Related Experiment Videos
Antimicrobial therapy of experimental group B streptococcal infection in mice
Abstract:
Group B beta-hemolytic streptococci (GB-BHS) frequently cause severe infection in newborns. Previous in vitro studies showed accelerated killing of GB-BHS by ampicillin plus gentamicin as compared with ampicillin alone. To extend the in vitro observations, mice were infected experimentally with GB-BHS and treated with gentamicin plus ampicillin or ampicillin alone. Untreated mice died within 10 to 48 h. Compared with treatment with ampicillin alone, ampicillin-and-gentamicin therapy resulted in improved survival when the antibiotics were given in established infection or as a single dose at the time of infection. Ampicillin and gentamicin accelerated the clearing of bacteremia as compared with treatment with ampicillin alone. In view of these findings, the therapy of GB-BHS infection in newborns and other patients should be reconsidered in that a combination of ampicillin or penicillin G plus gentamicin might be superior to the use of ampicillin or penicillin G alone.
Insights
Combining ampicillin with gentamicin significantly improves survival and bacterial clearance in Group B beta-hemolytic streptococci (GB-BHS) infections in mice compared to ampicillin alone. This suggests a potential superior treatment strategy for neonatal GB-BHS infections.
Area of Science:
- Microbiology
- Infectious Diseases
- Pharmacology
Background:
- Group B beta-hemolytic streptococci (GB-BHS) are a major cause of severe neonatal infections.
- Previous in vitro studies indicated enhanced bacterial killing with ampicillin plus gentamicin versus ampicillin monotherapy.
Purpose of the Study:
- To evaluate the in vivo efficacy of ampicillin plus gentamicin compared to ampicillin alone for treating experimental GB-BHS infections.
- To determine the impact of combination therapy on survival rates and bacterial clearance in a murine model.
Main Methods:
- Mice were experimentally infected with GB-BHS.
- Treatment groups included ampicillin alone, ampicillin plus gentamicin, and untreated controls.
- Survival rates and bacteremia levels were monitored.
Main Results:
- Untreated mice exhibited high mortality within 10-48 hours.
- Ampicillin-gentamicin combination therapy demonstrated improved survival rates compared to ampicillin alone, regardless of treatment timing (established infection or single dose).
- The combination therapy significantly accelerated the clearance of bacteremia.
Conclusions:
- Combination therapy with ampicillin or penicillin G plus gentamicin may offer superior outcomes for GB-BHS infections compared to beta-lactam monotherapy.
- Clinical reconsideration of current treatment guidelines for GB-BHS infections is warranted.
- This combination therapy holds promise for treating neonatal and other patient populations susceptible to GB-BHS.