Isolation and identification of Cutibacterium acnes from skin lesions

BACKGROUND AND OBJECTIVESThe aim of this investigation was to isolate Cutibacterium acnes from comedones, deep facial cysts, and identify them by diagnostic-differential tests.MATERIALS AND METHODSSamples were collected from different areas of the skin surface of ۵۰ patients aged ۱۸ to ۶۰ years old having symptoms of acne vulgaris. Ethics consents were obtained (Ethics ID: IR.UI.REC.۱۳۹۹.۰۵۷). Samples were transferred to sterile tubes containing thioglycolate and tryptic soy broths containing ۰.۵ μg/ml of vitamin K۱ and were covered with ۱ ml of sterile mineral oil. The obtained samples were streak cultured on Brucella agar and blood agar medium . The plates were then placed in an anaerobic jar chamber in the presence of a Gas-pack type A and incubated at ۳۵-۳۷ °C for ۳-۶ days. Genomic DNA was extracted. Specific primers were used to amplify recA and MmdA genes in Cutibacterium species.RESULTS AND DISCUSSIONWhite colonies with a viscous and elastic appearance were observed, and based on Gram staining; the bacteria were in the form of gram-positive polymorphic rods, pairs or short chains. The length of the PCR fragment to identify the recA and MmdA genes was equal to ۳۳۴ and ۶۳۳ base pairs, respectively. Then, the obtained sequences were analyzed using BLAST tool in NCBI database and registered in GenBank (accession numbers: LC۵۴۲۹۳۰.۱, LC۵۴۲۹۳۲.۱, LC۵۷۱۵۸۴). In this regard, the phylogeny relationship was investigated based on the recA gene nucleotide sequence.CONCLUSIONBased on the obtained results, C. acnes (accession numbers: LC۵۴۲۹۳۰.۱ and LC۵۴۲۹۳۲.۱) were closely related to Propionibacterium granulosum, reported from France with Accession no. (AY۸۸۳۰۴۶.۱). Although both belong to the Cutibacterium genus, they belong to two different species. As a result, this issue shows various strains distributing in Iran, which can be investigated more precisely by examining more samples.

کلیدواژه ها:

Acne ، Cutibacterium acnes