microbiology(shite) Flashcards
(104 cards)
1
Q
parts of the upper resp tract
A
nasal cavity
larynx
pharynx
2
Q
parts of lower resp tract
A
trachea
primary bronchi
lungs
3
Q
upper resp defenses
A
cough
flush action of saliva
muco-cilliary defence
tonsils
nose hair filters
4
Q
lower resp defenses
A
muco-cilliary clearance
macrophages in aveoli
bronchus associated lymphoid tissue
5
Q
common cold causes
A
90% caused by virus’
1)rhinovirus
2)coronavirus
3)influenza
6
Q
coomon cold manifestation
A
incubation period:12 hours- 2days
rhinorrhea
sneezing
coughing
headache
7
Q
common cold treatment
A
antihistamines,paracetamol,hydration,
handwashing
(no effective anti-viral)
8
Q
causes of pharyngitis and tonsilitis(ur)
A
70-80% virus
eg. rhinovirus, coronavirus,influenza
10-30% bacteria
eg. group A strep
group C and G strep
gonorhea
9
Q
symptoms of acute pharyngitis caused by strep pyg(ur)
A
high fever > 38 c and chills
enlarged painful tonsils with white pus filled tonsils
swollen lymph nodes
10
Q
GABHS pharyngitis complications suppurative(generating pus)(ur)
A
peritonsillar abscess(quinsy)
otitis media
sinusitis
mastoditis
11
Q
GABHS pharyngitis complications non-suppurative(no pus)(ur)
A
scarlet fever
–> rash and strawberry tongue due to a toxin
acute Glomerulonephitis
1-2 weeks post sore throat
–> circulating immune complexes are deposited in glemorulei
–>activate compliment coagulation system–> inflammation
rheumatic fever
rheumatic heart disease
12
Q
diptheria cause and action
A
toxin-producing strains of corynebacterie diptheria
destroys epithelial cells
inflammation+swelling
can damage heart n liver
necroatic exudate- “false membrane” blocks airways
13
Q
diptheria prevention
A
isolation
anti-bacteria
anti-toxin
contact tracing
VACCINATION(as child)
14
Q
what causes glandular fever
A
caused by epstein bar virus(EBV)
transmitted by saliva
15
Q
clinical features of Glandular fever
A
fever,anorexia,lethargy,sore throat, headache
16
Q
acute laryngitis
A
cause:virus(like common cold)
symp:cough hoarseness,barking cough
17
Q
who is susceptible to croup and epiglottitis
A
acute inflam diseases involving the airway
danger of airway obstruction
18
Q
acute epiglottitis
A
diagnosis: blood culture
management: maintenance of adequate airway
examination of orphynx
antibiotics-due to bacterial cause
prevention: Hib vaccine
19
Q
two types of acute sinusitis
A
community acquired
hospital acquired( critically ill and mechanically ventilated)
20
Q
two types of community acquired sinusitis
A
viral and bacteria
viral
associated with upper respiratory infections
bacteria
21
Q
two types of otitis
A
externa and media
22
Q
externa otitis
A
severe necrotizing infection that spreads to adjacent soft tissue,blood vessels
antibiotics as treatment (urgent matter)
23
Q
media otitis
A
middle ear inflam+ fluid
(usually conseq of uresp infection)
24
Q
gastroenteritis
A
characterised by GI symptoms
25
diarrhea
frequent and/or liquid stool, usually small intestine disease linked to enterotoxin
26
dysentry
infalmm disorder of the GIT, blood and pus in faeces, pain fever, abdominal cramps, large intestine disease
27
enterocolitis
inflammation of the mucosa of small and large intestine
28
non typhoid salmonella
-most prevelant
-acute, mostly self limiting episodes of diarrhoea
-usually transferred to humans via food but need large infectious dose
29
typhoidal salmonella
-can cause enteric fvr
-person-person spread is via contaminated food/water
-fevers, malaise, aches, diarrhoea, constipation
-large infectious dose required
30
how is salmonella diagnosed
culture, blood culture if bacteraemia(bacteria in blood) suspected
31
how is salmonella treated
fluid and electrolytes, no antibiotics(don't want to wipe out natural flora)
32
what is enteric fever
fever, malaise, aches, diarrhoea, constipation
from salmonella typhi and paratyphi
rose spots for 1-2 days
infectious period is 10-14 days
33
what is the infectious doese needed for E coli
> 10^5
34
shigellosis
a bacterial infection of the digestive tract caused by the Shigella bacteria
bacterial dysentery
faecal spread
paediatric disease
gastroenteritis, watery diarrhoea which later contains mucus and blood
S.dysenteriae= MOST SEVERE
--> can get into bloodstream and destroy endothelial cells of the kidney
35
campylobacter
highly infectious
contaminated food
ulceration+ inflamed bleeding of mucosal surfaces in jejunum, illeum and colon
antibiotics
36
cholerea
gram neg
contaminated food/water-high infectious dose
"rice water stool"
massive fluid loss and electrolye imbalance
diagnose via culture
37
clostridiodes difficle
normanl gut flora and allow c.difficle to multiply
enterotoxins:
toxin A:increased intestinal permeability and secretion
toxin B: results in colonic inflammation, hemostasis and tissue necrosis in the colon
tx:metronidazole, faecel microbiota transplantation
38
food poisoning
consumption of food containing toxins
acts within hours
39
foodbrone infections
food acts as a vechile for pathogene or provide conditions for it to multiply
40
staph food poisoning
50% produce enterotoxin
heating kills bacteria
short infectious period: 1-6 hours after consumption
vomiting
self limiting
41
Bacillus cerus
usually from improperly stored rice
gram +ve
spores survive cooking, germiate on cooling
rapid onser--> vomiting
diarrhoea within 8-12 hours, production of enteroxin in the gut
42
botulism
exotoxins are produced- these are ingested in food and absorbed into bloodstream
symmetry descending flaccid msucle paralysis
43
clostridium gastroenteritis
anaerobic gram neg
spore forming
spore contaminated food or inadequately cooked food
abdo pain+ diarrhoea
44
H. pylori
gram neg spiral
person to person from contaminated food/water
dysperia, upper abdo pain, nausea, burping, bloating
45
what are the two virus' which contribute to viral diarrhoea
norovirus
rotavirus
46
norovirus
most common cause--> older children + adults
highly infectious
12-72 hours infection period
presents with nausea, abdo pain, vomiting, diarrhea
47
rotavirus
young children
1-2 day infectious period
vomiting and diarrhoea last 4-7 days
48
what are the two main groups of endoparasites
protozoa and helminths
49
what are the two main groups of helminths
nematodes(roundworms) and platyhelminths(flatworms)
50
anther name for nematodes
roundworms
51
another name for platyhelminths
flatworms
52
Malaria causes
PLAMODIUM FALCPARUM (most severe): high parastemia and extensive obstruction of capillaries
-P.vivax
-P.ovale
-P.malarie
-P.knowlesi
53
symptoms of malaria
fever like
severe anemia
respiratory distress
hypoglycaemia
54
diagnosis of malaria
1) microscopy of blood samples
2) PCR- to detect parasite DNA
3)Rapid diagnostic test
55
treatment of malaria
combination therapies with multiple drugs for treatment and prophylosis
56
prevention of malaria
cover skin with clothes and DEET
nets
residual spraying
prophylacis for travellers
57
when do clinical symptoms begin for malaria
after RBC rupture and release parasites into the peripheal circulation
58
Trichomoniasis vaginalis (protozoa)
STI mainly effects people w vagina- assymptomatic to those without (mostly)
59
Trichomoniasis vaginalis symtoms
- smelly,frothy, vaginal discharge
-cervical ulcers
-lower abdominal discomfort
-dysuria(pain on uriantion)
-dyspaneauria( pain during sex)
-predisposes to other STDs
60
dysuria
dysuria(pain on uriantion)
61
dyspaneuria
dyspaneauria( pain during sex)
62
diagnosis of trichomoniasis vaginalis
1) microscopy- direct wet mounts
vaginal fluid or urine for men
2)pap smear- swab cervix
3) rapid antigen/PCR test ( only if parasites seen by microscopy)
63
treatment of trichomoniasis vaginalis
metrnidazole
64
what is the transmission of toxoplasmosis gondii
ingestion of
-raw/ undercooked cyst-infected meat
-cat faeces( cat litter, tray, gardening, childrens sandpits, direct contact)
-contaimated food/drinking water
65
diagnosis of toxoplasmosis
serology, histology, radiology
PCR of CSF and amniotic fluid
66
treatment of toxoplasmosis
pyrimethamine, sulfadiazine
67
symptoms of toxoplasmosis
healthy and immunosupressed/ pregnant
infection of CNS and lymph nodes
healthy: resolve quickly, but usually chronic formation of cysts
flu like
rarely GIT issues to parasite
pregnant/immuno:
from acute or cysts earlier in life
severe eg. gut eye heart brain and other organs
- can lead to congenital toxoplasmosis in foetus --> foetal abnormalities( eye and brain damage, jaundice)
68
transmission of Giardisis
cysts ungested from contaimated water sources
trophozolites multiply and colonize the small bowel
cysts shed in faeces
69
symptoms of Giardisis
-watery then greasy foul-smelling stools
- abdominal pain and nausea
-bloating and flatulence
70
diagnosis of Giardisis
Microscopy of stool- direct examination of stool trophozpites
71
treatment of giardisis
-metronidazole
-tinidazole
72
prevention of giardisis
avoid water that may be contaminated
boil water 1-3 min or use a filter
good hygeine
73
Hookworm symptoms
infection of small intestine
-diarrhoea nausea and abdominal pain
-iron deficiency- ue to bleeding caused by hookworms in GIT
-fatigue
-coughing and weeezing
-itchy skin( when burrowing into feet)
74
diagnosis of hookworms
wet mount- direct microscopy of stool to detect eggs
75
treatment of hookworms
albendazole- antihelminthic drug
76
what is the life cycle of hookworms
1) egg in faeces
2) larvae hatch
3) larave penetrate skin(usually feet) and enter circulation
4) larave exit circulation in lungs- are coughed up and swallowed
5) larvae travel to and grow in small intestine
77
filariasis causes (4)
anopheles, culex, aedes, monsonia
(all mosquitos)
78
symptoms filariasis
infection of lymphatic system
-for about year (while larvae mature) assymptomatic
-after larvae have matured
lymphdenitis
eosinophillia
gradual impairment of lymphatics, dilation, stasis, chronic obstruction
lymphodema
79
diagnosis of filariasis
midnight smear- thick blood smear Giemsa stained to detect microfilarie( the microfilarie that cause lymphatic filarisis circulate in the blood at night)
- serology for filarial antigen and IgG levels
PCR
80
treatment and prevention of filariasis
avoid mosquito bites
prophylactic anti helminthic drugs
81
lifecycle of filariasis
1) infected mosquito transmits larave onto skin and larave enter the bite wound
2) larave enter lymphatic system and grow, mate and form nests, causing damage in lymph system
3) female worms produce that swarm blood at night
4) mosquito bites infected person and becomes infected
82
pinworms transmission
spread causually by ingestion or inhaling pinworm eggs
common in children (5-10 years)
83
symptoms of pinworms
infection of skin and SI
persistent anal itching and discomfort(esp at night): females migrate out of anus at night to lay eggs
84
diagnosis of pinworms
cello tape to see eggs
may see worms in faeces
85
treatment of pinworms
mebendazole- antihelminthic drug
86
cestodes symptoms
usually assymp or mild
some instestinal infections may cause anemia and malnutrition
87
what are the types of cestodes
pork tapeworms(Taenia solium)
beef tapeworm( taenia saginata)
fish tapeworm (diphyllobothrium latum)
hydatid disease - cysts (echinococcus granulosus)
88
transmission of cestodes
larvae ingested when eating undercooked or raw meat of an infected animal
89
trematodes(flukes) cause
schistomasis
induce granulomatus host immune response, leading to chronic inflammation
eg.
Schistoma haemtobium
S. japnonicum
S. mansoni
90
diagnosis of trematodes (flukes)
microscopy: eggs in stool and urine
-serology to detect antigens in urine
91
organs flukes target
intestines
liver
lungs
92
treatment of flukes
praziquantel- antihelminthic drug
93
risk factors for UTI
Female (shorter urethra, vaginal oestrogen protective)
Pregnancy (progesterone causes stasis)
Sexual activity
Obstruction
Anatomical or functional - stones, BPH, neurogenic bladder, etc.
Iatrogenic - catheter, cystoscopy, etc.
Immunocompromised (diabetes/steroids increase sugar content)
94
common pathogens of UTI
Bacteria
E coli (80%)
Staphylococcus saprophyticus a/w sexual intercourse
Klebsiella pneumoniae
Proteus mirabilis distinct fishy smell
Virus - immunocompromised
Fungus - candida
95
clinical signs of lower UTI ( half of lower ureter and bladder and lower)
Lower UTI (LUTS)
FUND: frequency, urgency, nocturia, dysuria
May lead to haematuria, suprapubic tenderness
96
clinical signs of upper UTI ( half of upper ureter to kidney)
LUTS + fever, fatigue, malaise, N/V
Flank pain, costovertebral tenderness
97
examination clinical signs of UTI
Inspection: altered conscious state (urosepsis, elderly), dehydration
Vitals: febrile and tachycardia (pyelonephritis)
Palpation: suprapubic/costovertebral angle tenderness
98
what are the 4 investigations done for UTI
1) Urinanalysis
2)Urine mCS
3) Bloods
4) Imaging
99
urine MCS UTI
Collect midstream urine (MSU) before starting ABx
First-pass urine for STI
Threshold
Significant bacteriuria: 10^5 CFU/mL
0 for suprapubic aspirate (should be sterile)
100
urinalysis
Leukocyte = pyuria
Nitrites = Gm - bacterium
Blood = non-specific, ?severe infection
High pH = urease-producing organisms (Proteus)
101
what bloods are done for UTI
WCC, CRP, blood culture (upper UTI)
Beta HCG (pregnancy)
STI screening
BGL for DM
102
what imaging is done for UTI
Indication: suspected obstruction (e.g. recurrent UTI in men), sepsis (febrile UTI)
CT abdo/pelvis (non contrast for stone, contrast for complications)
US kidneys and bladder (for hydronephrosis)
Void cystourethrography (for vesicoureteral reflux)
103
what drugs are used to treat a UTI
Antibiotics
Oral for uncomplicated, IV for complicated
Start with empirical, targeted therapy after MCS
Commonly use: nitrofurantoin, trimethoprim, augmentin, ceftriaxone
104
conservative methods of treating UTI
Behaviour: wipe front-to-back, post-coital voiding
Cranberry juice: limit UPEC colonisation
Vaginal oestrogen: for post-menopausal F
