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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 -
Parassitologia Jun 2008The genus Malassezia includes twelve species of yeast, many of which have been mainly associated with human and canine diseases. Malassezia pachydermatis colonizes the... (Review)
Review
The genus Malassezia includes twelve species of yeast, many of which have been mainly associated with human and canine diseases. Malassezia pachydermatis colonizes the skin and mucosal sites of healthy dogs and cats. Despite being part of the normal cutaneous microflora, Malassezia spp. yeast may become pathogenic under certain circumstances. This article reviews the factors related to both host and yeast which affect the pathogenical or commensal phenotypes of Malassezia yeasts.
Topics: Animals; Antigens, Fungal; Cat Diseases; Cats; Comorbidity; Dermatomycoses; Dog Diseases; Dogs; Humans; Immunocompromised Host; Leishmania infantum; Leishmaniasis, Visceral; Malassezia; Skin; Virulence
PubMed: 18693560
DOI: No ID Found -
Journal of Veterinary Diagnostic... May 2019Malassezia pachydermatis is part of the normal microbiota of canine skin and external ear canal, and is also associated with otitis externa in dogs. Laboratory detection...
Malassezia pachydermatis is part of the normal microbiota of canine skin and external ear canal, and is also associated with otitis externa in dogs. Laboratory detection of Malassezia otitis relies on the presence of elevated numbers of the yeast on cytologic examination of otic exudate. Although cytology has high specificity, it has low sensitivity, resulting in false-negatives and posing a challenge for clinicians to accurately diagnose Malassezia otitis. We developed a quantitative PCR (qPCR) to detect and quantify M. pachydermatis yeasts and validate the method with swabs from external ear canals of dogs. Our qPCR uses the β-tubulin gene, a single-copy gene, as a target. The limit of quantification was established as 0.18 ng/reaction, equivalent to 2.0 × 10 genome equivalents (gEq). Swabs from healthy dogs yielded quantification values of ≤2.7 × 10 gEq in the qPCR, whereas swabs from dogs with otitis yielded quantification values of ≥2.5 × 10 gEq. Our qPCR assay provides accurate quantification of M. pachydermatis yeasts from swab samples from dogs, is more sensitive than cytology, and could be used to monitor response to treatment. Our assay could also be valuable in a research setting to better understand the pathogenesis of M. pachydermatis.
Topics: Animals; Dermatomycoses; Dog Diseases; Dogs; Ear Canal; Malassezia; Otitis Externa; Real-Time Polymerase Chain Reaction
PubMed: 30943876
DOI: 10.1177/1040638719840686 -
Mycoses Dec 2017Previous studies have evaluated the action of gentamicin against Malassezia pachydermatis. The aim of this study was to evaluate in vitro susceptibility of...
Previous studies have evaluated the action of gentamicin against Malassezia pachydermatis. The aim of this study was to evaluate in vitro susceptibility of M. pachydermatis to the aminoglycosides- gentamicin, tobramycin, netilmicin and framycetin. The minimum inhibitory concentration (MIC) of gentamicin was determined following methods M27-A3 microdilution and Etest . The Etest was used to determine the minimum inhibitory concentration (MIC) of the tobramycin and netilmicin. The Kirby-Bauer test was used to determine the antibiotic susceptibility to the framycetin. The MIC50 and MIC90 were 8.12 μg/mL and 32.5 μg/mL by microdilution method for gentamicin. The MIC50, determined by the Etest , was 8 μg/mL for gentamicin and netilmicin and 64 μg/mL for tobramycin. The MIC90 was 16 and 32 μg/mL for gentamicin and netilmicin respectively. The MIC90 was outside of the detectable limits for tobramycin. To framycetin, 28 strains (40%) of the 70 M. pachydermatis isolates tested showed a diameter of 22 mm, 22 strains (31.42%) showed a diameter of 20 mm, 16 strains showed a diameter of ≤ 18 mm, and only 5.71% of the isolates showed a diameter of ≥ 22 mm. This study provides evidence of high in vitro activity of the aminoglycosides-gentamicin, tobramycin, netilmicin and framycetin against M. pachydermatis. For gentamicin Etest showed similar values of MIC50 y MIC90 that the obtained by microdilution method. We considered Etest method could be a good method for these calculations with aminoglycosides.
Topics: Amikacin; Aminoglycosides; Antifungal Agents; Gentamicins; Malassezia; Microbial Sensitivity Tests; Netilmicin; Tobramycin
PubMed: 28925032
DOI: 10.1111/myc.12665 -
Veterinary Medicine and Science Nov 2023Fungal and yeast infections, including those caused by Malassezia spp., are becoming increasingly difficult to treat, likely due to the occurrence of drug resistance.
BACKGROUND
Fungal and yeast infections, including those caused by Malassezia spp., are becoming increasingly difficult to treat, likely due to the occurrence of drug resistance.
OBJECTIVES
This study aimed to evaluate the antifungal effects of omeprazole (OME), a proton pump inhibitor, against antifungal-resistant Malassezia pachydermatis and to investigate the potential synergistic effects between OME and other antifungal compounds.
METHODS
In total, 15 samples of M. pachydermatis isolated from the skin of dogs were tested. The susceptibility of M. pachydermatis to itraconazole, ketoconazole, miconazole, terbinafine and OME was assessed using a modified broth microdilution (BM) method. The in vitro efficacy of OME alone and in combination with other antifungal compounds was evaluated for all isolates using the BM chequerboard method. The data obtained were analysed using the fractional inhibitory concentration index (FICI).
RESULTS
The minimum inhibitory concentration (MIC) values of antifungal compounds and OME against quality control strain (M. pachydermatis CBS1879) were lower than the MIC values of same drugs against clinically collected strains. There was no significant difference in MIC values between drugs alone and combination. According to the analysis by the FICI method, no interaction was observed with OME and antifungal compounds.
CONCLUSIONS
Most M. pachydermatis strains were resistant to azole antifungal compounds. OME exerted antifungal effects against Malassezia spp. and even showed good effects on antifungal-resistant strains. No synergistic effects were observed between the antifungal compounds and OME.
Topics: Animals; Dogs; Antifungal Agents; Malassezia; Omeprazole; Drug Resistance, Fungal
PubMed: 37872836
DOI: 10.1002/vms3.1305 -
Clinical Microbiology and Infection :... Apr 2014The mortality associated with invasive fungal infections remains high with that involving rare yeast pathogens other than Candida being no exception. This is in part due...
The mortality associated with invasive fungal infections remains high with that involving rare yeast pathogens other than Candida being no exception. This is in part due to the severe underlying conditions typically predisposing patients to these healthcare-related infections (most often severe neutropenia in patients with haematological malignancies), and in part due to the often challenging intrinsic susceptibility pattern of the pathogens that potentially leads to delayed appropriate antifungal treatment. A panel of experts of the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Fungal Infection Study Group (EFISG) and the European Confederation of Medical Mycology (ECMM) undertook a data review and compiled guidelines for the diagnostic tests and procedures for detection and management of rare invasive yeast infections. The rare yeast pathogens were defined and limited to the following genera/species: Cryptococcus adeliensis, Cryptococcus albidus, Cryptococcus curvatus, Cryptococcus flavescens, Cryptococcus laurentii and Cryptococcus uniguttulatus (often published under the name Filobasidium uniguttulatum), Malassezia furfur, Malassezia globosa, Malassezia pachydermatis and Malassezia restricta, Pseudozyma spp., Rhodotorula glutinis, Rhodotorula minuta and Rhodotorula mucilaginosa, Sporobolomyces spp., Trichosporon asahii, Trichosporon asteroides, Trichosporon dermatis, Trichosporon inkin, Trichosporon jirovecii, Trichosporon loubieri, Trichosporon mucoides and Trichosporon mycotoxinivorans and ascomycetous ones: Geotrichum candidum, Kodamaea ohmeri, Saccharomyces cerevisiae (incl. S. boulardii) and Saprochaete capitatae (Magnusiomyces (Blastoschizomyces) capitatus formerly named Trichosporon capitatum or Geotrichum (Dipodascus) capitatum) and Saprochaete clavata. Recommendations about the microbiological investigation and detection of invasive infection were made and current knowledge on the most appropriate antifungal and supportive treatment was reviewed. In addition, remarks about antifungal susceptibility testing were made.
Topics: Humans; Mycoses; Rare Diseases
PubMed: 24102785
DOI: 10.1111/1469-0691.12360 -
Journal of Feline Medicine and Surgery Dec 2010Carriage of Malassezia species yeasts in healthy Sphynx cats was compared with that in Devon Rex cats (DRC), Cornish Rex cats (CRC) and domestic shorthair (DSH) cats.... (Comparative Study)
Comparative Study
Carriage of Malassezia species yeasts in healthy Sphynx cats was compared with that in Devon Rex cats (DRC), Cornish Rex cats (CRC) and domestic shorthair (DSH) cats. Swab samples from the external ear, anus and claw folds, and contact plate samples from the axillae and groins, were incubated on modified Dixon's agar at 32°C for 7 days. Malassezia species were isolated from all 18 Sphynx cats; M pachydermatis accounted for 118/140 isolates. Of 20 isolates of M nana, 16 were recovered from the ear canal. M slooffiae was isolated from the claw fold of one cat and the left groin of another. The high counts of M pachydermatis obtained from the axillae, groins and claw folds of the Sphynx cats exceeded those of healthy DSH, CRC and DRC; axillary populations were comparable to those of seborrhoeic DRC. These data support recent reports of high Malassezia species colonisation in Sphynx cats.
Topics: Animals; Carrier State; Cat Diseases; Cats; Dermatitis, Seborrheic; Dermatomycoses; Female; Malassezia; Male; Skin; Species Specificity
PubMed: 20863732
DOI: 10.1016/j.jfms.2010.07.002 -
Medical Mycology Nov 2013Antifungal resistance has been associated with biofilm formation in many microorganisms, but not yet in Malassezia pachydermatis. This saprophytic yeast can cause otitis...
Antifungal resistance has been associated with biofilm formation in many microorganisms, but not yet in Malassezia pachydermatis. This saprophytic yeast can cause otitis and dermatitis in dogs and has emerged as an important human pathogen, responsible for systemic infections in neonates in intensive care units. This study aims to evaluate the in vitro antifungal susceptibility of M. pachydermatis strains, in both their planktonic and sessile forms, to fluconazole, miconazole, ketoconazole, itraconazole, posaconazole, terbinafine and voriconazole using the XTT assay and Clinical and Laboratory Standards Institute (CLSI) microdilution method. The minimum inhibitory concentration (MIC) values recorded for each drug were significantly higher for sessile cells relative to planktonic cells to the extent that ≥ 90% of M. pachydermatis strains in their sessile form were classified as resistant to all antifungal agents tested. Data suggest that M. pachydermatis biofilm formation is associated with antifungal resistance, paving the way towards investigating drug resistance mechanisms in Malassezia spp.
Topics: Animals; Antifungal Agents; Biofilms; Dermatomycoses; Dogs; Drug Resistance, Fungal; Humans; Malassezia; Microbial Sensitivity Tests
PubMed: 23834283
DOI: 10.3109/13693786.2013.805440 -
Veterinary Journal (London, England :... Nov 2006To investigate the role of Malassezia pachydermatis as a pathogenic agent in canine otitis, a comparative analysis of isolates from normal and diseased external ear...
To investigate the role of Malassezia pachydermatis as a pathogenic agent in canine otitis, a comparative analysis of isolates from normal and diseased external ear canals in dogs was undertaken. Specimens were collected from the ears of dogs with unilateral or bilateral otitis and from healthy dogs. Mycological analysis was by direct microscopy and fungal culture on Sabouraud's dextrose agar and Dixon's agar. Of the otitis specimens, 63.7% showed typical Malassezia cells on cytological examination. In samples taken from the healthy ears of dogs with unilateral otitis, only 21.43% (P<0.05) showed evidence of Malassezia. M. pachydermatis was identified cytologically and culturally in 57.53% (P<0.05), 14.29% and 30.0% of samples from the ears of dogs with otitis, from the healthy ears of dogs with unilateral otitis and from the ears of healthy dogs with no otitis. In the group with otitis associated with M. pachydermatis, the poodle was the most common breed (39.29%; P<0.05), whereas in the group without otitis, the German Shepherd breed was prominent (although this observation was not statistically significant). In both groups, the majority of dogs with M. pachydermatis were aged between 1 and 3 years (P<0.05). The higher incidence of M. pachydermatis isolated from the ears of dogs with otitis externa suggests a putative pathogenic role of this yeast in this condition.
Topics: Animals; Dermatomycoses; Dog Diseases; Dogs; Female; Malassezia; Male; Otitis Externa
PubMed: 16154787
DOI: 10.1016/j.tvjl.2005.07.004 -
Current Protocols May 2021Malassezia spp. are lipid-dependent yeasts that have been related to skin mycobiota and dermatological and systemic diseases. Study of lipid droplets (LDs) is relevant...
Malassezia spp. are lipid-dependent yeasts that have been related to skin mycobiota and dermatological and systemic diseases. Study of lipid droplets (LDs) is relevant to elucidate the unknown role of these organelles in Malassezia and to gain a broader overview of lipid metabolism in Malassezia. Here, we standardized two protocols for the analysis of LDs in M. pachydermatis and M. globosa. The first describes co-staining for confocal laser-scanning fluorescence microscopy, and the second details extraction and purification of LDs. The double stain is achieved with three different neutral lipid fluorophores, namely Nile Red, BODIPY™ 493/503, and HCS LipidTOX™ Deep Red Neutral, in combination with Calcofluor White. For LD extraction, cell wall rupture is conducted using Trichoderma harzianum enzymes and cycles of vortexing with zirconium beads. LD purification is performed in a three-step ultracentrifugation process. These standardizations will contribute to the study of the dynamics, morphology, and composition of LDs in Malassezia. © 2021 Wiley Periodicals LLC. Basic Protocol 1: Lipid droplet fluorescence staining Basic Protocol 2: Lipid droplet extraction and purification Support Protocol: Malassezia spp. culture conditions.
Topics: Hypocreales; Lipid Droplets; Malassezia
PubMed: 33950584
DOI: 10.1002/cpz1.122