Otitis Media Caused by O100: A Case Report and Review of the Literature.

Infections due to are rarely documented in Israel. Here we report a case of recurrent otitis media in a young male, caused by non-O1/O139. This extra-intestinal infection was caused by O100 and has been associated with freshwater exposure and travel. Symptoms of chronic periodic earaches along with purulent exudate began about one week after the patient suffered a water skiing accident on a river in Australia. The condition lasted for three years, until his ear exudate was examined in a clinical laboratory, diagnosed and treated. Five bacterial isolates were identified as O100. The isolates were screened for genetic characteristics and were found positive for the presence of , , and virulence genes. All isolates were negative for the presence of . Based on antibiogram susceptibility testing, ciprofloxacin ear drops were used until the patient's symptoms disappeared. This case demonstrates that exposure to freshwater can cause otitis media by non-O1/O139 in young and otherwise healthy humans.