First Report of Ceftazidime-Avibactam Resistance in a KPC-3-Expressing Klebsiella pneumoniae Isolate

ABSTRACTCeftazidime-avibactam is the first antimicrobial approved by the U.S. FDA for the treatment of carbapenem-resistantEnterobacteriaceae. Avibactam, a non-β-lactam β-lactamase inhibitor, inactivates class A serine carbapenemases, includingKlebsiella pneumoniaecarbapenemase (KPC). We report a KPC-producingK. pneumoniaeisolate resistant to ceftazidime-avibactam (MIC, 32/4 μg/ml) from a patient with no prior treatment with ceftazidime-avibactam.

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In Vivo Activity of QPX7728, an Ultrabroad-Spectrum Beta-Lactamase Inhibitor, in Combination with Beta-Lactams against Carbapenem-Resistant Klebsiella pneumoniae

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01267-20 ◽

2020 ◽

Vol 64 (11) ◽

Cited By ~ 1

Author(s):

Mojgan Sabet ◽

Ziad Tarazi ◽

David C. Griffith

Keyword(s):

Klebsiella Pneumoniae ◽

Beta Lactamase ◽

Beta Lactam ◽

Beta Lactams ◽

Bacterial Killing ◽

Clinical Issue ◽

Content Type ◽

Beta Lactam Antibiotics ◽

Carbapenem Resistant ◽

Lactamase Inhibitor

ABSTRACT Resistance to beta-lactams has created a major clinical issue. QPX7728 is a novel ultrabroad-spectrum cyclic boronic acid beta-lactamase inhibitor with activity against both serine and metallo-beta-lactamases developed to address this resistance for use in combination with beta-lactam antibiotics. The objective of these studies was to evaluate the activity of QPX7728 in combination with multiple beta-lactams against carbapenem-resistant Klebsiella pneumoniae isolates in a neutropenic mouse thigh infection model. Neutropenic mice were infected with strains with potentiated beta-lactam MICs of ≤2 mg/liter in the presence of 8 mg/liter QPX7728. Two strains of carbapenem-resistant K. pneumoniae were tested with aztreonam, biapenem, cefepime, ceftazidime, ceftolozane, and meropenem alone or in combination with 12.5, 25, or 50 mg/kg of body weight of QPX7728 every 2 hours for 24 hours. Treatment with all beta-lactams alone either was bacteriostatic or allowed for bacterial growth. The combination of QPX7728 plus each of these beta-lactams produced bacterial killing at all QPX7728 doses tested. Overall, these data suggest that QPX7728 administered in combination with different partner beta-lactam antibiotics may have utility in the treatment of bacterial infections due to carbapenem-resistant K. pneumoniae.

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Nacubactam Enhances Meropenem Activity against Carbapenem-Resistant Klebsiella pneumoniae Producing KPC

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00432-19 ◽

2019 ◽

Vol 63 (8) ◽

Cited By ~ 7

Author(s):

Melissa D. Barnes ◽

Magdalena A. Taracila ◽

Caryn E. Good ◽

Saralee Bajaksouzian ◽

Laura J. Rojas ◽

...

Keyword(s):

Molecular Modeling ◽

Klebsiella Pneumoniae ◽

The United States ◽

Alternative Mechanism ◽

Enhancer Activity ◽

Content Type ◽

Class A ◽

Carbapenem Resistant ◽

Biochemical Analyses ◽

Molecular Modeling And Docking

ABSTRACT Carbapenem-resistant Enterobacteriaceae (CRE) are resistant to most antibiotics, making CRE infections extremely difficult to treat with available agents. Klebsiella pneumoniae carbapenemases (KPC-2 and KPC-3) are predominant carbapenemases in CRE in the United States. Nacubactam is a bridged diazabicyclooctane (DBO) β-lactamase inhibitor that inactivates class A and C β-lactamases and exhibits intrinsic antibiotic and β-lactam “enhancer” activity against Enterobacteriaceae. In this study, we examined a collection of meropenem-resistant K. pneumoniae isolates carrying blaKPC-2 or blaKPC-3; meropenem-nacubactam restored susceptibility. Upon testing isogenic Escherichia coli strains producing KPC-2 variants with single-residue substitutions at important Ambler class A positions (K73, S130, R164, E166, N170, D179, K234, E276, etc.), the K234R variant increased the meropenem-nacubactam MIC compared to that for the strain producing KPC-2, without increasing the meropenem MIC. Correspondingly, nacubactam inhibited KPC-2 (apparent Ki [Ki app] = 31 ± 3 μM) more efficiently than the K234R variant (Ki app = 270 ± 27 μM) and displayed a faster acylation rate (k2/K), which was 5,815 ± 582 M−1 s−1 for KPC-2 versus 247 ± 25 M−1 s−1 for the K234R variant. Unlike avibactam, timed mass spectrometry revealed an intact sulfate on nacubactam and a novel peak (+337 Da) with the K234R variant. Molecular modeling of the K234R variant showed significant catalytic residue (i.e., S70, K73, and S130) rearrangements that likely interfere with nacubactam binding and acylation. Nacubactam’s aminoethoxy tail formed unproductive interactions with the K234R variant’s active site. Molecular modeling and docking observations were consistent with the results of biochemical analyses. Overall, the meropenem-nacubactam combination is effective against carbapenem-resistant K. pneumoniae. Moreover, our data suggest that β-lactamase inhibition by nacubactam proceeds through an alternative mechanism compared to that for avibactam.

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MCR-1 and OXA-48 In Vivo Acquisition in KPC-Producing Escherichia coli after Colistin Treatment

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02540-16 ◽

2017 ◽

Vol 61 (8) ◽

Cited By ~ 32

Author(s):

Racha Beyrouthy ◽

Frederic Robin ◽

Aude Lessene ◽

Igor Lacombat ◽

Laurent Dortet ◽

...

Keyword(s):

Escherichia Coli ◽

Klebsiella Pneumoniae ◽

Whole Genome Sequencing ◽

Genome Sequencing ◽

Whole Genome ◽

Content Type ◽

First Report ◽

E Coli ◽

Carbapenem Resistant

ABSTRACT The spread of mcr-1-encoding plasmids into carbapenem-resistant Enterobacteriaceae raises concerns about the emergence of untreatable bacteria. We report the acquisition of mcr-1 in a carbapenem-resistant Escherichia coli strain after a 3-week course of colistin in a patient repatriated to France from Portugal. Whole-genome sequencing revealed that the Klebsiella pneumoniae carbapenemase-producing E. coli strain acquired two plasmids, an IncL OXA-48-encoding plasmid and an IncX4 mcr-1-encoding plasmid. This is the first report of mcr-1 in carbapenemase-encoding bacteria in France.

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Activity of NXL104 in Combination with β-Lactams against Genetically Characterized Escherichia coli and Klebsiella pneumoniae Isolates Producing Class A Extended-Spectrum β-Lactamases and Class C β-Lactamases

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01722-10 ◽

2011 ◽

Vol 55 (5) ◽

pp. 2434-2437 ◽

Cited By ~ 65

Author(s):

P. R. S. Lagacé-Wiens ◽

F. Tailor ◽

P. Simner ◽

M. DeCorby ◽

J. A. Karlowsky ◽

...

Keyword(s):

Escherichia Coli ◽

Klebsiella Pneumoniae ◽

The Novel ◽

Content Type ◽

E Coli ◽

Class A ◽

Extended Spectrum ◽

Class C ◽

Lactamase Inhibitor

ABSTRACTThe novel non-β-lactam β-lactamase inhibitor NXL104, in combination with cefepime, ceftazidime, ceftriaxone, amdinocillin, and meropenem, was tested against 190 extended-spectrum β-lactamase (ESBL)-producingEscherichia coliandKlebsiella pneumoniaeisolates, 94 AmpC-hyperproducingE. coliisolates, and 8 AmpC/ESBL-coexpressingE. coliisolates. NXL104 restored 100% susceptibility to the partner cephalosporins for all isolates tested. Amdinocillin and meropenem MICs were modestly improved (2 to 32 times lower) by NXL104. These results suggest that NXL104 may be useful in combination with β-lactams for the treatment of infections caused by ESBL- and AmpC-producingEnterobacteriaceae.

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First Report ofblaIMP-8in Raoultella planticola

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00231-13 ◽

2013 ◽

Vol 58 (1) ◽

pp. 593-595 ◽

Cited By ~ 28

Author(s):

Sung-Pin Tseng ◽

Jann-Tay Wang ◽

Chih-Yuan Liang ◽

Pei-Shan Lee ◽

Yee-Chun Chen ◽

...

Keyword(s):

Klebsiella Pneumoniae ◽

Gel Electrophoresis ◽

Pulsed Field Gel Electrophoresis ◽

Protein Loss ◽

Class 1 Integron ◽

Raoultella Planticola ◽

Content Type ◽

First Report ◽

Carbapenem Resistant ◽

Class 1

ABSTRACTTwo carbapenem-resistantRaoultella planticolaclinical isolates were isolated from patients with pneumonia and Port-A catheter-related bacteremia, respectively, in Taiwan. These isolates remained susceptible to fluoroquinolone, aminoglycoside, and colistin. Though the two isolates had the same antibiogram, plasmidic carbapenemaseblaIMP-8, class 1 integron cassette (dfrA12-orfF-aadA2), andqnrB2, they had different pulsed-field gel electrophoresis patterns, plasmid sizes, and outer membrane protein loss profiles. To our knowledge, this is the first report ofblaIMP-8found inR. planticola. Interestingly,blaIMP-8is the most common carbapenemase found inKlebsiella pneumoniaein Taiwan. In the literature, carbapenemase genes inR. planticolain each country were also found in carbapenem-resistantEnterobacteriaceaein the same country.

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Changes in the Frequencies of β-Lactamase Genes among Enterobacteriaceae Isolates in U.S. Hospitals, 2012 to 2014: Activity of Ceftazidime-Avibactam Tested against β-Lactamase-Producing Isolates

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00540-16 ◽

2016 ◽

Vol 60 (8) ◽

pp. 4770-4777 ◽

Cited By ~ 38

Author(s):

Mariana Castanheira ◽

Rodrigo E. Mendes ◽

Ronald N. Jones ◽

Helio S. Sader

Keyword(s):

Escherichia Coli ◽

Klebsiella Pneumoniae ◽

South Atlantic ◽

Content Type ◽

E Coli ◽

Carbapenem Resistant ◽

Inhibitor Combination ◽

Lactamase Inhibitor ◽

M 14 ◽

Over Time

ABSTRACTAmong 15,588Enterobacteriaceaeisolates collected in 63 U.S. hospitals from 2012 to 2014, 2,129 (13.7%) displayed an extended-spectrum β-lactamase (ESBL) phenotype. These rates were similar over time (13.2 to 13.9%); however, differences amongEscherichia coli(12.7 and 15.1% in 2012 and 2014;P= 0.007) andKlebsiella pneumoniae(18.9 and 15.5% in 2012 and 2014;P= 0.006) were noted when comparing 2014 and 2012. Carbapenem-resistantEnterobacteriaceae(CRE) (2.3 and 1.8%) and carbapenem-resistantK. pneumoniae(6.8 and 5.1%;P= 0.003) rates were lower in 2014 than in 2012. Isolates carryingblaCTX-M-15-like genes were stable (42.1 to 42.4%), but a decrease amongE. coliisolates (59.1 and 49.7%;P= 0.008) and an increase amongK. pneumoniaeisolates (32.7 and 41.2%;P= 0.022) in 2014 were observed. Isolates carryingblaKPC(304) decreased over the years (16.5 and 10.9%;P= 0.008), mainly due to the decrease inK. pneumoniaeisolates harboringblaKPC(n= 285; 35.6 and 28.4%;P= 0.041) in hospitals in the Mid-Atlantic and South Atlantic regions, where these isolates were highly prevalent during 2012 and 2013. Isolates carryingblaCMY-2-like andblaCTX-M-14-like genes increased (8.2 and 11.9% and 9.1 and 12.9%, respectively;P= 0.04 for both), and those producingblaSHVESBL decreased (24.9 and 12.7%;P< 0.001) over the studied years, due to a decreased occurrence of the enzymes amongK. pneumoniaeisolates. Other enzymes were detected in smaller numbers of isolates, including fourK. pneumoniaeisolates carryingblaNDM-1metallo-β-lactamase (two in 2012 and two in 2014). Ceftazidime-avibactam, a recently approved β-lactamase inhibitor combination, was very active against the ESBL phenotype isolates (MIC50/90, 0.12 and 1 μg/ml; 99.7% susceptible) and CRE strains (MIC50/90, 0.5 and 2 μg/ml; 98.5% susceptible) that displayed elevated MIC values for many comparator agents. In conclusion, significant changes were noted in the frequencies of isolates harboring various β-lactamases among U.S. hospitals between 2012 and 2014 that will require continued monitoring.

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Colistin Resistance in Carbapenem-Resistant Klebsiella pneumoniae Mediated by Chromosomal Integration of Plasmid DNA

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00404-17 ◽

2017 ◽

Vol 61 (8) ◽

Cited By ~ 2

Author(s):

Astrid V. Cienfuegos-Gallet ◽

Liang Chen ◽

Barry N. Kreiswirth ◽

J. Natalia Jiménez

Keyword(s):

Klebsiella Pneumoniae ◽

Plasmid Dna ◽

Clonal Expansion ◽

Genetic Alterations ◽

Sequence Type ◽

Chromosomal Integration ◽

Colistin Resistance ◽

Content Type ◽

Carbapenem Resistant ◽

Single Locus Variant

ABSTRACT Here we describe the spread of colistin resistance in clinical isolates of carbapenem-resistant Klebsiella pneumoniae in Medellín, Colombia. Among 32 isolates collected between 2012 and 2014, 24 showed genetic alterations in mgrB. Nineteen isolates belonged to sequence type 512 (ST512) (or its single locus variant [SLV]) and harbored an 8.1-kb hsdMSR insertion corresponding to ISKpn25, indicating a clonal expansion of the resistant strain. The insertion region showed 100% identity to several plasmids, suggesting that the colistin resistance is mediated by chromosomal integration of plasmid DNA.

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Colistin Heteroresistance Is Largely Undetected among Carbapenem-Resistant Enterobacterales in the United States

mBio ◽

10.1128/mbio.02881-20 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Victor I. Band ◽

Sarah W. Satola ◽

Richard D. Smith ◽

David A. Hufnagel ◽

Chris Bower ◽

...

Keyword(s):

United States ◽

Klebsiella Pneumoniae ◽

Diagnostic Testing ◽

Cladistic Analysis ◽

The United States ◽

Clinical Diagnostics ◽

Infection Model ◽

Content Type ◽

Carbapenem Resistant ◽

Clinical Diagnostic

ABSTRACT Heteroresistance is a form of antibiotic resistance where a bacterial strain is comprised of a minor resistant subpopulation and a majority susceptible subpopulation. We showed previously that colistin heteroresistance can mediate the failure of colistin therapy in an in vivo infection model, even for isolates designated susceptible by clinical diagnostics. We sought to characterize the extent of colistin heteroresistance among the highly drug-resistant carbapenem-resistant Enterobacterales (CRE). We screened 408 isolates for colistin heteroresistance. These isolates were collected between 2012 and 2015 in eight U.S. states as part of active surveillance for CRE. Colistin heteroresistance was detected in 10.1% (41/408) of isolates, and it was more common than conventional homogenous resistance (7.1%, 29/408). Most (93.2%, 38/41) of these heteroresistant isolates were classified as colistin susceptible by standard clinical diagnostic testing. The frequency of colistin heteroresistance was greatest in 2015, the last year of the study. This was especially true among Enterobacter isolates, of which specific species had the highest rates of heteroresistance. Among Klebsiella pneumoniae isolates, which were the majority of isolates tested, there was a closely related cluster of colistin-heteroresistant ST-258 isolates found mostly in Georgia. However, cladistic analysis revealed that, overall, there was significant diversity in the genetic backgrounds of heteroresistant K. pneumoniae isolates. These findings suggest that due to being largely undetected in the clinic, colistin heteroresistance among CRE is underappreciated in the United States. IMPORTANCE Heteroresistance is an underappreciated phenomenon that may be the cause of some unexplained antibiotic treatment failures. Misclassification of heteroresistant isolates as susceptible may lead to inappropriate therapy. Heteroresistance to colistin was more common than conventional resistance and was overwhelmingly misclassified as susceptibility by clinical diagnostic testing. Higher proportions of colistin heteroresistance observed in certain Enterobacter species and clustering among heteroresistant Klebsiella pneumoniae strains may inform colistin treatment recommendations. Overall, the rate of colistin nonsusceptibility was more than double the level detected by clinical diagnostics, suggesting that the prevalence of colistin nonsusceptibility among CRE may be higher than currently appreciated in the United States.

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Epigenomics, genomics, resistome, mobilome, virulome and evolutionary phylogenomics of carbapenem-resistant Klebsiella pneumoniae clinical strains

Microbial Genomics ◽

10.1099/mgen.0.000474 ◽

2020 ◽

Vol 6 (12) ◽

Author(s):

Katlego Kopotsa ◽

Nontombi M. Mbelle ◽

John Osei Sekyere

Keyword(s):

Klebsiella Pneumoniae ◽

Multidrug Resistant ◽

Type I ◽

Bacteriophage Therapy ◽

Content Type ◽

Carbapenem Resistant ◽

Plasmid Replicon ◽

Size Number ◽

Plasmid Size ◽

Epidemiological Trends

Carbapenem-resistant Klebsiella pneumoniae (CRKP) remains a major clinical pathogen and public health threat with few therapeutic options. The mobilome, resistome, methylome, virulome and phylogeography of CRKP in South Africa and globally were characterized. CRKP collected in 2018 were subjected to antimicrobial susceptibility testing, screening by multiplex PCR, genotyping by repetitive element palindromic (REP)-PCR, plasmid size, number, incompatibility and mobility analyses, and PacBio’s SMRT sequencing (n=6). There were 56 multidrug-resistant CRKP, having bla OXA-48-like and bla NDM-1/7 carbapenemases on self-transmissible IncF, A/C, IncL/M and IncX3 plasmids endowed with prophages, traT, resistance islands, and type I and II restriction modification systems (RMS). Plasmids and clades detected in this study were respectively related to globally established/disseminated plasmids clades/clones, evincing transboundary horizontal and vertical dissemination. Reduced susceptibility to colistin occurred in 23 strains. Common clones included ST307, ST607, ST17, ST39 and ST3559. IncFIIk virulent plasmid replicon was present in 56 strains. Whole-genome sequencing of six strains revealed least 41 virulence genes, extensive ompK36 mutations, and four different K- and O-loci types: KL2, KL25, KL27, KL102, O1, O2, O4 and O5. Types I, II and III RMS, conferring m6A (G A TC, G A TGNNNNNNTTG, CA A NNNNNNCATC motifs) and m4C (C C WGG) modifications on chromosomes and plasmids, were found. The nature of plasmid-mediated, clonal and multi-clonal dissemination of blaOXA-48-like and blaNDM-1 mirrors epidemiological trends observed for closely related plasmids and sequence types internationally. Worryingly, the presence of both bla OXA-48 and bla NDM-1 in the same isolates was observed. Plasmid-mediated transmission of RMS, virulome and prophages influence bacterial evolution, epidemiology, pathogenicity and resistance, threatening infection treatment. The influence of RMS on antimicrobial and bacteriophage therapy needs urgent investigation.

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Sequence Type 273 Carbapenem-Resistant Klebsiella pneumoniae Carrying bla NDM-1 and bla IMP-4

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00160-18 ◽

2018 ◽

Vol 62 (6) ◽

Cited By ~ 4

Author(s):

Lu Liu ◽

Yu Feng ◽

Haiyan Long ◽

Alan McNally ◽

Zhiyong Zong

Keyword(s):

Klebsiella Pneumoniae ◽

Southeast Asia ◽

Human Blood ◽

Sequence Type ◽

Whole Genome Sequence ◽

Whole Genome ◽

Content Type ◽

Carbapenem Resistant ◽

Transmissible Plasmid ◽

Long Read

ABSTRACT A carbapenem-resistant Klebsiella pneumoniae isolate was recovered from human blood. Its whole-genome sequence was obtained using Illumina and long-read MinION sequencing. The strain belongs to sequence type 273 (ST273), which was found recently and caused an outbreak in Southeast Asia. It has two carbapenemase genes, bla NDM-1 (carried by an ST7 IncN self-transmissible plasmid) and bla IMP-4 (located on a self-transmissible IncHI5 plasmid). Non-KPC-producing ST237 may represent a lineage of carbapenem-resistant K. pneumoniae , which warrants further monitoring.

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