Color enhanced scanning electron micrograph (SEM) of shiga toxin producing Escherichia coli (STEC), O103. This belongs to the third most frequently isolated enterohemorrhagic E. coli (EHEC) serotypes in Germany following isolates of O157 and O26. The most common non-O157:H7 serotypes associated with human disease include: O26, O103, O111, and O113. At least 10 of outbreaks caused by these organisms have been reported in the USA, Japan, Germany, Italy, Australia, and the Czech Republic. For most of the outbreaks, the source of infection could not be determined. In some countries such as Chile, Argentina, and Australia, non-O157:H7 serotypes have been found to be responsible for the majority of hemolytic uremic syndrome (HUS) cases. Non-bloody diarrhea has also been associated with some of these non-O157:H7 serotypes. Image width: 12.8 micrometers. Magnification: 7,810x printed 10 cm wide.