Early childhood preservice teachers' understanding of the infection model and its application in diaper changing

This study explores the understanding and application of the infection model, specifically focusing on cystitis caused by Escherichia coli (E. coli) in a diaper-changing context, among preservice teachers (PSTs). Fifty-four PSTs participated in a modeling sequence including experimentation. The PSTs' comprehension of infection mechanisms and the human body's response to bacterial infections were analyzed using a framework that addressed components, mechanisms, and phenomena related to the infection model. Data consisted of six tasks (two initial, two intermediate, two final). Findings show that PSTs improved the understanding of the infection model, especially in the components and mechanisms dimension. The experimentation mainly facilitated a deeper knowledge about E. coli. Nevertheless, although the PSTs learned the proper diaper-changing techniques to prevent infections, in some cases they failed to justify their actions using the infection model.