Nogueira Keite da Silva, Paganini Maria Cristina, Conte Andréia, Cogo Laura Lúcia, Taborda de Messias Reason Iara, da Silva Márcio José, Dalla-Costa Libera Maria
Clinics Hospital, Federal University of Paraná (UFPR), Curitiba, Brazil; Postgraduate Program in Pharmaceutical Sciences of UFPR, Curitiba, Brazil.
Clinics Hospital, Federal University of Paraná (UFPR), Curitiba, Brazil.
Enferm Infecc Microbiol Clin. 2014 Feb;32(2):87-92. doi: 10.1016/j.eimc.2013.02.004. Epub 2013 Apr 12.
Extended-spectrum β-lactamases (ESBLs) are increasingly prevalent in Enterobacter spp., posing a challenge to the treatment of infections caused by this microorganism. The purpose of this retrospective study was to evaluate the prevalence, risk factors, and clinical outcomes of inpatients with bacteremia caused by ESBL and non ESBL-producing Enterobacter spp. in a tertiary hospital over the period 2004-2008.
The presence of blaCTX-M, blaTEM, blaSHV, and blaPER genes was detected by polymerase chain reaction (PCR) and nucleotide sequence analysis. Genetic similarity between strains was defined by pulsed-field gel electrophoresis (PFGE).
Enterobacter spp. was identified in 205 of 4907 of the patients who had positive blood cultures during hospitalization. Of those cases, 41 (20%) were ESBL-producing Enterobacter spp. Nosocomial pneumonia was the main source of bacteremia caused by ESBL-producing Enterobacter spp. The presence of this microorganism was associated with longer hospital stays. The ESBL genes detected were: CTX-M-2 (23), CTX-M-59 (10), CTX-M-15 (1), SHV-12 (5), and PER-2 (2). While Enterobacter aerogenes strains showed mainly a clonal profile, Enterobacter cloacae strains were polyclonal.
Although no difference in clinical outcomes was observed between patients with infections by ESBL-producing and non-ESBL-producing strains, the detection of ESBL in Enterobacter spp. resulted in the change of antimicrobials in 75% of cases, having important implications in the decision-making regarding adequate antimicrobial therapy.
超广谱β-内酰胺酶（ESBLs）在肠杆菌属中日益普遍，这对该微生物引起的感染治疗构成挑战。这项回顾性研究的目的是评估2004年至2008年期间一家三级医院中由产ESBL和不产ESBL的肠杆菌属引起菌血症的住院患者的患病率、危险因素和临床结局。
通过聚合酶链反应（PCR）和核苷酸序列分析检测blaCTX-M、blaTEM、blaSHV和blaPER基因的存在。菌株之间的遗传相似性通过脉冲场凝胶电泳（PFGE）确定。
在4907例住院期间血培养阳性的患者中，有205例鉴定出肠杆菌属。在这些病例中，41例（20%）为产ESBL的肠杆菌属。医院获得性肺炎是产ESBL的肠杆菌属引起菌血症的主要来源。这种微生物的存在与住院时间延长有关。检测到的ESBL基因有：CTX-M-2（23例）、CTX-M-59（10例）、CTX-M-15（1例）、SHV-12（5例）和PER-2（2例）。产气肠杆菌菌株主要表现为克隆型，阴沟肠杆菌菌株为多克隆型。
虽然产ESBL菌株感染患者与不产ESBL菌株感染患者的临床结局未观察到差异，但在肠杆菌属中检测到ESBL导致75%的病例抗菌药物发生改变，这对适当抗菌治疗的决策具有重要意义。
