For critical patients with A. baumannii complex infection, ventilator-associated pneumonia in particular, the selective pressure from prior use of broad-spectrum antibiotics for 5 days or more increased risk of subsequent imipenem-resistant A. baumannii complex bacteremia. To reduce mortality, rapid identification of imipenem-resistant A. baumannii complex and early initiation of appropriate antimicrobial therapy in these high-risk patients are crucial.

This multinational study from Asia revealed that reduced susceptibility to ciprofloxacin (MIC, 0.125 to 1 g/ml) in nontyphoid Salmonella isolates was common in Taiwan (48.1%) and Thailand (46.2%) and in S. enterica serotype Choleraesuis (68.8%) and S. Virchow (75.0%) from all countries. Reduced susceptibility to ceftriaxone (MIC, 2 to 8 g/ml) remained uncommon in Asia, except in Taiwan (38.0%) or in S. Typhimurium (25.0%) from all countries.Nontyphoid Salmonella bacteria, with more than 2,500 serotypes, usually cause diarrheal diseases in humans that may be complicated by extraintestinal infections, such as bacteremia, meningitis, and osteomyelitis (11). Resistance to antimicrobial agents, including fluoroquinolones and expanded-spectrum cephalosporins, has been a serious problem worldwide. Nontyphoid salmonellosis has been rampant in Asia (7); however, data on the antimicrobial susceptibilities, as well as the prevalence, of various serotypes in many Asian countries after 2000 have been lacking.During 2003 to 2005, 400 clinical isolates of nontyphoid Salmonella bacteria were randomly collected from 11 medical centers in seven Asian countries (Table 1) and transported to the central laboratory in Samsung Medical Center, Seoul, Korea, for serogrouping and serotyping using O and H antisera, respectively (Difco Laboratories, Detroit, MI). Susceptibilities to ciprofloxacin, tetracycline, ceftriaxone, ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole were determined by a broth microdilution method, and the results were interpreted according to the breakpoints for MICs suggested by the NCCLS (10). For statistical analysis, isolates in the "intermediate" category were deemed "resistant" in this study. Concomitant resistance to at least three of the six antibiotics tested was defined as multidrug resistance (MDR). Isolates with ciprofloxacin MICs of 0.125 to 1 g/ml were defined as having "reduced susceptibility" to ciprofloxacin (9). Similarly, "reduced susceptibility" to ceftriaxone was defined as isolates showing ceftriaxone MICs of 2 to 8 g/ml (14). These definitions were proposed in previous reports to reflect the clinical therapeutic responses (9, 14). The 2 test and Student's t test were used to determine the significance of differences, and a P value of Ͻ0.05 was considered statistically significant.A total of nine serogroups (B, C1, C2, D, E, G, I, K, and M) and 82 serotypes were identified among the isolates tested. Serogroups B (34.8%) and D (25.0%) were the two leading serogroups in all areas except Philippines, where serogroup E (25 isolates, 53.2%) was most prevalent. The distribution of major serotypes among the countries is shown in Table 1. Overall, S. enterica serotype Enteritidis and S. Typhimurium were the two most-prevalent serotypes except in Philippines, Singapore, and Thailand, where S. Weltevreden was either the most-or second-most-prevalent serotype. In Sri Lanka and Thailand, the most-prevalent serotypes were S. Agona and S. Stanley, respectively. S. Choleraesuis was relatively mor...

The ASP with a culture-guided de-escalation of antibiotics successfully reduced length of stay, mortality, the cost of antimicrobials, DDDs, and antimicrobial resistance rate, and that is highly recommended for local hospitals.