Share chapter 21 micro
Save to Folder
What perspiration factors discourage microbial growth?
salt in sweat inhibits many microorganisms; lysozyme is capable of breaking down the cell walls of certain bacteria and antimicrobial peptides
Are skin bacteria more likley to be gram (-) or gram (+) ?
Gram (+)
What bacterial species features the virulence factor M protein?
Streptococcal sp.
How did the odd naming of "fifth disease" arise?
It is the fifth disease on a list of skin rash diseases (Measles, scarlet fever, rubella, Filatov Dukes' disease, Erythema infectiosum or fifth disease)
Transmitted via the respiratory route, moves into the bloodstream, and infects the skin; Two forms of the disease – 2 forms: Variola major has 20-60% mortality – Variola minor has <1% mortality
poxvirus (orthopoxvirus)
Virus- Mild flulike symptoms; “slapped-cheek” facial rash; also known as erythema infectiosum
parvovirus (Human parvovirus B19)
What do Chlamydia trachomatis, adenovirus, Haemophilus influenzae and N. gonorrhea all have in common?
They are all causative agents of conjunctivitis
Favors growth in moist environments, rod-shaped, produces pyocyanin, Produces exo- and endotoxins; grows in biofilms resistant to many types of disinfectants and antibiotics.
Pseudomonas aeruginosa
You are examining a scraping of an infected cornea under the brightfield microscope and see eukaryotic cells. This is probably a case of
Acanthomoeba keratitis.
What is the most common type of subcutaneous mycosis in the United States?
sporotrichosis; forms small ulcer on the hands and enter the lymphatic system in the area and forms more similiar lesions.
You have a culture of bacteria that you suspect is either Staphylococcus aureus or Streptococcus pyogenes. Is there any morphological difference between the two?
Yes. Microscopically, S. aureus typically forms gram-positive cocci in clusters, whereas S. pyogenes forms gram-positive cocci in chains.
How do sporotrichosis and tineas differ?
sporotrichosis is a subcutaneous fungal infection where as tineas in a cutaneous fungal infection.
An eight-year-old girl has scabs and pus-filled vesicles on her face and throat. Three weeks earlier she had visited her grandmother, who had shingles. What infection does the eight-year-old have?
chickenpox
Scabies is a skin disease caused by a
mite
What test could you preform to differentiate between staphylococcal skin infections?
Coagulase test
Several individuals who frequently swim at a local community pool have developed infections. Some have developed a skin rash and others have developed a painful infection of the outer ear canal. What is the most likely etiologic agent?
Pseudomonas aeruginosa
