| The farms has produced and disseminated fungal aerosol to the surrounding environment all the time,it can cause a variety of diseases,and fungal toxin poisoning or induce other diseases,poses a great threat to the livestock breeding.In order to investigate the fungal aerosol distribution characteristics in sheep farms in different regions of Shanxi Province,and monitor the toxigenic fungi and toxin of the feeding sheep farms aerosol,dressing by screening effective disinfectants which can killing of environmental fungi effective,and provide a theoretical basis for control feeding sheep farms environment and prevention disease;Application of Andersen-6 air biological sampler with Rose Bengal medium and chloramphenicol as the medium,to collect the samples from 9 semi closed sheep houses and the airborne fungi concentration,composition and particlesize distribution differences of south,north,and the middle part of of Shanxi province were determined;We analyzed the diversity of airborne fungal which were collected by AGI-30 and forage and dung DNA by ERIC-PCR;Detected the toxin producing key emetic toxin gene for aflatoxins,trichothecenes,zearalenone toxin in Aspergillus and potentially toxigenic Fusarium from the aerosol;Aspergillus niger,Penicillium and Candida albicans were as indicator fungi to carry out killing fungi test with peracetic acid and glutaraldehyde compound disinfectant、bromogeramine liquid、Decamethylammonium bromide,povidone iodine and peracetic acid,and applicated the compound disinfectant of glutaraldehyde and peracetic acid carryed out disinfection test to sheep house.The results show that:(1)The ambient airborne fungal concentration increased as the latitude lowered,and the in-house concentrations were 2.1～9.4 times higher than those of ambient airborne fungi,but there was no significant correlation with latitude(P>0.05).The size distribution of airborne fungal particlesmainly centralized in gradeⅢ～grade V(1.1～4.7μm),accounted for 61.3%～88.9%of the colonies,and increased as the latitude decreased.Peak values occurred atgrade IV(2.1～3.3μm);Human and animal will inhalation 5.1～20.4 CFU to deep respiratory tract per minute,higher in winter than in summer.The value of count medium diamter(CMD)decreased with the lowered latitude.(2)The airborne fungi showed obvious polymorphism in different regions of Shanxi Province sheep farms,25 fungal genera were isolated and identified,common dominant fungi genera were Penicillium spp,Aspergillus spp,Alternaria spp,and Saccharomycetes spp,the airborne fungi what from same area feeding sheep farms were defferent in composition of summer or winter.The results of ERIC-PCR suggested that the bigger the Shannon-weiner index of airborne fungi in and outside the sheep houses,the lower the latitude.The Simpson’s diversity index decreased with the lowered latitude,but the condition in the forage was opposite.The airborne fungi inside the sheep houses exhibited the highest similarity with dung and dirt.(3)There are 60 Aspergillus and 7 Fusarium species were isolated from airborne fungi of sheep house.The positive rate of the key genes of Aspergillus was 21.6%,and positive rate of the key genes of Fusarium was 17.6%.(4)The effect of the peroxy acetic acid glutaraldehyde compound disinfectant was better than Benzalkonium Bromide、Gui Jiaxiu ammonium,povidone iodine and peracetic acid in recommended dosage.Peracetic acid and glutaraldehyde compound disinfectant with 1:256 dilution,20ml/m3 carryed out the spray disinfection,after 30 min the fungal killing rates were ground(89.3%)and wall(72.3%),cage(88.7%),and after 6 hours it achieved the best results to airborne fungi in the sheep house(the killing rate was 47.8-68.1%),can maintain more than 24 hours.In summary,this study analyzed the spatio-temporal distribution characteristics of fungal aerosols in sheep farms in different regions of Shanxi Province.The differences in bacterial composition,and monitored the potential distribution of airborne toxin-producing strains and their toxins in sheep farms,and a highly effective disinfectant capable of effectively killing the fungi of the sheep house was provided,which provided a theoretical basis for environmental control and prevention and control the disease in the sheep farms. |
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