Department of Systems Biology, Columbia University Irving Medical Center, 3960 Broadway, New York, NY, 10032, USA.
Department of Medicine, Columbia University Irving Medical Center, New York, USA.
Crit Care. 2020 Jul 9;24(1):404. doi: 10.1186/s13054-020-03061-8.
The need for early antibiotics in the intensive care unit (ICU) is often balanced against the goal of antibiotic stewardship. Long-course antibiotics increase the burden of antimicrobial resistance within colonizing gut bacteria, but the dynamics of this process are not fully understood. We sought to determine how short-course antibiotics affect the antimicrobial resistance phenotype and genotype of colonizing gut bacteria in the ICU by performing a prospective cohort study with assessments of resistance at ICU admission and exactly 72 h later.
Deep rectal swabs were performed on 48 adults at the time of ICU admission and exactly 72 h later, including patients who did and did not receive antibiotics. To determine resistance phenotype, rectal swabs were cultured for methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE). In addition, Gram-negative bacterial isolates were cultured against relevant antibiotics. To determine resistance genotype, quantitative PCR (qPCR) was performed from rectal swabs for 87 established resistance genes. Within-individual changes in antimicrobial resistance were calculated based on culture and qPCR results and correlated with exposure to relevant antibiotics (e.g., did β-lactam antibiotic exposure associate with a detectable change in β-lactam resistance over this 72-h period?).
Of 48 ICU patients, 41 (85%) received antibiotics. Overall, there was no increase in the antimicrobial resistance profile of colonizing gut bacteria during the 72-h study period. There was also no increase in antimicrobial resistance after stratification by receipt of antibiotics (i.e., no detectable increase in β-lactam, vancomycin, or macrolide resistance regardless of whether patients received those same antibiotics). This was true for both culture and PCR. Antimicrobial resistance pattern at ICU admission strongly predicted resistance pattern after 72 h.
Short-course ICU antibiotics made little detectable difference in the antimicrobial resistance pattern of colonizing gut bacteria over 72 h in the ICU. This provides an improved understanding of the dynamics of antimicrobial resistance in the ICU and some reassurance that short-course antibiotics may not adversely impact the stewardship goal of reducing antimicrobial resistance.
在重症监护病房（ICU）中，抗生素的早期使用往往需要与抗生素管理的目标相平衡。长期使用抗生素会增加定植于肠道细菌的抗微生物药物耐药性负担，但这一过程的动态尚未完全了解。我们通过一项前瞻性队列研究来确定短期抗生素治疗如何影响 ICU 定植肠道细菌的抗微生物药物耐药表型和基因型，在 ICU 入院时和 72 小时后分别进行了深度直肠拭子评估。
在 ICU 入院时和 72 小时后对 48 名成人进行了深度直肠拭子检测，包括接受和未接受抗生素治疗的患者。为了确定耐药表型，对直肠拭子进行了耐甲氧西林金黄色葡萄球菌（MRSA）和万古霉素耐药肠球菌（VRE）的培养。此外，对革兰氏阴性细菌分离株进行了针对相关抗生素的培养。为了确定耐药基因型，从直肠拭子中进行了 87 种已建立的耐药基因的定量 PCR（qPCR）检测。根据培养和 qPCR 结果计算了每位患者的抗生素耐药性变化，并将其与相关抗生素暴露情况相关联（例如，在这段 72 小时期间，β-内酰胺类抗生素暴露是否与β-内酰胺类耐药性的可检测变化相关联？）。
在 48 名 ICU 患者中，有 41 名（85%）接受了抗生素治疗。总体而言，在 72 小时的研究期间，定植于肠道的细菌的抗微生物药物耐药谱并没有增加。在分层接受抗生素治疗后，也没有增加抗微生物药物耐药性（即，无论患者是否接受了相同的抗生素，β-内酰胺类、万古霉素类或大环内酯类耐药性均无明显增加）。这一结果既适用于培养，也适用于 PCR。ICU 入院时的抗微生物药物耐药模式强烈预测了 72 小时后的耐药模式。
在 ICU 中，短期使用抗生素治疗在 72 小时内对定植于肠道的细菌的抗微生物药物耐药模式几乎没有明显影响。这提供了对 ICU 中抗微生物药物耐药性动态的更深入了解，并在一定程度上保证了短期使用抗生素治疗可能不会对减少抗微生物药物耐药性的管理目标产生不利影响。
