Infection & Immunity Winter 2024 Student Notes PDF

INFECTION & IMMUNITY NURS 2500 DEVELOPED: FALL 2022 BY DR. ASHA PEREIRA RN, EDITED 2023 BY CHERYL PRYCE STUDENT LEARNING OBJECTIVES 1. Describe the general concept of immunity (Giddens concept) 2. Describe the general concept of infection (Giddens concept) 3. Explain the common pathophysiological me...

INFECTION & IMMUNITY NURS 2500 DEVELOPED: FALL 2022 BY DR. ASHA PEREIRA RN, EDITED 2023 BY CHERYL PRYCE STUDENT LEARNING OBJECTIVES 1. Describe the general concept of immunity (Giddens concept) 2. Describe the general concept of infection (Giddens concept) 3. Explain the common pathophysiological mechanisms and impact of an altered immune response and infection 4. Compare and contrast the 4 types of hypersensitivity reactions 5. Describe the principles, practices and processes underlying health assessment of an altered immune response and infection 6. Apply the pharmacokinetics, pharmacodynamics, and pharmacotherapeutics of common therapy targeted to an altered immune response and common therapy targeted to infection using exemplars 7. Apply Nursing Process/Clinical Judgment/Systems thinking (as described in Class 1) to the patient experiencing an altered immune response IMMUNITY Photo credit: https://www.news-medical.net/health/How-to-Optimize- Your-Immune-System.aspx IMMUNITY Physiologic process that provides an individual with protection or defense from disease Accomplished through actions of the immune system Protects body from attacks from foreign antigens Typically proteins Microorganisms: Bacteria, viruses, parasites, fungi Pollens Food Venom (spider, bee, snake) Vaccines Transfusions Transplanted tissue/organs IMMUNITY FIGURE 22.3 IMMUNITY AND INTERRELATED CONCEPT Innate Immunity (also referred to as natural or native): present at birth Acquired immunity: protection gained after birth through either active or passive immunity Natural active acquired immunity: After introduction of a foreign antigen results in formation of antibodies or sensitized T lymphocytes Artificial active acquired immunity: occurs with immunization Artificial passive acquired immunity: occurs when receiving a specific transfusion. For example: immunoglobulin (Ig) Natural passive acquired immunity: antibodies from a mother to fetus through the placenta or from the colostrum or breastmilk. (It is immediate but short lived) (Iggy, pg.40) IMMUNITY PROTECTION NORMAL PHYSIOLOGICAL PROCESS Protects the body from microorganisms and other antigens Removes dead or damaged tissue and cells Recognizes and removes cell mutations that have demonstrated abnormal cell growth and development Suppressed Infection Immune Response Optimal Immune Response Exaggerated Immune Response Allergy / Cytotoxic/ Autoimmun e Lymphoid organs spread throughout the body ORGANS OF THE IMMUNE SYSTEM Spleen, thymus gland, bone marrow, adenoids, tonsils, appendix Lymphocytes are formed, grow, mature and are released Makes up the lymphatic system that along with blood connects the organs ANTIBODY MEDIATED PROCESS CELLS OF THE IMMUNE RESPONSE Derived from stem cells in the bone marrow Myeloid progenitors-Accessory Cells Neutrophils, Monocytes (become macrophages in tissue), Eosinophils Basophils Mast cells Lymphoid progenitor cells B lymphocytes-in liver in mid-fetal life and bone marrow later and after birth Mature T lymphocytes-Thymus gland Natural killer cells Recognize and ingest foreign antibodies as they enter the body Macrophages and neutrophils are the first line of defense PHAGOCYTES AND THE COMPLEMENT SYSTEM Promote proliferation and differentiation of helper T cells and Cytolytic T Lymphocytes (CTLs) Antibody-antigen complexes have rougher surfaces and are susceptible to phagocytosis The complement system-circulates in the blood waiting for the antigenantibody complex. Responsible for dilation and leaking from vascular system-redness and swelling that are part of the inflammatory response Dendritic cells Promote proliferation of CTLs and Helper T cells by serving as antigen presenting cells Helper T cells are like the managers of the immune system. When they find signs of an invader in the body, they spring into action. They help by sending signals that tell other immune cells, like B cells and killer T cells, to start working. Helper T cells help B cells make antibodies to stick onto germs and mark them for destruction. They also help killer T cells get ready to attack infected cells. So, helper T cells don't fight the invaders directly; instead, they help organize and boost the immune response, making sure the body's defense is strong and effective. OVERVIEW OF IMMUNE RESPONSE NORMAL SPECIFIC IMMUNE RESPONSE COPYRIGHT © 2014 ELSEVIER CANADA, A DIVISION OF REED ELSEVIER CANADA, LTD. HYPERSENSITIVITY TYPE I HYPERSENSITIVITY TYPE I ALTERED IMMUNE RESPONSE Anaphylactic Reaction: Minimum 2 systems involved Stridor is an abnormal, highpitched respiratory sound produced by irregular airflow in a narrowed airway. https://www.allergy.org.au/patients/ab out-allergy Copyright © 2019 Elsevier Canada, a division of Reed Elsevier Canada, Ltd. 23 CRP (C-reactive protein) and ESR (erythrocyte sedimentation rate) tests are like detective tools that doctors use to check for inflammation in your body. Inflammation can happen for many reasons, like infection or certain diseases. ASSESSMENT History Clinical findings Suppressed Immune Function Exaggerated Immune Function CRP Test: This test looks for a special protein in your blood that shows up when there's inflammation. If the CRP levels are high, it means there might be some inflammation or infection going on. ESR Test: This test checks how fast your red blood cells fall to the bottom of a test tube. When there's inflammation, these cells fall faster. So, a high ESR might also point to inflammation. Diagnostic Tests Primary Tests Screening Tests RBC, WBC C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) Allergy Testing Skin Test Allergen-specific Immunoglobulin (IgE) blood test Disease specific Testing The number of red blood cells (RBCs) is not directly influenced by the state of the immune system because RBCs are primarily involved in carrying oxygen to tissues and removing carbon dioxide from the body. However, certain conditions that affect immunity can indirectly influence RBC counts: Infections or autoimmune diseases: Some conditions that affect immunity can lead to a decrease in RBC count, causing anemia. For instance, chronic inflammatory diseases can disrupt the production of RBCs or increase their destruction. Bone marrow impact: Diseases that affect the bone marrow, where RBCs are produced, can lead to altered RBC production. If the immune system is compromised due to a bone marrow disorder, RBC counts might be affected as well. Treatment effects: Some treatments for immune-related conditions, like chemotherapy or certain medications, can impact bone marrow function and lead to changes in RBC production, possibly resulting in low RBC counts. So, while the RBC count isn't a direct marker of immune function, changes in RBC levels can occur in the context of diseases or conditions that affect immunity, typically showing low RBC counts rather than high in the context of immune system disturbances. MEET MR HAYES (HE/HIM) His nurse completes an assessment and finds extensive urticaria on his back and swelling of his lips (angioedema). His nurses asks him if he has any allergies in which he states no. She then proceeds to ask if he has ever had morphine before in which he states "Once, about a month ago with one of my gallbladder attacks", https://www.aaaai.org/tools-for-the-public/conditions-library/allergies/hives-%28urticaria%29-and-angioedema-overview Clinical Manifestations of Type 1 Hypersensitivity Reaction ANAPHYLAXIS Condition in which type 1 hypersensitivity reaction involves of all blood vessels and bronchiolar smooth muscle causing widespread blood vessel dilation, decreased cardiac output, and bronchoconstriction within seconds to minutes after allergen exposure Life threatening https://www.allergy.org.au/patients/ab out-allergy Copyright © 2019 Elsevier Canada, a division of Reed Elsevier Canada, Ltd. 29 MEET MR HAYES (HE/HIM) Suddenly, Mr Hayes becomes tachypneic and has increased work of breathing. The nurse calls a code blue. As the team rushes in, the nurse completes another set of vital signs and finds him to be hypotensive, tachycardic, tachypneic and hypoxic and no longer responding to her questions. https://www.aaaai.org/tools-for-the-public/conditions-library/allergies/hives-%28urticaria%29-and-angioedema-overview GENERAL PRINCIPLES OF VACCINE ADMINISTRATION Vaccines are preventative measures that improve immune response to infectious agents Dosage, number of doses and timing of doses are important considerations Scheduling developed by CDC Vaccines are generally safe with few contraindications and adverse effects Common adverse effects of vaccines Redness, swelling at site of injection Soreness, tenderness at site of injection Fever Fatigue Poor appetite headache Precautions and contraindications Immunocompromised patients – patients are unable to produce an active immune response History or allergy/anaphylactic response to vaccine components (preservatives etc.) Antigen – a marker, usually a protein, found on the surface of infectious agents Introduction of foreign antigens to trigger immune response, allowing immune system to react more effectively the next time it is exposed to antigen Effective vaccination, to confer long-term immunity to a disease, sometimes requires “boosters” or follow-up doses Bacterial vaccines VACCINATION Inactivated bacterial exotoxins e.g. Tetanus Killed bacteria e.g. Pneumococcal Live attenuated bacteria - ↑response, but ↑risk Viral vaccines Live attenuated virus - ↑response, but ↑risk Killed virus Recombinant – cultured vaccine; needs booster Live viral vaccines produce ↑ protection and longer immunity and production of IgAs, IgGs, and cellular immunity Killed virus only produce IgGs. COPYRIGHT © 2014 ELSEVIER CANADA, A DIVISION OF REED ELSEVIER CANADA, LTD. 34 Local cellular injury refers to damage that occurs to cells in a specific area of the body, Sepsis is a severe reaction to an infection where the body's immune response becomes overactive, leading to widespread inflammation that can damage tissues and organs. It can stem from infections in various parts of the body, such as the lungs or skin. When not treated quickly, sepsis can cause organ failure and be life-threatening. Immediate medical attention is crucial to manage sepsis and prevent its progression. Giddens, 2021 p.231 COPYRIGHT © 2014 ELSEVIER CANADA, A DIVISION OF REED ELSEVIER CANADA, LTD. 38 TRANSMISSION OF INFECTIOUS AGENTS (POTTER & PERRY, P.683) METHODS OF TRANSMISSION Contact transmission Droplet transmission Airborne Transmission METHODS OF INFECTION CONTROL AND PREVENTION Hand Hygiene Standard Precautions Transmission-Based Precautions Isolation Precautions Contact MRSA C.difficile Droplet Covid 19 Airborne TB https://www.google.com/url? sa=i&url=https%3A%2F%2Fwww.army.mil%2Farticle%2F234793%2Flrmc_implements_covid_19_ppe_protocols_to_ensure_staff_patient_safety&psig=AOvVaw1yd gMmhGkDkx_5vxhR4sNJ&ust=1693509217932000&source=images&cd=vfe&opi=89978449&ved=0CBAQjRxqFwoTCMizy82LhYEDFQAAAAAdAAAAABAE STAGES OF INFECTIOUS DISEASES POTTER & PERRY P.680 https://www.coursehero.com/sg/microbiology/stages-of-disease/ Incubation: Entrance of pathogen, appearance of symptoms Prodromal: Onset of nonspecific symptoms to more specific symptoms (spread risk) Illness: Patient manifests symptoms specific to the type of infection (peak) Convalescence: Acute symptoms disappear and body returns to homeostasis; recovery occurs Normal flora refers to the collection of microorganisms, including bacteria, fungi, and viruses, that live on and inside your body without causing harm. They're like friendly neighbors or roommates in your body's community. These microorganisms are found on your skin, in your gut, and in other areas, providing benefits like helping with digestion, protecting against harmful pathogens, and supporting your immune system. In a balanced state, normal flora contributes to your overall health and well-being. Neutropenia is a condition marked by low levels of neutrophils, which makes the body more prone to infections and can result in infections being more severe and recovery taking longer. People with neutropenia need to be closely monitored for signs of infection and may require preventive measures or treatments to boost their immune defenses. CLINICAL MANIFESTATIONS OF INFECTION Local Signs: General Systemic Signs: 1) Signs of inflammation: Redness, pain, heat, swelling. 1) 2) Exudate may be present: Purulent (pus) in a bacterial infection, serous if viral. 3) 4) Lymphadenopathy (swollen and tender lymph nodes). System-specific signs. Examples include: vomiting or diarrhea with GI infections; sneezing, coughing and difficulty breathing with respiratory tract infections. Fever (or subnormal temperatures with some viral infections). 2) Fatigue. 3) Headache. 4) Anorexia and nausea. 5) Malaise and myalgia (ie. joint and muscle pain). CLINICAL MANAGEMENT Antibiotics, Antimicrobials, Antivirals, Antifungals Sanitation Primary Prevention Infection prevention and control Hand Hygiene Food Safety Public Health Initiatives Vaccination Secondary Prevention Screening LAB VALUES FOR INFECTION (GIDDENS, 2021, P.235) Biochemistry Sodium – dehydration Potassium – GI infection (diarrhea/vomiting) Creatinine – perfusion to kidneys (hypovolemia) Lactate (sign of sepsis/MSOF) Complete Blood Count White Blood Cell Count Elevated B and T lymphocytes, neutrophils, monocytes = bacterial or viral Elevate basophils/eosinophils = parasitic Culture and Sensitivity Urine, sputum, throat, blood, wounds, spinal fluid Equipment Other ESR Antibody tests: Hepatitis, HIV The erythrocyte sedimentation rate (ESR) is a blood test that can help detect inflammation in the body. It measures how quickly red blood cells settle at the bottom of a test tube over a specified period, typically one hour. A higher-than-normal ESR suggests that there is inflammation in the body. A normal ESR value suggests there is no significant inflammation detected by this test Increased Potassium (Hyperkalemia): High levels of potassium in the blood typically do not cause GI infections. Hyperkalemia can result from various conditions, including kidney dysfunction, medications, or excessive potassium intake. While it can cause symptoms like nausea or changes in bowel movements due to muscle and nerve function disturbances, it doesn't induce GI infections. Decreased Potassium (Hypokalemia): Low potassium levels can affect the GI system by reducing its motility, potentially leading to issues like constipation or bloating. While these symptoms can affect a person's comfort and digestion, they do not cause GI infections. Hypokalemia can result from conditions that might involve the GI tract, such as prolonged vomiting or diarrhea, but these are symptoms or causes of the low potassium, not the result of it. If there is an infection that affects the kidneys or decreases their perfusion (blood flow to the kidneys), the creatinine value in the blood would typically be high. Creatinine is a waste product that kidneys filter out of the blood. When the kidneys are not functioning properly due to reduced blood flow or damage (which can happen with severe infections), they can't filter creatinine efficiently, leading to an increase in its blood levels. Thus, a high creatinine level can indicate that the kidneys are under stress or not working well, potentially due to an infection or other causes affecting their perfusion or function. If there's an infection, particularly a severe one that leads to decreased oxygen delivery to tissues (as in septic shock or severe bacterial infections), the lactate level in the blood can become high. Lactate is a byproduct of anaerobic metabolism, which is the process cells use to generate energy when there isn't enough oxygen available. During a severe infection, if tissues aren't getting enough oxygen due to impaired blood flow or inflammation, cells switch to anaerobic metabolism, producing more lactate. High levels of lactate in the blood, therefore, can be a sign of this kind of metabolic stress and are often used as an indicator of the severity of an infection or shock, suggesting that the body's tissues are not receiving adequate oxygen ANTIINFECTIVE THERAPY FOCUS ON ANTIBIOTIC WE DO NOT USE ANTIBIOTICS ON PARASITES, VIRUSES, FUNGI…. Classification by Susceptible Organism (Lehne, 2021,Table 87.1- p.1021) CLASSIFICATION OF ANTIBIOTIC DRUGS Narrow Spectrum: active against a few specific organisms Broad Spectrum: active against a wide variety of organisms Classification by Mechanism of Action (Lehne, 2021, p.1021-1022) Bacteriostatic Bactericidal HOW ANTIBIOTICS WORK: BACTERIO-STATIC VS BACTERIOCIDAL https://cdn.technologynetworks.com/tn/images/body/g-pos-gneg-cell-wall-structure-final1566305996142.jpg http://laboratoryinfo.c om/wpcontent/uploads/2015/ 03/bacteria-types.jpg Susceptible Organism Narrow Spectrum: active against a few specific organisms Broad Spectrum: active against a wide variety of organisms Mechanism of Action CLASSIFICATION OF ANTIMICROBIAL DRUGS Inhibit bacterial cell wall synthesis or activate enzymes that disrupt the cell well Increase cell membrane permeability Cause lethal inhibition of bacterial protein synthesis (Bactericidal) Cause nonlethal inhibition of protein synthesis (Bacteriostatic) Inhibit bacterial synthesis of DNA and RNA or disrupt DNA function Antimetabolites Suppress viral replication ADMINISTERING ANTIBIOTIC THERAPY. WHAT DO WE NEED TO KNOW AS NURSES? What bacteria does it impact? Mechanism of action? Narrow or broad spectrum? Gram +ve or Gram –ve bacteria targeted? Assessment prior, during, after administration Side effects Monitoring (e.g serum drug levels) Client teaching PENICILLINS PENICILLIN G MOA: weaken cell wall causing bacteria to take up excessive amounts of water and rupture Broad and narrow spectrum Most common cause of drug allergy Side effects: Superinfections (C.Diff), diarrhea, nausea, vomiting, abdominal cramping Contraindications: Allergy, renal impairment, drug interactions with aminoglycosides Nursing considerations: Assess allergies, monitor kidney function (creatinine & urine output), instruct to take full prescribed treatment (drug resistance), evaluate effects (reduction in fever/pain/inflammation) Monitoring creatinine levels and urine output is crucial when administering penicillin to ensure that the kidneys are functioning properly and to avoid drug accumulation and potential kidney damage. Because penicillin and its derivatives are primarily excreted through the kidneys, monitoring creatinine helps ensure that the kidneys can effectively eliminate the drug. If kidney function is impaired (evidenced by increased serum creatinine levels), penicillin could accumulate in the body, potentially leading to toxicity. Creatinine levels provide insight into kidney health and help in adjusting medication dosages to prevent toxicity,while urine output is a direct indicator of kidney filtration efficacy. This monitoring is especially important in patients with pre-existing kidney issues or those receiving high doses of penicillin, to prevent any kidney-related side effects. CEPHALOSPORINS MOA: Bactericidal Broad spectrum 5 generations (classes) with respect to antimicrobial spectrum Contraindications: Allergies (1% of penicillin allergies react to cephalosporins), bleeding disorder, caution with anticoagulants/thrombolytics/antiplatelets/NSAID Side effects: Bleeding (Reduce prothrombin levels), superinfections (C.diff), diarrhea, abdominal cramping, alcohol intolerance Nursing considerations: Assess allergies or hx of bleeding disorders, monitor INR, instruct on no alcohol intake, instruct to take full prescribed treatment (drug resistance), evaluate effects (reduction in fever/pain/inflammation) CEFAZOLIN (ANCEF) INR is monitored in patients treated with cephalosporins to detect any adverse effects on blood clotting and to prevent potential bleeding complications, ensuring safe and effective use of these antibiotics. MACROLIDES MOA: Inhibit bacterial protein synthesis (Bacteriostatic) Broad spectrum 1st choice for pts with penicillin allergies Side effects: epigastric pain, nausea, vomiting, diarrhea, superinfections (C.Diff), QT prolongation/sudden cardiac death, hepatoxicity Contraindications: Congenital QT prolongation/arrhythmias, drug interactions with many drugs (calcium channel blockers/digoxin/warfarin), hepatoxicity Nursing considerations: assess allergies, need to monitor drug levels/LFTs, assess for hx of heart disease, rashes (Steven-Johnson syndrome), do not take with grapefruit juice, instruct to take full prescribed treatment (drug resistance), evaluate effects (reduction in fever/pain/inflammation) ERYTHROMYCIN QT prolongation refers to an extended interval between the Q wave and the T wave on an electrocardiogram (ECG), which represents the time it takes for the heart to depolarize and repolarize, or in simpler terms, for the heart's electrical system to reset after each beat. This condition can increase the risk of developing an abnormal and potentially dangerous heart rhythm called torsades de pointes, which can lead to sudden cardiac arrest. STEVEN JOHNSON’S SYNDROME https://usercontent1.hubstatic.com/8571388.jpg TETRACYCLINES: MOA: Suppress bacterial growth (Bacteriostatic) Broad spectrum Side effects: epigastric burning, cramps, nausea, vomiting, diarrhea, superinfections (C.diff/Candida), teeth discoloration (binds to calcium) and hypoplasia of enamel(4m-8yr), hepatotoxicity, photosensitivity, bleeding DOXYCYCLINE INR: Patients on warfarin may need monitoring due to potential interactions with any antibiotic, including doxycycline, which could affect blood clotting. LFTs: Those with pre-existing liver conditions or using other hepatotoxic drugs might need their liver function checked since doxycycline can rarely cause liver toxicity. Creatinine: In patients with significant renal impairment, monitoring kidney function ensures that doxycycline doesn't accumulate to harmful levels, as it's primarily excreted by the kidneys. Contraindications: under 8yrs, liver or renal impairment, drug interactions with digoxin/anticoagulants/oral contraceptives, avoid milk products/calcium & iron supplements/magnesium laxatives/antacids Nursing considerations: assess allergies, administer 1hr before or 2hrs after ingestion of milk/supplements, monitor creatinine/LFTs/INR, instruct to take full prescribed treatment (drug resistance), evaluate effects (reduction in fever/pain/inflammation) AMINOGLYCOSIDES: GENTAMICIN Serum drug trough levels are measured to ensure that a medication remains within its effective and safe concentration range in the blood. These levels help healthcare providers adjust dosing to optimize therapeutic effects and minimize toxicity, particularly for medications that require precise dosing management. Monitoring is crucial for maintaining consistent and effective drug therapy. MOA: disrupt bacterial protein synthesis (Bactericidal) Narrow spectrum Reserved for serious systemic infections Side effects: ototoxicity, nephrotoxicity, superinfections (C.diff), neuromuscular blockade (flaccid paralysis/resp depression) Contraindications: Impaired hearing, renal impairment, caution with nephrotoxic drugs, caution with ototoxic drugs: furosemide/vancomycin Nursing considerations: assess for allergies, baseline audiometry in high risk, monitor creatinine and serum drug troughs, monitor urine output, instruct to take full prescribed treatment (drug resistance), evaluate effects (reduction in fever/pain/inflammation) MOA: Inhibits DNA synthesis by inhibiting to bacterial enzymes (bactericidal) Narrow and Broad spectrum FLUROQUINOLONES Side effects: GI (nausea, vomiting, diarrhea, abdominal pain), CNS (dizziness, restlessness, confusion), superinfections (C.diff, Candida), tendon rupture, phototoxicity, hepatotoxicity, Guillian-Barre syndrome CIPROFLOXACIN (CIPRO) Contraindications: under 18 yr old, Myasthenia gravis, renal impairment, drug interactions with antacids/minerals/vitamins/calcium components Nursing considerations: assess allergies, monitor CNS/muscular effects, educate about sun exposure, monitor for tendon pain/swelling, monitor LFTs, instruct to take full prescribed treatment (drug resistance), evaluate effects (reduction in fever/pain/inflammation) Guillain-Barré syndrome (GBS) is a rare neurological disorder in which the body's immune system mistakenly attacks part of its peripheral nervous system—the network of nerves located outside of the brain and spinal cord. This can lead to muscle weakness, numbness, and even paralysis. Myasthenia gravis is an autoimmune disorder characterized by weakness and rapid fatigue of the voluntary muscles. Phototoxicity refers to a skin reaction that occurs when certain chemical substances in the skin are activated by exposure to light, typically ultraviolet (UV) light from the sun or artificial sources. MOA: suppress bacterial growth by inhibiting protein/DNA/RNA synthesis (Bacteriostatic) Broad spectrum Side effects: GI (nausea, vomiting), blood dyscrasias, kernicterus (newborns), crystalluria (renal failure), photosensitivity, Steven Johnson syndrome (rash) SULFONAMIDES Contraindications: drug interactions with warfarin/phenytoin/oral TRIMETHOPRIM/SULFAMETHOXAZOLE antihyperglycemics Nursing considerations: Assess and monitor for anemia and other hematological disorders, avoid exposure to direct sunlight, monitor urine output/creatinine levels, instruct to take full prescribed treatment (drug resistance), evaluate effects (reduction in fever/pain/inflammation) Stevens-Johnson syndrome (SJS) is a rare, serious condition that affects the skin and mucous membranes, often triggered by a reaction to medication or an infection. ANTIBIOTIC RESISTANT BACTERIA Antibiotic Resistance Occurs when bacteria continue to grow in the presence of the drug Innate Resistance: penicillin innately does not work very well on Gram-negative bacteria since these bacteria have very little cell wall. Acquired Resistance: when penicillin can no longer kill Grampositive cocci, this resistance is said to be acquired. This resistance is passed on to the cells progeny and creates a resistant strain. Innate Resistance: This refers to the natural, built-in mechanisms that allow bacteria to resist the effects of antibiotics or other antimicrobial agents without prior exposure. For example, a bacterial species might have a naturally impermeable cell wall that prevents certain antibiotics from entering and exerting their effects. Acquired Resistance: This occurs when bacteria develop resistance to an antibiotic after being exposed to it. This can happen through mutations or by acquiring resistance genes from other bacteria. The resistance is not present from the start but is gained through adaptation or genetic changes. ACQUIRED ANTIBIOTIC RESISTANCE CONTINUED: How does a bacteria acquire resistance? Four common mutations are: 1. The bacteria decrease the concentration at the drug site of action 2. The bacteria produce a drug antagonist 3. The bacteria alter the structure of drug target molecules 4. The bacteria cause drug inactivation Decrease the Concentration at the Drug Site of Action: The bacteria change in a way that prevents the antibiotic from reaching its target site within the bacterial cell. It's like the bacteria close their doors and windows so the antibiotic can't get inside. Produce a Drug Antagonist: The bacteria develop the ability to make a substance that fights against the antibiotic, effectively canceling its effects. Imagine the antibiotic as a key trying to unlock a door to kill the bacteria, but the bacteria create a block that jams the lock. Alter the Structure of Drug Target Molecules: The target within the bacteria that the antibiotic usually attacks is changed. It's like the bacteria change their locks so the key (the antibiotic) no longer fits. Cause Drug Inactivation: The bacteria gain the ability to break down the antibiotic or make it inactive, similar to how an enzyme might digest food. It's as if the bacteria find a way to snap the key (the antibiotic) in half, making it useless. https://cdn.kastatic.org/kaperseusimages/b53bdd5064e93acd3d 897743c78e968b64b59a6a.pn g RESISTANCE → SELECTION Resistance develops through random mutations that are occasionally advantageous resulting in survival. S S S S S S S S S S S S S Selection: By killing susceptible strains of a bacterial population through excessive use of antibiotics, resistant strains are allowed to survive and eventually dominate that bacterial population. Infections acquired in a hospital or other healthcare setting, called nosocomial infections are often resistant to common antibiotics. S R S Apply antibiotic: Get Selection R R R R R R R R R R R 1. Describe the general concept of immunity (Giddens concept) 2. Describe the general concept of infection (Giddens concept) 3. 4. SUMMARY Explain the common pathophysiological mechanisms and impact of an altered immune response and infection Compare and contrast the 4 types of hypersensitivity reactions 5. Describe the principles, practices and processes underlying health assessment of an altered immune response and infection 6. Apply the pharmacokinetics, pharmacodynamics, and pharmacotherapeutics of common therapy targeted to an altered immune response and common therapy targeted to infection using exemplars 7. Apply Nursing Process/Clinical Judgment/Systems thinking (as described in Class 1) to the patient experiencing an altered immune response