Evaluation of culture media and antimicrobial susceptibility of Helicobacter pylori.

Abstract

Isolation of Helicobacter pylori on artificial culture is hampered by the lack of reliable and cheap media. In this study, three different types of culture media were evaluated for isolation of H. pylori from clinical specimens. These media included: Modified Thayer-Martin (MTM), Skirrow's campylobacter agar and chocolate agar. Modified Thayer-Martin agar was superior in isolation to others with an isolation rate of 47% (31/66). The size of colonies on this media were larger and clearly defined. Growth was detectable after 4 days of incubation, with a maximum growth after 7 days. Thirty one strains of H. pylori isolated from cases were tested against ten antibiotics (ampicillin, tetracycline, gentamicin, erythromycin, chloramphenicol, nalidixic acid, colistin, kanamycin, sulpharazole and metronidazole) in Mueller-Hinton agar, to determine the minimum inhibitory concentration (MIC). H. pylori was very susceptible to most drugs but resistant to nalidixic acid.