本文選題：沙門菌 + 種雞場��； 參考：《揚州大學(xué)》2017年碩士論文

【摘要】：沙門菌病(Salmonellosis)是指由沙門菌屬(Salmonella)細菌所引起的各種動物及人的疾病的總稱,是世界動物衛(wèi)生組織法定報告的動物疾病,是我國政府規(guī)定的二類動物疫病,是《國家中長期動物疫病防治規(guī)劃(2012-2020年)》確定的優(yōu)先防治的病種。沙門菌感染的畜禽及其被污染的產(chǎn)品是食源性沙門菌的重要來源之一,這不僅阻礙了畜禽相關(guān)產(chǎn)業(yè)的發(fā)展,而且也對人類健康構(gòu)成了巨大威脅。種雞養(yǎng)殖是養(yǎng)雞業(yè)上游的生產(chǎn)環(huán)節(jié),減少這一環(huán)節(jié)雞群中沙門菌的感染能夠有效降低其后代次雞群及其相關(guān)產(chǎn)品的沙門菌檢出比例。許多發(fā)達國家在種雞群中采取的檢疫淘汰制度有效控制甚至消滅了雞白痢、雞傷寒沙門菌在雞群中的傳播;近年來這些國家的沙門菌流行病學(xué)調(diào)查結(jié)果顯示雞群中副傷寒沙門菌如腸炎沙門菌、鼠傷寒沙門菌、肯塔基沙門菌等開始成為優(yōu)勢血清型。目前針對我國種雞場雞群中沙門菌感染情況的研究還不是很多,種雞養(yǎng)殖過程中不同階段的沙門菌流行規(guī)律、防控關(guān)鍵點還不是完全清晰。本研究以國內(nèi)不同地區(qū)的7家種雞場為研究對象,調(diào)查了種雞養(yǎng)殖場中沙門菌的流行狀況、血清型分布及藥物敏感性特點,并以其中一個規(guī)�；N雞場作為場內(nèi)流行規(guī)律調(diào)查分析的樣板,分階段分析流行狀況,綜合應(yīng)用CRISPR、PFGE分子分型技術(shù)分析不同沙門菌分離株之間的內(nèi)在聯(lián)系,期望探明國內(nèi)種雞場沙門菌的流行現(xiàn)狀及傳播特點,摸清種雞養(yǎng)殖過程中的防控關(guān)鍵點,為種雞場沙門菌的科學(xué)有效防控提供依據(jù)。一、種雞場沙門菌的分離鑒定及耐藥性分析在2015年6月至2017年3月期間,對A、B、C、D、E、F、G共7家種雞場進沙門菌的分離鑒定,共采集樣品2,185份,分離沙門菌326株,總體分離率為14.92%。統(tǒng)計學(xué)分析表明,不同種雞場沙門菌分離率存在差異(P0.05),分離率最高可達18.37%,最低的一家種雞場則尚未分離到沙門菌。針對F種雞場不同養(yǎng)殖階段沙門菌分離率的調(diào)查研究表明,產(chǎn)蛋期和孵化期的沙門菌分離率較高,分別達到24.66%和24.52%;而引種階段的分離率則相對較低,為6.67%。統(tǒng)計分析表明,在種雞養(yǎng)殖的各個階段中,引種階段、育雛期、產(chǎn)蛋期沙門菌分離率逐漸上升;產(chǎn)蛋期和孵化期的沙門菌分離率維持在較高水平;孵化期到孵化后期沙門菌分離率有所下降。7家種雞場分離的沙門菌血清型鑒定結(jié)果顯示,腸炎沙門菌是優(yōu)勢血清型,其次是雞-雛沙門菌,而其他血清型分布比例則相對較小。研究對A、B、F、G四家種雞場分離的223株沙門菌進行了 16種抗菌素藥物敏感性試驗,整體情況顯示,萘啶酸耐藥比例最高,達94.62%;其次是氨芐西林,耐藥率為56.05%;鏈霉素的耐藥率也相對較高,為39.91%。多重耐藥統(tǒng)計結(jié)果顯示,細菌耐藥種類在1-3種的比例最高,達76.23%;耐藥種類在4-6種之間的比例為17.94%;7種及以上的比例相對較低。分析F種雞場中沙門菌的耐藥情況,細菌同樣對萘啶酸表現(xiàn)出很高的耐藥率,達91.30%;分析不同養(yǎng)殖階段沙門菌的多重耐藥分布情況,產(chǎn)蛋期分離細菌的多重耐藥種類明顯增多,并且16種測定藥物中有11種藥物都在產(chǎn)蛋期時耐藥率最高。二、不同分子分型技術(shù)在種雞場沙門菌傳播規(guī)律及溯源研究上的應(yīng)用本研究首先對F種雞場不同養(yǎng)殖階段分離的115株腸炎沙門菌進行了 CRISPR分型,結(jié)果顯示所有的腸炎沙門菌被分類成了 3種CRISPR型,這表明F種雞場內(nèi)存在有基因型不同的多種腸炎沙門菌克隆亞群。此外,研究還發(fā)現(xiàn)同種CRISPR型的腸炎沙門菌往往來自于多個分離階段,這表明種雞場中可能存在沙門菌的交叉?zhèn)鞑�。引種階段分離的SET1型和SET2型腸炎沙門菌,同樣能在其后的養(yǎng)殖階段中被發(fā)現(xiàn),說明引種階段的沙門菌傳播至其后的養(yǎng)殖階段,提示引種階段可能是沙門菌防控的一個關(guān)鍵環(huán)節(jié)。CRISPR型和耐藥表型的聯(lián)合分析顯示,同一 CRISPR型的細菌耐藥譜往往完全或部分相似;耐藥種類和CRISPR型的對應(yīng)統(tǒng)計結(jié)果還顯示SET2和SET3型的細菌耐藥譜數(shù)目都較為相似。這些結(jié)果提示,CRISPR分型技術(shù)可能在單一血清型分子亞分型中提供了較好的亞類區(qū)分。對存在供貨關(guān)系的G和F兩家種雞場的60株腸炎沙門菌進行PFGE分型,PFGE聚類分析共分成了 4個聚類簇,其中PFGE聚類簇A既包含17株G種雞場來源的腸炎沙門菌,還有32株則來源于F種雞場。這一結(jié)果提示,供需鏈間種苗雞的引入是F種雞場沙門菌傳播來源的途徑之一。同時,研究還發(fā)現(xiàn)除PFGE聚類簇A外,細菌還分成了幾類細菌數(shù)目相對較少的PFGE聚類簇B、C和D,分析每個聚類簇中細菌的來源,發(fā)現(xiàn)PFGE聚類簇C的細菌都來源于F種雞場,PFGE聚類簇B和D則都屬于G種雞場,這些結(jié)果說明供需鏈間沙門菌的傳播感染還存在其他途徑,不同沙門菌亞型在雞場中的傳播能力可能存在差異。
[Abstract]:Salmonellosis (Salmonellosis) refers to the general name of all kinds of animals and human diseases caused by Salmonella bacteria. It is an animal disease reported by the world animal health organization. It is the two kind of animal disease stipulated by the government of our country. It is the priority prevention and control disease in the plan of prevention and control of the middle and long term animal epidemic disease (2012-2020 years). Salmonella infected livestock and poultry and their contaminated products are one of the important sources of food borne Salmonella, which not only hinders the development of livestock and poultry industry, but also poses a great threat to human health. The breeding of chicken is a production link in the upstream of the chicken breeding industry. Reducing the infection of Salmonella in this ring chicken group can effectively reduce its infection. The detection ratio of Salmonella in the offspring of descendants and their related products. The quarantine and elimination system adopted by many developed countries effectively control and even eliminate the spread of chicken white dysentery and Salmonella typhimurium in the chickens. In recent years, the epidemiological investigation of Salmonella in these countries shows that the paratyphoid salmonella in the chicken group, such as enteritis sand, has been shown. Bacteria, Salmonella typhimurium, Salmonella, Kentucky, and Salmonella became dominant serotypes. At present, there are not many studies on the infection of Salmonella in chicken farms in China. The epidemic law of Salmonella in different stages of chicken breeding and the key point of prevention and control are not completely clear. This study is based on 7 domestic chicken farms in different regions of China. In this study, the epidemic situation of Salmonella, serotype distribution and drug sensitivity in the breeding farm were investigated, and one of the large-scale chicken farms was used as a sample for the investigation and analysis of the field epidemic. The epidemic situation was analyzed in stages, and the CRISPR and PFGE molecular typing techniques were used to analyze the different Salmonella isolates. In order to find out the epidemic situation and transmission characteristics of Salmonella in domestic chicken farm, we can find out the key points of prevention and control in the breeding process of the chicken, and provide the basis for the scientific and effective prevention and control of Salmonella in the chicken farm. First, the isolation and identification of Salmonella in the chicken farm and the analysis of drug resistance from June 2015 to March 2017, 7 species of A, B, C, D, E, F, G The isolation and identification of Salmonella in the chicken farm, 2185 samples were collected and 326 strains of Salmonella were isolated. The total separation rate was 14.92%. statistical analysis showed that the isolation rate of Salmonella in different kinds of chicken farms was different (P0.05), the highest separation rate was up to 18.37%, and the lowest one was still not isolated from Salmonella. The isolation rate of Salmonella strains showed that the isolation rate of Salmonella was higher in laying and hatching period, reaching 24.66% and 24.52% respectively, while the separation rate of the introduction stage was relatively low. The 6.67%. statistical analysis showed that the separation rate of Salmonella in the introduction stage, brooding stage and laying period was gradually rising in each stage of breeding, laying period and incubation period. The isolation rate of Salmonella in the period of incubation was maintained at a high level, and the isolation rate of Salmonella from the incubation period to the later stage of the hatchery decreased. The serotype identification of Salmonella isolated from the.7 poultry farm showed that Salmonella enteritis was the dominant serotype, followed by the chicken chick Salmonella, and the other serotype distribution ratio was relatively small. The study on four chickens with A, B, F and G was a study. 223 strains of field isolated Salmonella were tested with 16 antimicrobial susceptibility tests. The overall situation showed that the drug resistance rate was the highest, up to 94.62%, followed by ampicillin, the drug resistance rate was 56.05%, and the drug resistance rate of streptomycin was relatively high. The statistical results of 39.91%. multiple resistance showed that the rate of bacterial resistance in the 1-3 species was the highest, up to 76.2. 3%, the proportion of the resistant species in the 4-6 species was 17.94%, and the proportion of the 7 species was relatively low. The resistance of Salmonella in the F chicken farms was analyzed, and the bacteria also showed a high drug resistance rate to nnidium acid, up to 91.30%. The multi drug resistance distribution of Salmonella in different breeding stages was analyzed, and the multidrug resistance of the isolated bacteria in the laying period was obvious. In addition, the drug resistance rate of 11 of the 16 kinds of drugs at the laying period was the highest. Two, the application of different molecular typing techniques to the propagation and traceability of Salmonella in the chicken farm was applied to the CRISPR classification of Salmonella enteritis isolated at different breeding stages in F chicken farms. The bacteria were classified into 3 CRISPR types, which indicated that there were different genotypes of the clone subgroups of Salmonella enteritis in F chicken farms. In addition, the study also found that the same CRISPR type of Salmonella enteritis was often derived from multiple separation stages, which indicated that the cross transmission of Salmonella may exist in the chicken farm. SET1 and SE in the introduction stage were isolated. The Salmonella enteritis type T2 can also be found in the subsequent breeding stage, indicating the spread of Salmonella in the introduction stage to the subsequent breeding stage, suggesting that the introduction stage may be a key link in the prevention and control of Salmonella. The joint analysis of the.CRISPR type and drug resistant phenotype shows that the same CRISPR type of bacterial resistance spectrum is often completely or partially similar. The corresponding statistical results of resistance species and type CRISPR showed that the number of SET2 and SET3 type bacterial resistance profiles were similar. These results suggest that CRISPR typing may provide better subclass differentiation in single serotype subtypes. PFGE points for 60 strains of Salmonella enteritis in G and F two chicken farms with supply relations. The PFGE cluster analysis was divided into 4 cluster clusters, in which the PFGE cluster A contained not only 17 strains of Salmonella enteritis from G chicken farms, but also 32 from F chicken farms. The results suggested that the introduction of the interseed and supply chain of the supply chain is one of the ways for the transmission of Salmonella in F chicken farms. Meanwhile, the study also found that the bacteria except the PFGE cluster A, the bacteria were also found to be bacteria. PFGE cluster B, C and D were also divided into several kinds of cluster clusters, C and D were used to analyze the origin of bacteria in each cluster. It was found that all the bacteria of PFGE cluster C were derived from F chicken farms, PFGE cluster B and D were all G seed farms. These results showed that the transmission infection of Salmonella among the supply chains still existed other ways, different Salmonella subtypes were in the field. There may be a difference in the ability of the chicken farm to spread.
【學(xué)位授予單位】：揚州大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：S858.31

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本文編號：1935305