scholarly journals Amplification Refractory Mutation System – Polymerase Chain Reaction for Rapid Detection of rpoB Gene Mutations in Mycobacterium tuberculosis

2017 ◽  
Vol 5 (1) ◽  
pp. 81-85 ◽  
Author(s):  
Hemanta Kumari Chaudhary ◽  
Mitesh Shrestha ◽  
Prakash Chaudhary ◽  
Bal Hari Poudel

Multidrug-resistant tuberculosis (MDR-TB) has become a serious worldwide threat including in Nepal. MDR-TB refers to the pathological condition whereby Mycobacterium tuberculosis becomes resistant to the first line of drug treatment i.e. rifampin and isoniazid. Resistance to rifampin (RIF) is mainly caused by the mutations in the rpoB gene which codes for the β-subunit of RNA polymerase. In this study, Amplification Refractory Mutation System – Polymerase Chain Reaction (ARMS – PCR) technique has been used to detect mutations in the rpoB gene of Mycobacterium tuberculosis. Total DNA samples of 34 phenotypic MDR-TB were subjected to ARMS – PCR using three different codon specific primers (516, 526 and 531). These three codons occupy large portion of total mutation responsible for rifampin resistance. Out of the total DNA samples, all were bearing mutation in at least one of the three codons mentioned. Of those bearing mutation, the highest number had mutation in codon 531 (97.05 %) followed by codon 516 (17.64 %) and finally in codon 526 (11.76%) respectively. Hence, ARMS – PCR may be used as an alternative diagnostic technique for detection of rifampin resistance in Mycobacterium tuberculosis strains, especially for a developing country like Nepal.Int. J. Appl. Sci. Biotechnol. Vol 5(1): 81-85

Author(s):  
Ali Bahari ◽  
Mohammad Hashemi ◽  
Gholam Reza Bahari ◽  
Tahereh Fakharian ◽  
Sina Gerayli ◽  
...  

Background: Selecting patients for new direct acting antiviral treatment of HCV has prompted a conflicting matter worldwide because of its high cost and limited availability. Genotyping of IL28B polymorphisms will aid clinical decision making for identifying priorities of urgent treatment in resource-limited countries. Objectives: The aim of the present study was to design a simple tetra-primer amplification refractory mutation system–polymerase chain reaction (T-ARMS-PCR) for genotyping of the rs8099917 and rs12979860 IL28B gene polymorphisms. Furthermore, we identify the correlation of variables such as gender, serum ALT level, histology of liver and baseline viral load with these polymorphisms. Patients and Methods: We efficiently designed a T-ARMS-PCR for detection of rs12979860 and rs8099917 IL28B gene polymorphisms. Using this method, we genotyped 148 hepatitis C patients. To ensure T-ARMS genotyping quality, we, regenotyped samples with the PCR- sequencing method. Results: Results of genotyping of rs12979860 and rs8099917 by T-ARMS PCR method were 100% concordant with the sequencing results. Among these 148 patients with chronic hepatitis C, the frequency of the rs12979860 CT, TT and CC genotypes was 72.3%, 14.2% and 13.5%, respectively and the frequency of the rs8099917 TT, GT and GG genotypes was 58.1%, 38.5% and 3.4%. Low frequency (2.7%) of association of two unfavourable homozygous genotypes (TT rs12979860 / GG rs809917) as well as 56.7% of association of 3 or 4 favorable alleles could explain good response of Iranians to HCV treatment with interferon-based regimens. About correlation of polymorphisms with different variables, only high viral load showed a statistically significant correlation to unfavorable genotype of TT rs12979860 ( p value = 0/05 ) and there was no correlation of  serum ALT level, gender and  histology of liver to IL28B genotypes. Conclusions: We report that rs8099917 polymorphisms could predict outcomes better than rs12979860 in Iranian HCV patients.


Author(s):  
Naoko Okayama ◽  
Kozue Fujimura ◽  
Junji Nakamura ◽  
Yutaka Suehiro ◽  
Yuichiro Hamanaka ◽  
...  

AbstractTetra-primer amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) is a new efficient method for single-nucleotide polymorphism (SNP) genotyping. To determine the optimal conditions for ARMS-PCR we attempted to genotype ten SNPs. DNA was extracted from the peripheral blood of 168 unrelated healthy Japanese volunteers. Two problems inhibited uniform efficiency of the amplification of three bands. The first problem was the lower amplification efficiency of the shorter and allele-specific products compared with the largest product. This phenomenon was overcome by increasing the relative concentration of the inner primers. The second problem was non-specific amplification of the shorter products. To reduce the amplification of these nonspecific bands, adjusting any one of the following PCR conditions was effective: i) reducing the ratio of the inner primer concentration relative to that of the outer primers; ii) increasing the annealing temperature for the initial 5–10 cycles; iii) hot start PCR. With these procedures all ten of the SNPs were successfully genotyped. Our present data may be useful in the further application of tetra-primer ARMS-PCR to SNP genotyping.


1994 ◽  
Vol 40 (12) ◽  
pp. 2235-2239 ◽  
Author(s):  
M Y Tsai ◽  
N Q Hanson ◽  
K R Copeland ◽  
I Beheshti ◽  
U Garg

Abstract We used the amplification refractory mutation system (ARMS)--a polymerase-chain-reaction-based method--to determine the 3206 T-to-G polymorphism on exon 4 of the apolipoprotein (apo) C III gene. Apo C III is an inhibitor of the enzyme lipoprotein lipase (EC 3.1.1.34). Previous studies have demonstrated that a polymorphism at nucleotide 3175 on exon 4 of this gene is associated with hypertriglyceridemia. We studied 45 hypertriglyceridemic and 46 age-matched controls for the 3206 T-to-G polymorphism. The results showed a significant difference in the distribution of the genotypes with respect to this allele between the hypertriglyceridemic and control individuals. We also determined the presence of the SacI site at nucleotide 3175 in these same individuals and found no significant difference in SacI genotypes between the two groups. This study reaffirms the usefulness of ARMS as a simple, reliable method for detecting mutations and polymorphisms in clinical and epidemiological studies.


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