Colonization Factors of Enterotoxigenic Escherichia coli Isolated from Children in North India

Sommerfelt, Halvor; Steinsland, Hans; Grewal, Harleen M. S.; Viboud, Gloria I.; Bhandari, Nita; Gaastra, Wim; Svennerholm, Ann‐Mari; Bhan, Maharaj Kishan

doi:10.1093/infdis/174.4.768

Cited by 58 publications

(60 citation statements)

References 52 publications

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“…Even if they did not belong to the same cluster, it seems likely that they were clonally closely related and probably belonged to the same clonal group. CFA/I-positive strains isolated in different geographical areas also are often closely related (14,16,21). In this study, we found that CFA/I-positive strains isolated from children in India (21) clustered together with our West African CFA/I-positive strains.…”

Section: Discussionmentioning

confidence: 51%

“…Serotyping is a commonly used method for indicating clonal relatedness between bacteria, including ETEC. Although there are indications that ETEC strains that share the same serotype often are clonally closely related (14,15,16,21), it seems likely that clonally related strains may also have different serotypes, similar to what has been found for Shigella strains (19).…”

Section: Discussionmentioning

confidence: 74%

“…Earlier fingerprint analyses showed that ETEC strains sharing the same toxin-CF profile are often clonally closely related, even when the strains are isolated in different geographical areas (14,15,16,21). These data indicate that some ETEC strains belong to widespread clonal groups, where a clonal group is defined to comprise all of the descendants of the ancestral strain the first possessed their shared virulence genes.…”

Section: Discussionmentioning

confidence: 97%

“…We also included 28 ETEC strains collected in India, comprising 11 that were positive for STh, colonization antigen I (CFA/I), and coli surface antigen 21 (CS21); 3 that were positive for STh, LT, and CFA/I; and 14 that were positive for LT and CS17 (21,23). All 8,590 strains were subjected to rep-PCR and included in the fingerprint comparisons to increase the likelihood of identifying closely matching fingerprint patterns for each of the ETEC strains.…”

Section: Methodsmentioning

confidence: 99%

“…However, Steinsland et al previously found that natural ETEC infections protect young children against new infections with ETEC strains that have the same toxin-CF profile but that the CFs do not seem to contribute measurably to this protection (22). Earlier studies showed that ETEC strains that have the same toxin-CF profile are often clonally closely related (14,15,16,21).…”

mentioning

confidence: 99%

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Clonal Relatedness of Enterotoxigenic Escherichia coli Strains Isolated from a Cohort of Young Children in Guinea-Bissau

et al. 2004

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In a cohort study of 200 young children in Guinea-Bissau, it was previously found that some enterotoxigenic Escherichia coli (ETEC) strains were more pathogenic than others, depending on the type of toxin that they could produce, and that natural ETEC infections induced substantial protection against new infections with ETEC strains that had the same combination of toxins and colonization factors (CFs). We wanted to describe the clonal relatedness of the ETEC strains isolated during this study and to investigate whether the protective antigens and the virulence factors that were responsible for the pathogenic traits were common to strains that were clonally closely related or whether they were more likely to be encoded by the ETEC virulence plasmids that normally encode the toxins and the CFs. By performing repetitive sequence-based PCR analysis of strains representing 452 infections, we found that strains that had the same toxin-CF profile were usually closely related, although a few were unrelated. Strains that did not have the same toxin-CF profiles but that were positive for a given toxin or for a given CF were not consistently more closely related to each other than to strains that were negative for the same toxin or CF. Our results indicate that the pathogenic traits of ETEC were mainly attributed to genes carried on the ETEC virulence plasmids. Because most strains that had the same toxin-CF profile were closely related, it seems likely that the toxin-CF-specific protection was clonal and was not targeting antigens encoded by the virulence plasmids. These results are of relevance to the ETEC vaccine development effort.

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Section: Discussionmentioning

confidence: 51%