To assess the species distribution and epidemiologic trends of nontuberculous mycobacteria, we examined isolates from patients in Taiwan. During 2000–2008, the proportion increased significantly from 32.3% to 49.8%. Associated disease incidence increased from 2.7 to 10.2 cases per 100,000 patients. Mycobacterium avium complex and M. abscessus were most frequently isolated.

This study reports data on the susceptibilities to five commonly used antianaerobic agents of five clinically frequently encountered anaerobes from 2000 to 2007 and to Bacteroides fragilis isolates causing nosocomial infections from 1990 to 2006. There was a trend of decreasing susceptibilities of these anaerobes to ampicillin-sulbactam, cefmetazole, chloramphenicol, and clindamycin with time during the study period. The rates of susceptibility to clindamycin and cefmetazole for all clinical isolates of Bacteroides fragilis isolates were higher than those of isolates associated with nosocomial infections. The MICs of 207 anaerobic blood isolates collected in 2006 to 14 antimicrobial agents were determined by the agar dilution method. The rates of nonsusceptibility to imipenem and meropenem were 7% and 12% for B. fragilis isolates ( n = 60), 7% and 3% for Bacteroides thetaiotamicron isolates ( n = 30), 4% and 4% for Fusobacterium species ( n = 27), 6% and 0% for Prevotella species ( n = 16), 15% and 0% for Clostridium species ( n = 28), and 0% and 0% for Peptostreptococcus species ( n = 32). The rates of susceptibility to moxifloxacin were 90% for B. fragilis isolates, 87% for B. thetaiotaomicron isolates, 81% for Fusobacterium species, 75% for Prevotella species, 93% for Clostridium species, and 78% for Peptostreptococcus species. Thirty-six percent of Clostridium species and 12% of Peptostreptococcus species were not susceptible to metronidazole. Comparison of the data with the data from a previous survey from the same institute in 2002 revealed higher rates of nonsusceptibility to carbapenems, especially for B. fragilis , Fusobacterium species, and Prevotella species isolates. The high rates of nonsusceptibility to commonly used antianaerobic agents mandate our attention, and periodic monitoring of the trend of the resistance is crucial.

Since few therapeutic options exist for extensively drug resistant Acinetobacter baumannii, an emerging threat in ICUs worldwide, and comparative prospective studies of colistin-based combination therapies are lacking, our objective was to compare the outcomes of patients with extensively drug-resistant A. baumannii bacteremia, treated with colistin-carbapenem and colistin-tigecycline combinations. Prospective, observational, multicenter study. Adults with extensively drug-resistant A. baumannii bacteremia were prospectively followed from 2010 to 2013 at three hospitals in Taiwan. Extensively drug-resistant A. baumannii was defined as A. baumannii (genospecies 2) nonsusceptible to all drug classes except for colistin and tigecycline, and standard combination therapy as use of parenteral colistin-carbapenem or colistin-tigecycline for at least 48 hours after onset of bacteremia. Primary outcome measure was 14-day mortality. Of the 176 episodes of extensively drug-resistant A. baumannii bacteremia evaluated, 55 patients with a median (interquartile range) age of 62 years (44–79 yr) and Sequential Organ Failure Assessment score of 9 (5–13) points received standard combination therapy: colistin-tigecycline in 29 patients and colistin-carbapenem in 26. Crude 14-day and in-hospital mortality rates for patients receiving colistin-tigecycline versus patients receiving colistin-carbapenem were 35% versus 15% (p = 0.105) and 69% versus 50% (p = 0.152), respectively. Breakthrough extensively drug-resistant A. baumannii bacteremia under steady state concentrations of combination therapy for colistin-tigecycline group was 18% and for colistin-carbapenem group was 0% (p = 0.059). Eleven patients (20.0%) developed nephrotoxicity. After adjusting for age, sex, comorbidity, initial disease severity, loading colistin dose, polymicrobial infection, and primary infection site, excess 14-day mortality was associated with the use of colistin-tigecycline in the subgroup with tigecycline minimum inhibitory concentration greater than 2 mg/L compared with the use of colistin-carbapenem (hazard ratio, 6.93; 95% CI, 1.61–29.78; p = 0.009). Increased 14-day mortality was associated with colistin-tigecycline therapy given tigecycline minimum inhibitory concentration greater than 2 mg/L compared with colistin-carbapenem therapy for extensively drug-resistant A. baumannii bacteremia.