Application of real-time simultaneous amplification and testing method to accurately and rapidly detect extra-pulmonary tuberculosis.

BACKGROUND: This study aimed to establish and evaluate a simultaneous amplification and testing method for detection of extra-pulmonary tuberculosis (EPTB). METHODS: From January 2016 and December 2017 the pus or surgical excision from the lesions of inpatients admitted from Chongqing Public Health Treatment Center were collected. According to the clinical diagnosis, the samples were divided into two groups including EPTB (Group A) and other diseases excluded from tuberculosis diseases (Group B). Simultaneous detection of Mycobacterium tuberculosis (MTB) used Roche culture method, liquid culture method and simultaneous amplification and testing (SAT) method. The sensitivity and specificity of the SAT method were compared with culture methods and clinical diagnosis of EPTB. RESULTS: For 433 EPTB specimens and 49 non-TB specimens, the simultaneous amplification and testing tuberculosis (SAT-TB) results correlated with 80.5% (388/482 specimens) of the culture assay results. The sensitivity, specificity, and positive and negative predictive values of the SAT-TB test for the diagnosis of EPTB were 83.6, 79.4, 59.4, and 93.0%, respectively, compared to culture methods. Compared with the clinical diagnosis of patients, the sensitivity and specificity of the SAT-TB test were 41.6 and 100%, respectively, the cultures test were 29.3 and 98.0%. CONCLUSIONS: SAT test is a simple and rapid test with high specificity which may enhance the detection of EPTB. SAT-TB is a higher clinical diagnosis value for EPTB in clinical microbiology laboratories.

The Chinese ACL injury population has a higher proportion of small ACL tibial insertion sizes than Western patients.

PURPOSE: The study purpose is to characterize the sizes of the anterior cruciate ligament (ACL) insertion site and intercondylar notch in Chinese patients undergoing ACL surgery. The findings will provide a reference for individualized clinical treatment of ACL rupture. METHODS: For this study, 137 patients (102 males, 35 females) with an average age of 30.3 ± 9.5 years (range 14-52 years) undergoing ACL reconstruction were included. The tibial ACL insertion site length and width and the intercondylar notch width were measured on MRI and arthroscopically using a ruler. Descriptive statistics of the patients, the distribution of the measurements and the differences between males and females were calculated. RESULTS: The ACL tibial insertion size and intercondylar notch width in Chinese patients with ACL injuries, as obtained by MRI and intra-operatively, exhibited significant individual variability. The tibial ACL insertion site had a mean length of 13.5 ± 2.1 mm and width of 10.9 ± 1.5 mm as measured on MRI and a mean length of 13.3 ± 2.1 mm and width of 11.0 ± 1.6 mm as measured intra-operatively. The mean intercondylar notch width was 15.2 ± 2.4 mm on MRI and the mean length was 15.0 ± 2.5 mm intra-operatively. The inter-rater reliability between MRI and intra-operative measurements confirmed that the two methods were consistent. In 65.7% of individuals, the ACL tibial insertion length was < 14 mm. CONCLUSION: The distribution of tibial footprint size in Chinese patients is different from that in Western populations. There is a higher proportion of subjects with a tibial footprint size < 14 mm among Chinese patients with ACL injury. Therefore, great care should be taken when treating this population with the double-bundle technique or larger graft options. Level of evidence IV.

Could high-concentration rifampicin kill rifampicin-resistant M. tuberculosis? Rifampicin MIC test in rifampicin-resistant isolates from patients with osteoarticular tuberculosis.

PURPOSE: Several studies have shown that the intralesional concentration of rifampicin in osteoarticular tuberculosis is typically at a subtherapeutic level. Sustained or controlled release by novel drug delivery systems has been investigated to maintain an effective rifampicin concentration, but the local administration of rifampicin remains controversial. Additionally, it is still unclear whether high-dose rifampicin could kill rifampicin-resistant Mycobacterium tuberculosis. The aim of this study was to assess the in vitro killing effect of high-concentration rifampicin on rifampicin-resistant M. tuberculosis isolated from patients with osteoarticular tuberculosis. METHODS: A set of 18 rifampicin-resistant M. tuberculosis isolates by the BACT/MGIT 960 system from patients with osteoarticular tuberculosis was collected for further study. The detection of rpoB gene mutations was performed using non-fluorescent, low-density DNA microarrays to determine the resistant mechanism. Following secondary culture, susceptibility to gradient concentrations of rifampicin (2 to 256 µg/ml) was tested; these concentrations are attainable for prolonged periods of local chemotherapy. The relationship between microbial killing by high-dose rifampicin and rpoB gene mutations was analyzed. RESULTS: Mutations in the rifampicin resistance-determining region (RRDR) of the rpoB gene were identified in 17 isolates (94.4%); one strain exhibited no mutations in this region. The most prevalent mutation sites were in codons 531 (55.56%), 516 (16.67%), 526 (11.11%), and 513 (11.11%). Isolates with mutations in the rpoB gene were highly resistant to rifampicin, 11 of which had minimal inhibitory concentrations (MICs) exceeding 256 µg/ml (not determined). The MICs for the remaining seven resistant isolates were between 32 and 256 µg/ml. Particularly in less rifampicin-resistant M. tuberculosis strains, growth was inhibited at high concentrations. CONCLUSION: Increasing the rifampicin concentration may optimize this drug's antituberculous effect, even against some rifampicin-resistant isolates, if systemic and local toxic effects can be minimized.