Changing trends in antimicrobial resistance of major bacterial pathogens, 1985–2005: A study from a medical center in northern Taiwan

Abstract

Antimicrobial resistance is a major health problem worldwide. We evaluated the antimicrobial resistance trends of 16 major bacterial pathogens at a tertiary medical center in northern Taiwan. We conducted a retrospective review of annual summary documents for antimicrobial susceptibility of clinically isolated gram-positive and gram-negative bacteria from 1985 to 2005. The numbers of isolates and susceptibilities were calculated for three 7-year periods: first period, 1985-1991; second period, 1992-1998; and the third period, 1999-2005. During the 21-year period, 219,715 bacterial pathogens were identified. A significant increase in incidence over time was found for methicillin-resistant Staphylococcus aureus, methicillin-resistant S epidermidis, penicillin-nonsusceptible Streptococcus pneumoniae, erythromycin-resistant S pneumoniae, vancomycin-resistant enterococci, cefotaxime/ceftriaxone-resistant Escherichia coli and Klebsiella pneumoniae, and imipenem-resistant Acinetobacter baumannii. Additionally, a significant increase in ciprofloxacin resistance rates over time from 1996 to 2005 was noted for E coli, Enterobacter cloacae, and A baumannii (through 1997 to 2005). However, a significant decrease in erythromycin resistance rate with time from 1999 to 2005 was found for Groups A and B streptococci, non-A, B, D streptococci, and S pneumoniae. Resistance to antimicrobial agents increased rapidly in the past two decades in Taiwan and has become very common in major bacterial pathogens. Continuous enforcement of policies to limit use of antimicrobial agents and active surveillance of antimicrobial resistance through a nationwide system are both warranted.