Microbiology Final Exam

an open sore on an internal or external surface caused by a break in the skin or mucous membrane

ulcer

which hepatitis is characterized by
- the most milder and shorter-term
- vague, flulike symptoms
- darkened urine
- not oncogenic
- uncomplicated recovery
- transmitted by the fecal-oral route, vehicle

Hep A

which hepatitis is characterized by
- fever, chills, malaise, anorexia, abdominal discomfort, diarrhea, and nausea
- transmitted by blood, semen, vaginal fluids, vertical
arthritis may occur
- can be serious and life-threatening
- complete liver regeneration and restored function in most patients
- small # of patients develop chronic liver disease
- sometimes leads to hepatocellular carcinoma
- vaccine exists and is required for healthcare workers

Hep B

which hepatitis is characterized by
- "silent epidemic"
- blood transmission, vertical
- more likely to become chronic
- most common cause of liver cancer in US
- no vaccine

Hep C

What does ANUG stand for?

acute necrotizing ulcerative gingivitis

What are the causes of ANUG?

poor oral hygiene altered host defenses prior gum disease

what is another name for ANUG?

trench mouth

What are some symptoms of ANUG?

rapid advancement into periodontal tissues
severe pain, bleeding, pseudomembrane formation, necrosis

What is the most destructive peridontal disease?

ANUG

What are the possible causative agents of ANUG?

synergistic infections by T. vincentii, P. intermedia, and Fusobacterium

What are the two normal biota of the female reproductive tract we discussed in class?

Lactobacillus species
Candida albicans

What is the vaccine for HPV? What kind of vaccine is it?

Gardasil: non-infectious recombinant vaccine

What are some causes of sinusitis?

allergies, infections, or structural issues

What is a tubercle?

granulomas formed during tuberculosis infection

What are the virulence factors of Helminths? (3)

- specialized mouthparts
- enzymes
- cuticle or other covering

What are some causes of Otitis Media?

Streptococcus pneumoniae
Haemophilus influenzae
other bacteria, viruses, fungi

What are the stages of syphillus?

primary, secondary, latent, tertiary

What happens in the primary stage of syphilis?

- appearance of painless "hard" chancre
- lymph nodes draining the affected region become enlarged and firm
- chancre is filled with spirochetes
- chancre heals spontaneously in 3 to 6 weeks

What happens in the secondary stage of syphilis?

- 3 to 6 months after healing
- lymphadenopathy
- skin rash
- spirochete present
- often loss of hair
- disappears spontaneously in a few weeks

What happens in the latent stage of syphilis?

- antibodies present, but no treponema detected
- lasts up to 20 years

What happens in the tertiary stage of syphilis?

- rare today due to antibiotics
- cardiovascular syphilis
- gummas
- neurosyphilis

What is lymphadenopathy?

enlarged lymph nodes

What are gummas?

painful swollen tumors in the liver, skin, bone, and cartilage (noncancerous)

What are symptoms of neurosyphilis?

causes severe headaches, convulsions, blindness, dementia

What can untreated Streptococcus pyogenes lead to? (4)

necrotizing fasciitis
scarlet fever
rheumatic fever
glomerulonephritis

What is rheumatic fever characterized by?

joint inflammation, heart valve damage

What is glomerulonephritis?

kidney damage due to antigen-antibody deposits in glomeruli

What is the toxin in scarlet fever?

erythrogenic toxin

What is a pseudomembrane?

formed on tonsils and pharynx: consisting of bacterial cells, fibrin, lymphocytes, and dead tissue cells

When is a pseudomembrane formed?

in cases of Diptheria

Is Diphtheria an infection of the upper or lower respiratory tract?

upper

What are the symptoms of diptheria?

sore throat
lack of appetite
low grade fever
blocked airways

What can the exotoxin of Diptheria cause?

myocarditis
neuritis

How is diptheria prevented?

DTaP vaccine

How is diphtheria transmitted?

respiratory droplets

What is extrapulmonary TB?

M. tuberculosis infection outside of the lungs

Who is most commonly affected by extrapulmonary TB?

immunosuppressed patients and young children

What organs are most commonly involved in extrapulmonary TB?

- regional lymph nodes
- kidneys
- long bones
- genital tract
- brain
- meninges

What does Legionella bacteria cause?

Legionnaire's Disease

What disease ravaged Philadelphia in 1976?

Legionnaire's Disease

Where is Legionella found?

water supplies, pond, tap, cooling towers, supermarket vegetable sprayers, hotel fountains

How is Legionella transmitted?

aerosals

What is the reservoir for Hantavirus Pulmonary syndrome?

deer mouse

What does GI stand for?

gastrointestinal

What is the most common bacterial cause of diarrhea?

Campylobacter

How does the campylobacter multiply?

burrow into the wall of the ileum

What kind of bacterium is C. jejunji?

curved gram negative

What autoimmune disorder can be caused by Campylobacter?

Guillain-Barre syndrome

What can Guillain-Barre syndrome lead to?

acute paralysis

What disease is characterized by rice water stools?

cholera

What does norovirus cause?

acute gastroenteritis

How is norovirus transmitted?

fecal-oral route

Who does norovirus infect?

primarily adults

What disease is known for epidemic outbreaks in schools and on cruise ships?

norovirus

What can shiga toxin cause?

- intense inflammation of and damage to intestine
- bleeding/ulceration

What is the causative agent of cholera?

Vibrio cholerae (bacterium)

What does the cholera toxin cause?

causes secretion of water/electrolytes into the intestine

Where is Vibrio cholerae found?

contaminated water

What are the cellular characteristics of Clostridium difficile?

gram positive endospore forming rod

Is clostridium difficile part of the normal microbiota?

yes, making it ntibiotic resistant

What is the role of pseudomembranes when it comes to clostridium difficile?

they slough off and left untreated eventually perforate the intestine

When does Clostridium difficile infection occur?

it is able to superinfect the large intestine when broad spectrum antibiotics have disrupted normal biota

What toxins are produced by Clostridium difficile?

Toxin A: enterotoxin
Toxin B: cytotoxin

What do toxins A and B cause in Clostridium difficile infection?

necrosis of intestinal wall

What are dental caries?

cavities

What are the causative agents of dental caries?

S. mutans and S. sobrinus

How do S. mutans and S. sobrinus cause cavities? (3 steps)

1. makes sticky polymers
begins plaque formation
2. other bacteria attach to layer
3. biofilm anaerobes eventually damage soft tissue and bone

How does S. mutans break down hard tooth structure?

produces an acid that leaches calcium

What prevention measures can be taken to avoid dental caries?

flouride: helps to retain calcium
regular brushing: removes plaque

What makes food intoxication different from infection?

symptoms are violent and incubation is very short

What is food intoxication caused by?

preformed toxin (usually S. aureus)

What are symptoms of food intoxication?

patient presents w/ nausea, frequent vomiting, diarrhea

What type of organism is Enterobius vermicularis?

pinworm (a type of nematode)

What is the most common worm disease of children in temperate zones?

Enterobius vermicularis (usually asymptomatic)

How is Enterobius vermicularis transmitted?

fecal-oral route

What is a UTI?

urinary tract infection, can involve any portion of urinary tract

What is cystitis?

bladder infection

What is urethritis?

infection of the urethra

What is pyelonephritis?

infection of the kidney

What bacterium causes 80% of UTIs?

E. coli

How does E. coli attach to urinary epithelia?

adhesions

Where is E. coli transmitted from into the urinary tract?

the GI tract

How are UTIs prevented?

personal hygiene

How are UTIs transmitted?

opportunistic GI normal biota

What does overuse of antibiotics lead to?

increase in number of resistant bacteria

What is the causative agent of gonorrhea?

Neisseria gonorrhoeae

What is another name for Neisseria gonorrhoeae?

gonococcus

What are the cellular characteristics of Neisseria gonorrhoeae?

gram negative diplococci

What are the virulence factors of Neisseria gonorrhoeae?

fimbriae
protease that inactivates IgA

How is gonorrhea transmitted?

sexual contact; fomites

What is the portal of entry for gonorrhea?

genital/extragenital

What is the treatment for gonorrhea?

Ceftriaxone (antibiotic)

What are the symptoms of gonorrhea in males?

- urethritis
- can occasionally spread to prostate and epididymis
- scar tissue in ducts can lead to infertility

What are the symptoms of gonorrhea in females?

- mucopurulent or bloody vaginal discharge
- urethritis
pelvic inflammatory disease

What is pelvic inflammatory disease?

Infection of the upper reproductive tract in the female, usually but not always an advanced stage of gonorrheal infection, can cause sterility or ectopic pregnancies by scarring fallopian tubes

What is a chancre?

a painless ulcer, particularly one developing on the genitals as a result of venereal disease.

What is a chancre indicative of?

syphilis

What is the cause of prostatitis?

endogenous transfer from normal biota of GI tract

What are the natural defenses of the respiratory tract?

- cilia
- microvilli
- complement action in the lungs
- increased levels of cytokines and antimicrobial peptides
- macrophages in alveoli of lungs and tonsils
- Secretory IgA against specific pathogens is found in mucous secretions
- normal flora defend host by microbial antagonism

What are the possible causative agents of the common cold?

approximately 200 viruses