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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 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 -
Mycopathologia Apr 2023Malassezia pachydermatis is part of the normal skin microbiota of various animal species but under certain circumstances becomes an opportunistic pathogen producing...
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.
Topics: Animals; Antifungal Agents; Azoles; Malassezia; Ketoconazole; Itraconazole; Microbial Sensitivity Tests; Drug Resistance, Fungal
PubMed: 36495417
DOI: 10.1007/s11046-022-00696-9 -
Journal of Fungi (Basel, Switzerland) Oct 2018This review focuses on aspects of antimycotic therapy specific to veterinary medicine. In the first part, drug availability, limited mostly by economic consideration but... (Review)
Review
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 ( spp. and ).
PubMed: 30380772
DOI: 10.3390/jof4040120 -
Journal of Fungi (Basel, Switzerland) Nov 2022The yeast , an opportunistic pathogen that inhabits the skin of various domestic and wild animals, is capable of producing a biofilm that plays an important role in...
The yeast , an opportunistic pathogen that inhabits the skin of various domestic and wild animals, is capable of producing a biofilm that plays an important role in antifungal resistance. The aim of this research study was to find the intensity of biofilm production by strains isolated from the ear canal of healthy dogs, and to determine the susceptibility of planktonic, adhered and biofilm-forming cells to three azole antifungals-itraco-nazole, voriconazole and posaconazole-that are most commonly used to treat infections. Out of 52 isolates, 43 strains (82.7%) were biofilm producers with varying levels of intensity. For planktonic cells, the minimum inhibitory concentration (MIC) range was 0.125-2 µg/mL for itraconazole, 0.03-1 µg/mL for voriconazole and 0.03-0.25 µg/mL for posaconazole. Only two isolates (4.7%) were resistant to itraconazole, one strain (2.3%) to voriconazole and none to posaconazole. For adhered cells and the mature biofilm, the following MIC ranges were found: 0.25-16 µg/mL and 4-16 µg/mL for itraconazole, 0.125-8 µg/mL and 0.25-26 µg/mL for voriconazole, and 0.03-4 µg/mL and 0.25-16 µg/mL for posaconazole, respectively. The least resistance for adhered cells was observed for posaconazole (55.8%), followed by voriconazole (62.8%) and itraconazole (88.4%). The mature biofilm of showed 100% resistance to itraconazole, 95.3% to posaconazole and 83.7% to voriconazole. The results of this study show that higher concentrations of commonly used antifungal agents are needed to control infections caused by biofilm-forming strains of .
PubMed: 36422031
DOI: 10.3390/jof8111209 -
The Journal of Veterinary Medical... Mar 2023Canine Malassezia dermatitis and otitis externa are generally treated by antifungal drugs. However, multi-drug-resistant strains of Malassezia pachydermatis have been...
Canine Malassezia dermatitis and otitis externa are generally treated by antifungal drugs. However, multi-drug-resistant strains of Malassezia pachydermatis have been reported worldwide. Given the presence of these multi-drug-resistant strains, it is unclear which antifungal agent is the most effective for canine Malassezia dermatitis and canine otitis. In this study, we attempted to determine the most effective drug against azole-resistant M. pachydermatis. Susceptibility to azoles and terbinafine (TBF) was assessed using a modified broth microdilution method. In all tested isolates, the minimum inhibitory concentration at 90% of organisms (MIC) were 16 to >32 μg/mL for the azoles, and 2 μg/mL for TBF. All of the strains that showed low susceptibility to both itraconazole and miconazole were also relatively susceptible to TBF.
Topics: Animals; Dogs; Azoles; Terbinafine; Malassezia; Japan; Antifungal Agents; Microbial Sensitivity Tests; Dermatitis; Dog Diseases
PubMed: 36724970
DOI: 10.1292/jvms.22-0358 -
Journal of Microbiological Methods Mar 2017Malassezia spp. are part of the normal human and animal mycobiota but are also associated with a variety of dermatological diseases. The absence of a transformation...
Malassezia spp. are part of the normal human and animal mycobiota but are also associated with a variety of dermatological diseases. The absence of a transformation system hampered studies to reveal mechanisms underlying the switch from the non-pathogenic to pathogenic life style. Here we describe, a highly efficient Agrobacterium-mediated genetic transformation system for Malassezia furfur and M. pachydermatis. A binary T-DNA vector with the hygromycin B phosphotransferase (hpt) selection marker and the green fluorescent protein gene (gfp) was introduced in M. furfur and M. pachydermatis by combining the transformation protocols of Agaricus bisporus and Cryptococcus neoformans. Optimal temperature and co-cultivation time for transformation were 5 and 7days at 19°C and 24°C, respectively. Transformation efficiency was 0.75-1.5% for M. furfur and 0.6-7.5% for M. pachydermatis. Integration of the hpt resistance cassette and gfp was verified using PCR and fluorescence microscopy, respectively. The T-DNA was mitotically stable in approximately 80% of the transformants after 10 times sub-culturing in the absence of hygromycin. Improving transformation protocols contribute to study the biology and pathophysiology of Malassezia.
Topics: Agaricus; Agrobacterium tumefaciens; Coculture Techniques; Cryptococcus neoformans; DNA, Bacterial; Dermatomycoses; Genetic Vectors; Green Fluorescent Proteins; Humans; Malassezia; Microscopy, Fluorescence; Phosphotransferases (Alcohol Group Acceptor); Polymerase Chain Reaction; Transformation, Genetic
PubMed: 28064034
DOI: 10.1016/j.mimet.2017.01.001 -
Journal of Fungi (Basel, Switzerland) Jul 2017Reference methods for antifungal susceptibility testing of yeasts have been developed by the Clinical and Laboratory Standards Institute (CLSI) and the European... (Review)
Review
Reference methods for antifungal susceptibility testing of yeasts have been developed by the Clinical and Laboratory Standards Institute (CLSI) and the European Committee on Antibiotic Susceptibility Testing (EUCAST). These methods are intended to test the main pathogenic yeasts that cause invasive infections, namely spp. and , while testing other yeast species introduces several additional problems in standardization not addressed by these reference procedures. As a consequence, a number of procedures have been employed in the literature to test the antifungal susceptibility of . This has resulted in conflicting results. The aim of the present study is to review the procedures and the technical parameters (growth media, inoculum preparation, temperature and length of incubation, method of reading) employed for susceptibility testing of , and when possible, to propose recommendations for or against their use. Such information may be useful for the future development of a reference assay.
PubMed: 29371554
DOI: 10.3390/jof3030037 -
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 -
ACS Infectious Diseases Sep 2022Fungal promoted infections are becoming a severe health global emergency due to drug-resistant phenomena and zoonosis. This work investigated compounds bearing...
Fungal promoted infections are becoming a severe health global emergency due to drug-resistant phenomena and zoonosis. This work investigated compounds bearing acyl-/selenoureido moieties and primary/secondary sulfonamide groups as novel antifungal agents acting through organism-directed selenium toxicity and inhibition of the newly emergent therapeutic target, the Carbonic Anhydrases (CAs; EC 4.2.1.1). Reported data clearly indicate that seleno-containing scaffolds with respect to the standard-of-care drugs showed appreciable antifungal activity, which was suppressed when the chalcogen was replaced with its cognate isosteric elements sulfur and oxygen. In addition, such compounds showed excellent selectivity against over its related genus strains and . Safe cytotoxicity profiles on bovine kidney cells (MDBK) and human HaCat cells, as well as the shallow hemolytic activity on defibrinated sheep blood, allowed us to consider these compounds as up-and-coming novel antifungals.
Topics: Animals; Antifungal Agents; Carbonic Anhydrases; Cattle; Humans; Mycoses; Sheep; Sulfonamides
PubMed: 35984421
DOI: 10.1021/acsinfecdis.2c00250