Investigations were carried out at 6 meat producing combines on calves intended for slaughter. The animals originated from farms of different hygiene conditions. The studies aimed at establishing the extent to which the produced meat was contaminated with organisms coming from the skin cover. The total count of bacteria as well as that of coliforms in samples taken from the coat of calves were determined prior to bathing the animals, after that and after disinfection. Following slaughter the bacteria were studied at the site of separating the skin, in the abdominal muscles and in the croup. The skin of the calves for slaughter was found to be strongly contaminated with bacteria. The bathing and the disinfection with a 2 per cent chloramine solution decreased the number of microbes, however, did not fully inactivate bacteria. This contributed to the additional surface contamination of the meat obtained.

Animals↗

PubMed1981

[Methods for the control of disinfection in meat-packing plants].

Forty-eight series of experiments were carried out to establish the effect of disinfections with 2% septin, 1% tagonin, 2.5% chloramine and 2% chlorinated lime, all applied in the meat processing shops. Determined were the total count of bacteria and that of coliforms alone, employing the methods of washings and taking impression (contact) samples (Schothorst et al., 1966). It was found that these disinfection agents did not produce a complete disinfection effect. The contact method of determining the total count of bacteria proved readily applicable and suitable to investigate subjects having smooth surfaces. The combined use of the two methods to record the effect of disinfections is, however, suggested because of the diversity of the various subjects in the meat processing shops.

Bulgaria↗

PubMed1980

[Devitalization of salmonellal bacteria in boiled and smoked sausages].

Laboratory and production experiments were carried for devitalizing bouillon cultures of 7 serological types of salmonella. The laboratory experiments (73) were made in water bath, the bouillon cultures being heated following the thermic curve for the production of boiled-fumigated sausages. The production experiments (11) were carried out on sausages having a diameter of: 30-40 mm, 50-60mm and 80-100 mm. The density of bacterial cells in the bouillon and in the meat mass was 2-42.10(6)/cm3. It was proved that in vitro the critical temperature for the devitalization of salmonellas was 62 degrees C (S. enteritidis, S. agona, S. typhimurium, S. oranienburg, S. choleraesnis, S. anatum, S. lexington). During the production experiments on the sausage 'in the Macedonian fashion', the 'Kamchia' sausage (ø50-60 mm) and the 'Roussé' sausage, the salmonellas tested (S. typhimurium, S. enteritidis, S. oranienburg, S. choleraesnis ans S. dublin) showed a critical devitalization temperature of 64 degrees C. It was proved that the devitalization of salmonellas depended on the critical temperature reached and was not influenced by the type of salmonella, the diameter and the structure of the sausages. For the isolation of salmonella bacteria from thermically treated meat products a preliminary enrichment in peptone water is necessary during 18-20 hours and a second sowing on hard and in liquid selective food media.

Animals↗

PubMed1979

Epidemiological, clinical, and pathomorphological characteristics of epidemic poliomyelitis-like disease caused by enterovirus 71.

In May-September, 1975, an outbreak of epidemic disease clinically and pathomorphologically simulating nearly all known forms of poliomyelitis occurred predominantly among young infants in Bulgaria. Most cases presented benign aseptic meningitis, sometimes with a short period of general cerebra- symptoms. Paralytic forms, such as bulbar polioencephalitis, anterior poliomyelitis, isolated pareses of the facial nerve, occasional cases of encephalomyocarditis, etc., were observed in about 21% of all cases. Over one-fourth of the paralytic cases with bulbar symptoms ended fatally. In March, 1976 another sporadic fatal case of this disease was examined. No new cases occurred in 1977. Histopathological examinations in all fatal cases regularly revealed lesions in the grey matter of the medulla and spinal cord typical of acute anterior poliomyelitis and bulbar polioencephalitis, with some peculiar features of localization and depth of the involvement of the brain stem. The similarity to poliomyelitis and precariously rapid increase in the incidence led to the decision to urgently vaccinate the entire human population with Sabin's live poliovirus vaccine simultaneously in the whole country in order to produce interference with the circulating agent. This aim appeared to have been achieved partially because soon the number of new cases of the disease began to decrease; however, no sharp and complete break in the curve of the incidence occurred. By the time of mass vaccination, the results of virological examinations started before were not yet available. Later, comprehensive complete evidence was obtained that over 25 fatal and many other typical cases of the disease were associated with an enterovirus proved to be antigenically related to enterovirus 71. The diseases in Bulgaria, 1975, differ considerably in the frequency of paralytic forms and in severity from the epidemics caused by enterovirus 71 in Sweden, 1973, Australia, 1972--1973, USA, 1969--1972, and Japan, 1972--1973.

Adolescent↗

PubMed1979

[Resistance of the Aujeszky's disease virus to gamma ray irradiation].

Investigations on the resistance of Aujeszky's disease virus to gamma irradiation from a 60Co source were performed. The resistance of the virus was tested in vitro in a fluid medium of 50% Henk's balanced saline solution, 50% Eagle's medium MEM and a supplement of 10% normal calf serum as well as its resistance on artificially virus infected pig skin and greasy wool of sheep. It is established that virus inactivation in the fluid medium occurs following 1.6 Mrad gamma irradiation. The irradiated with lower than 1.6 Mrad gamma doses live virus particles form smaller than and with irregular oval shape and dentated plates as compared to the non-irradiated control virus. 1.5 Mrad gamma rays are needed to inactivate the virus on pig skin and greasy wheep's wool. The presence of lanoline in greasy sheep's wool, due to the alkaline pH (9--13) it produces, has an effect on the vitality of the virus both in the control and in the experimental samples.

Animals↗

PubMed1979

[Pregnanediol and pregnanetriol levels in the urine of rats after thymectomy].

The authors examined arterial blood pressure and excretion of pregnanetriol and pregnanediol in urine of adult male rats of Westar strain under normal conditions and after thymectomy. There was an elevation of arterial blood pressure after 45th day of thymectomy. Excretion of pregnanediol was increased on the 30th day, but that of pregnanetriol on the 60th day after removal of the gland. The increased excretion of both progesterone metabolites was connected with increased renal function, which probably played pathogenic role in postthymectomized hypertensive reaction.

Animals↗

PubMed1978

[Resistance of E. coli and bacteria of the genus Proteus to the thermal processing of perishable meat products].

Experiments were carried out in six meat combines to establish the devitalization of Escherichia coli and bacteria of the Proteus genus at the thermal treatment of perishable meat products. Seventy series of experiments were conducted with 16 types of meat products of a different structure (homogenic and heterogenic), varying composition unequal diameter of the casings (3-4 am, 5-6 am, and 7-8 am), and different type of the latter--natural, paper, and cutis-lika. Twenty-four-hour agar cultures at a density of 10(5)-10(7) bacteria per gram of meat mass were used. In a series of experiments the temperature was dermined of the finished product when it reached 68 degrees C; in another group--after smoking and at various intervals during cooking; and in a third group of experiments the temperature was fillowed up during the entire thermal process, using thermo pairs. Studied was the heat resistance of the organisms tested under laboratory conditions, using the thermal curve in the production of meat products. The samples were investigated at the 24th, and 48th hour, and on the 5th day of room temperature storage. Results showed that devitalization of these organisms set in at 63 degrees C (E. coli) and 60 degrees (Proteus). The composition and homogeneity of the meat mass and the diameter of casings were found to have no effect on the heat resistance of these organisms.

Animals↗

PubMed1977

[Agents and methods for the disinfection of the integument of animals before slaughter].

Experiments were carried out to test the disinfection effect of some agents, such as chloramine B, chloramine B+ surface active substances, vofasteril (peracetic acid), perfumaric acid, and bradofen on a dry skin or when applied immediately after washing--in buffaloes, cattle, and swine. Parallel trials were conducted under conditions of the practice as well. Escherichia coli and Staphylococcus aureus were used as model organisms. Results showed that best disinfection effect have 1.5 percent chloramine B and 0.5 per cent peracetic acid (for dry skins), and 3.0 and 0.8 per cent of the same agents when applied on wet skins (immediately after washing). The animals should be slaughtered not earlier than 10 min and not later than 30 min following disinfection. The effect of disinfection is read best on impression preparations of agar (in aluminum folio).

Abattoirs↗

PubMed1977

[Change in the quantity of coliform and Proteus bacteria during the ripening of raw, nonperishable meat products].

Studied were the changes in the amount of coliform and Proteus bacteria in the production of raw-dried and raw-smoked unperishable meat products, employing model testing procedures of experimentally contaminated meat products with Escherichia coli and Bacterium proteus, through following up the changes in the counts of coliform and Proteus bacteria in batches of regular production, and by the investigation of raw meat samples of varying moisture content. The studies were carried out at eight enterprises working under different technologic conditions. A total of twenty series of model experiments were carried out with artificially contaminated batches of products as well as twenty-one series of experiments with batches of regular production, and some 93 meat products, dried to a various extent, were sampled. Results showed that during the ripening process with unperishable meat products the reduce in the numbers of coliform bacteria is more intense than the decrease in the Proteus organisms. The process of smoking did not change the amount of these microbes. In unperishable raw meat products that meet the requirements of the Bulgarian State Standard coliforms are found in 43 per cent of the samples, and Proteus bacteria are not present.

Animals↗

PubMed1977

[Gamma ray decontamination of skins and wool contaminated with Bac. anthracis spores].

Studies were carried out to establish the sensitivity of Bacillus anthracis spores in a suspension of physiologic saline and in pelts and wool. Tested were the spores of five B. anthracis strains. The density of spore suspensions was from 1.6 X 10(6) up to 9.0 X 10(9) per cub. cm, and for the pelts and wool the spore count ranged from 7.8 X 10(8) to 5.0 X 10(10) (for the material as a whole). The irradiation was carried out on a device with a 60Co source at a temperature of 15 degrees C and rates of up to 2.75 Mrad. Data showed that the dose necessary to decontaminate infected pelts and wool is 2. 00 Mrad. The water phase of the medium has almost no effect on the sensitivity of B. anthracis spores to gamma rays.

Animals↗

PubMed1977

[Symmetry and asymmetry of the orbital opening in Bulgarians].

The authors examined 412 skulls of grown up individuals of male sex and 15 dimensions were measured for aditus orbitae. The data were prepared biostaticaly both for the most important six and for the orbital index amd orbital entrance. The dimensions showed equal size at both sides in considerable, but various for the single numbers of skulls (1/5 up to over 1/3). In the majority of the remaining skulls the absolute differences were small in favour of the one or the other side (1--2 mm). The width of the entrance was in most cases (63%) larger in the right with mean value of the differences of 1,72 mm, but the height-on the left of the average with 1,41 mm. Hamachonchia was encountered more frequiently on the right, but hypoikonchia-on the left. The dimensions, which passed through the orbital entrance transversly (three dimensions) and obliquely (one dimension) had larger values more frequently on the right.

Adult↗