Effects of amino acid substitutions of penicillin-binding proteins 2B, 1A, 2X on minimal inhibitory concentration of beta-lactams against Streptococcus pneumoniae / 中华儿科杂志

<p><b>OBJECTIVE</b>To observe the effect of amino acid substitution in conserved sequence of penicillin-binding protein (PBP) 1A, 2B, 2X on antimicrobial activity of beta-lactams against Streptococcus pneumoniae (SP).</p><p><b>METHOD</b>Minimal inhibitory concentration (MIC) of 6 beta-lactams was determined by the E-test in 59 SP strains. The penicillin-binding protein genes pbp1a, 2b, 2x in every SP strain were amplified by nested-polymerase chain reaction (nPCR), then the PCR products were sequenced using automatic genetic analyzer directly. To analyze the amino acid substitutions, the DNA sequences were converted to protein sequences and aligned by Clustalx software. According to amino acid substitution in conserved sequence of PBP2B, 3 phenotypes were observed, including: PBP2B phenotype I (no amino acid substitution); PBP2B phenotype II (Glutamine 432-->Leucine and/or Threonine 445/451-->Alanine/Serine, Glutamic 481-->Glycine, 1 strain had proline insertion between residues 431/432); PBP2B phenotype III (Alanine 624-->Glycine with the addition of phenotype II). According to amino acid substitution in conserved sequence of PBP1A, 3 phenotypes were observed, including: PBP1A phenotype I (no amino acid substitution); PBP1A phenotype II (Threonine 574-->Asparagine, Serine 575-->Threonine, Glutamine 576-->Glycine, Phenylalanine 577-->Tyrosine, 574TSQF-->NTGY); PBP1A III (Threonine 371-->Alanine/Serine, Proline 432-->Threonine with the addition of 574TSQF-->NTGY). According to amino acid substitution in conserved sequence of PBP2X, 4 phenotypes were observed, including: PBP2X phenotype I (no amino acid substitution); PBP2X phenotype II (Histidine 394-->Leucine or Threonine 338-->Alanine); PBP2X phenotype III (Threonine 338-->Alanine, Isoleucine 371-->Threonine, Arginine 384-->Glycine and Leucine 546-->Valine); PBP2X phenotype IV (Methionine 339-->Phenylalanine, Methionine 400-->Threonine with the addition of PBP2X phenotype III).</p><p><b>RESULT</b>Among 59 SP strains antibacterial activities distribution (sensitive strains, intermediate strains and resistant strains) of 6 beta-lactams were penicillin (12, 29, 18); amoxicillin(49, 9, 1); cefuroxime (16, 16, 27); ceftriaxone (47, 1, 11); cefotaxime (47, 3, 9); imipenem (49, 10, 0). beta-lactam antibiotics insensitive strains (intermediate + resistant strain) in PBP2B phenotype III, PBP1A phenotype III, PBP2X phenotype III and IV were significantly increased, the MIC(50) of these strains were significantly higher than that of the others.</p><p><b>CONCLUSION</b>The amino acid substitutions in or vicinal conserved sequence of PBP of SP increase MIC for beta-lactam antibiotics.</p>

Clinical Significance of Single Photon Emission Computed Tomography Regional Cerebral Blood Flow Imaging on Dyskinesia in Children with Cerebral Palsy / 实用儿科临床杂志

0.05).Compared with abnormality of rCBF in spastic left hemiplegia,there was significant difference between right and left lobes of cerebrum(P

Effects of Family Allergic History and Dermatophagoides Farina on Expression of Th1/Th2 Cytokine of Cord Blood and Allergic Disorders in Infancy / 实用儿科临床杂志

Objective To investigate the effects of family allergic history and dermatophagoides farina on the expressions of Th1/Th2 cytokine of cord blood and allergic disorders in infancy.Methods Ten mil cord blood were obtained from 34 neonates which 17 cases had family allergic history and 17 cases didn′t have.Cord blood mononuclear cells(CBMC) were isolated by gradient centrifugation with Ficoll and were cultured with phytohemagglutinin(PHA) or dermatophagoides farina for 48 hours in vitro.The expressions of interleukin(IL-4) and interferon(IFN-?) of the culture supernatant were detected by enzyme-linked immunosorbent assay(ELISA).Two groups were visited with telephone or clinical service every 1 or 2 months in 1 year follow-up survey.Results In no stimulation,the expressions of IL-4 of family allergic history and no family allergic history were(11.35?1.80) ng/L and(11.0?1.50) ng/L,respectively,there was no significant difference.The expressions of IFN-? were(9.55?1.47) ng/L and(10.19?1.37) ng/L,respectively,there was no significant difference also.In PHA stimulation,the expressions of IL-4 were(43.45?4.57) ng/L and(37.58?3.41) ng/L,respectively,there was significant difference.The expressions of IFN-? were(72.61?25.40) ng/L and(65.84?29.96) ng/L,respectively,there was no significant diffe-rence.In low density dermatophagoides farina stimulation,the expressions of IL-4 were(40.54?3.64) ng/L and(37.17?2.60) ng/L,respectively,which had significant difference.The expressions of IFN-? were(35.30?2.73) ng/L and(40.55?1.85) ng/L,respectively,which had significant difference.In high density dermatophagoides farina stimulation,the expressions of IL-4 were(43.50?3.19) ng/L and(39.55?4.13) ng/L,respectively,which had significant difference.The expressions of IFN-? were(39.40 ?5.21) ng/L and(40.94?2.96) ng/L respectively,which had no significant difference.Allergic diseases were happened in 7 cases of 13 cases with family allergic history and in 2 cases of 15 cases without family allergic history in 1 year follow-up except lost follow-up cases.There were significant difference in 2 groups.Conclusions Th2 cells of cord blood are relative dominant in neonates having family allergic history.Th2 cells relative dominant are more obvious in dermatophagoides farina stimulation.The neonates having family allergic history have a tendency to get allergic diseases in childhood.

Study on Non-Bacteria Etiology of Pneumonia in Shanghai Southwest Area / 实用儿科临床杂志

Objective To explore the non-bacteria etiology of pneumonia in children under 12 years old in southwest Shanghai,and investigate clinical characteristic of pneumonia caused by different pathogens.Methods The serum of 187 children with pneumonia from July 2002 to December 2004 in hospital were investigated for respiratory syncytial virus(RSV),adenovirus 3 influenza viruses(IFV) A and B,parainfluenza viruses(PIV)type 1,2,3,4 and coxsackievirus A 1.7,echovirus 7 by employing the indirect immunofluorescence assay(IFA)for the identification of nearly 8 different viruses,and 3 different enteroviruses.Based on the principle that sensitized particles were agglutinated by the pressence of antibodies to mycoplasma pneumonia in human serum.Results Examination for 8 kinds of conventional respiratory virus infected,a total of 90 positive results in 187 cases(48.13%),Firstly was RSV(19.79%),(secondly) was IFV B(16.58%).Out of these 1084 children,154 cases(14.21%)showed positive in anti-mycoplasma pneumonia.Conclusions RSV is still the leading cause of pneumonia in children during winter and spring in southwest in Shanghai.Mycoplasma pneumonia is having been the major pathogens of the school-aged children with pneumonia.

Assay and Analysis on Three Virus Pathogen of Pneumonia in Children / 实用儿科临床杂志

Objective To explore the child pneumonia in infection circumstances of Coxsackie B virus(CVB), Cytomegalovirus(CMV),Epstein-Barr virus (EBV).Methods Indirect ELISA were used to detect the specific IgM antibody of CVB, CMV, EBV. Results The total positive rate,which suffer from the three kinds of viruses in 140 children wich pneumonias was 38.6%.The positive rates of the CVB- IgM, CMV- IgM, EBV- IgM were 24.3%,8.6%,6.5%.Conclusions CVB has the higher infection rate in the pneumonia, is one of the main causes in the infection of child pneumonia.CMV,EBV also has the certain infection rate, although the infection rate is not high, they can cause damage of many organs and systems .They should be watched out for and valued.

Drug Sensitive Analysis of 207 Strains of Staphylococcus Aureus in Children / 实用儿科临床杂志

Objective To analyze the changes of the frequency of staphylococcus aureus (SAU) and methicillin resistant staphylococcus aureus (MRSA) isolated from hospitalized children from 2003 to 2006,and investigate the 21 antimicrobial susceptibility against SAU strains for providing reference for clinical rational use of drug.Methods The SAU strains were isolated from 207 children who were hospitalized in department of pediatrics of the sixth people′s hospital affiliated to Shanghai jiaotong university from Jan.2003 to Dec.2006 during the first 48 h of hospital stay.Strains were isolated from cotton-tipped swab of throat culture 75 strains,sputum culture 57 strains,secretion of bellybutton culture 25 strains,liquor puris culture 23 strains,hemoculture 20 strains,tube thoracostomy culture 3 strains,middle piece urnary culture 3 strains,cerebrospinal fluid culture 1 strain.The strains were identified by latex agglutination test,the in vitro activities of the 21 antimicrobial agents against 207 SAU isolates was tested by disc diffusion test (K-B method) according to the guidelines of the clinical and laboratory standards institute.MRSA was screened by oxacillin disc diffusion test.The data were analyzed by WHONET 5 software,Cochran-Mantel-Haenszel was used to analyze the tendency of SAU isolating rate and MRSA detectable rate.Results Of these SAU,30 strains(14.5 %) isolates were MRSA and 177 strains(85.5 %) were methicillin sensitive staphylococcus aureus.The sensitive rates of SAU to Penicilin,Oxacillin,Cefuroxime Sodium,Cefotaxime,Ceftriaxone,Erythromycin,Clindamycin,Trimethoprim/Sulfamethoxazole,Ciprofloxacin,Fosfomycin and Rifampin were 4.8%,85.5%,84.9%,90.0%,88.3%,37.5%,46.3%,92.7%,74.2%,97.2%,94.0%,respectively.All the strains were sensitive to peptide antibiotic(for instance,vacomycin and teicoplanin) and Levofloxacin.The SAU isolated rate and MRSA detectable rate were 9.6%,19.8%,25.0%,39.5% and 5.0%,5.9%,12.7%,24.7% in 2003-2006,respectively.Conclusions SAU has strong resis-tance to Penicilin and Erythromycin,but relative sensitive to Oxacillin and Cephalosporin.The SAU isolatating rate and MRSA resistant rate is increased in our area,pediatrics should to strengthen the monitoring of SAU is important in pediatrics.