Staphylococci BMLT Microbiology
Clinical significance Of Staphylococci BMLT
Staphylococci can cause many types of infections. (1) S aureus causes skin lesions (abscesses, styes) and local abscesses on some sites. (2) S aureus causes serious infections, such as osteomyelitis and endocarditis and more serious skin diseases (furunculosis). (3) S aureus is a major cause of hospital-acquired (nosocomial) infections of surgical wounds and, through S epidermidis, causes infections associated with internal medical equipment. (4) S aureus causes food poisoning by releasing enterotoxins from food. (5) S aureus causes toxic shock syndrome by releasing superantigens into the bloodstream. (6) S saprophiticus causes urinary tract infections, especially in girls. (7) Other types of staphylococci (S lugdunensis, S haemolyticus, S warrneri, S schleiferi, S intermedius) are rare viruses.
Structure of Staphylococci BMLT
Staphylococci are Gram-positive cocci 1μm in diameter. Build collections
Classification of Staphylococci BMLT
S aureus and S intermedius are coagulase positive. All other staphylococci have a negative coagulase. They are salt tolerant and usually hemolytic. Diagnosis requires biotype analysis.
Pathogenesis Of Staphylococci BMLT
S aureus reveals many potential virulence factors. (1) Excess protein promotes connective tissue. (2) Potential substances that prevent phagocytosis (capsule, a protein that binds immunoglobulin A). (3) Toxins that damage the underlying tissues and cause symptoms. Coagulase-negative staphylococci are generally harmless and present a few risk factors. S epidermidis easily colonized implanted devices.
Treatment of Staphylococci BMLT
Out-of-hospital infections can usually be treated with act-lactam-resistant penicillinase. Infections found in the hospital are usually caused by antibiotic-resistant strains and can only be treated with vancomycin