• 한국임상수의학회지
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• 제21권3호
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• pp.248-252
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• 2004

DNase activity from infective larvae of the parasitic nematode Haemonchus contortus was characterized and compared to that from whole worm. DNase activity from infective larvae was detected throughout pHs 4-10, but high activity was detected under acidic conditions. The activity was not inhibited by 10 mM EDTA at pH 5.0, but was significantly inhibited at pH 7.0. The activity produced DNA, fragments with mixtures of 3'-hydroxyls (OH) and 3'-phosphates (P) at each pH with predominance of 3'-P. A unique DNase activity at 37 kDa was identified from infective larvae on zymograms. The 37 kDa DNase was detected only at pH 5.0, but not at pH 7.0, and this activity was not inhibited by EDTA at pH 5.0. These characteristics of the 37 kDa infective larval DNase resemble those of classic acidic DNases (e.g., DNase II). In contrast, 34, 36 and 38.5 kDa DNase activities were shown to be specific for whole worm. This result demonstrated that DNases in H contortus are regulated during development.

• 대한수의학회지
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• 제15권1호
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• pp.51-55
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• 1975

In this study two sets of experiments were undertaken. Firstly, the embryonated eggs and first-stage larvae, sprayed in disinfected soil, were exposed to different temperatures. Then, the viabilities of them were weekly determined by inoculating the soil to earthworms, Eisenia foetida. Secondly, the infective larvae, seperated from the earthworms and suspended in tap water, were also exposed to different temperatures and their viabilities were checked microscopically at weekly intervals. The results were summerized as follows: 1. The maximum longevities of embryonated eggs and first-stage larvae were determined as 1 week at $35^{\circ}C$, over 36 weeks at $25^{\circ}C$, $15^{\circ}C$, and $5^{\circ}C$, 32 weeks at $-5^{\circ}C$, and under 1 week at $-15^{\circ}C$. 2. The mean numbers of infective larvae detected from the test earthworms were greatest at $5^{\circ}C$, and decreased with rise or fall of the temperature. 3. Infective larvae freed from the intermediate host were able to survive for 2 weeks at $25^{\circ}C$ and 3 weeks at $15^{\circ}C$. However, they lost their viabilities in a week at $35^{\circ}C$, $5^{\circ}C$, $-5^{\circ}C$, and $-15^{\circ}C$. 4. The number of living infective larvae at $15^{\circ}C$ was greater than at $25^{\circ}C$.

• 대한수의학회지
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• 제11권1호
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• pp.1-39
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• 1971

The purpose of present study was to investigate the possibility to immunize guineapigs and swine against Metastrongylus apri infection by the administration of irradiated infective larvae. Four main experiments were undertaken. Firstly, three groups of infective larvae irradiated at $3{\times}10^4r$, $4{\times}10^4r$, and $5{\times}10^4r$ respectively were inoculated to guineapigs and their immunogenic effects were examined from the clinical, anatomical, and serological viewpoints to decide the optimal dose of X-ray for the atenuation of them. Secondly, the migratory behavior of the larvae irradiated at the optimal dose was compared with that of normal infective larvae. Thirdly, pigs were inoculated with each 5,000 infective larvae irradiated at the optimal dose and the clinical, anatomical and serological responses of them before and after challenge were examined. Fourthly, the heated extract of adult M. apri which had been used as an antigen in the serological examinations was analyzed and compared with that of adult Ascaris suis and of adult Trichuris suis by immunoelectrophoretic method. The results obtained are summerized as follows: 1) The optimal dose of X-ray for the atenuation of the infective larvae which can minimize the pathogenecity but keep the antigenecity of the infective larvae was $5{\times}10^4r$. 2) Guineapigs could become completely resistant to subsequent challenge infection by the administration of 1,000 infective larvae irradiated at $5{\times}10^4r$, without showing any symptom of disease before and after the challenge. 3) There were some indication that guineapigs could acquire complete immunity after they overcome the infection with normal infective larvae. 4) It was shown that, in guineapigs, the $5{\times}10^4r$-irradiated larvae can migrate to the large intestine and mesenteric lymph node within a day, where they stay for as long as 16 days to stimulate the host's immunity. 5) It also was shown that, in guineapigs, the normal infective larvae challenged to resistant guineapigs can migrate to the large intestine and mesenteric lymph node, where they are affected by the immune mechanism of host within 10 days without further migration. 6) Pigs could become partially resistant to subsequant challenge by the administration of 5,000 infective larve irradiated at $5{\times}10^4r$; no clinical symptom occurred after the administration, but milder symptoms of parasitic bronchitis were observable after the challenge infection and fewer number of worms were detected from the lungs at autopsy compared with severe symptoms and much number of worms in control pigs. 7) It was shown that, in pigs, a few of the $5{\times}10^4r$-irradiated larvae can migrate to the lungs, where they stay for as long as 104 days in stunted and sterile states; their body-lengths were short and their uteri developted no eggs. 8) There was evidence that the male larvae were more susceptible to X-ray than the female larvae. 9) Antibodies relating to the administration with $5{\times}10^4r$-irradiated or normal larvae were detected from the sera of both guineapigs and pigs by means of indirect haemagglutination and agar diffusion precipitin tests. Relatively higher antibody titers were recorded by the former test, but precipitin bands were demonstrable only when the positive sera were concentrated in one tenth of original volume in the later one. 10) The antibody titers of pig sera began to rose on 14 days, kept their peak during the period from 14 th day to 21st day, and fell to a low level on 28 days after the administration of $5{\times}10^4r$ or normal infective larvae. 11) A slight increase in gamma globublin of the pig sera occurred following the administration. The gamma globulin level showed a tendency to fluctuate in acordance with the antibody level. 12) A marked eosionophilia occurred in pigs on 7 or 14 days following the administration. The eosinophil count showed the same tendency to fluctuate as the gamma globulin did. 13) It was shown that the serum antibodies detected by the heated extract of adult Metastrongylus apri react crossly with the heated extract of adult Ascaris suis but not with that of adult Trichuris suis in indirect haemagglutination and agar diffusion preciption reactions. 14) The heated extract of adult Metastrongylus apri could he divided into 9 antigenic components by immunoelectrophoresis, one (arc 4) of which was shown to be common to both extracts of adult Ascaris suis and adult Trichuris suis, and the other one (arc 9) to only the extract of adult Ascaris suis.

• 대한수의학회지
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• 제11권2호
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• pp.157-161
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• 1971

This experiment was undertaken in order to investigate whether chicken can serve as a carrier for swine lungworm, Metastrongylus apri. The results abtained are summerized as follows: All chickens which were fed the infective larvae of M. apri, in the form of infected earthworm (Eisenia foctida) excreted appreximately 4.4 to 5.4 percent of the infective larvae in their feces between 2 to 10 hours after dosing. The larval excretion was marked especially during the first 2 hours. A few (0.10~0.12%) larvae were detected from the intestinal wall of chickens by pepsin-digestion method on a day after dosing, but no further migration or development of the larvae was observed. The larvae which had passed through the digestive tract of chickens retained their viability and produced characteristic lungworm disease when inoculated to guineapigs. From these results, it may he concluded that the chicken can serve as a carrier for the infective larvae of M. apri.

• 대한수의사회지
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• 제21권1호
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• pp.43-47
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• 1985

Striking effects of hydrocortisone were observed on the behaviour of Toxocara canis larvae in 2 months old dogs. Four cross-breed dogs were used in this studies and each dog was inoculated 3000 infective eggs. The larvae were recovered from 2 dogs (contro

• 대한수의사회지
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• 제21권10호
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• pp.612-616
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• 1985

A prominent effect of prolactin was observed on the migration behaviour of T.canis larvae in 2 months old puppies, Four cross- breed puppies were used in this studies and each puppy was infected with 3000 infective eggs. One of 4 puppies used for control

• Parasites, Hosts and Diseases
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• 제36권1호
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• pp.15-22
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• 1998

Strongyloides venezuelensis을 자유생활형 유충을 얻고자, 쥐의 분변 물질을 첨가한 영양 배지를 polyvinyl bag에 넣어 배양하는 배양기술을 확립하였다 포화식염수법으로 회수한 충란의 부화율은 배양 온도에 따라서 다르게 관찰되었는데 (Y = $-0.192X^2$ + 8.673x - 19.550, r = 0.901) $^25{\circ}C$에서 100% 부화율을 나타내었지만 온도가 낮거나 높아도 감소되는 양상을 나타내었다. 회수 한 충란 $^20{\circ}C$에서 5일간 관찰하였을 때 자유생활형 유충으로의 발육률은 영양 배지의 농도를 증가시키면 증가하여 0 12%에서 최고치를 보이다가 다시 낮아지는 양상을 보여 (Y = $-864.032X^2$ + 245.995X - 0.560, r = 0.875), 감염형 3기 유충($L_3$)으로의 발육률은 배양 온도에 따라서 다르게 관찰되었다 즉, $^25{\circ}C$에서 가장 높아서 20%에 달하며 $15^{\circ}C$는 10.9%, 그리고 $^20{\circ}C$에서는 18.1%로 나타났다 (Y = $-0.189X^2$ + 8.387x - 72 795 r = 0.981). 그렇지만 감염 유충으로 성장하는데 필요한 기간도 역시 온도의 변화와 관련이 있어 온도가 높으 면 높을수록 소요되는 시간이 잔게 나타났다 (Y = $0.035X^2$ - 2.025X + 32.375, r = 0.995) 이상의 결과로 미루어 보아 감염 유충의 최대 회수율 (19.2%)은 15,000개를 polyvinyl bag에 0.12% 영양 배지와 더불어 $^25{\circ}C$에서 5일간 배양하였을 때 얻을 수 있었다. 이처럼 새로이 고안한 Skonavloides 속의 기생충 배양 기술은 화학 물질, 구충제, 제초제에 대한 선별검사와 기생충과 관련된 면역학적 연구에 생물학적 도구로서 사용될 수 있을 것으로 기대된다. 저자는 S. venezuelensis의 국문 이름을 베네수엘라분선충으로 제안한다.

• 한국토양동물학회지
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• 제5권2호
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• pp.97-100
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• 2000

본 연구는 곤충기 주에서 증식된 감염태 곤충병원선충(Steinernema carpocapae weiser)을 회수하는데 새로이 개량된 방법을 소개한다. 이 수거방법은 기주곤충에 감염태 선충을 접종 후 $25^{\circ}C$에서 증식시켰을 경우 최대의 감염태 밀도를 보이는 시기(6일후)에 기주곤충의 혈강을 노출시켜 수거함으로 빠른 속도로 감염태 유충을 회수하려는데 목적을 두었다. 또 이렇게 해서 빠져나오는 선충들중 가능하면 감염태 유충만 선별하여 걸러지도록 수거하게 했다(개량된 'Baermann'깔대기법).기존의 방법은 증식된 기주를 처리없이 'White trap'에 설치하여 놓고 스스로 표피를 뚫고 나오는 감염태 유충을 수거하여 왔다. 개량된 수거방법과 기존의 수거방법을 통해 나오는 감염태 유충의 총수거율과 병원력을 파밤나방 (Spodoptera exigua (H bner)) 5령 유충을 이용하여 비교하였다. 두 방법 모두에서 회수된 선충은 95% 이상이 형태적으로 감염태 유충이었다. 이들 감염태 선충의 기능적 분석을 위해 두 방법에서 회수된 감염태 유충을 파밤나방(Spodoptera exigua(H bner)) 5령충에 동일한 밀도로 처리했다. 이때 두 방법 모두 기주 살충력이나 일정시간 동안 기주 혈강속으로 침입하는 선충활동력에서 차이가 없었다. 그러나 감염태 유충의 총 수거밀도와 소요기간에 있어서는 타이를 보였다 기존의 'White trap'수거방법은 $25^{\circ}C$에서 6일동안 증식된 기주 파밤나방 1마리 당 10일 동안의 수거기간을 통해 약 20,000마리의 감염태 유충을 수거한 반면, 개량된 'Baer-mann'갈대기법을 이용한 수거방법은 불과 2일의 수거기간 동안 약 50,000마리의 총 수거 감염태 선충밀도를 보였다.

• Journal of Microbiology and Biotechnology
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• 제17권6호
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• pp.968-978
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• 2007

A pathogenic nematode, Butlerius sp., was isolated from Oriental beetle, Blitopertha orientalis. The infective juveniles exhibited dose-as well as time-dependent entomopathogenicity on the larvae of B. orientalis. Two bacterial species, Providencia vermicola (KACC 91278) and Flavobacterium sp. (KACC 91279), were isolated from the infective juveniles and identified. P. vermicola outnumbered Flavobacterium sp. in the nematode host, in which the colony density of P. vermicola was found to be 21 times higher than that of Flavobacterium sp. However, when the two bacterial species were cocultured in culture media without the nematode host, they showed similar growth rates. Both bacteria induced significant entomopathogenicity against Spodoptera exigua larvae infesting economically important vegetable crops, where P. vermicola was more potent than Flavobacterium sp.

• 한국토양동물학회지
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• 제8권1_2호
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• pp.17-22
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• 2003

국내에서 채집된 메기디스 곤충병원선충(Heterorhabditis megidis)을 이용하여 집파리(Musca domestica)와 풀색꽃무지(Gametis jucunda)에 대해서 방제 효과를 검정하였다. 페트리디시 실내실험에서 H. megidis는 집파리와 풀색꽃무지 2령충에 대해 각각 456.4 및 238.9 infective juveniles (IJs)/마리의 반수치사 농도를 보였다. 이는 이미 방제 효과가 잘 알려진 곤충병원선충인 Steinernema carpocapsae을 동일한 두 종에 처리하였을 때 얻은 반수치사 농도(집파리는 115.9 IJs/마리, 풀색꽃무지는 388.6 IJs/마리)와 대조되었다. 포장시험에서는 집파리가 발생하는 축산농가에 평방 미터당 1,000,000 IJs를 처리할 경우 56.9%의 방제 효과를 보였다. 반면에 풀색꽃무지가 발생되는 사과원에 평방 미터당 370,000 IJs를 처리할 경우 57.3%의 방제 효과를 보였다. 이러한 결과는 국내에서 발생하는 메기디스 곤충병원선충이 집파리와 풀색꽃무지에 대해서 효과적 생물방제 인자가 될 수 있는 것을 제시한다.