34 results on '"Serpa R"'
Search Results
2. Farnesol increases the susceptibility of Burkholderia pseudomallei biofilm to antimicrobials used to treat melioidosis
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Castelo-Branco, D. S.C.M., Riello, G. B., Vasconcelos, D. C., Guedes, G. M.M., Serpa, R., Bandeira, T. J.P.G., Monteiro, A. J., Cordeiro, R. A., Rocha, M. F.G., Sidrim, J. J.C., and Brilhante, R. S.N.
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- 2016
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3. In vitro antifungal activity of miltefosine and levamisole: their impact on ergosterol biosynthesis and cell permeability of dimorphic fungi
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Brilhante, R. S.N., Caetano, E. P., Lima, R. A.C., Branco, Castelo D. S.C.M., Serpa, R., Oliveira, J. S., Monteiro, A. J., Rocha, M. F.G., Cordeiro, R. A., and Sidrim, J. J.C.
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- 2015
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4. Topographic Trace-Elemental Analysis in the Brain of Wistar Rats by X-ray Microfluorescence with Synchrotron Radiation
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Serpa, R. F. B., de JESUS, E. F. O., Anjos, M. J., de Oliveira, L. F., Marins, L. A., do Carmo, M. G. T., Corrêa, JUNIOR, J. D., Rocha, M. S., Lopes, R. T., and MARTINEZ, A. M. B.
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- 2008
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5. Elemental concentration in the cortex and hippocampus of Wistar rats by X-ray total reflection fluorescence with synchrotron radiation
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Serpa, R. F. B., De Jesus, E. F. O., Anjos, M. J., Lopes, R. T., do Carmo, M. G. T., Moreira, S., Rocha, M. S., and Martinez, A. M. B.
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- 2006
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6. Sichuan Finishing Strong: Safety and Social Performance Excellence in Decommissioning and Restoration
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Mota, J. F., additional, Rattananon, P.., additional, Zhou, X.., additional, Zhao, H. K., additional, Guo, F.., additional, Serpa, R.., additional, Yuan, B.., additional, and Lin, L.., additional
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- 2018
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7. Farnesol increases the susceptibility of Burkholderia pseudomallei biofilm to antimicrobials used to treat melioidosis
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Castelo-Branco, D. S. C. M., Riello, G. B., Vasconcelos, D. C., Guedes, G. M. M., Serpa, R., Bandeira, T. J. P. G., Monteiro, A. J., Cordeiro, R. A., Rocha, M. F. G., Sidrim, J. J. C., and Brilhante, R. S. N.
- Subjects
Burkholderia pseudomallei ,Biofilme - Abstract
Aims: The aim of this study was to analyse the in vitro activity of farnesol alone and combined with the antibacterial drugs amoxicillin, doxycycline, ceftazidime and sulfamethoxazole – trimethoprim against Burkholderia pseudomallei biofilms. Methods and Results: Susceptibility was assessed by the broth microdilution test and cell viability was re ad with the oxid ation–reduction indicator dye resazurin. The biofilms were evaluated through three microscopic techniques (optical, confocal and electronic microscopy). The minimum biofilm erradication concentration (MBEC) for farnesol was 75–2400 mmol l 1 . In addition, farnesol significantly reduced the MBEC values for ceftazidime, amoxicillin, doxycycline and sulfamethoxazole–trimethoprim by 256, 16, 4 and 4 times respectively (P < 005). Optical, confocal and electronic microscopic analyses of farnesol-treated B. pseudomallei biofilms demonstrated that this compound damages biofilm matrix, probably facilitating antimicrobial pe netration in the biofi lm stru cture. Conclusions: This study demonstrated the effectiveness of farnesol against B. pseudomallei biofilms and its potentiating effect on the activity of antibacterial drugs, in particular ceftazidime, amoxicillin, doxycycline and sulfamethoxazole–trimethoprim. Significance and Impact of the Study: The intrinsic antimicrobial resistance of B. pseudomallei is a serious challenge for the treatment of melioidosis. Thus, this paper reports the inhibitory potential of farnesol against B. pseudomallei biofilms, as well as highlights the favourable pharmacological interaction of farnesol with antibiotics tested, not only on cell viability, but also in the structural morphology of biofilms.
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- 2015
8. Differentiating apathy and depression in patients with dementia in Parkinson's disease
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Camargo, C., primary, Berbetz, F., additional, Jobbins, V., additional, Ladeira, M., additional, Serpa, R., additional, Sabattini, J., additional, and Young-Blood, M., additional
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- 2015
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9. Compatibility studies of entacapone with carbidopa, L-dopa, and pharmaceutical excipients for a fixed dose combination product
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Rodovalho-Mitani, L. F. F., Serpa, R. C., Marcilio Cunha Filho, and Lima, E. M.
10. Distal Transradial Access in the Anatomical Snuffbox for Interventional Coronary Procedures: Analysis of Access Site Pain and Complications.
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Barbosa RR, De Barros L, Sylvestre RC, Belloti VL, de Oliveira GF, Ferraz RD, de Aragão BP, Calil OA, Serpa R, and Barbosa LFM
- Abstract
Introduction: A novel arterial access distally on the radial artery through the anatomical snuffbox has been recently described for coronary interventional procedures. However, there is insufficient data comparing the advantages and limitations of distal transradial access (dTRA), conventional transradial access (TRA), and transfemoral access (TFA). The aim of this study was to compare the three access sites regarding local pain and complications during or after coronary interventional procedures., Methods: This prospective observational single-center study included 211 patients undergoing cardiac catheterization or percutaneous coronary intervention, divided into three groups: dTRA (n=69), TRA (n=71), and TFA (n=71). The access site was chosen at the discretion of three operators. We administered a questionnaire to all patients, addressing local pain or discomfort during or after the procedure and the occurrence of possible complications such as distal pallor, local bleeding, and purple color on the access site., Results: Pain on the access site during the procedure was reported more frequently in the TRA group (dTRA 15.9% vs. TRA 32.4% vs. TFA 15.5%). There were no differences in the occurrence of local pain after the procedure in all three groups (29.6% in the dTRA group, 28.2% in the TRA group, and 26.8% in the TFA group). Pain intensity, when it occurred, was higher in the dTRA group (dTRA 5.8 vs. TRA 4.8 vs. TFA 4.6 on a 1-10 scale), as was its duration (dTRA 13.7 vs. TRA 7.6 vs. TFA 8.2 days). Only two local bleeding events were reported, both in the TFA group. No major complications were recorded., Conclusion: The occurrence of local pain on the puncture site after coronary interventional procedures did not differ among the three groups. The dTRA group presented a lower incidence of pain during the procedure when compared to TRA and a lower incidence of purple color when compared to TFA. However, pain intensity and duration were higher in the dTRA group when pain was reported. Using dTRA for coronary procedures is a feasible and safe strategy in selected cases., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Barbosa et al.)
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- 2024
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11. Should Adolescents Run Marathons?: Youth Marathon Training Injury Epidemiology and Risk Factors.
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Goldman JT, Miller E, Runestad S, Serpa R, and Beck J
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- Adolescent, Humans, Lower Extremity injuries, Prospective Studies, Risk Factors, Marathon Running, Running injuries
- Abstract
Objective: Youth participation in distance running has increased, yet little data exist about the injury patterns and safety of such activity. This study seeks to determine the types and rates of injuries seen in an adolescent marathon training program., Design: Observational prospective cohort study., Setting: Community-based adolescent marathon training program., Participants: The study enrolled 1927 students from 50 high schools (HS) and 34 middle schools (MS) participating in the 2017 to 2018 Students Run Los Angeles marathon training program., Assessment of Risk Factors: Weekly injury reports completed by running coaches. Data elements included participant demographics, weekly training distance, injury type, injury acuity, and missed training time., Main Outcome Measures: Epidemiology of self-reported injury in adolescent runners., Results: A total of 583 injuries occurred in 18% of runners during the training program. High schools runners were more likely to be injured than MS runners (20.8% vs 14.2%, P < 0.001). Seventy-two percent of injuries were acute with a mean missed training time of 4.8 days (SD 4.8). The most frequent site of injury was the knee (33%). Overall, runners with injuries ran a significantly greater distance per week than uninjured runners (14.6 mi vs 12.0 mi, P < 0.001). Ninety-nine percent of marathon participants completed the race., Conclusions: During a 28-week marathon training program, 18% of adolescent participants reported an injury. More injuries occurred in HS students, were acute, and involved the knee. This study represents one of the largest descriptions of injury prevalence in adolescent distance running and highlights a lower injury rate than adults during marathon training., Competing Interests: The authors report no conflicts of interest., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)
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- 2022
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12. Prospective Study of Acute Opioid Use After Adolescent Anterior Cruciate Ligament Reconstruction Shows No Effect From Patient- or Surgical-Related Factors.
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Beck JJ, Cline K, Sangiorgio S, Serpa R, Shifflett KA, and Bowen RE
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- Acetaminophen administration & dosage, Adolescent, Age Factors, Child, Drug Therapy, Combination, Female, Humans, Male, Orthopedic Procedures, Pain Management, Patient Reported Outcome Measures, Prospective Studies, Plastic Surgery Procedures, Surveys and Questionnaires, Tablets, Analgesics, Opioid administration & dosage, Anterior Cruciate Ligament surgery, Drug Utilization statistics & numerical data, Hydrocodone administration & dosage, Pain, Postoperative drug therapy
- Abstract
Introduction: Patient-reported pain scores and opioid use have not been quantified after outpatient adolescent anterior cruciate ligament reconstruction (ACLR)., Methods: Patients aged 12 to 18 years undergoing primary isolated ACLR, with or without meniscal treatment, were prospectively recruited. Patients actively taking opioids or with previous extended use of opioids were excluded. Two orthopaedic surgeons performed ACLR and determined the use of a hamstring or bone-patellar tendon-bone autograft. For postoperative pain management, patients were prescribed 40 tablets of hydrocodone/acetaminophen 5/325 mg. Patients were instructed to document daily pill consumption and side effects through a daily log for 6 weeks. Patients completed the American Pain Society Patient Outcome Questionnaire at the end of weeks 1 and 6., Results: One hundred three patients were enrolled, with age: 12.5 to 18.9 years (mean 16.2 y ± 1.3), weight: 41.3 to 113.6 kg (mean 72.4 kg ± 17.2), and body mass index: 17.8 to 40.1 (mean 25.9 ± 4.9). Sixty-nine patients received a hamstring autograft, and 34 received a bone-patellar tendon-bone autograft. Fifty-six received additional meniscal procedures. The median number of postoperative opioids taken by patients was 17 (range 0 to 40). No notable differences were found in total pill consumption with regard to age, weight, body mass index, sex, block type, autograft type, or meniscal treatment at 1 week post-op or 6 weeks post-op. No correlation was found between the self-reported "worst pain in the past 24 hours" at the end of the first postoperative week or after 6 weeks (r = 0.112, P = 0.26, and r = 0.093, P = 0.36). No correlation was found between the level of satisfaction with pain treatment and total number of pills taken during the first postoperative week or at the end of 6 weeks (r = -0.090, P = 0.37, and r = -0.172, P = 0.08)., Conclusion: Patients take most pain medication during the first postoperative week after adolescent ACLR, although patient and surgical variables had no notable influence on pill consumption., Level of Evidence: Level IV, case series.
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- 2020
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13. Farnesol inhibits planktonic cells and antifungal-tolerant biofilms of Trichosporon asahii and Trichosporon inkin.
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Cordeiro RA, Pereira LMG, de Sousa JK, Serpa R, Andrade ARC, Portela FVM, Evangelista AJJ, Sales JA, Aguiar ALR, Mendes PBL, Brilhante RSN, Sidrim JJDC, Castelo-Branco DSCM, and Rocha MFG
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- Cell Adhesion drug effects, Humans, Metabolism drug effects, Peptide Hydrolases analysis, Trichosporon isolation & purification, Trichosporon metabolism, Trichosporonosis microbiology, Antifungal Agents pharmacology, Biofilms drug effects, Farnesol pharmacology, Trichosporon drug effects, Trichosporon growth & development
- Abstract
Trichosporon species have been considered important agents of opportunistic systemic infections, mainly among immunocompromised patients. Infections by Trichosporon spp. are generally associated with biofilm formation in invasive medical devices. These communities are resistant to therapeutic antifungals, and therefore the search for anti-biofilm molecules is necessary. This study evaluated the inhibitory effect of farnesol against planktonic and sessile cells of clinical Trichosporon asahii (n = 3) andTrichosporon inkin (n = 7) strains. Biofilms were evaluated during adhesion, development stages and after maturation for metabolic activity, biomass and protease activity, as well as regarding morphology and ultrastructure by optical microscopy, confocal laser scanning microscopy, and scanning electron microscopy. Farnesol inhibited Trichosporon planktonic growth by 80% at concentrations ranging from 600 to 1200 μM for T. asahii and from 75 to 600 μM for T. inkin. Farnesol was able to reduce cell adhesion by 80% at 300 μM for T. asahii and T. inkin at 600 μM, while biofilm development of both species was inhibited by 80% at concentration of 150 μM, altering their structure. After biofilm maturation, farnesol decreased T. asahii biofilm formation by 50% at 600 μM concentration and T. inkin formation at 300 μM. Farnesol inhibited gradual filamentation in a concentration range between 600 and 1200 μM. Farnesol caused reduction of filament structures of Trichosporon spp. at every stage of biofilm development analyzed. These data show the potential of farnesol as an anti-biofilm molecule., (© The Author(s) 2019. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology.)
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- 2019
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14. Comparison of high-power short-duration (HPSD) ablation of atrial fibrillation using a contact force-sensing catheter and conventional technique: Initial results.
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Vassallo F, Cunha C, Serpa E, Meigre LL, Carloni H, Simoes A Jr, Hespanhol D, Lovatto CV, Batista W Jr,, and Serpa R
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- Action Potentials, Aged, Atrial Fibrillation diagnosis, Atrial Fibrillation physiopathology, Cardiac Catheterization adverse effects, Catheter Ablation adverse effects, Equipment Design, Female, Heart Rate, Humans, Male, Middle Aged, Pulmonary Veins physiopathology, Recurrence, Retrospective Studies, Risk Factors, Time Factors, Treatment Outcome, Atrial Fibrillation surgery, Cardiac Catheterization instrumentation, Cardiac Catheters, Catheter Ablation instrumentation, Pulmonary Veins surgery, Transducers, Pressure
- Abstract
Introduction: Atrial fibrillation (AFib) ablation is alternative treatment to drugs. Literature suggests that use of contact force (CF) catheter with higher power for short periods is effective and safe., Methods/results: Retrospectively analyzed 76 patients undergoing the first ablation. Third five patients-group A: 27 (77%) paroxysmal AFib (PAFib) and 8 (23%) persistent AFib (PersAFib) who underwent ablation at the power of 30 W-17 mL/minute flow with a CF of 10-30 g for 30 seconds. Fourty one patients-group B: 28 (68.3%) PAFib and 13 (31.70%) PersAFib underwent ablation using 45 W on posterior wall with CF of 8/15 g, as well as 50-W anterior wall with CF of 10/20 g-35 mL/minute flow for 6 seconds. Pulmonary vein isolation in both groups and ablated. For patients not in the sinus, we performed cardioversion before ablation. No complications. Group A: Left atrial time 110 ± 29 minutes, total 148 ± 33.6 minutes, radiofrequency time (RF) 4558 ± 1998 seconds, X-ray 8.5 ± 3.5 minutes, and elevation of esophageal temperature (ET) in 26 (74.3%). group B: Left atrial time 70.7 ± 18.5 minutes ( P < .00001), total 106 ± 23 minutes ( P < .00001), RF 1909 ± 675.8 seconds ( P < .00001), X-ray 8.8 ± 6.6 minutes ( P = .221) and elevation of ET in 21 (51.20% - P = .0578). In 6 and 12 months follow-up, we had 9 (25.71%) and 11 (31.42%) recurrences in group A and 5 (12.19%) and 7 (17.07%) in group B ( P = .231 at 6 and P = .14 at 12 months), respectively., Conclusions: HPSD was safe, useful, and efficient compared with CT, and reduced procedural time and total RF time. HPSD may reduce esophageal injury because of lower heating rate and it may reduce the recurrence of atrial tachyarrythmias., (© 2019 Wiley Periodicals, Inc.)
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- 2019
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15. Cefepime and Amoxicillin Increase Metabolism and Enhance Caspofungin Tolerance of Candida albicans Biofilms.
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Cordeiro RA, Evangelista AJJ, Serpa R, de Andrade ARC, Mendes PBL, de Oliveira JS, de Alencar LP, Pereira VS, Lima-Neto RG, Brilhante RN, Sidrim JJC, Maia DCBSC, and Rocha MFG
- Abstract
It is well known that prolonged antibiotic therapy alters the mucosal microbiota composition, increasing the risk of invasive fungal infection (IFI) in immunocompromised patients. The present study investigated the direct effect of β-lactam antibiotics cefepime (CEF) and amoxicillin (AMOX) on biofilm production by Candida albicans ATCC 10231. Antibacterials at the peak plasmatic concentration of each drug were tested against biofilms grown on polystyrene surfaces. Biofilms were evaluated for biomass production, metabolic activity, carbohydrate and protein contents, proteolytic activity, ultrastructure, and tolerance to antifungals. CEF and AMOX enhanced biofilm production by C. albicans ATCC 10231, stimulating biomass production, metabolic activity, viable cell counts, and proteolytic activity, as well as increased biovolume and thickness of these structures. Nevertheless, AMOX induced more significant changes in C. albicans biofilms than CEF. In addition, it was shown that AMOX increased the amount of chitin in these biofilms, making them more tolerant to caspofungin. Finally, it was seen that, in response to AMOX, C. albicans biofilms produce Hsp70 - a protein with chaperone function related to stressful conditions. These results may have a direct impact on the pathophysiology of opportunistic IFIs in patients at risk.
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- 2019
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16. Exposure of Candida parapsilosis complex to agricultural azoles: An overview of the role of environmental determinants for the development of resistance.
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Brilhante RSN, Alencar LP, Bandeira SP, Sales JA, Evangelista AJJ, Serpa R, Cordeiro RA, Pereira-Neto WA, Sidrim JJC, Castelo-Branco DSCM, and Rocha MFG
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- Agriculture, Biofilms drug effects, Biofilms growth & development, Candida parapsilosis physiology, Chlorobenzenes, Microbial Sensitivity Tests, Triazoles, Antifungal Agents toxicity, Azoles toxicity, Candida parapsilosis drug effects
- Abstract
This work investigated the phenotypic behavior of Candida parapsilosis species complex in response to exposure to agricultural azoles and fluconazole. Three fluconazole-susceptible strains of C. parapsilosis sensu stricto, C. orthopsilosis and C. metapsilosis were used. Initial minimum inhibitory concentrations (iMICs) for agricultural and clinical azoles were determined by broth microdilution. Then, the strains were exposed to tebuconazole, tetraconazole and fluconazole for 15 days, at concentrations that were two-folded daily, starting at one-eighth the iMIC (iMIC/8) up to 64 times iMIC (64xiMIC). After 15-day-exposure, antifungal susceptibility, biofilm formation, CDR, MDR and ERG expression were evaluated. The three cryptic species developed tolerance to the antifungals they were exposed and presented reduction (P < 0.05) in fluconazole susceptibility. In addition, C. parapsilosis sensu stricto and C. metapsilosis also presented reduced susceptibility to voriconazole, after fluconazole exposure. Azole exposure decreased (P < 0.05) biofilm production by C. parapsilosis sensu stricto and C. orthopsilosis and increased (P < 0.05) the expression of ERG11 in all tested strains. The results show that exposure to agricultural azoles and fluconazole induces changes in the phenotypic behavior and gene expression by the three cryptic species of C. parapsilosis complex, highlighting the importance of environmental determinants for the development of antifungal resistance., (Copyright © 2018. Published by Elsevier B.V.)
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- 2019
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17. Phenotype-driven strategies for screening Candida parapsilosis complex for molecular identification.
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Cordeiro RA, Sales JA, Ponte YB, Mendes PBL, Serpa R, Evangelista AJ, Alencar LP, Pereira-Neto WA, Brilhante RSN, Sidrim JJC, Castelo-Branco DSCM, and Rocha MFG
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- Candida parapsilosis classification, Candida parapsilosis genetics, Candida parapsilosis growth & development, Culture Media metabolism, Humans, Phenotype, Polymerase Chain Reaction, Candida parapsilosis isolation & purification, Candidiasis microbiology, Mycological Typing Techniques methods
- Abstract
In this study, phenotypic methods presented >80% agreement with the molecular identification of 59 Candida parapsilosis complex. Growth at 15% NaCl or pH 7.0 significantly reduced cfu-counts of Candida orthopsilosis, suggesting these conditions may support the development of phenotypic methods for the differentiation of the cryptic species of C. parapsilosis complex., (Copyright © 2018 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.)
- Published
- 2018
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18. β-lactam antibiotics & vancomycin increase the growth & virulence of Candida spp.
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Aguiar Cordeiro R, de Jesus Evangelista AJ, Serpa R, Colares de Andrade AR, Leite Mendes PB, Silva Franco JD, de Oliveira JS, de Alencar LP, Sales JA, Carneiro Câmara LM, Souza Collares Maia Castelo-Branco D, Nogueira Brilhante RS, Costa Sidrim JJ, and Gadelha Rocha MF
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- Animals, Caenorhabditis elegans, Candida genetics, Candida growth & development, Humans, Microbial Sensitivity Tests, Virulence drug effects, Antifungal Agents pharmacology, Candida drug effects, Candida pathogenicity, Candidiasis microbiology, Vancomycin pharmacology, beta-Lactams pharmacology
- Abstract
Aim: To investigate the direct effect of antibiotics on growth and virulence of the major Candida species associated with invasive infections., Materials & Methods: Cefepime, imipenem, meropenem, amoxicillin and vancomycin were tested at twofold the peak plasma concentration (2× PP) and the peak plasma concentration (PP). The effects of antibiotics on Candida albicans, Candida parapsilosis, Candida krusei and Candida tropicalis were investigated by colony counting, flow cytometry, proteolytic activity and virulence in Caenorhabditis elegans., Results: Antibiotics increase growth and proteolytic activity of Candida spp; In addition, amoxicillin potentiates virulence of C. krusei and C. tropicalis against Caenorhabditis elegans., Conclusion: These results suggest that antimicrobial therapy may have a direct effect on the pathophysiology of invasive fungal infections in patients at risk.
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- 2018
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19. Antifungal susceptibility of Sporothrix schenckii complex biofilms.
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Brilhante RSN, de Aguiar FRM, da Silva MLQ, de Oliveira JS, de Camargo ZP, Rodrigues AM, Pereira VS, Serpa R, Castelo-Branco DSCM, Correia EEM, Pereira-Neto WA, Cordeiro RA, Rocha MFG, and Sidrim JJC
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- Humans, Microbial Sensitivity Tests, Antifungal Agents pharmacology, Biofilms drug effects, Biofilms growth & development, Sporothrix drug effects, Sporothrix physiology
- Abstract
Sporotrichosis, caused by species of Sporothrix schenckii complex, is the most prevalent subcutaneous mycosis in many areas of Latin America. The aim of this study was to evaluate the ability of Sporothrix spp. to form biofilms in vitro and to characterize the growth kinetics, morphology, and antifungal susceptibility of biofilms against classical antifungals. We investigated the ability of strains to produce biofilms in vitro and determined the effects of exposure to amphotericin B, itraconazole, caspofungin, ketoconazole, voriconazole, and fluconazole at minimum inhibitory concentration (MIC) against planktonic form and at 10× MIC and 50× MIC on the biomass and metabolic activity of these biofilms. Biofilm structure was analyzed by optical microscopy using Congo-red staining, confocal and scanning electron microscopy. Strains were classified for biofilm-forming ability, through the analysis of absorbance of crystal violet retained by biomass of mature biofilms. We found that all S. brasiliensis (n = 10), S. schenckii sensu stricto (n = 2), S. globosa (n = 2), and S. mexicana (n = 4) strains were strong biofilm-producers. The analyzed biofilms had dense network of hyphae and conidia immersed in extracellular matrix, with presence of water channels. Antifungal drugs at the three tested concentrations showed different effects on biomass and metabolic activity of biofilms. However, the best inhibitory response was observed with 50× MIC of amphotericin B and caspofungin, which reduced these parameters. Furthermore, high drug concentrations, especially amphotericin B and caspofungin, showed antifungal activity against these biofilms, probably because they damaged the architecture and extracellular matrix, allowing diffusion of the drugs.
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- 2018
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20. Inhibitory effect of a lipopeptide biosurfactant produced by Bacillus subtilis on planktonic and sessile cells of Trichosporon spp.
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Cordeiro RA, Weslley Caracas Cedro E, Raquel Colares Andrade A, Serpa R, José de Jesus Evangelista A, Sales de Oliveira J, Santos Pereira V, Pereira Alencar L, Bruna Leite Mendes P, Cibelle Soares Farias B, Maria Maciel Melo V, Pires de Camargo Z, de Souza Collares Maia Castelo-Branco D, Sâmia Nogueira Brilhante R, Júlio Costa Sidrim J, and Fábio Gadelha Rocha M
- Subjects
- Antifungal Agents metabolism, Biofilms growth & development, Lipopeptides biosynthesis, Plankton drug effects, Plankton metabolism, Plankton physiology, Surface-Active Agents pharmacology, Trichosporon metabolism, Trichosporon physiology, Antifungal Agents pharmacology, Bacillus subtilis metabolism, Cell Adhesion drug effects, Lipopeptides pharmacology, Trichosporon drug effects
- Abstract
The present study aimed to investigate the inhibitory effect of a bacterial biosurfactant (TIM96) on clinical strains of Trichosporon. Additionally, the effect of TIM96 on the ergosterol content, cell membrane integrity, and the hydrophobicity of planktonic cells was assessed. The inhibitory activity of TIM96 against Trichosporon biofilms was evaluated by analyzing metabolic activity, biomass and morphology. MIC values ranged from 78.125 to 312.5 μg ml
-1 for TIM96; time-kill curves revealed that the decline in the number of fungal cells started after incubation for 6 h with TIM96 at both MIC and 2×MIC. The biosurfactant reduced the cellular ergosterol content and altered the membrane permeability and the surface hydrophobicity of planktonic cells. Incubation at 10×MIC TIM96 reduced cell adhesion by up to 96.89%, thus interfering with biofilm formation. This concentration also caused up to a 99.2% reduction in the metabolic activity of mature biofilms. The results indicate potential perspectives for the development of new antifungal strategies.- Published
- 2018
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21. Repeat Mild Traumatic Brain Injury in Adolescent Rats Increases Subsequent β-Amyloid Pathogenesis.
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Grant DA, Serpa R, Moattari CR, Brown A, Greco T, Prins ML, and Teng E
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- Amyloid beta-Protein Precursor genetics, Amyloid beta-Protein Precursor metabolism, Animals, Female, Humans, Male, Rats, Rats, Transgenic, Brain pathology, Brain Concussion pathology, Plaque, Amyloid pathology
- Abstract
Single moderate-to-severe traumatic brain injuries (TBIs) may increase subsequent risk for neurodegenerative disease by facilitating β-amyloid (Aβ) deposition. However, the chronic effects on Aβ pathogenesis of repetitive mild TBIs (rTBI), which are common in adolescents and young adults, remain uncertain. We examined the effects of rTBI sustained during adolescence on subsequent deposition of Aβ pathology in a transgenic APP/PS1 rat model. Transgenic rats received sham or four individual mild TBIs (rTBIs) separated by either 24- or 72-h intervals at post-natal day 35 (before Aβ plaque deposition). Animals were euthanized at 12 months of age and underwent immunohistochemical analyses of Aβ plaque deposition. Significantly greater hippocampal Aβ plaque deposition was observed after rTBI separated by 24 h relative to rTBI separated by 72 h or sham injuries. These increases in hippocampal Aβ plaque load were driven by increases in both plaque number and size. Similar, though less-pronounced, effects were observed in extrahippocampal regions. Increases in Aβ plaque deposition were observed both ipsilaterally and contralaterally to the injury site and in both males and females. rTBIs sustained in adolescence can increase subsequent deposition of Aβ pathology, and these effects are critically dependent on interinjury interval.
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- 2018
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22. The HIV aspartyl protease inhibitor ritonavir impairs planktonic growth, biofilm formation and proteolytic activity in Trichosporon spp.
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Cordeiro RA, Serpa R, Mendes PBL, Evangelista AJJ, Andrade ARC, Franco JDS, Pereira VDS, Alencar LP, Oliveira JS, Camargo ZP, Lima Neto RG, Castelo-Branco DSCM, Brilhante RSN, Rocha MFG, and Sidrim JJC
- Subjects
- Biofilms growth & development, Drug Interactions, Microbial Sensitivity Tests, Peptide Hydrolases metabolism, Plankton growth & development, Plankton metabolism, Trichosporon growth & development, Trichosporon metabolism, Antifungal Agents pharmacology, Biofilms drug effects, HIV Protease Inhibitors pharmacology, Plankton drug effects, Ritonavir pharmacology, Trichosporon drug effects
- Abstract
This study evaluated the effect of the protease inhibitor ritonavir (RIT) on Trichosporon asahii and Trichosporon inkin. Susceptibility to RIT was assessed by the broth microdilution assay and the effect of RIT on protease activity was evaluated using azoalbumin as substrate. RIT was tested for its anti-biofilm properties and RIT-treated biofilms were assessed regarding protease activity, ultrastructure and matrix composition. In addition, antifungal susceptibility, surface hydrophobicity and biofilm formation were evaluated after pre-incubation of planktonic cells with RIT for 15 days. RIT (200 μg ml
-1 ) inhibited Trichosporon growth. RIT (100 μg ml-1 ) also reduced protease activity of planktonic and biofilm cells, decreased cell adhesion and biofilm formation, and altered the structure of the biofilm and the protein composition of the biofilm matrix. Pre-incubation with RIT (100 μg ml-1 ) increased the susceptibility to amphotericin B, and reduced surface hydrophobicity and cell adhesion. These results highlight the importance of proteases as promising therapeutic targets and reinforce the antifungal potential of protease inhibitors.- Published
- 2017
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23. Carbon nanotubes accelerate methane production in pure cultures of methanogens and in a syntrophic coculture.
- Author
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Salvador AF, Martins G, Melle-Franco M, Serpa R, Stams AJM, Cavaleiro AJ, Pereira MA, and Alves MM
- Subjects
- Butyrates chemistry, Coculture Techniques, Electron Transport physiology, Bacteria, Anaerobic metabolism, Methane biosynthesis, Methanobacterium metabolism, Methanospirillum metabolism, Nanotubes, Carbon chemistry
- Abstract
Carbon materials have been reported to facilitate direct interspecies electron transfer (DIET) between bacteria and methanogens improving methane production in anaerobic processes. In this work, the effect of increasing concentrations of carbon nanotubes (CNT) on the activity of pure cultures of methanogens and on typical fatty acid-degrading syntrophic methanogenic coculture was evaluated. CNT affected methane production by methanogenic cultures, although acceleration was higher for hydrogenotrophic methanogens than for acetoclastic methanogens or syntrophic coculture. Interestingly, the initial methane production rate (IMPR) by Methanobacterium formicicum cultures increased 17 times with 5 g·L
-1 CNT. Butyrate conversion to methane by Syntrophomonas wolfei and Methanospirillum hungatei was enhanced (∼1.5 times) in the presence of CNT (5 g·L-1 ), but indications of DIET were not obtained. Increasing CNT concentrations resulted in more negative redox potentials in the anaerobic microcosms. Remarkably, without a reducing agent but in the presence of CNT, the IMPR was higher than in incubations with reducing agent. No growth was observed without reducing agent and without CNT. This finding is important to re-frame discussions and re-interpret data on the role of conductive materials as mediators of DIET in anaerobic communities. It also opens new challenges to improve methane production in engineered methanogenic processes., (© 2017 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.)- Published
- 2017
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24. Promethazine improves antibiotic efficacy and disrupts biofilms of Burkholderia pseudomallei.
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Sidrim JJ, Vasconcelos DC, Riello GB, Guedes GM, Serpa R, Bandeira TJ, Monteiro AJ, Cordeiro RA, Castelo-Branco DS, Rocha MF, and Brilhante RS
- Subjects
- Burkholderia pseudomallei physiology, Drug Synergism, Microbial Sensitivity Tests, Plankton drug effects, Anti-Bacterial Agents pharmacology, Biofilms drug effects, Burkholderia pseudomallei drug effects, Promethazine pharmacology
- Abstract
Efflux pumps are important defense mechanisms against antimicrobial drugs and maintenance of Burkholderia pseudomallei biofilms. This study evaluated the effect of the efflux pump inhibitor promethazine on the structure and antimicrobial susceptibility of B. pseudomallei biofilms. Susceptibility of planktonic cells and biofilms to promethazine alone and combined with antimicrobials was assessed by the broth microdilution test and biofilm metabolic activity was determined with resazurin. The effect of promethazine on 48 h-grown biofilms was also evaluated through confocal and electronic microscopy. The minimum inhibitory concentration (MIC) of promethazine was 780 mg l
-1 , while the minimum biofilm elimination concentration (MBEC) was 780-3,120 mg l-1 . Promethazine reduced the MIC values for erythromycin, trimethoprim/sulfamethoxazole, gentamicin and ciprofloxacin and reduced the MBEC values for all tested drugs (p<0.05). Microscopic analyses demonstrated that promethazine altered the biofilm structure of B. pseudomallei, even at subinhibitory concentrations, possibly facilitating antibiotic penetration. Promethazine improves antibiotics efficacy against B. pseudomallei biofilms, by disrupting biofilm structure.- Published
- 2017
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25. Synthesis and in vitro antifungal activity of isoniazid-derived hydrazones against Coccidioides posadasii.
- Author
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Cordeiro Rde A, de Melo CV, Marques FJ, Serpa R, Evangelista AJ, Caetano EP, Mafezoli J, de Oliveira Mda C, da Silva MR, Bandeira Tde J, Moreira JL, Brilhante RS, Rocha MF, and Sidrim JJ
- Subjects
- Amphotericin B pharmacology, Biosynthetic Pathways drug effects, Cell Membrane drug effects, Drug Synergism, Ergosterol biosynthesis, Itraconazole pharmacology, Microbial Sensitivity Tests, Models, Molecular, Molecular Structure, Permeability drug effects, Antifungal Agents chemical synthesis, Antifungal Agents pharmacology, Coccidioides drug effects, Hydrazones chemical synthesis, Hydrazones pharmacology
- Abstract
Coccidioidomycosis is a potentially severe infection caused by dimorphic fungi Coccidioides immitis and Coccidioides posadasii. Although guidelines are well established, refractory disease is a matter of concern in the clinical management of coccidioidomycosis. In the present study three isoniazid-derived hydrazones N'-[(E)-1-(4-methoxyphenyl)ethylidene]pyridine-4-carbohydrazide, N'-[(E)-1-(4-methylphenyl)ethylidene]pyridine-4-carbohydrazide, and N'-[(E)-1-(phenyl)ethylidene]pyridine-4-carbohydrazide were synthesized and evaluated for antifungal activity against C. posadasii. Susceptibility assays were performed by macrodilution testing. Interactions between the hydrazones and amphotericin B or itraconazole were evaluated by the checkerboard method. We also investigated the impairment of such compounds on cell ergosterol and membrane integrity. The synthesized molecules were able to inhibit C. posadasii in vitro with MIC values that ranged from 25 to 400 μg/mL. Drug interactions between synthesized molecules and amphotericin B proved synergistic for the majority of tested isolates; regarding itraconazole, synergism was observed only when strains were tested against N'-[(E)-1-(phenyl)ethylidene]pyridine-4-carbohydrazide. Reduction of cellular ergosterol was observed when strains were challenged with the hydrazones alone or combined with antifungals. Only N'-[(E)-1-(4-methylphenyl)ethylidene]pyridine-4-carbohydrazide altered membrane permeability of C. posadasii cells. Isoniazid-derived hydrazones were able to inhibit C. posadasii cells causing reduction of ergosterol content and alterations in the permeability of cell membrane. This study confirms the antifungal potential of hydrazones against pathogenic fungi., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2016
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26. Candida tropicalis from veterinary and human sources shows similar in vitro hemolytic activity, antifungal biofilm susceptibility and pathogenesis against Caenorhabditis elegans.
- Author
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Brilhante RSN, Oliveira JS, Evangelista AJJ, Serpa R, Silva ALD, Aguiar FRM, Pereira VS, Castelo-Branco DSCM, Pereira-Neto WA, Cordeiro RA, Sidrim JJC, and Rocha MFG
- Subjects
- Animals, Candidiasis microbiology, Drug Resistance, Fungal, Humans, Antifungal Agents pharmacology, Biofilms drug effects, Caenorhabditis elegans microbiology, Candida tropicalis physiology, Candidiasis veterinary
- Abstract
The aim of this study was to evaluate the in vitro hemolytic activity and biofilm antifungal susceptibility of veterinary and human Candida tropicalis strains, as well as their pathogenesis against Caenorhabditis elegans. Twenty veterinary isolates and 20 human clinical isolates of C. tropicalis were used. The strains were evaluated for their hemolytic activity and biofilm production. Biofilm susceptibility to itraconazole, fluconazole, voriconazole, amphotericin B and caspofungin was assessed using broth microdilution assay. The in vivo evaluation of strain pathogenicity was investigated using the nematode C. elegans. Hemolytic factor was observed in 95% of the strains and 97.5% of the isolates showed ability to form biofilm. Caspofungin and amphotericin B showed better results than azole antifungals against mature biofilms. Paradoxical effect on mature biofilm metabolic activity was observed at elevated concentrations of caspofungin (8-64μg/mL). Azole antifungals were not able to inhibit mature C. tropicalis biofilms, even at the higher tested concentrations. High mortality rates of C. elegans were observed when the worms were exposed to with C. tropicalis strains, reaching up to 96%, 96h after exposure of the worms to C. tropicalis strains. These results reinforce the high pathogenicity of C. tropicalis from veterinary and human sources and show the effectiveness of caspofungin and amphotericin B against mature biofilms of this species., (Copyright © 2016 Elsevier B.V. All rights reserved.)
- Published
- 2016
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27. Inhibition of heat-shock protein 90 enhances the susceptibility to antifungals and reduces the virulence of Cryptococcus neoformans/Cryptococcus gattii species complex.
- Author
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Cordeiro RA, Evangelista AJJ, Serpa R, Marques FJF, Melo CVS, Oliveira JS, Franco JDS, Alencar LP, Bandeira TJPG, Brilhante RSN, Sidrim JJC, and Rocha MFG
- Subjects
- Amphotericin B pharmacology, Animals, Biofilms drug effects, Cell Membrane drug effects, Cryptococcosis drug therapy, Cryptococcosis microbiology, Cryptococcosis pathology, Cryptococcus gattii growth & development, Cryptococcus neoformans growth & development, Ergosterol metabolism, Fluconazole pharmacology, Humans, Itraconazole pharmacology, Melanins biosynthesis, Microbial Sensitivity Tests, Voriconazole pharmacology, Antifungal Agents pharmacology, Biofilms growth & development, Caenorhabditis elegans microbiology, Cryptococcus gattii pathogenicity, Cryptococcus neoformans pathogenicity, HSP90 Heat-Shock Proteins antagonists & inhibitors, Plankton drug effects
- Abstract
Heat-shock proteins (Hsps) are chaperones required for the maintenance of cellular homeostasis in different fungal pathogens, playing an important role in the infectious process. This study investigated the effect of pharmacological inhibition of Hsp90 by radicicol on the Cryptococcus neoformans/Cryptococcus gattii species complex--agents of the most common life-threatening fungal infection amongst immunocompromised patients. The influence of Hsp90 inhibition was investigated regarding in vitro susceptibility to antifungal agents of planktonic and sessile cells, ergosterol concentration, cell membrane integrity, growth at 37 °C, production of virulence factors in vitro, and experimental infection in Caenorhabditis elegans. Hsp90 inhibition inhibited the in vitro growth of planktonic cells of Cryptococcus spp. at concentrations ranging from 0.5 to 2 μg ml(-1) and increased the in vitro inhibitory effect of azoles, especially fluconazole (FLC) (P < 0.05). Inhibition of Hsp90 also increased the antifungal activity of azoles against biofilm formation and mature biofilms of Cryptococcus spp., notably for Cryptococcus gattii. Furthermore, Hsp90 inhibition compromised the permeability of the cell membrane, and reduced planktonic growth at 37 °C and the capsular size of Cryptococcus spp. In addition, Hsp90 inhibition enhanced the antifungal activity of FLC during experimental infection using Caenorhabditis elegans. Therefore, our results indicate that Hsp90 inhibition can be an important strategy in the development of new antifungal drugs.
- Published
- 2016
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28. Trichosporon inkin biofilms produce extracellular proteases and exhibit resistance to antifungals.
- Author
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de Aguiar Cordeiro R, Serpa R, Flávia Uchoa Alexandre C, de Farias Marques FJ, Vladia Silva de Melo C, da Silva Franco J, José de Jesus Evangelista A, Pires de Camargo Z, Samia Nogueira Brilhante R, Fabio Gadelha Rocha M, Luciano Bezerra Moreira J, de Jesus Pinheiro Gomes Bandeira T, and Júlio Costa Sidrim J
- Subjects
- Extracellular Space genetics, Fungal Proteins genetics, Humans, Microbial Sensitivity Tests, Peptide Hydrolases genetics, Trichosporon drug effects, Trichosporon genetics, Trichosporon physiology, Antifungal Agents pharmacology, Biofilms, Drug Resistance, Fungal, Extracellular Space enzymology, Fungal Proteins metabolism, Peptide Hydrolases metabolism, Trichosporon enzymology
- Abstract
The aim of this study was to determine experimental conditions for in vitro biofilm formation of clinical isolates of Trichosporon inkin, an important opportunistic pathogen in immunocompromised patients. Biofilms were formed in microtitre plates in three different media (RPMI, Sabouraud and CLED), with inocula of 104, 105 or 106 cells ml- 1, at pH 5.5 and 7.0, and at 35 and 28 °C, under static and shaking conditions for 72 h. Growth kinetics of biofilms were evaluated at 6, 24, 48 and 72 h. Biofilm milieu analysis were assessed by counting viable cells and quantification of nucleic acids released into biofilm supernatants. Biofilms were also analysed for proteolytic activity and antifungal resistance against amphotericin B, caspofungin, fluconazole, itraconazole and voriconazole. Finally, ultrastructural characterization of biofilms formed in microtitre plates and catheter disks was performed by scanning electron microscopy. Greater biofilm formation was observed with a starter inoculum of 106 cells ml- 1, at pH 7.0 at 35 °C and 80 r.p.m., in both RPMI and Sabouraud media. Growth kinetics showed an increase in both viable cells and biomass with increasing incubation time, with maximum production at 48 h. Biofilms were able to disperse viable cells and nucleic acids into the supernatant throughout the developmental cycle. T. inkin biofilms produced more protease than planktonic cells and showed high tolerance to amphotericin B, caspofungin and azole derivatives. Mature biofilms were formed by different morphotypes, such as blastoconidia, arthroconidia and hyphae, in a strain-specific manner. The present article details the multicellular lifestyle of T. inkin and provides perspectives for further research.
- Published
- 2015
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29. Inhibitory activity of isoniazid and ethionamide against Cryptococcus biofilms.
- Author
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Cordeiro Rde A, Serpa R, Marques FJ, de Melo CV, Evangelista AJ, Mota VF, Brilhante RS, Bandeira Tde J, Rocha MF, and Sidrim JJ
- Subjects
- Antifungal Agents pharmacology, Cell Membrane Permeability, Ergosterol chemistry, Fluconazole pharmacology, Microbial Sensitivity Tests, Biofilms drug effects, Cryptococcus gattii drug effects, Cryptococcus neoformans drug effects, Ethionamide pharmacology, Isoniazid pharmacology
- Abstract
In recent years, the search for drugs to treat systemic and opportunistic mycoses has attracted great interest from the scientific community. This study evaluated the in vitro inhibitory effect of the antituberculosis drugs isoniazid and ethionamide alone and combined with itraconazole and fluconazole against biofilms of Cryptococcus neoformans and Cryptococcus gattii. Antimicrobials were tested at defined concentrations after susceptibility assays with Cryptococcus planktonic cells. In addition, we investigated the synergistic interaction of antituberculosis drugs and azole derivatives against Cryptococcus planktonic cells, as well as the influence of isoniazid and ethionamide on ergosterol content and cell membrane permeability. Isoniazid and ethionamide inhibited both biofilm formation and viability of mature biofilms. Combinations formed by antituberculosis drugs and azoles proved synergic against both planktonic and sessile cells, showing an ability to reduce Cryptococcus biofilms by approximately 50%. Furthermore, isoniazid and ethionamide reduced the content of ergosterol in Cryptococcus spp. planktonic cells and destabilized or permeabilized the fungal cell membrane, leading to leakage of macromolecules. Owing to the paucity of drugs able to inhibit Cryptococcus biofilms, we believe that the results presented here might be of interest in the designing of new antifungal compounds.
- Published
- 2015
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30. Somatic mutations are not observed by exome sequencing of lymphocyte DNA from monozygotic twins discordant for congenital hypothyroidism due to thyroid dysgenesis.
- Author
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Magne F, Serpa R, Van Vliet G, Samuels ME, and Deladoëy J
- Subjects
- DNA genetics, Female, High-Throughput Nucleotide Sequencing, Humans, Male, Congenital Hypothyroidism genetics, Exome, Mutation, Thyroid Dysgenesis genetics, Twins, Monozygotic
- Abstract
Background/aims: Congenital primary hypothyroidism (CH) is a rare pediatric disorder estimated to occur in about 1:2,500 live births. Approximately half of these cases entail ectopic thyroid tissue, which is believed to result from a migration defect during embryogenesis. Approximately 3% of CH cases are explained by mutation(s) in known genes, most of which are transcription factors implicated in the embryology of the thyroid gland. Surprisingly, monozygotic (MZ) twins are usually discordant for CH due to thyroid dysgenesis, suggesting that most cases are not caused by transmitted genetic variation. One possible explanation is somatic mutation in genes involved in thyroid migration occurring after zygotic twinning. Such mutations should be observed only in the affected twin., Methods: To test the hypothesis of somatic mutation, we performed whole exome sequencing of DNA from three pairs of MZ twins discordant for CH with ectopic glands., Results: We found no somatic mutations exclusive to any of the three affected twins or in any of the unaffected twins., Conclusion: Either somatic mutations are not significant for the etiology of CH or else such mutations lie outside regions of the genome accessible by exome sequencing technology., (© 2014 S. Karger AG, Basel.)
- Published
- 2015
- Full Text
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31. Comparative validation of the radiographic and tomographic measurement of patellar height.
- Author
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Schueda MA, Astur DC, Arliani GG, Hornburg G, Serpa R, Neto WH, Kaleka CC, and Cohen M
- Abstract
Objective: To evaluate and validate the radiographic measurement of patellar height with computerized tomography scans., Methods: Measured the patellar height through the lateral radiographic image supported by one foot and sagittal tomographic view of the knee in extension, flexion of 20°, and quadriceps contraction of 40 patients (80 knees), asymptomatic and no history of knee injuries using Insall-Salvati index. There were 20 adult females and 20 adult males., Results: The height patellar index was higher in women of all images taken, in proportion. There was no statistical difference of patellar height index between the radiographics and tomographics images., Conclusion: The Insall-Salvati index in females was higher in all cases evaluated. Furthermore, it is possible to measure the patellar height index during tomographic study without distorting the results obtained, using to define the presence of patella alta or patella baja.
- Published
- 2013
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32. In vitro antifungal activity of the flavonoid baicalein against Candida species.
- Author
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Serpa R, França EJG, Furlaneto-Maia L, Andrade CGTJ, Diniz A, and Furlaneto MC
- Subjects
- Flavanones chemistry, Microbial Sensitivity Tests, Antifungal Agents pharmacology, Candida albicans drug effects, Candida tropicalis drug effects, Enzyme Inhibitors pharmacology, Flavanones pharmacology
- Abstract
The aim of the present study was to evaluate the in vitro activity of baicalein, the flavone constituent of Scutellaria baicalensis, and synergism of the combination of baicalein and fluconazole against Candida albicans, Candida tropicalis and Candida parapsilosis. The MIC(50) (lowest concentration at which there was 50 % inhibition of growth) of baicalein alone against six Candida strains ranged from 13 to 104 µg ml(-1). For the three species tested, exposure to baicalein at the MIC(50) concentrations obtained for each strain resulted in a high loss of viability. The fluconazole plus baicalein combination markedly reduced the MICs of both drugs for all three strains analysed. In addition, a synergistic effect between baicalein and fluconazole was observed for C. parapsilosis in terms of MIC(50) (fractional inhibitory concentration index = 0.207). Scanning electron microscopy analysis revealed that yeast cells exposed to baicalein at MIC(50) produced a profusely flocculent extracellular material, resembling a biofilm-like structure. In conclusion, these results showed the antifungal capability of baicalein against Candida species and highlight a promising role of baicalein when used in combination with fluconazole against Candida infections.
- Published
- 2012
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33. Ultrastructural architecture of colonies of different morphologies produced by phenotypic switching of a clinical strain of Candida tropicalis and biofilm formation by variant phenotypes.
- Author
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França EJ, Andrade CG, Furlaneto-Maia L, Serpa R, Oliveira MT, Quesada RM, and Furlaneto MC
- Subjects
- Candida albicans growth & development, Candida tropicalis growth & development, Cell Adhesion, Colony Count, Microbial, Microscopy, Electron, Scanning, Biofilms growth & development, Candida albicans ultrastructure, Candida tropicalis ultrastructure, Phenotype
- Abstract
Candida tropicalis has been identified as one of the most prevalent pathogenic yeast species of the Candida-non-albicans (CNA) group. Study of switching in C. tropicalis has not been the subject of extensive research. Therefore, we investigated switching event and characterized the ultrastructural architecture of different phenotypes and biofilm produced in a C. tropicalis clinical strain. Cells switched heritably, reversibly, and at a high frequency between four phenotypes readily distinguishable by the shape of colonies formed on agar at 25°C. SEM analysis was used to verify the architecture of whole Candida colonies at ultrastructural level. The smooth phenotype (parental phenotype) colony showed a hemispherical shape character, while the semi-smooth was characterized by the presence of shallow marginal depressions. The ring and rough phenotypes exhibited more complex architecture and were characterized by the presence of deep central and peripheral depressions areas. The biofilm-forming ability varied among the switch phenotypes. After 12h incubation, the smooth phenotype formed less biofilm compared to the other phenotypes (P<0.05). The electron microscopy analysis revealed that filamentation (pseudohyphae) was associated with ring and rough colonies. The ultrastructural analysis allowed the observation of the arrangement of individual cells within the colonies. At the deep central and peripheral depressions areas of the ring and rough colonies extracellular material was seen in different arrangements. The data presented here open new avenues to study a possible role for extracellular material in the formation and maintenance of the architecture of switch phenotypes in C. tropicalis. It is therefore essential that more strains be investigated to determine the biological significance of extracellular material in C. tropicalis phenotypic switching phenomenon., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2011
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34. Species distribution and in vitro fluconazole susceptibility of clinical Candida isolates in a Brazilian tertiary-care hospital over a 3-year period.
- Author
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Furlaneto MC, Rota JF, Quesada RM, Furlaneto-Maia L, Rodrigues R, Oda S, Oliveira MT, Serpa R, and França EJ
- Subjects
- Adult, Candida classification, Candida isolation & purification, Candidiasis microbiology, Cross Infection microbiology, Drug Resistance, Fungal, Female, Humans, Male, Microbial Sensitivity Tests, Middle Aged, Polymerase Chain Reaction, Species Specificity, Antifungal Agents pharmacology, Candida drug effects, Fluconazole pharmacology
- Abstract
Introduction: In this study, we aimed at identifying Candida isolates obtained from blood, urine, tracheal secretion, and nail/skin lesions from cases attended at the Hospital Universitário de Londrina over a 3-year period and at evaluating fluconazole susceptibilities of the isolates., Methods: Candida isolates were identified by polymerase chain reaction (PCR) using species-specific forward primers. The in vitro fluconazole susceptibility test was performed according to EUCAST-AFST reference procedure., Results: Isolates were obtained from urine (53.4%), blood cultures (19.2%), tracheal secretion (17.8%), and nail/skin lesions (9.6%). When urine samples were considered, prevalence was similar in women (45.5%) and in men (54.5%) and was high in the age group >61 years than that in younger ones. For blood samples, prevalence was high in neonates (35%) and advanced ages (22.5%). For nail and skin samples, prevalence was higher in women (71.4%) than in men (28.6%). Candida albicans was the most frequently isolated in the hospital, but Candida species other than C. albicans accounted for 64% of isolates, including predominantly Candida tropicalis (33.2%) and Candida parapsilosis (19.2%). The trend for non-albicans Candida as the predominant species was noted from all clinical specimens, except from urine samples. All Candida isolates were considered susceptible in vitro to fluconazole with the exception of isolates belonging to the intrinsically less-susceptible species C. glabrata., Conclusions: Non-albicans Candida species were more frequently isolated in the hospital. Fluconazole resistance was a rare finding in our study.
- Published
- 2011
- Full Text
- View/download PDF
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