Objective To analyze the resistance of Stenotrophomonas maltophilia to commonly used antibacterial drugs,and to investigate the existence status of 3 kinds of integron(Ⅰ,Ⅱand Ⅲ)and the carrying drug resistance gene cassettes so as to offer help for better preventing and controlling the infectious diseases caused by stenotrophomonas maltophilia in local place.Methods 51 strains of Stenotrophomonas maltophilia from clinical samples were collected and the minimum inhibitory concentration(MIC)of 17 kinds of antibacterial drugs to stenotrophomonas maltophilia was measured by the broth microdilution antifungal susceptibility test(Mi-AFST).3 kinds of integron(Ⅰ,Ⅱand Ⅲ)were amplified by PCR with primers designed according to registrated DNA se-quence in GenBank.The variable region products in the positive integron strains were amplified and performed the sequencing analy-sis.The homological comparison in the Genebank database was performed on the sequencing results for finding out what gene was included in variable domain of those integrons.Results (1)Among 51 strains of stenotrophomonas maltophilia,41 srains (80.39%) were collected from sputum samples,and the infected crowd was dominated by individuals aged over 60 years,38 strains accounted for 74.5%.In the department distribution,20 strains(39.22%)were collected from ICU,13 strains (25.49%)from the respiratory department and 6 strains(11 .76%)from the veteran cardres wards,which accounted for the larger proportion.(2)The drug suscep-tibility test demonstrated that stenotrophomonas maltophilia strains had the higher resistance to most of commonly used antibacteri-al drugs,some strains even showed the multi-drug resistance to over 9 kinds of antibacterial drugs.(3)The PCR gene amplification results showed that 7 strains (13.7%)were positive integronⅠ,while no strains containing integron Ⅱ or ⅢI were detected;the resistance genes carried in the variable region of integron I included the 5 kinds of aacA4,aadA1,catB8,dfrA17 and aphA15.Conclu-sion Stenotrophomonas maltophilias has relatively high resistance to majority of commonly used antibacterial drugs in clinic,and some strains show the muti-drug resitance.IntegronⅠis one of important factors for the multi-drug resistance of Stenotrophomonas maltophilias.

OBJECTIVE: Analysis of normal young people multiple stimuli ASSR (m-ASSR), single stimuli ASSR (s-ASSR), C-ABR, PTA threshold, exploratory investigation of relevance of hearing test combination thresholds (C-ABR combines with 0.5, 1.0 kHz s-ASSR) predict behavioral thresholds, using a within-subjects design. METHOD: Forty-three normal hearing adults (86 ears) were treated with pure tone audiometry (PTA), m-ASSR, 0.5, 1.0 kHz s-ASSR, C-ABR. Data were analyzed by SPSS 18.0 for bivariate correlation analysis. RESULT: There was significant correlation between thresholds of hearing test combination and PTA,and the correlation coefficient (r) were 0.803, 0.650, 0.649, 0.734 at 0.5, 1.0, 2.0 and 4.0 kHz; while the correlation coefficient (r) between thresholds of m-ASSR and PTA were 0.48, 0.64, 0.57, 0.64. CONCLUSION There is significant correlation between thresholds of hearing test combination and PTA, hearing test combination can be more accurate, more reliable assessment of adults with normal hearing threshold level.
Acoustic Stimulation ; Adolescent ; Adult ; Audiometry, Pure-Tone ; Auditory Threshold ; physiology ; Evoked Potentials, Auditory, Brain Stem ; physiology ; Female ; Humans ; Male ; Young Adult

Objective:To establish an animal model of pneumonia for research on clinical prevention and treatment of bacterial pneumonia by infecting immunocompromised rats with drug-resistant Acinetobacter baumannii ( Ab) strains. Methods:Drug-resistant Ab strains were selected. Forty-eight SD rats were randomly divided into four groups: normal group, cyclophosphamide control group (intraperitoneal injection of 45 mg/kg cyclophosphamide), bacterial infection group (intratracheal instillation of 1.5×10 8 CFU Ab suspension), and bacterial infection+ immunosuppression group (intraperitoneal injection of 45 mg/kg cyclophosphamide+ intratracheal instillation of 1.5×10 8 CFU Ab suspension). Flow cytometry analysis was used to detect the proportion of CD4 + , CD8 + and NK cells in rat peripheral blood before as well as 3 d and 7 d after infection. A lung function meter was used to detect peak inspiratory flow (PIF), peak expiratory flow (PEF), tidal volume (Vt ) and forced expiratory volume in the second second/forced vital capacity (FEV 200/FVC) at 3 d and 7 d after modeling. ELISA was used to detect the levels of IL-6, TNF-α and IL-10 in the alveolar lavage fluid. HE staining was used to observe the morphology of rat lung tissues in each group. Bacterial loads in rat lung tissues were counted by bacterial culturing. Results:A decrease in voluntary activity was observed in rats in the cyclophosphamide control group, bacterial infection group and bacterial infection+ immunosuppression group after modeling. Lung rales could be heard in the bacterial infection group and bacterial infection+ immunosuppression group. Compared with the normal group, the cyclophosphamide control group showed decreased proportion of CD4 + and CD11b + NK cells and increased CD8 + cells in peripheral blood; the bacterial infection group showed decreased PIF, PEF, Vt and FEV 200/FVC, increased IL-6 and TNF-α levels and decreased IL-10 level in the alveolar lavage fluid, and higher bacterial load in lung tissues with mild widening of alveolar walls and inflammatory cell infiltration ( P<0.05, P<0.01). Compared with the cyclophosphamide control group and the bacterial infection group, the bacterial infection+ immunosuppression group showed a lower proportion of CD4 + cells and a higher proportion of CD8 + cells in rat peripheral blood, decreased PIF, PEF, Vt and FEV 200/FVC, increased IL-6 and TNF-α levels and decreased IL-10 level in alveolar lavage fluid, higher bacterial load in lung tissues, and aggravated widening of alveolar walls and inflammatory cell infiltration ( P<0.05, P<0.01). The proportion of CD11b + NK cells in peripheral blood of rats in the bacterial infection+ immunosuppression group was significantly lower than that in the bacterial infection group ( P<0.05, P<0.01). Conclusions:A bacterial pneumonia model was successfully constructed by infecting rats with Ab alone or in combination with cyclophosphamide immunosuppression. In the model constructed with Ab and cyclophosphamide immunosuppression, the rats had more severe pneumonia, which might be related to the reduced cellular immune function and the aggravated bacterial infection in rat lung tissues by cyclophosphamide.