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.
BMC Microbiol. 2018 Sep 24;18(1):121. doi: 10.1186/s12866-018-1261-1.
Bacterial contamination remains the major problem in skin banks, even after antimicrobial treatment, and results in high rates of tissue discarding. This study aimed to analyze bacterial contamination in 32 human skin allografts from the skin bank of Dr. Roberto Corrêa Chem from the Hospital Complex Santa Casa de Misericórdia de Porto Alegre. These samples were already discarded due to microbial contamination. The identification of the bacteria isolated from skin allografts was performed by matrix assisted laser desorption ionization-time of flight. The antimicrobial susceptibility of the isolates to six different classes of antimicrobials was determined using the disk-diffusion agar method, and the evaluation of the inhibitory potential was determined by the minimal inhibitory concentration (50/90) of antimicrobials already used in the skin bank and those that most isolates were susceptible to.
A total of 21 (65.6%) skin samples were contaminated with Gram-positive bacteria: 1 (4.7%) with Paenibacillus sp., 12 (61.9%) with Bacillus sp., 6 (28.5%) with Staphylococcus sp., and 2 (9.5%) with Bacillus sp. and Staphylococcus sp. Several resistance profiles, including multiresistance, were found among the isolates. Most of the isolates were susceptible to at least one of the antimicrobials used in the skin bank. All isolates were susceptible to amikacin, gentamicin, and tetracycline, which demonstrated the best inhibitory activities against the isolates and were considered as potential candidates for new antimicrobial treatments.
Bacillus, Paenibacillus, and Staphylococcus were isolated from the skin allografts, thus demonstrating the predominance of Gram-positive bacteria contamination. Other factors not related to the resistance phenotype may also be involved in the persistence of bacterial isolates in the skin allografts after antibiotic treatment. Gentamicin, amikacin, and tetracycline can be considered as an option for a more effective treatment cocktail.
即使经过抗菌处理，细菌污染仍然是皮肤库面临的主要问题，导致大量组织被丢弃。本研究旨在分析来自 Porto Alegre 圣家慈悲综合医院 Roberto Corrêa Chem 博士皮肤库的 32 个人体皮肤移植物中的细菌污染。这些样本由于微生物污染已被丢弃。从皮肤移植物中分离出的细菌的鉴定通过基质辅助激光解吸电离飞行时间来完成。使用纸片扩散琼脂法测定分离株对 6 种不同类别的抗菌药物的药敏性，并通过已在皮肤库中使用的抗菌药物和大多数分离株敏感的抗菌药物的最小抑菌浓度（50/90）来评估抑制潜力。
共有 21 份（65.6%）皮肤样本受到革兰氏阳性菌污染：1 份（4.7%）为类芽孢杆菌属，12 份（61.9%）为芽孢杆菌属，6 份（28.5%）为葡萄球菌属，2 份（9.5%）为芽孢杆菌属和葡萄球菌属。分离株中发现了多种耐药谱，包括多重耐药。大多数分离株对皮肤库中使用的至少一种抗菌药物敏感。所有分离株均对阿米卡星、庆大霉素和四环素敏感，这三种药物对分离株的抑制活性最好，被认为是新抗菌治疗的潜在候选药物。
从皮肤移植物中分离出芽孢杆菌属、类芽孢杆菌属和葡萄球菌属，表明革兰氏阳性菌污染占主导地位。在抗生素治疗后，细菌分离株在皮肤移植物中持续存在的其他因素可能与耐药表型无关。庆大霉素、阿米卡星和四环素可被视为更有效治疗方案的选择。
