Citrus leprosis virus C (leprosis of citrus).

Author(s):  
John S. Hartung ◽  
M. Guillermo León

Abstract CiLV-C is a quarantine pest which causes an economically important disease, reported only on the American continent. During the past 15 years, it has caused economic losses in Brazil, Argentina, Paraguay, Uruguay, Venezuela, Costa Rica, Panamá and Honduras. The disease was recently reported in Guatemala, Bolivia, México, Colombia and Belize. It is a threat to citrus-producing countries where the disease has not been reported. The disease can cause 100% yield loss (Rodrigues et al., 2000). CiLV does not appear to move systemically in the host plant but can move short distances from a grafted shoot tip to the adjacent scion tissue. Accordingly, movement in latently infected planting material is not likely to be a major pathway for CiLV-C because of its non-systemic infection, CiLV-C can only be important where attacks by its vector mites are significant. The main means of movement and dispersal of the virus is via the vector mites of the genus Brevipalpus, which colonize most species of Citrus and many other plant species.

2021 ◽  
Author(s):  
John S. Hartung ◽  
M. Guillermo León

Abstract CiLV-C is a quarantine pest which causes an economically important disease, reported only on the American continent. During the past 15 years, it has caused economic losses in Brazil, Argentina, Paraguay, Uruguay, Venezuela, Costa Rica, Panamá and Honduras. The disease was recently reported in Guatemala, Bolivia, México, Colombia and Belize. It is a threat to citrus-producing countries where the disease has not been reported. The disease can cause 100% yield loss (Rodrigues et al., 2000).


2021 ◽  
Vol 12 ◽  
Author(s):  
Camila Chabi-Jesus ◽  
Pedro L. Ramos-González ◽  
Matheus Postclam-Barro ◽  
Rafaela Salgado Fontenele ◽  
Ricardo Harakava ◽  
...  

Despite the importance of viral strains/variants as agents of emerging diseases, genetic and evolutionary processes affecting their ecology are not fully understood. To get insight into this topic, we assessed the population and spatial dynamic parameters of citrus leprosis virus C (CiLV-C, genus Cilevirus, family Kitaviridae). CiLV-C is the etiological agent of citrus leprosis disease, a non-systemic infection considered the main viral disorder affecting citrus orchards in Brazil. Overall, we obtained 18 complete or near-complete viral genomes, 123 complete nucleotide sequences of the open reading frame (ORF) encoding the putative coat protein, and 204 partial nucleotide sequences of the ORF encoding the movement protein, from 430 infected Citrus spp. samples collected between 1932 and 2020. A thorough examination of the collected dataset suggested that the CiLV-C population consists of the major lineages CRD and SJP, unevenly distributed, plus a third one called ASU identified in this work, which is represented by a single isolate found in an herbarium sample collected in Asuncion, Paraguay, in 1937. Viruses from the three lineages share about 85% nucleotide sequence identity and show signs of inter-clade recombination events. Members of the lineage CRD were identified both in commercial and non-commercial citrus orchards. However, those of the lineages SJP were exclusively detected in samples collected in the citrus belt of São Paulo and Minas Gerais, the leading Brazilian citrus production region, after 2015. The most recent common ancestor of viruses of the three lineages dates back to, at least, ∼1500 years ago. Since citrus plants were introduced in the Americas by the Portuguese around the 1520s, the Bayesian phylodynamic analysis suggested that the ancestors of the main CiLV-C lineages likely originated in contact with native vegetation of South America. The intensive expansion of CRD and SJP lineages in Brazil started probably linked to the beginning of the local citrus industry. The high prevalence of CiLV-C in the citrus belt of Brazil likely ensues from the intensive connectivity between orchards, which represents a potential risk toward pathogen saturation across the region.


1962 ◽  
Vol 60 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Margaret D. Beech ◽  
A. E. Duxbury ◽  
Peter Warner

This paper consists of an epidemiological study of 52 cases of Q fever occurring in metropolitan Adelaide in 1957 and also a description of the results of a survey of 516 sera obtained from abattoir workers.The only case occurring outside the abattoirs was a dairy farmer who probably became infected while visiting the abattoirs. If this were so the incubation period (35 days) of his disease would have been exceptionally long.The general features of the outbreak, which lasted several months, differed from those on the North American continent in that the latter occurred explosively within a few days with very high attack rates. The situation in the Adelaide abattoirs is similar to that in Brisbane, where the disease appears to be endemic. However, unlike in Adelaide, cases are commonly recognized outside the abattoirs in Brisbane.In the abattoirs the disease affected mainly inspectors, those working on killing beef, and those working on offal. Mutton workers were not so severely affected. However, all these groups had similar incidences of low titre antibodies suggesting that in the past Q fever spread equally in all killing departments. In departments not directly associated with slaughtering the incidence both of cases in 1957 and low titre antibodies was relatively small.It was suggested that the epidemiological features of Q fever in Adelaide could be explained by the irregular appearance of animals from infected herds situated perhaps in Queensland—a known endemic area. Perhaps the appearance of such animals in the Adelaide abattoirs might be governed by meteorological conditions such that they were prevented from going to the ordinarily most convenient slaughterhouse.


2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Getachew Gari ◽  
Biressaw Serda ◽  
Dejene Negesa ◽  
Fethu Lemma ◽  
Hagos Asgedom

Peste des petits ruminant (PPR) is an economically important disease of small ruminants with a rapidly expanding geographical distribution. There are fragmented reports to the occurrence and distribution of the disease in Ethiopia. A total of 700 serum samples were collected from goats and sheep to detect the presence of antibody against PPR virus using Competitive Enzyme-Linked Immunosorbent Assay (C-ELISA). An overall PPR seropositivity was reported to be 48.43% in the area. There is no statistically significant difference in the seroprevalence of the disease between sheep and goats (50.85% and 46.68%), respectively. However, there was statistically significant variation (P<0.05) in the seroprevalence of the disease in young (33.9%) and adult (55.8%) age categories. The seroprevalence in male and female was 42.07% and 50.09%, respectively, where the variation was statistically not significant (P>0.05). High seroprevalence of Peste des petites ruminants in the study area indicated the virus circulation and endemicity of the disease. The disease causes substantial economic losses by affecting the livelihood of the farmers. Therefore, control measures should be put in place to minimize the loss associated with the disease.


2020 ◽  
Author(s):  
Abel Debebe Mitiku ◽  
Dawit Tesfaye Degefu ◽  
Adane Abraham ◽  
Desta Mejan ◽  
Pauline Asami ◽  
...  

AbstractGarlic is one of the most crucial Allium vegetables used as seasoning of foods. It has a lot of benefits from the medicinal and nutritional point of view; however, its production is highly constrained by both biotic and abiotic challenges. Among these, viral infections are the most prevalent factors affecting crop productivity around the globe. This experiment was conducted on eleven selected garlic accessions and three improved varieties collected from different garlic growing agro-climatic regions of Ethiopia. This study aimed to identify and characterize the isolated garlic virus using the coat protein (CP) gene and further determine their phylogenetic relatedness. RNA was extracted from fresh young leaves, thirteen days old seedlings, which showed yellowing, mosaic, and stunting symptoms. Pairwise molecular diversity for CP nucleotide and amino acid sequences were calculated using MEGA5. Maximum Likelihood tree of CP nucleotide sequence data of Allexivirus and Potyvirus were conducted using PhyML, while a neighbor-joining tree was constructed for the amino acid sequence data using MEGA5. From the result, five garlic viruses were identified viz. Garlic virus C (78.6 %), Garlic virus D (64.3 %), Garlic virus X (78.6 %), Onion yellow dwarf virus (OYDV) (100%), and Leek yellow stripe virus (LYSV) (78.6 %). The study revealed the presence of complex mixtures of viruses with 42.9 % of the samples had co-infected with a species complex of Garlic virus C, Garlic virus D, Garlic virus X, OYDV, and LYSV. Pairwise comparisons of the isolated Potyviruses and Allexiviruses species revealed high identity with that of the known members of their respected species. As an exception, less within species identity was observed among Garlic virus C isolates as compared with that of the known members of the species. Finally, our results highlighted the need for stepping up a working framework to establish virus-free garlic planting material exchange in the country which could result in the reduction of viral gene flow across the country.Author SummaryGarlic viruses are the most devastating disease since garlic is the most vulnerable crop due to their vegetative nature of propagation. Currently, the garlic viruses are the aforementioned production constraint in Ethiopia. However, so far very little is known on the identification, diversity, and dissemination of garlic infecting viruses in the country. Here we explore the prevalence, genetic diversity, and the presence of mixed infection of garlic viruses in Ethiopia using next generation sequencing platform. Analysis of nucleotide and amino acid sequences of coat protein genes from infected samples revealed the association of three species from Allexivirus and two species from Potyvirus in a complex mixture. Ultimately the article concludes there is high time to set up a working framework to establish garlic free planting material exchange platform which could result in a reduction of viral gene flow across the country.


2011 ◽  
Vol 8 (3) ◽  
pp. 694-698
Author(s):  
Baghdad Science Journal

Newcastle Disease is one of the most important disease world wide distributions which invade the flock in different age resulting in large economic losses. This study aimed to evaluate the effect of treatment with 4 different concentrations (0.25, 0.5, 1.0 and 2.0 %) of Sodium deoxycholate (SDC) on the vaccinal virus (La Sota) using inoculation in the fragments of Chorioallantoic membrane. The treatment with each of the above 4 concentrations of SDC resulted in an increase in the Hemagglutination titer (HA) of the virus (28, 29.6, 211.6, 214.6) respectively as compared to the HA titer value for the untreated virus (26.6). No significant differences were noticed among all concentrations with regard to their effect on the HA titer, except the concentrations of 1.0 and 2.0 % where significant differences were recorded (P > 0.05). The results of this study suggest that SDC has an important activity in enhancement of the replication of NDV through increasing the Hemagglutination titer, which has a great importance in vaccine production.


Author(s):  
Fernando Cid Lucas
Keyword(s):  

En el presente artículo se analiza la presencia de americanismos insertos en las letras de algunas de las guajiras flamencas más conocidas en el repertorio pasado y actual del flamenco. Por otra parte, se comentarán algunos errores de pronunciación de dichos vocablos venidos desde el continente americano en los que han caído cantaores y cantaoras flamencos. In this article we will analyze the presence of several Americanisms inserted in the lyrics of some of the best known flamenco guajiras in the past and current repertoire of flamenco. In the same way, some solutions will be given to some errors of pronunciation of those words coming from the American continent made by flamenco singers.


2018 ◽  
Vol 69 (1) ◽  
pp. 711 ◽  
Author(s):  
I. SYMEONIDOU ◽  
E. BONOS ◽  
K. MOUSTAKIDIS ◽  
P. FLOROU-PANERI ◽  
E. CHRISTAKI ◽  
...  

Parasites (protozoa, helminthes, arthropods) represent a main threat for poultry worldwide. Among helminthes, nematodes constitute the most important group of parasites of poultry. The nematode Ascaridia galli, the cause of ascaridiosis in poultry, is one of the most important and prevalent parasites, resulting in serious economic losses, associated with the treatment cost, the decreased feed efficiency, and the poor egg and meat production. During the past few decades the indiscriminate use of anthelmintic drugs has generated several cases of resistance in helminthes in poultry, situation which is coupled with the severity of residues in poultry products. For this reason, nowadays attention has been drawn to the use of botanicals in poultry diet, due to their anthelmintic properties. Furthermore, the dietary use eco-friend ly of these plant derived substances compared to conventional synthetic anthelmintic drugs is considered as a natural and ecofriendly approach by the consumers. The focus of the present review is to recapitulate the studies, both in vivo and in vitro, that have demonstrated the anthelmintic efficacy of various dietary botanicals in controlling poultry ascaridiosis.


2021 ◽  
pp. 3-8
Author(s):  
Ю.А. Шнейдер ◽  
Е.В. Каримова ◽  
Ю.Н. Приходько ◽  
Е.Н. Лозовая ◽  
Т.С. Живаева

Томат – важнейшая овощная культура с ежегодным увеличением объемов его производства во всем мире. В Российской Федерации последние несколько лет активно развиваются предприятия защищенного грунта, специализирующиеся на производстве томатов. Вместе с тем растения томата поражают более 200 различных вредителей и болезней. Возбудители вирусных болезней растений – важный ограничивающий фактор для многих отраслей растениеводства, в том числе овощеводства. В последние годы в европейских странах производство томатов в открытом и защищенном грунте пострадало от серьезных потерь, вызванных, главным образом, вирусными фитопатогенами. В статье представлен обзор трех наиболее опасных вирусов, возбудителей болезней томатов – коричневой морщинистости плодов томата, мозаики пепино, пятнистого увядания томата. Эти вирусы неоднократно были выявлены в целом ряде стран практически на всех континентах и вызвали значительные экономические потери в странах своего распространения. Ввиду очень быстрого распространения и обнаружения опасных вирусов томата в ряде стран, занимающихся производством и дальнейшим экспортом семян и плодов томатов, Федеральная служба по ветеринарному и фитосанитарному надзору Российской Федерации (Россельхознадзор) с 27 июля 2020 года ввела в качестве временной карантинной фитосанитарной меры требование об отсутствии этих вирусов в семенах, посадочном материале и плодах растений-хозяев при их ввозе и перемещении по территории Российской Федерации. Результаты анализов фитосанитарного риска, проведенных в ФГБУ «ВНИИКР» в 2020 году, показали, что вирусы коричневой морщинистости плодов томата, мозаики пепино и пятнистого увядания томата соответствуют критериям карантинных для Российской Федерации организмов, вирусы способны проникнуть на территорию страны с подкарантинной продукцией, распространиться и нанести существенный ущерб развитию сельского хозяйства и экономической деятельности страны. Tomato is the most important vegetable crop with an annual increase in its production worldwide. In the Russian Federation, greenhouse industry specializing in the production of tomatoes have been actively developing over the past few years. At the same time, tomato plants affect more than 200 different pests and diseases. Pathogens of viral diseases of plants are an important limiting factor for many branches of crop production, including vegetable growing. In recent years, in European countries, the production of tomatoes in open field and greenhouses has suffered from serious losses caused mainly by viral phytopathogens. The article presents an overview of the three most dangerous viruses, pathogens of tomato diseases – tomato brown rugose fruit virus (ToBRFV), pepino mosaic virus (PepMV) and tomato spotted wilt virus (TSWV). These viruses have been repeatedly detected in a number of countries on almost all continents and have caused significant economic losses in the countries of their distribution. In view of the very rapid spread and detection of dangerous tomato viruses in a number of countries engaged in the production and further export of tomato seeds and fruits, Rosselkhoznadzor, from July 27, 2020, introduced as a temporary quarantine phytosanitary measure the requirement that these viruses are not present in seeds, planting material and fruits of host plants when they are imported and moved through the territory of the Russian Federation. The results of the phytosanitary risk analyses conducted at the Federal State Budgetary Institution «VNIIKR» in 2020 showed that ToBRFV, PepMV and TSWV meet the criteria of quarantine organisms for the Russian Federation, viruses are able to enter the territory of the country with quarantined products, spread and cause significant damage to the development of agriculture and economic activity of the country.


Author(s):  
G. S. Saddler

Abstract A description is provided for Burkholderia solanacearum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: The host range is one of the widest of all the phytopathogenic bacteria. The most susceptible plant family, in terms of numbers of species affected is the Solanaceae; over fifty other plant families contain susceptible species. The most economically significant hosts are listed here. For a more complete listing see Kelman (1953), Bradbury (1986) and Hayward & Hartman (1994). Arachis hypogaea, Capsicum spp., Gossypium hirsutum, Ipomoea batatus, Lycopersicon esculentum, Manihot esculenta, Musa spp., Nicotiana spp., Solanum melongena, Solanum tuberosum & Zingiber officinale. DISEASE: Bacterial wilt. Infection is systemic, producing a wilt of parts or the whole plant. Vascular system may become discoloured, bacterial ooze can be produced and plants may be stunted and chlorotic. GEOGRAPHICAL DISTRIBUTION: Widespread in tropical, subtropical and warm temperate regions of the world (see data sheets on quarantine pests). TRANSMISSION: A variety of modes of transmission exist which are host dependant. Infected planting material and true seed is responsible for the spread of bacterial wilt of banana, ginger, groundnut, potato and tomato, whilst transport of latently infected in seedlings (stawberry) and the actions of insect (Moko disease of banana) and weather (tobacco) have all been implicated. For a review see Kelman et al. (1994).


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