氟甲砜霉素与氯霉素抗菌作用比较

采用试管2倍稀释法,测定了氟甲砜霉素和氯霉素对鸡白痢沙门氏菌、禽巴氏杆菌、猪链球菌、禽大肠杆菌、金黄色葡萄球菌、鸭疫李氏杆菌等6种畜禽常见病原菌的最小抑菌浓度(MIC)。结果表明,氟甲砜霉素对受试菌的抗菌作用与氯霉素基本一致。     

氟甲砚霉素与氯霉素抗菌作用比较

采用试管2倍稀释法，测定了氟甲砚霉素和氯霉素对鸡白痢沙门氏菌、禽巴氏杆菌、猪链球菌、禽大肠杆菌、金黄色葡萄球菌、鸭疫李氏杆菌等6种畜禽常见病原菌的最小抑菌浓度（MIC）。结果表明，氟甲砚霉素对受试菌的抗菌作用与氯霉素基本一致。     

5种抗菌药物对嗜水气单胞菌的体外抗菌后效应研究

为比较研究水产养殖中几种常见抗菌药物对嗜水气单胞菌(A.hydrophila)的体外抗菌后效应(PAE),本研究选取5种典型的抗菌药物(恩诺沙星、盐酸多西环素、诺氟沙星、氟苯尼考以及甲砜霉素),采用常量肉汤稀释法测定它们对A.hydrophila的最小抑菌浓度(MIC)和最小杀菌浓度(MBC),并在0、1/2 MIC、1 MIC、2 MIC和4 MIC药物浓度下进行PAE诱导,再用活菌计数法测定并记录细菌生长曲线,计算PAE值。结果显示,5种抗菌药物的MIC和MBC分别为0.016和0.023μg/m L(恩诺沙星),0.250和0.500μg/m L(盐酸多西环素),0.250和0.500μg/m L(诺氟沙星),1和4μg/m L(氟苯尼考)以及2和4μg/m L(甲砜霉素);5种抗菌药物在不同浓度下均有一定的PAE,其中盐酸多西环素最长可达2.84 h。本研究结果表明,这5种抗菌药物对A.hydrophila均有相当的PAE,并且在一定范围内呈浓度依赖性。提示在治疗鱼病及临床给药时,可以考虑PAE的独有特性,延长给药间隔,科学用药。     

氟苯尼考粉对鸡金黄色葡萄球菌病的疗效试验

氟苯尼考(Florphenicol，又名氟甲砜霉素，是一种新型兽医专用氯霉素类抗菌药物，其抗菌谱广，吸收好，安全，对敏感菌所致的禽畜细菌性疾病治疗效果显著。氟苯尼考对耐氯霉素及甲砜霉素的细菌仍然敏感，如金黄色葡萄球菌，大肠埃希氏菌、多杀性巴氏杆菌、奇异变形杆菌、胸膜肺炎放线杆菌与伤寒沙门氏菌等，而且氟苯尼考无氯霉素的再生障碍性贫血的不良反应，     

PVPK氟苯尼考固体分散体的制备及体外溶出速率的研究

氟苯尼考(氟甲砜霉素，Florfenicol)是美国先灵葆雅公司研制的兽用广谱抗菌药物，为人工合成的甲砜霉素单氟衍生物。氟苯尼考广谱抗菌，对猪胸膜肺炎放线杆菌、多杀性巴氏杆菌、支气管败血波氏杆菌、链球菌、副猪嗜血杆菌、沙门氏菌、大肠杆菌等革兰阳性和阴性细菌及支原体均有强大的杀伤力。其抗菌活性明显优于氯霉素和甲砜霉素(MIC约为10倍)，目前该药在兽医临床上应用非常广泛，但该药的可溶性剂型目前还没有质量标准，     

两种有机酸AFG和WD与利高霉素之间的互作效应的研究

本研究目的是确定利高霉素和液态有机酸对不同致病菌的最小抑菌浓度(MIC)以及利高霉素和液态有机酸联合应用时的相互作用.采用试管二倍稀释法分别测定有机酸AFL、WD和利高霉素对鸡大肠杆菌、鸡沙门氏菌和金黄色葡萄球菌的MIC值,并采用棋盘格法测定两种有机酸与利高霉素的联合用药时的相互作用.结果表明,有机酸AFL和WD对鸡大肠杆菌、鸡沙门氏菌和金黄色葡萄球菌的MIC值均为0.078125%,利高霉素对鸡大肠杆菌、鸡沙门氏菌和金黄色葡萄球菌的MIC值分别为16ug/mL、16ug/mL和8ug/mL;有机酸AFL和WD与利高霉素联合药敏试验表明:两种有机酸和利高霉素的相互作用为无关作用,不会产生相互干扰.     

规模化鸡场五种常用消毒剂的消毒效果评价

为研究规模化鸡场五种常用消毒剂(过氧乙酸、聚维酮碘、稀戊二醛、月卞三甲氯铵、烧碱)对金黄色葡萄球菌、大肠杆菌和沙门氏菌的消毒效果,采用倍比稀释法分别测定这五种消毒剂的最低抑菌浓度(MIC)和最低杀菌浓度(MBC)。结果显示:五种消毒剂中,月卞三甲氯铵对金黄色葡萄球菌和肠炎沙门氏菌的最低抑菌浓度最小,过氧乙酸对大肠杆菌的最低抑菌浓度最小;月卞三甲氯铵对金黄色葡萄球菌和肠炎沙门氏菌的最低杀菌浓度最小,过氧乙酸对大肠杆菌的最低杀菌浓度最小。试验表明,月卞三甲氯铵对金黄色葡萄球菌和肠炎沙门氏菌的杀菌作用最强,过氧乙酸对大肠杆菌的杀菌作用最强。     

国内氟苯尼考的合成与开发进展

氟苯尼考是由美国Schering-Plough公司Nagab-husban等在70年代末为寻求更好的氯霉素类衍生物中研制开发的产品，化学名称：D（＋）-苏-1-对甲砜基苯基-2-二氯乙酰氨基-3-氟丙醇，对敏感菌的抗菌活性与氯霉素和甲砜霉素相似，但对耐氯霉素及甲砜霉素的细菌仍敏感，如大肠杆菌、克雷白氏杆菌、溶血性巴氏杆菌、金黄色葡萄球菌、胸膜肺炎放线杆菌及伤寒沙门氏菌等。氟苯尼考于1996年通过美国FDA注册登记，商品名分别为Florocol和Nuflox。     

氟苯尼考与多种抗菌药物联合应用对大肠杆菌的体外抑菌试验

为了解氟苯尼考分别与恩诺沙星、TMP和多西环素联合用药的体外抑菌效果,本试验采用倍比稀释法,测定了氟苯尼考、恩诺沙星、TMP和多西环素对大肠杆菌O78的最小抑菌浓度(MIC);采用棋盘法进行恩诺沙星、TMP、多西环素分别与氟苯尼考联合应用对大肠杆菌的药敏试验。结果表明:四种抗菌药物都有较强的抑菌能力,氟苯尼考MIC为4μg/mL,恩诺沙星MIC为0.1μg/mL,TMP的MIC为16μg/mL,多西环素的MIC为4μg/mL。氟苯尼考与恩诺沙星联合表现为无关作用,与TMP联合表现为协同作用,与多西环素联合表现为累加作用。     

石榴皮水提物与几种抗菌药物体外联合抗菌作用观察

为评价石榴皮水提物与抗菌药物体外联合抗菌作用的效果,试验采用双层打孔法检测石榴皮水提物的抑菌能力,采用微量二倍稀释法测定石榴皮水提物的最小抑菌浓度(MIC),使用棋盘法测定石榴皮提取物与庆大霉素、阿米卡星、链霉素、多西环素和恩诺沙星联用对金黄色葡萄球菌和大肠杆菌的作用效果。结果表明：制备的石榴皮水提物具有抑菌效果;对金黄色葡萄球菌和大肠杆菌的MIC分别为1.25 mg/mL和5 mg/mL;石榴皮水提物联合阿米卡星对大肠杆菌表现为相加作用,联合链霉素对大肠杆菌和金黄色葡萄球菌均表现为相加作用,联合庆大霉素对大肠杆菌表现为颉颃作用。说明石榴皮水提物可以与阿米卡星和链霉素联用,均表现为相加作用。     

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.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

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

Tropical Animal Health and Production -     

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.     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

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