抗菌剂马波沙星对家蚕细菌病的防治效果

马波沙星是一种新型的氟喹诺酮类抗菌剂,对革兰阴性菌、革兰阳性菌和支原体均有抑制或杀灭作用。通过体外抑菌试验和生物试验探究马波沙星对家蚕主要细菌病害的防治效果。马波沙星对苏芸金芽孢杆菌(Bacillus thuringiensis)、黑胸败血芽孢杆菌(Bacillus bombysepticus)、沙雷铁氏菌(俗称灵菌,Serratia marcescens)的体外最低抑菌浓度(MIC)分别为0.25 mg/L、0.50 mg/L、0.25 mg/L,最低杀菌浓度(MBC)分别为8 mg/L、16 mg/L、32 mg/L,均大于或等于盐酸环丙沙星的MIC和MBC值。以质量浓度为50 mg/L、200 mg/L的马波沙星药液给5龄起蚕添食8 h,对由苏芸金芽孢杆菌、黑胸败血芽孢杆菌感染引起的家蚕败血病的防治效率为100%;以800 mg/L马波沙星药液给5龄起蚕添食24 h或连续3 d每日给药8 h,对由灵菌感染引起的家蚕败血病的防治效率为100%,防治效果显著优于盐酸环丙沙星(P0.05)。5龄起蚕接种苏芸金芽孢杆菌3 h后添食50 mg/L马波沙星药液24 h,对家蚕败血病的防治效率为100%;5龄起蚕接种黑胸败血芽孢杆菌1 h后添食100 mg/L马波沙星药液24 h和接种3 h后添食200 mg/L马波沙星药液24 h,对家蚕败血病的防治效率均可达90.0%以上;5龄起蚕接种灵菌3 h后添食1 600 mg/L马波沙星药液24 h,对家蚕败血病的防治效率可达90.0%以上,防治效果显著优于盐酸环丙沙星(P0.05)。药物对家蚕的毒性试验表明,给3龄、4龄、5龄家蚕幼虫连续添食200 mg/L、600 mg/L、1 000 mg/L的马波沙星药液,对家蚕的生长发育和茧质无不良影响。试验结果初步显示,马波沙星对家蚕无安全风险,可以用于家蚕细菌性败血病的防治。     

盐酸左旋氧氟沙星的筛选及其对家蚕主要细菌病的防治效果!

为寻找防治家蚕细菌病的有效药剂,通过体外抑菌试验从盐酸左旋氧氟沙星、盐酸蒽诺沙星、强力霉素、硫酸新霉素、氟苯尼考5种常用兽用抗生素药剂中,筛选出对苏云金芽孢杆菌、黑胸败血菌和粘质沙雷氏菌(灵菌)抑菌效果较好的盐酸左旋氧氟沙星,并进一步研究了其对家蚕细菌病的防治效果。试验结果表明,盐酸左旋氧氟沙星对苏云金芽孢杆菌、黑胸败血菌和粘质沙雷氏菌3种病原菌引起的细菌病都有较好的防治效果,优于对照药物氟苯尼考;并且盐酸左旋氧氟沙星对家蚕生长、茧质均无不良影响(P>0.05),表明盐酸左旋氧氟沙星是防治家蚕细菌病的一种理想药剂。     

盐酸沙拉沙星胶囊对家蚕细菌性败血病的防治研究

盐酸沙拉沙星胶囊是以兽用喹诺酮类药物盐酸沙拉沙星为主要成分制成的蚕用抗菌药剂。盐酸沙拉沙星胶囊对家蚕细菌性败血病的防治效果试验表明,用100mg/L盐酸沙拉沙星药液给感染卒倒芽孢杆菌的4龄起蚕连续添食3d(第1天添食24h,第2、3天每天添食6h),对家蚕败血病的防治效果与用500mg/L盐酸诺氟沙星药液、125mg/L盐酸环丙沙星药液添食的防治效果无明显差异(P0.05);用400mg/L盐酸沙拉沙星药液给感染灵菌的4龄起蚕连续添食3d(添食方法同上),对家蚕败血病的防治效果明显优于用500mg/L盐酸诺氟沙星药液、250mg/L盐酸环丙沙星药液添食的防治效果(P0.05),与用500mg/L盐酸环丙沙星药液添食的防治效果无明显差异(P0.05)。盐酸沙拉沙星对卒倒芽孢杆菌、灵菌的最低抑菌浓度分别为1.25、5μg/mL,最低杀菌浓度分别为5、10μg/mL。分别给4龄、5龄家蚕添食400、800、1200、2000mg/L的盐酸沙拉沙星药液,对家蚕的生长发育、茧质和丝质均未见明显不良影响(t检验,P0.05),且不存在明显的剂量-反应关系。分别给5龄第4天家蚕添食剂量为5、10、20mg/kg的盐酸沙拉沙星后,药物在蚕体内吸收良好,血药浓度-时间曲线符合一级吸收的一室开放式模型。研究结果显示,盐酸沙拉沙星胶囊对卒倒芽孢杆菌或灵菌感染引发的家蚕细菌性败血病具有明显的防治效果,并且对家蚕安全无害。     

7种抗菌药物协同抗家蚕病原细菌效果

家蚕细菌病是一种可以应用药物治疗的蚕病，在养蚕生产中使用的抗菌药物种类繁多。为了合理使用药物，有效防治家蚕细菌病，采用琼脂平板滤纸片法调查盐酸环丙沙星、恩诺沙星、盐酸多西环素、硫氰酸红霉素、氯霉素、氟苯尼考和阿莫西林等7种抗菌药物对家蚕灵菌败血病病原、苏云金杆菌和葡萄球菌的体外抗菌活性，并调查抗菌药物间协同抗家蚕细菌病原的效果。结果表明，盐酸环丙沙星对家蚕病原细菌抗菌效果最佳，对灵菌败血病菌和苏云金杆菌的抑菌活性是抗菌较差药物的19倍以上；其次是恩诺沙星；其他药物的抑菌效果较差。试验验证出盐酸环丙沙星与恩诺沙星、盐酸多西环素、氟苯尼考、硫氰酸红霉素、氯霉素、阿莫西林以及恩诺沙星与硫氰酸红霉素、盐酸多西环素、氟苯尼考两两混合对家蚕灵菌败血病菌和苏云金杆菌具有协同增效作用；盐酸环丙沙星与氯霉素、恩诺沙星与氟苯尼考混合对家蚕葡萄球菌也具有增强抗菌的效果。试验结果为蚕用药物生产以及养蚕生产中合理利用药物有效防治蚕病提供指导依据。     

9种抗菌药物对禽多杀性巴氏杆菌体外抗菌活性研究

采用试管二倍稀释法，测定了9种抗菌药物对禽多杀性巴氏杆菌的体外抗菌活性（MIC和MBC）。结果表明氨苄西林、阿莫西林和诺氟沙星对禽多杀性巴氏杆菌的MIC均为0．125μg／mL，诺氟沙星MBC为0．5μg／mL，氨苄西林和阿莫西林的MBC都为1．0μg／mL。氟苯尼考、替米考星和卡那霉素对禽多杀性巴氏杆菌的MIC分别为：0．5、2和2μg／mL。     

防治家蚕细菌病药物的筛选

本试验通过药敏试验和药效对比的办法筛选出对黑胸败血杆菌、灵杆菌有抑制作用的药物。结果表明,盐酸环丙沙星、诺氟沙星、恩诺沙星、红霉素、氟苯尼考药物中,氟苯尼考对黑胸败血杆菌和灵杆菌败血菌病的治疗效果最好。     

克蚕菌的体外抗菌活性研究

以试管稀释法、活菌计数法检测了克蚕菌体外最低抑菌浓度 (MIC)及最低杀菌浓度 (MBC)等 ,结果显示克蚕菌对苏云金杆菌、卒倒杆菌、青头败血病菌、八联球菌和产气杆菌的MIC和MBC分别为 0 5 μg/mL和 8.0 μg/mL。不同细菌接种量、不同家蚕血清含量和不同pH值对克蚕菌的抗菌活性略有影响。克蚕菌具有较强的体外抗菌活性。     

三种抗菌药体外对鸡败血支原体的敏感性

本研究测定了蒽诺沙星、泰乐菌素及土霉素对鸡败血支原体（BG44T株）的体外最小抑菌浓度（MIC）及泰乐菌素与土霉素的联合药敏作用。MIC测定采用试管两倍稀释法，联合药敏采用棋盘法，重复三次试验，以平均值作为结果。蒽诺沙星、泰乐菌素及土霉素对鸡败血支原体的MIC分别为0.025μg/ml、0.00625μg/ml和0.5μg/ml。泰乐菌素与土霉素的联合药敏试验的抑菌浓度指数为0.5，合用有协同作用。     

微酸性电解水对家蚕黑胸败血芽孢杆菌的杀灭效果及机制研究

微酸性电解水作为一种安全、高效、广谱的新型消毒剂,具有制备简单、成本低、使用后无残留、对人体无毒无害等优点.研究微酸性电解水对家蚕黑胸败血芽孢杆菌的杀灭效果及其杀菌机制,为其在蚕桑生产中的应用奠定基础.体外抑菌试验结果表明,有效氯质量浓度为40 mg/L、pH5.5、氧化还原电位(ORP)为1100 mV的微酸性电解水处理5 min即可全部杀灭家蚕黑胸败血芽孢杆菌.生物学试验结果表明,该电解水对家蚕黑胸败血芽孢杆菌处理5 min后,家蚕黑胸败血芽孢杆菌的灭活率达到90％;处理15 min时,灭活率为100％.经微酸性电解水处理后,家蚕黑胸败血芽孢杆菌的外部形态发生改变,菌体膨胀、逐渐伸长,之后出现孔洞,最后菌体破裂、死亡;胞外电导率、可溶性蛋白含量和可溶性糖含量逐渐增加;菌体DNA发生降解.试验结果表明微酸性电解水主要通过破坏家蚕黑胸败血芽孢杆菌细胞外部形态,改变细胞膜通透性,导致细胞内容物外渗,DNA结构受到破坏,达到杀菌目的 .     

盐酸诺氟沙星在健康及细菌感染家蚕中的药代动力学研究

比较抗菌素盐酸诺氟沙星在健康和细菌感染家蚕间的药代动力学特征,可为临床合理用药提供科学依据。对健康及黑胸败血菌(Bacillus bombysepticus)感染家蚕幼虫用250μg/mL盐酸诺氟沙星药液处理的桑叶(剂量18mg/kg)添食,经高效液相色谱法(HPLC)检测不同时间的血浆药物浓度,并用MCP-KP药代动力学分析程序进行分析。结果表明,盐酸诺氟沙星在健康及细菌感染家蚕体内的血药浓度与时间关系均符合一级吸收一室开放模型。与健康家蚕药物代谢动力学参数相比较,盐酸诺氟沙星在细菌感染家蚕体内的药-时曲线下面积(AUC)由81.194mg/(h.L)降为66.105mg/(h.L),吸收半衰期(T1/2Ka)由1.252h延长为1.591h,分布半衰期(T1/2α)由2.673h缩短为1.981h,消除半衰期(T1/2β)由9.298h缩短为5.338h,说明细菌感染使盐酸诺氟沙星在家蚕体内的吸收能力下降,吸收减慢,分布和消除加快。     

蚕用抗菌药物亚迪丰的抗菌活性和药物动力学研究

采取试管稀释法进行体外抗菌试验,证明蚕用抗菌药物亚迪丰对苏云金杆菌、卒倒菌、短小芽孢杆菌、青头败血病菌、灵菌、八联球菌和产气杆菌等有明显的抑制作用,对上述细菌的M IC为0.5μg/mL、MBC为1.0~2.0μg/mL。体内抗菌试验测得亚迪丰对卒倒菌感染家蚕有良好的保护作用,其ED50为9.82 mg/kg;对灵菌的ED50为139.33 mg/kg。5龄家蚕食下亚迪丰后血清药物浓度-时间数据符合一级吸收动力学和单室模型特征。     

牛至油博落回口服液的研制及体外抑菌活性测定

【目的】 研制牛至油博落回口服液, 并测定其体外抑菌活性及其主要成分的联合抑菌效果, 为临床用药提供理论依据。【方法】 通过预试验和Box-Behnken响应面法优化处方; 采用高效液相色谱法测定口服液主要成分含量; 采用滤纸片法测定口服液对大肠杆菌、沙门氏菌、金黄色葡萄球菌和粪链球菌的抑菌圈直径; 采用试管二倍稀释法测定口服液、5%牛至油溶液及1%博落回溶液对4种细菌的最小抑菌浓度(MIC)和最小杀菌浓度(MBC); 采用微量棋盘稀释法对5%牛至油溶液与1%博落回溶液进行体外联合药敏试验。【结果】 牛至油博落回口服液最优配方为: 5%牛至油, 1%博落回提取物, 25%增溶剂聚氧乙烯(40)氢化蓖麻油, 0.02%抗氧化剂2, 6-二叔丁基对甲酚(BHT), 余量为水。口服液中香芹酚的含量为42.59 mg/mL, 血根碱含量为6.51 mg/mL。口服液对4种菌的抑菌圈直径分别为16.9、16.4、23.7和17.0 mm, MIC分别为3.125、3.125、1.5625和1.5625 μL/mL, MBC分别为12.5、6.25、3.125和3.125 μL/mL; 5%牛至油溶液对4种菌的MIC分别为25、12.5、6.25和100 μL/mL, MBC分别为100、50、25和>200 μL/mL; 1%博落回溶液对4种菌的MIC分别为6.25、12.5、3.125和6.25 μL/mL, MBC分别为50、25、6.25和25 μL/mL。联合药敏试验表明, 二者联合用药对大肠杆菌、沙门氏菌起相加作用, 对金黄色葡萄球菌无作用, 对粪链球菌为协同作用。【结论】 试验制备了牛至油博落回口服溶液剂, 该制剂对大肠杆菌、沙门氏菌、金黄色葡萄球菌和粪链球菌具有良好抑制作用。     

桑疫病病原菌的室内药物敏感试验

基于为控制桑疫病的危害提供高效防治药剂的目的,采用培养皿圆滤纸片法和试管两倍稀释法,进行了19种药物对桑疫病病原菌(Pseudomonassyringaepv.mori)的室内抑菌效果测定。筛选出环丙沙星、恩诺沙星、氟哌酸、吡哌酸、萘啶酸、新霉素、链霉素、阿奇霉素、DT-301、苯扎氯铵等10种敏感药物,其中桑疫病病原菌对环丙沙星最敏感,对链霉素较敏感,最低抑菌浓度(MIC)分别为0.125μg/mL和0.5μg/mL。     

In vitro evaluation of various quinolone antibacterial agents against veterinary mycoplasmas and porcine respiratory bacterial pathogens

The in vitro activities of 12 quinolones and four antibiotics were determined against 15 veterinary mycoplasmal species and four species of bacteria commonly involved in respiratory infections in pigs. The newer quinolones were markedly more active in vitro against a wide range of mycoplasmas than nalidixic acid and the earlier quinolones. Against Mycoplasma hyopneumoniae ciprofloxacin was the most active quinolone with a geometric mean minimal inhibitory concentration (MIC) against 16 strains of 0.01 microgram ml-1 compared with 0.04 microgram ml-1 for tiamulin, 0.06 microgram ml-1 for tylosin, 0.17 microgram ml-1 for oxytetracycline and 0.23 microgram ml-1 for gentamicin. M hyosynoviae was less sensitive to the quinolones with mean MICs of 0.6 microgram ml-1 for ofloxacin and 0.7 microgram ml-1 for ciprofloxacin compared with 0.034 microgram ml-1, or less, for tiamulin. Norfloxacin and its 6-chloro analogue were both mycoplasmacidal in vitro at five or 10 times their MICs against M hyopneumoniae UCD4. Tiamulin was mycoplasmastatic. The quinolones were also active against porcine Bordetella bronchiseptica and Pasteurella multocida strains and Haemophilus species. Ciprofloxacin was the most active quinolone with mean MICs of 0.58 microgram ml-1 against B bronchiseptica (nine strains), 0.026 microgram ml-1 against P multocida (five strains) and 0.01 microgram ml-1, or less, against Haemophilus pleuropneumoniae (nine strains) and H parasuis (two strains) compared with mean MICs of from 0.5 microgram ml-1 to 64 micrograms ml-1, or more, for the antibiotics. This combination of excellent mycoplasmacidal activity against M hyopneumoniae and good antibacterial activity, suggests that the quinolones have great potential for treating respiratory infections in pigs, including enzootic pneumonia.     

In vitro antimicrobial efficacy of β‐defensin 3 against Staphylococcus pseudintermedius isolates from healthy and atopic canine skin

β‐Defensins (BDs) are highly conserved antimicrobial peptides important in innate defence against bacteria. β‐Defensin 3 has a specific role in protecting the skin. This study quantified the minimal inhibitory concentration (MIC) of human (h)BD3 against Staphylococcus pseudintermedius isolates from atopic and healthy dogs. Single colony isolates (1 × 10⁵ colony‐forming units/mL log phase) were cultured with doubling dilutions of hBD3 in sodium phosphate buffer from 0.8 to 50 μg/mL at 37 °C for 2 h, before adding 100 μL of tryptone soy broth and incubating for a further 20 h. Bacterial growth was assessed as the mean optical density at 540 nm corrected for background. The median MIC was 12.5 μg hBD3/mL (range 3.125–25 μg/mL; n = 22). Forty‐five percent of the isolates were inhibited at ≤6.25 μg hBD3/mL, and 90% were inhibited at ≤12.5 μg hBD3/mL. Bacterial growth was not inhibited at ≤1.6 μg hBD3/mL. There were no significant differences in the inhibition by hBD3 of isolates from atopic (median MIC 12.5 μg/mL, range 6.25–25 μg/mL, n = 14) and healthy dogs (median MIC 9.4 μg/mL, range 3.125–12.5 μg/mL, n = 8); from noninfected colonized sites (median MIC 12.5 μg/mL, range 3.125–25 μg/mL, n = 16) and infected lesions (median MIC 9.4 μg/mL, range 6.25–12.5 μg/mL, n = 6); or between sample sites (nose median MIC 12.5 μg/mL, range 6.25–25 μg/mL, n = 5; perineum median MIC 12.5 μg/mL, range 3.125–25 μg/mL, n = 7; ear median MIC 6.25 μg/mL, range 6.25–12.5 μg/mL, n = 4; lesions median MIC 9.4 μg/mL, range 6.25–12.5 μg/mL, n = 6). In conclusion, hBD3 inhibited the growth of canine S. pseudintermedius isolates in vitro irrespective of origin.     

Comparative quantification of the in vitro activity of veterinary fluoroquinolones

The aim of this study was to compare the in vitro antimicrobial activity of the veterinary fluoroquinolones against a panel of recently isolated porcine and bovine bacterial pathogens. The study used enrofloxacin as a benchmark against which other agents were compared, being the most common fluoroquinolone used in treatment of bovine and porcine infections. The activity of ciprofloxacin was also assessed as it is the main metabolite of enrofloxacin in cattle. Enrofloxacin and ciprofloxacin generally showed higher antibacterial activity, in terms of MIC(50) values, for most pathogen species when compared with marbofloxacin, difloxacin, danofloxacin and norfloxacin. Ciprofloxacin showed significantly greater in vitro antibacterial activity than enrofloxacin against M. haemolytica, P. multocida and E. coli, whereas enrofloxacin showed greater activity than ciprofloxacin against S. aureus. Marbofloxacin was significantly more active than enrofloxacin against M. haemolytica, E. coli and B. bronchiseptica but less active against P. multocida, S. aureus, coagulase negative Staphylococci, S. dysgalactiae, S. uberis, A. pleuropneumoniae and S. suis. Danofloxacin was significantly less active than enrofloxacin against P. multocida, E. coli, S. uberis, A. pleuropneumoniae and S. suis. Enrofloxacin and its metabolite ciprofloxacin showed the highest in vitro activities against most bovine pathogens tested and the porcine pathogens also showed a high degree of sensitivity to enrofloxacin. These data facilitate further pharmacokinetic/pharmacodynamic comparison of fluoroquinolones currently used in veterinary medicine.     

鸡源致病性大肠杆菌药物耐受性与药物剂量相关性的研究

利用从山东省15个地区分离纯化并鉴定了的47株对庆大霉素、硫酸丁胺卡那霉素、氯霉素等药物中的一种或几种耐药的大肠杆菌菌株,进行了对这几种药物不同剂量耐药性的研究,以探讨大肠杆菌的药物耐受性与药物剂量的相关性,结果表明大多数没有耐药性的菌株,抑菌圈直径与药物浓度呈正相关;大部分已有耐药性的菌株,抑菌圈直径与药物浓度无相关性。     

大通量的抗生素药敏检测盒的设计及应用

基于琼脂稀释法,设计制作了96点阵抗生素药敏检测盒。以NCCLS（2007）抗生素最低抑菌浓度(minimal inhibitory concentration,MIC)微量稀释法为对照,测定了分离自规模化猪场饲养员和幼儿园、中学学生的98株大肠杆菌对恩诺沙星、环丙沙星、诺氟沙星和中药三黄汤的药物敏感性。结果表明,两种方法测定的最低杀菌浓度(minimal bactericidal concentration,MBC)、MIC都表现高度对称,其差值的平均值都在一倍稀释度内,在差值0.5 μg/mL范围内都达到90%以上的符合。MBC与MIC高度相关,r=0.94~0.99。这些指标说明两种方法测定的MBC与MIC平行性好。以总体的抗生素敏感性频率比较,两种方法测定值也很相近,符合率为93.93%。本检测盒还可以准确测定中药三黄汤对大肠杆菌的MIC（125～500 mg/mL）。96点阵抗生素药敏检测盒是适合于实验室进行大规模抗药性监测的新工具,具有简易、准确、快速、大通量、节约的优点。配合96孔培养板,一次可以测定96株病原菌对一种抗生素或中药的敏感性。