Kim Jeongjin, Ding Tian, Ahn Juhee
Department of Medical Biomaterials Engineering, Kangwon National University, Chuncheon, Gangwon 24341, Republic of Korea.
Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang University, Hangzhou, Zhejiang 310058, China.
FEMS Microbiol Lett. 2017 Jul 6;364(13). doi: 10.1093/femsle/fnx116.
This study was designed to evaluate the resistance phenotypes of β-lactamases-producing Klebsiella pneumoniae strains. The antibiotic susceptibility and β-lactamase activity of K. pneumoniae strains, including antibiotic-sensitive K. pneumoniae (KPWT), ciprofloxacin-induced resistant K. pneumoniae (KPCIP) and clinically isolated K. pneumoniae strains (KPCI237, KPCI263 and KPCI272) were determined in the absence and presence of β-lactamase inhibitors (BLI 489, sulbactam, clavulanate and tazobactam). All strains were highly resistant to ampicillin in the absence of β-lactamase inhibitors (MIC≥ 512 μg mL-1). In the presence of clavulanate, the MICs of ampicillin and piperacillin against KPWT were decreased by > 64-fold and 4-fold, respectively. The resistance of KPCI263 to cefotaxime, ceftazidime, ceftriaxone and piperacillin were increased in the presence of BLI-489. The antibiotic susceptibility of KPCI237 to β-lactams was not noticeably changed in the presence of β-lactamase inhibitor (clavulanate, sulbactam or tazobactam). KPWT, KPCIP and KPCI272 were positive for blaSHV, blaAmpC and blaFOX/MOX; KPCI237 for blaSHV and blaAmpC; and KPCI263 for blaSHV and blaOXA-48. The antibiotic susceptibility corresponded well with the results obtained from dual disc diffusion assay, which was in good agreement with the β-lactamase production. The results provide useful information for understanding the resistance phenotypes in association with β-lactamase production.
本研究旨在评估产β-内酰胺酶肺炎克雷伯菌菌株的耐药表型。在不存在和存在β-内酰胺酶抑制剂（BLI 489、舒巴坦、克拉维酸和他唑巴坦）的情况下，测定了肺炎克雷伯菌菌株的抗生素敏感性和β-内酰胺酶活性，这些菌株包括抗生素敏感的肺炎克雷伯菌（KPWT）、环丙沙星诱导的耐药肺炎克雷伯菌（KPCIP）以及临床分离的肺炎克雷伯菌菌株（KPCI237、KPCI263和KPCI272）。在不存在β-内酰胺酶抑制剂的情况下，所有菌株对氨苄西林均具有高度耐药性（MIC≥512μg mL-1）。在存在克拉维酸的情况下，氨苄西林和哌拉西林对KPWT的MIC分别降低了>64倍和4倍。在存在BLI-489的情况下，KPCI263对头孢噻肟、头孢他啶、头孢曲松和哌拉西林的耐药性增加。在存在β-内酰胺酶抑制剂（克拉维酸、舒巴坦或他唑巴坦）的情况下，KPCI237对β-内酰胺类抗生素的敏感性没有明显变化。KPWT、KPCIP和KPCI272的blaSHV、blaAmpC和blaFOX/MOX呈阳性；KPCI237的blaSHV和blaAmpC呈阳性；KPCI263的blaSHV和blaOXA-48呈阳性。抗生素敏感性与双纸片扩散试验的结果高度相符，这与β-内酰胺酶的产生情况高度一致。这些结果为理解与β-内酰胺酶产生相关的耐药表型提供了有用信息。
