SHIGELLA IN SENEGAL (1993-1994) - DISTRIB UTION THROUGH SEROVAR, SENSIBILITY TO ANTIBIOTICS AND VIRULENCE

This study was made on 90 strains collected from various health units. Strains were identified by biotyping and serotyping with a predominan ce of Shigella flexneri (38.9%), S. dysenteriae (A(1)A(2)) (27,8%), S. sonnei (17.8%), S. boydii (C-1,C-3) (10%). Sensibility to antibiotics and determination of MIC (agar dilution) demonstrated high resistance to tetracycline (87.8%) with MIC > 256 mg/l, penicillin (17.8%) to su lfametoxazol, and trimethoprim (24.5%). All S. sonnei were resistant t o this combination. Shigella strains were inhibited by cefozoline, cef otaxime, and imipenem. We also noticed a low resistance level to amino glycosides like gentamicin (2.3%). In addition, virulence of the strai ns, determined by the Sereny test, showed that most of them induced ke rato-conjuntivitis in guinea pigs, particularly S. boydii strains (100 %). The percentage of invasive strains obtained in vitro in Hep(2) cel ls varied from 19% for S. sonnei to 32.4% for S. dysenteriae.