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Rep V, Štulić R, Koštrun S, Kuridža B, Crnolatac I, Radić Stojković M, Paljetak HČ, Perić M, Matijašić M, Raić-Malić S. Novel tetrahydropyrimidinyl-substituted benzimidazoles and benzothiazoles: synthesis, antibacterial activity, DNA interactions and ADME profiling. RSC Med Chem 2022; 13:1504-1525. [PMID: 36561067 PMCID: PMC9749923 DOI: 10.1039/d2md00143h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 07/12/2022] [Indexed: 12/25/2022] Open
Abstract
A series of tetrahydropyrimidinyl-substituted benzimidazoles attached to various aliphatic or aromatic residues via phenoxymethylene were synthesised to investigate their antibacterial activities against selected Gram-positive and Gram-negative bacteria. The influence of the type of substituent at the C-3 and C-4 positions of the phenoxymethylene linker on the antibacterial activity was observed, showing that the aromatic moiety improved the antibacterial potency. Of all the evaluated compounds, benzoyl-substituted benzimidazole derivative 15a was the most active compound, particularly against the Gram-negative pathogens E. coli (MIC = 1 μg mL-1) and M. catarrhalis (MIC = 2 μg mL-1). Compound 15a also exhibited the most promising antibacterial activity against sensitive and resistant strains of S. pyogenes (MIC = 2 μg mL-1). Significant stabilization effects and positive induced CD bands strongly support the binding of the most biologically active benzimidazoles inside the minor grooves of AT-rich DNA, in line with docking studies. The predicted physico-chemical and ADME properties lie within drug-like space except for low membrane permeability, which needs further optimization. Our findings encourage further development of novel structurally related 5(6)-tetrahydropyrimidinyl substituted benzimidazoles in order to optimize their antibacterial effect against common respiratory pathogens.
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Affiliation(s)
- Valentina Rep
- Department of Organic Chemistry, Faculty of Chemical Engineering and Technology, University of ZagrebMarulićev trg 1910000 ZagrebCroatia
| | - Rebeka Štulić
- Department of Organic Chemistry, Faculty of Chemical Engineering and Technology, University of ZagrebMarulićev trg 1910000 ZagrebCroatia
| | - Sanja Koštrun
- Selvita d.o.oPrilaz baruna Filipovića 2910000 ZagrebCroatia
| | - Bojan Kuridža
- Ruđer Bošković Institute, Division of Organic Chemistry and BiochemistryBijenička cesta 5410000 ZagrebCroatia
| | - Ivo Crnolatac
- Ruđer Bošković Institute, Division of Organic Chemistry and BiochemistryBijenička cesta 5410000 ZagrebCroatia
| | - Marijana Radić Stojković
- Ruđer Bošković Institute, Division of Organic Chemistry and BiochemistryBijenička cesta 5410000 ZagrebCroatia
| | - Hana Čipčić Paljetak
- Department for Intercellular Communication, Center for Translational and Clinical Research, University of Zagreb School of MedicineŠalata 210000 ZagrebCroatia
| | - Mihaela Perić
- Department for Intercellular Communication, Center for Translational and Clinical Research, University of Zagreb School of MedicineŠalata 210000 ZagrebCroatia
| | - Mario Matijašić
- Department for Intercellular Communication, Center for Translational and Clinical Research, University of Zagreb School of MedicineŠalata 210000 ZagrebCroatia
| | - Silvana Raić-Malić
- Department of Organic Chemistry, Faculty of Chemical Engineering and Technology, University of ZagrebMarulićev trg 1910000 ZagrebCroatia
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Chen H, Bai X, Gao Y, Liu W, Yao X, Wang J. Profile of Bacteria with ARGs Among Real-World Samples from ICU Admission Patients with Pulmonary Infection Revealed by Metagenomic NGS. Infect Drug Resist 2021; 14:4993-5004. [PMID: 34866919 PMCID: PMC8636693 DOI: 10.2147/idr.s335864] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 11/16/2021] [Indexed: 12/27/2022] Open
Abstract
Background Treatment of pulmonary infections in the intensive care unit (ICU) represents a great challenge, especially infections caused by antibiotic resistance pathogens. A thorough and up-to-date knowledge of the local spectrum of antibiotic resistant bacteria can improve the antibiotic treatment efficiency. In this study, we aimed to reveal the profile of bacteria with antibiotic resistance genes (ARGs) in real-world samples from ICU admission patients with pulmonary infection in Mainland, China, by metagenomic next-generation sequencing (mNGS). Methods A total of 504 different types of clinical samples from 452 ICU admission patients with pulmonary infection were detected by mNGS analysis. Results A total of 485 samples from 434 patients got successful mNGS results. Among 434 patients, one or more bacteria with ARGs were detected in 192 patients (44.24%, 192/434), and ≥2 bacteria with ARGs were detected in 85 (19.59%, 85/434) patients. The predominant detected bacteria were Corynebacterium striatum (C. striatum) (11.76%, 51/434), Acinetobacter baumannii (A. baumannii) (11.52%, 50/434) and Enterococcus faecium (E. faecium) (8.99%, 39/434). ermX conferred resistance to MSLB and cmx to phenicol were the only two ARGs detected in C. striatum; in A. baumannii, most of ARGs were resistance-nodulation-division (RND)-type efflux pumps genes, which conferred resistance to multi-drug; ermB conferred resistance to MSLB and efmA to multi-drug were the predominant ARGs in E. faecium. Bacteria with ARGs were detected in 50% (140/280) bronchoalveolar lavage fluid (BALF) and 50.5% (48/95) sputum samples, which were significantly higher than in blood and cerebrospinal fluid (CSF) samples. Conclusion High level of bacteria with ARGs was observed in clinical samples, especially BALF and sputum samples from ICU admission patients with pulmonary infection in Mainland, China. And C. striatum resistant to MSLB and/or phenicol, multi-drug resistance A. baumannii and E. faecium were the lead bacteria.
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Affiliation(s)
- Huijuan Chen
- Department of Biomedical Engineering, College of Life Science and Bioengineering, Beijing University of Technology, Beijing, People's Republic of China
| | - Xinhua Bai
- Department of Clinical Laboratory, Beijing Capitalbio Medlab, Beijing, People's Republic of China
| | - Yang Gao
- Department of Clinical Laboratory, Beijing Capitalbio Medlab, Beijing, People's Republic of China
| | - Wenxuan Liu
- Department of Clinical Laboratory, Beijing Capitalbio Medlab, Beijing, People's Republic of China
| | - Xuena Yao
- Department of Clinical Laboratory, Beijing Capitalbio Medlab, Beijing, People's Republic of China
| | - Jing Wang
- Department of Clinical Laboratory, Beijing Capitalbio Medlab, Beijing, People's Republic of China
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Linear regression equations to predict β-lactam, macrolide, lincosamide and fluoroquinolone minimum inhibitory concentrations from molecular antimicrobial resistance determinants in Streptococcus pneumoniae. Antimicrob Agents Chemother 2021; 66:e0137021. [PMID: 34662197 PMCID: PMC8765234 DOI: 10.1128/aac.01370-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Antimicrobial resistance in Streptococcus pneumoniae represents a threat to public health and monitoring the dissemination of resistant strains is essential to guiding health policy. Multiple-variable linear regression modeling was used to determine the contributions of molecular antimicrobial resistance determinants to antimicrobial minimum inhibitory concentration (MIC) for penicillin, ceftriaxone, erythromycin, clarithromycin, clindamycin, levofloxacin, and trimethoprim/sulfamethoxazole. Training data sets consisting of Canadian S. pneumoniae isolated from 1995 to 2019 were used to generate multiple-variable linear regression equations for each antimicrobial. The regression equations were then applied to validation data sets of Canadian (n=439) and USA (n=607 and n=747) isolates. The MIC for β-lactam antimicrobials were fully explained by amino acid substitutions in motif regions of the penicillin binding proteins PBP1a, PPB2b, and PBP2x. Accuracy of predicted MICs within one doubling dilution to phenotypically determined MICs for penicillin was 97.4%, ceftriaxone 98.2%; erythromycin 94.8%; clarithromycin 96.6%; clindamycin 98.2%; levofloxacin 100%; and trimethoprim/sulfamethoxazole 98.8%; with an overall sensitivity of 95.8% and specificity of 98.0%. Accuracy of predicted MICs to the phenotypically determined MICs was similar to phenotype-only MIC comparison studies. The ability to acquire detailed antimicrobial resistance information directly from molecular determinants will facilitate the transition from routine phenotypic testing to whole genome sequencing analysis and can fill the surveillance gap in an era of increased reliance on nucleic acid assay diagnostics to better monitor the dynamics of S. pneumoniae.
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Veeraraghavan B, Varghese R, Saigal K, Balasubramanian S, Bai PSP, Lal Y B, Neeravi A, Baskar P, Anandhan K, Kumar CPG, Jayaraman Y, Nag VL, Baveja S, J B, Joshi SA, Iyer R. Activity of novel lactone ketolide nafithromycin against multicentric invasive and non-invasive pneumococcal isolates collected in India. JAC Antimicrob Resist 2021; 3:dlab066. [PMID: 34223128 PMCID: PMC8210042 DOI: 10.1093/jacamr/dlab066] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 04/13/2021] [Indexed: 11/13/2022] Open
Abstract
Background India is among the nations reporting substantial healthcare burden linked to pneumococcal infections. Nafithromycin is a novel lactone ketolide antibiotic, which recently entered Phase 3 development in India for the indication of community-acquired bacterial pneumonia (CABP). Objectives To assess the in vitro activity of nafithromycin against serotyped invasive and non-invasive Streptococcus pneumoniae isolates, collected from nine medical centres across India. Methods A total of 534 isolates of S. pneumoniae were collected during 2015–20 and serotyped as per CDC protocol. A subset of erythromycin-non-susceptible S. pneumoniae (n = 200) was screened for the presence of erm(B) and mef(A/E) genes. A subset of MDR isolates (n = 54) were also subjected to MLST. The MICs of antibiotics were determined by the reference agar-dilution method (CLSI). Susceptibilities of the comparators were interpreted as per CLSI criteria. Results Fifty-nine distinct serotypes were identified among the 534 isolates. Among erythromycin-non-susceptible isolates, erm(B) and mef(A/E) genes were found in 49% and 59% strains respectively, while MLST showed clonal diversity. Azithromycin (67.6% non-susceptible) and clindamycin (31.8% non-susceptible) showed limited activity. Penicillin (for non-meningitis) or quinolone non-susceptibility was low (<11% and <6%, respectively). Nafithromycin showed potent activity with MIC50 and MIC90 of 0.015–0.03 and 0.06 mg/L, respectively, regardless of the macrolide resistance mechanisms. Conclusions Indian pneumococcal isolates show poor susceptibilities to macrolides, in concordance with the global trend. Nafithromycin overcomes erm as well as mef-mediated macrolide resistance mechanisms expressed individually or concurrently in S. pneumoniae. This study supports continued clinical development of nafithromycin for pneumococcal infections including CABP.
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Affiliation(s)
| | | | | | - S Balasubramanian
- Kanchi Kamakoti Children's Trust Hospital, Chennai, Tamil Nadu, India
| | | | - Binesh Lal Y
- Christian Medical College, Vellore, Tamil Nadu, India
| | | | | | | | - C P Girish Kumar
- ICMR-National Institute of Epidemiology, Chennai, Tamil Nadu, India
| | - Yuvraj Jayaraman
- ICMR-National Institute of Epidemiology, Chennai, Tamil Nadu, India
| | | | - Sujata Baveja
- Lokmanya Tilak Municipal Medical College and Hospital, Sion, Mumbai, India
| | - Bhavana J
- Indira Gandhi Institute of Child Health, Bengaluru, India
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Milaković M, Križanović S, Petrić I, Šimatović A, González-Plaza JJ, Gužvinec M, Andrašević AT, Pole L, Fuka MM, Udiković-Kolić N. Characterization of macrolide resistance in bacteria isolated from macrolide-polluted and unpolluted river sediments and clinical sources in Croatia. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 749:142357. [PMID: 33370905 DOI: 10.1016/j.scitotenv.2020.142357] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 09/10/2020] [Accepted: 09/10/2020] [Indexed: 06/12/2023]
Abstract
Environments polluted with excessively high levels of antibiotics released from manufacturing sites can act as a source of transferable antibiotic resistance (AR) genes to human commensal and pathogenic bacteria. The aim of this study was to evaluate AR of bacteria isolated from the Sava river sediments (Croatia) at the discharge site of effluents from azithromycin production compared to those from the upstream site and isolates collected in Croatian hospitals. A total of 228 environmental strains of azithromycin-resistant bacteria were isolated and identified, with 124 from the discharge site and 104 from the upstream site. In addition, a total of 90 clinical, azithromycin-resistant streptococcal and staphylococcal isolates obtained from the Croatian Reference Center for Antibiotic Resistance Surveillance were analyzed. PCR screening of isolates on 11 relevant macrolide-resistance genes (MRGs) showed that discharge isolates had greater detection frequencies for 4 gene targets (ermB, msrE, mphE and ermF) compared to upstream isolates. Among clinical isolates, the most frequently detected gene was ermB, followed by msrD, mefE and mefC. The discharge site demonstrated a greater abundance of isolates with co-occurrence of two different MRGs (predominantly msrE-mphE) than the upstream site, but a lower abundance than the clinical sources (most commonly msrD-mefE). The simultaneous presence of three or even four MRGs was specific for the discharge and clinical isolates, but not for the upstream isolates. When MRG results were sorted by gene mechanism, the ribosomal methylation (erm) and protection genes (msr) were the most frequently detected among both the discharge and the clinical isolates. Following sequencing, high nucleotide sequence similarity was observed between ermB in the discharge isolates and the clinical streptococcal isolates, suggesting a possible transfer of the ermB gene between bacteria of clinical and environmental origin. Our study highlights the importance of environmental bacterial populations as reservoirs for clinically relevant macrolide-resistance genes.
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Affiliation(s)
- Milena Milaković
- Division for Marine and Environmental Research, Ruđer Bošković Institute, Bijenička 54, P.O. Box 180, 10 002 Zagreb, Croatia
| | - Stela Križanović
- Division for Marine and Environmental Research, Ruđer Bošković Institute, Bijenička 54, P.O. Box 180, 10 002 Zagreb, Croatia
| | - Ines Petrić
- Division for Marine and Environmental Research, Ruđer Bošković Institute, Bijenička 54, P.O. Box 180, 10 002 Zagreb, Croatia
| | - Ana Šimatović
- Division of Physical Chemistry, Ruđer Bošković Institute, Bijenička 54, P.O. Box 180, 10 002 Zagreb, Croatia
| | - Juan J González-Plaza
- Division for Marine and Environmental Research, Ruđer Bošković Institute, Bijenička 54, P.O. Box 180, 10 002 Zagreb, Croatia
| | - Marija Gužvinec
- Department of Clinical Microbiology, University Hospital for Infectious Diseases, Mirogojska 8, 10 000 Zagreb, Croatia
| | - Arjana Tambić Andrašević
- Department of Clinical Microbiology, University Hospital for Infectious Diseases, Mirogojska 8, 10 000 Zagreb, Croatia
| | - Lucia Pole
- Department of Microbiology, University of Zagreb, Faculty of Agriculture, Svetošimunska 25, 10 000 Zagreb, Croatia
| | - Mirna Mrkonjić Fuka
- Department of Microbiology, University of Zagreb, Faculty of Agriculture, Svetošimunska 25, 10 000 Zagreb, Croatia
| | - Nikolina Udiković-Kolić
- Division for Marine and Environmental Research, Ruđer Bošković Institute, Bijenička 54, P.O. Box 180, 10 002 Zagreb, Croatia.
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Mechanism of Macrolide-Induced Inhibition of Pneumolysin Release Involves Impairment of Autolysin Release in Macrolide-Resistant Streptococcus pneumoniae. Antimicrob Agents Chemother 2018; 62:AAC.00161-18. [PMID: 30181369 DOI: 10.1128/aac.00161-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 08/27/2018] [Indexed: 11/20/2022] Open
Abstract
Streptococcus pneumoniae is a leading cause of community-acquired pneumonia. Over the past 2 decades, macrolide resistance among S. pneumoniae organisms has been increasing steadily and has escalated at an alarming rate worldwide. However, the use of macrolides in the treatment of community-acquired pneumonia has been reported to be effective regardless of the antibiotic susceptibility of the causative pneumococci. Although previous studies suggested that sub-MICs of macrolides inhibit the production of the pneumococcal pore-forming toxin pneumolysin by macrolide-resistant S. pneumoniae (MRSP), the underlying mechanisms of the inhibitory effect have not been fully elucidated. Here, we show that the release of pneumococcal autolysin, which promotes cell lysis and the release of pneumolysin, was inhibited by treatment with azithromycin and erythromycin, whereas replenishing with recombinant autolysin restored the release of pneumolysin from MRSP. Additionally, macrolides significantly downregulated ply transcription followed by a slight decrease of the intracellular pneumolysin level. These findings suggest the mechanisms involved in the inhibition of pneumolysin in MRSP, which may provide an additional explanation for the benefits of macrolides on the outcome of treatment for pneumococcal diseases.
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Fyfe C, Grossman TH, Kerstein K, Sutcliffe J. Resistance to Macrolide Antibiotics in Public Health Pathogens. Cold Spring Harb Perspect Med 2016; 6:a025395. [PMID: 27527699 PMCID: PMC5046686 DOI: 10.1101/cshperspect.a025395] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Macrolide resistance mechanisms can be target-based with a change in a 23S ribosomal RNA (rRNA) residue or a mutation in ribosomal protein L4 or L22 affecting the ribosome's interaction with the antibiotic. Alternatively, mono- or dimethylation of A2058 in domain V of the 23S rRNA by an acquired rRNA methyltransferase, the product of an erm (erythromycin ribosome methylation) gene, can interfere with antibiotic binding. Acquired genes encoding efflux pumps, most predominantly mef(A) + msr(D) in pneumococci/streptococci and msr(A/B) in staphylococci, also mediate resistance. Drug-inactivating mechanisms include phosphorylation of the 2'-hydroxyl of the amino sugar found at position C5 by phosphotransferases and hydrolysis of the macrocyclic lactone by esterases. These acquired genes are regulated by either translation or transcription attenuation, largely because cells are less fit when these genes, especially the rRNA methyltransferases, are highly induced or constitutively expressed. The induction of gene expression is cleverly tied to the mechanism of action of macrolides, relying on antibiotic-bound ribosomes stalled at specific sequences of nascent polypeptides to promote transcription or translation of downstream sequences.
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Affiliation(s)
- Corey Fyfe
- Tetraphase Pharmaceuticals, Watertown, Massachusetts 02472
| | | | - Kathy Kerstein
- Tetraphase Pharmaceuticals, Watertown, Massachusetts 02472
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Inducible Expression of both ermB and ermT Conferred High Macrolide Resistance in Streptococcus gallolyticus subsp. pasteurianus Isolates in China. Int J Mol Sci 2016; 17:ijms17101599. [PMID: 27669217 PMCID: PMC5085632 DOI: 10.3390/ijms17101599] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 09/11/2016] [Accepted: 09/12/2016] [Indexed: 11/16/2022] Open
Abstract
Streptococcus gallolyticus subsp. pasteurianus is an under-recognized pathogen and zoonotic agent causing opportunistic infections in humans. Despite increasing recognition of this subspecies as a cause for human infectious diseases, limited information is known about its antibiotic resistance mechanism. In this study, we aim to identify the molecular mechanism underlying the high macrolide resistance of six S. gallolyticus subsp. pasteurianus isolates from dead ducklings collected in several natural outbreaks in China during 2010–2013. All isolates exhibited multi-drug resistance including high macrolide resistance (MIC ≥ 1024 mg/L for erythromycin, and 512 mg/L for clarithromycin). Efflux-encoding mefA and mefE genes were not detectable in these isolates. The presence of 23S rRNA mutations in specific isolates did not significantly change macrolide MICs. No nucleotide substitutions were found in genes encoding ribosomal proteins L4 or L22. The ermB and ermT genes were found in the genomes of all isolates. These two genes were acquired independently in one highly virulent isolate AL101002, and clustered with Tn916 and IS1216, respectively. The expression of both ermB and ermT in all isolates was erythromycin inducible and yielded comparable macrolide MICs in all six isolates. Taken together, inducible expression of both ermB and ermT conferred high macrolide resistance in these S. gallolyticus subsp. pasterianus isolates. Our findings reveal new macrolide resistance features in S. gallolyticus subsp. pasteurianus by both ermB and ermT.
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Schroeder MR, Stephens DS. Macrolide Resistance in Streptococcus pneumoniae. Front Cell Infect Microbiol 2016; 6:98. [PMID: 27709102 PMCID: PMC5030221 DOI: 10.3389/fcimb.2016.00098] [Citation(s) in RCA: 116] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 08/26/2016] [Indexed: 01/21/2023] Open
Abstract
Streptococcus pneumoniae is a common commensal and an opportunistic pathogen. Suspected pneumococcal upper respiratory infections and pneumonia are often treated with macrolide antibiotics. Macrolides are bacteriostatic antibiotics and inhibit protein synthesis by binding to the 50S ribosomal subunit. The widespread use of macrolides is associated with increased macrolide resistance in S. pneumoniae, and the treatment of pneumococcal infections with macrolides may be associated with clinical failures. In S. pneumoniae, macrolide resistance is due to ribosomal dimethylation by an enzyme encoded by erm(B), efflux by a two-component efflux pump encoded by mef (E)/mel(msr(D)) and, less commonly, mutations of the ribosomal target site of macrolides. A wide array of genetic elements have emerged that facilitate macrolide resistance in S. pneumoniae; for example erm(B) is found on Tn917, while the mef (E)/mel operon is carried on the 5.4- or 5.5-kb Mega element. The macrolide resistance determinants, erm(B) and mef (E)/mel, are also found on large composite Tn916-like elements most notably Tn6002, Tn2009, and Tn2010. Introductions of 7-valent and 13-valent pneumococcal conjugate vaccines (PCV-7 and PCV-13) have decreased the incidence of macrolide-resistant invasive pneumococcal disease, but serotype replacement and emergence of macrolide resistance remain an important concern.
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Affiliation(s)
| | - David S Stephens
- Departments of Medicine, Emory UniversityAtlanta, GA, USA; Departments of Microbiology and Immunology, Emory UniversityAtlanta, GA, USA; Departments of Epidemiology, Emory UniversityAtlanta, GA, USA
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Hernando-Amado S, Blanco P, Alcalde-Rico M, Corona F, Reales-Calderón JA, Sánchez MB, Martínez JL. Multidrug efflux pumps as main players in intrinsic and acquired resistance to antimicrobials. Drug Resist Updat 2016; 28:13-27. [PMID: 27620952 DOI: 10.1016/j.drup.2016.06.007] [Citation(s) in RCA: 120] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 05/31/2016] [Accepted: 06/23/2016] [Indexed: 12/31/2022]
Abstract
Multidrug efflux pumps constitute a group of transporters that are ubiquitously found in any organism. In addition to other functions with relevance for the cell physiology, efflux pumps contribute to the resistance to compounds used for treating different diseases, including resistance to anticancer drugs, antibiotics or antifungal compounds. In the case of antimicrobials, efflux pumps are major players in both intrinsic and acquired resistance to drugs currently in use for the treatment of infectious diseases. One important aspect not fully explored of efflux pumps consists on the identification of effectors able to induce their expression. Indeed, whereas the analysis of clinical isolates have shown that mutants overexpressing these resistance elements are frequently found, less is known on the conditions that may trigger expression of efflux pumps, hence leading to transient induction of resistance in vivo, a situation that is barely detectable using classical susceptibility tests. In the current article we review the structure and mechanisms of regulation of the expression of bacterial and fungal efflux pumps, with a particular focus in those for which a role in clinically relevant resistance has been reported.
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Affiliation(s)
- Sara Hernando-Amado
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Darwin 3, Cantoblanco, 28049 Madrid, Spain
| | - Paula Blanco
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Darwin 3, Cantoblanco, 28049 Madrid, Spain
| | - Manuel Alcalde-Rico
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Darwin 3, Cantoblanco, 28049 Madrid, Spain
| | - Fernando Corona
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Darwin 3, Cantoblanco, 28049 Madrid, Spain
| | - Jose A Reales-Calderón
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Darwin 3, Cantoblanco, 28049 Madrid, Spain
| | - María B Sánchez
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Darwin 3, Cantoblanco, 28049 Madrid, Spain
| | - José L Martínez
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Darwin 3, Cantoblanco, 28049 Madrid, Spain.
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11
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Chancey ST, Agrawal S, Schroeder MR, Farley MM, Tettelin H, Stephens DS. Composite mobile genetic elements disseminating macrolide resistance in Streptococcus pneumoniae. Front Microbiol 2015; 6:26. [PMID: 25709602 PMCID: PMC4321634 DOI: 10.3389/fmicb.2015.00026] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 01/08/2015] [Indexed: 01/17/2023] Open
Abstract
Macrolide resistance in Streptococcus pneumoniae emerged in the U.S. and globally during the early 1990's. The RNA methylase encoded by erm(B) and the macrolide efflux genes mef(E) and mel were identified as the resistance determining factors. These genes are disseminated in the pneumococcus on mobile, often chimeric elements consisting of multiple smaller elements. To better understand the variety of elements encoding macrolide resistance and how they have evolved in the pre- and post-conjugate vaccine eras, the genomes of 121 invasive and ten carriage isolates from Atlanta from 1994 to 2011 were analyzed for mobile elements involved in the dissemination of macrolide resistance. The isolates were selected to provide broad coverage of the genetic variability of antibiotic resistant pneumococci and included 100 invasive isolates resistant to macrolides. Tn916-like elements carrying mef(E) and mel on the Macrolide Genetic Assembly (Mega) and erm(B) on the erm(B) element and Tn917 were integrated into the pneumococcal chromosome backbone and into larger Tn5253-like composite elements. The results reported here include identification of novel insertion sites for Mega and characterization of the insertion sites of Tn916-like elements in the pneumococcal chromosome and in larger composite elements. The data indicate that integration of elements by conjugation was infrequent compared to recombination. Thus, it appears that conjugative mobile elements allow the pneumococcus to acquire DNA from distantly related bacteria, but once integrated into a pneumococcal genome, transformation and recombination is the primary mechanism for transmission of novel DNA throughout the pneumococcal population.
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Affiliation(s)
- Scott T Chancey
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine Atlanta, GA, USA ; Laboratories of Microbial Pathogenesis, Department of Veterans Affairs Medical Center Atlanta, GA, USA
| | - Sonia Agrawal
- Institute for Genome Sciences, University of Maryland School of Medicine Baltimore, MD, USA
| | - Max R Schroeder
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine Atlanta, GA, USA ; Laboratories of Microbial Pathogenesis, Department of Veterans Affairs Medical Center Atlanta, GA, USA
| | - Monica M Farley
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine Atlanta, GA, USA ; Laboratories of Microbial Pathogenesis, Department of Veterans Affairs Medical Center Atlanta, GA, USA
| | - Hervé Tettelin
- Institute for Genome Sciences, University of Maryland School of Medicine Baltimore, MD, USA ; Department of Microbiology and Immunology, University of Maryland School of Medicine Baltimore, MD, USA
| | - David S Stephens
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine Atlanta, GA, USA ; Laboratories of Microbial Pathogenesis, Department of Veterans Affairs Medical Center Atlanta, GA, USA
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Thumu S, Halami P. Phenotypic expression, molecular characterization and transferability of erythromycin resistance genes in Enterococcus
spp. isolated from naturally fermented food. J Appl Microbiol 2013; 116:689-99. [DOI: 10.1111/jam.12386] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Revised: 11/05/2013] [Accepted: 11/05/2013] [Indexed: 11/29/2022]
Affiliation(s)
- S.C.R. Thumu
- Food Microbiology Department; CSIR-Central Food Technological Research Institute; Mysore India
| | - P.M. Halami
- Food Microbiology Department; CSIR-Central Food Technological Research Institute; Mysore India
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13
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Magee TV, Han S, McCurdy SP, Nguyen TT, Granskog K, Marr ES, Maguire BA, Huband MD, Chen JM, Subashi TA, Shanmugasundaram V. Novel 3-O-carbamoyl erythromycin A derivatives (carbamolides) with activity against resistant staphylococcal and streptococcal isolates. Bioorg Med Chem Lett 2013; 23:1727-31. [PMID: 23414806 DOI: 10.1016/j.bmcl.2013.01.067] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 01/07/2013] [Accepted: 01/16/2013] [Indexed: 11/30/2022]
Abstract
A novel series of 3-O-carbamoyl erythromycin A derived analogs, labeled carbamolides, with activity versus resistant bacterial isolates of staphylococci (including macrolide and oxazolidinone resistant strains) and streptococci are reported. An (R)-2-aryl substituent on a pyrrolidine carbamate appeared to be critical for achieving potency against resistant strains. Crystal structures showed a distinct aromatic interaction between the (R)-2-aryl (3-pyridyl for 4d) substituent on the pyrrolidine and G2484 (G2505, Escherichia coli) of the Deinococcus radiodurans 50S ribosome (3.2Å resolution).
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Affiliation(s)
- Thomas V Magee
- Pfizer Cardiovascular, Metabolic, and Endocrine Diseases (CVMED) Chemistry, 620 Memorial Dr, Cambridge, MA 02139, USA.
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14
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Chancey ST, Zhou X, Zähner D, Stephens DS. Induction of efflux-mediated macrolide resistance in Streptococcus pneumoniae. Antimicrob Agents Chemother 2011; 55:3413-22. [PMID: 21537010 PMCID: PMC3122420 DOI: 10.1128/aac.00060-11] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2011] [Accepted: 04/25/2011] [Indexed: 01/17/2023] Open
Abstract
The antimicrobial efflux system encoded by the operon mef(E)-mel on the mobile genetic element MEGA in Streptococcus pneumoniae and other Gram-positive bacteria is inducible by macrolide antibiotics and antimicrobial peptides. Induction may affect the clinical response to the use of macrolides. We developed mef(E) reporter constructs and a disk diffusion induction and resistance assay to determine the kinetics and basis of mef(E)-mel induction. Induction occurred rapidly, with a >15-fold increase in transcription within 1 h of exposure to subinhibitory concentrations of erythromycin. A spectrum of environmental conditions, including competence and nonmacrolide antibiotics with distinct cellular targets, did not induce mef(E). Using 16 different structurally defined macrolides, induction was correlated with the amino sugar attached to C-5 of the macrolide lactone ring, not with the size (e.g., 14-, 15- or 16-member) of the ring or with the presence of the neutral sugar cladinose at C-3. Macrolides with a monosaccharide attached to C-5, known to block exit of the nascent peptide from the ribosome after the incorporation of up to eight amino acids, induced mef(E) expression. Macrolides with a C-5 disaccharide, which extends the macrolide into the ribosomal exit tunnel, disrupting peptidyl transferase activity, did not induce it. The induction of mef(E) did not require macrolide efflux, but the affinity of macrolides for the ribosome determined the availability for efflux and pneumococcal susceptibility. The induction of mef(E)-mel expression by inducing macrolides appears to be based on specific interactions of the macrolide C-5 saccharide with the ribosome that alleviate transcriptional attenuation of mef(E)-mel.
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Affiliation(s)
- Scott T. Chancey
- Division of Infectious Diseases, Department of Medicine
- Department of Veterans Affairs Medical Center, Atlanta, Georgia 30033
| | - Xiaoliu Zhou
- Division of Infectious Diseases, Department of Medicine
- Department of Veterans Affairs Medical Center, Atlanta, Georgia 30033
| | - Dorothea Zähner
- Division of Infectious Diseases, Department of Medicine
- Department of Veterans Affairs Medical Center, Atlanta, Georgia 30033
| | - David S. Stephens
- Division of Infectious Diseases, Department of Medicine
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia 30322
- Department of Veterans Affairs Medical Center, Atlanta, Georgia 30033
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15
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Human antimicrobial peptide LL-37 induces MefE/Mel-mediated macrolide resistance in Streptococcus pneumoniae. Antimicrob Agents Chemother 2010; 54:3516-9. [PMID: 20498319 DOI: 10.1128/aac.01756-09] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Macrolide resistance is a major concern in the treatment of Streptococcus pneumoniae. Inducible macrolide resistance in this pneumococcus is mediated by the efflux pump MefE/Mel. We show here that the human antimicrobial peptide LL-37 induces the mefE promoter and confers resistance to erythromycin and LL-37. Such induction may impact the efficacy of host defenses and of macrolide-based treatment of pneumococcal disease.
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16
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Cordeiro RP, Du T, Mulvey MR, Krause DO, Holley RA. Susceptibility of meat starter cultures to antimicrobials used in food animals in Canada. J Food Prot 2010; 73:916-22. [PMID: 20501043 DOI: 10.4315/0362-028x-73.5.916] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Lactic acid bacteria (LAB) are extensively used in the food industry for fermentation processes. However, it is possible that these bacteria may serve as a reservoir for antibiotic resistance genes that can be transferred to pathogens, giving rise to public health concerns. Animal operations that use antimicrobials as growth promotants have been linked to the origin of resistance due to the selective effect of low levels of antimicrobial used in this management strategy. The objective of this study was to determine the antimicrobial susceptibilities and mechanisms of resistance for 30 isolates of meat starter cultures commonly used in dry sausage fermentations to 20 antimicrobial agents. Susceptibility tests were performed by broth microdilution using Iso-Sensitest broth (90%, vol/vol) and de Man Rogosa Sharpe (MRS) broth (10%, vol/vol). The results showed that all 30 isolates exhibited resistance to at least three antimicrobials regardless of antimicrobial class while 17 or 30% of strains were resistant to antibiotics in three or six different classes, respectively. The incidence of antimicrobial resistance was higher among Pediococcus pentosaceus and lower for Staphylococcus carnosus strains. Genetic determinants for the lincosamide, macrolide, and tetracycline antimicrobials were not found using PCR. Phenotypic resistance in the absence of known resistance genes found here suggests that other mechanisms or genes might have contributed to the negative results. Further studies are needed to explore the genetic mechanisms underlying the prevalence of antibiotic resistance in Pediococcus species.
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Affiliation(s)
- R P Cordeiro
- Department of Food Science, University of Manitoba, Winnipeg, Manitoba R3T2N2, Canada
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17
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Rafie S, MacDougall C, James CL. Cethromycin: A Promising New Ketolide Antibiotic for Respiratory Infections. Pharmacotherapy 2010; 30:290-303. [DOI: 10.1592/phco.30.3.290] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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18
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Magee TV, Ripp SL, Li B, Buzon RA, Chupak L, Dougherty TJ, Finegan SM, Girard D, Hagen AE, Falcone MJ, Farley KA, Granskog K, Hardink JR, Huband MD, Kamicker BJ, Kaneko T, Knickerbocker MJ, Liras JL, Marra A, Medina I, Nguyen TT, Noe MC, Obach RS, O’Donnell JP, Penzien JB, Reilly UD, Schafer JR, Shen Y, Stone GG, Strelevitz TJ, Sun J, Tait-Kamradt A, Vaz ADN, Whipple DA, Widlicka DW, Wishka DG, Wolkowski JP, Flanagan ME. Discovery of Azetidinyl Ketolides for the Treatment of Susceptible and Multidrug Resistant Community-Acquired Respiratory Tract Infections. J Med Chem 2009; 52:7446-57. [DOI: 10.1021/jm900729s] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Thomas V. Magee
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Sharon L. Ripp
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Bryan Li
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Richard A. Buzon
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Lou Chupak
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Thomas J. Dougherty
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Steven M. Finegan
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Dennis Girard
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Anne E. Hagen
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Michael J. Falcone
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Kathleen A. Farley
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Karl Granskog
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Joel R. Hardink
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Michael D. Huband
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Barbara J. Kamicker
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Takushi Kaneko
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | | | - Jennifer L. Liras
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Andrea Marra
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Ivy Medina
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Thuy-Trinh Nguyen
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Mark C. Noe
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - R. Scott Obach
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - John P. O’Donnell
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Joseph B. Penzien
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Usa Datta Reilly
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - John R. Schafer
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Yue Shen
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Gregory G. Stone
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | | | - Jianmin Sun
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Amelia Tait-Kamradt
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Alfin D. N. Vaz
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - David A. Whipple
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Daniel W. Widlicka
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Donn G. Wishka
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Joanna P. Wolkowski
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
| | - Mark E. Flanagan
- Pfizer Global Research & Development, Pfizer, Inc., Groton, Connecticut 06340
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19
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Genetic elements responsible for erythromycin resistance in streptococci. Antimicrob Agents Chemother 2008; 53:343-53. [PMID: 19001115 DOI: 10.1128/aac.00781-08] [Citation(s) in RCA: 118] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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20
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Liu ZQ, Zheng PY, Yang PC. Efflux pump gene hefA of Helicobacter pylori plays an important role in multidrug resistance. World J Gastroenterol 2008; 14:5217-22. [PMID: 18777600 PMCID: PMC2744013 DOI: 10.3748/wjg.14.5217] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To determine whether efflux systems contribute to multidrug resistance of H pylori.
METHODS: A chloramphenicol-induced multidrug resistance model of six susceptible H pylori strains (5 isolates and H pylori NCTC11637) was developed. Multidrug-resistant (MDR) strains were selected and the minimal inhibitory concentration (MIC) of erythromycin, metronidazole, penicillin G, tetracycline, and ciprofloxacin in multidrug resistant strains and their parent strains was determined by agar dilution tests. The level of mRNA expression of hefA was assessed by fluorescence real-time quantitative PCR. A H pylori LZ1026 knockout mutant (ΔH pylori LZ1026) for (putative) efflux protein was constructed by inserting the kanamycin resistance cassette from pEGFP-N2 into hefA, and its susceptibility profiles to 10 antibiotics were evaluated.
RESULTS: The MIC of six multidrug-resistant strains (including 5 clinical isolates and H pylori NCTC11637) increased significantly (≥ 4-fold) compared with their parent strains. The expression level of hefA gene was significantly higher in the MDR strains than in their parent strains (P = 0.033). A H pylori LZ1026 mutant was successfully constructed and the ΔH pylori LZ1026 was more susceptible to four of the 10 antibiotics. All the 20 strains displayed transcripts for hefA that confirmed the in vitro expression of these genes.
CONCLUSION: The efflux pump gene hefA plays an important role in multidrug resistance of H pylori.
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21
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Liu ZQ, Zheng PY. Important role of efflux pump gene hefA in multidrug resistance of Helicobacter pylori. Shijie Huaren Xiaohua Zazhi 2008; 16:1751-1756. [DOI: 10.11569/wcjd.v16.i16.1751] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To determine whether efflux systems contribute to multidrug resistance(MDR) in Helicobacter pylori (H. pylori).
METHODS: A chloramphenicol-induced MDR model ex vivo was developed in six susceptible H. pylori strains (5 isolates and H. pylori NCTC11637). The minimal inhibitory concentrations (MICs) of erythromycin, metronidazole, penicillin G, tetracycline and ciprofloxacin were determined using agar dilution tests and MDR strains were selected accordingly. The mRNA expression level of hefA was estimated using fluorescence real-time quantitative PCR. A H. pylori LZ1026 knockout mutant (△HpLZ1026) for (putative) efflux protein was constructed through insertion of the Kanamycin resistance cassette from pEGFP-N2 into hefA, and its susceptibility profiles to 10 antibiotics were estimated. Expressions of hefA and hefC genes were detected using PCR in 20 clinically isolated H. pylori strains.
RESULTS: There was similar multidrug-resistance in chloramphenicol-induced screened multidrug-resistant (MDR) strains. Expression level of hefA gene in the 6 MDR strains was significantly higher compared with drug-sensitive strains (5.8466 ± 2.9370 vs 2.6356 ± 1.7245, P = 0.033). △HpLZ1026 was constructed successfully and its sensitivity to four of ten antibiotics was significantly increased. In all the 20 isolated strains, hefA and hefC genes were detected while strains of hefABC gene depletion were not found.
CONCLUSION: Efflux pump gene hefA plays an important role in multidrug resistance of H. pylori in vivo. The hefABC gene exists universally in H. pylori, which plays an essential role in mechanism underlying multidrug resistance.
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22
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Opatowski L, Temime L, Varon E, Leclercq R, Leclerc R, Drugeon H, Boëlle PY, Guillemot D. Antibiotic innovation may contribute to slowing the dissemination of multiresistant Streptococcus pneumoniae: the example of ketolides. PLoS One 2008; 3:e2089. [PMID: 18461139 PMCID: PMC2330086 DOI: 10.1371/journal.pone.0002089] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2007] [Accepted: 03/24/2008] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Despite increasingly frequent bacterial resistance to antibiotics, antibacterial innovation is rare. Ketolides constitute one of the very few new antibiotic classes active against Streptococcus pneumoniae developed during the last 25 years. Their mechanism of action resembles that of macrolides, but they are unaffected by common resistance mechanisms. However, cross-resistance to ketolides has been observed in some macrolide-resistant strains. We examined how new antibiotic exposure may affect overall pneumococcal resistance patterns in the population. The aims of this study were to assess the potential dissemination of newly emerged resistances and to control the selection of strains already multiresistant to existing antimicrobials. METHODOLOGY/PRINCIPAL FINDINGS We developed an age-structured population model for S. pneumoniae transmission in a human community exposed to heptavalent vaccine, and beta-lactams, macrolides and ketolides. The dynamics of intra-individual selection of resistant strains under antibiotic exposure and interindividual transmission were simulated, with antibiotic-specific resistance mechanisms defining the path to co-resistances and cross-resistances, and parameters concerning the French situation. Results of this simulation study suggest that new antibiotic consumption could markedly slow the diffusion of multiresistant strains. Wider use was associated with slower progression of multiresistance. When ketolides were prescribed to all ages, resistance to them reached 10% after >15 years, while it took >40 years when they were prescribed only to adults. In the scenario according to which new antibiotics totally replaced former antimicrobials, the beta-lactam resistance rate was limited at 70%. CONCLUSIONS In a context of widespread vaccination and rational use of antibiotics, innovative antibiotic, prescribed to all age groups, may have an added impact on multiresistant-strain dissemination in the population.
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Affiliation(s)
- Lulla Opatowski
- Unité de Pharmacoépidémiologie et Maladies Infectieuses, Institut Pasteur, Paris, France.
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23
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Del Grosso M, Camilli R, Iannelli F, Pozzi G, Pantosti A. The mef(E)-carrying genetic element (mega) of Streptococcus pneumoniae: insertion sites and association with other genetic elements. Antimicrob Agents Chemother 2006; 50:3361-6. [PMID: 17005818 PMCID: PMC1610078 DOI: 10.1128/aac.00277-06] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The structure of the macrolide efflux genetic assembly (mega) element, its genomic locations, and its association with other resistance determinants and genetic elements were investigated in 16 Streptococcus pneumoniae isolates carrying mef(E), of which 1 isolate also carried tet(M) and 4 isolates also carried tet(M) and erm(B). All isolates carried a mega element of similar size and structure that included the operon mef(E)-msr(D) encoding the efflux transport system. Among tetracycline-susceptible isolates, six different integration sites were identified, five of which were recognized inside open reading frames present in the R6 genome. In the five isolates also carrying tet(M), mega was inserted in different genetic contexts. In one isolate, it was part of previously described Tn916-like element Tn2009. In another isolate, mega was inserted in a transposon similar to Tn2009 that also included an erm(B) element. This new composite transposon was designated Tn2010. Neither Tn2009 nor Tn2010 could be transferred by conjugation to pneumococcal or enterococcal recipients. In the three isolates in which mega was not physically linked with tet(M), this gene was associated with erm(B) in transposon Tn3872, a Tn916-like element. Homologies between the chromosomal insertions of these composite transposons and sequences of multidrug-resistant pneumococcal genomes in the databases indicate the presence of preferential sites for the integration of composite Tn916-like elements carrying multiple resistance determinants in S. pneumoniae.
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Affiliation(s)
- Maria Del Grosso
- Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
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24
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Zhanel GG, Wang X, Nichol K, Nikulin A, Wierzbowski AK, Mulvey M, Hoban DJ. Molecular characterisation of Canadian paediatric multidrug-resistant Streptococcus pneumoniae from 1998-2004. Int J Antimicrob Agents 2006; 28:465-71. [PMID: 17049211 DOI: 10.1016/j.ijantimicag.2006.08.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2006] [Revised: 06/08/2006] [Accepted: 06/09/2006] [Indexed: 11/19/2022]
Abstract
Multidrug-resistant (MDR) Streptococcus pneumoniae (i.e. resistant to three different antimicrobial classes) is a global concern. The molecular epidemiology of MDR S. pneumoniae has not been characterised in Canadian paediatric isolates. Paediatric MDR S. pneumoniae were obtained from a national surveillance study. Susceptibility testing was performed by the methods of the Clinical and Laboratory Standards Institute. Phenotypic and genotypic relatedness were assessed by serotyping and pulsed-field gel electrophoresis (PFGE). Penicillin resistance was assessed with polymerase chain reaction (PCR) followed by DNA sequencing of penicillin-binding proteins (PBPs) 1A, 2B and 2X. Macrolide resistance was assessed by PCR-based detection of mef(E) and erm(B). PCR and sequencing of the dihydrofolate reductase (DHFR) gene was performed to assess resistance to trimethoprim/sulphamethoxazole (T/S). Seventy (98.6%) of 71 MDR paediatric isolates were concomitantly resistant to penicillin, erythromycin and T/S. Resistance genes mef(E) (66.2%) or erm(B) (22.5%) or both mef(E) and erm(B) (8.5%) were associated with macrolide resistance, and the prevalence of erm(B) increased significantly (P=0.0001) over time. Penicillin resistance was associated with amino acid substitutions in PBPs 1A, 2B and 2X. Resistance to T/S was associated with amino acid substitutions in the DHFR gene; in particular, Ile100-->Leu was detected in all isolates analysed. PFGE revealed three clusters of isolates that were genetically related and associated with specific serotypes (Taiwan(19F), Spain(23F), Spain(14) and France(9V)), suggesting clonal expansion as the primary means of paediatric MDR S. pneumoniae dissemination in Canada. The heptavalent pneumococcal vaccine Prevnar, currently approved in Canada for use in children < or =2 years of age, provided excellent coverage (90.2%) of paediatric MDR S. pneumoniae. In conclusion, paediatric MDR S. pneumoniae simultaneously resistant to penicillin, erythromycin and T/S are genetically similar and disseminating across Canada. Prevnar provides excellent coverage of paediatric MDR S. pneumoniae.
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Affiliation(s)
- George G Zhanel
- Department of Medical Microbiology, Faculty of Medicine, University of Manitoba, Manitoba, Canada.
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