尿路感染患者大肠埃希菌和克雷伯菌分离株中β-内酰胺酶的频率评估
Frequency assessment of β-lactamase enzymes in Escherichia coli and Klebsiella isolates in patients with urinary tract infection.
作者信息
Moayednia Reza, Shokri Dariush, Mobasherizadeh Sina, Baradaran Azar, Fatemi Seyed Masih, Merrikhi Alireza
机构信息
Department of Pathology, Al-Zahra Hospital, Isfahan University of Medical Sciences, Isfahan, Iran.
Infectious Diseases and Tropical Medicine Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
出版信息
J Res Med Sci. 2014 Mar;19(Suppl 1):S41-5.
BACKGROUND
Production of β-lactamase enzymes is the most common and important mechanism of resistance in Gram-negative bacteria. The objective of this study was to assess frequency of three main β-lactamase enzymes, including extended spectrum β-lactamases (ESBLs), metallo-β-lactamase (MBL), and Klebsiella pneumoniae carbapenemase (KPC) enzymes in Escherichia coli and Klebsiella spp. isolated from nosocomial and community urinary tract infections (UTI).
MATERIALS AND METHODS
In a cross-sectional study from March to December 2012, midstream urine samples were obtained from patients suspicious of UTI who were hospitalized or referred to Al-Zahra Hospital, Isfahan, Iran. Samples were cultured and E. coli and Klebsiella spp. were isolated. Prevalence of ESBLs, KPC, and MBLs producing E. coli and Klebsiella spp. were studied by double-disk (combined-disk), the modified Hodge test and imipenem-ethylenediaminetetraacetic acid combined disc methods respectively. In addition, their antimicrobial susceptibility patterns determined and resistant to carbapenem drugs confirmed by minimum inhibitory concentrations based on E-test method.
RESULTS
A total of 1080 E. coli and 484 Klebsiella strains were isolated during study period. Among 720 E. coli and 384 Klebsiella isolates from hospitalized patients, 300 (41.7%) and 198 (51.5%) were ESBLs producers, respectively. In out-patients samples, the rate of ESBLs production was 25% (90/360) and 40% (40/100) in E. coli and Klebsiella isolates, respectively. Prevalence of MBLs producing in hospital E. coli and Klebsiella isolates were 0.3% (2/720) and 2.6% (10/384), and for KPC data were 1.4% (10/720) and 48.4% (186/384), respectively. No MBLs and KPC producing isolate was seen in non-hospital E. coli and Klebsiella isolates except for one non-hospital KPC producing Klebsiella isolate.
CONCLUSION
The result of our study showed high prevalence of ESBLs and KPC, but low prevalence of MBLs in cultured bacteria from urine samples of patients with acute UTI. In addition, KPC was the main carbapenem resistance mechanism in Klebsiella and E. coli isolates.
背景
β-内酰胺酶的产生是革兰氏阴性菌耐药最常见且最重要的机制。本研究的目的是评估从医院获得性和社区性尿路感染（UTI）分离出的大肠杆菌和克雷伯菌属中三种主要β-内酰胺酶的频率，包括超广谱β-内酰胺酶（ESBLs）、金属β-内酰胺酶（MBL）和肺炎克雷伯菌碳青霉烯酶（KPC）。
材料与方法
在一项2012年3月至12月的横断面研究中，从怀疑患有UTI的住院患者或转诊至伊朗伊斯法罕的阿尔-扎赫拉医院的患者中获取中段尿样本。对样本进行培养并分离出大肠杆菌和克雷伯菌属。分别通过双纸片（联合纸片）、改良Hodge试验和亚胺培南-乙二胺四乙酸联合纸片法研究产ESBLs、KPC和MBLs的大肠杆菌和克雷伯菌属的患病率。此外，根据E-test法通过最低抑菌浓度确定它们的抗菌药敏模式并确认对碳青霉烯类药物的耐药性。
结果
在研究期间共分离出1080株大肠杆菌和484株克雷伯菌。在从住院患者中分离出的720株大肠杆菌和384株克雷伯菌中，分别有300株（41.7%）和198株（51.5%）产ESBLs。在门诊患者样本中，大肠杆菌和克雷伯菌分离株中产ESBLs的比例分别为25%（90/360）和40%（40/100）。医院分离的大肠杆菌和克雷伯菌中产MBLs的患病率分别为0.3%（2/720）和2.6%（10/384），产KPC的数据分别为1.4%（10/720）和48.4%（186/384）。在非医院分离的大肠杆菌和克雷伯菌中，除了一株非医院分离的产KPC的克雷伯菌外，未发现产MBLs和KPC的分离株。
结论
我们的研究结果显示，急性UTI患者尿样本培养出的细菌中ESBLs和KPC的患病率较高，但MBLs的患病率较低。此外，KPC是克雷伯菌和大肠杆菌分离株中主要的碳青霉烯耐药机制。
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