title: Mutation pattern in rifampicin resistance determining region of rpoB gene in multidrug-resistant Mycobacterium tuberculosis isolates from Pakistan.
abstract: The current study was undertaken to characterize the RRDR rpoB gene mutations among the rifampicin-resistant Mycobacterium tuberculosis (MTB) isolates from Pakistan. Rifampicin mutation patterns were analyzed by using PCR followed by rpoB gene sequencing. Among the 1080 referred TB cases, 63 (6%) were resistant against at least one first-line TB drug. Out of these 63 resistant isolates, 24 isolates (38%) were found to be resistant to isoniazid and rifampicin. Sequence analysis of multidrug-resistant tuberculosis (MDR-TB) isolates detected a single mutation in the RRDR region of the rpoB gene at codon 531, 516, 512, 528 and 533; however, 5 MDR-TB isolates lack any mutation in the RRDR region. A double mutation was observed in 1 MDR-TB isolate at codon 512 and 516 which are reported for the first time from Pakistan. Moreover, in 1 isolate a novel silent mutation was observed at codon 528. Further studies about these mutations may be helpful in the development of diagnostic tools for the detection of MTB in a high TB endemic area like Pakistan.
authors.affiliation: Institute of Biochemistry and Biotechnology, University of Veterinary and Animal Sciences, Lahore, Pakistan; Department of Bacteriology, Institute of Public Health, Lahore, Punjab, Pakistan.
authors.forename: Obaidullah
authors.initials: O
authors.lastname: Qazi
authors.affiliation: Department of Microbiology, Kohat University of Science and Technology, Kohat, Pakistan. Electronic address: hazirrahman@hotmail.com.
authors.forename: Hazir
authors.initials: H
authors.lastname: Rahman
authors.affiliation: Department of Bacteriology, Institute of Public Health, Lahore, Punjab, Pakistan.
authors.forename: Zarfishan
authors.initials: Z
authors.lastname: Tahir
authors.affiliation: Department of Microbiology, Kohat University of Science and Technology, Kohat, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Qasim
authors.affiliation: Department of Microbiology, Kohat University of Science and Technology, Kohat, Pakistan.
authors.forename: Sajid
authors.initials: S
authors.lastname: Khan
authors.affiliation: Department of Microbiology, University of Veterinary and Animal Sciences, Lahore, Pakistan.
authors.forename: Aftab
authors.initials: A
authors.lastname: Ahmad Anjum
authors.affiliation: Institute of Biochemistry and Biotechnology, University of Veterinary and Animal Sciences, Lahore, Pakistan.
authors.forename: Tahir
authors.initials: T
authors.lastname: Yaqub
authors.affiliation: Institute of Biochemistry and Biotechnology, University of Veterinary and Animal Sciences, Lahore, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Tayyab
authors.affiliation: Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, Pakistan.
authors.forename: Nawab
authors.initials: N
authors.lastname: Ali
authors.affiliation: Institute of Biochemistry and Biotechnology, University of Veterinary and Animal Sciences, Lahore, Pakistan.
authors.forename: Sehrish
authors.initials: S
authors.lastname: Firyal
keywords: Multidrug-resistant isolates; Mycobacterium tuberculosis; RRDR rpoB gene mutations; Sequencing