Plasmid pKpQIL encoding KPC-3 and TEM-1 confers carbapenem resistance in an extremely drug-resistant epidemic Klebsiella pneumoniae strain

Azita Leavitt, Inna Chmelnitsky, Itzhak Ofek, Yehuda Carmeli, Shiri Navon-Venezia

פרסום מחקרי: פרסום בכתב עתמאמרביקורת עמיתים

83 ציטוטים ‏(Scopus)

תקציר

Objectives: An extremely drug-resistant (XDR) clone of KPC-3-producing Klebsiella pneumoniae emerged in Israel in 2006, causing a nationwide outbreak. We aimed to characterize the local KPC-3-encoding plasmid carried by these isolates and study its contribution to antibiotic resistance. Methods: Mechanisms of carbapenem resistance were investigated in seven selected isolates (isolated between 2006 and 2008) belonging to the epidemic clone. Isolates underwent MIC testing, and were examined for the presence of KPC, Tn4401, class I integron elements and additional antibiotic resistance genes. Plasmids were analysed by transformation, transconjugation, restriction mapping, curing and complementation experiments. Outer membrane protein (OMP) analysis was performed. Results: OMP analysis did not reveal loss of porins. KPC-3-producing K. pneumoniae isolates possessed various plasmids but all harboured a common self-transmissible 105 kb plasmid, termed pKpQIL, encoding blaTEM-1 and blaKPC-3. Curing of pKpQIL led to a complete loss of resistance to cephalosporins and carbapenems, proving its crucial role in carbapenem resistance. Transformation of plasmid pKpQIL into the cured Klebsiella strain resulted in full reconstitution of carbapenem resistance. The presence of all Tn4401 transposon elements located upstream of the KPC-3 gene was detected by PCR and sequencing. pKpQIL lacked additional antibiotic resistance genes. Conclusions: Our findings demonstrate the presence of pKpQIL, a 105 kb KPC-3- and TEM-1-encoding plasmid, in the XDR K. pneumoniae epidemic strain in Israel. pKpQIL is unique and appears consistently in all isolates of this clone over the years. The extensive β-lactam resistance phenotype of this clone is primarily mediated by this single self-transmissible plasmid.

שפה מקוריתאנגלית
עמודים (מ-עד)243-248
מספר עמודים6
כתב עתJournal of Antimicrobial Chemotherapy
כרך65
מספר גיליון2
מזהי עצם דיגיטלי (DOIs)
סטטוס פרסוםפורסם - 24 נוב׳ 2009
פורסם באופן חיצוניכן

טביעת אצבע

להלן מוצגים תחומי המחקר של הפרסום 'Plasmid pKpQIL encoding KPC-3 and TEM-1 confers carbapenem resistance in an extremely drug-resistant epidemic Klebsiella pneumoniae strain'. יחד הם יוצרים טביעת אצבע ייחודית.

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