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In order to optimize the undergraduate teaching methods and improve students' comprehensive competitiveness, this study explored the scientific research training methods of medical laboratory undergraduates during medical internship. On the premise of ensuring that students carry out clinical practice according to the internship plan, the research group leads students to carry out scientific research training in their spare time. The scientific research training was divided into two stages. In the first stage, on the basis of informed consent and independent choice, the students in the control group were trained by self-regulated learning and teachers' question answering, while the students in the experimental group were trained by the way of centralized scientific research lectures and scientific research practice. In the second stage, all the students were in independent research and exploration under the guidance of teachers within 5 months. The results showed that in the process of independent research, the time of topic selection in the experimental group [(3.5±1.1) days] was significantly shorter than that in the control group [( 5.4 ± 1.9) days], and the time of topic design in the experimental group [(12.2±2.5) days] was significantly shorter than that in the control group [(14.6±3.1) days]. It shows that carrying out scientific research training in the medical internship stage of undergraduates is helpful to increase the efficiency of students' later independent research and accelerate the process of independent research.
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Objective:To provide consistent data basis for the application of reference intervals for children blood cell analysis in different testing systems.Methods:According to the requirements of American Institute for Clinical and Laboratory Standardization (CLSI) EP9-A3 document, 45 samples were collected and Sysmex XN20-A1 were used as reference system. Beckman DxH800, Siemens ADVIA 2120i, and Mindray BC5310 were comparison systems. Complete blood count and leukocyte classification were performed by four systems. The outliers of the detection results were tested by the generalized extreme student deviate (ESD) method. An optimal regression model was selected by scatter diagram, deviation diagram and frequency distribution diagram, which was used to fit the regression equation and calculate the deviation at the medical decision level and reference interval. The acceptable range for blood count deviation was cited from the Analytical Quality Specifications for Routine Tests in Clinical Hematology. The acceptable range for leukocyte classification was based on the EQA program of Royal College of Pathologists of Australasia (RCPA).Results:After the outliers were deleted, the scatter plot showed a linear relationship between the reference system and the three comparison systems. The deviation plot showed that the differences were variable. Deming regression or Passing-Bablok regression was selected according to the data distribution. The determination coefficient R2 of reference system and three comparison systems ranged from 0.95 to 0.99 in blood count and leukocyte classification. At the upper and lower limits of the reference interval, the deviations between XN-20A1 and ADVIA 2120 system were all acceptable, except for MONO# at 0.12×10 9/L. The deviations of all parameters at medical decision level were within acceptable ranges. The lower limit of PLT is partially unacceptable at the level of medical decision related to treatment and prognosis. Conclusions:The results of complete blood count and leukocyte classification in reference system and the comparison system had good consistency within the children′s reference interval. Our study provided a scientific basis for the feasibility of adopting a unified reference interval for different detection systems.
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Objective:To investigate the clinical significance and the diagnostic value of detecting kidney injury biomarkers in urine and serum of children with Henoch-Sch?nlein purpura nephritis (HSPN).Methods:A total of 216 children with untreated HSPN, who were admitted in Beijing Children′s Hospital of Capital Medical University from January 2018 to December 2019, were recruited in this retrospective study. Two hundred and sixteen healthy children were selected as the healthy control group. We determined the levels of six biomarkers of kidney injury, including transferrin (TRF), immunoglobulin (IgG), microalbumin (mAlb), alpha-1 microglobulin (α1-MG), N-acetyl-β-D-glucosaminidase (NAG) in urine and cystatin C (CysC) in serum. The data from the two groups were analyzed, the diagnostic value of each biomarker was evaluated and a logistic regression model for the diagnosis of HSPN was established. In addition, 60 children with HSPN, who were admitted to our hospital from November 2021 to February 2022 and 60 healthy children, who underwent healthy check up in the same period were included to validate the diagnostic performance of the established logistic model. Receiver operating characteristic (ROC) curve was used to analyze the diagnostic value of each biomarker.Results:The urine levels of TRF, IgG, mAlb, α1-MG and NAG and the serum level of CysC were significantly higher in the HSPN group than those in healthy control group (all P<0.05). The area under the ROC curve (AUC) of TRF, IgG, mAlb, α1-MG, NAG and the serum levels of CysC was 0.749, 0.719, 0.810, 0.648, 0.828 and 0.790 (all P<0.05). Logistics regression analysis showed that IgG, mAlb and TRF were the three diagnostic determinants of HSPN ( OR=1.083, 1.105, 1.704,all P<0.001), and the AUC was 0.916 of the established logistic model based on these three biomarkers. The sensitivity was 87.4% and the specificity reached 96.2%. The logistic model was validated by independent cohorts, and the AUC was 0.973, the sensitivity was 95.0% and the specificity was 98.3%. Conclusions:The levels of urine TRF, IgG, mAlb, α1-MG, NAG and serum CysC were higher in children with HSPN. The established logistic regression model based on three biomarkers including IgG, mAlb and TRF in this study has satisfactory clinical value in diagnosing HSPN in children.
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Objective:To establish the biology reference interval (RI) of peripheral blood procalcitonin (PCT) for children between 3 days and 6 years old in China.Methods:Totally 3 353 reference individuals with apparent health or no specific diseases were recruited in 18 hospitals throughout the country during October 2020 to May 2021. Reference individuals were divided into four groups: 3-28 days, 29 days - 1 year, 1-3 years and 4-6 years. Vein blood or capillary blood were collected by percutaneous puncture from every reference individual. The PCT level in serum and the capillary whole blood were assayed by Roche Cobas e601 and Norman NRM411-S7 immunoanalyzer. Outliers were deleted and 95th percentiles of every group were provided as RIs. Man-Whitney U test or Kruskal-Wallis test were used performed to assess the difference among different gender, age or method groups. Results:The difference of PCT distribution between male and female is not statistically significant, but the difference between serum and capillary whole blood is statistically significant. The differences between age groups are significant too. For Roche e601, serum PCT RI of 3-28 days group is <0.23 μg/L, 29 days - 6 years are <0.11 μg/L. For NRM411, Serum PCT RI of 3-28 days group is <0.21 μg/L, 29 days - 1 year: <0.09 μg/L, 1 - 6 years: <0.10 μg/L. For whole blood PCT, RI of 3-28 days group is <0.26 μg/L, 29 days - 6 years is <0.15 μg/L.Conclusions:Serum and capillary whole blood PCT have different RIs, however, capillary whole blood PCT testing is valuable in pediatric application. Children in 3-28 days show higher PCT levels than other age group. To establish the RIs and understand the differences among different groups are essential for the interpretation and clinical application of peripheral blood PCT testing results.
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Objective:To explore the reliability of preoperative diagnosis of low-grade infectious nonunion using haematological testing and radioisotope scanning (bone 3-phase image).Methods:A retrospective study was conducted of the 265 patients with bone nonunion who had been treated at Department of Orthopaedics, The Sixth People’s Hospital Affiliated to Shanghai Jiaotong University and at Department of Orthopaedics, The Eighth People’s Hospital Affiliated to Shanghai Jiaotong University from June 2010 to June 2018.They were 151 males and 114 females, aged from 19 to 64 years (average, 39.7 years).The nonunions occurred mainly at the tibia (113 cases) and the femur (72 cases).The preoperative results of their white blood cell count (WBC), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and radioisotope scanning were recorded.Taking the intraoperative pathological observations as the gold standards, the sensitivity, specificity, area under curve (AUC) of receiver operator characteristic (ROC) and Youden index were statistically analyzed respectively for every preoperative haematological tests and radioisotope scanning as well as for different combinations of the radioisotope scanning and one or more haematological tests.Results:Compared with the pathological observations, the radioisotope scanning showed a sensitivity of 80.7%, a specificity of 73.3%, an AUC of 0.770 and a Youden index of 0.540.In the combinations of radioisotope scanning and one haematological test, that of radioisotope scanning and CRP produced the largest AUC of 0.683, a sensitivity of 98.0%, a specificity of 70.3%, and a Youden index of 0.848.In the combinations of radioisotope scanning and 2 haematological tests, that of radioisotope scanning and WBC and ESR produced the largest AUC of 0.895, a sensitivity of 94.3%, a specificity of 67.3%, and a Youden index of 0.616 and all the 3 ones yielded an AUC of more than 0.880.The combination of radioisotope scanning and all the 3 haematological tests produced a sensitivity of 96.5%, a specificity of 79.7%, an AUC of 0.925 and a Youden index of 0.762.Conclusion:Combination of haematological testing and radioisotope scanning can be a reliable preoperative diagnosis of low-grade infection nonunion.
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Objective:To investigate the distribution of fungal species and their sensitivity to antifungal drugs in children with invasive fungal infections.Methods:All the fungal strains primarily isolated from the sterile parts of children in Beijing Children′s Hospital, Capital Medical University from January 2010 to December 2016 were analyzed.The sensitivity of strains to 5-Fluorocytosine, Fluconazole, Amphotericin B, Itraconazole and Voriconazole was tested using ATB-FUNGUS 3 yeast drug sensitivity test strip in accordance with the standards of Clinical and Laboratory Standards Institute M27-A2.Statistical analysis of data was performed using WHONET 5.6 software.Results:Among 236 fungi isolated from aseptic samples, 64.0% (151 strains) were from blood, 22.9%(54 strains) from cerebrospinal fluid, 3.8%(9 strains) from bone marrow, 3.8%(9 strains) from ascites, 3.4%(8 strains) from pleural effusion and 2.1%(5 strains) from tissues.The top 3 dominant species detected in the 236 strains of fungi were Candida spp.(175 strains, 74.2%), Cryptococcus neoformans (31 strains, 13.1%), and Saccharomyces spp.(9 strains, 3.8%). Among the Candida spp., the main isolates were Candida albicans (107 strains, 61.1%), Candida parapsilosis (33 isolates, 18.9%), and Candida tropicalis (13 isolates, 7.4%). Rare fungi of Penicillium marneffei, Exophiala spp.and Rhizopys spp.were also detected. Candida spp.was 100% sensitive to Amphotericin B. Cryptococcus neoformans was 100% sensitive to Fluconazole, Voliconazole and Amphotericin B. Conclusions:The most common strain isolated from pediatric patients with invasive fungal infections is Candida spp., especially Candida albicans. Cryptococcus neoformans causes central nervous system and systemic disseminated infections that can′t be ignored.Amphotericin B has higher antibacterial activity against Candida spp.and Cryptococcus neoformans.Separation of species of invasive fungal infections and monitoring of drug resistance in children should be strengthened to effectively control invasive fungal infections and facilitate rational use of antifungal drugs.
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Objective:To investigate the molecular characteristic and antimicrobial resistance of Staphyloco- ccus aureus ( S. aureus) isolated from children with pneumonia, in order to provide the evidence for clinical diagnosis and treatment. Method:s The S. aureus strains isolated from children diagnosed as S. aureus pneumonia in the Beijing Children′s Hospital, Capital Medical University, between January 2016 and March 2017 were collected.Methicillin-resistant S. aureus(MRSA)and Methicillin-susceptible S. aureus(MSSA)were identified using the cefoxitin disc method and the detection of the mecA gene. S. aureus isolates were characterized by multilocus sequence typing (MLST) and Staphylococcal protein A (spa) typing, and MRSA strains were characterized by Staphylococcal chromosome cassette (SCC mec) typing.Besides, 21 superantigens (SAgs) genes, panton-valentine leucocidin (PVL) genes, adhesion genes fnbb and cna were detected by PCR; E-test was used to detect in vitro drug sensitivity of 14 antibiotics. Result:s A total of 42 S. aureus were collected, and 21 isolates were MSSA, the same to MRSA, while MSSA strains had relatively dispersed typing, with ST25-t078 (14.2%) as the most common one.ST59-SCC mecⅣa-t437 (71.4%) were the most predominant clones of MRSA.Of the 42 isolates, 36 strains (85.7%) had at least 1 superantigen gene, and sek- seq (21.4%) was the main virulence genotype.The ratio of pvl in MRSA strains (52.3%)was significantly higher than that in MSSA strains (14.2%), while the detection rate of fnbB and cna in MRSA(9.5%, 9.5%) was significantly lower than that in MSSA(42.8%, 47.6%), and the differences were statistically significant (all P<0.05). Ninety point four percent (38/42 strains) of the S. aureus isolates were multidrug resistant. Conclusions:In children with S. aureus pneumonia, MRSA has a high detection rate, and its dominant clonotype is ST59-SCC mecⅣa-t437.The pre-valence of superantigen genes and the multidrug resistant rate of S. aureus are relatively high.MRSA strains often carry pvl, while MSSA strains usually carry fnbB and cna gene.
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Objective Investigate the effect of neonatal hyperbilirubinemia on the detection of HBsAg by chemiluminescence and its elimination methods.Methods Case control study.The HBsAg in human serum was detected in 200 cases of hyperbilirubinemia neonates who were hospitalized in Beijing Children's Hospital,Capital Medical University from July 2015 to May 2016 and whose serum total bilirubin level exceeded 200 μmol/L.The positive serum was further detected by 16 200×g high-spoed centrifugation or blue light irradiation for 8 hours,and the results of re-assay of HBsAg were recorded.The retest positive serum wastested for HBV DNA load and checked the results of their mother's examination in HBV.136 adult serum samples with total bilirubin levels exceeding 200 μmol/L in the Peking University First Hospital,were taken as reference to compare the influence of hyperbilirubinemia between adults and newborns on the determination of HBsAg.Results The median level of serum total bilirubin in neonates was 259.0 μ mol/L (226.5,312.5);median level of indirect bilirubin 244.1 μmol / L(212.5,295.8).Median level of serum total bilirubin in adults 356.4 μmol/L(295.9,435.1);median level ofindirect bilirubin 137.1 μmol/L (107.8,172.7).The HBsAg test was negative in adults,11 cases (5.5％) were positive in newborns,their" HBV DNA load was less than＜100 IU/ml.Among them,9 have inoculated hepatitis B vaccine and 2 were unknown.10 of 11 mothers of infants were healthy and 1 was positive for HBsAg,HBeAb,HBcAb.2 of the 11 positive specimens turned negative of HBsAg after high-speed centrifugation.In addition to high speed centrifugation,4 cases turned negative after blue light irradiation.5 cases remained positive after high speed centrifugation and blue light irradiation.Conclusions Neonatal hyperbilirubinemia,which is different from that of adults,is mainly caused by indirectly bilirubin increased,which is one of the main reasons for false positive detection of HBsAg by chemiluminescence in neonates.High-speed centrifugation and blue light irradiation can eliminate the influence of serum indirect bilirubin on the detection of HBsAg to the greatest extent.
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Objective To investigate the epidemiology of pathogens causing acute respiratory in-fections in children in Beijing from December 2016 to February 2018. Methods Clinical data of 34665 ca-ses of acute respiratory infections in Beijing Children's Hospital from December 2016 to February 2018 were reviewed. Indirect immunofluorescence antibody test ( IFAT) was performed to detect IgM antibodies against eight common respiratory pathogens including respiratory syncytial virus ( RSV) , influenza virus A ( IFA) , influenza virus B (IFB), parainfluenza virus (PIV), adenovirus (ADV),Mycoplasma pneumonia (MP), Chlamydia pneumonia (CP) and Legionella pneumophila (LP). SPSS19. 0 software was used for statistical analysis. Results In the 34665 cases, 50. 45％ children were infected with at least one kind of respiratory pathogen. There were 56. 11％ (10309/18372) in mild outpatient group and 44. 06％ (7179/16293) in severe inpatient group. IFB was the most prevalent pathogen with a positive rate of 36. 56％ and co-infection rate of 9. 78％. IFB and MP co-infection was more common. Most of RSV strains were detected in children under 1 year of age. The positive rates of IFA, IFB and PIV peaked in patients at ages of 4-5 years. The rates of ADV, MP, CP and LP infections increased with age. IFB, MP, IFA and RSV were more prevalent in winter and spring. Other pathogens caused sporadic cases throughout the year. There were significant differences in the detection rates of IgM antibodies against the eight respiratory pathogens between the mild and severe groups (P=0. 00). Conclusions This study analyzed the epidemiology of respiratory pathogens in Beijing from December 2016 to February 2018 through reviewing test results of IgM antibodies against eight common respiratory pathogens in children with acute respiratory infections. It might be conductive to the prevention of antimicrobial abuse and reduction of economic burden to families.
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In order to improve the core competitiveness and the comprehensive ability of laboratory medicine students,we implemented the clinical teaching mode of evidence-based laboratory medicine in the department of Clinical Laboratory Center of Beijing Children's Hospital,Capital Medical University.This study relied on the platform of National Center for Children's Health,which had abundant case resources and excellent expert team.This study started with the clinical problem,summarized the scientific problem,and carried out teaching activities around the scientific problem.By guidance of the teachers,students used evidence-based medicine methods(clinical case information collection,literature reading,interviews with clinical experts and experimental data collection)to solve the clinical problem.Through research cases,evidence-based medicine methods,clinical thinking and scientific thinking were imparted to students,which can help them integrate theoretical knowledge with clinical practice,and improve learning efficiency,training in clinical thinking and scientific research innovation ability,so as to enhance core competitiveness.
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Objective@#To study the clinical and molecular characteristics of Staphylococcus aureus(S.aureus ) isolated from neonates of Beijng Children′s Hospital.@*Methods@#The clinical information of S. aureus infection in newborns of Beijing Children′s Hospital from February 2016 to January 2017 was collected.The molecular biological characteristics of S. aureus isolates were detected.Methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus(MSSA)were identified, using the cefoxitin disc method and the detection of the mecA gene.Multilocus sequence typing(MLST)and spa typing were analyzed using the PCR, and the staphylococcal chromosomal cassette mec(SCCmec) type was analyzed for the MRSA isolates.Eleven adhesion gene and three virulence genes(pvl, psma, hlα )were also detected by PCR.Antimicrobial susceptibility testing was performed by agra dilution method or E-test method.@*Results@#The total of 57 cases of neonatal S. aureus infection were collected during the study.The most common clinical diagnosis was 38 cases (66.7%) of pneumonia and 28 cases (49.1%) of skin infection syndrome (SSTI). There were 31 cases (54.4%) with MRSA infection and 26 cases (45.6%) with MSSA infection.The proportion of SSTI in the MRSA group (64.5%) and the infection of more than 2 sites (61.3%, 19/31) were significantly higher than those in the MSSA group (30.8%, 8/26 and 23.1%, 6/31). There were 16 MLST types and 29 spa types, the most common ones were ST59 (40.4%) and t437 (33.33%), respectively.The most common popular clones of MRSA and MSSA were ST59-SCCmecIVa-t437 (54.8%) and ST22-t309, respectively(11.5%). The sdrE carrying rate of MRSA was higher than that of MSSA, while the sdrD and cna carrying rates were lower than those of MSSA (P<0.05). The other adhesion and virulence gene carrying rates were not significantly different between the two strains.The multi-drug resistance rate of all strains was 61.4%(35/57). Except for lactam antibiotics, the most common resistant phenotypes of MRSA and MSSA were ERY-CLI, accounting for 74.2% and 26.9%, respectively.@*Conclusion@#The main types of neonatal S. aureus infection in our hospital were pneumonia and SSTI.SSTI and multi-site infections of MRSA infection are more common.MRSA and MSSA isolates have clonal dissemination characteristics.The most common clones are ST59-SCCmecIVa-t43 and ST22-t309, which show no significant differences in the status of carrying virulence factors between them.The multi-drug resistance rate of neonatal S. aureus isolates is higher.
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In order to improve the core competitiveness and the comprehensive ability of laboratory medicine students, we implemented the clinical teaching mode of evidence-based laboratory medicine in the department of Clinical Laboratory Center of Beijing Children's Hospital, Capital Medical University. This study relied on the platform of National Center for Children's Health, which had abundant case resources and excellent expert team. This study started with the clinical problem, summarized the scientific problem, and carried out teaching activities around the scientific problem. By guidance of the teachers, students used evidence-based medicine methods (clinical case information collection, literature reading, interviews with clinical experts and experimental data collection) to solve the clinical problem. Through research cases,evidence-based medicine methods, clinical thinking and scientific thinking were imparted to students, which can help them integrate theoretical knowledge with clinical practice, and improve learning efficiency, training in clinical thinking and scientific research innovation ability, so as to enhance core competitiveness.
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In order to enhance the comprehensive ability,scientific research consciousness and scientific research skills of laboratory medicine students,the clinical laboratory center of Beijing Children's Hospital carried out the exploration for strengthening the scientific research ability of laboratory medicine students in the implementation of scientific research projects.Depending on the platform of National Center for Children's Health,the clinical laboratory center of Beijing Children's Hospital used patient resources and top research facilities to provide comprehensive trainings for students who volunteered to take part in this project with the goal of offering more opportunities for further study and employment to them.Teachers can impart the ideas,thoughts and skills of scientific research to the students through the training,which can help them to improve their core competitiveness by combining the theoretical knowledge and practical work,developing the innovative thinking and improving the ability in scientific research innovation and practice.
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Objective To investigate the molecular characteristics,virulence genes and antimicrobial susceptibility to Staphylococcus aureus strains isolated from children with skin and soft tissue infections (SSTIs) in Beijing.Methods A total of 52 Staphylococcus aureus isolates were collected from children with SSTIs in Beijing Children's Hospital,Capital Medical University,and the clinical data were collected and analyzed.Methicillin-resistant Staphylococcus aureus(MRSA) and methicillin-susceptible Staphylococcus aureus(MSSA) were identified by using the cefoxitin disc method and the detection of mecA gene.Multilocus sequence typing (MLST) and staphylococcal protein A (spa) typing were analyzed by the PCR method,and the staphylococcal chromosomal cassette mec (SCCmec) type was analyzed for the MRSA isolates.The pvl,eta,etb,tsst-1 and hlg genes were also detected by PCR.The susceptibility strains to 16 antibiotics were evaluated by using the agar dilution method.Results A total of 52 Staphylococcus aureus SSTIs patients,30 with MRSA infections and 22 with MSSA infections were included in the study.There were 23 patients (44.2％) less than 1 year old.The most frequent infections were the newborn omphalitis (12/52 strains,23.1％)and abscess(11/52 strains,21.2％).ST59-MRSA-SCCmecⅣa-t437 was the most predominant clones of MRSA isolates.Among the MSSA isolates(14/30 strains,46.7％),no significant epidemic clone was found.Ten sequence types (STs) and 14 spa types were identified in MSSA,and the most common types were ST22(6/22 strains,27.3％)and t309 (5/22 strains,22.7％),respectively.Notably,the multidrug resistant rates of MRSA and MSSA isolates were all ＞ 85％.The percentages of the Staphylococcus aureus SSTIs strains resistant to Erythromycin,Penicillin,Chloramphenicol and Clindamycin were 100.0％,94.2％,69.2％ and 63.5％,respectively.The tested isolates were susceptible to Trimethoprim/Sulfamethoxazole,Mupirocin,Fusidic acid,Tigecycline,Linezolid and Vancomycin.The pvl gene's positive rate was 40.4％,and no significant difference between MRSA and MSSA was observed (P ＞ 0.05).Eta and etb genes were detected in 2 patients with staphylococcal scalded skin syndrome.Conclusions The Staphylococcus aureus SSTIs strains are most frequently isolated from newborn omphalitis and abscess in Beijing.The multidrug resistant rate is relatively high,so the erythromycin and clindamycin should not be preferred in empiric treatment of children with Staphylococcus aureus SSTIs.The prevalence of pvl gene is 40.1％.ST59-MRSA-SCCmecⅣa-t437 is the common clone of MRSA,while the MSSA isolates have a more diverse genetic background.
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Objective To investigate the distribution and antimicrobial resistance profile of the common pathogens isolated during the period from 2009 to 2015.Methods All the bacterial strains isolated from pediatric inpatients in Beijing Children's Hospital during the period from 2009 to 2015 were analyzed. Antimicrobial susceptibility was determined by disk diffusion method and Phoenix 100 Automated Microbiology System. Results were analyzed according to the guidelines of CLSI (2014) using WHONET 5.6 software.Results The total strains were 26630. The most common gram-positive isolates were Streptococcus pneumoniae,Staphylococcusaureusand coagulase-negative Staphylococcus (CNS), while the most frequently isolated gram-negative microorganisms were Klebsiella spp.,Pseudomonas aeruginosa and Escherichia coli. The prevalence of S. pneumoniae was up to 25.7 % (4101/15973) in all respiratory tract specimens. About 50.2 % of the S. pneumoniae isolates were not susceptible to penicillin. The prevalence of methicillin-resistant strains was 20.6 % in S. aureus (MRSA) and 87.8 % in coagulase negative Staphylococcus (MRCNS) on average. The prevalence of MRSA increased from 11.1 % in 2009 to 29.8 % in 2015. No S. pneumoniae or staphylococcal strains were found resistant to vancomycin or linezolid. The Enterococcus strains were still highly susceptible to vancomycin and linezolid. Overall 0.3 % of the Enterococcus faecium isolates were resistant to vancomycin. The extended-spectrum beta-lactamases (ESBLs) producing strains accounted for 71.4 % -78.1 % of E. coli and 65.1 % - 76.9 % of K. pneumoniae isolates. The carbapenem-resistant E. coli and K. pneumoniae were reported for the first time in 2010, but in 2014, the strains resistant to carbapenems had increased to more than 7 % in E. coli, and higher than 20 % in K. pneumoniae. In 2015, up to 27.7 % and 25.7 % of P. aeruginosa isolates were resistant to imipenem and meropenem, respectively, and 59.9 % of the A. baumannii isolates were resistant to imipenem and meropenem. Beta-lactamase was positive in 46.3 % of the H. influenzae isolates. Conclusions MRSA and the carbapenem-resistant strains of E. coli,K. pneumoniae and A. baumannii are still on the rise in pediatric inpatients, which poses a serious threat to clinical practice and implies the importance of strengthening infection control.
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Objective To explore the diagnostic value of five infection markers in bloodstream infection.Methods Randomly selected 110 bloodstream infection patients with positive blood cultures and 30 bacterial infection patients with negative blood cultures.Blood was simultaneously drawn with blood cultures;the complete blood count and C-reactive protein (CRP) levels were measured.The white blood cell count (WBC),neutrophil count (NEU),lymphocyte count (LMY),CRP level and neutrophil-lymphocyte count ratio (NLCR) were compared between the two groups.Results The levels of WBC,NEU,NLCR and CRP in bloodstream infection group were significantly higher than those in control group (P＜0.05),while LYM was significantly lower than that in control group (P＜ 0.05).Among these five infection markers,the area under the receiver operating characteristic curve (ROC-AUC) was the highest for NLCR (0.808) and LMY (0.756);when the cutoff value for NLCR was ＞9.33,sensitivity was 63.6％,specificity was 93.3％;and the cutoff value for LYM was ≤0.97,sensitivity was 58.2％,specificity was 86.7％.Furthermore,the NLCR of patients with gram-negative bloodstream infection was higher than those in patients with gram-positive bloodstream infection.NLCR showed important clinical significance in distinguishing strains of different bloodstream infections.Conclusions NLCR is the better predictors than routine parameters in diagnosing bloodstream infection.
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The pediatric reference intervals in clinical laboratory play an important role in diagnosis of illness,therapeutic monitoring,prediction of prognosis and health evaluation.Compared with establishing reference interval for adults,there are more challenges to establish pediatric reference intervals.Therefore,the procedure and key technologies of direct method and indirect method are stated based on the characteristics of children population and pediatric,by which to define,transfer and validate pediatric reference intervals.This study will provide systematically methodological ideas for clinical laboratories to establish pediatric reference intervals.
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Objective To study the molecular characteristics of the Staphylococcus aureus isolated from the intensive care units (ICUs) of children's hospital.Methods From January 2016 to December 2016,a total of 39 S.aureus strains were collected and identified from various clinical specimens that were obtained from patients who were confined in the neonatal and pediatric ICUs of Beijing Childreng Hospital.Methicillin-resistant S.aureus (MRSA) and methicillin-susceptible S.aureus (MSSA) were identified using the cefoxitin disc method and the detection of the mecA gene.Multilocus sequence typing (MLST) and spa typing were analyzed using the PCR,and the staphylococcal chromosomal cassette mec (SCCmec) type was analyzed for the MRSA isolates.Twenty-one superantigen genes and the Panton-Valentine leukocidin (pvl) gene were also detected by PCR.Their susceptibility to 12 antibiotics was evaluated using the E-test method.The differences in prevalence of virulence genes and antimicrobial resistance were compared between the MRSA and MSSA isolates by Fisherg exact test.Results All the S.aureus strains were isolated from secretion inside the airway of pneumonia (including severe pneumonia),the blood of patients with bacteremia,and exudate of skin and soft tissue infections.ST59-SCCmecⅣa-t437 (55.6％) and ST398-t571 (28.6％) were the most predominant clones of MRSA and MSSA,respectively.Of the 39 isolates,26 strains (66.7％) had at least one superantigen gene,and seb (38.5％),sek (30.8％),and seq (20.5％) were the most common genes;seb-sek-seq (18.0％) was the main virulence genotype.The pvl geneg positive rate was 25.6％,and no significant difference between MRSA and MSSA was observed (P ＞ 0.05).Notably,79.9％ of the S.aureus isolates were multidrug resistant,and 94.9％,53.8％,and 51.3％ of the isolates were resistant to erythromycin,clindamycin,and chloramphenicol,respectively.The tested isolates were susceptible to trimethoprim/sulfamethoxazole,rifampicin,and vancomycin.Conclusions The S.aureus strains from the ICUs of childreng hospital were isolated from the secretion inside the airway of pneumonia (including severe pneumonia),the blood of patients with bacteremia,and exudate of skin and soft tissue infections.ST59-SCCmecⅣa-t437 (55.6％) and ST398-t571 (28.6％) were the common clones of MRSA and MSSA,respectively.The prevalence of superantigen genes and the multidrug resistant rate were relatively high.
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Objective To analyze the distribution and antibiotic resistance profile of Haemophilus influenzae strains isolated from children for better antibiotic use.Methods The clinical and laboratory data concerning 350 strains ofH.influenzae were collected and analyzed retrospectively from 2014 to 2015 in our hospital,including pathogen source,production of beta lactamases and antimicrobial susceptibility.Antimicrobial susceptibility testing was carried out by using disk diffusion method.The results were interpreted according to the breakpoints of the Clinical and Laboratory Standards Association (CLSI) in 2014,and analyzed using WHONET 5.6 software.Results H.influenzae infection was more common in infants and young children.The prevalence of beta lactamase was 53.1％ in H.influenzae isolates.The H.influenzae isolates showed the highest resistance rate to trimethoprimsulfamethoxazole (76.9％),but relatively high susceptible rate to ciprofloxacin (99.1％),ceftizoxime (98.9％),chloramphenicol (95.4％),tetracycline (88.3％),amoxicillin-clavulanic acid (87.7％),cefuroxime (74.9％),azithromycin (65.4％),cefaclor (56.6％) and ampicillin (46.0％).All these H.influenzae strains were susceptible to ceftriaxone and meropenem.Conclusions Beta-lactamases are highly prevalent in the H.influenzae strains isolated from children,which is the main mechanism underlying ampicillin resistance in H.influenzae.Ampicillin is therefore not appropriate for first-line treatment ofH.influenzae infections.The H.influenzae strains are highly resistant to trimethoprim-sulfamethoxazole.In addition to beta-lactams,ciprofloxacin is the most active agent against H.influenzae strains,followed by chloramphenicol.
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Objective To investigate the clinical characteristics and antibiotic resistance of the bloodstream infections due to NDM-1 producing Klebsiella pneumoniae in children.Methods The nonduplicate carbapenem-resistant Klebsiella pneumoniae (CRKp) strains isolated from blood samples were collected in Beijing Children's Hospital from January 2011 to August 2014.Antimicrobial susceptibility was tested with broth microdilution method.PCR amplification and DNA sequencing were conducted targeting blaNDM-1 genes.Medical records were reviewed and analyzed.Results Of the 52 CRKp strains,blaNDM-1 gene was detected in 28 strains.All NDM-l-producing strains were multidrug-resistant.All the 28 isolates were resistant to penicillin,cephalosporins,piperacillin-tazobactam,and imipenem.More than 75.0％ of these NDM-1-producing strains were resistant to aztreonam,trimethoprim-sulfamethoxazole,gentamicin,and meropenem (92.9％,26/28).NDM-1-producing isolates had higher carbapenem MICs than non-NDM-1-producing isolates.Most (82.1％,23/28) of the NDM-1-producing isolates were isolated from hematology-oncology ward.The most common underlying disease was hematologic malignancy (78.6％,22/28).Febrile neutropenia was found in 20 (71.4％) patients.No difference was found between NDM-1-producing and non-NDM-1-producing CRKp infection in terms of repeated hospitalization (P=0.202),prior antibiotic use (P=0.615),underlying diseases (P=0.856),and deep venous catheter (P=0.099).After the susceptibility results were available,37 patients received carbapenembased combination regimen.The mortality did not show difference between NDM-1 producing CRKp infections and non-NDM-1-producing CRKp infections,7.1％ (2/28) vs.12.5％ (3/24),P=0.625.Conclusions The NDM-1 carbapenemase producing Klebsiella pneumoniae is emerging in this hospital.NDM-1-producing strains are resistant to multiple antimicrobial agents,associated with higher carbapenem MIC value.However,no difference was found in the clinical features between the bloodstream infections due to NDM-1-producing strain and those due to non-NDM-1-producing strains.