Resistance to Amoxicillin and Clarithromycin in Helicobacter pylori isolates in a tertiary care hospital
Author Details : Lavanya Jeyamani*, Jayalakshmi Jayarajan, Ventatakrishnan Leelakrishnan, Mukundan Swaminathan
Journal Title:Indian Journal Of Microbiology Research
Introduction: Amoxicillin and Clarithromycin are the two most often chosen first line drugs in eradication
therapy for H. Pylori, owing to their better efficacy. Unlike other bacterial infections, therapy here is not
based on individual susceptibility report for this bacterium. Rather an empirical regimen is chosen based on
the prevalent resistance report in a given population. Current study is aimed at determining the resistance
rate in our study population for amoxicillin (AMX) & Clarithromycin (CLA) and to determine if these two
drugs can be continued as first line regimen.
Materials and Methods: Gastric biopsy samples from 165 dyspeptic patients obtained through endoscopy
was cultured in Brucella Chocolate agar (BCA). Among them 46 samples were showing sufficient growth
of H. Pylori for antibiotic susceptibility testing. MIC for AMX and CLA was determined by E-strip method
based on standard guidelines.
Results: 91.3 percent of isolates were susceptible or moderately susceptible to CLA. Percentage of isolates
within the proposed epidemiological cut off for AMX was 76.
Conclusion: H.pylori isolates in our study population had resistance rate well below the cut off (20%) for
CLA and it could be safely used as first line regimen in treating patients from this region of the country.
On the contrary, more than 20% of the strains had MIC above the proposed Epidemiological cut off for
AMX. Hence an increase in dosage and frequency of dosage, in combination with a potent anti-H.pylori
drug could be used in treatment. Clinical trials are required to study efficacy of AMX based regimen in
non susceptible patients. Serial monitoring of biological resistance is required for both these drugs, to
determine the change in susceptibility pattern at the earliest.
Keywords: Amoxicillin, Clarithromycin, Antibiotic susceptibility test, Minimum Inhibitory Concentration, Helicobacter pylori.
Doi : 10.18231/j.ijmr.2019.063