肉仔鸡红霉素中毒的诊治

在肉仔鸡实际生产中，常用红霉素饮水口服预防、治疗呼吸道感染疾病。不少养鸡户对药物的常规知识缺少全面的了解，特别是超限加大用药剂量，造成中毒的现象时有发生。现将一例肉仔鸡红霉素中毒的诊治过程报告如下：     

红霉素硫氰酸盐水溶剂饲喂试验

用红霉素硫氰酸盐水溶剂作肉鸡饲料添加剂,在生产现场条件下,观察该药物的安全性以及促生长、防病作用。 一、材料与方法 (一)药物:红霉素硫氰酸盐水溶剂(下称红霉素水溶剂),上海第二制药厂研制,批号:9002001,红霉素含量5％。 (二)动物:1日龄AA肉鸡1000羽,购自上海县梅陇种禽场。在梅陇陇西大队饲养场饲养。出壳第二天分组,并开始试验。试验过程中于10日龄接种鸡新城疫疫苗、鸡痘疫苗;17日龄接种法氏囊疫苗;30日龄复种鸡新城疫疫苗。饲料系大江公司311、312肉鸡料。 (三)分组及处理:分为四组。各组鸡均在同一间饲养棚中分组饲喂。记录各组情况,于第46天称重。试验自1990年2月22日起至4月7日止。 第一组:260羽。饮水中含红霉素水溶剂125-31.2ppm(前20天125ppm,后25天31.2ppm),连续45天;     

影响氨茶碱药代动力学的药物因素

影响氨茶碱药代动力学的药物因素王晖（综述）孙瑞元审校）广东医学院药理学教研室，湛江５２４０２３皖南医学院药理学教研室氨茶碱是茶碱与乙二胺的复盐，因其具有松驰支气管平滑肌的作用，常用于治疗支气管哮喘，但其治疗指数较窄。支气管哮喘患者，如伴发其它疾病，常...     

鹦鹉新城疫的诊治

1 发病情况我市某鹦鹉饲养场饲养鹦鹉1 200只,2004年8月发病,最初是10多只,3天后迅速扩大到235只,并且相继出现死亡.整个病程持续7天,共发病531只,发病率达44.3%.死亡329只,病死率为62%.先后用红霉素、土霉素、磺胺类药物等治疗,但效果不理想。     

用新型分子模版吸附树脂从发酵液中分离红霉素的研究

采用新型分子模版吸附树脂动态吸附、丙酮解吸、水稀释结晶和丙酮重结晶等流程,从红色链霉菌发酵滤清液中分离红霉素,研究影响吸附分离效率的各种因素,并与现行醋酸丁酯萃取生产流程比较。结果显示,改性LX-18树脂对红霉素的吸附量达130 ku/mL,对发酵液中色素的选择分离率>95%,红霉素浓度120~150 ku/mL的丙酮解吸液采用水稀释结晶,再用丙酮重结晶,即获得各项理化指标达药典标准的红霉素。结晶母液须2次吸附回收,红霉素总收率为60%~62%。本工艺具有简便、分离成本较低和减轻废水污染的特点。     

应用高效液相色谱法对饲料中五种抗生素的同时检测

本试验建立了同时测定饲料中5种抗生素含量的高效液相色谱法。试验采用梯度洗脱,使金霉素、氯霉素、红霉素、罗红霉素、青霉素得到较好的分离;柱温30℃,流速为1．0mL／min,进样量20μL,检测波长210nm。结果显示,金霉素、氯霉素、青霉素标准曲线线性范围为0．5～40μg／mL,红霉素、罗红霉素标准曲线线性范围为0．5～80μg／mL,相关系数r≥0．9997。饲料中5种抗生素的加样回收率为95．86％-98．72％,RSD〈2％。本试验建立的梯度洗脱方法简便快速,准确度和精密度较高,可以满足饲料中CTC、CPA、ERY、Rox、PG的检测。     

Erythromycin Resistance of Streptococcus suis Isolates In Vivo

In order to study erythromycin resistance of Streptococcus suis under high or low concentration of selective drug pressure, Streptococcus suis strain LN was isolated from a diseased pig in 2005 and showed to be susceptible to erythromycin as determined by disc diffusion and tube dilution tests. In this study, clean level rabbits were divided into three groups of six rabbits each, including a prevention dosage group, a treatment dosage group, and a control group. After injection with S. suis strain LN, erythromycin （20 μg mL^-1） was taken orally in the prevention dosage group, erythromycin （5 mg kg^-1） was injected intramuscularly in the treatment dosage group, and no treatment was given in the control group. S. suis with intermediate resistance to erythromycin was isolated on the 5th day after infection from the prevention dosage group （5th PDG） and on the 7th day after infection from the treatment dosage group （7th TDG）. Both isolates were determined to be the constitutive macrolide-lincosamide-streptogramin B （cMLSB） resistance phenotype. The resistance gene ermB was detected in all of the isolates. The results suggested that both the 5th PDG and 7th TDG isolates had a mutation （A2372T） in the 23S rRNA gene. In addition, the 5th PDG isolates had a mutation in ribosomal protein L4 （detected as G268A） and a mutation in ribosomal protein L22 （A345C）; and the 7th TDG isolates had a C insertion at site 564. Each of these mutations is considered as a possible mechanism of erythromycin resistance in S. suis strain LN. This study demonstrated that erythromycin resistance was readily induced in S. suis at a low erythromycin dose creating selective pressure in vivo. Resistance appeared to be mediated by ribosome methylation, encoded by the ermB gene.