Journal of Antimicrobial Chemotherapy (2002) 49, 601-609
© 2002 The British Society for Antimicrobial Chemotherapy
Review |
Helicobacter pylori susceptibility testing by disc diffusion
a Public Health Laboratory, Gloucestershire Royal Hospital, Great Western Road, Gloucester GL1 3NN; b Helicobacter Reference Unit, PHLS Central Public Health Laboratory, 61 Colindale Avenue, London NW9 5HT; c Public Health Laboratory, Bridle Path, York Road, Leeds TS15 7TR; d Public Health Laboratory, Southampton General Hospital, Southampton SO16 6YD; e Department of Medicine & Therapeutics, University of Glasgow, Western Infirmary, Glasgow GL11 6NT; f Department of Cellular Pathology, Northwick Park & St Mark's Hospitals, Watford Road, Harrow HA1 3UJ; g PHLS Communicable Disease Surveillance Centre, Lincoln House, Birmingham Heartlands Hospital, Bordesley Green East, Birmingham B9 5SS; h Public Health Laboratory, New Writtle Street, Chelmsford CM2 0YX, UK
The bacterium Helicobacter pylori is found in c. 40% of the population and is responsible for the development of duodenal disease. Triple treatment with a proton-pump inhibitor or bismuth salt plus two antibiotics is now commonplace in all patients diagnosed. As antibiotic resistance reduces treatment efficacy, it is time to consider routine susceptibility testing to guide individual patient treatment and surveillance of antibiotic resistance. There are no published nationally agreed standards for disc diffusion testing of H. pylori. After reviewing the literature, we recommend the following method for disc diffusion tests. A suspension of cultures 4 days old equivalent to McFarland Standard no. 4 (108 cfu/mL) should be used on Mueller–Hinton or Columbia agar base with 5–10% blood, using a metronidazole disc strength of 5 Ìg and a clarithromycin disc strength of 2 µg. Anaerobic pre-incubation of plates is unnecessary. A H. pylori control susceptible to metronidazole (e.g. NCTC 12822) should be used. Zone sizes with the Mueller–Hinton agar base for metronidazole testing are <16 mm resistant, 16–21 mm intermediate and >21 mm susceptible. We suggest that isolates in the intermediate zone should be re-tested by Etest. Zone sizes with the Columbia agar base for metronidazole testing are <10 mm resistant and 10 mm susceptible. Co-infection with two strains, which may be a mixture of isolates susceptible and resistant to metronidazole leading to conflicting susceptibility results, occurs in 5–10% of patients. Zone sizes with Mueller–Hinton agar and Columbia blood agar for clarithromycin testing are resistant no zone and susceptible any zone.
* Corresponding author. Tel: +44-1452-305334; Fax: +44-1453-307213; E-mail: jwhiting{at}phls.org.uk
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  N. C Elviss, R. J Owen, A. Breathnach, C. Palmer, and N. Shetty Helicobacter pylori antibiotic-resistance patterns and risk factors in adult dyspeptic patients from ethnically diverse populations in central and south London during 2000 J. Med. Microbiol., June 1, 2005; 54(6): 567 - 574. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. C. Elviss, R. J. Owen, J. Xerry, A. M. Walker, and K. Davies Helicobacter pylori antibiotic resistance patterns and genotypes in adult dyspeptic patients from a regional population in North Wales J. Antimicrob. Chemother., August 1, 2004; 54(2): 435 - 440. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. A.B. Cameron, K. U. Powell, L. Baldwin, P. Jones, G. D. Bell, and S. G.J. Williams Helicobacter pylori: antibiotic resistance and eradication rates in Suffolk, UK, 1991-2001 J. Med. Microbiol., June 1, 2004; 53(6): 535 - 538. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. J Jenks Causes of failure of eradication of Helicobacter pylori BMJ, July 6, 2002; 325(7354): 3 - 4. [Full Text] [PDF]
|
|