SALUBRIS-medica

Tuberculosis:

The oldest but still the biggest health problem around the world !

(Please click here for a movie from WHO / Stop TB)

DIAGNOSIS OF TUBERCULOSIS

Current problems:

Microscopy:

• Rapid diagnosis
• Low sensitivity. Concentration may increase sensitivity up to hundred folds
• Can not differentiate tuberculosis and non-tuberculosis mycobacteria
• False positive results
• Samples must always be studied with one positive and one negative control

Culture:

• The gold standard method for tb diagnosis
• Culture in LJ media takes 3 to 6 weeks
• Commonly used rapid culture systems have disadvantages:
  Radioactive, expensive, blood containing samples give false results
• All culture methods require decontamination

Problems in decontamination and concentration

• Mycobacteria may be killed during decontamination and concentration when NaOH is used alone
• “N-acetyl-L-cysteine” allows lowering the concentration of NaOH. NALC is degraded within 24 hours when mixed with NaOH
• The use of HCl for neutralization, makes it very difficult to adjust the pH
• Use of phosphate buffer assures the appropriate adjustment of pH
• Phosphate buffer is one of the main sources of contamination. Buffer that will be used for each sample should be sterilized and stored separately
• Decontamination and concentration should be done in 50 ml screw capped centrifuge tubes and using an appropriate centrifuge

SALUBRIS' solutions:

SALUBRIS-medica offers innovative, easy and affordable solutions for the diagnosis of tuberculosis.

MYCOPROSAFE®:

• Decontamination and concentration kit
• Permits easy application of NALC-NaOH decontamination and concentration
• It includes all the materials ready to use
• Materials are individually packed for each sample avoiding risks of cross-contamination

Susceptibility testing

• When LJ media is used, heating temperature and duration (85°C for 50 min.) should be exact and equal for each tube
• Middlebrook is better since the drugs are added at 50°C and are not inactivated by heating. However it is difficult to prepare Middlebrook agar
• Commonly used automated systems are not practical; they are expensive
• Molecular methods can provide rapid results but only available for some drugs; hard to apply routinely

Löwenstein-Jensen media

Special coagulator used to keep the tubes at exactly 85°C for 50 minutes

ANTI-TB KIT®:

• Allows susceptibility testing by proportion method using LJ media
• Suspension tube containing glass beads and buffer with Tween 80 allows making a homogeneous inoculum easy and fast
• Contains ready to use 10-2 and 10-4 dilution tubes
• Standard concentration of drugs are obtained by keeping each tube at 85°C for 50 minutes
• The concentrations of drugs are controlled by quality control strains
• Four types of kit according to preferred type of application
• Availability of media for susceptibility testing for minor tb drugs

TK MEDIA®:

• Rapid culture medium
• Original red color turns to yellow by mycobacterial growth before the colonies become visible
• It differentiates contamination by turning to green when many other species of bacteria or fungi grow
• It is not radioactive. It does not create a radioactive waste problem
• Protective cap makes inoculations and subcultures easy and safe
• TK SLC is the selective type containing five different antimicrobials to inhibit the growth of other bacterial species and fungi
• TK PNB allows rapid differentiation of tuberculosis and non-tuberculosis mycobacteria
• TK ANTI TB KIT allows susceptibility test easy and fast

MYCOLOR TK®:

• Automated incubator reader for TK MEDIA
• User friendly software facilitates dta entry and access to patients information
• Evaluation of all culture tubes at a glance
• Growth and contamination curves for each sample
• Expert system prediction of growth and contamination

Molecular diagnosis

• Sensitivity high; may have high rate of false positive results
• May have high rate of false negative results if not standardized well
• Can not differentiate living or dead (or dormant) organisms
• Results should be evaluated together with other findings
• They require sophisticated expensive instruments and experienced personnel

MYCO TYPE ALL®:

• Molecular species identification kit
• A part of hsp65 gene is amplified by PCR
• PCR products are digested by BstEII and HaeIII enzymes
• Fragments evaluated by electrophoresis comparing to original markers, Myker B and Myker H, developed for this purpose