Health and Development Post-graduation Program, Central-West Region, Universidade Federal de Mato Grosso do Sul, MS, Brazil.
Braz J Infect Dis. 2011 May-Jun;15(3):195-9. doi: 10.1016/s1413-8670(11)70174-x.
Infection by Pseudomonas aeruginosa has spread worldwide, with limited options for treatment. The purpose of this study was to investigate metallo-β-lactamase-producing P. aeruginosa strains and compare their genetic profile using samples collected from patients in intensive care units. Forty P. aeruginosa strains were isolated from two public hospitals in Campo Grande, Mato Grosso do Sul State, from January 1st, 2007 to June 31st, 2008. Profiles of antimicrobial susceptibility were determined using the agar diffusion method. Metallo-β-lactamase was investigated using the double-disk diffusion test and PCR. Molecular typing was performed by pulsed-field gel electrophoresis (PFGE). Respiratory and urinary tracts were the most common isolation sites. Of the 40 samples tested, 72.5% (29/40) were resistant to ceftazidime and 92.5% (37/40) to imipenem, whereas 65% (26/40) were resistant to both antimicrobials. Fifteen pan-resistant samples were found. Five percent (2/40) of samples were positive for metallo-β-lactamase on the phenotype test. No metallo-β-lactamase subtype was detected by PCR. Macrorestriction analysis revealed 14 distinct genetic patterns. Based on the superior accuracy of PCR, it can be inferred that P. aeruginosa isolates from the investigated hospitals have alternative mechanisms of carbapenem resistance. The results also suggest clonal spread of P. aeruginosa between the studied hospitals.
铜绿假单胞菌的感染已在全球范围内传播，治疗选择有限。本研究的目的是调查产金属β-内酰胺酶的铜绿假单胞菌菌株，并使用从重症监护病房患者中收集的样本比较它们的遗传谱。从 2007 年 1 月 1 日至 2008 年 6 月 31 日，从南马托格罗索州坎波格兰德的两家公立医院中分离出 40 株铜绿假单胞菌。使用琼脂扩散法测定抗菌药物敏感性谱。使用双碟扩散试验和 PCR 检测金属β-内酰胺酶。通过脉冲场凝胶电泳（PFGE）进行分子分型。呼吸道和泌尿道是最常见的分离部位。在 40 个测试样本中，72.5%（29/40）对头孢他啶耐药，92.5%（37/40）对亚胺培南耐药，而 65%（26/40）对两种抗菌药物均耐药。发现 15 个泛耐药样本。表型试验中，有 5%（2/40）的样本对金属β-内酰胺酶呈阳性。PCR 未检测到金属β-内酰胺酶亚型。宏观限制分析显示有 14 种不同的遗传模式。基于 PCR 的更高准确性，可以推断出所研究医院的铜绿假单胞菌分离株具有替代碳青霉烯类药物耐药的机制。结果还表明，所研究医院之间的铜绿假单胞菌存在克隆传播。
