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Flashcards in Microbiology Deck (36):
1

Prokaryotic

- Nucleoid (double stranded DNA)
- 70s
- Cell membrane
- Cell wall (peptidoglycan - may be degraded by lysosomes)
- Flagella/pilli
- Plasmid (addition DNA capable of autonomous replication in g-ve)
- Mesosome (vesicles formed by invagination of plasma membrane - cell wall formation/chromosome rep)

2

What does pro lack that eu has

Nuclear membrane
Membrane-bound organelles
Nucleolus

3

peptidoglycan

- provides rigidity
- important for rep and survival in hostile conditions
- infection causes peptidoglycan to interfere with phagocytosis, stim mitosis of lymphocytes and becomes pyrogenic

4

g+ve

predominantly aerobic
- turns purple with stain (trapped in THICK pep wall)

5

g-ve

predominantly anaerobic
- counterstained into red
- THIN pep wall

6

bac cell division

= binary fission
- septum (cross wall) produced

7

morphological classification of pro

from incomplete cleavage of septum

coccus → spherical (staphylococcus)

bacillus → rod-shaped (e coli)

spirillum → snake-like/helical (t pallidum)

8

spores

g+ve (NOT g-ve)
- encases bac/fungal → resistant to env factors
- DORMANT

9

morphological classification of bac

- coccus (spherical) - staphylococcus (chain); streptolococcus (cluster)
- Bacillus (rod-shaped) - e.coli
- Spirillum (helical) - T.pallidum

10

virulence factor of bacteria

invade, infect, evade

11

local effects of bac

- prod enz (exotoxins→prod by g-/+ve)
- damage host cells & cellular components
- forms an abscess (from pus prod bac)

12

systemic effects of bac - septicaemia

wide spread destruction caused by absorption of bac/toxins in blood

13

systemic effects of bac -endotoxin

released by g-ve → triggers immune response → BV dilated → sepsis

14

virus capsid

protein coat containing nucleic acid genome
- withstands harsh env

15

virus envelope

lipid membrane coat
- maintained in aq solution→transmit via fluids

16

genetic form of viruses

DNA or RNA

17

function of viruses

true parasites
- insert genome→hijack host cells→replicate→damage/kill cells

18

viral rep

early phase - penetrate membrane→ release genome
late - genome rep
latent - extracellular infectious viruses not detected

19

viral pathogenesis

acquisition - entry into body
1o site - infection/inflam
2o site - virus amplified & spread→ the incubation period

20

what is convalescence

body repairs the damage

21

herpes simplex viruses type 1 (HSV1)

normally benign, but life threatening in newborn or immunocompromised person

22

rubella in pregnant women

genetic malformation in fetus → developmental effects

23

fungi

- non-motile, aerobic (yeast)
- reproduce by forming spores → increase surv and spread

24

pathogenesis of fungi

mycoses (fungal infection)
- penetrate, colonise, repro

25

protozoa

lacks cell wall→rapid and flexible
develops into a cyst→survives harsh conditions

26

what is a vector

something that carries a virus

27

pathogen

organism that evades various normal defenses→causes infection

28

infection

organism enters body→increase number and damage host

29

commensalism

host and bac live tgt with no effect on each other's life cycle

30

parasitism

un-equal, live off expense of another

31

symbiosis

mutual benefit

32

opportunistic

healthy defences weakened→infect

33

nosocomial

infection transmitted in hospital

34

staphylococcus aureus

common cause of hospital infection
resistant to treatment (MRSA)

35

predictors of MRSA carriage

hospital setting→prolonged/antimicrobial therapy...
community→recent hospitalisation/catheter

36

antibiotic resistance

- loss effectiveness
- innate→intrinsic resistance based on mech of drug
- acquired→of resistance gene, from stimulus (exposure), changes in cell membrane, prod. enz altering antibiotic structure