(Smith) is a recently emerged plant pathogen that causes severe economic losses in cucurbit crops in temperate Eastern North America. is xylem restricted, and virulence is thought to be related to Exopolysaccharides (EPS) and biofilm formation, which occlude the passage of sap in xylem vessels and causes systemic wilt. However, the role of EPS and biofilm formation, and their contribution to disease in relation to other virulence loci are unknown.
View Article and Find Full Text PDFPremise: Quantifying how closely related plant species differ in susceptibility to insect herbivory is important for understanding the variation in evolutionary pressures on plant functional traits. However, empirically measuring in situ variation in herbivory spanning the geographic range of a plant-insect complex is logistically difficult. Recently, new methods have been developed using herbarium specimens to investigate patterns in plant-insect symbioses across large geographic scales.
View Article and Find Full Text PDFHumans have relied on sourdough starter microbial communities to make leavened bread for thousands of years, but only a small fraction of global sourdough biodiversity has been characterized. Working with a community-scientist network of bread bakers, we determined the microbial diversity of 500 sourdough starters from four continents. In sharp contrast with widespread assumptions, we found little evidence for biogeographic patterns in starter communities.
View Article and Find Full Text PDFErwinia tracheiphila is a bacterial plant pathogen that causes a fatal wilt infection in some cucurbit crop plants. Wilt symptoms are thought to be caused by systemic bacterial colonization through xylem that impedes sap flow. However, the genetic determinants of within-plant movement are unknown for this pathogen species.
View Article and Find Full Text PDFPlants must rearrange the network of complex carbohydrates in their cell walls during normal growth and development. To accomplish this, all plants depend on proteins called expansins that nonenzymatically loosen noncovalent bonding between cellulose microfibrils. Surprisingly, expansin genes have more recently been found in some bacteria and microbial eukaryotes, where their biological functions are largely unknown.
View Article and Find Full Text PDFMilpas are rain-fed agroecosystems involving domesticated, semi-domesticated and tolerated plant species that combine maize with a large variety of other crop, tree or shrub species. Milpas are low input and low-tillage, yet highly productive agroecosystems, which have been maintained over millennia in indigenous communities in Mexico and other countries in Central America. Thus, milpas may retain ancient plant-microorganisms interactions, which could have been lost in modern high-tillage monocultures with large agrochemical input.
View Article and Find Full Text PDFMicrobiol Resour Announc
November 2018
Erwinia tracheiphila is a bacterial plant pathogen emerging in eastern North America. To aid in understanding genetic variation within E. tracheiphila, here we sequence the first reference genome of an infected muskmelon (Cucumis melo).
View Article and Find Full Text PDFis the causal agent of bacterial wilt of cucurbits, an economically important phytopathogen affecting an economically important phytopathogen affecting few cultivated Cucurbitaceae few cultivated Cucurbitaceae host plant species in temperate eastern North America. However, essentially nothing is known about population structure or genetic diversity. To address this shortcoming, a representative collection of 88 isolates was gathered from throughout its geographic range, and their genomes were sequenced.
View Article and Find Full Text PDFAdv Virus Res
November 2018
Plant viruses possess adaptations for facilitating acquisition, retention, and inoculation by vectors. Until recently, it was hypothesized that these adaptations are limited to virus proteins that enable virions to bind to vector mouthparts or invade their internal tissues. However, increasing evidence suggests that viruses can also manipulate host plant phenotypes and vector behaviors in ways that enhance their own transmission.
View Article and Find Full Text PDFis the causal agent of bacterial wilt of cucurbits. Here, we report the genome sequence of the temperate phage EtG, which was isolated from an -infected cucumber plant. Phage EtG has a linear 30,413-bp double-stranded DNA genome with cohesive ends and 45 predicted open reading frames.
View Article and Find Full Text PDFPlant-associated soil microbes are important mediators of plant defence responses to diverse above-ground pathogen and insect challengers. For example, closely related strains of beneficial rhizosphere Pseudomonas spp. can induce systemic resistance (ISR), systemic susceptibility (ISS) or neither against the bacterial foliar pathogen Pseudomonas syringae pv.
View Article and Find Full Text PDFModern industrial agriculture depends on high-density cultivation of genetically similar crop plants, creating favorable conditions for the emergence of novel pathogens with increased fitness in managed compared with ecologically intact settings. Here, we present the genome sequence of six strains of the cucurbit bacterial wilt pathogen Erwinia tracheiphila (Enterobacteriaceae) isolated from infected squash plants in New York, Pennsylvania, Kentucky, and Michigan. These genomes exhibit a high proportion of recent horizontal gene acquisitions, invasion and remarkable amplification of mobile genetic elements, and pseudogenization of approximately 20% of the coding sequences.
View Article and Find Full Text PDFErwinia tracheiphila is one of the most economically important pathogens of cucumbers, melons, squashes, pumpkins, and gourds in the northeastern and midwestern United States, yet its molecular pathology remains uninvestigated. Here, we report the first draft genome sequence of an E. tracheiphila strain isolated from an infected wild gourd (Cucurbita pepo subsp.
View Article and Find Full Text PDFBacterial wilt threatens cucurbit crop production in the Midwestern and Northeastern United States. The pathogen, Erwinia tracheiphila, is a xylem-limited bacterium that affects most commercially important cucurbit species, including muskmelon, cucumber, and squash. Bacterial wilt is transmitted and overwintered by striped and spotted cucumber beetles.
View Article and Find Full Text PDFBoth biotic and abiotic stressors can elicit broad-spectrum plant resistance against subsequent pathogen challenges. However, we currently have little understanding of how such effects influence broader aspects of disease ecology and epidemiology in natural environments where plants interact with multiple antagonists simultaneously. In previous work, we have shown that healthy wild gourd plants (Cucurbita pepo ssp.
View Article and Find Full Text PDFPathogens can alter host phenotypes in ways that influence interactions between hosts and other organisms, including insect disease vectors. Such effects have implications for pathogen transmission, as well as host exposure to secondary pathogens, but are not well studied in natural systems, particularly for plant pathogens. Here, we report that the beetle-transmitted bacterial pathogen Erwinia tracheiphila - which causes a fatal wilt disease - alters the foliar and floral volatile emissions of its host (wild gourd, Cucurbita pepo ssp.
View Article and Find Full Text PDFBackground: This article presents an evidence-supported clinical pathway for dry skin prevention and treatment.
Objective: The development of the pathway involved the following: a literature review was conducted and demonstrated that literature on dry skin is scarce. To compensate for the gap in the available literature, a modified Delphi method was used to collect information on prevention and treatment practice through a panel, which included 10 selected dermatologists who currently provide medical care for dermatology patients in Ontario.
Cytokines play a role in the immunopathological and molecular mechanisms of sulfonamide-induced hypersensitivity reactions (HSRs). The objective of this study was to analyze the reliability and correlation between the clinical symptoms observed in affected patients (n = 86) because of a sulfonamide-induced HSR and their lymphocyte toxicity assay (LTA) values. Another goal was to determine the cytokine secretion in the patient's sera and their expression in the peripheral blood mononuclear cells (PBMCs) and to explore whether a correlation exists among positive LTA score, cytokine levels, and HSR occurrence.
View Article and Find Full Text PDFAm J Clin Dermatol
January 2004
While it would be impossible for any dermatologist to remember all potential drug interactions, knowledge of the mechanisms of drug interactions can help reduce the risk of serious adverse outcomes. Most drugs are associated with interactions but the majority do not produce significant outcomes. Dealing with drug interactions is a challenge in all clinical practice, including dermatology.
View Article and Find Full Text PDFClin Rev Allergy Immunol
June 2003
Idiosyncratic reactions can affect many different organ systems, either as -an isolated event (e.g., hepatitis) or as part of a syndrome (e.
View Article and Find Full Text PDFObjective: To evaluate cross reactivity between sulfonamide antimicrobials and celecoxib in patients with histories of allergies to sulfonamide antimicrobials.
Methods: Immunocompetent patients with a history of sulfonamide antimicrobial allergy who were being considered for therapy with celecoxib were prospectively enrolled. Sulfamethoxazole and trimethoprim skin prick and intradermal testing and/or an in vitro lymphocyte toxicity assay were performed.
Unlabelled: The two major concerns in drug safety are adverse drug reactions and drug interactions. When multiple drug therapies are prescribed, drug interactions become an important consideration for patients and physicians. The life of a drug is reviewed with emphasis on absorption, distribution, metabolism, and excretion.
View Article and Find Full Text PDFCan J Clin Pharmacol
October 2002
Objective: To describe a patient who developed a widespread skin eruption following the use of two Chinese herbal medications, Fang Feng Tong Sheng Wan and Bi Yan Pian.
Case Summary: A 34-year-old man developed widespread erythematous papules that coalesced into plaques after five days of therapy with two Chinese herbal preparations. There was no lymphadenopathy or hepatosplenomegaly, and the patient denied any fever, chills or malaise.