scholarly journals First Report of Virulence in Argentine Populations of Puccinia sorghi to Rp Resistance Genes in Corn

Plant Disease ◽  
2000 ◽  
Vol 84 (8) ◽  
pp. 921-921 ◽  
Author(s):  
M. Gonzalez
Keyword(s):  
Specific Resistance ◽  
Infection Type ◽  
Wide Spectrum ◽  
Leaf Tissue ◽  
The United States ◽  
Santa Fe ◽  
Puccinia Sorghi ◽  
Rust Severity ◽  
Infection Types

Common rust (Puccinia sorghi) is a chronic disease of corn (Zea mays L.) in Argentina. Factors contributing to the disease include relatively susceptible germ plasm, planting late in the season, and variability within populations of P. sorghi. Several genes for race-specific resistance to common rust (i.e., Rp genes) were identified based on virulence in populations of P. sorghi in the United States (1). The objective of this research was to examine the virulence of Argentine populations of P. sorghi against 24 alleles at four Rp loci that condition race-specific resistance to common rust. Rp genes in an R168-inbred background were planted in trials at two locations in the central corn belt of Argentina. In the 1996-97, 1997-98, and 1999-2000 seasons, trials were planted in Pergamino (Province of Buenos Aires). In the 1998-99 season, the trial was planted in Zavalla (Province of Santa Fe). Plants were exposed to naturally occurring local populations of P. sorghi. About 3 to 4 weeks after anthesis, rust severity (percentage of leaf tissue with uredinia) and infection type were rated for all plants. Four categories of infection type were: 1—no rust, necrotic or chlorotic flecks, 2—small uredinia with or without necrotic flecks, 3—large uredinia, and 4—large uredinia with banding. Three lines with Rp genes (Rp1-N, Rp3-A, and Rp3-C) had infection type 1 with necrotic flecks and severity of 0%. Lines with other Rp genes (Rp1-A, Rp1-B, Rp1-C, Rp1-D, Rp1-E, Rp1-F, Rp1-G, Rp1-H, Rp1-I, Rp1-J, Rp1-K, Rp1-M, Rp1-N, Rp3-A, Rp3-B, Rp3-C, Rp3-D, Rp3-E, Rp4-A, Rp4-B, and Rp5) had infection types 2 to 4 and severity ranged from 5 to 35%. Severity was affected by the virulence of the populations and the environmental conditions in each trial. These results are evidence of a wide spectrum of virulence in P. sorghi populations in Argentina. Reference: (1) W. Hagan and A. Hooker. Phytopathology 55:193, 1965.

scholarly journals A Computer Program to Improve the Efficiency and Accuracy of Postulating Race-Specific Resistance Genes

Plant Disease ◽  
2004 ◽  
Vol 88 (5) ◽  
pp. 545-549 ◽  
Author(s):  
Yeshi A. Wamishe ◽  
Kevin C. Thompson ◽  
Eugene A. Milus
Keyword(s):  
Computer Program ◽  
Resistance Genes ◽  
Specific Resistance ◽  
Infection Type ◽  
Puccinia Triticina ◽  
Lr Genes ◽  
Soft Red Winter Wheat ◽  
Gene Concept ◽  
Infection Types ◽  
Gene For Gene

Gene postulation has been the most widely used technique to determine the presence of particular rust resistance genes in lines of small grains. It applies the principles of gene-for-gene specificity to determine the most probable race-specific resistance genes present in host lines. As the numbers of lines, resistance genes, and races increase, postulation based on visual comparisons of infection types becomes more complex and laborious, and errors may occur. A computer program was developed to facilitate identification of race-specific leaf rust (Lr) genes in wheat (Triticum aestivum). Seedlings of 116 contemporary lines of soft red winter wheat and 24 Thatcher isolines (each Thatcher isoline with a single Lr gene) were inoculated with 22 races of Puccinia triticina. Infection types were recorded on the standard 0 to 4 scale where infection types 3 and 4 were considered high (line was susceptible; race was virulent) and others were low (line was resistant; race was avirulent). Based on the gene-for-gene concept, lines susceptible to a particular race cannot have an Lr gene for which the race is avirulent. For each line, step 1 of the program summarized results from races that were virulent on the line to definitively exclude Lr genes from the line, and this exclusion resulted in a relatively short list of Lr genes that could be present. Step 2 of the program utilized data from races that were avirulent on the line, and the output listed the low infection types produced on the line and the isolines with Lr genes that were not excluded in step 1. Of these Lr genes, a gene was considered present if the low infection type produced on the line by one or more races matched the low infection type on the corresponding isoline. Otherwise, the gene was considered possibly present. Epistatic effects of one or more Lr genes prevented definitive inclusion or exclusion of genes considered possibly present. If the low infection type produced on the line was lower than that on any of the isolines listed in step 2, then the line was considered to have an unidentified Lr gene; i.e., a gene that was not in the set of 24 isolines. This program facilitated the objective and accurate postulation of Lr genes and could be adapted to other host-pathogen systems.

scholarly journals 1345. Comparative Activity of Plazomicin and Other Aminoglycosides Against Enterobacteriaceae Isolates From Various Infection Sources From Hospitalized Patients in the United States

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S411-S411 ◽  
Author(s):  
Mariana Castanheira ◽  
Jennifer M Streit ◽  
Alisa W Serio ◽  
Kevin M Krause ◽  
Robert K Flamm
Keyword(s):  
United States ◽  
Infection Type ◽  
Treatment Options ◽  
Bloodstream Infections ◽  
The United States ◽  
Hospitalized Patients ◽  
Research Support ◽  
Infection Source ◽  
Infection Types ◽  
Tract Infections

Abstract Background Plazomicin is a next-generation aminoglycoside that is currently under review at the United States Food and Drug Administration for complicated urinary tract infections (cUTIs), including acute pyelonephritis, and bloodstream infections (BSIs) due to certain Enterobacteriaceae (ENT) in patients who have limited or no alternative treatment options. We evaluated the activity of plazomicin and aminoglycosides against ENT isolates collected in US hospitals during 2014 to 2017 by site of infection. Methods A total of 8,510 ENT isolates were collected from BSIs (2,133), pneumonia in hospitalized patients (PIHP; 1,826), skin and skin structure infections (SSSIs; 1,155), intra-abdominal infections (IAIs; 731), UTIs (2,508), and other or unknown infection sites (others; 157) in 71 US hospitals during 2014 to 2017. Isolates were susceptibility (S) tested by reference broth microdilution methods and results were interpreted using CLSI breakpoints. Results Plazomicin (MIC50/90 ranges, 0.25–0.5/1–2 µg/mL) inhibited 98.8–99.9% of the ENT isolates at ≤4 µg/mL across all infection types (figure). At ≤4 µg/mL, plazomicin inhibited 93.8–100% of the carbapenem-resistant ENT (CRE) isolates stratified by infection type. The S rates for amikacin ranged from 98.7% to 99.7% against ENT isolates overall. However, amikacin S rates for CRE ranged from 53.1% for UTI to 100% for IAI isolates. Gentamicin (89.2–93.6%S) and tobramycin (88.8–94.3%S) were slightly less active than plazomicin and amikacin against the ENT isolates stratified by infection source. Gentamicin S rates against CRE isolates ranged from 43.8% to 66.7% while tobramycin inhibited <45% of the CRE isolates from the different infection sources. Conclusion The activity of plazomicin and amikacin was similar against ENT isolates from US hospitals and did not vary by infection type; however, amikacin activity against CRE isolates varied by infection source while plazomicin remained active against CRE isolates regardless of infection source. These results highlight the potential role of plazomicin for treating serious infections caused by CRE. This project was partially funded under BARDA Contract No. HHSO100201000046C. Disclosures M. Castanheira, Achaogen: Research Contractor, Research support. J. M. Streit, Achaogen: Research Contractor, Research support. A. W. Serio, Achaogen: Employee, Salary. K. M. Krause, Achaogen: Employee, Salary. R. K. Flamm, Achaogen: Research Contractor, Research support.

scholarly journals Virulence in Puccinia recondita f. sp. tritici Isolates from Canada to Genes for Adult-Plant Resistance to Wheat Leaf Rust

Plant Disease ◽  
1997 ◽  
Vol 81 (3) ◽  
pp. 267-271 ◽  
Author(s):  
J. A. Kolmer
Keyword(s):  
Leaf Rust ◽  
Resistance Genes ◽  
Infection Type ◽  
Leaf Rust Resistance ◽  
Seedling Resistance ◽  
High Infection ◽  
Rust Severity ◽  
Lower Infection ◽  
Infection Types ◽  
Adult Plants

Sixty-seven isolates of Puccinia recondita f. sp. tritici collected in Canada were tested for virulence to adult plants of Thatcher near-isogenic wheat lines with leaf rust resistance genes Lr13, Lr22a, Lr34, Lr35, and Lr13 and Lr34 combined. All of the isolates had low infection type to the Thatcher lines with Lr22a and Lr35. All isolates had lower infection type and lower rust severity on the Thatcher line with Lr34 compared with Thatcher. The isolates were polymorphic for virulence to the Thatcher line with Lr13; many isolates were completely virulent to this line, and other isolates produced very low or intermediate avirulent infection type. On the Thatcher line with Lr13 and Lr34 combined, many isolates had infection type and rust severity similar to the Thatcher line with Lr34, while other isolates had lower infection type and rust severity compared with the single-gene lines with Lr13 or Lr34. Fifteen isolates with low, intermediate, and high infection type to adult plants with Lr13 were tested for infection type on seedling plants of the Thatcher lines with resistance genes Lr13, Lr22a, Lr34, Lr35, and Lr37, and on Thatcher lines with Lr13 paired with seedling resistance genes. Most isolates were completely virulent to seedling plants with Lr13 and Lr22a. Plants with Lr37 expressed seedling resistance to all isolates tested. Seedling plants with Lr34 had lower infection types to all isolates compared with Thatcher. Seedlings with Lr35 had high infection types to most isolates, with varying amounts of chlorosis. The Thatcher lines with Lr13 plus seedling resistance genes were most resistant to the isolates that had very low infection types on adult plants with Lr13 and intermediate infection types on plants with seedling resistance genes. Genes Lr22a, Lr35, and Lr37 offer additional sources of highly effective leaf rust resistance in wheat.

scholarly journals First Report of a Leaf Spot of Barley Caused by Drechslera gigantea in Uruguay

Plant Disease ◽  
2003 ◽  
Vol 87 (1) ◽  
pp. 99-99 ◽  
Author(s):  
F. Gamba ◽  
A. Tekauz
Keyword(s):  
Infection Type ◽  
Aqueous Suspension ◽  
Leaf Tissue ◽  
Lesion Size ◽  
Intermediate Phenotype ◽  
Dark Cycle ◽  
First Report ◽  
Intermediate Phenotypes ◽  
Infection Types ◽  
Moderately Resistant

Barley (Hordeum vulgare), an important crop in Uruguay, is vulnerable to several foliar diseases. In early November 2001, leaves displaying unusual lesions were observed in a commercial barley crop and research plots in the Paysandu District of western Uruguay. Lesions were small, elliptical, tan-colored to necrotic, approximately 4 × 1 mm, and had a narrow, dark brown margin. Older lesions occasionally were surrounded by a narrow (0.5 mm wide) chlorotic halo and some lesions had a white dot in the center. Sections of affected leaf tissue were placed in a moist chamber at 20°C with a 12 h light/dark cycle for 4 days to promote sporulation of a putative fungal pathogen. Conidia subsequently developing from infected tissue were large (250 to 325 μm long) and were identified as Drechslera gigantea (2). Koch's postulates were verified by growing the fungus on 10% V8 juice agar, and the aqueous suspension was adjusted to 3 × 104conidia per ml. Lower concentrations were tested but they were not great enough to prevent disease escape. A De Vilbiss atomizer was used to spray 2-week-old barley seedlings kept in a growth chamber at 18°C with a 17/7 h light/dark cycle. Inoculated plants were kept in the dark for 24 h at 100% relative humidity and then returned to the previous conditions. Twenty seedlings of each of two Canadian, one American, and eight barley genotypes from Uruguay were used for the study. The experiment was conducted twice including water controls each time. Small lesions appeared on all leaves of all inoculated plants on 10 cultivars 4 days after inoculation, and after 9 days they were fully developed and visually the same as those on plants in the field. Control plants did not display symptoms. D. gigantea was reisolated from lesions on all diseased leaves. A 0 to 5 disease infection scale, based on lesion size, was developed for which infection types 0, 1, and 2 were considered as immune, resistant, and moderately resistant phenotypes, respectively, type 3 as an intermediate phenotype, and 4 and 5 as moderately susceptible and susceptible phenotypes, respectively. The most susceptible infection type was observed on ‘Dayman’ barley, the same cultivar in which the disease was first noted and from which the pathogen was isolated. Cv. Herta, once grown in western Canada, also was susceptible, whereas the cvs. Bowman (United States) and McGwire (Canada) were moderately resistant. Only one cultivar (Uruguay) did not show any symptoms. Several Uruguayan experimental barley lines exhibited moderately resistant or intermediate phenotypes. D. gigantea has been reported as causing an “eyespot” disease on grasses (2) and rice (1). Further studies with different inoculation protocols and host development stages as well as sampling of a broader range of barley germ plasm is needed to assess the current and potential impact of this fungus. To our knowledge, this is the first report of D. gigantea as a pathogen of barley in Uruguay, and possibly the first report of this species as a barley pathogen globally. References: (1) S.-W. Ahn. Plant Dis. 64:878, 1980. (2) C. Drechsler. J. Agric. Res. 24:641,1923.

INHERITANCE OF PATHOGENICITY AND UREDIOSPORE COLOR IN CROSSES BETWEEN PHYSIOLOGIC RACES OF OAT STEM RUST

1949 ◽  
Vol 27c (5) ◽  
pp. 203-217 ◽  
Author(s):  
T. Johnson
Keyword(s):  
Infection Type ◽  
Single Pair ◽  
Maternal Parent ◽  
Race 1 ◽  
Physiologic Races ◽  
Infection Types ◽  
Orange Color ◽  
Parent Race

In the F1 generation of crosses between physiologic races 7 (orange) and 11 (red) of Puccinia graminis Pers. var. Avenae Erikss. and Henn., the medium sized uredia (type 2 infection) formed by race 11 on the oat variety White Tartar were dominant to the large (type 4) uredia of race 7, and the small (type 1) uredia of race 7 on the variety Richland were dominant to the type 4 uredia formed by race 11. On the varieties Sevnothree and Joanette Strain, the F1 hybrids produced the same type of infection as did the "maternal" parent race, that is, hybrids from race 7 × race 11 crosses produced a type 4 infection like race 7, and reciprocal hybrids produced a type 1 infection like race 11. These facts led to the suggestion that the cytoplasm of the maternal parent race influenced the infection type of the F1 hybrid on these two oat varieties.A study of the F2 generation of the cross race 11 × race 7 showed that on the varieties White Tartar and Richland the dominant and recessive infection types appeared in a ratio of 9:7, which suggests that their inheritance is governed by two pairs of complementary genes. The distribution of physiologic races in F2 conforms to this assumption and indicates that the genes governing infection types on these two varieties associate at random to produce physiologic races 1, 11, 3, and 4. These races occurred in F2 in a ratio of 31: 20: 22: 12, as compared to an expected ratio of 27: 21: 21: 16. On the variety Sevnothree, 84 of 85 F2 cultures produced type 1 uredia, in this way resembling the maternal parent, race 1, and the maternal grandparent, race 11. One F2 culture, only produced the type 4 uredia characteristic of the paternal grandparent, race 7. It is concluded from this study, and from crosses between races 1 and 2, that the maternal (cytoplasmic) influence evidenced in the F1 generation persists m F2 and F3.In F1, the red urediospore color of race 11 was dominant to the orange color of race 7. The distribution in these two color classes in F2 and F3 suggests that the inheritance of urediospore color is governed by a single pair of genes.

scholarly journals C-Peptide as a Therapy for Type 1 Diabetes Mellitus

Biomedicines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 270
Author(s):  
Rachel L. Washburn ◽  
Karl Mueller ◽  
Gurvinder Kaur ◽  
Tanir Moreno ◽  
Naima Moustaid-Moussa ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Vascular Complications ◽  
The United States ◽  
Genetically Engineered ◽  
Therapeutic Effects ◽  
Pancreatic Islet Transplantation ◽  
C Peptide ◽  
Increased Risk

Diabetes mellitus (DM) is a complex metabolic disease affecting one-third of the United States population. It is characterized by hyperglycemia, where the hormone insulin is either not produced sufficiently or where there is a resistance to insulin. Patients with Type 1 DM (T1DM), in which the insulin-producing beta cells are destroyed by autoimmune mechanisms, have a significantly increased risk of developing life-threatening cardiovascular complications, even when exogenous insulin is administered. In fact, due to various factors such as limited blood glucose measurements and timing of insulin administration, only 37% of T1DM adults achieve normoglycemia. Furthermore, T1DM patients do not produce C-peptide, a cleavage product from insulin processing. C-peptide has potential therapeutic effects in vitro and in vivo on many complications of T1DM, such as peripheral neuropathy, atherosclerosis, and inflammation. Thus, delivery of C-peptide in conjunction with insulin through a pump, pancreatic islet transplantation, or genetically engineered Sertoli cells (an immune privileged cell type) may ameliorate many of the cardiovascular and vascular complications afflicting T1DM patients.

scholarly journals Fluctuations in the incidence of type 1 diabetes in the United States from 2001 to 2015: a longitudinal study

BMC Medicine ◽  
2017 ◽  
Vol 15 (1) ◽  
Author(s):  
Mary A. M. Rogers ◽  
Catherine Kim ◽  
Tanima Banerjee ◽  
Joyce M. Lee
Keyword(s):  
United States ◽  
Type 1 Diabetes ◽  
Longitudinal Study ◽  
The United States

scholarly journals Neurofibromatosis type 1 and chronic neurological conditions in the United States: an administrative claims analysis

2014 ◽  
Vol 17 (1) ◽  
pp. 36-42 ◽  
Author(s):  
Chinwe C. Madubata ◽  
Margaret A. Olsen ◽  
Dustin L. Stwalley ◽  
David H. Gutmann ◽  
Kimberly J. Johnson
Keyword(s):  
United States ◽  
Neurofibromatosis Type 1 ◽  
Neurofibromatosis Type ◽  
The United States ◽  
Administrative Claims ◽  
Claims Analysis ◽  
Neurological Conditions

scholarly journals Virulence of Oat Crown Rust in Brazil and Uruguay

Plant Disease ◽  
2005 ◽  
Vol 89 (8) ◽  
pp. 802-808 ◽  
Author(s):  
K. J. Leonard ◽  
J. A. Martinelli
Keyword(s):  
Avena Sativa ◽  
Western Siberia ◽  
Specific Resistance ◽  
The United States ◽  
Crown Rust ◽  
Puccinia Coronata ◽  
South American ◽  
Oat Crown Rust ◽  
High Virulence ◽  
Important Disease

Race-specific resistance to crown rust, the most important disease of oat (Avena sativa) in Bra-zil, often fails within a few years of use in Brazilian cultivars. Virulence of 144 isolates of Puccinia coronata from cultivated oat in Brazil in 1997 to 1999 and 36 isolates from Uruguay in 1994-95 and 1998 was tested on a set of 27 oat crown rust differentials lines, each with a different Pc gene for race-specific resistance. Frequencies of virulence and mean virulence complexity were compared among these five collections from Brazil and Uruguay as well as with mean virulence complexity for a collection of 17 isolates from cultivated oat in western Siberia in Russia. Virulence-avirulence for each of the 27 Pc genes was polymorphic in both Brazil and Uruguay. Virulence frequencies were similar for collections from Brazil in 1998 and 1999 and for the collection from Uruguay from 1998, but there were large differences between the 1997 collection and the 1998 and 1999 collections from Brazil. Mean virulence complexity in both Brazil and Uruguay was greater than reported in the United States and much greater than in the Russian collection of P. coronata. A large number of races of P. coronata were found, with no more than five isolates of any race found in a single year in Brazil or Uruguay. The high virulence complexity and great diversity of virulence polymorphisms in Brazil and Uruguay make it unlikely that race-specific resistance can be effective there even though the South American populations of P. coronata are apparently entirely asexual.

scholarly journals Vegetative Compatibility Groups of Fusarium oxysporum f. sp. lactucae from Lettuce

Plant Disease ◽  
2005 ◽  
Vol 89 (3) ◽  
pp. 237-240 ◽  
Author(s):  
Matias Pasquali ◽  
Flavia Dematheis ◽  
Giovanna Gilardi ◽  
Maria Lodovica Gullino ◽  
Angelo Garibaldi
Keyword(s):  
Fusarium Oxysporum ◽  
Genetic Relatedness ◽  
The United States ◽  
Vegetative Compatibility ◽  
Vegetative Compatibility Group ◽  
Vegetative Compatibility Groups ◽  
Compatibility Group ◽  
Race 1

Fusarium oxysporum f. sp. lactucae, the causal agent of Fusarium wilt of lettuce, has been reported in three continents in the last 10 years. Forty-seven isolates obtained from infected plants and seed in Italy, the United States, Japan, and Taiwan were evaluated for pathogenicity and vegetative compatibility. Chlorate-resistant, nitrate-nonutilizing mutants were used to determine genetic relatedness among isolates from different locations. Using the vegetative compatibility group (VCG) approach, all Italian and American isolates, type 2 Taiwanese isolates, and a Japanese race 1 were assigned to the major VCG 0300. Taiwanese isolates type 1 were assigned to VCG 0301. The hypothesis that propagules of Fusarium oxysporum f. sp. lactucae that caused epidemics on lettuce in 2001-02 in Italian fields might have spread via import and use of contaminated seeds is discussed.

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