• Parasites, Hosts and Diseases
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• 제60권6호
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• pp.393-400
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• 2022

Human infection with simian malaria Plasmodium knowlesi is a cause for concern in Southeast Asian countries, especially in Malaysia. A previous study on Peninsular Malaysia P. knowlesi rhoptry associated protein-1 (PkRAP1) gene has discovered the existence of dimorphism. In this study, genetic analysis of PkRAP1 in a larger number of P. knowlesi samples from Malaysian Borneo was conducted. The PkRAP1 of these P. knowlesi isolates was PCR-amplified and sequenced. The newly obtained PkRAP1 gene sequences (n=34) were combined with those from the previous study (n=26) and analysed for polymorphism and natural selection. Sequence analysis revealed a higher genetic diversity of PkRAP1 compared to the previous study. Exon II of the gene had higher diversity (π=0.0172) than exon I (π=0.0128). The diversity of the total coding region (π=0.0167) was much higher than those of RAP1 orthologues such as PfRAP-1 (π=0.0041) and PvRAP1 (π=0.00088). Z-test results indicated that the gene was under purifying selection. Phylogenetic tree and haplotype network showed distinct clustering of Peninsular Malaysia and Malaysian Borneo PkRAP1 haplotypes. This geographical-based clustering of PkRAP1 haplotypes provides further evidence of the dimorphism of the gene and possible existence of 2 distinct P. knowlesi lineages in Malaysia.

• IMMUNE NETWORK
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• 제22권3호
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• pp.23.1-23.12
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• 2022

Natural infection with severe acute respiratory syndrome-coronavirus-2 or vaccination induces virus-specific immunity protecting hosts from infection and severe disease. While the infection-preventing immunity gradually declines, the severity-reducing immunity is relatively well preserved. Here, based on the different longevity of these distinct immunities, we develop a mathematical model to estimate courses of endemic transition of coronavirus disease 2019 (COVID-19). Our analysis demonstrates that high viral transmission unexpectedly reduces the rates of progression to severe COVID-19 during the course of endemic transition despite increased numbers of infection cases. Our study also shows that high viral transmission amongst populations with high vaccination coverages paradoxically accelerates the endemic transition of COVID-19 with reduced numbers of severe cases. These results provide critical insights for driving public health policies in the era of 'living with COVID-19.'

• Parasites, Hosts and Diseases
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• 제47권2호
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• pp.189-191
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• 2009

Four feral cats and a raccoon dog purchased from a local collector on Aphaedo Island, Shinan-gun, where human Gymnophalloides seoi infections are known to be prevalent, were examined for their intestinal helminth parasites. From 2 of 4 cats, a total of 310 adult G. seoi specimens were recovered, Other helminths detected in cats included Heterophyes nocens (1,527 specimens), Pygidiopsis summa (131), Stictodora fuscata (4), Acanthotrema felis (2), Spirometra erinacei (15), toxocarids (4), and a hookworm (1). A raccoon dog was found to be infected with a species of echinostome (55), hook-worms (7), toxocarids (3), P. summa (3), and S. erinacei (1). No G. seoi was found in the raccoon dog. The results indicate that feral cats and raccoon dogs on Aphaedo are natural definitive hosts for intestinal trematodes and cestodes, including G. seoi, H. nocens, and S. erinacei, It has been first confirmed that cats, a mammalian species other than humans, play the role of a natural definitive host for G. seoi on Aphaedo Island.

• Journal of Ginseng Research
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• 제37권2호
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• pp.210-218
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• 2013

Numerous studies have suggested that Korean red ginseng (KRG) extract has various immune modulatory activities both in vivo and in vitro. In this study, we used a mouse model to examine the effects of orally administered KRG extract on immunity against herpes simplex virus (HSV). Balb/c mice were administered with 100, 200, and 400 mg/kg oral doses of KRG extract for 10 d and then vaginally infected with HSV. We found that KRG extract rendered recipients more resistant against HSV vaginal infection and further systemic infection, including decreased clinical severity, increased survival rate, and accelerated viral clearance. Such results appeared to be mediated by increased vaginal IFN-${\gamma}$ secretion. Moreover, increased mRNA expression of IFN-${\gamma}$, granzyme B, and Fas-ligand was identified in the iliac lymph node and vaginal tracts of KRG extract treated groups (200 and 400 mg/kg). These results suggest that the activities of local natural killer cells were promoted by KRG extract consumption and that KRG may be an attractive immune stimulator for helping hosts overcome HSV infection.

• The Plant Pathology Journal
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• 제37권2호
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• pp.162-172
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• 2021

Soybean mosaic virus (SMV) is the predominant viral pathogen that affects the yield and quality of soybean. The natural host range for SMV is very narrow, and generally limited to Leguminosae. However, we found that SMV can naturally infect Pinellia ternata and Atractylodes macrocephala. In order to clarify the molecular mechanisms underlying the cross-family infection of SMV, we used double-stranded RNA extraction, rapid amplification of cDNA ends polymerase chain reaction and Gibson assembly techniques to carry out SMV full-length genome amplification from susceptible soybeans and constructed an infectious cDNA clone for SMV. The genome of the SMV Shanxi isolate (SMV-SX) consists of 9,587 nt and encodes a polyprotein consisting of 3,067 aa. SMV-SX and SMV-XFQ008 had the highest nucleotide and amino acid sequence identities of 97.03% and 98.50%, respectively. A phylogenetic tree indicated that SMV-SX and SMV-XFQ018 were clustered together, sharing the closest relationship. We then constructed a pSMV-SX infectious cDNA clone by Gibson assembly technology and used this clone to inoculate soybean and Ailanthus altissima; the symptoms of these hosts were similar to those caused by the virus isolated from natural infected plant tissue. This method of construction not only makes up for the time-consuming and laborious defect of traditional methods used to construct infectious cDNA clones, but also avoids the toxicity of the Potyvirus special sequence to Escherichia coli, thus providing a useful cloning strategy for the construction of infectious cDNA clones for other viruses and laying down a foundation for the further investigation of SMV cross-family infection mechanisms.

• 한국잠사곤충학회지
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• 제47권1호
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• pp.18-30
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• 2005

국내 자생 동충하초균의 발생환경과 그 발생빈도를 조사하고 수집된 표본의 형태적 특성에 의해 동정하였다. 국내 산지 19개소에서 1999년부터 2002년까지 수집된 동충하초는 5속 17종이었으며(Cordyceps gracilioides, C. japonica, C. longissima, C. martialis, C. militaris, C. myrmeopila, C. nutans, C. pruinosa, C. sphecocephala, C. tricentri, Hirsutella nutans, Paecilomyces cicadae, P. farinosus, P. tenuipes, paecilomyces sp., Shimizuomyces paradoxa, Tilachidiopsis nigra), 그 외 중국도입 C. sinensis균 특성ㄷ 추가조사하였다. 국내수집 균주는 계곡 및 저습지, 이끼지역, 활엽수림 등에 주고 분포하였으며, 제한된 조사지역과 채집시기에 비하여 다양한 종이 발견되었으나, 종별 채집 수는 10여 점으로서 발생빈도는 대체로 낮았다. 제주도는 내륙과 격리된 남쪽에 위치하므로 비교적 온난하며 한라산은 기후의 수직분포가 커서 종의 분포가 다양하며 특이한 것으로 평가된다. 수집종은 온도가 높고 습기가 많은 8월 초순에 많이 채집되었으며, C. nutans, C. militaris, P. tenuipes의 발생빈도가 현저히 높았고 그 중에서 C. nutans는 667념 중 65%로서 우점종이었다. Cordyceps는 숙주개체 당 1~2개의 자좌를 형성하며, 자낭각 배열과 이차포자 발달에는 종내 변이가 없으나, 자좌의 수, 형태, 색상 드은 발생환경 및 숙주에 따른 변이가 인정되었다.

• 농촌의학ㆍ지역보건
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• 제26권2호
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• pp.181-191
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• 2001

개회충증에 대한 IgG 항체반응을 ELISA를 이용하여 거제도 및 인천 지역 주민의 혈청 역학적 조사를 시행하여 다음과 같은 결과를 얻었다. 개회충증에 대한 혈청 항체 양성률은 거제도 지역 주민은 15.7%를 나타내었다. 성별 양성률을 보면 남자는 7.4%인데 비하여 여자는 23.8%의 높은 양성률을 나타내었으며 통계학적으로 남 녀 성별간에 유의한 차이가 있었다(p<0.05). 연령별 양성률을 비교하면 남 녀 모두 20대에서 각각 14.3%, 39.3%로 가장 높았다. 인천 지역 주민은 13.1%의 양성률을 보였다. 남자는 14.4%, 여자는 12.1%의 양성률을 나타내었으며 성별간의 유의한 차이는 볼 수 없었다. 연령별로는 남자는 전 연령층에서 비슷한 양성률을 나타내었으나 30대에서 17.8%로 가장 높게 나타났으며, 여자는 6.3%-20.0%의 양성률을 나타내었으며 10대에서 가장 높은 양성률을 보였다. 지역간의 통계학적 유의성차이는 전체 및 남자에서는 없었으나 여자에서는 차이가 있었다(p<0.05). ELISA 방법으로 혈청 항체가가 양성으로 나타난 혈청을 immunoblotting한 결과 거제도 지역 15 예 중 9예가 양성으로 나타났으며 인천 지역은 27예 중 22예가 양성반응을 보였다.

• Parasites, Hosts and Diseases
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• 제52권3호
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• pp.281-285
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• 2014

Ticks were collected from 35 animals from 5 provinces and 3 metropolitan cities during 2012. Ticks also were collected by tick drag from 4 sites in Gyeonggi-do (2) and Jeollabuk-do (2) Provinces. A total of 612 ticks belonging to 6 species and 3 genera were collected from mammals and a bird (n=573) and by tick drag (n=39). Haemaphyalis longicornis (n=434) was the most commonly collected tick, followed by H. flava (158), Ixodes nipponensis (11), Amblyomma testudinarium (7), H. japonica (1), and H. formosensis (1). H. longicornis and H. flava were collected from all animal hosts examined. For animal hosts (n>1), the highest Tick Index (TI) was observed for domestic dogs (29.6), followed by Siberian roe deer (17.4), water deer (14.4), and raccoon dogs (1.3). A total of 402 H. longicornis (adults 86, 21.4%; nymphs 160, 39.8%; larvae 156, 38.9%) were collected from wild and domestic animals. A total of 158 H. flava (n=158) were collected from wild and domestic animals and 1 ring-necked pheasant, with a higher proportion of adults (103, 65.2%), while nymphs and larvae only accounted for 12.7% (20) and 22.2% (35), respectively. Only 7 A. testudinarium were collected from the wild boar (6 adults) and Eurasian badger (1 nymph), while only 5 I. nipponensis were collected from the water deer (4 adults) and a raccoon dog (1 adult). One adult female H. formosensis was first collected from vegetation by tick drag from Mara Island, Seogwipo-si, Jeju-do Province.

• The Plant Pathology Journal
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• 제32권3호
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• pp.201-208
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• 2016

The main areas for field-grown vegetable production in Iran were surveyed during the years of 2012-2014 to determine the occurrence of begomoviruses infecting these crops. A total of 787 leaf samples were collected from vegetables and some other host plants showing virus-like symptoms and tested by an enzymelinked immunosorbent assay (ELISA) using polyclonal antibodies produced against Tomato yellow leaf curl virus (TYLCV). According to the ELISA results, 81 samples (10.3%) positively reacted with the virus antibodies. Begomovirus infections were confirmed by polymerase chain reaction (PCR) using previously described TYLCV-specific primer pair TYLCV-Sar/TYLCV-Isr or universal primer pair Begomo-F/Begomo-R. The PCR tests using the primer pair TYLCV-Sar/TYLCV-Isr resulted in the amplification of the expected fragments of ca. 0.67-kb in size for ELISA-positive samples tested from alfalfa, pepper, spinach and tomato plants, confirming the presence of TYLCV. For one melon sample, having a week reaction in ELISA and no reaction in PCR using TYLCV-specific primers, the PCR reaction using the primer pair Begomo-F/Begomo-R resulted in the amplification fragments of the expected size of ca. 2.8 kb. The nucleotide sequences of the DNA amplicons derived from the isolate, Kz-Me198, were determined and compared with other sequences available in GenBank. BLASTN analysis confirmed the begomovirus infection of the sample and showed 99% identities with Tomato leaf curl New Delhi virus (ToLCNDV); phylogenetic analysis supported the results of the database searches. This study reports the natural occurrence of TYLCV in different hosts in Iran. Our results also reveal the emergence of ToLCNDV in Iranian cucurbit crops.

• 한국응용곤충학회지
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• 제50권1호
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• pp.7-14
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• 2011

2000년 삼척 동해안산불이 나방군집에 미친 영향을 조사하였다. 조사는 3개의 조사지(지점1: 미피해지역, 지점2: 지표화 피해지역, 지점3: 수관화 피해지역)를 설정하여 2006부터 2009년 까지 1년에 4회 UV 라이트 트랩으로 실시하였다. 그 결과, 3개의 조사지에서 30과 727종 3,804개체를 채집하였다(지점1: 27과 505종 1,727개체, 지점2: 24과 353종 1,193개체, 지점3: 25과 340종 885개체). 밤나방과, 명나방과, 자나방과와 잎말이나방과는 종수와 개체수가 3개의 조사지에서 상위를 점했다. 종수, 개체수, 종다양도(H') 모두 지점1에서 가장 높았다. 유사도(${\alpha}$-Index)는 2006년에는 지점2와 3이 더 높았지만, 2009년에는 지점1과 2가 더 높았다. 나방류를 유충기의 기주로 16개 카테고리로 나누어 군집변화를 분석하였다. 지점3에서 초본식성의 나방류의 개체수는 지속적으로 감소했지만, 목본식성의 개체수의 비율은 지속적으로 증가했다. 이 연구결과, 나방군집은 산불 이후 식생변화와 더불어 회복되었고 지표화 피해지역에서 나방군집의 재생은 수관화 피해지역보다 빠른 것으로 나타났다.