Molecular testing for Mycobacteria tuberculosis is used for the rapid and high specificity and sensitivity detection of these microorganisms from a variety of biological materials.
The Mycobacterium tuberculosis complex is a group of pathogenic microorganisms responsible for causing tuberculosis (TB) in humans. They can not be stained with the classical microbiological Gram staining except with the acid-fast staining (Ziehl-Neelsen), they are non-motile, obligate aerobic, and are related microorganisms with the Actinomycetes. Mycobacterium species within this group are characterized by 99.9% nucleotide similarity and have identical 16S rRNA sequences, but can differ greatly in terms of host tropism, phenotype, and pathogenesis. Some members of the group infect only one host species, while others such as Mycobacterium bovis have a wide range of hosts.
Transmission is usually by inhalation of infected droplets, with the bacteria being able to remain in the airway for long periods of time. In the alveoli, macrophages phagocytes Mycobacteria, but some bacteria manage to survive and grow inside the macrophages, avoiding the reaction of the host's immune system. They then cause cell death of macrophages, allowing Mycobacteria to spread through the blood to the kidneys, brain, bones, and lymph nodes. Mycobacteria of this group divide every 15 to 20 hours, a time that is extremely slow compared to other microorganisms. Mycobacteria can survive in the dry state for weeks and are resistant to relatively mild disinfectants, but can only grow in a host organism.
Tuberculosis most often occurs as a lung infection resulting in pulmonary tuberculosis, which has symptoms such as weight loss, loss of appetite, fever, sweating, and cough. Extrapulmonary forms of tuberculosis are the result of bacterial spread from the lungs and cause different symptoms, depending on the area of infection.
Species of the Mycobacterium tuberculosis complex include Mycobacterium tuberculosis, the most common cause of tuberculosis, Mycobacterium africanum, a species found in West Africa that causes tuberculosis in humans, Mycobacterium canettii which is also found in Africa, Mycobacterium bovis which causes tuberculosis in cattle and humans and Mycobacterium microti which causes tuberculosis in rats but has recently been reported to infect humans.
Laboratory test results are the most important parameter for the diagnosis and monitoring of all pathological conditions. 70%-80% of diagnostic decisions are based on laboratory tests. Correct interpretation of laboratory results allows a doctor to distinguish "healthy" from "diseased".
Laboratory test results should not be interpreted from the numerical result of a single analysis. Test results should be interpreted in relation to each individual case and family history, clinical findings and the results of other laboratory tests and information. Your personal physician should explain the importance of your test results.
At Diagnostiki Athinon we answer any questions you may have about the test you perform in our laboratory and we contact your doctor to get the best possible medical care.