Sensitivity to nitazoxanide among metronidazole resistant Helicobacter pylori strains in patients with gastritis.
BACKGROUND
In this study, the efficacy of nitazoxanide in the treatment of Helicobacter pylori isolates, which were resistant to metronidazole, was examined.


METHODS
One hundred twenty two patients who underwent endoscopy examinations at Kasra and Laleh hospitals in Tehran from November 2014 to July 2015 were enrolled. Helicobacter pylori strains were isolated from the patients' endoscopy biopsies by bacteriological culture. Those bacterial isolates resistant to metronidazole were examined for susceptibility to nitazoxanide. Serial agar dilution method was utilized to determine the minimum inhibitory concentrations for the antibiotics.


RESULTS
From 122 gastric biopsy specimens, 55 H. pylori isolates were recovered (45%); of which, 40 (72.7%) were resistant to metronidazole. Comparing the MIC values of nitazoxanide with metronidazole revealed significant differences (p<0.05). The MIC50 and MIC90 values for nitazoxanide and metronidazole were 8 and ≥8μg/ml, and 32 and 64μg/ml, respectively.


CONCLUSIONS
The high levels of metronidazole resistance suggest that this medication may not be beneficial for first-line therapy in Iran. However, considering the relative effectiveness of nitazoxanide, it may be considered a suitable alternative for patients in Iran.
MSc, Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran. ak.baradaran@gmail.com.
Ali
A
Baradaran Moghaddam
Assistant Professor, Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran. masoud.alebouyeh@gmail.com.
Masoud
M
Alebouyeh
MSc, Research Institute for Gastroenterology and Liver Disease, Shahid Beheshti University of Medical Sciences, Tehran, Iran. nastaran_farzi@yahoo.com.
Nastaran
N
Farzi
MSc, Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran. markiz1918@gmail.com.
Saeed
S
Bayati
Professor, Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran. amirmozafari@yahoo.com.
Nour
N
Amirmozafari
Antibiotic Resistance; Helicobacter pylori; Metronidazole; Minimum Inhibitory Concentration; Nitazoxanide
Antimicrob Agents Chemother. 1996 Oct;40(10 ):2266-70
8891127
Case Rep Gastroenterol. 2014 Jan 27;9(1):36-42
25759631
Caspian J Intern Med. 2013 Fall;4(4):745-53
24294467
J Infect Chemother. 2007 Oct;13(5):291-5
17982716
Am J Trop Med Hyg. 1997 Jun;56(6):637-9
9230795
Gut. 2004 Oct;53(10):1445-51
15361493
Science. 1999 May 21;284(5418):1328-33
10334982
J Antimicrob Chemother. 2000 Jul;46(1):121-3
10882700
Gut. 2007 Oct;56(10):1353-7
17566020
Helicobacter. 2002 Dec;7(6):378-83
12485125
J Gastrointestin Liver Dis. 2011 Sep;20(3):299-304
21961099
Annu Rev Med. 1998;49:289-99
9509264
Antimicrob Agents Chemother. 2003 Dec;47(12 ):3780-3
14638482
Yale J Biol Med. 1998 Mar-Apr;71(2):135-41
10378359