Staphylococcus aureus is a bacterium that can cause various infections in humans, from minor skin infections to life-threatening conditions like sepsis and pneumonia. It is a common cause of boils and abscesses. Some strains have developed resistance to antibiotics like methicillin and vancomycin, making treatment more difficult. S. aureus is found naturally on the skin but can enter the body through cuts or medical devices and cause infection. Proper antibiotic treatment depends on determining if the strain is resistant to certain drugs.

1. Submitted By: SAQIB KHAN
REG N0#: FA16-PHM-060
Serial No#: 20
Class PHM-3B
Topic: Staphylococcus Aureus
Date of Submission: 10/11/2017
Submitted to: Mr. Tariq Ismail

2.  A bacterium that forms yellow-pigmented colonies that grows with oxygen
(aerobically) or without oxygen (anaerobically).
 S. aureus is the cause of toxic shock syndrome that results in high fever,
vomiting and sometimes death. It produces enter toxins, which affects
intestinal mucosa. S. aureus is also the cause of boils (skin abscess), impetigo
(pus-filled blisters on the skin), styes (an infection at the base of an eye lash),
pneumonia, osteomyelitis, acute bilateral endocarditic (inflammation of the
internal membranes of the heart) and scalded skin syndrome in very young
children that causes skin to strip off (denude) due to an exfoliative toxin.

3.  Non motile
 Non–spore-forming
 Non encapsulated
 Catalase - producing
 Oxidase: negative
 Glucose fermenters
 Primarily aerobic, some facultatively anaerobic

4.  Approximately 33 species
 ~15 species associated with humans
 Staphylococcus divided into coagulase positive & coagulase negative categories
 Inhibited by high bile salt concentration
 Some are ß-hemolytic
 Colony morphology: buttery looking, cream or white colored

5. Methicillin-resistant Staphylococcus aureus (MRSA) is a bacteria that is
resistant to many antibiotics. Staph and MRSA can cause a variety of
problems ranging from are skin infections and sepsis to pneumonia to
bloodstream infection.
 Resistant to numerous antibiotics including methicillin, amoxicillin,
penicillin, and oxacillin. This resistance makes it challenging to treat.

6. Vancomycin intermediate staphylococcus aureus (VISA) infection is a condition
caused by bacteria (germs). This infection occurs when bacteria, called
Staphylococcus aureus or Staph, becomes resistant (not killed) to the
antibiotic medicine vancomycin. The Staph bacteria are commonly found on
the skin and in the nose. A person may carry the Staph bacteria but not get
infected or sick. When Staph causes an infection, such as pimples or boils,
mild antibiotics can easily kill them. Caregivers usually give vancomycin
only after the mild antibiotics do not work.

7.  It causes following disease like,
 Skin infections
 Food poisoning
 Bone and joint infections
 Bacteremia
 Biofilms
 Animal infections
 Endocarditis
 Cutaneous infections

8.  Cutaneous infections:
(folliculitis, e.g., stye and acne; furuncles): usually an
intense, localized painful inflammatory reaction
that undergoes central suppuration and heals
quickly when the pus is drained.
 Wound infections:
can occur after surgery or trauma, may involve skin,
bone (osteomyelitis from an open fracture) or
meninges (meningitis from skull fracture.)

9.  Bacteremia:
Mostly results from surgery or continued use of intravascular
catheters. Bacteria may spread to other body sites and cause
endocarditis, hematogenous osteomyelitis and septic arthritis,
meningitis, and pulmonary infection (hematogenous pneumonia,
and empyema.)
 Staphylococcal scalded skin syndrome
(SSSS or Ritter disease): forming large bullae (cutaneous blisters)
with clear fluid that contains no bacteria or leukocytes. Spreads
rapidly. Occurs much more often to neonates and young children.

10.  Endocarditis:
caused by infection of native (rarely) or prosthetic heart valves
 Prosthetic joint infections:
localized pain and failure of the artificial joint. Systemic signs are not prominent.
Reinfection of new joint is increased in such patients.
 Biofilms
 S. aureus is often found in biofilm formed on medical devices implanted in the body
or on human tissue. Remarkable it is commonly found with another pathogen,
Candida albicans, forming multispecies biofilms. The latter is suspected to help S.
aureus penetrate human tissue. A higher mortality is linked with multispecies
biofilms.

11.  Penicillinase-resistant penicillins
 Flucloxacillin
 dicloxacillin
 first generation cephalosporins
 Cefazolin
 Cephalothin cephalexin
 Clindamycin
 Lincomycin
 Erythromycin

12.  For Vancomicin-resistant Staphylococcus aureus:
 Gentamicin
 Rifampin
 Beta-lactam antibiotics
 Linezolid
 For MRSA infections may include
 clindamycin
 tetracycline drugs - doxycycline and minocycline
 trimethoprim and sulfamethoxazole
 rifampin
 linezolid