Treatment of anthrax infection with combination of ciprofloxacin and antibodies to protective antigen of Bacillus anthracis

FEMS Immunol Med Microbiol. 2004 Jan 15;40(1):71-4. doi: 10.1016/S0928-8244(03)00302-X.


Currently there is no effective treatment for inhalational anthrax beyond administration of antibiotics shortly after exposure. There is need for new, safe and effective treatments to supplement traditional antibiotic therapy. Our study was based on the premise that simultaneous inhibition of lethal toxin action with antibodies and blocking of bacterial growth by antibiotics will be beneficial for the treatment of anthrax. In this study, we tested the effects of a combination treatment using purified rabbit or sheep anti-protective antigen (PA) antibodies and the antibiotic ciprofloxacin in a rodent anthrax model. In mice infected with a dose of Bacillus anthracis Sterne strain corresponding to 10 LD(50), antibiotic treatment with ciprofloxacin alone only cured 50% of infected animals. Administration of anti-PA IgG in combination with ciprofloxacin produced 90-100% survival. These data indicate that a combination of antibiotic/immunoglobulin therapy is more effective than antibiotic treatment alone in a rodent anthrax model.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Anthrax / drug therapy
  • Anthrax / therapy*
  • Anti-Infective Agents / therapeutic use
  • Antibodies, Bacterial / administration & dosage
  • Antibodies, Bacterial / therapeutic use*
  • Antigens, Bacterial*
  • Bacillus anthracis / drug effects
  • Bacillus anthracis / immunology
  • Bacterial Toxins / immunology*
  • Ciprofloxacin / therapeutic use*
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Immunization, Passive*
  • Mice
  • Rabbits
  • Recombinant Proteins / immunology
  • Sheep


  • Anti-Infective Agents
  • Antibodies, Bacterial
  • Antigens, Bacterial
  • Bacterial Toxins
  • Recombinant Proteins
  • anthrax toxin
  • Ciprofloxacin