Potential for recombinant Babesia bovis antigens to protect against a highly virulent isolate

The fungus Cylindrocarpon destructans (Zins) Scholten is the cause of root rot (disappearing root rot) in many ginseng production areas in Canada. A total of 80 isolates of C. destructans were recovered from diseased roots in a survey of ginseng gardens in British Columbia from 2002-2004. Among these isolates, 49% were classified as highly virulent (causing lesions on unwounded mature roots) and 51% were weakly virulent (causing lesions only on previously wounded roots). Pectinase and polyphenoloxidase enzymes were produced in vitro by C. destructans isolates when they were grown on pectin and phenol as a substrate, respectively. However, highly virulent isolates produced significantly (P < 0.001) higher enzyme levels compared with weakly virulent isolates. Histopathological studies of ginseng roots inoculated with a highly virulent isolate revealed direct hyphal penetration through the epidermis, followed by intracellular hyphal growth in the cortex. Subsequent cell disintegration and accumulation of phenolic compounds was observed. Radial growth of highly and weakly virulent isolates on potato dextrose agar was highest at 18 and 21°C, respectively and there was no growth at 35°C. Mycelial mass production was significantly (P ≤ 0.01) lower at pH 7.0 compared with pH 5.0. To study the effects of pH (5.0 and 7.0) and wounding on disease development, ginseng roots were grown hydroponically in Hoagland's solution. Lesions were significantly larger (P < 0.001) at pH 5.0 compared with pH 7.0 and wounding enhanced disease by a highly virulent isolate at both pHs. In artificially infested soil, 2-year-old ginseng roots were most susceptible to Cylindrocarpon root rot among all root ages tested (1 to 4 years) when evaluated using a combined scale of disease incidence and severity. Root rot severity was significantly (P < 0.002) enhanced by increasing the inoculum density from 3.45 × 102 CFU/g of soil to 1.86 × 103 CFU/g of soil. Disease severity was higher at 20°C compared with 15 and 25°C and at -0.02 MPa soil moisture compared with -0.005 and -0.001 MPa. A significant interaction between soil moisture and temperature was observed for root rot severity.

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Peer Review #2 of "Evaluation of a type 2 modified live porcine reproductive and respiratory syndrome vaccine against heterologous challenge of a lineage 3 highly virulent isolate in pigs (v0.1)"

10.7287/peerj.8840v0.1/reviews/2 ◽

2020 ◽

Keyword(s):

Peer Review ◽

Virulent Isolate ◽

Heterologous Challenge ◽

Highly Virulent

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Variability and Virulence Analysis of Aspergillus niger Isolates Causing Collar Rot of Groundnut

Legume Research - An International Journal ◽

10.18805/lr-4854 ◽

2022 ◽

Author(s):

Tejpal Bajaya ◽

R.P. Ghasolia ◽

Mamta Bajya ◽

Manisha Shivran

Keyword(s):

Aspergillus Niger ◽

Disease Incidence ◽

Morphological Variability ◽

Economic Losses ◽

Resistance Response ◽

Collar Rot ◽

Virulent Isolate ◽

Resistant Varieties ◽

Severe Constraint ◽

Highly Virulent

Background: Collar rot of groundnut (Arachis hypogaea L.) caused by Aspergillus niger is a significant constraint in groundnut cultivation and responsible for huge economic losses in India including Rajasthan. Methods: By surveying of eight major groundnut growing districts of Rajasthan, India, one representative Aspergillus niger isolate from each district was established (ANBK-01= Bikaner, ANCH-02= Churu, ANDA-03= Dausa, ANJP-04= Jaipur, ANJL-05= Jalore, ANJD-06= Jodhpur, ANNG-07= Nagaur and ANSK-08= Sikar) for studying variability in the pathogen as well as to know the response of groundnut varieties to the highly virulent isolate. The colony and spore characteristics were observed for cultural and morphological variability. For resistance response to the disease, ten varieties (M-13, RG-633-9, RG-382, Girnar-2, RG-604, RG-578, Gajraj 10, RG-510, RG-632-1 and RG-644) were evaluated in the field for two consecutive years against a highly virulent Aspergillus niger (ANJP-04) isolate. Result: Our investigations cleared that all the isolates were showed cultural and morphological variability such as shape, colour and size of colony and size of conidia, conidiophores and columella. Isolate (ANJP-04) collected from Khejroli village of Chomu tehsil in Jaipur district showed maximum mycelial growth, conidia diameter, length and diameter of conidiophores and length and diameter of columella, early sporulation and found most virulent as it produced higher disease incidence (54.43%). Ten released varieties of groundnut in the field conditions, revealed that none of the variety was found completely free from the disease whereas RG-644, M-13 and RG-510 were found resistant while RG-604, Girnar-2, Gajraj-10 and RG-632-1 were found moderately resistant and rest were found susceptible to highly susceptible to the disease. Conclusively, it can be finalized that famers may cultivate these resistant varieties in areas where collar rot is a severe constraint. The conclusion of this study can also be utilized to screen varieties/genotypes of groundnut against highly virulent isolate for sustainability of breeding material to the disease effectively.

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Functional Expression of the Gene cu, Encoding the Phytotoxic Hydrophobin Cerato-ulmin, Enables Ophiostoma quercus, a Nonpathogen on Elm, to Cause Symptoms of Dutch Elm Disease

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.2000.13.1.43 ◽

2000 ◽

Vol 13 (1) ◽

pp. 43-53 ◽

Cited By ~ 27

Author(s):

Giovanni Del Sorbo ◽

Felice Scala ◽

Giuseppe Parrella ◽

Matteo Lorito ◽

Cecilia Comparini ◽

...

Keyword(s):

Vascular Tissue ◽

Functional Expression ◽

Dutch Elm Disease ◽

Enzyme Linked Immunosorbent Assay ◽

Virulent Isolate ◽

Vascular Discoloration ◽

Encoding Gene ◽

Moderately Resistant ◽

Highly Virulent

We studied the involvement of the phytotoxic hydrophobin cerato-ulmin (CU) in pathogenesis and virulence of Dutch elm disease (DED) by expressing its encoding gene (cu) in Ophiostoma quercus, a nonpathogenic species on elm closely related to the DED pathogens O. ulmi and O. novo-ulmi. The production of the toxin was quantitatively determined in culture filtrates and in mycelial extracts of the transformants. Production of CU in vitro was associated with the ability to cause typical DED symptoms, consisting of foliar yellow and wilting and vascular tissue discoloration on a moderately resistant elm genotype. The presence of CU was monitored by enzyme-linked immunosorbent assay in symptomatic leaves of plants inoculated with O. quercus transformants expressing CU and found to be associated with wilt symptoms. In general, the virulence of the cu-expressing transformants, as measured in terms of vascular discoloration and percentage of defoliation, was lower than that of the mildly pathogenic isolate E2 of O. ulmi. However, one transformant (C39) displayed a virulence level intermediate between that of E2 and 182, a highly virulent isolate of O. novo-ulmi. Our results indicate that CU production influences virulence in nonaggressive strains of Ophiostoma fungi.

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Peer Review #1 of "Evaluation of a type 2 modified live porcine reproductive and respiratory syndrome vaccine against heterologous challenge of a lineage 3 highly virulent isolate in pigs (v0.2)"

10.7287/peerj.8840v0.2/reviews/1 ◽

2020 ◽

Author(s):

R Mickaël

Keyword(s):

Peer Review ◽

Virulent Isolate ◽

Heterologous Challenge ◽

Highly Virulent

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Peer Review #1 of "Evaluation of a type 2 modified live porcine reproductive and respiratory syndrome vaccine against heterologous challenge of a lineage 3 highly virulent isolate in pigs (v0.1)"

10.7287/peerj.8840v0.1/reviews/1 ◽

2020 ◽

Author(s):

R Mickaël

Keyword(s):

Peer Review ◽

Virulent Isolate ◽

Heterologous Challenge ◽

Highly Virulent

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Verticillium Wilt of Paprika Caused by a Highly Virulent Isolate of Verticillium dahliae

Plant Disease ◽

10.1094/pdis.1998.82.4.437 ◽

1998 ◽

Vol 82 (4) ◽

pp. 437-439 ◽

Cited By ~ 17

Author(s):

Leah Tsror (Lahkim) ◽

Orly Erlich ◽

Sarit Amitai ◽

Marina Hazanovsky

Keyword(s):

Verticillium Dahliae ◽

Agar Medium ◽

Disease Symptoms ◽

Virulent Isolate ◽

Pathogenicity Tests ◽

Potato Isolate ◽

Dahliae Isolate ◽

Early Dying ◽

Pathogen Colonization ◽

Highly Virulent

Verticillium dahliae caused wilting, stunting and early dying of paprika plants in Israel, resulting in a 22% reduction in yield. A V. dahliae isolate from diseased paprika plants was slower growing on agar medium than V. dahliae isolates from potato, tomato, watermelon, and Dodonaea, but formed microsclerotia earlier. The paprika isolate of V. dahliae was highly virulent to paprika in pathogenicity tests. Disease severity indices obtained from three paprika cultivars ranged from 3.7 to 4.9 (on a scale of 0 to 5). The disease caused height reductions of 43 to 62% in the three inoculated paprika cultivars, and pathogen colonization levels were 10- to 35-fold higher in stems than in leaves. The potato isolate of V. dahliae did not produce symptoms or cause stunting of paprika, and could not be detected in stems or leaves. The tomato, watermelon, and Dodonaea isolates did not cause disease symptoms in paprika, although they colonized the plant tissue. In potato and eggplant, the paprika isolate caused a higher incidence of disease with more severe symptoms and a higher level of tissue colonization than did the potato isolate.

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Evaluation of a type 2 modified live porcine reproductive and respiratory syndrome vaccine against heterologous challenge of a lineage 3 highly virulent isolate in pigs

PeerJ ◽

10.7717/peerj.8840 ◽

2020 ◽

Vol 8 ◽

pp. e8840 ◽

Cited By ~ 1

Author(s):

Fu-Hsiang Hou ◽

Wei-Cheng Lee ◽

Jiunn-Wang Liao ◽

Maw-Sheng Chien ◽

Chih-Jung Kuo ◽

...

Keyword(s):

Respiratory Distress ◽

Protective Efficacy ◽

Mutation Rates ◽

Post Challenge ◽

Swine Industry ◽

Virulent Isolate ◽

Heterologous Challenge ◽

Lower Magnitude ◽

Highly Virulent

Porcine reproductive and respiratory syndrome (PRRS) is one of the most common diseases in the global swine industry. PRRSV is characterized by rapid mutation rates and extensive genetic divergences. It is divided into two genotypes, which are composed of several distinct sub-lineages. The purpose of the present study was to evaluate the cross-protective efficacy of Fostera PRRS MLV, an attenuated lineage 8 strain, against the heterologous challenge of a lineage 3 isolate. Eighteen pigs were randomly divided into mock, MLV and unvaccinated (UnV) groups. The pigs in the MLV group were administered Fostera PRRS vaccine at 3 weeks of age and both the MLV and UnV groups were inoculated with a virulent PRRSV isolate at 7 weeks. Clinically, the MLV group showed a shorter duration and a lower magnitude of respiratory distress than the UnV group. The average days of fever in the MLV group was 3.0 ± 0.5, which was significantly lower than the 6.2 ± 0.5 days of the UnV group (P < 0.001). The average daily weight gains of the mock, MLV and UnV groups were 781 ± 31, 550 ± 44 and 405 ± 26 g/day, respectively, during the post-challenge phase. The pathological examinations revealed that the severity of interstitial pneumonia in the MLV group was milder compared to the UnV group. Furthermore, PRRSV viremia titers in the MLV pigs were consistently lower (101−101.5 genomic copies) than those of the UnV pigs from 4 to 14 DPC. In conclusion, vaccination with Fostera PRRS MLV confers partial cross-protection against heterologous challenge of a virulent lineage 3 PRRSV isolate.

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