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Virulence factors from Aeromonas species
1Department of Biological Sciences, Rivers State University of Science and Technology, Port Harcourt, Nigeria.
Abstract:
Isolates (116) of Aeromonas were obtained from various sources and subjected to tests to establish their virulence factors. A high number of the isolates (69.8%) were found to be enterotoxigenic. The isolates from snails had more enterotoxigenic strains (73.3%), while those from cattle faeces had the lowest (33.3%). Haemolysin production was found to be high (60.3%) amongst the isolates, and human isolates gave the highest number of haemolysin producing strains (70.6%), while the least number (33.3%) was obtained from cattle strains. About 50% of the strains produced both enterotoxin and haemolysin. The enzyme profile of the isolates included amylase, lecithinase, lipase and protease. There was no definite pattern in the elaboration of these enzymes and the production of haemolysin and enterotoxin, thus inferring that the production of these factors is not specific to the source. Two isolates were seen to produce none of these enzymes, and one was positive for enterotoxin and haemolysin production, leaving only one isolate which yielded none of these factors. The work adds more support to the pathogenicity of Aeromonas species, and indicates the existence of non-pathogenic strains.
Insights
Aeromonas bacteria commonly possess virulence factors like enterotoxin and haemolysin. This study found many Aeromonas isolates were enterotoxigenic and produced haemolysin, indicating their pathogenic potential.
Area of Science:
- Microbiology
- Bacteriology
- Pathogen Identification
Background:
- Aeromonas species are ubiquitous in aquatic environments and can cause various infections in humans and animals.
- Understanding the virulence factors of Aeromonas is crucial for assessing its pathogenic potential and developing effective control strategies.
Purpose of the Study:
- To investigate the prevalence of virulence factors, specifically enterotoxin and haemolysin production, in Aeromonas isolates from diverse sources.
- To analyze the enzyme profiles of these isolates and their correlation with virulence factor production.
Main Methods:
- Isolation and identification of 116 Aeromonas strains from various sources.
- Phenotypic testing for enterotoxigenicity and haemolysin production.
- Enzyme profiling including amylase, lecithinase, lipase, and protease assays.
Main Results:
- High prevalence of enterotoxigenic (69.8%) and haemolysin-producing (60.3%) Aeromonas isolates.
- Isolates from snails showed higher enterotoxigenicity (73.3%), while human isolates had higher haemolysin production (70.6%).
- Approximately 50% of isolates produced both enterotoxin and haemolysin; enzyme production showed no specific pattern related to virulence factors or source.
Conclusions:
- Aeromonas species possess significant pathogenic potential due to the high prevalence of enterotoxin and haemolysin production.
- Virulence factor elaboration in Aeromonas is not strictly source-specific.
- The study identified both pathogenic and potentially non-pathogenic Aeromonas strains, highlighting the diversity within the species.