Comparison of new and classical point mutations associated with clarithromycin resistance in Helicobacter pylori strains isolated from dyspeptic patients and their effects on phenotypic clarithromycin resistance. Issue 4 (6th February 2019)

• Record Type: Journal Article
• Authors: Kocazeybek, Bekir; Sakli, Merve Kutlu; Yuksel, Pelin; Demirci, Mehmet; Caliskan, Reyhan; Sarp, Tevhide Ziver; Saribas, Suat; Demiryas, Suleyman; Kalayci, Fatma; Cakan, Huseyin; Uysal, Hayriye Kirkoyun; Gareayaghi, Nesrin; Ergin, Sevgi; Erzin, Yusuf Ziya; Bal, Kadir; Tascı, İhsan; Tokman, Hrisi Bahar
• Is Part Of: Journal of medical microbiology. Volume 68:Issue 4(2019)
• Page Start: 566
• Page End: 573
• Publication Date: 2019-02-06
• Subjects: Helicobacter pylori -- A2115G, A2144T and G2141A -- point mutations -- clarithromycin; Medical microbiology -- Periodicals; 616.9041
• DOI: 10.1099/jmm.0.000944
• Languages: English
• ISSNs: 0022-2615

Abstract

Abstract : Purpose. We aimed to investigate the presence of three recently identified point mutations (A2115G, G2141A and A2144T) of the 23 S rRNA gene and compare them with the three most frequently encountered point mutations (A2142G, A2142C and A2143G) in Helicobacter pylori strains in Turkey. Methodology. A total of 63 patients (mean 47.08±12.27) were included. The E-test method (for clarithromycin) was used for the clarithromycin antimicrobial susceptibility test of isolated H. pylori strains. Real-time PCR was used to detect the point mutations. Results. A total of 24 out of 63 H . pylori strains (38.1%) were detected as clarithromycin resistant (>0.5 mg l −1 ). The new A2115G ( n :6, 25%), A2144T ( n :7, 29.1%) and G2141A, 8 ( n :8, 33.3%) mutations and the classical A2142G ( n :8, 33.3%) and A2143G ( n :11, 45.8%) point mutations were detected in the 24 clarithromycin-resistant strains. The A2144T point mutation had the highest median MIC value (3 mg l −1 ) amongst the new mutations, but the classical mutations (A2142G and A2143G) had the highest median MIC values (256 mg l −1 ) overall. The presence of the A2115G (OR:31.66), A2144T (OR:36.92) or G2141A (OR:28.16) mutations increased the likelihood of clarithromycin resistance in H. pylori strains by 31.66-, 36.92- and 28.16-fold (ORs), respectively, according to the binary logistic regression analysis. Conclusion . We concluded that classical mutations of the 23 S rRNA gene resulted in higher clarithromycin MIC values than new mutations. These new point mutations caused moderate elevations in the MIC values of clarithromycin-resistant H. pylori strains.