H5 subtype highly pathogenic avian influenza(H5-HPAI)is one of the category I animal diseases that seriously endangers poultry industry and public health,and is also one of the zoonotic diseases highly concerned and controlled in China.At present,common molecular biological techniques include reverse transcription-polymerase chain reaction(RT-PCR),real-time quantitative PCR(RT-qPCR),reverse transcription-recombinase-aided amplification(RT-RAA),RT-RAA with lateral flow dipstick(RT-RAA-LFD),RT-RAA clustered regularly interspaced short palindromic repeat and their associated proteins combined with lateral flow chromatography test strips(RT-RAA-CRISPR Cas13a-LFD),etc.In order to compare the sensitivity difference of different assays for H5-AIV,the prepared cRNA standards were diluted and detected by RT-PCR,RT-qPCR,RT-RAA,RT-RAA-LFD and RT-RAA-CRISPR Cas13a-LFD,respectively.The results revealed that the sensitivity of RT-PCR,RT-qPCR,RT-RAA,RT-RAA-LFD and RT-RAA-CRISPR Cas13a were 102,10-1,100,100,and 10-1 copies/μL,respectively.RT-PCR,RT-RAA,RT-RAA-LFD,RT-RAA-CRISPR Cas13a-LFD were highly compliant in detection of clinical samples when compared with RT-qPCR,which were 85.00%,93.75%,88.75%and 91.25%,respectively.In conclusion,the five methods could detect H5-AIV with a high detection rate,but RT-qPCR and RT-RAA-CRISPR Cas13a-LFD were more sensitive and suitable for clinical test in laboratories and grassroots farms,respectively.The application effectiveness of different detection methods for H5-AIV were evaluated in the study,providing a reference for selecting an accurate and reliable method under different conditions,and a technical support for future prevention and control of H5-AIV infection.
On May 1,2021,a notification was received by Mianyang Center for Animal Disease Prevention and Control from Nanchong Center for Animal Disease Prevention and Control,noting that a patient infected with Brucella in Nanchong sold his goats to a villager in Fuyi Township,Yanting County,Mianyang City.In order to timely evaluate the risk of disease introduction and transmission,and to safeguard public health safety,an emergency epidemiological investigation among livestock was conducted by the staff from animal disease prevention and control centers in Mianyang City and Yanting County by means of on-site visit,interview and laboratory test.It was found that the positive rate of the farm was 43.75%,and the outbreak was mainly caused by the goats at risk level that were purchased from other regions,and spread through nannygoats receiving mating outside.Against which,it was recommended to intensify monitoring over brucellosis,strengthen quarantine and transportation supervision,improve the construction of grassroots veterinary system,and to increase the publicity of knowledge about brucellosis prevention and control.
With the development of internet technology,live commerce and e-commerce platforms,with good conversion rates of online sales and marketing effects,have become major hotspots in the online shopping industry.The traditional meat marketing,from slaughterhouses to distributors,and then to the public consumers,is far away from the need of social development.However,the online marketing of animals and animal products are still in a vacuum zone without any supervision.In the paper,based on the investigation and publishment of a case selling animal products without quarantine via internet live broadcast,the benefits and drawbacks of such marketing were analyzed,and the illegal facts of the persons involved were also analyzed in combination with the existing laws and regulations concerning animal disease prevention and food safety in China,then aiming at the standardized management for online marketing of animals and animal products,some suggestions were proposed,with a view to providing a reference for future investigation of similar cases,improving the legal awareness of units(individuals)who engaged in production and operation within the existing legal framework,and creating a good atmosphere for lawful operation.
In order to investigate the infection status of canine Echinococcus granulosus prevalent in Sichuan Province,and to evaluate the effectiveness of prevention and control measures,from 2019 to 2022,dog feces were collected from 35 epidemic counties for detection of Echinococcus granulosus by antigen sandwich ELISA kit.The results revealed that the average annual infection rates were 3.06%(159/5 200),2.11%(123/5 826),1.33%(83/6 227)and 1.12%(67/5 968)respectively in the four consecutive years,with statistical significance(P＜0.05).The average annual infection rates were 1.30%(166/12 673),3.09%(205/6 627),1.48%(35/2 367)and 1.78%(26/1 464)respectively in Ganzi Prefecture,Aba Prefecture,Liangshan Prefecture and Ya'an City,especially higher in Aba Prefecture(P＜0.05).In conclusion,the infection of canine Echinococcus granulosus was generally weakening in the province,but still relatively severe in the grassland pastoral areas of western Sichuan Plateau,posing a great threat to local livestock and human.For the purpose of ensuring human health and safety as well as healthy development of livestock industry,it was recommended to further strengthen the control of such infection from its source through deworming for dogs and bio-safety treatment of dog feces.
In order to establish a rapid,sensitive and specific method for detecting alpha toxin of Clostridium perfringens using Taq Man fluorescence quantitative PCR assay,based on common biological characteristics of all types of Clostridium perfringens,a pair of primers and a probe were designed with using the gene sequence encoding alpha toxin as the target sequence.A,B,C and D types of Clostridium perfringens DNA were used as templates to establish a TaqMan fluorescence quantitative PCR assay through optimizing the concentration of primers and probes and amplification conditions,meanwhile,its specificity,sensitivity and repeatability were evaluated.The results revealed that the Ct value was the lowest when the concentration of primers and probe were all 0.25 μmol/L;the method had good specificity without any cross-reaction with Escherichia coli,Pasteurella and salmonella;and good sensitivity with the minimum detection limit of 9.1 pg/μL for genomic DNA of Clostridium perfringens type A;and good repeatability with standard deviations of less than 0.4 for both intra group and inter group experiments;it was found that,after detection of 24 clinical samples collected in 2023,the positive detection rate of the established method(20.83%)was consistent with that of commercial reagent kits.In conclusion,a rapid,sensitive,stable and highly specific TaqMan fluorescence quantitative PCR assay was well established in the study,which could be used to quickly detect Clostridium perfringens alpha toxin,providing a powerful technical support for the prevention and control of Clostridium perfringens disease.
