Bioburden Reduction Research Articles

Ultraviolet-C light as a means of disinfecting anesthesia workstations

Anesthesia workstations (AWs) are a reservoir for pathogenic organisms potentially associated with surgical site infections. This study examined the effectiveness of the Tru-D SmartUVC device (Tru-D LLC, Nashville, TN) on bioburden reduction (BR) on AWs. Strips of tissue inoculated with a known concentration of either Staphylococcus aureus, Enterococcus faecalis, or Acinetobacter sp were placed on 22 high-touch surfaces of an AW. Half of the AW surfaces received direct ultraviolet (UV) light exposure and half received indirect exposure. Two inoculated strips, in sterile tubes outside of the room, represented the control. Trials were conducted on AWs in an operating room and a small room. Strips were placed in a saline solution, vortexed, and plated on blood agar to assess BR by the number of colony forming units. All experimental trials, compared with controls, exhibited a BR >99%. There was a significantly greater reduction of E faecalis colony forming units in the operating room AW under direct exposure (P = .019) compared with indirect exposure. There was no significant difference in reduction when comparing AWs between rooms. Regardless of room size and exposure type, automated UV-C treatment greatly influences BR on AW high-touch surfaces. Hospitals instituting an automated UV-C system as an infection prevention adjunct should consider utilizing it in operating rooms for BR as part of a horizontal infection prevention surgical site infection-reduction strategy.

Self-sanitizing copper-impregnated surfaces for bioburden reduction in patient rooms.

Novel self-sanitizing copper oxide-impregnated solid surfaces have the potential to influence bioburden levels, potentially lowering the risk of transmission of pathogens in patient care environments. Our study showed persistently lower microbial burden over a 30-hour sampling period on a copper-impregnated tray table compared with a standard noncopper surface in occupied patient rooms after thorough initial disinfection.

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.Electronic supplementary materialThe online version of this article (doi:10.1007/s10561-016-9584-3) contains supplementary material, which is available to authorized users.

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.Electronic supplementary materialThe online version of this article (doi:10.1007/s10561-016-9570-9) contains supplementary material, which is available to authorized users.

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.Electronic supplementary materialThe online version of this article (doi:10.1007/s10561-016-9569-2) contains supplementary material, which is available to authorized users.

Negative pressure wound therapy with instillation (NPWTi): Current status, recommendations and perspectives in the context of modern wound therapy.

Introduction of negative pressure wound therapy (NPWT) revolutionized the conception of wound healing. Currently, there are an increased number of studies confirmed the high efficiency of this therapy in many clinical scenarios. Moreover, some innovations have been introduced in recent years to improve the management of complex and chronic wound.NPWT with instillation (NPWTi) combines traditional NPWT with application of topical irrigation solutions within bed of the wound. Bioburden reduction, decrease time to wound closure, promotion in granulation tissue formation, fewer operative visits have been revealed using NPWTi compared to standard NPWT.However, there are still some questioned aspect of the NPWTi and thus its superiority over standard NPWT has not been fully indicated. Moreover, based on current studies no firm conclusions have been taken concerning the type of instilled solution preferably used, range of dwell- time phase, range of negative pressure and others.The main goal of the publication is to overview and summarize the current state of art concerning NPWTi. Moreover, mechanisms of action, review of the most common used instilled solution are discussed and clinical evidence of NPWTi are described.

Technologies for hospital disinfection and textiles for bioburden reduction

Abstract: Reduction of microbial contamination of the hospital environment is a challenge yet has potential impacts on infection prevention efforts. This lecture will explore the potential role of new technologies to limit bioburden on inanimate surfaces and healthcare worker uniforms. The literature on new technologies such as antimicrobial textiles, hydrogen peroxide and UV light-based decontamination systems for cleaning of hospital rooms will be explored. Knowledge gaps on cleaning of hospital surfaces are summarized and the application of these technologies as part of a horizontal infection prevention platform will be discussed.

Hydrogen peroxide room disinfection--ready for prime time?

Non-manual techniques for terminal disinfection of hospital rooms have gained increasing interest in recent years as means to reduce transmission of multidrug-resistant organisms (MDROs). A prospective crossover study by Blazejewski and colleagues in five ICUs of a French academic hospital with a high prevalence of MDRO carriers showed that two different hydrogen peroxide (H2O2)-based non-touch disinfection techniques reduced environmental contamination with MDROs after routine cleaning. This study provides further evidence of the ‘in use’ bioburden reduction offered by these techniques. Before H2O2-based non-touch disinfection can be recommended for routine clinical use outside specific outbreak situations, further studies need to show whether the environmental contamination reduction provided by these techniques is clinically relevant and results in reduced cross-infections with MDROs.

New Twist on an Old Favorite: Gentian Violet and Methylene Blue Antibacterial Foams

Significance: Absorptive antibacterial dressings that assist in controlling bioburden without risks of cytotoxicity or residual absorption can be effectively used for prolonged periods throughout the wound healing continuum. Recent Advances: Until recently, gentian violet and methylene blue (GV/MB) antibacterial dressings have been commercially available only in polyvinyl alcohol (PVA) foam; polyurethane (PU) foam bonded with GV and MB with thin film backing is now commercially available. GV/MB PU foam does not require hydration or a necessary secondary dressing. GV/MB PVA and PU foam dressings were recently granted FDA clearance as antibacterial dressings, as opposed to bacteriostatic dressings as previously classified. Within the class of antibacterial dressings, GV/MB foam dressings are of lower cost alternative to silver- or iodine-based antibacterial dressings with no risk of absorption of any of the foam components into the tissues. Critical Issues: Control of wound bioburden levels by antibacterial agents and absorption of excess exudate are crucial in preventing infections that drastically increase the price of wound care. Use of GV/MB dressings may improve wound healing outcomes and decrease overall costs through super absorption, promotion of autolytic debridement, bioburden reduction, ease of use, and decreased dressing change frequency. Future Directions: Evolution in resistant bacterial strains will drive continual changes in advanced wound care products. Demand will increase for economically priced, versatile wound care dressings that assist in debridement, maintain a moist wound environment, absorb and trap bacterial debris, and decrease dressing change frequency.

A biomechanical characterisation of acellular porcine super flexor tendons for use in anterior cruciate ligament replacement: Investigation into the effects of fat reduction and bioburden reduction bioprocesses

The decellularisation of xenogenic and allogeneic biological grafts offers a promising solution to replacement of the anterior cruciate ligament (ACL). The purpose of this investigation was to determine the biomechanical effects of additional fat reduction and bioburden reduction steps in the decellularisation of porcine super flexor tendon (pSFT). Study 1 investigated the use of acetone or chloroform–methanol as a fat reduction agent. The most effective of these was then carried forward into Study 2, which investigated the use of antibiotics or peracetic acid (PAA) as a bioburden reduction agent. Stress relaxation data was analysed using a Maxwell–Wiechert viscoelastic model and, in addition to classical material properties, the tangent modulus of the toe-region was determined from strength testing data. In both studies, the majority of decellularised groups demonstrated no statistical differences for material properties such as tensile strength and Young’s modulus compared to native controls. Different trends were observed for many of the viscoelastic parameters, but also for the tangent modulus in the toe-region indicating a change in performance at low strains. The most severe deviations from the profile of the native tangent modulus were found to occur in Study 2 when PAA was used for bioburden reduction. Classic material properties (E, UTS etc.) are often used to compare the characteristics of native and decellularised tissues, however they may not highlight changes occurring in the tissues at low strains. In this study, this represented the physiological strains encountered by substitute acellular ACL grafts. Acetone was chosen as the fat reduction step whereas, antibiotics was preferable over PAA as a bioburden reduction step.

Aqueous oxygen peroxide treatment of VLUs in a primary care-based randomised, double-blind, placebo-controlled trial.

To evaluate a novel aqueous oxygen peroxide (AOP) wound therapy (BioxyQuell) in a multi-centre, primary care-based, randomised, double-blind, placebo-controlled, parallel-group trial, monitoring long-term healing outcomes over 12 months. Sixty-one patients with chronic, stable venous leg ulceration were treated with either AOP solution or sterile water placebo applied as a lavage over 2 weeks. The patients' wounds were dressed weekly and assessed fortnightly over the following 6 weeks. Patients who completed the initial 8-week trial were invited into a 10-month follow-up trial. The primary endpoints of the study were wound healing at 8 weeks, 12 weeks, 6 months and 12 months, and wound size reduction during the treatment phase. Secondary endpoints were reductions in wound bioburden and pain. Patients treated with AOP were more likely to heal at 6 months (p=0.014) and 12 months (p=0.006), but not at 8 weeks (p=0.979) or 12 weeks (p=0.263). Patients treated with AOP had greater wound area reduction (p=0.015), reductions in pain measured on a 100-point scale (p=0.001) and wound bioburden reduction (p=0.005) during the treatment phase. The addition of AOP treatment provides substantial benefits to patients with chronic venous leg ulceration compared with current best practice.

Improved Outcomes in the Management of High‐Risk Incisional Hernias Utilizing Biological Mesh and Soft‐Tissue Reconstruction: A Single Center Experience

Repair of incisional hernias is complex in the setting of previous/current infection, loss of domain and bowel involvement, and is often on the background of significant co-morbidities. Reported repair techniques are associated with significant morbidity and led our unit to develop a novel technique for complex incisional hernia repair. A retrospective case notes review of all high-risk (Ventral Hernia Working Group grade 2-4) incisional hernia repairs was undertaken. Standardized repair involved resection of attenuated soft tissue and hernia sac (bioburden reduction), component separation (where necessary), intra-peritoneal Strattice™ biological mesh insertion, midline fascial closure, and soft-tissue reconstruction, performed in combination with a plastic surgeon as a single-stage procedure. A total of 58 patients underwent hernia repair between February 2009 and September 2012 (median age 59 years; 59 % female). Eleven patients (19 %) were grade 4, 19 (33 %) were grade 3, and 28 (48 %) were grade 2. Nineteen (33 %) were recurrent hernias, and midline fascial closure was achieved in 52 (90 %). Early complications included 15 (26 %) surgical-site occurrences, three (5 %) respiratory complications, two (3 %) cardiac complications, and two (3 %) urinary tract infections. Follow-up has revealed three (5 %) asymptomatic hernia recurrences and no patients requiring mesh explantation. This technique was associated with a low risk of surgical site occurrences and hernia recurrence, with no requirements for mesh explantation. Repair of such complex incisional hernias remains challenging, and further randomized controlled trials are required to elucidate the optimal method of closure and mesh type.

Microbes in the Upper Atmosphere and Unique Opportunities for Astrobiology Research

Microbial taxa from every major biological lineage have been detected in Earth's upper atmosphere. The goal of this review is to communicate (1) relevant astrobiology questions that can be addressed with upper atmosphere microbiology studies and (2) available sampling methods for collecting microbes at extreme altitudes. Precipitation, mountain stations, airplanes, balloons, rockets, and satellites are all feasible routes for conducting aerobiology research. However, more efficient air samplers are needed, and contamination is also a pervasive problem in the field. Measuring microbial signatures without false positives in the upper atmosphere might contribute to sterilization and bioburden reduction methods for proposed astrobiology missions. Intriguingly, environmental conditions in the upper atmosphere resemble the surface conditions of Mars (extreme cold, hypobaria, desiccation, and irradiation). Whether terrestrial microbes are active in the upper atmosphere is an area of intense research interest. If, in fact, microbial metabolism, growth, or replication is achievable independent of Earth's surface, then the search for habitable zones on other worlds should be broadened to include atmospheres (e.g., the high-altitude clouds of Venus). Furthermore, viable cells in the heavily irradiated upper atmosphere of Earth could help identify microbial genes or enzymes that bestow radiation resistance. Compelling astrobiology questions on the origin of life (if the atmosphere synthesized organic aerosols), evolution (if airborne transport influenced microbial mutation rates and speciation), and panspermia (outbound or inbound) are also testable in Earth's upper atmosphere.

Europa planetary protection for Juno Jupiter Orbiter

NASA’s Juno mission launched in 2011 and will explore Jupiter and its near environment starting in 2016. Planetary protection requirements for avoiding the contamination of Europa have been taken into account in the Juno mission design. In particular Juno’s polar orbit, which enables scientific investigations of parts of Jupiter’s environment never before visited, also greatly assist avoiding close flybys of Europa and the other Galilean satellites.The science mission is designed to conclude with a deorbit burn that disposes of the spacecraft in Jupiter’s atmosphere. Compliance with planetary protection requirements is verified through a set of analyses including analysis of initial bioburden, analysis of the effect of bioburden reduction due to the space and Jovian radiation environments, probabilistic risk assessment of successful deorbit, Monte-Carlo orbit propagation, and bioburden reduction in the event of impact with an icy body.

Impact of H 2 O 2 Decontamination Technology Over High Heat Sterilization: Increased Efficiency and Efficacy with Significantly Reduced Downtime

BioTechniquesVol. 54, No. 3 Application Forum - Sponsored PaperOpen AccessImpact of H2O2 Decontamination Technology Over High Heat Sterilization: Increased Efficiency and Efficacy with Significantly Reduced DowntimeDeepak M. Mistry & Nehal KothariDeepak M. MistryStrategic Development & MarketingSearch for more papers by this author & Nehal KothariStrategic Marketing & Application SpecialistSearch for more papers by this authorPublished Online:3 Apr 2018https://doi.org/10.2144/000114016AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinkedInRedditEmail IntroductionContamination of cell cultures is easily the most common problem encountered in cell culture laboratories and can lead to very serious consequences. Of all the likely sources, the cell culture incubator has often been considered one of the most probable sources of biological contamination. Many incubator manufacturers have addressed this issue using different types of sterilization technologies.Determining the Most Efficient and Effective TechniqueA study was undertaken to determine the effectiveness and efficiency of three industry-leading incubators that utilize different sterilization techniques: Panasonic's MCO- 19AIC UVH with H2O2 decontamination technology that requires 2 hours for its cycle with around 15 minutes of prep time, Brand A with a dry heat sterilization method that takes 10-12 hours for the complete process, and Brand B with a moist heat sterilization method that requires up to 25 hours from start to finish. Five different microorganisms, generally considered the most common contaminants in a cell culture environment, were tested in this study: Candida albicans, Acholeplasma laidlawii, Mycoplasma orale, Bacillus subtilis, and Staphylococcus aureus.At a specific number of colony forming units (CFUs), each organism was placed on both upper and lower shelves of the incubators, which were then allowed to go through their individual sterilization cycle. A time control coupon was also run simultaneously for the same amount of time as the sterilization cycle.Each of the three cell culture incubators showed complete bioburden reduction for each organism. However, Panasonic's MCO-19AIC UVH offered complete organism elimination in 2 hours, as compared to 10-12 hours and 25 hours for Brand A and Brand B, respectively. In addition, a reduction in viability was observed for Candida albicans, Acholeplasma laidlawii and Mycoplasma orale when each time control was compared. The Panasonic MCO-19AIC UVH effectively showed a greater bioburden reduction than Brand A and Brand B when the 2 hour time control was compared to the 10-12 hour and 25 hour time controls. This validates the effectiveness with which Panasonic's MCO-19 AIC UVH incubator decontaminates the chamber. For Staphylococcus aureus and Bacillus subtilis, an increase in viability was observed over time when compared to time controls. However, Panasonic's MCO-19 AIC UVH incubator efficiently eliminated all of the bioburden in a considerably shorter span of time without significantly increasing the original concentration of the organisms.Figure 1. Comparison of sterilization effectiveness.Bioburden reduction was measured for three types of incubators: Panasonic's MCO-19 AIC UVH, Brand A, and Brand B.ConclusionThe 2 hour uptime advantage offered by the Panasonic MCO-19AIC UVH incubator with 100% kill rate and at least a 6-log reduction for all the organisms tested, leads to increased productivity in a research or GMP environment.Go towww.SterisonicH2O2.comto download a full version of the Whitepaper.FiguresReferencesRelatedDetails Vol. 54, No. 3 Follow us on social media for the latest updates Metrics Downloaded 152 times History Published online 3 April 2018 Published in print March 2013 Information© 2013 Future Science LtdPDF download

International Heart Valve Bank Survey: A Review of Processing Practices and Activity Outcomes

A survey of 24 international heart valve banks was conducted to acquire information on heart valve processing techniques used and outcomes achieved. The objective was to provide an overview of heart valve banking activities for tissue bankers, tissue banking associations, and regulatory bodies worldwide. Despite similarities found for basic manufacturing processes, distinct differences in procedural details were also identified. The similarities included (1) use of sterile culture media for procedures, (2) antibiotic decontamination, (3) use of dimethyl sulfoxide (DMSO) as a cryoprotectant, (4) controlled rate freezing for cryopreservation, and (5) storage at ultralow temperatures of below −135°C. Differences in procedures included (1) type of sterile media used, (2) antibiotics combination, (3) temperature and duration used for bioburden reduction, (4) concentration of DMSO used for cryopreservation, and (5) storage duration for released allografts. For most banks, the primary reasons why allografts failed to meet release criteria were positive microbiological culture and abnormal morphology. On average, 85% of allografts meeting release criteria were implanted, with valve size and type being the main reasons why released allografts were not used clinically. The wide variation in percentage of allografts meeting release requirements, despite undergoing validated manufacturing procedures, justifies the need for regular review of important outcomes as cited in this paper, in order to encourage comparison and improvements in the HVBs' processes.

Negative Pressure Wound Therapy With Instillation (NPWTi) Better Reduces Post-debridement Bioburden in Chronically Infected Lower Extremity Wounds Than NPWT Alone

ObjectiveAn overabundance of bacteria in the chronic wound plays a significant role in the decreased ability for primary closure. One means of decreasing the bioburden in a wound is to operatively debride the wound for wound bed optimization prior to application of other therapy, such as Negative Pressure Wound Therapy (NPWT). We undertook a prospective pilot study to assess the efficacy of wound bed preparation for a standard algorithm (sharp surgical debridement followed by NPWT) versus one employing sharp surgical debridement followed by Negative Pressure Wound Therapy with Instillation (NPWTi). MethodsThirteen patients, corresponding to 16 chronic lower leg and foot wounds were taken to the operating room for debridement. The patients were sequentially enrolled in 2 treatment groups: the first receiving treatment with operative debridement followed by 1 week of NPWT with the instillation of quarter strength bleach solution; the other receiving a standard algorithm consisting of operative debridement and 1 week of NPWT. Quantitative cultures were taken pre-operatively after sterile preparation and draping of the wound site (POD # 0, pre-op), post-operatively once debridement was completed (POD # 0, post-op), and on post-operative day 7 after operative debridement (POD # 7, post-op). ResultsAfter operative debridement (post-operative day 0) there was a mean of 3 (±1) types of bacteria per wound. The mean CFU/gram tissue culture was statistically greater – 3.7 × 106 (±4 × 106) in the NPWTi group, while in the standard group (NPWT) the mean was 1.8 × 106 (±2.36 × 106) CFU/gram tissue culture (p = 0.016); at the end of therapy there was no statistical difference between the two groups (p = 0.44). Wounds treated with NPWTi had a mean of 2.6 × 105 (±3 × 105) CFU/gram of tissue culture while wounds treated with NPWT had a mean of 2.79 × 106 (±3.18 × 106) CFU/gram of tissue culture (p = 0.43). The mean absolute reduction in bacteria for the NPWTi group was 10.6 × 106 bacteria per gram of tissue while there was a mean absolute increase in bacteria for the NPWT group of 28.7 × 106 bacteria per gram of tissue, therefore there was a statistically significant reduction in the absolute bioburden in those wounds treated with NPWTi (p = 0.016). ConclusionIt has long been realized that NPWT does not make its greatest impact by bioburden reduction. Other work has demonstrated that debridement alone does not reduce wound bioburden by more than 1 Log. Wounds treated with NPWTi (in this case with quarter strength bleach instillation solution) had a statistically significant reduction in bioburden, while wounds treated with NPWT had an increase in bioburden over the 7 days.

Silver and nanoparticles of silver in wound dressings: a review of efficacy and safety

Wound infections present a significant clinical challenge, impacting on patient morbidity and mortality, with significant economic implications. Silver-impregnated wound dressings have the potential to reduce both wound bioburden and healing time. The silver ion Ag+ is the active antimicrobial entity; it can interfere with thiol (-SH) groups and provoke the generation of reactive oxygen species (ROS), a major contributor to its antibacterial efficacy. Recently, silver nanoparticles have gained considerable interest in wound bioburden reduction and in anti-inflammation, as they can release Ag+ ions at a greater rate than bulk silver, by virtue of their large surface area. If released from dressings, they also have the potential to cross biological compartments. This review aims to consolidate recent findings as to the efficacy and safety of different formulations of silver used as an antiseptic agent in dressings, summarising the features of silver nanomaterials, with particular attention to the dose-dependencies for biological effects, highlighting the need for information on their uptake and potential biological effects.

Reply

Sir: We thank Dr. Hassid for his interest in our article and appreciate the comments that highlight the subsequent key advances on this topic. One goal of this article was to further expose the importance of the sessile biofilm over the free-floating planktonic model. The use of injectable soft-tissue filling agents in cosmetic medicine is relatively early in its evolution compared with other aspects of medicine that have experienced issues related to similar tissue reactions to implantable substances, and we are now beginning to understand the relationships and benefit from those before us. We agree that this fundamental understanding highlights why current culture techniques fail to identify biofilm organisms and why pyrosequencing, polymerase chain reaction, fluorescent in situ hybridization, and ultrasound sonication are essential advances that should be considered when biofilms are suspected. While we await advances in culture techniques to reach mainstream clinical practice, double antibiotic coverage improves the likelihood that patients will receive effective empiric therapy. Here, too, the risks are high with regard to consequences of delayed treatment, and effective treatment, despite an oftentimes educated empiric approach, more often trumps the practical and theoretical risks of promoting antibiotic resistance. Evidence that combination therapy may prevent resistance is limited to tuberculosis and human immunodeficiency virus, diseases synonymous with high resistance, but further research needs to elicit the best antibiotic approach against the resistance provided by biofilms in addition to avoiding the emergence of antimicrobial resistance.1 Once culture yields improve with the newer techniques discussed, antibiotic therapy deescalation should be practiced. We also agree that alternate or adjunctive approaches should be considered, such as the use of laser-assisted liquefaction and thermal/chemical bioburden reduction procedures, and may offer a promising minimally invasive option that should be investigated further. Once again, we are grateful for Dr. Hassid's comments, which emphasize the next steps in biofilm care. Alexander T. Nguyen, M.D. Rod J. Rohrich, M.D. Department of Plastic Surgery University of Texas Southwestern Medical Center Dallas, Texas Steven Fagien, M.D. Boca Raton, Fla.

P11.22 Time trend of Legionella colonization in the waterline of a hospital of Rome, Italy

P11.22 Time trend of Legionella colonization in the waterline of a hospital of Rome, Italy