Journal List > Korean J Clin Microbiol > v.13(4) > 1038204

Korean J Clin Microbiol. 2010 Dec;13(4):178-181. Korean.
Published online December 27, 2010.
Copyright © 2010 The Korean Society of Clinical Microbiology
A Case of Pneumonia Caused by Balantidium coli in an Immunocompetent Patient
Koung-Sun Lee,1 Do-Sim Park,1,3 Ji-Hyun Cho,1,3 Hak-Yeol Kim,2,3 and Young-Jin Lee1,3
1Department of Labroatory Medicine, School of Medicine, Wonkwang University, Iksan, Korea.
2Department of Internal Medicine, School of Medicine, Wonkwang University, Iksan, Korea.
3Institute of Wonkwang Medical Science, School of Medicine, Wonkwang University, Iksan, Korea.

Correspondence: Young-Jin Lee, Department of Laboratory Medicine, School of Medicine, Wonkwang University, 344-2 Sinyong-dong, Iksan 570-711, Korea. (Tel) 82-63-859-1862, (Fax) 82-63-842-3786, Email:
Received May 24, 2010; Revised July 28, 2010; Accepted August 20, 2010.


Balantidium coli is the only largest ciliated protozoon known to infect human and nonhuman primates. Balantidiasis is a zoonotic disease and is acquired by humans via fecal-oral contact between pigs and humans. The clinical manifestation includes mainly gastrointestinal symptoms; diarrhea and abdominal pain, but in rare cases extraintestinal spread to lungs has been reported. A few reports of B. coli were found in vaginal secretion, skin, gastric juice, and omentum, but there have been no previous isolated cases in the respiratory tract in Korea. We reported that the first case of pneumonia caused by B. coli in Korea in an immunocompetent 40-year-old woman who displayed symptoms of chest discomfort and cough, and was cured with metronidazole.

Keywords: Balantidium coli; Pneumonia; Metronidazole


Fig. 1
Radiologic finding of organizing pneumonia at left upper lung field. (A) Chest PA showed segmental distribution of air space consolidation at the left upper lung field. (B) Chest CT showed air space consolidation and atelectasis at lingular division of left upper lung.
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Fig. 2
Microscopic finding of Balantidium coli. (A) Oval shaped trophozoites has covered whole body with short cilia (arrow) in bronchial brush (×400, wet smear). (B) The trophozoite showed macronucleus and indistinct cilia (×400, PAP stain).
Click for larger image

Fig. 3
Flexible bronchoscopy showed severe mucosal inflammation with purulent secretion in the lingular segment of left upper lobe bronchus.
Click for larger image

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