Microbiology chapter 21 OpenStax multiple choice an

Sebaceous

Glands produce a lipid-rich substance that contains proteins and minerals and protects the skin.

Dermis

The ___ contains living cells, is vascularized, and lies directly above the hypodermis

coagulase-positive

Staphylococcus aureus is most often associated with being

Streptococcus pyogenes

M protein is produced by

Trachoma

___is a major cause of preventable blindness that can be reduced through improved sanitation.

Staphylococcus epidermidis

____is frequently associated with nosocomial infections transmitted via medical devices inserted into the body.

human papillomavirus

Warts are caused by

Herpes simplex virus 1

___can spread to the eye to cause a form of keratitis.

herpes simplex viruses

Cold sores are associated with

Viral conjunctivitis

____is usually self-limiting but is most commonly treated with ganciclovir if medical treatment is needed.

viral conjunctivitis

Adenoviruses can cause

Tinea capitis

_____is a superficial fungal infection found on the head.

visualize the fungus

A health-care professional would use a Wood’s lamp for a suspected case of ringworm to

all fungi

Sabouraud dextrose agar CC is selective for

sporotrichosis is itraconazole

The first-line recommended treatment for

Acanthamoeba infection

Swimming in a lake while wearing contact lenses is most likely to cause an

travels through the conjunctiva

The parasitic Loa loa worm can cause great pain when it

the individual was exposed to Loa loa at some point

A test for Loa loa antibodies indicates that

chlorhexidine and polyhexamethylene biguanide

Acanthamoeba keratitis is commonly treated with a combination of

stratum corneum

The ________ is the outermost layer of the epidermis.

conjunctiva

The mucous membrane that covers the surface of the eyeball and inner eyelid is called the ________.

pus

A purulent wound produces ________.

roseola

Human herpesvirus 6 is the causative agent of ________.

sporotrichosis

The most common subcutaneous mycosis in temperate regions is ________.

Loa loa

Eye worm is another name for ________.

cornea

The ________ is the part of the eye that is damaged due to Acanthamoeba keratitis.

Protection, Strength, and durability

What is the role of keratin in the skin?

• Lysozyme Activity: Tears contain the enzyme lysozyme, which breaks down the cell walls of certain bacteria, preventing bacterial growth and invasion.

• Flushing Action: The act of tearing helps wash away debris, microorganisms, and other potentially harmful particles from the surface of the eye, reducing the risk of infection.

What are two ways in which tears help to prevent microbial colonization?

contribute to the destruction of immune cells and the buildup of infected material

How are leukocidins associated with pus production?

• Staphylococci are catalase-positive, meaning they produce the enzyme catalase that breaks down hydrogen peroxide into water and oxygen.

• Streptococci are catalase-negative, meaning they do not produce this enzyme.

What is a good first test to distinguish streptococcal infections from staphylococcal infections?

• Bacterial Conjunctivitis: Caused by bacteria (e.g., Staphylococcus), with symptoms of redness, swelling, and thick pus discharge. It’s highly contagious and requires antibiotics for treatment.

• Viral Conjunctivitis: Often caused by adenovirus, with symptoms of redness, watery discharge, and often flu-like symptoms. It’s also contagious but usually resolves on its own without specific antiviral treatment.

Compare and contrast bacterial and viral conjunctivitis.

Candida species, Cryptococcus neoformans, Malassezia species, Rhodotorula species

What yeasts commonly cause opportunistic infections?