Microbiology Final Exam

What barriers exist to using vaccination to eradicate disease?

Religious beliefs, Allergies/medical reasons, No access to healthcare/vaccinations, Financial reasons

What are ELISA tests?

Enzyme-linked immunosorbent assays

What are the pros of ELISA tests?

Can identify a wide variety of pathogens, work very quickly, very accurate

What do ELISA tests rely on?

Antibody-antigen interactions, Reporter enzyme attached to a monoclonal detecting antibody (recognizes just one type of antigen)

What are the 3 forms of ELISA tests?

Direct, Indirect, Sandwich

What is an attenuated vaccine?

A vaccine with altered pathogens that do not cause disease but can still be infectious

What are the pros of live attenuated vaccines?

Long-lived memory because it is the actual pathogen

What are the cons of live attenuated vaccines?

Can cause disease in immunocompromised hosts, there is the possibility that the pathogen can mutate back to it’s infectious form

What is a vector vaccine?

A vaccine that requires a carrier pathogen to deliver genetic information from the pathogen

What is an inactivated vaccine?

A vaccine with whole inactivated or partially inactivated pathogens

What are the pros of inactivated vaccines?

Stable at room temperature, safe for immunocompromised people

What are the cons of inactivated vaccines?

Boosters are needed to achieve full immunity and many people choose not to/forget to get the booster

What is a whole-agent vaccine?

A vaccine with the entire dead agent, inactivated virus. It contains the same agent that you would encounter in nature in it’s full form, but will not cause disease

How are whole-agent vaccines deactivated?

By chemicals, heat, radiation

What is a subunit vaccine?

A vaccine with a portion of the pathogen

What is a drawback of subunit vaccines?

It requires an adjuvant (Some sort of pharmaceutical additive that will enhance our bodies natural response to the pathogen. It is attached to the antigen and increase the response of our body).

What are the 3 categories of subunit vaccines?

Purified subunit, toxoid, conjugate

What is a purified subunit vaccine?

The vaccine contains purified natural parts of the actual pathogen or engineered parts of the pathogen

What is a toxoid subunit vaccine?

The vaccine contains an inactivated protein toxin

What is a conjugate subunit vaccine?

The vaccine adds or links a protein antigen to the polysaccharide antigen to make a better immune response

Do vaccines provide immediate protection?

No, our bodies need to mount an immune response first

How does an agglutination test work?

Antibodies clump together with the antigens

Why are agglutination tests useful?

Can visibly look for this clumping (change in color, light reaction). We can see this clumping if a patient has been exposed to an antigen and created antibodies (some tests are looking for the antigen, some look for the antibodies)

What are agglutination tests used for?

Blood typing, infection identification, diagnosis of noninfectious immune disorders

What is herd immunity?

85% or more are vaccinated

How could herd immunity breakdown in a community?

Antigenic shift/drift, horizontal gene transfer

Why did Alexander Fleming suspect he could get an antimicrobial from a species of mold?

The mold prevented the normal growth of the streptomycin

What are Fluroquinolone drugs?

Synthetic antimicrobials that contain a fluorine atom

What do Fluroquinolone drugs target?

DNA replication enzymes

What are the general characteristics of Fluroquinolone drugs?

Administered orally, active against many pathogens, penetrate well into tissues.

What are the standard side effects of Fluroquinolone drugs?

GI upset, headaches, dizziness, insomnia

What are Glycopeptide drugs?

Drugs that were originally naturally occurring products made by strep species

What are the general characteristics of Glycopeptide drugs?

No beta-lactam ring, administered orally (to treat intestinal infections) or by IV (to treat systemic infections)

What are the general characteristics of Rifamycin drugs?

Broad spectrum drug prescribed to treat mycobacterium

What is special about the prescription of Rifamycin drugs?

Prescribed in combination with another drug, but can make other drugs ineffective (oral contraceptives, HIV meds, heart condition/blood pressure/blood thinner meds)

What are the side effects of Rifamycin drugs?

GI upset, heartburn, fatigue, drowsiness, dizziness, headaches

What is the half-life of a drug?

The time it takes for half of the dose to be eliminated/deactivated by the body

How does half-life relate to dosing?

It determines how frequently we administer the drug (ex: if a drug has a short half life, you would need to take it more frequently)

What actions can be taken by healthcare providers to reduce acceleration of drug resistant pathogens?

What is the therapeutic index?

The ratio of the maximum safe dose to the minimum effective dose

What is a narrow therapeutic index?

Drugs have a dosage that is close to the toxic dose. They must be carefully dosed and monitored for toxicity effects

What is a high therapeutic index?

Drugs have a dosage that is well below the possibility of being toxic, but are still effective

How do sulfa drugs work?

Target a bacteria-produced enzyme that targets folic acid (something we don’t produce)

What are sulfa drugs?

Bacteriostatic, broad spectrum drugs that don’t effect human cells

What is the purpose of the Kirby-Bauer test?

To determine the sensitivity or resistance of bacteria to various antimicrobial compounds

What are broad spectrum drugs?

Drugs that work against a wide variety of both gram positive and gram negative bacteria

When are broad spectrum drugs most likely to be prescribed?

What are the pros of bacteriostatic drugs?

They prevent bacteria from growing

What are the cons of bacteriostatic drugs?

They target protein synthesis and metabolic pathways

What are the pros of bactericidal drugs?

They kill bacteria

What are the cons of bactericidal drugs?

They target cell walls, cell membranes, and nucleic acids, and kill our normal microbiota also which can lead to a deadly spike in bacterial toxins

What are bacteriostatic drugs?

Drugs that prevent bacteria from growing

What are bactericidal drugs?

Drugs that completely kill bacteria

What are Beta-lactam drugs?

Drugs that have a beta-lactam ring that target antimicrobial-resistance enzymes called beta-lactamases

Why is it difficult to develop drugs that target viruses and eukaryotic pathogens?

Viruses and eukaryotic pathogens are not actively replicating, making it hard for the drugs to eliminate the pathogens

What is an E-test?

A procedure that involves spreading test bacterium on the surface of agar plates to determine the Minimal Inhibitory Concentration (the lowest concentration that inhibits the microbe’s growth)

What does an E-test tell us?

The minimum inhibitory concentration: the lowest concentration that inhibits the microbe’s growth

What are the pros of drugs that target ribosomes?

They prevent microbe protein synthesis

What is the causative agent of Covid-19?

SARS-CoV-2

What are the signs and symptoms of typical pneumonia?

High fever, sudden onset of severe chills, shortness of breath, productive cough, chest pain

What are the signs and symptoms of atypical pneumonia?

Low fever, little to no chills, shortness of breath, nonproductive cough, runny nose, muscle aches, joint aches, subtle onset

What are the characteristics of S. pneumoniae?

Humans are the only source

What are the characteristics of H. influenzae?

Leading cause of community acquired pneumonia in adults (outside of the hospital setting)

What are the characteristics of M. pneumoniae?

Commonly referred to as “walking” pneumonia, symptom onset is slow

What are the characteristics of C. pneumoniae?

Severity varies - usually starts with a sore throat then cough for up to 6 weeks. 50% of people are infected by 20 years old

What are the most common causes of typical and atypical pneumonia?

S. pneumoniae, H. influenzae, M. pneumoniae, C. pneumoniae

What are the different types of HPIV?

HPIV1, HPIV2, HPIV3, HPIV4

What are the characteristics of HPIV1 and HPIV2?

Most common cause of croup in young children

What are the characteristics of HPIV2?

What are the characteristics of HPIV3?

Can cause bronchiolitis, bronchitis, and pneumonia

What are the characteristics of HPIV4?

Least serious, causes mild cold-like symptoms

What is the most common respiratory illness caused by each type of HPIV?

What are the signs of croup?

Barking cough

What is the role of mucous in the upper respiratory tract?

Sweep microbes towards the mouth to prevent entry to the lungs

Why is otitis media more common in children?

Inefficient drainage occurs, immune system is not fully developed

Why is pertussis (whooping cough) reemerging?

The DTAP vaccine does not provide lifelong immunity and boosters are now needed

What is RSV?

A RNA virus that presents as cold-like symptoms but can be dangerous to young children and elderly

What is sinusitis?

Inflammation and swelling of sinus membranes

What is the most common cause of sinusitis?

Viruses and allergens

What are the signs and symptoms of strep throat?

Inflammation in throat, swollen cervical lymph nodes, low grade fever, puss in throat, no cough

What is the causative agent of strep throat?

Group A streptococcus (GAS) S. pyogenes

What treatment is used for strep throat?

Penicillin based drugs

What are the general characteristics of influenza viruses?

Signs and symptoms are similar to a common cold, but accompanied with a prolonged high fever. Can be deadly to people with preexisting conditions and lead to complications like pneumonia

What is the flu vaccine?

An inactivated vaccine that contains candidate viruses grown in cell culture (chicken eggs)

How do symptoms of the flu compare to the common cold?

Symptoms are the same, but a high fever is also occurring

What is a viral variant?

What is a viral strain?

What are the symptoms of Listeria meningitis?

Minor flulike symptoms, some gastrointestinal issues

What are the characteristics Listeria meningitis?

Transmitted from food (cheese, deli meats, some fruits). Affects elderly, immunocompromised, babies, and pregnant women

What is the most common arbovirus in the United States?

West Nile virus

What are the characteristics of C. botulinum?

Transmitted in soils and honey. Cannot tolerate a high pH and needs low oxygen to grow. Forms endospores and can tolerate high heat. Commonly found in canned vegetables

What factors of C. botulinum contribute to its virulence?

Toxins block neurotransmitters that allow the muscles to contract

What are the characteristics of Neisseria meningitis?

Oxygen loving, had a glcocalyx capsule tightly wrapped around the cell wall to help adhere to hosts and form biofilms

What is meningitis?

Inflammation in the meninges

What are the meninges?

Layers of tissue surrounding the brain that supply nutrients, remove waste, and protect

What is the causative agent of pneumococcal meningitis?

NIH

How is polio transmitted?

Fecal-oral route

What are the signs and symptoms of Polio?

Flulike symptoms. Paralysis in more severe cases

What are the characteristics of rabies?

Kills about 50,000 people worldwide mostly in undeveloped areas

How is rabies transmitted?

Classic zoonosis (animal bite)