scholarly journals Isolation, Pure Culture, and Characterization of “Candidatus Arsenophonus arthropodicus,” an Intracellular Secondary Endosymbiont from the Hippoboscid Louse Fly Pseudolynchia canariensis

2006 ◽  
Vol 72 (4) ◽  
pp. 2997-3004 ◽  
Author(s):  
Colin Dale ◽  
Michael Beeton ◽  
Christopher Harbison ◽  
Tait Jones ◽  
Mauricio Pontes
Keyword(s):  
Pure Culture ◽  
Phylogenetic Analyses ◽  
Insect Cell Line ◽  
Broad Host Range ◽  
Broad Host Range Plasmid ◽  
Pseudolynchia Canariensis ◽  
Bacterial Endosymbionts ◽  
Secondary Endosymbiont

ABSTRACT Members of the genus Arsenophonus comprise a large group of bacterial endosymbionts that are widely distributed in arthropods of medical, veterinary, and agricultural importance. At present, little is known about the role of these bacteria in arthropods, because few representatives have been isolated and cultured in the laboratory. In the current study, we describe the isolation and pure culture of an Arsenophonus endosymbiont from the hippoboscid louse fly Pseudolynchia canariensis. We propose provisional nomenclature for this bacterium in the genus Arsenophonus as “Candidatus Arsenophonus arthropodicus.” Phylogenetic analyses indicate that “Candidatus Arsenophonus arthropodicus” is closely related to the Arsenophonus endosymbionts found in psyllids, whiteflies, aphids, and mealybugs. The pure culture of this endosymbiont offers new opportunities to examine the role of Arsenophonus in insects. To this end, we describe methods for the culture of “Candidatus Arsenophonus arthropodicus” in an insect cell line and the transformation of this bacterium with a broad-host-range plasmid.

scholarly journals African Basil (Ocimum gratissimum) Is a Reservoir of Divergent Begomoviruses in Uganda

Plant Disease ◽  
2020 ◽  
Vol 104 (3) ◽  
pp. 853-859
Author(s):  
Happyness G. Mollel ◽  
Joseph Ndunguru ◽  
Peter Sseruwagi ◽  
Titus Alicai ◽  
John Colvin ◽  
...  
Keyword(s):  
Mosaic Virus ◽  
Phylogenetic Analyses ◽  
Plant Viruses ◽  
Wild Plants ◽  
Bipartite Begomoviruses ◽  
Ocimum Gratissimum ◽  
Genomic Characterization ◽  
Open Access Article

Begomoviruses are plant viruses that cause major losses to many economically important crops. Although they are poorly understood, begomoviruses infecting wild plants may have an important role as reservoirs in the epidemiology of viral diseases. This study reports the discovery and genomic characterization of three novel bipartite begomoviruses from wild and cultivated African basil (Ocimum gratissimum) plants collected in Uganda, East Africa. Based on the symptoms shown by the infected plants, the names proposed for these viruses are Ocimum yellow vein virus (OcYVV), Ocimum mosaic virus (OcMV), and Ocimum golden mosaic virus (OcGMV). Genome and phylogenetic analyses suggest that DNA-A of OcGMV is mostly related to begomoviruses infecting tomato in Africa, whereas those of OcYVV and OcMV are closely related to one another and highly divergent within the Old World begomoviruses. The DNA-A of all characterized begomovirus isolates are of a recombinant nature, revealing the role of recombination in the evolution of these begomoviruses. The viruses characterized here are the first identified in O. gratissimum and the first in Ocimum spp. in the African continent and could have important epidemiological consequences for cultivated basils and other important crops. [Formula: see text] Copyright © 2020 The Author(s). This is an open access article distributed under the CC BY 4.0 International license .

scholarly journals Origin and Evolution of Studiervirinae Bacteriophages Infecting Pectobacterium: Horizontal Transfer Assists Adaptation to New Niches

2020 ◽  
Vol 8 (11) ◽  
pp. 1707
Author(s):  
Peter V. Evseev ◽  
Anna A. Lukianova ◽  
Mikhail M. Shneider ◽  
Aleksei A. Korzhenkov ◽  
Eugenia N. Bugaeva ◽  
...  
Keyword(s):  
New Genus ◽  
Soft Rot ◽  
Broad Host Range ◽  
Gene Exchange ◽  
Genomic Features ◽  
Origin And Evolution ◽  
Phage T7 ◽  
Tail Spike

Black leg and soft rot are devastating diseases causing up to 50% loss of potential potato yield. The search for, and characterization of, bacterial viruses (bacteriophages) suitable for the control of these diseases is currently a sought-after task for agricultural microbiology. Isolated lytic Pectobacterium bacteriophages Q19, PP47 and PP81 possess a similar broad host range but differ in their genomic properties. The genomic features of characterized phages have been described and compared to other Studiervirinae bacteriophages. Thorough phylogenetic analysis has clarified the taxonomy of the phages and their positioning relative to other genera of the Autographiviridae family. Pectobacterium phage Q19 seems to represent a new genus not described previously. The genomes of the phages are generally similar to the genome of phage T7 of the Teseptimavirus genus but possess a number of specific features. Examination of the structure of the genes and proteins of the phages, including the tail spike protein, underlines the important role of horizontal gene exchange in the evolution of these phages, assisting their adaptation to Pectobacterium hosts. The results provide the basis for the development of bacteriophage-based biocontrol of potato soft rot as an alternative to the use of antibiotics.

scholarly journals A27 Whole genome characterization of influenza D viruses detected in cattle herds in northern Italy between 2015 and 2017

2019 ◽  
Vol 5 (Supplement_1) ◽  
Author(s):  
A Bianco ◽  
L Cavicchio ◽  
A Fusaro ◽  
G Rizzo ◽  
A Milani ◽  
...  
Keyword(s):  
Host Range ◽  
Phylogenetic Analyses ◽  
Illumina Miseq ◽  
Northern Italy ◽  
Influenza Viruses ◽  
Broad Host Range ◽  
Human Influenza ◽  
Cattle Herds ◽  
Pcr Targeting

Abstract Influenza D virus (IDV) is a new viral genus identified within the Orthomyxoviridae family, showing 50 per cent amino acid identity with human influenza C virus. Similar to human influenza viruses of the C genus, IDV also harbors 7 genomic segments and uses 9-O-acetylated sialic acids as cell receptors. This newly emerged virus exhibits a broad host range and is capable of infecting swine, cattle, sheep, goats, ferrets, and guinea pigs. In Italy, IDV was first detected in archived samples collected between 2014 and 2015 from cattle and swine in the Po Valley area. Here, we report the genetic characterization of IDV viruses detected in an extensive area of northern Italy, namely Veneto, Lombardy, and Piedmont, through passive surveillance between September 2015 and October 2017. A total of 482 samples, including nasal swabs, lungs, and bronchoalveolar lavage fluid, collected from 309 cattle farms were tested. Thirty cattle herds turned out to be positive, for a total of 40 samples positive by Real Time RT-PCR targeting the PB2 gene. Representative IDV positive swabs were sequenced on an Illumina Miseq platform, and phylogenetic analyses were performed for each genome segment. The analyses of the seven gene segments demonstrated that the viruses identified in the north of Italy clearly grouped within a genetic cluster of IDV sequences previously described in Italy and in the USA, thus suggesting a common origin for these viruses. Interestingly, the IDVs identified in Italy presented a low similarity (96.1% to 98.8% for the seven gene segments) to the French IDVs, which is the only other European country where this pathogen has been identified and characterized so far. The wide IDV host range and the ability of this virus to reassort are a matter of concern. Results of this study indicate that IDV is extensively circulating among bovine herds in Northern Italy and suggest a potential role of IDV in the bovine respiratory disease complex, highlighting the need to perform surveillance on an ongoing basis to track its spread and evolution.

scholarly journals Role of the parCBA Operon of the Broad-Host-Range Plasmid RK2 in Stable Plasmid Maintenance

1998 ◽  
Vol 180 (22) ◽  
pp. 6023-6030 ◽  
Author(s):  
Carla L. Easter ◽  
Helmut Schwab ◽  
Donald R. Helinski
Keyword(s):  
Host Range ◽  
Plasmid Stability ◽  
Broad Host Range ◽  
E Coli ◽  
Broad Host Range Plasmid ◽  
Resolution System ◽  
Stable Maintenance ◽  
Plasmid Stabilization ◽  
Plasmid Rk2

ABSTRACT The par region of the stably maintained broad-host-range plasmid RK2 is organized as two divergent operons,parCBA and parDE, and a cis-acting site. parDE encodes a postsegregational killing system, andparCBA encodes a resolvase (ParA), a nuclease (ParB), and a protein of unknown function (ParC). The present study was undertaken to further delineate the role of the parCBA region in the stable maintenance of RK2 by first introducing precise deletions in the three genes and then assessing the abilities of the different constructs to stabilize RK2 in three strains of Escherichia coli and two strains of Pseudomonas aeruginosa. The intact parCBA operon was effective in stabilizing a conjugation-defective RK2 derivative in E. coli MC1061K and RR1 but was relatively ineffective in E. coli MV10Δlac. In the two strains in which the parCBA operon was effective, deletions in parB, parC, or bothparB and parC caused an approximately twofold reduction in the stabilizing ability of the operon, while a deletion in the parA gene resulted in a much greater loss ofparCBA activity. For P. aeruginosaPAO1161Rifr, the parCBA operon provided little if any plasmid stability, but for P. aeruginosaPAC452Rifr, the RK2 plasmid was stabilized to a substantial extent by parCBA. With this latter strain, parAand res alone were sufficient for stabilization. Thecer resolvase system of plasmid ColE1 and theloxP/Cre system of plasmid P1 were tested in comparison with the parCBA operon. We found that, not unlike what was previously observed with MC1061K, cer failed to stabilize the RK2 plasmid with par deletions in strain MV10Δlac, but this multimer resolution system was effective in stabilizing the plasmid in strain RR1. The loxP/Cre system, on the other hand, was very effective in stabilizing the plasmid in all threeE. coli strains. These observations indicate that theparA gene, along with its res site, exhibits a significant level of plasmid stabilization in the absence of theparC and parB genes but that in at least oneE. coli strain, all three genes are required for maximum stabilization. It cannot be determined from these results whether or not the stabilization effects seen with parCBA or thecer and loxP/Cre systems are strictly due to a reduction in the level of RK2 dimers and an increase in the number of plasmid monomer units or if these systems play a role in a more complex process of plasmid stabilization that requires as an essential step the resolution of plasmid dimers.

scholarly journals Molecular analysis and characterization of a broad-host-range plasmid, pEP2.

1994 ◽  
Vol 176 (18) ◽  
pp. 5718-5728 ◽  
Author(s):  
Y Zhang ◽  
J Praszkier ◽  
A Hodgson ◽  
A J Pittard
Keyword(s):  
Host Range ◽  
Molecular Analysis ◽  
Broad Host Range ◽  
Broad Host Range Plasmid
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