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Analysis of Naturally Occurring Resistant Mutations to Hepatitis C Virus NS3 Protease Inhibitors: A Preliminary Study in South of Iran.

Afrasiabi M, Hosseini SY, Yaghobi R, Fattahi MR, Ardebili M, Khodadad M - Jundishapur J Microbiol (2015)

Bottom Line: Then, the obtained sequences were compared with the reference sequences and final phylogenic tree was constructed.Checking different clones of this patient confirmed V36L, as the dominant mutation while R155K was detected only in a few cases.It seems that checking HCV patients before protease inhibitor treatment are necessary in the region.

View Article: PubMed Central - PubMed

Affiliation: Gastroenterohepatology Research Center (GEHRC), Shiraz University of Medical Sciences, Shiraz, IR Iran.

ABSTRACT

Background: Exploring the rate of naturally occurring NS3 protease mutants in HCV infected population is influential in the future therapeutic approaches.

Objectives: This study explored naturally occurring resistant mutations to protease inhibitors in a pilot study.

Patients and methods: We analyzed NS3 gene sequences in 7 HCV infected patients, referred to the central liver center, south of Iran. The protease domain was amplified by PCR followed by product extraction. Amplified NS3 genes were cloned by TA/cloning system. For each patient, clonal-sequencing was performed to improve mutation detection sensitivity. Then, the obtained sequences were compared with the reference sequences and final phylogenic tree was constructed. Afterwards, the sequences were studied to investigate point mutations.

Results: Phylogenetic analysis between reference and amplified sequences demonstrated high similarity of all sequences with genotype 1. Interestingly, crucial protease resistant mutations were detected in V36 and R155 positions in one patient's sequence. Checking different clones of this patient confirmed V36L, as the dominant mutation while R155K was detected only in a few cases.

Conclusions: As revealed, naturally occurring resistant mutations, especially R155K in protease sequence were identified in 1 out of the 7 patients, so the rate of such mutations is estimated to be high. It seems that checking HCV patients before protease inhibitor treatment are necessary in the region.

No MeSH data available.


Detection of Critical Mutations in One Patient (Nominated as MNR1) During Screening by Comparison With the Reference SequencesOn the top, R155K mutation (replacing of lysine by arginine in the position 155 aa) and on the below, V36L mutation (valine to leucine substitution in the position 36 aa) were highlighted in square after sequence alignment by MEGA4 software.
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fig23113: Detection of Critical Mutations in One Patient (Nominated as MNR1) During Screening by Comparison With the Reference SequencesOn the top, R155K mutation (replacing of lysine by arginine in the position 155 aa) and on the below, V36L mutation (valine to leucine substitution in the position 36 aa) were highlighted in square after sequence alignment by MEGA4 software.

Mentions: As the most important step, sequences were checked one by one to screen critical characterized point mutations and variations in nucleotide and amino acid sequences. Surprisingly, 2 critical mutations, including R155K (replacing of lysine by arginine in the position 155 aa) and V36L (valine to leucine substitution in the position 36 aa) were revealed in one (Shr-MNR1-KJ564300) out of 7 patients (Figures 3 and 4).


Analysis of Naturally Occurring Resistant Mutations to Hepatitis C Virus NS3 Protease Inhibitors: A Preliminary Study in South of Iran.

Afrasiabi M, Hosseini SY, Yaghobi R, Fattahi MR, Ardebili M, Khodadad M - Jundishapur J Microbiol (2015)

Detection of Critical Mutations in One Patient (Nominated as MNR1) During Screening by Comparison With the Reference SequencesOn the top, R155K mutation (replacing of lysine by arginine in the position 155 aa) and on the below, V36L mutation (valine to leucine substitution in the position 36 aa) were highlighted in square after sequence alignment by MEGA4 software.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4644313&req=5

fig23113: Detection of Critical Mutations in One Patient (Nominated as MNR1) During Screening by Comparison With the Reference SequencesOn the top, R155K mutation (replacing of lysine by arginine in the position 155 aa) and on the below, V36L mutation (valine to leucine substitution in the position 36 aa) were highlighted in square after sequence alignment by MEGA4 software.
Mentions: As the most important step, sequences were checked one by one to screen critical characterized point mutations and variations in nucleotide and amino acid sequences. Surprisingly, 2 critical mutations, including R155K (replacing of lysine by arginine in the position 155 aa) and V36L (valine to leucine substitution in the position 36 aa) were revealed in one (Shr-MNR1-KJ564300) out of 7 patients (Figures 3 and 4).

Bottom Line: Then, the obtained sequences were compared with the reference sequences and final phylogenic tree was constructed.Checking different clones of this patient confirmed V36L, as the dominant mutation while R155K was detected only in a few cases.It seems that checking HCV patients before protease inhibitor treatment are necessary in the region.

View Article: PubMed Central - PubMed

Affiliation: Gastroenterohepatology Research Center (GEHRC), Shiraz University of Medical Sciences, Shiraz, IR Iran.

ABSTRACT

Background: Exploring the rate of naturally occurring NS3 protease mutants in HCV infected population is influential in the future therapeutic approaches.

Objectives: This study explored naturally occurring resistant mutations to protease inhibitors in a pilot study.

Patients and methods: We analyzed NS3 gene sequences in 7 HCV infected patients, referred to the central liver center, south of Iran. The protease domain was amplified by PCR followed by product extraction. Amplified NS3 genes were cloned by TA/cloning system. For each patient, clonal-sequencing was performed to improve mutation detection sensitivity. Then, the obtained sequences were compared with the reference sequences and final phylogenic tree was constructed. Afterwards, the sequences were studied to investigate point mutations.

Results: Phylogenetic analysis between reference and amplified sequences demonstrated high similarity of all sequences with genotype 1. Interestingly, crucial protease resistant mutations were detected in V36 and R155 positions in one patient's sequence. Checking different clones of this patient confirmed V36L, as the dominant mutation while R155K was detected only in a few cases.

Conclusions: As revealed, naturally occurring resistant mutations, especially R155K in protease sequence were identified in 1 out of the 7 patients, so the rate of such mutations is estimated to be high. It seems that checking HCV patients before protease inhibitor treatment are necessary in the region.

No MeSH data available.