Misc Body Sites (Wounds, Abscesses, Tissues and Bones) Flashcards
Traumatic injury Decubitus ulcers Animal or human bites Burns Foreign bodies in the skin or mucous membranes
Exogenous
Caused by normal flora:
- Mouth flora causing dental infections
- Intestinal flora causing appendicitis
- Upper respiratory flora causing sinusitis
Endogenous
What are the sample types for wounds and abscesses?
Aspirate in syringe, sterile swab, and hardware/foreign body
What is the goal when collecting specimens from wounds and abscesses?
Optimum recovery of pathogens present without introducing contaminated flora
T or F. Swabs are optimal specimen types.
False, tissues and aspirates are preferred
Types of anaerobic culture collection systems
- Port-a-cul (Aer and Ana)
- BBL anaerobic collection tube
Types of collection for aerobic swabs/general purpose swab systems
E swab, and BBL culturette
What method is used for culturing foreign bodies and hardware?
Sonication (in approx. 1 mL of saline)
When do we use PEA plates for culturing wounds and abscesses?
On extremities and sources below the diaphragm
Common skins contaminants found in wound culture (6)
Diptheroids, Coag negative staph, alpha hemolytic strep, nonhemolytic strep (not Group D), Propionibacterium sp., Bacillus sp.
What is the general rule when evaluating a direct gram stain with culture growth for a wound culture?
Many PMNs and no/rare/few SECs = good quality specimen
Many SECs and no/few PMNS = not consistent with infection
What rule do we follow when working up potential pathogens from a wound culture?
Rule of 3
What is the rule for doing susceptibility testing on potential pathogens from a wound culture?
Perform ID with SS testing on up to 3 PPs: including S. aureus, Enterococcus, Enterobacterales, Ps. aeruginosa, other nonfermenters, (excludes Coag negative staph)
How long are wound cultures held before confirming as negative?
72 hours
What are the exceptions to the 72 hour holding rule and how do we deal with those organisms?
Shrink seal plates to ensure the media doesn’t dry out.
Actinomyces, Nocardia, Francisella, Bartonella, Brucella, and Propionibacterium
How long do we hold Actinomyces for?
5 days
How long do we hold Nocardia for?
5 days
How long do we hold Francisella for?
5 days
How long do we hold Bartonella for?
14 days
How long do we hold Brucella for?
28 days
How long do we hold Propionibacterium for?
14 days
Human bite and animal bite infections caused by _____ and _____, respectively can ultimately lead to underlying bone infection.
Eikenalla corrodens, and Pasteurella multocida
T or F? Bones and tissues are considered sterile.
True
Pathogens enter tissue thru breaks in the skin or normally intact mucous membranes.
Tissue infection
Develop osteomyelitis from hematogeneous spread of infectious agent, invasion of bone tissue from an adjacent site of infection (i.e., joint, dental), or breakdown of tissue caused by trauma/surgery.
Bone infection
T or F? Formalin is suitable for tissue and bone cultures.
False
What do we do with a tissue or bone sample from the ER?
Process it ASAP and keep moist if there is a delay
T or F? Bones are sonicated for culture.
True
What is different about preparing tissue and bones for fungal culture?
Its preferable to mince specimen instead of grind
How long do we hold tissue/ bone culture plates, how long do we hold the thio broth cultures?
3 days, 5 days
When do we check thio broth for culture growth?
48 hours
Which organisms found in tissue/bone culture do we always perform full ID and MICs for?
S. aureus and CNS
Which organisms found in tissue/bone culture do we always perform a Pen Etest for?
Viridans strep and Strep anginosus
Which organism found in tissue/bone culture do we always perform and Etest for?
Yeast
