• Parasites, Hosts and Diseases
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• 제53권1호
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• pp.77-83
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• 2015

Wuchereria bancrofti, Dirofilaria immitis, and Dirofilaria repens are filarial nematodes transmitted by mosquitoes belonging to Culex, Aedes, and Anopheles genera. Screening by vector dissection is a tiresome technique. We aimed to screen filarial parasites in their vectors by single and multiplex PCR and evaluate the usefulness of multiplex PCR as a rapid xenomonitoring and simultaneous differentiation tool, in area where 3 filarial parasites are coexisting. Female mosquitoes were collected from 7 localities in Assiut Governorate, were microscopically identified and divided into pools according to their species and collection site. Detection of W. bancrofti, D. immitis, and D. repens using single PCR was reached followed by multiplex PCR. Usefulness of multiplex PCR was evaluated by testing mosquito pools to know which genera and species are used by filarial parasites as a vector. An overall estimated rate of infection (ERI) in mosquitoes was 0.6%; the highest was Culex spp. (0.47%). W. bancrofti, D. immitis, and D. repens could be simultaneously and differentially detected in infected vectors by using multiplex PCR. Out of 100 mosquito pools, 8 were positive for W. bancrofti (ERI of 0.33%) and 3 pools each were positive for D. immitis and D. repens (ERI 0.12%). The technique showed 100% sensitivity and 98% specificity. El-Nikhila, El-Matiaa villages, and Sahel Seleem district in Assiut Governorate, Egypt are still endemic foci for filarial parasites. Multiplex PCR offers a reliable procedure for molecular xenomonitoring of filariasis within their respective vectors in endemic areas. Therefore, it is recommended for evaluation of mosquito infection after lymphatic filariasis eradication programs.

• BMB Reports
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• 제38권1호
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• pp.41-48
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• 2005

In this study we developed the transposon-mediated shuttle vector 'Hanpvid', which composed of HaNPV (Heliothis armigera nuclear polyhedrosis virus) genomic DNA and a transposon cassette from Bacmid of Bac-to-Bac system. Hanpvid replicates in E. coli in the same way as Bacmid and retains infective function in cotton bollworm cells (Hz-AM1). Using Hanpvid we constructed a recombinant virus, which could infect Hz-AM1 cells and generate recombinant HaNPV (rHa-Bar) containing the barnase gene, a ribonuclease gene from Bacillus amyloliquefaciens. Since the expression vector carrying barnase gene cannot replicate in the absence of barstar, a specific inhibitor of barnase, we constructed a new cotton bollworm cell line (AM1-NB) using the marker rescue method. In AM1-NB barstar was integrated into the cellular chromosome to sustain the replication of rHa-Bar. To screen out recombinant HaNPV for potential use as biopesticide, Hz-AM1 and AM1-NB cell lines were infected with rHa-Bar, respectively. The results obtained indicate that Viral progenies in AM1-NB were 23 and 160 times greater than those in Hz-AM1 48 h and 72 h after infection, respectively. With additional insertion of the polyhedron gene from AcNPV (Autographa californica nuclear polyhedrosis virus) into the Hanpvid genome, rHa-Bar regained the polyhedron phenotype and its pest-killing rate greatly improved. Toxic analysis showed that the lethal dosages ($LD_{50}$) and the lethal time(s) ($LT_{50}$) of rHa-Bar were reduced by 20% and 30%, respectively, compared to wt-HaNPV in the third instar larvae of cotton bollworm. This study shows that in AM1-NB barnase can be effectively produced and used as pest-killing agent for the biological control of cotton pests.

• Parasites, Hosts and Diseases
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• 제58권5호
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• pp.583-587
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• 2020

Blastocystis sp. is a kind of protozoa living in the intestinal tract of human and animals, which will cause intestinal diseases such as diarrhea, abdominal distension and vomiting. This paper was aimed to understand the infection of Blastocystis sp. In golden monkeys and the transmission path in North China. Thirty-seven feces samples from golden monkeys and 116 cockroach samples from Shijiazhuang Zoo were collected from July to October 2019 for PCR analysis of Blastocystis sp. Genetic diversity analysis was further conducted on the samples with positive PCR results. The results showed that the infection rate was 48.7% (18/37) in golden monkeys and 82.8% (96/116) in cockroaches, respectively. The genetic evolution analysis based on small subunit ribosomal RNA demonstrated that three subtypes (ST) of Blastocystis sp. including ST1, ST2, and ST3 existed in the intestinal tract of golden monkeys, while only ST2 was detected in the intestinal tract of cockroaches. This paper may provide supports for the quarantine and control of Blastocystis sp. for the zoo in Northern China.

• Parasites, Hosts and Diseases
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• 제54권3호
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• pp.265-272
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• 2016

Wolbachia is an obligatory intracellular endosymbiotic bacterium, present in over 20% of all insects altering insect reproductive capabilities and in a wide range of filarial worms which is essential for worm survival and reproduction. In Egypt, no available data were found about Wolbachia searching for it in either mosquitoes or filarial worms. Thus, we aimed to identify the possible concurrent presence of Wolbachia within different mosquitoes and filarial parasites, in Assiut Governorate, Egypt using multiplex PCR. Initially, 6 pools were detected positive for Wolbachia by single PCR. The simultaneous detection of Wolbachia and filarial parasites (Wuchereria bancrofti, Dirofilaria immitis, and Dirofilaria repens) by multiplex PCR was spotted in 5 out of 6 pools, with an overall estimated rate of infection (ERI) of 0.24%. Unexpectedly, the highest ERI (0.53%) was for Anopheles pharoensis with related Wolbachia and W. bancrofti, followed by Aedes (0.42%) and Culex (0.26%). We also observed that Wolbachia altered Culex spp. as a primary vector for W. bancrofti to be replaced by Anopheles sp. Wolbachia within filaria-infected mosquitoes in our locality gives a hope to use bacteria as a new control trend simultaneously targeting the vector and filarial parasites.

• 한국식물병리학회지
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• 제14권2호
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• pp.150-156
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• 1998

To develop a model for prediction of turnip mosaic virus(TuMV) disease progress of Chinese cabbage based on weather information and number of TuMV vector aphids trapped in Taegwallyeong alpine area, data were statistically processed together. As the variables influenced on TuMV disease progress, cumulative portion(CPT) above 13$^{\circ}C$ in daily average temperature was the most significant, and solar radiation, duration of sunshine, vector aphids and cumulative temperature above $0^{\circ}C$ were significant. When logistic model and Gompertz model were compared by detemining goodness of fit for TuMV disease progress using CPT as independent variable, regression coefficient was higher in the logistic model than in the Gompertz model. Epidemic parameters, apparent infection rate and initial value of logistic model, were estimated by examining the relationship between disease proportion linearized by logit transformation equation, In(Y/Yf-Y) and CPT. Models able to describe the progression of TuMV disease were formulated in Y=100/(1+128.4 exp(-0.013.CPT.(-1(1/(1+66.7.exp(-0.11.day). Calculated disease progress from the model was in good agreement with investigated actual disease progress showing high significance of the coefficient of determination with 0.710.

• Journal of Microbiology and Biotechnology
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• 제17권2호
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• pp.234-243
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• 2007

Vibrio vulnificus is an opportunistic pathogen that causes septicemia in humans. To identify the genes associated with its pathogenicity, in vivo expression technology (IVET) was used to select genes specifically expressed in a host, yet not significantly in vitro. Random lacZ-fusions in the genome of V vulnificus strain MO6-24/O were constructed using an IVET vector, pSG3, which is a suicide vector containing promoterless-aph and -lacZ as reporter genes. A total of ${\sim}18,000$ resulting library clones were then intraperitoneally injected into BALB/c mice using a colony forming unit (CFU) of $1.6{\times}10^6$. Two hours after infection, kanamycin was administered at $200{mu}g$ per gram of mouse weight. After two selection cycles, 11 genes were eventually isolated, which were expressed only in the host. Among these genes, VV20781 and VV21007 exhibiting a homology to a hemagglutinin gene and tolC, respectively, were selected based on having the highest frequency. When compared to wild-type cells, mutants with lesions in these genes showed no difference in the rate of growth rate, yet a significant decrease in cytotoxicity and the capability to form a biofilm.

• 한국작물학회지
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• 제33권1호
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• pp.74-80
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• 1988

중남부지방 8개도에서 평균 10∼20개 장소에서 1986년과 1987년에 조사한 애멸구 발생상황, 9개 38개 장소에서 조사한 애멸구 제 1세대의 흑조위축병 바이러스 보독충율, 그리고 1987년에 13개 장소에서 조사한 11개 옥수수 품종 및 계통의 흑조위축병 나병율과 나병정도를 요약하면 다음과 같다. 1. 애멸구 발생량은 중부지방에서는 적었으나 남쪽으로 내려올수록 현저히 증가하였다. 애멸구 제 1세대 최성기는 4월 하순∼5월 상순이었고 제2세대 최성기는 6월 중순이었다. 애멸구 발생량은 중부지방에서는 제2세대 발생량이 제1세대와 비슷하거나 적었지만 남부지방에서는 제2세대 발생량이 제1세대보다 현저히 높았다. 2. 애멸구 보독충율은 년도, 지역, 조사방법에 따라 현저히 다르며, 경남북 평야지에서 가장 높았고, 이 지역에서 멀어질수록 보독충율이 낮은 경향이었다. 3. 옥수수 흑조위축병 나병율은 대구에서 가장 높아 품종에 따라 9∼39% 나병되었으며, 홍천, 진부, 청주에서는 병이 발생되지 않았고, 기타 지역에서는 13% 이하이었다.

• Parasites, Hosts and Diseases
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• 제30권4호
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• pp.341-348
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• 1992

1991년 8원부터 1992년 4월에 걸쳐, 쭈쭈가무시병 환자 다발생 지역의 하나인 제주도에서 털진드기류에 관한 연구를 실시하여 다음과 같은 결과를 얻었다. (1) 채집된 들쥐 155마리 중 등줄쥐 (Apedemus agrarirsschejuensis) 가 143마리 (92.3%)로 우점종이었고, 땃쥐 (Crocidura laciura) 11마리 (7.1%)와 멧밭쥐 (Micromys minutus) 1마리 (0.6%)였다. 이들 들쥐에 기생한 12,075개체의 털진드기를 동정한 결과 4속 9종이 확인되었다. 그 중, 사 계절을 통한 우점종은 L. zetum(43.3%)이었다. (2) 털진드기 개체군의 계절별 밀도를 비교하면 교. tetu변은 겨 울(46.2%)과 봄(42.9%)에 주로 출현하였고, L. orientale는 겨울(57.7%)에 피크를 보였다. L. scutellare는 가을에 96.0%로 집중적인 발생을 보였고, 가을에 출현하는 모든 털진드기의 79.8%를 차지하여 가을의 우점종으로 쭈쭈가무시병 환자 발생시기와 일치하였다. (3) 총 1,476 개체의 털진드기 유충을 해부하여 그 내용물을 간 접면역형광현미경법으로 관찰한 결과 1,142 개체의 L. scutellare 중 6 마리가 항원 양성으로 확인되어 (감염률 0.5%), 우리 나라에서는 처음으로 L. scutellare도 매 개종임이 밝혀졌다. (4) 채집된 139마리의 등줄쥐 가운데 44마리가 R. tsutsugamushi에 대한 함체 양성으로 나타나 양성률은 31.2%이었다. 사계절을 통한 양성률의 큰 차이는 보이지 않았다.

• 한국잠사곤충학회지
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• 제13권1호
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• pp.17-22
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• 1971

1968년부터 1970년까지 뽕나무위축병에 관하여 접목전염 및 곤충매개전염시험을 한바 결과를 요약하면 다음과 같다. 1. 병근에 건전수목을 절접하므로서 활착주수중 30%의 전염율을 나타냈다. 건전근에 병수목을 절접함에 있어서는 병수목을 월동전에 채취 저장하였다가 익춘 공시한 것은 활착주수중 14%가 전염되였는데 반하여 월동후에 채취한 병수목에 있어서는 전혀 발병되지 않았다. 건전대목에 병수목을 절접하여 불활착된 것 중 대아가 발조한 것은 전혀 발병되지 않았다. 2. 뽕나무위축병의 무병지대에서 채집한 마름무늬매 미충을 중증위축병주에서 7일, 14일, 21일 간식 각각흡즙시킨 성충을 무병실생묘에 방사접종한 결과 7일구는 전염되지 않았으며 14일구는 22％, 21일구는 61％ 전염율을 나타냈다. 흡즙시간과 접종시간은 길수록 전염율이 높았다.

• 대한바이러스학회지
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• 제28권1호
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• pp.1-9
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• 1998

To study the relation between ectoparasite, Rickettsia and hanntan virus in bats, four order of Athropoda were collected from Rhinolophus ferrumequinum captured in Cheju and Eptesicus serotinus captured in Chungnamin from July 1989 to March 1998. Also antibody of Rickettsia and hanntan virus were detected by immunofluoroscent antibody technique and RT-PCR. The results are as follows. 1. Five species of Acarina were identified from E. serotinus: Leptotrobidium subakamushi of Trombiculidae, Macronyssus coreanus, Steatonyssuss spinosuss and Steatonychus superans of Macronyssidae, Argas vespertilionis of Metastigmata. 2. Ischnopsyllus needhami of Siphonaptera and Cimex of Hemiptera were identified from E. serotinus. 3. Cycteribia uenoi and Brachytarsina kanoi of Diptera were identified from R. ferrumequinum. 4. The positive rate of rickettsial antibodies in E. serotinus were 17.58%, 15.15%, 22.22%, 52.73% against R. tsutsugamushi, R. typhi, R. sibirica and R. thai tick typhus, respectively. The high positive rate of antibody related to the high content of Arthropoda. 5. The Positive rate of hantaan virus IFA antibodies were 3.4% (27 of 802) and hanntan virus infection rate 36.7% (22 of 60) by RT-PCR in bats. According these result, we showed that certain species of Athropoda isolated playa role as vector of Rickettsia in E. serotinus. Also bats playa role as a reservoir of hantaan virus in nature.