Clarithromycin Resistance Rate Research Articles

Characteristics of Helicobacter pylori strains isolated from Mauritanian patients.

Helicobacter pylori (H pylori) is responsible for various diseases including cancer It co-evolved with humans, and human migrations shaped the expansion and the diversity of strains around the world. The risk of developing a disease depends on virulence factors, mainly the cytotoxin-associated gene A protein (CagA). The aim of this study was to determine the cagA status in H pylori strains from Mauritanian patients and to search for a relationship with endoscopic and histologic findings. H pylori was searched in gastric biopsies taken during endoscopy in patients with gastro-duodenal symptoms. RT-PCR was used for the diagnosis and resistance to clarithromycin. The cagA status was determined with PCR and the EPIYA-cagA polymorphism with sequencing. At all, 76/78 (97.4%) biopsies were positive. The rate of clarithromycin resistance was 4/76 (5.26%) due to the A2143G mutation, with a mixed population in 2 cases. The cagA gene was present in 23/76 (30.26%) biopsies, and the EPIYA motif was ABC in 21 (91.3%). High bacterial load and inflammation were significantly associated with cagA-positive status (P<.01). Phylogenetic analysis of the glmM and hspA genes highlighted a mixture of African and European genes in strains of H pylori isolated from patients of Moor origin. We report a high prevalence of H pylori infection in Mauritanian patients, a low rate of clarithromycin resistance (5.26%) and high bacterial load and inflammation associated with cagA-positive status. The phylogenetic analysis highlights the mix of different populations leading to the Moor ethnicity.

High rates of clarithromycin and levofloxacin resistance of Helicobacter pylori in patients with chronic gastritis in the south east area of Vietnam

BackgroundThe increasing rates of clarithromycin (CLR)- and levofloxacin (LVX)-resistant Helicobacter pylori are the main causes of the considerable decrease in the eradication rates of triple therapy and LVX-based regimens. The aims of this study were to determine the rates of CLR- and LVX-resistant H. pylori by the Epsilometer test and to assess the risk factors for this antibiotic resistance among patients with chronic gastritis in the south east area of Vietnam. MethodsGastric biopsy specimens were obtained from 153 patients with H. pylori-positive chronic gastritis for use in culture and in the Epsilometer test to determine CLR and LVX susceptibilities. ResultsThe rates of H. pylori resistance to CLR and LVX were 72.6% and 40.5%, respectively. Dual-resistant H. pylori (to both CLR and LVX) accounted for 30.7% of patients. The rates of high-level resistance to CLR and LVX were 18.9% and 83.9%, respectively. Multivariate analysis showed that age older than 30 years (odds ratio [OR] = 3.80, 95% confidence interval [CI] 1.61–8.97) and history of H. pylori treatment (OR = 8.72, 95% CI 1.90–39.91) were independent risk factors for CLR resistance, whereas only age older than 35 years (OR = 2.42, 95% CI 1.23–4.76) was an independent risk factor for LVX resistance. ConclusionsThese results revealed high rates of resistance of H. pylori to CLR and LVX in patients with chronic gastritis in the south east area of Vietnam. This suggests that CLR-based triple therapy should not be used for the eradication treatment of H. pylori, and LVX susceptibility testing of H. pylori strains should be performed before choosing alternative regimens.

Helicobacter pylori eradication therapy outcome according to clarithromycin susceptibility testing in Japan

Helicobacter pylori (Hp) infection increases the risk of gastric cancer. Therefore, eradication is a global goal, which requires continuous monitoring of therapeutic regimens and effectiveness. Clarithromycin resistance is an important contributor to eradication failure, and metronidazole is recommended as second-line treatment in such cases. Here, we retrospectively evaluated the clarithromycin and metronidazole resistance rates and treatment effectiveness in patients with Hp using tailored therapies according to clarithromycin susceptibility testing. Data on drug susceptibility were obtained for 5249 Japanese Hp patients between July 2005 and August 2018. Clarithromycin/metronidazole resistance rates were analyzed according to year, gender, and age with Fisher's exact test. The relationship between clarithromycin resistance and Hp therapy outcomes was assessed for 1300 patients. Treatment regimens included a clarithromycin- or metronidazole-containing 7-day triple therapy with one of several proton pump inhibitors and vonoprazan. Clarithromycin resistance increased annually and was higher in women and younger patients (<30years). Rates of metronidazole resistance were stable but decreased with age. Hp treatment regimens using PPIs had eradication rates of 88% and 45% among clarithromycin-sensitive and clarithromycin-resistant cases, respectively, while regimens including vonoprazan had eradication rates of around 90% regardless of clarithromycin susceptibility. In particular, triple therapy with vonoprazan, amoxicillin, and metronidazole achieved 98% eradication. Clarithromycin-containing triple therapy even using vonoprazan did not achieve satisfactory eradication rates even in the clarithromycin-sensitive group. To avoid antibiotic misuse in population with low metronidazole resistance, 7-day vonoprazan, amoxicillin, and metronidazole triple therapy might be a strong candidate as a first-line eradication therapy.

Is tailored therapy based on antibiotic susceptibility effective ? a multicenter, open-label, randomized trial.

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.

Helicobacter pylori Infection: Prevalence, Demographic Characteristics, Clarithromycin Resistance and Evaluation of the In-House Rapid Urease Test in Sungai Buloh Hospital, Malaysia

Helicobacter pylori infection remains an essential global research focus, and increasing clarithromycin resistance was reported to impact the efficacy of clarithromycin-based treatment regiments. The study objectives sought to understand the prevalence of H. pylori infection amongst patients from Sungai Buloh Hospital, Malaysia, its association with demographic factors, and the clarithromycin resistance rate. The in-house rapid urease test (IRUT) was also evaluated and compared to the Campylobacter-like organism (CLO) test using culture or histopathological testing as the gold standard for diagnosis. The gastric corpus biopsies of 352 patients were included, as well as their age group, gender and ethnicity. Clarithromycin susceptibility was measured using the E-test method. The overall prevalence of H. pylori infection was 15.1% (53/352). There was no significant association between the age groups, gender and ethnicity with regards to H. pylori infection. Four of the 13 viable isolates (30.8%) were clarithromycin-resistant. Although IRUT had a slightly lower specificity (94.9%) than that of the CLO test (95.9%), both tests had the same sensitivity values (81.1%). IRUT had a lower positive predictive value (74.1%) than the CLO test (78.2%) but showed a similar negative predictive value (96.5%) compared to the CLO test (96.6%). Both tests displayed a very good agreement (κ = 0.97). In conclusion, the overall prevalence of H. pylori infection in our study was generally low. The high proportion of clarithromycin-resistant isolates may not reflect the exact resistance rate due to the small number of positive cultures. Our IRUT is an acceptable alternative to the CLO test for the rapid diagnosis of H. pylori infections based on its comparable performance.

Helicobacter pylori Eradication According to Sequencing-Based 23S Ribosomal RNA Point Mutation Associated with Clarithromycin Resistance.

Background/Aims: Clarithromycin resistance in Helicobacter pylori is associated with point mutations in the 23S ribosomal RNA (rRNA) gene. We investigated the point mutations in the 23S rRNA genes of patients with clarithromycin-resistant H. pylori and compared the H. pylori eradication rates based on the point mutations. Methods: A total of 431 adult patients with H. pylori infection were recruited in Kangdong Sacred Heart Hospital in 2017 and 2018. Patients who did not have point mutations related to clarithromycin resistance and/or had clinically insignificant point mutations were treated with PAC (proton pump inhibitor, amoxicillin, clarithromycin) for seven days, while patients with clinically significant point mutations were treated with PAM (proton pump inhibitor, amoxicillin, metronidazole) for seven days. H. pylori eradication rates were compared. Results: Sequencing-based detection of point mutations identified four mutations that were considered clinically significant (A2142G, A2142C, A2143G, A2143C). The clarithromycin resistance rate was 21.3% in the overall group of patients. A2143G was the most clinically significant point mutation (84/431, 19.5%), while T2182C was the most clinically insignificant point mutation (283/431, 65.7%). The overall H. pylori eradication rate was 83.7%, and the seven-day PAM-treated clarithromycin-resistance group showed a significantly lower eradication rate than the seven-day PAC-treated nonresistance group (ITT; 55.4% (51/92) vs. 74.3% (252/339), p = 0.001, PP; 66.2% (51/77) vs. 88.4% (252/285), p = 0.0001). Conclusions: There were significantly lower eradication rates in the patients with clarithromycin-resistant H. pylori when treated with PAM for seven days. A future study comparing treatment regimens in clarithromycin-resistant H. pylori-infected patients may be necessary.

Characteristics of Helicobacter pylori antibiotic resistance: data from four different populations

AimsTo describe the characteristics of Helicobacter pylori (H. pylori) antibiotic resistance in clinical isolates from four populations.MethodsIn total, 1463 H. pylori strains were examined for antibiotic resistance. Among these strains, 804 were isolated from treatment-naïve adults, 133 from previously treated adults, 100 from treatment-naïve children and 426 from a population who participated in a health survey (age ≥ 40 years). The minimum inhibitory concentration was determined by the E-test method.ResultsIn the treatment-naïve adult group, the resistance rates for metronidazole, clarithromycin, levofloxacin, amoxicillin, rifampicin and tetracycline were 78.4, 19.0, 23.3, 1.2, 1.7 and 2.3%, respectively. Compared with this group, the previously treated adult group had significantly higher resistance rates for metronidazole (99.2%), clarithromycin (58.3%) and levofloxacin (52.3%). In addition, the treatment-naïve children had a lower metronidazole resistance rate (46.0%) than the treatment-naïve adults. The resistance rate for clarithromycin was low in treatment-naïve patients with ages ranging from 10 to 24 years. For the strains isolated from the general population group, the resistance rates for metronidazole, clarithromycin, levofloxacin, amoxicillin, rifampicin and tetracycline were 78.6, 10.1, 25.1, 0.5, 2.1 and 0.9%, respectively. Compared with the treatment-naïve adult group, the general population group showed significant differences in clarithromycin resistance.ConclusionThe resistance rates for metronidazole, clarithromycin and levofloxacin were high, especially in previously treated adults. Compared to those in treatment-naïve younger patients, the resistance rates for clarithromycin were significantly lower in treatment-naïve patients with ages ranging from 10 to 24 years and in the general population.

Analysis of antibiotic resistance and influencing factors for Helicobacter pylori in children

Objective To investigate the antibiotic resistance of Helicobacter pylori(Hp) isolates cultured from endoscopic gastric mucosal samples and influencing factors for antibiotic resistance in children. Methods From April 2013 to February 2016, Hp cultured from mucosa samples of the gastric antrum and the body of stomach was investigated in 246 patients with 13C breath test positive examined by gastroscopy.Resistance to Amoxicillin, Clarithromycin, Metronidazole, Tetracycline was tested for Hp by using E-test.The clinical data were collected from the patients, and the relationship among age, gender, endoscopic diagnosis, histological performance, eradication number factors and antibiotic resistance rate were analyzed. Results Of 246 specimens, 174 cases (70.7%) were positive.The overall antibiotic resistance rates of isolates obtained were 96.55% (168/174 cases), 57.47% (100/174 cases), 4.02% (7/174 cases), 1.15%(2/174 cases) with respect to Clarithromycin, Metronidazole, Tetracycline and Amoxicillin.An antibiotic resistance rate was 43.10% (75/174 strains), among which the Clarithromycin resistance rate was 93.33% (70/75 strains), and the Metronidazole resistance rate was 6.67% (5/75 strains). Double resistance rate was of 54.02%(94/174 strains), among which the resistances rate of Clarithromycin+ Metronidazole was 52.30%(91/94 strains), and the resistances rate of Clarithromycin+ Tetracycline was 1.72%(3/94 strains). Triple resistance rate of Clarithromycin+ Metronidazole+ Tetracycline was 1.15%(2/174 strains). Quadruple resistance rate of Clarithromycin+ Metronidazole+ Amoxicillin+ Tetracycline was 1.15%(2/174 strains). Factor analysis showed that the resistance rate of Clarithromycin in children who had failed in eradication therapy [98.7%(148/150 cases)] was higher than that in children who had not undergone eradication therapy [83.3%(20/24 cases)], and the difference was statistically significant(χ2=14.610, P 0.05). Conclusions Hp resistance rate to Clarithromycin, Metronidazole is very high in children, but it is relatively low to Amoxicillin and Tetracycline, and multiple antibiotic resistance is at high prevalence. Key words: Helicobacter pylori; Antibiotic resistance; Child

1249 National and Regional U.S. Antibiotic Resistance to Helicobacter pylori Identified From a Phase 3 Clinical Trial of Treatment Naïve Patients in the United States

INTRODUCTION: Antibiotic resistance to Helicobacter varies by region. A 2001 report of H. pylori clinical trials noted 10.6% clarithromycin and 21.6% metronidazole resistance nationally. Regional clarithromycin resistance varied from 8.3% in the West to 13.0% in the Northeast and metronidazole resistance ranged from 22.1% in the Northeast to 27.5% in the Southeast. A 2015 Houston VAMC study noted resistance of 16.4% to clarithromycin and 20.3% to metronidazole. A recent clinical study found additional concerns for increasing resistance at both national and regional levels for H. pylori infection. METHODS: Isolates collected in a multi-center clinical trial (2017-2018) from de-identified patients were tested for minimal inhibitory concentrations (MICs) by agar dilution using Clinical and Laboratory Standards Institute (CLSI) methods. CLSI and EUCAST (The European Committee on Antimicrobial Susceptibility Testing) interpretive breakpoints were applied. MICs were obtained for amoxicillin, clarithromycin, metronidazole and rifabutin. Analysis provided resistance patterns for both national and regional levels. RESULTS: MICs were reported for 345 of 356 clinical isolates recovered from treatment-naïve patients at 55 centers (20 states) across the US. The regions were broken down as Northeast, Southeast, South, Central, and West. The MIC90 was 0.125 µg/mL for amoxicillin, 8 µg/mL for clarithromycin, 64 µg/mL for metronidazole, and ≤0.008 µg/mL for rifabutin. Across all US sites, resistance rates were: amoxicillin 6.7%; clarithromycin 17.4%; metronidazole 43.7% and rifabutin 0.0%. Regional assessment of amoxicillin, clarithromycin and metronidazole resistance was: Northeast 0.0% (n = 0), 31.6% (n = 6) and 36.8% (n = 7); Southeast: 6.1% (n = 8), 22.0% (n = 29) and 51.5% (n = 68); South 6.5% (n = 5), 11.7% (n = 9) and 45.5% (n = 35); Central 0.0% (n = 0), 44.4% (n = 4) and 22.2% (n = 2); and West 8.3% (n = 9), 11.1% (n = 12) and 35.5% (n = 38), respectively. CONCLUSION/DISCUSSION: Nationally, we found greater resistance rates for clarithromycin (17.4%) and metronidazole (43.7%) compared to previous reports from 2001 and 2015. Regionally, clarithromycin resistance was greater for the Northeast, Southeast and Central areas while metronidazole resistance was greater than previously reported across all regions. Amoxicillin resistance was low (6.7%: 0%-8.3%), and no resistance to rifabutin was reported. These emerging resistance patterns support the use of rifabutin based therapies for H. pylori eradication.

Primary and secondary antibiotic resistance of Helicobacter pylori in Korea from 2003 to 2018.

Antimicrobial resistance of Helicobacter pylori (Hpylori) affects the efficacy of eradication therapy. The aim of this study was to estimate the prevalence of primary and secondary resistance of Hpylori isolates to antibiotics in Korea. The present study was performed from 2003 to 2018. Primary resistance was evaluated in 591 patients without any history of eradication and secondary resistance in 149 patients from whom Helicobacter pylori was cultured after failure of eradication. A minimal inhibitory concentration test was performed for amoxicillin, clarithromycin, metronidazole, tetracycline, levofloxacin, and rifabutin using the agar dilution method. An increase in the primary resistance rate was found in clarithromycin (P<.001), metronidazole (P<.001), and both levofloxacin (P<.001) during the study period. The primary resistance rates of amoxicillin and tetracycline were low and stable during the study period. The secondary resistance rate significantly increased in metronidazole and levofloxacin (P=.022 and .039, respectively). The primary and secondary resistance rates of clarithromycin, metronidazole, and levofloxacin for Helicobacter pylori in Korea were high and increased over time. However, the primary and secondary resistance rates of amoxicillin and tetracycline were low and stable over time. These results will help in selecting effective eradication regimens of Hpylori in Korea in the future.

Increasing antimicrobial resistance to clarithromycin and metronidazole in pediatric Helicobacter pylori infection in southern Taiwan: A comparison between two decades.

Antimicrobial resistance of Helicobacter pylori reduces the eradication rate. This study aimed to investigate changes in antimicrobial susceptibility of Hpylori isolated from children in Taiwan in the past two decades. This study enrolled children receiving esophagogastroduodenoscopy for upper gastrointestinal diseases in a national tertiary referring hospital from 1998 to 2018. Hpylori infection was diagnosed by culture. The minimal inhibitory concentrations (MICs) of antibiotics were tested using the E test. The antibiotic resistance rates and MICs of amoxicillin, clarithromycin, metronidazole, levofloxacin, and tetracycline were compared between 1998-2008 and 2009-2018. A total of 70 Helicobacter pylori isolates (29 from 1998 to 2008 and 41 from 2009 to 2018) were identified. The esophagogastroduodenoscopy findings included duodenal ulcers (n=31), gastric ulcers (n=9), and gastritis (n=30). The overall antimicrobial resistance rates of clarithromycin and metronidazole were 22.9% and 21.4%, respectively. The dual resistance rate of clarithromycin and metronidazole was 10%. Resistance rates of levofloxacin and amoxicillin were 8.3% and 2.9%, respectively. None of the isolates were resistant to tetracycline. Compared with the isolates from 1998 to 2008, those from 2009 to 2018 had higher MICs and resistance rates of clarithromycin (26.8% vs 17.2%, P=0.35) and metronidazole (26.8% vs 13.8%, P=0.19), but not levofloxacin (9.8% vs 5.3%, P=1.0) or coresistance to clarithromycin and metronidazole (12.2% vs 6.9%, P=0.69). The antimicrobial resistance rates of pediatric Hpylori isolates to clarithromycin and metronidazole increased during the past decade. The selection of antimicrobial agents other than clarithromycin and metronidazole is crucial to increase pediatric Hpylori eradication rates.

The antibiotic resistance of Helicobacter pylori to five antibiotics and influencing factors in an area of China with a high risk of gastric cancer

BackgroundH. pylori exhibits antibiotic resistance with regional differences. In this paper, we explored antibiotic resistance of H. pylori to five antibiotics in an area with a high risk of gastric cancer.ResultsH. pylori resistance rates to metronidazole, levofloxacin, clarithromycin, amoxicillin, and tetracycline were 78.0, 56.0, 31.0, 9.0, and 15.0%, respectively. Double, triple, quadruple, and quintuple resistance rates were 23, 20, 6, and 4%, respectively. The clarithromycin and multidrug resistance rates were significantly higher in males than females (clarithromycin: 44.4% vs 15.2%, respectively, P = 0.002; multidrug: 75.5% vs 37.2%, respectively; P < 0.001). During the three periods of 1998–1999, 2002–2004 and 2016–2017, the resistance rates to levofloxacin and amoxicillin were increasing (OR: 2.089, 95%CI: 1.142–3.821, P = 0.017; and OR: 5.035, 95%CI: 1.327–19.105, P = 0.018, respectively). The antibiotic resistance rates were unassociated with the host disease state. Metronidazole resistance was lower in the vacAs1m1/m2 group than the vacAs1m1m2 group (65% vs 85.7%, respectively; P = 0.026). As for levofloxacin resistance, it was higher with cagA+ than cagA− (60.9% vs 23.1%, respectively; P = 0.020) but lower with slyD+ than slyD− (41.4% vs 68.5%, respectively; P = 0.009). Clarithromycin had a lower resistance rate with iceA++ than iceA−+ (19.7% vs 52.4%, respectively; P = 0.017). For amoxicillin, the iceA++ group had a lower resistance rate than the iceA−− group (1.6% vs 27.8%, respectively; P = 0.009).ConclusionsThe total resistance rates of H. pylori to metronidazole, levofloxacin, clarithromycin, amoxicillin, and tetracycline were high in Zhuanghe. The resistanc rates to levofloxacin and amoxicillin increased over time. Clarithromycin resistance was associated with male and iceA. The resistance of metronidazole was related to vacA. Levofloxacin resistance was concerned with cagA and slyD and amoxicillin resistance was concerned with iceA. While, the antibiotic resistance of H. pylori had nothing to do with the status of gastric disease.

Drug resistance and pathogenic spectrum of patients coinfected with nontuberculous mycobacteria and human-immunodeficiency virus in Chengdu, China.

Background:Human-immunodeficiency virus (HIV) infection is increasing worldwide and nontuberculous mycobacteria (NTM) is an established microbiologic cause of pulmonary disease, lymphadenitis, and disseminated disease in cases of advanced immune suppression. Data on patients coinfected with HIV and NTM are limited. Thus, this study aimed to analyze the clinical characteristics, drug resistance, and pathogen spectrum of patients coinfected with both HIV and NTM in the Chengdu area of China.Methods:Data of 59 patients coinfected with both HIV and NTM collected from the Public Health Clinical Center of Chengdu, between January 2014 and December 2018, were analyzed. NTM drug sensitivity testing was performed using the microporous plate ratio method. Data were analyzed using SPSS 19.0, and the change in drug resistance rate was analyzed using the chi-square (χ2) test.Results:Seven species/complex of NTM were identified from patients coinfected with HIV and NTM in this study, with Mycobacterium avium–intracellulare complex (52.5%) and M. kansasii (27.1%) as the predominant species. Male patients were more affected 50/59 (84.7%); the mean age of the 59 cases was 45 years. The clinical characteristics mainly included anemia (86.4%), cough and expectoration (79.7%). The baseline CD4 count was <50 cells/μL (84.7%). Patients were mainly in advanced acquired immunodeficiency syndrome (AIDS) stage. Chest imaging mainly showed patchy shadows (42.4%) and nodules (32.2%), with various degrees of AIDS-defining diseases. The drug resistance of NTM was severe, and the rate of isoniazid resistance (100.0%) was the highest, followed by rifampicin (94.9%), streptomycin (94.9%), ofloxacin (93.2%), and others. Ethambutol (52.5%) and clarithromycin (33.9%) were relatively low. No significant difference was found in the drug resistance rate of NTM strain against nine antituberculosis drugs in 5 years (P > 0.05).Conclusions:The immune level of patients coinfected with HIV and NTM is low in advanced AIDS stage; more male are affected in patients who are mainly infected with MAC and M. kansasii and with serious drug resistance. The drug resistance rate of ethambutol and clarithromycin is relatively low.

Management of Antibiotic-Resistant Helicobacter pylori Infection: Perspectives from Vietnam.

Antibiotic resistance is the most important factor leading to the failure of eradication regimens. This review focuses on the prevalence of Helicobacter pylori primary and secondary resistance to clarithromycin, metronidazole, amoxicillin, levofloxacin, tetracycline, and multidrug in Vietnam. We searched the PubMed, EMBASE, Vietnamese National Knowledge Infrastructure, and Vietnamese Biomedical databases from January 2000 to December 2016. The search terms included the following: H. pylori infection, antibiotic (including clarithromycin, metronidazole, amoxicillin, levofloxacin, tetracycline, and multidrug) resistance in Vietnam. The data were summarized in an extraction table and analyzed manually. Finally, Excel 2007 software was used to create charts. Ten studies (three studies in English and seven in Vietnamese) were included in this review. A total of 308, 412, 523, 408, 399, and 268 H. pylori strains were included in this review to evaluate the prevalence of H. pylori primary resistance to amoxicillin, clarithromycin, metronidazole, levofloxacin, tetracycline, and multidrug resistance, respectively. Overall, the primary resistance rates of amoxicillin, clarithromycin, metronidazole, levofloxacin, tetracycline, and multidrug resistance were 15.0%, 34.1%, 69.4%, 27.9%, 17.9% and 48.8%, respectively. Secondary resistance rates of amoxicillin, clarithromycin, metronidazole, levofloxacin, tetracycline, and multidrug resistance were 9.5%, 74.9%, 61.5%, 45.7%, 23.5% and 62.3%, respectively. In Vietnam, primary and secondary resistance to H. pylori is increasing over time and affects the effectiveness of H. pylori eradication.

Vonoprazan and Helicobacter pylori Treatment: A Lesson From Japan or a Limited Geographic Phenomenon?

Within a short time after the discovery of Helicobacter pylori, its critical role in many gastroduodenal disorders became evident. Many in vitro and in vivo data have proven that infection should be treated in order to avoid lasting colonization which may lead to problematic gastroduodenal diseases. Probiotics, preventive and therapeutic vaccines and antibiotic therapy are the main options proposed to cure these disorders. 25 years ago, triple therapy including a traditional proton pump inhibitor (PPI) and two antibiotics (amoxicillin and clarithromycin or metronidazole) was defined as the best therapy formulation for the H. pylori infection. With the strongly decreased effectiveness of this scheme, many empirical therapeutic regimens have been developed. However, the prevalence of resistance is increasing worldwide and reveals important geographic differences and even the most recent and effective regimens show some critical points. Therefore, efficacy of vonoprazan-based therapy in regions with low rate of clarithromycin resistance may be limited. In this review, we attempt to open a new window to overcome the problem of antibiotic resistance to H. pylori. In fact, we focused our attention on the possibility that conventional PPI may be replaced by vonoprazan, thus giving rise to the beginning of a new era characterized by an improved therapeutic option for H. pylori infection. Therefore, we hypothesize that switching to vonoprazan as a novel acid blocker for H. pylori treatment might allow an unexpected reassessment of the triple therapy, at least in regions with low rate of clarithromycin resistance. Nevertheless, this optimistic view of the problem could be disproved by the possible failure of vonoprazan based therapeutic regimens outside of Japan in geographic areas characterized by different rates of antibiotic resistances.

Rates of clarithromycin resistance in Helicobacter pylori sampled from healthy subjects in Cheonan, Korea

Rates of clarithromycin resistance in Helicobacter pylori sampled from healthy subjects in Cheonan, Korea

Can Aminoglycosides Be Used as a New Treatment for Helicobacter pylori? In vitro Activity of Recently Isolated Helicobacter pylori.

BackgroundSmectite can serve as a drug delivery system and gentamicin-intercalated smectite hybrids are expected to supersede the standard therapy for Helicobacter pylori eradication. The aim of this study was to confirm whether the minimum inhibitory concentration (MIC) of aminoglycosides applied as smectite hybrids remained low against recently isolated H. pylori strains.Materials and MethodsA total of 140 strains were collected for a minimum period of 3 years. Antimicrobial susceptibility tests were performed, and the MICs of eight antibiotics (amoxicillin, clarithromycin, metronidazole, tetracycline, levofloxacin, gentamicin, netilmicin, and tobramycin) were determined by using the Epsilometer test and following the European Committee on Antimicrobial Susceptibility Testing recommendations.ResultsThe resistance rate of clarithromycin was high, up to 30.7%, although it is a major antimicrobial agent used in standard therapy. The MIC50 and MIC90 of gentamicin (0.25 mg/L and 0.75 mg/L) and netilmicin (0.19 mg/L and 0.75 mg/L) were lower than other alternative therapies for H. pylori eradication. In clarithromycin-resistant strains, the MIC50 was 0.25 mg/L and the MIC90 was 1 mg/L for gentamicin; for netilmicin, the values were 0.25 mg/L and 0.75 mg/L, respectively.ConclusionThrough the use of gentamicin and netilmicin, which have low MICs for H. pylori, aminoglycoside-intercalated smectite hybrids are expected to emerge as a new standard therapy for H. pylori eradication.

Alternative eradication regimens for Helicobacter pylori infection in Indonesian regions with high metronidazole and levofloxacin resistance.

BackgroundThe prevalence of Helicobacter pylori resistance to metronidazole and clarithromycin is high in Indonesia. Moreover, the increasing levofloxacin resistance rates in the absence of bismuth treatment in Indonesia has led to the use of other antibiotics as alternative regimens.MethodsWe determined the minimum inhibitory concentrations (MICs) of five alternative antibiotics for H. pylori (rifaximin, rifabutin, furazolidone, garenoxacin, and sitafloxacin) using the agar dilution method and assessed mutations associated with antibiotic resistance using next-generation sequencing.ResultAnalysis of 106 strains isolated from 1039 adult dyspeptic patients revealed that none of the strains were furazolidone-resistant. All strains were also sensitive to rifabutin and sitafloxacin. In contrast, the rates of resistance to rifaximin and garenoxacin were high (38.9% and 6.7%, respectively). The strains isolated from patients on Java Island had the highest resistance rates to garenoxacin and rifaximin. In addition, the resistance was distributed evenly among the ethnic groups, ranging between 25.0% and 69.2%. Except for rifaximin, for which the resistance rate was 38.9%, the other four antibiotics could be successfully employed to eradicate levofloxacin- and metronidazole-resistant H. pylori infections in vitro. Interestingly, garenoxacin-sensitive strains were found in regions with high clarithromycin resistance rates such as Bali and Papua Islands. In contrast, rifaximin might not be considered as an alternative antibiotic in regions with high clarithromycin resistance. There was an inconsistent association between gyrA and gyrB mutations and garenoxacin resistance. We confirmed that the I837V (replacement of isoleucine at position 837 with valine), A2414T/V, Q2079K and K2068R were the predominant rpoB point mutations. There was an association between vacA genotypes of H. pylori and rifaximin resistance (P = 0.048).Conclusionfurazolidone-, rifabutin-, and sitafloxacin-based therapies might be considered as alternative regimens to eradicate H. pylori in Indonesia, including regions with high metronidazole and clarithromycin resistance rates. Moreover, sitafloxacin but not garenoxacin should be considered for eradication of levofloxacin-resistant strains.

Helicobacter pylori resistance to current therapies.

Helicobacter pylori eradication rates have fallen in recent years, mainly because of the emergence of antibiotic-resistant infections. Indeed the WHO has recently designated clarithromycin-resistant H. pylori infection a high priority for antibiotic resistance research and development. This review aims to discuss the most up-to-date information on the methods to detect H. pylori antibiotic resistance, the recent data on resistance rates, and the most appropriate treatment strategies to overcome antibiotic resistance. There has been active research into the development and assessment of genotypic diagnostic assays for both the invasive and noninvasive detection of antibiotic-resistant infection. There are regional variations in the prevalence of H. pylori antibiotic resistance. Primary resistance rates in general are on the rise and high rates of clarithromycin resistance (>15%) have been reported in many parts of the world. Optimizing antimicrobial susceptibility testing by both invasive and noninvasive means is crucial to accurately evaluate resistance rates for the optimization of both regional and personalized H. pylori treatment strategies.

RELATIONSHIP BETWEEN IN VITRO CLARITHROMYCIN SUSCEPTIBILITY AND SPUTUM CULTURE CONVERSION WITH ADD-ON AMIKACIN LIPOSOME INHALATION SUSPENSION (ALIS) FOR TREATMENT OF REFRACTORY MYCOBACTERIUM AVIUM COMPLEX (MAC) LUNG DISEASE

RELATIONSHIP BETWEEN IN VITRO CLARITHROMYCIN SUSCEPTIBILITY AND SPUTUM CULTURE CONVERSION WITH ADD-ON AMIKACIN LIPOSOME INHALATION SUSPENSION (ALIS) FOR TREATMENT OF REFRACTORY MYCOBACTERIUM AVIUM COMPLEX (MAC) LUNG DISEASE