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

Rapid killing of Yersinia enterocolitica strain 75 in smooth form (Ye 75 S) was observed in the presence of serum or of lysozyme-free serum whereas the killing activity of EGTA-serum was slow, and absent in heated (30 min 56 degree C) serum. Similarly, complement (C) activation by Ye 75 S was rapid in serum and lysozyme-free serum but slow via the alternative pathway (EGTA-serum). These data suggest that C is sufficient for killing of the cells and most active via an intact classical pathway. Electronmicroscopic studies were performed on bacterial killed by serum (C + lysozyme) or by lysozyme-free serum (C). In these experiments cell fragmentation and spheroplast formation were seen after exposure of Ye 75 S to serum; in bacteria incubated with lysozyme-free serum "blebs" formation was observed as the most prominent alteration. These blebs most likely originate from the outer membrane as a result of C activation on the cell surface. The deposition of activated C (C3b) on Ye 75 S was analyzed kinetically in the presence of serum or EGTA-serum. With serum (30 vol%) massive C3b deposition was observed within 20--30 min whereas with EGTA-serum (30 vol%) the deposition of C3b was slower and less complete. Experiments with EGTA-serum also revealed that the deposition of C3b started at single sites mainly located in the region of the cell poles; from these sites spreading of C3b occurred until large areas of the cell surface were covered. These data suggest that C activation via the alternative pathway is restricted to certain regions of the bacterial surface.

As part of the epidemiological investigations on Salmonella ion the former island of Walcheren, the contamination of sewage water in the village of Aagtekerke was studied over a prolonged period of time. These studies showed that this sewage water was frequently contaminated by large numbers of Salmonella. In the present study efforts were made to find the source of this contamination and for this purpose the incidence of Salmonella in the sewage system, in the faeces of man and pets as well as in shops, kitchens and lavatories in the village of Aagtekerke was studied for a period of three weeks in June 1977. Salmonella was only isolated from a few samples of faecal material of human and animal origin, and from the sewage system (including the inlet water and effluents of the sewage works). Serotyping showed that the strains isolated from human faeces were similar to those found to be present in the sewage system. This fact taken in conjunction with the results of the bacterial counts, suggests that the sewage system was only contaminated by a small number of carriers. The reduction of contamination observed in the sewage system during the period of investigation could be evidence that Salmonella organisms cannot survive by themselves in an environment of this type, at least not at the temperatures recorded when collecting samples from the sewage water. Growth of organisms under more favourable conditions cannot be ruled out. A questionnaire about the dietary habits and kitchen hygiene of the local population showed that contamination within households, originating with the food, is a real possibility.

An early symptom of lysozyme treatment of developing actinomycete microcolonies is hyphal tip swelling, illustrating the plasticity of this region in relation to filament extension. The reaction is not limited to true mycelia of Streptomyces, Streptoverticillium and Rhodococcus but is also characteristic of unbranched filaments of actinomycetes exposed during their elongation stage. On the other hand rods whose extension has ceased and which are undergoing fragmentation do not show any localized weakness but a generalized lysis. Results are discussed with reference to polarity of growth in actinomycetes.

An enzyme immunoassay (ELISA) from SEROMED was tested for its suitability in detecting HBeAg and was compared with a radioimmunoassay (RIA) from ABBOTT and with rheophoresis. From a total of 931 sera tested, HBeAg could be detected in 313 sera with ELISA, 347 sera with RIA and 22 sera with rheophoresis. When 8 HBeAg containing sera were titrated for end points, RIA gave titers which were 2.3-fold higherr than ELISA and 575-fold higher than rheophoresis. The differences between RIA and ELISA were shown to be due to somwhat lower sensitivity of ELISA. However, when sera from patients with Hepatitis B from various times after the onset of hepatitis (maximally 12 months) were tested, there was only a slight difference in sensitivity between ELISA and RIA. ELISA along with RIA is considered to be a substantially sensitive test for detection of HBeAG as compared to rheophoresis and can be recommended for routine use.

The aerobic gram-negative faecal flora of 38 bats consisting of 10 species and genera respectively, of Microchiroptera, and of 4 species and genera respectively, of Megachiroptera was studied (Table 1 and 3). There were no specific differences between Insectivora and Frugivora: E. coli 15-24%, Citrobacter 8-10%, Enterobacter-Klebsiella-group 40-43% and Proteus-group 28-30% (Table 2). The overwhelming majority of the isolated bacteria were lactose-positive (Table 3), corresponding to the membership of the bats to the mammals. The vampire bats (Desmodus rotundus), however, nourishing exclusively with mammalian blood, possess a fundamental other faecal flora. Here we always found Aeromonas hydrophila sometimes as a pure culture and sometimes in combination with E. coli, Enterobacter, Providencia, and Arizona. The normal habitat of Aeromonas hydrophila in vampire bats suggests that these bacteria are necessary for digest the drunken blood in a similar manner as in leechs. The observations were discussed regarding their ecological, epidemiological, and phylogenetic significances.

19 weakly saccharolytic Bacteroides strains of different species were tested by thin-layer chromatography (TLC) for their fermentative abilities for fructose, sucrose, lactose, galactose, and raffinose. Conventional fermentation tests were run parallel. In general, a good agreement between both methods was recorded. Two strains, however, showed a degradation in the TLC test without an acidification. With some strains, sucrose as a substrate yielded a fructose spot, lactose a galactose spot, and raffinose a melibiose spot, indicating an incomplete degradation of these carbohydates.

The effect of Fosfomycin on K. pneumoniae ATCC 10031 was studied. The morphology on the electron microscopical level and the viability were markedly altered after application of 6 micrograms/ml and 60 micrograms/ml of Fosfomycin, respectively. These were chosen because they can be attained in man by oral or parenteral administration. Until 30 min after the administration of 6 micrograms/ml, and 10 min after administration of 60 micrograms/ml the turbidity increased in the same range as in the control. Thereafter the turbidity decreased but did not fall below its minimal values; after application of 6 micrograms/ml of Fosfomycin the OD remained at higher levels than after applying 60 micrograms/ml of Fosfomycin, at all corresponding times. The number of viable cells, after application of 6 micrograms/ml of Fosfomycin, was maximally reduced for 70% of the value at the time of administration. 60 micrograms/ml quickly impaired the ability of reproduction. Consequently, the CFU were reduced continuously, e.g. by 80% after 30 min and by more than 99% after 180 min. The finestructural alterations were characterized by loss of contrast and regular shape. The occurrence of protruded protoplasts and defects in the cell wall indicate the action of Fosfomycin on the bacterial envelope, preferably on the peptidoglycan layer.

The revertants were isolated from the antigenic variants of Leptospira interrogans serovar copenhageni Shibaura by plating the variants on the solid medium containing the homologous immune serum, and by noting the growth of small colonies. The revertants which produced the small colonies were antigenically identical with the parents. The variants which retained their antigenicity for 2 to 3 years produced only a small number of revertants. On the other hand, the variants which phenotypically changed to the parent during the same period of maintenance produced many revertants. The revertant-clones and the variant-clones showed a similar generation time. No revertant was isolated from the variants of hebdomadis Hebdomadis.