Bacterial contamination of human skin allografts and antimicrobial resistance: a skin bank problem

Abstract

BackgroundBacterial 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.ResultsA 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.ConclusionsBacillus, 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.Electronic supplementary materialThe online version of this article (10.1186/s12866-018-1261-1) contains supplementary material, which is available to authorized users.

Antibiotic resistance profile of local thermophilic Bacillus licheniformis isolated from Maysan province soil

“…The MIC test was susceptible to tetracycline (8.0 mg / litre), vancomycin (4.0 mg / litre), and gentamicin (4.0 mg / litre), but was streptomycin resistant (Adimpong et al, 2012). Moreover, disc diffusion assay was reported for antibiotic resistance profiles in the genus of Bacillus particularly for B. cereus (Gao et al, 2018;Fiedler et al, 2019;Park et al, 2020), in contrast very few was reported for B. licheniformis (Jeong et al, 2017;Meneghetti et al, 2018). Because of the limitation of data which is available about the resistance of B. licheniformis and to provide a guidance value to clinicians encountering possibly B. licheniformis infections; this study was aimed to detect the antibiotic resistance profile of local thermophilic B. licheniformis isolated from soil in Maysan Province, Iraq.…”

Coagulase-negative staphylococci in outpatient routines: the implications of switching from CLSI to BrCAST/EUCAST guidelines

“…Table 2 summarizes the susceptibilities, agreement, and kappa statistics for both guidelines. Of the 65 CoNS tested, 10 (15.4%) -CLSI and 14 (21.9%) -BrCAST/EUCAST were resistant to at least three antimicrobial classes and were therefore classified as multidrug resistant (MDR) [9] with a concordance of 93.8% (Table 3).…”

“…For fast bacterial identification, isolates were plated on Mueller-Hinton agar, and matrix-assisted laser desorption ionizationtime of flight (MALDI-TOF) methodology was performed out in the Microflex LT (Bruker Corporation, USA) platform according to the manufacturer's specifications for direct colony identification. The spectra were analyzed using MALDI Biotyper 4.0 software and standard pattern matching with a default setting in accordance with previously studies [9].…”

The Establishment of a High Standard Skin Bank in Taiwan as a Burn Care Pioneer

“…With its long-term storage temperature of 4°C, the low storage and transportation cost is one of the main advantages of the GPA. However, a disadvantage of the method is the observation of occasional contamination by the Bacillus bacteria [7]. Gamma-radiation has also been utilized by surgeons to decrease the contamination rate without harming the function of the skin allograft [8,9].…”