BIOL 251 UNIT 4 EXAM STUDY GUIDE

Which helminths are round worms and which are flat?

Round: Nematodes

Flat: Cestodes/tapeworms, Trematodes/Flukes

How does a hook worm enter the body?

Through skin and travels thru capillaries to lungs

How are the eggs of pin worms spread?

Fecal-oral route. They are spread, swallowed and hatched in small intestine.

Where do tape worms usually live? Where can they migrate to in some cases?

Usually the LARGE and small intestine. Migrate to brain, liver or other organs

What organism flukes often need to infect before they can cause disease in humans?

Has to infect another host, often a snail.

How is the guinea worm extracted from the body?

slowly and carefully to prevent deathly allergic rxns. Anthelminthic meds/treatment, or twig/grass

Which worm leads to extreme swelling in the body?

Wolbachia sp. bacteria living on the Wuchereria bancrofti/elephantitis worm

What type of disease N. fowleri causes?

primary amoebic meningitis (PAM)

General symptoms of G. intestinalis?

• Yellow foamy diarrhea

• Intestinal cramping

• Low fever

What animal is T. gondii associated with? When is infection problematic?

Cats/felines.

Can cause infection in a fetus baby. If the person is HIV/AIDS positive

Where is T. vaginalis found? Significant factors and symptoms?

Human urogenital tract. Yellow discharge, pain in urogenital area, inflammation

How is Plasmodium sp. transmitted and which specific cells in the body it needs to live inside?

Bite from mosquitos → blood→ liver→ back into blood. Red blood cells

Which organism causes valley fever? Where is it found? Type of infection usually causes?

Coccidioidomycosis. In soils of warm/hot climates. Pulmonary and systemic infection.

What type of organism causes ring worm?

Tinea spp., a fungal infection

Why C. auris is such a serious threat?

Has high lvls of resistance to existing antifungals

What type of disease P. jiroveci causes and who it generally causes that in?

Causes pneumonia in immunocompromised people (HIV/AIDS patients)

How do bacteria and viruses cause disease?

By directly dmging cells/tissues, toxins, enzymes. affecting intracellular infection, the host immune response and inflammation

How do prions cause disease?

Insert self into cell membranes and cause normal proteins to fold incorrectly

How do fungal disease cause disease?

Through toxin production, tissue destruction, allergic rxns

How do parasites (protozoa and helminths) cause disease?

Thru cell/tissue dmg, nutrient deficiencies and avoiding/altering host defenses

What are the three main categories of diagnosing disease?

1. Phenotypic

2. Genotypic

3. Immunologic

Different techniques in phenotypic, genotypic and immunologic diagnosing?

Pheno: Physical characteristics view thru culturing, staining, differential media, direct antigen testing, biochemical testing

Genotypic: DNA/RNA Sequencing thru PCR (Polymerase chain rxn), FISH

Immunologic: Antigen-antibody interactions thru agglutination or precipitation

How many significant species of staphylococcus are there?

5 : S. aureus, s. epidermis, s. capitis, s. hominis, s. saprophyticus

how many deaths Staphylococcus species lead to per year in the US?

100,000

ways in which S. aureus and/or its toxins may be spread?

Endogenous infections, skin to skin contact, thru food

what a toxigenic infection is?

Disease where toxins alone are causing the problem

which species of Streptococcus is usually only problematic during the birthing process

s. agalactiae

what organism has the C and M surface antigens and what they generally do to help the organism cause disease

s. pyogenes. they help w/ attachment and immune evasion/virulence

how to differentiate S. aureus from S. pyogenes not just based on shape and arrangement

S. Aureus: Has irregular clusters, produces coagulase, staphylokinase, penicillinase, toxic shock toxin, exfoliative toxin, alpha toxin and is often spread thru skin contact and food

S. Pyogenes: Occurs in chains, produces streptokinase, protease, streptolysins, pyrogenic toxin and causes strep throat and scarlet fever, spread thru droplets/contact/fomites

which regions of the body N. gonorrhoea may infect

Genital and extragenital regions

how many subtypes of capsules N. meningitidis has

12

how C. diphtheriae causes disease

Produces diphtherotoxin acquired by transduction, toxin is phage encoded, causes pseudo membrane formation, and then the toxin dmgs heart and nerves and stops protein synthesis

what problems C. difficile might cause and how the organism is spread

Overgrows when normal intestinal flora are disturbed. Causes potentially lethal diarrhea

what metabolic pathway C. perfringens might use and what the results of that pathway are in the human body

Might use fermentation, causes gas gangrene and gas buildup separates tissue layers

which species of Clostridium produces tetanospasmin and what the effects of that toxin are

C. tetani and effects by causing involuntary muscle contractions

how M. tuberculosis is passed and how long it can survive outside the body and remain infectious

Spread by droplets. Survive outside of body for up to 8 months

what animal besides humans M. leprae can be found on

Found in armadillos

what types of infections P. aeruginosa can cause

• lung

• systemic

• skin

• urinary tract

• ear and eye infections

whether P. aeruginosa is difficult to control and why

It is, bc it is resistant to disinfectants, soaps, dyes, antibiotics, etc. Structures like toxins, enzymes, slime layer, metabolic diversity and LPS

characteristics of the toxin produced by B. pertussis

Binds to cilia, creates excess mucus, kills ciliated cells and causes whooping cough

general progression of disease for T. pallidum and what disease that organism causes

1. Primary syphilis

2. secondary syphilis

3. tertiary syphilis

4. congenital syphilis

Causes syphilis and transmitted sexually or from mom to fetus

name of the organism associated with stomach ulcers?

H. pylori

general characteristics of Herpes Simplex 1 and 2?

Both enveloped DNA

1: Causes oral infections

2: Causes genital infections

What are the two stages of Varicella Zoster infection commonly called?

Chickenpox and shingles

What conditions is the Epstein-Barr Virus (EBV) associated with?

Mononucleosis, certain types of cancer, and chronic fatigue syndrome.

General characteristics of Rubella?

Known as "German measles," an enveloped RNA virus spread via respiratory secretions. It can be postnatal or congenital (fetal).

Is there a higher chance of complications from natural measles or the measles vaccine?

Natural measles associated with complications like encephalopathy

Characteristics of Hepatitis A, B, and C?

• Hep A: Short-term; fecal/oral transmission.

• Hep B: Short or long-term; fluid transmission.

• Hep C: Most likely to cause long-term infection, cancer, and permanent liver damage; blood/fluid transmission.

What can Papilloma viruses cause?

cause warts (body and genital). High-risk strains (16 and 18) cause 70% of reproductive cancers, plus anal and oral cancers.

Typical symptoms of Influenza?

Respiratory illness with coughing, body aches, fever, and congestion. (It is NOT the "stomach flu").

Which antigens help Influenza enter and exit host cells?

Hemagglutinin (H) helps the virus enter/bind; Neuraminidase (N) helps the virus get out.

Why is there a new flu vaccine every year?

Because the combinations of H and N subtypes vary from year to year.

What are the stages of Rabies infection?

Incubation, Prodromal, Furious, and Dumb.

How does HIV go from RNA to DNA? how is it a permanent infection?

It is a retrovirus that uses the enzyme reverse transcriptase.

How does HIV cause illness?

It infects white blood cells, leaving the immune system open to other opportunistic infections.

True or False: Being HIV positive always means you have AIDS.

False. You only have AIDS if you meet specific criteria (CD4 count < 200, CD4 < 14% of lymphocytes, or an AIDS-defining illness). With modern medication, many HIV+ people never develop AIDS.

What criteria lead to an AIDS diagnosis?

A CD4 count < 200 cells, CD4 cells < 14% of total lymphocytes, or the presence of one or more AIDS-defining illnesses.

Is there a cure for HIV?

No definitive cure is listed; management relies on prevention (PrEP) and anti-retroviral drugs (Inhibitors).

Characteristics of Polio (Mild vs. Severe)?

• Mild (Non-paralytic): Muscle pain, spasms, and meningeal inflammation.

• Severe (Paralytic): Muscle paralysis and cardiorespiratory failure.

General characteristics of Coronaviruses?

Enveloped RNA viruses; they cause everything from "cold-like" illnesses to death. They enter through eyes/nose/mouth and multiply in various cell types.

General characteristics of Prion diseases?

Caused by infectious proteins (not viruses). They cause host proteins to change shape and tangle, leading to cell death and neurodegeneration (e.g., CJD, Mad Cow). cause normal proteins to refold/change shape.

What is the "Stomach Flu"?

Nothing. The professor stated this term means nothing; true Influenza is a respiratory disease. Nausea/vomiting is usually Norovirus or food poisoning.

How long can Measles (or the Flu) linger in the air in a "droplet cloud"?

Up to 4 hours.

What is the "Passive Immunity" treatment for Rabies exposure?

A two-pronged approach: 1) Antibody injection (pre-made antibodies for immediate protection) and 2) Rabies vaccine (to help the body make its own long-term antibodies).

What is the prognosis for someone who enters the Furious Stage of Rabies?

99.9% fatality.

What are the 4 specific Prion diseases mentioned?

1. CJD: Sporadic (85%) or hereditary (15%).

2. Kuru: Transmitted via cannibalism (consuming brain tissue).

3. Fatal Familial Insomnia: Genetic; stops the person from ever falling asleep again.

4. Mad Cow (BSE): Transmitted from cows to humans via meat.

What does H (Hemagglutinin) and N (Neuraminidase) do for the Flu?

H is for entry (binding/clumping red blood cells); N is an enzyme used for entry and exit from the host cell.