• The Journal of the Korean Society for Microbiology
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• v.21 no.1
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• pp.151-161
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• 1986

In order to develop sensitive and sepcific assay methods for E. coli heat labile enterotoxin(LT) hybridoma cell lines secreting LT specific monoclonal antibody were obtained. LT was purified from cell lysate of E. coli O15H11. The steps included disruption of bacteria by French pressure, DEAE Sephacel ion exchange chromatography, Sephadex G200 gel filtration, and second DEAE Sephacel ion exchange chromatography, successively. Spleen cells from Balb/c mice immunized with the purified LT and $HGPRT^{(-)}$ plasmacytomas, $P3{\times}63Ag8.V653$ were mixed and fused by 50% (w/v) PEG. Hybrid cells were grown in 308 wells out of 360 wells, and 13 wells out of them secreted antibodies reacting to LT. Among these hybridoma cell 1G8-1D1 cell line was selected since it had produced high-titered monoclonal antibody continuously. By using culture supernatant and ascites from 1G8-1D1 cells the monoclonal antibody was characterized, and an assay system for detecting enterotoxigenic E. coli was established by double sandwich enzyme-linked immunosorbent assay (ELISA). The following results were obtained. 1. Antibody titers of culture supernatant and ascites from 1G8-1D1 hybridoma cells were 512, and 102, 400, respectively by GM1-ELISA and its immunoglobulin class was IgM. 2. The maximum absorption ratio of 1G8-1D1 cell culture supernatant to LT was 90% at $300\;{\mu}g/ml$ of LT concentration. LT concentration shown at 50% absorption ratio was $103.45{\mu}g$ and the absorption ratio was decreased with tile reduction of LT concentration. This result suggests that monoclonal antibody from 1G8-1D1 hybridoma cell bound with LT specifically. 3. The reactivities of 1G8-1D1 cell culture supernatant to LT and V. cholerae enterotoxin(CT) were 0.886 and 0.142(O.D. at 492nm) measured by the GM1-ELISA, indicating 1G8-1D1 monoclonal antibody reacted specifically with LT but not with CT. 4. The addition of 0.1ml of ascites to 0.6mg and 0.12mg of LT decreased the vascular permeability factor to 41% and 44% respectively, but it did not completely neutralize LT. 5. By double sandwich ELISA using monoclonal antibody, as little as 75ng of the purified LT per ml could be detected. 6. The results by assay of detecting LT in culture supernatants of 14 wild strains E. coli isolated from diarrhea patients by the double sandwich ELISA were almost the same level as those by reverse passive latex agglutination.

• Journal of Animal Science and Technology
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• v.53 no.5
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• pp.451-459
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• 2011

The current study was conducted to determine the effects of herbal supplement on growth performances and diarrhea in Hanwoo calves. Total 24 Hanwoo calves (3 treatments: 8 calves per treatment) were randomly assigned to either Control (no treatment), Treatment 1 (0.3% herb supplement), or Treatment 2 (0.5% herb supplement) diets for 150 days. Total body weight gain and total feed intake per head in Treatment 1 was 142.8 kg and 545.9 kg, respectively, and it was higher (p<0.05) compared to other groups. The blood total cholesterol range was 86.43~97.00 mg/dl, triglycerides 13.26~13.86 mg/dl, GOT 76.97~79.60 mg/dl, GPT 19.54~20.97 mg/dl, WBC 8.75~9.95 k/${\mu}{\ell}$, RBC 10.14~11.91 M/${\mu}{\ell}$, and hemoglobin 10.74~11.20 g/$d{\ell}$, respectively, with no significant (p>0.05) differences among treatments. The blood immunoglobulin G levels were 5.74~6.05 mg/ml which tended to decrease as experimental period extended. Total number of pathogens in feces showed peaks at 1~2 months after the initiation of experiment, and tended to decrease thereafter. Total number of Eimeria spp., E. coli and BVDV in feces showed no significant differences but control group showed higher counts than both treatment groups. During overall period, the incidence of pathogenic diarrhea in calves of 2 treatment groups was much lower than control group calves (C: 24, vs T1: 9, T2: 13 heads), however, it was not significant (p>0.05). In conclusion, supplementation of herbs in Hanwoo calf diets might be beneficial to improve growth performances and prevent diarrhea.

• Food Science of Animal Resources
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• v.32 no.2
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• pp.228-233
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• 2012

This study was conducted to determine the effects of stevia (Stevia rebaudiana bertoni) and charcoal supplementation on growth performance, immune response and carcass characteristics of finishing pigs. A total of 420 pigs (LYD) were randomly allocated into 7 treatments with 3 replications. Dietary treatments were 1) T1 (basal diet), 2) T2 (basal diet+0.3% stevia), 3) T3 (basal diet+0.6% stevia), 4) T4 (basal diet+0.3% charcoal), 5) T5 (basal diet+0.6% charcoal), 6) T6 (basal diet+0.3% stevia+0.3% charcoal) and 7) T7 (basal diet+0.6% stevia+0.6% charcoal). During the experimental period, average daily gain (ADG) was higher in T2 and T6 groups than the other treatments (p<0.05). Feed conversion ratio (FCR) was higher in T6 group compared to the others (p<0.05). There were no significant differences in total cholesterol level and glutamic pyruvic transaminase (GPT) activity of blood among treatments. In glutamic oxaloacetic transaminase (GOT) activity, T3, T5, T6 and T7 groups showed lower values (p<0.05) compared to T1. Insulin-like growth factor-1 concentration was higher in T2 and T6 groups than the others (p<0.05), but there were no significant differences in immunoglobulin G, lymphocyte, eosinophil, basophil and atypical lymph levels among treatments. In neutrophil, T6 showed higher level compared to the others (p<0.05). In the carcass characteristics, T6 showed higher level of a carcass grade compared to the other treatments. However, carcass length did not show any significant difference among treatments. As a result, dietary supplementation of 0.3% stevia and 0.3% charcoal showed higher ADG, higher FCR and better immune response resulting in better growth performance and carcass characteristics of finishing pigs.