2010 Volume 25 Issue 3 Pages 135-144
Klebsiella pneumoniae and Klebsiella oxytoca are commonly isolated from hospital patients and the isolation ratio of these bacteria is 4 : 1 in Japan according to the JANIS surveillance. We observed similar isolation frequencies of these bacteria in three general hospitals from August 2008 to July 2009, and found that the isolation rate of K. oxytoca was especially high in the bile of patients as compared with that of K. pneumoniae in a general hospital. Epidemiological study based on biological characters and antibiograms revealed at least 2 small outbreaks in the bile isolates of K. pneumoniae and 4 small outbreaks in K. oxytoca during the observed year. Measurement of the bile resistance of representative isolates (12 of K. pneumoniae and 12 of K. oxytoca) from various specimens found that 108 of K. pneumoniae and K. oxytoca were eliminated to 105-102 after 2 hours incubation in the bile, indicating that both bacteria were similarly sensitive to human bile, except one K. pneumoniae strain isolated from the urine of a patient. The high isolation rate of K. oxytoca from bile in our general hospital was not due to bile resistance, but was related to small outbreaks among patients in this hospital.
