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ry ib ra ES C M ID O n © lin by e L au ec th tu or re L Genetic Elements that spread multi-drug resistance determinants in Gram-negative bacteria: how complex is the problem? Timothy R. Walsh ry ib ra n © lin by e L au ec th tu or re L Remit of Talk • Will not detail integrons and movement of integrons ES C M ID O • Will choose few and only key examples of 1. plasmids 2. transposons 3. ISCR elements...... to illustrate clinically import examples – and choose key resistant genes ry ib ra Channel Four Study ES C M ID O n © lin by e L au ec th tu or re L 171 swabs -156 grew meropenem resistant Gram-negatives) - 51/171 (29.8%) were positive for NDM-1 50 water samples - 14 grew meropenem resistant Gram-negatives) - 2 out of 50 (4%) were positive for NDM-1 Environmental positive samples C M ID O Escherichia coli Suttonella indologenes Shigella boydii Stenotrophomonas maltophilia Aeromonas caviae Citrobacter freundii Pseudomonas oryzihabitans Pseudomonas pseudoalcaligenes Pseudomonas putida Vibrio cholera ES ry ib ra 116 97 n © lin by e L au ec th tu or re L 3 ry ib ra n © lin by e L au ec th tu or re L O ID M C ES Walsh et al., Lancet Infectious Diseases, April 2011 ry ib ra n © lin by e L au ec th tu or re L O ID M C ES Walsh et al., Lancet Infectious Diseases, April 2011 ry ES C M ID O n © lin by e L au ec th tu or re L ib ra blaNDM-1 genes are carried on AC plasmids Some isolates have two copies of blaNDM-1 P T P T P T P O n © lin by e L au ec th tu or re L ID M C ES T T M P T P T P T P ib ra ry –IR9 IR9 IR19 IR22 –180kb –P T P T P T P T O –160kb –150kb –IR3 IR9 IR19 IR22 n © lin by e L au ec th tu or re L –P T P T P T P T ib ra ry –Changes to NDM‐1 A/C plasmids during conjuga;on ES C M ID –90kb –F –A/C ry n © lin by e L au ec th tu or re L ib ra What are Transposons? Transposons, also called "hopping genes" are segments of DNA that are able to move around in the genome ID O They were originally suggested by Barbara McClintock based on research she did the 1930's and 1940's ES C M The simplest kind code only for the enzymes that cut them out of their current DNA molecule and insert them into another one ry n © lin by e L au ec th tu or re L ib ra What are IS Elements ES C M ID O • Small and simple.....generally encode no funcCons other than those involved in their mobility • Required in cis, in par,cular recombina,onally ac,ve • DNA sequences which define the ends of the element, together with an enzyme, the transposase which recognizes and processes these ends • The transposase is generally encoded by one or perhaps two open reading frames and consumes nearly the enCre length of the element ry n © lin by e L au ec th tu or re L ib ra Mechanism of transposition ID O • The simplest sequence of events: • The transposase recognizes and binds to the transposable element • It then acts as a site-specific endonuclease, cleaving the DNA to expose the element's 3'-OH ends • A duplex target DNA then binds to the complex • Direct attack of the 3'-OH ends on phosphates of the duplex cleaving it and joining it to the transposon • Since the phosphates attacked are staggered, short single strand gaps remain, which are filled in by the regular repair mechanisms ES C M • Mode of binding is the same as the mode of binding of transcription factors to DNA: a helix in the major groove. • Some Type 1 transposases cleave the 5' ends of the transposon as well. ry n © lin by e L au ec th tu or re L ib ra ES C M ID O Tn5 Bound to Ends of Transposon DNA Binding Domain of Tn3 Transposase Bound to the Transposon ry n © lin by e L au ec th tu or re L ib ra Nomenclature of Transposons ES C M ID O Revised nomenclature for transposable gene,c elements Chandler et al., 2008. Plasmid, 60; 167-173 ry INT aacA7 blaVIM‐2 blaVIM‐2 aacA4 ES C M ID O INT n © lin by e L au ec th tu or re L ib ra GeneCc Elements changing and moving resistance genes around Europe aacC1 aacA4 qacEÄ1/sul French VIM-2 qacEÄ1/sul Poland VIM-2 ES C M ID O n © lin by e L au ec th tu or re L ib ra ry Schematic representation of the blaIMP-13 and blaVIM-2 genetic loci, and comparison with the 5′ end of the composite mercury resistance transposon Tn21, which includes the transposition (tnp) and integron In2 region (GenBank accession no. Toleman M A et al. J. Antimicrob. Chemother. 2003;52:583-590 ry ib ra n © lin by e L au ec th tu or re L Tn5090/Tn402‐like IRi aadA2 aadB IRt qacEΔ1/sul Δtnib tniA ES C M ID O TGTCGTTTTCAGAAGACGGCTGCAC-------AGGGGTAGTGAATCCGCCAGATTGACTTGCGCTGCCCTACCTCTCACTAGTGAGGGG TGTCGTTTTCAGAAGACGGCTGCAC-------AGGGGTAGTGAATCCGCCAGATTGACTTGCGCTGCCCTACCTCTCACTAGTGAGGGG TGTCGTTTTCAGAAGACGGCTGCAC-------AGGGGTAGTGAATCCGCCAGATTGACTTGCGCTGCCCTACCTCTCACTAGTGAGGGG TGTCGTTTTCAGAAGACGGCTGCAC-------AGGGGTAGTGAATCCGCCAGATTGACTTGCGCTGCCCTACCTCTCACTAGTGAGGGG TGTCGTTTTCAGAAGACGGCTGCAC-------AGGGGTAGTGAATCCGCCAGATTGACTTGCGCTGCCCTACCTCTCACTAGTGAGGGG TGTCGTTTTCAGAAGACGGCTGCAC-------AGGGGTAGTGAATCCGCCAGATTGACTTGCGCTGCCCTACCTCTCACTAGTGAGGGG TGTCGTTTTCAGAAGACGGCTGCAC-------AGGGGTAGTGAATCCGCCAGATTGACTTGCGCTGCCCTACCTCTCACTAGTGAGGGG TGTCGTTTTCAGAAGACGGCTGCAC-------AGGGGTAGTGAATCCGCCAGATTGACTTGCGCTGCCCTACCTCTCACTAGTGAGGGG TGTCGTTTTCAGAAGACGGCTGCAC-------AGGGGTAGTGAATCCGCCAGATTGACTTGCGCTGCCCTACCTCTCACTAGTGAGGGG TGTCGTTTTCAGAAGACGGCTGCAC-------AGGGGTAGTGAATCCGCCAGATTGACTTGCGCTGCCCTACCTCTCACTAGTGAGGGG TGTCGTTTTCAGAAGACGGCTGCAC-------AGGGGTAGTGAATCCGCCAGATTGACTTGCGCTGCCCTACCTCTCACTAGTGAGGGG TGTCGTTTTCAGAAGACGGCTGCAC-------AGGGGTAGTGAATCCGCCAGATTGACTTGCGCTGCCCTACCTCTCACTAGTGAGGGG IRi * integrase ry ib ra ES C M ID O n © lin by e L au ec th tu or re L Evolution of Tn5090/Tn402-like elements Toleman et al., 2007. Antimicrob Agents Chemother. 51 2636-8. ry -3 and the PCR scheme used to amplify it. C M ID O n © lin by e L au ec th tu or re L ib ra Representation of Tn4401a harbouring blaKPC ES Curiao T et al. J. Antimicrob. Chemother. 2010;65:1608 -1614 © TheAuthor 2010. Publishedby OxfordUniversity Press on behalf of theBritishSociety for Antimicrobial Chemotherapy. All rights reserved. For Permissions, pleasee -mail: [email protected] ry ib ra n © lin by e L au ec th tu or re L O ID M C ES Tato et al., 2010. ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, 54; 320–327 ry ib ra n © lin by e L au ec th tu or re L O ID M C ES Tato et al., 2010. ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, 54; 320–327 ry ib ra n © lin by e L au ec th tu or re L O ID M C ES Lar,gue et al., 2004. FEMS. 234: 201‐207 ES C M ID O n © lin by e L au ec th tu or re L ib ra ry ISEcp1B mediated transposiCon Poirel et al., 2005. AAC. 49:447-550 ry n © lin by e L au ec th tu or re L ib ra What are ISCR Elements? ES C M ID O • One ended transposiCon elements • Only recently been associated with anCbioCc resistance • Replicate via rolling circle transposiCon • Capable of carry large segments of DNA to their leX hand side including many anCbioCc resistance genes ry ib ra n © lin by e L au ec th tu or re L Common Regions - 1993 catA2 qac/sul orf5/orf6 aadA2 qac/sul aadB qac/sul AJ517791 ID O dfrA10 qac/sul orf5 Common Region ES C M L06822 (In6) Stokes HW, Tomaras C, Parsons Y, Hall RM. Plasmid. 1993, 30:39-50 L06418 (In7) blaOXA-45 terIS eltA/B terIS ES C M ID O co‐transposed genes n © lin by e L au ec th tu or re L ry ib ra Direc&on of rolling circle replica&on ISCR5 oriIS IS91 oriIS ry ib ra FormaCon of Complex Class 1 integrons aadA2 qacEΔ1/sul orf5/orf6 ISCR1 Deletion event removing terIS and fusing the ISCR1 element to the 3’ conserved sequence of the class 1 integron C aadA2 ES intI1 oriIS M ID O intI1 qacEΔ1/sul oriIS n © lin by e L au ec th tu or re L terIS ISCR1 ry ib ra n © lin by e L au ec th tu or re L O ID M C ES Coque and Canton. Current Opinion in Microbiology. 2006. oriIS intI1 aadA2 qacEΔ1/sul1 ry ISCR1 (ii) (iii) (iv) dfrA10 qacEΔ1/sul1 (ii) ISCR1 (iii) dfrA10 intI1 aadA2 qacEΔ1/sul1 ISCR1 ISCR1 (v) dfrA10 aadA2 qacEΔ1/sul1 (vi) dfrA10 intI1 aadA2 qacEΔ1/sul1 ISCR1 ISCR1 ISCR1 A aadB dfrA10 aadA2 qacEΔ1/sul1 n © lin by e L au ec th tu or re L (i) dfrA10 qacEΔ1/sul1 ib ra (i) C B aadB orf5/orf6 qacEΔ1/sul1 orf5/orf6 aadB aadB ID A O qacEΔ1/sul1 aadB dfrA10 ISCR1 qacEΔ1/sul1 ISCR1 orf5/orf6 aadA2 dfrA10 orf5/orf6 ES C M B ISCR1 orf5/orf6 Toleman et al., JAC. 2006 C aadB ISCR1 aadA2 dfrA10 orf5/orf6 ISCR1 ry ib ra n © lin by e L au ec th tu or re L O ID M C ES Toleman et al. 2007. Emerging Infec,ous Diseases. 13; 559‐565 qac/sul floR qac ISCR3 tetG qac/sul orf5 intI1/groEL ib ra aadA2 ry Importance of ISCR3 elements (55%ID ISCR1) blaPSE‐1 aadA2 qac/sul floR tetG qac/sul intI1/groEL qac dfrA10 qac/sul orf5 aadA2 n © lin by e L au ec th tu or re L blaPSE‐1 aadA2 qac/sul qac/sul orf5/6 qac/sul floR dfrA1 orfC qac/sul intI1/groEL qac tetG blaPSE‐1 floR tetG qac IS6100 intI1/groEL SGI1‐D floR SGI1‐E qac/sul blaPSE‐1 SGI1‐F hhp://www.cardiff.ac.uk/medic/aboutus/departments/medical floR tetG qac intI1/groEL orfC qac/sul orf5/6 SGI1‐I microbiology/geneCcs/iscrelements.html dfrA1 qac/sul dfrA1 orfC SGI1‐A dfrA10 qac/sul orf5 IS6100 aadA2 SGI1 floR qac/sul tetG qac O yieF/yieG ES Scale =1kb SGI1‐J AY434092 AY434093 yieE/yieF/orfX C M ID yieE intI1/groEL qac/sul blaTEM‐1 rmtB AY434091 erm A15097 intI1/groEL tnpR Toleman et al. 2006. Microbiology and Molecular Biology Reviews. 70: 296‐316. AB103506 ib ra ry Integrating conjugative elements (ICEs) n © lin by e L au ec th tu or re L •A class of bacterial mobile genetic elements that disseminate via conjugation and then integrate into the host cell genome. •The SXT/R391 family of ICEs consists of more than 30 different elements that all share the same integration site in the host chromosome but often encode distinct properties. •Comparative analyses of the genomes of several SXT/R391 ICEs, found that the genomes have been shaped by inter–ICE recombination. M ID O •Conjugation facilitates the segregation of hybrids and could provide a means to select for functional recombinant ICEs containing novel combinations of genes conferring resistance to antibiotics. ES C •ICEs promote their own diversity and can yield novel mobile elements capable of disseminating new combinations of antibiotic resistance genes. Genevie`ve et al., 2009. PlosGen 5; 1‐11 O n © lin by e L au ec th tu or re L ID M C ES ib ra How complex? ry ry ib ra n © lin by e L au ec th tu or re L O ID M C ES Fournier et al. 2006. Compara,ve genomics of mul,‐drug resistance in Acinetobacter baumannii. Gene,cs. 2: 62‐72 ES C M ID O n © lin by e L au ec th tu or re L ib ra ry AnCbioCc genes belonging to MDR A. baumannii strain AYE Fournier et al. 2006. Compara,ve genomics of mul,‐drug resistance in Acinetobacter baumannii. Gene,cs. 2: 62‐72 blaNDM-1 ΔIS26 ry ΔblaDHA-1 ΔPAI ΔTn3 ib ra Δldh n © lin by e L au ec th tu or re L efflux pump (4-6kb) Int1 arr-2 ereC aadA1 cmlA7 qacEΔ1 ES C M ID O (1-4kb) Yong et al., 2009. Antimicrobial Agents and Chemotherapy. 53; 5046-54 Poirel et al. 2010. Antimicrobial Agents and Chemotherapy. 54; 4914-4916 ISCR1 ib ra Acinetobacter spp. AbaI1 25 NDM-1 Enterobacteriaceae Gene X ∆AbaI1 25 .................................................................. ID NDM-1 ISCR groEL groES ES C M ISCR NDM-1 Curr Opin Microbiol. 2010 Dec;13(6):781‐5. Toxin‐an,toxin systems: why so many, what for? Van Melderen L. O Enterobacteriaceae .................................................................. n © lin by e L au ec th tu or re L Gene X ry The perfect weapon? DHA-1, CMY-6, aar-2, ereC, aadA1, aacA4, cmlA7, armA, rmtC, rmtD, sul1, dhfr, sul2, toxin-anti-toxin system - MqsA ry ID O n © lin by e L au ec th tu or re L ib ra Chronology of movement of AbxR genes Event 3 Event 4 C ES Event 2 M Event 1 ry ES C M ID O n © lin by e L au ec th tu or re L ib ra Major structural features of pKOX105, encoding VIM -1, QnrS1 and SHV -12, in comparison with IncN plasmids p9 and p12 carrying KPC -2 and KPC -3, respectively, and the IncN reference plasmid R46. Carattoli A et al. J. Antimicrob. Chemother. 2010;jac.dkq269 © TheAuthor 2010. Publishedby OxfordUniversity Press on behalf of theBritishSociety for Antimicrobial Chemotherapy. All rights reserved. For Permissions, pleasee -mail: [email protected] ry n © lin by e L au ec th tu or re L ib ra How complex is the problem? ES C M ID O • Although known for a long, transposons have only recently been associated with MDR and PDR Gram‐ negaCve bacteria • Safe haven for inserCon but can also be destrucCve • This associaCon may or may not be associated with drug consumpCon but anCbioCcs such as fluoroquinolones have secondary effects promoCng gene mobility • The complexity (and associated plasCcity and fluidity) will become greater over Cme • A warning to genome sequencers O n © lin by e L au ec th tu or re L ID M C ES ib ra ry • Jan Bell C M ID O Mark Toleman Dongeun Yong Sonia Ferreira Allaaeddin El Salabi Sahim Agouri Jonathan Tynddell Janis Weeks Mandy Wootton Robin Howe Vicky Davies ES • • • • • • • • • • n © lin by e L au ec th tu or re L ry ib ra Acknowledgements • David Paterson • Hanna Sdajbat • Laurent Poirel • Patrice Nordmann