1
|
Huang J, Li Z, Ge F, Sun C, Deng Z, Yao W, He X. Functional determination of site-mutations in rdxA involved in metronidazole resistance of Helicobacter pylori. Front Cell Dev Biol 2024; 12:1435064. [PMID: 39100097 PMCID: PMC11294100 DOI: 10.3389/fcell.2024.1435064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2024] [Accepted: 07/01/2024] [Indexed: 08/06/2024] Open
Abstract
Background Metronidazole (MTZ) is among the first-line drugs against the human gastric pathogen Helicobacter pylori (H. pylori). MTZ is used as a prodrug that is activated by an oxygen-insensitive enzyme NADPH nitroreductase (RdxA). Loss-of-function mutations in rdxA make H. pylori MTZ resistant; however, experimental proof is lacking. Methods We collected 139 gastric biopsy samples from patients suspected of H. pylori infection in Shanghai, and amplified Hp-specific rdxA gene from 134 samples. All these rdxA genes were sequenced and phylogenetically compared. The effect of mutations on RdxA function was measured by expressing them in Escherichia coli DH5α by using the MTZ sensitivity test. Results In total, 134 gastric biopsy samples were identified as H. pylori positive. Of the 134 samples, 74 and 6 had point mutations at the various sites or promoter region of rdxA, generating truncated and extended fused proteins, respectively. The remaining 54 were full-length with single nucleotide variation (SNV) compared with the wild-type RdxA from H. pylori, with 49 clustering with hpEastAsia, 3 with hpEurope, and 2 with hpNEAfrica. All 134 rdxA were expressed in E. coli DH5α; 22 and 112 resultant strains showed MTZ-sensitive and MTZ-resistant phenotypes, respectively. Comparative analysis of single nucleotide polymorphisms (SNPs) in the functional and inactivated RdxA revealed 14 novel mutations in RdxA, 5 of which conferred MTZ resistance: S18F, D59S, L62I, S79N, and A187V. Conclusion The occurrence of MTZ resistance induced by site-mutation of RdxA in patients with H. pylori infection was 83.6% (112/134) in the Shanghai region. The major form of loss-of-function mutation was truncation of RdxA translation at a rate of 58/112 (51.8%). Molecular detection reliably determined the resistance of H. pylori to MTZ. Thus, the functional mutants involved in MTZ resistance facilitate clinical diagnosis and medication based on sequence analysis.
Collapse
Affiliation(s)
- Jia Huang
- Department of Gastroenterology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhiyu Li
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Fulin Ge
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Chao Sun
- Department of Gastroenterology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zixin Deng
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Weiyan Yao
- Department of Gastroenterology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xinyi He
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| |
Collapse
|
2
|
Umar Z, Tang JW, Marshall BJ, Tay ACY, Wang L. Rapid diagnosis and precision treatment of Helicobacter pylori infection in clinical settings. Crit Rev Microbiol 2024:1-30. [PMID: 38910506 DOI: 10.1080/1040841x.2024.2364194] [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: 02/28/2024] [Accepted: 05/25/2024] [Indexed: 06/25/2024]
Abstract
Helicobacter pylori is a gram-negative bacterium that colonizes the stomach of approximately half of the worldwide population, with higher prevalence in densely populated areas like Asia, the Caribbean, Latin America, and Africa. H. pylori infections range from asymptomatic cases to potentially fatal diseases, including peptic ulcers, chronic gastritis, and stomach adenocarcinoma. The management of these conditions has become more difficult due to the rising prevalence of drug-resistant H. pylori infections, which ultimately lead to gastric cancer and mucosa-associated lymphoid tissue (MALT) lymphoma. In 1994, the International Agency for Research on Cancer (IARC) categorized H. pylori as a Group I carcinogen, contributing to approximately 780,000 cancer cases annually. Antibiotic resistance against drugs used to treat H. pylori infections ranges between 15% and 50% worldwide, with Asian countries having exceptionally high rates. This review systematically examines the impacts of H. pylori infection, the increasing prevalence of antibiotic resistance, and the urgent need for accurate diagnosis and precision treatment. The present status of precision treatment strategies and prospective approaches for eradicating infections caused by antibiotic-resistant H. pylori will also be evaluated.
Collapse
Affiliation(s)
- Zeeshan Umar
- Marshall Laboratory of Biomedical Engineering, School of Medicine, Shenzhen University, Shenzhen, Guangdong Province, China
- Laboratory Medicine, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, Guangdong Province, China
| | - Jia-Wei Tang
- Laboratory Medicine, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, Guangdong Province, China
- The Marshall Centre for Infectious Diseases Research and Training, The University of Western Australia, Crawley, Western Australia, China
| | - Barry J Marshall
- Marshall Laboratory of Biomedical Engineering, School of Medicine, Shenzhen University, Shenzhen, Guangdong Province, China
- The Marshall Centre for Infectious Diseases Research and Training, The University of Western Australia, Crawley, Western Australia, China
- Marshall International Digestive Diseases Hospital, Zhengzhou University, Zhengzhou, Henan Province, China
- Marshall Medical Research Center, Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China
| | - Alfred Chin Yen Tay
- Marshall Laboratory of Biomedical Engineering, School of Medicine, Shenzhen University, Shenzhen, Guangdong Province, China
- The Marshall Centre for Infectious Diseases Research and Training, The University of Western Australia, Crawley, Western Australia, China
- Marshall International Digestive Diseases Hospital, Zhengzhou University, Zhengzhou, Henan Province, China
- Marshall Medical Research Center, Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China
| | - Liang Wang
- Laboratory Medicine, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, Guangdong Province, China
- Division of Microbiology and Immunology, School of Biomedical Sciences, The University of Western Australia, Crawley, Western Australia, China
- Center for Precision Health, School of Medical and Health Sciences, Edith Cowan University, Joondalup, Western Australia, China
- School of Agriculture and Food Sustainability, University of Queensland, Brisbane, Queensland, Australia
| |
Collapse
|
3
|
Tong Q, Yin C, Hang X, Bai Y, Zhang C, Xu J, Huang Y, Ge Y, Chen T, Zeng L, Jia J, Bi H. Loureirin A is a narrow-spectrum antimicrobial agent against Helicobacter pylori. Antimicrob Agents Chemother 2024:e0031424. [PMID: 38656185 DOI: 10.1128/aac.00314-24] [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: 03/07/2024] [Accepted: 03/31/2024] [Indexed: 04/26/2024] Open
Abstract
Currently, Helicobacter pylori eradication by antibiotic therapy faces various challenges, including antibiotic resistance, side effects on intestinal commensal bacteria, and patient compliance. In this study, loureirin A (LrA), a traditional Chinese medicine monomer extracted from Sanguis Draconis flavones, was found to possess specific antibacterial activity against H. pylori without the bacteria displaying a tendency to develop resistance in vitro. LrA demonstrated a synergistic or additive effect when combined with omeprazole (a proton pump inhibitor) against H. pylori. The combination of LrA and omeprazole showed promising anti-H. pylori potential, exhibiting notable in vivo efficacy comparable to standard triple therapy in mouse models infected with both drug-sensitive and drug-resistant H. pylori strains. Moreover, the narrow-spectrum antibacterial profile of LrA is reflected in its minimal effect on the diversity and composition of the mouse gut microbiota. The underlying mechanism of action of LrA against H. pylori involves the generation of bactericidal levels of reactive oxygen species, resulting in apoptosis-like cell death. These findings indicate that LrA is a promising lead compound targeting H. pylori without harming the commensal bacteria.
Collapse
Affiliation(s)
- Qian Tong
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, China
- Helicobacter pylori Research Center, Nanjing Medical University, Nanjing, China
| | - Chengqiang Yin
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, China
- Helicobacter pylori Research Center, Nanjing Medical University, Nanjing, China
- Department of Gastroenterology, First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Xudong Hang
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, China
- Helicobacter pylori Research Center, Nanjing Medical University, Nanjing, China
| | - Yuefan Bai
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, China
- Helicobacter pylori Research Center, Nanjing Medical University, Nanjing, China
| | - Chongwen Zhang
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, China
- Helicobacter pylori Research Center, Nanjing Medical University, Nanjing, China
| | - Jingcheng Xu
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, China
- Helicobacter pylori Research Center, Nanjing Medical University, Nanjing, China
| | - Yan Huang
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, China
- Helicobacter pylori Research Center, Nanjing Medical University, Nanjing, China
| | - Yixin Ge
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, China
- Helicobacter pylori Research Center, Nanjing Medical University, Nanjing, China
| | - Tianyu Chen
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, China
- Helicobacter pylori Research Center, Nanjing Medical University, Nanjing, China
| | - Liping Zeng
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, China
- Helicobacter pylori Research Center, Nanjing Medical University, Nanjing, China
| | - Jia Jia
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, China
- Helicobacter pylori Research Center, Nanjing Medical University, Nanjing, China
| | - Hongkai Bi
- Department of Pathogen Biology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, China
- Helicobacter pylori Research Center, Nanjing Medical University, Nanjing, China
| |
Collapse
|
4
|
Hasanuzzaman M, Bang CS, Gong EJ. Antibiotic Resistance of Helicobacter pylori: Mechanisms and Clinical Implications. J Korean Med Sci 2024; 39:e44. [PMID: 38288543 PMCID: PMC10825452 DOI: 10.3346/jkms.2024.39.e44] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 12/29/2023] [Indexed: 02/01/2024] Open
Abstract
Helicobacter pylori is a pathogenic bacterium associated with various gastrointestinal diseases, including chronic gastritis, peptic ulcers, mucosa-associated lymphoid tissue lymphoma, and gastric cancer. The increasing rates of H. pylori antibiotic resistance and the emergence of multidrug-resistant strains pose significant challenges to its treatment. This comprehensive review explores the mechanisms underlying the resistance of H. pylori to commonly used antibiotics and the clinical implications of antibiotic resistance. Additionally, potential strategies for overcoming antibiotic resistance are discussed. These approaches aim to improve the treatment outcomes of H. pylori infections while minimizing the development of antibiotic resistance. The continuous evolution of treatment perspectives and ongoing research in this field are crucial for effectively combating this challenging infection.
Collapse
Affiliation(s)
- Md Hasanuzzaman
- Department of Internal Medicine, Hallym University College of Medicine, Chuncheon, Korea
| | - Chang Seok Bang
- Department of Internal Medicine, Hallym University College of Medicine, Chuncheon, Korea
| | - Eun Jeong Gong
- Department of Internal Medicine, Hallym University College of Medicine, Chuncheon, Korea.
| |
Collapse
|
5
|
Jacob TV, Doshi GM. A Mini-review on Helicobacter pylori with Gastric Cancer and Available Treatments. Endocr Metab Immune Disord Drug Targets 2024; 24:277-290. [PMID: 37622707 DOI: 10.2174/1871530323666230824161901] [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: 05/30/2023] [Revised: 07/22/2023] [Accepted: 07/26/2023] [Indexed: 08/26/2023]
Abstract
Helicobacter pylori (H. pylori) is the most thoroughly researched etiological component for stomach inflammation and malignancies. Even though there are conventional recommendations and treatment regimens for eradicating H. pylori, failure rates continue to climb. Antibiotic resistance contributes significantly to misdiagnoses, false positive results, and clinical failures, all of which raise the chance of infection recurrence. This review aims to explore the molecular mechanisms underlying drug resistance in H. pylori and discuss novel approaches for detecting genotypic resistance. Modulation of drug uptake/ efflux, biofilm, and coccoid development. Newer genome sequencing approaches capable of detecting H. pylori genotypic resistance are presented. Prolonged infection in the stomach causes major problems such as gastric cancer. The review discusses how H. pylori causes stomach cancer, recent biomarkers such as miRNAs, molecular pathways in the development of gastric cancer, and diagnostic methods and clinical trials for the disease. Efforts have been made to summarize the recent advancements made toward early diagnosis and novel therapeutic approaches for H. pylori-induced gastric cancer.
Collapse
Affiliation(s)
- Teresa V Jacob
- Department of Pharmacology, SVKM's Dr. Bhanuben Nanavati College of Pharmacy, V.M. Road, Vile Parle (W), Mumbai, 400056, India
| | - Gaurav M Doshi
- Department of Pharmacology, SVKM's Dr. Bhanuben Nanavati College of Pharmacy, V.M. Road, Vile Parle (W), Mumbai, 400056, India
| |
Collapse
|
6
|
Gong Y, Zhai K, Sun L, He L, Wang H, Guo Y, Zhang J. RdxA Diversity and Mutations Associated with Metronidazole Resistance of Helicobacter pylori. Microbiol Spectr 2023; 11:e0390322. [PMID: 36943041 PMCID: PMC10100817 DOI: 10.1128/spectrum.03903-22] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Accepted: 02/15/2023] [Indexed: 03/23/2023] Open
Abstract
Metronidazole (MNZ) is administered as first-line antibiotic for Helicobacter pylori eradication therapy; however, increasing resistance to MNZ impaired the efficacy. Increasing the dose of MNZ was recommended to overcome low-level resistance, but it was difficult to determine MNZ resistance level simply based on the rdxA gene mutation. In this study, the rdxA sequences of 511 clinical H. pylori strains were analyzed to assess the genotypes associated with MNZ resistance. We observed that the prevalences of rdxA sequences with missense, nonsense, and frameshift mutations were 70.25, 11.35, and 17.03%, respectively. Regarding the amino acid substitutions, T31E, H53R, D59N, L62V, S88P, G98S/N, R131K, and V172I were present in most strains regardless of the resistance phenotype. The correlation analysis showed R16H/C, Y47C, A67V/T, and V204I substitutions were associated with MNZ resistance. The mutation resulting in RdxA truncation was observed in 36.29% of the resistant strains, and 83.45% of these strains displayed high-level MNZ resistance (MIC > 256 μg/mL). Moreover, all strains with truncated mutation positions before amino acid 70 expressed high-level MNZ resistance. Our results indicated that most amino acid mutations probably contributed to the sequence diversity of RdxA, while R16H/C, Y47C, A67V/T, and V204I were potentially helpful to identify resistant strains. Although it was difficult to determine the mutations associated with MNZ resistance, the prediction of high-level resistance based on truncated characteristics of RdxA might be an important approach, which can effectively avoid H. pylori eradication therapy with unreasonable of MNZ dose increases for patients with high-level drug resistance. IMPORTANCE The increasing resistance to metronidazole impaired the efficacy of Helicobacter pylori eradication, and increasing the dose of metronidazole was recommended to overcome low-level resistance. For patients infected with highly resistant strains, the current empirical treatments, which generally used metronidazole in double doses or more, appeared impossibly to overcome the resistance and would only increase the incidence of adverse effects. Our results indicated that high-level metronidazole resistance was predominant, and almost half of the patients with high-level drug resistance could avoid usage of metronidazole based on the truncated mutations of RdxA sequences, which can effectively avoid H. pylori eradication therapy with unreasonable increases in the metronidazole dose.
Collapse
Affiliation(s)
- Yanan Gong
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Kangle Zhai
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Lu Sun
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Lihua He
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Hairui Wang
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Yahui Guo
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Jianzhong Zhang
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| |
Collapse
|
7
|
Srisuphanunt M, Wilairatana P, Kooltheat N, Duangchan T, Katzenmeier G, Rose JB. Molecular Mechanisms of Antibiotic Resistance and Novel Treatment Strategies for Helicobacter pylori Infections. Trop Med Infect Dis 2023; 8:163. [PMID: 36977164 PMCID: PMC10057134 DOI: 10.3390/tropicalmed8030163] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Revised: 03/06/2023] [Accepted: 03/06/2023] [Indexed: 03/18/2023] Open
Abstract
Helicobacter pylori infects approximately 50% of the world's population and is considered the major etiological agent of severe gastric diseases, such as peptic ulcers and gastric carcinoma. Increasing resistance to standard antibiotics has now led to an ever-decreasing efficacy of eradication therapies and the development of novel and improved regimens for treatment is urgently required. Substantial progress has been made over the past few years in the identification of molecular mechanisms which are conducive to resistant phenotypes as well as for efficient strategies to counteract strain resistance and to avoid the use of ineffective antibiotics. These involve molecular testing methods, improved salvage therapies, and the discovery of novel and potent antimicrobial compounds. High rates of prevalence and gastric cancer are currently observed in Asian countries, including Japan, China, Korea, and Taiwan, where concomitantly intensive research efforts were initiated to explore advanced eradication regimens aimed at reducing the risk of gastric cancer. In this review, we present an overview of the known molecular mechanisms of antibiotic resistance and discuss recent intervention strategies for H. pylori diseases, with a view of the research progress in Asian countries.
Collapse
Affiliation(s)
- Mayuna Srisuphanunt
- Department of Medical Technology, School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat 80160, Thailand
- Excellent Center for Dengue and Community Public Health, School of Public Health, Walailak University, Nakhon Si Thammarat 80160, Thailand
| | - Polrat Wilairatana
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | - Nateelak Kooltheat
- Department of Medical Technology, School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat 80160, Thailand
- Hematology and Transfusion Science Research Center, School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat 80160, Thailand
| | - Thitinat Duangchan
- Department of Medical Technology, School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat 80160, Thailand
- Hematology and Transfusion Science Research Center, School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat 80160, Thailand
| | - Gerd Katzenmeier
- Akkhraratchakumari Veterinary College, Walailak University, Nakhon Si Thammarat 80160, Thailand
| | - Joan B. Rose
- Department of Fisheries and Wildlife, Michigan State University, East Lansing, MI 48823, USA
| |
Collapse
|
8
|
Koshak YF, Benedykt VV, Prodan AM, Dzhyvak VG, Nikitina IM. CAUSES OF SUPERINFECTIONS: DEADLY BACTERIA OF TUBERCULOSIS. WIADOMOSCI LEKARSKIE (WARSAW, POLAND : 1960) 2022; 75:2817-2825. [PMID: 36591773 DOI: 10.36740/wlek202211216] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
OBJECTIVE The aim: To improve early diagnosis of drug-resistant superbacteria and interrupt the ways of its formation through molecular technological and surgical methods. PATIENTS AND METHODS Materials and methods: The operated patients were divided into two groups: group 1 - 351 (51.25 %) patients, who were operated with the use of minimally invasive technologies, and this was the main group; group 2 - 334 (48.75 %) patients who were operated on open wide thoracotomy, which was the comparison group. Among 351 patients in the main group, in 301 - acute pleural tuberculous empyema was detected, and in 50 - chronic one. Among patients in the comparison group, acute pleural empyema was observed in 284 patients and chronic in 50 patients. RESULTS Results: According to our data, video thoracoscopy is a highly informative method of diagnosis of pleural effusions, detection of pleural tuberculous empyema in the first, second and third stages of its development. CONCLUSION Conclusions: The introduction of modern molecular-geneticand surgical technologies will allow to accurately establish the etiology process, to conduct the identification of pathogen microorganisms and to determine the phenotymetric and genotytypical sensitivity of bacteria to Antimycobacterial drugs. Such diagnostics will promote effective treatment of patients who are already infected with persistent strains of bacteria and viruses.
Collapse
Affiliation(s)
- Yuriy F Koshak
- IHORBACHEVSKY TERNOPIL NATIONAL MEDICAL UNIVERSITY, TERNOPIL, UKRAINE
| | | | - Andrii M Prodan
- IHORBACHEVSKY TERNOPIL NATIONAL MEDICAL UNIVERSITY, TERNOPIL, UKRAINE
| | | | | |
Collapse
|
9
|
Defenses of multidrug resistant pathogens against reactive nitrogen species produced in infected hosts. Adv Microb Physiol 2022; 80:85-155. [PMID: 35489794 DOI: 10.1016/bs.ampbs.2022.02.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Bacterial pathogens have sophisticated systems that allow them to survive in hosts in which innate immunity is the frontline of defense. One of the substances produced by infected hosts is nitric oxide (NO) that together with its derived species leads to the so-called nitrosative stress, which has antimicrobial properties. In this review, we summarize the current knowledge on targets and protective systems that bacteria have to survive host-generated nitrosative stress. We focus on bacterial pathogens that pose serious health concerns due to the growing increase in resistance to currently available antimicrobials. We describe the role of nitrosative stress as a weapon for pathogen eradication, the detoxification enzymes, protein/DNA repair systems and metabolic strategies that contribute to limiting NO damage and ultimately allow survival of the pathogen in the host. Additionally, this systematization highlights the lack of available data for some of the most important human pathogens, a gap that urgently needs to be addressed.
Collapse
|
10
|
Ma Z, He S, Yuan Y, Zhuang Z, Liu Y, Wang H, Chen J, Xu X, Ding C, Molodtsov V, Lin W, Robertson GT, Weiss WJ, Pulse M, Nguyen P, Duncan L, Doyle T, Ebright RH, Lynch AS. Design, Synthesis, and Characterization of TNP-2198, a Dual-Targeted Rifamycin-Nitroimidazole Conjugate with Potent Activity against Microaerophilic and Anaerobic Bacterial Pathogens. J Med Chem 2022; 65:4481-4495. [PMID: 35175750 PMCID: PMC8958509 DOI: 10.1021/acs.jmedchem.1c02045] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
![]()
TNP-2198, a stable
conjugate of a rifamycin pharmacophore and a
nitroimidazole pharmacophore, has been designed, synthesized, and
evaluated as a novel dual-targeted antibacterial agent for the treatment
of microaerophilic and anaerobic bacterial infections. TNP-2198 exhibits
greater activity than a 1:1 molar mixture of the parent drugs and
exhibits activity against strains resistant to both rifamycins and
nitroimidazoles. A crystal structure of TNP-2198 bound to a Mycobacterium tuberculosis RNA polymerase transcription
initiation complex reveals that the rifamycin portion of TNP-2198
binds to the rifamycin binding site on RNAP and the nitroimidazole
portion of TNP-2198 interacts directly with the DNA template-strand
in the RNAP active-center cleft, forming a hydrogen bond with a base
of the DNA template strand. TNP-2198 is currently in Phase 2 clinical
development for the treatment of Helicobacter pylori infection, Clostridioides difficile infection,
and bacterial vaginosis.
Collapse
Affiliation(s)
- Zhenkun Ma
- TenNor Therapeutics Ltd, 218 Xinghu Street, Suzhou Industrial Park, Suzhou 215123, China
| | - Shijie He
- TenNor Therapeutics Ltd, 218 Xinghu Street, Suzhou Industrial Park, Suzhou 215123, China
| | - Ying Yuan
- TenNor Therapeutics Ltd, 218 Xinghu Street, Suzhou Industrial Park, Suzhou 215123, China
| | - Zhijun Zhuang
- TenNor Therapeutics Ltd, 218 Xinghu Street, Suzhou Industrial Park, Suzhou 215123, China
| | - Yu Liu
- TenNor Therapeutics Ltd, 218 Xinghu Street, Suzhou Industrial Park, Suzhou 215123, China
| | - Huan Wang
- TenNor Therapeutics Ltd, 218 Xinghu Street, Suzhou Industrial Park, Suzhou 215123, China
| | - Jing Chen
- TenNor Therapeutics Ltd, 218 Xinghu Street, Suzhou Industrial Park, Suzhou 215123, China
| | - Xiangyi Xu
- TenNor Therapeutics Ltd, 218 Xinghu Street, Suzhou Industrial Park, Suzhou 215123, China
| | - Charles Ding
- TenNor Therapeutics Ltd, 218 Xinghu Street, Suzhou Industrial Park, Suzhou 215123, China
| | - Vadim Molodtsov
- Waksman Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, United States
| | - Wei Lin
- Waksman Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, United States
| | - Gregory T Robertson
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, 80523-1682, United States
| | - William J Weiss
- HSC College of Pharmacy, University of North Texas, Fort Worth, Texas 76107, United States
| | - Mark Pulse
- HSC College of Pharmacy, University of North Texas, Fort Worth, Texas 76107, United States
| | - Phung Nguyen
- HSC College of Pharmacy, University of North Texas, Fort Worth, Texas 76107, United States
| | - Leonard Duncan
- JMI Laboratories, North Liberty, Iowa 52317, United States
| | - Timothy Doyle
- JMI Laboratories, North Liberty, Iowa 52317, United States
| | - Richard H Ebright
- Waksman Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, United States
| | - Anthony Simon Lynch
- TenNor Therapeutics Ltd, 218 Xinghu Street, Suzhou Industrial Park, Suzhou 215123, China
| |
Collapse
|
11
|
Liu D, Wanniarachchi TN, Jiang G, Seabra G, Cao S, Bruner SD, Ding Y. Biochemical and structural characterization of Haemophilus influenzae nitroreductase in metabolizing nitroimidazoles. RSC Chem Biol 2022; 3:436-446. [PMID: 35441146 PMCID: PMC8985140 DOI: 10.1039/d1cb00238d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 02/15/2022] [Indexed: 11/21/2022] Open
Abstract
Nitroheterocycle antibiotics, particularly 5-nitroimidazoles, are frequently used for treating anaerobic infections. The antimicrobial activities of these drugs heavily rely on the in vivo bioactivation, mainly mediated by widely distributed bacterial nitroreductases (NTRs). However, the bioactivation can also lead to severe toxicities and drug resistance. Mechanistic understanding of NTR-mediated 5-nitroimidazole metabolism can potentially aid addressing these issues. Here, we report the metabolism of structurally diverse nitroimidazole drug molecules by a NTR from a human pathogen Haemophilus influenzae (HiNfsB). Our detailed bioinformatic analysis uncovered that HiNfsB represents a group of unexplored oxygen-insensitive NTRs. Biochemical characterization of the recombinant enzyme revealed that HiNfsB effectively metabolizes ten clinically used nitroimidazoles. Furthermore, HiNfsB generated not only canonical nitroreduction metabolites but also stable, novel dimeric products from three nitroimidazoles, whose structures were proposed based on the results of high resolution MS and tandem MS analysis. X-ray structural analysis of the enzyme coupled with site-directed mutagenesis identified four active site residues important to its catalysis and broad substrate scope. Finally, transient expression of HiNfsB sensitized an E. coli mutant strain to 5-nitroimidazoles under anaerobic conditions. Together, these results advance our understanding of the metabolism of nitroimidazole antibiotics mediated by a new NTR group and reinforce the research on the natural antibiotic resistome for addressing the antibiotic resistance crisis. The nitroreductase of Haemophilus influenzae metabolizes clinically used nitroimidazoles, generates dimeric metabolites and anaerobically sensitizes an E. coli mutant to antibiotics. We further uncover its biochemical and structural details.![]()
Collapse
Affiliation(s)
- Dake Liu
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development (CNPD3), University of Florida, Gainesville, Florida, 32610, USA
| | | | - Guangde Jiang
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development (CNPD3), University of Florida, Gainesville, Florida, 32610, USA
| | - Gustavo Seabra
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development (CNPD3), University of Florida, Gainesville, Florida, 32610, USA
| | - Shugeng Cao
- Department of Pharmaceutical Sciences, University of Hawai'i at Hilo, Hilo, Hawaii, 96720, USA
| | - Steven D. Bruner
- Department of Chemistry, University of Florida, Gainesville, Florida, 32611, USA
| | - Yousong Ding
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development (CNPD3), University of Florida, Gainesville, Florida, 32610, USA
| |
Collapse
|
12
|
Liu T, Wang Y, Feng L, Tian X, Cui J, Yu Z, Wang C, Zhang B, James TD, Ma X. 2D Strategy for the Construction of an Enzyme-Activated NIR Fluorophore Suitable for the Visual Sensing and Profiling of Homologous Nitroreductases from Various Bacterial Species. ACS Sens 2021; 6:3348-3356. [PMID: 34469146 PMCID: PMC8477384 DOI: 10.1021/acssensors.1c01216] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 08/19/2021] [Indexed: 12/15/2022]
Abstract
Nitroreductases (NTRs) mediate the reduction of nitroaromatic compounds to the corresponding nitrite, hydroxylamine, or amino derivatives. The activity of NTRs in bacteria facilitates the metabolic activation and antibacterial activity of 5-nitroimidazoles. Therefore, NTR activity correlates with the drug susceptibility and resistance of pathogenic bacteria. As such, it is important to develop a rapid and visual assay for the real-time sensing of bacterial NTRs for the evaluation and development of antibiotics. Herein, an activatable near-infrared fluorescent probe (HC-NO2) derived from a hemicyanine fluorophore was designed and developed based on two evaluation factors, including the calculated partition coefficient (Clog P) and fluorescence wavelength. Using HC-NO2 as the special substrate of NTRs, NTR activity can be assayed efficiently, and then, bacteria can be imaged based on the detection of NTRs. More importantly, a sensitive in-gel assay using HC-NO2 has been developed to selectively identify NTRs and sensitively determine NTR activity. Using the in-gel assay, NTRs from various bacterial species have been profiled visually from the "fluorescence fingerprints", which facilitates the rapid identification of NTRs from bacterial lysates. Thus, various homologous NTRs were identified from three metronidazole-susceptible bacterial species as well as seven unsusceptible species, which were confirmed by the whole-genome sequence. As such, the evaluation of NTRs from different bacterial species should help improve the rational usage of 5-nitroimidazole drugs as antibiotics.
Collapse
Affiliation(s)
- Tao Liu
- Dalian
Key Laboratory of Metabolic Target Characterization and Traditional
Chinese Medicine Intervention, College of Pharmacy, Dalian Medical University, Dalian 116044, China
- State
Key Laboratory of Fine Chemicals, Dalian
University of Technology, Dalian 116024, China
| | - Yifei Wang
- Dalian
Key Laboratory of Metabolic Target Characterization and Traditional
Chinese Medicine Intervention, College of Pharmacy, Dalian Medical University, Dalian 116044, China
| | - Lei Feng
- Dalian
Key Laboratory of Metabolic Target Characterization and Traditional
Chinese Medicine Intervention, College of Pharmacy, Dalian Medical University, Dalian 116044, China
| | - Xiangge Tian
- Dalian
Key Laboratory of Metabolic Target Characterization and Traditional
Chinese Medicine Intervention, College of Pharmacy, Dalian Medical University, Dalian 116044, China
| | - Jingnan Cui
- State
Key Laboratory of Fine Chemicals, Dalian
University of Technology, Dalian 116024, China
| | - Zhenlong Yu
- Dalian
Key Laboratory of Metabolic Target Characterization and Traditional
Chinese Medicine Intervention, College of Pharmacy, Dalian Medical University, Dalian 116044, China
| | - Chao Wang
- Dalian
Key Laboratory of Metabolic Target Characterization and Traditional
Chinese Medicine Intervention, College of Pharmacy, Dalian Medical University, Dalian 116044, China
| | - Baojing Zhang
- Dalian
Key Laboratory of Metabolic Target Characterization and Traditional
Chinese Medicine Intervention, College of Pharmacy, Dalian Medical University, Dalian 116044, China
| | - Tony D. James
- Department
of Chemistry, University of Bath, Bath BA2 7AY, U.K.
- School
of Chemistry and Chemical Engineering, Henan
Normal University, Xinxiang 453007, China
| | - Xiaochi Ma
- Dalian
Key Laboratory of Metabolic Target Characterization and Traditional
Chinese Medicine Intervention, College of Pharmacy, Dalian Medical University, Dalian 116044, China
- Jiangsu
Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou 221004, China
| |
Collapse
|
13
|
Tshibangu-Kabamba E, Yamaoka Y. Helicobacter pylori infection and antibiotic resistance - from biology to clinical implications. Nat Rev Gastroenterol Hepatol 2021; 18:613-629. [PMID: 34002081 DOI: 10.1038/s41575-021-00449-x] [Citation(s) in RCA: 193] [Impact Index Per Article: 64.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/31/2021] [Indexed: 02/06/2023]
Abstract
Helicobacter pylori is a major human pathogen for which increasing antibiotic resistance constitutes a serious threat to human health. Molecular mechanisms underlying this resistance have been intensively studied and are discussed in this Review. Three profiles of resistance - single drug resistance, multidrug resistance and heteroresistance - seem to occur, probably with overlapping fundamental mechanisms and clinical implications. The mechanisms that have been most studied are related to mutational changes encoded chromosomally and disrupt the cellular activity of antibiotics through target-mediated mechanisms. Other biological attributes driving drug resistance in H. pylori have been less explored and this could imply more complex physiological changes (such as impaired regulation of drug uptake and/or efflux, or biofilm and coccoid formation) that remain largely elusive. Resistance-related attributes deployed by the pathogen cause treatment failures, diagnostic difficulties and ambiguity in clinical interpretation of therapeutic outcomes. Subsequent to the increasing antibiotic resistance, a substantial drop in H. pylori treatment efficacy has been noted globally. In the absence of an efficient vaccine, enhanced efforts are needed for setting new treatment strategies and for a better understanding of the emergence and spread of drug-resistant bacteria, as well as for improving diagnostic tools that can help optimize current antimicrobial regimens.
Collapse
Affiliation(s)
| | - Yoshio Yamaoka
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Oita, Japan. .,Department of Medicine, Gastroenterology and Hepatology Section, Baylor College of Medicine, Houston, TX, USA.
| |
Collapse
|
14
|
Čėnas N, Nemeikaitė-Čėnienė A, Kosychova L. Single- and Two-Electron Reduction of Nitroaromatic Compounds by Flavoenzymes: Mechanisms and Implications for Cytotoxicity. Int J Mol Sci 2021; 22:ijms22168534. [PMID: 34445240 PMCID: PMC8395237 DOI: 10.3390/ijms22168534] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 07/30/2021] [Accepted: 08/04/2021] [Indexed: 12/14/2022] Open
Abstract
Nitroaromatic compounds (ArNO2) maintain their importance in relation to industrial processes, environmental pollution, and pharmaceutical application. The manifestation of toxicity/therapeutic action of nitroaromatics may involve their single- or two-electron reduction performed by various flavoenzymes and/or their physiological redox partners, metalloproteins. The pivotal and still incompletely resolved questions in this area are the identification and characterization of the specific enzymes that are involved in the bioreduction of ArNO2 and the establishment of their contribution to cytotoxic/therapeutic action of nitroaromatics. This review addresses the following topics: (i) the intrinsic redox properties of ArNO2, in particular, the energetics of their single- and two-electron reduction in aqueous medium; (ii) the mechanisms and structure-activity relationships of reduction in ArNO2 by flavoenzymes of different groups, dehydrogenases-electrontransferases (NADPH:cytochrome P-450 reductase, ferredoxin:NADP(H) oxidoreductase and their analogs), mammalian NAD(P)H:quinone oxidoreductase, bacterial nitroreductases, and disulfide reductases of different origin (glutathione, trypanothione, and thioredoxin reductases, lipoamide dehydrogenase), and (iii) the relationships between the enzymatic reactivity of compounds and their activity in mammalian cells, bacteria, and parasites.
Collapse
Affiliation(s)
- Narimantas Čėnas
- Institute of Biochemistry of Vilnius University, Saulėtekio 7, LT-10257 Vilnius, Lithuania;
- Correspondence: ; Tel.: +370-5-223-4392
| | - Aušra Nemeikaitė-Čėnienė
- State Research Institute Center for Innovative Medicine, Santariškių St. 5, LT-08406 Vilnius, Lithuania;
| | - Lidija Kosychova
- Institute of Biochemistry of Vilnius University, Saulėtekio 7, LT-10257 Vilnius, Lithuania;
| |
Collapse
|
15
|
Zhang S, Wang X, Wise MJ, He Y, Chen H, Liu A, Huang H, Young S, Tay CY, Marshall BJ, Li X, Chua EG. Mutations of Helicobacter pylori RdxA are mainly related to the phylogenetic origin of the strain and not to metronidazole resistance. J Antimicrob Chemother 2021; 75:3152-3155. [PMID: 32676634 DOI: 10.1093/jac/dkaa302] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 06/09/2020] [Indexed: 12/29/2022] Open
Abstract
OBJECTIVES Drug resistance of Helicobacter pylori is a major clinical problem worldwide. The objective of the present study was to investigate the prevalence of antibiotic-resistant H. pylori in the city of Shenzhen in China, as well as to identify the genetic mutations specifically associated with drug resistance rather than unrelated phylogenetic signals. METHODS Antibiotic susceptibility testing was performed on 238 clinical strains successfully isolated from H. pylori-positive dyspeptic patients who underwent gastroscopy at the Department of Gastroenterology in Shenzhen People's Second Hospital. Following WGS of all strains using Illumina technology, mutation and phylogenetic analyses were performed. RESULTS The resistance rates were 84.9%, 35.3%, 25.2% and 2.1% for metronidazole, clarithromycin, ciprofloxacin and rifampicin, respectively. An A2143G conversion in the 23S rRNA gene was the primary mutation observed in clarithromycin-resistant strains, whilst N87K/I and D91G/N/Y in GyrA were detected in ciprofloxacin-resistant strains. In RdxA, our results demonstrated that only R16H/C and M21A are significant contributors to metronidazole resistance; there were 15 other sites, but these are phylogenetically related and thus unrelated to metronidazole resistance. CONCLUSIONS There is a high prevalence of metronidazole, clarithromycin and ciprofloxacin resistance and a low prevalence of rifampicin resistance in H. pylori from Shenzhen, China. Omission of phylogenetically related sites will help to improve identification of sites genuinely related to antibiotic resistance in H. pylori and, we believe, other species.
Collapse
Affiliation(s)
- Shuzhen Zhang
- Department of Clinical Laboratory, Kuichong People's Hospital, Shenzhen 518119, China
| | - Xiangyu Wang
- Department of Clinical Laboratory, Kuichong People's Hospital, Shenzhen 518119, China.,Department of Gastroenterology, The First Affiliated Hospital of Shenzhen University, Shenzhen People's Second Hospital, Shenzhen 518000, China
| | - Michael J Wise
- Department of Computer Science and Software Engineering, University of Western Australia, Perth 6009, Australia.,The Marshall Centre for Infectious Diseases Research and Training, University of Western Australia, Perth 6009, Australia
| | - Yongsheng He
- Department of Clinical Laboratory, Kuichong People's Hospital, Shenzhen 518119, China
| | - Haiting Chen
- Department of Clinical Laboratory, Kuichong People's Hospital, Shenzhen 518119, China
| | - Aijun Liu
- Department of Gastroenterology, Kuichong People's Hospital, Shenzhen 518119, China
| | - Haiyan Huang
- Department of Clinical Laboratory, Kuichong People's Hospital, Shenzhen 518119, China
| | - Sylvia Young
- Harry Perkins Institute of Medical Research, The University of Western Australia, Perth 6009, Australia
| | - Chin Yen Tay
- The Marshall Centre for Infectious Diseases Research and Training, University of Western Australia, Perth 6009, Australia
| | - Barry J Marshall
- The Marshall Centre for Infectious Diseases Research and Training, University of Western Australia, Perth 6009, Australia
| | - Xuehong Li
- Department of Clinical Laboratory, Kuichong People's Hospital, Shenzhen 518119, China
| | - Eng Guan Chua
- The Marshall Centre for Infectious Diseases Research and Training, University of Western Australia, Perth 6009, Australia
| |
Collapse
|
16
|
Rice AM, Long Y, King SB. Nitroaromatic Antibiotics as Nitrogen Oxide Sources. Biomolecules 2021; 11:267. [PMID: 33673069 PMCID: PMC7918234 DOI: 10.3390/biom11020267] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/09/2021] [Accepted: 02/10/2021] [Indexed: 12/21/2022] Open
Abstract
Nitroaromatic antibiotics show activity against anaerobic bacteria and parasites, finding use in the treatment of Heliobacter pylori infections, tuberculosis, trichomoniasis, human African trypanosomiasis, Chagas disease and leishmaniasis. Despite this activity and a clear need for the development of new treatments for these conditions, the associated toxicity and lack of clear mechanisms of action have limited their therapeutic development. Nitroaromatic antibiotics require reductive bioactivation for activity and this reductive metabolism can convert the nitro group to nitric oxide (NO) or a related reactive nitrogen species (RNS). As nitric oxide plays important roles in the defensive immune response to bacterial infection through both signaling and redox-mediated pathways, defining controlled NO generation pathways from these antibiotics would allow the design of new therapeutics. This review focuses on the release of nitrogen oxide species from various nitroaromatic antibiotics to portend the increased ability for these compounds to positively impact infectious disease treatment.
Collapse
Affiliation(s)
| | | | - S. Bruce King
- Department of Chemistry and Biochemistry, Wake Forest University, Winston-Salem, NC 27101, USA; (A.M.R.); (Y.L.)
| |
Collapse
|
17
|
Windham IH, Merrell DS. Analysis of fitness costs associated with metronidazole and amoxicillin resistance in Helicobacter pylori. Helicobacter 2020; 25:e12724. [PMID: 32677105 DOI: 10.1111/hel.12724] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 06/17/2020] [Accepted: 06/21/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND Increasing rates of antibiotic resistance are a major concern for all pathogens, including H. pylori. However, increased resistance often coincides with a decrease in relative fitness of the pathogen in the absence of the antibiotic, raising the possibility that increased resistance can be mitigated for some antibiotics by improved antibiotic husbandry. Therefore, a greater understanding of which types of antibiotic resistance create fitness defects in H. pylori may aid rational treatment strategies. MATERIALS AND METHODS While a wealth of H. pylori literature reports mutations that correlate with increased resistance, few studies demonstrate causation for these same mutations. Herein, we examined fitness costs associated with metronidazole and amoxicillin resistance. Isogenic strains bearing literature reported point mutations in the rdxA and pbp1 genes were engineered and tested in in vitro competition assays to assess relative fitness. RESULTS None of the metronidazole resistance mutations resulted in a fitness cost under the tested conditions. In contrast, amoxicillin-resistant mutant strains demonstrated a defect in competition by 24 hours. This change in fitness was further enhanced by moderate osmotic stress. However, under extreme osmotic stress, the amoxicillin-resistant N562Y PBP1 mutant strain showed enhanced fitness, suggesting that there are some pbp1 mutations that can give a conditional fitness advantage. CONCLUSIONS Our results demonstrate the role of specific point mutations in rdxA and pbp1 in antibiotic resistance and suggest that amoxicillin-resistant strains of H. pylori show environmentally dictated changes in fitness. These later finding may be responsible for the relatively low rates of amoxicillin resistance seen in the United States.
Collapse
Affiliation(s)
- Ian H Windham
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - D Scott Merrell
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| |
Collapse
|
18
|
Biernat MM, Bińkowska A, Łaczmański Ł, Biernat P, Krzyżek P, Gościniak G. Phenotypic and Genotypic Analysis of Resistant Helicobacter pylori Strains Isolated from Children with Gastrointestinal Diseases. Diagnostics (Basel) 2020; 10:E759. [PMID: 32992661 PMCID: PMC7601641 DOI: 10.3390/diagnostics10100759] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 09/23/2020] [Accepted: 09/26/2020] [Indexed: 12/16/2022] Open
Abstract
Antibiotic resistance of Helicobacter pylori is currently a global issue. The aim of this study was to analyze actual antibiotic resistance rates of H. pylori strains isolated from children with primary infections and to compare the incidence of mutations that determine resistance to clarithromycin (CH) and metronidazole (MET) in children with different clinical diagnoses. A total of 91 H. pylori strains were isolated from 108 children with primary infections. Drug susceptibility testing of the strains was performed using E-test method. Classical sequencing of DNA fragments was used to detect point mutations for CH and MET resistance. Resistance to CH was detected in 31% of isolated strains (28/91), while resistance to MET and CH was detected in 35% (32/91) of strains. A2143G was the most frequently detected mutation and was dominant among strains isolated from children with peptic ulcer disease (80%). Mutations in the rdxA gene were found significantly more frequently among MET-resistant strains than MET-sensitive strains (p = 0.03, Chi2 = 4.3909). In children, a higher frequency of H. pylori multiresistant strains was observed compared with the previous study in the same area. Differences were found in the occurrence of point mutations among H. pylori strains resistant to CH isolated from children with different clinical diagnoses.
Collapse
Affiliation(s)
- Monika Maria Biernat
- Department and Clinic of Haematology, Blood Neoplasms, and Bone Marrow Transplantation, Wroclaw Medical University, 50-367 Wroclaw, Poland;
| | - Aldona Bińkowska
- 2nd Military Field Hospital of the Polish Armed Forces, 50-984 Wroclaw, Poland;
| | - Łukasz Łaczmański
- Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wroclaw, Poland;
| | - Paweł Biernat
- Department of Drugs Form Technology, Wroclaw Medical University, 50-556 Wroclaw, Poland;
| | - Paweł Krzyżek
- Department of Microbiology, Wroclaw Medical University, 50-368 Wroclaw, Poland;
| | - Grażyna Gościniak
- Department of Microbiology, Wroclaw Medical University, 50-368 Wroclaw, Poland;
| |
Collapse
|
19
|
Tshibangu-Kabamba E, Ngoma-Kisoko PDJ, Tuan VP, Matsumoto T, Akada J, Kido Y, Tshimpi-Wola A, Tshiamala-Kashala P, Ahuka-Mundeke S, Mumba Ngoy D, Disashi-Tumba G, Yamaoka Y. Next-Generation Sequencing of the Whole Bacterial Genome for Tracking Molecular Insight into the Broad-Spectrum Antimicrobial Resistance of Helicobacter pylori Clinical Isolates from the Democratic Republic of Congo. Microorganisms 2020; 8:E887. [PMID: 32545318 PMCID: PMC7356661 DOI: 10.3390/microorganisms8060887] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/03/2020] [Accepted: 06/04/2020] [Indexed: 12/24/2022] Open
Abstract
Antimicrobial susceptibility testing (AST) is increasingly needed to guide the Helicobacter pylori (H. pylori) treatment but remains laborious and unavailable in most African countries. To assess the clinical relevance of bacterial whole genome sequencing (WGS)-based methods for predicting drug susceptibility in African H. pylori, 102 strains isolated from the Democratic Republic of Congo were subjected to the phenotypic AST and next-generation sequencing (NGS). WGS was used to screen for the occurrence of genotypes encoding antimicrobial resistance (AMR). We noted the broad-spectrum AMR of H. pylori (rates from 23.5 to 90.0%). A WGS-based method validated for variant discovery in AMR-related genes (discovery rates of 100%) helped in identifying mutations of key genes statistically related to the phenotypic AMR. These included mutations often reported in Western and Asian populations and, interestingly, several putative AMR-related new genotypes in the pbp1A (e.g., T558S, F366L), gyrA (e.g., A92T, A129T), gyrB (e.g., R579C), and rdxA (e.g., R131_K166del) genes. WGS showed high performance for predicting AST phenotypes, especially for amoxicillin, clarithromycin, and levofloxacin (Youden's index and Cohen's Kappa > 0.80). Therefore, WGS is an accurate alternative to the phenotypic AST that provides substantial decision-making information for public health policy makers and clinicians in Africa, while providing insight into AMR mechanisms for researchers.
Collapse
Affiliation(s)
- Evariste Tshibangu-Kabamba
- Department of Environmental and Preventive Medicine, Faculty of Medicine, Oita University, Oita 879-5593, Japan; (E.T.-K.); (V.P.T.); (T.M.); (J.A.); (Y.K.)
- Department of Internal Medicine, Faculty of Medicine, University of Mbujimayi, Mbujimayi, DR Congo;
| | - Patrick de Jesus Ngoma-Kisoko
- Department of Internal Medicine, Gastroenterology and Hepatology Section, Faculty of Medicine, University of Kinshasa, Kinshasa, DR Congo; (P.d.J.N.-K.); (A.T.-W.)
- Department of Gastroenterology and Hepatology, Cinquantenaire’s Hospital, Kinshasa, DR Congo
- Department of Internal Medicine, Gastroenterology and Hepatology Section, General Referential Hospital of Bukavu, DR Congo
| | - Vo Phuoc Tuan
- Department of Environmental and Preventive Medicine, Faculty of Medicine, Oita University, Oita 879-5593, Japan; (E.T.-K.); (V.P.T.); (T.M.); (J.A.); (Y.K.)
- Department of Endoscopy, Cho Ray Hospital, Ho Chi Minh 70000, Vietnam
| | - Takashi Matsumoto
- Department of Environmental and Preventive Medicine, Faculty of Medicine, Oita University, Oita 879-5593, Japan; (E.T.-K.); (V.P.T.); (T.M.); (J.A.); (Y.K.)
| | - Junko Akada
- Department of Environmental and Preventive Medicine, Faculty of Medicine, Oita University, Oita 879-5593, Japan; (E.T.-K.); (V.P.T.); (T.M.); (J.A.); (Y.K.)
| | - Yasutoshi Kido
- Department of Environmental and Preventive Medicine, Faculty of Medicine, Oita University, Oita 879-5593, Japan; (E.T.-K.); (V.P.T.); (T.M.); (J.A.); (Y.K.)
- Department of Parasitology, Osaka City University, Osaka 545-8585, Japan
| | - Antoine Tshimpi-Wola
- Department of Internal Medicine, Gastroenterology and Hepatology Section, Faculty of Medicine, University of Kinshasa, Kinshasa, DR Congo; (P.d.J.N.-K.); (A.T.-W.)
- Department of Internal Medicine, Gastroenterology and Hepatology Section, Marie-Yvettes Clinics, Kinshasa, DR Congo
| | - Pascal Tshiamala-Kashala
- Department of Internal Medicine, Gastroenterology and Hepatology Section, Astryd Clinics, Kinshasa, DR Congo;
| | - Steve Ahuka-Mundeke
- Department of Virology, National Institute of Biomedical Research, Kinshasa, DR Congo;
| | - Dieudonné Mumba Ngoy
- Department of Parasitology, National Institute of Biomedical Research, Kinshasa, DR Congo;
- Department of Tropical Medicine, School of Medicine, University of Kinshasa, Kinshasa, DR Congo
| | - Ghislain Disashi-Tumba
- Department of Internal Medicine, Faculty of Medicine, University of Mbujimayi, Mbujimayi, DR Congo;
| | - Yoshio Yamaoka
- Department of Environmental and Preventive Medicine, Faculty of Medicine, Oita University, Oita 879-5593, Japan; (E.T.-K.); (V.P.T.); (T.M.); (J.A.); (Y.K.)
- Department of Medicine, Gastroenterology and Hepatology Section, Baylor College of Medicine, Houston, TX 77030, USA
| |
Collapse
|
20
|
Salillas S, Alías M, Michel V, Mahía A, Lucía A, Rodrigues L, Bueno J, Galano-Frutos JJ, De Reuse H, Velázquez-Campoy A, Carrodeguas JA, Sostres C, Castillo J, Aínsa JA, Díaz-de-Villegas MD, Lanas Á, Touati E, Sancho J. Design, Synthesis, and Efficacy Testing of Nitroethylene- and 7-Nitrobenzoxadiazol-Based Flavodoxin Inhibitors against Helicobacter pylori Drug-Resistant Clinical Strains and in Helicobacter pylori-Infected Mice. J Med Chem 2019; 62:6102-6115. [DOI: 10.1021/acs.jmedchem.9b00355] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Sandra Salillas
- Biocomputation and Complex Systems Physics Institute (BIFI)-Joint Units: BIFI-IQFR (CSIC) and GBsC-CSIC, University of Zaragoza, Zaragoza 50018, Spain
- Aragon Health Research Institute (IIS Aragón), Zaragoza 50009, Spain
| | - Miriam Alías
- Biocomputation and Complex Systems Physics Institute (BIFI)-Joint Units: BIFI-IQFR (CSIC) and GBsC-CSIC, University of Zaragoza, Zaragoza 50018, Spain
| | - Valérie Michel
- Helicobacter Pathogenesis Unit, Department of Microbiology, CNRS ERL6002, Institut Pasteur, 25-28 Rue du Dr. Roux, Paris 75724, France
| | - Alejandro Mahía
- Biocomputation and Complex Systems Physics Institute (BIFI)-Joint Units: BIFI-IQFR (CSIC) and GBsC-CSIC, University of Zaragoza, Zaragoza 50018, Spain
- Aragon Health Research Institute (IIS Aragón), Zaragoza 50009, Spain
| | - Ainhoa Lucía
- Aragon Health Research Institute (IIS Aragón), Zaragoza 50009, Spain
| | - Liliana Rodrigues
- Aragon Health Research Institute (IIS Aragón), Zaragoza 50009, Spain
| | | | - Juan José Galano-Frutos
- Biocomputation and Complex Systems Physics Institute (BIFI)-Joint Units: BIFI-IQFR (CSIC) and GBsC-CSIC, University of Zaragoza, Zaragoza 50018, Spain
- Aragon Health Research Institute (IIS Aragón), Zaragoza 50009, Spain
| | - Hilde De Reuse
- Helicobacter Pathogenesis Unit, Department of Microbiology, CNRS ERL6002, Institut Pasteur, 25-28 Rue du Dr. Roux, Paris 75724, France
| | - Adrián Velázquez-Campoy
- Biocomputation and Complex Systems Physics Institute (BIFI)-Joint Units: BIFI-IQFR (CSIC) and GBsC-CSIC, University of Zaragoza, Zaragoza 50018, Spain
- Aragon Health Research Institute (IIS Aragón), Zaragoza 50009, Spain
- Fundación ARAID, Gobierno de Aragón, Zaragoza 50009, Spain
| | - José Alberto Carrodeguas
- Biocomputation and Complex Systems Physics Institute (BIFI)-Joint Units: BIFI-IQFR (CSIC) and GBsC-CSIC, University of Zaragoza, Zaragoza 50018, Spain
- Aragon Health Research Institute (IIS Aragón), Zaragoza 50009, Spain
| | - Carlos Sostres
- Aragon Health Research Institute (IIS Aragón), Zaragoza 50009, Spain
| | | | - José Antonio Aínsa
- Biocomputation and Complex Systems Physics Institute (BIFI)-Joint Units: BIFI-IQFR (CSIC) and GBsC-CSIC, University of Zaragoza, Zaragoza 50018, Spain
- Aragon Health Research Institute (IIS Aragón), Zaragoza 50009, Spain
| | | | - Ángel Lanas
- Aragon Health Research Institute (IIS Aragón), Zaragoza 50009, Spain
| | - Eliette Touati
- Helicobacter Pathogenesis Unit, Department of Microbiology, CNRS ERL6002, Institut Pasteur, 25-28 Rue du Dr. Roux, Paris 75724, France
| | - Javier Sancho
- Biocomputation and Complex Systems Physics Institute (BIFI)-Joint Units: BIFI-IQFR (CSIC) and GBsC-CSIC, University of Zaragoza, Zaragoza 50018, Spain
- Aragon Health Research Institute (IIS Aragón), Zaragoza 50009, Spain
| |
Collapse
|
21
|
Shetty V, Lamichhane B, Tay CY, Pai GC, Lingadakai R, Balaraju G, Shetty S, Ballal M, Chua EG. High primary resistance to metronidazole and levofloxacin, and a moderate resistance to clarithromycin in Helicobacter pylori isolated from Karnataka patients. Gut Pathog 2019; 11:21. [PMID: 31110563 PMCID: PMC6513510 DOI: 10.1186/s13099-019-0305-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 05/02/2019] [Indexed: 12/16/2022] Open
Abstract
Background Due to increased prevalence of H. pylori antimicrobial resistance worldwide and more importantly the resistance patterns vary between different geographical regions, it is important to survey local H. pylori antibiotic resistance profile to provide physicians with more informed drug choices to better treat H. pylori infection. To our knowledge, this is the first study to examine the prevalence of antimicrobial resistance of H. pylori in Karnataka state of South India. Results A total of 113 H. pylori strains were isolated from gastric biopsies and tested: 81.4% were resistant to metronidazole, 54.9% were resistant to levofloxacin, 20.4% were resistant to clarithromycin, 5.3% were resistant to tetracycline and 7.1% were resistant to amoxicillin. Multidrug resistance was detected in 59.3% of total isolated strains, among which 86.6% were resistant to at least both metronidazole and levofloxacin. In this study, 38 out of 113 H. pylori strains had been whole-genome sequenced. Based on the draft genomes, RdxA and/or FrxA inactivation mutations were found to present in 75% of metronidazole-resistant strains. Clarithromycin-resistant strains had mainly A2143G and G2224A mutations in the 23 rRNA gene. While 87.1% levofloxacin-resistant strains had amino acid substitution mutations occurring predominantly at N87 and D91 in GyrA, novel mutations in the same protein including an insertion of five amino acid residues (QDNSV), immediately after the start codon, and a substitution mutation at R295 were identified. Conclusion High primary resistance to metronidazole and levofloxacin, and a modest occurrence of clarithromycin resistance were revealed in H. pylori strains isolated from Karnataka patients. Therefore metronidazole-, levofloxacin- and clarithromycin-based triple therapies are not suitable as first-line treatment in Karnataka. Both amoxicillin and tetracycline can still be used to eradicate H. pylori infection in this region. We also revealed novel mutations in GyrA protein that possibly contribute to H. pylori resistance in levofloxacin, which merit further investigations.
Collapse
Affiliation(s)
- Vignesh Shetty
- 1Enteric Diseases Division, Central Research Lab, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, India
| | - Binit Lamichhane
- 2Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, Crawley, WA Australia
| | - Chin Yen Tay
- 2Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, Crawley, WA Australia.,Shenzhen Dapeng New District Kuichong People Hospital, Shenzhen City, Guangdong Province China
| | - Ganesh C Pai
- 4Department of Gastroenterology & Hepatology, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, Karnataka India
| | - Ramachandra Lingadakai
- 5Department of Surgery, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, Karnataka India
| | - Girisha Balaraju
- 4Department of Gastroenterology & Hepatology, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, Karnataka India
| | - Shiran Shetty
- 4Department of Gastroenterology & Hepatology, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, Karnataka India
| | - Mamatha Ballal
- 1Enteric Diseases Division, Central Research Lab, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, India
| | - Eng Guan Chua
- 2Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, Crawley, WA Australia
| |
Collapse
|
22
|
Saghaug CS, Klotz C, Kallio JP, Brattbakk HR, Stokowy T, Aebischer T, Kursula I, Langeland N, Hanevik K. Genetic variation in metronidazole metabolism and oxidative stress pathways in clinical Giardia lamblia assemblage A and B isolates. Infect Drug Resist 2019; 12:1221-1235. [PMID: 31190910 PMCID: PMC6519707 DOI: 10.2147/idr.s177997] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 01/16/2019] [Indexed: 12/12/2022] Open
Abstract
Purpose: Treatment-refractory Giardia cases have increased rapidly within the last decade. No markers of resistance nor a standardized susceptibility test have been established yet, but several enzymes and their pathways have been associated with metronidazole (MTZ) resistant Giardia. Very limited data are available regarding genetic variation in these pathways. We aimed to investigate genetic variation in metabolic pathway genes proposed to be involved in MTZ resistance in recently acquired, cultured clinical isolates. Methods: Whole genome sequencing of 12 assemblage A2 and 8 assemblage B isolates was done, to decipher genomic variation in Giardia. Twenty-nine genes were identified in a literature search and investigated for their single nucleotide variants (SNVs) in the coding/non-coding regions of the genes, either as amino acid changing (non-synonymous SNVs) or non-changing SNVs (synonymous). Results: In Giardia assemblage B, several genes involved in MTZ activation or oxidative stress management were found to have higher numbers of non-synonymous SNVs (thioredoxin peroxidase, nitroreductase 1, ferredoxin 2, NADH oxidase, nitroreductase 2, alcohol dehydrogenase, ferredoxin 4 and ferredoxin 1) than the average variation. For Giardia assemblage A2, the highest genetic variability was found in the ferredoxin 2, ferredoxin 6 and in nicotinamide adenine dinucleotide phosphate (NADPH) oxidoreductase putative genes. SNVs found in the ferredoxins and nitroreductases were analyzed further by alignment and homology modeling. SNVs close to the iron-sulfur cluster binding sites in nitroreductase-1 and 2 and ferredoxin 2 and 4 could potentially affect protein function. Flavohemoprotein seems to be a variable-copy gene, due to higher, but variable coverage compared to other genes investigated. Conclusion: In clinical Giardia isolates, genetic variability is common in important genes in the MTZ metabolizing pathway and in the management of oxidative and nitrosative stress and includes high numbers of non-synonymous SNVs. Some of the identified amino acid changes could potentially affect the respective proteins important in the MTZ metabolism.
Collapse
Affiliation(s)
- Christina S Saghaug
- Department of Clinical Science, University of Bergen, Bergen, Hordaland, Norway.,Norwegian National Advisory Unit on Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, Bergen, Hordaland, Norway
| | - Christian Klotz
- Department of Infectious Diseases, Unit 16 Mycotic and Parasitic Agents and Mycobacteria, Robert Koch-Institute, Berlin, Germany
| | - Juha P Kallio
- Department of Biomedicine, University of Bergen, Bergen, Hordaland, Norway
| | - Hans-Richard Brattbakk
- Department of Clinical Science, University of Bergen, Bergen, Hordaland, Norway.,Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Hordaland, Norway
| | - Tomasz Stokowy
- Department of Clinical Science, University of Bergen, Bergen, Hordaland, Norway.,Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Hordaland, Norway
| | - Toni Aebischer
- Department of Infectious Diseases, Unit 16 Mycotic and Parasitic Agents and Mycobacteria, Robert Koch-Institute, Berlin, Germany
| | - Inari Kursula
- Department of Biomedicine, University of Bergen, Bergen, Hordaland, Norway.,Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Nina Langeland
- Department of Clinical Science, University of Bergen, Bergen, Hordaland, Norway.,Norwegian National Advisory Unit on Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, Bergen, Hordaland, Norway.,Department of Medicine, Haraldsplass Deaconess Hospital, Bergen, Hordaland, Norway
| | - Kurt Hanevik
- Department of Clinical Science, University of Bergen, Bergen, Hordaland, Norway.,Norwegian National Advisory Unit on Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, Bergen, Hordaland, Norway
| |
Collapse
|
23
|
Lee JW, Kim N, Nam RH, Lee SM, Soo In C, Kim JM, Lee DH. Risk factors of rescue bismuth quadruple therapy failure for Helicobacter pylori eradication. J Gastroenterol Hepatol 2019; 34:666-672. [PMID: 30726563 DOI: 10.1111/jgh.14625] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 01/13/2019] [Accepted: 01/31/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND AND AIM Failure of bismuth quadruple therapy for Helicobacter pylori eradication is frequently observed. To increase the eradication rate, comprehensive analyses need to be performed regarding risk factors of bismuth quadruple therapy failure based on complete standard culture and antimicrobial susceptibility testing results. METHODS Patients with history of failed first therapy who had H. pylori colonies isolated from culture and successful minimum inhibitory concentration (MIC) test were enrolled. Esomeprazole, bismuth, metronidazole, and tetracycline (quadruple) therapies for 7 or 14 days were given. Eradication rate, treatment compliance, adverse events, and risk factors for the failure of bismuth quadruple therapy were analyzed. RESULTS A total 54 patients were enrolled. Overall eradication rate in the present study was 88.8%. The eradication rate for cases with metronidazole resistance such as MIC 8-16 μg/mL or 16-32 μg/mL was 92.8% (13/14). For cases with high level metronidazole resistance (MIC > 32 μg/mL), the eradication rate was only 60% (6/10). Multivariate analysis regarding compliance, treatment duration, age > 60, three kinds of metronidazole MICs, tetracycline MIC > 4 μg/mL, adverse events and any other parameters, "metronidazole resistance, high level (MIC > 32 μg/mL)" was the only independent risk factor for eradication failure (P = 0.007). CONCLUSION For cases with metronidazole resistance at MIC > 32 μg/mL, rescue therapy other than bismuth-containing quadruple therapy is needed.
Collapse
Affiliation(s)
- Jung Won Lee
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.,Department of Internal Medicine, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Korea
| | - Nayoung Kim
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.,Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine
| | - Ryoung Hee Nam
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Sun Min Lee
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Choi Soo In
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Jung Mogg Kim
- Department of Microbiology, Hanyang University School of Medicine, Seoul, South Korea
| | - Dong Ho Lee
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.,Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine
| |
Collapse
|
24
|
Marques B, Donato MM, Cardoso O, Luxo C, Martinho A, Almeida N. Study of rdxA and frxA genes mutations in metronidazole-resistant and -susceptible Helicobacter pylori clinical isolates from the central region of Portugal. J Glob Antimicrob Resist 2019; 17:300-304. [PMID: 30658199 DOI: 10.1016/j.jgar.2019.01.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 11/28/2018] [Accepted: 01/06/2019] [Indexed: 12/31/2022] Open
Abstract
OBJECTIVES Helicobacter pylori is one of the most prevalent global pathogens colonising an estimated 50% of the world's population. Although metronidazole (MTZ) is an important antibiotic playing a relevant role in various H. pylori eradication therapies, its frequent consumption results in an increased frequency of resistance with a consequent negative impact on treatment efficacy. Mutations on genes encoding NADPH nitroreductases, commonly known as rdxA gene (oxygen-insensitive) and frxA gene (flavinreductase) have been associated to H. pylori resistance to metrodinazole. The aim of this study was to evaluate the mutation profile of rdxA and frxA genes in a population of 38 H. pylori isolates with phenotypic patterns of susceptibility and resistance to this antibiotic. METHODS Touchdown PCR with the purpose of amplifying rdxA and frxA genes in one PCR was used. Sequence data were made by pair-wise sequence alignment and were examined in terms of codons, and comparison was achieved regarding amino acids. RESULTS Although repeated mutations occurred in positions 118, 131, 172 and 183 of rdxA and in positions 72, 73, 110, 126 and 193 of frxA, it must be highlighted that the mutations are widespread along these two genes in this population. Furthermore, six MTZ-resistant isolates did not present any mutation in the frxA gene. CONCLUSIONS This work appears to confirm that mutations in rdxA and frxA alone are unable to explain MTZ resistance in H. pylori isolates and therefore additional mechanisms may exist and should be investigated.
Collapse
Affiliation(s)
- Bruno Marques
- Centro do Sangue e da Transplantação de Coimbra, Instituto Português do Sangue e da Transplantação, IP, Coimbra, Portugal
| | - Maria Manuel Donato
- CIMAGO, Faculty of Medicine, University of Coimbra, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal.
| | - Olga Cardoso
- Laboratory of Microbiology, Faculty of Pharmacy and CIEPQPF, Department of Chemical Engineering, Faculty of Science and Technology, University of Coimbra, Coimbra, Portugal
| | - Cristina Luxo
- Laboratory of Microbiology, Faculty of Pharmacy and CIEPQPF, Department of Chemical Engineering, Faculty of Science and Technology, University of Coimbra, Coimbra, Portugal
| | - António Martinho
- Centro do Sangue e da Transplantação de Coimbra, Instituto Português do Sangue e da Transplantação, IP, Coimbra, Portugal
| | - Nuno Almeida
- Faculty of Medicine, University of Coimbra, and Gastroenterology Department, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
| |
Collapse
|
25
|
Chua EG, Debowski AW, Webberley KM, Peters F, Lamichhane B, Loke MF, Vadivelu J, Tay CY, Marshall BJ, Wise MJ. Analysis of core protein clusters identifies candidate variable sites conferring metronidazole resistance in Helicobacter pylori. Gastroenterol Rep (Oxf) 2019; 7:42-49. [PMID: 30792865 PMCID: PMC6375344 DOI: 10.1093/gastro/goy048] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 09/19/2018] [Accepted: 09/26/2018] [Indexed: 01/10/2023] Open
Abstract
Background Metronidazole is one of the first-line drugs of choice in the standard triple therapy used to eradicate Helicobacter pylori infection. Hence, the global emergence of metronidazole resistance in Hp poses a major challenge to health professionals. Inactivation of RdxA is known to be a major mechanism of conferring metronidazole resistance in H. pylori. However, metronidazole resistance can also arise in H. pylori strains expressing functional RdxA protein, suggesting that there are other mechanisms that may confer resistance to this drug. Methods We performed whole-genome sequencing on 121 H. pylori clinical strains, among which 73 were metronidazole-resistant. Sequence-alignment analysis of core protein clusters derived from clinical strains containing full-length RdxA was performed. Variable sites in each alignment were statistically compared between the resistant and susceptible groups to determine candidate genes along with their respective amino-acid changes that may account for the development of metronidazole resistance in H. pylori. Results Resistance due to RdxA truncation was identified in 34% of metronidazole-resistant strains. Analysis of core protein clusters derived from the remaining 48 metronidazole-resistant strains and 48 metronidazole-susceptible identified four variable sites significantly associated with metronidazole resistance. These sites included R16H/C in RdxA, D85N in the inner-membrane protein RclC (HP0565), V265I in a biotin carboxylase protein (HP0370) and A51V/T in a putative threonylcarbamoyl–AMP synthase (HP0918). Conclusions Our approach identified new potential mechanisms for metronidazole resistance in H. pylori that merit further investigation.
Collapse
Affiliation(s)
- Eng-Guan Chua
- The Marshall Centre for Infectious Diseases Research and Training, University of Western Australia, Perth, Western Australia, Australia
| | - Aleksandra W Debowski
- The Marshall Centre for Infectious Diseases Research and Training, University of Western Australia, Perth, Western Australia, Australia.,School of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Western Australia, Perth, Western Australia, Australia
| | - K Mary Webberley
- The Marshall Centre for Infectious Diseases Research and Training, University of Western Australia, Perth, Western Australia, Australia
| | - Fanny Peters
- The Marshall Centre for Infectious Diseases Research and Training, University of Western Australia, Perth, Western Australia, Australia
| | - Binit Lamichhane
- The Marshall Centre for Infectious Diseases Research and Training, University of Western Australia, Perth, Western Australia, Australia
| | - Mun-Fai Loke
- Department of Medical Microbiology, University of Malaya, Kuala Lumpur, Wilayah Persekutuan, Malaysia
| | - Jamuna Vadivelu
- Department of Medical Microbiology, University of Malaya, Kuala Lumpur, Wilayah Persekutuan, Malaysia
| | - Chin-Yen Tay
- The Marshall Centre for Infectious Diseases Research and Training, University of Western Australia, Perth, Western Australia, Australia.,Shenzhen Dapeng New District Kuichong People Hospital, Shenzhen, Guangdong, China
| | - Barry J Marshall
- The Marshall Centre for Infectious Diseases Research and Training, University of Western Australia, Perth, Western Australia, Australia.,Shenzhen Dapeng New District Kuichong People Hospital, Shenzhen, Guangdong, China.,UM Marshall Centre, University of Malaya, Kuala Lumpur, Wilayah Persekutuan, Malaysia
| | - Michael J Wise
- The Marshall Centre for Infectious Diseases Research and Training, University of Western Australia, Perth, Western Australia, Australia.,School of Computer Science and Software Engineering, University of Western Australia, Perth, Western Australia, Australia
| |
Collapse
|
26
|
Yang J, Bai J, Qu M, Xie B, Yang Q. Biochemical characteristics of a nitroreductase with diverse substrate specificity from Streptomyces mirabilis DUT001. Biotechnol Appl Biochem 2018; 66:33-42. [PMID: 30231196 DOI: 10.1002/bab.1692] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 09/11/2018] [Indexed: 11/09/2022]
Abstract
A nitroreductase-encoded gene from an efficient nitro-reducing bacterium Streptomyces mirabilis DUT001, named snr, was cloned and heterogeneously expressed in Escherichia coli. The purified Streptomyces nitroreductase SNR was a homodimer with an apparent subunit molecular weight of 24 kDa and preferred NADH to NADPH as a cofactor. By enzyme incubation and isothermal calorimetry experiments, flavin mononucleotide (FMN) was found to be the preferred flavin cofactor; the binding process was exothermic and primarily enthalpy driven. The enzyme can reduce multiple nitro compounds and flavins, including antibacterial drug nitrofurazone, priority pollutants 2,4-dinitrotoluene and 2,4,6-trinitrotoluene, as well as key chemical intermediates 3-nitrophthalimide, 4-nitrophthalimide, and 4-nitro-1,8-naphthalic anhydride. Among the substrates tested, the highest activity of kcat(app) /Km(app) (0.234 μM-1 Sec-1 ) was observed for the reduction of FMN. Multiple sequence alignment revealed that the high FMN reduction activity of SNR may be due to the absence of a helix, constituting the entrance to the substrate pocket in other nitroreductases.
Collapse
Affiliation(s)
- Jun Yang
- State Key Laboratory of Fine Chemical Engineering and School of Life Science and Biotechnology, Dalian University of Technology, Dalian, People's Republic of China
| | - Jing Bai
- College of Bioscience and Bioengineering, Hebei University of Science & Technology, Hebei, People's Republic of China
| | - Mingbo Qu
- State Key Laboratory of Fine Chemical Engineering and School of Life Science and Biotechnology, Dalian University of Technology, Dalian, People's Republic of China
| | - Bo Xie
- State Key Laboratory of Fine Chemical Engineering and School of Life Science and Biotechnology, Dalian University of Technology, Dalian, People's Republic of China
| | - Qing Yang
- State Key Laboratory of Fine Chemical Engineering and School of Life Science and Biotechnology, Dalian University of Technology, Dalian, People's Republic of China
| |
Collapse
|
27
|
Gonzalez-Hormazabal P, Musleh M, Escandar S, Valladares H, Lanzarini E, Castro VG, Jara L, Berger Z. Prevalence of clarithromycin resistance in Helicobacter pylori in Santiago, Chile, estimated by real-time PCR directly from gastric mucosa. BMC Gastroenterol 2018; 18:91. [PMID: 29925321 PMCID: PMC6011593 DOI: 10.1186/s12876-018-0820-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 06/07/2018] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Current available treatments for Helicobacter pylori eradication are chosen according to local clarithromycin and metronidazole resistance prevalence. The aim of this study was to estimate, by means of molecular methods, both clarithromycin and metronidazole resistance in gastric mucosa from patients infected with H.pylori. METHODS A total of 191 DNA samples were analyzed. DNA was purified from gastric mucosa obtained from patients who underwent an upper gastrointestinal endoscopy at an university hospital from Santiago, Chile, between 2011 and 2014. H.pylori was detected by real-time PCR. A 5'exonuclease assay was developed to detect A2142G and A2143G mutations among H.pylori-positive samples. rdxA gene was sequenced in samples harboring A2142G and A2143G mutations in order to detect mutations that potentially confer dual clarithromycin and metronidazole resistance. RESULTS Ninety-three (93) out of 191 DNA samples obtained from gastric mucosa were H.pylori-positive (48.7%). Clarithromycin-resistance was detected in 29 samples (31.2% [95%CI 22.0-41.6%]). The sequencing of rdxA gene revealed that two samples harbored truncating mutations in rdxA, one sample had an in-frame deletion, and 11 had amino acid changes that likely cause metronidazole resistance. CONCLUSIONS We estimated a prevalence of clarithomycin-resistance of 31.8% in Santiago, Chile. Three of them harbor inactivating mutations in rdxA and 11 had missense mutations likely conferring metronidazole resistance. Our results require further confirmation. Nevertheless, they are significant as an initial approximation in re-evaluating the guidelines for H.pylori eradication currently used in Chile.
Collapse
Affiliation(s)
- Patricio Gonzalez-Hormazabal
- Human Genetics Program, Institute of Biomedical Sciences, School of Medicine, University of Chile, Av. Independencia 1027, 8380453, Santiago, CL, Chile.
| | - Maher Musleh
- Department of Gastroenterology, University of Chile Clinical Hospital, Santiago, Chile.,Department of Surgery, University of Chile Clinical Hospital, Santiago, Chile
| | - Susana Escandar
- Department of Gastroenterology, University of Chile Clinical Hospital, Santiago, Chile
| | - Hector Valladares
- Department of Gastroenterology, University of Chile Clinical Hospital, Santiago, Chile.,Department of Surgery, University of Chile Clinical Hospital, Santiago, Chile
| | - Enrique Lanzarini
- Department of Gastroenterology, University of Chile Clinical Hospital, Santiago, Chile.,Department of Surgery, University of Chile Clinical Hospital, Santiago, Chile
| | - V Gonzalo Castro
- Human Genetics Program, Institute of Biomedical Sciences, School of Medicine, University of Chile, Av. Independencia 1027, 8380453, Santiago, CL, Chile
| | - Lilian Jara
- Human Genetics Program, Institute of Biomedical Sciences, School of Medicine, University of Chile, Av. Independencia 1027, 8380453, Santiago, CL, Chile
| | - Zoltan Berger
- Department of Gastroenterology, University of Chile Clinical Hospital, Santiago, Chile
| |
Collapse
|
28
|
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.
Collapse
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
| |
Collapse
|
29
|
[Frequency of Helicobacter pylori nitroreductase RdxA mutations for metronidazole activation in a population in the Cauca Department, Colombia]. BIOMEDICA 2017; 37:191-199. [PMID: 28527283 DOI: 10.7705/biomedica.v37i2.3007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 07/19/2016] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Resistance to metronidazole is a key factor associated with Helicobacter pylori treatment failure. Even though resistance is mostly associated with RdxA nitroreductase mutations, studies of this H. pylori protein in Popayán (Colombia) are still incipient. OBJECTIVE To evaluate the frequency of mutations in the RdxA nitroreductase in a population of patients with H. pylori-positive gastrointestinal disease. MATERIALS AND METHODS We amplified the DNA of 170 gastric biopsies by PCR to detect mutations in the RdxA nitroreductase. An analysis of DNA sequences translated into amino acid sequences was done and then compared to the reference strain 26695. RESULTS The frequency of RdxA nitroreductase mutations in this study population was 78%. Its most frequent distribution was found in positions D59N (153 samples), R131K (101 samples), R90K (97 samples), A118T (42 samples), I160F (32 samples) and H97T (26 samples), and meaningful stop codons Q50*, D59*; E75*, C159* and I160* in five, one, three, ten and six samples, respectively. The most common virulence genotype was vacAs1/m1 cagA negative (48.6 %). CONCLUSIONS The high frequency of RdxA nitroreductase mutations in H. pylori isolates in Popayán (Colombia) indicates that empirical therapy with metronidazole may not be a valid option for the eradication of H. pylori in patients of the studied population.
Collapse
|
30
|
Ang CW, Jarrad AM, Cooper MA, Blaskovich MAT. Nitroimidazoles: Molecular Fireworks That Combat a Broad Spectrum of Infectious Diseases. J Med Chem 2017; 60:7636-7657. [PMID: 28463485 DOI: 10.1021/acs.jmedchem.7b00143] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Infectious diseases claim millions of lives every year, but with the advent of drug resistance, therapeutic options to treat infections are inadequate. There is now an urgent need to develop new and effective treatments. Nitroimidazoles are a class of antimicrobial drugs that have remarkable broad spectrum activity against parasites, mycobacteria, and anaerobic Gram-positive and Gram-negative bacteria. While nitroimidazoles were discovered in the 1950s, there has been renewed interest in their therapeutic potential, particularly for the treatment of parasitic infections and tuberculosis. In this review, we summarize different classes of nitroimidazoles that have been described in the literature in the past five years, from approved drugs and clinical candidates to examples undergoing preclinical or early stage development. The relatively "nonspecific" mode of action and resistance mechanisms of nitromidazoles are discussed, and contemporary strategies to facilitate nitroimidazole drug development are highlighted.
Collapse
Affiliation(s)
- Chee Wei Ang
- The Institute for Molecular Bioscience, The University of Queensland , St Lucia, Queensland 4072, Australia
| | - Angie M Jarrad
- The Institute for Molecular Bioscience, The University of Queensland , St Lucia, Queensland 4072, Australia
| | - Matthew A Cooper
- The Institute for Molecular Bioscience, The University of Queensland , St Lucia, Queensland 4072, Australia
| | - Mark A T Blaskovich
- The Institute for Molecular Bioscience, The University of Queensland , St Lucia, Queensland 4072, Australia
| |
Collapse
|
31
|
Ansell BRE, Baker L, Emery SJ, McConville MJ, Svärd SG, Gasser RB, Jex AR. Transcriptomics Indicates Active and Passive Metronidazole Resistance Mechanisms in Three Seminal Giardia Lines. Front Microbiol 2017; 8:398. [PMID: 28367140 PMCID: PMC5355454 DOI: 10.3389/fmicb.2017.00398] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 02/27/2017] [Indexed: 12/13/2022] Open
Abstract
Giardia duodenalis is an intestinal parasite that causes 200-300 million episodes of diarrhoea annually. Metronidazole (Mtz) is a front-line anti-giardial, but treatment failure is common and clinical resistance has been demonstrated. Mtz is thought to be activated within the parasite by oxidoreductase enzymes, and to kill by causing oxidative damage. In G. duodenalis, Mtz resistance involves active and passive mechanisms. Relatively low activity of iron-sulfur binding proteins, namely pyruvate:ferredoxin oxidoreductase (PFOR), ferredoxins, and nitroreductase-1, enable resistant cells to passively avoid Mtz activation. Additionally, low expression of oxygen-detoxification enzymes can allow passive (non-enzymatic) Mtz detoxification via futile redox cycling. In contrast, active resistance mechanisms include complete enzymatic detoxification of the pro-drug by nitroreductase-2 and enhanced repair of oxidized biomolecules via thioredoxin-dependent antioxidant enzymes. Molecular resistance mechanisms may be largely founded on reversible transcriptional changes, as some resistant lines revert to drug sensitivity during drug-free culture in vitro, or passage through the life cycle. To comprehensively characterize these changes, we undertook strand-specific RNA sequencing of three laboratory-derived Mtz-resistant lines, 106-2ID10, 713-M3, and WB-M3, and compared transcription relative to their susceptible parents. Common up-regulated genes encoded variant-specific surface proteins (VSPs), a high cysteine membrane protein, calcium and zinc channels, a Mad-2 cell cycle regulator and a putative fatty acid α-oxidase. Down-regulated genes included nitroreductase-1, putative chromate and quinone reductases, and numerous genes that act proximal to PFOR. Transcriptional changes in 106-2ID10 diverged from those in 713-r and WB-r (r ≤ 0.2), which were more similar to each other (r = 0.47). In 106-2ID10, a nonsense mutation in nitroreductase-1 transcripts could enhance passive resistance whereas increased transcription of nitroreductase-2, and a MATE transmembrane pump system, suggest active drug detoxification and efflux, respectively. By contrast, transcriptional changes in 713-M3 and WB-M3 indicated a higher oxidative stress load, attributed to Mtz- and oxygen-derived radicals, respectively. Quantitative comparisons of orthologous gene transcription between Mtz-resistant G. duodenalis and Trichomonas vaginalis, a closely related parasite, revealed changes in transcripts encoding peroxidases, heat shock proteins, and FMN-binding oxidoreductases, as prominent correlates of resistance. This work provides deep insight into Mtz-resistant G. duodenalis, and illuminates resistance-associated features across parasitic species.
Collapse
Affiliation(s)
- Brendan R. E. Ansell
- Faculty of Veterinary and Agricultural Sciences, The University of MelbourneMelbourne, VIC, Australia
| | - Louise Baker
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical ResearchMelbourne, VIC, Australia
| | - Samantha J. Emery
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical ResearchMelbourne, VIC, Australia
| | - Malcolm J. McConville
- Bio21 Molecular Science and Biotechnology Institute, The University of MelbourneMelbourne, VIC, Australia
| | - Staffan G. Svärd
- Department of Cell and Molecular Biology, Uppsala UniversityUppsala, Sweden
| | - Robin B. Gasser
- Faculty of Veterinary and Agricultural Sciences, The University of MelbourneMelbourne, VIC, Australia
| | - Aaron R. Jex
- Faculty of Veterinary and Agricultural Sciences, The University of MelbourneMelbourne, VIC, Australia
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical ResearchMelbourne, VIC, Australia
| |
Collapse
|
32
|
Miftahussurur M, Cruz M, Subsomwong P, Jiménez Abreu JA, Hosking C, Nagashima H, Akada J, Yamaoka Y. Clarithromycin-Based Triple Therapy is Still Useful as an Initial Treatment for Helicobacter pylori Infection in the Dominican Republic. Am J Trop Med Hyg 2017; 96:1050-1059. [PMID: 28193745 DOI: 10.4269/ajtmh.16-0729] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
AbstractHelicobacter pylori antibiotic susceptibility in the Dominican Republic has not been monitored. We assessed H. pylori antibiotic susceptibility in the Dominican Republic, and analyzed H. pylori mutations associated with antibiotic resistance. We recruited 158 dyspeptic patients in Santo Domingo and used agar dilution to test susceptibility to five antibiotics. Polymerase chain reaction-based sequencing was used to assess gyrA, gyrB, rdxA, frxA, and 23S rRNA mutations; next-generation sequencing was used to identify other metronidazole resistance-associated genes. Among 64 H. pylori strains isolated, we identified two (3.1%), one (1.6%), and no strains with clarithromycin, amoxicillin, and tetracycline resistance, respectively. Moreover, high frequency of metronidazole resistance (53/64, 82.8%) was observed, whereas levofloxacin resistance is emerging (23/64, 35.9%). We identified many rdxA and frxA mutations in metronidazole-resistant strains, but no synergistic effect was apparent. We revealed novel mutations in dppA, dppB, fdxA, and fdxB, irrespective of rdxA and frxA mutations. Novel mutations at Ser-14 of trx1 and Arg-221 of dapF were associated with different levels of metronidazole resistance. Most levofloxacin-resistant strains had a substitution at Asn-87 of gyrA, including the strain with the highest levofloxacin resistance, whereas only three substitutions were found at Ser-479 of gyrB with no synergistic effect. Besides the 23S rRNA A2142G mutation, we observed another mutation at T1958G in both clarithromycin-resistant strains. We confirmed high metronidazole and levofloxacin resistance associated with genetic mutations in the Dominican Republic. However, prevalence of clarithromycin resistance was low, suggesting that standard clarithromycin-based triple therapy remains useful as initial treatment of H. pylori infection.
Collapse
Affiliation(s)
- Muhammad Miftahussurur
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu, Japan.,Department of Medicine, Gastroenterology and Hepatology Section, Baylor College of Medicine, Houston, Texas.,Gastroentero-Hepatology Division, Department of Internal Medicine, Faculty of Medicine-Dr. Soetomo Teaching Hospital-Institute of Tropical Disease, Universitas Airlangga, Surabaya, Indonesia
| | - Modesto Cruz
- Institute of Microbiology and Parasitology, Faculty of Science, Autonomous University of Santo Domingo, Santo Domingo, Dominican Republic.,Department of Biomedical Research, National Institute of Medicine and Diagnostic Imaging, Santo Domingo, Dominican Republic
| | - Phawinee Subsomwong
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu, Japan
| | - José A Jiménez Abreu
- Dominican-Japanese Digestive Disease Center, Dr. Luis E. Aybar Health and Hygiene City, Santo Domingo, Dominican Republic
| | - Celso Hosking
- Institute of Microbiology and Parasitology, Faculty of Science, Autonomous University of Santo Domingo, Santo Domingo, Dominican Republic
| | - Hiroyuki Nagashima
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu, Japan
| | - Junko Akada
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu, Japan
| | - Yoshio Yamaoka
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu, Japan.,Department of Medicine, Gastroenterology and Hepatology Section, Baylor College of Medicine, Houston, Texas
| |
Collapse
|
33
|
Wang B, Powell SM, Hessami N, Najar FZ, Thomas LM, Karr EA, West AH, Richter-Addo GB. Crystal structures of two nitroreductases from hypervirulent Clostridium difficile and functionally related interactions with the antibiotic metronidazole. Nitric Oxide 2016; 60:32-39. [PMID: 27623089 PMCID: PMC5079799 DOI: 10.1016/j.niox.2016.09.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 09/05/2016] [Accepted: 09/07/2016] [Indexed: 02/04/2023]
Abstract
Nitroreductases (NRs) are flavin mononucleotide (FMN)-dependent enzymes that catalyze the biotransformation of organic nitro compounds (RNO2; R = alkyl, aryl) to the nitroso RN=O, hydroxylamino RNHOH, or amine RNH2 derivatives. Metronidazole (Mtz) is a nitro-containing antibiotic that is commonly prescribed for lower-gut infections caused by the anaerobic bacterium Clostridium difficile. C. difficile infections rank number one among hospital acquired infections, and can result in diarrhea, severe colitis, or even death. Although NRs have been implicated in Mtz resistance of C. difficile, no NRs have been characterized from the hypervirulent R20291 strain of C. difficile. We report the first expression, purification, and three-dimensional X-ray crystal structures of two NRs from the C. difficile R20291 strain. The X-ray crystal structures of the two NRs were solved to 2.1 Å resolution. Their homodimeric structures exhibit the classic NR α+β fold, with each protomer binding one FMN cofactor near the dimer interface. Functional assays demonstrate that these two NRs metabolize Mtz with associated re-oxidation of the proteins. Importantly, these results represent the first isolation and characterization of NRs from the hypervirulent R20291 strain of relevance to organic RNO2 (e.g., Mtz) metabolism.
Collapse
Affiliation(s)
- Bing Wang
- Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, University of Oklahoma, Norman 73019, United States; Department of Chemistry and Biochemistry, University of Oklahoma, Norman 73019, United States
| | - Samantha M Powell
- Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, University of Oklahoma, Norman 73019, United States; Department of Chemistry and Biochemistry, University of Oklahoma, Norman 73019, United States
| | - Neda Hessami
- Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, University of Oklahoma, Norman 73019, United States; Department of Chemistry and Biochemistry, University of Oklahoma, Norman 73019, United States
| | - Fares Z Najar
- Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, University of Oklahoma, Norman 73019, United States; Department of Chemistry and Biochemistry, University of Oklahoma, Norman 73019, United States
| | - Leonard M Thomas
- Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, University of Oklahoma, Norman 73019, United States; Department of Chemistry and Biochemistry, University of Oklahoma, Norman 73019, United States
| | - Elizabeth A Karr
- Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, University of Oklahoma, Norman 73019, United States; Department of Microbiology and Plant Biology, University of Oklahoma, Norman 73019, United States
| | - Ann H West
- Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, University of Oklahoma, Norman 73019, United States; Department of Chemistry and Biochemistry, University of Oklahoma, Norman 73019, United States
| | - George B Richter-Addo
- Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, University of Oklahoma, Norman 73019, United States; Department of Chemistry and Biochemistry, University of Oklahoma, Norman 73019, United States.
| |
Collapse
|
34
|
Wallace N, Zani A, Abrams E, Sun Y. The Impact of Oxygen on Bacterial Enteric Pathogens. ADVANCES IN APPLIED MICROBIOLOGY 2016; 95:179-204. [PMID: 27261784 DOI: 10.1016/bs.aambs.2016.04.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Bacterial enteric pathogens are responsible for a tremendous amount of foodborne illnesses every year through the consumption of contaminated food products. During their transit from contaminated food sources to the host gastrointestinal tract, these pathogens are exposed and must adapt to fluctuating oxygen levels to successfully colonize the host and cause diseases. However, the majority of enteric infection research has been conducted under aerobic conditions. To raise awareness of the importance in understanding the impact of oxygen, or lack of oxygen, on enteric pathogenesis, we describe in this review the metabolic and physiological responses of nine bacterial enteric pathogens exposed to environments with different oxygen levels. We further discuss the effects of oxygen levels on virulence regulation to establish potential connections between metabolic adaptations and bacterial pathogenesis. While not providing an exhaustive list of all bacterial pathogens, we highlight key differences and similarities among nine facultative anaerobic and microaerobic pathogens in this review to argue for a more in-depth understanding of the diverse impact oxygen levels have on enteric pathogenesis.
Collapse
Affiliation(s)
- N Wallace
- University of Dayton, Dayton, OH, United States
| | - A Zani
- University of Dayton, Dayton, OH, United States
| | - E Abrams
- University of Dayton, Dayton, OH, United States
| | - Y Sun
- University of Dayton, Dayton, OH, United States
| |
Collapse
|
35
|
Nitroreductase gene-directed enzyme prodrug therapy: insights and advances toward clinical utility. Biochem J 2015; 471:131-53. [PMID: 26431849 DOI: 10.1042/bj20150650] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
This review examines the vast catalytic and therapeutic potential offered by type I (i.e. oxygen-insensitive) nitroreductase enzymes in partnership with nitroaromatic prodrugs, with particular focus on gene-directed enzyme prodrug therapy (GDEPT; a form of cancer gene therapy). Important first indications of this potential were demonstrated over 20 years ago, for the enzyme-prodrug pairing of Escherichia coli NfsB and CB1954 [5-(aziridin-1-yl)-2,4-dinitrobenzamide]. However, it has become apparent that both the enzyme and the prodrug in this prototypical pairing have limitations that have impeded their clinical progression. Recently, substantial advances have been made in the biodiscovery and engineering of superior nitroreductase variants, in particular development of elegant high-throughput screening capabilities to enable optimization of desirable activities via directed evolution. These advances in enzymology have been paralleled by advances in medicinal chemistry, leading to the development of second- and third-generation nitroaromatic prodrugs that offer substantial advantages over CB1954 for nitroreductase GDEPT, including greater dose-potency and enhanced ability of the activated metabolite(s) to exhibit a local bystander effect. In addition to forging substantial progress towards future clinical trials, this research is supporting other fields, most notably the development and improvement of targeted cellular ablation capabilities in small animal models, such as zebrafish, to enable cell-specific physiology or regeneration studies.
Collapse
|
36
|
Ansell BRE, McConville MJ, Ma'ayeh SY, Dagley MJ, Gasser RB, Svärd SG, Jex AR. Drug resistance in Giardia duodenalis. Biotechnol Adv 2015; 33:888-901. [PMID: 25922317 DOI: 10.1016/j.biotechadv.2015.04.009] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 04/21/2015] [Accepted: 04/21/2015] [Indexed: 02/07/2023]
Abstract
Giardia duodenalis is a microaerophilic parasite of the human gastrointestinal tract and a major contributor to diarrheal and post-infectious chronic gastrointestinal disease world-wide. Treatment of G. duodenalis infection currently relies on a small number of drug classes. Nitroheterocyclics, in particular metronidazole, have represented the front line treatment for the last 40 years. Nitroheterocyclic-resistant G. duodenalis have been isolated from patients and created in vitro, prompting considerable research into the biomolecular mechanisms of resistance. These compounds are redox-active and are believed to damage proteins and DNA after being activated by oxidoreductase enzymes in metabolically active cells. In this review, we explore the molecular phenotypes of nitroheterocyclic-resistant G. duodenalis described to date in the context of the protist's unusual glycolytic and antioxidant systems. We propose that resistance mechanisms are likely to extend well beyond currently described resistance-associated enzymes (i.e., pyruvate ferredoxin oxidoreductases and nitroreductases), to include NAD(P)H- and flavin-generating pathways, and possibly redox-sensitive epigenetic regulation. Mechanisms that allow G. duodenalis to tolerate oxidative stress may lead to resistance against both oxygen and nitroheterocyclics, with implications for clinical control. The present review highlights the potential for systems biology tools and advanced bioinformatics to further investigate the multifaceted mechanisms of nitroheterocyclic resistance in this important pathogen.
Collapse
Affiliation(s)
- Brendan R E Ansell
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Cnr Park Dr and Flemington Rd, Parkville, VIC 3010, Australia.
| | - Malcolm J McConville
- Bio21 Institute, University of Melbourne, 30 Flemington Rd, Parkville, VIC 3010, Australia
| | - Showgy Y Ma'ayeh
- Department of Cell and Molecular Biology, Biomedical Center, Uppsala University, Box 596, SE-751 24 Uppsala, Sweden
| | - Michael J Dagley
- Bio21 Institute, University of Melbourne, 30 Flemington Rd, Parkville, VIC 3010, Australia
| | - Robin B Gasser
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Cnr Park Dr and Flemington Rd, Parkville, VIC 3010, Australia
| | - Staffan G Svärd
- Department of Cell and Molecular Biology, Biomedical Center, Uppsala University, Box 596, SE-751 24 Uppsala, Sweden
| | - Aaron R Jex
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Cnr Park Dr and Flemington Rd, Parkville, VIC 3010, Australia
| |
Collapse
|
37
|
Tu IF, Liao JH, Yang FL, Lin NT, Chan HL, Wu SH. Lon protease affects the RdxA nitroreductase activity and metronidazole susceptibility in Helicobacter pylori. Helicobacter 2014; 19:356-66. [PMID: 24834789 DOI: 10.1111/hel.12140] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND The lon gene of Helicobacter pylori strains is constitutively expressed during growth. However, virtually nothing is understood concerning the role of Lon in H. pylori. This study examined the function and physiological role of Lon in H. pylori (HpLon) using a trapping approach to identify putative Lon binding partners in the bacterium. MATERIALS AND METHODS Protease-deficient Lon was expressed and served as the bait in trapping approach to capture the interacting partners in H. pylori. The antibiotic susceptibility of wild-type and lon derivative mutants was determined by the E test trips and the disc diffusion assay. The effect of HpLon on RdxA activity was detected the change in NADPH oxidation and metronidazole reduction by spectrophotometer. RESULTS Lon in Helicobacter pylori (HpLon) interacting partners are mostly associated with metronidazole activation. lon mutant presents more susceptible to metronidazole than that of the wild type, and this phenotype is recovered by complementation of the wild-type Lon. We found that the ATPases associated with a variety of cellular activities (AAA(+) ) module of HpLon causes a decrease in both NADPH oxidase and Mtz reductase activity in RdxA, a major Mtz-activating enzyme in H. pylori. CONCLUSION Metronidazole resistance of H. pylori causes the serious medical problem worldwide. In this study, HpLon is involved in metronidazole susceptibility among H. pylori strains. We provide the evidence that HpLon alters RdxA activity in vitro. The decrease in metronidazole activation caused by HpLon is possibly prior to accumulate mutation in rdxA gene before the metronidazole-resistant strains to be occurred.
Collapse
Affiliation(s)
- I-Fan Tu
- Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, 300, Taiwan
| | | | | | | | | | | |
Collapse
|
38
|
Rasheed F, Campbell BJ, Alfizah H, Varro A, Zahra R, Yamaoka Y, Pritchard DM. Analysis of clinical isolates of Helicobacter pylori in Pakistan reveals high degrees of pathogenicity and high frequencies of antibiotic resistance. Helicobacter 2014; 19:387-99. [PMID: 24827414 PMCID: PMC4162849 DOI: 10.1111/hel.12142] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Antibiotic resistance in Helicobacter pylori contributes to failure in eradicating the infection and is most often due to point and missense mutations in a few key genes. METHODS The antibiotic susceptibility profiles of H. pylori isolates from 46 Pakistani patients were determined by Etest. Resistance and pathogenicity genes were amplified, and sequences were analyzed to determine the presence of mutations. RESULTS A high percentage of isolates (73.9%) were resistant to metronidazole (MTZ), with considerable resistance to clarithromycin (CLR; 47.8%) and amoxicillin (AML; 54.3%) also observed. Relatively few isolates were resistant to tetracycline (TET; 4.3%) or to ciprofloxacin (CIP; 13%). However, most isolates (n = 43) exhibited resistance to one or more antibiotics. MTZ-resistant isolates contained missense mutations in oxygen-independent NADPH nitroreductase (RdxA; 8 mutations found) and NADH flavin oxidoreductase (FrxA; 4 mutations found). In the 23S rRNA gene, responsible for CLR resistance, a new point mutation (A2181G) and 4 previously reported mutations were identified. Pathogenicity genes cagA, dupA, and vacA s1a/m1 were detected frequently in isolates which were also found to be resistant to MTZ, CLR, and AML. A high percentage of CagA and VacA seropositivity was also observed in these patients. Phylogenetic analysis of partial sequences showed uniform distribution of the 3' region of cagA throughout the tree. CONCLUSIONS We have identified H. pylori isolates in Pakistan which harbor pathogenicity genes and worrying antibiotic resistance profiles as a result of having acquired multiple point and missense mutations. H. pylori eradication regimens should therefore be reevaluated in this setting.
Collapse
Affiliation(s)
- Faisal Rasheed
- Department of Gastroenterology, Institute of Translational Medicine, University of Liverpool, Liverpool L69 3GE, UK,Department of Microbiology, Quaid-i-Azam University, Islamabad 45320, Pakistan
| | - Barry James Campbell
- Department of Gastroenterology, Institute of Translational Medicine, University of Liverpool, Liverpool L69 3GE, UK
| | - Hanafiah Alfizah
- Department of Medical Microbiology & Immunology, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre, 56000 Cheras, Kuala Lumpur, Malaysia
| | - Andrea Varro
- Department of Cellular & Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool L69 3GE, UK
| | - Rabaab Zahra
- Department of Microbiology, Quaid-i-Azam University, Islamabad 45320, Pakistan
| | - Yoshio Yamaoka
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu 870-1192, Japan,Department of Medicine-Gastroenterology, Michael E. DeBakey Veterans Affairs Medical Center and Baylor College of Medicine, Houston, TX 77030, USA
| | - David Mark Pritchard
- Department of Gastroenterology, Institute of Translational Medicine, University of Liverpool, Liverpool L69 3GE, UK
| |
Collapse
|
39
|
Justino MC, Parente MR, Boneca IG, Saraiva LM. FrxA is an S-nitrosoglutathione reductase enzyme that contributes to Helicobacter pylori pathogenicity. FEBS J 2014; 281:4495-505. [PMID: 25132107 DOI: 10.1111/febs.12958] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 07/28/2014] [Accepted: 08/04/2014] [Indexed: 01/06/2023]
Abstract
Helicobacter pylori is a pathogen that infects the gastric mucosa of a large percentage of the human population worldwide, and predisposes to peptic ulceration and gastric cancer. Persistent colonization of humans by H. pylori triggers an inflammatory response that leads to the production of reactive nitrogen species. However, the mechanisms of H. pylori defence against nitrosative stress remain largely unknown. In this study, we show that the NADH-flavin oxidoreductase FrxA of H. pylori, besides metabolizing nitrofurans and metronidazole, has S-nitrosoglutathione reductase activity. In agreement with this, inactivation of the FrxA-encoding gene resulted in a strain that was more sensitive to S-nitrosoglutathione. FrxA was also shown to contribute to the proliferation of H. pylori in macrophages, which are key phagocytic cells of the mammalian innate immune system. Moreover, FrxA was shown to support the virulence of the pathogen upon mouse infection. Altogether, we provide evidence for a new function of FrxA that contributes to the successful chronic colonization ability that characterizes H. pylori.
Collapse
Affiliation(s)
- Marta C Justino
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal; Escola Superior de Tecnologia do Barreiro, Instituto Politécnico de Setúbal, Barreiro, Portugal
| | | | | | | |
Collapse
|
40
|
Response to metronidazole and oxidative stress is mediated through homeostatic regulator HsrA (HP1043) in Helicobacter pylori. J Bacteriol 2013; 196:729-39. [PMID: 24296668 DOI: 10.1128/jb.01047-13] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Metronidazole (MTZ) is often used in combination therapies to treat infections caused by the gastric pathogen Helicobacter pylori. Resistance to MTZ results from loss-of-function mutations in genes encoding RdxA and FrxA nitroreductases. MTZ-resistant strains, when cultured at sub-MICs of MTZ (5 to 20 μg/ml), show dose-dependent defects in bacterial growth; depressed activities of many Krebs cycle enzymes, including pyruvate:ferredoxin oxidoreductase (PFOR); and low transcript levels of porGDAB (primer extension), phenotypes consistent with an involvement of a transcriptional regulator. Using a combination of protein purification steps, electrophoretic mobility shift assays (EMSAs), and mass spectrometry analyses of proteins bound to porG promoter sequences, we identified HP1043, an essential homeostatic global regulator (HsrA [for homeostatic stress regulator]). Competition EMSAs and supershift analyses with HsrA-enriched protein fractions confirmed specific binding to porGDAB and hsrA promoter sequences. Exposure to MTZ resulted in >10-fold decreases in levels of HsrA and in levels of the HsrA-regulated gene products PFOR and TlpB. Exposure to paraquat (PQ), hydrogen peroxide, or organic peroxides showed near equivalence with MTZ, revealing a common oxidative stress response pathway. Finally, direct superoxide dismutase (SOD) assays showed an inverse relationship between HsrA levels and SOD activity, suggesting that HsrA may serve as a repressor of sodB. As a homeostatic sentinel, HsrA appears to be ideally positioned to enable rapid shutdown of genes associated with metabolism and growth while activating (directly or indirectly) oxidative defense genes in response to low levels of toxic metabolites (MTZ or oxygen) before they reach DNA-damaging levels.
Collapse
|
41
|
Galano JJ, Alías M, Pérez R, Velázquez-Campoy A, Hoffman PS, Sancho J. Improved Flavodoxin Inhibitors with Potential Therapeutic Effects against Helicobacter pylori Infection. J Med Chem 2013; 56:6248-58. [DOI: 10.1021/jm400786q] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Juan J. Galano
- Departamento
de Bioquímica
y Biología Molecular y Celular, Facultad de Ciencias, Universidad de Zaragoza, 50009, Zaragoza, Spain
- Institute for Biocomputation and Physics of Complex Systems (BIFI), Joint Unit BIFI-IQFR (CSIC), Edificio I + D, Mariano Esquillor, 50018, Zaragoza, Spain
| | - Miriam Alías
- Departamento
de Bioquímica
y Biología Molecular y Celular, Facultad de Ciencias, Universidad de Zaragoza, 50009, Zaragoza, Spain
- Institute for Biocomputation and Physics of Complex Systems (BIFI), Joint Unit BIFI-IQFR (CSIC), Edificio I + D, Mariano Esquillor, 50018, Zaragoza, Spain
| | - Reyes Pérez
- Departamento
de Bioquímica
y Biología Molecular y Celular, Facultad de Ciencias, Universidad de Zaragoza, 50009, Zaragoza, Spain
- Institute for Biocomputation and Physics of Complex Systems (BIFI), Joint Unit BIFI-IQFR (CSIC), Edificio I + D, Mariano Esquillor, 50018, Zaragoza, Spain
| | - Adrian Velázquez-Campoy
- Departamento
de Bioquímica
y Biología Molecular y Celular, Facultad de Ciencias, Universidad de Zaragoza, 50009, Zaragoza, Spain
- Institute for Biocomputation and Physics of Complex Systems (BIFI), Joint Unit BIFI-IQFR (CSIC), Edificio I + D, Mariano Esquillor, 50018, Zaragoza, Spain
- Fundación ARAID, Gobierno de Aragon, Aragon, Spain
| | - Paul S. Hoffman
- Department of Medicine, Division
of Infectious Diseases and International Health, University of Virginia Health System, Charlottesville, Virginia
22908, United States
| | - Javier Sancho
- Departamento
de Bioquímica
y Biología Molecular y Celular, Facultad de Ciencias, Universidad de Zaragoza, 50009, Zaragoza, Spain
- Institute for Biocomputation and Physics of Complex Systems (BIFI), Joint Unit BIFI-IQFR (CSIC), Edificio I + D, Mariano Esquillor, 50018, Zaragoza, Spain
| |
Collapse
|
42
|
Antimicrobial susceptibility and resistance patterns among Helicobacter pylori strains from The Gambia, West Africa. Antimicrob Agents Chemother 2012; 57:1231-7. [PMID: 23263004 DOI: 10.1128/aac.00517-12] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Helicobacter pylori is a globally important and genetically diverse gastric pathogen that infects most people in developing countries. Eradication efforts are complicated by antibiotic resistance, which varies in frequency geographically. There are very few data on resistance in African strains. Sixty-four Gambian H. pylori strains were tested for antibiotic susceptibility. The role of rdxA in metronidazole (Mtz) susceptibility was tested by DNA transformation and sequencing; RdxA protein variants were interpreted in terms of RdxA structure. Forty-four strains (69%) were resistant to at least 8 μg of Mtz/ml. All six strains from infants, but only 24% of strains from adults, were sensitive (P = 0.0031). Representative Mtz-resistant (Mtz(r)) strains were rendered Mtz susceptible (Mtz(s)) by transformation with a functional rdxA gene; conversely, Mtz(s) strains were rendered Mtz(r) by rdxA inactivation. Many mutations were found by Gambian H. pylori rdxA sequencing; mutations that probably inactivated rdxA in Mtz(r) strains were identified and explained using RdxA protein's structure. All of the strains were sensitive to clarithromycin and erythromycin. Amoxicillin and tetracycline resistance was rare. Sequence analysis indicated that most tetracycline resistance, when found, was not due to 16S rRNA gene mutations. These data suggest caution in the use of Mtz-based therapies in The Gambia. The increasing use of macrolides against respiratory infections in The Gambia calls for continued antibiotic susceptibility monitoring. The rich variety of rdxA mutations that we found will be useful in further structure-function studies of RdxA, the enzyme responsible for Mtz susceptibility in this important pathogen.
Collapse
|