module one

Question 1

epidemiology of campylobacter

Answer 1

contaminated food, water borne, direct contact with infected animals, bimodal age distribution, infections peak in summer, asymptomatic

Question 2

features of campylobacter

Answer 2

gram negative, spiral rod, tumbling mobility, common cause of gastroenteritis

Question 3

virulence of campylobacter

Answer 3

motility – mucus penetration
chemotaxis – L-serine, L-fructose in mucus allows it to detect the wall of the gut
invasion – mechanism unknown
adhesion – LPS, pili, fimbriae
toxins – cholera like enterotoxin and cytolethal distending toxin

Question 4

what are these toxins associsted with and what is the mechanism of:
cholera like entero toxin and cytolethal distending toxin

Answer 4

associated with campylobacter jejuni
cholera like:
activates adenylate cyclase -> cAMP production -> efflux of Ca+/Na- –> loss of water –> watery diarrhoea
cytolethal:
DNase –> apoptosis and cell death –> bloody diarrhoea

Question 5

symptoms of campylobacteriosis

Answer 5

flu like symptoms - headache, fever, myalgia
acute onset has abdominal pain, nausea, and diarrhoea (secretory – jejunum and ileum. dysentery – colon)

Question 6

diagnosis of campylobacteriosis

Answer 6

microaerophilic, growth at 43 degrees, spiral morphology on the gram stain, PCR

Question 7

treatment of campylobacteriosis

Answer 7

fluid and electrolytes

Question 8

what is a dermatophyte infection

Answer 8

superficial infection of keratinised tissue

Question 9

pathogenesis of dermatophytes

Answer 9

keratinophilic – invasion of keratinised tissues like elastases and keratinases
superficial infection – inflammation and slow infection, granulation and resolution on skin
itching and scratching – causes maceration, can lead to secondary bacterial infection

Question 10

treatment of dermatophyte infection

Answer 10

feet/body – topical antifungals
hair/nails – oral antifungals

Question 11

diagnosis of dermatophyte infection

Answer 11

clinical
macro/microscopic appearance – colony morphology

Question 12

prevention of dermatophyte infection

Answer 12

avoid and treat infected animals, good personal hygiene

Question 13

what is giardia

Answer 13

an intestinal protozoan parasite with 2 forms; trophozoite and cyst

Question 14

difference between trophozoite and cyst in giardia

Answer 14

trophozoite – motile and disease causing
cyst – environmental and infective

Question 15

symptoms of giardia

Answer 15

can range from acute, to moderate, to chronic
acute onset – watery diarrhoea and cramps

Question 16

pathogenesis of giardia – known and postulated

Answer 16

known:
- attachment of ventral adhesive disk in duodenum and jejunum
- blunting of villi leading to loss of enzyme function
- proteinases which disrupt tight junctions

postulated:
- enterotoxins
- immune mediated damage
- change in microbiota

Question 17

treatment of giardia

Answer 17

rehydration and electrolytes
metronidazole and albendazole are effective against trophozoites but resistance is emerging

Question 18

diagnosis of giardia

Answer 18

detection of trophozoites and cysts in faeces, antigen detection, PCR