Aeromonas As A Human Pathogen

Abstract

Although the first Aeromonas strain was described by Zimmermann as early as in 1890, it took 60 years until Caselitz established human pathogenicity of strains then called "Vibrio jamaicensis". Since then, and especially in the last 10 years, there have been increasing numbers of reports on different infections caused by members of the genus Aeromonas. These include sepsis; meningitis; cellulitis; necrotizing fasciitis; ecthyma gangrenosum; pneumonia; peritonitis; conjunctivitis; corneal ulcer; endophthalmitis; osteomyelitis; suppurative arthritis; myositis; subphrenic abscess; liver abscess; cholecystitis and/or ascending cholangitis; urinary tract infection; endocarditis; ear, nose, and throat infections; balanitis; etc. The role of Aeromonas in gastrointestinal disease is very controversial. Increasing epidemiological data suggest that these organisms play a major role in enteric infections, but so far enteropathogenicity has not been demonstrable in experiments where volunteers were given high numbers of Aeromonas possessing different virulence factors. Virulence factors include hemolysin(s), enterotoxin(s), hemagglutinins, invasivity, and others; but these are not found more frequently in strains isolated from patients with diarrhea than from healthy controls. Whether there is a correlation between species and disease remains to be elucidated and requires more information about the taxonomy of this genus.

Case Reports: Fatal Necrotizing Fasciitis Caused by Aeromonas sobria in Two Diabetic Patients

“…Aeromonas species can produce many virulence factors, including hemolysin, cytotoxin, aerolysin, enterotoxin, endotoxin, protease, adhesins, leukocidin, and lipases [1,11,14,20,23,29,30]. Aeromonas hydrophila is the most commonly reported pathogen that causes Aeromonas necrotizing fasciitis and septicemia; these conditions often occur after soft tissue trauma with exposure to contaminated water or nonfecal organic materials and produce skin lesions similar to those observed in infections caused by Vibrio species [7,19,21,24,26,28].…”

“…Infections resulting from Aeromonas sobria most commonly present as gastroenteritis and diarrhea [1,14,15,23]. Aeromonas sobria was reported to account for 25% to 27% of extraintestinal aeromonas infections [15,28].…”

Distribution ofAeromonasphenospecies and genospecies among strains isolated from water, foods or from human clinical samples

“…In studies on the aetiology of human diarrhoea in developed countries Aeromonas spp. have been isolated in 1-3 % of faecal samples collected from patients [10,11]. Drinking water and food are the suspected vehicles (1,6,12].…”

Characterisation of haemolytic activity fromAeromonas caviae

“…There is increasing evidence that the enteropathogen Aeromonas caviae is a causative agent of gastroenteritis [1][2][3][4][5][6] and is a predominant isolate among the microbiota of diarrhoeal stool specimens of infants, from intestinal and extraintestinal infections, and from aquatic ecosystems [4,[7][8][9][10]. The regulation and expression of putative microbial virulence factors by the environment and cytoadherence to host cells are essential events in the establishment of pathogenicity.…”