Superficial veterinary mycoses

Effects of Outdoor-Grown Royal Sun Medicinal Mushroom Agaricus brasiliensis KA21 (Agaricomycetes) Fruiting Body on Canine Malassezia Dermatitis

Brazil-grown outdoor-cultivated Agaricus brasiliensis KA21 fruiting body (KA21) significantly increases the production of serum anti-beta-glucan antibody. Therefore, KA21 ingestion may be useful for the prevention and alleviation of fungal infections. This study aimed to determine the effects of KA21 in fungal infections in animals. KA21 was administered to nine dogs infected with Malassezia. Notably, the anti-beta-glucan antibody titer remained unchanged or tended to decrease in the oral steroid arm, whereas in the non-steroid arm, antibody titer increased in almost all animals after KA21 ingestion. Dogs showing improved clinical symptoms exhibited increased anti-beta-glucan antibody titers. The results of this study suggest that KA21 ingestion may alleviate the symptoms of Malassezia and other fungal infections and that continuous ingestion may help prolong recurrence-free intervals. Additionally, the ingestion of KA21 during oral steroid dosage reduction or discontinuation may enable smoother steroid withdrawal.

Hedgehog Dermatophytosis: Understanding Trichophyton erinacei Infection in Pet Hedgehogs and Its Implications for Human Health

Pet hedgehogs, which are increasingly favoured companions, have garnered attention due to their potential as carriers of zoonotic diseases. These small insectivorous mammals, native to Europe, Asia, and Africa, are commonly kept as pets. The encroachment of humans into hedgehog habitats has brought these animals closer to people, raising concerns about disease transmission. This article reviews the current knowledge regarding zoonotic disease associated with pet hedgehogs, with a particular focus on mycotic infections caused by Trichophyton erinacei. Data from various regions and hedgehog species are synthesised to assess the significance of pet hedgehogs as potential reservoirs and transmitters of zoonotic pathogens. Our study highlights the importance of understanding the health risks associated with pet hedgehogs and underscores the need for continued research to mitigate zoonotic disease transmission from these potentially disease-carrying companions.

In Vitro Activity of Farnesol against Malassezia pachydermatis Isolates from Otitis Externa Cases in Dogs

Chronic otitis externa of dogs is a significant problem due to the prevalence and complexity of the treatment of such animals. There is evidence that in 60-80% of cases of infectious diseases microorganisms located in the biofilm phenotype play the main role. Microorganisms in the biofilm phenotype have a number of advantages, the most significant of which is considered to be increased resistance to various external factors. Among them, a special place is occupied by resistance to antibiotics. In recent decades, research has been conducted at an increasing scale on the role of biofilm infections in various pathologies in veterinary medicine. The etiology and therapy of dog otitis externa caused by Malassezia pachydermatis biofilm has not been fully studied. This is why we consider relevant the scientific and practical aspects of research on the etiology and therapy of dog otitis externa from the position of biofilm infection. In this work, it has been statistically proven that there is a relationship between the optical density of Malassezia pachydermatis biofilms and their sensitivity to drugs, and this relationship is statistically significant. In addition, we have demonstrated that Farnesol has a good antibiofilm effect at a concentration of more 1.6 μM/mL (24% OD decrease of biofilm), and its highest antibiofilm effect (71-55%-more than a half) was observed at a concentration of 200-12.5 μM/mL.

ERG11 Gene Variability and Azole Susceptibility in Malassezia pachydermatis

Malassezia pachydermatis is part of the normal skin microbiota of various animal species but under certain circumstances becomes an opportunistic pathogen producing otitis and dermatitis. Commonly these Malassezia diseases are effectively treated using azoles. However, some cases of treatment failure have been reported. Alterations in the ERG11 gene have been associated with in vitro azole resistance in M. pachydermatis. In the present study, in vitro antifungal susceptibility of 89 different strains of M. pachydermatis isolated from different animal species and health status was studied. The susceptibility to fluconazole (FLZ), itraconazole (ITZ), ketoconazole and amphotericin B was tested by a disk diffusion method and 17 strains were also subjected to an ITZ E-test. Mueller-Hinton supplemented with 2% glucose and methylene blue was used as culture medium in both susceptibility assays. Multilocus sequence typing was performed in 30 selected strains using D1D2, ITS, CHS2 and β-tubulin genes. Also, ERG11 gene was sequenced. The four antifungals tested were highly effective against most of the strains. Only two strains showed no inhibition zone to antifungals and a strain showed an increased MIC to ITZ. The study of the ERG11 sequences revealed a high diversity of DNA sequences and a total of 23 amino acid substitutions, from which only two have been previously described. Also, three deleterious substitutions (A302T, G459D and G461D) previously associated with azole resistance in this yeast were recovered. A correlation between certain genotypes and ERG11 mutations was observed. Some of the ERG11 mutations recovered were correlated with a reduced susceptibility to azoles.

Development, preparation, and evaluation of a novel non-adjuvanted polyvalent dermatophytes vaccine

Ringworm is a worldwide distributed contagious disease infecting both man and animals that constitute an economic, zoonotic, and health problem concern all over the world. During the last decade, attention has been directed to vaccination as an ideal approach to the control of such diseases. In the present study, non-adjuvanted polyvalent vaccines were prepared from locally isolated hot and virulent dermatophyte species, namely Trichophyton verrucosum (T. verrucosum), Trichophyton mentagrophytes (T. mentagrophytes), and Microsporum canis (M. canis) were immunologically evaluated. The prepared vaccine evaluation was focused on the aspects of immunogenicity and protective efficacy using guinea pigs. Both in its living or inactivated forms, the vaccine-induced significant humoral and cell-mediated immune responses and achieve proper protection of guinea pigs against challenging infections with homologous and heterologous dermatophyte strains. On the other hand, investigations on dermatophyte exo-keratinases showed that it was better produced and more expressed in a mineral-based medium containing pure keratin (3 g/L) than in the same medium with human hair supplementation (2.6 g/L). The maximum dermatophyte productivity of exo-keratinases was found to be between 18 and 21 days post-incubation. Using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), two fractions with molecular weights of 40 kDa (fraction I) and 28 kDa (fraction II) have been identified in the culture filtrate of the three involved dermatophyte species. Both fractions demonstrated keratinolytic activity. The specific activity of the isolated keratinases (number of Keratinase units (KU)/mg protein) was stronger in fraction I, where it reached 18.75, 15.38, and 14 KU/mg protein as compared to 12.9, 8.74, and 12 KU/mg protein in fraction II of T. verrucosum, T. mentagrophytes, and M. canis, respectively. The dermatophyte exo-keratinases proved to be immunogenic as they stimulated high keratinase-specific antibody titers and induced strong delayed skin hypersensitivity reactions in vaccinated animals. Anti-keratinase-specific IgG was detected in sera of guinea pigs immunized with the inactivated or living polyvalent dermatophyte vaccines by a homemade enzyme-linked immunosorbent assay (ELISA) using dermatophyte exo-keratinases as coating antigen. The intradermal injection of dermatophyte exo-keratinases induced specific delayed skin reactions in guinea pigs immunized with the inactivated or the living polyvalent dermatophyte vaccines. The intradermal injection of dermatophyte exo-keratinases in the control non-sensitized guinea pigs was associated with itching, swelling, and bloody scar formation, however, no skin indurations were formed. The development of those post-exo-keratinases injection reactions in the control non-sensitized apparently healthy guinea pigs group, suggests an exo-keratinases possible role in the pathogenesis of dermatophytosis.

Production and Quantification of Virulence Factors in Malassezia Species

Seventy-seven strains of Malassezia were included in this study. Biofilm and hydrolytic enzyme production were studied by using specific solid media. The Real-Time reverse transcriptase qPCR method was applied to determine the overexpression of genes encoding the extracellular enzymes. All included Malassezia species produced biofilms. No statistically significant difference was observed between Malassezia species in biofilm formation (p = 0.567). All Malassezia species produced lipase, and 95% of Malassezia globosa showed a strong enzymatic activity (Pz = 0.55 ± 0.02). A statistically significant difference was observed between the mean keratinase indices of Malassezia slooffiae and the other Malassezia species (p = 0.005). The overexpression of one or more genes was observed in 100% of strains isolated from patients with folliculitis, 87.5% - with pityriasis versicolor, and 57.14% of the control group isolates. A statistically significant difference in the lipase gene expression (p = 0.042) was between the strains from patients with folliculitis and the control group. This investigation provides more information about the frequency of the production of the major enzymes considered virulence factors of Malassezia species. Interestingly, the overexpression of one or more genes was observed in strains isolated from patients with Malassezia disorders.

Concurrent Chorioptic Mange and Dermatophytosis in Dairy Goats: A Case Report

A concurrent chorioptic mange and dermatophytosis outbreak occurred in a goat flock in northwestern Italy. Sanitation of the flock was obtained following pour-on eprinomectin application at a dose of 1 mg/kg; enilconazole was used for environmental disinfection against dermatophyte spores.

Effects of Coleus amboinicus L. Essential Oil and Ethanolic Extracts on Planktonic Cells and Biofilm Formation of Microsporum canis Isolated from Feline Dermatophytosis

Microsporum canis is an important zoonotic fungus that causes dermatophytosis in domestic animals and their owners. Domestic cats are the primary reservoir for M. canis. Antifungal drugs frequently produce adverse effects on the host animal, increasing the demand for novel alternative treatments derived from nature. We evaluated the antifungal activity of Coleus amboinicus essential oil (CEO) and ethanolic extracts (CEE) against M. canis in planktonic and biofilm growth. Twelve clinical isolates of M. canis were identified in feline dermatophyte samples. Using GC-MS, 18 compounds were identified in CEO, with carvacrol being the major constituent. HPLC analysis of CEE revealed that it contained rosmarinic acid, apigenin, and caffeic acid. The planktonic growth of all M. canis isolates was inhibited by C. amboinicus extracts. The minimum inhibitory concentration at which ≥50% of the isolates were inhibited (MIC₅₀) was 128 µg/mL (32-256 µg/mL) for both CEO and CEE. The MIC₉₀ values of CEO and CEE were 128 and 256 µg/mL, respectively. CEO at MIC (128 µg/mL) and 2× MIC (256 µg/mL) significantly inhibited the biofilm formation of weak, moderate, and strong biofilm-producing M. canis. CEE at 2× MIC (256 µg/mL) significantly inhibited the biofilm formation of all isolates. Overall, C. amboinicus extracts inhibited planktonic growth and exhibited a significant antibiofilm effect against M. canis. Thus, C. amboinicus is a potential source of natural antifungal compounds.

Emerging Fungal Infections: from the Fields to the Clinic, Resistant Aspergillus fumigatus and Dermatophyte Species: a One Health Perspective on an Urgent Public Health Problem

Purpose of Review

For this review, we use a One Health approach to examine two globally emerging public health threats related to antifungal drug resistance: triazole-resistant Aspergillus fumigatus infections, which can cause a life-threatening illness in immunocompromised hosts, and antifungal-resistant dermatophytosis, which is an aggressive skin infection caused by dermatophyte molds. We describe the state of current scientific knowledge and outline necessary public health actions to address each issue.

Recent Findings

Recent evidence has identified the agricultural use of triazole fungicides as an important driver of triazole-resistant A. fumigatus infections. Antifungal-resistant dermatophyte infections are likely driven by the inappropriate use of antifungal drugs and antibacterial and corticosteroid creams.

Summary

This review highlights the need for a One Health approach to address emerging antifungal resistant infections, emphasizing judicious antifungal use to preserve available treatments; strengthened laboratory capacity to identify antifungal resistance; and improved human, animal, and environmental surveillance to detect emerging resistance, monitor trends, and evaluate the effectiveness of efforts to decrease spread.

Detection of Microsporum canis and Trichophyton mentagrophytes by loop-mediated isothermal amplification (LAMP) and real-time quantitative PCR (qPCR) methods

BACKGROUND

Dermatophytes are infectious zoonotic fungal agents that are common in animals worldwide. A new loop-mediated isothermal amplification (LAMP) method and quantitative (q)PCR can be used for identifying these agents. Both methods have high specificity and sensitivity, and are simple and quick to use.

HYPOTHESIS/OBJECTIVES

To develop a LAMP and a rapid multiplex qPCR method for detecting Microsporum canis and Trichophyton mentagrophytes, which are the most common fungal species isolated from cats and dogs.

MATERIAL AND METHODS

Both methods targeted the CHS-1 gene. Their specificity and sensitivity were tested using 64 M. canis and 44 T. mentagrophytes field strains. The validation of the methods was performed using 250 clinical fungal-positive hair samples.

RESULTS

The specificity value was 100% for both methods. For LAMP, the sensitivity value was 96.9% for M. canis and 93.2% for T. mentagrophytes. For qPCR, the sensitivity values were 98.4% for M. canis and 97.7% for T. mentagrophytes. Similar specificity and sensitivity results were obtained from the validation study using 250 clinical hair samples. LAMP and multiplex qPCR took 30 and 45 min (respectively) for both targets. The limit of detection (LOD) assays for both targets were 10 and 1 spore/mL for LAMP and multiplex qPCR, respectively.

CONCLUSION

These findings demonstrate that the LAMP and multiplex qPCR methods targeting CHS-1 gene developed in this study can be used both for point-of-care testing and in the laboratory for detecting M. canis and T. mentagrophytes with high specificity and sensitivity with an internal control.

Characterization and Antidermatophyte Activity of Henna Extracts: A Promising Therapy for Humans and Animals Dermatophytoses

Dermatophytoses representing a major global health problem and dermatophyte species with reduced susceptibility to antifungals are increasingly reported. Therefore, we investigated for the first time the antidermatophyte activity and phytochemical properties of the sequential extracts of the Egyptian privet Henna (Lawsonia inermis) leaves. Total phenolic content (TPC), total flavonoids (TF), and antioxidant activity of chloroform, diethyl ether, acetone, ethanol 80%, and aqueous extracts were evaluated. The antifungal activity of henna leaves extracts (HLE) toward 30 clinical dermatophytes isolates, including Trichophyton mentagrophytes, Microsporum canis, and T. rubrum, was determined. Morphological changes in hyphae were investigated using scanning electron microscopy (SEM) analysis. Following the polarity of ethanol and acetone, they exhibited distinct efficiency for the solubility and extraction of polyphenolic polar antioxidants from henna leaves. Fraxetin, lawsone, and luteolin-3-O-glucoside were the major phenolic compounds of henna leaves, as assessed using high-performance liquid chromatography analysis. A high and significant positive correlation was found between TPC, TF, the antioxidants, and the antidermatophyte activities of HLE. Acetone and ethanol extracts exhibited the highest antifungal activity toward the tested dermatophyte species with minimum inhibitory concentration (MIC) ranges 12.5-37.5 and 25-62.5 µg/mL, respectively. Structural changes including collapsing, distortion, inflating, crushing of hyphae with corrugation of walls, and depressions on hyphal surfaces were observed in SEM analysis for dermatophyte species treated with MICs of griseofulvin, acetone, and ethanol extracts. In conclusion, acetone and ethanolic extracts of henna leaves with their major constituent fraxetin exhibited effective antifungal activity toward dermatophyte species and may be developed as an alternative for dermatophytosis treatment. These findings impart a useful insight into the development of an effective and safe antifungal agent for the treatment of superficial fungal infections caused by dermatophytes.

Prevalence of Ringworm in Dairy Cows at Baturraden Indonesia

Ringworm is one of the forms of zoonotic dermatitis caused by dermatophyte fungus that can be suffered by dairy cows. The disease usually does not cause death; however, it can decrease the productivity of dairy cows. This study aimed to determine the prevalence of dermatitis in dairy cows at BBPTUHPT Baturraden, Indonesia. This retrospective study was based on medical record data from January‒October 2021. Cows were diagnosed with ringworm if they show any clinical symptoms of grayish-white lesions or dark round-shaped patches with crusts, scales, hyperkeratosis, and alopecia of various sizes. The data obtained were analyzed descriptively. The results showed that cases of ringworm in January‒October 2021, had occurred in 114 out of the 1,099 dairy cows. Ringworm occurred throughout the year, and the 3 months with the most cases are March (36 cases), February (18 cases), and September (15 cases). To conclude, ringworm occurred in dairy cows at BBPTUHPT Baturraden, Indonesia from January to October 2021 with a prevalence of 10.4%.

Presumptive Zoonotic Kerion by Nannizzia gypsea: Case Report

Nannizzia gypsea (formerly Microsporum gypseum) belongs to geophilic dermatophytes, fungi involved in keratin degradation in the soil; however, they are also found in dogs and cats. Transmission to humans can occur directly by contact with soil, but indirect transmission via domestic animals is reported too. The exact source of the infection is usually difficult to assess and in most cases only hypothesised and rarely investigated. This case report describes a kerion caused by N. gypsea in a 2-year-old boy, where the contagion was probably secondary to domestic healthy carrier dogs. A “One-Health” approach involving human dermatologists and veterinarians, combined with the use of conventional and molecular-based techniques, allowed tracing of the epidemiological chain and managing of not only the treatment but also the prevention of a recurrence. The child's lesion began to regress after about 8 weeks of treatment with both systemic and topical therapy, while the dogs were given chlorhexidine and miconazole baths. No recurrences nor new infections occurred, demonstrating the effectiveness of the strategies used.

Detection of subtilisin 3 and 6 in skin biopsies of cattle with clinically manifested bovine ringworm

Trichophyton (T.) verrucosum is a highly pathogenic dermatophyte causing zoonotic bovine ringworm that is transmissible to humans. The virulence factors subtilisin (Sub)3 and Sub6 are discussed to contribute to disease manifestation but no protein expression study is available for T. verrucosum. We used customized antibodies (against Trichophyton-species, Sub3 and Sub6) to examine skin biopsies of infected cattle via immunofluorescence stainings. Both virulence factors Sub3 and 6 were solely expressed by conidia and not only found in epidermal but also in dermal and hair structures. The anti-T-antibody reliably detected the fungus and proved more sensitive compared to histological stains.

LAY SUMMARY

We examined the zoonotic dermatophyte Trichophyton (T.) verrucosum in bovine skin and studied two important virulence factors called subtilisin (Sub)3 and Sub6 that T. verrucosum produces and secretes using immunolabeling.

In vitro activity of lactoferricin solution against Malassezia pachydermatis from otitis externa in dogs and cats

BACKGROUND

Malassezia pachydermatis is a commensal organism of the skin, yet it may induce dermatitis and/or otitis. Lactoferricin (Lfcin) is an antimicrobial peptide obtained by the pepsin-mediated digestion of lactoferrin, a multifunctional innate-defence milk protein. The antibacterial activity of Lfcin is thought to cause alteration of bacterial membrane permeability, thus inducing cell death.

OBJECTIVES

The aim of this study was to evaluate in vitro antifungal activity of different dilutions of Lfcin solution against M. pachydermatis strains isolated from ears of dogs and cats with otitis externa.

METHODS AND MATERIALS

Fifty clinical Malassezia isolates from 40 dogs and 10 cats were tested. A dilution method in microtitre plates was used starting with a 20% Lfcin water solution. The different dilutions were 2:1 (13.3%), 1:1 (10%), 1:2 (6.7%), 1:5 (3.3%) and 1:10 (1.8%). Results were expressed as the value at which the growth of 50% (minimal fungicidal concentration MFC₅₀ ) and 90% (MFC₉₀ ) of yeast cells was inhibited.

RESULTS

All strains showed susceptibility to 20% Lfcin solution (100%). With 1:5 and 1:10 dilutions corresponding to 3.3% and 1.8% Lfcin solutions, all strains showed resistance. The MFC₅₀ and MFC₉₀ values were observed at 13.3% and 20% Lfcin solutions.

CONCLUSIONS AND CLINICAL RELEVANCE

The results indicated that Lfcin solution exhibits the antimicrobial activity specific to antimicrobial peptides. In particular, the 20% solution can be effective in killing M. pachydermatis isolated strains. Some susceptibilities also are evident at lower concentrations of ≤6.7% for four strains.

Superficial mycoses, a matter of concern: Global and Indian scenario-an updated analysis

Superficial mycoses of skin, nails and hair are among the common fungal infections. They are caused by dermatophytes, non-dermatophyte moulds, yeasts and yeast-like fungi. Such fungal infections are widespread all over the world and are predominant in tropical as well as subtropical regions. Environmental factors, such as warm, humid and pitiable hygienic conditions, are conducive for their growth and proliferation. Although it does not cause mortality, it is known to be associated with excessive morbidity which may be psychological or physical. This affects the quality of life of the infected individuals which leads to a negative impact on their occupational, emotional and social status. Such infections are increasing on a global scale and, therefore, are of serious concern worldwide. This review article covers the global and Indian scenario of superficial mycoses taking into account the historical background, aetiological agents, prevalence, cultural and environmental factors, risk factors, pathogenesis and hygienic practices for the prevention of superficial mycoses.

Research Relevant Background Lesions and Conditions: Ferrets, Dogs, Swine, Sheep, and Goats

Animal models provide a valuable tool and resource for biomedical researchers as they investigate biological processes, disease pathogenesis, novel therapies, and toxicologic studies. Interpretation of animal model data requires knowledge not only of the processes/diseases being studied but also awareness of spontaneous conditions and background lesions in the model that can influence or even confound the study results. Species, breed/stock, sex, age, anatomy, physiology, diseases (noninfectious and infectious), and neoplastic processes are model features that can impact the results as well as study interpretation. Here, we review these features in several common laboratory animal species, including ferret, dog (beagle), pig, sheep, and goats.

Use of Essential Oils in Veterinary Medicine to Combat Bacterial and Fungal Infections

Essential oils (EOs) are secondary metabolites of plants employed in folk medicine for a long time thanks to their multiple properties. In the last years, their use has been introduced in veterinary medicine, too. The study of the antibacterial properties of EOs is of increasing interest, because therapies with alternative drugs are welcome to combat infections caused by antibiotic-resistant strains. Other issues could be resolved by EOs employment, such as the presence of antibiotic residues in food of animal origin and in environment. Although the in vitro antimicrobial activity of EOs has been frequently demonstrated in studies carried out on bacterial and fungal strains of different origins, there is a lack of information about their effectiveness in treating infections in animals. The scientific literature reports some studies about in vitro EOs' activity against animal clinical bacterial and fungal isolates, but in vivo studies are very scanty. The use of EOs in therapy of companion and farm animals should follow careful studies on the toxicity of these natural products in relation to animal species and route of administration. Moreover, considering the different behavior of EOs in relation to both species and strain pathogen, before starting a therapy, an aromatogram should be executed to choose the oil with the best antimicrobial activity.

Analysis on the pathogenic fungi in patients with superficial mycosis in the Northeastern China during 10 years

This study analyzed the infection of superficial mycosis and the relationship between the distribution characteristics of pathogenic fungi and age, time and sex in Northeast China in the past 10 years. We would like to provide a theoretical basis for the diagnosis and treatment of related diseases. From December 2008 to December 2018, 5,374 superficial mycoses from Northeast China were selected. The fungal species were identified by fungal microscopy, fungal culture, and species identification. Besides, the relationship between sex, age, time and the distribution of superficial mycosis and pathogenic fungi was analyzed. Among the 5,374 patients, the top three infections were tinea pedis (n=1,538, 28.62%), tinea cruris (n=1,018, 18.94%) and tinea corporis (n=938, 17.45%). The top three pathogens were Trichophyton rubrum (n=2,849, 48.65%), Trichophyton mentagrophytes (n=947, 16.14%) and Candida spp. (n=804, 13.70%). The main pathogenic fungi were dermatophytes. The age group with the highest incidence of tinea capitis was children (n=372, 6.92%). The highest incidence rate of tinea pedis was in 31-69-year adults (n=905, 16.84%); Malassezia mainly affects young people aged 15-30. Yeast and mold mostly invade the elderly patients >60 years old. The incidence of tinea cruris, tinea pedis and tinea corporis in male patients was higher than that in female patients. The incidence of onychomycosis in female patients was higher than that in male patients (P<0.05). The isolation rate of Candida, Mold, Microsporum canis, Malassezia and Sporothrix increased year by year, while that of Trichophyton rubrum, Trichophyton mentagrophyte, Trichophyton schoenleinii and Epidermophyton floccosum decreased. From December 2008 to December 2018, dermatophytes were the main pathogens of superficial mycosis in Northeast China. The distribution of disease species and pathogenic fungi varied in different gender, age and time.

Novel Antimicrobial Peptide from Temporin L in The Treatment of Staphylococcus pseudintermedius and Malassezia pachydermatis in Polymicrobial Inter-Kingdom Infection

Interkingdom polymicrobial diseases are caused by different microorganisms that colonize the same niche, as in the case of yeast-bacteria coinfections. The latter are difficult to treat due the absence of any common therapeutic target for their elimination, both in animals and humans. Staphylococcus pseudintermedius and Malassezia pachydermatis belong to distinct kingdoms. They can colonize the same skin district or apparatus being the causative agents of fastidious pet animals’ pathologies. Here we analysed the antimicrobial properties of a panel of 11 peptides, derived from temporin L, against Malassezia pachydermatis. Only peptide 8 showed the best mycocidal activity at 6.25 μM. Prolonged application of peptide 8 did not cause M. pachydermatis drug-resistance. Peptide 8 was also able to inhibit the growth of Staphylococcus pseudintermedius, regardless of methicillin resistance, at 1.56 μM for methicillin-susceptible S. pseudintermedius (MSSP) and 6.25 μM for methicillin-resistant S. pseudintermedius (MRSP). Of interest, peptide 8 increased the susceptibility of MRSP to oxacillin. Oxacillin MIC value reduction was of about eight times when used in combination with peptide 8. Finally, the compound affected the vitality of bacteria embedded in S. pseudintermedius biofilm. In conclusion, peptide 8 might represent a valid therapeutic alternative in the treatment of interkingdom polymicrobial infections, also in the presence of methicillin-resistant bacteria.

Biology, diagnosis and treatment of Malassezia dermatitis in dogs and cats Clinical Consensus Guidelines of the World Association for Veterinary Dermatology

BACKGROUND

The genus Malassezia is comprised of a group of lipophilic yeasts that have evolved as skin commensals and opportunistic cutaneous pathogens of a variety of mammals and birds.

OBJECTIVES

The objective of this document is to provide the veterinary community and other interested parties with current information on the ecology, pathophysiology, diagnosis, treatment and prevention of skin diseases associated with Malassezia yeasts in dogs and cats.

METHODS AND MATERIAL

The authors served as a Guideline Panel (GP) and reviewed the literature available prior to October 2018. The GP prepared a detailed literature review and made recommendations on selected topics. The World Association of Veterinary Dermatology (WAVD) Clinical Consensus Guideline committee provided guidance and oversight for this process. The document was presented at two international meetings of veterinary dermatology societies and one international mycology workshop; it was made available for comment on the WAVD website for a period of six months. Comments were shared with the GP electronically and responses incorporated into the final document.

CONCLUSIONS AND CLINICAL IMPORTANCE

There has been a remarkable expansion of knowledge on Malassezia yeasts and their role in animal disease, particularly since the early 1990's. Malassezia dermatitis in dogs and cats has evolved from a disease of obscurity and controversy on its existence, to now being a routine diagnosis in general veterinary practice. Clinical signs are well recognised and diagnostic approaches are well developed. A range of topical and systemic therapies is known to be effective, especially when predisposing factors are identified and corrected.

Antifungal Resistance Regarding Malassezia pachydermatis: Where Are We Now?

Malassezia pachydermatis is a yeast inhabiting the skin and ear canals in healthy dogs. In the presence of various predisposing conditions it can cause otitis and dermatitis, which are treated with multiple antifungal agents, mainly azole derivatives. This manuscript aims to review the available evidence regarding the occurrence of resistance phenomena in this organism. Various findings support the capacity of M. pachydermatis for developing resistance. These include some reports of treatment failure in dogs, the reduced antifungal activity found against yeast isolates sampled from dogs with exposure to antifungal drugs and strains exposed to antifungal agents in vitro, and the description of resistance mechanisms. At the same time, the data reviewed may suggest that the development of resistance is a rare eventuality in canine practice. For example, only three publications describe confirmed cases of treatment failure due to antifungal resistance, and most claims of resistance made by past studies are based on interpretive breakpoints that lack sound support from the clinical perspective. However, it is possible that resistant cases are underreported in literature, perhaps due to the difficulty of obtaining a laboratory confirmation given that a standard procedure for susceptibility testing of M. pachydermatis is still unavailable. These considerations highlight the need for maintaining surveillance for the possible emergence of clinically relevant resistance, hopefully through a shared strategy put in place by the scientific community.

Clinical-dermatological, histological abnormalities and prevalence of Trypanosoma caninum and Leishmania infantum in dogs from Midwest region of Brazil

Leishmania infantum is a trypanosomatid that causes parasitic dermatopathy in dogs. Trypanosoma caninum is another trypanosomatid, which infects the skin of dogs, although cutaneous abnormalities are absent. This study aimed to investigate the occurrence of T. caninum infection and its associated cutaneous and histological changes and compare it with the occurrence of L. infantum infection in dogs. The study included 150 dogs, of which T. caninum infection was identified in 3 (2%) and L. infantum infection in 15 (10%) of them, with no association (p>0.05) of these infections with the breed, gender, age, or cutaneous abnormalities. The cutaneous abnormalities were based on 1 (4.8%) and 12 (57.1%) dogs infected by T. caninum and L. infantum, respectively. The dermatohistopathological abnormalities in the dogs infected with T. caninum included mild perivascular lymphohistioplasmacytic infiltrates in the clinically asymptomatic ones, while in those with dermatological abnormalities, acanthosis, epidermal orthokeratotic hyperkeratosis, melanomacrophages, and co-infection with Microsporum sp. and Trichophyton sp. were observed. InL. infantum infected, the histopathological findings included chronic granulomatous inflammatory infiltrates and structures compatible with amastigotes. Despite the low frequency of T. caninum infection, our findings suggest that this trypanosomatid, unlike L. infantum, does not cause any macroscopic skin abnormalities.

Antifungal in vitro Activity of Essential Oils against Clinical Isolates of Malassezia pachydermatis from Canine Ears: A Report from a Practice Laboratory

BACKGROUND

The yeast Malassezia pachydermatis is a commensal but also the most isolated pathogenic yeast in canine otitis externa. Essential oils (EOs) exhibit antimicrobial activity and thus could be an alternative for treatment of otitis.

OBJECTIVE

The aim of this study was to analyse the in vitro efficacy of EOs against M. pachydermatis isolates from canine ears.

MATERIALS AND METHODS

Twenty-two EOs were tested for their in vitro activity against 15 M. pachydermatis isolates by agar disc diffusion. In addition, diluted EOs were tested and volatile antifungal activity was analysed by vapour assay.

RESULTS

Most EOs showed in vitro efficacy against M. pachydermatis. A different susceptibility pattern of tested isolates was found. Overall, the most potential EO was lemon grass. Also, cinnamon leaf, clove, manuka, Indian melissa, oregano, palmarosa, and winter savory oil exhibited a strong antifungal activity. Volatile activity was proven by the inhibiting effect in vapour assay.

CONCLUSION

EOs show in vitro activity against M. pachydermatis. This study gives scientific background for the use of EOs in veterinary medicine. Diverse susceptibility patterns of different M. pachydermatis strains emphasise the helpfulness of an aromatogram as one lead for the best choice of an EO for therapy.

In search of the source of dermatophytosis: Epidemiological analysis of Trichophyton verrucosum infection in llamas and the breeder (case report)

During the last few years, the number of cases of Trichophyton verrucosum isolation from humans suffering from mycoses has been constantly increasing, which is correlated with the presence of an increasing number of outdoor breeding farms. Farmers and their families as well as veterinarians and technicians involved in handling the animals are at a higher risk of infection. One of the most important aims of mycological diagnostics is epidemiological analysis. Typically, the history of the disease is not sufficient to indicate reliably and eliminate the outbreak of infection. PCR fingerprinting methods are a useful tool in this type of analysis, which is presented in this study. The main aim is to present diagnostic and epidemiological analyses of dermatophyte isolates from llamas and their breeder. In two llamas, round alopecia sites or ca. 2-cm excoriations covered with thickened scaling epidermis were noticed at the border of the head and neck with a distinct tendency towards hair loss. Tinea unguium was noticed in a nail of the breeder's right hand. Direct analysis of the material from the clinical lesions revealed the presence of arthrospores. The macro- and micromorphology of the isolates were homogeneous and characteristic for T. verrucosum. The identification analysis based on the ITS sequences confirmed the previous morphological diagnostic examination. The MP-PCR and MSP-PCR analysis indicated high invariability of the genomes of the strains isolated from the human and animals. The epidemiological research has indicated an identical source of dermatophyte infection in the breeder and the lamas. To sum up, the number of pets and farm animals is increasing and dermatologists should always be informed about possible dermatophyte transmission sources. The possibility of transmission of zoophilic dermatophytes from humans to animals is a suggestion for further analysis; therefore, this type of transmission should be considered in dermatological studies.

In vitro activity of carvacrol, cinnamaldehyde and thymol combined with antifungals against Malassezia pachydermatis

Malassezia pachydermatis is an important opportunistic agent of dermatitis and otitis in dogs. M. pachydermatis is generally treated with topical therapies using combinations of antifungal, antimicrobial and anti-inflammatory agents. We investigated the in vitro activities of carvacrol (CRV), cinnamaldehyde (CIN) and thymol (THY) alone and in combination with antifungal agents (fluconazole, itraconazole, ketoconazole, clotrimazole, miconazole, terbinafine and nystatin) against M. pachydermatis. The assays were performed according to the Clinical and Laboratory Standards Institute (CLSI), using Sabouraud dextrose broth and checkerboard microdilution. The mean fractional inhibitory concentration index (FICI) showed primary synergies for the combinations carvacrol+nystatin, thymol+nystatin, and carvacrol+miconazole (80%). In conclusion, the results obtained indicate that the phytochemicals tested showed relevant in vitro anti-M. pachydermatis activity. Future in vivo experiments are needed to elucidate the safety and therapeutic potential of these combinations.

PCR-terminal restriction fragment length polymorphism for direct detection and identification of dermatophytes in veterinary mycology

The biological diagnosis of dermatophytosis in veterinary medicine usually relies on direct microscopic examination and inoculation of the samples on appropriate culture media. However, identification of dermatophytes needs expertise, and cultures which require from days to weeks to be conclusive, may lack of sensitivity because of the quite common overgrowth of contaminants. Here we developed a polymerase chain reaction (PCR) assay based on terminal restriction fragment length polymorphism (TRFLP), which may improve sensitivity of the biological diagnosis and reduce the delay for initiation of treatment. This study was first conducted on pure cultures of various dermatophytes (27 species), yeasts (14 species) and moulds (45 species). After DNA extraction, the internal transcribed spacer (ITS)-28S region of ribosomal DNA was amplified with primers targeting specifically pathogenic dermatophytes, and species of interest were identified by TRFLP with appropriate restriction enzymes. After validation, this assay was applied to veterinary samples and results were compared to those obtained by direct microscopic examination and cultures. All target species were correctly identified, and none of the yeast or mould species was amplified, demonstrating specificity of the assay. Regarding clinical samples, the causative agent was detected by PCR-TRFLP from 97.1% of the samples with both positive direct microscopic examination and cultures. No dermatophytes were detected when both conventional tests were negative. PCR-TRFLP developed here demonstrated to be highly sensitive and specific, allowing rapid detection and direct identification of dermatophytes in veterinary practice. Therefore, this assay is especially suitable for the biological diagnosis of dermatophytosis in different animal species.

Interleukin-17 in Antifungal Immunity

The field of IL-17 biology has received much attention over the last decade owing to the pathogenic role of this cytokine in psoriasis and other autoinflammatory disorders and the successful implementation of IL-17-targeting therapies in patients suffering from these diseases. IL-17-mediated pathologies are contrasted by the important host beneficial effects of this cytokine. IL-17 is essential for regulating microbial colonization in barrier tissues. Rare congenital defects in the IL-17 pathway exemplify the relevance of IL-17 in protective immunity against the opportunistic fungal pathogen C. albicans. However, more recently, evidence is accumulating that IL-17 can also provide protection against fungi other than C. albicans. Importantly, protective IL-17 responses directed against commensal fungi can, under certain conditions, promote inflammation with detrimental consequences for the host, thereby assigning fungi a new role as disease-promoting factors apart from their role as potential infectious agents.

Therapy of Non-Dermatophytic Mycoses in Animals

This review focuses on aspects of antimycotic therapy specific to veterinary medicine. In the first part, drug availability, limited mostly by economic consideration but also by clinical applicability and specific adverse effects, is described for polyenes, 5 fluorocytosine, azoles, echinocandins and terbinafine. In the second part, current knowledge and experience in the treatment of selected fungal infections are overviewed. These mycoses include disseminated mold infections in small animals (dogs and cats) and avian species, upper respiratory tract infections of small animals (sino-nasal and sino-orbital aspergillosis) and horses (guttural pouch mycosis), eumycetoma, infections caused by dimorphic fungi, (blastomycosis, histoplasmosis, coccidioidomycosis, paracoccidioidomycosis and sporothrichosis) and by yeasts and yeast-like microorganism (Cryptococcus spp. and Malassezia pachydermatis).

An experimental murine model of otitis and dermatitis caused by Malassezia pachydermatis

We report a malasseziosis model in immunocompromised Swiss mice. For this model, the mice were immunosuppressed with a combination of cyclophosphamide at 150 mg/kg and hydrocortisone acetate at 250 mg/kg. Two groups were formed according to the site of inoculation. Dermatitis group received an intradermal injection of 5 × 10⁶ cell/mouse at a shaved dorsal region, while the otitis group received the same inoculum in the middle ear. Five animals/group were euthanised at different times, and the skin and ear were histopathologically analysed. During the first euthanasia, which occurred after inoculation, microscopic examination showed that all mice presented budding yeast-like in a tissue sample. The presence of yeasts decreased over time being undetected on the 17th day (dermatitis group) and the 21st day (otitis group) after inoculation. This is the first murine model for malasseziosis that can be useful for evaluating new treatment approaches.

Therapy and Antifungal Susceptibility Profile of Microsporum canis

Microsporum canis is a worldwide diffused zoophilic dermatophyte which causes clinical conditions often characterised by multifocal alopecia, scaling, and circular lesions in many animal species, including humans. A large variety of oral and topical antifungal protocols is available for treating M. canis infection. However, the efficacy of these drugs and treatment protocols is variable, with treatment failure up to 40% of patients possibly due to resistance phenomena. The lack of standardised reference methods for evaluating the antifungal susceptibility of M. canis represents a major hindrance in assessing microbiological resistance in unresponsive clinical cases. Therefore, data about conventional therapy against M. canis and the protocols employed to test the antifungal activity of the most commonly employed drugs (i.e., azoles, polyenes, allylamines, and griseofulvin) have been summarised herein. This article focuses on technical parameters used for antifungal susceptibility tests, their effects on the minimum inhibitory concentration value, as well as their clinical implications.

Assessment of a pan-dermatophyte nested-PCR compared with conventional methods for direct detection and identification of dermatophytosis agents in animals

Conventional direct microscopy with potassium hydroxide (KOH) and culture were found to lack the ability to establish a fast and specific diagnosis of dermatophytosis. A pan-dermatophyte nested-PCR assay was developed using a novel primer pair targeting the translation elongation factor 1-α (Tef-1α) sequences for direct detection and identification of most veterinary relevant dermatophytes in animal samples suspected to dermatophytosis. A total of 140 animal skin and hair samples were subjected to direct microscopy, culture, and ITS-RFLP/ITS-sequencing of culture isolates for the detection and identification of dermatophytosis agents. Nested-PCR sequencing was performed on all the extracted DNAs using a commercial kit after dissolving the specimens by mechanical beating. Nested-PCR was positive in 90% of samples, followed by direct microscopy (85.7%) and culture (75%). The degree of agreement between nested-PCR and direct microscopy (94.4%) was higher than with culture (83.3%). In 105 culture-positive cases, the measures of agreement for the identification of dermatophytosis agents were as follows: 100% between nested-PCR sequencing and ITS-RFLP/ITS-sequencing and 63.8% between nested-PCR sequencing and culture. The developed nested-PCR was faster as well as more sensitive and specific than conventional methods for detection and identification of dermatophytes in clinical samples, which was particularly suitable for epidemiological studies.

Comparison of the pharmacokinetic profiles of two different amphotericin B formulations in healthy dogs

This study was conducted to compare the pharmacokinetic profiles of conventional (Fungizone^® ) and liposomal amphotericin B (AmBisome^® ) formulations in order to predict their therapeutic properties, and evaluate their potential differences in veterinary treatment. For this purpose, twelve healthy mixed breed dogs received both drugs at a dose of 0.6 mg/kg by intravenous infusion over a 4-min period in a total volume of 40 ml. Blood samples were collected at 0, 0.5, 1, 1.5, 2, 3, 4, 8, 12, 24, 48, 72 and 96 hr after dosing, and concentrations of drug in plasma were determined by high-performance liquid chromatography (HPLC). Pharmacokinetics was described by a two-compartment model. Although both formulations were administered at the same doses (0.6 mg/kg), the plasma pharmacokinetics of liposomal amphotericin B differed significantly from those of amphotericin B deoxycholate in healthy dogs (p < .05). Liposomal amphotericin B showed markedly higher peak plasma concentrations (approximately ninefold greater) and higher area under the plasma concentration curve values (approximately 14-fold higher) compared to conventional formulation. It is concluded that AmBisome^® reached higher plasma concentration and lower distribution volume and had a longer half-life compared to Fungizone^® , and therefore, AmBisome^® is reported to be an appropriate and effective choice for the treatment of systemic mycotic infections in dogs.

Advances in Microbiology, Infectious Diseases and Public Health: Fungal Occurrence in the Hair and Skin of Symptomatic Pets in Turin, Italy

Companion animals, often asymptomatic reservoir of fungi, can be important sources of infection in humans, due to the close contact with their owners. The present study was aimed to assess the occurrence of dermatophytes and other fungi isolated from pet dermatological lesions in Turin, Italy. Dermatological specimens were examined for fungal elements by direct microscopy and cultured to detect dermatophytes, other filamentous fungi and yeasts: 247 pets (118 cats, 111 dogs and 18 dwarf rabbits) were positive for fungal detection in culture. Microsporum canis was the most frequent dermatophyte in cats and dogs, whereas Trichophyton mentagrophytes was the most common in rabbits. Among the other fungi, for all examined pets, dematiaceous fungi were the most isolated, followed by Mucorales, penicilli, yeasts and yeast-like fungi, and aspergilli. No gender predisposition was detected for dermatophyte growth; on the contrary, for the other fungi male cats were more susceptible than female. The highest fungal occurrence was recorded in <1-year-old cats for dermatophytes, and in <5-year-old cats and dogs for the other fungi. Autumn was the period associated with a relevant incidence of fungal infection. Finally, fungi were more frequent in non pure-breed cats and in pure-breed dogs. These data underline the importance to timely inform pet owners about the potential health risk of infection caused not only by dermatophytes but also by non-dermatophyte fungi, routinely considered to be contaminants or harmless colonizers, since their role as source of zoonotic infections is not to be excluded.

Trichophyton erinacei in pet hedgehogs in Spain: Occurrence and revision of its taxonomic status

Hedgehogs have increased in popularity as pets in Spain but there are no data of infection rates of this exotic animal with dermatophytes in our country. During the period of 2008-2011 a total of 20 pet hedgehogs (19 African pygmy hedgehogs and 1 Egyptian long-eared hedgehog) suspected of having dermatophytoses were studied. This is the first survey of the occurrence of T. erinacei in household hedgehogs in Spain. The T. erinacei infection rate was 50% (9 out of 19 African pygmy hedgehogs, and the one Egyptian long-eared hedgehog surveyed). Morphological identification of the isolates was confirmed by molecular analysis. All the strains had the same ITS sequence and showed 100% sequence similarity to T. erinacei type strain CBS 511.73 (AB 105793). The Spanish isolates were confirmed as T. erinacei urease positive. On the basis of ITS sequences, T. erinacei is a species close to but separate from the taxa included in the A. benhamiae complex. Review of the current literature on DNA-based methods for identification of species included in this complex has highlighted the urgent need to reach a consensus in species circumscription and classification system accepted by all mycologists.