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Biomedical subjects

M A Muneer

Publications and source records attributed to M A Muneer.

8 recordsLinked to original sources

Identification of the antigenic components of the virulent Mycoplasma gallisepticum (R) in chickens: their role in differentiation from the vaccine strain (F).

The antibody response to different proteins of Mycoplasma gallisepticum (MG) was studied in chickens experimentally infected with virulent MG R strain. The chickens were challenged at 8 weeks of age by the intranasal route. Each cockerel received 1.3 X 10(6) colony-forming units (CFU). MG strains (R and F) were banded by Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE). The banding pattern was distinctively different between the two strains in the range of 92.5 to 200 kilodaltons (kD). Chicken sera collected at different times following challenge were analyzed by Western blot to determine the patterns of antibodies raised to specific MG proteins (R versus F strains). Early in infection (2 weeks postchallenge), antibodies to 60-kD and 75-kD polypeptides of MG R strain were produced. Subsequently (greater than or equal to 4 weeks postchallenge), antibodies recognized a larger number of MG antigens in both strains. The immunoblot patterns remained the same in the period 8-11 weeks postinfection in each of the two strains; however, the patterns were different when the two strains were compared. The early response recognized the 75-kD protein in the R strain while it recognized the 80-kD protein in the F strain. The late response recognized the 130-kD protein and the protein slightly heavier than 200 kD in the R strain. These two bands did not appear in the immunoblot performed against the F strain of MG. Electroeluted protein of MG R strain, namely adhesin (75 kD), showed a hemagglutination activity (HA) on chicken red blood cells. With the appearance of antibodies specific to the 60-kD and 75-kD polypeptides, there was a significant rise in hemagglutination-inhibition geometric mean titer of chicken sera.

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Detection of parvoviruses in wolf feces by electron microscopy.

One hundred fifteen wolf (Canis lupus) feces were collected between 1980 and 1984 from northeastern Minnesota and were examined for canine parvovirus by negative contrast electron microscopy. Of these, seven (6%) samples revealed the presence of parvovirus. Some of these viruses were able to grow in cell cultures forming intranuclear inclusion bodies and giant cells.

Animals↗

Efficacy of infectious bronchitis virus vaccines against heterologous challenge.

Twenty-four-week-old white Leghorn layers were inoculated subcutaneously with a killed Newcastle disease-infectious bronchitis (Massachusetts type) virus (MIBV) vaccine. Twenty-eight weeks after vaccination, the birds were challenged intraocularly with the Arkansas strain of infectious bronchitis virus (AIBV) to determine the effects of heterologous virus exposure on egg production, egg quality and serum antibody response of the birds. The challenged hens laid significantly (P less than 0.005) fewer eggs than the unchallenged layers. Eggs laid by the unchallenged groups weighed significantly more (P less than 0.005) than those laid by the challenged groups. Further, the internal quality (Haugh units) and shell quality of eggs laid by the AIBV-challenged hens was significantly (P less than 0.005) inferior to those from the unchallenged hens. In addition, the AIBV-challenged hens laid more soft-shell, misshapen and small eggs than the unchallenged hens. The Arkansas serum haemagglutination inhibition (AIBV-HI) titres of AIBV challenged birds increased up to four weeks after challenge. The corresponding MIBV haemagglutination-inhibition (MIBV-HI) titres decreased during the same period. The study indicates that killed MIBV vaccine offered no protection to birds exposed to heterologous AIBV.

Animals↗

Antibodies to avian infectious bronchitis virus in Pakistani chickens.

Using the hemagglutination inhibition test, sera from 20 diseased and 3 apparently healthy chicken flocks in Pakistan were examined for antibodies to four types of avian infectious bronchitis virus (AIBV). These flocks were not vaccinated against AIBV. Of the 900 serum samples from diseased flocks, 78 (8.7%) had antibodies to the Massachusetts (M41) type, 23 (2.6%) to the Arkansas type and 20 (2.2%) to the Connecticut type of AIBV. None had antibodies to the JMK type. None of the sera (n = 100) from apparently healthy layers was positive to any of the four AIBV types tested. Some of the birds with antibody titers exhibited no signs of illness except that they laid pale colored eggs or had a history of poor hatchability. These results indicate that at least three AIBV types are circulating in chicken flocks in Pakistan.

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Effects of avian infectious bronchitis virus (Arkansas strain) on vaccinated laying chickens.

Twenty-four-week-old white leghorn layers were inoculated subcutaneously with a killed Newcastle-infectious bronchitis (Massachusetts type) virus (MIBV) vaccine. The birds were challenged 194 days later intraocularly with Arkansas strain of infectious bronchitis virus (AIBV). The challenged hens laid significantly (P less than 0.005) fewer eggs than the unchallenged layers, and the eggs laid by the challenged groups weighed significantly less (P less than 0.001) than those laid by the unchallenged groups. Further, the internal quality (Haugh units) and shell quality of eggs laid by the challenged hens were significantly (P less than 0.005) inferior to the quality of eggs from unchallenged hens, and the challenged hens laid more soft-shelled, misshapen, and small-sized eggs than the unchallenged hens. The Arkansas serum hemagglutination-inhibition (AIBV-HI) titers of challenged birds increased continuously through 29 days post-challenge. The MIBV hemagglutination-inhibition (MIBV-HI) titers of killed-MIBV-vaccinated birds decreased during the same period. The study indicates that killed MIBV vaccine offered no protection to birds exposed to AIBV. The same vaccine was quite effective against a homologous (MIBV) virus challenge.

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A dot-immunobinding assay for infectious bronchitis virus.

Common Whatman filter paper grade 1 and nitrocellulose membrane were compared for their sensitivity in a dot-immunobinding assay for detection of serum antibody titers to Arkansas avian infectious bronchitis virus (AIBV). For a blue to purple color detection, serum antibodies were bound to AIBV antigen adsorbed on the filter-paper discs or nitrocellulose membrane. Rabbit anti-chicken IgG horseradish-peroxidase (HRP) conjugate and hydrogen peroxide with 4-chloro-1-naphthol (HRP-color development reagent) were applied. The study indicates that very small amounts of antigen/antisera are needed for the dot-immunobinding assay. The test is sensitive, economical, and easy to run and can be completed within 6-8 hours.

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Effects of infectious bronchitis virus (Arkansas strain) on laying chickens.

Seventy-seven-week-old white leghorn layers were inoculated intraocularly with the Arkansas strain of infectious bronchitis virus (AIBV) to study the effects of the virus on egg production and on antibody response of the birds. Infected hens laid fewer eggs than the controls, and those eggs weighed less than eggs laid by controls. Further, the shell quality and internal quality of eggs laid by infected birds were inferior. The serum hemagglutination-inhibition (HI) titers of infected birds increased continuously through 4 weeks postinfection; serum HI titers of the controls were negligible.

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