Isolation,identification and pathogenicity of Vibrio harveyi,the causal agent of skin ulcer disease in juvenile hybrid groupers Epinephelus fuscoguttatus × Epinephelus lanceolatus          下载免费PDF全文

G M Shen  C Y Shi  C Fan  D Jia  S Q Wang  G S Xie  G Y Li  Z L Mo  J Huang 《Journal of fish diseases》2017,40(10):1351-1362

The hybrid grouper, Epinephelus fuscoguttatus (♀) × Epinephelus lanceolatus (♂), is a newly bred cultivated marine fish species of high economic value. However, a skin ulcer disease with high mortality has occurred, and the responsible pathogen remains unknown. In this study, we summarized the epidemic status and external signs of this disease. We screened potential pathogens and finally isolated one bacterial strain ML01 from affected fish. We subjected healthy juvenile hybrid groupers to bacterial challenge tests with the isolate by immersion, immersion after dermal abrasion and intraperitoneal injection, respectively. Within 14 days post‐infection, the isolate ML01 caused mass mortality of juveniles infected via immersion after dermal abrasion or intraperitoneal injection. Diseased juveniles displayed obvious signs of skin ulcers. The median lethal dose of ML01 by intraperitoneal injection was 1.10 × 10⁵ colony‐forming units. ML01 was identified as Vibrio harveyi by bacterial morphology, analytical profile index identification, 16S rDNA sequencing and multilocus sequence analysis. Antibiotic susceptibility tests showed that ML01 was sensitive to ceftriaxone, doxycycline and minocycline. The results of this study suggest that V. harveyi is the causal agent of skin ulcer disease in juvenile hybrid groupers, thus providing a basis for effective control and prevention of this disease.  相似文献   

Adsorption of the antibiotic pharmaceutical compound sulfapyridine by a long‐term differently fertilized loess Chernozem     

Sren Thiele 《植物养料与土壤学杂志》2000,163(6):589-594

Residues of antibiotic pharmaceutical compounds (APCs) found in the environment are suspected to be translocated into the food chain and to provoke the formation of resistant microorganisms. However, the behavior of APCs in soils is largely unknown. In the present study batch experiments were carried out with sulfapyridine (SPY) and p‐aminobenzoic acid (ABA) amended to two loess Chernozem samples. Due to different fertilization in the course of a long‐term field experiment samples differed substantially in the concentration of organic carbon (C_org 1.6 and 2.4%) and composition of soil organic matter (SOM). APCs in soil extracts were analyzed by high performance liquid chromatography. The K_F values of the Freundlich isotherm for SPY were 2.2 (1.6% C_org) and 5.5 (2.4% C_org). The K_oc values were 101 and 308. The different K_oc values indicated that not only the quantity but also the composition of SOM affected the SPY adsorption. Adsorption of SPY was substantially higher in moist than in air‐dry soil. ABA, consisting of a carboxyl group instead of the sulfonamide group substituted with a N‐heterocycle, was much less adsorbed than SPY (K_F 0.2). From this it was concluded that the N‐heterocycle significantly contributed to the adsorption of SPY.  相似文献   

两种抗生素对亚心形扁藻生长的影响   总被引：2，自引：0，他引：2  

赵素芬  叶颂伟  孙会强 《水产科学》2005,24(8):29-31

在室温下,研究了不同浓度的土霉素和氯霉素对亚心形扁藻细胞的数量、大小以及叶绿素、类胡萝卜素含量等方面的影响。结果表明:在0~5mg/L范围内,土霉素的浓度越大,细胞数量在增长期内增幅越大,在衰退期内衰退越快;土霉素对色素含量有不同程度的促进作用。氯霉素浓度>1mg/L时,浓度越大,扁藻细胞数量增幅越小,类胡萝卜素越多。土霉素,氯霉素对扁藻细胞大小的影响均不明显。  相似文献   

生猪废水处理和磷回收工艺中抗生素和耐药细菌的削减特征   总被引：1，自引：0，他引：1  

王蕾  黄栩 《农业现代化研究》2021,42(2):254-262

调查生猪废水处理和磷回收工艺中,厌氧消化、氧化池、磷回收流化床和潜流人工湿地对水质参数、抗生素、耐药细菌和病原菌丰度削减的贡献。结果表明,在水质指标方面,厌氧消化对COD的去除率最大,为40.28%;人工湿地对TP和NH_4~+-N的去除率最大,分别达到53.33%和67.74%;流化床对TP的去除率为49.94%。在抗生素吸附和降解方面,厌氧消化、流化床和人工湿地对土霉素(OTC)和环丙沙星(CIP)具有较大幅度的去除,去除率范围分别为32.27%～63.77%和40.44%～44.11%;厌氧消化、氧化池和人工湿地对磺胺二甲嘧啶(SM2)具有中等幅度的去除,去除率范围为18.10%～28.52%。在耐药细菌方面,厌氧消化作为一级处理工艺对各类型耐药细菌均具有最大去除率(50%);同样作为三级处理工艺,人工湿地能进一步削减耐药细菌的数量,而流化床出水中以奇异变形杆菌、鼠伤寒沙门氏菌和宋内氏志贺氏菌为主的耐药细菌数量出现反弹。微生物群落分析发现,人工湿地在降低病原细菌丰度方面优势显著。研究表明,设置潜流人工湿地承接流化床出水可进一步深化处理生猪废水。  相似文献   

Molecular epidemiology,characterization of virulence factors and antibiotic resistance profile of Streptococcus agalactiae isolated from dairy farms in China and Pakistan          下载免费PDF全文

《农业科学学报》2023,22(5):1514-1528

Streptococcus agalactiae is one of the most common pathogens that cause bovine mastitis worldwide. Identifying pathogen prevalence and virulence factors is critical for developing prevention and control approaches. Herein, 1 161 milk samples from various dairy farms in China (n=558) and Pakistan (n=603) were collected between 2019–2021 and were subjected to S. agalactiae isolation. Prevalence, serotyping, virulence genes, and antibiotic-resistant genes of S. agalactiae were evaluated by PCR assay. All isolates were characterized for haemolysis, biofilm production, cytotoxicity, adhesion, and invasion on bovine mammary epithelial cells. The prevalence of S. agalactiae-induced mastitis in cattle was found to be considerably higher in Pakistan than in China. Jiangsu and Sindh provinces had the highest area-wise prevalence in China and Pakistan, respectively. Serotypes Ia and II were prevalent in both countries, whereas serotype III was found only in Pakistan. Moreover, all isolates tested positive for PI-2b gene but negative for PI-1 and PI-2a genes. All isolates harboured cfb, cylE, hylB, and fbsB virulent genes, whereas many of them lacked bibA, rib and bca. However, the absence of bac and scp genes in Chinese isolates and cspA in Pakistani isolates was noted, while spb1 and lmb were not detected in isolates of both countries. Pakistani isolates, particularly serotype Ia-positive, had a considerably higher ability to produce biofilm, haemolysis, cytotoxicity, adhesion, and invasion than Chinese isolates. Most of the isolates were phenotypically resistant to tetracycline, erythromycin, and clindamycin and genotypic resistance was confirmed by the presence of ermA, ermB, tetM and tetO genes. Our study highlights the antimicrobial resistance profile and virulence-related factors contributing to the epidemiological spread of mastitis-causing S. agalactiae in China and Pakistan. The findings may facilitate future studies designed to develop improved treatment and control strategies against this pathogen.  相似文献   

4种水生植物对兽用抗生素去除效果比较          下载免费PDF全文

周品成  刘希强  康兴生  林云琴  王德汉  崔理华 《华南农业大学学报》2019,40(6):67-73

【目的】降低生活污水和畜禽养殖废水中兽药抗生素残留污染,为植物修复和人工湿地筛选较优去除兽用抗生素植物。【方法】选择4种常见水生植物(皇竹草Pennisetum hydridum、风车草Cyperus alternifolius、美人蕉Canna indica和梭鱼草Pontderia cordata)和3种常用兽药抗生素(阿莫西林、氟苯尼考和盐酸多西环素)构建水培试验体系,研究不同水生植物对水体环境中抗生素耐受性及去除效果。【结果】水培14 d后,4种供试植物对水体环境中的3种抗生素都有一定的去除能力,并且表现出抗生素低、中质量浓度(0～100μg/L)对植株株高和叶绿素含量具有促进作用,均高于对照;高质量浓度(大于100μg/L)则抑制生长,植株株高和叶绿素含量显著小于对照处理。100μg/L抗生素胁迫14 d后,各植株的去除效率最高,其中,对阿莫西林、氟苯尼考和盐酸多西环素去除效率最好的供试植物种类分别为皇竹草、美人蕉和美人蕉,去除效率分别为55.0%、56.2%和48.3%。【结论】在去除水体环境中的兽用抗生素时,本研究中4类植物对抗生素去除效率为美人蕉皇竹草梭鱼草、风车草。  相似文献   

黄铁矿光降解泰乐菌素及干扰因素影响机制          下载免费PDF全文

康晓跃  周进文  李赵芮  李彦盼  鄢顺意  舒小华  张倩 《农业环境科学学报》2022,41(3):606-615

为探讨不同环境条件对黄铁矿（FeS₂）光催化降解抗生素的影响，推进FeS₂光催化的实际应用，实验研究了pH值、水中NO₃^-和H₂PO₄^-对FeS₂光降解泰乐菌素（Tylosin，TYL）的影响机制，考察了FeS₂重复利用的光催化效果并深入分析了FeS₂光降解过程中的自由基贡献。结果表明：天然FeS₂能够在1 h内快速光降解TYL（降解率为97%）。FeS₂光催化过程中产生·OH、·O₂^-及h⁺，对TYL的光降解起主要作用的是·OH和·O₂^-。FeS₂使水溶液pH维持在酸性条件，导致初始溶液pH对FeS₂光降解TYL影响较小。水环境中NO₃^-可以吸收光能产生·OH，促进TYL的光降解。不同浓度H₂PO_-4对溶液pH的影响及Fe³⁺水解胶体的絮凝作用导致不同浓度H₂PO₄^-对FeS₂光降解TYL产生不同影响。FeS₂重复利用4次后，仍能够保持80%的光降解效率。研究表明，利用FeS₂去除抗生素具有实际应用价值，FeS₂的光催化效果与污水的pH值、NO₃^-和H₂PO₄^-浓度密切相关。  相似文献   

食源性致病细菌在土壤中的生存策略及其治理方式   总被引：1，自引：1，他引：0       下载免费PDF全文

杨埔  鞠峰  张丽珍 《农业环境科学学报》2022,41(12):2694-2704

土壤健康，特别是农业土壤的健康，与食品安全密切相关。然而，目前在土壤中已检出了大肠杆菌、肠沙门氏菌、单核增生李斯特氏菌等食源性致病细菌。某些食源性致病细菌能适应土壤中生物与非生物环境并可长期存活，其毒力基因与抗生素抗性基因可能会通过食物链传播，从而给土壤环境生物安全与消费者健康带来风险。本文综述了土壤中食源性致病细菌的主要来源及其生存策略，并介绍了源头治理和原位修复的方法。在此基础上，对土壤中食源性致病细菌治理的技术策略进行了展望，并从改善土壤化学环境和物理环境、切断传播途径、生物防治等方面讨论了未来研究重点关注的方向，以期为保障土壤健康和食品安全提供新思路。  相似文献   

亚成体胡兀鹫肠道菌群分离及生物特性分析          下载免费PDF全文

陈含西  宋嘉慧  郑思思  李季  王稳  朱丽琳 《现代农业科技》2023,(2):164-169+173

为探究胡兀鹫肠道菌群多样性，本研究利用5种培养基进行胡兀鹫肠道菌分离、培养、鉴定、耐药性试验及抑菌测定。结果表明：共分离到27株肠道菌，隶属于2门8属12种；这些菌株对3～22种抗生素及抗菌药物具有耐药性；屎肠球菌对5种常见肠道致病菌具有一定的抑制作用，粪肠球菌仅对大肠杆菌有抑制效果。  相似文献   

1株鹅源类志贺邻单胞菌的分离鉴定及致病性研究     

康宇晖  周洪善  金文杰  秦爱建 《中国畜牧兽医》2022,49(9):3676-3682

【目的】 查明江苏某鹅场鹅发病及死亡原因。【方法】 剖检病死鹅，运用细菌分离纯化、染色观察、生化试验、基质辅助激光解析电离飞行时间质谱（MALDI-TOF MS）鉴定、16S rDNA测定方法进行病原菌分离鉴定，通过药敏试验和小鼠致病性试验探究分离菌株的特性。【结果】 从患病鹅肝脏分离到1株革兰氏阴性短杆状细菌；生化试验结果显示，此菌株可发酵葡萄糖、麦芽糖、枸橼酸盐、尿素；MALDI-TOF MS鉴定结果显示，此菌株为类志贺邻单胞菌；16S rDNA序列对比分析发现，分离菌与类志贺邻单胞菌相似性最高，达98%以上；药敏试验结果显示，分离菌对左氧氟沙星、美罗培南、头孢西丁、庆大霉素等10种抗菌药敏感，对四环素、头孢吡肟、头孢他啶、头孢唑林表现为中介，对阿奇霉素、复方新诺明、氨苄西林等6种药物表现为耐药，是典型的多重耐药菌；小鼠致病性试验结果显示，分离菌对小鼠的半数致死量为5.0×10^6.5 CFU。【结论】 本试验首次报道了从鹅体内分离到致病性类志贺邻单胞菌，通过药敏试验筛选了左氧氟沙星、美罗培南、头孢西丁等有效的临床常用抗菌药，分离株对小鼠致病性较强，提示其带来的潜在风险不可忽视。  相似文献