Related Experiment Videos
Enterotoxicity of clinical and environmental isolates of Aeromonas spp
1Department of Microbiology, Banaras Hindu University, Varanasi, India.
Abstract:
Of 147 isolates of three species of Aeromonas, 54 were from clinical and 93 from environmental sources. When tested for enterotoxin production, most of the isolates (56%) caused accumulation of fluid in rabbit ileal loops (RILs). Although large proportions of clinical and environmental isolates of A. caviae (55% and 65%, respectively) elicited such a response in RILs, isolates of A. hydrophila and A. sobria produced significantly more fluid (p less than 0.05). Furthermore, the environmental strains of A. hydrophila and A. sobria produced more fluid than the clinical isolates (p less than 0.05). The strains of Aeromonas spp. that caused little or no fluid accumulation in the initial experiments became enterotoxin producers after 1-3 passages through RILs, regardless of their source, and showed gradual enhancement of fluid outpouring after each passage. The present study suggests that all strains of these species of Aeromonas are potentially enterotoxigenic, whether from clinical or environmental sources.
Insights
All Aeromonas species, whether from clinical or environmental sources, have the potential to produce enterotoxins. This study found that most isolates caused fluid accumulation in rabbit ileal loops (RILs), with some species showing enhanced production after passages.
Area of Science:
- Microbiology
- Bacteriology
- Public Health
Background:
- Aeromonas species are increasingly recognized as opportunistic pathogens.
- Understanding the enterotoxigenic potential of Aeromonas is crucial for public health.
- Both clinical and environmental isolates warrant investigation for toxin production.
Purpose of the Study:
- To assess the enterotoxin production capabilities of clinical and environmental Aeromonas isolates.
- To compare the enterotoxigenic potential among different Aeromonas species (A. caviae, A. hydrophila, A. sobria).
- To investigate the influence of rabbit ileal loop (RIL) passages on Aeromonas enterotoxin production.
Main Methods:
- Isolation and identification of 147 Aeromonas strains from clinical and environmental sources.
- In vitro enterotoxin testing using the rabbit ileal loop (RIL) assay.
- Statistical analysis to compare fluid accumulation among species and sources.
- Serial passages of isolates through RILs to evaluate changes in enterotoxin production.
Main Results:
- 56% of all Aeromonas isolates demonstrated enterotoxigenicity via RIL assay.
- A. hydrophila and A. sobria isolates produced significantly more fluid than A. caviae isolates (p < 0.05).
- Environmental A. hydrophila and A. sobria strains showed higher fluid production than their clinical counterparts (p < 0.05).
- Aeromonas strains lacking initial enterotoxigenicity became potent producers after 1-3 RIL passages, with enhanced fluid outpouring.
Conclusions:
- All tested Aeromonas species (A. caviae, A. hydrophila, A. sobria) are potentially enterotoxigenic.
- Both clinical and environmental Aeromonas strains pose a potential risk due to their enterotoxin production.
- The RIL model suggests that Aeromonas enterotoxin production can be induced or enhanced through host passage.