摘要
目的检测新型抗菌剂硝酸镓(gallium nitrate,GaN)对耐碳青霉烯肺炎克雷伯菌(carbapenem-resistant Klebsiellapneumonia,CRKP)生长及其生物膜(biofilm,BF)的抑制作用。方法收集2015—2016年安徽省地区34家医院临床分离的CRKP共82株,采用VITEK-2Compact全自动微生物分析系统进行细菌鉴定,琼脂倍比稀释法进行药敏试验;微量肉汤稀释法测定GaN对CRKP的最低抑菌浓度(minimal inhibitory concentration,MIC);96孔板结晶紫染色法检测82株实验菌株BF的A570值,筛选出BF强阳性菌株;检测1/2MIC的GaN对BF强阳性菌株的BF形成的抑制作用。比较GaN与庆大霉素(gentamicin,GEN)分别对CRKP的BF形成的抑制作用。激光共聚焦扫描显微镜观察GaN作用下的菌株生物膜三维立体结构。结果临床分离的CRKP呈多重耐药。GaN对82株CRKP的MIC范围为0.0625~2μmol/mL,其中MIC50、MIC90分别为0.25和0.5μmol/mL。BF强阳性菌株所占比例为37.8%(31/82)。三维立体图片显示CRKP在不同GaN浓度作用下BF形成的量不同。1/2MIC的GaN可显著抑制CRKP的BF形成。GaN对CRKP的BF形成的抑制作用优于GEN。结论GaN对CRKP生长及其BF有明显抑制作用。
Objective To study the inhibitory activity of gallium nitrate (GaN) on the bacterial growth and biofilm formation of carbapenem-resistant Klebsiella pneumoniae (CRKP). Methods The 82 clinical CRKP isolates were collected from the 34 hospitals of Anhui province from 2015 to 2016. The VITEK 2 Compact automated microbial analyzer was employed to conduct the bacterial identification. The minimal inhibitory concentrations (MIC) of 17 antibacterial drugs for these isolates were determined by the agar double dilution assay. The MIC of GaN was determined by the Micro-dilution method. The crystal violet staining assay was used to measure the A570 of CRKP in order to screen out strong biofilm-positive strains, and to test inhibitory effects of GaN (1/2MIC) on BF formation in 96-well plates. To compare the effects of Gallium nitrate with those of gentamicin on the biofilm formation of CRKP. The BF three-dimensional structure was visualized using the Confocal Laser Scanning Microscope. Results The clinical CRKP isolates demonstrated multidrug-resistance. In this study, the MIC of GaN for the 82 isolates was found to be in the range of 0.0625 to 2μmol/mL. The MIC50 was 0.25μmol/mL. The MIC90 was 0.5μmol/mL. The strong biofilm-positive strains accounted for 37.8%(31/82). Scanning electron microscopy imaging results revealed changes in amount of BF formation when the bacterial treated with GaN at different concentrations. The images demonstrated that GaN (1/2MIC) could significantly inhibit the biofilm formation of CRKP. The effects of gallium nitrate on the biofilm formation was superior to those of gentamicin. Conclusion GaN could significantly inhibit the growth and BF formation of CRKP.
作者
顾毅
刘周
徐方明
盛男
赵亚运
孙凯莉
刘艳艳
叶英
李家斌
Gu Yi;Liu Zhou;Xu Fang-ming;Sheng Nan;Zhao Ya-yun;Sun Kai-li;Liu Yan-yan;Ye Ying;Li Jia-bin(Department of Infectious Diseases, the First Affiliated Hospital of Anhui Medical University,Anhui Center for Surveillance of Bacterial Resistance, Hefei 230023)
出处
《中国抗生素杂志》
CAS
CSCD
2019年第4期461-466,共6页
Chinese Journal of Antibiotics
基金
国家自然科学基金(No.81673242)
关键词
肺炎克雷伯菌
生物膜
硝酸镓
碳青霉烯
Klebsiella pneumoniae
Biofilm
Gallium nitrate
Carbapenem
