جستجوی مقالات مرتبط با کلیدواژه "انتشار دیسک" در نشریات گروه "پزشکی"

Medicinal plants are some of the most important sources of medicine in several countries. Urinary tract infection is one of the most common infections and blood infection is an important cause of death worldwide. Antibiotic resistance has increased as a fundamentally global problem that needs appropriate alternatives. Fumaria parviflora Lam, Myrtus communis L., Matricaria recutita L. and Nigella sativa L. are some of the most important plants in traditional medicine.

First, plants were powdered using electric grinder and then the hydroalcoholic extract was prepared using maceration method. After dispersing alcohol, this was lyophilized and three concentrations of 64, 160, and 220 mg/ml were prepared. Antimicrobial effects were assessed using disk diffusion method and antioxidants were investigated using DPPH method.

The highest percentage of inhibition for the Myrtus was against Escherichia coli bacteria (86%) and Pseudomonas aeruginosa (100%) compared to gentamicin and 100% resistance was observed for Staphylococcus aureus compared to erythromycin. Nigella sativa included the highest antioxidant effect (nearly 60%) and Myrtus with 43% had the lowest antioxidant effect. Using Gas chromatography-mass spectrometry, it was detected that the most effective substances in Myrtus, Nigella sativa, Fumaria parviflora and Matricaria respectively were benzotriol (30.97%), octadecadienoic acid (44.35%), pyran (13.26%) and benzopyran (50.24%).

Myrtus plant includes the most antimicrobial effects and Nigella sativa includes the most antioxidant effects.

Denture stomatitis is the most common opportunistic infection caused by candida in denture wearer’s palate, which is more common and severe among diabetic patients. Several studies have already been conducted to examine various drugs for treatment of candidiasis. Recently, some cases of drug resistance of none albicans Candida species to antifungal drugs have been reported. The aim of the present study was to compare the in vitro susceptibility of isolated Candida species of uncontrolled diabetic patients against Nystatin and Fluconazole.

In the present lab trial study, 43 patients with uncontrolled diabetes mellitus and denture stomatitis referred to Yazd Diabetes Research Center and Clinics were screened and sample were collected from the palate using sterile swabs. At that point samples were cultured to determine the differential colony counts through the color difference between the colonies and furthermore MIC of Nystatin and Fluconazole by two different methods (Broth microdilution &Disk diffusion). Data were analyzed using SPSS23 and Kruskal-Wallis test.

In the present study, the most commonly isolated species were: Candida albicans (38/3%), followed by Candida tropicalis (14/9%), Candida krusei (10/6%), Candida glabrata (8/5%) and other species (27/7%). According to both methods, Candida albicans was the most sensitive to both Nystatin and Fluconazole. The most resistant species to Nystatin and Fluconazole were Candida glabrata and Candida Krusei respectively. In 100% concentration, sensitivity of candida species to Nystatin was significantly higher than Fluconazole, except for Candida albicans (p-value=0/05).

The present study indicated that Nystatin was better than Fluconazole for treatment of denture stomatitis in uncontrolled diabetic patients.

 Peppermint is one of the valuable medicinal plants with strong anti-microbial and anti-oxidant properties, which has various applications in the food industry.

 Fresh peppermint leaves were processed as a single layer by different drying methods (solar, sun and shade). Then, the effect of different drying methods on the quality and quantity of essential oil compounds was evaluated by GC-MS. Also, the antibacterial efficiency of the noted essential oil against Staphylococcus aureus bacteria was studied by disk diffusion method.

 The results showed that the most important chemical compounds in peppermint essential oil include menthone, menthol, isomenthol, mentofuran, polygon and piperitone. The highest amount of bacterial inhibition zone (IZ) was observed in the case of essential oil extracted from peppermint leaves dried by solar method (IZ=55 mm).

In general, the drying method is one of the main stages of medicinal plants processing, which has a significant effect on the bioactive compounds (extracts and essential oils) of medicinal plants. Therefore, it is necessary to use the suitable drying method.

The accumulation of airborne bioaerosols on filtration media and their gradual proliferation in the presence of appropriate moisture and environmental conditions is one of the major problems against using these media.The use of hybrid media containing antibacterial agents is one of the available solutions to this problem. The present study was aimed to fabricate nonwoven nanofiber media with antibacterial activity using electrospinning process.

Polyurethane-chitosan nanofiber media with weight ratios of 100 to 0, 90 to 10, 80 to 20, and 70 to 30 were fabricated by simultaneous electrospinning process. After preparation of the nanofiber media, their antibacterial properties were evaluated by standard methods of disk diffusion (ISO 20645) and colony counting (ISO 20743).

The bacterial growth inhibition zones gradually are formed around the examined samples by adding the layers of chitosan nanofibers to the polyurethane media indicating the antibacterial activity of these substrates. The evaluation of antibacterial activity of samples by both methods showed that the media with polyurethane to chitosan weight ratio of 70 to 30 had suitable antibacterial activity. The mean value of bacterial growth inhibition zone and antibacterial activity for polyurethane-chitosan (70/30) media were 0.226 mm and 2.222, respectively.

Evaluating the antibacterial activity of prepared nanofiber media indicated that antibacterial nanofiber media can be created by adding chitosan nanofibers as antimicrobial agents to the polyurethane nanofiber.

In this study, the effect of Myrtus extracts on 25 methicillin resistant Staphylococcus aureus (MRSA) and Escherichia coli ESBL strains isolated from patients were compared by two methods.

15 methicillin-resistant Staphylococcus aureus (MRSA) and 10 Escherichia coli ESBL isolates were used in this study. Fresh Leaves of Myrtus were collected from the herbal medicine farm. Extraction was performed using a reflux distillation. The effect of concentrations 0.195-100 micrograms per ml of Myrtus extract on clinical isolates was analyzed in disk diffusion method compared with micro broth dilution method and with MTT in 545 nm on an ELISA reader apparatus.
Findings: Inhibition zone diameter for the minimum effective concentration of 50 micrograms per milliliter in all isolates of ESBL and MRSA were as 8±1 mm and 11±1. Minimum Inhibitory Concentration (MIC) was 6.25mic/ml and Minimum Bactericidal Concentration (MBC) was determined 12.5mic/ml for E. coli ESBL. Furthermore, the amounts for MIC and MBC was determined as 12.5 and 25 mic/ml, respectively for Staphylococcus aureus.

The results of this study showed compliance of two methods in evaluation of drug-resistant clinical isolates. It was proved that the disk diffusion method could be determining range of effective concentration but micro broth method determines the effective concentration carefully. It is recommended that results obtained from disk diffusion not to be basis for final decisions in traditional medicine studies. Bacterial behavior in the broth and determination of the point of death greatly increases the accuracy of the results.

Using active antimicrobial packaging reduce the risks of growth of pathogenic or spoilage microorganisms in foods. In this study, antimicrobial activity of poly lactic acid (PLA) films containing different concentrations (0, 0.5, 1 and 1.5%) of Trachyspermum ammi essential oil and ethanolic extract of propolis (0, 1 and 2%) was evaluated against Listeria monocytogenes, Staphylococcus aureus, Escherichia coli O157:H7 and vibrio parahaemolyticus by using disk diffusion assay.
Circular discs of poly lactic acid films incorporated by essential oil and ethanolic extract of propolis, prepared by casting method on glass petri dishes, were placed on Muller-Hinton agar plates that previously inoculated by tested bacteria. Diameters of inhibition zones were measured after 24 h incubation of plates at 35o C, by using Digital Caliper and Digimizer software.
Result of this study showed that the inhibition zone was increased with increasing concentration of essential oil for all tested bacteria. Also, gram positive bacteria were more sensitive to the poly lactic acid films containing essential oil than gram negative bacteria. The results revealed that L. monocytogenes was the most sensitive bacteria against films containing Trachyspermum ammi essential oil alone or in combination by ethanolic extract of propolis. Also, poly lactic acid films containing ethanolic extract of propolis showed no inhibitory effects against all tested bacteria.
Poly lactic acid films containing Trachyspermum ammi essential oil have a high potential for antimicrobial food packaging applications to enhance the safety of food products.

Resistance of Staphylococcus aureus to antibiotics is one of the major global health problems in human societies. Thus, evaluation of pattern of antibiotic resistance in its different strains is very important. This study was carried out to evaluate the antibiotic resistance in Staphylococcus aureus isolated from clinical samples by disk diffusion and PCR methods.
In this laboratory- descriptive study, 50 isolates of Staphylococcus aureus to be identified from clinical specimens. Methicillin resistance was examined using PCR and antibiotic susceptibility of isolates was tested by disk diffusion method.
50 isolates were resistant to methicillin, ampicillin and penicillin. The resistance of isolates to erythromycin, Gentamicin, Clindamycin and Ciprofloxacin were 48%, 34%, 34%, 34%, respectively. The PCR method showed that 98% of Methicillin Resistance of Staphylococcus aureus isolates carried the methicillin resistant gene.
This study indicated that 98% isolates harbor mecA genes and more resistant to methicillin related mecA genes.

Coetaneous leishmaniasis is a protozoan infection which is caused by different species belonging to the genous Leishmania. Cutaneous leishmania have mostly wet and secretory sores so they create suitable environment for the growth of bacteria، fungi and other microorganisms، which results in secondary infections. In this study glucose oxidase has been used for the treatment of the bacterial strains isolated from coetaneous leishmaniasis sores. Isolated bacteria were Pseudomonas aeruginosa، Escherichia coli، Proteus vulgaris، Staphylococcus epidermidis and Corynebacterium xerosis. This loboratory study was performed on secondary bacterial infections of coetaneous leishmaniasis of 50 patients admitted to Sedighe Tahere hospital- Isfahan. In this research various dilution of glucose oxidase 10Ku/ml (0. 5، 0. 25، 0. 125، 0. 062، 0. 031، 0. 015، 0. 007، 0. 003، 0. 001) were used for assessing antibacterial effects by Minimum Inhibitory Concentration (MIC) and agar disk diffusion methods. Based on the results، isolated bacteria from the sores (Escherichia coli، Proteus vulgaris، Pseudomonas aeruginosa، Staphylococcus epidermidis and Corynebacterium xerosis) showed great sensitivity to the glucose oxidase at various dilutions. Glucose oxidase، had inhibitory activity against the gram-positive and the gram-negative bacteria، thus this enzyme can be used for the treatment of the bacterial secondary infections of the sores of leishmaniasis.

As a result of indiscrimate use of antimicrobial drugs in the treatment of infectious diseases, microorganisms especially gram negative bacteria, have developed resisrtance to many antibiotics and there is a need to develop antimicrobial drugs.One approach is use of local medicinal plants which represent a rich source of novel antimicrobial agents. Due to rapid increase of antibiotics resistance, fewer side effects of chemical drugs, antibacterial properties of oaks and other reasons, this study was carried out. In this experimental study the antibacterial activity of methanolic extract of oak bark,fruit hull,fruit and leaves was evaluated and compared with some in-use antibiotics.Milled oak sample was extracted with methanol in Soxhleťs apparatus. Extracts in three concentration(25,50,75mg/ml) were tested using agar diffusion method on Escherichia coli. Results showed that the effect of the extracts on E.coli was concentration-dependent. also antibacterial effect of fruit was better than leaf, bark, fruit hull and tested antibiotics. antibacterial effect of leaf, bark and fruit hull was similar together and often lesser than antibiotics. This results suggest that Quercus persica possesses compounds with antibacterial properties. Probably this antibacterial activity is due to presence of tannins in the plant extract. Because Tannin is one of the major components of Q.persica with contractive,disinfective,antimicrobial and... effects. Importance of oak trees is most due to presence of tannins in their different partes.

Sea cucumber is a traditional food and medical item and has been reported to exhibit Antioxidant, antifungal, anti tumoral and antibacterial bioactivity. The objective of this study is to describe the antibacterial activity of 4 extracts of Holoturia. Sp (sea cucumber), collected from Hengam Island of Persian Gulf. Methanol, hexane, aqueous and chloroform extracts from body wall tissue of the sea cucumber were screened for antibacterial activity against three strains of Escherichia coli Top 10 F´, TG1 and K12 using disc diffusion and broth microdilution tests methods. The growth of all these strains were inhibited using concentration from 0.78 to 100 mg/ml of methanol, hexan and chloroform extracts. Among the extracts just methanol and chloroform with 100 mg/ml had bactericidal effect on TG1 and K12 strains. On the other hand, Aqueous extract had induced growth in of the all strains. The results suggest the possibility of applying sea cucumber as source of potential anti bacterial agents, whose compounds can be good candidates to make antibiotic products.

Background and -Helicobacter pylori is a gram negative spiral bacilus which infects gastric mucosa and causes a wide range of gastro intestinal diseases.Unfortunately the prevalence of the infection by this organism in developing countries is high and despite numerous existing drug regimens, treatment fails to eradicate the organism in many occasions. To reach an effective and curative regimen, invitro determination of suscepibility and resistance of the organism, to various antimicrobials, is pradent. The goal of this study was to determine the prevalence of antimicrobial resistance in Helicobacter pylori,s isolated from cultures. Biopsies from 67 patients admitted to the Sari Imam Hospital were used to cultur Helicobacter pylori and determine their susceptibility and resistance to metronidazole, claritromycin and amoxycillin. Disc diffusion tecniqu was used to determine the minimum inhibitory concentration, (MIC) and resistance pattern of the isolated Helicobacter pylori.In this method we used the cutoff point of MIC 90 ie, a concentration at which 90% or more of culture plates show inhibition zone around the antimicrobial test disc. MIC 90 for amoxycillin and claritramycin in our study was 0.25 g/ml and all isolates were susceptible to amoxycillin. Only one isolate was resistant to claritramycin. MIC 90 for metronidzole was 16 and 4 resistant cases were isolated. This stndy showed low level of resistance to metronidazole and claritramycin which were comparable to the reported results from other studies. No resistance was observed to amoxycillin which was also the same as other reported results. According to the pattern of antimicrobial resistance, we can recommend the studied drugs, against Helicobacter pylori.