[Relationship between protein binding and antimicrobial activities of antibiotics against Streptococcus pneumoniae...

Area of Science:

• Microbiology
• Infectious Diseases
• Pharmacology

Background:

• Pediatric bloodstream infections pose significant health risks.
• Streptococcus pneumoniae and Haemophilus influenzae are common bacterial pathogens in children.
• Antimicrobial resistance necessitates ongoing surveillance and evaluation of drug efficacy.

Purpose of the Study:

• To evaluate the in vitro antimicrobial activity of various antibiotics against clinical isolates of Streptococcus pneumoniae and Haemophilus influenzae.
• To compare antibiotic susceptibility testing using standard broth versus albumin-containing broth.
• To identify effective oral and intravenous antibiotic options for treating pediatric infections caused by these pathogens.

Main Methods:

• Microbroth dilution method was employed for susceptibility testing.
• Fifty S. pneumoniae and 42 H. influenzae isolates were tested.
• Testing was performed in both standard broth and broth supplemented with 4.5% albumin.

Main Results:

• Tebipenem exhibited the highest oral activity against S. pneumoniae (MIC90 ≤ 0.06 µg/mL).
• Panipenem demonstrated the highest intravenous activity against S. pneumoniae (MIC90 ≤ 0.12 µg/mL).
• Cefditoren showed the highest oral activity against H. influenzae (MIC90 ≤ 0.06 µg/mL).
• Meropenem displayed the highest intravenous activity against H. influenzae (MIC90 ≤ 0.06 µg/mL).
• Albumin-containing broth resulted in higher MIC90 values compared to standard broth, particularly for highly protein-bound antibiotics.

Conclusions:

• Tebipenem, panipenem, cefditoren, and meropenem are potent agents against the studied S. pneumoniae and H. influenzae isolates.
• The presence of albumin in testing media significantly impacts antibiotic MIC90 values, reflecting in vivo conditions.
• These findings aid in optimizing antibiotic selection for pediatric infections caused by these common pathogens.