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Biomedical subjects

J Bittner

Publications and source records attributed to J Bittner.

At least 55 records · Page 3Linked to original sources

[Simple method for production of conditions of general anaerobiosis].

The description is given of a modified method starting from the alkaline pyrogalol technique, described by Béerens and Tahon-Castel, for obtaining anaerobiosis in Petri dishes. The modification consists in: sealing the dishes with paraffin, adding of talcum in the reducing mixture instead of silica, and use of the ready prepared mixture ovar a period of at most 6 months. The method was tested against the reference method using suspensions of C. Oedematiens (species demanding strictly anaerobiosis conditions), C. histolyticum (somewhat less exigent) and C. perfringens spores (mean esigence), seeding on the surface of dishes with Willis-Hobbs medium. The comparative experiment, counting 30,941 colonies on 408 Petri dishes proved the value of the method proposed. The procedure was just as efficient in surface cultures of nonsporulate anaerobic germs.

Anaerobiosis↗

Contributions to the taxonomy and biology of Clostridium difficile.

Clostridium difficile was incriminated by Hughes and Jarvis (1987) as a cause of intestinal infections in USA in the 1980-1984 period in 45 p. 100 of cases, whereas Salmonellae only in 12 p. 100. Four strains of this organism are studied in this paper in comparison with ten strains of C. bifermentans and six of C. sordellii, because the three species share a common antigen and have other common characteristics, as well. However, spores of C. difficile swell the bacteria and those of other bacteria (C. bifermentans and C. sordellii) do not; C. difficile does not produce indole, whereas the other species produce it. We confirmed the selective capacity of the medium of George et al. (1979) using the "alcohol shock" and as selective agents cycloserine D and cefoxitin. C. difficile proved to be most susceptible to metronidazole and rifampin. Whereas the former antibiotic was considered as a cause of post-antibiotic intestinal infections by different authors, the second was not, to our knowledge. The strain 10463 has a considerable toxicity (1000 DLM/ml for the white mouse, and pathogenicity--2000--5000 DCL for the white mouse, as compared to 25 DCL of the other three strains). Using this toxin an antitoxic serum was obtained in horse, with a capacity of neutralizing the action of the toxin up to a dilution of 1 p. 1000.

Aerobiosis↗

Detection of Bacteroides fragilis group by immunofluorescence.

The following strains: B. fragilis subspecies thetaiotaomicron (A); B. fragilis subspecies fragilis strain E-1, E-2, M, St., Se., Ni., 8, 16; B. fragilis subspecies distasonis 145 (D) were serologically studied by immunofluorescence as compared to agglutination. Anti-B. fragilis sera titration by immunofluorescence (IF) reaction, as compared to agglutination reaction in tube, was more sensitive (2-16 times higher titers), specific and reproducible. Among the organisms from B. fragilis group, species, subspecies and even train specificity was noticed. Also, the possibility for rapid identification of anaerobic organisms, belonging to B. fragilis group, in pathologic products obtained from experimentally infected animals (mice and rats), by IF reaction, in comparison with classic methods (anaerobic cultures and biochemical determinations) was studied. Of 87 studied animals, 61 proved positive by cultures and 59 by IF; 56 animals were shown positive and 23 animals proved negative by both methods (intermethods concordance in 79 cases). Statistical analysis of IF results provided the following: method sensitivity (detection capacity of real-positive cases)-91.80%; method specificity (detection capacity of real-negative cases)-88.46%; false-positive cases-11.53%; false-negative cases-8.19%. Immunofluorescence proved specific, sensitive, practical and rapid method detection of non-sporulated anaerobic organisms species and subspecies belonging to Bacteroides fragilis group.

Agglutination Tests↗