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Molecular profile and genetic diversity of cytolethal distending toxin (CDT)‐producing Escherichia coli isolates from diarrheal patients
Author(s) -
OLOOMI MANA,
BOUZARI SAEID
Publication year - 2008
Publication title -
apmis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.909
H-Index - 88
eISSN - 1600-0463
pISSN - 0903-4641
DOI - 10.1111/j.1600-0463.2008.00910.x
Subject(s) - pulsed field gel electrophoresis , biology , cytolethal distending toxin , escherichia coli , virulence , gene , microbiology and biotechnology , genetics , mobile genetic elements , genetic diversity , polymerase chain reaction , toxin , genetic analysis , horizontal gene transfer , genotype , plasmid , phylogenetic tree , population , demography , sociology
Cytolethal distending toxin (CDT)‐producing Escherichia coli strains areconsidered to be a heterogeneous group of E. coli . In the presentinvestigation, 20 CDT‐producing E. coli strains, which had already beenshown to be cytotoxic necrotizing factor ( cnf ) gene positive, wereselected by PCR. Since these strains proved to be CDT producers on CHO cells butwere partially characterized by PCR, they were subjected to PCR analysis toamplify the complete coding region of cdt genes. Moreover, the geneticrelatedness of these strains was examined by pulse field gel electrophoresis(PFGE). To check the extent of homogeneity of these strains at the chromosomallevel, tRNA insertion site analysis was performed. The CDT‐producing E.coli strains under investigation were shown to be heterogeneous and diverse in regard to their genetic analysis. This observed diversity could be an independent acquisition of virulence genes that might occur through horizontal gene transfer by mobile genetic elements. This conclusion is based on the fact that data shown by tRNA insertion site analysis revealed that there is no common pattern of insertion among these isolates although they do share a common trait of CDT production.