A rare case of severe gastroenteritis caused by Aeromonas hydrophila after colectomy in a patient with anti-Hu syndrome: a case report

BACKGROUND: Aeromonas hydrophila is a gram-negative facultative anaerobic coccobacillus, which is an environmental opportunistic pathogen. A. hydrophila are involved in several infectious diseases such as gastroenteritis, septicemia and wound infections. However, gastroenteritis caused by Aeromonas spp. are rare and the clinical relevance of Aeromonas species in stool specimens is still under debate. CASE PRESENTATION: Our case concerns a 32-year-old woman who presented at hospital with a worsening watery diarrhea and fever requiring intensive care. A cholera-like illness was diagnosed. The patient had a past history of an anti-Hu syndrome with a myenteric ganglionitis. A molecular multiplex RT-PCR (QIAstat-Dx Gastrointestinal Panel, QIAGEN) covering a broad spectrum of diverse gastrointestinal pathogens performed directly from the stool was negative but the stool culture revealed growth of A. hydrophila. Further investigations of the A. hydrophila strain in cell cultures revealed the presence of a cytotoxic enterotoxin. CONCLUSIONS: Although A. hydrophila rarely causes gastroenteritis, Aeromonas spp. should be considered as a causative agent of severe gastroenteritis with a cholera-like presentation. This case highlights the need to perform culture methods from stool samples when PCR-based methods are negative and gastrointestinal infection is suspected.