First report of Escherichia albertii in Iran: a case study highlighting diagnostic challenges in pediatric gastroenteritis.

Background: Escherichia albertii is a gram-negative, facultative anaerobic bacillus in the order Enterobacterales, family Enterobacteriaceae, increasingly recognized as an emerging enteropathogen. Initially isolated in 1991 from a child with diarrhea in Bangladesh and misclassified as Hafnia alvei, it was reclassified in 2003 and is now acknowledged as the second pathogenic species of the Escherichia genus, following Escherichia coli. Case Summary: This article reports the first documented case of E. albertii in Iran, infecting a 5-year-old girl who presented with profuse watery diarrhea. During a 7-month surveillance study at Akbar Children's Hospital in Mashhad, stool samples from 231 children with diarrhea were analyzed, with this single case demonstrating infection by E. albertii. The strain was identified through pentaplex PCR but exhibited phenotypic traits highly similar to other enteropathogens and showed resistance to antibiotics, such as ampicillin and amoxicillin-clavulanate. Conclusion: The study highlights the diagnostic challenges associated with the discrimination between E. coli and E. albertii, which is often misidentified when solely biochemical tests are used. Our findings and literature data suggest that E. albertii should be considered a significant cause of pediatric gastroenteritis, akin to Shigella and enteroinvasive E. coli. These observations emphasize the need for adequate diagnostic protocols, including PCR testing, to accurately identify E. albertii and inform appropriate clinical management strategies. Further research is necessary to deepen our understanding of this emerging pathogen and its implications for human health.