• Title/Summary/Keyword: Infectivity

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Experimental infection of Paragonimus westermani in mice and rats

  • Fan, Ping-Chin;Lu, Huan;Lin, Ling-Hui
    • Parasites, Hosts and Diseases
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    • v.31 no.2
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    • pp.91-98
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    • 1993
  • To determine the infectivlty and maturity of nletacercanae of Parqgonimur westermani after keeping at low temperature for a long period, 45 mice and 45 rats were each infected with 20 metacercariae which were kept at $4^{\circ}C$ for 8 to 234 days. The worm recovery in mice increased with age of worm and reached a peak of 32% at 41-50 days and then decreased with age. The rate In rats first decreased to a lowest point of 6% at 71-100 days and then Increased with age. In 42 infected mice and 41 infected rats, 187 immature worms (183 tiny and 4 Juvenile ones) and 190 worms (164 tiny, 19 Juvenile and 7 mature ones) were recovered respectively. Two wormcysts with eggs only and 8 empty wormcysts were also found In the rats. In addition, the frozen metacercanae can still develop to mature worms in SD rats.

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Isolation and Physiological Characterization of a Novel Algicidal Virus Infecting the Marine Diatom Skeletonema costatum

  • Kim, JinJoo;Kim, Chang-Hoon;Youn, Seok-Hyun;Choi, Tae-Jin
    • The Plant Pathology Journal
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    • v.31 no.2
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    • pp.186-191
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    • 2015
  • Diatoms are a major component of the biological community, serving as the principal primary producers in the food web and sustaining oxygen levels in aquatic environments. Among marine planktonic diatoms, the cosmopolitan Skeletonema costatum is one of the most abundant and widespread species in the world's oceans. Here, we report the basic characteristics of a new diatom-infecting S. costatum virus (ScosV) isolated from Jaran Bay, Korea, in June 2008. ScosV is a polyhedral virus (45-50 nm in diameter) that propagates in the cytoplasm of host cells and causes lysis of S. costatum cultures. The infectivity of ScosV was determined to be strain- rather than species-specific, similar to other algal viruses. The burst size and latent period were roughly estimated at 90-250 infectious units/cell and <48 h, respectively.

Characterization of the White Spot Syndrome Baculovirus (WSBV) Infection In Fresh Shrimp, Penaeus chinensis, Cultured in Korea (한국의 양식대하에서의 흰반점증상 바이러스감염의 특징)

  • Heo Moon-Soo
    • Journal of Life Science
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    • v.15 no.2 s.69
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    • pp.248-252
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    • 2005
  • The virions of causative virus for white spot syndrome in cultured Fresh shrimp, Penaeus chinensis were rod-shaped, double envelope. An average size of the virion was 70 nm in diameter and $250\~300$ nm in length. Histopathological test of affected stomach, heart, and lymphoid organ revealed nuclear hypertrophy. Infectivity trials carried out by injection and feeding with purified virus revealed high cumulative mortality to healthy shrimp. The twenty one different protein species were detected in the analysis of virion. The length of total DNA from the purified virus particles were detected as a single band, double-stranded DNA molecule of approximately 114 kb.

Purification of Odontoglossum Ringspot Virus by DEAE-Cellulose Chromatography (DEAE 셀루로오즈 컬럼 크로마토그래피 기법에 의한 Odontoglossum 윤문 바이러스의 정제)

  • 이철호;박종오;정효원;나용준
    • Korean Journal Plant Pathology
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    • v.14 no.6
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    • pp.559-562
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    • 1998
  • Odontoglossum ringspot virus (ORSV) was finally purified from ORSV-infected orchid plants by diethylaminoethyl (DEAE) cellulose anion exchange column chromatography. The virus was reliably eluted by potassium chloride at the concentration from 0.1 M to 0.13 M. Partial purification was done by solubilization with Triton X-100 (allkylphenoxypolyethoxy ethanol) and precipitation with polyethylene glycol (PEG; MW 8,000). The finally purified ORSV represented one distinct homogeneous band and the molecular weight of its capsid protein was about 17,500 Dalton in electrophoretic analysis. Electron microscopy showed not only intact particles ranged from 280 nm to 340 nm in length, but also segmented particles that final 140 nm to 220 nm and even disks. Enzyme-linked immunosorbent assay (ELISA) showed that final yield was 12 mg/100 g of the infected leaves. Bioassay demonstrated that the purified ORSV had the normal infectivity to orchid plants and Nicotiana glutionsa. Based on these data, anion exchange column chromatography could be efficiently applied to the purification of ORSV and other viruses similar to ORSV.

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Generation of Baculovirus Expression Vector Using Detective Autographa California Nuclear Polyhedrosis Virus Genome Maintained in Escherichia coli for $Occ^{+}$ Virus Production

  • Je, Yeon-Ho;Chang, Jin-Hee;Roh, Jong-Yul;Jin, Byung-Rae
    • International Journal of Industrial Entomology and Biomaterials
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    • v.2 no.2
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    • pp.155-160
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    • 2001
  • We have generated a novel baculovirus genome which can be maintained in Escherichia coli that facilitates the rapid and efficient generation of recombinant baculovirus expression vectors. To make $Occ^{+}$ recombinant expression vectors, polyhedrin gene under the control of p10 promoter was inserted to bAcGOZA and this genome was designated bApGOZA. As in bAcGOZA, bApGOZA lacks a portion of the essential ORF1629 gene, but includes a mini-F replicon and selectable kanamycin-resistance marker, This occasion-producing activity of bApGOZA can be used very conveniently for its oral infectivity to insect larvae in mass production of foreign protein and insecticides.

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Pathogenic effects of porcine reproductive and respiratory syndrome virus isolates in swine tracheal ring culture

  • Park, Bong-kyun;Collins, James E.;Goyal, Sagar M.;Pijoan, Carlos;Joo, Han-soo
    • Korean Journal of Veterinary Research
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    • v.39 no.2
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    • pp.311-317
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    • 1999
  • Pathogenic effects of 29 different porcine reproductive and respiratory syndrome(PRRS) virus isolates were investigated in swine tracheal ring(STR) cultures by examining their effects on the ciliary activity of STR. Inhibition of ciliary movement and destruction of the tracheal epithelium were seen between 72 and 96 hours postinoculation(PI). Virus replication was demonstrated by examining viral infectivity of the supernatants from the STR cultures. PRRS virus antigen in macrophages was detected by a streptavidin-biotin complex(ABC) immunoperoxidase method. Of the 29 PRRS virus isolates, 8 isolates were classified into pathogenic, and the remaining 21 isolates were determined as mildly pathogenic or apathogenic viruses. These results suggest that STR examination may be used as a method for predicting pathogenic variability of PRRS virus isolates.

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cis-Diamminedichloroplatinum (II) (CDDP) Inhibits Bluetongue Virus (BTV) Core Associated Transcriptase Activity (CDDP를 처리한 Bluetongue Virus Core의 전사저해)

  • ;Manning, JaRue S.
    • Korean Journal of Microbiology
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    • v.29 no.1
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    • pp.34-39
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    • 1991
  • The BTV core associated transcriptase activity, assayed by acid precipitable counts, was reduced to an undetectable level after treat the core with .$100{\mu}{\M}$ CDDP. When the RNA transcripts prepared from the CDDP treated BTV core were analysed on agaroseurea gel, it was observed that the band intensity of the large size RNA was reduced while the band intensity of the small size RNA was enhanced. Northern blot analysis showed that much of the small size RNAs appeared to be prematurely terminated transcripts. These results suggest that CDDP adduction to the template RNA blocks chain elongation process of the virion bound transcriptase that is ultimately responsible for the inactivation of BTV infectivity.

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Isolation of Symbiotic Frankia EuIK1 Strain from Root Nodule of Elaeagnus umbellata (보리수나무 뿌리혹으로부터 Frankia EuIK1 공생균주의 분리)

  • 김성천
    • Journal of Plant Biology
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    • v.36 no.2
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    • pp.177-182
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    • 1993
  • The root nodules of Elaeagnus umbellata were coralloid-shape due to repeated dichotomous branching of nodule meristem. The filamentous endophyte with vesicle cluster ranging from 30 ${\mu}{\textrm}{m}$ to 60 ${\mu}{\textrm}{m}$ in diameter was present only in the cortical cells. The isolated endophytes in vitro culture showed typical Frankia morphology, consisting of highly branched hyphae ranging from 0.8 ${\mu}{\textrm}{m}$ to 1.0 ${\mu}{\textrm}{m}$ in diameter, terminal and intrahyphal sporangia varing in shape and size up to 60 ${\mu}{\textrm}{m}$ in length and laminated vesicles. Its infectivity and effectivity were confirmed by induction of nitrogen-fixing root nodules on the inoculated seedlings of two Elaeagnus species. Consequently, the isolate was confirmed as a true symbiont of Elaeagnus umbellata root nodule and named Frankia EuIK1.

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Differentiation and Detection of Phytoplasma using PCR from Diseased Plant in Korea

  • Lee, Kui-Jae
    • Plant Resources
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    • v.3 no.3
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    • pp.173-178
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    • 2000
  • This test checked jujube witches'-broom disease, sumac witches'-broom disease, paulonia witches'- broom disease, and mulberry dwarf disease whether or not they were infected by phytoplasma, using universal and specific primers. Upon treatment of DNA amplified by PCR of phytoplasma with Alu I , Hpa II and Sat I restricted enzymes, distinction of phytoplasmas was possible. Particularly, phytoplasma of each host was distinguishable by treatment of Hpa II restricted enzyme. Meanwhile, analysis of restricted enzymes of jujube witches'-broom disease showed a higher infectivity of phytoplasmas of two origins. There were a lot of relations between jujube witches'-broom disease and sumac witches'-broom disease, and between paulonia witches'-broom disease and mulberry dwarf disease.

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Isolation of Symbiotic Rhizobium spp. Strain from Root Nodule of Canavalia lineata (해녀콩(canavalia lineata) 뿌리혹으로부터 공생균주 Rhizobium spp.의 분리)

  • 김성천;안정선
    • Korean Journal of Microbiology
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    • v.27 no.4
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    • pp.398-403
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    • 1989
  • The root nodule of Canavalia lineta was classified as a determinate nodule and the symbiont as a Rhizobium-bacteriod based on their morphological characteristics. Isolated encosymbiont was similar both to R. leguminosarum and R. meliloti in its peritrichous arrangement of flagella and some of the physiological characteristics. Compared to control plants, Canavalia seedlings inoculated with the isolate grew normally due to induced root nodules, confirming isolate's infectivity and effectivity. Characteristics of the reisolated endosymbiont from induced root nodule were identical to those of the first isolate, indicating the nodules were induced by the first isolate. From these results, it was confirmed that Rhizobium strain isolated from the root nodules of Canavalia lineata was a real symbiont, and was named Rhizobium sp. SNU003.

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