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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.

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., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Jiang, Sun, Wang, Qi, Tang, Wang, Han, Shi, Bi, Jiao and Shen.)

Objective: To evaluate the feasibility and tolerability of metoprolol standard dosing pathway (MSDP) in Chinese patients with acute coronary syndrome (ACS)., Methods: In this multicenter, prospective, open label, single-arm and interventional study that was conducted from February 2018 to April 2019 in fifteen Chinese hospitals. A total of 998 hospitalized patients aged ≥ 18 years and diagnosed with ACS were included. The MSDP was applied to all eligible ACS patients based on the standard treatment recommended by international guidelines. The primary endpoint was the percentage of patients achieving the target dose at discharge (V2). The secondary endpoints included the heart rate and blood pressure at V2 and four weeks after discharge (V4), and percentage of patients experiencing bradycardia (heart rate < 50 beats/min), hypotension (blood pressure < 90/60 mmHg) and transient cardiac dysfunction at V2 and V4., Results: Of the 998 patients, 29.46% of patients achieved the target dose (≥ 95 mg/d) at V2. The total population was divided into two groups: target group (patients achieving the target dose at V2) and non-target group (patients not achieving the target dose at V2). There was significant difference in the reduction of heart rate from baseline to discharge in the two groups (-4.97 ± 11.90 beats/min vs. -2.70 ± 9.47 beats/min, P = 0.034). There was no significant difference in the proportion of bradycardia that occurred in the two groups at V2 (0 vs. 0, P = 1.000) and V4 (0.81% vs. 0.33%, P = 0.715). There was no significant difference in the proportion of hypotension between the two groups at V2 (0.004% vs. 0.004%, P = 1.000) and V4 (0 vs. 0.005%, P = 0.560). No transient cardiac dysfunction occurred in two groups during the study. A total of five adverse events (1.70%) and one serious adverse event (0.34%) were related to the pathway in target group., Conclusions: In Chinese ACS patients, the feasibility and tolerability of the MSDP have been proved to be acceptable., (© 2023 JGC All rights reserved; www.jgc301.com.)

Monkeypox is a zoonotic disease. Since the first human monkeypox case was detected in 1970, it has been prevalent in some countries in central and western Africa. Since May 2022, monkeypox cases have been reported in more than 96 non-endemic countries and regions worldwide. As of September 14, 2022, there have been more than 58,200 human monkeypox cases, and there is community transmission. The cessation of smallpox vaccination in 1980, which had some cross-protection with monkeypox, resulted in a general lack of immunity to monkeypox, which caused global concern and vigilance. As of September 14, 2022, there are four monkeypox cases in China, including three in Taiwan province and one in Hong Kong city. Previous foreign studies have shown that children are vulnerable to monkeypox and are also at high risk for severe disease or complications. In order to improve pediatricians' understanding of monkeypox and achieve early detection, early diagnosis, early treatment,  and early disposal, we have organized national authoritative experts in pediatric infection, respiratory, dermatology, critical care medicine, infectious diseases, and public health and others to formulate this expert consensus, on the basis of the latest "Clinical management and infection prevention and control for monkeypox" released by The World Health Organization, the "guidelines for diagnosis and treatment of monkeypox (version 2022)" issued by National Health Commission of the People's Republic of China and other relevant documents. During the development of this consensus, multidisciplinary experts have repeatedly demonstrated the etiology, epidemiology, transmission, clinical manifestations, laboratory examinations, diagnosis, differential diagnosis, treatment, discharge criteria, prevention, disposal process, and key points of prevention and control of suspected and confirmed cases., (© 2022. Children's Hospital, Zhejiang University School of Medicine.)

The pharmacokinetic (PK) studies of meropenem in Chinese newborns with late-onset sepsis (LOS) are still lacking. Causative pathogens of LOS and their susceptibility patterns in China differ from the data abroad. We, therefore, conducted a developmental population pharmacokinetic−pharmacodynamic analysis in Chinese newborns with the goal to optimize meropenem dosing regimens for LOS therapy. An opportunistic sampling strategy was used to collect meropenem samples, followed by model building and validation. A Monte Carlo simulation was performed to show the probability of target attainment (PTA) for various dosages. The information from 78 newborns (postmenstrual age: 27.4−46.1 weeks) was compiled and had a good fit to a 1-compartment model that had first order elimination. The median (range) values of estimated weight−normalized volume of distribution (V)and clearance (CL) were 0.60 (0.51−0.69) L/kg and 0.16 (0.04−0.51) L/h/kg, respectively. Covariate analysis revealed that postnatal age (PNA), gestational age (GA) and current weight (CW) were the most important factors in describing meropenem PK. Simulation results showed for LOS with a minimal inhibitory concentration (MIC) of 8 mg/L, the doses of 30 mg/kg 3 times daily (TID) as a 1-h infusion for newborns with GA ≤ 37 weeks and 40 mg/kg TID as a 3-h infusion for those with GA > 37 weeks were optimal, with PTA of 71.71% and 75.08%, respectively. In conclusion, we proposed an evidence-based dosing regimen of meropenem for LOS in Chinese newborns by using the population pharmacokinetic−pharmacodynamic analysis, based on domestic common pathogens and their susceptibility patterns.

BACKGROUND: The quality of available clinical practice guidelines (CPGs) for childhood wheezing disorders have not been systematically evaluated. METHODS: CPGs were systematically evaluated by four independent reviewers using Appraisal of Guidelines Research and Evaluation (AGREE) II instrument and the Reporting Items for Practice Guidelines in HealTHcare (RIGHT) checklist. We calculated the overall agreement among reviewers with the intraclass correlation coefficient (ICC). RESULTS: A total of 35 CPGs published between January 2000 and December 2020 were evaluated. The overall agreement among reviewers was good (ICC 0.85, 95% CI 0.83-0.87). The average CPGs score was 42% (range: 25-79). The mean scores of four domains were low: 37% for Stakeholder Involvement (range: 10-85), 28% for Rigour of Development (range: 42-81), 35% for Applicability (range: 11-73) and 24% for Editorial Independence (range: 0-83). The mean reporting rate of the RIGHT checklist was 31%. The Basic Information domain had the highest reporting rate (65%); the Review and Quality Assurance domain had the lowest rate (3%). CONCLUSIONS: The quality of the CPGs was poor. Greater efforts are needed to improve quality in domains to provide high-quality guidelines that can be used as reliable tools for clinical decision-making.

Objective: The decision of vancomycin dosage for central nervous system (CNS) infections is still a challenge because its bactericidal nature in cerebrospinal fluid (CSF) has not been confirmed by human studies. This study systematically reviewed the literatures on vancomycin in patients with meningitis, ventriculitis, and CNS device-associated infections, to assess efficacy, safety, and pharmacokinetics to better serve as a practical reference. Methods: Medline, Embase, and Cochrane Library were searched using terms vancomycin, Glycopeptides, meningitis, and central nervous system infections. Data were extracted including characteristics of participants, causative organism(s), administration, dosage, etc., The clinical response, microbiological response, adverse events and pharmacokinetic parameters were analyzed. Results: Nineteen articles were included. Indications for vancomycin included meningitis, ventriculitis, and intracranial device infections. No serious adverse effects of intravenous (IV) and intraventricular (IVT) vancomycin have been reported. Dosages of IV and IVT vancomycin ranged from 1000-3000 mg/day and 2-20 mg/day. Duration of IV and IVT vancomycin therapy most commonly ranged from 3-27 days and 2-21 days. Therapeutic drug monitoring was conducted in 14 studies. Vancomycin levels in CSF in patients using IV and IVT vancomycin were varied widely from 0.06 to 22.3 mg/L and 2.5-292.9 mg/L. No clear relationships were found between vancomycin CSF levels and efficacy or toxicity. Conclusion: Using vancomycin to treat CNS infections appears effective and safe based on current evidence. However, the optimal regimens are still unclear. Higher quality clinical trials are required to explore the vancomycin disposition within CNS., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Liu, Xiao, Liu, Wu, Qi, Wang, Shen, Liu and Zhao.)

Background: Pneumonia, caused by infection or other factors, seriously endangers the health of children. Meropenem is an effective broad-spectrum antibiotic using in the treatment of infectious diseases. In the therapy of pneumonia, meropenem is mostly employed for the treatment of moderate to severe pneumonia. Previously, we established a population pharmacokinetics (PPK) model for meropenem in pediatric severe infection and simulated the control rate of the time during which the free plasma concentration of meropenem exceeds the minimum inhibitory concentration (MIC) is 70% of the dosing interval (70% fT > MIC). Therefore, we plan to conduct a multicenter randomized controlled trial (RCT) to compare the efficacy and safety between conventional regimen and model regimen for meropenem in pediatric severe pneumonia. Methods: One hundred patients (aged 3 months to 15 years) will be recruited in this RCT. They will be assigned randomly (at a 1:1 ratio) to a conventional treatment group (20 mg/kg, q8h, with 0.5-1 h infusion) and a model treatment group (20 mg/kg, q8 h, with 4 h infusion). The primary outcome will be 70% fT > MIC. Secondary outcomes will be the prevalence of meropenem therapy failure, duration of antibiotic therapy, changes in levels of inflammatory indicators, changes in imaging examination results, and prevalence of adverse events. Ethical approval of our clinical trial has been granted by the ethics committee of Beijing Children's Hospital ([2022]-E-133-Y). This trial has been registered in the Chinese Clinical Trial Registry (ChiCTR2200061207). Discussion: Based on our previous PPK data, we have designed this RCT. It is hoped that it will promote rational use of antibacterial drugs in children suffering from severe pneumonia. Clinical Trial Registration : http://www.chictr.org.cn identifier, ChiCTR2200061207., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Tian, Dong, Jiang, Tang, Wang, Wu, You, Bi, Qian, Qi and Shen.)

Objective: To provide theoretical basis for early diagnosis and accurate bronchoscopic classification of tracheobronchial tuberculosis (TBTB) in children through analyzing the clinical characteristics, bronchoscopic classifications and treatment effect in children with TBTB. Methods: In this respective study, we collected clinical data of patients with TBTB who accepted bronchoscopies in Interventional Pulmonology Department of Beijing Children's Hospital Affiliated to Capital Medical University between January, 2006 and December, 2019. The basic data, including clinical manifestations, imaging features, bronchoscopic characteristics and effects of interventional therapy were analyzed. The results of the study were statistically described and analyzed using SPSS 22.0 statistical software for relevant data. Results: Total 252 children with TBTB were included in this study. The median age was 1.7 years (quartile: 0.8 years, 5.2 years). Analysis of the classification of TBTB showed that the percent of lymph node fistula type was 96.4% (243/252), ulcerative necrosis type 1.2%(3/252), granulation proliferation type 0.4% (1/252), and cicatricial stricture type 0.8% (2/252). In addition, 1.2% (3/252) of the cases showed the same bronchoscopic manifestations as lymph node fistula type, but it was not clear on imaging whether the caseous material in the lumen was caused by lymph node or lung erosion. Therefore, the "bronchial fistula type" was proposed. Conclusions: Lymph node fistula type of TBTB was the common in children. The classification of lymph node fistula mostly depended on imaging evidence, and this may lead to some uncertainty in classifying TBTB in cases with no imaging evidence of enlarged lymph nodes.

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., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Jiao, Wang, Sun, Xiao, Li, Wang, Quan, Huang and Shen.)

Background: Population pharmacokinetic evaluations have been widely used in neonatal pharmacokinetic studies, while machine learning has become a popular approach to solving complex problems in the current era of big data., Objective: The aim of this proof-of-concept study was to evaluate whether combining population pharmacokinetic and machine learning approaches could provide a more accurate prediction of the clearance of renally eliminated drugs in individual neonates., Methods: Six drugs that are primarily eliminated by the kidneys were selected (vancomycin, latamoxef, cefepime, azlocillin, ceftazidime, and amoxicillin) as 'proof of concept' compounds. Individual estimates of clearance obtained from population pharmacokinetic models were used as reference clearances, and diverse machine learning methods and nested cross-validation were adopted and evaluated against these reference clearances. The predictive performance of these combined methods was compared with the performance of two other predictive methods: a covariate-based maturation model and a postmenstrual age and body weight scaling model. Relative error was used to evaluate the different methods., Results: The extra tree regressor was selected as the best-fit machine learning method. Using the combined method, more than 95% of predictions for all six drugs had a relative error of < 50% and the mean relative error was reduced by an average of 44.3% and 71.3% compared with the other two predictive methods., Conclusion: A combined population pharmacokinetic and machine learning approach provided improved predictions of individual clearances of renally cleared drugs in neonates. For a new patient treated in clinical practice, individual clearance can be predicted a priori using our model code combined with demographic data., (© 2021. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

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., (Copyright © 2021. Published by Elsevier B.V.)

Early-onset neonatal sepsis (EONS), a bacterial infection that occurs within 72 h after birth, is associated with high likelihood of neonatal mortality. Latamoxef, a semi-synthetic oxacephem antibiotic developed in 1980s, has been brought back into empirical EONS treatment in recent years. In the preliminary work, we established a population pharmacokinetics (PPK) model for latamoxef in Chinese neonates. Moreover, in order to better guide clinical treatment, we conducted dose simulation and found that ascending administration frequency could improve the target rate of 70% of patients having a free antimicrobial drug concentration exceeding the MIC during 70% of the dosing interval (70% fT > MIC). Accordingly, this study is aimed to compare the 70% fT > MIC, efficacy and safety between conventional regimen and PPK model regimen for rational use of latamoxef in EONS treatment. A single-blind, multicenter randomized controlled trial (RCT) for latamoxef will be conducted in Chinese EONS patients. Neonates (≤3 days of age, expected number = 114) admitted to the hospital with the diagnosis of EONS and fulfilling inclusion and exclusion criteria will be randomized (ratio of 1:1) to either a conventional regimen (30 mg/kg q12h) or model regimen (20 mg/kg q8h) latamoxef treatment group for at least 3 days. Primary outcome measure will be 70% fT > MIC and secondary outcome indicators will be the latamoxef treatment failure, duration of antibiotic therapy, changes of white blood cell count (WBC), C-reactive protein (CRP) and procalcitonin (PCT), blood culture results during administration and incidence of adverse event (AE)s. Assessments will be made at baseline, initial stage of latamoxef treatment (18-72 h) and before the end of latamoxef treatment. Ethical approval of our clinical trial has been granted by the ethics committee of the Beijing Children's Hospital (ID: 2020-13-1). Written informed consent will be obtained from the parents of the participants. This trial is registered in the Chinese Clinical Trial Registry (ChiCTR 2000040064).It is hoped that our study will provide a clinical basis for the rational clinical use of latamoxef in EONS treatment., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Qi, Wu, Liu, Kou, Wang, Peng, Chen, Cui, Wang, Li, Zhao and Shen.)

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.

Purpose: To assess ceftriaxone population pharmacokinetics in a large pediatric population and describe the proper dose for establishing an optimized antibiotic regimen., Methods: From pediatric patients using ceftriaxone, blood samples were obtained and the concentration was measured using high-performance liquid chromatography ultraviolet detection. The NONMEM software program was used for population pharmacokinetic analysis, for which data from 99 pediatric patients (2 to 12 years old) was collected and 175 blood concentrations were obtained., Results: The best fit with the data was shown by the one-compartment model with first-order elimination. According to covariate analysis, weight had a significant impact on the clearance of ceftriaxone. Using Monte Carlo simulation, in a pediatric population with community-acquired pneumonia, a dose regimen of 100 mg/kg every 24 h produced satisfactory target attainment rates while remaining within the required minimum inhibitory concentration (2 mg/L)., Conclusion: Population pharmacokinetics of ceftriaxone was evaluated in children and an optimum dosing regimen was constructed on the basis of the pharmacokinetics-pharmacodynamics model-based approach.

Data of developmental pharmacokinetics (PK) of meropenem in critically ill infants and children with severe infections are limited. We assessed the population PK and defined the appropriate regimen to optimize treatment in this population based on developmental PK-pharmacodynamic (PD) analysis. Blood samples were collected from pediatric intensive care unit patients with severe infection treated with standard dosage regimens for meropenem. Population PK data were analyzed using NONMEM software. Fifty-seven patients (mean age, 2.96 years [range, 0.101 to 14.4]; mean body weight, 15.8 kg [range, 5.0 to 65.0]) were included. A total of 135 meropenem concentrations were obtainable for population PK modeling. The median number of samples per patients was 2 (range, 1 to 4). A two-compartment model with first-order elimination was optimal for PK modeling. Weight and creatinine clearance (estimated by the Schwartz formula) were significantly correlated with the PK parameters of meropenem. The probabilities of target attainment for pathogens with low MICs of 1 and 2 μg/ml were 87.5% and 68.6% following administration of 40 mg/kg/dose (every 8 h [q8h]) as a 4-h infusion and 98.0% and 73.3% with high MICs of 4 and 8 μg/ml following administration of 110 mg/kg/day as a continuous infusion in critically ill infants and children under 70% fT >MIC (the free time during which the plasma concentration of meropenem exceeds the MIC), respectively. The standard dosage regimens for meropenem did not meet an appropriate PD target, and an optimal dosing regimen was established in critically ill infants and children. (This study has been registered at ClinicalTrials.gov under identifier NCT03643497.)., (Copyright © 2020 American Society for Microbiology.)

Objectives: To evaluate the population pharmacokinetics of cefoperazone in children and establish an evidence-based dosing regimen using a developmental pharmacokinetic-pharmacodynamic approach in order to optimize cefoperazone treatment., Methods: A model-based, open-label, opportunistic-sampling pharmacokinetic study was conducted in China. Blood samples from 99 cefoperazone-treated children were collected and quantified by HPLC/MS. NONMEM software was used for population pharmacokinetic-pharmacodynamic analysis. This study was registered at ClinicalTrials.gov (NCT03113344)., Results: A two-compartment model with first-order elimination agreed well with the experimental data. Covariate analysis showed that current body weight had a significant effect on the pharmacokinetics of cefoperazone. Monte Carlo simulation showed that for bacteria for which cefoperazone has an MIC of 0.5 mg/L, 78.1% of hypothetical children treated with '40 mg/kg/day, q8h, IV drip 3 h' would reach the pharmacodynamic target. For bacteria for which cefoperazone has an MIC of 8 mg/L, 88.4% of hypothetical children treated with 80 mg/kg/day (continuous infusion) would reach the treatment goal. A 160 mg/kg/day (continuous infusion) regimen can cover bacteria for which cefoperazone has an MIC of 16 mg/L. Nevertheless, even if using the maximum reported dose of 160 mg/kg/day (continuous infusion), the ratio of hypothetical children reaching the treatment target was only 9.9% for bacteria for which cefoperazone has an MIC of 32 mg/L., Conclusions: For cefoperazone, population pharmacokinetics were evaluated in children and an appropriate dosing regimen was developed based on developmental pharmacokinetics-pharmacodynamics. The dose indicated in the instructions (20-160 mg/kg/day) can basically cover the clinically common bacteria for which cefoperazone has an MIC of ≤16 mg/L. However, for bacteria for which the MIC is >16 mg/L, cefoperazone is not a preferred choice., (© The Author(s) 2020. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

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., (Copyright © 2019 Wang, Jiao, Wang, Sun, Li, Wang, Xiao, Shen, Xu, Qi, Wang, Guo and Shen.)

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 IS 6110 and IS 1081 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., (Copyright © 2019 Jiao, Wang, Wang, Wang, Xiao, Sun, Li, Wen, Zhang, Ma, Huang and Shen.)

Mycoplasma pneumoniae (M. pneumoniae) is one of the most common causes of community-acquired respiratory tract infections (RTIs). We aimed to investigate the prevalence of M. pneumoniae infection, antibiotic resistance and genetic diversity of M. pneumoniae isolates across multiple centers in Beijing, China. P1 protein was detected by Nested PCR to analyze the occurrence of M. pneumoniae in pediatric patients with RTI. M. pneumoniae isolates were cultured and analyzed by Nested-PCR to determine their genotypes. Broth microdilution method was used to determine the minimum inhibitory concentration (MIC) of antibiotics. Out of 822 children with RTI admitted to 11 hospitals in Beijing, 341 (41.48%) were positive for M. pneumoniae by Nested PCR and 236 (69.21%) samples had mutations in 23S rRNA domain V. The highest proportion of M. pneumoniae positive samples was observed in school-age children (118/190; 62.11%) and in pediatric patients with pneumonia (220/389; 56.56%). Out of 341 M. pneumoniae positive samples, 99 (12.04%) isolates were successfully cultured and the MIC values were determined for 65 M. pneumoniae strains. Out of these, 57 (87.69%) strains were resistant to macrolides, and all 65 strains were sensitive to tetracyclines or quinolones. M. pneumoniae P1 type I and P1 type II strains were found in 57/65 (87.69%) and 8/65 (12.31%) of cultured isolates, respectively. Overall, we demonstrated a high prevalence of M. pneumoniae infection and high macrolide resistance of M. pneumoniae strains in Beijing. School-age children were more susceptible to M. pneumoniae, particularly the children with pneumonia. Thus, establishment of a systematic surveillance program to fully understand the epidemiology of M. pneumoniae is critical for the standardized use of antibiotics in China.

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.

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 · μ L -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.

Objectives: There has been recent renewed interest in historical antibiotics because of the increased antibiotic-resistant bacterial strains. Latamoxef, a semi-synthetic oxacephem antibiotic developed in 1980s, has recently been brought back into use for treatment of infections in newborns; however, it is still used off-label in neonatal clinical practice due to the lack of an evidence-based dosing regimen. This study was performed to evaluate the pharmacokinetics of latamoxef in neonates and young infants, and to provide an evidence-based dosing regimen for newborns based on developmental pharmacokinetics-pharmacodynamics (PK-PD)., Methods: Opportunistic blood samples from newborns treated with latamoxef were collected to determine the latamoxef concentration by high-performance liquid chromatography with UV detection. Population PK-PD analysis was conducted using NONMEM and R software. A total of 165 plasma samples from 128 newborns (postmenstrual age range 28.4-46.1 weeks) were available for analysis., Results: A two-compartment model with first-order elimination showed the best fit with the data. Current body weight, birth weight, and postnatal age were identified as significant covariates influencing latamoxef clearance. Simulation indicated that the current dosing regimen (30 mg/kg q12h) is adequate with an MIC of 1 mg/L. For an MIC of 4 mg/L, 30 mg/kg q8h was required to achieve a target rate of 70% of patients having a free antimicrobial drug concentration exceeding the MIC during 70% of the dosing interval., Conclusions: Based on the developmental PK-PD analysis of latamoxef, a rational dosing regimen of 30 mg/kg q12h or q8h was required in newborns, depending on the pathogen., (Copyright © 2019. Published by Elsevier B.V.)

Amoxicillin is widely used to treat bacterial infections in neonates. However, considerable intercenter variability in dosage regimens of antibiotics exists in clinical practice. The pharmacokinetics of amoxicillin has been described in only a few preterm neonates. Thus, we aimed to evaluate the population pharmacokinetics of amoxicillin through a large sample size covering the entire age range of neonates and young infants and to establish evidence-based dosage regimens based on developmental pharmacokinetics-pharmacodynamics. This is a prospective, multicenter, pharmacokinetic study using an opportunistic sampling design. Amoxicillin plasma concentrations were determined using high-performance liquid chromatography. Population pharmacokinetic analysis was performed using NONMEM. A total of 224 pharmacokinetic samples from 187 newborns (postmenstrual age range, 28.4 to 46.3 weeks) were available for analysis. A two-compartment model with first-order elimination was used to describe population pharmacokinetics. Covariate analysis showed that current weight, postnatal age, and gestational age were significant covariates. The final model was further validated for predictive performance in an independent cohort of patients. Monte Carlo simulation demonstrated that for early-onset sepsis, the currently used dosage regimen (25 mg/kg twice daily [BID]) resulted in 99.0% of premature neonates and 87.3% of term neonates achieving the pharmacodynamic target (percent time above MIC), using a MIC breakpoint of 1 mg/liter. For late-onset sepsis, 86.1% of premature neonates treated with 25 mg/kg three times a day (TID) and 79.0% of term neonates receiving 25 mg/kg four times a day (QID) reached the pharmacodynamic target, using a MIC breakpoint of 2 mg/liter. The population pharmacokinetics of amoxicillin was assessed in neonates and young infants. A dosage regimen was established based on developmental pharmacokinetics-pharmacodynamics., (Copyright © 2019 American Society for Microbiology.)

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.

Azithromycin is extensively used in children with community-acquired pneumonia (CAP). Currently, the intravenous azithromycin is used off-label in children partly due to lacking of pharmacokinetic data. Our objective was to evaluate the population pharmacokinetics (PPK) and optimize dose strategy in order to improve treatment in this distinctive population. This was a prospective, multicenter, open-labeled pharmacokinetic study. Blood samples were collected from hospitalized pediatric patients and concentrations were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS). PPK analysis was conducted using NONMEM software. The pharmacokinetic data from 95 pediatric patients (age range, 2.1 to 11.7 years) were available for analysis. The PPK was best fitted by a two-compartment model with linear elimination. Covariate analysis verified that body weight and alanine aminotransferase (ALT) had significant effects on azithromycin pharmacokinetics, yielding a 24% decrease of clearance in patients with ALT of >40. Monte Carlo simulation showed that for children with normal liver function, a loading-dose strategy (a loading dose of 15 mg/kg of body weight followed by maintenance doses of 10 mg/kg) would achieve the ratio of the area under free drug plasma concentration-time curve over 24 h ( f AUC) to MIC 90 ( f AUC/MIC) target of 3 h in 53.2% of hypothetical patients, using a normative MIC susceptibility breakpoint of 2 mg/liter. For children with ALT of >40, the proposed dose needed to decrease by 15% to achieve comparable exposure. The corresponding risk of overdose for the recommended dosing regimen was less than 5.8%. In conclusion, the PPK of azithromycin was evaluated in children with CAP and an optimal dosing regimen was constructed based on developmental pharmacokinetic-pharmacodynamic modeling and simulation., (Copyright © 2018 American Society for Microbiology.)

Latamoxef, a broad-spectrum anti-bacterial agent of the β-lactam antibiotics, is used off-label in treatment of neonatal sepsis. Large inter-individual variability and uncertainty of treatment make therapeutic drug monitoring (TDM) useful to optimize antimicrobial therapy. The objective of this study was to develop and validate a simple, selective and reliable HPLC method for the determination of latamoxef in small volumes of plasma, which could be used in neonatal TDM. After a simple protein precipitation, analytes were separated with liquid chromatography and quantified by UV detection, with tinidazole as the internal standard. The calibration range was linear from 3.0 to 60.0 μg/mL. Intra- and inter-day precisions were < 7.2%. The acceptance criteria of accuracy (between 85 and 115%, 120% for lower limit of quantification) were met in all cases. A plasma volume of 50 μL was required to achieve the limit of quantification of 3.0 μg/mL. The TDM results showed a large variability in trough concentrations. A large number of patients were underdosed, highlighting the unmet need for TDM to optimize latamoxef therapy in neonates., (Copyright © 2018 John Wiley & Sons, Ltd.)

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., (© The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Background: Endobronchial tuberculosis (EBTB) is the most frequent complication of primary pulmonary tuberculosis (PTB) in children. The aim of the study was to analyze characteristics and clinical role of bronchoscopy in diagnosis of childhood EBTB., Methods: A retrospective, descriptive study was undertaken in 157 children with EBTB undergone flexible bronchoscopy (FB) between January 2006 and June 2014., Results: The median age of the enrolled patients was 3.4 years, with 73.2% of patients under five years old. The most common subtype was tumorous type (145/157, 92.4%). If only involved bronchus were considered, the common affected sites were right middle lobe bronchus (49/228, 21.5%), left upper lobe bronchus (41/228, 18.0%), right upper lobe bronchus (41/228, 18.0%), right main bronchus (35/228, 15.4%), respectively. Children younger than five years old were at higher risk to have multiple endobronchial lesions (P=0.044), with an odds ratio of 2.313 (95% confidence interval: 1.009-5.299). Before the bronchoscopy, only 16 (10.2%) patients were highly suspected of EBTB, while the others were diagnosed as PTB without EBTB (69.4%), or misdiagnosed as pneumonia or foreign body aspiration (20.4%) on admission., Conclusions: The patients under five years old are at high risk to progress to EBTB and have multiple endobronchial lesions. The most frequent subtype of EBTB in children is tumorous type. The lesions are seen in the right bronchial system more frequently. FB should be performed to detect the endobronchial lesions in suspected patients as soon as possible.

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., (Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.)

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.

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.

Mycobacterium tuberculosis Beijing genotype originated in China and has undergone a dramatic population growth and global spread in the last century. Here, a collection of M. tuberculosis Beijing family isolates from different provinces across all China was genotyped by high-resolution (24-MIRU-VNTR) and low-resolution, high-rank (modern and ancient sublineages) markers. The molecular profiles and global and local phylogenies were compared to the strain phenotype and patient data. The phylogeographic patterns observed in the studied collection demonstrate that large-scale (but not middle/small-scale) distance remains one of the decisive factors of the genetic divergence of M. tuberculosis populations. Analysis of diversity and network topology of the local collections appears to corroborate a recent intriguing hypothesis about Beijing genotype originating in South China. Placing our results within the Eurasian context suggested that important Russian B0/W148 and Asian/Russian A0/94-32 epidemic clones of the Beijing genotype could trace their origins to the northeastern and northwestern regions of China, respectively. The higher clustering of the modern isolates in children and lack of increased MDR rate in any sublineage suggest that not association with drug resistance but other (e.g., speculatively, virulence-related) properties underlie an enhanced dissemination of the evolutionarily recent, modern sublineage of the Beijing genotype in China.

Myeloid differentiation protein 2 (MD2) regulates bacterial lipopolysaccharide (LPS) triggered anti-bacterial immune response as a broker between LPS and Toll-like receptor 4 (TLR4). In this study, we identified a novel naturally occurring spliceosome of human MD2, termed as MD2-T3. This transcript lacked two exons of MD2 gene. By protein structure analysis and literature review, we predicted that MD2-T3 isoform might execute regulatory biological effects such as limiting LPS-triggered TLR4 signaling., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Although tuberculosis (TB) has been the greatest killer due to a single infectious disease, pediatric TB is still hard to diagnose because of the lack of sensitive biomarkers. Metabolomics is increasingly being applied in infectious diseases. But little is known regarding metabolic biomarkers in children with TB. A combination of a NMR-based plasma metabolic method and classification and regression tree (CART) analysis was used to provide a broader range of applications in TB diagnosis in our study. Plasma samples obtained from 28 active TB children and 37 non-TB controls (including 21 RTIs and 16 healthy children) were analyzed by an orthogonal partial least-squares discriminant analysis (OPLS-DA) model, and 17 metabolites were identified that can separate children with TB from non-TB controls. CART analysis was then used to choose 3 of the markers, l-valine, pyruvic acid, and betaine, with the least error. The sensitivity, specificity, and area under the curve (AUC) of the 3 metabolites is 85.7% (24/28, 95% CI, 66.4%, 95.3%), 94.6% (35/37, 95% CI, 80.5%, 99.1%), and 0.984(95% CI, 0.917, 1.000), respectively. The 3 metabolites demonstrated sensitivity of 82.4% (14/17, 95% CI, 55.8%, 95.3%) and specificity of 83.9% (26/31, 95% CI, 65.5%, 93.9%), respectively, in 48 blinded subjects in an independent cohort. Taken together, the novel plasma metabolites are potentially useful for diagnosis of pediatric TB and would provide insights into the disease mechanism.

Background: As the epidemic of MDR-TB and XDR-TB becomes increasingly severe, it is important to determine the clinical characteristics and molecular epidemiology of MDR-TB and XDR-TB. Recently, many studies have shown that clinical features and molecular characteristics of drug-resistant strains vary in different geographical areas, however, further information is needed to assess the dynamic evolution of drug-resistant TB. Comparative studies between different time periods are necessary to elucidate the development of drug-resistant TB., Results: A total of 255 and 537 strains were collected from Beijing Chest Hospital in 2006 and in 2012, respectively. Drug-resistance rates and mutations associated with resistance to first-line anti-tuberculosis (TB) drugs were compared. The overall rate of drug resistance among strains of TB in 2012 was 54.4 %, significantly higher than that in 2006 (34.9 %, P < 0.001). Rates of resistance to each first-line drug (isoniazid, rifampicin, streptomycin and ethambutol) and to second-line drug ofloxacin increased significantly from 2006 to 2012. The overall MDR rate also increased significantly from 2006 (14.9 %) to 2012 (27.0 %). The rate of MDR increased significantly between these two time periods in previously treated cases (P = 0.023) but not in new cases (P = 0.073), and the rate of XDR was similar in new cases at the two time periods, but was marginally higher in 2012 in previously treated cases (P = 0.056). Previous treatment was found to be a risk factor for drug-resistant TB, especially for MDR-TB. In addition, the proportion of drug resistant isolates in which katG, the mabA-inhA promoter, oxyR-ahpC intergenic region, rpoB, rpsL, and embB were mutated was similar in 2006 and 2012, however patterns of mutation in these loci were more diverse in 2012 compared to 2006., Conclusions: Our data suggests that the prevalence of drug resistant TB remains high in Beijing, China, and that increasing rates of resistance in M. tuberculosis to all anti-TB drugs should be considered when choosing an optimal anti-TB regimen. Moreover, acquired multi-drug resistance may play a primary role in the MDR-TB epidemic in Beijing, China. Consequently, this highlights the importance of an earlier start to effective and supervised treatment in order to reduce the burden of retreatment.

Mycobacterium tuberculosis can acquire resistance to rifampin (RIF) through mutations in the rpoB gene. This is usually accompanied by a fitness cost, which, however, can be mitigated by secondary mutations in the rpoA or rpoC gene. This study aimed to identify rpoA and rpoC mutations in clinical M. tuberculosis isolates in northern China in order to clarify their role in the transmission of drug-resistant tuberculosis (TB). The study collection included 332 RIF-resistant and 178 RIF-susceptible isolates. The majority of isolates belonged to the Beijing genotype (95.3%, 486/510 isolates), and no mutation was found in rpoA or rpoC of the non-Beijing genotype strains. Among the Beijing genotype strains, 27.8% (89/320) of RIF-resistant isolates harbored nonsynonymous mutations in the rpoA (n = 6) or rpoC (n = 83) gene. The proportion of rpoC mutations was significantly higher in new cases (P = 0.023) and in strains with the rpoB S531L mutation (P < 0.001). In addition, multidrug-resistant (MDR) strains with rpoC mutations were significantly associated with 24-locus mycobacterial interspersed repetitive-unit-variable-number tandem-repeat clustering (P = 0.016). In summary, we believe that these findings indirectly suggest an epistatic interaction of particular mutations related to RIF resistance and strain fitness and, consequently, the role of such mutations in the spread of MDR M. tuberculosis strains., (Copyright © 2016, American Society for Microbiology. All Rights Reserved.)

Interferon Gamma Release Assays (IGRAs) were developed for the indirect or immunologic diagnosis of tuberculosis infection; however, they have also been used to assist in difficult to diagnose cases of tuberculosis disease in adults, and to a lesser extent, in children, especially in those under 5 years old. We evaluated the utility of using an IGRA in pediatric tuberculosis in younger children in a hospital setting. The diagnostic accuracy of T-SPOT.TB and TST was assessed in 117 children with active tuberculosis and 413 children with respiratory tract infection. Sensitivity and specificity were calculated for the tests used individually and together. Concordance was also calculated. Sensitivity of T-SPOT.TB (82.9%) was higher than TST (78.6% using a 5mm cut-off), especially in children confirmed to have TB. T-SPOT.TB was more specific than TST using a 5mm cut-off (96.1% vs. 70.9%). Combining T-SPOT.TB and TST results improved the sensitivity to 96.6%. In conclusion, the results of the current study indicate that T-SPOT.TB has good sensitivity and specificity, supporting its use among patients of this age. A combination of IGRA and TST would be useful additions to assist in the diagnosis of childhood TB.

The available data on the epidemic of drug resistant tuberculosis (TB) among children in China is limited. This study attempted to clarify the drug resistance profiles of clinical strains isolated from children and estimate risk factors related to acquisition of drug resistance. All Mycobacterium tuberculosis strains from children (age <15 years) and adolescent (age 15-18 years) TB patients received in the strain library of Chinese Center for Disease Control and Prevention between January 2005 and December 2012 were included in the study. A study collection included 450 clinical isolates (100 from children, 159 from adolescents, and 191 from adults) from all over China. Drug susceptibility testing was performed by a proportion method. As a result, the drug resistance and multi-drug resistance (MDR) rates in children were 55% (55/100) and 22% (22/100), respectively. In children with MDR-TB, new cases accounted for 40.9% (9/22). Compared with adults, the drug resistance rates were similar in all subgroups (new cases, previously treated cases and all cases) of children (P > 0.05), except for the lower resistance rate to isoniazid in total cases of children (P = 0.011). Patient related information was included in the MDR-TB association analysis. The treatment history was found to be strongly associated with MDR-TB in all three age groups (P < 0.05). Our results demonstrate that the prevalence of drug resistant TB in children in China is alarmingly high and similar to that seen in adults. In contrast, in adolescents, the drug resistance rate to most tested drugs was lower than in adults. Primary transmission and inadequate treatment are two equally important factors for the high MDR-TB rate in children. Thus, major efforts in the TB control in children should focus on decreasing the transmission of drug resistant TB and early testing of drug resistance., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Background: Anti-tuberculosis drug induced hepatotoxicity (ATDH) is a major adverse drug reaction associated for anti-tuberculosis therapy. The glutathione S-transferases (GST) plays a crucial role in the detoxification of hepatotoxic metabolites of anti-tuberculosis drugs.An association between GSTM1/GSTT1 null mutations and increased risk of ATDH has been demonstrated in adults. Given the ethnic differences and developmental changes, our study aims to investigate the potential impacts of GSTM1/GSTT1 genotypes on the development of ATDH in Han Chinese children treated with anti-tuberculosis therapy., Methods: Children receiving anti-tuberculosis therapy with or without evidence of ATDH were considered as the cases or controls, respectively. The GSTM1 and GSTT1 genotyping were performed using the polymerase chain reaction., Results: One hundred sixty-three children (20 cases and 143 controls) with a mean age of 4.7 years (range: 2 months-14.1 years) were included. For the GSTM1, 14 (70.0%) cases and 96 (67.1%) controls had homozygous null mutations. For the GSTT1, 13 (65.0%) cases and 97 (67.8%) controls had homozygous null mutations. Neither the GSTM1, nor the GSTT1 polymorphism was significantly correlated with the occurrence of ATHD., Conclusion: Our results did not support the GSTM1 and GSTT1 polymorphisms as the predictors of ADTH in Chinese Han children treated with anti-tuberculosis drugs. An age-related association between pharmacogenetics and ATHD need to be confirmed in the further study.

Objective: To investigate nasopharyngeal carriage rate, antimicrobial resistance and serotype distribution of Streptococcus pneumoniae among children with upper respiratory infection., Methods: Nasopharygeal swabs were collected from children with upper respiratory infection visiting the outpatient department of Beijing Children′s Hospital between March 2013 and February 2014. The antibiotic susceptibility was tested by Etest method, and the serotype was determined by Quellung reaction., Results: The nasopharyngeal carriage rate for Streptococcus pneumoniae was 23.8% (699/2 941). One hundred isolates were randomly chosen for antimicrobial susceptiblity test and serotyping. Up to 98.0% isolates were susceptible to parenteral penicillin. The susceptible rate against oral penicillin, however, was 33.0%. The non-susceptible rate to erythromycin and azithromycin was 97.0%. The multi-drug resistance rate was up to 86.0%. The common serotypes were 6A(12.0%), 19F(12.0%), 6B(10.0%), 23F(9.0%) and 14(8.0%). The coverage rates of 7-, 10- and 13-valent pneumococcal conjugate vaccine were 41.0%, 42.0% and 59.0% respectively., Conclusions: About 25% of children with upper respiratory infection are nasopharyngeal colonized by Streptococcus pneumoniae. The isolates show a high antimicrobial resistance. The 13-valent pneumococcal conjugate vaccine covers about 60.0% of the isolates.

Nowadays, enzyme-linked immunosorbent assay (ELISA) based detection of Mycobacterium tuberculosis (M. tuberculosis) antigen triggered interferon-gamma (IFN-g) secretion by blood T cells displays an improved diagnostic value for M. tuberculosis infection. Applications of fluorescence correlation spectroscopy (FCS) have been explored in various subfields of medicine and molecular biology, including detection of a certain biomarker in liquid instead of ELISA. Here, we present a preliminary study of detecting IFN-g using FCS-based technique., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Mycobacterium tuberculosis Beijing genotype strains are rapidly disseminating, frequently hypervirulent, and multidrug resistant. Here, we describe a method for their rapid detection by real-time PCR that targets the specific IS6110 insertion in the dnaA-dnaN genome region. The method was evaluated with a geographically and genetically diverse collection representing areas in East Asia and the former Soviet Union in which the Beijing genotype is endemic and epidemic (i.e., major foci of its global propagation) and with clinical specimens.

Interleukin-4 (IL-4) and IL-10, which are produced by Th2 cells, serve as anti-inflammatory cytokines in the immune responses to tuberculosis (TB). In order to investigate the association between susceptibility to TB and single-nucleotide polymorphisms (SNPs) of the IL-4 and IL-10 genes, a case-control study including 346 TB patients and 374 healthy controls was performed in Chinese Han children in North China. Though no significant differences in the allelic and genotypic distributions of SNPs of these two genes were observed between control group and TB group, rs2243268-A and rs2243274-G of the IL-4 gene were associated with reduced risk of developing extrapulmonary tuberculosis (EPTB) (Prs2243268=0.005 and Prs2243274=0.004) and severe TB (Prs2243268=0.003 and Prs2243274=0.003). The haplotype comprising rs2243268-A and rs2243274-G was found to be a resistance factor against EPTB and severe TB. In addition, after stimulation with inactivated H37Rv, blood samples of the rs2243268 AA+AC carriers showed significantly reduced IL-10 production (P=0.045) compared to the CC carriers. In conclusion, rs2243268-A and rs2243274-G of the IL-4 gene were found to confer resistance to EPTB and severe TB in Chinese Han children., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Tuberculosis (TB) is the leading cause of death due to an infectious disease worldwide, particularly in developing countries. A series of candidate genes have been suggested to be associated with development of TB disease. Among them, the human Cytokine-inducible Src homology 2(SH2) domain protein (CISH) gene has been very recently reported to be involved in T cell activation and differentiation in response to Mycobacterium tuberculosis infection. Here, we studied the association between CISH promoter polymorphisms and pediatric TB. A case-control study enrolled 352 TB patients and 527 healthy controls, who were of Han Chinese ethnicity and aged from 0.2 to 18 years. CISH gene promoter SNPs rs414171, rs622502 and rs809451 were genotyped in all subjects and transcriptional activity, mRNA level, and plasma cytokine level of subjects with different genotypes were further examined. Carriers with rs414171TT homozygotes and rs809451GC heterozygotes had a 1.78-fold (95% CI,1.16-2.74) and 1.86-fold (95% CI, 1.26-2.74) excess risk of developing TB compared to those with wild-type genotypes. A greater risk of TB disease was observed in population carrying C(-809451)-T(-414171)-C(-622502) haplotype (OR 3.66, 95% CI:2.12-6.32). The G(-809451)-A(-414171)-C(-622502)-containing CISH promoter drove a 5.43-fold increased reporter expression compared to the C(-809451)-T(-414171)-C(-622502)-containing counterpart in Hela cell lines (P = 0.0009). PBMCs carrying rs414171TT homozygotes and rs809451GC heterozygotes showed a reduced CISH mRNA level compared to cells carrying wild type genotypes. Individuals with the rs414171TT genotype had significantly increased IL-12p40 and IL-10 production. In conclusion, CISH promoter rs414171 and rs809451 polymorphisms may play a vital role in mediating individual susceptibility to tuberculosis.

Background: IL-6 is a proinflammatory cytokine that plays a critical role in host defense against tuberculosis (TB). Genetic polymorphisms of IL-6 and its receptor IL-6R had been discussed in adult TB recently. However, their role in pediatric TB is still unclear. Due to the obvious differences in TB pathophysiology in children, which may also reflect differences in genetic background, further association studies in pediatric populations are needed., Methods: A case-control study was carried out in a Chinese pediatric population including 353 TB patients and 400 healthy controls. Tag-SNPs of IL-6 and IL-6R genes were selected by Haploview software, genotyped using MassArray, and analyzed statistically., Results: One polymorphism, rs2229238, in the 3'UTR region of IL-6R was observed to be associated with increased resistance to TB (adjusted P = 0.03). The rs2229238 T allele contributed to a reduced risk to TB in recessive heritable model (OR, 0.53; 95% CI, 0.35-0.78)., Conclusions: By tag-SNP genotyping based case-control study, we identified a genetic polymorphism in the IL-6R 3'UTR that regulates host resistance to pediatric TB in a Chinese population.