ABSTRACT
Objective To improve the diagnosis of tuberculosis ( TB) by analyzing Mycobacterium infection in fine-needle aspiration biopsy specimens from children with tuberculous lymphadenitis .Methods Fine-needle aspiration biopsy was performed on 269 children with tuberculous lymphadenitis diagnosed by Shanghai Public Health Clinical Center from January 2011 to September 2013 .The needle aspiration biopsy specimens were processed for acid-fast bacillus (AFB) smear test, mycobacterial culture and Mycobacterium identification ( p-nitrobenzoic acid inhibition test ) .Results Cytological diagnosis of tuberculous lymphade-nitis was made for 269 patients.The positive results by AFB smear test were detected in 63.19% of 269 specimens (n=170) and 40.15%(n=108) specimens were positive in mycobacterial culture .The differ-ence between the two tests were significant (P<0.01).The positive rate of Mycobacterium detected by using BACTEC MGIT 960 automated system and L?wenstein-Jensen culture method were 38 .66% ( n=104 ) and 28.99%(n=78), respectively, showing the significant difference between two tests (P<0.05).AFB smear test in combination with mycobacterial culture could precisely diagnose 70.63% of tuberculous lym-phadenitis in children.Of the 108 clinical isolates, 105 strains (97.2%) were Mycobacterium tuberculosis complex and the rest were non-tuberculous Mycobacterium strains (2.8%).Conclusion The positive rate by AFB smear test was significantly increased in fine needle aspiration biopsy specimens after a series of treatments including sample digestion , centrifugation and precipitation , but the positive rate of mycobacterial culture was reduced .Diagnostic accuracy could be significantly improved by using BACTEC MGIT 960 sys-tem.Mycobacterium tuberculosis complex was the predominant pathogenic bacterium in children with tubercu-lous lymphadenitis .
ABSTRACT
Objective: Drug resistant tuberculosis has long been a common problem prevailing in developing countries including Bangladesh. Present study focused on the rapid identification of live Mycobacterium tuberculosis among treatment failure cases. Materials and Methods: Sputum samples from a total of 100 category-I and category-II treatment failure cases, assumed as multidrug resistant tuberculosis, were studied through fluorescein diacetate (FDA) staining under light emitting diode (LED) fluorescence microscope. Considering culture method as gold standard, we also compared the results of FDA staining with that of auramine O staining. Results: A total of 85% acid-fast bacilli were detected by FDA staining, 82% by auramine O staining and a total of 85% isolates were detected in Lowenstein-Jensen (LJ) culture. The sensitivity of FDA staining (96.47%) was estimated to be slightly higher than that of auramine O staining (91.76%). Moreover, 76.47% cases were detected as multidrug resistant tuberculosis (MDR-TB). Conclusion: Taken together, FDA staining method has been proposed to be appropriate for the rapid diagnosis of drug resistant tuberculosis.