Objectives To investigate antimicrobial resistance and beta-lactamase production of Moraxella catarrhalis isolates from respiratory tract in children and to understand the characteristics of BRO beta-lactamase gene. Methods From June 2011 to Sep-tember 2012, 401 Moraxella catarrhalis isolates were obtained from respiratory tract in children. Minimum inhibitory concentrations (MIC) of commonly-used antibiotics were determined by microbroth dilution assay, and beta-lactamase production was detected by Nitroceifn disk test. PCR combining restriction endonuclease analysis was employed to do the BRO genotyping. Results 96.5%iso-lates were beta-lactamase positive (387/401), MIC (MIC50/MIC90) values and resistant rates of beta-lactamase producing isolates were higher than those of non beta-lactamase producing isolates for ampicillin, cefaclor and cefuroxime (P<0.05). The positive rate of BRO gene was 99.2%in beta-lactamase producing isolates (384/387), consisting of 93.0%BRO-1 isolates and 7.0%BRO-2 isolates. MIC50 and MIC90 values of BRO-1+isolates were higher than those of BRO-2+isolates for ampicillin, cefaclor, cefuroxime and azithromycin. Conclusions The beta-lactamase production rate is high in Moraxella catarrhalis isolates from respiratory tract in children. BRO-1 type was the dominant genotype of beta-lactamase producing isolates, having more inlfuence than BRO-2 type in the inlfuence on some beta-lactams and macrolides.

Objective To observe the effect of bifidobacterial lipoteichoic acid (BLTA) on cellular immunity of mice with systemic Candida albicans infection .Methods Systemic C .albicans infection model in immunocompromised mice were established by injecting standard strain of C .albicans via caudal vein .The effects of BLTA on thymus index ,spleen index ,splenic lymphocytes proliferation and NK cells cytotoxicity were observed as well as serum levels of cytokines .Results After systemic C .albicans infec‐tion in immunocompromised mice ,thymus index ,spleen index and splenic lymphocytes proliferation activity were decreased (P>0 .05) ,NK cells cytotoxicity was decreased significantly (P< 0 .05) ,IL‐2 ,IL‐4 and INF‐γ levels were increased slightly (P>0 .05) ,IL‐10 levels were increased significantly(P<0 .05) .After treated by BLTA ,thymus index ,spleen index ,splenic lymphocytes proliferation and NK cells cytotoxicity were increased significantly (P<0 .01) ,IL‐2 and INF‐γ levels were increased significantly (P<0 .05) ,IL‐4 levels showed little change ,IL‐10 levels were decreased significantly (P<0 .01) .Conclusion BLTA can improve immune status of immunocompromised mice ,which can restore and enhance the compromised cellular immunity of mice with sys‐temic C .albicans infection .

To optimize the configuration of the conventional SE and FSE sequence parameters in low field MRI. With the combination of larger vision, relatively thinner slice thickness, small number of excitation (NEX = 1 or 2), the signal-to-noise ration and the spatial resolution on follow-up images are moderate, the scan time is significantly shorter along with fewer motion artifacts, the check success rate is improved.
Equipment Design ; Magnetic Resonance Imaging ; instrumentation ; methods

After participating in the student selection training and on-site refereeing of the clinical examination skills competition for college students in Sichuan-Chongqing region twice in succession, the author combined the on-site performance and competition results of the participating students with pre-match training experience and normal teaching experience. A comprehensive analysis found that the students' proficiency in basic testing skills, psychological quality and humanistic quality have an important impact on the results of the competition. Teachers should not only pay attention to the quality of basic skills training and theoretical knowledge teaching in practical teaching, but also pay attention to the cultivation of students' teamwork ability and good working habits. Therefore, the clinical laboratory skills competition has a strong leading role in promoting the education and teaching reform of medical laboratory technology and improving the quality of professional practice teaching. It is hoped that more medical colleges and universities will pay attention to and participate in it, and further promote the development of practical teaching of medical laboratory technology.

Objective:To study the molecular biological characteristics of isolates from the infection site and isolates colonizing in anterior nares of children with invasive Staphylococcus aureus (SA) infection, and to analyze the concordance between the two types of strains from different sources. Methods:A total of 45 strains were collected from children with invasive SA infection treated in the Pediatric Ward of Sichuan Provincial Maternal and Child Health Care Hospital from January 2019 to August 2019, and 28 colonization isolates were obtained from the anterior nares of these patients.The susceptibility test was carried out by broth dilution method.The drug resistance genes mecA and blaZ and the virulence gene panton-valentine leucocidin( pvl) were detected by PCR.The homology of infective and colonizing isolates was detected by pulsed-field gel electrophoresis(PFGE)typing technique. Results:Colonization of SA was found in the nasal vestibule of 62.2% (28/45 cases) of patients with invasive SA infection.A total of 40.0% (18/45 strains) of the infective isolates and 32.1% (9/28 strains) of the colonizing isolates were Methicillin-resistant SA (MRSA), and the difference was not statistically significant( P>0.05). The resistance of infective isolates to Clindamycin, Azithromycin and Erythromycin was stronger than that of colonizing isolates, the difference of drug resistance rate was statistically significant( χ2=7.114, 7.820, 5.359, all P<0.05). There were no differences in the carrying rates of the drug resistance gene blaZ and the virulence gene pvl between the infective and colonizing bacteria( P>0.05). Phenotypically, Methicillin-susceptible SA (MSSA)was more susceptible to concordant colonization than MRSA[16.7%(3/18 cases) vs.48.1%(13/27 cases), χ2=4.671, P<0.05]. PFGE indicated that patients with invasive MSSA infection were significantly more likely to have a concordant MSSA colonization isolate in their anterior nares, compared with patients with invasive MRSA infection[59.3%(16/27 strains) vs.27.8%(5/18 strains), χ2=4.301, P<0.05]. Conclusions:The infective and colonizing strains of invasive SA show no difference in their resistance to some anti-biotics, but they carry almost the same number of drug resistance and virulence genes.Compared with those with MRSA infection, patients with MSSA infection are more likely to have concordant colonizing isolates.It is of potential clinical significance to screen the colonizing SA strains in patients with invasive SA infection.