耐碳青霉烯類肺炎克雷伯菌生物膜形成及多黏菌素B聯合替加環素的體外抗菌活性

中圖分類號：R978.1 文獻標志碼：A

Carbapenem-resistant Klebsiella pneumoniae biofilm formation and in vitro antimicrobial activity of polymyxin B in combination with tigecycline

Liu Jiel and Zhao Jianping2 （1 InnerMongoliaClinical MedicalCollege，InnerMongoliaMedical University，Hohhot010050; 2 Department ofLaboratory Medicine， Inner Mongolia People's Hospital，Hohhot 010010）

Abstract Objective To analyze the relationship between the biofilm formation capacity of Klebsiella pneumoniae （KPN）and carbapenem antibiotic susceptibility，and evaluated the antimicrobial efect of polymyxin B（PMB）and tigecycline （TGC） in vitro against clinically isolated carbapenem-resistant Klebsiella pneumoniae （CRKP）.MethodsThe abilityof 66 KPN strains to form biofilm and thecorrelation between KPNbiofilm formation ability and carbapenem susceptibility were analyzed bycrystal violet staining method;the minimum inhibitory concentration of PMB and TGC against 31 clinical isolates was determined by broth dilution and checkerboard dilution，and some inhibitory concentration index was calculated.ResultsThe biofilm formationrate in the 66 KPN strains was 90.91% .The main specimen types of the biofilm-positive strains were sputum （ 60% andbronchial lavage fluid （18.33%） . The ICU （36.67%） was the major distributed department. The production rate of 31 CRKP strains was 90.63% .The35carbapenem-susceptible K. pneumoniae （CSKP） biofilm formation rate was 88.57% .There was no difference in biofilm formation ability between the CRKP and CSKP groups （Pgt;0.05） .The CRKP isolateswere obtained mainly from malepatients.TheICU （64.52%） ）wasalso the major distributed department. The specimens were mainly derived from sputum （51.61%） and bronchial lavage fluid （35.48% ）. 31 CRKP mainly showed additive and synergistic effects，with 67.74% and 22.58% ，respectively，and the combination effect of the two drugs was 9.68% with no antagonistic efect. ConclusionKPN biofilm isolated in this hospital had strong formation capacity and should attact clinical atention; theantibacterial effect of PMBandTGCin vitro was mainly synergistic and aditive to CRKP.

Key WordsKlebsiella pneumoniae; Carbapenemresistant; Biofilm; Polymyxin B; Tigecycline; Drug combination

據報道，肺炎克雷伯菌（Klebsiellapneumoniae，KPN）是全球醫院感染相關的主要細菌病原體之一[]。碳青霉烯類藥物的廣泛應用，促使耐碳青霉烯肺炎克雷伯菌（carbapenem-resistantK.pneumoniae，CRKP）的出現并廣泛傳播，CRKP長期以來一直是臨床抗菌感染中的一個棘手問題[2-3]，1988年LeChevallier等[4]首次描述了KPN和生物膜形成現象，KPN形成生物膜后，黏附于各類醫療器材引起傳播，膜內細菌受到保護可在惡劣環境中長時間存活，逃避宿主免疫防御同時也使細菌具有更高水平的耐藥性。Alcantar-Curiel等[5]的一項研究提出，抗生素耐藥性和細菌形成生物膜的能力在肺炎克雷伯菌的全球傳播中發揮重要作用，生物膜作為細菌耐藥的一種重要機制，但目前其形成能力與肺炎克雷伯菌對碳青霉烯類抗菌藥物敏感性關系的相關研究較少。因此，本研究選取住院患者送檢標本中分離培養并鑒定的KPN為研究對象，檢測生物膜形成能力及統計分析其分布情況，探究生物膜形成能力與碳青霉烯類抗生素敏感性的關系，以期為醫院感染的控制提供理論依據。有相關研究表明，多黏菌素B（polymyxinB，PMB）和替加環素（tigecycline，TGC）似乎是治療CRKP感染的最后選擇，但仍需要考慮幾個因素，如腎毒性、體內可用血漿濃度和治療期間耐藥性的增加[4-5]，這給臨床治療帶來極大的挑戰，因此，聯合用藥成為最佳選擇，我們采用體外聯合藥敏試驗了解PMB與TGC聯合使用是否能在體外有效抑制細菌生長。

1材料與方法

1.1材料

1.1.1 標本來源

收集本院2022年10月—2023年10月臨床分離的KPN菌株，剔除同一患者的重復菌株，采用紙片法將菌株保存于 -80°C 冰箱。……