盐酸沙拉沙星对禽猪致病菌的体外抗菌作用

本试验选用15株禽常见致病菌，用两倍试管稀释法对盐酸沙拉沙星进行最小抑菌浓度（MIC）测定，以给临床用药提供依据。结果表明沙拉沙星的抗菌谱广、抗菌活性强，对革兰氏阳性菌、阴性菌均有抑制作用，其中对革兰氏阴性菌尤其是对鸡大肠杆菌、鸡白痢沙门氏菌的作用较强。     

乙酰甲喹对畜禽常见致病菌的体外抗菌活性研究

利用纸片扩散法和试管二倍稀释法验证了乙酰甲喹注射液对畜禽常见致病菌的体外抗菌效果。纸片扩散法结果表明,乙酰甲喹注射液对禽大肠杆菌、猪大肠杆菌、沙门氏菌、鸡巴氏杆菌、链球菌、绿脓杆菌高度敏感,对金黄色葡萄球菌中度敏感。试管二倍稀释法结果表明,乙酰甲喹注射液对畜禽主要致病菌的最小抑菌浓度(MIC)为0.004～0.036μL/mL,最小杀菌浓度为(MBC)为0.009～0.036μL/mL。该研究结果表明,乙酰甲喹注射液对常见的病原菌有较好的抗菌效果,适合临床使用。     

植物提取物对犊牛致病菌的体外抑菌效果研究

犊牛健康对奶牛养殖业发展和经济效益提升至关重要。植物提取物作为饲料添加剂具有促生长、抑菌和提高免疫力的作用,改善动物的健康。试验探究了黄酮类、生物碱类、精油、苷类、有机酸植物提取物对犊牛腹泻分离菌的体外抑菌效果。结果表明：(1)茶多酚对牛大肠杆菌、牛大肠杆菌K99、牛沙门氏菌和CVCC215、肠炎沙门氏菌的最小抑菌浓度（MIC）均为1 mg/mL;盐酸小檗碱对牛大肠杆菌、牛大肠杆菌K99和CVCC215的MIC分别为16、16 mg/mL和1 mg/mL;绿原酸对牛大肠杆菌、牛大肠杆菌K99和CVCC215的MIC均为16 mg/mL,对牛沙门氏菌和肠炎沙门氏菌的MIC均为32 mg/mL;(2)茶多酚对牛大肠杆菌、牛大肠杆菌K99、牛沙门氏菌和CVCC215、肠炎沙门氏菌的最小杀菌浓度（MBC）分别为1、1、2 mg/mL和2、2 mg/mL;盐酸小檗碱对牛大肠杆菌、牛大肠杆菌K99和CVCC215的MBC分别为16、16 mg/mL和2 mg/mL;绿原酸对牛大肠杆菌、牛大肠杆菌K99、牛沙门氏菌和CVCC215、肠炎沙门氏菌的MBC均为32 mg/mL;(3)茶多酚和盐酸小檗碱联...     

植物提取物及其复合物对鸡源致病菌的体外抑菌作用

本研究选取10种具有较强抑菌作用的植物提取物,研究其对鸡源致病菌(鸡大肠杆菌和鸡沙门氏菌)的体外抑菌作用,并分别筛选出对2种致病菌有较强抑菌作用的3种植物提取物,将其按不同比例复配,以获得抑菌效果更强的复合植物提取物。本研究分为2个试验。试验1:共设11个组,分别为百里香精油、牛至精油、肉桂精油、大蒜油、黄芩黄酮、竹叶黄酮、黄芪多糖、小檗碱、苦参碱和绿原酸和金霉素组(阳性对照组),每组6个重复,采用牛津杯法测定植物提取物对大肠杆菌和沙门氏菌的抑菌作用。试验2:根据试验1的结果,选取对大肠杆菌抑菌效果较好的肉桂精油、苦参碱和绿原酸3种植物提取物,分别按照不同浓度比例进行两两和3种植物提取物复配,用牛津杯法测定复合物对大肠杆菌的抑菌作用,同时分别设相应浓度的3种单一植物提取物为对照组,共20个组,每组6个重复;选取对沙门氏菌抑菌效果较好的竹叶黄酮、黄芩黄酮和肉桂精油3种植物提取物,用牛津杯法测定不同浓度比例的复合物和相应浓度的单一植物提取物(对照组)对沙门氏菌的抑菌作用,共17个组,每组6个重复;根据以上结果,研究了竹叶黄酮和肉桂精油按不同浓度比例复配对沙门氏菌的抑菌作用,以筛选最佳复配比例,共15个组,每组6个重复。结果表明:5种植物提取物对大肠杆菌有抑菌作用,其抑菌作用从大到小依次为肉桂精油、苦参碱、绿原酸、百里香精油、牛至精油;8种植物提取物对沙门氏菌有抑菌作用,其抑菌作用从大到小依次为竹叶黄酮、黄芩黄酮、肉桂精油、苦参碱、绿原酸、牛至精油、百里香精油、大蒜油。与肉桂精油对照组相比,肉桂精油、苦参碱和绿原酸两两或3种植物提取物复配不能显著增强对大肠杆菌的抑菌作用(P0.05);竹叶黄酮和肉桂精油复配可显著增强对沙门氏菌的抑菌作用(P0.05),且在浓度比例为25∶150(1∶6)时抑菌作用达到最大。由此可见,10种植物提取物中,对大肠杆菌抑菌效果较好的3种植物提取物为肉桂精油、苦参碱和绿原酸,但这3种植物提取物复合物的抑菌作用并不大于单一肉桂精油;对沙门氏菌抑菌效果较好的3种植物提取物为竹叶黄酮、黄芩黄酮和肉桂精油,竹叶黄酮和肉桂精油复配增强了抑菌效果,且复配比例为1∶6时对沙门氏菌的抑菌作用最大。     

3种中药提取物对皮肤癣菌的体外联合药敏试验

研究苦参、白鲜皮和土荆皮提取物在石膏样小孢子菌、犬小孢子菌、须癣毛癣菌3株皮肤癣菌体外联合药敏试验中的相互作用,为临床用药提供参考依据。采用棋盘微量稀释法测量3种中药提取物对皮肤癣菌的联合抑菌指数(fractional in-hibitory concentration index,FICI)对其联用效果进行评价。结果发现,苦参醇提物与白鲜皮醇提物两者联合应用,对3株皮肤癣菌FICI值分别为1,0.75,1,FICI值均≤1,对3株真菌的抑制效果呈相加作用;土荆皮醇提物与苦参醇提物、白鲜皮醇提物联合应用,FICI值均≥2,对3株真菌的抑制效果呈无关或拮抗作用。     

常用抗菌药物对东北地区猪源链球菌的体外抗菌活性研究

采用微量稀释法(27种药物)和琼脂扩散法(7类药物)分别对临床分离的101株猪源链球菌进行了体外耐药性研究。以美国临床检验标准委员会(CLSI/NCCLS)的临界浓度和抑菌圈直径做为判断标准,判定了其对27种药物的耐药性和7类药物的耐药谱。结果表明,临床分离的菌株以耐药菌为主,且100%的菌株呈多重耐药;对头孢菌素类(100%)、磺胺类药物(96%～100%)、大环内酯类(97%～99%)、四环素类(98%)、青霉素类(94%～97%)耐药性最为严重,氟喹诺酮类药物(48%～91%)耐药性次之,共有25种不同的耐药谱型。结果表明,在东北地区分离到的猪源链球菌以多重耐药为主。     

中草药对奶牛乳房炎致病菌的体外抑菌试验

奶牛乳房炎是影响奶牛业经济效益的重要疾病。对于乳房炎的治疗，一般都是采用抗生素等药物，但随着抗生素长期大剂量的广泛使用，细菌抗药性和乳中抗生素残留问题被普遍关注。另外奶牛乳腺炎多表现为炎症性疾病而非感染性疾病。因此，在治疗时不仅应注意杀菌更应注重促进炎症的消散。中草药是纯天然物质，具有抗菌、消炎、细菌不易产生耐药性、低毒等特点，具有抗生素无法比拟的优点。所以应用中草药替代抗生素防治奶牛乳腺炎，已日益为国内外学者所关注。笔者采用试管二倍稀释法，对中草药的体外抗菌活性进行了定量分析，旨在为研制防治奶牛乳腺炎中草药制剂的科学组方提供理论依据。     

火绒草的抗菌活性研究

采用试管稀释法，分别测定了火绒草水煎液、水提醇沉液、醇提物、醇提石油醚部分、醇提乙酸乙酯部分、醇提正丁醇部分、醇提水溶部分等7种提取物时大肠杆菌C83882、大肠杆菌C83803、大肠杆菌C83814、沙门氏菌C79-20、金黄色葡萄球菌Newbould S-305、金黄色葡萄球菌临床分离株等6株病原菌的最低抑菌浓度（M1C）和最低杀菌浓度（MBC）。试验结果表明，火绒草醇提物及其石油醚部分和乙酸乙酯部分时两种金黄色葡萄球菌具有较强的抑制作用，其M1C为0．14mg／ml生药浓度，MBC为0．27mg／ml生药浓度，而其它部分时金黄色葡萄球菌的抑制作用较弱。火绒草醇提正丁醇部分和水溶部分时3株大肠杆菌和1株沙门氏菌具有较强的抑制作用，其MIC为2．70mg／ml生药浓度，MBC为2．70mg／ml生药浓度．显示了较强的抗菌活性。     

15种中药对猪大肠杆菌的体外抑菌试验

为了探讨黄连等15种中草药对猪大肠杆菌的体外抑菌作用,试验采用琼脂扩散法和微量二倍稀释法应用15种中草药水提取物对猪大肠杆菌进行体外抑菌试验,测定抑菌圈直径和最小抑菌浓度(MIC)。结果表明:黄连、大黄均对大肠杆菌O101呈高度敏感,抑菌圈直径分别为20.8,20.3 mm,其MIC值为7.813 mg/m L,抑菌效果最好;黄芩、黄柏、金银花呈中度敏感,其MIC值为31.25 mg/m L;而苦参、马齿苋、败酱草等不敏感,其MIC值为500 mg/m L,抑菌效果差。     

植物提取物对猪肠道健康的影响

抗生素被禁用后,猪肠道健康问题是养猪业面临的一大难题.植物提取物是一种植物源添加剂成品,含有多种活性成分和营养成分,具有无毒副作用、低残留和不易产生耐药性等特点,是抗生素的理想替代品.文章对常见的植物提取物进行简要概述,重点综述不同种类植物提取物对猪肠道屏障和肠道微生物的影响,以期为今后合理使用植物提取物改善猪肠道健康...     

Antibacterial activity of cefquinome against equine bacterial pathogens

Cefquinome is known for its use as an antibacterial drug in cattle and pigs. The objective of this study was to evaluate the antibacterial activity of cefquinome against equine pathogenic bacteria. The minimum inhibitory concentration (MIC) of cefquinome was determined for a total of 205 strains, which had recently been isolated in Europe from diseased horses (respiratory infection, foal septicaemia). The bactericidal activity was tested against 19 strains using the time killing method. The post-antibiotic effect (PAE) and post-antibiotic sub-MIC effect (PA SME) were determined against 12 strains. Cefquinome showed high activity against Actinobacillus equuli and streptococci (MIC(90) of 0.016 and 0.032microg/mL), Enterobacteriaceae (MIC(90)=0.125microg/mL) and staphylococci (MIC(90)=0.5microg/mL). The activity was limited against Rhodococcus spp. and Pseudomonas spp. Cefquinome was shown to be a time dependent bactericidal antibiotic against the target pathogens, killing occurring at a concentration close to the MIC. A PAE of 0.5-10h was calculated against streptococci whereas no PAE was observed for Escherichia coli. A longer PA SME was determined for streptococci (3.3 to >24h with a killing effect) and E. coli (0.5-13.9h). Cefquinome was shown to have a broad spectrum of activity which covers many equine pathogens.     

Antibacterial effect of bovine lactoferrin against udder pathogens

The antibacterial effect of lactoferrin (Lf) was tested on isolates of Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and coagulase-negative staphylococci (CNS) as well as on Pseudomonas aeruginosa (P. aeruginosa) and Klebsiella pneumoniae (K. pneumoniae), originally isolated from bovine mastitis. Concentrations of Lf used were 0.67 mg/ml, 1.67 mg/ml, and 2.67 mg/ml. Growth of udder pathogens was monitored by turbidometry either in broth culture or in whey prepared from normal milk. We focused on 3 different growth variables: lag time, slope, and maximum absorbance of bacterial growth curves. Growth inhibition was seen in the broth but hardly at all in whey. The isolates of E. coli and CNS did not grow sufficiently well in whey to draw any conclusions. The most effective inhibitory activity of Lf was seen against E. coli and P. aeruginosa. All 5 E. coil isolates had similar growth patterns. Inhibition of growth by Lf was concentration-dependent. The concentration of 0.67 mg/ml in broth and whey was generally too low for a significant inhibitory effect.     

5株抗常见动物病原菌的优良拮抗放线菌的分类鉴定

为寻找新的抗菌微生物,本研究从西北部分地区盐渍土中分离到5株具有拮抗作用的放线菌1202、02-F-17、66J03、3501及3010,其代谢产物对引起鸡大肠杆菌病的大肠埃希氏杆菌(Escherichia coli)和引起牛隐性乳房炎的无乳链球菌(Streptococcus agalactiae)等多种动物病原菌均有较强的抑菌作用.通过对其进行形态学特征、生理生化特性、细胞壁化学组分以及16S rDNA序列等多相分类研究,初步确定其分类地位分别为:5株菌均属链霉菌,其中1202与戈壁三素链霉菌(Streptomyces gobitricini)最接近,02-F-17与晶体链霉菌(Streptomyces cavis-cables)相近,66J03与易变链霉菌(Streptomyces mumbilis)相近,3501最接近红淡紫灰链霉菌(Streptomycesrubrolavendulae),3010与比基尼链霉菌(Streptomyces bikiniensi)相近.     

Bacteriophages as antimicrobial agents against major pathogens in swine: a review

In recent years, the development of antibiotic resistant bacteria has become a global concern which has prompted research into the development of alternative disease control strategies for the swine industry. Bacteriophages (viruses that infect bacteria) offer the prospect of a sustainable alternative approach against bacterial pathogens with the flexibility of being applied therapeutically or for biological control purposes. This paper reviews the use of phages as an antimicrobial strategy for controlling critical pathogens including Salmonella and Escherichia coli with an emphasis on the application of phages for improving performance and nutrient digestibility in swine operations as well as in controlling zoonotic human diseases by reducing the bacterial load spread from pork products to humans through the meat.     

Bacteriophages as antimicrobial agents against major pathogens in swine:a review

In recent years,the development of antibiotic resistant bacteria has become a global concern which has prompted research into the development of alternative disease control strategies for the swine industry.Bacteriophages(viruses that infect bacteria) offer the prospect of a sustainable alternative approach against bacterial pathogens with the flexibility of being applied therapeutically or for biological control purposes.This paper reviews the use of phages as an antimicrobial strategy for controlling critical pathogens including Salmonella and Escherichia coll with an emphasis on the application of phages for improving performance and nutrient digestibility in swine operations as well as in controlling zoonotic human diseases by reducing the bacterial load spread from pork products to humans through the meat.     

天祝天然草地3种有毒植物提取物对粘虫的生物活性

测定了3种有毒植物露蕊乌头,铁棒槌和马先蒿的4种溶剂的提取物对粘虫的杀虫活性。结果表明：露蕊乌头甲醇、乙醇提取物对粘虫均具有一定的触杀活性,LC50分别为3．63、5．79g／L;露蕊乌头甲醇提取物,马先蒿丙酮提取物和铁棒槌甲醇提取物对粘虫的胃毒活性表现较强,杀虫活性LC50分别为2．13,2．82和3．22g／L,马先蒿和铁棒槌的石油醚提取物对粘虫无胃毒活性。3种植物的4种溶剂的提取物对粘虫均表现出一定的拒食活性,其中甲醇提取物的拒食活性都较高,露蕊乌头甲醇提取物对粘虫的拒食活性明显高于其他提取物,当质量浓度达到0．2g／mL时,拒食率为97．6％。而3种植物石油醚提取物的拒食活性均较差。     

Efficacy of anthelmintic properties of medicinal plant extracts against Haemonchus contortus

The development of anthelmintic resistance has made the search for alternatives to control gastrointestinal nematodes of small ruminants imperative. Among these alternatives are several medicinal plants traditionally used as anthelmintics. This present work evaluated the efficacy of ethyl acetate, acetone, and methanol dried leaf and seed extracts of five medicinal plants were tested in vitro ovicidal and larvicidal activities on Haemonchus contortus. The in vitro assay was based on egg hatch assay (EHA) and larval development assay (LDA), all plant extracts were evaluated at five concentrations 50, 25, 12.5, 6.25 and 3.13 mg/ml. The leaf and seed ethyl acetate, acetone and methanol of Annona squamosa, Eclipta prostrata, Solanum torvum, Terminalia chebula, and Catharanthus roseus extracts were showed complete inhibition (100%) at the maximum concentration tested (50 mg/ml). The overall findings of the present study have shown that our experimental plant extracts contain possible anthelmintic compounds.     

Efficacy of anthelmintic properties of medicinal plant extracts against Haemonchus contortus

The development of anthelmintic resistance has made the search for alternatives to control gastrointestinal nematodes of small ruminants imperative. Among these alternatives are several medicinal plants traditionally used as anthelmintics. This present work evaluated the efficacy of ethyl acetate, acetone, and methanol dried leaf and seed extracts of five medicinal plants were tested in vitro ovicidal and larvicidal activities on Haemonchus contortus. The in vitro assay was based on egg hatch assay (EHA) and larval development assay (LDA), all plant extracts were evaluated at five concentrations 50, 25, 12.5, 6.25 and 3.13 mg/ml. The leaf and seed ethyl acetate, acetone and methanol of Annona squamosa, Eclipta prostrata, Solanum torvum, Terminalia chebula, and Catharanthus roseus extracts were showed complete inhibition (100%) at the maximum concentration tested (50 mg/ml). The overall findings of the present study have shown that our experimental plant extracts contain possible anthelmintic compounds.     

The anthelmintic effects of five plant extracts on the viability of Parascaris equorum larvae

Ascariasis is a very common parasitic disease in equids, especially in young horses. Despite the use of anthelmintic drugs, resistance has been frequently reported in populations of Parascaris equorum. As a result, herbal preparations are proposed for current control strategies. In this study, a modified method was used for hatching the eggs of P. equorum. After hatching, the effects of methanolic extract of Artemisia dracunculus, Eucalyptus camadulensis, Mentha pulegium, Zataria multiflora and Allium sativum (garlic) were investigated on the recovered larvae. For each extract, the anthelmintic effects of different concentrations (50, 75, 100 and 125 mg/mL) were evaluated at 0, 10, 20, 30 and 40 min after the challenge. The results showed that our modifications to the older method could enhance the hatching rate for the eggs of P. equorum (to an average of 98%). Potassium dichromate was also demonstrated in this study to be a favourable medium during embryonation. In addition, all the concentrations of A. dracunculus and M. pulegium and higher levels (≥100 mg/mL concentrations) of Z. multiflora extracts had significant lethal effects on larvae from the first to the fourth 10 min of the experiment. In contrast, E. camadulensis and A. sativum had not marked effects on larvae viability at any time of the challenge. In conclusion, our data suggest that A. dracunculus, M. pulegium and Z. multiflora have potential to be used as anthelmintic for the control of ascariasis in equid host; however, these effects remain to be confirmed through in vivo studies.