• Korean Journal of Microbiology
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• v.22 no.2
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• pp.85-90
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• 1984

Two viruses were isolated from kidney and spleen tissues of goldfish(Carasius auratus) and the ovarian fluid of chum salmon(Oncorhynchus keta). Both viruses replicated and produced cytopathic effect in EPC, CHSE-214, and CHH-1 cell lines at $15^{\circ}C$. The isolates were resistant to pH 3 and choloroform. Antiserum to infections pancreatic necrosis virus(IPNV) serotype VR 299 neutralized the infectivity of both of the isolates. Electron microscopy showed that the particles had typical IPNV particle morphology with average diameters of 55nm, This paper describes the first isolation of viruses infecting cultured fish in Korea.

• Korean Journal of Microbiology
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• v.54 no.3
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• pp.222-227
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• 2018

Mycobacterium tuberculosis (MTB)-originated lipid antigen is presented on the antigen-presenting cell surface with CD1b. When monocyte-derived dendritic cells phagocytosed MTB H37Rv (Multiplicity of infection 10, infectivity: 46.89%), the CD1b expression level decreased slowly. Since this was just a live MTB-mediated phenomenon, it was not detected from heat-killed MTB or mycolic acid, which is a unique antigen of MTB. We confirmed that the phosphorylation of CD1b molecules using 2D electrophoresis with staining could phosphorylate and induce the presentation of the lipid antigen using the phagocytosis assay.

• Journal of Microbiology and Biotechnology
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• v.30 no.12
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• pp.1793-1800
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• 2020

Bifidobacterium strains can provide several health benefits, such as antimicrobial and immunomodulatory effects. Some strains inhibit growth or cell adhesion of pathogenic bacteria, including multidrug-resistant bacteria, and their antibacterial activity can be intensified when combined with certain antibiotics. In addition, some strains of bifidobacteria reduce viral infectivity, leading to less epithelial damage of intestinal tissue, lowering the virus shedding titer, and controlling the release of antiviral substances. Furthermore, bifidobacteria can modulate the immune system by increasing immunoglobulins, and inducing or reducing pro- or anti-inflammatory cytokines, respectively. In particular, these anti-inflammatory effects are helpful in the treatment of patients who are already suffering from infection or inflammatory diseases. This review summarizes the antimicrobial effects and mechanisms, and immunomodulatory effects of Bifidobacterium strains, suggesting the potential of bifidobacteria as an alternative or complementary treatment option.

• Korean Journal of Microbiology
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• v.46 no.1
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• pp.15-20
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• 2010

Xenotransplantation of pig organs is complicated by the existence of polytropic replication-competent porcine endogenous retroviruses (PERV) capable of infecting human cells. Two classes of infectious human-tropic replication-competent PERVs (PERV-A and PERV-B) and one class of ecotropic PERV-C are known. The potential for recombination between ecotropic PERV-C and human-tropic PERVs adds another level of infectious risk. A recombinant PERV-A/C (PERV-A14/220) virus is 500-fold more infectious than PERV-A. Two determinants of this high infectivity was identified; one was isoleucine-to-valine substitution at position 140 in RBD (receptor binding domain), and the other lies within the PRR (proline rich region) of the envelope protein. To examine whether the effects of the cytoplasmic tail of the PERV-C Env on fusogenesity also influences infectivity, we constructed a pseudotype retroviral vectors containing MoMLV core protein and PERV envelopes. Pseudotyping experiments with the PERV envelope glycoproteins indicated that recombinant PERV-A/C virus is 10-fold more infectious than PERV-A by lacZ staining. This result supports the suggestion that viral transduction of PERV-A/C is enhanced by a membrane-proximal cytoplasmic amphiphilic ${\alpha}$-helix in PERV-C Env tail.

• Korean Journal of Poultry Science
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• v.28 no.2
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• pp.83-89
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• 2001

Newcastle disease virus, CBP-1 strain isolated from Korean pheasants was passaged for 173 times by 9-day-old specific pathogenic free (SPF) embryonated eggs at $37^{\circ}C$ (parent strain) and subsequently passaged for 15 (cold attenuation (CA) -15) and 30(cold attenuation (CA) -30) times by 10-day-old of commercial broiler chicks embryonated eggs at $29^{\circ}C$, respectively, The Physical and chemical properties (sensitivity to lipid solvents, low pH and thermostability), pathogenicity (mean death time, intracerebral pathogenic index and intravenous patho-genic index), safety, booster or protective effect and characterization of temperature sensitivity were measured in cold attenuated CA-15 or 30 strain and compared to those of parent CBP-1 strain. NDV, CBP-1 CA-30 strain acquired cold attenuation and decreased infectivity at $41^{\circ}C$ compared to those of parent strain grown at $37^{\circ}C$. It lost hemagglutination activity (HA) and cell infectivity at $56^{\circ}C$ for 30, 60, and 120 Min. CA-30 strain treated with ethyl ether also lost its HA and cell infectivity. Both CA-30 and parent strains exhibited a little resistant to HA at pH 3.0 glycine HCI buffer. Intracerebral pathogenic index (ICPI) and intravenous pathogenic index (IVPI) of parent strain were 1.12 and 1.45, but decreased to 0.75 and 0.00 in CA-30 strain, respectively. The safety was evaluated by mortality in chicks inoculated with 10$^{4.0}$ EID$_{50}$ /0.1 ml. The mortalities of parent, CA-30 and commercial Bl strains were 17.5, 12.0 and 0.0%, respectively. The safety of CA-30 strain was higher than that of parent strain. The booster effects of CA-30 strain and parent strain performed in 4-week-old chicks after being vaccinated with primary commercial Bl strain.

• Journal of fish pathology
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• v.10 no.2
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• pp.165-176
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• 1997

Water samples collected from marine fish culture system in Korea were compared for their capability to reduce the infectivity titers of HRV (rhabdovirus olivaceus), FBV(flounder birnavirus) and RVS(retrovirus of salmonid). In addition, interaction between viruses and microorganisms present in the rearing seawater was examined. The titer of HRV and RVS were reduced at $15^{\circ}C$ to less than detectable limits within 3 to 5 days using untreated samples of seawater. No reduction of infectivity was noted in bacteria-free water treated by filtration or autoclaving. Bacteria (Pseudomonas and Vibrio sp.) isolated from the water collected from a flounder culture system showed the inactivation activity of HRV.

• Korean Journal of Veterinary Research
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• v.13 no.2
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• pp.147-160
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• 1973

The present experiments proposed to pass judgement upon the suitability as the second intermediate host of Clonorchis sinensis, of three kinds of fresh-water fish by having them infected with the cercaria of Clonorchis sinensis and then observing the penetrating ability of the cercaria, and maturity, the process of degeneration and extinction, and infectivity of the metacercaria of Clonorchis sinensis. The following is a brief summary of the leading facts gained through the experiments; 1. P. parva was easily subject to invasion of the cercaria, A. signifer was much less subject to the invasion, and finally A. asmussi was hard to invade. And the infectivity of the cercariae was in proportion to their penetrating ability mentioned in the above. 2. The examination of the cercariae after having three kinds of fresh-water fish infected with them disclosed that 24 hours after the infection, all of the cercariae formed their cysts in muscle and the metacercariae kept growing, and that 7 days later the metacercariae were found folding their bodies twice, and that in 15 days the characteristic structure of the metacercariae was complete and they made a vigorous rotary movement intermittently. 3. Then the metacercariae came to a state of maturity and beyond this stage some metacercariae in P. parva started the process of degeneration and extinction in 133 days; some in A. asmussi, in 140 days; and A. signifer, in 70 days. As more days elapsed, their degeneration and extinction increased in number, and in 269 days all of them in A. signifer became dead while those in A. asmussi were all dead in 460 days. However almost all of them in P. parva survived even after 770 days. The results shown above revealed that P. parva was the most suitable as the second intermediate host among three kinds of fresh-water fish and that A. signifer and A. asmussi were not quite recommendable as the second intermediate host. The ability of the cercaria to invade fresh-water fish, and life span of the metacercaria within fresh-water fish vary outstandingly according to species of fresh-water fish. An explanation as to the mechanism must wait as the subject to be further pursued.

• Microbiology and Biotechnology Letters
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• v.36 no.1
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• pp.12-20
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• 2008

Validation of viral safety is essential in ensuring the safety of mammalian cell culture-derived biopharmaceuticals, because numerous adventitious viruses have been contaminated during the manufacture of the products. Mammalian cells are highly susceptible to minute virus of mice(MVM), and there are several reports of MVM contamination during the manufacture of biopharmaceuticals. In order to establish the validation system for the MVM safety, a real-time PCR method was developed for quantitative detection of MVM in cell lines, raw materials, manufacturing processes, and final products as well as MVM clearance validation. Specific primers for amplification of MVM DNA was selected, and MVM DNA was quantified by use of SYBR Green I. The sensitivity of the assay was calculated to be $6{\times}10^{-2}TCID_{50}/mL$. The real-time PCR method was proven to be reproducible and very specific to MVM. The established real-time PCR assay was successfully applied to the validation of Chinese hamster ovary (CHO) cell artificially infected with MVM. MVM DNA could be Quantified in CHO cell as well as culture supernatant. When the real-time PCR assay was applied to the validation of virus removal during a virus filtration process, the result was similar to that of virus infectivity assay. Therefore, it was concluded that this rapid, specific, sensitive, and robust assay could replace infectivity assay for detection and clearance validation of MVM.

• Journal of Veterinary Clinics
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• v.28 no.1
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• pp.101-107
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• 2011

This study aimed to determine dose-response (DR) curve of avian influenza (AI) virus to predict the probability of illness or adverse health effects that may result from exposure to a pathogenic microorganism in a quantitative microbial risk assessment. To determine the parametric DR relationship of several strains of AI virus, 7 feeding trial data sets challenging humans (5 sets) and chickens (2 sets) for strains of H3N2 (4 sets), H5N1 (2 sets) and H1N1 (1 set) from the published literatures. Except for one data set (study with intra-tracheal inoculation for data set no. 6), all were obtained from the studies with intranasal inoculation. The data were analyzed using three types of DR model as the basis of heterogeneity in infectivity of AI strains in humans and chickens: exponential, beta-binomial and beta-Poisson. We fitted to the data using maximum likelihood estimation to get the parameter estimates of each model. The alpha and beta values of the beta-Poisson DR model ranged 0.06-0.19 and 1.7-48.8, respectively for H3N2 strain. Corresponding values for H5N1 ranged 0.464-0.563 and 97.3-99.4, respectively. For H1N1 the parameter values were 0.103 and 12.7, respectively. Using the exponential model, r (infectivity parameter) ranged from $1.6{\times}10^{-8}$ to $1.2{\times}10^{-5}$ for H3N2 and from $7.5{\times}10^{-3}$ to $4.0{\times}10^{-2}$ for H5N1, while the value was $1.6{\times}10^{-8}$ for H1N1. The beta-Poisson DR model provided the best fit to five of 7 data sets tested, and the estimated parameter values in betabinomial model were very close to those of beta-Poisson. Our study indicated that beta-binomial or beta-Poisson model could be the choice for DR modeling of AI, even though DR relationship varied depending on the virus strains studied, as indicated in prior studies. Further DR modeling should be conducted to quantify the differences among AI virus strains.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.14
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• pp.5635-5641
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• 2015

Background: Cirrhosis is regarded as a possible end stage of many liver diseases, including viral infection. It occurs when healthy liver tissue becomes damaged and is replaced by scar tissue and finally may lead to hepatocellular carcinoma. Interferons (IFNs)are two general categories, type I and II. Type I includes one beta interferon and over 20 different alpha interferons. Alpha interferons are very similar in how they work, interacting with other proteins on cells like receptors. The main objective of this study was to compare Mx gene productivity post different cell line treatment with imported and Egyptian biosimilar locally produced IFNs, as well as the efficacy of those tested IFNs. Also, an assessment was made of sensitivity of different cell lines as alternatives to that recommended for evaluation of antiviral activity. Materials and Methods: Different cell lines (Vero, MDBK and Wish) were employed to evaluate cytotoxicity using the MTT assay. Antiviral activity was evaluated compared with standard IFN against VSV, Indiana strain -156, on tested rh-IFNs (imported; innovated and Egyptian biosimilar locally produced IFNs) in the pre-treated cell lines previously mentioned. The virus was propagated in the Wish cell line as recommended. Finally we estimated up-regulation of the Mx gene as a biomarker. Results: Data recorded revealed that test IFNs were safe in test cell lines. Viability was around 100%. Locally tested interferon did not realize the international potency limits, while the imported one was accepted compared with the standard IFN. These results were the same either using infectivity titer reduction assay or crystal violet staining of residual non- infected cells. Mx protein production was cell type related and confirmed by the detected Mx gene expressed in imported and locally produced IFN pre-treated cell lines. The expression of the gene was arranged in the order of Vero> wish > MDBK for the imported IFN, while for the Egyptian biosimillar locally produced one it was MDBK> Vero> wish. With regard to the antiviral activity there was a significant difference of imported IFN potency compared with the locally produced IFN (P<0.05), the IFN potential (antiviral activity) was not cell line related and showed non-significant difference for each separate product. Conclusions: Vero cells can be used as an alternative cell line for evaluation of IFN potency in case of unavailable USP recommended cell lines. Alternative potency evaluation assay could be used and proved significant difference in IFN potency in case of local and imported agents. Evaluation of antiviral activity could be used in parallel to viral infectivity reduction assay for better accuracy. Mx gene can be used as a marker for IFN potential.