治疗产Ⅰ型酶肠杆菌科菌下呼吸道感染抗菌药物选择

Choice of antibacterial agents in the treatment of lower resriratory tract infection due to inducible enterobacteriaceae

对我院3年来收治的确诊为可产型酶肠杆菌科菌下呼吸道感染94例患者,回顾性比较了头孢呋新、头孢噻肟、头孢他啶、亚胺培南、环丙沙星等5种抗菌药物临床疗效、细菌清除率,比较了治疗前分离的117株可产型酶肠杆菌科病原菌的抗菌活性和对各自治疗无效病例未清除菌的抗菌活性与耐药率变化;分析了耐头孢菌素未清除菌与其它抗菌药物间交叉耐药情况;最后对经验性或替换用药提出了建议。结果表明:亚胺培南有效率最高(81.8%),其次为环丙沙星(79.2%);3种头孢菌素间比较无明显差异(P>0.05)。亚胺培南(86.7%)和环丙沙星(81.5%)的细菌清除率分别与头孢呋新(45.5%)和头孢噻肟(53.6%)比较差异显著(P<0.05或0.01)。体外抗菌活性最强者为环丙沙星,其次为亚胺培南。5种抗菌药物对治疗无效病例未清除菌均表现出抗菌活性的降低;提示治疗前尚且敏感的细菌在接触药物过程中产生了耐药性。3种头孢菌素间呈现明显交叉耐药,除耐头孢他啶分离菌外,耐其它2种头孢菌素未清除菌分别与亚胺培南和环丙沙星仅表现为很小部分交叉耐药。上述结果提示,经头孢菌素治疗失败病例需要替换用药时,应尽可能避免选用同类药物,一旦证实病原菌产生型酶,就应严格控制选用全部β内酰胺类抗菌药物。

The efficacy of cefuroxime, cefotaxime, ceftazidime, imipenem and ciprofloxacin in the treatement of 94 hospitalized patients with lower respiratory tract infection (LRTI) due to inducible enterobacteriaceae being susceptable before therapy in recent three years was evaluated retrospectively. Comparative activity to the 117 strains isolated from the patients in prior of therapy, and comparative changes of MICs and resistant rate in vitro of these agents to the strains persisted in the infection site of failure cases were studied. Finally,the strains not eradicated by each cephalosporin and cross resistant to others were analysed.The results demonstrated imipenem has the hightest clinical response rate (81.8%). There are no statistical differences in three cephalosporins ( P >0.05). Bacteriological response rate of imipenem (86.7%) and ciprofloxacin (81.5%) are significantly higher in statistics than cefuroxime (45.5%) and cefotaxime ( 53.6% ) ( P <0.05 or 0.01). Ciprofloxacin has the strongest activity to the strains isolated before therapy. At the same time, imipenem is stronger than cefuroxime, cefotaxime and ceftazidime. It is considered that the strains not eradicated from the failure patients become resistant during the treatment, and MICs are increased simultaneously. Three cephalosporins show evident of cross resistance. Except the ceftazidime resistant strains, the others resistant to cefuroxime and cefuroxime and cefotaxime show little cross resistance with imipenem and ciprofloxacin. The conclusion indicates imipenem and ciprofloxacin are better choice than second or third generation cephalosporine in the treatment of LRTI due to inducible enterobacteriacae.In the case of type Ⅰ β Lactamases producing pathogens, the use of β lactam antibiotics should be avoided.