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NUR 204: EXAM 1 COMPLETE STUDY GUIDE SECTION 1: CANCER PATHOPHYSIOLOGY & EPIDEMIOLOGY Cellular Characteristics • Cancer is uncontrolled cell growth caused by genetic damage. • Apoptosis: The body's natural ability to destroy abnormal or cancerous cells. Malignant cells fail to undergo apoptosis. • Angiogenesis: Malignant cells can create their own blood supply for nourishment, making them very difficult to eliminate. • Progression to Malignancy: Hyperplasia (rapid increase in normal cells) → Dysplasia (abnormal cells) → Carcinoma in situ (localized cancerous cells) → Malignancy. Tumor Types & Staging • Primary vs. Secondary: The primary tumor is where the cancer originated. Secondary tumors are the sites of metastasis (e.g., lung cancer that spreads to the liver means the liver contains secondary tumors). • TNM Staging System: o T = Tumor size. o N = Lymph Node involvement. o M = Metastasis (Spread). • Number Staging (0-4): Stage 0 (In situ, abnormal cells haven't spread) to Stage IV (Distant metastasis, spread to distant body parts). Risk Factors & Prevention (Live Lecture Focus) • Modifiable vs. Non-modifiable: Age, genetics (BRCA mutations), and gender are non-modifiable. Smoking, alcohol, obesity, and sedentary lifestyle are modifiable. • Environmental Factors: o Physical: UV light (tanning beds), radiation. o Chemical: Tobacco, alcohol, workplace pesticides/cleaners. o Biological: Viral infections (HPV causes cervical cancer, Hep B/C causes liver cancer), poor diet. • Nurse's Role in Community Screenings: Skin cancer screenings are highly effective for community health fairs because they are non-invasive. Screening Guidelines • Breast: Mammograms starting at age 40 (earlier if high risk). • Colorectal: Colonoscopy every 10 years starting at age 45. • Prostate: PSA blood screening at age 50. • Tumor Markers: PSA (Prostate) and BRCA1/BRCA2 (Breast). SECTION 2: IMPACT OF CANCER & NURSING CARE Physiological Impacts • Pain: Very common, affecting up to 80% of advanced cancer patients. • Infection/Neutropenia: Dangerously low white blood cells. Live Lecture Note: Any spike in temperature (even a low-grade fever like 100.4°F) is a massive red flag for impending sepsis and must be addressed immediately. • GI Issues: Nausea, vomiting, and mucositis (painful mouth inflammation). For mucositis: avoid spicy/acidic foods and use lidocaine rinses. Cognitive & Psychosocial Impacts • Delirium (HIGH YIELD): Acute, sudden confusion. Live Lecture Note: Delirium is reversible. The nurse must treat the underlying cause. Interventions include reorienting the patient, clustering care, avoiding interruptions, and simulating day/night to regulate circadian rhythms (lights on during the day, off at night). • Financial & Psychosocial: Cancer treatments are grueling and expensive, leading to lost employment and depression. Nurses should facilitate early referrals to social workers and case managers. Nursing Safety & Medication Administration • Extravasation Safety: Vesicant chemotherapy drugs can severely damage tissue if they leak outside the vein. Live Lecture Note: If chemo is given via a peripheral IV, the nurse MUST check for blood return every single hour to prevent extravasation. If extravasation occurs: stop the infusion immediately. • Chemotherapy PPE: The nurse must wear proper PPE (e.g., double gloves, chemo gown, face protection) and dispose of chemo materials in designated hazardous waste bins (e.g., yellow bins). • Neutropenic Precautions (Reverse Isolation): Protecting the highly vulnerable patient from the nurse/visitors. Includes strict hand hygiene, no sick visitors, and avoiding crowds. SECTION 3: ONCOLOGIC EMERGENCIES • Spinal Cord Compression: Early signs include back pain, muscle weakness, loss of sensation, and bowel/bladder incontinence. • Brain Metastasis/Increased ICP: Personality changes, seizures, altered speech/balance. • Hypercalcemia: Confusion, severe muscle weakness, arrhythmias, and ECG changes. • Superior Vena Cava (SVC) Syndrome: Tumor compresses the SVC causing facial/neck edema and dyspnea. • Tumor Lysis Syndrome (TLS): Rapid cell death causes severe electrolyte imbalances (hyperkalemia, hyperuricemia). • SIADH: Tumor triggers excessive antidiuretic hormone (ADH), leading to massive water retention, dilutional hyponatremia, and confusion. SECTION 4: SELECTED CANCERS Lymphedema What is it? A frequent cancer treatment complication where fluid builds up in an extremity (typically on one side), causing severe swelling. • Signs & Symptoms: Swelling, a feeling of heaviness, decreased range of motion, and tightness in the skin. • Common complication of: Breast cancer treatments, specifically resulting from lymph node dissection/removal, radiation therapy, or chemotherapy. • Nursing Priorities & Treatment: o Elevate the affected arm above heart level. o Use compression sleeves as prescribed. o Encourage range-of-motion exercises to prevent stiffness. o ABSOLUTE SAFETY RULE: NO blood pressures, NO IVs, and NO blood draws on the affected arm. • Breast Cancer: o Live Lecture Note: Ductal breast cancer is the most common type (originating in the milk ducts). o Signs: Hard mass, nipple retraction, "orange peel" skin (peau d'orange). o Hormone Receptors: If the tumor is estrogen-receptor positive, treatment must avoid estrogen as it will feed the tumor. o Lymphedema Care: Swelling in the arm due to lymph node removal. Rule: No blood pressures, IVs, or blood draws on the affected arm. Elevate the arm and use compression. • Lung Cancer: o Live Lecture Note: Often asymptomatic in the early stages, leading to late diagnosis. o Signs: Chronic cough, hemoptysis (rust-colored/bloody sputum), dyspnea. High risk for brain metastasis. • Colorectal Cancer: o Live Lecture Note: A hallmark sign is "ribbon-like" or pencil-thin stool, caused by a tumor pressing in the rectum and narrowing the passageway. Other signs: rectal bleeding, changes in bowel habits, anemia. • Pancreatic Cancer (HIGH MORTALITY): o Live Lecture Note: High mortality because early symptoms are incredibly vague; usually caught too late. o Whipple Procedure: Surgery that removes the head of the pancreas but leaves a portion behind so the patient retains some insulin secretion. Nursing Priority: You must strictly monitor for manifestations of diabetes (hypo/hyperglycemia) because pancreatic function is deeply impaired. • Skin Cancer: o Types: Basal cell (slow-growing, sun-exposed areas), Squamous cell (more serious), Melanoma (most deadly, highly metastatic). o Melanoma ABCDEs: Asymmetry, Border irregularity, Color variation, Diameter >6mm, Evolving. • Brain Tumors: o Live Lecture Note: Primary brain tumors are typically benign. Malignant brain tumors have usually metastasized from somewhere else. SECTION 5: INFLAMMATION & IMMUNITY BASICS • Acute vs. Chronic Inflammation: Acute is short-term and protective (redness, heat, swelling, pain). Chronic is prolonged, causing tissue damage. Exam Tip: Chronic inflammation heavily increases the risk for cardiovascular disease. • Infection vs. Inflammation: Inflammation does not always mean infection (e.g., sprains, allergies). Systemic infection signs include fever, tachycardia, and confusion. Rule: Always draw a blood culture before starting antibiotics. SECTION 6: AUTOIMMUNE & INFLAMMATORY DISORDERS Detailed Osteoarthritis (OA) (Live Lecture Focus) • Pathophysiology: OA is a degenerative joint disease causing progressive cartilage breakdown. It is characterized by the friction of "bone on bone" as cartilage degenerates, which leads to the formation of bone spurs and bone cysts (fluid-filled cavities). • Key Distinction: There is NO systemic inflammation; OA is localized to the affected joints. • Risk Factors: Natural wear and tear of aging, trauma, joint overuse (e.g., repetitive work or sports), obesity, genetics, and a sedentary lifestyle. • Complications: Because OA causes a lack of mobility and a sedentary lifestyle, patients are at a highly increased risk for cardiovascular disease, diabetes, and obesity. Patients over 65 should also be screened for iron overload (hemochromatosis), which can accelerate the progression of OA. Patients are also at high risk for depression and anxiety due to loss of independence and chronic pain. • Signs & Symptoms: Joint pain, stiffness, crepitus (cracking of the joints), muscle atrophy, and limited range of motion. • Treatment: o Non-surgical first: Physical therapy, exercise (specifically swimming/water exercises to take pressure off the joints), and weight loss. o Medications: Acetaminophen (monitor for liver toxicity), NSAIDs like ibuprofen/naproxen (monitor for kidney toxicity), and cortisone injections into the joint. o Surgical: Joint replacement (e.g., hip or knee). Nursing Priority: Ambulate the patient right away after surgery to prevent complications. Detailed Rheumatoid Arthritis (RA) (Live Lecture Focus) • Pathophysiology: A chronic autoimmune disease where the body's immune system mistakenly attacks the synovial tissue and fluid in the joints. • Risk Factors: Increased age (highest onset in the 60s), genetics, females (especially those who have never given birth), obesity, smoking, and high stress. o Trigger mechanism: Someone with a genetic susceptibility who experiences an external trigger (like an infection or trauma) can kickstart the autoimmune reaction. • Signs & Symptoms: Symmetric joint swelling and pain (usually in the hands and feet), morning stiffness lasting longer than 1 hour, fever, malaise, and weakness. Patients experience flare-ups (severe symptoms) and remissions (no symptoms). • Rheumatoid Nodules: The most common visible manifestation of RA. These are detachable, movable subcutaneous knots or swellings of varying sizes, typically found in the fingers/hands. • Diagnostics: Elevated ESR and C-reactive protein (CRP) indicate inflammation. Positive Rheumatoid Factor (RF) and ANA (anti-nuclear antibody) blood tests. • Medications & Safety: o Treated with DMARDs (Disease-Modifying Antirheumatic Drugs). o Priority: DMARDs suppress the immune system, putting the patient at a severe risk for infection. o Hydroxychloroquine teaching: Long-term use can cause retinal damage and glaucoma leading to blindness; patients MUST see an optometrist regularly for eye exams. Systemic Lupus Erythematosus (SLE): • Multisystem autoimmune disease attacking self-tissues. • Symptoms: Butterfly rash on the face, photosensitivity, joint pain. • Complications: Cardiovascular disease (pericarditis) and kidney failure (lupus nephritis). • Triggers: Teach patients to avoid UV light/sun exposure, severe stress, exhaustion, and infections to prevent flare-ups. Peritonitis (LIFE THREATENING): • Inflammation of the peritoneum (abdomen). • Symptoms: Rigid, board-like abdomen, rebound tenderness. • Complication: Septic shock and death. SECTION 7: HIV / AIDS & HYPERSENSITIVITY HIV/AIDS: • A retrovirus that specifically targets and destroys CD4 T-cells. • Transmission Phase: The virus is most highly infectious during the initial phase when the viral load is the highest. • Opportunistic Infections: When CD4 drops < 200 (AIDS), the patient is at extreme risk for deadly infections like Tuberculosis, Pneumocystis pneumonia (PCP), and Kaposi sarcoma. • PrEP (Pre-Exposure Prophylaxis): Reduces risk of contracting HIV but does NOT replace safe sex practices (condoms). Risk Factors & At-Risk Populations: o Individuals with multiple sexual partners without protection, and those who share IV drug needles. o Substance use (drugs/alcohol) is a major risk factor because it lowers inhibitions, leading to unprotected sex. o Incarcerated populations or those in closed settings (due to sharing needles, self-tattooing, and sexual violence). o Pregnant or lactating women (due to the risk of perinatal transmission). Phases of HIV Progression: 1. Acute Infection Phase: Occurs 2 to 4 weeks after exposure. The risk of transmission is at its absolute highest because the viral load in the blood is massive. Patients exhibit flu-like symptoms (fever, malaise, fatigue). 2. Chronic Infection Phase: Patients are often asymptomatic, meaning they may not even realize they are infected. They can still transmit the virus if their viral load is high enough. This stage can last for a decade or longer. 3. AIDS: If left untreated, HIV progresses to AIDS. Diagnosis is confirmed when the CD4 T-cell count falls below 200. Immune system damage is severe, creating a very high risk for fatality and opportunistic infections (such as Tuberculosis, Kaposi sarcoma, and fungal infections). • PrEP vs. PEP (Crucial Difference): o PrEP (Pre-Exposure Prophylaxis): Medication taken prophylactically to prevent the transmission of HIV to an HIV-negative person. It does NOT replace safe sex practices (condoms must still be used). o PEP (Post-Exposure Prophylaxis): Medication taken after accidental exposure (e.g., a broken condom, a needle stick injury, or sexual assault). It MUST be taken within 72 hours of exposure to be effective. It is taken daily for 28 days and is not meant for regular, ongoing use. Anaphylaxis: • Severe allergic reaction triggering massive histamine release. • Patho: Causes increased capillary permeability, where blood vessels leak fluid into the tissues, leading to profound hypotension and airway edema. • Priority Treatment: Epinephrine IM. • High-Risk Factor: Patients taking Beta-blockers or Alpha-adrenergic blockers are at a high risk of death because these medications reduce the effectiveness of epinephrine, preventing the reversal of the shock. SECTION 8: INFECTIONS & SAFETY PROTOCOLS Meningitis (SAFETY RULE): • Diagnosed via Lumbar Puncture (testing CSF). • Live Lecture Safety Rule: If the patient shows signs of Increased Intracranial Pressure (ICP) (like severe headache, altered mental status), a CT scan of the head MUST be performed BEFORE a lumbar puncture. Performing a lumbar puncture when ICP is high can cause fatal brain herniation. • Risk Groups: College dorm students, unvaccinated individuals. Lumbar Puncture (Live Lecture Safety Rules) • Purpose: To draw out and test the cerebrospinal fluid (CSF) specifically to screen for and confirm a diagnosis of meningitis. • Position: The patient should be laying on their side with their knees pulled to their chest (fetal position) to help open up the spinal column for needle insertion. • Contraindication & Safety Priority: A lumbar puncture is completely contraindicated if the patient has Increased Intracranial Pressure (ICP). o Rule: A CT scan of the head MUST be performed BEFORE a lumbar puncture to rule out increased ICP. Performing a lumbar puncture on a patient with increased ICP can cause fatal brain herniation Sinusitis: • Inflammation of the sinuses causing facial pressure ("like you got punched in the face"), congestion, and post-nasal drip. • Live Lecture Rule: Treat with hydration, nasal irrigation, and steam. AVOID over-the-counter antihistamines and decongestants because they cause rebound inflammation (making symptoms worse when they wear off). Influenza: • FACTS Mnemonic: Fever, Aches, Chills, Tiredness, Sudden onset. High risk for secondary pneumonia in older adults and pregnant women. SECTION 9: MEDICATIONS HIGHLIGHTED IN LIVE LECTURE 1 Your instructor specifically highlighted these medications and their nursing implications during the recorded lectures: 1. Analgesics & Anti-inflammatories • Opioids (Cancer Pain): A major side effect is delayed gastric emptying and severe constipation. Intervention: Administer stool softeners, encourage hydration and mobility. Monitor for decreased respirations and drowsiness (which creates a fall risk). • Acetaminophen (Tylenol): Used for mild OA pain. Warning: Hepatotoxic (toxic to the liver) if too much is given. • Ibuprofen/Naproxen (NSAIDs): Used for OA/RA inflammation. Warning: Nephrotoxic (toxic to the kidneys) and can cause GI bleeding. • Corticosteroids (Cortisone): Can be injected directly into joints for OA inflammation. 2. Neurological & Emergency Medications • Mannitol: An osmotic diuretic used specifically to lower elevated Intracranial Pressure (ICP) in patients with brain tumors. • Phenytoin & Levetiracetam (Keppra): Anti-epileptic medications used to prevent seizures in patients with brain metastasis/tumors. • Epinephrine: The absolute first-line priority treatment for anaphylaxis. Works to constrict blood vessels and open the airway. • Hydroxychloroquine (DMARD): Used for RA and Lupus. Warning: Can cause retinal toxicity. Patients require regular eye exams (every 6 months) and must use photosensitivity precautions. SECTION 10: SAMPLE QUESTIONS & ANSWERS Q1: The client’s cancer is staged as T1, N2, M1 according to the TNM classification system. How would the nurse interpret this staging? A. One tumor that is nonresponsive to treatment with distant metastasis B. Leukemia indicated that is confined to the bone marrow C. A 2-cm tumor with one regional lymph node involved and no distant metastasis D. Small tumor with extension into two lymph nodes and one site of distant metastasis Answer: D. Rationale: T = small primary tumor, N = extension to regional lymph nodes, M = distant metastasis has occurred. Q2: The nurse is assessing an older client at a checkup visit. Which reported change would alert the nurse to the possibility of colon cancer? A. Pencil-thin stool B. Erectile dysfunction C. Reduced urine stream D. Persistent pain in the lower back and legs Answer: A. Rationale: Tumors growing in the colon/rectum compress the passageway, resulting in ribbon-like or pencil-thin stool. Q3: A nurse is performing a cancer screening assessment on several clients. Which of the following findings is a possible manifestation of cancer? (Select all that apply) A. Temperature 36° C (96.8° F) B. Sore that does not heal C. Difficulty swallowing D. Blood in the urine E. Rhinitis Answer: B, C, D. Rationale: Using the CAUTION mnemonic, signs include sores that do not heal, difficulty swallowing, and unusual bleeding/discharge. Q4: A nurse is caring for a client who has breast cancer. The client asks why the treatment plan contains a combination therapy of three different medications. Which of the following responses should the nurse make? (Select all that apply) A. “Combination chemotherapy decreases the risk of medication resistance.” B. “Combination chemotherapy attacks cancer cells at different stages of cell growth.” C. “Combination chemotherapy increases production of platelets.” D. “Combination chemotherapy stimulates the immune system.” Answer: A, B. Rationale: Using multiple chemo drugs reduces drug resistance and attacks the cell at various phases of the cell cycle. Q5: A nurse is caring for a burn client whose calculated 24-hour intravenous fluid requirements are determined to be 5000 mL. What is the total volume (mL) that the nurse should infuse after the first 8 hours of fluid resuscitation has infused? Answer: 2500 mL. Rationale: Standard burn fluid resuscitation protocols require half (50%) of the 24-hour total to be administered in the first 8 hours following the burn injury. Q6: The nurse is caring for a client who has a systemic infection. What is the best method to prevent infection transmission? A. Obtaining an immunization B. Implementing proper hand hygiene C. Wearing gloves D. Managing the client’s fever Answer: B. Rationale: Strict hand hygiene remains the most effective method for preventing the transmission of infectious organisms. Q7: The nurse is assessing a client with systemic lupus erythematosus (SLE). Which of the following laboratory findings should the nurse anticipate? (Select all that apply) A. Positive ANA titer B. Increased hemoglobin C. Pancytopenia D. Urine positive for protein and RBCs Answer: A, C, D. Rationale: SLE causes an autoimmune response (Positive ANA), bone marrow suppression (pancytopenia), and lupus nephritis, which damages the kidneys causing protein and blood to spill into the urine. Q8: A nurse is providing teaching to a client who is to receive a vaccination following a deep puncture wound to the foot. Which information would the nurse include? A. “You will need to receive this vaccination annually.” B. “Your passive immunity will be boosted by receiving this shot.” C. “I am administering this vaccination to help protect you against tetanus.” D. “This immunization requires three separate injections several weeks apart.” Answer: C. Rationale: Tetanus vaccination is indicated for deep puncture wounds. Q9: A nurse is assessing a client who is being treated with interferon alfa-2b for malignant melanoma. The nurse should identify that which of the following findings are adverse effects of this medication? (Select all that apply) A. Tinnitus B. Muscle aches C. Peripheral neuropathy D. Bone loss E. Depression Answer: B, C, E. Rationale: Interferon therapy causes significant flu-like symptoms (muscle aches, chills), peripheral neuropathy, and mood changes including severe depression. Q10: A nurse is reviewing the medical record of a client. Which of the following findings are risk factors for ovarian cancer? (Select all that apply) A. Previous history of endometriosis B. Family history of colon cancer C. First pregnancy at age 24 D. First period at age 14 E. Use of oral contraceptives for 10 years Answer: A, B. Rationale: Endometriosis and a family history of associated cancers (like colon or breast BRCA mutations) increase the risk for ovarian cancer. (Pregnancy and oral contraceptive use typically decrease the risk). Q11: The nurse is caring for a client whose white blood cell count is 6000/mm3. Which differential value would the nurse discuss with the health care provider? A. Eosinophils 700/mm3 (Reference range: 50–400/mm3) B. Monocytes 500/mm3 (Reference range: 100–800/mm3) C

Objectives come from your Unit 3 sheet and the content/examples come from the PowerPoints . ⸻ UNIT 3 COMPLETE STUDY GUIDE (Based strictly on your slides + objectives) ⸻ CHAPTER 11 — CONTROLLING MICROBIAL GROWTH Difference Between Antisepsis, Disinfection, Sanitization, Sterilization, Degerming, Decontamination Sterilization Complete destruction of all microbial life including viruses and endospores. Examples from slides: • Surgical instruments • Syringes • Packaged foods Endospores must be destroyed for something to be considered sterile. ⸻ Disinfection Destroys most vegetative pathogens on nonliving surfaces. Examples: • Disinfecting medical equipment • Hospital surfaces ⸻ Antisepsis Use of antimicrobial chemicals on living tissue. Examples: • Skin prep before surgery • Cleaning wounds ⸻ Degerming Mechanical removal of microbes by scrubbing. Example: • Handwashing ⸻ Sanitization Reduces microbial numbers to public health safe levels. Examples: • Cleaning food preparation surfaces • Restaurant sanitation ⸻ Decontamination General removal of microbes from objects or surfaces. Example: • Cleaning contaminated hospital equipment ⸻ Difference Between Static and Cidal Cidal Kills microbes. Example Bactericidal antibiotics. ⸻ Static Stops growth but does not kill. Example Bacteriostatic antibiotics. ⸻ Variables That Influence Effectiveness of Antimicrobial Methods 1. Population size Large populations require more time to kill. 2. Nature of microbes Some microbes are more resistant. Example: Bacterial endospores. 3. Temperature Higher temperature increases killing. 4. Concentration of agent 5. Contact time 6. Organic matter present Example: Blood or mucus interfering with disinfectants. 7. Mode of action of agent 8. Biofilms Biofilms protect microbes from antimicrobials. ⸻ Most Resistant vs Least Resistant Microbes Most resistant: Bacterial endospores Reason: Thick protective layers. ⸻ Less resistant: • Mycobacteria • Gram-negative bacteria • Gram-positive bacteria • Fungi • Viruses Endospores are the target of sterilization methods. ⸻ Mechanisms of Antimicrobial Agents Agents work by damaging: Cell wall Example Detergents and alcohol disrupt cell wall. ⸻ Cell membrane Effects • Loss of permeability • Leakage of molecules ⸻ Proteins Agents denature proteins. Examples • Heat • Alcohol • Strong acids ⸻ DNA and RNA Example Radiation damaging DNA. ⸻ Practical Concerns When Choosing Control Method Consider: • Does item require sterilization or disinfection? • Can item tolerate heat, pressure, radiation, chemicals? • Cost effectiveness • Safety • Ability of agent to penetrate surfaces. ⸻ PHYSICAL AND MECHANICAL METHODS ⸻ Pasteurization vs Sterilization Pasteurization: Reduces microbial numbers but does not sterilize. Used for: Milk and beverages. Sterilization: Destroys all microbes including endospores. ⸻ Boiling Kills many pathogens but may not destroy endospores. ⸻ Autoclaving Uses steam under pressure. Conditions from slides: 121°C 15 minutes 15 psi Mechanism: Denatures proteins and disrupts metabolism. ⸻ Most Rigorous Heat Method Incineration (dry heat) Burns microbes completely. ⸻ Ionizing Radiation vs UV Radiation Ionizing radiation Examples: Gamma rays X-rays Effect: Destroys DNA and proteins. Highly penetrating. ⸻ UV radiation Example: Germicidal lamps. Mechanism: Forms pyrimidine dimers (thymine dimers). Effect: DNA replication blocked. ⸻ Filtration Removes microbes from liquids or air. Examples: • Water purification • Milk filtration • Air filtration systems • HEPA filters • N95 masks HEPA filters remove 99.97% of particles. ⸻ Osmotic Pressure High salt or sugar removes water from microbes. Examples: Salt: Cured meats Sugar: Jams and jellies Causes plasmolysis and prevents growth. ⸻ Cold and Drying Cold: Slows microbial metabolism but rarely kills microbes. Drying (desiccation): Removes water necessary for microbial metabolism. Example: Freeze drying (lyophilization). ⸻ CHEMICAL METHODS ⸻ Characteristics of Good Chemical Antimicrobials • Rapid action • Effective at low concentrations • Broad spectrum • Stable • Non-toxic to tissues • Affordable • Effective in presence of organic matter ⸻ Major Chemical Agents ⸻ Halogens Examples: • Chlorine • Iodine Common example: Household bleach (sodium hypochlorite) Mechanism: Oxidizes cellular molecules and damages enzymes. ⸻ Phenols Mechanism: Disrupt cell membranes and denature proteins. Examples: Phenolic disinfectants. ⸻ Alcohols Examples: • Ethanol • Isopropanol Mechanism: Denature proteins and disrupt membranes. Common use: Hand sanitizers. ⸻ Quats Quaternary ammonium compounds. Mechanism: Disrupt membranes. Example: Lysol wipes ⸻ Peroxides Example: Hydrogen peroxide. Mechanism: Forms reactive oxygen molecules that damage cells. ⸻ Detergents / Surfactants Mechanism: Break down lipid membranes. Examples: Soap and cleaning detergents. ⸻ CHAPTER 12 — ANTIBIOTICS ⸻ Alexander Fleming Discovered penicillin in 1928 from the fungus Penicillium. ⸻ Characteristics of a Good Antimicrobial Drug • Selective toxicity • High therapeutic index • Targets unique microbial structures • Effective against pathogen • Minimal harm to microbiota ⸻ Selective Toxicity Ability of a drug to kill microbes without harming host cells. Example: Penicillin targets bacterial cell walls, which human cells lack. ⸻ Susceptibility Tests ⸻ Kirby-Bauer Disc diffusion test. Antibiotic discs placed on bacterial culture. Zone of inhibition measured. Results: Sensitive Resistant ⸻ MIC Minimum inhibitory concentration. Smallest drug concentration preventing visible growth. ⸻ MBC Minimum bactericidal concentration. Smallest concentration that kills bacteria. ⸻ Therapeutic Index TI = toxic dose / therapeutic dose Example from slides: TI of 10 safer than TI of 1.1. ⸻ Antibiotic Mechanisms ⸻ Cell Wall Inhibitors Example: Penicillin Mechanism: Prevents cross-linking of NAM-NAG peptidoglycan. Cell bursts due to osmotic pressure. Other examples: • Methicillin • Cephalosporins ⸻ Cell Membrane Disruption Examples: • Polymyxin • Daptomycin • Colistin Mechanism: Creates pores causing leakage. ⸻ Protein Synthesis Inhibitors Example: Tetracycline Mechanism: Blocks 30S ribosomal subunit. Other examples: • Erythromycin • Azithromycin • Chloramphenicol ⸻ DNA / RNA Inhibitors Example: Fluoroquinolones Examples: • Ciprofloxacin • Levofloxacin Mechanism: Inhibit DNA gyrase. ⸻ Metabolic Pathway Inhibitors Example: Sulfa drugs Block folic acid synthesis. Example drug: Bactrim. ⸻ Drugs for Eukaryotic Pathogens ⸻ Antifungals Examples: • Fluconazole • Amphotericin B • Azoles Target ergosterol in fungal membranes. ⸻ Antiprotozoal Drugs Examples: • Metronidazole • Chloroquine ⸻ Antihelminthic Drugs Examples: • Pyrantel • Mebendazole • Ivermectin ⸻ Antiviral Drugs Targets: • Viral attachment • Viral transcription/translation • Viral assembly or release Examples: Acyclovir Blocks viral DNA replication. Tamiflu Prevents influenza virus release. ⸻ HIV Drugs Target steps in HIV replication: 1 Reverse transcriptase 2 Integrase 3 Protease 4 Viral attachment Combination therapy prevents resistance. ⸻ Antibiotic Resistance ⸻ How Resistance Develops • Mutation • Natural selection • Overuse of antibiotics ⸻ Mechanisms of Resistance • Drug-destroying enzymes • Efflux pumps • Target modification • Reduced permeability ⸻ CHAPTER 13 — MICROBIOTA ⸻ Normal Microbiota Microorganisms living on body surfaces without causing disease. Examples from slides: Skin: Staphylococcus epidermidis Gut: Escherichia coli Breast milk microbes: • Bifidobacterium • Lactobacillus • Streptococcus • Clostridium ⸻ Benefits of Microbiota • Produce vitamins • Digest food • Stimulate immune system • Produce neurotransmitters • Prevent pathogen colonization ⸻ Dysbiosis Imbalance in microbiota. Associated diseases: • Diabetes • Obesity • Cancer • Asthma • Allergies • Heart disease ⸻ Microbiota Development Microbiota develop: 1 During birth 2 Through breast milk 3 Environmental exposure Stable microbiome forms by age 3. ⸻ Probiotics vs Prebiotics Probiotics: Live microbes that improve microbiota. Example: Yogurt. ⸻ Prebiotics: Food that feeds beneficial microbes. Examples: • Garlic • Onions • Asparagus • Agave • Artichokes ⸻ Fecal Microbiota Transplant Transfer of microbiota from healthy donor. Used for: Clostridioides difficile infections Success rate: 70–90%. ⸻ Virulence Factors Examples: Adhesion structures: Capsules, fimbriae Exoenzymes: Hyaluronidase Coagulase Biofilms increase resistance. ⸻ Toxins ⸻ Exotoxins Secreted protein toxins. Examples: • Cytotoxins • Neurotoxins • Enterotoxins ⸻ Endotoxins Found in gram-negative bacteria. Example: LPS containing lipid A. Effects: • Fever • Inflammation • Shock ⸻ CHAPTER 14 — EPIDEMIOLOGY ⸻ Epidemiology Study of disease frequency, distribution, and control in populations. ⸻ Epidemiological Terms Index case: First identified patient. Incidence: Number of new cases. Prevalence: Total existing cases. Mortality rate: Deaths in a population. Case fatality rate: Deaths among infected individuals. ⸻ Disease Occurrence Sporadic: Random cases. Endemic: Constant presence. Outbreak: Localized increase. Epidemic: Large regional increase. Pandemic: Worldwide epidemic. ⸻ Healthcare-Associated Infections (HAIs) Common examples: • CAUTI Catheter-associated urinary tract infection • CLABSI Central line bloodstream infection • Surgical site infections • Ventilator associated infections ⸻ Causes of HAIs • Low patient immunity • Antibiotic resistant organisms • Invasive procedures • Healthcare worker transmission Example: Healthcare workers moving between patients. ⸻ Prevention of HAIs • Medical asepsis • Surgical asepsis • Universal precautions • Infection control officers Examples: • Needlestick precautions • Surface decontamination • Barrier protection ⸻ If you want, I can also give you the 20–30 questions your professor is MOST likely to put on the exam from these slides. Micro professors tend to repeat the same exact conceptual questions every semester, and your slides have some really obvious ones.