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Objective To investigate the antimicrobial resistance profile of the clinical isolates collected from selected hospitals across China. Methods Twenty-nine general hospitals and five children's hospitals were involved in this program. Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby-Bauer method or automated systems. Results were interpreted according to CLSI 2017 breakpoints. Results A total of 190 610 clinical isolates were collected from January to December 2017, of which gram negative organisms accounted for 70.8％ (134 951/190 610) and gram positive cocci 29.2％ (55 649/190 610). The prevalence of methicillin-resistant strains was 35.3％ in S. aureus (MRSA) and 80.3％ in coagulase negative Staphylococcus (MRCNS) on average. MR strains showed much higher resistance rates to most of the other antimicrobial agents than MS strains. However, 91.6％ of MRSA strains were still susceptible to trimethoprim-sulfamethoxazole, while 86.2％ of MRCNS strains were susceptible to rifampin. No staphylococcal strains were found resistant to vancomycin. E. faecalis strains showed much lower resistance rates to most of the drugs tested (except chloramphenicol) than E. faecium. Vancomycin-resistant Enterococcus (VRE) was identified in both E. faecalis and E. faecium. The identified VRE strains were mainly vanA, vanB or vanM type based on phenotype or genotype. The proportion of PSSP or PRSP strains in the non-meningitis S.pneumoniae strains isolated from children decreased but the proportion of PISP strains increased when compared to the data of 2016. Enterobacteriaceae strains were still highly susceptible to carbapenems. Overall, less than 10％ of these strains (excluding Klebsiella spp.) were resistant to carbapenems. The prevalence of imipenem-resistant K. pneumoniae increased from 3.0％ in 2005 to 20.9％ in 2017, and meropenem-resistant K. pneumoniae increased from 2.9％ in 2005 to 24.0％ in 2017, more than 8-fold increase. About 66.7％ and 69.3％ of Acinetobacter (A. baumannii accounts for 91.5％) strains were resistant to imipenem and meropenem, respectively. Compared with the data of year 2016, P. aeruginosa strains showed decreasing resistance rate to carbapenems. Conclusions Bacterial resistance is still on the rise. It is necessary to strengthen hospital infection control and stewardship of antimicrobial agents. The communication between laboratorians and clinicians should be further improved in addition to surveillance of bacterial resistance.
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Objective To investigate the establishment,operation and performance of external quality assessment(EQA) system for microbial morphology and detection of special drug-resistance in clinical laboratory,and explore the value of the developed system in clinical application.Methods The pictures of known bacteria and fungi colony,gram staining and acid-fast staining from clinical microbiology were distributed to the participating laboratories in Gansu province twice a year at regular intervals.The pictures of standard knowledge points from CLSI,such as special drug resistance were distributed simultaneously.All the participating laboratories were required to complete the interpretation for the pictures and report their resuhs in a scheduled time.Then the resuhs were summarized and analyzed as 3 modes:complete consistency,general consistency and non-consistency.Results During the 2 years when the EQA system for microbial morphology and detection of special drug-resistance were performed for 24 times,the rate of annual complete consistency increased year by year and reached to 91.3％ in 2015.Conclusion The EQA system based on the examinations of microbial morphology and CLSI standard knowledge points for clinical laboratory may supervise the staff of clinical microbiology laboratories in the hospitals at second grade or above to master the skills of morphological identification and learn CLSI knowledge points,so their professional skills of clinical microbiology could be comprehensively improved.
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ObjectiveTo established a cell line that expresses hBD1 stably,and detected the antimicrobial activity of the hBD1 to the muhidrug resistant bacterial strains.MethodsRecombinant plasmid was introduced into COS-7 cells by lipofectamine,cells were selected in culture medium containing G418 to acquired the monoclonal cell lines,total RNA were extracted from the cultured cells,expression levels of hBD1 mRNA was identified by RT-PCR,collected the supernatant solution of the cultured cell,expression levels of protein was identified by Western blot.Put the expression products and resistant organisms mixed together,after incubation in different times in 37℃,coating the mixtures in LB flat,then obtained the ratios between colonies number of experimental groups and colonies number of control groups,put those ratios as the survival rate of the drug resistance bacterias.Results The monoclonal cell lines had obtained after screened with G418,the hBD1 gene could be detected both at transcriptional and protein levels,Under the influence of expression product hBD1,survival rate of muhidrug-resistant Acinetobacter baumannii,multidrug-resistant Escherichia coli and multidrug-resistant Klebsiella pneumoniae could reduced to 9%,22% and 50%,but survival rate of multidrug-resistant Stenotrophomonas maltophilia is not have apparente difference with the control group.ConclusionThe stably-transfected cell line of hBD1 was successfully constructed,and the expression products of hBD1 showed the antimicrobial activity toward multidrug resistant bacterial strains.