Vibrio cholerae resistant to 2,4-diamino-6,7-diisopropylpteridine (O/129) isolated from patients with enteritis in Ceará, Brazil.

This paper reports the characterization of clinical Vibrio cholerae resistant to vibriostatic agent O/129, using classical and plasmid analysis. In a study conducted during December 1991-September 1993, two of 7,058 V. cholerae strains, obtained from patients suspected to have cholera in the State of Ceará, northeast Brazil, were resistant to 150 micrograms of the vibriostatic agent O/129 (2,4-diamino-6,7-diisopropylpteridine). One strain was identified as V. cholerae O1 El Tor Inaba and the other one as serogroup O22. Only one O1 strain harboured a plasmid of 147 kb transferable to Escherichia coli K12, and five strains of V. cholerae O1 and non-O1 were sensitive to O/129 and plasmid-negative at a frequency between 8 x 10(-2) and 3.6 x 10(-5). Additionally, O/129-resistant strains of V. cholerae O1 and O22 were resistant to trimethoprim/sulphamethoxazole.

[The emergence of multiple antimicrobial resistance in Vibrio cholerae isolated from gastroenteritis patients in Ceará, Brazil]. / Emergência da múltipla resistência a antimicrobianos em Vibrio cholerae isolados de pacientes com gastroenterite no Ceará, Brasil.

Of 7058 Vibrio cholerae strains recovered from patients suspected of cholera in the State of Ceará between December 1991 and September 1993, two were resistant to antimicrobials (Ampicillin, erythromycin, trimethoprim-sulfamethoxazole, tetracycline) and to vibriostatic agent O/129 (2,4-diamino-6,7-diisopropylpteridine). From the bacteriological standpoint, one strain was identified as V. cholerae serogroup O:1, biotype El Tor, serovar Inaba, and another as V. cholerae serogroup O:22, biochemically classified as Heiberg type II. It was shown that only in the serogroup O:1 strain, multiple resistance was encoded by a plasmid transferrable by conjugation to Escherichia coli K12 and a sensitive strains of V. cholerae O1 and non-O1, with at a frequency between 8 x 10(-2) and 5 x 10(-6). The plasmid, with a molecular weight of 147 Kb, encoded both multiple resistance to antimicrobials and the vibriostatic compound (O/129), compatible with descriptions reported in other parts of world.