Antimicrobial Drugs and Body Systems Practice Flashcards

Flashcards covering antimicrobial drugs, the nervous system, respiratory system, and digestive system based on Chapter 20, 22, 24, and 25 notes.

Antimicrobial drugs

Drugs that kill or inhibit pathogens with minimal harm to the host.

Chemotherapy

The use of chemicals to treat a disease.

Superinfection

The overgrowth of resistant microbes when normal microbiota are damaged.

Paul Ehrlich

The individual credited with the concept of chemotherapy.

Penicillin

The first antibiotic, discovered by Fleming in 1928.

Streptomyces

The genus from which most antibiotics are derived.

Narrow-spectrum

Antimicrobials that affect only a few organisms, such as gram-positive bacteria.

Broad-spectrum

Antimicrobials that affect many organisms.

Eukaryotic pathogens

Fungi, protozoa, and helminths, which are harder to treat because they consist of eukaryotic cells.

Cell wall inhibition

A mechanism of action where drugs like penicillins and cephalosporins block cell wall synthesis, leading to cell death.

Protein synthesis inhibition

A mechanism of action that targets the $70S$ ribosome; examples include tetracyclines and chloramphenicol.

Membrane Damage

A mechanism of action where drugs like Polymyxin B disrupt the cell membrane, causing leakage.

Rifampin

An antimicrobial drug that inhibits RNA synthesis.

Quinolones

An antimicrobial drug that inhibits DNA replication.

Metabolic inhibition

A mechanism of action where drugs like sulfonamides block folic acid synthesis.

Kirby-Bauer test

A disk-diffusion method used for testing the effectiveness of antimicrobial drugs.

MIC

Minimum Inhibitory Concentration; the lowest concentration of a drug that prevents visible growth.

MBC

Minimum Bactericidal Concentration; the lowest concentration of an antimicrobial drug that kills bacteria.

CNS

The Central Nervous System, consisting of the brain and spinal cord.

Meninges

The protective membranes of the CNS: dura mater, arachnoid mater, and pia mater.

Cerebrospinal fluid

Fluid found inside the subarachnoid space.

Blood brain barrier

A structure that prevents many substances, including many antibiotics, from entering the brain.

Meningitis

Infection of the meninges.

Encephalitis

Infection of the brain.

Haemophilus influenzae

A major cause of bacterial meningitis, normally found in the throat; Type b (Hib) commonly affects children under $4$ years old.

Neisseria meningitidis

The cause of meningococcal meningitis, spread through respiratory droplets or direct contact, and enters the bloodstream to reach the meninges.

Streptococcus pneumoniae

A major cause of bacterial meningitis in young children, found in the nasopharynx. Can be fatal if left untreated.

Listeria monocytogenes

A bacterium spread through contaminated food that affects newborns, pregnant individuals, immunocompromised people, and cancer patients; it can cross the placenta and cause miscarriage or still birth.

Tetanus

A disease caused by an exotoxin produced by Clostridium tetani.

Tetanospasmin

The neurotoxin produced by Clostridium tetani that causes muscle spasms, lockjaw, and severe respiratory muscle spasms that can lead to death.

Lockjaw

Jaw muscle contraction caused by the tetanus toxin.

Botulism

A disease caused by an exotoxin produced by Clostridium botulinum, often from contaminated foods.

Botulism symptoms

Includes blurred vision (early sign, 1-2 days) and flaccid paralysis. Can lead to respiratory and cardiac failure, thus leading to death.

Flaccid paralysis

Limp paralysis caused by the botulism neurotoxin blocking nerve impulses.

Toxin Type A

The most virulent form of botulism toxin.

Anaerobic environment

A condition with no oxygen; Clostridium botulinum grows best in these environments, including non-acidic foods such as improperly canned foods.

Botulism Toxin Deactivation

The toxin is heat-sensitive and destroyed by boiling at $100^{\circ}\text{C}$ for $5$ minutes. Proper food canning kills spores, and nitrates/nitrites inhibit bacterial growth.

Leprosy

A chronic bacterial disease caused by Mycobacterium leprae or M. lepromatosis that affects skin and nerves, causing loss of sensation and tissue damage. It spreads slowly and is only mildly contagious but can lead to serious complications if untreated.

Poliomyelitis

A viral infection of the nervous system caused by the poliovirus. Usually mild but can occasionally cause paralysis, and is preventable with vaccines.

Fecal-oral route

The transmission method for poliovirus, involving ingestion of water contaminated with feces.

Viral Disease Progression

The virus first infects lymph nodes (neck) and small intestines, then can spread through the blood, and may reach the spinal cord leading to paralysis.

Viremia

The spread of a virus through the blood.

Salk (IPV)

An injected, inactivated virus vaccine for polio.

Sabin (OPV)

An oral, live attenuated virus vaccine for polio.

Rabies

An acute, usually fatal infection of the brain (encephalitis) that attacks the nervous system, caused by the lyssavirus.

Rabies transmission

Spread through bites from infected animals or virus entry through breaks in the skin.

Rabies progression

The virus enters through a bite, multiplies in muscle tissue, travels along the peripheral nerves to the central nervous system, and causes brain infection (encephalitis).

Rabies symptoms

Includes spasms of mouth and throat muscles, progressive brain and spinal cord damage, and usually ends in death if left untreated.

Rabies post-exposure treatment

Involves administration of a series of rabies vaccine injections and rabies immune globulin to prevent the onset of disease after exposure.

Rabies immune globulin (RIG)

A component of post-exposure treatment for rabies. It provides immediate passive immunity by supplying antibodies that neutralize the virus, used alongside the rabies vaccine.

Arboviral encephalitis

Encephalitis caused by arboviruses, which is a mosquito-borne viral infection of the brain that can become severe. Controlling mosquitoes is the most effective way to prevent it.

Arboviral encephalitis symptoms

Includes chills, headache, fever, and can even progress to coma.

Zika virus

A mosquito-borne virus that can cause central nervous system birth defects amd infect the fetus if a pregnant person is infected. The infection is usually mild in adults with many people having few or no symptoms.

Microcephaly

A condition involving an abnormally small head due to improper brain development, caused by Zika virus in fetuses.

Prions

Abnormal infectious proteins that lack nucleic acids (no DNA or RNA). Can cause fatal brain diseases that damage the nervous system over time.

Creutzfeldt-Jakob disease (CJD)

A prion disease that can be inherited or transmitted through contaminated tissues/instruments.

Kuru

A prion disease linked to cannibalism practices.

Variant CJD

A prion disease linked to eating beef infected with mad cow disease.

Upper Respiratory System

Consists of the nose, sinuses, pharynx, larynx, middle ear, and auditory tubes.

Lower Respiratory System

Consists of the trachea, bronchi, bronchioles, and alveoli (lungs).

Pulmonary Ventilation

The process of moving air in and out of the lungs, enabling breathing and gas exchange.

Respiratory Defense Mechanisms

Includes nasal hairs, muscus production, and cilia actions that trap and remove pathogens and particles from the airways.

Ciliary escalator

A defense mechanism that moves trapped particles upward into the digestive tract.

IgA antibodies

Antibodies found in mucus that serve as a defense mechanism in the respiratory system.

Alveolar macrophages

Cells that engulf and destroy microbes in the lungs.

Immune structures

Includes tonsils, adenoids (pharyngeal tonsil), and lymphoid tissue, which all help to fight infections.

Pharyngitis

Infection of the pharynx or throat.

Laryngitis

Infection of the larynx or voice box.

Tonsillitis

Infection of the tonsils.

Sinusitis

Infection of the sinuses.

Epiglottitis

A serious condition involving infection of the epiglottis, sometimes caused by Haemophilus influenzae type b.

Streptococcal Pharyngitis

Strep throat, caused by group A streptococci (GAS) including Streptococcus pyogenes.

Throat culture

Gold standard test for diagnosing bacterial throat infections. Takes up to 24-48 hours.

Rapid antigen detection test (RADT)

A quick diagnostic test for strep throat that can provide results in minutes. Can miss some cases.

Scarlet fever

A condition caused by untreated Streptococcus pyogenes that produces erythrogenic toxin when lysogenized by bacteriophage.

Diphtheria

Caused by exotoxin from Corynebacterium diphtheriae when infected by bacteriophage, characterized by a thick membrane in the throat made of fibrin and dead cells that can block airflow, making breathing difficult. Also inhibits protein synthesis in cells.

Otitis Media

Infection of the middle ear often causing earache.

Pertussis

Also known as whooping cough, caused by the bacterium Bordetella pertussis. Highly contagious and is transmitted through respiratory droplets.

Tuberculosis

A disease caused by Mycobacterium tuberculosis, which is a slow-growing bacterium. Bacteria are engulfed by alveolar macrophages in the lungs, and if not destroyed, they multiply inside macrophages.

Tubercles

Lesions in lung tissue formed during tuberculosis infection.

Pneumococcal pneumonia

Pneumonia caused by an encapsulated form of Streptococcus pneumoniae; most common cause. It leads to severe inflammation and consolidation in the lungs, often requiring antibiotic treatment.

Haemophilus influenza

A type of bacteria that can cause respiratory tract infections, including pneumonia, and is particularly known for having a higher risk in children ages <5 and adults >65.

Walking pneumonia

Mycoplasmal pneumonia caused by Mycoplasma pneumoniae. Often mild and occurs in crowded environments.

Legionnaires’ disease

A form of pneumonia caused by Legionella pneumophila. It is often associated with outbreaks linked to contaminated water sources, such as hot tubs and cooling towers.

COVID-19

A disease caused by the Betacoronavirus SARS-CoV-2, declared a pandemic in March 2020. Resulted in 667 million infections and 7 million deaths worldwide.

Spike (S) proteins

Proteins used by SARS-CoV-2 for cell attachment.

Antigenic drift

Minor antigenic changes or mutations to HA and NA spikes in viruses like influenza and SARS-CoV-2, resulting in different variants.

Influenza symptoms

Includes chills, fever, headache, muscle ache, and no intestinal symptoms.

Hemagglutinin (HA) spikes

Spikes on the influenza virus used to recognize and attach to host cells.

Neuraminidase (NA) spikes

Spikes on the influenza virus used to help the virus separate from the infected cell.

Antigenic shift

Involves reassortment of the $8$ RNA segments of the influenza virus, leading to pandemics.

Infections in digestive system

Usually caused by ingesting microbes or toxins in food or water. Spreads via the fecal-oral route.

Digestive tract

Mouth → pharynx → esophagus → stomach → small intestine → large intestine

GALT

Gut-associated lymphoid tissue; an immune defense in the digestive system.

Dental Caries

Tooth decay caused by Streptococcus mutans using sucrose to form dextran. Begins with enamel/dentin breakdown.

Tooth decay process

A sticky substance (plaque) formed from sucrose by Streptococcus mutans. Bacteria then attach to teeth, leading to fermentation, which results in acid production. The acid produced then destroys the enamel, leading to decay.

Digestive Infection

Occurs when bacteria grow in the intestines, often resulting in fever.

Digestive Intoxication

Occurs from ingesting toxins, characterized by rapid onset and no fever.

Shigellosis

Also known as bacillary dysentery, caused by Shigella spp. Characterized by diarrhea, often containing blood and mucus, and can lead to severe dehydration.

Salmonellosis

Caused by Salmonella enterica, with an onset of $12$ to $36$ hours. Causes symptoms such as nausea, diarrhea, and abdominal pain.