CNS Infections- Other agents of neonatal meningitis/encephalitis

Question 1

E. coli description

Answer 1

• Gram-negative rod
• Enteric bacteria and a coliform
• Oxidase negative
• Encapsulated (exopolysaccharide)
• Capsule provides serum resistance and resistance to killing by neutrophils (aka its antiphagocytic)
• Facultative intracellular pathogen of macrophages and peripheral blood monocytes

Question 2

Over 200 serotypes of various ______ exist.

All strains of E. coli isolated from extraintestinal infections sites in humans are now designated as _________. These strains are clonal and possess specific virulence factors necessary to cause disease at various non-intestinal sites.

Answer 2

K antigens

extraintestinal pathogenic E. coli (ExPEC)

Question 3

________ cause the majority of urinary tract infections (UTIs) in humans.

Answer 3

ExPEC strains

Question 4

The important virulence factor for strains causing meningitis is the __________.

Answer 4

K1 antigen/sialic acid residues

K1 also refers to a specific capsular serotype.

Question 5

K1 antigen is highly associated with _____________.

Answer 5

severe disease and higher incidence of neurological sequelae

Question 6

Capsular material is identical to _________. Both capsules are poorly immunogenic in humans due to molecular mimicry.

Answer 6

Neisseria meningitidis group B capsule

Question 7

Incidence of E. coli in the US is high, causing about 3,500 cases/y of _____________

Answer 7

invasive neonatal disease (sepsis, meningitis, neonatal enterocolitis)

Question 8

The most common Gram-negative agent of ____________.

Answer 8

• neonatal meningitis in the US

- 2nd most common agent of invasive disease in the neonate

Question 9

Prophylaxis for GBS is causing increasing incidence of ___________

Answer 9

invasive disease by Gram-negative bacteria and especially E. coli K1

Question 10

There is strong association between vaginal colonization by E. coli K1 and _________

Answer 10

preterm birth

source of e. coli is mother’s colon

Question 11

Another agent causing blood/systemic infections in the neonate is

Answer 11

• Klebsiella pneumoniae (encapsulated; K1 or K2 serotypes) causes early and late neonatal sepsis in premature infants, agent is simple to culture and identify.
• Pseudomonas aeruginosa & Klebsiella pneumoniae are found in VLBW infants

Question 12

A gram positive agent that causes early neonatal sepsis and meningitis is

Answer 12

Staphylococcus epidermidis (CoNS)

Question 13

6 viruses causing infection and morbidity in neonates

Answer 13

1. Cytomegalovirus (CMV)
2. Herpes simplex virus (HSV 1 & 2)
3. Human herpes virus 6 & 7 (HHV 6 & 7)
4. Non-polio-enterovirus infections (neonatal sepsis/viremia)
5. Human papilloma virus and laryngeal warts
6. Lymphocytic choriomeningitis virus (LCMV)

Question 14

Mycoplasma spp, Ureaplasma urealyticum, U. parvum and Chlamydia trachomatis are closely associated with ____________.

Answer 14

vertical transmission/during parturition, mother is often asymptomatic, newborn is not

Question 15

Ureaplasma urealyticum, U. parvum infection of the child occurs via:

Answer 15

1. ingestion of infected amniotic fluid after agent ascends from the vaginal canal.
2. intrauterine bacteremia after crossing the placenta from mother’s blood.
3. aspiration during passage through birth canal

These agents produce respiratory infections from perinatal period to 3-y-o-age, esp. in premature infants with chronic lung disease.

Question 16

How neonate will present if infected with Mycoplasma spp, Ureaplasma urealyticum, U. parvum or Chlamydia trachomatis

Answer 16

1. bronchiolitis
2. respiratory distress (pneumonia, ARDS)
3. cough and wheeze

Question 17

If neonate is born with eye infections, they may have infection with

Answer 17

1. Neisseria gonorrhoeae

2. Chlamydia trachomatis