秀丽隐杆线虫-泛耐药肺炎克雷伯菌感染模型的建立

Abstract:

ObjectiveTo establish an infection model using Caenorhabditis elegans(C. elegans)-extensively drugresistant Klebsiella pneumoniae（XDRKP）system.MethodsClinically isolated XDRKP strains were used to infect C. elegans in the liquid killing assay, the nematode survival and the number of bacteria in C. elegans digestive tract was observed.ResultsC. elegans was significantly retarded after being infected by XDRKP, different concentrations of XDRKP led to different patterns of the worm death. Log-rank test showed that survival curves of C. elegans infected with 1.5×10⁶CFU/mL of XDRKP and E.coli OP50 (control) were not significantly different （χ2=0.08，P>0.05）; survival curves of C. elegans infected with 1.5×10⁷ CFU/mL, 1.5×10⁸ CFU/mL of XDRKP and E.coli OP50 were significantly different（χ2=229.37, 275.98，respectively, both P<0.001）. The survival rates of 1.5×10⁸ and 1.5×10⁷ CFU/mL XDRKP groups were both lower than that of the control group.  Supernatant suspension obtained from test was performed bacterial culture, identification and antimicrobial susceptibility testing, XDRKP was determined.  After being infected with XDRKP  4, 6, 12, and 24 hours, the total number of bacteria in C. elegans were（0.28±0.02）×105 CFU/mL,（0.50±0.38）×10⁵ CFU/mL,（1.73±0.56）×10⁵ CFU/mL, and （2.62±0.53）×10⁵ CFU/mL，respectively, the number of bacteria in C. elegans digestive tract was significantly different at different time points （F=1 363.39，P<0.001）.ConclusionThe infection model of C. elegansXDRKP is established successfully.