Week 10 - Urinary Tract Infections, Fungi and Parasites Flashcards
UTI Terminology
Urethritis - inflammation of the urethra
Cystitis - inflammation of the bladder
Pyelonephritis - inflammation involving the kidneys
Glomerular nephritis - inflammation of the glomeruli
Symptoms of Cystitis and Pyelonephritis
Cystitis - dysuria (painful urination) - frequency - urgency - suprapubic pain Pyelonephritis - flank (over kidney) pain - back ache - fever - rigors
Why are females more at risk of UTI’s
Shorter urethra (easy access from distal urethra)
Proximity of anus to urethra
Pregnancy
Anatomical ease
Dip stick tests and what they mean
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
Reading a Counting Chamber
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
Significance of Cell counts
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
Difference between a Definitive host and Intermediate host
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
How do Viruses enter the body?
Oral Percutaneous (skin) Inhalation Transplacental Sex
Types of Parasites
Helminths (worms): - Platyhelminths = flat worms - Trematodes = flukes - Cestodes = tapeworms - Nematodes = round Protozoa Arthropods - mites - ticks
Schistosomiasis
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)
Taenia sp.
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
Enterobius vermicularis (pinworm)
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
Giardia lamblia
Protozoa Source of infection: - contaminated water - person to person contact Causes: - diarrhoea - mucous secretion - flatulence
Fungi
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
Mycoses
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
How to grow a Fungal culture?
Room temp (20-28 degrees) Generation time usually longer than bacteria Needs media that: - maintains moisture content - low pH - high glucose content
Fungal Types
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
Moulds - Filamentous Fungi
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
Yeast and Yeast-like fungi
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
List two methods used in a clinical laboratory to determine a urine colony count
Filter paper foot
Calibrated loop
Give examples of a Geographical and Socio-economic factors that affect the distribution of parasites
Geographical - climate - soil type - vegetation Socio-economic - housing - migration - urbanisation
Paediatric bag
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
How do you obtain Uric acid crystals and oxalate crystals in the urine
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
