Leuconostoc spp

Gram Stain

• Gram positive cocci in pairs and chains (aerobic)

Clinical Significance

These organisms are found in dairy products, various foods/vegetation and may be found in the gastrointestinal and female genital tracts.

They have been associated with bacteremia (including in neonates), meningitis, peritonitis, wound, urinary and medical device related infections, typically in immunocompromised patients.

Infections are often polymicrobial in patients who have received previous broad spectrum antibiotic therapy. Immunosuppression, prematurity, indwelling medical devices, total parenteral nutrition, underlying gastrointestinal abnormalities, and previous antibiotic therapy are all risk factors.

Usual Susceptibility Pattern

These organisms are resistant to vancomycin and TMP/SMX and exhibit decreased susceptibility to cephalosporins (especially 3rd generation). 

Carbapenem resistance has also been described.

Susceptibility to clindamycin, macrolides, quinolones, and aminoglycosides is variable.

Tolerance to penicillin/ampicillin has also been described.