Of fungi and ticks: Morphological and molecular characterization of fungal contaminants of a laboratory-reared Ixodes ricinus colony

• Published in: Ticks and tick-borne diseases Vol. 12; no. 5; p. 101732
• Main Authors: Bonnet, Sarah I., Blisnick, Thierry, Al Khoury, Charbel, Guillot, Jacques
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier GmbH 01.09.2021; Elsevier
• Subjects: Animal biology; Aspergillus parasiticus; disease transmission; Ecology, environment; fungal contamination; fungal growth; humidity; Invertebrate Zoology; Ixodes ricinus; laboratory rearing; Life Sciences; microscopy; mortality; Penicillium; Penicillium steckii; saprophytes; Scopulariopsis; Scopulariopsis brevicaulis; Symbiosis; Tick; Tick colony; tick control; ticks; Veterinary medicine and animal Health; Aspergillus parasiticus; Tick colony; Tick; Scopulariopsis brevicaulis; Ixodes ricinus; Penicillium steckii
• ISSN: 1877-959X; 1877-9603; 1877-9603
• DOI: 10.1016/j.ttbdis.2021.101732

Establishing and maintaining tick colonies in the laboratory is essential for studying their biology and pathogen transmission, or for the development of new tick control methods. Due to their requirement for very high humidity, these laboratory-bred colonies are frequently subject to fungal contamination. In the present study, we aimed to identify the fungal species that contaminated a laboratory-reared colony of Ixodes ricinus through microscopic observation and molecular identification. We identified three different taxa isolated from the ticks: Aspergillus parasiticus, Penicillium steckii, and Scopulariopsis brevicaulis. These three species are usually regarded as environmental saprophytic molds but both direct and indirect evidence suggest that they could also be considered as entomopathogenic fungi. Although we do not have any direct evidence that the fungi isolated from I. ricinus in this study could cause lethal infections in ticks, we observed that once infected, heavy fungal growth coupled with very high mortality rates suggest that studying the entomopathogenic potential of these fungi could be relevant to biological tick control.