Zentralblatt fur Bakteriologie, Parasitenkunde, Infektionskrankheiten und Hygiene. Erste Abteilung Originale. Reihe B: Hygiene, praventive Medizin最新文献

The capillary moisture of the gray layer of the Sphagnum magellanicum ass. contains nutrients for the growth of mycobacteria. Tested in vitro significant multiplication was stated in M. intracellulare, serotyp Davis, M. avium, M. scrofulaceum, M. fortuitum, M. xenopi, M. kansasii, M. borstelense, M. flavescens, M. gaxtri, M. gordonae, M. marinum, M. terrae, M. smegmatis, M. spec. "S" and M. nonchromogenicum (Fig. 1 and 2). There was no evident multiplication in M. phlei, M. triviale, M. tuberculosis, M. bovis, and M. ulcerans in vitro. Using the cultivation of mycobacteria in the hollow fibers (pore size 100,000 mol. weight) inserted directly in the gray layer of the Sph. magellanicum ass. a significant growth of all 18 species investigated was stated (the same species as above, excl. M. bovis and M. tuberculosis; Fig. 3). A rapid multiplication was detected also in M. ulcerans. The sphagnum vegetation spreads over all continents. It develops very good under wet conditions surrounding springs and brooklets in the moutain region. Accumulation of solar heat directly under the surface of this vegetation makes possible a temperature 15-28 degrees C higher than the air temperature. In this way favorable conditions for mesophilic mycobacteria arise over an extend period of time. The close contact to water contributes to the wide distribution of mycobacteria.

Three standard variants of intensive care units are described. The hygienic-microbiological examinations of the patients' surrounding show in how fat architectural factors influence the propagation of germs responsible for nosocomial infections. The results are hygienic requirements concerning the architectural functional structure of intensive care units to facilitate the maintenance of anti- and asepsis for the nursing personal.

The microflora of the air in university lecture rooms was examined with the sedimentation method. For this purpose blood agar (20 degrees C and 37 degrees C), saline agar and Endo plates were used. The germ counts identified correlate to the size and utilization of the rooms. The lowest germ count was determined in the room used for practical work, which was followed by the lecture room. The newly built lecture room contained the highest colony count. The floor ventilation furnishes an explanation for this. Most of the colonies were Gram-positive cocci (micrococci, indifferent streptococci, sarcins). Aerobic spore-forming organisms were found to be present in smaller quantities than cocci. Fungi, mainly, moulds grew better at a temperature of 20 centigrade. The microbiological monitoring of air forms an important part of environmental protection. Great importance can be attached to a stardization of the air germ count in the prevention of airborne infections.

This paper is concerned with the measurement of first order rate constants for the death of bacteria by chlorine and ozone. While the first order conditions for chlorine were achieved with the aid of a new instrument which works basing on the polarographic principle this was attained for ozone under steady state conditions. Besides differences of species some different properties for both oxidants were found as far as their bactericidal efficiency is concerned. They are discussed in this paper.

The relative proportion of eight polycyclic aromatic hydrocarbons (PAH) in suspended particles from several sampling stations with different level of air pollution (cities and rural districts) was investigated. The PAH-profiles of most samples collected in three winters (1974/75, 1975/76, 1976/77) and in one summer (1975) were very similar. On the other hand the PAH-profiles differ distinctly from those of several exhausts, especially regarding automobiles, coke and oil stoves. It can be presumed, that the mixture of the emissions in the atmosphere leeds to a rather uniform relative proportion of the eight PAH in the immission as much as the difference in stability of the PAH.

The different effects of homogenisation of four commonly used homogenisating apparatus, such as Stomacher, Ultraturrax, Waring-Blender, Bühler-homogenisator) were compared with each other by applying 1 artificially and 6 naturally moulded, non-fluid food products. Furthermore the influence of sedimentation in the homogenisate as well as the time of homogenisation was examined. One part of the examination was the direct microscopic observation on stained Breed-smears, the other part the cultural methods (number of mould plate count on malt extract agar). The homogenisation effect of the Stomacher was as good as with all other mentioned apparatus with the food products applied, except for the home-made smoked sausage. With this home made smoked sausage, much better results were obtained by these homogenisating apparatus, especially by the Bühler Homogenisator. This is due to the fact that the sausage was minced to a much higher degree and thus the inner mould flora was set free.--A more tender effect of the Stomacher on hyphal elements could not be achieved.--Prolonging the time of homogenisation from 1 minute to 2 up to 4 minutes did not give any better results.--A short sedimentation of coarser food particles facilitates the pipetting of the homogenisates without influencing the mould counts.--The naturally moulded foods, which were kept at room temperature for several weeks, showed a significantly smaller number of plate count than of total mould count in contrary to those foods moulded just before experimental beginning.

Effluents from different sewage treatment plants were disinfected, using hydrogen peroxide in concentrations varying between 500 and 50,000 ppm. With a concentration of 5,500 ppm H2O2 and a contact time of 2 h more than 99% of bacteria were killed, including enterobacteria, total and fecal coliforms (Fig. 1 A, B, C and D) and fecal streptococci (Fig. 2 B). Staphylococci and micrococci were less sensitive and contact times of 2 h were not sufficient to kill 99% of this group (Fig. 2 A). Highly resistant were bacterial endospores (Fig. 2 C). With a concentration of 5% H2O2 50% of the spores still survived after a contact time of 2 h (Fig. 2 D). The effect of 5,500 ppm H2O2 by an exposure time of 2 h was then studied with other effluents. The results show that total counts were also reduced for 90% and some groups for more than 99% (table 1). There was no difference in reduction between catalase positive and catalase negative micro-organisms, indicating that the catalase activity of the bacteria offered no special resistance towards hydrogen peroxide in the concentrations used (table 2). Although the observations of some investigators have shown that metal ions act to increase the bactericidal effect of H2O2 as a result of formation of hydroxyl radicals, the additions of ferrous ions (5,25 and 50 ppm) did not improve the killing activity of H2O2 (table 3).

Effect of zinc on the osmotic fragility-stability of human erythrocytes in hypotonic NaCl solutions and on the reversion of hemolysis was studied in vitro. Erythrocytes washed in 0.9% NaCl were incubated in 1.5 X 10(-3) M ZnSO4 solution in 0.6% NaCl. The obtained results indicate an osmotic stabilization of the erythrocyte membrane by Zn2+ ions increase in osmotic fragility-stability in hypotonic NaCl solutions and increase in reversion of hemolysis due to the effect of Zn2+ ions. As the process of stabilization of the erythrocyte membrane by zinc ions was found to be independent of temperature, a non-enzymatic character of this phenomenon is postulated on this basis and on the basis of literature data.

This project was to provide a further indication for the triggering of central-nervous effects by a 50 - cycle alternating field with a field strength of 5.300 V/m. Previous studies already raised the suspicion of an effector mechanism of this kind: for instance, the nucleus temperature of rats sank under field influence. The same effect is triggered in mice and rats by prescribing centrally stimulating pharmaca. Furthermore, a rise in diastolic blood pressure with a simultaneous drop in heart rate was described for human subjects. We were able to demonstrate the latter effect in laboratory animals (rats). The experiments under consideration resulted in a significant rise in norepinephrine content of the rats' brains following brief exposure of 15 min length. The measured data after 10 d fell highly significantly below those of the untreated controls and remained approximately at this lowered level until the end of field exposure (21 d). Changes in "turn over" of the norepinephrine metabolism of the brain represent an important indicator for the demonstration of the stimulation of central-nervous structures. Our findings therefore substantiate the presented hypothesis of a central-nervous point of attack by electrical energies.