Pseudomonas aeruginosa and Acinetobacter baumannii are the most prevalent nonfermentative bacterial species isolated from clinical specimens of hospitalized patients. A surveillance study of 65 laboratories in the United States from 1998 to 2001 found >90% of isolates of P. aeruginosa from hospitalized patients to be susceptible to amikacin and piperacillin-tazobactam; 80 to 90% of isolates to be susceptible to cefepime, ceftazidime, imipenem, and meropenem; and 70 to 80% of isolates to be susceptible to ciprofloxacin, gentamicin, levofloxacin, and ticarcillin-clavulanate. From 1998 to 2001, decreases in antimicrobial susceptibility (percents) among non-intensive-care-unit (non-ICU) inpatients and ICU patients, respectively, were greatest for ciprofloxacin (6.1 and 6.5), levofloxacin (6.6 and 3.5), and ceftazidime (4.8 and 3.3). Combined 1998 to 2001 results for A. baumannii isolated from non-ICU inpatients and ICU patients, respectively, demonstrated that >90% of isolates tested were susceptible to imipenem (96.5 and 96.6%) and meropenem (91.6 and 91.7%); fewer isolates from both non-ICU inpatients and ICU patients were susceptible to amikacin and ticarcillin-clavulanate (70 to 80% susceptible); and <60% of isolates were susceptible to ceftazidime, ciprofloxacin, gentamicin, or levofloxacin. From 1998 to 2001, rates of multidrug resistance (resistance to at least three of the drugs ceftazidime, ciprofloxacin, gentamicin, and imipenem) showed small increases among P. aeruginosa strains isolated from non-ICU inpatients (5.5 to 7.0%) and ICU patients (7.4 to 9.1%). From 1998 to 2001, rates of multidrug resistance among A. baumannii strains isolated from non-ICU inpatients (27.6 to 32.5%) and ICU patients (11.6 to 24.2%) were higher and more variable than those observed for P. aeruginosa. Isolates concurrently susceptible, intermediate, or resistant to both imipenem and meropenem accounted for 89.8 and 91.2% of P. aeruginosa and A. baumannii isolates, respectively, studied from 1998 to 2001. In conclusion, for aminoglycosides and most ␤-lactams susceptibility rates for P. aeruginosa and A. baumannii were constant or decreased only marginally (<3%) from 1998 to 2001. Greater decreases in susceptibility rates were, however, observed for fluoroquinolones and ceftazidime among P. aeruginosa isolates.

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Multidrug-resistant MRSA is increasing in serious ocular infections. Based on the rate of increase in the TSN database, MRSA cultures from serious ocular infections could be more common than methicillin-susceptible S aureus within 2 to 3 years. Large-scale national surveillance programs are needed to monitor in vitro antimicrobial resistance trends in ocular isolates.

Telavancin is an investigational, rapidly bactericidal lipoglycopeptide antibiotic that is being developed to treat serious infections caused by gram-positive bacteria. A baseline prospective surveillance study was conducted to assess telavancin activity, in comparison with other agents, against contemporary clinical isolates collected from 2004 to 2005 from across the United States. Nearly 4,000 isolates were collected, including staphylococci, enterococci, and streptococci (pneumococci, beta-hemolytic, and viridans). Telavancin had potent activity against Staphylococcus aureus and coagulase-negative staphylococci (MIC range, 0.03 to 1.0 g/ml), independent of resistance to methicillin or to multiple agents. Telavancin activity was particularly potent against all streptococcal groups (MIC 90 s, 0.03 to 0.12 g/ml). Telavancin had excellent activity against vancomycin-susceptible enterococci (MIC 90 , 1 g/ml) and was active against VanB strains of vancomycinresistant enterococci (MIC 90 , 2 g/ml) but less active against VanA strains (MIC 90 , 8 to 16 g/ml). Telavancin also demonstrated activity against vancomycin-intermediate S. aureus and vancomycin-resistant S. aureus strains (MICs, 0.5 g/ml to 1.0 g/ml and 1.0 g/ml to 4.0 g/ml, respectively). These data may support the efficacy of telavancin for treatment of serious infections with a wide range of gram-positive organisms.Antibiotic resistance in gram-positive bacteria is a continuing health care problem, both in hospitals and in the community. Telavancin is a novel, once-daily, intravenously administered lipoglycopeptide that is being developed to treat serious infections caused by gram-positive bacteria. It has shown promising results in patients with complicated skin and skin structure infections (SSSIs) (i.e., cellulitis, major abscess, infected wound/ulcer, or burn complicated by a requirement for surgical intervention and/or involvement of deeper tissues), including those infected with methicillin-resistant Staphylococcus aureus (MRSA) (19,20,21). A U.S. Food and Drug Administration New Drug Application has been filed for telavancin based on two completed phase 3 clinical trials for the treatment of complicated SSSIs (20), and two phase 3 trials for the treatment of hospital-acquired pneumonia have finished patient enrollment.Like vancomycin and teicoplanin, telavancin inhibits the polymerization of cell wall peptidoglycan precursors by binding to their D-alanyl-D-alanine termini, but telavancin has greater activity than vancomycin in this interaction (50% inhibitory concentration, 0.14 M versus 2.0 M) (8). Additionally, the interaction of telavancin with peptidoglycan precursors facilitates the perturbation of bacterial plasma membrane function, which leads to concentration-dependent membrane depolarization and increases in membrane permeability (8). The second mode of action is likely responsible for the more rapid and extensive bactericidal activity of telavancin than vancomycin and teicoplanin.Telavancin exhibits potent in vitro antibacterial activity ...