[Specific prophylaxis of gangrenous mastitis in sheep]. / Spetsifichna profilaktika na gangrenozniia mastit po ovtsete.

Staphylococci were isolated from the udder of dead sheep and sheep that were emergency-slaughtered because of a gangrenous mastitis infection. The organisms proved to be hemolytic and mannite- and catalase-positive, and were referred to various phage types, being most frequently lysed by phages 78 and 42E. Toxin production depended on the quality of the medium used, the amount of atmospheric carbon dioxide, the period of incubation, and the individual strain qualities. Strains of high hemolysin production were used to prepare a vaccine which was applied to sheep both experimentally and in the conditions of the practice at the time of active lactation. Following treatment of the vaccinated animals parallel to a number of controls with one and the same challenging agent morbidity with the first group ran as high as 25 per cent with no death cases, while with the second group it was 100 per cent, and mortality with the latter was 50 per cent. Immunity with the use of the vaccine lasted but four months, therefore, revaccination was needed by the end of this period.

[Microorganisms of the fam. Micrococcaceae in the production and storage of prepackaged veal]. / Mikroorganizmi ot sem. Micrococcaceae pri proizvodstvoto i sukhranenieto na razfasovano teleshko meso.

Studies were carried out on the numbers and composition of organisms belonging to family Micrococcaceae in the production and storing of calf meat on a dressing combine supplied with modern equipment. Investigated were a total of 60 samples taken from small cuts of veal of the various carcass parts. The samples were packed either under vacuum or without such, and were studied immediately after cutting in small parts or after storing for 48 and 72 hours at 4 to 6 degrees C. It was found that the amount of Micrococcaceae organisms on the surface of cut meat packed out or in vacuum was within the range of 10(3) up to 10(4)/g, and it was shown to be in close relation to the microbial contamination of the initial raw material. There was no rise of the numbers of micrococci and staphylococci of veal that was cut and packed out of vacuum and kept for 48 hours at 4 to 6 degrees C. At refrigerator storing of veal that was packed under vacuum there was no increase in the microbial numbers at the 72nd hour. This pointed to the advantage of using the introduced technology of packing the meat under vacuum. Micrococcus luteus (56.7%), Micrococcus varians (41.8%), and Staphylococcus saprophyticus (1.5%) were isolated from cuts of veal packed both in and out of vacuum. No pathogenic staphylococci were found.

[Production of enterotoxins A, B and C in staphylococcal strains isolated from animal food products and other sources]. / Prouchvaniia vurkhu produktsiiata na enterotoksini A, B i C v shtamove stafilokoki, izolirani ot khranitelni zhivotinski produkti i drugi iztochnitsi.

Studies were carried out on the production of enterotoxins A, B, and C by a total of 654 strains of Staphylococcus aureus. Of these, 326 were isolated from food products of animal origin (and had no connection with intoxications); 190 were isolated from personnel working in the food industry; and 138 were isolated from milk animals, containers, and equipment at productional enterprises. Thirty strains of S. epidermidis, isolated from food products and workers were likewise tested for the production of the same enterotoxins. The enterotoxins were obtained by the modified method of Hallander, and their demonstration was performed by a variant technique of the double gel diffusion test after Ouchterlony. It was found that the Staphylococcus aureus strains isolated from food products produced enterotoxins in 12.3 per cent of the cases; was found in 6.1% of the strains, C--in 3.1%, and B--in 2.5%. Types A and C were found simultaneously in 0.6% of the strains. Enterotoxins were found in 16.6% of the strains isolated from workers and in 1.7% of those isolated from the udder of cows. The incidence of toxin production and the relative share of the three types of enterotoxins depended on the origin of staphylococci and their capacity to produce them in amounts that could be demonstrated by the methods employed. Under optimal conditions the amounts varied: for strains that produced type A they ranged from 1 to 20 micrograms/cm3; for those that produced type B they were from 1 up to 100 micrograms/cm3; and for those that produced type C they were from 1 to 40 micrograms/cm3. No production of enterotoxins A, B, and C was established with S. epidermidis strains.

[Modified rapid method for the quantitative determination of S. aureus in food products and washings]. / Modifitsiran burz metod za kolichestveno opredeliane na S. aureus v khranitelni produkti i smivki.

Suggested is the use of a modified rapid method for the quantitative determination of Staphylococcus aureus in food products and washings, worked out on the basis of the method described by Lachica [8]. In the modified method a yolk-salt agar is substituted for Baird-Parker's medium. Provided is inactivation of the thermolable nucleases at 65 degrees C for one hour and additional incubation at 37 degrees C for 2 hours following the overlaying of the agar with toluidineblue DN-ase agar. Comparative investigations on the quantitative determination of Staphylococcus aureus in experimentally and naturally contaminated food samples and washings showed that there were no essential differences between the microbial counts as established by the two methods. The modified method made it possible to shorten the investigation by 2 hours. It proved specific and readily applicable for rapid laboratory diagnostics.

[Enterotoxic staphylococci in the milk of cows and sheep with mastitis]. / Prouchvaniia vurkhu enterotoksichni stafilokoki v mastitno krave i ovche mliako.

Studied were the occurrence and the biochemical and phage characteristic of enterotoxic staphylococci in cow and sheep milk from animals with mastitis. Milk samples taken from 150 cows and 120 ewes were investigated for the presence of Staphylococcus aureus. This organism was found in 88 per cent of the cow milk samples and in 89.2 per cent of the sheep milk ones. The count of bacteria was within the 10(1) to 10(5)/cm3 range. A total of 239 strains of Staphylococcus aureus were isolated from both kinds of milk. They were tested for enterotoxigenicity after Ouchterlony. It was shown that 28.8 per cent of those isolated from mastitis cow milk and 7.5 per cent of those isolated from mastitis ewe milk produced an enterotoxin. Those from the cow milk samples produced enterotoxin A in 65.8 per cent of the cases, enterotoxin B in 13.1 per cent, and enterotoxin C in 5.3 per cent. Simultaneous production of A and D toxin was found in 15.8 per cent of the strains. Those isolated from the ewe milk samples produced enterotoxin C in 75 per cent of the cases, and enterotoxins A and C in 25 per cent. The enterotoxigenic Staphylococcus strains were distinguished by high biochemical and enzyme activity, however, none of the methods tested proved specific for enterotoxic Staphylococci only. The enterotoxic staphylococci of cow milk were typed by II and IV phages and by a mixed group of phages (II/M, III/M, IV/M, II/IV). Most spread were the 116 and 116/118 phage types.(ABSTRACT TRUNCATED AT 250 WORDS)

[Demonstration of envelope-containing viruses by the agglutination of antibody-coated Staphylococcus aureus]. / Dokazvane na virusi, sudurzhashti obvivka, chrez aglutinatsiia na natovareni s antitela Staphylococcus aureus.

A rapid agglutination method was worked out for the demonstration of the Newcastle disease virus (NDV) and the bovine leukosis virus (BLV) with the use of specific antibody-charged Staphylococcus aureus cells. It consists in the production of formalin-treated St. aureus cells, their sensibilization with specific antibodies, and their agglutination with the respective viral antigens. The latter were obtained from cell lines infected with NDV, resp., BLV as well as with purified NDV. It is concluded on the basis of the results obtained that the agglutination test suggested is rapid, specific, and sensitive and can be employed as an adjunct means in various immunochemical investigations and in the practice for the demonstration of the virus in infectious material.

[Microbiological studies of pheasant meat]. / Mikrobiologichni prouchvaniia na meso ot fazani.

Investigations were carried out to establish the total count of aerobic mesophiles and that of coliform bacteria, enterococci, staphylococci, micrococci, and sulfite-reducing clostridia in the meat and internal organs of pheasants that were eviscerated up to 30 and 60 minutes following their killing. It was demonstrated that the total counts of all bacteria mentioned rose 2.8, 2.4, and 2.2 times when studying the meat and viscera of pheasants 60 min after killing as against those found 30 min after killing. Determined was the species composition of the isolated microflora. No Salmonella bacteria, pathogenic staphylococci, and sulfite-reducing clostridia were isolated.

[Cold resistance of S. aureus and staphylococcal enterotoxins A and C2 in ice cream]. / Studoustoichivost na S. aureus i stafilokokovi enterotoksini A i C2 v sladoled.

Studied was the cold resistance of enterotoxinogenic strains of Staphylococcus aureus and of A and C2 staphylococcus enterotoxins in milk and cream icecream kept under refrigerator conditions for 7 months at -18 degrees C. The S. aureus strains were shown to have high resistance in icecream. The survival rate of the organisms depended both on the specific peculiarities of the individual strains and on the composition of the icecream mixture. Staphylococci were found to survive longer in milk icecream. A and C2 enterotoxin retained fully their activity in the two types of icecream over the entire period of storing. The data obtained is important for the elucidation of the epidemiology of alimentary staphylococcus intoxications.

[Presence of enterotoxin D in Staphylococcus aureus strains isolated from food products]. / Nalichie na enterotoksin D v shtamove Staphylococcus aureus, izolirani ot khranitelni produkti.

Studied was the capacity of 243 S. aureus strains to produce enterotoxin D after they were isolated from food products. It was found that 3.3 per cent of the strains produced enterotoxin D, the simultaneous production of A and D toxins being established in 2.5 per cent of the cases. The detection of an enterotoxin of such antigenic type pointed to its demonstration in cases of food intoxication as well as when hygiene control of food products was carried out.

[Yersinia enterocolitica survival in Bulgarian yogurt and Vita yogurt (experimental studies)]. / Prezhiviaemost na Yersinia enterocolitica v bulgarsko kiselo mliako i kiselo mliako "Vita" (eksperimentalni prouchvaniia).

Laboratory studies were carried out on the development and survival of Y. enterocolitica in Bulgarian sour milk and sour milk 'Vita'. The raw cow milk was contaminated with various amounts of Y. enterocolitica cells. Results showed that the development and survival of the organism in the sour milk was dependent on its count in the raw milk and the running of the process of lactic acid fermentation. Under refrigerator conditions (Bulgarian sour milk contaminated at the rate of 10(4) microbial cells per cm3) Y. enterocolitica retained its viability up to the 24 th hour. When contamination reached 10(5) and 10(5) cells per cm3 the viability of the organism lasted up to 72 hours. Sour milk 'Vita' with a starter of strain of Lb. bulgaricus, producing D (-) lactic acid, possessed stronger inhibitory action on Y. enterocolitica compared with milk with a starter of strain of Lb. bulgaricus, producing L (+) actic acid.

[Comparative studies on the biochemical properties, phage relationships and antigenic structure of S. aureus strains isolated from sheep]. / Sravnitelni prouchvaniia vurkhu biokhimichnite svoistva, fagovite otnasianiia i antigennata struktura na shtamove S. aureus, izolirani ot ovtse.

Defined were the biochemical, phage, and antigenic properties of a total of 104 strains of S. aureus of the udder. It was found that by their biochemical behaviour 85 of the strains corresponded to var. ovis. Phage typing showed that the strains were lyzed in a highest percent by phages of groups IV and M. Dominating were the 42D/78/107/119 and 78 phages. Studies revealed that the strains were antigenically homogenic. Antigens h2 and k1k2 were characteristic of S. aureus var. ovis.

[Enterococcal studies of uncut raw dried meat products]. / Prouchvaniia vurkhu enterokokite v surovo susheni mesni produkti ot nerazdroben vid.

Studies were carried out on a total of 75 samples of raw-dried meat products of a compact type--dried beef, Gabrovska Keiser dried meat, pig salted neck, rolled meat Trapezitsa, V. Turnovo delicacy, and Elena fillet, to establish the amount of Staphylococcus bacteria. It was found that the enterococcus titer of this type of meat products varied from 10(-1) to 10(-4), depending on the product. Most strongly contaminated with enterococci proved the pig salted neck. The higher amounts of enterococci in the studied products as well as their higher resistance to the action of unfavourable factors (ph, NaCl, water content) showed their advantage over the coliform bacteria as sanitary-index organisms in raw-dried meat products of a compact type. Various ratios of all species of enterococci were established in these products. Str. faecius was most often found (32.44 per cent), followed by Str. faecalis (26.22 per cent), Str. faecalis var. liquefaciens (16.00 per cent), and Str. durans (12.00 per cent). Str. faecalis var. zymogenes (8.00 per cent) and Str. bovis (5.33 per cent) were isolated less frequently from some of the products only.

[DNA nucleotide composition of Gram-positive cocci isolated from food products of animal origin]. / Nukleotiden sustav na DNK ot grampolozhitelni koki, izolirani ot khranitelni zhivotinski produkti.

Studied was the nucleotide composition of 34 strains of gram-positive cocci isolated from slaughtered birds, sheep milk, and milk from mastitis-affected cows and ewes. The differentiation of the strains was carried out in conformity with the instructions of Bergey's Manual of Determinative Bacteriology (1974) on the basis of the following indices: morphology of colonies, morphology and staining of the cells after Gram, catalase, oxydase, respiration type, fermentation of manite, production of plas mocoagulase, thermonuclease, and phosphatase and response to novobiocin. The amount of guanine, adenine, cytosine, and thymine in the investigated strains was determined after the method of Spirin and Belozerskii. On this basis the guanine-cytosine percent was calculated. Results showed that the use of the guanine-cytosine percent made it possible to more accurately differentiate the genus with gram-positive cocci. In 88.24 per cent of the investigated strains there was coincidence between the guanine-cytosine percent and their biochemical characteristics. Two of the strains (guanine-cytosine percent 49.95 and 47.48) were shown to belong to the group of planococci. No typical micrococci (with a guanine-cytosine percent of more than 60.00) were established.

[Characteristics of th staphylococci isolated from slaughtered sheep]. / Kharakteristika na stafilokoki, izolirani ot zaklani ovtse.

A study was carried out on the type composition and the biochemical characteristics of 449 staphylococcic strains, eliminated from the corpses of slaughtered small ruminants (sheep and lambs) in 3 meat-producing enterprises. It was established that out of the 449 staphylococcic differentiated strains--50 (11.14%) were Staph. Aureus, 247 (55.01%)--Staph. Saprophyticus, and 152 (33.85%)--Staph. Epidermidis. The fermentation of mannite in anaerobic conditions is characteristic of coagulative positive staphylococci, eliminated from small slaughtered ruminants. Ninety five per cent of the Staph. Aureus strains and 51.97% of the Staph. Epidermidis strains, made phosphatase active, and due to this test cannot be accepted as a basic one in differentiating Staph. Aureus. The typified, byt the aid of the bovine set, Staph. Aureus strains belong to the 2d, 3d and 4th indefinite "M" phago-group or are mixed. The most frequent phagotypes are 116, 118 and 53/77.

[Differentiation of bacilli isolated from raw and pasteurized milk]. / Diferentsirane na batsili, izolirani ot surovo i past'orizirano mliako.

A study was carried out on the species composition, as well as on the biochemical characteristics of 190 strains of aerobic spore-forming microorganisms of the type Bacillus, isolated from fresh and pasteurized milk. The differentiation of bacilli was made following Petrova's diagram [4]. It was established that the bacillary strains studied referred to I morphological group--Bac. licheniformis 55.9%, Bac. subtilis 24.8%, Bac. puminis 14.7% and bac. cereus 4.6%. The results of the experiments that were carried out with regard to the most characteristic morphological, biochemical and cultural properties of bacilli of group I, coincided with the data in Petrova's diagram. The bacillary strains that were isolated showed high biochemical activity with regard to proteins and carbohydrates, which is of paramount importance for the hygiene and quality of fresh and pasteurized milk.

[Psychrotrophic microorganisms in raw and pasteurized milk]. / Prouchvaniia vurkhu psikhrotrofnite mikroorganizmi v surovo i past'orizirano mliako.

The studied were carried out in 360 samples of unboiled milk and 1080 samples of pasteurized milk taken from three processing and distributing dairies having a different capacity and equipment. It was proved that the content of psychrotrophic microorganisms in unboiled milk from the three dairies varied from 120000 up to 200000 in 1 cm3 and was in close connection with the seasons of the year. The conditions applied for pasteurization in the three dairies killed (with the exception of those forming spores) nearly all psychrotrophic bacteria. The secondary seeding of the pasteurized milk by means of psychotrophics was carried out after the pasteurization along the whole technological route till its packing. The pasteurized milk packed in bottles showed a contamination with psychrotrophic microorganisms 4-6 times higher than that of milk packed in plastic bags. In the unboiled and in the pasteurized milk we found the psychrotrophic microorganisms of the species: Pseudomonas--respectively 64% and 53.8%, Micrococcus--8.2% and 30.7%, Enterobacter--9.8% and 2.6%, Bacillus--6.6% and 2.6%, Flavobacter--1.6% and 1.3% and Torula--2.6%. A comparatively high percentage (37.7%) of the isolated strains the psychrotrophic bacteria were lipolytic in the unboiled milk, 24.6%--proteolytic and 9.8% were simultaneously proteolytic and lipolytic. In the pasteurized milk 11.5% of the strains were lipolytic and 5.13% were proteolytic.

[Psychrotrophic and coliform microflora of the udder in cows]. / Psikhrotrofna i koliformna mikroflora po vimeto na kravi.

A study of the psychrotrophic and coliform microflora over the udders of cows was carried out. It was proved that the way and means of cleaning them exercise a great influence on the composition of the psychrotrophic and coliform microflora. The psychrotrophic flora over the udders consisted of 46.9% of specimens of p. Micrococcus, 8.7%-p. Streptococcus, 8.2% Staphylococcus, 7.4%-Corynebacterium, 2.8%-Saccharomyces, 10%-coliform bacteria, 12.5%-psychrophils, mainly of p. Pseudomonas and p. Flavobacterium. The coliform microflora over the udders consisted of 55.4% of p. Escherichia, 20.8%-p. Citrobacter, 16.8%-Klebsiella and 6.9%-p. Enterobacter.

[Staphylococci in uncut raw dried meat products]. / Prouchvaniia vurkhu stafilokokite v surovosushenite mesni produkti ot nerazdroben vid.

Studied were a total of 75 samples of raw-dried meat products in a compact form (dried beef, Gabrovska Keiser dried meat, pig salted neck, Trapezitsa rolled meat, Veliko Turnovo delicacy, and Elena fillet) produced at 11 Meat Works for the presence of staphylococci. It was found that the Staphylococcus titre in such raw-dried meat products was within the range of 10(-3) to 10(-7). Veliko Turnovo, Gabrovska, and Trapezitsa products were shown to be most contaminated. Coagulase-positive staphylococci were demonstrated in as much as 0.1 g of them--in the case of Elena fillet all samples were positive, with dried beef--10 samples, with Trapezitsa--7 samples, with Gabrovska--4 samples, and with pig salted neck 2 samples. The isolated strains of coagulase-positive staphylococci (48) were chiefly of bovine origin, and were typed by means of a mixed phage set comprising phages of groups II, III, and IV. The most commonly established phage types were 53/6/42D77 and 42D/102/107/117/119/77/42E. The compact raw-dried meat products were shown to contain all species of staphylococci. Staphylococcus epidermidis was most often isolated (with the exception of Elena fillet).

[Finding of the staphyloccoi and streptococci of mastitis on the udder after various ways and means of cleaning]. / Vurkhu nakhodkata na mastitni stafilokoki i streptokoki po vimeto pri razlichni nachini i sredstva za pochistvaneto mu.

The presence of mastitis staphylococci and streptococci on the udder's surface of 400 cows was studied following application of various ways and means of cleaning. The presence of agents causing mastitis was determined before and after cleaning the udder. On uncleaned udder surfaces presence of mastitis staphylococci was observed in 52.5% and of mastitis streptococci--39.5% of udders studied. After washing with water mastitis staphylococci--on 12-20% of the udders. Following udder cleaning with solutions of antigerm 50 (0.04%) or yozan CCT (4%), mastitis staphylococci were found on 4% and 6% of the udders, respectively, while mastitis staphylococci--on 2% and 6%, respectively. Udder surface staphylococci belong in 2.2% to II phagous group, in 46.6%--to the III group, and in 37.7% -- to mixed groups. The most frequently encountered phagous types were 6 and 42D.

[Presence of E. coli bacteria in raw and pasteurized cow's milk]. / Nalichie na E. coli bakterii v surovo i past'orizirano krave mliako.

Investigated for the presence of E. coli-bacteria belonging to the O-groups of dispeptic strains, are 85 samples of raw and 212 pasteurized milk, taken from subsequent departments of the milk-producing industry. Dispeptic E. coli are detected in 11.76 per cent of the samples of raw milk studied, and in 5.18 per cent in those of the pasteurized milk. No coli forms are established in samples, taken directly from the pasteurizing equipment. The secondary infection with E. coli results from the use of vessels and equipment in the course of the technological process. E. coli-bacteria, belonging to the O-groups of dispeptic strains, are demonstrated in samples both with the aid of a coli-titre, in conformity with standard requirements, and in samples that are not standard, according to this indice. The 21 strains of E. coli-bacteria isolated are referred to the following O-groups: 06, 025, 026, 055, 078, 086, 0111, 0119, 0124, 0125 and 0127. Some of the strains isolated manifest an atypical behaviour to lactose and sucrose in comparison with the properties, indicated in the scheme by Kauffmann.