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Definition
| 1.) Father of Bacteriology 2.) Germ Theory of Disease 3.) Koch's Postulates (still used today to prove that a microbe causes a disease) 4.) Developed pure culture and microbial id techniques 5.) Identified causative agents of anthrax, tuberculosis, cholera 6.) Successes/techniques led to many others searching for/id-ing the microbial causes of many of leading microbial pathogens 7.) Nobel Prize in Medicine 1905 |
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Definition
| 1.) Father of Microbiology 2.) Characterized microbial fermentation pathways 3.) Disproved spontaneous generation 4.) Used microbiology knowledge to save economy of France and China a.) French wine industry by pasteurization b.) French silk industry by id-ing protozoal pathogen of silk worms 5.) Developed vaccine for anthrax, chicken cholera, swine erysipelas, rabies 6.) Founded Pasteur Institute (still leading research center for microbiology) |
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Definition
| 1.) Invented light microscopy 2.) First to study microorganisms 3.) Never shared techniques 4.) Wrote letters to Royal Society of London describing observations |
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| bacteria characteristics/examples |
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Definition
| prokaryotes; 1 circular chromosome; no introns; little noncoding DNA; no membrane-bound organelles; 70S ribosomes; respiration enzymes in cell membrane; complex cell wall; replication by binary fission; structures include: capsule, cell wall, plasma membrane, pili, flagella, nucleoid, plasmids, ribosomes, inclusion bodies, endospores; streptococcus mutans/pneumoniae, pathogenic E.coli, neisseria gonorheae |
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Definition
| 1.) structure - short chains repeating acidic monosaccharides 2.) function - attachment, protection |
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Definition
| 1.) developed by (mistake) Hans Christian Gram 2.) stains used to distinguish b/w 2 basic types of bacterial cell walls 3.) gram positive = purple = thick 4.) gram negative = pink = thin |
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Definition
| 1.) structure - thick layer peptidoglycan (gram +) and thin layer (gram -) 2.) function - shape, prevents lysis, anchors flagella |
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Definition
| basic components = disaccharides & short chains of peptides |
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Definition
| 1.) thick layer of peptidoglycan 2.) techoic acids weave through peptidoglycan a.) regulate cation flow b.) inhibit autolysin activity (degrades peptidoglycan) i.) prevents osmotic lysis ii.) allows for cell expansion during growth |
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Term
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Definition
| 1.) thin layer peptidoglycan 2.) outer membrane (phospholipid bilayer) a.) porins (allow free diffusion of small metabolites) b.) lipopolysaccharide i.) lipid A = endotoxin ii.) O-oligosaccharide (short chain of sugars; used for identification) |
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Term
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Definition
| 1.) structure - phospholipid bilayer w/ embedded proteins 2.) function - regulates molecule traffic a.) phospholipids (free diffusion of small uncharged molecules; restricts flow of large molecules, ions and hydrophilic molecules - sugars, amino acids, nucleotides, fatty acids, macromolecules) b.) proteins (receptors, enzymes, permeases - highly specific transport of polar molecules across membrane) |
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Definition
| 1.) structure - hollow, hair-like projections of the cell 2.) function - attachment, conjugation (gene exchange b/w closely related bacteria) |
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Definition
| 1.) structure - simple protein filament linked to rotor embedded into cell wall and plasma membrane (not homologous to eukaryotic flagella) 2.) function - motility |
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Definition
| 1.) structure - naked DNA (not bound to packaging proteins), singular circular chromosome, ~5000 genes (~800 essential, others used for adapting to different environments) 2.) function - code for gene products (such as enzymes that control the metabolism/growth of the cell) |
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Definition
| 1.) structure - small (only code for several genes), self-replicating circular DNA, copy number varies from 1/cell to 100s/cell) 2.) function - contain optional genetic info that codes for gene products that enable gene exchange or survival in unusual environments, often carry & exchange antibiotic resistant genes |
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Term
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Definition
| 1.) structure - smallest organelle, 70S, two subunits (50S & 30S), ~50 proteins, 3 rRNAs 2.) function - protein synthesis (in rapidly growing cells - ~20000 ribosomes, use 90% of ATP), site of action of many antibiotics |
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Definition
| 1.) structure - varies on type 2.) function - storage (oils, glycogen, starch, enzymes, phosphates) |
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Definition
| 1.) structure - chromosome surrounded by thick protein 2.) function - survive harsh environmental conditions (resistant to - disinfection, antibiotics, heat, radiation, dying), dormant structure |
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Term
| virus characteristics/examples |
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Definition
| 1.) types a.) host - plants, bacteria, animals b.) structure - ssDNA, dsDNA, ssRNA, dsRNA (nucleic acid); helical, polyhedral, complex (capsid); enveloped, nonenveloped 2.) common pathogenic viruses : upper respiratory system (rhinovirus), lower respiratory (influenza A & B), CNS (rabies virus), reproductive (human papilloma virus), circulatory (hep B virus), digestive (rotavirus), eye (adenovirus), skin (varicella zooster virus) |
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Term
| viral replication steps (basic) |
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Definition
| 1.) attachment 2.) entry 3.) gene expression (mRNA transcription, protein synthesis, nucleic acid replication) 4.)viral assembly 5.) release of new virions (fully functional virus |
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Term
| eukaryotic pathogenic microbes (fungi) characteristics/examples |
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Definition
| 1.) eukaryotic, multinucleate or multicellular, unique cell wall of chitin, growth as thread-like filaments (hyphae), decomposers, asexual repro via spores 2.) cell wall (inside → out) = chitin (polymer mainly of unbranched chains of N-acetyl-glucosamine); ß glucan (most of wall strength is due to fibers of ß glucan that is interwoven b/w other macromolecules); mannoprotein layer (heavily glycosylated mannose-containing glycoproteins) 3.) classification a.) morphology i.)yeast (divide through budding) ii.) filamentous (form hyphae) iii.)diphormic (switch b/w different growth morphologies depending on environment) b.) infection type i.)superficial mycoses (body surfaces - tinea = ringworm, athlete's foot; candida = vaginal/oral yeast infectionss) ii.)deep mycoses (internal tissues and organs - histoplasma capulatum) |
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Term
| eukaryotic pathogenic microbes (protozoa) characteristics/examples |
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Definition
| 1.) microscopic, eukaryotic, nonphotosynthetic, unicellular or multicellular w/ no tissue development, no cell wall 2.) classification - types - a.) flagellates (absorb nutrients, motility by one or several long flagella - trichomonas vaginalis, giardia lamblia) b.) ciliates (ingest food into oral groove, motility by cilia - balantinium) c.) amoebae (ingestion of food by phagocytosis, motility by pseudopodia - entamoebae histolytica) d.) sporozoa (absorption of nutrients, repro by spore formation - plasmodium falciparum) |
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Term
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Definition
| more complex - animal virus, retrovirus (ssRNA as genetic info which is copied into dsDNA), forms provirus (viral DNA is incorporated into the host cell's DNA, "time bomb" immune to antivirals), budding release of new viruses |
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Term
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Definition
| ssRNA genome, icosohedral capsid (polyhedral capsule w/ 20 plates), enveloped |
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Term
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Definition
| 1.) impt structural proteins a.) p24 (capsid protein, major antigen) b.) gp160 (envelope protein, attachment and entry of virion) 2.) impt enzymes a.) reverse transcriptase (RNA → DNA) b.) integrase (viral DNA is incorporated into host cell chromosome) c.) protease (needed for viral assembly, cleaves protein precursor) |
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Term
| env-gag-pol gene HIV genetic structure |
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Definition
| 1.) env a.) envelope protein b.) gp160 i.) gp120 - extrinsic, interacts w/ host-cell receptor ii.) gp41 - membrane protein, required for entry 2.) gag a.) matrix protein (MA; p17) embedded in the lipid bilayer b.) capsid protein (CA, p24) c.) encapsulates the RNA d.) nucleocapsid protein (NC; p 7/6) binds RNA 3.) pol a.) reverse transcriptase b.) protease c.) integrase d.) single-stranded RNA |
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Term
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Definition
| 1.) attachment (CD4 receptors - t4 lymphocytes, neurons, macrophages) 2.) entry a.) membrane fusion (gp41) b.) uncoating (cellular gathways) *3.) reverse transcription (retrovirus only) *4.) integration//stop? - provirus time bomb 5.) gene expression (mRNA transcription, protein synthesis, nucleic acid replication) (DNA → mRNA → proteins) 6.) viral assembly (protease = key target) 7.) release - budding (cellular pathways) |
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Term
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Definition
| cellular proteins sstimulated to produce membrane evagination at site of capsid assembly; membrane contains gp 160; initial virus is immature and not infective (HIV protease completes cleavages to produce functional virion) |
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Term
| eukaryotic microorganisms - basic characteristics |
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Definition
| (macromolecular structure, DNA as genetic info, info flow = DNA → RNA → proteins, ATP as energy source, cell membrane structure and function, glycolysis as an energy-yielding pathway, >1 linear chromosomes, introns common, abundant non-coding DNA, membrane-bound organelles, 80S, respiration enzymes in mitochondrial membrane, simple/no cell wall, replication by mitosis and cytokinesis) |
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Term
| horizontal modes of transmission |
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Definition
| 1.) contact (direct, indirect, droplet) 2.) common vehicle (water borne, food borne, airborne) 3.) vector-borne (mechanical, biological) |
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Term
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Definition
| 1.) direct - physical contact, fluid exchange, parenteral route (break in the integrity of the skin or mucous membranes - shared needles, blood transfusions, injuries) 2.) indirect contact - fomites = nonliving intermediate carries pathogen to new host 3.) droplet - mucous droplets transmit pathogen, travel <1 meter, highly contagious |
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Term
| common vehicle transmission |
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Definition
| 1.) water-borne - oral/fecal route - food/H2O contaminated w/ fecal material a.) common in underdeveloped countries (1/3 of world pop lacks sewage tx, 1/6 of world pop lacks H2O tx) b.) developed countries - common in toddles, failure to wash hands before food preparation 2.) food-borne - pathogen contaminates uncooked or improperly cooked foods 3.) airborne - pathogen resists drying and temperature changes, travels >1 meter, most contagious |
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Term
| vector-borne transmission |
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Definition
| 1.) mechanical - carries pathogen in/on body (flies, shellfish) 2.) biological - pathogen lives and replicated in arthropod (blood-sucking arthropods = ticks, mosquitos) |
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Term
| indirect damage by microbe |
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Definition
| 1.) enzymes (hemolysin, leukocidin, hyaluronidase and collagenase, DNAse - break down blood clots-, streptokinase, coagulase, phospholipase; common enzyme-damaging pathogens = staphylococcus and streptococcus 2.) endotoxins - one kind, Lipid A of outer membrane, always the same effect → gram negative cell is phagocytized by leukocyte, degraded by lysosome, release of Lipid A which stimulates production/release of interleukin-1 (resets thermostat in hypothalamus to higher temp = fever) and tumor necrosis factor (TNF, multiple pathways can damage capillaries, causes fluid loss and disseminated coagulation); can be lethal - shock (massive fluid loss resulting in heart failure), disseminated intravascular coagulation (DIC, multiple organ failure from damage to multiple capillary beds from clotting), acute respiratory distress syndrome (ARDS, fluid loss in lungs blocks gas exchange) 3.) exotoxins - >200 diff kinds, proteins, different effects depending on toxin; two subunits (receptor binds to specific cell type, toxin changes physiology of cell); general types - neurotoxins, enterotoxins, cytotoxins |
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Term
| endotoxin causes DIC and fever |
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Definition
| disseminated intravascular coagulation; multiple organ failure from damage to multiple capillary beds from clotting; interleukin-1 = resets thermostat in hypothalamus to higher temperature - fever; tumor necrosis factor = multiple pathways can damage capillaries, causes fluid loss and disseminated coagulation |
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Term
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Definition
| neurotoxins, enterotoxins, cytotoxins |
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Term
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Definition
| botulism toxin; inhibits release of acetylcholine from motor end plates, no muscle fiber depolarization, flaccid paralysis (death from inability to inhale) |
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Term
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Definition
| cholera toxin; binds to large intesting epithelium, activates adenylate cyclase which synthesized cyclic AMP (cAMP), cAMP alters membrane permeability to reverse osmolarity gradient, water is drawn out of the intestinal epithelium (death from rapid dehydration) |
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Term
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Definition
| diphtheria toxin; receptor targets pharynx and heart, toxin binds to elongation factor and inhibits protein synthesis (death from necrotic tissure in pharynx dislodging and blocking glottal opening, or death from heart failure) |
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Term
| mechanisms used to avoid host defenses |
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Definition
| concealment of antigens, antigenic variation, immunosuppression |
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Term
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Definition
| 1.) antigen - an antibody generating substance, normally a protein or carbohydrate on the outside of the microbe (spike proteins on the outside of Influenza A envelope) 2.) intracellular pathogens - avoid circulating antibodies and cytotoxic T cells - all viruses (HIV in macrophages, HSV in neurons); intracellular bacteria (obligate - required - chlamydia, rickettsia, mycoplasma; facultative - mycobacterium, yersinia; protozoa - sporozoans - plasmodium) 3.) requirements for survival of intracellular bacteria/protozoa a.) survive phagolysosome degradation by inhibiting phagolysosome formation (mycobacterium tuberculosis) b.) escape degradation by destroying phagolysosome membrane (listeria monocytogenes) c.)induce phagocytosis by non-leukocytes (salmonella, shigella, plasmodium) 4.) privileged site - those locations that do not normally contain circulating antibodies/cytotoxic T cells (epithelial layers - influenza virus, bordetella pertusis), CSF (meningitis-causing bacteria), synovial joints and testes 5.) uptake of host molecules - coating the pathogen w/ host molecules to prevent detection by immune defenses (schistosoma - finds plasma proteins to membrane; staphylococcus aureus - protein A binds constant region of antibodies) |
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Term
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Definition
| 1.) change in protein structure of primary antigens used by immune system to destroy pathogen 2.) mutation - change in genetic info to the extent that key antigens are no longer recognized by immune system a.) HIV (1000000x more mutation, heterogeneity of virus results in immune system having to respond to many different antigens) b.) influenza A - antigenic drift (slow accumulation of mutations in the key antigens as the virus spreads through the population; allows the virus to reinfect an individual after sufficient antigenic drift has occurred; causes "flu shot" to not be 100% effective) 3.) recombination - exchange of genetic info from 2 different sources - influenza A (antigenic shift, a recombination b/w an animal influenza A virus (swine/bird) and a human influenza A virus, rare, causes pandemics) 4.) programmed gene switching - a programmed rearrangement of genetic info to alter the key antigens that the immune system is targeting (trypanosoma - 10% of genome involved in switching coat proteins to prevent destruction by immune response) 5.) immunosuppression - destruction of inhibition of components of the immune system which enable the microbial pathogen to survive until it spreads to a new host a.) inhibition of humoral and cell-mediated immune systems (HIV - destroys T4 lymphocytes) b.) destruction of T cells (measles virus) c.) destruction of B cells (EB virus - mononucleosis) d.) destruction of antibodies (IgA protease produced by meningitis-causing bacteria e.) inhibition of phagocyte functions |
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Term
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Definition
| where a pathogen survives and multiplies until it can enter a new host - human, animal, environment (soil, water) |
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Term
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Definition
| infected humans serve as nutrient source for survival and multiplication of pathogen (asymptomatic - no signs of disease; symptomatic - shows disease signs); humans only = pertussis, measles, gonorrhea, common cold, AIDS; either very sensitive to environmental changes or will only attach to human tissues |
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Term
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Definition
| primary site of survial and multiplication is in animals = zoonoses; rabies, HPS, lyme disease; all can attach to both human and animal tissues |
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Term
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Definition
| 1.) soil - tetanus (clostridiu, tetani), diarrhea (bacillus cereus) 2.) water - cholera (vibrio cholerae), typhoid fever (salmonella typhi) 3.) all are versatile pathogens that can survive and replicate under a variety of conditions |
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Term
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Definition
| 1.) the microorganism must be found in all organisms suffering from the disease, but not in healthy organisms 2.) must be isolated from a diseased organism and grown in pure culture 3.) cultured microorganism should cause disease when introduced to a healthy organism 4.) microorganism must be reisolated from the inoculated, diseased experimental host and identified as being identical to the original specific causative agent |
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Term
| chancroid (haemophilus ducreyi) |
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Definition
| 1.) etiology - gram negative bacterial pathogen, streptobacillus, irregularly rod-shaped (short rods or chains) w/ "school of fish" appearance 2.) transmission a.) reservior - infected humans b.) mode of transmission - transmitted via direct sexual contact (genital, anal, oral) 3.) pathogenesis a.) entry - spread into the repro tract or external genitalia after direct contact w/ another lesion, enters epithelial tissue breaks through small skin abrasions w/ another lesion b.) attachment - attaches to and attacks neutrophiles and macrophages upon entry into the torn epithelial cells c.) avoiding defenses - avoid defenses by restricting to epithelial surface, farther from defenses d.) damage - produces the cytotoxin HdCDT, which causes local tissue destruction and death of epithelial and myeloid cells, keratinocytes, and primary fibroblasts; HdCDT also produces an inflammatory response w/ swelling and pus formation; cell proliferation is prevented, allowing the formation of ulcers e.) exit - exits in pus from infectious lesion during abrasion (intercourse) 4.) clinical features a.) symptoms appear 4-10 days after initial contact b.) common symptoms - first initial is small papule (small inflamed bump, no pus); one or more sores/raised bumps arise on genital organs (surrounded by narrow red border filled w/ pus); ulcers enlarge and develop ragged borders, surrounded by rim or erythema; lesion ruptures resulting in painful open sore; lymph glands can become infected if untreated (results in severe pain, enlargement, ulceration of nodes); as many as 50% of pts have "bubo" - inflamed tender swelling; painful urination/bowel movements/intercourse, rectal bleeding, vaginal discharge c.) most common among men, especially uncircumsized; foreskin most common location, less likely = shaft, glans, meatus d.) females - most common at labia majora (less likely = labia minora, thighs, perineum, cervix); sometimes carried by women w/ no symptoms showing 5.) diagnosis a.) visual id of 1 or more painful genital ulcers (swab test of fluid/pus from ulcer b.) negative test result for herpes simplex virus c.) no evidence of treponema pallidum infection (cause of syphillis) by blood test or darkfield examination (light is indirectly passed through a microscope, spiral shaped objects appear - less common b/c docs often lack equipment) d.) possible presence of regional lumphadenopathy (chronic enlargement of lymph nodes) - comno of painful ulcers and tender inguinal adenopathy occur in 1/3 of pts e.) microscopic detection of gram negative rods in short chains 6.) treatment a.) cleanse and soak infected ulcers b.) meds used i.) azithromycin 1 g orally single dose ii.) ceftriaxone 250 mg intramuscularly single dose iii.) ciprofloxacin 500 mg 3 times a day for 3 days iv.) erythromycin base 500 mg 3 times a day for 7 days c.) HIV infected and uncircumsized males do not always respond as well to those meds - large lymph nodes then need to be drained w/ needle or local surgery 7.) prevention - abstinence, monogamy, consistent/correct condom use, limiting number of sexual partners, no sex w/ the infected, education, preventative antibiotic tx for those at high risk |
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Term
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Definition
| 1.) etiology - gram negative, coccobacilli, intracellular pathogen 2.) transmission a.) reservior - many animals including cattle, sheep, goats, swine, dogs; zoonotic infection b.) transmission - animals to humans through direct contact of infected animals; ingestion of infected animal products, most commonly raw milk/dairy products; inhalation of infected airborne agents such as decaying vegetation; infection can occur through abrasion of the skin when handling infected animals 3.) pathogenesis a.) entry - bacteria enters body through breaks in skin, mucous membranes, conjunctiva in eye, resp tracts, GI tracts b.) attachment - engulfed by polymorphonuclear leukocyts and macrophages c.) avoiding defenses - not destroyed by phagocytes, prevents fusion of the phagosome and lysosome, resisting being digested and destroyed d.) damage - transported to lymphatic system and replicate there locally; may also replicate in liver, kidney, spleen, breast tissue, joints; causes both localized and systemic infections; extracellular replication of granulomes may occur along w/ bacteria, especially in liver and spleen; causes an inflammatory reaction, central necrosis (cell death), lesions (abrasions) and abscesses (collection of pus) that can occur in many diff organs; infections can lead to fatal septicemia (presence of bacteria in the blood) e.) exit - typically exits through infected tissue 4.) clinical features a.) common signs and symptoms - flu-like; fever, headache, sweating, back pain, fatigue, weakness; once present, symptoms quickly get worse; long term = fevers occurring often, pain in joints, consistently tired, infect CNS and lining of the heart, usually recovery takes a few wks/mths (chronic stage up to 1 yr) 5.) diagnosis - lab tests done on blood or bone marrow, may also use lymph nodes or urine; ELISA (enzyme-linked immonsorbent assays) can be used to measure antibodies used to fight off the bacteria; two tests must be taken 2 wks apart; IgM antibodies present in acute brucellosis while IgG and IgA antibodies present in chronic 6.) combination of antibiotics: doxycycline 100 mg taken orally twice daily along w/ rifampin 600 mg orally once daily for 3 wks; or doxycycline alone if exposed to abortus (resistant to rifampin) 7.) prevention - destroyed in milk/dairy by pasteurization; when working in areas of possible contamination wear protective clothing/goggles; no vaccine for humans |
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Term
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Definition
| 1.) etiology - chlamydia trachomatis bacterium; gram-negative (thin-walled), rod-shaped, lives intracellularly 2.) transmission a.) reservior - humans, mostly homosexual men b.)transmission - direct contact w/ lesions/ulcers/other affected area where bacteria located, skin to skin contact w/ infected, sexual contact w/ infected 3.) pathogenesis a.) entry - enters through small abrasions in mucosal surface of rectum b.) attachment - attaches to host cells and enters these cells through endocytosis c.) avoiding defenses - avoids immune system antibodies by being an intracellular pathogen d.) damage - direct damage from the bacteria is cell lysis, which triggers an inflammation response from body e.) exit - bacteria exit through pus and fluid from infected ulcer, which carries pathogen to new host cells 4.) clinical features - swelling/redness in groin area, drainage from lymph nodes in groin, blood or pus discharge from rectum, constipatiom, pain while having bowel movements, genital or rectal ulcer or papule, anal spasms 5.) diagnosis - limitations of commercially available tests → collecting serum and rectal swab specimens, having a sigmoidoscopy done to identify any ulcers, testing for presence of chlamydia trachomatis 6.) treatment - antibiotics - doxycycline 100 mg by mouth twice a day 21 days 7.) prevention a.) vaccines - none b.) behavioral - abstain from any sexual contact, stay monogamous, condoms properly, no bare skin on abnormal discharges/ulcers, those at high risk to contract an STD should have a regular sexual health screening c.) other - physicians report cases to PHS, follow up, recommend tx options |
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