Interaction between fungi communities and Pediculus humanus capitis..

ATONNATTY GABRIELA ; CERIANI-NAKAMURAKARE, ESTEBAN; GONZALEZ AUDINO P.

Congreso; 7th International Conference of Phthiraptera; 2023

Institute of Zoology, Guangdong Academy of Science

 Pediculushumanus capitis  De Geer is known as head louse, it belongs tothe family Pediculidae, order Phthiraptera. The head louse is a cosmopolitanhuman ectoparasite, it causes pediculosis and is one of the most prevalentparasitic diseases of humans. Lice have a clear attraction towards volatilecompounds from head odor and human scalp, as well as intraspecific attractionamong individuals of P. humanus capitis.Recent work from our lab supports that volatile active substances present inthe feces of head lice are connected with their aggregation behavior. Theseresults suggest the hypothesis that the associated mycobiota could produce thesevolatile compounds. The objective is to study the fungal community associatedwith P. humanus capitis. The first approach of this study involved the isolation of fungi fromthe cuticle and gut of live head lice. We collected lice fromchildren of scholar age, lice were transported in sterilized boxes and theywere examined under biosafety laminar flow. First, lice were inoculated insaline buffers (PBS) to extract fungi from cuticles, the lice guts were dissectedunder magnifying glass and inoculated in PBS. Both homogenates are transferredto Petri dishes containing Sabouraud culture media and incubated at 28 degreesand darkness per 7 days approximately. The strains were identified by evaluation of the macro morphologicalaspects of the colonies as well as by the micromorphological charactersobserved under a light microscope. Our results determined at least 15 differentmorphotypes, the strains most abundant were 5. A total of 348 strains wereextracted from cuticles and 599 from guts. The most abundant strain presents arelative frequency of 33% in cuticle and 23% in gut, and the second relativefrequency was 12% in cuticles and 18% in guts. These fungi are differentspecies of the genus Penicillium, Alternaria and Rhodotorula. These strainswill be submitted to comportamental analysis to examine the lice responsestowards the fungal volatile compounds. These results represent the firstanalysis of the fungi community of P.humanus capitis.