Development of an in vitro model for study of non-O1 Vibrio cholerae virulence using Caco-2 cells.
Non-O1 Vibrio cholerae strains have been reported as a causative agent of diarrhea throughout the world. We recently reported that non-O1 V. cholerae strains cause diarrhea in human volunteers. In this study we evaluated the virulence of three strains of non-O1 V. cholerae in a Caco-2 cell adherence assay by light and electron microscopy. A-5 is an environmental isolate which failed to colonized volunteers and did not cause diarrhea. It exhibited low numbers of organisms adherent to Caco-2 cells, leaving the microvilli intact. Strain 2076-79, isolated from a patient with diarrhea, colonized human volunteers without producing disease. It adhered to Caco-2 cells in moderate numbers without producing any damage to the microvilli. Strain NRT36S, a clinical isolate, colonized human volunteers and produced significant diarrhea disease. This strain adhered in very large numbers to Caco-2 cells and caused damage to the brush borders. Membrane-bound bacteria were also seen within the cytoplasm of these cells. Scanning electron microscopy confirmed the generalized adherence of NRT36S to the microvilli of Caco-2 cells. The three strains did not appear to compete with each other for binding sites on Caco-2 cells and were not adherent when assays were conducted at 4 degrees C. Our results with strains A-5, 2076-79, and NRT36S correlate well with observations in human volunteer studies, suggesting that Caco-2 cells provide an appropriate in vitro system for further investigation of the pathogenesis of non-O1 V. cholerae gastroenteritis.
Panigrahi
P
P
Department of Pathology, University of Maryland School of Medicine, Baltimore 21201.
Tall
B D
BD
Russell
R G
RG
Detolla
L J
LJ
Morris
J G
JG
D000704:Analysis of Variance; D001422:Bacterial Adhesion; D005455:Fluorescent Antibody Technique; D005759:Gastroenteritis / Q000382:microbiology; D006801:Humans; D008954:Models, Biological; D014407:Tumor Cells, Cultured; D014735:Vibrio Infections / Q000382:microbiology; D014734:Vibrio cholerae / Q000302:isolation & purification / Q000472:pathogenicity* / Q000648:ultrastructure; D014774:Virulence