microbiology Flashcards
1
Q
prokaryotes
A
archea
bacteria
2
Q
eukaryotes
A
fungi
parasites (if not a vector for prokaryotes)
3
Q
whats a prion
A
a protein that sits on the surface of brain cells
4
Q
sterile sites for specimen
A
brain
heart
liver
kidney
5
Q
non sterile sites for specimen collection
A
mouth
oesophagus
lungs
stomach
intestine
6
Q
unstained microscopy can be used to find
A
WBCs- in urine or CSF
parasites in faeces
7
Q
gram stained microscopy can be used to find
A
bacteria
yeasts/ fungi
8
Q
how are viruses detected
A
- molecular- realtime /PCR
- antigen detection
- serology to detirmine immunity- IgN or IgG
9
Q
diagnosis of parasites
A
microscopy of different life stages
10
Q
gram positive bacteria have a
A
thick wall of peptidoglycan on the outside
11
Q
gram negative bacteria have
A
a layer of peptidoglycan underneath lipopolysaccharide
12
Q
gram stain appearance of gram positive bacteria
A
Purple
(Positive- Purple)
13
Q
gram stain appearance of gram negative bacteria
A
red
14
Q
what are bacteria cell walls made from
A
peptidoglycan
15
Q
what happens when a bacterial cell wall is weakened or ruptured
A
osmosis causes it to burst - lysis
16
Q
what does the lipopolysaccharide layer on gram -ve bacteria do
A
- protects peptidoglycan from bile salts and Lysozyme
meaning it can survive in the gut
- blocks many antibiotics
- contains Lipid A which can cause endotoxic shock
17
Q
what are fimbriae for
A
adherence
18
Q
how do bacteria replicate
and become varied
A
binary diffusion
spontaneous mutation and transfer of DNA
19
Q
whats a bacteriophage
A
a virus that eats bacteria
20
Q
name order for bacteria
A
genus then species
staphylococcus aureus
21
Q
virus
A
genetic element that can’t replicate without a host cell
22
Q
virion
A
exists outside a host ad helps transmission
made of nucleic acid genome surrounded by a protein coat
23
Q
virus replication cycle
A
- attatchemnt onto cell
- uncoating inside cell
- genome gets replicated in nucleus
- proteins get made
- virion is made
- virion released with exocytosis
24
Q
coinfection of human and animal virus strains in one organism can lead to
A
generation of a new strain
25
consequences of viral infection
clearance of virus with a level of immunity
chronic infection
latent infection
transformation
26
how can a virus lead to cancer
changing cell cycle
changes apoptosis
persistent inflammation leading to **reactive oxygen species** that cause cancer
27
all antiviral agents are
virostatic- won't kill virus
28
antivirals can be used for
prophyaxix- prevent infection
pre-emptive therapy before symptoms appear
overt disease
suppressive disease
29
prevention of viral infection
* immunisation
* prophylactic treatment post exposure
* IPC
* screening
* antenatal screening
30
adaptive immunity can be
active or passive
31
active immunity includes
infection or exposure
immunisation vaccines
32
passive immunity includes
placental transfer of IgG using **neonatal Fc factor**
colostral transfer of IgA
immunoglobulin therapy or immune cells
33
passive immunity advantages and disadvantages
pros:
immediate
fast
cons:
no immunological memory
anaphylaxis
cell grafts get rejected
34
vaccination definition
giving antigenic material to stimulate immune system to develop **adaptive** immunity
35
temporary contraindications for vaccines
fever
pregnancy- cant have **live attenuated** vaccines
36
permanent contraindications for vaccines
allergy
immunocompromised- can't get attenuated
37
what makes a good vaccine
* potent responses from:
CD8+ Tcells
CD4+ helper Tcells
* memory
38
protozoa parasites include
(single celled organisms)
malaria
amoebae
flagellates
39
helminth parasites include
(worms)
roundworms
tapeworms
flukes
40
ectoparasites parasites include
lice
ticks
mites
41
parasite definition
an organism that lives in or on another **_and derives its nutrients from the host_**
42
vector definition
something that transmits a parasite to a new host- **an intermediate host**
43
protozoa transmission: intestinal
transferred by faecal oral route
44
protozoa transmission: blood or tissue
insect vector
45
Protozoa: parasite and vector that causes malaria
plasmodium
transported by mosquitos
46
Protozoa: symptoms of malaria
fever, chills, flue like symptoms
47
Protozoa: how malaria is seen in blood smear
headphones- crescent shaped with dots on each end
48
Protozoa: parasite that causes amoebic dysentery
ent**amoeba** histolytica
49
Protozoa: amoebic dysentery causes
bloody diarrhoea
intestinal and extraintestinal infections
liver abscess in late disease
50
Protozoa: amoebic dysentery microscopy
cysts formed in stool
51
Helminths: nematodes are \_\_\_worms
round worms
52
Helminths: cestodes are \_\_\_worms
tape
53
Helminths: trematodes are \_\_worms
flat
54
Helminths: nematodes- enterobiasis symptoms and diagnosis
causes anal itch at night
diagnosis by adhesive tape against perianal region in morning
Ova found on microscopy
55
Helminths: nematodes- ascaris lumbricoides problems it causes
often asymptomatic
can cause failure to thrive
can block intestine or bile duct
56
Helminths: cestodes route of transmission and specific problem
raw meat
pork can lead to tapeworm cysts in brain
57
Helminths: trematodes transmission, sign and complication
freshwater where a snail vector is present
swimmers itch
liver failure and bladder cancer
58
diagnosis principles in parasitic infections
blood microscopy- malaria
stool microscopy- ova, cysts, parasites
serology
rapid diagnostic tests
59
helminth infections are often accompanied by
eosinophilia
elevated IgE
60
Gram positive bacteria: aerobic cocci
staphylococci (clusters)
streptococci and enterococci (chains)
61
Gram positive bacteria: staphylococci with apositive coagulase test
staphylococcus aureus:
MSSA/MRSA
62
Gram positive bacteria: staphylococcus
where its commensal and what it can cause
nose, axilla, perineum
boils/abscesses, soft tissue infections, sepsis, osteomyelitis
63
Gram positive bacteria: coagulase negative staphylococci
commensal and problems
skin
biofilms in prostheses
64
Gram positive bacteria: streptococci
haemolysis and agar colour
alpha haemolytic- green
beta haemolytic- clear (complete haemolysis)
non- no difference
65
Gram positive bacteria: example of alpha haemolytic strep
and what it causes
strep pneumoniae
pneumonia, meningitis, sepsis
66
Gram positive bacteria: group A strep name and causes
streptococcus pyogenes
necrotising fasciitis
67
Gram positive bacteria: example of anaerobic
spread and causes
clostridium difficile
spores
diarrhoea and toxin production
increased risk from antibiotics
68
Gram negative bacteria: cocci examples
neiseria spp- meningitis, gonorrhoeae
moraxella catarrhalis- RTI
69
Gram negative bacteria: coliforms are in the family
enterobacteriaceae
70
Gram negative bacteria: what is usually a preliminary test in classifying gram neg bacilli
lactose fermentation
71
Gram negative bacteria: Ecoli and lactose
ferments it
72
Gram negative bacteria: helicobacter pylori
commensal and can cause
curved bacilli
human stomach
can cause ulcers and increase risk of gastric adenocarcinoma
73
Gram negative bacteria: haemophilus influenzae causes
cocco bacilli
RTI
74
bacteria that cant be stained
(no cell wall)
mycobacterium
spirochaetes
chlamydia
75
how are mycobacterium visualised
ziehl-neelsen or Auramine staining
then cultured to find type
76
spirochetes cause and are diagnosed by
syphilis
lyme disease
serology
76
spirochetes cause and are diagnosed by
syphilis
lyme disease
serology
77
what is a fungus
lacks chlorophyll
forms spores
polysaccharides often chitin or glucan in cell wall
ergosterol in membranes
78
athletes foot is caused by
epidermophyton
79
thrush is caused by
candida
80
pityriasis versicolor is caused by
malassezia
81
fungi: main dermatophyte virulence factor
enzymes that degrade and utilize keratin
82
fungi: dermatophytosis causative agents
**epidermo**phyton
83
factors that increase risk of fungal infection
warm moist areas
broad spectrum antibiotics
immunosuppression
84
diagnosis of fungal infections
direct detecion- histophalogy, CT
molecular- PCR, antigens etc.
85
pathogenicity
the capacity of a pathogen to cause infection
86
virulence
capacity to cause harmful effects
- invasiveness
- toxin production
- evasion of immune system
87
an endotoxin is structurally part of
gram negative cell walls
