Microbiology

Question 1

Forms of Bacteria

Answer 1

Coccus

Bacillus

Sprirlli

Question 2

Gram Positive Bacteria (reason, examples)

Answer 2

Staphylococcus aureus

Streptococcus pneumoniae

Streptococcus pyogenes

One Cell membrane+ thick Cell wall –> peptidoglycans in Cell wall keep colour of gram stain

Question 3

Gramm Negative

Answer 3

Question 4

Gram Negative bacterias examples

Answer 4

E-coli

Salmonella

Shigella

Vibro cholerae

Neisseria

Question 5

Which steps are required for bacterias to cause illness?

Answer 5

1. Colonize
2. Persist –> immune response, physical etc.
3. Replicate –> nutrients required
4. Spread
5. Cause Disease –> Produce toxins, affect immune respone, induce diorhe

Question 6

Extracellular Pathogens

Answer 6

predominanatly outside of cells

Staphylococcus

Strptococcus

Yersinia

Neisseria

Question 7

Intracellular Pathogens

Answer 7

Mainly inside of cell

Can:

Escape in Cell (Listeria Shigella)

Prevent fusion with lysosomes (Salmonella, Mycrobacteria)

Fusion with lysosomes and formation of pagolysosome (Coxiella)

Question 8

Horizontal Bacterial DNA exchange:

Answer 8

Transformation: DNA uptake of free DNA

Conjugation: Sharing of plasmid ring throuhg mating bridge

Transduction: uptake of bacterial DNA through Phage (Virus) and further spread

Question 9

A Pathogenicity Island

Answer 9

DNA fragment that contributes to disease

Question 10

Injectiosome

Answer 10

Action fragment that sticks out of bacteria, used to be injected in cells –> modification of Actin filament –> engulfment

Question 11

Flagella

Answer 11

“Tail” of bacteria

Actin fillament

Used fo movement

Question 12

Bacterial Infectivity

Answer 12

General stragegie which help to cause infection (–> direct effect on infectious dose)

Transmission

Colonization

Tropism Finding unique niche

Replication

Avoid immune defence of host

Question 13

Bacterial Virulence

Answer 13

Ability to cause disease

• production of toxins
• Enzymes that influence host function
• Interfere with host normal function
• complete immune invastion

Question 14

Infective dose

Answer 14

Number of bacteria which can cause disease (dependant on Infectivity)

Question 15

Potential sources

Answer 15

Intrinsic (self infection)

Extrinsic (environment)

Question 16

Possible routs of bacterial infections

Answer 16

Upper respiratory trackt –> Upper respiratory trackt infection, lower rewpiratory trackt infection, Spread to adjacent tissues (e.g. ear, brain,) –> Spread to bloodstram

Urogenital trackt –> Bloodstream and/or Pregnancy, Baby (genital)

Broken skin

Gastro-intestinal trackt

Question 17

Neisseria

Answer 17

Gram negative

• Meningititis (Neisseria meningitidis (Meningokokken)–> Tröpfcheninfetktionen

Neisseria Gonorrhoeae ( cause Tripper) –> sexuell übertragbar

Question 18

Haemophilus influenzae

Answer 18

Gram negative

bacillus

Tröpfcheninfektion

Mainly symptoms in upper respiratory trackt

Question 19

Escherichia coli

Answer 19

Gram negative

Question 20

Sources of bacterial infection

Answer 20

Intrinsc (any non-sterile site of body)

Extrinsic (outside world)

Question 21

Expected vs unexpected portals of entry

Answer 21

Expected: Harmless bacterial via expected route

Unexpected: Harmless via unexpected route or pathogenic bacteria via any route

Question 22

Possible routes of infection : Upper respiratory trackt + examples

Answer 22

Upper respiratory trackt –> adjacent tissue /lower respiratory trackt

Bloodstream

Mouth: e.g. streptococcus pyogenes –> Tonsilitis

Neisseria meningitidis –> Meningococcal septicemis

Upper respiratory: S. pneumonia/pneumonia

Question 23

Possible routes of infection: Urogenital trackt

Answer 23

Urinatry infection –> Bloodstream

Genital –>( pregnangy related) 1.GBS/neonatal meningitis).–> Bloodstream

Question 24

Possible routes of infection : broken skin

Answer 24

selbsterklärend

e.g. staph. A.

streptococcus pyogens

Question 25

Possible routes of infection: GI examples

Answer 25

Cholera

Question 26

Commensals

Answer 26

Bacterial that do not cause disease

Question 27

Infectivity

Answer 27

"Infectious dose" --\> how much needed to cause disease * Transmission * Colonisation * Tropism– Find unique niche (in or outside cells) * Replication Immune Evasion

Question 28

Virulence

Answer 28

Enhances disease causation: Toxin Production, Enzyme secretion, interfere with normal host, immune supression

Question 29

Salmonella sp.

Answer 29

Gram negative causes GI infection

Question 30

Vibrio cholerae

Answer 30

GI infection Gram - rice water stool (NA and CL) ioons

Question 31

Shigella

Answer 31

Gramm -, rods infection of epithelia in stomach --\> diarreah

Question 32

Staph. A

Answer 32

Gram + causes many infections

Question 33

Reason for high rates of HAI

Answer 33

- many sick people at one place (spread + aquire easily) - use of antibiotics

Question 34

Antibiotic: Aminoglycosides

Answer 34

integrate wrong / not functinoal AA in proteins (target Ribosomes) --\> membrane damage, proofreading

Question 35

Antibiotics: Rifampicin

Answer 35

targets RNA polymerase subunit --\> prevents transcription

Question 36

Antibiotics: Vancomycin

Answer 36

cell membrane synthesis

Question 37

Antibiotics: Linezalid

Answer 37

bind to 50S ribosomal Subunit, prevent protein synthesis

Question 38

Antibiotic: Daptomycin

Answer 38

Bacterial cell membrane

Question 39

Selective Toxycity

Answer 39

Antibiotics target many different bacterial processes

Question 40

Why resistance higher morbidity, mortality and cost

Answer 40

Longer time til effective treatment additional treatments (e.g. surgery) required new, expensive drugs more toxic or less effective drugs

Question 41

Mechanisms of drug resistance

Answer 41

1. change targeted site 2. inactivation (e.g. enzymatic degradation) 3. Alternative metabolic pathway (inhibited process not required, overexpression --\> enough to survive) 4. Decrease drug accumulation (don't let drug in, pump it out)

Question 42

Nature of viruses

Answer 42

Intracellular, obligate pathogens small (20-200nm) genetic and structural diverse

Question 43

Enveloped viruses

Answer 43

enveoped by lipid of host cell membrane can be any shape

Question 44

Capsid viruses

Answer 44

Non enveloped (protein capsule)

Question 45

Virus classification

Answer 45

Baltimore classification system: Single, double stranded, positive negatvie sense (negative = complementary to DNA), RNA, DNA viruses etc. --\> way of genome replication within cell