Sampling and analyzing microbial aerobiome on intensive livestock farms by using microbial traps in drones

Dispersal of particulates of organic materials carrying microorganisms is commong in presence of large livestock production. Particulate can be released directly from the animals but can also result from feeding, manure storage and other animal management. Microorganisms, mainly enterobacteria, can expose workers to potential health risks, such as particulate PM2.5 and gases of various origins such as ammonia. To prevent diseases due to infections, zoonoses and inflammatory states, it is therefore essential to monitor the dispersion of microorganisms present in the air in the open environment, both in internal areas and in areas adjacent to intensive farming. The aim of the study is to develop a system of microbial traps to be equipped on a drone to sample the microbial aerobiome surrounding farms. Traps for microorganisms were developed: agar plates and petrolatum-coates plates were designed and tested, inserted in a drone with aspiration capability of 1000 L in a few minutes. We developed a DNA extraction method that allowed to extract and amplify very low amount of bacterial DNA, adapting a high sensitivity extraction kit dedicated to viral nucleic acids combined with the use of a specific lysis buffer. In addition, microbial communities were also analyzed using Ecoplate Biolog, resulting in comparative phenomics from a urbanized and a rural area, possibly correlated to the level of pollutants of the two sites. In future we aim to sequence the metagenomes through Next Generation Sequencing, to study the phylogenetic and taxonomic relationships of the microbial aerobioma sourrounding large livestock facilities.