肺炎克雷伯菌铁载体对喹诺酮类抗生素耐药性的影响

Siderophores are small molecular substances producted by bacteria, mainly involved in ferric ion transportation and bacterial virulence, but the relationship between siderophores and drug resistance has not been reported. Objective: To explore the relationship between siderophores and quinolone resistance in bacterial. Methods: K-B disk diffusion method and microporous dilution method were used in determination of antimicrobial susceptibility in the clinical isolates. CAS agar and UV-visible spectrophotometric assay were used for qualitative and quantifiability detections of siderophore, respectively. Association between production of siderophores and quinolone resistance were statistically analyzed by using of SPSS. Results: According to the CAS agar plate assay, 70 clinical isolates of Klebsiella pneumoniae all producted siderophores, however the production of siderophores measured at 630 nm by using UV-visible spectrometric method were different. The isolates were grouped into high siderophore-yielding group and low siderophore-yielding group based on the median number. Siderophores in resistant strains of quinolone significantly higher than the sensitive strains (P<0.01). The rate of ciprofloxacin and levofloxacin resistance in K. pneumoniae from the high siderophore-yielding group were significantly higher than those in low siderophore-yielding group (P<0.01). Siderophore in Klebsiella pneumoniae is positively correlated with bacterial resistance to quinolones (P<0.01). Conclusion: Our data suggest that siderophores may be involved in bacterial resistance and interfere the sterilization process of antibiotics.