Micro J210 Staphylococci

-Normal Flora

-Grape like clusters of gram-positive cocci

-Golden yellow opaque colonies

-White colonies

• -Catalase: converts hydrogen peroxide to water and oxygen. Enzyme
• -Coagulase: coagulase plasma and blood
• -Mannitol fermentation: Mannitol is form of sugar. Organisms that utilize mannitol as a food source will produce acit. Phenol red is the indicator used. It is read at a neutral ph but turns yellow if conditions become acidic.

-Both will positive because an air bubble will be produced due to 02 production

• -aureus: positive, due to clump
• -epi: negative

• -Aureus: positive, gas uses it, it will be yellow for acid production
• -Epi: negative, purple

Both are normal flora of human skin and mucous surfaces

• -Aureus- 20-40%, mostly around nares/mouth. Mosit areas
• -Epi- 100% on the skin

• Staph aureus is a serious pathogen specially in immunocompromised. Top killer in the hospital
• Staph Epi is normally non-pathogenic but an opportunistic pathogen

• -Pyogenic: pus producing, attracts a lot of PMNS to the site of infection
• -the pus must be out to heal

-Whitish-yellow substance produced during inflammatory responses of teh body that can be found in regions of pyogenic bacterial infections

Staph induces pus production and cells of the immune system do not work well within the pus microenvironment

Dead and live PMN, dead and live bacteria, dead tissue debris and fluid, low O2 and low ph

Strictly human to human from nasal mucosa, skin (direct contact)

• -Lipoteichoic acid: surface molecules that help attachment. Thick PG layer
• -Catalase: 2 H2O2 + catalase = H20 + 02
• -Protein A: Surface molecule that binds to Fc portion of IgG, so that IgG cannot bind to anything else

• Exotoxins: Live bacteria
• -Hemolysin: lyses RBC
• -Leukocidin: kills WBC
• -Coagulase: wall off the area of infection, results in low 02 and ph, leading to necrosis. Clots the plasma around lesion
• -Exfoliatin: causes skin peeling SSSS
• -Enterotoxin: Causes food poisoning/vomiting
• -Other exotoxins: occurs in some strains of S. aureus

Staph scalded skin syndrome

-Release of bacteria into the blood

-Bacteria in the blood

Presence of actively growing bacteria or their toxins in the blood (blood poisoning or septic shock)

• -Something in the blood
• Examples: meningococcemia, toxemia, hyperlipidemia

-Impetigo, boil, and furuncle/carbuncle

• -A contagious skin infection taht usually produces blisters or sores on the face (mostly), sometimes hands
• -Most common skin infections among kids of low hygiene
• -3rd world countries
• -Superficial staph

• -folliculitis, skin abscess
• -Infection of hair follicle
• -Pus filled lumps that are tender, warm and/or painful

• -Abscess larger than a boil, usually back of the neck
• -Require surgical draining
• Furuncle: acute, round firm, tender, circumscribed, perifollicular staph infection that usually presents as central pus area
• -Carbuncle: two or more confluent furuncles with separate heads

• -Usually caused by staph aureus
• -They rarely require hospitalization
• -They may respond to local treatment
• -Recurrence may be prevented by decreasing staph aureus carriage

• -New borns
• -Umbilican stump infection (omphalitis) may be one of the sites of infection which leads to SSSS
• -Not serious, self-limiting, happens in low hygiene deliveries

-Exfoliatin toxin: released by S. Aureus strains taht are infected with a virus that has the genetic information for production of toxin

-Screen the virus within the Exfoliation-secreting strains of S. aureus (phage typing)

• -An exotoxin that affects lining of GI tract
• -Some strains of S. aureus release this toxin inot the food

• -Projectile vomiting: Toxin has direct neural effect in the brain cetners
• -Toxin is a superantigen: stimulate T cells nonspecifically
• -most common type of food poisoning in US
• -Staph in food releasing toxins in the food then we eat that food

-Cytokines released nonspecifically presenting cells

-Processed meats, chicken, creams (desserts), mayonnaise-containing dishes

Person with lesions on hand prepare the food, contaminated food sits at room temp for hours, bacteria grow and release toxin within the food. Person consumes the toxin contaminated food

Bacteria die in acid stomach, toxin is acid stable and enters the blood

- 4 hours

• -None since bacteria are not causing the problem
• -Self-limiting conditions. just treat the symptoms (fluid replacement)

• -Bone marrow inflammation.
• -many different types of bacterica can cause this, however sstaph aureus most common
• -May require amputation

• -Limb may be very painful, especially when it is moved
• -Fever and the skin over the painful limb may be swollen, hotter and redder than surrounding areas
• -General ill feeling
• -If the osteomyelitis has been present for some time, and there is a break in the skin, there may be some pus discharge from the area

• - Pneumonia
• -Abscess formation in lungs of immunocompromised
• -Rare but highly fatal
• -Gram stain of teh sputum smear shows staph aureus
• -Gram positive, usually affect the debilitated, elderly or immunocompromised, and responsible for nosocomial infections acquired during lengthy hospital stay

• -Toxic shock syndrome
• -1978-80, deaths traced to use of rely tampoms.
• -Staph grew on the tip of the tampons and released toxin (Toxin-1 or TSST-1)
• -Toxin in blood caused the condition
• -Superantigen
• -results in septic shock with multiple organ failures and possible death

• -Flu-like symptoms such as fever, chills, muscle ches, nausea, vomiting and diarrhea
• -Dehydration and decreased urine output
• -Hypotension with weak and rapid pulse
• -confusion, disorientation or other mental changes (alarming, and reason they do not seek medical attention)
• -Swelling in hands, feet, and ankles
• -Red rash, taht covers the whole body, followed by peeling skin (may be difficult to see in dark-skinned individuals) (sunburn like)
• -Strawberry tongue

• -non-menstrual toxic shock syndrome occur in males and females of all age groups that are usually associated with localized or systemic infections
• -In femals use of contraceptive sponges, diaphragms or intrauterine devices

• -No bacteria in blood but treat with antibiotic to destroy source of bacteria in the wound
• -remove foreign object and change tampons frequently

• Very stable to drying and heat
• Enterotoxin is heat stable (dont save the food)

• -No because staph hides itself from cells of immune system
• -Wall off the area of infection with coagulase
• -Releases toxins that paralyze immune system (Toxic shock) kills leukocytes
• -Some people are more susceptible than others (30% recurrence)

• -An increasing number of patients are being seen with skin infections by staph aureus taht are resistant to many antibiotics
• -MRSA (Super bug, 1970)
• -PRSA- 1942
• -VISA- 1997
• -VRSA-2000

• -Emergence of VRSA
• -No vaccine
• -New innovative phage therapy (certain phages destorying virus staph)

• -MRSA
• Symptoms: Minor skin problems, deep abscesses, can reach bone marrow, joints, bloodstream, major organs, can lead to death
• Problem: bacteria has evolved to survive common antibiotics
• Risk environments: hospitals, long-term care facilites, sporting facilites/equipment, and crowded, unsanitary living conditions

• -Infections are considered nosocimal if they first appear 48 hours or more after hospital admission or within 30 days after discharge.
• -Contact, hospital personnel or devies
• -Airborne
• -Common vechicle: contaminated equipments (Catheters)

• -Brought forth by a healer
• Example: osteomyelitis following a bone surgery

Advanced age, underlying disease, severity of illness, transplantation, GI surgery, exposure to medical devices, heavy exposure to antimicrobial therapy, prolonged hospital stay, interinstituational transfer of a patient

• -Complex aggregation of microorganisms marked by the excretion of a protective and adhesive matrix
• -Microbial biofilms develop when microorganisms irreversibly adhere to a submerged surface and produce extracelluar polymers that faciliate adhesion adn provide a structural matrix
• Example: dental plaque

• -Normal flora
• -Have emerged as a major nosocomial pathogen associated with infections mediated by implanted medical devices

• -Hand washing after touching the patient and items contaminated by bodily fluids, secretions, excretions or objects
• -Wearing gowns
• -Appropriate disposal of items taht came in contact with the infected patient and appropriate handing of laundry
• -Infected patients should be placed in isolation in a side-room to limit the spread of infection

-Portal of entry, susceptible host, infectious agent, reservoirs, portal of exit, means of transmission, repeat

• -Flow chart
• Catalase test, coagulase test, pattern of hemolysis on blood agar, optochin test, bacitracin sensitivity test, CAMP test