Technical note: concentration and composition of airborne aerobic bacteria inside an enclosed rabbit shed

Abstract

Numerous studies have been conducted to analyse bacterial aerosols in animal houses, which is beneficial for the control of animal diseases. However, little information on aerosols in enclosed rabbit sheds was available. An FA-1 sampler was employed to collect air samples in an enclosed rabbit house in the Qingdao region of China. Concentration, composition, and aerodynamics of bacterial aerosols inside the enclosed rabbit shed were systematically analysed. The concentration of airborne bacteria inside the rabbit shed was 2.11-6.36×10 4 colony forming unit/m 3 (CFU/m 3 ). Seventeen species of bacteria belonging to eight genera were identified. Among these, there were 11 species belonging to 4 genera of gram-positive bacteria, and 6 species belonging to 4 genera of gram-negative bacteria. The dominant species of bacteria were, in descending order, Micrococcus luteus (49.4%), Staphylococcus epidermidis (25.5%), and Alcaligenes odorans (10.2%). A total of about 76.3% of airborne bacteria was distributed in stages C-F of the FA-1 sampler (that ranges from A to F), with aerodynamic radii <3.3 µm in diameter. These particulates could enter lower respiratory tracks and even alveoli, posing a potential threat to the health of both animals and breeders.

Comparison of floor bacterial load in different types of rabbit cages

“…The higher microbial count in Area 3 may be due to the accumulation of faecal matter and the presence of moisture which favours the multiplication of bacteria at a faster growth. This is in agreement with Li et al, (2016) who showed that a large number of airborne aerobic bacteria were present inside the enclosed rabbit shed and the type of environment may pose a serious threat to the health of exposed animals and individuals. This is in agreement with the findings of Gautam et al, (2011) who mentioned that the slower water replacement and available standing water leads to a greater pathogen load.…”