<p>UVOD: Tuberkuloza je odavno poznata bolest koja i danas u 21. veku još uvek predstavlja veliki javnozdravstveni problem, uprkos primeni moćnih antituberkuloznih lekova. Trećina svetske populacije inficirana je bacilom tuberkuloze. Svake godine oboli oko osam miliona, a umre oko dva miliona ljudi, zbog čega je tuberkuloza i dalje infektivno oboljenje sa najvećom stopom smrtnosti. Kasna dijagnoza, multirezistentna tuberkuloza i udruženost sa HIV infekcijom predstavljaju jednu od najvećih prepreka za efikasnu kontrolu ove bolesti u svetu. Rano otkrivanje se oslanja na kvalitetnu bakteriološku dijagnostiku koja je kamen temeljac svakog nacionalnog programa za kontrolu tuberkuloze. Brza i tačna mikrobiološka dijagnostika predstavlja osnovu programa kontrole tuberkuloze i zbog toga je uvođenje novih i brzih laboratorijskih testova od veoma velikog značaja. Razvijen je novi komercijalno dostupni imunohromatografski test koji se zasniva na detekciji antigena MPT64 glavnog sekretovanog proteina M. tuberculosis. Test je brz i pouzdan u identifikaciji izolovanih sojeva M. tuberculosis i jeftiniji je od konvencionalnih biohemijskih i molekularnih testova. CILJ: Ciljevi istraživanja su bili da se evaluiraju karakteristike novog brzog imunohromatografskog testa u identifikaciji mikobakterija izolovanih iz respiratornih uzoraka bolesnika sa tuberkulozom pluća i referentnih sojeva klinički značajnih vrsta netuberkuloznih mikobakterija (NTM). MATERIJAL I METODE: Istraživanje je sprovedeno u periodu od 1.1.2010. do 31.12.2013. i obuhvatilo je 43563 respiratornih uzoraka dobijenih od bolesnika hospitalizovanih u Institutu za plućne bolesti Vojvodine. Iz obrađenih respiratornih uzoraka izolovano je 3469 izolata mikobakterija. Identifikacija do nivoa vrste urađena je primenom standardnih biohemijskih testova, molekularnog testa (GenoType® Mycobacterium) i imunohromatografskog testa (BDMGIT Tbc). U istraživanje je uključeno 100 sojeva Gram pozitivnih i Gram negativnih bakterija (n = 19 vrsta) izolovanih iz respiratornih kliničkih uzoraka. Identifikacija do nivoa vrste je potvrđena komercijalnim identifikacionim sistemima. REZULTATI: U toku četvorogodišnjeg istraživanja izolovano je 3469 izolata mikobakterija iz respiratornih uzoraka. U ispitivanom periodu ne postoji opadajući trend izolacije mikobakterija što potvrđuje i koeficijent korelacije (r = 0,31). Svi izolati mikobakterija su identifikovani konvencionalnim biohemijskim ispitivanjima koja pokazuju da je 89% od svih izolata identifikovano kao Mycobacterium tuberculosis (M. tuberculosis), a 11% izolata kao NTM. Mycobacterium xenopi je bila najzastupljenija NTM vrsta identifikovana kod 55,3% izolata. Nakon biohemijske identifikacije kod 300 izolata M. tuberculosis i 100 izolata NTM, identifikacija je potvrđena komercijalno dostupnim molekularnim i imunohromatografskim testom. Na osnovu rezultata testiranja mikobakterija imunohromatografskim testom, senzitivnost, specifičnost, pozitivne i negativne prediktivne vrednosti bile su: 99,7%, 100%, 100% i 99%. U poređenju imunohromatografskog testa sa konvencionalnim biohemijskim ispitivanjima nije nađena statistički značajna razlika (p> 0,5). Kappa vrednost testa je iznosila 0,993, a interval poverenja CI =0,98 – 1,00. U poređenju imunohromatografskog sa molekularnim testom vrednost kappa je iznosila 0,993, a interval poverenja CI = 0,98 – 1,00. Slaganje rezultata je potvrđeno i McNemar testom sa vrednošću 0,99. Utvrđena je stabilnost sekretovanog antigena MPT64 i posle 5 godina od prvog testiranja. ZAKLJUČAK: Visoka senzitivnost i specifičnost imunohromatografskog testa omogućuju tačnu i preciznu identifikaciju M. tuberculosis kao i pouzdanu diferencijaciju M.tuberculosis od NTM – a. Imunohromatografski test može da predstavlja zamenu za konvencionalne biohemijske i molekularne testove u identifikaciji M. tuberculosis. Jeftiniji je, jednostavniji za izvođenje i brže se dobijaju rezultati čime seskraćuje vreme za postavljanje dijagnoze.</p> / <p>INTRODUCTION: Tuberculosis (TB) has been known as a disease for a long time, but nevertheless it represents a major public health issue even nowadays in the 21st century, despite potent antituberculous drugs applied. One third of the world population is infected by the TB bacillus. About eight million people get infected and two million die of tuberculosis in a year, so tuberculosis is still an infectious disease with the greatest mortality rate. Late diagnosis, multiresistant tuberculosis and concomitant HIV infection interfere mostly with an efficient control of the disease all over the world. Early TB detection largely depends on the high-quality bacteriological diagnostics, which is the corner stone of each national TB control programme. A fast and accurate microbiological TB diagnosis plays a crucial role in any TB control programme. It is therefore very important to introduce new and fast laboratory tests. A novel commercially available immunochromatographic test has been designed, based on the MPT64 antigen of the major M. tuberculosis – secreted protein. This is a rapid and reliable test to identify the isolated strains of M. tuberculosis, which is not expensive as conventional biochemical and molecular tests. OBJECTIVE: The objective of the investigation was to evaluate the new immunochromatographic rapid test to identify mycobacteria isolated from respiratory samples from pulmonary TB patients, and referential strains of clinically relevant species of nontuberculous mycobacteria (NTM). MATERIAL AND METHODS: The research was carried out in the period from 1st January, 2010 to 31st December, 2013. It included 43 563 respiratory samples obtained from the patients hospitalized in the Institute for Pulmonary Diseases of Vojvodina, Sremska Kamenica (Serbia). There were 3 469 mycobacterial isolates obtained from the processed respiratory samples. The species – level identification was performed by standard biochemical tests, the molecular test (GenoType®Mycobacterium), and the immunochromatographic test (BD MGIT Tbc). The study included one hundred (100) of Gram positive and Gram negative bacteria (n = 19 species) isolated from respiratory clinical samples. The species – level identification was confirmed by commercial identification systems. RESULTS: During the four – year investigation, 3 469 mycobacterial isolates were obtained from respiratory samples. No declining tendency of mycobacterial isolation was registered in the examined period, as confirmed by the correlation coefficient (r = 0.31). All mycobacterial isolates were identified by conventional biochemical tests showing that 89% of all isolates were identified as M. tuberculosis, and 11% of the isolates as NTM. Mycobacterium xenopi was the most common NTM species identified in 55.3% of the isolates. Following the biochemical identification in 300 M. tuberculosis isolates and 100 NTM isolates, the identification was confirmed by commercially available molecular and immunochromatographic tests. Based on immunochromatographic testing of mycobacteria, the sensitivity, specificity, positive and negative predictive values of the test were 99.7%, 100%, 100% and 99% respectively. There is no statistically significant difference (p> 0.5) when comparing features of immunochromatographic test with conventional biochemical assay. The kappa test value was 0.993, and the confidence interval CI = 0.98 – 1.00. Comparing the immunochromatographic with the molecular test, the kappa value was 0.993, and the confidence interval CI = 0.98 – 1.00. The congruence of the tests findings was also confirmed by the McNemar test, estimated to 0.99. The stability of the secreted MPT64 antigen was registered even five years after the first testing episode. CONCLUSION: The high sensitivity and specificity of the imunochromatographic test enable an accurate and precise identification of M. tuberculosis, as well as a reliable differentiation of M. tuberculosis from NTM. The immunochromatographic test may substitute conventional biochemical and molecular tests to identify M. tuberculosis. It is easier to perform and provides faster test results, thus reducing the time of establishing the diagnosis.</p>
| Identifer | oai:union.ndltd.org:uns.ac.rs/oai:CRISUNS:(BISIS)97492 |
| Date | 01 April 2016 |
| Creators | Savković Tijana |
| Contributors | Hrnjaković-Cvjetković Ivana, Bećarević Mirjana, Milošević Vesna, Nikolić Božana, Suvajdžić Ljiljana, Kuruc Vesna, Lalošević Vesna |
| Publisher | Univerzitet u Novom Sadu, Medicinski fakultet u Novom Sadu, University of Novi Sad, Faculty of Medicine at Novi Sad |
| Source Sets | University of Novi Sad |
| Language | Serbian |
| Detected Language | Unknown |
| Type | PhD thesis |
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