DETECTION OF gyrA GENE MUTATION REGION IN FLUOROQUINOLONE RESISTANT Mycobacterium tuberculosis ISOLATE FROM SURABAYA INDONESIA

Fluoroquinolones are an important class of antibiotics used in the management of bacterial diseases and drug resistancetuberculosis. This study aimed to detect gyrA gene mutations regions as the mechanism of fluoroquinolone resistance inMycobacterium tuberculosis by sequencing of the quinolone resistance determining region (QRDR) of gyrA, one of the genesencoding DNA gyrase. Mutations affecting amino acids at positions 74, 90, 91 and 94 have been most commonly associated withresistance. Drug susceptibility testing of Mycobacterium tuberculosis was performed by the culture method of proportion, includingsusceptibility to ofloxacine. DNA was extracted by boiling method. Nucleic acid was amplified by PCR, targeting the region of gyrAusing primers gyrA-F ( 5’CAG CTA CAT CGA CTA TGC GA 3’) andgyrA-R (GGG CTT CGG TGT ACC TCA T) and sequenced withABI 377 sequencer. Sequences were analysed to identify mutations associated with fluoroquinolone resistance. There were 5ofloxacine resistant Mycobacterium tuberculosis isolates which were PCR processed for gyrA. The amplicons product were 320 bpfrom five these isolates. No mutations were identified in gyrA specifically at sites corresponding with codons 90, 91, and 94, but all 5isolates had the mutations S95T. These findings suggest that the gyrA mutation, S95T is suspected as the polymorphism influoroquinolone resistant Mycobacterium tuberculosis. However, further investigation is required to identify the mechanism offluoroquinolone resistance in Mycobacterium tuberculosis. (FMI 2014;50 139-142)