Introduction. While colonization by Staphylococcus aureus in haemodialysis patients has been assessed, knowledge about colonization by beta-lactam-resistant Gram-negative bacilli is still limited. Aim. To describe clinical and molecular characteristics in haemodialysis patients colonized by S. aureus (MSSA-MRSA) and beta-lactam-resistant Gram-negative bacilli in an ambulatory renal unit. Methodology. The study included patients with central venous catheters in an outpatient haemodialysis facility in Medellín, Colombia (October 2017–October 2018). Swab specimens were collected from the nostrils and skin around vascular access to assess colonization by S. aureus (MSSA-MRSA). Stool samples were collected from each patient to evaluate beta-lactam-resistant Gram-negative bacilli colonization. Molecular typing included PFGE, multilocus sequence typing (MLST), spa typing and enterobacterial repetitive intergenic consensus-PCR (ERIC). Clinical information was obtained from medical records and personal interview. Results. A total of 210 patients were included in the study. S. aureus colonization was observed in 33.8 % (n=71) of the patients, 4.8 % (n=10) of which were colonized by methicillin-resistant S. aureus . Stool samples were collected from 165 patients and of these 41.2 % (n=68) and 11.5 % (n=19) were colonized by extended-spectrum-beta-lactamase-producing (ESBL) and carbapenem-resistant bacilli, respectively. Typing methods revealed high genetic diversity among S. aureus and ESBL-producing Gram-negative bacilli (ESBL-GNB). Antibiotic use and hospitalization in the previous 6 months were observed in more than half of the studied population. Conclusion. The high colonization by ESBL-GNB in haemodialysis patients shows evidence for the need for stronger surveillance, not only for S. aureus but also for multidrug-resistant bacilli in order to avoid their spread. Additionally, the high genetic diversity suggests other sources of transmission outside the renal unit instead of horizontal transmission between patients.

中文翻译：

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血液透析中不同的对β-内酰胺耐药的革兰氏阴性杆菌克隆的定殖频率高：肾单位外的不同传播来源？

介绍。虽然已经评估了血液透析患者中金黄色葡萄球菌的定殖，但是关于β-内酰胺耐药的革兰氏阴性菌定殖的知识仍然有限。目标。为了描述在门诊肾脏病单位中被金黄色葡萄球菌（MSSA-MRSA）和β-内酰胺耐药的革兰氏阴性菌定植的血液透析患者的临床和分子特征。方法。该研究包括哥伦比亚麦德林的一家门诊血液透析设施中的中心静脉导管患者（2017年10月至2018年10月）。从鼻孔和血管通路周围的皮肤中收集拭子标本，以评估金黄色葡萄球菌的定植 （MSSA-MRSA）。从每位患者收集粪便样品，以评估抗β-内酰胺的革兰氏阴性杆菌定殖。分子分型包括PFGE，多基因座序列分型（MLST），spa分型和肠细菌重复性基因间共有PCR（ERIC）。临床信息来自病历和个人访谈。结果。该研究共包括210名患者。在33.8％（n = 71）的患者中观察到金黄色葡萄球菌定植，其中有4.8％（n = 10）由耐甲氧西林的金黄色葡萄球菌定植。从165名患者中收集粪便样本，其中41.2％（n = 68）和11.5％（n = 19）分别通过产生超广谱β-内酰胺酶（ESBL）和抗碳青霉烯的细菌定殖。分型方法揭示了金黄色葡萄球菌和产ESBL的革兰氏阴性杆菌（ESBL-GNB）之间的高度遗传多样性。在过去的六个月中，超过一半的研究人群观察到抗生素的使用和住院治疗。结论。ESBL-GNB在血液透析患者中​​的高度定殖表明，有必要加强监测，不仅是金黄色葡萄球菌，而且还有耐多药细菌以避免扩散的证据。此外，高遗传多样性提示在肾单位外还有其他传播途径，而不是患者之间的水平传播。