新疆石河子地区牛支原体的分离鉴定及药物敏感性分析

【目的】确定引起新疆石河子地区集约化牛场常发性肺炎的主要病原同时进行病原的体外药物敏感性分析。【方法】采集有典型咳嗽、流涕症状的牛鼻拭子10份和病死牛肺脏组织1份,用牛支原体特异性引物进行PCR检测,将检测为阳性的样本进行病原培养纯化,对纯化后的分离株菌落进行形态学观察、Dienes染色、生化试验及16S rRNA测序和进化分析,通过测定颜色变化单位(CCU)测定分离株生长曲线,并对分离株进行药物敏感性试验。【结果】PCR结果显示,10份鼻拭子中检测出7份牛支原体阳性样本,1份病死牛肺脏组织也检测为阳性;在涂有肺脏组织研磨液培养液的PPLO固体培养基上长出针尖状的菌落,纯化后分离株菌落形态为典型的煎蛋状;Dienes染色可见明显的深蓝色中心脐;生化试验结果显示,分离株不水解明胶、精氨酸、七叶苷,不发酵乳糖、葡萄糖和甘露醇,不分解尿素,可还原氯化三苯基四氮唑;16S rRNA测序结果显示,分离株与牛支原体国际标准株PG45相似性为99.7%,与国内牛支原体地方流行株XBY01、Ningxia-1、NM2012、Tibet-10的相似性最高,均为99.9%;生长曲线测定结果显示,分离株在培养基中生长6 h后进入对数生长期,54 h时达到高峰进入稳定期,72 h后进入衰亡期;药物敏感性试验结果显示,分离株对呋喃妥因、四环素和多西环素、庆大霉素和卡那霉素敏感,对诺氟沙星和氧氟沙星中介,而对环丙沙星、洛美沙星及阿奇霉素和红霉素耐药。【结论】本研究成功从肺脏组织中分离鉴定出1株牛支原体,培养54 h是该分离株的最佳收获时间,与国内大多数牛支原体地方流行株差异较小,整体遗传进化相对稳定,有一定的耐药性,本研究结果可为当地对牛支原体的防控提供参考,也为牛支原体致病机制研究及疫苗研发奠定基础。     

粪肠球菌替代抗生素对断奶仔猪生长性能、腹泻率、血液生化指标和免疫器官的影响

本试验在断奶仔猪饲粮中添加不同水平的粪肠球菌,研究其替代抗生素对断奶仔猪生长性能、腹泻指数和腹泻率、血液生化指标以及免疫器官的影响。选取120头(28±2)日龄平均体重为(7.60±0.81)kg的"杜×长×大"断奶仔猪,随机分为5组,每组6个重复(公母各占1/2),每个重复4头,每个重复为1圈。对照组饲喂基础饲粮,抗生素组在基础饲粮中添加100mg/kg硫酸黏菌素和400 mg/kg杆菌肽锌,3个粪肠球菌组分别在基础饲粮中添加40、200和1 000 mg/kg粪肠球菌,试验期31 d。试验结果显示:1)在1~14 d,饲粮中添加抗生素和粪肠球菌对断奶仔猪的平均日采食量(ADFI)、平均日增重(ADG)以及料重比(F/G)无显著影响(P0.05)。在15~31 d,与对照组和抗生素组相比,200和1 000 mg/kg组可极显著提高ADFI和ADG(P0.01)。在1~31 d,与对照组相比,200和1 000 mg/kg组的ADFI均极显著提高(P0.01),而ADG分别显著和极显著增加(P0.05和P0.01);与抗生素组相比,1 000 mg/kg组可极显著提高ADFI(P0.01),而200和1 000 mg/kg组的ADG分别显著和极显著增加(P0.05和P0.01)。2)在1~14 d,与对照组相比,40 mg/kg组的腹泻指数和腹泻率显著降低(P0.05)。在15~31 d和1~31 d,与对照组和抗生素组相比,40和1 000 mg/kg组均可在一定程度上降低腹泻率(P0.05)。3)与对照组相比,粪肠球菌可以显著提高血液中总蛋白含量(P0.05),其中200和1 000 mg/kg组达到极显著水平(P0.01),且这2组分别可以显著和极显著提高球蛋白含量(P0.05和P0.01)。与抗生素组相比,200和1 000 mg/kg组可以显著提高总蛋白含量(P0.05)。与对照组相比,抗生素组和1 000 mg/kg组的白球比显著降低(P0.05),另外,抗生素组血液中谷丙转氨酶和谷草转氨酶活性显著降低(P0.05),200 mg/kg组的谷丙转氨酶活性显著降低(P0.05)。4)与对照组相比,1 000 mg/kg组的肝脏重量和脾脏指数有一定程度的提高(P0.05),与抗生素组相比,200和1 000 mg/kg组可显著提高肝脏重量(P0.05)。结果表明,饲粮中添加粪肠球菌可改善断奶仔猪的生长性能(饲喂15~31 d),降低腹泻率,提高仔猪免疫力,其中添加量为1 000 mg/kg时效果最好。     

无抗发酵饲料对生长育肥猪生长性能、肠道菌群和养分表观消化率的影响

本试验旨在研究无抗发酵饲料对生长育肥猪生长性能、肠道菌群和养分表观消化率的影响。选择18 kg左右断奶仔猪60头,随机分为2个组,每组3个重复,每个重复10头猪。对照组饲喂含抗生素基础饲粮(每千克含黄霉素5 mg),试验组饲喂80%基础饲粮和20%的无抗发酵饲料组成的试验饲粮。试验期154 d。结果表明:1)试验组的末重、平均日增重和平均日采食量都显著高于对照组(P0.05),而料重比则显著低于对照组(P0.05)。2)试验组中期和后期的乳酸菌数量的对数值显著高于对照组(P0.05),而试验组中期和后期的大肠杆菌和沙门氏菌数量的对数值显著低于对照组(P0.05)。3)在十二指肠肠段,试验组肠道食糜中的乳酸菌和大肠杆菌数量的对数值显著高于对照组(P0.05)。4)在十二指肠肠段,试验组肠道每克和每平方厘米黏膜的乳酸菌数量的对数值显著高于对照组(P0.05);试验组肠道每克黏膜的大肠杆菌数量的对数值显著高于对照组(P0.05)。在空肠肠段,试验组肠道每克和每平方厘米黏膜的乳酸菌数量的对数值显著高于对照组(P0.05)。5)试验组的粗蛋白质和粗纤维的表观消化率显著高于对照组(P0.05)。由此可见,无抗发酵饲料能提高生长育肥猪的生长性能,改善肠道微生物平衡,增强消化能力。     

Challenges of thermal nociceptive threshold testing in the donkey

ObjectiveTo evaluate a thermal nociceptive threshold (TNT) testing device in the donkey, and the influence of potential confounding factors on TNTs.AnimalsTwo groups (Group 1 and Group 2) of eight castrated male donkeys aged 4–9 years, weighing 105–170 kg.MethodsTNTs were measured by heating a thermal probe on skin until an end-point behaviour (threshold temperature) or a cut-out temperature (51 °C) was reached. The withers and the dorsal aspect of the distal limb were used as sites for TNT testing. The effects on TNT of different confounding factors: the limb tested; rate of heating; and ambient temperature were evaluated. Data were analyzed using general linear models, and Mann-Whitney tests, p < 0.05 was considered significant.ResultsEnd-point behaviours (skin twitch or donkey looking at test device) when the thermal probe heated the withers were observed in approximately half of tests. TNT was (mean ± SD) 46.8 ± 2.85 °C. Subsequently the limb was evaluated as the test site in Group 1 followed by Group 2 donkeys; end-point behaviour being a foot-lift. In Group 1, 72% of tests ended in an end-point behaviour but the response rate was lower in Group 2 (20%), although TNTs were similar [(47.6 ± 3.3) and (47.3 ± 3.0) °C respectively] for responding animals. Rate of heating, ambient temperature and laterality (right or left) did not affect thresholds, but mean TNT was significantly higher in the forelimb (48.5 ± 2.8 °C) than the hind limb (47.4 ± 2.8 °C) (p = 0.012).ConclusionsWhen a thermal probe cut-out temperature of 51 °C was used in TNT testing in the donkey a high proportion of tests did not produce an identifiable end point behaviour. Higher cut-out temperatures damaged the skin. Under these conditions, thermal nociceptive threshold testing appears not be an appropriate analgesiometry technique in the donkey.Clinical relevanceTNT testing under these conditions is not suitable form of analgesiometry for donkeys.     

四川省部分地区山羊沙门氏菌健康带菌率及耐药性调查

为了解四川省山羊沙门氏菌带菌情况,本试验采集了四川省部分地区5个规模化山羊养殖场表观健康山羊粪便196份,经BPW预增菌、TTB选择性增菌后,采用靶向invA基因的PCR方法检测沙门氏菌的带菌率;对阳性样本进行细菌分离鉴定,随机选择25株沙门氏菌分离株测定其对15种抗菌药物的敏感性。结果显示,山羊沙门氏菌的平均带菌率为54.59%。药敏试验结果显示,分离株均对丁胺卡那敏感,而对其余14种抗菌药物呈不同程度的耐药,多重耐药菌株占88%,其中耐2~7种药物的占52%,耐9~13种药物的占36%。结果表明,四川省部分地区山羊的沙门氏菌健康带菌率较高,且多重耐药性普遍,其公共卫生意义值得进一步研究。     

Isolation,Identification and Analysis of Serotype and Antibiotic Susceptibility of Pathogenic Salmonella from Chickens

To investigate the situations of predominant strain and antibiotic resistance of pathogenic Salmonella from chickens in Guangxi Zhuang Autonomous region, Salmonella was pre-enriched and isolated from tissues of clinical suspected chickens, and the Salmonella isolates were identified by biochemical test using ID 32E System for the identification of Enterobacteriaceae of VITEK System ATB Expression, serotypes were determined by slid agglutination test, antibiotic susceptibility was analyzed by ATB VET Susceptibility Test Strip of Enterobacteriaceae antibiotics.The results showed that 34 Salmonella strains were obtained from 310 clinical samples, of which 1 strain belonged to A serogroup, 1 to C2 serogroup, 15 to B serogroup, 14 to D serogroup and 3 to untyped serogroup, and S.typhimurium of B serogroup and S.pullorum of D serogroup were the predominant serotypes.All Salmonella isolates were sensitive to meropenem, imipenem, spectinomycine and apramycine, and the resistance rates to chloramphenicol, kanamycine and gentamicine were less than 10%, and the resistance rates to amoxicillin, streptomycine, flumequine, oxolinique, sulfamethizol, tetracycline and nitrofurantoine ranged between 50% and 90%, while the resistance rates to penicilline, oxacilline, fusidique, rifampicine and metronidazole reached to 100%.The results indicated that the serotype distribution of pathogenic Salmonella from chickens exhibited regional characteristics, and S.typhimurium and S.pullorum were the predominant serotypes in Guangxi Zhuang Autonomous region, and antibiotic resistance of Salmonella isolates was very serious which should be highly concerned.     

人工神经网络在木材缺陷检测中的应用

采用射线作为检测手段，对木材进行无损检测。在无损检测信号处理和特征构造的基础上。运用特征参数建立了缺陷识别的数学模型，针对无损检测信号的特征，构造了人工神经网络。选用反向传播神经网络模型（BP网络），网络识别所需要的特征参数能够反映木材缺陷的全部特征。     

浙南地区杉木杂交组合再选择的研究

对4片定植于浙江和江西两地的全同胞试验林进行调查,评选出的若干优良杂交组合,进行重复制种和区域 化造林试验。于2001年11月份调查了遂昌试点3年生的杉木全同胞试验林,测定树高,地径,轮盘数,冠幅和成活 率5个性状,经过方差分析,方差一协方差分析和综合指数分析,初步评出9702(龙15×1339);9706(1419×1339); 9703(龙15×闽33)3个全同胞家系,其表聊突出,3年生树高超过223 cm,同时适应性也强,造林成活率在97．9％ 以上,值得在浙江省南部类似地区推广应用。     

荷花木莲花粉活力测定方法比较

以荷花木莲新鲜花粉为试验材料,用醋酸洋红染色法、TTC染色法、液滴培养法、琼脂滴培养法和琼脂薄层涂片培养法对其花粉生活力进行了测定.结果表明:醋酸洋红染色法和TTC染色法测定结果极显著高于离体萌发培养法,不宜用于荷花木莲花粉生活力的测定;在三种离体萌发培养法中,液滴培养法最简单,结果直观稳定,是最适合的花粉生活力测试方法.     

Towards a Pan‐European Assessment of Land Susceptibility to Wind Erosion

Understanding spatial and temporal patterns in land susceptibility to wind erosion is essential to design effective management strategies to control land degradation. The knowledge about the land surface susceptible to wind erosion in European contexts shows significant gaps. The lack of researches, particularly at the landscape to regional scales, prevents national and European institutions from taking actions aimed at an effective mitigating of land degradation. This study provides a preliminary pan‐European assessment that delineates the spatial patterns of land susceptibility to wind erosion and lays the groundwork for future modelling activities. An Index of Land Susceptibility to Wind Erosion (ILSWE) was created by combining spatiotemporal variations of the most influential wind erosion factors (i.e. climatic erosivity, soil erodibility, vegetation cover and landscape roughness). The sensitivity of each input factor was ranked according to fuzzy logic techniques. State‐of‐the‐art findings within the literature on soil erodibility and land susceptibility were used to evaluate the outcomes of the proposed modelling activity. Results show that the approach is suitable for integrating wind erosion information and environmental factors. Within the 34 European countries under investigation, moderate and high levels of land susceptibility to wind erosion were predicted, ranging from 25·8 to 13·0 M ha, respectively (corresponding to 5·3 and 2·9% of total area). New insights into the geography of wind erosion susceptibility in Europe were obtained and provide a solid basis for further investigations into the spatial variability and susceptibility of land to wind erosion across Europe. © 2014 The Authors. Land Degradation and Development published by John Wiley & Sons, Ltd.