DPT - Microbiology II (Gram +ve cocci) - Genus Staphylococcus

DPT - Microbiology II (6th semester)

1. PATHOLOGY & MICROBIOLOGY - II by, Miss Areesha Ahmad Lecturer Microbiology B.Sc (H), M.Sc , M.Phil and Ph.D scholar (Microbiology) Medical Microbiology Gram + ve c occi Genus Staphylococcus

2. Important Properties

3. Transmission Humans are the reservoir for staphylococci. The nose is the main site of colonization of S. aureus , People who are chronic carriers of S. aureus in their nose have an increased risk of skin infections caused by S. aureus . The skin , especially of hospital personnel and patients is also a common site of S. aureus colonization. Hand contact is an important mode of transmission. Staphylococcus aureus is also found in the vagina of approximately 5% of women . Additional sources of staphylococcal infection are shedding from human lesions such as towels and clothing contaminated by these lesions.

4. Pathogenesis Staphylococcus aureus causes disease by producing; Enzymes Toxins

5. (degradation)  

6. Clinical Findings

7. (Area of the body between the anus and the vulva in females) (Last section of the large intestine, and it connects the colon to the anus) (The tube that lets urine leave your bladder and your body ) (The lower, narrow end of the uterus (womb) that connects the uterus to the vagina (birth canal) .

8. Acute pyelonephritis : a bacterial infection causing inflammation of the kidneys. Cystitis : an infection of the bladder that almost always follows (is secondary to) bacterial infection in the urine. Urethritis: an inflammation of the urethra. Prostatitis: a disorder of the prostate gland usually associated with inflammation

9. Dysuria : sensation of pain and/or burning,

10. Laboratory Diagnosis Smears from staphylococcal lesions. Cultures of S. aureus typically yield golden-yellow colonies that are usually β- hemolytic. Staphylococcus aureus is coagulase positive. Mannitol -salt agar is a commonly used screening media for S. aureus . Staphylococcus aureus ferments mannitol , which lowers the pH causing the agar to turn yellow whereas S. epidermidis does not ferment mannitol and the agar remains pink. Cultures of coagulase-negative staphylococci typically yield white colonies that are nonhemolytic

11. Treatment

12. Prevention There is no vaccine against staphylococci. Cleanliness , frequent handwashing , and aseptic management of lesions help to control spread of S. aureus . Persistent colonization of the nose by S. aureus can be reduced by intranasal mupirocin or by oral antibiotics, such as ciprofloxacin or trimethoprim- sulfamethoxazole , but is difficult to eliminate completely. Shedders may have to be removed from high-risk areas (e.g., operating rooms and newborn nurseries ). Cefazolin is often used preoperatively to prevent staphylococcal surgical-wound infections.