Module 5.1 Flashcards

Question

First Nations and Infectious Disease Today: TB

Answer 1

TB Introduction and Spread: Tuberculosis (TB), brought by European settlers, spread rapidly among Indigenous peoples due to overcrowded reserves, residential schools, and Indian hospitals. High Mortality Rates: TB caused some of the highest mortality rates in human populations. Ongoing Issue: Despite antibiotics reducing cases overall, TB continues to persist in Indigenous communities.

Answer 2

have a thick peptidoglycan wall

Answer 3

Bacteria Evolution: Bacteria were among the first lifeforms on Earth and evolved into multicellular eukaryotes. Human Bacteria: Humans host trillions of bacteria, most of which are essential for health. Bacteria Classification: Bacteria are categorized into two groups based on their cell wall structure: Gram-positive and Gram-negative.

Answer 4

have a thin peptidoglycan wall surrounded by an outer membrane

Answer 5

made up of two things important to outer structure Bacterial Cell Wall: The cell wall helps maintain internal pressure and prevents the bacterial cell from bursting. It consists of the plasma membrane and the cell wall. Therapeutic Target: Since eukaryotic cells don’t have cell walls, bacterial cell walls are a good target for therapeutic treatments.

Answer 6

any agent, natural or synthetic that stops growth of or kills microorganisms. Many antimicrobials happen to be antibiotics, but others like bleach, are not.

Answer 7

small molecules used as medications produced by microorganisms that can stop the growth of or kill microorganisms. Hundreds of antibiotics on the market. Those given as medication can be characterized based on how they target and what they target *All antibiotics are antimicrobials, but not all antimicrobials are antibiotics*

Answer 8

inhibit bacterial growth, with the help of the host's immune system. Therefore, bacteriostatic drugs would never be used for life threatening infections.

Answer 9

kill susceptible bacteria, without any help from the host's immune system.

Answer 10

active against a small group of organisms - what they want to move to, to put less selective pressure on bacteria that are formed in the normal flora

Answer 11

kills a wide range of bacteria

Answer 12

start broad spectrum, once results are back, then a more narrow spectrum antibiotic is used

Answer 13

Cell Wall Synthesis Inhibitors: Antibiotics like penicillin prevent proper bacterial cell wall formation by binding to enzymes that crosslink peptidoglycans. Effect: Without crosslinking, the cell wall can't form properly, causing the bacterium to die from osmotic rupture. Specificity: These antibiotics may be specific to Gram-positive or Gram-negative bacteria due to differences in cell wall structure and enzymes.

Answer 14

Targeting Metabolic Pathways: Antibiotics can target metabolic pathways not present in human cells, like folate synthesis. Folate Synthesis: Humans acquire folate through diet, while bacteria synthesize it. Blocking this pathway disrupts bacterial growth. Combination Therapy: Cotrimoxazole is a combination of two antibiotics that block different stages of the folate synthesis pathway.

Answer 15

Protein Synthesis Inhibitors: Antibiotics like doxycycline inhibit mRNA translation into proteins by targeting bacterial ribosomes. Selective Targeting: These antibiotics don’t affect eukaryotic (human) ribosomes, as bacterial ribosomes are structurally different. Lyme Disease Prevention: A single dose of doxycycline can prevent Lyme disease after a tick bite.

Answer 16

Plasma Membrane Disruptors: Antibiotics like daptomycin create leaks in bacterial plasma membranes, disrupting key processes (protein synthesis, chemical gradients), leading to cell death. Side Effects: These drugs can also affect mammalian cells, especially disrupting mitochondrial function, resulting in more severe side effects compared to other antibiotics.

Answer 17

DNA Packaging & Inhibition: Bacterial DNA is tightly supercoiled by DNA gyrase, an enzyme absent in eukaryotic cells. Fluoroquinolones: These antibiotics inhibit DNA gyrase, preventing proper DNA supercoiling, causing DNA degradation and cell death.

Answer 18

Alter Targets: Mutations change the drug target's structure, rendering the drug ineffective. Restrict Target Access: Drugs can't enter the cell, or are pumped out immediately. Develop Drug-Specific Enzymes: Bacteria create enzymes that destroy or modify antibiotics, making them ineffective.

Answer 19

Progeny Transmission: Antibiotic resistance genes are passed on to a bacterium’s progeny. Horizontal Gene Transfer: Resistance genes can spread to other drug-susceptible bacteria, leading to faster and more widespread resistance accumulation.

Answer 20

Infection: Host is infected with pathogenic bacteria, some drug-resistant. Treatment: Antibiotics kill most bacteria, but not the drug-resistant ones. Proliferation: Drug-resistant bacteria multiply, unaffected by the treatment. Gene Transfer: Drug-resistant bacteria can transfer resistance to drug-susceptible bacteria.

Answer 21

transformation: Extracellular DNA taken up by a bacterium and incorporated into its genome Conjugation: Direct cell-to-cell contact through plasmid gene transfer to a recipient cell. Transduction: Transfer of gene through the infection with a bacteriophage (bacterial virus)

Answer 22

Metabolic Cost: Maintaining antibiotic resistance requires extra energy for processes like protein production and structural alterations. Evolutionary Perspective: If the antibiotic is no longer present, non-resistant bacteria can grow faster as they don't waste energy on resistance. Selective Pressure: Antibiotic-resistant strains survive only when the antibiotic is present; without it, they die off.

Answer 23

Semi-conscious due to brain trauma Open fracture on right leg Surveillance cultures taken for MRSA and carbapenem-resistant organisms Central line placed for meds, fluids, nutrition, and blood draws had low blood pressure increased WBC count pos test for MRSA Most common treatment = vancomycin

Answer 24

Common cause of skin and soft tissue infections. Can be treated with antibiotics, but options are limited due to resistance. Antibiotic-Resistant Bacteria in Canada MRSA has become a persistent and serious health concern, causing severe complications and deaths. In response to rising cases, Canada implemented public health programs in 2010. Despite efforts, MRSA rates remain nearly twice as high as in the early 2000s.

Answer 25

Carbapenem-Resistant Organisms Often resistant to multiple antibiotic classes. Some strains are resistant to all available antibiotics, making treatment very difficult.

Answer 26

S. aureus developed resistance to penicillin via beta-lactamase, which destroys the drug. Methicillin was introduced in 1959 to bypass beta-lactamase. S. aureus evolved again—mutated penicillin-binding protein—making methicillin ineffective. By the mid-1980s, MRSA had become widespread, especially in hospitals.

Answer 27

extremely common

Answer 28

Non-prescription use and unregulated sales are widespread in low- and middle-income countries. China: Hospitals rely on antibiotic sales for revenue. Illegal pharmacy sales without prescriptions are common. India: Doctors often receive compensation from pharmaceutical companies, encouraging overprescription.

Answer 29

very rare for now leave few antibiotic choices remaining for treatment.

Answer 30

Decades of extensive antibiotic use (~75 years) created selective pressure, leading to widespread resistance. Beta-lactamases are a key example: ~2,800 types identified—a 10x increase since pre-1990. Carbapenem resistance: First seen in 2008, now global. Carbapenems treat multidrug-resistant infections—resistant strains may have no treatment options left.

Answer 31

Excessive use of antibiotics worldwide is creating an ideal environment for bacteria to develop resistance.

Answer 32

Widespread use to promote growth and prevent disease in densely housed animals. Major driver of global antibiotic overuse, especially in agriculture and aquaculture. In Canada, agriculture accounts for 82% of antibiotic use. The majority of global antibiotic production goes to agriculture, aquaculture, and veterinary use.

Answer 33

In 2018, ~26% of infections were antibiotic-resistant; expected to rise to 40% by 2050 (PHAC) Annual deaths: ~5,400 (2018) → projected 13,700 by 2050 Economic impact: ~$1.4 billion/year Due to longer infection duration, costlier treatments, and more complications for survivors

Answer 34

PHAC Strategy to Combat Antibiotic Resistance Surveillance – Monitor antibiotic use & resistance trends Stewardship – Promote appropriate antibiotic use in all sectors Research & Innovation – Support ongoing antibiotic discovery & development Infection Prevention & Control – Enforce hygiene & sanitation best practices

Answer 35

1) EU Ban on Antibiotics in Food Production (2006) 2) Medical Guidelines – Prescribing limited to clear, evidence-based guidelines 3) Conflicts of Interest – No gifts from pharmaceutical companies, and limited drug ads to patients 4) Prescription Statistics – Tracking prescriptions for various antibiotic classes 5) Hospital Screening – Resistant organisms screened and isolated in hospitals and long-term care settings

Answer 36

1) Unregulated Antibiotic Sales – Antibiotics sold without prescriptions, often without oversight 2) Medical Ethics – Weaker enforcement of ethical guidelines compared to high-income countries 3) Lack of Resources – Limited access to accurate testing, funding, and leadership in healthcare 4) Quality Issues – Poor quality antibiotics may contribute to increased resistance

Answer 37

1900-1919: Salvarsan (early antibiotic) 1920-1939: Sulfonamides 1940-1979: The "Golden Age" – over 20 new classes of antibiotics, MRSA detected 1980-1999: Only 3 new classes, VRE (Vancomycin-resistant Enterococci) detected 2000-Present: 5 new classes, VRSA (Vancomycin-resistant Staphylococcus aureus) detected, UN declares antibiotic resistance a global threat

Answer 38

Limited new antibiotics discovered since the 1970s. The pharmaceutical industry is not motivated to invest in new antibiotics due to limited profitability. Need: 20 new antibiotic classes in the next 20-50 years to combat resistance.