Molecular characterization of enteroinvasive Escherichia coli ipa genes by PCR-RFLP analysis

Abstract

In this study, polymorphism in ipa genes was found in five out of nine EIEC serotypes studied. When SalI and HindII were used in RFLP-PCR assays many EIEC serotypes showed polymorphism in ipaB and ipaD. On the other hand, no polymorphism was observed in ipaA and ipaC in these strains. The polymorphism present in EIEC strains is serotype-dependent, since restriction patterns were conserved amongst strains belonging to the same serotype. When IpaB deduced amino acid sequences of S. flexneri M90T and FBC124-13 were compared, ten amino acids changes could be observed mainly in the amino-terminal region. The deduced EIEC IpaD amino-acid sequence presented 91% similarity with the Shigella strain. In this case, amino acid changes were spread out through the whole structure, except in the carboxyl-terminal region.

Diarrheagenic Escherichia coli

“…However, the data reveal that there are no changes in genes of the invasion plasmid antigens that could explain the differences in pathogenicity between Shigella and EIEC 400 . Moreover, recent studies from our group showed that the genes responsible for cell spreading ( icsA and icsB ) and regulation of the immune response of the host ( osp ) did not indicate changes that could explain the difference in pathogenicity between Shigella and EIEC (data not shown).…”

“…The complex process in colonization and EIEC survival in the gastrointestinal barrier depends on the presence of a large plasmid of about 220 kb ( pInv ), very similar to that found in Shigella 397, 398, 399, 400. In this process, multiple bacterial genes are involved, both chromosomal and plasmidial.…”

Expression of bacterial virulence factors and cytokines during in vitro macrophage infection by enteroinvasive Escherichia coli and Shigella flexneri: a comparative study

“…4). EIEC shares almost complete identity of the ipaC nucleotide sequence with S. flexneri (Gibotti et al 2004), suggesting that an EIEC chromosomal factor(s) could modulate ipaC transcription inside macrophages. However, further studies are necessary to investigate this hypothesis.…”

“…EIEC strain FBC124-13, serotype O124:H -, was isolated from diarrheic faeces and was Sereny testpositive (Gibotti et al 2004). Bacteria were grown at 37ºC for two days on trypticase soy agar plates containing 0.02% Congo Red.…”

Recognition of enteroinvasive Escherichia coli and Shigella flexneri by dendritic cells: distinct dendritic cell activation states

“…However, the disease induced by EIEC is generally less severe than that induced by Shigella spp (Dupont et al 1971, 1989. This difference in severity may be associated with a lower level of expression of virulence factors by EIEC in the presence of various host cells, such as macrophages and intestinal epithelial cells (Gibotti et al 2004, Moreno et al 2009, Bando et al 2010.…”