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Kumar V, Yasmeen N, Pandey A, Ahmad Chaudhary A, Alawam AS, Ahmad Rudayni H, Islam A, Lakhawat SS, Sharma PK, Shahid M. Antibiotic adjuvants: synergistic tool to combat multi-drug resistant pathogens. Front Cell Infect Microbiol 2023; 13:1293633. [PMID: 38179424 PMCID: PMC10765517 DOI: 10.3389/fcimb.2023.1293633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 11/14/2023] [Indexed: 01/06/2024] Open
Abstract
The rise of multi-drug resistant (MDR) pathogens poses a significant challenge to the field of infectious disease treatment. To overcome this problem, novel strategies are being explored to enhance the effectiveness of antibiotics. Antibiotic adjuvants have emerged as a promising approach to combat MDR pathogens by acting synergistically with antibiotics. This review focuses on the role of antibiotic adjuvants as a synergistic tool in the fight against MDR pathogens. Adjuvants refer to compounds or agents that enhance the activity of antibiotics, either by potentiating their effects or by targeting the mechanisms of antibiotic resistance. The utilization of antibiotic adjuvants offers several advantages. Firstly, they can restore the effectiveness of existing antibiotics against resistant strains. Adjuvants can inhibit the mechanisms that confer resistance, making the pathogens susceptible to the action of antibiotics. Secondly, adjuvants can enhance the activity of antibiotics by improving their penetration into bacterial cells, increasing their stability, or inhibiting efflux pumps that expel antibiotics from bacterial cells. Various types of antibiotic adjuvants have been investigated, including efflux pump inhibitors, resistance-modifying agents, and compounds that disrupt bacterial biofilms. These adjuvants can act synergistically with antibiotics, resulting in increased antibacterial activity and overcoming resistance mechanisms. In conclusion, antibiotic adjuvants have the potential to revolutionize the treatment of MDR pathogens. By enhancing the efficacy of antibiotics, adjuvants offer a promising strategy to combat the growing threat of antibiotic resistance. Further research and development in this field are crucial to harness the full potential of antibiotic adjuvants and bring them closer to clinical application.
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Affiliation(s)
- Vikram Kumar
- Amity Institute of Biotechnology, Amity University Rajasthan, Jaipur, Rajasthan, India
- Amity Institute of Pharmacy, Amity University Rajasthan, Jaipur, Rajasthan, India
| | - Nusrath Yasmeen
- Amity Institute of Biotechnology, Amity University Rajasthan, Jaipur, Rajasthan, India
| | - Aishwarya Pandey
- INRS, Eau Terre Environnement Research Centre, Québec, QC, Canada
| | - Anis Ahmad Chaudhary
- Department of Biology, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh, Saudi Arabia
| | - Abdullah S. Alawam
- Department of Biology, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh, Saudi Arabia
| | - Hassan Ahmad Rudayni
- Department of Biology, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh, Saudi Arabia
| | - Asimul Islam
- Center for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi, India
| | - Sudarshan S. Lakhawat
- Amity Institute of Biotechnology, Amity University Rajasthan, Jaipur, Rajasthan, India
| | - Pushpender K. Sharma
- Amity Institute of Biotechnology, Amity University Rajasthan, Jaipur, Rajasthan, India
| | - Mohammad Shahid
- Department of Basic Medical Sciences, College of Medicine, Prince Sattam bin Abdulaziz University, Al-Kharj, Saudi Arabia
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Kassinger SJ, van Hoek ML. Genetic Determinants of Antibiotic Resistance in Francisella. Front Microbiol 2021; 12:644855. [PMID: 34054749 PMCID: PMC8149597 DOI: 10.3389/fmicb.2021.644855] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 03/25/2021] [Indexed: 12/21/2022] Open
Abstract
Tularemia, caused by Francisella tularensis, is endemic to the northern hemisphere. This zoonotic organism has historically been developed into a biological weapon. For this Tier 1, Category A select agent, it is important to expand our understanding of its mechanisms of antibiotic resistance (AMR). Francisella is unlike many Gram-negative organisms in that it does not have significant plasmid mobility, and does not express AMR mechanisms on plasmids; thus plasmid-mediated resistance does not occur naturally. It is possible to artificially introduce plasmids with AMR markers for cloning and gene expression purposes. In this review, we survey both the experimental research on AMR in Francisella and bioinformatic databases which contain genomic and proteomic data. We explore both the genetic determinants of intrinsic AMR and naturally acquired or engineered antimicrobial resistance as well as phenotypic resistance in Francisella. Herein we survey resistance to beta-lactams, monobactams, carbapenems, aminoglycosides, tetracycline, polymyxins, macrolides, rifampin, fosmidomycin, and fluoroquinolones. We also highlight research about the phenotypic AMR difference between planktonic and biofilm Francisella. We discuss newly developed methods of testing antibiotics against Francisella which involve the intracellular nature of Francisella infection and may better reflect the eventual clinical outcomes for new antibiotic compounds. Understanding the genetically encoded determinants of AMR in Francisella is key to optimizing the treatment of patients and potentially developing new antimicrobials for this dangerous intracellular pathogen.
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Affiliation(s)
| | - Monique L. van Hoek
- School of Systems Biology, George Mason University, Manassas, VA, United States
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3
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Abstract
Antibiotic resistance is mediated through several distinct mechanisms, most of which are relatively well understood and the clinical importance of which has long been recognized. Until very recently, neither of these statements was readily applicable to the class of resistance mechanism known as target protection, a phenomenon whereby a resistance protein physically associates with an antibiotic target to rescue it from antibiotic-mediated inhibition. In this Review, we summarize recent progress in understanding the nature and importance of target protection. In particular, we describe the molecular basis of the known target protection systems, emphasizing that target protection does not involve a single, uniform mechanism but is instead brought about in several mechanistically distinct ways.
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4
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de Alcântara Rodrigues I, Ferrari RG, Panzenhagen PHN, Mano SB, Conte-Junior CA. Antimicrobial resistance genes in bacteria from animal-based foods. ADVANCES IN APPLIED MICROBIOLOGY 2020; 112:143-183. [PMID: 32762867 DOI: 10.1016/bs.aambs.2020.03.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Antimicrobial resistance is a worldwide public health threat. Farm animals are important sources of bacteria containing antimicrobial resistance genes (ARGs). Although the use of antimicrobials in aquaculture and livestock has been reduced in several countries, these compounds are still routinely applied in animal production, and contribute to ARGs emergence and spread among bacteria. ARGs are transmitted to humans mainly through the consumption of products of animal origin (PAO). Bacteria can present intrinsic resistance, and once antimicrobials are administered, this resistance may be selected and multiply. The exchange of genetic material is another mechanism used by bacteria to acquire resistance. Some of the main ARGs found in bacteria present in PAO are the bla, mcr-1, cfr and tet genes, which are directly associated to antibiotic resistance in the human clinic.
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Affiliation(s)
- Isadora de Alcântara Rodrigues
- Molecular and Analytical Laboratory Center, Department of Food Technology, Faculty of Veterinary, Universidade Federal Fluminense, Niterói, Brazil
| | - Rafaela Gomes Ferrari
- Chemistry Institute, Food Science Program, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
| | | | - Sergio Borges Mano
- Molecular and Analytical Laboratory Center, Department of Food Technology, Faculty of Veterinary, Universidade Federal Fluminense, Niterói, Brazil
| | - Carlos Adam Conte-Junior
- Molecular and Analytical Laboratory Center, Department of Food Technology, Faculty of Veterinary, Universidade Federal Fluminense, Niterói, Brazil; Chemistry Institute, Food Science Program, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; National Institute of Health Quality Control, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
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5
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High Levels of Intrinsic Tetracycline Resistance in Mycobacterium abscessus Are Conferred by a Tetracycline-Modifying Monooxygenase. Antimicrob Agents Chemother 2018; 62:AAC.00119-18. [PMID: 29632012 DOI: 10.1128/aac.00119-18] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 03/27/2018] [Indexed: 11/20/2022] Open
Abstract
Tetracyclines have been one of the most successful classes of antibiotics. However, its extensive use has led to the emergence of widespread drug resistance, resulting in discontinuation of use against several bacterial infections. Prominent resistance mechanisms include drug efflux and the use of ribosome protection proteins. Infrequently, tetracyclines can be inactivated by the TetX class of enzymes, also referred to as tetracycline destructases. Low levels of tolerance to tetracycline in Mycobacterium smegmatis and Mycobacterium tuberculosis have been previously attributed to the WhiB7-dependent TetV/Tap efflux pump. However, Mycobacterium abscessus is ∼500-fold more resistant to tetracycline than M. smegmatis and M. tuberculosis In this report, we show that this high level of resistance to tetracycline and doxycycline in M. abscessus is conferred by a WhiB7-independent tetracycline-inactivating monooxygenase, MabTetX (MAB_1496c). The presence of sublethal doses of tetracycline and doxycycline results in a >200-fold induction of MabTetX, and an isogenic deletion strain is highly sensitive to both antibiotics. Further, purified MabTetX can rapidly monooxygenate both antibiotics. We also demonstrate that expression of MabTetX is repressed by MabTetRx, by binding to an inverted repeat sequence upstream of MabTetRx; the presence of either antibiotic relieves this repression. Moreover, anhydrotetracycline (ATc) can effectively inhibit MabTetX activity in vitro and decreases the MICs of both tetracycline and doxycycline in vivo Finally, we show that tigecycline, a glycylcycline tetracycline, not only is a poor substrate of MabTetX but also is incapable of inducing the expression of MabTetX. This is therefore the first demonstration of a tetracycline-inactivating enzyme in mycobacteria. It (i) elucidates the mechanism of tetracycline resistance in M. abscessus, (ii) demonstrates the use of an inhibitor that can potentially reclaim the use of tetracycline and doxycycline, and (iii) identifies two sequential bottlenecks-MabTetX and MabTetRx-for acquiring resistance to tigecycline, thereby reiterating its use against M. abscessus.
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Albert MJ, Udo E, Jose BT, Haridas S, Rotimi VO. Tetracycline Resistance Is Frequent AmongCampylobacter jejuniIsolates from Kuwait. Microb Drug Resist 2009; 15:115-20. [DOI: 10.1089/mdr.2009.0892] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- M. John Albert
- Department of Microbiology, Faculty of Medicine, Kuwait University, Safat, Kuwait
| | - Edet Udo
- Department of Microbiology, Faculty of Medicine, Kuwait University, Safat, Kuwait
| | - Berneesh T. Jose
- Department of Microbiology, Faculty of Medicine, Kuwait University, Safat, Kuwait
| | - Shilpa Haridas
- Department of Microbiology, Faculty of Medicine, Kuwait University, Safat, Kuwait
| | - Vincent O. Rotimi
- Department of Microbiology, Faculty of Medicine, Kuwait University, Safat, Kuwait
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7
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Guglielmetti E, Korhonen JM, Heikkinen J, Morelli L, von Wright A. Transfer of plasmid-mediated resistance to tetracycline in pathogenic bacteria from fish and aquaculture environments. FEMS Microbiol Lett 2009; 293:28-34. [DOI: 10.1111/j.1574-6968.2009.01512.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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8
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Thakor NS, Wilson KS, Scott PG, Taylor DE. An improved procedure for expression and purification of ribosomal protection protein Tet(O) for high-resolution structural studies. Protein Expr Purif 2007; 55:388-94. [PMID: 17537646 DOI: 10.1016/j.pep.2007.04.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Revised: 04/19/2007] [Accepted: 04/20/2007] [Indexed: 11/21/2022]
Abstract
Tetracycline (Tc) is a broad spectrum antibiotic that binds to the A site of the bacterial ribosome inhibiting delivery of aminoacyl-tRNA to the A site for productive protein biosynthesis. Tet(O) is in a class of the ribosomal protection proteins (RPPs) found in many pathogenic bacteria, that dislodges Tc from the A site of 70S ribosome to restore polypeptide elongation and confer Tc resistance to the bacteria. Considerable difficulty has been encountered in overexpressing and purifying Tet(O) from various Escherichia coli strains using lambdaPI, tac or T7 promoters. Here we report molecular cloning, overexpression of His-tagged Tet(O) in E. coli, an improved purification procedure and initial biochemical and biophysical characterization of His-tagged Tet(O).
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Affiliation(s)
- Nehal S Thakor
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alta., Canada T6G 2H7
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Halbert LW, Kaneene JB, Linz J, Mansfield LS, Wilson D, Ruegg PL, Warnick LD, Wells SJ, Fossler CP, Campbell AM, Geiger-Zwald AM. Genetic mechanisms contributing to reduced tetracycline susceptibility of Campylobacter isolated from organic and conventional dairy farms in the midwestern and northeastern United States. J Food Prot 2006; 69:482-8. [PMID: 16541675 DOI: 10.4315/0362-028x-69.3.482] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Campylobacter is one of the most common causes of gastroenteritis and can be acquired through contact with farm animals or the consumption of raw milk. Because of concerns over the role of food-producing animals in the dissemination of antimicrobial resistance to humans, we evaluated the prevalence of antimicrobial resistance in Campylobacter isolates from dairy farms and the genetic mechanism conferring the observed resistance. Evaluation of antimicrobial resistance was completed on 912 isolates from conventional and 304 isolates from organic dairy farms to eight drugs (azithromycin, chloramphenicol, ciprofloxacin, clindamycin, erythromycin, gentamicin, nalidixic acid, and tetracycline) with microbroth dilution. Resistance to seven of eight drugs was very low and did not differ by farm type. However, tetracycline resistance was common in Campylobacter isolated from both organic and conventional dairy farms, with 48 and 58% of isolates affected, respectively. By multiplex PCR, we determined that tetracycline resistance was highly associated with the carriage of tetO in Campylobacter isolates (X2 = 124, P < 0.01, kappa = 0.86).
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Affiliation(s)
- Lisa W Halbert
- Population Medicine Center, Michigan State University, East Lansing, Michigan 48824, USA
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Jeannot K, Sobel ML, El Garch F, Poole K, Plésiat P. Induction of the MexXY efflux pump in Pseudomonas aeruginosa is dependent on drug-ribosome interaction. J Bacteriol 2005; 187:5341-6. [PMID: 16030228 PMCID: PMC1196038 DOI: 10.1128/jb.187.15.5341-5346.2005] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
MexXY is an inducible efflux system that contributes to the natural resistance of Pseudomonas aeruginosa to antibiotics. Experiments involving real-time PCR after reverse transcription in reference strain PAO1 showed concentration-dependent induction of gene mexY by various ribosome inhibitors (e.g., chloramphenicol, tetracycline, macrolides, and aminoglycosides) but not by antibiotics acting on other cellular targets (e.g., beta-lactams, fluoroquinolones). Confirming a functional link between the efflux system and the translational machinery, ribosome protection by plasmid-encoded proteins TetO and ErmBP increased the resistance of a DeltamexAB-oprM mutant of PAO1 to tetracycline and erythromycin, respectively, as well as the concentrations of both drugs required to induce mexY. Furthermore, spontaneous mutations resulting in specific resistance to dihydrostreptomycin or spectinomycin also raised the minimal drug concentration for mexXY induction in strain PAO1. While strongly upregulated in a PAO1 mutant defective in gene mexZ (which codes for a putative repressor of operon mexXY), gene mexY remained inducible by agents such as tetracycline, chloramphenicol, and spectinomycin, suggesting additional regulatory loci for mexXY. Altogether, these data demonstrate physiological interplays between MexXY and the ribosome and are suggestive of an alternative function for MexXY beyond antibiotic efflux.
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Affiliation(s)
- Katy Jeannot
- Laboratoire de Bactériologie, Hôpital Jean Minjoz, 25030 Besançon Cedex, France
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11
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Moore IF, Hughes DW, Wright GD. Tigecycline Is Modified by the Flavin-Dependent Monooxygenase TetX. Biochemistry 2005; 44:11829-35. [PMID: 16128584 DOI: 10.1021/bi0506066] [Citation(s) in RCA: 138] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The clinical use of tetracycline antibiotics has decreased due to the emergence of efflux and ribosomal protection-based resistance mechanisms. Currently in phase III clinical trials, the glycylcycline derivative tigecycline (GAR-936) containing a 9-tert-butylglycylamido group is part of a new generation of tetracycline antibiotics developed during the 1990s. Tigecycline displays a broad spectrum of antibacterial activity and circumvents the efflux and ribosomal protection resistance mechanisms. The TetX protein is a flavin-dependent monooxygenase that modifies first and second generation tetracyclines and requires NADPH, Mg(2+), and O(2) for activity. We report that tigecycline is a substrate for TetX and that bacterial strains containing the tet(X) gene are resistant to tigecycline. The resistance is due to the modification of tigecycline by TetX to form 11a-hydroxytigecycline, which we have shown has a weakened ability to inhibit protein translation compared with tigecycline. We have explored the basis of this decreased ability to block translation and found that hydroxylation occurs in the region of the molecule important for coordinating magnesium. 11a-Hydroxytigecycline forms a weaker complex with magnesium than tigecycline; the crystal structure of tetracycline in complex with the ribosome has shown that magnesium coordination is critical for binding tetracycline. Although tet(X) has not been isolated from any clinically resistant strains, our report demonstrates the first enzymatic resistance mechanism to tigecycline and provides an alert for the surveillance of resistant strains that may contain tet(X).
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Affiliation(s)
- Ian F Moore
- Antimicrobial Research Centre, Department of Biochemistry and Biomedical Sciences, McMaster University, 1200 Main Street West, Hamilton, Ontario, L8N 3Z5, Canada
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12
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Druzina Z, Cooperman BS. Photolabile anticodon stem-loop analogs of tRNAPhe as probes of ribosomal structure and structural fluctuation at the decoding center. RNA (NEW YORK, N.Y.) 2004; 10:1550-62. [PMID: 15337844 PMCID: PMC1370642 DOI: 10.1261/rna.7930804] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2004] [Accepted: 06/28/2004] [Indexed: 05/18/2023]
Abstract
With the recent availability of high-resolution structures of bacterial ribosomes, studies of ribosome-catalyzed protein biosynthesis are now focusing on the nature of conformational changes that occur as the ribosome exerts its complex catalytic function. Photocrosslinking can be relevant for this purpose by providing clues to ribosomal structural fluctuations and dynamics. Here we describe crosslinking experiments on 70S ribosomes using two photolabile anticodon stem-loop derivatives of Escherichia coli tRNAPhe carrying a 4-thiouridine in either position 33 or 37 and denoted Ph-ASLs. One or both of these Ph-ASLs bind to the tRNA A-, P-, and E-sites on the ribosome, with both binding to and photocrosslinking from the E-site showing strong dependence on the presence of a tRNA in the P-site. Both Ph-ASLs crosslink to the extreme 3'-end of 16S rRNA from both the P- and E-sites, providing direct confirmatory evidence in solution for the folding back of the 3'-end toward the decoding region. This suggests that the 3'-end of 16S rRNA may act as a switch in controlling mRNA access to the decoding center, a phenomenon of potential relevance for the translation of leaderless mRNA. E-site bound Ph-ASLs also form photocrosslinks to nucleotides 1395-1398, 1399-1400, and 1491-1494 at the top of helix 44 of 16S rRNA, indicating movement of the decoding center from a position between the A- and P-sites seen in the crystal structure to one neighboring the E-site.
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MESH Headings
- Anti-Bacterial Agents/pharmacology
- Anticodon/genetics
- Base Sequence
- Binding Sites
- Cross-Linking Reagents
- Escherichia coli/genetics
- Escherichia coli/metabolism
- Models, Molecular
- Nucleic Acid Conformation
- Photochemistry
- RNA, Bacterial/chemistry
- RNA, Bacterial/genetics
- RNA, Bacterial/metabolism
- RNA, Ribosomal, 16S/chemistry
- RNA, Ribosomal, 16S/genetics
- RNA, Ribosomal, 16S/metabolism
- RNA, Transfer, Phe/chemistry
- RNA, Transfer, Phe/genetics
- RNA, Transfer, Phe/metabolism
- Ribosomes/chemistry
- Ribosomes/metabolism
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Affiliation(s)
- Zhanna Druzina
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323, USA
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13
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Connell SR, Trieber CA, Dinos GP, Einfeldt E, Taylor DE, Nierhaus KH. Mechanism of Tet(O)-mediated tetracycline resistance. EMBO J 2003; 22:945-53. [PMID: 12574130 PMCID: PMC145453 DOI: 10.1093/emboj/cdg093] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2002] [Revised: 12/17/2002] [Accepted: 12/23/2002] [Indexed: 11/14/2022] Open
Abstract
Tet(O) is an elongation factor-like protein which confers resistance to the protein synthesis inhibitor tetracycline by promoting the release of the drug from its inhibitory site on the ribosome. Here we investigated the interaction of Tet(O) with the elongating ribosome and show, using dimethyl sulfate (DMS) probing and binding assays, that it interacts preferentially with the post-translocational ribosome. Furthermore, using an XTP-dependent mutant of Tet(O), we demonstrated that Tet(O) induces conformational rearrangements within the ribosome which can be detected by EF-Tu, and manifested as a stimulation in the GTPase activity of this elongation factor. As such, these conformational changes probably involve the ribosomal GTPase-associated center and, accordingly, Tet(O) alters the DMS modification pattern of the L11 region. Additionally, tetracycline binding is associated with an E(a) of 58 kJ/mol. These results suggest a model where both Tet(O) and tetracycline induce a conformational change in functionally opposite directions and the Tet(O)-induced conformation persists after it has left the ribosome; this prevents rebinding of the drug while allowing productive A-site occupation by a ternary complex in the presence of tetracycline.
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Affiliation(s)
- Sean R. Connell
- Department of Medical Microbiology and Immunology, and Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2H7, Canada, Max-Planck-Institut für Molekulare Genetik, Ihnestrasse 73, D-14195 Berlin, Germany and Laboratory of Biochemistry, School of Medicine, University of Patras, Greece Corresponding author e-mail:
| | - Catharine A. Trieber
- Department of Medical Microbiology and Immunology, and Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2H7, Canada, Max-Planck-Institut für Molekulare Genetik, Ihnestrasse 73, D-14195 Berlin, Germany and Laboratory of Biochemistry, School of Medicine, University of Patras, Greece Corresponding author e-mail:
| | - George P. Dinos
- Department of Medical Microbiology and Immunology, and Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2H7, Canada, Max-Planck-Institut für Molekulare Genetik, Ihnestrasse 73, D-14195 Berlin, Germany and Laboratory of Biochemistry, School of Medicine, University of Patras, Greece Corresponding author e-mail:
| | - Edda Einfeldt
- Department of Medical Microbiology and Immunology, and Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2H7, Canada, Max-Planck-Institut für Molekulare Genetik, Ihnestrasse 73, D-14195 Berlin, Germany and Laboratory of Biochemistry, School of Medicine, University of Patras, Greece Corresponding author e-mail:
| | - Diane E. Taylor
- Department of Medical Microbiology and Immunology, and Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2H7, Canada, Max-Planck-Institut für Molekulare Genetik, Ihnestrasse 73, D-14195 Berlin, Germany and Laboratory of Biochemistry, School of Medicine, University of Patras, Greece Corresponding author e-mail:
| | - Knud H. Nierhaus
- Department of Medical Microbiology and Immunology, and Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2H7, Canada, Max-Planck-Institut für Molekulare Genetik, Ihnestrasse 73, D-14195 Berlin, Germany and Laboratory of Biochemistry, School of Medicine, University of Patras, Greece Corresponding author e-mail:
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14
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Connell SR, Trieber CA, Stelzl U, Einfeldt E, Taylor DE, Nierhaus KH. The tetracycline resistance protein Tet(o) perturbs the conformation of the ribosomal decoding centre. Mol Microbiol 2002; 45:1463-72. [PMID: 12354218 DOI: 10.1046/j.1365-2958.2002.03115.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Tet(o) is an elongation factor-like protein found in clinical isolates of Campylobacter jejuni that confers resistance to the protein-synthesis inhibitor tetracycline. Tet(o) interacts with the 70S ribosome and promotes the release of bound tetracycline, however, as shown here, it does not form the same functional interaction with the 30S subunit. Chemical probing demonstrates that Tet(o) changes the reactivity of the 16S rRNA to dimethyl sulphate (DMS). These changes cluster within the decoding site, where C1214 is protected and A1408 is enhanced to DMS reactivity. C1214 is close to, but does not overlap, the primary tetracycline-binding site, whereas A1408 is in a region distinct from the Tet(o) binding site visualized by cryo-EM, indicating that Tet(o) induces long-range rearrangements that may mediate tetracycline resistance. Tetracycline enhances C1054 to DMS modification but this enhancement is inhibited in the presence of Tet(o) unlike the tetracycline-dependent protection of A892 which is unaffected by Tet(o). C1054 is part of the primary binding site of tetracycline and A892 is part of the secondary binding site. Therefore, the results for the first time demonstrate that the primary tetracycline binding site is correlated with tetracycline's inhibitory effect on protein synthesis.
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Affiliation(s)
- Sean R Connell
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada.
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15
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Chopra I, Roberts M. Tetracycline antibiotics: mode of action, applications, molecular biology, and epidemiology of bacterial resistance. Microbiol Mol Biol Rev 2001; 65:232-60 ; second page, table of contents. [PMID: 11381101 PMCID: PMC99026 DOI: 10.1128/mmbr.65.2.232-260.2001] [Citation(s) in RCA: 2450] [Impact Index Per Article: 106.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Tetracyclines were discovered in the 1940s and exhibited activity against a wide range of microorganisms including gram-positive and gram-negative bacteria, chlamydiae, mycoplasmas, rickettsiae, and protozoan parasites. They are inexpensive antibiotics, which have been used extensively in the prophlylaxis and therapy of human and animal infections and also at subtherapeutic levels in animal feed as growth promoters. The first tetracycline-resistant bacterium, Shigella dysenteriae, was isolated in 1953. Tetracycline resistance now occurs in an increasing number of pathogenic, opportunistic, and commensal bacteria. The presence of tetracycline-resistant pathogens limits the use of these agents in treatment of disease. Tetracycline resistance is often due to the acquisition of new genes, which code for energy-dependent efflux of tetracyclines or for a protein that protects bacterial ribosomes from the action of tetracyclines. Many of these genes are associated with mobile plasmids or transposons and can be distinguished from each other using molecular methods including DNA-DNA hybridization with oligonucleotide probes and DNA sequencing. A limited number of bacteria acquire resistance by mutations, which alter the permeability of the outer membrane porins and/or lipopolysaccharides in the outer membrane, change the regulation of innate efflux systems, or alter the 16S rRNA. New tetracycline derivatives are being examined, although their role in treatment is not clear. Changing the use of tetracyclines in human and animal health as well as in food production is needed if we are to continue to use this class of broad-spectrum antimicrobials through the present century.
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Affiliation(s)
- I Chopra
- Antimicrobial Research Centre and Division of Microbiology, School of Biochemistry & Molecular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
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16
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Chopra I, Roberts M. Tetracycline antibiotics: mode of action, applications, molecular biology, and epidemiology of bacterial resistance. Microbiol Mol Biol Rev 2001. [PMID: 11381101 DOI: 10.1016/s0022-3093(98)00783-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2023] Open
Abstract
Tetracyclines were discovered in the 1940s and exhibited activity against a wide range of microorganisms including gram-positive and gram-negative bacteria, chlamydiae, mycoplasmas, rickettsiae, and protozoan parasites. They are inexpensive antibiotics, which have been used extensively in the prophlylaxis and therapy of human and animal infections and also at subtherapeutic levels in animal feed as growth promoters. The first tetracycline-resistant bacterium, Shigella dysenteriae, was isolated in 1953. Tetracycline resistance now occurs in an increasing number of pathogenic, opportunistic, and commensal bacteria. The presence of tetracycline-resistant pathogens limits the use of these agents in treatment of disease. Tetracycline resistance is often due to the acquisition of new genes, which code for energy-dependent efflux of tetracyclines or for a protein that protects bacterial ribosomes from the action of tetracyclines. Many of these genes are associated with mobile plasmids or transposons and can be distinguished from each other using molecular methods including DNA-DNA hybridization with oligonucleotide probes and DNA sequencing. A limited number of bacteria acquire resistance by mutations, which alter the permeability of the outer membrane porins and/or lipopolysaccharides in the outer membrane, change the regulation of innate efflux systems, or alter the 16S rRNA. New tetracycline derivatives are being examined, although their role in treatment is not clear. Changing the use of tetracyclines in human and animal health as well as in food production is needed if we are to continue to use this class of broad-spectrum antimicrobials through the present century.
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Affiliation(s)
- I Chopra
- Antimicrobial Research Centre and Division of Microbiology, School of Biochemistry & Molecular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
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17
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Aminov RI, Garrigues-Jeanjean N, Mackie RI. Molecular ecology of tetracycline resistance: development and validation of primers for detection of tetracycline resistance genes encoding ribosomal protection proteins. Appl Environ Microbiol 2001; 67:22-32. [PMID: 11133424 PMCID: PMC92507 DOI: 10.1128/aem.67.1.22-32.2001] [Citation(s) in RCA: 467] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Phylogenetic analysis of tetracycline resistance genes encoding the ribosomal protection proteins (RPPs) revealed the monophyletic origin of these genes. The most deeply branching class, exemplified by tet and otrA, consisted of genes from the antibiotic-producing organisms Streptomyces rimosus and Streptomyces lividans. With a high degree of confidence, the corresponding genes of the other seven classes (Tet M, Tet S, Tet O, Tet W, Tet Q, Tet T, and TetB P) formed phylogenetically distinct separate clusters. Based on this phylogenetic analysis, a set of PCR primers for detection, retrieval, and sequence analysis of the corresponding gene fragments from a variety of bacterial and environmental sources was developed and characterized. A pair of degenerate primers targeted all tetracycline resistance genes encoding RPPs except otrA and tet, and seven other primer pairs were designed to target the specific classes. The primers were used to detect the circulation of these genes in the rumina of cows, in swine feed and feces, and in swine fecal streptococci. Classes Tet O and Tet W were found in the intestinal contents of both animals, while Tet M was confined to pigs and Tet Q was confined to the rumen. The tet(O) and tet(W) genes circulating in the microbiota of the rumen and the gastrointestinal tract of pigs were identical despite the differences in animal hosts and antibiotic use regimens. Swine fecal streptococci uniformly possessed the tet(O) gene, and 22% of them also carried tet(M). This population could be considered one of the main reservoirs of these two resistance genes in the pig gastrointestinal tract. All classes of RPPs except Tet T and TetB P were found in the commercial components of swine feed. This is the first demonstration of the applicability of molecular ecology techniques to estimation of the gene pool and the flux of antibiotic resistance genes in production animals.
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Affiliation(s)
- R I Aminov
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
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Brodersen DE, Clemons WM, Carter AP, Morgan-Warren RJ, Wimberly BT, Ramakrishnan V. The structural basis for the action of the antibiotics tetracycline, pactamycin, and hygromycin B on the 30S ribosomal subunit. Cell 2000; 103:1143-54. [PMID: 11163189 DOI: 10.1016/s0092-8674(00)00216-6] [Citation(s) in RCA: 604] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
We have used the recently determined atomic structure of the 30S ribosomal subunit to determine the structures of its complexes with the antibiotics tetracycline, pactamycin, and hygromycin B. The antibiotics bind to discrete sites on the 30S subunit in a manner consistent with much but not all biochemical data. For each of these antibiotics, interactions with the 30S subunit suggest a mechanism for its effects on ribosome function.
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Affiliation(s)
- D E Brodersen
- MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, United Kingdom
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19
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Charpentier E, Tuomanen E. Mechanisms of antibiotic resistance and tolerance in Streptococcus pneumoniae. Microbes Infect 2000; 2:1855-64. [PMID: 11165930 DOI: 10.1016/s1286-4579(00)01345-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Streptococcus pneumoniae is a major pathogen causing potentially life-threatening community-acquired diseases in both the developed and developing world. Since 1967, there has been a dramatic increase in the incidence of penicillin-resistant and multiply antibiotic-resistant pneumococci worldwide. Prevention of access of the antibiotic to the target, inactivation of the antibiotic and alteration of the target are mechanisms that S. pneumoniae has developed to resist antibiotics. Recent studies on antibiotic-tolerant pneumococcal mutants permitted development of a novel model for the control of bacterial cell death.
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Affiliation(s)
- E Charpentier
- Department of Molecular Pathogenesis, Skirball Institute of Biomolecular Medicine, New York, NY 10016, USA
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Bacon DJ, Alm RA, Burr DH, Hu L, Kopecko DJ, Ewing CP, Trust TJ, Guerry P. Involvement of a plasmid in virulence of Campylobacter jejuni 81-176. Infect Immun 2000; 68:4384-90. [PMID: 10899834 PMCID: PMC98329 DOI: 10.1128/iai.68.8.4384-4390.2000] [Citation(s) in RCA: 276] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Campylobacter jejuni strain 81-176 contains two, previously undescribed plasmids, each of which is approximately 35 kb in size. Although one of the plasmids, termed pTet, carries a tetO gene, conjugative transfer of tetracycline resistance to another strain of C. jejuni could not be demonstrated. Partial sequence analysis of the second plasmid, pVir, revealed the presence of four open reading frames which encode proteins with significant sequence similarity to Helicobacter pylori proteins, including one encoded by the cag pathogenicity island. All four of these plasmid-encoded proteins show some level of homology to components of type IV secretion systems. Mutation of one of these plasmid genes, comB3, reduced both adherence to and invasion of INT407 cells to approximately one-third that seen with wild-type strain 81-176. Mutation of comB3 also reduced the natural transformation frequency. A mutation in a second plasmid gene, a virB11 homolog, resulted in a 6-fold reduction in adherence and an 11-fold reduction in invasion compared to the wild type. The isogenic virB11 mutant of strain 81-176 also demonstrated significantly reduced virulence in the ferret diarrheal disease model. The virB11 homolog was detected on plasmids in 6 out of 58 fresh clinical isolates of C. jejuni, suggesting that plasmids are involved in the virulence of a subset of C. jejuni pathogens.
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Affiliation(s)
- D J Bacon
- Enteric Diseases Department, Naval Medical Research Center, Silver Spring, Maryland 20910, USA
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21
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Widdowson CA, Klugman KP. The molecular mechanisms of tetracycline resistance in the pneumococcus. Microb Drug Resist 2000; 4:79-84. [PMID: 9533730 DOI: 10.1089/mdr.1998.4.79] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Tetracycline resistance in the pneumococcus is a result of the acquisition of one of two resistance determinants, tet(M) or tet(O). These genes encode ribosomal protection proteins that have homology to the elongation factors G and Tu. Tet(M) and Tet(O) both have GTPase activity that appears to be important in the displacement of tetracycline from the ribosome. Modification of tRNA may also be important for tetracycline resistance. Transcription of tet(M) is thought to be regulated by transcriptional attenuation. Transcription of tet(O) is constitutive, however, upstream of the gene are sequences that also appear to be involved in transcriptional attenuation. tet(M) is transferred on the conjugative transposons, Tn1545 and Tn5151. It is not yet known whether tet(O) is transported on transposons or plasmids, or whether it is chromosomally integrated, in pneumococci.
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Affiliation(s)
- C A Widdowson
- South African Institute for Medical Research and the University of Witwatersrand, Department of Clinical Microbiology and Infectious Diseases, Johannesburg
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22
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Salam MA. Antimicrobial therapy for shigellosis: issues on antimicrobial resistance. JAPANESE JOURNAL OF MEDICAL SCIENCE & BIOLOGY 1999; 51 Suppl:S43-62. [PMID: 10211436 DOI: 10.7883/yoken1952.51.supplement1_s43] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- M A Salam
- International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh
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Trieber CA, Burkhardt N, Nierhaus KH, Taylor DE. Ribosomal protection from tetracycline mediated by Tet(O): Tet(O) interaction with ribosomes is GTP-dependent. Biol Chem 1998; 379:847-55. [PMID: 9705148 DOI: 10.1515/bchm.1998.379.7.847] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Tet(O) mediates tetracycline resistance by protecting the ribosome from inhibition. A recombinant Tet(O) protein with a histidine tag was purified and its activity in protein synthesis characterized. Tetracycline inhibited the rate of poly(Phe) synthesis, producing short peptide chains. Tet(O)-His was able to restore the elongation rate and processivity. 70S ribosomes bound tetracycline with high affinity. Tet(O)-His in the presence of GTP, but not GDP or GMP, reduced the affinity of the ribosomes for tetracycline. Non-hydrolyzable GTP analogs in the presence of the factor were also able to interfere with tetracycline binding. Ribosomes increased the affinity of Tet(O)-His for GTPgammaS. Tet(O), 70S ribosomes and GTPgammaS formed a complex that could be isolated by gel filtration. The GTP conformer is the active form of Tet(O) that interacts with the ribosome. GTP binding is necessary for Tet(O) activity.
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Affiliation(s)
- C A Trieber
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada
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Fujihira E, Kimura T, Yamaguchi A. Roles of acidic residues in the hydrophilic loop regions of metal-tetracycline/H+ antiporter Tet(K) of Staphylococcus aureus. FEBS Lett 1997; 419:211-4. [PMID: 9428636 DOI: 10.1016/s0014-5793(97)01457-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Three transmembrane glutamic acid residues play essential roles in the metal-tetracycline/H+ antiporter Tet(K) of Staphylococcus aureus [Fujihira et al., FEBS Lett. 391 (1996) 243-246]. In the putative hydrophilic loop region of the Tet(K) and Tet(L) proteins, six acidic residues are conserved. Asp74, Asp200, Asp318 and Glu381 are located on the putative cytoplasmic side, and Asp39 and Glu345 on the putative periplasmic side. These residues were replaced by a neutral amino acid residue or a charge-conserved one. In contrast to the transmembrane glutamic acid residues, the replacement of the two glutamic acid residues (Glu345 and Glu381) did not affect the tetracycline resistance level. Out of the other four aspartic acid residues, the only essential residue is Asp318, any replacement of which resulted in complete loss of the tetracycline resistance and transport activity. Asp318 is located in cytoplasmic loop 10-11 in the putative 14-transmembrane-segment topology of Tet(K). In the case of the tetracycline exporters of Gram-negative bacteria, the only essential acidic residue in the cytoplasmic loop region is located in loop 2-3 [Yamaguchi et al., Biochemistry 31 (1992) 8344-8348]. It may be a general role for tetracycline efflux proteins that three transmembrane and one cytoplasmic acidic residues are mandatory for the tetracycline transport function.
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Affiliation(s)
- E Fujihira
- Department of Cell Membrane Biology, Institute of Scientific and Industrial Research, Osaka University, Japan
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25
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Clermont D, Chesneau O, De Cespédès G, Horaud T. New tetracycline resistance determinants coding for ribosomal protection in streptococci and nucleotide sequence of tet(T) isolated from Streptococcus pyogenes A498. Antimicrob Agents Chemother 1997; 41:112-6. [PMID: 8980765 PMCID: PMC163670 DOI: 10.1128/aac.41.1.112] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
An approach based on PCR has been developed to identify new members of the tet gene family in streptococci resistant to tetracycline and minocycline. Degenerate primers, corresponding to portions of the conserved domains of the proteins Tet(M), Tet(O), TeTB(P), Tet(Q), and Tet(S), all specifying the tetracycline-minocycline resistance phenotype, were used to selectively amplify DNA fragments within the coding sequences. Nine streptococcal strains which do not carry the genes tet(M), tet(O), tetB(P), tet(Q), or tet(S) were investigated. Four of them gave no detectable PCR products. The five remaining strains each yielded a PCR product of 1.1 kbp. DNA hybridization experiments showed that these putative Tet determinants fell into four new hybridization classes, of which one, Tet T, was further analyzed. The gene tet(T) was isolated from Streptococcus pyogenes A498, and the nucleotide sequence that was necessary and sufficient for the expression of tetracycline resistance in Escherichia coli was determined. The deduced Tet(T) protein consists of 651 amino acids. The protein most closely related to Tet(T) was Tet(Q), which has 49% identical amino acid residues. A phylogenetic analysis revealed that Tet T represents a novel branching order among the Tet determinants so far described.
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Affiliation(s)
- D Clermont
- Laboratoire des Staphylocoques et des Streptocoques, Institut Pasteur, Paris, France
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26
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Roberts MC. Tetracycline resistance determinants: mechanisms of action, regulation of expression, genetic mobility, and distribution. FEMS Microbiol Rev 1996; 19:1-24. [PMID: 8916553 DOI: 10.1111/j.1574-6976.1996.tb00251.x] [Citation(s) in RCA: 345] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Tetracycline-resistant bacteria were first isolated in 1953 from Shigella dysenteriae, a bacterium which causes bacterial dysentery. Since then tetracycline-resistant bacterial have been found in increasing numbers of species and genera. This has resulted in reduced effectiveness of tetracycline therapy over time. Tetracycline resistance is normally due to the acquisition of new genes often associated with either a mobile plasmid or a transposon. These tetracycline resistance determinants are distinguishable both genetically and biochemically. Resistance is primarily due to either energy-dependent efflux of tetracycline or protection of the ribosomes from the action of tetracycline. Gram-negative tetracycline efflux proteins are linked to repressor proteins which in the absence of tetracycline block transcription of the repressor and structural efflux genes. In contrast, expression of the Gram-positive tetracycline efflux genes and some of the ribosomal protection genes appears to be regulated by attenuation of mRNA transcription. Specific tetracycline resistance genes have been identified in 32 Gram-negative and 22 Gram-positive genera. Tetracycline-resistant bacteria are found in pathogens, opportunistic and normal flora species. Tetracycline-resistant bacteria can be isolated from man, animals, food, and the environment. The nonpathogens in each of these ecosystems may play an important role as reservoirs for the antibiotic resistance genes. It is clear that if we are to reverse the trend toward increasingly antibiotic-resistant pathogenic bacteria we will need to change how antibiotics are used in both human and animal health and food production.
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Affiliation(s)
- M C Roberts
- Department of Pathobiology, School of Public Health and Community Medicine, University of Washington, Seattle 98195-7238, USA.
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Bergeron J, Ammirati M, Danley D, James L, Norcia M, Retsema J, Strick CA, Su WG, Sutcliffe J, Wondrack L. Glycylcyclines bind to the high-affinity tetracycline ribosomal binding site and evade Tet(M)- and Tet(O)-mediated ribosomal protection. Antimicrob Agents Chemother 1996; 40:2226-8. [PMID: 8878615 PMCID: PMC163507 DOI: 10.1128/aac.40.9.2226] [Citation(s) in RCA: 120] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
N,N-dimethylglycylamido (DMG) derivatives of 6-demethyl-6-deoxytetracycline and doxycycline bind 5-fold more effectively than tetracycline to the tetracycline high-affinity binding site on the Escherichia coli 70S ribosome, which correlates with a 10-fold increase in potency for inhibition of E. coli cell-free translation. The potencies of DMG-doxycycline and DMG-6-demethyl-6-deoxytetracycline were unaffected by the ribosomal tetracycline resistance factors Tet(M) and Tet(O) in cell-free translation assays and whole-cell bioassays with a conditional Tet(M)-producing E. coli strain.
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Affiliation(s)
- J Bergeron
- Central Research Division, Pfizer Inc., Groton, Connecticut 06340, USA
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28
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Fujihira E, Kimura T, Shiina Y, Yamaguchi A. Transmembrane glutamic acid residues play essential roles in the metal-tetracycline/H+ antiporter of Staphylococcus aureus. FEBS Lett 1996; 391:243-6. [PMID: 8764982 DOI: 10.1016/0014-5793(96)00743-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Three transmembrane aspartyl residues play essential roles in the transposon Tn10-encoded metal-tetracycline/H+ antiporter (Tet(B)) [Yamaguchi, A. et al. (1992) J. Biol. Chem. 267, 7490-7498]. The tetK gene-encoding tetracycline resistance protein (Tet(K)) of Staphylococcus aureus mediates metal-tetracycline/H+ antiport similarly to Tet(B); however, it has no transmembrane aspartyl residue. On the other hand, Tet(K) has three glutamyl residues, Glu-30, Glu-152 and Glu-397, in the putative transmembrane regions. In the present work, tet(K) gene was expressed in Escherichia coli and the transport activity was measured in everted membrane vesicles. When these glutamyl residues were replaced with Gln, the tetracycline transport activity was almost completely lost, indicating the important roles of these residues in Tet(K). In the case of Glu-397, even the charge-conserved mutation to Asp caused complete loss of the activity. On the other hand, the mutation of Glu-30 and Glu-152 to Asp resulted in significant retention of transport activity. These results are similar to those on the mutation of the three transmembrane aspartyl residues in Tet(B), indicating that the transmembrane glutamyl residues in Tet(K) play roles similar to those of the transmembrane aspartyl residues in Tet(B).
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Affiliation(s)
- E Fujihira
- Department of Cell Membrane Biology, Osaka University, Japan
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29
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Abstract
Tet(M) protein, which displays homology to elongation factor G (EF-G), interacts with the protein biosynthetic machinery to render this process resistant to tetracycline in vivo and in vitro. To clarify the basis of the resistance mechanism, the effects of Tet(M) on several reactions which occur during protein synthesis were examined. The mechanism of action of Tet(M) has been clarified by two observations. The protein relieves tetracycline inhibition of factor-dependent tRNA binding and dramatically reduces the affinity of ribosomes for tetracycline when GTP is present. This reduction in drug affinity appears to be due to a large increase in the rate of tetracycline dissociation. Addition of Tet(M) to ribosome-tetracycline complexes results in displacement of bound drug. And, while Tet(M) and EF-G GTPase activities are tetracycline resistant, the two proteins differ in their sensitivities to fusidic acid, with the latter activity inhibited by the drug. Furthermore, while Tet(M) protects translation from tetracycline inhibition in a defined system, it is unable to substitute for either EF-G or elongation factor Tu.
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Affiliation(s)
- V Burdett
- Department of Microbiology, Duke University Medical Center, Durham, North Carolina 27710, USA
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Brown BA, Wallace RJ, Onyi G. Activities of the glycylcyclines N,N-dimethylglycylamido-minocycline and N,N-dimethylglycylamido-6-demethyl-6-deoxytetracycline against Nocardia spp. and tetracycline-resistant isolates of rapidly growing mycobacteria. Antimicrob Agents Chemother 1996; 40:874-8. [PMID: 8849243 PMCID: PMC163222 DOI: 10.1128/aac.40.4.874] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Susceptibilities to the new semisynthetic tetracycline (Tet) compounds N,N-dimethylglycylamido-minocycline (DMG-MINO) and N,N-dimethylglycylamido-6-demethyl-6-deoxytetracycline (DMG-DMDOT) were compared with those to doxycycline, minocycline, and Tet for 198 Tet-resistant (Tetr) and 33 Tet-susceptible (Tets) clinical isolates of rapidly growing mycobacteria (RGM) including the Mycobacterium fortuitum group, Mycobacterium abscessus, Mycobacterium chelonae, and Mycobacterium mucogenicum and 68 isolates belonging to six taxa of Nocardia spp. All Tetr RGM were highly susceptible to the glycylcyclines. The MICs at which 50 and 90% of isolates are inhibited were < or = 0.125 and < or = 0.25 microgram/ml, respectively, for DMG-DMDOT and < or = 0.25 and 1 microgram/ml, respectively, for DMG-MINO. The MIC of DMG-DMDOT at which 50% of Tetr strains are inhibited was the same as that for Tets strains for each of the four taxa of RGM. The new agents were less active against Nocardia spp. MICs of DMG-DMDOT were comparable to those of minocycline except for the MICs for Nocardia brasiliensis sensu stricto, the new taxon Nocardia pseudobrasiliensis, and some isolates of Nocardia nova, against which they were four- to eightfold more active. The MICs of DMG-DMDOT were consistently lower than those of DMG-MINO for RGM. This class of drugs offers exciting therapeutic potential for RGM and for selected species of Nocardia.
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Affiliation(s)
- B A Brown
- Department of Microbiology, University of Texas Health Center, Tyler 75710, USA
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31
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Kolesnikov IV, Protasova NY, Gudkov AT. Tetracyclines induce changes in accessibility of ribosomal proteins to proteases. Biochimie 1996; 78:868-73. [PMID: 9116057 DOI: 10.1016/s0300-9084(97)84340-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Limited proteolysis was used to test the interaction of tetracyclines and some of their derivatives with ribosomes. Proteolysis of the free ribosomes was compared with that of the ligand-bound ribosomes. The interaction of different tetracyclines with ribosomes depends on their chemical structure and produces both a protective effect and an increased susceptibility to proteases of some ribosomal proteins in the 30S and 50S subparticles. Most of the proteins affected by tetracycline action are located on the head of the 30S and interface side of the 50S subunits. On the grounds of the obtained data one of the antibiotic-binding regions can be located near the ribosomal peptidyl transferase center. The effect of possible conformational changes induced by tetracyclines on the translation process is discussed.
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Affiliation(s)
- I V Kolesnikov
- Institute of Protein Research, Russian Academy of Sciences, Moscow Region, Russia
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32
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Taylor DE, Chau A. Tetracycline resistance mediated by ribosomal protection. Antimicrob Agents Chemother 1996; 40:1-5. [PMID: 8787868 PMCID: PMC163045 DOI: 10.1128/aac.40.1.1] [Citation(s) in RCA: 109] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Affiliation(s)
- D E Taylor
- Department of Medical Microbiology, University of Alberta, Edmonton, Canada.
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Taylor DE, Jerome LJ, Grewal J, Chang N. Tet(O), a protein that mediates ribosomal protection to tetracycline, binds, and hydrolyses GTP. Can J Microbiol 1995. [DOI: 10.1139/m95-134] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The tet(O) tetracycline resistance gene, originally cloned from Campylobacter jejuni, mediates resistance by ribosomal protection. Using partially purified Tet(O) protein of 68 000 Da whose identity was verified by ribosomal protection assays, amino terminal sequencing, and immunoblotting using an antibody raised against the deduced 15 amino acids at the carboxyl terminus of the Tet(O) protein, the Tet(O) protein was found to bind to [α-32P]GTP and [3H]GDP using a filter binding assay. [γ-32P]GTP hydrolysis by Tet(O) was also demonstrated and was found to be time dependent with more than 50% of the hydrolysis activity occurring within the first 5 min. The GTPase activity of Tet(O) appears to be ribosome dependent, suggesting that ribosomes act as an effector similar to other G proteins involved in signal transduction.Key words: ribosomes, tetracycline resistance, GTPase, protein synthesis.
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34
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Yamaguchi A, Shiina Y, Fujihira E, Sawai T, Noguchi N, Sasatsu M. The tetracycline efflux protein encoded by the tet(K) gene from Staphylococcus aureus is a metal-tetracycline/H+ antiporter. FEBS Lett 1995; 365:193-7. [PMID: 7781778 DOI: 10.1016/0014-5793(95)00455-i] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The tet(K) gene from Staphylococcus aureus was highly expressed in Escherichia coli by an alteration of its initiation codon from TTG to ATG and its ribosome-binding sequence from GAGG to GGAGG [Noguchi, N. et al. (1994) Biol. Pharm. Bull. 17, 352-355]. The inverted membrane vesicles prepared from the tet(K)-expressing cells showed respiration-dependent [3H]tetracycline transport comparable to the vesicles from the tet(B)-expressing cells. The affinity of Tet(K) vesicles to tetracycline was the same as that of Tet(B) vesicles, whereas the former Vmax value was about 60% of the latter one. Contrary to Tet(B) vesicles, Tet(K) vesicles showed no significant minocycline uptake, which was consistent with the low minocycline resistance of the Tet(K)-producing cells. The tetracycline transport mediated by Tet(K) vesicles was coupled with proton transport and the translocation of 60Co2+ ions as well as in Tet(B) vesicles. This observation indicates that the class K tetracycline resistance determinant from Gram-positive bacteria also encodes a metal-tetracycline/H+ antiporter that is functionally similar to that encoded by tet(B), although there is a considerable difference in the primary sequences and the putative topologies of these Tet proteins.
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Affiliation(s)
- A Yamaguchi
- Division of Microbial Chemistry, Faculty of Pharmaceutical Sciences, Chiba University, Japan
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35
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Allen NE. Biochemical mechanisms of resistance to non-cell wall antibacterial agents. PROGRESS IN MEDICINAL CHEMISTRY 1995; 32:157-238. [PMID: 8577918 DOI: 10.1016/s0079-6468(08)70454-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- N E Allen
- Infectious Disease Research, Eli Lilly and Company, Indianapolis, IN 46285, USA
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36
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Abstract
Resistance to tetracycline is generally due either to energy-dependent efflux of tetracycline or to protection of the bacterial ribosomes from the action of tetracycline. The genes that encode this resistance are normally acquired via transferable plasmids and/or transposons. Tet determinants have been found in a wide range of Gram-positive and Gram-negative bacteria and have reduced the effectiveness of therapy with tetracycline.
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Affiliation(s)
- M C Roberts
- Dept of Pathobiology, School of Public Health and Community Medicine, University of Washington, Seattle 98195
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37
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Sloan J, McMurry LM, Lyras D, Levy SB, Rood JI. The Clostridium perfringens Tet P determinant comprises two overlapping genes: tetA(P), which mediates active tetracycline efflux, and tetB(P), which is related to the ribosomal protection family of tetracycline-resistance determinants. Mol Microbiol 1994; 11:403-15. [PMID: 8170402 DOI: 10.1111/j.1365-2958.1994.tb00320.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The complete nucleotide sequence and mechanism of action of the tetracycline-resistance determinant, Tet P, from Clostridium perfringens has been determined. Analysis of the 4.4 kb of sequence data revealed the presence of two open reading frames, designated as tetA(P) and tetB(P). The tetA(P) gene appears to encode a 420 amino acid protein (molecular weight 46,079) with twelve transmembrane domains. This gene was shown to be responsible for the active efflux of tetracycline from resistant cells. Although there was some amino acid sequence similarity between the putative TetA(P) protein and other tetracycline efflux proteins, analysis suggested that TetA(P) represented a different type of efflux protein. The tetB(P) gene would encode a putative 652 amino acid protein (molecular weight 72,639) with significant sequence similarity to Tet(M)-like cytoplasmic proteins that specify a ribosomal-protection tetracycline-resistance mechanism. In both C. perfringens and Escherichia coli, tetB(P) encoded low-level resistance to tetracycline and minocycline whereas tetA(P) only conferred tetracycline resistance. The tetA(P) and tetB(P) genes appeared to be linked in an operon, which represented a novel genetic arrangement for tetracycline-resistance determinants. It is proposed that tetB(P) evolved from the conjugative transfer into C. perfringens of a tet(M)-like gene from another bacterium.
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Affiliation(s)
- J Sloan
- Department of Microbiology, Monash University, Clayton, Australia
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38
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Grewal J, Manavathu EK, Taylor DE. Effect of mutational alteration of Asn-128 in the putative GTP-binding domain of tetracycline resistance determinant Tet(O) from Campylobacter jejuni. Antimicrob Agents Chemother 1993; 37:2645-9. [PMID: 8109930 PMCID: PMC192766 DOI: 10.1128/aac.37.12.2645] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The deduced amino acid sequence of Campylobacter jejuni Tet(O), cloned in Escherichia coli, has shown that it contains the five highly conserved sequences of the GTP-binding domain found in other GTPases. Asn-128 belongs to the G4 motif of such a domain and is involved in hydrogen bonding with the guanine ring of the nucleotide. Substitution of Asn-128 by 11 other amino acids resulted in a decrease in tetracycline resistance, indicating that tetracycline resistance conferred by Tet(O) is related to GTP binding. The effect of the mutations on the GTP-binding domain is discussed with the EF-Tu-GDP complex as a model.
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Affiliation(s)
- J Grewal
- Department of Medical Microbiology and Infectious Diseases, University of Alberta, Edmonton, Canada
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39
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Charpentier E, Gerbaud G, Courvalin P. Characterization of a new class of tetracycline-resistance gene tet(S) in Listeria monocytogenes BM4210. Gene 1993; 131:27-34. [PMID: 8370538 DOI: 10.1016/0378-1119(93)90665-p] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The nucleotide sequence of the tetracycline (Tc)-minocycline (Mc)-resistance determinant of plasmid pIP811 from Listeria monocytogenes BM4210 has been determined. The gene, designated tet(S), was identified by analysis of the start and stop codons as a coding sequence of 1923 bp, corresponding to a protein with a calculated M(r) of 72,912. The apparent 68-kDa size estimated by sodium dodecyl sulfate-polyacrylamide-gel electrophoresis of the protein characterized in a cell-free coupled transcription-translation system was in good agreement with the calculated value. The tet(S) gene product exhibits 79 and 72% amino acid identity with Tet(M) from Streptococcus pneumoniae and Tet(O) from Campylobacter coli, respectively. The distribution of tet(S) in strains of Gram+ and Gram- genera resistant to Tc (TcR) and Mc (McR) was studied by hybridization under high stringency using a 590-bp intragenic probe. Homology with tet(S) was detected in two clinical isolates of L. monocytogenes isolated in different geographical areas.
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Affiliation(s)
- E Charpentier
- Unité des Agents Antibactériens, Institut Pasteur, Paris, France
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40
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Lépine G, Lacroix JM, Walker CB, Progulske-Fox A. Sequencing of a tet(Q) gene isolated from Bacteroides fragilis 1126. Antimicrob Agents Chemother 1993; 37:2037-41. [PMID: 7916585 PMCID: PMC188119 DOI: 10.1128/aac.37.9.2037] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Recently, Tet Q, a tetracycline resistance determinant that confers resistance by a ribosome protection mechanism, was described and added to the two previously described classes, Tet M and Tet O. The first representative of this class, tetA(Q)1, was isolated from Bacteroides thetaiotaomicron DOT. We report the sequencing of a gene isolated from B. fragilis 1126 which also confers tetracycline resistance. Because of its high degree of identity (97%) with the tetA(Q)1 gene, we defined it as tetA(Q)2. MIC studies revealed that tetA(Q)2 provides a low level of resistance to tetracycline when cloned into Escherichia coli. The extensive homology between tetA(Q)1 and tetA(Q)2 supports the idea of a recent horizontal transfer of tet(Q) genes among Bacteroides spp.
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Affiliation(s)
- G Lépine
- Periodontal Disease Research Center, College of Dentistry, University of Florida, Gainesville 32610
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41
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Burdett V. Antibiotic Resistance. Science 1993. [DOI: 10.1126/science.259.5092.163.b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Vickers Burdett
- Department of Microbiology and Immunology, Duke University Medical Center, Durham, NC 27710
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42
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Burdett V. Antibiotic Resistance. Science 1993. [DOI: 10.1126/science.259.5092.163-b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Vickers Burdett
- Department of Microbiology and Immunology, Duke University Medical Center, Durham, NC 27710
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43
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Brighty KE, Kohlbrenner W, McGuirk PR. Chapter 15. Recent Developments in Antibacterial Resistance Mechanisms. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 1993. [DOI: 10.1016/s0065-7743(08)60885-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
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44
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Speer BS, Shoemaker NB, Salyers AA. Bacterial resistance to tetracycline: mechanisms, transfer, and clinical significance. Clin Microbiol Rev 1992; 5:387-99. [PMID: 1423217 PMCID: PMC358256 DOI: 10.1128/cmr.5.4.387] [Citation(s) in RCA: 286] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Tetracycline has been a widely used antibiotic because of its low toxicity and broad spectrum of activity. However, its clinical usefulness has been declining because of the appearance of an increasing number of tetracycline-resistant isolates of clinically important bacteria. Two types of resistance mechanisms predominate: tetracycline efflux and ribosomal protection. A third mechanism of resistance, tetracycline modification, has been identified, but its clinical relevance is still unclear. For some tetracycline resistance genes, expression is regulated. In efflux genes found in gram-negative enteric bacteria, regulation is via a repressor that interacts with tetracycline. Gram-positive efflux genes appear to be regulated by an attenuation mechanism. Recently it was reported that at least one of the ribosome protection genes is regulated by attenuation. Tetracycline resistance genes are often found on transmissible elements. Efflux resistance genes are generally found on plasmids, whereas genes involved in ribosome protection have been found on both plasmids and self-transmissible chromosomal elements (conjugative transposons). One class of conjugative transposon, originally found in streptococci, can transfer itself from streptococci to a variety of recipients, including other gram-positive bacteria, gram-negative bacteria, and mycoplasmas. Another class of conjugative transposons has been found in the Bacteroides group. An unusual feature of the Bacteroides elements is that their transfer is enhanced by preexposure to tetracycline. Thus, tetracycline has the double effect of selecting for recipients that acquire a resistance gene and stimulating transfer of the gene.
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Affiliation(s)
- B S Speer
- Keck Laboratories, California Institute of Technology, Pasadena 91125
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45
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Dittrich W, Schrempf H. The unstable tetracycline resistance gene of Streptomyces lividans 1326 encodes a putative protein with similarities to translational elongation factors and Tet(M) and Tet(O) proteins. Antimicrob Agents Chemother 1992; 36:1119-24. [PMID: 1510403 PMCID: PMC188846 DOI: 10.1128/aac.36.5.1119] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Streptomyces lividans contains a genetically unstable tetracycline resistance determinant. Nucleotide sequencing revealed an open reading frame of 1,917 nucleotides. The transcriptional start site was mapped at about 110 bp upstream of the ATG codon. The proposed promoter contains an 8-bp perfect inverted repeat between the -10 and -35 regions. The deduced amino acid sequence showed several motifs which are commonly found in many GTP-binding proteins. On the basis of its amino acid sequence, the presumptive S. lividans 1326 protein belongs to the Tet(M)-Tet(O) group of tetracycline resistance proteins and shows significant similarity to translational elongation factors of prokaryotes and eukaryotes.
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Affiliation(s)
- W Dittrich
- FB Biologie/Chemie, Universität Osnabrück, Germany
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46
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Doyle D, McDowall KJ, Butler MJ, Hunter IS. Characterization of an oxytetracycline-resistance gene, otrA, of Streptomyces rimosus. Mol Microbiol 1991; 5:2923-33. [PMID: 1809836 DOI: 10.1111/j.1365-2958.1991.tb01852.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The sequence of a 2657 bp DNA fragment containing the coding and regulatory regions of the oxytetracycline (OTC)-resistance gene, otrA, from the OTC producer Streptomyces rimosus was determined. The predicted amino acid sequence of OtrA had extensive identity with tetracycline-resistance genes from other bacteria which mediate resistance via non-covalent ribosomal modification. The N-terminal domain had extremely high identity with the GTP-binding sites of elongation factors, such as EF-G and EF-Tu, suggesting that binding and hydrolysis of GTP is important to the function of the protein. Significant identity with EF-G was present throughout the polypeptide. Transcriptional activity upstream of the otrA coding region was investigated. An Escherichia coli-type promoter, otrAp1, was identified. Transcriptional readthrough of otrA from the upstream gene (otcZ) was also detected in S. rimosus cultures. A divergent promoter activity was identified with subclones of the OtrA fragment in promoter probe vectors analysed in Streptomyces lividans. However, this activity was not identified in a subclone containing more than half of the otrA coding sequence in S. lividans or at all in S. rimosus, indicating that OtrA negatively regulates the expression of the divergent transcript. The data are consistent with regulation of antibiotic production by OtrA to prevent 'suicide'.
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Affiliation(s)
- D Doyle
- Institute of Genetics, University of Glasgow, UK
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47
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Wang Y, Taylor DE. A DNA sequence upstream of the tet(O) gene is required for full expression of tetracycline resistance. Antimicrob Agents Chemother 1991; 35:2020-5. [PMID: 1722078 PMCID: PMC245318 DOI: 10.1128/aac.35.10.2020] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The DNA sequences upstream of the tet(O) and tet(M) open reading frames (ORFs) (ca. 300 bp) were found to share a higher degree of homology than those of the tet(O) and tet(M) ORFs themselves. A transcription initiation site for tet(O) was located by primer extension analysis. Campylobacter coli was found to use a promoter sequence different from that used by Escherichia coli. The sequence upstream of tet(O) was shown to be required in cis for high-level resistance to tetracycline.
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Affiliation(s)
- Y Wang
- Department of Microbiology, University of Alberta, Edmonton, Canada
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48
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Affiliation(s)
- G A Jacoby
- Infectious Disease Unit, Massachusetts General Hospital, Boston 02114
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49
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Burdett V. Purification and characterization of Tet(M), a protein that renders ribosomes resistant to tetracycline. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)49928-0] [Citation(s) in RCA: 91] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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50
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Buck MA, Cooperman BS. Single protein omission reconstitution studies of tetracycline binding to the 30S subunit of Escherichia coli ribosomes. Biochemistry 1990; 29:5374-9. [PMID: 2200507 DOI: 10.1021/bi00474a024] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In previous work we showed that on photolysis of Escherichia coli ribosomes in the presence of [3H]tetracycline (TC) the major protein labeled is S7, and we presented strong evidence that such labeling takes place from a high-affinity site related to the inhibitory action of TC [Goldman, R. A., Hasan, T., Hall, C. C., Strycharz, W. A., & Cooperman, B. S. (1983) Biochemistry 22, 359-368]. In this work we use single protein omission reconstitution (SPORE) experiments to identify those proteins that are important for high-affinity TC binding to the 30S subunit, as measured by both cosedimentation and filter binding assays. With respect to both sedimentation coefficients and relative Phe-tRNAPhe binding, the properties of the SPORE particles we obtain parallel very closely those measured earlier [Nomura, M., Mizushima, S., Ozaki, M., Traub, P., & Lowry, C. V. (1969) Cold Spring Harbor Symp. Quant. Biol. 34, 49-61], with the exception of the SPORE particle lacking S13. A total of five proteins, S3, S7, S8, S14, and S19, are shown to be important for TC binding, with the largest effects seen on omission of proteins S7 and S14. Determination of the protein compositions of the corresponding SPORE particles demonstrates that the observed effects are, for the most part, directly attributable to the omission of the given protein rather than reflecting an indirect effect of omitting one protein on the uptake of another. A large body of evidence supports the notion that four of these proteins, S3, S7, S14, and S19, are included, along with 16S rRNA bases 920-1396, in one of the major domains of the 30S subunit.
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Affiliation(s)
- M A Buck
- Department of Chemistry, University of Pennsylvania, Philadelphia 19104
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