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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Iranian Journal of Biotechnology
- نوع مقاله: Journal Article
- کلمات کلیدی: Aflatoxin B1,FRET,Magnetic/Silica Core shell,Nanobiosensor
- چکیده:
- چکیده انگلیسی: Background: Recently, some new nanobiosensors using different nanoparticles or microarray systems for detection of mycotoxins have been designed . However, rapid, sensitive and early detection of aflatoxicosis would be very helpful to distinguish high-risk persons. Objectives: We report a highly sensitive competitive immunoassay using magnetic/silica core shell as a signal intensifier for the determination of aflatoxin B1 using fluorescence resonance energy transfer (FRET) from Cd/Te quantum dots (anti-aflatoxin B1 antibody immobilized on the surface of Cd/Te quantum dots) to Rhodamine 123 (Rho 123-labeled aflatoxin B1 bound to albumin). The specific immune-reaction between the anti-aflatoxin B1 antibody on the QDs and the labeled-aflatoxin B1 brings the Rho 123 fluorophore (acting as the acceptor) and the QDs (acting as the donor) in close spatial proximity and causes FRET to occur upon photo-excitation of the QDs. Using magnetic/silica core shell to intensify the obtained signal is the novelty of this study. Materials and Methods: Cd/Te QDs were synthesized by the simultaneous reduction of cadmium chloride and tellurium in the presence of sodium borohydride under nitrogen atmosphere. Magnetic nanoparticles were synthesized using FeSO4 and FeCl3 (1:2 molar ratio) and ammonia as an oxidizing agent under nitrogen atmosphere. The prepared magnetic nanoparticles shelled by silica using tetraethoxysilane in the presence of ammonia. Nanoparticles synthesis and monodispersity confirmed by TEM. Immobilization of Cd/Te QDs to antibodies and labeling of aflatoxin B1-albumin by Rho 123 were performed by EDC/NHS reaction in reaction mixture buffer, pH 6, at room temperature. Results: By using the magnetic/silica core shell sensitivity of the system changed from 2×10-11 in our previous study to 2×10-12 in this work. The feasibility of the method established by the detection of aflatoxin B1 in spiked human serum. There is a linear relationship between the decreased fluorescence intensity of Rho 123 with increasing concentration of aflatoxin B1 in spiked samples, over the range of 0.01-0.06 mmol.mL-1. Conclusion: This homogeneous competitive detection scheme is simple, rapid and efficient, and does not require multiple separation steps and excessive washing.
- انتشار مقاله: 03-12-1393
- نویسندگان: Alireza Kalarestaghi,Mansour Bayat,Seyed Jamal Hashemi,Vadood Razavilar
- مشاهده
- جایگاه : پژوهشی
- مجله: Current Medical Mycology
- نوع مقاله: Journal Article
- کلمات کلیدی: Kombucha,Aspergillus fumigatus,CgrA gene,Cyp51A gene
- چکیده:
- چکیده انگلیسی: Background and Purpose: Aspergillus fumigatus is one of the most common opportunistic fungus, which causes infection in immunocompromised and neutropenic patients. The current guidelines recommend voriconazole as the initial therapeutic and prophylactic agent for almost all cases, especially in patients with organ transplants, which leads to increased medication resistance in A. fumigatus. The aim of the present study was to evaluate the antifungal activity and effect of kombucha as a natural compound on A. fumigatus growth, as well as on the expression of cgrA and cyp51A genes.
Materials and Methods: A panel of 15 A. fumigatus strains with two quality controls of CM237 and CM2627 as susceptible and resistant strains were obtained from Tehran Medical Mycology Laboratory, Tehran,Iran(TMML).Antifungal susceptibility testing assay was performed according to the Clinical and Laboratory Standards Institute (CLSI) M38-A2 document. Moreover, the mycelial dry weight of the fungus was calculated before and after being treated with kombucha. In addition, the quantitative changes in the expression of cgrA and cyp51A genes were analyzed by real-time polymerase chain reaction (real-time PCR) technique.
Results: In the present study, the minimum inhibitory concentration ranges of kombucha were measured at 6,170 and 12,300 μg/mL for ten A. fumigatus azole-susceptible strains and 24,700 μg/mL for five A. fumigatus resistant strains. Moreover, changes in mycelial dry weight under kombucha treatment conditions underwent a significant reduction (P≤0.05). A coordinate down-regulation of expression in cgrA and cyp51A genes was observed in all azole-susceptible and -resistant A. fumigatus strains, after treating the fungus with different concentrations of kombucha (P≤0.05).
Conclusion: According to the obtained results, kombucha as a natural antioxidant , can exert inhibitory effects against the growth and expression of some genes in A. fumigatusstrains.- انتشار مقاله: 11-03-1398
- نویسندگان: Ladan Nazemi,Seyed Jamal Hashemi,Roshanak Daie Ghazvini,Mina Saeedi,Sadegh Khodavaisy,Aleksandra Barac,Mona Modiri,Maryam Akbari Dana,Zahra Zare Shahrabadi Zare Shahrabadi,Sassan Rezaie
- مشاهده
- جایگاه : پژوهشی
- مجله: Current Medical Mycology
- نوع مقاله: Journal Article
- کلمات کلیدی: Pesticides,Aspergillus flavus,Gene expression,Azole resistant
- چکیده:
- چکیده انگلیسی: Background and Purpose: Aspergillus flavus is an important pathogen in immunodeficient patients. Due to the abundance of this fungus in nature, fungicides are commonly used to preserve and maintain agricultural products. Long-term exposure to these pesticides can lead to the induction of drug resistance in this fungus.
Materials and Methods: For the purpose of the study, 10 strains of A. flavus ATCC 204304 were cultured in benomyl and diazinon pesticides at the concentrations of 62.5, 125, 250.500, 750, 1000, 1500, 2000, and 2500 mg/L in nine steps. Morphological changes and resistance to voriconazole, itraconazole, and amphotericin B were evaluated at the end of each step. Subsequently, changes in the expression of mdr1 and cyp51C genes were studied in the strains showing drug resistance.
Results: The results showed that during the nine stages of the adjacency of strains with benomyl and diazinon at different concentrations, resistance to voriconazole, itraconazole, and amphotericin B in these toxins increased by 30% and 10%, respectively. In addition, the microscopic examination of resistant strains revealed the absence of sporulation, and only mycelium was found. Macroscopically, the color of the colonies changed from green to white. Furthermore, the investigation of the expression of mdr1 and cyp51c genes in these strains showed a decrease and increase in adjacency with diazinon and benomyl, respectively.
Conclusion: As the findings indicated, exposure to agricultural pesticides can lead to the incidence of morphological changes and resistance to amphotericin B, itraconazole, and voriconazole in the sensitive species of A. flavus by altering the expression of genes involved in drug resistance.- انتشار مقاله: 18-04-1398
- نویسندگان: Maryam Akbari Dana,Seyed Jamal Hashemi,Roshanak Daei Ghazvini,Sadegh Khodavesi,Mona Modiri,Ladan Nazemi,Sima Darabian,Sasan Rezaie
- مشاهده
- جایگاه : پژوهشی
- مجله: Current Medical Mycology
- نوع مقاله: Journal Article
- کلمات کلیدی: Antifungal susceptibility,Econazole,Superficial candidiasis
- چکیده:
- چکیده انگلیسی: Background and Purpose: Candida species are the most common organisms involved in superficial fungal infections, worldwide. Although econazole is among the most frequently used topical formulations for the treatment of candidiasis, no information is available regarding the susceptibility profiles of Candida species in Iran.
Materials and Methods: In vitro susceptibility of 100 clinical Candida isolates belonging to 6 species from superficial candidiasis of Iran towards to econazole was compared with three other common antifungal agents including itraconazole, fluconazole, and miconazole. Minimum inhibitory concentrations (MICs) values were analyzed according to the Clinical and Laboratory Standards Institute (CLSI) M38-A3 document. All isolates were previously identified to the species level, using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) on ITS region.
Results: The MIC of econazole, itraconazole, miconazole, and fluconazole were within the range of 0.016-16, 0.032-16, 0.016-16, and 0.25-64 g/ml, respectively. In general, econazole and miconazole were more active against Candida isolates, compared to the other two agents.
Conclusion: The present study demonstrated that for Candida albicans isolates, miconazole and econazole had the best effect, but in non-albicans Candida species, itraconazole and miconazole displayed more activity than other antifungal agents.- انتشار مقاله: 18-04-1398
- نویسندگان: Mahdi Abastabar,Tahereh Shokohi,Reyhaneh Rouhi Kord,Hamid Badali,Seyed Jamal Hashemi,Zeinab Ghasemi,Aynaz Ghojoghi,Nesa Baghi,Maryam Abdollahi,Susan Hosseinpoor
- مشاهده