SHIGA TOXIN-PRODUCING ESCHERICHIA-COLI INFECTIONS IN GERMANY

A prospective study was carried out in collaboration with two children 's hospitals in Wurzburg, Germany to assess the incidence and clinical manifestations of infections due to Shiga toxin-producing Escherichia coli (STEC) in children. Between 1991 and 1995, stool samples from 27 88 children with enteritis were investigated for the occurrence of STE C. STEC cultures from stools were screened using PCR with primers comp lementary to Shiga toxin 1 (Stx1) and Shiga toxin 2 (Stx2) genes. PCR- positive samples were further subjected to colony blot hybridization a nd probe positive colonies were serotyped and analyzed for the presenc e of virulence genes. There was an increase in the incidence of STEC i nfections from 0.4% in 1991 to 2.8% in 1994. In 1995 the number of inf ections remained nearly unchanged (2.5%). Infection with STEC was asso ciated with painful nonbloody diarrhea in most patients. Among the 35 patients in this study with stools containing STEC, only 9 (25.7%) had O157 colonies of which 3 (8.6%) were O157:H7 and 6 (17.1%) were sorbi tol-fermenting O157:H-. In an additional study in 1994/1995, STEC etio logy in 88 patients with HUS from Germany was confirmed in our laborat ories by culture of STEC from stools, and in 20 additional HUS cases b y serological analysis. Of the strains from stools of HUS patients, 78 % belonged to serogroup O157. The most frequently isolated non-O157 se rogroups were O26 and O111. These results demonstrate that when analyz ing stools of patients with bloody diarrhea, HUS, or painful nonbloody diarrhea, the occurrence of non-O157:H7 strains should be considered when classical microbiological analysis fails to yield a standard ente ric pathogen, such as Campylobacter; E. call O157:H7, Salmonella, Shig ella, or Yersinia.