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Veterinary Microbiology Aug 2020This study analyzed the complex bacterial and fungal microbiota of healthy and clinically affected canine ear and skin samples. A total of 589 canine samples were...
This study analyzed the complex bacterial and fungal microbiota of healthy and clinically affected canine ear and skin samples. A total of 589 canine samples were included: 257 ear swab samples (128 healthy vs. 129 clinically affected) and 332 skin swab samples (172 healthy vs. 160 clinically affected) were analyzed using next-generation sequencing (NGS) to determine both relative and absolute abundances of bacteria and fungi present in the samples. This study highlighted the canine microbiota of clinically affected cases was characterized by an overall loss of microbial diversity, high microbial biomass, with overgrowth of certain members of the microbiota. The observed phenotype of these samples was best described by the combination of both relative and absolute microbial abundances. Compared to healthy samples, 78.3% of the clinically affected ear samples had microbial overgrowth; 69.8% bacterial overgrowth, 16.3% fungal overgrowth, and 7.0% had both bacterial and fungal overgrowth. The most important microbial taxa enriched in clinically affected ears were Malassezia pachydermatis, Staphylococcus pseudintermedius, Staphylococcus schleiferi, and a few anaerobic bacteria such as Finegoldia magna, Peptostreptococcus canis, and Porphyromonas cangingivalis. The anaerobic microbes identified here were previously not commonly recognized as pathogens in canine ear infections. Similar observations were found for skin samples, but yeasts and anaerobes were less abundant when compared to clinically affected cases. Results highlighted herein, signify the potential of NGS-based methods for the accurate quantification and identification of bacterial and fungal populations in diagnosing canine skin and ear infections, and highlight the limitations of traditional culture-based testing.
Topics: Animals; Bacteria; Dog Diseases; Dogs; Ear; Fungi; High-Throughput Nucleotide Sequencing; Microbiota; Otitis; Skin; Skin Diseases, Infectious
PubMed: 32768216
DOI: 10.1016/j.vetmic.2020.108764 -
Frontiers in Cellular and Infection... 2020yeasts are lipid dependent and part of the human and animal skin microbiome. However, they are also associated with a variety of dermatological conditions and even...
yeasts are lipid dependent and part of the human and animal skin microbiome. However, they are also associated with a variety of dermatological conditions and even cause systemic infections. How these yeasts can live as commensals on the skin and switch to a pathogenic stage has long been a matter of debate. Lipids are important cellular molecules, and understanding the lipid metabolism and composition of species is crucial to comprehending their biology and host-microbe interaction. Here, we investigated the lipid composition of strains grown to the stationary phase in a complex Dixon medium broth. In this study, we perform a lipidomic analysis of a subset of species; in addition, we conducted a gene prediction analysis for the detection of lipid metabolic proteins. We identified 18 lipid classes and 428 lipidic compounds. The most commonly found lipids were triglycerides (TAG), sterol (CH), diglycerides (DG), fatty acids (FAs), phosphatidylcholine (PC), phosphatidylethanolamine (PE), ceramides, cholesteryl ester (CE), sphingomyelin (SM), acylcarnitine, and lysophospholipids. Particularly, we found a low content of CEs in , atypical , and and undetectable traces of these components in , and . Remarkably, uncommon lipids in yeast, like diacylglyceryltrimethylhomoserine and FA esters of hydroxyl FAs, were found in a variable concentration in these species. The latter are bioactive lipids recently reported to have antidiabetic and anti-inflammatory properties. The results obtained can be used to discriminate different species and offer a new overview of the lipid composition of these yeasts. We could confirm the presence and the absence of certain lipid-biosynthesis genes in specific species. Further analyses are necessary to continue disclosing the complex lipidome of species and the impact of the lipid metabolism in connection with the host interaction.
Topics: Animals; Humans; Lipidomics; Lipids; Malassezia; Saccharomyces cerevisiae
PubMed: 32760678
DOI: 10.3389/fcimb.2020.00338 -
BMC Veterinary Research Jul 2020Fungal infection of animals or humans are common all over the world. Some of microorganisms like fungi, exist on the skin and can be transmitted onto other individuals,...
BACKGROUND
Fungal infection of animals or humans are common all over the world. Some of microorganisms like fungi, exist on the skin and can be transmitted onto other individuals, other animal species or even humans and cause skin infections. Moreover, they can be the causative agents of severe generalized infections especially in immunocompromised individuals. The study aimed to evaluate the most frequent etiological agents of skin diseases and to compare the prevalence of animal fungal infections in Poland, and to discuss the possibility of transmission to humans in Poland.
RESULTS
The obtained results are culture based. The fungi most frequently isolated from group of animals with skin lesions were Malassezia pachydermatis (29.14%), and Candida yeasts (27.07%), and dermatophytes (23.5%), including Microsporum canis as majority of them (59.25%), and Trichophyton genus (40.7%), most of them T. mentagrophytes, while Malassezia pachydermatis represented (80%) of isolates in animals with otitis externa. In over 19% of positive fungal cultures obtained from external ear canals Candida yeasts, mainly C. albicans, were identified.
CONCLUSIONS
Dermatomycoses in companion animals are caused by both, mycelial fungi and yeasts. Most frequently isolated were Malassezia pachydermatis and Candida spp. Dermatophytes (Trichophyton, Microsporum), were also cultured, but the total number of these isolates seems to decrease. We have not found Cryptococcus neoformans in tested clinical samples.
Topics: Animals; Animals, Domestic; Dermatomycoses; Fungi; Humans; Otitis Externa; Poland; Retrospective Studies; Zoonoses
PubMed: 32680509
DOI: 10.1186/s12917-020-02460-x -
Journal of Fungi (Basel, Switzerland) Jun 2020is 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... (Review)
Review
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 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 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.
PubMed: 32630397
DOI: 10.3390/jof6020093 -
Frontiers in Cellular and Infection... 2020and are lipophilic and lipid dependent yeasts, associated with the skin microbiota in humans and domestic animals, respectively. Although they are commensals, under...
and are lipophilic and lipid dependent yeasts, associated with the skin microbiota in humans and domestic animals, respectively. Although they are commensals, under specific conditions they become pathogens, causing skin conditions, such as pityriasis versicolor, dandruff/seborrheic dermatitis, folliculitis in humans, and dermatitis and otitis in dogs. Additionally, these species are associated with fungemia in immunocompromised patients and low-weight neonates in intensive care units with intravenous catheters or with parenteral nutrition and that are under-treatment of broad-spectrum antibiotics. The host-pathogen interaction mechanism in these yeasts is still unclear; for this reason, it is necessary to implement suitable new host systems, such as . This infection model has been widely used to assess virulence, host-pathogen interaction, and antimicrobial activity in bacteria and fungi. Some advantages of the model are: (1) the immune response has phagocytic cells and antimicrobial peptides that are similar to those in the innate immune response of human beings; (2) no ethical implications; (3) low cost; and (4) easy to handle and inoculate. This study aims to establish as an infection model for and . To achieve this objective, first, larvae were first inoculated with different inoculum concentrations of these two species, 1.5 × 10 CFU/mL, 1.5 × 10 CFU/mL, 1.5 × 10 CFU/mL, and 11.5 × 10 CFU/mL, and incubated at 33 and 37°C. Then, for 15 days, the mortality and melanization were evaluated daily. Finally, the characterization of hemocytes and fungal burden assessment were as carried out. It was found that at 33 and 37°C both and successfully established a systemic infection in . proved to be slightly more virulent than at a temperature of 37°C. The results suggest that larvae mortality and melanization is dependent on the specie of , the inoculum concentration and the temperature. According to the findings, can be used as an model of infection to conduct easy and reliable approaches to boost our knowledge of the genus.
Topics: Animals; Dandruff; Dogs; Host-Pathogen Interactions; Humans; Malassezia; Skin
PubMed: 32432057
DOI: 10.3389/fcimb.2020.00199 -
Scientific Reports Mar 2020The opportunistic pathogen Malassezia pachydermatis causes bloodstream infections in preterm infants or individuals with immunodeficiency disorders and has been...
The opportunistic pathogen Malassezia pachydermatis causes bloodstream infections in preterm infants or individuals with immunodeficiency disorders and has been associated with a broad spectrum of diseases in animals such as seborrheic dermatitis, external otitis and fungemia. The current approaches to treat these infections are failing as a consequence of their adverse effects, changes in susceptibility and antifungal resistance. Thus, the identification of novel therapeutic targets against M. pachydermatis infections are highly relevant. Here, Gene Essentiality Analysis and Flux Variability Analysis was applied to a previously reported M. pachydermatis metabolic network to identify enzymes that, when absent, negatively affect biomass production. Three novel therapeutic targets (i.e., homoserine dehydrogenase (MpHSD), homocitrate synthase (MpHCS) and saccharopine dehydrogenase (MpSDH)) were identified that are absent in humans. Notably, L-lysine was shown to be an inhibitor of the enzymatic activity of MpHCS and MpSDH at concentrations of 1 mM and 75 mM, respectively, while L-threonine (1 mM) inhibited MpHSD. Interestingly, L- lysine was also shown to inhibit M. pachydermatis growth during in vitro assays with reference strains and canine isolates, while it had a negligible cytotoxic activity on HEKa cells. Together, our findings form the bases for the development of novel treatments against M. pachydermatis infections.
Topics: Animals; Cell Line; Dermatomycoses; Dose-Response Relationship, Drug; Fungal Proteins; Fungemia; Genes, Essential; Homoserine Dehydrogenase; Humans; Lysine; Malassezia; Oxo-Acid-Lyases; Saccharopine Dehydrogenases; Threonine
PubMed: 32184419
DOI: 10.1038/s41598-020-61729-1 -
Microorganisms Feb 2020spp. bacteria are the most frequently involved agents in canine cutaneous infections. Treatment of these infections is based on antibiotic therapy, that often is not...
spp. bacteria are the most frequently involved agents in canine cutaneous infections. Treatment of these infections is based on antibiotic therapy, that often is not effective because of the antibiotic-resistance of the bacterial strains. Cutaneous staphylococcal infections are often complicated by yeasts, that may be resistant to the conventional antifungal drugs. The present investigation was aimed to evaluate the in vitro antimicrobial activity of some essential oils (EOs) in view of a potential cutaneous application. In detail, EOs obtained from lemon verbena ( L'Hèr. Britton), cinnamon ( J. Presl), myrrh ( (Nees) Engl. var. ), lemongrass ( (DC.) Stapf), litsea ( (Lour.) Pers.), lemon balm ( L.), oregano ( L.), savory ( L.), and thyme ( L.) were assayed against spp. and strains previously isolated from dogs with dermatitis. All EOs were tested by agar disk diffusion and minimum inhibitory concentration methods to verify the antistaphylococcal activity, and by a microdilution method to evaluate the activity against . , and showed the best antibacterial activity against all the selected strains, with MICs ranging from 0.29 to 0.58 mg/mL, from 0.58 to 1.16 mg/mL, and from 0.56 to 1.12 mg/mL, respectively, whereas (1.03 mg/mL) and (1.8 mg/mL) were the most active against . After a proper in vivo evaluation, , , and EOs could be a promising treatment to combat canine cutaneous mixed infections.
PubMed: 32069976
DOI: 10.3390/microorganisms8020252 -
Frontiers in Veterinary Science 2019Clinical mycoses treatment is associated with issues such as negative side effects, high cost, prolonged treatment, and resistant strain selection. is the most...
Clinical mycoses treatment is associated with issues such as negative side effects, high cost, prolonged treatment, and resistant strain selection. is the most frequently isolated yeast in cases of canine otitis and dermatitis. The number of fungal strains exhibiting primary resistance to several drugs is increasing. Propolis has a diverse chemical composition and well-known therapeutic properties against mycoses. An alternative method for producing propolis extracts using supercritical fluid has higher selectivity, yielding extracts with fewer pollutant residues. This study therefore aimed to evaluate the susceptibility profile of clinical isolates to precharacterized supercritical and ethanolic extracts. Three types of Brazilian propolis extracts (green, red, and brown) and commercial allopathic antifungals were used in this investigation. We used the microdilution broth technique to evaluate the susceptibility profile of the yeasts. The minimum inhibitory concentration (MIC) of the brown propolis ethanolic extract was ≥16 μg/mL for all isolates. The MICs of fluconazole, ketoconazole, itraconazole, and amphotericin B ranged from 8 to >64 μg/mL, 0.032-4 μg/mL, 0.0313-16 μg/mL, and 1-2 μg/mL, respectively. The MICs of ethanolic red propolis extracts were lower than those of supercritical red propolis extracts. However, the green propolis ethanolic extract had more pronounced fungicidal activity. Isolates with lower susceptibility to commercial fungicides were inhibited by red and green propolis extracts. These results indicate that propolis can potentially be used in experiments as a promising therapeutic agent against infections.
PubMed: 31921917
DOI: 10.3389/fvets.2019.00460 -
Complementary Medicine Research 2020The yeast Malassezia pachydermatis is a commensal but also the most isolated pathogenic yeast in canine otitis externa. Essential oils (EOs) exhibit antimicrobial...
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.
Topics: Animals; Antifungal Agents; Dog Diseases; Dogs; Female; Malassezia; Male; Microbial Sensitivity Tests; Oils, Volatile; Otitis Externa
PubMed: 31775141
DOI: 10.1159/000504316 -
BMC Veterinary Research Oct 2019Topical antimicrobials are recommended for first line treatment of surface and superficial infections in dogs. This is especially important given the increasing...
BACKGROUND
Topical antimicrobials are recommended for first line treatment of surface and superficial infections in dogs. This is especially important given the increasing prevalence of antimicrobial resistant infections. Antimicrobial wipes have become popular, but there are a lack of controlled studies assessing their in vitro antimicrobial and in vivo residual activity. We aimed to assess the antimicrobial efficacy of two commercial antimicrobial wipes against frequently isolated pathogens. Ten clinical and one reference isolate each of meticillin-susceptible Staphylococcus pseudintermedius (MSSP), meticillin-resistant S. pseudintermedius (MRSP), Escherichia coli (EC), extended spectrum beta-lactamase (ESBL) producing E. coli (ESBL-EC), Pseudomonas aeruginosa (PA) and Malassezia pachydermatis (MP) were tested using a modified Kirby-Bauer technique. Each isolate was tested against 6 mm discs of chlorhexidine (CHX) and acetic acid/boric acid (AABA) wipes, and positive and negative controls either overnight (bacteria) or for 3 days (Malassezia). Healthy dogs were treated with the wipes and distilled water on a randomised flank (n = 5 each). Hair samples (1 cm; 0.1 g) taken at days 0, 1 and 3 were inoculated with an isolate of each organism. Zones of inhibition (ZI) were measured.
RESULTS
All isolates produced confluent growth with AABA and control wipes, except for the cleansing wipes and MP (median ZI 12 mm; 95% CI 8.2-15.8). The median (95% CI) CHX wipe ZIs (mm) were: MP 48.0 (47.0-49.0), MSSP 15.6 (14.2-17.0), MRSP 14.0 (13.6-14.4), EC 13.6 (12.0-15.2) and ESBL-EC 10.0 (9.4-10.6). PA showed confluent growth. The differences between the bacterial isolates was significant (Kruskal-Wallis p < 0.0001; post-tests MSSP = MRSP = EC > EBSL-EC > PA). Confluent growth was visible with all the hair samples.
CONCLUSION
CHX but not AABA showed in vitro efficacy against MSSP, MRSP, EC and MP. ESBL-EC were less susceptible and there was no activity against PA. There was no residual activity on hair. Additional studies are required to determine efficacy of these products in clinically affected patients.
Topics: Acetic Acid; Administration, Topical; Animals; Anti-Infective Agents, Local; Bacteria; Boric Acids; Chlorhexidine; Dogs; Pilot Projects; Skin
PubMed: 31666075
DOI: 10.1186/s12917-019-2098-z