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1.
Antibiogram and heavy metal resistance patterns of pathogenic bacteria isolated from moribund cage cultured silver catfish (Pangasius sutchi) and red hybrid tilapia (Tilapia sp.) from Sungai Manir, Terengganu, Malaysia were studied and characterized. Sungai Manir is one of the famous rivers in Terengganu for its wide variety of cage cultured freshwater fish. However, to date, the baseline information of antibiogram and heavy metal resistance patterns of the pathogenic bacteria attacking the freshwater fish cultured in Sungai Manir is still lacking. Therefore, this study was carried out, which may be useful for fish farmers as a guideline for fish prophylactic and treatment purposes. Furthermore, present studies also provide information on the safety level of consuming freshwater fish produced from Sungai Manir. In the present study, bacteria were isolated from 100 fish of each moribund silver catfish and red hybrid tilapia using seven media including tryptic soy agar (TSA), Mac Conkey, thiosulphate citrate bile salt (TCBS), eosin methylene blue (EMB), glutamate starch pseudomonas (GSP), xylose lysine deoxycholate (XLD) and Baird Parker media. Identification of bacteria was carried out using conventional biochemical tests and confirmed by commercial bacterial identification kit. Antibiogram of the bacterial isolates against 18 antibiotics; oxolinic acid (2 μg), ampicillin (10 μg), erythromycin (15 μg), furazolidone (15 μg), lincomycin (15 μg), oleandomycin (15 μg), amoxicillin (25 μg), colistin sulphate (25 μg), sulphamethoxazole (25 μg), chloramphenicol (30 μg), doxycycline (30 μg), florfenicol (30 μg), flumequine (30 μg), kanamycin (30 μg), nalidixic acid (30 μg), tetracycline (30 μg), nitrofurantoin (50 μg) and spiramycin (100 μg) was carried out using disk diffusion method, whereas heavy metal resistance patterns (Hg2+, Cd2+, Cr6 + and Cu2+) of the bacterial isolates was determined through twofold agar dilution method. The results showed that the percentage of sensitivity case of the 120 bacterial isolates to the tested antibiotics was 62.7%. This was followed by resistance (26.9%) and intermediary sensitive (10.4%) cases. In terms of the heavy metal resistance patterns, all bacterial isolates were resistant to Hg2+ and Cr6 +. However, only 27.8% and 16.7% of the bacterial isolates were sensitive to Cu2+ and Cd2+, respectively. The multiple antibiotic resistance (MAR) indices indicated that the cage cultured silver catfish and red hybrid tilapia were under high exposure to the tested antibiotic. Overall, the results of the present studies showed that Sungai Manir may be polluted with heavy metal and antibiotic residues.  相似文献   

2.
SW  Lee  M  Najiah  W  Wendy  A  Zahrol  M  Nadirah 《中国农业科学(英文版)》2009,8(6):740-745
In this article, antibiogram and heavy metal resistance profile of bacteria isolated from giant freshwater prawn （Macrobrachium rosenbergii） hatchery in Malaysia are described. Although giant freshwater prawn was introduced into Malaysia since the 1980s, there was no database information on antibiogram and heavy metal resistance profile of bacteria from giant freshwater prawn （34. rosenbergii） hatchery in Malaysia. Therefore, this study was carried out to determine the effectiveness of antibiotic and heavy metal resistance profile to control bacterial diseases in M. rosenbergii hatchery. The results can provide valuable information for local M. rosenbergii post-larval producer. Antibiotic sensitivity test was carried out by disk-diffusion method against 15 types of antibiotics as follows： oxolinic acid （2 μg）, ampicillin （10μg）, erythromycin （15μg）, furazolidone （15 μg）, lincomycin （15μg）, amoxicillin （25 μg）, colistin sulphate （25 μg）, doxycycline （30μg）, florfenicol （30 μg）, flumequine （30 lag）, nalidixic acid （30μg）, tetracycline （30μg）, oleandomycin （15μg）, fosfomycin （50μg）, and spiramycin （100 μg）, whereas heavy metal resistance profile of the present bacterial isolates was determined by 2-fold agar dilution technique. In this study, 5 types of bacteria were successfully isolated; they were Aeromonas spp. （n = 77）, Escherichia coli （n = 73）, Edwardsiella spp. （n = 62）, Salmonella spp. （n = 75）, and Vibrio spp. （n = 43）. The result showed that furazolidone was the most effective antibiotic to control the bacteria isolated in this study, approximately 89.7% of the bacterial isolates were sensitive to this antibiotic. Multiple antibiotic resistance （MAR） index indicated that the hatchery water source and M. rosenbergii post-larval and sediment tanks were at high-risk exposure to the tested antibiotic. Furthermore, all the tested heavy metals （Cd2＋, Cr6＋, Hg2＋, and Cu2＋） failed to inhibit the growth of the bacterial isolates. Therefore, it indicated that the water source of the hatchery is contaminated with both antibiotic residues and heavy metal.  相似文献   

3.
A total of 140 bacterial isolates have been successfully isolated from various organs of diseased American bullfrog （Rana catesbeiana） cultured in Malaysia. The most frequently isolated bacteria was Edwardsiella spp. （46 isolates） followed by Aeromonas spp. （33 isolates）, Flavobacterium spp. （31 isolates）, and Vibrio spp. （30 isolates）. Majority of the bacterial isolates were found sensitive to furazolidone （85.0%）, chloramphenicol （85.0%）, oxolinic acid （90.0%）, florfenicol （95.0%）, and flumequine （97.5%）. On the other hand, most of the bacterial isolates were resistant to oleandomycin （77.5%） and lincomycin （87.5%）. Nitrofurantoin and flumequine can be inhibited the growth of all of Vibrio spp. whereas all isolates of Edwardsiella spp. were found sensitive to florfenicol and flumequine. Multiple antibiotic resistance （MAR） index were in range of 0.30-0.40, indicating that bacterial isolates from cultured bullfrogs may have received high risk exposure to the tested antibiotics. In addition, 90-100% of the isolates were resistant to copper, cadmium, and chromium. These results provided insight information on tolerance level of bacterial isolates from cultured bullfrogs to 21 antibiotics as well as heavy metals.  相似文献   

4.
This paper compared antibiotic sensitivity between Vibrio spp. isolated from diseased postlarval and marketable-sized white leg shrimp (Litopenaeus vannamei). Recently, white leg shrimp become target species of shrimp culture among shrimp farmers in Malaysia to replace tiger shrimp (Penaeus monodon) culture. However, the baseline information on antibiogram of pathogenic bacteria especially Vibrio spp., the causative agent of vibriosis in white leg shrimp culture is not well established. Therefore, this study was conducted to reveal the antibiogram of Vibrio spp. isolated from diseased postlarval and marketable-sized white leg shrimp. The information gained from this study is useful for shrimp farmers in selecting appropriate antibiotic during disease outbreak. Antibiogram of present bacterial isolates was determined through disk diffusion method against 21 antibiotics (oxolinic acid 2 μg, ampicillin 10 μg, erythromycin 15 μg, furazolidone 15 μg, lincomycin 15 μg, oleandomycin 15 μg, amoxicillin 25 μg, colistin sulphate 25 μg, sulphamethoxazole 25 μg, chloramphenicol 30 μg, doxycycline 30 μg, florfenicol 30 μg, flumequine 30 μg, kanamycin 30 μg, nalidixic acid 30 μg, novobiocin 30 μg, oxytetracycline 30 μg, tetracycline 30 μg, nitrofurantoin 50 μg, fosfomycin 50 μg, and spiramycin 100 μg). A total of 47 Vibrio spp. isolates (Vibrio parahaemolyticus, 24, and V. alginolyticus, 23) from postlarval white leg shrimp and 49 Vibrio spp. isolates (Vibrio parahaemolyticus, 13, Vibrio alginolyticus, 28, and luminous Vibrio parahaemolyticus, 8) from marketable-sized white leg shrimp were successfully identified. Results of antibiotic sensitivity test from the present study showed that more than 80% Vibrio spp. from diseased postlarval and marketable-sized white leg shrimp, respectively, were sensitive to 14 out of the 21 tested antibiotics. Vibrio spp. isolated from marketable-sized white leg shrimp were found more susceptible to the tested antibiotics than Vibrio spp. isolated from postlarval white leg shrimp. This was due to 100% sensitive case against eight antibiotics found among Vibrio spp. isolated from marketable-sized white leg shrimp, whereas only three antibiotics were found sensitive to all Vibrio spp. isolated from postlarval white leg shrimp. Furthermore, the multiple antibiotic resistance (MAR) index indicated that marketable-sized white leg shrimp were not under high risk exposure to the tested antibiotics. On the other hand, the postlarvae were highly exposed to the tested antibiotics.  相似文献   

5.
This paper describes the chemical composition and antimicrobial activity of the essential oil of Syzygium aromaticum against Vibrio spp. (n = 6), Edwardsiella spp. (n = 21), Aeromonas spp. (n = 2), Escherichia coli (n = 2), Flavobacterium spp. (n = 1), Salmonella spp. (n = 2), Streptococcus spp. (n = 1) and Pseudomonas spp. (n = 1) isolated from aquaculture sites as well as seven reference strains of bacteria, namely, Escherichia coli (ATCC 25922), Citrobacter freundii (ATCC 8090), Aeromonas hydrophila (ATCC 49140), Pseudomonas aeruginosa (ATCC 35032), Streptococcus agalactiae (ATCC13813), Edwardsiella tarda (ATCC 15947) and Yersinia enterocolitica (ATCC 23715). Nowadays, most antibiotics are no longer effective in controlling diseases in aquaculture, especially fish systemic bacterial diseases, due to increasing incidences of antibiotic resistance among pathogenic bacteria. Furthermore, many countries have banned antibiotics in aquaculture use due to public health concerns and environmental hazards. Therefore, this study was carried out to evaluate the potential of the essential oil of S. aromaticum as an alternate commercial antibiotic to antimicrobial agents against fish systemic bacteria in aquaculture. The essential oil of S. aromaticum was prepared using a steam distillation method, and the chemical composition was analysed using Gas chromatography-mass spectroscopy (GC-MS). Minimum inhibitory concentration (MIC) values of the essential oils against the tested bacteria were determined using the broth two fold micro dilution method, with kanamycin and eugenol as positive controls. The MIC values of the essential oil of S. aromaticum ranged from 0.015 μg·mL−1 to 0.062 μg·mL−1 against the tested bacterial isolates. A total of nine chemical compounds were detected in the essential oil, with eugenol (49.0%) and caryophyllene (7.5%) being the major compounds. The results of the present study indicate that the essential oil of S. aromaticum shows a huge potential to substitute commercial antibiotics as antimicrobial agents for aquaculture use.  相似文献   

6.
Aeromonas hydrophila isolates from clinical cases （n=43） were tested against 8 antimicrobial agents and typed by outer membrane protein （OMP） pattern by using sodium dodecyl sulfate gel electrophoresis. All isolates were resistant to ampicillin （MICs, ≥16 μg mL-1） and sulfamonomethoxine （MICs≥64 μg mLl）, but susceptible to norfloxacin （MICs,≤0.5 μg mL-1）. There was a high incidence of resistance to erythromycin （90.70%） and tylosin （93.02%）, while a low incidences of resistance to ciprofloxacin （2.33%）, enrofloxacin （2.33%） and florfenicol （4.65%）. Six different outer membrane protein patterns were found among 34 isolates by analyzing proteins in the range of 22 to 50 kDa, other than 9 isolates with their respective profiles. The strains with the similar OMP profiles had similar resistances. Compared with the other strains from the same OMP patterns, NB-1, A.Pun and MR-1 had lacked the proteins in the range of 30 to 45 kDa and their resistance to florfenicol substantially increased. It is speculated that the outer membrane protein changes might correlate with decreased susceptibility to florfenicol in the three strains. Some strains which showed completely identical OMP types had a little difference in their resistance to fluoroquinolones, indicating that there might be other factors that were involved in the antimicrobial resistance of A. hydrophila.  相似文献   

7.
通过添加不同浓度鱼粉,制成6组等脂等能的蛋白质梯度实验饲料(P1～P6),研究中成鱼阶段(初始体质量范围定义为100 g/只的个体)卵形鲳鲹对饲料中蛋白质的最适需求量。研究发现,随着饲料中蛋白质含量的升高(P1～P6),实验鱼的生长性能如增重率、蛋白质效率以及全鱼粗蛋白含量均呈现先显著升高(P0.05)而后逐渐平稳的趋势(P0.05),而饲料系数和摄食率呈现先显著降低(P0.05)而后轻微升高的趋势(P0.05)。折线回归模型拟合生长性能,计算中成鱼阶段卵形鲳鲹对饲料中蛋白质的最适需求量(质量分数)为49.75%。在获得蛋白质需求的基础上,通过添加不同水平的豆油,制成6组等氮的脂肪梯度实验饲料(L1～L6),研究中成鱼阶段卵形鲳鲹对饲料中脂肪的最适需求量。随着饲料中脂肪含量提高(L1～L6),卵形鲳鲹的增重率等生长性能呈现先显著升高后稳定的趋势(P0.05),而饲料系数和摄食率则呈现先显著降低后稳定的趋势(P0.05)。折线回归模型拟合生长性能,计算中成鱼阶段卵形鲳鲹对饲料中脂肪的最适需求量(质量分数)为12.20%～12.27%。  相似文献   

8.
摘要：该文通过水质理化因子监测、虾体和水体中可培养细菌和弧菌检测及高通量测序方法,系统解析过硫酸氢钾（PMS）干预下对虾养殖池塘水体环境指标和菌群结构的变化情况。结果表明：施用0.2 g/L PMS对对虾养殖水体中低含量氨氮也具有一定改善作用,泼洒PMS 24h和72h后的水温、溶解氧、pH、盐度、亚硝酸盐无显著差异。PMS泼洒后对虾肝胰腺内可培养细菌和弧菌数量分别由3.13×106 CFU/g和1.98×106 CFU/g降低至4.30×105 CFU/g和1.09×105 CFU/g,弧菌占比由63.36%降低至25.35%;水体中可培养细菌和弧菌数量分别由2.70×104 CFU/mL和6.00×103 CFU/m降低至8.50×103 CFU/mL和1.20×103 CFU/mL,弧菌占比由22.22%降低至14.11%,PMS可显著降低虾体和水体中可培养细菌数量及弧菌占比。对水体菌群结构进行高通量测序分析表明,放线菌门、拟杆菌门、蓝藻门和变形菌门为主要优势菌门,泼洒PMS前后（PB1/PA1）,腈基降解菌科、PeM15、DS001、Llumatobacteraceae、微杆菌科、红细菌科相对丰度显著升高（P<0.05）,巴纽尔斯菌科、腐螺菌科、Stappiaceae相对丰度显著降低（P<0.05）,对比泼洒PMS前后3天的变化趋势表明,泼洒PMS后池塘优势菌相对丰度发生显著变化且菌群结构PCoA指数偏离度较低。相关研究结果为评判PMS在水产养殖中的防控作用及其科学使用提供数据支撑。  相似文献   

9.
The presence of indigenous endophytic bacteria in tissue-cultured seedlings germinated from seeds of Zizyphus jujuba var. Fupingdazao was investigated using cultivation, light microscopy and scanning electronic microscopy (SEM). In addition, bacteria specific 16S rDNA PCR followed by denaturing gradient gel electrophoresis (DGGE) was used. No cultivable bacteria could be detected on plates or in liquid cultures. However, large quantities of endophytic bacteria in jujube seedlings were observed under the light microscope. The bacterial cells were round (measuring 1.5 μm–1.8 μm), short rods (2.2 μm − 2.9 μm × 1.1 μm − 1.9 μm) and rod shaped (3.7 μm − 4.4 μm × 1.6 μm − 1.9 μm). Rod-shaped bacterial cells (measuring 3.5 m−4.0 m × 1.5m−2.0 m) were observed by SEM as well. A 16S rDNA fragment of 1.5 kb could be amplified from the total DNA of seedlings of jujube using the bacterial primer pair 27F/1525R. The V3 fragment of 16S rDNA was separated by DGGE, and the 16S rDNA-PCR-DGGE showed that there were at least six dominant bands within the seedlings of Z. jujuba var. Fupingdazao. It can be concluded that endophytic bacteria that cannot be detected by cultivation are present with high densities in jujube seeds.  相似文献   

10.
从烟田烟青虫(Helicoverpa assulta)自然感病虫体上新分离鉴定一株球孢白僵菌Bb062,将其与已有的不同来源地和寄主的10株白僵菌(Beauveria spp.)一起,分别测定其对烟青虫3龄幼虫致病力以及烟青虫3龄幼虫感染高毒力白僵菌后体内保护酶活性的变化。结果表明,在供试的11个白僵菌菌株中,Bb062对烟青虫3龄幼虫毒力最高,10 d累计校正死亡率达91.07%,LT50(致死中时)为4.67 d,且与其他菌株差异显著。以孢子1.0×106、1.0×107和1.0×108个·m L-1悬浮液处理时,烟青虫3龄幼虫累计死亡率随菌液浓度的提高和接菌后时间的延长而增大,LC50(致死中浓度)为孢子1.82×107个·m L-1。烟青虫3龄幼虫感染球孢白僵菌后72 h,其体内超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性均表现出先急剧升高,再急剧下降的变化过程。在所测试的菌株中,Bb062菌株对烟青虫毒力最高,且能够显著抑制其体内保护酶活性,因此,该菌株具有作为烟青虫生防菌的应用潜力。  相似文献   

11.
热泉土壤来源的纤维素降解菌的分离与初步鉴定   总被引：2，自引：0，他引：2  
通过富集培养方法,从5份热泉土壤中筛选得到6株具有羧甲基纤维素(CMC)降解活性的菌株。采用原核生物保守16S r RNA核糖体基因序列分析,发现它们分别隶属于假单胞菌属、芽孢杆菌属和类芽孢杆菌属。在此基础上,对6株纤维素降解菌的生长温度、pH值、抗生素敏感性、盐离子耐受性以及羧甲基纤维素酶(CMCase)活力做了初步研究。结果表明,芽孢杆菌属的菌株WP-6和WP-3的CMCase活力最强,胞内酶活力最高达72.0 U·m L~(-1),假单胞菌株WP-2的CMCase活力最弱,胞内外酶活力均小于5.0 U·m L~(-1)。生理学结果显示,6个降解菌株都具有嗜热特点及不同程度的耐盐特性,给后续高温及盐离子耐受性纤维素酶开发提供了较好的材料。  相似文献   

12.
2015—2017年新疆动物源鼠伤寒沙门菌耐药性分析   总被引：1，自引：1，他引：0  
为完善新疆动物源鼠伤寒沙门菌耐药的相关数据,为多重耐药病源菌的防控提供依据,本研究检测了2015—2017年新疆不同动物源鼠伤寒沙门菌的流行情况、耐药特性及耐药基因携带率。对经选择性培养基和特异性PCR鉴定的不同动物源鼠伤寒沙门菌,通过琼脂稀释法进行环丙沙星等12种抗菌药物的最小抑菌浓度测定,同时采用PCR方法测定耐药基因在鼠伤寒沙门菌中的携带情况。结果表明:从不同动物中共分离获得162株鼠伤寒沙门菌,分离率由高到低依次为宠物(犬和猫)、猪、羊、牛和鸡;药敏试验显示,不同动物源鼠伤寒沙门菌对环丙沙星、氨苄西林、四环素和氟苯尼考的耐药率80.0%,未检出对阿米卡星和磷霉素耐药的耐药菌株。从不同动物源分离的162株鼠伤寒沙门菌中有159株菌为多重耐药菌株,占98.1%;不同动物源鼠伤寒沙门菌多重耐药均以CIP-AMP-TET-FFC-SMZ 5耐谱型为主。经耐药基因分析,不同动物源鼠伤寒沙门菌耐药基因检出率为6.8%～97.4%,未检出blaSHV、qnrD、rmtB和mcr-1基因。综上,鼠伤寒沙门菌在新疆不同动物中流行率高,耐药现象严重,多重耐药菌株较多且耐药基因携带率高,部分不同动物源菌株间具有相同的耐药表型和耐药基因型。应加强畜牧业抗菌药物使用的管理制度,进而控制鼠伤寒沙门菌耐药性的发展趋势。  相似文献   

13.
In this study growth and yield response of wheat crop to phosphobacterium inoculum was observed under sandy loam conditions. The investigations were carried out at field experiment. The experiment was laid out in Randomized Complete Block Design. The treatments were; 120-0-0 NPK kg/ha−1 (T 1), 120-50-0 kg/ha−1 (T 2), 120-100-0 NPK kg/ha−1 (T 3), T 1 + Phosphobacterium inoculum (T 4), T 2 + Phosphobacterium inoculum (T 5) and T 3 + Phosphobacterium inoculum (T 6).The results showed that bacterial strain (Pseudomonas spp.) was able to effect on yield and its attributes in wheat crop. The crop showed significant positive results. The inoculation significantly stimulates the germination count (m−2), number of tillers and spikes (m−2), 1000 grains weight (g) and grain yield (kg/ha−1). We suggest that application of 120-100-0 kg/ha−1 NPK along with coating of seed with phosphobacterium (Pseudomonas spp.) all the way through inoculation is a better practice to reduce the exploit of phosphatic fertilizers which are much costly.  相似文献   

14.
【目的】了解广州市宠物源大肠埃希菌Escherichia coli耐药性和耐药基因携带情况。【方法】2016年7月至2017年7月从广州市4家宠物医院采集健康或患病犬猫样品共319份,其中,健康动物127份,患病动物192份。采用选择性培养基分离大肠埃希菌,利用基质辅助激光解析串联飞行时间质谱仪(MALDI-TOF MS)鉴定菌种;采用琼脂稀释法测定大肠埃希菌对11种抗菌药物的敏感性,利用PCR和测序检测耐药基因的携带情况。【结果】319份样品共分离得到大肠埃希菌203株,其中,患病动物源109株,健康动物源94株。203株大肠埃希菌中有179株至少对1种抗生素耐药;对氨苄西林耐药率最高(76.85%),对头孢噻肟、四环素、多西环素和磺胺甲噁唑-甲氧苄啶耐药率均高于50%;对阿米卡星最为敏感,耐药率仅为10.84%。患病动物源大肠埃希菌对11种抗菌药物的耐药率均高于健康动物源,除阿米卡星、氟苯尼考和磷霉素外,对其他药物的耐药性均差异极显著(P 0. 01)。耐药基因检测结果显示,floR检出率最高(检出率为34.97%),blaCTX-M-9G、blaCTX-M-1G、fos A3、rmt B和bla CMY-2检出率分别为22.66%、20.19%、17.73%、10.34%和1.48%,未检测到blaCTX-M-2G和blaCTX-M-25G。【结论】广州地区宠物源大肠埃希菌耐药状况严峻,且常携带多种重要耐药基因。应当加强对宠物源细菌耐药性的监测。  相似文献   

15.
研究了即食醉鱼制品的品质及微生物随贮藏时间的变化情况,并对潜在病原菌安全性进行评价。结果表明,产品水分含量、水分活度、pH值和盐分含量分别为(53.50±0.50)%、0.930 0±0.005 3、6.29±0.03和(4.33±0.07)%。菌落总数、耐热菌数和厌氧菌数在贮藏起始时分别为2.00×105、1.55×102和<100 cfu/g;进入贮藏期后4个月期间,菌落总数急剧下降,厌氧菌数和金黄色葡萄球菌均低于10cfu/g。在贮藏过程中各测试点菌落总数计数平板分离获得165株细菌,对其中157株进行分类鉴定。鉴定残存优势菌群为葡萄球菌84.8%,芽孢杆菌3.6%,李斯特菌6.7%,表明热杀菌强度不足。  相似文献   

16.
BALB/c mice were immunized with 50 μg, 100 μg, 200 μg of pcDNA-PRRSV-ORF5 DNA vaccine respectively by intramuscular injection, with PBS and pcDNA3.1(+) as controls. Fluorescence activated cell Sorter (FACS) was used to detect the number of CD4 + and CD8 + T-lymphocytes. T-lymphocyte proliferation test was used to detect proliferation of the T-lymphocyte cells in peripheral blood lymphocytes of mice vaccinated with pcDNA-PRRSV-ORF5 DNA vaccine. The results showed that the difference in ConA response to T-lymphocytes in blood was highly significant between all experimental groups and the control group (P < 0.01). The number of CD4 + T-lymphocytes in experimental groups was significantly higher than that of the control group 7 d after vaccination. The number of CD8 + T-lymphocytes in the experimental groups was higher than that of the control group 28 d after vaccination. Mice immunized with a higher dose (200 μg) of DNA vaccine demonstrated higher cellular immune response than those immunized with a lower dose (100 μg, 50 μg) of DNA vaccine. The results demonstrated that pcDNA-PRRSV-ORF5 DNA vaccine could induce a good cellular immune response which may be dose-dependent. __________ Translated from China J Vet Sci Mar, 2006, 26(2): 111–114 [译自: 中国兽医学报] The first three authors contribute equally to this work.  相似文献   

17.
A total of 241 Escherichia coli （E. coli） isolates from 349 avian samples （292 from cloacae, 29 from feed and water, 28 from dust and padding） were collected from Northeast, South, North, and Central China in recent years. The percentage of isolation was 69.1%. There are 67 serogroups each with 1-2 isolates distributed in different regions, and some of these regions had the preponderant serogroups. Antimicrobial-resistance （AR） of E. coli was so severe that the majority were multi-AR. Fifty percent strains were resistant to 10-19 antimicrobial drugs. Overall, the isolates represented resistance to nalidixic acid （88.1%）, tetracycline （85.7%）, sulfamethoxazole （81.0%）, trimethoprim-sulfamethpxazole （77.1%）, ampicillin （76.2%）, amoxilline （74.3%）, streplomycin （66.2%）, fluoroquinolones （57.1-66.7%）, chloramphenicol （52.9%）, gentamicin （39.0%）, and kanamycin （36.2%）. The isolates were sensitive to cefalexin, amoxilline-clavulanic acid, amikacin, and florfenicol with an AR rate of 0-19,5% only, The results showed that the AR was more severe in chicken farms in which the antibiotics were used broadly and repeatedly. This study indicated the AR characterization of E, coli in different areas of China. It will be a foundation for studying AR mechanism and regulating the usage of antimicrobial in the poultry industry.  相似文献   

18.
【目的】延长药物有效血药浓度的维持时间,产生持续稳定的抑菌作用,避免多剂量连续使用氟苯尼考产生胚胎毒性和免疫抑制。【方法】以硬化油、聚乙二醇、甘油酯为辅料,采用离心喷雾干燥制粒技术法制备氟苯尼考缓释颗粒,高效液相色谱法(HPLC)测定氟苯尼考含量。以药物在不同释放介质(pH 1.2盐酸缓冲液、pH 4.3醋酸缓冲液和pH6.8磷酸缓冲液)中的释放特性为指标,对氟苯尼考粉和自制的氟苯尼考缓释颗粒进行溶出试验,考察体外释放特性。【结果】4个批次制备的氟苯尼考缓释颗粒中氟苯尼考实际含量在标示含量中的占比分别为99.19%、100.01%、97.45%和100.72%,相对标准偏差(RSD)分别为0.82%、0.86%、0.77%和0.24%。氟苯尼考粉在0.25 h内完全释放,自制的氟苯尼考缓释颗粒在模拟胃液环境(pH 1.2盐酸缓冲液)基本不释放,在模拟肠液环境(pH 4.3醋酸缓冲液和pH6.8磷酸缓冲液)缓慢释放,5 h内释放量达95%以上。【结论】自制的氟苯尼考缓释颗粒中药物分布较均匀,符合中国兽药典要求。相比于氟苯尼考粉,氟苯尼考缓释颗粒表现出良好的耐酸性体外缓释性,可为后续的临床试验研究和临床使用药物提供参考依据。  相似文献   

19.
The pathogenicity of 36 isolates of Xanthomonas oryzae pv. oryzae （Xoo）, which were collected from japonica rice varieties in the Yunnan Plateau, China, was evaluated. It was evaluated on 29 rice varieties including a set of seven varieties to identify pathogenicity, i.e., Haonuoyang, TN1, Kogyoku, Zhenzhu＇ai, IR26, Nanjing 33, and Kinmaze, which may be considered as a set of differential varieties for Xoo races from Yunnan japonica rice. The efficiency of the seven varieties was further confirmed. The results showed reversible and specific interactions between isolates and varieties. The isolates were classified into nine pathotypes from pathotyp Ⅰ to Ⅸ according to their pathogenic reactions on the seven rice varieties. The pathotype V was the epidemic, whereas pathogen Ⅶ was the most pathogenic. Most japonica varieties grown in the Yunnan Plateau were susceptible to Xoo. The rice lines IRBB21 （Xa-21）, Zhachanglong （Xa-22,, Xa- 24,）, and IR1545-339 （xa-5）, which were resistant to all the isolates tested, can be used as donors of resistant genes for bacterial blight in japonica rice breeding in the Yunnan Plateau.  相似文献   

20.
为明确安徽省淮南市地区酥瓜果实斑点病的病原菌,采用常规平板划线法从酥瓜果实病组织分离细菌,通过生理生化特征、分子生物学特性和致病性试验对其进行鉴定.结果表明,从采集的病果中获得36株菌落形态特征相似的细菌分离物,测试菌株均能诱导烟草叶片产生过敏性坏死.采用牙签刺伤法将测试菌株接种健康酥瓜果实,可导致接种点处产生水浸状病斑.BLAST结果表明,2株菌株的16S rRNA序列分别与短小芽胞杆菌Bacillus pumilus GR-8(CP009108),ATCC 7061(ABRX01000003)的同源性为99.93％和99.58％,2株菌株的 gyrB 基因序列与 B.pumilus C4(CP011109)的同源性达99.39％.基于gyrB基因的聚类分析证实2株菌株与B.pumilus(C4和GR-8)紧密的聚在一个分支.生理生化试验结果进一步显示,该细菌与文献报道的短小芽胞杆菌的生理生化特征相吻合.结合细菌生理生化特征、16S rRNA和gyrB基因的序列分析,以及柯赫氏法则验证,确定引起酥瓜果实细菌性斑点病的病原为B.pumilus.  相似文献   

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