Research in the Kreiswirth Lab

A major concentration of the laboratories’ current research focuses on unraveling the molecular epidemiology of carbapenem resistant Enterobacteriaceae. The sentinel study, published in PNAS in 2014 (Figure), dissected the genomic characteristics of the most prevalent Klebsiella pneumoniae Carbapenemase (KPC) ST258 clone and the resistance plasmids it harbors. The sequence analysis revealed that ST258 is not a single clone, but two genetically conserved clades that differ in a highly recombinagenic region that switches the capsular and lipopolysaccharide gene clusters. Dr. Kreiswirth’s group also showed that ST258 is a recent clone that evolved as a result of a gross recombination between ST11 and ST442. Sequencing of blaKPC plasmids identified more than 10 different incompatibility types and they identified 3 major conjugative plasmids that are successfully spreading with K. pneumoniae and among other species in Enterobacteriaceae.

The lab has also been involved in the genetic characterization of the emerging Enterobacteriaceae strains from China harboring the plasmid mediated mcr-1 gene which encodes for colistin resistance. They also identified the first US patient in 2015 harboring a multidrug resistant mcr-1 resistant E. coli strain.

As a result of being able to switch its capsule type by chromosomal exchange, the bacteria is able to change its antigenicity and divert the host response. In collaboration with researchers at NIH, Dr. Kreiswirth’s lab demonstrated that the cell wall capsule prevents neutrophil binding, but antibodies directed against the capsule restores binding and neutrophil killing. Developing capsular antibodies as a therapeutic approach to treat multidrug resistant K. pneumoniae infections among immunosuppressed populations provides a novel yet classic approach that can work in combination with antibiotics.

A second major research effort is focused on understanding the genomic structure of Mycobacterium abscessus complex strains in high risk cancer, transplant and CF patients and the repurposing of dual β-lactam compounds. The important initial observation was that certain dual β-lactams are synergistic against highly resistant clinical isolates of M. abscessus. The unexpected result was observed with ceftazidime, a third generation cephalosporin that has poor activity against M. abscessus clinical isolates, but highly synergistic in combination with either imipenem or ceftaroline. Dr. Kreiswirth’s group also showed that the dual β-lactams were active against intracellular M. abscessus in a THP-1 infection assay and in kill curve experiments. Conditional mutants that turn off the expression of the remodeling enzymes showed a direct effect on cell permeability and the redundancy of function among the cell wall enzymes. The β-lactam testing against clinical isolates of M. abscessus recovered from CF patients will extend the group’s initial findings and identify additional combinations that have synergistic activity.

Related Publications

Molecular Epidemiology of Enterobacteriaceae Studies

Deleo FR, Chen L, Porcella SF, Martens CA, Kobayashi SD, Porter AR, Chavda
KD, Jacobs MR, Mathema B, Olsen RJ, Bonomo RA, Musser JM, Kreiswirth BN.
Molecular dissection of the evolution of carbapenem-resistant multilocus sequence
type 258 Klebsiella pneumoniae. Proc Natl Acad Sci U S A. 2014 Apr
1;111(13):4988-93. doi: 10.1073/pnas.1321364111. Epub 2014 Mar 17. PubMed PMID:
24639510; PubMed Central PMCID: PMC3977278.

Chen L, Mathema B, Chavda KD, DeLeo FR, Bonomo RA, Kreiswirth BN.
Carbapenemase-producing Klebsiella pneumoniae: molecular and genetic decoding.
Trends Microbiol. 2014 Dec;22(12):686-96. doi: 10.1016/j.tim.2014.09.003. Epub
2014 Oct 7. Review. PubMed PMID: 25304194; PubMed Central PMCID: PMC4365952.

Chen L, Mathema B, Pitout JD, DeLeo FR, Kreiswirth BN. Epidemic Klebsiella
pneumoniae ST258 is a hybrid strain. MBio. 2014 Jun 24;5(3):e01355-14. doi:
10.1128/mBio.01355-14. PubMed PMID: 24961694; PubMed Central PMCID: PMC4073492

Satlin MJ, Chen L, Patel G, Gomez-Simmonds A, Weston G, Kim AC, Seo SK,
Rosenthal ME, Sperber SJ, Jenkins SG, Hamula CL, Uhlemann AC, Levi MH, Fries BC,
Tang YW, Juretschko S, Rojtman AD, Hong T, Mathema B, Jacobs MR, Walsh TJ, Bonomo RA, Kreiswirth BN. Multicenter Clinical and Molecular Epidemiological Analysis of Bacteremia Due to Carbapenem-Resistant Enterobacteriaceae (CRE) in the CRE
Epicenter of the United States. Antimicrob Agents Chemother. 2017 Mar 24;61(4).
pii: e02349-16. doi: 10.1128/AAC.02349-16. Print 2017 Apr. PubMed PMID: 28167547;
PubMed Central PMCID: PMC5365653.

Matsumura Y, Peirano G, Devinney R, Bradford PA, Motyl MR, Adams MD, Chen L,
Kreiswirth B, Pitout JDD. Genomic epidemiology of global VIM-producing
Enterobacteriaceae. J Antimicrob Chemother. 2017 Aug 1;72(8):2249-2258. doi:
10.1093/jac/dkx148. PubMed PMID: 28520983; PubMed Central PMCID: PMC5890710.

Peirano G, Matsumura Y, Adams MD, Bradford P, Motyl M, Chen L, Kreiswirth BN,
Pitout JDD. Genomic Epidemiology of Global Carbapenemase-Producing Enterobacter
spp., 2008-2014. Emerg Infect Dis. 2018 Jun;24(6):1010-1019. doi:
10.3201/eid2406.171648. PubMed PMID: 29774858; PubMed Central PMCID: PMC6004858.

Plasmid studies

Chen L, Chavda KD, Melano RG, Jacobs MR, Koll B, Hong T, Rojtman AD, Levi MH, Bonomo RA, Kreiswirth BN. Comparative genomic analysis of KPC-encoding
pKpQIL-like plasmids and their distribution in New Jersey and New York Hospitals.
Antimicrob Agents Chemother. 2014 May;58(5):2871-7. doi: 10.1128/AAC.00120-14.
Epub 2014 Mar 10. PubMed PMID: 24614371; PubMed Central PMCID: PMC3993205.

Peirano G, Bradford PA, Kazmierczak KM, Chen L, Kreiswirth BN, Pitout JD.
Importance of Clonal Complex 258 and IncF(K2-like) Plasmids among a Global
Collection of Klebsiella pneumoniae with bla(KPC). Antimicrob Agents Chemother.
2017 Mar 24;61(4). pii: e02610-16. doi: 10.1128/AAC.02610-16. Print 2017 Apr.
PubMed PMID: 28167556; PubMed Central PMCID: PMC5365689.

Plasmid mcr-1 Studies

Mediavilla JR, Patrawalla A, Chen L, Chavda KD, Mathema B, Vinnard C, Dever
LL, Kreiswirth BN. Colistin- and Carbapenem-Resistant Escherichia coli Harboring
mcr-1 and blaNDM-5, Causing a Complicated Urinary Tract Infection in a Patient
from the United States. MBio. 2016 Aug 30;7(4). pii: e01191-16. doi:
10.1128/mBio.01191-16. PubMed PMID: 27578755; PubMed Central PMCID: PMC4999550.

Yu H, Qu F, Shan B, Huang B, Jia W, Chen C, Li A, Miao M, Zhang X, Bao C, Xu
Y, Chavda KD, Tang YW, Kreiswirth BN, Du H, Chen L. Detection of the mcr-1
Colistin Resistance Gene in Carbapenem-Resistant Enterobacteriaceae from
Different Hospitals in China. Antimicrob Agents Chemother. 2016 Jul
22;60(8):5033-5. doi: 10.1128/AAC.00440-16. Print 2016 Aug. PubMed PMID:
27216058; PubMed Central PMCID: PMC4958199.

Li A, Yang Y, Miao M, Chavda KD, Mediavilla JR, Xie X, Feng P, Tang YW,
Kreiswirth BN, Chen L, Du H. Complete Sequences of mcr-1-Harboring Plasmids from
Extended-Spectrum-β-Lactamase- and Carbapenemase-Producing Enterobacteriaceae.
Antimicrob Agents Chemother. 2016 Jun 20;60(7):4351-4. doi: 10.1128/AAC.00550-16.
Print 2016 Jul. PubMed PMID: 27090180; PubMed Central PMCID: PMC4914624.

Du H, Chen L, Tang YW, Kreiswirth BN. Emergence of the mcr-1 colistin
resistance gene in carbapenem-resistant Enterobacteriaceae. Lancet Infect Dis.
2016 Mar;16(3):287-8. doi: 10.1016/S1473-3099(16)00056-6. Epub 2016 Feb 1. PubMed PMID: 26842776.

Zhang H, Miao M, Yan J, Wang M, Tang YW, Kreiswirth BN, Zhang X, Chen L, Du H.
Expression characteristics of the plasmid-borne mcr-1 colistin resistance gene.
Oncotarget. 2017 Nov 20;8(64):107596-107602. doi: 10.18632/oncotarget.22538.
eCollection 2017 Dec 8. PubMed PMID: 29296190; PubMed Central PMCID: PMC5746092.

Chavda B, Lv J, Hou M, Chavda KD, Kreiswirth BN, Feng Y, Chen L, Yu F.
Coidentification of mcr-4.3 and bla(NDM-1) in a Clinical Enterobacter cloacae
Isolate from China. Antimicrob Agents Chemother. 2018 Sep 24;62(10). pii:
e00649-18. doi: 10.1128/AAC.00649-18. Print 2018 Oct. PubMed PMID: 30038043;
PubMed Central PMCID: PMC6153785.

Huang B, He Y, Ma X, Cai R, Zeng J, Lu Y, Zhang W, Lan K, E S, Tang YW,
Kreiswirth BN, Chen C, Chen L. Promoter Variation and Gene Expression of
mcr-1-Harboring Plasmids in Clinical Isolates of Escherichia coli and Klebsiella
pneumoniae from a Chinese Hospital. Antimicrob Agents Chemother. 2018 Apr
26;62(5). pii: e00018-18. doi: 10.1128/AAC.00018-18. Print 2018 May. PubMed PMID:
29463536; PubMed Central PMCID: PMC5923141.

Capsule Studies

Chen L, Chavda KD, Findlay J, Peirano G, Hopkins K, Pitout JD, Bonomo RA,
Woodford N, DeLeo FR, Kreiswirth BN. Multiplex PCR for identification of two
capsular types in epidemic KPC-producing Klebsiella pneumoniae sequence type 258
strains. Antimicrob Agents Chemother. 2014 Jul;58(7):4196-9. doi:10.1128/AAC.02673-14. Epub 2014 Apr 14. PubMed PMID: 24733470; PubMed Central PMCID: PMC4068549.

Kobayashi SD, Porter AR, Dorward DW, Brinkworth AJ, Chen L, Kreiswirth BN,
DeLeo FR. Phagocytosis and Killing of Carbapenem-Resistant ST258 Klebsiella
pneumoniae by Human Neutrophils. J Infect Dis. 2016 May 15;213(10):1615-22. doi:
10.1093/infdis/jiw001. Epub 2016 Jan 14. PubMed PMID: 26768252; PubMed Central
PMCID: PMC4837910.

DeLeo FR, Kobayashi SD, Porter AR, Freedman B, Dorward DW, Chen L, Kreiswirth BN. Survival of Carbapenem-Resistant Klebsiella pneumoniae Sequence Type 258 in Human Blood. Antimicrob Agents Chemother. 2017 Mar 24;61(4). pii: e02533-16. doi:10.1128/AAC.02533-16. Print 2017 Apr. PubMed PMID: 28115349; PubMed Central PMCID: PMC5365663.

Kobayashi SD, Porter AR, Freedman B, Pandey R, Chen L, Kreiswirth BN, DeLeo
FR. Antibody-Mediated Killing of Carbapenem-Resistant ST258 Klebsiella pneumoniae
by Human Neutrophils. MBio. 2018 Mar 13;9(2). pii: e00297-18. doi:
10.1128/mBio.00297-18. PubMed PMID: 29535199; PubMed Central PMCID: PMC5850326.

M. abscessus Studies

Pandey R, Chen L, Manca C, Jenkins S, Glaser L, Vinnard C, Stone G, Lee J,
Mathema B, Nuermberger EL, Bonomo RA, Kreiswirth BN. Dual β-Lactam Combinations Highly Active against Mycobacterium abscessus Complex In Vitro. MBio. 2019 Feb 12;10(1). pii: e02895-18. doi: 10.1128/mBio.02895-18. PubMed PMID: 30755518; PubMed Central PMCID: PMC6372805.