AffiPCR® MTB MDR Real Time PCR

Target Disease Type: Respiratory Infections

Specific Application: Mycobacterium tuberculosis detection and differenziatio

Storage and Shipping : 4 weeks

MTB MDR RT-PCR H3611-50FRT DataSheet

INTRODUCTION

Tuberculosis (abbreviated as TB for tubercle bacillus) is a common and deadly infectious disease caused by mycobacteria, mainly Mycobacterium tuberculosis. Tuberculosis most commonly attacks the lungs (as pulmonary TB) but can also affect the central nervous system, the lymphatic system, the circulatory system, the genitourinary system, bones, joints and even the skin. Other mycobacteria such as Mycobacterium bovis, Mycobacterium africanum and Mycobacterium microti can also cause tuberculosis. Over one-third of the world's population has been infected by the TB bacterium, and new infections occur at a rate of one per second. Not everyone infected develops the full-blown disease; asymptomatic, latent TB infection is most common. However, one in ten latent infections will progress to active TB disease, which, if left untreated, kills more than half of its victims.

Early diagnosis of tuberculosis makes effective treatment possible and increases the probability of clinical outcome owing to quite effective antituberculosis therapy, however the tuberculosis diagnosis has certain difficulties. Effective first line anti-tuberculosis drugs like isoniazid (INH) were developed but shortly after their introduction a resistance was reported (Crofton and Mitchison, 1948) . In the 60s rifampicin (RIF) was introduced and this led, using combination therapy, to a decline in both drug resistant and drug susceptible TB. As a consequence, funding and interest in TB control programs declined: no effective monitoring of drug resistance was carried out for the following 20 years (Espinal, 2003) . It is now known that resistance to first-line drugs is linked to specific mutations in MTB genes: the most significant ones are katG and inhA for INH resistance, rpoB for RIF resistance.

Up to date it is well known that 95% rifampin (RMP) resistance is associated with rpoB gene mutations and most of mutations frequency, associated with isoniazid (INH) resistance, are discovered in 315 codon of katG gene and in the regulatory region of inhA gene. Drug resistance surveillance was restored in the late 90s, with reports showing also multidrug resistance (MDR) to both RIF and INH. A WHO study showed that in the period 2000-2004 about 20% of clinical samples tested showed MDR.

Second line drugs are now available but they are less efficient and more expensive. So it becomes critical to detect drug resistant TB early, allowing an appropriate and effective treatment for the disease, avoiding wasting time and resources using non effective drugs.

Moreover, the spread of multidrug resistant strains needs to be constantly monitored to avoid a decrease in treatment efficiency. Due to MTB slow growth rate, cultural methods of detection usually used are really slow, taking up to 20 days to have a valid result on drug resistance of the sample tested. The application of a molecular biology technique such as real-time PCR, makes this detection much faster than cultural methods (valid result in 1-3 day), highly precise, specific and sensitive.

INTENDED USE

The kit MTB MDR Resistance Real-TM is a test for Real Time PCR qualitative detection of Mycobacterium tuberculosis resistance to Rifampicin and Isoniazid in MTB positive samples.

PRINCIPLE OF ASSAY

kit MTB MDR Resistance Real-TM is a Real-Time Amplification PCR test which detects mutations in RpoB region for Rifampicin resistance and mutations in katG and inhA regions for Isoniazid resistance. Results are analysed using automated spreadsheet file supplied with CD inside the kit’s box.