ABSTRACT
In this study,we estimated the application value of detecting Mycobacterium tuberculosis (MTB) specific IgG/IgM antibodies for tuberculosis diagnosis with colloidal gold immunochromatography assay (GICA).We collected 332 effective serum samples and their background information,including 260 patients with tuberculosis and 72 healthy individuals.The means of GICA was used to detect MTB specific IgG/IgM antibodies.Results were compared with the clinical diagnosis and the results of bacteriological tests.The SPSS 22.0 software was used to analyze the results,and when P＜0.05 the difference was statistically significant.The sensitivity and specificity of GICA were 41.15％ and 91.67％,and the sensitivity of the bacterial positive and negative patients were 51.38％ and 33.77％,respectively.The positive rate of IgG/IgM antibodies detection with GICA (41.15％) was much higher than that of bacteria with acid-fast stain of sputum smear (18.84％) and sputum bacteria cultivation (36.15 ％) (P ＜ 0.05) respectively.The positive rate of the combination of tuberculosis antibody detection,sputum bacterial culture and sputum smear was 61.54％,higher than the result of single method or combination of two methods.The detection of specific antibodies against MTB in serum with GICA is sensitive,specific,rapid and convenient,which can be used in clinical screening.Meanwhile,there are still certain limitations of this method,and the sensitivity and specificity need to be improved.Therefore,the GICA can be used as an auxiliary diagnosis combined with sputum bacteriology,imaging test and clinical features rather than diagnose tuberculosis alone.
ABSTRACT
<p><b>OBJECTIVE</b>Macrolide susceptibility and drug resistance mechanisms of clinical non-tuberculous mycobacteria (NTM) isolates were preliminarily investigated for more accurate diagnosis and treatment of the infection in China.</p><p><b>METHODS</b>Four macrolides, including clarithromycin (CLAR), azithromycin (AZM), roxithromycin (ROX), and erythromycin (ERY), were used to test the drug susceptibility of 310 clinical NTM isolates from six provinces of China with the broth microdilution method. Two resistance mechanisms, 23S rRNA and erm, were analyzed with nucleotide sequence analysis.</p><p><b>RESULTS</b>Varied effectiveness of macrolides and species-specific resistance patterns were observed. Most Mycobacterium abscessus subsp. massiliense were susceptible and all M. fortuitum were highly resistant to macrolides. All the drugs, except for erythromycin, exhibited excellent activities against slow-growing mycobacteria, and drug resistance rates were below 22.2%. Only four highly resistant strains harbored 2,058/2,059 substitutions on rrl and none of other mutations were related to macrolide resistance. G2191A and T2221C on rrl were specific for the M. abscessus complex (MABC). Seven sites, G2140A, G2210C, C2217G, T2238C, T2322C, T2404C, and A2406G, were specifically carried by M. avium and M. intracellulare. Three sites, A2192G, T2358G, and A2636G, were observed only in M. fortuitum and one site G2152A was specific for M. gordonae. The genes erm(39) and erm(41) were detected in M. fortuitum and M. abscessus and inducible resistance was observed in relevant sequevar.</p><p><b>CONCLUSION</b>The susceptibility profile of macrolides against NTM was demonstrated. The well-known macrolide resistance mechanisms, 23S rRNA and erm, failed to account for all resistant NTM isolates, and further studies are warranted to investigate macrolide resistance mechanisms in various NTM species.</p>