Cycle Sequencing Kit. Several modifications were carried out to solve the problem. Finally, a package of modified method was developed to sequence the high G:C areas. The result showed that the Perkin Elmer's Big Dye Terminator Cycle Sequencing Kit with the normal procedures are not suitable for sequencing the high G:C regions of the CAV genome. The present developed method made the Perkin Elmer's Kit useful for the first time to sequence the G:C rich hairpin structures of the CAV genome. The system may be useful to sequence all other G:C rich DNA templates.
  3. Fulltext Diagnostic and Vaccination Approaches for Newcastle Disease Virus in Poultry: The Current and Emerging Perspectives
    Bello MB, Yusoff K, Ideris A, Hair-Bejo M, Peeters BPH, Omar AR
    Biomed Res Int, 2018;2018:7278459.
    PMID: 30175140 DOI: 10.1155/2018/7278459
    Newcastle disease (ND) is one of the most devastating diseases that considerably cripple the global poultry industry. Because of its enormous socioeconomic importance and potential to rapidly spread to naïve birds in the vicinity, ND is included among the list of avian diseases that must be notified to the OIE immediately upon recognition. Currently, virus isolation followed by its serological or molecular identification is regarded as the gold standard method of ND diagnosis. However, this method is generally slow and requires specialised laboratory with biosafety containment facilities, making it of little relevance under epidemic situations where rapid diagnosis is seriously needed. Thus, molecular based diagnostics have evolved to overcome some of these difficulties, but the extensive genetic diversity of the virus ensures that isolates with mutations at the primer/probe binding sites escape detection using these assays. This diagnostic dilemma leads to the emergence of cutting-edge technologies such as next-generation sequencing (NGS) which have so far proven to be promising in terms of rapid, sensitive, and accurate recognition of virulent Newcastle disease virus (NDV) isolates even in mixed infections. As regards disease control strategies, conventional ND vaccines have stood the test of time by demonstrating track record of protective efficacy in the last 60 years. However, these vaccines are unable to block the replication and shedding of most of the currently circulating phylogenetically divergent virulent NDV isolates. Hence, rationally designed vaccines targeting the prevailing genotypes, the so-called genotype-matched vaccines, are highly needed to overcome these vaccination related challenges. Among the recently evolving technologies for the development of genotype-matched vaccines, reverse genetics-based live attenuated vaccines obviously appeared to be the most promising candidates. In this review, a comprehensive description of the current and emerging trends in the detection, identification, and control of ND in poultry are provided. The strengths and weaknesses of each of those techniques are also emphasised.
  4. Fulltext Diagnostic methods for feline coronavirus: a review
    Sharif S, Arshad SS, Hair-Bejo M, Omar AR, Zeenathul NA, Alazawy A
    Vet Med Int, 2010;2010.
    PMID: 20798771 DOI: 10.4061/2010/809480
    Feline coronaviruses (FCoVs) are found throughout the world. Infection with FCoV can result in a diverse range of signs from clinically inapparent infections to a highly fatal disease called feline infectious peritonitis (FIP). FIP is one of the most serious viral diseases of cats. While there is neither an effective vaccine, nor a curative treatment for FIP, a diagnostic protocol for FCoV would greatly assist in the management and control of the virus. Clinical findings in FIP are non-specific and not helpful in making a differential diagnosis. Haematological and biochemical abnormalities in FIP cases are also non-specific. The currently available serological tests have low specificity and sensitivity for detection of active infection and cross-react with FCoV strains of low pathogenicity, the feline enteric coronaviruses (FECV). Reverse transcriptase polymerase chain reaction (RT-PCR) has been used to detect FCoV and is rapid and sensitive, but results must be interpreted in the context of clinical findings. At present, a definitive diagnosis of FIP can be established only by histopathological examination of biopsies. This paper describes and compares diagnostic methods for FCoVs and includes a brief account of the virus biology, epidemiology, and pathogenesis.
  5. Fulltext Dietary methionine and n-6/n-3 polyunsaturated fatty acid ratio reduce adverse effects of infectious bursal disease in broilers
    Maroufyan E, Kasim A, Ebrahimi M, Loh TC, Hair-Bejo M, Soleimani AF
    Poult Sci, 2012 Sep;91(9):2173-82.
    PMID: 22912451 DOI: 10.3382/ps.2012-02317
    This study was carried out to investigate the modulatory effects of dietary methionine and n-6/n-3 polyunsaturated fatty acids (PUFA) ratio on immune response and performance of infectious bursal disease (IBD)-challenged broiler chickens. In total, 350 one-day-old male broiler chicks were assigned to 1 of the 6 dietary treatment groups in a 3 × 2 factorial arrangement. There were 3 n-6/n-3 PUFA ratios (45, 5.5, and 1.5) and 2 levels of methionine (NRC recommendation and twice NRC recommendation). The results showed that birds fed with dietary n-6/n-3 PUFA ratio of 5.5 had higher BW, lower feed intake, and superior FCR than other groups. However, the highest antibody response was observed in birds with dietary n-6/n-3 PUFA ratio of 1.5. Lowering n-6/n-3 PUFA ratio reduced bursa lesion score equally in birds fed with n-6/n-3 PUFA ratio of 5.5 and 1.5. Supplementation of methionine by twice the recommendation also improved FCR and reduced feed intake and bursa lesion score. However, in this study, the optimum performance (as measured by BW, feed intake, and FCR) did not coincide with the optimum immune response (as measured by antibody titer). It seems that dietary n-3 PUFA modulates the broiler chicken performance and immune response in a dose-dependent but nonlinear manner. Therefore, it can be suggested that a balance of moderate level of dietary n-6/n-3 PUFA ratio (5.5) and methionine level (twice recommendation) might enhance immune response together with performance in IBD-challenged broiler chickens.
  6. Dietary putrescine effects on performance parameters, nutrient digestibility, intestinal morphology and tissue polyamine content of broilers fed low protein diet
    Hashemi SM, Loh TC, Foo HL, Zulkifli I, Hair-Bejo M
    Iran J Vet Res, 2014;15(4):385-91.
    PMID: 27175136
    This study was carried out to investigate the effects of dietary putrescine (PUT) on broiler's response fed low crude protein (CP) diets. A total of 192 male day old chicks were fed with four dietary treatments including two levels of PUT (0 and 0.03%) and two levels of CP (normal and low) with factorial combinations. Weekly growth performance, nutrient digestibility and intestinal morphology (at the age of 21 days) and liver and intestinal tissue polyamines content were measured. As a result of this study lower dietary CP had a significant (P<0.05) lower body weight gain (BWG) and improved protein efficiency ratio (PER). PUT improved energy efficiency ratio (EER) significantly (P<0.05). Dry matter (DM) digestibility was decreased by lower dietary CP whereas 0.03% PUT significantly (P<0.05) increased it. Low CP caused significant (P<0.05) greater calcium digestibility, while this effect was not found when PUT was added. PUT had no effect on intestine villous height and crypt depth. Polyamine content of intestine and liver was influenced by the age of the birds, while PUT had no effects on them. In conclusion, dietary PUT has beneficial effects on EER in chicks fed CP-deficient diet, indicating possible involvement of PUT in energy metabolism. PUT supplementation did not moderate the reduced BWG of the chicks fed low protein. Intestinal and liver polyamine concentration was mainly affected by dietary CP and age of the birds rather than dietary PUT.
  7. Fulltext Dietary zinc treatment for chronic copper intoxication in palm kernel cake (PKC) fed sheep
    Hair-Bejo M, Alimon A, Maria J, Hass M, Moonafizad M
    Malays J Nutr, 1996 Sep;2(2):196-206.
    PMID: 22692141
    Thirty, 4 month-old male Maim x Polled Dorset crossbred sheep were allocated into 6 groups of 5 animals each. Four groups of animals were stall-fed with basal diet of 90% palm kernel cake (PKC) and 10% grass (G) for 16 weeks. One group of the animal was slaughtered at the end of the 16 weeks feeding trial (PKC group), whilst the other three groups were further fed with either the same diet (PKC+PKC group) or fed with a new diet consisting of 30% corn and 10% fish meals (CF) and grass (60%) either with (PKC+CF+Zn group) or without (PKC+CF group) zinc supplementation (500 mg/g Zn as zinc sulfate) for another 16 weeks and were slaughtered at the end of the feeding trial, The other two groups which act as controls were fed with corn (30%) and fish meals (10%) and grass (60%), and were slaughtered at weeks 16 (CF group) and 32 (CF+CF group) of the trial. The blood, right and left liver, renal cortex and medulla, pancreas, bile and urine of all animals were analysed for copper and zinc contents using an atomic absorption spectrophotometer. The liver and kidney were also fixed in 10% buffered formalin for histopathological examination. The study showed that neither clinical signs nor gross lesions of copper or zinc toxicity were observed throughout the trial. However, the copper concentration in both the right and left liver of PKC fed sheep at weeks 16 and 32 rose to about 3 times that of the controls and remained high in both the PKC+CF and PKC+CF+Zn groups. A similar pattern of copper concentration was observed in the blood. The copper and zinc contents in the renal cortex and medulla, pancreas, bile and urine remained low in all groups. The zinc content in the liver of PKC+CF+Zn group was significantly increased. Histologically, moderate hepatic lesions were observed in the PKC fed sheep at week 32. The lesions were milder in the other groups especially in the PKC+CF+Zn group. No significant renal lesions was recorded in all groups. It was concluded that the usage of dietary zinc supplementation (500 mg/g) in the treatment of PKC toxicity in sheep was unsatisfactory. The ability of Malin x Polled Dorset crossbred sheep to tolerate the high copper content in PKC at least during the first 16 weeks of the feeding trial may provide more avenue in the utilization of PKC as a major feed ingredient in sheep.
  8. Differential activation of intraepithelial lymphocyte-natural killer cells in chickens infected with very virulent and vaccine strains of infectious bursal disease virus
    Jahromi MZ, Bello MB, Abdolmaleki M, Yeap SK, Hair-Bejo M, Omar AR
    Dev Comp Immunol, 2018 10;87:116-123.
    PMID: 29886054 DOI: 10.1016/j.dci.2018.06.004
    To gain insights into the role of CD3-/28.4+ intraepithelial lymphocytes-natural killer (CD3-/28.4+IEL-NK) cells during infectious bursal disease virus (IBDV) infection, characterisation of the cells was performed following infection with different strains of the virus. In vitro treatment with IL-18 or ionomycin/PMA successfully stimulated and activated the cells via a significant increase in the expression of CD69, B-Lec, CHIR-AB1 and NK-lysin. Similarly, chickens infected with the vaccine strain of IBDV also up-regulated the expression of CD69, B-Lec, CHIR-AB1 and NK-lysin in CD3-/28.4+ IEL-NK cells up to 3 days post infection (dpi) and down-regulated the expression of the inhibitory receptor B-NK at 3 dpi. On the contrary, infection with the very virulent IBDV (vvIBDV) strain lead to a reduced activation of the cells by down-regulating the expression of the CD69, CHIR-AB1 and NK-lysin especially at 1 dpi. These findings altogether demonstrate the differential activation of CD3-/28.4+IEL-NK cells in chicken following infection with the vaccine or very virulent strains of IBDV. The study therefore provides an important clue into the differential pathogenesis of IBDV infection in chicken. Further studies are however required to determine the functional importance of these findings during IBDV vaccination and infection.
  9. Fulltext Effects of Brown Seaweed (Sargassum polycystum) Extracts on Kidney, Liver, and Pancreas of Type 2 Diabetic Rat Model
    Motshakeri M, Ebrahimi M, Goh YM, Othman HH, Hair-Bejo M, Mohamed S
    Evid Based Complement Alternat Med, 2014;2014:379407.
    PMID: 24516503 DOI: 10.1155/2014/379407
    The edible seaweed Sargassum polycystum (SP) is traditionally used against several human diseases. This investigation evaluated the effects of two dietary doses of SP ethanolic and aqueous extracts on the pancreatic, hepatic, and renal morphology of type 2 diabetic rats (T2DM). T2DM was induced by feeding rats on high calorie diet followed by a low dose streptozotocin. Changes in the diabetic rat organs in SP treated groups with different doses of extracts were compared with normal rats, diabetic control rats, and metformin treated rats. After 22 days of treatment, the pathological lesions of the livers and kidneys in the diabetic rats were quantitatively and qualitatively alleviated (P < 0.05) by both the SP extracts at 150 mg/kg body weight and by metformin. All the treated diabetic groups revealed marked improvement in the histopathology of the pancreas compared with the control diabetic group. Oral administration of 300 mg/kg body weight of aqueous and ethanolic extracts of SP and metformin revealed pancreas protective or restorative effects. The seaweed extracts at 150 mg/kg body weight reduced the liver and kidney damages in the diabetic rats and may exert tissue repair or restoration of the pancreatic islets in experimentally induced diabetes to produce the beneficial homeostatic effects.
  10. Effects of early age feed restriction and heat conditioning on heat shock protein 70 expression, resistance to infectious bursal disease, and growth in male broiler chickens subjected to heat stress
    Liew PK, Zulkifli I, Hair-Bejo M, Omar AR, Israf DA
    Poult Sci, 2003 Dec;82(12):1879-85.
    PMID: 14717545
    The effects of early age feed restriction and heat conditioning on heat shock protein (HSP) 70 expression, antibody production, resistance to infectious bursal disease (IBD), and growth of heat-stressed male broiler chickens were investigated. Chicks were divided into 4 groups: 60% feed restriction on d 4,5, and 6 (FR); exposure to 36 +/- 1 degrees C for 1 h from d 1 to 21 (HT); combination of FR and HT (FRHT); and control. From d 35 to 50, heat stress was induced by exposing birds to 38 +/- 1 degrees C and 80% RH for 2 h/d. On d 36, each bird was administered 10 times the normal dose of live IBD vaccine. After heat exposure, the FRHT birds had higher HSP 70 density (d 41) and weight gain (from d 35 to 49) and lower bursal histological score (BHS) (d 51) than their HT and control counterparts. The HSP 70 expression and BHS of FR birds were not significantly different from those of the other 3 groups during the heat exposure period. Heat shock protein 70 and BHS data were negatively correlated (r = -0.33, P = 0.0008). We concluded that FRHT could improve weight gain and resistance to IBD in male broiler chickens under heat stress conditions. The improved heat tolerance and disease resistance in FRHT birds could be attributed to better HSP 70 response.
  11. Effects of feeding metabolite combinations produced by Lactobacillus plantarum on growth performance, faecal microbial population, small intestine villus height and faecal volatile fatty acids in broilers
    Thanh NT, Loh TC, Foo HL, Hair-Bejo M, Azhar BK
    Br Poult Sci, 2009 May;50(3):298-306.
    PMID: 19637029 DOI: 10.1080/00071660902873947
    1. Four combinations of metabolites produced from strains of Lactobacillus plantarum were used to study the performance of broiler chickens. 2. A total of 432 male Ross broilers were raised from one-day-old to 42 d of age in deep litter pens (12 birds/pen). These birds were divided into 6 groups and fed on different diets: (i) standard maize-soybean-based diet (negative control); (ii) standard maize-soybean-based diet + Neomycin and Oxytetracycline (positive control); (iii) standard maize-soybean-based diet + 0.3% metabolite combination of Lactobacillus plantarum RS5, RI11, RG14 and RG11 strains (com3456); (iv) standard maize-soybean-based diet + 0.3% metabolite combination of L. plantarum TL1, RI11 and RG11 (Com246); (v) standard maize-soybean-based diet + 0.3% metabolite combination of L. plantarum TL1, RG14 and RG11 (Com256) and (vi) standard maize-soybean-based diet + 0.3% metabolite combination of L. plantarum TL1, RS5, RG14 and RG11 (Com2356). 3. Higher final body weight, weight gain, average daily gain and lower feed conversion ratio were found in all 4 treated groups. 4. The addition of a metabolite combination supplementation also increased faecal lactic acid bacteria population, small intestine villus height and faecal volatile fatty acids and faecal Enterobacteriaceae population.
  12. Fulltext Efficacy of a bacteriophage isolated from chickens as a therapeutic agent for colibacillosis in broiler chickens
    Lau GL, Sieo CC, Tan WS, Hair-Bejo M, Jalila A, Ho YW
    Poult Sci, 2010 Dec;89(12):2589-96.
    PMID: 21076096 DOI: 10.3382/ps.2010-00904
    The efficacy of bacteriophage EC1, a lytic bacteriophage, against Escherichia coli O78:K80, which causes colibacillosis in poultry, was determined in the present study. A total of 480 one-day-old birds were randomly assigned to 4 treatments groups, each with 4 pens of 30 birds. Birds from the control groups (groups I and II) received PBS (pH 7.4) or 10(10) pfu of bacteriophage EC1, respectively. Group III consisted of birds challenged with 10(8) cfu of E. coli O78:K80 and treated with 10(10) pfu of bacteriophage EC1 at 2 h postinfection, whereas birds from group IV were challenged with 10(8) cfu of E. coli O78:K80 only. All the materials were introduced into the birds by intratracheal inoculation. Based on the results of the present study, the infection was found to be less severe in the treated E. coli-challenged group. Mean total viable cell counts of E. coli identified on eosin methylene blue agar (designated EMB + E. coli) in the lungs were significantly lower in treated, E. coli-challenged birds than in untreated, E. coli-challenged birds on d 1 and 2 postinfection. The EMB + E. coli isolation frequency was also lower in treated birds; no E. coli was detectable in blood samples on any sampling day, and E. coli were isolated only in the liver, heart, and spleen of treated chickens at a ratio of 2/6, 1/6, and 3/6, respectively, at d 1 postinfection. The BW of birds from the E. coli-challenged group treated with bacteriophage EC1 were not significantly different from those of birds from both control groups but were 15.4% higher than those of the untreated, E. coli-challenged group on d 21 postinfection. The total mortality rate of birds during the 3-wk experimental period decreased from 83.3% in the untreated, E. coli-challenged birds (group IV) to 13.3% in birds treated with bacteriophage EC1 (group III). These results suggest that bacteriophage EC1 is effective in vivo and could be used to treat colibacillosis in chickens.
  13. Fulltext Efficacy, humoral, and cell-mediated immune response of inactivated fowl adenovirus 8b propagated in chicken embryo liver cells using bioreactor in broiler chickens
    Ugwu CC, Hair-Bejo M, Nurulfiza MI, Omar AR, Ideris A
    Vet World, 2022 Nov;15(11):2681-2692.
    PMID: 36590109 DOI: 10.14202/vetworld.2022.2681-2692
    BACKGROUND AND AIM: Fowl adenovirus (FAdV) 8b causes inclusion body hepatitis, resulting in major economic losses globally among chickens. The objectives were to inactivate FAdV 8b isolate propagated in chicken embryo liver (CEL) cells using a stirred tank bioreactor (UPM08136P5B1) and determine the humoral and cell-mediated immune response, efficacy, and virus shedding in broiler chickens.

    MATERIALS AND METHODS: The FAdV 8b isolate UPM08136P5B1 was inactivated using binary ethyleneimine, adjuvanted with Montanide 71VG, inoculated into day-old broiler chickens in a booster group (BG) and non-booster group (NBG), and challenged with a pathogenic FAdV 8b strain. Clinical signs, gross lesions, body weight (BW), liver: body weight ratio, FAdV antibody titer using enzyme-linked immunosorbent assay, and histopathological changes were recorded. The CD3+, CD4+, and CD8+ T-lymphocyte profiles of the liver, spleen, and thymus using flow cytometry, and viral load in liver and cloacal shedding using quantitative polymerase chain reaction were evaluated.

    RESULTS: Chickens in the challenged control group (CCG) exhibited mild clinical signs, gross lesions, and histopathological changes, which were absent in the inoculated groups, and had lower BW and higher liver BW ratio than chickens in the unchallenged control group (UCG); BG and NBG on 35- and 42-days post-inoculation (DPI). Chickens in NBG and BG had higher antibodies than UCG on 7, 21, 35, and 42 DPI. The challenged BG and NBG produced higher antibodies than the CCG on 35 DPI. T-lymphocytes were higher among the inoculated groups than UCG in the liver, spleen, and thymus. Inoculated challenged groups recorded higher CD3+, CD4+, and CD8+ T-lymphocytes on 35 and 42 DPI than CCG. The challenged control group had a significantly higher viral load in the liver than challenged that in BG on 35 DPI and BG and NBG on 42 DPI. The challenged control group had significantly higher challenge FAdV shedding than challenged inoculated groups on 35 and NBG on 42 DPI.

    CONCLUSION: UPM08136P5B1 was successfully inactivated and mixed with Montanide 71VG. The inactivated vaccine candidate that induced humoral and cellular immunity was effective, reduced FAdV load in the liver, and shedding in the cloaca, and could be useful against FAdV 8b infections in chickens.

  14. Fulltext Efficacy, immunogenicity, and virus shedding in broiler chickens inoculated with live attenuated fowl adenovirus serotype 8b propagated a bioreactor
    Ugwu CC, Hair-Bejo M, Nurulfiza MI, Omar AR, Ideris A
    Open Vet J, 2024 Feb;14(2):617-629.
    PMID: 38549580 DOI: 10.5455/OVJ.2024.v14.i2.2
    BACKGROUND: Fowl adenovirus (FAdV) 8b causes huge economic losses in the poultry industry worldwide. Attenuated FAdV 8b could be useful in preventing FAdV infections globally and scale-up obstacles could be solved by bioreactor technology.

    AIM: This study was carried out to attenuate the FAdV 8b isolate, propagate it in a bioreactor, molecularly characterize the passage isolates, and determine the immunogenicity, efficacy, and shedding of the virus of chickens.

    METHODS: FAdV serotype 8b (UPM11142) isolate was passaged on chicken embryo liver (CEL) cells until attenuation and propagated in a bioreactor (UPM11142P20B1). Hexon and fiber genes of the isolates were sequenced and analyzed. UPM11142P20B1 was administered to 116-day-old broiler chickens divided into four groups, A (control), B (non-booster), C (booster with UPM11142P20B1), and D (booster with inactivated UPM11142P5B1). Eight chickens from each group were challenged. Body weight (BW) and liver weight (LW), liver: BW ratio (LBR), FAdV antibody titer, T lymphocyte sub-populations in the liver, spleen and thymus; and challenge virus load in the liver and shedding in cloaca were measured at weekly intervals.

    RESULTS: The isolate caused typical cytopathic effects on CEL cells typical of FAdV. Novel molecular changes in the genes occurred which could be markers for FAdV 8b attenuation. BW, LW, and LBR were similar among groups throughout the trial but the uninoculated control-challenged group (UCC) had significantly higher LBR than the inoculated and challenged groups at 35 dpi. Non-booster group had higher FAdV antibodies at all time points than the uninoculated control group (UCG); and the challenged booster groups had higher titer at 35 dpi than UCC. T lymphocytes increased at different time-points in the liver of inoculated chickens, and in the spleen and thymus as well, and was higher in the organs of inoculated challenged groups than the UCC. There was a significantly higher challenge virus load in the liver and cloaca of UCC chickens than in the non-booster chickens.

    CONCLUSION: UPM11142P20B1 was safe, efficacious, significantly reduced shedding, and is recommended as a candidate vaccine in the prevention and control of FAdV 8b infections in broiler chickens.

  15. Egg production, faecal pH and microbial population, small intestine morphology, and plasma and yolk cholesterol in laying hens given liquid metabolites produced by Lactobacillus plantarum strains
    Choe DW, Loh TC, Foo HL, Hair-Bejo M, Awis QS
    Br Poult Sci, 2012;53(1):106-15.
    PMID: 22404811 DOI: 10.1080/00071668.2012.659653
    1. Various dosages of metabolite combinations of the Lactobacillus plantarum RI11, RG14 and RG11 strains (COM456) were used to study the egg production, faecal microflora population, faecal pH, small intestine morphology, and plasma and egg yolk cholesterol in laying hens. 2. A total of 500 Lohmann Brown hens were raised from 19 weeks to 31 weeks of age. The birds were randomly divided into 5 groups and fed on various treatment diets: (i) basal diet without supplementation of metabolites (control); (ii) basal diet supplemented with 0·3% COM456 metabolites; (iii) basal diet supplemented with 0·6% COM456 metabolites; (iv) basal diet supplemented with 0·9% COM456 metabolites; and (v) basal diet supplemented with 1·2% COM456 metabolites. 3. The inclusion of 0·6% liquid metabolite combinations, produced from three L. plantarum strains, demonstrated the best effect in improving the hens' egg production, faecal lactic acid bacteria population, and small intestine villus height, and reducing faecal pH and Enterobacteriaceae population, and plasma and yolk cholesterol concentrations. 4. The metabolites from locally isolated L. plantarum are a possible alternative feed additive in poultry production.
  16. Epigenetic modification: possible approach to reduce Salmonella enterica serovar enteritidis susceptibility under stress conditions
    Soleimani AF, Zulkifli I, Hair-Bejo M, Ebrahimi M, Jazayeri SD, Hashemi SR, et al.
    Avian Pathol, 2012;41(4):351-4.
    PMID: 22834548 DOI: 10.1080/03079457.2012.691155
    Stressors may influence chicken susceptibility to pathogens such as Salmonella enterica. Feed withdrawal stress can cause changes in normal intestinal epithelial structure and may lead to increased attachment and colonization of Salmonella. This study aimed to investigate modulatory effects of epigenetic modification by feed restriction on S. enterica serovar Enteritidis colonization in broiler chickens subjected to feed withdrawal stress. Chicks were divided into four groups: ad libitum feeding; ad libitum feeding with 24-h feed withdrawal on day 42; 60% feed restriction on days 4, 5, and 6; and 60% feed restriction on days 4, 5, and 6 with 24-h feed withdrawal on day 42. Attachment of S. Enteritidis to ileal tissue was determined using an ex vivo ileal loop assay, and heat shock protein 70 (Hsp70) expression was evaluated using sodium dodecyl sulphate-polyacrylamide gel electrophoresis and western blotting. Feed withdrawal stress increased S. Enteritidis attachment to ileal tissue. However, following feed withdrawal the epigenetically modified chickens had significantly lower attachment of S. Enteritidis than their control counterparts. A similar trend with a very positive correlation was observed for Hsp70 expression. It appears that epigenetic modification can enhance resistance to S. Enteritidis colonization later in life in chickens under stress conditions. The underlying mechanism could be associated with the lower Hsp70 expression in the epigenetically modified chickens.
  17. Evaluation of a lytic bacteriophage, Φ st1, for biocontrol of Salmonella enterica serovar Typhimurium in chickens
    Wong CL, Sieo CC, Tan WS, Abdullah N, Hair-Bejo M, Abu J, et al.
    Int J Food Microbiol, 2014 Feb 17;172:92-101.
    PMID: 24361838 DOI: 10.1016/j.ijfoodmicro.2013.11.034
    In this study, a Salmonella Typhimurium lytic bacteriophage, Φ st1, which was isolated from chicken faecal material, was evaluated as a candidate for biocontrol of Salmonella in chickens. The morphology of Φ st1 showed strong resemblance to members of the Siphoviridae family. Φ st1 was observed to be a DNA phage with an estimated genome size of 121 kbp. It was found to be able to infect S. Typhimurium and S. Hadar, with a stronger lytic activity against the former. Subsequent characterisation of Φ st1 against S. Typhimurium showed that Φ st1 has a latent period of 40 min with an average burst size of 22 particles per infective centre. Approximately 86.1% of the phage adsorbed to the host cells within the initial 5 min of infection. At the optimum multiplicity of infection (MOI) (0.1), the highest reduction rate of S. Typhimurium (6.6 log₁₀ CFU/ml) and increment in phage titre (3.8 log₁₀ PFU/ml) was observed. Φ st1 produced adsorption rates of 88.4-92.2% at pH7-9 and demonstrated the highest bacteria reduction (6.6 log₁₀ CFU/ml) at pH9. Φ st1 also showed an insignificant different (P>0.05) reduction rate of host cells at 37 °C (6.4 log₁₀ CFU/ml) and 42 °C (6.0 log₁₀ CFU/ml). The in vivo study using Φ st1 showed that intracloacal inoculation of ~10¹² PFU/ml of the phage in the chickens challenged with ~10¹⁰ CFU/ml of S. Typhimurium was able to reduce (P<0.05) the S. Typhimurium more rapidly than the untreated group. The Salmonella count reduced to 2.9 log₁₀ CFU/ml within 6h of post-challenge and S. Typhimurium was not detected at and after 24h of post-challenge. Reduction of Salmonella count in visceral organs was also observed at 6h post-challenge. Approximately 1.6 log₁₀ FU/ml Φ st1 was found to persist in the caecal wall of the chicks at 72 h of post-challenge. The present study indicated that Φ st1 may serve as a potential biocontrol agent to reduce the Salmonella count in caecal content of chickens.
  18. Fulltext 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
    Ismail MI, Tan SW, Hair-Bejo M, Omar AR
    J Vet Sci, 2020 Nov;21(6):e76.
    PMID: 33263227 DOI: 10.4142/jvs.2020.21.e76
    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.

  19. Expression Profiles of Immune-Related Genes and Apoptosis Study of Avian Intraepithelial-Natural Killer Cells in Chickens Inoculated with Vaccine Strain of Newcastle Disease Virus (NDV) and Challenged with Virulent NDV
    Hamisu TM, Aliyu HB, Tan SW, Hair-Bejo M, Omar AR, Ideris A
    Avian Dis, 2022 Sep 22.
    PMID: 36198006 DOI: 10.1637/aviandiseases-D-22-00029
    In spite of the available information on the role of natural killer (NK) cells in several viral infections, the interactions between chicken intraepithelial-NK (IEL-NK) cells and Newcastle disease virus (NDV) are poorly understood. In this study, we investigated these interactions following the inoculation of chickens with NDV vaccine strain LaSota and subsequent challenge with velogenic NDV (vNDV) genotype VII (GVII) and VIII (GVIII), through quantification of IEL-NK cell's apoptosis and expression profiling of its surface receptors. Specific-pathogen-free chickens were randomly divided into six groups, as follows: one group of an uninfected control, one group infected with NDV LaSota, two groups each infected with either GVII or GVIII, and two groups inoculated with NDV LaSota and challenged with either GVII (LaSota-genotype VII [LSGVII]) or GVIII (LaSota-genotype VIII [LSGVIII]). Avian intraepithelial lymphocytes (IEL) were isolated from the duodenal loops, and CD3- cells were characterized. Immunophenotyping and apoptosis analysis of CD3-/CD25+/CD45+IEL NK cells were conducted using a flow cytometer. In addition, a gene expression study was conducted using real-time quantitative PCR. Data were analyzed using two-way analysis of variance. The results showed that vNDV GVII or GVIII caused apoptosis of IEL-NK cells; however, following inoculation of LSGVII or LSGVIII, the effect of vNDV GVII and GVIII to cause a reduction in the population of viable IEL-NK cells was significantly reduced. Furthermore, the expression profiles of activating receptors CD69, NK-lysin, and IFN-γ, were generally upregulated in chickens inoculated with LSGVII or LSGVIII. In contrast, B-NK, an inhibitory receptor, was downregulated in these treatment groups. In NDV GVII- and GVIII-challenged groups, however, B-NK was upregulated, whereas the other receptors were generally downregulated. The findings of this study showed that NDV vaccine strain LaSota may prevent apoptosis and cause upregulation of activating receptors of chicken IEL-NK cells in velogenic virus-challenged settings.
  20. Fulltext Farming of Plant-Based Veterinary Vaccines and Their Applications for Disease Prevention in Animals
    Liew PS, Hair-Bejo M
    Adv Virol, 2015;2015:936940.
    PMID: 26351454 DOI: 10.1155/2015/936940
    Plants have been studied for the production of pharmaceutical compounds for more than two decades now. Ever since the plant-made poultry vaccine against Newcastle disease virus made a breakthrough and went all the way to obtain regulatory approval, research to use plants for expression and delivery of vaccine proteins for animals was intensified. Indeed, in view of the high production costs of veterinary vaccines, plants represent attractive biofactories and offer many promising advantages in the production of recombinant vaccine proteins. Furthermore, the possibility of conducting immunogenicity and challenge studies in target animals has greatly exaggerated the progress. Although there are no edible plant-produced animal vaccines in the market, plant-based vaccine technology has great potentials. In this review, development, uses, and advantages of plant-based recombinant protein production in various expression platforms are discussed. In addition, examples of plant-based veterinary vaccines showing strong indication in terms of efficacy in animal disease prevention are also described.
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