Brief Article
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World J Gastroenterol. Apr 28, 2014; 20(16): 4761-4770
Published online Apr 28, 2014. doi: 10.3748/wjg.v20.i16.4761
Helicobacter pylori isolates from ethnic minority patients in Guangxi: Resistance rates, mechanisms, and genotype
Li-Juan Zhao, Yan-Qiang Huang, Bing-Pu Chen, Xiao-Qiang Mo, Zan-Song Huang, Xiao-Feng Huang, Lian-Deng Wei, Hong-Yu Wei, Yuan-Hong Chen, Hua-Ying Tang, Gan-Rong Huang, Yan-Chun Qin, Xiao-Hua Li, Lu-Yao Wang
Li-Juan Zhao, Yan-Qiang Huang, Bing-Pu Chen, Xiao-Qiang Mo, Zan-Song Huang, Xiao-Feng Huang, Lian-Deng Wei, Hong-Yu Wei, Yuan-Hong Chen, Hua-Ying Tang, Gan-Rong Huang, Yan-Chun Qin, Xiao-Hua Li, Lu-Yao Wang, Department of Medical Microbiology and Immunology, You Jiang Medical College for Nationalities, Baise 533000, Guangxi Zhuang Autonomous Region, China
Author contributions: Huang XF, Wei LD and Wei HY performed the majority of experiments; Chen YH, Tang HY, Huang GR, Qin YC, Li XH and Wang LY provided vital reagents and analytical tools and were also involved in editing the manuscript; Chen BP, Mo XQ and Huang ZS co-ordinated and provided the collection of all the human material in addition to providing financial support for this work; Zhao LJ and Huang YQ designed the study and wrote the manuscript; Zhao LJ and Huang YQ contributed equally to this work.
Supported by Nature Science Foundation of Guangxi, No. 2012GXNSFAA053172; and The School to School and Enterprise to build the innovation platform in 2013, Guangxi Scientific Research, No. 2013-8
Correspondence to: Yan-Qiang Huang, Associate Professor, Department of Medical Microbiology and Immunology, You Jiang Medical College for Nationalities, 98 Countryside Road, Baise 533000, Guangxi Zhuang Autonomous Region, China. hyq77615@163.com
Telephone: +86-776-2853272  Fax: +86-776-2853272
Received: November 27, 2013
Revised: February 25, 2014
Accepted: March 7, 2014
Published online: April 28, 2014
Abstract

AIM: To investigate the rate of Helicobacter pylori (H. pylori) resistance to clarithromycin among ethnic minority patients in Guangxi, explore the underlying mechanisms, and analyze factors influencing genotype distribution of H. pylori isolates.

METHODS: H. pylori strains were isolated, cultured and subjected to drug sensitivity testing. The 23S rRNA gene of H. pylori isolates was amplified by PCR and analyzed by PCR-RFLP and direct sequencing to detect point mutations. REP-PCR was used for genotyping of H. pylori isolates, and NTsys_2 software was used for clustering analysis based on REP-PCR DNA fingerprints. Factors potentially influencing genotype distribution of H. pylori isolates were analyzed.

RESULTS: The rate of clarithromycin resistance was 31.3%. A2143G and A2144G mutations were detected in the 23S rRNA gene of all clarithromycin-resistant H. pylori isolates. At a genetic distance of 78%, clarithromycin-resistant H. pylori isolates could be divided into six groups. Significant clustering was noted among H. pylori isolates from patients with peptic ulcer or gastritis.

CONCLUSION: The rate of clarithromycin resistance is relatively high in ethnic minority patients in Guangxi. Main mechanisms of clarithromycin resistance are A2143G and A2144G mutations in the 23S rRNA gene. Clarithromycin-resistant H. pylori isolates can be divided into six groups based on REP-PCR DNA fingerprints. Several factors such as disease type may influence the genotype distribution of H. pylori isolates.

Keywords: Helicobacter pylori, Antibiotic resistance, Mechanism, Clarithromycin, Genotype

Core tip: The present study showed that the rate of Helicobacter pylori (H. pylori) resistance to clarithromycin was 31.3% in ethnic minority patients in Guangxi, slightly higher than that in Dongguan in 2009 but significantly higher than the reported resistance rate in 2008 in the same region (Guangxi). The significant increase in the rate of H. pylori resistance to clarithromycin in this region may be caused by the long-term and/or wide use of clarithromycin, which can decrease the populations of sensitive bacteria and promote the propagation of drug-resistant bacteria. Of note, this study also found that there existed multidrug resistant H. pylori strains (resistant to amoxicillin, metronidazole, tetracycline, and levofloxacin).