皖西地区仔猪源致病性大肠杆菌分离鉴定与血清学分析

为探明当前皖西地区规模化猪场大肠杆菌病的病原及流行菌株血清型,本研究对该地区的12个规模化猪场典型病例进行了病原分离和血清型鉴定,报告如下.     

徐州地区猪源致病性大肠杆菌耐药性调查

为了掌握徐州地区猪场大肠杆菌耐药菌株的产生情况和耐药程度,在2016-2018两年间对徐州地区猪源大肠杆菌进行耐药监测。从猪场分离鉴定致病性大肠杆菌,采用纸片扩散法测定46株分离菌株对15种抗菌药物的敏感性。结果表明,猪源大肠杆菌分离株多重耐药现象严重,至少耐药10种以上,其中10耐和11耐的菌株所占比例最大,分别为28.3%和23.9%;分离菌株对阿莫西林、氟苯尼考、强力霉素耐药率最高,达到80%以上,对头孢噻呋耐药率最低,为17.4%。两年间痢菌净耐药率下降幅度最大,丁胺卡那霉素耐药率增长幅度最大。     

仔猪大肠杆菌病病原分离鉴定及药敏试验

从广东某猪场严重腹泻的仔猪中采集12份仔猪黄痢、白痢粪便样品,共分离出6株大肠杆菌.药敏试验结果表明,所分离到的6株大肠杆菌对头孢噻肟、头孢拉啶、诺氟沙星等药物最敏感,可作为防治该猪场仔猪大肠杆菌病的首选药物.利用所分离菌株研制出灭活铝胶菌苗注射产前母猪,其后代仔猪的黄、白痢发病率大大降低.     

某规模化猪场大肠杆菌的耐药性情况分析

为了调查猪场大肠杆菌的耐药性,从某工业化猪场分离到17份拉稀仔猪粪便样本进行大肠杆菌的分离和纯化鉴定,按NCCLS推荐的K-B法对67株大肠杆菌进行了17种抗生素敏感性试验,发现分离菌株对这17种药物有不同程度的耐药性,常用药物如四环素、复方新诺明等大部分抗菌药耐药性很高。     

猪大肠杆菌地方菌株的分离与耐药性监测

对某猪场腹泻仔猪和妊娠母猪进行了大肠杆菌的分离和鉴定,分离出15株猪大肠杆菌,其中3株为致病性大肠杆菌。耐药性监测结果表明,分离的菌株对氨苄青霉素、青霉素有明显耐药性,而对丁胺卡那霉素、妥布霉素、头孢哌酮较敏感。     

规模化猪场仔猪黄,白痢的防治研究

本研究采用麦康凯、 Ｅ Ｍ Ｂ 选择性培养基对四川绵阳、乐山、南充、温江、自贡、广汉、德阳等地规模化猪场仔猪黄、白痢黄型病例进行了大肠杆菌分离培养, 对分离株进行了详细的生化鉴定, 并用小鼠作致病性试验, 获得８８ 株致病性大肠杆菌。对８８ 株大肠杆菌中的１９ 株用１０ 种抗生素进行了药敏试验, 结果表明： 分离菌株对恩诺沙星、环丙沙星、庆大霉素较敏感, 而对多种常用抗生素产生了不同程度的耐药性。对四川９ 个规模化猪场进行了本场菌株大肠杆菌灭活苗免疫试验, 取得良好效果。根据本研究结果提出： 采用本场菌株灭活苗免疫, 结合使用少量敏感抗生素, 并配合加强饲养管理等综合措施是防治规模化猪场仔猪黄、白痢最为经济有效的方法。     

K_(88)~+肠病原性大肠杆菌在我国仔猪黄痢发病中的作用

本文研究了从江苏、上海、北京八个县十七个猪场新生仔猪腹泻分离到的大肠杆菌的抗原结构和肠道病原性,从其中十四个猪场分离到K_(88)~+肠道病原性大肠杆菌。在这十四个猪场,从40窝67头腹泻仔猪得到212个大肠杆菌分离物,其中来自26窝41头病猪的146个(68.9％)大肠杆菌分离物是具有K_(88)抗原的,它们的代表菌株在仔猪结扎肠试验中均表现肠道病原性。随猪场不同,这146个K_(88)~+分离物分属于6个O抗原型(O_(60)、O_(149)、O_(157)、O_9和一个未定型)。其中,以O_(60)在江苏、上海为最常见,这是一个国外未见报道的含K_(88)抗原的大肠杆菌的O抗原型。调查还发现了一种非大肠杆菌性的新生仔猪腹泻。为此,本文还对“仔猪黄痢”“新生仔猪腹泻”的定义问题进行了讨论。     

河南省猪源大肠杆菌的分离鉴定与耐药性分析

为了掌握河南省猪源大肠杆菌的耐药性情况,从规模化猪场抽取样品240份,通过细菌的分离、纯化,采用BD PhoenixTM-100全自动微生物鉴定系统对分离的大肠杆菌进行鉴定,并通过微量肉汤稀释法对分离菌株进行药物敏感性分析。结果显示:共分离菌株171株,分离率为71.3%;分离菌株对四环素、磺胺异恶唑、复方新诺明、强力霉素、氨苄西林、氟苯尼考耐药严重,耐药率均在80%以上。表明河南省猪源大肠杆菌耐药情况较为严重。     

一株猪源大肠杆菌的分离鉴定和药敏试验

为了弄清贵州省某猪场仔猪腹泻病原,试验采用细菌分离培养、形态学观察、生化试验、16S rRNA基因的核苷酸同源性比较及构建系统进化树、药敏试验等方法对病料进行研究。结果表明:从贵州省某猪场腹泻仔猪病例中分离到1株革兰氏阴性杆菌,命名为GF株,该菌株与NCBI上大肠杆菌分离株的同源性为99.5%~99.9%,与大肠杆菌菌株84(登录号为MF399285.1)在同一遗传进化分支上;分离的大肠杆菌GF株对卡那霉素、环丙沙星和氧氟沙星高度敏感,对头孢曲松中度敏感,对其他药物低度敏感或不敏感。     

江汉平原猪场仔猪黄白痢的诊断及防治

从江汉平原部分猪场严重腹泻的仔猪中采集24份仔猪黄痢、白痢粪便样品,共分离鉴定出8株大肠杆菌。药敏试验结果表明,所分离到的8株大肠杆菌对氧氟沙星、头孢噻肟、磺胺六甲、头孢拉啶等药物最敏感。利用强毒分离菌株研制成油乳剂灭活菌苗对产前15 d母猪和初生仔猪进行免疫,疫苗对仔猪保护率达到100%,结果表明利用地方流行强毒分离菌株作为抗原制备疫苗进行免疫可有效预防猪场仔猪黄白痢的发生。     

Occurrence of methicillin-resistant Staphylococcus aureus in rats living on pig farms

In The Netherlands, MRSA ST398 has emerged in hospitals and human carriers have been associated with exposure to pigs and cattle. High prevalences of MRSA ST398 in pigs and pig farmers have been determined and the transmission routes of MRSA on pig farms need to be elucidated. In the south of the Netherlands, in recent years, the black rat (Rattus rattus) has emerged as a prominent rodent on livestock farms. From March till May 2008, a survey on MRSA in rats living on livestock farms in the south of The Netherlands and the north of Belgium was conducted. In total, 40 black rats (R. rattus) and 3 brown rats (Rattus norvegicus) were collected on 12 farms including five pig farms, five poultry farms, one mixed pig and veal farm and one goat farm. MRSA ST398 was detected in black rats captured at two of the five pig farms as well as in a black rat living on the mixed pig and veal farm. From one black rat captured at another pig farm MRSA ST 97 was isolated. Considering the behaviour of rats on livestock farms, it is concluded that rats might play a role in the spread and persistence of MRSA on pig farms.     

仔猪球虫病及其防控措施

仔猪球虫病是困扰猪场的主要疾病之一，病原是猪等孢球虫。该病在临床上主要引起1~3周龄仔猪腹泻，造成仔猪生长速度缓慢，断奶体重明显降低。单纯的球虫感染引发的死亡率虽然不高，但遇到产房里其他疾病混合感染时可能出现死亡率的大幅度上升。猪等孢球虫在全世界的猪场感染率都很高，影响了猪场经济效益，但由于死亡率不高往往容易被猪场忽视，特别是在隐性感染症状不明显的猪场。文章回顾了等孢球虫的生活史、国内外的流行病学、检测方法以及控制方案，希望能为广大养猪从业者控制仔猪球虫病提供一个清晰的思路。     

Methicillin‐Resistant Staphylococcus aureus (MRSA) ST398 in Pig Farms and Multispecies Farms

During the last few years, methicillin‐resistant Staphylococcus aureus (MRSA) ST398 has been isolated frequently from livestock, especially from pigs and to a lesser extent from cattle and poultry. To gain insight into the distribution of this bacterium in pig farms versus multispecies farms, 30 Belgian farms (10 pig, 10 pig/poultry and 10 pig/cattle farms) were screened for the presence of MRSA. On each farm, 10 nasal swabs were taken from pigs. When present, cattle (n = 10) were sampled in the nares and poultry (n = 10) in the nares, earlobes and cloaca. A selection of the obtained isolates were further characterized using multilocus sequence typing (MLST), spa typing, SCCmec typing, pulsed field gel electrophoresis (PFGE), multiple‐locus variable‐number tandem repeat analysis (MLVA) and antimicrobial susceptibility testing. On 26 of 30 farms, MRSA was isolated from pigs. Furthermore, MRSA was also isolated from poultry and cattle on one pig/poultry and five pig/cattle farms, respectively. All tested MRSA isolates belonged to ST398. Eight spa types (t011, t034, t567, t571, t1451, t2974, t3423 and t5943) were detected, among which t011 predominated. SCCmec cassettes type IVa and V were present in 20% and 72% of the isolates, respectively. When combining the results of the two remaining typing methods, PFGE and MLVA, eighteen genotypes were obtained of which one genotype predominated (56% of the positive farms). All MRSA isolates were resistant to tetracycline. Resistance to trimethoprim, aminoglycosides, macrolides, lincosamides, fluoroquinolones and chloramphenicol was also observed. In conclusion, there was no effect of the farm type on the MRSA status of the pigs. A statistically significant difference was observed when comparing the pig/poultry or the pig/cattle MRSA status on the multispecies farms. Additionally, a wide variety of MRSA ST398 strains was found within certain farms when combining different typing methods.     

部分地区猪细环病毒1型感染的流行情况调查

猪细环病毒1型是近年来发现的又一种环状DNA病毒,可能存在潜在致病作用.为了初步了解其流行情况,用PCR技术和ELISA技术对来自京津冀、华东与华南地区578头保育猪血清样品进行了检测.结果显示,猪细环病毒1型的核酸与抗体的猪场阳性率均为100％;核酸阳性率为73.88％,抗体阳性率为78.72％,二者之间无显著差异(...     

猪圆环病毒3型感染情况的初步调查

猪圆环病毒3型是近年来发现的又一种致病性猪圆环病毒,已在不少地区存在。为了了解猪圆环病毒3型在一些地区的流行情况,用PCR方法检测了湖南省与京津冀地区523头断奶仔猪血清样品中的病毒核酸。结果显示,猪圆环病毒3型核酸的猪场阳性率为68.75%,个体阳性率为31.74%,整体存在极显著（P<0.01）差异。进一步分析发现,病毒核酸阳性率超过20%的猪场达到50%,超过70%的猪场占18.75%,为0%的猪场占31.25%。调查结果表明,猪圆环病毒3型感染在我国一些地区广泛存在,但在不同猪场的感染率差异很大。     

Comparison of Different Commercial Serological Tests for the Detection of Toxoplasma gondii Antibodies in Serum of Naturally Exposed Pigs

Toxoplasma gondii is the aetiological agent of the zoonotic disease toxoplasmosis and transmitted among other ways by chemically and physically untreated, that is, raw pork to humans. The detection of Toxoplasma gondii is impossible by currently practiced meat inspection, but serological tests can be used to detect Toxoplasma gondii antibodies in pig herds and can consequently be helpful to identify potentially contaminated pork. Therefore, appropriate serological tests are required. In this study, serum samples of 1368 naturally exposed slaughter pigs from 73 Austrian farms were collected. Serum samples of at least 16 slaughter pigs per farm were tested. The prevalence of Toxoplasma gondii antibodies in serum was measured by a commercial available modified agglutination test (MAT) and compared to three different commercial available enzyme‐linked immunosorbent assays (ELISA). The MAT detected 6.5%, ELISA I 6.7%, ELISA II 4.8% and ELISA III 4.3% of the pigs as Toxoplasma gondii antibody positive. The agreement, according to the kappa coefficient (κ), was substantial between the MAT and ELISA I (κ = 0.62), II (κ = 0.64) and III (κ = 0.67). A better agreement was determined between ELISA I and II (κ = 0.715), ELISA I and III (κ = 0.747) and ELISA II and III (κ = 0.865). At least one pig per farm was detected Toxoplasma gondii antibody positive in 17 (23.3%) farms by the MAT, 26 (35.6%) farms by ELISA I, 16 (21.9%) farms by ELISA II and 11 (15.1%) farms by ELISA III. Pig farms with a high number of Toxoplasma gondii antibody‐positive pigs or high antibody titres were identified by all of the four used serological tests. Concerning the occurrence of Toxoplasma gondii antibodies in Austrian pig farms, a monitoring and surveillance programme would be reasonable to find high‐risk farms.     

2014年－2015年湖南省规模猪场猪伪狂犬病血清学调查

为了解湖南省规模化猪场猪伪狂犬病免疫状况及猪伪狂犬病病毒(PRV)野毒感染情况,2014年－2015年,采用随机抽样的方式,采集343个不同规模猪场血清样品7049份,采用 ELISA 方法开展PRV 抗体血清学调查.结果显示,160个规模猪场中,检测免疫猪血清3415份,PRVgB 抗体合格数为2206份,合格率仅为64．60％,表明规模猪场猪伪狂犬病免疫不确实;343个规模猪场中,210个规模猪场PRVgE 抗体阳性,场阳性率61．22％;检测猪血清样品7049份,PRVgE 抗体阳性数为 1661份,阳性率为23．56％,其中2014年 PRVgE 抗体阳性率为21．71％,2015年 PRVgE 抗体阳性率为25．17％,呈上升趋势.全省14个市州的规模猪场均存在不同程度的 PRV 感染,不同地区感染率差异明显,永州感染率最高,长沙感染率最低.不同养殖规模 PRV 的感染率不尽相同,其中,存栏数200头以下 PRV 感染率较高,存栏数500~1000头感染率较低;种猪场免疫抗体优于商品猪场,PRV 感染率较商品猪场低.结果表明,PRV 在湖南省感染普遍存在,疫苗免疫在一定程度上可以阻止临床病例,但仍然无法根除隐性感染,对规模猪场伪狂犬病采取综合防控和净化措施势在必行.     

养猪场生物安全体系的建设

近年来中国养猪企业疫病频发,给养猪业带来很大的经济损失。为了减少养猪场猪的发病,保证猪场的正常生产秩序,猪场生物安全体系的建设尤为重要。笔者根据猪场的生产实际,总结出相应的实施方案,供广大养殖户参考使用。     

福州市部分种猪场主要疫病流行病学调查报告

通过现场走访和随机采样检测等形式,选择福州辖区内获得省级《种畜禽场生产经营许可证》的4家条件较成熟的种猪场开展主要动物疫病流行病学调查。结果显示3个场基本具备开展无猪伪狂犬病的评估认证条件,其他病种通过查找原因、调整免疫方案和开展免疫效果评价与病原检测等措施,逐步达到各病种的净化条件,可在全市种猪场中起示范、推动作用。     

Epidemiology of Subclinical Salmonellosis in Wild Birds from an Area of High Prevalence of Pig Salmonellosis: Phenotypic and Genetic Profiles of Salmonella Isolates

The epidemiology of subclinical salmonellosis in wild birds in a region of high Salmonella prevalence in pigs was studied. Three hundred and seventy‐nine faecal samples from 921 birds trapped in 31 locations nearby pig premises, and 431 samples from 581 birds of 10 natural settings far from pig farms were analysed for the presence of Salmonella spp. Positive samples were serotyped and analysed for antimicrobial resistance (AR). Phage typing and pulsed‐field gel electrophoresis (PFGE) on Salmonella Typhimurium isolates were also carried out. The overall proportion of Salmonella‐positive samples was 1.85% (95% CI = 0.93, 2.77). Salmonella isolation was positively associated with samples collected from birds in the proximity of a pig operation (OR = 16.5; 95% CI = 5.17, 52.65), and from non‐migratory (or short‐distance migration) birds (OR = 7.6; 95% CI = 1.20, 48.04) and negatively related to mostly granivorous birds (OR = 0.4; 95% CI = 0.15, 1.13). Salmonella Typhimurium was the most prevalent serotype and four different XbaI PFGE patterns were observed that matched the four phage types identified (U310, U311, DT164 and DT56). Only 20% of the strains showed multi‐AR. In three farms, a high degree of homogeneity among isolates from different birds was observed. These findings suggested that pig farms may act as amplifiers of this infection among wild birds, and the degree of bird density may have much to do on this transmission. Some of the Salmonella serotypes isolated from bird faeces were of potential zoonotic transmission and associated with AR. Monitoring salmonellosis in wild bird is advised.