What does Gram-positive cocci refer to?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: April 3, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

Gram positive cocci are spherical bacteria that retain a purple color after undergoing Gram staining, indicating they have a thick peptidoglycan cell wall, and include important pathogens such as Staphylococcus, Streptococcus, and Enterococcus species. These bacteria are distinguished from Gram negative bacteria by the thick peptidoglycan layer in their cell walls, which contains teichoic acids and lacks an outer membrane. This structural difference affects their susceptibility to antibiotics, with Gram positive cocci generally being more susceptible to penicillins, cephalosporins, and vancomycin 1. Common infections caused by these organisms include skin infections, pneumonia, endocarditis, and sepsis. Proper identification of Gram positive cocci through microscopy and culture is essential for guiding appropriate antibiotic therapy, as different species have varying antibiotic resistance patterns and virulence factors.

  • Key characteristics of Gram positive cocci include:
    • Thick peptidoglycan cell wall
    • Presence of teichoic acids
    • Lack of outer membrane
    • Susceptibility to penicillins, cephalosporins, and vancomycin
  • Important pathogens among Gram positive cocci include:
    • Staphylococcus (typically appear in clusters)
    • Streptococcus (form chains)
    • Enterococcus species
  • Common infections caused by Gram positive cocci include:
    • Skin infections
    • Pneumonia
    • Endocarditis
    • Sepsis According to the most recent and highest quality study, the diagnosis and management of infections caused by Gram positive cocci should prioritize proper identification of the causative organism and selection of appropriate antibiotic therapy 1.

From the FDA Drug Label

Daptomycin has clinical utility in the treatment of infections caused by aerobic, Gram-positive bacteria. The in vitro spectrum of activity of daptomycin encompasses most clinically relevant Gram-positive pathogenic bacteria Daptomycin exhibits rapid, concentration-dependent bactericidal activity against Gram-positive bacteria in vitro. Antimicrobial Activity Daptomycin has been shown to be active against most isolates of the following microorganisms both in vitro and in clinical infections Gram-Positive Bacteria Enterococcus faecalis (vancomycin-susceptible isolates only) Staphylococcus aureus (including methicillin-resistant isolates) Streptococcus agalactiae Streptococcus dysgalactiae subsp. equisimilis Streptococcus pyogenes

Gram positive cocci means bacteria that have a gram positive cell wall and are shaped like cocci (spherical). Examples include:

  • Staphylococcus aureus
  • Streptococcus agalactiae
  • Streptococcus dysgalactiae subsp. equisimilis
  • Streptococcus pyogenes
  • Enterococcus faecalis 2

From the Research

Definition of Gram Positive Cocci

  • Gram positive cocci refer to a type of bacteria that has a gram-positive cell wall and a cocci (spherical) shape.
  • Examples of gram positive cocci include Staphylococcus aureus 3, 4, 5, 6 and Streptococcus species 7.

Characteristics of Gram Positive Cocci

  • Gram positive cocci are typically spherical in shape and can be found singly, in pairs, or in clusters.
  • They have a thick peptidoglycan cell wall that retains the crystal violet stain used in the Gram staining procedure, giving them a purple appearance under a microscope.
  • Gram positive cocci can cause a range of infections, including skin infections, respiratory infections, and endocarditis 3, 4, 5, 7, 6.

Examples of Gram Positive Cocci

  • Staphylococcus aureus is a type of gram positive coccus that is commonly found on the skin and in the nose, but can cause serious infections if it enters the bloodstream or other parts of the body 3, 4, 5, 6.
  • Streptococcus species are another type of gram positive coccus that can cause infections such as strep throat and endocarditis 7.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.