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July 7, 2019

Escherichia coli harboring mcr-1 and blaCTX-M on a novel IncF plasmid: first report of mcr-1 in the United States.

The recent discovery of a plasmid-borne colistin resistance gene, mcr-1, in China heralds the emergence of truly pan-drug-resistant bacteria (1). The gene has been found primarily in Escherichia coli but has also been identified in other members of the Enterobacteriaceae in human, animal, food, and environmental samples on every continent (2–5). In response to this threat, starting in May 2016, all extended-spectrum-ß-lactamase (ESBL)-producing E. coli clinical isolates submitted to the clinical microbiology laboratory at the Walter Reed National Military Medical Center (WRNMMC) have been tested for resistance to colistin by Etest. Here we report the presence of mcr-1 in an E. coli strain cultured from a patient with a urinary tract infection (UTI) in the United States. The strain was resistant to colistin, but it remained susceptible to several other agents, including amikacin, piperacillin-tazobactam, all carbapenems, and nitrofurantoin (Table 1).


July 7, 2019

Complete and closed genome sequences of 10 Salmonella enterica subsp. enterica serovar Anatum isolates from human and bovine sources.

Salmonella enterica is an important pathogen transmitted by numerous vectors. Genomic comparisons of Salmonella strains from disparate hosts have the potential to further our understanding of mechanisms underlying host specificities and virulence. Here, we present the closed genome and plasmid sequences of 10 Salmonella enterica subsp. enterica serovar Anatum isolates from bovine and human sources. Copyright © 2016 Nguyen et al.


July 7, 2019

The rubber tree genome shows expansion of gene family associated with rubber biosynthesis.

Hevea brasiliensis Muell. Arg, a member of the family Euphorbiaceae, is the sole natural resource exploited for commercial production of high-quality natural rubber. The properties of natural rubber latex are almost irreplaceable by synthetic counterparts for many industrial applications. A paucity of knowledge on the molecular mechanisms of rubber biosynthesis in high yield traits still persists. Here we report the comprehensive genome-wide analysis of the widely planted H. brasiliensis clone, RRIM 600. The genome was assembled based on ~155-fold combined coverage with Illumina and PacBio sequence data and has a total length of 1.55?Gb with 72.5% comprising repetitive DNA sequences. A total of 84,440 high-confidence protein-coding genes were predicted. Comparative genomic analysis revealed strong synteny between H. brasiliensis and other Euphorbiaceae genomes. Our data suggest that H. brasiliensis’s capacity to produce high levels of latex can be attributed to the expansion of rubber biosynthesis-related genes in its genome and the high expression of these genes in latex. Using cap analysis gene expression data, we illustrate the tissue-specific transcription profiles of rubber biosynthesis-related genes, revealing alternative means of transcriptional regulation. Our study adds to the understanding of H. brasiliensis biology and provides valuable genomic resources for future agronomic-related improvement of the rubber tree.


July 7, 2019

Expression and purification of the modification-dependent restriction enzyme BisI and its homologous enzymes.

The methylation-dependent restriction endonuclease (REase) BisI (G(m5)C???NGC) is found in Bacillus subtilis T30. We expressed and purified the BisI endonuclease and 34 BisI homologs identified in bacterial genomes. 23 of these BisI homologs are active based on digestion of (m5)C-modified substrates. Two major specificities were found among these BisI family enzymes: Group I enzymes cut GCNGC containing two to four (m5)C in the two strands, or hemi-methylated sites containing two (m5)C in one strand; Group II enzymes only cut GCNGC sites containing three to four (m5)C, while one enzyme requires all four cytosines to be modified for cleavage. Another homolog, Esp638I cleaves GCS???SGC (relaxed specificity RCN???NGY, containing at least four (m5)C). Two BisI homologs show degenerate specificity cleaving unmodified DNA. Many homologs are small proteins ranging from 150 to 190 amino acid (aa) residues, but some homologs associated with mobile genetic elements are larger and contain an extra C-terminal domain. More than 156 BisI homologs are found in >60 bacterial genera, indicating that these enzymes are widespread in bacteria. They may play an important biological function in restricting pre-modified phage DNA.


July 7, 2019

Complete genome sequence of the first KPC-type carbapenemase-positive Proteus mirabilis strain from a bloodstream infectio

Sequencing of the blaKPC-positive strain Proteus mirabilis AOUC-001 was performed using both the MiSeq and PacBio RS II platforms and yielded a single molecule of 4,272,433 bp, representing the complete chromosome. Genome analysis showed the presence of several acquired resistance determinants, including two copies of blaKPC-2 carried on a fragment of a KPC-producing plasmid previously described in Klebsiella pneumoniae. Copyright © 2016 Di Pilato et al.


July 7, 2019

Draft genome sequences of two strains of Paenibacillus glucanolyticus with the ability to degrade lignocellulose.

Paenibacillus glucanolyticus 5162, a bacterium isolated from soil, and Paenibacillus glucanolyticus SLM1, a bacterium isolated from pulp mill waste, can utilize cellulose, hemicellulose and lignin as sole carbon sources for growth. These two strains of Paenibacillus glucanolyticus were sequenced using PacBio and Illumina MiSeq technologies. Copyright © 2016 Mathews et al.


July 7, 2019

Complete genome sequence of a multidrug-resistant Acinetobacter baumannii isolate obtained from a Mexican hospital (sequence type 422).

Acinetobacter baumannii has emerged as a dangerous nosocomial pathogen, particularly for severely ill patients in intensive care units and patients with hematologic malignancies. Here, we present the complete genome sequence of a multidrug-resistant A. baumannii isolate, recovered from a Mexican hospital and classified as sequence type 422 according to the multilocus sequence typing Pasteur scheme. Copyright © 2016 Castro-Jaimes et al.


July 7, 2019

Complete genome sequence of Vibrio vulnificus FORC_017 isolated from a patient with a hemorrhagic rash after consuming raw dotted gizzard shad.

Vibrio vulnificus, a resident in the human gut, is frequently found in seafood, causing food-borne illnesses including gastroenteritis and severe septicemia. While V. vulnificus has been known to be one of the major food-borne pathogens, pathogenicity and virulence factors are not fully understood yet. To extend our understanding of the pathogenesis of V. vulnificus at the genomic level, the genome of V. vulnificus FORC_017 isolated from a female patient experiencing a hemorrhagic rash was completely sequenced and analyzed.Three discontinuous contigs were generated from a hybrid assembly using Illumina MiSeq and PacBio platforms, revealing that the genome of the FORC_017 consists of two circular chromosomes and a plasmid. Chromosome I consists of 3,253,417-bp (GC content 46.49 %) containing 2943 predicted open reading frames (ORFs) and chromosome II of 1,905,745-bp (GC content 46.90 %) containing 1638 ORFs. The plasmid pFORC17 consists of 70,069-bp (GC content 43.77 %) containing 84 ORFs. The average nucleotide identity (ANI) value of the FORC_017 and CMCP6 strains was 98.53, suggesting that they are closely related.Pathogenesis-associated genes including vvhA, rtx gene cluster, and various hemolysin genes were present in FORC_017. In addition, three complete secretion systems (Type I, II and VI) as well as iron uptake-related genes for virulence of the FORC_017 were detected, suggesting that this strain is pathogenic. Further comparative genome analysis revealed that FORC_017 and CMCP6 share major toxin genes including vvhA and rtx for pathogenesis activities. The genome information of the FORC_017 provides novel insights into pathogenicity and virulence factors of V. vulnificus.


July 7, 2019

Complete genome sequence of Wohlfahrtiimonas chitiniclastica strain BM-Y, isolated from the pancreas of a zebra in China.

Here, a complete genome sequence of Wohlfahrtiimonas chitiniclastica strain BM-Y is presented. The whole genome is 2.18-Mb and contains a blaVEB-1 gene cassette which endows it with resistance to ceftazidime, ampicillin, tetracycline, etc. To our knowledge, this is the first time that an extended spectrum beta-lactamase (ESBL) type W. chitiniclastica strain has been found. Copyright © 2016 Zhou et al.


July 7, 2019

Complete genome sequence of Enterococcus hirae R17, a daptomycin-resistant bacterium isolated from retail pork in China.

Daptomycin-resistant Enterococcus hirae R17 was isolated from retail pork sold at a free-trade market in Beijing, China. The complete genome sequence of R17 contains a circular 2,886,481-bp chromosome and a circular 73,574-bp plasmid. Genes involved in cell envelope homeostasis of this bacterium were identified by whole-genome analysis. Copyright © 2016 Peng et al.


July 7, 2019

Chloroplast genomes: diversity, evolution, and applications in genetic engineering.

Chloroplasts play a crucial role in sustaining life on earth. The availability of over 800 sequenced chloroplast genomes from a variety of land plants has enhanced our understanding of chloroplast biology, intracellular gene transfer, conservation, diversity, and the genetic basis by which chloroplast transgenes can be engineered to enhance plant agronomic traits or to produce high-value agricultural or biomedical products. In this review, we discuss the impact of chloroplast genome sequences on understanding the origins of economically important cultivated species and changes that have taken place during domestication. We also discuss the potential biotechnological applications of chloroplast genomes.


July 7, 2019

A commensal bacterium promotes virulence of an opportunistic pathogen via cross-respiration.

Bacteria rarely inhabit infection sites alone, instead residing in diverse, multispecies communities. Despite this fact, bacterial pathogenesis studies primarily focus on monoculture infections, overlooking how community interactions influence the course of disease. In this study, we used global mutant fitness profiling (transposon sequencing [Tn-seq]) to determine the genetic requirements for the pathogenic bacterium Aggregatibacter actinomycetemcomitans to cause disease when coinfecting with the commensal bacterium Streptococcus gordonii Our results show that S. gordonii extensively alters A. actinomycetemcomitans requirements for virulence factors and biosynthetic pathways during infection. In addition, we discovered that the presence of S. gordonii enhances the bioavailability of oxygen during infection, allowing A. actinomycetemcomitans to shift from a primarily fermentative to a respiratory metabolism that enhances its growth yields and persistence. Mechanistically, respiratory metabolism enhances the fitness of A. actinomycetemcomitans in vivo by increasing ATP yields via central metabolism and creating a proton motive force. Our results reveal that, similar to cross-feeding, where one species provides another species with a nutrient, commensal bacteria can also provide electron acceptors that promote the respiratory growth and fitness of pathogens in vivo, an interaction that we term cross-respiration.Commensal bacteria can enhance the virulence of pathogens in mixed-species infections. However, knowledge of the mechanisms underlying this clinically relevant phenomenon is lacking. To bridge this gap, we comprehensively determined the genes a pathogen needs to establish coinfection with a commensal. Our findings show that the metabolism of the pathogen is low-energy-yielding in monoinfection, but in coinfection, the commensal improves the fitness of the pathogen by increasing the bioavailability of oxygen, thereby shifting the pathogen toward a high-energy-yielding metabolism. Similar to cross-feeding, this interaction, which we term cross-respiration, illustrates that commensal bacteria can provide electron acceptors that enhance the virulence of pathogens during infection. Copyright © 2016 Stacy et al.


July 7, 2019

The draft genome of MD-2 pineapple using hybrid error correction of long reads.

The introduction of the elite pineapple variety, MD-2, has caused a significant market shift in the pineapple industry. Better productivity, overall increased in fruit quality and taste, resilience to chilled storage and resistance to internal browning are among the key advantages of the MD-2 as compared with its previous predecessor, the Smooth Cayenne. Here, we present the genome sequence of the MD-2 pineapple (Ananas comosus (L.) Merr.) by using the hybrid sequencing technology from two highly reputable platforms, i.e. the PacBio long sequencing reads and the accurate Illumina short reads. Our draft genome achieved 99.6% genome coverage with 27,017 predicted protein-coding genes while 45.21% of the genome was identified as repetitive elements. Furthermore, differential expression of ripening RNASeq library of pineapple fruits revealed ethylene-related transcripts, believed to be involved in regulating the process of non-climacteric pineapple fruit ripening. The MD-2 pineapple draft genome serves as an example of how a complex heterozygous genome is amenable to whole genome sequencing by using a hybrid technology that is both economical and accurate. The genome will make genomic applications more feasible as a medium to understand complex biological processes specific to pineapple. © The Author 2016. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.


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