Microbiology Test 3 outline Archea Prokaryote No Branched chains ether linkage Met Bacteria Prokaryote Yes Straight chain ester linkage Formylmethionine Eukarya Eukaryote No carbs Straight chains ester linkage Met Yes Yes Yes No No Yes Lecture 17 18 Bacteria Cell type Peptidoglycan Membrane lipids First AA in protein synthesis Antibiotic sensitivity No No rRNA loop tRNA No Bacteria Characteristics Peptidoglycan walls 70S ribosomes Single circular ds DNA Prokaryotes 2 main groups o Peptidoglycan rRNA signature Domain bacteria Proteobacteria Gram negative Most human pathogens Alpha Rhizobium Nitrogen fixation Agrobacterium Transgenic plant Rickettsia Obligate intracellular parasite mitochondrial origin Beta Neisseria meningitidis gonorrhoeae Bordetella pertussis Spirillum Gamma Enterics E Coli Salmonella Shigella Yersinia relatives The Vibrios cholerae Haemophilus Pseudomonas opportunistic Legionella Coxiella Francisella Delta Prey Epsilon Helicobacter Peptic ulcers Campylobacter diarrhea o Gram positive bacteria Thick peptidoglycan Tetichoic acids Wall less forms Mycoplasmas Acid fast mycobacteria o The low GC gram positive bacteria 1 The Bacillus class Bacillus anthracis thuringiensis the aerobic spore formers The Streptococcus many pathogens The Staphylococcus Aureus Listeria monocytogenes 2 The Clostridial class obligate anaerobic spore formers C Botulinum causes botulism C tetani causes tetanus 3 The wall less bacteria Mycoplasma o The high GC gram positive bacteria Actinomyces Streptomyces Mycobacterium and other acid fast bacteria can t make ATP o Spirochaetes axial filaments Treponema pallidum syphilis Borrelia burgdorferi lyme disease o Chlamydia obligate intracellular parasites life cycles associated diseases Life cycle elementary non growing reticulate vegetative cell Domain Archea o Extremophiles Microbial diversity o Size o Many not identified Lecture 19 Principles of Disease and Epidemiology Etiology the study of the cause of a disease Infection does not equal disease Normal microbiota and the host Normal permanently colonize the host Transient microbiota can be present for days to months Symbiosis relationship between normal microbiota and host o GI tract and bacteria sea anemone and hermit crab o Mutualism Parasitism Infectious disease process Parasitism organism benefits at expense of other o Parasitism mutualism Reestablishment of a healthy host occurs Mutualism both organisms benefit o Commensalism one organism benefits the other is unaffected o Microbial antagonism competition between microbes o Normal microbiota protect host o Probiotics live microbes put into the body for benefit Koch s Postulates Microorganisms isolated from dead animal Grown on a pure colony Injected into a healthy host Isolated from animal and identified Exceptions o Some pathogens cause several diseases one pathogen can have different symptoms o Some only cause disease in humans o Some need cofactors will not develop without them o Disease development can take years Infectious diseases Occurrence of Disease Noncommunicable a disease that is not transmitted from one host to another Communicable spread from one host to another Contagious easily spread from host to another o Direct requires close association between infected and susceptible host Sporadic occurs occasionally in a population Endemic constantly present in a population Epidemic acquired by many hosts in a given area in a short time Pandemic disease worldwide epidemic Reservoirs of Infection Continual sources of infection o Human AIDS carriers may have unapparent infections o Animal zoonoses may be transmitted to humans o Nonliving soil and water Transmission of disease Contact kissing sex o Indirect fomites tissue bedding cups money o Droplet Transmission via airborne droplets o Transmission by inanimate reservoir food water o Mechanical carries pathogen on feet flies feces food o Biological pathogen reproduces in vector lymes Vehicle Vectors Epidemiology John Snow and Cholera know this dude Relationships of human disease agents Study of disease in populations Where and when diseases occur o Occurrence o Distribution o Control and prevention Nightingale sanitation Semmelweis hand washing Surveillance CDC o Morbidity and Mortality Weekly Report Morbidity incidence of disease Mortality death from disease Morbidity rate of people affected in certain time Mortality rate deaths from disease in given time WHO world health organization Lecture 20 Nosocomial Infections and emerging infectious diseases EIDs Nosocomial Infections Hospital acquired 5 15 of patients Lister used carbolic acid to prevent these infections History o Puerperal fever incidence decreased by hand washing o Nightingale sanitation decreases epidemic typhus o Koch Pasteur germ theory of disease o MRSA hospital infection Incidence and types o 8th leading cause of death in US o Surveillance WHO CDC NNIS see lecture 19 o Hemodialysis IC catheter surgery bladder catheter ventilator o Most frequent drug resistant Gram negative bacteria o Most susceptible patients with burns wounds and suppressed immune In the hospital functions Transmission o Direct contact Patients staff members patients patients Fomites can transmit infections Prevention and control o Sanitize isolate barriers sterilization Emerging Infections o new reemerging or drug resistant infections whose incidence in humans has increased within the past 2 decades or whose incidence threatens to increase in the near future o Soooo a disease that is growing a lot or is predicted to grow a lot o Ex leukemia lymphoma lyme toxic shock syndrome etc What contributes to these infections o Crowding o Sexual mores HIV STD o Drug use HIV Hepatitis C o Eating out produce mass food production o Populations with a weakened immune system o Technology organ transplants new drugs blood transfusions o Changing ecology dams deforestation o Exposure to wild animals and vectors o Travel SARS food from other countries vectors on imported products o Antibiotic resistance moving from animals to humans o Inadequate public health measures o Intent to harm bioterrorism bio crimes Biological Safety Levels BSL BSL I normal sterilizations II agents with little risk of aerosol transmission III Negative air pressure agents can be transmitted by inhalation IV Complete isolation positive pressure lab suits o Ebola Lecture 21 22 Microbial Mechanisms of pathogenicity I and II Pathology The study of disease o Opportunists virulent Pathogenicity
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