جستجوی مقالات مرتبط با کلیدواژه « ژن Meca » در نشریات گروه « علوم پایه »

In this study, 50 Staphylococcus aureus samples from Baghdad Hospital were collected and examined, 17 samples were infected with methicillin-resistant Staphylococcus aureus (MRSA) and 5 samples were infected with vancomycin-resistant Staphylococcus aureus (VRSA). The sensitivity of the isolates against different antimicrobial agents was evaluated using the VITEK2 standard system. According to CLSI, the minimum inhibitory concentration (MIC) values of zinc oxide quantum dots (ZnO-QDs) were also tested by the Muller-Hinton dilution method. In addition, polymerase chain reaction (PCR) was performed to identify vanA and mecA genes. The antibacterial effects of ZnO-QDs on VRSA were higher than MRSA isolates.

Staphylococcus aureus is one of the most important pathogens in humans. The development of resistance to various antibiotics in this bacterium has become a global problem that due to the importance accessory gene regulator (agr) in this bacterium, which is responsible for coordinating and controlling the production and secretion of toxins and virulence factors. The purpose of this study was to investigate the pattern of antibiotic resistance and determine specific groups agr in order to find the dominant type of region in sensitive and methicillin-resistant Staphylococcus aureus.

Different clinical samples were prepared of Clients to Imam Reza Hospital in Bojnourd and phenotypic tests were performed on Staphylococcus aureus strains. Disc diffusion method was used to confirm drug sensitivity. DNA extraction was performed using a QiaAmp kit and Methicillin-resistant strains with mecA gene were identified by polymerase chain reaction (PCR) and agr groups were determined by multiplex PCR.

In this study, the highest antibiotic resistance of Staphylococcus aureus against cefoxitin was (75%). Isolates (73. %) have mecA gene and in sensitive and methicillin resistant strains the highest percentage belongs to agrI group with frequency of 60.71% and 15.58%.

Due to the fact that the pathogenicity of strains belonging to agr groups is different in various regions, it is necessary to determine the strains isolated from each region in order to find the dominant type in that region.

Staphylococcus aureus is a common cause of nosocomial infections and increased resistance to antimicrobial agents in this bacterium is one of the major problems in health care. We also see resistant strains of this bacterium that are important pathogens in the development of the disease. The control of these bacteria is very important from a health and economic point of view, so the aim of this study was to investigate the prevalence of methicillin mecA resistance gene and determine the pattern of antibiotic resistance in existing samples of Staphylococcus aureus and to evaluate the antibacterial activity of silver nanoparticles against Gram-positive Staphylococcus aureus.

In this cross-sectional study, 59 staphylococcus aureus specimens were collected from 11 nature detection laboratories. These samples were identified using standard laboratory methods and specific culture. PCR was used to evaluate the frequency of mecA gene. In order to use the antibiotic susceptibility pattern of the strains, the disk diffusion method is performed based on the CLSI protocol. Silver nanoparticles were made from ginger extract and Real Time PCR was used to evaluate the effect of silver nanoparticles on mecA gene expression.

Out of 59 samples of Staphylococcus aureus, 51 samples were resistant to methicillin. Phenotypic evaluation of antibiotic resistance pattern of methicillin-resistant Staphylococcus aureus strains showed that the results showed that 90% of isolates to penicillin, 85% to erythromycin, 84% to ceftriaxone, 53% to amikacin, 49% to gentamicin, 47% to piracyl 45% were resistant to spirofloxacin 37% to imipetmo 35% to linezolid, ie the highest antibiotic resistance was to penicillin 90%, erythromycin 85% and the lowest to imipetmo 37% and linzolid 35, respectively. Molecular analysis showed the presence of mecA gene in all samples. The results of real-time study showed that the effect of nanoparticles on mecA gene expression is significant.
Discussion and

The presence of 51 resistant samples out of 59 samples in the present study indicates an increase in resistance of methicillin-resistant Staphylococcus aureus to other antibiotics, which is a serious warning for the treatment of Staphylococcus aureus infections. And the effectiveness of silver nanoparticles on mecA gene expression shows that we can use this substance instead of existing antibiotics.