[Regional ileitis - a diarrheal disease of pigs]. / Regionální ileitida - proújmové onemocnení prasat.

Morphological and histological changes were described in regional ileitis of pigs, which constitutes one of the forms of the complex of diseases referred to as intestinal adenomatosis of pigs. The most pronounced changes were concentrated on the ileum and were characterized, from the morphological point of view, by a distention of the intestinal wall and from the histological point of view, by proliferation of the epithelial cells of ileum, proliferation of the lymphatic tissue of tunica mucosae and submucosae, and hypertrophy of tunica muscularis. This disease has not been described in Czechoslovakia up to now.

[The redox potential of the large intestine in swine in relation to swine dysentery]. / Redox potenciál tlustého streva prasete ve vztahu k dyzentérii prasat.

The redox potential of (Eh) +111 +/- 25 mV was measured in the large intestine of newly born piglets. In the post-weaning period the Eh values decreased significantly to -173 +/- 27 mV and remained at this level also in the healthy sows (-214 +/- 55 mV). The Eh value recorded in dysenteric pigs was -188 +/- 5 mV, and this was not statistically significant in relation to the healthy weaned piglets. The Eh level measured in the blood agar prepared with cysteine and covered by a thick growth of the strain Treponema hyodysenteriae, which had been incubated in an anaerobic medium for five days, was -218 +/- 18 mV. The Eh of piglets after weaning was not the decisive condition for the development of dysentery. However, it can be assumed that the impossibility of eliciting dysentery in microbe-free and gnotobiotic pigs is associated with a relatively high redox potential of a microbially unpopulated or insufficiently populated intestine.

[Etiology of porcine dysentery]. / Etiologie dyzentérie prasat.

The etiological agent of swine dysentery is an anaerobic spiralshaped microorganism of the Treponema genus. Examination of a scraping from the mucous membrane of the large intestine or the examination of faeces in a native preparation by phase contrast are the fastest diagnostical methods of determining swine dysentery. Large treponemas, as predominating microflora, 6--9 micrometer long, 0.3--0.4 micrometer in diameter, spiralshaped and moving in a serpentine way are found in faeces and the mucous membrane in the case of acute swine dysentery. These large treponemas were identified in 14% of clinically healthy pigs but in very small numbers. Treponemas are sensitive to their habitat. Treponemas survive for up to five days only in faeces which are suitably reduced. This finding is important both for subduing the infection and for diagnosis.

[Isolation of Treponemas from the colon of pigs with clinical dysentery]. / Izolace treponem z tlustého streva prasat s klinickou dyzentérií.

Optimal culture conditions in artificial nutritive media were determined for a defined avirulent strain of Treponema hyodysenteriae and for four field strains of treponemas in pigs with clinical dysentery. The treponemas were isolated with the use of milliporous filters with pores of 0.3 micrometer in diameter, which were located on the surface of blood agar. No significant difference in the influence of equine, bovine or sheep blood on the growth of treponemas was determined. The commercial amount of glucose in the used media, 2.0 to 2.5 g per 1,000 ml, was quite sufficient for the growth of the treponemas and it was not necessary to increase the amount. After reaching the optimal rate of growth the oxidoreduction potential was diminished by adding cystein or cystein hydrochloride and placing the Petri dishes with the media, prior to inoculation, into an anaerobic medium filled with hydrogen. The suitable composition of the culture atmosphere created in a special anaerostat comprised 0.4 to 1.0% carbon dioxide and the rest being hydrogen. Treponemas grew on the blood agar in zones with very slight hemolysis without forming separated colonies.

[Comparison of the suitability of phase-contrast and immunofluorescence technics in the laboratory diagnosis of porcine dysentery]. / Porovnání vhodnosti metody fázového kontrastu a imunofluorescencní techniky pro laboratorní diagnostiku dyzentérie prasat.

Immunofluorescence technique, compared with the method of phase contrast, does not appear to be better for laboratory diagnostics of swine dysentery because neither of these methods can be used for distinguishing between pathogenic and nonpathogenic strains of treponemas. The number of treponemas contained in faeces should still be considered to be the main criterion in laboratory diagnostics. In clinically healthy pigs from stocks which never suffered from dysentery treponemas were found only in few cases and always in small numbers. The numbers of treponemas contained in the faeces of dysenteric pigs were several times higher. Antigenic relationship of one nonpathogenic and three pathogenic strains of Treponema hyodysenteriae was proved by the agglutination and fluoresence methods.

Genetic studies on temperature-sensitive mutants of Bacillus subtilis bacteriophage SPP 1.

A total of 30 ts mutants of Bacillus subtilis bacteriophage SPP1 were isolated and subjected to complementation test. On the basis of this test 21 mutants were classified into 4 functional groups; the classification of the remaining 9 mutants was unclear. The frequency of recombination by mutual crossing was determined in representatives of individual groups; this made it possible to place these mutants on a linear map comprising a total length of 7.62 recombination units.