01 - Intro to Microbiology Flashcards

Question

Most infections associated with protozoa and helminths are associated with issues of?

Answer 1

sanitation; do not see these as often

Answer 2

- generic bacteria is rod shaped - no nuclei - prokaryotic - cell walls are important target to classify bacteria

Answer 3

- no nucleus - have smaller separate circles of DNA known as plasmids - ribosomes smaller than those of eukaryotes - cell wall and cell membrane - external cellular structure such as a flagella or pili

Answer 4

- Encode specific factors for organism - they can be shared with other bacteria - Train other bacteria to be resistant to it - FINISH full dose of antibiotics → eliminate all microorganisms

Answer 5

gram positive or gram negative

Answer 6

MRSA - Resistant to penicillins - It has plasmid that tells it how to work around penicillin - Penicillin cannot work against bacteria

Answer 7

``` ● Shape ● Arrangement ● Colony morphology ● External structures ● Capsules ● Spore formation ```

Answer 8

● Staining and microscopy ● Gram and acid fast (TB) stains ○ Determine if it is a gram positive or gram negative cell wall ○ Helps to determine diagnosis/treatment

Answer 9

oxygen and energy requirements

Answer 10

- carbohydrate utilization and fermentation products

Answer 11

- dna sequencing

Answer 12

● Wide variety in morphology can be identified by direct examination ○ Shape, size, arrangement, presence of spores or capsules

Answer 13

- attached to one another

Answer 14

means organism is round

Answer 15

means the organism is in pairs or chains; always round

Answer 16

means bunches; always round

Answer 17

rod shaped

Answer 18

little bit rod and round

Answer 19

``` ● Characteristics of colonies grown on agar plates = identification For identification: ● Shape (form) of the colony ● Margin/edge ● Elevation ● Surface texture ● Pigmentation ```

Answer 20

- Protein filaments that extend from the cell membrane - Motile (rotate 360°) - Allowing microbe to move in a series of tumbles - Runs in response to stimuli (light, nutrient density, etc…) - Move from low nutrient density to high nutrient density - Bacteria w/flagella have high capacity to make us sick

Answer 21

● Polar – Vibrio spp. (single) ● Spirillium spp. (double) ● Peritrichous – Escherichia coli spp (tons of flagella)

Answer 22

- Straight filaments arising from bacterial cell wall - Facilitate movement - Used to “pull” the bacterium across a substrate - Not used for propulsion - Facilitate formation of biofilms - Shorter than flagella - Act as adhesins Bind to specific host cell receptors - Important role in adherence, a critical step in infection - E. coli spp. & Campylobacter jejuni bind to intestinal epithelial cells

Answer 23

- Used to transfer DNA from one bacteria to another - Facilitate movement of plasmids - Share with other bacteria making them resistant to antibiotics

Answer 24

- two different forms of the same thing - Protective substance surrounding some bacteria - Normally made of polysaccharides - Presence/absence can be used for classification

Answer 25

- Sticky and loose - Prevents dehydration - Allows bacteria to bind to surfaces - Form a protective layer encapsulating colonies of bacteria - Good at holding onto inorganic material ○ Prosthetics ○ Catheters ○ Replacements (hip, heart valve → must all come out) - Difficult to penetrate with antibiotics

Answer 26

- Firmly attached to cell surface - Specific to one bacteria - Virulence factor that facilitates adherence and impairs phagocytosis - Better at making us sick ○ With capsule → highly correlated with severe pneumonia

Answer 27

- Defensive strategy against hostile or unfavorable environmental conditions - Driven by nutrient supply - Spores are not responsive to normal cleaning practices - Metabolically dormant - resistant to heat, cold, drying, chemicals and radiation - Germinate when conditions improve - Excellent defensive strategy

Answer 28

Formed by two genera: Clostridium spp. and Bacillus spp. ● Requires special environmental controls to kill spores ● Cleaning and disinfecting techniques are not sufficient ● Sterilization is required ○ Steam, under pressure, chemical sterilants, etc

Answer 29

- peptidoglycan layer - not observed in human body - makes it easy to identify and get rid of it

Answer 30

● Provides cellular structure and shape ● Counters the effects of osmotic pressure ● Provides rigid platform for external appendages ○ Allows flagella, fimbriae to anchor ● Facilitates adherence to host cells & evasion of host defenses ● Target for antibiotics

Answer 31

two types of bacteria cell wall known as positive or negative

Answer 32

- bacteria retain primary dyes and become a purple colour post-Gram Stain - Thick, dense, non-porous cell walls - Do not possess an outer membrane

Answer 33

- bacteria easily decolorized and take on a pink/red colour post-Gram Stain - Thin cell wall surrounded by outer membrane - The outer membrane contains Lipid A; polysaccharide

Answer 34

- is a pathogen associated molecular lipid protein ○ Component of foreign agent ○ Our body responds to it immunologically ○ Even though we don’t have any direct contact/history with pattern/protein ○ Every human is born with an immune system that recognizes Lipid A as foreign

Answer 35

- thickness, density, porosity, integrity, and chemical composition of cell wall - The Gram Stain is starting point for bacterial identification

Answer 36

gram positive organism | ● More frequently infected with gram positive

Answer 37

more associated with gram negative organisms

Answer 38

true | ○ Some yeasts may absorb gram stain

Answer 39

- gram negative - They should hold onto the crystal violet iodine → they CANNOT - Usually b/c they are physically or chemically damaged - Actual bacteria are dying - Occurs due to poor sampling technique

Answer 40

true; specialized stains are required for some species

Answer 41

Staphylococcus aureus and streptococcus pneumoniae

Answer 42

neutrophils; see them u can confirm bacterial infection

Answer 43

● Diplococci | ● Neisseria gonorrhoeae

Answer 44

Most bacteria do not retain dye carbol fuchsin after treatment with acidic alcohol

Answer 45

● Mycobacterium species do not dye from gram stain ○ e.g. Mycobacterium tuberculosis ● They contain a waxy material (mycolic acids) in their cell wall ○ This retains the stain ○ They are not good at absorbing the gram stain

Answer 46

specifically when mycobacterial infections are suspected ● Not performed on all samples ● Needs to be requested

Answer 47

● Catalase ● Peroxidase ● Superoxide dismutase

Answer 48

false; it is useful

Answer 49

true: Whether or not they like/hate oxygen has to do with their internal capacity to deal with free radicals and oxidative stress

Answer 50

- Its inactivated by enzymes produced by bacteria | - Enzymes neutralize the free radicals

Answer 51

large capacity to live in oxygen rich environment

Answer 52

need to live somewhere with absolutely no oxygen | ● Deep tissue wounds

Answer 53

● Require oxygen to survive ● Possess all 3 enzymes ● Obligate → obligation to live in oxygen rich environment

Answer 54

facultative = flexible ● Prefer to grow in the presence of oxygen ● Can also grow without ● Produce catalase and superoxide dismutase

Answer 55

● Tolerate low amounts of oxygen ○ i.e.: stomach ● Produce superoxide dismutase

Answer 56

● Cannot tolerate oxygen ● Lack enzymes to manage it’s toxicity ● Requires special growth conditions

Answer 57

● Lab needs to test in oxygen and without oxygen ● They won’t have enough if there is only one vial given ● Take two sets of two ○ 2 bottles from aerobic ○ 2 bottles from anaerobic

Answer 58

binary fission # of cells increase exponentially when nutrients are readily available ● Exponential growth phase ● Amount of nutrients is less available → enter stationary phase

Answer 59

true - E. coli doubles every 20 min - Mycobacterium spp. double every few days under optimal conditions

Answer 60

Nutrients are depleted + toxic wastes accumulate → rate of growth slows to a stationary phase ● Without new source of nutrients = bacteria begin to die ● Death phase ● Can occur with poor sampling technique, preparation, and travel times

Answer 61

● Enter lag phase | ● Pathways required to utilize nutrients are reactivated

Answer 62

reproduction (requires conjugation pili) | ● Do not see this as frequently

Answer 63

``` ● Require host cell to live ● Cannot make their own energy ● Grow and reproduce inside the host cell ○ e.g. Chlamydia spp. ● Require cell cultures for growth in laboratory ○ Cannot grow on agar plate ○ They have to grow on tissue culture ○ Have to infect tissue to survive ```

Answer 64

● Can live in host cells if needed ● Capable of getting their own energy required to live too ● Able to survive phagocytosis ● Grow and reproduce within immune cells (macrophages, neutrophils) ○ Outsmart macrophage ○ Do not die when phagocytosed by immune cells ○ e.g. Neisseria spp. ● Shielded from antibodies and other immune defenses ○ Contributes to their ability to survive illness ● Employ specialized mechanisms to protect against lysosomal enzymes in host cell ● They are able to grow on agar plate

Answer 65

● Very few antiviral medications ● Rely on immune system to take care of virus ● We can only provide supportive measures

Answer 66

- no: acellular not alive ● They are a bit of genetic material ○ Either DNA or RNA wrapped in capsule

Answer 67

● Cannot replicate (multiply) independently ● Must replicate inside host cells ● Using enzymes, organelles and energy from the host cell to increase in number

Answer 68

● Possess DNA or RNA | ● Supported by a protein capsule or “capsid”

Answer 69

● Possess DNA or RNA | ● Supported by a protein capsule or “capsid”

Answer 70

○ Protection | ○ Provide recognition sites that bind to receptors on host cells

Answer 71

- Some viruses also possess an “envelope” derived from host cells - Leave host cell and drag host cell with them - Facilitates entry into host cells - Cellular membrane proteins are replaced with virus-derived proteins

Answer 72

● Virion structure ● Mechanism of replication ● Nature of genome ● Molecular techniques ***

Answer 73

● Host and tissue range, cytopathic effect on host cell ● Nature of disease ● Serological reactions ○ Draw blood and look for antibodies ● Amino acid sequences of viral proteins, nucleic acid sequences

Answer 74

● Replicate in linear process ● Cannot reproduce independently ○ Nothing until all the viruses have left the cell ○ People feel bad and then all the sudden feel like trash ○ Little viral load → lots of viral load ● Lack enzymes necessary for replication ● Do not possess ribosomes for protein synthesis ● Once under control of a viral genome, host cell is forced to replicate viral genetic material and translate viral proteins

Answer 75

Specific molecular interaction with a host cell receptor

Answer 76

Entry via direct penetration, membrane fusion, or endocytosis - Uncoating; required for viruses that enter the host cell with their capsid intact - Capsid is removed

Answer 77

● Strategy varies depending on nucleic acid (ie; DNA, RNA, ds, ss) ● DNA synthesis occurs in nucleus ● RNA synthesis in cytoplasm

Answer 78

Once components are synthesized → assembled into virions

Answer 79

Budding ○ Leave host cell keeping it intact ○ Drag host cell membrane creating viral envelope ○ Enveloped viruses are released via budding Exocytosis ○ Leave host cell keeping it intact ○ Does not take any cell membrane Lysis ○ Naked virus released via host cell lysis ○ Destroying the host cell ○ Tear cell open to make its way out to infect other tissues ○ MOST VIOLENT

Answer 80

● Body has seen this type of infection before → memory cells at work ● Little or no detectable effect ● Eliminate before any symptoms/signs

Answer 81

● Alteration of antigenic specificity of cell surface ○ Due to presence of virus glycoproteins ● Host cell function is intact leading to gradual prolonged release of progeny viral particles ● Consistent and chronic viral illness

Answer 82

herpes, chicken pox, shingles ● Acquires virus → active infection → undergo latency period ○ No more symptoms ● Persistence of viral genome in cell with no virus progeny produced ● Latent virus can be reactivated months to years later (stress, age, friction on skin) ● Resulting in a productive infection ● Cannot cure = can only prolong latency periods

Answer 83

cervical, penis, anal, and throat cancers ● Integration of viral genome into host cell chromosome ○ Cause fatal mutations ○ Leading to cancer ● Disruption of host cell metabolic functions including cell growth and replication ○ Resulting in the induction of tumours

Answer 84

rapid lysis of host cell and release of progeny

Answer 85

● Grow as single cells (yeast) or as multicellular filamentous colonies (molds) ● Most are not pathogenic ● They are saprophytic ○ Obtain food from dead organic matter ● Classified and identified based on their characteristic structures, colors, habitats, carbohydrate utilization, modes of growth and reproduction ● In lab → fungi are identified by direct examination/cultured to examine their characteristic structures

Answer 86

Obtain food from dead organic matter

Answer 87

Obtain food from dead organic matter

Answer 88

● Single cells | ● Reproduce via budding

Answer 89

● Multicellular filamentous colonies, called hyphae ● A mat of overlapping hyphae are called mycelia ● Reproduce via asexual spore formation ● Spores germinate to generate new organisms once an ideal environment is found

Answer 90

● Capable of growing in both forms (yeast & mold) ○ Mold out in environment ○ Yeast inside the host ● Reproduce via asexual spore formation ● Spores germinate to generate new organisms once an ideal environment is found

Answer 91

- yeasts, unicellular, budding

Answer 92

- molds, hyphae, spores

Answer 93

● Antimicrobial drugs that target the bacterial cell wall will have no effect on fungi ● Fungi DON’T have peptidoglycan (this makes up bacteria cell wall)

Answer 94

● Limited number of drugs that target the differences between fungi and mammals ○ Cholesterol found in mammalian cell membranes ● Many antifungal cause difficult to tolerate adverse effects

Answer 95

- Fungal cell membrane contains ergosterol | - Fungal cell walls composed of chitin

Answer 96

● Chronic fungal infections ○ Pathogens grow very slowly ● Classified into 5 groups depending on tissue involved and mode of entry

Answer 97

● Outermost layer of skin, nails and hair (superficial) | ● Treated topically

Answer 98

- Keratinized layers of the skin, hair and nails - Ringworm or athlete's foot - Caused by dermatophytes - Host immune response may be stimulated - Itchy, scaling skin that may become inflamed - Transmission human to human (or animal to human) via infected skin - Topical therapy may not be sufficient - Especially in later stages or when nails are involved - Too deep = require oral medication

Answer 99

● Do not see frequently in Canada ○ More in developing countries ● Involve the dermis, subcutaneous tissues, muscle and fascia ● Most infections are chronic ● Expressed clinically as lesions on the skin surface ○ Initiated by trauma to the skin ● Difficult to treat ● Surgical excision or amputation often required

Answer 100

``` ● Originate primarily in the lungs ● Travel to distal sites ● Fungi found in soil and feces of birds and bats ● Geographically defined ○ Associated with inhaled spores ```

Answer 101

● Observed in individuals with impaired host defenses | ● Alteration of normal flora, AIDS, DM, immunosuppressive therapy, cancer

Answer 102

Parasitic → protozoa and helminths | ● Different than PARASITISM

Answer 103

- Most common in developing or tropical regions ○ Sanitation is poor ○ Control of vectors is limited - At some point in life-cycle have a microscopic phase ○ Require microscope to observe them - Throughout the world ~70% of humans are infected with a parasite - Parasitic infections are long and chronic ○ Sometimes they are very serious ○ Especially in immunocompromised patients

Answer 104

- Eukaryotic ○ Antimicrobials can be associated with toxicity in humans - Unicellular - Lack a cell wall - All exist in a motile, feeding “trophozoite” stage ○ Active ○ Moving, growing, and reproducing ○ Cause active disease in individual ○ They will become symptomatic - Many protozoa revert to a hardy, dormant “cyst” stage ○ Hibernating ○ Thick capsule and a low metabolic rate ○ Protects parasite from poor environmental factors ○ Infective form ○ This is the form we find it in the environment

Answer 105

● GI and urogenital tracts ○ STIs associated with protozoa ● Blood and tissues

Answer 106

- categorize them based on how they move on a wet mount slide - Protozoa have different ways of moving - Some have any of the following

Answer 107

● Move by extending cytoplasmic projections outward from main body ● Use pseudopods to move themself along the slide

Answer 108

● Whip-like projections rotate and propel the organism

Answer 109

● Hair-like projections cover cell-surface and beat in unison to move cell forward

Answer 110

● Generally non-motile | ● Adult males sometimes have flagella

Answer 111

yields more rapid results

Answer 112

● Typically asexual ○ Binary fission ● Some reproduce by meiotic (sexual) division

Answer 113

○ Protozoa is contained within organism that interacts w/us to transfer protozoa into our blood ○ Mosquitoes, tsetse fly, rats

Answer 114

○ Snails, pigs, beef, fish

Answer 115

● Ingestion or penetration of anatomical barrier (ie: insect bite) ● Followed by attachment, replication, and host damage as organism is released from host tissues

Answer 116

● Thin, soft body that is flattened dorsoventrally | ○ They are squished

Answer 117

Trematoda: ● Flukes ○ Liver, blood and lung flukes ● All are parasitic Cestoidea: ● Tapeworms ○ Beef, pork, and fish can all posess tapeworms ● All are parasitic

Answer 118

``` ● Cylindrical shaped body, tapered at end, unsegmented ● Intestinal ○ E.g. pinworm ● Blood and Tissue ○ E.g. Filarial worms and dog worm) ```

Answer 119

● Adult tapeworms live in the small intestine of humans ● Attach to intestinal wall by the scolex ○ Scolex consists of hooks and up to four suckers ● A tapeworm grows by the addition of body segments ○ Up to 3 - 5 meters long ○ Living up to 25 years ● Detected by the presence of ova (eggs) or proglottids (segments) in feces ○ Find segments wriggling and moving in stool

Answer 120

``` ● Diarrhea ● Increased appetite ○ They are ingesting a lot but not gaining any weight ○ Calories are going to the worm ● Intestinal obstruction ○ If they are sufficiently long ```

Answer 121

E.g. Taenia solium ● Commonly known as the pork tapeworm ● Acquired by ingesting larva present in muscle tissue of a pig

Answer 122

More common infection in children ● Child has pinworm infection ● It begins to grow ● Female forms of worm develop ● Worm crawls out of intestine to the anus ● Female worm lays eggs on the anus ● Makes child's anus itchy ● They do not wash their hands → touch something → others can acquire it ● Ingestion of ova present on hands, fomites or linens ○ Eggs are able to survive bed sheets, hard surfaces and areas distal to intestine

Answer 123

● Nocturnal itching at the anus.

Answer 124

● Wait til child is asleep, get them in froggy position, shine flashlight on anus ○ Parasite is attracted to the light ○ Female is most active in the evening ○ Attracts female worms ● Collecting ova or female worms from anal region using tape ● Worms visible in stool during the day ○ Easier in the evening There is an oral antiparasitic medication that turns stool pink → EXPECTED

Answer 125

Life-cycles are highly complex

Answer 126

Definitive host → sexual cycle takes place Intermediate host → asexual cycle takes place Paratenic host → no change in stage or development

Answer 127

○ Anopheles mosquito is the definitive host ■ Sexual cycle occurs ○ Humans are the intermediate host ■ Asexual cycle occurs

Answer 128

○ Humans are both the definitive and intermediate host

Answer 129

● Ingestion of larvae in raw undercooked pig, beef, fish ● Ingestion of helminth eggs (feces) ● Insect bites or direct penetration through skin ● Life cycle is key to understanding the infectious process, time course of disease and symptomatology