Adherence Patterns of Histoplasma capsulatum Yeasts to Bat Tissue Sections Roberto Osvaldo Sua ´rez-Alvarez • Armando Pe ´rez-Torres • Maria Lucia Taylor Received: 25 July 2009 / Accepted: 10 March 2010 / Published online: 27 March 2010 Ó Springer Science+Business Media B.V. 2010 Abstract The adherence of Histoplasma capsula- tum yeasts to lung, spleen, liver, gut, and trachea cryosections of Artibeus hirsutus bats and inbred BALB/c mice (control) was studied after in vitro yeast-tissue incubations. Candida albicans yeasts were used as a well-known adherent fungal model in the mice host, and latex beads were used as a negative adherence control. Adhered yeast cells were identified by using crystal violet staining and the immunoperoxidase method with specific antibodies. H. capsulatum yeasts adhered to all tissues tested, mainly in the lung. Moreover, H. capsulatum yeasts adhered preferentially to white and red spleen pulp, in contrast to the dispersed distribution of C. albicans yeasts. H. capsulatum yeasts were mostly found on the sinusoidal face of hepatocytes. In general, the gut showed a higher number of adhered H. capsulatum yeasts than the trachea in both bats and mice. H. capsulatum and C. albicans yeasts developed high selectivity for the lamina propria of the gut. In addition, H. capsulatum yeasts interacted better with the lamina propria and adventitia of the trachea. The number of H. capsulatum yeast cells that adhered to each tissue section type was always greater than the corresponding number of C. albicans yeast cells, and latex beads never adhered to the tissue sections. Controls with anti-H. capsulatum and normal rabbit sera showed a significant blockage of H. capsulatum yeast adherence to lung tissue. This is the first study describing the patterns of H. capsulatum yeast adherence to different bat and mouse tissues. Keywords H. capsulatum Á Bats Á Mice Á Yeast adherence Á Tissues Introduction The dimorphic fungus, Histoplasma capsulatum var. capsulatum—Darling 1906, is the aetiological agent of the systemic mycosis named histoplasmosis. This fungus is associated with ecological niches that include bat and bird guano [1]. The highest risk of the acquisition of histoplasmosis is related to incur- sion into spaces where fungal mycelial-infective propagules are inhaled and can cause disease with a mild-to-severe clinical course, especially in immu- nocompromised hosts. Generally, enclosed spaces are used by bats as permanent and/or temporary shelters, and they represent a health risk for all individuals R. O. Sua ´rez-Alvarez Á M. L. Taylor (&) Departamento de Microbiologı ´a-Parasitologı ´a, Facultad de Medicina, Universidad Nacional Auto ´noma de Me ´xico (UNAM), 04510 Me ´xico DF, Mexico e-mail: emello@servidor.unam.mx; luciataylor@yahoo.com.mx R. O. Sua ´rez-Alvarez Á A. Pe ´rez-Torres Departamento de Biologı ´a Celular-Tisular, Facultad de Medicina, Universidad Nacional Auto ´noma de Me ´xico (UNAM), 04510 Mexico City, Mexico 123 Mycopathologia (2010) 170:79–87 DOI 10.1007/s11046-010-9302-9