Changing patterns of susceptibilities of blood, urinary and respiratory pathogens in Hong Kong

The incidence and antimicrobial susceptibility of organisms isolated from blood, urine and respirator); specimens at a teaching hospital in Hong Kong were studied retrospectively from 1986-1993. The incidence of Gram-positive bacteraemia, particularly coagulase-negative staphylococci (CNS), increased significantly from 33.6 to 47.3% (P<0.001) while that of Gram-negative bacteraemia fell from 60.0 to 47.0% (P<0.001). Among blood isolates, methicillin resistance of CNS increased from 17.0 to 58.0% (P<0.001) and cefuroxime resistance of Enterobacter spp. increased from 21.0 to over 50% (P<0.01). Among urinary isolates, cefuroxime resistance of klebsiella spp. (11.0 to 24.0%, P<0.001) and Enterobacter spp. (32.0 to 75.0%, P<0.001) increased. Nalidixic acid resistance among Gram-negative urinary isolates, except Proteus mirabilis, rose by three- to sixfold. For Streptococcus pneumoniae, isolated from the respiratory tract, penicillin resistance increased dramatically (2 to 18%, P<0.001). For respiratory isolates of Haemophilus influenzae, ampicillin resistance increased from 17.0 to 29.0% (P<0.001). These data are useful in guiding empirical treatment of nosocomial infections.