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.
