Temporal changes in the microbiological resistance profile have been reported in several life-threatening infections. However, no data have ever assessed this issue in postoperative peritonitis (POP). Our purpose was to assess the rate of multidrug-resistant organisms (MDROs) in POP over a two-decade period and to analyse their influence on the adequacy of empirical antibiotic therapy (EAT). This retrospective monocentric analysis (1999–2019) addressed the changes over time in microbiologic data, including the emergence of MDROs and the adequacy of EAT for all intensive care unit adult patients treated for POP. The in vitro activities of 10 antibiotics were assessed to determine the most adequate EAT in the largest number of cases among 17 antibiotic regimens in patients with/without MDRO isolates. Our primary endpoint was to determine the frequency of MDRO and their temporal changes. Our second endpoint assessed the impact of MDROs on the adequacy of EAT per patient and their temporal changes based on susceptibility testing. In this analysis, the subgroup of patients with MDRO was compared with the subgroup of patients free of MDRO. A total of 1,318 microorganisms were cultured from 422 patients, including 188 (45%) patients harbouring MDROs. The growing proportions of MDR Enterobacterales were observed over time (p = 0.016), including ESBL-producing strains (p = 0.0013), mainly related to Klebsiella spp (p < 0.001). Adequacy of EAT was achieved in 305 (73%) patients. Decreased adequacy rates were observed when MDROs were cultured [p = 0.0001 vs. MDRO-free patients]. Over the study period, decreased adequacy rates were reported for patients receiving piperacillin/tazobactam in monotherapy or combined with vancomycin and imipenem/cilastatin combined with vancomycin (p < 0.01 in the three cases). In patients with MDROs, the combination of imipenem/cilastatin + vancomycin + amikacin or ciprofloxacin reached the highest adequacy rates (95% and 91%, respectively) and remained unchanged over time. We observed high proportions of MDRO in patients treated for POP associated with increasing proportions of MDR Enterobacterales over time. High adequacy rates were only achieved in antibiotic combinations involving carbapenems and vancomycin, while piperacillin/tazobactam is no longer a drug of choice for EAT in POP in infections involving MDRO.

中文翻译：

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术后腹膜炎治疗患者的微生物学特征：1999-2019 年时间趋势

据报道，在几种危及生命的感染中，微生物耐药性随时间发生变化。然而，没有数据评估术后腹膜炎（POP）中的这个问题。我们的目的是评估二十年来 POP 中多重耐药菌 (MDRO) 的比率，并分析它们对经验性抗生素治疗 (EAT) 充分性的影响。这项回顾性单中心分析（1999-2019）探讨了微生物学数据随时间的变化，包括 MDRO 的出现以及所有接受 POP 治疗的重症监护病房成年患者 EAT 的充分性。对 10 种抗生素的体外活性进行了评估，以确定在 17 种抗生素治疗方案中，在患有/不患有 MDRO 分离株的患者中，在最多病例中最适当的 EAT。我们的主要终点是确定 MDRO 的频率及其时间变化。我们的第二个终点评估了 MDRO 对每位患者 EAT 充足性的影响及其基于药敏试验的时间变化。在此分析中，将患有多重耐药菌的患者亚组与无多重耐药菌的患者亚组进行了比较。从 422 名患者体内培养出总共 1,318 种微生物，其中 188 名患者（45%）携带 MDRO。随着时间的推移，观察到耐多药肠杆菌的比例不断增加 (p = 0.016)，包括产 ESBL 菌株 (p = 0.0013)，主要与克雷伯菌属相关 (p < 0.001)。 305 名 (73%) 患者获得了充分的 EAT。当培养 MDRO 时，观察到充分率降低 [与无 MDRO 的患者相比，p = 0.0001]。在研究期间，接受哌拉西林/他唑巴坦单药治疗或与万古霉素联合治疗以及亚胺培南/西司他丁与万古霉素联合治疗的患者的充分率下降（三例中p＜＜0.01）。在MDRO患者中，亚胺培南/西司他丁+万古霉素+阿米卡星或环丙沙星联合用药达到了最高的充分率（分别为95%和91%），并且随着时间的推移保持不变。我们观察到，在接受 POP 治疗的患者中，MDRO 的比例很高，并且随着时间的推移，MDR 肠杆菌的比例也随之增加。仅在涉及碳青霉烯类和万古霉素的抗生素组合中才能实现高充足率，而哌拉西林/他唑巴坦不再是涉及多重耐药菌感染的 POP 中 EAT 的首选药物。