阿莫西林对副猪嗜血杆菌和猪胸膜肺炎放线杆菌的药敏试验

以大肠杆菌ATCC25922为质控菌株,采用阿莫西林对5株猪胸膜肺炎放线杆菌和6株副猪嗜血杆菌进行药敏试验,测定其最小抑菌浓度(MIC)。结果表明,胸膜肺炎放线杆菌和副猪嗜血杆菌对阿莫西林敏感。     

盐酸多西环素与土霉素对胸膜肺炎放线杆菌的体外抑菌效果研究

为研究盐酸多西环素、土霉素对胸膜肺炎放线杆菌的抗菌活性,本试验采用微量肉汤稀释法,对胸膜肺炎放线杆菌进行了体外药敏试验。结果显示,盐酸多西环素对胸膜肺炎放线杆菌的MIC范围为0.125~1.0μg/mL,土霉素对胸膜肺炎放线杆菌的MIC范围为0.125~1.0μg/mL,两种药物对胸膜肺炎放线杆菌的体外抗菌活性相当。结果表明,盐酸多西环素和土霉素对胸膜肺炎放线杆菌具有良好体外抑菌作用。     

中草药提取物对多重耐药猪胸膜肺炎放线杆菌体外抑菌试验及抑菌效果研究

为筛选对猪接触传染性胸膜肺炎放线杆菌多重耐药菌株有较好抑菌作用的中草药。挑选了穿心莲、黄芩、苦参、白头翁、芒果叶和百里香6种中草药,采用水提取和65%乙醇提取相结合的方法制备单剂中草药的提取液,然后浓缩至含原生药物1g/mL。采用二倍稀释法分别测定这6种中草药对传染性胸膜肺炎放线杆菌多重耐药菌株的最小抑菌浓度(minimal inhibition concentration, MIC)和最小杀菌浓度(minimal bacteriocidal concentration, MBC)。以筛选出体外抑菌效果较好的中草药。结果表明,胸膜肺炎放线杆菌多重耐药菌株抑菌圈最大的是百里香和芒果叶,其抑菌圈直径分别为40 mm和35 mm.,其次为白头翁、黄芩、穿心莲和苦参,其抑菌圈直径在8~16 mm。百里香、芒果叶、白头翁、黄芩、穿心莲和苦参的最小抑菌浓度分别为0.198 mg/mL、0.198 mg/mL、0.396 mg/mL、0.396 mg/mL、25 mg/mL和25 mg/mL。百里香、芒果叶、白头翁、黄芩、穿心莲和苦参的最小杀菌浓度分别为0.396 mg/mL、0.396 mg/mL、0.792 mg/mL、0.792 mg/mL、50 mg/mL和50 mg/mL。说明除穿心莲和苦参外,其余4种中草药对胸膜肺炎放线杆菌多重耐药菌株有很多好的抑菌和杀菌效果,其中百里香和芒果叶效果最佳。本结果为由传染性胸膜肺炎放线杆菌多重耐药菌引起的猪接触传染性胸膜肺炎的防控和治疗奠定了基础,为开发中草药相关无抗产品以及防治由多重耐药菌引起的猪接触传染性胸膜肺炎提供了参考。     

大青叶抗胸膜肺炎放线杆菌活性部位的初步分离

提取分离大青叶并测定各级提取物对猪胸膜肺炎放线杆菌的抑菌活性。采用二倍稀释法测定最小抑菌浓度(Minimal inhibitoryconcentration,MIC)和最小杀菌浓度(Minimal bactericidal concentration,MBC)以追踪大青叶的活性部位及其活性成分。采用80%的乙醇提取并通过硅胶柱色谱法对其进一步分离,测定抑菌活性,追踪其活性段。同时以石油醚、氯仿、乙酸乙酯、丙酮、甲醇、水依次提取,测定抑菌活性,并对提取物的化学成分进行初步分析。硅胶柱色谱各分离组分对试验菌均有不同程度的抑制作用,抑菌效果最好的为组分3,其MIC为3.91 mg/mL。各级提取物中抑菌活性较好的为乙酸乙酯提取物,其MIC为3.91 mg/mL。其抑制胸膜肺炎放线杆菌生长的主要成分可能为生物碱、有机酸和黄酮类物质。     

蒲公英提取物对猪致病菌的体外抑菌作用

试验应用药敏纸片法和液体试管试验法研究蒲公英提取物对猪链球菌、猪胸膜肺炎放线杆菌、多杀性巴氏杆菌的体外抗菌作用,结果显示:蒲公英提取物对猪链球菌、猪胸膜肺炎放线杆菌、多杀性巴氏杆菌均有较好的抑制作用,其抑菌效果有浓度依赖性,最小抑菌浓度分别为9.3 g/L、14.6 g/L、11.7 g/L。     

猪胸膜肺炎放线杆菌自动转运黏附素基因的克隆与表达

为了研究猪胸膜肺炎放线杆菌保护性免疫机制,试验筛选猪胸膜肺炎放线杆菌3~8 kb随机基因组文库,获得1株阳性克隆,测序拯救质粒得到序列,通过Blast分析确定此片段为猪胸膜肺炎放线杆菌自动转运黏附素(AT-Adhensin)基因,根据序列设计特异性引物PCR扩增该基因,分子克隆表达该黏附素蛋白。结果表明,该蛋白与猪传染性胸膜肺炎康复期血清发生反应。     

复方氟苯尼考注射液体外抑菌试验及对人工感染巴氏杆菌仔猪的保护效果

为了研究复方氟苯尼考注射液的体外抗菌活性及对人工感染巴氏杆菌仔猪的保护效果。本研究采用体外抑菌试验采用试管二倍稀释法,测定复方氟苯尼考注射液和单方氟苯尼考注射液对多杀性巴氏杆菌、副猪嗜血杆菌、猪传染性胸膜肺炎放线杆菌及链球菌的最小抑菌浓度(MIC)。体内治疗试验是将复方氟苯尼考注射液分为20、40、60mg/kg 3个剂量组与氟苯尼考对照组(40mg/kg)以及氟尼辛葡甲胺对照组(3.65mg/kg)以颈部肌肉注射治疗人工感染多杀性巴氏杆菌的仔猪。体外抑菌试验结果显示,复方氟苯尼考注射液对多杀性巴氏杆菌、副猪嗜血杆菌、猪传染性胸膜肺炎放线杆菌及链球菌的MIC分别为0.59、1.09、0.59、2.12mg/L;氟苯尼考注射液对多杀性巴氏杆菌、副猪嗜血杆菌、猪传染性胸膜肺炎放线杆菌及链球菌的MIC分别为1.12、6.13、17.86、17.86mg/L。保护性试验结果显示,复方氟苯尼考注射液低、中、高剂量组增重率分别为(10.19±4.84)、(14.33±4.07)、(15.53±5.38)kg,死亡率分别为10%、10%、0,好转率分别为60%、90%、100%,治愈率分别为20%、90%、100%;氟苯尼考组的增重率为(9.90±4.25)kg;氟尼辛葡甲胺组的增重率为(8.02±3.83)kg。结果表明,复方氟苯尼考注射液对多杀性巴氏杆菌、副猪嗜血杆菌、猪传染性胸膜肺炎放线杆菌及链球菌的抑菌效果强于单方氟苯尼考注射液;复方氟苯尼考注射液对人工感染多杀性巴氏杆菌仔猪的保护作用也优于氟苯尼考注射液。建议本品的治疗剂量为颈部肌肉注射40mg/kg,每7d给药1次,连用2次,如症状严重可2d给药1次,连用2次。     

猪胸膜肺炎放线杆菌的分离与鉴定

吉林省某规模化养猪场送检疑似猪传染性胸膜肺炎的死猪病料,采用不同培养基进行病原菌分离,结果分离出3株疑似胸膜肺炎放线杆菌。通过对分离菌进行镜检、培养特性试验、生化特性试验、PCR鉴定,确定为3株均为胸膜肺炎放线杆菌,致病性试验结果表明,分离的胸膜肺炎放线杆菌具有强致病性。     

应用PCR技术快速检测猪胸膜肺炎放线杆菌

为了研究猪传染性胸膜肺炎放线杆菌的快速检测技术,试验采用GenBank中猪传染性胸膜肺炎放线杆菌APXⅣA基因的序列设计了1对引物,建立了检测猪胸膜肺炎放线杆菌的PCR方法。结果表明:猪胸膜肺炎放线杆菌血清1～10型均能扩增出预期片段,而金黄色葡萄球菌、链球菌、多杀性巴氏杆菌、支气管败血波氏杆菌、副猪嗜血杆菌、大肠杆菌的扩增结果均为阴性;用该方法检测自猪鼻腔采集的87份鼻拭子,有15份为阳性,72份为阴性。说明建立的猪胸膜肺炎放线杆菌PCR方法可用于猪胸膜肺炎的快速诊断。     

氟苯尼考单用及联用对副猪嗜血杆菌和胸膜肺炎放线杆菌的体外抑菌效果

为研究氟苯尼考和多西环素、甲氧苄啶、黏杆菌素的临床配伍对副猪嗜血杆菌及胸膜肺炎放线杆菌感染的治疗效果,采用棋盘法测定氟苯尼考与其他三种抗生素联合使用对上述两种细菌的体外抑菌效果、结果表明:氟苯尼考与多西环素联合使用对副猪嗜血杆菌和胸膜肺炎放线杆菌的抑菌具有协同作用(FIC=0.75);与甲氧苄啶联合使用均表现为无关作用(FIC=1.5);与黏杆菌素联合使用对副猪嗜血杆菌呈现无关作用(FIC=2),而对胸膜肺炎放线杆菌呈现协同作用(FIC=0.75)。     

Effect of danofloxacin (Advocin A180) on goats affected with contagious caprine pleuropneumonia

The efficacy of danofloxacin (Advocin A180) was evaluated for the treatment of contagious caprine pleuropneumonia (CCPP) caused by Mycoplasma capricolum subsp. capripneumoniae. Ten healthy Angora goats, confirmed free of CCPP, were exposed to clinically affected animals from a natural outbreak in Thrace, Turkey. After 14 days exposure, 8 goats showed pyrexia ( > or = 41 degrees C). Shortly after, the Angora goats were divided randomly into two groups. Five of these were injected with danofloxacin (6 mg/kg subcutaneously), which was repeated after 48 h; the five remaining animals received saline. Goats were monitored clinically and blood samples were collected for serology. Animals with severe disease were withdrawn from the trial. Goats completing the study were euthanized at day 42. Lung tissue and bronchial fluid were collected for mycoplasma isolation. All danofloxacin-treated goats showed resolution of clinical disease by the end of the trial. Two saline-treated goats failed to complete the study owing to CCPP. Danofloxacin-treated goats showed fewer lung lesions and had significantly lower combined clinical scores than saline controls (p < 0.001). Danofloxacin was found to be highly effective in the treatment of CCPP in goats.     

Comparison of in vitro activity of danofloxacin, florfenicol, oxytetracycline, spectinomycin and tilmicosin against Mycoplasma mycoides subspecies mycoides small colony type

Minimum inhibitory concentrations (MIC) and minimum mycoplasmacidal concentrations (MMC) of the antimicrobials danofloxacin, florfenicol, oxytetracycline, spectinomycin and tilmicosin were determined in vitro for 20 isolates of Mycoplasma mycoides subspecies mycoides small colony type (MmmSC), the causative agent of contagious bovine pleuropneumonia (CBPP). The majority of strains were most susceptible to tilmicosin, followed by danofloxacin, oxytetracycline, florfenicol and spectinomycin with MIC50 values of 0.015, 0.25, 0.5, 1 and 8 microg/ml, and MMC50 values of 0.06, 0.5, 8, 8 and 16 microg/ml, respectively. However, tilmicosin had poor mycoplasmacidal activity against two recent strains from Portugal. There was no evidence of resistance to danofloxacin in any of the strains.     

Danofloxacin (Advocin) reduces the spread of contagious bovine pleuropneumonia to healthy in-contact cattle

Contagious bovine pleuropneumonia (CBPP), caused by Mycoplasma mycoides subsp. mycoides SC (MmmSC), is one of the most important diseases of cattle in Sub-Saharan Africa. The live T1/44 vaccine is normally used for its control but produces only transient protection and gives rise to adverse reactions. The present study evaluated the efficacy of danofloxacin (2.5% Advocintrade mark, Pfizer Ltd.) for the treatment of naturally infected cattle and in the prevention of CBPP transmission to in-contact cattle. Adult cattle, taken from a natural outbreak, were placed into two groups of 10 animals and kept on a research farm in paddocks 50m apart. One group was treated with 2.5mg/kg danofloxacin on days 0, 1 and 2; the other group were saline treated. On day 2, 10 CBPP-free, seronegative cattle were placed in contact with each of the two groups. All cattle were monitored for 3.5 months. No differences were seen in clinical improvement of the CBPP-affected cattle treated with danofloxacin compared with the untreated CBPP-affected cattle with approximately half of each group being withdrawn because of CBPP or showing CBPP lesions at post mortem examination. Clinical scores of the two groups were also similar. However cattle kept in contact with the danofloxacin-treated CBPP-affected animals showed significantly fewer lesions, less mortality and fewer animals were seropositive (P<0.02) and had reduced clinical scores (P<0.001) compared to cattle kept in contact with untreated CBPP-affected cattle. MmmSC was also isolated from fewer contact controls kept with the treated group. These findings could have important implications for the control of CBPP in Africa.     

The efficacy of danofloxacin in the therapy of pneumonia associated with Pasteurella species in housed calves

The efficacy of danofloxacin, a novel third generation fluoroquinolone, was assessed in the treatment of pneumonia in housed calves on three farms in the FDR and Italy. Seventy three calves with clinical signs of acute pneumonia and rectal temperatures greater than 40 degrees C were treated with danofloxacin at a dose rate of 1.25 mg/kg for three or five days depending on response to treatment. The response in these calves was compared to that obtained in 77 calves treated with trimethoprim/sulpha. The clinical response achieved with danofloxacin was superior to that achieved with trimethoprim/sulpha and significantly fewer calves which received danofloxacin required five days treatment. Pasteurella haemolytica and, or P. multocida were isolated from the majority of calves prior to treatment. All isolates were sensitive to danofloxacin and over 90 percent were sensitive to trimethoprim/sulpha.     

Efficacy of danofloxacin in the treatment of respiratory disease in European cattle

The efficacy of an injectable formulation of danofloxacin (180 mg/ml) in the treatment of naturally occurring bovine respiratory disease was evaluated in field studies on farms in France, Ireland and the United Kingdom. Cattle aged one week to 15 months with clinical respiratory disease were randomly allocated to treatment with 6 mg/kg danofloxacin or 10 mg/kg tilmicosin, administered by a single subcutaneous injection on day 0. A second injection of danofloxacin was administered on day 2, only if predefined clinical criteria were met. Mannheimia haemolytica, Pasteurella multocida and Haemophilus somnus were isolated from pretreatment nasopharyngeal swabs taken on all the farms. After the treatment, there was a more rapid improvement in the clinical response of the 178 animals treated with danofloxacin by day 2 (P < 0.01) than in the 90 treated with tilmicosin. For both treatments, there were similar significant (P < 0.001) reductions in the mean rectal temperature and severity of clinical signs of abnormal respiration and depression, on days 4 and 10 compared with day 0; 78.1 per cent of the animals treated with danofloxacin and 78.5 per cent of those treated with tilmicosin completed the studies. Danofloxacin 18 per cent was clinically safe and as effective as tilmicosin in the treatment of bovine respiratory disease.     

Antimicrobial susceptibility of Actinobacillus pleuropneumoniae isolated from pigs in Korea using new standardized procedures

The in vitro susceptibilities of 76 isolates of Actinobacillus pleuropneumoniae collected from pigs with pleuropneumonia were tested with 12 commonly used antimicrobial drugs by an agar dilution minimal inhibitory concentration procedure according to National Committee for Clinical Laboratory Standards (NCCLS) guidelines. Field isolates had low MICs for ceftiofur, danofloxacin and penicillin. No correlation of antimicrobial resistance was related to serotype.     

Evaluation of a single dose versus a divided dose regimen of danofloxacin in treatment of Actinobacillus pleuropneumoniae infection in pigs

A single versus a divided dose regimen of danofloxacin was evaluated in treatment of porcine Actinobacillus pleuropneumoniae infection using clinical observations combined with biochemical infection markers: C-reactive protein, zinc and ascorbic acid. Twenty hours after experimental infection, the 18 pigs received danofloxacin intravenously as a single dose of 2.5mg/kg or four doses of 0.6 mg/kg administered at 24h intervals. These dosage regimens resulted in similar AUCs of the plasma danofloxacin vs time curve. The maximum concentration was 3.5-fold higher using the single dose regimen, while the time with concentrations above the MIC was 2.5-fold longer using the fractionated regimen. Using the single dose regimen, temperature was normalised 32 h post-infection. In contrast, normalisation was delayed until 44 h post-infection using four low doses and a relapse with elevated temperatures at 52 and 68 h was observed. No other significant differences between the treatments were found, neither regarding clinical, haematological nor biochemical observations. The use of the more convenient single dose regimen was appropriate, as it was at least equivalent to the fractionated regimen.     

Comparison of pharmacokinetics of danofloxacin and enrofloxacin in calves challenged with Mannheimia haemolytica

OBJECTIVE: To compare concentrations of danofloxacin, enrofloxacin, and ciprofloxacin in plasma and respiratory tissues of calves treated after challenge with Mannheimia haemolytica. ANIMALS: 75 calves. PROCEDURE: 24 hours after challenge with M. haemolytica, 72 calves with clinical signs of respiratory tract disease were randomly assigned to 1 of 12 equal treatment groups.Three nonchallenged, nontreated calves formed a control group. Challenged calves were treated with danofloxacin (6 and 8 mg/kg, SC) and enrofloxacin (8 mg/kg, SC) once. At 1, 2, 6, and 12 hours after treatment, 6 calves from each treatment group were euthanatized. Antimicrobial drug concentrations were assayed in various specimens. Peak plasma concentration (Cmax)-to-minimum inhibitory concentration (MIC; Cmax-to-MIC) ratios and the area under the concentration versus time curve over a 12-hour period-to-MIC ratios (AUC(12h)-to-MIC) were calculat-ed. RESULTS: Danofloxacin and enrofloxacin had MICs of 0.03 microg/mL for the M. haemolytica challenge isolate. Danofloxacin administered at doses of 6 and 8 mg/kg resulted in numerically higher geometric mean concentrations of danofloxacin in plasma and all respiratory tissues than geometric mean concentrations of enrofloxacin after treatment with enrofloxacin. Geometric mean concentrations of enrofloxacin were numerically higher than geometric mean concentrations of ciprofloxacin metabolite in plasma and almost all respiratory tissues. Danofloxacin and enrofloxacin achieved Cmax-to-MIC ratios >10 and AUC(12h)-to-MIC ratios >125 hours. CONCLUSIONS AND CLINICAL RELEVANCE: When used to treat pneumonic pasteurellosis in calves, danofloxacin and enrofloxacin can be expected to deliver concentration-dependent bactericidal activity against M. haemolytica, the bacteria most commonly associated with bovine respiratory tract disease.     

In vitro antibacterial susceptibility of Arcobacter butzleri isolated from different sources

The objective of this study was to determine the antibiotic susceptibility of Arcobacter spp. isolated from various sources. Seventy Arcobacter spp. isolates were tested for their susceptibility to 13 antimicrobial agents. Antimicrobial susceptibility testing was performed by using the agar disc diffusion method on Mueller-Hinton agar supplemented with 5% defibrinated sheep blood. The antibiotics tested included enrofloxacin, erythromycin, streptomycin, gentamycin, rifampin, tetracycline, ampicillin, trimethoprim/sulfamethoxazole, nalidixic acid, danofloxacin, amoxycillin-clavulonic acid, cefuroxime-sodium, neomycine. Although all the arcobacters tested were susceptible to gentamycin, resistance to three or more antibacterial agents (especially, trimethoprim/sulfamethoxazole, cefuroxime-sodium and rifampin) was observed. A. butzleri isolates were found to be resistant to amoxycillin+clavulonic acid, nalidixic acid and ampicillin, at the rate of 20%, 44.28% and 78.57% respectively. In conclusion, gentamycin, streptomycin and tetracycline may be suitable antibiotics for the treatment or control of disease caused by Arcobacter spp. in veterinary and human medicine.     

Comparative study of the plasma pharmacokinetics and tissue concentrations of danofloxacin and enrofloxacin in broiler chickens

The plasma pharmacokinetics of danofloxacin and enrofloxacin in broiler chickens was investigated following single intravenous (i.v.) or oral administration (p.o.) and the steady-state plasma and tissue concentrations of both drugs were investigated after continuous administration via the drinking water. The following dosages approved for the treatment of chickens were used: danofloxacin 5 mg/kg and enrofloxacin 10 mg/kg of body weight. Concentrations of danofloxacin and enrofloxacin including its metabolite ciprofloxacin were determined in plasma and eight tissues by specific and sensitive high performance liquid chromatography methods. Pharmacokinetic parameter values for both application routes calculated by noncompartmental methods were similar for danofloxacin compared to enrofloxacin with respect to elimination half-life (t1/2: approximately 6-7 h), mean residence time (MRT; 6-9 h) and mean absorption time (MAT; 1.44 vs. 1.20 h). However, values were twofold higher for body clearance (ClB; 24 vs. 10 mL/min. kg) and volume of distribution at steady state (VdSS; 10 vs. 4 L/kg). Maximum plasma concentration (Cmax) after oral administration was 0.5 and 1.9 micrograms/mL for danofloxacin and enrofloxacin, respectively, occurring at 1.5 h for both drugs. Bioavailability (F) was high: 99% for danofloxacin and 89% for enrofloxacin. Steady-state plasma concentrations (mean +/- SD) following administration via the drinking water were fourfold higher for enrofloxacin (0.52 +/- 0.16 microgram/mL) compared to danofloxacin (0.12 +/- 0.01 microgram/mL). The steady-state AUC0-24 h values of 12.48 and 2.88 micrograms.h/mL, respectively, derived from these plasma concentrations are comparable with corresponding area under the plasma concentration-time curve (AUC) values after single oral administration. For both drugs, tissue concentrations markedly exceeded plasma concentrations, e.g. in the target lung, tissue concentrations of 0.31 +/- 0.07 microgram/g for danofloxacin and 0.88 +/- 0.24 microgram/g for enrofloxacin were detected. Taking into account the similar in vitro activity of danofloxacin and enrofloxacin against important pathogens in chickens, a higher therapeutic efficacy of water medication for enrofloxacin compared to danofloxacin can be expected when given at the approved dosages.