| Popis: |
Interaction of Yersinia enterocolitica (Y.e.) and HeLa cells was tested with 102 epidemiologically defined strains of various sources. Strains causing a penetration fell into either of two groups, i.e. causing an infection of > 75%, or infecting only 2 to 11% of HeLa cells. The first group was represented by members of serogroups 3 and 9 which are the most important agents of human yersiniosis in Germany. Single cultures each of 0:7,13 (isolated from river water), 0: 1,2a,3 and 0:4,32 (reference strains of the culture collection of Institut Pasteur) were characterized by a similar infectivity. — Infection rates of 2 to 11% were irregularly observed in strains of O-groups 5; 6,30; 6,31; 7,8; 7,13; 16; and “not typable”; the majority of strains of these serogroups, however, gave negative results as well as representatives of O-groups 4,33; 5,27; 10; and 11,23 ( ). Examination of a limited number of formalin-killed suspensions gave the same reactions as living bacteria of the corresponding strains, but heating at 100 °C destroyed the ability to interact ( ). It is concluded from these observations that heat-labile surface components might be essential for penetration of Y. e. into HeLa cells. The interaction of HeLa cells with living or killed bacteria does not reflect the situation in vivo, but it could be indicative of the presence of one of the virulence factors which collectively constitute pathogenicity. On the premises that only a high degree of infectivity (> 75% of tissue cells infected) is considered significative the strains of Y. e. examined in the present study show an acceptable correlation between HeLa cell interaction and known bacteriological and epidemiological facts. |
