[The success of hygiene in the last 40 years]. / Erfolge der Hygiene in den letzten 40 jahren.

In Germany, the last period of the Second World War and the following years were characterized by deficiencies of hygiene which had not occurred previously in Middle Europe during the 20th century. There were focuses of typhus, typhoid fever, tuberculosis, diphtheria, scarlet fever, and meningitis. Insufficiencies in the removal of faeces caused high incidences of shigellosis, hepatitis A, and ascariasis. As a result of insufficient body care, many people were infested with fleas, lice and scabies. The migration of large proportions of the population resulted in an increasing prevalence of syphilis an gonorrhea. As the population resettled, the first steps towards reorganization of public health could be done. The spread of typhoid fever was controlled by drinking-water disinfection with chlorine, repair of sewage systems, and patient isolation. The application of DDT helped to reduce scabies and pediculosis, resulting in decreasing typhus risks. During the first two decades after the war, there was a steady decrease of the incidence of infectious diseases. The reconstruction of the towns resulted in improved housing conditions and a decreasing number of persons per housing area, reducing the intensity of physical contacts of the inhabitants with each other. The nutrition and clothing situation of the population improved, which, in addition to a general rise of the standards of hygiene, brought about an increase of the individual resistance to infection. A further reduction of sporadic and epidemic outbreaks of infectious diseases was achieved by the introduction of chemotherapy and antibiotics. Increasing prosperity was accompanied by new problems of hygiene. Infectious diseases almost eradicated in West Germany, were imported by air travellers. Ten imported cases of smallpox were reported between 1957 and 1972, eight of which originated from Southeast Asia. Malaria, imported by German and foreign soldiers, had not been uncommon after the end of the war but had been easy to control by insecticides and antimalarials. As tourism expanded, a new wave of imported malaria cases was reported. In West Germany there is, however, no more spread of the disease under present conditions, cholera caused similar problems. The 1961 cholera epidemic started in Southeast Asia and caused minor outbreaks in Mediterranean countries like Italy and Spain. A significant spread of the disease throughout Europe was prevented by generally high standards of drinking water and sewage treatment. Sporadic cases of typhoid fever were imported from countries with low standards of hygiene.(ABSTRACT TRUNCATED AT 400 WORDS)

[Induction of microbial growth on the walls of plastic tubes by drinking water]. / Induktion einer mikrobiellen Wandbesiedlung in Kunststoff-schläuchen durch Trinkwasser.

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.

[Microbial colonization of the walls of a copper pipeline in a central disinfection dosage unit]. / Untersuchungen zur Wandbesiedlung der Kupferrohrleitung einer zentralen Desinfektionsmitteldosieranlage.

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.

[Methylotrophic bacteria in the sphere of drinking water. 2. Communication: biochemical/physiological and morphological characterisation of the isolated bacteria]. / Methylotrophe Bakterien im Trinkwasserbereich 2. Mitteilung: Biochemisch/physiologische und morphologische Charakterisierung der Isolate.

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%.

[Methylotrophic bacteria in the sphere of drinking water. 1. Communication: comparison of the bacterial count of the water derived from different treatment plants]. / Methylotrophe Bakterien im Trinkwasserbereich 1. Mitteilung: Vergleich der Bakterienzahlen im Wasser aus verschiedenen Aufbereitungsanlagen.

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.

[Microbial settlement of paint- and building-materials in the sphere of drinking water. 9. Communication: experimental examination of cement mortar for the lining with tiles (author's transl)]. / Mikrobielle Besiedlung von Auskleidungsmaterialien und Baustoffen im Trinkwasserbereich. 9. Mitteilung: Experimentelle Untersuchungen von Zementmörtel für Fliesenauskleidung unter Laboratoriumsbedingungen.

The observation of a microbial growth in form of macrocolonies upon the joints of a tiled drinking water reservoir caused the microbiological testing of different pure mineral and some plastic containing cement mortar. Besides the conditions allowing the growth of macrocolonies on tiled plates with a construction like in a reservoir were examined.

[Microbial settlement of paint- and building-materials in the sphere of drinking-water. 6. Communication: Experimental examination of chlorcaoutchouc paints under working conditions and in laboratory tests (author's transl)]. / Mikrobielle Besiedlung von Auskleidungsmaterialien und Baustoffen im Trinkwasserbereich. 6. Mitteilung: Experimentelle Untersuchung von Chlorkautschukanstrichen unter Praxis- und Laboratoriumsbedingungen.

Five different chlorcaoutchouc coating materials were microbiologically tested. All materials showed a visible microbial growth on the surface. The amount of slime decreased with the increase of age of the coat of paint. After a period of 1 to 1 1/2 years no visible microbial growth could be observed. The decrease of microbial growth on the coat of paint is independent on having been in contact with water or air before. One can say that the main compound of the coating material does not itself produce the visible microbial growth, but additions like volatile compounds.

[Microbial settlement of paint- and building-materials in the sphere of drinking water. 7. Communication: long time observations in two drinking water reservoirs coated by epoxy resin (author's transl)]. / Mikrobielle Besiedlung von Auskleidungsmaterialien und Baustoffen im Trinkwasserbereich. 7. Mitteilung: Langzeitbeobachtungen in zwei Reinwasserbehältern mit Epoxidharzauskleidung.

In two potable water reservoirs with an epoxy resin lining an increase of the colony count in the water and a visible microbial growth on the surface could be observed. The slime consists of bacteria and fungi. In one case higher organisms like protozoa were found too. The growth of microorganisms is caused by organic compounds of the epoxy resin which can be deteriorated by microorganisms. After a period of 3 years both materials still promote microbial growth on the surface.

[Qualitative and quantitative examination of bacteria found in aquatic habitats. 2. Communication: application of miniturizid multitest systems for identification and biochemical typing of bacteria using a multi-point method (author's transl)]. / Qualitative und quantitative Bestimmung von Bakterienpopulationen aus aquatischen Biotopen. 2. Mitteilung: Anwendung miniaturisierter Systeme zur Identifizierung und Biotypisierung von Bakterien unter Verwendung der Vielpunktbeimpfungsmethode.

A large number of bacteria were characterized and identified using a miniturized multi-test system and an automatic inoculator. This testsystem is suitable for ecological studies to get information about the qualitative and quantitative composition of bacterial populations. More than that a biochemical typing of bacteria is possible.

[Behaviour of indicator bacteria in microbial slime on surfaces of walls in drinkingwater-reservoirs (author's transl)]. / Das Verhalten von Indikatorbakterien in mikrobiellen Schleimen von Wandflächen in Trinkwasserspeichern.

Slime formed by microbial activity on surfaces of a tightening compound (Silicon) and Epoxid-Coating in the sphere of drinking-water does not support survival of bacteria like E. coli, S. marcescens, P. aeruginosa, S. aureus and B. subtilis. The enterobacteriaeceae remained countable over a period of nine weeks, P. aeruginosa even eighteen weeks. Whereas the grampositive Bacteria died during the short time of one week. Autoclaved slime promoted the growth of the gramnegative bacteria.

[Trace metals in sewage sludge. Regional survey (author's transl)]. / Schwermetalle im Klärschlamm. Ein regionaler Uberblick.

A regional survey of sewage sludge compositions was conducted in the Rhein-Sieg-Kreis, including the city of Bonn. Sludge samples were obtained from 28 treatment plants. The following metals and metalloids have been measured by AAS: Fe, Zn, Cu, Cr, Ni, Pb, Cd, Hg, As, Se. The concentrations of some trace metals were extremely high, in particular the toxic element Cadmium. Sources of environmental pollutions can be revealed by analysing sludge constituents.