Amanda Ojeda wins the trainee research poster competition

Headshot of Amanda Ojeda

College of Agriculture and Life Sciences graduate student Amanda Ojeda won best research poster in the EPI Research Day 2023 trainee research poster competition. Her research focused on identifying the prevalence and the composition of Campylobacter species in infants in a rural area of eastern Ethiopia during their first year of life and potential reservoirs. The project was a team collaboration between Ojeda and collaborators at the University of Florida, Haramaya University, Ohio State University, Washington University in St. Louis and Massey University in New Zealand. 

“This was not a win for myself,” Ojeda said. “This was a win for the team because we consider ourselves family. We’ve all put in a lot of effort and overcome many barriers working throughout the pandemic and civil unrest.” 

A longitudinal study was conducted from December 2020- June 2022. During this, 106 households from 10 different kebeles (administrative units) were followed. Monthly infant stool and surveys were collected, followed by biannual mother, sibling, livestock, and environmental samples to assess the prevalence of CampylobacterCampylobacter is the leading cause of diarrheal disease worldwide but also leads to chronic inflammation and increased intestinal permeability, commonly known as “leaky gut,” which can lead to poor absorption of nutrients, increasing the risk of stunting and malnutrition. 

The team found a high prevalence of Campylobacter across all samples and a high predominance of poorly studied non-thermophilic species in infants. Approximately 3,000 samples were collected. Ojeda aims to finish testing the remaining half by the end of March. 

Ojeda earned her Bachelor of Science in Microbiology and Cell Science and her Master of Public Health and Master of Medical Microbiology & Biochemistry at the University of Florida. She plans to graduate with a Ph.D. in Microbiology and Cell Science. She hopes to attend the American Society of Microbiology national conference, which the award will help fund. After she earns her degree, she sees a future in teaching and engaging in international collaborations to improve maternal and child health through microbiome research.

Discovering the Microbial Landscape: an investigation of Campylobacter in infants and household environments in rural Eastern Ethiopia


  • Amanda Ojeda – Department of Microbiology and Cell Science, University of Florida
  • Loic Deblais – Ohio State University
  • Bahar Mummed Hassen – Haramaya University
  • Mussie Brhane – Haramaya University
  • Kedir Hassen – Haramaya University
  • Belisa Usmael- Haramaya University
  • Yenenesh Demisie – Haramaya University
  • Arie H. Havelaar – Institute of Food and Agricultural Sciences, University of Florida
  • Luiz Roesch – Department of Microbiology and Cell Science, University of Florida
  • Gireesh Rajashekara – Ohio State University


High prevalence of Campylobacter infections in low-resource settings is a major contributor to environmental enteric dysfunction (EED) and stunting in children. In 2018, our cross-sectional study detected Campylobacter in 88% of child stools (8-367 days of age) collected in rural eastern Ethiopia using Meta-total RNA sequencing. An average of 11 Campylobacter species (thermophilic and non-thermophilic) were detected per positive stools. Therefore, a longitudinal study of the Campylobacter Genomics and  EED  (CAGED) project was conducted to identify Campylobacter species associated with EED/stunting and to define reservoirs associated with early infections of Campylobacter spp. in infants.


Infant stool samples (n=1,073) were collected monthly from birth to 12 months. Environmental samples (soil and water), livestock feces (cattle, chicken, goat, and sheep), and human stools (mother and sibling) were collected biannually (n=1,744). Campylobacter genus detection was done using TaqMan real-time PCR targeting 16SRNA in field samples. Species-specific quantitative PCR (cpn60 and hipO) was done on one thermophilic and three non-thermophilic Campylobacter species to assess prevalence and diversity. In-house validation of primer specificity and sensitivity was done.


Campylobacter was detected in all households selected in this study (n=106), with 71% of field samples being positive for Campylobacter at the genus level. To date, (1,439/2,817) have been tested using species-specific qPCR. Non-thermophilic Candidatus C. infans and thermophilic C. jejuni were predominant in human samples (23-44%), followed by C.upsaliensis (11%). Of these, C. infans was prevalent in 42% of infant stools and in 51.7% of mother/sibling stools. C. jejuni was common in environmental samples (24%). Other Campylobacter species were rarely detected (<2%). Detection of C. infans increased as the child aged, with 20% positivity (51/251) at <6 months of age which surged to 58% (219/380) at >6 months of age. Similarly, C. jejuni prevalence increased as the child aged, with 6% positivity (16/251) in infants <6 months of age and 38% (148/389) at >6 months of age.


Our study found a high prevalence of Campylobacter in infants in Eastern Ethiopia, with non-thermophilic species being the most predominant. Further testing is underway to determine the prevalence, distribution, and sources of infection and assess dietary and WASH risk factors. Our findings provide new insight into the relationship between Campylobacter and infants in Eastern Ethiopian households and hold the potential to inform interventions that reduce the transmission of Campylobacter to infants, thereby improving their health by mitigating the risks of EED and stunting.