Molecular characterization of Sunflower chlorotic mottle virus: a member of a distinct species in the genus Potyvirus

The complete nucleotide (nt) and deduced amino acid (aa) sequences of the C (common) and CRS (chlorotic ringspot) Argentine strains of SuCMoV have been determined. The SuCMoV-C RNA genome consists of 9,965 nt, whereas indels within the P1 coding region of SuCMoV-CRS make its genomic length 15 nt shorter. Nucleotide and aa sequence identities between the polyproteins of the C and CRS strains of SuCMoV were 92.3 and 95.6%, respectively. Pairwise comparisons between the polyproteins of the C and CRS strains of SuCMoV and the viruses of the Potato virus Y (PVY) subgroup revealed identities of 66.5–66.9% at the nt level and 69.7–69.8% at the aa level. These results and phylogenetic analyses show that although SuCMoV strains cluster together with the potyviruses belonging to the PVY subgroup, SuCMoV should be considered a member of a distinct species in the genus Potyvirus.     

Characterization of a new potyvirus infecting pepper crops in Ecuador

Sequencing 2,951 nucleotides of the 3' proximal region of the genome of a potyvirus isolate collected from Capsicum pubescens (rocoto) pepper in Ecuador revealed that this was the first representative of a new species tentatively named Ecuadorian rocoto virus (ERV). Phylogeny reconstruction showed that this isolate clustered with potato virus V (PVV), Peru tomato virus and wild potato mosaic virus into a monophyletic group, and was closest to PVV. The isolate was shown to be infectious in tobacco, tomato and, contrary to PVV, in pepper. The pvr2(1), pvr2(2), and Pvr4 genes present in many pepper cultivars conferred resistance toward this isolate and could help control ERV.     

Biological and molecular characterisation of Bidens mosaic virus supports its assignment as a member of a distinct species in the genus Potyvirus

The complete nucleotide (nt) sequence of Bidens mosaic virus (BiMV) isolate SP01 was determined and shown to consist of 9,557 nt. Since it shared highest identities in the nt sequence of the whole genome (66–73 %) and in the aa sequence of the polyprotein (60–76 %) with viruses of the potato virus Y subgroup, it was compared with them genetically and biologically. Phylogenetic analysis showed that the closest relative of BiMV is sunflower chlorotic mottle virus, from which it, however, differed significantly in various respects. These results indicate that BiMV should represent a distinct species in the genus Potyvirus.     

The complete nucleotide sequence of a new bipartite begomovirus from Brazil infecting Abutilon

The complete nucleotide sequence of Abutilon mosaic Brazil virus (AbMBV), a new bipartite begomovirus from Bahia, Brazil, is described and analyzed phylogenetically. Its DNA A is most closely related to those of Sida-infecting begomoviruses from Brazil and forms a phylogenetic cluster with pepper- and Euphorbia-infecting begomoviruses from Central America. The DNA B component forms a cluster with different Sida- and okra-infecting begomoviruses from Brazil. Both components are distinct from those of the classical Abutilon mosaic virus originating from the West Indies. AbMBV is transmissible to Nicotiana benthamiana and Malva parviflora by biolistics of rolling-circle amplification products and induces characteristic mosaic and vein-clearing symptoms in M. parviflora.     

Identification and molecular characterization of a new potyvirus infecting Triteleia species

Plants of Triteleia hyacinthina, Triteleia ixioides Starlight, and Triteleia laxa Corina with severe mosaic and yellow vein-banding were found to be infected with a potyvirus. The 3′-terminal region of the virus was amplified by RT-PCR from total RNA using a potyvirus-specific degenerate primer (poty5P: 5′ GGN AAY AAY AGY GGN CAR CC 3′) and an oligo-dTprimer. The sequence generated included the 3′-NIb protein coding region (680 nucleotides), the entire coat protein coding region (840 nucleotides), and 3’-untranslated region (UTR) (253 nucleotides). Amino acid identity of the whole CP between the triteleia virus and potyvirus member ranged from 54% Apium virus Y (ApVY) to 67% Auraujia mosaic virus (ArjMV) and Twisted-stalk chlorotic streak virus (TSCSV) and the core ranged from 59% (ApVY) to 75% (ArjMV). The 3-UTR showed no significant homology with other known potyviruses. Phylogenetic relationships suggest this triteleia virus is a new member of the Potyvirus genus and the name of “Triteleia mosaic virus” (TriMV) is proposed. This is the first report of a potyvirus infecting triteleia.     

Molecular characterization of a member of a new species of grapevine viroid

Archives of Virology -     

Characterization of a new species of adenovirus in falcons

In 1996, a disease outbreak occurred at a captive breeding facility in Idaho, causing anorexia, dehydration, and diarrhea or sudden death in 72 of 110 Northern aplomado falcons (Falco femoralis septentrionalis) from 9 to 35 days of age and in 6 of 102 peregrine falcons (Falco peregrinus) from 14 to 25 days of age. Sixty-two Northern aplomado and six peregrine falcons died. Epidemiologic analyses indicated a point source epizootic, horizontal transmission, and increased relative risk associated with cross-species brooding of eggs. Primary lesions in affected birds were inclusion body hepatitis, splenomegaly, and enteritis. The etiology in all mortalities was determined by molecular analyses to be a new species of adenovirus distantly related to the group I avian viruses, serotypes 1 and 4, Aviadenovirus. In situ hybridization and PCR demonstrated that the virus was epitheliotropic and lymphotropic and that infection was systemic in the majority of animals. Adeno-associated virus was also detected by PCR in most affected falcons, but no other infectious agents or predisposing factors were found in any birds. Subsequent to the 1996 epizootic, a similar disease caused by the same adenovirus was found over a 5-year period in orange-breasted falcons (Falco deiroleucus), teita falcons (Falco fasciinucha), a merlin (Falco columbarius), a Vanuatu peregrine falcon (Falco peregrinus nesiotes), and gyrfalcon x peregrine falcon hybrids (Falco rusticolus/peregrinus) that died in Wyoming, Oklahoma, Minnesota, and California. These findings indicate that this newly recognized adenovirus is widespread in western and midwestern North America and can be a primary pathogen in different falcon species.     

The complete sequence of the genome of Cocksfoot streak virus (CSV), a grass infecting Potyvirus

Summary.  The complete nucleotide sequence of Cocksfoot streak virus (CSV) has been determined. The viral genome comprises 9663 nucleotides, excluding a 3′-terminal poly(A) sequence. The genome of CSV has a 133 nt 5′-non coding and a 260 nt 3′-non coding region. The RNA of CSV encodes a single polyprotein of 3089 amino acid residues and has a deduced genome organization typical for a member of the family Potyviridae. CSV is transmissible by aphids and has a narrow host range in the Gramineae. It was compared to two potyviruses having monocotyledonous hosts (monocot potyviruses) and several potyviruses infecting dicotyledonous plants (dicot potyviruses). CSV is most closely related to other monocot potyviruses like Maize dwarf mosaic virus (MDMV) and Johnson grass mosaic virus (JGMV), but also closely related to the dicot potyviruses. On the other hand, CSV is less related to monocot viruses from the other genera (Rymovirus, Tritimovirus) within the Potyviridae. Specific motifs, described for potyviral polyproteins, are also present in the polyprotein of CSV. Only two motifs in the HC-Pro – motif involved in long distance movement and motif for HC-Pro self-interaction – were different in comparison to most of the dicot potyviruses. Received September 10, 2001; accepted March 4, 2002 Published online May 24, 2002     

Characterization of Leishmania species from Central-West Region of Brazil

Parasitology Research - Leishmaniasis represents a complex of diseases with a broad clinical spectrum and epidemiological diversity. Involving a variety of agents, reservoirs, and vectors,...     

Study of Myxosporea (Myxozoa), infecting worldwide mullets with description of a new species

Existing data on Myxozoa parasites infecting mullets were reviewed. The validity of nine species names was updated. Sixteen species were registered during analysis of original material collected in the Mediterranean, Black, Azov, and Japan Seas in 2004–2005. A new bivalvulid myxozoan parasite, Myxobolus adeli n. sp., was described from the inner organs of the golden grey mullet Liza aurata (Risso, 1810) collected in the Mediterranean (Ebro Delta, Spain), Black Sea (Kerch Strait, Ukraine), and Azov Sea (Genichesk, Ukraine) coastal waters. It is characterized by the presence of elongated, spindle-like cysts 0.5–1.3 mm in size, filled with wide transverse-oval spores about 6.2?×?7.2?×?4.6 μm in size, with two equal polar capsules measuring about 3.0?×?1.8 μm and short polar filament, turned into four coils. The obtained data show that this species differs from all previously described Myxobolus spp. with equal polar capsules. Comparative study of Myxobolus spp. recorded in worldwide mullets indicates a close relationship with M. adeli n. sp. and Myxobolus improvisus Isjumova, 1964 registered in mullets. Probably, the last species includes representatives of some different species, infecting freshwater and marine hosts.     

Molecular characterisation and evolutionary relationships of a potyvirus infecting Crotalaria in Brazil

Summary.  The 3′ terminal genomic region of a potyvirus causing mosaic disease in several Crotalaria species has been cloned and sequenced. Comparisons of the nucleotide and deduced amino acid (aa) sequences of the cloned cDNA with those from other potyviruses show that the Crotalaria-infecting virus (designated Crotalaria mosaic virus; CrMV) is closely related to Cowpea aphid-borne mosaic virus (CABMV). Maximum identity (95.4%) at the coat protein (CP) aa level was observed between CrMV and a Brazilian strain of CABMV. Phylogenetic analyses derived from the sequence alignments of the CP and 3′ untranslated region confirmed the identification of CrMV as a strain of CABMV and the name CABMV-Cr is suggested. Received April 24, 2001 Accepted October 5, 2001     

A distinct tymovirus infecting Cassia hoffmannseggii in Brazil

Leaves of Cassia hoffmannseggii, a wild fabaceous species found in the Atlantic Forest, with a severe mosaic symptom were collected in Pernambuco State, Brazil. By transmission electron microscopy, two types of virus particles were found: the first was recognized as particles of a potyvirus, which was later identified as Cowpea aphid-borne mosaic virus; and the second was isometric and present in high concentration. The observation of vesicles at the periphery of chloroplasts suggested a tymovirus infection, which was confirmed by subsequent assays. A serological assay against several tymovirus antisera resulted in positive reaction of this tymo-like virus with an antiserum of Passion fruit yellow mosaic virus. By means of RT-PCR and using degenerated primers for the conserved region of RNA-dependent RNA polymerase (RdRp) gene of tymoviruses, a specific DNA fragment was amplified and sequenced. Based on this sequence, a specific forward primer was synthesized and successfully used to amplify the 3' terminal genome region, containing the partial RdRp gene and the complete coat protein (CP) sequences. The CP was 188 amino acids (aa) long, and the highest CP aa identity was observed with Kennedya yellow mosaic virus (61 %). Based on the current ICTV demarcation criterion, this isolate was considered as a distinct tymovirus and tentatively named as Cassia yellow mosaic-associated virus.     

Lettuce necrotic leaf curl virus,a new plant virus infecting lettuce and a proposed member of the genus Torradovirus

A new virus was isolated from a lettuce plant grown in an open field in the Netherlands in 2011. This plant was showing conspicuous symptoms that consisted of necrosis and moderate leaf curling. The virus was mechanically transferred to indicator plants, and a total RNA extract of one of these indicator plants was used for next-generation sequencing. Analysis of the sequences that were obtained and further biological studies showed that the virus was related to, but clearly distinct from, viruses belonging to the genus Torradovirus. The name “lettuce necrotic leaf curl virus” (LNLCV) is proposed for this new torradovirus.     

Characterization of different viruses infecting the marine harmful algal bloom species Phaeocystis globosa

Twelve lytic viruses (PgV) infecting the marine unicellular eukaryotic harmful algal bloom species Phaeocystis globosa were isolated from the southern North Sea in 2000-2001 and partially characterized. All PgV isolates shared common phenotypic features with other algal viruses belonging to the family Phycodnaviridae and could be categorized in four different groups. Two main groups (PgV Group I and II) were discriminated based on particle size (150 and 100 nm respectively), genome size (466 and 177 kb) and structural protein composition. The lytic cycle showed a latent period of 10 h for PgV Group I and latent periods of 12 h and 16 h for PgV Group IIA and IIB. Host specificity and temperature sensitivity finally defined a fourth group (PgV Group IIC). Our results imply that viral infection plays an important role not only in P. globosa dynamics but also in the diversity of both host and virus community.     

Soybean chlorotic spot virus, a novel begomovirus infecting soybean in Brazil

A novel soybean-infecting begomovirus from Brazil was identified in Jaíba, in the state of Minas Gerais, and molecularly characterized. By using rolling-circle amplification-based cloning of viral DNAs, three DNA-A variants and a cognate DNA-B were isolated from infected samples. The DNA variants share more than 98 % sequence identity but have less than 89 % identity to other reported begomovirus, the limit for demarcation of new species. In a phylogenetic analysis, both DNA-A and DNA-B clustered with other Brazilian begomoviruses. Infectious cloned DNA-A and DNA-B components induced distinct symptoms in Solanaceae and Fabaceae species by biolistic inoculation. In soybean, the virus induced mild symptoms, i.e., chlorotic spots on the leaves, from which the name soybean chlorotic spot virus (SoCSV) was proposed. The most severe symptoms were displayed by common beans, which exhibited leaf distortion, blistering, interveinal chlorosis, mosaic and golden mosaic. The possibility that SoCSV may become a threat to bean production in Brazil is discussed.     

Characterization of viruses infecting a eukaryotic Chlorella-like green alga

Nineteen plaque-forming viruses of the unicellular, eukaryotic Chlorella-like green alga, strain NC64A, were isolated from various geographic regions in the United States and characterized. Like the previously described virus, PBCV-1, all of the new viruses were large polyhedrons, sensitive to chloroform, and contained large dsDNA genomes of ca. 300 kbp. All of the viral DNAs contained 5-methyldeoxycytidine which varied from 0.1 to 47% of the deoxycytidine. In addition, 10 of the viral DNAs contained N6-methyldeoxyadenosine which varied from 8.1 to 37% of the deoxyadenosine. These viruses, along with 11 previously described viruses which replicate in the same Chlorella host, were grouped into 11 classes based on at least one of the following properties: plaque size, reaction with PBCV-1 antiserum, or the nature and abundance of methylated bases in their genomic DNA.     

Characterization of hydrangea chlorotic mottle virus, a new member of the genus Carlavirus

An isolate of the tentative carlavirus species Hydrangea chlorotic mottle virus (HdCMV) was found in New Zealand (NZ) in 2007. The host range, serological properties and complete genome sequence of this isolate were determined in this study. While the NZ isolate shared 98% nucleotide sequence identity with the US isolate of HdCMV, differences in titre and host range were found. The HdCMV-NZ genome sequence of 8,433 nt possessed a typical carlavirus organisation with six open reading frames. HdCMV is most closely related (60.4% nt identity) to blueberry scorch virus, a relationship also suggested by serology. These data suggest that HdCMV is a new carlavirus species.     

A novel monopartite begomovirus infecting sweet potato in Brazil

The complete genome sequences of two monopartite begomovirus isolates (genus Begomovirus, family Geminiviridae) present in a single sweet potato (Ipomoea batatas) plant collected in S?o Paulo, Brazil, are presented. Based on the current taxonomic criteria for the genus Begomovirus, one of the isolates was shown to represent a novel species, tentatively named Sweet potato leaf curl Sao Paulo virus (SPLCSPV). The other isolate represented a new strain of sweet potato leaf curl virus, named sweet potato leaf curl virus-Sao Paulo (SPLCV-SP). The full genome sequence of the SPLCSPV isolate shared the highest nucleotide identity (87.6%) with isolates of sweet potato leaf curl Spain virus (SPLCESV). Phylogenetic and recombination analyses were used to investigate the relationships of these isolates to other monopartite Ipomoea-infecting begomoviruses.