Virulent strains of Salmonella enteritidis disrupt the epithelial barrier of Caco-2 and HEp-2 cells
- PDF / 183,953 Bytes
- 6 Pages / 595 x 785 pts Page_size
- 17 Downloads / 160 Views
O R I G I N A L PA P E R
Cristina Solano · Begoña Sesma · Miguel Alvarez · Elena Urdaneta · David Garcia-Ros · Alfonso Calvo · Carlos Gamazo
Virulent strains of Salmonella enteritidis disrupt the epithelial barrier of Caco-2 and HEp-2 cells Received: 18 May 2000 / Revised: 21 September 2000 / Accepted: 23 October 2000 / Published online: 9 December 2000 © Springer-Verlag 2000
Abstract To confirm the existence in nature of Salmonella enteritidis strains of different degrees of virulence and to elucidate the mechanisms underlying the effects of such strains on the epithelial barrier function, the consequences of infection of Caco-2 cells and HEp-2 cells with 15 S. enteritidis strains in a chicken infection model were examined. The more virulent strains of S. enteritidis, which are biofilm producers in adherence test medium, were able to disrupt HEp-2 and Caco-2 monolayers, as shown by transmonolayer electrical resistance and lactate dehydrogenase activity. In contrast, the low-virulence strains of S. enteritidis, which do not produce biofilms in adherence test medium, had no effect on the same cells. An avirulent rough mutant of Salmonella minnesota exhibited a pattern of behaviour similar to that of the low virulence strains of S. enteritidis, whilst a clinical Salmonella typhi strain caused rapid injury to the monolayers. The effect of supernatants of Salmonella cultures in adherence test medium on the integrity of Caco-2 cell monolayers indicated that the high-virulence S. enteritidis strains, but not the low-virulence strains, release a soluble factor when incubated under optimum biofilm-forming conditions, which enables the disruption of the integrity of Caco-2 monolayers.
C. Solano · C. Gamazo (✉) Departamento de Microbiología, Universidad de Navarra, Apartado 117, 31080 Pamplona, Spain e-mail: [email protected], Fax: +34-94-8425649 B. Sesma Instituto de Salud Pública de Navarra, 31004 Pamplona, Spain M. Alvarez Laboratorio Municipal, 31001 Pamplona, Spain E. Urdaneta Departamento de Fisiología y Nutrición, Universidad de Navarra, 31080 Pamplona, Spain D. Garcia-Ros · A. Calvo Departamento de Anatomía Patológica, Universidad de Navarra, 31080 Pamplona, Spain
Keywords Salmonella · Biofilm · HEp-2 · Caco-2 · Virulence
Introduction The pathogenicity of Salmonella enteritidis is thought to be partly due to its ability to invade the host epithelium during infection. This process of intestinal invasion can be mimicked in vitro by infecting tissue culture cells of epithelial origin (Rosenshine et al. 1994). Although the study of cultured epithelial cells has been useful in defining some of the events that occur during Salmonella infection, additional knowledge has been obtained from the study of infected polarized epithelial monolayers, in particular Caco-2 cells (Finlay et al. 1988; Francis et al. 1991). These monolayers have defined apical and basolateral surfaces, well-developed brush borders and functional tight junctions. Thus, they represent a model that more closely resembles the intestinal barrier than cultu
Data Loading...
