Influence of sequential cultivation on virulence of Legionella pneumophila and Staphylococcus aureus.

Virulence of Legionella pneumophila strain Monza 3 and Staphylococcus aureus strain Smith diffuse was investigated after sequential cultures on nutrient media. L. pneumophila lost its ability to multiply within Acanthamoeba polyphaga after 50 passages on Legionella selective agar, while S. aureus maintained its pathogenicity in the mouse peritonitis model after 100 sequential cultures on tryptic soy agar. These results demonstrate high preservation of virulence in staphylococci in contrast to legionellae. Differentiation of virulent and avirulent phenotypes of legionellae by the protozoal model may be helpful for detecting sources of infection in water hygiene.

Sequence analysis of bacterial DNA in the colon and stomach of the Tyrolean Iceman.

The male human body found in an Alpine glacier on September 19, 1991 ("Tyrolean Iceman") has, for the first time in history, given scientists a chance to perform detailed anatomical, histological, and molecular investigations on the organs of a person from the Neolithic Age (5350-5100 B.P.). In the present study, tissue samples aseptically taken from the stomach and the colon of the mummy were utilized for DNA extraction, and the DNA was PCR-amplified, using primer pairs designed to bind to fragments of the 16s ribosomal RNA gene (16s rDNA) of a broad range of bacteria. The PCR products were cloned in plasmid vectors, and the recombinant clones (amplicons) were sequenced. The sequence data were finally used for scanning data libraries containing the corresponding sequences of present-day bacteria, to infer the putative ecophysiology of the ancient ones. The same procedure was repeated on some fragments of grass from the clothing found near the corpse. These fragments were taken as a control of the microbiological situation of the glacier. The results show that the flora of the Iceman's stomach is entirely composed of Burkholderia pickettii, an organism commonly found in aquatic habitats. The colon, on the other hand, contains several members of the fecal flora of humans, such as Clostridium perfringens, C. ghonii, C. sordellii, Eubacterium tenue, and Bacteroides sp. The Iceman's colon, however, was found to contain, rather unexpectedly, also some members of the genus Vibrio. The results are discussed in light of what is known about the preservation of microbial DNA at the Iceman's site and of previous parasitological studies performed on the Iceman himself and on human coprolites.

Otorhinolaryngologic computer-assisted biopsies of the Iceman.

BACKGROUND: The Iceman is a prehistoric, completely preserved, 5300-year-old male human mummy. OBJECTIVE: To obtain the first biopsy specimens from inside the Iceman while meeting an extended standard of hygiene and following precise intraoperative guidance to the site of biopsy and keeping tissue damage to a minimum. DESIGN: Biopsy specimens from the nose, the maxillary sinus, and the larynx of the Iceman were obtained. Special caution had to be taken while performing the biopsies to not contaminate the Iceman with heavy metals or remnants of microorganisms. SUBJECT: The Iceman, a cadaver kept frozen in a glacier for 5300 years. The Iceman is in an excellent state of preservation and will allow fundamental histological, morphological, and molecular genetic insights into early man. INTERVENTION: The biopsies were planned and executed with the aid of Interventional Video Tomography, a system that guides the surgeon to the target area by combining live video with existing imaging modalities. The system does not need mechanical fixation of the subject (the Iceman) and is barely in physical contact with the subject; thus, it was the ideal tool for guiding the surgeon to the site of the biopsy samplings through a tiny canal into the nose, the maxillary sinus, and the larynx of the Iceman. RESULTS: We have obtained a number of tissue samples by precisely guided 3-dimensional navigation. Unnecessary tissue damage was avoided. CONCLUSIONS: Visual inspection of the extracted mucosa showed typical human cadaver tissue, despite its age, without clinical abnormalities. Currently, the samples are being investigated by various international scientific groups.

Legionella pneumonia in transplant recipients: a cluster of cases of eight years' duration.

Infection with Legionella is often encountered in immunosuppressed patients, especially in recipients of renal allografts. From January 1985 until April 1993 14 cases of nosocomial legionella pneumonia were diagnosed (four by culture, 10 by serological methods) on the surgical transplantation unit of Innsbruck University Hospital. All isolates from patients and from the building's hot water were found to be Legionella pneumophila serogroup 1. They were indistinguishable from each other by monoclonal antibody subtyping and restriction fragment length polymorphism pattern and thus indicated a series of infections originating from the same source during a period of more than 8 years. Repeated efforts to control Legionella by raising the temperature in the hot water lines failed to bring permanent success. Replacing the central hot water supply with small electric water heaters installed in the patient rooms on the transplant ward now seems to have reduced the incidence of legionellosis on this unit. However, further infections occurring in transplant patients in other surgical departments in the same building indicate that a major renovation of the whole surgical building's hot water system is necessary.

[Current status of bath water treatment techniques]. / Aktueller Stand der Badewasser-Aufbereitungstechnik.

The Federal German DIN standard No. 19644 that has been enforced in West Germany since 1989 had to be revised in view of the fact that German legislation is expected to issue an ordinance on swimming pool and public bath water within the framework of the Federal Communicable Diseases Act; furthermore, the need for revision also arose from the solution of the hygienic problems of treatment and disinfection of warm whirlpool water, and from the necessity of modifying several now outdated regulations. It is the aim of public health legislation to prevent health risks of bathers and of attendant staff by Legionella pneumophila in all types of basins with additional water cycles and intake of air (aerosol formation); likewise, adverse health effects of side reaction products of the disinfectant chlorine (i. e. chloroamines and halogenated organic compounds, especially the trihalomethanes) must be avoided. Recent research has shown that these aims can be achieved by altering the mode of running and backwashing filters of all process combinations including those using ozone and introducing an additional absorption on powdered activated carbon, and the process combination of flocculation-filtration-chlorination. Improved treatment would be without effect if turnover rates could not be assessed reliably for basins of irregular geometry--as they are preferably used today--operated with additional water cycles involving intake of air. Lack of costly investigations prompts users to estimate turnover rates on the basis of experience collected with basins of square or rectangular dimensions.

Water-borne fungi in the River Inn, Innsbruck (Austria).

Pythium, Saprolegnia and Achlya were the basic components of the river mycoflora. Occurrence and periodicity of the fungal genera and species exhibited three different patterns during the different months of this investigation.

[The use of an enzyme-kinetic-method for bacteriological examinations of heavy polluted surface waters (author's transl)]. / Die Anwendung enzymkinetischer Methoden bei der bakteriologischen Untersuchung eines Vorfluters

The greatest fraction of nutrients dissolved in water are organic substances which are decomposed, transformed and mineralized by heterotrophic microorganisms. For this reason, investigations concerning energy transfer in an aquatic ecosystem, or practical examinations of the pollution load of surface waters, cannot be set up when based exclusively on more or less good counts of microorganisms of the production or destruction group. Above all, it is important for heterotrophic bacteria that productivity parameters for these numerical estimations are also provided. PARSON and STRICKLAND were successful in measuring the uptake of organic material in waters with uptake-kinetic methods; HOBBIE and WRIGHT developed a method for measuring the uptake of marked test-substrates in certain concentration ranges. As a result, for these substrates it was possible to measure the turnover in natural populations. Consequently, after frequent improvement of the technique in determining the decomposition rates of individual organic substrates, a way was found not only to determine static descriptions of an aquatic biotope, but also to make possible a dynamic description of nutrient transfers. The kinetic parameters computed from these measurements are: the maximum uptake velocity (Vmax), the turnover velocity (Tt) and the transport constant (Kt) (Michaelis Constant). The maximum uptake velocity of a substrate can be regarded as the "heterotrophic capacity" of the biotope for this substrate. One restriction is, however, that only quickly assimilatable substrates can be used, as for example hexoses, organic acids, amino acids, etc. Since this technique was tested practically only in oligotrophic waters, this study undertakes to investigate its applicability in polluted biotopes and to answer the question whether a decomposition gradient is reflected in the kinetic data. A small eutrophic lake in the eastern section of the Holstein Lake District (350 ha, 9.5 m mean water depth) was chosen as the test biotope. Emptying into the lake was the runoff of a biological water treatment plant with 12,000 population equivalents and without notable business and industry. In a rectangular investigation area at first with 30 sampling stations positioned close to the outlet of the water treatment plant into the lake, kinetic tests were carried out in 48 hour intervals and then compared with bacteriological, chemical and meteorological sample results taken at the same time. Two typical result-blocks are illustrated (Fig. 1-4, 5-8). The first shows four successive test days with periodically strong wind and light to fairly strong but short periods of precipitation. The second block illustrates conditions during a following period of fair weather with only very light wind intensities. The corresponding conditions of the stratification of the drainage water in the investigation area are illustrated by the distribution of coliform organisms. In two other tables the kinetic parameters and individual, dominant data are contrasted numerically...

[Microcalorimetric investigations in polluted surface waters (author's transl)]. / Mikrokalorimetrische Untersuchungen im Vorfluter

The hygienic control of polluted surface waters has to be correlated with measurements of the decomposition rate of heterotrophic microbial populations. Starting in 1970 different methods have been tested for this purpose. Uptakekinetic studies of radioactive labelled substrates as well as automated BOD-registrations can not be handled as flow systems. Flow-Microcalorimetry (heat-conduction-principle) could be an easier approach to test the activity of heterotrophic aquatic populations. Probes from a trickling-filter outflow, from an oxidation pond and from a small river were tested simultaneously in a Flow-Microcalorimeter (LKB, 2107, Fig. 1) and a Drop-Microcalorimeter (WADSO, 1974 (fig. 2)) after adding 200 mug/L of Glucose. The resulting voltage/timecurves (Fig. 4,5,6) show a good correlation to the heterotrophic capacity of the probes. The minimal detectable continnous heat effect was 1 muW corresponding to a (relative) activity of 5.6-10(4) bacterial colonies/ml on Difco agar (counts after 48 hours incubation at 22 degrees C incubation temperature). A modification of the Flow-Microcalorimeter using a 5-10 times larger reaction vessel could enable the system to be used also in testing scarcely polluted surface waters and for toxicity tests of surface water samples.

[Biolgical problems of a manmade small lake (author's transl)]. / Zur Biologie eines künstlich entstandenen Kleinbadesees

In connection with an intensive hygienic supervision of public bathing facilities and the attempts to draw up a law on bathing hygiene, the lack of contamination standards for small lakes available to the public for bathing was particularly conspicuous. In addition to the current chemical and bacteriological routine examinations, a small bathing lake with a surface area of 3000 square metres containing about 7000 m3 of water and which has been in existence for over 10 years was objected to extensive biological investigations during the months July to September. The results of the analysis show a relatively constant hydrogen ion concentration (pH 8.2), small variations in electrolytic conductivity and 8 German degrees of hardness. The mean phosphourus level was 60 mug/L. the orthophosphate levels ranged between 5.2 and 18.5 mug/L. Oxygen saturation during the entire summer months was more than 100%. Altogether, 49 different kinds of phytoplankton- and 12 kinds of zooplancton-organisms were identified. The total biological mass of phytoplancton organisms was between 8.5 and 16 mg fresh weight per litre, bacterial biomass varied between 4.5 and 9.5 mg/l. Particularly striking for summer conditions was the high proportion of Cyclotella- and Synedra species among the phytoplancton mass, while the algal-bloom producing Microcystis flos aquae attained a maximum proportion of 15%. In spite of the great variety of its forms, green algae were present in small numbers only. The comparison of the described findings with the trophic-systems of HUTCHINSON, NYGAARD and RAWSON indicated an eutrophic type of lake; classification according to the types of the various saprobic systems of NAUMANN, KOLKWITZ and LIEBMANN yielded a predominantly beta-mesosaprobic type of lake. The investigations described show, however, that this is probably a lake rich in nutrients, but that there is a relatively stable biological equilibrium and that, consequently, there is no further threat of progressive eutrophism. Special hygienic parameters, contamination due to visitors and phytoplancton production will be reported in a second communication.

[Randomised investigations of some Tyrolean swimming pools for the presence of Trichomonas vaginalis and pathogenic fungi (author's transl)]. / Stichprobenartige Uberprüfung einzelner Tiroler Schwimmbäder auf das Vorkommen von Trichomonas vaginalis und von pathogenen Pilzen

Trichomonads were not demonstrated either microscopically or by culture in water samples from 15 public open air swimming pools in the Tyrol. On the other hand, a small number of pathogenic fungi (Candida albicans, Trichophyton mentagrophytes, Tr. verrucosum) were cultured from pool water with a free chlorine content of less than 0.35 mg/l (DPD 1). Dermatophytes could also be demonstrated by cultures of the coatings on the surfaces of tiles in the showers, and of pool surrounding-and cabin tract floors. (Candida albicans, Trichophyton mentagrophytes, Epidermophyton floccosum, Scopulariopsis brevicaulis).