Morphological variability of Escherichia coli colonizing human wounds: a case report.

Abstract

Background: Escherichia coli, known for its adaptability, can cause diverse infections. Morphological variants, such as smooth and mucoid forms, correspond to different infection capabilities and antibiotic resistance profiles. This report presents the isolation of two distinct E. coli strains, a smooth strain and a mucoid strain, from a single patient.

Case presentation: A 70-year-old woman with a leg wound and lung infection was found to have two E. coli strains: a mucoid strain from her wound and sputum and a smooth strain from her rectal swab. Whole-genome sequencing confirmed genetic similarity between the strains with minor SNPs linked to their morphological differences. Both strains were resistant to β-lactam and quinolone antibiotics, complicating treatment. The patient recovered following treatment with Piperacillin/Tazobactam and regular wound care.

Conclusion: This case highlights E. coli's phenotypic plasticity within a single host, impacting infection management and antibiotic response. Understanding the genetic basis of such morphological changes could inform more effective treatment strategies.