{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,3]],"date-time":"2026-06-03T07:20:35Z","timestamp":1780471235969,"version":"3.54.1"},"reference-count":25,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2026,5,22]],"date-time":"2026-05-22T00:00:00Z","timestamp":1779408000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Antibiotics"],"abstract":"<jats:p>Background\/Objectives: Patients in long-term care hospitals (LTCHs) are at increased risk of harboring antimicrobial-resistant organisms due to frequent healthcare exposure and multiple comorbidities. This retrospective observational study aimed to compare the antimicrobial susceptibility of bacterial isolates from LTCH-onset infections (LTCHIs) with those from community-acquired infections (CAIs) in elderly patients. Methods: This study was conducted at a 700-bed urban tertiary university hospital and included patients aged \u226565 years with positive cultures for bacteremia, lower respiratory tract infections (LRTIs), or urinary tract infections (UTIs) within 48 h of admission. Medical records, including antimicrobial susceptibility test results, were reviewed for a total of 1780 patients and their isolates. Antimicrobial susceptibility patterns were compared between LTCHI and CAI patients. Results: Patients with LTCHI exhibited significantly higher antimicrobial non-susceptibility than those with CAIs across multiple pathogens and antimicrobial classes (p &lt; 0.05). In bacteremia, Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae from LTCHI cases showed increased non-susceptibility to \u03b2-lactams and fluoroquinolones. In LRTIs, Pseudomonas aeruginosa and Acinetobacter baumannii demonstrated high non-susceptibility to carbapenems (52.9% and 90%, respectively) and aminoglycosides. In UTIs, LTCHI isolates exhibited broader resistance among Enterobacterales and P. aeruginosa. Notably, the proportion of multidrug-resistant organisms, including carbapenem-resistant Enterobacterales (15.4\u201350.0%) and carbapenem-resistant Acinetobacter baumannii (90.5%), was substantially higher in the LTCHI group across all infection sites. Conclusions: Elderly patients with LTCHI are more likely to harbor antimicrobial-resistant pathogens than those with CAIs. Careful consideration of LTCHI origin is therefore essential for empirical antibiotic selection and for strategies aimed at limiting further resistance.<\/jats:p>","DOI":"10.3390\/antibiotics15060530","type":"journal-article","created":{"date-parts":[[2026,5,22]],"date-time":"2026-05-22T13:12:08Z","timestamp":1779455528000},"page":"530","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Comparison of Antimicrobial Susceptibility Patterns of Bacterial Isolates from Blood, Urine, and Lower Respiratory Tract Specimens Between Elderly Patients in Long-Term Care Hospitals and Community-Acquired Infections: A Retrospective Study"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8472-9573","authenticated-orcid":false,"given":"Kye Won","family":"Choe","sequence":"first","affiliation":[{"name":"Department of Laboratory Medicine, Chung-Ang University Gwangmyeong Hospital, Chung-Ang University College of Medicine, 110, Deokan-Ro, Gwangmyeong-Si 14353, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7529-1613","authenticated-orcid":false,"given":"Sumi","family":"Yoon","sequence":"additional","affiliation":[{"name":"Department of Laboratory Medicine, Chung-Ang University Gwangmyeong Hospital, Chung-Ang University College of Medicine, 110, Deokan-Ro, Gwangmyeong-Si 14353, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4300-8964","authenticated-orcid":false,"given":"Yong Kwan","family":"Lim","sequence":"additional","affiliation":[{"name":"Department of Laboratory Medicine, Chung-Ang University Hospital, Chung-Ang University College of Medicine, 102, Heukseok-ro, Dongjak-gu, Seoul 06973, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hongkyung","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Laboratory Medicine, Chung-Ang University Hospital, Chung-Ang University College of Medicine, 102, Heukseok-ro, Dongjak-gu, Seoul 06973, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mi-Kyung","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Laboratory Medicine, Chung-Ang University Hospital, Chung-Ang University College of Medicine, 102, Heukseok-ro, Dongjak-gu, Seoul 06973, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4751-7384","authenticated-orcid":false,"given":"Oh Joo","family":"Kweon","sequence":"additional","affiliation":[{"name":"Department of Laboratory Medicine, Chung-Ang University Gwangmyeong Hospital, Chung-Ang University College of Medicine, 110, Deokan-Ro, Gwangmyeong-Si 14353, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,5,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Rodriguez-Villodres, A., Martin-Gandul, C., Penalva, G., Guisado-Gil, A.B., Crespo-Rivas, J.C., Pachon-Ibanez, M.E., Lepe, J.A., and Cisneros, J.M. 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