The Application of Clinical and Molecular Diagnostic Techniques to Identify a Rare Haemoglobin Variant.

Haemoglobin disorders represent a heterogeneous group of inherited conditions that involve at least one genetic abnormality in one or more of the globin chains, resulting in changes in the structure, function, and/or amount of haemoglobin molecules, which are very important for their related clinical aspects. Detecting and characterizing these disorders depends primarily on laboratory methods that employ traditional approaches and, when necessary, newer methodologies essential for solving a number of diagnostic challenges. This review provides an overview of key laboratory techniques in the diagnosis of haemoglobinopathies, focusing on the challenges, advancements, and future directions in this field. Moreover, many haemoglobinopathies are benign and clinically silent, but it is not uncommon to find unexpected variants during routine laboratory tests. The present work reported a rare and clinically interesting case of identification of haemoglobin fractions in an adult man by the determination of glycated haemoglobin (HbA1c) during a routine laboratory assessment, highlighting how the correct use of laboratory data can modify and improve the patient's clinical management.

Dithiotreitol pre-treatment of synovial fluid samples improves microbiological counts in peri-prosthetic joint infection.

PURPOSE: Synovial fluid cultures of periprosthetic joint infections (PJI) may be limited by bacteria living in the fluids as biofilm-aggregates. The antibiofilm pre-treatment of synovial fluids with dithiotreitol (DTT) could improve bacterial counts and microbiological early stage diagnosis in patients with suspected PJI. METHODS: Synovial fluids collected from 57 subjects, affected by painful total hip or knee replacement, were divided into two aliquots, one pre-treated with DTT and one with normal saline. All samples were plated for microbial counts. Sensitivity of cultural examination and bacterial counts of pre-treated and control samples were then calculated and statistically compared. RESULTS: Dithiothreitol pre-treatment led to a higher number of positive samples, compared to controls (27 vs 19), leading to a statistically significant increase in the sensitivity of the microbiological count examination from 54.3 to 77.1% and in colony-forming units count from 1884 ± 2.129 CFU/mL with saline pre-treatment to 20.442 ± 19.270 with DTT pre-treatment (P = 0.02). CONCLUSIONS: To our knowledge, this is the first report showing the ability of a chemical antibiofilm pre-treatment to increase the sensitivity of microbiological examination in the synovial fluid of patients with peri-prosthetic joint infection. If confirmed by larger studies, this finding may have a significant impact on routine microbiological procedures applied to synovial fluids and brings further support to the key role of bacteria living in biofilm-formed aggregates in joint infections.

Is nanomaterial- and vancomycin-loaded polymer coating effective at preventing methicillin-resistant Staphylococcus aureus growth on titanium disks? An in vitro study.

PURPOSE: Periprosthetic joint infections induced by methicillin-resistant Staphylococcus aureus (MRSA) pose a major socioeconomic burden. Given the fact that MRSA carriers are at high risk for developing periprosthetic infections regardless of the administration of eradication treatment pre-operatively, the need for developing new prevention modalities is high. METHODS: The antibacterial and antibiofilm properties of vancomycin, Al2O3 nanowires, and TiO2 nanoparticles were evaluated in vitro using MIC and MBIC assays. MRSA biofilms were grown on titanium disks simulating orthopedic implants, and the infection prevention potential of vancomycin-, Al2O3 nanowire-, and TiO2 nanoparticle-supplemented Resomer® coating was evaluated against biofilm controls using the XTT reduction proliferation assay. RESULTS: Among the tested modalities, high- and low-dose vancomycin-loaded Resomer® coating yielded the most satisfactory metalwork protection against MRSA (median absorbance was 0.1705; [IQR = 0.1745] vs control absorbance 0.42 [IQR = 0.07]; p = 0.016; biofilm reduction was 100%; and 0.209 [IQR = 0.1295] vs control 0.42 [IQR = 0.07]; p < 0.001; biofilm reduction was 84%, respectively). On the other hand, polymer coating alone did not provide clinically meaningful biofilm growth prevention (median absorbance was 0.2585 [IQR = 0.1235] vs control 0.395 [IQR = 0.218]; p < 0.001; biofilm reduction was 62%). CONCLUSIONS: We advocate that apart from the well-established preventative measures for MRSA carriers, loading implants with bioresorbable Resomer® vancomycin-supplemented coating may decrease the incidence of early post-op surgical site infections with titanium implants. Of note, the payoff between localized toxicity and antibiofilm efficacy should be considered when loading polymers with highly concentrated antimicrobial agents.

In vitro Inhibition of Biofilm Formation on Silicon Rubber Voice Prosthesis: Α Systematic Review and Meta-Analysis.

INTRODUCTION: Biofilm formation on voice prostheses is the primary reason for their premature implant dysfunction. Multiple strategies have been proposed over the last decades to achieve inhibition of biofilm formation on these devices. The purpose of this study was to assess the results of the available in vitro biofilm inhibition modalities on silicone rubber voice prostheses. METHODS: We conducted a systematic search in PubMed, Embase, and the Cochrane Central Register of Controlled Trials databases up to February 29, 2020. A total of 33 in vitro laboratory studies investigating the efficacy of different coating methods against Candida, Staphylococcus, Streptococcus, Lactobacilli, and Rothia biofilm growth on silicone rubber medical devices were included. Subgroup analysis linked to the type of prevention modality was carried out, and quality assessment was performed with the use of the modified CONSORT tool. RESULTS: Data from 33 studies were included in qualitative analysis, of which 12 qualified for quantitative analysis. For yeast biofilm formation assessment, there was a statistically significant difference in favor of the intervention group (standardized mean difference [SMD] = -1.20; 95% confidence interval [CI] [-1.73, -0.66]; p < 0.0001). Subgroup analysis showed that combined methods (active and passive surface modification) are the most effective for biofilm inhibition in yeast (SMD = -2.53; 95% CI [-4.02, -1.03]; p = 0.00001). No statistically significant differences between intervention and control groups were shown for bacterial biofilm inhibition (SMD = -0.09; 95% CI [-0.68, 0.46]; p = 0.65), and the results from the subgroup analysis found no notable differences between the surface modification methods. After analyzing data on polymicrobial biofilms, a statistically significant difference in favor of prevention methods in comparison with the control group was detected (SMD = -2.59; 95% CI [-7.48, 2.31]; p = 0.30). CONCLUSIONS: The meta-analysis on biofilm inhibition demonstrated significant differences in favor of yeast biofilm inhibition compared to bacteria. A stronger inhibition with the application of passive or combined active and passive surface modification techniques was reported.

Is coating of titanium implants effective at preventing Staphylococcus aureus infections? A meta-analysis of animal model studies.

AIM OF THE STUDY: To assess the effects of the available coating methods against methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) biofilm development on titanium implants. METHODS: We searched the MEDLINE, Embase, and CENTRAL databases until May 18, 2019, for studies that used animal models of infections to evaluate various titanium implant coating methods to prevent S. aureus infection. Twenty-seven studies were eligible for inclusion in qualitative synthesis. Of those, twenty-three were considered in pair-wise meta-analysis. In addition, subgroup analysis of implant protection strategies relative to uncoated controls was performed, and any adverse events stemming from the coating applications were reported. Quality assessment was performed using SYRCLE's risk of bias tool for animal studies. RESULTS: Meta-analysis showed that active coating with antibiotics was favoured over uncoated controls (standardised mean differences [SMD] for MRSA and MSSA were - 2.71 [95% CI, - 4.24 to - 1.18], p = 0.0005, and - 2.5 [- 3.79 to - 1.22], p = 0.0001, respectively). Likewise, large effect sizes were demonstrated when a combination of active and conventional non-degradable passive coatings was compared with controls (SMDs for MRSA and MSSA were - 0.62 [95% CI, - 1.15 to - 0.08], p = 0.02, and - 1.93 [95% CI, - 2.87 to - 0.98], p < 0.001, respectively). DISCUSSION/CONCLUSION: As a standalone prevention method, active titanium coating with antibiotics yielded promising results against both MSSA and MRSA. Combinations between active and non-degradable passive coatings, potentially allowing for sustained antimicrobial substance release, provided consistent hardware infection protection. Thus, we recommend that future research efforts focus on combined coating modalities against S. aureus biofilm infections in the presence of titanium implants. SYSTEMATIC REVIEW REGISTRATION: CRD42019123462.

Deep Transcranial Magnetic Stimulation Affects Gut Microbiota Composition in Obesity: Results of Randomized Clinical Trial.

Growing evidence highlights the crucial role of gut microbiota in affecting different aspects of obesity. Considering the ability of deep transcranial magnetic stimulation (dTMS) to modulate the cortical excitability, the reward system, and, indirectly, the autonomic nervous system (ANS), we hypothesized a potential role of dTMS in affecting the brain-gut communication pathways, and the gut microbiota composition in obesity. In a hospital setting, 22 subjects with obesity (5 M, 17 F; 44.9 ± 2.2 years; BMI 37.5 ± 1.0 kg/m2) were randomized into three groups receiving 15 sessions (3 per week for 5 weeks) of high frequency (HF), low frequency (LF) dTMS, or sham stimulation. Fecal samples were collected at baseline and after 5 weeks of treatment. Total bacterial DNA was extracted from fecal samples using the QIAamp DNA Stool Mini Kit (Qiagen, Italy) and analyzed by a metagenomics approach (Ion Torrent Personal Genome Machine). After 5 weeks, a significant weight loss was found in HF (HF: -4.1 ± 0.8%, LF: -1.9 ± 0.8%, sham: -1.3 ± 0.6%, p = 0.042) compared to LF and sham groups, associated with a decrease in norepinephrine compared to baseline (HF: -61.5 ± 15.2%, p < 0.01; LF: -31.8 ± 17.1%, p < 0.05; sham: -35.8 ± 21.0%, p > 0.05). Furthermore, an increase in Faecalibacterium (+154.3% vs. baseline, p < 0.05) and Alistipes (+153.4% vs. baseline, p < 0.05) genera, and a significant decrease in Lactobacillus (-77.1% vs. baseline, p < 0.05) were found in HF. Faecalibacterium variations were not significant compared to baseline in the other two groups (LF: +106.6%, sham: +27.6%; p > 0.05) as well as Alistipes (LF: -54.9%, sham: -15.1%; p > 0.05) and Lactobacillus (LF: -26.0%, sham: +228.3%; p > 0.05) variations. Norepinephrine change significantly correlated with Bacteroides (r2 = 0.734; p < 0.05), Eubacterium (r2 = 0.734; p < 0.05), and Parasutterella (r2 = 0.618; p < 0.05) abundance variations in HF. In conclusion, HF dTMS treatment revealed to be effective in modulating gut microbiota composition in subjects with obesity, reversing obesity-associated microbiota variations, and promoting bacterial species representative of healthy subjects with anti-inflammatory properties.

A Journey on the Skin Microbiome: Pitfalls and Opportunities.

The human skin microbiota is essential for maintaining homeostasis and ensuring barrier functions. Over the years, the characterization of its composition and taxonomic diversity has reached outstanding goals, with more than 10 million bacterial genes collected and cataloged. Nevertheless, the study of the skin microbiota presents specific challenges that need to be addressed in study design. Benchmarking procedures and reproducible and robust analysis workflows for increasing comparability among studies are required. For various reasons and because of specific technical problems, these issues have been investigated in gut microbiota studies, but they have been largely overlooked for skin microbiota. After a short description of the skin microbiota, the review tackles methodological aspects and their pitfalls, covering NGS approaches and high throughput culture-based techniques. Recent insights into the "core" and "transient" types of skin microbiota and how the manipulation of these communities can prevent or combat skin diseases are also covered. Finally, this review includes an overview of the main dermatological diseases, the changes in the microbiota composition associated with them, and the recommended skin sampling procedures. The last section focuses on topical and oral probiotics to improve and maintain skin health, considering their possible applications for skin diseases.

Inflammatory bowel diseases, the hygiene hypothesis and the other side of the microbiota: Parasites and fungi.

This review tackles the concept of the evolutionary mismatch, in relation with the reduction of the prevalence of the so-called "dirty old friends". These formed the variegated community of parasites and microorganisms, either prokaryotic or eukaryotic, that, over long evolutionary times, co-evolved with humans and their ancestors, inhabiting their digestive tracts, and other body districts. This community of microbial symbionts and metazoan parasites is thought to have evolved a complex network of inter-independence with the host, in particular in relation with their immune stimulating capacity, and with the consequent adaptation of the host immune response to this chronic stimulation. Strictly related to this evolutionary mismatch, the hygiene hypothesis, proposed by David Strachan in 1989, foresees that the increase in the incidence of inflammatory and autoimmune disorders during the twentieth century has been caused by the reduced exposure to parasites and microorganisms, especially in industrialized countries. Among these pathologies, inflammatory bowel diseases (IBDs) occupy a prominent role. From these premises, this review summarizes current knowledge on how variations in the composition of the gut bacterial microbiota, as well as its interactions with fungal communities, influence the overall immune balance, favouring or counteracting gut inflammation in IBDs. Additionally, the effect of worm parasites, either directly on the immune balance, or indirectly, through the modulation of bacterial and fungal microbiota, will be addressed. Finally, we will review a series of studies related to the use of molecules derived from parasitic worms and fungi, which hold the potential to be developed as postbiotics for the treatment of IBDs.

Probiotics in the prevention and treatment of atopic dermatitis.

The use of probiotic supplements might change the composition of the intestinal flora of children, subsequently modulating the immune system's reactivity. The effects of probiotic administration for the prevention/treatment of allergic diseases and atopic dermatitis, in particular, are still so controversial that no definitive recommendation can be made at this stage. Differences in strain specificity, timing, and length of administration all contribute to diversifying the conclusions of this review.

Bacterial network community in fecal and endoluminal Microbiota after colonoscopy.

The gut microbiota is a complex and dynamic ecosystem with a strong influence on the host's health. Several factors can modify the gut's bacterial composition, often leading to the onset of intestinal dysbiosis. Therefore, it is essential not only to evaluate the quantitative bacterial changes occurring in the human microbiota but also to characterize relationships existing among all the microorganisms. This study aimed to evaluate the impact of bowel cleansing on the fecal microbiota network by highlighting differences between fecal microflora before and after colonoscopy, and luminal samples during colonoscopy. Fecal and luminal samples, previously analyzed by mean of Next-Generation Sequencing (NGS) for their bacterial abundance, were further processed by a method based on Artificial Neural Network (ANN) architecture. The bowel lavage had a strong effect on the intestinal microbiota network, leading to significant changes in the distribution of different bacterial hubs potentially involved in the microbiota homeostasis. Furthermore, the fecal and luminal microbiota showed a different bacterial network, characterized by distinct microbial hubs. In particular, the latter seemed to be rich in potentially pathogenic bacteria which, in physiological conditions, are counteracted by fecal microorganisms.

Flash on gut microbiome in gestational diabetes: a pilot study.

Pregnancy induces a deep modification of women's gut microbiota composition. These changes may influence hormonal and metabolic factors, increasing insulin resistance and leading to hyperglycaemia in susceptible women. Data on 29 women in pregnancy showed insignificant reductions in the Bacteroidetes/ Firmicutes ratio in women with (n. 14) and without (n. 15) gestational diabetes (GDM). Gut microbiota compositions at the genera and species level were further analysed in ten pregnant women with and ten without GDM (9 samples were excluded due to low DNA quality/quantity), showing differences in functionally specific patterns affecting host energy dietary polysaccharide metabolism pathways. According to our results, gut microbiome alteration may play a role in GDM pathogenesis through an increase of gut permeability and higher intestinal energetic balance.

Loud and silent epidemics in the third millennium: tuning-up the volume.

The media play a key role in promoting public health and influencing debate regarding health issues; however, some topics seem to generate a stronger response in the public, and this may be related to how the media construct and deliver their messages. Mass media coverage of COVID-19 epidemic has been exceptional with more than 180,000 articles published each day in 70 languages from March 8 to April 8, 2020. One may well wonder if this massive media attention ever happened in the past and if it has been finally proven to be beneficial or even just appropriate. Surgical site and implant-related infections represent a substantial part of health care-associated infections; with an estimated overall incidence of 6% post-surgical infection, approximately 18 million new surgical site infections are expected each year globally, with 5 to 10% mortality rate and an astounding economic and social cost. In the current mediatic era, orthopaedic surgeons need to refocus some of their time and energies from surgery to communication and constructive research. Only raising mediatic awareness on surgical site and implant-related infections may tune up the volume of silent epidemics to a level that can become audible by governing institutions.

Is Implant Coating With Tyrosol- and Antibiotic-loaded Hydrogel Effective in Reducing Cutibacterium (Propionibacterium) acnes Biofilm Formation? A Preliminary In Vitro Study.

BACKGROUND: Studies have suggested that Cutibacterium acnes (formerly known as Propionibacterium) is the most frequently isolated pathogen after shoulder arthroplasty. To address the burden of periprosthetic joint infections associated with this pathogen, new prevention methods are needed. Tyrosol has a promising record of effectiveness in the field of biofilm-associated infections; however, to our knowledge, it has not been tested against C. acnes thus far. QUESTIONS/PURPOSES: In this in vitro study, we asked: (1) Is tyrosol effective in inhibiting and eradicating C. acnes planktonic growth? (2) Is there synergy between tyrosol and rifampicin? (3) Is supplementation of hydrogel with tyrosol at the minimum inhibitory and subinhibitory concentrations efficacious in reducing free-floating C. acnes growth? (4) Is implant hydrogel coating (either alone or combined with tyrosol, rifampicin, or vancomycin) beneficial in reducing C. acnes biofilm formation? (5) Is the administration of soluble tyrosol an effective measure against C. acnes biofilm formation? METHODS: We assessed C. acnes planktonic growth and eradication by inspecting visually the results of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays. We also evaluated macroscopically the presence of synergy among tyrosol and rifampicin by means of the MIC checkerboard testing. Thereafter, we addressed colorimetrically the efficacy of tyrosol-loaded Defensive Antibacterial Coating (DAC®) hydrogel against the C. acnes free-floating form by means of the XTT cell proliferation reduction assay. Then, we explored photometrically the effect of hydrogel and soluble tyrosol at reducing C. acnes biofilm formation on titanium alloy disks that simulated orthopaedic implants by using the minimum biofilm inhibition concentration assay. In particular, 16 disks were sequentially allocated to each of the following testing conditions: (1) hydrogel alone; (2) tyrosol-loaded hydrogel; (3) rifampicin-supplemented hydrogel; (4) vancomycin-loaded hydrogel; and (5) soluble tyrosol. Subsequently, implants were sonicated and cell viability was evaluated in terms of the XTT assay. RESULTS: Tyrosol was effective in inhibiting C. acnes planktonic (free-floating) growth demonstrating MIC values of 63 mM (9 mg/mL) and MBC values of 250 mM (35 mg/mL). Concerning synergy assessment, the checkerboard testing revealed additivity among tyrosol and rifampicin with a fractional inhibitory concentration index of 0.56. In addition, a hydrogel coating with tyrosol at the MIC showed no difference in the inhibition of free-floating C. Acnes form over control (median absorbance [MA] for tyrosol-supplemented hydrogel versus control groups were 0.21 [interquartile range {IQR}, 0.19-0.24] versus 0.26 [IQR, 0.23-0.31], p = 0.066). Furthermore, loaded hydrogel with tyrosol at 597 mg/mL (1 M) was no more effective than control in reducing C. acnes biofilm formation (MAs for tyrosol versus control were 0.12 [IQR, 0.11-0.13] versus 0.14 [IQR, 0.12-0.16], respectively; p = 0.076). This was also the case when we considered hydrogel in conjunction with vancomycin and rifampicin (MAs for vancomycin at 2% and 5% and rifampicin at 1% versus biofilm control were 0.139 [IQR, 0.133-0.143] and 0.141 [IQR, 0.133-0.143] and 0.135 [IQR, 0.128-0.146] versus 0.142 [IQR, 0.136-0.144], correspondingly). In contrast, soluble tyrosol at 597 mg/mL (1 M) inhibited biofilm formation compared to control (MAs for tyrosol and control groups were 0.11 [IQR, 0.09-0.13] versus 0.13 [IQR, 0.12-0.14], p = 0.007). CONCLUSIONS: Although the implant coating with hydrogel (either pure or supplemented with antimicrobial agents) did not diminish C. acnes biofilm development in vitro, soluble tyrosol at 597 mg/mL (1 M) exceeded the meaningful biofilm inhibition threshold of 80%. CLINICAL RELEVANCE: The results of the current preclinical investigation did not support the use of a fast, bioresorbable hydrogel as a coating method against C. acnes biofilms. Instead, direct local administration of soluble tyrosol at high concentrations should be further tested in future animal studies.

Probiotics Streptococcus salivarius 24SMB and Streptococcus oralis 89a interfere with biofilm formation of pathogens of the upper respiratory tract.

BACKGROUND: Infections of the ears, paranasal sinuses, nose and throat are very common and represent a serious issue for the healthcare system. Bacterial biofilms have been linked to upper respiratory tract infections and antibiotic resistance, raising serious concerns regarding the therapeutic management of such infections. In this context, novel strategies able to fight biofilms may be therapeutically beneficial and offer a valid alternative to conventional antimicrobials. Biofilms consist of mixed microbial communities, which interact with other species in the surroundings and communicate through signaling molecules. These interactions may result in antagonistic effects, which can be exploited in the fight against infections in a sort of "bacteria therapy". Streptococcus salivarius and Streptococcus oralis are α-hemolytic streptococci isolated from the human pharynx of healthy individuals. Several studies on otitis-prone children demonstrated that their intranasal administration is safe and well tolerated and is able to reduce the risk of acute otitis media. The aim of this research is to assess S. salivarius 24SMB and S. oralis 89a for the ability to interfere with biofilm of typical upper respiratory tract pathogens. METHODS: To investigate if soluble substances secreted by the two streptococci could inhibit biofilm development of the selected pathogenic strains, co-cultures were performed with the use of transwell inserts. Mixed-species biofilms were also produced, in order to evaluate if the inhibition of biofilm formation might require direct contact. Biofilm production was investigated by means of a spectrophotometric assay and by confocal laser scanning microscopy. RESULTS: We observed that S. salivarius 24SMB and S. oralis 89a are able to inhibit the biofilm formation capacity of selected pathogens and even to disperse their pre-formed biofilms. Diffusible molecules secreted by the two streptococci and lowered pH of the medium revealed to be implied in the mechanisms of anti-biofilm activity. CONCLUSIONS: S. salivarius 24SMB and S. oralis 89a possess desirable characteristics as probiotic for the treatment and prevention of infections of the upper airways. However, the nature of the inhibition appear to be multifactorial and additional studies are required to get further insights.

Cost-benefit analysis of antibiofilm microbiological techniques for peri-prosthetic joint infection diagnosis.

BACKGROUND: Implant-related infections, including those of peri-prosthetic joint (PJIs), osteosynthesis and other biomaterials, are biofilm-related. Pathogen identification is considered the diagnostic benchmark; however, the presence of bacterial biofilms makes pathogen detection with traditional microbiological techniques only partially effective. To improve microbiological diagnostic accuracy, some biofilm debonding techniques have been recently proposed. Aim of this health economics assessment study was to evaluate their economic impact on hospital costs. METHODS: Direct and indirect hospital costs connected with the routine introduction of sonication and dithiothreitol treatment applied to hip and knee PJIs and of tissue cultures were examined. In particular the consequences of diagnostic inaccuracy, the opportunities, costs, and risks of each technique were calculated. RESULTS: Considering an average of five samples per patient, processed separately with traditional tissue culture with or without sonication of prosthetic components, or pooled together using the MicroDTTect device (a close system for sample collection, transport and treatment with Dithiothreitol for microbial release from biofilm), the overall mean direct cost per patient was € 397 and € 393 for sonication or MicroDTTect, respectively, compared to € 308 for traditional tissue cultures. In terms of opportunity costs, MicroDTTect was the most effective technique, allowing for a 35% or 55% reduction in time required for sample treatment, compared to tissue cultures combined or not with sonication, respectively. Pooling together direct and indirect costs associated with false positive and negative results of the different diagnostic techniques, unnecessary medical treatments and possible medical claims, MicroDTTect or sonication become increasingly cost-effective when the extra-costs, generated by diagnostic inaccuracy of traditional tissue culture, took place, respectively, in 2% or 20% or more of the patients. CONCLUSIONS: This is the first study specifically focused on the economic impact of the routine clinical use of microbiological antibiofilm sampling and processing techniques in orthopaedics. Although our results may suffer from a potential country and hospital bias, as the data collection process for direct and indirect costs is specific to each institution and country, this analysis highlights the potential economic advantage to hospitals associated with the routine introduction of antibiofilm techniques for microbiological diagnosis of PJI.

Vitamin E Phosphate Coating Stimulates Bone Deposition in Implant-related Infections in a Rat Model.

BACKGROUND: Implant-related infections are associated with impaired bone healing and osseointegration. In vitro antiadhesive and antibacterial properties and in vivo antiinflammatory effects protecting against bone loss of various formulations of vitamin E have been demonstrated in animal models. However, to the best of our knowledge, no in vivo studies have demonstrated the synergistic activity of vitamin E in preventing bacterial adhesion to orthopaedic implants, thus supporting the bone-implant integration. QUESTIONS/PURPOSES: The purpose of this study was to test whether a vitamin E phosphate coating on titanium implants may be able to reduce (1) the bacterial colonization of prosthetic implants and (2) bone resorption and osteomyelitis in a rat model of Staphylococcus aureus-induced implant-related infection. METHODS: Twelve rats were bilaterally injected in the femurs with S aureus UAMS-1-Xen40 and implanted with uncoated or vitamin E phosphate-coated titanium Kirschner wires without local or systemic antibiotic prophylaxis. Eight rats represented the uninfected control group. A few hours after surgery, two control and three infected animals died as a result of unexpected complications. With the remaining rats, we assessed the presence of bacterial contamination with qualitative bioluminescence imaging and Gram-positive staining and with quantitative bacterial count. Bone changes in terms of resorption and osteomyelitis were quantitatively analyzed through micro-CT (bone mineral density) and semiquantitatively through histologic scoring systems. RESULTS: Six weeks after implantation, we found only a mild decrease in bacterial count in coated versus uncoated implants (Ti versus controls: mean difference [MD], -3.705; 95% confidence interval [CI], -4.416 to -2.994; p < 0.001; TiVE versus controls: MD, -3.063; 95% CI, -3.672 to -2.454; p < 0.001), whereas micro-CT analysis showed a higher bone mineral density at the knee and femoral metaphysis in the vitamin E-treated group compared with uncoated implants (knee joint: MD, -11.88; 95% CI, -16.100 to -7.664; p < 0.001 and femoral metaphysis: MD, -19.87; 95% CI, -28.82 to -10.93; p < 0.001). We found decreased osteonecrosis (difference between medians, 1.5; 95% CI, 1-2; p < 0.002) in the infected group receiving the vitamin E-coated nails compared with the uncoated nails. CONCLUSIONS: These preliminary findings indicate that vitamin E phosphate implant coatings can exert a protective effect on bone deposition in a highly contaminated animal model of implant-related infection. CLINICAL RELEVANCE: The use of vitamin E coatings may open new perspectives for developing coatings that can limit septic loosening of infected implants with bacterial contamination. However, a deeper insight into the mechanism of action and the local release of vitamin E as a coating for orthopaedic implants is required to be used in clinics in the near future. Although this study cannot support the antimicrobial properties of vitamin E, promising results were obtained for bone-implant osseointegration. These preliminary results will require further in vivo investigations to optimize the host response in the presence of antibiotic prophylaxis.

One-stage exchange with antibacterial hydrogel coated implants provides similar results to two-stage revision, without the coating, for the treatment of peri-prosthetic infection.

PURPOSE: Aim of this study was to verify the hypothesis that a one-stage exchange procedure, performed with an antibiotic-loaded, fast-resorbable hydrogel coating, provides similar infection recurrence rate than a two-stage procedure without the coating, in patients affected by peri-prosthetic joint infection (PJI). METHODS: In this two-center case-control, study, 22 patients, treated with a one-stage procedure, using implants coated with an antibiotic-loaded hydrogel [defensive antibacterial coating (DAC)], were compared with 22 retrospective matched controls, treated with a two-stage revision procedure, without the coating. RESULTS: At a mean follow-up of 29.3 ± 5.0 months, two patients (9.1%) in the DAC group showed an infection recurrence, compared to three patients (13.6%) in the two-stage group. Clinical scores were similar between groups, while average hospital stay and antibiotic treatment duration were significantly reduced after one-stage, compared to two-stage (18.9 ± 2.9 versus 35.8 ± 3.4 and 23.5 ± 3.3 versus 53.7 ± 5.6 days, respectively). CONCLUSIONS: Although in a relatively limited series of patients, our data shows similar infection recurrence rate after one-stage exchange with DAC-coated implants, compared to two-stage revision without coating, with reduced overall hospitalization time and antibiotic treatment duration. These findings warrant further studies in the possible applications of antibacterial coating technologies to treat implant-related infections. LEVEL OF EVIDENCE: III.

Economic Evaluation of Antibacterial Coatings on Healthcare Costs in First Year Following Total Joint Arthroplasty.

BACKGROUND: Antibacterial coatings (ABCs) of implants have proven safe and effective to reduce postsurgical infection, but little is known about their possible economic impact on large-scale use. This study evaluated the point of economic balance, during the first year after surgery, and the potential overall annual healthcare cost savings of 3 different antibacterial technologies applied to joint arthroplasty: a dual-antibiotic-loaded bone cement (COPAL G + C), an antibacterial hydrogel coating (DAC), and a silver coating (Agluna). METHODS: The variables included in the algorithm were average cost and number of primary joint arthroplasties; average cost per patient of the ABC; incidence of periprosthetic joint infections and expected reduction using the ABCs; average cost of infection treatment and expected number of cases. RESULTS: The point of economic balance for COPAL G + C, DAC, and Agluna in the first year after surgery was reached in patient populations with an expected postsurgical infection rate of 1.5%, 2.6%, and 19.2%, respectively. If applied on a national scale, in a moderately high-risk population of patients with a 5% expected postsurgical infection rate, COPAL G + C and DAC hydrogel would provide annual direct cost savings of approximately €48,800,000 and €43,200,000 (€1220 and €1080 per patient), respectively, while the silver coating would be associated with an economic loss of approximately €136,000,000. CONCLUSION: This economic evaluation shows that ABC technologies have the potential to decrease healthcare costs primarily by decreasing the incidence of surgical site infections, provided that the technology is used in the appropriate risk class of patients.

Blood to skin recirculation of CD4+ memory T cells associates with cutaneous and systemic manifestations of psoriatic disease.

Blood to skin recirculation could play a role in the pathogenesis of psoriasis. To investigate this possibility we dissected the phenotype of circulating T cells in psoriasis patients, calculated the correlation the clinical parameters of the disease and performed a parallel bioinformatics analysis of gene expression data in psoriatic skin. We found that circulating CCR6+ CD4+ TEM and TEFF cells significantly correlated with systemic inflammation. Conversely, the percentage of CXCR3+ CD4+ TEM cells negatively correlated with the severity of the cutaneous disease. Importantly CLA+ CD4+ TCM cells expressing CCR6+ or CCR4+CXCR3+ negatively correlated with psoriasis severity suggesting recruitment to the skin compartment. This assumption was reinforced by gene expression data showing marked increase of CCR7 and CLA-encoding gene SELPLG expression in psoriatic skin and strong association of their expression. The data enlightens a role for CD4+ T cells trafficking between blood and skin in cutaneous and systemic manifestations of psoriasis.

Reliability of a multiplex PCR system for diagnosis of early and late prosthetic joint infections before and after broth enrichment.

Early microbiological diagnosis of prosthetic joint infection (PJI) is essential for successful antimicrobial treatment; however, culture has limited sensitivity, particularly in patients who had received antibiotic therapy, and the utility of molecular methods for diagnosing PJIs remains debated. We investigated the reliability of a multiplex PCR system for the microbiological diagnosis of early and late PJIs. Samples of periprosthetic tissues, synovial fluid, and prosthetic implants from 47 patients with early (n=13) or late (n=34) PJI were analyzed by conventional culture and with the multiplex-PCR Unyvero ITI® (U-ITI) cartridge system. Samples treated with dithiothreitol (DTT) and synovial fluids were spread directly on agar plates and inoculated into enrichment broths. The synovial fluids, DTT eluates and enrichment broths were processed according to the U-ITI protocol. When compared against culture as the reference method, U-ITI analysis of DTT eluates had a sensitivity of 34.2%; sensitivity of U-ITI analysis increased up to 81.6% when enrichment broths were analyzed. In particular, sensitivity was 44.4% for synovial fluids, and 41.7%, and 23.5% for DTT eluates from early and late infections, respectively. Sensitivity of analysis of enrichment broths was 83.3% for early infections, 82.3% for late infections and 77.8% for synovial fluids. Our findings seem to suggest that, when coupled with the use of broth culture, U-ITI analysis may allow for more rapid microbial identification than biochemical methods, while no advantages in time to detect microbial growth were observed. Improvements, particularly in sensitivity, are needed to make it more suitable for diagnosis of early and late PJIs.