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1.
Int J Mol Sci ; 24(6)2023 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-36982746

RESUMO

Gut dysbiosis can induce chronic inflammation and contribute to atherosclerosis and vascular calcification. The aortic arch calcification (AoAC) score is a simple, noninvasive, and semiquantitative assessment tool to evaluate vascular calcification on chest radiographs. Few studies have discussed the relationship between gut microbiota and AoAC. Therefore, this study aimed to compare the microbiota composition between patients with chronic diseases and high or low AoAC scores. A total of 186 patients (118 males and 68 females) with chronic diseases, including diabetes mellitus (80.6%), hypertension (75.3%), and chronic kidney disease (48.9%), were enrolled. Gut microbiota in fecal samples were analyzed by sequencing of the 16S rRNA gene, and differences in microbial function were examined. The patients were divided into three groups according to AoAC score, including 103 patients in the low AoAC group (AoAC ≤ 3), 40 patients in the medium AoAC group (3 < AoAC ≤ 6), and 43 patients in the high AoAC group (AoAC > 6). Compared to the low AoAC group, the high AoAC group had a significantly lower microbial species diversity (Chao1 index and Shannon index) and increased microbial dysbiosis index. Beta diversity showed that the microbial community composition was significantly different among the three groups (p = 0.041, weighted UniFrac PCoA). A distinct microbial community structure was found in the patients with a low AoAC, with an increased abundance at the genus level of Agathobacter, Eubacterium coprostanoligenes group, Ruminococcaceae UCG-002, Barnesiella, Butyricimonas, Oscillibacter, Ruminococcaceae DTU089, and Oxalobacter. In addition, there was an increased relative abundance of class Bacilli in the high AoAC group. Our findings support the association between gut dysbiosis and the severity of AoAC in patients with chronic diseases.


Assuntos
Microbioma Gastrointestinal , Insuficiência Renal Crônica , Calcificação Vascular , Masculino , Feminino , Humanos , Microbioma Gastrointestinal/genética , Aorta Torácica , Disbiose/microbiologia , RNA Ribossômico 16S/genética
2.
Artigo em Inglês | MEDLINE | ID: mdl-35192451

RESUMO

A novel coagulase-negative Staphylococcus strain (NTUH-S172T) was isolated from human blood culture in Taiwan with preliminary identification of Staphylococcus saprophyticus. 16S rRNA gene analysis and multilocus sequence analysis (MLSA) showed that NTUH-S172T was most closely related to Staphylococcus haemolyticus. The average nucleotide identity and digital DNA-DNA hybridization values with the whole genome sequence were <95 % and<70 % when compared to the related species. Strain NTUH-S172T could be distinguished from S. haemolyticus by urease production and from Staphylococcus borealis by nitrate reduction. In addition, the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) spectrum of NTHU-S172T was significantly different from that of S. haemolyticus, which could be used in clinical identification. In conclusion, it is proposed that this isolate represents a novel species, named Staphylococcus taiwanensis sp. nov., with type strain NTUH-S172T (=BCRC 81315T=JCM 34726T).


Assuntos
Sangue/microbiologia , Ácidos Graxos , Filogenia , Staphylococcus , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Humanos , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Staphylococcus/classificação , Staphylococcus/isolamento & purificação , Taiwan
3.
J Infect Chemother ; 28(11): 1584-1589, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35948247

RESUMO

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) usually causes skin and soft tissue infections (SSTIs), but occasionally causes invasive infections with a broad range of manifestations. Virulence factors and pathogenesis of CA-MRSA have been investigated in details with genotype ST8/SCCmecIVa (USA300), which first emerged in the United States. However, CA-MRSA evolves rapidly, with different clones dominating in different world regions; their pathogenesis remains unclear. CA-MRSA with genotype ST8/SCCmecIVl (CA-MRSA/J) emerged in 2003 in Japan, spreading widely with a fatal case. We have studied the genetic characteristics of CA-MRSA/J, and during the course of this study, we found that CA-MRSA/J has bacteriophage-like spikes with or without a hexagonal cap (spikes X and Xc). Here, we report that CA-MRSA/J strain NN55 has non-phage-like, one-µm-long/jerky spikes with or without a hexagonal cap (LSX/LSXc), and also that LSX/LSXc forms (staphylococcal) interbacterial aggregate/net structures (SIAN). Regarding the phenomenon of SIAN, NN55 first formed single short spike X, followed by multiple molecules of long and jerky LSX/LSXc, leading to the interbacterial construction of SIAN, in colonies with high cell densities. The LSX/LSXc and SIAN structures have not been reported in S. aureus. NN55 was invasive in a HEp-2 cell assay, exhibiting SIAN. The novel SIAN structures may be foci-skeletons or toxic aggregates in NN55's invasive infections. The phenomenon of SIAN suggests novel staphylococcal cell-surface dynamism, providing a new structure-and-function relationship model and advancing the understanding of CA-MRSA pathogenesis.


Assuntos
Infecções Comunitárias Adquiridas , Staphylococcus aureus Resistente à Meticilina , Infecções dos Tecidos Moles , Infecções Estafilocócicas , Infecções Comunitárias Adquiridas/microbiologia , Humanos , Staphylococcus aureus Resistente à Meticilina/genética , Infecções dos Tecidos Moles/microbiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética , Estados Unidos
4.
Int J Mol Sci ; 23(17)2022 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-36077282

RESUMO

Rheumatoid arthritis (RA) and periodontitis are suggested to be closely linked based on microbial dysbiosis, but limited subgingival bacteria have been proven in the pathogenesis of RA. We enrolled 30 RA patients and 25 controls and divided them into three groups with matched age, gender, and diabetes statuses: group AM (all of the matched participants), group PD (periodontally diseased), and group PH (periodontally healthy). Their subgingival microbial composition was determined by V3-V4 16S rRNA gene sequencing. Significant differences in subgingival microbial clustering between the RA patients and controls were observed in groups AM and PD. Among the taxa enriched in RA, Aminipila butyrica and Peptococcus simiae were the only two species displaying positive correlation to the level of anti-citrullinated protein antibodies (ACPAs) in both of the groups. Surprisingly, the median of relative abundances of A. butyrica and P. simiae were 0% in the controls of group PD. Furthermore, a gene encoding arginine deiminase with the capability to produce citrulline was addressed in the complete genome sequence of A. butyrica. This is the first study to elucidate the important roles of A. butyrica and P. simiae as periodontal bacteria leading to RA possibly through the induction of ACPA production.


Assuntos
Artrite Reumatoide , Microbiota , Periodontite , Anticorpos Antiproteína Citrulinada , Autoanticorpos , Bactérias/genética , Humanos , Microbiota/genética , Periodontite/microbiologia , RNA Ribossômico 16S/genética
5.
J Antimicrob Chemother ; 76(7): 1689-1697, 2021 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-33822062

RESUMO

OBJECTIVES: To explore the mechanisms mediating the different levels of gentamicin resistance in enterococci. METHODS: Susceptibility testing with gentamicin and PCR of resistance determinants were performed in 149 enterococcal isolates. Genetic relatedness was characterized by MLST and PFGE analysis. Sequences of the aac(6')-Ie-aph(2'')-Ia gene and its surrounding environment were determined by Illumina sequencing. Stability assays of gentamicin resistance were carried out to evaluate the probability of loss of the high-level gentamicin resistance (HLGR) phenotype. RESULTS: A total of 17 (11.4%) aac(6')-Ie-aph(2'')-Ia-positive enterococcal isolates (2 Enterococcus faecalis and 15 Enterococcus faecium) with non-HLGR phenotype were found. MLST analysis revealed that the 2 E. faecalis belonged to ST116 and ST618, while all the 15 E. faecium belonged to clonal complex 17. Sequence analysis demonstrated that IS1216V was inserted into the 5'-end of aac(6')-Ie-aph(2'')-Ia, leading to loss of HLGR phenotype. Three IS1216V insertion types were found, and type II and III were frequently found in E. faecium. Interestingly, a total of 38 aac(6')-Ie-aph(2'')-Ia-positive E. faecium with HLGR phenotype also had type II or type III IS1216V insertion. Sequencing of the aac(6')-Ie-aph(2'')-Ia-positive HLGR E. faecium E37 revealed that an intact aac(6')-Ie-aph(2'')-Ia was located adjacent to IS1216V-disrupted aac(6')-Ie-aph(2'')-Ia. In a non-antibiotic environment, E37 tended to lose HLGR phenotype with a probability of 1.57 × 10-4, which was largely attributed to homologous recombination between the intact and disrupted aac(6')-Ie-aph(2'')-Ia. CONCLUSIONS: This is first study to elucidate that the E. faecium is capable of changing its HLGR phenotype, which may contribute to adaptation to hospital environments with decreased usage of gentamicin.


Assuntos
Enterococcus faecium , Infecções por Bactérias Gram-Positivas , Aminoglicosídeos , Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Enterococcus , Enterococcus faecalis/genética , Enterococcus faecium/genética , Gentamicinas/farmacologia , Infecções por Bactérias Gram-Positivas/epidemiologia , Humanos , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Taiwan/epidemiologia
6.
Int J Med Sci ; 18(2): 511-519, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33390820

RESUMO

The association between body composition and gut microbiota in type 2 diabetes mellitus (DM) remains unknown. To elucidate the correlation of body composition and gut microbiota, we conducted a clinical study to enroll 179 patients with type 2 DM. Body composition of lean tissue index (LTI) and fat tissue index was measured by Body Composition Monitor. Eight pairs of 16S rRNA gene primers specific to Firmicutes, Bacteroidetes, the Clostridium leptum group, Bacteroides, Bifidobacterium, Akkermansia muciniphila, Escherichia coli, and Faecalibacterium prausnitzii were used to measure their abundance by quantitative polymerase chain reaction. The results showed that type 2 DM with higher abundance of phylum Firmicutes and a higher ratio of phyla Firmicutes to Bacteroidetes (phyla F/B ratio) had higher LTI. This significant correlation between phyla F/B ratio and LTI was especially evident in type 2 DM with high body mass index, and independent of glycemic control or dipeptidyl peptidase-4 inhibitor usage. In conclusion, our study demonstrated the positive association of LTI with the abundance of phylum Firmicutes and the phyla F/B ratio in type 2 DM.


Assuntos
Composição Corporal/imunologia , Diabetes Mellitus Tipo 2/imunologia , Disbiose/complicações , Microbioma Gastrointestinal/imunologia , Idoso , Bacteroidetes/genética , Bacteroidetes/imunologia , Bacteroidetes/isolamento & purificação , DNA Bacteriano/isolamento & purificação , Diabetes Mellitus Tipo 2/microbiologia , Disbiose/diagnóstico , Disbiose/imunologia , Disbiose/microbiologia , Feminino , Firmicutes/genética , Firmicutes/imunologia , Firmicutes/isolamento & purificação , Microbioma Gastrointestinal/genética , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , RNA Ribossômico 16S/genética , Fatores de Risco
7.
J Org Chem ; 84(16): 10172-10182, 2019 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-31298030

RESUMO

We report the formal synthesis of (±)-pentalenolactone A methyl ester from simple 2-methoxyphenol. The key features of our route are as follows: a Diels-Alder reaction of masked o-benzoquinone to assemble the functionalized bicyclo[2.2.2]octenone, a continuous-flow oxa-di-π-methane rearrangement for building the diquinane core (AB ring), and an oxidative cleavage/oxidation sequence for annulation of the δ-lactone (C ring).

8.
Microbiol Immunol ; 61(9): 359-370, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28736993

RESUMO

Streptococcus pneumoniae, a common human pathogen, colonizes the nasopharynx and causes diseases including acute otitis media (AOM). Herein, pneumococcal serotype distributions in children before and after PCV7 vaccination and in patients with pneumococcal disease in Siberian Russia (Krasnoyarsk) are reported. Analyses included antimicrobial susceptibility testing, sequence typing (ST), pulsed field gel electrophoresis, virulence-related surface protein gene (VSG) typing with novel primers and structural analysis by scanning electron microscopy. In healthy children (HC) prior to administration of PCV7, drug-susceptible serotype23F/ST1500 was a major pneumococcal genotype. In the PCV7 trial, multidrug-resistant serotype19A/ST320 emerged in vaccinees after PCV7, exhibiting a PCV7-induced serotype replacement. Multidrug-resistant serotype19A/ST320 was evident in patients with AOM. Community-acquired pneumonia (CAP) isolates showed genetic similarities to the AOM (ST320) genotype, constituting a common non-invasive AOM-CAP group. In contrast, meningitis isolates were more divergent. Overall, 25 ST types were identified; five (20%) of which were Krasnoyarsk-native. Regarding VSGs, PI-1 (rlrA/rrgB), PI-2 (pitA/B), psrP and cbpA were present at 54.3%, 38.6%, 48.6%, and 95.7%, respectively, with two major VSG content types, PI-1- /PI-2- /psrP+ /cbpA+ and PI-1+ /PI-2+ /psrP- /cbpA+ , being found for HC and non-invasive diseases, respectively. A major clone of serotype19A/ST320 (PI-1+ /PI-2+ ) produced the longest pneumococcal wire (pilus) structures in colonies. ST1016 (PI-1- /PI-2- ) in HC had HEp-2 cell-adherent pili. These results suggest that serotype19A/ST320 and related genotypes, with the VSG content type PI-1+ /PI-2+ /psrP- /cbpA+ , emerged in vaccinees after PCV7 in Siberia, accompanying diseases in non-vaccinated children, and that some genotypes (serotypes19A/ST320 and 18/ST1016) produced novel pneumococcal structures, predicting their roles in colony formation and adherence.


Assuntos
Fímbrias Bacterianas/ultraestrutura , Vacina Pneumocócica Conjugada Heptavalente/imunologia , Otite Média/epidemiologia , Infecções Pneumocócicas/epidemiologia , Streptococcus pneumoniae/classificação , Aderência Bacteriana/fisiologia , Linhagem Celular , Pré-Escolar , Humanos , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Tipagem de Sequências Multilocus , Otite Média/microbiologia , Otite Média/prevenção & controle , Infecções Pneumocócicas/microbiologia , Infecções Pneumocócicas/prevenção & controle , Federação Russa/epidemiologia , Sibéria/epidemiologia , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/imunologia , Vacinação , Fatores de Virulência/genética
9.
Antimicrob Agents Chemother ; 60(8): 5006-9, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27161629

RESUMO

We analyzed the staphylococcal cassette chromosome mec (SCCmec) types of 143 fusidic acid- and methicillin-resistant Staphylococcus epidermidis isolates. The most frequent SCCmec type was SCCmec III/SCCHg (53%), followed by SCCmec IV (29%). Clonal spreading of SCCmec III/SCCHg strains contributed to the increased prevalence of SCCmec III. A novel non-mec SCC structure, SCC7684, adjacent to SCCmec III, which carries a new ccrC allotype (ccrC3 allele 1) and contains heavy metal resistance genes, was identified in 14 isolates.


Assuntos
Cromossomos Bacterianos/genética , Ácido Fusídico/farmacologia , Staphylococcus epidermidis/efeitos dos fármacos , Staphylococcus epidermidis/genética , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Resistência a Meticilina/genética , Testes de Sensibilidade Microbiana
10.
Antimicrob Agents Chemother ; 60(10): 6108-14, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27480862

RESUMO

We determined the resistance determinants in 274 erythromycin-resistant methicillin-susceptible Staphylococcus aureus (MSSA) isolates during a 13-year period, 2000 to 2012. The resistance phenotypes, inducible macrolide-lincosamide-streptogramin (iMLS), constitutive MLS (cMLS), and macrolide-streptogramin (MS) resistance phenotypes, were examined by a double-disk diffusion D test. The ermB gene was more frequent (35%; 97/274) than ermC (27%; 75/274) or ermA (21%; 58/274). All 97 ermB-positive isolates harbored Tn551 and IS1216V The majority (89/97) of ermB-positive isolates displayed the cMLS phenotype and carried mobile element structure (MES)-like structures, which has been previously reported in sequence type 59 (ST59) methicillin-resistant S. aureus (MRSA). The remaining 8 ermB-carrying isolates, belonging to ST7 (n = 4), ST5 (n = 3), and ST59 (n = 1), were sasK intact and did not carry MES-like structures. Unlike a MES-like structure that was located on the chromosome, the ermB elements on sasK-intact isolates were located on plasmids by S1 nuclease pulsed-field gel electrophoresis (PFGE) analysis and conjugation tests. Sequence data for the ermB-containing region (14,566 bp) from ST59 NTUH_3874 revealed that the best match was a Tn1546-like element in plasmid pMCCL2 DNA (GenBank accession number AP009486) of Macrococcus caseolyticus Tn1546 is recognized as an enterococcal transposon and was known from the vancomycin resistance gene cluster in vancomycin-resistant Enterococcus (VRE). So far, acquisitions of Tn1546 in S. aureus have occurred in clonal complex 5 (CC5) MRSA, but not in MSSA. This is the first report that MSSA harbors an Enterococcus faecium-originated ermB-positive Tn1546-like element located on a plasmid.


Assuntos
Elementos de DNA Transponíveis , Farmacorresistência Bacteriana Múltipla/genética , Enterococcus faecium/genética , Transferência Genética Horizontal , Staphylococcus aureus Resistente à Meticilina/genética , Plasmídeos/metabolismo , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Cromossomos Bacterianos/química , Conjugação Genética , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Eletroforese em Gel de Campo Pulsado , Enterococcus faecium/efeitos dos fármacos , Enterococcus faecium/metabolismo , Enterococcus faecium/patogenicidade , Expressão Gênica , Isoenzimas/genética , Isoenzimas/metabolismo , Lincosamidas/farmacologia , Macrolídeos/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/metabolismo , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Metiltransferases/genética , Metiltransferases/metabolismo , Fenótipo , Plasmídeos/química , Análise de Sequência de DNA , Estreptograminas/farmacologia
11.
J Antimicrob Chemother ; 71(7): 1807-14, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26968883

RESUMO

OBJECTIVES: Small colony variants (SCVs) of Staphylococcus aureus are associated with persistent and drug-resistant infections. We demonstrated for the first time the emergence of SCVs in a patient with vancomycin-intermediate S. aureus (VISA) infection during long-term treatment with daptomycin. METHODS: A 73-year-old man with septic arthritis was infected with VISA. The patient was treated with daptomycin; however, the patient remained infected with VISA, with continuous isolation of VISA from his blood during long-term treatment. Five VISA isolates were characterized by: PFGE; genotyping including staphylococcal cassette chromosome mec (SCCmec), spa and MLST; antimicrobial susceptibility testing; and scanning and transmission electron microscopy. WGS and fatty acid analysis were also performed. RESULTS: The five VISA isolates were from a single clone of ST239/spa3(t037) and, of these, the first three were SCCmecIII positive and daptomycin susceptible, whereas the last two were SCCmecIII negative and daptomycin resistant and exhibited the characteristics of SCVs. The first and last isolates showed 13 remarkable genetic differences in SCCmec and the mprF, cls2, clpX and fabF genes. Of these, mutation of fabF (encoding the fatty acid synthase) seemed to be partially responsible for the slow growth and ultrastructural features, including an abnormal intercellular substance, and for the daptomycin resistance of SCVs. CONCLUSIONS: For the first time, we identified SCVs of VISA in a patient with septic arthritis during long-term treatment with daptomycin. Daptomycin-resistant SCVs of VISA were evolved in a stepwise manner and the mutation of fabF is likely responsible for the physical and ultrastructural characteristics and daptomycin resistance.


Assuntos
Antibacterianos/uso terapêutico , Artrite Infecciosa/microbiologia , Daptomicina/uso terapêutico , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Resistência a Vancomicina , Vancomicina/farmacologia , Idoso , Antibacterianos/farmacologia , Artrite Infecciosa/tratamento farmacológico , Farmacorresistência Bacteriana , Genótipo , Humanos , Masculino , Testes de Sensibilidade Microbiana , Microscopia Eletrônica , Tipagem de Sequências Multilocus , Fenótipo , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/ultraestrutura , Tempo
12.
Mar Drugs ; 14(8)2016 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-27483290

RESUMO

Nosocomial infections and increasing multi-drug resistance caused by Acinetobacter baumannii have been recognized as emerging problems worldwide. Moreover, A. baumannii is able to colonize various abiotic materials and medical devices, making it difficult to eradicate and leading to ventilator-associated pneumonia, and bacteremia. Development of novel molecules that inhibit bacterial biofilm formation may be an alternative prophylactic option for the treatment of biofilm-associated A. baumannii infections. Marine environments, which are unlike their terrestrial counterparts, harbor an abundant biodiversity of marine organisms that produce novel bioactive natural products with pharmaceutical potential. In this study, we identified 5-episinuleptolide, which was isolated from Sinularia leptoclados, as an inhibitor of biofilm formation in ATCC 19606 and three multi-drug resistant A. baumannii strains. In addition, the anti-biofilm activities of 5-episinuleptolide were observed for Gram-negative bacteria but not for Gram-positive bacteria, indicating that the inhibition mechanism of 5-episinuleptolide is effective against only Gram-negative bacteria. The mechanism of biofilm inhibition was demonstrated to correlate to decreased gene expression from the pgaABCD locus, which encodes the extracellular polysaccharide poly-ß-(1,6)-N-acetylglucosamine (PNAG). Scanning electron microscopy (SEM) indicated that extracellular matrix of the biofilm was dramatically decreased by treatment with 5-episinuleptolide. Our study showed potentially synergistic activity of combination therapy with 5-episinuleptolide and levofloxacin against biofilm formation and biofilm cells. These data indicate that inhibition of biofilm formation via 5-episinuleptolide may represent another prophylactic option for solving the persistent problem of biofilm-associated A. baumannii infections.


Assuntos
Infecções por Acinetobacter/prevenção & controle , Acinetobacter baumannii/efeitos dos fármacos , Antozoários/química , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Infecção Hospitalar/prevenção & controle , Diterpenos/farmacologia , Farmacorresistência Bacteriana Múltipla , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/fisiologia , Acinetobacter baumannii/ultraestrutura , Animais , Antibacterianos/química , Antibacterianos/isolamento & purificação , Produtos Biológicos/isolamento & purificação , Produtos Biológicos/farmacologia , Infecção Hospitalar/microbiologia , Diterpenos/química , Diterpenos/isolamento & purificação , Sinergismo Farmacológico , Contaminação de Equipamentos , Matriz Extracelular/efeitos dos fármacos , Matriz Extracelular/ultraestrutura , Genes Bacterianos/efeitos dos fármacos , Humanos , Levofloxacino/farmacologia , Microscopia Eletrônica de Varredura , beta-Glucanas/metabolismo
13.
J Antimicrob Chemother ; 70(2): 416-9, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25313205

RESUMO

OBJECTIVES: To determine MICs of fusidic acid for and identify genetic determinants of resistance in Staphylococcus cohnii isolates. METHODS: Susceptibility to fusidic acid was determined by the standard agar dilution method in 24 S. cohnii subsp. urealyticus clinical isolates, 7 S. cohnii subsp. cohnii clinical isolates and 2 reference strains. Sequencing of a novel resistance determinant, fusF, and its flanking regions was performed by long and accurate PCR and inverse PCR. To evaluate the function of fusF, the MIC of fusidic acid was determined for recombinant Staphylococcus aureus carrying a plasmid expressing fusF. RESULTS: A total of 25 S. cohnii subsp. urealyticus (24 clinical isolates and 1 reference strain) and 2 S. cohnii subsp. cohnii displayed low-level resistance to fusidic acid (MICs 2-16 mg/L). Sequencing of a 4259 bp fragment from S. cohnii subsp. urealyticus ATCC 49330 revealed a novel resistance gene, designated fusF, which displayed 70.5% nucleotide and 67.3% amino acid identity to fusD. Expression of fusF in S. aureus confers resistance to fusidic acid. CONCLUSIONS: A novel FusB-family gene, fusF, was identified as a major resistance determinant in S. cohnii clinical isolates resistant to fusidic acid.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Ácido Fusídico/farmacologia , Genes Bacterianos , Staphylococcus/efeitos dos fármacos , Staphylococcus/genética , Farmacorresistência Bacteriana/genética , Ordem dos Genes , Humanos , Testes de Sensibilidade Microbiana , Fases de Leitura Aberta , Análise de Sequência de DNA , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética
14.
Kansenshogaku Zasshi ; Suppl 13: 15-27, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26529983

RESUMO

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) has become a major concern worldwide. In the United States, ST8 CA-MRSA with SCCmecIVa (USA300) has been predominant, affecting the entire United States. In this study, we investigated Japanese ST8 CA-MRSA with new SCCmecIV1 (designated ST8 CA-MRSA/J), which has emerged in Japan since 2003. Regarding community spread and infections, ST8 CA-MRSA/J spread in 16.2-34.4% as a major genotype in the community in Japan, and was associated with skin and soft tissue infections (SSTIs), colitis, and invasive infections (sepsis, epidural abscesses, and necrotizing pneumonia), including influenza prodrome cases and athlete infections, similar to USA300. It spread to even public transport and Hong Kong through a Japanese family. Regarding genetic diversity, ST8 CA-MRSA/J included ST and spa variants and was classified into at least three pulsed-field gel electrophoresis types, ST8 Jα to γ. Of those, ST8 Jß was associated with severe invasive infections. As for genomics, ST8 CA-MRSA/J showed high similarities to USA300, but with marked diversity in accessory genes; e.g., ST8 CA-MRSA/J possessed enhanced cytolytic peptide genes of CA-MRSA, but lacked the Panton-Valentine leukocidin phage and arginine catabolic mobile element, unlike USA300. The unique features of ST8 CA-MRSA/J included a novel mosaic SaPI (designated SaPIj50) carrying the toxic shock syndrome toxin-1 gene with high expression; the evolution included salvage (through recombination) of hospital-acquired MRSA virulence. The data suggest that ST8 CA-MRSA/J has become a successful native clone in Japan, in association with not only SSTIs but also severe invasive infections (posing a threat), requiring attention.


Assuntos
Genoma Bacteriano , Staphylococcus aureus Resistente à Meticilina/genética , Infecções Estafilocócicas , Regulação Bacteriana da Expressão Gênica , Genômica , Genótipo , Humanos , Japão , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Filogenia , RNA Mensageiro/genética , Virulência
15.
Antimicrob Agents Chemother ; 58(2): 1224-7, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24277045

RESUMO

A high prevalence of fusC (16/46, 59%) was found in fusidic acid-resistant methicillin-resistant Staphylococcus aureus isolates collected from 2008 to 2010. Nucleotide sequencing of fusC and flanking regions revealed a novel staphylococcal cassette chromosome (SCC) structure, SCCfusC, which was integrated into rlmH and located upstream from SCCmec. The SCCfusC element contained speG, which may contribute to the polyamine resistance.


Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Cromossomos Bacterianos , Farmacorresistência Bacteriana Múltipla/genética , Ácido Fusídico/farmacologia , Staphylococcus aureus Resistente à Meticilina/genética , Proteínas de Bactérias/metabolismo , Sequência de Bases , Eletroforese em Gel de Campo Pulsado , Expressão Gênica , Humanos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Staphylococcus aureus Resistente à Meticilina/metabolismo , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Mutação , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia
16.
Int J Syst Evol Microbiol ; 64(Pt 6): 2060-2065, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24664577

RESUMO

Four Gram-staining-positive, catalase-negative, coccoid isolates, designated NTUH_1465(T), NTUH_2196, NTUH_4957 and NTUH_5572(T), were isolated from human specimens. The four isolates displayed more than 99.6% 16S rRNA gene sequence similarity with Gemella haemolysans ATCC 10379(T), and 96.7 to 98.6% similarity with Gemella sanguinis ATCC 700632(T), Gemella morbillorum ATCC 27824(T) or Gemella cuniculi CCUG 42726(T). However, phylogenetic analysis of concatenated sequences of three housekeeping genes, groEL, rpoB and recA, suggested that the four isolates were distinct from G. haemolysans ATCC 10379(T) and other species. Isolates NTUH_2196, NTUH_4957 and NTUH_5572(T) clustered together and formed a stable monophyletic clade. DNA-DNA hybridization values among strains NTUH_1465(T) and NTUH_5572(T) and their phylogenetically related neighbours were all lower than 49%. The four isolates could be distinguished from G. haemolysans and other species by phenotypic characteristics. Based on the phylogenetic and phenotypic results, two novel species Gemella parahaemolysans sp. nov. (type strain NTUH_1465(T) = BCRC 80365(T) = JCM 18067(T)) and Gemella taiwanensis sp. nov. (type strain NTUH_5572(T) = BCRC 80366(T) = JCM 18066(T)) are proposed.


Assuntos
Gemella/classificação , Filogenia , Idoso , Idoso de 80 Anos ou mais , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Feminino , Gemella/genética , Gemella/isolamento & purificação , Genes Bacterianos , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Tipagem de Sequências Multilocus , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Taiwan
17.
Biomed Opt Express ; 15(8): 4909-4924, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39346983

RESUMO

This study utilizes a Mueller matrix-based system to extract accurate glucose levels from human fingertips, addressing challenges in skin complexity. Integration of domain knowledge and data science aims to enhance prediction accuracy using a Random Forest model. The primary goal is to improve glucose level predictions by selecting effective features based on the Pearson product-moment correlation coefficient (PPMCC). The interpolation compensates for delayed glucose concentration. This study integrates domain knowledge and data science, combining a Mueller matrix-based system and a random forest model. It is noted that 16 effective features were identified from 27 test points collected from a healthy volunteer in the laboratory. These features were divided into training and prediction sets in a ratio of 8:2. As a result, the regression coefficient, R2, was 0.8907 and the mean absolute relative difference (MARD) was 6.8%, respectively. This significantly improves prediction accuracy, demonstrating the model's robustness and reliability in accurately forecasting outcomes based on the identified features. In addition, in the Institutional Review Board (IRB) tests at NCKU's hospital, all data passed the same preprocessing and model. The measurement results from an individual diabetic patient demonstrate high accuracy for blood glucose concentrations below 150 mg/dL, with acceptable deviation at higher levels and no severe error zones. Over a three-month period, data from the participating diabetic patient showed a MARD of 4.44% with the R2 of 0.836, and the other patient recorded a MARD of 7.79% with the R2 of 0.855. The study shows the proposed approach accurately extracts glucose levels. Integrating domain knowledge, data science, and effective strategies significantly improves prediction accuracy.

18.
Artigo em Inglês | MEDLINE | ID: mdl-39232888

RESUMO

BACKGROUND: Vancomycin-variable enterococci (VVE) are vanA-carrying Enterococcus faecium that are phenotypically susceptible to vancomycin and can only be detected using molecular methods, leading to the possibility of treatment failure and posing threats to infection control. This study aimed to determine the prevalence of VVE and its associated clinical risk factors. METHODS: This retrospective study was conducted in two hospitals in southern Taiwan. Patients with phenotypically vancomycin-susceptible E. faecium bacteremia were enrolled between 2017 and 2021. VVEs were defined as isolates harboring the vanA gene that were phenotypically susceptible to vancomycin. Vancomycin-susceptible E. faecium (VSE) isolates were phenotypically susceptible to vancomycin and lacked vanA or vanB genes. RESULTS: Of the 142 enrolled patients, 121 (85.2%) had VSE and 21 (14.8%) had VVE. Resistance rates to penicillin, tetracycline, and fosfomycin were higher in VVE isolates. Malignancy (adjusted odds ratio [aOR] = 4.87; 95% confidence interval [CI] 1.54-15.41, p = 0.007) and central venous catheter usage (aOR = 4.69; 95% CI 1.49-14.78, p = 0.008) were the independent risk factors associated with VVE bacteremia. Being male (aOR = 0.12, CI 0.03-0.44, p = 0.002) was less likely to be associated with VVE bacteremia. Although VVE was not associated with 30-day mortality (38.1% [VVE] vs. 35.5% [VSE], p = 0.822), one case of subsequent vancomycin-resistant enterococci infection in the VVE group with vancomycin treatment (4.8%, 1/21) was identified, which led to subsequent mortality. CONCLUSIONS: The prevalence of VVE was high among E. faecium isolates with vancomycin-susceptible phenotypes in southern Taiwan. Although the current study revealed that VVE bacteremia was not associated with poor clinical outcome, further multicenter surveillance survey is recommended to evaluate the possible impact of VVE on public health in Taiwan.

19.
J Clin Endocrinol Metab ; 109(8): 2097-2105, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38267025

RESUMO

CONTEXT: Type 2 diabetes (T2D) is the major contributor to chronic kidney disease and end-stage kidney disease (ESKD). The influence of trimethylamine N-oxide (TMAO) on kidney outcomes in T2D remains unclear. OBJECTIVE: To examine the association between fasting serum TMAO levels and adverse kidney outcomes in patients with T2D. METHODS: Between October 2016 and June 2020, patients with T2D were recruited and monitored every 3 months until December 2021. Serum TMAO levels were assessed using liquid chromatography-mass spectrometry. The primary kidney outcomes were doubling of serum creatinine levels or progression to ESKD necessitating dialysis; the secondary kidney outcome was a rapid 30% decline in estimated glomerular filtration rate within 2 years. All-cause mortality was also evaluated. RESULTS: Among the 440 enrolled patients with T2D, those in the highest serum TMAO tertile (≥0.88 µM) were older, had a longer diabetes duration, elevated blood urea nitrogen, and lower estimated glomerular filtration rate. Over a median follow-up period of 4 years, 26 patients (5.9%) had a doubling of serum creatinine level or progression to ESKD. After propensity score weighting, the patients in the highest serum TMAO tertile had a 6.45-fold increase in the risk of doubling of serum creatinine levels or progression to ESKD and 5.86-fold elevated risk of rapid decline in kidney function compared with those in the lowest tertile. Additionally, the stepwise increase in serum TMAO was associated with all-cause mortality. CONCLUSION: Patients with T2D with elevated circulating TMAO levels are at higher risk of doubling serum creatinine, progressing to ESKD, and mortality. TMAO is a potential biomarker for kidney function progression and mortality in patients with T2D.


Assuntos
Diabetes Mellitus Tipo 2 , Nefropatias Diabéticas , Progressão da Doença , Taxa de Filtração Glomerular , Falência Renal Crônica , Metilaminas , Humanos , Metilaminas/sangue , Diabetes Mellitus Tipo 2/mortalidade , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/complicações , Feminino , Masculino , Pessoa de Meia-Idade , Idoso , Nefropatias Diabéticas/mortalidade , Nefropatias Diabéticas/sangue , Falência Renal Crônica/mortalidade , Falência Renal Crônica/sangue , Biomarcadores/sangue , Creatinina/sangue , Insuficiência Renal Crônica/mortalidade , Insuficiência Renal Crônica/sangue , Seguimentos , Prognóstico , Rim/fisiopatologia
20.
Antibiotics (Basel) ; 13(9)2024 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-39335079

RESUMO

Recently, the high proportion of methicillin-resistant Staphylococcus aureus infections worldwide has highlighted the urgent need for novel antibiotics to combat this crisis. The recent progress in computational techniques for use in health and medicine, especially artificial intelligence (AI), has created new and potential approaches to combat antibiotic-resistant bacteria, such as repurposing existing drugs, optimizing current agents, and designing novel compounds. Halicin was previously used as a diabetic medication, acting as a c-Jun N-terminal protein kinase (JNK) inhibitor, and has recently demonstrated unexpected antibacterial activity. Although previous efforts have highlighted halicin's potential as a promising antibiotic, evidence regarding its effectiveness against clinical strains remains limited, with insufficient proof of its clinical applicability. In this study, we sought to investigate the antibacterial activity of halicin against MRSA clinical strains to validate its clinical applicability, and a C. elegans model infected by MRSA was employed to evaluate the in vivo effect of halicin against MRSA. Our findings revealed the antibacterial activity of halicin against methicillin-resistant S. aureus clinical strains with MICs ranging from 2 to 4 µg/mL. Our study is also the first work to evaluate the in vivo effect of halicin against S. aureus using a C. elegans model, supporting its further development as an antibiotic.

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