title: Comparison of in vitro activities of levofloxacin, ciprofloxacin, ceftazidime, cefepime, imipenem, and piperacillin-tazobactam against aerobic bacterial pathogens from patients with nosocomial infections.
abstract: OBJECTIVE
  There is a rapid worldwide emergence of multidrug-resistant pathogens, especially in nosocomial isolates. This study compared the in vitro activities of levofloxacin, ciprofloxacin, ceftazidime, cefepime, imipenem, and piperacillin-tazobactam against 208 aerobic bacterial pathogens that caused 197 nosocomial infections in 184 patients.
  
  
  METHODS
  Antimicrobial susceptibility was evaluated by E test in accordance with the guidelines of the National Committee for Clinical Laboratory Standards.
  
  
  RESULTS
  Most (140/208, 67%) of the isolates were facultative Gram-negative bacilli. Levofloxacin and ciprofloxacin were the most effective (22/22, 100%) against oxacillin-sensitive Staphylococcus aureus. None of the antibiotics tested were found to be effective (0/25) against oxacillin-resistant S. aureus. Of the 11 isolates of Acinetobacter baumannii that were not pandrug-resistant (PDR), only 9 isolates (9/11, 81%) were sensitive to imipenem and 5 isolates (5/11, 45%) were sensitive to levofloxacin, ciprofloxacin, and ceftazidime. Another 22 isolates of A. baumannii that were PDR were completely resistant to all 6 antibiotics. The majority of isolates of Pseudomonas aeruginosa were sensitive to these 6 antimicrobial agents with 10/11 (91%) sensitive to levofloxacin and ciprofloxacin, 9/11 (83%) sensitive to ceftazidime, cefepime and piperacillin-tazobactam, and 8/11 (75%) sensitive to imipenem.
  
  
  CONCLUSIONS
  The majority of the bacterial isolates causing nosocomial infections were found to be sensitive to the 6 antibiotics tested. Bacterial isolates of nosocomial infections that were completely resistant to these 6 antibiotics were PDR A. baumannii, PDR P. aeruginosa, and oxacillin-resistant S. aureus. More potent antimicrobial agents are needed to treat infections caused by PDR A. baumannii and PDR P. aeruginosa.
authors: Division of Infectious Diseases, Chang Gung Memorial Hospital, Keelung, Taiwan.
authors: Shie Shian
authors: SS
authors: Huang
authors: Sai Cheong
authors: SC
authors: Lee
authors: Ning
authors: N
authors: Lee
authors: Lai Chu
authors: LC
authors: See
authors: Ming Han
authors: MH
authors: Tsai
authors: Wen Bin
authors: WB
authors: Shieh
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001420:Bacteria, Aerobic / Q000187:drug effects* / Q000302:isolation & purification; D001424:Bacterial Infections / Q000382:microbiology*; D003428:Cross Infection / Q000382:microbiology*; D024881:Drug Resistance, Bacterial; D024901:Drug Resistance, Multiple, Bacterial; D024841:Fluoroquinolones / Q000494:pharmacology; D006801:Humans; D008826:Microbial Sensitivity Tests; D047090:beta-Lactams / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D047090:beta-Lactams