Quiz 2 Study Guide PDF

Introduction Slide Set II part B and C Portal of Entry 1. Mucous Membrane a. Respiratory tract and pathogen entry via aerosolized droplets i. Bacteria: pneumonia, tuberculosis, pertussis, diphtheria, etc. ii. Virus: influenza, measles, SARS CoV-2, chicken po...

Introduction Slide Set II part B and C Portal of Entry 1. Mucous Membrane a. Respiratory tract and pathogen entry via aerosolized droplets i. Bacteria: pneumonia, tuberculosis, pertussis, diphtheria, etc. ii. Virus: influenza, measles, SARS CoV-2, chicken pox, etc. Chicken pox: a. doesn’t infect chickens b. belong to herpes family c. aerosol-transmitted: herpes family d. contagious e. causes 2 different diseases in same individual i. Early: chicken pox=varicella (slips to dormancy-latency) ii. Later: shingles(reactivated)=zoster Measles virus and COVID-19: contagious due to it being able to spread easily in population b. Urogenital system i. gain entry via intact mucous membrane Ex: syphilis- drills through like cork screw gonorrhea- hitch rides on sperm cells ii. enter via damaged membrane Ex: Chlamydia (bacteria), herpes simplex virus (HSV-I/II), HIV and HPV (Human Papillomavirus) c. Gastrointestinal system mucous membrane i. Enveloped virus: does not enter via complete digestive system because once the lipid envelope is destroyed, the virus loses its infectivity ii. Presence/absence of envelope in viruses: - Enveloped virus: - Environmentally fragile - Need person to person transmission Ex: HIV, herpes virus- exploits proximal and distal end of digestive system - Non-enveloped virus - Environmentally fragile - Oral fecal transmission Ex: rofa virus, polio, hepatitis A, and Norovirus iii. Role of bile salts (sodium deoxycholate): inactivates enveloped viruses 2. Eyes and Conjunctiva a. Appealing/ideal portal of entry  i.short, direct pathway to the CNS (brain- sanctuary/privilege area with few defense cells) ii. Moist, non keratinised, thin mucosal cells iii. retinal blood vessels are superficial and open/naked (no overlying connective tissues) serves as an “on ramp” for pathogen to enter circulatory system and get globally distributed b. Common cold i. enter via conjunctiva ii. Chemical barrier component of eyes: lysozyme (in tears) targets bacterial cell wall (peptidoglycan) and lyses cell part of chemical barrier of defense system 3. Placenta a. Pathogen that can cross placental barrier i. T- Toxoplasma gondii ii. O- Others such as syphilis, gonorrhea, Chlamydia iii. R- Rubella virus iv. C- Cytomegalovirus v. H- Herpes simplex and other herpes family of viruses (Ex: HSV I/II) b. Complication and consequences i. deafness (CMV infection) ii. abortion (Toxoplasma gondii) iii. mental retardation (Toxoplasma gondii) iv. premature births (Toxoplasma gondii) v. birth defects, etc. (Zika virus, Rubella virus) Parenteral route a. voluntary b. puncture, injection (IV drug users), bites, dryness and cracked skin area (due to malnutrition, etc.) c. not a true entry portal Ex: Tetanus, gangrene, HIV, Hepatitis C and B virus, and HPV 4. - Define /Identify a. Disease: disturbance/impairment in the state of health wherein, the body (or its parts) is restricted to perform its normal activity Ex: atherosclerosis, measles, cystic fibrosis b. Sequelae: after-effects of disease following recovery Ex: post polio paralysis, SSPE (subacute sclerosing panencephalitis) following measles infection, strep throat infection sequelae c. Infection: invasion and colonization in the body by pathogenic microbes  Ex: HIV d. Syndrome: variation of disease; group of sign and symptoms associated with a common pathology Ex: Down syndrome, Guillain Barre syndrome, AIDS (Acquired Immune Deficiency syndrome) - Atherosclerosis, cystic fibrosis, and measles are human diseases that are caused by different agents. - Sequelae to strep throat infection (S.pyogenes) - rheumatic fever - glomerulonephritis - Antibodies made against strep throat bacteria reacts with heart valve antigens and caused weakening of heart valves in long run - 2nd complication: Acute glomerulonephritis sets in later following complete elimination of bacteria from body due to the Ag-Ab (antigen-antibody) complex gets deposited in the glomerulus of nephrons (filtration units of kidney) 5. An infection can be present without apparent disease. An infection can be transient (present for only a short amount of time); the body's defense cells recognize and kill/eliminate the pathogen before it comes noticeable. Ex: Individual may be HIV infected but may be symptomless for AIDS Not all microbes cause disease in infected individuals, most are harmless or beneficial to human health. 6. Guillain Barre Syndrome Rare but potentially serious neurological condition body's defense system attacks nerve cells; initiated about 2 weeks following vaccination (J&J) Muscle action are synchronized with nerve cell action; eventually muscle weakness and paralysis sets in condition is usually reversible but recovery can also persists in some instances Symptoms: ○ weakness and tingling in arms and legs ○ double vision ○ difficulty walking, chewing and swallowing ○ difficulty controlling bladder and bowel ○ often diarrhea or respiratory illness for several weeks before developing GBS No cure but therapy (plasma exchange therapy) available 7. Congenital Immune Deficiency (Primary Immune Deficiency): outcome of genetic defect or due to developmental (absence of thymus) abnormality and inherited (associated with a defect in adaptive immune system) a. SCID: Severe Combined Immune Deficiency (absence of B/T cells) b. Defect in thymus development: no T cells circulation (T cells matures in thymus) c. B cell deficiency: leads to Ab's deficiency (antibodies are secreted from differentiated B cells called as plasma cells) Acquired Immune Deficiency (Secondary Immune Deficiency): outcome and interaction of environmental rather than genetic factors such as aging, emotional or physical stress, malnutrition and environmental toxins, certain drugs or radiation treatments, malignancy, and infectious agents (Ex: HIV, measles, TB, leprosy cause immune suppression) - measles virus: targets both B/T cells and make individual immunocompromised HIV + AIDS i. Affected organ systems: 1. respiratory system 2. integumentary system- repeat reactivation of cold sores outbreaks as well as shingles 3. digestive system- chronic diarrhea 4. nervous system- neurological dysfunction are associated with HIV Ex: dementia, cognitive changes, incoordination 5. immune system 6. eyes- blindness in terminal stages of AIDS due to CMV associated retinitis Consequences of immune deficiency: increases susceptibility to cancer and infections (opportunistic infection) compromised immunotherapy such as vaccination 8. Pathogen (aka etiologic agent): a parasite and causative agent of disease in its host. Ex: HIV is an etiological agent for AIDS. SARS CoV-2 is an etiological agent for COVID-19. 2 types of pathogen: Primary pathogen ○ disease causing microbes that is evolve to overcome health host defense ○ endowed with virulence factors Ex: Helicobacter pylori, tuberculosis and Mycobacterium sps., Salmonella sps., cholera pathogen Helicobacter pylori (H.pylori) ○ survives the natural acidic barrier ○ able to cross thick mucosal lining of stomach  ○ causes ulcers and several virulence factors are associated ○ secretes bicarbonate ions: allows to stay in hostile stomach environment ○ secretes urease: NH3 is a strongly basic compound and neutralizes the acidic microenvironment surrounding the bacterial cell ○ lophotrichous arrangement of flagella provides thrust in forward direction to cross the thick mucosal barrier of stomach wall and target epithelial cells (of stomach lining) Tuberculosis (Mycobacterium tuberculosis) ○ pathogen targets alveolar macrophages ○ evolved with a cell wall containing mycolic acid that prevents killing inside macrophages and induces chronic inflammation in lungs (tubercles) ○ Cord factor as a virulence factor Cord factor: glycolipid molecule found in the cell wall of Mycobacterium tuberculosis. Opportunistic pathogen ○ cause disease when body's innate or adaptive defenses are compromised ○ take advantage of weakened immune system ○ wait for a wound/open lesion in epithelial barrier ○ could be part of normal microflora Ex: E.coli, Pneumocystis jerovicci, yeast infection (thrush), CMV (associated retinitis in AIDS patients) ○ often observed amongst elderly and young individuals undergoing chemotherapy or radiation treatment cancer patients (immunocompromised due to immune system getting into “overdrive” mode to kill/eliminate cancer cells) organ transplants patients (on immunosuppressive drugs to prevent/stop organ rejection) AIDS individuals ○ Colonization: growth of microorganisms on epithelial surface epithelial surface: skin, mucous membrane lining (of respiratory, gastrointestinal or urogenital system) as well as other areas (liver, lungs, kidneys, etc,) pathogenic microbes must survive and multiply despite resistance from host defense mechanism  ○ Infestation: presence of large parasites in/outside of body Ex: head lice, worms, etc. ○ Intoxication: disease due to toxin ingestion or its presence in blood Ex: Clostridium botulinum, Salmonella intoxication Anatomy of Bacterial Cell Ch.3 (Spores) refractile structure; commonly made by Gram-positive bacteria belonging to Bacillus sps. and Clostridium sps. produced in response to unfavorable conditions ○ nutrient deprivation ○ radiation ○ toxic compounds in environment [1 spore ↔️ 1 vegetative cell (bacteria)] single bacteriums makes one spore for survival dormant structures and highly resistant to harsh environments is not used for bacterial multiplication but for germination and sporulation ○ Sporulation (sporogenesis): process of endospore formation within vegetative cell (unfavorable condition) ○ Germination: process by which the spore returns to the vegetative cell (favorable condition) spores contain ○ DNA, RNA ○ ribosomes ○ Dipicolinic acid and Ca ions is essential for resuming metabolisms later spore diameter: ○ smaller ○ same size ○ larger compared to the mother cell spore location: ○ terminal ○ central ○ subterminal depending upon bacteria