Comparison of ozone inactivation, in flowing water, of hepatitis A virus, poliovirus 1, and indicator organisms.

In steadily flowing water at 20 degrees C and pH 7, five organisms had the following order of resistance to ozone (at constant levels of ozone): poliovirus 1 (PV1) less than Escherichia coli less than hepatitis A virus (HAV) less than Legionella pneumophila serogroup 6 less than Bacillus subtilis spores. The tests were repeated at 10 degrees C with HAV, PV1, and E. coli. Ozone inactivation of HAV and E. coli was faster at 10 degrees C than at 20 degrees C. At 20 degrees C, 0.25 to 0.38 mg of O3 per liter was required for complete inactivation of HAV but only 0.13 mg of O3 per liter was required for complete inactivation of PV1

Pseudomonas aeruginosa cross-colonization and persistence in patients with cystic fibrosis. Use of a DNA probe.

To investigate cross-colonization with and persistence of Pseudomonas aeruginosa in cystic fibrosis (CF), 181 isolates from 76 CF patients were typed using a P. aeruginosa-specific DNA probe. Whereas sibling pairs predominantly harboured genotypically identical P. aeruginosa strains, all of the other patients harboured different strains. Seventy-nine per cent (22/31) of the infected CF patients harboured the same strains at the beginning and the end of a summer camp. A change of strains was seen in 10% (3/31) of the patients at the end of the camp. Forty-six per cent (6/13) of the patients who were apparently initially uninfected, acquired P. aeruginosa by the end of the period. Genotyping proved that strain change or acquisition was due to cross-colonization in four of nine cases. Very little P. aeruginosa was isolated from the inanimate environment. Persistence of P. aeruginosa after a temporary loss due to antibiotic therapy was seen in 12/16 paired patient strains before and after antibiotic therapy. Thus, suppression followed a flare-up seemed to occur in these patients rather than eradication and a new infection. When 35 patients were followed over a period of 6 months, 7 (20%) changed the strain in their sputum. Only one of 43 patients harboured two different P. aeruginosa strains simultaneously over a long period

Mikrobiologische und virologische Untersuchungen zur Eignung des Enterobakteriennachweises als Qualitaetskriterium fuer Trinkwasser Schlussbericht

With 68 refs., 11 tabs., 27 figs.TIB: FR 3237 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman