Escherichia coli ; genetics ; pathogenicity ; Humans ; Infant, Newborn ; Virulence ; genetics

Objective To evaluate the efficacy and safety of a new drug,human urinary kallidinogenase,against acute brain infarction.Method A 15-center,randomized,double-blinded and 3:1 placebo-controlled study was carried out.Acute brain infarction within 48 hours of onset in the territory of the middle cerebral artery were indicated as subjects;kallidinogenase or placebo which was dissolved in 50 ml saline,was slowly injected intraveousely within 30 minutes daily for 3 weeks.The European Stroke Scale and Barthel Index were used to evaluate the neurological deficit and the activities of daily living(ADL),followed by a follow-up at the end of the third month.Results 446 patients were enrolled,who completed ITT analysis,including 330 in kallidinogenase group and 116 in placebo group,meanwhile 421 proceeded with PP analysis(311 and 110 respectively).There were no significant differences of the baseline data between the 2 groups.At the end of treatment,the ESS scores increased by 55.1%?33.0% and 44.7%?32.8% respectively in kallidinogenase group(KG)and placebo group(PG,P=0.0022),the difference being significant.PP analysis had similar results.As for ADL,follow-up 90 days after the treatment showed 374 cases followed,280 in KG and 94 in PG;1 died in PG,while none in KG.In KG,the cases whose BI≥50 were significantly more than those in PG(P=0.0228).Adverse events possibly or definitely attributable to the drug were observed in 27 cases(7.74%),mostly were mild,such as palpitation,flush,dizziness, nausea etc,without special management needed.Only 2 died which was confirmed not correlated to kallidinogenase,and another 2 cases of sudden blood pressure drop were observed.The blood pressure drop, quickly restoring soon after the withdrawal of kallidinogenase and use of hemopiesic drugs,was considered to be caused by the combination use of anti-hypertensive drug ACEI and quick infusion speed.Conclusion Kallidinogenase is efficacious for acute brain infarction in improving the neurological deficits,which is safe in clinical use.

Biofilms are microbial communities which are enclosed within a matrix of exopolysaccharides produced by the bacteria,fungi and protozoa growing intimately on a living or inert surfaces.Further researches on bcterial biofilms formation and molecular machines,pathogenic mechanisms (especially drug resistance),detection and treatment maybe provide novel pathways to refractory infections caused by bcterial biofilms.

OBJECTIVEThis research was to explore the difference between children with community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP) in the composition and antibiotic-resistance of pathogenic bacteria.

METHODS241 CAP and 116 HAP with positive sputum culture who were hospitalized from January to December in 2008 in Children's Hospital Affiliated to Suzhou University were selected in this study. The bacteria were identified by traditionally manual method and antibiotic sensitivity tests were performed by K-B method. The chi-square or Fisher's exact test were used for statistical test.

RESULTSIn 241 CAP, Streptococcus pneumoniae and haemophilus influenza accounted for (42.2%, 106/251) and (12.4%, 31/251) infection, respectively; however in 116 HAP, Enterobacteriaceae and Non-fermenters accounted for (88.2%, 127/144). In addition, methicillin-resistant Staphylococcus aureus weren't isolated, however, its detection rate was 66.7% in HAP. The drug resistance was 1.5 times higher in HAP than that in CAP for several types of antibiotics, such as ceftazidime (37.5% (6/16) vs 75.6% (31/41)), cefepime (37.5% (6/16) vs 78.0% (32/41)), aztreonam (50.0% (8/16) vs 90.2% (37/41)), cefoperazone/sulbactam (12.5% (2/16) vs 51.2% (21/41)) and piperacillin/tazobactam (12.5% (2/16) vs 56.0% (23/41)). Klebsiella pneumoniae isolated from HAP had higher drug resistance than that isolated from CAP against some antibiotics, for example, gentamicin (0 vs 63.6% (7/11)), SMZ + TMP (20.0% (1/5) vs 63.6% (7/11)) and cefoperazone/sulbactam (0 vs 54.5% (6/11)). We also found Enterobacter cloacae isolated from HAP showed high drug resistance than that isolated from CAP against imipenem (0 vs 46.7% (7/15)), aztreonam (9.1% (1/11) vs 60.0% (9/15)) and cefoperazone (18.2% (2/11) vs 80.0% (12/15)) and Pseudomonas aeruginosa from HAP had higher resistance than that from CAP against gentamicin (0 vs 50.0% (9/18)), amikacin (0 vs 38.9% (7/18)), ceftazidime (0 vs 55.6% (10/18)), cefepime (0 vs 50.0% (9/18)) and cefoperazone (33.3% (2/6) vs 94.4% (17/18)). The detection rates of ESBLs for Escherichia coli were 84.6% (11/13) and 93.3% (14/15) in CAP and HAP, respectively (χ(2) = 0.553, P > 0.05); while for Klebsiella pneumoniae, they were 81.3% (13/16) and 95.1% (39/41), respectively (χ(2) = 2.767, P > 0.05).

CONCLUSIONCAP was mainly comprised of Streptococcus pneumoniae and haemophilus influenza; while HAP was mainly comprised of Enterobacteriaceae and Non-fermenters. The drug resistance of gram-negative bacilli was higher in HAP than that in CAP.

Child ; Child, Preschool ; Community-Acquired Infections ; microbiology ; Cross Infection ; microbiology ; Drug Resistance, Bacterial ; Female ; Gram-Negative Bacteria ; drug effects ; isolation & purification ; Haemophilus influenzae ; drug effects ; isolation & purification ; Humans ; Infant ; Infant, Newborn ; Male ; Microbial Sensitivity Tests ; Pneumonia, Bacterial ; microbiology ; Pseudomonas aeruginosa ; drug effects ; isolation & purification

OBJECTIVETo investigate the molecule epidemic for 7 genes interrelated penicillin, erythromycin, tetracycline, vancomycin resistance of isolated Streptococcus pneumoniae (SP) in children at Suzhou area.

METHODS(1) Thirty-one pneumococcal isolates were collected from respiratory tract secretions of children with respiratory diseases from Nov 2002 to Apr 2003 at the Children's Hospital of Suzhou University (reference strain ATCC49619). (2) Penicillin susceptibility was determined by E-test, while erythromycin, tetracycline, vancomycin were determined by K-B disk. (3) The detecting of pbp2B, ermA/B, mefA, tetM, vanA, vanB genes by PCR, Sequencing pbp2B genes, Contrasting pbp2B DNA sequences among pneumococcal isolates and SP R6 [penicillin sensitive (www.ncbi.nlm.gov/nucleotide, NC-003098)].

RESULTSOf thirty-one isolates studied, the results were shown as follows; (1) Penicillin sensibility 38.7% (n = 12), penicillin resistance 61.3% (n = 19), pbp2B mutation 64.5% (n = 20); (2) Erythromycin sensibility 9.7% (n = 3), erythromycin resistance 90.3% (n = 28), ermA/B 71% (n = 22), mefA 32.1% (n = 10), ermA/B + mefA 87.1% (n = 27); (3) Tetracycline sensibility 9.7% (n = 3), tetracycline resistance 90.3% (n = 28), tetM 90.3% (n = 28); (4) Vancomycin sensibility 100% (n = 31), vanA, vanB all 0%.

CONCLUSIONAmong pneumococcal isolates at our area, penicillin, erythromycin, tetracycline resistance were high, vancomycin was sensitive. Detecting 7 genes interrelated penicillin, erythromycin, tetracycline, vancomycin resistance expressed genotypies for antibiotic resistances in pneumococcal isolates.

Anti-Bacterial Agents ; pharmacology ; Child ; China ; epidemiology ; DNA, Bacterial ; genetics ; Drug Resistance, Multiple, Bacterial ; genetics ; Erythromycin ; pharmacology ; Female ; Humans ; Male ; Microbial Sensitivity Tests ; Molecular Epidemiology ; Penicillin Resistance ; genetics ; Pneumococcal Infections ; epidemiology ; microbiology ; Streptococcus pneumoniae ; drug effects ; genetics ; isolation & purification ; Tetracycline Resistance ; genetics ; Vancomycin ; pharmacology

OBJECTIVETo investigate the beta-lactamase TEM gene of isolated Streptococcus pneumoniae (Sp) in Suzhou area.

METHODSTwenty-three strains of Sp were collected from respiratory tract secretions of children with respiratory diseases in Nov 2002 to Apr 2003 at Children's Hospital of Suzhou University (reference strain ATCC49619) to build TEM polymerase chain reaction (PCR) system (reference strain E. coli. 9-j53R1 with TEM gene) TEM gene of 23 strains was detected to comparo the sequences with published TEM gene sequences in GenBank for analyzing TEM gene model.

RESULTSTwenty-one strains had TEM gene with a positive rate of 91.3% (21/23). TEM-129 gene were confirmed from No.17 (SR017, penicillin resistance) TEM sequence. New discovered TEM-129 sequence had a modification (ATG[M]-->ATA[I]) at No.182 code and published (GenBank: www.ncbi.nlm.nih.gov/nucleotide, AY452662). TEM-1 genes were confirmed from other TEM sequences. New discovered TEM-1 gene of isolated Sp had been published (GenBank: www.ncbi.nlm.nih.gov/nucleotide, AY392531) too.

CONCLUSIONIsolated Sp had TEM gene (TEM-129, EM-1 genotype) with a positive rate of 91.3%. The result enriched the understanding of isolated Sp with penicillin resistance.

Base Sequence ; China ; epidemiology ; Drug Resistance, Bacterial ; genetics ; Female ; Genes, Bacterial ; genetics ; Humans ; Male ; Molecular Epidemiology ; Molecular Sequence Data ; Pneumonia, Bacterial ; epidemiology ; genetics ; microbiology ; Point Mutation ; Streptococcus pneumoniae ; enzymology ; genetics ; beta-Lactam Resistance ; beta-Lactamases ; genetics

OBJECTIVETo 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).

METHODMinimal 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).

RESULTAmong 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.

CONCLUSIONThe amino acid substitutions in or vicinal conserved sequence of PBP of SP increase MIC for beta-lactam antibiotics.

Amino Acid Substitution ; Aminoacyltransferases ; genetics ; Anti-Bacterial Agents ; pharmacology ; Bacterial Proteins ; genetics ; Microbial Sensitivity Tests ; Penicillin-Binding Proteins ; genetics ; Peptidyl Transferases ; genetics ; Streptococcus pneumoniae ; drug effects ; beta-Lactam Resistance ; genetics ; beta-Lactams ; pharmacology

OBJECTIVETo investigate the relation of pbp2B, ermB, ermA/B and mefA genes to penicillin and erythromycin resistance among isolated Streptococcus pneumoniae (Sp) in children.

METHODSTwenty-six strains of Sp were collected from September 2002 to April 2003 at the Children Hospital of Suzhou University. (1) Twenty-six pneumococcal isolates were obtained from respiratory tract secretions of children with respiratory diseases. (2) Susceptibility of the isolates to penicillin, cefuroxime, ceftriaxone, cefotaxime and erythromycin was determined by E-test. (3) The genes pbp2B, ermB, ermA/B and mefA of the isolates were detected with PCR. (4) The PCR product of pbp2B gene was sequenced. (5) DNA sequences of pbp2B of pneumococcal isolates were compared with those of SpR6 [penicillin sensitive (www.ncbi.nlm.gov/nucleotide, NC-003098)].

RESULTSAmong the 26 isolates studied, pbp2B gene mutation was found in 15(58%) isolates, all were point mutation of A, B, C and D genotypes which were seen in 11(73%), 2(13%), 1(7%) and 1(7%), respectively. The numbers of isolates susceptible to penicillin, cefuroxime, ceftriaxone and cefotaxime were 9(82%), 10(91%), 11(100%) and 11(100%), of 11 non-mutation isolates;numbers of isolates resistant to penicillin, cefuroxime, ceftriaxone, and cefotaxime were 13(87%), 11(73%), 1(7%) and 1(7%) out of 15 isolates with mutation.ErmB, ermA/B, mefA and erm/mef genes were positive in 9(35%), 16(62%), 7(27%) and 21(81%)isolates. MIC of erythromycin was 2 to > 256 mg/L among pneumococcal isolates with erm/mef genes.

CONCLUSIONAmong antibiotic resistant pneumococcal isolates in the area, the main basis of penicillin resistance was the mutation of pbp2B genes. Genotype A mutation had the highest rate among the isolates with mutation and manifested as resistance to penicillin and cefuroxime. Expression of either all or any of the ermA, ermB and mef genes led to erythromycin resistance. Antibiotics resistant Sp strains in this area are forming a challenge to efficacy of penicillin and erythromycin.

Aminoacyltransferases ; genetics ; Anti-Bacterial Agents ; pharmacology ; Bacterial Proteins ; genetics ; Child ; Drug Resistance, Bacterial ; Erythromycin ; pharmacology ; Humans ; Membrane Proteins ; genetics ; Methyltransferases ; genetics ; Penicillin Resistance ; Penicillin-Binding Proteins ; genetics ; Streptococcus pneumoniae ; drug effects ; genetics

OBJECTIVERotavirus is the single most common cause of severe dehydrating diarrhea in young children worldwide, but the pathogenesis and immunity against this disease are not completely understood. A prospective study was conducted to assess gene expression of toll-like receptors (TLR) in children with acute rotavirus diarrhea.

METHODSSeventy-five children with acute rotavirus diarrhea and 38 control children were enrolled in this study from Sep. 2004 to Jan. 2005. All the 75 patients had detailed records of clinical characteristics. Rotavirus antigen was detected by ELISA from stools. Peripheral blood mononuclear cells (PBMC) were separated by Ficoll reagent and RNA was extracted by Trizol. The levels of mRNA for five TLRs in PBMC were examined by fluorescent quantitative RT-PCR.

RESULTSPatients with acute rotavirus infection had elevated mean levels of TLR 2, 3, 4, 7, 8 mRNA expressions in PBMC within 3 days since onset of the disease, P less than 0.05. But only TLR 2, 3, 8 mRNA levels remained increased in patients within 7 or 14 days since onset (P less than 0.05). Mean levels of mRNA for TLR 4 in PBMC was higher in patients with more severe diarrhea including longer duration of diarrhea, more episodes of diarrhea per day and higher severity scores (P less than 0.05).

CONCLUSIONManifold TLR may play roles in the start-up and regulation of immune responses in children with acute rotavirus diarrhea. These findings will be helpful to further recognize immune response in Chinese children with rotavirus diarrhea and, consequently, may provide directions and insights that could prove critical to the prevention or treatment of this important disease.

Acute Disease ; Antigens, Viral ; analysis ; Child, Preschool ; Diarrhea ; genetics ; virology ; Enzyme-Linked Immunosorbent Assay ; Feces ; virology ; Gene Expression ; Host-Pathogen Interactions ; Humans ; Infant ; Leukocytes, Mononuclear ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Rotavirus ; immunology ; physiology ; Rotavirus Infections ; genetics ; virology ; Toll-Like Receptors ; genetics

ObjectiveTo observe the changes of fluoride content in serum,bone and urine after rats were exposed to single fluoride,single aluminum or fluoride combined with aluminum and to investigate the effects of different doses of aluminum on fluoride accumulation and excretion in rats.Methods Male Wistar rats were randomly divided into 9 groups based on 3 × 3 factorial design.Different doses of fluoride(NaF,0,50,200 mg/L)and(or) aluminum(AlCl3,0,100,200 mg/L) were administered to rats in each group by drinking water.The rats took food and water ad libitum during the experimental period.After feeding for 18 weeks,rats with obvious dental fluorosis were determined as successful establishment of animal model.The fluoride content in the serum,bones and urine were measured.Results Fluoride affected the fluoride content in serum,bones and urine(F=166.74,577.81,160.96,all P ＜ 0.01 ).The interaction of fluoride and aluminum on serum,bone and urinary fluoride were statistically significant (F =7.95,5.13,6.94,all P ＜ 0.01 ).When the fluoride level was 50 mg/L,the serum fluoride contents were [ (0.08 ± 0.03) and (0.08 ± 0.02) mg/L] in the aluminum levels of 0 and 100 mg/L groups,which was higher than that of the aluminum level of 200 mg/L group[ (0.04 ± 0.01)mg/L,F=7.14,5.78.all P＜ 0.05].The bone fluoride content in the 0 mg/L aluminum level group[ (1996.53 ± 383.73) mg/kg] was higher than that of the 100 and 200 mg/L groups[(1252.51 ± 189.08),( 1160.63 ± 129.63) mg/kg,F=20.54,24.56,all P ＜ 0.01 ].When the fluoride level was 200 mg/L,the bone fluoride contents were decreased with the increasing doses of aluminum[ (4668.70 ± 887.67),(3920.30 ± 528.31 ),(3297.64 ± 396.04) mg/kg].Between any two groups,the differences were statistically significant (F =15.59,52.31,14.38,all P ＜ 0.01 ).When the fluoride level was 50 mg/L,the urinary fluoride content in the 0 mg/L aluminum level group[ (34.054 ± 9.30)mg/L] was higher than that of the 100,200 mg/L groups[( 14.81 ± 6.32),(14.67 ± 3.42) mg/L,F =25.30,24.32,all P ＜ 0.01 ].When the fluoride level was 200 mg/L,the urinary fluoride contents in the 0,100 mg/L aluminum level groups[ (57.14 ± 21.38),(51.75 ± 8.39)mg/L] were higher than that of the 200 mg/L group[(34.839 ± 9.30) mg/L,F=30.04,20.31,all P ＜ 0.01 ].ConclusionsAluminum is an antagonist of fluoride.The antagonism could be enhanced as the dose of aluminum increased.In this study,aluminum could effectively counteract the absorption of fluoride in rat model when the ratio of fluoride to aluminum is 1 ∶ 2.