EXAM 3 STUDYGUIDE 04 01 2015 Lecture 17 18 Bacteria Three Domain System Cell Type Cell Wall Archea Prokaryotic Varies in composition no peptidoglycan Bacteria Prokaryotic Eukarya Eukaryotic Contains peptidoglycan Composed of straight carbon chains attached to glycerol by ester linkage Varies in composition Composed of straight carbon chains Composed of branched carob chains Methionine Formylmethionine Methionine No Lacking Present Eukarya Eukaryotic Yes Present Present Bacteria Prokaryotic No Lacking Lacking Archea Prokaryotic Varies in composition no peptidoglycan Composed of branched carob chains Contains peptidoglycan Composed of straight carbon chains attached to glycerol by ester linkage Varies in composition Composed of straight carbon chains Membrane Lipids First Amino Acid in Protein Synthesis Antibiotic Sensitivity rRNA Loop Common arms of tRNA Cell Type Cell Wall Membrane Lipids First Amino Acid in Protein Synthesis Antibiotic Methionine Formylmethionine Methionine Sensitivity No rRNA Loop Common arms of tRNA Lacking Lacking Yes Present Present No Lacking Present THE PROKARYOTES Characteristics of Bacteria Peptidoglycan cell walls Ester linked lipids Mostly phospholipids and Glycerol diesters of fatty Ribosomes 70s unique for bacteria Genome are single circular DNAs Many have plasmids and transpoons acids Genome sizes Largest Myxococcus xanthus 9450 kbp Smallest Mycoplasma genitalium 585 kbp E Coli s genome is 4700 kbp Characteristics of Archea No peptidoglycan Live in extreme conditions Three groups The methanogens Strict anaerobes that produce methane Extreme halophiles require high concentration of salt Hyperthermophiles grow in extremely hot environment Proteobacteria A phylum of bacteria that includes most of the gram negative chemoheterotrophic bacteria FIVE SUBDIVISIONS The Alphaproteobacteria important plant microbes ex Rhizobium Rickettsia Important tool for transgenic plants and inserting plasmids into plant cells The Betaproteobacteria Neisseria Spirillum Bordetella The Gammaproteobacteria Found in coastal water Ex Vibrio Cholerae The Enteric E Coli relatives causes cholera 1 2 The Vibrios relatives 3 The Pseudomonas Opportunistic pathogens metabolically diverse 4 Legionella found in streams and warm water pipes Coxiella intra with polar flagella cellular parasite The Deltaproteobacteria Bdellovibrio Prey on their bacteria Desulfovibrionales Use S instead of O2 as final acceptor The Epsilonproteobacteria Helicobacter ulcers and Campylobacter Diarrhea Gram Positive Bacteria Low G C ratio A The bacillus class o Bacillus aerobic spore formers o The Streptococcus Taxonomically complex many pathogens o The Staphylococcus Aures produce exotoxin o Listeria L monocytogenes contaminate food B The Clostridial class Clostridium The obligate anaerobic Perfringens Botulinum causes botulism Tetani causes Tetanus C The wall less bacteria A Mycoplasma with smallest genomes and some can be cultured Ex Pneumia Spiroplasma sp Acholeplasma High G C ratio The actinobacteria Distinctive properties o Filamentous forms Actinomyces o Many soil bacteria Streptomyces o The acid fast breakfast OTHER BACTERIAL GROUPS 1 Chlamydia obligate intracellular parasites Three important species Trachomatis causes STD Psittaci Life Cycle Elementary Body Reticulate body Given up 2 Spirochaetes Spiral organisms with a sheath axial filament Slow growing aquatic Axial filaments used for motility Several human pathogens Ex Treponema pallidum Syphilis Borrelia burgdoeri Lyme disease MICROBIAL DIVERSITY Bacteria size range Thiomargarita 750um Nanobacteria 0 02um in rocks PCR indicates 10000 bacteria per gram per soil Many bacteria have not been classified yet no culture no nutrients limited media and conditions Lecture 19 Principles of Disease and Epidemiology Pathology is the scientific study of disease but it is concerned with etiology the cause of disease Pathology then focuses on pathogenesis the manner in which a disease develops An infection is the invasion or colonization of the body by pathogenic microorganisms Diseases however occur when an infection results in any change from a state of health A disease is an abnormal state in which the body is not properly adjusted or incapable of performing its normal functions An infection may exist in the absence of detectable disease o Ex A body can be infection with the virus that causes AIDS but still experiences no symptoms of disease Normal Microbiota and the Host Normal Microbiota Transient microbiota are the microorganisms that establish a permanent residence colonize in a member s body but do NOT produce disease under normal conditions for several days weeks or months and then disappear the host Within this relationship at least one organism is dependent on the other is the relationship between the normal microbiota and are the microorganisms that may be present Symbiosis a Commensalism is the symbiotic relationship where one of the organisms benefits and the other is unaffected b Mutualism is a symbiotic relationship where both organisms benefit c Parasitism is a symbiotic relationship where one organism benefits by deriving nutrients at the expense of the other Occurrence of Disease Sporadic disease Endemic disease Epidemic disease in a short time Pandemic disease Disease that occurs occasionally in a population Disease constantly present in a population Disease acquired by many hosts in a given area Worldwide epidemic Reservoirs of Infection Continual sources of infection AIDS gonorrhea o Human Carriers may have inapparent infections or latent disease symptoms unnoticeable or never exhibited Rabies Lyme disease o Animal Some zoonoses may be transmitted to humans Zoonoses are diseases that are primarily found in wild animals o Nonliving Botulism tetanus The two main reservoirs are soil and water Transmission of disease Contact o Direct Person to Person transmission Requires close association between infected and susceptible hosts touching kissing sexual intercourse o Indirect Occurs when agent of disease is transmitted from its reservoir to a susceptible host by means of a nonliving object usually a fomite tissues towels bedding o Droplet Transmission via airborne droplets o Vehicle Transmission of disease agents by a medium such as food Vehicle and water Vectors o Arthropod vectors are animals that carry pathogens from one host to another fleas ticks o Mechanical Arthropod carries pathogen on feet flies transfer pathogens typhoid fever from
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