这项研究的主要目的是提出多药耐药革兰氏阴性菌(GN-MDRO)的通用定义,可用于流行病学监测和基准测试。
在此回顾性数据分析中,我们使用了2017-2021年ANRESIS数据库中不同革兰氏阴性微生物的血培养分离株的解释定性易感性数据(SIR).我们首先分析了不同瑞士实验室使用的测试算法,并研究了抗生素组内的交叉耐药模式。将这些数据与现有的国际定义进行比较,我们开发了两种不同的GN-MDRO定义,用于监视目的的扩展(ANRESIS扩展)和用于临床目的的更严格的扩展,主要旨在识别难以治疗的GN-MDRO(ANRESIS限制)。使用这些新颖的算法,将我们国家数据集中确定的侵入性GN-MDRO的比率与国际和国家定义进行了比较:欧洲疾病预防和控制中心(ECDC)的定义,医院卫生和感染委员会(KRINKO)的定义和苏黎世大学医院提出的定义。
总共41,785例肠杆菌的SIR数据,2,919,和419spp。分离株用于分析。我们的MDRO定义使用了五种抗生素:氨基糖苷类,哌拉西林他唑巴坦,第三代和第四代头孢菌素,碳青霉烯类和氟喹诺酮类。在不同实验室的测试算法之间发现了很大的差异。抗生素组中的交叉抗性分析显示,最可能对特定革兰氏阴性细菌有效的物质未被优先测试(例如,阿米卡星的氨基糖苷类)。对于所有测试的细菌物种,使用ECDC-MDR定义发现多重耐药分离株的最高比率,其次是ANRESIS扩展定义。使用ANRESIS限制性定义(n=627)鉴定的MDR-肠杆菌的数量与使用KRINKO(n=622)和UHZ定义(n=437)鉴定的数量相当。然而,根据KRINKO分类为MDR-肠杆菌的分离株,UHZ和ANRESIS限制的定义(总n=870)差异很大。根据KRINKO,只有242个分离株(27.8%)被统一分类为MDRO,UHZ和ANRESIS限制定义。对克雷伯菌属的发现相当。还有铜绿假单胞菌.
不同MDRO定义的应用不仅导致MDRO率的显著差异,而且导致最终被分类为MDRO的分离株的显著差异。因此,如果在医院之间比较数据,定义全国性的MDRO算法至关重要。最小抗生素敏感性测试小组的定义将进一步提高可比性。
The main objective of this study was to propose a common definition of multidrug-resistant gram-negative organisms (GN-MDRO), which may be used for epidemiological surveillance and benchmarking.
In this retrospective data analysis, we used interpreted qualitative susceptibility data (SIR) from blood culture isolates of different gram-negative microorganisms from the ANRESIS database from 2017-2021. We first analysed testing algorithms used by different Swiss laboratories and investigated cross-resistance patterns within antibiotic groups. Comparing these data with existing international definitions, we developed two different GN-MDRO definitions, an extended one for surveillance purposes (ANRESIS-extended) and a more stringent one for clinical purposes, aimed primarily at the identification of difficult-to-treat GN-MDRO (ANRESIS-restricted). Using these novel algorithms, the rates of invasive GN-MDRO identified in our national dataset were compared with international and national definitions: the European Centre for Disease Prevention and Control (ECDC) definition, the Commission for Hospital Hygiene and Infection (KRINKO) definition and the definition proposed by the University Hospital Zurich.
SIR data of a total of 41,785 Enterobacterales, 2,919 , and 419 spp. isolates were used for the analyses. Five antibiotic categories were used for our MDRO definition: aminoglycosides, piperacillin-tazobactam, third- and fourth-generation cephalosporins, carbapenems and fluoroquinolones. Large differences were found between the testing algorithms of the different laboratories. Cross-resistance analysis within an antibiotic group revealed that the substance most likely to be effective against a particular gram-negative bacterium was not preferentially tested (e.g. amikacin for the aminoglycosides). For all bacterial species tested, the highest rates of multidrug-resistant isolates were found using the ECDC-MDR definition, followed by the ANRESIS-extended definition. The number of MDR-Enterobacterales identified using the ANRESIS-restricted definition (n = 627) was comparable to those identified using the KRINKO (n = 622) and UHZ definitions (n = 437). However, the isolates classified as MDR-Enterobacterales according to the KRINKO, UHZ and ANRESIS-restricted definitions (total n = 870) differed considerably. Only 242 of the isolates (27.8%) were uniformly classified as MDRO according to the KRINKO, UHZ and ANRESIS-restricted definitions. Comparable findings were made for Klebsiella spp. and Pseudomonas aeruginosa.
The application of different MDRO definitions leads to significant differences in not only MDRO rates but also the isolates that are eventually classified as MDRO. Therefore, defining a nationwide MDRO algorithm is crucial if data are compared between hospitals. The definition of a minimal antibiotic susceptibility testing panel would improve comparability further.