Zentralblatt fur Bakteriologie, Mikrobiologie und Hygiene. 1. Abt. Originale B, Hygiene最新文献

Tetrachloroethylene in a concentration of 0.05 resp. 0.1 mg/kg bw/d was offered in drinking water to a group of NMRI-mice. Besides a decrease in bodyweight an increase in the relative weight of the spleen resp. of the kidneys could be determined. The liver and the brain remained uneffected. In the offered concentration, tetrachloroethylene influenced the lipoprotein metabolism in the liver in the sense of a chronic-alcohol-toxic liver change, whereas the liver cell was not destroyed in toto. The unchanged rate of the synthesis of liver cells could be established sufficiently through the normal serum-glutamate-pyruvate-transaminase, an unchanged serum electrophoresis as a measure for the efficiency of the protein synthesis of the liver cells, furthermore a swelling of the liver and/or an enlargement of the liver could not be diagnosed. The erythropoietic system was found to be most susceptible to tetrachloroethylene. We could detect a defect like in the case of hemolytic anemia, this manifested itself in a very high increase of the lactatdehydrogenase, in an increase of the LD-isoenzyme-1, as well as in the occurrence of reactive initial stages of erythrocytes in the bone marrow and in the moderate degree of a hyperchrome anemia in the peripheral blood-count.

Two titration methods for the quantification of viruses present in the environment are compared--plaque counting and determination of the most probable number with a large number of inocula at each dilution. Titration of virus suspensions and of sewage samples showed that, for a given volume of inoculum, in most cases there was no statistically significant difference between the virus titres given by the two methods. The precision of the results was the same for the two methods. When the volume of inoculum used at each dilution differed from one method to another, the width of the confidence interval increased as the volume of inoculum decreased.

Mineralization activity of microorganisms in refuse from consulting rooms of general practitioners, E.T.N.-specialists, dermatologists, dentists, veterinarians, and in municipal refuse was estimated by means of CO2 and NH3 measurement. In comparison to municipal refuse, the refuse from medical consulting rooms released only low amounts of CO2 and NH3. Only in refuse from the veterinarians consulting rooms relative high mineralization was found, due to specific consistency (fecal contamination) of those refuse. A slight enrichment in pepton of all refuse under test resulted in a strong enhancement of the CO2 and NH3 evolution. That effect indicates either high potential mineralization activity of microorganisms in the refuse from medical consulting rooms and their relative resistance to microbial degradation.

The incidence of staphylococci in the nasal fossae of 300 food handlers working within the province of León (Spain) was studied. Sampling was carried out using a swabbing technique. For the quantitative estimation of staphylococci, a direct plating method and an enrichment procedure (MPN) were used simultaneously. Gram positive cocci that fermented glucose and were sensitive to lysostaphin (1 unit/ml) were found to be present in the noses of 201 food handlers (67%). Eighty three of them (27.6%) were carriers of coagulase positive staphylococci and 118 (39.3%) of coagulase negative staphylococci. The carriage rate of coagulase negative staphylococci was slightly higher in winter but carriers of coagulase positive strains were more frequently found during warmer months. Coagulase positive staphylococci appeared to be more often carried by males. In all instances, positive nasal cultures gave 10 or more colonies per sample. The majority of food handlers carrying coagulase negative staphylococci (64.4%) yielded counts between 10(3)-10(5) CFU per swab. Thirty four (40.9%) of the nasal carriers of coagulase positive staphylococci yielded more than 10(4) CFU per sample. The higher counts corresponded to this latter group. Preliminary enrichment did not increase the number of nasal carriers detected. Although a good correlation was observed between the results of direct plating and the MPN procedure (r = 0.87 +/- 0.04), the MPN technique gave lower counts. Thirty six (12%) individuals carried enterotoxigenic staphylococci. The incidence among carriers of coagulase positive strains was 43.4%. The enterotoxin types produced were: A (12 strains), B (8 strains), C (7 strains), D (2 strains), E (2 strains), A + D (4 strains) and B + C (1 strain). Most of the food handlers who harbored enterotoxigenic strains gave high nasal counts.

It was possible to isolate a strain of Serratia marcescens from fresh clinical bacterial isolates which was 4-6 times more resistant against formaldehyde than other strains. It was shown that the strain harbours two plasmids with molecular sizes of 58- and 90 Mdal. It was demonstrated by conjugation-, transformation- and plasmid-curing experiments that the formaldehyderesistance is plasmid mediated and transferable to E. coli. It was shown by labelling with 14C-formaldehyde that the resistant strains bind much more formaldehyde than the sensible strains.

Swimmer's dermatitides occurring in natural--accordingly polluted--waters are most probably of chemical nature. In clean waters, however, they are primarily caused by larvae of duck-flukes, the so called cercariae. In a natural pool near Biberach undetermined cases of swimmers' dermatitis have appeared. Hence a cercarial dermatitis was suspected and specific examinations were carried out. At the biological examination of the pool, many watersnails of the species Radix ovata have been found near the shore. Out of 180 collected snails 8 produced cercariae of different trematode species. Hence an infective cycle between duck and snail could be ascertained here. However, the special cercariae, producing dermatitis, could not be found. Having taken that into account the author was standing in the snail biotop without protective clothes for about 1 hour to provoke cercarial dermatitis. A few minutes later the corresponding clinical picture with an extremely strong itching developed. Papules were to be seen 12 h later, the symptoms lasted 2 weeks altogether. By different serological methods (Cercarienhuellenreaction) indirect immunofluorescent test with complete cercariae and cercarial sections antibodies against cercariae could be demonstrated in the serum of the author 14 days later. As a therapy only the symptomatic treatment of the itching is possible. In principle etiologic measures against cercarial dermatitides are possible by chemical snail control. But as a rule this is to be refused because of the severe ecological damages. However, in case of swimmers' dermatitis it is nonetheless indispensible to clarify eventual parasitogenic reasons because of the specific hygienic consequences.

The influence of pesticides on mediator release from rat peritoneal mast cells and human basophiles was studied. Mediators from mast cells and basophils are important factors in allergic and inflammatory reactions. Release of histamine from rat mast cells and human basophils is demonstrated by stimulation with dieldrin, DDT, heptachlor, heptachlorepoxid and biphenyl. This pesticide-induced histamine secretion is dose-dependent and requires Ca2+. In contrast, incubation with gamma-HCH, HCB and carbaryl produces no significant histamine release. Additive histamine secretion results from simultaneous stimulation of rat mast cells with pesticides and anaphylatoxin C5a. Further, secretion of eosinophil and neutrophil chemotactic factors from rat mast cells is induced during incubation with dieldrin, biphenyl and heptachlorepoxid. It is also demonstrated that pesticides can stimulate the generation of lipidmediators. Biphenyl, gamma-HCH, heptachlor, heptachlorepoxid, DDT and dieldrin cause the release of leukotriene C4 from rat mast cells. The possible role of these in vitro results is discussed.

Macrophages of cell line IC-21 were exposed to extracts and fractions of two samples of city smog (CSE 16 and 17) from the heavy industrialized Rhine-Ruhr-area. Cytotoxic effects of extracts and fractions were analysed in various concentrations and periods of incubation. As cytotoxic parameters were determined frequencies of mitosis and pycnosis of nuclei as well as occurrence of multinucleated giant cells. An increasing dosage of noxae showed a reduction of mitotic rate, a rise of pycnosis of nuclei and of multinucleated giant cells. For both city smog extracts these effects depended on incubation period and concentration of noxae. While the global extract of city smog no. 16 was always more effective than its fractions, with city smog no. 17 the strongest alterations were demonstrable by its cyclohexane-fraction and partly by its methanol-fraction. Based on air volume of collection both samples of city smog revealed a comparable cytotoxic effect. In relation to benzo(a)pyrene-content, however, city smog no. 17 was considerable more cytotoxic than city smog no. 16. These results confirm again cytotoxicity of city smog. It can be assumed that both samples of city smog impair defense mechanisms of the lung.

Airborne particulate matter was collected by high volume samplers at two sampling stations in Berlin (West) between March 1983 and February 1984 (immissions). The stations were choosen so that two main-sources of urban air pollution could be considered (automobile) traffic and private fuel combustion (domesticfuel). Also in February and March 1983 particles were collected from private coal firing (emissions). The collected particles were fractionated into the following particle sizes (immissions, during October 1983-February 1984): greater than 7.2 microns, 7.2-1.5 microns and less than 1.5 micron (aerodynamic diameter). The etherextractable organic matter of the particles (= EEOM) was determined and the organic matter was then separated into acidic, basic, and neutral fractions. The neutral fraction was further separated into aliphatic compounds (= AlP), polycyclic aromatic hydrocarbons (= PAH), and polar neutral compounds (= POCN) by thin layer chromatography. The mutagenic activity of all organic fractions was determined by using the mammalian microsome bioassay by Ames and was compared with the activity of a whole polar organic extract (including POCN, acidic and basic fraction), a whole neutral extract, and a whole ethersoluble organic extract. Also in February 1984 the nitroreductase specific mutagenicity on immission-stations was determined using nitroreductase deficient strains. Some compounds of the POCN-fraction, and of PAH (in comparison) were identified by gas chromatography. The following results were obtained: The neutral fraction of the organic matter amounted to 70-90% of the EEOM (not depending from particle size, immissions and emissions). The separation of the neutral compounds into AlP, PAH and POCN showed a higher amount of AlP at the collecting station which includes mainly automobile traffic. Some cancer and/or mutagenic suspect compounds were identified by the chromatographic analysis of POCN and PAH. A higher amount of several nitrogroups-containing POCN was found at the collecting station which includes mainly private combustion whereas at the station including mainly automobile traffic 1-nitropyrene was the main compound. The POCN-fraction showed the mostly highest mutagenic activity in the Ames bioassay, mainly for lung penetrating particles (less than 1.5 micron diameter). The whole organic extract (EEOM) showed a lower mutagenic activity than the POCN-fraction. Using nitroreductase deficient strains, at the collecting station which includes mainly private fuel combustion a higher reduction of mutagenicity was shown than at the automobile-traffic including measurement station.

Colonizing and anti E. coli activity of S. faecium M74 was tested by oral inoculation of cesarean derived, colostrum deprived piglets with Streptococcus faecium M74 and subsequently with a heat stable enterotoxin (ST) producing E. coli (O101 : K30 : K99 : NM). Enterotoxin neutralization and co-culture studies were also performed in vitro. Bacterial counts in 10 cm ileal segments, fluorescein antibody stained cryostat sections, as well as 0.5 micron sections from the ilea of the experimental pigs taken 16 hours post exposure to enterotoxic E. coli (ETEC) all indicated that S. faecium M74 could not colonize the ileum of the newborn pigs, in a single high (7 X 10(8) - 3 X 10(10)) dose either in TSB or in milk suspension, in contrast to the ETEC. However, S. faecium given in milk suspension resulted a marked decrease in ileal colonization of ETEC and in weight loss of piglets. In vitro experiments indicated that neither extracellular nor cell-bound products of S. faecium M74 could neutralise ST, but there was a significant reduction of pH in the TSB cultures of S. faecium that was accompanied by a reduction in ETEC counts of the mixed cultures.