A case report: Aeromonas sobria gastroenteritis in an adult

Aeromonas sobria, a member of the Aeromonas hydrophila group, recently has been recognized as a gastrointestinal pathogen in adults. There have been a few documented cases, and these have come from far eastern countries, namely India, Thailand, and Indonesia. The authors have isolated a strain of A. sobria from a 62-year-old male patient suffering from diarrheal disease. He had no history of travel outside of the United States for several decades. He presented with a severe diarrheal disease that closely mimicked cholera, producing large quantities of green "rice water" stool. He was severely dehydrated and was in electrolyte imbalance. No other enteric pathogen could be detected. The organism presumptively was identified as Vibrio cholera (81.5% probability) by the Micro Scan system, but later was identified definitively as A. sobria using the API 20E and ZYM systems. Cell-free extract of this strain contained hemolysins, proteolytic enzymes, and enterotoxin. The strain closely fits the description of Burke and associates (J Clin Microbiol 1982; 15:48-52) for their group A, type 1 (VP positive, arabinose negative, enterotoxin producer). The patient was treated with tetracycline and recovered.