Urinalysis & CSF Flashcards
Helminth forms
Parasitic worms
Causes of CSF infection
- bacteria
- viruses
- spirochetes
- parasites
CSF infections are associated with:
- increased WBC counts
- alterations in normal glucose levels
- alterations in normal protein levels
Predisposing risk factors of CSF infection
- young
- elderly
- nutritional deficiencies
- immunologic deficiencies
- low glucose
- high protein
Bacterial meningitis
What does bacterial meningitis utilize?
Glucose
Cloudy CSF fluid specimen could indicate:
WBCs / bacterial meningitis
The majority of meningitis cases affects what age?
Under 5 years
How many tubes do you collect for a CSF fluid specimen?
4
Normal CSF characteristics:
- clear
- colorless
- sterile
Why should you never refrigerate CSF?
The organisms are sensitive to temperature
What media is used for CSF testing?
- chocolate
- BAP
- thio
How many ml are in the CSF tubes?
10ml
A positive direct smear (gram stain) of CSF is considered:
An alert value, report to physician
CSF changes seen in bacterial meningitis:
- increased turbidity
- increased neutrophils
- increased protein
- decreased glucose
What does a cytocentrofuged gram stain do?
Concentrates everything (it’s hard to focus CSF on a microscope)
What are the protein and glucose levels in Bacterial (acute) meningitis like?
- high protein
- low glucose
95% of bacterial (acute) meningitis is seen in:
Children under 5 years
Pathogens:
- Haemophilis influenza B
- Neisseria meningitidis
- Streptococcus pneumoniae
- GNRs
Bacterial (acute) meningitis
Most common type of meningitis
Viral (asceptic) meningitis
less severe
Pathogens:
- Enteroviruses
- herpes viruses
Viral (asceptic) meningitis
Causes flu-like symptoms
Viral (asceptic) meningitis
What are the glucose and protein levels like in viral (acute) meningitis?
- high glucose
- low protein
Encapsulates yeast
Cryptococcus neoformans
Rare cause of meningitis
Parasitic meningitis
Pathogens:
- Naegleria fowleri
- Acanthamoeba
- Balamuthis
- Angiostrongylus
- Plasmodium
- Toxoplasma
Parasitic meningitis
Rare cause of CNS infection
Fungal meningitis
Pathogens:
- Cryptococcus neoformans
- Coccidiodes immititis
- Histoplasma capsulatam
- Blastomyces dermititidis
- Candida
Fungal meningitis
Cryptococcus neoformans ID
India ink stain
Common in AIDS patients
Cryptococcus neoformans
Enters the body through respiratory droplets and multiplies/spreads via the blood
Mycobacterial meningitis
Pathogens:
- M. tuberculosis
- M. avium
- M. bovis
Mycobacterial meningitis
- acid-fast bacilli
- won’t stain with normal gram stain
Mycobacterial meningitis
Very thick cell wall, waxes, & has phospholipids
Mycobacterial meningitis
HIV is a risk factor
Makes you more susceptible
Mycobacterial meningitis
Slender, flexible, helically shaped bacteria
Spirochetal meningitis
Pathogens:
- Treponema pallidum
- Borellia burgdorferi
Spirochetal meningitis
- spiral shaped
- gram negative
Spirochetal meningitis
Causes Lyme disease
Borellia burgdorferi
LYME BURGERS
Causes neurosyphillus
In patients with HIV
Spirochetal meningitis / treponema pallidum
What does an AFB culture look for?
- Acid fast bacilli
- fungal spores
Major organs involved in urinary systems & diseases:
- bladders
- ureters
- kidneys
- urethra
- prostate
BUKUP
Most common nosocomial infection:
UTI
From catheters
Most common source of bacteremia:
UTI; urine cultures
Most common pathogen, E. coli:
UTI; urine cultures
Frequent pathogens, coliforms:
UTI; urine cultures
Nitrite, leukocytes, WBC and bacteria in a sediment indicate what?
Infection (UTI)
What will happen if a UTI is not treated?
It will spread
How is a UTI diagnosed?
By a combination of symptoms
Urinalysis -> urine culture
What tests certain gram negative bacteria?
Nitrate reductase test (Griess)
Urine must be in bladder for 4+ hours for this test, and it flags for a microscopic to be done
Nitrate reductase test (Griess)
Who is at risk for UTI?
- Immunocompromised (elderly & children)
- pregnant women (uterus puts pressure on bladder)
- kidney transplant recipients (foreign object in body / immunosuppressed / scarring)
What is a normal cause of bacteria in a non-sterile urine specimen?
Epithelial cells
Cystitis
Inflammation of the bladder
Pyelonephritis
Infection of the kidney
Bacteriruria
Presence of bacteria in the urine
Urethritis
Inflammation of the urethra
Prostatitis
GU infection in males involving the prostate
Cervivicitis
Inflammation of the cervix
Most common non-sterile urine specimen
Mid-stream clean catch
Noninvasive, patient can do it themselves
Sterile urine culture specimens:
- catheterized
- suprapubic aspirate
- cytoscopic
Suprapubic aspirate
Urine is aspirated through the belly into the abdominal cavity and into the bladder
(Done when there is an obstruction)
Cytoscopic
Urine specimen
Scopes through kidney
Deliver urine specimen to lab within ____ minutes
30
Refrigerate immediately if unable to process
What will happen if a urine culture is left sitting out?
Bacteria will multiply and it will affect urinalysis results
Urine culture setup:
1) mix urine thoroughly before streaking (it will settle so needs mixing)
2) inoculate with calibrated loop .001ml (calibrated to deliver a certain amount)
3) T-streak on BAP & MAC or EMB (T-streak: down middle, go to top, side to side all the way down plate)
Should bacteria be seen on a sterile urine specimen?
No
What is the purpose of a urine specimen count?
To determine actual infection from contaminating bacteria
> 100,000 colonies/ml of urine
Clinically significant
Over 10 colonies in urine =
Infection
A (urine) colony count greater than 10cfu is considered:
Significant unless sterile.
If sterile, ANY growth is considered significant.
What media do you do colony counts on?
BAP or MacConkey
Urine pathogens
1) GNRs
2) GPCs
3) GPRs
4) fungi
(Urine) GNR pathogens
Leading cause of UTIs
- E. coli
- pseudomonas
- klebisella
- acinetobacter
- enterobacter
Leading cause of UTIs
GNRs
(Urine) GPC pathogens
- enterococcus (in older men)
- S. saphrophyticus
- S. epidermidis
- S. aureus
- group B strep
(Urine) GPR pathogens
Listeria monocytogenes (Only a pathogen in rare cases)
(Urine) fungi pathogens
- Candida albicans
- Cryptococcus neoformans
- Blastomyces
- Coccidioides
- immititis
- Histoplasms capsulatum
Is bacillus in the urine considered contamination?
Almost always
Other agents of UTIs
1) anaerobes (when recovered from suprapubic aspirates / anaerobes don’t grow in presence of oxygen (sterile site in body = anaerobic))
2) C. trachoma & N. gonorrhoeae (these urine cultures are on BAP or MacConkey so these wouldn’t grow on either. Dr. Must be specifically looking for)
3) mycoplasma & Ureplasma (more common in neonates)
4) Gardnerella vaginalis
Microscan and Vitek
Susceptibility testing (antimicrobial) antibiotics & carb/sugar
- bacteria growing in wells = resistant to antibiotic
- bacteria not growing = susceptible
CSF infections can be caused by:
- bacteria
- viruses
- fungi
- Spirochetes
- parasites
Can be life threatening
95% of all bacterial meningitis occurs in:
Children under 5 years old
CSF associated with bacterial meningitis has:
- increased neutrophils (turbidity)
- decreased glucose
- increased proteins
Bacterial meningitis pathogens in neonates
1) group B strep
2) GNRs (E. coli, klebsiella spp., enterobacter spp.)
3) listeria monocytogenes
Causes bacterial meningitis in children (>2 years) and adults
1) streptococcus pneumoniae
2) Neisseria meningitidis
Causes bacterial meningitis in older adults (>65 years)
1) streptococcus pneumonia
2) Neisseria meningitidis
3) listeria monocytogenes
4) aerobic gram negative bacilli
Parasitic encephalitis (uncommon cause of meningitis) pathogen forms
- protozoan forms (free-living amoeba)
- helminth forms (parasitic worm)
Naegleria fowleri - protozoan form
Parasitic encephalitis
- almost always fatal
- in WARM fresh WATER and moist soil
Acanthamoeba spp. - protozoan form
Parasitic encephalitis
Found in solid, fresh & brackish water and sewage
Balamuthis mandrillaris - protozoan form
Parasitic encephalitis
No environmental sources identified
Protozoan forms
Free-living amoeba
Helminth forms
Parasitic worms
Angiostrongylus Cantonensis - helminth form
Parasitic encephalitis
- Thailand, Malaysia, Vietnam
- ingestion of GREEN LEAFY VEGETABLES
Plasmodium falciparum - helminth form
Parasitic encephalitis
CEREBRAL MALARIA, infected by the bite of an infected MOSQUITO, characterized by changes in MENTAL status, SEIZURES, motor deficits & COMA
Toxoplasma gondii - helminth form
Parasitic encephalitis
Eating RAW, undercooked MEAT or contact with cats, organ transplants
Fungal encephalitis pathogens
1) Cryptococcus neoformans
2) Coccidiodes immititis
3) Histoplasma capsulatum
4) Blastomyces dermatiditis
5) Candida spp. Including C. albicans, C. tropicalis, & C. parapsilosis
Coccidioides immitis
Fungal encephalitis
SW USA, Mexico, central/South America
Histoplasma capsulatum
Fungal infections
MS and Ohio river basins / patients with candidiasis (overgrowth of yeast)
Candida spp. Including C. albicans, C. tropicalis & C. parapsilosis
(Fungal encephalitis)
Like Histoplasma, seen in patients with overgrowth of yeast, (disseminated yeast infection causes cerebral abcess) / acquired as nosocomial infection in patients with catheters or microbial therapy)
Blastomyces dermatiditis
Fungal encephalitis
MS and Ohio river basins / spread by inhalation that results in pulmonary infection & spreads
Griess
Nitrate reductase test
Antimicrobial susceptibility testing
Rapid method most commonly used
E. coli (GNR)
UTI pathogen
antibiotic-susceptible strains emanating from patient’s fecal flora
Enterococcus (GPC)
UTI pathogen
Primarily in older men
S. saphrophyticus (GPC)
UTI pathogen
Predominantly in symptomatic sexually active women younger than 40 years
S. epidermidis (GPC)
UTI pathogens
Only 20% of cases, hospitalized patients >50 years, usually have had urinalysis tract surgery, indwelling catheters or chronic urinary tract disease
Listeria monocytogenes (GPR) (UTI pathogen)
In rare cases and only considered significant after consultation with physician
Bacillus spp. (GPR)
UTI pathogen
Isolation can almost always be considered contamination
Candida albicans (fungi) (UTI pathogen)
Rare in healthy adults, common in hospitalized patients,nearly colonies can resemble CoNS
Cryptococcus neoformans, Blastomyces dermatiditis, Coccidioides immitis, Histoplasma capsulatum (fungi)
(UTI pathogen)
Recovery of any of these in urine culture is considered highly significant and indicates a disseminated (spread) infection
Anaerobes
UTI
Significant when recovered from suprapubic aspirates
C. trachomatis and N. gonorrhoeae
UTI
Can cause:
- urethritis
- cystitis
- prostatitis
Mycoplasma & Ureaplasma
UTI
Neonates from lower socioeconomic groups
Gardnerella vaginalis
UTI
Commonly reflects vaginal contamination but also is an emerging UT pathogen. Repeated cultures with this organism as the primary isolate should be considered significant
What does CFU stand for?
Colony forming units
What is considered a significant colony count from a urine culture from a clean catch specimen?
Greater than 10 cfu
Why are UTIs the most common cause of nosocomial infections?
Because of patients with catheters
Why are UTIs more common in women than in men?
Because women have shorter urethral and their urethral openings are closer to the anus
Name two conditions that would make an individual more susceptible to an infection of the CSF:
- extremities of age (older young)
- nutritional & immunologic deficiencies
What percentage of bacterial meningitis cases occur in children
95%
What action should be taken by the MLT if bacteria is observed on the CSF gram stain? Why?
Call the physician if positive because it is considered an alert value
Cervicitis
A GU infection seen in females only
Cystitis
Inflammation of the bladder
Pyelonephritis
Infection of the kidney
Urethritis
Inflammation of the urethra
Prostatitis
A GU infection seen in males only
Bacteriuria
Presence of bacteria in the urine
If a urine specimen cannot be immediately processed, what action should be taken to preserve the specimen?
Refrigerate immediately and process within 2 hours
What urine pathogen is seen primarily in older men?
Enterococcus
Name three gram negative rods that are known to cause encephalitis in neonates:
E.coli, klebsiella, enterobacter
How do neonates acquire encephalitis?
Vertical transmission from mother to infant
What will the chemistry results be in a patient who has viral encephalitis?
Increased glucose, decreased proteins
Name four conditions that would make an individual more susceptible to contracting a UTI:
- extremities of age (elderly & children)
- pregnant women
- catheterized patients
- kidney transplant patients
Name the CSF pathogen that is associated with eating raw or undercooked meat, contact with cats and organ transplants:
Toxoplasma gondii
Causative agent for lyme’s disease
Borrelia burgdorferi
Causes cerebral malaria
Plasmodium falciparum
Found in soil, fresh & brackish water, sewage
Acanthamoeba
Found in MS & OH river basins
Blastomyces
Associated with war,, natural bodies of water
Naegleria fowleri
Causes neurosyphillis
Treponema pallidum
Associated with HIV patients
M. tuberculosis
Green leafy vegetables, snails & slugs
Angiostrongylus
What type of encephalitis causes mild, flu-like symptoms and will usually resolve on its own?
Viral
What urinary pathogen is mainly seen in women
S. saphrophyticus
How are most diarrheal pathogens acquired?
By ingesting a contaminated food or beverage
Name four host defenses of the GI tract and explain the role each one plays in the host defense process:
Normal flora - fights off pathogens
Stomach acidity - low pH kills organisms
Mucous layer - constant motion reduces chances for adherence
Colon / IgA fights off some organisms
What is the most common cause of diarrheal illness in children
Rotavirus
What diarrheal pathogen is associated with infectious outbreaks on cruise ships?
Calcivirus
What is the specific strain of diarrheal pathogen that produces shiga-like toxins?
E.coli 0157:H7
What is the most common cause of bacterial gastroenteritis in the world and is associated with contaminated poultry?
Campylobacter jejuni
Can migrate to liver
Entamoeba histolytica
Toxins have cytotoxic & neurotoxic effects
Shigella sonnei
Travelers returning from endemic areas
Cyclospora
Associated with AIDS patients
Microsporidia
Associated with hikers, mountain streams
Giardia lamblia
Resistant to chlorine
Cryptosporidium
Only known host is human, intracellular
Salmonella typhi
Resistant to refrigeration
Yersinia enterocoligica
Associated with fried rice
Bacillus cereus
Peptic ulcer disease
Helicobacter pylori
Antibiotic associated diarrhea
Clostridium difficile
Produces “rice-water” stools
Vibrio cholerae
Name two complications of Campylonacter infection:
Guillain-Barré syndrome and relative arthritis
Why will treatment with antibiotics delay the clinical improvement of patients with a Shigella infection?
If the antibiotic breaks down the cell wall, the organism releases the toxins and makes the patient sicker
Name two types of media that could be inoculated for the recovery of Salmonella in a stool specimen:
GN broth and Selenite
What temperature should media intended for the recovery of Campylobacter be incubated at?
42 degrees Celsius
What temperature should media intended for the recovery of Yersinia be incubated at?
Room temperature
What is the mortality rate of newborns that acquire bacterial meningitis?
20%
If a patient had viral meningitis, what will be seen on the gram stain of the CSF collected from this patient?
Nothing - viruses are not seen on gram stains
Name two common organisms known to cause meningitis in both adults AND children:
N. meningitidis
S. pneumoniae
1) Name the media used for urine culture setup:
2) Which of these is the colony count performed on?
1) BAP, MAC, or EMB
2) BAP
Name two sterile urine collection methods and a non-sterile collection method for urine cultures.
Sterile: suprapubic aspirate and cytoscopic
Nonsterile: mid-stream clean catch
On a direct gram stain of a CSF a yeast is observed. The yeast has a large halo around it on an India ink stained slide. What is the organism?
Cryptococcus neoformans
The primary etiologic agent for UTI is:
E.coli
Name a parasite that can cause encephalitis:
Naegleria fowleri
What is cystitis?
Inflammation of the bladder
Why should CSFs never be refrigerated before the culture has been set up?
Potential pathogens are sensitive to temperature
What are the expected chemistry results on a CSF in a patient with bacterial meningitis?
Increased proteins, decreased glucose
What is the name of the rapid screening test done on urines to determine the presence of a possible UTI?
Griess test
What is the Griess test detecting?
Nitrate reduction to nitrite
Loeffler media
Corynebacterium
BYCE
Legionella
Lowenstein-Jensen
Mycobacteria
Bordet-Gengou
Bordatella
A cytoscopic urine is collected and inoculated with a .001ml loop and after 24 hours of incubation it has 4 colonies counted from the BAP plate. Is this clinically significant? Explain:
Yes, because a cytoscopic urine is sterile, so any growth is significant
Name the 5 major organs of the urinary tract that are involved with infections of the UT:
BUKUP
1) bladder
2) urethra
3) kidneys
4) ureters
5) prostate
What media is used for CSF cultures?
Chocolate, thio, BAP
The expected colony count in a suprapubic urine specimen from a healthy individual is:
0 CFU/mL
Why are urine colony counts performed?
To determine if there is an infection
What is the primary population that acquires bacterial meningitis?
Children younger than 5 years old
Name a change seen in the physical characteristics of a CSF sample if a bacterial infection is present:
Increased turbidity (from WBCs/neutrophils)
Recovery of any of these in a urine culture is considered highly significant and indicates a disseminated infection:
- Cryptococcus neoformans
- Blastomyces dermatidis
- Coccidiodes immitis
- Histoplasma capsulatum
What is a disseminated infection?
Spread infection
Anaerobes are significant when:
Recovered from suprapubic aspirates