Showing 5 results for Inhibitory
Jabal Amely F, Malek Zadeh F,
Volume 61, Issue 1 (4-2003)
Abstract
In Vivo, after administration of treatment, concentrations of antimicrobial agents will reduce to sub-inhibitory levels (sub-MIC) and may therefore affect the properties of target bacteria. The purpose of the present study was to investigate the in vitro effect of sub-minimum inhibitory concentrations (sub-MIC) of ampicillin, gentamicin and nalidixin acid on morphology, growth, ammonium production and urease activity of proteus mirabilis. Proteus mirabilis is well recognized as an important urinary tract pathogen.
Materials and Methods: Several of its properties have been studied in relation to pathogenesis manifested in urinary tract such as urease activity.
Results: In the presence of ampicillin, long filamenteous cells was produced and the length of the cells was increased at the higher concentration of ampicillin. Sub-MIC of ampicillin and gentamicin affected the growth pattern and prolonged the lag-phase of growth. This affected was significant when gentamicin was used. Nalidixic
acid of 1/2 MIC greatly reduced the growth rate, while the lag phase was not
changed. In the presence of sub-MICs of ampicillin and gentamicin, the amount of
ammonium production increased. In medium with 1/2 MIC of ampicillin, the
ammonium production was 30 times of control, while the urease specific activity of sonicated cells did not show any significant changes.
Conclusion: It seemed that the antibiotics enhanced the cell membrane permeability for substrate and enzyme. Nalidixic acid didn't show any significant effect on ammonia production, and urease specific activity of proteus mirabilis. The results indicate that the sub-MIC of antibiotics can effect virulence factors of proteus mirabilis.
Saki Gh, Sobhani A, Akbari M,
Volume 63, Issue 4 (7-2005)
Abstract
Background: This study was performed to investigate the rate of inner cell mass of blastocyst which obtain from culture of mouse two cell embryos in presence and absence of recombinant of human leukemia inhibitory factor.
Materials and Methods: ICR female mice that were between 6-8 weeks old received intra peritoneal injection of 7.5 IU of pregnant mare serum gonadotropine for super ovulation, this was followed by intra peritoneal administration of 7.5 of hCG 46-48 hours later. The mice were then mated to mature ICR male mice and were checked for vaginal plug 20 hours later. Female mice were killed by cervical dislocation 48-50 hours after hCG administration and after washing and flushing of the oviduct from the proximal end of the oviduct, two cell embryos were selected and collected by 100 microscopy. All two cell embryos were randomly divided in 4 groups (Groups A, B C and D) and culture in special media. Groups A: KSOM+AA, Groups B: KSOM+AA 500 IU/ml LIF. Groups C: KSOM+AA 1000 IU/ml LIF. Groups D: KSOM+AA 1500 IU/ml LIF media until 120 hours in Co2 incubator .After that time all blastocysts collected and the number of ICM was assessed by differential staining technology.
Results: The rates of ICM of blastocysts which obtain from groups A, B, C and D were 19 2.6, 28 4.4, 24 2.1, 26 2.2 respectively. This data indicated that the rate of ICM in groups B, C and D was statistically higher than group A (P=0.02) and also there was not statistically different between three groups of B, C and D.
Conclusion: Briefly leukemia inhibitory factor can improve the rate of ICM of blastocyst and we suggest that this factor is better added to blastocyst culture medium.
Diba K, Mousavi B, Mahmoudi M, Hashemi J,
Volume 68, Issue 2 (5-2010)
Abstract
Background: Several studies have shown that propolis has antibacterial, antifungal,antiviral and antiparasitic activity. Furthermore propolis has been described to have medicinal usages in some fungal infections like Candidiasis. Our aim is to study the inhibitory effects of alcoholic extract of propolis on Candida spp. and Aspergillus spp.Methods: To determine inhibitory and fatality dose of propolis extract, we prepared serial dilution of the extract including 1/20, 1/40, 1/80, 1/160, 1/320 and 1/640 in 1 ml of liquid medium sabouraud broth. Given numbers of Candida yeasts in 1ml were added to above dilution tubes. Candida and Aspergillus cultures were incubated at 30°C and 25°C respectively for 24-72 hours.Results: We obseved that the concentration of 0.25 g/dl of propolis extract showed an
inhibitory and killing effect on more than 50% of the isolates. But there were no inhibitory and killing by the concentrations 0.0312 g/dl and 0.0625 g/dl on Candida
isolates. Our findings showed that 0.0312 g/dl of the extract was partially active on Aspergillus fumigatus and dilution of 0.125 g/dl was active on Aspergillus. niger. In the agar dilution method, some changes were observed on morphological features (depends on the extract dilution) as well as quantitative effects of dilution of extract on the colonies.Conclusion: We found that the alcoholic extract of propolis had a prominent antifungal activity and inhibitory effect on Candida and Aspergillus isolates.
Hashemi Sj, Zaini F, Daie R, Zibafar E, Zakeri Ma,
Volume 69, Issue 2 (5-2011)
Abstract
Background: Different studies have shown that despite the expanding number of antifungal agents, death rate caused by Aspergillus species has been increased during the recent decades due to drug-resistance occurrence, increased minimum inhibitory concentration (MIC) and cross-resistance among the isolated species. Regarding the lack of effective response to conventional treatments and antifungal susceptibility patterns of the most common isolated Aspergillus species, this study was undertaken to draw a clearer picture in the Iranian setting.
Methods: During 13 months from September 2009 to October 2010, 50 clinically isolated Aspergillus cases were identified based on the method described by Klich (2002) and their morphological features. Subsequently, their susceptibility test was carried out according to NCCLS- M38A broth microdilution method.
Results: We found that 7.5% of the isolated A. flavus with an MIC>2 µg/ml to amphotericin B were probably clinically resistant types, and 25% of them with an
MIC<8 µg/ml to itraconazole were less sensitive isolated species. The isolates were less
sensitive to voriconazole too. The MIC range of 9 strains of A. niger and the MIC of one strain of A. fumigatus had increased to all the three medications in comparison with similar foreign studies.
Conclusion: In this study we found that the MICs of most isolates were in the range of the reference strains and the MICs of some isolates were in the range of similar foreign studies. In some significant cases, the MICs were beyond the known ranges showing the lower sensitivity of Iranian isolates and their increased MIC patterns.
Mohammadreza Aflatoonian , Mehrdad Khatami , Iraj Sharifi , Shahram Pourseyedi , Mansour Khatami , Hajar Yaghobi , Mahin Naderifar ,
Volume 75, Issue 8 (11-2017)
Abstract
Background: Nanoparticles are particles that have at least one dimension between 1 and 100 nanometers. Nanoparticles are a new generation of antimicrobial agents. Nanoparticles with antimicrobial activity, especially as a new class of biomedical materials for use in increasing the level of public health in daily life have emerged. Zinc oxide nanoparticles have attracted a great attention due to the variety of their applications in medical science. The aim of this study was to evaluate and compare the antimicrobial activity of zinc oxide nanoparticles synthesized by green method.
Methods: This experimental study was done in 2017, from March to September in the Bam Research Center of University of Medical Sciences Kerman, Iran. Green synthesis of zinc oxide nanoparticles was investigated using cumin seeds. The physicochemical characteristics of synthesized nanoparticles were studied by UV-visible ultraviolet spectrometer (Analytik Jena AG, Germany), X-ray diffraction and transmission electron microscope (TEM) (Carl Zeiss, Germany). Broth microdilution method was used to investigate the antimicrobial activity of zinc oxide nanoparticles. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of these nanoparticles were determined for Pseudomonas aerogenes and Enterococcus faecalis strains.
Results: The UV-visible ultraviolet spectroscopy showed an absorption peak in the range of 370 nm. Transmission electron microscopy shows the synthesis of zinc oxide nanoparticles, mostly spherical, with a size less than 50 nm. Minimum inhibitory concentration of zinc oxide nanoparticles against P. aerogenes and E. faecalis strains was determined at 6.25 and 12.5 μg/ml, respectively. Both bacteria were sensitive to zinc oxide nanoparticles. This sensitivity was higher for gram-negative bacteria.
Conclusion: Zinc oxide nanoparticles were produced using Iranian natural resources and our results showed significant antibacterial activity. Nanotechnology creates materials with novel properties every day, and creates new hope for improving environmental pollution. These nanoparticles can be used as a new generation of antimicrobial agents in various medical disciplines. For example, toothpaste containing zinc nanoparticles can be produced and prescribed for patients with immune deficiency to prevent the growth of microbial pathogens in the mouth and its transmission to the patient's body.
