• 대한수의학회지
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• 제39권2호
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• pp.318-326
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• 1999

Respiratory pathogenic effects of several porcine reproductive and respiratory syndrome virus(PRRSV) isolates were examined in swine tracheal ring(STR) cultures by examining their effect on ciliary activity. One high and one low pathogenic PRRSV isolates were then selected and their pathogenicity investigated in 3-week-old conventional PRRSV-seronegative pigs. Ten pigs each were inoculated intranasally with the high or low pathogenic PRRSV isolate and 6 pigs were sham inoculated as negative controls. Two pigs each from the inoculated group and one pig each from negative control group were killed on 4, 7, 14, 21 and 28 days postinoculation(pI). At necropsy, degrees of gross lung lesion was determined. Turbinate, tonsil, trachea and lung samples were collected for virus isolation or histopathology. Gross lung lesions were observed mainly on 14 days PI with high and low pathogenic isolates inducing moderate diffuse and mild gross lung lesions, respectively. Inoculation of either the high or low pathogenic virus resulted in loss of cilia in ciliated epithelium of turbinates and trachea between 7 and 28 days PI. High pathogenic virus caused increased number of Goblet cells in the tracheal epithelial layer between 4 and 21 days PI whereas the low pathogenic virus did it between 14 and 28 days PI and with a lesser degree. Although both viruses produced interstitial pneumonia, the lesion was less severe with the low pathogenic virus. The isolation of high pathogenic virus from tissues and sera was earlier and more consistent than that of the low pathogenic virus. The agreement between in vitro and in vivo tests indicates that STR cultures may be used as a routine method to determine the respiratory pathogenicity of PRRSV isolates.

• 한국어병학회지
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• 제37권1호
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• pp.133-138
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• 2024

This study is a report on combinational effects between four sesquiterpene lactones (SLs) from bay laurel (Laurus nobilis) leaves, and oxytetracycline (OTC) or amoxicillin (AMX) against four fish pathogenic bacteria such as Vibrio anguillarum, V. harveyi, Edwardsiella tarda, and Streptococcus iniae. Individually, four SLs exerted little antibacterial activity against fish pathogenic bacteria. However, when combined with OTC or AMX, they showed synergistic interaction against pathogenic bacteria. Especailly, zaluzanin C (1) reduced the MIC of OTC (or AMX) eight-fold. Our results showed that combinations of SLs with antibiotics (ABTs) are more effective than ABTs alone to control pathogenic bacteria. The highest synergistic effect was observed when zaluzanin C (1) was combined with OTC or AMX against V. harvey or S. iniae, displaying significant reductions of MICs up to 8-fold (0.125 to 0.015 ㎍/mL and 0.0078 to 0.0009 ㎍/mL). In addition, zaluzanin C (1) improved the antibiotic potency of OTC against OTC resistant V. harveyi (250 ㎍/mL to 62.5 ㎍/mL). Synergism between ABTs and phytochemical such as SLs could be a therapeutically helpful concept to improve the efficacy of ABTs and prevent antibiotic resistance. These results suggest that SLs can be used as an alternative to reduce antibiotic resistance in aquaculture.

• 한국임상수의학회지
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• 제24권2호
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• pp.130-136
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• 2007

Artemisia capillaris THUNB is a perennial herb that belongs to the family Compositae spp and the most common plant among the various herbal folk remedies used in treatment of abdominal pain, hepatitis, chronic liver disease, jaundice and coughing in Korea. In this study, antimicrobial effects of Artemisia capillaris extracts on the food poisoning bacteria were investigated for further clinical application, which is an alternative for the use of antibiotics and their unexpected resistance. Artemisia capillaris extract using ethyl acetate showed the highest antimicrobial effects on S. enteritidis, E. coli O157 : H7, L. monocytogenes and S. aureus. The chloroform extract showed strong effects on all kinds of bacteria; whereas ethanol and methanol extracts showed weaker effects. Finally, ether and water extracts showed the weakest effects under the same conditions. The minimum inhibitory concentration (MIC) of ethyl acetate extract was 1 mg/mL for E. coli O157 : H7 and L. monocytogenes, and 2 mg/mL for S. enteritidis and S. aureus. The inhibitory effects on all the bacteria continued for 12 hours after incubation using 20 mg/mL and 30 mg/mL of ethyl acetate extract. The inhibitory effects continued maximally for 72 hours. The results of these studies indicate Artemisia capillaris extract exhibited excellent antimicrobial and inhibitory effects on the food poisoning pathogenic bacteria; S. enteritidis, E. coli O157 : H7, L. monocytogenes and S. aureus.

• 식물병연구
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• 제15권2호
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• pp.130-133
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• 2009

Nano-silver 용액의 식물병원성 세균에 대한 항균 활성 검정을 하기 위해 Clavibacter michiganensis subsp. michiganensis를 포함한 10가지 균주를 대상으로 실험을 수행 하였다. Nano-silver용액은 바이오 (주)플러스에서 제공된 WA-CV-WA13B, WA-AT-WB13R과 WA-PR-WB13R용액을 사용하였으며, 10 ppm, 25 ppm, 50 ppm, 100 ppm 농도로 nano-silver 용액을 배지에 첨가하여 nano-silver 배지를 제조한 후 실험대상 세균 균주를 72 h 배양 후 생장억제 정도를 관찰하기 위하여 세균의 colony 수를 세었다. 실험 결과, WA-CV-WA13B 용액의 경우 C-1에 대하여 10 ppm에서도 높은 생장 억제 효과를 나타냈고, P-6, X-1, 그리고 X-2에 대해서도 생장억제 효과를 나타냈고, WA-AT-WB13R용액의 경우 10 ppm의 농도에서 P-6에 대하여 살균효과가 나타났다. 10 ppm의 농도에서는 C-1, X-1, 그리고 X-2에 대해서 약간의 생장억제 효과가 관찰 되었다. WA-PR-WB13R용액의 경우 10 ppm 혹은 그이상의 농도가 P-5, P-6, 그리고 X-2 균주에 대하여 살균효과를 나타내었다. 실험에 사용된 3가지 nano-silver 용액 모두 25 ppm 이상에서 모든 실험대상 식물병원성 세균에 대하여 살균효과를 나타내었으며, 이러한 결과는 nano-silver 용액을 식물병원성 세균의 방제제로 활용할 수 있는 가능성을 보여주는 결과라고 판된다.

• Natural Product Sciences
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• 제17권2호
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• pp.160-164
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• 2011

The purpose of this investigation was to extract the bioactive agents from Alpinia officinarum Hance. The methanol with ethylacetate extracts alone and combined were examined for their activities against VRE (vancomycin-resistant enterococci) and pathogenic yeast in vitro. The incidence of infections caused by VRE and other pathogenic microorganisms and the importance of using novel synergistic drug combinations has become important. Previously, we reported the antimicrobial effects of the butanol extract from Lonicera japonica and have evaluated combinations of solvent extracts, with a focus on the MeOH and EtOAc extracts from A. officinarum. In the present study, enhanced inhibitory effects were achieved by employing a combination of the two solvent extracts. The MeOH and EtOAc combination was especially effective against four VRE strains: E. faecalis (K-10-22), E. faecaium (K-11-212), E. faecalis (K-10-57) and E. faecalis (K-10-361) with MIC values of 12.5, 12.5, 6.25 and 25 ${\mu}g/ml$, respectively. Thus, the combination was more effective than other antibiotics such as kanamycin, gentamicin or tetracycline against bacteria including E. coli, Staphylococcus aureus, and Micrococcus luteus. In addition, the combination was effective against yeasts such as Candida albicans, Candida tropicalis and Cryptococcus neoformans.

• 대한의생명과학회지
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• 제17권3호
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• pp.173-176
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• 2011

Free-living Acanthamoeba are eukaryotic protozoan organisms that are widely distributed in the air, water, etc such as environment. Acanthamoeba ingest the Escherichia coli which will replicate in cytoplasm of Acanthamoeba. Bacterial pathogenicity or virulence is one of important determinant factors to survive in free-living Acanthamoeba and otherwise Acanthamoebic pathogenicity is also an important factor for their interactions. Bacterial association with pathogenic strain of Acanthamoeba T1 and T4 was lower about two times than non-pathogenic T7. Bacterial invasion percentages into T1 were higher about three times than T7 but bacterial survival in T7 was increased as T1. The capsule-deletion mutant exhibited limited ability for invasion/uptake by and survival inside pathogenic Acanthamoeba T4. E. coli-outer membrane protein A (OmpA) decreased bacterial association with A. castellanii by about three times and it had higher effects than lipopolysaccharides (LPS). Under favorable conditions, the mutants were not survived in Acanthamoeba up to 24 h incubation. Therefore, this review will report pathogenic and non-pathogenic Acanthamoeba strains interactions with E. coli and its several mutants, i.e., capsule, OmpA and LPS.

• 한국초지조사료학회지
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• 제18권2호
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• pp.133-142
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• 1998

This study was conducted to investigate the effects of antagonistic bacteria and pathogenic fungi on the growth of tall fescue(Festuca arundinacea Schreb.) in continuous cropping soil(CCS) and non-continuous cropping soil(NCCS). Tall fescue was established by seeding into pots of 11 cm in diameter and 9 cm in depth containing 1 : 1 mixture of soil and vermiculite, and cultivated at pots with antagonistic bacteria and pathogenic fungi in a vinyl house. The bacteria used in this study were Bacillus subtilis and hsants. B. subtilis was isolated and identified kern forage rhizosphere soil and fusants were isolated through cell hsion from B. subtilis and B. thwingiensis. B. subtilis was named as B. subtilis 101 and hsants were named as F-3, F-7 and F-8. In dark culture experiment, tall fescue inoculated with the antagonistic bacteria lived longer than that of control in both CCS and NCCS. However, tall fescue of CCS lived shorter than that of NCCS. Dry weight of tall fescue inoculated with the antagonistic bacteria was higher than that of tall fescue inoculated with pathogenic hngi in both CCS and NCCS(P< 0.05), and the antagonistic bacteria showed positive effects on the growth of tall fescue. However, Dry weight of tall fescue was decreased by the inoculation of the pathogenic b g i in both CCS and NCCS(P< 0.05).

• 한국융합학회논문지
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• 제12권4호
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• pp.201-206
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• 2021

고병원성 조류독감 바이러스(H5N1)에 대한 피해가 지속적으로 증가하고 있으나, 이에 대한 항바이러스성 연구는 부족한 상황이다. 본 연구에서는 폴리에틸렌 필름에 Cu/TiO2 광촉매를 코팅하여 H5N1에 대한 항바이러스 특성을 분석하였다. 시료는 광촉매 마스터배치를 제조하여 압출코팅기에서 280℃로 3중 레이어 폴리에틸렌 원단의 양면을 코팅하였다. 그 결과 황색포도상구균과 대장균의 균수가 99.9% 감소되는 것으로 나타났다. 특히 인체감염이 가능한 H5N1형 고병원성 조류인플루엔자는 Cu/TiO2계 필름에 접촉 5분 이내 99.9% 감소하는 것으로 확인되었다. 광촉매를 코팅한 필름의 항균성에 대해서는 알려져 있지만 본 연구를 통해 항바이러스성에 대해서도 확인이 가능하였다.

• 대한한방부인과학회지
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• 제19권4호
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• pp.33-46
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• 2006

Purpose : This study was conducted to investigate effects of 7 herbs among medicinals resolving dampness with aroma on vaginal microorganisms. Methods : Staphylococcus aureus, Methicillin- resistant Staphylococcus aureus, Candida albicans and Gardnerella vaginalis were used for vaginal pathogenic microorganisms. Lactobacillus gasseri, Streptococcus spp. and Escherichia coli HB101 were used for vaginal flora. Medicinals resolving dampness with aroma, Pogostemonis Herba, Amomi Cardamomi Fructus, Amomi Semen, Atractylodis Rhizoma, Ammomi Tsao-ko Fructus, Alpiniae Katsumadaii Semen and Magnoliae Cortex were used in this study. In vitro antimicrobial activities were observed by optical density and colony test. Results : The optical density showed that Alpiniae Katsumadaii Semen and Magnoliae Cortex among medicinals resolving dampness with aroma had antimicrobial effects on pathogenic vaginal microorganisms (Methicillin-resistant Staphylococcus aureus). Pogostemonis Herba, Ammomi Tsao-ko Fructus had antimicrobial effects on Gardnerella vaginalis. The colony test showed that Alpiniae Katsumadaii Semen, Magnoliae Cortex among medicinals resolving dampness with aroma had antimicrobial effects on Methicillin-resistant Staphylococcus aureus. Pogostemonis Herbs, Alpiniae Katsumadaii Semen had antimicrobial effects aganist Gardnerella vaginalis. The optical density showed that Magnoliae Cortex among medicinals resolving dampness with aroma had antimicrobial effect on normal vaginal microorganisms (Streptococcus spp.). The colony test showed that medicinals resolving dampness with aroma had no antimicrobial effect on normal vaginal microorganisms. Conclusion : From this study, we could suggest that Pogostemonis Herba, Ammomi Tsao-ko Fructus, Alpiniae Katsumadaii Semen, Magnoliae Cortex of medicinals resolving dampness with aroma are available to antimicrobial agent of pathogenic vaginal microorganisms in vitro.

• Journal of Dairy Science and Biotechnology
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• 제15권1호
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• pp.11-20
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• 1997

병원성 대장균(炳原性 大腸菌) O157:H7에 대(對)한 유산균 발효유(乳酸菌 醱酵乳)의 발육억제효과(發育抑制效果)에 관한 실험(實驗)을 시도(試圖)하여, 標準 유산균(標準 乳酸菌)의 균주(菌株)로는 Lactobacillus bulgaricus, L. acidophilus 그리고 L. cormatus를 이용하여 BL broth에 각각(各各)의 유산균주(乳酸菌株)와 대장균(大腸菌) O157:H7의 수(數)(10$^5$/ml)를 동일(同一)하게 접종(接種)하고 시간별(時間別)로 관찰(觀察)한바 배양(培養)된지 대략(大略) 18시간 전후(時間 前後)하여 대장균(大腸菌)의 발육(發育)이 억제(抑制)되었고, 시판유산균 발효유(市販乳酸菌 醱酵乳) 3종(種)에 접종(接種)된 병원성 대장균(炳原性 大腸菌) O157:H7 (10$^8$/ml)은 접종(接種)된지 대략(大略) 140${\sim}$200분내(分內)에 발육(發育)이 억제(抑制)되었음이 관찰(觀察)되었다. 이상(以上)의 결과(結果)를 미루어 보아 유산균 발효유(乳酸菌 醱酵乳)는 병원성 대장균(炳原性 大腸菌)O157:H7에 대(對)하여 생성(生成)된 산(酸)에 의(依)한 억제작용(抑制作用)과 일부 미지(一部 未知)의 항균물질(抗菌物質)에 依(依)한 부가작용(附加作用)이 있었을 것으로 믿어 계속적(繼續的)인 추구(追究)가 요망(要望)된다.