[Epidemiologic investigation of infection with Klebsiella using phage typing as a method]

In epidemiological investigations of infections with Klebsiella carried on by us for many years, a lysotyping method was used with a success. The results which are now being presented deal with 638 strains of Klebsiella pneumoniae and Klebsiella oxytoca originating from patients treated in hospitals in Wrocław, Kraków, Gdańsk and Sosnowiec during the years 1986-1992. Susceptibility of strains to the standard set of 14 phages used since ten years decreased significantly, when compared with previously typed strains of Klebsiella. Out of 312 susceptible strains of Klebsiella, majority (302) represented 47 phage types described previously. Sporadic appearance of new phage types was observed. Some phagotypes (37, 47, 112, 117, 119, 142, 153 and 157) were represented most frequently and concerned 55% of susceptible strains. High repeatability of phage types in consecutive groups of typed strains suggests a need for continuation of this method for typing Klebsiella. Decreased susceptibility of strains to standard set of phages requires introduction of new typing bacteriophages.