Bacterial Bioburden Research Articles

Inter-rater and intra-rater reliability outcomes of a rapid bacteria counting system with pressure ulcer samples.

Evaluating bacterial load in pressure ulcers (PUs) is key to combat infection; therefore, using technologies to measure bacterial count can be particularly useful. A rapid bacteria counting system was recently developed and introduced to the wound care field. However, its reliability was not established. This cross-sectional study aimed to evaluate the inter-rater and intra-rater reliability of bacterial count using this rapid counting system. We took bacterial swabs from patients with category I or greater PUs to assess inter- and intra-rater reliability. An assessor swabbed the longest axis of the PU once and bacterial counts were measured using a rapid bacteria counting system. To confirm the inter-rater and intra-rater reliability, intraclass correlation coefficients (ICCs) were calculated. We took 63 and 57 pairs of bacterial counts from 13 patients with 16 category I or greater PUs to assess inter- and intra-rater reliability, respectively. Overall ICCs [95% confidence intervals (CI)] for the bacterial counts were 0.83 [0.73-0.90, p<0.001, inter-rater reliability, n=63], and 0.89 [0.82-0.94, p< 0.001, intra-rater reliability, n=57]. A high level of reliability for counting bacterial numbers in PU sites was confirmed. The results should encourage clinicians and researchers to use this type of device for the real-time assessment of wound bacterial bioburden at the patient's bedside.

Minocycline enhances the mesenchymal stromal/stem cell pro-healing phenotype in triple antimicrobial-loaded hydrogels.

Wound healing is a complex biological process that can be hindered by bacterial infection, excessive inflammation, and inadequate microvasculature. In this study, we develop a new formulation of poly(ethylene glycol) diacrylate and thiolated gelatin poly(ethylene glycol) crosslinked hydrogels loaded with minocycline, vancomycin, linezolid, and mesenchymal stromal/stem cells that induces a favorable wound healing phenotype in mesenchymal stromal/stem cells and prevents bacterial bioburden on the hydrogel. This combinatorial approach to biomaterial development has the potential to impact wound healing for contaminated full thickness cutaneous wounds.

A Prospective Randomized Controlled Two-Arm Clinical Study Evaluating the Efficacy of a Bioelectric Dressing System for Blister Management in US Army Ranger Recruits.

This study focused on a clinically relevant healthcare problem in the military: acute soft tissue wounds, or blisters. The trial was a prospective, controlled, randomized two-arm study evaluating the efficacy of a bioelectric dressing, Procellera®, applied topically two to three times per week for 2 weeks to blisters developed in Ranger trainees during training at Fort Benning, Georgia. A total of 80 US Army Ranger recruits with blister wounds below the knee were randomly assigned to one of two treatment groups (n = 40/group). The primary goal was to assess the clinical efficacy (rate of healing) of administered Procellera in conjunction with the standard-of-care (SOC) treatment, moleskin and Tegaderm ®, on the healing rate of blisters compared with the SOC treatment alone. The secondary end points for efficacy were the quantities of wound fluid biomarkers and bacterial bioburden. The tertiary end point was assessment of pain in the treatment group compared with that of the control group during the 2-week study. The results showed no statistical difference between the SOC and SOC+Procellera groups in wound healing and pain. Wound fluid was reported for 24 participants (64.9%) in the SOC group and 21 participants (56.8%) in SOC+Procellera group at the baseline measurement (ρ = .475); however, the wounds were devoid of fluid on follow-up visits. The mild nature of the wounds in this study was apparent by the low pain scores at the beginning of the study, which disappeared by the follow-up visits. The average wound sizes were 2.2cm2 and 1.5cm2 for the SOC and SOC+Procellera groups, respectively. This trial protocol should be conducted on open softtissue wounds in severe heat. To our knowledge, this is the first clinical study conducted within the US Army Rangers training doctrine.

Autolytic debridement and management of bacterial load with an occlusive hydroactive deressing impregnated with polyhexamethylene biguanide.

Background:Debridement and control of bacterial load are key-points of wound care. The aim of this study is to evaluate the effectiveness of autolytic debridement and management of bacterial load (bioburden) of an occlusive hydro-active dressing impregnated with polyhexamethylene biguanide (PHMB).Methods:We used an occlusive dressing of hydro-active for leg ulcers’ treatment (TenderWet-plus® – Hartmann). Inclusion criteria were: presence of a fibrinous ulcer with multiple etiopathogenesis, in absence of clinical infection, no hypersecretion and diameter within 5 cm. Swab for bacterial bioburden control were made at start of the study, after 3 and 7 days. We made also a measurement of the amount of granulation tissue and of pain with VAS scale; bacterial bioburden control inside the dressing was made too.Results:28 leg ulcers were treated (12 venous, 5 diabetic, 8 thraumatic, 3 mixed) in 25 patients. The ulcer has been completely covered with fibrin in almost all cases and the bacterial load was represented mainly by Staphylococcus aureus (80% of the cases) with a load within 10.000UFC/plate in 81,5% of the cases. Control at 3 and 7 days have shown the appearance of granulaton tissue up to 67,8% of the wound surface. Bacterial bioburden (load) remained constant in 50% of the cases, decreased in 15%, increased in 35% of the cases.Conclusion:TenderWet-plus® has proven to be effective and quick in autolytic debridement and at the same time be able to handle the bacterial load in most cases. It can then be used for home treatment. (www.actabiomedica.it)

The impact of lens care solutions on corneal epithelial changes during daily silicone hydrogel contact lens wear as measured by in vivo confocal microscopy.

To assess corneal epithelial microstructure via confocal microscopy and determine if cellular changes are associated with lens care solutions during daily wear of silicone hydrogel contact lenses. Corneal in vivo confocal microscopy with the Nidek ConfoScan4 was performed at baseline and after 5 months of lotrafilcon A daily contact lens wear. Enrolled participants were randomized to use either a polyhexamethylene biguanide (PHMB) preserved multipurpose care solution (MPS) or a peroxide based solution system. Lens and storage case bioburden were assessed with aerobic culture methods. Univariate and multivariable analyses were done to evaluate the association between solution use, or solution-related clinical covariates, and morphologic differences (hyper-reflectivity) in the superficial epithelial cells and epithelial basal cell density. Data on 139 participants were available for analysis of superficial epithelial cells while data on 92 participants were available for epithelial basal cell density. Five months after randomization to the solution groups, 33% of participants had visible hyper-reflective cells. More participants using MPS had ≥1 hyper-reflective cells compared to peroxide users at 5 months (44% vs. 22%; p=0.006). Similarly at 5 months, more participants with solution-induced corneal staining (SICS) had ≥1 hyper-reflective cells compared to non-SICS participants (57% vs. 29%; p=0.010). The adjusted odds ratios (ORs) for risk of presenting with hyper-reflective cells in MPS users or SICS participants was 2.7 (95% CI; 1.27-5.65) and 3.4 (95% CI; 1.29-8.97), respectively. Basal cell density decreased by over 350 cells/mm2 over time (about 6%) in participants who had substantial bioburden on their lenses or in their storage case. The confocal microscope can detect epithelial cellular changes in vivo during contact lens wear. Hyper-reflective superficial epithelial cells are associated with a PHMB preserved solution and decreases in basal epithelial cell density may be associated with bacterial bioburden.

Evaluation of antibiotic pressurized pulse lavage for contaminated retromuscular abdominal wall reconstruction.

Despite patient risk factors such as diabetes and obesity, contamination during surgery remains a significant cause of infections and subsequent wound morbidity. Pressurized pulse lavage (PPL) has been utilized as a method to reduce bacterial bioburden with promising results in many fields. Although existing methods of lavage have been utilized during abdominal operations, no studies have examined the use of PPL during complex hernia repair. Patients undergoing abdominal wall reconstruction (AWR) in clean-contaminated or contaminated fields with antibiotic PPL, from January 2012 to May 2013, were prospectively evaluated. Primary outcome measures studied were conversion of retrorectus space culture from positive to negative after PPL and 30-day surgical site infection (SSI) rate. A total of 56 patients underwent AWR, with 44 patients (78.6%) having clean-contaminated fields and 12 patients (21.4%) having contaminated ones. Twenty-two patients (39.3%) had positive pre-PPL cultures, 18 of which (81.8%) converted to negative cultures after PPL. Eleven patients (19.6%) developed SSIs. Those with persistently positive cultures after PPL had the highest rate of SSI, where two out of four patients (50.0%) developed an SSI. Contrastingly, only 5 of 18 patients (27.8%) who converted from a positive to negative culture after PPL developed an SSI. Our findings demonstrate that antibiotic PPL is an effective method to reduce bacterial bioburden during AWR in clean-contaminated and contaminated fields. While complete conversion and eradication of SSI were not achieved, we believe that PPL may be a useful adjunct to standard operative asepsis in preventing prosthetic contamination during contaminated AWR.

Bioaerosols in the Barcelona subway system

Subway systems worldwide transport more than 100 million people daily; therefore, air quality on station platforms and inside trains is an important urban air pollution issue. We examined the microbiological composition and abundance in space and time of bioaerosols collected in the Barcelona subway system during a cold period. Quantitative PCR was used to quantify total bacteria, Aspergillus fumigatus, influenza A and B, and rhinoviruses. Multitag 454 pyrosequencing of the 16S rRNA gene was used to assess bacterial community composition and biodiversity. The results showed low bioaerosol concentrations regarding the targeted microorganisms, although the bacterial bioburden was rather high (104 bacteria/m3 ). Airborne bacterial communities presented a high degree of overlap among the different subway environments sampled (inside trains, platforms, and lobbies) and were dominated by a few widespread taxa, with Methylobacterium being the most abundant genus. Human-related microbiota in sequence dataset and ascribed to potentially pathogenic bacteria were found in low proportion (maximum values below 2% of sequence readings) and evenly detected. Hence, no important biological exposure marker was detected in any of the sampled environments. Overall, we found that commuters are not the main source of bioaerosols in the Barcelona subway system.

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.

The Use of ATPase Monitoring to Determine Endoscope Bioburden and Assure Satisfactory Manual Cleaning

Introduction: Recent multidrug resistant organism outbreaks linked to endoscopy have prompted re-examination of endoscope reprocessing. The steps of reprocessing include manual cleaning, automatic reprocessing, and drying. The manual cleaning phase is the most vulnerable to contamination as it is prone to human error. Many centers have turned to culturing instruments to assure that their instruments have been successfully disinfected. We report applying the “ATPase” assay to our reprocessing method. This technology is routinely used in hospitals to assure cleanliness of work surfaces but it is sparingly used in the field of endoscopy. The system provides real-time, quantitative data by utilizing bioluminescence of adenosine triphosphate (ATP) as an indirect measure of bacterial presence or bioburden. There is no standardized method of ATPase use in endoscopy. Methods: Data was collected from patient used colonoscopes and gastroscopes during a 3 month trial period. Data was then collected over the following 12 months after the reprocessing method was reformed. ATP samples were obtained after intruments were manually cleaned, just before they were placed into an automatic reprocessor. A collection technique proposed by a leading investogator in the field was used to obtain channel and surface samples. The 3M™ Clean-Trace ATP Surface Test was used to measure the presence of ATP. A threshold of 200 relative light units (RLU) was used to determine if endoscopes “passed”. Instruments were re-cleaned if they exceeded 200 RLU. Results: A total of 618 tests were performed (310 gastroscopes) between March 2013 and May 2014. Surface cleaning was effective in 98.5% of gastroscopes and 96.9% of colonoscopes. Samples obtained from the biopsy channel were quite different with 95.4% of colonoscopes passing and only 64.2% of gastroscopes passing. The manual cleaning process was then modified and the enzymatic detergent used to flush endoscope channels was changed. During the 12 month observation period, over 90% of all gastroscopes and colonoscopes passed. Conclusion: Initial results showed that gastroscopes were more difficult to clean, likely due to biofilm on complex structural elements and increased mucus encountered during EGD. After modifying the reprocessing technique, the RLU values for gastroscopes significantly improved. We provide this data to aid in the standardization of the ATPase assay sampling method as a routine method of manual cleaning phase monitoring at endoscopy centers worldwide.

Incorporating Cutaneous and Wound Bacterial Bioburden Biomarkers into Clinical Research: A Review of Best Practices.

To provide information about initiating interdisciplinary research related to microbiomes and their role in human immunity, disease, and metabolic processes. This continuing education activity is intended for physicians and nurses with an interest in skin and wound care. After participating in this educational activity, the participant should be better able to:1. Describe techniques to identify and characterize bacterial bioburden.2. Identify optimal collection, transport, and storage of samples. The purpose of this review is to provide a roadmap for clinical scientists interested in integrating bacterial bioburden (BB) biomarkers into the next generation of cutaneous or wound disease research studies. Complex relationships exist between humans and their microbiome. Until now, clinical scientists have been limited in fully characterizing relationships between humans and their microbiome. Recent technological innovations, such as next-generation DNA sequencing, also known as deep sequencing or pyrosequencing, have enhanced clinicians' capacity to identify, characterize, and elucidate the role of BB (ie, bacterial load, diversity, pathogenicity) in human immunity, disease, and metabolic processes. The understanding of common terminology, intervening variables that influence BB, limitations of next-generation DNA sequencing, and specimen selection, collection, transport, and storage practices are needed to support interdisciplinary communication, research design, and integrity of the specimen. This review serves as a primer for building foundational knowledge in microbiome research, which will aid clinical scientists with initiating interdisciplinary communication necessary for scientific team building.

Incorporating Cutaneous and Wound Bacterial Bioburden Biomarkers into Clinical Research: A Review of Best Practices.

Incorporating Cutaneous and Wound Bacterial Bioburden Biomarkers into Clinical Research: A Review of Best Practices.

Nondermal irritating hyperosmotic nanoemulsions reduce treatment times in a contamination model of wound healing.

Increased microbial burden within the wound often complicates wound healing and may lead to subsequent infection or delayed healing. Here, we investigate a novel topical for addressing wound contamination that utilizes hyperosmotic saccharides with a cell membrane disrupting emulsion. These hyperosmotic nanoemulsions (HNE) were administered topically in a full-thickness biopsy model of wound healing. Results show that HNE were well tolerated in noninfected animals with no indications of dermal irritation or acute toxicity. Additionally, HNE was able to reduce bacterial bioburden (Escherichia coli and Enterococcus faecalis) levels by 3 logs within 24h when wounds were inoculated with 5×10(6) total CFU. These bactericidal values were similar to wounds treated with silver sulfadiazine. Wound closure showed HNE wounds closed in 7.6 ± 0.2 days while SSD and control required 10.2 ± 0.4 and 10.4 ± 0.3 days, respectively. HNE maintained a moist wound environment, were well debrided, and exhibited improved hemostatic response. Further histological examination revealed enhanced granulation tissue as compared to silver sulfadiazine and control cohorts. These results were corroborated with 3D topographical imprints of the wounds at day 14 which qualitatively showed a smoother surface. In contrast, silver sulfadiazine appeared to delay wound closure. Finally, dermal sensitization and irritation studies conducted in guinea pig and rabbits did not reveal any acute dermal side effects from HNE exposure. The cumulative data indicates nonantibiotic-based HNEs may be a promising topical treatment for the management of contaminated wounds.

Assessment of wound bio-burden and prevalence of multi-drug resistant bacteria during open wound management.

To describe the bacterial bio-burden of open-treated wounds and make comparisons with bite wounds. Retrospective multicentre study. Microbial culture between 2011 and 2013 from open-treated wounds in dogs and cats (initiation of therapy n=88, follow-up n=52) were compared to those from bite wounds (n=184). Bacteria were identified and tested for antibiotic susceptibility by two accredited laboratories. In total, 77/88 (88%) of open-treated wounds yielded positive bacterial cultures at the beginning of treatment, decreasing to 27/52 (52%) during treatment. Upon initial evaluation, 42/88 (48 %) of open-treated wounds were considered infected with multi-drug-resistant bacteria, with a drop to 22/52 (41%) during therapy. Bite wounds yielded fewer positive cultures 88/184 (48%) with only 11/182 (6%) being affected by multi-drug-resistant bacteria. Bacteria found most commonly in open-treated wounds were Enterococcus subspecies, Escherichia coli, Staphylococcus pseudintermedius and Pseudomonas aeruginosa. The bacterial populations of open-treated wounds differed markedly from the bite wounds. The high incidence of multi-drug-resistant strains in open wounds highlights the need for alternatives to antibiotics.

Comparison of the effect of negative pressure wound therapy with and without installation of polyhexanide on the bacterial kinetic in chronic wounds

Abstract Background Negative pressure wound therapy (NPWT) has established successfully as a treatment option for acceleration of wound healing in a broad range of clinical indications. Systematic research investigating the bacterial kinetics on wounds is lacking and no studies are available comparing the microbiological difference of repeated instillation of polyhexanide (PHMB) against continuous NPWT without instillation of an antiseptic. The aim of this study was to investigate the bacterial bio-burden on wounds and to measure the bacterial kinetic during application of NPWT with and without intermitted instillation of 0.02% PHMB. Methods A cohort of 18 patients with chronic (n = 16) and acute (n = 2) wounds was treated either with NPWT alone or with additional intermitted instillation of 0.02% PHMB. Wound healing and bacterial load were assessed at every dressing change. All wounds were closed by split-thickness skin grafts or local Reverdin flaps. According to the manufacturer of the investigated NPWT system (V.A.C. therapy unit, Kinetic Concepts Inc. KCI) wounds were filled with a polyurethane sponge (pore size 0.4–0.6 mm) and occluded with a polyurethane foil (KCI Inc., USA). The NPWT-device was connected to the wound and operated at 100 mm Hg sub-atmospheric pressure utilizing an alternating pressure cycle of 5 min of suction followed by 2 min pause. The automated intermittent instillation lasted for 4–20 s, the exposure time was 20 min. After 60 min of NPWT, the instillation was started again. Results Seven split-thickness skin grafts, 3 Reverdin-flaps and one combined closure (Reverdin + split-thickness skin grafts) exhibited excellent wound healing after successful transplantation 4 weeks after intervention. The quality of wound granulation was excellent in all wounds, regardless of NPWT application with or without instillation of 0.02% PHMB. The bacterial spectrum remained mostly unchanged after treatment and had no influence on the outcome. Conclusion It was demonstrated that management of infected wounds with NPWT, with or without instillation of 0.02% PHMB, did not reduce the number of bacteria on wounds. Bacteria proliferate below a NPWT dressing and increase in numbers. Independently of bacterial kinetics, all wounds showed excellent granulation and healed with no complications. This observation challenges the concept that bacterial bioburden correlates with impaired wound healing.

Wound Healing Society 2015 update on guidelines for pressure ulcers.

Wound Healing Society 2015 update on guidelines for pressure ulcers.

Detection of Biofilm in Wounds as an Early Indicator for Risk for Tissue Infection and Wound Chronicity.

Wounds are dynamic environments in which dead tissue, exudate, and the bacterial bioburden interact in a complex manner among themselves and with the tissue of the host. Bacteria organize into biofilms, reducing their susceptibility to elimination by the host immune response and antimicrobials. Early detection of biofilms in wounds is crucial to successful chronic wound management; and although many techniques have developed to identify planktonic counterparts in viable wounds, few have been able to quickly and accurately identify bacterial biofilms. Future studies are needed to find means of identifying and monitoring biofilm colonization at the bedside to permit timely initiation of treatment. In this review, we examine some promising new technologies that hope to identify and quantify the process of biofilm formation in chronic wounds.

Evaluation and quantitative microbial risk assessment of a unique antimicrobial agent for hospital surface treatment

It is generally agreed that contaminated hospital surfaces play a role in the transmission of hospital-acquired infections (HAIs). The ability of an antimicrobial agent, engineered at Emory University, to reduce bacterial bioburden on hospital surfaces was examined. A quantitative microbial risk assessment was also conducted to quantify the potential reduction of human health risks associated with application of this antimicrobial product. A 1-arm, prospective observational study was conducted. High-frequency contact surfaces within 18 hospital patient rooms were sampled in between patient use. Negative binomial regression with repeated measures was used to examine log CFU/100cm(2) reductions in total, gram-negative, and Staphylococcus aureus microorganisms. Standard risk assessment methods were used. Multivariate regression demonstrated significant reductions in gram-negative (P<.0001) and S aureus (P=.009) bacteria with increasing patient turnover. No reduction was observed in total bacteria (P=.93). Infection risks were reduced by 4 and 3 logs for gram-positive and gram-negative bacteria, respectively. These risk reductions, along with HAI survey studies, suggest that application of this antimicrobial product could prevent as many as 5%-10% of HAIs. This study was the first evaluation of a distinctive antimicrobial agent for hospital surface treatment. The findings provide support for the utility of an antimicrobial product in potentially reducing HAI transmission from contaminated environment surfaces.

Reviewing the benefits and harm of NPWT in the management of closed surgical incisions.

The use of negative pressure wound therapy (NPWT) for the treatment of open traumatic, non-traumatic, chronic wounds and coverage over skin grafts has increased in popularity over the past decade. Although the exact mechanism of the action of NPWT on wound healing is still an active area of research, evidence propose it is achieved by removing oedema, increasing blood circulation, reducing bacterial bio-burden, providing a moist wound-healing environment, and increasing granulation tissue formation. In recent years, there has been an emerging body of literature describing a novel application of NPWT on closed surgical wounds, especially on closed orthopaedic incisional (COI) wounds. It has been suggested that applying NPWT to a COI may decrease the incidence of surgical wound-healing complications, such as hematoma, seroma, infection, or dehiscence, and hasten the healing of the incision. This review will evaluate the potential effect on the reduction of postoperative closed wound complications and examine the benefits and harm of NPWT in the management of COI.

Immunomodulatory Peptide IDR-1018 Decreases Implant Infection and Preserves Osseointegration.

Innate defense regulator peptide-1018 (IDR-1018) is a 12-amino acid, synthetic, immunomodulatory host defense peptide that can reduce soft tissue infections and is less likely to induce bacterial resistance than conventional antibiotics. However, IDRs have not been tested on orthopaedic infections and the immunomodulatory effects of IDR-1018 have only been characterized in response to lipopolysacharide, which is exclusively produced by Gram-negative bacteria. We sought (1) to more fully characterize the immunomodulatory effects of IDR-1018, especially in response to Staphylococcus aureus; and (2) to determine whether IDR-1018 decreases S aureus infection of orthopaedic implants in mice and thereby protects the implants from failure to osseointegrate. In vitro effects of IDR-1018 on S aureus were assessed by determining minimum inhibitory concentrations in bacterial broth without and with supplementation of physiologic ion levels. In vitro effects of IDR-1018 on macrophages were determined by measuring production of monocyte chemoattractant protein-1 (MCP-1) and proinflammatory cytokines by enzyme-linked immunosorbent assay. In vivo effects of IDR-1018 were determined in a murine model of S aureus implant infection by quantitating bacterial burden, macrophage recruitment, MCP-1, proinflammatory cytokines, and osseointegration in nine mice per group on Day 1 postimplantation and 20 mice per group on Day 15 postimplantation. IDR-1018 demonstrated antimicrobial activity by directly killing S aureus even in the presence of physiologic ion levels, increasing recruitment of macrophages to the site of infections by 40% (p = 0.036) and accelerating S aureus clearance in vivo (p = 0.008) with a 2.6-fold decrease in bacterial bioburden on Day 7 postimplantation. In vitro immunomodulatory activity of IDR-1018 included inducing production of MCP-1 in the absence of other inflammatory stimuli and to potently blunt excess production of proinflammatory cytokines and MCP-1 induced by lipopolysaccharide. Higher concentrations of IDR-1018 were required to blunt production of proinflammatory cytokines and MCP-1 in the presence S aureus. The largest in vivo immunomodulatory effect of IDR-1018 was to reduce tumor necrosis factor-α levels induced by S aureus by 60% (p = 0.006). Most importantly, IDR-1018 reduced S aureus-induced failures of osseointegration by threefold (p = 0.022) and increased osseointegration as measured by ultimate force (5.4-fold, p = 0.033) and average stiffness (4.3-fold, p = 0.049). IDR-1018 is potentially useful to reduce orthopaedic infections by directly killing bacteria and by recruiting macrophages to the infection site. These findings make IDR-1018 an attractive candidate to explore in larger animal models to ascertain whether its effects in our in vitro and mouse experiments can be replicated in more clinically relevant settings.

A DNA dot hybridization model for assessment of bacterial bioburden in orthokeratology lens storage cases.

The aim of this study was to evaluate a DNA dot hybridization assay (DHA) for assessing bacterial bioburden in orthokeratology lens (OK) storage cases. Forty-one OK wearers participated in this study. The dot hybridization assay was used to assess the bacterial bioburden of OK after removal and 6-hour soaking in a storage case. Signals of the DHA were standardized after gray image transformation. The correlations between the hybridization intensities of three universal bacteria probes (BP1, BP2, and BP3) and bacterial bioburden determined by culture (colony forming units per milliliter) was analyzed by Pearson's correlation coefficient and receiver operating characteristic plots. In addition, three genus-specific probes for Pseudomonas, Acinetobacter, and Klebsiella were used to detect potentially hazardous bacterial contamination regardless of bacterial viability status. Among the three universal probes, there were good correlations between probe BP2 (r2 = 0.31, P = 9.5 × 10(-5)) and probe BP3 (r2 = 0.35, P = 3.1 × 10(-5)) with bacterial bioburden, but no correlation was found between probe BP1 and bacterial bioburden (r2 = 0.04, P = 0.11). In 41 samples, one was Pseudomonas-positive by both DHA and culture, while 10 were Pseudomonas-positive by DHA but negative by culture. Furthermore, nine samples tested positive for Acinetobacter (n = 7) and Klebsiella (n = 2) by DHA only. The dot hybridization assay provides a novel way to assess the bacterial bioburden of OK storage cases. Lens care quality can be assessed with universal bacteria probes, while potentially hazardous bacterial contamination can be traced with genus-specific probes.