Diversity and virulence of Streptomyces spp. causing potato common scab in Prince Edward Island, Canada

2020 ◽  
Author(s):  
Cindy Hudec ◽  
Amy Novinscak ◽  
Martin Filion
Keyword(s):  
Prince Edward Island ◽  
Common Scab ◽  
Phenotypic Diversity ◽  
Potato Disease ◽  
Chain Reactions ◽  
Polymerase Chain Reactions ◽  
Streptomyces Spp ◽  
Genetic Groups ◽  
Efficient Detection ◽  
Potato Common Scab

Common scab (CS) is a potato disease that significantly decreases the market value of potato tubers following the development of necrotic lesions on their surface. Streptomyces scabiei is the main causal agent of CS; however, other closely related species, including S. acidiscabies and S. turgidiscabies, have also been shown to cause the disease. In this study, we characterized the genetic and phenotypic diversity of Streptomyces spp. causing CS in Prince Edward Island, the main potato-producing province in Canada. Two hundred and ninety-six pathogenic Streptomyces spp. isolates were retrieved from diseased tubers harvested from six fields located across a longitudinal geographical gradient. Genome fingerprinting analyses using Repetitive elements Polymerase Chain Reactions (PCR) (ERIC- and BOX-PCR) revealed 14 distinct genetic groups. Thirteen of them were taxonomically affiliated with S. scabiei, while the fourteenth group was affiliated with S. acidiscabies. Their geographical distribution was characterized and revealed that on average between six and eight different genetic groups were detected per field, with variable abundance. Virulence assays showed strong differences in virulence between the genetic groups, ranging them from low to highly virulent. Interestingly, pathogenic Streptomyces spp. populations in each field seem to be dominated by the most virulent genetic groups. The results obtained will contribute to better understand the population dynamic of pathogenic Streptomyces spp. causing common scab of potato and promoting the development of more efficient detection and intervention tools to manage this important potato disease.

scholarly journals Comparative Genomics of Potato Common Scab-Causing Streptomyces spp. Displaying Varying Virulence

2021 ◽  
Vol 12 ◽  
Author(s):  
Cindy Hudec ◽  
Adrien Biessy ◽  
Amy Novinscak ◽  
Renée St-Onge ◽  
Simon Lamarre ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Prince Edward Island ◽  
Common Scab ◽  
Potato Production ◽  
Biosynthetic Gene Cluster ◽  
Economic Losses ◽  
Clear Correlation ◽  
Thaxtomin A ◽  
Streptomyces Spp ◽  
Potato Common Scab

Common scab of potato causes important economic losses worldwide following the development of necrotic lesions on tubers. In this study, the genomes of 14 prevalent scab-causing Streptomyces spp. isolated from Prince Edward Island, one of the most important Canadian potato production areas, were sequenced and annotated. Their phylogenomic affiliation was determined, their pan-genome was characterized, and pathogenic determinants involved in their virulence, ranging from weak to aggressive, were compared. 13 out of 14 strains clustered with Streptomyces scabiei, while the last strain clustered with Streptomyces acidiscabies. The toxicogenic and colonization genomic regions were compared, and while some atypical gene organizations were observed, no clear correlation with virulence was observed. The production of the phytotoxin thaxtomin A was also quantified and again, contrary to previous reports in the literature, no clear correlation was found between the amount of thaxtomin A secreted, and the virulence observed. Although no significant differences were observed when comparing the presence/absence of the main virulence factors among the strains of S. scabiei, a distinct profile was observed for S. acidiscabies. Several mutations predicted to affect the functionality of some virulence factors were identified, including one in the bldA gene that correlates with the absence of thaxtomin A production despite the presence of the corresponding biosynthetic gene cluster in S. scabiei LBUM 1485. These novel findings obtained using a large number of scab-causing Streptomyces strains are challenging some assumptions made so far on Streptomyces’ virulence and suggest that other factors, yet to be characterized, are also key contributors.

scholarly journals Characterization of a New Streptomyces Strain, DS3024, That Causes Potato Common Scab

Plant Disease ◽  
2009 ◽  
Vol 93 (12) ◽  
pp. 1329-1334 ◽  
Author(s):  
J. J. Hao ◽  
Q. X. Meng ◽  
J. F. Yin ◽  
W. W. Kirk
Keyword(s):  
Common Scab ◽  
Potato Tubers ◽  
North Central ◽  
Thaxtomin A ◽  
The North ◽  
Streptomyces Spp ◽  
Common Marker ◽  
Central United States ◽  
Potato Common Scab

A novel strain of Streptomyces (named DS3024) was isolated from a potato field in Michigan in 2006. The taxonomy of the organism was determined by morphology, biochemistry, and genetic analysis. Analysis of the 16S ribosomal RNA gene sequence indicated that the organism was most similar to an isolate of Streptomyces sp., ME02-6979.3a, which is not pathogenic to potato tubers but is distinct from other known pathogenic Streptomyces spp. Strain DS3024 has genes that encode thaxtomin synthetase (txtAB), which is required for pathogenicity and virulence, and tomatinase (tomA), which is a common marker for many pathogenic Streptomyces spp. However, the nec1 gene (associated with virulence in most pathogenic Streptomyces spp.) was not detected. The new strain was capable of growth at pH 4.5, caused necrosis on potato tuber slices, and produced thaxtomin A. In greenhouse experiments, DS3024 caused scab symptoms on potato tubers similar to those caused by Streptomyces scabies on tubers of potato cv. Atlantic, which is scab susceptible. We propose that DS3024 is a new strain of Streptomyces capable of causing common scab on potato tubers. The prevalence of this strain of Streptomyces in potato-producing areas in the north-central United States has not been determined.

scholarly journals Microbial Communities Associated with Potato Common Scab-Suppressive Soil Determined by Pyrosequencing Analyses

Plant Disease ◽  
2012 ◽  
Vol 96 (5) ◽  
pp. 718-725 ◽  
Author(s):  
Noah Rosenzweig ◽  
James M. Tiedje ◽  
John F. Quensen ◽  
Qingxiao Meng ◽  
Jianjun J. Hao
Keyword(s):  
Microbial Communities ◽  
Common Scab ◽  
Disease Suppression ◽  
Rrna Gene ◽  
Suppressive Soil ◽  
Streptomyces Spp ◽  
Potato Common Scab ◽  
Order Of Magnitude ◽  
Disease Suppressive Soil ◽  
Conducive Soil

Potato common scab, caused by Streptomyces spp., is an annual production problem for potato growers, and not effectively controlled by current methods. A field with naturally occurring common scab suppression has been identified in Michigan, and confirmed to have a biological basis for this disease suppression. This field and an adjacent scab nursery conducive to disease were studied using pyrosequencing to compare the two microbial communities. Total DNA was extracted from both the disease-conducive and -suppressive soils. A phylogenetically taxon-informative region of the 16S rRNA gene was used to establish operational taxonomic units (OTUs) to characterize bacterial community richness and diversity. In total, 1,124 OTUs were detected and 565 OTUs (10% dissimilarity) were identified in disease-conducive soil and 859 in disease-suppressive soil, including 300 shared both between sites. Common phyla based on relative sequence abundance were Acidobacteria, Proteobacteria, and Firmicutes. Sequences of Lysobacter were found in significantly higher numbers in the disease-suppressive soil, as were sequences of group 4 and group 6 Acidobacteria. The relative abundance of sequences identified as the genus Bacillus was significantly higher by an order of magnitude in the disease-conducive soil.

Quantitative relationships among thaxtomin A production, potato scab severity, and fatty acid composition in Streptomyces

1998 ◽  
Vol 44 (8) ◽  
pp. 768-776 ◽  
Author(s):  
Linda L Kinkel ◽  
John H Bowers ◽  
Kyoko Shimizu ◽  
Eric C Neeno-Eckwall ◽  
Janet L Schottel
Keyword(s):  
Fatty Acid ◽  
Common Scab ◽  
Potato Scab ◽  
Quantitative Information ◽  
Fatty Acid Profiles ◽  
Field Isolates ◽  
Thaxtomin A ◽  
Streptomyces Spp ◽  
Potato Common Scab ◽  
Fatty Acid Data

Thaxtomin A production in culture, potato common scab severity (percentage of tuber surface infected or number of lesions per tuber), and fatty acid profiles were determined for 78 Streptomyces isolates. Only pathogenic Streptomyces spp. (n = 17) produced thaxtomin A in culture. Thaxtomin A production in culture (µg/mL) was significantly positively correlated with the percentage of tuber surface infected (R = 0.60; p = 0.017) but not with the number of lesions per tuber (R = 0.37; p = 0.17). An increase of 1 µg/mL in thaxtomin A production corresponded to an 11% increase in disease severity (percentage of tuber surface infected). The data indicate that quantitative information on the ability of a particular pathogen isolate or population to produce thaxtomin A may be critical to understanding and predicting the disease potential of that population. Using cluster analysis of fatty acid data, 94% of 67 unknown field isolates grouped with other field isolates having the same pathogenicity (plus or minus).Key words: thaxtomin A, phytotoxin, potato scab.

scholarly journals Repeated Applications of a Nonpathogenic Streptomyces Strain Enhance Development of Suppressiveness to Potato Common Scab

Plant Disease ◽  
2017 ◽  
Vol 101 (1) ◽  
pp. 224-232 ◽  
Author(s):  
Lea H. Hiltunen ◽  
Jani Kelloniemi ◽  
Jari P. T. Valkonen
Keyword(s):  
Common Scab ◽  
Disease Incidence ◽  
Potato Cultivar ◽  
Disease Suppression ◽  
Streptomyces Strain ◽  
Streptomyces Spp ◽  
Potato Common Scab ◽  
Repeated Applications ◽  
Disease Pressure

Potato common scab caused by several Streptomyces spp. is an important disease with no effective methods of control. Suppressiveness against common scab can develop in soil as a result of long-term potato monoculture and has been associated with nonpathogenic Streptomyces spp. To determine whether the development of scab suppressiveness could be enhanced, the effect of repeated applications of an antagonistic Streptomyces strain on common scab was investigated in a long-term field trial over 5 years. Streptomyces strain 272 applied annually at planting consistently suppressed development of common scab symptoms. On scab-susceptible potato cultivar Bintje, strain 272 reduced disease severity, on average, by 43%; whereas, on the scab-tolerant Nicola, the strain reduced both disease incidence and severity by 43 and 59%, respectively. Regardless of disease pressure, the combined use of strain 272 and the tolerant cultivar reduced the scab coverage to a negligible level. After a single application of strain 272, efficient disease suppression did not persist in the soil to the following growing season. However, when strain 272 was applied in three or more consecutive years, the soil remained suppressive to scab for at least 2 years beyond the last application, suggesting that, with repeated applications, it may be possible to enhance development of scab suppression in soil.

scholarly journals Rice Bran Amendment Suppresses Potato Common Scab by Increasing Antagonistic Bacterial Community Levels in the Rhizosphere

2016 ◽  
Vol 106 (7) ◽  
pp. 719-728 ◽  
Author(s):  
Tsuyoshi Tomihama ◽  
Yatsuka Nishi ◽  
Kiyofumi Mori ◽  
Tsukasa Shirao ◽  
Toshiya Iida ◽  
...  
Keyword(s):  
Rice Bran ◽  
Common Scab ◽  
Cultural Practices ◽  
Potato Production ◽  
Amplicon Sequencing ◽  
Underlying Disease ◽  
Antagonistic Activity ◽  
Disease Suppression ◽  
Streptomyces Spp ◽  
Potato Common Scab

Potato common scab (PCS), caused by pathogenic Streptomyces spp., is a serious disease in potato production worldwide. Cultural practices, such as optimizing the soil pH and irrigation, are recommended but it is often difficult to establish stable disease reductions using these methods. Traditionally, local farmers in southwest Japan have amended soils with rice bran (RB) to suppress PCS. However, the scientific mechanism underlying disease suppression by RB has not been elucidated. The present study showed that RB amendment reduced PCS by repressing the pathogenic Streptomyces population in young tubers. Amplicon sequencing analyses of 16S ribosomal RNA genes from the rhizosphere microbiome revealed that RB amendment dramatically changed bacterial composition and led to an increase in the relative abundance of gram-positive bacteria such as Streptomyces spp., and this was negatively correlated with PCS disease severity. Most actinomycete isolates derived from the RB-amended soil showed antagonistic activity against pathogenic Streptomyces scabiei and S. turgidiscabies on R2A medium. Some of the Streptomyces isolates suppressed PCS when they were inoculated onto potato plants in a field experiment. These results suggest that RB amendment increases the levels of antagonistic bacteria against PCS pathogens in the potato rhizosphere.

scholarly journals Culture-Based Assessment of Microbial Communities in Soil Suppressive to Potato Common Scab

Plant Disease ◽  
2012 ◽  
Vol 96 (5) ◽  
pp. 712-717 ◽  
Author(s):  
Qingxiao Meng ◽  
Jingfang Yin ◽  
Noah Rosenzweig ◽  
David Douches ◽  
Jianjun J. Hao
Keyword(s):  
Microbial Communities ◽  
Common Scab ◽  
Fluorescent Pseudomonads ◽  
Polymorphism Analysis ◽  
Streptomyces Spp ◽  
Restriction Fragment Polymorphism ◽  
Potato Common Scab ◽  
Total Fungi ◽  
Total Bacteria ◽  
Conducive Soil

A field in East Lansing, MI, showed a decline of potato common scab compared with an adjacent potato field. To confirm that the decline was due to biological factors, the soil was assayed. In the greenhouse, putative common-scab-suppressive soil (SS) was either treated with various temperatures or mixed with autoclaved SS at various ratios. Pathogenic Streptomyces scabies was incorporated into the treated soil at 106 CFU/cm3 of soil, followed by planting of either potato or radish. Disease severity was negatively correlated with the percentage of SS in the mixture and positively correlated with temperature above 60°C. The soil was screened for four groups of potential antagonists (general bacteria, streptomycetes, fluorescent pseudomonads, and bacilli) pairing in culture with S. scabies. The frequency of antagonistic bacteria in SS was higher than common-scab-conducive soil (CS) in all four groups but only pseudomonads and streptomycetes were significantly higher. The population of pathogenic Streptomyces spp. in the rhizosphere of CS was significantly higher than SS. Dilution plating of CS and SS samples showed no clear trends or differences in populations of total fungi, total bacteria, streptomycetes, fluorescent pseudomonads, and bacilli but terminal restriction fragment polymorphism analysis revealed two distinct microbial communities were present in SS and CS.

scholarly journals Determination of antimicrobial resistance to extended-spectrum cephalosporin, quinolones, and vancomycin in selected human enteric pathogens from Prince Edward Island, Canada

2018 ◽  
Vol 64 (7) ◽  
pp. 473-482
Author(s):  
Babafela Awosile ◽  
Gregory German ◽  
Juan Carlos Rodriguez-Lecompte ◽  
Matthew E. Saab ◽  
Luke C. Heider ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Prince Edward Island ◽  
Carbapenem Resistance ◽  
Chain Reactions ◽  
E Coli ◽  
Polymerase Chain Reactions ◽  
Extended Spectrum ◽  
Enterococcus Spp ◽  
Polymerase Chain

The aim of this study was to determine the frequency of fecal carriage of vancomycin-resistant Enterococcus spp. and Escherichia coli with reduced susceptibilities to extended-spectrum cephalosporins (ESCs) and quinolones in humans on Prince Edward Island, Canada. Convenience fecal samples from individuals on Prince Edward Island were screened phenotypically using selective culture and genotypically using multiplex polymerase chain reactions to detect E. coli and Enterococcus spp. resistant to critically important antimicrobials. Twenty-six (5.3%) of 489 individuals had E. coli with reduced susceptibility to ESCs. Twenty-five (96.2%) of the 26 isolates harbored blaTEM, 18 (69.2%) harbored blaCMY-2, 16 (61.5%) harbored blaCTX-M groups, 2 (7.7%) harbored blaSHV genes. None of the ESC-resistant E. coli was positive for carbapenem resistance. Twenty-one (8.3%) of 253 individuals had E. coli isolates with reduced quinolone susceptibility. All 21 isolates were positive for at least 1 qnr gene, with 3 (14.3%) isolates positive for qnrB, 5 (23.8%) positive for qnrS, and 13 (61.9%) positive for both qnrB and qnrS genes. All the enterococci isolates were vancomycin-susceptible. Higher susceptibility to the critically important antimicrobials was found in this study. This study can serve as a baseline for future antimicrobial resistance surveillance within this region.

scholarly journals Potato berry bioassay to detect Streptomyces spp. that produce phytotoxic thaxtomin A and cause potato common scab.

2006 ◽  
Vol 72 (3) ◽  
pp. 135-142 ◽  
Author(s):  
S. NAITO ◽  
M. MAEDA ◽  
S. TANI ◽  
D. IMAJI ◽  
S. AKINO ◽  
...  
Keyword(s):  
Common Scab ◽  
Thaxtomin A ◽  
Streptomyces Spp ◽  
Potato Common Scab
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