临床分离奇异变形杆菌耐药性及产ESBLs菌株的流行现状

Antimicrobial susceptibility of Proteus mirabilis isolates and prevalence of ESBLs producers

目的了解临床分离奇异变形杆菌的耐药性及产超广谱β-内酰胺酶(ESBLs)的流行情况,为临床治疗提供实验室依据。方法收集临床分离的奇异变形杆菌共33株,用琼脂稀释法检测其对14种抗菌药物的耐药性,并用超广谱β-内酰胺酶确证试验筛选出产ESBLs细菌。结果 33株奇异变形杆菌对亚胺培南耐药率为0、对头孢唑啉耐药率为100%,对哌拉西林、头孢呋辛、头孢他啶、头孢噻肟、头孢吡肟、氨曲南、阿米卡星、庆大霉素和氯霉素耐药率分别为12.1%、30.3%、24.2%、27.3%、18.2%、21.2%、12.1%、18.2%和48.5%,氟喹诺酮类抗菌药物耐药率较高,加替沙星、环丙沙星和左氧氟沙星耐药率分别为45.5%、39.4%和39.4%;产ESBLs菌株检出率为18.2%(6/33),除了头孢唑啉、哌拉西林、亚胺培南外,产ESBLs菌株的耐药率比非产ESBLs菌株都有不同程度地增加(P<0.01)。结论临床分离奇异变形杆菌对亚胺培南均敏感,对头孢唑啉均耐药,对其他抗菌药物均有不同程度耐药,产ESBLs菌株的检出率高,且对抗菌药物的耐药程度比非产ESBLs菌株高。

Objective To evaluate the susceptibility of clinical isolates of Proteus mirabilis to common antimicrobial agents, exam- ine the incidence of ESBL-producing, and provide reference data for clinical therapy. Methods Thirty-three strains of Protezts mirabilis isolates were tested for minimum inhibitory concentrations （MICs） to 14 antimicrobial agents using agar dilution method. Antibacterial susceptibility of the total 33 isolates and the distribution of ESBLs producers of the resistant isolates were analyzed based on the break- points of the CLSI MIO0-S20. ESBLs producers were screened by ESBLs initial screening test and confirmed by CLSI phenotype confirma- tory test. Results The resistance rates of Proteus mirabilis to Piperacillin, Cefuroxime, Ceflazidime, Cefotaxime, Cefepime and Aztrean- am were 12. 1% , 30. 3% , 24.2% , 27.3%, 18.2% and 21.2%, respectively. The resistance rate to Cefazolin was the highest （ 100% ）. Compared to other drugs, the resistance rates to Gatifloxacin （45.5%）, Ciprofloxacin（39.4% ） and Levofloxacin （39.4%） were higher. The detection rate of ESBLs producers was 18.2% （6/33）. Except for Imipenem, Cefazolin and Piperacillin, the resistance rates of ESBLs producers were significant higher than non-ESBLs producers （ P 〈0. 01 ）. Conclusion Clinically isolated P. mirabilis show different extent of resistance to antimicrobial agents. The incidence of ESBLs producers is high in P. mirabilis isolates. ESBLs pro- ducers are multi-resistant. Compared with the resistance rates of non-ESBLs producing strains, ESBLs producers are more resistant, while all strains are sensitive to imipenem and resistant to Cefazolin.