Bachelor Thesis: Genetic analysis of fluoroquinolone resistence in suspect of XDR Mycobacterium tuberculosis samples from Bandung, Indonesia

[:id]Mandala Ajie, is one of microbiology undergraduate student, batch 2012. Recently, he just finished his working thesis undersupervision of Dr. Ernawati Arifin G. (SITH-ITB) and Lidya Chaidir (BLK). His research focused on analysis of suspect of extensively drug resistant (XDR) Mycobacterium tuberculosis strain from sample in Bandung, Indonesia by using molecular approach with the goal to determine the number of pre-XDR TB infection in Bandung, Indonesia.

Extensively drug resistant Mycobacterium tuberculosis (XDR MTB) is defined as a multidrug resistant (MDR) MTB strains that not only are resistant to first line drugs isoniazid (INH) and rifampicin (RIF), but also second line drug fluoroquinolone (FQ) and at least one of three injectable aminoglycosides. It represents 9.6% of resistant MTB infection and, due to its tenacity, becomes an emerging threat in tuberculosis eradication program. In fact, there is zero published paper that studies the prevalence of XDR TB in Indonesia.

FQ resistance was determined by analyzing the mutation in gyrA, a gene that codes gyrase subunit-A, the target of FQ in MTB. Thirteen samples of suspect MDR MTB was picked from Pusdi TB/HIV FK Universitas Padjadjaran Bandung and then being analysed. His results showed that no FQ-resistance-confering mutation occurred in all samples tested, suggesting all samples are susceptible to FQ (not pre-XDR strain). However, the susceptibility of phenotypic drugs needs to be conducted for confirmation.

In addition, the analysis showed that all samples might belong to principal genetic group (PGG) 1 based on amino acid substitution in codon 95 of gyrA. PGG 1 is a group of MTB strains that are characterized by certain polymorphisms in katG and gyrA gene. One of the members of PGG 1 is MTB Beijing genotype, which is presumed to be able to develop multiple drug resistance at a higher rate than other strains, making it a threat in TB eradication program. Spoligotyping is needed to confirm the strain of all samples tested.[:]