Microbiology Exam 1 PP 2

What is an abscess?

pus-filled pockets on the skin→ often called pimple (not acne)

What is a furnucle or boil?

large, painful, raised nodular extension of folliculitis into surrounding tissue

What is folliculitis?

type of skin abscess that involves the hair follicle→ (sty when @ eyelid base)

What can cause a abscess/folliculitis?

Staphylococcus aureus

What are two drug resistant strains of abscesses/folliculitis?

1. MRSA

2. VRSA

What is hot tub folliculitis?

small pimples on stomach

due to pseudomonas aeruginosa

appears from 6 hours to 5 days and usually goes away on its own in 7-10 days

A infant comes in with reddening of skin followed by large blisters containing fluid lacking bacteria or WBCs→ withing two days, outer layer of skin peels off in sheets, what is your diagnosis?

Staphylococcal scalded skin syndrome (sometimes mistaken for child abuse)

What can cause Staphylococcal scalded skin syndrome?

staphylococcus aureus

A child of 2-5 comes in with small flattened red patches on face and limbs and have pus-filled vesicles that break and form a thick honey colored, sticky crust (pyoderma), what is your diagnosis?

Impetigo contagiosum

What causes impetigo contagiosum?

Staphylococcus aureus

An elderly person comes in with a fiery red rash with raised borders on their legs. SKin is hot, red and sharply defined, what is your diagnosis?

Erysipelas

What is necrotizing fasciitis?

very serious→ flesh eating bacteria

enters body through skin breaks

starts with big, purplish-red blisters

involves toxemia

50% fatality

What is acne?

caused by propionibacterium acnes which is normal microbiota

opportunistic from sebum blockage

inflamed skin swells over the pore when bacteria infects hair follicle

Is acne a gram - or gram + disease? (TQ)

gram +

A person comes in with an infected cat scratch and has a blister/bump at sight of scratch? What is your diagnosis?

Cat scratch disease

What is the pathogen that causes cat scratch disease?

bartonella henselae

“bart the barn cat is a hen slayer”

Is cat scratch disease gram - or gram +?

gram -

A patient comes in with fever, chills, and a production of purulent matter in an infected wound. The purulent matter has a blue-green pigment (pyocyanin). What’s your diagnosis?

Pseudomonas infection

What is the pathogen for pseudomonas infection?

pseudomonas aeruginosa

Who does pseudomonas infection most commonly affect?

burn victims

A patient comes in a non-itchy spotted rash on trunk and appendages and has developed petechiae after a weekend of going camping. What is your diagnosis?

Rocky Mountain spotted fever

What pathogen causes rocky mountain spotted fever? What is the vector?

rickettsia rickettsii

Tick vector

What are endospores?

defensive strategy against unfavorable conditions

produced by Bacillus and Clostridium

A farmer comes in with a painless, solid, raised nodule that is black and has a crusty ulcer called a eschar. What is your diagnosis?

Cutaneous Anthrax

What pathogen causes cutaneous anthrax?

bacillus anthracis

A farmer comes in with a blackened painful, foul smelling gaseous infection on their foot with gas bubbles. What is the diagnosis?

gas gangrene

MEDICAL EMERGENCY

What is the pathogen associated with gas gangrene?

C. perfringens- in fecally contaminated soil and water

T/F chickenpox is a poxvirus

False- IS NOT

What are two main stages of lesions in poxvirus infections?

1. Pustule= pox

2. Scaring

A patient comes in wiht a fever, headache, and has developed progressive pox lesion on face and body? What is the diagnosis?

Smallpox

When is small pox no longer contagious?

When last smallpox scab falls off (5 weeks)

What is #1 category A bioterrorist threat?

small pox

What makes monkey pox different from small pox?

1. not as many pox lesions

2. Lymphadenopathy

A child comes in with raised, pearl-like, waxy papules, what is your diagnosis?

Molluscum Contagiosum

A pateint comes in with painful slow spreading blisters on face/mouth. What is your diagnosis?

Herpes labialis

What is a key feature of herpes labialis?

latent virus usually in trigeminal ganglia “above the waist herpes”

A patient comes in with slow spreading blisters on finger. What is your diagnosis?

Herpetic Whitlow

What is a key feature of herpetic whitlow?

latent virus in brachial ganglia “above the waist herpes”

A patient comes in with blisters anywhere on the body . What is your diagnosis?

Herpes gladiatorum

What is a key feature of herpes gladiatorum?

latent virus in various ganglia

associated with contact sports

A child comes in with extremely itchy, fluid-filled blisters all over their body. What is your diagnosis?

Chicken pox

Patient comes in with painful, blistering skin rash that follows dermatome. What is your diagnosis?

Shingles

What is a complication of shingles?

Post-herpetic neuralgia

latent virus in spinal DRG

Patient comes in with benign epithelial growths on skin or mucous membranes. What is your diagnosis?

Warts

How are warts spread?

direct contact

autoinoculation

Patient comes in with Koplik’s spots on mucous membrane of mouth and a rash on face. What’s your diagnosis?

Measles

Patient has a rash of flat, pink to red spots. What’s your diagnosis?

Rubella aka German measles

What complication can rubella cause in pregnant women?

Causes congenital rubella syndrome

Patient has a reddening of skin that resembles slap and is aggravated by sunlight. Referred to as “slapped cheek syndrome” What’s your diagnosis?

Erythema infectiosum

T/F Once rash is present, erythema infectiosum is no longer infectious

True

Patient comes in with rose-colored rash, mononucleosis-like symptoms. What’s your diagnosis?

Roseola

Patient comes in with hard, black, irregular nodules on the hair shaft. What’s your diagnosis?

Black piedra

Patient comes in with soft, grayish-white, irregular nodules on hair shaft. What’s your diagnosis?

White piedra

Patient comes in with hypo- or hyper pigmented patches on scaly skin. Can be diagnosed by green color under UV light. What’s your diagnosis?

Pityriasis versicolor

What are the types of dermatophytoses?

1. tinea pedis → athletes foot

2. tinea cruris→ jock itch

3. tinea corporis→ trunk

4. tinea captis→ head

5. tinea unguium→ onychoycosis

Patient comes in with cutaenous sporotrichosis or lymphocutaneous sportrichosis and has recently pricked their finger on a thorn. What’s your diagnosis?

Sporotrichosis

Patient has recently been bit by sand fly and has cutaenous, mucocutaenous, and visceral symptoms. What’s your diagnosis?

Leishmaniasis

Cutaneous leishmaniasis vs visceral?

Cutaneous leishmaniasis: Emerging diseas in deployed military

Visceral leishmaniasis: Kala azar→ most deadly parasitic infection

Patient comes in with intense itching, rash of small red linear bumps. Also burrows and tunnels are present. What’s your diagnosis?

Scabies

A patient shows up with a sudden high fever, stiff neck and severe headaches. What’s your diagnosis?

Bacterial meningitis- MEDICAL EMERGENCY

What are the five types of bacterial meningitis?

1. Neisseria meningitidis (gram -)

2. Streptococcus pneumoniae (gram -)

3. Haemophilus influenzae b (gram +)

4. Listeria monocytogenes (gram -)

5. Streptococcus agalactiae (gram +)

When is streptococcus agalactiae aquired?

acquired during birth

MC in babies less than three months

What age group is associated with haemophilus influenzae b?

MC in children under five typically at 18 months

Who is most at risk for streptococcus pneumoniae?

MC in adults

Who is most at risk for listeria monocytogenes?

transmitted via contaminated food

elderly, babies, and pregnant women are most at risk→ can cross placenta

What branch is characterized by a purple spotted rash and is MC in college students in dorms?

Neisseria meningitidis- MEDICAL EMERGENCY

If a patient presents with skin sores, nerve damage, and muscle weakness, but has a strong immune system what may they have?

Tuberculoid leprosy (nonprogressive)

If a patient presents with skin sores, nerve damage, and muscle weakness, but has a weaker immune system. What’s your diagnosis?

Lepromatous leprosy (progressive)

What is the pathogen for leprosy?

Mycobacterium leprae

How is leprosy spread?

person to person contact

handling or consuming armadillos

What are the two genera that produce endospores?

1. Botulism

2. Tetanus

A baby comes in with flaccid paralysis. What’s your diagnosis?

Botulism (floppy baby syndrome)

What pathogen is in botulism?

clostridium botulinum (gram +)

A patient comes in with a spastic paralysis, tight neck and jaw and has risus sardonicus.What’s your diagnosis?

Tetanus (lockjaw) (gram +)

What pathogen causes tetanus?

clostridium tetani- inhibits GABA

How can infants get tetanus?

infected umbilical stump

A patient comes in the nuchal rigidity, high fever, confusion but is milder than bacterial meningitis. What’s your diagnosis?

Viral meningitis- MC

No adjustment

What pathogen causes viral meningitis?

Enterovirus

A patient is having nonspecific flu like illness. What’s your diagnosis?

Minor polio

A patient is having muscle spasms and back pain. What’s your diagnosis?

Nonparalytic polio

Patient has polio that causes paralysis. What’s your diagnosis?

Paralytic polio

What pathogen causes polio?

Poliovirus

After polio, patients may experience ___ ___ which is crippling deterioration in the motor neuron function of polio-affected muscles

postpolio syndrome

Do we adjust polio?

yes

A patient was recently bitten by a dog and has itching/pian at site of infection. What’s your diagnosis?

Rabies- no adjustment

What animal is the source of most cases of rabies in humans?

Bats

What is the vector for arboviral encephalitis?

mosquito vector

T/F EEE has a higher fatality than WEE

True

EEE, WEE, VEE are all considered __

arbovirus

A patient was recently bitten by a mosquito and has a headache, high fever, neck stiffness, stupor. What’s your diagnosis?

St. Louis encephalitis

A patient just was bitten by a mosquito, 80% of patients are asymptomatic, but this patient has a headache, body aches, and nausea. What’s your diagnosis?

West Nile encephalitis

A patient was bitten by a mosquito recently, they initially had viremia then it became encephalitis and a rash. What’s your diagnosis?

California encephalites

A patient was recently bitten by a tick, they have sore muscles, fever, then encephalitis. What’s your diagnosis?

Tick borne encephalitis- emerging disease

A patient is bitten by a mosquito and is mostly asymptomatic, but 1st trimester of pregnancy is at greatest risk and it can cross the placenta. What’s your diagnosis?

Zika virus infection

Patient has similar symptoms to bacterial meningitis, but it has progressed to loss of vision and coma. What’s your diagnosis?

Cyptococcal meningitis

What pathogen causes cyptococcal meningitis?

cryptococcus neoformans

List the meningitis from MC to least

1. Viral

2. Bacterial

3. Fungal

Patient has a lesion with dead tissue at site of a fly bite, then it progresses to excessive drowsiness and a fever, and finally is invading CNS leading to meningoencephalitis. What’s your diagnosis?

African sleeping sickness (HAT)- MEDICAL EMERGENCY

What pathogen causes African sleeping sickness?

West africa→ Trypanosoma brucei gambiense (MC)

East africa→Trypanosoma brucei rhodesiense

African sleeping sickenss infections are characerized by ___

cyclical waves of parasitemia