scholarly journals Microarray-Based Detection and Clinical Evaluation for Helicobacter pylori Resistance to Clarithromycin or Levofloxacin and the Genotype of CYP2C19 in 1083 Patients

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Yi Song ◽  
Fengna Dou ◽  
Zhe Zhou ◽  
Ningmin Yang ◽  
Jing Zhong ◽  
...  

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.

2014 ◽  
Vol 63 (5) ◽  
pp. 703-709 ◽  
Author(s):  
Hanafiah Alfizah ◽  
Ahmad Norazah ◽  
Razlan Hamizah ◽  
Mohamed Ramelah

Antibiotic resistance is increasing worldwide, and it has been regarded as the main factor reducing the efficacy of Helicobacter pylori therapy. The aim of this study was to determine the phenotype and genotype of antibiotic-resistant strains of H. pylori in the Malaysian population and to evaluate the impact of antibiotic resistance to eradication outcome. One hundred and sixty-one H. pylori isolates were analysed in this study. Metronidazole, clarithromycin, fluoroquinolone, amoxicillin and tetracycline susceptibilities were determined by Etest. PCR followed by DNA sequencing was carried out to determine mutations. The medical records of the patients infected with resistant strains were reviewed to determine the eradication outcome. Metronidazole resistance was encountered in 36.6 % of H. pylori isolates, whereas clarithromycin and fluoroquinolone resistance was observed in 1.2  and 1.9 % of isolates, respectively. All strains tested were susceptible to amoxicillin and tetracycline. Frameshift and nonsense mutations in rdxA and frxA genes resulting in stop codons contributed to metronidazole resistance, which leads to reduced eradication efficacy. A2142G and A2143G mutations of 23S rRNA were identified as causing failure of the eradication therapy. Mutation at either codon 87 or 91 of the gyrA gene was identified in fluoroquinolone-resistant strains. However, the effect of resistance could not be assessed. This study showed that frameshift and nonsense mutations in rdxA or frxA genes and point mutations in the 23S rRNA affected the efficacy of H. pylori eradication therapy.


2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Lili Yang ◽  
Ao Zou ◽  
Huihua Wu ◽  
Hai Guo ◽  
Fangting Zhang ◽  
...  

Background. Helicobacter pylori eradication with therapies employing a proton pump inhibitor (PPI) and antimicrobial agents is mainly achieved via bacterial susceptibility to antimicrobial agents and the magnitude of acid secretion inhibition. However, annual eradication rates have greatly declined in Mainland China, and therefore, tailored H. pylori eradication regimens that inhibit acid secretion and employ optimal antimicrobial agents determined based on gene clip testing may improve eradication rates. This study was aimed at evaluating the efficacy of tailored H. pylori eradication therapy guided by visual gene clip testing for antibiotic resistance and PPI metabolism genotypes. Methods. This prospective study included 244 patients (141 men and 103 women aged 20–79 years) receiving initial treatment for H. pylori infection. Visual gene clip testing using gastric mucosal specimens was performed to detect antibiotic resistance to clarithromycin conferred by the A2142G and A2143G point mutations of the H. pylori 23S rRNA gene and to levofloxacin conferred by the Asn87 and Asp91 point mutations of the H. pylori gyrA gene. Patients received a 14-day bismuth quadruple therapy regimen guided by testing for antibiotic resistance and CYP2C19 polymorphisms, and primary H. pylori eradication was assessed at least 4 weeks after therapy. Results. H. pylori strains were successfully isolated from the gastric mucosa tissues of 244 patients. Antibiotic resistant isolates were identified in 63 patients, with clarithromycin resistance observed in 50 patients, levofloxacin resistance in 7 patients, and dual resistance in 6 patients. The PPI metabolic genotype of CYP2C19 was detected in 242 of 244 cases, and 97 cases were categorized as extensive metabolizers, 141 as intermediate metabolizers, and 4 as poor metabolizers. Among the 242 patients who received tailored therapy, the H. pylori eradication rate was 90.9% (95% confidence interval 87.3%~94.6%) in the intention-to-treat analysis and 96.9% (95% confidence interval 94.7%~99.2%) in the per protocol analysis. Conclusions. Tailored therapy for H. pylori infection guided by determination of antibiotic resistance and CYP2C19 polymorphism using visual gene chip technology may provide high clinical effectiveness as initial H. pylori eradication therapy.


2019 ◽  
Vol 8 (6) ◽  
pp. 858 ◽  
Author(s):  
Vo Phuoc Tuan ◽  
Dou Narith ◽  
Evariste Tshibangu-Kabamba ◽  
Ho Dang Quy Dung ◽  
Pham Thanh Viet ◽  
...  

We evaluated the primary resistance of Helicobacter pylori (H. pylori) to routinely used antibiotics in Cambodia, an unexplored topic in the country, and assessed next-generation sequencing’s (NGS) potential to discover genetic resistance determinants. Fifty-five H. pylori strains were successfully cultured and screened for antibiotic susceptibility using agar dilution. Genotypic analysis was performed using NGS data with a CLC genomic workbench. PlasmidSeeker was used to detect plasmids. The correlation between resistant genotypes and phenotypes was evaluated statistically. Resistances to metronidazole (MTZ), levofloxacin (LVX), clarithromycin (CLR), and amoxicillin (AMX) were 96.4%, 67.3%, 25.5%, and 9.1%, respectively. No resistance to tetracycline (TET) was observed. Multi-drug resistance affected 76.4% of strains. No plasmids were found, but genetic determinants of resistance to CLR, LVX, and AMX were 23S rRNA (A2146G and A2147G), GyrA (N87K and D91Y/N/G), and pbp1 (P473L), respectively. No determinants were genetically linked to MTZ or TET resistance. There was high concordance between resistant genotypes and phenotypes for AMX, LVX, and CLR. We observed high antibiotic resistance rates of CLR, MTZ, and LVX, emphasizing the need for periodic evaluation and alternative therapies in Cambodia. NGS showed high capability for detecting genetic resistance determinants and potential for implementation in local treatment policies.


2019 ◽  
Vol 56 (4) ◽  
pp. 361-366
Author(s):  
Cristian PARRA-SEPÚLVEDA ◽  
José S MERINO ◽  
Katia SÁEZ-CARRILLO ◽  
Carlos GONZÁLEZ ◽  
Apolinaria GARCÍA-CANCINO

ABSTRACT BACKGROUND: Helicobacter pylori infection in Chile remains as a public and private health-care system’s challenge, with a prevalence of the infection over 70%. Nowadays, antibiotic treatment of the infection is mandatory to prevent the arising of severe associated diseases but failures in the eradication therapy mainly due to clarithromycin resistance has been observed worldwide and first line eradication therapy seems to be not effective anymore in several geographical areas. Thus, health-care systems are committed to maintain an epidemiological surveillance upon the evolution of the antibiotic resistance of this priority 2 pathogen. OBJECTIVE: This work reports a 10 years surveillance of the primary antibiotic resistance of H. pylori clinical isolates at the Biobío region-Chile, and the evolution of resistance toward amoxicillin, clarithromycin, levofloxacin, metronidazole, and tetracycline among the species. METHODS: H. pylori strains were investigated during the periods 2005-2007 (1435 patients analysed) and 2015-2017 (220 patients analysed) by inoculating a saline homogenate biopsy onto the surface of Columbia agar (Oxoid, Basingstoke, UK) - supplemented with 7% horse red blood cells plus DENT inhibitor (Oxoid, Basingstoke, UK) - following by incubation at 37ºC under 10% CO2 atmosphere for five days. Antibiotic resistance pattern of the isolates was assessed using the disk diffusion test in Müeller-Hinton agar supplemented with 7% horse red blood cells followed by incubation for further three days under 10% CO2 atmosphere. Statistical analysis was done using the SPSS v22 software and P values <0.05 were considered statistically significant. RESULTS: A total of 41% of 1435 patients were detected to be infected with H. pylori by bacteriological culture in 2005-2007 period, meanwhile 32.7% from 220 patients were also infected in 2015-2017 period. The clinical isolates of H. pylori are mostly susceptible to amoxicillin and tetracycline (both over 98% of strains), but less susceptible to levofloxacin in both periods analysed (over 79% of the strains). On the other hand, metronidazole continuous showing the highest score of resistant isolates (over 40% of resistant strains), although an 18% fewer resistant strains were observed in 2015-2017 period. Clarithromycin, the key antibiotic in eradication therapies, has an increased frequency of resistant strain isolated in the decade (22.5% in 2005-2007 and 29.2% in 2015-2017). Multidrug resistant strains (two, three and four antibiotics) were also detected in both periods with the highest scores for simultaneous resistance to clarithromycin-metronidazole (18%) and clarithromycin-metronidazole-levofloxacin (12.5%) resistant strains. According to gender, the isolates resistant to amoxicillin, clarithromycin and metronidazole were more frequent in female, with a specific increment in amoxicillin and clarithromycin resistance. CONCLUSION: The frequency of clarithromycin resistance (29.2%) detected in 2015-2017 suggests that conventional triple therapy is no longer effective in this region.


2018 ◽  
Vol 72 ◽  
pp. 143-158
Author(s):  
Eliza Mnich ◽  
Jakub Ibran ◽  
Magdalena Chmiela

The aim of this study was to present the risks associated with the occurrence of Helicobacter pylori (H. pylori) infection in humans and the problems related to eradication procedures with the use of antibiotic treatment. The content provides an overview of the available methods of infection diagnosis and recommended therapeutic schemes as well as potential alternative schedules of treatment. Mechanisms of H. pylori resistance to commonly used antibiotics including the mutations in the genome leading to resistance and the incidence of resistant strains in the world has been described. Finally, we introduced substances with some potential in eradication therapy, including probiotics, plant formulations as well as polyunsaturated fatty acids and ascorbic acid.


2020 ◽  
Vol 13 ◽  
pp. 175628482097699
Author(s):  
Chih-Ming Liang ◽  
Wei-Chen Tai ◽  
Pin-I Hsu ◽  
Deng-Chyang Wu ◽  
Chao-Hung Kuo ◽  
...  

Background: Antibiotic resistance plays a crucial role in the treatment failure of Helicobacter pylori (H. pylori) infection. This study aimed to determine the trend of changes in the primary, secondary and tertiary antibiotic resistance of H. pylori in Taiwan over the last 7 years. Methods: We retrospectively analysed H. pylori-infected isolates from patients with primary resistance ( n = 1369), secondary resistance ( n = 196) and tertiary resistance ( n = 184) from January 2013 to December 2019. The H. pylori strains were tested for susceptibility to amoxicillin, clarithromycin, levofloxacin, metronidazole and tetracycline using the Epsilometer test method. Results: A progressively higher primary resistance rate was observed for clarithromycin (11.8–20.4%, p = 0.039 in χ2 test for linear trend), levofloxacin (17.3–38.8%, p < 0.001) and metronidazole (25.6–42.3%, p < 0.001) among naïve patients who received first-line eradication therapy. The dual primary resistance to clarithromycin and metronidazole also progressively increased in a linear trend (2.4–10.4%, p = 0.009). For secondary resistance, an increase was observed for levofloxacin (30.5–64.7%, p = 0.006) and metronidazole (40.5–77.4%, p < 0.001). For tertiary resistance, the observed increase was even more significant for levofloxacin (65.9–100.0%, p = 0.106) and metronidazole (44.4–88.2%, p < 0.001). The resistance to amoxicillin and tetracycline remained very low in Taiwan regardless of primary, secondary and tertiary resistance. Conclusion: Primary, secondary and tertiary antibiotic resistance to clarithromycin, levofloxacin and metronidazole for H. pylori has been increasing in Taiwan since 2013. Treatment should be targeted for eradication success rates of more than 90%. Third-line treatment should be based on antibiotic susceptibility.


2019 ◽  
Vol 8 (11) ◽  
pp. 2004 ◽  
Author(s):  
Nastaran Farzi ◽  
Abbas Yadegar ◽  
Amir Sadeghi ◽  
Hamid Asadzadeh Aghdaei ◽  
Sinéad Marian Smith ◽  
...  

The high prevalence of antibiotic resistance in Helicobacter pylori has become a great challenge in Iran. The genetic mutations that contribute to the resistance have yet to be precisely identified. This study aimed to investigate the prevalence of antibiotic resistance and virulence markers in Iranian H. pylori isolates and to analyze if there is any association between resistance and genotype. Antibiotic susceptibility patterns of 68 H. pylori isolates were investigated against metronidazole, clarithromycin, amoxicillin, rifampicin, ciprofloxacin, levofloxacin, and tetracycline by the agar dilution method. The frxA, rdxA, gyrA, gyrB, and 23S rRNA genes of the isolates were sequenced. The virulence genotypes were also determined using PCR. Metronidazole resistance was present in 82.4% of the isolates, followed by clarithromycin (33.8%), ciprofloxacin (33.8%), rifampicin (32.4%), amoxicillin (30.9%), levofloxacin (27.9%), and tetracycline (4.4%). Overall, 75% of the isolates were resistant to at least two antibiotics tested and considered as a multidrug resistance (MDR) phenotype. Most of the metronidazole-resistant isolates carried frameshift mutations in both frxA and rdxA genes, and premature termination occurred in positions Q5Stop and Q50Stop, respectively. Amino acid substitutions M191I, G208E, and V199A were predominantly found in gyrA gene of fluoroquinolone-resistant isolates. A2143G and C2195T mutations of 23S rRNA were found in four clarithromycin-resistant isolates. Interestingly, significant associations were found between resistance to metronidazole (MNZ) and cagA-, sabA-, and dupA-positive genotypes, with p = 0.0002, p = 0.0001, and p = 0.0001, respectively. Furthermore, a significant association was found between oipA “on” status and resistance to amoxicillin (AMX) (p = 0.02). The prevalence of H. pylori antibiotic resistance is high in our region, particularly that of metronidazole, clarithromycin, ciprofloxacin, and MDR. Simultaneous screening of virulence and resistance genotypes can help clinicians to choose the appropriate therapeutic regime against H. pylori infection.


1998 ◽  
Vol 12 (4) ◽  
pp. 295-298 ◽  
Author(s):  
Diane E Taylor ◽  
Qin Jiang ◽  
Richard N Fedorak

The incidence of antibiotic resistance to amoxicillin, clarithromycin, erythromycin, metronidazole and tetracycline inHelicobacter pyloristrains isolated from gastric biopsy specimens obtained in Alberta was investigated. Results for all antibiotics were obtained using agar dilution, and in addition to metronidazole, the E test was used. Resistance to amoxicillin and tetracycline was not detected. Metronidazole resistance determined using agar dilution was approximately 12% (95% CI 4% to 26%) when minimal inhibitory concentrations (MICs) were at least 8 µg/mL, but fell to 2% (95% CI 0.1% to 13%) when MICs were set at 32 µg/mL or greater. The E test for metronidazole resistance (MIC 8 µg/mL or greater) yielded a slightly higher percentage of resistant strains compared with agar dilution tests (14%, 95% CI 5% to 29%). One of the 31 strains was resistant to clarithromycin (MIC 8 µg/mL) and erythromycin (MIC 16 µg/mL). Thus, the incidence of resistance to clarithromycin, part of the currently used triple therapy for eradication ofH pylori, was 3% (95% CI 0.1% to 17%).


2013 ◽  
Vol 47 (3) ◽  
pp. 258-265 ◽  
Author(s):  
Miha Skvarc ◽  
David Stubljar ◽  
Andreja Natasa Kopitar ◽  
Samo Jeverica ◽  
Bojan Tepes ◽  
...  

Abstract Background. The immune response to Helicobacter pylori importantly determines the outcome of infection as well as the success of eradication therapy. We demonstrate the role of a cysteine protease cathepsin X in the immune response to H. pylori infection. Materials and methods. We analysed how the inhibition of cathepsin X influenced the immune response in experiments when THP-1 cells or dendritic cells isolated from patients were stimulated with 48 strains of H. pylori isolated from gastric biopsy samples of patients which had problems with the eradication of bacteria. Results. The experiments, performed with the help of a flow cytometer, showed that the expression of Toll-like receptors (TLRs), especially TLR-4 molecules, on the membranes of THP-1 cells or dendritic cells was higher when we stimulated cells with H. pylori together with inhibitor of cathepsin X 2F12 compared to THP-1 cells or dendritic cells stimulated with H. pylori only, and also in comparison with negative control samples. We also demonstrated that when we inhibited the action of cathepsin X in THP-1 cells, the concentrations of pro-inflammatory cytokines were lower than when THP-1 cell were stimulated with H. pylori only. Conclusions. We demonstrated that inhibition of cathepsin X influences the internalization of TLR-2 and TLR-4. TLR-2 and TLR-4 redistribution to intra-cytoplasmic compartments is hampered if cathepsin X is blocked. The beginning of a successful immune response against H. pylori in the case of inhibition of cathepsin X is delayed.


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