A CURE for <i>Salmonella</i>: A Laboratory Course in Pathogen Microbiology and Genomics

Rapid advances in genomics and bioinformatics, the vast amount of data generated by next-generation sequencing, and the penetration of the ‘-omics’ into many areas of biology have created a need for students with hands-on experience with computational and ‘big data’ methods. Additionally, laboratory experience in the isolation, identification, and characterization of unknown bacteria is a vital part of a microbiology student’s training. This lesson is a course-based undergraduate research experience (CURE) focusing on Salmonella enterica, a common and relatively low-virulence foodborne pathogen. In Module 1, students isolate and identify S. enterica strains from stream sediment, poultry litter, or other sources. They conduct phenotypic evaluation of antimicrobial resistance (AMR) and can search for plasmids. Isolates’ whole genomes may be sequenced by the United States FDA or public health laboratories, typically at no charge. In Module 2, students learn basic methods of genome assembly, analysis, annotation, and comparative genomics. They use easily accessible, primarily web-based tools to assemble their genomes and investigate areas of interest including serotype, AMR genes, and in silico evidence of mobile genetic elements. Either module can be used as a standalone learning experience. After course completion, students will be able to isolate and identify Salmonella from natural sources, and use computational analysis of microbial genomic data, particularly of the Enterobacteriaceae. This lesson offers undergraduate microbiologists a genuine research experience and a real-world microbiology application in genomic epidemiology, as well as a valuable mix of field, laboratory, and computational skills and experiences.

0 comments 3 reposts

Profile picture of Crystal Goldyn

Crystal Goldyn onto Dry Lab Activities-DNA Barcoding

Exploring the Complexities of Photosynthesis Through a Comic Strip

Photosynthesis is a conceptually challenging topic. The small scale at which photosynthesis takes place makes it difficult for students to visualize what is occurring, and students are often overwhelmed by all of the details of the process. This activity uses a freely-available comic to make learning photosynthesis more approachable and to help students identify their own misconceptions and questions about the process. This activity is appropriate for any college-level introductory biology course and although it was designed for an online class, it could be adapted for in-person learning. In this activity, students work through a four-part online module. Each part consists of readings and videos containing background information on the steps of photosynthesis followed by the corresponding portion of a comic on photosynthesis. Students then use the background information in the module and the comic to identify their own misconceptions and questions and post these in an online discussion forum. The online module is followed by a live session in which the instructor uses the student discussion posts to clarify any remaining questions. Learning about photosynthesis in the unique visual format of a comic allows students to more easily visualize a process that they cannot see with their own eyes. Students enjoyed this activity because it makes learning photosynthesis fun and less intimidating. This lesson is powerful because it allows the instructor to hear from all students in the course via the discussion forum and then tailor the live discussion session to cover student identified problem topics.

Primary Image: Overview of photosynthesis comic. This image comes from Jay Hosler’s comic Photosynthesis or “gimme some sugar” (© 2020 Jay Hosler, used with permission from the author).

0 comments 6 reposts

Profile picture of Crystal Goldyn

Crystal Goldyn onto Photosynthesis

A new approach to course-based research using a hermit crab-hydrozoan symbiosis

There are few feasible models for marine-focused inquiry laboratory activities, a notable shortcoming for instructors seeking to engage their students in meaningful, course-based research experiences (CUREs). We describe a multi-week CURE that investigates the symbiosis between hermit crabs and the hydrozoan Hydractinia spp. Although much is known about hermit crab biology, ecology, and behavior, little is known about Hydractinia, and less is known about the relationship between the two symbionts. Given their small size, low cost, and relative ease of maintenance, colonized hermit crabs may be useful subjects for student-driven research projects. We discuss our experiences with this system and offer adopters a suite of resources for in-lab implementation.

0 comments 1 reposts

Profile picture of Crystal Goldyn

Crystal Goldyn onto Ecology-symbiotic relationships

Integrating Community Ecology Into the Study of Parasites: Exploring the Effect of Host Behavior on Parasite Transmission Rates

Organismal life cycles are often presented as a set of facts to memorize in undergraduate biology courses. This approach is cognitively demanding for students and fails to convey how central life cycle diversity is in shaping ecological and evolutionary processes. Understanding the causes and consequences of life cycles is especially important when studying parasites with multiple life cycle stages for passing through diverse hosts. We designed a two-part lab activity to help our students gain a better understanding of the ecological interactions driven by parasite life cycles. Part I is a structured guide to reading a peer-reviewed journal article. Part II is a guided exercise in summarizing and interpreting mock experimental data involving a trematode parasite life cycle. These assignments helped students (1) understand how parasite life cycles shape ecological interactions with their hosts, (2) practice making predictions about species interactions using core ecological principles, and (3) practice quantitative reasoning and graph literacy skills by visualizing and interpreting data. We first used this activity as a self-guided lab exercise for an upper-division undergraduate parasitology class that switched from in-person to asynchronous-remote mid-semester. The stepwise structure of the activity allowed us to pinpoint the links in the chain of biological reasoning where students struggled most to guide target topic reviews in subsequent lectures. Here, we provide a summary of the activity, our experience with the activity, and suggestions for adapting the activity for a synchronous-remote or in-person class.

0 comments 2 reposts

Profile picture of Crystal Goldyn

Crystal Goldyn onto Science Literature

CURE-all: Large Scale Implementation of Authentic DNA Barcoding Research into First-Year Biology Curriculum

Growing calls in science education reform have emphasized wide-scale engagement of first-year undergraduate students in authentic research experiences; however, large course enrollments, inadequate student experience, limited resources and departmental inertia often create obstacles to reaching this goal. To help overcome these obstacles, the Department of Biology at James Madison University (JMU) has developed a cost-effective, scalable, and transferable semester-long (14-week) course-based undergraduate research experience (CURE) designed for large enrollment introductory biology labs. In this series of labs, first-year students use DNA barcoding to engage in authentic research practices drawn from the fields of ecology, molecular biology, and bioinformatics. These labs enable students to identify local species of plants, fungi, and invertebrates using student-generated DNA barcode sequences, which are then shared through a public database. Since their implementation at JMU in 2016, students in these labs have created and shared over 1,500 unique DNA barcode sequences and documented over 300 local species of plants, fungi, and invertebrates. These data are being used in an ongoing project comparing the biodiversity of forest edge versus forest interior habitats, but the labs are adaptable to almost any habitat or taxonomic group. In this article, we provide detailed descriptions of the content, logistics, and implementation of this 14-week series of labs. To our knowledge, this is among the largest-enrollment CUREs being offered to first-year undergraduates in the United States, and we hope that it can be useful to other institutions interested in documenting biodiversity and engaging introductory biology students in authentic research.

0 comments 10 reposts

Profile picture of Crystal Goldyn

Crystal Goldyn onto Dry Lab Activities-DNA Barcoding

Bioinformatics is a BLAST: Engaging First-Year Biology Students on Campus Biodiversity Using DNA Barcoding

In order to introduce students to the concept of molecular diversity, we developed a short, engaging online lesson using basic bioinformatics techniques. Students were introduced to basic bioinformatics while learning about local on-campus species diversity by 1) identifying species based on a given sequence (performing Basic Local Alignment Search Tool [BLAST] analysis) and 2) researching and documenting the natural history of each species identified in a concise write-up. To assess the student’s perception of this lesson, we surveyed students using a Likert scale and asking them to elaborate in written reflection on this activity. When combined, student responses indicated that 94% of students agreed this lesson helped them understand DNA barcoding and how it is used to identify species. The majority of students, 89.5%, reported they enjoyed the lesson and mainly provided positive feedback, including “It really opened my eyes to different species on campus by looking at DNA sequences”, “I loved searching information and discovering all this new information from a DNA sequence”, and finally, “the database was fun to navigate and identifying species felt like a cool puzzle.” Our results indicate this lesson both engaged and informed students on the use of DNA barcoding as a tool to identify local species biodiversity.

Primary Image: DNA Barcoded Specimens. Crane fly, dragonfly, ant, and spider identified using DNA barcoding.

0 comments 5 reposts

Profile picture of Crystal Goldyn

Crystal Goldyn onto Dry Lab Activities-DNA Barcoding

Three Research-Based Quantitative Reasoning Modules for Introductory Organismal Biology Laboratories

We have designed three laboratory modules for an introductory organismal biology course with an emphasis on quantitative reasoning and data analysis skills. Module 1 tests for dimorphism in crayfish chelae using a paired statistical design. Module 2 tests for allometric growth of tapeworm hook structures using a regression model. Module 3 tests for differences in stomatal densities between two groups of plants using a two-sample statistical approach. For all three modules, we emphasize the use of confidence intervals to draw statistical conclusions about hypotheses. Knowledge about the basic biology of animals and plants is required, including arthropods, platyhelminths, and vascular plants. Background reading on dimorphism, allometry, and transpiration provides the necessary foundation to develop questions and hypotheses. Some familiarity with R is necessary for both students and instructors, although the activities can be modified for analysis with Excel or another statistical package. These modules can be taught independently or together as a unit within a course. As stated in the AAAS document, Vision and Change: A Call to Action, the ability to use quantitative reasoning is a core competency that must be developed by all biology students. These modules address the call for instruction in quantitative reasoning and provide a hands-on active introduction to key tools that will be required to build students’ statistical repertoire in more advanced courses.

Primary Image: A highlight of the three modules used in our introductory organismal biology course, including the use of calipers to test for dimorphism in the size of crayfish chelae (upper right), a leaf impression (lower right) from a hydrangea plant (lower left) used to test hypotheses about stomata densities, and the image of an Echinococcus tapeworm (upper left) to test hypotheses about allometry.  

0 comments 2 reposts

Profile picture of Crystal Goldyn

Crystal Goldyn onto Labs-Quantitative Reasoning

Exploring Primary Scientific Literature through the Lens of the 5 Core Concepts of Biology

Biology students at the undergraduate level usually excel in knowing biological facts; however, they often struggle with connecting these facts to specific biological principles. In parallel, undergraduate students often struggle to read primary scientific literature (PSL), possibly for the same reason: they struggle to integrate the biological facts they know into the larger, and often complicated, biological principles presented in PSL. Our lesson bridges the gap between student understanding of content knowledge and their ability to connect this knowledge to larger biological principles through the integration of PSL and the 5 Core Concepts of Biology (5CCs) identified in the Vision and Change report. We begin by introducing students to PSL using a modified C.R.E.A.T.E. method and continue by walking students through Vision and Change as a way to introduce the 5CCs. Through the use of a matrix table detailing each one of the 5CCs and their related organizational levels, students learn how to integrate PSL and the 5CCs by connecting biological facts contained within PSL to a related biological core concept. Because students have to provide reasoning for why they connected a biological fact to a specific core concept, they begin to see biology as a larger entity, i.e., they begin to see the "big picture" of biology. Our lesson provides a novel strategy for introducing students to PSL.

0 comments 1 reposts

Profile picture of Crystal Goldyn

Crystal Goldyn onto Science Literature