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Ayaş M, Oktem-Okullu S, Özcan O, Kocagöz T, Gürol Y. Exploring the Molecular Mechanisms of Macrolide Resistance in Laboratory Mutant Helicobacter pylori. Antibiotics (Basel) 2024; 13:396. [PMID: 38786125 PMCID: PMC11117244 DOI: 10.3390/antibiotics13050396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 04/10/2024] [Accepted: 04/18/2024] [Indexed: 05/25/2024] Open
Abstract
Resistance to clarithromycin, a macrolide antibiotic used in the first-line treatment of Helicobacter pylori infection, is the most important cause of treatment failure. Although most cases of clarithromycin resistance in H. pylori are associated with point mutations in 23S ribosomal RNA (rRNA), the relationships of other mutations with resistance remain unclear. We examined possible new macrolide resistance mechanisms in resistant strains using next-generation sequencing. Two resistant strains were obtained from clarithromycin-susceptible H. pylori following exposure to low clarithromycin concentrations using the agar dilution method. Sanger sequencing and whole-genome sequencing were performed to detect resistance-related mutations. Both strains carried the A2142G mutation in 23S rRNA. Candidate mutations (T1495A, T1494A, T1490A, T1476A, and G1472T) for clarithromycin resistance were detected in the Mutant-1 strain. Furthermore, a novel mutation in the gene encoding for the sulfite exporter TauE/SafE family protein was considered to be linked to clarithromycin resistance or cross-resistance, being identified as a target for further investigations. In the Mutant-2 strain, a novel mutation in the gene that encodes DUF874 family protein that can be considered as relevant with antibiotic resistance was detected. These mutations were revealed in the H. pylori genome for the first time, emphasizing their potential as targets for advanced studies.
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Affiliation(s)
- Meltem Ayaş
- Department of Medical Laboratory Techniques, Vocational School of Health Services, Acibadem Mehmet Ali Aydinlar University, 34752 Istanbul, Turkey
- Department of Medical Biotechnology, Institute of Health Sciences, Acibadem Mehmet Ali Aydinlar University, 34752 Istanbul, Turkey;
| | - Sinem Oktem-Okullu
- Department of Medical Microbiology, Faculty of Medicine, Acibadem Mehmet Ali Aydinlar University, 34752 Istanbul, Turkey; (S.O.-O.); (Y.G.)
| | - Orhan Özcan
- TrioScience Biotechnology, 34000 Istanbul, Turkey;
| | - Tanıl Kocagöz
- Department of Medical Biotechnology, Institute of Health Sciences, Acibadem Mehmet Ali Aydinlar University, 34752 Istanbul, Turkey;
- Department of Medical Microbiology, Faculty of Medicine, Acibadem Mehmet Ali Aydinlar University, 34752 Istanbul, Turkey; (S.O.-O.); (Y.G.)
| | - Yeşim Gürol
- Department of Medical Microbiology, Faculty of Medicine, Acibadem Mehmet Ali Aydinlar University, 34752 Istanbul, Turkey; (S.O.-O.); (Y.G.)
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Gong X, Wang Y, An Y, Li Z, Liu D, Yong X. The crosstalk between efflux pump and resistance gene mutation in Helicobacter pylori. Gut Microbes 2024; 16:2379439. [PMID: 39052777 PMCID: PMC11275522 DOI: 10.1080/19490976.2024.2379439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2024] [Revised: 06/11/2024] [Accepted: 07/08/2024] [Indexed: 07/27/2024] Open
Abstract
Efflux pumps play a crucial role in the development of antibiotic resistance. The aim of this study was to investigate the relationship between efflux pump gene expression and resistance gene mutations in Helicobacter pylori. Twenty-six clinical strains with varying resistance characteristics were selected for further experiment. Seven susceptible strains were induced to become resistant, and the expression of efflux pump genes and point mutations were recorded. Four susceptible strains were selected to undergo candidate mutation construction, and changes in efflux pump gene expression were detected. Efflux pump knockout strains were constructed, and their effects on preventing and reversing antibiotic resistance gene mutations were assessed. Results showed that the expression of efflux pump genes hefA and hefD was significantly higher in the multidrug-resistant group compared to other groups. During the process of antibiotic-induced resistance, efflux pump gene expression did not exhibit a steady increase or decrease. Strains with the A2143G or A2142G point mutations in 23S rRNA exhibited lower hefA gene expression. Strains with mutations at 87K/91N, 87N/91 G, 87K/91D, or 87N/91Y in gyrA and the 194insertA mutation in rdxA showed higher hefA gene expression compared to the wild-type strain. During the process of antibiotic-induced resistance, the strain with the knockout of the efflux pump gene hefA developed mutations in the 23S rRNA, gyrA, or rdxA genes later compared to the wild-type strain. Knockout of the efflux pump gene could reverse the phenotypic resistance to clarithromycin or metronidazole in some strains but had no effect on reverse resistance gene mutation. This study suggested that different resistance gene point mutations may have varying effects on efflux pump gene expression. Knockout of the efflux pump gene can delay or prevent antibiotic resistance gene mutations to some extent and can reverse phenotypic resistance to clarithromycin and metronidazole in certain strains.
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Affiliation(s)
- Xiaoling Gong
- Department of Gastroenterology, Digestive Disease Hospital, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
- Department of Gastroenterology, Gastroenterology Institute of Jiangxi Province, Nanchang, Jiangxi, China
- Jiangxi Provincial Key Laboratory of Digestive Diseases, Department of Gastroenterology, The First Affiliated Hospital, Jiangxi Medical College, Nanchang, Jiangxi, China
- Department of Gastroenterology, Jiangxi Clinical Research Center for Gastroenterology, Nanchang, Jiangxi, China
| | - Youhua Wang
- Department of Gastroenterology, Digestive Disease Hospital, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
- Department of Gastroenterology, Gastroenterology Institute of Jiangxi Province, Nanchang, Jiangxi, China
- Jiangxi Provincial Key Laboratory of Digestive Diseases, Department of Gastroenterology, The First Affiliated Hospital, Jiangxi Medical College, Nanchang, Jiangxi, China
- Department of Gastroenterology, Jiangxi Clinical Research Center for Gastroenterology, Nanchang, Jiangxi, China
| | - Ying An
- Department of Gastroenterology, Digestive Disease Hospital, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
- Department of Gastroenterology, Gastroenterology Institute of Jiangxi Province, Nanchang, Jiangxi, China
- Jiangxi Provincial Key Laboratory of Digestive Diseases, Department of Gastroenterology, The First Affiliated Hospital, Jiangxi Medical College, Nanchang, Jiangxi, China
- Department of Gastroenterology, Jiangxi Clinical Research Center for Gastroenterology, Nanchang, Jiangxi, China
- Department of Medical, Jinyu Medical Laboratory Co. Ltd, Shenyang Province, Liaoning, China
| | - Zhen Li
- Department of Gastroenterology, Digestive Disease Hospital, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
- Department of Gastroenterology, Gastroenterology Institute of Jiangxi Province, Nanchang, Jiangxi, China
- Jiangxi Provincial Key Laboratory of Digestive Diseases, Department of Gastroenterology, The First Affiliated Hospital, Jiangxi Medical College, Nanchang, Jiangxi, China
- Department of Gastroenterology, Jiangxi Clinical Research Center for Gastroenterology, Nanchang, Jiangxi, China
- Department of Clinical Nursing, Heze Health School, Shandong Province, Jinan, China
| | - Dongsheng Liu
- Department of Gastroenterology, Digestive Disease Hospital, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
- Department of Gastroenterology, Gastroenterology Institute of Jiangxi Province, Nanchang, Jiangxi, China
- Jiangxi Provincial Key Laboratory of Digestive Diseases, Department of Gastroenterology, The First Affiliated Hospital, Jiangxi Medical College, Nanchang, Jiangxi, China
- Department of Gastroenterology, Jiangxi Clinical Research Center for Gastroenterology, Nanchang, Jiangxi, China
| | - Xie Yong
- Department of Gastroenterology, Digestive Disease Hospital, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
- Department of Gastroenterology, Gastroenterology Institute of Jiangxi Province, Nanchang, Jiangxi, China
- Jiangxi Provincial Key Laboratory of Digestive Diseases, Department of Gastroenterology, The First Affiliated Hospital, Jiangxi Medical College, Nanchang, Jiangxi, China
- Department of Gastroenterology, Jiangxi Clinical Research Center for Gastroenterology, Nanchang, Jiangxi, China
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Al-Fakhrany OM, Elekhnawy E. Helicobacter pylori in the post-antibiotics era: from virulence factors to new drug targets and therapeutic agents. Arch Microbiol 2023; 205:301. [PMID: 37550555 PMCID: PMC10406680 DOI: 10.1007/s00203-023-03639-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 07/16/2023] [Accepted: 07/20/2023] [Indexed: 08/09/2023]
Abstract
Helicobacter pylori is considered one of the most prevalent human pathogenic microbes globally. It is the main cause of a number of gastrointestinal ailments, including peptic and duodenal ulcers, and gastric tumors with high mortality rates. Thus, eradication of H. pylori is necessary to prevent gastric cancer. Still, the rise in antibiotic resistance is the most important challenge for eradication strategies. Better consideration of H. pylori virulence factors, pathogenesis, and resistance is required for better eradication rates and, thus, prevention of gastrointestinal malignancy. This article is aimed to show the role of virulence factors of H. pylori. Some are involved in its survival in the harsh environment of the human gastric lumen, and others are related to pathogenesis and the infection process. Furthermore, this work has highlighted the recent advancement in H. pylori treatment, as well as antibiotic resistance as a main challenge in H. pylori eradication. Also, we tried to provide an updated summary of the evolving H. pylori control strategies and the potential alternative drugs to fight this lethal resistant pathogen. Recent studies have focused on evaluating the efficacy of alternative regimens (such as sequential, hybrid, concomitant treatment, vonoprazan (VPZ)-based triple therapy, high-dose PPI-amoxicillin dual therapy, probiotics augmented triple therapy, or in combination with BQT) in the effective eradication of H. pylori. Thus, innovating new anti-H. pylori drugs and establishing H. pylori databanks are upcoming necessities in the near future.
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Affiliation(s)
- Omnia Momtaz Al-Fakhrany
- Pharmaceutical Microbiology Department, Faculty of Pharmacy, Tanta University, Tanta, 31527 Egypt
| | - Engy Elekhnawy
- Pharmaceutical Microbiology Department, Faculty of Pharmacy, Tanta University, Tanta, 31527 Egypt
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Alfaray RI, Saruuljavkhlan B, Fauzia KA, Torres RC, Thorell K, Dewi SR, Kryukov KA, Matsumoto T, Akada J, Vilaichone RK, Miftahussurur M, Yamaoka Y. Global Antimicrobial Resistance Gene Study of Helicobacter pylori: Comparison of Detection Tools, ARG and Efflux Pump Gene Analysis, Worldwide Epidemiological Distribution, and Information Related to the Antimicrobial-Resistant Phenotype. Antibiotics (Basel) 2023; 12:1118. [PMID: 37508214 PMCID: PMC10376887 DOI: 10.3390/antibiotics12071118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 06/15/2023] [Accepted: 06/25/2023] [Indexed: 07/30/2023] Open
Abstract
We conducted a global-scale study to identify H. pylori antimicrobial-resistant genes (ARG), address their global distribution, and understand their effect on the antimicrobial resistance (AMR) phenotypes of the clinical isolates. We identified ARG using several well-known tools against extensive bacterial ARG databases, then analyzed their correlation with clinical antibiogram data from dozens of patients across countries. This revealed that combining multiple tools and databases, followed by manual selection of ARG from the annotation results, produces more conclusive results than using a single tool or database alone. After curation, the results showed that H. pylori has 42 ARG against 11 different antibiotic classes (16 genes related to single antibiotic class resistance and 26 genes related to multidrug resistance). Further analysis revealed that H. pylori naturally harbors ARG in the core genome, called the 'Set of ARG commonly found in the Core Genome of H. pylori (ARG-CORE)', while ARG-ACC-the ARG in the accessory genome-are exclusive to particular strains. In addition, we detected 29 genes of potential efflux pump-related AMR that were mostly categorized as ARG-CORE. The ARG distribution appears to be almost similar either by geographical or H. pylori populations perspective; however, some ARG had a unique distribution since they tend to be found only in a particular region or population. Finally, we demonstrated that the presence of ARG may not directly correlate with the sensitive/resistance phenotype of clinical patient isolates but may influence the minimum inhibitory concentration phenotype.
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Affiliation(s)
- Ricky Indra Alfaray
- Department of Environmental and Preventive Medicine, Faculty of Medicine, Oita University, Oita 879-5593, Japan
- Helicobacter pylori and Microbiota Study Group, Institute of Tropical Disease, Universitas Airlangga, Surabaya 60286, Indonesia
| | - Batsaikhan Saruuljavkhlan
- Department of Environmental and Preventive Medicine, Faculty of Medicine, Oita University, Oita 879-5593, Japan
| | - Kartika Afrida Fauzia
- Department of Environmental and Preventive Medicine, Faculty of Medicine, Oita University, Oita 879-5593, Japan
- Helicobacter pylori and Microbiota Study Group, Institute of Tropical Disease, Universitas Airlangga, Surabaya 60286, Indonesia
- Department of Public Health and Preventive Medicine, Faculty of Medicine, Universitas Airlangga, Surabaya 60132, Indonesia
| | - Roberto C Torres
- The Center for Microbes, Development and Health, Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai 200031, China
| | - Kaisa Thorell
- Department of Chemistry and Molecular Biology, Faculty of Science, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Selva Rosyta Dewi
- Department of Environmental and Preventive Medicine, Faculty of Medicine, Oita University, Oita 879-5593, Japan
- Helicobacter pylori and Microbiota Study Group, Institute of Tropical Disease, Universitas Airlangga, Surabaya 60286, Indonesia
| | - Kirill A Kryukov
- Biological Networks Laboratory, Department of Informatics, National Institute of Genetics, Shizuoka 411-8540, Japan
| | - Takashi Matsumoto
- Department of Environmental and Preventive Medicine, Faculty of Medicine, Oita University, Oita 879-5593, Japan
| | - Junko Akada
- Department of Environmental and Preventive Medicine, Faculty of Medicine, Oita University, Oita 879-5593, Japan
| | - Ratha-Korn Vilaichone
- Gastroenterology Unit, Department of Medicine, Faculty of Medicine, Thammasat University Hospital, Khlong Nueng 12120, Pathumthani, Thailand
- Center of Excellence in Digestive Diseases, Thammasat University, Thailand Science Research and Innovation Fundamental Fund, Bualuang ASEAN Chair Professorship at Thammasat University, Khlong Nueng 12121, Pathumthani, Thailand
- Department of Medicine, Chulabhorn International College of Medicine (CICM), Thammasat University, Khlong Nueng 12121, Pathumthani, Thailand
- Division of Gastroentero-Hepatology, Department of Internal Medicine, Faculty of Medicine, Dr. Soetomo Teaching Hospital, Universitas Airlangga, Surabaya 60286, Indonesia
| | - Muhammad Miftahussurur
- Helicobacter pylori and Microbiota Study Group, Institute of Tropical Disease, Universitas Airlangga, Surabaya 60286, Indonesia
- Division of Gastroentero-Hepatology, Department of Internal Medicine, Faculty of Medicine, Dr. Soetomo Teaching Hospital, Universitas Airlangga, Surabaya 60286, Indonesia
| | - Yoshio Yamaoka
- Department of Environmental and Preventive Medicine, Faculty of Medicine, Oita University, Oita 879-5593, Japan
- Division of Gastroentero-Hepatology, Department of Internal Medicine, Faculty of Medicine, Dr. Soetomo Teaching Hospital, Universitas Airlangga, Surabaya 60286, Indonesia
- The Research Center for GLOBAL and LOCAL Infectious Diseases (RCGLID), Oita University, Oita 870-1192, Japan
- Department of Medicine, Gastroenterology and Hepatology Section, Baylor College of Medicine, Houston, TX 77030, USA
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Jafar M, Sajjad Ahmad Khan M, Salahuddin M, Zahoor S, Mohammed Hesham Slais H, Ibrahim Alalwan L, Radhi Alshaban H. DEVELOPMENT OF APIGENIN LOADED GASTRORETENTIVE MICROSPONGE FOR THE TARGETING OF HELICO BACTER PYLORI. Saudi Pharm J 2023; 31:659-668. [PMID: 37181149 PMCID: PMC10172626 DOI: 10.1016/j.jsps.2023.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 03/07/2023] [Indexed: 03/18/2023] Open
Abstract
The goal of the present work was to invent an apigenin-stacked gastroretentive microsponge to target H. pylori. The quasi-emulsion technique was used to prepare microsponges, which were then tested for various physicochemical properties, in-vivo gastric retention, and in-vitro anti-H. pylori study. The microsponge that demonstrated a comparatively good product yield (76.23 ± 0.84), excellent entrapment efficiency (97.84 ± 0.85), sustained in-vitro gastric retention period, and prolonged drug release were chosen for further investigations. The microsponge's SEM analysis showed that it had a spherical form, porous surface, and interconnected spaces. No drug-polymer interactions were detected in the FTIR investigation. Apigenin was found to be dispersed in the microsponge's polymeric matrix according to DSC & XRD investigations. Moreover, the microsponge in the rat's stomach floated for 4 h, according to the ultrasonography. The antibacterial activity of apigenin against H. pylori was nearly two folds more than the pure apigenin and had a more sustained release in the best microsponge, according to the in vitro MIC data, when compared to pure apigenin. To sum up, the developed gastroretentive microsponge with apigenin offers a viable alternative for the efficient targeting of H. pylori. But more preclinical & clinical studies of our best microsponge would yield considerably more fruitful results.
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Ansari S, Yamaoka Y. Helicobacter pylori Infection, Its Laboratory Diagnosis, and Antimicrobial Resistance: a Perspective of Clinical Relevance. Clin Microbiol Rev 2022; 35:e0025821. [PMID: 35404105 PMCID: PMC9491184 DOI: 10.1128/cmr.00258-21] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Despite the recent decrease in overall prevalence of Helicobacter pylori infection, morbidity and mortality rates associated with gastric cancer remain high. The antimicrobial resistance developments and treatment failure are fueling the global burden of H. pylori-associated gastric complications. Accurate diagnosis remains the opening move for treatment and eradication of infections caused by microorganisms. Although several reports have been published on diagnostic approaches for H. pylori infection, most lack the data regarding diagnosis from a clinical perspective. Therefore, we provide an intensive, comprehensive, and updated description of the currently available diagnostic methods that can help clinicians, infection diagnosis professionals, and H. pylori researchers working on infection epidemiology to broaden their understanding and to select appropriate diagnostic methods. We also emphasize appropriate diagnostic approaches based on clinical settings (either clinical diagnosis or mass screening), patient factors (either age or other predisposing factors), and clinical factors (either upper gastrointestinal bleeding or partial gastrectomy) and appropriate methods to be considered for evaluating eradication efficacy. Furthermore, to cope with the increasing trend of antimicrobial resistance, a better understanding of its emergence and current diagnostic approaches for resistance detection remain inevitable.
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Affiliation(s)
- Shamshul Ansari
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu City, Oita, Japan
| | - Yoshio Yamaoka
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu City, Oita, Japan
- Department of Medicine, Gastroenterology and Hepatology Section, Baylor College of Medicine, Houston, Texas, USA
- Institute of Tropical Disease, Universitas Airlangga, Surabaya, Indonesia
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Kouhsari E, Sadeghifard N, Khadiv A, Sayadi H, Amiriani T, Ghafourian S, Valadbeigi H, Krutova M. Heteroresistance to clarithromycin and metronidazole in patients with a Helicobacter pylori infection: a systematic review and meta-analysis. Ann Clin Microbiol Antimicrob 2022; 21:19. [PMID: 35596211 PMCID: PMC9123761 DOI: 10.1186/s12941-022-00509-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Accepted: 04/29/2022] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Antimicrobial resistance of H. pylori can lead to treatment failure. Importantly, several studies have reported on heteroresistance, i.e. the presence of resistant and susceptible H. pylori populations in the same sample and/or a difference in the susceptibility patterns between biopsy samples. This meta-analysis aims to provide comprehensive data on the prevalence of metronidazole and clarithromycin heteroresistance and the approaches to their detection. MATERIAL AND METHODS A systematic review was performed after the search of MEDLINE, Scopus and Web of Science. The study outcomes were the weighted pooled prevalence of heteroresistance to clarithromycin and metronidazole in H. pylori positive samples and/or isolates with a subanalysis by continent. RESULTS A total of 22 studies that had investigated 3852 H. pylori positive patients were included in the meta-analysis. Heteroresistance to clarithromycin was reported in 20 studies, with a weighted pooled prevalence of 6.8% (95% CI 5.1-8.6; 3654 H. pylori positive patients; the substantial heterogeneity I2 = 55.6%). Heteroresistance to metronidazole was reported in 12 studies, with a weighted pooled prevalence of 13.8% (95% CI 8.9-18.6; 1670 H. pylori positive patients; the substantial heterogeneity I2 = 60.9%). The weighted pooled prevalence of clarithromycin heteroresistance was similar in Asia and Europe (p = 0.174584), however, metronidazole heteroresistance was detected more often in Europe (p < 0.00001). Clarithromycin heteroresistance was detected more often by phenotype rather than by using genotyping methods (12 vs 8 studies), whereas heteroresistance to metronidazole was detected only by phenotype. CONCLUSION The prevalence of heteroresistance to clarithromycin and/or metronidazole is not negligible and can be detected in approximately 7 and 14% of H. pylori positive samples, respectively. These findings highlight the need to raise the awareness of gastroenterologists and microbiologists to the heteroresistance to clarithromycin and metronidazole in patients with a H. pylori infection.
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Affiliation(s)
- Ebrahim Kouhsari
- Laboratory Sciences Research Centre, Golestan University of Medical Sciences, Gorgan, Iran
| | - Nourkhoda Sadeghifard
- Clinical Microbiology Research Centre, Ilam University of Medical Sciences, Ilam, Iran
| | - Arezoo Khadiv
- Clinical Microbiology Research Centre, Ilam University of Medical Sciences, Ilam, Iran.,Department of Microbiology, Faculty of Medicine, Ilam University of Medical Sciences, Ilam, Iran
| | - Hojjat Sayadi
- Non-Communicable Diseases Research Centre, Ilam University of Medical Sciences, Ilam, Iran
| | - Taghi Amiriani
- Golestan Research Center of Gastroenterology and Hepatology, Golestan University of Medical Sciences, Gorgan, Iran
| | - Sobhan Ghafourian
- Clinical Microbiology Research Centre, Ilam University of Medical Sciences, Ilam, Iran.,Department of Microbiology, Faculty of Medicine, Ilam University of Medical Sciences, Ilam, Iran
| | - Hassan Valadbeigi
- Clinical Microbiology Research Centre, Ilam University of Medical Sciences, Ilam, Iran.
| | - Marcela Krutova
- Department of Medical Microbiology, Charles University, 2nd Faculty of Medicine and Motol University Hospital, Prague, Czech Republic
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Meng F, Tao H, Mi Y, Yang T, Wang X, Go Y, Lin Y, Wang G. Nanocluster-mediated photothermia improves eradication efficiency and antibiotic sensitivity of Helicobacter pylori. Cancer Nanotechnol 2022. [DOI: 10.1186/s12645-022-00121-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Helicobacter pylori (H. pylori) eradication plays a crucial role in gastric cancer prevention, but the antimicrobial resistance of H. pylori is obstructing this elimination process. In this study, we developed nanoclusters (NCs) from Zn0.3Fe2.7O4 nanoparticles using a poly(ethylene glycol)-b-poly(ε-caprolactone)-based nanocarrier as an innovative antibiotic-independent H. pylori management.
Results
The nanocluster showed minimal toxicity and maximal biocompatibility. With a low concentration (50 µg/mL) of NCs under a short time period (~ 2 min) of near-infrared (808 nm) irradiation, we kept the culture medium temperature to 41 °C for 20 min with continuous irradiation. The heated NCs exhibited efficient photothermal effects and resulted in an excellent inhibition of H. pylori growth, adhesion and ability to induce vacuolization in eukaryotic cells in in vitro investigation. Transmission electron microscopy showed a dramatic morphologic change after NCs photothermia on H. pylori, including cell wall and membrane rupture, as well as ribosome damage. Besides, levofloxacin and clarithromycin resistance was decreased after photothermal treatment in H. pylori NCTC 11637 and/or clinical strains, however metronidazole resistance was unchanged. We also discovered a significant decrease in the biofilm formation of H. pylori under the NCs-based photothermal application, while efflux pump function was unchanged.
Conclusions
Based on this novel NCs-based photothermal approach, we were able to demonstrate in vitro a significant inhibition of both H. pylori growth and molecular toxicity, and its improvement in antibiotic sensitivity alone with the eradication of H. pylori biofilms previously believed to be tolerant to conventional antibiotics.
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Liu Y, Yang F, Wang S, Chi W, Ding L, Liu T, Zhu F, Ji D, Zhou J, Fang Y, Zhang J, Xiang P, Zhang Y, Zhao H. HopE and HopD Porin-Mediated Drug Influx Contributes to Intrinsic Antimicrobial Susceptibility and Inhibits Streptomycin Resistance Acquisition by Natural Transformation in Helicobacter pylori. Microbiol Spectr 2022; 10:e0198721. [PMID: 35234510 PMCID: PMC9045298 DOI: 10.1128/spectrum.01987-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 01/21/2022] [Indexed: 12/14/2022] Open
Abstract
Helicobacter pylori is a human pathogen competent for natural transformation. Intrinsic and acquired antibiotic resistance contribute to the survival and multiplication of H. pylori under antibiotics. While drug-resistance dissemination by natural transformation (NT)-mediated horizontal gene transfer remains poorly understood in H. pylori. The purpose of the study was to investigate the role of H. pylori porins (HopA, HopB, HopC, HopD, and HopE) in the intrinsic antibiotic resistance and to preliminarily reveal the potential effect of HopE and HopD porins in streptomycin resistance acquisition after NT in the presence of antibiotics. Using traditional antibiotic susceptibility tests and growth curve analysis, we found the MIC values of metronidazole, clarithromycin, levofloxacin, tetracycline, rifampin, and streptomycin in mutants lacking HopE and/or HopD were significantly elevated compare to those in wild-type strain. The quantitative analysis of the tetramethyl rhodamine isothiocyanate (TRITC)-labeled streptomycin accumulation at the single-cell level showed reduced streptomycin intracellular fluorescence in ΔhopE and ΔhopD mutant cells. Furthermore, in the presence of translation-inhibiting antibiotic streptomycin, the resistance acquisition frequency was decreased in the wild-type strain, which could be reversed by mutants lacking HopE and HopD that restored relatively high resistance acquisition frequencies. By transforming a pUC19-rpsLmut-sfgfp linear plasmid carrying a streptomycin conferring mutation, we observed that the impaired ability of rpsLmut synthesis in the wild-type strain was restored in the ΔhopE and ΔhopD mutant transformants. Our study revealed that in the presence of streptomycin, resistance acquisition at least partially relied on the deletion of the hopE and hopD genes, because their loss reduced streptomycin concentration in the cell and thus restored the expression of the resistance-conferring gene, which was inhibited by streptomycin in wild-type strain. The loss of HopE and HopD influx activity may also preserve resistance acquisition by transformation in the presence of antibiotics with other modes of action. IMPORTANCE Helicobacter pylori is constitutively competent for natural transformation (NT) and possesses an efficient system for homologous recombination, which could be utilized to study the NT-mediated horizontal gene transfer induced antibiotic resistance acquisition. Bacterial porins have drawn renewed attention because of their crucial role in antibiotic susceptibility. From the perspective of porin-mediated influx in H. pylori, our study preliminarily revealed the important role of HopE and HopD porins not only in preserving the intrinsic susceptibility to specific antibiotic but also in evading acquired antibiotic resistance by NT in the presence of translation-inhibiting antimicrobial. Therefore, the loss of HopE or HopD porin in H. pylori genomes, combined with the large number of secreted or cell-free genetic elements carrying mutations conferring antibiotic resistance, may raise the possibility that this mechanism plays a potential role in the propagation of antibiotic resistance within H. pylori communities.
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Affiliation(s)
- Yixin Liu
- Department of Laboratory Medicine, Huadong Hospital, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Clinical Geriatric Medicine, Shanghai, China
- Research Center on Aging and Medicine, Fudan University, Shanghai, China
| | - Feng Yang
- Department of Laboratory Medicine, Huadong Hospital, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Clinical Geriatric Medicine, Shanghai, China
- Research Center on Aging and Medicine, Fudan University, Shanghai, China
| | - Su Wang
- Department of Laboratory Medicine, Huadong Hospital, Fudan University, Shanghai, China
| | - Wenjing Chi
- Department of Laboratory Medicine, Huadong Hospital, Fudan University, Shanghai, China
| | - Li Ding
- Department of Laboratory Medicine, Huadong Hospital, Fudan University, Shanghai, China
| | - Tao Liu
- Department of Laboratory Medicine, Huadong Hospital, Fudan University, Shanghai, China
| | - Feng Zhu
- Department of Laboratory Medicine, Huadong Hospital, Fudan University, Shanghai, China
| | - Danian Ji
- Department of Endoscopy, Huadong Hospital, Fudan University, Shanghai, China
| | - Jun Zhou
- Department of Endoscopy, Huadong Hospital, Fudan University, Shanghai, China
| | - Yi Fang
- Department of Laboratory Medicine, Huadong Hospital, Fudan University, Shanghai, China
| | - Jinghao Zhang
- Department of Laboratory Medicine, Huadong Hospital, Fudan University, Shanghai, China
| | - Ping Xiang
- Department of Endoscopy, Huadong Hospital, Fudan University, Shanghai, China
| | - Yanmei Zhang
- Department of Laboratory Medicine, Huadong Hospital, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Clinical Geriatric Medicine, Shanghai, China
- Research Center on Aging and Medicine, Fudan University, Shanghai, China
| | - Hu Zhao
- Department of Laboratory Medicine, Huadong Hospital, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Clinical Geriatric Medicine, Shanghai, China
- Research Center on Aging and Medicine, Fudan University, Shanghai, China
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10
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Sharndama HC, Mba IE. Helicobacter pylori: an up-to-date overview on the virulence and pathogenesis mechanisms. Braz J Microbiol 2022; 53:33-50. [PMID: 34988937 PMCID: PMC8731681 DOI: 10.1007/s42770-021-00675-0] [Citation(s) in RCA: 64] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 12/24/2021] [Indexed: 02/06/2023] Open
Abstract
Helicobacter pylori is an organism associated with ulcer disease and gastric cancer. The latter is one of the most prevalent malignancies and currently the fourth major cause of cancer-related deaths globally. The pathogen infects about 50% of the world population, and currently, no treatment ensures its total elimination. There has been an increase in our understanding of the pathophysiology and pathogenesis mechanisms of H. pylori over the years. H. pylori can induce several genetic alterations, express numerous virulence factors, and trigger diverse adaptive mechanisms during its adherence and colonization. For successful colonization and infection establishment, several effector proteins/toxins are released by the organism. Evidence is also available reporting spiral to coccoid transition as a unique tactic H. pylori uses to survive in the host's gastrointestinal tract (GIT). Thus, the virulence and pathogenicity of H. pylori are under the control of complex interplay between the virulence factors, host, and environmental factors. Expounding the role of the various virulence factors in H. pylori pathogenesis and clinical outcomes is crucial for vaccine development and in providing and developing a more effective therapeutic intervention. Here we critically reflect on H. pylori infection and delineate what is currently known about the virulence and pathogenesis mechanisms of H. pylori.
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Affiliation(s)
| | - Ifeanyi Elibe Mba
- Department of Microbiology, University of Nigeria, Nsukka, Enugu, Nigeria.
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11
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Genetic and Transcriptomic Variations for Amoxicillin Resistance in Helicobacter pylori under Cryopreservation. Pathogens 2021; 10:pathogens10060676. [PMID: 34070823 PMCID: PMC8229390 DOI: 10.3390/pathogens10060676] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 05/02/2021] [Accepted: 05/27/2021] [Indexed: 11/17/2022] Open
Abstract
Some amoxicillin-resistant strains of H. pylori show a sharp decrease in amoxicillin resistance after freezing. In China, most clinical gastric mucosal specimens are frozen and transported for isolation and drug susceptibility testing for H. pylori, which may lead to an underestimation of the amoxicillin resistance. The objective of this study is to investigated reasons for the decreased amoxicillin resistance after cryopreservation. A high-level amoxicillin-resistant clone (NX24r) was obtained through amoxicillin pressure screening. After cryopreservation at -80 °C for 3 months, the minimum inhibitory concentration (MIC) of NX24r was reduced sharply. Mutations and changes of transcriptome were analyzed after amoxicillin screening and cryopreservation. Mutations in PBP1 (I370T, E428K, T556S) and HefC (M337K, L378F, D976V) were detected in NX24r, which may be the main reason for the induced amoxicillin resistance. No mutations were found in PBP1 or HefC after cryopreservation. However, transcriptome analysis showed that down-regulated genes in the cryopreserved clone were significantly enriched in plasma membrane (GO:0005886), including lepB, secD, gluP, hp0871 and hp1071. These plasma membrane genes are involved in the biosynthesis and transport function of the membrane. The decreased amoxicillin resistance after cryopreservation may be related to the down-regulation of genes involved in membrane structure and transport function.
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12
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FBPAII and rpoBC, the Two Novel Secreted Proteins Identified by the Proteomic Approach from a Comparative Study between Antibiotic-Sensitive and Antibiotic-Resistant Helicobacter pylori-Associated Gastritis Strains. Infect Immun 2021; 89:IAI.00053-21. [PMID: 33782154 DOI: 10.1128/iai.00053-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 03/17/2021] [Indexed: 11/20/2022] Open
Abstract
Helicobacter pylori infection is the leading cause of chronic gastritis, which can develop into gastric cancer. Eliminating H. pylori infection with antibiotics achieves the prevention of gastric cancer. Currently, the prevalence of H. pylori resistance to clarithromycin and metronidazole, and the dual resistance to metronidazole and clarithromycin (C_R, M_R, and C/M_R, respectively), remains at a high level worldwide. As a means of exploring new candidate proteins for the management of H. pylori infection, secreted proteins from antibiotic-susceptible and antibiotic-resistant H. pylori-associated gastritis strains were obtained by in-solution tryptic digestion coupled with nano-liquid chromatography tandem mass spectrometry (nano-LC-MS/MS). A total of 583, 582, 590, and 578 differential expressed proteins were identified from C_R, M_R, C/M_R, and antibiotic-sensitive strain (S_S) samples, respectively. Of these, 23 overlapping proteins were found by Venn diagram analysis. Based on heat map analyses, the most and least differing protein expressions were observed from C/M_R strains and S_S strains, respectively. Of the proteins secreted by the S_S strain, only nine were found. After predicting the protein interaction with metronidazole and clarithromycin via the STITCH database, the two most interesting proteins were found to be rpoBC and FBPAII. After quantitative real-time reverse transcription PCR (qRT-PCR) analysis, a downregulation of rpoB from M_R strains was observed, suggesting a relationship of rpoB to metronidazole sensitivity. Inversely, an upregulation of fba from C_R, M_R, and C/M_R strains was noticed, suggesting the paradoxical expression of FBPAII and the fba gene. This report is the first to demonstrate the association of these two novel secreted proteins, namely, rpoBC and FBPAII, with antibiotic-sensitive H. pylori -associated gastritis strains.
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13
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Saracino IM, Pavoni M, Zullo A, Fiorini G, Lazzarotto T, Borghi C, Vaira D. Next Generation Sequencing for the Prediction of the Antibiotic Resistance in Helicobacter pylori: A Literature Review. Antibiotics (Basel) 2021; 10:437. [PMID: 33919811 PMCID: PMC8070836 DOI: 10.3390/antibiotics10040437] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/08/2021] [Accepted: 04/13/2021] [Indexed: 12/12/2022] Open
Abstract
Background and aims: Only a few antimicrobials are effective against H. pylori, and antibiotic resistance is an increasing problem for eradication therapies. In 2017, the World Health Organization categorized clarithromycin resistant H. pylori as a "high-priority" bacterium. Standard antimicrobial susceptibility testing can be used to prescribe appropriate therapies but is currently recommended only after the second therapeutic failure. H. pylori is, in fact, a "fastidious" microorganism; culture methods are time-consuming and technically challenging. The advent of molecular biology techniques has enabled the identification of molecular mechanisms underlying the observed phenotypic resistance to antibiotics in H. pylori. The aim of this literature review is to summarize the results of original articles published in the last ten years, regarding the use of Next Generation Sequencing, in particular of the whole genome, to predict the antibiotic resistance in H. pylori.Methods: a literature research was made on PubMed. The research was focused on II and III generation sequencing of the whole H. pylori genome. Results: Next Generation Sequencing enabled the detection of novel, rare and complex resistance mechanisms. The prediction of resistance to clarithromycin, levofloxacin and amoxicillin is accurate; for other antimicrobials, such as metronidazole, rifabutin and tetracycline, potential genetic determinants of the resistant status need further investigation.
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Affiliation(s)
- Ilaria Maria Saracino
- Microbiology Unit, Department of Specialized, Experimental, and Diagnostic Medicine, IRCCS St. Orsola Polyclinic, University of Bologna, 40138 Bologna, Italy; (I.M.S.); (T.L.)
| | - Matteo Pavoni
- Department of Medical and Surgical Sciences, IRCCS St. Orsola Polyclinic, University of Bologna, 40138 Bologna, Italy; (M.P.); (G.F.); (C.B.)
| | - Angelo Zullo
- Gastroenterology and Digestive Endoscopy, ‘Nuovo Regina Margherita’ Hospital, 00153 Rome, Italy;
| | - Giulia Fiorini
- Department of Medical and Surgical Sciences, IRCCS St. Orsola Polyclinic, University of Bologna, 40138 Bologna, Italy; (M.P.); (G.F.); (C.B.)
| | - Tiziana Lazzarotto
- Microbiology Unit, Department of Specialized, Experimental, and Diagnostic Medicine, IRCCS St. Orsola Polyclinic, University of Bologna, 40138 Bologna, Italy; (I.M.S.); (T.L.)
| | - Claudio Borghi
- Department of Medical and Surgical Sciences, IRCCS St. Orsola Polyclinic, University of Bologna, 40138 Bologna, Italy; (M.P.); (G.F.); (C.B.)
| | - Dino Vaira
- Department of Medical and Surgical Sciences, IRCCS St. Orsola Polyclinic, University of Bologna, 40138 Bologna, Italy; (M.P.); (G.F.); (C.B.)
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14
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Liang CM, Tai WC, Hsu PI, Wu DC, Kuo CH, Tsay FW, Lee CL, Chen KY, Chuah SK. Trend of changes in antibiotic resistance in Helicobacter pylori from 2013 to 2019: a multicentre report from Taiwan. Therap Adv Gastroenterol 2020; 13:1756284820976990. [PMID: 33354229 PMCID: PMC7734532 DOI: 10.1177/1756284820976990] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 11/03/2020] [Indexed: 02/04/2023] Open
Abstract
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.
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Affiliation(s)
- Chih-Ming Liang
- Division of Hepatogastroenterology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung
| | - Wei-Chen Tai
- Division of Hepatogastroenterology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung
- Chang Gung University College of Medicine, Taoyuan City
| | - Pin-I Hsu
- Department of Medicine, An Nan Hospital, China Medical University
| | - Deng-Chyang Wu
- Department of Internal Medicine, Division of Gastroenterology, Kaohsiung Medical University Hospital, Kaohsiung
| | - Chao-Hung Kuo
- Department of Internal Medicine, Division of Gastroenterology, Kaohsiung Medical University Hospital, Kaohsiung
| | - Feng-Woey Tsay
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, Kaohsiung Veterans General Hospital, Kaohsiung
| | - Chia-Long Lee
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, Cathay General Hospital, Taipei
| | - Kuan-Yang Chen
- Department of Gastroenterology, Taipei City Hospital, 10, Section 4, Ren’ai Road, Da’an District 106, Taipei
| | - Seng-Kee Chuah
- Division of Hepatogastroenterology, Kaohsiung Chang Gung Memorial Hospital, 123, Ta-Pei Road, Niao-Sung Hsiang, Kaohsiung, 833 Chang Gung University College of Medicine, Taoyuan City
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15
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Huang TH, Yang SC, Tai WC, Liang CM, Kuo CM, Yao CC, Wu CK, Kuo YH, Chou YP, Lee CH, Wu KL, Chuah SK. The efficacies of non-bismuth containing quadruple therapies in the treatment of first-line anti-Helicobacter pylori across 4-year time interval with changing antibiotics resistance. Biomed J 2020; 44:S275-S281. [PMID: 35292265 PMCID: PMC9068570 DOI: 10.1016/j.bj.2020.11.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 11/18/2020] [Accepted: 11/22/2020] [Indexed: 02/07/2023] Open
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16
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Huang L, Feng Y, Zong Z. Heterogeneous resistance to colistin in Enterobacter cloacae complex due to a new small transmembrane protein. J Antimicrob Chemother 2020; 74:2551-2558. [PMID: 31169899 DOI: 10.1093/jac/dkz236] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 04/28/2019] [Accepted: 05/05/2019] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Enterobacter strains can display heterogeneous resistance (heteroresistance) to colistin but the mechanisms remain largely unknown. We investigated potential mechanisms of colistin heteroresistance in an Enterobacter clinical strain, WCHECl-1060, and found a new mechanism. METHODS Strain WCHECl-1060 was subjected to WGS to identify known colistin resistance mechanisms. Tn5 insertional mutagenesis, gene knockout and complementation and shotgun cloning were employed to investigate unknown colistin heteroresistance mechanisms. RNA sequencing was performed to link the newly identified mechanism with known ones. RESULTS We showed that the phoP gene [encoding part of the PhoP-PhoQ two-component system (TCS)], the dedA(Ecl) gene (encoding an inner membrane protein of the DedA family) and the tolC gene (encoding part of the AcrAB-TolC efflux pump) are required for colistin heteroresistance. We identified a new gene, ecr, encoding a 72 amino acid transmembrane protein, which was able to mediate colistin heteroresistance. We then performed RNA sequencing and transcriptome analysis and found that in the presence of ecr the expression of phoP and the arnBCADTEF operon, which synthesizes and transfers l-Ara4N to lipid A, was increased significantly. CONCLUSIONS The small protein encoded by ecr represents a new colistin heteroresistance mechanism and is likely to mediate colistin heteroresistance via the PhoP-PhoQ TCS to act on the arnBCADTEF operon.
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Affiliation(s)
- Liang Huang
- Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, China.,Public Health Clinical Center of Chengdu, Chengdu, China
| | - Yu Feng
- Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, China.,Division of Infectious Diseases, State Key Laboratory of Biotherapy, Chengdu, China
| | - Zhiyong Zong
- Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, China.,Division of Infectious Diseases, State Key Laboratory of Biotherapy, Chengdu, China.,Department of Infection Control, West China Hospital, Sichuan University, Chengdu, China
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17
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Cai Y, Wang C, Chen Z, Xu Z, Li H, Li W, Sun Y. Transporters HP0939, HP0497, and HP0471 participate in intrinsic multidrug resistance and biofilm formation in Helicobacter pylori by enhancing drug efflux. Helicobacter 2020; 25:e12715. [PMID: 32548895 DOI: 10.1111/hel.12715] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 05/17/2020] [Accepted: 05/26/2020] [Indexed: 02/06/2023]
Abstract
BACKGROUND The multidrug resistance of Helicobacter pylori is becoming an increasingly serious issue. It is therefore necessary to study the mechanism of multidrug resistance of H pylori. We have previously identified that the HP0939, HP0497, and HP0471 transporters affect the efflux of drugs from H pylori. As efflux pumps participate in bacterial multidrug resistance and biofilm formation, we hypothesized that these transporters could be involved in the multidrug resistance and biofilm formation of H pylori. MATERIALS AND METHODS We therefore constructed three knockout strains, Δhp0939, Δhp0497, and Δhp0471, and three high-expression strains, Hp0939he , Hp0497he , and Hp0471he , using the wild-type (WT) 26 695 strain of H pylori as the template. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of wild strains, knockout strains, and high-expression strains to amoxicillin, metronidazole, and other antibiotics were measured. The efflux capacity of high-expression strains and wild strains was compared by Hoechst 33 342 accumulation assay. RESULTS Determination of the MIC and MBC of the antibiotics revealed that the knockout strains were more sensitive to antibiotics, while the high-expression strains were less sensitive to antibiotics, compared to the WT. The ability of the high-expression strains to efflux drugs was significantly higher than that of the WT. We also induced H pylori to form biofilms, and observed that the knockout strains could barely form biofilms and were more sensitive to several antibiotics, compared to the WT. The mRNA expression of hp0939, hp0497, and hp0471 in the clinically sensitive and multidrug-resistant strains was determined, and it was found that these genes were highly expressed in the multidrug-resistant strains that were isolated from the clinics. CONCLUSIONS In this study, we found three transporters involved in intrinsic multidrug resistance of H pylori.
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Affiliation(s)
- Yuying Cai
- Department of Microbiology, Key Laboratory of Medical Microbiology and Parasitology, Guizhou Medical University, Guiyang, China.,Institute of Pathogen Biology, School of Basic Medical Sciences, Shandong University, Jinan, China
| | - Caixia Wang
- Department of Microbiology, Key Laboratory of Medical Microbiology and Parasitology, Guizhou Medical University, Guiyang, China.,Institute of Pathogen Biology, School of Basic Medical Sciences, Shandong University, Jinan, China
| | - Zhenghong Chen
- Department of Microbiology, Key Laboratory of Medical Microbiology and Parasitology, Guizhou Medical University, Guiyang, China
| | - Zhengzheng Xu
- Department of Microbiology, Key Laboratory for Experimental Teratology of Ministry of Education, Key Laboratory of Infection and Immunology of Shandong Province, School of Basic Medicine, Shandong University, Jinan, China
| | - Huanjie Li
- Department of Microbiology, Key Laboratory for Experimental Teratology of Ministry of Education, Key Laboratory of Infection and Immunology of Shandong Province, School of Basic Medicine, Shandong University, Jinan, China
| | - Wenjuan Li
- Department of Microbiology, Key Laboratory for Experimental Teratology of Ministry of Education, Key Laboratory of Infection and Immunology of Shandong Province, School of Basic Medicine, Shandong University, Jinan, China
| | - Yundong Sun
- Department of Microbiology, Key Laboratory for Experimental Teratology of Ministry of Education, Key Laboratory of Infection and Immunology of Shandong Province, School of Basic Medicine, Shandong University, Jinan, China
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18
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Marques AT, Vítor JMB, Santos A, Oleastro M, Vale FF. Trends in Helicobacter pylori resistance to clarithromycin: from phenotypic to genomic approaches. Microb Genom 2020; 6:e000344. [PMID: 32118532 PMCID: PMC7200067 DOI: 10.1099/mgen.0.000344] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 02/10/2020] [Indexed: 12/15/2022] Open
Abstract
For a long time Helicobacter pylori infections have been treated using the macrolide antibiotic, clarithromycin. Clarithromycin resistance is increasing worldwide and is the most common cause of H. pylori treatment failure. Here we review the mechanisms of antibiotic resistance to clarithromycin, detailing the individual and combinations of point mutations found in the 23S rRNA gene associated with resistance. Additionally, we consider the methods used to detect clarithromycin resistance, emphasizing the use of high-throughput next-generation sequencing methods, which were applied to 17 newly sequenced pairs of H. pylori strains isolated from the antrum and corpus of a recent colonized paediatric population. This set of isolates was composed of six pairs of resistant strains whose phenotype was associated with two point mutations found in the 23S rRNA gene: A2142C and A2143G. Other point mutations were found simultaneously in the same gene, but, according to our results, it is unlikely that they contribute to resistance. Further, among susceptible isolates, genomic variations compatible with mutations previously associated with clarithromycin resistance were detected. Exposure to clarithromycin may select low-frequency variants, resulting in a progressive increase in the resistance rate due to selection pressure.
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Affiliation(s)
- Andreia T. Marques
- Host–Pathogen Interactions Unit, Research Institute for Medicines (iMed-ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisboa, Portugal
| | - Jorge M. B. Vítor
- Host–Pathogen Interactions Unit, Research Institute for Medicines (iMed-ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisboa, Portugal
- Department of Biochemistry and Human Biology, Faculty of Pharmacy, Universidade de Lisboa, 1649 003 Lisbon, Portugal
| | - Andrea Santos
- National Reference Laboratory for Gastrointestinal Infections, Department of Infectious Diseases, National Institute of Health Dr Ricardo Jorge, Lisbon, Portugal
| | - Mónica Oleastro
- National Reference Laboratory for Gastrointestinal Infections, Department of Infectious Diseases, National Institute of Health Dr Ricardo Jorge, Lisbon, Portugal
| | - Filipa F. Vale
- Host–Pathogen Interactions Unit, Research Institute for Medicines (iMed-ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisboa, Portugal
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Lamut A, Peterlin Mašič L, Kikelj D, Tomašič T. Efflux pump inhibitors of clinically relevant multidrug resistant bacteria. Med Res Rev 2019; 39:2460-2504. [PMID: 31004360 DOI: 10.1002/med.21591] [Citation(s) in RCA: 109] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 03/31/2019] [Accepted: 04/02/2019] [Indexed: 12/29/2022]
Abstract
Bacterial infections are an increasingly serious issue worldwide. The inability of existing therapies to treat multidrug-resistant pathogens has been recognized as an important challenge of the 21st century. Efflux pumps are important in both intrinsic and acquired bacterial resistance and identification of small molecule efflux pump inhibitors (EPIs), capable of restoring the effectiveness of available antibiotics, is an active research field. In the last two decades, much effort has been made to identify novel EPIs. However, none of them has so far been approved for therapeutic use. In this article, we explore different structural families of currently known EPIs for multidrug resistance efflux systems in the most extensively studied pathogens (NorA in Staphylococcus aureus, AcrAB-TolC in Escherichia coli, and MexAB-OprM in Pseudomonas aeruginosa). Both synthetic and natural compounds are described, with structure-activity relationship studies and optimization processes presented systematically for each family individually. In vitro activities against selected test strains are presented in a unifying manner for all the EPIs described, together with the most important toxicity, pharmacokinetic and in vivo efficacy data. A critical evaluation of lead-likeness characteristics and the potential for clinical development of the most promising inhibitors of the three efflux systems is described. This overview of EPIs is a good starting point for the identification of novel effective antibacterial drugs.
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Affiliation(s)
- Andraž Lamut
- Chair of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
| | - Lucija Peterlin Mašič
- Chair of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
| | - Danijel Kikelj
- Chair of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
| | - Tihomir Tomašič
- Chair of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
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20
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Hashemi SJ, Sheikh AF, Goodarzi H, Yadyad MJ, Seyedian SS, Aslani S, Assarzadegan MA. Genetic basis for metronidazole and clarithromycin resistance in Helicobacter pylori strains isolated from patients with gastroduodenal disorders. Infect Drug Resist 2019; 12:535-543. [PMID: 30881059 PMCID: PMC6404679 DOI: 10.2147/idr.s192942] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND The aim of this study was to evaluate the antimicrobial resistance and genetic basis for metronidazole (Mtz) and clarithromycin (Cla) resistance in strains of Helicobacter pylori, isolated from patients with gastroduodenal disorders. PATIENTS AND METHODS A total of 157 H. pylori isolates (from 22 gastric cancer, 38 peptic ulcer disease, and 97 non-ulcer dyspepsia patients) were analyzed for drug susceptibility to Mtz and Cla, by gradient diffusion test (E-test, MAST). The PCR and sequence analysis of the rdxA and frxA for Mtz-resistant strains and the 23S rRNA for Cla-resistant strains were used to determine the genetic basis of drug resistance in H. pylori strains. Increased expression of TolC homologous genes (hefA) that upregulates efflux pump activity was determined in multidrug-resistant (MDR) strain of H. pylori by real-time PCR technique. RESULTS Among 157 H. pylori isolates, 32 (20.4%) strains were resistant to at least one of the antimicrobial agents. The highest resistance rate was attributed to Mtz (n=69, 43.94%). Among the resistant strains of H. pylori, 15 cases (9.55%) were detected as MDR. Mutations in the rdxA (85.5%) and A2143G point mutations (63.1%) in the 23S rRNA were the most common cause of resistance to Mtz and Cla in strains of H. pylori, respectively. In MDR strains, the rdxA mutation and A2143G-point mutation in the 23S rRNA were the most abundant mutations responsible for drug resistance. The relative expression of hefA in MDR strains (mean 3.706) was higher than the susceptible strains (mean 1.07). CONCLUSION Mutational inactivation and efflux pump overexpression are two mechanisms that increase the resistance to H. pylori antimicrobial agents and the rate of MDR strains. In Iran, the mutations of rdxA and frxA in Mtz-resistant strains and A2143G and A2142G of the 23S rRNA in Cla-resistant strains were significant. The screening for these mutations could help to prevent antibiotic resistance, and to determine the most effective anti-H. pylori drugs.
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Affiliation(s)
- Seyed Jalal Hashemi
- Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran,
- Research Institute for Infectious Diseases of the Digestive System, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
- Division of Gastroenterology and Hepatology, Ahvaz Jundishapur University of Medical Sciences, Ahwaz, Iran
| | - Ahmad Farajzadeh Sheikh
- Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran,
- Department of Microbiology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran,
| | - Hamed Goodarzi
- Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran,
- Department of Microbiology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran,
- Molecular Biology Research Center, Baqiyatallah University of Medical Science, Tehran, Iran,
| | - Mohammad Jaafar Yadyad
- Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran,
| | - Seyed Saeid Seyedian
- Alimentary Tract Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Sajad Aslani
- Student Research Committee, Kerman University of Medical Sciences, Kerman, Iran
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21
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Genetic Determinants and Prediction of Antibiotic Resistance Phenotypes in Helicobacter pylori. J Clin Med 2019; 8:jcm8010053. [PMID: 30621024 PMCID: PMC6351930 DOI: 10.3390/jcm8010053] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 12/29/2018] [Accepted: 12/31/2018] [Indexed: 12/11/2022] Open
Abstract
Helicobacter pylori is a major human pathogen. Diagnosis of H. pylori infection and determination of its antibiotic susceptibility still mainly rely on culture and phenotypic drug susceptibility testing (DST) that is time-consuming and laborious. Whole genome sequencing (WGS) has recently emerged in medical microbiology as a diagnostic tool for reliable drug resistance prediction in bacterial pathogens. The aim of this study was to compare phenotypic DST results with the predictions based on the presence of genetic determinants identified in the H. pylori genome using WGS. Phenotypic resistance to clarithromycin, metronidazole, tetracycline, levofloxacin, and rifampicin was determined in 140 clinical H. pylori isolates by E-Test®, and the occurrence of certain single nucleotide polymorphisms (SNPs) in target genes was determined by WGS. Overall, there was a high congruence of >99% between phenotypic DST results for clarithromycin, levofloxacin, and rifampicin and SNPs identified in the 23S rRNA, gyrA, and rpoB gene. However, it was not possible to infer a resistance phenotype for metronidazole based on the occurrence of distinct SNPs in frxA and rdxA. All 140 H. pylori isolates analysed in this study were susceptible to tetracycline, which was in accordance with the absence of double or triple nucleotide substitutions in the 16S rRNA gene.
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Zanotti G, Cendron L. Structural Aspects of Helicobacter pylori Antibiotic Resistance. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1149:227-241. [PMID: 31016632 DOI: 10.1007/5584_2019_368] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Resistance to antibiotics of Helicobacter pylori infections is growing rapidly together with the need for more potent antimicrobials or novel strategies to recover the efficacy of the existing ones. Despite the main mechanisms according to which H. pylori acquires resistance are common to other microbial infections affecting humans, H. pylori has its own peculiarities, mostly due to the unique conditions experienced by the bacterium in the gastric niche. Possibly the most used of the antibiotics for H. pylori are those molecules that bind to the ribosome or to the DNA and RNA machinery, and in doing so they interfere with protein synthesis. Another important class is represented by molecules that binds to some enzyme essential for the bacterium survival, as in the case of enzymes involved in the bacterial wall biosynthesis. The mechanism used by the bacterium to fight antibiotics can be grouped in three classes: (i) mutations of some key residues in the protein that binds the inhibitor, (ii) regulation of the efflux systems or of the membrane permeability in order to reduce the uptake of the antibiotic, and (iii) other more complex indirect effects. Interestingly, the production of enzymes that degrade the antibiotics (as in the case of β-lactamases in many other bacteria) has not been clearly detected in H. pylori. The structural aspects of resistance players have not been object of extensive studies yet and the structure of very few H. pylori proteins involved in the resistance mechanisms are determined till now. Models of the proteins that play key roles in reducing antimicrobials susceptibility and their implications will be discussed in this chapter.
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Affiliation(s)
- Giuseppe Zanotti
- Department of Biomedical Sciences, University of Padua, Padua, Italy.
| | - Laura Cendron
- Department of Biology, University of Padua, Padua, Italy
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23
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Lin TF, Hsu PI. Second-line rescue treatment of Helicobacter pylori infection: Where are we now? World J Gastroenterol 2018; 24:4548-4553. [PMID: 30386104 PMCID: PMC6209570 DOI: 10.3748/wjg.v24.i40.4548] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 09/20/2018] [Accepted: 10/05/2018] [Indexed: 02/06/2023] Open
Abstract
At present, the best rescue therapy for Helicobacter pylori (H. pylori) infection following failure of first-line eradication remains unclear. The Maastricht V/Florence Consensus Report recommends bismuth quadruple therapy, or fluoroquinolone-amoxicillin triple/quadruple therapy as the second-line therapy for H. pylori infection. Meta-analyses have shown that bismuth quadruple therapy and levofloxacin-amoxicillin triple therapy have comparable eradication rates, while the former has more adverse effects than the latter. There are no significant differences between the eradication rates of levofloxacin-amoxicillin triple and quadruple therapies. However, the eradication rates of both levofloxacin-containing treatments are suboptimal. An important caveat of levofloxacin-amoxicillin triple or quadruple therapy is poor eradication efficacy in the presence of fluoroquinolone resistance. High-dose dual therapy is an emerging second-line therapy and has an eradication efficacy comparable with levofloxacin-amoxicillin triple therapy. Recently, a 10-d tetracycline-levofloxacin (TL) quadruple therapy comprised of a proton pump inhibitor, bismuth, tetracycline and levofloxacin has been developed, which achieves a markedly higher eradication rate compared with levofloxacin-amoxicillin triple therapy (98% vs 69%) in patients with failure of standard triple, bismuth quadruple or non-bismuth quadruple therapy. The present article reviews current second-line anti-H. pylori regimens and treatment algorisms. In conclusion, bismuth quadruple therapy, levofloxacin-amoxicillin triple/quadruple therapy, high-dose dual therapy and TL quadruple therapy can be used as second-line treatment for H. pylori infection. Current evidence suggests that 10-d TL quadruple therapy is a simple and effective regimen, and has the potential to become a universal rescue treatment following eradication failure by all first-line eradication regimens for H. pylori infection.
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Affiliation(s)
- Te-Fu Lin
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan
| | - Ping-I Hsu
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan
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24
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Bifunctional Enzyme SpoT Is Involved in Biofilm Formation of Helicobacter pylori with Multidrug Resistance by Upregulating Efflux Pump Hp1174 ( gluP). Antimicrob Agents Chemother 2018; 62:AAC.00957-18. [PMID: 30181372 PMCID: PMC6201075 DOI: 10.1128/aac.00957-18] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 08/22/2018] [Indexed: 02/06/2023] Open
Abstract
The drug resistance of Helicobacter pylori is gradually becoming a serious problem. Biofilm formation is an important factor that leads to multidrug resistance (MDR) in bacteria. The drug resistance of Helicobacter pylori is gradually becoming a serious problem. Biofilm formation is an important factor that leads to multidrug resistance (MDR) in bacteria. The ability of H. pylori to form biofilms on the gastric mucosa is known. However, there are few studies on the regulatory mechanisms of H. pylori biofilm formation and multidrug resistance. Guanosine 3′-diphosphate 5′-triphosphate and guanosine 3′,5′-bispyrophosphate [(p)ppGpp] are global regulatory factors and are synthesized in H. pylori by the bifunctional enzyme SpoT. It has been reported that (p)ppGpp is involved in the biofilm formation and multidrug resistance of various bacteria. In this study, we found that SpoT also plays an important role in H. pylori biofilm formation and multidrug resistance. Therefore, it was necessary to carry out some further studies regarding its regulatory mechanism. Considering that efflux pumps are of great importance in the biofilm formation and multidrug resistance of bacteria, we tried to determine whether efflux pumps controlled by SpoT participate in these activities. We found that Hp1174 (glucose/galactose transporter [gluP]), an efflux pump of the major facilitator superfamily (MFS), is highly expressed in biofilm-forming and multidrug-resistant (MDR) H. pylori strains and is upregulated by SpoT. Through further research, we determined that gluP is involved in H. pylori biofilm formation and multidrug resistance. Furthermore, the average expression level of gluP in the clinical MDR strains (C-MDR) was considerably higher than that in the clinical drug-sensitive strains (C-DSS). Taken together, our results revealed a novel molecular mechanism of H. pylori resistance to multidrug exposure.
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25
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Marcus EA, Sachs G, Scott DR. Acid-regulated gene expression of Helicobacter pylori: Insight into acid protection and gastric colonization. Helicobacter 2018; 23:e12490. [PMID: 29696729 PMCID: PMC5980792 DOI: 10.1111/hel.12490] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND The pathogen Helicobacter pylori encounters many stressors as it transits to and infects the gastric epithelium. Gastric acidity is the predominate stressor encountered by the bacterium during initial infection and establishment of persistent infection. H. pylori initiates a rapid response to acid to maintain intracellular pH and proton motive force appropriate for a neutralophile. However, acid sensing by H. pylori may also serve as a transcriptional trigger to increase the levels of other pathogenic factors needed to subvert host defenses such as acid acclimation, antioxidants, flagellar synthesis and assembly, and CagA secretion. MATERIALS AND METHODS Helicobacter pylori were acid challenged at pH 3.0, 4.5, 6.0 vs nonacidic pH for 4 hours in the presence of urea, followed by RNA-seq analysis and qPCR. Cytoplasmic pH was monitored under the same conditions. RESULTS About 250 genes were induced, and an equal number were repressed at acidic pHs. Genes encoding for antioxidant proteins, flagellar structural proteins, particularly class 2 genes, T4SS/Cag-PAI, Fo F1 -ATPase, and proteins involved in acid acclimation were highly expressed at acidic pH. Cytoplasmic pH decreased from 7.8 at pHout of 8.0 to 6.0 at pHout of 3.0. CONCLUSIONS These results suggest that increasing extracellular or intracellular acidity or both are detected by the bacterium and serve as a signal to initiate increased production of protective and pathogenic factors needed to counter host defenses for persistent infection. These changes are dependent on degree of acidity and time of acid exposure, triggering a coordinated response to the environment required for colonization.
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Affiliation(s)
- Elizabeth A. Marcus
- Department of Pediatrics, David Geffen School of Medicine at UCLA,VA GLAHS, Los Angeles, CA
| | - George Sachs
- Department Medicine, David Geffen School of Medicine at UCLA,Department Physiology, David Geffen School of Medicine at UCLA,VA GLAHS, Los Angeles, CA
| | - David R. Scott
- Department Physiology, David Geffen School of Medicine at UCLA,VA GLAHS, Los Angeles, CA,Corresponding author: David R. Scott, Department of Physiology, DGSOM at UCLA, VA GLAHS, Bldg 113, Rm 324, 11301 Wilshire Blvd, Los Angeles, CA 90073, , phone: 310-478-3711 x42046; Fax: 310-312-9478
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26
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Chen J, Ye L, Jin L, Xu X, Xu P, Wang X, Li H. Application of next-generation sequencing to characterize novel mutations in clarithromycin-susceptible Helicobacter pylori strains with A2143G of 23S rRNA gene. Ann Clin Microbiol Antimicrob 2018; 17:10. [PMID: 29562911 PMCID: PMC5863438 DOI: 10.1186/s12941-018-0259-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 03/08/2018] [Indexed: 12/22/2022] Open
Abstract
Background Clarithromycin (CLR) resistance has become a predominant factor for treatment failure of Helicobacter pylori eradication. Although the molecular mechanism of CLR resistance has been clearly understood in H. pylori, it is lack of evidence of other genes involved in drug resistance. Furthermore, the molecular mechanism of phenotype susceptible to CLR while genotype of 23S rRNA is mutant with A2143G is unclear. Here, we characterized the mutations of CLR-resistant and -susceptible H. pylori strains to explore bacterial resistance. Methods In the present study, the whole genomes of twelve clinical isolated H. pylori strains were sequenced, including two CLR-susceptible strains with mutation of A2143G. Single nucleotide variants (SNVs) were extracted and analyzed from multidrug efflux transporter genes. Results We did not find mutations associated with known CLR-resistant sites except for controversial T2182C outside of A2143G in the 23S rRNA gene. Although total SNVs of multidrug efflux transporter gene and the SNVs of HP0605 were significant differences (P ≤ 0.05) between phenotype resistant and susceptible strains. There is no significant difference in SNVs of RND or MFS (HP1181) family. However, the number of mutations in the RND family was significantly higher in the mutant strain (A2143G) than in the wild type. In addition, three special variations from two membrane proteins of mtrC and hefD were identified in both CLR-susceptible strains with A2143G. Conclusions Next-generation sequencing is a practical strategy for analyzing genomic variation associated with antibiotic resistance in H. pylori. The variations of membrane proteins of the RND family may be able to participate in the regulation of clinical isolated H. pylori susceptibility profiles.
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Affiliation(s)
- Jiaoe Chen
- Department of Gastroenterology, Sanmen People's Hospital, No. 117, Renmin Road, Sanmen, 317100, Zhejiang, People's Republic of China
| | - Liping Ye
- Department of Gastroenterology, Zhejiang Taizhou Hospital, Taizhou, 31700, People's Republic of China
| | - Liangmin Jin
- Department of Gastroenterology, Sanmen People's Hospital, No. 117, Renmin Road, Sanmen, 317100, Zhejiang, People's Republic of China
| | - Xuehua Xu
- Department of Gastroenterology, Sanmen People's Hospital, No. 117, Renmin Road, Sanmen, 317100, Zhejiang, People's Republic of China
| | - Peisong Xu
- Department of Research Service, Zhiyuan Inspection Medical Institute, Hangzhou, Zhejiang, 310006, People's Republic of China
| | - Xianjun Wang
- Clinical Laboratory, Hangzhou First People's Hospital, Hangzhou, 310006, Zhejiang, People's Republic of China
| | - Hongzhang Li
- Department of Gastroenterology, Sanmen People's Hospital, No. 117, Renmin Road, Sanmen, 317100, Zhejiang, People's Republic of China.
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27
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Lee SM, Kim N, Kwon YH, Nam RH, Kim JM, Park JY, Lee YS, Lee DH. rdxA, frxA, and efflux pump in metronidazole-resistant Helicobacter pylori: Their relation to clinical outcomes. J Gastroenterol Hepatol 2018; 33:681-688. [PMID: 28748532 DOI: 10.1111/jgh.13906] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2017] [Revised: 07/19/2017] [Accepted: 07/21/2017] [Indexed: 01/06/2023]
Abstract
BACKGROUND AND AIM rdxA and frxA mutations and enhancement of efflux pump have been suggested as the cause of metronidazole resistance in Helicobacter pylori. This study was performed to investigate the resistance mechanisms related to clinical eradication outcome, and to examine direct involvement of hefA in metronidazole-resistant isolates with intact rdxA and frxA. METHODS A total of 53 H. pylori-positive patients who were treated with metronidazole-containing sequential or quadruple therapy from 2011 to 2015 were enrolled. The metronidazole susceptibility of H. pylori isolates was examined by agar dilution test. Mutations in rdxA and frxA, were analyzed with DNA sequencing, and impact of hefA on metronidazole resistance was examined with quantitative real-time reverse transcription polymerase chain reaction, knockout and genetic complementation test for hefA. RESULTS Seven mutation types of rdxA and/or frxA were found in H. pylori isolated from non-eradicated subjects. rdxA mutation was associated with eradication failure (P = 0.002), and nonsense mutation in rdxA reduced eradication efficacy (P = 0.009). hefA expression was significantly higher in resistant isolates (P < 0.001), especially in rdxA(-)frxA(-) as compared to rdxA(+)frxA(+) (P = 0.027). Resistant isolates with no mutation in rdxA and frxA became susceptible after hefA knockout. Genetic complementation for hefA recovered metronidazole resistance in all of three hefA knockout mutants. CONCLUSIONS These results suggest that rdxA mutations play a critical role in metronidazole resistance as well as the outcomes of eradication therapy. In addition, hefA seems to be directly involved in metronidazole resistance, which explains the resistance in clinical isolates with intact rdxA and frxA.
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Affiliation(s)
- Sun Min Lee
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do, Korea
| | - Nayoung Kim
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do, Korea.,Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - Yong Hwan Kwon
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do, Korea
| | - Ryoung Hee Nam
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do, Korea
| | - Jung Mogg Kim
- Department of Microbiology, Hanyang University School of Medicine, Seoul, Korea
| | - Jong Youn Park
- School of Pharmacy, MCPHS University, Boston, Massachusetts, USA
| | - Yeon Suk Lee
- University of New South Wales, Sydney, New South Wales, Australia
| | - Dong Ho Lee
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do, Korea
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28
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Abadi ATB. Resistance to clarithromycin and gastroenterologist’s persistence roles in nomination for Helicobacter pylori as high priority pathogen by World Health Organization. World J Gastroenterol 2017; 23:6379-6384. [PMID: 29085187 PMCID: PMC5643263 DOI: 10.3748/wjg.v23.i35.6379] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 08/06/2017] [Accepted: 08/25/2017] [Indexed: 02/07/2023] Open
Abstract
Due to the increasing prevalence of clarithromycin resistance, future of management of Helicobacter pylori (H. pylori) infections need to be recognized. To now, clarithromycin was the best effective, well-tolerated and safe antibiotic used in treatment of the bacterium, but, increasing trend of resistance reduced efficacy of recommended regimens. Indeed, gastroenterologists are mostly unable to start appropriate therapy-according to the sensitivity profile-due to the certain difficulties in routine H. pylori culture procedure and being time consuming method. This announcement by World Health Organization (WHO) was an onset to reconsider current challenging dilemma about H. pylori clarithromycin resistant isolates. Therefore, investigating of various factors affecting this nomination by WHO is highly welcomed. In fact, WHO enumerated more than 16 pathogens which seriously threats human life and public health, thus better management or effective guidelines are necessary. Here for the first time, we nominated this phenomenon as ‘‘gastroenterologist’s persistence’’ which should be equally investigated as antibiotic resistance. The ability of gastroenterologists to win the game against H. pylori infections is highly influenced by their collaboration with diagnostic laboratories to apply susceptibility patterns before any prescription. In conclusion, closer collaboration between two important partners (gastroenterologists and microbiologists) in management of H. pylori infection may hopefully trigger an era to remedy current crisis in clarithromycin resistance, a later gastric cancer can be practically preventable.
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Affiliation(s)
- Amin Talebi Bezmin Abadi
- Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran 14115, Iran
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29
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The Bifunctional Enzyme SpoT Is Involved in the Clarithromycin Tolerance of Helicobacter pylori by Upregulating the Transporters HP0939, HP1017, HP0497, and HP0471. Antimicrob Agents Chemother 2017; 61:AAC.02011-16. [PMID: 28242673 PMCID: PMC5404559 DOI: 10.1128/aac.02011-16] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 02/21/2017] [Indexed: 01/30/2023] Open
Abstract
Clarithromycin (CLA) is a commonly recommended drug for Helicobacter pylori eradication. However, the prevalence of CLA-resistant H. pylori is increasing. Although point mutations in the 23S rRNA are key factors for CLA resistance, other factors, including efflux pumps and regulation genes, are also involved in the resistance of H. pylori to CLA. Guanosine 3′-diphosphate 5′-triphosphate and guanosine 3′,5′-bispyrophosphate [(p)ppGpp)], which are synthesized by the bifunctional enzyme SpoT in H. pylori, play an important role for some bacteria to adapt to antibiotic pressure. Nevertheless, no related research involving H. pylori has been reported. In addition, transporters have been found to be related to bacterial drug resistance. Therefore, this study investigated the function of SpoT in H. pylori resistance to CLA by examining the shifts in the expression of transporters and explored the role of transporters in the CLA resistance of H. pylori. A ΔspoT strain was constructed in this study, and it was shown that SpoT is involved in H. pylori tolerance of CLA by upregulating the transporters HP0939, HP1017, HP0497, and HP0471. This was assessed using a series of molecular and biochemical experiments and a cDNA microarray. Additionally, the knockout of genes hp0939, hp0471, and hp0497 in the resistant strains caused a reduction or loss (the latter in the Δhp0497 strain) of resistance to CLA. Furthermore, the average expression levels of these four transporters in clinical CLA-resistant strains were considerably higher than those in clinical CLA-sensitive strains. Taken together, our results revealed a novel molecular mechanism of H. pylori adaption to CLA stress.
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30
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Wang D, Gong YH, Yuan Y. Bacterial factors associated with Helicobacter pylori antibiotic resistance. Shijie Huaren Xiaohua Zazhi 2016; 24:4102-4109. [DOI: 10.11569/wcjd.v24.i29.4102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Helicobacter pylori (H. pylori) infection is the most widespread chronic bacterial infection and is closely associated with many diseases. In recent years, however, H. pylori is becoming increasingly difficult to eradicate due to the growing antibiotic resistance. Among the reasons for the failed eradication, some factors of H. pylori itself play a main role. H. pylori can resist antibiotics by producing inactivating enzymes, changing the drug targets, preventing oxidation-reduction electron transfer, decreasing membrane permeability and activating efflux pump, changing bacterial metabolic state and so on. Elucidating the mechanism of antibiotic resistance will be helpful in developing new targeted drugs to effectively eradicate H. pylori. Here, we review the bacteria factors associated with H. pylori antibiotic resistance.
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Hu Y, Zhang M, Lu B, Dai J. Helicobacter pylori and Antibiotic Resistance, A Continuing and Intractable Problem. Helicobacter 2016; 21:349-63. [PMID: 26822340 DOI: 10.1111/hel.12299] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Helicobacter pylori, a human pathogen with a high global prevalence, is the causative pathogen for multiple gastrointestinal diseases, especially chronic gastritis, peptic ulcers, gastric mucosa-associated lymphoid tissue lymphoma, and gastric malignancies. Antibiotic therapies remain the mainstay for H. pylori eradication; however, this strategy is hampered by the emergence and spread of H. pylori antibiotic resistance. Exploring the mechanistic basis of this resistance is becoming one of the major research questions in contemporary biomedical research, as such knowledge could be exploited to devise novel rational avenues for counteracting the existing resistance and devising strategies to avoid the development of a novel anti-H. pylori medication. Encouragingly, important progress in this field has been made recently. Here, we attempt to review the current state and progress with respect to the molecular mechanism of antibiotic resistance for H. pylori. A picture is emerging in which mutations of various genes in H. pylori, resulting in decreased membrane permeability, altered oxidation-reduction potential, and a more efficient efflux pump system. The increased knowledge on these mechanisms produces hope that antibiotic resistance in H. pylori can ultimately be countered.
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Affiliation(s)
- Yue Hu
- Department of Gastroenterology, First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, China
| | - Meng Zhang
- Department of Gastroenterology, First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, China
| | - Bin Lu
- Department of Gastroenterology, First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, China.
| | - Jinfeng Dai
- Department of Gastroenterology, First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, China
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Alarcón-Millán J, Fernández-Tilapa G, Cortés-Malagón EM, Castañón-Sánchez CA, De Sampedro-Reyes J, Cruz-Del Carmen I, Betancourt-Linares R, Román-Román A. Clarithromycin resistance and prevalence of Helicobacter pylori virulent genotypes in patients from Southern México with chronic gastritis. INFECTION GENETICS AND EVOLUTION 2016; 44:190-198. [PMID: 27355861 DOI: 10.1016/j.meegid.2016.06.044] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 06/21/2016] [Accepted: 06/23/2016] [Indexed: 02/07/2023]
Abstract
In developing countries, clarithromycin resistance and frequency of re-infection are factors that contribute to high prevalence of Helicobacter pylori infection. The aim of this research was determine the prevalence of clarithromycin resistance and its relation with A2142G, A2142C and A2143G mutations in the domain V of the 23S rRNA gene of H. pylori isolates in patients from Southern Mexico with chronic gastritis. Another purpose of this work was to study the prevalence of virulent genotypes and distribution of resistant strains according to the vacA/cagA/babA2 H. pylori genotypes. One hundred forty-four patients with chronic gastritis were studied. Forty-five H. pylori strains were isolated and clarithromycin susceptibility was determined by the disk-diffusion method. The 82.2% of the strains had the combination of alleles vacA s1 m1 and the cagA gene was detected in 77.8% and 40% of the strains were babA2 positive. The vacA s1 m1 genotype was detected more frequently in cagA(+) strains, vacA s1m1/cagA(+)/babA2(-) genotype was more frequent than vacA s1m1/cagA(+)/babA2(+), 37.8% and 33.3%, respectively. Eight strains were clarithromycin resistant, in three of these, point mutations were identified, but only in one strain the A2143G mutation associated with clarithromycin resistance was found. Other point mutations (A1821G, G1826A, T1830C, A2089G, T1600C, C1601T, C1602T, T1610C, A1611C and T1633G) that have not been associated with clarithromycin resistance were identified. The highest proportion of resistant strains was vacA s1m1/cagA(+) (62.5%). In patients from southern Mexico with chronic gastritis, the prevalence of clarithromycin resistance is within internationally accepted range (17.8%) and allows continued use of triple therapy for H. pylori eradication. However, it is necessary to monitor the evolution of clarithromycin resistance in this area. The largest proportion of resistant H. pylori strains is not harboring the A2142G, A2142C and A2143G mutations in the 23S rRNA gene (87.5%). The vacA s1m1/cagA(+) genotype was the most prevalent and among clarithromycin-resistant strains, this was the predominant.
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Affiliation(s)
- Judit Alarcón-Millán
- Laboratorio de Investigación en Bacteriología, Unidad Académica de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Chilpancingo, Guerrero, México.
| | - Gloria Fernández-Tilapa
- Laboratorio de Investigación Clínica, Unidad Académica de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Chilpancingo, Guerrero, México.
| | - Enoc Mariano Cortés-Malagón
- Laboratorio de Biología Molecular del Cáncer, Unidad de Investigación, Hospital Juárez de México, Ciudad de México, México.
| | | | | | - Iván Cruz-Del Carmen
- Hospital General "Dr. Raymundo Abarca Alarcón", Chilpancingo, Guerrero, México; Unidad Especializada de Gastroenterología Endoscopia, Chilpancingo, Guerrero, México.
| | | | - Adolfo Román-Román
- Laboratorio de Investigación en Bacteriología, Unidad Académica de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Chilpancingo, Guerrero, México.
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Falsafi T, Ehsani A, Attaran B, Niknam V. Association of hp1181 and hp1184 Genes With the Active Efflux Phenotype in Multidrug-Resistant Isolates of Helicobacter pylori. Jundishapur J Microbiol 2016; 9:e30726. [PMID: 27303615 PMCID: PMC4902859 DOI: 10.5812/jjm.30726] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Revised: 10/29/2015] [Accepted: 12/23/2015] [Indexed: 02/07/2023] Open
Abstract
Background During the last decades the rate of multidrug resistance among clinical Helicobacter pylori isolates has increased. Active pumping out of the drugs may be an important mechanism for multidrug resistance in H. pylori strains. Objectives The aim of this study was to evaluate the association of two H. pylori efflux-genes, hp1181 and hp1184 with the active-efflux phenotype in MDR clinical-strains of H. pylori. Materials and Methods Minimal inhibitory concentration (MIC) and drug accumulation for β-lactames, Tetracycline (TET), Erythromycin (ERY), Metronidazole (MTZ), Ciprofloxacin (CIP) and Ethidium Bromide (EtBr) was performed in the presence and absence of carbonyl cyanide M-Chlorophenyl Hydrazone (CCCP). Presence of hp1181 and hp1184 genes was detected by the polymerase chain reaction (PCR). RT-PCR was performed to compare expression of efflux genes by MDR strains, demonstrating active efflux with the strains without active efflux. Results Two- to four-fold decrease in minimum inhibitory concentration (MIC) and two-fold increase in accumulation were observed for EtBr in the presence of CCCP for 67% (8) of 12 MDR strains. With CCCP, two- to four-fold decrease in MIC and 1.4- to 1.8-fold increase in the accumulation of β-lactames, TET, CIP and MTZ were obtained for 42% (5) of the MDR strains. Six, five and three of the 12 MDR strains amplified hp1184, hp1181, and both of them, respectively. The RT-PCR product for expression of hp1181 by MDR strains was approximately 100 bp shorter than that of the 26695 susceptible standard strain. Conclusions Expression of the genes hp1184 and hp1181 are associated with the specific active efflux of EtBr and non-related antibiotics, respectively. For displaying these phenotypes, a post-transcriptional regulation step may be required.
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Affiliation(s)
- Tahereh Falsafi
- Depatment of Microbiology, Faculty of Biological Sciences, Alzahra University, Tehran, IR Iran
- Corresponding author: Tahereh Falsafi, Depatment of Microbiology, Faculty of Biological Sciences, Alzahra University, Tehran, IR Iran. Tel/Fax: +98-2188058912, E-mail:
| | - Azadeh Ehsani
- Depatment of Microbiology, Faculty of Biological Sciences, Alzahra University, Tehran, IR Iran
| | - Bahareh Attaran
- Depatment of Microbiology, Faculty of Biological Sciences, Alzahra University, Tehran, IR Iran
| | - Vahid Niknam
- School of Biology, Tehran University, Tehran, IR Iran
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Multidrug Efflux Systems in Microaerobic and Anaerobic Bacteria. Antibiotics (Basel) 2015; 4:379-96. [PMID: 27025630 PMCID: PMC4790292 DOI: 10.3390/antibiotics4030379] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 08/11/2015] [Accepted: 08/13/2015] [Indexed: 12/13/2022] Open
Abstract
Active drug efflux constitutes an important mechanism of antibiotic and multidrug resistance in bacteria. Understanding the distribution, expression, and physiological functions of multidrug efflux pumps, especially under physiologically and clinically relevant conditions of the pathogens, is the key to combat drug resistance. In animal hosts, most wounded, infected and inflamed tissues display low oxygen tensions. In this article, we summarize research development on multidrug efflux pumps in the medicinally relevant microaerobic and anaerobic pathogens and their implications in the effort to combat drug-resistant infections.
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Qureshi NN, Gallaher B, Schiller NL. Evolution of amoxicillin resistance of Helicobacter pylori in vitro: characterization of resistance mechanisms. Microb Drug Resist 2015; 20:509-16. [PMID: 24901497 DOI: 10.1089/mdr.2014.0019] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Helicobacter pylori is the major cause of peptic ulcers and gastric cancer in humans. Treatment involves a two or three drug cocktail, typically including amoxicillin. Increasing levels of resistance to amoxicillin contribute to treatment failures, and higher levels of resistance are believed to be due to multiple genetic mutations. In this study, we examined the progression of spontaneous genetic mutations that contribute to amoxicillin resistance in H. pylori when exposed to increasing concentrations of amoxicillin in vitro. During the selection process, we isolated five strains each of which had progressively higher levels of resistance. Using a whole genome sequencing approach, we identified mutations in a number of genes, notably pbp1, pbp2, hefC, hopC, and hofH, and by sequencing these genes in each isolate we were able to map the order and gradual accumulation of mutations in these isolates. These five isolates, each expressing multiple mutated genes and four transformed strains expressing individually mutated pbp1, hefC, or hofH, were characterized using minimum inhibitory concentrations, amoxicillin uptake, and efflux studies. Our results indicate that mutations in pbp1, hefC, hopC, hofH, and possibly pbp2 contribute to H. pylori high-level amoxicillin resistance. The data also provide evidence for the complexity of the evolution of amoxicillin resistance in H. pylori and indicate that certain families of genes might be more susceptible to amoxicillin resistance mutations than others.
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Affiliation(s)
- Nadia N Qureshi
- Division of Biomedical Sciences, School of Medicine, University of California , Riverside, Riverside, California
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Li XZ, Plésiat P, Nikaido H. The challenge of efflux-mediated antibiotic resistance in Gram-negative bacteria. Clin Microbiol Rev 2015; 28:337-418. [PMID: 25788514 PMCID: PMC4402952 DOI: 10.1128/cmr.00117-14] [Citation(s) in RCA: 924] [Impact Index Per Article: 102.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The global emergence of multidrug-resistant Gram-negative bacteria is a growing threat to antibiotic therapy. The chromosomally encoded drug efflux mechanisms that are ubiquitous in these bacteria greatly contribute to antibiotic resistance and present a major challenge for antibiotic development. Multidrug pumps, particularly those represented by the clinically relevant AcrAB-TolC and Mex pumps of the resistance-nodulation-division (RND) superfamily, not only mediate intrinsic and acquired multidrug resistance (MDR) but also are involved in other functions, including the bacterial stress response and pathogenicity. Additionally, efflux pumps interact synergistically with other resistance mechanisms (e.g., with the outer membrane permeability barrier) to increase resistance levels. Since the discovery of RND pumps in the early 1990s, remarkable scientific and technological advances have allowed for an in-depth understanding of the structural and biochemical basis, substrate profiles, molecular regulation, and inhibition of MDR pumps. However, the development of clinically useful efflux pump inhibitors and/or new antibiotics that can bypass pump effects continues to be a challenge. Plasmid-borne efflux pump genes (including those for RND pumps) have increasingly been identified. This article highlights the recent progress obtained for organisms of clinical significance, together with methodological considerations for the characterization of MDR pumps.
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Affiliation(s)
- Xian-Zhi Li
- Human Safety Division, Veterinary Drugs Directorate, Health Products and Food Branch, Health Canada, Ottawa, Ontario, Canada
| | - Patrick Plésiat
- Laboratoire de Bactériologie, Faculté de Médecine-Pharmacie, Centre Hospitalier Régional Universitaire, Université de Franche-Comté, Besançon, France
| | - Hiroshi Nikaido
- Department of Molecular and Cell Biology, University of California, Berkeley, California, USA
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Functional analysis of Vibrio vulnificus RND efflux pumps homologous to Vibrio cholerae VexAB and VexCD, and to Escherichia coli AcrAB. J Microbiol 2015; 53:256-61. [PMID: 25740377 DOI: 10.1007/s12275-015-5037-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 01/28/2015] [Accepted: 01/29/2015] [Indexed: 01/05/2023]
Abstract
Resistance-nodulation-division (RND) efflux pumps are associated with multidrug resistance in many gram-negative pathogens. The genome of Vibrio vulnificus encodes 11 putative RND pumps homologous to those of Vibrio cholerae and Escherichia coli. In this study, we analyzed three putative RND efflux pumps, showing homology to V. cholerae VexAB and VexCD and to E. coli AcrAB, for their functional roles in multidrug resistance of V. vulnificus. Deletion of the vexAB homolog resulted in increased susceptibility of V. vulnificus to bile acid, acriflavine, ethidium bromide, and erythromycin, whereas deletion of acrAB homologs rendered V. vulnificus more susceptible to acriflavine only. Deletion of vexCD had no effect on susceptibility of V. vulnificus to these chemicals. Upon exposure to these antibacterial chemicals, expression of tolCV1 and tolCV2, which are putative outer membrane factors of RND efflux pumps, was induced, whereas expression levels of vexAB, vexCD, and acrAB homologs were not significantly changed. Our results show that the V. vulnificus homologs of VexAB largely contributed to in vitro antimicrobial resistance with a broad substrate specificity that was partially redundant with the AcrAB pump homologs.
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Nishizawa T, Suzuki H. Mechanisms of Helicobacter pylori antibiotic resistance and molecular testing. Front Mol Biosci 2014; 1:19. [PMID: 25988160 PMCID: PMC4428472 DOI: 10.3389/fmolb.2014.00019] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2014] [Accepted: 10/04/2014] [Indexed: 12/14/2022] Open
Abstract
Antibiotic resistance in Helicobacter pylori (H.pylori) is the main factor affecting the efficacy of current treatment methods against infection caused by this organism. The traditional culture methods for testing bacterial susceptibility to antibiotics are expensive and require 10–14 days. Since resistance to clarithromycin, fluoroquinolone, and tetracycline seems to be exclusively caused by specific mutations in a small region of the responsible gene, molecular methods offer an attractive alternative to the above-mentioned techniques. The technique of polymerase chain reaction (PCR) is an accurate and rapid method for the detection of mutations that confer antibiotic resistance. This review highlights the mechanisms of antibiotic resistance in H. pylori and the molecular methods for antibiotic susceptibility testing.
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Affiliation(s)
- Toshihiro Nishizawa
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine Tokyo, Japan ; Division of Research and Development for Minimally Invasive Treatment, Cancer Center, Keio University School of Medicine Tokyo, Japan
| | - Hidekazu Suzuki
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine Tokyo, Japan
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Whole-genome sequencing of clarithromycin resistant Helicobacter pylori characterizes unidentified variants of multidrug resistant efflux pump genes. Gut Pathog 2014; 6:27. [PMID: 24995043 PMCID: PMC4079918 DOI: 10.1186/1757-4749-6-27] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 06/18/2014] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Clarithromycin (CLR) is the key drug in eradication therapy of Helicobacter pylori (H. pylori) infection, and widespread use of CLR has led to an increase in primary CLR-resistant H. pylori. The known mechanism of CLR resistance has been established in A2146G and A2147G mutations in the 23S rRNA gene, but evidence of the involvement of other genetic mechanisms is lacking. Using the MiSeq platform, whole-genome sequencing of the 19 clinical strains and the reference strain ATCC26695 was performed to identify single nucleotide variants (SNVs) of multi-drug resistant efflux pump genes in the CLR-resistant phenotype. RESULTS Based on sequencing data of ATCC26695, over one million sequencing reads with over 50-fold coverage were sufficient to detect SNVs, but not indels in the bacterial genome. Sequencing reads of the clinical isolates ranged from 1.82 to 10.8 million, and average coverage ranged from 90.9- to 686.3-fold, which were acceptable criteria for detecting SNVs. Utilizing the conventional approach of allele-specific PCR, point mutations in the 23S rRNA gene were detected in 12 clinical resistant isolates, but not in 7 clinical susceptible isolates. All sequencing reads of CLR-resistant strains had a G mutation in an identical position of the 23S rRNA gene. In addition, genetic variants of four gene clusters (hp0605-hp0607, hp0971-hp0969, hp1327-hp1329, and hp1489-hp1487) of TolC homologues, which have been implicated in multi-drug resistance, were examined. Specific SNVs were dominantly found in resistant strains. CONCLUSIONS Gene clusters of TolC homologues are involved in CLR susceptibility profiles in individual H. pylori strains. Whole-genome sequencing has yielded novel understanding of genotype-phenotype relationships.
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Handley KM, Bartels D, O'Loughlin EJ, Williams KH, Trimble WL, Skinner K, Gilbert JA, Desai N, Glass EM, Paczian T, Wilke A, Antonopoulos D, Kemner KM, Meyer F. The complete genome sequence for putative H2- and S-oxidizerCandidatusSulfuricurvum sp., assembledde novofrom an aquifer-derived metagenome. Environ Microbiol 2014; 16:3443-62. [DOI: 10.1111/1462-2920.12453] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Accepted: 03/04/2014] [Indexed: 11/26/2022]
Affiliation(s)
- Kim M. Handley
- Department of Ecology and Evolution; University of Chicago; Chicago IL 60637 USA
- Institute for Genomics and Systems Biology; Argonne National Laboratory; Lemont IL 60439 USA
| | - Daniela Bartels
- Institute for Genomics and Systems Biology; Argonne National Laboratory; Lemont IL 60439 USA
- Computation Institute; University of Chicago; Chicago IL 60637 USA
| | | | - Kenneth H. Williams
- Earth Science Division; Lawrence Berkeley National Laboratory; Berkeley CA USA
| | - William L. Trimble
- Mathematics and Computer Science Division; Argonne National Laboratory; Lemont IL 60439 USA
| | - Kelly Skinner
- Biosciences Division; Argonne National Laboratory; Lemont IL 60439 USA
| | - Jack A. Gilbert
- Department of Ecology and Evolution; University of Chicago; Chicago IL 60637 USA
- Institute for Genomics and Systems Biology; Argonne National Laboratory; Lemont IL 60439 USA
- Biosciences Division; Argonne National Laboratory; Lemont IL 60439 USA
| | - Narayan Desai
- Mathematics and Computer Science Division; Argonne National Laboratory; Lemont IL 60439 USA
| | - Elizabeth M. Glass
- Computation Institute; University of Chicago; Chicago IL 60637 USA
- Mathematics and Computer Science Division; Argonne National Laboratory; Lemont IL 60439 USA
| | - Tobias Paczian
- Computation Institute; University of Chicago; Chicago IL 60637 USA
- Mathematics and Computer Science Division; Argonne National Laboratory; Lemont IL 60439 USA
| | - Andreas Wilke
- Computation Institute; University of Chicago; Chicago IL 60637 USA
- Mathematics and Computer Science Division; Argonne National Laboratory; Lemont IL 60439 USA
| | - Dionysios Antonopoulos
- Institute for Genomics and Systems Biology; Argonne National Laboratory; Lemont IL 60439 USA
- Biosciences Division; Argonne National Laboratory; Lemont IL 60439 USA
| | - Kenneth M. Kemner
- Biosciences Division; Argonne National Laboratory; Lemont IL 60439 USA
| | - Folker Meyer
- Institute for Genomics and Systems Biology; Argonne National Laboratory; Lemont IL 60439 USA
- Computation Institute; University of Chicago; Chicago IL 60637 USA
- Mathematics and Computer Science Division; Argonne National Laboratory; Lemont IL 60439 USA
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Abstract
The wide use and abuse of antibiotics have led to serious drug resistance of Helicobacter pylori (H. pylori), and strains simultaneously resistant to metronidazole, clarithromycin and amoxicillin have appeared. As a result, the rate of H. pylori eradication declines clinically. The presence of bacterial efflux pumps is an important mechanism responsible for bacterial resistance to most antibiotics, especially multiple drug resistance (MDR). In recent years, much attention has been paid to the research of efflux pumps and their inhibitors to solve the problem of drug resistance of H. pylori. In this paper we will introduce main efflux pumps and efflux pump inhibitors in H. pylori.
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Lee JW, Kim N, Kim JM, Nam RH, Chang H, Kim JY, Shin CM, Park YS, Lee DH, Jung HC. Prevalence of primary and secondary antimicrobial resistance of Helicobacter pylori in Korea from 2003 through 2012. Helicobacter 2013; 18:206-14. [PMID: 23241101 DOI: 10.1111/hel.12031] [Citation(s) in RCA: 163] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Antimicrobial resistance of Helicobacter pylori (H. pylori) affects the efficacy of eradication therapy. The aim of this study was to estimate the prevalence of primary and secondary resistance of H. pylori isolates to antibiotics and to characterize the risk factors associated with antimicrobial resistance in Korea. MATERIALS AND METHODS This study was performed during the period of 2003-2012. Primary resistance was evaluated from 347 patients without any history of eradication, and secondary resistance was evaluated in 86 patients from whom H. pylori was cultured after failure of eradication. Minimal inhibitory concentration test was performed for amoxicillin, clarithromycin, metronidazole, tetracycline, azithromycin, levofloxacin, and moxifloxacin using agar dilution method. Primary and secondary resistance rates of H. pylori to 7 antibiotics were evaluated and risk factors for the antibiotic resistance were analyzed. RESULTS Increase in the primary resistance rate was found in amoxicillin (6.3-14.9%, p = .051), clarithromycin (17.2-23.7%, p = .323), and both of levofloxacin and moxifloxacin (4.7-28.1%, p = .002) during the study period. Secondary resistance rate significantly increased in metronidazole, levofloxacin, and moxifloxacin. Increase of resistance occurred after initial failure of eradication therapy in case of clarithromycin (p < .001), azithromycin (p < .001), levofloxacin (p = .011), and moxifloxacin (p = .020). Multivariable analyses showed that clarithromycin, azithromycin, levofloxacin, and moxifloxacin resistance was associated with previous eradication treatment history. CONCLUSIONS The increased primary and secondary antibiotic resistance of H. pylori in Korea is ongoing, and it will become a significant limitation for effective eradication of H. pylori in the future.
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Affiliation(s)
- Jung Won Lee
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do, Korea
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Huang YW, Hu RM, Yang TC. Role of the pcm-tolCsm operon in the multidrug resistance of Stenotrophomonas maltophilia. J Antimicrob Chemother 2013; 68:1987-93. [DOI: 10.1093/jac/dkt148] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
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The α-barrel tip region of Escherichia coli TolC homologs of Vibrio vulnificus interacts with the MacA protein to form the functional macrolide-specific efflux pump MacAB-TolC. J Microbiol 2013; 51:154-9. [PMID: 23625214 DOI: 10.1007/s12275-013-2699-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 12/25/2012] [Indexed: 10/26/2022]
Abstract
TolC and its homologous family of proteins are outer membrane factors that are essential for exporting small molecules and toxins across the outer membrane in Gram-negative bacteria. Two open reading frames in the Vibrio vulnificus genome that encode proteins homologous to Escherichia coli TolC, designated TolCV1 and TolCV2, have 51.3% and 29.6% amino acid identity to TolC, respectively. In this study, we show that TolCV1 and TolCV2 functionally and physically interacted with the membrane fusion protein, MacA, a component of the macrolide-specific MacAB-TolC pump of E. coli. We further show that the conserved residues located at the aperture tip region of the α-hairpin of TolCV1 and TolCV2 played an essential role in the formation of the functional MacAB-TolC pump using site-directed mutational analyses. Our findings suggest that these outer membrane factors have conserved tip-to-tip interaction with the MacA membrane fusion protein for action of the drug efflux pump in Gram-negative bacteria.
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Alvarez-Ortega C, Olivares J, Martínez JL. RND multidrug efflux pumps: what are they good for? Front Microbiol 2013; 4:7. [PMID: 23386844 PMCID: PMC3564043 DOI: 10.3389/fmicb.2013.00007] [Citation(s) in RCA: 135] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Accepted: 01/07/2013] [Indexed: 01/27/2023] Open
Abstract
Multidrug efflux pumps are chromosomally encoded genetic elements capable of mediating resistance to toxic compounds in several life forms. In bacteria, these elements are involved in intrinsic and acquired resistance to antibiotics. Unlike other well-known horizontally acquired antibiotic resistance determinants, genes encoding for multidrug efflux pumps belong to the core of bacterial genomes and thus have evolved over millions of years. The selective pressure stemming from the use of antibiotics to treat bacterial infections is relatively recent in evolutionary terms. Therefore, it is unlikely that these elements have evolved in response to antibiotics. In the last years, several studies have identified numerous functions for efflux pumps that go beyond antibiotic extrusion. In this review we present some examples of these functions that range from bacterial interactions with plant or animal hosts, to the detoxification of metabolic intermediates or the maintenance of cellular homeostasis.
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Affiliation(s)
- Carolina Alvarez-Ortega
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas Madrid, Spain
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Brown JC, Jiang X. Activities of muscadine grape skin and polyphenolic constituents against Helicobacter pylori. J Appl Microbiol 2013; 114:982-91. [PMID: 23294280 DOI: 10.1111/jam.12129] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Revised: 11/13/2012] [Accepted: 12/20/2012] [Indexed: 12/30/2022]
Abstract
AIMS To identify active phenolic constituents in muscadine grape skin (MGS) extracts and determine interactions among compounds while further exploring their anti-Helicobacter pylori potential in vitro. METHODS AND RESULTS The inhibitory effects of quercetin and resveratrol, active polyphenols identified in MGS extracts, against H. pylori were investigated. Quercetin and resveratrol significantly (P < 0.05) reduced H. pylori counts regardless of pH with minimal bactericidal concentrations of 256 and 128 μg ml(-1), respectively. MGS extracts displayed the highest efficacy, suggesting additional unidentified compounds not determined in this study. Time-course viability experiments showed a dose-dependent anti-H. pylori response to quercetin and resveratrol. Interestingly, neither quercetin nor resveratrol affected H. pylori outer membrane (OM) integrity as determined by 1-N-phenylnaphthylamine (NPN) uptake assays. However, treatment with MGS extract did increase NPN uptake, indicating OM destabilization possibly by additional unknown components. Furthermore, quercetin was found to enter H. pylori as measured by HPLC supporting intracellular drug accumulation. CONCLUSIONS Quercetin and resveratrol possess strong anti-H. pylori activity in vitro and are independent of pH. Our results also suggest that these compounds do not affect H. pylori OM integrity as previously hypothesized and that the primary antimicrobial activity of quercetin may be linked to interactions with intracellular components. SIGNIFICANCE AND IMPACT OF THE STUDY The anti-H. pylori effects of quercetin and resveratrol suggest that these compounds may be useful in the dietary prevention and/or treatment of H. pylori infection.
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Affiliation(s)
- J C Brown
- Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA
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Figura N, Marcolongo R, Cavallo G, Santucci A, Collodel G, Spreafico A, Moretti E. Polysorbate 80 and Helicobacter pylori: a microbiological and ultrastructural study. BMC Microbiol 2012; 12:217. [PMID: 22998649 PMCID: PMC3537525 DOI: 10.1186/1471-2180-12-217] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Accepted: 09/14/2012] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND The frequent occurrence of chemoresistant strains reduces the chances of eradication of H. pylori infection and prompted the investigation of non-antibiotic substances active against this organism. Some surfactants enhance the effectiveness of antibiotics for their permeabilizing properties towards bacteria. We examined the antimicrobial activity to H. pylori of the surfactant polysorbate 80, used alone and in association with amoxicillin, clarithromycin, metronidazole, levofloxacin and tetracycline. We also aimed to study the ultrastructural alterations caused upon H. pylori by polysorbate 80, alone and in combination with antibiotics. Twenty-two H. pylori strains were tested using the broth dilution method. After incubation, broth from each dilution was subcultured onto agar enriched with foetal bovine serum to determine the minimum bactericidal concentration (MBC). Synergistic effect of polysorbate 80 with antibiotics was investigated by the broth dilution and disc diffusion techniques. Ultrastructural alterations of organisms treated with polysorbate 80, alone and in association with antibiotics were analyzed by transmission electron microscopy. RESULTS MBCs of polysorbate 80 ranged from 2.6 (1.1) μg/ml to 32 (0) μg/ml. Polysorbate 80 exerted a synergistic effect when associated with metronidazole and clarithromycin: polysorbate 80 and metronidazole MBCs decreased by ≥ 4 fold; clarithromycin MBCs for two resistant strains decreased by 20 and 1000 times. The principal alteration caused by polysorbate 80 consisted in the detachment of the outer membrane of bacteria. CONCLUSIONS The bactericidal activity of polysorbate 80 and the synergistic effect of the association with metronidazole and clarithromycin could be useful in the treatment of H. pylori infection.
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Affiliation(s)
- Natale Figura
- Department of Internal Medicine, University of Siena, Siena, Italy.
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Garcia M, Raymond J, Garnier M, Cremniter J, Burucoa C. Distribution of spontaneous gyrA mutations in 97 fluoroquinolone-resistant Helicobacter pylori isolates collected in France. Antimicrob Agents Chemother 2012; 56:550-1. [PMID: 22064536 PMCID: PMC3256052 DOI: 10.1128/aac.05243-11] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Accepted: 10/24/2011] [Indexed: 01/30/2023] Open
Abstract
We determined the prevalence of gyrA mutations conferring fluoroquinolone resistance in 97 Helicobacter pylori isolates collected in France from 2007 to 2010. Ninety-four harbored one or two mutations already found in the quinolone resistance determining region (QRDR) of gyrA (for T87I, n = 23; for N87K, n = 32; for D91N, n = 30; for D91G, n = 7; for D91Y, n = 6), 2 harbored a mutation never previously described (D91H and A88P), and one strain was resistant (ciprofloxacin MIC of 8 mg/liter) without a detected mutation conferring this resistance in gyrA or gyrB genes.
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Affiliation(s)
- Magali Garcia
- EA 4331 LITEC, Université de Poitiers, CHU de Poitiers, Laboratoire de Bactériologie-Hygiène, Poitiers, France
| | - Josette Raymond
- CHU Cochin Port Royal, Unité Postulante de Pathogénèse de Helicobacter, Institut Pasteur, Paris, France
| | - Martine Garnier
- EA 4331 LITEC, Université de Poitiers, CHU de Poitiers, Laboratoire de Bactériologie-Hygiène, Poitiers, France
| | - Julie Cremniter
- EA 4331 LITEC, Université de Poitiers, CHU de Poitiers, Laboratoire de Bactériologie-Hygiène, Poitiers, France
| | - Christophe Burucoa
- EA 4331 LITEC, Université de Poitiers, CHU de Poitiers, Laboratoire de Bactériologie-Hygiène, Poitiers, France
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Yu C, Li L, Chen W, Jiao Y, Yang N, Yang E, Zhang J, Chen L, Li Y. Levofloxacin susceptibility testing for Helicobacter pylori in China: comparison of E-test and disk diffusion method. Helicobacter 2011; 16:119-23. [PMID: 21435089 DOI: 10.1111/j.1523-5378.2011.00820.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND The aims of this study were to compare disk diffusion with E-test method for levofloxacin susceptibility testing of Helicobacter pylori and standardized breakpoints for disk diffusion as a stable and reliable method for determining qualitative levofloxacin susceptibility. MATERIALS AND METHODS We determined the levofloxacin susceptibility of 45 H. pylori strains isolated from Chinese patients by the E-test method. Disk diffusion was evaluated as an alternative method to determine susceptibility and compared with the E-test results by linear regression analysis. RESULTS The minimum inhibitory concentration (MIC) values tested by E-test method ranged from 0.047 to 32 μg/mL. Resistance to levofloxacin was detected in 16 (35.6%) isolates. The levofloxacin disk zone sizes obtained by disk diffusion method correlated well (r² = .877) with the MICs obtained by E-test method. As a consequence of regression analysis, isolates with inhibition diameters < 12 mm were considered resistant to levofloxacin. There was 100% agreement between the two methods for levofloxacin, applying the regression-based breakpoints. CONCLUSIONS The disk diffusion method is equivalent to the E-test method for testing levofloxacin susceptibility of H. pylori strains; it is more practical and inexpensive, and it is suitable for the analysis of a small number of isolates compared with the E-test method.
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Affiliation(s)
- Chaohui Yu
- Department of Gastroenterology, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
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Tsugawa H, Suzuki H, Muraoka H, Ikeda F, Hirata K, Matsuzaki J, Saito Y, Hibi T. Enhanced bacterial efflux system is the first step to the development of metronidazole resistance in Helicobacter pylori. Biochem Biophys Res Commun 2010; 404:656-60. [PMID: 21147064 DOI: 10.1016/j.bbrc.2010.12.034] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2010] [Accepted: 12/07/2010] [Indexed: 10/18/2022]
Abstract
Although metronidazole (Mtz) is an important component of Helicobacter pylori eradication regimens, it has been pointed out that the increasing use of Mtz may result in increase in the incidence of Mtz-resistant strains. The present study was designed to examine the initial mechanism of resistance acquisition of H. pylori to Mtz. After 10 Mtz-susceptible strains were cultured on plates containing sub-inhibitory concentrations of Mtz, the MIC of Mtz for 9 of the 10 strains increased to levels of the Mtz-resistant strains. In the Mtz-resistance-induced strains, the expression of the TolC efflux pump (hefA) was significantly increased under Mtz exposure, without the reduction of the Mtz-reductive activity. Our finding suggests that overexpression of hefA may be the initial step in the acquisition of Mtz resistance in H. pylori.
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Affiliation(s)
- Hitoshi Tsugawa
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine, Tokyo, Japan
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