The study of mycobiota remains relatively unexplored due to the lack of sufficient available reference strains and databases compared to those of bacterial microbiome studies. Deep sequencing of Internal Transcribed Spacer (ITS) regions is the de facto standard for fungal diversity analysis. However, results are often biased because of the wide variety of sequence lengths in the ITS regions and the complexity of high-throughput sequencing (HTS) technologies. In this study, a curated ITS database, ntF-ITS1, was constructed. This database can be utilized for the taxonomic assignment of fungal community members. We evaluated the efficacy of strategies for mycobiome analysis by…
Genetic and phenotypic diversity are the basis of evolution. Despite their importance, however, little is known about how they change over the course of evolution. In this study, we analyzed the dynamics of the adaptive evolution of a simple evolvable artificial cell-like system using single-molecule real-time sequencing technology that reads an entire single artificial genome. We found that the genomic RNA population increases in fitness intermittently, correlating with a periodic pattern of genetic and fitness diversity produced by repeated diversification and domination. In the diversification phase, a genomic RNA population spreads within a genetic space by accumulating mutations until mutants…
Although KPC enzymes are most common among carbapenemases produced by Enterobacter cloacae complex globally, the epidemiology varies from one country to another. While previous studies have suggested that IMP enzymes are most common in Japan, detailed analysis has been scarce thus far. Here, we carried out a molecular epidemiological study and plasmid analysis of IMP-1-producing E. cloacae complex isolates collected from three hospitals in central Tokyo using whole-genome sequencing. Seventy-one isolates were classified into several sequence types (STs), and 49 isolates were identified as Enterobacter hormaechei ST78. Isolates of ST78 were divided into three clades by core-genome single nucleotide polymorphism…
Post-mortem detection of pathogenetic microorganisms in severe infectious death is significantly important for diagnosing the cause of death as well as for public health. However, it is difficult to recognize whether a microorganism detected from post-mortem materials is truly pathogenic or not. We report a case of severe soft tissue infection due to Streptococcus oralis subsp. tigurinus (S. tigurinus), a recently reported species, in which whole-genome analysis was performed to clarify its pathogenicity. A 46-year-old woman had died with symptoms of a severe infectious disease. A post-mortem examination was performed by a medical examiner. The external findings suggested a soft…
Colistin is indicated for the treatment of multidrug-resistant gram-negative bacterial infections. However, the spread of colistin-resistant bacteria harbouring an mcr gene has become a serious concern. This study investigated local foods in Vietnam for contamination with colistin-resistant bacteria. A total of 261 extended-spectrum ß-lactamase (ESBL)- and AmpC-producing Escherichia coli isolates from 330 meat and seafood products were analysed for colistin susceptibility and the presence of mcr genes. Approximately, 24% (62/261) of ESBL- or AmpC-producing E. coli isolates showed colistin resistance; 97% (60/62) of colistin-resistant isolates harboured mcr-1, whereas 3% (2/62) harboured mcr-3. As the result of plasmid analysis of two…
The spread of carbapenemase-producing Enterobacteriaceae (CPE) is an increasing global public health concern. The development of simple and reliable methods for CPE detection is required in the clinical setting. This study aimed to establish a dual-wavelength measurement method using an ultraviolet-visible spectrophotometer to rapidly quantify imipenem hydrolysis in bacterial cell suspensions. The hydrolytic activities of 148 strains including various CPE strains (Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, and Enterobacter aerogenes containing the blaIMP, blaKPC, blaNDM, blaOXA, and blaVIM genes) were measured and analysed. A cut-off value was obtained for differentiation between CPE and non-CPE strains, and the method had high…
To investigate the molecular changes needed for cells to maintain their telomeres by recombination, we monitored telomere appearance during serial culture of fission yeast cells lacking the telomerase recruitment factor Ccq1. Rad52 is loaded onto critically short telomeres shortly after germination despite continued telomere erosion, suggesting that recruitment of recombination factors is not sufficient to maintain telomeres in the absence of telomerase function. Instead, survivor formation coincides with the derepression of telomeric repeat-containing RNA (TERRA). Degradation of telomere-associated TERRA in this context drives a severe growth crisis, ultimately leading to a distinct type of linear survivor with altered cytological telomere…
We report here Klebsiella pneumoniae strains carrying chromosomal blaNDM-1 in Thailand. The genomes of these two isolates include a 160-kbp insertion containing blaNDM-1, which is almost identical to that in the IncHI1B-like plasmid. Further analysis indicated that IS5-mediated intermolecular transposition and Tn3 transposase-mediated homologous recombination resulted in the integration of blaNDM-1 into the chromosome from an IncHI1B-like plasmid. The spread of this type of carbapenem-resistant Enterobacteriaceae may threaten public health and warrants further monitoring. Copyright © 2018 American Society for Microbiology.
The availability of diverse second- and third-generation sequencing technologies enables the rapid determination of the sequences of bacterial genomes. However, identifying the sequencing technology most suitable for producing a finished genome with multiple chromosomes remains a challenge. We evaluated the abilities of the following three second-generation sequencers: Roche 454 GS Junior (GS Jr), Life Technologies Ion PGM (Ion PGM), and Illumina MiSeq (MiSeq) and a third-generation sequencer, the Pacific Biosciences RS sequencer (PacBio), by sequencing and assembling the genome of Vibrio parahaemolyticus, which consists of a 5-Mb genome comprising two circular chromosomes. We sequenced the genome of V. parahaemolyticus with…
Here, we present the complete genome sequence of Ureaplasma parvum serovar 3, clinical strain SV3F4, isolated from a Japanese patient with a history of an infectious abortion. Copyright © 2014 Wu et al.
Chinese liquorice/licorice (Glycyrrhiza uralensis) is a leguminous plant species whose roots and rhizomes have been widely used as a herbal medicine and natural sweetener. Whole-genome sequencing is essential for gene discovery studies and molecular breeding in liquorice. Here, we report a draft assembly of the approximately 379-Mb whole-genome sequence of strain 308-19 of G. uralensis; this assembly contains 34 445 predicted protein-coding genes. Comparative analyses suggested well-conserved genomic components and collinearity of gene loci (synteny) between the genome of liquorice and those of other legumes such as Medicago and chickpea. We observed that three genes involved in isoflavonoid biosynthesis, namely, 2-hydroxyisoflavanone…
We present here three complete genome sequences of Mycobacterium tuberculosis Beijing family strains isolated in Hanoi, Vietnam. These three strains were selected from major genotypic clusters (15-MIRU-VNTR) identified in a previous population-based study. We emphasize their importance and potential as reference strains in this Asian region. Copyright © 2017 Wada et al.
Plasmodium gonderi is a primate parasite whose natural host is the African Old World monkeys. Here, we report the draft genome sequence for P. gonderi The data are useful not only for understanding the evolution of malaria but also for allowing the comparative genomics of malaria parasites. Copyright © 2017 Honma et al.
Vibrio parahaemolyticus is a causative agent of acute hapatopancreatic necrosis syndrome (AHPNS) which causes early mortality in white shrimp. Emergence of AHPNS has caused tremendous economic loss for aquaculture industry particularly in Asia since 2010. Previous studies reported that strains causing AHPNS harbor a 69-kb plasmid with possession of virulence genes, pirA and pirB. However, genetic variation of the 69-kb plasmid among AHPNS related strains has not been investigated. This study aimed to analyze genetic composition and diversity of the 69-kb plasmid in strains isolated from shrimps affected by AHPNS. Plasmids recovered from V. parahaemolyticus strain VPE61 which represented typical…
miR-122, a liver-specific microRNA, is one of the determinants for liver tropism of hepatitis C virus (HCV) infection. Although miR-122 is required for efficient propagation of HCV, we have previously shown that HCV replicates at a low rate in miR-122-deficient cells, suggesting that HCV-RNA is capable of propagating in an miR-122-independent manner. We herein investigated the roles of miR-122 in both the replication of HCV-RNA and the production of infectious particles by using miR-122-knockout Huh7 (Huh7-122KO) cells. A slight increase of intracellular HCV-RNA levels and infectious titers in the culture supernatants was observed in Huh7-122KO cells upon infection with HCV.…