[Serological study of the bovine virus diarrhea-mucosal disease]. / Serologichni prouchvaniia na virusa na mukozna bolest-virusna diariia po govedata.

Employed were the virus-neutralization test (VNT), the complement-fixation tests (CFT), and the immunodiffusion test (IT) in the study of serum samples of calves on a total of 25 farms that had records of virus diarrhea-mucosal disease (VD-MD) in the course of two years. Samples were also taken from calves in the initial phase of the same disease in the course of four months. The blood of experimentally infected calves waw likewise sampled for three months. It was found that the stage of infection could successfully be studied via all three serologic methods. Thus, for example, positive VNT and CFT results coupled with negative IT results spoke of the initial stage of the disease, and vice versa--negative CFT results and positive VNT and IT results gave evidence of the advanced stage of the infection.

[Complement fixation test act in the diagnosis of mucosal disease-virus diarrhea in cattle]. / Reaktsiia za svurzvane na komplementa pri diagnostikata na mukoznata bolest-virusna diariia, pri govedata.

Experiments were made to obtain a highly active antigen for the complement-fixation test, using purification and concentration with methyl alcohol in a cell culture suspension of the causative agent of mucous disease-virus diarrhea. It was established that the CF test was sufficiently rapid and specific in the diagnosis of the disease in cattle. It proved instrumental in detecting complement-fixing antibodies in diseased and survived cattle, in calves with a latent infection and in cows with abortions.

[Chronic progressive interstitial pneumonia in sheep (adenovirus pneumonia)]. / Khronichna interstitsialna progresivna pnevmoniia po ovtsete (adenovirusna pnevmoniia).

Adenoviral infection was established in imported specialized meat strains of sheep Ile de France and Romni marsh. The disease followed a course typical of chronic interstitial progressive pneumonia with reduced tonus, loss of body weight, and high lethality. The disease was serologically proven by the discovery of specific complement binding antibodies in dynamics against the adenovirus. Titers varied from 1 : 2 to 1 : 32. The infestation was reproduced on sheep and lambs by tracheal infection with ultrafiltrate of changed lung tissue and bronchial lymph nodes. Morphologically the infection manifests itself by considerable hypeplastic processes in the lungs and less pronounced ones in the liver and kidneys. The typical changes indicated are accumulation of lymphoid cells and histocytes in the interstitial tissue, as well as adenomatous expansion of alveolar and bronchial epithelium. Considerable cell polymorphism is observed in the alveoles along with presence of gigantic cells and cell syncytia of desquamous epithelial cells, alveolar macrophages and intranuclear inclusions in some of these cells. Complications of Past. Haemolytica with developing catharalsuppurative pneumonia were observed in some cases.

[Isolation of chlamydia in keratoconjunctivitis]. / Izolirane na khlamidiia pri keratokoniunktiviti.

Two isolates, identified as Chlamydia (neorickettsia) were obtained from the lacrimal secretion of calves with an acute infection on two of a total of four investigated farms with a record of infectious keratoconjunctivitis. In about 70% of the calves that survived there were complement-fixing antibodies against the neorickettsial antigen, the titers ranging from 1:8 to 1:64. Calves that yielded the causative agent were investigated in terms of the antibody dynamics. In the remaining herds no specific antibodies were demonstrated in animals that had survived. One of the isolated strains was used to infect (via the external camera oculi) a rabbit. Acute keratoconjunctivitis followed, and the blood serum of the rabbit was found to contain complement-fixing antibodies of a titer within the 1:8-1:16 range from the 30th day on. A neorickettsial strain was also isolated from the ocular secretion of a dog with serofibrinous keratoconjunctivitis, and this was regarded as a rarely encountered finding.

Experiments on the preparations and testing of associated vaccine against foot and mouth disease and vesicular disease in swine.

Tests for associated immunization of swine against Foot and Mouth Disease (FMD) and Vesicular Disease (SVD) of swine were carried out. As a result of this investigation, it was established that the prepared and tested inactivated oil vaccine is harmless and immunogenic in sensitive animals. In investigating the course of immunity, the presence of antibody against both antigens was demonstrated in vaccinated animals. All once-vaccinated animals were defended against the virus of SVD during challenge, and 75% of them were defended against FMD. After revaccination, all immunized swine were defended against infection with both viruses. The question of the quality of the associated vaccine and the possibilities of its massive use in industrial swine rearing was discussed.

[Studies of the CFT in the diagnosis of Aujeszky's disease virus in swine]. / Prouchvaniia vurkhu RSK pri diagnostikata na virusa na bolestta na Aueski po svinete.

It was found that the complement-fixation test is a prompt and suitable method in the diagnosis of the Aujeszky's disease virus, the antigen employed being a cell culture virus. A virulent virus, a slightly virulent one, and the vaccinal mutant strain MK have shown a good complement-fixing activity and they detect specific complement-fixing antibodies in the immune serum. By means of cross CFT an antigenic relation has been established between some strains of the Herpes group and the Aujeszky's disease virus, it being predominantly unilatera. In Aujeszky's disease antisera neutralizing and complement fixing antibodies have been deomonstrated in titres up to 1:64, and in MK antisera--CF-antibodies only. In blood sera from farms with a moderate course in the manifestation of Aujeszky's disease the titre of the CF-antibodies has been 1:8.

[Experimental Q-rickettsiosis in lambs]. / Eksperimentalna ku-riketsioza po agnetata

The clinical course, serologic response, and morphologic changes were followed up in month-old lambs infected nasally and via the trachea with Rickettsia burneti at the rate of 10,000 ID50/cm3. Rickettsiae were found in the parenchymal organs, the blood clot, the nasal cavity, the trachea, and the feces of the animals killed on the 7th and 21st day of infection. Complement-fixing antibodies were established in the infected lambs with the use of the complement-fixation test from the 5-6th up to the 160th day (period of testing), the highest value of the titer (1:160) being observed on the 32nd day. Demonstrated were changes in the vessels, and degeneration was found in the liver, kidneys, and other viscera along with proliferative changes in the spleen. Guinea pigs and albino mice were successfully made use of to isolate Rickettsia burneti from the infected parenchymal organs, feces, and others of affected lambs.

[Studies of the complement fixation reaction in infectious rhinotracheitis in cattle]. / Prouchvaniia vurkhu reaktsiiata za svurzvane na komplementa pri zarazniia rinotrakheit po govedata

The complement-fixation reaction was used in the diagnosis of infectious bovine rhinotracheitis establishing its specificity and effectiveness. Highest titers of the antigens tested (up to 1:16) showed antigens that were concentrated with the use of poly ethylene glycol. In performing the test both the antigen and the complement were used in a dose that contained two units of each of them. Thus the use of the complement-fixation test proved instrumental in determining specific complement-fixing antibodies in animals that had recovered from the disease, or animals that had latent infection or had been vaccinated. The titers established usually ranged from 1:2 to 1:8, and in single cases they reached 1:128. On the infected farms some animals presented both complement-fixing and neutralizing antibodies. In Herds with positive reagents was also isolated the virus of bovine rhinotracheitis.

[Isolation and identification of a virus causing abortions and stillbirths in swine (Preliminary report)]. / Izolirane i identifitsirane na virus, prichiniavashch aborti i m'rtvi razhdaniia pri svinete (Predvaritelno s'obshchenie)

A virus of the RNA type, having no lipid envelope, acid-fast and stable to heat, was isolated from an aborted fetus and from the kidney of a piglet of a lower viability at birth. It was readily cultured, multiplying quickly in primary cell cultures of pig kidney and in the SPEV cell line, producing a characteristic cytopathic effect. It gave no hemagglutination with human, chicken, and swine erythrocytes. Serologically, it was identified as a swine enterovirus of serotype I, identical with the viruses described as the etiologic agents of SMEDI.

[Complement fixation reaction (CFR) in adenovirus infections of calves]. / Reaktsiiata za svurzvane na komplementa (RSK) pri adenovirusnite infektsii po teletata

Studied was the complement-fixation reaction in the diagnosis of the adenovirus infections in calves. It was found that the test is specific and sensitive. A virus suspension of tissue cultures was used as an antigen, its titer varying from 1:8 up to 1:16. Specific complement-fixing antibodies were detected mainly in survivals at serum dilution of up to 1:64. Specific antibodies were established in undiluted sera too taken from animals of infected herds. In some of the tested sera there were both complement-fixing and precipitating antibodies. In calves treated with a live vaccine against adenoviruses the dynamics of the complement-fixing antibodies was followed up.

[Morphologic and virologic studies of the fetus and placenta in neorickettsial abortion in cattle]. / Morfologichni i virusologichni prouchvaniia na fetusi i platsenti pri neoriketsiozni aborti po govedata

A total of 19 fetuses and 10 placentas were studied. Four fetuses and one placenta harboured neorickettsiae, and the remaining fetuses and placentae originated from cows in the serum of which there were complement-fixing antibodies. These ranged within 1:8-1:64. The gross lesions of the fetuses consisted in the presence of edema with enlargement of the liver. The changes were more characteristic histologically. The liver, kidney, heart, adrenals, and occasionally the lung and spleen had foci of histiocytes, lymphoid and plasmatic cells, and fibroblasts, sometimes with the presence of sporadic leukcoytes. The presence of such cell elements agglomerated in foci fairly often built up formations of granulomatous character. The focal processes prevailed, however, there were diffuse reactions too. Histologically, there were in the placenta diffuse edemas, hyperemia, single hemorrhages, and multiple necrotic foci. A correlation was established between the serologic, virologic, and morphologic changes which made more feasible the diagnosis in such abortions.