scholarly journals Klebsiella pneumoniae Carbapenemase (KPC)-Producing K. pneumoniae at a Single Institution: Insights into Endemicity from Whole-Genome Sequencing

2015 ◽  
Vol 59 (3) ◽  
pp. 1656-1663 ◽  
Author(s):  
Amy J. Mathers ◽  
Nicole Stoesser ◽  
Anna E. Sheppard ◽  
Louise Pankhurst ◽  
Adam Giess ◽  
...  

ABSTRACTThe global emergence ofKlebsiella pneumoniaecarbapenemase-producingK. pneumoniae(KPC-Kp) multilocus sequence type ST258 is widely recognized. Less is known about the molecular and epidemiological details of non-ST258K. pneumoniaein the setting of an outbreak mediated by an endemic plasmid. We describe the interplay ofblaKPCplasmids andK. pneumoniaestrains and their relationship to the location of acquisition in a U.S. health care institution. Whole-genome sequencing (WGS) analysis was applied to KPC-Kpclinical isolates collected from a single institution over 5 years following the introduction ofblaKPCin August 2007, as well as two plasmid transformants. KPC-Kpfrom 37 patients yielded 16 distinct sequence types (STs). Two novel conjugativeblaKPCplasmids (pKPC_UVA01 and pKPC_UVA02), carried by the hospital index case, accounted for the presence ofblaKPCin 21/37 (57%) subsequent cases. Thirteen (35%) isolates represented an emergent lineage, ST941, which contained pKPC_UVA01 in 5/13 (38%) and pKPC_UVA02 in 6/13 (46%) cases. Seven (19%) isolates were the epidemic KPC-Kpstrain, ST258, mostly imported from elsewhere and not carrying pKPC_UVA01 or pKPC_UVA02. Using WGS-based analysis of clinical isolates and plasmid transformants, we demonstrate the unexpected dispersal ofblaKPCto many non-ST258 lineages in a hospital through spread of at least two novelblaKPCplasmids. In contrast, ST258 KPC-Kpwas imported into the institution on numerous occasions, with otherblaKPCplasmid vectors and without sustained transmission. Instead, a newly recognized KPC-Kpstrain, ST941, became associated with both novelblaKPCplasmids and spread locally, making it a future candidate for clinical persistence and dissemination.

2015 ◽  
Vol 53 (4) ◽  
pp. 1144-1148 ◽  
Author(s):  
Evan McRobb ◽  
Derek S. Sarovich ◽  
Erin P. Price ◽  
Mirjam Kaestli ◽  
Mark Mayo ◽  
...  

Melioidosis, a disease of public health importance in Southeast Asia and northern Australia, is caused by the Gram-negative soil bacillusBurkholderia pseudomallei. Melioidosis is typically acquired through environmental exposure, and case clusters are rare, even in regions where the disease is endemic.B. pseudomalleiis classed as a tier 1 select agent by the Centers for Disease Control and Prevention; from a biodefense perspective, source attribution is vital in an outbreak scenario to rule out a deliberate release. Two cases of melioidosis within a 3-month period at a residence in rural northern Australia prompted an investigation to determine the source of exposure.B. pseudomalleiisolates from the property's groundwater supply matched the multilocus sequence type of the clinical isolates. Whole-genome sequencing confirmed the water supply as the probable source of infection in both cases, with the clinical isolates differing from the likely infecting environmental strain by just one single nucleotide polymorphism (SNP) each. For the first time, we report a phylogenetic analysis of genomewide insertion/deletion (indel) data, an approach conventionally viewed as problematic due to high mutation rates and homoplasy. Our whole-genome indel analysis was concordant with the SNP phylogeny, and these two combined data sets provided greater resolution and a better fit with our epidemiological chronology of events. Collectively, this investigation represents a highly accurate account of source attribution in a melioidosis outbreak and gives further insight into a frequently overlooked reservoir ofB. pseudomallei. Our methods and findings have important implications for outbreak source tracing of this bacterium and other highly recombinogenic pathogens.


2014 ◽  
Vol 53 (1) ◽  
pp. 323-326 ◽  
Author(s):  
Birgit De Smet ◽  
Derek S. Sarovich ◽  
Erin P. Price ◽  
Mark Mayo ◽  
Vanessa Theobald ◽  
...  

Burkholderia pseudomalleiisolates with shared multilocus sequence types (STs) have not been isolated from different continents. We identified two STs shared between Australia and Cambodia. Whole-genome analysis revealed substantial diversity within STs, correctly identified the Asian or Australian origin, and confirmed that these shared STs were due to homoplasy.


mSystems ◽  
2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Yuan Wu ◽  
Chen Liu ◽  
Wen-Ge Li ◽  
Jun-Li Xu ◽  
Wen-Zhu Zhang ◽  
...  

ABSTRACTHorizontal gene transfer of mobile genetic elements (MGEs) accounts for the mosaic genome ofClostridium difficile, leading to acquisition of new phenotypes, including drug resistance and reconstruction of the genomes. MGEs were analyzed according to the whole-genome sequences of 37C. difficileisolates with a variety of sequence types (STs) within clade 4 from China. Great diversity was found in each transposon even within isolates with the same ST. Two novel transposons were identified in isolates ZR9 and ZR18, of which approximately one third to half of the genes showed heterogenous origins compared with the usual intestinal bacterial genes. Most importantly,catD, known to be harbored by Tn4453a/b, was replaced byaac(6′) aph(2′′)in isolates 2, 7, and 28. This phenomenon illustrated the frequent occurrence of gene exchanges betweenC. difficileand other enterobacteria with individual heterogeneity. Numerous prophages and CRISPR arrays were identified inC. difficileisolates of clade 4. Approximately 20% of spacers were located in prophage-carried CRISPR arrays, providing a new method for typing and tracing the origins of closely related isolates, as well as in-depth studies of the mechanism underlying genome remodeling. The rates of drug resistance were obviously higher than those reported previously around the world, although all isolates retained high sensitivity to vancomycin and metronidazole. The increasing number ofC. difficileisolates resistant to all antibiotics tested here suggests the ease with which resistance is acquiredin vivo. This study gives insights into the genetic mechanism of microevolution within clade 4.IMPORTANCEMobile genetic elements play a key role in the continuing evolution ofClostridium difficile, resulting in the emergence of new phenotypes for individual isolates. On the basis of whole-genome sequencing analysis, we comprehensively explored transposons, CRISPR, prophage, and genetic sites for drug resistance within clade 4C. difficileisolates with different sequence types. Great diversity in MGEs and a high rate of multidrug resistance were found within this clade, including new transposons, Tn4453a/bwithaac(6′) aph(2′′)instead ofcatD, and a relatively high rate of prophage-carried CRISPR arrays. These findings provide important new insights into the mechanism of genome remodeling within clade 4 and offer a new method for typing and tracing the origins of closely related isolates.


mSphere ◽  
2017 ◽  
Vol 2 (4) ◽  
Author(s):  
S. Wesley Long ◽  
Sarah E. Linson ◽  
Matthew Ojeda Saavedra ◽  
Concepcion Cantu ◽  
James J. Davis ◽  
...  

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.


2014 ◽  
Vol 53 (1) ◽  
pp. 282-286 ◽  
Author(s):  
Erin P. Price ◽  
Derek S. Sarovich ◽  
Linda Viberg ◽  
Mark Mayo ◽  
Mirjam Kaestli ◽  
...  

TwelveBurkholderia pseudomalleiisolates collected over a 32-month period from a patient with chronic melioidosis demonstrated identical multilocus sequence types (STs). However, whole-genome sequencing suggests a polyclonal infection. This study is the first to report a mixed infection with the same ST.


2017 ◽  
Vol 56 (1) ◽  
Author(s):  
Aaron E. Lucas ◽  
Ryota Ito ◽  
Mustapha M. Mustapha ◽  
Christi L. McElheny ◽  
Roberta T. Mettus ◽  
...  

ABSTRACTFosfomycin maintains activity against mostEscherichia coliclinical isolates, but the growth ofE. colicolonies within the zone of inhibition around the fosfomycin disk is occasionally observed upon susceptibility testing. We aimed to estimate the frequency of such nonsusceptible inner colony mutants and identify the underlying resistance mechanisms. Disk diffusion testing of fosfomycin was performed on 649 multidrug-resistantE. coliclinical isolates collected between 2011 and 2015. For those producing inner colonies inside the susceptible range, the parental strains and their representative inner colony mutants were subjected to MIC testing, whole-genome sequencing, reverse transcription-quantitative PCR (qRT-PCR), and carbohydrate utilization studies. Of the 649E. coliclinical isolates, 5 (0.8%) consistently produced nonsusceptible inner colonies. Whole-genome sequencing revealed the deletion ofuhpTencoding hexose-6-phosphate antiporter in 4 of theE. coliinner colony mutants, while the remaining mutant contained a nonsense mutation inuhpA. The expression ofuhpTwas absent in the mutant strains withuhpTdeletion and was not inducible in the strain with theuhpAmutation, unlike in its parental strain. All 5 inner colony mutants had reduced growth on minimal medium supplemented with glucose-6-phosphate. In conclusion, fosfomycin-nonsusceptible inner colony mutants can occur due to the loss of function or induction of UhpT but are rare among multidrug-resistantE. coliclinical strains. Considering that these mutants carry high biological costs, we suggest that fosfomycin susceptibility of strains that generate inner colony mutants can be interpreted on the basis of the zone of inhibition without accounting for the inner colonies.


mBio ◽  
2018 ◽  
Vol 9 (2) ◽  
Author(s):  
Tom J. B. de Man ◽  
Joseph D. Lutgring ◽  
David R. Lonsway ◽  
Karen F. Anderson ◽  
Julia A. Kiehlbauch ◽  
...  

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.


2017 ◽  
Vol 61 (8) ◽  
Author(s):  
Racha Beyrouthy ◽  
Frederic Robin ◽  
Aude Lessene ◽  
Igor Lacombat ◽  
Laurent Dortet ◽  
...  

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.


2017 ◽  
Vol 62 (2) ◽  
Author(s):  
Bruno L. Abbadi ◽  
Anne D. Villela ◽  
Valnês S. Rodrigues-Junior ◽  
Fernanda T. Subtil ◽  
Pedro F. Dalberto ◽  
...  

ABSTRACT IQG-607 is a metal complex previously reported as a promising anti-tuberculosis (TB) drug against isoniazid (INH)-resistant strains of Mycobacterium tuberculosis. Unexpectedly, we found that INH-resistant clinical isolates were resistant to IQG-607. Spontaneous mutants resistant to IQG-607 were subjected to whole-genome sequencing, and all sequenced colonies carried alterations in the katG gene. The katG(S315T) mutation was sufficient to confer resistance to IQG-607 in both MIC assays and inside macrophages. Moreover, overexpression of the InhA(S94A) protein caused IQG-607's resistance.


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