Microbiology Flashcards
Which viruses are RNA/DNA?
Which are single or double stranded?
Most RNA viruses are single stranded
Most DNA viruses are double stranded
RNA Single:
- Hep ACDE
- HIV
- Rubella
RNA double:
- Rotavirus
DNA single:
- Parvovirus B19
DNA double:
- Hep B
- EBV
- HPV
- CMV
- VZV
- HSV 1/2
Remeber: Double standed DNA are All the Vs apart from HIV
What type of virus is HIV
Kind of RNA but not true RNA.
It is a retrovirus
Congenital CMV
How many pregnancies are affected by this?
Risk of transmission? Primary and secondary?
How many babies will have symptoms at birth?
Of those having symptoms at birth, how many will have long term effects?
What are the features of congenital CMV?
How do you diagnose it? When?
What is the incubation period of CMV?
What about breast feeding?
1 in 150 pregnancies!
Primary –> risk of transmission is 30-40%
Secondary –> risk of transmission is 1-2%
10-15% of babies will have symptoms at birth, of these, 10-15% will have long term effects.
Features:
- Visual effects
- Hearing loss (sensorineural)
- Microcephaly
- peticheal rash
- SGA
- seizures
- cerebral palsy
- Hepatosplenomegaly with jaundice
You diagnose with amniocentesis
- Cant do it until 21 weeks gestation
- Cant do it until 6 weeks after CMV infection
- 50% of mums will be seropositive
Incubation period: 3-12 weeks
Transmissable via breast milk!
Describe the bacteria in each of the following groups:
Gram Positive
- Cocci
- Bacillus
Gram negative
- Cocci
- Bacillus
Intracellular
Spiral shaped
POSITIVE Cocci (SS)
- staph
- strep
NEGATIVE (BLACC)
- Claire is obliged to be positive because she woman
- Bacillus
- Listeria
- Acinomyces
- Clostridium
- Corneybacterium
NEGATIVE Cocci GMC
- Neisseria gonorrhoea
- Neisseria meningitides
- Moraxellar catarhalis
NEGATIVE Bacillus (PHLEBS-KEPH)
- Pseudomonas
- H.influenza
- Legionella
- E.coli
- Bacteriodes
- Salmonella
- Klebsiella
- Enterobacter
- Proteus mirabilus
- Helicobacter
- - You are a PLeB if you have obliged to be negative - pseudomonas, legionella, bacteriodes
Intracellular
- Chlamydia
Spiral shaped
- treponema pallidum
- Borrelia
LISTERIA
What is the infection in pregnancy rate?
Where do people get listeria from?
What type of bacteria is it?
What is neontal death rate?
How can it affect the fetus?
What is the treatment?
It is 12/100,000
It is a gram positve bacillus
People get it fro cold meats or cheese
20-30% neonatal death rate
Can cause chorio, placenta necrosis and death
Treatment - 2 weeks anox
RUBELLA
Where is rubella from?
What type of virus is it?
What is the treatment?
What is the incubation period?
How does it affect the fetus?
Respiratory route
Togavirus. Single stranded RNA virus
No treatment. Vaccination is key but it is a live attenuated vaccine so cannot be given in pregnancy.
Incubation period - 2 weeks
Affects on fetus - cataracts, sensorineural deafness, cardiac effects.
Which congenital infection causes blueberry muffin rash?
Congenital rubella
Which is the most common congenital infection
Congenital CMV
Describe the neonatal effects for the TORCH infections
Toxoplasmosis:
- BRAIN STUFF
- Hydrocephalus
- Epilepsy
- Neurodevelopmental dealy
- Eye stuff too
Rubella:
- Blueberry muffin rash
- Heart stuff
- Cataracts
- Sensorineural deafness
CMV:
- Sensorineural deafness
- Eye stuff
- Cerebral palsy
- Jaundice with HSP
- SGA
HSV
- IUGR
- Stillbirth
- RARE
TOXOPLASMOSIS
What kind of bug is this?
Where does it come from?
What effects does it have on the baby?
How is it diagnosed?
When is infection the worst? Throughout pregnancy?
Protozoal parasite
Cats!
BRAIN STUFF and blood stuff:
- microcephaly
- Hydrocephalus
- Seizures
- Thrombocytopenia
- Anaemia
Diagnosis with PCR or Igs
Infection is the worst within first 10 weeks. However, transmission risk increases throughout pregnancy but the effects get less severe
CT: ring enhancing lesions
Tx varies ?spiromycin if fetal status unknown in terms of infection. Some other bits if known fetal infection
HSV
What type of virus is it?
When is the highest risk of HSV neonatal infection?
What are the manifestations of neonatal HSV infection? Which is the most common?
How would you manage 1/2/3 trimester primary infection of HSV
What about previous history of HSV?
Double standed DNA virus
Highest risk around delivery
Neonatal HSV types:
1. skin
2. brain
3. disseminated
70% cases are disseminated
If unsure if primary or secondary can check sero-status
Management in 1/2 trimester:
- Take 5 day course 400mg TDS aciclovir
- Take regular aciclovir from 36 weeks
Management in 3rd trimester:
- Aciclovir regulraly
- C-section
What is the treatment of GBS in labour?
3g benpen then 600mg 4 hourly until delivery
PEN ALLERGIC:
Clindamycin
What does the teenage HPV vaccine target?
Cx cancer - 16, 18, 31, 33, 45, 52, 58
Warts - 6, 11
How does HPV cause cancer?
Activates onco-proteins which are proteins that deactivate tumour supressor genes.
E6 - inactivates p53
E7 - inactivates pRb
How many HPV is cleared within 1 year?
How much HPV is cleared within 2 years?
1 year - 70%
2 years - 90%
HIV
What type of virus is it? What does it affect?
What is the vertical transmission rate in the UK?
What is the treatment?
When would someone need Zidovudine infusion?
When do you recommend a PCB
When do you check viral load?
When are fetuses checked?
- Formula feed
- Breast feed
Lentivirus (Retrovirus)
Affects CD4 T helper cells
Vertical transmission rate:
- 1.3% with cART
Zidovudine infusion:
- viral load >1000 if presenting in labour, SROM or PCB
Recommend a PCB if viral load >400
If <50 can have vaginal delivery
If 50-400 - grey area and depends on other bits
Check viral load at 36 weeks and make decision
VERY LOW RISK
- >10 weeks cART. AND
- viral load <50 x2 a month apart
LOW RISK
- viral load <50 once
HIGH RISK
- PEP
- - Doesnt meet above criteria
NO BREAST FEEDING
Formula feed
- Within 48h
- 6 weeks
- 12 weeks
- Seroconversion
Breast feed
- 2 weeks PN
- Monthly during breast feeding
- 4-8 weeks after stopping breast feeding
Which group of strep is the cause of scarlet fever and rheumatic fever
Group A strep
What bug is the most commone cause of cellulitis
strep pyogenes
What bug is the most commone cause of wound infection
Staph aureus
What bug is the most commone cause of UTI
e.coli
What type of bug causes Gangrene
Clostridia perfringens
What causes fifths disease/slapped cheek
Parvovirus B19
What are the types of necrotising faciitis?
Type 1 - polymicrobial
Type 2 - monomicrobial - strep pyogenes
What are the types of strep associated with ?
A - pyogenes - rheumatic fever, scarlet fever, toxic shock
B - chorio
C - pharyngitis/endocarditis
D (aka enterococcus) - colitis
F - liver abscess
G - toxic shock
What to do if pregnant person presents with chickenpox?
Do you give IVIG
Mild - oral aciclovir if presenting within 24h and >20 weeks
Severe - admit for IV aciclovir and >20 weeks
Can consider aciclovir if <20 weeks
Too late for IVIG if already has chickenpox. Give to women not exposed to VZV who have had a contact
What does Borellia cause
lyme disease
What is the bug causing toxoplasmosis
Toxoplasma Gondii
What is the main bug causing SSI? surgical site infections
s.aureus
What si the incubation period for:
Influenza
Scarlet fever
Parvovirus
Rubella
Chickenpox
1-3 days
1-7 days
4-20 days
14 days
14 days
Is BV gram positive or negative
Indeterminate. So if it doesnt give into about positive or negative + smelly discharge - think this!
What percentage of women develop antibodies against HPV following infection?
50%
Do STIs increase risk of HIV transmission?
Why?
Circumcision?
Yes
Basically anything inflammatory so STIs and BV
Circumcision actually lowers the risk of HIV transmission
Which virus is assciated with low grade squamous intrapithelial neoplasia? LSIL
What are they also associated with
HSV 6 and 11
Genital warts
What is the incubation period for CMV
3-12 weeks
What type of vaccine is the HPV vaccine?
Recombinant vaccine of virus-like particles
Cannot give you cancer
What is the advice regarding wound cleaning after CS?
48h sterile water
After this can shower
Sulphus granules on vaginal swab
What type of bacteria is this?
Actinomyces
It is a gram positive bacillus
BLACC
- Bacillus
- Listeria
- Actinomyces
- Clostridium
- Corneybacterium
Previous GBS but negative in this pregnancy, need abx?
YEP
Risks of getting HIV with:
Receiving Vaginal sex
Receiving Anal sex
Blood transfusion
Needle stick
0.1%
1.%
100%
0.3%
Which basteria do 3rd generation cephalosporins not act on
Listeria
Atypical (mycoplasma)
MRSA
Enterococci
What type of virus is Zika virus?
What symptoms does it cause?
What is the advice if you have travelled to a Zika prone area?
Single stranded RNA virus
Causes:
fever
rash
Dont get pregnnant if you have been to this after within 3 months
When is the risk of FETAL varicella syndrome?
What can it cause in the fetus?
When is the risk of neonatal vasicella syndrome
If gets VZV before 20 weeks gestation
up to 12 weeks - 0.4%
12-20 weeks - 2.0%
Causes:
- Limb problem
- Eye problem
- Brain problem
Infection within 5 days of delivery or 48h after
What is the commonest cause of gastroenteritis in the developed world?
What type of bacteria is this?
Campylobacter
Gram negative rod / spiral shaped
Can cause bloody watery diarrhoea
Which are the spiral shaped bacteria?
Campylobacter/helicobacter
What is endometritis usually caused by
Polymicrobial
