Etiologic agents predominately seen neonate Flashcards Preview

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Flashcards in Etiologic agents predominately seen neonate Deck (67):
1

what is the gram staining of s. agalactiae?

gram-postive cocci in chains or pairs

2

what is the hemolytic status of s. agalactiae on sheep blood agar?

beta-hemolytic

3

what is the status of s. agalactiae when exposed to bacitracin and how does it differ from GAS

bacitracin resistant unlike GAS which is sensitive

4

s. agalactiae serologically is based on what

capsular polysaccharide

5

what is s. agalactiae virulence factor

capsular polysaccharide- antiphagocytic

6

for neonates and young infants what is the leading cause of bactermia alone or with meningitis with first 3 months

s. agalactiae

7

what ratio of pregnant women in counter invasive GBS

1/3

8

what other populations are effected by GBS

people >60yo and
diabetics, cirrhosis , malignancy and AIDS

9

in what tissues can GBS syndromes occur?

virtually all

10

how can GBS be transmitted

vertically during birth or horizontally from mother after birth

11

where does GBS colonize

mothers pharynx, vagina, and skin via rectal colonization

12

what is age and gender is most affected by GBS meningitis

neonates

13

what is the seasonality of GBS

none

14

what are the RF for GBS

LBW and material related events( I.E infections)

15

what two GBS forms of disease are recognized in neonatal infections

Early onset sepsis (bacteremia)
late onset sepsis (bacteremia and focal event)

16

how is acute onset GBS sepsis decribed

occurs within 6 days of birth
mother is source occurs in utero

17

how is late onset GBS sepsis defined

occurs week to 3 months after birth
source: postpartum in nursery, community or mother

18

what are focal infections in late onset GBS sepsis

meningitis
cellulitis
osteomyelitis
septic arthritis

19

what is more common early or late onset GBS sepsis

early

20

meningitis occurs more commonly in early or late onset GBS sepsis

late

21

How to diagnose GBS

isolate from neonate (CSF, Blood, Lungs)
isolate from mother (vagina, pharynx, GI, skin)
do a rapid slide agglutination or PCR

22

what is the treatment for GBS

Penicillin G

23

what is the prevention for early onset GBS infection

1. screen mother
2. IV AB to mother preterm and at labor
3. AB to mothers who have RF for GBS (premature membrane rupture)

24

what is the prevention for late onset GBS infection

NONE

25

what effect on etiology can intrapartum AB have on neonate

cause of infections switches from GBS to E.Coli

26

what is the gram staining of listeria monocytogenes

gram positive coccobacilli, motile and cornyeform

27

is listeria monocytogenes fastidious?

NO

28

what type of pathogen is listeria monocytogenes?

facultative intracellular pathogen

29

what two ways does listeria monocytogenes invade

1. invade and multiply in non-professional macrophages (epithelial and endothelial)
2. survive and multiply with phagocytic cells

30

what re the two virulence factors for listeria monocytogenes

lipoteichic acids- endotoxin
proteins- organism-directed phagocytosis and cell to cell spead

31

what is the incidence of listeria monocytogenes

sporadic and food-borne epidemics

32

how is listeria monocytogenes transmitted

1. food-borne: rare but high mortality
2. human to human: in utero or parturition
3. zoonosis

33

what is the reservoir for listeria monocytogenes

soil, water, fecal flora, food

34

what is the age and gender associated with listeria monocytogenes disease

pregnant women are are increase risk

35

what is the seasonality of listeria monocytogenes

summer

36

what are the RF for listeria monocytogenes

T cell suppression

37

what is the simple pathogenesis of listeria monocytogenes

Organism ingested -> pases through intestinal epithelium -> bacteremia

38

what is the POE for listeria monocytogenes

GIT

39

what is the purpose of listeriolysin O?

disrupts phagosome membrane allowing listeria cells to escape

40

what is the incubation time for listeria monocytogenes

~30 days

41

What possible immunity is there to listeria monocytogenes

primarily t-dependent immunity

42

what is the clinical syndrome of listeria monocytogenes in pregnancy

illness usually occurs at 3rd trimester
mother has flu-like symptoms rarely any CNS

43

what is the clinical syndrome of listeria monocytogenes in utero

1. early onset sepsis
2. spontaneous abortion
3. still born
4. premature births
mortality is high

44

what two organs has the most concentration listeria in early onset sepsis found?

LUNG and GUT

45

what is granulomatosis infantisepticum

rare condition of disseminated abscess or granulomas in multiple organs with papules in throat and skin
mortality is high!

46

what is the clinical syndrome of listeria monocytogenes in late onset sepsis

occurs during or after birth
symptoms start 1-2 weeks after birth
mortality is moderate
mother is asymptomatic

47

how is listeria monocytogenes diagnosed

Culture, Gram stain, CSF

48

what environment is best to culture listeria monocytogenes

cold-enrichment

49

what limitations are there to gram stain listeria monocytogenes

similar to corneybacterium, easily decolorized, small number

50

what is seen in CSF of listeria monocytogenes

monocyte predominante
glucose normal
low probability of visualizing listeria so leads to misdiagnosis

51

what is the treatment of listeria monocytogenes

ampicillin and gentamycin alternative is tmp-smx

52

what is the gram staining of e.coli

gram negative rod enteric and a coliform

53

is e- coli oxidase positive or negative

oxidase negative

54

which strain of e.coli causes the majority of UTI in humans

Extraintestinal pathogenic e. coli (ExPEC)

55

what is the most important virulance factor of e. coli in meningitis cases

K1

56

what does K1 in e.coli strains refer to

capsular serotype

57

what is the K1 serotype in e.coli responsible for

anti-phagocytic to neutophils

58

What type of pathogen is e.coli

facultative intracellular pathogen of macrophages and monocytes

59

what is the incidence level of e. coli

HIGH
2nd most common cause of invasive disease in neonate
most common gram-negative agent in neonatal meningitis
there is a

60

what affect can e.coli k1 vaginal colonization have on a pregnant female

increases chances of preterm

61

what is the source of e.coli k1 infection

mother's colon

62

how do you diagnose E.coli k1

culture and ID

63

what other gram negative agents can cause systemic infections in neonate

klebsiella pneumoniae and pseudomonas aeruginosa

64

klebsiella pneumoniae and pseudomonas aeruginosa occurs in what type of neonate

VLBW

65

what other Gram Positive agents that can cause systemic infections in neonates

staphlococcus epidermidis (CoNS) which causes early onset sepsis and meningitis

66

what neonate diseases can klebsiella pneumoniae cause

early and late onset sepsis. easy to culure and ID

67

what viruses can cause infection and morbidity in neonates

CMV
HSV 1/2
HHV 6/7
non-polio enterovirus - neonatal sepsis
HMV and laryngeal warts
LCMV