gram +ve bacili Flashcards
coryebacterum is gram — bacilli arranged in — or – shapes
this are – or — so basically they can grow in presence or absence or —
are — forming
colonise —–
+ve
v or L
aerobic , facultative anaerobes
oxygen
non spore
skin, upper respiratory tract & genito-urinary tract
important species of corynebacterium are:
- Corynebacterium diphtheriae
- Other less common pathogens
* C. jeikeium
* C. ulcerans
* C. haemolyticum (now known as Arcanobacterium
haemolyticum)
the epidmeoly of corynebacterium diphtheria :
- – the only known reservoir
- cases and — carriers
- spread by — by which – carries may shed for weeks
humas
asymptomatic
droplet
nasal
incubation period of dipheria is — and it may involve ant — or —
- classified based – of infection as:
- at risk are:
- reduced incidence w —
2-6 days ( range 1-10 days)
mucious membrane or skin
site as
- Anterior nasal
- Tonsillar and pharyngeal
- Laryngeal
- Cutaneous
- children , unvaccinated , overcrowding
- immunisation programme
The disease “diphtheria” is caused by – secreted by the bacteria at the site of infection
* Not all strains produce –
* The toxin produced is – in all 3 strains
- complications attainable to toxins include :
exotoxin
toxin
identical
Myocarditis + Neuritis
the toxin is formed by 2 subunits :
1- subunit A inhibits —
2- subunit B helps —
- toxin A inhibits — which is required for protein sythesis
- this leads to — and results in many complications as:
protein scythes
helps trasporter A into the cell
E2F ( elongation factor 2)
Myocarditis (1-2 weeks from onset)
* Neurological disease – paralysis soft palate, cranial nerve palsies, motor
deficits etc.
diphtheria diagnosis
1- clinical by history of — and —
and by —- the severe exudative tonsillitis
2- —– swab as:
- —
- — on selective media which the growth takes up to —
- Corynebacterium diphtheriae produces classical grey/black or brown colonies
vaccination or travel ( especially to countries w low vaccination rate )
examination
Nasal/ Throat/ Pharyngeal swab
NAAT
culture
48 hours
diphtheria management :
1- treatment by :
- diphtheria –
- antibiotic as –
2- supporting n monitoring by :
- — mamagemtn
- —-
- —
3- infection prevention n control by:
- — precautions
- —- to public health contacts
4- follow up by:
- —- to ensure eradication
- Diphtheria toxoid — during their
convalescence since natural infection does not reliably induce immunit
- Diphtheria antitoxin
- ## Antibiotics: penicillin (or erythromycin)
- Airway management
- ECG & enzymes
- ## Neurology
- Droplet precautions
- ## Notifiable infection to public health- contacts
listeria monocytogenes are:
- gram — bacillus
- — forming
- are —
- exhibits characteristics tumbling motility at —
- isolated from –
- grows in wide ranges of —
positive
non spore
aerobes / facultative anaerobes
25 c
Soil/ water/ vegetation, faeces of infected mammals, birds
temperatures (2-37c ) which can even grow in refridgated foods
transmission of listeria can be by :
- Animal contact
- Eating contaminated foods
* milk
* eating certain soft cheeses
* pate
* undercooked meat
* unwashed vegetables etc. - Vertical transmission from mother to foetus
listeria incubation period varies from — to —
most infections are — or — in healthy adults
- Influenza-like illness / gastroenteritis occurs in —-
- opportunistic pathogens affects at risk groups are
1-2 weeks up to 90 days
asymptomatic or mild influenza like illness or diahorrea
occupational exposure as in farmers vet butchers
preg ladies neonates n immunosupression
opportunistic infections in preg;
Perinatal listeriosis
“Influenza-like illness” – usually 3rd trimester.
* Fever, myalgia, backache, headaches, arthralgia
Perinatal infection may result in
* Miscarriage or intrauterine death
* Premature labour and infected infant
* Neonatal listeriosis
Neonatal listeriosis
check slide 20 21
brucellosis ( zoonosis )
* – Gram– coccobacillus (Biosafety level 3)
* are —
* are —
* Strict –
* — growing
* — pathogen
small
-ve
non motile
non capsulated
aerobes
slow
intracellular
brucella :
* Unpasteurised dairy (goat, sheep, camel, cow) or meat processing –
risk
* — – mostly sheep, goats, and camels. Most virulent. Never
reported in Ireland
* — causes spontaneous abortion in cattle, was common in
Ireland but less virulent in humans. Last case (livestock) 2006, declared
eradicated 2009
* Also B. canis (dogs), B. suis (pigs) and others
b metiltensis
b abortus
human brucellosis ingested by — and – which leads to :
- multiplies in regional —
- enters —
- spread to – and — system
- small — produced in target sites
PMNs(Polymorphonuclear
leukocytes) and macrophages
lymph nodes
blood stream
organs n reticule endothelial system
granulomata
Incubation period
* 2-4 weeks
Influenza-like illness (50% infected patients)
* Dry cough/lassitude/arthralgia, myalgia/headache/weight loss
* Fever (Rigors/sweating)
* Lymphadenopathy
* Hepato/splenomegaly
* Depression
are clinical presentations of –
acute brucellosis
Occurs in untreated or inadequately treated
patients which can recur over months or years
Characterised by
* Evening depression
* Sweating episodes – distinctive smell
* Arthritis: aches/weakness. Sacroiliac joints &
spine
* Insomnia
are clinical presentations of –
chronic brucellosis
diagnosis of brucellosis :
treatment :
- —- for 6 weeks
- Pregnant patients, children or patients intolerant of — so we use —- , —
diagnosis clinical suspicion n geographic association :
LABORATORY INVESTIGATIONS
1. Blood cultures;
* 30 - 50% positive in acute infection,
* take > 1 set
* Biosafety Level 3
2. Bone marrow aspirate
3. Serology
4. NAAT- blood, tissue (reference laboratory)
- Doxycycline + rifampicin
- doxycycline :
cotrimoxazole + rifampicin
prevention of bru—-
Animals
* Culling infected livestock
* Immunisation of healthy livestock
– live attenuated strain of Brucella abortus
Humans
* Pasteurisation of milk
* Avoid unpasteurized goat or sheep soft cheese in geographical areas where
B. melitensis is prevalent
* Post exposure prophylaxis e.g. laboratory exposure, vaccine accidents with
vets or farmers