Journal List > Korean J Clin Microbiol > v.13(3) > 1038192

Korean J Clin Microbiol. 2010 Sep;13(3):128-131. Korean.
Published online September 30, 2010.  https://doi.org/10.5145/KJCM.2010.13.3.128
Copyright © 2010 The Korean Society of Clinical Microbiology
Aberrant Forms of Escherichia coli in Urine Culture
Youngeun Ma, Jang Ho Lee, Seung-Tae Lee, Chang-Seok Ki and Nam Yong Lee
Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.

Correspondence: Nam Yong Lee, Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul 135-710, Korea. (Tel) 82-2-3410-2706, (Fax) 82-2-3410-2719, Email: micro.lee@samsung.com
Received February 07, 2010; Revised July 13, 2010; Accepted August 20, 2010.

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.

Keywords: Atypical bacterial forms; Escherichia coli; Urine

Figures


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).
Click for larger image


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).
Click for larger image


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

References
1. Gardner AD. Morphological effects of penicillin on bacteria. Nature 1940;146:837–838.
2. Louria DB, Kaminski T, Grieco M, Singer J. Aberrant forms of bacteria and fungi found in blood or cerebrospinal fluid. Arch Intern Med 1969;124:39–48.
3. Middleton J, Chmel H. Aberrant form of Pseudomonas aeruginosa in sputum and cerebrospinal fluid causing infection in a compromised patient. J Clin Pathol 1978;31:351–354.
4. Magnussen CR, Hruska JF. Aberrant forms of Escherichia coli in blood cultures: in vitro reproduction of an in vivo observation. J Clin Microbiol 1980;12:690–694.
5. Lorian V, Waluschka A, Kim Y. Abnormal morphology of bacteria in the sputa of patients treated with antibiotics. J Clin Microbiol 1982;16:382–386.
6. Lorian V, Atkinson B. Abnormal forms of bacteria produced by antibiotics. Am J Clin Pathol 1975;64:678–688.
7. Lorian V, Atkinson B. Effect of serum on gram-positive cocci grown in the presence of penicillin. J Infect Dis 1978;138:865–871.
8. Kim AS, Kang JC, Lee SH. Unusual morphology of aberrant forms of bacteria in urine: presented with grotesque-giant form with central emptiness and fusiform ends. Korean J Clin Pathol 1998;18:403–406.
9. Kwon HJ, Seo EJ, Shim SI. Aberrant forms of bacteria in urine: report of three cases. Korean J Clin Pathol 1993;13:479–481.
10. Yoon KH, Kim CJ, Cho JH, Moon YH. Abnormal forms of bacteria produced by antimicrobial agents in vitro. Korean J Clin Pathol 1995;15:264–272.
11. Yamamoto S, Harayama S. PCR amplification and direct sequencing of gyrB genes with universal primers and their application to the detection and taxonomic analysis of pseudomonas putida strains. Appl Environ Microbiol 1995;61:3768.
12. Sung H, Kim MN. Reliability of sequence-based identification of microorganism. Infect Chemother 2008;40:355–356.