大环内酯类抗生素对畜禽病原菌体外抗菌敏感性试验研究

针对兽医临床的细菌耐药现象,为指导临床合理用药,采用微量肉汤稀释法研究了三代大环内酯类抗生素泰乐菌素、替米考星和泰地罗新对兽医临床常见的15种共74株病原菌的体外抑菌效果。结果显示:对于革兰阳性菌,泰乐菌素和替米考星对乳房炎常见的金黄色葡萄球菌、猪链球菌、无乳链球菌、停乳链球菌均有较强的抑菌活性,优于泰地罗新;泰地罗新对肺炎链球菌抑菌效果较强。对于革兰阴性菌,如支气管败血波氏杆菌、溶血性曼氏杆菌、胸膜肺炎放线杆菌、副猪嗜血杆菌等致病菌,替米考星的抑菌效果比泰乐菌素强1～64倍,泰地罗新比替米考星强2～32倍。对引起肠道感染的大肠杆菌,泰地罗新亦表现出很好的抑菌活性,效果优于泰乐菌素和替米考星。本试验为畜禽细菌性疾病的防控以及大环内酯类抗菌药物的合理使用提供了基础数据。     

替米考星对畜禽常见病原菌体外抑菌活性的研究

采用试管2倍稀释法对国产替米考星与头孢唑林钠进行了畜禽常见的18种病原菌体外抑菌活性比较试验.结果表明,替米考星对革兰氏阳性茵及某些阴性茵、鸡败血支原体等均有良好的抑制作用,对部分病原茵如对李氏杆菌、禽巴氏杆茵、猪丹毒杆菌、金黄色葡萄球菌、肺炎链球菌、支气管炎博德特氏茵、猪胸膜肺炎放线杆菌、副溶血嗜血杆菌、鸡败血支原体等高度敏感,表现为具有比头孢唑林钠更强的抑菌活性,但对部分肠道致病菌如大肠杆菌、绿脓杆菌、沙门氏茵等表现为中敏或抗药,抑茵效果与头孢唑林钠相当或较差.     

替米考星对奶牛乳房炎常见病原菌体外抑菌活性的试验研究

替米考星(tilmicosin)是一种由泰乐菌素半合成的大环内酯类畜禽专用抗生素。据研究资料报道，替米考星对革兰氏阳性菌及某些阴性菌、霉形体、螺旋体等均有良好的抑制作用，对胸膜肺炎放线杆菌、巴氏杆菌及霉形体具有比泰乐菌素更强的抗菌活性。由于其具有特殊的抗菌活性和药动学特征，     

替米考星在兽医临床上应用的研究概况

替米考星（Tilmicosin）是一种较新的由泰乐菌素半合成的大环内酯类畜禽专用抗生素，８０年代由英国Elanco动物保健品公司开发成功。替米考星由于其特殊的抗菌活性和药动学特征已被批准临床用于牛、山羊、绵羊、奶牛、猪、鸡等动物感染性疾病，特别是畜禽呼吸道疾病，如家畜放线杆菌性胸膜肺炎、巴氏杆菌病和鸡霉形体病等和泌乳动物乳房炎的治疗。为了解替米考星及其应用，现将有关抗菌活性、药动学、药效学、毒理学与临床应用等方面的研究分别概述如下。１抗菌活性替米考星具有同泰乐菌素相似的广谱抗菌活性，对革兰氏阳性菌和某些革兰氏…     

磷酸替米考星

替米考星(Tilmicosin)是一种由泰乐菌素半合成的大环内酯类抗生素。【药理】　药效学　抗菌作用与泰乐菌素相似,主要抗革兰氏阳性菌,对少数革兰氏阴性菌和支原体也有效。其对胸膜肺炎放线杆菌、巴斯德氏菌及畜禽支原体的活性比泰乐菌素强。据报道有95%的溶血性巴斯德氏菌菌株对本品敏感。本品对以下病原微生物的MIC(μg/mL)分别为:溶血性巴斯德氏菌3.12,多杀性巴斯德氏菌6.25,昏睡嗜血杆菌6.25,牛鼻支原体0.024,牛眼支原体0.048,鸡败血支原体0.0025～0.1,鸡滑液支原体0.0060.025。药动学　内服或皮下注射本品后吸收快,组织穿透力强,分…     

几种动物病原菌对替米考星耐药性的体外诱导

在测定替米考星对鸡毒支原体、多杀巴氏杆菌和猪胸膜肺炎放线杆菌的最小抑菌浓度基础上,采用药物浓度递增法体外诱导3种病原菌对替米考星的耐药性。结果鸡毒支原体经9次传代对替米考星产生了高水平耐药,多杀巴氏杆菌经7~9次传代对替米考星产生了高水平耐药,猪胸膜肺炎放线杆菌经14次传代对替米考星的耐受浓度未发生明显变化;鸡毒支原体和多杀巴氏杆菌替米考星诱导耐药株对红霉素、阿奇霉素、泰乐菌素、吉他霉素和林可霉素表现交叉耐药。研究结果提示,替米考星较易诱导鸡毒支原体和多杀巴氏杆菌产生耐药性,兽医临床应合理应用。     

替米考星饮水剂治疗人工感染禽巴氏杆菌试验

替米考星是泰乐菌素的合成衍生物，具有其类似的分子结构和抗菌谱，但对某些病原菌的抗菌活性比泰乐菌素更高，如鸡支原体，巴氏杆菌等。替米考星由于具有非常高的抗菌活性，在鸡上作为饮水剂预防和治疗呼吸道感染疾病，具有使用剂量比泰乐菌素低得多的优势。近年来国内多家药厂已开始研制并生产出替米考星，     

替米考星在兽医临床上应用的研究概况

替米考星 (Tilm icosin)是一种较新的由泰乐菌素半合成的大环内酯类畜禽专用抗生素 ,八十年代由英国 Elanco动物保健品公司开发成功。由于其特殊的抗菌活性和药动学特征 ,该药已被批准临床用于牛、山羊、绵羊、奶牛、猪、鸡等动物感染性疾病的防治 ,特别是畜禽呼吸道疾病 ,如家畜放线杆菌性胸膜肺炎、巴氏杆菌病和鸡霉形体病等及泌乳动物乳房炎的治疗。为了解替米考星及其应用 ,现将有关其抗菌活性、药动学、药效学、毒理学与临床应用等方面的研究分别概述如下。1　抗菌活性替米考星具有同泰乐菌素相似的广谱抗菌活性 ,对革兰氏阳性菌和某…     

磷酸替米考星体外抑菌活性检测

采用微量稀释法来测定磷酸替米考星等药物对9种微生物的最小抑菌浓度(MIC),评价其抗菌活性。结果:磷酸替米考星对猪胸膜肺炎放线杆菌、猪链球菌、副猪嗜血杆菌等临床常见畜禽致病菌均有良好的抗菌活性,MIC均在0.004 9~2.5μg/m L;对猪肺炎支原体与鸡毒支原体的MIC分别为0.004 9 ccu/m L和0.312 5 ccu/m L,表现出显著的抑菌活性。磷酸替米考星与其他抗生素相比,抑菌活性好或相当,与其主要对照药物替米考星相比,具有更好的水溶性。结果显示磷酸替米考星可用于治疗由这些敏感菌所致的疾病。     

复方板黄口服液对畜禽常见病原菌的体外抑菌作用研究

为了研究板黄口服液对畜禽常见病原菌的体外抑菌作用,研究通过体外试验观察药物对禽巴氏杆菌、鸡葡萄球菌、鸡白痢沙门杆菌、肺炎克雷伯菌、牛巴氏杆菌、牛大肠杆菌的抑菌效果。结果表明:板黄口服液对鸡葡萄球菌的最小抑菌浓度(MIC)为125 mg/m L,对牛巴氏杆菌、禽巴氏杆菌、鸡白痢沙门杆菌、肺炎克雷伯菌、牛大肠杆菌的MIC均为250 mg/m L。说明板黄口服液对禽巴氏杆菌、鸡葡萄球菌、鸡白痢沙门杆菌、肺炎克雷伯菌、牛巴氏杆菌、牛大肠杆菌有很好的抑制作用。     

新兽药"菌灭"抑菌试验初报

为了解抗菌新兽药“菌灭”的抑菌活性,采用试管2倍稀释法对“菌灭”与头孢唑林钠、环丙沙星以畜禽常见的19种病原菌进行了体外抑菌活性比较试验。结果表明,“菌灭”对畜禽常见的十几种病原菌抑菌效果均优于头孢唑林钠,总体上与环丙沙星相当。     

Bacterial flora of liver abscesses in feedlot cattle fed tylosin or no tylosin.

Bacterial flora of liver abscesses from cattle fed tylosin or no tylosin and susceptibilities of the predominant bacterial isolates to tylosin and other antimicrobial compounds were determined. Abscessed livers were collected at slaughter from cattle originating from feedlots that had fed tylosin (n = 36) or no tylosin (n = 41) for at least 2 yr, and segments of livers with one or two intact abscesses were transported to the laboratory. Abscesses were cultured for anaerobic and facultative bacteria. Fusobacterium necrophorum, either as single culture or mixed with other bacteria, was isolated from all abscesses. The incidence of subsp. necrophorum, as part of the mixed infection, was lower (P < .05) in the tylosin group than in the no-tylosin group (33 vs 61%). However, the incidence of Actinomyces pyogenes was higher (P < .01) in the tylosin group than in the no-tylosin group (53 vs 10%). Totals of 119 F. necrophorum and 21 A. pyogenes isolates were used for determinations of susceptibilities to bacitracin, oxytetracycline, chlortetracycline, lasalocid, monensin, tylosin, tilmicosin, and virginiamycin. The minimum inhibitory concentrations (MIC) of antibiotics were determined with a broth microdilution method. The mean MIC of tylosin for F. necrophorum and A. pyogenes were not different between isolates from tylosin and no-tylosin groups. We concluded that continuous feeding of tylosin did not induce resistance in F. necrophorum or A. pyogenes. Also, the higher incidence of mixed infection of F. necrophorum and A. pyogenes in liver abscesses of tylosin-fed cattle suggests a potential synergistic interaction between the two organisms in causing liver abscesses.     

Antibacterial activity of chaff vinegar and its practical application

Since enterohemorrhagic Escherichia coli O157, Salmonella, etc., sometimes contaminate animal feces and may cause infectious diseases to humans, it is important to remove pathogenic bacteria from domestic animal waste. For the purpose, we examined the antibacterial activity of chaff vinegar. We found that the chaff vinegar inhibited the growth of pathogenic bacteria immediately in vitro but not efficiently spores and lactic acid bacteria. Further, it removes bacteria, especially Enterobacteriaceae, from animal feces and the surface of the concrete-floor in the cattle barn. Chaff vinegar is advertised as a natural chemical substance for a soil conditioner, to promote the composting and to deodorize their smell. Chaff vinegar may be useful for organic agriculture without enteric pathogenic bacteria.     

一例鸡大肠杆菌病的病原分离鉴定

为确诊某养鸡场发病的原因,采集临床病死鸡的肝脏、脾脏进行细菌分离培养,并通过细菌形态学观察、生化试验、分子生物学鉴定和药物敏感性试验.结果:分离细菌为革兰氏阴性杆菌,菌落形态和生化鉴定特征与大肠杆菌相符;16S rDNA PCR扩增及基因同源性分析确定为大肠杆菌;菌株对安普霉素、泰妙菌素、多西环素、硫酸粘菌素较敏感,对替米考星、泰万菌素、磺胺间甲氧嘧啶、泰乐菌素、阿莫西林存在耐药性.     

Effect of parenteral administration of erythromycin, tilmicosin, and tylosin on abomasal emptying rate in suckling calves

OBJECTIVE: To determine the effect of parenteral administration of erythromycin, tilmicosin, and tylosin on abomasal emptying rate in suckling calves. ANIMALS: 8 male Holstein-Friesian calves < 35 days old. PROCEDURES: Calves received each of 4 treatments in random order (2 mL of saline [0.9% NaCl] solution, IM [control treatment]; erythromycin, 8.8 mg/kg, IM; tilmicosin, 10 mg/kg, SC; and tylosin, 17.6 mg/kg, IM). Calves were fed 2 L of milk replacer containing acetaminophen (50 mg/kg) 30 minutes later. Jugular venous blood samples and transabdominal ultrasonographic abomasal dimensions were obtained periodically after suckling. Abomasal emptying rate was assessed on the basis of the time to maximal plasma acetaminophen concentration and ultrasonographic determination of the halftime of abomasal emptying. One-tailed Dunnett post tests were conducted whenever the F value for group was significant. RESULTS: Emptying rate was faster for erythromycin, tilimicosin, and tylosin than for the control treatment, as determined on the basis of time to maximal plasma acetaminophen concentration. Ultrasonography indicated that the half-time of abomasal emptying was significantly shorter for erythromycin than for the control treatment. Tylosin and tilmicosin accelerated the abomasal emptying rate, but not significantly, relative to the emptying rate for the control treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Administration of erythromycin, tilmicosin, and tylosin at the label dosage increased abomasal emptying rate in calves. The clinical importance of an increase in abomasal emptying rate in cattle remains to be determined.     

替米考星对雏鸡增重及预防人工感染禽巴氏杆菌的效果观察

将替米考星以 3个剂量 (10 0mg/L、 2 0 0mg/L、 30 0mg/L)和泰乐菌素以 50 0mg/L给雏鸡饮水给药 5d,结果 2种药物对雏鸡均有明显的增重效果 ,且替米考星给药量与增重效果呈正相关。人工感染试验结果显示 ,替米考星 3个剂量预防组及泰乐菌素预防组对抗御人工感染禽巴氏杆菌均有明显的效果 ,但替米考星 3个剂量预防组的抗感染效果均极显著高于泰乐菌素预防组 (P <0 0 1)。试验结果表明 ,替米考星饮水给药对雏鸡除具有增重作用外 ,还具有抗感染 ,降低发病率 ,减少病理损害 ,提高成活率的作用 ;预防呼吸道疾病的效果明显优于泰乐菌素     

替米考星(Tilmicosin)对鸡败血霉形体感染的药效学

以试管二倍稀释法测定替米考星 (Tilmicosin)及对照药物强力霉素、红霉素、泰乐菌素对鸡败血霉形体的最小抑菌浓度分别为 0 .0 0 6 2 5、0 .0 2 5、0 .0 2 5、0 .1m g/ L ,进行了替米考星对鸡败血霉形体的体内药效学研究。结果 ,替米考星以 5 0、75、10 0 mg/ L 饮水给药 5 d,对实验性感染鸡败血霉形体有显著疗效 ,用药组增重均显著高于对照组 (P<0 .0 5或 P<0 .0 1) ,并能明显减少抗体阳性反应率 ,极显著地减少气囊损伤记分 (P<0 .0 1)     

Characterization of in vivo-acquired resistance to macrolides of Mycoplasma gallisepticum strains isolated from poultry

ABSTRACT: The macrolide class of antibiotics, including tylosin and tilmicosin, is widely used in the veterinary field for prophylaxis and treatment of mycoplasmosis. In vitro susceptibility testing of 50 strains of M. gallisepticum isolated in Israel during the period 1997-2010 revealed that acquired resistance to tylosin as well as to tilmicosin was present in 50% of them. Moreover, 72% (13/18) of the strains isolated from clinical samples since 2006 showed acquired resistance to enrofloxacin, tylosin and tilmicosin. Molecular typing of the field isolates, performed by gene-target sequencing (GTS), detected 13 molecular types (I-XIII). Type II was the predominant type prior to 2006 whereas type X, first detected in 2008, is currently prevalent. All ten type X strains were resistant to both fluoroquinolones and macrolides, suggesting selective pressure leading to clonal dissemination of resistance. However, this was not a unique event since resistant strains with other GTS molecular types were also found. Concurrently, the molecular basis for macrolide resistance in M. gallisepticum was identified. Our results revealed a clear-cut correlation between single point mutations A2058G or A2059G in domain V of the gene encoding 23S rRNA (rrnA, MGA_01) and acquired macrolide resistance in M. gallisepticum. Indeed, all isolates with MIC ≥ 0.63 μg/mL to tylosin and with MIC ≥ 1.25 μg/mL to tilmicosin possess one of these mutations, suggesting an essential role in decreased susceptibility of M. gallisepticum to 16-membered macrolides.     

HPLC法在监控替米考星合成中的应用

采用高效液相色谱法对替米考星合成生产过程进行监控,对泰乐菌素原料A、B两种组分在合成替米考星反应过程中的变化进行了探讨,该项研究成功解决了替米考星合成过程中收率降低的问题。