Gemella spp

• G. bergeri
• G. haemolysans
• G. morbillorum
• G. parahaemolysans
• G. sanguinis
• G. taiwanensis

Gram Stain

• Gram positive cocci in pairs, tetrads and clusters (aerobic)

Clinical Significance

These organisms are part of the commensal flora of the respiratory and gastrointestinal tracts.

They have been associated with bacteremia, endocarditis, meningitis, brain abscesses, peritonitis, sinusitis, as well as bone and joint, pleuropulmonary, prosthetic device related, wound and genitourinary infections, typically in immunocompromised patients. There is a possible link between G. morbillorum bacteremia and colorectal cancer.

Usual Susceptibility Pattern

Some strains exhibit penicillin tolerance.

Resistance to ceftriaxone has been rarely described.

They are usually resistant to TMP/SMX and exhibit variable susceptibility to tetracyclines and macrolides.

Although typically susceptible to vancomycin, resistance has been reported in G. haemolysans.