Lipopolysaccharides of the Heddleston serotypes of Pasteurella multocida

Lipopolysaccharides (LPS) were extracted from 13 of the 16 Heddleston serotypes of Pasteurella multocida by phenol-chloroform-petroleum ether (PCP). Serotypes 3, 9, and 13 were extracted only by phenol-water (PW). After extraction of LPS of serotype 9 by PW, an additional LPS was isolated by PCP. All LPS contained glucose, 2-keto-3-deoxyoctonate, and heptose. Two isomers of heptose, D-glycero-D-mannoheptose and L-glycero-D-mannoheptose, were found in serotypes 2 and 5. Antisera made against purified LPS of serotypes 2 and 5 reacted with both heat-stable antigens and LPS from serotypes 2 and 5 in the gel-diffusion precipitin test. Antisera against serotype 2 LPS protected turkeys against challenge with capsulated serotype 5, indicating that a structural relationship exists between LPS of strains that cause hemorrhagic septicemia and fowl cholera. Rhamnose was a component of serotype 9 LPS, and galactose was found in all LPS, except for serotype 11. The LPS of serotype 13 contained an isomer of heptose that has not been identified. The LPS had buoyant densities in CsCl of 1.40 +/- 0.0148 g/ml, and all hemagglutinated chicken and turkey, but not sheep or horse, RBC.     

丙型副伤寒沙门氏菌脂多糖提取纯化及活性分析

为了提取、纯化天鹅源丙型副伤寒沙门氏菌脂多糖（LPS）并检测其活性,试验通过热酚水法提取丙型副伤寒沙门氏菌LPS,采用DNaseⅠ、RNase A和蛋白酶K及醇沉法纯化LPS,测定LPS提取物中多糖、蛋白及核酸的含量,鲎试剂检测凝集活性,显色基质法测定其活性。结果显示,纯化的丙型副伤寒沙门氏菌LPS平均产率为1.48%,多糖含量为3.84%,蛋白含量为1.49%,核酸含量为 5.45%,且核酸片段低于100 bp,SDS-PAGE电泳和银染结果显示条带主要集中在10～15 ku范围内,与2 EU/mL鲎试剂的最小凝集浓度是10.99 ng/mL,显色基质法测定其活性为9.82×10⁵ EU/mg。该试验提取、纯化的丙型副伤寒沙门氏菌LPS纯度较高,生物活性良好。     

Characterization of endotoxin from the rumen bacterium Megasphaera elsdenii.

Phenol-water extraction of Megasphaera elsdenii, a predominant gram-negative coccus in rumens of cattle fed high-grain diets, yielded material that exhibited typical characteristics of endotoxin. The extract was lethal to mice and to chicken embryos, caused biphasic fever in rabbits, leukopenia in mice, and local and generalized Shwartzman reactions; and induced tolerance to the lethal effect of the endotoxin in mice. The material contained carbohydrate, protein, lipid, phosphorus, and 2-keto-3-deoxyoctonate, but no nucleic acid. The beta-hydroxymyristic acid was absent. Results imply that M elsdenii endotoxin has many biological and chemical characteristics common to enterobacterial endotoxin. However, the median lethal doses in mice and in chicken embryos, and minimal dose required to elicit a local Shwartzman reaction, indicate that M elsdenii endotoxin's potency is low, which may explain why the large gram-negative bacterial population in the rumen of cattle is generally innocuous.     

Purification and further characterization of phenol extract from Listeria monocytogenes

A phenol-water extract of Listeria monocytogenes virulent strains 9-125 (serotype 4b) was purified by 3 cycles of ultracentrifugation. The purified extract reacted positively in Limulus amoebocyte lysate assay at a concentration of 1 microgram/ml. This value was 1,000 times higher than that for Salmonella abortus equi lipopolysaccharide. The phenol extract was toxic to chicken embryos (median lethal dose was 40.5 micrograms) and contained carbohydrates (heptose, hexose, hexosamine, methylpentose, 2-keto-3-deoxyoctanate, dideoxyhexose), lipid, 16 amino acids in the protein moiety, glucosamine, galactosamine, phosphorus, and ribonucleic acid.     

Biochemical characterization of an antigenic saline extract of Actinobacillus pleuropneumoniae serotype 5 and identification of a serotype-specific antigen for ELISA serodiagnosis

A saline extract of boiled-formalinized whole cells from a local strain (81–750; Quebec, Canada) of Actinobacillus pleuropneumoniae, serotype 5b was used as an antigen in an enzyme-linked immunosorbent assay (ELISA) for serodiagnosis of swine pleuropneumonia. Characterization of this crude extract was done and proteins, neutral sugars, hexosamines, and 2-keto-3-deoxyoctonate (KDO) were evaluated. On phenol extraction of the crude extract a serotype-specific antigen of polysaccharidic nature was recovered from the aqueous phase. This antigen was characterized using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) with Coomassie blue, silver and Schiff stainings. Immunoblots were done using sera of experimentally infected pigs that showed serotype specificity and cross-reactivity. Overall, the results indicate that the O-chain of lipopolysaccharides is a specific antigen that could be used in ELISA for the serodiagnosis of serotype 5 of A. pleuropneumoniae.     

Biochemical and biological studies on the lipopolysaccharide of Bacteroides nodosus

Lipopolysaccharides (LPS) were extracted from three Bacteroides nodosus isolates by the aqueous phenol method and purified by ultracentrifugation. The structure of B nodosus LPS appears to be similar to enterobacterial LPS, with the polysaccharide component joined to the lipid A moiety through an acid-labile 2-keto-3-deoxyoctonic acid (KDO) linkage. B nodosus LPS contained glucose, galactose, hexosamine, KDO and heptose and no sugars apart from ribose, which was possibly a nucleic acid contaminant, were unique to any of the isolates. Electron microscopic examination indicated a similar morphology to LPS derived from other Gram-negative bacteria. B nodosus LPS was found to exhibit biological properties characteristic of endotoxins, such as pyrogenicity, leucopenic and leucocytotic activity, production of the primary inflammatory response in rabbit skin and Shwartzman reactivity. However, the toxicity of B nodosus LPS was low.     

Biochemical characterization of an antigenic saline extract of Actinobacillus pleuropneumoniae serotype 5 and identification of a serotype-specific antigen for ELISA serodiagnosis.

A saline extract of boiled-formalinized whole cells from a local strain (81–750; Quebec, Canada) of Actinobacillus pleuropneumoniae, serotype 5b was used as an antigen in an enzyme-linked immunosorbent assay (ELISA) for serodiagnosis of swine pleuropneumonia. Characterization of this crude extract was done and proteins, neutral sugars, hexosamines, and 2-keto-3-deoxyoctonate (KDO) were evaluated. On phenol extraction of the crude extract a serotype-specific antigen of polysaccharidic nature was recovered from the aqueous phase. This antigen was characterized using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) with Coomassie blue, silver and Schiff stainings. Immunoblots were done using sera of experimentally infected pigs that showed serotype specificity and cross-reactivity. Overall, the results indicate that the O-chain of lipopolysaccharides is a specific antigen that could be used in ELISA for the serodiagnosis of serotype 5 of A. pleuropneumoniae.     

Induction of tumor necrosis factor alpha and nitric oxide in rabbits inoculated with a cyst extract of Sarcocystis cruzi.

Rabbits develop a toxic reaction similar to endotoxemia following inoculation with a Sarcocystis cruzi cyst extract. To analyze the pathophysiology of the reaction, serum tumor necrosis factor alpha (TNFalpha), nitric oxide (NO) and lipid-lipoprotein profiles were investigated in rabbits given the cyst extract and lipopolysaccharide (LPS) by subcutaneous inoculation. In animals given the cyst extract, overproduction of TNFalpha was detected, together with an increase in NO. The animals developed derangement of lipid metabolism, which was considered to have resulted from TNFalpha induction, consisting of elevated triglyceride and very low density lipoprotein levels and decreased high density lipoprotein (HDL) levels. Serum interleukin-6-like activity also increased transiently in the animals. Capability of the cyst extract to induce TNFalpha, NO and the lipid profile derangement were completely lost by boiling. In animals given LPS, TNFalpha was induced and HDL decreased moderately, without inactivation of those activities of LPS by boiling. These results indicated that S. cruzi cyst extract is a potent, but thermolabile inducer of TNFalpha and NO for rabbits. It is likely that TNFalpha and NO play important roles as mediators in the reaction associated with toxicity of the cyst extract in rabbits.     

Attempted induction of local Shwartzman reaction in the chicken

Chickens and rabbits were injected intradermally with an endotoxin, namely Escherichia coli lipopolysaccharide (LPS). Twenty-four hours later, LPS was again administered intravenously to induce a local Shwartzman reaction. A typical cutaneous inflammatory reaction developed in rabbits, but not in chickens. Even very high doses of LPS, that made the birds visibly sick, failed to elicit the reaction. The results suggest that chickens are refractory to the Shwartzman reaction. A noteworthy feature of the chickens' response to intradermal endotoxin was the formation of prominent perivascular lymphoid aggregates.     

一株犬种布鲁氏菌的分离与鉴定

对从一只流产贵宾犬全血中分离到的一株布鲁氏菌进行了形态结构、培养特性、生化特性研究以及凝集试验鉴定和多种属聚合酶链式反应(AMOS-PCR)鉴定.结果表明,分离菌为革兰氏阴性菌,在胰际琼脂培养基生长并呈典型的粗糙型布鲁氏菌菌落,菌落能被结晶紫溶液染成紫色.分离菌在琉瑾和复红培养基上生长,不产生H2S,与粗糙型布鲁氏菌阳性血清凝集,与光滑型布鲁氏菌阳性血清无凝集.用AMOS-PCR方法对分离菌进行鉴定,该分离菌具有犬种布鲁氏菌特有条带.鉴定结果表明分离菌符合犬种布鲁氏菌特性,将其命名为B.canis GB1.     

免疫亲和色谱-气相色谱/质谱法(IAC-GC/MS)检测猪肝中的沙丁胺醇与克伦特罗

制备出抗沙丁胺醇的抗血清，提取、纯化IgG制备免疫亲和色谱柱，针对沙丁胺醇与克伦特罗的动态柱容量分别为400ng／mL基质和416ng／mL基质。猪肝样品匀浆后用稀盐酸提取，经免疫亲和色谱柱纯化，再用GC／MS检测，即为IAC-GC／MS法。对沙丁胺醇的检测限为0．5ng／g，定量限为2ng／g，对克伦特罗的检测限为0．8ng／g，定量限为2．5ng／g。空白组织按照1、5、10、20ng／g的浓度添加药物，沙丁胺醇在空白肝中的添加回收率为78．4％～106．9％，克伦特罗的添加回收率为77．1％～102．9％。本研究建立的检测猪肝中沙丁胺醇与克伦特罗的IAC-GC／MS法乃国内首次报道。     

Pharmacokinetics of enrofloxacin and flunixin meglumine and interactions between both drugs after intravenous co-administration in healthy and endotoxaemic rabbits

The purpose of this study was to determine the pharmacokinetics and possible interactions of enrofloxacin (ENR) and flunixin meglumine (FM) in healthy rabbits and in rabbits where endotoxaemia had been induced by administering Escherichia coli lipopolysaccharide (LPS). Six male adult New Zealand White rabbits were used for the study. In Phase I, FM (2.2 mg/kg) and ENR (5 mg/kg) were given simultaneously as a bolus intravenous (IV) injection to each healthy rabbit. After a washout period, Phase II consisted of purified LPS administered as an IV bolus injection, then FM and ENR. LPS produced statistically significant increases in some serum biochemical concentrations. After the drugs were co-administered, the kinetic parameters of FM were not significantly different in healthy compared to endotoxaemic rabbits. It is concluded that ENR and FM could be co-administered to rabbits to treat endotoxaemia as no negative interaction was observed between the pharmacokinetics of both drugs.     

天门冬多糖对猪脾淋巴细胞体外增殖的影响

试验旨在研究不同浓度的天门冬多糖(ASP),在ConA或LPS的协同刺激下对猪脾淋巴细胞体外增殖的影响。猪脾淋巴细胞体外培养体系中加入不同浓度的天门冬多糖使其终浓度为400、200、100、50、25、12.5μg/ml,在ConA(5μg/ml)或者LPS(10μg/ml)的协同刺激作用下,细胞培养24、48、72 h时,观察猪脾淋巴细胞增殖情况。结果表明,天门冬多糖及其协同ConA或LPS能显著或极显著的促进猪脾淋巴细胞体外增殖(P<0.05或P<0.01)。     

化学发光直接竞争免疫分析法检测猪尿中莱克多巴胺残留

本试验研究建立了猪尿中莱克多巴胺（Ractopamine, RAC）残留的直接竞争化学发光免疫检测方法。合成了莱克多巴胺和辣根过氧化物酶的偶联物（RAC-HRP）,方法的检测限为0.09 ng/mL,空白猪尿中添加浓度为0.5、10和100 ng/mL RAC时,检测范围为0.3～157.0 ng/mL;回收率为76.3%～87.6%,批内变异系数为10.0%～12.2%,批间变异系数为14.2%～15.2%。     

Algae intoxication in livestock and waterfowl

Blue-green algae toxins include (1) hepatotoxic peptides that are known to be toxic to cattle, dogs, swine, waterfowl, and sometimes other species; (2) a nicotinic agonist neurotoxin that appears to be toxic to a wide range of animal species; (3) a peripheral-acting cholinesterase inhibitor that is very toxic to swine, birds, and dogs; (4) toxins that impair nervous transmission by blocking sodium channels in nerve cells; and (5) lipopolysaccharide endotoxins. This article provides current information on the mechanisms of action of the primary toxins recognized to date as well as on procedures important in the diagnosis and management of some of the more common cyanobacterial toxicoses in livestock and waterfowl.     

Postovulatory Effect of Intravenous Administration of Lipopolysaccharide (Escherichia coli, O55:B5) on the Endocrine Status of Recently Ovulated Sows

The effects of lipopolysaccharide ( Escherichia coli , O55:B5), administered 18 h after ovulation in the second oestrus after weaning on the hormonal profiles in 14 Swedish cross-bred (Landrace × Yorkshire) multiparous sows were studied. The endotoxin group (E-group) sows were administered with 300 ng/kg of lipopolysaccharide (LPS) whereas the control group (C-group) sows were administered 5 ml of saline intravenously via an indwelling jugular cannula. Blood samples for hormonal analyses were collected from all sows until slaughter. In the E-group, progesterone, cortisol and prostaglandin F_2α metabolite levels increased significantly (p < 0.05) following LPS compared with the C-group. It can be concluded from this study that apart from elevating cortisol and prostaglandin F_2α metabolite, LPS also elevates progesterone levels.     

Effect of infections with swine fever virus on immune functions. III. Antibody response to lipopolysaccharide and sheep red blood cells

In order to determine the effect of infections with low-virulent swine fever virus (SFV) on antibody responses, pigs were administered lipopolysaccharide (LPS) or sheep red blood cells (SRBC), 2 days after infection. Infected pigs showed an enhanced primary response to LPS late during infection. The secondary response to LPS seemed to be unaffected. Both the primary and secondary antibody response to SRBC appeared to be enhanced rather than depressed in infected pigs. These in vivo findings suggest that pigs infected with low-virulent SFV do not develop a depression of B lymphocyte function.     

Effects of triamcinolone acetonide, sodium hyaluronate, amikacin sulfate, and mepivacaine hydrochloride, alone and in combination, on morphology and matrix composition of lipopolysaccharide-challenged and unchallenged equine articular cartilage explants

OBJECTIVE: To evaluate the effects of triamcinolone acetonide (TA), sodium hyaluronate (HA), amikacin sulfate (AS), and mepivacaine hydrochloride (MC) on articular cartilage morphology and matrix composition in lipopolysaccharide (LPS)-challenged and unchallenged equine articular cartilage explants. Sample POPULATION: 96 articular cartilage explants from 4 femoropatellar joints of 2 adult horses. PROCEDURES: Articular cartilage explants were challenged with LPS (100 ng/mL) or unchallenged for 48 hours, then treated with TA, HA, AS, and MC alone or in combination for 96 hours or left untreated. Cartilage extracts were analyzed for glycosaminoglycan (GAG) content by dimethyl-methylene blue assay (ng/mg of dry wt). Histomorphometric quantification of total lacunae, empty lacunae, and lacunae with pyknotic nuclei was recorded for superficial, middle, and deep cartilage zones. RESULTS: LPS induced a significant increase in pyknotic nuclei and empty lacunae. Treatment with TA or HA significantly decreased empty lacunae (TA and HA), compared with groups without TA or HA, and significantly decreased empty lacunae of LPS-challenged explants, compared with untreated explants. Treatment with AS or MC significantly increased empty lacunae in unchallenged explants, and these effects were attenuated by TA. Treatment with MC significantly increased empty lacunae and pyknotic nuclei and, in combination with LPS, could not be attenuated by TA. Content of GAG did not differ between unchallenged and LPS-challenged explants or among treatments. CONCLUSIONS AND CLINICAL RELEVANCE: Treatment with TA or HA supported chondrocyte morphology in culture and protected chondrocytes from toxic effects exerted by LPS, AS, and MC.     

Effect of CsA on the Expression of IL-1β and IL-6 in Endometrial Stomas Cells Induced by LPS

The aim of this study was to investigate the effect of immunosuppressant cyclosporine A (CsA) on the expression of proinflammatory cytokines interleukin 1 beta (IL-1β) and interleukin 6 (IL-6) in LPS-induced uterine endometrial stromas cells (ESCs).After cultured and identified in vitro,the inflammation model of the ESCs of female rabbits were successfully constructed by 1 μg/mL lipopolysaccharide (LPS),and 0 μg/mL LPS was used as the control.Then the expression levels of IL-1β and IL-6 were detected after treatment with 0,50,100,200 and 500 ng/mL CsA.The results showed that LPS significantly induced the expression of IL-1β and IL-6 in ESCs (P<0.05).Although CsA had no effect on the expression of IL-1β and IL-6,but 50,100,200 and 500 ng/mL CsA extremely significantly inhibited the upregulation of IL-1β and IL-6 induced by 1 μg/mL LPS (P<0.01).It suggested that a certain dose of CsA could effectively inhibit the LPS-induced immune stress in ESCs.This study provided a basis for the feasibility of CsA treatment after the genital tract of female infected by gram-negative bacteria,but its clinical application and mechanism still need to be further studied.