Figure 1. Algorithm for prevention of early-onset group B streptococcal (GBS) disease in neonates, using prenatal screening at 35-37 weeks’ gestation
*If membranes ruptured at <37 weeks’ gestation, and the mother has not begun labor, collect group B streptococcal culture and either a) administer antibiotics until cultures are completed and the results are negative or b) begin antibiotics only when positive cultures are available. No prophylaxis is needed if culture obtained at 35-37 weeks’ gestation was negative.
† Broader spectrum antibiotics may be considered at the physician’s discretion, based on clinical indications.
Figure 2. Algorithm for prevention of early-onset of group B streptococcal (GBS)disease in neonates, using risk factors
*If membranes ruptured at <37 weeks’ gestation, and the mother has not begun labor, collect group B streptococcal culture and either a) administer antibiotics until cultures are completed and the results are negative or b) begin antibiotics only when positive cultures are available.
†Broader spectrum antibiotics may be considered at the physician’s discretion, based on clinical indications.
Figure 3. Algorithm for management of a neonate born to a mother who received intrapartum antimicrobial prophylaxis (IAP) for prevention of early-onset group B streptococcal (GBS) disease
Table 1. MIC50 and MIC90 Antimicrobial Susceptibility Concentrations for Group B Streptococci
| Antimicrobial Agent | MIC (microgram/ml) | ||
| Range | MIC50 | MIC90 | |
|
Ampicillin |
0.12-0.25 |
0.25 |
0.25 |
|
Cefamandole |
< 0.03-0.5 |
0.06 |
0.12 |
|
Cefoxitin |
0.5-8.0 |
4.0 |
4.0 |
|
Cefuroxime |
<0.03-1.0 |
0.06 |
0.06 |
|
Cephradine |
0.25-4.0 |
2.0 |
2.0 |
|
Cephalexin |
0.5-8.0 |
4.0 |
4.0 |
|
Cephalothin |
0.06-0.5 |
0.25 |
0.25 |
|
Ceftriaxone |
0.06-0.12 |
0.12 |
0.12 |
|
Cefotaxime |
0.02-0.12 |
0.12 |
0.12 |
|
Cefoperazone |
0.12-0.5 |
0.25 |
0.5 |
|
Ceftazidime |
0.12-0.5 |
0.25 |
0.5 |
|
Clindamycin |
<0.03-0.25 |
0.06 |
0.06 |
|
Carbenicillin |
0.5-1 |
1 |
1 |
|
Chloramphenicol |
1.0-4.0 |
2.0 |
4.0 |
|
Colistin |
8.0->32.0 |
>32.0 |
>32.0 |
|
Doxycycline |
0.12-32.0 |
16.0 |
16.0 |
|
Erythromycin |
<0.01-0.25 |
0.06 |
0.06 |
|
Gentamicin |
1.0>32.0 |
16.0 |
16.0 |
|
Kanamycin |
8.0->32.0 |
>32.0 |
>32.0 |
|
Lincomycin |
0.03-0.25 |
0.12 |
0.12 |
|
Methicillin |
0.5-16.0 |
2.0 |
2.0 |
|
Minocycline |
0.25-32.0 |
16.0 |
32.0 |
|
Mezlocillin |
0.12-0.25 |
0.12 |
0.25 |
|
Moxalactam |
2-8 |
8 |
8 |
|
Neomycin |
4.0>32.0 |
32.0 |
>32.0 |
|
Nalidixic Acid |
>32.0 |
>32.0 |
>32.0 |
|
Nitrofurantoin |
8.0-32.0 |
16.0 |
32 |
|
Penicillin |
<0.01-0.12 |
0.06 |
0.06 |
|
Piperacillin |
0.25-0.5 |
0.5 |
0.5 |
|
Sulfa-trimethoprim |
1.2/0.06-9.5/0.5 |
4.8/0.25 |
4.8/0.25 |
|
Ticarcillin |
1-2 |
2 |
2 |
|
Tetracycline |
0.12->32.0 |
32.0 |
32.0 |
|
Vancomycin |
0.5-2.0 |
0.5 |
0.5 |
Table 2. Antimicrobial Regimens Recommended For Treatment of Group B Streptococcal Infections
in Neonates and Young Infants
|
Site of Infection |
Age |
Drug |
Dose Per Day (Intravenous) |
Duration |
|
Bacteremia without meningitis |
All |
Ampicillin plus gentamicin |
150-200mg/kg 7.5 mg/kg |
Initial treatment before culture results (48-72 hr) |
|
|
|
Penicillin G |
200,000 units/kg |
Complete a total treatment course of 10 days |
|
Meningitis
|
< 7 days |
Ampicillin |
200-300 mg/kg/day in 3 divided doses |
Initial treatment until CSF is sterile |
|
|
|
Gentamicin |
5 mg/kg in 2 divided doses |
|
|
|
< 7 days |
Penicillin G |
250,000-400,000 u/kg/day in 3 divided doses |
Complete a minimum total treatment course of 21 days |
|
|
> 7 days |
Ampicillin |
300-400 mg/kg/day in 4-6 divided doses |
Initial treatment until CSF is sterile |
|
|
|
Gentamicin |
7.5 mg/kg in 3 divided doses |
|
|
|
> 7 days |
Penicillin G |
500,000 u/kg/day in 4 divided doses |
Complete a minimum total treatment course of 21 days |
|
Septic arthritis |
All |
Penicillin G |
200,000 units/kg |
2-3 wk |
|
Osteomyelitis |
All |
Penicillin G |
200,000 units/kg |
3-4 wk |
|
Endocarditis |
All |
Penicillin G |
400,000 unit/kg |
4 wks-6 wks |