The Detection And Spread Of Airborne Aerobic Bacteria And Staphylococcus Aureus In Cattle And Sheep Farms

The study observed a cattle farm and one sheep farm separately in Shanxi province,and collected air samples from the environment of those farms and their surroundings during four seasons respectively to analyze the variable change of the concentration of airborne aerobic bacteria and Staphylococcus isolated from the environment and explore the regular aerodynamics distribution pattern; Besides,this study took Staphylococcus Aureus as an indicator with drug resistance experiments and homology analysis using ERIC-PCR to explore the spreading of aerosol in animal houses and realize the aim of this study to evaluating the impact caused by airborne aerobic bacteria from animal houses on public health and animal health,thus providing scientific evidences for the environmental control and disinfection in farm.The study using 5% rams sheep blood agar medium as sampling medium detected the concentration of airborne aerobic bacteria and staphylococcus in cattle houses?playgrounds and outdoor environment(upwind 10m,away;downwind 10,50,100m,away),as long as sheep houses and outdoor air (upwind 10m away;downwind 10m,50m,100m away).An initial analysis of the relativity between indoor and outdoor airborne aerobic bacteria was conducterd in this study. The results shows:the concentration of airborne aerobic bacteria and staphylococcus from cattle farm are 0.21 ×103 CFU/m3?5.26×103 CFU/m3 and 0.16×103 CFU/m3?-4.13×103 CFU/m3 respectively,the highest concentration collected in winter while the lowest one got in spring,The airborne aerobic bacteria mainly distributed in stage-four and stage-five in six -stage Andersen samplers and can easily invade into human and livestock's small bronchus even alveolar. The concentration of airborne aerobic bacteria and staphylococcus from sheep farm are 0.37×103 CFU/m3?5.55×103 CFU/m3 and 0.22×103 CFU/m3?4.82×103 CFU/m3 respectively, the highest number got in summer and the lowest one in spring,the airborne aerobic bacteria mainly distributed in stage-one and stage-four in six-stage Andersen samplers and can easily inroad into human and livestock's small bronchus.Besides,the majority of the airborne aerobic bacteria are G+ coccus no matter in cattle or sheep house,and the concentration of airborne aerobic bacteria and staphylococcus in downwind air was reducing with the distance between sampling sites and animal houses increased.Using 16S rRNA molecular identification technology to identify 51 strains of S.aureus positive strains from 71 strains of suspected S.aureus in cattle farms.The drug sensitivity test results of S.aureus collected from cattle houses surroundings suggested that S.aureus isolated from indoor and outdoor air and fecal samples all have a severe broad-spectrum drug resistance;The homology analysis using ERIC-PCR shows that the infarm air-obtained have 19 S.aureus strains shares over 90% similarity with corresponding fecal-obtained strains, the outfarm downwind air-obtained 7 strains shares over 90% similarity with corresponding infarm air-obtained strains and fecal-obtained strains.Based on the results a conclusion can be drown that S.aureus isolated from cattle feces can form into microorganism aerosol and spread to the public surroundings and finally cause a pollution.