Staphylococcus lugdunensis

Staphylococcus lugdunensis
Scientific classification
Kingdom: Bacteria Phylum: Firmicutes Class: Cocci Order: Bacillales Family: Staphylococcaceae Genus: Staphylococcus Species: S. lugdunensis
Binomial name
Staphylococcus lugdunensis Freney et al. 1988

Staphylococcus lugdunensis is a member of the genus Staphylococcus, consisting of Gram-positive bacteria with spherical cells that appear in clusters. It was first described in 1988 and was recorded as a cause of serious human infections such as endocarditis, osteomyelitis, and septicaemia. It occurs as a commensal on human skin. In the past it was frequently misidentified as S. hominis, S. aureus, or other species.

S. lugdunensis may produce a bound coagulase (that is, the enzyme is bound to the cells), a property which it shares with S. aureus, but unlike S. aureus it does not produce a free coagulase. In the laboratory it can give a positive slide-coagulase test but a negative tube-coagulase test.

S. lugdunensis is fairly easy to identify because unlike the great majority of staphylococci it decarboxylates ornithine. (Very occasional strains of other species may do the same.)

Colonies of S. lugdunensis are usually hemolytic, sticky, yellow or tan and about 2-4 mm in diameter after a 48-hour incubation. They usually have a characteristic odour.

Antimicrobial therapy

• Postpartum mastitis with or without abscess

• Preferred regimen: In outpatient is Dicloxacillin 500 mg po qid OR Cephalexin 500 mg po qid and in inpatient is Oxacillin OR Nafcillin 2 gm IV q4h
• Alternative regimen: In outpatient is Trimethoprim-Sulfamethoxazole-DS tabs 1-2 po bid or, if susceptible, Clindamycin 300 mg po qid and in inpatient is Vancomycin 1 gm IV q12h; if over 100 kg, 1.5 gm IV q12h.

Note (1): Mastitis with no abscess- increase frequency of nursing may hasten response.

Note (2): Mastitis with abscess- needle aspiration reported successful. Resume breast feeding from affected breast as soon as pain allows.

• Non-puerperal mastitis with abscess

• Preferred regimen: In outpatient is Dicloxacillin 500 mg po qid OR Cephalexin 500 mg po qid and in inpatient is Oxacillin OR Nafcillin 2 gm IV q4h
• Alternative regimen: In outpatient is Trimethoprim-Sulfamethoxazole-DS tabs 1-2 po bid or, if susceptible, Clindamycin 300 mg po qid and in inpatient is Vancomycin 1 gm IV q12h; if over 100 kg, 1.5 gm IV q12h.

Note (1): If subareolar & odoriferous, most likely anaerobes; need to add Metronidazole 500 mg IV/po tid.

Note (2): If not subareolar, staph. Need pretreatment aerobic/anaerobic cultures. Surgical drainage for abscess.

Note (3):Staphylococcus lugdunensis usually susceptible to gentamicin. 75% are penicillin-susceptible.

Template:Bacteria-stub