Primary Resistance Rates Research Articles

Vonoprazan Dual or Triple Therapy Versus Bismuth-Quadruple Therapy as First-Line Therapy for Helicobacter pylori Infection: A Three-Arm, Randomized Clinical Trial.

We compared efficacy of vonoprazan-dual or triple therapies and bismuth-quadruple therapy for treatment-naive Helicobacter pylori (HP) infection in Southern China, where primary resistance rates of clarithromycin and levofloxacin are >30%. This was an investigator-initiated, three-arm, randomized clinical trial in Southern China. Between March 2022 and August 2023, treatment-naïve HP-infected adults were randomly assigned to receive one of three 14-day regimens (1:1:1 ratio): vonoprazan-dual (VA-dual; vonoprazan 20 mg twice daily and amoxicillin 1 g thrice daily), vonoprazan-triple (VAC-triple; vonoprazan 20 mg/amoxicillin 1 g/clarithromycin 500 mg twice daily), or bismuth-quadruple therapy containing bismuth, esomeprazole, tetracycline, and metronidazole. Primary outcome was noninferiority in HP eradication, evaluated by UBT 4-6 weeks post-treatment by intention-to-treat (ITT) and per-protocol (PP) analysis (based on subjects who completed 14-day treatment and rechecked UBT). Bonferroni-adjusted p-value of <0.017 was used to determine statistical significance. A total of 298 subjects (mean age: 35.7 ± 8.4 years; male: 134 [45.0%]; VC-dual: 100, VAC-triple: 98, bismuth-quadruple: 100) were enrolled, and 292 (98.0%) had UBT rechecked. ITT analysis showed that both VA-dual (eradication rate of 96.0%) and VAC-triple therapies (95.9%) were noninferior to bismuth-quadruple therapy (92.0%) (difference: 4.0%, 95% CI: -2.9% to 11.5%, p < 0.001; and 3.9%, 95% CI: -3.1% to 11.5%, p < 0.001, respectively). PP analysis also revealed noninferiority (96.7% or 96.7% vs. 97.4%, with difference: -2.9% and -2.9%, p = 0.009 and 0.010, respectively). The frequency of adverse events was 39.0%, 56.1%, and 71.0% in VA-dual, VAC-triple, and bismuth-quadruple therapies, respectively. VA-dual and VA-triple therapies are highly effective and noninferior to bismuth-quadruple therapy in Southern China. Given the lower adverse effects and fewer antibiotic use, VA-dual therapy is the preferred first-line treatment for HP infection. Chinese Clinical Trial Registry (No. ChiCTR2200056375). Registered on February 4, 2022, https://www.chictr.org.cn/showproj.aspx?proj=14131.

Histone deacetylase inhibitor and PD‑1 blockade synergistically inhibit B‑cell lymphoma progression in mice model by promoting T‑cell infiltration and apoptosis.

B‑cell lymphoma is difficult to cure because of its biological and clinical heterogeneity, and due to native chemoresistance. Immunotherapies that overcome cancer‑induced immune evasion have been the center of recent developments in oncology. This is emphasized by the accomplishment of various agents that disrupt programmed cell death protein 1 (PD‑1)‑mediated immune suppression in diverse tumors. However, while PD‑1 blockade has been effective in numerous malignancies, a significant proportion of cancers, including B‑cell lymphoma, show certain rates of primary resistance to these therapeutic strategies. Histone deacetylase inhibitors (HDACis) have exhibited anticancer activity though suppressing cell proliferation, inducing differentiation and triggering apoptosis. The present study aimed to explore a therapeutic strategy combining a HDACi (romidepsin) and PD‑1 blockade (BMS‑1) in B‑cell lymphoma, utilizing a constructed mouse model of B‑cell lymphoma. The IC50 of the two inhibitors was confirmed by MTT assay, and their inhibitory effects were revealed to be dose‑ and time‑dependent. The data demonstrated that the combined treatment of romidepsin and BMS‑1 synergistically inhibited the growth of B‑cell lymphoma. Furthermore, it was revealed that romidepsin and BMS‑1 synergistically triggered apoptosis in mouse B‑cell lymphoma. The synergistic effect of these agents was capable of activating tumor‑infiltrating lymphocytes, particularly CD3+CD4+ and CD3+CD8+ T cells. The results of the present study underscore the potential of HDAC inhibition in conjunction with PD‑1 blockade as a novel therapeutic approach for B‑cell lymphoma, highlighting the synergistic effects of these two mechanisms in enhancing antitumor immunity.

Genetic variations of penicillin-binding protein 1A: insights into the current status of amoxicillin-based regimens for Helicobacter pylori eradication in Malaysia.

Introduction. Resistance towards amoxicillin in Helicobacter pylori causes significant therapeutic impasse in healthcare settings worldwide. In Malaysia, the standard H. pylori treatment regimen includes a 14-day course of high-dose proton-pump inhibitor (rabeprazole, 20 mg) with amoxicillin (1000 mg) dual therapy.Hypothesis/Gap Statement. The high eradication rate with amoxicillin-based treatment could be attributed to the primary resistance rates of amoxicillin being relatively low at 0%, however, a low rate of secondary resistance has been documented in Malaysia recently.Aim. This study aims to investigate the amino acid mutations and related genetic variants in PBP1A of H. pylori, correlating with amoxicillin resistance in the Malaysian population.Methodology. The full-length pbp1A gene was amplified via PCR from 50 genomic DNA extracted from gastric biopsy samples of H. pylori-positive treatment-naïve Malaysian patients. The sequences were then compared with reference H. pylori strain ATCC 26695 for mutation and variant detection. A phylogenetic analysis of 50 sequences along with 43 additional sequences from the NCBI database was performed. These additional sequences included both amoxicillin-resistant strains (n=20) and amoxicillin-sensitive strains (n=23).Results. There was a total of 21 variants of amino acids, with three of them located in or near the PBP-motif (SKN402-404). The percentages of these three variants are as follows: K403X, 2%; S405I, 2% and E406K, 16%. Based on the genetic markers identified, the resistance rate for amoxicillin in our sample remained at 0%. The phylogenetic examination suggested that H. pylori might exhibit unique conserved pbp1A sequences within the Malaysian context.Conclusions. Overall, the molecular analysis of PBP1A supported the therapeutic superiority of amoxicillin-based regimens. Therefore, it is crucial to continue monitoring the amoxicillin resistance background of H. pylori with a larger sample size to ensure the sustained effectiveness of amoxicillin-based treatments in Malaysia.

Treatment failure is a key factor in the development of Helicobacter pylori resistance.

Helicobacter pylori eradication failure influences its antibiotic resistance. This study aimed to evaluate the effect of previous treatment failures on it, including the changes in the antibiotic resistance rates, minimal inhibitory concentration (MIC) distributions, and resistance patterns. This single-center retrospective study included 860 primary isolates and 247 secondary isolates. Antibiotic susceptibility testing was performed for amoxicillin, metronidazole, clarithromycin, levofloxacin, furazolidone, tetracycline, and rifampicin. The demographic data and detailed regimens were collected. The primary resistance rates to amoxicillin, metronidazole, clarithromycin, levofloxacin, tetracycline, rifampin, and furazolidone were 5.93%, 83.84%, 28.82%, 26.28%, 0.35%, 1.16%, and 0%, while secondary were 25.10%, 92.31%, 79.76%, 63.16%, 1.06%, 3.19%, and 0%, respectively. The resistance rates to amoxicillin, metronidazole, clarithromycin, and levofloxacin increased significantly with the number of treatment failures accumulated, and showed a linear trend. The proportion of primary and secondary multidrug-resistant (MDR) isolates were 17.79% and 63.16%, respectively. The MIC values of amoxicillin, clarithromycin, and levofloxacin were elevated significantly with medication courses increased. The prevalence of amoxicillin, clarithromycin, levofloxacin, and metronidazole resistance would increase rapidly following first-line treatment failure, as well as the MIC values of them. Clinicians should pay great attention to the first-line treatment to cure H. pylori infection successfully.

Antibiotic resistance in Helicobacter pylori among children and adolescents in East Asia: A systematic review and meta-analysis.

In East Asia, Helicobacter pylori ( H. pylori ) infection and related diseases are common, primarily during childhood and adolescence. The rates of primary antibiotic resistance in H. pylori among East Asian children and adolescents have not been extensively explored; few relevant systematic reviews or meta-analyses have been conducted. We evaluated the rates of antibiotic resistance in H. pylori among East Asian children and adolescents, with the goal of facilitating individualized treatment recommendations. We searched PubMed, Embase, and the Cochrane Library for studies in any language published up to February 2023 that explored antibiotic resistance in H. pylori among East Asian children and adolescents. We used MeSH and non-MeSH terms related to the topic, including terms related to children, adolescents, antibiotic resistance, H. pylori , and nations or regions. Additionally, we reviewed the reference lists of relevant articles. Studies that matched our strict predefined eligibility criteria were included in the screening process. Using established assessment methods, we evaluated the quality of the included studies. We identified 15 observational studies involving 4831 H. pylori isolates, all published between 2001 and 2022. There was substantial primary antibiotic resistance in H. pylori isolates from East Asian children and adolescents. The rates of primary resistance were 51% (95% confidence interval [CI]: 40-62%) for metronidazole; 37% (95% CI: 20-53%) for clarithromycin; 19% (95% CI: 11-28%) for levofloxacin; and less than 3% each for amoxicillin, tetracycline, and furazolidone. Subgroup analysis revealed a prominent increase in metronidazole resistance over time. Clarithromycin and levofloxacin resistance rates fluctuated between 2005 and 2015, then remained stable; other antibiotic resistance rates were generally stable. Metronidazole, clarithromycin, and levofloxacin resistance rates were significantly higher in the Chinese mainland than in other East Asian regions. The rates of dual and multiple antibiotic resistance were 28% (95% CI: 21-36%) and 10% (95% CI: 7-14%), highlighting the potential for diverse resistance patterns. H. pylori isolates from East Asian children and adolescents exhibit high levels of metronidazole and clarithromycin resistance, particularly in the Chinese mainland. The non-negligible rates of dual and multiple resistance highlight the complexity of this problem. PROSPERO, No. CRD42023402510.

Strengthening Multidrug-Resistant Tuberculosis Epidemiological Surveillance in Rio de Janeiro: a multidimensional analysis.

This study aimed to reinforce the importance of the epidemiological surveillance of multidrug-resistant tuberculosis (MDR-TB) in Rio de Janeiro State (RJ). Here, we reviewed seven articles we published between 2018 and 2022. This study had two phases. The quantitative phase where frequency was used to describe patient characteristics and regressions were used to evaluate the relationship between treatment outcomes and covariates. The qualitative phase where content analysis of the narratives was performed. Secondary (electronic systems) and primary (semi-structured interviews) data were used. We analyzed 2,269 MDR-TB, 58.1% MDR-TB, and 18.6% extensively drug-resistant TB (XDR-TB) cases, of which 44.3% exhibited unfavorable outcomes. Among the 140 patients with XDR-TB, 29.3% had not undergone prior treatment for MDR-TB. The primary resistance rate in MDR-TB cases was 14.7%, revealing significant demographic and clinical disparities, particularly among women, Caucasians, and those with higher education levels. The number of cases increased from 7.69% in 2000 to 38.42% in 2018, showing an increasing trend (AAPC = 9.4; 95% CI 1.4-18.0, p < 0.001), with 25.4% underreporting. A qualitative study confirmed a high proportion of primary resistance (64.5%) and delayed diagnosis of MDR-TB. In RJ, the diagnostic and therapeutic cascade of MDR-TB must be improved using molecular tests to achieve an early diagnosis of resistance and immediate initiation of appropriate treatment, promote social protection for MDR/XDR-TB patients and their families, enhance TB contact tracing, establish and monitor hospital surveillance centers integrated with Primary Care, and unify various information systems through interoperability for better integration.

Impact of Type of Lenvatinib Resistance on Prognosis and Second-Line Regimen in Patients with Virus-Associated HCC.

Lenvatinib is the first-line treatment option for patients with advanced hepatocellular carcinoma (HCC); however, the impact of lenvatinib resistance on patient prognosis is unknown. We recruited all patients with advanced HCC who received first-line lenvatinib treatment between February 2019 and February 2023 at two medical centers in China, according to the selection criteria. The patients were divided into primary and secondary resistance groups based on tumor progression within 3 months. The Kaplan-Meier method was used to calculate progression-free survival (PFS) and overall survival (OS). Logistic regression and Cox proportional hazards models were used to explore factors influencing drug resistance and prognosis. The study end points were drug resistance, PFS, and OS. A total of 531 patients met the study criteria, with 169 (31.8%) and 362 (68.2%) patients in the primary and secondary groups, respectively. An alpha-fetoprotein (AFP) concentration > 400 ng/mL was an independent risk factor for primary drug resistance. Patients in the primary group had a significantly shorter median OS (11.0 vs 31.0 months, P<0.001) than those in the secondary group. The 1-, 2- and 3-year cumulative survival rates in the primary group were 46.3%, 22.2%, and 10.1%, while those in the secondary group were 82.3%, 59.1% and 44.9%, respectively. Compared to tyrosine kinase inhibitor (TKI) monotherapy, longer median PFS (4.0 vs 7.0 months, P=0.008) and OS (11.0 vs 23.0 months, P=0.024) were achieved with the combination of a TKI plus a PD-1 inhibitor as a second-line therapy after lenvatinib resistance. There is a high rate of primary resistance to lenvatinib in patients with HCC and the prognosis for those with primary resistance is poor. TKI combined with PD-1 inhibitors should be preferentially recommended for lenvatinib-resistant patients.

Antibiotic resistance of Helicobacter pylori in Nanjing, China: a cross-section study from 2018 to 2023.

The increasing prevalence of antibiotic resistance in cases of Helicobacter pylori (H. pylori) infection has emerged as a significant global issue. This study offers a comprehensive examination of the alterations in drug resistance exhibited by H. pylori in the Nanjing region of China during the preceding five years. Another important objective is to investigate the influence of levofloxacin medication history on genotypic and phenotypic resistance. This research screened 4277 individuals diagnosed with H. pylori infection between April 2018 and May 2023. The phenotype and genotypic resistance were evaluated using the Kirby-Bauer disk diffusion and PCR method. The most recent primary resistance rates for metronidazole, clarithromycin, levofloxacin, amoxicillin, furazolidone, and tetracycline were recorded at 77.23% (2385/3088), 37.24% (1150/3088), 27.72% (856/3088), 0.52% (16/3088), 0.19% (6/3088), and 0.06% (2/3088), respectively. For the recent five years, we observed a notable upsurge in the rate of metronidazole resistance and a slight elevation of clarithromycin and levofloxacin resistance. The documented resistance rates to single-drug, dual-drug, triple-drug, and quadruple-drug regimens were 35.39%, 28.32%, 25.72%, and 0.21%, respectively. The prevalence of multidrug-resistant strains escalated, rising from 37.96% in 2018 to 66.22% in 2023. The rate of phenotypic and genotypic resistance rate (57.10% and 65.57%) observed in strains obtained from patients without a levofloxacin treatment history was significantly lower than the rate in strains obtained from those with a history of levofloxacin treatment (88.73% and 94.74%). The prevailing gyrA mutations were primarily N87K (52.35%, 345/659), accompanied by D91N (13.96%, 92/659), and closely followed by D87G (10.77%, 71/659). For gyrA mutations, the 91-amino acid mutants exhibit a higher likelihood of discrepancies between phenotypic and genotypic resistance than the 87-amino acid mutants. The extent of antibiotic resistance within H. pylori remains substantial within the Nanjing region. If levofloxacin proves ineffective in eradicating H. pylori during the initial treatment, its use in subsequent treatments is discouraged. The employment of levofloxacin resistance genotype testing can partially substitute conventional antibiotic sensitivity testing. Notably, predicting phenotypic resistance of levofloxacin through PCR requires more attention to the mutation type of gyrA to improve prediction accuracy.

Antimicrobial-resistant Helicobacter pylori in Japan: Report of nationwide surveillance for 2018-2020.

Antimicrobial therapy is necessary to eradicate Helicobacter pylori infection. The emergence of antimicrobial-resistant bacteria poses a threat to continued treatment with antimicrobial agents. For those who prescribe antimicrobial therapy, it is necessary to constantly monitor the emergence of antimicrobial-resistant bacteria. H. pylori clinical isolates were collected in Japan from August 2018 to December 2020 for antimicrobial susceptibility testing. The agar dilution method was used for the determination of the minimum inhibitory concentration (MIC) of clarithromycin (CLR), amoxicillin (AMX), metronidazole (MNZ), and sitafloxacin (STX). MICs for 938 H. pylori isolates were examined. The primary resistance rates of H. pylori clinical isolates for CLR, AMX, MNZ, and STX in Japan were 35.5%, 2.7%, 4.2%, and 27.6%, respectively. The primary resistance rates for CLR, AMX, and MNZ were significantly higher than those of the 2002-2005 isolates. The resistance rate for CLR was significantly higher in females (males: 30.7%, females: 41.5%, p < 0.001) and higher in the ≤29 years age group (54.8%) than in the other age groups, although there were no significant differences (p = 0.104). The MNZ resistance rate was significantly higher in the ≤29 years age group than in the other age groups (p = 0.004). The resistance rate for STX increased with age, but a significant difference was only seen between the 30-49 years age group and the ≥70 years age group (p < 0.001), and the resistance rate was significantly higher in strains isolated in the Kyushu region than in the other regions (p < 0.001). The primary resistance rates for CLR, AMX, and MNZ of H. pylori clinical isolates in Japan were higher than those of the 2002-2005 isolates. Continuous surveillance is needed to monitor the trends in antimicrobial-resistant H. pylori.

Surveillance of Helicobacter pylori resistance over 22 Years (2000-2021) in Northern Spain

Helicobacter pylori gastritis is considered an infectious disease, regardless of symptoms and stage of disease. Most consensus documents recommend empirical therapy based on local antimicrobial susceptibility patterns. We aimed to provide clinically useful information about primary and secondary antimicrobial resistance to antimicrobials commonly prescribed for H. pylori. Overall, 31,406 gastroduodenal biopsies and 2,641 string tests from patients over 15 years of age were plated on selective media, isolating H. pylori in 36.7% of biopsies and 50.7% of string tests. Susceptibility testing could be performed in 96.6% (12,399/12,835) of H. pylori isolates. Polymerase chain reaction (PCR) was also used to detect H. pylori and its resistance to clarithromycin, providing susceptibility data for 112 patients with negative culture results. Resistance to amoxicillin and tetracycline was unusual (0.6% and 0.2%, respectively). Rates of primary resistance to clarithromycin and metronidazole remained steady over the 22-year study period, at around 14% for clarithromycin and 30% for metronidazole, while primary resistance to levofloxacin tripled (from 7.6% in 2000 to 21.7% in 2021, P < 0.001) and increased with patient age. Notably, 1.8% of isolates were multiresistant to clarithromycin, metronidazole, and levofloxacin. Overall, secondary resistance rates were higher (P < 0.0001) than primary resistance rates for clarithromycin (42.5% vs 14.1%), metronidazole (40.9% vs 32%), and levofloxacin (21.5% vs 17.1%). Determination of susceptibility for H. pylori by culture and/or PCR in patients undergoing endoscopy could facilitate the implementation of tailored therapy and guide the choice of empirical therapy when susceptibility testing cannot be performed, potentially helping limit the emergence of antimicrobial resistance.

Antibiotic resistance, heteroresistance, and eradication success of Helicobacter pylori infection in children.

Antibiotic resistance is a well-known factor of Helicobacter pylori eradication failure. Heteroresistance indicates the coexistence of resistant and susceptible strains and might lead to underestimating antimicrobial resistance. This study aims to evaluate the susceptibility profile, the frequency of heteroresistance of H. pylori strains, and their effect on eradication success in a pediatric population. Children aged 2-17 years who underwent an upper gastrointestinal endoscopy from 2011 to 2019 with positive H. pylori status were included. Susceptibility was measured by disk diffusion and E-test. The difference in susceptibility profiles between isolates from the antrum and the corpus was used to detect heteroresistance. For those who received eradication treatment, we evaluated eradication rate and factors affecting treatment success. Inclusion criteria were met by 565 children. Strains susceptible to all antibiotics were detected in 64.2%. Primary resistance rates for clarithromycin (CLA), metronidazole (MET), levofloxacin (LEV), tetracyclin (TET), and amoxicillin (AMO) were 11%, 22.9%, 6.9%, 0.4%, and 0% and secondary resistance rates were 20.4%, 29.4%, 9.3%, 0%, and 0%. Heteroresistance was present in untreated children in 2%, 7.1%, 0.7%, 0.7%, and 0% for CLA, MET, LEV, TET, and AMO. First-line eradication rates were 78.5% in intention-to-treat (ITT), 88.3% in full-analysis-set (FAS), and 94.1% in per-protocol (PP). Factors affecting eradication success were the duration of treatment when the triple-tailored treatment was used, the number of daily doses of amoxicillin administered, and the patient's adherence to treatment. This study shows the presence of relatively low primary resistance rates for H. pylori isolates but demonstrates the presence of heteroresistance in our population. Routine biopsies from the antrum and corpus must be considered for susceptibility testing to allow tailored treatments and increase eradication rates. Treatment success is affected by treatment choice, correct dosing of medications, and adherence. All these factors should be considered when evaluating the efficacy of an eradication regimen.

77P BRCA mutations may induce immune-resistance in breast cancer patients treated with IO-only approach: A retrospective analysis

Immunotherapy (IO) has been recently introduced in triple-negative breast cancer (TNBC) therapeutic algorithm, however no predictive biomarkers beyond PDL-1 expression demonstrated utility in clinical practice. BRCA mutations account for 15-20% of TNBC, with a positive association with platinum response and an inflammatory background on tumor tissue. Preclinical evidences demonstrated a lack of T-cell activation in BRCA-mutant (BRCAm) tumors due to an HLA machinery defects, but no subgroup effects were observed in IO pivotal trials evaluating chemotherapy-IO combinations. We retrospectively evaluated the effect of germline BRCA mutations in consecutive BC patients underwent any-line IO-only treatment in phase I/II trials at Fondazione IRCCS Istituto Nazionale dei Tumori in Milan. Only mutations evaluated as pathogenic after genetic counselling were considered. IO treatment included PD(L)1, LAG3 and ICOS inhibitors, single agents or in combination. Statistical analysis were performed with RStudio software v2022.07.0. Of 39 pts treated with IO from June 2016 to September 2022, 22 had available germline BRCA status. 4 pts exhibited mutations in BRCA1 gene, 1 in BRCA2. All pts had triple-negative histology, except one (HR+). Median number of previous treatment lines for metastatic disease was 2 (1-8), without significant difference among BRCA groups (p=0.872). None of the other clinical features evaluated significantly differ among BRCA groups. 18 (81.8%) patients received platinum compound as therapy for metastatic disease, while 4 (18.2) received a PARP inhibitor. BRCAm pts demonstrated a significantly shorted PFS compared to wild-type (1.7 vs 3.6 months; HR 4.12, CI 95% 1.32-12.89, p=0.015), whereas a non-significant trend toward a worse OS was observed in BRCAm pts (77.1 vs 42.0 months; HR 2.31, CI 95% 0.65-8.24, p=0.199). A numerically higher primary resistance rate was also observed in BRCAm pts (80% vs 50%). In our small retrospective cohort, the presence of a pathogenic mutation in BRCA1/2 genes resulted in reduced benefit to IO-alone approach. If confirmed in a wider and prospective cohort, these results could guide the decision on first-line treatment of BRCAm TNBC.

Primary drug resistance of M. tuberculosis according to the Center of Excellence of the WHO Network of Supranational Reference Laboratories of the CTRI in 2016–2021

ntroduction. Culture research and testing of Mycobacterium tuberculosis (MBT) for drug susceptibility in the Russian Federation is carried out with uneven qual-ity, which distorts the idea of primary drug resistance (DR). Aim. To study the primary DR of MBT to the main combinations of anti-TB drugs for 2016–2021 according at the Center of Excellence of the WHO Supranational Reference Laboratories Network at the Central Tuber-culosis Research Institute. Methods. Data on drug sus-ceptability and frequency of resistance to the main com-binations of anti-TB drugs (in accordance with updated definitions) of MBT isolated before treatment were stud-ied in 966 new TB cases from 69 regions of the Russian Federation examined at the Center of Excellence of the WHO Supranational Reference Laboratories Network at the Central Tuberculosis Research Institute from 2016 to 2021. Results. The rate of any primary drug resistance to rifampicin was 46.2%; 95% CI [43.0–49.3], MDR — 45.8%; 95% CI [42.6–48.9], pre-XDR — 24.2%; 95% CI [21.5–27.0], XDR — 5.4%; 95% CI [3.3–8.0]. Over time, there was a decrease in primary MDR MBT from 48.7% in 2016 and 54.9% in 2017 to 36.8% in 2021. The frequency of pre-XDR did not change during the observation peri-od. There was a statistically significant increase in the incidence of primary XDR from 2.1%; 95% CI [0.4–11.1] in 2016 and 0.0% in 2017 to 11.0%; 95% CI [6.1–19.1] in 2021 (p=0.03). Conclusion. The rate of primary MBT drug resistance to the main anti-TB combinations, ac-cording to our study, significantly exceeds the overall figures for Russian Federation. This suggests that the situation with MDR, pre-XDR, and XDR tuberculosis in the Russian Federation is much more alarming than we see from the regular reports, while the quality of local microbiological diagnostics on is insufficient

RELATIONSHIP OF HELICOBACTER PYLORI CAGA AND VACA STATUS TO MORPHOLOGICAL CHANGES OF GASTRIC MUCOSA AND PRIMARY CLARITHROMYCIN RESISTANCE RATE IN PATIENTS WITH CHRONIC GASTRITIS: A CROSS-SECTIONAL STUDY.

The aim: To investigate the relation of H. pylori CagA and VacA status to morphological changes of gastric mucosa and primary clarithromycin resistance rate in patients with chronic gastritis. Materials and methods: A cross-sectional study was conducted between May 2021 and January 2023, involving 64 patients with H. pylori-associated chronić gastritis. The patients were assigned to two groups according to the H. pylori virulence factors (CagA and VacA) status. The grades of inflammation, activity, atrophy, and metaplasia were determined according to the Houston-updated Sydney system. The identification of H. pylori genetic markers of antibiotic resistance and pathogenicity was performed by the polymerase chain reaction using paraffin stomach biopsies. Results: Patients with CagA- and VacA-positive H. pylori strains had significantly higher grades of inflammation both in the antrum and in the corpus of the stomach, activity of gastritis in the antrum, higher incidence and grade of atrophy in the antrum. Primary resistance to clarithromycin was significantly more prevalent in patients with CagA- and VacA-negative H. pylori strains (58.3% vs. 11.5%, p=0.002). Conclusions: Positive CagA and VacA status is related to more severe histopathological changes of gastric mucosa. In contrast, the rate of primary clarithromycin resistance is higher in patients CagA- and VacA-negative H. pylori strains.

Prevalence of resistance mutations associated with integrase inhibitors in therapy-naive HIV-positive patients in Baoding, Hebei province, China.

Antiretroviral therapy (ART) regimens containing integrase strand transfer inhibitors (INSTIs) are the recommended treatment for human immunodeficiency virus type 1 (HIV-1)-infected patients in the most recent guidelines in China. In this study, we investigated INSTI resistance mutations in newly diagnosed therapy-naive HIV-positive patients in Baoding City, Hebei Province (China) to provide guidance for implementing routine INSTI-associated HIV-1 genotypic resistance testing. Plasma samples were collected from HIV-1-infected patients without treatment at Baoding People’s Hospital from January 2020 to December 2021. The part of HIV-1 pol gene encoding integrase was amplified, sequenced, and analyzed for INSTI resistance. Clinical data including demographic data, CD4+ T cell counts, HIV-RNA loads, and resistance mutations were collected. Treatment-naïve HIV-1 patients (n = 131) were enrolled. We identified ten genotypes, and the predominant genotype was CRF01_AE in 67 patients (51.15%), CRF07_ BC in 39 patients (29.77%), subtype B in 11 patients (8.40%), and other subtypes (CRF68_01B, 3.82%; CRF55_01B, 1.53%, CRF80_0107, 1.53%; URFs 1.53%; and CRF103_01B, CRF59_01B, and CRF65_cpx, 1.4% each). Four major (E138A, R263k, G140S, and S147G) and three accessory (H51Y, Q146QL, and S153F) INSTI-resistance mutations were observed (genotype CRF01_AE, three patients; genotype B, one patient; and genotype CRF07_BC, one patient), resulting in different degrees of resistance to the following five INSTIs: raltegravir, elvitegravir, dolutegravir, bictegravir, and cabotegravir. The overall resistance rate was 3.82% (5/131). All INSTI-resistant strains were cross-resistant. The primary INSTI drug resistance rate among newly diagnosed HIV-infected patients in Baoding was low, but monitoring and research on HIV INSTI resistance should be strengthened in Baoding because INSTI-based regimen prescriptions are anticipated to increase in the near future.

Antibiotic resistance of Helicobacter pylori isolated from patients in Nanjing, China: A cross-section study from 2018 to 2021.

The increasing antibiotic resistance of Helicobacter pylori infection is a globally urging problem. To investigate the H. pylori resistance situation in Nanjing, China, we enrolled patients in Nanjing First Hospital from January 2018 to May 2021. H. pylori strains were isolated from patients who had at least one positive 13C-urea breath or rapid urease result. Subsequently, we performed antibiotic susceptibility tests on the isolated strains to clarithromycin, metronidazole, levofloxacin, amoxicillin, furazolidone and tetracycline. ARMS-PCR was conducted to determine H. pylori clarithromycin resistance gene mutation. Our results demonstrated that the primary resistance rates of metronidazole, clarithromycin, levofloxacin, amoxicillin, furazolidone and tetracycline were 67.19% (1417/2109), 35.99% (759/2109), 24.23% (511/2109), 0.76% (16/2109), 0.28% (6/2109) and 0.09% (2/2109), respectively. The resistance rates of metronidazole, clarithromycin and levofloxacin elevated significantly after treatment and the three antibiotics composed the majority of multi-resistance patterns. However, the resistance rates of amoxicillin, furazolidone and tetracycline were still in low levels after treatment. ARMS-PCR showed a rather good consistency with antibiotic susceptibility test in detecting clarithromycin resistance, with a kappa value of 0.79. Overall, this study revealed the latest complex situation of antibiotic resistance of H. pylori infection in Nanjing and offered suggestions on clinical medication for curing H. pylori.

Prevalence of Helicobacter pylori resistance to clarithromycin in Tunisia.

Background. Helicobacter pylori (H. pylori) resistance to clarithromycin is increasing worldwide. Data on the prevalence of H. pylori resistance are limited in Tunisia.Gap statement. Given that H. pylori resistance to clarithromycin has not been studied in Tunisia since 2010, there was a need to determinate its prevalence and the principal mutations implicated in this resistance.Aim. The aims were to define the prevalence of H. pylori infection among symptomatic patients and to determinate the level of clarithromycin resistance among these patients and the main mutations conferring this resistance.Methods. We conducted a cross-sectional study from March 2017 to February 2020 in the Hepato-Gastroenterology Department of Hedi Chaker University Hospital in Sfax that included 124 Tunisian patients who underwent gastroduodenal endoscopy with biopsies. Mutations conferring resistance to clarithromycin were detected using the Allplex H. pylori and ClariR PCR Assay.Results. Out of 124 biopsies, 101 (81.5 2 %) were PCR-positive for H. pylori. Mutations conferring resistance to clarithromycin were detected in 30/95 (31.6 %) of patients. The rate of primary resistance was 25.3 % and of secondary resistance 62.5 %. The most frequently detected mutation was A2143G (86, 90%) followed by A2142G (11, 36%). Seven patients had a double mutation A2143G-A2142G. The factors independently associated with resistance to clarithromycin were diabetes, high blood pressure, the presence of a bulbar ulcer on endoscopy and the presence of gastric atrophy on histology.Conclusion. Detection of more than 25 % of strains with clarithromycin resistance mutations makes the H. pylori first-line treatment with clarithromycin questionable in our setting, and a review of empirical treatment of H. pylori is urgently needed.

Efficacy and safety of high-dose esomeprazole-amoxicillin dual therapy for Helicobacter pylori rescue treatment: a multicenter, prospective, randomized, controlled trial.

Background:High-dose dual therapy (HDDT) with proton pump inhibitors (PPIs) and amoxicillin has attracted widespread attention due to its favorable efficacy in eradicating Helicobacter pylori (H. pylori). This study aimed to compare the efficacy and safety of high-dose PPI–amoxicillin dual therapy and bismuth-containing quadruple therapy for H. pylori rescue treatment.Methods:This was a prospective, randomized, multicenter, non-inferiority trial. Patients recruited from eight centers who had failed previous treatment were randomly (1:1) allocated to two eradication groups: HDDT (esomeprazole 40 mg and amoxicillin 1000 mg three times daily; the HDDT group) and bismuth-containing quadruple therapy (esomeprazole 40 mg, bismuth potassium citrate 220 mg, and furazolidone 100 mg twice daily, combined with tetracycline 500 mg three times daily; the tetracycline, furazolidone, esomeprazole, and bismuth [TFEB] group) for 14 days. The primary endpoint was the H. pylori eradication rate. The secondary endpoints were adverse effects, symptom improvement rates, and patient compliance.Results:A total of 658 patients who met the criteria were enrolled in this study. The HDDT group achieved eradication rates of 75.4% (248/329), 81.0% (248/306), and 81.3% (248/305) asdetermined by the intention-to-treat (ITT), modified intention-to-treat (MITT), and per-protocol (PP) analyses, respectively. The eradication rates were similar to those in the TFEB group: 78.1% (257/329), 84.2% (257/305), and 85.1% (257/302). The lower 95% confidence interval boundary (−9.19% in the ITT analysis, − 9.21% in the MITT analysis, and −9.73% in the PP analysis) was greater than the predefined non-inferiority margin of −10%, establishing a non-inferiority of the HDDT group vs. the TFEB group. The incidence of adverse events in the HDDT group was significantly lower than that in the TFEB group (11.1% vs. 26.8%, P < 0.001). Symptom improvement rates and patients’ compliance were similar between the two groups.Conclusions:Fourteen-day HDDT is non-inferior to bismuth-containing quadruple therapy, with fewer adverse effects and good treatment compliance, suggesting HDDT as an alternative for H. pylori rescue treatment in the local region.Trial registration:Clinicaltrials.gov, NCT04678492.

Combination of AKT1 and CDH1 mutations predicts primary resistance to immunotherapy in dMMR/MSI-H gastrointestinal cancer

BackgroundGastrointestinal (GI) cancer is the second most common cancer type with mismatch repair-deficient (dMMR)/microsatellite instability-high (MSI-H) phenotype that is expected to respond to immune-checkpoint inhibitors (ICIs). However, approximately half of...

Risk factors for dapsone resistance in leprosy patients: a systematic meta-analysis

Dapsone is one of the important drugs in the treatment of leprosy. The present study aims to evaluate the resistance of Mycobacterium leprae isolates to dapsone, in turn assisting in implementing better control strategies for leprosy elimination. A systematic literature search was conducted in PubMed, Embase, Medline, and Web of Science. Two independent reviewers selected the literature according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), extracted data, and evaluated the risk of bias. Drug resistance data were pooled using the random-effects model. Subgroup analysis was performed based on across sampling time, region, study population (treatment status, relapses status), and sample size. A total of 30 studies were included. The results of meta-analysis showed that the dapsone resistance rate of leprosy patients after treatment was 8% (95% confidence interval [CI], 6%-10%). Compared to the rates of primary resistance of new cases without treatment therapy (pooled incidence, 4% [95% CI, 2%-5%]), treatment cases (13% [95% CI 9%-16%]) had secondary resistance, and relapse cases (26% [95% CI, 18%-33%]) had drug resistance. In addition, the drug resistance rate of monotherapy was significantly increased than that of relapsed patients treated with diamino-diphenylsulfonemonotherapy. Subgroup analysis showed that the patients in the Western Pacific have the highest dapsone resistance, and the resistance to dapsone was slightly lower after 2005. For sample size, the rate in the group under 100 samples was significantly higher than in the other. Dapsone resistance is closely related to leprosy relapse and long-term drug use. Dapsone monotherapy is one of important reasons for drug resistance in relapsed cases. Drug resistance varies among different populations and regions of the world.