Detecting Mycobacterium tuberculosis complex and rifampicin resistance via a new rapid multienzyme isothermal point mutation assay.

Simple, rapid, and accurate detection of the Mycobacterium tuberculosis complex (MTBC) and drug resistance is critical for improving patient care and decreasing the spread of tuberculosis. To this end, we have developed a new simple and rapid molecular method, which combines multienzyme isothermal rapid amplification and a lateral flow strip, to detect MTBC and simultaneously detect rifampin (RIF) resistance. Our findings showed that it has sufficient sensitivity and specificity for discriminating 118 MTBC strains from 51 non-tuberculosis mycobacteria strains and 11 of the most common respiratory tract bacteria. Further, compared to drug susceptibility testing, the assay has a sensitivity, specificity, and accuracy of 54.1%, 100.0%, and 75.2%, respectively, for detection of RIF resistance. Some of the advantages of this assay are that no special instrumentation is required, a constant low temperature of 39 °C is sufficient for the reaction, the turnaround time is less than 20 min from the start of the reaction to read out and the result can be seen with the naked eye and does not require specialized training. These characteristics of the new assay make it particularly useful for detecting MTBC and RIF resistance in resource-limited settings.

Management of Persistent Air Leaks Using Endobronchial Autologous Blood Patch and Spigot Occlusion: A Multicentre Randomized Controlled Trial in China.

BACKGROUND: Optimal management of persistent air leaks (PALs) in patients with secondary spontaneous pneumothorax (SSP) remains controversial. OBJECTIVE: To evaluate the efficacy and safety of endobronchial autologous blood plus thrombin patch (ABP) and bronchial occlusion using silicone spigots (BOS) in patients with SSP accompanied by alveolar-pleural fistula (APF) and PALs. METHODS: This prospective multicentre randomized controlled trial compared chest tube-attached water-seal drainage (CTD), ABP, and BOS that were performed between February 2015 and June 2017 in one of six tertiary care hospitals in China. Patients diagnosed with APF experiencing PALs (despite 7 days of CTD) and inoperable patients were included. Outcome measures included success rate of pneumothorax resolution at the end of the observation period (further 14 days), duration of air leak stop, lung expansion, hospital stay, and complications. RESULTS: In total, 150 subjects were analysed in three groups (CTD, ABP, BOS) of 50 each. At 14 days, 60, 82, and 84% of CTD, ABP, and BOS subjects, respectively, experienced full resolution of pneumothorax (p = 0.008). All duration outcome measures were significantly better in the ABP and BOS groups than in the CTD group (p < 0.016 for all). The incidence of adverse events, including chest pain, cough, and fever, was not significantly different. All subjects in the ABP and BOS groups experienced temporary haemoptysis. Spigot displacement occurred in 8% of BOS subjects. CONCLUSION: ABP and BOS resulted in clinically meaningful outcomes, including higher success rate, duration of air leak stop, lung expansion, and hospital stay, with an acceptable safety profile.

Mutations within embCAB Are Associated with Variable Level of Ethambutol Resistance in Mycobacterium tuberculosis Isolates from China.

The EmbCAB proteins have been considered a target for ethambutol (EMB). Mutations in embCAB are known to confer most EMB resistance. However, the knowledge about the effects of embCAB mutations on the EMB resistance level and about the role of mutation-mutation interactions is limited in China. Here, we sequenced embCAB among 125 Mycobacterium tuberculosis isolates from China and quantified their EMB MICs by testing growth at 10 concentrations. Furthermore, a multivariate regression model was established to assess the effects of both individual mutations and multiple mutations. Our results revealed that in China, 82.6% of EMB-resistant isolates (71/86 isolates) harbored at least one mutation within embCAB Most of the mutations were located in the embB and embA upstream region. Several individual mutations and multiple mutations within this region contributed to the different levels of EMB resistance. Their effects were statistically significant. Additionally, there was an association between high-level EMB resistance and multiple mutations.

Comprehensive Analysis of miRNA-mRNA-lncRNA Networks in Non-Smoking and Smoking Patients with Chronic Obstructive Pulmonary Disease.

BACKGROUND/AIMS: Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide. This study aimed to identify overlapping or diverging dysregulated genes, lncRNAs, miRNAs and signaling pathways in smoking and non-smoking chronic obstructive pulmonary disease (COPD). METHODS: Compared to normal controls, we identified the shared and divergent differentially expressed mRNAs (DEmRNAs), miRNAs (DEmiRNAs) and lncRNAs (DElncRNAs) in smoking and non-smoking COPD by RNA-sequencing and bioinformatics analysis. Functional annotation of DEmRNAs were performed. Both cis and trans-target DEmRNAs of DElncRNAs were identified. The target DEmRNAs of DEmiRNAs were identified as well. The DEmiRNA-DEmRNA-DElncRNA interaction network was constructed. QRT-PCR was performed to validat the selected DEmiRNAs, DEmRNA and DElncRNAs in COPD. RESULTS: Compared to normal control, 1234 DEmRNAs, 96 DElncRNAs and 151 DEmiRNAs were identified in non-smoking patients with COPD; 670 DEmRNAs, 44 DElncRNAs and 63 DEmiRNAs were identified in smoking patients with COPD. Leukocyte transendothelial migration and pathways in cancer were significantly enriched pathways in non-smoking and smoking COPD, respectively. MiR-122-5p-A2M-LINC00987/A2M-AS1/ linc0061 interactions might play key roles in COPD irrespective with the smoking status. Let-7-ADRB1-HLA-DQB1-AS1 might play a key role in the pathogenesis of smoking COPD while miR-218-5p/miR15a-RORA-LOC101928100/LINC00861 and miR-218-5p/miR15a-TGFß3-RORA-AS1 interactions might involve with non-smoking COPD. CONCLUSION: We identified the shared and diverging genes, lncRNAs, miRNAs and their interactions and pathways in smoking and non-smoking COPD which provided clues for understanding the mechanism and developing novel diagnostic and therapeutic strategies for COPD.

Rapid detection of rifampin-resistant clinical isolates of Mycobacterium tuberculosis by reverse dot blot hybridization.

OBJECTIVE: A PCR-reverse dot blot hybridization (RDBH) assay was developed for rapid detection of rpoB gene mutations in 'hot mutation region' of Mycobacterium tuberculosis (M. tuberculosis). METHODS: 12 oligonucleotide probes based on the wild-type and mutant genotype rpoB sequences of M. tuberculosis were designed to screen the most frequent wild-type and mutant genotypes for diagnosing RIF resistance. 300 M. tuberculosis clinical isolates were detected by RDBH, conventional drug-susceptibility testing (DST) and DNA sequencing to evaluate the RDBH assay. RESULTS: The sensitivity and specificity of the RDBH assay were 91.2% (165/181) and 98.3% (117/119), respectively, as compared to DST. When compared with DNA sequencing, the accuracy, positive predictive value (PPV) and negative predictive value (NPV) of the RDBH assay were 97.7% (293/300), 98.2% (164/167), and 97.0% (129/133), respectively. Furthermore, the results indicated that the most common mutations were in codons 531 (48.6%), 526 (25.4%), 516 (8.8%), and 511 (6.6%), and the combinative mutation rate was 15 (8.3%). One and two strains of insertion and deletion were found among all strains, respectively. CONCLUSION: Our findings demonstrate that the RDBH assay is a rapid, simple and sensitive method for diagnosing RIF-resistant tuberculosis.

[Serum miRNAs as new biomarkers for esophageal squamous cell carcinoma].

Esophageal squamous cell carcinoma (ESCC) is one of the most common types of malignancies in China. Most ESCC patients are diagnosed at middle to late stages with poor prognosis due to the lack of an effective method for early diagnosis. MicroRNAs (miRNAs) are a family of endogenous small non-coding RNAs that can regulate ESCC development and progression by repressing their specific target genes' expression. Compared to traditional biomarkers (e.g., mRNAs and proteins), miRNAs are more stable and can be readily screened and accurately quantitated and analyzed, making them ideal new-generation of biomarkers for early cancer detection and prognostic evaluation. Recent studies have shown that the changes of the expression levels of some serum miRNAs from ESCC patients significantly correlate with their diagnostic and prognostic outcome. In this review, we summarize the trend of the expression changes of miRNAs in ESCC patients' serum and discuss the possibility of detecting these miRNAs' expression changes as a novel method for ESCC early diagnosis and prognostic evaluation. Notably, the results of serum miRNAs from different detection methods are not completely consistent. Thus, we also discuss several possible reasons for such inconsistency.

Molecular characterization of multidrug-resistant Mycobacterium tuberculosis isolates from China.

To investigate the molecular characterization of multidrug-resistant tuberculosis (MDR-TB) isolates from China and the association of specific mutations conferring drug resistance with strains of different genotypes, we performed spoligotyping and sequenced nine loci (katG, inhA, the oxyR-ahpC intergenic region, rpoB, tlyA, eis, rrs, gyrA, and gyrB) for 128 MDR-TB isolates. Our results showed that 108 isolates (84.4%) were Beijing family strains, 64 (59.3%) of which were identified as modern Beijing strains. Compared with the phenotypic data, the sensitivity and specificity of DNA sequencing were 89.1% and 100.0%, respectively, for isoniazid (INH) resistance, 93.8% and 100.0% for rifampin (RIF) resistance, 60.0% and 99.4% for capreomycin (CAP) resistance, 84.6% and 99.4% for kanamycin (KAN) resistance, and 90.0% and 100.0% for ofloxacin (OFX) resistance. The most prevalent mutations among the MDR-TB isolates were katG315, inhA15, rpoB531, -526, and -516, rrs1401, eis-10, and gyrA94, -90, and -91. Furthermore, there was no association between specific resistance-conferring mutations and the strain genotype. These findings will be helpful for the establishment of rapid molecular diagnostic methods to be implemented in China.

RNA Sequencing and Bioinformatics Analysis to Reveal Potential Biomarkers in Patients with Combined Allergic Rhinitis and Asthma Syndrome.

Introduction: Combined allergic rhinitis and asthma syndrome (CARAS) is a concurrent clinical or subclinical allergic symptom of diseases of the upper and lower respiratory tract. This study is the first to explore the expression profiles of mRNA, lncRNA, and circRNA in CARAS using RNA sequencing, which may provide insight into the mechanisms underlying CARAS. Material and Methods: Whole blood samples from nine participants (three CARAS patients, three AR patients, and three normal control participants) were subjected to perform RNA sequencing, followed by identification of differentially expressed lncRNAs (DElncRNAs), circRNAs (DEcircRNAs) and mRNAs (DEmRNAs). Then, lncRNA/circRNA-mRNA regulatory pairs were constructed, followed by functional analysis, immune infiltration analysis, drug prediction, and expression validation with RT-qPCR and ELISA. Results: The results showed that 61 DEmRNAs, 23 DElncRNAs and 3 DEcircRNAs may be related to the occurrence and development of CARAS. KRT8 may be implicated in the development of AR into CARAS. Three immunity-related mRNAs (IDO1, CYSLTR2, and TEC) and two hypoxia-related mRNAs (TKTL1 and VLDLR) were associated with the occurrence and development of CARAS. TEC may be considered a drug target for Dasatinib in treating CARAS. Several lncRNA/circRNA-mRNA regulatory pairs were identified in CARAS, including LINC00452/MIR4280HG/hsa_circ_0007272/hsa_circ_0070934-CLC, HEATR6-DT/LINC00639/LINC01783/hsa_circ_0008903-TEC, RP11-71L14.3-IDO1/SMPD3, RP11-178F10.2-IDO1/HRH4, and hsa_circ_0008903-CYSLTR2, which may indicate potential regulatory effects of lncRNAs/circRNAs in CARAS. Dysregulated levels of immune cell infiltration may be closely related to CARAS. Conclusion: The regulating effect of lncRNA/circRNA-immunity/hypoxia-related mRNA regulatory pairs may be involved in the occurrence and development of CARAS.

A new multilocus sequence analysis scheme for Mycobacterium tuberculosis.

OBJECTIVE: Tuberculosis remains one of the most serious infectious diseases in the world. In this study, a scheme of Mycobacterium tuberculosis (M. tuberculosis) multilocus sequence analysis (MLSA) was established for the phylogenetic and epidemiology analysis. METHODS: To establish the scheme of M. tuberculosis MLSA, the genome of H37Rv, CCDC5079 and CCDC5180 were compared, and some variable genes were chosen to be the MLSA typing scheme. 44 M. tuberculosis clinical isolates were typed by MLSA, IS6110-RFLP, and soligotyping, to evaluate the MLSA methods. RESULTS: After comparison of the genome, seven high discrimination gene loci (recX, rpsL, rmlC, rpmG1, mprA, gcvH, ideR) were chosen to be the MLSA typing scheme finally. 11 variable SNP sites of those seven genes were found among the 44 M. tuberculosis isolate strains and 11 sequence types (STs) were identified. Based on the Hunter-Gaston Index (HGI), MLSA typing was not as good for discrimination at the strain level as IS6110-RFLP, but the HGI was much better than that of spoligotyping. In addition, the MEGA analysis result of MLSA data was similar to spoligotyping/PGG lineage, showing a strong phylogenetic signal in the modern strains of M. tuberculosis. The MLSA data analysis by eBURST revealed that 4 sequence types (ST) came into a main cluster, showing the major clonal complexes in those 44 strains. CONCLUSION: MLSA genotyping not only can be used for molecular typing, but also is an ideal method for the phylogenetic analysis for M. tuberculosis.

[Efficacy and safety of the combined therapy of valproic acid and lamotrigine for epileptics].

OBJECTIVE: To explore the efficacy and safety of the combined therapy of valproic acid (VPA) and lamotrigine (LTG) for various types of epilepsy. METHODS: The patients were recruited from the epilepsy center at Affiliated Tongji Hospital, Tongji Medical College, Huazhong Science & Technology University from January 2009 to September 2011. They were randomly selected through a number chart and divided into two groups: child group and adult group. The prospective follow-up study lasted for one year to examine the long-term efficacy and safety of combined therapy. Seizure frequency was recorded at Months 3, 6 and 12. The changes of seizure frequency were analyzed to calculate the 50% response rate, 75% response rate and seizure-free rate. All side effects during therapy were recorded. The correlation of efficacy with seizure type was also examined. Statistical analysis was performed through t test, variance analysis and χ(2) test. RESULTS: Among a total of 134 patients, 10 of them withdrew. At Months 3, 6 and 12, as compared with baseline, the average reduction rate of seizure frequency per month was 56%, 62%, 70% in child group versus 74%, 82%, 85% in adult group (P < 0.05). Adult group was better than child group. At Month 3, 50% response rate, 75% response rate and seizure-free rate was 70.97% - 35.48% in child group versus 83.87% - 43.01% in adult group. When compared at Months 3, 6 and 12, 50% response rate, 75% response rate and seizure-free rate showed no statistical difference (P > 0.05). The worse outcomes occurred more frequently in the patients with complex partial seizure (CPS) and than those with simple partial seizure (SPS) and generalized seizure GS (P < 0.05). Rash was the major side effect for withdrawal. CONCLUSION: The co-medication of VPA and LTG is both effective and safe for all epileptic types, especially for SPS and GS. And the efficacy may last for up to one year. Combined therapy shows excellent safety.

rpoB Mutations are Associated with Variable Levels of Rifampin and Rifabutin Resistance in Mycobacterium tuberculosis.

Objective: To assess the relationship between the variant rpoB mutations and the degree of rifampin (RIF)/rifabutin (RFB) resistance in Mycobacterium tuberculosis (M. tuberculosis). Methods: We analyzed the whole rpoB gene in 177 M. tuberculosis clinical isolates and quantified their minimum inhibitory concentrations (MICs) using microplate-based assays. Results: The results revealed that of the 177 isolates, 116 were resistant to both RIF and RFB. There were 38 mutated patterns within the sequenced whole rpoB gene of the 120 isolates. Statistical analysis indicated that mutations, S450L, H445D, H445Y, and H445R, were associated with RIF and RFB resistance. Of these mutations, S450L, H445D, and H445Y were associated with high-level RIF and RFB MIC. H445R was associated with high-level RIF MIC, but not high-level RFB MIC. D435V and L452P were associated with only RIF, but not RFB resistance. Q432K and Q432L were associated with high-level RFB MIC. Several single mutations without statistical association with rifamycin resistance, such as V170F, occurred exclusively in low-level RIF but high-level RFB resistant isolates. Additionally, although cross-resistance to RIF and RFB is common, 21 RIF-resistant/RFB-susceptible isolates were identified. Conclusion: This study highlighted the complexity of rifamycin resistance. Identification of the rpoB polymorphism will be helpful to diagnose the RIF-resistant tuberculosis that has the potential to benefit from a treatment regimen including RFB.

[Pulmonary infection with Mycobacterium massiliense: a case report and review of the literature].

OBJECTIVE: To analyze the clinical features and differential diagnosis of pulmonary infection with Mycobacterium massiliense (M. massiliense). METHODS: The clinical manifestations and laboratory test results of our patient were analyzed and the strain isolated from the patient was tested by bacteriological and molecular methods. The partial gene fragments of rpoB and hsp65 were amplified by PCR, sequenced and compared with GeneBank database in NCBI for identification of Mycobacterium species. RESULTS: The patient was a 72 year old female, who had been admitted to hospital several times because of recurrent respiratory symptoms which had failed to improve upon treatment. This time, pulmonary infection with M. massiliense was confirmed by clinical manifestation and laboratory results. M. massilence isolated from the sputum of our patient was confirmed by bacteriological and molecular methods. The results of specific segments of rpoB and hsp65 tested by PCR and sequence analysis, and compared with that of mycobacterium in NCBI, showed that the DNA homology was 100% and 99% respectively. The results of drug sensitivity test showed that this strain was resistant to multiple drugs. According to the results of drug susceptibility tests and the condition of the patient, therapy with cefoxitin sodium and amikacin was used and the drugs were effective. CONCLUSIONS: The clinical manifestations and the chest imaging of pulmonary infection with M. massiliens were similar to those of Mycobacterium tuberculosis, which can be differentiated by laboratory tests.

Clinical metagenomic sequencing for rapid diagnosis of pneumonia and meningitis caused by Chlamydia psittaci.

BACKGROUND: Chlamydia psittaci (C. psittaci) is a gram-negative intracellular parasitic pathogenic bacterium that can infect avian and mammalian hosts, including humans. The detection of C. psittaci infections typically relies on traditional antigen-based immunoassays or serological testing that often lack sensitivity and/or specificity. Metagenomic next generation sequencing (mNGS) is an emerging tool for diagnosis. AIM: To demonstrate that mNGS represents a valuable tool for rapid, sensitive, and accurate pathogen detection including C. psittaci infections. METHODS: Four cases of psittacosis pneumonia and one case of pediatric psittacosis meningitis were diagnosed between December 2019 and May 2020 using mNGS at Changzhou Second People's Hospital affiliated to Nanjing Medical University. Patients' clinical characteristics, manifestations, and treatment histories were retrospectively evaluated. RESULTS: All five patients had a history of exposure to wild (psittacine or other birds) or domesticated birds (chickens). All patients had a high fever (> 39℃) and three of them (60%) experienced organ insufficiency during the disease. The laboratory data showed normal to slightly increased leucocyte and neutrophil counts, and elevated procalcitonin levels in all five cases, and very high C-reactive protein levels in psittacosis pneumonia patients. mNGS identified a potential pathogen, C. psittaci, in patients' bronchoalveolar lavage fluid or cerebrospinal fluid. Computed tomography revealed lung air-space consolidation, pleural thickening, and effusion fluid buildup in psittacosis pneumonia cases, and an arachnoid cyst in the right temporal lobe of the pediatric psittacosis meningitis patient. All patients experienced complete recovery following the administration of targeted anti-chlamydia therapy. CONCLUSION: This study not only demonstrated that mNGS represents a valuable tool for rapid, sensitive, and accurate pathogen detection, but also raised public health concerns over C. psittaci infections.

rpoB Mutations and Effects on Rifampin Resistance in Mycobacterium tuberculosis.

OBJECTIVE: To investigate the mutations within the whole rpoB gene of Mycobacterium tuberculosis and analyze their effects on rifampin (RIF) resistance based on crystal structure. METHODS: We sequenced the entire rpoB gene in 175 tuberculosis isolates and quantified their minimum inhibitory concentrations using microplate-based assays. Additionally, the structural interactions between wild-type/mutant RpoB and RIF were also analyzed. RESULTS: Results revealed that a total of 34 mutations distributed across 17 different sites within the whole rpoB gene were identified. Of the 34 mutations, 25 could alter the structural interaction between RpoB and RIF and contribute to RIF resistance. Statistical analysis showed that S450L, H445D, H445Y and H445R mutations were associated with high-level RIF resistance, while D435V was associated with moderate-level RIF resistance. CONCLUSION: Some mutations within the rpoB gene could affect the interaction between RpoB and RIF and thus are associated with RIF resistance. These findings could be helpful to design new antibiotics and develop novel diagnostic tools for drug resistance in TB.

LncRNA NEAT1 activates MyD88/NF-κB pathway in bronchopneumonia through targeting miR-155-5p.

BACKGROUND: Bronchopneumonia is a disease of the respiratory tract. It leads to other complications and endangers life and health. Long non-coding RNA (lncRNA) participates in the occurrence and development of bronchopneumonia. Nuclear paraspeckle assembly transcript 1 (NEAT1) plays a key role in inflammatory diseases, but the function of NEAT1 in bronchopneumonia remains unclear. METHODS: RT-qPCR and Western blotting were performed to determine genes and proteins expressions. MTT was applied to test cell viability. Cell apoptosis was detected by flow cytometry. RIP was used to investigate the correlation between NEAT1 and miR-155-5p. The interaction between miR-155-5p and NEAT1 or MyD88 was evaluated by the dual-luciferase reporter gene. RESULTS: NEAT1 and MyD88 were upregulated in BEAS-2B cells by LPS, while miR-155-5p was downregulated. Knockdown of NEAT1 inhibited LPS-induced BEAS-2B cells growth inhibition by inhibiting the apoptosis. In addition, NEAT1 silencing suppressed LPS-induced inflammatory responses in BEAS-2B cells via suppression of TNF-α, IL-1ß, IL-6, and IL-18. Meanwhile, NEAT1 is directly bound to miR-155-5p to regulate MyD88/NF-κB axis, and overexpression of miR-155-5p increased cell proliferation and suppressed inflammatory factors expression levels and cell apoptosis. Furthermore, sh-NEAT1-induced inhibition of BEAS-2B cells injury was partially reversed by miR-155-5p inhibitor or MyD88 overexpression. CONCLUSION: NEAT1 silencing suppressed LPS-induced BEAS-2B cells injury and inflammation by the mediation of miR-155-5p/MyD88/NF-κB axis. Thus, our study might shed new light on exploring the new strategies for the treatment of bronchopneumonia.

Accuracy of a reverse dot blot hybridization assay for simultaneous detection of the resistance of four anti-tuberculosis drugs in Mycobacterium tuberculosis isolated from China.

BACKGROUND: Drug resistant tuberculosis poses a great challenge for tuberculosis control worldwide. Timely determination of drug resistance and effective individual treatment are essential for blocking the transmission of drug resistant Mycobacterium tuberculosis. We aimed to establish and evaluate the accuracy of a reverse dot blot hybridization (RDBH) assay to simultaneously detect the resistance of four anti-tuberculosis drugs in M. tuberculosis isolated in China. METHODS: In this study, we applied a RDBH assay to simultaneously detect the resistance of rifampicin (RIF), isoniazid (INH), streptomycin (SM) and ethambutol (EMB) in 320 clinical M. tuberculosis isolates and compared the results to that from phenotypic drug susceptibility testing (DST) and sequencing. The RDBH assay was designed to test up to 42 samples at a time. Pearson's chi-square test was used to compute the statistical measures of the RDBH assay using the phenotypic DST or sequencing as the gold standard method, and Kappa identity test was used to determine the consistency between the RDBH assay and the phenotypic DST or sequencing. RESULTS: The results showed that the concordances between phenotypic DST and RDBH assay were 95% for RIF, 92.8% for INH, 84.7% for SM, 77.2% for EMB and the concordances between sequencing and RDBH assay were 97.8% for RIF, 98.8% for INH, 99.1% for SM, 93.4% for EMB. Compared to the phenotypic DST results, the sensitivity and specificity of the RDBH assay for resistance detection were 92.4 and 98.5% for RIF, 90.3 and 97.3% for INH, 77.4 and 91.5% for SM, 61.4 and 85.7% for EMB, respectively; compared to sequencing, the sensitivity and specificity of the RDBH assay were 97.7 and 97.9% for RIF, 97.9 and 100.0% for INH, 97.8 and 100.0% for SM, 82.6 and 99.1% for EMB, respectively. The turnaround time of the RDBH assay was 7 h for testing 42 samples. CONCLUSIONS: Our data suggested that the RDBH assay could serve as a rapid and efficient method for testing the resistance of M. tuberculosis against RIF, INH, SM and EMB, enabling early administration of appropriate treatment regimens to the affected drug resistant tuberculosis patients.

Detecting Ethambutol Resistance in Mycobacterium tuberculosis Isolates in China: A Comparison Between Phenotypic Drug Susceptibility Testing Methods and DNA Sequencing of embAB.

With the increasing incidence of drug-resistant tuberculosis (DR-TB), determining a rapid and accurate drug susceptibility testing (DST) method to identify ethambutol (EMB) resistance in Mycobacterium tuberculosis has become essential for patient management in China. Herein, we evaluated the correlation between three phenotypic DST methods, namely, proportion method (PM), MGIT 960 system, and microplate alamar Blue assay (MABA), and DNA sequencing of embAB in 118 M. tuberculosis isolates from China. When the results of the phenotypic DST methods were compared with those of DNA sequencing, the overall agreement and kappa values of the PM, MGIT 960 system, and MABA were 81.4% and 0.61, 77.1% and 0.55, and 84.7% and 0.67, respectively. The agreement for EMB resistance between MABA and PM was significantly higher than that between the MGIT 960 system and PM (P = 0.02). Moreover, among the isolates with detectable embAB mutations, 97.2% (70/72 isolates) harbored mutations in embB. The analysis of embB mutations predicted EMB resistance with 81.3% sensitivity, 86.8% specificity, and 83.1% accuracy. Thus, MABA may be a better phenotypic DST method for detecting EMB resistance. DNA sequencing of embB may be useful for the early identification of EMB resistance and the consequent optimization of the treatment regimen.

[Brain injury in adenosine A1 receptor knock-out mice after pentetrazole kindling and its correlation with COX-2].

OBJECTIVE: To investigate the brain injury of neurocytes in hippocampus of adenosine A1 receptor knock-out mice during pentetrazole kindling and detect the correlation of brain injury and the expression of COX-2 so as to evaluate the neuroprotective function of adenosine A1 receptor and its mechanism. METHODS: The animals were divided into two groups: wild type group and KO group. The kindling model was established by injection of pentetrazole into abdominal cavity. The expression of brain injury related protein, caspase-3 and COX-2 in hippocampus was investigated separately at different time points (24 hour, 1 month) post-kindling. RESULTS: The expression of Caspase-3 and COX-2 increased in KO group both during acute and chronic phases post-kindling compared with normal mice. There was statistical difference (P < 0.05). Furthermore, the expression levels of two proteins were higher at 1 month compared with 24 hour (P < 0.01). These results indicated that the increased expression of Caspase-3 and COX-2 post-kindling was earlier and much more in KO mice as compared with wild-type ones. CONCLUSION: Adenosine exerts strong neuroprotective functions through the activation of adenosine A1 receptor. This receptor reduces cell apoptosis during pentetrazole kindling. Cyclooxygenase-2 (COX-2) reflects the extent of brain injury. The neuroprotective function mediated by adenosine A1 receptor might be related with COX-2.

[Comparison on discriminatory power of different variable number tandem repeats locus-set on genotyping of mycobacterium tuberculosis isolated in China].

OBJECTIVE: To evaluate the application of different variable number tandem repeats (VNTR) locus in genotyping of Mycobacterium tuberculosis (M.tuberculosis) strains isolated from eight provinces in China, and to find the suitable locus-set of VNTR for epidemical strains in China. METHODS: All 140 M.tuberculosis strains were randomly selected from 2800 M.tuberculosis strains isolated from eight provinces in China, 27 VNTR loci were used for typing all isolates. Discriminatory power (Hunter-Gaston Index, HGI) of every locus and different locus-set were analyzed by BioNumerics software. Meanwhile, Spoligotyping was used to identify Beijing family and non-Beijing family. Then the HGI of different locus-sets in two families was also evaluated. RESULTS: All 140 isolates were clustered into Beijing kindred (112 strains, 80%) and non-Beijing kindred (28 strains, 20%) by Spoligotyping. The discriminatory power of Spoligotyping in 140 isolates was 0.4589. Every locus showed different polymorphism and HGI were from 0 to 0.809. The number of VNTR loci with HGI higher than 0.5 in all strains, Beijing family and non-Beijing family was 8, 7 and 14 respectively. 27 loci were combined into four groups which included 8, 12, 15 and 24 VNTR loci respectively. Four locus-sets showed different polymorphism, HGI of eight-locus, 12-locus, 15-locus, and 24-locus set in 140 strains was 0.9991, 0.9882, 0.9980 and 0.9986, and their discriminatory power were calculated in Beijing kindred (HGI: 0.9987, 0.9318, 0.9969 and 0.9975) and non-Beijing kindred (HGI: 1, 0.9894, 1 and 1). CONCLUSION: Different VNTR locus and locus-set showed different discriminatory power in the selected M.tuberculosis strains isolated from China. Eight-locus set can be used in molecular epidemiological study of M.tuberculosis in China after standardization.

[Effects of temperature and phosphorus application on wheat growth at seedling stage and phosphorus form in calcareous fluvo-aquic soil]. / 温度和施磷对石灰性潮土小麦苗期生长及磷形态的影响.

The effects of temperature and phosphate fertilizer application on wheat seedling growth and soil inorganic phosphorus transformation in calcareous fluvo-aquic soil were examined in a pot experiment. The results showed that temperature and phosphorus were important factors affecting wheat growth but without significant interaction. The effect of temperature on wheat growth was greater than that of phosphate fertilizer, and 15 ℃ was the suitable temperature for wheat seedling. Compared with the treatment without P application (-P) at 5 ℃, phosphate fertilizer treatment (+P) promoted the growth of wheat seedling. Shoot and root biomass increased by 18.2% and 33.3%, the accumulation of phosphorus in shoot and root were increased by 30.6% and 13.3%, and the root-shoot ratio, plant height, tillering number and root activity were increased by 3.5%, 10.0%, 10.5% and 70.3%, respectively. At 15 ℃, the effect of phosphorus fertilizer application did not affect wheat biomass and tiller, increased P accumulation in shoot and root of wheat by 32.3% and 23.8%, and increased the ratio of root to shoot, plant height and root activity by 15.6%, 2.5% and 32.8% respectively. There were no significant promoting effects on wheat growth between different phosphate applications at 25 ℃. At three temperatures, phosphate application significantly increased the contents of Olsen-P, Ca2-P, Ca8-P, Al-P and Fe-P. When treated with -P and +P, temperature had no significant effect on Ca2-P content, but had significant effect on the Olsen-P, Ca8-P, Al-P, Fe-P contents. The contents of Ca8-P and Fe-P were 5 ℃＞15 ℃＞25 ℃; Al-P content was 25 ℃＞15 ℃＞5 ℃. Wheat could absorb and utilize Ca2-P, Ca8-P, Al-P, Fe-P at seedling stage. The availability of Al-P, Fe-P to wheat was significantly lower than that of Ca2-P, Ca8-P. There was no significant difference of soil pH, O-P and Ca10-P across all treatments. In conclusion, temperature mainly affected the absorption of phosphorus by affecting wheat growth, and the application of phosphorus fertilizer at low temperature could significantly promote the growth of wheat. High temperature could accelerate the fixation of available phosphorus in calcareous soil, a process could be alleviated by phosphorus application.