جستجوی مقالات مرتبط با کلیدواژه « hsp65 » در نشریات گروه « پزشکی »

Nontuberculous mycobacteria (NTM) are a large family of acid-fast bacteria that are widely distributed in the environment. Although most NTM species are saprophytic, about 30% of these species are associated with human diseases. NTM and Mycobacterium tuberculosis complex have common microbiological characteristics, such as induce similar immune response and same clinical manifestations. However, disease caused by NTM is a diagnostic challenge for physicians, because it cannot readily be distinguished from tuberculosis on the basis of clinical history, tuberculin skin test results, radiological patterns, and initial laboratory reports. Therefore, accurate detection of NTM is necessary due to different therapeutic strategies and should be considered seriously.

In this study, 120 water samples were collected for isolation of NTM species, and cultured in a Lowenstein-Jensen medium after decontamination and processing. Then, accuracy and sensitivity of the three conserved genes (16S rRNA, rpoB and hsp65), were evaluated in identification of NTM species isolated.

In this study, 87 NTM colonies were isolated from water samples. The results of the sequence analysis of the three conserved genes showed that the hsp65 gene compared to other two genes has a high degree of accuracy and sensitivity.

Unlike hsp65 gene, partial sequence analysis of the 16S rRNA and rpoB genes does not seem to be sufficient for recognizing NTM species.

Non-tuberculosis mycobacteria is acid-fast bacteria that lives in environmental sources such as: water, soil, dust, milk and decaying vegetables. Based on Runyon’s classification these bacteria classified in tow group of slow and rapid growing mycobacteria that both of them isolated from clinical specimens.The purpose of this study is evaluation of three housekeeping genes in identification and differentiation of non-tuberculosis mycobacteria. In our study we obtained 16S rRNA, rpoB and hsp65 sequences of twenty two slow and rapid growing mycobacteria from Genebank (www.ncbi.nlm.nih.gov). Then this sequences aligned and transferred to MEGA 5.0 program. Finally phylogenetic relationships were determined by constructing 16S rRNA, rpoB and hsp65 genes tree using the neighbor-joining method with Kimura 2-Parameter model. Results and conclusion: Phylogenetic analysis based on 16S rRNA, rpoB and hsp65 gene sequences indicated that except of rpoB gene, other genes cannot identificated and separate of some species. Also we found that for identification both of rapid growth mycobacteria (RGM) and slow growth mycobacteria (SGM)rpoB gene is the best option.due to findings of this study, it seems that for appropriate and accurate identification of non-tuberculosis mycobacteria we must studied rpoB and hsp65 genes simultaneously

Mycobacterium avium complex (MAC) are ubiquitous in the environment which are the cause of disease in animals, birds and patients with immunodeficiency and healthy individual. The purpose of this study was to apply the multi-location sequencing method (MLSA) to identify mycobacterium avium complex.
In this study, the sequences of 16S rRNA, rpoB and hsp65 genes were collected from the GenBank for 8 subtypes of Mycobacterium avium complex. Then these sequences were aligned using clustalW2 software, and based on these genes, phylogenetic trees were constructed. Finally, using CLC Main benchwork software combined the sequence for each sub-species, and the phylogenetic tree was constructed with a neighbor-joining technique.
The results of the MLSA method were better than the separate study of 16S rRNA, rpoB, and hsp65 genes.
The MLSA method is a useful tool for identifying and differentiating Mycobacterium avium complex subtypes.

Due to immune deficiency diseases (cancer, transplant recipients and HIV) environmental mycobacteria infections are increasing. Forasmuch as the clinical symptons of environmental mycobacteria lung infections and tuberculosis are similar, due to difference of diet therapy between environmental mycobacterium infections and Mycobacterium tuberculosis, it is necessary to identify and differentiate Mycobacterium species. Molecular methods seem to be a useful tool for detection and differentiation of Mycobacterium species.

Nowadays, the importance of pathogenicity of non-tuberculosis mycobacteria is well known. Generally, this group, in addition to the respiratory system can cause lymph nodes, skin, soft tissue and bone disorders. Identification of Mycobacterium by culture and biochemical tests may take several weeks and may not be useful for definitive diagnosis. PCR-RFLP (PRA) technique of the hsp65 gene using HaeIII and BstEII enzymes is a precise method for species differentiation, in comparison to phenotypic methods. It is a quick and inexpensive method for detection of mycobacterial species. This study aimed to assess the prevalence of non-tuberculous mycobacteria isolated from the patients referring to tuberculosis center (TB) of Kashan University of Medical Sciences.
Material and The study included 106 patients who had been referring to TB Center of Kashan University of Medical Sciences, from 1391 to 1394. The samples were tested by biochemical diagnostic tests. At the same time identification of the strains was made by use of PRA. Amplification of 441-bp fragment was performed by PRA for detection of hsp65 gene. The PCR products were digested with HaeIII and BsteII enzymes and analysis was performed on the basis of electrophoresis.
Molecular analysis showed non-tuberculosis mycobacteria in 4(8.3%) sputum samples,i.e. one positive sample (o.9 %) for every one of the following strains: M. abscessus, M. senegalense, M. fortuitum and M.kansasii.
The results of this study showed that some cases of tuberculosis in Kashan are due to non-tuberculosis mycobacteria. Also use of PRA analysis of hsp65 gene for clinical specimens is a rapid and useful tool for identification of species of mycobacterium which is helpful for early diagnosis, treatment and control of tuberculosis.

Considering the increasing significance of diseases due to NTM all over the world, we investigated the burden of such diseases in our region. The aim of this study was to assess NTM prevalence from different clinical samples during a period of 8 years in Massih Daneshvari Hospital, in Iran. This descriptive study was performed on 8322 samples obtained from pulmonary TB patients in Mycobacteriology Research Center from 2004 -2012. Using Tb1 and Tb2 primers, a 190 bp fragment of IS6110 gene was amplified in order to identify Mycobacterium species. Specimens with negative IS6110 PCR results were analyzed with PCR-RFLP using hsp65 gene, for NTM investigation. Out of 8322 samples, we identified 124 (1.5%) strains of NTM. The mean age of the patients was 57 ± 18/9 years (age range: 7 - 88 years). 55/6 % of the patients were male. The most common species detected in our study were Mycobacterium simiae (44.3%), Mycobacterium chelonae (16.9%) and Mycobacterium kansasii (12.9%). We found a high prevalence rate of Mycobacterium simiae among our patients. Treatment protocols for NTM are different from the protocols for Mycobacterium tuberculosis complex, so early diagnosis of these species will be of great importance.

Polymerase chain reaction (PCR) coupled with Restriction Fragment Length Polymorphism analysis (RFLP) has been used for genotyping of Mycobacteria in recent years. While detailed differentiation of non tuberculosis Mycobacteria has been described by this technique, even in some species ability of this technique for molecular epidemiology has been proven, only a small number of Mycobacterium tuberculosis (MTB) strains have been studied. The present study was conducted to apply this method to an expanded population of MTB isolates. A total of 150 clinical isolates were collected from patients referred to TB reference unit, PHLS, Ahvaz, Iran. Acid fast staining was performed for the isolates and they were identified as MTB by using conventional culture and biochemical tests. The PCR-RFLP method uses a simple DNA extraction followed by a PCR step based on amplification of a 439 bp fragment of hsp65 gene involving genus specific primers. The restriction enzyme analysis was then performed by digestion of products with HaeIII and BstEII enzymes. Our results showed that 145 clinical isolates (96.6%) showed the identical restriction patterns similar to M. tuberculosis reference strains equal to 165/140/72 bp fragments for HaeIII and 250/120/82 bp fragments for BstEII digests. Three different patterns were observed for five clinical strains in HaeIII digest as 165/145 bp (three isolates), 180/100/80 bp (one isolate) and 194/72 bp (one isolate), while their BstEII digestion patterns showed no variation and were similar to other isolates. Our results showed that in clinical strains of mycobacterium tuberculosis, few polymorphisms in hsp65 fragment might be present