Term
How big is the bacterial chromosome? |
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Definition
5 million base pairs, 1.3 mm in length (1000x diameter of bacterial cell) |
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Term
Are bacteria haploid or diploid? |
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Definition
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Term
How is the bacteiral chromosome packaged? |
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Definition
by polyamines spermine and spermidine into a structure called a nucleoid |
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Term
T/F The plasmid is replicated at the same time as chromosomal replication. |
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Definition
false, plasmid replicates independently (rplicons) |
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Term
How big is the bacterial plasmid? |
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Definition
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Term
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Definition
plasmids that have integrated into the host bacterium's chromosome |
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Term
What types of genes do plasmids encode? |
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Definition
virulence determinants or resistance to antibiotics |
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Term
T/F A bacterium can have multiple copies of the same plasmid. |
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Definition
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Term
T/F Bacteriophages are lytic viruses. |
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Definition
can be lytic or lysogenic |
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Term
T/F Bacteriophage can encode virulence determinants. |
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Definition
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Term
What type of genome is found in bacteriophages? |
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Definition
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Term
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Definition
when bacteria DNA is packaged into phage proteins which then go on to infect another cell. Transduction can be specialized or generalized |
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Term
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Definition
bacteria take up naked dsDNA (either plasmid or chromosomal DNA) from the environment and incorporate it into the genome |
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Term
What is a "competent" bacteria? |
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Definition
one capable of transformation |
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Term
How is competence induced? |
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Definition
chemically or electrically |
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Term
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Definition
transfer of genetic material from donor to recipient (usually plasmid) via a sex pilus |
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Term
What type of DNA is transfered via conjugation? |
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Definition
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Term
What are simple transposons? |
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Definition
insertion sequences; 150-1500 bps and consists of transposase genes flanked on either side by inverted repeats of 15-40 bps |
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Term
What are complex transposons? |
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Definition
genes in addition ot the transposase are flanked by inverted repeats. Additional genes are usually only for antibioitc resistance or virulence |
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Term
What are virulence islands? |
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Definition
genes encoding a large number of virulence factors are grouped together and flanked by transposon like mobile elements. Transfered horizontally to other bacteria. |
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Term
Name some bacteria that have pathogenicity islands? |
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Definition
helicobacter, salmonella, escherichia, vibrio, pseudomonas |
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Term
What are the four phases of bacterial growth? |
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Definition
lag phase, exponential/log, stationary phase, decline or death phase |
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Term
How can you keep bacteria artifically in log phase? |
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Definition
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Term
What challenges do bacteria in the humna body phase that limits growth? |
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Definition
competition for food and space from commensals, innate defense mechanisms (lysozyme, defensins, etc.), oxidative stress from PMNs, iron limitation |
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Term
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Definition
use of physical procedures or chemical agents to destroy all microbial forms including bacterial spores |
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Term
Describe the different ways you can sterilize something? |
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Definition
steam under pressure (autoclaving, 121C, 15psi, 20 min), dry heat (160, 2 hrs), UV/ionizing radiation, gas vapors (ethylene oxide or formaldehyde gas) |
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Term
How do gas vapors kill bacteria? |
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Definition
ethylene oxide or formaldehyde gas kill by substituting alkyl groups for labile hydrogen atoms |
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Term
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Definition
use of physical procedures or chemical agents to destroy MOST microbial forms; bacterial spores, mycobacteria, viruses, and fungi may remain viable depending on the disinfectant used and the environmental conditions |
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Term
How do chloride compounds like bleach kill bacteria? |
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Definition
oxidizing sufhydryl groups on enzymes |
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Term
What are two examples of disinfection solutions. |
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Definition
chloride compounds (bleach) and phenolic compounds |
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Term
What is antisepsis? give exampels. |
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Definition
use of chemical agents (ethyl or isopropyl alcohol and iodophors) on skin or other living tissue to inhibit or eliminate microbes; no sporocidal activity implied |
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Term
Name examples of virulence factors? |
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Definition
adhesins, invasins, impedins, aggresins, modulins |
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Term
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Definition
bacterial proteins that allow the microbe to bind to a variety of eukaryotic cells, thereby preventing them from being removed by washing or flushing actions; pili and some outer membrane porteins are examples of adhesins |
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Term
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Definition
bacterial proteins that allow a microbe to enter eukaryotic cells; allowing them to be safe from complement mediated killing intracellularly and some antibiotics cannot penetrate eukaryotic cell membranes |
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Term
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Definition
bacterial components which inhibit the operation of host defense mechanisms without actually doing any damage to the host; antiphagocytic capsules or antibody binding proteins (protein A or G) are impedins |
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Term
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Definition
moecules that directly damage the host or actively promote the spread of a pathogen; toxins and protases are examples of aggresins |
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Term
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Definition
bacterial components or substances that modulate host cell activity with pathogenic consequences; superantigens are modulines |
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Term
What types of bacteria are found in dry skin? |
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Definition
staphylococcus epidermidis |
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Term
What microorganisms can be found on moist skin? |
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Definition
staphylococcus aureus, alpha and nonhemolytic streptococci, diptheroids, and fungi (yeasts primarily; candida) |
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Term
What types of bacteria live in hair follicles, sweat and sebaceous glands? |
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Definition
proprionibacterium acnes and other anaerobes |
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Term
When is the mouth colonized? by what? |
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Definition
4-12 hours after birth by viridans streptococci |
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Term
What type of bacterial colonize both the large intestine and the mouth? |
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Definition
streptococci (some potential pathogens), staphylococci (also potential pathogens), diptheroids, and gram negative cocci (neiseria, some of which are potential pathogens) |
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Term
What fungi do some clinically normal people have in their lungs? |
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Definition
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Term
What is the intestinal flora of a breast fed baby? |
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Definition
lactic acid streptococci and lactobacilli |
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Term
What type of bacteria live in the stomach? |
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Definition
acid tolerant lactobacili and streptococci. also helicobacter pylori |
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Term
What type of bacteria are in the upper intestine? |
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Definition
lactobacilli and enterococci |
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Term
What percent of fecal mass is made up of bacteria? |
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Definition
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Term
What types of bacteria are found in the large intestine? |
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Definition
anaerobes (bacteroides), facultative anaerobes |
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Term
The urethra of both sexes contain what kinds of bacteria? |
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Definition
small numbers of the same bacteria found on the skin or perneum (staphylococci, enterococci, diptheroids) |
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Term
What is the vaginal flora at birth? |
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Definition
lactobacilli (persist as long as the pH remains acidic-several weeks) |
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Term
What is bacterial flora of the vagina during childhood? |
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Definition
staphylococci, streptococci, diptheroids and E coli |
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Term
What is the bacterial flora of the vagina at puberty? |
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Definition
lactobacilli, which ferment glycogen to make acid which represses the growth of other organisms |
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Term
What vitamins do gut bacteria supply us with? |
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Definition
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