The dissemination of carbapenem resistance in Escherichia coli has major implications for the management of common infections. bla KPC, encoding a transmissible carbapenemase (KPC), has historically largely been associated with Klebsiella pneumoniae, a predominant plasmid (pKpQIL), and a specific transposable element (Tn4401, ~10?kb). Here we characterize the genetic features of bla KPC emergence in global E. coli, 2008-2013, using both long- and short-read whole-genome sequencing. Amongst 43/45 successfully sequenced bla KPC-E. coli strains, we identified substantial strain diversity (n?=?21 sequence types, 18% of annotated genes in the core genome); substantial plasmid diversity (=9 replicon types); and substantial bla KPC-associated, mobile…
Objectives: Carbapenemase-producing Klebsiella pneumoniae pose an increasing risk for healthcare facilities worldwide. A continuous monitoring of ST distribution and its association with resistance and virulence genes is required for early detection of successful K. pneumoniae lineages. In this study, we used WGS to characterize MDR blaOXA-48-positive K. pneumoniae isolated from inpatients at the University Medical Center Göttingen, Germany, between March 2013 and August 2014. Methods: Closed genomes for 16 isolates of carbapenemase-producing K. pneumoniae were generated by single molecule real-time technology using the PacBio RSII platform. Results: Eight of the 16 isolates showed identical XbaI macrorestriction patterns and shared the…
Polymyxin is a cationic polypeptide antibiotic that can disrupt bacterial cell membrane by interacting with its lipopolysaccharide molecules and is used as a last resort drug against lethal infections by the carbapenem-resistant superbugs (like NDM-1). However, global discovery of the MCR-1 colistin resistance dramatically challenges the newly renewed interest in colistin for clinical use.The mcr-1-harboring plasmids were acquired from swine and human Escherichia coli isolated in China, from 2015 to 2016, and subjected to Illumina PacBio RSII and Hi-Seq2000 for full genome sequencing. PCR was applied to close the gap of the assembled contigs. Ori-Finder was employed to predict the…
Klebsiella pneumoniae is a major human pathogen responsible for high morbidity and mortality rates. The emergence and spread of strains resistant to multiple antimicrobial agents and documented large nosocomial outbreaks are especially concerning. To develop new therapeutic strategies for K. pneumoniae, it is imperative to understand the population genomic structure of strains causing human infections. To address this knowledge gap, we sequenced the genomes of 1,777 extended-spectrum beta-lactamase-producing K. pneumoniae strains cultured from patients in the 2,000-bed Houston Methodist Hospital system between September 2011 and May 2015, representing a comprehensive, population-based strain sample. Strains of largely uncharacterized clonal group 307 (CG307) caused…
We report here paired isogenic Burkholderia pseudomallei genomes obtained from three patients receiving intravenous meropenem for melioidosis treatment, with post-meropenem isolates developing decreased susceptibility. Two genomes were finished, and four were drafted to improved high-quality standard. These genomes will be used to identify meropenem resistance mechanisms in B. pseudomallei. Copyright © 2017 Price et al.
Polymyxin antibiotics are used as last-resort therapies to treat infections caused by multidrug-resistant Gram-negative bacteria. The plasmid-mediated colistin resistance determinant MCR-1 has been identified in Enterobacteriaceae in China. We did this study to investigate the prevalence of the mcr-1 gene in clinical isolates from patients with bloodstream infections in China.Clinical isolates of Escherichia coli and Klebsiella pneumoniae were collected from patients with bloodstream infections at 28 hospitals in China, then screened for colistin resistance by broth microdilution and for the presence of the mcr-1 gene by PCR amplification. We subjected mcr-1-positive isolates to genotyping, susceptibility testing, and clinical data analysis.…
The full-genome sequences of three drug- and multidrug-resistant Streptococcus pneumoniae clinical isolates of serotype 19A were determined by PacBio single-molecule real-time sequencing, in combination with Illumina MiSeq sequencing. A comparison to the genomes of other pneumococci indicates a high nucleotide sequence identity to strains Hungary19A-6 and TCH8431/19A. Copyright © 2017 Donner et al.
Myroides odoratimimus (M. odoratimimus) has been gradually implicated as an important nosocomial pathogen that poses a serious health threat to immunocompromised patients owing to its multi-drug resistance. However, the resistance mechanism is currently unclear. To clarify the antibiotic resistance and infectivity mechanisms of M. odoratimimus, whole genome sequencing was performed on the multi-drug-resistant M. odoratimimus strain PR63039. The genome sequence was completed with single molecule real-time (SMRT) technologies. Then, annotation was performed using RAST and IMG-ER. A number of databases and software programs were used to analyze the genomic characteristics, including GC-Profile, ISfinder, CG viewer, ARDB, CARD, ResFinder, the VFDB…
In tropical forests, rarer species show increased sensitivity to species-specific soil pathogens and more negative effects of conspecific density on seedling survival (NDD). These patterns suggest a connection between ecology and immunity, perhaps because small population size disproportionately reduces genetic diversity of hyperdiverse loci such as immunity genes. In an experiment examining seedling roots from six species in one tropical tree community, we found that smaller populations have reduced amino acid diversity in pathogen resistance (R) genes but not the transcriptome in general. Normalized R gene amino acid diversity varied with local abundance and prior measures of differences in sensitivity…
Whole-genome sequencing of Acinetobacter sp. strain NCu2D-2, isolated from the trachea of a mouse, revealed the presence of a plasmid of 309,964 bp with little overall similarity to known plasmids and enriched in insertion sequences (ISs) closely related to IS elements known from the nosocomial pathogen Acinetobacter baumannii. Copyright © 2017 Blaschke and Wilharm.
From 2012 to 2014, there has been a huge increase in vancomycin-resistant (vanA) Enterococcus faecium (VREfm) in Copenhagen, Denmark, with 602 patients infected or colonized with VREfm in 2014 compared with just 22 in 2012. The objective of this study was to describe the genetic epidemiology of VREfm to assess the contribution of clonal spread and horizontal transfer of the vanA transposon (Tn1546) and plasmid in the dissemination of VREfm in hospitals.VREfm from Copenhagen, Denmark (2012-14) were whole-genome sequenced. The clonal structure was determined and the structure of Tn1546-like transposons was characterized. One VREfm isolate belonging to the largest clonal…
Targeted capture provides an efficient and sensitive means for sequencing specific genomic regions in a high-throughput manner. To date, this method has mostly been used to capture exons from the genome (the exome) using short insert libraries and short-read sequencing technology, enabling the identification of genetic variants or new members of large gene families. Sequencing larger molecules results in the capture of whole genes, including intronic and intergenic sequences that are typically more polymorphic and allow the resolution of the gene structure of homologous genes, which are often clustered together on the chromosome. Here, we describe an improved method for…
Understanding the processes that shaped contemporary pathogen populations in agricultural landscapes is quite important to define appropriate management strategies and to support crop improvement efforts. Here, we took advantage of an historical record to examine the adaptation pathway of the rice pathogen Xanthomonas oryzae pv. oryzae (Xoo) in a semi-isolated environment represented in the Philippine archipelago. By comparing genomes of key Xoo groups we showed that modern populations derived from three Asian lineages. We also showed that diversification of virulence factors occurred within each lineage, most likely driven by host adaptation, and it was essential to shape contemporary pathogen races.…
The potato late blight resistance gene R8 has been cloned. R8 is found in five late blight resistant varieties deployed in three different continents. R8 recognises Avr8 and is homologous to the NB-LRR protein Sw-5 from tomato. The broad spectrum late blight resistance gene R8 from Solanum demissum was cloned based on a previously published coarse map position on the lower arm of chromosome IX. Fine mapping in a recombinant population and bacterial artificial chromosome (BAC) library screening resulted in a BAC contig spanning 170 kb of the R8 haplotype. Sequencing revealed a cluster of at least ten R gene analogues…
The blaIMP-14 carbapenem resistance gene has largely previously been observed in Pseudomonas aeruginosa and Acinetobacter spp. As part of global surveillance and sequencing of carbapenem-resistant E. coli, we identified an ST131 strain harboring blaIMP-14 within a class 1 integron, itself nested within a ~54kb multi-drug resistance region on an epidemic IncA/C2 plasmid. The emergence of blaIMP-14 in this context in the ST131 lineage is of potential clinical concern. Copyright © 2016 Stoesser et al.