Introduction:

Kluyvera ascorbata is a gram-negative, catalase-positive, oxidase-negative, aerobic fermentative bacterium with flagella. This organism colonizes in the human body and its pathogenicity is extremely low; few clinical cases of K. ascorbata infection have been reported.
Presentation of case:
We report on a patient who experienced severe sepsis and acute cholangitis due to K. ascorbata bacteremia and was treated with levofloxacin following antibiotic susceptibility testing. To our knowledge, this is the first case report of third-generation cephalosporins resistant K. ascorbata infection in Japan.
Discussion:
Although this pathogen produces innate CTX-M type β-lactamases and is generally resistant to first- and second-generation penicillins and cephalosporins, multi-drug resistant K. ascorbata infection, including ceftriaxone resistant infection has seldom been reported.
Conclusion:
The increase of drug-resistant pathogens is of concern; in such cases, rapid microbial identification and appropriate antibiotic selection are crucial for successful treatment.