Gómez Moracho, TamaraBuendía Abad, MaríaBenito Murcia, MaríaGarcía Palencia, PilarBarrios, LauraBartolomé Husson, CarolinaMaside Rodríguez, Xulio ManuelMeana Mañes, María AránzazuJiménez Antón, María DoloresOlías Molero, Ana IsabelAlunda Rodríguez, José MaríaMartín Hernández, RaquelHiges Pascual, Mariano2025-01-142025-01-142020-08-18Tamara Gómez-Moracho, María Buendía-Abad, María Benito, Pilar García-Palencia, Laura Barrios, Carolina Bartolomé, Xulio Maside, Aránzazu Meana, María Dolores Jiménez-Antón, Ana Isabel Olías-Molero, José María Alunda, Raquel Martín-Hernández, Mariano Higes, Experimental evidence of harmful effects of Crithidia mellificae and Lotmaria passim on honey bees, International Journal for Parasitology, Volume 50, Issue 13, 2020, Pages 1117-1124, ISSN 0020-7519, https://doi.org/10.1016/j.ijpara.2020.06.0090020-7519https://hdl.handle.net/10347/38541The trypanosomatids Crithidia mellificae and Lotmaria passim are very prevalent in honey bee colonies and potentially contribute to colony losses that currently represent a serious threat to honey bees. However, potential pathogenicity of these trypanosomatids remains unclear and since studies of infection are scarce, there is little information about the virulence of their different morphotypes. Hence, we first cultured C. mellificae and L. passim (ATCC reference strains) in six different culture media to analyse their growth rates and to obtain potentially infective morphotypes. Both C. mellificae and L. passim grew in five of the media tested, with the exception of M199. These trypanosomatids multiplied fastest in BHI medium, in which they reached a stationary phase after around 96 h of growth. Honey bees inoculated with either Crithidia or Lotmaria died faster than control bees and their mortality was highest when they were inoculated with 96 h cultured L. passim. Histological and Electron Microscopy analyses revealed flagellated morphotypes of Crithidia and Lotmaria in the lumen of the ileum, and adherent non-flagellated L. passim morphotypes covering the epithelium, although no lesions were evident. These data indicate that parasitic forms of these trypanosomatids obtained from the early stationary growth phase infect honey bees. Therefore, efficient infection can be achieved to study their intra-host development and to assess the potential pathogenicity of these trypanosomatidseng© 2020 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reservedLotmaria passimCrithidia mellificaeCulture mediaMorphotypesExperimental infectionHoney bee survival2401 Biología animal (zoología)journal article10.1016/j.ijpara.2020.06.0091879-0135open access