Staphylococcus hominis- An Overview


Staphylococcus hominis is a member of the bacterial genus Staphylococcus, which consists of Gram-positive, spherical cells that form clusters. The genus Staphylococcus is classified into different species based on various characteristics, such as DNA-DNA hybridization, fatty acid composition, G+C content, and biochemical reactions .

Staphylococcus hominis is further divided into two subspecies: S. hominis subsp. hominis and S. hominis subsp. novobiosepticus. These subspecies are distinguished by their susceptibility to novobiocin, an antibiotic that inhibits DNA gyrase, and their habitat .

S. hominis subsp. hominis consists of strains that are susceptible to novobiocin and are primarily found on the human skin surface, especially in areas with apocrine glands, such as the axillae and the pubic region . These strains are part of the normal skin flora and usually do not cause infections unless the host is immunocompromised or has a medical device implant.

S. hominis subsp. novobiosepticus consists of strains that are resistant to novobiocin and can be isolated from blood cultures of patients with sepsis or endocarditis . These strains are more virulent and more resistant to other antibiotics than S. hominis subsp. hominis. They can cause serious infections in neonates, cancer patients, and patients with artificial valves.

The following table summarizes the main differences between the two subspecies of S. hominis:

Characteristic S. hominis subsp. hominis S. hominis subsp. novobiosepticus
Novobiocin susceptibility Susceptible Resistant
Habitat Skin surface Blood
Acid production from D-trehalose and N-acetylglucosamine (aerobically) Positive Negative
Arginine utilization Positive Negative