[Detection of Emericella nidulans from bedding materials in horse breeding environment and its significance as a causative agent of guttural pouch mycosis in horses].

The research article examined the prevalence of the fungus Emericella nidulans in horse bedding from various farms in Japan and its potential to cause guttural pouch mycosis in horses. Additionally, the study analysed growth conditions that could stimulate the proliferation of this fungus.

Sampling and Fungus Detection

• The research involved the collection of 66 samples of horse bedding materials from 33 different farms across Japan.
• The bedding materials included 60 samples of rice straw, 2 samples of wheat straw, 2 samples of timothy hay, and 2 samples of wood chips.
• The study focused on the detection and incidence rate of a fungus known as Emericella nidulans, which is also referred to as Aspergillus nidulans.
• Results indicated a high incidence rate of the fungus, found in about 75.8% of the collected bedding samples.
• The detection of the fungus was nearly as frequent in new bedding as it was in used samples, regardless of the type of bedding material.

Growth Conditions of E. nidulans

• The optimal moisture content for the growth of E. nidulans was determined to be Aw 0.94, achieved by adding water to sterilized rice straw cultures.
• Furthermore, the addition of a 0.3% urea solution to the sterilized rice straw cultures greatly enhanced the formation of conidial and ascocarp, which are elements of the fungus’s reproduction process.
• The study also confirmed the significant impact of urea, a component typically found in urine, in aiding the formation of conidial and ascocarp when used as the sole nitrogen source in a synthetic medium.

Significance of Findings

• The researchers suggest that the findings are important to understanding potential hazards of new bedding materials, particularly due to the possible severe contamination of E. nidulans.
• Given the optimal growth conditions for the fungus, it is indicates that its proliferation could readily occur within the stables, potentially aided by the presence of horse urine.
• This study is also significant in identifying a possible reservoir of E. nidulans, which is the causative agent of a fungal disease in horses known as guttural pouch mycosis.