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Aplicação de um modelo de redes neuronais na elaboração de mapas de susceptibilidade a movimentos de vertente : Um exemplo numa área a sul de Coimbra (Portugal Central); Use of an artificial neural network for analysis of the susceptibility to landslides : application to a sample area located at South of Coimbra (Central Portugal)

Dimuccio, Luca; Ferreira, Rui; Cunha, Lúcio
Fonte: Associação Portuguesa de Geomorfólogos Publicador: Associação Portuguesa de Geomorfólogos
Tipo: Artigo de Revista Científica
Português
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Na sequência de um primeiro trabalho sobre cartografia de riscos naturais através da utilização de ferramentas SIG, para uma pequena área a Sul de Coimbra, procura-se agora aprofundar a aplicação de novas metodologias de tratamento de informação (Redes Neuronais) que permitam superar algumas debilidades evidenciadas nessa primeira abordagem. Utilizou-se uma ferramenta SIG para criar uma base de dados espacial onde foi registada a localização dos movimentos ocorridos no Inverno de 2000/2001, as características topográficas da área (declive), o uso do solo e a litologia. Depois, procedeu-se ao treino do algoritmo da rede neuronal, confrontando as matrizes representativas das variáveis utilizadas com a matriz onde estavam registados os movimentos ocorridos. O mapa de susceptibilidade obtido, comparado com os elaborados através de outras metodologias para a mesma área, mostra uma concordância muito mais acentuada entre as metodologias qualitativas e a modelação baseada na rede neuronal, o que nos parece traduzir uma maior fiabilidade desta última metodologia relativamente aos métodos estatísticos antes utilizados.; After a first work on the cartography of natural risks through the use of GIS tools, that two of the authors had published in the magazine Territory n. 9 (2002)...

Candidemia epidemiology and susceptibility profile in the largest Brazilian teaching hospital complex

MOTTA, Adriana Lopes; ALMEIDA, Gisele Madeira Duboc de; ALMEIDA JÚNIOR, João Nóbrega de; BURATTINI, Marcelo Nascimento; ROSSI, Flávia
Fonte: Brazilian Society of Infectious Diseases Publicador: Brazilian Society of Infectious Diseases
Tipo: Artigo de Revista Científica
Português
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INTRODUCTION: Although the spectrum of fungi causing bloodstream fungal infections continues to expand, Candida spp. remains responsible for the majority of these cases. OBJECTIVE: The purpose of this study was to characterize the candidemia epidemiology, species distribution and antifungal susceptibility patterns at a Brazilian tertiary teaching public hospital with 2,500 beds. METHODS: Records from the microbiology laboratory were used to identify patients with positive blood cultures during 2006. The in vitro activity of amphotericin B, caspofungin, itraconazole, fluconazole, voricanozole, and posaconazole were determined using the Etest method. RESULTS: One hundred and thirty-six cases of candidemia were identified and 100 strains were available for antifungal susceptibility testing. The overall incidence of candidemia was 1.87 cases/1.000 admissions and 0.27 cases/1.000 patient-days. Among the patients, 58.1% were male, and the median age was 40 years old. C. albicans was the most common species (52.2%), followed by C. parapsilosis (22.1%), C. tropicalis (14.8%), and C. glabrata (6.6%). All strains were susceptible to amphotericin B with a MIC90 of 0.5 µg/mL. Overall susceptibility for voriconozole, fluconazole, and caspofungin was > 97% with a MIC90 of 0.064...

Prevalência e Susceptibilidade Antimicrobiana de Patógenos Causadores de Mastite em Rebanhos Leiteiros; Prevalence and antimicrobial susceptibility of pathogens causing mastitis in dairy herds

Beuron, Daniele Cristine
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 31/10/2012 Português
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Os objetivos do presente estudo foram: a) avaliar a frequência de isolamentos de patógenos causadores de mastite em rebanhos leiteiros comerciais; b) determinar a susceptibilidade antimicrobiana de Staphylococcus spp. e Streptococcus spp. isolados de casos de mastite subclínica c) avaliar o perfil de multirresistência de Staphylococcus spp. e Streptococcus spp. d) Detectar o gene mecA em Staphylococcus spp. resistentes a oxacilina/meticilina; e) avaliar a associação entre as práticas de manejo e tratamento de mastite e a susceptibilidade antimicrobiana de Staphylococcus aureus isolados de rebanhos leiteiros. Foram selecionados para o presente estudo 13 rebanhos leiteiros a partir de um total de 60 rebanhos vinculados a um laticínio da região de Pirassununga/SP. Questionários previamente formulados foram respondidos pelos responsáveis do rebanho para avaliar a associação entre as práticas de manejo e tratamento de mastite e a susceptibilidade antimicrobiana de S. aureus. Após a seleção dos rebanhos e aplicação dos questionários, 1069 amostras de leite compostas foram coletadas durante 24 meses, em quatro períodos para realização de cultura e identificação dos patógenos, testes de susceptibilidade antimicrobiana e detecção do gene mecA. Os testes de susceptibilidade foram realizados em todos os isolados de Staphylococcus spp. e em 50% de Streptococcus spp. selecionados aleatoriamente. Os antimicrobianos testados foram: ampicilina 10 mg; clindamicina 2 µg...

Comparação do perfil de suscetibilidade entre isolados clínicos de candida spp. orais e vulvovaginais no sul do Brasil; Comparison of susceptibility profile among clinical isolates of oral and vulvovaginal Candida spp. in southern Brazil

Dalazen, Daniela; Zanrosso, Danuza; Wanderley, Liliane; Silva, Nelci Lopes da; Fuentefria, Alexandre Meneghello
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: application/pdf
Português
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Introdução: Nos últimos anos, o oportunismo das candidíases vem se tornando cada vez mais recorrente e de difícil tratamento, principalmente em virtude da emergência de novas espécies, bem como devido à diminuição à suscetibilidade aos antifúngicos. O sucesso do tratamento das infecções causadas por Candida depende cada vez mais do conhecimento da espécie e do seu perfil de sensibilidade. Objetivos: Esse estudo teve por objetivo realizar uma investigação do perfil de suscetibilidade de amostras de candidíase oral e vulvovaginal, de pacientes residentes no oeste de Santa Catarina, aos antifúngicos anfotericina B, fluconazol e miconazol. Material e métodos: A suscetibilidade de 60 cepas de Candida spp. foi avaliada frente aos antifúngicos. As determinações das concentrações inibitórias mínimas e concentrações fungicidas mínimas foram realizadas com base no documento M27-A2 do Clinical and Laboratory Standards Institute (CLSI). Resultados: No presente estudo foi observado alto índice de resistência para o fluconazol e para a anfotericina B. O miconazol foi o antifúngico que demonstrou melhor eficácia sobre as cepas testadas. Discussão: As amostras dessa região do estado de Santa Catarina demonstram baixa suscetibilidade aos antifúngicos...

Microdilution procedure for antifungal susceptibility testing of Paracoccidioides brasiliensis to amphotericin B and itraconazole

Takahagi-Nakaira, E.; Sugizaki, M. F.; Peracoli, M. T. S.
Fonte: Universidade Estadual Paulista (UNESP), Centro de Estudos de Venenos e Animais Peçonhentos (CEVAP) Publicador: Universidade Estadual Paulista (UNESP), Centro de Estudos de Venenos e Animais Peçonhentos (CEVAP)
Tipo: Artigo de Revista Científica Formato: 718-731
Português
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Processo FAPESP: 02/12462-4; Processo FAPESP: 03/12743-0; In vitro tests employing microdilution to evaluate fungal susceptibility to antifungal drugs are already standardized for fermentative yeasts. However, studies on the susceptibility of dimorphic fungi such as Paracoccidioides brasiliensis employing this method are scarce. The present work introduced some modifications into antifungal susceptibility testing from the European Committee on Antimicrobial Susceptibility Testing (EUCAST), concerning broth medium and reading time, to determine minimal inhibitory concentration (MIC) of amphotericin B and itraconazole against Paracoccidioides brasiliensis. Yeast-like cells of P. brasiliensis (Pb18 strain) were tested for susceptibility to amphotericin B and itraconazole in RPMI 1640 medium, supplemented with 2% glucose and nitrogen source and incubated at 35 degrees C. The MIC of amphotericin B and itraconazole against Pb18 were respectively 0.25 mu g/mL and 0.002 mu g/mL. The results of minimal fungicidal concentration (MFC) showed that amphotericin B at 0.25 mu g/mL or higher concentrations displayed fungicidal activity against Pb18 while itraconazole at least 0.002 mu g/mL has a fungistatic effect on P. brasiliensis. In conclusion...

Association between the c.910A>G genetic variant of the XRCC1 gene and susceptibility to esophageal cancer in the Chinese Han population

Chen,X.Q.; Wang,F.; Zheng,Y.L.; Fan,Q.X.; Yue,D.L.; Ma,Z.J.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2013 Português
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Esophageal cancer (EC) is a common malignancy worldwide. The X-ray repair cross-complementing 1 gene (XRCC1) is one of the most important candidate genes for influencing susceptibility to EC. This study aimed to investigate the effect of XRCC1 genetic variants on susceptibility to EC. A total of 383 EC patients (males: 239, females: 144, mean age: 56.62) and 387 cancer-free controls (males: 251, females: 136, mean age: 58.23) were enrolled in this study. The c.910A>G genetic variant of the XRCC1 gene was determined by polymerase chain reaction-restriction fragment length polymorphism and DNA sequencing methods. The allele and genotype frequencies indicated statistical differences between EC patients and cancer-free controls. The c.910A>G genetic variant was statistically associated with increased susceptibility to EC [GG vs AA: odds ratio (OR)=1.79, 95% confidence interval (CI)=1.12-2.86, P=0.014; GG vs AG/AA: OR=1.76, 95%CI=1.13-2.75, P=0.013; G vs A: OR=1.25, 95%CI=1.01-1.55, P=0.041]. The allele G and genotype GG could contribute to the increased susceptibility to EC. Our findings suggest that the c.910A>G genetic variant is associated with susceptibility to EC in the Chinese Han population, and might be used as a molecular marker for detecting susceptibility to EC.

Candidemia epidemiology and susceptibility profile in the largest Brazilian teaching hospital complex

Motta,Adriana Lopes; Almeida,Gisele Madeira Duboc de; Almeida Júnior,João Nóbrega de; Burattini,Marcelo Nascimento; Rossi,Flávia
Fonte: Brazilian Society of Infectious Diseases Publicador: Brazilian Society of Infectious Diseases
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2010 Português
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INTRODUCTION: Although the spectrum of fungi causing bloodstream fungal infections continues to expand, Candida spp. remains responsible for the majority of these cases. OBJECTIVE: The purpose of this study was to characterize the candidemia epidemiology, species distribution and antifungal susceptibility patterns at a Brazilian tertiary teaching public hospital with 2,500 beds. METHODS: Records from the microbiology laboratory were used to identify patients with positive blood cultures during 2006. The in vitro activity of amphotericin B, caspofungin, itraconazole, fluconazole, voricanozole, and posaconazole were determined using the Etest method. RESULTS: One hundred and thirty-six cases of candidemia were identified and 100 strains were available for antifungal susceptibility testing. The overall incidence of candidemia was 1.87 cases/1.000 admissions and 0.27 cases/1.000 patient-days. Among the patients, 58.1% were male, and the median age was 40 years old. C. albicans was the most common species (52.2%), followed by C. parapsilosis (22.1%), C. tropicalis (14.8%), and C. glabrata (6.6%). All strains were susceptible to amphotericin B with a MIC90 of 0.5 µg/mL. Overall susceptibility for voriconozole, fluconazole, and caspofungin was > 97% with a MIC90 of 0.064...

Microdilution procedure for antifungal susceptibility testing of Paracoccidioides brasiliensis to amphotericin b and itraconazole

Takahagi-Nakaira,E; Sugizaki,MF; Peraçoli,MTS
Fonte: Centro de Estudos de Venenos e Animais Peçonhentos - CEVAP, Universidade Estadual Paulista - UNESP Publicador: Centro de Estudos de Venenos e Animais Peçonhentos - CEVAP, Universidade Estadual Paulista - UNESP
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2009 Português
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In vitro tests employing microdilution to evaluate fungal susceptibility to antifungal drugs are already standardized for fermentative yeasts. However, studies on the susceptibility of dimorphic fungi such as Paracoccidioides brasiliensis employing this method are scarce. The present work introduced some modifications into antifungal susceptibility testing from the European Committee on Antimicrobial Susceptibility Testing (EUCAST), concerning broth medium and reading time, to determine minimal inhibitory concentration (MIC) of amphotericin B and itraconazole against Paracoccidioides brasiliensis. Yeast-like cells of P. brasiliensis (Pb18 strain) were tested for susceptibility to amphotericin B and itraconazole in RPMI 1640 medium, supplemented with 2% glucose and nitrogen source and incubated at 35°C. The MIC of amphotericin B and itraconazole against Pb18 were respectively 0.25 µg/mL and 0.002 µg/mL. The results of minimal fungicidal concentration (MFC) showed that amphotericin B at 0.25 µg/mL or higher concentrations displayed fungicidal activity against Pb18 while itraconazole at least 0.002 µg/mL has a fungistatic effect on P. brasiliensis. In conclusion, our results showed that the method employed in the present study is reproducible and reliable for testing the susceptibility of P. brasiliensis to antifungal drugs.

Emergence of Reduced Susceptibility and Resistance to Fluoroquinolones in Escherichia coli in Taiwan and Contributions of Distinct Selective Pressures

McDonald, L. Clifford; Chen, Feng-Jui; Lo, Hsiu-Jung; Yin, Hsiao-Chuan; Lu, Po-Liang; Huang, Cheng-Hua; Chen, Pei; Lauderdale, Tsai-Ling; Ho, Monto
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /11/2001 Português
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A survey of 1,203 Escherichia coli isolates from 44 hospitals in Taiwan revealed that 136 (11.3%) isolates were resistant to fluoroquinolones and that another 261 (21.7%) isolates had reduced susceptibility. Resistance was more common in isolates responsible for hospital-acquired (mostly in intensive care units) infections (17.5%) than in other adult inpatient (11.4%; P = 0.08) and outpatient isolates (11.9%; P > 0.1). Similarly, reduced susceptibility was more common in isolates responsible for hospital-acquired infections (30.9%) than in other adult inpatient (21.0%; P = 0.04) and outpatient (21.4%; P = 0.06) isolates. Isolates from pediatric patients were less likely to be resistant (1.3 versus 12.0%; P < 0.01) but were nearly as likely to have reduced susceptibility (17.7 versus 21.9%; P > 0.1) as nonpediatric isolates. There was an inverse relationship in the proportion of isolates that were resistant versus the proportion that had reduced susceptibility among isolates from individual hospitals (R = 0.031; P < 0.05). In an analysis of isolates from two hospitals, all 9 resistant strains possessed double point mutations in gyrA and all 19 strains with reduced susceptibility strains had single point mutations; no mutations were found among fully susceptible strains. Risk factors for resistance included underlying cancer (odds ratio [OR]...

Diffusion Disk Susceptibility Testing with Cefaclor

Shadomy, Smith; Carver, Melinda
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /02/1978 Português
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The reliability of the standardized 30-μg cephalothin disk and that of an experimental 30-μg cefaclor disk in predicting probable clinical susceptibility to cefaclor were compared. Quantitative determinations of cefaclor susceptibility were measured by the World Health Organization International Collaborative Study agar dilution procedure; diffusion disk tests were performed by the standardized U.S. Food and Drug Administration disk test. The cephalothin disk erred in predicting probable susceptibility in 52% of isolates of Enterococcus spp. resistant to 16 μg or less of cefaclor per ml; the cefaclor disk did not. The cephalothin disk erred in correctly predicting susceptibility in only 20% of cefaclor-susceptible isolates of Enterobacter spp.; the cefaclor disk correctly predicted susceptibility for 70%. These results indicate the need for further evaluation of a separate cefaclor disk for use in susceptibility testing with this new cephalosporin.

Effect of Different Lots of Mueller-Hinton Agar on the Interpretation of the Gentamicin Susceptibility of Pseudomonas aeruginosa

Pollock, Helen M.; Minshew, Barbara H.; Kenny, Margaret A.; Schoenknecht, Fritz D.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /09/1978 Português
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Population distributions and quality control data for strains of Pseudomonas aeruginosa tested for gentamicin susceptibility on six lots of Mueller-Hinton agar were analyzed. The lots of agar were used in three University of Washington hospitals from April 1975 through October 1977. The analyses indicated that the performance of members of the P. aeruginosa populations in each hospital closely followed the performance of the quality control strain, P. aeruginosa ATCC 27853, when tested on each lot of Mueller-Hinton medium. The variability of zone diameters with the P. aeruginosa populations and the quality control strain indicated that a fixed indeterminate range (13 to 16 mm) of gentamicin susceptibility was not applicable to these organisms as it was with the Enterobacteriaceae. Variability in gentamicin susceptibility results was demonstrated in both minimal inhibitory concentration and disk diffusion tests when eight selected P. aeruginosa strains and the quality control strain were tested on each lot of medium. This variation in susceptibility to gentamicin was not related to the total Ca2+, Mg2+, or Zn2+ content of each lot of medium. The data demonstrated that a moving indeterminate range of gentamicin susceptibility, 3 to 6 mm below the mean zone diameter of the quality control strain...

Comparative Evaluation of the VITEK 2, Disk Diffusion, Etest, Broth Microdilution, and Agar Dilution Susceptibility Testing Methods for Colistin in Clinical Isolates, Including Heteroresistant Enterobacter cloacae and Acinetobacter baumannii Strains▿

Lo-Ten-Foe, Jerome R.; de Smet, Anne Marie G. A.; Diederen, Bram M. W.; Kluytmans, Jan A. J. W.; van Keulen, Peter H. J.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Português
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Increasing antibiotic resistance in gram-negative bacteria has recently renewed interest in colistin as a therapeutic option. The increasing use of colistin necessitates the availability of rapid and reliable methods for colistin susceptibility testing. We compared seven methods of colistin susceptibility testing (disk diffusion, agar dilution on Mueller-Hinton [MH] and Isosensitest agar, Etest on MH and Isosensitest agar, broth microdilution, and VITEK 2) on 102 clinical isolates collected from patient materials during a selective digestive decontamination or selective oral decontamination trial in an intensive-care unit. Disk diffusion is an unreliable method to measure susceptibility to colistin. High error rates and low levels of reproducibility were observed in the disk diffusion test. The colistin Etest, agar dilution, and the VITEK 2 showed a high level of agreement with the broth microdilution reference method. Heteroresistance for colistin was observed in six Enterobacter cloacae isolates and in one Acinetobacter baumannii isolate. This is the first report of heteroresistance to colistin in E. cloacae isolates. Resistance to colistin in these isolates seemed to be induced upon exposure to colistin rather than being caused by stable mutations. Heteroresistant isolates could be detected in the broth microdilution...

Introduction of Ertapenem into a Hospital Formulary: Effect on Antimicrobial Usage and Improved In Vitro Susceptibility of Pseudomonas aeruginosa▿

Goldstein, Ellie J. C.; Citron, Diane M.; Peraino, Victoria; Elgourt, Tanya; Meibohm, Anne R.; Lu, Shuang
Fonte: American Society for Microbiology (ASM) Publicador: American Society for Microbiology (ASM)
Tipo: Artigo de Revista Científica
Português
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After ertapenem was added to the formulary of a 344-bed community teaching hospital, we retrospectively studied its effect on antimicrobial utilization and on the in vitro susceptibility of various antimicrobial agents against Pseudomonas aeruginosa. Three study periods were defined as preintroduction (months 1 to 9), postintroduction but before the autosubstitution of ertapenem for ampicillin-sulbactam (months 10 to 18), and after the policy of autosubstitution (months 19 to 48) was initiated. Ertapenem usage rose slowly from introduction to a range of 36 to 48 defined daily doses/1,000 patient days (DDD) with a resultant decrease in ampicillin-sulbactam usage due to autosubstitution. Imipenem usage peaked 6 months after the introduction of ertapenem and started to decline coincidently with the increased use of ertapenem. During the second period, imipenem usage decreased (slope = −1.28; P = 0.002). Prior to the introduction of ertapenem, the susceptibility of P. aeruginosa to imipenem increased from 61 to 81% at month 7 but then decreased slightly to 67% at month 9. After the introduction of ertapenem, susceptibility continued to increase; the increasing trend was significant (slope = 1.74; P < 0.001). In the third period, the median susceptibility (interquartile range) was 88% (82 to 95%). This change appeared related to decreased imipenem usage. For every unit decrease in the monthly DDD of imipenem...

Trends towards Lower Antimicrobial Susceptibility and Characterization of Acquired Resistance among Clinical Isolates of Brachyspira hyodysenteriae in Spain ▿

Hidalgo, Álvaro; Carvajal, Ana; Vester, Birte; Pringle, Märit; Naharro, Germán; Rubio, Pedro
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /07/2011 Português
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The antimicrobial susceptibility of clinical isolates of Brachyspira hyodysenteriae in Spain was monitored, and the underlying molecular mechanisms of resistance were investigated. MICs of tylosin, tiamulin, valnemulin, lincomycin, and tylvalosin were determined for 87 B. hyodysenteriae isolates recovered from 2008 to 2009 by broth dilution. Domain V of the 23S rRNA gene and the ribosomal protein L3 gene were sequenced in 20 isolates for which the tiamulin MIC was ≥4 μg/ml, presenting decreased susceptibility, and in 18 tiamulin-susceptible isolates (MIC ≤ 0.125 μg/ml), and all isolates were typed by multiple-locus variable-number tandem repeats analysis. A comparison with antimicrobial susceptibility data from 2000 to 2007 showed an increase in pleuromutilin resistance over time, doubling the number of isolates with decreased susceptibility to tiamulin. No alteration in susceptibility was detected for lincomycin, and the MIC of tylosin remained high (MIC50 > 128 μg/ml). The decreased susceptibility to tylosin and lincomycin can be explained by mutations at position A2058 of the 23S rRNA gene (Escherichia coli numbering). A2058T was the predominant mutation, but A2058G also was found together with a change of the neighboring base pair at positions 2057 to 2611. The role of additional point mutations in the vicinity of the peptidyl transferase center and mutations in the L3 at amino acids 148 and 149 and their possible involvement in antimicrobial susceptibility are considered. An association between G2032A and high levels of tiamulin and lincomycin MICs was found...

Effect of pH on In Vitro Susceptibility of Candida glabrata and Candida albicans to 11 Antifungal Agents and Implications for Clinical Use

Danby, Claire S.; Boikov, Dina; Rautemaa-Richardson, Rina; Sobel, Jack D.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /03/2012 Português
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The treatment of vulvovaginal candidiasis (VVC) due to Candida glabrata is challenging, with limited therapeutic options. Unexplained disappointing clinical efficacy has been reported with systemic and topical azole antifungal agents in spite of in vitro susceptibility. Given that the vaginal pH of patients with VVC is unchanged at 4 to 4.5, we studied the effect of pH on the in vitro activity of 11 antifungal agents against 40 C. glabrata isolates and compared activity against 15 fluconazole-sensitive and 10 reduced-fluconazole-susceptibility C. albicans strains. In vitro susceptibility to flucytosine, fluconazole, voriconazole, posaconazole, itraconazole, ketoconazole, clotrimazole, miconazole, ciclopirox olamine, amphotericin B, and caspofungin was determined using the CLSI method for yeast susceptibility testing. Test media were buffered to pHs of 7, 6, 5, and 4. Under conditions of reduced pH, C. glabrata isolates remained susceptible to caspofungin and flucytosine; however, there was a dramatic increase in the MIC90 for amphotericin B and every azole drug tested. Although susceptible to other azole drugs tested at pH 7, C. albicans strains with reduced fluconazole susceptibility also demonstrated reduced susceptibility to amphotericin B and all azoles at pH 4. In contrast...

Susceptibility Profiles of Nocardia Isolates Based on Current Taxonomy

Schlaberg, Robert; Fisher, Mark A.; Hanson, Kimberley E.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /02/2014 Português
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The genus Nocardia has undergone rapid taxonomic expansion in recent years, and an increasing number of species are recognized as human pathogens. Many established species have predictable antimicrobial susceptibility profiles, but sufficient information is often not available for recently described organisms. Additionally, the effectiveness of sulfonamides as first-line drugs for Nocardia has recently been questioned. This led us to review antimicrobial susceptibility patterns for a large number of molecularly identified clinical isolates. Susceptibility results were available for 1,299 isolates representing 39 different species or complexes, including 11 that were newly described, during a 6-year study period. All tested isolates were susceptible to linezolid. Resistance to trimethoprim-sulfamethoxazole (TMP-SMX) was rare (2%) except among Nocardia pseudobrasiliensis (31%) strains and strains of the N. transvalensis complex (19%). Imipenem susceptibility varied for N. cyriacigeorgica and N. farcinica, as did ceftriaxone susceptibility of the N. nova complex. Resistance to more than one of the most commonly used drugs (amikacin, ceftriaxone, TMP-SMX, and imipenem) was highest for N. pseudobrasiliensis (100%), N. transvalensis complex (83%)...

Use of In Vitro Vancomycin Testing Results To Predict Susceptibility to Oritavancin, a New Long-Acting Lipoglycopeptide

Jones, Ronald N.; Turnidge, John D.; Moeck, Greg; Arhin, Francis F.; Mendes, Rodrigo E.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em 09/02/2015 Português
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Oritavancin is a recently approved lipoglycopeptide antimicrobial agent with activity against Gram-positive pathogens. Its extended serum elimination half-life and concentration-dependent killing enable single-dose treatment of acute bacterial skin and skin structure infections. At the time of regulatory approval, new agents, including oritavancin, are not offered in the most widely used susceptibility testing devices and therefore may require application of surrogate testing using a related antimicrobial to infer susceptibility. To evaluate vancomycin as a predictive susceptibility marker for oritavancin, 26,993 recent Gram-positive organisms from U.S. and European hospitals were tested using reference MIC methods. Organisms included Staphylococcus aureus, coagulase-negative staphylococci (CoNS), beta-hemolytic streptococci (BHS), viridans group streptococci (VGS), and enterococci (ENT). These five major pathogen groups were analyzed by comparing results with FDA-approved susceptible breakpoints for both drugs, as well as those suggested by epidemiological cutoff values and supported by pharmacokinetic/pharmacodynamic analyses. Vancomycin susceptibility was highly accurate (98.1 to 100.0%) as a surrogate for oritavancin susceptibility among the indicated pathogen species. Furthermore...

Genetic susceptibility and the link between cat exposure and rheumatoid arthritis

Penglis, P.; Bond, C.; Humphreys, I.; McCluskey, J.; Cleland, L.
Fonte: W B Saunders Co Publicador: W B Saunders Co
Tipo: Artigo de Revista Científica
Publicado em //2000 Português
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Objectives: Rheumatoid arthritis (RA) is a chronic inflammatory disease for which immunogenetic susceptibility factors have been defined. In a recent case control study, it was shown that a prior intimate relationship with pet cats or budgerigars confers risk for subsequent development of RA after a period of latency. Pets are a potential reservoir for putative microbial agents that could be a stimulus for chronic inflammation subject to the influence of immunogenetic factors. Therefore, a study was undertaken to determine whether the presence of HLA-DRB1 alleles bearing the RA susceptibility motif influenced risk for RA associated with prior exposure to pets. Methods: Blood samples were obtained from available RA patients and their case controls who had participated in the prior epidemiologic study. DR and DQ genotypes were determined by sequence analysis of oligonucleotides amplified from the DRB1 and DQB1 genes by polymerase chain reactions (PCR). Subjects were segregated according to pet exposure (as determined previously) and genotype for statistical analyses. Results: The odds ratio (OR) for prepubertal exposure to cats and RA in available subjects irrespective of DRB1 genotype was 4.2 (CI, 2.1 to 8.5; P <.00002). The OR between prior exposure to cats and RA in subjects with the RA susceptibility genotype DRB1 *0401 and *0404 was 5.8 (CI...

A descriptive analysis of the antimicrobial susceptibility of mastitis-causing bacteria isolated from samples submitted to commercial diagnostic laboratories in New Zealand (2003-2006)

Petrovski, K.; Laven, R.; Lopez-Villalobos, N.
Fonte: New Zealand Veterinary Assoc Inc Publicador: New Zealand Veterinary Assoc Inc
Tipo: Artigo de Revista Científica
Publicado em //2011 Português
Relevância na Pesquisa
36.442976%
AIM: To describe the antimicrobial susceptibility of mastitis-causing bacteria isolated from milk samples submitted to commercial laboratories over a period of 40 months. METHODS: The records of reported results of milk samples submitted by veterinary practitioners to five commercial veterinary laboratories in the North and South Islands of New Zealand, between August 2003 and December 2006 were reviewed. Logistic regression was used to analyse the effect of year, island, and the interaction of year and antimicrobial on the probability of antimicrobial susceptibility for each pathogen and antimicrobial combination, where the causative bacteria had >1,000 susceptibility tests in total and the antimicrobials was tested on >500 isolates. A total of 9,262 isolates were included in this study, with an average of nearly seven susceptibility tests per isolate, totalling 62,918 tests. RESULTS: Streptococcus uberis isolates demonstrated high overall susceptibility (>90.0%) to the majority of antimicrobial agents except ampicillin (81.7%), lincomycin (85.3%), trimethoprim/sulphonamide combination (88.6%), and, as expected, aminoglycosides (<4%). The susceptibility of Strep. dysgalactiae was similar to that of Strep. uberis, except for greater susceptibility to oxacillin (98.1%) and much lower susceptibility to tetracyclines (11.2%). The susceptibility of Staphylococcus aureus isolates was markedly different from that of Strep. uberis for the majority of antimicrobials tested. Susceptibility of Staph. aureus was lower than 90% to ampicillin (73.4%)...

Comparative study of top soil magnetic susceptibility variation based on some human activities

Kanu,M. O.; Meludu,O. C.; Oniku,S. A.
Fonte: Instituto de Geofísica, UNAM Publicador: Instituto de Geofísica, UNAM
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2014 Português
Relevância na Pesquisa
36.405127%
An investigation of the effect of some human activities on the magnetic susceptibility and frequency dependent susceptibility was conducted on top soil samples from, a commercial area, a motor park and a school environment in Jalingo, Taraba State, N-E Nigeria. The purpose was to assess the variation of magnetic susceptibility with different land use, detect pollution hotspots using magnetic proxy parameters and evaluate the contribution of superparamagnetic (SP) grain size contribution to the magnetic susceptibility from calculation of the frequency dependence of magnetic susceptibility (MS). The results of the mass specific low frequency magnetic susceptibility measurements showed significant enhancement with values ranging from 67.8 - 495.3 x 10-8 m³kg-1 with a mean value of 191.61 x 10-8 m³kg-1 for the Jalingo College of Education (JCOE) data; 520.1 - 1612.8 x 10-8 m³kg-1 with a mean value of 901.34 x 10-8 m³kg-1 for the Jalingo main Market (JMM) and 188.5- 1203.6 x 10-8m³kg-1 with an average value of 574 92 x 10-6 m³kg-1 for the Jalingo Motor Park (JMP). The significant magnetic enhancement indicates high concentration of ferrimagnetic minerals in the soil and hence increased pollution. The magnetic susceptibility of the different land use studied decreased in the order commercial area (market) > motor park > school premises. The results of the percentage frequency dependence susceptibility showed that most of the samples had a mixture of SP and coarse multi domain grains or SP grains < 0.05μm. The value of χfd% range from 2.68 to 13.80% with an average value of 8.67% in the JCOE samples...