Staphylococcus lugdunensis is a coagulase-negative member of the genus Staphylococcus

Staphylococcus

Staphylococcus is a genus of Gram-positive bacteria. Under the microscope they appear round , and form in grape-like clusters....

, consisting of Gram-positive

Gram-positive

Gram-positive bacteria are those that are stained dark blue or violet by Gram staining. This is in contrast to Gram-negative bacteria, which cannot retain the crystal violet stain, instead taking up the counterstain and appearing red or pink...

 bacteria with spherical cells that appear in clusters.

History

It was first described in 1988 after being differentiated through DNA analysis. Its name comes from Lugdunum, the latin name for Lyon

Lyon

Lyon , is a city in east-central France in the Rhône-Alpes region, situated between Paris and Marseille. Lyon is located at from Paris, from Marseille, from Geneva, from Turin, and from Barcelona. The residents of the city are called Lyonnais....

, France, where the organism was first isolated.

Description

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

Hay

Hay is grass, legumes or other herbaceous plants that have been cut, dried, and stored for use as animal fodder, particularly for grazing livestock such as cattle, horses, goats, and sheep. Hay is also fed to pets such as rabbits and guinea pigs...

-like odor.

S. lugdunensis may produce a bound coagulase

Coagulase

Coagulase is a protein produced by several microorganisms that enables the conversion of fibrinogen to fibrin. In the laboratory, it is used to distinguish between different types of Staphylococcus isolates. Coagulase negativity excludes S. aureus. That is to say, S...

 (that is, the enzyme

Enzyme

Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...

 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

Ornithine

Ornithine is an amino acid that plays a role in the urea cycle.-Role in urea cycle:L-Ornithine is one of the products of the action of the enzyme arginase on L-arginine, creating urea. Therefore, ornithine is a central part of the urea cycle, which allows for the disposal of excess nitrogen....

 and it is positive for pyrrolidonyl arylamidase (PYR).

Note

In the past it was frequently misidentified as S. hominis

Staphylococcus hominis

Staphylococcus hominis is a coagulase-negative member of the bacterial genus Staphylococcus, consisting of Gram positive, spherical cells in clusters. It occurs very commonly as a harmless commensal on human and animal skin. However, like many other coagulase-negative staphylococci, S...

, S. aureus

Staphylococcus aureus

Staphylococcus aureus is a facultative anaerobic Gram-positive coccal bacterium. It is frequently found as part of the normal skin flora on the skin and nasal passages. It is estimated that 20% of the human population are long-term carriers of S. aureus. S. aureus is the most common species of...

or other species.

Clinical

It has been recorded as a cause of serious human infections such as osteomyelitis

Osteomyelitis

Osteomyelitis simply means an infection of the bone or bone marrow...

, septicaemia, and aggressive endocarditis

Endocarditis

Endocarditis is an inflammation of the inner layer of the heart, the endocardium. It usually involves the heart valves . Other structures that may be involved include the interventricular septum, the chordae tendineae, the mural endocardium, or even on intracardiac devices...

.

It is generally susceptible to anti-staphylococcal antibiotics but increasing penicillin resistance has been reported.