血清3型鸭疫里默氏杆菌在我国的发现及其病原特性研究

1994年1月－2000年10月，从全国28个省（市、自治区）不同代次（原种、祖代、父母代和商品代）的5－90日龄患有典型鸭传染性浆膜炎的病死鸭分离到102株血清3型的鸭疫里默氏杆菌。分离菌株对雏鸭具有很强的致病性，各分离菌株表现出一致的形态特征和非常相似的生理生化特性，耐药谱也很广。但各分离株对头孢类药物（如头孢拉啶、头孢克洛等）和利福平却普遍高度敏感。用分离菌株制备的灭活疫苗免疫雏鸭具有良好的免疫原性。     

血清8型鸭疫里墨氏杆菌在我国的发现及其病原特性研究

1994年1月-2000年10月，从全国23个省（市，自治区）不同代次（原种，祖代，父母代和商品代）的5-90日龄患有典型鸭传染性浆膜炎的病死鸭分离到68株血清8型的鸭疫里墨氏杆菌，对其病原学特性进行研究的结果表明，血清8型的鸭疫里墨氏杆菌在我国鸭群感染分布的范围极广，分离菌株对雏鸭具有很强的致病性，对小鼠无致病性，各地分离菌株表现出一致的形态特征和非常相似的生理生化特性；各地分离菌株耐药谱很广，但对头孢类药物（如头孢拉啶，头孢克洛等）和利福平却普遍高度敏感。用分离菌株制备的灭活疫苗免疫雏鸭具有良好的免疫原性。     

鸭疫里默氏杆菌血清7型的病原特性

1994年1月～2000年10月,从全国23个省(市、自治区)不同代次(原种、祖代、父母代和商品代)的5～90日龄患有典型鸭传染性浆膜炎的病死鸭分离到87株血清7型的鸭疫里默氏杆菌(Riemerella anatipestifer,RA).对其病原学特性研究的结果表明,血清7型RA在我国鸭群感染分布的范围极广,分离菌株对雏鸭具有很强的致病性,对小鼠无致病性,各地分离菌株表现出一致的形态特征和非常相似的生化特性;各地分离菌株耐药谱很广,但对头孢类药物(如头孢拉啶、头孢克洛等)和利福平却普遍高度敏感.用分离菌株制备的灭活疫苗免疫雏鸭具有良好的免疫原性.     

血清15型鹅源鸭疫里默氏杆菌的分离鉴定及交叉免疫保护研究

本研究对安徽省某鹅场急性死亡的雏鹅进行了细菌分离鉴定,无菌采集病死鹅肝脏、脑和心包液,经过培养特性观察、染色镜检、生化特性检测以及16S rRNA和血清学检测,鉴定病原菌为血清15型鸭疫里默氏杆菌,命名为LAG1株。该分离菌株对四环素类药物敏感,而对卡那霉素等耐药;对雏鸭的致病性强,半数致死量(LD50)测定为7.75×103CFU/只;交叉免疫保护试验结果显示LAG1灭活油乳剂疫苗对自身菌株攻毒的免疫保护率可达80%以上,对血清10型鸭疫里默氏杆菌HXb2攻毒的保护率可达70%,对血清1型鸭疫里默氏杆菌WJ4和血清2型鸭疫里默氏杆菌Yb2攻毒的保护率低于20%。本研究结果可为安徽省养鹅业鸭疫里默氏杆菌病的防治工作提供参考。     

河北故城地区鸭疫里默氏杆菌的分离鉴定和血清型分析

对河北省故城地区送检的疑似鸭疫里默氏杆菌感染发病的病鸭进行病原菌的分离鉴定,根据培养特性和生化鉴定结果鉴定出13株鸭疫里默氏杆菌,并对分离菌进行了血清型鉴定和药物敏感试验;经玻片凝集试验和琼脂扩散试验得出血清1型5株,血清2型4株,血清6型1株,血清10型1株,还有2株未定型。试验证明血清1、2型是目前故城地区鸭疫里默氏杆菌的主要流行血清型,分离菌株对雏鸭有很强的致病性且耐药谱较广,但对氧氟沙星、盐酸恩诺沙星和氟苯尼考较为敏感。     

重庆和四川地区鸭疫里默氏杆菌流行动态研究

对2004年9月至2005年5月收集的鸭疫里默氏杆菌感染浆膜炎病例进行了流行病学调查，结果分离到57株鸭疫里默氏杆菌，经凝集试验和琼脂扩散试验证明分属8个不同的血清型，其中AF、BSY、DZ是主要血清型。分离菌株对雏鸭有很强的致病性；各地分离菌株表现一致的形态特征和相似的生理生化特性；耐药谱很广，但对头孢唑啉、环丙沙星、丁氨卡那、利福平为高度敏感。     

鸭疫里默氏杆菌血清7型的病原特性

1994年1月-2000年10月，从全国23个省(市、自治区)不同代次(原种、祖代、父母代和商品代)的5—90日龄患有典型鸭传染性浆膜炎的病死鸭分离到87株血清7型的鸭疫里默氏杆菌(Riemerell anatipestifer，RA)。对其病原学特性研究的结果表明，血清7型RA在我国鸭群感染分布的范围极广，分离菌株对雏鸡具有很强的致病性，对小鼠无致病性，各地分离菌株表现出一致的形态特征和非常相似的生化特性；各地分离菌株耐药谱很广，但对头孢类药物(如头孢拉啶、头孢克洛等)和利福平却普遍高度敏感。用分离菌株制备的灭活疫苗免疫雏鸡具有良好的免疫原性。     

鹅源鸭疫里默氏杆菌的分离和鉴定

为研究鹅源鸭疫里默氏杆菌的生化特性、药敏情况、血清型和致病性,从扬州郊区发病鹅场分离到1株细菌,经分离培养、染色镜检、生化特性鉴定、玻片凝集试验,确定为Ⅱ型鸭疫里默氏杆菌。对病料进行病毒分离试验,经过血凝试验和琼脂扩散试验,没有发现鹅新城疫病毒、禽流感病毒和小鹅瘟病毒。动物致病性试验结果表明,鸭疫里默氏杆菌分离菌株可以通过静脉注射、皮下注射和滴鼻3种途径感染鹅,出现100%的死亡率,说明分离株对扬州鹅具有很强的致病性,同时提示在鹅的免疫计划中也应该充分考虑到鸭疫里默氏杆菌的致病和传播。     

鸭疫里默氏杆菌的分离鉴定与生物学特性研究

为了解鸭疫里默氏杆菌的流行情况和药物敏感性,本研究对广东省、山东省、江苏省等地区疑似鸭疫里默氏杆菌病的病料进行病原分离和鉴定,并测定分离株对抗菌药物的敏感性。结果显示,共鉴定到46株鸭疫里默氏杆菌,其中血清1型、2型、10型和15型菌株依次为9株、25株、1株和1株,未定血清型菌株10株;RA分离株普遍对林可霉素、多粘菌素和诺氟沙星耐药,表明RA分离株对临床常用药出现了不同程度的耐受;易感鸭的动物回归试验能够复制出典型的原始病例,且可从死亡雏鸭中分离到同源菌株。该研究结果为鸭疫里默氏杆菌病疫苗选用和临床用药提供了科学的参考依据。     

鸭疫里默氏杆菌贵州分离株的耐药性及致病性分析

从贵州三穗地区某鸭场临床疑似鸭疫里默氏杆菌(Riemerella anatipestifer,RA)感染的病死鸭体内分离得到6株病原菌,经细菌形态观察、生化试验和PCR鉴定确定为RA。对6株RA分离株的血清型鉴定、耐药性及致病性试验,结果表明:6株分离菌中有4株为血清2型,其余2株血清型未定;所有分离株对大环内酯类和氨基糖苷类药物耐药,而对青霉素类和头孢类药物高度敏感;将血清2型RA菌株以9×107cfu/m L剂量经肌肉注射后可导致雏鸭发病死亡,病死鸭表现典型的鸭疫里默氏杆菌病临床症状。结果表明,贵州三穗地区主要流行血清2型RA,且对多种抗生素呈多重耐药且致病性强,应加强对血清2型RA的监测和防控。     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein     

Evaluation of the Microbiological Status of Milk and Various Structures in Mammary Glands from Naturally Infected Dairy Cows

A knowledge of the microbiological status of milk and of the different structures in the mammary glands has great importance in elucidating the pathogenesis of mammary gland infections. The objective of this study was to evaluate the microbiological status of various structures in the mammary glands from naturally infected dairy cows following slaughter. A total of 94 samples of milk, 184 samples of mammary parenchyma, 168 samples of gland cisterns, and 168 samples of teat cisterns were collected for microbiological examination. Microorganisms were detected in 59.9% of all samples, 67.0% of the milk samples, 70.1% of the mammary parenchymas, 55.9% of the gland cisterns and 48.8% of the teat cistern samples. When all samples were considered, coagulase-negative Staphylococcus were the most prevalent (35.7%) followed by coagulase-positive Staphylococcus (12.2%), Corynebacterium bovis (2.4%), Prototheca sp. (1.9%), and Streptococcus dysgalactiae (1.5%). There was a significantly higher occurrence of microorganisms in the milk and mammary parenchyma compared to the gland cisterns and teat cisterns. This revised version was published online in July 2006 with corrections to the Cover Date.     

Development and survival of free-living stages of gastrointestinal nematodes of sheep and goats on pasture in the Nigerian derived savanna

Four grass plots were sequentially contaminated with goat faeces containing known numbers of unembryonated eggs of predominantly Haemonchus contortus and Trichostrongylus spp. between October 1982 and April 1983. Four other plots were similarly contaminated with sheep faeces between February and May 1987. An additional plot was repeatedly contaminated with sheep faeces from February to April 1987. Populations of free-living stages in faeces and of infective larvae (L₃) in the herbage were subsequently monitored until the end of April and June of 1983 and 1987 respectively. During February and May 1987 two control cultures of sheep faeces were incubated in the laboratory at 25°C–30°C and at a constant temperature of 50°C and the free-living development was also monitored. L₃ developed very readily in the faeces cultured at 25°C–30°C and in those spread on a grass plot in October, at the end of the wet season, but developed less on the plot contaminated in May at the start of the wet season. Worm eggs in faeces deposited on plots during the hot dry season (December to April) or incubated at 50°C died and disintegrated after 24–48 h exposure to the high environmental temperatures. The results indicate that it is unlikely that gastrointestinal nematodes of sheep and goats can develop or survive on open pasture during the dry season in the Nigerian derived savanna zone.