Gemifloxacin: survival of the fittest.

The incidence of penicillin resistance in pneumococci is increasing in the USA, having risen from <5% before 1989 to >35% in 1997. There has also been a shift in the ratio of intermediate to high-level resistance from 3 or 4:1 to 2 or 1:1. Multidrug resistance and resistance to macrolides and fluoroquinolones in pneumococci is also a matter of concern. The implications for empirical treatment of respiratory tract infections are considerable. The potential of quinolones with activity against respiratory pathogens including pneumococci must be preserved by careful antimicrobial prescribing.