Zentralblatt fur Bakteriologie, Parasitenkunde, Infektionskrankheiten und Hygiene. Erste Abteilung Originale. Reihe A: Medizinische Mikrobiologie und Parasitologie最新文献

The membrane feeding technique (in vitro feeding) used for the rearing of tsetse flies has advantages over the conventional method of feeding the flies on host animals. However, as long as blood remains the sole source of tsetse fly nutrition, the risk remains of blood being contaminated during collection, storage or feeding with bacteria pathogenic to the flies. The resulting high mortality of the tsetse flies endangers the success of this rearing. The experiments described here have shown that Glossina m. morsitans Westw. are more sensitive to Pseudomonas aeruginosa than G. p. palpalis Rob.-Desv. Rearing experiments over several years have confirmed this finding in that the latter species has never been threatened by high bacterial-induced mortality, whereas in 1973-74, due to contamination of the in vitro fed blood, a population of G. m. morsitans was difficult to colonize. The quantity of infected blood intake (14 to 70 mg) had no influence on the survival rate. However, when flies were infected once with Pseudomonas aeruginosa (dilution stage of 10(-3)), the organisms were eliminated after only nine days in living G. p. palpalis, but after 14 days in living G. m. morsitans. Females were infected at different stages of pregnancy but the same bacteria were not isolated in any puparia. Therefore, transmission of the bacteria to larvae growing in the uterus could not be demonstrated. All antibiotics used, to which bacteria isolated from tsetse flies in the laboratory were sensitive, caused a reduction in productivity. Parental females as well as females which emerged from larvae deposited by these flies (= F1-generation) 6 days after the administration of the drug to the pregnant females showed a similar loss in productivity. This corresponds with a degeneration of mesenteric symbionts. The most successful way to cope with bacterial infection in the membrane feeding technique in the rearing of tsetse flies has proved to be prophylactic measures, i.e. sterile membranes, sterile underlying aluminium trays and sterile blood. The methods employed at this laboratory, where up to 20 000 flies are being fed daily through membranes, have prevented dangerous bacterial infections in both species.

A hemagglutinating agent identified as paramyxovirus was isolated from the respiratory organs of a rock pigeon captured in Hokkaido, Japan. The virus was serologically distinct from the known members of genus Paramyxovirus. Of the 160 pigeons collected in Hokkaido, 6 possessed the antibodies to the virus. The virus was designated as Paramyxovirus/pigeon/Otaru/76.

Factor antisera oriented to different serovars of Listeria moncytogenes, expecially to serovar 7 and Murray grayi (Listeria grayi) were tested. It was found that the agglutination-immobilization test detects antibodies oriented to the H-antigen. By contrast, the growth inhibition test measures antibodies oriented to the O-antigen. Summarizingly, it can be stated that the following three seroreactions, each based on a different mode of action, are available for the determination of antibodies specifically oriented to the somatic or flagellar antigens of L. monocytogenes: 1. Bacterial agglutination reaction for the detection of O and H antibodies 2. The growth-inhibition test for the detection of O antibodies 3. The agglutination-immobilization test for the detection of H antibodies.

A solid phase enzyme immunoassay (ELISA) was applied for the determination of rabies virus antibodies of the immunoglobulin classes G and M in sera of 10 young adults. Vaccinations were carried out with the Essen post-exposure vaccination schedule, which is recommended by the W.H.O., with the rabies HDCS vaccine with an antigen value of 1.9. From these results the rabies virus IgM/IgG-conversion was derived. Furthermore a comparison was carried out of results obtained with the ELISA, the mouse neutralization test, the complement fixation test and the hemagglutination inhibition test. Rabies virus-IgM-antibodies were detected already three days after the first vaccination. The IgM-antibody concentration increased to a maximum at the 22nd day p.v. In sera of seven of eight vaccinees rabies virus IgM-antibody was still detectable until the 90th day p.v. Rabies virus antibodies of the IgG-class were found in the serum of 1/7 vaccinees at the 7th day p.v. A steep increase of the rabies virus IgG-antibodies was observed from day 10 p.v. to a maximum between the 30th and 40th day p.v.. The titer values varied between 1:10-1:1600. The rabies virus IgM/IgG-conversion was observed after the 10th day p.v.. More than 75% of the total antirabies virus globulin fraction belonged to the IgG-class in sera of 6 of 9 vaccinees between the 22nd and 30th day of p.v.. A preponderance of the rabies virus IgM-antibodies was seen in 3 of 9 vaccinees until the 90th day p.v.. Most sensitive for the early detection of rabies virus antibodies was the IgM-ELISA followed by the IgG-ELISA, mouse-neutralization test, hemagglutination inhibition test and complement fixation test.

The counting of nerve cells give an answer to the question whether there is a significant loss of cells in the cortex in the course of viral encephalitis. For normal animals, average cell numbers of 275.42 were counted; for infected animals divided into two groups depending on the severity of illness, 144.95 and 192.87 cells, respectively (p = 0.0001).

The serological reactions of klebsiella strains repeatedly isolated from four patients were examined. Variations in capsular antigens of strains from the same patient were mainly restricted to slight changes in the titre of quellung reactions and occasionally differences in cross-reactions were noted. In one case a strain reacted more strongly with a heterologous antiserum than with homologous antiserum after it had been resident in the bowel of a patient for five weeks. No significant antigenic variation was observed when multiple colonies from the same klebsiella culture were tested.

Dihydrofolate reductases of five species of the family Neisseriaceae were compared by means of inhibition profiles, using several structurally different inhibitors, including trimethoprim (TMP) and pyrimethamine. All enzymes were seen to be highly susceptible to the folate analog aminopterin, but exhibited moderate susceptibility to all other inhibitors tested. Approximately 200-fold higher concentrations of TMP were needed to inhibit neisserial reductases as compared to the E. coli enzyme. Besides poor penetration this is assumed to be the main basis for the low susceptibility of neisseriae to TMP. In addition to TMP all other inhibitors were also moderately active or inactive in vitro. The enzymatic differences, as seen from inhibition profiles, were statistically significant but small among all species of the genus Neisseria. Branhamella catarrhalis on the other hand was seen to be far less related to the other neisseriae, as seen by the inhibition profile of its reductase, its dihydrofolate reductase conttent, as well as by its in vitro properties.

By acid hydrolysis (0.2 n HCl) it was possible to obtain extracts from nonsporulated cells of different strains of 5 species of the genus Bacillus which were composed mainly or solely of species-specific antigens. This was the result of experiments using the immunodiffusion technique after having prepared antisera from rabbits with the aid of HCl extracts. Cross-reacting antibodies were adsorbed easily. The species-specific reacting antisera revealed the existence of group- or strain-specific antigens. Therefore HCl extracts could become helpful in serotyping strains which belong to the taxa of the genus Bacillus.

NMRI mice were immunized intramuscular, intranasal or by Aerosol, using the ethylethylenimine inactivated and polyethylenglycolconcentrated influenza virus strain A/PR/8/34 (HO/N1). Differences in the immune response resulted from all three routes. Intranasal and intramuscular vaccination were superior to aerosol application. A possible explanation for this could be the fact that relatively small amounts of the inhaled virus antigen developed antigenic activity on the mucous membrane. A single vaccination by the aerosol technique gave significant protection only, if the challenge virus was applied by the same procedure. However no protection was found after intranasal challenge. Intranasal challenge on the third day post vaccination revealed that intramuscular immunization had a significant better protective effect than intranasal immunization. However from the 5th to the 10th day post vaccination this effect reversed and intranasal vaccination became superior. This immunity persisted for the whole period of observation and it was accompained by a higher titer of local antibodies. Similar results were obtained in experiments with aerosol challenge. Here only the intranasal vaccinated mice were completely protected after the 10th day post vaccinationem while intramuscular vaccinated animals were less protected. Sera of intramuscular immunized mice revealed a higher content in antibodies of the Ig M type and less of the Ig G type compared to mice vaccinated by the intranasal route.