New qnr Gene Cassettes Associated with Superintegron Repeats in Vibrio cholerae O1
2008

New qnr Gene Cassettes in Vibrio cholerae O1

publication Evidence: moderate

Author Information

Author(s): Érica L. Fonseca, Fernanda dos Santos Freitas, Verônica V. Vieira, Ana C.P. Vicente

Primary Institution: Instituto Oswaldo Cruz, Rio de Janeiro, Brazil

Hypothesis

The qnrVC1 gene cassette could have originated from a V. parahaemolyticus SI, whereas qnrVC2 originated in V. cholerae.

Conclusion

The study reports the emergence of two new qnr genes associated with superintegron repeats in Vibrio cholerae O1.

Supporting Evidence

  • The qnrVC1 gene showed high amino acid divergence compared with all qnr genes described.
  • Qnr proteins belong to the pentapeptide repeat family, which play a role in DNA gyrase protection.
  • The qnrVC gene cassettes are characterized by attC sites, which are absent in all other qnr genes already identified.
  • Strain VC627 shows a 10-fold increase in resistance to ciprofloxacin compared with strains from the seventh pandemic lineage in Brazil.

Takeaway

Scientists found new genes in a bacteria that make it resistant to a type of medicine. These genes came from other bacteria and can make treating infections harder.

Methodology

V. cholerae O1 isolates from the cholera epidemic in Brazil were screened for antimicrobial drug resistance and class 1 integrons.

Participant Demographics

Clinical strains of V. cholerae O1 from the cholera epidemic in Brazil (1991–2000).

Digital Object Identifier (DOI)

10.3201/eid1407.080132

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