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Showing 3 results for Farnia
Parisa Tahmasebi, Fatemeh Maryam Sheikolslami , Parisa Farnia , Majid Sadeghizadeh, Rashid Ramazanzadeh, Mahdi Kazempoor, Mohammadreza Masjedi , Ali Akbar Velayati,
Volume 11, Issue 4 (winter 2011)
Background & objectives : Amikacin is one of the key second-line drugs for treatment of tuberculosis. Mutations at the codons 1400, 1401and1483 of the 16srRNA gene are associated with resistance to amikacin. The purpose of this study was to detect these mutations using PCR-RFLP method in multi-drug resistant (MDR) strains of Mycobacterium tuberculosis showing resistance to amikacin.
Methods : Susceptibility of strains (n=100) against first and second–line anti-tuberculosis drugs was performed by proportional method. Based on antimicrobial resistance pattern 97 strains were analyzed by PCR-RFLP method. rrs1096 and rrs1539 primers were used to amplify a 460bp region of the rrs gene. Then, the PCR products were digested using Tai 1 and Dde1 restriction enzymes. The results were analyzed by the SPSS software using Chi-square test.
Results : Based on results from proportional method, 63 strains (64.9%) were MDR (Multiple Drug Resistant), 26 (26.8%) and 8 (8.2%) strains were susceptible and non-MDR, respectively. Also, 13.4% and 6.1% of the strains were XDR (Extensively Drug Resistant) and TDR ( Totally drug resistant ) respectively. Using PCR-RFLP method, 7 (7.2%) strains were resistant and 90 (92.7%) strains were susceptible to amikacin respectively. Moreover, we found that the mutation at the codon 1400 was the most frequent mutations responsible for resistance to amikacin.
Conclusion : The PCR-RFLP method can be used as a supplemental method to detect resistance to amikacin however to increase our knowledge, mutatuions in several number of codons in rrs gene need to be studied.
Zahra Derakhshani Nezhad, Fatemeh Maryam Sheikolslami, Parisa Farnia, Zahra Deilami Khiabani, Rashid Ramazanzadeh, Mahdi Kazempoor, Mohammad Reza Masjedi , Ali Akbar Velayati,
Volume 12, Issue 3 (autumn 2012)
Background & Objectives: Ethambutol is one of the four main drugs in treatment of tuberculosis. The most common mutation associated with this drug resistance usually occurs in codon 306 of embB. The aim of this study was to detect ethambutol resistance using Allele-Specific PCR and Spoligotyping in various subtypes of Mycobacterium tuberculosis.
Methods : 140 sputum specimens were collected from suspected TB patients. They were digested and decontaminated using Pettrof method before culturing them on LJ medium. Drug susceptibility testing was performed on 106 culture positive specimens using proportional method. DNA was extracted from the isolated organisms and subsequently subjected to Allele-Specific PCR to detect any mutationin embB306. Spoligotyping was then used to determine the subtypes.
Results: Out of 106 cultures positive samples, 36 samples (33.9%) showed resistance to ethambutol using proportional method. Allele-Specific PCR assay identified 93 as sensitive and 13 (27.6%) as resistant strains. The results of PCR were in agreement with result of proportional method. The PCR method revealed that 61.5% of mutation occurred in the first and 38.5% in third nucleotides. Spoligotyping differentiated Mycobacterium tuberculosis strains into Beijing (10 9.4%), Bovis (2 1.8%), CAS (24 22.6%), EAI (1 0.9%), Haarlem (27 25.4%), LAM (5 4.7%), Manu (5 4.7%), T (27 25.4%) and U( 2 1,8%) families. The high frequency of mutation in embB gene was belonged to Haarlem, CAS and T subfamilies.
Conclusion: Based on results current study, mutations in the genes other than embB might have occurred in the resistant strains that gave negative result in Allele-Specific PCR assay. Therefore other mechanisms of resistance to this antibiotic should be investigated.
Samira Sheikh Ghomi , Parisa Farnia , Mojtaba Darbouy ,
Volume 14, Issue 2 (summer 2014)
Background & objectives: The rapid identification of patients carrying resistant Mycobacterium tuberculosis (M.TB) isolates is important for effective tuberculosis therapy. Unfortunately, during the recent years considerable numbers of isolates showed resistant to Rifampin (RIF) and Isoniazid (INH). The aim of this study was to rapidly identify resistant MTB isolates using molecular method. For this reason, the comparison between real-time PCR based on Taqman and HRM AssayS in detection of rpoB, inhA and katG genes mutation in clinical isolates were performed and analyzed.
Methods: The study carried out on Mycobacteriology Research Center (MRC) from 2012-2013. Classical susceptibility testing i.e., proportional method against INH and RIF was performed on eighty three M.TB isolates. Thereafter, multiplex and real-time PCR were performed on extracted DNA sample. The real-time PCR was based on Taqman and HRM assays. Mutation in genes rpoB, inhA and katG were detected.
Results: In overall, based on proportional and multiplex PCR method, 47 and 35 isolates were resistant to RIF and INH, respectively. Thirty of strains were resistant to both RIF and INH. The agreement of real-time PCR using Taqman was 88% for resistant and 84% for susceptible isolates, whereas the agreement of HRM was 96% and 30%, respectively. The sensitivity and specificity of Taqman in comparison to multiplex were 84% and 88%, respectively. In addition, the sensitivity and specificity of HRM were 30% and 96%, respectively.
Conclusion: Results documented that real-time PCR based on Taqman assay is more sensitive than HRM assay. Additionally, real-time PCR based on Taqman assay is a rapid, accurate and cost effective method in detection of Mycobacterium tuberculosis resistance.