scholarly journals First Report of Filamentous Phages Isolated from Tunisian Orchards to Control Erwinia amylovora

2020 ◽  
Vol 8 (11) ◽  
pp. 1762
Author(s):  
Ismahen Akremi ◽  
Dominique Holtappels ◽  
Wided Brabra ◽  
Mouna Jlidi ◽  
Adel Hadj Ibrahim ◽  
...  
Keyword(s):  
Illumina Sequencing ◽  
Erwinia Amylovora ◽  
Single Strand ◽  
Biocontrol Agents ◽  
Swarming Motility ◽  
First Report ◽  
Infected Cells ◽  
Filamentous Phages

Newly discovered Erwinia amylovora phages PEar1, PEar2, PEar4 and PEar6 were isolated from three different orchards in North Tunisia to study their potential as biocontrol agents. Illumina sequencing revealed that the PEar viruses carry a single-strand DNA genome between 6608 and 6801 nucleotides and belong to the Inoviridae, making them the first described filamentous phages of E. amylovora. Interestingly, phage-infected cells show a decreased swimming and swarming motility and a cocktail of the four phages can significantly reduce infection of E. amylovora in a pear bioassay, potentially making them suitable candidates for phage biocontrol.

scholarly journals Leishmania Infection of Canine Skin Fibroblasts In Vivo

1996 ◽  
Vol 33 (4) ◽  
pp. 469-473 ◽  
Author(s):  
J. Hervás Rodríguez ◽  
E. Mozos ◽  
A. Méndez ◽  
J. Pérez ◽  
J. C. Gómez-Villamandos
Keyword(s):  
Skin Fibroblasts ◽  
Leishmania Infection ◽  
First Report ◽  
Naturally Occurring ◽  
Infected Cells

In this paper we describe two cases of naturally occurring leishmaniasis in dogs in which Leishmania sp. amastigotes are found within the cytoplasm of fibroblasts. The infected cells were identified histologically, immunohistochemically, and ultrastructurally as fibroblasts. This is the first report of leishmaniasis in any species in which amastigotes were identified in vivo within fibroblasts.

scholarly journals First Report of Fire Blight on Pear Trees Caused by Erwinia amylovora in Kurdistan Province, Iran

Plant Disease ◽  
2013 ◽  
Vol 97 (8) ◽  
pp. 1111-1111 ◽  
Author(s):  
S. N. Mollaei ◽  
B. Harighi
Keyword(s):  
Fire Blight ◽  
Erwinia Amylovora ◽  
Reca Gene ◽  
Phylogenetic Position ◽  
Bacterial Suspension ◽  
Sodium Hypochlorite Solution ◽  
Pathogenicity Test ◽  
First Report ◽  
Appl Environ ◽  
Pear Trees

Pear (Pyrus L.) is one of the most widely grown crops in western Iran. Since 2010, an outbreak of a disease with symptoms similar to fire blight has been observed on pear trees in various locations of Kurdistan Province. Initial flower symptoms include water-soaking and rapidly shriveling, infected flowers that remained hanging on the trees. Immature fruits become water-soaked, turned brown, and shriveled. Infected flowers and immature fruits were collected from different locations in the province. Small pieces (about 1 mm2) were excised from infected tissues, surface sterilized with 0.5% sodium hypochlorite solution, followed by rinsing in sterile-distilled water (SDW). Each piece was macerated in 2 to 3 ml of SDW, streaked onto nutrient agar sucrose or eosin methylene blue agar media, and incubated at 27 to 29°C. After 48 to 72 h, single colonies were subcultured onto the same media and stored at 4°C. In total, 74 bacteria were isolated from infected tissues. All isolates were gram-negative and rod-shaped. Based on other phenotypic properties, strains were grouped into three clusters at a similarity level of 65% (data not shown). Forty-one and 23 strains showed properties as expected for Erwinia amylovora and Enterobacter sp., respectively. Other strains showed properties resembling Pantoea agglomerans. All strains identified as E. amylovora produced an expected DNA fragment of about 900 bp by PCR using primers PE29A and PE29B corresponding to plasmid pEA29 (1). The result was confirmed by using primers AMSbL and AMSbR derived from the ams region required for amylovoran synthesis of E. amylovora. E. amylovora strains produced an expected 1,600-bp fragment (2). For the pathogenicity test, a bacterial suspension was adjusted to approximately 1 × 107 CFU/ml from cell cultures grown in nutrient broth at 27°C for 48 h. Immature pear fruits sterilized with 70% ethanol and rinsed with SDW were injected with the bacterial suspension using a 25-gauge sterile needle. Fruits injected with sterile water were used as controls. Pear fruits were kept in a mist chamber at 27 to 29°C. Symptoms were assessed up to 2 weeks after inoculation. All E. amylovora strains produced typical symptoms on inoculated immature pear fruits. Necrosis and oozing of bacterial exudates were observed after 3 to 7 days. The phylogenetic position of two selected strains was analyzed by sequence comparison of recA gene among other species in the genus Erwinia and related bacteria. The recA sequence of bacterial strains identified as E. amylovora revealed high similarity (99%) to the E. amylovora type strain (CFBP 1430). Genetic diversity of selected strains was assessed and compared with E. amylovora reference strain CFBP 1430 using ERIC and REP primers in rep-PCR analysis. (3). UPGMA cluster analysis of the combined data obtained in the rep-PCR experiments using Dice's coefficient revealed that the majority of E. amylovora strains showed the same fingerprint patterns at a similarity level of 93%, indicating genetic homogeneity among strains but clearly separated from Enterobacter sp. and P. agglomerans strains. To our knowledge, this is the first report that characterizes the phenotypic and genetic properties of E. amylovora in western part of Iran. References: (1) S. Bereswill et al. Appl. Environ. Microbiol. 58:3522, 1992. (2) S. Bereswill et al. Appl. Environ. Microbiol. 61:2636, 1995. (3) J. Versalovic et al. Mol. Cell Biol. 5:25, 1994.

scholarly journals First Report of Fire Blight on Pyrus elaeagrifolia and Amelanchier sp. in Bulgaria

Plant Disease ◽  
2007 ◽  
Vol 91 (1) ◽  
pp. 110-110 ◽  
Author(s):  
S. G. Bobev ◽  
J. Van Vaerenbergh ◽  
M. Maes
Keyword(s):  
Fire Blight ◽  
Erwinia Amylovora ◽  
Hypersensitive Reaction ◽  
Sterile Water ◽  
First Report ◽  
Progressive Necrosis ◽  
Park Area ◽  
First Time ◽  
Pyrus Elaeagrifolia ◽  
Positive Results

In 2005, a fire blight epidemic occurred for the second time within the last 3 years, and severe damages were observed on pome fruits trees in many regions of Bulgaria. For the first time, we found fire blight on Pyrus elaeagrifolia and Amelanchier sp. grown in a park area (Plovdiv Region), providing evidence of continuing spread of the pathogen in Bulgaria. The symptoms on P. elaeagrifolia were necrotic, immature fruitlets and progressive necrosis toward the adjacent branches, thus forming cankers and leading to death of the plant above the canker. Many Amelanchier sp. shrubs had severely blighted flowers, fruitlets, shoots, and branches and dried, amber ooze droplets on the shoots. All the isolations made from blighted hosts' shoots and cankers on King's medium B (2 to 3 days, 26 to 27°C) yielded whitish, glistening, round bacterial colonies. Infiltration of the suspensions of randomized isolates from both hosts into tobacco leaves resulted in a typical hypersensitive reaction. Subsequently, some strains showed a typical ooze production on immature pear fruits (cv. Conference) and were also successfully reisolated from artificially inoculated quince shoots (1.2 × 109 CFU, cv. Portugalska, three replicates), where typical fire blight symptoms were observed, thereby fulfilling Koch's postulates. No symptoms or bacteria were found within any of the shoots from the same plant species injected with sterile water. The identity of the isolates was confirmed as Erwinia amylovora by an antibody-based slide agglutination test (Neogen_Express; Neogen Europe, Ltd., UK) and PCR test with primers derived from the ams region (1). On the basis of the symptoms, cultural characteristics, and positive results in pathogenicity, serological, and PCR tests, the isolates were considered to be E. amylovora. To our knowledge, this is the first report of fire blight on P. elaeagrifolia and Amelanchier sp. in Bulgaria. Reference: (1) S. Bereswill et al. Appl. Environ. Microbiol. 61:2636, 1995.

scholarly journals First Report of Fire Blight Caused by Erwinia amylovora on Meadowsweet (Spirea prunifolia) in Turkey

Plant Disease ◽  
2014 ◽  
Vol 98 (1) ◽  
pp. 153-153 ◽  
Author(s):  
K. K. Bastas ◽  
F. Sahin
Keyword(s):  
Pathogenic Bacteria ◽  
Fire Blight ◽  
Erwinia Amylovora ◽  
Natural Infection ◽  
Hypodermic Needle ◽  
Identification System ◽  
Bacterial Strains ◽  
First Report ◽  
Molecular Tests ◽  
Initial Symptoms

Fire blight, caused by Erwinia amylovora (Burr.) Winslow et al., affects plants in the Rosaceae family, which includes trees and shrubs in orchards, nurseries, and landscape plantations. During the springs and summers of 2008 and 2010, dying branches, necrotic leaves attached to shoots, and blighted twigs of meadowsweet (Spirea prunifolia) were observed at three different locations of landscape areas in Konya Province, Turkey. Disease incidence was approximately 1% on the plants during the surveys. Initial symptoms of reddish to brownish streaks on the shoots of infected plants were observed in spring. Nine representative bacterial strains were isolated from the lesions on shoots of seven meadowsweet plants on nutrient sucrose agar (NSA) medium and identified as E. amylovora on basis of biochemical, physiological (2,3) and molecular tests (1). Bacteria were gram-negative, rod shaped, aerobic, fermentative, yellow-orange on Miller and Scroth medium (2), positive for levan formation and acetoin production, did not grow at 36°C, positive for gelatin hydrolysis, and negative for esculin hydrolysis, indole, urease, catalase, oxidase, arginine dehydrolase, reduction of nitrate, acid production from lactose, and inositol. All strains were hypersensitive response-positive on tobacco (Nicotiana tabacum var. White Burley) plants. All strains were identified as E. amylovora using the species-specific primers set, A/B (1), by PCR assay, and by fatty acid methyl ester (FAME) profiles determined by Sherlock Microbial Identification System software (TSBA 6 v. 6.00; Microbial ID, Newark, DE) with similarity indices ranging from of 79 to 99%. Pathogenicity was tested by injecting of petioles and actively growing three shoot tips of 2-year-old S. prunifolia seedlings cv. number 29 using a 0.46 mm-diameter hypodermic needle with bacterial suspensions containing 108 CFU mL–1 in sterile distilled water (SDW) Plants were inoculated with each of the nine bacterial strains and two references strains, Ea29 and NCPPB 2791 (Selcuk University, Department of Plant Protection, Konya, Turkey). Symptoms resembling those associated with natural infection appeared on the inoculated plants 7 days after inoculation. Plants inoculated with SDW served as a negative control treatment, and no symptoms were observed on these plants. All tests were repeated three times with the same results. Bacterial re-isolations were attempted from the control plants as well as shoots and leaves inoculated with the two reference strains and the nine bacteria identified as E. amylovora. Bacteria isolated from inoculated plants were identified as E. amylovora using the biochemical, physiological, and molecular tests described above, but this bacterium was not isolated from the control plants. Phytosanitary measures must be taken to avoid spread of the pathogen to ornamentals in new landscape areas in Turkey. This report is important because infected Spirea spp. can be a potential inoculum source for other rosaceous ornamentals. To our knowledge, this is the first report of the occurrence of fire blight on meadowsweet in Turkey. References: (1) S. Bereswill et al. Appl. Environ. Microbiol. 58:3522, 1992. (2) A. L. Jones and K. Geider. Laboratory Guide for Identification of Plant Pathogenic Bacteria, pp. 40-55. American Phytopathological Society, St. Paul, MN, 2001. (3) R. A. Lelliott and D. E. Stead. Methods for Diagnosis of Bacterial Diseases of Plants (Methods in Plant Pathology). Oxford, UK, 1987.

scholarly journals Bee Vectoring: Development of the Japanese Orchard Bee as a Targeted Delivery System of Biological Control Agents for Fire Blight Management

Pathogens ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 41 ◽  
Author(s):  
Neelendra K. Joshi ◽  
Henry K. Ngugi ◽  
David J. Biddinger
Keyword(s):  
Biological Control ◽  
Targeted Delivery ◽  
Fire Blight ◽  
Erwinia Amylovora ◽  
The United States ◽  
Biocontrol Agents ◽  
Efficient System ◽  
Control Product ◽  
Tree Fruits ◽  
Potential Use

Fire blight, which is caused by the bacteria Erwinia amylovora, remains one of the most important diseases limiting the productivity of apple and pear orchards in the United States. In commercial orchards, in-season fire blight management relies exclusively on the use of antibiotic treatments (such as streptomycin and oxytetracycline) and on bacterial biocontrol agents whose efficacy is limited. We hypothesize that the efficacy of the biocontrol agents can be greatly enhanced through targeted delivery to flowers, which serve as initial infection courts, using the Japanese orchard bee, Osmia cornifrons. Many factors, such as the synchrony of life cycle with plant phenology and specificity to pomaceous plants, suggest that O. cornifrons could be an excellent vector of the biocontrol products during bloom in pome tree fruits. However, deployment of this pollinator species to deliver biocontrol agents for fire blight control has not been attempted previously due to the lack of an efficient system to pack the bodies of the bees exiting nesting tubes with the biocontrol products. In this study, we design and test a dispenser system to facilitate the use of O. conifrons as a vector for commercially available biocontrol products for fire blight control. The effectiveness of O. conifrons to deliver biocontrol agents to flowers, and to effect secondary dissemination from treated to untreated flowers is also evaluated in greenhouse experiments. We found that the O. conifrons bees were able to use the nest dispenser designed for the delivery of biological control products, and are effective in vectoring and delivering the Bacillus subtilis-based biological control product (Serenade®) to apple blossoms. We also found that the O. cornifrons were effective in secondary inoculation of this biological control product to newly-opened flowers. These findings suggest the potential use of commercially available O. conifrons and other orchard bees in targeted delivery of biological control products for fire blight, and possibly other diseases, in different fruit crops.

scholarly journals Loss of Virulence of the Phytopathogen Ralstonia solanacearum Through Infection by φRSM Filamentous Phages

2012 ◽  
Vol 102 (5) ◽  
pp. 469-477 ◽  
Author(s):  
Hardian S. Addy ◽  
Ahmed Askora ◽  
Takeru Kawasaki ◽  
Makoto Fujie ◽  
Takashi Yamada
Keyword(s):  
Ralstonia Solanacearum ◽  
Virulence Genes ◽  
Host Cells ◽  
Extracellular Polysaccharides ◽  
Twitching Motility ◽  
Wild Type ◽  
Tomato Plants ◽  
Type Iv ◽  
Infected Cells ◽  
Filamentous Phages

φRSM1 and φRSM3 (φRSM phages) are filamentous phages (inoviruses) that infect Ralstonia solanacearum, the causative agent of bacterial wilt. Infection by φRSM phages causes several cultural and physiological changes to host cells, especially loss of virulence. In this study, we characterized changes related to the virulence in φRSM3-infected cells, including (i) reduced twitching motility and reduced amounts of type IV pili (Tfp), (ii) lower levels of β-1,4-endoglucanase (Egl) activity and extracellular polysaccharides (EPS) production, and (iii) reduced expression of certain genes (egl, pehC, phcA, phcB, pilT, and hrpB). The significantly lower levels of phcA and phcB expression in φRSM3-infected cells suggested that functional PhcA was insufficient to activate many virulence genes. Tomato plants injected with φRSM3-infected cells of different R. solanacearum strains did not show wilting symptoms. The virulence and virulence factors were restored when φRSM3-encoded orf15, the gene for a putative repressor-like protein, was disrupted. Expression levels of phcA as well as other virulence-related genes in φRSM3-ΔORF15-infected cells were comparable with those in wild-type cells, suggesting that orf15 of φRSM3 may repress phcA and, consequently, result in loss of virulence.

scholarly journals Predation of the Japanese keelback (Hebius vibakari Boie, 1826) by the Slender racer (Orientocoluber spinalis Peters, 1866)

2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Il-Kook Park ◽  
Jaejin Park ◽  
Jiho Park ◽  
Seong-Hun Min ◽  
Alejandro Grajal-Puche ◽  
...  
Keyword(s):  
Illumina Sequencing ◽  
Fecal Sample ◽  
Prey Item ◽  
New Genus ◽  
Prey Species ◽  
Diet Analysis ◽  
Republic Of Korea ◽  
Ecological Knowledge ◽  
Snake Species ◽  
First Report

Abstract Background The Slender racer (Orientocoluber spinalis Peters, 1866) has recently been reclassified to the new genus Orientocoluber from Hierophis. Ecological knowledge of this species is limited due to its highly mobile behavior. On 17 July 2020, we captured a female O. spinalis on Oeyeon Island, Boryeong-si, Republic of Korea, and collected its feces for a diet analysis. We observed snake scales from the collected feces and subsequently determined the prey species through morphological and molecular methods. Results We initially hypothesized that the extracted fecal sample scales belonged to H. vibakari, due to their thin keel and rhombus shape. We also amplified H. vibakari DNA from the extracted fecal sample using Illumina sequencing methods. Our morphological and molecular results suggest that O. spinalis predates H. vibakari on Oeyeon Island. Conclusion This is the first report of O. spinalis predating another snake species, ophiophagy, and implies that H. vibakari may be a crucial prey item for O. spinalis on Oeyeon Island.

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