Antimicrobial susceptibility testing for Helicobacter pylori isolates from Brazilian children and adolescents: comparing agar dilution, E-test, and disk diffusion

Antimicrobial susceptibility testing for Helicobacter pylori isolates from Brazilian children and adolescents: comparing agar dilution, E-test, and disk diffusion

Author Ogata, Silvio Kazuo Autor UNIFESP Google Scholar
Gales, Ana Cristina Autor UNIFESP Google Scholar
Kawakami, Elisabete Autor UNIFESP Google Scholar
Institution Universidade Federal de São Paulo (UNIFESP)
Abstract Antimicrobial susceptibility testing for Helicobacter pylori is increasingly important due to resistance to the most used antimicrobials agents. Only agar dilution method is approved by CLSI, but it is difficult to perform routinely. We evaluated the reliability of E-test and disk diffusion comparing to agar dilution method on Helicobacter pylori antimicrobial susceptibility testing. Susceptibility testing was performed for amoxicillin, clarithromycin, furazolidone, metronidazole and tetracycline using E-test, disk-diffusion and agar dilution method in 77 consecutive Helicobacter pylori strains from dyspeptic children and adolescents. Resistance rates were: amoxicillin - 10.4%, 9% and 68.8%; clarithromycin - 19.5%, 20.8%, 36.3%; metronidazole - 40.2%33.7%, 38.9%, respectively by agar dilution, E-test and disk diffusion method. Furazolidone and tetracycline showed no resistance rates. Metronidazole presented strong correlation to E-test (r = 0.7992, p < 0.0001) and disk diffusion method (r=-0.6962, p < 0.0001). Clarithromycin presented moderate correlation to E-test (r = 0.6369, p < 0.0001) and disk diffusion method (r=-0.5656, p < 0.0001). Amoxicillin presented weak correlation to E-test (r = 0.3565, p = 0.0015) and disk diffusion (r=-0.3565, p = 0.0015). Tetracycline presented weak correlation with E-test (r = 0.2346, p = 0.04) and furazolidone to disk diffusion (r=-0.0288, p = 0.8038). E-test presented better agreement with gold standard. It is an easy and reliable method for Helicobacter pylori susceptibility testing. Disk diffusion method presented high disagreement and high rates of major errors.
Keywords Helicobacter pylori
E-test
disk diffusion
susceptibility test
Language English
Date 2014-12-01
Published in Brazilian Journal of Microbiology. Sociedade Brasileira de Microbiologia, v. 45, n. 4, p. 1439-1448, 2014.
ISSN 1517-8382 (Sherpa/Romeo, impact factor)
Publisher Sociedade Brasileira de Microbiologia
Extent 1439-1448
Origin http://dx.doi.org/10.1590/S1517-83822014000400039
Access rights Open access Open Access
Type Article
Web of Science ID WOS:000350200100039
SciELO ID S1517-83822014000400039 (statistics in SciELO)
URI http://repositorio.unifesp.br/handle/11600/8731

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