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1.
Nano Lett ; 22(12): 4694-4701, 2022 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-35674669

RESUMO

Semiconductor nanocrystals are promising candidates for generating chemical feedstocks through photocatalysis. Understanding the role of ligands used to prepare colloidal nanocrystals in catalysis is challenging due to the complexity and heterogeneity of nanocrystal surfaces. We use in situ single-molecule fluorescence imaging to map the spatial distribution of active regions along individual tungsten oxide nanowires before and after functionalizing them with ascorbic acid. Rather than blocking active sites, we observed a significant enhancement in activity for photocatalytic water oxidation after treatment with ascorbic acid. While the initial nanowires contain inactive regions dispersed along their length, the functionalized nanowires show high uniformity in their photocatalytic activity. Spatial colocalization of the active regions with their surface chemical properties shows that oxidation of ascorbic acid during photocatalysis generates new oxygen vacancies along the nanowire surface. We demonstrate that controlling surface-ligand redox chemistry during photocatalysis can enhance the active site concentration on nanocrystal catalysts.


Assuntos
Nanofios , Ácido Ascórbico , Catálise , Ligantes , Nanofios/química , Oxirredução , Óxidos , Tungstênio
2.
J Am Chem Soc ; 143(30): 11393-11403, 2021 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-34284584

RESUMO

The surface structure of semiconductor photocatalysts controls the efficiency of charge-carrier extraction during photocatalytic reactions. However, understanding the connection between surface heterogeneity and the locations where photogenerated charge carriers are preferentially extracted is challenging. Herein we use single-molecule fluorescence imaging to map the spatial distribution of active regions and quantify the activity for both photocatalytic oxidation and reduction reactions on individual bismuth oxybromide (BiOBr) nanoplates. Through a coordinate-based colocalization analysis, we quantify the spatial correlation between the locations where fluorogenic probe molecules are oxidized and reduced on the surface of individual nanoplates. Surprisingly, we observed two distinct photochemical behaviors for BiOBr particles prepared within the same batch, which exhibit either predominantly uncorrelated activity where electrons and holes are extracted from different sites or colocalized activity in which oxidation and reduction take place within the same nanoscale regions. By analyzing the emissive properties of the fluorogenic probes, we propose that electrons and holes colocalize at defect-deficient regions, while defects promote the selective extraction of one carrier type by trapping either electrons or holes. Although previous work has used defect engineering to enhance the activity of bismuth oxyhalides and other semiconductor photocatalysts for useful reductive half-reactions (e.g., CO2 or N2 reduction), our results show that defect-free regions are needed to promote both oxidation and reduction in fuel-generating photocatalysts that do not rely on sacrificial reagents.

3.
J Formos Med Assoc ; 116(9): 660-670, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28647219

RESUMO

BACKGROUND/PURPOSE: Aspergillus-associated infection might comprise up to 23-29% of severe influenza patients from the community throughout stay in an intensive care unit (ICU). In Taiwan, cases of severe influenza with aspergillosis are increasingly reported. Therefore, we describe the relative risk of mortality among severe influenza patients with aspergillosis and other coinfections compared to severe influenza patients without Aspergillus coinfections. METHODS: We retrospectively reviewed 124 adult patients with severe influenza in a tertiary medical center in southern Taiwan from January 2015 through March 2016. The definition of probable aspergillosis required abnormal radiological findings and positive Aspergillus galactomannan (GM) antigen and/or Aspergillus isolation. RESULTS: Probable aspergillosis (detected throughout the whole course) and other coinfections (only community-acquired) were diagnosed in 21 (17%) and 38 (31%) of all patients respectively. Klebsiella pneumoniae (36.8%), Pseudomonas aeruginosa (31.6%) and Staphylococcus aureus (31.6%) were the most frequent isolates of other coinfections. In-ICU mortality of Aspergillus group (66.7%) was significantly higher than other coinfections (23.7%, p = 0.001) or control group without coinfections (15.4%, p < 0.001), with significant odds ratios after adjusting for important variables. The factor of GM index ≥0.6 had a 19.82 (95% CI, 4.91 to 80.07, p < 0.0001) odds of expiring in an ICU among the Aspergillus group. CONCLUSION: Dual Aspergillus and influenza infection is emerging in southern Taiwan. Meanwhile, community-acquired P. aeruginosa should be listed in the common copathogens with severe influenza. The 67% mortality linked to aspergillosis highlights the need for physicians to focus attention on patients with GM ≥ 0.6.


Assuntos
Aspergilose/mortalidade , Coinfecção/mortalidade , Influenza Humana/mortalidade , Idoso , Aspergilose/diagnóstico por imagem , Coinfecção/diagnóstico por imagem , Feminino , Mortalidade Hospitalar , Humanos , Influenza Humana/diagnóstico por imagem , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco
5.
Telemed J E Health ; 21(4): 274-80, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25615278

RESUMO

ST elevation myocardial infarction (STEMI), one main type of acute myocardial infarction with high mortality, requires percutaneous coronary intervention (PCI) with balloon inflation. Current guidelines recommend a door-to-balloon (D2B) interval (i.e., starts with the patient's arrival in the emergency department and ends when PCI with a catheter guidewire and balloon inflation crosses the culprit lesion) of no more than 90 min. However, promptly implementing PCI requires coordinating various medical teams. Checklists can be used to ensure consistency and operating sequences when executing complex tasks in a clinical routine. Developing an effective D2B checklist would enhance the care of STEMI patients who need PCI. Mobile information and communication technologies have the potential to greatly improve communication, facilitate access to information, and eliminate duplicated documentation without the limitations of space and time. In a research project by the Chi Mei Medical Center, "Developing a Mobile Electronic D2B Checklist for Managing the Treatment of STEMI Patients Who Need Primary Coronary Intervention," a prototype version of a mobile checklist was developed. This study describes the research project and the four phases of the system development life cycle, comprising system planning and selection, analysis, design, and implementation and operation. Face-to-face interviews with 16 potential users were conducted and revealed highly positive user perception and use intention toward the prototype. Discussion and directions for future research are also presented.


Assuntos
Lista de Checagem/métodos , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/terapia , Telecomunicações/organização & administração , Tempo para o Tratamento , Idoso , Angioplastia Coronária com Balão/métodos , Angioplastia Coronária com Balão/mortalidade , Lista de Checagem/instrumentação , Eletrocardiografia/métodos , Serviços Médicos de Emergência/organização & administração , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/mortalidade , Prognóstico , Desenvolvimento de Programas , Medição de Risco , Taxa de Sobrevida , Taiwan , Resultado do Tratamento
6.
Appl Microbiol Biotechnol ; 98(18): 7911-22, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25060680

RESUMO

Validamycin A (VAL-A) is a widely used antifungal antibiotic for the treatment of sheath blight disease of rice and other plants. It can be produced from agro-industrial by-products by Streptomyces hygroscopicus 5008. To enhance its production titer, in this work, the entire val gene cluster was amplified in tandem in S. hygroscopicus 5008 by integrating the zouA-mediated DNA amplification system into between the two boundaries of val gene cluster, resulting in multiple copies (mainly three to five) of the val gene cluster. The genetic stability of the amplified copies was confirmed by Southern blot and fermentation experiments. In shake flask fermentation, the recombinant strain (TC03) led to a 34% enhancement of VAL-A production titer compared to that of the wild-type strain, while the accumulation of intermediate validoxylamine A was decreased in TC03. Additionally, both the structural gene transcription levels and the ValG enzyme activity were significantly increased in TC03. This work demonstrated that the amplification of the val gene cluster was an efficient strategy to enhance VAL-A production by S. hygroscopicus 5008, and the information obtained would be helpful for engineering other interesting antibiotic biosynthesis by gene cluster amplification.


Assuntos
Inositol/análogos & derivados , Família Multigênica/genética , Streptomyces/metabolismo , Inositol/genética , Inositol/metabolismo , Família Multigênica/fisiologia , Streptomyces/genética
7.
J Antimicrob Chemother ; 68(8): 1910-6, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23580558

RESUMO

OBJECTIVES: To investigate the impact of the directly observed therapy, short course (DOTS) and DOTS-Plus strategies on changes in resistance profiles among Mycobacterium tuberculosis (MTB). METHODS: We performed a retrospective analysis of resistance profiles among isolates of MTB obtained from 2160 consecutive patients with culture-confirmed pulmonary tuberculosis (TB) between 2005 and 2011 at a referral centre in southern Taiwan. RESULTS: Of the 2160 patients, 70 (3.2%) had primary multidrug-resistant (MDR)-TB, 178 (8.2%) had acquired MDR-TB, 10 (0.5%) had primary extensively drug-resistant (XDR)-TB, 23 (1.1%) had acquired XDR-TB and 5 (0.2%) had totally drug-resistant (TDR)-TB. Trend analysis revealed that the rates of acquired MDR-TB were significantly lower after implementation of the DOTS and DOTS-Plus programmes (P < 0.01). There was a significant negative correlation between the coverage rates of the DOTS and DOTS-Plus programmes and the rates of acquired MDR-TB (r = -0.84, P = 0.02 and r = -0.92, P = 0.03, respectively). The rates of resistance to rifampicin, isoniazid, ofloxacin, moxifloxacin, levofloxacin and para-aminosalicylic acid also decreased significantly during the study period. However, the rates of primary MDR-TB remained stable (P = 0.11). Multivariate logistic regression analysis showed that age ranging from 45 to 64 years, positive acid-fast stain results at the initiation of treatment and treatment without DOTS were independent risk factors associated with acquired MDR-TB. In addition, previous treatment for TB (100% versus 19% for TDR-TB and non-TDR-TB, P < 0.01) and treatment without DOTS (80% versus 44% for TDR-TB and non-TDR-TB, P = 0.18) were risk factors for TDR-TB. CONCLUSIONS: DOTS and DOTS-Plus are both effective at preventing the acquisition of MDR-TB in Taiwan.


Assuntos
Antituberculosos/administração & dosagem , Terapia Diretamente Observada/métodos , Transmissão de Doença Infecciosa/prevenção & controle , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/isolamento & purificação , Prevalência , Estudos Retrospectivos , Taiwan/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/prevenção & controle , Tuberculose Resistente a Múltiplos Medicamentos/transmissão , Adulto Jovem
8.
J Clin Microbiol ; 50(9): 2982-6, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22760035

RESUMO

This study investigated the clinical and microbiological characteristics of patients with recurrent bacteremia caused by the Acinetobacter calcoaceticus-Acinetobacter baumannii (ACB) complex at a medical center. All ACB complex isolates associated with recurrent bacteremia were identified to the genomic species level using a 16S-23S rRNA gene intergenic spacer sequence-based method. Genotypes were determined by the random amplified polymorphic DNA patterns generated by arbitrarily primed PCR and by pulsotypes generated by pulsed-field gel electrophoresis. Relapse of infection was defined as when the genotype of the recurrent isolate was identical to that of the original infecting strain. Reinfection was defined as when the genospecies or genotype of the recurrent isolate differed from that of the original isolate. From 2006 to 2008, 446 patients had ACB complex bacteremia and 25 (5.6%) had recurrent bacteremia caused by the ACB complex. Among the 25 patients, 12 (48%) had relapse of bacteremia caused by A. nosocomialis (n = 7) or A. baumannii (n = 5). Among the 13 patients with reinfection, 5 (38.5%) had reinfection caused by different genospecies of the ACB complex. Most of the patients were immunocompromised, and most of the infection foci were catheter-related bloodstream infections. The overall in-hospital mortality rate was 33.3%. A. baumannii isolates had lower antimicrobial susceptibility rates than A. nosocomialis and A. pittii isolates. In conclusion, relapse of ACB complex bacteremia can develop in immunocompromised patients, especially those with central venous catheters. Molecular methods to identify the ACB complex to the genospecies level are essential for differentiating between reinfection and relapse of bacteremia caused by the ACB complex.


Assuntos
Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/isolamento & purificação , Acinetobacter calcoaceticus/isolamento & purificação , Bacteriemia/microbiologia , Centros Médicos Acadêmicos , Infecções por Acinetobacter/epidemiologia , Infecções por Acinetobacter/mortalidade , Acinetobacter baumannii/classificação , Acinetobacter baumannii/genética , Acinetobacter calcoaceticus/classificação , Acinetobacter calcoaceticus/genética , Adulto , Idoso , Antibacterianos/farmacologia , Bacteriemia/epidemiologia , Bacteriemia/mortalidade , Feminino , Genótipo , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Tipagem Molecular , Técnica de Amplificação ao Acaso de DNA Polimórfico , Recidiva , Análise de Sequência de DNA , Análise de Sobrevida , Taiwan/epidemiologia
9.
Nephrol Dial Transplant ; 27(2): 752-7, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21617195

RESUMO

BACKGROUND: Colonoscopy is a common procedure for diagnosing and screening colon cancer and other bowel-related diseases. Many studies have pointed out that using phospho-soda as a bowel preparation can cause obvious electrolyte abnormalities or acute kidney injury. Nonetheless, there are few studies related to its prevalence and risk factors in the population undergoing health examinations. Our aim was to compare the biochemical and electrolyte changes after using two commonly used bowel preparation regimens in this population. METHODS: In this retrospective study, we collected data about participants who, before a screening colonoscopy, used oral phospho-soda laxatives in 2006, and those who used polyethylene glycol-based laxatives in 2005. Several serum biochemical and electrolyte profiles were compared between the two groups. Additional risk factors of hyperphosphatemia, a well-known side effect of phospho-soda, were also derived. RESULTS: We enrolled a total of 2270 participants (1321 in 2005; 1449 in 2006). The basic demographic data of the two groups were not statistically different. Nonetheless, between the two groups, some serum biochemical and electrolytic data differed significantly: in those using oral phospho-soda laxatives, we found a higher prevalence of hyperuricemia, hypocalcemia, hypokalemia, hypernatremia and hyperphosphatemia. Further analyses showed that using oral phospho-soda laxatives was a risk factor for hyperphosphatemia; conversely, being male was a protective factor. CONCLUSION: Oral phospho-soda laxatives indeed influence the biochemical and electrolyte profiles of persons undergoing health examinations. One should be careful when interpreting bioelectrolytic data while using phospho-soda as a bowel preparation.


Assuntos
Programas de Rastreamento/métodos , Fosfatos/efeitos adversos , Polietilenoglicóis/efeitos adversos , Desequilíbrio Hidroeletrolítico/induzido quimicamente , Desequilíbrio Hidroeletrolítico/epidemiologia , Administração Oral , Adulto , Distribuição por Idade , Idoso , Estudos de Coortes , Neoplasias do Colo/prevenção & controle , Colonoscopia/efeitos adversos , Colonoscopia/métodos , Feminino , Humanos , Incidência , Laxantes/administração & dosagem , Laxantes/efeitos adversos , Masculino , Programas de Rastreamento/efeitos adversos , Pessoa de Meia-Idade , Fosfatos/administração & dosagem , Polietilenoglicóis/administração & dosagem , Estudos Retrospectivos , Medição de Risco , Gestão da Segurança , Distribuição por Sexo , Taiwan , Irrigação Terapêutica/efeitos adversos , Irrigação Terapêutica/métodos , Desequilíbrio Hidroeletrolítico/fisiopatologia
10.
Curr Microbiol ; 65(3): 254-61, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22739662

RESUMO

Helicobacter pylori can efficiently capture iron either from free heme or heme-containing compounds in the iron-limited gastric mucosa. However, the heme iron utilization systems of H. pylori have not been fully described to date. To investigate the contribution of genes involved in heme-iron utilization, a gene homologous to frpB, encode by hp0876 in H. pylori ATCC 26695, was inactivated by homologous recombination. Δhp0876 showed no demonstrable growth defects in the presence of the various concentrations of free iron. Moreover, when hemoglobin or heme was supplied as the sole iron sources, Δhp0876 had growth curves similar to the wild-type strain. The growth competition experiments in vitro also showed that Δhp0876 retained the ability for iron acquisition. Furthermore, IL-8 production in human gastric epithelial cells co-cultured with Δhp0876 and wild-type strain was compared, and our results indicated that lack of HP0876 affected the IL-8 release. And Δhp0876 exhibited significantly increased adherence to gastric epithelial cells. Together, our data suggests that HP0876 is dispensable for H. pylori heme-iron uptake, but it may attenuate H. pylori adherence to gastric epithelial cells, which induced decreased production of H. pylori-induced IL-8 production in gastric epithelial cells.


Assuntos
Aderência Bacteriana/fisiologia , Mucosa Gástrica/microbiologia , Helicobacter pylori/fisiologia , Heme/metabolismo , Ferro/metabolismo , Aderência Bacteriana/genética , Proteínas da Membrana Bacteriana Externa/genética , Proteínas da Membrana Bacteriana Externa/metabolismo , Linhagem Celular , Contagem de Colônia Microbiana , Células Epiteliais/citologia , Células Epiteliais/microbiologia , Mucosa Gástrica/citologia , Técnicas de Inativação de Genes , Helicobacter pylori/genética , Helicobacter pylori/crescimento & desenvolvimento , Helicobacter pylori/metabolismo , Humanos , Reação em Cadeia da Polimerase em Tempo Real
11.
Sci Total Environ ; 850: 158005, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-35964741

RESUMO

Phytolith is a form of SiO2 in plants. Carbon can be sequestrated as phytolith-occluded carbon (PhytOC) during the formation of phytoliths. PhytOC is characterized by its high resistance to temperature, oxidation and decomposition under protection of phytoliths and can be stored in the soil for thousands of years. Soil also is a huge PhytOC sink; however, most studies focus on PhytOC storage in straw and other residues. Wheat is a major staple food crop accumulating high content of Si and distributed widely, while its potential for PhytOC is not clear. At present, PhytOC storage only considers on the average value, but not on the relationship between ecological factors and the spatial distribution of PhytOC sequestration. Climatic factors and soil physiochemical properties together affect the formation process and stability of phytoliths. In our study, we collected wheat straw and soil samples from 95 sites among five provinces to extract phytolith and PhytOC. We constructed XGBoost model to predict the spatial distribution of phytolith and PhytOC across the country using the national soil testing and formula fertilization nutrient dataset and climate data. As a result, soil physiochemical factors such as available silicon (Siavail), total carbon (Ctot) and total nitrogen (Ntot) and climate factors related to temperature and precipitation have a great positive impact on the production of phytoliths and PhytOC. Meanwhile, PhytOC storage in wheat ecosystems was estimated to be 7.59 × 106 t, which is equivalent to 27.83 Tg of CO2. In China, the distribution characteristics of phytoliths and PhytOC in wheat straw and soil display a trend of decrease from south to north. He'nan Province is the largest wheat production area, producing approximately 1.59 × 106 t PhytOC per year. Therefore, PhytOC is a stable CO2 sink pathway in the agricultural ecosystems, which is of great importance for mitigating climate warming.


Assuntos
Carbono , Triticum , Carbono/análise , Dióxido de Carbono/análise , Sequestro de Carbono , China , Ecossistema , Nitrogênio , Silício , Dióxido de Silício , Solo/química , Triticum/metabolismo
12.
J Clin Microbiol ; 49(9): 3329-31, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21734032
13.
J Antimicrob Chemother ; 66(8): 1839-46, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21653602

RESUMO

OBJECTIVES: To investigate the clinical impact of different genospecies of the Acinetobacter calcoaceticus-Acinetobacter baumannii complex (ACB complex; A. baumannii, Acinetobacter gen. sp. 13TU and Acinetobacter gen. sp. 3) on the severity of bacteraemia. METHODS: We retrospectively compared the clinical features and outcomes of patients with bacteraemia caused by A. baumannii, Acinetobacter gen. sp. 13TU or Acinetobacter gen. sp. 3. The genospecies were identified using oligonucleotide array sequence analysis (interspacer sequence), and the clonality of Acinetobacter gen. sp. 13TU and 3 isolates was determined by PFGE analysis. RESULTS: A total of 215 patients with bacteraemia due to ACB complex were evaluated. Among them, 117 (54.4%) had A. baumannii bacteraemia, 77 (35.8%) had Acinetobacter gen. sp. 13TU bacteraemia and 21 (9.8%) had Acinetobacter gen. sp. 3 bacteraemia. A. baumannii bacteraemia was associated with a higher 14 day mortality rate (P < 0.001), a higher 30 day mortality rate (P < 0.001) and a higher in-hospital mortality rate than bacteraemia due to Acinetobacter gen. sp. 13TU or Acinetobacter gen. sp. 3. Independent prognostic factors for the 30 day mortality included the Charlson co-morbidity index (P < 0.001) and Pitt bacteraemia score (P < 0.001). Bloodstream infection caused by a multidrug-resistant A. baumannii isolate appeared to be associated with a poor outcome (P = 0.069). There was no clonal spread of Acinetobacter gen. sp. 13TU or Acinetobacter gen. sp. 3 during the study period. CONCLUSIONS: Bacteraemia due to multidrug-resistant strains but not A. baumannii per se appears to be associated with poor outcome.


Assuntos
Infecções por Acinetobacter/mortalidade , Infecções por Acinetobacter/patologia , Acinetobacter/genética , Acinetobacter/patogenicidade , Bacteriemia/mortalidade , Bacteriemia/patologia , Acinetobacter/classificação , Acinetobacter/efeitos dos fármacos , Infecções por Acinetobacter/microbiologia , Adulto , Idoso , Antibacterianos/farmacologia , Bacteriemia/microbiologia , DNA Bacteriano/genética , Farmacorresistência Bacteriana Múltipla , Eletroforese em Gel de Campo Pulsado , Feminino , Genótipo , Humanos , Masculino , Análise em Microsséries , Pessoa de Meia-Idade , Tipagem Molecular , Prognóstico , Resultado do Tratamento
14.
J Antimicrob Chemother ; 66(6): 1374-82, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21436153

RESUMO

OBJECTIVES: This study investigated the correlation between antibiotic consumption and antimicrobial resistance in Gram-negative bacteria causing healthcare-associated infections at a university hospital in Taiwan from 2000 to 2009. METHODS: Disc susceptibility data of Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Serratia marcescens, Proteus spp., Pseudomonas aeruginosa, Acinetobacter spp., Stenotrophomonas maltophilia and other non-fermentative Gram-negative bacilli causing healthcare-associated infections were evaluated. Data on annual patient-days and annual consumption (defined daily doses per 1000 patient-days) of extended-spectrum cephalosporins, ß-lactam/ß-lactamase inhibitor combinations, carbapenems, aminoglycosides and fluoroquinolones were analysed. RESULTS: The trend of total consumption of extended-spectrum cephalosporins, ß-lactam/ß-lactamase inhibitor combinations, carbapenems, aminoglycosides and fluoroquinolones significantly increased between 2000 and 2003 and remained stable between 2004 and 2009. The decreasing use of gentamicin and amikacin in recent years was associated with increasing susceptibility of E. coli, E. cloacae, S. marcescens and P. aeruginosa to gentamicin, as well as increasing susceptibility of P. aeruginosa to amikacin. The use of piperacillin/tazobactam was positively correlated with the prevalence of piperacillin/tazobactam-resistant E. coli and S. maltophilia. In contrast, the use of cefotaxime and piperacillin/tazobactam was negatively correlated with the prevalence of cefotaxime-resistant E. coli and piperacillin/tazobactam-resistant S. maltophilia, respectively. The consumption of fluoroquinolones was positively correlated with the rates of ciprofloxacin-resistant E. coli, piperacillin/tazobactam-resistant P. aeruginosa and ceftazidime-resistant S. maltophilia. CONCLUSIONS: The relationship between antibiotic prescription and the rates of resistance for Gram-negative bacteria is complicated; every type of antimicrobial agent or even individual agent can have distinct associations with different pathogens.


Assuntos
Antibacterianos/uso terapêutico , Infecção Hospitalar/microbiologia , Farmacorresistência Bacteriana , Uso de Medicamentos/estatística & dados numéricos , Bactérias Gram-Negativas/efeitos dos fármacos , Infecções por Bactérias Gram-Negativas/microbiologia , Antibacterianos/farmacologia , Bactérias Gram-Negativas/isolamento & purificação , Hospitais Universitários , Humanos , Testes de Sensibilidade Microbiana , Taiwan
15.
Diagnostics (Basel) ; 11(8)2021 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-34441448

RESUMO

The current processes used in clinical microbiology laboratories take ~24 h for incubation to identify the bacteria after the blood culture has been confirmed as positive and fa further ~24 h to report the results of antimicrobial susceptibility tests (ASTs). Patients with suspected bloodstream infection are treated with empiric broad-spectrum antibiotics but delayed targeted antimicrobial therapy. This study aimed to develop a method with a significantly shortened turnaround time for clinical application by identifying the optimal incubation period of a subculture. A total of 188 positive blood culture samples obtained from Nov. 2019 to Aug. 2020 were included. Compared to the conventional 24-h incubation for bacterial identification, our approach achieved 96.1% and 97.4% identification accuracy after shortening the incubation time to 4.5 and 3.5 h for gram-positive (GP) and gram-negative (GN) bacterial samples, respectively. Samples from short-term incubation without any intermediate step or process were directly subjected to analysis with the Phoenix M50 AST. Compared to the conventional disk diffusion AST, the category agreements for GP (excluding Streptococcus spp.), Streptococcus spp., and GN bacterial samples were 91.8%, 97.5%, and 92.7%, respectively. Our approach significantly reduced the average turnaround time from 48 h to 28 h for reporting bacterial identity and decreased average AST from 72 h to 50.3 h compared to the conventional methods. Accordingly, this approach allows a physician to prescribe the appropriate antibiotic(s) ~21.7 h earlier, thereby improving patient outcomes.

16.
Emerg Infect Dis ; 16(2): 294-6, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20113563

RESUMO

To assess the species distribution and epidemiologic trends of nontuberculous mycobacteria, we examined isolates from patients in Taiwan. During 2000-2008, the proportion increased significantly from 32.3% to 49.8%. Associated disease incidence increased from 2.7 to 10.2 cases per 100,000 patients. Mycobacterium avium complex and M. abscessus were most frequently isolated.


Assuntos
Infecções por Mycobacterium não Tuberculosas/epidemiologia , Infecção por Mycobacterium avium-intracellulare/epidemiologia , Vigilância da População , Tuberculose Pulmonar/epidemiologia , Humanos , Incidência , Prevalência , Taiwan/epidemiologia
18.
J Antimicrob Chemother ; 65(8): 1792-8, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20511366

RESUMO

OBJECTIVES: To investigate the determinants of outcome in patients with persistent methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia. METHODS: All patients >or=18 years old with MRSA bacteraemia for >or=7 days from 2000 to 2008 treated at National Taiwan University Hospital were investigated. The associations of mortality with clinical characteristics, management and vancomycin MICs for serial MRSA isolates were analysed. RESULTS: Persistent MRSA bacteraemia occurred in 227 patients. Decreasing trends in the incidence of MRSA bacteraemia (P < 0.001) and persistent MRSA bacteraemia (P = 0.031) were found. Elevated vancomycin MICs for subsequent MRSA isolates were found in 49 (24.6%) of 199 patients, especially those with infective endocarditis (41.9% versus 21.4%; P = 0.027). Metastatic infection [odds ratio (OR) 5.23; 95% confidence interval (CI) 2.17-12.59; P < 0.001], congestive heart failure (OR 4.78; 95% CI 2.19-10.42; P < 0.001) and elevated vancomycin MICs for subsequent MRSA isolates (OR 3.21; 95% CI 1.46-7.07; P = 0.004) were independent predictors of MRSA-related mortality, while metastatic infection (OR 3.01; 95% CI 1.45-6.28, P = 0.003) and congestive heart failure (OR 2.85; 95% CI 1.44-5.56, P = 0.003) were predictors of 30 day mortality. No significant impact of empirical glycopeptide therapy on MRSA-related (P = 0.89) or 30 day mortality (P = 0.26) was found. The 30 day mortality rate was lower in patients who received complete foci eradication (35.6% versus 51.1%; P = 0.03). CONCLUSIONS: Congestive heart failure and metastatic infections were predictors of mortality. Isolates with decreased susceptibility to vancomycin that emerged during persistent MRSA bacteraemia were associated with mortality. Aggressive attempts to completely eradicate foci should be encouraged.


Assuntos
Bacteriemia/microbiologia , Bacteriemia/mortalidade , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/mortalidade , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/farmacologia , Feminino , Hospitais , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Prognóstico , Fatores de Risco , Taiwan , Vancomicina/farmacologia , Adulto Jovem
19.
Scand J Infect Dis ; 42(11-12): 851-6, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20608770

RESUMO

The interferon-γ enzyme-linked immunospot assay (ELISPOT) has been demonstrated to be useful in the diagnosis of active tuberculosis (TB). In this study we aimed to evaluate the diagnostic performance of the ELISPOT assay in cancer patients with suspected pulmonary TB. Eighty-one cancer patients with suspected pulmonary TB were prospectively enrolled from April 2007 to December 2008, to investigate the diagnostic sensitivity and specificity of the ELISPOT assay. Of the 38 patients with TB, 33 (86.8%) had positive ELISPOT results. Of the 43 patients without TB, the results of the ELISPOT assay were negative in 35 (81.3%) patients. The overall sensitivity was 86.8%, specificity 81.3%, positive predictive value 80.5% and negative predictive value 87.5%. No significant difference was noted for the diagnostic performance of the ELISPOT assay for diagnosing TB between solid cancer and haematological cancer patients. In addition, a quantitative study did not show that TB patients with solid cancers have a better response than haematological cancer patients as measured by spot-forming cells per 10(6) peripheral blood mononuclear cells after exposure to early secretory antigenic target 6 (ESAT-6) and culture filtrate protein 10 (CFP-10). In conclusion, the ELISPOT assay could be a useful supplementary tool for the diagnosis of pulmonary TB among cancer patients, irrespective of cancer type.


Assuntos
Técnicas Bacteriológicas/métodos , ELISPOT/métodos , Neoplasias/complicações , Tuberculose Pulmonar/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Humanos , Interferon gama/metabolismo , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sensibilidade e Especificidade , Adulto Jovem
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