Showing 6 results for Doudi
Doudi M, Naghsh N, Heiedarpour A,
Volume 5, Issue 2 (Autumn – Winter 2011[PERSIAN] 2011)
Abstract
Abstract: Background and objectives: Antibiotic resistant to Antimicrobial agents is one of the most important concern in hospitals, which can lead to increased costs, treatment fails and mortality rates. The aim of this study was identification of Gram-negative bacilli resistant to extended-spectrum β-lactamase Enzymes (ESBLs) and determination of the effect of silver nanoparticles on them. Materials & Methods: of 276 clinical samples referred to three hospitals of Isfahan city, 186 gram negative bacilli were studied. To recognize ESBLs production, the bacilli was assessed by disk diffusion method and confirmed by DDT and Double Disk approximation Test. The ESBL producing bacteria were subjected to increasing concentrations (12.5, 25, 50,100,200,400 and 500 ppm) of silver nanoparticles, prepared in Tehran Nano Pars Company, and Inhibitory zone diameter was measured. Results: of 186 isolates, 140 (%75/3) are gram-negative bacilli producing ESBLs and 46 (24.7%) of them without this capability. Most of ESBLs bacteria are belonged to urine infections and the most prevalent bacterium is Klebsiella pneumonia. All samples are sensitive to the nano silver solution with density of 100 ppm. Enterobacter aerogenes (24 mm) and Pseudomonas aeruginosa (23mm) have the greatest Inhibitory zone diameter in the presence of 500 ppm of silver nanoparticles. Conclusion: It seems that silver nanoparticles have inhibitory effect on all studied gram negative bacilli. The inhibitory effect of silver nanoparticles against ESBL producing Gram negative bacteria is dose depended Keywords: Gram-negative bacilli, ESBLs, silver nanoparticles.
N Naghsh, M Doudi, Z Safaeinejad,
Volume 7, Issue 2 (summer[PERSIAN] 2013)
Abstract
Abstract
Background and objective: In recent years, the resistance of opportunistic fungal strains to commercially available antifungal agents has been increased. The serious side effects of these compounds on mammalian cells forced the researchers to search for new antifungal substances. Thus we decided to investigate the antifungal properties of silver nanoparticles against Aspergillusfumigatus.
Materials & Methods: To investigate the antifungal effect of the round silver nanoparticles with 10nm diameter against Aspergillusfumigatus, the diameter of colonies after 8 days as well as the number of colonies in different days was determined, using direct drop test. After that, to measure the Minimum Inhibitory Concentration (MIC) and Minimum Fungicide Concentration (MFC) values of silver nanoparticles and fluconazole, Micro Dilution Broth method was performed. At the end, the MIC and MFC values of silver nanoparticles were compared to MIC and MFC of fluconazole.
Results: The results obtained from direct drop test confirm that the silver nanoparticles can decrease the diameter of fungal colonies in dose dependent manner. The data of silver nanoparticles on the number of colonies in different days shows that the number of colonies increases up to sixth day and then becomes fixed. Based on the results of Micro Dilution Broth method, the MIC and the MFC values of this component are 31.25 and 62.5ppm, respectively.
Conclusion: The present study confirms that silver nanoparticles with 10nm diameter have antifungal activity against Aspergillus fumigates.
Key words: Silver nanoparticles, Aspergillusfumigatus, Antifungal activity.
N Naghsh, Z Nikbakht, M Doudi,
Volume 7, Issue 5 (supplement Issue( Bacteriology)[PERSIAN] 2014)
Abstract
Abstract
Background and Objective: the plants with the less side effects and drug resistance have been used worldwide. In this study, we compared the inhibitory effects of nanocopper and essential oil of Melissa officinalisL.a on E.coli and S.mutans in In Vitro condition.
Material and Methods: for studying diameter of inhibitory zone, disk agar diffusion method was used. Then, antibacterial effects of these substances were evaluated by treating them for 24 hours in Nanocopper particles (concentration of 100 and 500 ppm) and essential oil (12.5% to 100%), and analyzed by ANOVA.
Results: twenty-four hours after treatment, nanocopper had no inhibitory effect on these bacteria. However, the diameter of inhibitory zone for E.coli and S.mutans was 31.30±0.13mm and 16.30±0.13mm, respectively. There was not any synergistic effect between different concentrations of this plant and 500ppm of nanocopper after 24 hours of treatment on E.coli. But for S. Mutans, the diameter of inhibitory zone for mixture of 50% & 25% essential oil and 500ppm concentration of nanocupper was increased significantly compared to only essential oil (p=0.001,p=0.01).
Conclusion: based on the findings, nanocopper particles and essential oil of Melissa officinalis L.a have not any synergic effects on E.coli, but with some concentrations of this plant the reverse is true on S.mutans.
Keywords: Essential Oil of Melissa Officinalis, Nanocopper Particles, E.Coli, S.Mutans
Shima Kazemi , Monir Doudi , Gholm Reza Amiri ,
Volume 11, Issue 6 (Nov - Dec 2017)
Abstract
ABSTRACT
Background and Objectives: Development of ecofriendly processes for the synthesis of metal nanoparticles is of great importance in the field of nanotechnology. Microorganisms such as bacteria could be suitable candidates for bioproduction of nanoparticles due to their simplicity and high compatibility with the environment. The aim of this study was to use bacteria isolates from the effluent of wastewater treatment plants to produce silver nanoparticles.
Methods: For identifying silver-resistant microorganisms, we used the agar diffusion method using PHG II medium containing 0.5 mM silver to determine minimum inhibitory concentration. Bacterial identification was done with biochemical testing and polymerase chain reaction (colony PCR). Finally, silver nanoparticles were produced in the desired bacteria, and the properties of these nanoparticles were studied.
Results: We found five silver-resistant bacteria among which Stenotrophomonas maltophilia strain MS8 showed the highest resistance (MIC= 6 mM). The bacterium was able to synthesize silver nanoparticles in spherical shapes. The results obtained from visual observations using UV-VIS, TEM and XRD showed that the bacterium was able to reduce silver ions into silver nanoparticles with maximum size of 20 nm.
Conclusion: Based on our findings, this bacterium could be useful for biosynthesis of silver nanoparticles.
KEYWORDS: Bacteria, Biosynthesis, Minimum Inhibitory Concentration.
Maedeh Kiani Abri , Monir Doudi , Ali Mohammad Ahadi ,
Volume 12, Issue 3 (May-Jun 2018)
Abstract
ABSTRACT
Background and Objectives: Keratinase is an enzyme commonly used in the production of detergents, cosmetics, drugs, leather, and other industries. Considering the high cost of traditional methods for decomposition of feather, hair, hooves, nails, and wool that contain high levels of keratin, their biodegradation with keratinase-producing bacteria can be a valuable solution. The present study aimed for isolation and molecular identification of keratinase-producing bacteria in Qeshm Island and Peyposht village in Iran.
Methods: Water and sludge samples from the Qeshm Island and Peyposht village were collected. The bacteria isolates were screened for keratinase production using the Lowry method. Effect of pH and temperature was assessed on the production of keratinase and on the growth of the isolates. Colony-polymerase chain reaction was used for molecular identification of the isolates.
Results: Bacillus berevis and Enterobacter cloacae were isolated in this study. Keratinase production in B. berevis was highest at pH 7.5 and 35 °C. In addition, the highest level of enzyme production by E. cloacae was observed at pH 7 and 37 °C.
Conclusion: It seems that the bacterial strains isolated from sludge in the study area have relatively favorable keratinase production capacity.
Keywords: Bacteria, Colony PCR, Identification, Keratinolytic protein, Sewage.
Sona Rostampour Yasouri, Masoud Ghane, Monir Doudi, Abolhasan Rezaee, Nafiseh Sadat Naghavi,
Volume 14, Issue 6 (Nov-Dec 2020)
Abstract
Leptospirosis is a zoonotic disease with a high incidence rate in many parts of the world due to the presence of various hosts for the pathogenic Leptospira. Tropical, subtropical and humid regions are suitable for long-term survival of the bacterium. Because of the temperate and humid climate, northern areas of Iran are suitable for pathogenic Leptospira and outbreak of the disease. Therefore, identification of infected areas is important from a public health and economic point of view. Previous studies show that the incidence rate of leptospirosis is increasing every year. Therefore, accurate diagnosis, control and prevention of this disease seem necessary through vaccination and raising public awareness, especially among high-risk groups. Today, diagnostic methods including immunofluorescence assay, enzyme-linked immunosorbent assay, microscopic agglutination test (MAT) and polymerase chain reaction (PCR) are used to diagnose the leptospirosis. MAT is the gold standard test for the diagnosis of leptospirosis with extensive applications in Iran. Due to the importance of this disease and its high prevalence in recent years, the present study aimed to investigate the epidemiology and diagnosis of leptospirosis in Iran.
