Increased frequency of detection of multi-drug resistant strains of Streptococcus pneumoniae in the United States over 10 years: results of the Alexander project

The Alexander Project is a global study, launched in 1992, to monitor the sensitivity of the major agents responsible for community-acquired lower respiratory tract infections to various antibacterial drugs and to identify trends in the development and spread of resistance to antibiotics.

A study of the sensitivity of strains of Streptococcus pneumoniae isolated in the United States from 1992 to 2001 within the framework of this project showed that the resistance of this microorganism to penicillin and to erythromycin increased during the study period by 3.9 and 4.5 times, amounting to 20.7% and 27.9% respectively.

The resistance associated with the two drugs increased by 4.9 times (up to 15.3%). For example, in 1992, 57.1% of all penicillin-resistant isolates were also resistant to erythromycin, while by 2001 this indicator had increased to 75.8%. Resistance to a single drug increased slightly, from 8% in 1992 to 12% in 2001, while resistance to more than one drug increased by 4.3 times, from 6.4% in 1992 to 27 , 8% of all strains in 2001

Thus, there has been a steady increase in the incidence of multidrug-resistant pneumococci in the United States. Three-quarters of penicillin-resistant strains were multidrug-resistant, and the increase in the detection rate of multidrug-resistant strains exceeded that of monoresistance.