A clinicаl micrоbiоlоgist is studying а suspected E. coli UTI in а patient. After obtaining a sample from the patient and immediately performing a Gram stain, the bacterial cells were determined to be Gram-negative with a filamentous shape. However, after culturing the sample for 24 hours, the cells were observed to be Gram-negative bacillus-shaped cells. What is the most likely explanation for these results?