Misc Body Sites (Ear, Genital and Cath tip)

Question 1

Common ear infections?

Answer 1

Otitis media (middle ear infection)
Otitis externa (swimmer's ear) - caused by Psuedomonas

Question 2

When is susceptibility testing done for ear cultures?

Answer 2

On any single isolate that is a potential pathogen, predominant or pure

Question 3

Common contaminating flora for ear cultures?

Answer 3

Coagulase negative staph
Diptheroid bacilli
Bacillus sp.

Question 4

What does accurate diagnosis of genital culture depend on?

Answer 4

Separation of pathogens from normal flora

Question 5

T or F? You must know the exact source information of the specimen to determine workup.

Answer 5

True

Question 6

When do you not do a direct gram stain for a genital culture?

Answer 6

When it is a vaginal culture

Question 7

Common cause of infections around IUDs?

Answer 7

Actinomyces

Question 8

What organism are you looking for in a wet prep with clue cells?

Answer 8

Gardernella vaginalis

Question 9

What are the guidlines for interpreting direct gram stain results from a genital culture?

Answer 9

PMNs and no/few SECs - good

SECs and no/few PMNs - poor

Question 10

When is susceptibility testing for genital cultures appropiate?

Answer 10

They are not routinely performed except for from a “sterile” genital source (surgically obtained)

Question 11

Laboratory testing for N. gonorrhoeae?

Answer 11

Molecular assays, and cultures (not routinely performed except when susceptibility test is indicated)

Question 12

Besides the genitals, where else do you commonly see N. gonorrhoeae infections?

Answer 12

Rectum, throat, blood, skin lesions, or joint fluid

Question 13

What is the transport media for N. gonorrhoeae?

Answer 13

Jembec plate (Modified Thayer Martin) media

Question 14

What tests are done on growth from Jembec plate?

Answer 14

Gram stain (GNDC) and oxidase (pos)

Question 15

Which organism found in vaginal cultures may be a cause of systemic disease to newborn if contracted during pregnancy?

Answer 15

Group B strep (GBS)

Question 16

What is the national standard for screening pregnant women for GBS?

Answer 16

32-35 weeks

Question 17

What are the accepted specimen types for GBS?

Answer 17

Perianal and genital (common), also cervix and vagina

Question 18

What special broth culture is used to detect GBS? What does a positive result look like?

Answer 18

Carrot Broth (starch, peptones serum with inhibitors) + nutrient enrichment tiles with pigment production; a positive result is an orange pigment

Question 19

What is the Denver health standard for susceptibility tests on GBS?

Answer 19

Test for Clindamycin SS for all pregnant women

Question 20

What is done after receiving a positive result for GBS in carrot broth?

Answer 20

Subculture and isolate on BAP

Question 21

Which type of GBS is carrot broth not sensitive for?

Answer 21

Non-hemolytic GBS

Question 22

What is the standard for testing negative results in carrot broth?

Answer 22

Subculture to BAP and look for suspicious non-hemolytic colonies @24-48 hrs

Question 23

T or F. Nosocomial bloodstream infections are often cath-tip related.

Answer 23

True

Question 24

What also must be done concurrently with cath tip cultures?

Answer 24

Blood cultures

Question 25

What is the purpose of cath tip culture?

Answer 25

To determine true sepsis from contamination

Question 26

How does most cath tip septicemia begin?

Answer 26

As localized infection of the intradermal catheter wound

Question 27

What is the cause of cath tip septicemia?

Answer 27

Migration of skin organisms at the insertion site into cutaneous catheter, colonization of the cath tip

Question 28

What are the common causes of cath tip infections?

Answer 28

Coag negative staph (especially), candida sp, enterococci, and staph aureus

Question 29

What are the keys to interpreting cath tip cultures?

Answer 29

Determining whether the organisms recovered is the same from blood culture; # of colonies that grow directly relate to whether cath tip is source of infection

Question 30

Which colonies are counted from a cath tip culture?

Answer 30

All of them

Question 31

What are the rules of numbers of colonies worked up from cath tip culture?

Answer 31

Isolate > = 15 significant colonies - ID/MICs, preferably from blood culture isolate

Isolate < 15 if colonies not significant - report organisms with descriptive ID