Combined Phialemonium curvatum and Acanthamoeba Keratitis: The Importance of Early Diagnosis and Specific Therapy.

PURPOSE: To report the clinical and confocal findings of a unique case of combined Phialemonium curvatum and Acanthamoeba keratitis and to highlight the role of the prompt diagnosis and specific medical treatment in preserving visual function. METHODS: A case report and literature review. RESULTS: A 54-year-old woman presented with a 3-day history of visual impairment, photophobia, and ocular pain in her right eye. Her best corrected visual acuity was 0.4 Logarithm of the Minimum Angle of Resolution scale, and the slit-lamp examination showed whitish corneal stromal infiltrate with satellite lesions. In vivo confocal microscopy evidenced Acanthamoeba cysts and fungal hyphae that resulted P. curvatum in the culture examination. The intensive medical treatment was started with topical 0.02% polyhexamethylene biguanide, voriconazole 1%, and moxifloxacin hydrochloride 0.5%. Progressive improvement of clinical and confocal pictures was registered with a complete recovery of visual function after 1 month. CONCLUSIONS: This is the first case report of combined P. curvatum and Acanthamoeba keratitis. The fast diagnosis with in vivo confocal microscopy allowed early and intensive specific treatment with recovery of corneal infection.

Evidence-Based Review of Antibiofilm Agents for Wound Care.

Significance: Biofilms in vivo are small densely packed aggregations of microbes that are highly resistant to host immune responses and treatment. They attach to each other and to nearby surfaces. Biofilms are difficult to study and identify in a clinical setting as their quantification necessitates the use of advanced microscopy techniques such as confocal laser scanning microscopy. Nonetheless, it is likely that biofilms contribute to the pathophysiology of chronic skin wounds. Reducing, removing, or preventing biofilms is thus a logical approach to help clinicians heal chronic wounds. Recent Advances: Wound care products have demonstrated varying degrees of efficacy in destroying biofilms in in vitro and preclinical models, as well as in some clinical studies. Critical Issues: Controlled studies exploring the beneficial role of biofilm eradication and its relationship to healing in patients with chronic wounds are limited. This review aims to discuss the mode of action and clinical significance of currently available antibiofilm products, including surfactants, dressings, and others, with a focus on levels of evidence for efficacy in disrupting biofilms and ability to improve wound healing outcomes. Future Directions: Few available products have good evidence to support antibiofilm activity and wound healing benefits. Novel therapeutic strategies are on the horizon. More high-quality clinical studies are needed. The development of noninvasive techniques to quantify biofilms will facilitate increased ease of research about biofilms in wounds and how to combat them.

Oral Miltefosine as Salvage Therapy for Refractory Acanthamoeba Keratitis.

PURPOSE: To report a case series of patients with treatment-resistant Acanthamoeba keratitis (AK) using oral miltefosine, often as salvage therapy. DESIGN: Descriptive, retrospective multicenter case series. METHODS: We reviewed 15 patients with AK unresponsive to therapy who were subsequently given adjuvant systemic miltefosine between 2011 and 2017. The main outcome measures were resolution of infection, final visual acuity, tolerance of miltefosine, and clinical course of disease. RESULTS: All patients were treated with biguanides and/or diamidines or azoles without resolution of disease before starting miltefosine. Eleven of 15 patients retained count fingers or better vision, and all were considered disease free at last follow-up. Eleven of 15 patients had worsening inflammation with miltefosine, with 10 of them improving with steroids. Six patients received multiple courses of miltefosine. Most tolerated oral miltefosine well, with mild gastrointestinal symptoms as the most common systemic side effect. CONCLUSIONS: Oral miltefosine is a generally well-tolerated treatment adjuvant in patients with refractory AK. The clinician should be prepared for a steroid-responsive inflammatory response frequently encountered during the treatment course.

Structure and State of Water in Branched N-Vinylpyrrolidone Copolymers as Carriers of a Hydrophilic Biologically Active Compound.

Hydrated copolymers of N-vinylpyrrolidone (VP) with triethylene glycol dimethacrylate as a promising platform for biologically active compounds (BAC) were investigated by different physical chemical methods (dynamic light scattering, infrared spectroscopy, thermal gravimetric analysis, and differential scanning calorimetry) and the quantum chemical modeling of water coordination by the copolymers in a solution. According to the quantum chemical simulation, one to two water molecules can coordinate on one O-atom of the lactam ring of VP units in the copolymer. Besides the usual terminal coordination, the water molecule can form bridges to bind two adjacent C=O groups of the lactam rings of VP units. In addition to the first hydration shell, the formation of a second one is also possible due to the chain addition of water molecules, and its structure depends on a mutual orientation of C=O groups. We showed that N,N-dimethylbiguanidine hydrochloride (metformin) as a frontline drug for the treatment of type 2 diabetes mellitus can be associated in aqueous solutions with free and hydrated C=O groups of the lactam rings of VP units in studied copolymers. Based on the characteristics of the H-bonds, we believe that the level of the copolymer hydration does not affect the behavior and biological activity of this drug, but the binding of metformin with the amphiphilic copolymer will delight in the penetration of a hydrophilic drug across a cell membrane to increase its bioavailability.

Synergistic Effect and Antibiofilm Activity of a Skin and Wound Cleanser.

INTRODUCTION: Biofilm in chronic wounds impedes the wound healing process. Each biofilm has differing characteristics requiring a multifaceted approach for removal while maintaining a surrounding environment conducive to wound healing. OBJECTIVE: In this study, 3 of the components in a wound cleanser are tested to determine synergy in eradicating biofilms of methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa in vitro. MATERIALS AND METHODS: The 3 components assessed for synergy were ethylenediamine tetraacetic acid sodium salts (EDTA), vicinal diols (VD; ethylhexylglycerin and octane-1,2-diol), and polyhexamethylene biguanide (PHMB). Each component was assessed individually and in combination while dissolved in a base solution. The Calgary assay method was used for biofilm growth and treatment. Kull Equation analysis for synergy was conducted using viable count results. RESULTS: Synergy is defined as the interaction of components to produce a combined effect greater than the sum of their separate effects. The base solution containing all 3 components (EDTA, VD, and PHMB) reduced biofilm viability by more than 5 logs, demonstrating statistically significant synergy. The 3 components tested individually in the base solution resulted in the following: EDTA did not reduce bacteria viability; VD reduced viability by about 1 log; and PHMB reduced P aeruginosa viability by about 2.5 logs and MRSA viability by about 4 logs. Of importance, the MRSA biofilm failed to regrow in the recovery plates after combined treatment, indicating complete elimination of the biofilm bacteria. CONCLUSIONS: The experimental and calculated results indicate the 3 components (VD, EDTA, and PHMB) when used together act synergistically to eradicate MRSA and P aeruginosa biofilms in vitro.

Biguanide-Derived Polymeric Nanoparticles Kill MRSA Biofilm and Suppress Infection In Vivo.

Methicillin-resistant Staphylococcus aureus (MRSA) is a significant cause of drug-resistant infections. Its propensity to develop biofilms makes it especially resistant to conventional antibiotics. We present a novel nanoparticle (NP) system made from biocompatible F-127 surfactant, tannic acid (TA), and biguanide-based polymetformin (PMET) (termed FTP NPs), which can kill MRSA biofilm bacteria effectively in vitro and in vivo and which has excellent biocompatibility. FTP NPs exhibit biofilm bactericidal activity-ability to kill bacteria both inside and outside biofilm-significantly better than many antimicrobial peptides or polymers. At low concentrations (8-32 µg/mL) in vitro, FTP NPs outperformed PMET with ∼100-fold (∼2 log10) greater reduction of MRSA USA300 biofilm bacterial cell counts, which we attribute to the antifouling property of the hydrophilic poly(ethylene glycol) contributed by F-127. Further, in an in vivo murine excisional wound model, FTP NPs achieved 1.8 log10 reduction of biofilm-associated MRSA USA300 bacteria, which significantly outperformed vancomycin (0.8 log10 reduction). Moreover, in vitro cytotoxicity tests showed that FTP NPs have less toxicity than PMET toward mammalian cells, and in vivo intravenous injection of FTP NPs at 10 mg/kg showed no acute toxicity to mice with negligible body weight loss and no significant perturbation of blood biomarkers. These biguanide-based FTP NPs are a promising approach to therapy of MRSA infections.

Activation of AMPK by Medicinal Plants and Natural Products: Its Role in Type 2 Diabetes Mellitus.

Type-2 Diabetes (T2D) is a metabolic disease characterized by permanent hyperglycemia, whose development can be prevented or delayed by using therapeutic agents and implementing lifestyle changes. Some therapeutic alternatives include regulation of glycemia through modulation of different mediators and enzymes, such as AMP-activated protein kinase (AMPK), a highly relevant cellular energy sensor for metabolic homeostasis regulation, with particular relevance in the modulation of liver and muscle insulin sensitivity. This makes it a potential therapeutic target for antidiabetic drugs. In fact, some of them are standard drugs used for treatment of T2D, such as biguanides and thiazolidindiones. In this review, we compile the principal natural products that are activators of AMPK and their effect on glucose metabolism, which could make them candidates as future antidiabetic agents. Phenolics such as flavonoids and resveratrol, alkaloids such as berberine, and some saponins are potential natural activators of AMPK with a potential future as antidiabetic drugs.

Inhibition of Bromelain Activity During Enzymatic Debridement of Burn Wounds Pretreated With Frequently Used Products.

An enzyme mixture containing bromelain (NexoBrid®) was found to be suitable for enzymatic debridement of burn wounds, as determined by the criteria of patient comfort and pain, selectivity, and efficiency. Nevertheless, daily experience showed that pretreatment of burn wounds with several other clinical agents may inhibit debridement efficiency. Therefore, the current study was performed to identify those agents and evaluate their debridement inhibition capabilities. The impact of several common agents as well pH, on NexoBrid® debridement efficiency was evaluated in vitro. A collagen-based dermal substitute (MatriDerm®) was exposed to NexoBrid® in the presence of different agents of varying concentrations. Digestion was documented. The criteria used for judging digestion were independently classified by 3 investigators at least 3 times in succession. When a low concentration (1.0 mg/ml) of NexoBrid® was used, a ≥ 50% concentration of Prontosan® had an impact on enzymatic activity. Comparable results were obtained when even lower concentrations of Octenisept® (≥ 10%) were used. A 100-µmol/L concentration of copper inhibited the enzymatic activity of both a low (1.0 mg/ml) and high (10 mg/ml) concentration of NexoBrid®. Silver-sulfadiazine at concentrations of 10% and 90% inhibited the activity of 1 mg/ml NexoBrid®. No complete inhibition of NexoBrid® activity occurred at any concentration of iron. We recommend using polyhexanide-containing agents (Prontosan®) to rinse and presoak burn wounds. Pretreatment of burn wounds with agents containing silver and copper should be avoided. Experimentally, we found a partial inhibition of NexoBrid® activity at the distinct pH values of 3 and 11.

Metformin: historical overview.

Metformin (dimethylbiguanide) has become the preferred first-line oral blood glucose-lowering agent to manage type 2 diabetes. Its history is linked to Galega officinalis (also known as goat's rue), a traditional herbal medicine in Europe, found to be rich in guanidine, which, in 1918, was shown to lower blood glucose. Guanidine derivatives, including metformin, were synthesised and some (not metformin) were used to treat diabetes in the 1920s and 1930s but were discontinued due to toxicity and the increased availability of insulin. Metformin was rediscovered in the search for antimalarial agents in the 1940s and, during clinical tests, proved useful to treat influenza when it sometimes lowered blood glucose. This property was pursued by the French physician Jean Sterne, who first reported the use of metformin to treat diabetes in 1957. However, metformin received limited attention as it was less potent than other glucose-lowering biguanides (phenformin and buformin), which were generally discontinued in the late 1970s due to high risk of lactic acidosis. Metformin's future was precarious, its reputation tarnished by association with other biguanides despite evident differences. The ability of metformin to counter insulin resistance and address adult-onset hyperglycaemia without weight gain or increased risk of hypoglycaemia gradually gathered credence in Europe, and after intensive scrutiny metformin was introduced into the USA in 1995. Long-term cardiovascular benefits of metformin were identified by the UK Prospective Diabetes Study (UKPDS) in 1998, providing a new rationale to adopt metformin as initial therapy to manage hyperglycaemia in type 2 diabetes. Sixty years after its introduction in diabetes treatment, metformin has become the most prescribed glucose-lowering medicine worldwide with the potential for further therapeutic applications.

The Dramatic Recovery of a Patient with Biguanide-associated Severe Lactic Acidosis Following Thiamine Supplementation.

Biguanides are a drug of choice for the treatment of type 2 diabetes mellitus. Although they can cause lactic acidosis in susceptible patients with predisposing risk factors, the incidence of lactic acidosis is reported to be very low when they are used properly. We herein present a case of biguanide-associated severe lactic acidosis complicated with thiamine deficiency that was provoked without predisposing factors for thiamine deficiency. Diabetic patients taking biguanide may be predisposed to thiamine deficiency, even when there is no evidence of risk factors, and the high-dose administration of thiamine may be essential in the treatment of this otherwise under-recognized disorder.

Effectiveness of final decontamination protocols against Enterococcus faecalis and its influence on bond strength of filling material to root canal dentin.

AIM: The aim of this study was to evaluate the effectiveness of final decontamination protocols against Enterococcus faecalis and their influence on bond strength of filling material to root canal dentin. MATERIAL AND METHODS: Ninety root canals were enlarged with ProTaper system and inoculated with E. faecalis for 15days. Sixty samples were randomly divided into six groups (n=10) and subjected to following protocols: G1-distilled water(control), G2-2% chlorhexidine, G3-QMix, G4-6.5% grape seed extract, G5-photodynamic therapy with optical fiber and G6-photodynamic therapy without optical fiber. The percentage of bacterial reduction was checked by counting of CFUs. The remaining 30 samples were subjected to the same decontamination protocols (n=5) and filled with gutta-percha and AH Plus sealer in order to perform the push-out test. Data from both tests were subjected to one-way ANOVA followed by Tukey's post hoc procedure (α=0.05). RESULTS: The greatest bacterial reduction was observed for 2% chlorhexidine, QMix and 6.5% grape seed extract, with no statistically significant difference between them. Photodynamic therapy, with and without optical fiber, demonstrated a significantly higher reduction than distilled water, with no statistically significant difference between them (p<0.05). For the push-out test, final decontamination protocols showed similar bond strength values (p<0.05), with the highest incidence of cohesive failure in all groups. CONCLUSIONS: The tested final decontamination protocols showed effectiveness against E. faecalis and did not interfere with the bond strength of filling material to root canal dentin.

Natural Products to Counteract the Epidemic of Cardiovascular and Metabolic Disorders.

Natural products have always been exploited to promote health and served as a valuable source for the discovery of new drugs. In this review, the great potential of natural compounds and medicinal plants for the treatment or prevention of cardiovascular and metabolic disorders, global health problems with rising prevalence, is addressed. Special emphasis is laid on natural products for which efficacy and safety have already been proven and which are in clinical trials, as well as on plants used in traditional medicine. Potential benefits from certain dietary habits and dietary constituents, as well as common molecular targets of natural products, are also briefly discussed. A glimpse at the history of statins and biguanides, two prominent representatives of natural products (or their derivatives) in the fight against metabolic disease, is also included. The present review aims to serve as an "opening" of this special issue of Molecules, presenting key historical developments, recent advances, and future perspectives outlining the potential of natural products for prevention or therapy of cardiovascular and metabolic disease.

A novel approach to antibiofilm susceptibility testing using a thermo-reversible matrix.

OBJECTIVE: Biofilm microorganisms are known to have a much higher tolerance to antimicrobials compared to their planktonic equivalents. Therefore, traditional antimicrobial susceptibility testing may not extrapolate to clinical treatment of infections of biofilm origin, and as a result, there is a need to not only develop antimicrobials with antibiofilm activity, but also suitable in vitro testing methods for their evaluation. In this study, we report on a novel method of antibiofilm testing using a thermo-reversible matrix (poloxamer 407), coupled with live/dead staining of bacteria cultured from the matrix. METHOD: Pseudomonas aeruginosa (NCIMB 8626) was cultured in medium containing poloxamer 407 at 37°C for 24 hours to generate biofilms. The preparation was cooled to liquefy the poloxamer and allow recovery of the biofilm cells, which were then stained with SYTO9 to determine viability following exposure to four antimicrobials: polyhexanide, octenadine dihydrochloride, povidone-iodine and silver carbonate. Over an 8-minute time period, fluorescence levels were spectrophotometrically measured and compared with bacterial controls, cultured in the absence of poloxamer and without antimicrobial. RESULTS: Untreated cells showed no reduction in viability over this period. Importantly, planktonic cells were more susceptible to test agents compared with those of a 'biofilm' phenotype cultured in poloxamer. Antibiofilm activity was evident for all of the test agents, with highest relative activity seen with octenadine dihydrochloride. CONCLUSION: In summary, a novel and relatively rapid approach to screen compounds for antibiofilm activity has been described. The method uses standard laboratory equipment and can be readily adapted to test a wide range of microorganisms and other antibiofilm compounds. DECLARATION OF INTEREST: This research was, in part, supported by Advanced Medical Solutions in the form of a Knowledge Transfer Project. Mr J. Nosworthy was employed by Advanced Medical Solutions. There are no other conflicts of interests to declare.

Therapeutic inertia and intensified treatment in diabetes mellitus prescription patterns: A nationwide population-based study in Taiwan.

Objective To measure therapeutic inertia by characterizing prescription patterns using secondary data obtained from the nationwide diabetes mellitus pay-for-performance (DM-P4P) programme in Taiwan. Methods Using reimbursement claims from Taiwan's National Health Insurance Research Database, a nationwide retrospective cohort study was undertaken of patients with diabetes mellitus who participated in the DM-P4P programme from 2006-2008. Glycosylated haemoglobin results were used to evaluate modifications in therapy in response to poor diabetes control. Prescription patterns were used to assign patients to either a therapeutic inertia group or an intensified treatment group. Therapeutic inertia was defined as the failure to act on a known problem. Results The research sample comprised of 168 876 patients with diabetes mellitus who had undergone 899 135 tests. Of these, 37.4% (336 615 visits) of prescriptions were for a combination of two types of drug and 27.7% (248 788 visits) were for a combination of three types of drug. The proportion of patients in the intensified therapy group who were prescribed more than two types of drug was considerably higher than that in the therapeutic inertia group. Conclusion In many cases in the therapeutic inertia group only a single type of hypoglycaemic drug was prescribed or the dosage remained unchanged.

Expression and clinical significance of the HIF-1a/ET-2 signaling pathway during the development and treatment of polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) is a major health problem in reproductive-aged women worldwide, but the precise pathogenesis of PCOS remains unclear. Our previous study revealed that hypoxia-inducible factor (HIF)-1a mediated endothelin (ET)-2 signaling plays an important role in ovulation in rats. Therefore, the present study used a PCOS rat model to test the hypotheses that HIF-1a signaling is expressed and inhibited in ovaries during PCOS formation and that the HIF-1a/ET-2 signaling pathway is a target of dimethyldiguanide (DMBG) in the clinical treatment of PCOS. First, the development of a PCOS model and the effect of DMBG treatment were examined through ovarian histology and serum hormone levels, which were consistent with previous reports. Second, HIF-1a and ET-2 expression were detected by immunohistochemistry and western blot. The results showed decreased HIF-1a/ET-2 expression in the ovaries of PCOS rats, whereas DMBG treatment reversed the protein decreases and improved the PCOS symptoms. Third, to understand the molecular mechanism, HIF-1a/ET-2 mRNA expression was also examined. Interestingly, HIF-1a mRNA increased in the ovaries of PCOS rats, while ET-2 mRNA decreased, indicating that HIF-1a protein degradation may be involved in POCS development and treatment. Finally, HIF prolyl hydroxylase (PHD) activity was examined to further clarify the contribution of HIF-1a signaling to the development and treatment of PCOS. The results suggested that the inhibition of HIF-1a/ET-2 signaling may be caused by increased PHD activity in PCOS. DMBG-treated PCOS may further activate HIF-1a signaling at least partly through inhibiting PHD activity. Taken together, these results indicate that HIF-1a signaling is inhibited in a PCOS rat model through increasing PHD activity. DMBG treatment improved PCOS by rescuing this pathway, suggesting that HIF-1a signaling plays an important role in the development and treatment of PCOS. This HIF-1a-mediated ET-2 signaling pathway may be an important mechanism regulating PCOS formation and treatment in mammalian ovaries in vivo and should be a new clinical target for PCOS prevention and treatment in the future.

Effects of different sonic activation protocols on debridement efficacy in teeth with single-rooted canals.

OBJECTIVES: The effects of different EndoActivator® (EA) sonic activation protocols on root canal debridement efficacy were examined. METHODS: Root canals in 48 single-rooted teeth were instrumented, irrigated initially with NaOCl and divided into 6 groups (N=8) based on the application time of QMix (antimicrobial calcium-chelating irrigant), and the time and sequence of EA irrigant activation - Positive Control: 90s QMix; Negative Control: 90s saline; Group 1A: 15s QMix+15s QMix with EA-activation; Group 1B: 30s QMix+30s of QMix with EA-activation; Group 2A: 15s QMix with EA-activation+15s QMix; Group 2B: 30s QMix with EA-activation+30s QMix. Split roots were examined with scanning electron microscopy for assignment of smear and debris scores in locations along the coronal, middle and apical thirds of the canals. The overall cleanliness of pooled canal locations in the Positive Control and the 4 experimental groups were compared with chi-square tests. RESULTS: Significant differences were detected among the 5 groups (P<0.001). Post hoc pairwise comparisons indicated that the overall canal cleanliness was in the order (from best to worst): 1B=2B>2A>1A>Positive Control. Completely clean canals could not be achieved due to the absence of continuous irrigant flow for EA to clear intraradicular debris. CONCLUSIONS: Irrespective of the sonic activation sequence, irrigant activation for 30s during a 60-s period of QMix application appears to maximise the smear layer and debris removal potential of the EndoActivator® system. CLINICAL SIGNIFICANCE: Sonic activation of root canal irrigants produces cleaner root canals and reduces the time required for final delivery of a canal wall smear later-removing irrigant when compared to the use of needle irrigation alone.

Extending the TIME concept: what have we learned in the past 10 years?(*).

The TIME acronym (tissue, infection/inflammation, moisture balance and edge of wound) was first developed more than 10 years ago, by an international group of wound healing experts, to provide a framework for a structured approach to wound bed preparation; a basis for optimising the management of open chronic wounds healing by secondary intention. However, it should be recognised that the TIME principles are only a part of the systematic and holistic evaluation of each patient at every wound assessment. This review, prepared by the International Wound Infection Institute, examines how new data and evidence generated in the intervening decade affects the original concepts of TIME, and how it is translated into current best practice. Four developments stand out: recognition of the importance of biofilms (and the need for a simple diagnostic), use of negative pressure wound therapy (NPWT), evolution of topical antiseptic therapy as dressings and for wound lavage (notably, silver and polyhexamethylene biguanide) and expanded insight of the role of molecular biological processes in chronic wounds (with emerging diagnostics and theranostics). Tissue: a major advance has been the recognition of the value of repetitive and maintenance debridement and wound cleansing, both in time-honoured and novel methods (notably using NPWT and hydrosurgery). Infection/inflammation: clinical recognition of infection (and non infective causes of persisting inflammation) is critical. The concept of a bacterial continuum through contamination, colonisation and infection is now widely accepted, together with the understanding of biofilm presence. There has been a return to topical antiseptics to control bioburden in wounds, emphasised by the awareness of increasing antibiotic resistance. Moisture: the relevance of excessive or insufficient wound exudate and its molecular components has led to the development and use of a wide range of dressings to regulate moisture balance, and to protect peri-wound skin, and optimise healing. Edge of wound: several treatment modalities are being investigated and introduced to improve epithelial advancement, which can be regarded as the clearest sign of wound healing. The TIME principle remains relevant 10 years on, with continuing important developments that incorporate new evidence for wound care.

Benefit of polyhexamethylene biguanide in Fusarium keratitis.

PURPOSE: To report a series of 3 patients with soft contact lens-related Fusarium keratitis. Two of them were treated with the antiamoebic polyhexamethylene biguanide 0.02% (PHMB) in combination with antifungal drugs, and 1 patient was treated with PHMB as sole antifungal regimen. METHODS: Chart review of 3 patients treated with PHMB in Fusarium keratitis. Two of them were refractory to the commonly used therapy. The antifungal power of PHMB and propamidine isethionate was tested against the patients' isolates as well as against the clinical isolates from another 9 patients with ocular mould infections. RESULTS: An excellent outcome could be achieved in 2 patients with Fusarium solani keratitis refractory to common antifungal treatment by the additional use of PHMB 0.02%. In another patient PHMB alone was sufficient to resolve Fusarium proliferatum infection. The drug was well tolerated. In all patients repeated abrasion was done for better penetration of the drugs. PHMB revealed a marked in vitro antifungal activity for the three Fusarium isolates as well as for another 9 isolates of ocular infections from other patients including also the genera Scedosporium, Aspergillus and Rhizopus giving minimal inhibitory concentrations ranging from 1.56 to 3.12 µg/ml. CONCLUSIONS: Fusarium keratitis is a severe ocular infection. We report on the use of PHMB in 3 patients given additionally or as sole antifungal drug. We emphasize the benefit of PHMB 0.02% in Fusarium keratitis which might be considered as a therapeutic option especially in cases refractory to common antifungal therapy and possibly in keratitis due to other fungi.

Polyhexamethylene biguanide and calcineurin inhibitors as novel antifungal treatments for Aspergillus keratitis.

PURPOSE: To establish polyhexamethylene biguanide (PHMB) as an effective treatment for Aspergillus keratitis in a novel murine model. To determine the ability of the calcineurin inhibitors tacrolimus (FK506) and cyclosporine A (CSA) to enhance the activity of PHMB, amphotericin B (AMB), and voriconazole (VCZ) against Aspergillus keratitis. IN VITRO STUDIES: Broth antifungal susceptibility tests were performed with PHMB, AMB, VCZ, and FK506, individually and in combination against Aspergillus fumigatus. Minimum inhibitory concentrations (MIC) and fractional inhibitory concentration index (FICI) values were used to analyze antifungal activity. In vivo studies: A novel murine model was created to establish Aspergillus keratitis. Infected mice were randomly assigned to treatment groups receiving saline, CSA, AMB, VCZ, PHMB, AMB+CSA, VCZ+CSA, or PHMB+CSA. An ophthalmologist blinded to the treatment groups assessed disease severity daily based on a grading scale. The mean end change in disease score was compared between groups. IN VITRO STUDIES: FK506 in combination with PHMB, VCZ, or AMB enhanced fungal growth inhibition. FICI values showed an additive effect between FK506 and PHMB, AMB, or VCZ. PHMB monotherapy eliminated Aspergillus growth starting at 4 µg/mL. In vivo studies: All treatment groups showed a significant improvement in disease score compared to the control group. CSA significantly worsened VCZ activity against Aspergillus keratitis. CONCLUSIONS: PHMB is an effective inhibitor of Aspergillus growth. Further investigation of the role of calcineurin inhibitors in the treatment for Aspergillus keratitis is warranted.

Riboflavin and ultraviolet light a therapy as an adjuvant treatment for medically refractive Acanthamoeba keratitis: report of 3 cases.

PURPOSE: To present the first 3 cases of Acanthamoeba keratitis (AK), unresponsive to medical treatment, that were successfully treated with a novel adjunctive therapy using ultraviolet light A (UVA) and riboflavin (B2). DESIGN: Interventional case series. PARTICIPANTS: Two patients with confirmed AK and 1 patient with presumptive AK, which were all refractive to multidrug conventional therapy. INTERVENTION: Two treatment sessions involving topical application of 0.1% B2 solution to the ocular surface combined with 30 minutes of UVA irradiation focused on the corneal ulcer. MAIN OUTCOME MEASURES: Clinical examination by slit lamp, confocal microscopy, and histopathology, when available. RESULTS: All patients in these series showed a rapid reduction in their symptoms and decreased ulcer size after the first treatment session. The progress of the clinical improvement began to slow after 1 to 3 weeks of the first application and was then renewed after the second application. All ancillary signs of inflammation mostly resolved after the second treatment session. The ulcers in all patients continued to decrease and were closed within 3 to 7 weeks of the first application. Two patients developed dense central corneal scars, and penetrating keratoplasty was performed for visual rehabilitation. Histopathologic examination of the excised tissue revealed no Acanthamoeba organisms. The remaining patient had no symptoms or signs of infection, both clinically and by confocal microscopy, and was left with a semitransparent eccentric scar that did not affect visual acuity. CONCLUSIONS: The adjunctive use of UVA and B2 therapy seems to be a possible alternative for selected cases of medication-resistant AK.