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21.
Cultured blue shrimp (Penaeus stylirostris) were treated with normal therapeutic amounts of formalin (50 and 150 ppm) for 6 or 24 h. Analyses for extractable formaldehyde residues were run on the tails from these shrimp immediately after death and after storage at ambient (24°C) and refrigerated temperatures. No formaldehyde residues in these shrimp were found to result from the therapeutic use of formalin. However, shrimp tail muscle was found to produce small amounts (up to 4.8 ppm) of extractable formaldehyde during postmortem decomposition. 相似文献
22.
The lack of approved drugs and chemicals needed to manage disease and pests in culture systems is the major constraint facing the penaeid shrimp culture industry in the United States. The industry needs the timely approval of the therapeutants for disease control for cost effectiveness and public safety. The approval process for the needed chemotherapeutants (drugs, parasiticides, disinfectants, and water quality agents) is administered by the US. Food and Drug Administration (FDA) and the US. Environmental Protection Agency (EPA). Both FDA and EPA have procedures for registration of compounds for minor use whereby needed approvals may be obtained at far less cost than is typical for uses in major agricultural industries.
Aquatrine® is the only compound with specific approval for use in shrimp culture. Three others—formalin, oxytetracycline, and trifluralin—have entered the approval process. Because of human safety concerns, replacements are needed for malachite green, chloramphenicol, and the nitrofurans. Candidates for replacing these compounds include trifluralin, oxolinic acid, nalidixic acid, the potentiated sulfonamides, erythromycin, and oxytetracycline. A need exists for an environmentally safe and effective agent to treat fusarium disease.
The U.S. Department of Agriculture Interregional Research Project Number 4 (IR-4), in conjunction with FDA, has begun addressing the problems of the aquaculture industry. Thus, the penaeid shrimp industry has an excellent opportunity to obtain the approvals of chemotherapeutants that are needed for continued growth toward a full potential in this country. 相似文献
Aquatrine® is the only compound with specific approval for use in shrimp culture. Three others—formalin, oxytetracycline, and trifluralin—have entered the approval process. Because of human safety concerns, replacements are needed for malachite green, chloramphenicol, and the nitrofurans. Candidates for replacing these compounds include trifluralin, oxolinic acid, nalidixic acid, the potentiated sulfonamides, erythromycin, and oxytetracycline. A need exists for an environmentally safe and effective agent to treat fusarium disease.
The U.S. Department of Agriculture Interregional Research Project Number 4 (IR-4), in conjunction with FDA, has begun addressing the problems of the aquaculture industry. Thus, the penaeid shrimp industry has an excellent opportunity to obtain the approvals of chemotherapeutants that are needed for continued growth toward a full potential in this country. 相似文献
23.
We produced a panel of monoclonal antibodies (MAbs) from the fusion of Taura syndrome virus variants from Belize (TSV-BZ) immunized BALB/cJ mouse spleen cells and non-immunoglobulin secreting SP2/0 mouse myeloma cells. One antibody, 2C4, showed strong specificity and sensitivity for TSV in dot-blot immunoassay and immunohistochemistry (IHC) analysis. The MAb reacted against native TSV-BZ, TSV variants from Sinaloa, Mexico (TSV-SI) and TSV variants from Hawaii (TSV-HI) in dot-blot immunoassay. By IHC, the antibody identified the virus in a pattern similar to the digoxigenin-labelled TSV-cDNA probe for the TSV-BZ, TSV-HI and TSV-SI variants, but not for the TSV variants from Venezuela (TSV-VE) and the TSV variants from Thailand (TSV-TH). MAb 2C4 did not react against other shrimp pathogens or with normal shrimp tissue. Western blot analysis showed a strong reaction against CP2, a region of high antigenic variability amongst TSV variants. This antibody has potential diagnostic application in detection and differentiation of certain TSV biotypes. 相似文献
24.
Brenda L. White Paul J. Schofield Bonnie T. Poulos Donald V. Lightner 《Journal of the World Aquaculture Society》2002,33(3):341-348
Among the strategies being developed to improve survival and harvest yields in the farming of Pacific white shrimp Litopenneus vannumei is breeding domesticated family lines and the selection for further development of those lines that demonstrate resistance to Taura syndrome virus (TSV) challenge in the laboratory. A standardized laboratory challenge method for measuring TSV resistance by per os exposure to the virus, relative to a reference stock of L. vannamei , was developed and used to screen a total of 176 family lines provided by five different companies over a period of several months. All challenged shrimp were exposed to TSV per os by feeding minced TSV-positive shrimp carcasses at ∼10% of the shrimp biomass once per day for three consecutive days. Studies were carried out for a minimum of 14 d from the first day (day 0) of exposure to TSV. The survival rates obtained following TSV challenge of the selected L. vannamei families ranged from 0% to 100%, with a mean of 31%. The reference line of L. vannamei ("Kona line") gave survival rates of 0% to 37% with a mean of 13%. The results of the present study demonstrate that the use of a relatively simple laboratory challenge procedure provides a mechanism to evaluate and compare resistance to TSV among selected L. vannamei families and to predict the performance of selected stocks in farm environments where TSV is enzootic. 相似文献
25.
L Lightner B M Christensen G W Beran 《Journal of the American Veterinary Medical Association》1978,172(5):564-567
A wealth of data was available on intestinal nematode infections of dogs and cats in the Ames, Iowa, practice area served by the Iowa State University Veterinary Clinic. From July 1966 through June 1974, 8.5% of 33,594 dogs and 4.5% of 11,995 cats hospitalized for 1 or more days were recorded as infected with at least 1 type of intestinal nematode. For both dogs and cats, infection rates were generally higher in males than in females and in those that were sexually intact, compared with those that were neutered. The highest prevalence of hookworm infections in both dogs and cats was recorded in June and July, and the highest prevalence of ascarid infections in cats, but not in dogs, was in December. Seasonal patterns were not demonstrated for other nematode infections. Ascarid infections in dogs and cats and hookworms infections in dogs were most prevalent in 2-week-old to 2-month-old animals. Whipworm infections in dogs and hookworm infections in cats generally appeared at greater ages, reaching their highest prevalence in hosts 1 to 2 years old. 相似文献
26.
Visceral leishmaniasis in the German shepherd dog. I. Infection, clinical disease, and clinical pathology 总被引：2，自引：0，他引：2
Two groups of three German shepherd dogs each were inoculated with Leishmania chagasi or Leishmania donovani amastigotes and the infection was followed for 82 days. The dogs developed a persistent infection, became thin, and developed splenomegaly and lymphadenomegaly by 55 days after inoculation. All dogs developed a normocytic, normochromic anemia of increasing severity. Thrombocytopenia and leukopenia occasionally occurred. Blood tryptophan levels were decreased significantly in infected dogs. Increased total serum protein, with hypergammaglobulinemia and hypoalbuminemia, was present in all dogs to various degrees. There was a marked increase in gamma globulins, with smaller increases in alpha and beta globulins. Many of the clinicopathologic changes observed in these dogs were similar to the disease as it occurs in man. The German shepherd dog may be a useful laboratory model for the study of visceral leishmaniasis. 相似文献
27.
Carlos R. Pantoja Xiaoling Song Lee Xia Hui Gong Josh Wilkenfeld Brenda Noble Donald V. Lightner 《Aquaculture (Amsterdam, Netherlands)》2005,250(3-4):573-578
A total of 36 gravid female shrimp Fenneropenaeus chinensis, captured off the coast of Qingdao, Peoples Republic of China, from April 20 through April 24, 2001, were examined by PCR for the presence of WSSV and HPV, the two most prevalent viral diseases affecting this species of shrimp in this region of China. Eight spawns, derived from 8 different females, were selected from shrimp where no WSSV or HPV had been detected. Nauplii obtained from 7 individual spawns and unhatched eggs from one other shrimp were transported to the University of Arizona, in Tucson, Arizona, USA, for larval rearing and production of postlarvae under quarantine protocols. The resultant postlarvae were kept in Primary Quarantine for approximately 2 months, while additional tests were performed to determine their specific pathogen-free (SPF) status according to criteria set by the United States Marine Shrimp Farming Program (USMSFP). By the time the shrimp had reached an average weight of approximately 0.4 g, no USMSFP specific listed pathogens had been detected in any of the 7 hatches and the shrimp were released into Secondary Quarantine at the Oceanic Institute in Kailua-Kona, Hawaii for production of a F1 generation. This F1 generation may be used as a SPF founder population for propagation and selection programs. 相似文献
28.
Quantitative real time PCR for the measurement of white spot syndrome virus in shrimp 总被引：4，自引：0，他引：4
Quantitative real time PCR, recently developed in molecular biology, is applied in this paper to quantify the white spot syndrome virus (WSSV) in infected shrimp tissue. The WSSV content in moribund shrimp of all species tested ( Penaeus stylirostris, P. monodon, P. vannamei ) ranged from 2.0 × 104 to 9.0 × 1010 WSSV copies μg–1 of total DNA ( n =26). In whole moribund post-larvae, 4.3 × 109 WSSV copies μg–1 of DNA were detected which is equivalent to 5.7 × 1010 WSSV copies g–1 of post-larvae. The comparison of WSSV content between different tissues showed that muscle and hepatopancreas tissues contained 10 times less virus than gills, pleopods and haemolymph. With inocula of known virus content, bioassays by immersion challenge showed that a minimum of five logs of WSSV copies was necessary to establish disease in the challenged shrimp. In contrast, five logs of WSSV copies injected into shrimp muscle produced a LT-50 of 52 h. This real time polymerase chain reaction (PCR) technique is sensitive (four copies), specific (negative with DNA from shrimp baculoviruses and parvoviruses), dynamic (seven logs) and easy to perform (96 tests in <4 h). 相似文献
29.
Qiong Wang Brenda L. White Rita M. Redman Donald V. Lightner 《Aquaculture (Amsterdam, Netherlands)》1999,170(3-4):179-194
White spot syndrome virus (WSSV) is one of the most important pathogens of penaeid shrimp. It is widely distributed in most Asian countries where penaeid shrimp are cultured, as well as in the Gulf of Mexico and SE USA. The virulence of six geographic isolates of WSSV was compared using Litopenaeus vannamei postlarvae and Farfantepenaeus duorarum juveniles. The six geographic isolates of WSSV originated from China, India, Thailand, Texas, South Carolina, as well as from crayfish maintained at the USA National Zoo. For challenge studies, virus infected tissues were given per os to L. vannamei postlarvae and Fa. duorarum juveniles. Resultant WSSV infections were confirmed by histological examination. The cumulative mortality of L. vannamei postlarvae reached 100% after challenge with each of the six geographic isolates of WSSV. However, the Texas isolate caused mortalities more rapidly than did the other shrimp isolates; the crayfish WSSV isolate was the slowest. In marked contrast, cumulative mortalities of juvenile Fa. duorarum reached only 35–60%, and varied among the geographic isolates of WSSV. Interestingly, in Fa. duorarum, the Texas WSSV isolate was also the most virulent, while the crayfish WSSV was the least virulent. The findings suggest that slight differences in virulence exist among geographic isolates of WSSV, and that susceptibility may vary with species and lifestages of the host. 相似文献