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Background@#The commercially available Newcastle disease (ND) vaccines were developed based on Newcastle disease virus (NDV) isolates genetically divergent from field strains that can only prevent clinical disease, not shedding of virulent heterologous virus, highlighting the need to develop genotype-matched vaccines Objectives: This study examined the efficacy of the NDV genotype-matched vaccine, mIBS025 strain formulated in standard vaccine stabilizer, and in carboxymethyl sago starch-acid hydrogel (CMSS-AH) following vaccination via an eye drop (ED) and drinking water (DW). @*Methods@#A challenge virus was prepared from a recent NDV isolated from ND vaccinated flock. Groups of specific-pathogen-free chickens were vaccinated with mIBS025 vaccine strain prepared in a standard vaccine stabilizer and CMSS-AH via ED and DW and then challenged with the UPM/NDV/IBS362/2016 strain. @*Results@#Chickens vaccinated with CMSS-AH mIBS025 ED (group 2) developed the earliest and highest Hemagglutination Inhibition (HI) NDV antibody titer (8log 2 ) followed by standard mIBS025 ED (group 3) (7log 2 ) both conferred complete protection and drastically reduced virus shedding. By contrast, chickens vaccinated with standard mIBS025 DW (group 5) and CMSS-AH mIBS025 DW (group 4) developed low HI NDV antibody titers of 4log 2and 3log 2 , respectively, which correspondingly conferred only 50% and 60% protection and continuously shed the virulent virus via the oropharyngeal and cloacal routes until the end of the study at 14 dpc. @*Conclusions@#The efficacy of mIBS025 vaccines prepared in a standard vaccine stabilizer or CMSS-AH was affected by the vaccination routes. The groups vaccinated via ED had better protective immunity than those vaccinated via DW.
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Background@#The role of Toll-like receptors (TLRs) in a feline infectious peritonitis virus (FIPV) infection is not completely understood. @*Objectives@#This study examined the expression of TLR3, TLR7, TLR9, tumor necrosis factoralpha (TNF-α), interferon (IFN)-β, and interleukin (IL)-10 upon an FIPV infection in CrandellReese feline kidney (CRFK) cells and feline monocytes. @*Methods@#CRFK cells and monocytes from feline coronavirus (FCoV)-seronegative cats and FCoV-seropositive cats were infected with type II FIPV-79-1146. At four, 12, and 24 hours postinfection (hpi), the expression of TLR3, TLR7, TLR9, TNF-α, IFN-β, and IL-10, and the viral load were measured using reverse transcription quantitative polymerase chain reaction. Viral protein production was confirmed using immunofluorescence. @*Results@#FIPV-infected CRFK showed the upregulation of TLR9, TNF-α, and IFN-βexpression between 4 and 24 hpi. Uninfected monocytes from FCoV-seropositive cats showed lower TLR3 and TLR9 expression but higher TLR7 expression compared to uninfected monocytes from FCoV-seronegative cats. FIPV-infected monocytes from FCoV-seropositive cats downregulated TLR7 and TNF-α expression between 4 and 24 hpi, and 4 and 12 hpi, respectively. IFN-β was upregulated early in FIPV-infected monocytes from FCoV-seropositive cats, with a significant difference observed at 12 hpi compared to FCoV-seronegative cats.The viral load in the CRFK and FIPV-infected monocytes in both cohorts of cats was similar over time.ConclusionTLR7 may be the key TLR involved in evading the innate response against inhibiting TNF-α production. Distinct TLR expression profiles between FCoVseronegative and FCoV-seropositive cats were observed. The associated TLR that plays a role in the induction of IFN-β needs to be explored further.
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Background@#Inclusion body hepatitis (IBH) is an economically important viral disease primarily affecting broiler and breeder chickens. All 12 serotypes of fowl adenovirus (FAdV) can cause IBH. @*Objectives@#To characterize FAdV isolates based on phylogenetic analysis, and to study the pathogenicity of FAdV-8b in specific-pathogen-free (SPF) chickens following virus inoculation via oral and intramuscular (IM) routes. @*Methods@#Suspected organ samples were subjected to virus isolation and polymerase chain reaction (PCR) for FAdV detection. Hexon gene sequencing and phylogenetic analysis were performed on FAdV-positive samples for serotype identification. One FAdV-8b isolate, UPM/ FAdV/420/2017, was selected for fiber gene characterization and pathogenicity study and was inoculated in SPF chickens via oral and IM routes. @*Results@#The hexon gene phylogenetic analysis revealed that all isolates belonged to FAdV-8b. The fiber gene-based phylogenetic analysis of isolate UPM/FAdV/420/2017 supported the grouping of that isolate into FAdV species E. Pathogenicity study revealed that, chickens infected with UPM/FAdV/420/2017 via the IM route had higher clinical score values, higher percent mortality, higher degree of the liver lesions, higher antibody response (p < 0.05), and higher virus shedding amounts (p < 0.05) than those infected via the oral route. The highest virus copy numbers were detected in liver and gizzard. @*Conclusions@#FAdV-8b is the dominant FAdV serotype in Malaysia, and pathogenicity study of the FAdV-8b isolate UPM/FAdV/420/2017 indicated its ability to induce IBH in young SPF chickens when infected via oral or IM routes.
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Background@#Inclusion body hepatitis (IBH) is an economically important viral disease primarily affecting broiler and breeder chickens. All 12 serotypes of fowl adenovirus (FAdV) can cause IBH. @*Objectives@#To characterize FAdV isolates based on phylogenetic analysis, and to study the pathogenicity of FAdV-8b in specific-pathogen-free (SPF) chickens following virus inoculation via oral and intramuscular (IM) routes. @*Methods@#Suspected organ samples were subjected to virus isolation and polymerase chain reaction (PCR) for FAdV detection. Hexon gene sequencing and phylogenetic analysis were performed on FAdV-positive samples for serotype identification. One FAdV-8b isolate, UPM/ FAdV/420/2017, was selected for fiber gene characterization and pathogenicity study and was inoculated in SPF chickens via oral and IM routes. @*Results@#The hexon gene phylogenetic analysis revealed that all isolates belonged to FAdV-8b. The fiber gene-based phylogenetic analysis of isolate UPM/FAdV/420/2017 supported the grouping of that isolate into FAdV species E. Pathogenicity study revealed that, chickens infected with UPM/FAdV/420/2017 via the IM route had higher clinical score values, higher percent mortality, higher degree of the liver lesions, higher antibody response (p < 0.05), and higher virus shedding amounts (p < 0.05) than those infected via the oral route. The highest virus copy numbers were detected in liver and gizzard. @*Conclusions@#FAdV-8b is the dominant FAdV serotype in Malaysia, and pathogenicity study of the FAdV-8b isolate UPM/FAdV/420/2017 indicated its ability to induce IBH in young SPF chickens when infected via oral or IM routes.
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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.
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@#Introduction: Multidrug resistance bacteria is alarming worldwide. A lot of research were done and are ongoing to search for the best, convenient and economically affordable ways to fight them. With the latest genome editing tool; Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) technology, this research was performed to develop a novel strategy to genetically modify the genome and inhibit the growth of Klebsiella pneumoniae (UPM ESBLKP1), an Extended Spectrum Beta Lactamases (ESBL) organism. Methods: A CRISPR-Cas9 vector was constructed together with guide RNAs designed specifically for the targeted uppP gene, a gene responsible for bacterial cell growth and protection. Results: The growth and cell wall integrity of the modified Klebsiella pneumoniae (ΔUPM ESBLKP1) were significantly inhibited and reduced, respectively. Interestingly, wild type Klebsiella pneumoniae showed a normal growth curve while modified strains showed a faster doubling rate when supplemented with Luria-Bertani media. In contrast, slower growth rate of modified strain was observed in the M9 minimal media. This explained the higher doubling rate of mutants on nutrient rich medium earlier is being related to gene recovery. They grew slowly in the minimal media as they were adapting to a new environment while recovering the uppP gene and surviving, proving the success of its gene modification. Conclusion: The developed CRISPR-gRNA system was able to modify the targeted Klebsiella pneumoniae gene hence providing an opportunity to develop a new drug for Klebsiella pneumoniae infection as an alternative to antibiotics.
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Pasteurella multocida serotype B:2 causes hemorrhagic septicemia in cattle and buffalo. The invasion mechanism of the bacterium when invading the bloodstream is unclear. This study aimed to characterize the effects of immunomodulatory molecules, namely dexamethasone and lipopolysaccharide, on the invasion efficiency of P. multocida serotype B:2 toward bovine aortic endothelial cells (BAECs) and the involvement of actin microfilaments in the invasion mechanism. The results imply that treatment of BAECs with lipopolysaccharide at 100 ng/mL for 24 h significantly increases the intracellular bacteria number per cell (p < 0.01) compared with those in untreated and dexamethasone-treated cells. The lipopolysaccharide-treated cells showed a significant decrease in F-actin expression and an increase in G-actin expression (p < 0.001), indicating actin depolymerization of BAECs. However, no significant differences were detected in the invasion efficiency and actin filament reorganization between the dexamethasone-treated and untreated cells. Transmission electron microscopy showed that P. multocida B:2 resided in a vacuolar compartment of dexamethasone-treated and untreated cells, whereas the bacteria resided in cellular membrane of lipopolysaccharide-treated cells. The results suggest that lipopolysaccharide destabilizes the actin filaments of BAECs, which could facilitate the invasion of P. multocida B:2 into BAECs.
Subject(s)
Animals , Cattle , Actin Cytoskeleton , Actins , Bacteria , Buffaloes , Dexamethasone , Endothelial Cells , Hemorrhagic Septicemia , In Vitro Techniques , Membranes , Microscopy, Electron, Transmission , Pasteurella multocida , Pasteurella , SerogroupABSTRACT
The present study describes the development of DNA vaccines using the hemagglutinin-neuraminidase (HN) and fusion (F) genes from AF2240 Newcastle disease virus strain, namely pIRES/HN, pIRES/F and pIRES-F/HN. Transient expression analysis of the constructs in Vero cells revealed the successful expression of gene inserts in vitro. Moreover, in vivo experiments showed that single vaccination with the constructed plasmid DNA (pDNA) followed by a boost with inactivated vaccine induced a significant difference in enzyme-linked immunosorbent assay antibody levels (p < 0.05) elicited by either pIRES/F, pIRES/F+ pIRES/HN or pIRES-F/HN at one week after the booster in specific pathogen free chickens when compared with the inactivated vaccine alone. Taken together, these results indicated that recombinant pDNA could be used to increase the efficacy of the inactivated vaccine immunization procedure.
Subject(s)
Animals , Antibodies, Viral/blood , Chlorocebus aethiops , Chickens , HN Protein/genetics , Immunogenicity, Vaccine/immunology , Newcastle Disease/immunology , Newcastle disease virus/enzymology , Specific Pathogen-Free Organisms , Vaccines, DNA/genetics , Vaccines, Inactivated/immunology , Vero Cells , Viral Fusion Proteins/genetics , Viral Vaccines/geneticsABSTRACT
A Newcastle disease virus (NDV) isolate designated IBS002 was isolated from a commercial broiler farm in Malaysia. The virus was characterised as a virulent strain based on the multiple basic amino acid motif of the fusion (F) cleavage site 112RRRKGF117 and length of the C-terminus extension of the hemagglutinin-neuraminidase (HN) gene. Furthermore, IBS002 was classified as a velogenic NDV with mean death time (MDT) of 51.2 h and intracerebral pathogenicity index (ICPI) of 1.76. A genetic distance analysis based on the full-length F and HN genes showed that both velogenic viruses used in this study, genotype VII NDV isolate IBS002 and genotype VIII NDV isolate AF2240-I, had high genetic variations with genotype II LaSota vaccine. In this study, the protection efficacy of the recombinant genotype VII NDV inactivated vaccine was also evaluated when added to an existing commercial vaccination program against challenge with velogenic NDV IBS002 and NDV AF2240-I in commercial broilers. The results indicated that both LaSota and recombinant genotype VII vaccines offered full protection against challenge with AF2240-I. However, the LaSota vaccine only conferred partial protection against IBS002. In addition, significantly reduced viral shedding was observed in the recombinant genotype VII-vaccinated chickens compared to LaSota-vaccinated chickens.
Subject(s)
Animals , Amino Acids, Basic , Chickens , Genetic Variation , Genotype , Malaysia , Newcastle disease virus , Newcastle Disease , Vaccination , Vaccines , Virulence , Virus SheddingABSTRACT
BACKGROUND: Prolonged standing has been hypothesized as a vital contributor to discomfort and muscle fatigue in the workplace. The objective of this study was to develop a decision support system that could provide systematic analysis and solutions to minimize the discomfort and muscle fatigue associated with prolonged standing. METHODS: The integration of object-oriented programming and a Model Oriented Simultaneous Engineering System were used to design the architecture of the decision support system. RESULTS: Validation of the decision support system was carried out in two manufacturing companies. The validation process showed that the decision support system produced reliable results. CONCLUSION: The decision support system is a reliable advisory tool for providing analysis and solutions to problems related to the discomfort and muscle fatigue associated with prolonged standing. Further testing of the decision support system is suggested before it is used commercially.
Subject(s)
Fatigue , Ergonomics , Muscle FatigueABSTRACT
OBJECTIVES: The objectives of this study were to determine the psychological fatigue and analyze muscle activity of production workers who are performing processes jobs while standing for prolonged time periods. METHODS: The psychological fatigue experienced by the workers was obtained through questionnaire surveys. Meanwhile, muscle activity has been analyzed using surface electromyography (sEMG) measurement. Lower extremities muscles include: erector spinae, tibialis anterior, and gastrocnemius were concurrently measured for more than five hours of standing. Twenty male production workers in a metal stamping company participated as subjects in this study. The subjects were required to undergo questionnaire surveys and sEMG measurement. RESULTS: Results of the questionnaire surveys found that all subjects experienced psychological fatigue due to prolonged standing jobs. Similarly, muscle fatigue has been identified through sEMG measurement. Based on the non-parametric statistical test using the Spearman's rank order correlation, the left erector spinae obtained a moderate positive correlation and statistically significant (rs = 0.552, p < 0.05) between the results of questionnaire surveys and sEMG measurement. CONCLUSION: Based on this study, the authors concluded that prolonged standing was contributed to psychological fatigue and to muscle fatigue among the production workers.
Subject(s)
Humans , Male , Electromyography , Fatigue , Lower Extremity , Muscle Fatigue , Muscles , Surveys and QuestionnairesABSTRACT
The ability of a heat-inactivated whole virus from a highly virulent infectious bursal disease virus (hvIBDV) and VP2 protein from hvIBDV expressed in E. coli provided protection against a hvIBDV challenge in specificpathogen- free (SPF) chickens. Six out of seven chickens that were injected three times with crude VP2 protein developed significant antibody titer against IBDV. However, only four out of the seven chickens survived the hvIBDV challenge. Despite showing low antibody titer profiles, all chickens immunized with the heat-inactivated whole virus also survived the challenged with hvIBDV. However, all of these chickens had bursal atrophy and mild to moderate depletion of lymphocytes. Thus, antibodies raised against IBDV VP2 protein expressed in E. coli and denatured IBDV proteins induced some degree of protection against mortality but not against bursal damage following challenge with hvIBDV.