Comparison of serum bactericidal activity among three antimicrobial combinations

Area of Science:

• Infectious Diseases
• Hematology
• Pharmacology

Background:

• Febrile episodes in granulocytopenic cancer patients pose a significant clinical challenge.
• Empiric antibiotic therapy is crucial for managing infections in this immunocompromised population.

Purpose of the Study:

• To evaluate the in vitro serum bactericidal activity of three antimicrobial combinations against common pathogens in febrile granulocytopenic cancer patients.
• To determine the optimal antibiotic regimen for empiric therapy.

Main Methods:

• Prospective randomized antibiotic trial involving 105 febrile granulocytopenic cancer patients.
• Serum samples from 32 patients were tested for bactericidal activity against Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, and Staphylococcus aureus.
• Three antibiotic regimens were compared: ticarcillin plus cephalothin (T+C), ticarcillin plus gentamicin (T+G), and cephalothin plus gentamicin (C+G).

Main Results:

• All three regimens showed high bactericidal activity against Staphylococcus aureus and Escherichia coli.
• Ticarcillin-containing regimens (T+G, T+C) demonstrated poor activity against Pseudomonas aeruginosa, while cephalothin plus gentamicin (C+G) showed no measurable activity.
• Cephalothin plus gentamicin (C+G) was most effective against Klebsiella pneumoniae, whereas T+C showed the least activity.

Conclusions:

• Ticarcillin plus gentamicin (T+G) exhibits favorable serum bactericidal activity against key pathogens.
• The findings support the use of T+G as an effective initial empiric therapy for febrile episodes in granulocytopenic cancer patients.