Dr. Laura Ramos-Sepulveda

Assistant Professor, Microbiology, Mycology, and General Biology

Dr. Laura Ramos-Sepulveda

Contact Information


Office: Caputo 200A
Phone: 717- 871-7431

Office Hours

Comments: Office hours available by appointment.


B.S. in Horticulture, University of Puerto Rico - Mayaguez
Ph.D. in Plant Pathology, The Pennsylvania State University

Courses Taught:

BIOL 100 - General Biology and General Biology Lab
BIOL 363 - Medical Microbiology
BIOL 424 - Mycology
BIOL 461 - Microbiology
BIOL 471 - Topics in Biology: General Virology 
BIOL 472 - General Virology (Seminar)
BIOL 472 - Microbial Diseases (Seminar)

Areas of Specialization:

Molecular Bacteriology, Molecular Mycology, Bacterial Taxonomy, Environmental Microbiology, Microbe - Plant Interactions, and Bacteria - Fungal Interactions

Research Interest(s):

Bacterial Blotch Disease in Mushrooms - The student Stephanie Leedom oversees this project

Mushrooms are an ideal nutritional option for everyone; they are a good source of fiber, vitamins, and antioxidants. My current research interest is to study and stop Pseudomonas bacterium from causing bacterial blotch disease of mushrooms. The disease starts with brown spots around the mushroom cap and stalk, then the bacteria completely destroy the mushroom. It is believed that the Pseudomonas bacteria are always present inside the mushroom, waiting for the right temperature and humidity (environment factors) to attack. My approach to stop the bacteria is by studying the bacteria-fungi interactions and finding those crucial bacterial pathways that can be targeted (molecular biology). In order to accomplish our goal, we have decided to do RNA seq. This project is in collaboration with Dr. Jonathan Stoltzfus who will be helping with the RNA analysis. Since Pennsylvania is the main producer of mushrooms in the United States, this research is important because of the crop’s economic value. A better understanding of the disease process will lead to the development of reliable control methods.

Pineapple Crown Rot Disease - The student Emily Dinkel oversees this project

This is a project in collaboration with Dr. Lydia Rivera-Vargas at The University of Puerto Rico at Mayaguez. Pineapple is one of the four most economically important fruit crops in Puerto Rico’s agriculture. The crop was valued as $14.9 billion worldwide in 2016, and over the past nine years, the market has grown on an average of 3.3% per year. Puerto Rican growers encounter huge economic losses because of pineapple crown rot disease. We are trying to identify the bacteria that cause the disease and study their host-pathogen interactions. A better understanding of the disease process will lead to the development of reliable control methods.

Cannabis Soil Microbiome - The student Alan Snavely oversees this project

We are comparing the soil microbiome between hemp and other important crops in Pennsylvania like soybean and corn. We would like to study which beneficial and non-beneficial soil microbes are commonly found in each crop. Preferably, the beneficial microbes will be the same and the pathogenic microbes will be different. This knowledge is indispensable for crop rotation between the crops. This project is in collaboration with Dr. Alyssa Collins, Assistant Professor and Research Associate director of the Southeast Agricultural Research and Extension Center.

Selected Publication(s):

Accepted Laboratory Guide Manual

2017.  Laboratory Guide for Identification of Plant Pathogenic Bacteria. 4th Edition. Editors J. B. Jones, G. Sundin, and S. A. Miller.  Author of two chapters, the use of rep-PCR and MLSA for identification, classification, and nomenclature of bacteria.

Research Article in Preparation

*Samuel J. Martins, *Laura Ramos-Sepulveda, and Carolee T. Bull. Phylogenic analysis of pathogenic Pseudomonas spp. isolated from mushrooms with blotch disease in farms from Pennsylvania. *Both first authors

Published in Peer-Review Journals  

2019    Osdahi E., Martins S.J., Ramos-Sepulveda L., Rocha-Vieira F., Pecchia J.A., Beyer D.M.,  Bell T.H., Hockett K.L., and Bull B.T. 100 Years after Tolaas: Bacterial Blotch of Mushroom in the 21st Century. Plant Disease.

2018    Harmon C.L., Timilsina S., Bonkowski J., Jones D.D., Sun X., Vallad G.E., Ramos-Sepulveda L., Bull C.T., and Jones J.B. Bacterial gall of Loropetalum chinense caused by Pseudomonas amygdali pv. loropetali pv. nov. Plant Disease 102: 1-8. https://doi.org/10.1094/PDIS-04-17-0505-RE

2018    Rosenthal E.R., Ramos L., Koike S.T., and Bull C.T. First report of black rot caused by Xanthomonas campestris on arugula in California. Plant Disease https://doi.org/10.1094/PDIS-10-17-1538-PDN

2017    Koike S.T., Alger E.I., Ramos-Sepulveda L., and Bull C.T. First report of bacterial leaf spot caused by Pseudomonas syringae pv. tomato on kale in California. Plant Disease. 101(3):  504

2015    Ramos L.S., Sinn J.P., Lehman B.L., Peter K.A., and McNellis T.W. Mutation of the Erwinia amylovora pyrC gene causes pyrimidine auxotrophy and attenuated virulence in apple trees and immature apple and pear fruits. Letters in Applied Microbiology 60: 572-579.

2014    Ramos L.S., Lehman B.L., Peter K.A., and McNellis T.W. Mutation of the Erwinia amylovora argD gene causes arginine auxotrophy, non-pathogenicity in apples, and reduced virulence in pears. Applied and Environmental Microbiology 80(21): 6739-6749.

2013    Ramos L.S., Lehman B.L., Sinn J.P., Pfeufer E.E., Halbrendt N.O., and McNellis T.W. The fire blight pathogen Erwinia amylovora requires the rpoN gene for pathogenicity in apple. Molecular Plant Pathology 14(8): 838-843.