• 한국동물위생학회지
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• 제16권2호
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• pp.103-110
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• 1993

The Aeromonas strains were isolated from diseased cultured catfsh (Silurus asotus) in the ponds near by Gochang of Chunbuk. The present isolates were identified as A. hydrophila based on their biological and biochemica1 characteristics. The isolates of A. hydrophila were named GC-1, GC-2, GC-3, GC-4 and GC-5, Five strains were grew optimally at temperatures $35^{\circ}C,$ pH 7.5 and in 0.5 to l% NaCl. This bacterium(GC-1) was injected into health catfish in order to prove the causative agent of ascites and haemorrhagic ulcers. The symptoms in cat fish infected by this challenge method were observed to be very similar to the symptoms of a natural infection, but controls did not show any abnormal symptoms during the experimental period. At 24 post-injection, the red spot developed around the injection site and the haemorrhagic ulcers was extended near the gill and ventral fin. Five strains were tested for drug sensitivity by plate method. All strains were sensitivity to gentamicin and resistant to penicillin, streptomycin and tetracycline.

• Fisheries and Aquatic Sciences
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• 제27권3호
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• pp.159-170
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• 2024

Research to obtain molecular markers related to the major histocompatibility complex (MHC) gene in both strains of gourami is essential to increase the success of the selection program of disease resistance traits. Using a completely randomized design (CRD), the challenge test consists of four treatments and seven replications. The treatment was Jambi gourami injected with PBS (KJ), Kalimantan gourami injected with PBS (KK), Jambi strain injected with Aeromonas hydrophila (GJ), and Kalimantan strain injected with A. hydrophila (GK). The GJ population was more resistant to A. hydrophila than the GK population. The MHC II gene was detected in both test strains (GJ and GK), both resistant and susceptible fish. However, there were differences in the results of amplifying the MHC II gene in susceptible and resistant fish. Two DNA fragments approximately 400 and 585 bp were detected in the genome of susceptible fish, while in the genome of susceptible fish, only one DNA fragment was detected (400 bp). Therefore, the MHC II gene fragment with a size of about 585 bp can be used as a potential candidate for specific molecular markers to obtain resistance to A. hydrophila bacteria in the giant gourami.

• 한국환경과학회지
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• 제12권10호
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• pp.1079-1084
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• 2003

This study was carried out to check changes of components in the slaughter waste by the bacteria isolated from slaughter wastes from Gyungnam Province from May to June 2000, and to find usefu] organism for treatment of the waste. Bacteria used in this study were Aeromonas hydrophila, as the dominant of the waste. Optimum conditions for bacterial culture were obtained as the temperature of 35$^{\circ}C$, pH 6.5, and shaking of 120 rpm in nutrient broth. The mean values of dissolved oxygen was 4.14 mg/1; biochemical oxygen demand, 1731.21 mg/1; ratio of BOD/COD, 0.53-0.64; ratio of T-P/T-N, 1.0-1.41; and viable counts of the waste, 5.47${\times}$10$\^$7/ CFU. Little change in total nitrogen observed by 36 hr of the culture. The largest amount of increasing NH$_4$$\^$+/-N was observed in the sample that 10% of the waste added in nutrient broth with A. hydrophila showing the value of 29.19 mg/l at the beginning to 570.36 mg/1 by 36 hr of culture. However, the highest increasing ratio between initial amount and finals at 36 hr of culture showed as 41.6 times when 3% of the waste added. NO$_3$ -N was decreased showing the value of 71.27 mg/1 to 32.14 mg/1 by 24 hr of culture with the organism when 10% of the waste added in nutrient broth. Total phosphorus was decreased showing the value from 188.74 mg/1 to 101.41 mg/1 after 12 hr of culture with the organism when 5% of the waste added in nutrient broth, while T-P was decreased gradually by 24 hr of culture from 193.8 to 101.4 mg/1 when 10% of the waste added.

• Journal of Microbiology
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• 제35권4호
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• pp.354-359
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• 1997

Methods for the extraction of DNA from water sample were approximated. Four different procedures of DNA extraction were carried out with pellets obtained from centrifugation of 4 liter water samples. The recovery efficiency and purity of DNA extracted by each method from different sources were compared. DNA yield varied with extraction methods, Method I, which involves enzymatic and freeze-thaw lysis steps and phenol and phenol-chloroform purification of extracted nucleic acid, showed a significantly higher yield and purity than the other methods. The use of glass beads in the DNA extraction methods improved the purity of DNA suitable for PCR. Bovine serum albumin in the PCR reaction mixture was useful in reducing inhibitory effects of contaminants. The efficiency of an extraction method was determined by the detection of the aer of Aeromonas hydrophila with PCR. The lower limit of detection of A. hydrophila from seeded tap water was 2 CFU/ml in PCR when method I was used for DNA preparation.

• 한국식품위생안전성학회지
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• 제23권1호
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• pp.68-72
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• 2008

Antimicrobial stability of grape seed extract ($ActiVin^{TM}$), pine bark extract ($Pycnogenol^{(R)}$), and oleoresin rosemary ($Herbalox^{(R)}$) on the growth of Aeromonas hydrophila was investigated in cooked ground beef. When compared to the control, the populations of A. hydrophila were most effectively reduced by 4.06 log CFU/g for 1% $Pycnogenol^{(R)}$ added after cooking at 10 days of refrigerated storage, followed by 3.06 log CFU/g for 1% $Pycnogenol^{(R)}$ added before cooking and 1.36 log CFU/g for $ActiVin^{TM}$. Bacteriostatic and bactericidal activities were observed for $Pycnogenol^{(R)}$ added before and after cooking, respectively. $Pycnogenol^{(R)}$ consists of heat-labile and heat-stable compounds. $ActiVin^{TM}$ and $Pycnogenol^{(R)}$ could be considered for use as multifunctional preservatives in meat and meat products.

• 한국수의병리학회지
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• 제5권2호
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• pp.75-78
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• 2001

A dead nine-month-old female hooded crane (Grus monachus) fecund in Chonnam province was examined pathologically, bacteriologically and toxicologically. Pathologically multiple necrotic foci consisting of infiltration of heterophil, lymphocytes and macrophages, and exudation of fibrin were observed in liver. Kidney had multiple hemorrhagic foci. Aeromonas hydrophila identified by biochemical properties was isolated. Phosphamidon, a kind of organophosphate, was detected massively in feed content of gizzard. From these results, lethal ingestion of phosphamidon was a causative agent of death. In addition, future study has to be done about correlation between liver necrosis and A. hydrophila infection.

• 한국미생물·생명공학회지
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• 제44권2호
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• pp.130-139
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• 2016

지렁이의 장내로부터 분리한 미생물 중에서 지질을 가수분해하는 활성이 높은 미생물을 선발하였으며, 동정하여 Aeromonas hydrophila PL43으로 명명하였다. A. hydrophila PL43이 생산하는 지질분해 효소의 정제는 황산암모늄 침전, DEAE-sepharose FF 이온교환 크로마토그래피, Sepharose S-300HR 겔 크로마토그래피 단계로 수행하였으며 최종적으로 정제한 지질분해 효소는 p-nitrophenyl butyrate (pNPB)를 기질로 사용했을 때, 84.5배로 정제되었고 효소 활성의 회수율은 3.7%이었다. p-nitrophenyl palmitate (pNPP)를 기질로 사용했을 때에는 56.6배로 정제되었고 효소 활성의 회수율은 2.5%이었다. SDS-PAGE를 수행한 결과, A. hydrophila PL43이 생산하는 지질분해효소의 분자량은 약 74 kDa으로 추정되었다. 지질분해 효소의 pH에 대한 영향은 pNPB와 pNPP 기질에서 pH 8.0에서 최대활성이 보였고 pH 7.0−10.0에서 안정하였다. pNPB를 기질로 사용한 경우에는 50℃에서 pNPP를 기질로 사용한 경우는 60℃에서 최대 활성을 나타냈으며, 정제한 지질분해 효소는 20−60℃에서 안정성을 나타내었다. 정제한 지질분해효소는 금속이온 Co²⁺, Cu²⁺, Fe²⁺에 의해서 효소활성이 억제되었으며, EDTA의 metal chelating에 의해 활성이 회복되었다. Inhibitor에 의한 저해는 효소 활성부위의 serine 잔기와 결합하여 효소 활성을 억제하는 PMSF에서 가장 우수하였으며 효소 활성부위의 aspatyl 잔기에 결합하여 효소활성을 억제하는 pepstatin A는 농도가 높아짐에 따라 효소활성을 저해하였다. 따라서 정제한 지질분해 효소는 활성부위에 serine 잔기와 aspartyl 잔기가 있는 것으로 사료되었다. 정제한 지질분해 효소의 K_m 값과 V_max 값은 pNPB를 기질로 사용 했을 때 K_m 값과 V_max 값은 1.07 mM과 7.27 mM/min이고, 기질이 pNPP일 때 K_m 값과 V_max 값은 1.43 mM 과 2.72 mM/min이었다.

• 한국어병학회지
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• 제10권2호
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• pp.75-86
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• 1997

어류의 감염 조직으로부터 edwardsiellosis의 원인균인 Edwardsiella tarda를 whole cell 자체로 직접 검출할 수 있는 solid phase ELISA법을 연구하였다. A. hydrophila ATCC7966, V. anguillarum HUFP5001, Y. ruckeri 11-4, E. ictaluri 및 Streptococcus sp. NG8206 등의 어병세균에 대해 ELISA법으로 실시한 교차반응 분석에서 A. hydrophila ATCC7966 균주와 V. anguillarum HUFP5001 균주가 E. tarda Edk-2에 대한 토끼 항혈청에 대해 높은 교차반응을 나타내었으나, 항혈청을 A. hydrophila ATCC7966 FKC로 흡착시킴으로써 교차반응을 제거할 수가 있었다. 그러나, 응집항체가 측정 결과와는 달리, ELISA 분석에서는 E. tarda 분리 균주간의 교차반응이 매우 높은 것으로 나타났다. Tissue homogenate내에 있는 항원을 검출함에 있어, 조직내의 지질이나 단백질 성분이 함께 분석용 plate에 coating되어 감도가 훨씬 감소하므로 ELISA법의 적용을 위해서는 감염 조직의 homogenate를 PBS에 100배 이상 희석한 후 진단을 실시해야 하는 것으로 나타났다. Tissue homogenate내에 있는 생균을 항원으로 하여 직접 검출할 때에는 검출한계가 $1{\times}10^3$ cells/ml로 나타나 FKC 항원의 사용에 비하여 더 증가된 감도를 보여주었다. 결론적으로 본 ELISA법은 양식장에서 발생한 edwardsiellosis를 진단함에 있어서 특이적이고 신속하며 민감한 방법으로 확인되었다.

• 한국어병학회지
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• 제9권1호
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• pp.79-85
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• 1996

$\beta$-glucan의 투여가 세균감염증에 대한 저항성에 미치는 영향을 알아보기 위하여 복강주사 또는 침지에 의해 한국산 메기(Silurus asotus)에 투여하였다. 투여 농도는 어체중 100 g 당 200, 500, $1000{\mu}g$을 1회 또는 3일 간격으로 2회 복강주사하거나, $100{\mu}g$/ml의 $\beta$-glucan 부유액에 30분 또는 1시간 침지시켰다. $\beta$-glucan 투여 3일후에 Edwardsiella ictaluri와 Aeromonas hydrophila의 생균액($2{\times}106$ CFU/0.1 ml)을 복강주사한 다음 10일간 사육하면서 생존율을 조사하였다. 복강주사와 침지에 의한 투여결과 복장투여만이 생잔율을 높일 수 있었으며, 투여 농도에 있어 어체중 100 g당 $200\sim1000{\mu}g$의 범위에 있어서는 농도간에 차이가 없었다. 또한 투여회수는 1회 투여보다는 3일간격으로 2회 투여가 효과적이었으며, E. ictaluri보다는 A. hydrophila에 대한 저항성이 높은 것으로 나타나, 한국산 메기에 $\beta$-glucan을 복강투여함으로서 세균감염증의 초기단계에 있어 생잔율을 높일 수 있었다.

• 한국어병학회지
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• 제22권3호
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• pp.317-326
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• 2009

This study has shown the screening of anti-bacterial activity of three Indian medicinal plant choloroform : methanol (50:50) solvent leaf extracts (i.e. Azadirachta indica, Ocimum sanctum, and Curcuma longa) with different concentrations (10, 5, 2.5, 1.25, 0.625, 0.312, and 0.156 mg/ml) under in vitro conditions against fish pathogenic bacteria, Aeromonas hydrophila, Streptococcus iniae, Vibrio harveyi, V. anguillarum, and Edwardsiella tarda isolated from olive flounder farms, Jeju Island, South Korea. The anti-microbial activity of the A. indica and O. sanctum extracts yielded the zones of growth inhibition (ZI) was 3 and 1mm against A. hydrophila at concentration of 0.156 mg/ml when compared to that of tetracycline standard (3 mm). At highest concentration (10 mg/ml) of A. indica, O. sanctum, and C. longa, high inhibition was 9, 7, and 6 mm when compared to that of tetracycline (11 mm) against A. hydrophila. The minimum inhibitory concentration (MIC) of A. indica, O. sanctum, and C. longa at 0.156 mg/ml that yield 9, 10, and 13 CFU/ml for A. hydrophila, 16, 22, and 25 CFU/ml for S. iniae and 18, 22, and 23 CFU/ml for E. tarda compared to the tetracycline. At highest concentration (10 mg/ml) of the three extracts was better inhibiting the growth of A. hydrophila, S. iniae and E. tarda. A. indica, O. sanctum, and C. longa were determined to the potential antioxidant activityon the basis of their scavenging activity of the stable 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical. A. indica extract was 0.625 mg/ml which indicated that the strong anti-oxidant activity. However, O. sanctum and C. longa extracts showed weak anti-oxidant activity at this concentration. Hence, in vitro assay among the pathogens, A. hydropila is better inhibitory activity of the extracts. It is evident that the Indian medicinal plants extracts were subjected to its effectiveness against A. hydrophila, S. iniae, and E.tarda at low concentrations. The obtained results in the present study suggested that the Indian plant extracts is a prevention tools for Korean olive flounder aquaculture pathogens and its need further advance investigation.