Tuberculosis is a leading cause of morbidity and mortality worldwide. The aim of this study -was rapid detection of rifampicin resistant mycobacterium tuberculosis (M. TB) strains in pulmonary tuberculous patients by Mycobacterium phage assay fast plaque response™ assay and evaluation ofFDA/EB stain in following up tuberculosis treatment by differentiating between viable and dead M. TB bacilli. Fifty tuberculous patients were subjected to this study and they were chosen according to full history taking, clinical examination and radiological investigations. Microbiological study was done to those patients as follows: early morning sputum sample was collected from each patient and was subjected to staining by Ziehl Neelsen & Flourescin diacetate (FDA)/ Ethidium bromide (EB) stains, culture on Lowenstein-Jensen (L.J) medium and fast plaque TB rifampicin susceptibility assay. The results of this study revealed that out of 50 studied sputum samples from patients under study 42 (84%) were positive for tuberculosis and 8 (16%) were negative for tuberculosis by ZN stain. All 50 studied sputum samples were positive for tuberculosis by FDA/EB stain. Out of 50 FDA/EB stained smears of the studied patients 23 (46%) showed viable bacilli, 4 (8%) showed dead bacilli and 23 (46%) showed both viable and dead bacilli. Out of 50 sputum samples 46 (92%) were positive for tuberculosis by FDA/EB stain and L.J culture, 4 (8%). were negative for tuberculosis by both. The sensitivity and specificity of FDA/EB stain were 100% for both in relation to L.J culture. The results of fast plaque response™ assay of 50 studied sputum samples revealed that 17 (34%) were rifampicin resistant and 33 (66%) rifampicin susceptible. Out of 17 rifampicin resistant cases, 9 (52.9%) had primary rifampicin resistance while 8 (47.1%) had secondary rifampicin resistance. It can be concluded from this study that FDA/EB stain can differentiate between viable and dead M.TB bacilli while ZN can not do that. So FDA/EB stain is useful in follow up of tuberculosis treatment. As the results offastpaque TB RJF™ can be obtained after 48 hours; so it can be considered a rapid method for diagnosis of rifampicin resistant M. TB strain. |
