ANTIBIOTIC-THERAPY DETERMINES SUBCUTANEOUS ESCHERICHIA-COLI ABSCESS FORMATION AFTER CD18 INHIBITION IN RABBITS

Monoclonal antibodies (MAbs) that interrupt polymorphonuclear neutroph il (PMN)-endothelial cell adhesion can ameliorate PMN-mediated injury, including burn-induced inflammatory injury, but can also impair PMN-m ediated defense against bacterial infection. We report the effects of combined anti-adhesion and antibiotic therapy on local infectious sequ elae after subcutaneous Escherichia coli inoculation in rabbits treate d with anti-CD18 (60.3) or anti-P-selectin (PB1.3) MAb. Ampicillin or ceftriaxone were administered for 72 hours. PMN emigration was assesse d at 24 hours and local infectious sequelae at 7 days. In ampicillin/6 0.3-treated rabbits, E. coli inoculation resulted in impaired FMN emig ration and increased infectious complications, with abscesses forming at a 10,000-fold lower inoculation concentration compared with other M Ab-antibiotic treatment groups. We conclude that (1) CD18, but not P-s electin blockade interferes with. PMN emigration and host defense to s ubcutaneous E. coli, and (2) appropriate antibiotic therapy can preven t the local infectious events caused by CD18 inhibition.