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1.
OBJECTIVE: To determine the prevalence of Streptococcus iniae in tilapia (Oreochromis spp), hybrid striped bass (Morone chrysops X M saxatilis), and channel catfish (Ictalurus punctatus) on commercial fish farms in the United States. ANIMALS: 1,543 fish (970 tilapia, 415 hybrid striped bass, and 158 channel catfish). PROCEDURES: The dry-swab technique was used for collection of specimens for streptococcal isolation. Specimens were shipped by overnight delivery and processed by use of standard bacteriologic techniques. RESULTS: Streptococcus iniae was not isolated from market-size channel catfish. Prevalence in tilapia and hybrid striped bass was 37 of 970 (3.81%) and 30 of 415 (7.23%), respectively. Prevalence by farm ranged from 0.0 to 27.4% for tilapia and 0.0 to 21.6% for hybrid striped bass. In tilapia, prevalence was lowest in market-size and nursery fish (4 of 239 [1.67%] and 3 of 339 [0.88%], respectively), with an increase in prevalence for fish in the grow-out stage (30 of 337 [7.96%]). For hybrid striped bass, prevalence was lowest in nursery and market-size fish (3 of 96 [3.12%] and 1 of 47 [2.12%], respectively) and highest in fish in the grow-out stage (26 of 272 [9.56%]). Prevalence in market-size tilapia and hybrid striped bass was 5 of 286 (1.75%). CONCLUSIONS AND CLINICAL RELEVANCE: Results of this study do not support the contention that S iniae is a serious public health threat associated with commercially raised fish; rather, it represents a limited risk for older or immunocompromised people who incur puncture wounds while handling and preparing fish.  相似文献   

2.
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3.
Abstract

Blood chemistry analytes are determined for fish from either serum or plasma samples. Serum and plasma are similar in that they both represent the fluid component of blood; however, plasma contains clotting factors that are not present in serum. This study was conducted to determine whether the type of sample—plasma or serum—had an effect on measured blood analytes in rainbow trout Oncorhynchus mykiss, channel catfish Ictalurus punctatus, hybrid tilapia Oreochromis spp., and hybrid striped bass (striped bass Morone saxatilis × white bass M. chrysops). Paired plasma and serum samples were analyzed for the following standard biochemical analytes: total protein, albumin, globulin, creatinine, total bilirubin, alkaline phosphatase, aspartate aminotransferase, sodium, potassium, chloride, calcium magnesium, phosphorus, glucose, and cholesterol. For all four taxa, values for potassium were lower in the serum and magnesium and phosphorus values were higher in the serum. Glucose values were lower in the serum from rainbow trout, hybrid striped bass, and channel catfish; whereas cholesterol values were higher in the serum of rainbow trout, channel catfish, and hybrid tilapias. The differences observed between serum and plasma were distinct from changes occurring with hemolysis and, therefore, do not represent release of erythrocyte constituents. The differences most likely represent metabolic utilization of blood constituents while the blood was clotting. This work indicates that plasma should be used preferentially to serum for biochemical analysis because analyte levels determined from serum may not accurately reflect those found in circulating blood.  相似文献   

4.
Nile tilapia Oreochromis niloticus, summer flounder Paralichthys dentatus, and walleyes Sander vitreus were treated with Romet-30 (PHARMAQ AS, Oslo, Norway) via a medicated ration at 50 mg Romet-30 kg fish body weight(- 1) d(-1) for 10 d to compare the elimination kinetics of the test substance. This study was part of a larger effort to develop a species grouping concept for the labeling of therapeutic compounds for cultured fishes. The fish tests were conducted at the ideal water temperature for each species and at 5 degrees C lower than the ideal temperature except for summer flounder, which would not feed at the lower temperature of 15 degrees C. Test temperatures were 30 degrees C and 25 degrees C for Nile tilapia, 20 degrees C and 17 degrees C for summer flounder, and 25 degrees C and 20 degrees C for walleyes. Neither component of Romet-30 (sulfadimethoxine and ormetoprim) could be detected in samples of the edible portion of walleyes (muscle plus skin) collected at day 10 posttreatment or thereafter. In studies with summer flounder, only one fish had a detectable concentration of either component on day 21 or thereafter. Elimination of Romet-30 by Nile tilapia was extremely rapid. The limited number of Nile tilapia with detectable sulfadimethoxine or ormetoprim during the posttreatment period prevented the determination of elimination half-life or elimination in this species.  相似文献   

5.
Defining pharmacokinetic parameters and depletion intervals for antimicrobials used in fish represents important guidelines for future regulation by Brazilian agencies of the use of these substances in fish farming. This article presents a depletion study for oxytetracycline (OTC) in tilapias (Orechromis niloticus) farmed under tropical conditions during the winter season. High performance liquid chromatography, with fluorescence detection for the quantitation of OTC in tilapia fillets and medicated feed, was developed and validated. The depletion study with fish was carried out under monitored environmental conditions. OTC was administered in the feed for five consecutive days at daily dosages of 80 mg/kg body weight. Groups of ten fish were slaughtered at 1, 2, 3, 4, 5, 8, 10, 15, 20, and 25 days after medication. After the 8th day posttreatment, OTC concentrations in the tilapia fillets were below the limit of quantitation (13 ng/g) of the method. Linear regression of the mathematical model of data analysis presented a coefficient of 0.9962. The elimination half-life for OTC in tilapia fillet and the withdrawal period were 1.65 and 6 days, respectively, considering a percentile of 99% with 95% of confidence and a maximum residue limit of 100 ng/g. Even though the study was carried out in the winter under practical conditions where water temperature varied, the results obtained are similar to others from studies conducted under controlled temperature.  相似文献   

6.
本研究通过建立人肝微粒体体外孵育试验，考察泰妙菌素对4种CYP450亚酶的探针底物睾酮、非那西丁、氯唑沙宗、氢溴酸右美沙芬代谢的影响，以反映泰妙菌素对人CYP3A4、CYP1A2、CYP2E1、CYP2D6酶活性的作用。试验分为3组：药物试验组、阳性对照组（不含NADPH）、阴性对照组（不含CYP450抑制剂），孵育体系为100 μL，孵育试验在96孔板中进行。终止反应后使用高效液相色谱串联质谱仪（LC-MS/MS），以内标法检测96孔板中孵育液的剩余探针底物浓度。根据药物试验组与阴性对照组的探针药物代谢浓度之比，计算药物试验组的探针药物代谢率。使用Graphpad Prism 6.0软件，以药物试验组相对代谢率为纵坐标，药物浓度对数值为横坐标作图，计算试验组药物IC50值。针对泰妙菌素与CYP3A4的孵育试验设置多个孵育时间点观察孵育时间对IC50值的影响。试验结果显示，酮康唑对CYP3A4的IC50值为0.044 μmol/L，α-萘黄酮对CYP1A2的IC50值为0.030 μmol/L、4-甲基吡唑对CYP2E1的IC50值为0.022 μmol/L、奎尼丁对CYP2D6的IC50值为0.096 μmol/L。泰妙菌素对CYP1A2及CYP2D6的IC50值均大于50 μmol/L，对CYP2E1的IC50值为0.045 μmol/L，对CYP3A4的IC50值为1.609 μmol/L。延长泰妙菌素与CYP3A4的孵育时间（10~50 min）后，泰妙菌素对CYP3A4的IC50值由1.609 μmol/L增加至 8.657 μmol/L。本研究中4种亚酶常用抑制剂的IC50值与参照值相近，表明所建立人肝微粒体体外孵育试验方法可靠。以IC50值为指标显示泰妙菌素对CYP1A2和CYP2D6无抑制作用，对CYP2E1和CYP3A4存在强抑制作用，泰妙菌素可能是CYP3A4的可逆性抑制剂。  相似文献   

7.
Cytochrome P450 (CYP) is important for metabolism of not only xenobiotics such as drugs, but also endogenous compounds including arachidonic acids. CYP4A11, CYP4F3v2, CYP4F11, and CYP4F45 have been identified in cynomolgus macaque, an animal species widely used for investigation of drug metabolism due to its evolutionary closeness to human. However, their metabolic functions have not been investigated. In this study, proteins were heterologously expressed in Escherichia coli and characterized by metabolic assays using arachidonic acids as substrates that are metabolized by CYP4 isoforms in human. The results showed that all four CYPs metabolized arachidonic acids. Therefore, cynomolgus macaque CYP4A11, CYP4F3v2, CYP4F11, and CYP4F45 are functional enzymes.  相似文献   

8.
A comparative pharmacokinetic study was conducted in rainbow trout (Salmo gairdneri) and African catfish (Clarias gariepinus) following intravenous (i.v.) and intramuscular (i.m.) administration of oxytetracycline (OTC) at a dose rate of 60 mg/kg body weight. Trout and catfish were kept in aerated tap water in tanks at constant temperatures of 12 degrees C and 25 degrees C, respectively. The two- and three-compartment open models adequately described plasma drug disposition in African catfish and rainbow trout respectively, following i.v. OTC administration. Compared to catfish (COP = 86 +/- 10 micrograms/ml) an eightfold higher extrapolated zero time concentration was obtained in trout (COP = 753 +/- 290 micrograms/ml). A significant difference was observed with respect to the relatively large apparent distribution volumes (Vd(area] after i.v. OTC administration (trout, mean value: 2.1 l/kg; catfish, mean value: 1.3 l/kg). The mean final elimination half-lives of both fish species were greater than previously reported in mammals (trout, 89.5 h; catfish, 80.3 h). A mean maximum plasma concentration (Cmax = 56.9 micrograms/ml) was obtained in trout at 4 h after i.m. administration of OTC. In catfish a lower Cmax of 43.4 micrograms/ml was determined at about 7 h. No significant difference was observed with respect to bioavailability following i.m. administration of OTC (trout, 85%; catfish, 86%).  相似文献   

9.
Cytochromes P450 (P450) are important for not only drug metabolism and toxicity, but also biosynthesis and metabolism of cholesterol and bile acids, and steroid synthesis. In cynomolgus macaques, widely used in biomedical research, we have characterized P450 cDNAs, which were isolated as expressed sequence tags of cynomolgus macaque liver. In this study, cynomolgus CYP7A1, CYP17A1, CYP20A1, CYP27A1 and CYP51A1 cDNAs were characterized by sequence analysis, phylogenetic analysis and tissue expression pattern. By sequence analysis, these five cynomolgus P450s had high sequence identities (94–99%) to the human orthologs in amino acids. By phylogenetic analysis, each cynomolgus P450 was more closely related to the human ortholog as compared with the dog or rat ortholog. By quantitative polymerase chain reaction, among the 10 tissue types, CYP7A1 and CYP17A1 mRNAs were preferentially expressed in liver and adrenal gland, respectively. Cynomolgus CYP27A1 and CYP51A1 mRNAs were most abundantly expressed in liver and testis, respectively. Cynomolgus CYP20A1 mRNA was expressed in all the tissues, including brain and liver. Tissue expression patterns of each cynomolgus P450 were generally similar to that of the human ortholog. These results suggest the molecular similarities of CYP7A1, CYP17A1, CYP20A1, CYP27A1 and CYP51A1 between cynomolgus macaques and humans.  相似文献   

10.
曹威荣 《中国饲料》2022,1(4):69-72
本试验研究在饲料中添加微藻对尼罗罗非鱼幼鱼的生长性能及体成分的影响,在基础饲料中分别添加不同微藻,分成5个组进行饲喂,其中D0组为对照组,不添加任何微藻,D1组添加7.5％螺旋藻,D2组添加15％螺旋藻,D3组添加7.5％栅藻,D4组添加15％栅藻.结果表明,饲料中添加15％螺旋藻,尼罗罗非鱼幼鱼的增重率和特定生长率最...  相似文献   

11.
Abstract

Tissue residues were measured in striped bass Morone saxatilis that had been injected intraperitoneally with 50 mg oxytetracycline (OTC)/kg or had been fed a ration containing 75 mg OTC/kg of fish daily for 10 d. Concentration of OTC in muscle of fish fed medicated feed was below the quantitation limit in 67% of the fish 12 d after treatment and was below the quantitation limit in all fish after 16 d at 23°C. The calculated terminal elimination rate constant (β) was 0.20/d (range, 0.15–0.37/d), and the half-life was 2.7 d (range, 1.9–4.5 d). The concentration of OTC in muscle after intraperitoneal injection was below the quantitation limit after 24 d at 23°C. The β-value was 0.34/d and half-life was 2.0 d in fish injected with OTC intraperitoneally.  相似文献   

12.
本试验旨在研究胰岛素受体-1(IR-1)在尼罗罗非鱼不同组织中的表达及其对注射葡萄糖的响应。利用PCR扩增的方法从尼罗罗非鱼肌肉中克隆IR-1的c DNA片段,并通过半定量PCR检测,比较IR-1在肌肉、肝脏和心脏中的表达差异。选取体重约为100 g的尼罗罗非鱼160尾,随机分2组,每组4个重复,每个重复20尾。试验组腹腔注射葡萄糖(每100 g体重30 mg),对照组以相同剂量腹腔注射0.7%的无菌生理盐水。在注射前(0 h)和注射后的1、3、6和12 h分别进行采样,测定血浆葡萄糖和胰岛素含量,并通过实时荧光定量PCR检测IR-1在肌肉、心脏和肝脏中的mRNA相对表达量。结果显示:1)克隆出的IR-1 c DNA片段,其Gen Bank登陆号为JN967750,大小为1 979 bp,编码548个氨基酸。序列分析发现,尼罗罗非鱼的IR-1与其他物种比较具有很高的保守性,并具有丰富的酪氨酸激酶特征性序列。2)IR-1在尼罗罗非鱼肌肉、心脏和肝脏中均有较高的表达量,其中在肝脏和肌肉中的表达量基本一致,而在心脏中的表达量相对较低。3)试验组血浆葡萄糖含量在注射葡萄糖1 h后达到最高,并显著高于对照组(P0.05),而后开始下降,3 h后恢复到正常水平;试验组血浆胰岛素含量在葡萄糖注射3 h后达到最高,并显著高于对照组(P0.05),而后开始下降,12 h后恢复到正常水平。试验组肌肉和肝脏中IR-1 mRNA的相对表达量在注射葡萄糖后6 h时达到最高,显著高于对照组(P0.05),在12 h时恢复到正常水平;试验组心脏中IR-1 mRNA的相对表达量在注射葡萄糖后的12 h内没有发生显著变化(P0.05)。结果表明,注射葡萄糖后即刻升高了尼罗罗非鱼的血浆葡萄糖含量,相对于血浆葡萄糖含量的升高,血浆胰岛素含量的升高相对延迟,而肌肉和肝脏中IR-1 mRNA相对表达量的提高又延迟于血浆胰岛素含量的升高,从而加重了尼罗罗非鱼对葡萄糖的代谢负担。  相似文献   

13.
Cytochromes P450 comprise a superfamily of proteins that play a crucial role in the biotransformation of numerous chemicals. Purified CYPs can be used e.g. in studies on structure or determining the drug metabolism pathways. In this work, purification of the porcine CYP1A and CYP2A19 to electrophoretic homogeneity from the pig hepatic microsomes using octylamino Sepharose and hydroxylapatite column chromatography is reported. The proteins have been clearly recognized by commercial antibodies against rat and human CYP1A2 (porcine CYP1A) and human CYP2A6 (CYP2A19) respectively, using Western blot. Activities of both enzymes were determined by specific substrates, 7-ethoxyresorufin, 7-methoxyresorufin (CYP1A) and coumarin (CYP2A19). The isolated enzymes show kinetic parameters similar to human counterparts. Taken together, pig cytochromes can be used for the testing of veterinary drug metabolism, useful for the determination of drug residues in meat of pigs. The results obtained show that the pigs may be a suitable model for biotransformation of xenobiotics in humans.  相似文献   

14.
A time-resolved fluoroimmunoassay (TR-FIA) was established and validated that allows for the determination of plasma concentrations of insulin-like growth factor I (IGF-I) in three domestically cultured fishes: channel catfish (Ictalurus punctatus), hybrid striped bass (Morone chrysopsxM. saxatilis), and rainbow trout (Oncorhynchus mykiss). Sensitivity of the assay was 0.20 ng/ml. Intra- and inter-assay coefficients of variation (CV) were <7 and <12%, respectively. Serial dilutions of plasma from each species were parallel to the standard curve. Recovery of IGF-I from spiked plasma samples was >90% for all three species of fishes. The IGF-I TR-FIA was biologically validated via its use to determine the effect of fasting on circulating IGF-I levels in channel catfish. Fasting-induced changes in plasma growth hormone (GH), hepatic IGF-I mRNA expression, and pituitary GH mRNA expression were also determined. Fasted channel catfish lost 5.6 and 15.6% body mass after 2 and 4 weeks of fasting, respectively. Plasma IGF-I concentrations were depressed (P<0.05) relative to fed controls following 2 and 4 weeks of fasting. Plasma GH concentrations were not different (P>0.05) in fasted fish after 2 weeks, but significantly increased (P<0.05) by 4 weeks of fasting. Hepatic IGF-I mRNA expression after 2 and 4 weeks of fasting was reduced (P<0.05) relative to fed controls. Pituitary GH mRNA expression was similar (P>0.05) between 2-week-fasted catfish and fed controls, but was increased (P<0.05) in 4-week-fasted catfish. The IGF-I TR-FIA was sensitive, accurate, and precise for all three species of fishes, and provided a low-cost, and non-radioisotopic method for quantifying plasma IGF-I levels in fed and fasted channel catfish.  相似文献   

15.
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16.
Hybrid striped bass (Morone chrysops X Morone saxatilis ) are an important aquaculture species yet there are few diagnostic tools available to assess their health. Hematology and clinical chemistry analyses are not used extensively in fish medicine due to the lack of reference intervals for various fish species, and because factors such as age can affect blood values. There is little published information regarding age-related changes in blood values of juvenile fish. It is important to evaluate juvenile fish, as this is the time they are raised in aquaculture settings. Determining age-related changes in the blood values of fishes would further develop clinical pathology as a diagnostic tool, enhancing both fish medicine and the aquaculture industry. The results of standard hematology and clinical chemistry analysis were evaluated in juvenile hybrid striped bass at 4, 6, 9, 15, and 19 months of age. Values for PCV and RBC indices were significantly lower, and plasma protein concentration was significantly higher in younger fish. Total WBC and lymphocyte counts were significantly higher in fish at 6 and 9 months of age, while neutrophil and monocyte counts were higher at 6, 9, and 15 months. Eosinophil counts were significantly higher in 9-month-old fish. The majority of hematologic values fell within previously established reference intervals, indicating that only slight modification to the intervals is necessary for evaluating hematologic results of hybrid striped bass at different ages. The following analytes deviated sufficiently from adult reference intervals to warrant separate reference values: plasma protein concentration at 4 months, WBC and lymphocyte counts at 15 and 19 months, and thrombocyte-like-cells at 9 months of age. Values for most biochemical analytes were significantly different among age groups except for creatinine and potassium concentrations. Comparisons with reference intervals were not made for biochemical analytes, because established reference intervals were not available. Age-related changes in hematologic and biochemical values of striped bass were similar to those reported for rainbow trout and mammals.  相似文献   

17.
There is a need to develop simple, rapid, and accurate methods for assessing health in fish populations. In this study we demonstrate that use of fluorescein, a nontoxic fluorescent dye, can rapidly and easily detect the presence of skin ulcers in all fish tested, including rainbow trout (Oncorhynchus mykiss), channel catfish (Ictalurus punctatus), goldfish (Carassius auratus), and hybrid striped bass (Morone saxatilis male X M. chrysops female). Exposure of fish to as little as 0.10 mg fluorescein per milliliter of water for 3 minutes was sufficient to identify experimentally induced lesions, even pinpoint ulcerations. Such lesions were not visible to the naked eye but were clearly demarcated with fluorescein treatment. Examination of fish that appeared clinically normal often revealed the presence of focal ulcerations, which might have been a consequence of damage during capture, but it also might suggest that skin ulceration may be common even in "clinically normal" fish. Exposure of either nonulcerated or experimentally ulcerated hybrid striped bass to an excessively high concentration of fluorescein had no apparent effect on health or survival. Our studies suggest that fluorescein may be a highly useful tool for rapid health screening in fish populations.  相似文献   

18.
Borneol is a traditional Chinese medicine. In Chinese veterinary clinics, borneol and its related compounds are often used in combination with florfenicol to treat respiratory infections. This study investigated whether the pharmacokinetics of florfenicol in rats was affected by its concomitant use with borneol. Sprague-Dawley rats were intragastrically administered borneol (50 mg/kg body weight (BW)) or 0.5% carboxymethyl-cellulose sodium for 7 consecutive days, and then intragastrically administered florfenicol (25 mg/kg BW) on the eighth day. Pharmacokinetic studies showed that borneol significantly decreased the area under the concentration-time curve from zero to infinity (AUC(0-t)), time to reach peak concentration (Tmax), and the peak concentration (Cmax) values of florfenicol, whereas the values of mean residence time from zero to infinity (MRT(0-t)), elimination half-life (t1/2z), apparent volume of distribution fraction of the dose absorbed (Vz), and plasma clearance fraction of the dose absorbed (CLz) were increased significantly. Furthermore, the mRNA expression levels of multidrug resistance 1 (MDR1) and cytochrome P450 3A1 (CYP3A1) in the jejunum and of CYP1A2 and CYP2C11 in the liver were significantly upregulated by borneol. In conclusion, borneol decreased absorption, increased clearance, improved distribution, and increased the mean residence time of florfenicol in rats, possibly through regulating the mRNA expression levels of drug-metabolizing enzymes and efflux transporters.  相似文献   

19.
1. A study was conducted to determine the cytochrome P450 enzymes responsible for the bioactivation of aflatoxin B1 into its epoxide form (AFBO) in turkey liver microsomes. 2. The strategies used included the measurement of prototype substrate activity for specific human P450s, use of selective inhibitors, determination of correlation between aflatoxin bioactivation and enzymatic activity of prototype substrates and the determination of immunoreactive proteins using antibodies against human P450s. 3. Enzymatic activity and immunoreactive proteins corresponding to the turkey orthologs CYP1A1, CYP1A2, CYP2A6 and CYP3A4 were detected, but not for the CYP2D6 ortholog. 4. The results of the inhibition and correlation studies strongly suggest that the turkey CYP2A6 ortholog and, to a lesser extent, the CYP1A1 ortholog, are involved in the bioactivation of aflatoxin B1 in turkey liver microsomes. 5. This is the first study reporting the role of CYP2A6 in the bioactivation of AFB1 in an avian species and the role of CYP1A1 in any species.  相似文献   

20.
Corticosteroids have been reported to induce immunosuppression in fish exposed to many types of bacterial antigens. We document a similar phenomenon in fish exposed to infectious pancreatic necrosis virus (IPNV). Fingerling striped bass that were injected with the steroid triamcinolone acetonide (100 mg/kg body weight) 24 hours before receiving intraperitoneal inoculation with IPNV became viremic 3 days post inoculation (dpi) and virus was still detected in the buffy coat cells 14 dpi. In contrast, viremia could not be detected after 7 dpi in fish that received virus but not steroids. Circulating virus neutralizing antibodies were first detected in steroid treated fish at 10 dpi compared to 7 dpi for the virus injected fish and titers were consistently lower in the steroid group. Steroid treatment of chronic IPNV-carriers did not induce detectable viremia nor alter circulating antibody levels in chronic IPNV-carriers. None of the striped bass demonstrated clinical signs of viral disease.  相似文献   

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