RESUMO
BACKGROUND: The main problem in treatment of leukemia patients is the chemotherapy resistance which is a main concern in recent years. The cause of chemotherapy drug resistance is related to MDR gene which is located on chromosome 7 (7q21-31) and it is mainly connected with energy-dependent efflux (P-glycoprotein). This study was conducted to assess the correlation between MDR polymorphism and chemotherapy efficiency with Vincristine in a sample of Iraqi Acute Myeloid Leukemia (AML) patients. METHODS: The blood sample of 200 AML patients and 200 controls were collected and the frequency of rs2032582 was calculated through sequencing and then the role of different genetic patterns was evaluated on cancer cells by MTT assay. RESULTS: The results indicate that GG and TT genotypes (20 and 20.5% from total patients count) are more frequent in Iraqi AML patients than other genetic patterns in MDR gene and also the genotype TA is more sensitive to Vincristine chemotherapy than other genotypes. CONCLUSION: It seems that genetic pattern is the main factor in determination of chemotherapy of AML patients, and patients should not undergo chemotherapy with such drugs, especially Vincristine.
RESUMO
BACKGROUND AND OBJECTIVES: Staphylococcus aureus is an opportunistic human pathogen that causes a variety of diseases. Staphylococcal biofilms are a source of chronic and continual infections. This study was conducted to estimate the distribution of agr among different isolates of S. aureus and their relationship with biofilm. Also, it was aimed to check the association of operon agr with virulence factors (seb, eta, spa and tst v8) and study the effect of biosynthesis silver nanoparticles on the function of the agr system. MATERIALS AND METHODS: Out of 580 clinical specimens, 100 S. aureus isolates were isolated and identified based on cultural, morphological, and different biochemical tests, in addition to molecular identification using PCR with specific primer 16SrRNA. For biofilm detection, the fungi synthesized silver nanoparticles were used to check its effect on agr system. RESULTS: The biofilm producer among S. aureus was 61% and non-biofilm producer isolates were 39%. It was found that the total number of agr - bearing isolates was 31 (50.82%), with a significant difference in the distribution percentage of virulence factors genes in isolates of biofilm-forming S. aureus carried agr. The results also revealed a relationship between the agr-quorum sensing system and the prevalence of virulence genes in the isolated S. aureus. Silver nanoparticles (AgNPs) were synthesized by Agaricus compestris, and it was found that it activates the agr system in 31 (100%) of biofilm-forming and carrying operon agr after treatment with sub-MIC of AgNPs. CONCLUSION: The findings of this study revealed that not all isolates of S. aureus have agr system. Also, it was found that AgNPs have a positive effect on bacterial virulence factors production and could be used for treatment or in cooperation with antibiotics to decrease resistance.
