首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 187 毫秒
1.
从2008年送检的病猪病料中分离到1株致细胞病变代次、时间以及细胞病变形态与典型高致病性猪繁殖与呼吸综合征病毒(HP-PRRSV)培养特性不同的PRRSV(LD812株)。对LD812株的Nsp2和ORF5基因进行测序发现,该株病毒与标准HP-PRRSVJXA1株(与VR2332相比,JXA1Nsp2基因的第478、538～566位氨基酸缺失,缺失形式为1+29个氨基酸)的Nsp2基因同源性为98.3%,LD812分离株Nsp2基因上第475～520和538～566位氨基酸缺失,缺失形式为46+29个氨基酸,比JXA1株在1号缺失位多缺失45个氨基酸;LD812株ORF5基因序列与JXA1株相比仅有8个核苷酸的点突变。结合该毒株的临床特征、细胞培养及分子特性,推测LD812为一弱毒株。  相似文献   

2.
为了分析内化素InlK对单增李斯特菌(Listeria monocytogenes,LM)生物学特性及致病性的影响,利用自杀性质粒进行同源重组构建LM标准菌株10403s的inlK基因缺失株,然后比较分析野生株、inlK基因缺失株的生长特性、生物被膜形成能力、细胞侵袭能力、动物致病力等差异。结果显示,inlK基因缺失不影响LM的生长速度,但可导致LM的生物被膜形成能力下降。细胞感染试验表明基因缺失株ΔinlK对RAW264.7细胞的侵袭及胞内存活能力分别下降了18%和31%。动物感染试验显示野生株和基因缺失株ΔinlK对小鼠的致死率分别为80%(4/5)和40%(2/5),且基因缺失株ΔinlK的体内定殖能力显著低于野生株。本研究表明内化素InlK在LM感染过程中发挥着重要作用,为了解LM的致病作用提供参考。  相似文献   

3.
采用丹麦ROSCO药敏纸片扩散法,检测12株家兔须癣毛癣菌对伊曲康唑、酮康唑、氟康唑、特比萘酚、克霉唑、氟胞嘧啶、沃尔康唑和制霉菌素等8种抗真菌药物的敏感性。结果:特比萘酚对须癣毛癣菌的抑菌圈直径最大(平均73 mm),而且12株菌100%对其敏感,抗菌效果最好;其后依次是沃尔康唑、克霉唑和伊曲康唑,按ROSCO严格判读标准12株菌对其敏感率分别为83.3%、83.3%和8.3%;抑菌效果最差的是氟胞嘧啶和氟康唑,按ROSCO基本判读标准其耐药(不敏感)率分别为100%和83.3%。  相似文献   

4.
为获得毒力较弱并能区分自然感染和疫苗免疫的布鲁氏菌候选疫苗株,本研究用PCR方法扩增WboA基因的上下游同源臂序列,构建重组质粒pGEM-7zf-△WboA-Sac,电转化布鲁氏菌M5-90感受态细胞,筛选布鲁氏菌疫苗株M5-90的WboA基因缺失株,并对获得的M5-90△WboA遗传稳定性、毒力、免疫保护性、抗体水平等指标进行检测.实验结果表明M5-90△WboA株的毒力比M5-90株明显减弱,差异极显著(p＜0.01),体液免疫和细胞免疫结果表明M5-90△WboA株与亲本M5-90株相比差异不显著(p＜0.05),M5-90△WboA株和亲本株的保护率分别为10％和20％,表明M5-90△WboA株与M5-90株具有相似的保护性.凝集试验和western blot试验显示M5-90△WboA株免疫小鼠的血清反应结果为阴性.本研究构建的布鲁氏菌基因缺失株M5-90△WboA具有较好的遗传稳定性,毒力比亲本株更弱,免疫保护性与亲本株相当,并能以血清学检测方法区分野毒株感染和缺失疫苗株免疫的动物.  相似文献   

5.
为了探究细胞溶素HlyE突变体(HlyE-V)对禽致病性大肠杆菌(APEC)致病力的影响，采用Red同源重组法构建了APEC菌株CBE59的HlyE-V基因缺失株CBE59ΔHlyE-V和回补株CBE59CΔHlyE-V,测定缺失株生长曲线、溶血活性、胞内存活曲线，并用细胞毒性试验和动物试验来评估HlyE-V对APEC致病力的影响。结果表明∶缺失HlyE-V基因对APEC的生长速率影响较小，野生株、缺失株和回补株均无溶血活性，证明HlyE-V不是孔道形成毒素，不能溶解哺乳动物的红细胞；HlyE-V缺失株致细胞毒性和对雏鸡的致病力显著降低，缺失株的半数致死量(LD50)值为4.9×106CFU/只，而野生株和回补株的LD50分别为8.2×105CFU/只、4.2×105CFU/只；在HD11巨噬细胞内的存活能力显著下降，在野生株CBE59感染的HD11中有一半的细胞中含有6～8个细菌，且有56.7%的细胞中观察到超过6个细菌；而在观察缺失株CBE59ΔHlyE-V时，菌量超过6个...  相似文献   

6.
试验旨在构建布鲁氏菌Ⅳ型分泌系统vceA基因缺失株,分析其生长特征及其在人胚胎滋养层细胞(HPT-8)中的存活能力。以布鲁氏菌S2308为模板,PCR扩增vceA基因上、下游同源臂,以pUC19K质粒为模板扩增kan基因,然后利用融合PCR技术将3段基因进行融合,再将此片段与pMD19-T载体连接,电转至大肠杆菌DH5α感受态细胞中,构建ΔvceA基因缺失株(S2308ΔvceA),通过卡那抗性对缺失株进行连续筛选,并检测其遗传稳定性。在相同培养条件下,观察亲本株S2308和S2308ΔvceA的生长变化趋势,以侵染复数(MOI)100∶1侵染HPT-8细胞,通过CFU计数检测亲本株S2308和缺失株S2308ΔvceA在细胞内的生存能力。结果显示,试验成功获得片段大小为372、510、1 093 bp的vceA基因上、下游同源臂和kan基因;且成功构建pMD19-T-vceA-kan自杀载体,将其电转入大肠杆菌DH5α感受态细胞,构建基因缺失株,连续传代10次未发现基因回复突变;在体外相同培养条件下,缺失株S2308ΔvceA与亲本株S2308生长趋势相似,均在12 h达到对数生长期,30 h进入平台期;侵染HPT-8细胞12 h时,缺失株S2308ΔvceA在细胞中的数量显著低于亲本株S2308(P<0.05)。综上所述,本试验成功构建并获得了具有良好遗传稳定性的布鲁氏菌vceA基因缺失株,该缺失株在体外培养条件下与亲本株生长趋势相似;但该缺失株在HPT-8细胞内的存活能力显著变弱。  相似文献   

7.
为研究猪繁殖与呼吸综合征病毒(PRRSV)遗传变异特点,本研究在PRRSV流行病学调查中分离到一株PRRSV,该分离株在高致病性PRRSV(HP-PRRSV)NSP2区1 aa+29 aa缺失的基础上,突变为49 aa+29 aa的缺失株,将其命名为Henan-A14(NCBI序列号:KJ819936)。此外,该分离株在MARC-145细胞中的复制能力减弱,即其细胞嗜性有所改变。血清中和试验结果显示5份HP-PRRSV疫苗抗血清均不能中和该分离株,推测其抗原发生了较大变异。为鉴定该缺失是否影响病毒的复制,本研究以HP-PRRSV p Hu N4-F112株的感染性克隆为骨架,拯救出一株在NSP2区相应位置连续缺失48 aa的重组病毒,而该重组病毒在MARC-145细胞中的复制及血清中和试验结果表明,NSP2基因区48 aa缺失既不影响PRRSV的复制效率,也不影响病毒对HP-PRRSV制备的阳性血清中和效率。本研究的结果证明Henan-A14分离株在MARC-145细胞中复制能力的降低,以及病毒抗原中和表位与NSP2中相关的氨基酸缺失无直接关系。该分离株的鉴定为进一步研究HP-PRRSV的变异具有重要的参考价值。  相似文献   

8.
试验旨在构建布鲁氏菌Ⅳ型分泌系统vceA基因缺失株,分析其生长特征及其在人胚胎滋养层细胞(HPT-8)中的存活能力。以布鲁氏菌S2308为模板,PCR扩增vceA基因上、下游同源臂,以pUC19K质粒为模板扩增kan基因,然后利用融合PCR技术将3段基因进行融合,再将此片段与pMD19-T载体连接,电转至大肠杆菌DH5α感受态细胞中,构建ΔvceA基因缺失株(S2308ΔvceA),通过卡那抗性对缺失株进行连续筛选,并检测其遗传稳定性。在相同培养条件下,观察亲本株S2308和S2308ΔvceA的生长变化趋势,以侵染复数(MOI)100∶1侵染HPT-8细胞,通过CFU计数检测亲本株S2308和缺失株S2308ΔvceA在细胞内的生存能力。结果显示,试验成功获得片段大小为372、510、1 093 bp的vceA基因上、下游同源臂和kan基因;且成功构建pMD19-T-vceA-kan自杀载体,将其电转入大肠杆菌DH5α感受态细胞,构建基因缺失株,连续传代10次未发现基因回复突变;在体外相同培养条件下,缺失株S2308ΔvceA与亲本株S2308生长趋势相似,均在12 h达到对数生长期,30 h进入平台期;侵染HPT-8细胞12 h时,缺失株S2308ΔvceA在细胞中的数量显著低于亲本株S2308(P0.05)。综上所述,本试验成功构建并获得了具有良好遗传稳定性的布鲁氏菌vceA基因缺失株,该缺失株在体外培养条件下与亲本株生长趋势相似;但该缺失株在HPT-8细胞内的存活能力显著变弱。  相似文献   

9.
广东省某猪场暴发以高热、高发病率和高死亡率为特征的传染病.采集该猪场濒死猪的肺脏,接种Marc-145细胞,产生典型的细胞病变,收集病毒液并命名该病毒为PRRSV YA株.实时荧光RT-PCR试验显示YA株是基因缺失型变异株.扩增YA株的Nsp2基因的部分序列并进行核苷酸克隆、测序,结果显示Nsp2基因缺失第481位和第532～560位氨基酸.扩增Gp5基因序列并测序,绘制遗传进化树,结果显示YA株属于美洲型毒株,与其他7株已发表的高致病性PRRSV同源性达98.8%以上.用YA株病毒接种4头仔猪,其发病率和死亡率分别为100%(4/4)和75%(3/4).  相似文献   

10.
拟研究LuxS/AI-2群体感应系统对肠炎沙门菌(Salmonella enterica Serovar Enteritidis,SE)生物学特性的影响。利用Red同源重组系统构建LuxS/AI-2系统关键基因luxS缺失株,通过比较亲本株和luxS缺失株体外生长速率、药物敏感性、细胞黏附侵袭能力及生物被膜形成能力等生物学特性,初步分析AI-2/LuxS系统对SE生物学特性的影响。结果显示,luxS缺失株能够稳定遗传缺失的△luxS基因;体外生长速率略快;生物被膜形成能力明显增强;对DF-1细胞和Caco-2细胞黏附侵袭能力均显著增加;对氟喹诺酮类药物敏感性提高128~256倍,对氨苄西林、四环素、多西环素、氯霉素和氟苯尼考类等的药物敏感性提高了8倍。以上结果表明,LuxS系统影响肠炎沙门菌的生物学特性(如生物被膜形成、对细胞的黏附侵袭能力),并且该系统也通过某种耐药机制影响肠炎沙门菌的药物敏感性。  相似文献   

11.
This study determined the residual concentration of terbinafine in cat hair after 14 days of oral treatment. Ten clinically normal cats were administered terbinafine orally at a daily dose of 34-45.7 mg kg(-1) for a total of 14 days. Areas of 15 cm(2) were shaved on the lateral thorax at day 0 and weekly for 8 weeks after the last dose of terbinafine. The hair samples were analysed by high-pressure liquid chromatography to determine the persistence of terbinafine over time. The mean terbinafine concentration in hair was 2.30 ng mg(-1) after 14 days of therapy. The half life was 1.84 weeks after the last dose of terbinafine. With a 99% confidence interval, the concentration of terbinafine remained in the cat hair at or above 0.03 ng mg(-1) (minimal inhibitory concentration (MIC)(90) = 0.03 microg mL(-1)) for 5.3 weeks. Slight deviations in the complete blood cell count and serum chemistry values were not attributed to terbinafine. Four cats experienced vomiting during the terbinafine treatment; two of these cats also experienced intense facial pruritus followed by a macular to papular skin reaction 7-14 days after the discontinuation of terbinafine. In summary, terbinafine persists in hair at concentrations above the MIC for several weeks after stopping medication, even after short-term therapy (14 days). These results suggest that pulse therapy of terbinafine should be further researched and potentially considered as a treatment modality for feline dermatophytosis, an approach that would decrease treatment duration while maintaining effectiveness.  相似文献   

12.
以家蚕真菌病病原为受试菌,对抗真菌药物氟康唑(FCZ)和盐酸特比萘芬(TBF·HCl)进行了体外筛选,研究了盐酸特比萘芬对家蚕真菌病的防治效果及其稳定性。试验结果表明,盐酸特比萘芬的体外抑菌、杀菌效果优于氟康唑,盐酸特比萘芬对家蚕病原真菌的最小抑菌浓度范围为0.0625～0.2726μg/mL,最小杀菌浓度范围为0.125～4μg/mL。生物试验表明,盐酸特比萘芬对家蚕真菌病防治效果良好,200μg/mL时防治效果达100%,且对家蚕生长发育、茧质无不良影响。稳定性试验表明盐酸特比萘芬长期稳定性良好。  相似文献   

13.
Pharmacokinetics of oral terbinafine in horses and Greyhound dogs   总被引：1，自引：0，他引：1  
The objective of the study was to assess the pharmacokinetics of terbinafine administered orally to horses and Greyhound dogs. A secondary objective was to assess terbinafine metabolites. Six healthy horses and six healthy Greyhound dogs were included in the pharmacokinetic data. The targeted dose of terbinafine was 20 and 30 mg/kg for horses and dogs, respectively. Blood was collected at predetermined intervals for the quantification of terbinafine concentrations with liquid chromatography and mass spectrometry. The half-life (geometric mean) was 8.1 and 8.6 h for horses and Greyhounds, respectively. The mean maximum plasma concentration was 0.31 and 4.01 μg/mL for horses and Greyhounds, respectively. The area under the curve (to infinity) was 1.793 h·μg/mL for horses and 17.253 h·μg/mL for Greyhounds. Adverse effects observed in one study horse included pawing at the ground, curling lips, head shaking, anxiety and circling, but these resolved spontaneously within 30 min of onset. No adverse effects were noted in the dogs. Ions consistent with carboxyterbinafine, n-desmethylterbinafine, hydroxyterbinafine and desmethylhydroxyterbinafine were identified in horse and Greyhound plasma after terbinafine administration. Further studies are needed assessing the safety and efficacy of terbinafine in horses and dogs.  相似文献   

14.
The pharmacokinetics of terbinafine was studied in six healthy fasted cats following a single intravenous and oral administration at a dose of 10 mg/kg and 30 mg/kg, respectively, according to a two-period crossover design. Plasma terbinafine concentrations were determined using a reverse phase liquid chromatographic method. The pharmacokinetic parameters were calculated by non-compartmental analysis with WinNonlin 5.2.1 software. After intravenous administration, the terminal half-life and area under the curve from time 0 to infinity were 10.40 ± 4.56 h, 15.20 ± 3.61 h·μg/ml, respectively. After oral dosing, the mean maximum concentration was 3.22 ± 0.60 μg/ml, reached at 1.33 ± 0.41 h. The terminal half-life, area under the curve from time 0 to infinity and apparent volume of distribution were 8.01 ± 3.46 h, 13.77 ± 4.99 h·μg/ml, 25.63 ± 6.29 l/kg, respectively. The absolute bioavailability of terbinafine hydrochloride tablets after oral administration was 31.00 ± 10.85%. Although bioavailability was low, excellent penetration at the site of infection and low minimum inhibitory concentrations values provided terbinafine with good efficacy against dermatophyte infections.  相似文献   

15.
The present study investigated the in vitro inhibitory activity of terbinafine, itraconazole, caspofungin, fluvastatin and ibuprofen against 15 isolates of Pythium insidiosum in double and triple combinations and determined in vivo correlations using rabbits with experimental pythiosis. The minimal inhibitory concentration (MIC) was determined in accordance with the Clinical and Laboratory Standards Institute M 38-A2 protocol (2008), and the in vitro interactions were evaluated using a checkerboard microdilution method. For the in vivo study, 20 rabbits inoculated with P. insidiosum zoospores were divided into four groups: group 1 was treated with terbinafine and itraconazole; group 2 was treated with terbinafine, itraconazole and fluvastatin; group 3 was treated with terbinafine and caspofungin; and group 4 was the control group. Combinations of terbinafine with caspofungin or ibuprofen were synergistic for 47% of the isolates, and antagonism was not observed in any of the double combinations. The triple combinations were mostly indifferent, but synergism and antagonism were also observed. In the in vivo study, the histological aspect of the lesions was similar among the groups, but group 2 showed the lowest amount of hyphae and differed significantly from the other groups.  相似文献   

16.
Chytridiomycosis, a skin disease caused by Batrachochytrium dendrobatidis, has caused amphibian declines worldwide. Amphibians can be treated by percutaneous application of antimicrobials, but knowledge of in vitro susceptibility is lacking. Using a modified broth microdilution method, we describe the in vitro sensitivity of two Australian isolates of B. dendrobatidis to six antimicrobial agents. Growth inhibition was observed, by measurement of optical density, with all agents. Minimum inhibitory concentrations (µg/ml; isolate 1/2) were – voriconazole 0.016/0.008; itraconazole 0.032/0.016; terbinafine 0.063/0.063; fluconazole 0.31/0.31; chloramphenicol 12.5/12.5; amphotericin B 12.5/6.25. Killing effects on zoospores were assessed by observing motility. Amphotericin B and terbinafine killed zoospores within 5 and 30 min depending on concentration, but other antimicrobials were not effective at the highest concentrations tested (100 µg/ml). This knowledge will help in drug selection and treatment optimization. As terbinafine was potent and has rapid effects, study of its pharmacokinetics, safety and efficacy is recommended.  相似文献   

17.
Ophidiomyces ophiodiicola, the causative agent of snake fungal disease, is proposed as a serious threat to the conservation of several snake populations. The objective of this study was to determine the pharmacokinetic parameters of terbinafine administered through nebulization and a sustained subcutaneous implant as potential treatments of Ophidiomyces in reptiles. Seven adult cottonmouths (Agkistrodon piscivorus) were used in single‐dose trials. Each snake was nebulized with terbinafine (2 mg/ml) for 30 min and had blood collected before nebulization and up to 12 hr after nebulization. Following a 5‐month washout, the same snakes were administered a subcutaneous implant containing 24.5 mg terbinafine; blood was collected at baseline, 1 day postimplant placement, and then once weekly for 9 weeks. Plasma for both studies was analyzed by high‐performance liquid chromatography. The mean plasma concentrations of nebulized terbinafine peaked between 0.5 and 4 hr. The subcutaneously implanted terbinafine reached therapeutic concentrations on day 1 and maintained therapeutic for over 6 weeks. These methods and doses are recommended as potential treatment options for snake fungal disease in reptiles.  相似文献   

18.
The purpose of this randomized, single blinded clinical trial was to evaluate cytologically and clinically the efficacy of oral cephalexin alone and its combination with terbinafine or ketoconazole for the treatment of Malassezia dermatitis in dogs. Twenty-two client-owned dogs with Malassezia dermatitis completed the 3-week study. All received cephalexin (generic, 250 mg or 500 mg) at 22-30 mg kg(-1) twice daily. Eight dogs received terbinafine at 30 mg kg(-1) once daily and seven dogs received ketoconazole (generic, 200 mg) at 5-10 mg kg(-1) twice daily. The remaining seven dogs received cephalexin alone. At week 0 (visit 1) and week 3 (visit 2), mean yeast counts were determined from three affected areas using tape-strip cytology, a clinical index score (CIS) was assigned to the affected areas, and owners evaluated pruritus using a visual analogue scale. All groups showed reduction in mean yeast counts, CIS and pruritus. There was an 86.8%, 80.2% and 28.8% reduction in mean yeast counts from visit 1 to visit 2 for the terbinafine, ketoconazole and cephalexin-only groups, respectively. However, within treatment group comparisons a significant reduction in mean yeast count was only evident for the terbinafine (P < 0.002) and ketoconazole (P < 0.01) groups. Pruritus reduction was only significant for the terbinafine group. These preliminary results suggest that terbinafine should be further assessed for the treatment of canine Malassezia dermatitis.  相似文献   

19.
Terbinafine is an allylamine antifungal prescribed for the treatment of mycoses in humans. It is increasingly being used in veterinary patients. The purpose of this study was to evaluate the pharmacokinetic properties of terbinafine in dogs after a single oral dose. Ten healthy adult dogs were included in the study. A single dose of terbinafine (30–35 mg/kg) was administered orally, and blood samples were periodically collected over a 24 h period during which dogs were monitored for adverse effects. Two of 10 dogs developed transient ocular changes. A high‐performance liquid chromatography assay was developed and used to determine plasma terbinafine concentrations. Pharmacokinetic analysis was performed using PK Solutions® computer software. Area under the curve (AUC) from time 0 to 24 h was 15.4 μg·h/mL (range 5–27), maximal plasma concentration (Cmax) was 3.5 μg/mL (range 3–4.9 μg/mL) and time to Cmax (Tmax) was 3.6 h (range 2–6 h). The time above minimal inhibitory concentration (T > MIC) as well as AUC/MIC was calculated for important invasive fungal pathogens and dermatophytes. The T > MIC was 17–18 h for Blastomyces dermatitidis, Histoplasma capsulatum and dermatophytes (Microsporum spp. and Trichophyton mentagrophytes), while the MIC for Sporothrix schenckii and Coccidioides immitis was exceeded for 9.5–11 h. The AUC/MIC values ranged from 9 to 13 μg h/mL for these fungi. Our results provide evidence supporting the use of terbinafine as an oral therapeutic agent for treating systemic and subcutaneous mycoses in dogs.  相似文献   

20.
A 19-yr-old intact male Coquerel's sifaka (Propithecus coquereli) was evaluated for a crusting facial dermatopathy. Fungal culture and histopathology of skin biopsies were consistent with dermatophytosis caused by Trichophyton mentagrophytes, and treatment with the antifungal medication terbinafine was initiated. After 1 mo of treatment, all clinical signs had resolved and a fungal culture of the skin was negative. The sifaka was treated with terbinafine for a total of 81 days. Two additional fungal cultures were taken and found to be negative for the presence of dermatophytes, the last culture being taken 1 mo after discontinuation of terbinafine. To the authors' knowledge, this is the first reported case of dermatophytosis in a prosimian species and the first reported treatment of a prosimian with the antifungal drug terbinafine.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号