Week 10 - Urinary Tract Infections, Fungi and Parasites

Question 1

UTI Terminology

Answer 1

Urethritis - inflammation of the urethra
Cystitis - inflammation of the bladder
Pyelonephritis - inflammation involving the kidneys
Glomerular nephritis - inflammation of the glomeruli

Question 2

Symptoms of Cystitis and Pyelonephritis

Answer 2

Cystitis
- dysuria (painful urination)
- frequency
- urgency
- suprapubic pain
Pyelonephritis 
- flank (over kidney) pain
- back ache 
- fever 
- rigors

Question 3

Why are females more at risk of UTI’s

Answer 3

Shorter urethra (easy access from distal urethra)
Proximity of anus to urethra
Pregnancy
Anatomical ease

Question 4

Dip stick tests and what they mean

Answer 4

Nitrite - indicates presence of bacteria which reduces nitrates to nitrite
Protein - increased protein can indicate kidney damage or presence of organisms in urine
pH - normally 6 but can be affected by diet and sometime bacteria
Blood - may indicate kidney or UT damage, or menstrual blood contamination

Question 5

Reading a Counting Chamber

Answer 5

If 22 dots seen for example
22 x 10 = 220 WBC in 1mm(cubed)
220 x 1000 = 220,000 WBC in 1 mL
220,000 x 1000 = 220 x 10^6 WBC per litre
Reported as >100 x 10^6 WBC/L

Question 6

Significance of Cell counts

Answer 6

WBC
- more than > 10 x 10^6/L is significant
RBC 
- more than > 10 x 10^6/L is significant
Epithelial cells 
- usually indicates a badly collected specimen

Question 7

Difference between a Definitive host and Intermediate host

Answer 7

Definitive - an animal in which the parasite passes its adult existence and/or undergoes a sexual reproductive phase
Intermediate - where parasite spends time not as an adult and with no sexual reproductive phase

Question 8

How do Viruses enter the body?

Answer 8

Oral
Percutaneous (skin)
Inhalation 
Transplacental
Sex

Question 9

Types of Parasites

Answer 9

Helminths (worms):
- Platyhelminths = flat worms
- Trematodes = flukes
- Cestodes = tapeworms
- Nematodes = round
Protozoa
Arthropods
- mites
- ticks

Question 10

Schistosomiasis

Answer 10

Trematode
Symptoms:
- fever
- cough
- can be asymptomatic
Males slightly smaller in length than females (7-20mm)
Diagnosed by eggs in faeces (100 -150 by 60 um)

Question 11

Taenia sp.

Answer 11

Cestode
Humans only definitive host
Eggs can survive for days to months 
Diagnosed by eggs in faeces (30-40 um)
Speciation by proglottids or scolex not the eggs

Question 12

Enterobius vermicularis (pinworm)

Answer 12

Nematode
Most common nematode infection
More common in children 
Adult female worm 8-13 mm 
Source of infection:
- eggs from environment 
Causes anal skin irritation

Question 13

Giardia lamblia

Answer 13

Protozoa 
Source of infection:
- contaminated water
- person to person contact
Causes:
- diarrhoea
- mucous secretion
- flatulence

Question 14

Fungi

Answer 14

Eukaryotic
Unicellular and multicellular
Approx 25 species cause the majority of infections
Chitin and/or cellulose in cell walls
Devoid of chlorophyll
Heterotrophic - not self sustaining
Reproduce asexually and sexually by spores

Question 15

Mycoses

Answer 15

Fungal infections of the body
Superficial and cutaneous mycoses - keratin and mucous membranes
Subcutaneous mycoses - dermis, subcutaneous tissue, bone
Systemic mycoses - internal organs esp. lungs
Opportunistic mycoses - usually cause infections in immunocompromised e.g. young, elderly

Question 16

How to grow a Fungal culture?

Answer 16

Room temp (20-28 degrees)
Generation time usually longer than bacteria 
Needs media that:
- maintains moisture content
- low pH
- high glucose content

Question 17

Fungal Types

Answer 17

Moulds
- fungi that exist as multicellular filamentous colonies
- e.g. Aspergillus sp. and Penicillium sp.
Yeasts and yeast-like fungi
- exist as single cells, grow as colonies
- e.g. Candida sp.
Dimorphic fungi
- may have a yeast like or filamentous form

Question 18

Moulds - Filamentous Fungi

Answer 18

Grow as long filaments (hyphae)
Hyphae intertwin to form a network - mycelium
Vegetative mycelium - nutrient absorbing and water exchanging portions of fungus that penetrates media or tissue
Aerial mycelium or reproductive mycelium - portion projecting above the surface, usually giving rise to reproductive spores

Question 19

Yeast and Yeast-like fungi

Answer 19

Cells that reproduce by budding
- generally unicellular 
- usually produce discrete colonies on agar
- often opportunistic
The people most susceptible are:
- immunocompromised 
- those treated with antibiotics
- diabetics

Question 20

List two methods used in a clinical laboratory to determine a urine colony count

Answer 20

Filter paper foot

Calibrated loop

Question 21

Give examples of a Geographical and Socio-economic factors that affect the distribution of parasites

Answer 21

Geographical
- climate
- soil type
- vegetation
Socio-economic 
- housing
- migration
- urbanisation

Question 22

Paediatric bag

Answer 22

It is a bag that you put over a childs genitals to collect urine if they are unable to control it themselves e.g. infant
It has a sticky surface which attaches to the genitals
Problems:
- long delays which can lead to overgrowth
- difficult to avoid normal flora contamination
- prone to faecal contamination

Question 23

How do you obtain Uric acid crystals and oxalate crystals in the urine

Answer 23

Both can be retrieved from diet
Uric acid - liver, anchovies, beer, pork, poultry
Oxalate - celery, tomatoes, oranges, beans
Both can also indicate kidney stones tho