In vitro bactericidal activities and morphologic changes in Escherichia coli and Bacteroides fragilis by cephalosporins

In vitro bactericidal activities of antimicrobial agents and morphologic changes on Prevotella bivia

Prevotella bivia is common in pelvic inflammatory diseases. Parenteral antimicrobial agents have been widely used against those infections. We investigated the bactericidal activities of three cephalosporins, i.e. cefluprenam (CFLP), ceftazidime (CAZ) and cefotaxime (CTX) and of two other antimicrobial agents, i.e. clindamycin (CLDM) and imipenem (IPM) against P. bivia. We also investigated the in vitro morphological changes induced by these agents in P. bivia. Cephalosporins exhibited bactericidal activities against P. bivia and induced time- and concentration-dependent morphological changes in P. bivia (filamentation). CLDM and IPM also had bactericidal activities, but induced different morphologic alterations: formation of spheroblasts and lysis. These results confirm the fact that each antimicrobial agent has characteristic aspects.

In vitro bactericidal activities of a new oral cephalosporin, E1100, and morphologic changes on Escherichia coli

Escherichia coli is one of the most common aerobic bacteria in pelvic inflammatory diseases. Oral cephalosporins have been widely used against those infections. We investigated in vitro morphologic changes induced on E. coli by a new oral cephalosporin, E1100, and its bactericidal activity on this organism. Morphologic changes were observed by electron microscopy. E1100 induced morphologic changes (filamentation) and exerted a bactericidal activity on E. coli. The filamentation induced by E1100 was time and concentration dependent.