Synergistic Antimicrobial Activity of Biogenic Silver Nanoparticles and Acanthospermum australe Essential Oil against Skin Infection Pathogens.

In response to the steady increase in antimicrobial-resistant strains, the World Health Organisation has emphasised the need to investigate new antimicrobial agents and alternative therapies that improve the spectrum of activity and reduce the dose required, thus improving safety. This study focused on the characterisation of Acanthospermum australe essential oil and green-synthesis silver nanoparticles (AgNP), evaluating their cytotoxicity in human cells, antimicrobial activity and synergistic effect against pathogens causing skin infections. The main components of the essential oil were germacrene A (24.07%), γ-cadinene (21.47%) and trans-caryophyllene (14.97%). Spherical AgNP with a diameter of 15 ± 3 nm were synthesised. The essential oil showed antimicrobial activity against dermatophytes and Malassezia globosa, while AgNP were found to be active against bacteria, yeasts and dermatophytes. Both compounds were found to be primarily non-cytotoxic at the concentrations required to inhibit microbial growth. Furthermore, the combined use of essential oil and AgNP showed a synergistic antimicrobial effect against dermatophytes and M. globosa. In conclusion, the results suggest that the combined use of bioactive compounds from natural sources, such as essential oil and biogenic AgNP, has the potential to improve antimicrobial efficacy against specific skin pathogens, particularly Microsporum canis, Nannizzia gypsea and M. globosa.

Impact of COVID-19 on paracoccidioidomycosis. Which was the most influential: The pandemic or the virus?

The impact of COVID-19 on paracoccidioidomycosis (PCM) in Argentina and the consequences generated by the pandemic are discussed. From 2018 to 3 years after the pandemic declaration, 285 proven PCM patients were registered. No association between both diseases was documented. PCM frequency decreased to extremely low levels in 2020. Mandatory social isolation and the emotional and psychological effects generated under pandemic circumstances led to delays in diagnosis, severe disseminated cases, and other challenges for diagnosis in subsequent years. Probable underdiagnosis should be considered due to the overlap of clinical manifestations, the low index of suspicion and the lack of sensitive diagnostic tools.

Proceedings of the second international meeting on endemic mycoses of the Americas (IMEMA) and first international symposium on implantation mycoses (ISIM).

The second international meeting on endemic mycoses of the Americas (IMEMA) and the first international symposium on implantation mycoses (ISIM) took place in Santiago del Estero, Argentina, on September 25-27, 2023. The conference provided a platform for researchers, clinicians, and experts to discuss the latest developments in the field of endemic and implantation mycoses. Topics included epidemiology, diagnostic advances, treatment strategies, and the impact of environmental factors on the spread of these fungal diseases. IMEMA and ISIM contributed to the regional discourse on the mycoses, emphasizing the importance of international cooperation in addressing these public health challenges.

IMEMA/ISIM, held in Santiago del Estero, Argentina, convened experts to discuss endemic and implantation mycoses, covering topics such as epidemiology, diagnostics, treatment, and advocacy. The event highlighted ongoing efforts in combating these diseases.

Epidemiology of coccidioidomycosis in Argentina, an update.

The National Reference Laboratory in Clinical Mycology of Argentina conducted a retrospective review of human coccidioidomycosis cases diagnosed by the National Mycology Laboratory Network of Argentina between 2010 and 2022 to determine the burden of the disease in the country. A total of 100 human coccidioidomycosis cases were documented, with a higher prevalence in male patients (male-to-female ratio of 1.9:1), with a median age of 41 years. Comparing the number of cases between two 10-year periods (2000-2009 and 2010-2019), the increase was 36.51% (from 63 to 86 cases). Among the 100 recorded cases, 79 tested positive using the double immunodiffusion test. Spherules were observed in 19 cases through histopathology or direct microscopic examination and the fungus was isolated in 39 cases. Thirty-six isolates were identified as Coccidioides posadasii through partial sequencing of the Ag2/PRA gene. Catamarca province had the highest number of cases, comprising 64% of the total, with an incidence rate above 1.0-2.5/100,000 inhabitants until 2018. However, there has been a recent downward trend in the region from 2018 to 2022. It is concerning that more than half of diagnosed cases were chronic pulmonary or disseminated forms, indicating a lack of early disease detection. To rectify this issue, it is imperative to conduct targeted training programs for healthcare personnel and enhance public awareness within the endemic area. This will contribute to a better understanding of the true burden of coccidioidomycosis and enable the implementation of appropriate sanitary control measures.

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.

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.

Evaluación clínica y microbiológica usando tres técnicas de eliminación de tejido cariado / Avaliação clínica e microbiológica de três técnicas para eliminação do tecido cariado / Root fracture in the permanent maxillary central incisors: a case report of 10 years follow-up

Objetivo: Comparar, la efectividad clínica y microbiológica, entre las técnicas de eliminación tradicional y químico-mecánicas, para el tratamiento de lesiones cavitadas abiertas no penetrantes en dientes primarios en niños de 4 a 8 años, analizándose 57 dientes primarios. Grupo I: técnica tradicional (19 piezas), Grupo II: Brix (18 piezas), Grupo III: Papacarie (20 piezas). Evaluación clínica (necesidad de anestesiar y tiempo de ejecución) los datos fueron asentados en cada historia clínica. Antes y después del procedimiento operatorio, se tomaron muestras de la cavidad con microbrush estéril, transportándolas en tioglicolato para analizar cuantitativamente el total de bacterias presente por mililitro, utilizando cultivos de agar sangre (base Columbia). La información fue tabulada y analizada estadísticamente mediante Análisis de la Variancia, pruebas de Tukey y de Chi Cuadrado, estableciéndose como criterio de significancia p≤0.05. La diferencia significativa en la cantidad de bacterias entre el grupo I (41.22 ± 4.45) y los grupos II y III (65.96 ± 4.33, 83.45 ± 4.57), reveló que el grupo I fue menos efectivo. En los grupos II y III no se requirió la utilización de anestesia, siendo significativa la diferencia en los niños de edad preescolar (4 y 5 años). El tiempo de ejecución para cada técnica manifestó mayor rapidez en el grupo I (2.12 min ± 0.15) p˂0.0001. Las técnicas que utilizan algún agente químico permiten una mayor eliminación de bacterias durante la remoción de tejido cariado, sin recurrir a anestesia, por lo que pueden ser recomendadas como alternativa al tratamiento tradicional especialmente en niños pequeños.

Objetivo. Este estudo pretende comparar a eficácia clínica e microbiológica de três técnicas para a eliminação do tecido cariado, em crianças dos 4 aos 8 anos. Materiais e Método. Cinquenta e sete dentes decíduos foram analisados. Grupo I: técnica tradicional (19 dentes), Grupo II: Brix (18 dentes), Grupo III: Papacarie (20 dentes). Os dados para avaliação clínica (necessidade de anestesia e tempo de execução) foram registrados em cada anamnese. Antes e após o procedimento operatório, foram retiradas amostras da lesão cariosa com microbrush estéril, transportadas em tioglicolato para análise quantitativa do total de bactérias presentes por mililitro, utilizando culturas de ágar sangue (base Columbia). A informaçâo foi tabulada e analisada estatisticamente por meio do Analize da Varianza, testes de Tukey e do Qui-Quadrado, estabelecendo-se p≤0.05 como critério de significância. Resultados. A diferença na cantidade de bactérias entre o grupo I (41.22 ± 4.45), II e III (65.96 ± 4.33, 83.45 ± 4.57), revelou que o grupo I foi menos eficaz. Os grupos II e III não necessitaram do uso de anestesia, sendo a diferença significativa no grupo de pré-escolares (4 e 5 anos). O tempo de execução de cada técnica foi mais rápido no grupo I (2.12 min ± 0.15) p˂0.0001. Conclusão. As técnicas que utilizam algum agente químico permitem uma maior eliminação de bactérias durante a remoção do tecido cariado, sem recorrer à anestesia, podendo ser recomendadas como alternativa ao tratamento tradicional, especialmente em crianças pequenas.

Aim. This study pretends to compare the clinical and microbiological effectiveness of three techniques for the elimination of carious tissue in children aged 4 to 8 years old. Methods. Fifty-seven primary teeth were analyzed. Group I: traditional technique (19 teeth), Group II: Brix (18 teeth), Group III: Papacarie (20 teeth). The data for clinical evaluation (need for anesthesia and running time) were recorded in each case history. Before and after the operative procedure, samples were taken from the carious lesion with sterile micro brush, transported in thioglycollate to quantitatively analyze the total bacteria present per milliliter, using blood agar cultures (Columbia base). Information was tabulated and statistically analyzed using Analysis of Variance, Tukey's and Chi Square tests, establishing p≤0.05 as the criterion of significance. Results. The difference on number of bacteria between group I (41.22 ± 4.45), and groups II and III (65.96 ± 4.33, 83.45 ± 4.57), revealed that group I was less effective. Groups II and III did not require the use of anesthesia, the difference being significant in the group of pre-school children (4 and 5 years old). The execution time for each technique was faster in group I (2.12 min ± 0.15) p˂0.0001. Conclusions. Techniques that use some chemical agents allow a greater elimination of bacteria during the removal of carious tissue, without resorting to anesthesia, can be recommended as an alternative to traditional treatment especially in young children.

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.

Biogenic silver nanoparticles as antifungal agents.

In recent years, an increase in multidrug-resistant fungal strains has been observed, which, together with the limited number of clinically available antifungal agents, highlights the need for the development of new antifungal agents. Due to the proven antifungal activity of silver nanoparticles (AgNPs), there is a growing interest in their use in the treatment of fungal infections. Nanoparticles are usually synthesised through a variety of physical and chemical processes that are costly and pollute the environment. For this reason, biogenic synthesis is emerging as an environmentally friendly technology and new strategies are increasingly based on the use of biogenic AgNPs as antifungal agents for clinical use. The aim of this review is to compare the antifungal activity of different biogenic AgNPs and to summarise the current knowledge on the mechanisms of action and resistance of fungi to AgNPs. Finally, a general analysis of the toxicity of biogenic AgNPs in human and veterinary medicine is performed.

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.

Usefulness of Sona Aspergillus Galactomannan LFA with digital readout as diagnostic and as screening tool of COVID-19 associated pulmonary aspergillosis in critically ill patients. Data from a multicenter prospective study performed in Argentina.

COVID-19-associated pulmonary aspergillosis (CAPA) incidence varies depending on the country. Serum galactomannan quantification is a promising diagnostic tool since samples are easy to obtain with low biosafety issues. A multicenter prospective study was performed to evaluate the CAPA incidence in Argentina and to assess the performance of the lateral flow assay with digital readout (Sona Aspergillus LFA) as a CAPA diagnostic and screening tool. The correlation between the values obtained with Sona Aspergillus LFA and Platelia® EIA was evaluated. In total, 578 serum samples were obtained from 185 critically ill COVID patients. CAPA screening was done weekly starting from the first week of ICU stay. Probable CAPA incidence in critically ill patients was 10.27% (19/185 patients when LFA was used as mycological criteria) and 9% (9/100 patients when EIA was used as mycological criteria). We found a very good correlation between the two evaluated galactomannan quantification methods (overall agreement of 92.16% with a Kappa statistic value of 0.721). CAPA diagnosis (>0.5 readouts in LFA) were done during the first week of ICU stay in 94.7% of the probable CAPA patients. The overall mortality was 36.21%. CAPA patients' mortality and length of ICU stay were not statistically different from for COVID (non-CAPA) patients (42.11 vs 33.13% and 29 vs 24 days, respectively). These indicators were lower than in other reports. LFA-IMMY with digital readout is a reliable tool for early diagnosis of CAPA using serum samples in critically ill COVID patients. It has a good agreement with Platelia® EIA. LAY SUMMARY: The incidence of COVID-associated pulmonary aspergillosis (CAPA) in critically-ill Argentinian patients was established (10.27%). Serum galactomannan quantification was useful as a screening tool for this mycosis. A good agreement between Platelia® EIA and Sona Aspergillus LFA is reported.

Utilidad del panel Sensititre YeastOne® para detectar especies de Candida resistentes a los antifúngicos / Usefulness of the Sensititre YeastOne® panel to detect Candida species resistant to antifungal drugs

Resumen Evaluamos las concordancias interlaboratorio, esencial y categórica entre el panel Sensititre YeastOne™ y los métodos de referencia correspondientes al M27 4.a ed. (Clinical and Laboratory Standards Institute [CLSI]) y al EDef 7.3.1 (European Committee on Antifungal Susceptibility Testing [EUCAST]). Estudiamos 67 cepas de Candida de distintas muestras clí nicas y un panel de 9 cepas resistentes a fluconazol y equinocandinas. El mayor porcentaje de concordancia interlaboratorio se observó con anfotericina B (96,8%) y el menor porcen taje con voriconazol (77,2%). La caspofungina mostró un 5,8% de discrepancias muy mayores con el método de referencia del CLSI. Con el del EUCAST, el itraconazol, el posaconazol y la anidulafungina mostraron porcentajes de discrepancias mayores: el 17,6, el 18,1 y el 19,6%, respectivamente. El panel Sensititre YeastOne™ es una alternativa confiable y fácil de usar, que permite detectar especies de Candida resistentes a los antifúngicos, con algunas limitaciones para las equinocandinas. Los resultados son equiparables a los de los métodos de referencia.

Abstract We evaluated the interlaboratory agreement, the essential agreement, and the cate- gorical agreement between the Sensititre YeastOne™ panel and the reference methods M27 4th Edition of the Clinical and Laboratory Standards Institute (CLSI), and the EDef 7.3.1 of the Euro- pean Committee on Antifungal Susceptibility Testing (EUCAST). We studied 67 Candida strains isolated from different clinical samples and 9 Candida strains with resistance to fluconazole and echinocandins. The highest percentage of interlaboratory agreement was observed with amp- hotericin B (96.8%), and the lowest percentage with voriconazole (77.2%). Caspofungin showed 5.8% of very major errors when compared with the CLSI reference method. For EUCAST, itraconazole, posaconazole, and anidulafungin showed high percentages of major errors: 17.6%, 18.1%, and 19.6%, respectively. Sensititre YeastOne™ is a reliable alternative, and easy to perform for detecting Candida species resistant to antifungal drugs, with some limitations for echinocandins. Results are comparable to those of the reference methods.

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.

[Usefulness of the Sensititre YeastOne® panel to detect Candida species resistant to antifungal drugs]. / Utilidad del panel Sensititre YeastOne® para detectar especies de Candida resistentes a los antifúngicos.

We evaluated the interlaboratory agreement, the essential agreement, and the categorical agreement between the Sensititre YeastOneTM panel and the reference methods M27 4th Edition of the Clinical and Laboratory Standards Institute (CLSI), and the EDef 7.3.1 of the European Committee on Antifungal Susceptibility Testing (EUCAST). We studied 67 Candida strains isolated from different clinical samples and 9 Candida strains with resistance to fluconazole and echinocandins. The highest percentage of interlaboratory agreement was observed with amphotericin B (96.8%), and the lowest percentage with voriconazole (77.2%). Caspofungin showed 5.8% of very major errors when compared with the CLSI reference method. For EUCAST, itraconazole, posaconazole, and anidulafungin showed high percentages of major errors: 17.6%, 18.1%, and 19.6%, respectively. Sensititre YeastOneTM is a reliable alternative, and easy to perform for detecting Candida species resistant to antifungal drugs, with some limitations for echinocandins. Results are comparable to those of the reference methods.

Antimicrobial and cytotoxic activity of green synthesis silver nanoparticles targeting skin and soft tissue infectious agents.

Combining traditional medicine with nanotechnology therefore opens the door to innovative strategies for treating skin and soft tissue infections (SSTIs) and also contributes to the fight against the rise of antimicrobial resistance. Acanthospermum australe (Loefl.) Kuntze is a medicinal plant used by indigenous peoples in northeastern Argentina to treat SSTIs. Spherical and stable silver nanoparticles (AgNPs) of 14 ± 2 nm were synthesized from the aqueous extract of A. australe and silver nitrate. The antimicrobial activity against main species causing SSTIs and cytotoxicity on peripheral blood mononuclear cells of AgNP solution and its synthesis components were evaluated. Compared to its synthesis components, AgNP solution showed greater antimicrobial activity and lower cytotoxicity. The antimicrobial activity of AgNPs was due to the silver and not to the metabolites of the aqueous extract present on the surface of the nanoparticles. The plant extract played an important role in the formation of stable AgNPs and acted as a modulator of cytotoxic and immune responses.

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.

The Trojan Horse Model in Paracoccidioides: A Fantastic Pathway to Survive Infecting Human Cells.

Paracoccidioidomycosis (PCM) is the most relevant systemic endemic mycosis limited to Latin American countries. The etiological agents are thermally dimorphic species of the genus Paracoccidioides. Infection occurs via respiratory tract by inhalation of propagules from the environmental (saprophytic) phase. In the lung alveoli the fungus converts to the characteristic yeast phase (parasitic) where interact with extracellular matrix proteins, epithelial cells, and the host cellular immunity. The response involves phagocytic cells recognition but intracellular Paracoccidioides have demonstrated the ability to survive and also multiply inside the neutrophils, macrophages, giant cells, and dendritic cells. Persistence of Paracoccidioides as facultative intracellular pathogen is important in terms of the fungal load but also regarding to the possibility to disseminate penetrating other tissues even protected by the phagocytes. This strategy to invade other organs via transmigration of infected phagocytes is called Trojan horse mechanism and it was also described for other fungi and considered a factor of pathogenicity. This mini review comprises a literature revision of the spectrum of tools and mechanisms displayed by Paracoccidioides to overcame phagocytosis, discusses the Trojan horse model and the immunological context in proven models or the possibility that Paracoccidioides apply this tool for dissemination to other tissues.

Candida auris infection in the central catheter of a patient without sepsis symptoms / Infección por Candida auris en el catéter central de un paciente sin síntomas de sepsis

Abstract Background: Candida auris is an emerging yeast frequently reported as resistant to multiple antifungal drugs commonly used to treat Candida infections. This specie can colonize the patient's skin and has great ability for producing outbreaks in hospitals. C. auris is phylogenetically related to other Candida species, can be misidentified using conventional biochemical or commercial methods and requires specific technology for its identification. Case report: We report the first isolate of C. auris in Cali, Colombia, from a central venous catheter in a 37-year-old patient with rheumatoid arthritis and endocarditis who did not have symptoms of sepsis. The yeast was initially misidentified as C. haemulonii using the Phoenix system and subsequently identified as C. auris by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS). The broth microdilution method was used to determine the minimum inhibitory concentration; the isolate was susceptible to fluconazole, itraconazole, voriconazole and amphotericin B. Conclusions: This report contributes to knowledge of the epidemiology of C. auris infections in individuals with underlying disease and describes an isolate with a behavior different from what is usually reported.

Resumen Antecedentes: Candida auris es una levadura emergente, informada con frecuencia como resistente a diversos antifúngicos usados comúnmente para tratar infecciones por Candida. Esta especie puede colonizar la piel y tiene gran capacidad de producir brotes en ambientes hospitalarios. Está filogenéticamente relacionada con otras especies de Candida, es mal identificada por los métodos bioquímicos o comerciales, y requiere tecnología específica para su identificación. Reporte de caso: Se informa el primer aislamiento de C. auris en Cali, Colombia en un paciente de 37 años con artritis reumatoide y endocarditis, sin síntomas de sepsis, a partir de la punta de catéter venoso central. La levadura inicialmente se identificó como C. haemulonii por el sistema Phoenix® y posteriormente como C. auris por espectrometría de masas desorción/ionización láser asistida por una matriz con detección de masas por tiempo de vuelo (MALDI-TOF MS). Se determinó la concentración inhibitoria mínima por el método de microdilución en caldo que mostró un aislamiento sensible a fluconazol, itraconazol, voriconazol y anfotericina B. Conclusión: Este informe contribuye al conocimiento de la epidemiología de las infecciones por C. auris en individuos con enfermedad subyacente y describe un aislamiento con un comportamiento diferente a lo indicado en otros estudios.

Especies de Malassezia causantes de pitiriasis versicolor en Paraguay / Malassezia species causative of pityriasis versicolor in Paraguay

Resumen Introducción: La pitiriasis versicolor es una patología frecuente en Paraguay; sin embargo, su epidemiologia es desconocida. Objetivo: Determinar la frecuencia de especies de Malassezia causantes de pitiriasis versicolor y las características epidemiológicas de la población. Materiales y Métodos: Se recolectaron muestras de pacientes con diagnóstico presuntivo de pitiriasis versicolor. El diagnóstico de laboratorio se realizó mediante examen en fresco y cultivo en agar Dixon modificado y agar cromogénico Chromagar Malassezia®, incubados a 32°C; y la identificación por las características macro y micromorfológicas, pruebas bioquímicas y fisiológicas. Resultados: Se incluyeron 102 pacientes (51% femenino), de 1 mes a 63 años de edad, predominando el grupo de 11 a 20 años (35,3%). La localización más frecuente fue el dorso (60,8%). Predominaron las formas hipocrómicas (48%). La especie más frecuente fue M. globosa (52,9%), seguida de M. furfur (24,5%), M. sympodialis (18,6%) y M. slooffiae (6,9%). Conclusiones: La epidemiología observada es similar a otros estudios sudamericanos, no hace distinción de sexo, se presenta predominantemente en la forma clínica hipocrómica y M. globosa aparece como principal responsable. Este es el primer reporte sobre las especies causantes de pitiriasis versicolor en Paraguay y las características de la población con esta patología.

Background: Pityriasis versicolor is a frequent pathology in Paraguay; however, its epidemiology is unknown. Aim: To determine the frequency of Malassezia species causing pityriasis versicolor and the epidemiological characteristics of the population. Methods: Samples from patients with a presumptive diagnosis of pityriasis versicolor were collected. Laboratory diagnosis was carried out by fresh examination and culture in modified Dixon agar and chromogenic Chromagar Malassezia®, incubated at 32° C, and identification by macro and micromorphological features, biochemical and physiological tests. Results: 102 patients were included (51% female) from 1 month to 63 years of age, the predominant age group was 11-20 years (35.3%). The most frequent location was on the back (60.8%). Hipocromic clinical forms (48%) predominated. The most frequent species was M. globosa (52.9%), followed by M. furfur (24.5%), M. sympodialis (18.6%) and M. slooffiae (6.9%). Conclusions: The observed epidemiology is similar to other South American studies, with no sex distinction, predominantly hypochromic clinical form and as primary responsible species appears M. globosa. This is the first report on species causing pityriasis versicolor in Paraguay and the characteristics of the affected population.

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.