Mycobacterium tuberculosis among the gram-positive patho- gens, and Haemophilus influenzae, Escherichia coli, Kleb- siella pneumoniae, Enterobacter species, Salmonella species, Campylobacter species, Pseudomonas aeruginosa, and Acine- tobacter baumannii among the gram-negative pathogens. Resistance rates included in this review reflect both intermedi- ate and fully resistant populations. Table 2 summarizes the prevalence of antimicrobial resistance among clinical isolates (12 hospitals, including NTUH) and nosocomial isolates (from NTUH only) of some selected bacterial species. The ranges in numbers of clinical isolates of select bacteria (Table 2) recov- ered from these hospitals were as follows: Staphylococcus aureus, 1,889 to 7,516 isolates; beta-hemolytic streptococci, 335 to 1,102; S. pneumoniae, 138 to 461; enterococci, 509 to 3,676; H. influenzae, 427 to 602; E. coli, 1,734 to 9,553; K. pneumoniae, 950 to 3,226; E. cloacae, 427 to 1,426; nonty- phoid Salmonella, 94 to 626; P. aeruginosa, 1,741 to 4,896; and A. baumannii, 896 to 2,434. Gram-Positive Bacteria MRSA MRSA was first documented in Taiwan in the early 1980s (8). Since then, there has been a remarkable increase in preva- lence of MRSA in nosocomial infections (from 26.7% in 1990 to 75% to 84% in 1998-2000) (9). Several dominant clones have been documented in hospitals (9). The prevalence of MRSA in community-acquired infections remains unclear, although the incidence of MRSA among patients of outpatient departments is estimated to be 40% (1). Data from a survey of >5,000 clinical isolates of S. aureus at the NTUH from Janu- ary 1999 to June 2001 using brain-heart-infusion agar plus 4 mg/L of vancomycin showed results negative for vancomycin- intermediate or -resistant strains. PNSSP and Multidrug-Resistant Streptococcus pneumoniae (MDRSP) The overall prevalence of clinical isolates of PNSSP in 1999-2000 was 60% to 80%, including 20% to 30% penicillin- intermediate and 40% to 50% penicillin-resistant strains (10- 16). This prevalence of PNSSP was slightly lower than that in Korea and higher than that in most other geographic areas (15,16). All PNSSP were resistant to multiple antibiotics (13,16). This resistance was higher among nasopharyngeal isolates from children (12). Approximately 60% of the PNSSP isolates were also not susceptible to extended-spectrum cepha- losporins and carbapenems (13). Most of these PNSSP belong to serotypes 23F, 19F, 6B, and 14 (13,15). Wide dissemination of multiple high-level penicillin-, extended-spectrum cepha- losporin-, and macrolide-resistant clones as well as the Spain 23F clone contributes to the high rates of resistance to these drugs in clinical isolates of S. pneumoniae (14,17). Only one clinical isolate was reported to be resistant to fluoroquinolones (18). SYNOPSIS Table 2. Prevalence of antimicrobial resistance in selected bacteria (all clinical isolates) isolated from 12 major hospitals, including National Taiwan University Hospital (NTUH), in Taiwan in 2000 and in all clinical isolates and isolates causing nosocomial infections from NTUH in 2000a % of isolates 2,000 (12 hospitals) (clinical) 2,000 (NTUH) (clinical/nosoco- mial) aSusceptibility of these bacteria was determined by the standard disk-diffusion method. VRE and Glycopeptide-Resistant Staphylococci The first clinical isolate of Van-A-phenotype VRE (E. faecalis) was found in 1995 (19). Since then, isolation of VRE remains rare and accounts for <3% of all clinical isolates of enterococci (20,21). The proportion of Enterococcus hospital isolates resistant to vancomycin in Taiwan is low compared with those in North America and Europe (22), a finding that needs further investigation. However, an increase in VRE Emerging Infectious Diseases • Vol. 8, No. 2, February 2002 133 Resistant pathogen Methicillin-resistant Staphylo- coccus aureus Erythromycin-resistant beta- hemolytic streptococci Penicillin-nonsusceptible Strep- tococcus pneumoniae Erythromycin-resistant S. pneu- moniae Gentamicin-resistant (high- level) enterococci Vancomycin-resistant entero- cocci Ampicillin-resistant H. influen- zae Cefotaxime-resistant Escheri- chia coli Ciprofloxacin-resistant E. coli Cefotaxime-resistant Kleb- siella pneumoniae Ciprofloxacin-resistant K. pneumoniae Cefotaxime-resistant E. cloacae Ampicillin-resistant non- typhoid Salmonella Cefotaxime-resistant non- typhoid Salmonella Quinolone resistant non-typhi Salmonella Ceftazidime-resistant Pseudomonas aeruginosa Imipenem-resistant P. aerugi- nosa Ciprofloxacin-resistant P. aeruginosa Imipenem-resistant Acineto- bacter baumannii Ciprofloxacin-resistant A. bau- mannii 53-83 30-51 60-84 67-100 36-54 1-3 45-73 5-19 11-33 4-34 5-33 36-68 44-69 1-4 0-16 4-21 3-16 10-36 0-19 54-74 65/74 34/− 77/− 89/− 48/54 3/2 61/− 12/19 20/29 9/18 9/16 45/49 56/− 2/− 0/− 13/10 14/10 15/10 19/16 54/42