Korean J Clin Microbiol.  2010 Sep;13(3):128-131. 10.5145/KJCM.2010.13.3.128.

Aberrant Forms of Escherichia coli in Urine Culture

• Ma Y
• Lee JH
• Lee ST
• Ki CS
• Lee NY

• KMID: 1461627
• DOI: http://doi.org/10.5145/KJCM.2010.13.3.128

Abstract

Bacterial morphology can be altered by various factors, including antibiotics. Unusually shaped, large, swollen organisms were observed in a urine culture obtained from a patient who had no history of antibiotic therapy. The organism was identified as Escherichia coli by the Vitek 2 system and by DNA sequencing of 16S rRNA and gyrB. The patient had no symptoms except fever, which subsided without medication. Microbiology laboratories should be aware of the potential appearance of such bacilli to avoid confusion with fungi and other naturally occurring filamentous organisms.

Keyword

Atypical bacterial forms; Escherichia coli; Urine

MeSH Terms

Anti-Bacterial Agents
Atypical Bacterial Forms
Escherichia
Escherichia coli
Fever
Fungi
Humans
Sequence Analysis, DNA
Anti-Bacterial Agents

Figure

• 

  Fig. 1. (A) Small, dry and purple colonies in MacConkey agar plate, 2 days, (B) Comparison with E. coli ATCC 25922, in MacConkey agar plate, 2 days (left: E. coli ATCC 25922).

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  Fig. 2. Unusual shaped large, swollen organisms resembling fungus spore were mixed with a few normal sized bacilli. Long bacilli, filamentous form and elongated bacilli with bulge were also seen (Gram stain, ×1,000).

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  Fig. 3. The organism reverted to normal Gram-negative bacilli. But, some are still larger than normal E. coli (Gram stain, ×1,000).

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