Related Experiment Videos
Virulence factors in Aeromonas spp and their association with gastrointestinal disease
G F Schiavano1, F Bruscolini, A Albano
1Institute of Toxicologic Hygienic and Environmental Science, University of Urbino, Italy.
Abstract:
Culture filtrates of eight Aeromonas strains isolated from the feces of 487 subjects (292 diarrhoeic patients and 195 asymptomatic subjects) were tested for toxin production in CHO and McCoy cells, and adhesion and invasive ability in Caco-2 cells. Among these isolates, three Aeromonas sobria and one Aeromonas caviae strains possessed virulence-associated properties. Toxin production was the most common of the three virulence properties. Two A. caviae were associated, in the absence of other diarrhoeagenic agents, with gastroenteritis; however, a virulence marker (cytotoxin) was recognized only in one strain. Two strains of A. sobria isolated from subjects with gastroenteritis were shown to be associated with one (cytotoxicity) or two (adhesion and invasive abilities) virulence factors, respectively. However, a third strain of A. sobria, although cytotoxic and invasive, was isolated from an asymptomatic subject. The results show that Aeromonas spp may act as human enteric pathogens, but also indicate that the significance of several putative virulence factors, such as production of cytotoxin and the capacity to adhere to and invade mammalian cells, remains controversial in explaining the enteropathogenesis of Aeromonads and therefore needs further studies.
Insights
Aeromonas bacteria can cause human gastroenteritis, but their virulence factors like toxin production and cell invasion require further study to confirm their role in enteropathogenesis.
Area of Science:
- Microbiology
- Infectious Diseases
- Gastroenterology
Background:
- Aeromonas species are increasingly recognized as potential human enteric pathogens.
- Understanding the virulence factors of Aeromonas is crucial for diagnosing and treating gastroenteritis.
Purpose of the Study:
- To investigate the virulence properties of Aeromonas strains isolated from human fecal samples.
- To assess the association between specific virulence factors and gastroenteritis in humans.
Main Methods:
- Eight Aeromonas strains from 487 fecal samples were analyzed.
- Toxin production was tested in CHO and McCoy cells.
- Adhesion and invasion abilities were evaluated in Caco-2 cells.
Main Results:
- Three Aeromonas sobria and one Aeromonas caviae strains exhibited virulence-associated properties.
- Toxin production was the most prevalent virulence factor observed.
- The association between specific virulence factors and gastroenteritis was inconsistent, with some pathogenic strains lacking clear markers and some asymptomatic isolates showing virulence traits.
Conclusions:
- Aeromonas species can act as human enteric pathogens.
- The role of virulence factors like cytotoxin production, adhesion, and invasion in Aeromonas enteropathogenesis remains controversial and warrants further investigation.