16 results on '"Nik M. Faiz"'
Search Results
2. Replication of Marek’s disease vaccines in turkey embryos and their effect on TLR-3 and IFN-γ transcripts
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E Gonder, J Bremen, W N Shaw, Isabel M. Gimeno, Nik M. Faiz, A Turner, K Robbins, and Aneg L. Cortes
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Marek's disease ,General Immunology and Microbiology ,biology ,040301 veterinary sciences ,0402 animal and dairy science ,Wild type ,Spleen ,Embryo ,04 agricultural and veterinary sciences ,In ovo ,biology.organism_classification ,040201 dairy & animal science ,Virology ,0403 veterinary science ,Vaccination ,medicine.anatomical_structure ,Immune system ,Food Animals ,medicine ,Animal Science and Zoology ,Flock - Abstract
Understanding the pathogenesis of herpesvirus of turkeys (HVT) in its natural host is necessary before recombinant HVT (rHVT) can be used efficiently in turkey flocks. The objectives of this study were to evaluate when commercial turkey flocks get infected with wild type HVT, to study replication of HVT (conventional and recombinant rHVT-Newcastle disease, rHVT-ND) and other Marek's disease (MD) vaccines (SB-1 and CVI988) in turkey embryonic tissues, and to evaluate the expression of TLR-3 and IFN-γ in the lung and spleen of one-day-old turkeys after in ovo vaccination with MD vaccines. Our results demonstrated that commercial turkeys got exposed to wild type HVT within the first days of life; therefore, there is a potential of interaction between wild type HVT and rHVT when administered at day of age. On the other hand, all evaluated vaccines (especially HVT and rHVT-ND) replicated very well in turkey embryonic tissues. In ovo vaccination with HVT and CVI988 increased transcription of TLR-3 in the spleen of one-day-old turkeys. However, no effect on the transcription of TLR-3 or IFN-γ in the lungs and IFN-γ in the spleen in newly hatched turkeys was detected in the present study. Because of the limitations of evaluated genes, timepoints, and studied tissues, future studies are warranted to better understand the effect of MD vaccines on the turkey embryo immune responses.RESEARCH HIGHLIGHTS Commercial turkey flocks get infected with wild type HVT within the first days of life.HVT and rHVT replicates readily in turkey embryonic tissues.SB-1 and CVI988 also replicate in turkey embryonic tissues, but at lower rates than HVT and rHVT.HVT and CVI988 increase transcription of TLR-3 in the spleen.
- Published
- 2021
3. Rapid detection of colistin-resistant Enterobacterales using the resazurin reduction-based assay
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Nik M Faiz, Latiffah Hassan, Nur Indah Ahmad, Zunita Zakaria, Bashiru Garba, and Rezaul Karim
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0301 basic medicine ,Microbiology (medical) ,Chemistry ,Colistin ,030106 microbiology ,Immunology ,Resazurin ,Pharmacology ,Rapid detection ,Microbiology ,QR1-502 ,Colistin resistance ,Reduction (complexity) ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Xanthenes ,Enterobacterales ,Oxazines ,medicine ,Immunology and Allergy ,030212 general & internal medicine ,medicine.drug - Published
- 2021
4. Characterization of Md5-BAC-REV-LTR virus as Marek's disease vaccine in commercial meat-type chickens: protection and immunosuppression
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Aly M. Fadly, C Ellington, Nik M. Faiz, Jody K. Mays, Robert F. Silva, Isabel M. Gimeno, and Aneg L. Cortes
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Serotype ,animal structures ,Meat ,viruses ,medicine.medical_treatment ,Virulence ,Virus ,Food Animals ,medicine ,Animals ,Marek Disease Vaccines ,Herpesvirus 2, Gallid ,Immunosuppression Therapy ,Marek's disease ,Reticuloendotheliosis virus ,General Immunology and Microbiology ,biology ,Terminal Repeat Sequences ,Immunosuppression ,biology.organism_classification ,Virology ,Vaccination ,biology.protein ,Animal Science and Zoology ,Antibody ,Chickens - Abstract
Md5-BAC-REV-LTR is a recombinant Marek's disease virus (MDV), with an insertion of the long terminal repeat (LTR) of reticuloendotheliosis virus (REV) into the genome of the highly virulent MDV strain rMd5. It has been shown that Md5-BAC-REV-LTR does not induce tumours and confers high protection against challenge with MDV in 15 × 7 chickens. The objective of the present study was to evaluate the protection and safety (in terms of oncogenicity and immunosuppression) of Md5-BAC-REV-LTR in commercial meat-type chickens bearing maternal antibodies against MDV. Our results show that sub-cutaneous administration of Md5-BAC-REV-LTR at 1 day of age conferred high protection (protection index PI = 84.2) against an early challenge (1 day) by contact exposure to shedder birds infected with the vv+ MDV 648A strain. In such stringent challenge conditions, Md5-BAC-REV-LTR was more protective than a commercial CVI988 (PI = 12.4) and similar to the experimental vaccine Md5-BACΔmeq (PI = 92.4). Furthermore, Md5-BAC-REV-LTR did not induce either tumours or immunosuppression in this study. Immunosuppression was evaluated by the relative lymphoid organ weights and also by the ability of the vaccine to induce late-MDV-induced immunosuppression associated with reactivation of the virus. This study shows that Md5-BAC-REV-LTR has the potential to be used as a MD vaccine and is highly protective against early challenge with vv+ MDV. RESEARCH HIGHLIGHTSMd5-BAC-REV-LTR is highly protective against early challenge with vv+ MDV in commercial meat-type chickens.Md5-BAC-REV-LTR does not cause early immunosuppression.Md5-BAC-REV-LTR does not cause late immunosuppression.Unlike other serotype 1 vaccines, Md5-BAC-REV-LTR is not detected in feather pulp at 7 days post vaccination.
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- 2021
5. Antimicrobial minimum inhibitory concentration of Mycoplasma gallisepticum: a systematic review
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Nik M Faiz, H. Taiyari, Zunita Zakaria, and Jalila Abu
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0301 basic medicine ,Mycoplasma gallisepticum ,Veterinary medicine ,medicine.drug_class ,030106 microbiology ,Antibiotics ,antimicrobial agents ,Tylosin ,minimum inhibitory concentration ,SF1-1100 ,Food processing and manufacture ,03 medical and health sciences ,Minimum inhibitory concentration ,chemistry.chemical_compound ,Antibiotic resistance ,systematic review ,medicine ,Enrofloxacin ,antimicrobial susceptibility profile ,biology ,Broth microdilution ,TP368-456 ,Antimicrobial ,biology.organism_classification ,Animal culture ,030104 developmental biology ,chemistry ,Animal Science and Zoology ,medicine.drug - Abstract
Summary The aptitude of Mycoplasma gallisepticum (MG) for changing its surface proteins allows the pathogen to reduce the efficacy of antimicrobial agents, especially those targeting surface proteins. Although antibiotic treatment cannot be a solution for the eradication of avian mycoplasmosis, it can be considered a good option to minimize the number of deaths. One of the challenges of antibiotic treatments is the development of antimicrobial resistance (AMR) among field isolates. Monitoring the antimicrobial susceptibility profile of field isolates can be a practical way of avoiding AMR. Thus, various tests have been developed to determine the antimicrobial susceptibility profile of field isolates. A modified broth microdilution minimum inhibitory concentration (MIC) test has been regularly used to measure the antimicrobial susceptibility profile of MG field isolates. Numerous studies have reported an increase in the number of antibiotic-resistant field isolates of MG. Therefore, this study presents a systematic review on antimicrobial MIC values of MG isolates to gather recent knowledge and investigate the prevalence and distribution of AMR among MG field isolates. A thorough search was conducted for related studies throughout 3 electronic databases. Altogether, 23 studies were identified as eligible studies and were used for further analysis. The results showed that enrofloxacin, oxytetracycline, and tylosin had the highest number of resistant isolates in most of the geographical distributions, respectively. Minimum inhibitory concentrations of these antibiotics need to be determined regularly to optimize treatment dosages.
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- 2021
6. Molecular characterisation and antibiotic sensitivity profile of Pasteurella multocida isolated from poultry farms in Malaysia
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Zunita Zakaria, Jalila Abu, Mohammad A. Sabsabi, and Nik M. Faiz
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Serotype ,Veterinary medicine ,Pasteurella multocida ,General Veterinary ,Tetracycline ,Antibiotic sensitivity ,animal diseases ,PFGE ,Biology ,biology.organism_classification ,antimicrobial susceptibility ,medicine ,Pulsed-field gel electrophoresis ,Enrofloxacin ,Multilocus sequence typing ,Fowl cholera ,medicine.drug ,MLST - Abstract
Fowl cholera has caused significant economic losses in many poultry producing countries worldwide. In Malaysia, outbreaks of fowl cholera are frequently reported and encountered in different types of poultry productions. The objective of this study was to characterise 13 avianPasteurella multocida,isolated from fowl cholera outbreaks in Central Peninsular Malaysia in the period between 2000 and 2018. The isolates were subjected to multiplex polymerase chain reaction (PCR) for capsular serotyping, disc diffusion method for antimicrobial susceptibility profiles, and molecular genotyping using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). The capsular serotyping showed all 13Pasteurella multocidaisolates belonging to capsular serotype A. The antimicrobial susceptibility showed several multidrug resistance strains among theP. multocidaisolates. All the isolates were resistant to erythromycin (100%), streptomycin (68%), tetracycline (37%), enrofloxacin (37%), florfenicol (23%), penicillin G (14%), gentamicin (14%), and amoxicillin (14%). The PFGE analysis clustered the isolates into three clones. Group A included isolates with a similarity of 87% from the year 2000, 2013, and 2018. Three sequence types were identified using MLST typing namely, ST129, ST231, and ST355. The ST355 was assigned for the first time in the Rural Industries Research and Development Corporation (RIRDC) database. Besides, ST129 has been reported in India, China, and Sri Lanka, which highlights the possibility of transmission between Asian countries. This study provides an insight into epidemiological information ofPasteurella multocidathat causes fowl cholera outbreaks in the central region of Peninsular Malaysia.
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- 2021
7. Evaluation of factors influencing the development of late Marek’s disease virus-induced immunosuppression: virus pathotype and host sex
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Oscar J. Fletcher, Aneg L. Cortes, Isabel M. Gimeno, Nik M. Faiz, James S. Guy, and Thomas Cimino
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Male ,0301 basic medicine ,animal structures ,animal diseases ,viruses ,medicine.medical_treatment ,Virulence ,Virus ,Pathogenesis ,03 medical and health sciences ,Sex Factors ,Food Animals ,immune system diseases ,hemic and lymphatic diseases ,Marek Disease ,medicine ,Animals ,Marek's disease ,General Immunology and Microbiology ,biology ,Viral Vaccines ,Immunosuppression ,medicine.disease ,biology.organism_classification ,Virology ,Specific Pathogen-Free Organisms ,Lymphoma ,Mardivirus ,MicroRNAs ,030104 developmental biology ,Lymphatic system ,Gene Expression Regulation ,biology.protein ,Female ,Animal Science and Zoology ,Antibody ,Chickens - Abstract
Marek's disease virus (MDV) is a herpesvirus that induces lymphoma and immunosuppression in chickens. MDV-induced immunosuppression (MDV-IS) is complex and can be divided into two phases: early-MDV-IS associated with cytolytic infection in the lymphoid organs in chickens lacking maternal antibodies against MDV (MAbs) and late-MDV-IS that appears later in the pathogenesis and occurs even in chickens bearing MAbs. We have recently developed a model to reproduce late-MDV-IS under laboratory conditions. This model evaluates late-MDV-IS indirectly by assessing the effect of MDV infection on the efficacy of infectious laryngotracheitis (ILT) vaccines against challenge with ILT virus. In the present study, we have used this model to investigate the role of two factors (MDV pathotype and host sex) on the development of late-MDV-IS. Five MDV strains representing three different pathotypes: virulent (vMDV; 617A, GA), very virulent (vvMDV; Md5), and very virulent plus (vv+MDV; 648A, 686), were evaluated. Only vv+ strains were able to induce late-MDV-IS. An immunosuppression rank (IS-rank) was established based on the ability of MDV to reduce the efficacy of chicken embryo origin vaccine (values go from 0 to 100, with 100 being the highest immunosuppressive ability). The IS-rank of the evaluated MDV strains ranged from 5.97 (GA) to 20.8 (617A) in the vMDV strains, 5.97 to 16.24 in the vvMDV strain Md5, and 39.08 to 68.2 in the vv+ strains 648A and 686. In this study both male and female chickens were equally susceptible to MDV-IS by vv+MDV 686. Our findings suggest that late-MDV-IS is a unique feature of vv+ strains.
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- 2017
8. Salmonella in native 'village' chickens (Gallus domesticus): prevalence and risk factors from farms in South-Central Peninsular Malaysia
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Saleha Abdul Aziz, Jalila Abu, Latiffah Hassan, Saleh Mohammed Jajere, Nik M Faiz, Zunita Zakaria, and Fauziah Nordin
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Serotype ,Salmonella ,Veterinary medicine ,Farms ,prevalence ,Health benefits ,Biology ,Southeast asian ,medicine.disease_cause ,village chicken ,03 medical and health sciences ,Risk Factors ,medicine ,Animals ,Microbiology and Food Safety ,Water tanks ,Poultry Diseases ,030304 developmental biology ,0303 health sciences ,Salmonella Infections, Animal ,Animal health ,Peninsular Malaysia ,0402 animal and dairy science ,Broiler ,Malaysia ,04 agricultural and veterinary sciences ,General Medicine ,040201 dairy & animal science ,risk factor ,Animal Science and Zoology ,Flock ,Chickens - Abstract
Village chicken or Ayam Kampung, common to Southeast Asian countries, has always been regarded as superior in comparison to commercial broiler chicken in terms of wholesomeness and health benefits. The current study investigates the prevalence and risk factors of Salmonella among village chicken flocks from the central and southern states of Peninsular Malaysia. A total of 35 village flocks were sampled from Selangor (n = 19), Melaka (n = 10), Johor (n = 4), and Negeri Sembilan (n = 2). In total, 1,042 samples were collected; these included cloacal swabs (n = 675), eggs (n = 62), pooled drinking water (n = 175), pooled feeds (n = 70), and pooled flies (n = 60). Isolation of Salmonella from cloacal swabs, poultry drinking water, and feeds was carried out according to the protocols and recommendations of the World Organization for Animal Health (OIE) terrestrial manual. The prevalence of Salmonella at an individual bird-level was 2.5% (17/675, 95% CI: 1.6 to 4.0). All eggs screened were negative; in the case of environmental samples, however, Salmonella was detected in 5.14% (9/175), 7.14% (5/70), and 5.0% (3/60) for water, feed, and flies, respectively. A total of 34 isolates and 8 Salmonella serotypes were identified. Weltevreden (20.6%) was the most common, followed by Typhimurium and Agona (17.6%), Albany and Enteritidis (8.8%), Molade (5.9%), Corvallis and Schleissheim (2.9%), and others grouped as Salmonella spp. (11.8%). Multivariable logistic regression models revealed that Salmonella positivity among flocks could be strongly predicted by storage of feeds (uncovered feeds; OR = 10.38; 95% CI: 1.25 to 86.39; p = 0.030) and uncovered water tanks (uncovered tank; OR = 6.43; 95% CI: 1.02 to 40.60; p = 0.048). The presence of Salmonella in village chickens in the study area was lower than that of commercial chickens in Malaysia.
- Published
- 2019
9. Differential attenuation of Marek's disease virus-induced tumours and late-Marek's disease virus-induced immunosuppression
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Nik M. Faiz, Aneg L. Cortes, Isabel M. Gimeno, Sanjay M. Reddy, and James S. Guy
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0301 basic medicine ,animal structures ,Lymphoma ,040301 veterinary sciences ,Carcinogenesis ,animal diseases ,viruses ,medicine.medical_treatment ,Clone (cell biology) ,Virulence ,Spleen ,Antibodies, Viral ,Virus ,0403 veterinary science ,03 medical and health sciences ,Immune system ,Herpesvirus 1, Gallid ,Species Specificity ,immune system diseases ,hemic and lymphatic diseases ,Virology ,medicine ,Marek Disease ,Animals ,Herpesvirus 2, Gallid ,Marek's disease ,biology ,Oncogene ,Immunologic Deficiency Syndromes ,Immunosuppression ,Viral Vaccines ,04 agricultural and veterinary sciences ,biology.organism_classification ,Immunity, Humoral ,MicroRNAs ,030104 developmental biology ,medicine.anatomical_structure ,RNA, Viral ,Female ,Chickens - Abstract
Marek’s disease virus (MDV) is a herpesvirus that induces lymphoma and a variety of non-neoplastic syndromes in chickens. Furthermore, very virulent plus (vv+) MDVs induce a form of immunosuppression (late-MDV-IS) that might involve both neoplastic and non-neoplastic mechanisms. The objective of this study was to evaluate whether the attenuation of MDV-induced tumours and late-MDV-IS occurs simultaneously or can be dissociated. The immunosuppressive ability of three viruses derived from vv+ MDV strain 686 (wild-type 686, the somewhat attenuated molecular clone 686-BAC, and the nononcogenic molecular clone lacking the two copies of the oncogene meq 686-BACΔMEQ) was evaluated. Late-MDV-IS was evaluated indirectly by assessing the negative effect of MDV strains on the protection conferred by infectious laryngotracheitis (ILT) vaccines. Our results showed that the ability to induce late-MDV-IS was attenuated before the ability to induce tumours. Strain 686 induced both tumours and late-MDV-IS, 686-BAC induced tumours but did not induce late-MDV-IS and 686-BACΔMEQ did not induce either tumours or late-MDV-IS. Further comparison of strains 686 and 686-BAC revealed that strain 686 reduced the humoral immune responses to ILTV (1132 vs 2167) more severely, showed higher levels of meq transcripts (2.1E+09 vs 4.98E+8) and higher expression of MDV microRNAs (mdv1-miR-M4-5p and mdv1-miR-M2-3p) in the spleen, and further reduced the percentage of CD45+-MHC-I+splenocytes (13 vs32 %) compared to molecular clone 686-BAC. This study suggests that the immunosuppressive ability of MDV might follow a continuous spectrum and only the most virulent MDVs can overcome a certain threshold level and induce clinical MDV-IS in the ILT model.
- Published
- 2018
10. Evaluation of the Protection Efficacy of a Serotype 1 Marek's Disease Virus-Vectored Bivalent Vaccine Against Infectious Laryngotracheitis and Marek's Disease
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Byron A. Hernandez-Ortiz, Aneg L. Cortes, Nik M. Faiz, Isabel M. Gimeno, Henry D. Hunt, Robert F. Silva, and James S. Guy
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Serotype ,Mardivirus ,Pilot Projects ,Virus Replication ,Virus ,Microbiology ,law.invention ,Herpesvirus 1, Gallid ,Food Animals ,law ,Marek Disease ,Vaccines, DNA ,Animals ,Marek's disease ,General Immunology and Microbiology ,biology ,Viral Vaccine ,Viral Vaccines ,Herpesviridae Infections ,biology.organism_classification ,Fowlpox virus ,Virology ,Viral replication ,Recombinant DNA ,Female ,Animal Science and Zoology ,Chickens - Abstract
Laryngotracheitis (LT) is a highly contagious respiratory disease of chickens that produces significant economic losses to the poultry industry. Traditionally, LT has been controlled by administration of modified live vaccines. In recent years, the use of recombinant DNA-derived vaccines using turkey herpesvirus (HVT) and fowlpox virus has expanded, as they protect not only against the vector used but also against LT. However, HVT-based vaccines confer limited protection against challenge, with emergent very virulent plus Marek's disease virus (vv+MDV). Serotype 1 vaccines have been proven to be the most efficient against vv+MDV. In particular, deletion of oncogene MEQ from the oncogenic vvMDV strain Md5 (BACδMEQ) resulted in a very efficient vaccine against vv+MDV. In this work, we have developed two recombinant vaccines against MD and LT by using BACδMEQ as a vector that carries either the LT virus (LTV) gene glycoprotein B (gB; BACΔMEQ-gB) or LTV gene glycoprotein J (gJ; BACδMEQ-gJ). We have evaluated the protection that these recombinant vaccines confer against MD and LT challenge when administered alone or in combination. Our results demonstrated that both bivalent vaccines (BACΔMEQ-gB and BACδMEQ-gJ) replicated in chickens and were safe to use in commercial meat-type chickens bearing maternal antibodies against MDV. BACΔMEQ-gB protected as well as a commercial recombinant (r)HVT-LT vaccine against challenge with LTV. However, BACδMEQ-gJ did not protect adequately against LT challenge or increase protection conferred by BACΔMEQ-gB when administered in combination. On the other hand, both BACΔMEQ-gB and BACδMEQ-gJ, administered alone or in combination, protected better against an early challenge with vv+MDV strain 648A than commercial strains of rHVT-LT or CVI988. Our results open a new avenue in the development of recombinant vaccines by using serotype 1 MDV as vectors.
- Published
- 2015
11. Early infection with Marek's disease virus can jeopardize protection conferred by laryngotracheitis vaccines: a method to study MDV-induced immunosuppression
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Enrique Montiel, Aneg L. Cortes, Isabel M. Gimeno, Melissa A. West, Nik M. Faiz, James S. Guy, and Oscar J. Fletcher
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0301 basic medicine ,animal structures ,040301 veterinary sciences ,animal diseases ,viruses ,medicine.medical_treatment ,Virus ,0403 veterinary science ,03 medical and health sciences ,Tracheitis ,Food Animals ,immune system diseases ,hemic and lymphatic diseases ,medicine ,Marek Disease ,Animals ,Herpesvirus 2, Gallid ,Immunosuppression Therapy ,Marek's disease ,General Immunology and Microbiology ,biology ,Viral Vaccine ,Vaccination ,Models, Immunological ,Immunosuppression ,Viral Vaccines ,04 agricultural and veterinary sciences ,medicine.disease ,biology.organism_classification ,Virology ,Specific Pathogen-Free Organisms ,030104 developmental biology ,Lymphatic system ,Immunology ,biology.protein ,Animal Science and Zoology ,Female ,Antibody ,Chickens - Abstract
Marek's disease virus (MDV) is a herpesvirus that induces lymphomas and immunosuppression in chickens. MDV-induced immunosuppression (MDV-IS) is divided into two phases: early-MDV-IS occurring mainly in chickens lacking maternal antibodies (MAb) against MDV and associated with lymphoid organ atrophy; and late-MDV-IS occurring once MDV enters latency and during tumour development. Our objectives were to document the impact of late-MDV-IS on commercial poultry (meat-type chickens bearing MAb against MDV and that were vaccinated or unvaccinated against MD) and to optimize a model to study late-MDV-IS under laboratory conditions. The impact of late-MDV-IS was evaluated by assessing the effect of early infection (day of age) with a very virulent plus MDV (vv+MDV) on the efficacy of chicken-embryo-origin (CEO) infectious laryngotracheitis (ILT) virus vaccine against ILT challenge. The CEO ILT vaccine was administered in water at 14 days of age and ILT virus (ILTV) challenge was done intratracheally at 30 days of age. Development of ILT was monitored by daily evaluation of clinical signs, development of gross and histological lesions in trachea, and quantification of ILTV transcripts in trachea. Infection with vv+MDV strain 648A resulted in total abrogation of protection conferred by the CEO vaccine against ILTV challenge even in chickens vaccinated at 1 day of age with either HVT, HVT+SB-1, or CVI988. Chickens exposed to vv+MDV prior to vaccination with CEO ILTV vaccine had similar (P
- Published
- 2016
12. Efficacy of Various HVT Vaccines (Conventional and Recombinant) Against Marek's Disease in Broiler Chickens: Effect of Dose and Age of Vaccination
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Isabel M. Gimeno, Aneg L. Cortes, Tarsicio Villalobos, Taylor Barbosa, Nik M. Faiz, and H. Badillo
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0301 basic medicine ,Serotype ,Veterinary medicine ,animal structures ,040301 veterinary sciences ,Marek Disease Vaccines ,Dose-Response Relationship, Immunologic ,Biology ,In ovo ,law.invention ,0403 veterinary science ,Herpesvirus 1, Meleagrid ,03 medical and health sciences ,Food Animals ,law ,Marek Disease ,Animals ,Poultry Diseases ,Marek's disease ,Vaccines, Synthetic ,General Immunology and Microbiology ,Vaccination ,Broiler ,Age Factors ,04 agricultural and veterinary sciences ,biology.organism_classification ,Virology ,030104 developmental biology ,Recombinant DNA ,Animal Science and Zoology ,Female ,Chickens - Abstract
Herpesvirus of turkeys (HVT) has been successfully used as a Marek's disease (MD) vaccine for more than 40 yr. Either alone (broiler chickens) or in combination with vaccines of other serotypes (broilers, broiler breeders, and layers), HVT is used worldwide. In recent years, several vector vaccines based on HVT (rHVT) have been developed. At present, there are both conventional HVT and rHVTs in the market, and it is unknown if all of them confer the same level of protection against MD. The objective of this study was to further characterize the protection conferred by two conventional HVTs (HVT-A and HVT-B) and three recombinant HVTs (rHVT-B, rHVT-C, and rHVT-D) against MD in broiler chickens. In a first study we evaluated the efficacy of two conventional HVTs (HVT-A and HVT-B) administered at different doses (475, 1500, and 4000 PFU) at day of age on the ability to protect against an early challenge with very virulent plus strain 645. In a second experiment we evaluated the protection ability of several HVTs (both conventional and recombinant) when administered in ovo at a dose of 1500 PFU using the same challenge model. Our results show that each HVT product is unique, regardless of being conventional or recombinant, in their ability to protect against MD and might require different PFUs to achieve its maximum efficacy. In Experiment 1, HVT-A at 4000 PFU conferred higher protection (protection index [PI] = 63) than any of the other vaccine protocols (PI ranging from 36 to 47). In Experiment 2, significant differences were found among vaccine protocols with PI varying from 66 (HVT-A) to 15 (rHVT-D). Our results show that each HVT is unique and age at vaccination and vaccine dose greatly affected vaccine efficacy. Furthermore, they highlight the need of following manufacturer's recommendations.
- Published
- 2016
13. Efficacy of various Marek's disease vaccines protocols for prevention of Marek's disease virus-induced immunosuppression
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Aneg L. Cortes, James S. Guy, Jonathan E. Fogle, Nik M. Faiz, and Isabel M. Gimeno
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0301 basic medicine ,Serotype ,animal structures ,040301 veterinary sciences ,Marek Disease Vaccines ,viruses ,animal diseases ,medicine.medical_treatment ,In ovo ,Virus ,0403 veterinary science ,03 medical and health sciences ,Immune system ,immune system diseases ,hemic and lymphatic diseases ,Neoplasms ,medicine ,Immune Tolerance ,Marek Disease ,Animals ,Poultry Diseases ,Marek's disease ,General Veterinary ,General Immunology and Microbiology ,biology ,business.industry ,Vaccination ,Public Health, Environmental and Occupational Health ,Immunosuppression ,04 agricultural and veterinary sciences ,biology.organism_classification ,Virology ,030104 developmental biology ,Infectious Diseases ,Immunology ,Molecular Medicine ,Female ,business ,Chickens - Abstract
Marek's disease virus (MDV) induces tumors and severe immunosuppression in chickens. MDV-induced immunosuppression (MDV-IS) is very complex and difficult to study. In particular, the late MDV-IS (late-MDV-IS) is of great concern since it can occur in the absence of lymphoid organ atrophy or gross tumors. We have recently developed a model to reproduce late-MDV-IS under laboratory conditions. This model measures MDV-IS indirectly by assessing the effect of MDV infection on the efficacy of infectious laryngotracheitis (ILT) vaccination; hence the name late-MDV-IS ILT model. In this study, we have used the late-MDV-IS ILT model to evaluate if MD vaccination can protect against late-MDV-IS. One experiment was conducted to determine whether serotype 1 MD vaccines (CVI988 and Md5ΔMEQ) could induce late-MDV-IS by themselves. Three additional experiments were conducted to evaluate efficacy of different MD vaccines (HVT, HVT+SB-1, CVI988, and Md5ΔMEQ) and different vaccine protocols (day-old vaccination, in ovo vaccination, and double vaccination) against late-MDV-IS. Our results show that none of the currently used vaccine protocols (HVT, HVT+SB-1, or CVI988 administered at day of age, in ovo, or in double vaccination protocols) protected against late-MDV-IS induced by vv+MDV strains 648A and 686. Experimental vaccine Md5ΔMEQ administered subcutaneously at one day of age was the only vaccine protocol that significantly reduced late-MDV-IS induced by vv+MDV strain 686. This study demonstrates that currently used vaccine protocols confer high levels of protection against MDV-induced tumors (protection index=100), but do not protect against late-MDV-IS; thus, commercial poultry flocks could suffer late-MDV-IS even in complete absence of tumors. Our results suggest that MDV-IS might not be related to the development of tumors and novel control methods are needed. Further evaluation of the experimental vaccine Md5ΔMEQ might shed light on protective mechanisms against late-MDV-IS.
- Published
- 2016
14. Heterotopic Implantation of Autologous Bone Marrow in Rock Pigeons (Columba livia): Possible Applications in Avian Bone Grafting
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Mohd Zuki Abu Bakar, Zeenathul Nazariah Allaudin, Nik M. Faiz, Mojgan Nazari, Jalila Abu, and M. Reza Sanaei
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medicine.medical_specialty ,Pathology ,Bone Transplantation ,Angiogenesis ,business.industry ,Ossification ,Ossification, Heterotopic ,Tibiotarsus ,medicine.medical_treatment ,Mesenchymal stem cell ,General Medicine ,Bone grafting ,Surgery ,Neovascularization ,medicine.anatomical_structure ,medicine ,Animals ,Bone marrow ,Implant ,medicine.symptom ,Columbidae ,Muscle, Skeletal ,Small Animals ,business ,Bone Marrow Transplantation - Abstract
Autologous bone marrow, alone or as a composite marrow graft, has received much attention in various species. To assess the potential osteogenicity of autologous, extramedullary bone marrow implants in an avian model, 24 adult pigeons (Columba livia) were given intramuscular implantations of autologous marrow aspirated from the medial tibiotarsus. Birds were euthanatized at 1, 4, 6, 8, 10, and 12 weeks after surgery to evaluate whether ectopic bone had formed at the implant sites. Primary evaluations by in situ radiography and postmortem histologic examinations showed no evidence of bone formation. Further evaluation with histologic scores and histomorphometry revealed a significantly increased rate of angiogenesis at the implant sites by the sixth and tenth week postimplantation (P < .05). No significant differences between the treatment and control sites were present at any other endpoints. Results of this study show that, although autologous bone marrow lacks heterotopic osteogenic potentials in this avian model, it could still function as a useful adjunct to routine bone grafting techniques because of its unique capabilities to promote early angiogenesis.
- Published
- 2011
15. Evaluation of Factors Influencing Efficacy of Vaccine Strain CVI988 Against Marek's Disease in Meat-Type Chickens
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Aneg L. Cortes, Nik M. Faiz, Tarsicio Villalobos, Isabel M. Gimeno, and Taylor Barbosa
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Marek's disease ,animal structures ,General Immunology and Microbiology ,biology ,Lymphoid Tissue ,Viral Vaccine ,Virulence ,Viral Vaccines ,Disease ,Genome, Viral ,Viral Load ,biology.organism_classification ,In ovo ,Real-Time Polymerase Chain Reaction ,Virology ,Virus ,Vaccination ,Food Animals ,Immunology ,Marek Disease ,Animals ,Animal Science and Zoology ,Viral load ,Chickens - Abstract
Marek's disease (MD) strain CVI988 is the most-protective commercially available vaccine against very virulent plus (vv+) Marek's disease virus (MDV). However, its use in meat-type chickens has been controversial. While several countries have been using CVI988 for more than 40 yr, others do not authorize its use or it is restricted mainly to layers. The use of CVI988 in meat-type chickens will be necessary in the future in areas where other vaccine protocols fail. The objective of this study was to evaluate factors (vaccine dose, vaccine origin, chicken genetics, age and route of vaccination, and combination with other MD vaccines) influencing the efficacy of CVI988 against MD in meat-type chickens. Three animal experiments were conducted in which various vaccine protocols using CVI988 were tested for their protection against challenge with vv+ strain 648A by contact at day of age. Experiments 1 and 2 were to compare the efficacy of CVI988 vaccines from three different origins (CVI988-A, CVI988-B, and CVI988-C) and evaluate the effect of vaccine dose and chicken genetics. Experiment 3 was to evaluate the effect of adding CVI988 vaccine to various vaccine protocols using other MD vaccines of serotypes 2 (SB-1) and 3 (rHVT). Our results show that, regardless of the origin of the vaccine, protection against early challenge with 648A was good when vaccines were administered at a high dose (3000 plaque-forming units [PFU]). Differences among vaccines, however, were detected even when using a high dose in experiment 2 (vaccine CVI988-B conferred higher protection than did CVI988-C) but not in Experiment 1 (CVI988-B was compared to CVI988-A). The use of a fixed low dose (2000 PFU) of vaccine resulted in reduction in protection, and such reduction was more remarkable when using CV1988-A. No statistically significant differences were found when we compared the efficacy of CVI988 in two different genetic lines of broiler chickens (G1 and G2). Vaccination protocols that included CVI988 had better protection than protocols that only included MD vaccines of serotypes 2 and 3. This was true regardless of the vaccine protocol used (CVI988/rHVT+SB-1; CVI988+rHVT+SB-1/None; rHVT+SB-1/CVI988; wherein the vaccine before the slash (/) was administered in ovo at embryonation day 18 and the vaccine after the slash was administered at day of age, subcutaneously). When only vaccines of serotypes 2 and 3 were used, protection against early challenge with vv+MDV was higher when vaccines were administered in ovo (rHVT+SB-1/None) than if vaccines were administered at hatch (None/rHVT+SB-1). Monitoring vaccine DNA load in feather pulp (FP) samples at 1 wk was used to monitor vaccination, and results showed that differences in vaccine replication exist among vaccines but such differences were not necessarily related to protection (r = 0.41, P0.05). Monitoring load of challenge MDV DNA in FP at 21 days was conducted, and results correlated (r = 0.85, P0.05) with the percentage of chickens with MD lesions at the termination of the study, confirming that early diagnosis is a very powerful tool with which to evaluate protection.
- Published
- 2015
16. In Ovo Vaccination with Turkey Herpesvirus Hastens Maturation of Chicken Embryo Immune Responses in Specific-Pathogen-Free Chickens
- Author
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Aneg L. Cortes, Arun R. Pandiri, Nik M. Faiz, Taylor Barbosa, Tarsicio Villalobos, and Isabel M. Gimeno
- Subjects
animal structures ,Spleen ,Chick Embryo ,In ovo ,Antibodies, Viral ,Herpesvirus 1, Meleagrid ,Immune system ,Food Animals ,Antigen ,medicine ,Marek Disease ,Animals ,Lymphocytes ,Specific-pathogen-free ,Cell Proliferation ,General Immunology and Microbiology ,biology ,Vaccination ,Viral Vaccines ,Virology ,Specific Pathogen-Free Organisms ,medicine.anatomical_structure ,embryonic structures ,biology.protein ,Animal Science and Zoology ,Antibody ,Chickens ,Keyhole limpet hemocyanin - Abstract
Administration of Marek's disease (MD) vaccines in ovo has become a common practice for the poultry industry. Efficacy of MD vaccines is very high, even though they are administered to chicken embryos that are immunologically immature. We have recently demonstrated that in ovo vaccination with turkey herpesvirus (HVT) results in increased activation of T cells at hatch. Our previous results suggested that in ovo vaccination with HVT might have a positive impact not only on MD protection but also on the overall maturity of the developing immune system of the chicken (Gallus gallus domesticus). The objective of this study was to evaluate the effect of administration of HVT at 18 days of embryonation (ED) on the maturation of the embryo immune system. Four experiments were conducted in Specific-Pathogen-Free Avian Supplies (SPAFAS) chickens to evaluate the effect of administration of HVT at 18 ED on the splenic cell phenotypes at day of age (experiment 1) and on the ability of 1-day-old chickens to respond to various antigens compared with older birds (experiments 2 and 3). In addition, a fourth experiment was conducted to elucidate whether administration of other serotype's MD vaccines (CVI988 and SB-1) at 18 ED had the same effect as HVT on the spleen cell phenotypes at day of age. Our results demonstrated that 1-day-old chickens that had received HVT in ovo (1-day HVT) had higher percentages of CD45+, MHC-I+, CD45+MHC-I+, CD3+, MHC-II+, CD3+MHC-II+, CD4+, CD8+, and CD4+CD8+ cells in the spleen than 1-day-old sham-inoculated chickens (1-day sham). Moreover, spleens of 1-day HVT chickens had greater percentages of CD45+MHC-I+ cells and equal or greater numbers of CD4+CD8- and CD4-CD8+ cells than older unvaccinated chickens. In addition, administration of HVT at 18 ED rendered chicks at hatch more responsive to unrelated antigens such as concavalin A, phytohemagglutinin-L, and keyhole limpet hemocyanin. Administration of MD vaccines of other serotypes had an effect, although less remarkable than HVT, on the spleen cell phenotypes at hatch. Vaccines of all three serotypes resulted in an increased percentage of MHC-I+, CD45-MHC-I+, CD4-CD8+, and CD8+ cells, but only HVT resulted in a higher percentage of CD45+, CD45+MHC-I+, CD3+MHC-II+, and CD4+CD8- cells. Results of this study show that it is possible to hasten maturation of the chicken embryo immune system by administering HVT in ovo and open new avenues to optimize the procedure to improve and strengthen the immunocompetency of commercial chickens at hatch.
- Published
- 2015
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