Quan Lu

Capital Medical University, Beijing, Beijing Shi, China

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Publications (25)29.41 Total impact

  • Article: [Molecular characteristics of methicillin resistant Staphylococcus aureus isolated from Chinese children].
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    ABSTRACT: To investigate the molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) isolates from Chinese children in seven cities. A total of 134 MRSA isolates were collected from nine hospitals. Multilocus sequence typing and spa typing were analyzed by polymerase chain reaction (PCR), and staphylococcal chromosomal cassette mec (SCCmec) type was analyzed by multiplex PCR. The Panton-Valentine leukocidin (pvl) gene was also detected. Most MRSA strains were isolated from pneumonia and skin and soft tissue infection (SSTIs) patients, accounting for 82.1%. Overall, 16 sequence types (STs) were obtained, and CC59 (51.7%) was found to be the most prevalent, which included ST 59 and ST 338, followed by ST239 (16.4%). SCCmec types II, III, IV, and V were also identified in the current study. SCCmec type IV was the most predominant type at 50.0%, followed by SCCmec type V at 23.9% and III at 23.9%. SCCmec subtypes IVa, IVc, and IVg were found among SCCmec type IV strains, whereas IVa was the main subtype at 77.6%. Twenty-six spa types were also identified, among which the predominant type was t437 (47.8%). The prevalence of pvl genes and the SCCmec type of strain was relevant, and the pvl gene positive rate was higher in SCCmec type IV and V-type strains than in SCCmec type II and III strains (58.6% vs. 14.3%, P < 0.05); there was a significant difference between them. In the strains isolated from pneumonia and SSTIs, ST59-MRSA-IVa(t437) was the predominant clone. There were five clones detected from the strains isolated from septicemia, with ST59-MRSA-IVa(t437) and ST59-MRSA-V(t437) as the main clones (57.1%). Various predominant clones existed in different regions. ST59-MRSA-IVa(t437) was the prevalent clone in the Guangzhou, Beijing, Chongqing, and Shenzhen areas, whereas ST239-MRSA-III(t037) was the prevalent clone in the Shanghai area. Fifty percent of the isolates from the Wenzhou area belonged to ST910-MRSA-V(t318), whereas three clinical strains isolated from the Shenyang region belonged to three different types. The results indicate that MRSA isolates from Chinese children are largely associated with the ST59-MRSA-IV(t437) and ST239-MRSA-III(t037) clones. These two may belong to community-acquired MRSA and hospital-acquired ones, respectively. Different prevalent clones were detected in different diseases and different regions. Therefore, there is a need to conduct further research on clinical isolates, which can guide the choice of antibiotic treatment and the examination of MRSA prevalence.
    Zhonghua er ke za zhi. Chinese journal of pediatrics 01/2012; 50(1):38-44.
  • Article: Spread of methicillin-resistant Staphylococcus aureus between the community and the hospitals in Asian countries: an ANSORP study.
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    ABSTRACT: Methicillin-resistant Staphylococcus aureus (MRSA) is highly prevalent in hospitals in many Asian countries. Recent emergence of community-associated (CA) MRSA worldwide has added another serious concern to the epidemiology of S. aureus infections. To understand the changing epidemiology of S. aureus infections in Asian countries, we performed a prospective, multinational surveillance study with molecular typing analysis. We evaluated the prevalence of methicillin resistance in S. aureus isolates in CA and healthcare-associated (HA) infections, and performed molecular characterization and antimicrobial susceptibility tests of MRSA isolates. MRSA accounted for 25.5% of CA S. aureus infections and 67.4% of HA infections. Predominant clones of CA-MRSA isolates were ST59-MRSA-SCCmec type IV-spa type t437, ST30-MRSA-SCCmec type IV-spa type t019 and ST72-MRSA-SCCmec type IV-spa type t324. Previously established nosocomial MRSA strains including sequence type (ST) 239 and ST5 clones were found among CA-MRSA isolates from patients without any risk factors for HA-MRSA infection. CA-MRSA clones such as ST59, ST30 and ST72 were also isolated from patients with HA infections. Our findings confirmed that MRSA infections in the community have been increasing in Asian countries. Data also suggest that various MRSA clones have spread between the community and hospitals as well as between countries.
    Journal of Antimicrobial Chemotherapy 02/2011; 66(5):1061-9. · 5.07 Impact Factor
  • Article: [Improve multicenter investigation of emerging infectious diseases in children].
    Zhonghua er ke za zhi. Chinese journal of pediatrics 10/2010; 48(10):721-3.
  • Article: Clinical impact of methicillin resistance on outcome of patients with Staphylococcus aureus infection: a stratified analysis according to underlying diseases and sites of infection in a large prospective cohort.
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    ABSTRACT: This study was conducted to identify the predictors of mortality and to evaluate the impact of methicillin resistance on outcome in patients with Staphylococcus aureus infection according to underlying conditions and type of infection. An observational cohort study including 4949 patients with S. aureus infection was conducted. We compared data from patients with MRSA infection with those with MSSA infection. The 30-day mortality rate of MRSA group was significantly higher than that of MSSA group (15.6% vs. 6.2%, P < 0.001). However, MRSA infection was not found to be independent risk factor for mortality after adjusting for other variables (OR = 1.03, 95% CI = 0.80-1.32). When we analyzed patients with S. aureus bacteremia (n = 709), MRSA infection was found to be significantly associated with mortality in multivariate analysis (Adjusted OR = 1.69, 95% CI = 1.15-2.49). When the 30-day mortality rates were compared according to underlying diseases, the 30-day mortality rate of MRSA group was significantly higher than that of MSSA group in patients with malignancy or renal diseases. MRSA infection was also found to be one of the independent risk factors for mortality in patients with malignancy (adjusted OR = 1.69, 95% CI = 1.06-2.70) and in those with renal disease (adjusted OR = 1.70, 95% CI = 1.0-2.89), after adjustment for host variables. Methicillin resistance adversely affected the outcome of patients with S. aureus infection, in patients with cancer or renal disease and in those with S. aureus bacteremia, although MRSA infection was not found to be significantly associated with higher mortality in overall patient population.
    The Journal of infection 10/2010; 61(4):299-306. · 4.13 Impact Factor
  • Article: The prevalence of plasmid-mediated quinolone resistance determinants among clinical isolates of ESBL or AmpC-producing Escherichia coli from Chinese pediatric patients.
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    ABSTRACT: Three kinds of PMQR determinants (qnr genes, aac(6')-Ib-cr, and qepA) have been discovered and shown to be widely distributed among clinical isolates. To characterize the prevalence of PMQR determinants in ESBL or AmpC-producing E. coli clinical isolates in Chinese children, a total of 292 ESBL or AmpC-producing E. coli clinical isolates collected from five children's hospitals in China from 2005 to 2006 were screened for PMQR determinants by PCR. Twenty (6.8%) of the 292 isolates were positive for PMQR determinants. A total of 12 (4.1%) isolates were positive for qnr genes, comprising three positive for qnrA (1.0%), three for qnrB (1.0%), and six for qnrS (2.1%). Twenty-four (8.2%) isolates were positive for aac(6')-Ib, of which 10 (3.4% of 292) had the -cr variant. There was no qepA gene detected in the isolates. Conjugation revealed that qnr, aac(6')-Ib-cr, and ESBL-encoding genes were transferred together.
    Microbiology and Immunology 03/2010; 54(3):123-8. · 1.30 Impact Factor
  • Article: [Antioxidative role of peroxiredoxin 6 in acute lung injury].
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    ABSTRACT: To confirm the antioxidant protective effect of peroxiredoxin 6 (Prdx6) in acute lung injury in mice. Lung injury or lung alveolar type II epithelial cell (AEC II) injury models were induced in mice by 100% O2 exposure or H2O2 treatments. Mice and AEC II cell survival rate or BALF analysis were applied for evaluating the degree of acute lung injury. Western Blot assay was used to determine Prdx6 or Gpx1 protein expression in lung. Annexin V staining method was applied to detect cell apoptosis on cultured AEC II cell, and thiobarbituric acid reactive substance (TBARS) measurement and diphenyl-1-pyrenyl phospholine (DPPP) assays were separately used to measure the level of lipid peroxidation in mice lung and AEC II cell membrane. Under 100% O2 exposure, Prdx6-/- mice presented 24 h shorter survival time compared to wild type (WT) mice, on the contrary, Prdx6 gene over-expressed (Tg Prdx6) mice showed enhanced mice survival; meanwhile, the degree of AEC II cell injury had H2O2-dose dependent pattern with interactive relationship of Prdx6 protection. Under 100% O2 exposure for 72 h, it caused 7-fold decreased Gpx1 expression in Prdx6-/- mouse lung with no remarkable decrease of Prdx6 expression in Gpx1-/- mice. The percentage of apoptotic cells was significantly increased in AEC II cells from Prdx6-/- mice, and the percentage of AEC II apoptotic cells from Tg Prdx6 kept consistently around 10% under H2O treatments; also, the lipid peroxidation level of AEC II cell membrane was the highest in the group of Prdx6-/- mice, which was about 2 or 4-fold increased compared to the groups of WT or Tg Prdx6, separately; meanwhile, the lipid peroxidation level in Prdx6-/- mice, was also the highest compared to the other groups. Prdx6 plays a critical role in defending acute oxidative lung injury and its function of defending cell apoptosis and cell membrane lipid peroxidation suggests its unique cell-based protective effect.
    Zhonghua er ke za zhi. Chinese journal of pediatrics 11/2008; 46(10):739-44.
  • Article: [Impact of endogenous inflammation caused by adenovirus as a vector in gene therapy: experiment with mice models of acute lung injury].
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    ABSTRACT: To evaluate the impact of endogenous inflammation caused by adenovirus as a vector of gene therapy on mouse model of acute lung injury (ALI). Black C57/B6 mice randomly divided into 4 research groups: (1) adenovirus encoded-lacZ gene treatment group (AdLacZ): n=43; (2) three control groups: (1) before 100% O2 inhalation (Con): n=26; (2) 100% O2 inhalation with TBS + PBS treatment (PBS): n=36; (3) 100% O2, inhalation without treatment (no treatment): n=33. AdLacZ reagent through intranasal administration to infect mice lungs at 48h before 100% O2 inhalation to induce ALI mouse model, which companies by mice survival rates recorded. beta-gal protein activity in lung was detected to show the level of LacZ DNA transgenic protein activity;meanwhile, the indices of lung wet/dry ratio and bronchial alveolar lavage liquid (BALF) analysis with protein concentration and cell classification were detected. The method of adenovirus-mediated gene therapy with intranasal administration resulted in LacZ DNA transgenic protein activity to keep effective highly expression in lung, and the expression level maintained 2-fold increasing even after 72 h of O2 inhalation compared to that before O2 inhalation (3.688 U/mg vs. 1.589 U/mg); AdLacZ mice had more subjective to O2 inhalation compared to other groups, the 50% mice survival time of this group was shorter compared to that of the PBS group [(86 +/- 3) h vs. (94 +/- 7) h]; also in AdLacZ group, the level of nucleated cell counting in BALF was statistically higher compared to other groups at 48 h of O2 inhalation, which following with 50%-level decreased within anther 24 h O2 inhalation; on the contrary, the level of lung wet/dry ratio and protein concentration in BALF didn't show remarkably decreasing. The endogenous inflammation caused by adenovirus as a vector in ALI gene therapy is temporary and rapidly weaken after getting a peak, however, enough attention still should be paid attention when evaluating the effect of gene therapy.
    Zhonghua yi xue za zhi 08/2008; 88(26):1841-5.
  • Article: Drug utilisation 90% (DU90%) profiles of antibiotics in five Chinese children's hospitals (2002-2006).
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    ABSTRACT: This study surveyed the pattern of inpatient antibiotic use in five Chinese children's hospitals between 2002 and 2006, focusing on the antibiotics accounting for 90% of the volume utilised as well as the level of adherence to guidelines. The Anatomical Therapeutical Chemical Classification/Defined Daily Doses (ATC/DDD) and the drug utilisation 90% (DU90%) methodologies were used. In October 2004, national antibiotic guidelines were issued that divided antibiotics into non-restricted, restricted and special use grades. In five children's hospitals, a total of 56 different systemic antibiotics were used during the study period. Antibiotics that could be injected accounted for 59.0-99.8%. beta-Lactam antibacterials (ATC codes J01C and J01D) were the most used subgroups. The numbers of antimicrobial agents and non-restricted antibiotics within the DU90% segment were 11-20 and 5-9, respectively. The proportion of non-restricted antibiotic consumption was ca. 40% in 2006 in four hospitals, which varied among hospitals during the period 2002-2005. There was considerable variation both in the pattern and amount of antibiotics used in the five hospitals, with amoxicillin/clavulanic acid, cefuroxime and cefazolin being the most commonly used substances. We also observed a decrease in the ranks of some restricted and special use antibiotics after the guidelines were issued in one hospital. The DU90% profiles were proven to be useful in studying the pattern of antibiotic use in hospitals. Finally, the study observed the effectiveness of guidelines for antibiotic use in some hospitals, although injectable antibiotics were widely used in children's hospitals in China.
    International Journal of Antimicrobial Agents 08/2008; 32(3):250-5. · 4.13 Impact Factor
  • Article: Occurrence of qnr-positive clinical isolates in Klebsiella pneumoniae producing ESBL or AmpC-type beta-lactamase from five pediatric hospitals in China.
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    ABSTRACT: The plasmid-mediated quinolone resistance qnr genes in clinical isolates in adults have been described in different countries; however, the frequency of their occurrence has not been detected in pediatric patients. A total of 410 clinical isolates of Klebsiella pneumoniae, identified as producers of an extended-spectrum beta-lactamase (ESBL), or AmpC beta-lactamase, were collected from five children's hospitals in China during 2005-2006. The isolates were screened for the presence of the qnrA, qnrB, and qnrS genes, and then the harboring qnr gene isolates were detected for a bla gene coding for the TEM, SHV, CTX-M, and plasmid-mediated ampC gene by a PCR experiment. Ninety-two isolates (22.7%) were positive for the qnr gene, including 10 of qnrA (2.4%), 25 of qnrB (6.1%), and 62 of qnrS (15.1%). Eighty-one of the 92 (88.0%) qnr-positive isolates carried at least one bla gene for TEM, SHV, CTX-M, or DHA-1. The ciprofloxacin resistance increased 16-256-fold and oflaxacin resistance increased 2-32-fold in transconjugants, respectively. These results indicated that the plasmid-mediated qnr quinolone resistance gene was qnrS, followed by qnrB and qnrA. Most of the isolates also carried a bla gene coding ESBL or ampC gene coding DHA-1 among Klebsiella pneumoniae isolated from Chinese pediatric patients.
    FEMS Microbiology Letters 07/2008; 283(1):112-6. · 2.04 Impact Factor
  • Article: [Prevalence of extended-spectrum beta-lactamase producing Escherichia coli in pediatric patients in China].
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    ABSTRACT: To study the drug resistance profiles of extended spectrum beta lactamase (ESBL) producing Escherichia coli (E. coli) and provide guidance for pediatric clinical prescription. 5127 strains of ESBL producing E. coli were isolated from 5 children's hospitals in Beijing, Shanghai, Chongqing, and Guangzhou. The minimum inhibitory concentration (MIC) values of 349 strains to 9 antibiotics most in use in pediatrics were measured with agar dilution method. The prevalent rate of ESBL producing of E. coli was 46.7%. The resistant rates to ampicillin/clavulanic acid, cefotaxime, ceftazidime, and cefepime were 23.1%, 67.2%, 24.5%, and 48.4% respectively, and the intermediate rates were 38.5%, 26.4%, 5.7%, and 19.1% respectively. The resistant rate to amikacin was 5.4%. All the strains were susceptible to imipenem. The MIC90 values of ampicillin, cefotaxime, cefepime, ciprofloxacin, and gentamicin were 256 mg/L or higher. There were differences in the resistance profile to ampicillin/clavulanic acid, cefepime, ciprofloxacin, and gentamicin among different regions. ESBL is extensively prevalent among the E. coli strains isolated from the pediatric clinic that are resistant to most antimicrobial agents except imipenem and amikacin. Regional difference exists in drug resistance to some agents exist.
    Zhonghua yi xue za zhi 06/2008; 88(20):1372-5.
  • Article: Antibiotic use in five children's hospitals during 2002-2006: the impact of antibiotic guidelines issued by the Chinese Ministry of Health.
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    ABSTRACT: To investigate the pattern of antibiotic use in five Chinese children's hospitals from 2002 to 2006. To see if the Guidelines to encourage rational use of antibiotics issued by the Ministry of Health in October 2004 have any impact on the use. The Anatomical Therapeutic Chemical Classification/Defined Daily Doses (ATC/DDD) methodology was used. Aggregate data on antibiotic use (ATC code-J01) were expressed in numbers of DDD/100 bed-days for inpatients. Total 56 different substances of systemic antibiotics were used. The overall consumption of antibiotic drugs was 68.2, 58.4, 65.8, 65.6 and 49.9 DDD/100 bed-days for the years 2002-2006, respectively. The top antibiotics used were third-generation cephalosporins. There was considerable variation in both type and amount of antibiotics used in the five hospitals. In 2002, some hospitals had twice the antibiotic use compared to others. While the overall antibiotic use in 2005 was largely unchanged compared with previous years, by 2006 antibiotic use had decreased by 22.6% and the variation in use between hospitals was also reduced. The ATC/DDD methodology proved useful for studying overall antibiotic usage in children's hospitals. The decline in antibiotic usage found in 2006 (and the reduced variation between hospitals) may be attributed to the impact of the Ministry of Health guidelines which took some time to be promulgated to individual staff members. Further research will focus on compliance of antibiotic use in these five hospitals with particular guideline recommendations for specific clinical problems such as bacterial resistance and surgical antibiotic prophylaxis.
    Pharmacoepidemiology and Drug Safety 04/2008; 17(3):306-11. · 2.53 Impact Factor
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    Article: Presence of qnr gene in Escherichia coli and Klebsiella pneumoniae resistant to ciprofloxacin isolated from pediatric patients in China.
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    ABSTRACT: Quinolone resistance in Enterobacteriaceae results mainly from mutations in type II DNA topoisomerase genes and/or changes in the expression of outer membrane and efflux pumps. Several recent studies have indicated that plasmid-mediated resistance mechanisms also play a significant role in fluoroquinolone resistance, and its prevalence is increasing worldwide. In China, the presence of the qnr gene in the clinical isolates of Enterobacteriaceae has been reported, but this transmissible quinolone resistance gene has not been detected in strains isolated singly from pediatric patients. Because quinolones associated with a variety of adverse side effects on children, they are not authorized for pediatric use. This study therefore aimed to investigate the presence of the qnr gene in clinical isolates of E. coli and K. pneumoniae from pediatric patients in China. A total 213 of non-repetitive clinical isolates resistant to ciprofloxacin from E. coli and K. pneumoniae were collected from hospitalized patients at five children's hospital in Beijing, Shanghai, Guangzhou, and Chongqing. The isolates were screened for the plasmid-mediated quinolone resistance genes of qnrA, qnrB, and qnrS by PCR. Transferability was examined by conjugation with the sodium azide-resistant E. coli J53. All qnr-positive were analyzed for clonality by enterobacterial repetitive intergenic consensus (ERIC)-PCR. The study found that 19 ciprofloxacin-resistant clinical isolates of E. coli and K. pneumoniae were positive for the qnr gene, and most of the qnr positive strains were ESBL producers. Conjugation experiments showed that quinolone resitance could be transferred to recipients. Apart from this, different DNA banding patterns were obtained by ERIC-PCR from positive strains, which means that most of them were not clonally related. This report on transferable fluoroquinolone resistance due to the qnr gene among E. coli and K. pneumoniae strains indicated that plasmid-mediated quinolone resistance has emerged in pediatric patients in China.
    BMC Infectious Diseases 02/2008; 8:68. · 3.12 Impact Factor
  • Article: Five-year surveillance of antimicrobial use in Chinese Pediatric Intensive Care Units.
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    ABSTRACT: In order to demonstrate antibiotic usage in Chinese Pediatric Intensive Care Units (PICUs), and provide some data to further study on relation of antimicrobial use and resistance. We reviewed the use of antibiotics in Chinese PICUs from 2002 to 2006. All data, including general data and antibiotic use data, were obtained from five PICUs of pediatric teaching hospitals in China. The results of antibiotic use were expressed as defined daily doses (DDDs) per 100 patient-days by WHO in this study. All 12 743 patients were included from the five PICUs in this study. Length of stay in PICUs was essentially unchanged, but the percentage of antimicrobial costs vs. drug costs dramatically decreased in this study period (p < 0.01). The percentage of empiric treatment decreased by year (from 82.2% to 70.2%). while the percentage of therapeutic treatment increased by year (from 11.2% to 24.2%) from 2002 to 2006. Total antibiotic usage decreased from 72.1 DDDs per 100 patient-days to 35.5 DDDs per 100 patient-days from 2002 to 2006 (p < 0.05). The significant increase was found in the DDDs per 100 patient-days of second generation cephalosporins in this study (p < 0.05). While usages of the some antibiotics decreased, for example penicillins, third-generation cephalosporins, and macrolides in this study period. The data of antimicrobial use were obtained from five PICUs of biggest pediatric teaching hospital in this 5-year period, which could serve as a basis of antibiotic treatment and a benchmark in future study of antibiotic use.
    Journal of Tropical Pediatrics 02/2008; 54(4):238-42. · 1.39 Impact Factor
  • Article: [Clinical evaluation for sublingual immunotherapy of allergic asthma and atopic rhinitis with Dermatophagoides Farinae Drops].
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    ABSTRACT: To evaluate the safety and efficacy of sublingual immunotherapy with 'Dermatophagoides Farinae Drops' in D. farinae allergic asthma and/or rhinitis patients. A 25-week double-blind, placebo-controlled, multi-centered trail was conducted in 278 children (aged 4 - 18 yr) with mite-induced asthma and/or rhinitis. Patients were randomly assigned to receive sublingual immunotherapy (SLIT) with 'Dermatophagoides Farinae Drops' (n = 139) or placebo (n = 139) for 25 weeks and the dosage and administration strictly followed the manufacturer's instructions. At the beginning of the 2nd, 3rd, 4th, 6th, 10th, 14th, 18th, 22nd week of the treatment, the patients were asked to accept follow-up visit, during the clinical trial all patients and parents were asked to keep a daily record of their asthma symptom scores, rescue medicine use, rhinitis symptom scores, morning and evening peak expiratory flow. Asthma symptom scores, reduction in use of rescue medicine, rhinitis symptom scores, lung function tests, skin sensitivity to mite, mite-specific immunoglobulin (Ig) E and IgG4, and quality of life and adverse effect were assessed during the study. (1) Of the 278 children, 27 dropped out before the study completion. (2) After 25 weeks of treatment, the median variability of PEFR was -1.38 for SLIT group and -0.90 for the placebo (P < 0.05). (3) Besides, the mean variability of medicine score of asthma was -0.08 for SLIT group and 0.52 for the plcebo (P < 0.05). (4) The median variability of rhinitis symptom score was -1.96 for SLIT group and -1.03 for the placebo (P < 0.01). (5) The rescue medicine usage of SLIT reduced but did not show significant differences between SLIT and placebo. (6) After 25 weeks treatment, the increase of D. farinae specific IgE antibody of two groups were similar, while specific IgG4 increased significantly in SLIT compared to the patients in control one (P < 0.01); (7) No severe adverse events happened in the trial and the most-likely adverse events were mild asthma and local rash. Dermatophagoides Farinae Drops is safe and effective in treating allergic asthma and atopic rhinitis.
    Zhonghua er ke za zhi. Chinese journal of pediatrics 11/2007; 45(10):736-41.
  • Article: [Pay attention to community acquired pneumonia in children].
    Zhonghua er ke za zhi. Chinese journal of pediatrics 03/2007; 45(2):81-2.
  • Article: [Serotype distribution and resistance to beta-lactams of Streptococcus pneumoniae isolated from children in Beijing, Shanghai and Guangzhou, 2000 - 2002].
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    ABSTRACT: The present study was designed to investigate the situation of serotype distribution and beta-lactam antibiotics resistance of Streptococcus pneumoniae (S. pneumoniae) isolated from Chinese children, and to further understand the significance of vaccine for preventing infection caused by the bactria and controlling the resistance to antibiotics. Nasopharageal swab specimens were collected from randomly selected less than 5-year-old out-patients with upper respiratory infection in Beijing, Shanghai and Guangzhou, 2000 - 2002. Capsular typing was performed by the Quellung reaction tested using a simplified chessboard system for typing of S. pneumoniae. The coverage rate of the 7-valent pneumococcal conjugate vaccine (4, 6B, 9V, 14, 18C, 19F and 23F) was calculated. Antibiotic susceptibility was determined by E-test MIC method for beta-lactam antibiotics (penicillin, amoxicillin/clavulanic acid, cefaclor, cefuroxime and ceftriaxone). Totally 625 pneumococcal strains were typed. Serogroup 19, including 121 strains, was the most frequent serogroup observed (19.4%). Other frequently observed serotypes/serogroups in decreasing order of frequency were serotype/serogroups 23 (15.4%), 6 (13.3%), 14 (6.6%) and 15 (4.3%). Of all these isolates, about 57.6% (360/625) were in the 7-valent conjugate vaccine. Only 1, 6 and 12 strains were serotypes/serogroups 4, 9 and 18, respectively. The coverage rate for the 7-valent vaccine of penicillin nonsusceptible S. pneumoniae (PNSP) was higher than penicillin susceptible S. pneumoniae (PSSP) (73.2% and 46.1%). Serogroups 19 and 23, without other serotypes/serogroups, were significantly associated with PNSP (serogroup 19 accounted for 29.1% of PNSP and 12.2% of PSSP; serogroup 23 accounted for 23.8% of PNSP to 9.2% of PSSP). Overall, 140 strains (22.4%) could not be typed by using the chessboard system, and 117 strains (18.7%) were identified as other 28 kinds of serotype/serogroup. The strains showed different resistance change for beta-lactam antibiotics according to different serotype/serogroup during the three years. Serotype/Serogroup 19, 23, 6, 14 and 15 were the common types among the pneumococcal strains isolated from Chinese children. Serogroups 19 and 23 were significantly associated with PNSP. The 7-valent pneumococcal conjugate vaccine could cover most of the islotes.
    Zhonghua er ke za zhi. Chinese journal of pediatrics 01/2007; 44(12):928-32.
  • Article: [Antibiotic resistance of pathogenic bacteria related to respiratory infections in children from Shanghai].
    Zhongguo dang dai er ke za zhi = Chinese journal of contemporary pediatrics 09/2006; 8(4):338-40.
  • Article: [Characterization of macrolide-resistance mediated by transposable elements Tn1545 and Tn917 in clinical Isolates of Streptococcus pneumoniae].
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    ABSTRACT: To investigate the characterization of ermB gene expression and dissemination in macrolide-resistant Streptococcus pneumoniae (Sp) in Shanghai. Eighty-six erythromycin-resistant isolates of Sp were isolated from 3 hospitals in Shanghai. E-test or K-B disk diffusion test were used to determine the susceptibility to 12 antibiotics according to the National Committee for Clinical Laboratory Standards. Macrolide resistant genes ermB and mefE, and transposable elements Tn1545 and Tn917 were amplified by PCR. The isolates were divided into Tn1545 and Tn917 groups according to the transposable elements thereof. Double disc test with erythromycin and clindamycin discs divided the isolates into 2 macrolide resistant phenotypes: cMLS(B) (inducible) phenotype and M phenotype (resistant to erythromycin and sensitive to clindamycin). BOX-PCR was used to analyze the homology of the S. pneumoniae. (1) Of the 86 erythromycin-resistant isolates, the positive rates of ermB, mefE, Tn1545, and Tn917 were 94%, 46%, 87% and 7% respectively. Tn1545 and Tn917 were not detected in 5 ermB-mdfE + strains. (2) Most strains in the Tn1545 and Tn917 groups were highly resistant to erythromycin with a MIC50 of 256 microg/ml. The Tn917 group had a lower MIC to beta-lactam antibiotics and lower resistance to tetracycline, levofloxacin, and compound sulfonamide in comparison with the Tn1545 group. (3) The most common macrolide resistance phenotype of the Tn1545 group was cMLS(B) phenotype. Three strains in the Tn917 group had a 194 bp deletion in the promoter region of ermB and an insertion of TAAA motif in the N end of leader peptide, resulting in the change of the ermB gene from inducible to constitutive expression. (4) BOX-PCR showed that Tn1545 and Tn917 might spread horizontally. In Shanghai ermB-mediated cMLS(B) is the most prevalent phenotype in macrolide-resistant Streptococcus pneumoniae isolates. Primarily, the ermB gene was carried and spread horizontally by Tn1545.
    Zhonghua yi xue za zhi 04/2006; 86(9):605-8.
  • Article: [Carrier rate of Streptococcus pneumoniae and susceptibility thereof to antimicrobial drugs among children in China: a surveillance study in Beijing, Shanghai, and Guangzhou 2000-2002].
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    ABSTRACT: To investigate the carrier rate of Streptococcus pneumoniae and the susceptibility of S. pneumoniae to 10 different antimicrobial drugs among children in China. Nasopharageal swab specimens were collected from randomly selected 3578 out-patients with upper respiratory infection aged 1 month to 5 years in Beijing, Shanghai, and Guangzhou 2000-2002 so as to isolate S. pneumoniae. The susceptibility of these strains to erythromycin and beta-lactam antibiotics (penicillin, amoxicillin/clavulanic acid, cefaclor, cefuroxime and ceftriaxone) was determinated by E-test MIC method, and the susceptibility to chloramphenicol, tetracycline, sulfamethoxazole/trimethoprim and ciprofloxacin was determinated by disk diffusion method. A total of 892 strains of S. pneumoniae were isolate from the 3578 children with a carrier rate of 24.9% (9.0%-36.0%). 634 isolates of S. pneumoniae were tested to examine their susceptibility to chloramphenicol, 199 to ciprofloxacin, and 887 to the other 8 antimicrobial drugs. The insusceptibility rate of S. pneumoniae to penicillin was 39.9%, and the resistance rate was 6.4%. The resistance rate to cefaclor was 20.4%. The insusceptibility rate to cefuroxime was 19.0%. The susceptibility rate to amoxicillin/clavulanic acid was 98.5% and that to ceftriaxone was 97.2%. More than 80% of the isolates were resistant to erythromycin, tetracycline, and sulphamethoxazole/trimethoprim. Chloramphenicol resistance was less common (32.3%) than the resistance to other non-beta-lactam antibiotics, except for ciprofloxacin to which the resistance rate was 2.0%. The national insusceptibility rates for beta-lactam antibiotics did not vary significantly during the three years with the widest varying range of 5.1% for penicillin (38.1%-43.2%). Each of the three cities had their different varying patterns of antimicrobial susceptibility, especially for beta-lactam antibiotics. Multi-drug resistance was common (88.7%). Strains of S. pneumoniae insusceptible to penicillin were significantly more common than those susceptible to penicillin (99.1% vs. 78.8%, chi(2) = 50.36, P < 0.001), and strains of S. pneumoniae insusceptible to erythromycin were significantly more common than those susceptible to erythromycin too (95.8% vs. 17.1%, chi(2) = 360.26, P < 0.001). Antimicrobial resistant S. pneumoniae has already become a serious problem in China. Ongoing surveillance study on the antimicrobial resistance of S. pneumoniae is necessary for appropriate antimicrobial use in clinical work and modification of medical strategies for people's health.
    Zhonghua yi xue za zhi 07/2005; 85(28):1957-61.
  • Article: [In vitro antibacterial activity of cefdinir against isolates of respiratory tract pathogens in children].
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    ABSTRACT: To study the in vitro antibacterial activity of cefdinir against clinical isolates of respiratory tract pathogens in Children. MIC values of cefdinir against 380 strains were determined with E-test method and compared with those of cefaclor. All penicillin-susceptible Streptococcus pneumoniae (PSSP) strains were also susceptible to cefdinir and cefaclor. Both cefdinir and cefaclor were not active against penicillin-resistant SP (PRSP). Against penicillin-intermediate SP (PISP) the susceptibility rates of cefdinir and cefaclor were 70.1% and 57.4%, respectively. The activity of cefdinir and cefaclor against beta-lactamases negative Hemophilus influenzae (HI) was excellent, but the susceptibility rates of cefdinir and cefaclor against beta-lactamases positive HI were 85.0% and 70.0%, respectively with MIC(90) of 1.5 mg/L vs. 256.0 mg/L. Cefdinir presented higher activities and lower MIC values than cefaclor against Moraxella catarrhalis (MC), Group A streptococcus (GAS), methicillin susceptible staphylococcus aureus (MSSA), and extended spectrum beta-lactamases (ESBLs) negative Escherichia coli (E. coli) or Klebsiella pneumoniae (K. pn). Both cefdinir and cefaclor were not susceptible to ESBLs positive E. coli and K. pn. Cefdinir exhibits excellent activity against PSSP, PISP, HI, as well as MC, GAS, MSSA and ESBLs negative E. coli or K. pn.
    Zhonghua er ke za zhi. Chinese journal of pediatrics 10/2004; 42(9):697-700.