Year 2 Microbio Flashcards
Campylobacter jejuni
Chickens as reservoir (from poultry or milk)
Severe diarrhoea with fever, ulceration, and bleeding
Guillian Barre Syndrome and reactive arthritis are side effects that can occur after infection
Salmonella
-ve anaerobe
Salmonella typhi can cause typhoid/enteric fever
E. Coli
Normal flora, if not present might be problem
Escherichia coli gastroentritis – major causative agent of traveller’s diarrhoea (ETEC)
Clostridium perfringens
Watery diarrhoea
Clostridium botulinum
strictly anaerobic, endospores in insufficiently heated canned food
Besides GI symptoms, cholinergic blockage starting in CN (diplopia, photophobia) and moving down -> mortality from resp depression
give anti-toxins
Clostridium difficile
Can be normal flora
Nosocomial infection from antibiotic overuse
can cause pseudomembranous colitis
Bacillus cereus
Ubiquitous microbe, creates spores
Shigella
Dysentery (severe bloody, mucous and pus)
Staph aureus
heat resistant enterotoxins from ingestion of improperly stored/cooked food
Quick onset, self limiting
Vibrio cholerae
due to water contamination
causes profuse, odourless, watery diarrhoea; need fluids
Giardia lamblia
most common water-borne infection
pale, greasy, voluminous, odourous stools
Chlamydia
obligate intracellular ovoid
usually asymptomatic, can cause scarring
Gonorrhoea
gram -ve diplococci
resistant to penicillins
Syphilis
Primary stage – single firm, painless, non-itchy skin ulceration- chancre Secondary stage (7-10 weeks) – genital warts, diffuse rash involving palms of hands/soles of feet, general malaise Tertiary stage (in 3-30 years) – neuro (dementia, psychosis
Human Papilloma Virus (HPV)
Asymptomatic, most women have
almost all cervical cancer caused by HPV
Herpes simplex virus (HSV)
HSV-1 is oral, HSV-2 is genital although both at both now
mostly asymptomatic, can cause painful genital warts. still transmissible when in dormancy
Strep pneumoniae
bacterial acute meningitis
Gram +ve cocci
Often contiguous or distant foci of infection (Basilar skull fracture with CSF leak)
Neisseria meningitides
bacterial acute meningitis
Gram negative cocci
Invasive meningococcal disease (Meningitis, Septicaemia)
Haemophilus influenzae
bacterial acute meningitis
Gram negative cocobacilli
Mostly in children < 6 years
Enteroviruses
Most common viral in acute meningitis
Single stranded RNA
Severe in neonates, not severe in others
Mycobacteria tuberculosis
Chronic meningitis
Most severe form of tuberculosis
Very difficult to diagnose
Cryptococcus neoformans
Chronic meningitis
Environmental yeast, usually acquired by inhalation
In adults, fatal if not treated (high mortality rate even if not)
HSV
Causes both meningitis and encephalitis (leading cause of encephalitis)
HSV1>HSV2
Personality changes
Toxoplasma gondii
intracellular parasite - encephalitis
multiple brain lesions
Brain abscess
mostly through spread from outside (from the ear)
80% are strep infections
can grow mould
Subdural empyema (pus under dura) NO NOT LP
Group A strep pyogenes
Strep tonsilitis
complications: scarlet fever, rheumatic fever, acute post-strep glomerulonephritis
Common cold
rhinovirus (40%)
treat symptomatically
Sinusitis
viral>bacterial although hard to distinguish
resolves by itself, antibiotics if longer than 7 days and severe
Pharyngtitis/tonsilitis
viral (adenovirus)>bacterial (if purulent, strep pyogenes, H influenzae, N gonorrhoeae but could be EBV)
Otitis
Externa - bacterial/fungal
Media - often from viral nasopharyngeal URTI
Diphtheria
corynebacterium diphtheriae (gram positive fac anaerobe)
forms ulcers and extensive inflammation and swelling of throat and neck from toxins
rare in developed countries (vaccine)
EPSTEIN-BARR VIRUS (GLANDULAR FEVER)
infects pharyngeal epithelial cells → B cells
beware splenomegaly, no contact sports
Laryngitis
viral
Croup
viral (parainfluenza)
ACUTE LARYNGOTRACHEOBRONCHITIS
barking cough, hoarseness, stridor. 2-5 days, 1-3 years of age
Acute bronchitis
viral
BRONCHIOLITIS
viral in children
inflammation of bronchioles
Pneumonia
infection of alveolars
bacterial (strep pneumoniae)
Influenza
A: epidemics - antigen shifts
B: endemics - antigen drift
