CG258 #Klebsiella pneumoniae isolates without β-lactam #resistance at the onset of the #carbapenem-resistant #Enterobacteriaceae #epidemic in #NYC (J Antimicrob Chemother., abstract)

[Source: Journal of Antimicrobial Chemotherapy, full page: (LINK). Abstract, edited.]

CG258 Klebsiella pneumoniae isolates without β-lactam resistance at the onset of the carbapenem-resistant Enterobacteriaceae epidemic in New York City

Brandon Eilertson, Liang Chen, Audrey Li, Kalyan D Chavda, Bhakti Chavda, Barry N Kreiswirth

Journal of Antimicrobial Chemotherapy, dky394,

Published: 01 October 2018




To examine the epidemiology of β-lactam resistance in ‘clonal group 258’ (CG258), a successful KPC clonal group, over 14 years.


Isolates were collected from 1999 to 2013 for a study of antibiotic resistance in Enterobacteriaceae in New York City; 515 bloodstream isolates had antibiotic susceptibility data available and 436 were available for a CG258 PCR assay. The 56 resulting CG258 isolates were characterized by MLST, capsular type and ESBL and KPC carriage. KPC-positive isolates were assessed for common KPC plasmid types, KPC subtype and Tn4401 isoform.


RT–PCR revealed 56 isolates were CG258. Seventeen of the 56 CG258 isolates were phenotypically susceptible to all carbapenems (all KPC negative). Five out of 17 susceptible isolates were of the cps-2 (wzi154) capsule type; none was cps-1 (wzi29). Nineteen out of 28 KPC-2 isolates were cps-1 (wzi29) and 8/10 KPC-3 isolates carried cps-2 (wzi154); however, cps-2 (wzi154) predominated among KPC-2-positive isolates in 2003 and 2004. KPC-2 was first detected in 2003 and KPC-3 was first detected in 2006. KPC-harbouring plasmids pKpQIL (all Tn4401a) and pBK30683 (all Tn4401d) were detected in 16/38 and 6/38 carbapenem-resistant isolates, respectively.


CG258-lineage Klebsiella pneumoniae isolates were completely absent in 1999, but common in 2003. Twenty-one percent of CG258 isolates were susceptible to carbapenems in addition to lacking both common ESBL and blaKPC-mediated resistance. The cps-2 (wzi154) capsule type was common in both these susceptible isolates and in early KPC-2-harbouring isolates, suggesting it was the initial capsule type in CG258. Carbapenem-resistant isolates carried common KPC-harbouring plasmids with the same KPC and Tn4401 isoforms, suggesting frequent clonal spread.

Topic: polymerase chain reaction – plasmids – antibiotic resistance, bacterial – carbapenem – epidemiology – disease transmission – enterobacteriaceae – klebsiella pneumoniae – lactams – new york city – protein isoforms – reverse transcriptase  polymerase chain reaction – epidemics – antimicrobial susceptibility – multi-antibiotic resistance – extended-spectrum beta lactamases – bacterial carbapenemase resistance blakpc gene – carbapenem resistance – carbapenem-resistant enterobacteriaceae


© The Author(s) 2018. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For permissions, please email:

This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (

Keywords: Antibiotics; Drugs Resistance; Carbapenem; Beta-lactams; Enterobacteriaceae; NYC; USA; Klebsiella pneumoniae.



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I am an Italian blogger, active since 2005 with main focus on emerging infectious diseases such as avian influenza, SARS, antibiotics resistance, and many other global Health issues. Other fields of interest are: climate change, global warming, geological and biological sciences. My activity consists mainly in collection and analysis of news, public services updates, confronting sources and making decision about what are the 'signals' of an impending crisis (an outbreak, for example). When a signal is detected, I follow traces during the entire course of an event. I started in 2005 my blog ''A TIME'S MEMORY'', now with more than 40,000 posts and 3 millions of web interactions. Subsequently I added an Italian Language blog, then discontinued because of very low traffic and interest. I contributed for seven years to a public forum ( in the midst of the Ebola epidemic in West Africa in 2014, I left the site to continue alone my data tracking job.

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