鸭致病性大肠杆菌的分离鉴定及灭活苗的研制

从上海松江新桥病死鸭的病料中分离到的细菌,用法国梅里埃公司生产的生化反应条进行检验,证明其为大肠埃希氏菌（可信度98％）。分离菌株接种5日龄雏鸭,可使80％的雏鸭在24小时内死亡,剖检存活鸭可见典型大肠杆菌病变。并用分离的致病菌研制的灭活苗,雏鸭在实验室免疫、攻强毒等试验及小批量试验,取得了较好的免疫效果。     

重庆市近郊区县鸭传染性浆膜炎病病原分离鉴定及防治

通过对重庆近郊的沙坪坝区、北碚区、九龙坡区、永川市、璧山县、铜梁县的7个养鸭场病死鸭的病原分离,分离到三株细菌,经染色镜检、生化鉴定、动物回归实验,确诊为鸭里氏杆菌。药敏试验结果显示对庆大霉素、青霉素、链霉素、土霉素等高度敏感。在临床上交替使用这些药物,收到较好治疗效果。将分离菌制成灭活苗免疫1周龄的健康鸭,20日龄时用分离菌进行攻毒,平均保护率达83.3%。     

鸭疫里默氏菌油乳剂疫苗的免疫期和保存期的测定

鸭疫里默氏菌(Riemerellaanatipestifer,RA)病主要侵害7～42日龄的各种雏鸭,已成为危害我省养鸭业的主要细菌性传染病。去年,我们已研制出具有较高保护率的鸭疫里默氏菌油乳剂疫苗[1]。为了测定该疫苗的有效免疫期和保存期,我们进行了试验,现报道如下:1　材料与方法　1.1　菌株　系本室自行分离、鉴定、保存的型RA菌株,供制苗及攻菌保护试验用。1.2　疫苗　鸭疫里默氏菌灭活油乳剂疫苗(批号为980811),置于4～8℃保存备用。1.3　试验鸭　取3日龄健康半番鸭200羽,其中180羽用于免疫期测定,20羽用于保存期测定,试验分组情况见表1。表1　　RA…     

鸭巴氏杆菌病的诊治

鸭巴氏杆菌病又名鸭霍乱、鸭出血性败血症,俗名“摇头瘟”,能引起各种日龄的鸭发病,但以一月龄以内的鸭发病率和发病死亡率最高。笔者对四川广安某水库养的700只左右接近成年的良种种鸭,发生在夜间或白天也难以看见任何临床症状的快速死亡,进行了临床观察,病理剖检,病原菌分离、鉴定以及血清分型等,确诊为由多杀性巴氏杆菌感染引起的鸭巴氏杆菌病。用分离菌进行药敏试验和疫苗研制,用筛选的药物进行全群治疗,控制以后,再用分离菌制成的菌苗进行免疫,很快控制了本病,且很长时间后都不再发生本病。现报道如下。1临床症状大部份鸭死亡时看不见…     

O46血清型鸭源致病性大肠杆菌

为了研究分离自12日龄雏鸭的O46血清型致病性大肠杆菌在鸭不同组织器官的分布,试验用该菌人工感染12日龄试验鸭后,于不同时间采取鸭各组织器官制作冰冻切片,进行直接荧光抗体染色,观察该菌在不同组织器官的分布.结果表明:特异性荧光首先出现在肝脏、心脏、脾脏、肺脏等内脏器官,而后出现于胸腺、法氏囊等免疫器官,最后在脑部也有可...     

鸭源巴氏杆菌的分离鉴定及药敏试验

本试验为确定江西新余地区鸭发病的病原,对3个鸭场的病死鸭进行细菌分离,并通过形态特征、培养特性和生化试验对分离菌进行鉴定。从病死鸭的肝脏和心脏中分离到5株鸭多杀性巴氏杆菌,且分离菌对试验鸭和小白鼠有较强的致病性。药敏试验结果表明,分离的5株菌对左氧氟沙星、卡那霉素、头孢西丁、先锋必和大观霉素较为敏感。     

鸭疫里默菌3型河南株的分离与鉴定

为了研究鸭疫里默菌的生物学特性及其发病机制,从河南地区某鸭场临床症状、剖检病变疑似鸭疫里默菌病例进行细菌分离,从中分离到1株细菌。对分离的病菌进行形态培养、生化试验、动物试验、琼扩试验和血清型鉴定,鉴定为鸭疫里默菌3型。药敏试验表明鸭疫里默菌对头孢噻肟、卡那霉素、环丙沙星等敏感性较高。     

鸭疫里默氏杆菌病的防治

鸭浆膜炎是由鸭疫里默氏杆菌引起的传染病，该菌有21个血清型。本试验通过对发病鸭的临床诊断和病原进行分离鉴定。用本场的菌株制作灭活苗进行预防免疫，取得了很好的防治效果，保护率高达90％以上。     

鸭疫里默氏菌和大肠杆菌混合感染的诊断及防制

湖南某鸭场发生了一起20日龄雏鸭出现精神沉郁、食欲减退、嗜睡、缩颈、拉稀及神经症状为特点的疫病，经流行病学调查、临床症状、病变观察及病原分离鉴定为鸭疫里默氏菌和鸭大肠杆菌混合感染，针对分离菌作药敏试验，用对分离菌敏感的药物治疗及采取综合性的防制措施后，疫情很快得到控制。     

鸭疫里默菌的分离鉴定与动物回归实验

为了解最近吉林地区某鸭场大量鸭病死的原因,对该鸭场送检的病料进行细菌分离培养并成功分离出一株革兰阴性菌。通过生化试验、16S r RNA鉴定及序列测序分析、玻片凝集试验和动物回归试验等对分离菌进行鉴定,16S r RNA基因测序结果显示,分离菌与鸭疫里默菌同源性达到99%;该菌能够使雏鸭死亡且致病性较强。结果表明,该鸭场鸭群死亡原因是1株血清2型鸭疫里默菌感染。     

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     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -     

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.