Aeromonas

Taxobox
color = lightgrey
name = Aeromonas
regnum = Bacteria
phylum = Proteobacteria
classis = Delta Proteobacteria
ordo = Aeromonadales
familia = Aeromonadaceae
genus = "Aeromonas"
genus_authority = Stanier 1943
type_strain = "Aeromonas hydrophila"
subdivision_ranks = Species
subdivision = "A. allosaccharophila "
"A. bestiarum"
"A. bivalvium"
"A. encheleia"
"A. enteropelogenes"
"A. euchrenophila"
"A. hydrophila"
"A. ichthiosmia"
"A. jandaei"
"A. media"
"A. molluscorum"
"A. popoffii"
"A. punctata"
"A. salmonicida"
"A. schubertii"
"A. sharmana"
"A. simiae"
"A. sobria"
"A. veronii"

"Aeromonas" is a gram-negative, facultative anaerobic rod that morphologically resembles members of the family Enterobacteriaceae. Fourteen species of "Aeromonas" have been described, most of which have been associated with human diseases. The most important pathogens are "A. hydrophila", "A. caviae", and "A. veronii" biovar sobria. The organisms are ubiquitous in fresh and brackish water.

Two major diseases associated with "Aeromonas" are gastroenteritis and wound infections, with or without bacteremia. Gastroenteritis typically occurs after the ingestion of contaminated water or food, whereas wound infections result from exposure to contaminated water.

Although some potential virulence factors (e.g. endotoxins, hemolysins, enterotoxins, adherence factors) have been identified, their precise role is unknown. "Aeromonas" species cause: 1) opportunistic systemic disease in immunocompromised patients, 2) diarrheal disease in otherwise healthy individuals, and 3) wound infections.

Gastroenteritis

Gastrointestinal disease in children is usually an acute, severe illness, whereas that in adults tends to be chronic diarrhea. Severe "Aeromonas" gastroenteritis resembles shigellosis, with blood and leukocytes in the stool. Acute diarrheal disease is self limited, and only supportive care is indicated in affected patients.

Antimicrobial Therapy

Is necessary for patients with chronic diarrheal disease or systemic infection. "Aeromonas" species are resistant to penicillins, most cephalosporins, and erythromycin. Ciprofloxacin is consistently active against their strains in the U.S. and Europe, but resistant cases have been reported in Asia.