Safety is a major issue in the embalming procedures of human cadavers. Reduced application of formaldehyde is often recommended. The aim of this study was to investigate the potency of ultraviolet light (UV-C irradiation) on the bacterial load on the surface of a conserved human cadaver. To test UV-C irradiation, the cadaver was laid out in the dissection hall and, after preparation of the muscles, was covered with linen sheets moistened with water. Swabs of the surface and microbiological analysis revealed sporadic bacterial colonies. The surface area was then spiked with bacteria and irradiated by a UV lamp for 15 or 60 min. Half of the area was covered by aluminum foil to serve as a control. After exposition, swabs were taken and analyzed. The exposition had reduced the number of colonies to one third (15 min exposition) and to one tenth (60 min exposition) of the control area. Thus, UV-C irradiation could be used in the preservation of cadavers without chemical pollution of the environment and without any risk for the employees. Clin. Anat. 32:113–116, 2019. © 2019 The Authors. Clinical Anatomy published by Wiley Periodicals LLC on behalf of American Association of Clinical Anatomists

Bischoff, Markus

Müller, Lea

Tschernig, Thomas

Clinical Anatomy

English

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ORIGINAL COMMUNICATIONUV-C Irradiation Reduces the ExperimentallyInduced Bacterial Load on the Surfaceof a Human Cadaver: An Additional Optionfor the Preservation of Cadavers in AnatomyLEA MÜLLER,1 MARKUS BISCHOFF,2 AND THOMAS TSCHERNIG 1*1Institute of Anatomy and Cell Biology, Medical Faculty, Saarland University, Homburg/Saar, Germany2Institute of Microbiology and Hygiene, Medical Faculty, Saarland University, Homburg/Saar, GermanySafety is a major issue in the embalming procedures of human cadavers. Reducedapplication of formaldehyde is often recommended. The aim of this study was toinvestigate the potency of ultraviolet light (UV-C irradiation) on the bacterial loadon the surface of a conserved human cadaver. To test UV-C irradiation, thecadaver was laid out in the dissection hall and, after preparation of the muscles,was covered with linen sheets moistened with water. Swabs of the surface andmicrobiological analysis revealed sporadic bacterial colonies. The surface areawas then spiked with bacteria and irradiated by a UV lamp for 15 or 60 min. Half ofthe area was covered by aluminum foil to serve as a control. After exposition,swabs were taken and analyzed. The exposition had reduced the number of colo-nies to one third (15 min exposition) and to one tenth (60 min exposition) of thecontrol area. Thus, UV-C irradiation could be used in the preservation of cadaverswithout chemical pollution of the environment and without any risk for theemployees. Clin. Anat. 33:113–116, 2020. © 2019 Wiley Periodicals, Inc.Key words: ultraviolet light; UV-C; human cadaver; bacterial; saving of fixativeINTRODUCTIONIn the past, environmental and safety issues havebeen a major topic in the discussion of embalming pro-cedures applied to human cadavers (Mercer, 1992).This year a paper by Waschke et al. (2019) was pres-ented by the Society of Anatomists (AnatomischeGesellschaft) as a consensus publication. Waschkeet al.’s (2019) publication contained recommendationsfor a reduction in the amount of formaldehyde used byanatomical institutes in the embalming of humancadavers, especially in solutions for body perfusion andimmersion tanks. The recommendation was to reducethe concentration of formaldehyde to 2% or less. Alsofor the preservation of the cadavers in the dis-section hall, 2% phenoxy-ethanol was recommended.Due to the fact that it is odorless, phenoxy-ethanol ispleasant to use; however, it remains a source of dan-gerous emission. This study tests an effective, nontoxicand inexpensive option, which not only reduces theconcentration of fixatives but also controls bacterialcontamination of cadavers.METHODSPreservationThe experiment was conducted on a male cadaver,77 years old at the time of death. The cadaver hadbeen preserved for 2 years prior to the experiment.*Correspondence to: Thomas Tschernig, MD, Institute of Anatomyand Cell Biology, Saarland University, Campus Homburg,Kirrberger Strasse, Building 61, 66424 Homburg/Saar, Germany,E-mail: thomas.tschernig@uks.eu, Phone: +496841 1626 100,Fax: +496841 1626 121Received 25 June 2019; Revised 19 August 2019; Accepted 14September 2019Published online 9 October 2019 in Wiley Online Library(wileyonlinelibrary.com). DOI: 10.1002/ca.23481© 2019 The Authors. Clinical Anatomy published by Wiley Periodicals LLC on behalf of AmericanAssociation of Clinical Anatomists.This is an open access article under the terms of the Creative Commons Attribution License, which permits use,distribution and reproduction in any medium, provided the original work is properly cited.Clinical Anatomy 33:113–116 (2020)Solution A was used for intra-arterial instillation andSolution B was used for the immersion tank (Table 1).Some months before the experiment, a dissection hadbeen performed and the body had been covered witha linen sheet moistened with 1.5% phenoxy-ethanol.Two weeks prior to the experiment, the linen sheetwas replaced by a sheet moistened with water. Thiswas necessary as probes from body surfaces coveredwith phenoxy-ethanol-soaked sheet had yielded no,or only sporadic, colonies at commencement of sam-pling, which was several days prior to the commence-ment of the experiment.Ultraviolet Irradiation DeviceAs shown in Figure 1, a commercial and industrialUV lamp emitting ultraviolet irradiation C (253.7 nmwave length, UV 72W, UVECO GmbH, Bruckmühl,Germany) was adapted for use at anatomical tables.The lamp was fixed using tension belts, which permit-ted easy transfer from table to table and adjustmentin height. A 360 motion detector was connected in aninverse mode to avoid any risk for staff and students.The lamp switched off automatically if anybodyapproached within a radius of 10 m. The setting ofexposure is presented in Figure 2.Experimentally Induced Bacterial LoadAliquots (100 μl) of an Escherichia coli DSM 1103McFarland 0.5 solution diluted in Dulbecco’s ModifiedEagle’s medium to the colony forming units (CFU)rates indicated were placed with an eSwab tip on25 cm2 areas on a leg muscle of the cadaver (highinoculum: 7 x 105 CFU, low inoculum: 7 x 103 CFU).Spiked areas were either covered with aluminum foilor left exposed.Exposure to Ultraviolet RadiationThe spiked areas were subsequently exposed toUV-C for 15 and 60 min. During irradiation the bodywas not covered with water-moistened linen sheets.Sampling of Bacteria on Body SurfacesAfter exposition, the areas were probed with a fresheSwab tip, prewetted with Amies transport medium,TABLE 1. Solution A (Instillation) and B(Immersion Tank) for Conservation of HumanCadaversCompounds Solution A Solution BWater (l) 39 923Formaldehyde 39% (l) 3 77Sorbitol (l) 12Lysoformin®a (l) 2.7Calciumchloride (kg) 0.6Choralhydrate (kg) 3Thymol (g) 12Natriumchloride (kg) 2.4Formaldehyde concentration(%) (as measuredusing gas chromatography)Approx. 5 Approx. 3aLysoform, Berlin, Germany.Fig. 1. An ultraviolet lamp mounted above a dis-section table. Also visible is the motion detector that pre-vents irradiation of any person nearby.Fig. 2. Two areas of skeletal muscle comparable in sizewere labeled and one was covered using aluminum foil.Swabs were taken from both areas after UV-C irradiation.[Color figure can be viewed at wileyonlinelibrary.com]114 Müller et al.the tip was then placed into the transport tube of thissystem. Recovered bacteria were detached from thetip by vortexing the tube for 5 sec and 100 μl of thetransport medium were subsequently streaked ontoblood agar plates. Colonies formed on the plates werecounted after 18 hr of incubation at 37C. Expositionwas also performed for 6 hr in order to examine theeffects of long exposure.Specimen IdentificationVegetation on conserved cadavers were sampled witheSwab systems (Copan, Murrieta, CA) and plated ontosheep blood agar plates. Plates were cultured for 48 hrat room temperature and 37C, respectively, and colo-nies were analyzed by matrix-assisted laser desorptionionization-time of flight-mass spectrometry (MALDI-TOF-MS) and subsequently compared with the Biotyper3.0 database (Bruker Daltronik GmbH, Bremen, Ger-many) for species determination.RESULTSAs shown in Figure 3, the number of bacterial colo-nies (CFU) on blood agar plates after 60 min of exposi-tion to UV light was markedly reduced. In the transportmedium of swabs from the foil-covered area with highinoculum, 466 colonies were detected. In the mediumfrom the noncovered area, only 41 colonies were found.This is a one-tenth reduction in comparison to the cov-ered, nonexposed area. In the medium of the foil-covered area with low inoculum, six colonies wereobserved versus zero colonies after UV-C exposition. Inthe trial with an exposure time of 15 min, the reductionwas about one third as compared to the nonexposedarea (934 vs. 364 CFU and 148 vs. 42 CFU, respec-tively). No changes in color or rigidity of the tissue wereobserved after a long exposure time of 6 hr.An additional—nonexperiment related—observationwas made. Another cadaver developed spotty and con-fluent colonies on some parts of the muscle and organsurfaces despite being covered with a phenoxy-ethanol-soaked linen sheet. Mechanical cleaning and washingwith Lysoformin (Table 1) was effective, but only for afew weeks. A microbiological analysis detected nobacteria in probes of these smears. Using matrix-assisted laser desorption—time of flight mass spectrom-etry, the fungus, Candida famata (sive Candida flareri,Debaryomyces hansenii), was identified (identificationscore 2.2). This fungus belongs to the flavinogenicyeasts, has a high osmo-tolerance (Dmytruk andSibirny, 2012), and is specialized to moist and cold envi-ronments as described by Desnos-Ollivier et al. (2008).A 60-min UV-C irradiation led to a “melting” of the colo-nies and smears. In order to prevent loss of the body, itwas transferred for 6 weeks to an immersion tank con-taining water with 5% formaldehyde. The fungus hadnot reappeared since the body was returned to the dis-section table 2months later.DISCUSSION AND CONCLUSIONAll cadavers in anatomy are primary contaminatedwith bacteria and fungi. After preservation with bacteri-cidal fixatives, secondary contamination occurs duringthe dissection, caused by dissectors and others. Thegrowth of bacteria and fungi is prevented by using linensheets that have been moistened with solutions con-taining bactericidal substances such as phenoxy-etha-nol. All antimicrobial fixatives in tissues, fluids, and theair are more or less harmful to humans. Variousapproaches toward a reduction of harmful effects havebeen tested. One method was the extraction orexchange of room air containing formaldehyde. Sincethen, dissection tables have become available that canbe docked to extraction units and that withdrawformaldehyde-contaminated air from the bodies bysuction. Another method is the chemical neutralizationof formaldehyde after the preservation procedure(e.g., InfutraceTM, American Bio-Safety, Rocklin, CA).An obvious approach is the reduction of fixatives or theirconcentration. However, at a certain point the reductionof fixatives in the preservation and maintenance ofcadavers in medicine and veterinary medicine leads toproblems with bacteria (e.g., staphylococci) and fungi(e.g., Candida famata). The search for alternatives tochemicals drew our attention to UV-C irradiation. UV-Cexposure is widely used in industry and cell culture labsfor the elimination of bacteria and fungi. As the effect ofUV-C irradiation is physical destruction, no resistancesdevelop and no environmental contamination occurs.Thus, the effect established in this short study hasstrengthened the prospects for a possible effective appli-cation of UV-C irradiation in the preservation of cadaversin the anatomical field. There are limitations andFig. 3. Representative images of the incubated bloodagar plates with smears of transport medium are shown.Samples were taken from areas with and without UVexposition and from two inocula as indicated. [Color fig-ure can be viewed at wileyonlinelibrary.com]UV lamp exposition of cadavers 115problems: Only the surface can be exposed to the UVlight, it is doubtful whether UV light can be used for asitus, and it is also not fully clear which exposure timesand intervals are necessary in order to maintain suffi-cient antimicrobial protection of the cadavers. Theauthors recommend UV-C irradiation exposure for60 min once a week while constant work is being per-formed on the bodies. If no, or only occasional, work isbeing carried out, then 60 min of exposure once permonth is sufficient, provided that the linen sheetscovering the cadavers are moistened with at least 1%phenoxy-ethanol.Altogether, UV-C irradiationmight be a simple, effec-tive, and an environmentally sound complementarytool in the maintenance of human cadavers in anatomy.ACKNOWLEDGMENTSThe authors thank Christoph Neuhardt for the UVlamp construction, Irina Scheck and Ronald Dollwettfor the preparation of the human cadavers. Theauthors also wish to thank Helga Meyer and BarbaraMichahelles-Horzella for their excellent work in thebody donation group and Ann Söther for polishing thelanguage.ABBREVIATIONSCFU colony forming unitsUV-C ultraviolet light CREFERENCESDesnos-Ollivier M, Ragon M, Robert V, Raoux D, Gantier JC, Dromer F.2008. Debaryomyces hansenii (Candida famata), a rare humanfungal pathogen often misidentified as Pichia guilliermondii (Can-dida guilliermondii). J Clin Microbiol 46:3237–3242.Dmytruk KV, Sibirny AA. 2012. Candida famata (Candida flareri).Yeast 29:453–458.Mercer DO. 1992. Formaldehyde and clinical anatomy: safe use andregulatory concerns. Clin Anat 5:404–408.Waschke J, Bergmann M, Bräuer L, Brenner E, Buchhorn A, Deutsch A,Dokter M, Egu DT, Ergün S, Fassnacht U, Fietz D, Gundlach S,Heermann S, Hirt B, Kugelmann D, Müller-Gerbl M, Neiss W,Nimtschke U, Plendl J, Pretterklieber M, Redies C, Scaal M,Schmidt MHH, Schmiedl A, Schnittler HJ, Schomerus C, Sebestény T,Spittau B, Steiniger B, Tschernig T, Unverzagt A, Viebahn C, Voigt E,Weigner J, Weyers I, Winkelmann A,Winkler M, Paulsen F. 2019. Rec-ommendations of the working group of the Anatomische Gesellschafton reduction of formaldehyde exposure in anatomical curricula andinstitutes. Ann Anat 221:179–185.116 Müller et al.

UV-C Irradiation Reduces the Experimentally Induced Bacterial Load on the Surface of a Human Cadaver: An Additional Option for the Preservation of Cadavers in Anatomy

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UV-C Irradiation Reduces the Experimentally Induced Bacterial Load on the Surface of a Human Cadaver: An Additional Option for the Preservation of Cadavers in Anatomy

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