洛美沙星对实验性鸡葡萄球菌病的药效研究

为了给兽医临床推广应用国内新近研制的氟喹诺酮类长半减期药物洛美沙星（Ｌｏｍｅｆｌｏｘａｃｉｎ），特别是用洛美沙星防治鸡葡萄球菌病提供依据，首先以试管２倍稀释法测定了洛美沙星及对照药对金黄色葡萄球菌的最小抑菌浓度，然后观察了洛美沙星、环丙沙星、恩诺沙星饮水给药５ｄ对实验性鸡葡萄球菌病的疗效。结果，洛美沙星、环丙沙星、恩诺沙星、诺氟沙星、红霉素对鸡金黄色葡萄球菌Ｃ５６０１１株的最小抑菌浓度分别为１．０、０．１２５、０．２５、１．０、３２ｍｇ／Ｌ。２５、５０、１００ｍｇ／Ｌ洛美沙星饮水给药对鸡葡萄球菌病的治愈率分别为６６．７％、８０．０％、７６．７％，有效率分别为９０．０％、９６．７％、９６．７％。５０ｍｇ／Ｌ环丙沙星、５０ｍｇ／Ｌ恩诺沙星的治愈率则分别为７６．７％、８０．０％，有效率分别为９３．３％、９６．７％。５０、１００ｍｇ／Ｌ洛美沙星及５０ｍｇ／Ｌ恩诺沙星３个饮水给药组的增重显著高于感染对照组。结果表明，洛美沙星饮水给药治疗鸡葡萄球菌病以５０ｍｇ／Ｌ的剂量为宜。     

氧氟沙星对实验性鸡大肠杆菌病的药效研究

以试管肉汤两倍稀释法测得氧氟沙星及氯霉素对鸡大肠杆菌的最小抑菌浓度分别为０．１及１．６ｍｇ／Ｌ，按５，１０和２０ｍｇ／ｋｇ的氧氟沙星及４０ｍｇ／ｋｇ的氯霉素分别给实验性鸡大肠杆菌病患鸡内服，每１２ｈ服药１次，共３ｄ。这些药物对鸡大肠杆菌病的治愈率分别为９０．０％，９３．３％，９６．７％及８３．３％，而感染对照鸡的死亡率为６３．３％。氧氟沙星和氯霉素的增重效果极显著高于感染对照鸡（Ｐ＜０．０１）。     

洛美沙星对实验性鸡葡萄球菌病的药效研究

为了探讨国内新近研制的氟喹诺酮类长半减期药物洛美沙星（Ｌｏｍｅｆｌｏｘａｃｉｎ）对鸡葡萄球菌病的疗效进行了本研究。以试管２倍稀释法测定洛美沙星及对照药对金黄色葡萄球菌的最小抑菌浓度，然后用洛美沙星、环丙沙星、恩诺沙星进行饮水给药５ｄ的疗效试验。结果表明，洛美沙星、环丙沙星、恩诺沙星、诺氟沙星、红霉素对鸡金黄色葡萄球菌Ｃ５６０１１株的最小抑菌浓度分别为１．０、０．１２５、０．２５、１．０、３２ｍｇ／Ｌ。２５、５０、１００ｍｇ／Ｌ洛美沙星饮水给药对鸡葡萄球菌病的治愈率分别为６６．７％、８０％、７６．７％，有效率分别为９０％、９６．７％、９６．７％。５０ｍｇ／Ｌ环丙沙星、恩诺沙星的治愈率则分别为７６．７％、８０％，有效率分别为９３．３％、９６．７％。５０、１００ｍｇ／Ｌ洛美沙星及５０ｍｇ／Ｌ恩诺沙星３个饮水给药组鸡的增重显著高于感染对照组。     

三种恩诺沙星盐对人工诱发鸡巴氏杆菌病的疗效比较

采用试管肉汤两倍稀释法,测得乳酸恩诺沙星、盐酸恩诺沙星及恩诺沙星钾对鸡多杀性巴氏杆菌的最小抑菌浓度均为０．０５ｍｇ／Ｌ。按５ｍｇ／ｋｇ恩诺沙星的剂量,分别给人工诱发巴氏杆菌病鸡内服乳酸恩诺沙星、盐酸恩诺沙星及肌注乳酸恩诺沙星、恩诺沙星钾,每１２ｈ给药１次,连续３ｄ。这些药物对鸡巴氏杆菌病的治愈率分别为１００％、９６．７％、１００％,而感染对照鸡的死亡率为１００％。结果表明,上述三种恩诺沙星盐对鸡巴     

国产泰乐菌素治疗猪肺炎支原体病（猪喘气病）实验报告

用国产泰乐菌素治疗猪肺炎支原体（ＭＰＳ）病，按２６ｍｇ（高）、１３ｍｇ（中）、５ｍｇ（低）／ｋｇ体重肌肉注射，每天２次，连续７天为一个疗程。第一个疗程治愈率分别为５４．５％、５４．５％、６３．６％；未愈猪做第二个疗程，治愈率分别为３３．３％、５５．５％、４４．４％。中剂量组与进口泰乐菌素同等剂量组治愈率相同。用国产泰乐菌素预防ＭＰＳ病，按１３ｍｇ／ｋｇ体重肌肉注射，每天２次，连续７天，结果保护８／１０，阳性对照猪１０／１０发病。     

氟罗沙星对禽败血霉形体（Mycoplasma gallisepticum）病的药效研究

体外抑菌试验测得氟罗沙星（Ｆｌｅｒｏｘａｃｉｎ）对禽败血霉形体（Ｍｙｃｏｐｌａｓｍａｇａｌｉｓｅｐｔｉｃｕｍ）的最小抑菌浓度（ＭＩＣ）为０．０１５ｍｇ／Ｌ。体内药效试验表明,氟罗沙星以２５、５０、１００ｍｇ／Ｌ饮水给药和以５、１０、１５ｍｇ／ｋｇ肌注给药（１次／ｄ）,连续用药５ｄ,对人工气囊接种禽败血霉形体培养液（０．２ｍＬ,约含１０８ｃｆｕ）的雏鸡,保护率均为１００％（３０／３０）,而感染不给药组雏鸡存活率为９３．３％（２８／３０）;相对增重率分别为９０．８％、９１．５％、９２．３％和９１．５％、９１．８％、９２．９％,显著高于感染不给药组（７３．２％）;气囊损伤分分别为２．９３、２．６２、０．９３和１．８、１．１、１．０,而感染不给药组为６．５７,差异显著（Ｐ＜０．０５）;血清玻板凝集试验阳性率分别为２０％（２／１０）、１０％（１／１０）、０（０／１０）和３０％（３／１０）、１０％（１／１０）、１０％（１／１０）,均极显著低于感染不给药组１００％（１０／１０）（Ｐ＜０．０１）。氟罗沙星不同给药途径及不同剂量间药效差异不显著。     

乙基环丙沙星对实验性感染猪链球菌病及水肿病的药效学研究

本文报道以国内新近研制的畜禽专用氟喹诺酮类抗菌药──乙基环丙沙星（Ｅｎｒｏｆ－ｌｏｘａｃｉｎ），进行对实验性感染猪链球菌病及水肿病的药效学研究（２３０头猪）。试管两倍稀释法测得乙基环丙沙星对兰氏Ｃ群类马链球菌（Ｃ＿（５５１２０））和猪大肠杆菌（Ｏ＿（５４））的最小抑菌浓度（ＭＩＣ）分别是０．８及０．０５μｇ／ｍｌ。肌注给药对猪链球菌病和水肿病的实验性治疗结果表明，乙基环丙沙星低、中、高剂量组（分别为１．２５、２．５、１０ｍｇ／ｋｇ）用药６０（每天２次）对猪链球病的治愈率分别是５０％、９５％及９５％，而链球菌感染对照组的死亡率为７０％；乙基环丙沙星低、中、高剂量组（分别为１．２５、２．５、１０ｍｇ／ｋｇ）用药３ｄ（每隔１２ｈ给药一次）对猪水肿病的治愈率分别是８５％、９０％及９０％；而大肠杆菌感染对照组的死亡率为９０％。     

氧氟沙星对霉形体与大肠杆菌合并感染鸡的药效学研究

以试管两倍稀释法测得氧氟沙星及其对照药物恩诺沙星、洛美沙星和强力霉素对鸡败血霉形体的最小抑菌浓度分别为０．００６２５、０．０２５、０．４和０．４ｍｇ／Ｌ。５０、１００、２００ｍｇ／Ｌ氧氟沙星、５０ｍｇ／Ｌ恩诺沙星、５０ｍｇ／Ｌ洛美沙星和１００ｍｇ／Ｌ强力霉素连续５ｄ饮水给药,对人工合并感染败血霉形体和大肠杆菌病鸡的治愈率分别是９３．３％、９６．７％、９６．７％、１００％、９６．７％和８３．３％,感     

脱氧土霉素对人工诱发鸡大肠杆菌病的疗效观察

以试管两部稀释法测定脱氧土霉素对鸡大肠杆菌的最小抑菌浓度，然后对人工诱发雏鸡大肠杆菌进行混饮或混料给药５天的治疗试验，结果表明：脱氧土霉素对鸡大肠杆菌的最小抑菌浓度为２．０ｍｇ／Ｌ，脱氧土霉素１００ｐｐｍ，混饮和２００ｐｐｍ混饲对大肠杆菌病的治愈率分别为９０．０％及９３．３％，而感染对照组的死亡率为６０．０％，用药组的增重效果显著高于感染对照组（Ｐ〈０．０５）。     

金霉素,泰妙菌素联合应用对鸡败血霉形体病的药效研究

观察了金霉素、泰妙菌素联合用药的体外抗鸡败血霉形体的作用与体内治疗鸡败血霉形体病的疗效。体外抑菌试验中，金霉素、泰妙菌素、金霉素与泰妙菌素（３∶１）合用，对鸡败血霉形体ＢＧ４４Ｔ株的最小抑菌浓度分别为２．０、０．０１６、０．０１６ｍｇ／Ｌ；棋盘法试验进一步证明，金霉素、泰妙菌素合用对鸡败血霉形体ＢＧ４４Ｔ株的ＦＩＣ指数为０．５～０．７５，两药表现有协同作用。饮水给药对实验性鸡败血霉形体病的治疗试验表明，金霉素、泰妙菌素按３∶１合用，以２００、１００ｍｇ／Ｌ剂量给药５ｄ，在死亡率、治愈率、有效率等几个指标方面优于泰妙菌素、金霉素单独给药（２００ｍｇ／Ｌ）。     

沙拉沙星对实验性感染猪链球菌病及大肠杆菌病的药效学

为兽医临床合理应用沙拉星（Ｓarafloxacin）提供理论依据,就其对实验性感染猪链球菌 病及大肠杆菌病的药效学进行了研究。以试管２倍稀释法测得沙拉沙星对兰氏Ｃ群类马链球菌（Ｃ５５１２０）和猪大肠杆菌（Ｏ５５）的最小抑菌浓度（ＭＩＣ）分别是０．８mg/Ｌ及０．０５mg/Ｌ。肌注给药对猪链球菌病和大肠杆菌病的试验性治疗结果不明,低、中 高剂量沙拉沙星组２．５、５、１０mg/kg）及环丙沙星组（５mg/kg）用药５d（每隔１２     

二氟沙星对实验性感染猪链球菌病及支原体性肺炎的药效学研究

本文报道国内新近研制的畜禽专用氟喹诺酮类抗菌药物－二氟沙星对实验性感染猪链球菌病及支原体性肺炎的药效学研究。以试管两倍稀释法测得二氟沙星对兰氏C群类马链球菌（C55120）和猪肺炎支原体（F16株）的最小抑菌浓度（MIC）分别是1．6级及0．16mg/L。肌注给药对猪链球菌病和支原体性肺炎的实验性治疗结果表明，低、中、高剂量二氟沙星组（2．5、5、10mg/kg)及恩诺沙星组（2．5mg/kg)用药5d（每隔12h给药1次）对猪链球菌病的治愈分别是40％、70％、80％及70％，而链球菌感染对照组的死亡率为70％；低、中、高剂量二氟沙星组及恩诺沙星组（2．5mg/kg)用药5d（每隔12h给药1次）对猪支原体性肺炎的治愈率分别是80％、90％、90％及80％；而支原体感染对照组的自愈率为10％。     

二氟沙星对实验性感染猪支原体性肺炎及链球菌病的药效学研究

以试管两倍稀释法测得二氟沙星对猪肺炎支原体（ Ｆ１６ 株）和兰氏 Ｃ 群类马链球菌（ Ｃ５５ １ ２０ ）的最小抑菌浓度分别是０１６ｍ ｇ／ Ｌ及 １６ｍ ｇ／ Ｌ。肌注给药对猪支原体性肺炎及链球菌病的实验性治疗结果表明,低、中、高剂量二氟沙星组（２５、５、１０ｍ ｇ／ｋｇ）及蒽诺沙星组（２５ｍ ｇ／ｋｇ）用药 ５ 天（每隔 １２ 小时给药一次）对猪支原体性肺炎的治愈率分别是 ８０％ 、９０％ 、１００％ 及９０％ ;而支原体感染对照组的自愈率为１０％ 。低、中、高剂量二氟沙星组及蒽诺沙星组（２５ｍ ｇ／ｋｇ）用药 ４ 天（每隔 １２ 小时给药一次）对猪链球菌病的治愈率分别是 ５０％ 、８０％ 、８０％ 及 ８０％ ,而链球菌感染对照组的死亡率为 ５０％ 。     

碱偏离型恩诺沙星注射液的临床应用研究

为了研究碱偏离型恩诺沙星注射液对人工感染大肠杆菌O78雏鸡的治疗作用,本试验以8日龄的雏鸡为试验动物,腹腔注射一定剂量的O78菌悬液,建立雏鸡大肠杆菌人工感染模型,然后给予不同剂量碱偏离型恩诺沙星注射液对其进行治疗试验。结果显示,给予1.75mg/kg碱偏离型恩诺沙星注射液进行预防给药,其增重率显著升高,增重率和有效率分别为102.45%和100%;给予1.75mg/kg碱偏离型恩诺沙星注射液进行治疗给药,雏鸡增重率、治愈率和有效率分别为93.34%、70%和83%,试验证明,碱偏离型恩诺沙星注射液能有效防治人工感染雏鸡大肠杆菌病,为兽医临床应用碱偏离型恩诺沙星注射液治疗雏鸡大肠杆菌病提供了理论依据。     

头孢噻呋钠对1日龄雏鸡实验性感染鸡大肠杆菌病的药效试验

通过预先颈部皮下注射头孢噻呋钠,评价其对1日龄雏鸡试验性诱导大肠杆菌病的预防效果。以微量法测得头孢噻呋钠和恩诺沙星对鸡大肠杆菌的MIC分别为0.1mg/L和1.6mg/L。试验结果表明,0.2、0.1、0.05mg/只的头孢噻呋钠各用药组对人工诱导鸡大肠杆菌病的保护率分别为100%、90%和80%,与0.125mg/只的恩诺沙星对照组(63.33%)及感染对照组(46.67%)相比,头孢噻呋钠各剂量组均能显著降低1日龄雏鸡人工诱发大肠杆菌病的死亡率(P<0.01),具有很好的预防效果;试验结束后细菌学检测结果表明,头孢噻呋钠各剂量组和药物对照组鸡的大肠杆菌检出率分别为13.33%、23.33%、30.0%、46.67%,与感染对照组(90%)相比均显著减少(P<0.01)。     

氟甲砜霉素对鸭大肠杆菌病的药效研究

为了探讨氟甲砜霉素对鸭大肠杆菌病的疗效进行了本研究。用试管2倍稀释法测定氟甲砜霉素及对照药氯霉素对大肠杆菌的最小抑菌浓度，然后用氟甲砜霉素，氯霉素进行混饲给药5d的疗效试验，试验结果表明，氟甲砜霉素，氯霉素对大肠杆菌O78株的最小抑菌浓度分别为6mg/L,8mg/L,100,200,400mg/kg氟甲砜霉素混饲给药对鸭大肠杆菌病的有效率分别为30．3％，93．9％，100％,400mg/kg氯霉素的有效率为93．9％，试验各组之间鸭的增重差异不显著。     

单诺沙星对人工诱发鸡大肠肝菌病的药效试验

根据试管 2倍稀释法测定的单诺沙星及氯霉素对鸡大肠杆菌的最小抑菌浓度 ,对实验性大肠杆菌病鸡进行内服给药 (每隔 12h给药 1次 ,连续 3d)治疗试验。结果表明 ,单诺沙星及氯霉素对鸡大肠杆菌的最小抑菌浓度分别是 0 0 5及 1 6mg/L。单诺沙星以 5mg/kg、氯霉素以40mg/kg的剂量给鸡内服后 ,对大肠杆菌病的治愈率分别为 87 5%及 55 0 %。     

Tissue distribution and disposition kinetics of enrofloxacin in healthy and E. coli infected broilers

Concentrations of enrofloxacin equivalent activity were determined by microbiological assay in the plasma of healthy and E. coli-infected broilers following single intravenous and oral administrations at 10 mg/kg. Tissue distribution and residue-depletion following multiple oral doses (10 mg/kg for 3 successive days) were investigated. Pharmacokinetic variables were determined using compartmental and non-compartmental analytical methods. Plasma enrofloxacin concentrations after intravenous dosing to healthy and infected birds were best described by a two-compartments model. Enrofloxacin concentrations in plasma of infected birds were lower than those of healthy ones. The disposition kinetics of intravenously administered drug in healthy and infected birds were somewhat different. The elimination half-life (t1/2 beta) was 4.75 vs. 3.63 h; mean residence time (MRT) was 6.72 vs 4.90 h; apparent volume of the central compartment (Vc) was 1.11 vs 1.57 l/kg; rate constant for transfer from peripheral to central compartment (k21) was 1.15 vs 1.41 h-1 and total body clearance (ClB) was 0.35 vs 0.53 l/h/kg in healthy and infected birds, respectively. After oral administration, the absorption half-life (t1/2abs) in the infected birds was significantly longer than in healthy birds, while elimination half-life (t1/2el) and MRT were significantly shorter. Bioavailability was higher in infected birds (72.50%) as compared to healthy ones (69.78%). Enrofloxacin was detected in the tissues of healthy and infected birds after daily oral dosing of 10 mg/kg for 3 days. It was more concentrated in liver, kidney, and breast muscle. The minimal inhibitory concentration (MIC) of enrofloxacin against E. coli was 0.064 microgram/ml. On the basis of maintaining enrofloxacin plasma concentrations over the MIC, a dose of 10 mg/kg given intravenously every 20.14 hrs or orally every 20.86 hrs should provide tissue concentrations effective against E. coli infection in chickens.     

Susceptibility of canine and feline Escherichia coli and canine Staphylococcus intermedius isolates to fluoroquinolones

OBJECTIVES AND DESIGN: 1) A prospective study to determine in vitro concentrations for a range of fluoroquinolones, gentamicin and amoxycillin-clavulanate required to inhibit growth of recently collected, feline and canine Escherichia coli and canine Staphylococcus intermedius isolates. 2) A comparative retrospective study to compare the minimum inhibitory concentrations (MICs) of ciprofloxacin, enrofloxacin and amoxycillin-clavulanate for archived canine E coli and S intermedius isolates collected ten to twenty years earlier, with those for recently collected isolates. PROCEDURE: Susceptibility was assessed using disk diffusion, agar dilution susceptibility testing and Epsilometer tests (E-tests) for both recently collected and archived isolates. RESULTS: All feline E coli isolates and recently collected canine S intermedius isolates were susceptible to all fluoroquinolones. There was a statistically significant increase in the MIC range of ciprofloxacin and enrofloxacin for recently collected E coli, and in the MIC range of amoxycillin-clavulanate for recently collected S intermedius isolates compared to archived isolates. Twelve of 59 recently collected canine E coli isolates were resistant to both ciprofloxacin and enrofloxacin. Resistant canine E coli isolates were associated with complicating host or infection site factors. CONCLUSION: This is the first report comparing the MICs for all veterinary fluoroquinolones currently available in Australia for a representative sample of canine and feline E coli and canine S intermedius isolates. Importantly, this study identified 12 of 59 canine E coli isolates resistant to fluoroquinolones and identified the development of low level resistance in canine E coli to ciprofloxacin and enrofloxacin and canine S intermedius to amoxycillin-clavulanate.