scholarly journals Pathogenicity of Nectriaceous Fungi on Avocado in Australia

2017 ◽  
Vol 107 (12) ◽  
pp. 1479-1485 ◽  
Author(s):  
Louisamarie E. Parkinson ◽  
Roger G. Shivas ◽  
Elizabeth K. Dann
Keyword(s):  
Host Range ◽  
Root Rot ◽  
Severe Disease ◽  
Persea Americana ◽  
Broad Host Range ◽  
Black Root Rot ◽  
Calonectria Ilicicola ◽  
Leaf Drop ◽  
Custard Apple ◽  
Pathogenicity Tests

Black root rot is a severe disease of young avocado trees in Australia causing black necrotic roots, tree stunting, and leaf drop prior to tree death. Nectriaceous fungi (Nectriaceae, Hypocreales), are commonly isolated from symptomatic roots. This research tested the pathogenicity of 19 isolates from Calonectria, Cylindrocladiella, Dactylonectria, Gliocladiopsis, and Ilyonectria, spp. collected from young avocado trees and other hosts. Glasshouse pathogenicity tests with ‘Reed’ avocado (Persea americana) seedlings confirmed that Calonectria ilicicola is a severe pathogen of avocado, causing stunting, wilting, and seedling death within 5 weeks of inoculation. Isolates of C. ilicicola from peanut, papaya, and custard apple were also shown to be aggressive pathogens of avocado, demonstrating a broad host range. An isolate of a Calonectria sp. from blueberry and avocado isolates of Dactylonectria macrodidyma, D. novozelandica, D. pauciseptata, and D. anthuriicola caused significant root rot but not stunting within 5 to 9 weeks of inoculation. An isolate of an Ilyonectria sp. from grapevine closely related to Ilyonectria liriodendri, and avocado isolates of Cylindrocladiella pseudoinfestans, Gliocladiopsis peggii, and an Ilyonectria sp. were not pathogenic to avocado.

scholarly journals The first genomic resources for Phymatotrichopsis omnivora, a soil-borne pezizomycete pathogen with a broad host range

2021 ◽  
Author(s):  
Chakradhar Mattupalli ◽  
Jason Shiller ◽  
Prasanna Kankanala ◽  
Nick D Krom ◽  
Stephen Marek ◽  
...  
Keyword(s):  
Host Range ◽  
Root Rot ◽  
Draft Genome ◽  
Broad Host Range ◽  
Genome Sequences ◽  
Genomic Resources ◽  
Root Rot Disease ◽  
The Family ◽  
Rot Disease ◽  
Phymatotrichopsis Omnivora

Phymatotrichopsis omnivora is a destructive plant pathogen causing root rot disease of alfalfa, cotton, pecan, grape, and many other important dicotyledonous species. A member of the family Rhizinaceae, in the class Pezizomycetes, P. omnivora is a soilborne ascomycete fungus that is difficult to maintain in culture, currently genetically intractable, and for which there are no publicly available genomic resources. We have generated draft genome sequences of four P. omnivora isolates obtained from cotton and alfalfa, growing in Texas and Oklahoma, USA. These genome sequences will provide new insights into the biology of the fungus, including the factors responsible for its broad host range and pathogenicity.

Host specificity and vegetative compatibility of Dutch isolates of Fusarium oxysporum f.sp. asparagi

1997 ◽  
Vol 75 (3) ◽  
pp. 383-393 ◽  
Author(s):  
Wim J. Blok ◽  
Gerrit J. Bollen
Keyword(s):  
Fusarium Oxysporum ◽  
Host Range ◽  
Plant Species ◽  
Root Rot ◽  
The United States ◽  
Vegetative Compatibility ◽  
Broad Host Range ◽  
Vegetative Compatibility Groups ◽  
Narrow Host Range

The host range of Fusarium oxysporum f.sp. asparagi (Foa) was studied in inoculation experiments with 21 plant species. Typical root rot symptoms were incited only in asparagus, in all experiments; lupin and pea were susceptible under in vitro conditions but showed only mild symptoms occasionally when tested in soil; none of the other species showed external disease symptoms. Root colonization by Foa was studied for 14 plant species. The pathogen was detected in externally disinfested roots of all species except leek and onion, with asparagus the most extensively colonized species. Asparagus was not susceptible to isolates of F. oxysporum f.sp. pisi, lupini, cepae, lilii, and gladioli and Fusarium sacchari var. elongatum. Naturally infested field soil was planted twice for 11 – 13 weeks with 11 plant species, including asparagus and several symptomless hosts, and subsequently with asparagus as a biotest plant. Of these crops, only asparagus greatly increased the severity of Foa root rot. It was concluded that Foa has a narrow host range as a pathogen but a broad host range as a parasite. The consequences of the latter for the epidemiology of Foa are discussed. Twenty-four Foa isolates were assigned to 18 different vegetative compatibility groups (VCGs); three additional F. oxysporum isolates, which were not pathogenic on asparagus, each belonged to a unique VCG. These findings indicate that the Dutch Foa population is very diverse genetically, as was found previously for the Foa population in the United States. Key words: asparagus, Fusarium oxysporum f.sp. asparagi, host range, lupin, pea, symptomless hosts, vegetative compatibility.

Thielaviopsis basicola. [Descriptions of Fungi and Bacteria].

1968 ◽  
Author(s):  
C. V. Subramanian
Keyword(s):  
Host Range ◽  
Geographical Distribution ◽  
Root Rot ◽  
Thielaviopsis Basicola ◽  
Black Root Rot ◽  
Wide Host Range ◽  
Sunn Hemp

Abstract A description is provided for Thielaviopsis basicola. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On a wide host range attacking plants in over fifteen families, primarily belonging to the Leguminosae (groundnut, soyabean, Lespedeza, clover, alfalfa, cowpea, lupin, sunn hemp, bean), Solanaceae (tobacco) and Cucurbitaceae; also from Citrus roots. DISEASES: Causes black root rot in tobacco and many other crops (see above). Recent reports suggest that it may be a serious pathogen on Citrus roots (39: 411; 42: 263, 761). Many species of Nicotiana are susceptible and some are considered resistant or immune (Johnson, 1916, J. agric. Res. 7: 289-300; 50: 248). GEOGRAPHICAL DISTRIBUTION: Africa (S. Africa, Egypt), Asia (Persia, Japan, India, Indonesia); Australasia (Australia, N. Zealand), Europe (Bulgaria, France, Germany, Italy, Netherlands, Norway, Poland, Rumania, Switzerland, U.S.S.R., Yugoslavia), N., C. and S. America. TRANSMISSION: Soil-borne; the pathogen is a soil inhabitant capable of prolonged saprophytic survival in soils.

scholarly journals Novel insect-specific Eilat virus-based chimeric vaccine candidates provide durable, mono- and multi-valent, single dose protection against lethal alphavirus challenge

2017 ◽  
pp. JVI.01274-17 ◽  
Author(s):  
Jesse H. Erasmus ◽  
Robert L. Seymour ◽  
Jason T. Kaelber ◽  
Dal Y. Kim ◽  
Grace Leal ◽  
...  
Keyword(s):  
Single Dose ◽  
Host Range ◽  
Severe Disease ◽  
Broad Host Range ◽  
Venezuelan Equine Encephalitis ◽  
Vaccine Platform ◽  
Lethal Challenge ◽  
Range Restriction ◽  
Newborn Mice ◽  
Domesticated Animals

Most alphaviruses are mosquito-borne and exhibit a broad host range, infecting many different vertebrates including birds, rodents, equids, humans and nonhuman primates. Recently, a host-restricted, mosquito-borne alphavirus, Eilat virus (EILV), was described with an inability to infect vertebrate cells based on defective attachment and/or entry as well as a lack of genomic RNA replication. We investigated the utilization of EILV recombinant technology as a vaccine platform against eastern (EEEV) and Venezuelan equine encephalitis viruses (VEEV), two important pathogens of humans and domesticated animals. EILV chimeras containing structural proteins of EEEV or VEEV were engineered and successfully rescued inAedes albopictuscells. Cryo-EM reconstructions at 8 and 11 Å of EILV/VEEV and EILV/EEEV, respectively, showed virion and glycoprotein spike structures similar to VEEV-Tc83 and other alphaviruses. The chimeras were unable to replicate in vertebrate cell lines or in brains of newborn mice when injected intracranially. Histopathologic examinations of the brain tissues showed no evidence of pathologic lesions, and were indistinguishable from those of mock-infected animals. A single-dose immunization of either monovalent or multivalent EILV chimera(s) generated neutralizing antibody responses and protected animals against lethal challenge 70 days later. Lastly, a single dose of monovalent EILV chimeras generated protective responses as early as day 1 post-vaccination, and partial or complete protection by day 6. These data demonstrate the safety, immunogenicity, and efficacy of novel insect-specific EILV-based chimeras as potential EEEV and VEEV vaccines.IMPORTANCEMostly in the last decade, insect-specific viruses have been discovered in several arbovirus families. However, most of these viruses are not well studied and largely have been ignored. We explored use of the mosquito-specific alphavirus, Eilat virus (EILV), as an alphavirus vaccine platform in well-established disease models for eastern (EEE) and Venezuelan equine encephalitis (VEE). EILV-based chimeras replicated to high titers in a mosquito cell line, yet retained their host range restriction in vertebrates bothin vitroandin vivo. In addition, the chimeras generated immune responses that were higher than other human and/or equine vaccines. These findings indicate the feasibility of producing a safe, efficacious, mono- or multi-valent vaccine against the encephalitic alphaviruses, VEEV and EEEV. Lastly, these data demonstrate how host restricted, insect-specific viruses can be engineered to develop vaccines against related pathogenic arboviruses that cause severe disease in humans and domesticated animals.

Waitea circinata var. zeae causing root rot of cabbage and oilseed rape

Plant Disease ◽  
2020 ◽  
Author(s):  
Mira Vojvodić ◽  
Brankica Tanovic ◽  
Petar Mitrovic ◽  
Ivana Vico ◽  
Aleksandra Bulajic
Keyword(s):  
Host Range ◽  
Oilseed Rape ◽  
Root Rot ◽  
Natural Infection ◽  
Broad Host Range ◽  
Oilseed Crop ◽  
Important Species ◽  
Group I ◽  
Waitea Circinata ◽  
Brassicaceae Family

Cabbage, a widely used and popular vegetable, and oilseed rape, the second most valuable oilseed crop in the world, are two important species from the Brassicaceae family. Two geographically separated outbreaks of cabbage and oilseed rape root rot with estimated incidence of 15% and 20%, respectively, were recorded during 2017 in the Vojvodina region, Serbia. Twelve hyphal-tip isolates were obtained from symptomatic cabbage and oilseed rape plants and identified as Waitea circinata var. zeae based on morphological and molecular features. This indicates that W. circinata var. zeae has expanded its host range to the Brassicaceae family. Sequence analyses of ITS and LSU of the rDNA, RPB2, and β-tubulin genes revealed the highest similarity with multiple W. circinata var. zeae. Neighbor-joining analyses of ITS sequences resulted in a phylogenetic tree with one well-defined branch of W. circinata var. zeae, with two separate groups. All Serbian isolates and the majority of isolates originating from natural infection of dicotyledonous plants grouped together in Group I. Following artificial inoculation, W. circinata var. zeae isolates caused mild to medium root necrosis of seedlings of 2 monocotyledonous and 12 dicotyledonous plant species, implying a wider host range than known for W. circinata var. zeae. Additionally, this is the first occurrence of W. circinata var. zeae on dicotyledonous host plants in Europe. As cabbage and oilseed rape are important crops grown worldwide, the occurrence of this new soil-borne pathogen with a broad host range imposes the necessity for changes in routine disease control practice, particularly crop rotation.

scholarly journals 1615. Isolation of Lytic Bacteriophages with Broad Host Range Activity Against Pseudomonas aeruginosa Strains Isolated from Respiratory Samples from Cystic Fibrosis Patients Intended for Therapeutic Application

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S801-S801
Author(s):  
Jose Alexander ◽  
Daniel Navas ◽  
Marly Flowers ◽  
Angela Charles ◽  
Amy Carr
Keyword(s):  
Cystic Fibrosis ◽  
Host Range ◽  
Phage Therapy ◽  
Clinical Isolates ◽  
Clinical Samples ◽  
Plaque Morphology ◽  
Broad Host Range ◽  
Chronic Infections ◽  
Clinically Significant ◽  
Host Target

Abstract Background With the rise of the antimicrobial resistance between different genera and species of bacteria, Phage Therapy is becoming a more realistic and accessible option for patients with limited or no antimicrobial options. Being able to have rapid access to a collection of clinical active phages is key for rapid implementation of phage therapy. The Microbiology Department at AdventHealth Orlando is performing routine screening of environmental and patient samples for isolation of phages against non-fermenting Gram negative bacteria to develop a Phage Bank. Methods Protocols for phage isolation from environmental sources such as lakes, rivers and sewers and clinical samples were developed. A series of respiratory, throat, stool and urine samples were processed following an internal protocol that includes centrifugation, filtration and enrichment. Clinical samples were centrifugated for 10 minutes, filtered using 0.45µm centrifugation filters, seeded with targeted host bacteria (clinical isolates) and incubated at 35°C for 24 hours. The enriched samples were centrifugated and filtered for a final phage enriched solution. Screening and isolation were performed using the Gracia method over trypticase soybean agar (TSA) for plaque morphology and quantification. Host range screening of other clinical isolates of P. aeruginosa was performed using the new isolated and purified phages. Results 4 lytic phages against clinical strains of P. aeruginosa from patient with diagnosis of cystic fibrosis (CF), were isolated and purified from 4 different respiratory samples, including sputum and bronchial alveolar lavage. All phages showed phenotypical characteristics of lytic activity. 1 phage was active against 4 strains of P. aeruginosa, 1 phage was active against 2 strains of P. aeruginosa and the remaining 2 phages were active only against the initial host target strain. Conclusion With this study we demonstrated the potential use of clinical samples as source for isolating active bacteriophages against clinically significant bacteria strains. Clinical samples from vulnerable population of patients with chronic infections are part of our routine “phage-hunting” process to stock and grow our Phage Bank project for future clinical use. Disclosures All Authors: No reported disclosures

scholarly journals Revealing biophysical properties of KfrA-type proteins as a novel class of cytoskeletal, coiled-coil plasmid-encoded proteins

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
M. Adamczyk ◽  
E. Lewicka ◽  
R. Szatkowska ◽  
H. Nieznanska ◽  
J. Ludwiczak ◽  
...  
Keyword(s):  
Dna Binding ◽  
Host Range ◽  
Coiled Coil ◽  
Amino Acid Sequences ◽  
Broad Host Range ◽  
Biophysical Properties ◽  
Dna Binding Sites ◽  
In Silico Studies ◽  
Wide Range

Abstract Background DNA binding KfrA-type proteins of broad-host-range bacterial plasmids belonging to IncP-1 and IncU incompatibility groups are characterized by globular N-terminal head domains and long alpha-helical coiled-coil tails. They have been shown to act as transcriptional auto-regulators. Results This study was focused on two members of the growing family of KfrA-type proteins encoded by the broad-host-range plasmids, R751 of IncP-1β and RA3 of IncU groups. Comparative in vitro and in silico studies on KfrAR751 and KfrARA3 confirmed their similar biophysical properties despite low conservation of the amino acid sequences. They form a wide range of oligomeric forms in vitro and, in the presence of their cognate DNA binding sites, they polymerize into the higher order filaments visualized as “threads” by negative staining electron microscopy. The studies revealed also temperature-dependent changes in the coiled-coil segment of KfrA proteins that is involved in the stabilization of dimers required for DNA interactions. Conclusion KfrAR751 and KfrARA3 are structural homologues. We postulate that KfrA type proteins have moonlighting activity. They not only act as transcriptional auto-regulators but form cytoskeletal structures, which might facilitate plasmid DNA delivery and positioning in the cells before cell division, involving thermal energy.

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