English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

RDEC-1, an Escherichia coli strain that adheres to rabbit mucosa and causes an attaching, effacing lesion, expresses the pilus adhesin AF/R1 which determines in vitro attachment to rabbit intestinal brush borders. In order to determine the role of AF/R1 pili in the pathogenesis of enteropathogenic diarrhea in rabbits, we localized the genes for AF/R1 expression, constructed an AF/R1- strain, and compared the virulence of the AF/R1+ and AF/R1- strains with particular attention to the development of attaching, effacing lesions. We introduced Tn5 into the 86-megadalton (MDa) conjugative plasmid known to mediate expression of AF/R1 pili and transferred the derivative plasmids into laboratory strain HB101. Transconjugant M5 was found to contain the 86-MDa plasmid from RDEC-1 and to express AF/R1 pili. Pilus expression on M5 was confirmed by reaction with antiserum raised against purified AF/R1 pili and allowed the bacteria to adhere to the rabbit ileum in an in vitro assay. Three Tn5 insertions in the 86-MDa plasmid were obtained which resulted in loss of AF/R1 expression. Part of the plasmid was mapped, including a region necessary for AF/R1 pilus expression. AF/R1- mutant strain M34 was constructed, and its pathogenesis was investigated. M34 produced disease in rabbits but was less virulent than the parent. The characteristic effacing lesions of RDEC-1 and enteropathogenic E. coli developed in the intestine of rabbits infected with either M34 or RDEC-1, although with M34 they were much less frequent and did not involve the small bowel. We conclude that AF/R1 pilus expression is not essential for the attaching, effacing lesion but serves as an accessory virulence factor which promotes an initial interaction of RDEC-1 with normal epithelial cells.

infection and immunity

Characterization of the plasmid from Escherichia coli RDEC-1 that mediates expression of adhesin AF/R1 and evidence that AF/R1 pili promote but are not essential for enteropathogenic disease