Antibiotic resistance conferred by a class 1 integron and SXT element in different Vibrio cholerae O-serotype isolated in Algeria

Abstract number: 1733_20

Ammari H., Ruimy R., Skurnik D., Andremont A., Mazel D., Guerout A., Assaous F., Rahal K.

Objectives: We investigated retrospectively antibiotic resistance, presence of integrons and SXT integrating conjugative element (SXT-ICE) in Vibrio cholerae isolates from the environment and from patients in several cities of Algeria, during the period from 1980 to 2003.

Methods: The strain collection was selected from a large number of V. cholerae studied previously for various phenotypic and genotypic characteristics. Single isolates differing by year, place of isolation and phenotypic pattern of antibiotic resistance were included in this study. Eighteen isolates (8 V. cholerae O1 and 10 V. cholerae non-O1, non-O139) were examined for the presence of: (i) class 1, 2 or 3 integrases by a triplex real-time PCR, (ii) SXT-ICE by PCR detection of the integrase gene. The resistance gene cassettes content within the different class 1 integrons were determined by DNA sequencing of the variable region located between the 5' and 3' conserved sequences.

Results: All V. cholerae O1 carried class 1 integron except two isolates of 1980 and one of 1997. One isolate of 1980, and two isolates of 1981, were found to contain two class 1 integrons carrying different cassettes (aacC and aadA1, dfr2 and aadA6). The 1986 isolate carried also 2 integrons which respectively contained dfr15 and aadA1. A single class 1 integron was found in the isolate of 1994, which carried aadA1 only. The SXT-ICE was only found in the isolates of 1994 and 1997.

Concerning V. cholerae non-O1, non-O139, class 1, 2 and 3 integrons were not detected for the isolates of 1985, 1987, 1996, 1997, 1999 and 2003, of which 5 of them were only resistant to ampicillin and one to sulfonamide. Two class 1 integrons were found in an isolate of 2001, which respectively contained aadA7, dfr1 and orfC sequence. Single class 1 integrons were found in three isolates, which contained respectively dfr7, aadA1 and aadA5-dfr17. SXT-ICE was not found in any isolate.

Conclusion: Our findings show that class 1 integrons are widespread among different clinical and environmental V. cholerae O1 and non-O1, non-O139 serotypes in Algeria with a high diversity of resistance cassettes, even in a 1980 strain which appears to be the oldest available V. cholerae O1 from Africa. The SXT-ICE was only found in V. cholerae O1 after 1986.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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