[Plague in Algeria: about five strains of Yersinia pestis isolated during the outbreak of June 2003].

In this study, we isolated and identified five strains of Yersinia pestis during an epidemic occurred in west of Algeria in June 2003. The bacteriological identification was confirmed by bacteriophage susceptibility. All these strains belonged to the biovar Orientalis (they did not ferment glycerol but did reduce nitrate to nitrite) which caused the current pandemic. The in vitro activities of antimicrobial agents used to treat plague and recommended for prophylaxis, showed that they are active against all strains. The comparison of these strains by plasmid profile analyse demonstrated that all isolates had three plasmids: 110, 70 and 9.5 kb, which are present in Y. pestis strains.