scholarly journals KPC-53, a KPC-3 Variant of Clinical Origin Associated with Reduced Susceptibility to Ceftazidime-Avibactam

2020 ◽  
Vol 65 (1) ◽  
pp. e01429-20
Author(s):  
Vincenzo Di Pilato ◽  
Noemi Aiezza ◽  
Valentina Viaggi ◽  
Alberto Antonelli ◽  
Luigi Principe ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Whole Genome Sequencing ◽  
Clinical Isolate ◽  
Genome Sequencing ◽  
Whole Genome ◽  
Mechanisms Of Resistance ◽  
Content Type ◽  
High Level ◽  
Level Resistance

ABSTRACTThis study reports on the characterization of a Klebsiella pneumoniae clinical isolate showing high-level resistance to ceftazidime-avibactam associated with the production of KPC-53, a KPC-3 variant exhibiting a Leu167Glu168 duplication in the Ω-loop and a loss of carbapenemase activity. Whole-genome sequencing (WGS) revealed the presence of two copies of blaKPC-53, located on a pKpQIL-like plasmid and on a plasmid prophage of the Siphoviridae family, respectively. The present findings provide new insights into the mechanisms of resistance to ceftazidime-avibactam.

scholarly journals Whole-Genome Sequencing of Mycobacterium tilburgii Strain MEPHI

2019 ◽  
Vol 8 (40) ◽  
Author(s):  
Jamal Saad ◽  
Michel Drancourt ◽  
Margaret M. Hannan ◽  
Patrick J. Stapleton ◽  
Simon Grandjean Lapierre
Keyword(s):  
Whole Genome Sequencing ◽  
Clinical Isolate ◽  
Genome Sequencing ◽  
Gc Content ◽  
Whole Genome ◽  
Content Type ◽  
Phylogenetic Placement ◽  
Mycobacterium Simiae

Mycobacterium tilburgii is a fastidious mycobacterium which has previously been reported to cause severe disseminated infections. Genome sequencing of the M. tilburgii MEPHI clinical isolate yielded 3.14 Mb, with 66.3% GC content, and confirmed phylogenetic placement within the Mycobacterium simiae complex.

scholarly journals High-Level Antibiotic Tolerance of a Clinically Isolated Enterococcus faecalis Strain

2020 ◽  
Vol 87 (1) ◽  
Author(s):  
Huan Gu ◽  
Sweta Roy ◽  
Xiaohui Zheng ◽  
Tian Gao ◽  
Huilin Ma ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Whole Genome Sequencing ◽  
Cystic Fibrosis Patient ◽  
Enterococcus Faecalis ◽  
Antibiotic Treatment ◽  
Genome Sequencing ◽  
Efflux Pump ◽  
Whole Genome ◽  
Content Type ◽  
High Level

ABSTRACT Bacteria can survive antibiotic treatment both by acquiring antibiotic resistance genes and through mechanisms of tolerance that are based on phenotypic changes and the formation of metabolically inactive cells. Here, we report an Enterococcus faecalis strain (E. faecalis UM001B) that was isolated from a cystic fibrosis patient and had no increase in resistance but extremely high-level tolerance to ampicillin, vancomycin, and tetracycline. Specifically, the percentages of cells that survived 3.5-h antibiotic treatment (at 100 μg · ml−1) were 25.4% ± 4.3% and 51.9% ± 4.0% for ampicillin and tetracycline, respectively; vancomycin did not exhibit any significant killing. Consistent with the changes in antibiotic susceptibility, UM001B was found to have reduced penetration of ampicillin and vancomycin and accumulation of tetracycline compared to the reference strain ATCC 29212. Based on whole-genome sequencing, four amino acid substitutions were identified in one of the tetracycline efflux pump repressors (TetRs), compared to ATCC 29212. Results of molecular simulations and experimental assays revealed that these mutations could lead to higher levels of tetracycline efflux activity. Consistently, replicating these mutations in Escherichia coli MG1655 increased its tolerance to tetracycline. Overall, these findings provide new insights into the development of multidrug tolerance in E. faecalis, which can facilitate future studies to better control enterococcal infections. IMPORTANCE Enterococcus faecalis represents a major group of pathogens causing nosocomial infections that are resistant to multiple classes of antibiotics. An important challenge associated with E. faecalis infection is the emergence of multidrug-tolerant strains, which have normal MICs but do not respond to antibiotic treatment. Here, we report a strain of E. faecalis that was isolated from a cystic fibrosis patient and demonstrated high-level tolerance to ampicillin, vancomycin, and tetracycline. Whole-genome sequencing revealed critical substitutions in one of the tetracycline efflux pump repressors that are consistent with the increased tolerance of E. faecalis UM001B to tetracycline. These findings provide new information about bacterial antibiotic tolerance and may help develop more effective therapeutics.

scholarly journals Characterization of SXT/R391 Integrative and Conjugative Elements in Proteus mirabilis Isolates from Food-Producing Animals in China

2016 ◽  
Vol 60 (3) ◽  
pp. 1935-1938 ◽  
Author(s):  
Chang-Wei Lei ◽  
An-Yun Zhang ◽  
Hong-Ning Wang ◽  
Bi-Hui Liu ◽  
Li-Qin Yang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Resistance Genes ◽  
Proteus Mirabilis ◽  
Whole Genome ◽  
Content Type ◽  
Integrative And Conjugative Elements ◽  
Animal Farms

SXT/R391 integrative and conjugative elements (ICEs) were detected in 8 out of 125Proteus mirabilisisolates from food-producing animals in China. Whole-genome sequencing revealed that seven ICEs were identical to ICEPmiJpn1, carrying the cephalosporinase geneblaCMY-2. Another one, designated ICEPmiChn1, carried five resistance genes. All eight ICEs could be transferred toEscherichia colivia conjugation. The results highlight the idea that animal farms are important reservoir of the SXT/R391 ICE-containingP. mirabilis.

scholarly journals Whole-Genome Sequencing of Human ClinicalKlebsiella pneumoniaeIsolates Reveals Misidentification and Misunderstandings ofKlebsiella pneumoniae,Klebsiella variicola, andKlebsiella quasipneumoniae

mSphere ◽  
2017 ◽  
Vol 2 (4) ◽  
Author(s):  
S. Wesley Long ◽  
Sarah E. Linson ◽  
Matthew Ojeda Saavedra ◽  
Concepcion Cantu ◽  
James J. Davis ◽  
...  
Keyword(s):  
Homologous Recombination ◽  
Klebsiella Pneumoniae ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Clinical Microbiology ◽  
Whole Genome ◽  
Beta Lactamase ◽  
Opportunistic Pathogens ◽  
Content Type ◽  
Strain Collection

ABSTRACTKlebsiella pneumoniaeis a major threat to public health, causing significant morbidity and mortality worldwide. The emergence of highly drug-resistant strains is particularly concerning. There has been a recognition and division ofKlebsiella pneumoniaeinto three distinct phylogenetic groups:Klebsiella pneumoniae,Klebsiella variicola, andKlebsiella quasipneumoniae.K. variicolaandK. quasipneumoniaehave often been described as opportunistic pathogens that have less virulence in humans thanK. pneumoniaedoes. We recently sequenced the genomes of 1,777 extended-spectrum-beta-lactamase (ESBL)-producingK. pneumoniaeisolates recovered from human infections and discovered that 28 strains were phylogenetically related toK.variicolaandK. quasipneumoniae. Whole-genome sequencing of 95 additional non-ESBL-producingK. pneumoniaeisolates recovered from patients found 12K. quasipneumoniaestrains. Matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) analysis initially identified all patient isolates asK. pneumoniae, suggesting a potential pitfall in conventional clinical microbiology laboratory identification methods. Whole-genome sequence analysis revealed extensive sharing of core gene content and plasmid replicons among theKlebsiellaspecies. For the first time, strains of bothK. variicolaandK. quasipneumoniaewere found to carry theKlebsiella pneumoniaecarbapenemase (KPC) gene, while anotherK. variicolastrain was found to carry the New Delhi metallo-beta-lactamase 1 (NDM-1) gene.K. variicolaandK. quasipneumoniaeinfections were not less virulent thanK. pneumoniaeinfections, as assessed by in-hospital mortality and infection type. We also discovered evidence of homologous recombination in oneK. variicolastrain, as well as one strain from a novelKlebsiellaspecies, which challenge the current understanding of interrelationships between clades ofKlebsiella.IMPORTANCEKlebsiella pneumoniaeis a serious human pathogen associated with resistance to multiple antibiotics and high mortality.K. variicolaandK. quasipneumoniaeare closely related organisms that are generally considered to be less-virulent opportunistic pathogens. We used a large, comprehensive, population-based strain collection and whole-genome sequencing to investigate infections caused by these organisms in our hospital system. We discovered thatK. variicolaandK. quasipneumoniaeisolates are often misidentified asK. pneumoniaeby routine clinical microbiology diagnostics and frequently cause severe life-threatening infections similar toK. pneumoniae. The presence of KPC inK. variicolaandK. quasipneumoniaestrains as well as NDM-1 metallo-beta-lactamase in oneK. variicolastrain is particularly concerning because these genes confer resistance to many different beta-lactam antibiotics. The sharing of plasmids, as well as evidence of homologous recombination, between these three species ofKlebsiellais cause for additional concern.

scholarly journals Characterization of an Enterococcus gallinarum Isolate Carrying a DualvanAandvanBCassette

2015 ◽  
Vol 53 (7) ◽  
pp. 2225-2229 ◽  
Author(s):  
Alireza Eshaghi ◽  
Dea Shahinas ◽  
Aimin Li ◽  
Ruwandi Kariyawasam ◽  
Philip Banh ◽  
...  
Keyword(s):  
Clinical Isolate ◽  
Resistance Mechanism ◽  
Vancomycin Resistance ◽  
Content Type ◽  
Enterococcal Species ◽  
Enterococcus Gallinarum ◽  
High Level ◽  
Identification And Characterization ◽  
Level Resistance

The ability of vancomycin resistance determinants to be horizontally transferred within enterococci species is a concern. Identification and characterization of vancomycin-resistant enterococci (VRE) in a clinical isolate have a significant impact on infection control practices. In this study, we describe a clinical isolate ofEnterococcus gallinarumexhibiting high-level resistance to vancomycin and teicoplanin. The genetic characterization of this isolate showed the presence ofvanAandvanBgenes in addition to the naturally carriedvanCgene.vanAwas identified on pA6981, a 35,608-bp circular plasmid with significant homology to plasmid pS177. ThevanBoperon was integrated into the bacterial chromosome and showed a high level of homology to previously reported Tn1549and Tn5382. To the best of our knowledge, this is the first report ofE. gallinarumcarrying bothvanAandvanBoperons, indicating the importance of identifying the vancomycin resistance mechanism in non-E. faeciumand non-E. faecalisenterococcal species.

scholarly journals Genomic Analysis of a Pan-Resistant Isolate ofKlebsiella pneumoniae, United States 2016

mBio ◽  
2018 ◽  
Vol 9 (2) ◽  
Author(s):  
Tom J. B. de Man ◽  
Joseph D. Lutgring ◽  
David R. Lonsway ◽  
Karen F. Anderson ◽  
Julia A. Kiehlbauch ◽  
...  
Keyword(s):  
Public Health ◽  
United States ◽  
Antimicrobial Resistance ◽  
Klebsiella Pneumoniae ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
The United States ◽  
Whole Genome ◽  
Beta Lactams ◽  
Content Type

ABSTRACTAntimicrobial resistance is a threat to public health globally and leads to an estimated 23,000 deaths annually in the United States alone. Here, we report the genomic characterization of an unusualKlebsiella pneumoniae, nonsusceptible to all 26 antibiotics tested, that was isolated from a U.S. patient. The isolate harbored four known beta-lactamase genes, including plasmid-mediatedblaNDM-1andblaCMY-6, as well as chromosomalblaCTX-M-15andblaSHV-28, which accounted for resistance to all beta-lactams tested. In addition, sequence analysis identified mechanisms that could explain all other reported nonsusceptibility results, including nonsusceptibility to colistin, tigecycline, and chloramphenicol. Two plasmids, IncA/C2 and IncFIB, were closely related to mobile elements described previously and isolated from Gram-negative bacteria from China, Nepal, India, the United States, and Kenya, suggesting possible origins of the isolate and plasmids. This is one of the firstK. pneumoniaeisolates in the United States to have been reported to the Centers for Disease Control and Prevention (CDC) as nonsusceptible to all drugs tested, including all beta-lactams, colistin, and tigecycline.IMPORTANCEAntimicrobial resistance is a major public health threat worldwide. Bacteria that are nonsusceptible or resistant to all antimicrobials available are of major concern to patients and the public because of lack of treatment options and potential for spread. AKlebsiella pneumoniaestrain that was nonsusceptible to all tested antibiotics was isolated from a U.S. patient. Mechanisms that could explain all observed phenotypic antimicrobial resistance phenotypes, including resistance to colistin and beta-lactams, were identified through whole-genome sequencing. The large variety of resistance determinants identified demonstrates the usefulness of whole-genome sequencing for detecting these genes in an outbreak response. Sequencing of isolates with rare and unusual phenotypes can provide information on how these extremely resistant isolates develop, including whether resistance is acquired on mobile elements or accumulated through chromosomal mutations. Moreover, this provides further insight into not only detecting these highly resistant organisms but also preventing their spread.

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

2017 ◽  
Vol 61 (8) ◽  
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.

scholarly journals Whole-Genome Sequencing for Characterization of Capsule Locus and Prediction of Serogroup of Invasive Meningococcal Isolates

2018 ◽  
Vol 57 (3) ◽  
Author(s):  
Henju Marjuki ◽  
Nadav Topaz ◽  
Lorraine D. Rodriguez-Rivera ◽  
Edward Ramos ◽  
Caelin C. Potts ◽  
...  
Keyword(s):  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Whole Genome ◽  
Phase Variable ◽  
Rt Pcr ◽  
Content Type ◽  
Strain Collection ◽  
Capsule Locus ◽  
Outbreak Investigations

ABSTRACTInvasive meningococcal disease is mainly caused byNeisseria meningitidisserogroups A, B, C, X, W, and Y. The serogroup is typically determined by slide agglutination serogrouping (SASG) and real-time PCR (RT-PCR). We describe a whole-genome sequencing (WGS)-based method to characterize the capsule polysaccharide synthesis (cps) locus, classifyN. meningitidisserogroups, and identify mechanisms for nongroupability using 453 isolates from a global strain collection. We identified novel genomic organizations within functionalcpsloci, consisting of insertion sequence (IS) elements in unique positions that did not disrupt the coding sequence. Genetic mutations (partial gene deletion, missing genes, IS insertion, internal stop, and phase-variable off) that led to nongroupability were identified. The results of WGS and SASG were in 91% to 100% agreement for all serogroups, while the results of WGS and RT-PCR showed 99% to 100% agreement. Among isolates determined to be nongroupable by WGS (31 of 453), the results of all three methods agreed 100% for those without a capsule polymerase gene. However, 61% (WGS versus SASG) and 36% (WGS versus RT-PCR) agreements were observed for the isolates, particularly those with phase variations or internal stops incpsloci, which warrant further characterization by additional tests. Our WGS-based serogrouping method provides comprehensive characterization of theN. meningitidiscapsule, which is critical for meningococcal surveillance and outbreak investigations.

scholarly journals Characterization of an Enterobacter cloacae Strain Producing both KPC and NDM Carbapenemases by Whole-Genome Sequencing

2015 ◽  
Vol 59 (10) ◽  
pp. 6625-6628 ◽  
Author(s):  
Wenjing Wu ◽  
Yu Feng ◽  
Alessandra Carattoli ◽  
Zhiyong Zong
Keyword(s):  
Whole Genome Sequencing ◽  
Bloodstream Infection ◽  
Genome Sequencing ◽  
Carbapenem Resistance ◽  
Enterobacter Cloacae ◽  
Whole Genome ◽  
Content Type ◽  
Carbapenem Resistant

ABSTRACTA carbapenem-resistantEnterobacter cloacaestrain, WCHECl-14653, causing a fatal bloodstream infection, was characterized by genome sequencing and conjugation experiments. The strain carried two carbapenemase genes,blaNDM-1andblaKPC-2, on separate IncF plasmids. The coexistence ofblaNDM-1andblaKPC-2conferred slightly higher-level carbapenem resistance compared with that ofblaNDM-1orblaKPC-2alone, and the coexistence of two IncF plasmids may generate new platforms for spreading carbapenemase genes.

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