BACKGROUND Increased occurrence of a particular species of Gram-negative bacteria (GNB), especially when multi-drug-resistant (MDR), in routine screening surveillance in neonatal intensive care units (NICUs) can be evoked by selection pressure. AIM To evaluate adaptation of the empiric antibiotic regimen for its usefulness as a control measure in suspected outbreaks in the NICU. METHODS In a retrospective outbreak analysis, cases between 1st December 2017 and 31st March 2018 were identified through microbiology and hygiene surveillance records. Furthermore, risk factors for MDR-GNB colonization were collected. Whole-genome sequencing (WGS) was performed on all isolates. Control measure documentations and interviews were employed to define interventions. As well as infection control measures, administration of third-generation cephalosporins was avoided and replaced whenever clinically acceptable as part of the intervention bundle. FINDINGS In total, nine patients were found to have rectal colonization with third-generation cephalosporin-resistant Enterobacter cloacae in routine screening surveillance in the pre-intervention period. After implementation of an infection control bundle, the incidence declined rapidly. WGS analysis revealed that two MDR E. cloacae were transmitted, and the majority were new cases. The incidence density of MDR-GNB colonization was 7.94/1000 patient-days (PD) before the intervention and 1.68/1000 PD during the altered antibiotic regimen. No infections with MDR-GNB occurred during the study. CONCLUSIONS Altering the antibiotic regimen with regard to selection pressure may be considered as part of an intervention bundle to rapidly control the emergence of MDR-GNB in suspected outbreak situations in the NICU.

中文翻译：

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在新生儿重症监护病房怀疑多药耐药的阴沟肠杆菌暴发中，抗生素治疗方案的改变是一项附加的控制措施。

背景技术在新生儿重症监护病房（NICUs）的常规筛查监测中，特别是革兰氏阴性菌（GNB）的特别是当多重耐药性（MDR）发生时，可能会因选择压力而引起。目的评估经验性抗生素方案的适应性，以作为NICU疑似疾病暴发中的控制措施。方法在回顾性爆发分析中，通过微生物学和卫生监测记录确定了2017年12月1日至2018年3月31日之间的病例。此外，收集了MDR-GNB定植的危险因素。对所有分离株进行全基因组测序（WGS）。使用控制措施文档和访谈来定义干预措施。以及控制感染的措施，避免使用第三代头孢菌素，并在临床上可接受时作为干预措施的一部分予以更换。结果在干预前的常规筛查监测中，总共发现9例患有第三代头孢菌素耐药性阴沟肠杆菌的直肠定植。实施感染控制包后，发病率迅速下降。WGS分析显示，已传播了两个MDR阴沟肠杆菌，其中大多数是新病例。干预前，MDR-GNB定植的发生密度为7.94 / 1000患者-天（PD），而改变抗生素治疗方案期间，其发生密度为1.68 / 1000 PD。在研究期间未发生MDR-GNB感染。