ABSTRACT
A commercially available Bacillus subtilis (subspecies niger) biological indicator system may be adapted for use in monitoring the efficiency of fumigation with formaldehyde gas. Limitations to the efficient functioning of these indicators have been investigated in fumigation trials and the findings have been included in suggestions for usage.
ABSTRACT
A commercially-available flexible-film isolator kit was adapted for rearing specific pathogen free poultry and for carrying out experiments with avian pathogens. By increasing the standard air hose diameter from 32 mm to 75 mm and incorporating large metal filter canisters in place of the standard plastic filter sleeves, air flow rates were increased up to 8-fold. These changes allowed a greater number of birds to be maintained for longer periods without the previous problems of condensation of water vapour on the inside surfaces of the isolator. Fibreglass mat filters were shown to be efficient in retaining Newcastle disease virus when challenged by aerosol produced experimentally. Cross-contamination by virus infections between adjacent isolators was prevented for at least 12 weeks. The use of air-tight seals between the isolator canopy and structural components, air-tight feeder and light supports, an automatic watering system and facilities to improve portability are described. The adaptations resulted in an isolator which was efficient to use and maintain.
ABSTRACT
Reticuloendotheliosis virus (REV) was isolated in cell cultures from commercial Marek's disease (herpesvirus of turkeys) vaccine and re-isolated from the organs of vaccinated chickens. Runting and feathering abnormalities were produced when 1-day-old specific pathogen free chickens were inoculated with REV. Histopathological lesions in infected chickens were hypoplasia of the thymus, bursa and spleen, and inflammation of the proventriculus, kidneys and liver. Serological responses to REV were detected by the indirect immunoflorescence test in chickens directly inoculated with contaminated vaccine, and spread of REV infection to in-contact chickens was demonstrated by histopathological and serological investigations.
Subject(s)
Chickens , Drug Contamination , Herpesvirus 2, Gallid/immunology , Reticuloendotheliosis, Avian/microbiology , Retroviridae/isolation & purification , Viral Vaccines , Animals , Antibodies, Viral/analysis , Cells, Cultured , Fluorescent Antibody Technique , Poultry Diseases/microbiology , Poultry Diseases/pathologySubject(s)
Chickens/microbiology , Poultry Diseases/microbiology , Reticuloendotheliosis virus/isolation & purification , Retroviridae/isolation & purification , Tumor Virus Infections/veterinary , Animals , Antibodies, Viral/biosynthesis , Cells, Cultured , Poultry Diseases/immunology , Reticuloendotheliosis virus/immunology , Tumor Virus Infections/immunology , Tumor Virus Infections/microbiologyABSTRACT
Genital samples collected at autopsy from 193 beef cows representing 22 different herds in Northern Australia yielded only one isolate of infectious bovine rhinotracheitis (IBR) virus. Serological evidence showed 59 per cent of similar cows had prior infection with this virus and of 19 sero-positive cows tested, 11 (58-2 per cent) shed detectable IBR virus from the vagina after treatment with corticosteroids. Transitory lesions of the vagina and vulva developed in five of the treated cows. Twenty-six (65 per cent) of 40 sero-positive bulls shed detectable IBR virus into the prepuce after corticosteroid treatment. Except for one bull, virus was not isolated after corticosteroid treatment of sero-negative animals. IBR virus and mucosal disease (MD) virus were not isolated from nasal swabs before or after corticosteroid administration. No correlation was observed between initial circulating antiboyd titre and virus excretion after treatment. There were no significant changes in levels of serum antibody during the virus excretion period.
Subject(s)
Carrier State/veterinary , Herpesvirus 1, Bovine/isolation & purification , Sexually Transmitted Diseases/veterinary , Animals , Antibodies, Viral/analysis , Carrier State/microbiology , Cattle , Dexamethasone/pharmacology , Female , Herpesvirus 1, Bovine/immunology , Male , Penis/microbiology , Pregnancy , Pregnancy Complications, Infectious/microbiology , Pregnancy Complications, Infectious/veterinary , Sexually Transmitted Diseases/microbiology , Vagina/microbiologyABSTRACT
Natural venereal infection of heifers with IBR virus resulted in vulvovaginal lesions in 9 of 12 heifers at 3 weeks after introducttion to bulls, and virus was isolated from 5 of the 9 affected animals. The infection was not associated with any effect on conception. Experimental nasal and conjunctival infection of 18 heifers pregnant for 3, 5 or 7 months with a genital strain of IBR virus caused mild rhinitis or conjunctivitis in all inoculated animals and virus was recovered from 14 animals at 8 days after inoculation. No effects on pregnancy were recorded.
