Induction of systemic zygomycosis in pregnant mice by Absidia corymbifera

Area of Science:

• Mycology
• Immunology
• Veterinary Pathology

Background:

• Absidia corymbifera is a fungus known to cause opportunistic infections.
• Pregnancy can alter immune responses, potentially increasing susceptibility to fungal infections.
• Understanding fungal pathogenesis during gestation is crucial for maternal and fetal health.

Purpose of the Study:

• To investigate the effects of Absidia corymbifera inoculation on pregnant BALB/c mice.
• To determine the relationship between spore dosage, gestational timing, and the development of mycotic placentitis.
• To assess the distribution of Absidia corymbifera within maternal and fetal tissues.

Main Methods:

• Intravenous inoculation of pregnant BALB/c mice with varying doses of Absidia corymbifera spores (10^3 to 10^5).
• Challenges were administered on different days of gestation (days 10, 12, and 14).
• Placental and extrauterine organ tissues were examined for evidence of fungal infection.

Main Results:

• Mycotic placentitis was observed when 10^4 or more Absidia corymbifera spores were inoculated.
• Challenges on days 12 and 14 of pregnancy resulted in significantly higher rates of placental infection compared to day 10.
• Increasing spore dosage from 10^4 to 10^5 significantly elevated placentitis incidence (e.g., from 6.7% to 15.2% on day 14).
• Absidia corymbifera showed no specific affinity for placental tissues, with frequent infections also noted in extrauterine organs.

Conclusions:

• Intravenous inoculation with Absidia corymbifera can induce mycotic placentitis in pregnant mice.
• The risk and severity of placentitis are dose-dependent and influenced by the timing of fungal exposure during gestation.
• Absidia corymbifera dissemination is not restricted to the placenta, indicating a potential for systemic infection in the dam.