• Title/Summary/Keyword: Experimental Infection

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THE EFFECT OF DUCK HEPATITIS B VIRUS ON PERSISTENT INFECTION ON LAYING PERFORMANCE IN BROWN TSAIYA DUCKS

  • Tai, C.;Tai, J.J.L.;Chen, P.J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.6 no.3
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    • pp.331-337
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    • 1993
  • In order to understand the effect of duck hepatitis B virus (DHBV) on the economic performance of ducks, Three groups (DHBV congenitally infected, experimentally infected and DHBV negative) Brown Tsaiya ducks (Anas platyrhyncha) were used for experimental animals. Artificial insemination and pedigree hatching were applied in the propagation of ducklings, and the efficiency of vertical transmission and experimental infection was analyzed through the detection of DHBV DNA in the sera of 8-week-old offspring. The observation of the records of the first year indicated that the persistent infection had no significant effects on the performance of ducks, except the egg number of survival ducks up to 40 week of age. Thus DHBV infection did not appear to give ill effects to the economic performance of ducks in first laying year. A higher infection rate (85.3%) was obtained in congenital transmission than that (75.5%) of experimental infection. Both modes of infection did not reach 100% infectious rate, although some ducks developed transient viraemia in a tracing of DHBV DNA for 24 weeks to 11 challenged ducklings.

Experimental Inection with Saproloenia diclina Type I in Eels(Anguilla japonica) (뱀장어 수생진균(水生眞菌), Saprolegnia didina Type I의 실험적(實驗的) 감염(感染))

  • Min, Hong-Kyu;Park, Nam-Yong;Hatai, Kishio
    • Journal of fish pathology
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    • v.3 no.2
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    • pp.61-66
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    • 1990
  • Experimental infection and histopathological study using a deleterious aquatic fungus (Saprolegnia diclina type I) were carried out in the eels (Anguilla japonica) to know what pathological changes the fungus would produce in the affected eels. The eels in group A and B which were treated with fish net were not susceptible to experimental infection. In group C which the cuticle was scraped by artificial treatment, the aquatic fungi were invading all the eel bodies including the desquamated lesions. Histopathologically, the affected eels were markedly reduced in number of goblet cells and showed moderate damage of the clavate cells. Nodular formation involving ecchymotic hemorrhage was seen in some affected areas. The eels survived to 25 days after experimental infection.

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Experimental Infection of Rainbow Trout (Oncorhynchus mykiss) with Viral Hemorrhagic Septicemia Virus (VHSV, Genotype IVa) from Olive Flounder (Paralichtys olivaceus) (넙치 (Paralichtys olivaceus) 유래 viral hemorrhagic septicemia virus (VHSV, genotype IVa)의 무지개송어 (Oncorhynchus mykiss) 감염 실험)

  • Kim, Wi-Sik;Jeong, Ha-Na;Kong, Kyoung-hui;Kim, Ah-ra;Jeon, Young-Ho;Oh, Myung-Joo
    • Korean Journal of Ichthyology
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    • v.28 no.3
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    • pp.141-146
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    • 2016
  • Experimental infection of rainbow trout Oncorhynchus mykiss with viral hemorrhagic septicemia virus (VHSV, genotype IVa) from olive flounder Paralichtys olivaceus was examined. The cumulative mortalities of three different lot of rainbow trout fry challenged with VHSV ($10^{6.3-7.3}TCID_{50}$/fish) were less than 15%. No difference of virulence was observed in experimental infection using 5 in vivo passaged VHSV and original VHSV. No mortality was observed in seawater-reared rainbow trout (adult) challenged with VHSV ($10^{5.3-6.3}TCID_{50}$/fish) and virus was not detected in the fish. We thus concluded that VHSV from olive flounder has low virulence to rainbow trout fry, but not pathogenic to seawater-rainbow trout (adult).

Experimental infection or Argulus juponicus in freshwater fishes (담수어류에서 Argulus japonicus의 실험감염에 관한 연구)

  • 한규삼;정영미;박태욱;임채웅;송희종;도홍기
    • Korean Journal of Veterinary Service
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    • v.21 no.4
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    • pp.431-437
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    • 1998
  • Argulus spp, a small group of parasitic curstaceans called Branchiura, is particularly important in freshwater acquaculture. We investigated the infection of Argulus to several different species of fishes and therapy effect of masoten. Argulus japonicus was collected from Okjeong lake, Chonbuk province and experlmen-tally infected to freshwater fishes from July to August 1998. The results were as follows ; 1. The shape of a Agulus is an oval and dorsoventrally flattened, with first maxillae and second maxillae, and four pairs of legs. 2. The size of the adult stage of A japonicus was 3.2-5.0$\times$2.3-2.9mm in female and 1.5-3.1$\times$1.6-2.9mm in male. 3. In the trial of experimental infection with A japonicus to non-scaled fishes, Parasilurus asotus and Ictalurus punctalus, were infected and some of them died after severe infection. However, A japonica was not infected at all. 4. Masoten treatment for A japonicus was effective at 0.2 ppm once a day for 3 days and parasites on the surface of fishes disappeared after five days.

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Comparative in vitro and in vivo Antibacterial Activities of Cefatrizine/clavulanic Acid Combination and Other $\beta$-lactam Antibiotics (Cefatrizine과 clavulanic acid 병합제의 in vitro 및 in vivo 항균력)

  • 최성학;김지영;김계원;김원배;심미자
    • Biomolecules & Therapeutics
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    • v.7 no.1
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    • pp.44-53
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    • 1999
  • The resistant strains due to the extended-spectrum $\beta$-lactamase (ESBL) were susceptible to cefatrizine combined with clavulanic acid. The purpose of this study was to evaluate the in vitro and in vivo antibacterial activities of cefatrizine/clavulanic acid (CTRZ/CV) combination at a ratio of 2 : 1 in comparison with cefaclor (CCLO), cefuroxime (CRXM), cefuroxime axetil (CRXMA) and amoxicillin/clavulanic acid (AMXCCV). CTRZ/CV showed good activity against laboratory strains of gram-positive and gram-negative bacteria and exhibited excellent antibacterial activity against $\beta$-lactamase-producing strains. The bactericidal activity of CTRZ/CV was superior to that of CCLO and CRXM, and almost equal to that of AMXCCV against the $\beta$-lactamase-producing strains. The in vitro results were substantiated. by in vivo mouse experimental infection studies with $\beta$-lactamase-producing and non-producing strains. In mixed experimental infection due to $\beta$-lactamase-producing and non-producing strains, the therapeutic efficacy of CTRZ/CV was superior to that of CTRZ, CCLO, CRXMA and AMXCCV. In respiratory tract infection in mice due to Klebsiella pneumoniae EB4O, CTRZ/CV was more erective than CCLO, CRXMA and AMXCCV and also more efficacious than CCLO, CRXMA and AMXCCV in urinary tract infection in mice due to Escherichia coli EB13. These results indicate that CTRZ/CV is a useful drug for the treatment of infection caused by $\beta$-1actamase-producing strains including ESBL-producing strains.

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Experimental Infection for the Neutralization of White Spot Syndrome Virus (WSSV) in Wild Captured Sand Shrimp, Crangon affinis (자연산 자주새우(Crangon affinis)에서 흰반점바이러스(WSSV)의 neutralization을 위한 인위감염(experimental infection))

  • Gong, Soo-Jung;Kim, Yeong-Jin;Choi, Mi-Ran;Kim, Sung-Koo
    • Journal of Life Science
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    • v.20 no.9
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    • pp.1294-1298
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    • 2010
  • White spot syndrome virus (WSSV) is one of the most virulent viral agents threatening the penaeid shrimp culture industry. This study was carried out to evaluate the susceptibility of the sand shrimp, Crangon affinis, to WSSV as an alternative experimental model. WSSV caused 100% mortality in C. affinis within 7 days after experimental infection by immersion. Based on challenge studies, it was confirmed that C. affinis could be a potential host in WSSV transmission. Also, the neutralization of WSSV was carried out using an antiserum raised against recombinant envelop protein rVP466 to evaluate the WSSV infection mechanism. A constant amount of WSSV (at $1{\times}10^4$ diluted stocks) was incubated with various amounts of antiserum and then mixed to 20 l reservoir for the immersion challenge of C. affinis for neutralization. At 5 days post challenge, the shrimp in the positive control immersed in the immersion reservoir containing WSSV stock showed 100% mortality. The shrimps challenged with the 3 different mixtures of WSSV and rVP466 antiserum (1:0.1, 1:0.5 and 1:1) showed 100%, 68.8% and 68.8% mortality at 14 days post challenge, respectively. These results indicated that the antiserum raised against rVP466 could block WSSV infection in C. affinis. Therefore, this study confirmed that C. affinis can be naturally infected by WSSV as another potential host and that C. affinis can be used as an alternative experimental animal instead of penaeid shrimps.

Esperimental Infection of Infectious Bovine Rhinotracheitis Virus to Rabbits Immunosuppressed with Dexamethasone (Dexamethasone으로 면역기능(免疫機能) 저하(低下)된 토끼에 Infectious Bovine Rhinotracheitis Virus 감염시험(感染試驗))

  • Min, Won-gi;Jun, Moo-hyung;Park, Seong-kuk;An, Soo-hwan;Cha, Yeon-ho
    • Korean Journal of Veterinary Research
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    • v.28 no.1
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    • pp.105-110
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    • 1988
  • To establish a laboratory animal model for study on development of diagnostic methods for infectious bovine rhinotracheitis virus(IBRV), experimental infection of the virus to rabbits immunosuppressed with dexamethasone(DX) were carried out. Results obtained throughout the experiments were as follows. When lymphocyte activity was measured by lymphocyte transformation to phytohaemagglutinin in parallel with total and differential leucocyte counting, both groups treated with 2.0mg DX once and 1.0mg DX daily showed marked immunosuppression between 5 to 72 hrs. after administration. The degree of suppression of lymphocyte activities was more remarkable in the latter group. IBRV PQ7 strain at $10^{7.5}\;TCID_{50}/0.2ml$ was inoculated into conjunctival sacs of rabbits immunosuppressed with DX and non-treated. During 3 weeks observation, the immunosuppressed groups revealed mild conjunctivitis, viremia and virus recovery by 33.3 to 100%, whereas the DX nontreated group showed viremia and virus recovery with no clinical conjunctivitis by one of three rabbits(33.3%). In conclusion, it was indicated that experimental infection of IBRV PQ7 strain to rabbit was limited in prerequisite to immunologic modification by administration of immunosuppressive drugs.

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Comparison of diseases resistance between white and brown layer lines to experimental infection of Salmonella gallinarum (가금티푸스군의 인공감염에 대한 백색 및 갈색 산란계 계통간의 내병성 비교)

  • Woo, Yong-ku;Kim, Bong-hwan
    • Korean Journal of Veterinary Research
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    • v.38 no.4
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    • pp.784-792
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    • 1998
  • This study was conducted to select resistant chicken-line between Brown and White layer lines against Salmonella gallinarum infection. The Brown and White layer chickens allocated into different age groups were inoculated with S gallinarum (WJO-126) either orally($1{\times}10^7cfu$) or intramusculaly($5{\times}10^6cfu$) and clinical observations were made for 2 weeks. All dead birds were necropsied and culture was made to recover the inoculated organinsm from liver, spleen, brain, bone marrow and cecal contents. Serum was isolated from all live birds after 2 weeks experiment and these birds were also necropsied and cultured to reisolate S gallinarum. The brown layers showed very high mortality to S gallinarum infection regardless of their ages and routes of inoculation, while white layers did not shown any mortality by the direct effects of S gallinarum. The mortality rate of 2 week old brown layers, in particular, were 82.6% (19/23) in peroral group and 86.9% in intramuscularly inoculated group, while those of white layer groups were only 0.0% in both groups. S gallinarum could be reisolated from all dead birds, especially, from liver and spleen. This result was inferred that the organism is highly invasive on the chicken. The intramuscularly challenged birds showed more seropositive-reactors(86.9%) than orally inoculated groups(61.9%). The overall results of present study suggested that white layers are much more resistant than brown layers against the experimental infection of S gallinarum and shown experimentally that resistance to S gallinarum is a characteristic of the White-line layers.

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