Comparative Evaluation of Orally Active Antibiotics against Community-Acquired Pathogens: a Multi-Center Study in Five Mediterranean Countries

In 5 Mediterranean countries 7902 pathogens, all isolated in 1992 and 1993 from community-acquired infections, were studied for susceptibility to the following orally active antibiotics: penicillin G, ampicillin, ampicillin + sulbactam, amoxycillin + clavulanic acid (both 2:1 ratio), cefalexin, cefaclor, cefuroxime, cefetamet, doxycycline and erythromycin. Ten centers in Italy, 4 centers in Greece, 3 centers in Spain, and 1 center in Lebanon and Saudi Arabia contributed to this study; all centers used performed standardized microtiter panels (Sceptor, BBL, Heidelberg, FRG). The most frequently isolated pathogens were Escherichia coli (n = 1267), Proteus mirabilis (n = 843), Klebsiella pneumoniae (n = 771), enteric Salmonella spp. (n = 629), Enterobacter cloacae (n = 486), Citrobacter freundii (n = 383), Streptococcus agalactiae (n = 346), Haemophilus influenzae (n = 298), Streptococcus pyogenes (n = 294), Streptococcus pneumoniae (n = 246), Klebsiella oxytoca (n = 243), and Shigella spp. (n = 185). Statistical analysis was performed for each of the above countries and for all pooled data available. The penicillin antibiotics were the most active compounds against the gram-positive cocci, exceeding the MIC90 values 2- to 8-fold over all cephalosporins. Regarding the gram-negatives (above all Klebsiella spp.) cefetamet was by far the most active compound (MIC90 = 1 mg/l). Regarding the percentage of resistant isolates, there were no striking discrepancies between the centers and countries involved in this study. There was, however, complete cross-resistance in penicillin-resistant S. pneumoniae isolates (MIC90 = 2 mg/l). By far the majority of the penicillin-resistant pneumococci showed additional resistance to doxycycline and erythromycin.(ABSTRACT TRUNCATED AT 250 WORDS)