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From multidrug-resistant to extensively drug-resistant tuberculosis in Lisbon, Portugal: the stepwise mode of resistance acquisition

dc.contributor.authorPerdigao, João
dc.contributor.authorMacedo, Rita
dc.contributor.authorSilva, Carla
dc.contributor.authorMachado, Diana
dc.contributor.authorCouto, Isabel
dc.contributor.authorViveiros, Miguel
dc.contributor.authorJordão, Luísa
dc.contributor.authorPortugal, Isabel
dc.date.accessioned2013-02-06T16:14:47Z
dc.date.available2013-02-06T16:14:47Z
dc.date.issued2012-10
dc.description.abstractObjectives: The development and transmission of extensively drug-resistant (XDR) tuberculosis (TB) constitutes a serious threat to the effective control of TB in several countries. Here, in an attempt to further elucidate the dynamics of the acquisition of resistance to second-line drugs and investigate an eventual role for eis promoter mutations in aminoglycoside resistance, we have studied a set of multidrug-resistant (MDR)/XDR-TB isolates circulating in Lisbon, Portugal. Methods: Forty-four MDR-TB or XDR-TB isolates were genotyped and screened for mutations in genes associated with second-line drug resistance, namely tlyA, gyrA, rrs and eis. Results: The most prevalent mutations found in each gene were Ins755GT in tlyA, A1401G in rrs, G-10A in eis and S91P in gyrA. Additionally, two genetic clusters were found in this study: Lisboa3 and Q1. The characteristic mutational profile found among recent XDR-TB circulating in Lisbon was also found in MDR-TB strains isolated in the 1990s. Also investigated was the resistance level conferred by eis G-10A mutations, revealing that eis G-10A mutations may result in amikacin resistance undetectable by widely used phenotypic assays. Conclusions: The analysis of the distribution of the mutations found by genetic clustering showed that in the Q1 cluster, two mutations, gyrA D94A and rrs A1401G, were enough to ensure development of XDR-TB from an MDR strain. Moreover, in the Lisboa3 cluster it was possible to elaborate a model in which the development of low-level kanamycin resistance was at the origin of the emergence of XDR-TB strains that can be discriminated by tlyA mutations.por
dc.identifier.citationJ Antimicrob Chemother. 2013 Jan;68(1):27-33. Epub 2012 Oct 10.por
dc.identifier.issn0305-7453
dc.identifier.otherdoi: 10.1093/jac/dks371
dc.identifier.urihttp://hdl.handle.net/10400.18/1187
dc.language.isoengpor
dc.peerreviewedyespor
dc.publisherOxford University Presspor
dc.relation.publisherversionhttp://jac.oxfordjournals.org/content/68/1/27.longpor
dc.subjectLisboa Familypor
dc.subjectKanamycinpor
dc.subjectAmikacinpor
dc.subjectCross-resistancepor
dc.subjectInfecções Respiratóriaspor
dc.titleFrom multidrug-resistant to extensively drug-resistant tuberculosis in Lisbon, Portugal: the stepwise mode of resistance acquisitionpor
dc.typejournal article
dspace.entity.typePublication
oaire.citation.endPage33por
oaire.citation.startPage27por
oaire.citation.titleJournal of Antimicrobial Chemotherapypor
oaire.citation.volume68(1)por
rcaap.rightsrestrictedAccesspor
rcaap.typearticlepor

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