Zentralblatt fur Bakteriologie. 1. Abt. Originale. A: Medizinische Mikrobiologie, Infektionskrankheiten und Parasitologie最新文献

In the first communication (3), we reported on the conception, the composition, and the efficacy of the polyvalent oral vaccine from 6 strains of salmonellae, 2 strains of shigellae, and 4 strains of dyspepsia coli. The inactivation took place at 100 degrees C/3 min. The question going to be answered in this communication was as follows: Does the immunogenicity of the vaccine decreased during the gastrointestinal passage under influence of acid and enzymes? We allowed the vaccine to react with simulated gastric juice and/or pepsin at pH = 3 and 37 C/60 min on the one hand and with simulated intestinal juice and/or pancreatin at pH = 7 and 37 degrees C/180 min on the other hand either individually or in combination. The vaccinal preparations produced this way were examined for their immunogenicity in the mouse protection test. The mice were orally immunized with the aid of a probang for ten times (total dose = 3.75 x 10(10) germs) and intraperitoneally infected with the virulent enteropathogenic strain of E. coli 2,380 being contained in the twelvefold vaccine on the 10. day after the last oral vaccination. In the main test, 70.4% of 351 non-vaccinated control animals died. 277 mice were immunized with the vaccine having been treated in the strongest way (gastric juice + pepsin + intestinal juice + pancreatin); 4.0% of those died which is an index of efficacy of 94.3. The mice immunized with untreated vaccine served as positive controls and were protected in the same way; 3.1% of 255 mice died (index of efficacy = 95.6). The results show that the simulated gastro-intestinal passage did not have a negative influence upon the immunogenicity of the polyvalent vaccine.

One hundred and forty four strains of Neisseria meningitidis were isolated from pathological specimens and from carriers. The source of material was randomized in Poland. Out of seven existing serological groups of Neisseria meningitidis, no strains belonging to groups D and X were isolated. Serological group B was dominating; strains isolated from patients comprised 68%, while strains from carriers were group B-positive in 52%. Pathological specimens revealed presence of strains belonging to groups A, B and C only. All strains were tested toward susceptibility to 31 antimicrobials (8 penicillins, 5 cephalosporins, 3 tetracyclines, 4 sulphonamides and 11 other drugs). Most effective were: penicillin, carbenicillin, amoxycillin, cephalothin, and sulphonamides. Some sulphonamide-resistant strains, especially belonging to serological group C and to a lesser extent to group B, have been isolated.

Lipase and phospholipase C from Staphylococcus aureus could be isolated by gel filtration on Sephacryl S 200 (Fig. 1a, b) and completely separated by refiltration under the same conditions. Isoelectric focusing gave maximal enzyme-activities for lipase at pH 8.6 and 9.5 and for phospholipase C at pH 7.4 (Fig. 2). Thin-layer chromatography revealed that the reaction products in lecithin agar of the phospholipase C-preparations from S. aureus and Bacillus cereus were identical (Table 1).

The occurrence of histidine degrading enzymes in whole cells of mycobacteria and nocardia was investigated. Out of 25 Mycobacterium strains, only M. smegmatis showed "histidase" activity, i.e. an uptake of histidine and a simultaneous release of ammonia. Consequently, the presence of "histidase" is a characteristic feature for M. smegmatis. In contrast to "histidase", single mycobacteria strains were able to take up histidine from the reaction mixture without liberation of ammonia or detectable oxidation of the substrate. This property was not species-specific. Therefore the determination of the released ammonia is decisive for the determination of the species-specific "histidase". Strains of the genus Nocardia proved to be more active concerning "histidase". Out of 18 species we found activity in all 4 N. erythropolis strains and in 7 out of 10 N. asteroides strains; the only strains of the species N. restrictus, N. opaca, N. blackwellii, N. paraffinae and R. terrae also showed "histidase" activity. Under the experimental conditions whereby 1 mmol/l of histidine and 10 mg/ml of bacteria were used, histidine was degraded by M. smegmatis within 6--8 hours; during which reaction 1,7--1,8 mmole/l of ammonia was released and 5/2--6/2 mmol of oxygen consumed. Other metabolites, such as urocanic acid or glutamic acid were not released in the reaction mixture. The kinetics of the degradation by whole cells was investigated in detail; the Michaelis constant was 0,53 . 10(-3)M, the optimal temperature found at 43,2 degree C, below and above which temperature the activation energies were 5177 and 11806 cal, respectively. "Histidase" is inducible in M. smegmatis. After cultivation of the bacteria on media containing histidine or urocanic acid, the enzymatic activity strongly increased. The same effect could be obtained by preincubating washed cells in buffer containing histidine or urocanic acif for 4 hours. "Histidase" was inhibited by streptomycin, viomycin and p-chlormercuribenzoate. The degeneration pathway is supposed to start from histidine via urocanic acid and glutamic acid; thus the proposed pathway is different from that one suggested by Bönicke (1964). Details of the degradation pathway using partially purified enzyme preparations will be described latter.

Lipase and phospholipase C from Staphylococcus aureus of different origin were demonstrated qualitatively by agar diffusion on tributyrin- and lecithin agar. On test media with either 0,3% Na-azide or 0,3% KCN lipase-activity was not inhibited, phospholipase C, on the other hand, completely blocked (Table 1, Fig. 2). In this manner a tentative differentiation was possible between lipase and phospholipase C. For the quantitative determination of lipase the hydrolysis of p-nitrophenyl palmitate proved to be most useful (Fig. 1). S. aureus-cultures of human origin produced more often and more actively lipase and phospholipase C than those from cattle (Table 2).

Escherichia coli K88ab and K88ad antigens were isolated from K88 antigen-producing E. coli K12 transconjugants and purified by means of repeated column chromatography. Injection of about 1 to 2 mg of the purified antigens into rabbits yielded specific K88ab and K88ad antisera. Attempts to obtain specific K88ac antiserum by means of this procedure failed.

A modified blood residual nitrogen plate auxanographic method was applied to the detection of experimental uremia in a murine model. The yeast-like fungus, Cryptococcus neoformans, was used as the indicator. Transient uremia was induced by injection of 0.2 ml glycerol intramuscularly. The low molecular weight nitrogen levels were estimated by measuring the diameter of the auxanogram at intervals of 2 hr for 24 hr and at 32 hr after the glycerol injection. After 4 hr, elevated levels of low molecular weight nitrogen were found. Maximum levels occurred 20 hr post glycerol injection. This method requires only 5 microliter of whole blood per assay. The results can be read after an incubation time of 24 hr at 26 degree C. The stability of the prepared plates was determined to be at least 96 hr at 4 degree C. The ease of use, reliability and versatility of the modified auxanographic method are discussed.

Extracts from supernatants, obtained from culture of virulent strain PB-3 and saprophytic strain Isola Sacra 1, were assayed for cytotoxicity. A cytotoxic factor produced by the pathogenic strain was found to affect specifically the tested cells, at determined concentrations; on the other side a not clear and scarce cytotoxicity was shown for the extract from the saprophytic strain Isola Sacra 1. Cytotoxic factor produced by strain PB-3 was heat resistant and trypsin sensitive, suggesting to be a thermostable protein. An inhibitory doses it induced a typical, cytopathic effect on the treated cells.

The statistical interpretation of the isolation of 3,581 Salmonella strains belonging to 30 species or serovars (S) shows that the efficacy of selenite and tetrathionate broth as enrichment media was of similar magnitude for 631 strains for 13 S. The tetrathionate broth was better in the case of 2,520 strains from 11 S and the selenite broth in 430 strains from 6 S including the two pathogenetic most important species S. typhi and S. schottmuelleri. Therefore, this point needs the unconditional use of selenite broth (Table 2). Wilson-Blair agar was more efficient than Leifson agar in the isolation of the most salmonella (Table 2). Also the percentage of suspicious and false-positive colonies on Leifson agar is higher and is due to more expensive work than on Wilson-Blair agar (Table 3).