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Biomedical subjects

G J Tuschewitzki

Publications and source records attributed to G J Tuschewitzki.

At least 19 recordsLinked to original sources
PubMed1995

Indicators for microbiologically induced corrosion of copper pipes in a cold-water plumbing system.

Corrosion damage in the copper cold-water plumbing system of a large building was investigated. An unusual combination of corrosion patterns was found on the inner copper pipe surfaces that were in contact with water. Damage was in the form of shallow cavities, a surface cover or pinprick-like pits. The corrosion system was influenced by thermal treatment and also by cefoxitin dosing. The latter fact in particular is a clear indication of microbiological involvement in this corrosive action. Different parameters, to be measured in standing water (24-h stagnation), are considered typical for this type of corrosion: the detection of Sphingomonas spec. and other species in whose cell wall regions copper can accumulate, a copper content of more than 2 mg/l, oxygen consumption of more than 4 mg/l and an increase in pH. With the help of these indicators, it is possible to recognize microbiologically induced corrosion in copper plumbing systems before pipe perforation occur.

Bacteria↗
PubMed1992

In vitro investigations into the formation and dissolution of infection-induced catheter encrustations.

Encrustations are the most frequent complications occurring with indwelling catheters and urine drainage systems. The conditions for bacterial infections, using synthetic urine and controlled contamination by Proteus vulgaris, were standardised by using an in vitro model. Crystal deposits on catheters were analysed by infra-red spectroscopy and scanning electron microscopy. The main components of deposits in all investigations were struvite (MgNH4PO4.6H2O) 60-70% and carbonate apatite (Ca10(PO4,CO3)6 (OH,CO3)2) 30-40%. Investigations as to the quality and quantity of encrustations confirmed the analysis. Irrigation treatment was carried out with physiological saline solution and citric acid solution (Suby G) to study and quantify the dissolution of crystal deposits. Regular irrigation with citric solution resulted in a 70% dissolution of encrustations and ensured free flow as ascertained by measuring flow rates.

Animals↗
PubMed1990

[Hygienic measures in endoscopy].

Risks of infection associated with endoscopy, sources of infection, relevant microorganisms (P. aeruginosa, Serratia, HIV, HB, Cryptosporidiosis), disinfection procedures and the steps of disinfection procedures and reasons for failing of disinfection procedures are discussed. Channel systems and rinsing solutions are relevant but until today underestimated sources of infection. In detail the contamination of the channel system in endoscopes, problems of good disinfection and the significance of mechanical cleaning are described. In cases of Pseudomonas aeruginosa infections after endoscopy an immediate investigation of the contamination of the endoscope and of rinsing solutions is necessary. Automatic disinfection systems are requested, because with such systems a higher security for patient and personal is achievable. A regular control of the efficacy of the disinfection process by a competent Hygiene-Institute is recommended.

Cross Infection↗
PubMed1990

[Transmission of "barber's itch" by bathing?].

Pathogenic fungi find a favourable environment in baths for multiplication and distribution. So diseases caused by dermatophytes are often observed in connection with a visit of a bath. With regard to transmission of a "barber's itch" caused by fungi in consequence of the visit of a bath, there have still no results been published. Considering previous knowledge about epidemiology, mechanism of invasion, living, and multiplication of pathogenic fungi it seems unlikely that a transmission of the germs of "barber's itch" takes place due to the visit of a public bath. The expression "barber's itch" is not uniformly used; thus, if visitors make complaints about this affection, an etiological differentiation is required.

Arthrodermataceae↗
PubMed1990

[Examination of sewage for nitrification inhibitors with the help of a simple and accessible bioassay].

The biotest presented permits the investigation of sewage as for the presence of nitrification-inhibiting substances. A waste-water sample has to be aerated together with activated sludge for 5 h. The concentration of ammonia and nitrate will be analysed at the beginning and the end of the test. The intensity of nitrification can be detected comparing the increase of nitrate in the sewage sample with a control. In order to verify the reliance of the test the effect of different parameters on the test system like pH, BOD of the sludge, content of ammonia, nitrite and nitrate and different sewage-relevant compounds were investigated. The biotest was successfully applied in order to find out the inhibition of nitrification in a communal purification plant. An emission of nitrification inhibiting substances was determined by screening of the supplies of the purification plant.

Ammonia↗
PubMed1990

[Induction of a microbial colonization of the walls of copper pipes through which drinking water flows].

Bacterial colonization developed within one month on the surface of a copper pipe used for the transport of drinking water. No severe signs of corrosion could be detected within six weeks. Dividing cells and the formation of microcolonies indicated active metabolism and multiplication of the bacteria and not only a more or less passive adsorption on the copper from the bulk phase.

Bacteria↗
PubMed1989

Experimental investigations on dissolution of incrustations on the surface of catheters.

On the basis of a standardized in vitro irrigation model, the incrustation behavior of catheters was investigated using collected urine with controlled contamination (Proteus, mirabilis). Irrigation treatment with a NaCl solution did not effectively reduce incrustation compared to the control experiment. On the other hand, incrustations were definitively prevented or existing crystal deposits were largely dissolved with a citrate solution of pH 4.0 (Suby G). Analytical investigations (infrared spectroscopy, scanning electron microscopy) of the deposits on the catheter revealed the presence of struvite (MgNH4PO4 x 6H2O), brushite (CaHPO4 x 2H2O) and carbonate apatite (Ca10[PO4] [CO3OH]6[OH]2).

Catheters, Indwelling↗
PubMed1987

Influence of biofilms by chemical disinfectants and mechanical cleaning.

Water conducting systems in hospitals (endoscopes, nebulizers, tap water systems, dental units etc.) are often important reservoirs of conditional pathogens. The sanitation of those systems by in vitro efficient chemical disinfectants is very difficult. An explanation may be that microorganisms are growing in such systems in wall adhering biofilms wherein they are protected from biocides. A method for testing the efficacy of chemical disinfectants and mechanical cleaning is described under conditions which imitate those in natural systems. A criterion for the efficacy of sanitation procedure is not only the good disinfection result but also the removal of biofilms. The investigation showed that aldehydes, and peracetic acid can reduce multiplying microorganisms without disrupting the biofilm. A preparation on the basis of hydrogen peroxide showed good antimicrobial efficacy and a distinct reduction and influence of the biofilm. The best result was achieved by mechanical cleaning. The test model is simple and a supplement to the conventional in vitro laboratory test for the efficacy of sanitation procedures of water conducting systems.

Aldehydes↗
PubMed1986

[Microbiology of ground water and drinking water].

Groundwater has been considered a safe source for drinking water protected against surface contamination. However, a number of reports about chemical and microbiological contamination have disproved this assumption. Besides hygienical monitoring, little is known about the microbiology of ground- and drinking water. The purpose of this paper is to give a review about the main fields of investigation concerning microbial activity in ground- and drinking-water-action. The hygienical relevant topics are: survival and transport of microorganisms, microbiological degradation of organic pollutants, turn-over of nitrogen compounds, oxidation and reduction of iron and manganese and development of methods for microbiological water examination.

Fresh Water↗
PubMed1984

[Adhesion of mircroorganisms to respirator tubes].

Potentially pathogenic microorganisms may adhere to and persist on plastic surfaces by extracellular polymeric substances. Intubation tubes used between 30 minutes and 10 days in 14 ventilated patients of a medical intensive care unit were examined by scanning electron microscopy. All interior tube surfaces showed heavy colonisations which thus can persist over prolonged periods. The clinical relevance of these findings consists of the fact that, as on other plastic surfaces, microbial organisms may remain attached to ventilation tubes. Through formation of extracellular polymeric substances they are protected against effects of antibiotics and disinfectants. Aspiration of these microorganisms from the tubes may lead to pneumonias in ventilated patients.

Adhesiveness↗
PubMed1983

[Microbial colonization of the walls of a copper pipeline in a central disinfection dosage unit].

Part of a copper-pipe taken from an 11 years old central disinfection dosage apparatus was investigated by Scanning Electron Microscopy. The pipe was covered by a thin paste-like coating. SEM revealed two distinct layers. In direct contact to the copper a layer of extracellular polymeric substance was seen. In direction to the luminary we found a second layer consisting of bacteria which were not embedded in extracellular polymeric substance. Some of the microorganisms of this layer showed holes. Bacteria in direct contact with disinfection solution showed a rough thickened surface indicating the existence of capsule substances.

Copper↗
PubMed1983

[Induction of microbial growth on the walls of plastic tubes by drinking water].

Drinking water flowing through flexible plastic tubes (PVC) causes the development of a thin film-like coating within 24 h. At this stage microorganisms could either not or rarely be seen. After 48 h the number of microorganisms has become greater. With increasing time of experiment the microbial community becomes more dense until after 72 h it covers the whole surface. Now the microorganisms are embedded in extracellular polymeric substances. The primary film seems to be important for the development of microorganisms in equipment and apparatus.

Bacteria↗
PubMed1982

[Methylotrophic bacteria in the sphere of drinking water. 1. Communication: comparison of the bacterial count of the water derived from different treatment plants].

Raw water, biological filters as well as supply water of 11 different treatment plants were examined with respect to the occurrence of methylotrophic bacteria. Although these organisms could be found in all samples, there were considerable differences in relation to the countable numbers. Methane containing raw waters showed only very low numbers of methylotrophic bacteria, whereas after aeration and passing the biological filters the effluent contained high numbers of these organisms. No correlation could be observed between colony count of the heterotrophic bacteria and the number of methylotrophic bacteria. A rapid method for determination of the methylotrophic bacteria on solid media, using the different colony size depending on incubation with and without a C1-compound, is quite inaccurate and uncertain.

Bacteria↗
PubMed1982

[Microbial colonization of moistered bitumen and high-grade steel plaids revealed by scanning electron micrographs].

There have been some reports about the increase of colonic counts and microbial growth on the surface of materials in the sphere of tap water. But there have been no hints about the development of the initial colonization with microorganisms from the water to a growth on the surface. The development of a microbial community on high-grade steel or solvent containing bitumen was revealed in a comparative study by scanning electron microscopy. There was hardly any increase in the count of bacteria on high-grade steel during the four weeks exposition. On bitumen there was a dense and multilayered growth with bacteria. Already within one week the number of bacteria on bitumen was much higher than on high-grade steel.

Alloys↗
PubMed1982

[Methylotrophic bacteria in the sphere of drinking water. 2. Communication: biochemical/physiological and morphological characterisation of the isolated bacteria].

720 bacteria from 18 water samples were isolated under conditions which are expected to be selective for methylotrophic bacteria. The water samples derived from 11 different water plants including 5 which had to treat methane containing groundwater. All isolates had been characterized by 130 properties using the morphological features of the colonies and the cells as well as physiological and biochemical tests. Numerical and classical principles of taxonomy were applied to the data. Only 20% of the isolated bacteria pointed out to be methylotrophic, even the portion of obligate methylotrophic organisms was only 1%.

Bacteria↗