Analysis of Potential Causes of Positive Microbiological Cultures in Tissue Donors

The purpose of this statistical analysis is to determine what factors are the major contributors to bacterial contamination of recovered human cadaveric tissue. In this study we analyzed factors that could contribute to an increased bacterial bioburden from recovered tissues using the following independent variables: (1) the physical recovery environment; (2) recovery before or after an autopsy; (3) the length of time from death to recovery; (4) the cause of death; (5) the length of time to complete recovery; (6) the number of staff involved with the tissue recovery; and (7) the impact of organ and skin recovery on musculoskeletal contamination rates.In these analyses we used analysis of variance of main effects on data from seven tissue banks. The scale of the analysis included 1036 donors each having multiple cultures to better control for the inherent large variation in this type of data. We looked at several dependent variables. The dependent variable that was most useful was percent positive cultures.The results of the combined data differed from analyzing the tissue banks individually. The differences in each tissue bank's procedures and techniques were responsible for most of the variability. Depending on how the data was organized, statistically significant increases in bioburden were seen with: (1) recoveries after autopsy; (2) location of the recovery; (3) length of time taken for a recovery; (4) size of the recovery team; and (5) the impact of organ and skin recovery on musculoskeletal contamination rates.In conclusion, statistical analysis of recovery cultures can be a powerful tool that may be used to indicate problems within any bank's recovery procedures or techniques.     

Disinfection of human musculoskeletal allografts in tissue banking: a systematic review

Musculoskeletal allografts are typically disinfected using antibiotics, irradiation or chemical methods but protocols vary significantly between tissue banks. It is likely that different disinfection protocols will not have the same level of microorganism kill; they may also have varying effects on the structural integrity of the tissue, which could lead to significant differences in terms of clinical outcome in recipients. Ideally, a disinfection protocol should achieve the greatest bioburden reduction with the lowest possible impact on tissue integrity. A systematic review of three databases found 68 laboratory and clinical studies that analyzed the microbial bioburden or contamination rates of musculoskeletal allografts. The use of peracetic acid–ethanol or ionizing radiation was found to be most effective for disinfection of tissues. The use of irradiation is the most frequently published method for the terminal sterilization of musculoskeletal allografts; it is widely used and its efficacy is well documented in the literature. However, effective disinfection results were still observed using the BioCleanse? Tissue Sterilization process, pulsatile lavage with antibiotics, ethylene oxide, and chlorhexidine. The variety of effective methods to reduce contamination rate or bioburden, in conjunction with limited high quality evidence provides little support for the recommendation of a single bioburden reduction method.     

Analysis of the effectiveness of Sodium Hypochlorite decontamination of cadaveric human tissues at retrieval

Bacterial contamination of tissues retrieved from cadaveric donors is a common feature worldwide, and every tissue bank, albeit using different methods, conducts decontamination to guarantee safe tissues suitable for clinical use. The effectiveness of the methods used to eradicate pathogens differs. In order to reduce the tissue bioburden at retrieval, we have introduced a new method involving rinsing tissues in a sodium hypochlorite solution. To test its effectiveness we analyzed two comparable groups of tissues: Group A: 1881 tissues, all rinsed with isotonic saline solution after retrieval, and Group B: 1968 tissues immersed in an isotonic saline solution containing sodium hypochlorite (final concentration 0.1 %) for different lengths of time and subsequently rinsed with isotonic saline. The rinsing solution of each tissue was then sampled for microbiological cultures in both groups. The resultant overall contamination rate was 40.5 % for Group A and 6.7 % for Group B, with an 82.8 % difference in the reduction of contamination between the two groups. This was especially the case for commensal skin bacteria in musculoskeletal tissue, which accounted for over half the overall contamination. Our data highlighted that decontamination with sodium hypochlorite was helpful in reducing the bacterial bioburden in tissues retrieved from cadaveric donors.     

Analysis of predisposing factors for contamination of bone and tendon allografts

Bone and tissue allografts are widely used in transplantation. The increasing demand for safe allografts must be met, while minimizing disease transmission. We analysed the incidence and potential risk factors of allograft contamination and the effectiveness of disinfection, by reviewing 22 years of tissue bank activity and 474 donor procurements. We also compared different disinfection procedures used over the 22 years. The overall contamination rate was 10.1%. Risk factors were related to the donor or procurement method. Immediate culture at the tissue recovery site diminished the rate of false positives by reducing later sample manipulation. High-virulence allograft contamination was mainly related to donor factors, while low-virulence contamination was related to procurement methods. Analysis of donor-related risk factors showed no statistical differences for age, sex, or cause of death. An intensive care unit stay was associated with less contamination with high-virulence microbes. Procurement in a setting other than an operating theatre was associated with higher contamination rate. Team experience reduced contamination. Pelvic and tendon allografts were most frequently contaminated. Proper disinfection considerably reduced the contamination rate to 3.6%. We conclude that procurement must be performed under aseptic conditions, with short delays, and by trained personnel. Grafts should be disinfected and packed as soon as possible.     

Disinfection of human skin allografts in tissue banking: a systematic review report

The use of skin allografts to temporarily replace lost or damaged skin is practiced worldwide. Naturally occurring contamination can be present on skin or can be introduced at recovery or during processing. This contamination can pose a threat to allograft recipients. Bacterial culture and disinfection of allografts are mandated, but the specific practices and methodologies are not dictated by standards. A systematic review of literature from three databases found 12 research articles that evaluated bioburden reduction processes of skin grafts. The use of broad spectrum antibiotics and antifungal agents was the most frequently identified disinfection method reported demonstrating reductions in contamination rates. It was determined that the greatest reduction in the skin allograft contamination rates utilized 0.1 % peracetic acid or 25 kGy of gamma irradiation at lower temperatures.     

Method for estimating bioburden of nonsterile cotton gauze

In new hygienically controlled plants, products often have a low level of microbial contamination, so that current methods for estimating bioburden appear to be inadequate. The adoption of efficient procedures giving consistent and reproducible results could contribute to the improvement of conventional methods for evaluating microbiological quality of products with low bioburden. The effectiveness of a washing procedure and mechanical shaking for the removal of Bacillus subtilis spores from pre-inoculated cotton gauze samples was tested in combination with a membrane filtration technique. A 45-min agitation in the presence of surfactant and glass beads improved recovery up to 70.5%, with satisfactory reproducibility. In order to compare the procedure with the current standard method, uncontaminated samples were processed to extinction by applying a repetitive treatment. When exhaustive rinses were performed in order to calculate a conversion factor, permanent entrapment of a high percentage of organisms in the cotton microfibers was highlighted: this fact may play a role in an overestimation of the extrapolated removal efficiency. Received 18 June 1996/ Accepted in revised form 22 August 1996     

Assessment of bioburden on human and animal tissues: Part 1—Results of method development and validation studies

Recovered human and animal tissues are used extensively in surgery for wound repair and reconstruction. In preparation for the validation of chemical disinfection and radiation sterilization processes, studies were performed on the development and validation of quantitative bioburden recovery methods for human bone and soft tissue and also for porcine dermis. The use of a swab-based method was not considered due to the known poor efficiency of recovery for this technique. The “exhaustive extraction” and “inoculated product” approaches to validation of a bioburden recovery efficiency factor have inherent strengths and weaknesses; in this study, tissues were inoculated and also subjected to a series of extractions to determine if/when “exhaustion” occurred. Femoral and tibial shaft rings, iliac crest wedges, sections of Achilles tendon, a soft tissue composite sample, and porcine dermis, were inoculated at several sites with Bacillus atrophaeus spores, and then subjected to either shaking by hand, mechanical shaking, or sonication plus mechanical shaking. Each of these methods of agitation were performed in combination with three rinse (extraction) fluids: phosphate buffer (Butterfield’s buffer), phosphate buffer with 0.2% polysorbate 80 (a surfactant), and water with 1% peptone and 1% polysorbate 80 (Fluid D). The highest recovery efficiencies were observed with sonication plus mechanical shaking; of the three extraction media, Fluid D gave the highest first-rinse recovery efficiency (65%) and Butterfield’s buffer gave the lowest (39%). Each of the three recovery methods, however appeared to reach “exhaustion”, a subsequent rinse giving less than 10% of the recovery found in the first rinse. The results demonstrated the importance of performing bioburden method development and validation studies. The method validation strategy described here, using a combination of tissue inoculation and repetitive extraction, showed the superiority of sonication plus mechanical shaking using Fluid D as the rinse medium. In addition, the use of only the exhaustive extraction approach could have resulted in the development of a methodology that consistently underestimated the bioburden present on/in recovered tissue.     

Assessing the impact of sanitization methods for regenerated cellulose ultrafiltration/diafiltration membrane on membrane integrity and protein quality

Ultrafiltration/diafiltration (UF/DF) is typically the final step in downstream processing of recombinant monoclonal antibody (mAb) products, which serves for protein concentration and buffer exchange. For UF/DF membranes composed of regenerated cellulose (RC), sanitization with 0.1 M sodium hydroxide is generally recommended by the supplier, but it may not be sufficient for reducing bioburden during large scale manufacturing. Therefore, more stringent sanitization methods for RC membranes are required. However, chemicals used in such sanitization step may disrupt membrane integrity, while the corresponding residuals may reduce product quality. Previous work has shown that high concentration of sodium hydroxide or addition of peracetic acid (PAA) can effectively reduce bioburden, but their effects on the RC membranes remain unknown. In this work, we assessed the impact of two sanitization methods, 0.5 M sodium hydroxide and 30 mM PAA in combination with 0.5 M sodium hydroxide, on membrane integrity and protein quality of Millipore and pall corporation (PALL) membranes. Both methods showed a similar impact as the control after performing 15 cycles. However, the addition of PAA may cause residual chemical concerns, therefore, 0.5 M sodium hydroxide was recommended as an effective and safe sanitization method for RC UF/DF membranes.     

Assessment of bioburden on human and animal tissues: Part 2—Results of testing of human tissue and qualification of a composite sample for routine bioburden determination

A quantitative method was developed and validated to assess bioburden on tissue from human donors and to compare bioburden determination results to swab culture results from the same donor. An initial study with allograft tissue from 101 donors showed a wide range of bioburden levels; values from no colony-forming units (CFU) detected to?>28,000?CFU were observed. Tissues from donors that had swab cultures negative for objectionable microorganisms generally had lower bioburden than tissues from donors where objectionable microorganisms were recovered by swab culturing. In a follow-up study with 1,445 donors, a wide range of bioburden levels was again observed on tissues from donors that were swab culture negative for objectionable microorganisms. Tissues from 885 (61%) of these donors had no recoverable bioburden (<2?CFU). Importantly, tissues from 560 (39%) of the donors had recoverable bioburden which ranged from 1 to?>24,000?CFU. Identification of bioburden isolates showed a diversity of genera and species. In compliance with the recent revision of the American Association of Tissue Banks K2.210 Standard, the quantitative bioburden determination method was validated with a composite tissue sample that contains bone and soft tissue sections tested together in one extraction vessel. A recovery efficiency of 68% was validated and the composite sample was shown to be representative of all of the tissues recovered from a donor. The use of the composite sample in conjunction with the quantitative bioburden determination method will facilitate an accurate assessment of the numbers and types of contaminating microorganisms on allografts prior to disinfection/sterilization. This information will ensure that disinfection/sterilization processes are properly validated and the capability of the overall allograft process is understood on a donor by donor basis.     

Establishment of contaminant-free perennial plants in vitro

Summary Perennial plant tissue cultures are established by disinfecting field or greenhouse-grown plant parts and transferring them to sterile medium in vitro. Typically, shoots harvested from field or greenhouse-grown plants are placed in water, either to force growth from dormant branches or to maintain them until ready for explanting. In spite of extreme care, 90 to 100% contamination rates in newly established in vitro cultures are not unusual. Experience has identified several routine procedures that reduce contamination, such as minimizing the amount of time a stem cutting is maintained in water before being explanted, adjusting pH of the medium to a more acidic condition, and using pH neutralized bleach to sterilize instruments during subculture. Other methods to reduce contamination include establishing field-grown plants in a greenhouse where inoculum levels can be better controlled, trellising vining plants to get them off the soil, avoiding wetting foliage, and selecting vigorous explants that are not in contact with soil.     

A review of melanized (black) fungal contamination in pharmaceutical products—incidence,drug recall and control measures

The aim of this study was to describe the incidence of contamination of pharmaceutical products by melanized fungi and to consider control measures in relation to bioburden and cleanrooms. This study reviews and analyses pharmaceutical product recalls and offers incidence rates of fungal detection from a typical cleanrooms. The recalls include some serious cases which resulted in the loss of life. Of different types of fungal contamination incidences some of the most damaging have been due to melanized fungi (‘black mould’), such as Exserohilum rostratum. The focus of the article is with melanized fungi. The study concludes that, from the review of recent pharmaceutical product recalls, fungal contamination is either increasingly common within cleanroom environments or the accuracy of sampling and the level of reporting has risen. The prevalence of melanized fungi in pharmaceutical facilities rests on specific virulence factors particular to these types of fungi, which are outlined. The article identifies a gap in the way that such fungi are screened for using available cultural methods. The article provides some control strategies, including assessing the suitability of disinfectants and biocides, for reducing the risk of melanized fungal incidences within the pharmaceutical facility. Understanding the fungal risk to pharmaceutical products remains a poorly understood and often overlooked aspect of pharmaceutical microbiology. This article helps to identify this risk and offer some guidance to those involved with pharmaceutical products manufacture in relation to bio‐contamination control strategies.     

Bioburden in transport solutions of human cardiovascular tissues: a comparative evaluation of direct inoculation and membrane filter technique

All cardiac allograft tissues are under potential contamination, requiring a validated terminal sterilization process or a minimal bioburden. The bioburden calculation is important to determine the bacterial burden and further decontamination and disinfection strategies for the valve processing. The aim of this study was to determine the bioburden from transport solution (TS) of heart valves obtained from non-heart-beating and heart-beating donors in different culture methods. The bioburden from TS was determined in 20 hearts donated for valve allograft tissue using membrane filter (MF) and direct inoculation. Tryptic soy agar and Sabouraud plates were incubated and colonies were counted. Ninety-five percent of samples from this study were obtained from heart-beating donors. The warm ischemic time period for heart was 1.06?±?0.74 h and the cold ischemic time period was 25.66?±?11.16 h. The mean TS volume was 232.68?±?96.67 mL (48.5–550 mL). From 20 samples directly inoculated on TSA agar plates, 2 (10%) were positive. However, when MF was used, from 20 samples in TSA, 13 (65%) were positive with a mean count of 1.36?±?4.04 CFU/mL. In Sabouraud plates, the direct inoculation was positive in 5 samples (25%) with a mean count of 0.24?±?0.56 CFU/mL. The use of MF increased the positivity to 50% (10 samples from a total of 20) with a mean of 0.28?±?0.68 CFU/mL. The positivity was superior using MF in comparison with direct inoculation (p?<?0.05). The bioburden of TS is low and MF is the technique of choice due to higher positivity.     

Micro-organisms isolated from cadaveric samples of allograft musculoskeletal tissue

Allograft musculoskeletal tissue is commonly used in orthopaedic surgical procedures. Cadaveric donors of musculoskeletal tissue supply multiple allografts such as tendons, ligaments and bone. The microbiology laboratory of the South Eastern Area Laboratory Services (SEALS, Australia) has cultured cadaveric allograft musculoskeletal tissue samples for bacterial and fungal isolates since 2006. This study will retrospectively review the micro-organisms isolated over a 6-year period, 2006–2011. Swab and tissue samples were received for bioburden testing and were inoculated onto agar and/or broth culture media. Growth was obtained from 25.1 % of cadaveric allograft musculoskeletal tissue samples received. The predominant organisms isolated were coagulase-negative staphylococci and coliforms, with the heaviest bioburden recovered from the hemipelvis. The rate of bacterial and fungal isolates from cadaveric allograft musculoskeletal tissue samples is higher than that from living donors. The type of organism isolated may influence the suitability of the allograft for transplant.     

Quantification of Encapsulated Bioburden in Spacecraft Polymer Materials by Cultivation-Dependent and Molecular Methods

Bioburden encapsulated in spacecraft polymers (such as adhesives and coatings) poses a potential risk to jeopardize scientific exploration of other celestial bodies. This is particularly critical for spacecraft components intended for hard landing. So far, it remained unclear if polymers are indeed a source of microbial contamination. In addition, data with respect to survival of microbes during the embedding/polymerization process are sparse. In this study we developed testing strategies to quantitatively examine encapsulated bioburden in five different polymers used frequently and in large quantities on spaceflight hardware. As quantitative extraction of the bioburden from polymerized (solid) materials did not prove feasible, contaminants were extracted from uncured precursors. Cultivation-based analyses revealed <0.1–2.5 colony forming units (cfu) per cm³ polymer, whereas quantitative PCR-based detection of contaminants indicated considerably higher values, despite low DNA extraction efficiency. Results obtained from this approach reflect the most conservative proxy for encapsulated bioburden, as they give the maximum bioburden of the polymers irrespective of any additional physical and chemical stress occurring during polymerization. To address the latter issue, we deployed an embedding model to elucidate and monitor the physiological status of embedded Bacillus safensis spores in a cured polymer. Staining approaches using AlexaFluor succinimidyl ester 488 (AF488), propidium monoazide (PMA), CTC (5-cyano-2,3-diotolyl tetrazolium chloride) demonstrated that embedded spores retained integrity, germination and cultivation ability even after polymerization of the adhesive Scotch-Weld 2216 B/A. Using the methods presented here, we were able to estimate the worst case contribution of encapsulated bioburden in different polymers to the bioburden of spacecraft. We demonstrated that spores were not affected by polymerization processes. Besides Planetary Protection considerations, our results could prove useful for the manufacturing of food packaging, pharmacy industry and implant technology.     

Homogeneous cultivation of animal cells for the production of virus and virus products

Homogeneous technique facilitates the cultivation of large quantities of cells, reduces the risk of contamination by eliminating many manipulations, and makes practical the control of conditions such as pH and oxygen tension. Although most animal cells will not multiply in free suspension, certain cell lines have lost the requirement of being attached to a solid surface. These cells can be subcultured indefinitely but have some resemblance to cancer cells such as their abnormal karyotype. Certain cell linen developed from human embryonic tissue maintain their diploid character after repeated subculture and would seem to be ideal for the production of vaccines. However, strict regulations exist for viral products for human injection in that only cells taken from normal tissue and subcultured but once may be used. A microcarrier method in which cells adhere to DEAE-Sephadex beads permits a suspension culture which may be termed quasihomogeneous. The attached cells may be retained by sedimentation or by screening as the medium is replaced. Cell debirs from the original tissue is difficult to remove from microcarrier cultures; modifications of the trypsinization technique have alleviated but not solved this problem. Conditions for virus replication can be less critical than those for cell growth in that oxygen tension seems to have little influence on virus production. In cases where rate of virus production increases with specific growth rate of cells, homogeneous culture would have a advantage in maintaining a high cell mogeneous culture would have a valuble advantage in maintaining a high cell growth rate for a longer time. Some virus infections destroy cells, but others cause little change in cellular mteabolism except that virus is continually produced. The latter type can be conducted with a microcarrier in continuous culture with a virus titer exceeding 10⁷ plaque forming units per milliliter for over 50 days with Rubella-infected BHK cells.     

APPLICABILITY OF RAPID METHODS FOR DETECTION OF SALMONELLA SPP. IN POULTRY FEEDS: A REVIEW

The rapid detection of pathogenic microbial species in feed is of paramount importance considering its implications for animal production and food safety. More sensitive and rapid detection of contaminated feedstuffs may lead to more selective and therefore less expensive treatment of feeds, reduced rates of transmission to a poultry host and reduced carcass contamination. In order to interrupt the cycle of Salmonella spp. transmission from feed to poultry to the consumer, more rapid detection methods to monitor these sources are needed that provide conclusive results within the time frame of feed mixing or broiler processing. Within the last decade, new variations of selective media have been investigated to increase selectivity without reducing Salmonella spp. recovery. Immunological assay methods may also decrease assay time from 96 h to within 24–30 h. But all commercially available methods still require 16 to 57 h for preenrichment, enrichment, and in some cases, postenrichment to recover sublethally injured cells before the assay can be performed. Among the molecular methods that are currently available, the polymerase chain reaction (PCR) represents a tremendous potential for the detection of low levels of pathogenic bacteria. Once optimized, rapid methods may be used to quickly, reliably and inexpensively screen a variety of feedstuffs and feed components for the presence of Salmonella spp., with the goal of minimizing both the cost of feed treatment and the horizontal transmission of Salmonella spp. from feed to poultry.     

Optimizing cell arrays for accurate functional genomics

ABSTRACT: BACKGROUND: Cellular responses emerge from a complex network of dynamic biochemical reactions. In order to investigate them is necessary to develop methods that allow perturbing a high number of gene products in a flexible and fast way. Cell arrays (CA) enable such experiments on microscope slides via reverse transfection of cellular colonies growing on spotted genetic material. In contrast to multi-well plates, CA are susceptible to contamination among neighboring spots hindering accurate quantification in cell-based screening projects. Here we have developed a quality control protocol for quantifying and minimizing contamination in CA. RESULTS: We imaged checkered CA that express two distinct fluorescent proteins and segmented images into single cells to quantify the transfection efficiency and interspot contamination. Compared with standard procedures, we measured a 3-fold reduction of contaminants when arrays containing HeLa cells were washed shortly after cell seeding. We proved that nucleic acid uptake during cell seeding rather than migration among neighboring spots was the major source of contamination. Arrays of MCF7 cells developed without the washing step showed 7-fold lower percentage of contaminant cells, demonstrating that contamination is dependent on specific cell properties. CONCLUSIONS: Previously published methodological works have focused on achieving high transfection rate in densely packed CA. Here, we focused in an equally important parameter: The interspot contamination. The presented quality control is essential for estimating the rate of contamination, a major source of false positives and negatives in current microscopy based functional genomics screenings. We have demonstrate that a washing step after seeding enhances CA quality for HeLA but is not necessary for MCF7. The described method provides a way to find optimal seeding protocols for cell lines intended to be used for the first time in CA.     

Disinfection of human cardiac valve allografts in tissue banking: systematic review report

Cardiovascular allografts are usually disinfected using antibiotics, but protocols vary significantly between tissue banks. It is likely that different disinfection protocols will not have the same level of efficacy; they may also have varying effects on the structural integrity of the tissue, which could lead to significant differences in terms of clinical outcome in recipients. Ideally, a disinfection protocol should achieve the greatest bioburden reduction with the lowest possible impact on tissue integrity. We conducted a systematic review of methods applied to disinfect cardiovascular tissues. The use of multiple broad spectrum antibiotics in conjunction with an antifungal agent resulted in the greatest reduction in bioburden. Antibiotic incubation periods were limited to less than 24 h, and most protocols incubated tissues at 4 °C, however one study demonstrated a greater reduction of microbial load at 37 °C. None of the reviewed studies looked at the impact of these disinfection protocols on the risk of infection or any other clinical outcome in recipients.     

达芬奇机器人辅助腹腔镜下前列腺癌根治术的临床疗效及术后短期尿控恢复的影响因素分析

摘要 目的：观察达芬奇机器人辅助腹腔镜下前列腺癌根治术（RALRP）的临床疗效,并分析术后尿控恢复的影响因素。方法：选取2020年3月~2023年1月期间山东第一医科大学附属省立医院收治的腹腔镜下前列腺癌根治术182例作为研究对象,根据手术方式的不同将患者分为A组（n=81,传统腹腔镜前列腺癌根治术）和B组（n=101,RALRP）。记录两组手术时间、术后1个月的尿控率、术中出血量、住院时间、尿管拔除时间、引流管拔除时间、术后并发症的发生率。针对RALRP患者,多因素Logistic回归分析术后短期尿控恢复的影响因素。结果：B组手术时间、引流管拔除时间、尿管拔除时间、住院时间短于A组,术中出血量少于A组（P<0.05）。B组术后1个月的尿控率高于A组（P<0.05）。B组的术后并发症的发生率低于A组（P<0.05）。多因素Logistic回归分析结果显示,糖尿病、经尿道前列腺电切术（TURP）史是术后尿控恢复的危险因素,而规律提肛锻炼、保留神经血管束（NVB）是术后尿控恢复的保护因素（P<0.05）。结论：RALRP治疗前列腺癌患者,可缩短手术时间、引流管拔除时间、尿管拔除时间、住院时间,减少术中出血量,同时还可提高术后1个月的尿控率,降低并发症发生率。此外,糖尿病、规律提肛锻炼、保留NVB、TURP史等均是RALRP患者术后短期尿控恢复的影响因素,值得引起重视。     

Evaluation of alcohol wipes used during aseptic manufacturing

Aim: During aseptic manufacturing and specifically during the transfer of items into an isolator, disinfection of surfaces is essential for reducing the risk of final product contamination. Surface disinfection can be carried out by a variety of methods, however the most accepted current practice is a combination of spraying with 70% alcohol and wiping. The aim of this study was to evaluate the effectiveness of two wipe systems by determining their ability to remove, kill and transfer bacterial contaminants from standardized surfaces. Methods and Results: The protocol used to achieve these objectives was based on a newly published method specifically designed to test wipes. Alcohol impregnated wipes performed better at reducing microbial bioburden than the alcohol spray/dry wipe applications. Impregnated wipes drastically reduced (1–2 log₁₀ reduction) a small bioburden (approx. 2 log₁₀) of spores of Bacillus subtilis and methicillin‐resistant Staphylococcus aureus from the surface, but failed to remove (<0·2 log₁₀ reduction) Staphylococcus epidermidis. The alcohol spray/dry wipes did not manage to remove (<0·2 log₁₀ reduction) spore or bacterial bioburden from surfaces and was able to transfer some viable micro‐organisms to other surfaces. Both wipe types showed poor antimicrobial efficacy (<1 log₁₀ reduction) against the test bacteria and spores. Conclusions: As far as the authors are aware this is the first time that such a practical study has been reported and our results suggest that the best wipes for surface disinfection in aseptic units are the alcohol (IPA) impregnated wipes when compared with the dry wipes sprayed with alcohol. Significance and Impact of the Study: The impregnated wipes performed better than the dry wipes sprayed with alcohol and should be used for surface disinfection in aseptic units.