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Abstract:
The number of reports on the isolation of Aeromonas from patients with diarrhoeal disease is now large and suggests an etiological role of the bacterium. It is well established that strains of Aeromonas produce an enterotoxin. This enterotoxin is cytotonic, i.e. it does not damage the membrane, and it does not cross-react immunologically with cholera toxin and Escherichia coli heat-labile (LT) toxin. Most enterotoxigenic strains also produce a cytotoxic protein (hemolysin), the role of which is probably limited in diarrhoea but potentially toxic in humans in other kinds of infections. Strains of Plesiomonas shigelloides also seem to be able to cause diarrhoea in some cases. The pathogenesis of Plesiomonas-induced diarrhoea remains to be elucidated, but a heat-stable enterotoxin may be involved.
Insights
Aeromonas bacteria are increasingly linked to diarrheal disease, producing a cytotonic enterotoxin distinct from cholera toxin. Some strains also produce hemolysin, potentially toxic in other infections.
Area of Science:
- Microbiology
- Infectious Diseases
- Gastroenterology
Background:
- Growing reports link Aeromonas isolation to diarrheal disease, suggesting a significant etiological role.
- Aeromonas strains are known to produce an enterotoxin that is cytotonic, not damaging cell membranes.
- This enterotoxin does not show cross-reactivity with cholera toxin or Escherichia coli heat-labile (LT) toxin.
Purpose of the Study:
- To elucidate the role of Aeromonas and Plesiomonas shigelloides in diarrheal diseases.
- To characterize the enterotoxins produced by these bacteria.
- To understand the potential toxic mechanisms beyond diarrhea.
Main Methods:
- Review of existing reports on Aeromonas and Plesiomonas shigelloides isolation in diarrheal patients.
- Characterization of Aeromonas enterotoxin properties (cytotonic, non-cross-reactive with LT toxin).
- Investigation of cytotoxic protein (hemolysin) production by enterotoxigenic Aeromonas strains.
Main Results:
- Aeromonas enterotoxin is cytotonic and immunologically distinct from cholera toxin and E. coli LT toxin.
- Most enterotoxigenic Aeromonas strains also produce a cytotoxic hemolysin.
- Plesiomonas shigelloides may cause diarrhea, potentially via a heat-stable enterotoxin, though its pathogenesis requires further study.
Conclusions:
- Aeromonas is a significant cause of diarrheal disease, with its enterotoxin and hemolysin playing potential roles.
- The specific mechanisms of Plesiomonas-induced diarrhea are not fully understood but may involve a heat-stable enterotoxin.
- Further research is needed to fully elucidate the pathogenesis of Plesiomonas-associated diarrhea.