Infection Flashcards
What are the components of the national immunisation program for children in Australia and New Zealand?
Diphtheria/tetanus/pertussis/polio/hepatitis B/Haemophilus influenzae type b (1 injection), Pneumococcal (1 injection), and Rotavirus (1 oral vaccine).
How does the mRNA COVID-19 vaccine work?
It uses mRNA to encode viral spike proteins, stimulating immune response through antibody production by B cells.
Define the term “antimicrobial” and explain how antimicrobials work.
Agents that kill or inhibit the growth of microorganisms, including bacteria, viruses, fungi, and parasites. They work by targeting specific features of microorganisms, such as bacterial cell walls, protein synthesis machinery, or DNA replication processes.
What is a vaccine?
A biological preparation that provides active acquired immunity to a particular infectious disease. It contains an agent that resembles a disease-causing microorganism, often made from weakened or killed forms of the microbe, its toxins, or one of its surface proteins.
What is the primary cause of the common cold?
The common cold is primarily caused by a variety of viruses, including rhinovirus, coronavirus, parainfluenza virus, respiratory syncytial virus (RSV), and adenovirus.
How is Helicobacter pylori infection diagnosed?
Helicobacter pylori infection can be diagnosed using endoscopic biopsy or a non-invasive test that measures urease in an individual’s breath.
What are healthcare-acquired infections (HAIs), and what are their main sources?
HAIs are infections that patients acquire during the course of receiving healthcare treatment for other conditions. They can be caused by bacteria, fungi, viruses, or other pathogens present in the healthcare environment.
What are some of the standard precautions for infection control in healthcare settings?
Standard precautions include appropriate hand hygiene, use of gloves, use of aprons or gowns, safe handling of sharps, and regular cleaning of surfaces and equipment.
Describe the characteristics of methicillin-resistant Staphylococcus aureus (MRSA).
A type of Staphylococcus aureus bacteria that is resistant to methicillin and other common antibiotics. Beta-lactamase producing gram-positive cocci.
What is antimicrobial resistance, and how does it occur?
Antimicrobial resistance occurs when microorganisms develop the ability to defeat the drugs designed to kill them. This can happen through genetic mutations that allow the microorganisms to inactivate the drug, alter their membrane to prevent drug uptake, or expel the drug from their cells.
Why is overuse of antibiotics problematic?
Overuse of antibiotics can lead to the destruction of normal flora, promoting the overgrowth of antibiotic-resistant strains or pathogens. It can also contribute to the rapid emergence of multiple-antibiotic-resistant bacteria.
What is the role of B cells in the immune response generated by mRNA vaccines?
B cells are stimulated by the viral antigen displayed on macrophages, which leads them to produce antibodies against the viral protein, thereby generating an immune response.
Explain how a urinary tract infection (UTI) occurs. What is the most common cause?
A UTI occurs when bacteria enter and multiply in the urinary tract, causing infection. The most common causative agent is Escherichia coli, which can enter the urethra due to its proximity to the anus.
What are the main clinical symptoms of a urinary tract infection?
Symptoms of a UTI include dysuria (painful urination), urinary urgency and frequency, fever, haematuria (blood in urine), and smelly, cloudy urine.
How does diabetes complicate recovery from infections?
Diabetes can impair immune function, reduce blood flow, and increase the risk of infections, complicating recovery due to slower healing and increased susceptibility to further infections.
Describe the steps involved in a gram stain.
The steps in a gram stain include: application of a primary stain (crystal violet), addition of a mordant (iodine), decolorization with alcohol or acetone, and counterstaining with safranin. Gram-positive bacteria retain the crystal violet stain, appearing purple, while gram-negative bacteria do not, appearing red or pink.
What are the main differences between bacteria and viruses?
Bacteria are single-celled organisms with a cell wall and can reproduce independently. Viruses are simpler structures, consisting of genetic material enclosed in a protein coat, and require a host cell to replicate.
What are the three shapes of bacteria?
Bacteria can be shaped as cocci (spheres), bacilli (rods), and spirochetes (spirals).
What are endotoxins and why are they harmful?
Endotoxins are components of the outer membrane of gram-negative bacteria that are released when the bacteria die and disintegrate. They can cause severe inflammatory responses and symptoms such as fever, shock, and multiple organ failure.
How do vaccines induce long-lasting protective immune responses?
Vaccines introduce antigens that stimulate the immune system to produce memory cells and antibodies specific to the pathogen, providing long-term immunity.
Explain the role of personal protective equipment (PPE) in preventing healthcare-acquired infections.
PPE, such as gloves, gowns, and masks, provides a barrier between healthcare workers and infectious agents, reducing the risk of transmission and infection.
What factors have contributed to the decline in infectious diseases in Australia and New Zealand?
Improved infection control measures, vaccination programs, better hygiene, and advanced medical treatments have contributed to the decline in infectious diseases.
