Department of Microbiology, Immunology and Parasitology, Institute of Basic Health Sciences, Universidade Federal Do Rio Grande Do Sul, Sarmento Leite 500, Porto Alegre, 90050-170, Brazil.
Braz J Microbiol. 2022 Mar;53(1):153-160. doi: 10.1007/s42770-021-00642-9. Epub 2021 Nov 4.
Human skin banks around the world face a serious problem with the high number of allogeneic skins that are discarded and cannot be used for grafting due to persistent bacterial contamination even after antibiotic treatment. The biofilm formation capacity of these microorganisms may contribute to the antibiotic tolerance; however, this is not yet widely discussed in the literature. Thisstudy analyzed bacterial strains isolated from allogeneic human skin samples,which were obtained from a hospital skin bank that had already been discardeddue to microbial contamination. Biofilm formation and susceptibility topenicillin, tetracycline, and gentamicin were evaluated by crystal violetbiomass quantification and determination of the minimum inhibitoryconcentration (MIC), minimum biofilm inhibitory concentration (MBIC), andminimum biofilm eradication concentration (MBEC) by the broth microdilutionmethod with resazurin dye. A total of 216 bacterial strains were evaluated, and204 (94.45%) of them were classified as biofilm formers with varying degrees ofadhesion. MBICs were at least 512 times higher than MICs, and MBECs were atleast 512 times higher than MBICs. Thus, the presence of biofilm in allogeneicskin likely contributes to the inefficiency of the applied treatments as antibiotictolerance is known to be much higher when bacteria are in the biofilmconformation. Thus, antibiotic treatment protocols in skin banks shouldconsider biofilm formation and should include compounds with antibiofilmaction.
全球范围内的人类皮肤库都面临着一个严重的问题，即大量同种异体皮肤由于持续的细菌污染而被丢弃，无法用于移植，即使经过抗生素治疗也是如此。这些微生物的生物膜形成能力可能有助于其对抗生素的耐受；然而，这在文献中尚未得到广泛讨论。本研究分析了从一家医院皮肤库中分离出来的同种异体人皮肤样本中的细菌菌株，这些皮肤样本由于微生物污染已被丢弃。通过结晶紫生物量定量和肉汤微量稀释法用 Resazurin 染料测定最小抑菌浓度 (MIC)、最小生物膜抑菌浓度 (MBIC) 和最小生物膜清除浓度 (MBEC)，评估了生物膜形成和对青霉素、四环素和庆大霉素的敏感性。共评估了 216 株细菌菌株，其中 204 株（94.45%）被分类为具有不同程度粘附力的生物膜形成者。MBIC 至少比 MIC 高 512 倍，而 MBEC 至少比 MBIC 高 512 倍。因此，同种异体皮肤中生物膜的存在可能导致应用治疗的效果不佳，因为当细菌处于生物膜形态时，对抗生素的耐受程度要高得多。因此，皮肤库中的抗生素治疗方案应考虑生物膜的形成，并应包含具有抗生物膜作用的化合物。
