Drug resistance pattern and clonality in H. pylori strains.
BACKGROUND
This aim of this work was to determine the in vitro activity of clarithromycin, amoxycillin, metronidazole and tetracycline against Helicobacter pylori and clonality among resistant and sensitive strains isolated from North India.


METHODS
A total of 68 H. pylori isolates from peptic ulcer disease and non ulcer dyspepsia patients were examined. These strains were subjected for determination of minimum inhibitory concentration of clarithromycin, amoxycillin, metronidazole and tetracycline. For molecular characterization of resistant and sensitive strains, enterobacterial repetitive intergenic consensus sequences (ERIC) and random amplified polymorphic DNA-PCR (RAPD-PCR) methods were used.


RESULTS
All the tested isolates were found resistant to metronidazole, while 65% were resistant to amoxycillin and 4.7% were resistant to clarithromycin. However, none of the isolates were found to be resistant to tetracycline. Molecular fingerprinting and cluster analysis of resistant and sensitive strains did not give clues for clonal spread of resistant strains.


CONCLUSIONS
Various chromosomal mutations were seen in the putative resistance genes of resistant strains, possibly indicating selection pressure as the major cause of high resistance.
Singh
Varsha
V
Department of Biochemistry, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
Mishra
Shrutkirti
S
Maurya
Pushpa
P
Rao
Grkoteswar
G
Jain
Ashok Kumar
AK
Dixit
Vinod Kumar
VK
Gulati
Anil Kumar
AK
Nath
Gopal
G
D000293:Adolescent; D000328:Adult; D000368:Aged; D000658:Amoxicillin / Q000494:pharmacology; D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D017291:Clarithromycin; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D005260:Female; D016481:Helicobacter Infections / Q000453:epidemiology / Q000382:microbiology; D016480:Helicobacter pylori / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D008795:Metronidazole / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D010437:Peptic Ulcer / Q000382:microbiology; D013752:Tetracycline / Q000494:pharmacology; D001618:beta-Lactamases / Q000494:pharmacology
D000891:Anti-Infective Agents, Local; D008795:Metronidazole; D000658:Amoxicillin; D001618:beta-Lactamases; D013752:Tetracycline; D017291:Clarithromycin