Please use this identifier to cite or link to this item: https://www.arca.fiocruz.br/handle/icict/25286
Title: Characterization of potentially virulent non-O1/non-O139 Vibrio cholerae strains isolated from human patients
Authors: Cariri, F. A. M. O.
Costa, A. P. R.
Melo, C. C.
Theophilo, G. N. D.
Hofer, E.
Melo Neto, O; P; de
Leal, N. C.
Affilliation: Fundação Oswaldo Cruz. Centro de Pesquisas Aggeu Magalhães. Departamento de Microbiologia. Recife, PE, Brasil.
Fundação Oswaldo Cruz. Centro de Pesquisas Aggeu Magalhães. Departamento de Microbiologia. Recife, PE, Brasil.
Fundação Oswaldo Cruz. Centro de Pesquisas Aggeu Magalhães. Departamento de Microbiologia. Recife, PE, Brasil.
Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Bacteriologia. Rio de Janeiro, RJ. Brasil.
Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Bacteriologia. Rio de Janeiro, RJ. Brasil.
Fundação Oswaldo Cruz. Centro de Pesquisas Aggeu Magalhães. Departamento de Microbiologia. Recife, PE, Brasil.
Fundação Oswaldo Cruz. Centro de Pesquisas Aggeu Magalhães. Departamento de Microbiologia. Recife, PE, Brasil.
Abstract: Traditional methods of typing Vibrio cholerae define virulent strains according to their recognition by sera directed against the known epidemic serogroups O1 and O139, overlooking potentially virulent non-O1/non-O139 strains. Here, we have undertaken the characterization of eight clinical isolates of non-O1/non-O139 V. cholerae, collected during cholera outbreaks in Brazil. Seven of these were typed as O26 and one, 17155, was defined as non-typable. A PCR-based approach has previously detected in these strains several virulence genes derived from the CTXvarphi prophage and generally associated with pathogenic strains. Here, the presence of the O1-specific wbeN gene was investigated through PCR and found to be restricted to strain 17155, as well as one of the O26 strains, 4756, although neither strain was recognized by O1-specific antisera. The same two isolates were the only strains able to express the cholera toxin in culture, assayed by western blotting. They also possessed four repeats of the heptanucleotide TTTTGAT upstream of the ctxAB genes encoding the cholera toxin. The remaining strains possessed only two intact repeats, whereas pathogenic O1 possessed four to six repeats. To define their evolutionary relationships, selected 16S-23S intergenic rRNA spacer regions were sequenced from the various strains and the resulting sequences used to build phylogenetic trees. Strains 4756 and 17155 always clustered with control O1 strains, whereas the remaining O26 strains clustered separately. These results confirm that, despite their serological phenotype, these two strains are genotypically related to O1 strains and potentially able to produce epidemic cholera.
Keywords: 16S–23S rRNA intergenic sequence
cholera
serogroup conversion
Vibrio cholerae non-O1/non-O139
virulence genes
keywords: Cólera
Vibrio cholerae
conversão de serogrupos
genes de virulência
Issue Date: 2010
Publisher: Elsevier
Citation: CARIRI, F. A. M. O. et al. Characterization of potentially virulent non-O1/non-O139 Vibrio cholerae strains isolated from human patients. Clin Microbiol Infect., v.16, p.62–67, 2010.
DOI: 10.1111/j.1469-0691.2009.02763.x
ISSN: 1198-743X
Copyright: restricted access
Appears in Collections:IOC - Artigos de Periódicos

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