Insight into Population Structure and Drug Resistance of Pediatric Tuberculosis Strains from China and Russia Gained through Whole-Genome Sequencing.

This study aimed to determine phenotypic and genotypic drug resistance patterns of Mycobacterium tuberculosis strains from children with tuberculosis (TB) in China and Russia, two high-burden countries for multi/extensively-drug resistant (MDR/XDR) TB. Whole-genome sequencing data of M. tuberculosis isolates from China (n = 137) and Russia (n = 60) were analyzed for phylogenetic markers and drug-resistance mutations, followed by comparison with phenotypic susceptibility data. The Beijing genotype was detected in 126 Chinese and 50 Russian isolates. The Euro-American lineage was detected in 10 Russian and 11 Chinese isolates. In the Russian collection, the Beijing genotype and Beijing B0/W148-cluster were dominated by MDR strains (68% and 94%, respectively). Ninety percent of B0/W148 strains were phenotypically pre-XDR. In the Chinese collection, neither of the Beijing sublineages was associated with MDR/pre-XDR status. MDR was mostly caused by low fitness cost mutations (rpoB S450L, katG S315T, rpsL K43R). Chinese rifampicin-resistant strains demonstrated a higher diversity of resistance mutations than Russian isolates (p = 0.003). The rifampicin and isoniazid resistance compensatory mutations were detected in some MDR strains, but they were not widespread. The molecular mechanisms of M. tuberculosis adaptation to anti-TB treatment are not unique to the pediatric strains, but they reflect the general situation with TB in Russia and China.

The clinical significance of macrolide resistance in pediatric Mycoplasma pneumoniae infection during COVID-19 pandemic.

Background: Mycoplasma pneumoniae (MP) is a commonly occurring pathogen causing community-acquired pneumonia (CAP) in children. The global prevalence of macrolide-resistant MP (MRMP) infection, especially in Asian regions, is increasing rapidly. However, the prevalence of MRMP and its clinical significance during the COVID-19 pandemic is not clear. Methods: This study enrolled children with molecularly confirmed macrolide-susceptible MP (MSMP) and MRMP CAP from Beijing Children's Hospital Baoding Hospital, Capital Medical University between August 2021 and July 2022. The clinical characteristics, laboratory findings, chest imaging presentations, and strain genotypes were compared between patients with MSMP and MRMP CAP. Results: A total of 520 hospitalized children with MP-CAP were enrolled in the study, with a macrolide resistance rate of 92.7%. Patients with MRMP infection exhibited more severe clinical manifestations (such as dyspnea and pleural effusion) and had a longer hospital stay than the MSMP group. Furthermore, abnormal blood test results (including increased LDH and D-dimer) were more common in the MRMP group (P<0.05). Multilocus variable-number tandem-repeat analysis (MLVA) was performed on 304 samples based on four loci (Mpn13-16), and M3562 and M4572 were the major types, accounting for 74.0% and 16.8% of the strains, respectively. The macrolide resistance rate of M3562 strains was up to 95.1%. Conclusion: The prevalence of MRMP strains in hospitalized CAP patients was extremely high in the Baoding area, and patients infected with MRMP strains exhibited more severe clinical features and increased LDH and D-dimer. M3562 was the predominant resistant clone.

Registration of intervention trials of Traditional Chinese Medicine for four neurological diseases on Chinese Clinical Trial Registry and ClinicalTrials.gov: a narrative review.

OBJECTIVE: To analyze the current status of clinical trial registration of Traditional Chinese Medicine (TCM) for the treatment of neurological diseases. METHODS: Interventional clinical trials of TCM treatment for ischemic stroke, hemorrhagic stroke, vascular cognitive impairment, tension-type headache before September 22, 2020 on the platform of Chinese Clinical Trial Registry (ChiCTR), and ClinicalTrials.gov were searched. Two researchers independently selected the literature and extracted data. RESULTS: A total of 180 interventional clinical trials were included for analysis. Out of 180 trials, 127 were from ChiCTR and 53 from ClinicalTrials.gov. The countries primary sponsoring the included trials were China (176, 97.8%), and the common categories of primary sponsors were hospital (131, 72.8%). Among the study design, the largest proportion of allocation was randomized (172, 95.6%), interventional model assignment was parallel (163, 90.6%), masking was double blind 49 (27.2%), and the sample size was ≤ 400 (144, 80.0%). The trials were most carried out at a single center (102, 56.7%). Among the included studies, 112 (62.2%) registered on ChiCTR attached the ethical approval documents. In terms of trial stages, 50 (27.7%) studies were in phase IV. The mostly used intervention was Chinese herbal medicines (99, 55%), acupuncture (68, 37.8%) was the second. By searching the registration number on China National Knowledge Infrastructure Database and PubMed, 38 (21.1%) registered trials were published, including 25 protocol studies and 14 research results with one (NCT02275949) published both the protocol and the results. CONCLUSIONS: Irregular and inadequate reporting, untimely update and publication, insufficient information on traditional medicine unique characteristics, and lack of international collaborations are the problems existing in the interventional clinical registration trials of traditional medicine treatment on neurological diseases. More efforts need to be made from the above aspects to standardize and improve the registration of traditional medicine trials.

[Situation analysis of outcome indicators of randomized controlled trials of traditional Chinese medicine in treatment of hypertensive intracerebral hemorrhage in recent three years].

The study aims to analyze the outcome indicators of randomized controlled trial(RCT) of traditional Chinese medicine(TCM) in the treatment of hypertensive intracerebral hemorrhage(HICH) in recent three years, and thus provide suggestions for the future studies in this field. Four English databases, four Chinese databases and two online registration websites of clinical trials were searched. The RCTs published between January 2018 and September 2020 were screened. The risk of bias was assessed and outcome measures were classified. A total of 151 839 articles were retrieved, of which 44 RCTs were included for analysis after screening. The outcome measures of the included RCTs were classified into 7 categories, among which the symptoms/signs category showed the highest reporting rate. National Institute of Health stroke scale(72.73%) was the most frequently reported outcome indicator, while the vo-lume of intracerebral hemorrhage determined by computerized tomography(36.36%) was the most frequently reported lab test outcome. Most studies collect the outcomes at the end of treatment, while 9 studies reported long-term outcomes 3 months or more after onset. Compared with those of international clinical trials, the application of some of the outcomes was reasonable, focusing on patients' symptoms, quality of life and objective outcomes. However, there were still several problems: unclear primary and secondary outcome measures, insufficient attention to long-term prognosis, insufficient attention to social function, few TCM outcomes, lack of measurement blindness and the use of unreasonable composite outcomes. It is recommended that researchers should rationally design the outcome indicators of clinical trials and develop the core outcome set.

[Overview of systematic reviews/Meta-analysis of Xingnaojing Injection in treatment of intracerebral hemorrhage].

To overview of systematic reviews/Meta-analysis of Xingnaojing Injection(XNJ) in the treatment of intracerebral hemorrhage(ICH). The systematic reviews concerning XNJ in the treatment of ICH were retrieved from four Chinese databases, four English databases, Chinese Clinical Trial Registry and ClinicalTrail.gov, with the retrieval time set from their inception to September 2020. Following the independent screening and data extraction by two researchers, a measurement tool to assess systematic evaluation 2(AMSTAR 2) and grades of recommendation, assessment, development and evaluation(GRADE) system were used to evaluate the metho-dological, reporting and evidence qualities of the 10 included systematic reviews. The results showed that XNJ was superior to the wes-tern medicine or conventional treatment in improving the effective rate and National Institutes of Health stroke scale(NIHSS) score, Barthel index(BI), and Glasgow coma scale(GCS) score and Chinese stroke scale(CSS) score, and reducing the mortality and cerebral hematoma volume, without inducing obvious adverse reactions. In general, the methodological, reporting and evidence qualities of the 10 included systematic reviews were poor. The AMSTAR 2 scores showed that key items No. 2 and No. 16 failed to meet the stan-dard, resulting in poor methodological quality. There was only one outcome indicator graded by GRADE as intermediate quality, 43% indicators as low quality, 42% indicators as extremely low quality, and none as high quality. These available evidences have suggested that the methodological, reporting and evidence qualities of the systematic evaluation concerning XNJ for the treatment of ICH need to be improved. Most evidences support that XNJ was better than the western medicine or conventional treatment in the treatment of ICH, but the methodological quality and the reliability of outcome indicators in relevant systematic review were low. More high-quality studies are still required for further verification.

[Systematic review and Meta-analysis of efficacy and safety of acupuncture therapy on hypertensive intracerebral hemorrhage].

To systematically review the efficacy and safety of acupuncture combined with minimally invasive surgery or basic the-rapy in treating hypertensive intracerebral hemorrhage(HICH) patients compared with minimally invasive surgery or basic treatment. In this study, the four Chinese databases, the four English databases, Chinese Clinical Trial Registry and ClinicalTrail.gov, all above were systematically and comprehensively retrieved from the time of database establishment to September 10, 2020. Rando-mized controlled trials(RCTs) were screened out according to inclusion criteria and exclusion criteria established in advanced. The methodological quality of included studies was evaluated by the tool named "Cochrane bias risk assessment 6.1". Meta-analysis of the included studies was performed using RevMan 5.4, and the quality of outcome indicators was evaluated by the GRADE system. Finally, 17 studies were included, involving 1 852 patients with HICH, and the overall quality of the included studies was not high. According to Meta-analysis,(1)CSS score of the group of acupuncture combined with minimally invasive surgery or basic therapy was superior to the group of minimally invasive surgery or basic therapy(MD=-3.50,95%CI[-4.39,-2.61],P<0.000 01);(2)NIHSS score of the group of acupuncture combined with minimally invasive surgery or basic therapy was superior to the group of minimally invasive surgery or basic therapy(MD=-4.78,95%CI[-5.55,-4.00],P<0.000 01);(3)the cerebral hematoma volume of the group of acupuncture combined with minimally invasive surgery or basic therapy was superior to the group of minimally invasive surgery or basic therapy(MD=-4.44,95%CI[-5.83,-3.04],P<0.000 01);(4)ADL score of the group of acupuncture combined with minimally invasive surgery or basic therapy was superior to the group of minimally invasive surgery or basic therapy(MD=20.81,95%CI[17.25,24.37],P<0.000 01);(5)the GCS score of the group of acupuncture combined with minimally invasive surgery or basic therapy was superior to the group of minimally invasive surgery or basic therapy(MD=2.41,95%CI[1.90,2.91],P<0.000 01). The GRADE system showed an extremely low level of evidence for the above outcome indicators. Adverse reactions were mentioned only in two literatures, with no adverse reactions reported. The available evidence showed that acupuncture combined with minimally invasive surgery or basic therapy had a certain efficacy in patients of HICH compared with minimally invasive surgery or basic therapy. However, due to the high risk of bias in the included studies, its true efficacy needs to be verified by more high-quality studies in the future.

[Systematic review and Meta-analysis on efficacy and safety of Naoxueshu Oral Liquid in treatment of hypertensive intracerebral hemorrhage].

To systematically review the efficacy and safety of Naoxueshu Oral Liquid in treatment of hypertensive intracerebral hemorrhage, four Chinese databases, four English databases, clinical trials registration center(ClinicalTrials.gov) and Chinese clinical trial registry were retrieved. The retrieval time was from the establishment of each database to September 9, 2020. According to the set criteria, the randomized controlled trial(RCT) of Naoxueshu Oral Liquid combined with conventional Western medicine was selected. The "Cochrane bias risk assessment" tool was used to evaluate the quality of the included studies. RevMan 5.4.1 was used to conduct Meta-analysis of the included studies and GRADE system was used to evaluate the evidence quality of the outcome indicators. Eleven studies were finally included, with a total sample size of 1 221 cases, 612 cases in the treatment group and 609 cases in the control group. Meta-analysis showed that Naoxueshu Oral Liquid combined with conventional Western medicine had no significant difference compare with conventional Western medicine in reducing National Institute of health stroke scale(NIHSS) after 2 weeks of treatment for hypertensive intracerebral hemorrhage(MD=-1.59,95%CI[-3.46,0.29],P=0.10), but was superior to conventional Western medicine after 30 d of treatment(MD=-1.16,95%CI [-1.39,-0.94],P<0.000 01). Naoxueshu Oral Liquid combined with conventional Western medicine was superior to conventional Western medicine in improving Glasgow coma scale(MD=1.00,95%CI[0,2.00],P=0.05) and reducing the incidence of secondary brain insults(RR=0.38,95%CI[0.24,0.59],P<0.000 1), but there was no significant difference in increasing Barthel index(MD=1.00,95%CI[-0.30,2.30],P=0.13). In terms of effective rate, studies using Guideline for clinical trials of new patent Chinese medicines, NHISS or Glasgow outcome scale(GOS) had shown that Naoxueshu Oral Liquid combined with conventional Western medicine was superior to conventional Western medicine(RR_(Guideline for clinical trials of new patent Chinese medicines)=1.27,95%CI[1.10,1.46],P=0.001;RR_(NHISS)=1.26,95%CI[1.13,1.40],P<0.000 1;RR_(GOS)=1.54,95%CI[1.22,1.93],P=0.000 2). In reduction of hematoma volume, Naoxueshu Oral Liquid combined with conventional Western medicine was superior to conventional Western medicine after 2 and 4 weeks of treatment(MD_(2 week)=-2.31,95%CI[-3.12,-1.49],P<0.000 01;MD_(4 week)=-2.04,95%CI[-2.41,-1.68],P<0.000 01). GRADE system showed that the evidence level of the above outcome indicators was low and extremely low. In terms of adverse reactions, two of the included studies reported mild adverse reactions, and the rest of studies were not mentioned, so this study was not able to make a positive evaluation of the safety of Naoxueshu Oral Liquid. This study showed that compared with conventional Western medicine, combined Naoxueshu Oral Liquid may be better for hypertensive intracerebral hemorrhage. However, due to the high bias risk in the included studies, more large-sample and high-quality RCTs are still needed in the future.

Population pharmacokinetics-pharmacodynamics of ceftazidime in neonates and young infants: Dosing optimization for neonatal sepsis.

Ceftazidime is a third-generation cephalosporin with high activity against many pathogens. But the ambiguity and diversity of the dosing regimens in neonates and young infants impair access to effective treatment. Thus, we conducted a population pharmacokinetic study of ceftazidime in this vulnerable population and recommended a model-based dosage regimen to optimize sepsis therapy. Totally 146 neonates and young infants (gestational age (GA): 36-43.4 weeks, postnatal age (PNA): 1-81 days, current weight (CW): 900-4500 g) were enrolled based on inclusion and exclusion criteria. Ceftazidime bloods samples (203) were obtained using the opportunistic sampling strategy and determined by the high-performance liquid chromatography. The population pharmacokinetic-pharmacodynamic analysis was conducted by nonlinear mixed effects model (NONMEM). A one-compartment model with first-order elimination best described the pharmacokinetic data. Covariate analysis showed the significance of GA, PNA, and CW on developmental pharmacokinetics. Monte Carlo simulation was performed based on above covariates and minimum inhibitory concentration (MIC). In the newborns with PNA ≤ 3 days (MIC=8 mg/L), the dose regimen was 25 mg/kg twice daily (BID). For the newborns with PNA > 3 days (MIC=16 mg/L), the optimal dose was 30 mg/kg three times daily (TID) for those with GA ≤ 37 weeks and 40 mg/kg TID for those with GA > 37 weeks. Overall, on the basis of the developmental population pharmacokinetic-pharmacodynamic analysis covering the whole range of neonates and young infants, the evidence-based ceftazidime dosage regimens were proposed to optimize neonatal early-onset and late-onset sepsis therapy.

Multiple Cross Displacement Amplification Combined With Real-Time Polymerase Chain Reaction Platform: A Rapid, Sensitive Method to Detect Mycobacterium tuberculosis.

In this study, we evaluated the diagnostic accuracy of multiple cross displacement amplification (MCDA) combined with real-time PCR platform in pulmonary tuberculosis (PTB) patients. Total 228 PTB patients and 141 non-TB cases were enrolled. Based on the analysis of the first available sample of all participants, MCDA assay showed a higher overall sensitivity (64.0%), with a difference of more than 10% compared with Xpert MTB/RIF (Xpert) assay (51.8%, P < 0.05) and combined liquid and solid culture (47.8%, P < 0.001) for PTB diagnosis. In particular, MCDA assay detected 31 probable TB patients, which notably increased the percentage of confirmed TB from 57.9% (132/228) to 71.5% (163/228). The specificities of microscopy, culture, Xpert and MCDA assay were 100% (141/141), 100% (141/141), 100% (141/141), and 98.6% (139/141), respectively. Among the patients with multiple samples, per patient sensitivity of MCDA assay was 60.5% (52/86) when only the first available sputum sample was taken into account, and the sensitivity increased to 75.6% (65/86) when all samples tested by MCDA assay were included into the analysis. Therefore, MCDA assay established in this study is rapid, accurate and affordable, which has the potential in assisting the accurate and rapid diagnosis of PTB and speed up initiation of TB treatment in settings equipped with real-time PCR platform.

Graphene oxide and self-avoiding molecular recognition systems-assisted recombinase polymerase amplification coupled with lateral flow bioassay for nucleic acid detection.

A new nucleic acid detection technique, termed Nano-SAMRS-RPA, is reported which employed carbon nanomaterial (graphene oxide, GO) and self-avoiding molecular recognition systems (SAMRS) to improve the specificity of recombinase polymerase amplification (RPA). In the presence of GO and SAMRS primers, the assay artifacts, including primer-dimers, nonspecific products, off-target hybrids, and non-canonical folds, are completely suppressed and eliminated, which makes the creation of RPA-based methods faster by simplifying the primer design and eliminating the need for primer optimization and complex probe. Moreover, a lateral flow bioassay (LFB) was also devised for simply and rapidly indicating the Nano-SAMRS-RPA results. Particularly, the new detection system only requires a single-labeled primer, eliminating the false-positive result from hybridization (the labeled probe and reverse primer) and the use of real-time instrument, more complex enzymatic solutions, and probes. As a result, GO, SAMRS primers, and LFB convert RPA from a technique suited only for the research laboratory into one that has a practical value in clinical settings, field environments, and at points-of-care testing. Human papillomaviruses (HPV) genotypes 16 and 18 were applied as model analytes to test the assay's availability. The initial data indicated that Nano-SAMRS-RPA could detect down to 10 copies per reaction, and the sensitivity (14/14 samples collected from HPV16 and HPV 18 patients) and specificity (75/75 samples collected from non-HPV patients) for clinical sample detection were 100%. The proof-of-concept technique can be reconfigured to detect various nucleic acid sequences by redesigning the specific RPA primers.Graphical abstract.

Development and Clinical Validation of Multiple Cross Displacement Amplification Combined With Nanoparticles-Based Biosensor for Detection of Mycobacterium tuberculosis: Preliminary Results.

Tuberculosis is still a major threat to global public health. Here, a novel diagnosis assay, termed as multiple cross displacement amplification combined with nanoparticle-based lateral flow biosensor (MCDA-LFB), was developed to simultaneously detect IS6110 and IS1081 of Mycobacterium tuberculosis (MTB) in DNA extracted from reference strain H37Rv and clinical samples. The amplification can be finished within 30 min at a fixed temperature (67°C), thus the whole procedure, including rapid template preparation (15 min), isothermal reaction (30 min) and result reporting (2 min), can be completed within 50 min. The limit of detection of multiplex MCDA assay was 10 fg per reaction. By using the multiplex MCDA protocol, cross-reaction with non-mycobacteria and non-tuberculous mycobacteria (NTM) strains was not observed. Among clinically diagnosed TB patients, the sensitivity of liquid culture, Xpert MTB/RIF and multiplex MCDA assay was 42.0% (50/119), 49.6% (59/119), and 88.2% (105/119), respectively. Among culture positive samples, the sensitivity of Xpert MTB/RIF and multiplex MCDA assay was 86.0% (43/50) and 98.0% (49/50), respectively. Among culture negative samples, the sensitivity of Xpert MTB/RIF and multiplex MCDA assay was 23.2% (16/69) and 81.2% (56/69), respectively. The specificity was 100% (60/60) for Xpert MTB/RIF and 98.3% (59/60) for multiplex MCDA. Therefore, the multiplex MCDA assay for MTB detection is rapid, sensitive and easy to use and may be a promising test for early diagnosis of TB.

Label-Free Cross-Priming Amplification Coupled With Endonuclease Restriction and Nanoparticles-Based Biosensor for Simultaneous Detection of Nucleic Acids and Prevention of Carryover Contamination.

Here, we reported on a label-free cross-priming amplification (CPA) scheme that utilized endonuclease restriction for simultaneous detection of nucleic acids and elimination of carryover contamination. Reaction mixtures were detected in a nanoparticle-based lateral flow biosensor (LFB). The assay exhibited attractive traits in that it did not require the use of labeled primers or labeled probes, and thus, the technique could prevent undesired results arising from unwanted hybridization between labeled primers or between a probe and labeled primer. Isothermal amplification and endonuclease restriction digestion were conducted in a single pot, and the use of a closed-tube amplification removed false-positive results due to contaminants. To validate the assay's applicability, we employed the novel technique to detect the pathogen Staphylococcus aureus in pure cultures and artificial blood samples. The assay could detect target bacterium in pure culture with a 100 fg.µL-1 detection limit, and in spiked blood samples with a 700 cfu.mL-1 detection limit. The whole process, including sample procedure (20-min), isothermal amplification (60-min), endonuclease digestion (10-min) and result reporting (within 2-min), could be finished within 95-min. As a poof-of-concept assay, the technique devised in the current report could be employed for detecting various other sequences if the specific CPA primers were available.

Detection of Nucleic Acids and Prevention of Carryover Contamination Using Cross-Priming Amplification Combined with Nanoparticles-Based Biosensor and Antarctic Thermal Sensitive Uracil-DNA-Glycosylase.

The current study reports on a cross-priming amplification (CPA) scheme that utilizes antarctic thermal sensitive uracilDNA-glycosylase (AUDG) for simultaneous detection of nucleic acids and prevention of carryover contamination. Amplification products were applied in a nanoparticle-based lateral flow biosensor (LFB). The method shows attractive features in that it only requires the use of a labeled primer, eliminating the use of labeled probes. Thus, it is able to remove false-positive results yielded by undesired hybridization between two labeled primers or between a probe and labeled primer. CPA amplification and AUDG cleavage are carried out in a single pot, and the use of a closed-vessel reaction eliminates unwanted results due to carryover contamination. Then, the assay devised in this report was applied to the detection of the hospital-acquired pathogen Klebsiella pneumoniae in pure cultures and artificial sputum samples. This biosensor can detect K. pneumoniae in pure cultures with a 100 fg · µL-1 detection limit, and in artificial sputum samples with a 520 cfu · mL-1 detection limit. The whole procedure, including specimen processing (20-min), CPA amplification (60-min), AUDG digestion (5-min) and result indicating (within 2-min), can be completed within 1.5 h. As a proof-of-concept technique, this method can be used for detecting a wide variety of other targets if the specific CPA primer set is available.

Simultaneous Nucleic Acids Detection and Elimination of Carryover Contamination With Nanoparticles-Based Biosensor- and Antarctic Thermal Sensitive Uracil-DNA-Glycosylase-Supplemented Polymerase Spiral Reaction.

The current report devised a novel isothermal diagnostic assay, termed as nanoparticle-based biosensor (NB)- and antarctic thermal sensitive uracil-DNA-glycosylase (ATSU)-supplemented polymerase spiral reaction (PSR; NB-ATSU-PSR). The technique merges enzymatic digestion of carryover contaminants and isothermal nucleic acid amplification technique (PSR) for simultaneous detection of nucleic acid sequences and elimination of carryover contamination. In particular, nucleic acid amplification and elimination of carryover contamination are conducted in a single pot and, thus, the use of a closed-tube reaction can remove undesired results due to carryover contamination. For demonstration purpose, Klebsiella pneumoniae is employed as the model to demonstrate the usability of NB-ATSU-PSR assay. The assay's sensitivity, specificity, and practical feasibility were successfully evaluated using the pure cultures and sputum samples. The amplification products were detectable from as little as 100 fg of genomic DNAs and from ~550 colony-forming unit (CFU) in 1 ml of spiked sputum samples. All K. pneumoniae strains examined were positive for NB-ATSU-PSR detection, and all non-K. pneumoniae strains tested were negative for the NB-ATSU-PSR technique. The whole process, including rapid template preparation (20 min), PSR amplification (60 min), ATSU treatment (5 min), and result reporting (within 2 min), can be finished within 90 min. As a proof-of-concept methodology, NB-ATSU-PSR technique can be reconfigured to detect various target nucleic acid sequences by redesigning the PSR primer set.

Clinical and Drug Resistance Characteristics of New Pediatric Tuberculosis Cases in Northern China.

AIM: The aim of this study was to evaluate the clinical features and characteristics of drug resistance in newly diagnosed pediatric tuberculosis (TB) patients in northern China. METHODS: Mycobacterium tuberculosis isolates were collected from September 2010 to October 2016 at the Beijing Children's Hospital. Patients were divided into two groups (resistant to at least one drug and pan-susceptible) according to drug susceptibility testing (DST) results. RESULTS: A total of 132 new cases, mainly from northern China (87.9%), were included in the study. The median age was 1.9 years (1 month-15 years). Resistance to at least one drug was detected in Mycobacterium tuberculosis isolates from 33 (25%) cases. Eight cases of multidrug-resistant TB (MDR-TB) (6.1%) were detected. The two groups did not differ in clinical presentations (disease site, fever >2 weeks, and cough >2 weeks) or in chest imaging (lesion location, lymphadenitis [mediastinal], and pleural effusion). CONCLUSIONS: The rate of Mycobacterium tuberculosis drug resistance in new pediatric TB cases was as high as in the new adult patients surveyed in the national drug resistance survey conducted in 2007. No significant difference was observed in clinical features between patients infected with drug-resistant and drug-susceptible strains. Routine DST is important for prescribing effective antituberculosis treatment regimens.

Discovery of susceptibility loci associated with tuberculosis in Han Chinese.

Genome-wide association studies (GWASs) have revealed the worldwide heterogeneity of genetic factors in tuberculosis (TB) susceptibility. Despite having the third highest global TB burden, no TB-related GWAS has been performed in China. Here, we performed the first three-stage GWAS on TB in the Han Chinese population. In the stage 1 (discovery stage), after quality control, 691 388 SNPs present in 972 TB patients and 1537 controls were retained. After replication on an additional 3460 TB patients and 4862 controls (stages 2 and 3), we identified three significant loci associated with TB, the most significant of which was rs4240897 (logistic regression P = 1.41 × 10-11, odds ratio = 0.79). The aforementioned three SNPs were harbored by MFN2, RGS12 and human leukocyte antigen class II beta chain paralogue encoding genes, all of which are candidate immune genes associated with TB. Our findings provide new insight into the genetic background of TB in the Han Chinese population.

Positive epistasis of major low-cost drug resistance mutations rpoB531-TTG and katG315-ACC depends on the phylogenetic background of Mycobacterium tuberculosis strains.

Mycobacterium tuberculosis Beijing genotype strains increasingly circulate in different world regions, either as historical endemic, e.g. in East Asia, or recently imported, e.g. in South America, and this family is regarded as the most successful lineage of the global tuberculosis (TB) epidemic. Here we analysed the transmission capacity of these strains in the context of their phylogenetic background and drug resistance mutations. The study collection included all multidrug resistant (MDR) strains of Beijing genotype isolated in Beijing Chest Hospital, the largest tertiary TB facility in North China, in 2011-2013 (n = 278). Strains were subjected to NTF/IS6110 and 24-loci MIRU-VNTR analysis. Drug resistance mutations were detected in rpoB, katG, inhA and oxyR-ahpC. A total of 58 and 220 strains were assigned to the ancient and modern Beijing sublineages, respectively. 24-MIRU-VNTR clustering was higher in modern versus ancient Beijing strains (35.9% vs. 12.1%; P <0.001). After taking into consideration the presence of rpoB and katG mutations, clustering decreased to 15.9% in modern and 0% in ancient strains. The most frequent combination of mutations (rpoB531-TTG and katG315-ACC) was more prevalent in clustered versus non-clustered isolates in the modern sublineage (23/35 vs. 47/185; P <0.0001). To conclude, a combination of the known low-fitness-cost rpoB531-TTG and katG315-ACC mutations likely facilitates the increased transmission ability of MDR strains of the modern but not ancient Beijing sublineage. Accordingly, positive epistasis of major low-cost drug resistance-conferring mutations is influenced by the phylogenetic background of M. tuberculosis strains.

Progress on mechanism of ethambutol resistance in Mycobacterium Tuberculosis.

The occurance and prevalence of multidrug-resistant tuberculosis poses a serious threat to the global tuberculosis control. Ethambutol (EMB) is one of the first-line anti-tuberculosis drugs, which is usually used in combination with isoniazid and rifampicin for treating pan-sensitive tuberculosis, and it can also be used in drug-resistant tuberculosis. However, the situation of EMB resistance is alarmingly high, especially in multi-drug resistant tuberculosis. In China, EMB resistance rate in the previously treated cases was up to 17.2% and showed an increased tendency. What was worse, 51.3%-66.7% of multidrug-resistant tuberculosis cases were resistant to EMB. Thus, it is important to understand the drug resistance mechanism of EMB, which will help to slow down the drug resistance rate of EMB. In this review, we focus on the current status of EMB resistance, the effects of EMB and the mechanisms of EMB resistance in Mycobacterium tuberculosis.

Identification of differentially expressed transcripts targeted by the knockdown of endogenous IFITM3.

Interferon inducible transmembrane protein 3 (IFITM3) is a double transmembrane protein. As a member of the IFITM family, IFITM3 can be upregulated by interferon (IFN) to be involved in various biological processes. In order to determine whether gene expression profiles can be altered by a lack of IFITM3, the present study used shRNAs lentivirus for knocking down the endogenous expression of IFITM3 in human HeLa cells and human whole genome microarrays to obtain gene expression profiles. A total of 1,011 downregulated transcripts and 615 upregulated transcripts were identified using the Agilent expression platform. The identified transcripts were involved in multiple pathways, including the complement pathways, and the antigen processing and presentation pathway. The present study identified the transcripts, which were affected by the downregulation of endogenous IFITM3 and the pathways they were involved in. These findings may lead to an improved understanding of the biological functions of IFITM3.