Obiective To study the clinical characteristics and therapeutic measures of the antibiotic associated diarrhea (AAD) in children with severe bacterial pneumonia. Methods The information of antibiotic use history in children with severe bacterial pneumonia from January 2013 to June 2013 was retrospectively analyzed. Results The incidence rate of AAD was 70.59%in children with severe bacterial pneumonia. According to the frequency, the third-generation cephalosporins, penicillin and carbapenems were the major causes of AAD. The percentage of the age≤3 y, the duration of antibiotic usage>7 d and the number of antibiotics≥2 were significantly higher in AAD children than in non-AAD children (χ2=89.81~119.45, P<0.001). All the patients were improved after cessation or change of antibiotics. Conclusions The incidence of AAD in children with severe bacterial pneumonia is high, which is related to the age, the duration of antibiotic usage and the combination use of antibiotics.

Objective To investigate the molecular epidemiology of CRAB isolated from children in wuhan. Methods Forty non-repetitive strains of CRAB were collected from hospitalized children of emergency department, neonatal medicine, cardiothoracic surgery, bone surgery, respiratory medicine and renal medicine in Wuhan children's hospital during December 2008 and May 2009. MIC values were PFGE; KPC, IMP, GIM, SPM, SIM, OXA-23, VIM genes and integrase gene were amplified by PCR and then sequenced to confirm the genotypes.; Plasmid conjugation experiment was used to study the transfer method of bacterial resistance and southern blot hybridization was used to target the resistance genes. Results Susceptible rates of 40 strains to gentamicin, tobramycin, amikacin, ciprofloxacin, levofloxacin, trimoxazole were 20%, 5%, 93%, 93%, 95%, and 23% respectively. Eleven types of clone were detected by PFGE,including 29 strains of type A clone, 2 strains of type B clone, and 1 strain for each type of C to K clone. Eleven isolates produced both IMP-4 and OXA-23 carbapemase. Twenty-six isolates only possessed OXA-23 carbapemase. Thirty-six strains carried class Ⅰ integron. The results of southern blot hybridization showed that Intl, IMP-4 and OXA-23 type were located on chromosome. Conclusions Type A clone of CRAB is the most common. OXA-23 and IMP-4 type are the major acquired carbapemases, especially the OXA-23 is the most common type. The horizontal transmission of OXA-23 and IMP-4 gene mediated by Int1 and the spread of type A resistant clone is the major way of the spread of carbapenem-resistant Acinetobacter baumannii in the region.

Objective To investigate the potential effect of Lactobacillus acidophilus (L. acidophilus) on prevention and treatment of neonatal mice infected with human rotavirus (HRV). Methods Sixty 4-day-old kunming mice were randomly divided into control group. HRV infected group, L. acidophilus pretreated group (treated before HRV infection ) and L. acidophilus treated group(treated after HRV infection). The manifestation and pathological changes in small intestine of neonatal mice were observed. The HRV antigen in the feces and intestines were measured by ELISA and fluorescent-focus assay, respectively. Results The severity and duration of diarrhea as well as mortality in L. acidophilus pretreated group and treated group were lower than those in HRV infected group. The duration of HRV-antigens shedding following infection was considerably prolonged in HRV infected group compared to that in L. acidophilus pretreated group and treated group. Furthermore, decreased expression of HRV antigen and little pathological changes in intestinal mucosa were found in L. acidophilus pretreated group and treated group when compared with HRV infected group. Conclusion L. acidophilus may be used as an alternative approach for the prevention and treatment of neonatal mice infected with HRV.

Objective To investigate the risk factors involved in the refractory pneumonia caused by multidrug resistant acinetobacter baumannii (MDRAb) in pediatric Intensive care unit (PICU).Methods From January 2009 to August 2011,115 patients with MDRAb pneumonia were treated in Department of Emergency,Wuhan Children's Hospital,Wuhan.Another 45 patients with negative MDRAb (NMDRAb)pneumonia served as control.The patients in the two goups were analyzed using univariate and multivariate Logistic regression to find out the risk factors for MDRAb infection.Results Among the 176 clinical strains of acinetobacter baumannii isolated,128 (72.73％) strains were MDRAb.After drug susceptibility tests,acinetobacter baumannii showed the rates of resistance to β-lactams antibiotics not including cefoperazone-sulbactam were more than 70％,and the rates of resistance to carbapenems antibiotics were higher than 90％.All rates of resistance to antibiotics of betalactams and carbapenems in MDRAb were higher than those in NMDRAb significantly.There were very low rates of drug-resistance found in Amikacin,Levofloxacin,Ciprofloxacin and Minocycline ( ＜20％ ).Multivariate logistic regression revealed that ICU stay,length of time for mechanical ventilation,anemia,hypoproteinemia and the use of carbapenems were independent risk factors involved in MDRAb pneumonia.Conclusions MDRAb was an important conditional pathogen with high rate of drug-resistance to many antibiotics leading to pneumonia in PICU.It increased the mortality of patients significantly.To control the infection of MDRAb was the key to increasing efficacy of treatment of pneumonia in PCIU.

Objective To study the pathogenic bacteria strains with drug-resistance prevailing in patients with ventilator-associated pneumonia(VAP)in Pediatric Intensive Care Unit(PICU)in order to provide a reasonable guidance to the clinical use of suitable antibiotics.Method A retrospective clinical study in 46 patients with VAP was carried out in PICU of Wuhan Children's Hospital between January 2008 and June 2010.The prevalent strains of the pathogenic bacteria with drug-resistance isolated from lower respiratory tract by aspiration were analyzed.Results In total,119 pathogenic microbial strains were isolated including Gram-negative bacilli(G-,65.55%),fungi(21.01%)and Gram-positive cocci(G+,13.45%).Among pathogens,the most common pathogenic strains were Acinetobacter baummannii, Escherichia coli,Klebsiella pneumoniae,candida albicans and coagulase-negative staphylococci.Antibiotic susceptibility tests indicated that the situation of the multiple drug-resistances to antibiotics found in G- and G+ Was serious. Most of G- were sensitive to ciprofloxacin, amikacin, imipenem, meropenem,cefoperazone-sulbaetam and piperacillin-tazobactam.The G+ cocci were 100% susceptibility to vancomycin, teicoplanin and linezolid.Fungi were almost sensitive to all the anti-funaus agents. Conclusions The oredominant oathogens of VAP were G- bacilli,and their multiple drug-resistances to antibiotics were the serious problems.The monitoring of the drugresistance should be emphasized, and the option of antibiotics should depend on the antibiotic sensitivity test.

Objective To investigate the distribution of acquired carbapenemases in carbapenemresistant strains of Klebsiella pneumoniae, and explore its role in epidemiology of nosocomial infection. Methods From November 2008 to March 2009, twenty clinical isolates of carbapenem-resistant Klebsiella pneumoniae were collected from children hospitalized in Wuhan children's hospital. MICs of antibiotics were tested by DNA of Klebsiella pneumoniae. Modified Hodge test was used to screen strains producing carbapenemases,combined imipenem(IPM)-EDTA , meropenem(MEM)- EDTA and ceftazidime(CAZ) - EDTA double-disk synergy test (DDST) were used to detect metallo-β-lactamase-producing. PCR amplification of the carbapenemase and integrase genes, and sequencing were performed. Plasmid conjugation transfer experiments and Southern hybridization were applied to study the mode of drug resistance transmission. Results Four types of Klebsiella pneumoniae were detected by PFGE, type A consisted of 5 strains, including 3 strains of type Al and 2 strains of type A2), type B (2 strains), type C (12strains) and type D (1 strain). Type A and C were the main drug resistant clones. Eight strains of Klebsiella pneumoniae carried both KPC-2 and IMP-4 genes, 10 strains carried IMP-4 gene, 2 strains carried KPC-2 gene. None of NDM-1 ,GIM, SPM, SIM, OXA-23, and VIM carbapenemase genes was detected in 20 isolates. All of 20 isolates carried lntl which were found to be located on bacterial chromosome by Southern blot. Conclusions KPC-2and IMP-4 genes are the major carbapenemase genes in Klebsiella pneumoniae isolated in Wuhan.Transmission of drug resistance is mainly through vertical transmission of type C resistant clone and horizontal transmission of Intl on bacteria chromosome.

Objective To study the immune regulatory effect of natural killer cell(NKT) in the early stage of murine liver injury induced by type 5 adenovirus(Ad5). Methods Animal models were con-structed by injected C57BL/6 mice with 1.5×109-3×109 PFU Ad5 into the tail vein. Liver injury of mouse at day 0, 1, 2, 3, 4, 5 after infection was determined by HE staining and serum ALT/AST(alanine amin-otransferase/aspartate aminotransferase) level. Flow cytometry analysis was used to measure the proportion of lymphocytes, expression of Fas/FasL on the surface of NKT cells and level of IL-4, IFN-γ/in NKT cell plasma in the infected mouse liver. RT-PCR was applied to semi-quantify the chemokines and their receptors mRNA in infected mouse liver. Results NKT cells of mouse increased significantly at day 1 after infected with high titer Ads(3×109 PFU), expression of FasL on NKT cell and plasma IL-4, IFN-γ/level in NKT cells were also up-regulated, hence the obviously infiltration of lymphocytes in routine liver. Comparing with high titer Ads infection, low titer Ads infection (1.5×109 PFU) lead to little change of NKT cell proper-tion, and fewer infiltration of lymphocytes in murine liver. Hepatic chemokine RANTES, 1P-10, and MIP-1β mRNA expression in C57BL/6 was up-regulated 2 d after intravenous administration of 3×109 PFU Ad5. Corresponding chemokine receptor CCR5, CCR1, CXCR3 mRNA expression was up-regulated 3 d after in-fection. Conclusion NKT cells play an important role in lymphocytes recruitment into the liver of mouse in-fected with AdS, which may relate to up-regulatio of the plasma IL-4, IFN-γ level and expression of FasL of NKT cells, therefore facilitating the production of chemokines, e.g. IP-10 and Mig.

OBJECTIVE To analyze the distribution and anti-microbial resistance profile of pathogenic bacteria isolated from hospitalized neonates in Wuhan area.METHODS The strains of bacteria isolated from neonates in hospitalization of Wuhan area from 2006 to 2007 were identified by VITEK 32 automatic bacteria system and antimicrobial susceptibility test was performed by Kirby-Bauer method.The standards of NCCLS issued in 2006 were used to assess the results of antimicrobial susceptibility.RESULTS A total of 3892 strains of bacteria were isolated from 10053 specimens,the positive rate was 38.7%.The Gram-positive cocci and Gram-negative bacilli accounted for 41.0% and 55.2%,respectively.The leading 8 species on the list of isolated strains in the two years accounted for 90.8% of all the isolated strains.MRCNS accounted for 68.6% of coagulase negative staphylococcus,and the MRSA kept a low rate(2.6%) in Staphylococcus aureus.The infection rate of newborn by Enterococcus in blood was remarkably higher than that of the past report in this area.The ?-lactamases-producing Escherichia coli and Klebsiella pneumoniae were accounted for 46.9% and 34.7%,respectively.CONCLUSIONS The distribution and anti-microbial resistance of hospitalized neonates in Wuhan area have regional and group characteristics;it′s necessary to strengthen monitoring the regional epidemic characteristic status and the drug-resistant status of the pathogenic bacteria among neonates.