جستجوی مقالات مرتبط با کلیدواژه « ژن tst » در نشریات گروه « پزشکی »

The excessive use of Macrolide-Lincosamide-Streptogramin B (MLSB) to treat infections caused by Staphylococcus aureus (S. aureus,) the producer of toxic shock syndrome toxin-1 (TSST-1), can provide the basis for the emergence of resistant strains. The purpose of this study was to determine the pattern of antibiotic resistance to macrolides and tetracyclines and the genes involved in the occurrence of these resistance in S. aureus strains with TSST-1 toxin. In this descriptive cross-sectional study, 113 isolates of S. aureus were studied. Determination of pattern of resistance to macrolides and tetracyclines and different induction phenotypes was performed using disk diffusion method and D test. PCR was used to determine the presence of ermA, ermB, ermC, mphC and tsst gene. Of 113 isolates of S. aureus, 13 isolates (11.5%) were phenotypic D and 11 isolates (9.7%) were a phenotype R. Based on the resistance to clindamycin-erythromycin, 69 isolates (61.66%) were identified as S-phenotype. Tetracycline-resistant isolates (59.29%) had the highest frequency, and isolates resistant to minosilicon, dithromycin and tritromycin had the lowest abundance. In addition, 16 isolates (15.14%) were tst gene, 15 isolates (13.27%) were ermA gene, 6 isolates (5.3%) were ermB gene, 14 isolates (12.38%) were genes ermC and 1 isolate (0.88%) were also carriers of the aphC gene. There was a significant relationship between S. aureus MLSB strains and tst gene presence (p≥0.05). Induced resistance to clindamycin and tetracycline had a significant relationship with the presence of tsst gene in S. aureus strains producing TSST-1 toxin.

One of the most common infectious diseases in the world, is a respiratory infection that caused by attack of Staphylococcus aureus to the upper respiratory system. Due to the genomic diversity of species and toxins of Staphylococcus aureus strains and increasing antibiotic resistance of this bacterium, rapid detection of bacterium to reduce the transmission and spread of this pathogen in nosocomial infections is essential. The aim of this study was to survey the prevalence of tst gene and detection of antibiotic resistance pattern of Staphylococcus aureus isolates in respiratory system infection.
In this study 100 Staphylococcus aureus isolates from patients with respiratory infections were selected and the tst gene was proliferated with polymerase chain reaction and specific primers in this isolates were evaluated through gel electrophoresis. Study of the antibiotic resistance pattern of strains was done using the disk-diffusion method against 12 antibiotics, based on CLSI protocol.
In 14 of the 100 isolates studied, tst gene was identified. Most antibiotic resistance in this strains was oxacillin (100%) and the lowest antibiotic resistance was vancomycin (14.3%).
for producing different toxins in Staphylococcus aureus strains and the increasing antibiotic resistance of this bacterium, early diagnosis and appropriate treatment to prevent the progression of the disease caused by this bacterium is essential.

PCR reactions one of the most accurate and most sensitive tests for the molecular assays. DNA extraction always is time-consuming and costly before the PCR process, which in some cases removed can be saving time and Price. The aim of this study was to compare direct PCR and PCR with DNA extraction template for detection of tst, mecA and femA gens.
In this study, clinical isolates of Staphylococcus aureus were confirmed by biochemical tests. Then, with direct PCR by colony acquired of Muller Hinton agar culture and PCR with the extracted DNA extraction kit were studied for tst and mecA genes. For this test, three specific primers were used to target genes.
Findings: amplification was observed of tst, mecA and femA gens with length 326bp, 163bp and 132bp by direct PCR and PCR with the extracted DNA relevant to toxic shock syndrome toxin 1 and are resistant to methicillin. Finally, detected resistant strains and toxins strains by genes. Our results quantitatively Similar each other and in therm of qualitatively were different. The results of PCR test with using extraction kit obtained the better quality.
According to the results obtained in this study, to save time and cost in the detection of Staphylococcus aureus can be used to direct PCR. Bands quality obtained in this way to PCR, DNA, is acceptable and in some cases it can be used as a rapid diagnostic test. To make the better quality must be used mineral oils.