Vibrio parahaemolyticus (V. parahaemolyticus) has been recognized as a significant food-borne pathogen around the world. In this study, we investigated the prevalence and antimicrobial resistance of V. parahaemolyticus isolated from raw fishes. A total of 64 samples of raw fishes purchased from a traditional seafood market in Seoul, Korea. were examined for the presence of V. parahaemolyticus using intestines, gills, and fins. Twenty five grams of all samples were enriched in 225ml of alkaline peptone water at 37℃ for 24h and then streaked onto thiosulfate citrate bile sucrose agar. Suspected colonies were inoculated into triple sugar iron agar for biochemical screening test and were finally confirmed with API 20NE strip. Antimicrobial resistance tests were performed with disc diffusion method in accordance with National Committee for Clinical Laboratory Standard. Thirty three V. parahaemolyticus strains were isolated from raw fishes among 33 out of 64 (51.6%). Among 33 isolates, 16 isolates (48.5%) were resistant to ampicillin, 7 isolates (21.2%) were resistant to amikacin, and all isolates were not resist to other antibiotics such as amoxicillin & clavulanic acid, sulfamethoxazole & trimethopenem, ciprofloxacin, cefotaxime and cefepime. Although the prevalence of V. parahaemolyticus was high in raw fishes compared to other studies, antimicrobial resistance rate of the isolates was relatively low. These results could be useful information for risk assessment of V. parahaemolyticus in raw fishes.

Etofenprox에 대해 저항성과 감수성을 보이는 복숭아혹진딧물(Myzus persicae) 개체군을 가지고, 진딧물이 섭식하는 동안 약제에 노출되었을 때 반응하는 양상을 EPG패턴을 비교함으로써 처리된 약제에 대한 저항성 발달 여부를 검토하였다. 본 실험에서 사용한 복숭아혹진딧물 야외와 실내개체군은 etofenprox의 추천농도 처리 후 48시간에 각각 36.7과 86.7%의 살충율을 보였으며, 반수치사농도에 있어 30배 이상의 차이를 나타내어 야외에서 채집한 개체군의 경우 etofenprox에 저항성을 나타내는 개체군으로 사용하였다. 또한 교차저항성 발달 여부를 확인하기 위해 fenpropathrin 처리 후 살충율을 조사한 결과, 두 개체군 모두에서 각각 28%와 29%로 낮은 살충율을 보였으며, thiamethoxam에 대해서는 48시간 후에 저항성개체군이 57%, 감수성 개체군은 79%를 나타내었다. 또한 EPG 기록시작 후 1시간 뒤, 약제를 살포하고, potential drop, contact signal의 빈도 수, 총 섭식 시간, 총 구침을 빼고 있는 시간, pathway activity 패턴 등을 조사하였다. Etofenprox 처리 후 조사한 결과, 처리 전의 섭식행동에 있어서는 유사하였으나, 처리 후 저항성 개체군의 경우는 섭식 및 탐침 시간이 감수성 개체군에 비해 훨씬 길게 나타나 약제에 노출된 이후에도 활발히 일어나는 경향을 보였으며, fenpropathrin의 결과에서는 조사한 EPG 조사패턴 모두에서 두 개체군간 큰 차이를 보이지 않았다.

For the comparing of mortality of the resistance and susceptible population of Myzus persicae, etofenprox was treated in the recommended concentration of 200ppm. Mortalities of resistance population were 16.7 and 36.7%, and susceptible population were 86.7 and 86.7% after 24 and 48 hours treatment, respectively. For the detect of cross resistance to other pyrethroids, 6 pyrethroids were examined. Mortalities of susceptible and resistance populations were 90 and 31% to deltamethrin, 92 and 23% to lambda cyhalothrin, 81 and 14% to cypermethrin, 70 and 20% to α-cypermethrin, 29 and 28% to fenpropathrin, 84 and 29% to fenvalerate, respectively. It was showed that resistance populations were generally resistive to other pyrethroids. On the other hands, for recognized ecological characteristic of M. persicae susceptible and resistance populations life table was tested on the pepper leaves in the petri dish and on the plant in the pot. This results were showed that intrinsic rate of increase (r<SUB>m</SUB>), net reproduction number (R₀) and generation time in day (T<SUB>c</SUB>) were significantly different between two population in both tested. However, life span and reproduction period were slightly different between them. Otherwise, feeding behaviors were tested using EPG technique with non- and treated etofenprox. First potential drop time of susceptible and resistance population was 73.5 and 257.9 sec with non-treated and 93.3 and 1076.2 sec after treated, respectively. Electrical probing signals were 8.2 and 48.8 times with susceptible and resistance individuals after treated etofenprox, respectively. It was supposed that the resistance is more probings than susceptible population. After treated, total feeding time have more 6,728.9 sec on resistance than 965.5 sec on susceptible population. So, total non penetration time of susceptible population was 3,000 sec longer than resistance population.

복숭아혹진딧물(Myzus persicae Sulzer)은 넓은 기주범위를 가지고 있으며 이 들에 의한 피해는 섭식으로 인한 작물 생장저해와 감로 배설로 인한 그을음 병과 바이러스를 매개함으로서 심각한 피해를 주고 있는 해충으로 알려져 있 다. 이 해충에 등록되어 오랫동안 사용되어온 피레스로이드계열의 살충제는 인축에는 저독성이나 곤충에는 살충력이 강한 것으로 알려져 있다. 그러나 최 근 저항성이 나타남에 따라 복숭아혹진딧물의 방제를 위해 사용되는 etofenprox에 대한 복숭아혹진딧물의 저항성 개체군과 감수성 개체군을 비교하였다. 실험 방법으로는 etofenprox와 다른 성분의 합성피레스로이드 살충제를 사용하였고 life table, EPG 및 살충활성을 검정하였다. 사용 추천농도로 처리된 etofenprox의 분무 결과에 대한 살충율은 저항성 개 체군이 62%, 감수성개체군이 99%로 나타났다. 약제에 대한 감수성정도의 차 이를 보인 두 개체군간의 기주에서의 생태적 특성비교를 위해 Life table 실험 을 수행한 결과 저항성 개체군의 평균 수명은 15.6일, 성충이 되기까지의 기 간은 평균 4.7일, 산자력은 평균 46.8마리였고, 감수성 개체군의 평균수명은 17.9일, 성충이 되기까지의 기간은 평균 5.2일, 산자력은 평균 39.7마리였다. 다른 합성피레스로이드계열의 살충제 처리결과, 저항성 개체군이 deltametrin에 서 31%, lambda cyhalothrin에서 23%, cypermethrin에서 14%, α-cypermethrin에서 20%, fenpropathrin에서 28%, fenvalerate에서 29%로 나타났고, 감수성 개체군은 deltametrin에서 90%, lambda cyhalothrin에서 92%, cypermethrin에서 81%, α -cypermethrin에서 70%, fenpropathrin에서 29%, fenvalerate에서 84%로 나타났다. 약제 처리 후 섭식 반응을 알아보기 위하여 EPG system을 이용하여 섭식 반 응 시작 후 1시간 후에 etofenprox를 4,000배 농도로 처리했을 때 저항성 개체 군은 분무 후에 더 강하게 섭식을 보인 반면, 감수성 개체군은 섭식을 하지 않았다.

The susceptibility of five stink bugs species collected soybean fields in Milyang in 2006 to seven insecticides was evaluated using electric auto-sprayer. The insecticide deltamethirn had the lowest median lethal concentration (LC₅₀) of 0.4 to 2.3 ppm regardless of stink bugs species while phenthoate had the highest concentration for one-banded stink bug (Piezodorus hybneri), green stink bug (Nezara antennata), sloe bug (Dolycoris baccarum), and brown marmorated stink bug, (Halyomorpha halys), and fenthion for bean bug (Riptortus clavatus). The average LC₅₀ for stink bugs to seven insecticides was lowest at 7.5 ppm for R. clavatus, followed by 16.6 ppm for H. halys, 17.6 ppm for D. baccarum, 19.1 ppm for N. antennata, and 28.4 ppm for P. hybneri. The relative tolerance ratio (TR), which is the TR of 90 percent lethal concentration (LC₉₀) of stink bugs to the recommended concentration, was the lowest in fipronil for R. clavatus, P. hybneri and D. baccarum, fenitrothion for N. antennata, and fenthion for H. halys. The relative average TR was lowest at 0.09 for R. clavatus, followed by 0.26 for D. baccarum, 0.30 for N. antennata, 0.37 for P. hybneri, and 0.39 for H. halys. Therefore, insecticides susceptibility was highest for R. clavatus and lowest for P. hybneri while the relative average TR was lowest for R. clavatus and highest for H. halys. Accordingly, it is expected that stink bugs can be effectively controlled with by spraying insecticides in soybean field because the relative average TR value of stink bugs was below 1.0, indicating high susceptibility of stink bugs to insecticides.

One hundred isola tes of Staphylococcus aureus were obtained from feces samples of patients with food poisoning. The a ntibiotic susceptibility against vari ous antibiotics was examined by disc diffusion test . The S. aureus isolates had 92% resista nce to peni cillin. They also had 30% resistance to ampicillin and erythromycin. respect ively. The percentage of re sistance to oxacillin was 14%. Three vancomycin resistant isolates were also found. The minimal inhibitory co ncen tra ti on(MIC)s of antibiotics were examll1ed Antibiotics-intermediate S a ureus isolates were not det ected by disc dif fu sion t est

Laboratory tests were conducted to determine the susceptibility of the alfalfa weevil, Hypera postica to Korean entomopathogenic nematodes, Steinernema carpocapsae GSN1 strain (ScG), S. glaseri Dongrae strain (SgD), Heterorhabditis bacteriophora Hamyang strain (HbH), and Heterorhabditis sp. Gyeongsan strain (HeG) at the petri dish assay. The larval mortality of H. postica was significantly different depending on nematode species and treatment concentration. SgD and HeG strain were more effective against H. postica larva than ScG and HbH strain. When SgD and HeG strain were treated with the rate of ＞20 infective juveniles (ijs) per alfalfa weevil larva, mortality was ca. 77.5-100% at the late instars of H. postica in 3 days. The number of established nematode was significantly different depending on nematode species, whereas number of progeny was not significantly different. The mean number of established ijs of SgD strain in a host was the highest at 80 ijs by 30.2. The highest progeny number of HeG strain was 2,671.5 with 80 ijs. All nematode strains were not parasitic entirely to H. postica adults. These results show that alfalfa weevil late larva is highly susceptible to Korean entomopathogenic nematodes in the laboratory.

이 연구에서는 원자력발전소 주변 환경 방사선이 생태에 미치는 영향을 감시할 수 있는 생물학적 지표로서 야생 등줄쥐의 활용 가능성을 평가하였다. 국내 5지 역을 선정하여 10월에 한정하여 등줄쥐를 채집하였는데, 농경지에서 산중턱에 이르기까지 폭 넓게 서식하였다. 채집한 쥐들에 대하여 황갈색 피모와 검은색 등줄무늬를 관찰하였는데, 외부형태 특성 가운데 몸통의 길이, 꼬리의 길, 귀의 길이를 계측한 결과, 등줄쥐의 분류기준과 일치하였다. 아울러, 간장내 효소형을 분석한 결과 국내에 서식하는 대부분의 등줄쥐가 Apodemus agrarius라는 것을 알 수 있었다. 또한, 야외에서 생포한 등줄쥐를 암수 한 마리씩 동거시키고 생산된 새끼가 5주령에 도달하였을때 방사선을 조사하고, ICR 마우스를 비교로 생존율과 적혈구내 미소핵 출현빈도를 분석한 결과, 반치사 선량은 5와 7.9Gy였다. 이 연구결과로 야생 등줄쥐가 원자력 발전소 주변 수준의 방사선이 인간생환에 미치는 영향을 판단할 수 있는 생물학적 인 지표로서 잠재적 활용성이 높다는 것을 알 수 있었다.