BACKGROUND:To investigate the antibiotic resistance of Helicobacter pylori (H. pylori) strains to clarithromycin, metronidazole, amoxicillin, levofloxacin, furazolidone, and tetracycline in Chinese children.MATERIALS AND METHODS:This multicenter, retrospective study was conducted from January 2016 through May 2023. Gastric mucosa biopsies were obtained from pediatric participants who underwent upper gastrointestinal endoscopy at 96 hospitals in northern, southwestern, and southeastern China. The susceptibility of H. pylori to six commonly used antibiotics was determined by agar dilution method.RESULTS:Among the 3074 H. pylori isolates, 36.7% were resistant to clarithromycin, 77.3% to metronidazole, 16.6% to levofloxacin, and 0.3% to amoxicillin. No strains were detected to be resistant to furazolidone or tetracycline. During the 8-year study period, resistance to clarithromycin and metronidazole showed a significant upward trend, while the resistance pattern of the other antibiotics demonstrated a slight but nonsignificant fluctuation. Significant regional differences were found in the distribution of clarithromycin resistance among the northern (66.0%), southwestern (48.2%), and southeastern (34.6%) regions. The metronidazole resistance rate was significantly lower in the southeastern coastal region (76.3%) than in the other two regions (88.2% in the north and 87.7% in the southwest). Multi-drug resistance for two or more antibiotics was detected in 36.3% of the H. pylori strains, and the predominant multi-resistance pattern was the dual resistance to clarithromycin and metronidazole.CONCLUSIONS:The prevalence of H. pylori resistance to clarithromycin and metronidazole is rather high in Chinese children and has been increasing over time. A relatively high resistance rate to levofloxacin was also noticed in children, while almost all strains were susceptible to amoxicillin, furazolidone, and tetracycline. It will be of great clinical significance to continuously monitor the antibiotic-resistance patterns of H. pylori in the pediatric population.

The issue of drug resistance of Helicobacter pylori is becoming increasingly serious. To analyze the correlation between the cagA and vacA genotypes of H. pylori strains and their resistance to metronidazole, levofloxacin, and clarithromycin in patients in Xi’an, we studied 117 H. pylori strains isolated from patients in Xi’an. Antibiotic susceptibility testing of H. pylori was performed. The cagA and vacA genotypes were investigated using PCR. Among 117 strains of H. pylori, the rate of detection of cagA was 91.45

目的 针对胃黏膜组织标本的幽门螺杆菌(HP)感染诊断的real time-PCR检测和分离培养2种最常用方法进行结果一致性分析,为HP感染诊断方法的选择提供科学依据.方法 在浙江省4个地区(萧山、温岭、苍南和湖州)各选取1所医院,采集2020年11月16日至12月7日送至杭州致远检验医学研究所进行HP分离培养和耐药性分析的全部患者胃窦部黏膜活检标本,共1 312份.每份样本经研磨匀浆处理后分为2份,分别用于常规HP分离培养和real time-PCR检测(以cagH为检测靶点),2种方法平行双盲进行.检测结果的一致性及不同医院来源样本间的差异用x2检验、Fisher精确检验以及独立样本t检验等统计学方法进行分析.结果 1 312份样本中,分离培养法和real time-PCR法的阳性率分别为29.34％(385/1 312)、28.51％(374/1 312),差异无统计学意义(P=0.636).来自4所医院的标本,2种方法的检出率差异均无统计学意义(P=0.075),二者在萧山某院、温岭某院、苍南某院、湖州某院样本以及总体样本中的Kappa值分别为0.84、0.89、0.75、0.91、0.85.real time-PCR法的灵敏度和特异度分别为89.26％、100.00％.在real time-PCR法检测阳性而培养阴性的样本中,检测Ct值为25.47～34.97,均值为30.90,90％的Ct值均≤34.46,频数最高组为29.00～30.00组.结论 分离培养法和real time-PCR法在临床胃黏膜标本HP诊断中均可达到较高的检测效能,且2种方法检出结果一致性良好,可应用于HP个体化治疗,以便在做出HP感染诊断的同时提供受检者的药敏检测结果.标本中HP菌量及标本的保存运输条件可能对结果产生重要影响.

BACKGROUND:To determine the prevalence of Helicobacter pylori infection and the antibiotic susceptibility of H. pylori in patients after partial gastrectomy. METHODS:Patients who underwent gastroscopy from January 2009 to November 2017 and had a history of partial gastrectomy were retrospectively enrolled in the remnant stomach group. Contemporary non-gastrectomized patients with an endoscopic diagnosis of chronic gastritis were enrolled in the non-operated stomach group. The detection of H. pylori infection was performed by culture and histology. The in vitro antimicrobial susceptibility was examined by the agar dilution method on strains from gastric biopsies. RESULTS:In this study, a total of 728 gastrectomized and 5035 non-gastrectomized patients were included. There was a significantly lower prevalence of H. pylori infection in the gastric-remnant patients (8.65%) than in the non-gastrectomized patients (17.76%) (P < .001) with the diagnostic method of culture. In the gastric-remnant patients, the H. pylori strains had resistance rates to metronidazole, clarithromycin, levofloxacin, amoxicillin, and furazolidone of 100%, 20.63%, 22.22%, 0%, and 0%, respectively. In the nongastrectomized patients, H. pylori resistance to metronidazole, clarithromycin, levofloxacin, amoxicillin, and furazolidone was 90.49%, 24.61%, 21.70%, 0.22%, and 0.11%, respectively. Gastric-remnant patients had a significantly higher metronidazole resistance rate than non-gastrectomized patients (P = .005). Moreover, no significant changes in the resistance to 5 antibiotics were observed among the gastric-remnant patients from different age, gender, and surgical indication groups. CONCLUSION:Patients after partial gastrectomy showed a lower prevalence of H. pylori infection. Gastric-remnant patients were more likely to harbor metronidazole-resistant H. pylori strains.

An effective eradication therapy of Helicobacter pylori (H. pylori) should be used for the first time. In this study, we assessed whether tailored therapy based on antibiotic susceptibility testing is more effective than traditional therapy. We also evaluated the factors that cause treatment failure in high-resistance areas. For this multicenter trial, we recruited 467 H. pylori-positive patients. The patients were randomly assigned to receive tailored triple therapy (TATT), tailored bismuth-containing quadruple therapy (TABQT), or traditional bismuth-containing quadruple therapy (TRBQT). For the TATT and TABQT groups, antibiotic selection proceeded via susceptibility testing using an agar-dilution test. The patients in the TRBQT group were given amoxicillin, clarithromycin, esomeprazole, and bismuth. Successful eradication was defined as a negative 13C-urea breath test at least eight weeks after the treatment ended. Susceptibility testing was conducted using an agar-dilution test. The eradication rate was examined via intention-to-treat (ITT) and per-protocol (PP) analyses. The clarithromycin, levofloxacin, and metronidazole resistance rates were 26.12%, 28.69%, and 96.79%, respectively. Resistance against amoxicillin and furazolidone was rare. The eradication rates for TATT, TRBQT, and TABQT were 67.32%, 63.69%, and 85.99% in the ITT analysis (P<0.001) and 74.64%, 68.49%, and 91.22% in the PP analysis (P<0.001), respectively. The efficacy of TABQT was affected by clarithromycin resistance, and bismuth exerted a direct influence on TATT failure. TABQT was the most efficacious regimen for use in high-resistance regions, especially among clarithromycin-susceptible patients.

Abstract Background After the failure of clarithromycin- and bismuth-based quadruple therapy (CBQT), levofloxacin- and bismuth-based quadruple therapy (LBQT) is recommended for Helicobacter pylori eradication. We compared the efficacies of second-line tailored bismuth-based quadruple therapy (TBQT) and empirical LBQT. Methods Patients with CBQT failure were randomly assigned to receive TBQT or LBQT for 14 days. All patients underwent endoscopy for culture-based antibiotic susceptibility testing. Patients in the TBQT group exhibiting levofloxacin susceptibility were randomized to receive amoxicillin, levofloxacin, esomeprazole, and colloidal bismuth pectin (ALEB) or amoxicillin, furazolidone, esomeprazole, and colloidal bismuth pectin (AFEB) for 14 days; patients with levofloxacin resistance received AFEB. Results From May 2016 to June 2019, 364 subjects were enrolled. Eradication rates were significantly higher in the TBQT group (n = 182) than in the LBQT group (n = 182) according to both intention-to-treat (ITT) analysis (89.6% vs. 64.8%, P < 0.001) and per protocol (PP) analysis (91.1% vs. 67.8%, P < 0.001). Among patients in the TBQT group with levofloxacin susceptibility, eradication rates were similar in the ALEB (n = 51) and AFEB (n = 50) subgroups according to both the ITT (86.3% vs. 90.0%, P = 0.56) and PP (88.0% vs. 90.0%, P = 0.75) analyses. Isolated clarithromycin and levofloxacin resistance rates were 57.7% and 44.5%, respectively. The total clarithromycin and levofloxacin resistance rate in strains with dual or triple resistance was 35.7%. Conclusions TBQT was more effective than LBQT as a second-line strategy after CBQT failure. In the absence of antibiotic susceptibility testing, AFEB therapy might be used as a rescue therapy to eradicate H. pylori and avoid levofloxacin resistance. Trial registration: Chinese Clinical Trial Registry ( www.chictr.org.cn ): ChiCTR1900027743.

目的 观察并比较非萎缩性胃炎4种不同的以铋剂为主的四联幽门螺杆菌(Hp)根除疗法的效果.方法 选取Hp阳性非萎缩性胃炎患者864例,先取胃黏膜组织进行细菌分离培养和药敏试验,然后根据药敏试验结果选用不同的以铋剂为主的四联根除疗法(口服枸橼酸铋钾220mg、雷贝拉唑20mg、阿莫西林1 000mg,2次/d,再加服1种敏感抗生紊),分别为呋喃唑酮组(220例,加服呋喃唑酮100mg,2次/d)、克拉霉素组(216例,加服克拉霉素500mg,2次/d)、左氧氟沙星组(212例,加服左氧氟沙星200mg,2次/d)、甲硝唑组(216例,加服甲硝唑400mg,3次/d).14d为1个疗程.观察并比较4组患者Hp根除率和治疗期间不良反应发生率.结果 4组患者Hp根除率比较差异有统计学意义(P＜0.05),组间两两比较,呋喃唑酮组Hp根除率＞甲硝唑组＞左氧氟沙星组(均P＜0.05),克拉霉素组Hp根除率＞左氧氟沙星组(P＜0.05),其余各组两两比较差异均无统计学意义(均P＞0.05).4组患者治疗期间不良反应发生率比较差异无统计学意义(P＞0.05).结论 含呋喃唑酮的以铋剂为主的四联根除疗法根除非萎缩性胃炎患者的Hp安全、有效,尚不需顾虑是否耐药,可作为舟山市岱山县地区Hp阳性非萎缩性胃炎患者的初次治疗方案.

Objectives: A personalised diagnosis kit for Helicobacter pylori that employs visual gene chip technology for the simultaneous detection of CYP2C19 polymorphisms and clarithromycin/levofloxacin antibiotic resistance was evaluated. Methods: Gastric antrum mucosa biopsy specimens of 394 patients were tested using the kit. DNA sequencing and antibiotic susceptibility testing of the H. pylori were also performed. Results: In total, 267 (67.8%) of the 394 specimens were positive for H. pylori using the kit and DNA sequencing, and 136 (34.5%) were positive by culturing. For human CYP2C19 and the bacterial 23S rRNA and gyrA genes, the concordance rates were 92.4% (364/394), 96.6% (258/267) and 97.0% (259/267) between the kit and DNA sequencing results, respectively. For clarithromycin and levofloxacin resistance, the concordance rates were 90.4% (123/136) and 81.6% (111/136) between the kit and antibiotic susceptibility testing results. Conclusions: The personalised diagnosis kit for H. pylori provides useful information for the choice of proton pump inhibitor and antibiotic in combination therapy. (C) 2018 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

Objective To establish a method for determining the copy number ratio of bacterial and human genome.Methods The specific primers and universal probes were designed for bacterial and human gene, respectively. The mixed samples consisted of E. coli, Helicobacter pylori and human blood and were quantified by TaqMan-MGB fluorescent PCR. The feasibility and accuracy were evaluated by comparing the measured ratio (the ratio of the Ct values converted into the copy number) and the theoretical ratio.Results The co-efficient of variation (CV) values of six samples (DB1, DB2, DB3, DH1, DH2 and DH3) were 4.48%, 1.57%, 4.67%, 1.55% , 0.49% and 1.29% by CV analysis, respectively. In the nine mixed samples, the error was less than 0.1 for the measured ratio (DB/DH) and the theoretical ratio, in which the correlation was significant between the two groups (r = 1.000, P < 0.001).Conclusions The method for determining the copy number ratio between bacterial and human genome based on TaqMan-MGB fluorescent quantitative PCR was reproducible and accurate, and could be used to determine the copy number ratio between bacteria and human genome.

Background. Helicobacter pylori (H. pylori) is one of the most frequent and persistent bacterial infections that affect nearly half of the world’s population. Antibiotic resistance is a constantly evolving process and local surveillance of antibiotic resistance is warranted to guide clinicians in their choice of therapy. The aim of this study was to establish a microarray-based detection to identify H. pylori infection, clarithromycin and levofloxacin susceptibility, and CYP2C19 genetic polymorphism and guide to potential choice of proton pump inhibitor (PPI), antibiotic administration for tailored H. pylori eradication therapy. Methods. By analyzing the sequence of human genomic CYP2C19⁎2 and CYP2C19⁎3 and mutations within the 23S rRNA and gyrA gene regions conferring clarithromycin and levofloxacin resistance, respectively, we developed a microarray for individual therapy detection of H. pylori infection. Plasmids were established as positive or limit of detection (LOD) reference materials. The specificity and sensitivity of the microarray had been performed. And a total of 1083 gastric biopsy samples were tested and the Kappa value had been calculated between the array and Sanger sequencing. We also analyzed the resistance to clarithromycin and levofloxacin in China, as well as the CYP2C19 polymorphisms. Results. The LOD of detecting H. pylori was 103 CFU/mL and human genome DNA was 2 ng/μL. The detection results of 1083 gastric biopsy samples showed that 691 (63.80%) were H. pylori positive, of which 266 (38.49%) were resistant to clarithromycin, 192 (27.79%) were resistant to levofloxacin, and 61 (8.83%) were resistant to both of them. For the type of CYP2C19 polymorphism, 412 (38.04%) were homozygous fast type (HomEM), 574 (53%) were heterozygous EM (HetEM), and 97 (8.96%) were poor metabolizer (PM). Conclusions. The proposed microarray-based detection has high specificity, sensitivity, and reproducibility for detecting the resistance of clarithromycin or levofloxacin as well as CYP2C19 polymorphism, which may help to improve the clinical eradication rate of H. pylori.

Objective To analyze the drug resistance of Helicobacter pylori (Hp) strains isolated from teenagers (aged 13 to 19) in Xiaoshan area to metronidazole,clarithromycin,levofloxacin,amoxicillin and furazolidone. Methods A retrospective study was conducted on 1 452 teenagers who had endoscopic examination in the First People′s Hospital of Xiaoshan District from January 2012 to December 2017. Statis-tical analysis was performed to analyze the antibiotic resistance of Hp to various antibiotics. Results Teen-agers who were positive for Hp infection accounted for 16.46% (239). The resistance rates of Hp isolates to metronidazole and clarithromycin were 71.55% and 16.74% with an upward trend in the past two years. Among all Hp isolates, those resistant to levofloxacin, amoxicillin and furazolidone accounted for 5.02%, 0.0% and 0.84%,respectively. No significant change in the antibiotic resistance patterns of Hp was ob-served. There were 15.06% of Hp isolates resistant to both metronidazole and clarithromycin. No statistical-ly significant difference in antibiotic resistance patterns was found between Hp isolates from male and female teenagers in Xiaoshan area. Conclusion This study suggested that the Hp isolates showed high resistance to metronidazole,moderate resistance to clarithromycin and levofloxacin,and low resistance to amoxicillin and furazolidone. Attention should be paid to monitoring the antibiotic resistance patterns in teenagers and pro-moting individualized treatment with regard to the eradication strategy of Hp infection.

幽门螺杆菌(Helicobacter pylori,HP)是许多消化道疾病的病因,因此在治疗此类疾病时根除HP 感染具有重要意义?但是,HP 的根除受许多因素影响,其中最主要的原因是细菌的耐药性,因此合理的使用抗生素是根除HP 的重要保证[1-3] ?目前HP 的耐药性检测主要通过药敏试验完成,包括琼脂稀释法和E-Test 法?但是这2 种方法对实验室培养具有较高要求且培养周期较长?

Objective To establish a high-throughput sequencing method for a whole genome in different hepatitis B virus (HBV) concentrations.Methods Two method of amplicon-sequencing and direct sequencing without PCR amplification were used for library construction in the three plasmids,including the low HBV load sample,the moderate HBV load sample and the high HBV load sample.Whole genome sequencing was performed on Illumina MiSeq platform.Results There are significant differences in data yield between the two different library construction method.Only a few reads could be mapped to the HBV genome for direct sequencing.However,three samples were successfully amplified by the nested PCR amplification and amplicon-sequencing showed that all HBV samples had a good coverage and depth,which was not affected by HBV concentration.The alignment rate of HBV genome approached 80％.A total of 27 intra-host single nucleotide variations (iSNVs) were identified and 13 iSNVs were low-frequency mutation in three samples.Compared with the high HBV load sample,mutations in the reverse transcription (RT) region was more easily appeared in the low HBV sample and the moderate HBV load sample.Conclusions Integrating nested PCR with high-throughput sequencing to the HBV whole genome sequencing is not only a practical method to detect the infection of HBV with a high-sensitivity and accuracy,but also enables to detect the mutation in the infected patient with low HBV copy number.

Intracranial infection is one of the most serious complications following neurosurgery. It is well acknowledged that bacteria and fungi are the main pathogens responsible for postoperative intracranial infection. However, the microbial community structure, including composition, abundance and diversity, in postoperative intracranial infection is not fully understood, which greatly compromises our understanding of the necessity and effectiveness of postoperative antibiotic treatment. The present study collected eight cerebrospinal fluid (CSF) samples from patients with intracranial infection following neurosurgical procedures. High-throughput amplicon sequencing for 16S rDNA and internal transcribed spacer (ITS) was performed using the Illumina MiSeq platform to investigate the microbial community composition and diversity between treated and untreated patients. Bioinformatics analysis revealed that the microbial composition and diversity in each patient group (that is, with or without antibiotic treatment) was similar; however, the group receiving antibiotic treatment had a comparatively lower species abundance and diversity compared with untreated patients. At the genus level, Acinetobacter and Staphylococcus were widely distributed in CSF samples from patients with postoperative intracranial infection; in particular, Acinetobacter was detected in all CSF samples. In addition, five ITS fungal libraries were constructed, and Candida was detected in three out of four patients not receiving antibiotic treatment, indicating that the fungal infection should be given more attention. In summary, 16S and ITS high-throughput amplicon sequencing were practical methods to identify pathogens in the different periods of treatment in patients with postoperative intracranial infection. There was a notable difference in microbial composition and diversity between the treated and untreated patients. Alterations in the microbial community structure may provide a signal whether antibiotic treatment worked in postoperative intracranial infection and may assist surgeons to better control the progression of infection.

AIM To investigate alterations in the fecal microbiome using 16S rRNA amplicon sequencing in couples in the same cohabitation environment. METHODS Fecal samples were collected from eight ulcerative colitis (UC) patients and their healthy partners at Lishui People’s Hospital, Zhejiang Province, China. DNA was extracted and the variable regions V3 and V4 of the 16S rRNA genes were PCR amplified using a two-step protocol. Clear reads were clustered into operational taxonomic units (OTUs) at the 97% sequence similarity level using UCLUST v1.2.22. The Wilcoxon rank-sum test (R v3.1.2) was used to compare inter-individual differences. Differences with a P value < 0.05 were considered statistically significant. RESULTS Fecal microbial communities were more similar among UC patients than their healthy partners (P = 0.024). UC individuals had a lower relative abundance of bacteria belonging to the Firmicutes, especially Blautia, Clostridium, Coprococcus and Roseburia (P < 0.05). Microbiota dysbiosis was detected in UC patients and their healthy partners. Relevant genera included Akkermansiam, Bacteroides, Escherichia, Lactobacillales, Klebsiella and Parabacteroides. The enriched pathways in fecal samples of UC patients were related to lipid and nucleotide metabolism. Additionally, the pathways involved in membrane transport and metabolism of cofactors and vitamins were more abundant in the healthy partners. CONCLUSION Our results suggested that the microbial composition might be affected in healthy partners cohabiting with UC patients, especially in terms of microbiota dysbiosis.

Objective To evaluate combined sampling at multiple sites of gastric mucosa for Helicobacter pylori (HP) culture.Methods A total of 258 patients with upper gastrointestinal symptoms received 13C-urea breath test between August 2014 and May 2015.During endoscopy,gastric mucosa biopsy samples from the lesser curvature of the antrum (A),the greater curvature of the antrum (B),gastric angle (C) and the body of the stomach (D) were collected to isolate HP strains.The positive rates of HP based on combined sampling and single site sampling were compared with a Nemenyi test.Results Consistency between 13C-urea breath test and HP culture was 82.56％.There was significant difference between the single site sampling and two-site sampling in the positive rate of HP,except for the body of the stomach (P＜0.05).There was significant difference in the positive rate of HP between the single site sampling and three-site sampling (P ＜ 0.05).There was no significant difference between any two-site sampling in the lesser curvature of the antrum and the body of the stomach,gastric angle and the body of the stomach,the greater curvature of the antrum and the body of the stomach,and any three-site sampling (P＞0.05).Conclusion The combined sampling of the lesser curvature of the antrum and the body of the stomach have the highest cost-effectiveness in HP culture compared with the single site sampling and three-site sampling.

BACKGROUND:To determine the prevalence of resistance to metronidazole, clarithromycin, levofloxacin, amoxicillin, and furazolidone in Helicobacter pylori isolated from Chinese children.MATERIALS AND METHODS:This multicenter retrospective study was conducted from January 2009 to December 2015. A total of 1746 isolates of H. pylori were collected from nine areas of Zhejiang province in the southeast coastal region of China. H. pylori strains were examined for antibiotics susceptibility by agar dilution method.RESULTS:The resistance rates were 75.20% for metronidazole, 16.38% for clarithromycin, 6.70% for levofloxacin, 0.06% for amoxicillin, and 0.06% for furazolidone. The pattern of H. pylori antibiotic resistance demonstrated no significant changes in the rates of resistance to clarithromycin, amoxicillin, furazolidone, and metronidazole over 7 years. A significant trend of increasing resistance to metronidazole was observed as children aged, but a downward trend in clarithromycin resistance was observed as children aged. No difference in the resistance to other antibiotics was observed among different age groups. Also, there was no significant difference between male and female subjects in rates of resistance to these five types of antibiotics. The predominant dual resistance to metronidazole and clarithromycin was presented in 10.65% of the isolates.CONCLUSIONS:The resistance rates of H. pylori in children from southeast coastal region of China were very high to metronidazole, moderate to clarithromycin and levofloxacin, and low to amoxicillin and furazolidone. It is important to continue monitoring the resistance profiles of H. pylori isolated in this region.

目的:调查分析浙江省湖州地区幽门螺杆菌感染及抗生素的耐药情况,为幽门螺杆菌的根除提供理论依据.方法:对浙江省湖州市中心医院收集的13 313例胃镜检查患者的胃黏膜标本进行幽门螺杆菌分离培养,并用平板掺入法对幽门螺杆菌进行药敏试验.结果:13 313例胃黏膜标本中幽门螺杆菌分离培养阳性菌株5170株,阳性率为38.83％.5170株幽门螺杆菌对克拉霉素、左氧氟沙星、甲硝唑的耐药率分别为21.80％、29.32％和94.76％,未发现对阿莫仙、呋喃唑酮、四环素耐药的菌株.5170株幽门螺杆菌对克拉霉素和左氧氟沙星的双重耐药率为11.26％,对克拉霉素、左氧氟沙星和甲硝唑的三重耐药率为10.44％.结论:本地区幽门螺杆菌对克拉霉素、左氧氟沙星和甲硝唑均有非常高的耐药率,应重视菌株的分离培养和耐药性检测,为幽门螺杆菌的根除治疗提供理论依据.

ObjectiveTo study the infection status of Helicobacter pylori(H. pylori)and sensitivity for commonly used antibiotics and provide reference for improvement of eradication rate of HP infection.MethodsFrom March 2012 to February 2014,12834 patients from 6 hospitals in Lishui district underwent gastrointestinal endoscopy. Gastric mucosal specimens were collected and H. pylori strains were isolated and cultured. Resistance tests of all the H. pylori isolates were performed to 6 commonly used antibiotics:levofloxacin,metronidazole,clarithromycin,amoxicillin,gentamicin, and furazolidone with the agar dilution method.Results12834 cases were enrolled in this study and the overall infection rate of Hp was 54.7%. The resistance rate to metronidazole,levofloxacin and clarithromycin were 94.4%,19.76%,16.61% respectively. The resistant rates of amoxicillin, gentamicin and furazolidone were 0%. There were a large number of multi drug resistant strains in these HP clinical isolates. The resistance rates of isolates obtained during 2012 to 2014 were18.56%,7.35%,15.47%,6.92% to levofloxacin and metronidazole,levofloxacina and clarithromycin, metronidazole and clarithromycin,levofloxacin、metronidazole and clarithromycin,respectively.ConclusionThe metronidazole resistance rates have been maintained at a high level of 94.4 %,the rates of resistance to levofloxacin and clarithromycin also have reached a relative high level. The isolates obtained were sensitive to the following three drugs:amoxicillin,gentamicin,and furazolidone. In order to improve the HP eradication rate of currently accepted triple therapy. Amoxicillin,gentamicin and furazolidone should be applied as the preferred antibiotics for the treatment of HP in this area due to sensitivity to HP. Metronidazole should not be applied as the first-line antibiotic due to the higher resistance rate.

AbstractThe antibiotic resistance of Helicobacter pylori (H pylori) is steadily increasing worldwide, resulting in the low efficiency of the current therapeutic approaches for eradication. In this study, we investigated the relationship between antibiotic resistances, the year of sample collection, and the ages of the infected individuals.A total of 29,034 gastric mucosa biopsy samples were randomly collected from January 1, 2009 to December 9, 2014 in Jiaxing City, Zhejiang Province, China. An antibiotic susceptibility testing was determined using an agar-dilution method. The statistical significance was tested using the chi-squared (&khgr;2) test.A total of 9687 strains were isolated. The resistance rate to clarithromycin, levofloxacin, and metronidazole were 17.76%, 19.66%, and 95.5%, respectively. Resistance was rare against amoxicillin, gentamicin, and furazolidone. The metronidazole resistance rate stayed at a consistently high level. In contrast, the resistance rates of clarithromycin and levofloxacin increased rapidly from 2009 to 2011, gradually decreased from 2012 to 2013, and then increased again in 2014. Although patients ages 31 to 50 and 71 to 80 years had lower infection rates of H pylori, they also had higher resistance rates to clarithromycin and levofloxacin. The highest antibiotic resistance rate was observed in patients’ ages 71 to 80 years old. Younger patients (below 30 years old) had a lower resistance to levofloxacin. Patients’ ages 51 to 60 years old may thus represent an important category for the future study of H pylori infection.Age plays a key element in H pylori resistance to clarithromycin and levofloxacin. It is therefore necessary to consider individualized therapy for the optimized treatment of H pylori-infected patients.