Gram positive
Clusters arrangement
Catalase positive
Coccus shaped
Catalase negative
Gram positive
Coccus shaped
Chains arrangement
Gram negative
Coccus shaped
Perform a coagulase test
Staphylococcus aureus is positive .... Staphylococcus epidermidis and Staphylococcus saprophyticus are negative
Skin and anterior nares (nostrils)
Capsule – aids in biofilm formation to colonize medical equipment, causing opportunistic infections.
Enterotoxin – causes Staphylococcal food poisoning, found in cream-based food and processed meats.
Exfoliative toxin – causes skin separation in Staphylococcal scalded skin syndrome.
Toxic shock syndrome toxin (TSST) – leads to high fever, hypotension, shock, and death.
Folliculitis – superficial inflammation at the hair follicle.
Furuncle – deeper inflammation of a hair follicle, can progress to a pustule.
Carbuncle – clusters of furuncles, leading to deeper lesions, can cause death in severe cases.
Impetigo – bubble-like swellings that break and peel away, common in newborns.
Lung – Pneumonia
Bone – Osteomyelitis
Heart – Endocarditis
Blood – Septicemia/sepsis
A strain of Staphylococcus aureus that makes an enzyme called penicillinase, making it resistant to penicillin.
Lives on the skin
Virulence factor: Capsule – causes biofilm formation and colonization of medical devices.
Lives on the skin or sometimes in the vagina
Causes urinary tract infections (UTIs) in sexually active women
Streptococcus agalactiae
Streptococcus pyogenes (Group A Strep or GAS)
Enterococcus faecalis
Skin and throat
Capsule – Protection from immune system cells.
Streptolysin – A species-specific hemolysin causing beta-hemolysis.
Erythrogenic toxin – Can lead to scarlet fever after a strep throat infection.
Hyaluronidase – Degrades connective tissue, contributing to necrotizing fasciitis.
Erysipelas – Infection that progresses to the dermis and subcutaneous layers, causes redness, fever, and pain.
Necrotizing fasciitis – Flesh-eating disease due to degradation of connective tissue, can lead to death.
Streptococcal pharyngitis – Strep throat or tonsillitis with red throat and pus.
Impetigo – Bubble-like swellings that break and peel away, highly contagious.
Rapid strep test .... penicillin
Affects the kidney – Acute glomerulonephritis
Affects the heart – Rheumatic fever
Leads to endocarditis – Rheumatic fever
Can eventually lead to kidney failure – Acute glomerulonephritis
Can be diagnosed by listening for unusual heart sounds – Rheumatic fever
Resides in vagina
Pregnant women are screened late in pregnancy and given antibiotics during delivery to prevent transmission to newborn
Can be transferred to newborns during birth, causing pneumonia, meningitis, permanent damage, or death
Of concern due to VRE (Vancomycin-Resistant Enterococcus)
Causes opportunistic infections after surgery or with the use of catheters
Resides in the large intestine (colon)
Streptococcus pneumoniae
Streptococcus mutans
Streptococcus sanguinis
Streptococcus mutans
Streptococcus sanguinis
Oral cavity
Streptococcus mutans: Forms a biofilm leading to dental plaque and caries.
Streptococcus sanguinis: Forms a biofilm on the heart leading to endocarditis.
A capsule – an important virulence factor for survival in the human body.
M = Meningitis – Fever, stiff neck, headache.
O = Otitis media – Middle ear infection.
P = Pneumonia – Acquired via respiratory droplets or normal flora.
S = Sinusitis – Excessive exudate in the lungs, possibly drowning in secretions.
A strain of Streptococcus pneumoniae that has obtained drug resistance to several antibiotics.
IgA protease – Helps evade the immune system by degrading antibodies.
Hemorrhaging of blood vessels, petechiae or ecchymosis
Discharge from the penis or vagina
Can be transmitted to a newborn
Can cause pelvic inflammatory disease and infertility in women
Can cause gonorrhea
Can be transmitted to cause extragenital infections
Blindness; that is why babies are given antibiotic drops in their eyes at birth
Production of endotoxin can lead to meningococcemia
Hemorrhaging of blood vessels, petechiae or ecchymosis
Second most common cause of bacterial meningitis
More strains are developing drug resistance, limiting treatments
Originally isolated from bed sore infections
Originally isolated in injured military personnel