Establishment and Validation of Pathogenic CS17 and CS19 Enterotoxigenic Escherichia coli Challenge Models in the New World Primate Aotus nancymaae.

Enterotoxigenic (ETEC) is a common cause of diarrheal illness in the military, travelers, and children living in low- to middle-income countries. Increased antibiotic resistance, the absence of a licensed vaccine, and the lack of broadly practical therapeutics perpetuate the significant health and financial burden resulting from ETEC infection. A critical step in the evaluation of vaccines and therapeutics is preclinical screening in a relevant animal disease model that closely replicates human disease. We previously developed a diarrheal model of class 5a colonization factor (CF) CFA/I-expressing ETEC in the New World owl monkey species using ETEC strain H10407. In order to broaden the use of the model, we report here on the development of models of ETEC expressing the class 5b CFs CS17 and CS19 with strains LSN03-016011/A and WS0115A, respectively. For both models, we observed diarrheal attack rates of ≥80% after oral inoculation with 5 × 10 CFU of bacteria. These models will aid in assessing the efficacy of future ETEC vaccine candidates and therapeutics.