Microbiology Exam 4. Ch 21 Study Guide

Front 1

List examples of normal microbiota on the skin

Back 1

The skin contains relatively large numbers of gram-positive bacteria such as staphylococcus and micrococci. Moist areas such as the armpits have increased numbers of bacteria.
Included are gram-positive pleomorphic rods called diphtheriods...can cause acne. They are typically. Anaerobic and inhabit hair follicles. Their growth is supported by sebum oil glands.
Malassezia is a yeast that is responsible for dandruff

Front 2

Understand way that pathogens can invade the skin

Back 2

The hair follicles, sweat gland ducts and oil gland ducts in the dermis provide passageways for microorganisms to travel and enter
Sweat and sebum contains enzymes that kill most bacteria, though, some find it nutritive and can survive with it

Front 3

State the general locations and ecological roles of it's members

Back 3

Epidermis: is the thin outer portion composed of several layers of epithelium
Stratum corneum is the outermost layer of the epidermis and contains waterproofing keratin .
The dermis is the inner, thicker portion, composed of connective tissue
Hair follicles
Sweat gland releases sweat/perspiration that provides moisture to some nutrients but also contains salt and lysosomes oil glands secrete sebum. A mixture of lipids, proteins and salts, which keeps skin and hair from drying out

Front 4

Differentiate between staphylococcus and streptococci

Back 4

Staphylococcus exists in grape like clusters
Streptococci exists in chains

Front 5

Macules

Back 5

Flat, reddened lesions

Front 6

Vesicles

Back 6

Small fluid filled lesions

Front 7

Papules

Back 7

Raised lesions (no pus)

Front 8

Pustules

Back 8

Raised lesions that contain pus

Front 9

Exanthem

Back 9

A skin rash that arises from disease conditions

Front 10

Macular rashes: measles (rubeola)

(viral diseases)

Back 10

Pathogen: measles virus
Portal of entry: respiratory tract
Symptoms: skin rash of reddish macules first appearing on face and spreading to trunk and extremities
Method of transmission: aerosol
Treatment: no treatment; preexposure to vaccine

Extremely contagious viral disease that is spread by the respiratory route.
Infectious before symptoms appear so quarantine is not effective
Vaccine MMR. Has nearly eliminated measles in the USA.
More infectious than small pox.
Infection begins in the upper respiratory system and incubate for 10-12 days, than macular rash appears along with cold symptoms On body and in oral cavity (kopliks spots, small red spots with central blue white specs
Extremely dangerous to children and old people.
Measles sufferers may have secondary infections such a encephalitis and middle ear infections

Front 11

Macular rashes: Rubella (German measles)

(viral diseases)

Back 11

Pathogen: rubella virus
Portal of entry: respiratory tract
Symptoms: mild mascular disease with. Rash resembling measles, but less extensive and disappearing in three days or less
Method of transmission: aerosol
Treatment: no treatment; preexposure to vaccine

Milder than measles and often goes undetected.
A macular rash of small red spots and A light fever are usual symptoms. Complications are rare but encephalitis occurs in some cases.
Virus is transported by the respiratory route and incubates for 2-3 weeks.
Rubella during first trimester of pregnancy is call congenital rubella syndrome. Has seriousness side effects for baby including metal retardation, death, heart defects, deafness etc.

Front 12

Macular rashes: fifth disease (erythmema infectiosum)

(viral diseases)

Back 12

Pathogen: human parvovirus b19
Portal of entry: respiratory tract
Symptoms: mild disease with w macular facial rash
Method of transmission: aerosol
Treatment: none

Name derived because it is the fifth name on a list of otherwise well known rashes.
Symptoms are similar to mild influenza but with s distinctive "slapped cheek" facial rash that slowly fades.

Front 13

Muscular rashes: candidiasis

(fungal diseases)

Back 13

pathogen: candida albicans
Portal of entry: skin; mucous membranes
Symptoms: macular rash
Method of transmission: direct contact; endogenous infection
Treatment: miconazole, clotrimozole topically

Overgrowths by C. Albicans. Caused by overgrowth of yeast that is immune to phagocytosis and not affected by antimicrobial drugs.
Cause a whitish overgrowth in the oral cavity called thrush.
Also very common cases of vaginitis
Idv. with HIV are prone to infections.
Obese people or diabetics, the areas of the skin with. Oe moisture become infected and skin becomes bright red.
Treated topically with ointment

Front 14

Vesicular and pustular rashes: impetigo

(bacterial diseases)

Back 14

Pathogen: staphylococcus aureus.
Portal of entry: skin
Symptoms: vesicles on skin
Method of transmission: direct contact fomites
Treatment: topical antibiotics

Front 15

Vesicular and pustular rashes:
Small pox (variola)
(viral diseases)

Back 15

Pathogen: smallpox variola virus
Portal of entry: respiratory tract
Symptoms: postules that may be nearly confluent with skin
Method of transmission: Aerosol
Treatment: none

Front 16

Vesicular and pustular rashes:
Chickenpox (varicella)
(viral diseases)

Back 16

Pathogen: varicella-zoster virus
Portal of entry: respiratory tract
Symptoms: vesicles in most cases confined to the face, throat and lower back.
Method of transmission: aerosol
Treatment: acyclovir for immunocomprimised patients; preexposure vaccine.

Front 17

Vesicular and pustular rashes:
Shingles (herpes-zoster)
(viral diseases)

Back 17

Pathogen: varicella-zoster virus
Portal of entry: endogenous infections of peripheral nerves
Symptoms: vesicles typically on onside of the waist, face, scalp, or upper chest.
Method of transmission: recurrence of latent chickenpox vaccine.
Treatment: acyclovir preventative vaccine.

Front 18

Vesicular and pustular rashes:
Herpes simplex
(viral diseases)

Back 18

Pathogen: herpes simplex virus type 1
Portal of entry: skin, mucous membranes
Symptoms: vesicles around the mouth; can also affect other areas of the skin and mucous membranes
Method of transmission: initial infection by direct contact; recurring latent infection
Treatment: acyclovir

Front 19

Patchy redness and pimple-like conditions: Folliculitus

(bacterial diseases)

Back 19

Pathogen: staphylococcus aureus
Portal of entry: hair follicle
Symptoms: infection of hair follicle
Method of transmission: direct contact fomites; endogenous infection caused by host microbiota
Treatment: draining of pus; topical antibiotics

Front 20

Patchy redness and pimple-like conditions:
Toxic shock syndrome
(bacterial diseases)

Back 20

Pathogen: staphylococcus aureus.
Portal of entry: surgical incisions
Symptoms: rash, shock, fever
Method of transmission: endogenous infections caused by microorganisms already part of host microbiota
Treatment: antibiotics, depending on sensitivity profile

Front 21

Patchy redness and pimple-like conditions: Necrotizing fascitis

(bacterial diseases)

Back 21

Pathogen: streptococcus pyrogenes
Portal of entry: skin abrasions
Symptoms: extensive soft tissue destruction
Method of transmission: direct contact
Treatment: surgical tissue removal, broad spectrum antibiotics

Front 22

Patchy redness and pimple-like conditions: Acne

(bacterial diseases)

Back 22

Pathogen: propionibacterium acnes
Portal of entry: sebum channels
Symptoms: inflammatory legions originating with accumulations of sebum that rupture a hair follicle
Method of transmission: direct contact
Treatment: beznzoyl peroxide, isotretinoin

Front 23

Patchy redness and Pimple-like conditions:
Warts
(viral diseases)

Back 23

Pathogen: papillomavirus
Portal of entry: skin
Symptoms: a horny projection of the skin formed by the proliferation of cells
Method of transmission: direct contact
Treatment: may be removed by liquid nitrogen cryotherapy, electrodessication, acids, lasers

Front 24

Patchy redness and Pimple-like conditions:
Ringworm (tinea)
(fungal diseases)

Back 24

Pathogen: microsporum, trichophyton, epidermophyton spp.
Portal of entry: skin
Symptoms: skin lesions of highly varied appearance; on scalp may cause local loss of hair
Method of transmission: direct contact fomites.
Treatment: griseofulvin (orally); miconazole, clotrimazole (topically)

Front 25

Patchy redness and Pimple-like conditions:
Sporotrichosis
(fungal diseases)

Back 25

Pathogen: sporothrix, schenkii
Portal of entry: skin abrasions
Symptoms: ulcer at site of infection spreading into nearby lymphatic vessels
Method of transmission: soil
Treatment: potassium iodide solution (orally)

Front 26

Patchy redness and Pimple-like conditions:
scabies
(parasitic infestations)

Back 26

Pathogen: sarcoptes scabiei
Portal of entry: skin
Symptoms: papules, itching
Method of transmission: direct contact
Treatment: gamma benzene hexachloride, permethrin (topically)

Front 27

Patchy redness and Pimple-like conditions:
pediculosis (lice)
(parasitic infestation)

Back 27

Pathogen: pediculus humanus capitus
Portal of entry: skin
Symptoms: itching
Method of transmission: primarily direct contact; possible fomites such as bedding and combs
Treatment: topical insecticide preparations

Front 28

Microbial disease of the eyes:
Conjunctivitis
(bacterial diseases)

Back 28

Pathogen: haemophilus influenzae
Portal of entry: conjunctiva
Symptoms: redness
Method of transmission: direct contact; fomites
Treatment: none

Front 29

Microbial disease of the eyes:
Ophthalmia neonatorum
(bacterial diseases)

Back 29

Pathogen: neisseria gonorrhoeae
Portal of entry: conjunctiva
Symptoms: acute infection with pus formation
Methods of transmission: through birth canal
Treatment: prevention: tetracycline, erythromycin, or providone-iodine

Front 30

Microbial disease of the eyes:
Conjunctivitis
(viral diseases)

Back 30

Pathogen: adenovirus
Portal of entry: conjunctiva
Symptoms: redness
Method of transmission: direct contact
Treatment: none

Front 31

Microbial disease of the eyes:
Ancanthamoeba keratitis
(protozoan disease)

Back 31

Pathogen: acanthamoeba spp
Portal of entry: corneal abrasion; soft contact lenses may prevent removal of by blinking
Symptoms: Keratitis
Method of transmission: contact with fresh water
Treatment: topical propaminide isethionate or miconazole; corneal transplant or eye surgery may be required.