scholarly journals Signs ofBacillus thuringiensis(Bacillales: Bacillaceae) Infection inMyzus persicae(Hemiptera: Aphididae): Koch's Postulates

2015 ◽  
Vol 98 (2) ◽  
pp. 799-802 ◽  
Author(s):  
Mary Carmen Torres-Quintero ◽  
Guadalupe Peña-Chora ◽  
Víctor Manuel Hernández-Velázquez ◽  
Iván Arenas-Sosa
Keyword(s):  
Koch’S Postulates ◽  
Ofbacillus Thuringiensis ◽  
Koch's Postulates

First Report of Pathogenicity of Fusarium sporotrichioides and Fusarium acuminatum on Sunflowers in the United States

2010 ◽  
Vol 11 (1) ◽  
pp. 42 ◽  
Author(s):  
F. Mathew ◽  
B. Kirkeide ◽  
T. Gulya ◽  
S. Markell
Keyword(s):  
United States ◽  
Helianthus Annuus ◽  
The United States ◽  
Fusarium Sporotrichioides ◽  
Charcoal Rot ◽  
Koch’S Postulates ◽  
First Report ◽  
Fusarium Acuminatum ◽  
Helianthus Annuus L ◽  
Koch's Postulates

Widespread infection of charcoal rot was observed in a commercial sunflower field in Minnesota in September 2009. Based on morphology, isolates were identified as F. sporotrichioides and F. acuminatum. Koch's postulates demonstrated pathogencity of both species. To our knowledge, this is the first report of F. sporotrichoides and F. acuminatum causing disease on Helianthus annuus L. in the United States. Accepted for publication 23 August 2010. Published 15 September 2010.

scholarly journals Cancer stem cells: Beyond Koch’s postulates

2009 ◽  
Vol 278 (1) ◽  
pp. 3-8 ◽  
Author(s):  
Emmanuel Garcion ◽  
Philippe Naveilhan ◽  
François Berger ◽  
Didier Wion
Keyword(s):  
Stem Cells ◽  
Cancer Stem Cells ◽  
Koch’S Postulates ◽  
Koch's Postulates

Koch’s Postulates

2008 ◽  
pp. 2093-2093
Author(s):  
Gary J. Puterka ◽  
D. Michael Glenn ◽  
George Hangay ◽  
Darryl Gwynne ◽  
John B. Heppner ◽  
...  
Keyword(s):  
Koch’S Postulates ◽  
Koch's Postulates

A Microbiology Teaching Lab: Using Koch's Postulates to Determine the Cause of “Peep Pox” in Marshmallow Peeps

2018 ◽  
Vol 80 (9) ◽  
pp. 676-679
Author(s):  
John L. Dahl ◽  
Wayne Gatlin
Keyword(s):  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
Cost Effective ◽  
Time Constraints ◽  
Limited Time ◽  
Koch’S Postulates ◽  
Ethical Concerns ◽  
Effective Time ◽  
Microbial Isolation ◽  
Koch's Postulates

Koch's postulates are regularly included in the lecture portion of microbiology courses, but rarely are they demonstrated in a microbiology teaching lab. This is understandable given the logistical challenges of undergraduates working with pathogenic bacteria, ethical concerns using animals, and limited time constraints of a weekly lab period. Here we present a cost-effective, time-friendly lab activity that demonstrates the principles of microbial isolation and infection assays that are part of fulfilling Koch's postulates. The disease is “peep pox” caused by a gelatinase-positive bacterial species hydrolyzing marshmallow peeps that proxy as infected animals.

scholarly journals First Report of Stemphylium botryosum Causing Leaf Blight of Kiwi in the Province Imathia, Northern Greece

Plant Disease ◽  
2008 ◽  
Vol 92 (4) ◽  
pp. 650-650 ◽  
Author(s):  
T. Thomidis ◽  
T. J. Michailides
Keyword(s):  
Apical Cell ◽  
Morphological Characteristics ◽  
Leaf Blight ◽  
Width Ratio ◽  
Northern Greece ◽  
Cell Width ◽  
Koch’S Postulates ◽  
First Report ◽  
Stemphylium Botryosum ◽  
Koch's Postulates

In Greece, kiwi (Actinidia deliciosa) is mostly found in the northern part of the country where approximately 440,000 ha are grown. In the summer of 2006, a Stemphylium sp. was frequently isolated from leaves of kiwi (cv. Hayward) grown in the province of Imathia. Symptomatic leaves were covered with irregular, necrotic, brown areas. Lesions had a distinct margin that, in some cases, covered a wide part of the diseased leaves. Intense symptoms were frequently observed and associated with defoliation. This Stemphylium sp. was consistently isolated from diseased leaves onto potato dextrose agar (PDA) after surface sterilization with 0.1% chlorine solution. On the basis of morphological characteristics of mycelia, dimensions (length 20 to 29 μm and width 14 to 21 μm) and mean length/width ratio (1.42 μm) of conidia, and width and apical cell width of condiophores, the fungus was identified as Stemphylium botryosum (Wallr.) (2,3) Koch's postulates were completed in the laboratory by inoculating leaves of kiwi (cv. Hayward) with an isolate of S. botryosum originated from a symptomatic leaf of a Hayward kiwi. Twenty leaves were surface sterilized by dipping them into 0.1% chlorine solution for 2 to 3 min, washing in sterile distilled water, and allowing them to dry in a laminar flow hood. A leaf was then placed into a petri plate containing a wet, sterilized paper towel. Inoculation was made by transferring a 5-mm-diameter mycelial disc from the margins of a 7-day-old culture onto the center of each leaf surface. Petri plates were closed and incubated at 25°C with 12 h of light for 6 days. Koch's postulates were satisfied when the same S. botryosum was reisolated from 100% of inoculated leaves that developed symptoms similar to those observed in the vineyards. Leaves inoculated with a PDA plug alone (with no S. botryosum) did not develop any symptoms. Previously, Alternaria alternata was reported as the causal agent of a leaf spot pathogen of kiwi (1,4). To our knowledge, this is the first report of the occurrence of S. botryosum causing leaf blight of kiwi in Greece and worldwide. This pathogen can cause a high level of defoliation in diseased plants. References: (1) L. Corazza et al. Plant Dis. 83:487, 1999. (2) M. B. Ellis. Dematiaceous Hyphomycetes. Mycology Institute. London, England, 1971. (3) E. G. Simmons. Mycologia 61:1, 1969. (4) C. Tsahouridou and C. C. Thanassoulopoulos. Plant Dis. 84:371, 2000

Viruses and autoimmune diseases—adapting Koch's postulates

2004 ◽  
Vol 3 (5) ◽  
pp. 355-361 ◽  
Author(s):  
A.M Denman ◽  
Bracha Rager-Zisman
Keyword(s):  
Autoimmune Diseases ◽  
Koch’S Postulates ◽  
Koch's Postulates

Adapting Koch's postulates

Science ◽  
2016 ◽  
Vol 351 (6270) ◽  
pp. 224-226 ◽  
Author(s):  
A. L. Byrd ◽  
J. A. Segre
Keyword(s):  
Koch’S Postulates ◽  
Koch's Postulates
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