Test One – Microbiology – Flashcards
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| Phylogenetic classification is based on what kind of relationships? |
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| Natural relationships |
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| Arrangement of organisms into taxonomic groups is based on their what? |
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| Degree of relatedness |
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| Spherical? |
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| Coccus/cocci |
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| Rod? |
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| Bacillus/bacilli |
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| Describe the four steps of simple staining? |
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| 1) Flood slide with crystal violet (everything purple) 2) apply iodine (fixes gram + as purple) 3) apply alcohol (gram - is washed of color) 4) Apply pink dye, safranin (gram - turns pink) |
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| What is the simplest stain? |
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| Negative stain. i.e. Indian ink. |
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| Genetics uses what amino acids to classify bacteria? |
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| G and C. The number of these amino acids is very characteristic of the species. |
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| What is the ideal classification? |
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| Phylogenetic or evolutionary relationships. It's based on analysis of macromolecules like DNA, RNA and protein. Sequences give fundamental degree of relatedness. |
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| Helminths? |
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| Pinworm, Hookworm (from soil in south) |
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| Protozoa? (amoeba, cilliates) |
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| Pneumocystis pneumonia, malaria, elephantitis, african sleeping sickness |
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| Fungi? |
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| Thrush (infected mucous membrane), ringworm, athlete's foot, jock itch |
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| Mycoplasma? |
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| Walking pneumonia |
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| Bacteria? |
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| UTI, pneumococcal pneumonia, gastroenteritis, wound infection |
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| Rickettsia/ Chlamydia? |
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| Rocky mountain spotted fever, trachoma, non-gonococcal urethritis |
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| Viruses? |
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| AIDS, common cold, Flu |
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| The normal adult contains how many microorganisms? |
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| 1x10^14 |
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| Where does natural flora come from? |
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| Est. shortly after birth from surroundings. |
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| Commensalism? |
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| Benefit from host without doing harm. |
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| Mutaulistic? |
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| Both host and N.F. benefit. |
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| How much energy do we derive from N.F.? |
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| Roughly 2% |
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| Which vitamins are N.F. derived? |
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| K and B vitamins. |
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| Germ-free animals exhibit what (3) things which speaking of the immune system? |
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| 1) smaller lymph nodes 2) fewer lymphocytes, phago 3) lower antibody levels |
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| Explain the (4) traits of colonization resistance and bacterial interference by N.F. |
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| 1) defend against colonization by pathogens 2) out-compete other organisms for nutrients 3) specialized structures help adhere to host 4) produce bateriocins - substances that inhibit growth of other organisms (made by 1, but inhibit many) |
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| Which flora are disturbed most easily? |
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| Intestinal |
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| N.F. characteristics of the 1) stomach, 2) upper intestines and 3) the colon? |
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| 1) <10 org/ml, low pH, Helicobacter pylori (ulcers) 2) 10^3 org/ml, [bile salts] high, [digestive enzyme] high 3) 10^10 bact/g of feces (largest population 99% anaerobes) |
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| Vaginal pH during child-bearing years and why? |
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| 3.6-4.5, estrogen -> glycogen -> lactobacilli making lactic acid |
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| What part of the body has the widest VARIETY? How many species? |
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| The mouth. >500 recognized species |
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| (3) sites that should remain sterile. |
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| Blood, body fluids (CSF) and tissues |
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| Which has more than just a peptidoglycan layer, G+ or G-? |
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| G- has other layers |
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| A glycocalyx is composed of what? |
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| Polymer of polysaccharides |
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| What is the major characteristic of the gram+ cell? |
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| Peptidoglycan wall, it may weigh up to 50% or more of the dry weight of the cell |
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| Which (3) peptide cross links are unique in the bacterial cell wall? |
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| 1) D-glutamic acid 2) D-alanine 3) meso-diaminolimelic acid (DAP) |
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| Lysozyme cleavage happens where? |
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| Between the beta bond of the polysaccharide chain. (Peptide bridge?) |
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| What (3) functions does the periplasmic space have in Gram- bacteria? |
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| 1) degrade macromolecules 2) protect against toxic intruders 3) gather (bind) essential nutrients and deliver to transport proteins. |
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| What are the (3) parts of a LPS? |
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| 1) O polysaccharide side chain (extend outward from the core) 2) core polysaccharide (contains charged sugars and phosphate, negative charge) 3) lipid A (potent toxin) |
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| Name a good example of an aerobe and an anaerobe? |
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| aerobe: TB anaerobe: Tetanus |
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| How does respiration occur in aerobes and in anaerobes? |
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| aerobes: glycolytic anaerobes: nitrate and sulfate, fermentative pathways (lactic, ethanol, mixed acid, butanediol, butyric acid) |
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| Difference between virulent and temperate bacteriophages? |
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| Virulent is always lysis (generalized transduction), temperate can be lysis or lysogeny (specialized transduction) |
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| Conjugation? |
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| Plasmid driven genetic exchange, requires the presence of 'F factor' plasmid and cell-to-cell contact. |
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| F- is the (recipient or donor) and the F+ is the (recipient or donor)? |
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| recipient and donor |
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| F+ and F- matings can occur between bacteria of different species T or F? |
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| True |
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| The F factor gene is coded on what section of the DNA strand? |
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| OriT |
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| Where on transposons is antibiotic resistance and substrate metabolism located? |
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| Central region |
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| What are responsible for "phase variations"? |
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| Transposons |
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| (5) general characteristics of Enterobacteriaceae. |
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| 1) g- 2) fermentative 3) oxidase-negative 4) aerobic and anaerobic 5) nonmotile or motile by pertrichous flagella |
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| (4) Main bad guys of Enterobact.? |
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| 1)Salmonella 2)Shigella 3)E. coli (some strains) 4)Yersinia |
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| Name the pathogenic E. coli. |
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| P Enteropathogenic I Enteroinvasive T Enterotoxigenic H Enterohemorrhagic |
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| (2) main point of Enterohemorrhagic. |
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| -4th leading cause of diarrhea -Hemolytic uremic syndrome -> kidney failure in old and young -H7 |
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| What is the most common cause of UTI? |
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| Extraintestinal infection by E. coli |
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| Of the 8 subspecies on Salmonella, which is most common to humans? |
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| Subspecies 1 |
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| Main disease caused by Samonella subspecies 1 are? (3) |
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| 1) Typhoid fever (S. typhi) 2) Paratyphoid fever (S. paratyphi A and B) 3) Gasteroenteritis (S. typhimurium) |
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| Shigella can cause what (2) main things? |
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| 1)Dysentary 2)Gastroenteritis |
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| Yersinia, (2) characteristics. |
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| 1) plasmids with virulent genes 2) resist phagocytic killing |
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| Responsible for plague, Black Death? |
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| Yersinia pestis |
