Identification and characterization of CS20, a new putative colonization factor of enterotoxigenic Escherichia coli.

摘要: An enterotoxigenic Escherichia coli (ETEC) strain producing a previously undescribed putative colonization factor was isolated from child with diarrhea in India. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of bacterial heat extracts revealed polypeptide band 20.8 kDa when the bacteria were grown at 37 degrees C which absent after growth 22 C. A specific rabbit antiserum raised against purified 20.8-kDa protein bound specifically to fimbriae, as shown by immunoelectron microscopy, and inhibited adhesion tissue-cultured Caco-2 cells. Transformation recombinant plasmid harboring cfaD gene, encodes positive regulator for several ETEC induced hyperexpression fimbrial subunit substantial increase proportion cells that fimbriated. The N-terminal amino acid sequence showed 65 60% identity PCFO20 987P fimbriae human porcine ETEC, respectively. We propose term CS20 this new ETEC.