PubMed | Peoples Hospital of Zhongjiang County, National Key Discipline of Pediatrics Capital Medical University, The First Affiliated Hospital of Chongqing Medical University and Chongqing Medical University
Type: Journal Article | Journal: Yi chuan = Hereditas | Year: 2016
There were some limitation in the current interpretation about the penicillin resistance mechanism of clinical Streptococcus pneumoniae isolates at the strain level. To explore the possibilities of studying the mechanism based on the sequence types (ST) of this bacteria, 488 isolates collected in Beijing from 1997-2014 and 88 isolates collected in Youyang County, Chongqing and Zhongjiang County, Sichuan in 2015 were analyzed by penicillin minimum inhibitory concentration (MIC) distribution and annual distribution. The results showed that the penicillin MICs of the all isolates covering by the given ST in Beijing have a defined range, either <0.25 mg/L or0.25 mg/L, except for the ST342. The isolates with penicillin MIC <0.25 mg/L were mainly collected before 2001, after which the isolates with MIC0.25 mg/L occurred and became the major population gradually. This law of year distribution, however, was not obvious for any specific ST. The isolates covering by any given ST could be determined with different penicillin MICs in the first few years after it was identified. The penicillin MIC of isolates identified as common STs and collected in Youyang County, Chongqing and Sichuan Zhongjiang County, including the ST271, ST320 and ST81, was around 0.25~2 mg/L (0.25 mg/L). Our study revealed the epidemiological distribution of penicillin MICs of the given STs determined in clinical S. pneumoniae isolates, suggesting that it is reasonable to research the penicillin resistance mechanism based on the STs of this bacteria.
Wang P.,National Key Discipline of Pediatrics Capital Medical University |
Wang P.,Capital Medical University |
Ma Z.,Shenzhen Childrens Hospital |
Tong J.,National Key Discipline of Pediatrics Capital Medical University |
And 6 more authors.
International Journal of Infectious Diseases | Year: 2015
Background: Group B Streptococcus (GBS) is an important neonatal pathogen associated with high morbidity and mortality in developed countries. However, data describing neonatal GBS disease in developing countries, particularly in Asia, are largely incomplete. The aim of this study was to determine the serotype distribution, antimicrobial resistance, and molecular characteristics of invasive GBS isolates recovered from Chinese neonates. Methods: From 2008 to 2013, 40 GBS isolates were recovered from infected neonates less than 3 months of age. All isolates were identified with the CAMP test and commercially available techniques. Serotyping was performed by latex agglutination. Antibiotic susceptibility was tested with Etest strips and the disk diffusion method. Multilocus sequence typing and erythromycin resistance gene detection (ermB and mefA) were performed by PCR. Results: Four serotypes were identified. Serotype III (85%) was the most prevalent, followed by Ia (7.5%), Ib (5%), and V (2.5%). All isolates were sensitive to penicillin, ceftriaxone, and levofloxacin. However, resistance to erythromycin (92.5%), clindamycin (87.5%), and tetracycline (100%) was observed. Among erythromycin-resistant isolates, 73.0% carried the ermB gene alone, 5.4% carried the mefA gene alone, and 21.6% expressed both ermB and mefA genes. A total of seven sequence types (STs) were identified; the most prevalent was ST17, accounting for 80% of all isolates. Further, serotype III isolates contained ST17 (94.2%), ST19 (2.9%), and ST650 (2.9%). Conclusion: Serotype distribution, antimicrobial susceptibility, and sequence type characterization in Asia and in other global regions may contribute to improve the prevention and treatment of neonatal GBS infections. © 2015 The Authors.
Yin J.,National Key Discipline of Pediatrics Capital Medical University |
Yu S.,National Key Discipline of Pediatrics Capital Medical University |
Liu X.,National Key Discipline of Pediatrics Capital Medical University |
Li Y.,National Key Discipline of Pediatrics Capital Medical University |
And 5 more authors.
Diagnostic Microbiology and Infectious Disease | Year: 2012
Beta-Hemolytic group G streptococci cause a considerable invasive disease burden and sometimes disease outbreaks. Little is known about the critical epidemiologic parameter of genetic relatedness between isolates. We determined the emm types of 65 Streptococcus dysgalactiae subsp. equisimilis isolates. We formulated multilocus sequence typing (MLST) primers with 6 of the 7 loci corresponding to the Streptococcus pyogenes MLST scheme. We performed MLST with 69 S. dysgalactiae subsp. equisimilis isolates to represent each emm type identified. These strains were further analyzed by pulsed-field gel electrophoresis (PFGE) typing. Sixteen emm types were observed. Eighteen unique combinations of allelic profiles (sequence types [STs]) were obtained with 12 profiles each accounting for multiple isolates. Forty-one MLST STs were observed. Analysis of the PFGE patterns generated revealed 10 clones. Over 80% of the isolates were distributed in 3 large clones. Isolates within 16 redundantly represented S. dysgalactiae subsp. equisimilis emm types shared identical or nearly identical STs and subtypes of PFGE, demonstrating concordance between the emm type and genetic relatedness. It is conceivable that some particular characteristics in the genomes of these strains are responsible for their predominance in different regions. © 2012 Elsevier Inc.
Shen C.,National Key Discipline of Pediatrics Capital Medical University |
Shen A.-D.,National Key Discipline of Pediatrics Capital Medical University
Gene | Year: 2016
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. © 2016 Elsevier B.V.
Sun L.,National Key Discipline of Pediatrics Capital Medical University |
Li J.-Q.,National Key Discipline of Pediatrics Capital Medical University |
Ren N.,National Key Discipline of Pediatrics Capital Medical University |
Qi H.,National Key Discipline of Pediatrics Capital Medical University |
And 7 more authors.
Journal of Proteome Research | Year: 2016
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. © 2016 American Chemical Society.
Shi W.,National Key Discipline of Pediatrics Capital Medical University |
Yao K.,National Key Discipline of Pediatrics Capital Medical University |
He M.,National Key Discipline of Pediatrics Capital Medical University |
Yu S.,National Key Discipline of Pediatrics Capital Medical University |
Yang Y.,National Key Discipline of Pediatrics Capital Medical University
BMC Infectious Diseases | Year: 2014
Background: In this study, we defined the population biology of serogroup 6 Streptococcus pneumoniae collected in China and their antibiotic resistance profiles. Methods: The serotypes of 225 S. pneumoniae strains isolated between 1997 and 2011 were identified with the Quellung reaction and serotype-specific PCR. All isolated pneumococci were tested for their sensitivity to 11 kinds of antibiotics with the E-test method or disc diffusion. The sequence types (STs) were analyzed with multilocus sequence typing (MLST). Results: The frequencies of serotypes and subtypes 6A, 6B-I, 6B-II, 6C, and 6D among the 225 isolates were 46.7% (105/225), 19.6% (44/225), 25.8% (58/225), 6.2% (14/225), and 1.8% (4/225), respectively. Serotype 6E was not found in the serotype 6A isolates, and neither serotype 6F nor 6G was identified in any isolate. MLST analysis revealed 58 STs. The most common STs were ST982 (23.1%), ST90 (14.7%), ST4542 (7.6%), and ST2912 (4.9%). The rates of clonal complex 90 (CC90) and CC386 among the oral-penicillin-nonsusceptible isolates decreased over the years, whereas the rates of CC855 and CC3173 increased. The four CCs had similar penicillin MIC distributions, with a maximum MIC of 2 μg/ml. Conclusions: This study identified the serotypes/subtypes and CCs/STs of group 6 S. pneumoniae present in China. No salient antibiotic-resistant clones were isolated among the serogroup 6 S. pneumoniae. © 2014 Shi et al.; licensee BioMed Central Ltd.
PubMed | National Key Discipline of Pediatrics Capital Medical University
Type: Journal Article | Journal: Gene | Year: 2016
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.
PubMed | Capital Medical University and National Key Discipline of Pediatrics Capital Medical University
Type: | Journal: BMC microbiology | Year: 2016
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.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.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.
PubMed | National Key Discipline of Pediatrics Capital Medical University and Childrens Hospital of Hebei Province
Type: Journal Article | Journal: Genome announcements | Year: 2016
Echovirus 18 is a member of the genus Enterovirus, family Picornaviridae, which can cause meningitis in children. Here, we report the echovirus 18 complete genome sequence, which was isolated from the cerebrospinal fluid of a child with aseptic meningitis in Hebei Province, China.
PubMed | St Petersburg Pasteur Institute, National Key Discipline of Pediatrics Capital Medical University and Chinese National Institute for Communicable Disease Control and Prevention
Type: | Journal: Scientific reports | Year: 2016
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.