An entomopathogenic fungus exploits its host humoral antibacterial immunity to minimize bacterial competition in the hemolymph.

BACKGROUND: The insect hemolymph (blood-equivalent fluid), composed of a large number of hemocytes (blood cells) and a variety of soluble immune effectors, is hostile for pathogens including fungi. In order to survive in the insect hemocoel (body cavity), the entomopathogenic fungus (EPF) has evolved two classical coping strategies, namely evasion and suppression of the host immune reactions. However, it remains unclear whether EPF has other ways of coping with host immunity. RESULTS: In this study, we demonstrated that Metarhizium rileyi (an EPF) infection by injection of blastospores into the hemocoel enhanced the plasma antibacterial activity of cotton bollworm (Helicoverpa armigera), which was partially due to the enhanced expression of antimicrobial peptides (AMPs). The early stage of M. rileyi infection induced the translocation of gut bacteria into the hemocoel, where they were subsequently cleared due to the enhanced plasma antibacterial activity. Further, we showed that the enhanced plasma antibacterial activity and AMP expression were attributable to M. rileyi but not the invasive gut bacteria (opportunistic bacteria). Elevated ecdysone (major steroid hormone in insects) levels in the hemolymph at 48 h post-M. rileyi infection might contribute to the enhanced expression of AMPs. The fungus-elicited AMPs, such as cecropin 3 or lebocin, exhibited potent inhibitory activity against the opportunistic bacteria but not against hyphal bodies. In addition, the opportunistic bacteria competed with hyphal bodies for amino acid nutrients. CONCLUSIONS: M. rileyi infection induced the translocation of gut bacteria, and then the fungi activated and exploited its host humoral antibacterial immunity to eliminate opportunistic bacteria, preventing them from competing for nutrients in the hemolymph. Unlike the classical strategies, EPF utilizes to evade or suppress host immunity, our findings reveal a novel strategy of interaction between EPF and host immunity. Video Abstract.

The Energy Density and Treatment Times Are the Main Factors That Affect the Efficacy of Long-Pulsed 1,064-nm Nd:YAG Laser Treatment for Onychomycosis Caused by Trichophyton rubrum.

BACKGROUND: No optimal regimen exists for the LPNYL (long-pulsed 1,064-nm neodymium:yttrium-aluminum-garnet laser) for treating onychomycosis. OBJECTIVE: To establish an optimal LPNYL treatment regimen for onychomycosis caused by Trichophyton rubrum (OCTr). PATIENTS AND METHODS: First, 511 infected nails of 177 patients were treated using LPNYL with orthogonally designed regimens according to various energy densities, spot sizes, pulse widths, and treatment times. The optimal treatment regimen was established by multivariate analysis. Next, 69 patients with 221 infected nails were randomized to receive oral itraconazole (drug group) and the optimal regimen of LPNYL treatment (laser group). The clinical efficacy (CE) and mycological efficacy (ME) were evaluated at 6 and 12 months following the start of treatment, and adverse reactions were recorded in both groups. RESULTS: Both CE and ME were significantly correlated with the energy density (p < 0.05) and treatment times (p < 0.05), but not with the spot size (0.071 < p < 0.083) or pulse width (0.051 < p < 0.060), at 6 or 12 months. There were no significant differences at 6 or 12 months (p > 0.05), and no significant difference was observed in CE at 12 months between the two groups (p > 0.05). At 6 months, the CE in the laser group was significantly higher than that in the drug group (p < 0.001). CONCLUSIONS: LPNYL is effective and safe for treating OCTr. The energy density and treatment times are the main factors that affect the efficacy. The optimal regimen for LPNYL is an energy density of 45 J/cm2, pulse width of 35 ms, spot size of 4 mm, frequency of 1 Hz, and 6 treatments with 1-week intervals. Laser treatment has rapid clinical recovery.