SYNOPSIS isolation associated with the continuous widespread use of glycopeptides in a Taiwanese university hospital was observed (23). Furthermore, interhospital and nosocomial spread of some VRE clones, particularly one vanB2 E. faecium clone, or long-term persistence of multiple clones in hospitalized patients still exists (21,24). Although avoparcin has been approved for veterinary use since 1977, this agent has been banned in the farming industry since 2000 (24). Glycopeptide resistance has been found in some isolates of coagulase-negative staphylococci, particularly in S. simulans and S. warneri (25). Macrolide-Resistant Streptococci Under the increasing and highly selective pressure of mac- rolide usage in Taiwan, the prevalence of macrolide resistance and distribution of M-phenotype (mef gene-positive) among macrolide-resistant isolates vary among different streptococcal species (Figure) (26-31). More than 90% of the S. pneumoniae isolates were resistant to macrolides, and approximately two thirds exhibited high-level resistance (MLSB phenotype-erm a b Figure. A, Macrolides consumption (grams x 1,000,000) in Taiwan and the trends of erythromycin-resistant group A Streptococcus (EM-R GAS), group B Streptococcus (EM-R GBS), and S. pneumoniae in National Taiwan University Hospital from 1991 to 2000. Macrolides include intravenous and oral forms of erythromycin and oral forms of clarithromycin, roxithromycin, and azithromycin. B,. Distribution of erythromycin-resistant M-phenotype among isolates of streptococci. Other streptococci include Groups C, F, and G, and viridans group streptococci. Number in each bar indicates the percentage of erythro- mycin-resistant isolates. Number above each bar indicates the percent- age of M-phenotype among erythromycin-resistant isolates. 134 Emerging Infectious Diseases • Vol. 8, No. 2, February 2002 gene-positive) (29). However, macrolide resistance accounted for 50% to 60% of all clinical isolates of S. pyogenes, and a stepwise increase of proportion of M phenotype was clearly demonstrated (29). Streptogramin-Resistant Gram-Positive Cocci Quinupristin-dalfopristin is not available for clinical use in Taiwan; nevertheless, the incidence of resistance to this agent was high (51%) in vancomycin-resistant E. faecium (25). Three resistant E. faecium isolates were recovered from animal sources (pigs) in Taiwan. Restricted use of virginiamycin, which has been widely used in animal feed for >20 years in this country, might be required to alleviate quinupristin-dalfo- pristin resistance among bacteria from human sources (25). Multidrug-Resistant Mycobacterium tuberculosis (MDRTB) The prevalence of pulmonary tuberculosis (TB) in adults was 0.65% in 1993, and the associated death rate was 6.93 per 100,000 in 1998 (32). The overall incidence of isoniazid-resis- tant M. tuberculosis was 31.5%. The incidence of primary resistance (isolates from patients with newly diagnosed TB who had no prior history of anti-TB therapy or from patients whose anti-TB therapy was begun <2 weeks) was 12.0%; the incidence of acquired resistance (isolates from patients who had a prior history of anti-TB medication) was 63.0%. The overall incidence of MDRTB was 17.3% (primary resistance 1.6%; acquired resistance 46%) (33). An aggressive interven- tion program, such as expanded use of directly observed ther- apy, short course, is ongoing to improve the cure rate of TB and to decrease the resistance rate. Gram-Negative Bacilli H. influenzae and Moraxella catarrhalis The annual incidence of invasive H. influenzae type b dis- ease in children <5 years old was 1.6 to 1.9 per 100,000 popu- lation per year before the introduction of conjugated Hib vaccine in 1995 (34). Beta-lactamase production was found in 50% to 60% of H. influenzae and in >95% of M. catarrhalis. BRO-1 isoform accounts for 88% of all beta-lactamase pro- ducers of M. catarrhalis (16,35,36). Among amoxicillin-resis- tant H. influenzae isolates, beta-lactamase nonproducers were rare (<2%) (16). A continuing upsurge of H. influenzae iso- lates resistant to macrolide (30%) and to trimethoprim-sul- famethoxazole (50%) during the last decade has become evident (16,35). Enterobacteriaceae The proportion of isolates of K. pneumoniae exhibiting the ESBL phenotype has increased progressively from 3.4% in 1993 to 10.3% in 1997 in NTUH (37). Approximately one fifth of the ESBL-producing K. pneumoniae were also resis- tant to ciprofloxacin (37). From 1998 through 2000, several reports from different hospitals showed that ESBL production