Microsporum canis is a common zoophilic dermatophyte, which causes a range of infections. To explore the pathogenic mechanism of tinea capitis, we used the suppression subtractive hybridization (SSH) technique to investigate the differences in gene expression between different cultures of Microsporum canis incubated on three different types of mineral media containing child glabrous skin, child scalp tissue and adult scalp tissue. Using dot-blot hybridization and real-time PCR technique, we successfully screened and identified a pair of genes that had expression levels 44.6 and 117 times higher in culture 1 (M. canis cultured in mineral medium with child scalp tissue) than in culture 2 (M. canis cultured in mineral medium with glabrous skin tissue), and another pair of genes with expression levels 78.2 and 9.8 times higher in culture 1 than in culture 3 (M. canis cultured in mineral medium with adult scalp tissue). These four genes were found to have 41%, 53%, 40% and 94% homology to those encoding a hypothetical protein [family of serine hydrolases 1; (FSH1)], PQ loop repeat protein (PQ-LRP), a predicted protein [porphyrin galactose 4; (P-GAL4)] and NADH dehydrogenase subunit (NADH)1, respectively. The upregulation of the FSH1, PQ-LRP, P-GAL4 and NADH1 genes in cultures of child scalp tissue indicates that they are essential in the pathogenesis of tinea capitis caused by M. canis.

IntroductionBeauveria spp. and Dastarcus helophoroides Fairmaire adults were simultaneously released to attack elder larvae or pupae of Monochamus alternatus in pine forests in China. However, little is known about the pathogenicity virulence and biosafety of Beauveria spp. on beneficial adults of D. helophoroides, and specific Beauveria bassiana (Bb) strains should be selected for synthetic release together with D. helophoroides.MethodsA total of 17 strains of Beauveria spp. were collected, isolated, and purified, and then their mortality, cadaver rate, LT50, spore production, spore germination rate, and growth rate of D. helophoroide adults were calculated based on 0–20 days data after spore suspension and powder contact.Results and discussionThe lethality rate of BbMQ, BbFD, and BbMH-03 strains to D. helophoroides exceeded 50%, and the cadaver rate reached 70.6%, among which the mortality rate (82.22%), cadaver rate (47.78%), spore production (1.32 × 109 spores/ml), spore germination rate (94.71%), colony dimension (49.15 mm2), and LT50 (10.62 d) of the BbMQ strain were significantly higher than those of other strains (P < 0.01), and the mortality of D. helophoroides adults increased significantly with increased spore suspension concentration, with the highest mortality reaching 92.22%. This strain was identified as Beauveria bassiana by morphological and molecular methods, while the BbWYS strain had a minimum lethality of only 5.56%, which was safer compared to other strains of adult D. helophoroide. Consequently, the biological characteristics and pathogenicity of different Beauveria bassiana strains varied significantly in their effects on D. helophoroide adults, and the safety of different strains should be assessed when they are released or sprayed to control multiple pests in the forest. The BbMQ strain should not be simultaneously sprayed with releasing D. helophoroide adults in the same forest, while the BbWYS strain can be used in concert with D. helophoroide to synergize their effect.