VBS Exam 3 - flash cards

Active Immunity

Triggered by exposure to an antigen, leading to long-lasting protection with memory cells.

Passive Immunity

Immediate but temporary protection without memory cell formation, achieved through antibody transfer.

Variolation

Collecting smallpox material for protection.

Smallpox Vaccination

Using cowpox to induce immunity against smallpox.

Attenuated Vaccine

Weakened live virus that can replicate in the body.

Toxoid Vaccine

Contains inactivated toxins used against diseases caused by bacterial toxins.

IPV

Inactivated polio vaccine used in polio-controlled countries.

OPV

Oral polio vaccine crucial in areas with wild poliovirus circulation.

Immunocompromised

Individuals unable to receive attenuated vaccines due to risks.

Boosters

Necessary for subunit vaccines to enhance immune response.

Adjuvants

Substances like aluminum hydroxide to boost vaccine effectiveness.

Conjugate HiB Vaccine

Combines polysaccharides with proteins for better immune response.

RNA Vaccines

Introduce mRNA to trigger immune response, offering rapid development.

Vaccine Development for COVID-19

Includes DNA, RNA, subunit, inactivated, chimeric, and attenuated vaccines.

Clinical Vaccine Trials

Progress through phases from preclinical testing to human trials (Phase 1-4).

Antibiotic Administration in Livestock

Through injections, pills, or mixing in feed or water.

Antibiotic Resistance Spread

Through improper disposal, leading to environmental contamination.

Veterinary Feed Directive

Changed antibiotic use by requiring prescriptions for medically important antibiotics.

Co-selection

Involves linked resistance genes for antibiotics and metals on the same plasmid.

Define the terms: APEC, ExPEC, FUTI, COPs

Terms related to bacterial infections and colonization.

• APEC: Avion pathogenic E.Coli. 

  • Causes Avian Colibacillosis. 

  • Can enter through air

  • Ascending (reproductive)

  • Skin breaks

  • In ovo/during hatch

  • UTI had same strain as chicken

• ExPEC: extra intestinal pathogenic E.coli.

  • Causes disease outside of the gut

• FUTI: Foodborne Urinary Tract Infection

• COPs: Colonizing Opportunistic Pathogens. 

  • Do not cause disease inside the gut, but once outside they will.

  • Eat undercooked chicken or touch contaminated surfaces

  • Touch mouth with own fingers

  • Get colonized with drug resistant ecoli from chicken

  • Time goes on

  • Get a UTI

Foodborne E.coli

Ingestion leading to UTI through gut contamination.

Salmonella Reading Strains

Recent strains more resistant and cause severe outbreaks.

Lyme Disease Contagiousness

Non-contagious, transmitted only through tick bites.

Symptoms vs signs

Symptoms are felt by the patient, signs are measurable observations.

Virulence Factors

Enhance microorganism's ability to cause disease.

Mycobacterium tuberculosis Evasion

Resists immune cells by having a thick, waxy cell wall.

Prodromal

The prodromal period is before the symptomatic period in some illnesses and is early, vague symptoms like headache or malaise

Latent Infection

Microbe remains dormant in the body without causing symptoms.

Outbreak Definition

Occurrence of a disease above normal expectations.

Most Common Source of Foodborne Illness

Fresh produce.

Most Common Cause of Foodborne Illness

Norovirus, followed by bacterial pathogens.

FDA vs USDS

FDA inspects most food products, while USDS-FSIS inspects meat, poultry, and egg products.

Outbreak Strain

Epidemiologically and genetically related isolates indicating a common infection source.

GenomeTrakr

Sequences pathogens to trace outbreak origins.

EID (emerging infectious disease)

Disease new within a population or rapidly increasing in incidence or range.

Types of EIDs

Old diseases with new forms, new geographic range, increased virulence, and new diseases from spillover events.

Most Common Cause of EIDs

RNA viruses due to high mutation rates.

Zoonosis

Diseases acquired directly or indirectly from animals.

what is EID caused by?

Emerging Infectious Diseases caused by animals but not always sustained through animal interaction.

Reverse Zoonosis

Diseases transmitted from humans to animals.

SARS-CoV-2

An EID of probable animal origin with close relatives found in bats.

Natural Hosts

First hosts within an infectious disease, asymptomatic.

Transmission Hosts

Acquire infection from natural hosts and show symptoms.

Spillover Events

Contact with animals leading to infections in humans.

Streptococcus mutans

Bacteria causing tooth decay by demineralizing enamel in the presence of sucrose.

Dental Caries Prevention

Good oral hygiene, fluoridated water, and reduced sucrose intake.

Periodontitis Development

Prolonged gingivitis leading to gum recession and plaque accumulation.

what is ANUG?

Acute Necrotizing Ulcerative Gingivitis caused by Treponema and anaerobic bacteria.

Cold Sores

Caused by Herpes Simplex Virus 1, leading to recurrent outbreaks.

Gut Microbiome

Acts as a barrier, modulates the immune system, and aids in gut maturation.

Gastroenteritis

Inflammation of the stomach and intestines, causing loose stools.

Vibrio cholerae

Causes profuse watery diarrhea through AB enterotoxin production.

what does strain E cause?

Strains causing bloody diarrhea due to Shiga toxin production.

what is Hepatitis and the common ones?

Inflammation of the liver, caused by viruses A, B, and C with varying transmission routes and outcomes.

What is endemic?

•  Constantly present in a population

  • Ex. the common cold is endemic in MN

    • Malaria is not endemic in MN

what is incidence in epidemiology?

• Number of new cases in a given time (yr) in a given population (usually expressed per 100,000 people)

  • Ex, From the MDH: there were 375 cases/ 100,000 people in MN in 2014

 How does the value of R0 influence vaccination strategies?

• R0 is used to calculate the percentage of people who must be vaccinated to achieve herd immunity

  • Measles: R0 herd immunity needs to be 93-95%

  • Polio: R0: 5-7 herd immunity needs to be 80-85% to prevent/ protect self from spread of the disease

 How did the Veterinary Feed Directive (2017) change the way antibiotics are given to livestock in the US?

• eliminated growth promotion label for medically important antibiotics

• prescription required by the veterinarian for all medically important antibiotic use

• Disease prevention still exists

• This was a voluntary action by pharmaceutical companies and animal agriculture bc they came together and advocated for it not to be over-the-counter

what are the 2 bacteria used in the yogurt lab?

•  fermentation of lactose in the milk by lactobacillus and streptococcus produces lactic acid which gives yogurt its tart flavor and thick texture

Compare and contrast the terms gastroenteritis, diarrhea and dysentery.

• Gastroenteritis: inflammation of the stomach and intestines

• Diarrhea: loose, watery stools, may be more frequent. Watery diarrhea associated with small intestine infection.

• Dysentery: inflammation that includes bloody diarrhea with pus. Usually associated with infection of the large intestine. Result of intense inflammatory response when cells die, producing blood and pus (dead neutrophils)

Describe 3 basic mechanisms bacteria use to infect the lower GI tract and cause gastroenteritis. Give an example of a bacterium that uses each one.

• 1. Attach to epithelial cells: using surface molecules to bind to receptors on the epithelial cells.

  •  The type of surface molecule present on the outside of bacterial cell determines which type of host receptor is bound, which dt which part of the digestive system will be infected.

• 2. Produce toxins

  • -a. Enterotoxins: watery diarrhea (produce in small intestine)

  • -b. Cytotoxins- kill host cells which produces an inflammatory response that can lead to dysentery (large intestine)

  • -c. Neurotoxins- microbial intoxications, 

    • Ex: C. botulinum.

• 3. Invade cells: can become systemic via entering the bloodstream.

 How does Vibrio cholera cause disease? How can this disease be prevented?

• Cholera causes profuse watery diarrhea that can lead lead to dehydration and death. Sometimes within hours

  •  It produces an AB enterotoxin. AB toxins have two subunits: one attaches to the outside of host cell, the other enters the cell. 

  • The cholera toxin causes dysregulation of membrane transport, so irregular amount of Na, Ca, and K leave the cell. This is normally regulated by cyclin AMP (cAMP) (activates ion transport channels) so that ions leave the cell

  • cAMP is regulated by a G protein, opening the ion transport channel. Now that ion concentration is higher outside of the cell, water eventually leaves the cell by osmosis, which produces profuse watery diarrhea. It causes rice water diarrhea.

• Prevention: improved sanitation, cook food, wash hands, vaccinate

• Treatment: oral rehydration therapy or IV (reduces mortality rate)

How can dental carries be prevented?

• Brushing/flossing reduces incidence by half

• Drinking water with fluoride has reduced dental carries in the US by 60%

• Decreasing sucrose ingestion and frequency

How does periodontitis develop? How are gingivitis and periodontitis related?

• Prolonged gingivitis leads to periodontitis.

• The gums recede and pull away from the tooth, allowing for plaque and tartar to form between the tooth and gum tissue.

• What are prions?

• Chronic degenerative brain infections

  • Humans: Creutzfeldt-Jakob disease (CJD, vCJD) and kuru (cannibalism)

  • Sheep and Goats: scrapie

  • Cows: “mad cow” disease (BSE); probable transmission to humans through meat (beef)

Chronic wasting disease in elk and deer

• How do prion particles form? and are there treatment?

• Cells produce normal form of the protein, PrPC.

• Prion form (PrPSc) resistant to heat, formaldehyde, UV and ionizing radiation, proteases.

• PrPSc converts PrPC . As prions aggregate, nerve cells are damaged and die.

• No treatment for prions disease