1起ICU耐碳青霉烯类 鲍曼不动杆菌感染暴发的流行病学调查

[摘要]　目的?通过对我院ICU 9例耐碳青霉烯类鲍曼不动杆菌（carbapenem-resistant Acinetobacter baumannii, CRAB）感染者进行流行病学调查,探讨CRAB感染暴发的危险因素。方法?回顾分析2019年3月17日—4月12日我院ICU收治的9例CRAB感染者的临床资料及流行病学史,应用肠杆菌科基因间重复一致序列聚合酶链式反应技术（enterobacterial repetitive intergenic consensus-polymerase chain reaction, ERIC-PCR）分析其同源性,监测ICU环境卫生学情况。结果?我院ICU A4、A6、B3及C2床患者临床样本检出的CRAB为同一疑似克隆株;B5、C1床患者样本检出的CRAB为同一疑似克隆株;B2、B2加床患者临床样本检出的CRAB为同一疑似克隆株。通过环境卫生学监测,分别从病房的空气滤网、床栏、呼吸机按钮和护士手等部位分离出50株CRAB,其中23份样本检出与患者有相同耐药谱的CRAB。ERIC-PCR结果显示,9例临床分离菌株与25例环境菌株为克隆株。手术、气管插管和前期接受抗菌药物治疗是CRAB感染的危险因素。结论?ICU患者、工作人员感控管理不到位以及空气、环境和ICU医务人员手卫生的清洁消毒措施不严格可能是此次CRAB感染传播的原因,为了减少此类医院感染事件的发生,建议加强对ICU患者与工作人员管理、加强环境及物体表面的彻底消毒、提高手卫生依从性。     

阴沟肠杆菌对碳青霉烯类药物的耐药机制

 目的 研究耐碳青霉烯类阴沟肠杆菌分子流行病学特征和碳青霉烯耐药机制,为临床经验性用药及医院感染防控提供依据。方法 对某院2019年4—9月分离的耐碳青霉烯类阴沟肠杆菌进行菌种鉴定及药敏分析,mCIM联合eCIM试验筛选碳青霉烯酶,聚合酶链反应（PCR）方法检测碳青霉烯酶耐药基因,多位点序列分型（MLST）和脉冲场凝胶电泳（PFGE）进行分子流行病学特征分析。结果 8株耐碳青霉烯类阴沟肠杆菌中5株来自于重症监护病房（ICU）,对临床常用头孢类及加酶抑制剂药物均表现出高水平耐药的特性。所有菌株均携带金属β-内酰胺酶,7株为bla_NDM-1,1株为bla_IPM-4。MLST分子分型及PFGE同源性分析有6个ST序列类型,6个克隆群。ST596（3株）均为A群、ST121（1株）为C群、ST993（1株）为F群、ST91（1株）为E群、ST794（1株）为B群、ST88（1株）为D群。结论 该院耐碳青霉烯类阴沟肠杆菌主要来源于ICU,产金属酶bla_NDM-1β-内酰胺酶是其主要耐药机制。ST596 A群阴沟肠杆菌短时间内在ICU存在局部流行,应加强医院感染防控措施,遏制暴发流行。     

老年性痴呆患者隐匿性肺炎风险预测模型的构建和验证

 目的 分析老年性痴呆患者隐匿性肺炎的危险因素并构建预测模型。方法 回顾性分析2019年1月—2020年12月安徽医科大学第三附属医院收治的明确诊断为老年性痴呆合并肺部感染患者病历资料,从确诊患者中随机挑选部分患者作为建模组,并根据是否具备隐匿性分为隐匿性肺炎组、非隐匿性肺炎组,其余病例作为验证组。分别采用单因素和logistic回归多因素分析老年痴呆患者发生隐匿性肺炎的危险因素,应用R4.0.3软件构建nomogram图并对模型进行验证。结果 共纳入216例患者。其中148例（隐匿性肺炎75例、非隐匿性肺炎73例）用于建模,68例（隐匿性肺炎37例、非隐匿性肺炎31例）用于验证。糖尿病（OR=2.565,95%CI：1.094~6.015）、重度痴呆（OR=3.079,95%CI：1.116~8.494）、痴呆病程≥10年（OR=5.782,95%CI：2.139~15.627）、年龄≥80岁（OR=2.737,95%CI：1.011~7.413）、长期卧床（OR=4.835,95%CI：1.716~13.625）为痴呆合并隐匿性肺炎的独立危险因素（均P<0.05）。通过该5项危险因素构建预测模型并进行验证,验证结果显示：建模组曲线下面积（AUC）为0.841,验证组AUC为0.756,提示该模型诊断能力良好;Hosmer-Lemeshow检验显示模型拟合优度良好;decision曲线分析显示该模型有较高的获益性。结论 年龄≥80岁、重度痴呆、痴呆病程≥10年、糖尿病、长期卧床是老年性痴呆患者发生隐匿性肺炎的独立危险因素,通过列线图模型个体化可预测老年性痴呆患者发生隐匿性肺炎的概率,从而尽早干预,改善预后。     

Carbapenem-Resistant Enterobacteriaceae in Children,United States, 1999–2012

The prevalence of carbapenem-resistant Enterobacteriaceae (CRE) infections is increasing in the United States. However, few studies have addressed their epidemiology in children. To phenotypically identify CRE isolates cultured from patients 1–17 years of age, we used antimicrobial susceptibilities of Enterobacteriaceae reported to 300 laboratories participating in The Surveillance Network–USA database during January 1999–July 2012. Of 316,253 isolates analyzed, 266 (0.08%) were identified as CRE. CRE infection rate increases were highest for Enterobacter species, blood culture isolates, and isolates from intensive care units, increasing from 0.0% in 1999–2000 to 5.2%, 4.5%, and 3.2%, respectively, in 2011–2012. CRE occurrence in children is increasing but remains low and is less common than that for extended-spectrum β-lactamase–producing Enterobacteriaceae. The molecular characterization of CRE isolates from children and clinical epidemiology of infection are essential for development of effective prevention strategies.     

Multidrug resistance mediated by co-carriage of extended-spectrum beta-lactamases,AmpC and New Delhi metallo-beta-lactamase-1 genes among carbapenem-resistant Enterobacteriaceae at five Indian medical centres

In this study, we evaluated the coexistence of extended-spectrum beta-lactamases (ESBL), AmpC and New Delhi metallo-beta-lactamase-1 (NDM-1) genes among carbapenem-resistant Enterobacteriaceae (CRE) recovered prospectively from patients at multiple sites. The study included 285 CRE strains from 2782 Gram-negative Bacilli collected from multiple centres during 2007–2010, of which 87 were characterised. Standard and reference laboratory methods were used for resistance determination. Detection of bla_NDM-1, bla_AmpC, bla_TEM, bla_SHV and bla_CTX-M was done by polymerase chain reaction. High levels of antimicrobial resistance observed among study isolates. Co-carriage of ESBLs, AmpC and NDM-1 was 26.3%. Nosocomial origin among the co-carriage isolates was 64.3%, with 9.2% associated mortality.     

碳青霉烯类耐药肠杆菌科细菌的流行病学分析、检测及临床治疗

碳青霉烯类耐药肠杆菌科细菌(Carbapenem-Resistant Enterobacteriaceae, CRE)近十年来在全球范围内迅速传播,给人类健康带来了巨大的挑战。质粒介导的碳青霉烯酶耐药基因的水平传播是引起CRE激增的主要原因,因此及时准确地检测CRE,尤其是产碳青霉烯酶的CRE,对临床治疗的指导和感染的预防控制具有十分重要的意义。目前已经研发了多种快速检测CRE的表型和基因型检测方法,且有望应用于临床微生物实验室。临床上对CRE感染的治疗方案十分有限,通常联合采用多种活性抗菌药物进行治疗,而目前活性和安全性改善的新药尚处于临床开发的后期阶段。     

Deaths Attributable to Carbapenem-Resistant Enterobacteriaceae Infections

We evaluated the number of deaths attributable to carbapenem-resistant Enterobacteriaceae by using studies from around the world published before April 9, 2012. Attributable death was defined as the difference in all-cause deaths between patients with carbapenem-resistant infections and those with carbapenem-susceptible infections. Online databases were searched, and data were qualitatively synthesized and pooled in a metaanalysis. Nine studies met inclusion criteria: 6 retrospective case–control studies, 2 retrospective cohort studies, and 1 prospective cohort study. Klebsiella pneumoniae was the causative pathogen in 8 studies; bacteremia was the only infection in 5 studies. We calculated that 26%–44% of deaths in 7 studies were attributable to carbapenem resistance, and in 2 studies, which included bacteremia and other infections, −3% and −4% of deaths were attributable to carbapenem resistance. Pooled outcomes showed that the number of deaths was significantly higher in patients with carbapenem-resistant infections and that the number of deaths attributable to carbapenem resistance is considerable.     

Combating the spread of carbapenemases in Enterobacteriaceae: a battle that infection prevention should not lose

The emergence of carbapenemases in Enterobacteriaceae has raised global concern among the scientific, medical and public health communities. Both the CDC and the WHO consider carbapenem-resistant Enterobacteriaceae (CRE) to constitute a significant threat that necessitates immediate action. In this article, we review the challenges faced by laboratory workers, infection prevention specialists and clinicians who are confronted with this emerging infection control issue.     

Molecular epidemiology and mechanisms of tigecycline resistance in carbapenem-resistant Klebsiella pneumoniae isolates

BackgroundThe emergence and transmission of tigecycline‐ and carbapenem‐resistant Klebsiella pneumoniae (TCRKP) have become a major concern to public health globally. Here, we investigated the molecular epidemiology and mechanisms of tigecycline resistance in carbapenem‐resistant K pneumoniae (CRKP) isolates.MethodsForty‐five non‐duplicate CRKP isolates were collected from January 2017 to June 2019. We performed antimicrobial susceptibility tests, multilocus sequence typing (MLST), and pulsed‐field gel electrophoresis (PFGE). PCR and DNA sequencing were performed for the detection and mutation analysis of acrR, oqxR, ramR, rpsJ, tet(A), and tet(X) genes, which are related to tigecycline resistance. The expression levels of efflux pump genes acrB and oqxB and their regulator genes rarA, ramA, soxS, and marA were assessed by quantitative real‐time PCR.ResultsThe resistance rate to tigecycline in CRKP isolates was 37.8% (17/45). K pneumoniae ST307 was a predominant clone type (70.6%, 12/17) among the TCRKP isolates. The expression levels of acrB (P < .001) and marA (P = .009) were significantly higher in the tigecycline‐resistant group than in the tigecycline‐intermediate and tigecycline‐susceptible groups. Increased expression of acrB was associated with marA expression (r = 0.59, P = .013).ConclusionsWe found that the activated MarA‐induced overexpression of AcrAB efflux pump plays an important role in the emergence of tigecycline resistance in CRKP isolates.     

苏州市某三甲医院2017年临床分离菌耐药性监测

摘要 目的 了解苏州大学附属第一医院2017年临床分离菌对临床常用抗菌药物的耐药性,为临床合理用药提供参考依据。方法 采用纸片扩散法和自动化仪器进行细菌体外药敏试验,并用Whonet 5.6软件进行统计分析。结果 2017年共分离9 106株非重复菌株,其中革兰阳性菌2 549株,占28.0%,革兰阴性菌6 557株,占72.0%。金黄色葡萄球菌(MRSA)和凝固酶阴性葡萄球菌中甲氧西林耐药株(MRCNS)的检出率分别为53.8%和71.6%。MRSA和MRCNS对绝大多数测试药物的耐药率均明显高于甲氧西林敏感株(MSSA和MSCNS)。MRSA中有94.0%菌株对甲氧苄啶-磺胺甲唑敏感;MRCNS中有76.4%的菌株对四环素敏感;未发现万古霉素耐药株。肠球菌属中粪肠球菌对多数测试抗菌药物(四环素除外)的耐药率均显著低于屎肠球菌,粪肠球菌检出1株利奈唑胺耐药株,屎肠球菌检出5株万古〖JP2〗霉素耐药株。除肺炎克雷伯菌外,多数肠杆菌科细菌对碳青霉烯类抗生素仍高度敏感,耐药率低于6%。mCIM试验显示CR-KPN 99.17%产碳青霉烯酶。结论 临床分离菌耐药率呈增长性趋势,尤其是碳青霉烯类耐药肺炎克雷伯菌,应继续加强抗菌药物应用管理,做好医院感染防控工作。〖JP〗