• Title/Summary/Keyword: Unknown virus

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Wisteria Vein Mosaic Virus Detected for the First Time in Iran from an Unknown Host by Analysis of Aphid Vectors

  • Valouzi, Hajar;Hashemi, Seyedeh-Shahrzad;Wylie, Stephen J.;Ahadiyat, Ali;Golnaraghi, Alireza
    • The Plant Pathology Journal
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    • v.36 no.1
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    • pp.87-97
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    • 2020
  • The development of reverse transcription-polymerase chain reaction using degenerate primers against conserved regions of most potyviral genomes enabled sampling of the potyvirome. However, these assays usually involve sampling potential host plants, but identifying infected plants when they are asymptomatic is challenging, and many plants, especially wild ones, contain inhibitors to DNA amplification. We used an alternative approach which utilized aphid vectors and indicator plants to identify potyviruses capable of infecting common bean (Phaseolus vulgaris). Aphids were collected from a range of asymptomatic leguminous weeds and trees in Iran, and transferred to bean seedlings under controlled conditions. Bean plants were tested serologically for potyvirus infections four-weeks postinoculation. The serological assay and symptomatology together indicated the presence of one potyvirus, and symptomology alone implied the presence of an unidentified virus. The partial genome of the potyvirus, encompassing the complete coat protein gene, was amplified using generic potyvirus primers. Sequence analysis of the amplicon confirmed the presence of an isolate of Wisteria vein mosaic virus (WVMV), a virus species not previously identified from Western Asia. Phylogenetic analyses of available WVMV sequences categorized them into five groups: East Asian-1 to 3, North American and World. The Iranian isolate clustered with those in the World group. Multiple sequence alignment indicated the presence of some genogroup-specific amino acid substitutions among the isolates studied. Chinese isolates were sister groups of other isolates and showed higher nucleotide distances as compared with the others, suggesting a possible Eastern-Asian origin of WVMV, the main region where Wisteria might have originated.

Buffer Overflow Malicious Code Detection by Tracing Executable Area of Memory (메모리 실행영력 추적을 사용한 버퍼오버플로 악성코드 탐지기법)

  • Choi, Sung-Woon;Cho, Jae-Ik;Moon, Jong-Sub
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.19 no.5
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    • pp.189-194
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    • 2009
  • Most of anti-virus programs detect and compare the signature of the malicious code to detect buffer overflow malicious code. Therefore most of anti-virus programs can't detect new or unknown malicious code. This paper introduces a new way to detect malicious code traces memory executable of essentials APIs by malicious code. To prove the usefulness of the technology, 7 sample codes were chosen for compared with other methods of 8 anti-virus programs. Through the simulation, It turns out that other anti-virus programs could detect only a limited portion of the code, because they were implemented just for detecting not heap areas but stack areas. But in other hand, I was able to confirm that the proposed technology is capable to detect the malicious code.

An Analysis Technique for Encrypted Unknown Malicious Scripts (알려지지 않은 악성 암호화 스크립트에 대한 분석 기법)

  • Lee, Seong-Uck;Hong, Man-Pyo
    • Journal of KIISE:Information Networking
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    • v.29 no.5
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    • pp.473-481
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    • 2002
  • Decryption of encrypted malicious scripts is essential in order to analyze the scripts and to determine whether they are malicious. An effective decryption technique is one that is designed to consider the characteristics of the script languages rather than the specific encryption patterns. However, currently X-raying and emulation are not the proper techniques for the script because they were designed to decrypt binary malicious codes. In addition to that, heuristic techniques are unable to decrypt unknown script codes that use unknown encryption techniques. In this paper, we propose a new technique that will be able to decrypt malicious scripts based on analytical approach. we describe its implementation.

Epidemiological characteristics of 2002 outbreak of classical swine fever in Korea (2002년 한국에서 발생한 돼지콜레라의 역학적 특성)

  • Park, Choi-Kyu;Song, Jae-Young;Wee, Sung-Hwan;Lee, Eune-Sub;Yoon, Hachung;Moon, Oun-Kyeong;Choi, Eun-Jin;Nam, Hyang-Mi
    • Korean Journal of Veterinary Research
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    • v.46 no.2
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    • pp.107-117
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    • 2006
  • This paper described the epidemiological characteristics of 2002 outbreak of classical swine fever (CSF) in Korea. A total of thirteen CSF-infected farms could be classified into two clusters according to the location and time of outbreak. Two farms located in the same county of Gangwon province and 11 farms located in several different districts of Incheon metropolitan/Gyeonggi province were identified as CSF-infected from April 16 to 30 and from October 7 to December 21 in 2002, respectively. As the result of epidemiological analysis, the two clusters of outbreaks were turned out to be independent epidemics which had different sources of virus introduction. Three farms were found to have been infected primarily; one located in Cheolwon county of Gangwon province and two located in Kangwha county of Incheon metropolitan area. The most likely factors of virus introduction into these primary infected farms were considered to be direct or indirect contact by foreign workers and/or owners of the infected farms who had come back from traveling in China before outbreaks. This was supported by the genetic typing of CSF viruses isolated from the pigs of infected farms. All the virus isolates of 2002 outbreak were found to be genetic type 2, whereas the viruses isolated before 2000 were type 3 and the reference strains, such as attenuated live vaccine virus (LOM strain) and high virulent challenge virus (ALD strain), were type 1. Accordingly, we concluded that the 2002 CSF outbreak must have been caused by a newly introduced virus from overseas and the type 3 virus must have been eradicated after the last outbreak of 1999 by the national CSF eradication campaign which were implemented since 1996. Based on the combined analysis of epidemiological data and genetic typing, the transmission routes of classical swine fever virus were found to be the movement of vehicles (60%) and persons (10%), neighbourhood spread (20%) and unknown (10%). It is expected that the analyzed data and findings of classical swine fever outbreak epidemic could be very useful to establish the disease control and eradication program for the country in the future.

MALIGNANT LYMPHOMA IN SYSTEMIC LUPUS ERYTHEMATOSUS PATIENT (전신성 홍반성 루푸스 환자에서의 악성임파종 치험례)

  • Woo, Soon-Seop;Kang, Hag-Soo;Lee, Young-Soo;Shim, Kwang-Sup;Yoo, Kwang-Hee
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.20 no.2
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    • pp.97-100
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    • 1998
  • Systemic lupus erythematosus is a severe cutaneous-systemic disorder of unknown etiology, It is represented with erythematous patches on the face in a so-called butterfly distribution, and characteristically classified as an autoimmune disease with antinuclear antibodies. The autoimmune diseases such as systemic lupus erythematosus, $Sj{\ddot{o}}gren$ syndrome, rheumatoid arthritis have been associated with lymphoid malignancy - leukemia, malignant lymphoma - which could involve various organs(spleen, liver, brain, mediastinal lymph node, supraclavicular lymph node, inguinal lymph node, cervical lymph node etc.). Many authors have studied about the association of systemic lupus erythematosus and malignant lymphoma, but exact etiology is still unknown. A common viral etioloty for systemic lupus erythematosus has been suggested since virus-like particles have been found in the glomerular endothelium of patients with systemic lupus erythematosus. These oncogenic viruses may be responsible for the higher frequency of malignant lymphoma in patients with systemic lupus erythematosus. In the other theory, the causes of malignant lymphoma are the defect of immune system due to systemic lupus erythematosus and the long-term use of therapeutics for treatment of systemic lupus erythematosus. When the cellular immune system(delayed hypersensitivity) is impaired by immunosuppressive drugs, it is likely that the body is no longer able to recognize and reject malignant cells as they arise; they continue to grow and divide unhindered. The impairment of the cellular immune system may allow growth of oncogenic virus or the survival of neoplatic tissues. 47-year old female patient treated systemic lupus erythematosus with steroid and immunosuppressive drugs for 5 years visited to our hospital due to elevated mass on left upper anterior maxilla area. By performing biopsy, we diagnosed this lesion as malignant lymphoma and referred to oncologist for chemotherapy. So we report a case of malignant lymphoma due to systemic lupus erythematosus with review of literatures.

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Molecular Characterization of Fusarium Graminearum Virus 2 Isolated from Fusarium graminearum Strain 98-8-60

  • Yu, Ji-Suk;Lee, Kyung-Mi;Son, Moon-Il;Kim, Kook-Hyung
    • The Plant Pathology Journal
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    • v.27 no.3
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    • pp.285-290
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    • 2011
  • Fusarium graminearum virus 2 (FgV2) infects Fusarium graminearum strain 98-8-60 and has at least five segments of double-stranded RNAs (dsRNAs), denoted as dsRNA-1 to dsRNA-5. In this study, the genome of FgV2 was sequenced and its phylogenetic relationship with other mycoviruses was analyzed. The lengths of FgV2 dsRNAs 1-5 ranged from 2414 to 3580 base pairs (bp). The 5' and 3' untranslated regions (UTRs) are highly conserved, and each dsRNA segment had 78-105 and 84-306 bp of 5' and 3' UTRs, respectively. Each dsRNA segment contained a single open reading frame (ORF). Computer analysis of dsRNA-1 revealed a putative open reading frame (ORF) that shows high sequence identity with an RNA-dependent RNA polymerase (RdRp) containing eight conserved motifs. dsRNAs 2-5 also each contain one putative ORF coding for products of unknown function. The sequences of FgV2 dsRNA-2 and dsRNA-3 have significant sequence identity with Magnaporthe oryzae chrysovirus 1 (MoCV1) dsRNA-3 and -4, respectively. When compared to other dsRNA mycoviruses in a phylogenetic analysis of the putative RdRp protein, FgV2 was found to form a distinct virus clade with Aspergillus mycovirus 1816 and MoCV1 in the family Chrysoviridae.

Characterization of Hibiscus Latent Fort Pierce Virus-Derived siRNAs in Infected Hibiscus rosa-sinensis in China

  • Lan, Han-hong;Lu, Luan-mei
    • The Plant Pathology Journal
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    • v.36 no.6
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    • pp.618-627
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    • 2020
  • Although limited progress have been made about pathogen system of Hibiscus rosa-sinensis and Hibiscus latent Fort Pierce virus (HLFPV), interaction between plant host and pathogen remain largely unknown, which led to deficiency of effective measures to control disease of hibiscus plants caused by HLFPV. In this study, infection of HLFPV in Hibiscus rosa-sinensis was firstly confirmed for the first time by traditional electron microscopy, modern reverse transcription polymerase chain reaction and RNA-seq methods in China (HLFPV-Ch). Sequence properties analyzing suggested that the full-length sequences (6,465 nt) of HLFPV-Ch had a high sequence identity and a similar genomic structure with other tobamoviruses. It includes a 5'-terminal untranslated region (UTR), followed by four open reading frames encoding for a 128.5-kDa replicase, a 186.5-kDa polymerase, a 31-kDa movement protein, 17.6-kDa coat protein, and the last a 3'-terminal UTR. Furthermore, HLFPV-Ch-derived virus-derived siRNAs (vsiRNAs) ant its putative target genes, reported also for the first time, were identified and characterized from disease Hibiscus rosa-sinensis through sRNA-seq and Patmatch server to investigate the interaction in this pathogen systems. HLFPV-Ch-derived vsiRNAs demonstrated several general and specific characteristics. Gene Ontology classification revealed predicted target genes by vsiRNAs are involved in abroad range of cellular component, molecular function and biological processes. Taken together, for first time, our results certified the HLFPV infection in China and provide an insight into interaction between HLFPV and Hibiscus rosa-sinensis.

siRNAs Derived from Cymbidium Mosaic Virus and Odontoglossum Ringspot Virus Down-modulated the Expression Levels of Endogenous Genes in Phalaenopsis equestris

  • Lan, Han-hong;Wang, Cui-mei;Chen, Shuang-shuang;Zheng, Jian-ying
    • The Plant Pathology Journal
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    • v.35 no.5
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    • pp.508-520
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    • 2019
  • Interplay between Cymbidium mosaic virus (CymMV)/Odontoglossum ringspot virus (ORSV) and its host plant Phalaenopsis equestris remain largely unknown, which led to deficiency of effective measures to control disease of P. equestris caused by infecting viruses. In this study, for the first time, we characterized viral small interfering RNAs (vsiRNAs) profiles in P. equestris co-infected with CymMV and ORSV through small RNA sequencing technology. CymMV and ORSV small interfering RNAs (siRNAs) demonstrated several general and specific/new characteristics. vsiRNAs, with A/U bias at the first nucleotide, were predominantly 21-nt long and they were derived predominantly (90%) from viral positive-strand RNA. 21-nt siRNA duplexes with 0-nt overhangs were the most abundant 21-nt duplexes, followed by 2-nt overhangs and then 1-nt overhangs 21-nt duplexes in infected P. equestris. Continuous but heterogeneous distribution and secondary structures prediction implied that vsiRNAs originate predominantly by direct Dicer-like enzymes cleavage of imperfect duplexes in the most folded regions of the positive strand of both viruses RNA molecular. Furthermore, we totally predicted 54 target genes by vsiRNAs with psRNATarget server, including disease/stress response-related genes, RNA interference core components, cytoskeleton-related genes, photosynthesis or energy supply related genes. Gene Ontology classification showed that a majority of the predicted targets were related to cellular components and cellular processes and performed a certain function. All target genes were down-regulated with different degree by vsiRNAs as shown by real-time reverse transcription polymerase chain reaction. Taken together, CymMV and ORSV siRNAs played important roles in interplay with P. equestris by down modulating the expression levels of endogenous genes in host plant.

Elucidation of Bacterial Pneumonia-Causing Pathogens in Patients with Respiratory Viral Infection

  • Jung, Hwa Sik;Kang, Byung Ju;Ra, Seung Won;Seo, Kwang Won;Jegal, Yangjin;Jun, Jae-Bum;Jung, Jiwon;Jeong, Joseph;Jeon, Hee-Jeong;Ahn, Jae-Sung;Lee, Taehoon;Ahn, Jong Joon
    • Tuberculosis and Respiratory Diseases
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    • v.80 no.4
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    • pp.358-367
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    • 2017
  • Background: Bacterial pneumonia occurring after respiratory viral infection is common. However, the predominant bacterial species causing pneumonia secondary to respiratory viral infections other than influenza remain unknown. The purpose of this study was to know whether the pathogens causing post-viral bacterial pneumonia vary according to the type of respiratory virus. Methods: Study subjects were 5,298 patients, who underwent multiplex real-time polymerase chain reaction for simultaneous detection of respiratory viruses, among who visited the emergency department or outpatient clinic with respiratory symptoms at Ulsan University Hospital between April 2013 and March 2016. The patients' medical records were retrospectively reviewed. Results: A total of 251 clinically significant bacteria were identified in 233 patients with post-viral bacterial pneumonia. Mycoplasma pneumoniae was the most frequent bacterium in patients aged <16 years, regardless of the preceding virus type (p=0.630). In patients aged ${\geq}16years$, the isolated bacteria varied according to the preceding virus type. The major results were as follows (p<0.001): pneumonia in patients with influenza virus (type A/B), rhinovirus, and human metapneumovirus infections was caused by similar bacteria, and the findings indicated that Staphylococcus aureus pneumonia was very common in these patients. In contrast, coronavirus, parainfluenza virus, and respiratory syncytial virus infections were associated with pneumonia caused by gram-negative bacteria. Conclusion: The pathogens causing post-viral bacterial pneumonia vary according to the type of preceding respiratory virus. This information could help in selecting empirical antibiotics in patients with post-viral pneumonia.

Eosinophilic Gastrointestinal Disorder Presenting as Intractable Vomiting and Ascites in a Young Girl

  • Kwon, Ji Yoon;Huh, Ji Sun;Je, Bo Kyung;Hong, Kwang Dae;Lee, Jee Hyun
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.20 no.3
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    • pp.198-203
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    • 2017
  • Eosinophilic gastrointestinal disorder (EGID) is a rare disease in children that affects the bowel wall, with eosinophilic infiltration in the absence of any other causes for eosinophilia. The etiology remains unknown, but allergies and immunological imbalance are suspected triggers. We encountered a case of serosal EGID presenting as intractable vomiting and ascites in a 9-year-old girl, after influenza virus infection. Peripheral eosinophilia was not present. The diagnosis was confirmed by biopsy of the bowel wall through laparotomy and endoscopy, and controlled by 2 courses of steroid therapy due to recurring symptoms. Influenza virus infection was assumed to play a role in the onset of EGID through a Th2 response that stimulated eosinophilic infiltration in the GI tract. We therefore report this case along with a literature review.