Microbiology Key Vocabulary

Key Vocabulary

• Active artificial immunity is a type of immunity.
• Active natural immunity is a type of immunity.
• Anaerobe is a term to classify bacteria.
• Aerobe is a term to classify bacteria.
• Antibodies are produced during the immune response.
• Antigen is anything that causes an immune response.
• Autoimmune relates to conditions with the immune system attacks the body.
• Bactericidal means capable of killing bacteria.
• Bacteriostatic means inhibits the growth of bacteria.
• Benign means not harmful.
• Chemotherapy is a treatment that uses drugs to fight cancer.
• Culture and sensitivity (C&S) tests are used to identify bacteria.
• Host refers to an organism that harbors a parasite or symbiotic organism, typically providing nourishment and shelter.
• Inflammation refers to the body's response to injury or infection.
• Malignant means cancerous.
• Metastasis is the spread of cancer to other sites in the body.
• Nosocomial refers to hospital-acquired infections.
• Passive artificial immunity is a type of immunity.
• Passive natural immunity is a type of immunity.
• Pathogenic means capable of causing disease.
• Superinfection is a secondary infection that occurs during or after treatment of another infection.

The Immune Response

• An antigen invades the body, triggering the immune system.
• The body attacks the antigen to eliminate the threat.
• Inflammation limits the spread of microbes during the immune response.
• The release of bradykinin, complement, histamine and leukotrienes, and prostaglandins marks the first phase of the immune response.
• During the second phase, the body launches an attack by secreting antibodies.
• B cells act as memory cells, recording the attack to guard against future occurrences.
• T cells (CD cells) produce cytokines to further regulate the immune response.

Medications Affecting the Immune System

• Anti-inflammatory medications reduce inflammation
• Anti-infective medications combat infections, killing or preventing the spread of infectious agents.
• Antitoxins counteract toxins by neutralizing their effects.
• Antifungal medications are used to treat fungal infections.
• Antiviral medications target viral infections by inhibiting viral replication.
• Antiparasitic medications are ised to eliminate parasites from the body.
• Vaccines provide immunity against specific diseases by stimulating the immune system.
• Antineoplastic medications, also known as chemotherapy drugs, are used to treat cancer by destroying cancer cells.

Anti-Inflammatory Medications

• These medications are used to stop or reduce the body's inflammatory response.
• They are often prescribed for patients with autoimmune disorders to prevent the immune system from attacking healthy tissues.
• Autoimmune disorders which may require anti-inflammatory drugs include: rheumatoid arthritis, dermatitis, multiple sclerosis, systemic lupus erythematosus.

Immunosuppressants

• Immunosuppressants are used in the long-term therapy of inflammatory diseases to suppress the immune system
• Azathioprine (Imuran, Azasan) and cyclosporine (Neoral, Sandimmune, and Gengraf) are used to treat rheumatoid arthritis.
• Cyclosporine and sirolimus (Rapamune) are used to treat psoriasis.
• Azathioprine (Imuran, Azasan) is prescribed for Crohn's disease.

Anti-Infective Medications

• Anti-infective medications are classified based on their mechanisms of action or chemical structures.
• These medications target processes of pathogenic microorganisms.
• Anti-infectives act on protein synthesis, inhibit DNA or RNA synthesis, or destroy the cell wall of the pathogen.

Antibiotics

• Used to treat bacterial infections.
• Bacteria can be classified by their shape (rods, spheres, spirals), staining (Gram-negative or Gram-positive), and need for oxygen (aerobe or anaerobe).
• Broad-spectrum antibiotics like vancomycin and gentamicin are effective against many types of bacteria.
• Antibiotics can kill healthy bacteria, resulting in super-infection or yeast infections.
• A culture and sensitivity (C&S) test helps identify the bacteria and determine the most effective antibiotic.
• The initial antibiotic prescription may need adjusting based on C&S test results.

Penicillins

• Penicillins are one of the oldest classes of antibiotics, dating back to World War II.
• Penicillins can be administered orally, topically, or by injection for common infections.
• Penicillins kill susceptible gram-positive and gram-negative bacteria by destroying their cell walls.
• Penicillins are the least expensive antibiotics; however, many patients are allergic.
• Examples of penicillins are ampicillin (Omnipen), amoxicillin (Amoxil), and penicillin (Pen VK).

Cephalosporins

• Similar to penicillins but more expensive.
• There are four generations: first includes medications used for people allergic to penicillin, like cefazolin (Ancef, Kefzol) and cefaroxil (Duricef).
• Second generation cephalosporins are used to treat nosocomial pneumonia, pelvic infections, or intra-abdominal infections, like cefprozil (Cefzil) and cefuroxime (Zinacef).
• Third generation cephalosporins treat gram-negative bacteria, such as ceftriaxone (Rocephin).
• Fourth generation is used intravenously for severe nosocomial surgical infections, like cefepime (Maxipime).
• They are also used to prevent infection.
• Use of alcohol can cause abdominal side effects when taking this medication.

Tetracyclines

• Bacteria are becoming increasingly resistant to tetracyclines
• Tetracyclines prevent protein synthesis, interrupting reproduction of bacteria
• Tetracyclines are effective against many gram-negative and gram-positive microbes
• Tetracyclines can cause permanent staining in the teeth of a child or fetus, so are not used in children or pregnant women.
• Examples of tetracyclines include doxycycline (Vibramycin), minocycline (Solodyn), and tetracycline (Sumycin).

Macrolides

• Macrolides inhibit reproduction of microorganisms by inhibiting protein synthesis.
• Some macrolides such as azithromycin (Zithromax) are bactericidal or bacteriostatic.
• Macrolides are used to treat many different infections.
• Examples of macrolides are erythromycin (EES Granules), clarithromycin (Biaxin), and azithromycin (Zithromax).

Aminoglycosides

• Aminoglycosides are a class of antibiotics that have an increased risk of toxicity as compared to other antibiotics.
• Monitoring blood levels is necessary when administering aminoglycosides to avoid toxicity.
• Aminoglycosides are typically used only when other anti-infective options are unsuitable due to their nephrotoxic and ototoxic effects.
• Aminoglycosides are effective against aerobic gram-negative bacteria
• Can be administered topically via ointments, eye drops, or ear drops, or as an IV injection.
• Amikacin (Amikin), gentamicin (Garamycin), and tobramycin (Nebcin) are examples of aminoglycosides.

Quinolone Medications

• Quinolones prevent bacteria from growing, so they are bacteriostatic
• Quinolones are reserved for antibiotic-resistant strains of bacteria due to rare, severe side effects
• Can be administered via Injections, ophthalmic route, or oral route
• Useful for chronic urinary tract infections
• Ciprofloxacin (Cipro), ofloxacin (Floxin) are examples of quinolone medications

Sulfonamides

• One of the earliest classes of antibiotics used.
• Kill bacteria by interrupting their metabolism.
• Primarily used for the treatment of urinary tract infections, collecting in the bladder prior to excretion.
• Many allergies to sulfonamides.
• Trimethoprim-sulfamethoxazole (Septra, Bactrim) and Erythromycin-sulfisoxazole (Pediazole) are examples.

Antituberculosis Agents

• These antibiotics specifically target Mycobacterium tuberculosis, the bacteria responsible for tuberculosis.
• Treatment involves a combination of two to four medications simultaneously, taken daily for up to 1 year.
• Cycloserine (Seromycin) prevents bacteria from growing in the body.
• Rifampin (Rifadin) can both treat and prevent tuberculosis.
• Rifampin (Rifadin) turns body secretions red/brown.

Antitoxins

• Antitoxins are antibodies administered to counteract a toxin in a person at high risk for a disease or condition.
• They are administered when a patient exposed to diphtheria, tetanus, or botulism has adequate immunity.
• Tetanus immune globulin (Baytet) provides immediate neutralization of tetanus toxoid.

Antifungal Medications

• Used to treat Tinea pedis (athlete’s foot) and Candidiasis (yeast infection).
• Topical medications include: Ketoconazole (Extina, Nizoral), Miconazole (Desenex, Micatin), and Nystatin (Mycostatin).
• Systemic medications are typically used for immunocompromised patients.
• Systemic medications include: Fluconazole (Diflucan), Itraconazole (Sporanox), Ketoconazole (Nizoral), and Fungizone (Amphotericin B).
• Fungizone (Amphotericin B) is reserved for life-threatening fungal infections due to serious side effects.

Viruses

• Require a host to reproduce, be it a human, plant, or animal.
• Viruses are small microorganisms
• Insert genetic material material into host.
• Examples include: cytomegalovirus, rabies , smallpox, chickenpox, shingles, influenza, common cold and herpes.

Antiviral Medications

• Inhibit reproduction of a virus.
• Most shorten duration of symptoms but do not prevent illness.
• Valacyclovir (Valtrex) treats viruses that cause herpes, chickenpox, and shingles.
• Zanamivir (Relenza) and oseltamivir (Tamiflu) treat influenza type A and B.

Human Immunodeficiency Virus (HIV)

• HIV attaches to CD4 receptors on T4 (helper) lymphocytes after entering the body.
• The virus uncoats and puts its genetic material into the host T4 cell.
• Genetic material forms DNA that is passed to other T4 lymphocytes via protease (viral enzyme).
• After latent phase, HIV may produce as many as 10 billion virions every day.
• Current guidelines recommend antiretroviral therapy for HIV-infected patients to reduce the risk of disease progression.

Antiretroviral Medications

• Are a group of medications to treat retroviruses, such as HIV.
• Retroviruses imbed genetic material in the gene of healthy cells, making them difficult to fight.
• Medications are classified according to where in the reproduction process they act

Antiretroviral Medication Types

• Nucleoside reverse transcriptase inhibitors (NRTIs)-Lamivudine
• Fusion Inhibitor -Enfuvirtide
• Protease inhibitors (PIs)- Ritonavir
• HIV integrase strand transfer inhibitors-Elvitegravir
• CCR5 coreceptor antagonist-Maraviroc

Antimalarials

• Prevent and treat malaria.
• Inhibit the growth of the malaria parasite in the red blood cells of the body.
• Examples: Atovaquone/proguanil (Malarone), Chloroquine (Aralen), Mefloquine (Lariam), and Primaquine.

Cancer

• Cancer is a a disorderly and uncontrolled division of cells.
• Cancer cells usually divide more rapidly than healthy cells.
• Nicotine and alcohol can trigger this cell division to begin.
• The body cannot identify abnormal cancer cells.
• Metastasis refers to the spread of cancerous cells to surrounding or distant body parts.

Chemotherapy

• A combination of several antineoplastic and cytotoxic medications.
• Treatment can be given intramuscularly, intravenously, subcutaneously or intrathecally (fluid around spine and brain).
• Creams and gels can treat mild forms of skin cancer.
• Each individual receives a combination of medications depending upon their specific cancer.

Adverse Effects of Chemotherapy

• Includes nausea, vomiting, alopecia, and decreased blood counts.
• Chemo is caustic to tissue, and inserting central lines is common.
• Administration can be dangerous, and only those allowed by law may handle/administer.
• Can have toxic effects, including organ damage.

Immunomodulators

• Stimulate immune system in patients with multiple myeloma..
• Examples include Filgristim, Lenalidomide (Revlimid), and Thalidomide (Thalomid).
• Thalidomide (Thalomid) has a high risk of birth defects, therefore, multiple birth control methods are required.