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July 7, 2019

Complete genome sequence of Bacillus velezensis GQJK49, a plant growth-promoting rhizobacterium with antifungal activity.

Bacillus velezensis GQJK49 is a plant growth-promoting rhizobacterium with antifungal activity, which was isolated from Lycium barbarum L. rhizosphere. Here, we report the complete genome sequence of B. velezensis GQJK49. Twelve gene clusters related to its biosynthesis of secondary metabolites, including antifungal and antibacterial antibiotics, were predicted. Copyright © 2017 Ma et al.

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July 7, 2019

Complete genome sequence of the pathogenic Vibrio vulnificus type strain ATCC 27562.

Vibrio vulnificus has the highest death rate and economic burden per case of any foodborne pathogen in the United States. A complete genome sequence of the type strain promotes comparative analyses with other clinical and environmental isolates, improving our understanding of this important human pathogen and successful environmental organism. Copyright © 2017 Rusch and Rowe-Magnus.

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July 7, 2019

Whole-genome sequence of Chlamydia abortus strain GN6 isolated from aborted yak fetus.

The obligate intracellular Gram-negative bacterium Chlamydia abortus is one of the causative agents of abortion and fetal loss in sheep, goats, and cattle in many countries. It also affects the reproductivity of yaks (Bos grunniens). This study reports the whole-genome sequence of Chlamydia abortus strain GN6, which was isolated from aborted yak fetus in Qinghai-Tibetan Plateau, China. Copyright © 2017 Li et al.

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July 7, 2019

Rapid and affordable size-selected PacBio single-molecule real-time sequencing template library construction using the bead-beating DNA extraction method

This study demonstrated that bead-beating method facilitates a simple and rapid protocol for genomic DNA isolation for Pacific BioSciences (PacBio) sequencing with library construction of sufficient length. The protocol may also be beneficial for inactivating pathogens by simultaneous and instant DNA fragmentation, with no special equipment required to obtain large DNA fragments. This protocol was comparable in terms of quality to the standard protocol suggested by PacBioand represents an alternative, rapid shortcut for performing accurate PacBio sequencing.

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July 7, 2019

Genomics of Helicobacter pylori

As Helicobacter pylori infects half the world’s population and displays an extensive intraspecies diversity, genomics is a powerful tool to understand evolution and disease, to identify factors that confer higher risk of severe sequelae, and to find new approaches for therapy both among bacterial and host targets. In line with these objectives, this review article summarizes the major findings in Helicobacter genomics in papers published between April 2016 and March 2017.

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July 7, 2019

Novel multiresistance cfr plasmids in linezolid-resistant methicillin-resistant Staphylococcus epidermidis and vancomycin-resistant Enterococcus faecium (VRE) from a hospital outbreak: co-location of cfr and optrA in VRE.

Linezolid is often the drug of last resort to treat infections caused by Gram-positive cocci. Linezolid resistance can be mutational (23S rRNA or L-protein) or, less commonly, acquired [predominantly cfr, conferring resistance to phenicols, lincosamides, oxazolidinones, pleuromutilins and streptogramin A compounds (PhLOPSA) or optrA, encoding oxazolidinone and phenicol resistance].To investigate the clonality and genetic basis of linezolid resistance in 13 linezolid-resistant (LZDR) methicillin-resistant Staphylococcus epidermidis (MRSE) isolates recovered during a 2013/14 outbreak in an ICU in an Irish hospital and an LZDR vancomycin-resistant Enterococcus faecium (VRE) isolate from an LZDR-MRSE-positive patient.All isolates underwent PhLOPSA susceptibility testing, 23S rRNA sequencing, DNA microarray profiling and WGS.All isolates exhibited the PhLOPSA phenotype. The VRE harboured cfr and optrA on a novel 73?kb plasmid (pEF12-0805) also encoding erm(A), erm(B), lnu(B), lnu(E), aphA3 and aadE. One MRSE (M13/0451, from the same patient as the VRE) harboured cfr on a novel 8.5?kb plasmid (pSEM13-0451). The remaining 12 MRSE lacked cfr but exhibited linezolid resistance-associated mutations and were closely related to (1-52 SNPs) but distinct from M13/0451 (202-223 SNPs).Using WGS, novel and distinct cfr and cfr/optrA plasmids were identified in an MRSE and VRE isolate, respectively, as well as a cfr-negative LZDR-MRSE ICU outbreak and a distinct cfr-positive LZDR-MRSE from the same ICU. To our knowledge, this is the first report of cfr and optrA on a single VRE plasmid. Ongoing surveillance of linezolid resistance is essential to maintain its therapeutic efficacy.© The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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July 7, 2019

Quantitative proteomics for the comprehensive analysis of stress responses of Lactobacillus paracasei subsp. paracasei F19.

Lactic acid bacteria are broadly employed as starter cultures in the manufacture of foods. Upon technological preparation, they are confronted with drying stress that amalgamates numerous stress conditions resulting in losses of fitness and survival. To better understand and differentiate physiological stress responses, discover general and specific markers for the investigated stress conditions, and predict optimal preconditioning for starter cultures, we performed a comprehensive genomic and quantitative proteomic analysis of a commonly used model system, Lactobacillus paracasei subsp. paracasei TMW 1.1434 (isogenic with F19) under 11 typical stress conditions, including among others oxidative, osmotic, pH, and pressure stress. We identified and quantified >1900 proteins in triplicate analyses, representing 65% of all genes encoded in the genome. The identified genes were thoroughly annotated in terms of subcellular localization prediction and biological functions, suggesting unbiased and comprehensive proteome coverage. In total, 427 proteins were significantly differentially expressed in at least one condition. Most notably, our analysis suggests that optimal preconditioning toward drying was predicted to be alkaline and high-pressure stress preconditioning. Taken together, we believe the presented strategy may serve as a prototypic example for the analysis and utility of employing quantitative-mass-spectrometry-based proteomics to study bacterial physiology.

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July 7, 2019

Analysis of resistance genes in pan-resistant Myroides odoratimimus clinical strain PR63039 using whole genome sequencing.

To clarify the antibiotic resistance mechanisms of Myroides odoratimimus, pan-resistant M. odoratimimus strain PR63039 was isolated and its genome sequenced and analyzed. Antimicrobial susceptibility testing was conducted using the Kirby-Bauer disk diffusion method, and the Phoenix-100 Automated Microbiology System with a NMIC/ID-4 panel including aminoglycosides, ß-lactams, polypeptides, quinolones, sulfonamides, chloramphenicols, and tetracyclines. Single-molecule real-time whole genome sequencing was conducted using the PacBio RSII system, and genome annotation was performed using RAST and IMG ER. To characterize the genome features, a number of databases and software programs, including GC-Profile, CG viewer, the VFDB database, ISfinder, RADB, CARD, ResFinder, and PHAST, were used. M. odoratimimus isolate PR63039 was resistant to almost all antibiotics tested, suggesting pan-drug resistance. The genome consisted of a 4,366,950-bp chromosome and a 90,798-bp plasmid (p63039), which contained a large number of resistance genes and virulence factors. The distribution of the resistance genes was distinctive, and a resistance region, designated MY63039-RR, was identified. RAST analysis indicated that 108 of the annotated genes were potentially involved in virulence, disease, and defense, all of which could be associated with resistance and pathogenicity. Prophage analysis also identified two incomplete prophages in the genome of M. odoratimimus PR63039. Multiple antibiotic-resistance genes were identified, including those associated with resistance to tetracycline (tetX), macrolides (ereB, cfrA, lasE), sulfonamides (sul2, sul3), ß-lactams (blaMUS-1, blaTUS-1, blaSFB-1, blaSLB-1, blaOXA-209, blaOXA-347), and chloramphenicol (cat). Further, the presence of 18 antibiotic efflux pump-encoding resistance genes, including acrB, acrD, acrF, adeB, adeG, adeJ, amrB, ceoB, cmeB, mdsB, mexB, mexD, mexF, mtrD, smeE, mdtF, macB, likely accounts for the observed quinolone resistance of strain PR63039. To the best of our knowledge, this is the first report of the presence of the blaSFB-1, blaSLB-1, blaOXA-209, blaOXA-347, and tetX resistance genes in M. odoratimimus. Copyright © 2017 Elsevier Ltd. All rights reserved.

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July 7, 2019

Whole-genome sequencing identification of a multidrug-resistant Salmonella enterica serovar Typhimurium strain carrying blaNDM-5 from Guangdong, China.

A carbapenem-resistant Salmonella enterica serovar Typhimurium (sequence type 34 [ST34]) strain was isolated from a fecal specimen from a child with acute diarrhea. Whole-genome sequencing revealed that the 84.5-kb IncFII plasmid pST41-NDM carrying the NDM-5 carbapenemase gene possesses a structure identical to that of the IncFII-type plasmid backbone. However, the blaNDM-5 flanking sequence found in this plasmid is identical to the blaNDM-5-positive IncX3 plasmids carried by 10 strains of Enterobacteriaceae identified in the same hospital. Copyright © 2017 Elsevier B.V. All rights reserved.

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July 7, 2019

Comparative whole genome analysis of three consecutive Salmonella diarizonae isolates.

Infections of very young children or immunocompromised people with Salmonella of higher subspecies are a well-known phenomenon often associated with contact to cold-blooded animals. We describe the molecular characterization of three S. enterica subsp. diarizonae strains, isolated consecutively over a period of several months from a hospital patient suffering from diarrhea and sepsis with fatal outcome. With the initial isolate the first complete genome sequence of a member of subsp. diarizonae is provided and based on this reference we revealed the genomic differences between the three isolates by use of next-generation sequencing and confirmed by phenotypical tests. Genome comparisons revealed mutations within gpt, hfq and purK in the first isolate as a sign of clonal variation rather than host-directed evolution. Furthermore, our work demonstrates that S. enterica subsp. diarizonae possess, besides a conserved set of known Salmonella Pathogenicity Islands, a variable portfolio of additional genomic islands of unknown function. Copyright © 2017 Elsevier GmbH. All rights reserved.

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July 7, 2019

Comparative genomics of maize ear rot pathogens reveals expansion of carbohydrate-active enzymes and secondary metabolism backbone genes in Stenocarpella maydis.

Stenocarpella maydis is a plant pathogenic fungus that causes Diplodia ear rot, one of the most destructive diseases of maize. To date, little information is available regarding the molecular basis of pathogenesis in this organism, in part due to limited genomic resources. In this study, a 54.8 Mb draft genome assembly of S. maydis was obtained with Illumina and PacBio sequencing technologies, and analyzed. Comparative genomic analyses with the predominant maize ear rot pathogens Aspergillus flavus, Fusarium verticillioides, and Fusarium graminearum revealed an expanded set of carbohydrate-active enzymes for cellulose and hemicellulose degradation in S. maydis. Analyses of predicted genes involved in starch degradation revealed six putative a-amylases, four extracellular and two intracellular, and two putative ?-amylases, one of which appears to have been acquired from bacteria via horizontal transfer. Additionally, 87 backbone genes involved in secondary metabolism were identified, which represents one of the largest known assemblages among Pezizomycotina species. Numerous secondary metabolite gene clusters were identified, including two clusters likely involved in the biosynthesis of diplodiatoxin and chaetoglobosins. The draft genome of S. maydis presented here will serve as a useful resource for molecular genetics, functional genomics, and analyses of population diversity in this organism. Copyright © 2017 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

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July 7, 2019

Genomic insights of Pannonibacter phragmitetus strain 31801 isolated from a patient with a liver abscess.

Pannonibacter phragmitetus is a bioremediation reagent for the detoxification of heavy metals and polycyclic aromatic compounds (PAHs) while it rarely infects healthy populations. However, infection by the opportunistic pathogen P. phragmitetus complicates diagnosis and treatments, and poses a serious threat to immunocompromised patients owing to its multidrug resistance. Unfortunately, genome features, antimicrobial resistance, and virulence potentials in P. phragmitetus have not been reported before. A predominant colony (31801) was isolated from a liver abscess patient, indicating that it accounted for the infection. To investigate its infection mechanism(s) in depth, we sequenced this bacterial genome and tested its antimicrobial resistance. Average nucleotide identity (ANI) analysis assigned the bacterium to the species P. phragmitetus (ANI, >95%). Comparative genomics analyses among Pannonibacter spp. representing the different living niches were used to describe the Pannonibacter pan-genomes and to examine virulence factors, prophages, CRISPR arrays, and genomic islands. Pannonibacter phragmitetus 31801 consisted of one chromosome and one plasmid, while the plasmid was absent in other Pannonibacter isolates. Pannonibacter phragmitetus 31801 may have a great infection potential because a lot of genes encoding toxins, flagellum formation, iron uptake, and virulence factor secretion systems in its genome. Moreover, the genome has 24 genomic islands and 2 prophages. A combination of antimicrobial susceptibility tests and the detailed antibiotic resistance gene analysis provide useful information about the drug resistance mechanisms and therefore can be used to guide the treatment strategy for the bacterial infection.© 2017 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

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July 7, 2019

Harnessing whole genome sequencing in medical mycology.

Comparative genome sequencing studies of human fungal pathogens enable identification of genes and variants associated with virulence and drug resistance. This review describes current approaches, resources, and advances in applying whole genome sequencing to study clinically important fungal pathogens.Genomes for some important fungal pathogens were only recently assembled, revealing gene family expansions in many species and extreme gene loss in one obligate species. The scale and scope of species sequenced is rapidly expanding, leveraging technological advances to assemble and annotate genomes with higher precision. By using iteratively improved reference assemblies or those generated de novo for new species, recent studies have compared the sequence of isolates representing populations or clinical cohorts. Whole genome approaches provide the resolution necessary for comparison of closely related isolates, for example, in the analysis of outbreaks or sampled across time within a single host.Genomic analysis of fungal pathogens has enabled both basic research and diagnostic studies. The increased scale of sequencing can be applied across populations, and new metagenomic methods allow direct analysis of complex samples.

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July 7, 2019

Complete genetic analysis of a Salmonella enterica serovar Indiana isolate accompanying four plasmids carrying mcr-1, ESBL and other resistance genes in China

One mcr-1-carrying Salmonella enterica serovar Indiana strain D90, was identified from 1320 Salmonella enterica isolates from poultry slaughterhouse in 2012 in China. The objective of this study was to verify the transferability of the mcr-1 gene and also completely characterize the sequence of the strain at the whole-genome level. Broth matting assays were carried out to detect the transferability and whole-genome sequencing (WGS) of S. enterica serovar Indiana D90 was performed using the PacBio RS II system. Open reading frames were assigned using Rapid Annotation using Subsystem Technology (RAST) and analysed by BLASTn and BLASTp. Salmonella Pathogenisity Islands (SPIs) were annotated by SPIFinder platform. The complete genome sequence of S. enterica serovar Indiana D90 contained a circular 4,779,514-bp chromosome and four plasmids. Genome analysis and sequencing revealed that 24 multi-drug resistance (MDR) genes were located on plasmids. The largest plasmid pD90-1, was found to be of an IncHI2/HI2A/Q1/N type that encoded a blaCTX-M-65 gene along with 20 additional antimicrobial resistance genes. A 60.5-kbp IncI2 plasmid pD90-2 contained a nikA-nikB-mcr-1 genetic structure, that can be successfully transferred to E. coli and S. enterica serovar Typhimurium at low transfer rates. Interestingly, comparative sequence analysis revealed the plasmids pD90-1 and pD90-2 showed considerable nucleotide similarity to pHNSHP45-2 and pHNSHP45, respectively. Moreover, the genome and the plasmid pD90-2 also showed high similarity to one carbapenem resistant S. enterica serovar Indiana strain, C629 and its plasmid pC629, respectively. This is the first report of the complete nucleotide sequence of one mcr-1-carrying MDR S. enterica serovar Indiana strain.

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