Antimicrobial Resistance Research Center, National Institute of Infectious Diseases, Tokyo, Japan.
Project Research Center for Nosocomial Infectious Diseases, Hiroshima University, Hiroshima, Japan.
Gerontology. 2023;69(3):261-272. doi: 10.1159/000525759. Epub 2022 Oct 6.
The prevalence of antimicrobial-resistant bacteria (ARB) in long-term care facilities (LTCFs) remains unclear. Furthermore, the effect of ARB colonization on the clinical outcomes of LTCF residents has not been explored.
We conducted a prospective multicenter cohort study and investigated the residents (N = 178) of six Japanese LTCFs (three Welfare Facilities for the Elderly Requiring Long-term Care and three Geriatric Health Service Facilities) for oral and rectal carriage of ARB. The clinical outcomes of the residents were evaluated based on isolating bacterial strains and subjecting them to whole-genome sequencing.
Of the 178 participants, 32 belonging to Geriatric Health Service Facilities with no information on their clinical outcome were excluded, and the remaining 146 were followed up for at most 21 months. Extended-spectrum β-lactamases (ESBL)-producing Enterobacterales and Pseudomonas aeruginosa were detected in 42.7% (n = 76) and 2.8% (n = 5) of the rectal swabs and 5.6% (n = 10) and 3.4% (n = 6) of the oral swabs, respectively. Detection of ARB in the oral and rectal cavities showed remarkable association with enteral nutrition. Further, P. aeruginosa was significantly associated with an increase in mortality of the residents, but there were not significant association between ESBL-producing Enterobacterales and mortality. Core-genome phylogeny of P. aeruginosa revealed a wide-spread distribution of the isolated strains across the phylogeny, which included a cluster of ST235 strains with substantially higher biofilm formation ability than the other isolated P. aeruginosa strains.
DISCUSSION/CONCLUSION: This study is the first to investigate the carriage of both oral and rectal ARB, genomic relatedness and determinants of antimicrobial resistance in isolated strains, and clinical outcomes of LTCF residents. Our study provides the first direct evidence for the burden of antimicrobial resistance in LTCFs.
长期护理机构（LTCF）中抗微生物药物耐药菌（ARB）的流行情况尚不清楚。此外，ARB 定植对 LTCF 居民临床结局的影响尚未得到探索。
我们进行了一项前瞻性多中心队列研究，调查了六家日本 LTCF（三家需要长期护理的老年人福利设施和三家老年保健服务设施）的 178 名居民的口腔和直肠携带 ARB 情况。根据分离的细菌株进行全基因组测序，评估居民的临床结局。
在 178 名参与者中，32 名属于没有临床结局信息的老年保健服务设施的参与者被排除在外，其余 146 名参与者最多随访 21 个月。在直肠拭子中检测到产超广谱β-内酰胺酶（ESBL）的肠杆菌科和铜绿假单胞菌分别为 42.7%（n=76）和 2.8%（n=5），口腔拭子中分别为 5.6%（n=10）和 3.4%（n=6）。口腔和直肠腔中 ARB 的检测与肠内营养有显著关联。此外，铜绿假单胞菌与居民死亡率的增加显著相关，但产 ESBL 的肠杆菌科与死亡率之间没有显著关联。铜绿假单胞菌的核心基因组系统发育分析显示，分离株在系统发育上广泛分布，包括一个 ST235 菌株聚类，其生物膜形成能力明显高于其他分离的铜绿假单胞菌菌株。
讨论/结论：本研究首次调查了 LTCF 居民口腔和直肠携带的 ARB、分离株的基因组相关性和抗微生物耐药性的决定因素以及临床结局。我们的研究为 LTCF 中的抗微生物耐药负担提供了第一个直接证据。
