Bovine abortion by a vaccine strain of Bacillus anthracis

ABSTRACT: This paper reports the abortion of a male Aberdeen Angus bovine by a vaccine strain of Bacillus anthracis, describing the pathological and microbiological findings and the genome sequence. Necropsy findings included multifocal areas of hemorrhage in different organs. Histologically, various organs showed hemorrhage, fibrin exudation, necrosis associated with countless bacillary bacterial clumps and severe neutrophilic inflammatory infiltrate. In the microbiological examination, numerous rough, nonhemolytic, gray and dry colonies with irregular edges were isolated from liver, lung and abomasum content samples. Gram staining revealed square-ended Gram-positive rods arranged in chains. B. anthracis identification was confirmed by detection of the molecular chromosomal marker Ba813. The genomes from the isolated B. anthracis (named SPV842_15) and from the isolated vaccinal strain (Brazilian vaccinal strain), which was recovered from a commercial vaccine used in the pregnant cow, were sequenced. Genomic comparisons displayed a high level of nucleotide identity in the comparisons between B. anthracis SPV842_15 and the B. anthracis Brazilian vaccinal strain (98,2%). Furthermore, in both strains, only the plasmid pX01 sequence was detected. Although, vaccination against anthrax is characterized by an elevated protective profile and very low residual virulence, immunization with Sterne strains can cause abortion in cattle, presumably by the plasmid pX01 toxins in rare or special situations.

Membrane Technology in the Production of Immunobiological Preparations Produced by the Branch Office of the FSBE «48 Central Scientific Research Institute» of the Ministry of Defence of Russia (Kirov)

The researchers of the Branch Office of the Federal State Budgetary Establishment «48 Central Scientific Research Institute» of the Ministry of Defence of the Russian Federation (Kirov) organized theoretical and experimental studies on the introduction of a tangential filtration method for the separation of biological mixtures into the production of immunobiological preparations. The method of microfiltration in the tangential stream replaced the process of sedimentation at the stage of concoction of intermediate vaccines, reduced considerably the process time, and allowed to obtain suspensions from cultural liquid, substandard on an indicator of concentration of microbial cells. Along with this, the microfiltration method allowed to concentrate the cultures of Yersinia pestis of a vaccinal strain EV. In comparison with the centrifugal separation, the concentration of living microbial cells of a vaccinal strain of EV Y. pestis increased by one and a half times. The filtration in a tangential stream at the ASF-020 installation from the point of view of the production of the sporous product of anthrax vaccine STI-1 (in millions of doses), is 1.8 times more effective in comparison with the centrifugal separation. The membrane method allowed to reduce the duration of technological process. These membrane processes are used nowadays during the production of plague and anthrax vaccines, anthrax immunoglobulin, diagnostic medicines and during the sterilization of liquid nutrient mediums. This type of equipment for the sterilization of nutrient mediums can be considered as an alternative to the processes of the thermal sterilization of liquids and provides their biological and technological full functionality. Experiments on the use of the ceramic-metal filters sterilizing the air given for aeration, showed the decrease in duration of preparatory operations on 20 h and increase in the general operational opportunities of the system.

Development and optimization of virus neutralization test in chicken embryonated eggs for indirect identification of avian influenza and Newcastle disease virus

Avian viral problems have been consistently reported in commercial poultry of Pakistan causing heavy economic losses to the poultry farmers. Authentic idenfication and confirmation of the causative agent is always been question mark for the selection of vaccinal strain in this regard. Current study was therefore undertaken to optimize the virus neutralization test for the serological survey of vaccinated poultry particularly for avian influenza virus’s subtypes and Newcastle disease virus. Various physiochemical factors such as concentration of antigen and antibody, Incubation temperature and incubation period for in vitro and in-vivo reaction of antigen and antibody were optimized in chicken embryonated eggs. Serum samples were obtained from vaccinated breeder birds of five commercial poultry breeder companies and subjected for VNT using different concentration of three antigen and their respective homologous antibodies under optimized conditions. AIV H9 (EID50-1×109.0/ml) and NDV (EID50-1×108.2/ml) having biological titer of 10-7 /50ul HA units were neutralize with 10-2/50ul HIU of antibody and incubated at 37°C for 30 minutes was injected subsequently into 10 day old chicken embryo followed by incubation at 37°C for 38 hours showed ≥90% neutralizing specificity. Furthermore, sera obtained from five AIV-H9, AIV-H5 and NDV exposed commercial poultry farms revealed that Big bird broiler, Big bird breeders and A&S chicks are 100% sensitive and specific whereas, Gateway chicks and Waqas poultry breeders showed 100% homology for AIV-H5 virus but do not confers similarity with prevailing AIV-H9 and NDV field strains. Therefore, high sensitivity, reproducibility and specificity VNT, it could be a tool for indirect detection of homology between vaccinal strain and wild virus antigen using known antisera. Particularly, for those organisms possess natural ability to mutate in the adverse climatic conditions. Keywords: Virus neutralization test, Avian Influenza Virus, Newcastle Disease Virus, Sensitivity, Specificity

Stability attenuation of BCG vaccine strain

As the basis for prevention of tuberculosis is the use of BCG vaccine. The experience of using the tuberculous vaccine has shown quite positive results. Mycobacterium bovis of BCG vaccine strain, which are preserved in laboratories from different countries may differ slightly in their biological properties, including virulence and immunogenicity. Objective of work is to investigate the stability attenuation of BCG vaccine strain. BCG vaccine strain (BCG-Russia) was used for investigations. The morphology, cultural and biochemical properties of mycobacteria determined by means of agreed-upon methods. We used amplifier iCycler iQ5 and a set of reagents for PCR-amplification of DNA with real-time detection for carrying out PCR. The determination of the virulence and sensitivizing properties of mycobacteria was carried out using the biological test. The pieces of the spleen and lungs were taken for histological examination. It was found that Mycobacterium bovis BCG strains formed on the nutrient medium by Mordovskyi the matted colonies of ivory color with a hilly surface and uneven edges (R-forms). In the smears from colonies, after staining by Ziehl-Neelsen, acid-resistant and non-acid resistant sticks were observed. Mycobacteria BCG strain in the medium of Shkolnykova formed microcolonies, which morphologically resembled «cord». Gene-molecular studies have established the presence of the DNA-target in the mycobacteria of the vaccinal strain. In infected Guinea pigs 3–4 weeks later, an ulcer was formed at the place of introduction of the suspension. Mycobacteria did not cause in laboratory animals the death and development of an infectious process characteristic of tuberculosis. At the autopsy of Guinea pigs characteristic macroscopic changes (tubercular nodes) were not observed. In the spleen of all animals, moderate hyperemia, red pulp hyperplasia were observed. Lymphoid follicles had signs of hyperplasia. At the intersection of laboratory animals of the second and third passages macroscopic pathoanatomical changes were not found. Conclusion: BCG strain do not cause macroscopic pathoanatomical changes in Guinea pigs during three «blind» passages, indicating the stability of his attenuation.