Open Access Research

Primary antibiotic resistance and associated mechanisms in Helicobacter pylori isolates from Senegalese patients

Abdoulaye Seck1, Christophe Burucoa2, Daouda Dia3, Mouhamadou Mbengue3, Manuella Onambele1, Josette Raymond4 and Sebastien Breurec1*

Author Affiliations

1 Institut Pasteur, Unité de Biologie Médicale et Environnementale, 36 avenue pasteur, Dakar, BP220, Senegal

2 EA 4331 LITEC, Université de Poitiers, CHU de Poitiers, Laboratoire de Bactériologie-Hygiène, 2, rue de la Miletrie, Poitiers, BP 577, 86021, France

3 Département de Gastro-entérologie, Centre Hospitalier Le Dantec, 30 avenue Pasteur, BP3001, Dakar, Senegal

4 Unité Postulante de Pathogénèse de Helicobacter, Institut Pasteur, 25-28 rue du Docteur Roux, 75724, Paris Cedex 15, France

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Annals of Clinical Microbiology and Antimicrobials 2013, 12:3  doi:10.1186/1476-0711-12-3

Published: 8 January 2013

Abstract

Background

Antibiotic combination therapy for Helicobacter pylori eradication must be adapted to local resistance patterns, but the epidemiology of H. pylori resistance to antibiotics is poorly documented in Africa. The aim was to determine the antibiotic resistance rates, as well as the associated molecular mechanisms, of strains isolated in Dakar, Senegal.

Methods

One hundred and eight H. pylori strains were isolated between 2007 and 2009 from 108 patients presenting with upper abdominal pain to the Gastroenterology Department of Le Dantec Hospital. Antimicrobial susceptibility testing was performed for amoxicillin, clarithromycin, metronidazole, levofloxacin and tetracyclin using the E-test method. Mutations in the 23S rRNA gene of clarithromycin-resistant strains and in gyrA and gyrB of levofloxacin-resistant strains were investigated.

Results

Isolates were characterized by no resistance to amoxicillin (0%), tetracycline (0%), and very low rate of resistance to clarithromycin (1%), but a high rate of resistance to metronidazole (85%). The clarithromycin-resistant strain displayed the A2143G mutation. A worrying rate of levofloxacin resistance was detected (15%). N87I and D91N were the most common mutations in the quinolone-resistance-determining region of gyrA.

Conclusions

The first-line empirical regimen for H. pylori eradication in Senegal should include clarithromycin. Increasing rates of fluoroquinolone resistance detected should discourage the use of levofloxacin-containing regimens without prior antimicrobial susceptibility testing.

Keywords:
Helicobacter pylori; Levofloxacin; Clarithromycin; Antibiotic resistance; Senegal