Discovery and validation of serologic biomarkers for the diagnosis and prognosis of invasive candidiasis by computational immunomics

Invasive candidiasis (IC) is an opportunistic systemic mycosis caused by Candida species (commonly Candida albicans) that continues to pose a significant public health problem worldwide. Despite great advances in antifungal therapy and changes in clinical practices, IC remains a major infectious cause of morbidity and mortality in severely immunocompromised or critically ill patients, and further accounts for substantial healthcare costs. Its impact on patient clinical outcome and economic burden could be ameliorated by timely initiation of appropriate antifungal therapy. However, early detection of IC is extremely difficult because of its unspecific clinical signs and symptoms, and the inadequate accuracy and time delay of the currently available diagnostic or risk stratification methods. In consequence, the diagnosis of IC is often attained in advanced stages of infection (leading to delayed therapeutic interventions and ensuing poor clinical outcomes) or, unfortunately, at autopsy. In addition to the difficulties encountered in diagnosing IC at an early stage, the initial therapeutic decision-making process is also hindered by the insufficient accuracy of the currently available tools for predicting clinical outcomes in individual IC patients at presentation. Therefore, it is not surprising that clinicians are generally unable to early detect IC, and identify those IC patients who are most likely to suffer fatal clinical outcomes and may benefit from more personalized therapeutic strategies at presentation. Better diagnostic and prognostic biomarkers for IC are thus needed to improve the clinical management of this life-threatening and costly opportunistic fungal infection...

Candida albicans Modifies the Protein Composition and Size Distribution of THP1 macrophages-derived Extracellular Vesicles.

The effectiveness of macrophages in the response to systemic candidiasis is crucial to an effective clearance of the pathogen. The secretion of proteins, mRNAs, non-coding RNAs and lipids through extracellular vesicles (EVs) is one of the mechanisms of communication between immune cells. EVs change their cargo to mediate different responses, and may play a role in the response against infections. Thus, we have undertaken the first quantitative proteomic analysis on the protein composition of THP1 macrophages-derived EVs during the interaction with Candida albicans. This study revealed changes in EVs sizes and in protein composition, and allowed the identification and quantification of 717 proteins. Of them, 133 proteins changed their abundance due to the interaction. The differentially abundant proteins were involved in functions relating to immune response, signaling, or cytoskeletal reorganization. THP1-derived EVs, both from control and from Candida-infected macrophages, had similar effector functions on other THP1-differenciated macrophages, activating ERK and p38 kinases, and increasing both the secretion of proinflammatory cytokines and the candidacidal activity; while in THP1 non-differenciated monocytes, only EVs from infected macrophages increased significantly the TNF-α secretion. Our findings provide new information on the role of macrophage-derived EVs in response to C. albicans infection and in macrophages communication.

Desarrollo de nuevas formulaciones tópicas de anfotericina B para el tratamiento de micosis

Las infecciones por hongos se han convertido en un tema de gran preocupación en todo el mundo, se estima que más de 40 millones de personas sufren infecciones por hongos, tanto en países desarrollados como en países en vías de desarrollo (Güngör, et al., 2013). Las micosis superficiales se encuentran entre las formas más frecuentes de infecciones en los humanos. Se estima que afectan un 20-25 % de la población mundial y su incidencia está constantemente en aumento (Vena, et al., 2012) (Havlickova, et al., 2008) (Das, et al., 2007). Actualmente, este tipo de infecciones son un frecuente motivo de consulta para el médico de familia (Hernández, et al., 2014) y el dermatólogo. Lo cual nos obliga a permanecer constantemente actualizados La candidiasis es la micosis emergente con mayor efecto en el ser humano debido a su frecuencia y a la gravedad de sus complicaciones (López-Martínez, R., 2010). La candidiasis superficial es una de las formas clínicas más comunes. Es característicamente crónica y recurrente, y, a veces, indica el comienzo de las formas graves de esta micosis (Pappas, et al., 2009). Las levaduras del género Candida son microorganismos pertenecientes a la microbiota normal de individuos sanos, principalmente en la mucosa oral, el tracto gastrointestinal y el tracto genitourinario femenino (Shao, et al., 2007). Sin embargo, estos hongos son responsables de diferentes manifestaciones clínicas, especialmente en pacientes inmunocomprometidos, que van desde infecciones de la piel y mucosas a infecciones sistémicas (Sardi, et al., 2013). Su importancia viene de la alta frecuencia con que colonizan e infectan el huésped humano (De Bernardis, et al., 2004), siendo el cuarto patógeno más común asociado con los casos de infección nosocomial (Wisplinghoff, et al., 2004)...

Single-nucleotide polymorphism in two representative multidrug-resistant Mycobacterium bovis isolates collected from patients in a Spanish hospital harboring a human infection outbreak

Mycobacterium bovis is the etiological agent of tuberculosis in domestic and wild animals. Its involvement as a human pathogen has been highlighted again with the recent descriptions of transmission through dairy products (18), reactivation or primary infection in human immunodeficiency virus-infected patients (5), and association with meat industry workers, animal keepers, or hunters (3). Strains resistant to antituberculous drugs (M. bovis is naturally resistant to pyrazinamide) pose an additional risk (2). Several studies have demonstrated that mutations in target genes are associated with resistance to antituberculous drugs (4, 7, 10, 11, 16). However, most of them have been developed in Mycobacterium tuberculosis strains and limited data are available regarding M. bovis isolates. The aim of this study was to characterize by sequencing the main genes involved in antibiotic resistance in two multidrug-resistant (MDR) M. bovis isolates in a human outbreak detected in a hospital in Madrid that subsequently spread to several countries (5, 6, 15). The isolates were resistant to 11 drugs, but only their rpoB and katG genes have been analyzed so far (1, 14). We studied the first (93/R1) and last (95/R4) M. bovis isolates of this nosocomial outbreak, characterized by spoligotyping as SB0426 (hexacode 63-5F-5E-7F-FF-60 in the database at www.mbovis.org) (1, 13). Several genes involved in resistance to isoniazid (katG, ahpC, inhA, and the oxyR-ahpC intergenic region), rifampin (rpoB), streptomycin (rrs, rpsL), ethambutol (embB), and quinolones (gyrA) were studied. These genes, or fragments of genes, were amplified and sequenced as previously described (12). The sequence analysis revealed polymorphisms in five (ahpC, rpoB, rpsL, embB, and gyrA) out of nine analyzed genes (Table 1). Nucleotide substitutions in four genes cause a change in the encoded amino acid. Two additional synonymous mutations in ahpC and rpsL differentiated the first and last isolates from the outbreak.

Estudio proteómico de las vesículas extracelulares y del secretoma de "Candida albicans" y análisis funcional de proteínas de superficie celular

Candida albicans es un importante patógeno oportunista en humanos, que puede causar distintos tipos de infecciones, desde micosis superficiales hasta sistémicas. La candidiasis invasiva es una enfermedad que puede causar mortalidad en pacientes inmunocomprometidos. Para causar daño en el hospedador, C. albicans cuenta con una serie de factores de virulencia. Entre ellos destaca la capacidad de cambiar su forma de crecimiento de levadura a hifa. La superficie celular es la estructura más externa de la célula y el punto de contacto entre el hongo y el hospedador. Las proteínas de superficie tienen un papel importante en la integridad estructural de la célula y en la adherencia e invasión de células del hospedador. Una de las proteínas localizadas en la superficie celular es Ecm33, una proteína de pared celular con anclaje glicosilfosfatidilinositol (GPI). La deleción de esta proteína afecta a la morfología tanto de levaduras como de hifas, dando como resultado células con la pared celular alterada y virulencia reducida tanto en condiciones in vitro como in vivo. El secretoma o las proteínas secretadas por C. albicans son también relevantes en la interacción patógeno-hospedador. C. albicans secreta muchas proteínas importantes relacionadas con diferentes procesos, entre los que se incluyen la formación de biofilms, la adquisición de nutrientes y el mantenimiento de la integridad de la pared celular. Muchas de estas proteínas secretadas, como las pertenecientes a las familias de aspartil proteasas (Sap) y la familia de fosfolipasas B (Plb), también han sido detectadas en la pared celular, ya que deben pasar a través de ella en su tránsito hacia el medio extracelular. Estas proteínas tienen un péptido señal en el extremo N-terminal que es el responsable de dirigirlas a la ruta clásica de secreción. Sin embargo, cerca de un tercio de las proteínas identificadas en el medio extracelular de C. albicans no poseen dicho péptido señal en su secuencia...