Sporotrichosis in Argentina: clinical and epidemiological analysis / Esporotricosis en Argentina: análisis clínico y epidemiológico

Introduction: Sporotrichosis is an implantation mycosis caused by Sporothrix spp. It is distributed worldwide and can be found in vegetation and soil. The most frequent route of infection is by trauma with elements contaminated with fungal propagules. Since domestic cats are the most affected animals and can transmit this infection to humans, sporotrichosis is considered a zoonosis. Clinical presentations include nodular lymphangitis, fixed cutaneous, pulmonary (rare), and disseminated (exceptional). Objectives: To analyze the epidemiology of sporotrichosis in Argentina during 2010 and 2022. To describe the clinical presentation, diagnostic methods, and treatment of cases diagnosed during this period. To know the circulating genotypes and to observe possible associations with the geographic location where the infection was acquired. Materials and methods: Analytical, retrospective, and observational study. We analyzed the medical records of patients with sporotrichosis from 12 health institutions in Argentina, between 2010 and 2022. Results: We present 54 cases in which the most frequent clinical form was nodular lymphangitis, and the treatment of choice was itraconazole. Conventional diagnosis was made in all cases. Culture of clinical samples was more sensitive than direct examination because it allowed the isolation of Sporothrix spp. in all 54 cases. Molecular identification was performed in 22 cases, with Sporothrix schenkii sensu stricto being the most frequently isolated species. Conclusions: This study allowed to know the epidemiology of this mycosis in Argentina, as well as the availability of diagnostic methods and the treatment of choice.

Introducción: La esporotricosis es una micosis de implantación causada por Sporothrix spp. Este se encuentra distribuido mundialmente y se puede encontrar en la vegetación y en el suelo. La ruta más frecuente de adquisición de la infección es por traumatismos con elementos contaminados con propágulos del hongo. Los gatos domésticos son los animales más afectados y pueden transmitirla a los humanos, por lo que es considerada una zoonosis. Las formas clínicas incluyen: la linfangítica nodular, la cutánea fija, la pulmonar (poco habitual) y la diseminada (excepcional). Objetivo: Analizar la epidemiología de la esporotricosis en Argentina entre los años 2010 y 2022. Describir la presentación clínica, los métodos de diagnóstico y el tratamiento de los casos diagnosticados en este período. Conocer los genotipos circulantes y observar su relación con el lugar geográfico de adquisición de la infección. Materiales y métodos. Se llevó a cabo un estudio analítico, retrospectivo y observacional, en el que se analizaron las historias clínicas de los pacientes con esporotricosis de 12 instituciones de salud de Argentina, entre los años 2010 y 2022. Resultados: Se presentan 54 casos en los que la forma clínica más frecuente fue la linfangítica nodular y el tratamiento de elección fue el itraconazol. En todos los casos se realizó diagnóstico convencional. El cultivo de las muestras clínicas resultó más sensible que el examen directo, ya que permitió el desarrollo de Sporothrix spp. en los 54 casos. En 22 casos se hizo identificación molecular y Sporothrix schenkii sensu stricto fue la especie más frecuentemente aislada. Conclusiones: Este estudio permitió conocer la epidemiología de esta micosis en Argentina, así como la disponibilidad de métodos diagnósticos y el tratamiento de elección.

Esporotricosis en Argentina: análisis clínico y epidemiológico / Sporotrichosis in Argentina: clinical and epidemiological analysis

Introducción. La esporotricosis es una micosis de implantación causada por Sporothrix spp. Este se encuentra distribuido mundialmente y se puede encontrar en la vegetación y en el suelo. La ruta más frecuente de adquisición de la infección es por traumatismos con elementos contaminados con propágulos del hongo. Los gatos domésticos son los animales más afectados y pueden transmitirla a los humanos, por lo que es considerada una zoonosis. Las formas clínicas incluyen: la linfangítica nodular, la cutánea fija, la pulmonar (poco habitual) y la diseminada (excepcional). Objetivo. Analizar la epidemiología de la esporotricosis en Argentina entre los años 2010 y 2022. Describir la presentación clínica, los métodos de diagnóstico y el tratamiento de los casos diagnosticados en este período. Conocer los genotipos circulantes y observar su relación con el lugar geográfico de adquisición de la infección. Materiales y métodos. Se llevó a cabo un estudio analítico, retrospectivo y observacional, en el que se analizaron las historias clínicas de los pacientes con esporotricosis de 12 instituciones de salud de Argentina, entre los años 2010 y 2022. Resultados. Se presentan 54 casos en los que la forma clínica más frecuente fue la linfangítica nodular y el tratamiento de elección fue el itraconazol. En todos los casos se realizó diagnóstico convencional. El cultivo de las muestras clínicas resultó más sensible que el examen directo, ya que permitió el desarrollo de Sporothrix spp. en los 54 casos. En 22 casos se hizo identificación molecular y Sporothrix schenkii sensu stricto fue la especie más frecuentemente aislada. Conclusiones. Este estudio permitió conocer la epidemiología de esta micosis en Argentina, así como la disponibilidad de métodos diagnósticos y el tratamiento de elección.

Introduction. Sporotrichosis is an implantation mycosis caused by Sporothrix spp. It is distributed worldwide and can be found in vegetation and soil. The most frequent route of infection is by trauma with elements contaminated with fungal propagules. Since domestic cats are the most affected animals and can transmit this infection to humans, sporotrichosis is considered a zoonosis. Clinical presentations include nodular lymphangitis, fixed cutaneous, pulmonary (rare), and disseminated (exceptional). Objective. To analyze the epidemiology of sporotrichosis in Argentina during 2010 and 2022. To describe the clinical presentation, diagnostic methods, and treatment of cases diagnosed during this period. To know the circulating genotypes and to observe possible associations with the geographic location where the infection was acquired. Materials and methods. Analytical, retrospective, and observational study. We analyzed the medical records of patients with sporotrichosis from 12 health institutions in Argentina, between 2010 and 2022. Results. We present 54 cases in which the most frequent clinical form was nodular lymphangitis, and the treatment of choice was itraconazole. Conventional diagnosis was made in all cases. Culture of clinical samples was more sensitive than direct examination because it allowed the isolation of Sporothrix spp. in all 54 cases. Molecular identification was performed in 22 cases, with Sporothrix schenkii sensu stricto being the most frequently isolated species. Conclusions. This study allowed to know the epidemiology of this mycosis in Argentina, as well as the availability of diagnostic methods and the treatment of choice.

Clinical and Demographic Features of Paracoccidioidomycosis in Argentina: A Multicenter Study Analysis of 466 Cases.

Information on paracoccidioidomycosis (PCM) in Argentina is fragmented and has historically been based on estimates, supported only by a series of a few reported cases. Considering the lack of global information, a national multicentric study in order to carry out a more comprehensive analysis was warranted. We present a data analysis including demographic and clinical aspects of a historical series of 466 cases recorded over 10 years (2012-2021). Patients were aged from 1 to 89 years. The general male: female (M:F) ratio was 9.5:1 with significant variation according to the age group. Interestingly, the age range 21-30 shows an M:F ratio of 2:1. Most of the cases (86%) were registered in northeast Argentina (NEA), showing hyperendemic areas in Chaco province with more than 2 cases per 10,000 inhabitants. The chronic clinical form occurred in 85.6% of cases and the acute/subacute form occurred in 14.4% of cases, but most of these juvenile type cases occurred in northwestern Argentina (NWA). In NEA, the incidence of the chronic form was 90.6%; in NWA, the acute/subacute form exceeded 37%. Diagnosis by microscopy showed 96% positivity but antibody detection displays 17% of false negatives. Tuberculosis was the most frequent comorbidity, but a diverse spectrum of bacterial, fungal, viral, parasitic, and other non-infectious comorbidities was recorded. This national multicenter registry was launched in order to better understand the current status of PCM in Argentina and shows the two endemic zones with a highly diverse epidemiology.

Malassezia species: the need to establish epidemiological cutoff values.

Malassezia are common yeasts in human skin microbiome. Under certain conditions these yeasts may cause disease from skin disorders to systemic infections. In the absence of clinical breakpoints, epidemiological cutoff values (ECVs) are useful to differentiate isolates with acquired or mutational resistance. The aim of this work was to propose tentative ECVs of Malassezia furfur, M. sympodialis, M. globosa for fluconazole (FCZ), itraconazole (ITZ), voriconazole (VCZ), ketoconazole (KTZ) and amphotericin B (AMB). A total of 160 isolates (80 M. furfur, 50 M. sympodialis, and 30 M. globosa) were tested. Minimal inhibitory concentrations (MICs) were determined by modified broth microdilution method (CLSI). ECVs were estimated by ECOFFinder software and twofold dilutions beyond the mode. ITZ, KTZ, and VCZ showed the lowest MICs. The highest MIC and widest ranges were for FCZ and AMB. For ITZ, KTZ, and VCZ both ECVs were similar. For FCZ, AMB especially M. furfur, modal ECVs were lower than values obtained by statistical method. When MIC distribution is the only data available, ECV could provide information to help guide therapy decisions. In that drug/species combination in which different peaks in the MIC distribution were observed, difference between both ECV was greater. This is the first study that provides ECV data of 160 Malassezia yeasts. Although ECVs cannot be used as predictors of clinical response, identification of non wild-type isolates suggests that it may be less likely to respond to a given antifungal agent. LAY SUMMARY: Malassezia species causes skin disorders to systemic infections. Epidemiological cutoff value (ECV) allows for differentiation of wild-type and non wild-type isolates. Based on MIC data of 160 isolates we propose tentative ECVs for three Malassezia species. ECVs are useful in surveillance and guide therapy decisions.

Hepatic failure and malnutrition as predisposing factors of cutaneous mucormycosis in a pediatric patient.

The genus Lichtheimia is the third-most frequent genus isolated in mucormycosis. We report a cutaneous case caused by Lichtheimia ramosa, localized on the face of a pediatric patient, in the context of acute liver failure and caloric malnutrition. Several surgeries and treatment with liposomal amphotericin B enabled the patient's favorable evolution.

Genomic diversity of the human pathogen Paracoccidioides across the South American continent.

Paracoccidioidomycosis (PCM) is a life-threatening systemic mycosis widely reported in the Gran Chaco ecosystem. The disease is caused by different species from the genus Paracoccidioides, which are all endemic to South and Central America. Here, we sequenced and analyzed 31 isolates of Paracoccidioides across South America, with particular focus on isolates from Argentina and Paraguay. The de novo sequenced isolates were compared with publicly available genomes. Phylogenetics and population genomics revealed that PCM in Argentina and Paraguay is caused by three distinct Paracoccidioides genotypes, P. brasiliensis (S1a and S1b) and P. restrepiensis (PS3). P. brasiliensis S1a isolates from Argentina are frequently associated with chronic forms of the disease. Our results suggest the existence of extensive molecular polymorphism among Paracoccidioides species, and provide a framework to begin to dissect the connection between genotypic differences in the pathogen and the clinical outcomes of the disease.

Biofilm formation, adherence, and hydrophobicity of M. sympodialis, M. globosa, and M. slooffiae from clinical isolates and normal skinVirulence factors of M. sympodialis, M. globosa and M. slooffiae.

The genus Malassezia comprises a heterogeneous group of species that cause similar pathologies. Malassezia yeasts were considered as the most abundant skin eukaryotes of the total skin mycobiome. The ability of this fungus to colonize or infect is determined by complex interactions between the fungal cell and its virulence factors. This study aims to evaluate in vitro the hydrophobicity levels, the adherence capacity on a polystyrene surface and the ability to form biofilm of 19 isolates, including M. sympodialis, M. globosa, and M. slooffiae, from healthy subjects and from dermatological disorders. Cellular surface hydrophobicity levels were determined by two-phase system. The biofilm formation was determined by tetrazolium salt (XTT) reduction assay and by Scanning Electron Microscopy (SEM). Strain dependence was observed in all virulence factors studied. All isolates of M. sympodialis, M. globosa, and M. slooffiae demonstrated their ability to form biofilm at variable capacities. SEM observations confirmed a variable extracellular matrix after 48 hours of biofilm formation. All isolates of M. globosa were highly adherent and/or hydrophobic as well as biofilm producers. In contrast, M. slooffiae was the least biofilm producer. No significant differences between virulence factors were demonstrated for M. sympodialis, either as clinical isolate or as inhabitant of human microbiota. Results of this work together with the previous M. furfur research confirm that the most frequently Malassezia species isolated from normal subject's skin and patients with dermatosis, form biofilm with different capacities. The study of these virulence factors is important to highlight differences between Malassezia species and to determine their involvement in pathological processes.

Antifungal activity of silver nanoparticles in combination with ketoconazole against Malassezia furfur.

Malassezia furfur is lipophilic and lipid-dependent yeast, inhabitant of human skin microbiota associated with several dermal disorders. In recent years, along with the advances in nanotechnology and the incentive to find new antimicrobial drugs, there has been a growing interest in the utilization of nanoparticles for the treatment of skin microbial infections. This work aimed to study the in vitro inhibitory activity of silver nanoparticles (AgNP) against 41 M. furfur clinical isolates, visualize the interaction between AgNP-Malassezia, evaluate the synergism with ketoconazole (KTZ) and to produce an antimicrobial gel of AgNP-KTZ. The synthesized AgNP were randomly distributed around the yeast surface and showed a fungicidal action with low minimal inhibitory concentration values. AgNP showed no antagonistic effect with KTZ. The broad-spectrum antimicrobial property with fungicidal action of AgNP and its accumulation in affected areas with a sustained release profile, added to the great antifungal activity of KTZ against Malassezia infections and other superficial mycoses, allowed us to obtain a gel based on carbopol formulated with AgNP-KTZ with the potential to improve the topical therapy of superficial malasseziosis, reduce the number of applications and, also, prevent the recurrence.

Cavitary Pulmonary Sporotrichosis: Case Report and Literature Review.

A case of cavitary pulmonary sporotrichosis without mucocutaneous involvement caused by Sporothrix schenckii is reported in a sexagenarian woman with a long smoking history. The patient was hospitalized for septic shock with multiorgan failure from a respiratory focus. The diagnosis was delayed due to the fungal etiological agent was not initially considered in the differential diagnosis. A good clinical and radiological evolution was obtained with the antifungal therapy. Occasional cases of primary pulmonary sporotrichosis have been reported in the literature. Due to its low incidence, this is a less-known and underestimated clinical form. Both clinical suspicion and microbiological studies are needed to reach pulmonary sporotrichosis diagnosis.

In vitro activities of amphotericin B, terbinafine, and azole drugs against clinical and environmental isolates of Aspergillus terreus sensu stricto.

The antifungal susceptibilities of 40 clinical and environmental isolates of A. terreus sensu stricto to amphotericin B, terbinafine, itraconazole, and voriconazole were determined in accordance with CLSI document M38-A2. All isolates had itraconazole and voriconazole MICs lower than epidemiologic cutoff values, and 5% of the isolates had amphotericin B MICs higher than epidemiologic cutoff values. Terbinafine showed the lowest MICs. No significant differences were found when MICs of clinical and environmental isolates were compared.

Fungemia and interstitial lung compromise caused by Malassezia sympodialis in a pediatric patient.

A case of fungemia with interstitial lung compromise caused by Malassezia sympodialis is reported in an obese pediatric patient on long-term treatment with inhaled corticosteroids for asthma. The patient was hospitalized due to a post-surgical complication of appendicitis. The patient was treated with amphotericin B for 3 weeks, with good clinical evolution and subsequent negative cultures.

[Aspergillus species in hospital environments with pediatric patients in critical condition]. / Especies de Aspergillus en ambientes hospitalarios con pacientes pediátricos en estado crítico.

BACKGROUND: Aspergillus is a group of opportunistic fungi that cause infections, with high morbimortality in immunosuppressed patients. Aspergillus fumigatus is the most frequent species in these infections, although the incidence of other species has increased in the last few years. AIMS: To evaluate the air fungal load and the diversity of Aspergillus species in hospitals with pediatric patients in critical condition. METHODS: The Intensive Care Unit and Burns Unit of a pediatric hospital were sampled every 15 days during the autumn and spring seasons. The air samples were collected with SAS Super 100(®) and the surface samples were collected by swab method. RESULTS: The UFC/m(3) counts found exceeded the acceptable levels. The UFC/m(3) and the diversity of Aspergillus species found in the Intensive Care Unit were higher than those found in the Burns Unit. The fungal load and the diversity of species within the units were higher than those in control environments. The use of both methods -SAS and swab- allowed the detection of a higher diversity of species, with 96 strains of Aspergillus being isolated and 12 species identified. The outstanding findings were Aspergillus sydowii, Aspergillus niger, Aspergillus flavus, Aspergillus terreus and Aspergillus parasiticus, due to their high frequency. Aspergillus fumigatus, considered unacceptable in indoor environments, was isolated in both units. CONCLUSIONS: Aspergillus was present with high frequency in these units. Several species are of interest in public health for being potential pathogenic agents. Air control and monitoring are essential in the prevention of these infections.

Native trees of the Northeast Argentine: natural hosts of the Cryptococcus neoformans-Cryptococcus gattii species complex.

BACKGROUND: In Argentina, information about epidemiology and environmental distribution of Cryptococcus is scarce. The city of Resistencia borders with Brazil and Paraguay where this fungus is endemic. All these supported the need to investigate the ecology of the genus and the epidemiology of cryptococcosis in this area. AIMS: The aim was to investigate the presence of species of Cryptococcus neoformans-Cryptococcus gattii complex and their genotypes in trees of the city of Resistencia. METHODS: One hundred and five trees were sampled by swabbing technique. The isolates were identified using conventional and commercial methods and genotyped by PCR-RFLP (Restriction Fragment Length Polymorphism). RESULTS: Cryptococcus was found in 7 out of the total trees. 6 out of 7 Cryptococcus isolates were identified as C. neoformans and one as C. gattii. C. gattii was isolated from Grevillea robusta. C. neoformans strains were isolated from Tabebuia avellanedae and Peltophorum dubium. Genotyping showed that all C. neoformans belonged to the VNI type and C. gattii belonged to the VGI type. CONCLUSIONS: This represents the first study on the ecology of Cryptococcus spp. associated to trees from northeastern Argentina, and the first report describing Grevillea robusta as a host of members of this fungal genus. Another finding is the isolation of C. neoformans from Tabebuia avellanedae and Peltophorum dubium, both tree species native to northeastern Argentina.

Aspergillus terreus complex: an emergent opportunistic agent of Onychomycosis.

The incidence of onychomycosis due to non-dermatophyte moulds (NDM) is increasing. Aspergillus terreus is relatively undocumented as an agent of this fungal infection. The aim of this work is to show the prevalence of onychomycosis caused by A. terreus and to describe its clinical features. Nail samples were collected for microscopic examination and culturing in selective media. All cases of onychomycosis due to NDM were confirmed by a second sample. Aspergillus terreus isolates were identified through their morphological characteristics and using molecular methods. A total of 2485 samples were obtained. Positive cultures were obtained in 1639 samples. From 124 NDM confirmed cultures, 23 were identified as A. terreus (18.5%). Superficial white onychomycosis was the most frequent clinical pattern. A high percentage was found in fingernails. The prevalence of A. terreus in this study considerably exceeded the percentages reported by other authors. Onychomycosis due to A. terreus presents similar clinical patterns to those caused by dermatophytes, but is difficult to eradicate and is associated with less predictable treatment outcomes. Better knowledge of the aetiology of A. terreus may be important for accomplishing more accurate and effective treatment.

[Prevalence of Malassezia species associated with seborrheic dermatitis lesions in patients in Argentina]. / Prevalencia de especies de Malassezia asociadas a lesiones de dermatitis seborreica en pacientes de Argentina.

BACKGROUND: Seborrheic dermatitis (SD) is considered the second most frequently dermatosis associated with the genus Malassezia but little is the knowledge about the epidemiology of this association. AIMS: To determinate the prevalence of Malassezia species associated with SD and to analyse their distribution according to the location of the lesion on the body. METHODS: This study was performed in Resistencia city, located in a subtropical area in northeast Argentina. In this study, 226 skin samples from patients with lesions compatible with SD were studied. Age, gender and body sites lesion were recorded. Strains were identified by PCR-RFLP. RESULTS: One hundred and thirty-one positive cultures were obtained. Association of 2 species was detected in 10 cases; therefore, 141 strains were isolated. Malasezzia globosa (43.3%) was the most frequent species isolated, followed by Malasezzia furfur (20.6%), Malasezzia sympodialis (17%) and Malasezzia restricta (16.3%). Three isolates of Malasezzia slooffiae (2.1%) and one of Malasezzia pachydermatis (0.7%) were obtained. Statistical significance (P<0.05) was found between M. globosa and scalp. Malasezzia restricta was isolated only in head areas. CONCLUSIONS: This study suggests M. globosa is the most related species to SD. The prevalence of other species is different from that reported by other authors. Only M. globosa and M. restricta presented a pattern of relationship with the body sites of the lesions. It is noteworthy is the isolation of the zoophylic species M. pachydermatis. The Malassezia genus ecology and the pathogenic role of its species are still under study. This work is a contribution to this knowledge.

Pitiriasis versicolor por Malassezia pachydermatis: caso clínico / Pityriasis versicolor caused by Malassezia pachydermatis: clinical case

Se presenta un caso clínico de pitiriasis versicolor por M. pachydermatis en una paciente de 11 años de edad, diagnosticado mediante clínica, morfofisiología y biología molecular. Malassezia pachydermatis es parte de la microbiota común de diversos mamíferos domésticos y animales salvajes. En éstos se reconoce como agente causal de dermatitis y otitis externa. En humanos se han descrito escasas infecciones ya sea superficiales como invasoras, lo que puede atribuirse a la difícil transmisión y adaptación a partir de los animales domésticos. Se comentan los aspectos biológicos y epidemiológicos de esta infección zoonótica.

A clinical case of pityriasis versicolor caused by M. pachydermatis in an 11 year old patient which was diagnosed by means of clinic, morphophysiology and molecular biology is presented. Malassezia pachydermatis is part of regular microbiota in several domestic mammals as well as wild animals. It is recognized as the causing agent of dermatitis and external otitis in the latter. As to human beings, superficial infections have rarely been given an invasive character what can be explained by the difficult transmission and adaptation coming from domestic animals. Biological and epidemiological aspects of this zoonotic infection are described.

Prevalence of Malassezia species in pityriasis versicolor lesions in northeast Argentina.

BACKGROUND: Malassezia species normally colonize the skin but they can change their saprophytic state and invade the stratum corneum as pathogens. AIMS: To determine the prevalence of Malassezia species isolated from patients with pityriasis versicolor (PV) and to analyse their distribution according to the location of the lesion on the body. METHODS: This study included 218 patients with PV and positive Malassezia cultures who resided in the city of Resistencia, a subtropical area located in northeast Argentina. Age, gender, and the body site of lesions were recorded. Strains were identified by PCR-RFLP. RESULTS: Malassezia sympodialis (37.7%) and Malassezia globosa (37.2%) were the most prevalent species isolated alone or in association with other Malassezia species in 82% of the patients. Malassezia furfur (21.3%) was the third most common species, followed by Malassezia slooffiae (1.7%), and Malassezia restricta (1.3%), which was found only in combination with M. globosa and M. sympodialis. Malassezia dermatis (0.4%) and Malassezia pachydermatis (0.4%) were each isolated once. None of the species affected a body site with statistical significance. Significant difference between genders according to age was found only in the 31-40-year-age group. CONCLUSIONS: This study suggests that M. sympodialis and M. globosa represent the main species implicated in the pathogenicity of PV. M. furfur appears to be the third agent of importance in this geographical area. Statistical analyses showed none of the species was particularly associated with any one of the body sites.

Actividad lipasa de especies de Malassezia aisladas en pacientes sanos y con lesiones dérmicas / Lipase activity of Malassezia species isolated from healthy patients and having dermic lesions

Las levaduras del género Malassezia forman parte de la micro biota normal de piel humana y animal. Excepto M. pachydermatis, todas las especies de este género son lipodependientes. Bajo ciertos factores, Malassezia se asocia como agente etiológico en diversas afecciones dérmicas. Uno de los principales factores de virulencia de estas levaduras es su actividad de lipasa (AL). El objetivo de este trabajo fue introducir modificaciones a las técnicas de determinación de la actividad lipasa (AL) para su aplicación en levaduras lipodependientes y estudiar la AL en cepas de Malassezia aisladas de personas con piel sana y de pacientes con pitiriasis versicolor (PV), dermatitis seborreica (DS) y psoriasis (PS). Se estudiaron 94 cepas aisladas de 34 pacientes con lesiones de PV, 20 con DS, 7 con PS y 33 cepas de personas con piel sana. Las modificaciones planteadas a la técnica, que incluyeron variación del medio de cultivo y tiempos de incubación, permitieron la determinación semi cuantitativa de la AL con resultados claros y definidos. El 88,23 por ciento de las cepas presentó AL. No se obtuvieron diferencias estadísticamente significativas al comparar la AL entre las cepas de pacientes con afecciones de piel y las cepas aisladas de personas sanas. La producción de lipasas de las especies de Malassezia en orden decreciente fue: M. sympodialis, M. slooffiae, M. furfur, M. globosa, M. restricta. M. globosa y M. furfur fueron las especies en que se observaron mayor cantidad de cepas no productoras de AL y cepas con gran variabilidad en la medida de AL.

Yeasts of the genus Malassezia are part of the regular microbiota in human and animal skin. Except for M. pachydermatis, all the species of this genus are lipodependent. Malassezia, under certain factors, is associated as an etiological agent in diverse dermic affections. One of the main virulence factors of these yeasts is their lipase activity (LA). The objective of this research was to introduce some changes in the techniques adopted to determine the lipase activity (LA) in order to apply them to lipodependent yeasts and to study likewise the LA in Malassezia strains isolated from healthy skin people and patients diagnosed with pitiriasis versicolor (VP), greasy dermatitis (GD) and psoriasis ( PS). Ninety four strains isolated from 34 patients having VP lesions, 20 with GD, 7 with PS and 33 strains from healthy skin people. Changes suggested to the technique involved a variation in the medium of culture as well as in the time of incubation what resulted in the semiquantitative determination of the LA together with clear and precise results. The presence of LA was observed in of 88.23 percent strains. The comparison of the LA among strains of patients bearing injured skin and those isolated from healthy skin did not show any significant statistical difference. The production of lipasae from Malassezia species were in decreasing order: M.sympodialis, M. slooffiae, M.furfur,M.globosa and M.restricta. M. globosa and M. furfur were the species that revealed the highest number of non producting LA strains as well as strains with the highest variability in the degree of LA.