{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,28]],"date-time":"2026-10-28T14:52:56Z","timestamp":1793199176195,"version":"4.5.0"},"reference-count":39,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2025,6,28]],"date-time":"2025-06-28T00:00:00Z","timestamp":1751068800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Microorganisms"],"abstract":"<jats:p>Antimicrobial susceptibility testing (AST) is not routinely performed for C. difficile infection (CDI); however, reports of antimicrobial resistance to various antibiotics have increased. This study aimed to assess the rate of antimicrobial resistance to four antimicrobials (vancomycin, metronidazole, tigecycline, and ciprofloxacin) to assess risk factors for antimicrobial resistance and evaluate MIC variation in patients with recurrence. Data from consecutive patients with CDI admitted to our institution between 1 January 2022 and 30 April 2023 were collected. We performed AST with gradient diffusion and NAAT to evaluate the presumptive presence of R027\/NAP1 and toxin production genes. Antimicrobial susceptibility testing was performed on 108 available isolates. We did not find any resistance to vancomycin (median MIC 0.5 \u03bcg\/mL), metronidazole (median MIC 1 \u03bcg\/mL), and tigecycline (median MIC 0.016 \u03bcg\/mL), while resistance to ciprofloxacin was detected in all the samples. Among the recurrent isolates, 37.5% displayed a 2-fold MIC increase for vancomycin, 75% for metronidazole, and 37.5% for tigecycline. After stratifying clinical outcomes according to vancomycin MIC, patients with higher MIC experienced increased 28-day mortality (p value 0.009). Our results were concordant with European surveillance data. MIC increase in all tested antibiotics in patients with CDI warrants further research since decreased susceptibility has been associated with clinical failure.<\/jats:p>","DOI":"10.3390\/microorganisms13071515","type":"journal-article","created":{"date-parts":[[2025,6,30]],"date-time":"2025-06-30T03:54:28Z","timestamp":1751255668000},"page":"1515","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Minimum Inhibitory Concentration Increase in Clostridioides difficile Isolates from Patients with Recurrence: Results from a Retrospective Single-Centre Cohort Study"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3425-9817","authenticated-orcid":false,"given":"Pietro","family":"Valsecchi","sequence":"first","affiliation":[{"name":"Infectious Diseases I Unit, IRCCS Policlinico San Matteo Foundation, 27100 Pavia, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1618-8867","authenticated-orcid":false,"given":"Erika","family":"Asperges","sequence":"additional","affiliation":[{"name":"Infectious Diseases I Unit, IRCCS Policlinico San Matteo Foundation, 27100 Pavia, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0969-6484","authenticated-orcid":false,"given":"Marta","family":"Corbella","sequence":"additional","affiliation":[{"name":"Clinical Microbiology and Virology Unit, IRCCS Policlinico San Matteo Foundation, 27100 Pavia, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0007-3900-8850","authenticated-orcid":false,"given":"Greta","family":"Banfi","sequence":"additional","affiliation":[{"name":"Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, 27100 Pavia, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marcello","family":"Maffezzoni","sequence":"additional","affiliation":[{"name":"Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, 27100 Pavia, Italy"},{"name":"Infectious and Tropical Diseases Unit, Department of Medicine and Surgery, University of Insubria-ASST-Sette Laghi, 21100 Varese, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nicol\u00f2","family":"Amarasinghe","sequence":"additional","affiliation":[{"name":"Infectious Diseases I Unit, IRCCS Policlinico San Matteo Foundation, 27100 Pavia, Italy"},{"name":"Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, 27100 Pavia, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Riccardo","family":"Drago","sequence":"additional","affiliation":[{"name":"Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, 27100 Pavia, Italy"},{"name":"Internal Medicine Unit, IRCCS Policlinico San Matteo Foundation, 27100 Pavia, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Flavia","family":"Virga","sequence":"additional","affiliation":[{"name":"Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, 27100 Pavia, Italy"},{"name":"Internal Medicine Unit, IRCCS Policlinico San Matteo Foundation, 27100 Pavia, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Filippo","family":"Costanzo","sequence":"additional","affiliation":[{"name":"SSD Stewardship Antibiotica, ASST, 27100 Pavia, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Francesca","family":"Calabretta","sequence":"additional","affiliation":[{"name":"Internal Medicine Unit, IRCCS Policlinico San Matteo Foundation, 27100 Pavia, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Paolo","family":"Sacchi","sequence":"additional","affiliation":[{"name":"Infectious Diseases I Unit, IRCCS Policlinico San Matteo Foundation, 27100 Pavia, Italy"},{"name":"Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, 27100 Pavia, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Patrizia","family":"Cambieri","sequence":"additional","affiliation":[{"name":"Clinical Microbiology and Virology Unit, IRCCS Policlinico San Matteo Foundation, 27100 Pavia, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0302-8645","authenticated-orcid":false,"given":"Antonio","family":"Di Sabatino","sequence":"additional","affiliation":[{"name":"Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, 27100 Pavia, Italy"},{"name":"Internal Medicine Unit, IRCCS Policlinico San Matteo Foundation, 27100 Pavia, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fausto","family":"Baldanti","sequence":"additional","affiliation":[{"name":"Clinical Microbiology and Virology Unit, IRCCS Policlinico San Matteo Foundation, 27100 Pavia, Italy"},{"name":"Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, 27100 Pavia, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0235-9207","authenticated-orcid":false,"given":"Raffaele","family":"Bruno","sequence":"additional","affiliation":[{"name":"Infectious Diseases I Unit, IRCCS Policlinico San Matteo Foundation, 27100 Pavia, Italy"},{"name":"Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, 27100 Pavia, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,6,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1016\/j.anaerobe.2016.06.008","article-title":"Reclassification of Clostridium difficile as Clostridioides difficile (Hall and O\u2019Toole 1935) Pr\u00e9vot 1938","volume":"40","author":"Lawson","year":"2016","journal-title":"Anaerobe"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"285","DOI":"10.1038\/s41579-021-00660-2","article-title":"Clostridioides difficile Toxins: Mechanisms of Action and Antitoxin Therapeutics","volume":"20","author":"Kordus","year":"2022","journal-title":"Nat. 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