Microbiology Flashcards
Presentation of TB
weight loss
cough
haemoptysis
fever with night sweats
where is post primary TB found
in the upper lobes
who is affected by post primary TB
young adults
how does post primary TB heal
fibrosis and calcifications
what is the classic lesion in post primary TB
caseating granuloma
What is the Ghon focus?
multiplication of TB at pleural surface
what sort of cells are in a TB granuloma
Langhan’s giant cells
buzzword for miliary TB
rich foci
haemotological spread
First line treatment for TB
Rifampicin
Isoniazid
Pyrazinumide
Ethambutol
Give all for 2 months then R and I for another 4 months
Rifampicin side effects
orange secretions
CYP450 induction
hepatotoxic
raised transaminases
second line treatments for TB
Injectables- capreomycin, anamycin and kanamycin quinolones- moxifloxacin ethionamide/ protionamide Linelozid PAS chlofazamine
treatment of TB meningitis
RIPE for 4 months then R and I for 8-10 months
Treatment of post primary TB
RIPE for 2 months then R &I for 4 months
treatment of latent TB
8 months of isoniazid
what is mono drug resistent TB resistant to
one drug (duh)
what is MDR TB resistant to
Rifampicin and isoniazid
what is XDR TB resistent to
rifampicin
isoniazid
injectables (kanamycin and amakacin)
quinolones
imaging for TB
CXR
cultures for TB
3x cultures
broncho-alveolar lavage
EMU
lowenstein-jensen sputum sample
gold standard for TB diagnosis
pus in lowenstein jensen medium
what do you see on microscopy of TB
acid fast aerobic bacilli
waxy cell wall
investigations in TB
mantoux/ heaf test
interferon gamma assays e.g. ellispot
NAAT- PCR probes
liquid culture mediums
TB meningitis symptoms
personality change, focal neurological deficit and declining GCS
neck stiffness, headache
weight loss, malaise, fever night sweats
diagnosis of TB meningitis
tuburculotoma on head CT
lymphocytes in lumbar puncture
treatment of TB meningitis
12 months of RIPE plus steroids
extra pulmonary TB symptoms
lymphadenitis CVS: pericarditis GIT: ileitis, peritonitis GUM: renal, testes skin and liver also can be affected
risk factors for reactivating latent TB
immunosupression
aging
chronic alcohol intake
malnutrition
pathology of spinal TB
haematogenous spread of TB leading to discitis
this then leads to vertebral destruction and collapse
this can then lead to anterior extention and ileo-psoas abscess
BCG efficacy
0-80%
bad for pulmonary TB but good against leprosy, TB meningitis and disseminated TB
why is the BCG contraindicated inPLWH
-HIV –ve latent TB –> active TB 5-10% lifetime risk
-HIV +ve latent TB –> active TB 5-10% yearly risk
-
mycobacteria in leprosy
M leprae and M lepromatosis
treatment for leprosy
rifampicin
dapsone
clofazimine if multibacteria
leprosy symptoms
skin: depigmentation, plaques, macules, nodules
nerves: sensory neuropathy, thickened nerves
eyes: iridocyclitis, keratitis
bones: periositis, aseptic necrosis
tuberculoid leprosy is mediated by
Th1
lepromatous leprosy is mediated by
Th2
M Avium symptoms
in children: pharyngitis, cervical lympth adenitis
lung sx if underlying pulmonary disease
if cytoxic/ lymphoma disease then disseminated
If AIDS then disseminated multibacilliary infection with bacteraemia
M marinarum
swimming pool/ aquarium owner getsa single/ cluster of papules
Baruli ulcer (m bulurans)
a painless ulcer which progresses to a huge deformity with scarring, ulceration and contractures
how to decude if IV or oral treatment for pneumonia
CURB65 score
pathology of pneumonia
inflammation of alveoli
pathology in bronchitis
cough for most days of three months with phlegm for 2 or more consecutive years
strep pneumoniae pneumonia
sx
microscopy
gram positive diplococci
rusty brown sputum
haemophilis influenzae
microscopy and vulnerable group
associated with smoking/ COPD
gram negative coccobacillae
M catarrharis
microscopy and vulnerable group
associated with smoking
gram negative coccus
staph aureus as a cause of pneumonia
what is it associated with and what is seen on microscopy
associated with a recurrent viral infection (post flu in emq land)
gram +ve cocci (grape bunch clusters)
klebsiella pneumona
susceptible person
sx
micro
alcoholic/ elderley pt
sx: haemotysis
micro: gram negative rod, enterobacter
Atypical pneumonia microbes
legionella pneumophilia bordatella pertuccusis chlamydia psittici chlamydia pneumonia mycoplasma pneumonia TB
legionella pneumophilia
risk factors and findings
low sodium
hepatitis
risk in water towers/ air con
mycoplasma pneumonia
symptoms
test
systemic symptoms erythema multiforme, joint pain
cold agglutinin test
risk of SJS
bordella pertussis
often travelling community in EMQ
whooping cough in unvaccinated people
pathogen causing RTI in cystic fibrosis
psuedomonas aeringosa
burkholderia cepacia
pathogen causing RTI in BMT
aspergillus
CMV
pathogen causing RTI in neutropaenic patients
aspergillus spp
pathogen causing RTI in HIV patients
pneumocystitis jirovii
TB
cryptococcus neoformans
pathogen causing RTI in splenectomy patient
haemophilus influenzae
strep pneumoniae
neisseria meningitidis
which organisms do you identify with paired serum tests for pneumonia
legionella
chlamydia
if at 10 weeks
how to identify PCP on lab testing
silver staining in the cytology lab- boat shaped organisms
which pneumonias can you identify by urine antigen
legionella
strep pneumoniae
define hospital acquired pneumonia
pneumonia after >48 hours into hospital stay with no previous infection
treatment of classical community acquired pneumonia
if mild a macrolide/ amoxicillin for 5-7 days
if moderate to severe then use clarithromycin +coamxiclav/ cefuroxamine for 2-3 weeks
how to treat atypical community acquired pneumonia
use a macrolide/ tetracycline
what does clarithromycin interact with
WARFARIN
treatment of hospital acquired pneumonia
1st line: ciprofloxacin +/- vancomycin
2. piptazobactam + vancomycin
treatment of aspiraton pneumonia
metronidazole + cefuxamine
treatment of legionella pneumonia
rifampicin + macrolide
treatment of staph aureus pneumonia
flucloxacillin
treatment of pseudomonas HAP
ciprofloxacin plus gentamycin
ortazocin + piperacillin
treatment of MRSA HAP
vancomycin
Isoniazid side effects
hepatotoxicity
peripheral neuropathy
(give pyroxidine or B6)
Pyrazinamide
hyperuricaemia
hepatotoxicity
Ethambutol
visual disturbances (red-green colour blindness) optic neuritic
second line treatment of TB
1) injectables (amakacin, capreomycin, kanamycin)
Painful genital ulcers are most likely to be
Herpes
Chancroid (less likely)
Painless genital ulcers could be
Syphilis
Lymphogranuloma venereum
granuloma inguinale
What is seen on microscopy of gonorrhea
Gram negative diplococcus
What complication occurs when a baby contracts gonorrhea from mums birth canal
Ophthalmia neonatorum
The baby develops a conjunctivitis is left untreated
What happens to a patient with a complement deficiency if they contract gonorrhea
They get disseminated gonorrhea, septicaemia, arthritis and/ or rash
Gold standard diagnosis of gonorrhea
Culture from urethral swab (95% sensitive) rectal swab is 20% sensitive
Treatment of gonorrhea
200mcg of cefrtriaxone IM
or 400 mcg of oral ceftriaxone
What antibiotic is used if gonorrhea is resistant to ceftriaxone
Spectinomycin 2g im
Consequences of gonorrhea
Prostatitis or salpingitis
What is seen on microscopy of chlamydia
Intracellulaire pathogen
Ovoid and gram negative ( non spore forming)
What are the two stages of chlamydia’s life cycle
Intracellular reticular bodies that are metabolically active
Extracellular stable elementary bodies
Complications of chlamydia
PIX, ectopic risk, endometriosis
Reiters syndrome
Gold standard for chlamydia diagnosis
NAAT
Treatment of chlamydia
1g azithromycin P.O.
Alternatively 7 days100mcg BD doxycycline P.O.
Contraindicated in pregnancy ( give erythromycin 7/7 500mcg QDS )
What is lymphogranuloma venereum
Lymphatic infection with chlamydia trachomatis Serovars L1-3
syphilis on microscopy
what shape
gram positive or negative
obligate gram negative sphirochaete (helically coiled- squiggly)
use dark ground microscopy
how do you detect treponemes
PCR is gold standard
dark ground microscopy
what reagents cause a false positive on syphilis testing
cariolipin
lecathin
cholesterol
non treponomal tests for syphilis
useful in primary infection and to check the treatment response
detect non-specific antigens
VDRL slide test
treponomal tests for syphilis
these test specific antigens for t. pallidum
Enzyme immuno-assay (EIA)
flourescant treponemal antibody (FTA)
T. pallidum haemagglutinin test (TPHT)
pros and cons of treponemal tests for syphilis
it is more sensitive than non-treponemal tests
the results stay positive for years despite effective treatment
appearance of primary syphilis infection
macule –> papule
–>painless lump that appears 1-12 weeks after infection and persists for 4-6 weeks.
Serous exudate with clean base
regional adenopathy
symptoms of secondary syphilis
general: malaise, low grade fever
derm: symmetrical non-pruritic maculopapular rash on back, trunk, palms, soles, trunk, face, arms, legs
genital: genital ulcers
mouth: snail track ulcers, mucosal lesions
eyes: uveitis, choroidoretinitis
alopecia
neuro: aseptic meningitis, cranial nerve palsies, acute nerve deafness, optic neuritis
when do symptoms of secondary syphilis occur
1-6 months after infection
tertiary syphilis
cardio: aortitis
granuloma
meningitis: “pariesis of the insane”,
tabes dorsalis: degeneration of the dorsal columns resulting in hyporeflexia, loss of proprioception and sensation and therefore causes ataxia
treatment of syphilis
single dose IM penecillin (doxycyclin if allergic)
what is the jarisch-heimer reaction
(fever, headache, myalgia, sometimes exacerbation of
syphilitic symptoms) – common, develops within hours of syphilis abx administration and clears within 24hrs.
congenital syphilis
occurs during birth/ pregnancy hepatosplenomegaly rash neurosyphilis fever pneumonitis
what pathogen causes chancroid
haemophilus ducreyi
what are the symptoms of chancroid
multiple painful ulcers
often in african tropical countries
what will be seen on microscopy of chancroid
gram negative cocco-bacillus
how do you diagnose chancroid
PCR
culture on chocolate agar
what pathogens are contracted from oral-anal contact
shigella, salmonella, giardia
trichomonias infection symptoms
urethritis in men
discharge in women
strawberry cervix
what pathogen causes trichomoniasis
T. vaginalis
how is trichomoniasis diagnosed
wet prep microscopy
how is trichomoniasis treated
metronidazole
what is the abnormality in bacterial vaginosis
reduced lactobacilli
polymicrobial
abnormal vaginal flora
how to diagnose BV
gram stain the discharge
positive whiff test
candidiasis symptoms
cottage cheese discharge: thick white discharge with itching, soreness and skin breaking
balanitis in men
vulvo-vaginitis in women
mollascum contagiosum
spread by touch/ sexual contact
dsDNA pox virus
huge lesions if immunocompromised, assume HIV until proved otherwise
genital warts pathogen
HPV virus usually strains 6 and 11 which ARE NOT associated with cervical cancer
dsDNA
(16, 18 is increased risk of cervical dysplasia, though the quad vaccine does protect against all 4 strains)
incubation time and appearance of genital warts
3 weeks to 8 months
can be keratinised, pedunculated, planar, carpeted, pigmented or papular
viral STIs
HAV, HBV,HCV (usually HIV+ MSM)
HIV
HSV
Examples of disease from tinea infection
ringworm
athletes foot
diseases from pyteriasis
t versicolour
sebhorreic dermatitis
how to test for candida
culture: mannan
antibodies
how to test for aspergillus
PCR
ELISA
beta glucan test
grows on czapek dox agar
how to test for cryptococcus
cryptococcal antibodies in serum/ CSF
india ink staining
example of a polyene
what do they target
give e.g. of organism affected
amphotericin
cell wall integrity
yeast
example of an azole
what do they target
give e.g. of organism affected
fluconazole
cell membrane synthesis
yeast
Terbinafine
what do they target
give e.g. of organism affected
targets cell membrane
against dermaphytes/ mould
what does flucytosine do
targets DNA synthesis in fungal infection
echinocandin
against yeast
targets cell membrane
e.g. capsofungin
what is used to treat cryptococcal meningitis/ invasive fungal disease
amphotericin B
what are the types of PUO
classical
healthcare associated
neutropenic
HIV assocaited
causes of classical PUO
infection returning traveller neoplasm malignancy genetic
causes of healthcare acquired PUO
c diff
immobilisation
surgical lines
drugs: vancomycin, penecillin, serotonergics
causes of neutropaenic PUO
GVHD chemo haematological malignancy mycobacteria drug fever
causes of HIV associated PUO
seroconversion TB kaposis sarcoma PCP cryptococcus lymphoma histoplasmosis
what to screen for in PUO
vasculitis: cANCA, pCANCA
genetics: fabry’s, FMF, cyclic neutropenia
Bence jone proteins
casts i nurine
differentials for fever in a returning traveller
malaria dengue typhoid rickettsia brucella viral haemmorhagic fever e.g. lassa/ ebola
typhoid bacteria type
gram negative bacillus
typhoid pathogen
salmonella typhi
salmonella paratyphi
what is the infection in typhid
enteric fever infecting peyers patches
how is typhoid fever transmitted
water and food
symptom of typhoid
ROSE SPOTS RELATIVE BRADYCARDIA hepatosplenomegaly abdo pain and diarrhoea/ constipation fever headache
consequences of chronically carrying typhoid
gallstones
immunospression
diagnosis of typhoid
stool culture
blood test
is typhoid a notifiable disease
yes
what the the subtypes of malaria
p falciparum
p vivax
p ovale
p malariae
which is the severe type of malaria
p falciparum
what is the common type of malaria
p vivax
what is the benign type of malaria
p malariae
what is seen on blood film of p falciparum
immature ring trophozoites/ mature trophozoites and schizont
crescent shaped gametocytes
how is p falciparum treated
quinine + doxycyclin/ clindamycin/
riamet (artemether/ lumefantrine)/
malarone
what is seen on blood film of p vivax
schuffner dots
>20 merozoites. schizont
what is seen on blood film of p ovale
schuffner dots
how is p ovale treated
chloroqiune then primaquine
how is p vivax treated
chloroquine then primaquine
what is a thick film used for in malaria
to discover parasitaemia
what is the thin film used for in malaria
to determine species
blood findings in p falciparum malaria
wcc normal
reduced platelets
deranged LFTs
anaemia
symptoms of malaria
fever/ rigors
flu like disease- myalgia, headache
N&V
splenomegaly
may have focal neurology- reduced gcs or shock
rarely dark urine- diarrhoea, abdo cramps
when is parenteral therapy indicated i p falciparum
parasitaemia>2%, pregnancy, comiting
what GI infections are caused by anaerobes
clostridium (difficicle, perfringens and botulinium)
what are the symptoms of c. botulinum
descending paralysis
pathology of c bolutlinum
preformed toxin blocks ach release from peripheral nerves
treatment of c botulinum
antitoxin
clostriium perfringens pathology
superantigen enterotoxin binds to MHC/ TCR
massive cytokine production and supression of immune response
where does clostridium perfringens act
small bowel
incubation period of clostridium perfringens
8-16 hours
symptoms of clostridium perfringens
watery diarrhoea and cramps
risk of gas gangrene
symptoms of c difficile infection
pseudomembranous colitis
what abx cause c diff infection
flouroquinolones or cephalosorins
treatment of c diff
metronidazole
PO vancomycin
gram negative lactose fermenting gi infection
e coli
subtypes of e coli
ETC
EIEC
HIS
EPEC
ETEC
travellors diarrhoea
EIEC
invasive dysentary
EPEC
infantile diarrhoea
treatment of ecoli
ciprofloxacin
no lactose fermenting git infections
salmonella
shigella
yersina enterocoli
enteritides
enteritides symptoms
self limited non blood diarrhoea
treatment of enteritides
ceftriaxone or ciprofloxacin
shigella symptoms
fever
pain
bloody diarhorrea
pathology of shigella
affects distal ileum and colon
shiga enterotoxin
yersinia enterocolitis pathology
mesenteric adenitis with necrotising granulomas
association sof yersinia
erythema nodosum
reactive arthritis
what are the characteristics of vibriosis
late lactose femeneters
oxidase positive
gram negative
campylobacter jejuni microscopy
gram negative
s shaped
oxidase positive
campylobacter symptoms
prodrome of headache and fever
abdo cramps
foul smelling diarrhoea
treatment of campylobacter
erythromycin
causes of campylobacter
drinking unpasturised milk
listeria monocytogenes
V/L shaped
tumbling motility
beta haemolytic
aesulin positive
symptoms of listeria
watery diarrhoea cramps headache fever little vomiting febrile gastroenteritis
entamoeboeba histolytica
MSM
non motile cyst in diarrhoeal illness
flask shaped ulcer on histology
symptoms of entamoeba histolytica
dysentery, wind, tenesmus, wt loss
RUQ pain and liver abscess
giardia lamblia buzzwords
hikers/ trvellers/ MSM/ mental hospitals
pathology of giardia lamblia
pear shaped trophozoites- 2 nuclei
trophozoites in stool
symptoms of giardia lamblia
malabsorptio nof protein and far- foul smelling non bloody diarrhoea
treatment of giardia lamblia
metronidazole
cyptosporidium parvum
severe diarrhoea in immunocompromised
oocytes in stool
treatment of cryptosporidium parvum
paromycin
viruses causing secretory diarrhoea
rotavirus adenovirus norovirus poliovirus enterovirus hep A
Examples of HAI
C diff
E. coli (UTI)
MRSA causing bacteraemia
Predisposing factors to C diff infection
The three c’s
Cephalosporins, clindomycin and ciprofloxacin
How is Ecoli resistant in HAI
Extended spectrum beta lactamases
What organisms other than ecoli can be responsible for HAI UTI
Klebsiella
Proteus
Pseudomonas
Which chromosome is the prion gene on
Chr 20
What pathogens could cause a surgical site infection
Coagulase negative staph
MRSA
What pathogens could be responsible for hospital acquired infection resulting in bacteraemia
MRSA
Coagulase negative staph
E. coli
Differentials in a prion disease patient
Huntington’s
Spinocerebellar ataxia
What is the difference between PrP and PrPsc (prion structure)
Alpha helix to beta plateau sheet
No longer broken down by protease or radiation
What genetic polymorphism is associated with prion disease
Codon 129 MM/ MV/VV
Treatment of CJD symptoms
Clonazapam for myoclonus
Quinacrine, pentosan and tetracycline to delay prion conversion
EEG findings in CJD
Triphasic spikes
CSF analysisin sporadic CJD
14-3-3 protein positive
What is seen in post mortem of sporadic CJD patients
Spongiform vaccuolation
PrP amyloid plaques
Where in the brain does sporadic CJDaffect
Most areas normal except basal ganglia
What are the EEG changes in variant CJD
Non specific slow waves
Where does variant CJD affect the brain
Thalamus
Is 14-3-3 protein normal in variant CJD
Sometimes
What genetics are common in variant CJD
All sufferers are 129MM homozygotes
What is seen on western blot in variant CJD
Tonsillitis biopsy shows type 4t PrPsc
What is seen on post mortem of variant CJD
PrPsc 4t in CNS and lymphoreticular tissue
Florid plaques
Sporadic CJD causes
PRNP mutation or spontaneous conversion of PrP to PRPsc
Symptoms of sporadic CJD
Rapid progressive dementia
Cortical blindness
Akinetic mutism
Lower motor neurone signs
Survival time for sporadic CJD
6 months
Causes of acquired CJD
BSE- vCJD
Iatrogenic
Kuru
vCJD age of onset
30s so younger than sCJD
VCJD symptoms
Psychiatric symptoms e.g. paranoia followed by neuro signs e.g. peripheral sensory loss, ataxia and myoclonus then finally chorea and dementia
Causes of vCJD
Bovine spongiform encephalopathy
Symptoms of iatrogenic CJD
Ataxia
Eventually dementia and myoclonus
Kuru symptoms
Progressive cerebellar syndrome
45 year incubation period then 2 years of disease then death
Causes of kuru
Cannibalism
Inheritance of GSS
Autosomal dominant
Symptoms of GSS
Dysarthria then cerebellar ataxia then dementia
FFI symptoms
insomnia and paranoia then weight loss then mutism
How is FFI inherited
Autosomal dominant
Zoonoses: mice
Hantan virus Lyme borreliosis Ehrlichia Bartonella Lymphatic choriomeningitis
Rat zoonoses
Rabies Leptospirosis Lassa fever Hantan virus Plague Haverhill (rat bite ) fever Pasteruellosis
Cat zoonoses
Bartonellosis (cat scratch) Leptospirosis Q fever Toxoplasmosis Rabies Ringworm Toro arias is
Small ruminants
Anthrax Toxoplasmosis Brucellosis Q fever Cryptosporidium
Dog zoonoses
Hydatid disease Leptospirosis Brucellosis rabies MRSA Ring worm Toxocariasis
Zoonoses cattle
Anthrax Leptospirosis Brucellosis Bovine TB Toxoplasmosis Ring worm E. coli
Swine zoonoses
Influenza A Cystericercosis Brucellosis Leptospirosis Erysipeloid
Bird zoonoses
Psittacosis Influenza Cryptococcus Influenza A Salmonella from poultry west Nile fever
Water sports associated zoonoses
Leptospirosis HAV Giardia Toxoplasmosis Mycobacterium marinos/ ulcerans Burkholderia pseudomallei E. coli
Water bornezoonoses
Campylobacter
Salmonella
VTEC
Cryptosporidium
Food associated zoonoses
Listeria Tania Cysticercosis Toxoplasmosis Trichonellosis Yersiniosis Giardia
Definition of zoonoses
Disease and infection which are transmitted naturally between humans and other vertebrates
Brucellosis pathogen
Gram negative aerobic bacillia
How is brucellosis transmitted
Inhalation or skin/ membrane contact
Eating contaminated food (untreated dairy)
Symptoms of brucellosis
Incubation period of 3 weeks Then undulant fever that is bad at night but normal by morning Malaise Rigours Fatigue Myalgia
Signs of brucellosis
Arthritis Spinal tenderness Lymphadenopathy Splenomegaly Hepatomegaly Epidemiologists-orchid is
Investigations in brucellosis
WCC normal
Anti O polysaccharide antibody >1/160
May be neutropaenic
Treatment of brucellosis
Streptomycin with either tetracycline or doxycycline for 4-6 weeks
Otherwise oral doxy and rifampicin for 8 weeks
Which virus causes rabies
Rhabdovirus
What is pathognomic of rabies
Negri bodies
Severe complication of rabies
Encephalitis
Symptoms of rabies
Fever
Headache
Sore throat
Acute encephalitis
How to diagnose rabies
ELISA test for IgM
IFA for rabies antigen in brain tissue
Treatment of rabies
IgG
What pathogen causes the plague
Yersinia pestis
What type of pathogen is yersinia pestis
Gram negative lactose fermenter
How to diagnose plague
PCR
What are the subtypes of yersinia pestis plague
Bubonic
Pneumonic
Symptoms of bubonic plague
Dry gangrene
Swollen lymph nodes
How are the different plagues spread
Bubonic- flea bite
Pneumonic- person to person contact
Plague treatments
Streptomycin
Doxycycline
Gentamicin
Chloramphicol
Leptospirosis pathogen
L interrogans
Obligate
Gram negative
Aerobic motile spirochaetes
How is leptospirosis transmitted
Dog/ cat urine and when swimming in infected water it penetrates broken skin
Symptoms of leptospirosis
High spiking temp Headache Conjunctival haemorrhages Jaundice Malaise haemolytic anaemia, renal failure,c arditis, meningism
Incubation of leptospirosis
10-14 days
Treatment of leptospirosis
Amoxicillin
Erythromycin
Doxycycline
Ampicillin
Anthrax pathogen
Bacillus anthracite
What are the subtypes of anthrax
Cutaneous and pulmonary
What is cutaneous anthrax
Painless round black lesions with a ring of oedema
What is pulmonary anthrax
Woolsorters disease Massive lymphadenopathy Mediastinal haemorrhage Pleural effusion Resp failure
What pathogen causes Lyme disease
Bordelaise burdoferi
What are the stages of Lyme disease and what happens in each one
Early localised: bullseye rash, cyclical fever, flu like sx
Early disseminated: malaise, lymphadenopathy, hepatitis, carditis, arthritis
Late persistent: arthritis, focal neurology, neuropsych disturbance, acrodermitis chronic atrophicans
How to diagnose Lyme disease
Biopsy edge of erythema chronicum migrans (bulls eye rash)
ELISA for lyme antibodies
Treatment o Lyme disease
Doxycycline for 2-3 weeks
If CNS problems also IV ceftriaxone for 2-4 weeks
Complication associated with Lyme disease
ME
Q fever pathogen
Coxiella burnetii
Presentation of Q fever
Atypical pneumonia
DRY Cough, fatigue, pleural effusion and diarrhoea
Treatment of Q fever
Doxycycline
Types of leishmaniasis
Cutaneous-L major, L tropica
Diffuse cutaneous:
Mucocutaneous: L Brazilians is
Visceral (kala afar): L infantum, L Donovani, L chagasi in south america
Cutaneous leishmania
L major and L tropica
Transmitted by sandfly bite
Pathogenesis of cutaneous leishmania
Bit ulcerated as dermal macrophages multiply
After one yearheals and leaves a depigmented scar
Single or multiple painless nodules
Type IV reaction
Diffuse cutaneous leishmania
Modular non ulcerting lesions on nose
Who gets diffuse cutaneous leishmania
Immunocompromised patients
Therefore the skin test is negative
Mucocutaneous lieshamania
L Braziliensis
Dermal ulcer like cutaneous leishmaniasis and years later ulcers in nasal mucosa
Visceral leishmania
L donovani, L infantum, L chagasi
Abdo discomfort, weight loss and distension in malnourished child
Complication of visceral leishmania caused by L donovani
PKDL
The reticulo-endothelial system is invaded causes hepatosplenomegaly
BM invasion
3 antigenic variants of flu in human
Influenza A (H1)- January Influenza A (H1N1)=December Influenza B
Flu vaccine is fractioinsof HA and NA to combat
What sort of vaccine is flu vaccine
Inactivated
Bird flu- natural reservoir and serotonin
Ducks
H5N1
How does neuramidase increase flu infection
Cleaves sialic acid residues exposing receptors on host cell
Disrupts mucin barrier
How does haemagglutinin increase flu transmission
Binds sialicacid receptors and enables virus entry
Endosomal-viral envelope fusion and release
What is antigenic drift re: flu
New strains of virus because of HA/ NA mutations
What is antigenic shift
Complete change of HA/ NA and trading of RNA segments between human and virus
Only in influenza A
What causes the huge tropism for influenza A
Cleavage by Clara tryptase inthe lung
What is an antiviral for influenza A
Amantadine
Targets M2 ion channel
Is amandine effective against influenza A
No AA mutation in M2 means many flu is resistant
What are the neuramidase inhibitors for influenza
Tamiflu
Relenza
Sialic acid
Need to be given in 48 hours of infection
What does acyclovir do
Treatment for herpes
Prevents HSV thymidine kinase from being activated and so prevents viral DNA extension
What are symptoms CMV infection
RCHEP Retinitis Colitis Hepatitis Encephalitis Pneumonitis
Owls eye inclusions in CMV cells
How is CMV treated
Gangyclovir - risk of marrow toxicity
Foscarnet is second line - nephrotoxic
Cidofivir is third line- nephrotoxic
How does gangcycloivr work
Nucleoside analogue
How does foscarnet work
Pyrophosphate analgue
Inhibits nuclei acid synthesis and doesn’t need activation
How does cidofivir work
Nucleoside phophonate
Used for CMV retinitis
What needs to be given alongside foscarnet or cidofivir
Probenecid because they are nephrotoxic
When do you treat VZV
If immunosuppressive, pregnant or have pneumonitis as an adult
Act Very Fast with herpes- what are these meds
Acyclovir
Valaciclovir
Famciclovir
When do you treat HBV
If HBV DNA levels are greater than 2000
When serum ALT rises
When liver biopsy shows moderate active disease
How do you treat HBV
Peginterferon 2alpha (sc)
Tenofovir
Entecavir
What is the aim. Of HBV treatment
Prevent conversion to HCC or cirrhosis
Normalise ALT
Maintain serum HBV DNA
Treatment options for HBV
Peginterferon
Nucleoside analogues
Nucleotide analogues
HCV treatment goal
Persistent absence of HCV 6 months after treatment
Prevent progression to cirrhosis
Treatment of HCV
Peginterferon alpha 2b/2c
Nucleoside analogues e.g. ribivarin
Side effects of ribivrin (nucleoside inhibitor for HCV)
Haemolytic anaemia
What genotypes are more likely to benefit for HCV treatment
Genotypes 2 and 3
Genotypes 1,4,5,6 tend to have less successful treatment
Influenza treatments: NA inhibitors
Oseltamavir
Zanamivir
Amantadine
RSV/ parainfluenza treatment
Ribivarin— guanasine alalogue
Stages of PCR
1) denature
2) primer annealing
3) chain elongation with Taq polymerase
Three cause of post transplant viral infection and examples
- Reactivation of latent infection e.g. herpes
- Graft brought infection with it e.g. Hep B
- Exogenous opportunistic infection post transplant e.g. measles
Where do herpes and VZV stay latent
Neurones
Where do EBV and CMV stay latent
Leukocytes
What are complications of VZV in the immunocompromised
Pneumonitis
Hepatitis
How to prevent varicella infection
Varicella zoster Ig
Treatment of VZV
Acyclovir
How to treat EBV after BMT
Rituximab and reduce immunosuppressive
What does HHV 8 causes
Castleman’s disease
Kaposi’s sarcoma
How is kaposi’s sarcoma diagnosed
Spindle cells
KSHV proteins on biopsy
What does HHV6 do
Causes graft rejection
Symptoms similar to CMV
How is HHV6 treated
Gangcyclovir
Foscarnet
Cidofovir
Who gets adenovirus
Paediatric outpatients after BMT
How is adenovirus treated i n paediatric patients after BMT
Ribivarin
Reduce immunosupression
Complications of measles
Giant cell pneumonia
Encephalitis
How to treat measles
Supportive
Normal human Ig
What pathogens colonise the surgical site and cause infection
Staph aureus, pseudomonas, E. coli and haemolytic strep
How is surgical site infection treated
Flucloxacillin
RF of septic arthritis
Immunosupression
Abnormal joint
Bacteraemia
Bugs causing septic arthritis
Staph aureus,
Strep
Gram negatives e.g. E. coli rarely
What’s the underlying pathology in septic arthritis
Bug adheres to synovial membranes and proliferates in fluid
Symptoms of septic arthritis
Unwell febrile patient with a hot swollen joint
How to diagnose septic arthritis
Blood culture before ABX
Joint aspirate (>50 000 cells/ mm3)
Imaging shows effusion
inflammatory markers
Treatment of septic arthritis
IV cephalosporin or flucloxacillin
If MRSA vancomycin
Drain joint
What is the pathogenesis of osteomyelitis
Subacute (Brodie) abscess to frank osteomyelitis
Local or haematological spread
Bugs causing osteomyelitis
Staph aureus
How to diagnose osteomyelitis
MRI
Biopsy bone
Symptoms of osteomyelitis
Pain
Fever
Local swelling
How to treat osteomyelitis
Abx
Second line: debridment
Pathogens causing prosthetic joint infection
Staph aureus
Enterobacteriae
Symptoms of prosthetic joint infection
Failure of joint
Pain
Loosening on radiology
Diagnosis of prosthetic joint infection
Joint aspiration
Loosening on radiology
Treatment of prosthetic joint infection
Remove metalwork- revise joint
Abximpregnated cement
Treatment of pyelonephritis
Coamoxiclav+ gentamicin
Cefuroxime + gentamicin
Antimicrobials that inhibit cell wall synthesis
Beta lactams
Glycopeptides
Examples of beta lactams
Cephalosporins
Carbapenems
Penecillins
Example of a cephalosporins
Ceftriaxone
Example of a carbapenem
Meropenem
Example of glycopeptide
Vancomycin
Abx that inhibit protein synthesis
Aminoglycosides Tetracyclines Macro lines Chloramphenicol Oxazolidinones
When are aminoglycosides used and give an e.g
Gram negative sepsis
Gentamicin
When are tetracyclines used and give an e.g.
Intracellular chlamydia
Doxycycline
When are macrolides used and give an example
Gram positive organisms if there is a penicillin allergy
Eg of macrolide
Erythromycin
When is chloramphicil used
Bacterial conjunctivitis
When are oxazolidonones used andgive e.g.
Gram positive, MRSA positive VRE
Linezolid
Antibiotics that inhibit DNA synthesis
Flouroquinolones
Nitroimidazoles
When are flouroquinolones used
Gram negative
Ciprofloxacin
When are nitroimadazoles used and give e.g.
Anaerobes and Protozoa
Metronidazole
Abx that inhibit RNA synthesis
Rifamycin
When are rifamycins used and giv e e.g.
TB
Rifampicin
What abx target cell membrane toxins
Polymyxin
Cyclic lipopeptide
When are polymyxins used and what do they target
Gram negatives
Colistin
What do cyclic lipopeptides target and give e.g.
gram positive MRSA positive VRE
Daptomycin
What abx inhibit phosphate metabolism
Sulphonamides
Diaminopyramidines
When are sulphonamides used and give e.g.
PCP with trimethoprim
Sulphamethoxazole
When are diaminopyramidines used and give .e.g
UTI
Trimethoprim
Which abx are broad spectrum
Co-amoxiclav
Tazocin
Ciprofloxacin
Meropenem
Narrow spectrum abx
Gentamicin
Flucloxacillin
Metronidazole
4 mechanisms of antibiotic resistance
Bypass abx sensitive step (MRSA)
Enzyme mediated drug inactivation (beta lamases)
Impairment of accumulation of drug (tetracycline resistance)
Modification of drug target in microbe (quinolone resistance)
Acronym for abx resistance
BEAT
Pathogen and abx inskin infection
Staph aureus
Flucloxacillin
Pathogen and abx in pharyngitis
Beta haemolytic streptococcus
Benzylpenecillin
Community acquired pneumonia abx if mild
Amoxicillin
Sever community acquired pneumonia abx
Co-amoxiclav + clarithromycin
Hospital acquired pneumonia abx
Amoxicillin + gentamicin
/ tazocin
Abx and pathogen for bacterial meningitis
Meningococcus/ streptococcus
Ceftriaxone unlessits likely to be listeria induced in which case amox
Abx for UTI
Trimethoprim/ nitrofurantoin
Abx for nosocomial UTI
Co-amoxiclav/ cephalexin
Abx for severe sepsis
Tazocin/ ceftriaxone
Metronidazole+ gentamicin
Abx for neutropaenic sepsis
Tazocin + gentamicin
Pathogen and abx for colitis
C. difficile
Stop ceph and start PO metronidazole
Congenital infections (TORCH)
Toxoplasmosis Other (HIV/ HBV) Rubella CMV HSV
Sx of congenital infection (TORCH)
Thrombocytopenia Other- ears/ eyes e.g. cataracts, choroidoretinitis Rash Cerebral anomaly e.g microcephaly Hepatosplenomegaly
When do neonatal infections present
<6 weeks
What causes neonatal infection
Group B strep
E. coli
Listeria
How to prevent congenital infections
TORCH screen
Symptoms of neonatal infection
Fever
Meningitis
Diagnosis of neonatal infection
Septic screen FBC CRP Blood culture Deep ear swab CSF Surface swab CXR
Treatmetn of early onset sepsis in the neonate
Supportive
Benpen + gentamicin (unless listeria in which case use amox/ ampicillin)
Diagnosis of late onset neonatal sepsis
Septic screen plus urine
Causesof late onset sepsis in the neonate
Coagulase negative staph
GBS
Ecoli
Listeria
Sx of late onset neonatal sepsis
Bradycardia Apnoea Poor feeding Irritability Convulsions Jaundice Resp distress Focal inflammation e.g.umbilicus
Abx in late onset neonatal sepsis
- benzylpenecillin plus gentamicin
- Tazocin + vancomycin if v ill
If community amox plus cefotaxime
Common causes of childhood infections
VZV
HSV
Bacterial infection
Causes of paeds bacterial meningitis by age
1-3 months GBS, E. coli, listeria
<3months haemophilia influenza’s
>3 months- neisseria meningitidus
<2 years strep pneumoniae
Paeds causes of RTIs
Virus
S pneumoniae
Mycoplasma
Causes of UTI in paeds and sx
E. coli, proteus, klebsiella, enterococcus
Pyuria and clinical sx
>10^5 Cafu/ ml
Fungal cause of meningitis
Cryptococcus
Viral causes of meningitis
Coxackie
HSV2
Echovirus
Mumps
How does bacterial meningitis spread
Systemic from mucosa or local from skull fracture
Risk factors for bacterial meningitis
Complement deficiency
Hyposplenism
Immune defect
RF for strep pneumoniae meningitis
Fractured skull - esp if CSF leak
How to diagnose meningitis
Blood cultures
Serum AG
EDTA-PCR
Throat swab
Clinical suspicion
Management of bacterial meningitis
Resuscitate- ceftriaxone and corticosteroids
Cover listeria with ampicillin and encephalitis with IV acyclovir
Hepatitis A Ig
IgG if vaccinated/ prev infecction
acutely IgM
How long do anti hep A IgM antibodies persist for
14 weeks
What type of virus is hep A
RNA
What type of virus is hep B
DsDNA
Method of hep Btransmission
Sexual, vertical, horizontal
Signs for diagnosing hep B infection
Very high ALT and high AST
HBsAg for infection/ vaccine
HBeAg for infectivity
HBcAb for exposure
Treatment of hep B
Lamivudine
Tenofivir
Peginterferon alpha 2a
Consequences of hep b infection
HCC
Cirrhosis
Fibrosis
Polyarteritis nodosa
What type of virus is hep C
RNA
How is hep C transmitted
Blood products
How to diagnose HCV infection
ALT
Anti HCV
Treatment of HCV infection
Peginterferon alpha 2b
Ribivarin
Consequences of HCV infection
Cirrhosis
Cyroglobin antibodies- glomerulonephritis
Hepatitis D
Only infects those with hep b
Hep E
Faecooral route in India
Common viral infections in pregnancy
Rubella
Influenza
Measles
Parvovirus B19
Parvovirus B19 in pregnancy risks
3% risk of hydrous fatalis
IF >20 weeeks no risk
Parvovirus B19 symptoms
Fever
Malaise
Slapped cheek- erythema infectious
Transient aplastic crisis
Transmission of parvovirus B19
Resp/ blood borne
6-8 days incubation
Symptoms of rubella in mum
Flu like symptoms
Pinpoint maculopapular rash
Lymphadenopathy
How to diagnose maternal rubella
Serology of saliva swabs
Implications of rubella on foetus
Congenital rubella syndrome
What is congenital rubella syndrome
If infected before 8 weeks- risk of spontaneous abortion (20 %)
Cataracts Glaucoma Retinopathy Deafnesss Mental retardation Heart disease Splenomegaly Meningoencephalitis
Risks of influenza in pregnancy
5x still birth
3x preterm delivery
Implication of measles while pregnant
IUD/ miscarriage
Pre term delivery
Increased maternal morbidity
Types of vaccination
Live attenuated Inactivated Recombinant proteins Conjugated Subunit
E.g. of live attenuated vaccine
MMR
VZV
Yellow fever
E.g. of inactivated vaccine
HAV
Rabies
E.g. of recombinant protein vaccine
HBV
E.g. of subunit vaccines
Influenza
Typhoid
E.g. of conjugate vaccine
Meningitis c
Clinical spectrum of leprosy
TT BT BB BL LL
What is TT leprosy
Tuberculoid
Th1 mediated
Depigmented lesions
What is B.B. leprosy
Borderline
Multiple plaques
What is LL leprosy
Lepromatous
Th2 mediated, multibacilliary
Neuropathic ulcers
What does BT leprosy cause
Nerve damage
granuloma inguinale another name
donovanosis
symptoms of donovanosis
papule or nodule that breaks down into large expanding ulcers
appearance of donovanosis ulcers
beefy red appearance
how to diagnose donovanosis
giemsa stain of biopsy/ tissue crush
donovan bodies seen
treatment of donovanosis
azithromycin
LGV first stage
painless ulcer that develops 2-12 days after exposure
also balanitis, proctitis, cervicitis
second stage of LGV
iunilateral painful inguinal buboes, fever , malaise and rarely meningoencephalitis
proctocolitis and hyperplasia of lymphoid tissue
late LGV sx
strictures, lymphadenopathy, abscess, frozen pelvis, genital elephantiasis
LGV treatment
21/7 doxycycline BD
or erythromycin 21/7 QDS 500mg/ azithromycin 1g once weekly for 3 weeks
STI:: oral anal pathogens
shigella
salmonella
giardia
treatment of genital warts
- podophyllotoxin home treatment (CI in pregnancy)
2. cryotherapy/ imiquimod
symptoms of T versicolour
depigmentation in those with darker skin
ptyriasis: malassezia globosur/ furfur
ptyriasis fungus
malassazia globosa/ furfur
candidaalbicans treatment
fluconazole
treatment of invasive fungal disease from candida
amphotericin-B
treatment of aspergillus
voriconazole
what vector is cryptococcus associated with
birds (pigeons)
HIV
treatment of cryptococcus
2/52 amphotericin B +/- flucytocine
congenital CMV symptoms
IUGR jaundice hepatosplenomegaly thrombocytopenia impaired IQ sensorineural deafness microcephaly cytomegalic inclusion disease
how to diagnose CMV
paul bunnel test
serology: IgG and IgM
cell culture in human fibroblasts- owls eye inclusions
roseola virus
roseola infantatum (exanthum subitum, sixth disease) 3/7 fever then transient rash
where is roseola virus latent
lymphocytes
treatment of roseola virus reactivation after BMT immunospression
gangcyclovir
foscarnet
cidofivir
gential herpes symptoms
fever dysuria malaise painful vesicular rash sacral radiculomyeltis (self limiting urinary retention)
oral herpes symptoms
painful rash with erythematous base- coalesce
submandicular lymphadenopathy
fever
differential for oral herpes
herpangina (coxackie A)
symptoms of herpes encephalitis if HSV 1
2 week flu like prodrome
focal neurology and personality change
seizures
coma/ death
symptoms of herpes encephalitis if HSV 2
mollarets meningitis
recurrent aswptic meningitis
CSF findings in herpes encephalitis
lymphocytic pleiocytosis
normal glucose
raised protein
MRI/ CT findings in herpes encephalitis
front- temporal or parietal lobe lesions
tx of herpes encephalitis
dont wait for test results
10mg/kg IV acyclovir STAT TDS then switch to three weeks of oral acyclovir
herpes skin manifestations
scrum pox- herpes gladiatorum (painful blister and inguinal LN) herpetic whitlow- painful red finger erythema multiforme eczema herpeticum zosteriform HS HS dermitits
neonatal herpes
foetal loss
skine/ eye/ mouth lesions with LT sequelae
diseeminated disease and bvesicles 10 days post partum - multi organ failure/ fulminant hepatitis
neuroloigcal consequences
treatment of neonatal herpes
oral/ IV acyclovir 6 weeks before EDD
VZV cytology findings
tzanck cells (multinucleated giant cells)
symptoms of VZV
vesicular rash- dew on a rose petal
fever malaise headache
rash scabs after a week
complications of VZV
ramsey hunt syndrome pneumonitis/ scarring/ reyes syndrome guillian barre geniculate ganglion of CN VII- hearing loss and vertigo post herpetic neuralgia
VZV in pregnancy causes
congenital varicella syndrome
implicationso fcongenital varicellar syndrome
scarring hypoplastic limbs cortical atrophy psychomotor retardation chorioretinitis cataracts disseminated disease 7 days after delivery
treatment of VZV in pregnancy
VZIG
VZV in adulthood treatment
anyone at risk 800mg acyclovir
PO TDS 7/7
shingles
dermotomal painful rash
treatment of shingles
800mg acyclovir PO 5 times daily
topical eye drops
only if <24 hours of rash
glandular fever sx
triad of fever, pharyngitis, lymphadenopathy and a maculopapular rash
how to diagnose glandular fever
blood film
monospot agglutination
EBV antibodies
Paul bunnell test
ocular herpes
PORN
acute retinal necrosis if immuncompromised
herpetic keratitis- uni/bi lateral conjunctivits and pre auricular LN involvment
how is neonatal herpes transmitted
during delivery
what colour is a gram positive bacteria stained
purple
what colour is a gram negative bacteria stained
red
