|
|
|
 |
Search published articles |
 |
|
Showing 3 results for Masjedi
Shahram Habibzadeh, Latif Gachcar, Mohammad Reza Masjedi, Ali Akbar Velayati ,
Volume 5, Issue 2 (Summer 2005)
Abstract
Background & Objectives: Some special characteristics of mycobacterium tuberculosis such as long time incubation period in culture media needed for colony appearance, unavailability of serologic methods for diagnosis, along with necessity of starting treatment in the patients with severe conditions as well as isolation limitations requires the introduction of rapid and innovative diagnostic tests. On the other hand, some diagnostic tests such as Polymerase Chain Reaction (PCR) require special experimental conditions which are not easily available to clinicians. This study was designed to determine the diagnostic value of serum adenosine deaminasae in pulmonary tuberculosis and evaluate its efficacy in pulmonary tuberculosis diagnosis. Methods:This cross-sectional study started in spring 2002. Continuous sampling was done and admitted patients were observed, examined and interviewed using a diagnotic test. All patients admitted with a suspected pulmonary tuberculosis diagnosis based on physical examination, history and chest X-Ray results were followed up for six months to ensure that mycobacterium tuberculosis infection was appropriately diagnosed. Blood samples were taken for serum ADA and complementary diagnostic tests. Following certain necessary tests and work-ups patients with or without tuberculosis were identified. Results: 131 Patients were evaluated completely. 103 had tuberculosis and 28 patients had other diseases. No statistically significant difference was found between mean level of serum ADA in two groups. But a serum level of ADA greater than 51 U/L was associated with 90% positive predictive value and specificity in differentiating two groups. Conclusion: Serum ADA is not a suitable test for pulmonary tuberculosis diagnosis.
Parisa Tahmasebi, Fatemeh Maryam Sheikolslami , Parisa Farnia , Majid Sadeghizadeh, Rashid Ramazanzadeh, Mahdi Kazempoor, Mohammadreza Masjedi , Ali Akbar Velayati,
Volume 11, Issue 4 (winter 2011)
Abstract
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)
Abstract
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.
|
|
.png)
.png)
