Aeromonas hydrophilaRANK: Species
TAXONOMY: Bacteria -> Proteobacteria -> Gammaproteobacteria -> Aeromonadales -> Aeromonadaceae -> Aeromonas -> Aeromonas hydrophila
Aeromonas hydrophila is a heterotrophic, Gram-negative, rod-shaped bacterium mainly found in areas with a warm climate. This bacterium can be found in fresh or brackish water. It can survive in aerobic and anaerobic environments, and can digest materials such as gelatin and hemoglobin. A. hydrophila was isolated from humans and animals in the 1950s. It is the most well known of the species of Aeromonas. It is resistant to most common antibiotics and cold temperatures. Because of its structure, it is very toxic to many organisms. When it enters the body of its victim, it travels through the bloodstream to the first available organ. It produces aerolysin cytotoxic enterotoxin that can cause tissue damage. A. hydrophila, A. caviae, and A. sobria are all considered to be opportunistic pathogens, meaning they rarely infect healthy individuals. A. hydrophila is widely considered a major fish and amphibian pathogen,[ and its pathogenicity in humans has been recognized for decades. The genomic insights of aeromonads could be a stepping stone into understanding of them.A. hydrophila is not as pathogenic to humans as it is to fish and amphibians. One of the diseases it can cause in humans, gastroenteritis, occurs mostly in young children and people who have compromised immune systems or growth problems. This bacterium is linked to two types of gastroenteritis. The first type is a disease similar to cholera, which causes rice-water diarrhea. The other type is dysenteric gastroenteritis, which causes loose stools filled with blood and mucus. Dysenteric gastroenteritis is the most severe out of the two types, and can last for several weeks. A. hydrophila is also associated with cellulitis. It also causes diseases such as myonecrosis and eczema in people with compromised or suppressed (by medication) immune systems. In very rare cases, A. hydrophila can cause necrotizing fasciitis.
This species has been identified as a resident in the human gastrointestinal tract based on the phylogenetic framework of its small subunit ribosomal RNA gene sequences.[PMC 4262072]