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1.
Bioinformatics ; 38(18): 4286-4292, 2022 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-35876544

RESUMO

MOTIVATION: Microbiota analyses have important implications for health and science. These analyses make use of 16S/18S rRNA gene sequencing to identify taxa and predict species diversity. However, most available tools for analyzing microbiota data require adept programming skills and in-depth statistical knowledge for proper implementation. While long-read amplicon sequencing can lead to more accurate taxa predictions and is quickly becoming more common, practitioners have no easily accessible tools with which to perform their analyses. RESULTS: We present MOCHI, a GUI tool for microbiota amplicon sequencing analysis. MOCHI preprocesses sequences, assigns taxonomy, identifies different abundant species and predicts species diversity and function. It takes either taxonomic count table or FASTQ of partial 16S/18S rRNA or full-length 16S rRNA gene as input. It performs analyses in real time and visualizes data in both tabular and graphical formats. AVAILABILITY AND IMPLEMENTATION: MOCHI can be installed to run locally or accessed as a web tool at https://mochi.life.nctu.edu.tw. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala , Microbiota , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Microbiota/genética , Filogenia
2.
BMC Med ; 19(1): 59, 2021 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-33627136

RESUMO

BACKGROUND: Long noncoding (lnc)RNAs and glycolysis are both recognized as key regulators of cancers. Some lncRNAs are also reportedly involved in regulating glycolysis metabolism. However, glycolysis-associated lncRNA signatures and their clinical relevance in cancers remain unclear. We investigated the roles of glycolysis-associated lncRNAs in cancers. METHODS: Glycolysis scores and glycolysis-associated lncRNA signatures were established using a single-sample gene set enrichment analysis (GSEA) of The Cancer Genome Atlas pan-cancer data. Consensus clustering assays and genomic classifiers were used to stratify patient subtypes and for validation. Fisher's exact test was performed to investigate genomic mutations and molecular subtypes. A differentially expressed gene analysis, with GSEA, transcription factor (TF) activity scoring, cellular distributions, and immune cell infiltration, was conducted to explore the functions of glycolysis-associated lncRNAs. RESULTS: Glycolysis-associated lncRNA signatures across 33 cancer types were generated and used to stratify patients into distinct clusters. Patients in cluster 3 had high glycolysis scores and poor survival, especially in bladder carcinoma, low-grade gliomas, mesotheliomas, pancreatic adenocarcinomas, and uveal melanomas. The clinical significance of lncRNA-defined groups was validated using external datasets and genomic classifiers. Gene mutations, molecular subtypes associated with poor prognoses, TFs, oncogenic signaling such as the epithelial-to-mesenchymal transition (EMT), and high immune cell infiltration demonstrated significant associations with cluster 3 patients. Furthermore, five lncRNAs, namely MIR4435-2HG, AC078846.1, AL157392.3, AP001273.1, and RAD51-AS1, exhibited significant correlations with glycolysis across the five cancers. Except MIR4435-2HG, the lncRNAs were distributed in nuclei. MIR4435-2HG was connected to glycolysis, EMT, and immune infiltrations in cancers. CONCLUSIONS: We identified a subgroup of cancer patients stratified by glycolysis-associated lncRNAs with poor prognoses, high immune infiltration, and EMT activation, thus providing new directions for cancer therapy.


Assuntos
Regulação Neoplásica da Expressão Gênica/imunologia , Glicólise/imunologia , MicroRNAs/imunologia , RNA Longo não Codificante/genética , Microambiente Tumoral/imunologia , Feminino , Humanos , Masculino
3.
J Antimicrob Chemother ; 76(2): 312-321, 2021 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-33128052

RESUMO

OBJECTIVES: Acinetobacter seifertii, a new member of the Acinetobacter baumannii group, has emerged as a cause of severe infections in humans. We investigated the clinical and molecular characteristics of A. seifertii. PATIENTS AND METHODS: This retrospective study enrolled 80 adults with A. seifertii bloodstream infection (BSI) at four medical centres over an 8 year period. Species identification was confirmed by MALDI-TOF MS, rpoB sequencing and WGS. Molecular typing was performed by MLST. Clinical information, antimicrobial susceptibility and the mechanisms of carbapenem and colistin resistance were analysed. Transmissibility of the carbapenem-resistance determinants was examined by conjugation experiments. RESULTS: The main source of A. seifertii BSI was the respiratory tract (46.3%). The 28 day and in-hospital mortality rates of A. seifertii BSI were 18.8% and 30.0%, respectively. High APACHE II scores and immunosuppressant therapy were independent risk factors for 28 day mortality. The most common MLST type was ST553 (58.8%). Most A. seifertii isolates were susceptible to levofloxacin (86.2%), and only 37.5% were susceptible to colistin. Carbapenem resistance was observed in 16.3% of isolates, mostly caused by the plasmid-borne ISAba1-blaOXA-51-like genetic structure. A. seifertii could transfer various carbapenem-resistance determinants to A. baumannii, Acinetobacter nosocomialis and other A. seifertii isolates. Variations of pmrCAB and lpxCAD genes were not associated with colistin resistance of A. seifertii. CONCLUSIONS: Levofloxacin and carbapenems, but not colistin, have the potential to be the drug of choice for A. seifertii infections. A. seifertii can transfer carbapenem-resistance determinants to other species of the A. baumannii group and warrants close monitoring.


Assuntos
Infecções por Acinetobacter , Acinetobacter baumannii , Acinetobacter , Acinetobacter/genética , Infecções por Acinetobacter/epidemiologia , Acinetobacter baumannii/genética , Adulto , Antibacterianos/farmacologia , Humanos , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Estudos Retrospectivos , Taiwan/epidemiologia , beta-Lactamases
4.
Ann Surg Oncol ; 28(2): 920-929, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32705512

RESUMO

BACKGROUND: After the publication of the Z0011 trial, the American Society of Clinical Oncology published an updated clinical practice guideline stating that clinicians should not recommend axillary lymph node dissection (ALND) for early-stage breast cancer patients with the involvement of one or two sentinel lymph nodes (SLNs). However, these recommendations have been challenged because they were mainly based on data from limited studies. The aim of the current study is to systematically compare the real-world outcomes of SLN biopsy (SLNB) alone and SLNB + ALND in patients with early-stage breast cancers and limited positive SLN metastasis in the post-Z0011 era PATIENTS AND METHODS: We searched articles in the PubMed, EMBASE, and Cochrane library databases. The primary endpoints were overall survival (OS) and disease-free survival (DFS). The secondary endpoints were recurrence rate and the incidence of lymphedema. RESULTS: One randomized controlled trial and six retrospective studies with 8864 patients were retrieved. For patients with early-stage breast cancer with one or two SLN metastases, receiving SLNB alone showed no significant difference in OS, DFS, and recurrence rate compared with receiving SLNB + ALND. The incidence of lymphedema in patients who received SLNB alone was significantly lower than those who received SLNB + ALND (odds ratio 1.95, 95% confidence interval 1.02-3.71). CONCLUSIONS: Current real-world evidence proved that the Z0011 strategy is safe with respect to survival outcomes and effective in reducing the incidence of lymphedema. ALND should be avoided in patients with early-stage breast cancer with one or two SLN metastases in the post-Z0011 era.


Assuntos
Neoplasias da Mama , Linfonodo Sentinela , Axila , Neoplasias da Mama/cirurgia , Feminino , Humanos , Excisão de Linfonodo , Recidiva Local de Neoplasia , Ensaios Clínicos Controlados Aleatórios como Assunto , Estudos Retrospectivos , Linfonodo Sentinela/cirurgia , Biópsia de Linfonodo Sentinela
5.
J Antimicrob Chemother ; 75(2): 309-317, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31702790

RESUMO

OBJECTIVES: Emergent antimicrobial-resistant hypervirulent Klebsiella pneumoniae (hvKp) is an important public health issue. We aimed to investigate resistance mechanisms and hypervirulent traits among tigecycline-non-susceptible (TNS) K. pneumoniae clinical strains, focusing on one hvKp strain with in vivo evolution of tigecycline resistance. METHODS: TNS K. pneumoniae strains causing invasive diseases in a medical centre in Taiwan between July 2015 and April 2018 were collected. Resistance mechanisms were determined and hvKp strains were defined as rmpA/rmpA2-carrying strains. Isogenic strains with and without tigecycline resistance were subjected to WGS and in vivo virulence testing. Further, site-directed mutagenesis was used to confirm the resistance mechanism. RESULTS: In total, 31 TNS K. pneumoniae strains were isolated, including six hypervirulent strains. Tigecycline resistance mechanisms were mostly caused by overexpression of AcrAB and OqxAB together with up-regulation of RamA or RarA, respectively. One TNS hypervirulent strain (KP1692; MIC=6 mg/L) derived from its tigecycline-susceptible counterpart (KP1677; MIC=0.75 mg/L) showed acrAB overexpression. WGS revealed four genetic variations between KP1677 and KP1692. In addition, using site-directed mutagenesis, we confirmed that a 1 bp insertion in the ramA upstream region (RamR-binding site), leading to ramA and acrAB overexpression in KP1692, was responsible for tigecycline resistance. The in vivo virulence experiment showed that the TNS hvKp strain KP1692 still retained its high virulence compared with KP1677. CONCLUSIONS: hvKp strains accounted for 19.4% among TNS strains. We identified alterations in the ramA upstream region as a mechanism of in vivo tigecycline resistance development in an hvKp strain.


Assuntos
Farmacorresistência Bacteriana , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae , Resistência a Tetraciclina , Tigeciclina , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Proteínas de Bactérias/genética , Humanos , Infecções por Klebsiella/tratamento farmacológico , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , Testes de Sensibilidade Microbiana , Taiwan
6.
Ann Surg Oncol ; 27(Suppl 3): 986, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32779051

RESUMO

In the original version of the article, there was some misalignment of data in Table 1.

7.
Artigo em Inglês | MEDLINE | ID: mdl-29311067

RESUMO

The rate of recovery of carbapenem-resistant Acinetobacter baumannii (CRAB) isolates has increased significantly in recent decades in Taiwan. This study investigated the molecular epidemiology of CRAB with a focus on the mechanisms of resistance and spread in isolates with blaOXA-23-like or blaOXA-24-like All 555 CRAB isolates in our multicenter collection, which were recovered from 2002 to 2010, were tested for the presence of class A, B, and D carbapenemase genes. All isolates with blaOXA-23-like or blaOXA-24-like were subjected to pulsed-field gel electrophoresis, and 82 isolates (60 isolates with blaOXA-23-like and 22 isolates with blaOXA-24-like) were selected for multilocus sequence typing to determine the sequence type (ST) and clonal group (CG) and for detection of additional ß-lactamase and aminoglycoside resistance genes. The flanking regions of carbapenem and aminoglycoside resistance genes were identified by PCR mapping and sequencing. The localization of blaOXA was determined by S1 nuclease and I-CeuI assays. The numbers of CRAB isolates carrying blaOXA-23-like or blaOXA-24-like, especially those carrying blaOXA-23-like, increased significantly from 2008 onward. The blaOXA-23-like gene was carried by antibiotic resistance genomic island 1 (AbGRI1)-type structures located on plasmids and/or the chromosome in isolates of different STs (CG92 and novel CG786), whereas blaOXA-24-like was carried on plasmids in CRAB isolates of limited STs (CG92). No class A or B carbapenemase genes were identified. Multiple aminoglycoside resistance genes coexisted in CRAB. Tn6180-borne armA was found in 74 (90.2%) CRAB isolates, and 58 (70.7%) isolates had Tn6179 upstream, constituting AbGRI3. blaTEM was present in 38 (46.3%) of the CRAB isolates tested, with 35 (92.1%) isolates containing blaTEM in AbGRI2-type structures, and 61% of ampC genes had ISAba1 upstream. We conclude that the dissemination and spread of a few dominant lineages of CRAB containing various resistance island structures occurred in Taiwan.


Assuntos
Acinetobacter baumannii/patogenicidade , Proteínas de Bactérias/metabolismo , beta-Lactamases/metabolismo , Infecções por Acinetobacter/epidemiologia , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/genética , Aminoglicosídeos/farmacologia , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Carbapenêmicos/farmacologia , Humanos , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Taiwan/epidemiologia , beta-Lactamases/genética
8.
J Antimicrob Chemother ; 70(10): 2734-8, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26180132

RESUMO

OBJECTIVES: To investigate the link between two NDM-1-positive Acinetobacter isolates from the same hospital, the plasmid profiles of the isolates were examined. These two isolates were found from a surveillance programme within 3 months from two patients without obvious physical contact or hospitalization time overlap. METHODS: Antimicrobial susceptibility tests, genome sequencing of both isolates and plasmid transfer experiments were performed. A comparative study of similar plasmids was performed using BLAST analysis. RESULTS: The antimicrobial susceptibility of the isolates (Acinetobacter soli M131 and Acinetobacter pittii MS32) and their Escherichia coli transconjugants revealed a conjugative plasmid that carried the carbapenem resistance determinant. Eleven plasmids were observed in M131 and three in MS32. Each isolate shared an identical plasmid that carried the blaNDM-1 gene. This 47 271 bp plasmid harbours a conserved blaNDM-1-containing region that is flanked by ISAba125 and ISAba11 elements, and also contains a Ti-type conjugative operon. The plasmid is nearly identical in sequence to those of Acinetobacter isolates from China. In contrast to the mobilization of the blaNDM-1 sequence in Enterobacteriaceae, which is mainly by transposition, this plasmid moves as a whole among Acinetobacter species. Consistently, this plasmid was found to transfer effectively by in vitro conjugation to several Acinetobacter species. CONCLUSIONS: The clinical and laboratory findings suggest that Acinetobacter species may serve as a reservoir of this blaNDM-1 plasmid. Our study demonstrates the potential of applying genome sequencing to the surveillance of antimicrobial-resistant bacteria.


Assuntos
Infecções por Acinetobacter/microbiologia , Acinetobacter/genética , Conjugação Genética , Transferência Genética Horizontal , Plasmídeos/genética , beta-Lactamases/genética , Acinetobacter/efeitos dos fármacos , Antibacterianos/farmacologia , Infecção Hospitalar , Elementos de DNA Transponíveis , Ordem dos Genes , Genoma Bacteriano , Humanos , Testes de Sensibilidade Microbiana , Resistência beta-Lactâmica
9.
Nucleic Acids Res ; 41(22): 10403-13, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23999094

RESUMO

Filamentous bacteria of the genus Streptomyces possess linear chromosomes and linear plasmids. Theoretically, linear replicons may not need a decatenase for post-replicational separation of daughter molecules. Yet, Streptomyces contain parC and parE that encode the subunits for the decatenase topoisomerase IV. The linear replicons of Streptomyces adopt a circular configuration in vivo through telomere-telomere interaction, which would require decatenation, if the circular configuration persists through replication. We investigated whether topoisomerase IV is required for separation of the linear replicons in Streptomyces. Deletion of parE from the Streptomyces coelicolor chromosome was achieved, when parE was provided on a plasmid. Subsequently, the plasmid was eliminated at high temperature, and ΔparE mutants were obtained. These results indicated that topoisomerase IV was not essential for Streptomyces. Presumably, the telomere-telomere association may be resolved during or after replication to separate the daughter chromosomes. Nevertheless, the mutants exhibited retarded growth, defective sporulation and temperature sensitivity. In the mutants, circular plasmids could not replicate, and spontaneous circularization of the chromosome was not observed, indicating that topoisomerase IV was required for decatenation of circular replicons. Moreover, site-specific integration of a plasmid is impaired in the mutants, suggesting the formation of DNA knots during integration, which must be resolved by topoisomerase IV.


Assuntos
Segregação de Cromossomos , Cromossomos Bacterianos/química , DNA Topoisomerase IV/fisiologia , Streptomyces/genética , DNA Topoisomerase IV/genética , Deleção de Genes , Plasmídeos/biossíntese , Plasmídeos/genética , Streptomyces/crescimento & desenvolvimento
10.
Artigo em Inglês | MEDLINE | ID: mdl-38996869

RESUMO

OBJECTIVES: The prevalence of vancomycin-resistant Enterococcus faecium (VREfm) has increased significantly in Taiwan. We investigated the molecular epidemiology of clinical VREfm isolates to increase our understanding on their spread and changes in population structure over a 14-year span. METHODS: A total of 1113 E. faecium isolates were collected biennially from 2004 to 2018 in Taiwan. MICs were determined by broth microdilution. Whole-genome sequencing (WGS) was performed on 229 VREfm isolates to characterize their genetic environment of vancomycin resistance and wgMLST was used to investigate their clonal relationship. RESULTS: Among the 229 isolates, ST17 and ST78 predominated, especially during the later years, and their prevalences increased from 14.6% (7/48) and 25.0% (12/48) in 2004-2010 to 47.5% (87/181) and 29.8% (54/181) in 2012-2018, respectively. Four types of vanA-carrying Tn1546 variants were detected, with type 1 and type 2 predominated. Type 1 Tn1546 contained an addition of IS1251, while type 2 resembled type 1 but had an addition of IS1678. wgMLST revealed several distinct clusters of ST17 and ST78 isolates, with type 1 Tn1546-harbouring ST17-Cluster 16 being the largest and most widespread clones throughout the study years. Type 2 Tn1546-carrying ST78 became a predominant clone (Cluster 21) after 2012. Isolates within these clusters are highly similar despite being from different hospitals, regions, and study year. CONCLUSION: The increase of VREfm in Taiwan was attributed to horizontal transfer of vanA-carrying Tn1546 variants between different STs and spread of persistent clones. This study highlights the importance of integrating WGS into surveillance to combat antimicrobial resistance.

11.
Antimicrob Agents Chemother ; 57(8): 4072-6, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23752513

RESUMO

Genetic determinants of a bla(NDM-1)-positive, multidrug-resistant bacterial isolate that caused active infection was investigated by DNA sequencing. Two plasmids, pKOX_NDM1 and pKOX-R1, were identified for the Klebsiella oxytoca strain E718. Sequence annotation revealed a bla(NDM-1) gene in pKOX_NDM1 and two extended-spectrum ß-lactamase producers (bla(CTX-M-3) and blaSHV-12) and a wide array of resistance genes in pKOX-R1. These findings highlight the difficulty in treating multidrug-resistant bacterial infections and the potential danger of emerging resistant enterobacteria.


Assuntos
Genes Bacterianos , Klebsiella oxytoca/genética , Plasmídeos/genética , beta-Lactamases/genética , Aminoglicosídeos/farmacologia , Antibacterianos/farmacologia , Conjugação Genética , Escherichia coli/genética , Escherichia coli/metabolismo , Genes MDR , Humanos , Infecções por Klebsiella/diagnóstico , Klebsiella oxytoca/efeitos dos fármacos , Klebsiella oxytoca/enzimologia , Klebsiella oxytoca/isolamento & purificação , Testes de Sensibilidade Microbiana , Taiwan
12.
Protein Sci ; 32(10): e4749, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37555831

RESUMO

Protein oligomerization occurs frequently both in vitro and in vivo, with specific functionalities associated with different oligomeric states. The YqiC protein from Salmonella Typhimurium forms a homotrimer through its C-terminal coiled-coil domain, and the protein is closely linked to the colonization and invasion of the bacteria to the host cells. To elucidate the importance of the oligomeric state of YqiC in vivo and its relation with bacterial infection, we mutated crucial residues in YqiC's coiled-coil region and confirmed the loss of trimer formation using chemical crosslinking and size exclusion chromatography coupled with multiple angle light scattering (SEC-MALS) techniques. The yqiC-knockout strain complemented with mutant YqiC showed significantly reduced colonization and invasion of Salmonella to host cells, demonstrating the critical role of YqiC oligomerization in bacterial pathogenesis. Furthermore, we conducted a protein-protein interaction study of YqiC using a pulled-down assay coupled with mass spectrometry analysis to investigate the protein's role in bacterial virulence. The results reveal that YqiC interacts with subunits of Complex II of the electron transport chain (SdhA and SdhB) and the ß-subunit of F0 F1 -ATP synthase. These interactions suggest that YqiC may modulate the energy production of Salmonella and subsequently affect the assembly of crucial virulence factors, such as flagella. Overall, our findings provide new insights into the molecular mechanisms of YqiC's role in S. Typhimurium pathogenesis and suggest potential therapeutic targets for bacterial infections.


Assuntos
Proteínas , Salmonella typhimurium , Proteínas/metabolismo , Salmonella typhimurium/genética , Salmonella typhimurium/metabolismo , Fatores de Virulência/metabolismo , Proteínas de Bactérias/química
13.
J Microbiol Immunol Infect ; 56(4): 875-879, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37188572

RESUMO

High-level levofloxacin-resistant group A Streptococcus emerged in Taiwan in 2012. Among the 24 isolates identified, 23 belonged to emm12/ST36, most harbored the same GyrA and ParC mutations and were highly clonal. wgMLST showed them to be closely related to the Hong Kong scarlet fever outbreak strains. Continuous surveillance is warranted.


Assuntos
Escarlatina , Infecções Estreptocócicas , Humanos , Levofloxacino/farmacologia , Taiwan/epidemiologia , Streptococcus pyogenes , Escarlatina/tratamento farmacológico , Escarlatina/epidemiologia , Hong Kong , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Infecções Estreptocócicas/epidemiologia , Infecções Estreptocócicas/tratamento farmacológico , Farmacorresistência Bacteriana/genética
14.
Int J Antimicrob Agents ; 62(4): 106944, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37543120

RESUMO

OBJECTIVES: Nontyphoidal Salmonella (NTS) is a major foodborne pathogen causing from acute gastroenteritis to bacteraemia, particularly in paediatric and elderly patients. Antimicrobial resistance of NTS, especially resistance to extended-spectrum cephalosporins, has emerged over the past decades. METHODS: Thirteen NTS isolates resistant to ceftriaxone or cefotaxime were collected from a teaching hospital in Taipei, and another three from a tertiary hospital, in New Taipei City, Taiwan, from September 2018 to December 2019. Ten other archived isolates from 2000 to 2017 were also obtained. Complete genomes of the 26 isolates were obtained. Serovars, sequence types, resistomes, genetic relatedness, and sequence comparison of plasmids were analyzed. RESULTS: Serogroups B, C2 and E were significantly associated with ampicillin resistance. Over 90% of these 26 isolates are susceptible to carbapenems and colistin. Genomic epidemiology of these isolates shows that blaCMY-2-harbouring isolates in different serovars were prevalent over two decades, presumably resulting from highly mobile IncI1 plasmid harbouring blaCMY-2. One type of the IncI1 plasmids contained a mobile element, IS26, which might be involved in the acquisition of antimicrobial resistance genes. Two emerging serovars, S. Goldcoast ST358 harbouring blaCTX-M-55 on IncHI2 plasmids and S. Anatum ST64 harbouring blaDHA-1 on IncA/C2 plasmids persisted in Taiwan, possibly through the clonal spread. Integration of complete or partial plasmid sequences into host chromosomes or multiplications of the antimicrobial resistance genes also appears to be mediated by IS26, in the two emerging clones. CONCLUSION: The dynamic movement of cephalosporinase genes mediated by IS26 in NTS is of great concern.

15.
J Bacteriol ; 194(5): 1256-7, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22328755

RESUMO

We report the complete genome sequence of M013, a representative strain of a pvl-positive, sequence type 59-staphylococcal cassette chromosome mec type V (ST59-SCCmec type V) community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) clone in Taiwan. Comparison of M013 with the genomes of two CA-MRSA strains in the United States revealed major differences in the regions covering several genomic islands and prophages.


Assuntos
DNA Bacteriano/química , DNA Bacteriano/genética , Genoma Bacteriano , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Infecções Estafilocócicas/microbiologia , Toxinas Bacterianas/genética , Infecções Comunitárias Adquiridas/microbiologia , Exotoxinas/genética , Ilhas Genômicas , Leucocidinas/genética , Dados de Sequência Molecular , Tipagem Molecular , Prófagos/genética , Análise de Sequência de DNA , Taiwan , Fatores de Virulência/genética
16.
J Bacteriol ; 194(19): 5454, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22965083

RESUMO

We report the complete genome sequence of Klebsiella oxytoca E718, a New Delhi metallo-ß-lactamase-1 (NDM-1)-producing strain isolated from a renal transplant patient. The genome contains a 6,097,032-bp chromosome and two multidrug resistance plasmids with sizes of 324,906 bp and 110,781 bp.


Assuntos
Infecção Hospitalar/microbiologia , Infecções por Klebsiella/microbiologia , Klebsiella oxytoca/genética , beta-Lactamases/metabolismo , Genoma Bacteriano , Humanos , Transplante de Rim/efeitos adversos , Infecções por Klebsiella/etiologia , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , beta-Lactamases/genética
17.
BMC Genomics ; 13: 679, 2012 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-23194155

RESUMO

BACKGROUND: The increasing number of infections caused by strains of Klebsiella pneumoniae that are resistant to multiple antibiotics has developed into a major medical problem worldwide. The development of next-generation sequencing technologies now permits rapid sequencing of many K. pneumoniae isolates, but sequence information alone does not provide important structural and operational information for its genome. RESULTS: Here we take a systems biology approach to annotate the K. pneumoniae MGH 78578 genome at the structural and operational levels. Through the acquisition and simultaneous analysis of multiple sample-matched -omics data sets from two growth conditions, we detected 2677, 1227, and 1066 binding sites for RNA polymerase, RpoD, and RpoS, respectively, 3660 RNA polymerase-guided transcript segments, and 3585 transcription start sites throughout the genome. Moreover, analysis of the transcription start site data identified 83 probable leaderless mRNAs, while analysis of unannotated transcripts suggested the presence of 119 putative open reading frames, 15 small RNAs, and 185 antisense transcripts that are not currently annotated. CONCLUSIONS: These findings highlight the strengths of systems biology approaches to the refinement of sequence-based annotations, and to provide new insight into fundamental genome-level biology for this important human pathogen.


Assuntos
Regulação Bacteriana da Expressão Gênica , Redes Reguladoras de Genes , Genoma Bacteriano , Klebsiella pneumoniae/genética , Transcrição Gênica , RNA Polimerases Dirigidas por DNA/genética , Anotação de Sequência Molecular , Fases de Leitura Aberta , RNA Antissenso , Pequeno RNA não Traduzido , Análise de Sequência de DNA , Fator sigma/genética , Biologia de Sistemas , Sítio de Iniciação de Transcrição
18.
Chemphyschem ; 13(12): 2937-44, 2012 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-22674527

RESUMO

Anodization of α-Fe(2)O(3) (hematite) electrodes in alkaline electrolyte under constant potential conditions the electrode surface in a way that an additional current wave occurs in the cyclic voltammogram. The energy position of this current wave is closely below the potential of the anodization treatment. Continued cycling or exchanging of the electrolyte causes depletion of this new feature. The O 1s and Fe 2p core-level X-ray photoelectron spectra (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectra of such conditioned hematite exhibit a chemical shift towards higher binding energies, in line with the general perception that anodization generates oxide species with dielectric properties. The valence band XPS and particularly the iron resonant valence band photoemission spectra, however, are shifted towards the opposite direction, that is, towards the Fermi energy, suggesting that hole doping on hematite has taken place during anodization. Quantitative analysis of the Fe 2p resonant valence band photoemission spectra shows that the spectra obtained at the Fe 2p absorption threshold are shifted by virtually the same energy as the anodization potential towards the Fermi energy. The tentative interpretation of this observation is that anodization forms a surface film on the hematite that is specific to the anodization potential.

19.
Antibiotics (Basel) ; 11(5)2022 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-35625324

RESUMO

The overuse of antibiotics has resulted in the emergence of antibiotic resistance, not only in bacteria but also in fungi. Streptomyces are known to produce numerous secondary metabolites including clinically useful antibiotics. In this study, we screened for antibiotic-producing actinobacteria from soils in Taipei and discovered a Streptomyces strain SC26 that displayed antimicrobial activities against Gram-positive bacteria and fungi, but the compounds are heat-labile. Upon UV mutagenesis, a late-sporulation mutant SC263 was isolated with the same antibiotic spectrum but increased in thermostability. The nature of the antibiotic is not clear, but its activity was resistant to proteolytic, nucleolytic and pancreatic digestions, and was retained by the 100 kDa membrane during filtration. To gather more information on SC263, the genome was sequenced, which produced three contigs with a total of 8.2 Mb and was assigned to the species of Streptomyces spororaveus based on the average nucleotide identity to the reference species S. spororaveus NBRC 15456.

20.
Carbohydr Polym ; 281: 119035, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35074103

RESUMO

Chitosan (CS) electrospun nanofiber (ENF) membranes were modified with fucoidan (Fu) and CuS NPs through polyelectrolyte complexation and genipin (GP)-involved cross-linking reaction. The formation of Fu/CS complex and cross-linking of CS with GP increased the acid resistance and reduced the swelling rate of CS ENF, while the covalent conjugation of CuS NPs provided CS ENF with durable Fenton-like catalytic activity. The CuS@ENF composite (ENFC) effectively adsorbed H2O2 and near-infrared (NIR) light, enabling it to kill bacteria by photothermal and photocatalytic bactericidal effects. Fu and copper ions were able to release from the ENFC in a pH-dependent manner, and promoted the alkaline phosphatase activity of osteoblast cells and capillary tube formation of endothelial cells. This study provides a new approach to modify CS ENF with antibacterial and osteoblast differentiation activities, which may be available for bone infection prevention and tissue regeneration.


Assuntos
Quitosana , Nanofibras , Antibacterianos/farmacologia , Quitosana/farmacologia , Cobre , Células Endoteliais , Peróxido de Hidrogênio , Polissacarídeos , Engenharia Tecidual
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