Objective: The aim of the study was to compare the rate of gram-negative multi-drug resistant organism (GN-MDRO) colonization at admission and during hospitalization and to describe the strains and antibiotic resistance genes acquired during hospitalization.
Methods: Rectal swabs were collected from patients hospitalized at the National Trauma Center (NTC), Mongolia, at the time of admission and after 14 days of hospitalization as has been detailed on our previous study. GN-MDRO antibiotic resistance was determined using EUCAST standards, and resistance genes were detected using multiplex PCR.
Results: A total of 158 patients were screened, and baseline colonization rate at admission was 29.1% (46/158). The rate went up to 69.9% (110/158) after 14 days of hospitalization (p< 0.001). Of all participants, 74 patients (46.8%) screened GN-MDRO negative at admission acquired colonization by day 14. Other 36 patients (22.8%) maintained colonization that was screened positive at both time points. Only 38 patients (24.0%) remained free of GN-MDRO during hospitalization. There was a difference in GN-MDRO acquisition between these groups. Patients who were negative at admission acquired up to 3 GN-MDRO species, and there were 10 different species isolated. Reversely, patients who were screened positive at both time points had fairly homogenous isolates; up to 5 species of Enterobacterales were identified at admission and day 14 hospitalization. Overall, Enterobacterales were the dominant colonizers (61.4%, 97/158), and all Enterobacterales were resistant to cefotaxime as CTX-M resistance was our inclusion criteria.
Conclusion: GN-MDRO baseline colonization rate on admission was high and, alarmingly, doubled during hospitalization in the study area. Enterobacterales was the predominant colonizer and was highly resistant to 3rd generation cephalosporin. This data supports a need for an improved infection control policy including routine surveillance of the GN-MDROs and improved antibiotic stewardship program.

Keywords: multi-drug resistant organism, colonization, antibiotic resistance, hospital


中文翻译：

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住院期间革兰氏阴性多药耐药生物定植的高获得率：从高流行环境的角度来看

目的：本研究的目的是比较入院和住院期间的革兰氏阴性多重耐药菌 (GN-MDRO) 定植率，并描述住院期间获得的菌株和抗生素耐药基因。
方法：从入院时和住院 14 天后在蒙古国家创伤中心 (NTC) 住院的患者中收集直肠拭子，如我们之前的研究中所述。使用 EUCAST 标准确定 GN-MDRO 抗生素耐药性，使用多重 PCR 检测耐药基因。
结果：共筛查了 158 名患者，入院时的基线定植率为 29.1% (46/158)。住院 14 天后，该比率上升到 69.9% (110/158) (p<0.001)。在所有参与者中，74 名患者 (46.8%) 入院时 GN-MDRO 筛查为阴性，到第 14 天获得定植。其他 36 名患者 (22.8%) 保持定植，在两个时间点均呈阳性。只有 38 名患者（24.0%）在住院期间没有使用 GN-MDRO。这些组之间的 GN-MDRO 采集存在差异。入院时为阴性的患者获得了多达 3 种 GN-MDRO 物种，并且分离了 10 种不同的物种。相反，在两个时间点都筛查出阳性的患者具有相当同质的分离物；在入院和第 14 天住院时鉴定出多达 5 种肠杆菌。
结论：入院时 GN-MDRO 基线定植率很高，而且令人震惊的是，在研究区住院期间，该定植率翻了一番。肠杆菌是主要的定殖菌，对第三代头孢菌素具有高度耐药性。该数据支持改进感染控制政策的需要，包括对 GN-MDRO 的常规监测和改进的抗生素管理计划。

关键词：多重耐药菌，定植，抗生素耐药性，医院