|Cardiobacterium hominis on blood agar plate|
Cardiobacterium hominis is a Gram-negative rod commonly grouped with other bacteria into the HACEK group. It is one of several bacteria normally present in the respiratory tract. However, it may also rarely cause endocarditis, an infection of the heart valves.
C. hominis is a catalase-negative, oxidase-positive, indole-producing Gram-negative rod. Its morphology has classically been described as highly pleomorphic and irregularly staining, although homogeneous bacilli with uniform shapes may be seen with the addition of yeast extract.
Historically C. hominis has been sensitive to penicillin and penicillin derivatives such as ampicillin. However, penicillin-resistant strains, including those that produce beta-lactamases, have been described with increasing frequency. Clinical guidelines thus recommend that C. hominis and other HACEK organisms be presumed to harbor ampicillin resistance and therefore be treated with a third-generation cephalosporin. C. hominis and other HACEK organisms also exhibit in vitro susceptibility to trimethoprim-sulfamethoxazole, fluoroquinolones, and aztreonam. C. hominis is often resistant to erythromycin.
- Malani AN, Aronoff DM, Bradley SF, Kauffman CA (September 2006). "Cardiobacterium hominis endocarditis: Two cases and a review of the literature". European Journal of Clinical Microbiology & Infectious Diseases 25 (9): 587–95. doi:10.1007/s10096-006-0189-9. PMC 2276845. PMID 16955250.
- Savage DD, Kagan RL, Young NA, Horvath AE (January 1977). "Cardiobacterium hominis endocarditis: description of two patients and characterization of the organism". Journal of Clinical Microbiology 5 (1): 75–80. PMC 274535. PMID 833269. Retrieved 2010-03-15.
- Wilson WR, Karchmer AW, Dajani AS, et al. (December 1995). "Antibiotic treatment of adults with infective endocarditis due to streptococci, enterococci, staphylococci, and HACEK microorganisms. American Heart Association". JAMA 274 (21): 1706–13. doi:10.1001/jama.274.21.1706. PMID 7474277.
- Lu PL, Hsueh PR, Hung CC, Teng LJ, Jang TN, Luh KT (May 2000). "Infective endocarditis complicated with progressive heart failure due to beta-lactamase-producing Cardiobacterium hominis". Journal of Clinical Microbiology 38 (5): 2015–7. PMC 86656. PMID 10790145. Retrieved 2010-03-15.
- Michael A. Pfaller; Murray, Patrick R.; Rosenthal, Ken S. (2009). Medical microbiology. Philadelphia: Mosby / Elsevier. p. 374. ISBN 0-323-05470-6.