Johns Hopkins Guides provide diagnosis, management, and treatment guidance for infectious diseases, diabetes, and psychiatric conditions. Explore these free sample topics:
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- As a term, coryneform ("club-shaped") bacteria is sometimes used to denote a wide range of Gram-positive rods based on staining characteristics and DNA content (specific G/C ratios).
- Corynebacterium spp. included, but also others (Arcanobacterium, Rothia mucilaginosa).
- Genus with two major human species:
- Corynebacterium diphtheriae (see separate module)
- Non-diphtherial species, also referred to as "diphtheroids." Classification of this group now based on RNA homology rather than within previous cornyeform group. Many part of normal human skin flora. Partial listing of most commonly encountered pathogens below, more complete listing (53 pathogens) in Bernard . Organisms remain rare causes of human infection.
- C. pseudotuberculosis: cause of caseous lymphadenitis in goats and sheep; human infection typically derived from contact with infected animals. Occasional agent of human lymphadenitis or respiratory diphtheria.
- C. ulcerans: infection from handling infected animals or contact with contaminated milk. Occasional cause of human respiratory diphtherial infection. See diphtheria module for public health and treatment recommendations.
- Other occasional human pathogens: often afflicting hospitalized/immunocompromised patients; organisms typically with significant antibiotic-resistance profiles.
- C. amycolatum: may be under-recognized as frequently misidentified as C. jeikeium or C. urealyticum.
- C. bovis: bacteremia (rare)
- C. hemolyticum: now Arcanobacterium hemolyticum.
- C. jeikeium: originally termed group JK. May cause bacteremia, endocarditis, device/prosthesis infections, wound infections--especially in immunocompromised patients with hematological disorders or vascular catheters.
- C. striatum: described as an emerging nosocomial pathogen; endocarditis, lung or bone infections, device infections, septic arthritis
- C.tuberculostearicum:may be misidentified by lab, often multidrug resistant.
- C. urealyticum: capable of hydrolyzing urea. Genitourinary infections (encrusted cystitis) >> bacteremia, endocarditis, wound infections.
- C. xerosis: rare and usually afflicting immunocompromised or cardiac valve patients.
- Species identification recommended for any isolate thought to be causing human infection.
- Gram positive rods, catalase positive and non-motile.
- May be aerobic or facultatively anaerobic.
- Not acid fast.
- Most grow on conventional media, though some require addition of lipids for growth.