[Microbial contamination of water by pipe and tubing material. 2. Growth of Legionella pneumophila].

In the 1st communication it was possible to show that some hoses and insufficiently cleaned high grade steel pipe can produce a microbial growth. The growth-promoting effect of materials in the water distribution system for Legionella pneumophila has been discussed before. In this investigation it was tested how L. pneumophila behaves in pipes and hoses with narrow diameter, at temperatures from 35 degrees C to 40 degrees C and over a time of half a year. L. pneumophila could be found in high numbers in the water from PVC, PE, PTFE, rubber and silicon hoses all over the time and regularly in low numbers or occasionally in glass, high-grade steel pipes and PA hose. L. pneumophila could be found only for the first 4 weeks in the copper pipe.