M8 Normally Sterile Body Fluids Flashcards
What are the five main body cavities? Name the types of fluids that come from each.
Five main body cavities:
1. Cranial
2. Spinal - CSF
3. Thoracic - Thoracentesis or pleural or empyema fluid. Parietal pleura lines the thoracic cavity. Pleural fluid lubricates the pleura.
4. Abdominal - Paracentesis or ascitic or peritoneal fluid
5. Pelvic
Each body cavity is lined with membranes.
Sterile fluid between the membranes and organs reduces friction.
What is joint fluid and pericardium fluid called respectively?
Joint - Synovial fluid
Pericardium - Pericardial fluid
What are the two different terms for excess fluid based on their causes?
Exudative - excess fluid caused by Inflammation or infection (or cancer).
Transudative - excess fluid due to systemic changes (e.g. congestive heart failure).
Diseases can produce excess fluid (pleural effusion).
What is a common reason for fluid to accumulate in the peritoneum cavity (ascites) and what does it often contain?
Most cases are due to liver disease.
Ascetic fluid often contains inflammatory cells and elevated proteins.
What are some ways that infections occur in the peritoneum cavity?
- Perforation of the bowel
- Hematogenous
- External inoculation (e.g. surgery)
- Through infection within abdominal viscera
What is inflammation of the peritoneum membrane called?
Peritonitis is an inflammatory condition of the peritoneum membrane
What are the different types of peritonitis?
Peritonitis:
Primary—Infection spreads from the blood and lymph nodes; spontaneous bacterial peritonitis
Secondary—Occurs as a result of a perforated organ, surgery, traumatic injury, loss of bowel integrity, obstruction, or a preceding infection
Tertiary – symptoms of sepsis follow treatment for primary or secondary
What is a risk with people on continuous ambulatory peritoneal dialysis (CAPD)?
Dialysate fluid is injected into the peritoneal cavity via a catheter breaking the skin barrier, which increases the risk for infection
How is peritonitis diagnosed?
Peritonitis is diagnosed by the presence of two of the following:
1. Cloudy dialysate
2. Abdominal pain
3. Positive blood culture from dialysate
What organisms are to be suspected in an infection caused by peritoneal dialysis?
Patient’s skin microbiota may cause infection:
1. Staphylococcus epidermidis
2. Staphylococcus aureus
3. Streptococci
4. Aerobic or facultative gram-negative bacilli
5. Candida spp.
6. Corynebacterium spp.
Where is pericardial fluid located and how much is normal there and how much can there be in the case of infection?
Pericardial fluid is located in the pericardial space between the epicardium and the pericardium (15-20 mL of clear fluid).
Infections can complicate cardiac function because of the increase in fluid (up to 500 mL).
What usually causes pericarditis?
Agents of pericarditis are usually viruses.
What other infectious condition may accompany pericarditis and what contributes to the disease?
Myocarditis may accompany pericarditis.
The host’s inflammatory response contributes to effects.
What are common causes of myocarditis accompanying pericarditis?
Common causes include coxsackie virus, echoviruses, or adenovirus
What is arthritis and what are some causes of arthritis?
Arthritis is inflammation of the joint space as a result of:
1. Hematogenous spread
2. Direct extension of infection of the bone
3. Injection or insertion of material (e.g., hip replacement)
4. Arthritis may be infectious or immune related. Antigen–antibody interactions may occur after bacterial infections
What bacterial organisms can cause septic arthritis?
Causes of septic arthritis include:
1. S. aureus (most common)
2. Neisseria gonorrhoeae in young adults
3. Haemophilus influenzae in young children
4. Streptococci
5. Anaerobic bacteria (Bacteroides)
What viruses are common cause of viral arthritis?
Viral arthritis
Parvovirus, Hepatitis, Chikungunya, Rubella, HIV and HTLV-1
What is required for diagnosis of septic arthritis?
Diagnosis requires aspiration of joint fluid for culture and microscopic examination
How are most sterile body fluids (like synovial fluid) collected and transported?
Most fluid specimens are collected by aspiration (needle and syringe).
Body fluids from sterile sites are transported in a sterile tube
What is used often as a primary media for normally sterile body fluids and why?
Inoculation of blood culture bottles may be beneficial for pericardial, pleural, synovial, and peritoneal fluids as these specimens are supposed to be sterile and mostly suspected to have monomicrobic infections (like blood)
What is the ideal method to gram stain normally sterile fluids?
Clear fluids are concentrated by cytocentrifugation. Samples are Gram stained.
What media is most often used for normally sterile fluids?
CA, BA, a liquid media (bottles or thio or Fab).
What type of stains / preparations are used for samples suspected with fungi and mycobacteria?
Direct potassium hydroxide (KOH) preparation or calcofluor white stain is used for fungi.
Acid-fast stain is used for mycobacteria.
What are some various types of osteomyelitis that require a bone marrow aspirate to diagnose?
May be necessary to diagnose brucellosis, histoplasmosis, blastomycosis, tuberculosis, and leishmaniasis
Why may a person with HIV have to give a bone marrow aspirate?
Disseminated infections in patients with human immunodeficiency virus (HIV) may be found from bone marrow samples (e.g., Cryptococcus spp.)
What kind of sample is used to help diagnose osteomyelitis?
Bone biopsies are often collected when osteomyelitis is suspected
Such as May be necessary to diagnose brucellosis, histoplasmosis, blastomycosis, tuberculosis, and leishmaniasis
What can cause osteomyelitis?
Osteomyelitis can result from:
1. Hematogenous spread of an infectious agent
2. Invasion of bone from an adjacent site
3. Trauma or surgery
4. Poor circulation (e.g., diabetes)
What is the most common organism associated with osteomyelitis?
S. aureus
Where is bone marrow aspirated from for diagnosing osteomyelitis?
Bone marrow is aspirated from the interstitium of the iliac crest
Blood cultures are useful for processing bone marrow material
How are bone marrow aspirates / biopsies examined in the micro lab?
- Clotted specimens are homogenized before inoculation
- Grinding of bone with a mortar and pestle may be necessary
- The same media for other sterile body fluids is used
- Special media for Brucella spp. may be needed
- No standard approach to identify prosthetic joint infections exists
What organisms may cause infection of solid tissues?
Any agent of infection may cause disease in the tissue
What are some organisms that infect tissue that require special media to culture?
Infectious agents in tissue requiring special media:
1. Actinomyces spp.
2. Brucella spp.
3. Legionella spp.
4. Bartonella henselae
5. Systemic fungi
6. Mycoplasma spp.
7. Mycobacteria spp.
8. Viruses
How are solid tissues collected for the microbiology lab?
- Biopsies must be aseptically collected and submitted in a sterile container (wide-mouthed container with screw cap).
- Container is placed in anaerobic pouch if anaerobes are suspected.
- Mincing the specimen is recommended before culturing.
- A portion of a surgical specimen is saved for at least 4 weeks.
What three types of examinations are solid tissues divided up for?
Sample is cut into sections for fungal, bacterial, and histologic examination
What kind of culture are used to isolate viruses?
Tissue may be inoculated to cell culture for the isolation of viruses
What organism are the tissue of all fetuses and babies who have died of an infectious condition cultured for?
Listeria
What type of nucleic acid based methods has been successful for the ID or organisms from joint fluids?
PCR and 16s rRNA sequencing has been successful for the identification of organisms
Note: Has to be specifically requested.
What sterile body fluids can benefit from nuclei acid based testing methods?
Peritoneal Dialysis Fluid
Genital Ulcers or Organisms in Biofilms
Joint Fluids
Note: Specimens Varies, requires the use of manufacturer’s instructions
