TY - JOUR
T1 - Metronidazole and clarithromycin resistance in Helicobacter pylori determined by measuring MICs of antimicrobial agents in color indicator egg yolk agar in a miniwell format
AU - Vasquez, A.
AU - Valdez, Y.
AU - Gilman, R. H.
AU - McDonald, J. J.
AU - Westblom, T. U.
AU - Berg, D.
AU - Mayta, H.
AU - Gutierrez, V.
AU - Berendson, Robert
AU - Leon-Barua, Raul
AU - Ramirez-Ramos, Alberto
AU - Recavarren-Arce, Sixto
AU - Watanabe, Jose
PY - 1996
Y1 - 1996
N2 - Resistance of Helicobacter pylori to metronidazole often causes failure of commonly used combination drug treatment regimens. We determined the MICs of metronidazole and clarithromycin against 18 H. pylori strains from Peru using tetrazolium egg yolk (TEY) agar. The MIC results obtained by agar dilution with petri dishes were compared with the results found through a miniwell format. The results of the two protocols for measuring drug susceptibility differed by no more than 1 dilution in all cases. On TEY agar, bright-red H. pylori colonies were easy to identify against a yellow background. Sixty-one percent (11 of 18) of the strains were resistant to metronidazole (MIC, ≥4 μg/ml) and 50% (9 of 18) were resistant to clarithromycin (MIC, ≥0.125 μg/ml), whereas none (0 of 5) of the strains tested were resistant to tetracycline (MIC, ≥1 μg/ml). Thus, the prevalence of metronidazole and clarithromycin resistance in Peru is higher than that in developed regions of the world. The miniwell plate with TEY agar allows easy H. pylori colony identification, requires about one-third less of the costly medium necessary for petri dish assaying, conserves space, and yields MICs equivalent to those with agar dilution in petri dishes.
AB - Resistance of Helicobacter pylori to metronidazole often causes failure of commonly used combination drug treatment regimens. We determined the MICs of metronidazole and clarithromycin against 18 H. pylori strains from Peru using tetrazolium egg yolk (TEY) agar. The MIC results obtained by agar dilution with petri dishes were compared with the results found through a miniwell format. The results of the two protocols for measuring drug susceptibility differed by no more than 1 dilution in all cases. On TEY agar, bright-red H. pylori colonies were easy to identify against a yellow background. Sixty-one percent (11 of 18) of the strains were resistant to metronidazole (MIC, ≥4 μg/ml) and 50% (9 of 18) were resistant to clarithromycin (MIC, ≥0.125 μg/ml), whereas none (0 of 5) of the strains tested were resistant to tetracycline (MIC, ≥1 μg/ml). Thus, the prevalence of metronidazole and clarithromycin resistance in Peru is higher than that in developed regions of the world. The miniwell plate with TEY agar allows easy H. pylori colony identification, requires about one-third less of the costly medium necessary for petri dish assaying, conserves space, and yields MICs equivalent to those with agar dilution in petri dishes.
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U2 - 10.1128/jcm.34.5.1232-1234.1996
DO - 10.1128/jcm.34.5.1232-1234.1996
M3 - Article
C2 - 8727909
AN - SCOPUS:9244264392
SN - 0095-1137
VL - 34
SP - 1232
EP - 1234
JO - Journal of clinical microbiology
JF - Journal of clinical microbiology
IS - 5
ER -