Virulence factors in Aeromonas spp and their association with gastrointestinal disease.
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.
Schiavano
G F
GF
Institute of Toxicologic Hygienic and Environmental Science, University of Urbino, Italy.
Bruscolini
F
F
Albano
A
A
Brandi
G
G
D000333:Aeromonas / Q000302:isolation & purification / Q000472:pathogenicity*; D000818:Animals; D001422:Bacterial Adhesion; D001427:Bacterial Toxins / Q000096:biosynthesis; D016466:CHO Cells; D018938:Caco-2 Cells; D006224:Cricetinae; D003603:Cytotoxins / Q000096:biosynthesis; D003967:Diarrhea / Q000382:microbiology*; D005243:Feces / Q000382:microbiology*; D005759:Gastroenteritis / Q000382:microbiology*; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology*; D006801:Humans; D008856:Microscopy, Fluorescence; D014774:Virulence
D001427:Bacterial Toxins; D003603:Cytotoxins