{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T22:38:10Z","timestamp":1788907090123,"version":"build-2803163510"},"reference-count":34,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2025,9,19]],"date-time":"2025-09-19T00:00:00Z","timestamp":1758240000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Bulgarian Ministry of Education and Science"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Microorganisms"],"abstract":"<jats:p>Cutibacterium acnes subspecies\/phylotypes can cause infections requiring antibiotic therapy. Phylotyping of 73 (55 acneic and 18 non-acneic) C. acnes strains was performed, and antibiotic susceptibility was tested by E tests, breakpoint susceptibility test, or disk diffusion method. The dominant phylotype in both acneic and non-acneic strains was IA1 (56.2%). Phylotype II was &gt;3-fold more frequent in non-acneic than acneic isolates. Resistance in acneic strains was &gt;41% for clindamycin, 36.4% for tetracycline and 15.9% for levofloxacin, and that in non-acneic strains was &gt;38% for clindamycin, 22.2% for tetracycline and 5.6% for levofloxacin. No strain was piperacillin\/tazobactam or vancomycin resistant. Amoxicillin resistance was found in both acneic (5.4%) and non-acneic strains (11.1%), and was rare (1.8%) in phylotype I but higher (23.5%) in other strains. Double resistance was found in 32.6% of acneic and 22.2% of the non-acneic strains, and 9.3% of acneic strains displayed multidrug resistance. In conclusion, IA1 phylotype was dominant in both acneic and non-acneic strains, and type II was more frequent in non-acneic isolates. The detection (at &gt;6%) of amoxicillin resistance represents a rare yet important finding. The presence of double\/multidrug resistance strongly implies the need of susceptibility-guided therapy of the associated infections.<\/jats:p>","DOI":"10.3390\/microorganisms13092185","type":"journal-article","created":{"date-parts":[[2025,9,19]],"date-time":"2025-09-19T08:11:01Z","timestamp":1758269461000},"page":"2185","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Cutibacterium acnes Phylotyping and Antibiotic Resistance to Six Antibiotics: A Bulgarian Study"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9622-0873","authenticated-orcid":false,"given":"Lyudmila","family":"Boyanova","sequence":"first","affiliation":[{"name":"Department of Medical Microbiology, Medical University of Sofia, 1431 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0007-1028-4245","authenticated-orcid":false,"given":"Georgi","family":"Dimitrov","sequence":"additional","affiliation":[{"name":"Department of Medical Microbiology, Medical University of Sofia, 1431 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9199-9600","authenticated-orcid":false,"given":"Vessela","family":"Raykova","sequence":"additional","affiliation":[{"name":"Department of Medical Microbiology, Medical University of Sofia, 1431 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kircho","family":"Patrikov","sequence":"additional","affiliation":[{"name":"Clinic of Bone Pathology and General Orthopedics, Specialized Orthopedic University Hospital \u201cProf.B.Boychev\u201d, Gorna Banya, 1614 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3605-6447","authenticated-orcid":false,"given":"Raina","family":"Gergova","sequence":"additional","affiliation":[{"name":"Department of Medical Microbiology, Medical University of Sofia, 1431 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1634-8768","authenticated-orcid":false,"given":"Rumyana","family":"Markovska","sequence":"additional","affiliation":[{"name":"Department of Medical Microbiology, Medical University of Sofia, 1431 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,9,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"657","DOI":"10.1111\/jdv.19540","article-title":"Acne microbiome: From phyla to phylotypes","volume":"38","author":"Dreno","year":"2024","journal-title":"J. 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