Effectiveness of a polyhexamethylene biguanide-containing wound cleansing solution using experimental biofilm models.

OBJECTIVE: Antiseptics are widely used in wound management to prevent or treat wound infections, and have been shown to have antibiofilm efficacy. The objective of this study was to assess the effectiveness of a polyhexamethylene biguanide (PHMB)-containing wound cleansing and irrigation solution on model biofilm of pathogens known to cause wound infections compared with a number of other antimicrobial wound cleansing and irrigation solutions. METHOD: Staphylococcus aureus and Pseudomonas aeruginosa single-species biofilms were cultured using microtitre plate and Centers for Disease Control and Prevention (CDC) biofilm reactor methods. Following a 24-hour incubation period, the biofilms were rinsed to remove planktonic microorganisms and then challenged with wound cleansing and irrigation solutions. Following incubation of the biofilms with a variety of concentrations of the test solutions (50%, 75% or 100%) for 20, 30, 40, 50 or 60 minutes, remaining viable organisms from the treated biofilms were quantified. RESULTS: The six antimicrobial wound cleansing and irrigation solutions used were all effective in eradicating Staphylococcus aureus biofilm bacteria in both test models. However, the results were more variable for the more tolerant Pseudomonas aeruginosa biofilm. Only one of the six solutions (sea salt and oxychlorite/NaOCl-containing solution) was able to eradicate Pseudomonas aeruginosa biofilm using the microtitre plate assay. Of the six solutions, three (a solution containing PHMB and poloxamer 188 surfactant, a solution containing hypochlorous acid (HOCl) and a solution containing NaOCl/HOCl) showed increasing levels of eradication of Pseudomonas aeruginosa biofilm microorganisms with increasing concentration and exposure time. Using the CDC biofilm reactor model, all six cleansing and irrigation solutions, except for the solution containing HOCl, were able to eradicate Pseudomonas aeruginosa biofilms such that no viable microorganisms were recovered. CONCLUSION: This study demonstrated that a PHMB-containing wound cleansing and irrigation solution was as effective as other antimicrobial wound irrigation solutions for antibiofilm efficacy. Together with the low toxicity, good safety profile and absence of any reported acquisition of bacterial resistance to PHMB, the antibiofilm effectiveness data support the alignment of this cleansing and irrigation solution with antimicrobial stewardship (AMS) strategies.

Efficacy of quaternary ammonium salt-based disinfectant or chelated copper-zinc footbath solution in the treatment of digital dermatitis on one research dairy farm in Taiwan.

BACKGROUND: Footbaths can be used to manage digital dermatitis (DD), a common cause of lameness in dairy cattle. Copper sulfate and chelated copper-zinc (CZS) solutions in footbaths are potentially harmful to the environment. HYPOTHESIS/OBJECTIVES: To determine if a quaternary ammonium salt-based disinfectant (QASD) footbath is as effective as a chelated CZS solution in controlling DD in dairy cows. ANIMALS: Fifty-one lactating Holstein cows were randomly assigned to one of two treatment groups, with DD status based on the M-stage scoring system and locomotion score balanced between treatment groups. MATERIALS AND METHODS: The groups were treated with a 1% QASD or a 2.5% chelated CZS. Footbaths were performed once per week for 15 weeks. Logistic regression was used to analyse clinical improvement. All cows received appropriate medical treatment for DD and other hoof diseases. RESULTS: Clinical improvement rates were 67% in the QASD group and 38% in the CZS group (p = 0.03). Logistic regression analysis showed that the odds (95% confidence interval) for clinical improvement rate in the CZS group were 0.30 (0.095-0.948) times that of the QASD group (p = 0.04). The M0 score in the QASD and CZS groups increased significantly (p < 0.05) at the end of the 15 week study period. In the QASD group, the proportion of M2, M3 and M4 scores were significantly decreased (p < 0.05). CONCLUSION AND CLINICAL RELEVANCE: Over a 15 week period, QASD for footbathing was associated with a lower prevalence of active DD lesions than when using CZS.

Electrolysed oxidising water as a multi-purpose biocide in dental healthcare-A scoping review.

OBJECTIVES: The objective of this scoping review was to map evidence of electrolysed oxidising water (EOW) as a biocide for dental applications of relevance to older people and identify research gaps. BACKGROUND: EOW is an emerging, "green," and cost-effective biocide. There are no reviews on the landscape of EOW research as either an antiseptic or disinfectant in dental healthcare or its suitability for the oral healthcare of older people. MATERIALS AND METHODS: The review follows the PRISMA Extension for Scoping Reviews (PRISMA-ScR) guidelines. Database searches (Google Scholar, PubMed, Web of Science, Ovid, Scopus and Science Direct) were undertaken using MESH terms and Boolean operators with no date restrictions, to identify full-text, original reports published in English-language peer-reviewed journals. RESULTS: The search yielded 114 papers that met the inclusion/exclusion criteria. Dental applications of EOW include its use as an endodontic irrigant (39%); mouth rinse/surgical irrigant (21%); disinfectant for dental unit water lines (19%) and dental biomaterials (17%); and for antimicrobial efficacy, effects on oral tissues and on dental material properties. Most studies (83%) evaluated a single EOW formulation (acidic, moderately acidic or neutral) that was either generated at 'point-of-use' (POU; 72%), bottled ('ready-to-use', RTU; 24%) or from unspecified (3%) sources. Six reports evaluated storage-related parameters and 25 evaluated clinical applications; 89 were in vitro studies and one investigated the cost-effectiveness of POU EOW. CONCLUSIONS: Neutral-pH, EOW is effective as an antimicrobial agent without deleterious effects on oral tissues. However, research on the impact of storage conditions, anti-Candida biofilm efficacy and mechanism of action against yeasts, long-term effects on denture materials and cost-effectiveness is required to establish the suitability of EOW as a multipurpose biocide for dental healthcare, including infection-control requirements relating to older people.

Effect of Dentin-Disinfection Chemicals on Shear Bond Strength and Microhardness of Resin-Infiltrated Human Dentin in Different Adhesive Protocols.

Background and Objectives: Bacteria and its remnants beneath the restorations predispose the tooth to secondary caries and pulpal pathology. Hence, various chemical antibacterial agents are suggested to disinfect the prepared tooth structure before the definitive restorative procedure. This study aimed to investigate the effects of chemical disinfectant solutions on the micro-shear bond strength (µSBS) and microhardness of total-etch and self-etch resin-infiltrated human dentin. Materials and Methods: 100 caries-free intact permanent third molar teeth were vertically sectioned into the buccal and lingual half. All these specimens were mounted on acrylic resin and underlying dentin surfaces were exposed by grinding. Samples were randomly divided into five groups [n = 20] following total-etch and self-etch adhesive protocol. Teeth samples were divided according to surface treatment, as Group I (Control-CNT), Group II (2% chlorhexidine-CHX), Group III (5.25% sodium hypochlorite-NaOCl), Group IV (17% ethylenediaminetetraacetate acid­EDTA) and Group V (10% povidone iodine-PVI). A randomly selected 10 samples from each subgroup were used for µSBS and microhardness tests. After surface treatment and bonding procedure, nono-hybrid composite cylinders with a 3-mm diameter and 2-mm height were directly cured over the dentin substrate. The samples for µSBS were subjected to 5000 thermocycles and tested using a universal testing machine. Microhardness was assessed using a micro-indenter instrument, data were statistically analyzed using a one-way analysis of variance and Tukey HSD tests at p < 0.05. Results: Amongst the chemical disinfectant assessed, 2% CHX did not affect µSBS and produced a marginal reduction in dentin microhardness compared to the control group. The 5.25% NaOCl and 17% EDTA significantly compromised the microhardness of the dentin substrate. Meanwhile, 10% PVI surface treatment resulted in a substantial reduction in µSBS between composite and dentin. Conclusions: CHX with preservation of bonding to dentin and insignificant negative effect on dentin microhardness is a safe option for tooth disinfection.

Wound cleansing for treating venous leg ulcers.

BACKGROUND: Leg ulcers are open skin wounds that occur below the knee but above the foot. The majority of leg ulcers are venous in origin, occurring as a result of venous insufficiency, where the flow of blood through the veins is impaired; they commonly arise due to blood clots and varicose veins. Compression therapy, using bandages or stockings, is the primary treatment for venous leg ulcers. Wound cleansing can be used to remove surface contaminants, bacteria, dead tissue and excess wound fluid from the wound bed and surrounding skin, however, there is uncertainty regarding the effectiveness of cleansing and the best method or solution to use. OBJECTIVES: To assess the effects of wound cleansing, wound cleansing solutions and wound cleansing techniques for treating venous leg ulcers. SEARCH METHODS: In September 2019 we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting. SELECTION CRITERIA: We considered randomised controlled trials (RCTs) comparing wound cleansing with no wound cleansing, or RCTs comparing different wound cleansing solutions, or different wound cleansing techniques. DATA COLLECTION AND ANALYSIS: We screened studies for their appropriateness for inclusion, assessed their risk of bias using the Cochrane 'Risk of bias' tool, and used GRADE methodology to determine the certainty of evidence. Two review authors undertook these tasks independently, using predetermined criteria. We contacted study authors for missing data where possible. MAIN RESULTS: We included four studies with a total of 254 participants. All studies included comparisons between different types of cleansing solutions, and three of these reported our primary outcomes of complete wound healing or change in ulcer size over time, or both. Two studies reported the secondary outcome, pain. One study (27 participants), which compared polyhexamethylene biguanide (PHMB) solution with saline solution for cleansing venous leg ulcers, did not report any of the review's primary or secondary outcomes. We did not identify any studies that compared cleansing with no cleansing, or that explored comparisons between different cleansing techniques. One study (61 participants) compared aqueous oxygen peroxide with sterile water. We are uncertain whether aqueous oxygen peroxide makes any difference to the number of wounds completely healed after 12 months of follow-up (risk ratio (RR) 1.88, 95% confidence interval (CI) 1.10 to 3.20). Similarly, we are uncertain whether aqueous oxygen peroxide makes any difference to change in ulcer size after eight weeks of follow-up (mean difference (MD) -1.38 cm2, 95% CI -4.35 to 1.59 cm2). Finally, we are uncertain whether aqueous oxygen peroxide makes any difference to pain reduction, assessed after eight weeks of follow-up using a 0 to 100 pain rating, (MD 3.80, 95% CI -10.83 to 18.43). The evidence for these outcomes is of very low certainty (we downgraded for study limitations and imprecision; for the pain outcome we also downgraded for indirectness). Another study (40 participants) compared propyl betaine and polihexanide with a saline solution. The authors did not present the raw data in the study report so we were unable to conduct independent statistical analysis of the data. We are uncertain whether propyl betaine and polihexanide make any difference to the number of wounds completely healed, change in ulcer size over time, or wound pain reduction. The evidence is of very low certainty (we downgraded for study limitations and imprecision). The final study (126 participants) compared octenidine dihydrochloride/phenoxyethanol (OHP) with Ringer's solution. We are uncertain whether OHP makes any difference to the number of wounds healed (RR 0.96, 95% CI 0.53 to 1.72) or to the change in ulcer size over time (we were unable to conduct independent statistical analysis of available data). The evidence is of very low certainty (we downgraded for study limitations and imprecision). None of the studies reported patient preference, ease of use of the method of cleansing, cost or health-related quality of life. In one study comparing propyl betaine and polihexanide with saline solution the authors do not report any adverse events occurring. We are uncertain whether OHP makes any difference to the number of adverse events compared with Ringer's solution (RR 0.58, 95% CI 0.29 to 1.14). The evidence is of very low certainty (we downgraded for study limitations and imprecision). AUTHORS' CONCLUSIONS: There is currently a lack of RCT evidence to guide decision making about the effectiveness of wound cleansing compared with no cleansing and the optimal approaches to cleansing of venous leg ulcers. From the four studies identified, there is insufficient evidence to demonstrate whether the use of PHMB solution compared with saline solution; aqueous oxygen peroxide compared with sterile water; propyl betaine and polihexanide compared with a saline solution; or OHP compared with Ringer's solution makes any difference in the treatment of venous leg ulcers. Evidence from three of the studies is of very low certainty, due to study limitations and imprecision. One study did not present data for the primary or secondary outcomes. Further well-designed studies that address important clinical, quality of life and economic outcomes may be important, based on the clinical and patient priority of this uncertainty.

ANTECEDENTES: Las úlceras de la pierna son heridas cutáneas abiertas que se producen por debajo de la rodilla, pero por encima del pie. La mayoría de las úlceras de la pierna son de origen venoso, y se producen como resultado de la insuficiencia venosa, en la que el flujo de sangre a través de las venas se ve afectado; suelen surgir debido a coágulos de sangre y venas varicosas. El tratamiento de compresión (vendas o medias) es el tratamiento principal para las úlceras venosas de la pierna. La limpieza de la herida se puede utilizar para eliminar los contaminantes superficiales, las bacterias, el tejido muerto y el exceso de líquido de la base de la úlcera y de la piel circundante; sin embargo, no se sabe con certeza cuál es la efectividad de la limpieza ni cuál es el mejor método o solución a utilizar. OBJETIVOS: Evaluar los efectos de la limpieza de heridas, las soluciones de limpieza de heridas y las técnicas de limpieza de heridas para el tratamiento de las úlceras venosas de la pierna. MÉTODOS DE BÚSQUEDA: En septiembre de 2019 se hicieron búsquedas en el Registro especializado del Grupo Cochrane de Heridas (Cochrane Wounds Group), en el Registro Cochrane central de ensayos controlados (CENTRAL); Ovid MEDLINE (incluido In­Process & Other Non­Indexed Citations); Ovid Embase y EBSCO CINAHL Plus. También se buscaron estudios en curso y no publicados en los registros de ensayos clínicos, y se examinaron las listas de referencias de los estudios incluidos pertinentes, así como de las revisiones, los metanálisis y los informes de tecnología sanitaria para identificar estudios adicionales. No hubo restricciones en cuanto al idioma, la fecha de publicación ni el contexto de los estudios. CRITERIOS DE SELECCIÓN: Se consideraron los ensayos controlados aleatorizados (ECA) que compararon la limpieza de heridas con ninguna limpieza de heridas, o ECA que compararon diferentes soluciones de limpieza de heridas o diferentes técnicas de limpieza de heridas. OBTENCIÓN Y ANÁLISIS DE LOS DATOS: Se examinaron los estudios para determinar si eran adecuados para inclusión, el riesgo de sesgo se evaluó mediante la herramienta Cochrane "Risk of bias" y se utilizó el método GRADE para determinar la certeza de la evidencia. Dos autores de la revisión realizaron estas tareas de forma independiente, utilizando criterios predeterminados. Cuando fue posible, se estableció contacto con los autores de los estudios para obtener los datos faltantes. RESULTADOS PRINCIPALES: Se incluyeron cuatro estudios con un total de 254 participantes. Todos los estudios incluyeron comparaciones entre diferentes tipos de soluciones de limpieza, y tres de ellos informaron sobre los desenlaces principales de esta revisión, cicatrización completa de la herida o cambio en el tamaño de la úlcera con el tiempo, o ambos. Dos estudios informaron sobre el desenlace secundario de dolor. Un estudio (27 participantes), que comparó la solución de polihexametileno biguanida (PHMB) con el suero fisiológico para la limpieza de las úlceras venosas de la pierna, no informó sobre ninguno de los desenlaces principales ni secundarios de la revisión. No se identificaron estudios que compararan la limpieza con ninguna limpieza, o que explorara comparaciones entre diferentes técnicas de limpieza. Un estudio (61 participantes) comparó el peróxido de oxígeno acuoso con el agua estéril. No hay certeza de que el peróxido de oxígeno acuoso suponga alguna diferencia en el número de heridas completamente cicatrizadas tras 12 meses de seguimiento (razón de riesgos [RR] 1,88; intervalo de confianza [IC] del 95%: 1,10 a 3,20). Del mismo modo, no hay certeza de que el peróxido de oxígeno acuoso suponga alguna diferencia en el cambio del tamaño de la úlcera tras ocho semanas de seguimiento (diferencia de medias [DM] ­1,38 cm2; IC del 95%: ­4,35 a 1,59 cm2). Por último, no hay certeza de que el peróxido de oxígeno acuoso suponga alguna diferencia en la reducción del dolor, evaluada tras ocho semanas de seguimiento mediante una calificación del dolor de 0 a 100 (DM 3,80; IC del 95%: ­10,83 a 18,43). La evidencia para estos desenlaces es de certeza muy baja (se disminuyó la calificación por las limitaciones del estudio y la imprecisión; para el desenlace dolor también se disminuyó la calificación por medidas indirectas). Otro estudio (40 participantes) comparó la propil betaína y la polihexanida con una solución salina. Los autores no presentaron los datos brutos en el informe del estudio, por lo que no fue posible realizar un análisis estadístico independiente de los datos. No se sabe si la propil betaína y la polihexanida suponen alguna diferencia en el número de heridas completamente cicatrizadas, en el cambio del tamaño de la úlcera con el tiempo o en la reducción del dolor de la herida. La evidencia es de certeza muy baja (se disminuyó por las limitaciones del estudio y la imprecisión). El último estudio (126 participantes) comparó el dihidrocloruro de octenidina/fenoxietanol (OHP) con la solución de Ringer. No hay certeza de que el OHP suponga alguna diferencia en el número de heridas cicatrizadas (RR 0,96; IC del 95%: 0,53 a 1,72) ni en el cambio del tamaño de la úlcera con el tiempo (no fue posible realizar un análisis estadístico independiente de los datos disponibles). La evidencia es de certeza muy baja (se disminuyó por las limitaciones del estudio y la imprecisión). Ninguno de los estudios informó sobre la preferencia de los pacientes, la facilidad de uso del método de limpieza, el coste o la calidad de vida relacionada con la salud. En un estudio en el que se compara la propil betaína y la polihexanida con la solución salina, los autores no informaron la aparición de eventos adversos. No hay certeza de que el OHP suponga alguna diferencia en el número de eventos adversos en comparación con la solución de Ringer (RR 0,58; IC del 95%: 0,29 a 1,14). La evidencia es de certeza muy baja (se disminuyó por las limitaciones del estudio y la imprecisión). CONCLUSIONES DE LOS AUTORES: En la actualidad se carece de evidencia de ECA para guiar la toma de decisiones sobre la efectividad de la limpieza de heridas en comparación con ninguna limpieza y los enfoques óptimos para la limpieza de las úlceras venosas de la pierna. A partir de los cuatro estudios identificados, no hay evidencia suficiente para demostrar si el uso de la solución PHMB en comparación con el suero fisiológico; el peróxido de oxígeno acuoso en comparación con el agua estéril; la betaína propil y la polihexanida en comparación con un suero fisiológico; o el OHP en comparación con la solución de Ringer supone alguna diferencia en el tratamiento de las úlceras venosas de la pierna. La evidencia de tres de los estudios es de certeza muy baja, debido a las limitaciones de los estudios y a la imprecisión. Un estudio no presentó datos para los desenlaces principales ni secundarios. Podría ser importante realizar más estudios bien diseñados que aborden desenlaces clínicos, de calidad de vida y económicos importantes, sobre la base de la prioridad clínica y para el paciente de esta falta de certeza.

Molecular basis of bacterial disinfectant resistance.

Antibiotic resistance could accelerate humanity towards an already fast-approaching post-antibiotic era, where disinfectants and effective biosecurity measures will be critically important to control microbial diseases. Disinfectant resistance has the potential to change our way of life from compromising food security to threatening our medical health systems. Resistance to antimicrobial agents occurs through either intrinsic or acquired resistance mechanisms. Acquired resistance occurs through the efficient transfer of mobile genetic elements, which can carry single, or multiple resistance determinants. Drug resistance genes may form part of integrons, transposons and insertions sequences which are capable of intracellular transfer onto plasmids or gene cassettes. Thereafter, resistance plasmids and gene cassettes mobilize by self-transmission between bacteria, increasing the prevalence of drug resistance determinants in a bacterial population. An accumulation of drug resistance genes through these mechanisms gives rise to multidrug resistant (MDR) bacteria. The study of this mobility is integral to safeguard current antibiotics, disinfectants and other antimicrobials. Literature evidence, however, indicates that knowledge regarding disinfectant resistance is severly limited. Genome engineering such as the CRISPR-Cas system, has identified disinfectant resistance genes, and reversed resistance altogether in certain prokaryotes. Demonstrating that these techniques could prove invaluable in the combat against disinfectant resistance by uncovering the secrets of MDR bacteria.

Use of low-frequency contact ultrasonic debridement with and without polyhexamethylene biguanide in hard-to-heal leg ulcers: an RCT protocol.

OBJECTIVE: The purpose of this research is to investigate the effect of low-frequency contact ultrasonic debridement therapy (LFCUD) in hard-to-heal wounds with suspected biofilm, and compare the effect with or without a surfactant antimicrobial on bacterial colony counts and wound healing rates. METHOD: A single-blinded randomised controlled trial (RCT) will investigate the combination of LFCUD and the antiseptic polyhexamethylene biguanide with a surfactant betaine (referred to in this paper as PHMB) as a topical solution post-treatment and in a sustained dressing, compared with use of LFCUD alone. Potential participants from a community wound clinic (n=50) will be invited to take part in the 12-week trial. Wound swabs and tissue samples will be analysed for bacterial type and quantity, before and after treatments, using traditional culture techniques and advanced molecular methods. Wound healing, pain, quality of life and biofilm (via a specifically designed tool) will also be measured. DISCUSSION: Bacteria have the potential to cause a hard-to-heal wound, particularly when antibiotics are too frequently and unnecessarily prescribed, resulting in antibiotic-resistant microorganisms. Appropriate care is vital when caring for hard-to-heal wounds to avoid these scenarios. With no simple laboratory method available to identify or treat wound biofilm, clinicians rely on their expertise in wound management. This study aims to provide in vivo evidence on the effectiveness of PHMB, to prevent the reformation of biofilm when applied after LFCUD. The aim is to provide evidence-based and more cost-effective wound care.

Nutrient Level Determines Biofilm Characteristics and Subsequent Impact on Microbial Corrosion and Biocide Effectiveness.

The impact that nutrient level has on biofilm characteristics, biocide effectiveness, and the associated risk of microbiologically influenced corrosion (MIC) was assessed using multispecies biofilms from two different oilfield consortia. A range of microbiological, microscopy, and corrosion methods demonstrated that the continuous flow of nutrients for the microbial growth resulted in higher activity, thickness, and robustness of the biofilms formed on carbon steel, which induced greater localized corrosion compared to biofilms formed under batch, nutrient-depleted conditions. Despite of the differences in biofilm characteristics, biofilms displayed comparable susceptibilities to glutaraldehyde biocide, with similar log10 reductions and percent reductions of microorganisms under both nutrient conditions. Nevertheless, nutrient replenishment impacted the effectiveness of the biocide in controlling microbial populations; a higher concentration of cells survived the biocide treatment in biofilms formed under a continuous flow of nutrients. Complementary DNA-/RNA-based amplicon sequencing and bioinformatics analysis were used to discriminate the active within the total populations in biofilms established at the different nutrient conditions and allowed the identification of the microbial species that remained active despite nutrient depletion and biocide treatment. Detection of persistent active microorganisms after exposure to glutaraldehyde, regardless of biofilm structure, suggested the presence of microorganisms less susceptible to this biocide and highlighted the importance of monitoring active microbial species for the early detection of biocide resistance in oil production facilities.IMPORTANCE Microbiologically influenced corrosion (MIC) is a complex process that generates economic losses to the industry every year. Corrosion must be managed to prevent a loss of containment of produced fluids to the external environment. MIC management includes the identification of assets with higher MIC risk, which could be influenced by nutrient levels in the system. Assessing biofilms under different nutrient conditions is essential for understanding the impact of flow regime on microbial communities and the subsequent impact on microbial corrosion and on the effectiveness of biocide treatment. This investigation simulates closely oil production systems, which contain piping sections exposed to continuous flow and sections that remain stagnant for long periods. Therefore, the results reported here are useful for MIC management and prevention. Moreover, the complementary methodological approach applied in this investigation highlighted the importance of implementing RNA-based methods for better identification of active microorganisms that survive stress conditions in oil systems.

The prevalence of Dichelobacter nodosus in clinically footrot-free sheep flocks: a comparative field study on elimination strategies.

BACKGROUND: Ovine footrot caused by Dichelobacter nodosus (D nodosus) is an infectious disease affecting sheep worldwide. Switzerland plans a nationwide footrot eradication program, based on PCR-testing of interdigital swab samples. The aim of this study was to test for the presence of D nodosus in clinically footrot-free sheep flocks which had been subjected to different treatment strategies, to assess whether they were feasible for the eradication process, especially focussing on antimicrobial flock treatments. Clinical scoring and PCR-results were compared. Ten farms had used hoof bathing and hoof trimming without causing bleeding, ten had used individual treatments and flock vaccines to gain the free status and ten had become free through whole-flock systemic macrolide treatment. For every farm, three risk-based collected pool samples were analysed for the occurrence of virulent and benign D nodosus by PCR detection of aprV2/aprB2. RESULTS: Six flocks from any treatment group tested positive for aprB2 in all pools. Clinical signs were absent at the time of sampling, but some flocks had experienced non-progressive interdigital inflammation previously. Two flocks tested aprV2-positive in the high-risk pool. One of them underwent a progressive footrot outbreak shortly after sampling. Individual retesting indicated, that virulent D nodosus most likely was reintroduced by a recently purchased ram. In the second flock, a ram was tested positive and treated before clinical signs occurred. CONCLUSIONS: All treatment strategies eliminated the causative agent and were found to be suitable for implementation in the PCR-based eradication process. PCR-testing proved to be more sensitive than visual scoring, as it also detected clinically healthy carriers. It will be of benefit as a diagnostic tool in elimination and surveillance programs.

Safety of tattoos and permanent make-up: a regulatory view.

The continuous increase in the popularity of tattoos and permanent make-up (PMU) has led to substantial changes in their societal perception. Besides a better understanding of pathological conditions associated with the injection of highly diverse substances into subepidermal layers of the skin, their regulation has occupied regulatory bodies around the globe. In that sense, current regulatory progress in the European Union is an exemplary initiative for improving the safety of tattooing. On one hand, the compilation of market surveillance data has provided knowledge on hazardous substances present in tattoo inks. On the other hand, clinical data gathered from patients enabled correlation of adverse reactions with certain substances. Nevertheless, the assessment of risks remains a challenge due to knowledge gaps on the biokinetics of highly complex inks and their degradation products. This review article examines the strategies for regulating substances in tattoo inks and PMU in light of their potential future restriction in the frame of the REACH regulation. Substance categories are discussed in terms of their risk assessment and proposed concentration limits.

Effect of a bundle-approach intervention against contamination of blood culture in the emergency department.

BACKGROUND: To prevent contamination when taking blood culture, there are various effective interventions. Whether there is greater efficacy by using a combination of these interventions has not been widely evaluated. METHODS: Our six-element intervention bundle aimed to prevent contamination of blood culture in our emergency department (ED). Elements were: use of 1% chlorhexidine alcohol, alcohol wiping, hand hygiene, using sterile gloves, using holed sterile cover, and selection of upper extremities as the site of venipuncture. We compared the contamination rate of blood culture between the pre- and the post-intervention periods among all cases with two or more blood cultures taken in our ED. We also evaluated the rate of patients receiving vancomycin among all those transferred to the hospital from the ED. RESULTS: During the pre- and post-intervention periods, 460 and 450 cases were included in analysis, respectively. Contamination of blood culture occurred in 29 pre-intervention cases (6.3%) and five post-interventional cases (1.1%) (relative risk 0.18, 95% confidence interval 0.07 to 0.45; P < 0.001). After bundle implementation, there was significant increase in adherence to using 1% chlorhexidine alcohol, alcohol wiping, hand hygiene, and using holed sterile covers. Among patients admitted to hospital, fewer patients received vancomycin during the post-intervention period than in the pre-intervention period (5.4% vs. 3.2%, P = 0.03). CONCLUSIONS: Our intervention bundle dramatically reduced the contamination rate when drawing blood culture in our ED.

Setting occupational exposure limits for antimicrobial agents: A case study based on a quaternary ammonium compound-based disinfectant.

Antimicrobial agents have become an essential tool in controlling the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and guidelines on their use have been issued by various public health agencies. Through its Emerging Viral Pathogen Guidance for Antimicrobial Pesticides, the US Environmental Protection Agency has approved numerous surface disinfectant products for use against SARS-CoV-2. Despite their widespread use and range of associated health hazards, the majority of active ingredients in antimicrobial products, such as surface disinfectants, lack established occupational exposure limits (OELs) to assist occupational health professionals in characterizing risks from exposures to these chemicals. Based on established approaches from various organizations, a framework for deriving OELs specific to antimicrobial agents was developed that relies on a weight-of-evidence evaluation of the available data. This framework involves (1) a screening-level toxicological assessment based on a review of the existing literature and recommendations, (2) identification of the critical adverse effect(s) and dose-response relationship(s), (3) identification of alternative health-based exposure limits (HBELs), (4) derivation of potential OELs based on identified points of departure and uncertainty factors and/or modification of existing alternative HBELs, and (5) selection of an appropriate OEL. To demonstrate the use of this framework, a case study is described for selection of an OEL for a disinfectant product containing quaternary ammonium compounds (quats). Three potential OELs were derived for this product based on irritation toxicity data, developmental and reproductive toxicity (DART) data, and modification of an existing HBEL. The final selected OEL for the quats-containing product was 0.1 mg/m3, derived from modification of an existing HBEL. This value represented the lowest resulting value of the three approaches, and thus, was considered protective of irritation and potential DART.

Dakin's solution in the treatment of severe diabetic foot infections.

Acute necrotising diabetic foot (DF) infections are common, costly, and do not infrequently result in debilitating major lower-extremity amputations. Dakin's solution is a long-standing topical antiseptic that has shown benefit in this clinical setting, but its use is undermined by a presumed risk of cytotoxicity. In this single-centre case series, we retrospectively evaluated 24 patients with severe necrotising DF infections treated with a cyclical instillation of Dakin's solution at a referral multidisciplinary DF unit. Most patients achieved favourable outcomes in infection control and limb salvage, with only one patient (4.2%) requiring a major (at or above-the-ankle) amputation. The mean time to complete or near-complete wound granulation was 5.4 weeks. Of the 12 patients who completed 12 or more months of longitudinal follow up, only 2 (12.2%) had a wound recurrence. In this severe DF infection patient cohort, Dakin's solution led to a clinically meaningful improvement. No remarkable impairment in the wound-healing process was observed.

Covid-19: a survey on knowledge, awareness and hygiene practices among dental health professionals in an Indian scenario.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 or COVID-19) continues to spread globally. It has become a major cause of concern for health care professionals all over the world. Objective: The aim of this study was to assess knowledge, awareness and hygiene practices regarding COVID-19 among private dental practitioners practicing in Tricity (Chandigarh, Panchkula and Mohali) in India during these critical times. Materials and Methods: A total of 245 private dentists participated in this cross-sectional survey and finally 215 constituted the final sample size. A self-administered, multiple choice type questionnaire (verified by a specialist) was administered to obtain information from the subjects. The questionnaire was divided into two parts and included 15 questions on knowledge and awareness regarding COVID-19. Statistical analysis was done using ANOVA and Student's t-test. Results: Percentage of subjects who answered correctly regarding main symptoms of COVID-19 and primary mode of transmission was 87% and 82.5% respectively. One-third of the subjects were not aware regarding Personal Protective Equipment (PPE) to be used while rendering dental treatment. 75% of subjects were of the opinion that supportive care is the current treatment regime for COVID-19. Less than one-third of subjects (30.2%) reported high scores. Education level (p=0.018) and health sector profile (p=0.024) of the subjects were significantly associated with mean knowledge scores. Conclusion: The findings of the present study showed that some notable deficiencies in knowledge existed among dental professionals regarding some vital aspects of COVID-19. Therefore, there is an urgent need for improving dentists'knowledge via health education and training programs. Further studies on the subject are also warranted once the situation normalizes.

Acanthamoeba keratitis related to contact lens use in a tertiary hospital in China.

BACKGROUND: To report the clinical and microbiological features of Acanthamoeba keratitis (AK) related to contact lens use in a tertiary hospital in China. METHODS: In this retrospective study, the medical results of 61 cases of AK related to contact lens use from January 2000 to December 2017 were reviewed. The data included patients' demographics, lens type, history, risk factors, disease stages, corneal scraping and culture reports, and treatments. Moreover, genotypic identification of some of the isolates was carried out with a PCR assay and sequence analysis of the 18S ribosomal DNA gene. RESULTS: There were 64 eyes included in the study. A total of 32.8% of the patients wore soft contact lenses, and 67.2% of patients used overnight orthokeratology. In the cases (20 eyes) in the early stage, 65% (13 eyes) had positive results according to Giemsa-stained smears, and 0.9% sodium chloride (NaCl) wet mounts revealed trophozoites in 7 eyes (35%). Six eyes (30%) were diagnosed by confocal microscopy combined with clinical signs. In the orthokeratology patients, 87.8% (36/41) rinsed their lenses and/or cases with tap water; 55% of soft-lens wearers wore their lenses while showering. The genotype of 9 isolates was determined, and all the strains belonged to genotype T4. In the orthokeratology group, the number of patients who required therapeutic penetrating keratoplasty after 2005 was less than that before 2005 (chi-square test, χ2 = 4.209, P = 0.04). CONCLUSIONS: More than two-thirds of the cases were associated with orthokeratology. Examinations with Giemsa-stained smears, 0.9% NaCl wet mounts and confocal microscopy should be performed for patients who are highly suspected of having early-stage AK to help with early diagnosis. In the orthokeratology group, the rate of therapeutic keratoplasty after 2005 was less than that before 2005.

The influence of two forms of chlorhexidine on the accuracy of contemporary electronic apex locators.

BACKGROUND: Accurate determination of working length (WL) is crucial for the success of endodontic therapy. The aim of this study was to determine the influence of 2% chlorhexidine digluconate solution, 2% chlorhexidine digluconate gel and 2% hypochlorite solution on the accuracy of two devices: the Raypex 5 and the ApexDal. METHODS: Twenty-nine single-rooted human teeth were used in this study. The crowns were cut horizontally and embedded in an alginate mass. In each tooth, six endodontic measurements were made using two electronic apex locators (EALs): a Raypex 5 and an ApexDal. For each EAL, measurements were taken with the following products: 2% chlorhexidine solution (CHX-S group), 2% chlorhexidine gel (CHX-G group) and 2% NaOCl (NaOCl group). After performing an endodontic measurement, the endodontic instruments were stabilized with flow resin composite. Afterwards, the roots were removed from the alginate mass, and the apical one-third of each root was cut lengthways to recover the canal system. Last, the distance between the file tip and the apical foramen was measured under a microscope at 60 x magnification. RESULTS: Statistically significant differences were found between CHX-S and NaOCl and CHX-G and NaOCl, but no significant differences were detected between CHX-S and CHX-G during the testing of both devices. No statistically significant differences were observed between the Raypex 5 and ApexDal for all intracanal media tested. CONCLUSION: The EALs Raypex 5 and ApexDal had higher accuracy in the anatomical foramen of the root containing chlorhexidine in the gel or in the solution form than in the canal containing sodium hypochlorite.

Chlorhexidine 0.5%/70% Alcohol and Iodine 1%/70% Alcohol Both Reduce Bacterial Load in Clean Foot Surgery: A Randomized, Controlled Trial.

No consensus exists regarding which cleansing technique, solution, and concentration should be used in orthopedic surgery. The aim of this randomized, controlled trial was to compare the effect of chlorhexidine 0.5%/70% alcohol with iodine 1%/70% alcohol on lowering positive cultures before elective foot surgery and to study any wound complications, infections and allergic reactions. Consecutive patients ≥18 years of age scheduled for a hallux valgus correction or arthrodesis of the first metatarsophalangeal joint were included. Swabs were taken from 2 sites before and twice after preparing the skin and were quantitatively and qualitatively analyzed. The study group consisted of 49 patients with a mean age of 52.3 ± 14.4 (range 22 to 75) years of whom 42 (86%) were female. No significant differences were observed for positive cultures between the chlorhexidine (73%, 2%, and 12%) and iodine (68%, 7%, and 9%) group at any time point. Coagulase-negative staphylococci were the most commonly isolated micro-organisms found after skin preparation. Occasionally, Bacillus spp and Corynebacterium spp were cultured. The complication rate 2 weeks postoperatively was 0% in the chlorhexidine group versus 8.7% (n = 2) in the iodine group (delayed wound healing; p = .215). The complication rate at 6 weeks postoperatively was, respectively, 3.8% (n = 1) versus 4.3% (n = 1; both showed swelling and redness; p > .999). There was no significant difference in postoperative wound problems or infection rates between the 2 skin preparation solutions. Chlorhexidine 0.5%/70% alcohol and iodine 1%/70% alcohol both decreased the amount of positive cultures in elective foot surgery.

Surfactants: Role in biofilm management and cellular behaviour.

Appropriate and effective wound cleaning represents an important process that is necessary for preparing the wound for improved wound healing and for helping to dislodge biofilms. Wound cleaning is of paramount importance to wound bed preparation for helping to enhance wound healing. Surfactant applications in wound care may represent an important area in the cleaning continuum. However, understanding of the role and significance of surfactants in wound cleansing, biofilm prevention and control, and enhancing cellular viability and proliferation is currently lacking. Despite this, some recent evidence on poloxamer-based surfactants where the surfactants are present in high concentration have been shown to have an important role to play in biofilm management; matrix metalloproteinase modulation; reducing inflammation; and enhancing cellular proliferation, behaviour, and viability. Consequently, this review aims to discuss the role, mode of action, and clinical significance of the use of medically accepted surfactants, with a focus on concentrated poloxamer-based surfactants, to wound healing but, more specifically, the role they may play in biofilm management and effects on cellular repair.

Comprehensive Review and Comparison of the Disinfection Techniques Currently Available in the Literature.

The goal of disinfection in the dental office is to prevent the spread of infection from one patient to another and maintain the safety of the dental care providers. Prevention of cross infection has significant effect on infection control. The standard procedure of rinsing impressions under tap water immediately after removal from the mouth eliminates microorganisms along with saliva and blood. A broad search on published literature was done using the keywords impression materials, disinfection method, and sterilization of dental impression from 1980 to 2016 in Medline, Google Scholar, the internet, and textbooks. This article critically analyzes the various published methods of dental impression disinfection in dentistry.

Keratomycosis due to Tintelnotia destructans refractory to common therapy treated successfully with systemic and local terbinafine in combination with polyhexamethylene biguanide.

PURPOSE: To report on a wearer of rigid gas-permeable contact lenses with a keratomycosis due to Tintelnotia-a new genus of Phaeosphaeriaceae-treated with terbinafine and polyhexamethylene biguanide. METHODS: Chart review of a patient with fungal keratitis treated additionally with systemic and topical terbinafine 0.25% after symptoms increased under conventional antimycotic therapy with voriconazole. Antifungal susceptibility had been tested in vitro. RESULTS: After starting an additional treatment with systemic and topical terbinafine, the severe corneal infection was sufficiently resolved. The drug was well tolerated without any neurological, dermatological or gastroenterological problems. Terbinafine revealed a marked in vitro antifungal activity of 0.12 µg/ml. The fungus was identified as Tintelnotia destructans. CONCLUSIONS: Terbinafine might be considered as a therapeutic option in severe cases of fungal keratitis refractory to common antifungal therapy.