M8 Normally Sterile Body Fluids

Question 1

What are the five main body cavities? Name the types of fluids that come from each.

Answer 1

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.

Question 2

What is joint fluid and pericardium fluid called respectively?

Answer 2

Joint - Synovial fluid
Pericardium - Pericardial fluid

Question 3

What are the two different terms for excess fluid based on their causes?

Answer 3

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).

Question 4

What is a common reason for fluid to accumulate in the peritoneum cavity (ascites) and what does it often contain?

Answer 4

Most cases are due to liver disease.
Ascetic fluid often contains inflammatory cells and elevated proteins.

Question 5

What are some ways that infections occur in the peritoneum cavity?

Answer 5

1. Perforation of the bowel
2. Hematogenous
3. External inoculation (e.g. surgery)
4. Through infection within abdominal viscera

Question 6

What is inflammation of the peritoneum membrane called?

Answer 6

Peritonitis is an inflammatory condition of the peritoneum membrane

Question 7

What are the different types of peritonitis?

Answer 7

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

Question 8

What is a risk with people on continuous ambulatory peritoneal dialysis (CAPD)?

Answer 8

Dialysate fluid is injected into the peritoneal cavity via a catheter breaking the skin barrier, which increases the risk for infection

Question 9

How is peritonitis diagnosed?

Answer 9

Peritonitis is diagnosed by the presence of two of the following:
1. Cloudy dialysate
2. Abdominal pain
3. Positive blood culture from dialysate

Question 10

What organisms are to be suspected in an infection caused by peritoneal dialysis?

Answer 10

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.

Question 11

Where is pericardial fluid located and how much is normal there and how much can there be in the case of infection?

Answer 11

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).

Question 12

What usually causes pericarditis?

Answer 12

Agents of pericarditis are usually viruses.

Question 13

What other infectious condition may accompany pericarditis and what contributes to the disease?

Answer 13

Myocarditis may accompany pericarditis.

The host’s inflammatory response contributes to effects.

Question 14

What are common causes of myocarditis accompanying pericarditis?

Answer 14

Common causes include coxsackie virus, echoviruses, or adenovirus

Question 15

What is arthritis and what are some causes of arthritis?

Answer 15

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

Question 16

What bacterial organisms can cause septic arthritis?

Answer 16

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)

Question 17

What viruses are common cause of viral arthritis?

Answer 17

Viral arthritis
Parvovirus, Hepatitis, Chikungunya, Rubella, HIV and HTLV-1

Question 18

What is required for diagnosis of septic arthritis?

Answer 18

Diagnosis requires aspiration of joint fluid for culture and microscopic examination

Question 19

How are most sterile body fluids (like synovial fluid) collected and transported?

Answer 19

Most fluid specimens are collected by aspiration (needle and syringe).

Body fluids from sterile sites are transported in a sterile tube

Question 20

What is used often as a primary media for normally sterile body fluids and why?

Answer 20

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)

Question 21

What is the ideal method to gram stain normally sterile fluids?

Answer 21

Clear fluids are concentrated by cytocentrifugation. Samples are Gram stained.

Question 22

What media is most often used for normally sterile fluids?

Answer 22

CA, BA, a liquid media (bottles or thio or Fab).

Question 23

What type of stains / preparations are used for samples suspected with fungi and mycobacteria?

Answer 23

Direct potassium hydroxide (KOH) preparation or calcofluor white stain is used for fungi.

Acid-fast stain is used for mycobacteria.

Question 24

What are some various types of osteomyelitis that require a bone marrow aspirate to diagnose?

Answer 24

May be necessary to diagnose brucellosis, histoplasmosis, blastomycosis, tuberculosis, and leishmaniasis

Question 25

Why may a person with HIV have to give a bone marrow aspirate?

Answer 25

Disseminated infections in patients with human immunodeficiency virus (HIV) may be found from bone marrow samples (e.g., Cryptococcus spp.)

Question 26

What kind of sample is used to help diagnose osteomyelitis?

Answer 26

Bone biopsies are often collected when osteomyelitis is suspected

Such as May be necessary to diagnose brucellosis, histoplasmosis, blastomycosis, tuberculosis, and leishmaniasis

Question 27

What can cause osteomyelitis?

Answer 27

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)

Question 28

What is the most common organism associated with osteomyelitis?

Answer 28

S. aureus

Question 29

Where is bone marrow aspirated from for diagnosing osteomyelitis?

Answer 29

Bone marrow is aspirated from the interstitium of the iliac crest
Blood cultures are useful for processing bone marrow material

Question 30

How are bone marrow aspirates / biopsies examined in the micro lab?

Answer 30

1. Clotted specimens are homogenized before inoculation
2. Grinding of bone with a mortar and pestle may be necessary
3. The same media for other sterile body fluids is used
4. Special media for Brucella spp. may be needed
5. No standard approach to identify prosthetic joint infections exists

Question 31

What organisms may cause infection of solid tissues?

Answer 31

Any agent of infection may cause disease in the tissue

Question 32

What are some organisms that infect tissue that require special media to culture?

Answer 32

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

Question 33

How are solid tissues collected for the microbiology lab?

Answer 33

1. Biopsies must be aseptically collected and submitted in a sterile container (wide-mouthed container with screw cap).
2. Container is placed in anaerobic pouch if anaerobes are suspected.
3. Mincing the specimen is recommended before culturing.
4. A portion of a surgical specimen is saved for at least 4 weeks.

Question 34

What three types of examinations are solid tissues divided up for?

Answer 34

Sample is cut into sections for fungal, bacterial, and histologic examination

Question 35

What kind of culture are used to isolate viruses?

Answer 35

Tissue may be inoculated to cell culture for the isolation of viruses

Question 36

What organism are the tissue of all fetuses and babies who have died of an infectious condition cultured for?

Answer 36

Listeria

Question 37

What type of nucleic acid based methods has been successful for the ID or organisms from joint fluids?

Answer 37

PCR and 16s rRNA sequencing has been successful for the identification of organisms

Note: Has to be specifically requested.

Question 38

What sterile body fluids can benefit from nuclei acid based testing methods?

Answer 38

Peritoneal Dialysis Fluid
Genital Ulcers or Organisms in Biofilms
Joint Fluids

Note: Specimens Varies, requires the use of manufacturer’s instructions