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 investigate the distribution of the genes of two major metallo-beta-lactamases (MBL; i.e., IMP and VIM) and class 1 integrons (intI) in the clinical imipenem-resistant Pseudomonas aeruginosa, a total of 65 isolates, from a university hospital in Sichuan between December 2004 and April 2005 were screened for MBL genes by PCR using primers specific for bla ( IMP-1 ), bla ( VIM ) and bla ( VIM-2 ) genes. The MBL-positive isolates were further assessed for class 1 integrons by PCR using specific primers. The nucleotide sequences of several PCR products were also determined. The results revealed that the bla ( VIM ) gene was found in 81.5% (53/65) of all isolates, bla ( VIM-2 ) gene was found in only 1 isolate and the intI gene was observed in 45.3% (24/53) of bla ( VIM )-positive isolates. One isolate carried simultaneously both bla ( IMP-1 ) and intI genes, and to the best of our knowledge this is the first report of such isolate in southwest China. These observations highlight that the genes for VIM beta-lactamase and class 1 integrons were predominantly present among the imipenem-resistant P. aeruginosa tested, confirming the current widespread threat of imipenem-resistant, integron-borne P. aeruginosa.
Anti-Bacterial Agents/pharmacology ; China ; DNA Primers/chemistry ; Drug Resistance, Bacterial ; Gene Expression Regulation, Bacterial ; Imipenem/*pharmacology ; Integrons ; Microbial Sensitivity Tests ; Models, Genetic ; Pseudomonas Infections/genetics ; Pseudomonas Infections/*microbiology ; Pseudomonas aeruginosa/*metabolism ; Sequence Analysis, DNA ; beta-Lactamases/*metabolism

To investigate the distribution of the genes of two major metallo-β-lactamases (MBL; i.e., IMP and VIM) and class 1 integrons (intI) in the clinical imipenem-resistant Pseudomonas aeruginosa, a total of 65 isolates, from a university hospital in Sichuan between December 2004 and April 2005 were screened for MBL genes by PCR using primers specific for blaIMP-1, blaVIM and blaVIM-2 genes. The MBL-positive isolates were further assessed for class 1 integrons by PCR using specific primers. The nucleotide sequences of several PCR products were also determined. The results revealed that the blaVIM gene was found in 81.5% (53/65) of all isolates, bla gene was found in only 1 isolate and the intI gene was observed in 45.3% (24/53) of blaVIM-positive isolates. One isolate carried simultaneously both blaIMP-1 and intI genes, and to the best of our knowledge this is the first report of such isolate in southwest China. These observations highlight that the genes for VIM β-lactamase and class 1 integrons were predominantly present among the imipenem-resistant P. aeruginosa tested, confirming the current widespread threat of imipenem-resistant, integron-borne P. aeruginosa.

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.