We investigated the antibiotic susceptibility of glycopeptide-resistant enterococci (GRE). Seventy consecutive GRE were tested. Sixty-two isolates were identified as Enterococcus faecium (88.6%), and 8 (11.4%) as Enterococcus faecalis. All strains were susceptible to linezolid and daptomycin, while 17.1% (12/70) and 11.4% (8/70) were resistant to quinupristin/dalfopristin (QD) and tigecycline, respectively. All E. faecalis isolates were resistant to QD, while 4 of 62 (6.5%) E. faecium isolates were resistant to QD. All E. faecalis isolates were susceptible to tigecycline, while 14.5% (9/62) E. faecium isolates were resistant. Continued surveillance of GRE antibiotic susceptibilities is important for combating these multi-resistant nosocomial pathogens.
Daptomycin* ; Enterococcus faecalis ; Enterococcus faecium ; Linezolid ; Teicoplanin

Anti-Bacterial Agents ; Daptomycin ; Gram-Positive Bacterial Infections ; Hematologic Diseases ; Humans

BACKGROUND: Daptomycin is a novel cyclic lipopeptide antibiotic that exhibits in vitro bactericidal activity against gram-positive pathogens including methicillin-resistant staphylococci and vancomycin-resistant enterococci. The aim of this study is to determine the in vitro activities of daptomycin against recent clinical isolates of methicillin-resistant staphylococci and vancomycin-resistant enterococci in Korea. MATERIALS AND METHODS: A total of 117 clinical strains of methicillin-resistant staphylococci and vancomycin-resistant enterococci were isolated at a tertiary-care hospital in Korea in 2004. Susceptibility to daptomycin was tested by the CLSI broth microdilution method using Mueller-Hinton broth (MHB) which was adjusted to contain a final concentration of 50 microgram/mL of ionized calcium (Ca2+). Susceptibilities to ampicillin, oxacillin, levofloxacin, vancomycin, and linezolid were tested by the CLSI agar dilution method. RESULTS: All isolates of methicillin-resistant S. aureus and coagulase-negative staphylococci were inhibited by 1 microgram/mL of daptomycin, and MIC90s were 1 microgram/mL, which were similar to those of vancomycin and linezolid. MIC90s of daptomycin for vancomycin-resistant E. faecalis and E. faecium were 0.5 microgram/mL and 2 microgram/mL, respectively, and all isolates were susceptible to daptomycin. MIC90s of linezolid and levofloxacin for vancomycin-resistant enterococci were 1-2 microgram/mL and 64 microgram/mL, respectively. Resistance rates of vancomycin-resistant E. faecalis and E. faecium to levofloxacin were 100% and 96%, respectively. Daptomycin MICs in MHB supplemented to 20-25 microgram/ml of Ca2+ were 2-8 fold higher than those in MHB supplemented to 50 microgram/mL of Ca2+. CONCLUSION: Daptomycin is very active in vitro against methicillin-resistant staphylococci and vancomycin-resistant enterococci isolated in Korea, and it is important to test in vitro activity of daptomycin using MHB containing 50 microgram/mL of Ca2+.
Agar ; Ampicillin ; Calcium ; Daptomycin* ; Korea* ; Levofloxacin ; Linezolid ; Methicillin Resistance* ; Methicillin-Resistant Staphylococcus aureus ; Oxacillin ; Vancomycin

BACKGROUND: Daptomycin is a novel cyclic lipopeptide antibiotic that exhibits in vitro bactericidal activity against gram-positive pathogens including methicillin-resistant staphylococci and vancomycin-resistant enterococci. The aim of this study is to determine the in vitro activities of daptomycin against recent clinical isolates of methicillin-resistant staphylococci and vancomycin-resistant enterococci in Korea. MATERIALS AND METHODS: A total of 117 clinical strains of methicillin-resistant staphylococci and vancomycin-resistant enterococci were isolated at a tertiary-care hospital in Korea in 2004. Susceptibility to daptomycin was tested by the CLSI broth microdilution method using Mueller-Hinton broth (MHB) which was adjusted to contain a final concentration of 50 microgram/mL of ionized calcium (Ca2+). Susceptibilities to ampicillin, oxacillin, levofloxacin, vancomycin, and linezolid were tested by the CLSI agar dilution method. RESULTS: All isolates of methicillin-resistant S. aureus and coagulase-negative staphylococci were inhibited by 1 microgram/mL of daptomycin, and MIC90s were 1 microgram/mL, which were similar to those of vancomycin and linezolid. MIC90s of daptomycin for vancomycin-resistant E. faecalis and E. faecium were 0.5 microgram/mL and 2 microgram/mL, respectively, and all isolates were susceptible to daptomycin. MIC90s of linezolid and levofloxacin for vancomycin-resistant enterococci were 1-2 microgram/mL and 64 microgram/mL, respectively. Resistance rates of vancomycin-resistant E. faecalis and E. faecium to levofloxacin were 100% and 96%, respectively. Daptomycin MICs in MHB supplemented to 20-25 microgram/ml of Ca2+ were 2-8 fold higher than those in MHB supplemented to 50 microgram/mL of Ca2+. CONCLUSION: Daptomycin is very active in vitro against methicillin-resistant staphylococci and vancomycin-resistant enterococci isolated in Korea, and it is important to test in vitro activity of daptomycin using MHB containing 50 microgram/mL of Ca2+.
Agar ; Ampicillin ; Calcium ; Daptomycin* ; Korea* ; Levofloxacin ; Linezolid ; Methicillin Resistance* ; Methicillin-Resistant Staphylococcus aureus ; Oxacillin ; Vancomycin

Daptomycin, a lipopeptide antibiotic with similar action as vancomycin, is used to treat complicated skin and soft tissue infections caused by resistant Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus, penicillin-resistant streptococci, and vancomycin-resistant enterococci. Acute generalized exanthematous pustulosis (AGEP), characterized by acute onset of numerous sterile, nonfollicular pinhead sized pustules, is common secondary to drugs, in particular, antibiotics. We present the first case of AGEP following the use of daptomycin.
Acute Generalized Exanthematous Pustulosis ; Anti-Bacterial Agents ; Daptomycin ; Gram-Positive Bacteria ; Methicillin-Resistant Staphylococcus aureus ; Skin ; Soft Tissue Infections ; Vancomycin

Recently, infections caused by antibiotic-resistant bacteria continue to climb in the community and the hospital around the world. Our current antimicrobial agents are gradually becoming ineffective and a new pipeline of powerful compounds is needed urgently. A number of new antimicrobial compounds are in development, including novel glycopeptides (dalbavancin, telavancin, and oritavancin), daptomycin, tigecycline, ceftobiprole, iclaprim, and doripenem. The article will provide an update on the newly marketed and potentially effective antibacterial agents in the late-stage development pipeline
Aminoglycosides ; Anti-Bacterial Agents ; Anti-Infective Agents ; Bacteria ; Carbapenems ; Cephalosporins ; Daptomycin ; Drug Resistance ; Drugs, Investigational ; Glycopeptides ; Minocycline ; Pyrimidines ; Trastuzumab

In the face of escalating problems with pathogen control, the development of proper formulations of existing antibiotics is as important as the development of novel antibiotics. Daptomycin is a lipopeptide antibiotic with potent activity against Gram-positive bacteria. Currently, only injectable solution of daptomycin has been approved for clinical use. In the present study, the formulation of PEGylated liposomal daptomycin (PLD) was prepared and optimized, and its efficacy against methicillin-resistant Staphylococcus aureus (MRSA252) strains was investigated. The obtained PLD had a mean vesicle diameter of (111.5 +/- 15.4) nm and a mean percent drug loading of (5.81 +/- 0.19) % with high storage stability. Potent activity of PLD against MRSA was demonstrated in vitro with a more sustained effect than that of conventional liposomal daptomycin and daptomycin solution. In addition, intravenous administration of a single dose (equal to human use) of PLD significantly increased the survival of mice in a MRSA252 systemic infection model compared with other formulations. Drug distribution in the lung was significantly enhanced following administration of PLD, and no measurable tissue lesions or pathological changes were detected during PLD treatment. Taken together, PEGylated liposomes loaded with daptomycin may represent a promising approach to reduce MRSA252 infections, especially those involving bloodstream dissemination, such as hematogenous pulmonary infection.
Animals ; Anti-Bacterial Agents ; pharmacology ; Daptomycin ; pharmacology ; Liposomes ; Methicillin-Resistant Staphylococcus aureus ; drug effects ; Mice ; Staphylococcal Infections ; drug therapy

Methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of healthcare-associated infections. Recently, community-associated MRSA has emerged, manifesting as skin and soft tissue infections in patients without any prior healthcare contact. Vancomycin, a glycopeptide in clinical use for more than 50 years, still remains an acceptable treatment option. However, significant concerns have been raised regarding the decreasing susceptibility of S. aureus to this agent. The growing awareness of the limitations of vancomycin has served as an impetus for development of newer agents. There has been an increase in the number of agents available to treat MRSA infections. Linezolid, daptomycin, telavancin, and ceftaroline have received regulatory approval in the last decade for the treatment of MRSA. Although these drugs do have certain differentiating attributes and may offer some advantages over vancomycin, they also have significant limitations.
Daptomycin ; Delivery of Health Care ; Humans ; Linezolid ; Methicillin Resistance ; Methicillin-Resistant Staphylococcus aureus ; Skin ; Soft Tissue Infections ; Vancomycin

There are relatively few novel antimicrobial agents despite the dramatic increase in antimicrobial resistance and multiple drug resistance of clinical isolates worldwide. Vancomycin is still the most widely used antibiotic for treating resistant Gram-positive coccal infections in children, especially for methicillin-resistant Staphylococcus aureus. For children with Gram-positive coccal infections where vancomycin is not effective or older therapeutic agents cannot be tolerated, linezolid, quinupristin-dalfopristin or daptomycin may be useful in the appropriate clinical setting. For Gram-negative infections, new carbapenems await clinical application. Tebipenem pivoxil is a novel oral carbapenem undergoing clinical trials for acute otitis media in pediatric patients. Antiviral drug development is now progressing at the pace of antibiotic development 30 years ago. Newer antiviral agents used for the treatment of herpes viruses and hepatitis C virus infections in children are included in this review.
Acetamides ; Anti-Bacterial Agents ; Anti-Infective Agents ; Antiviral Agents ; Carbapenems ; Child ; Daptomycin ; Drug Resistance, Multiple ; Hepacivirus ; Humans ; Methicillin-Resistant Staphylococcus aureus ; Otitis Media ; Oxazolidinones ; Vancomycin ; Virginiamycin ; Linezolid

Methicillin-resistant Staphylococcus aureus (MRSA), a leading cause of nosocomial infections, has been increasingly recognized in communities of the United States. This article will review the clinical spectrum and treatment of MRSA infections in children in the context of recent epidemiological changes of MRSA infections. In general, community-associated (CA) MRSA most frequently causes skin and soft tissue infections and has an increased association with invasive infections, particularly pneumonia and musculoskeletal infections. Hospital-associated (HA) MRSA strains tend to be associated with bloodstream infections, pneumonia, and surgical site infections. Different from the United States, CA-MRSA infections are not common in Korea (only 5.9%); however, there are some CA-MRSA clones that are different from HA- MRSA clones in Korea and from CA-MRSA clones in other countries. The treatment of MRSA infections should be guided by antimicrobial susceptibility testing, the site of infection, and the infection severity. Vancomycin is the treatment of choice for invasive MRSA infections. Other agents such as trimethoprim- sulfamethoxazole, clindamycin, linezolid, quinupristin-dalfopristin, and daptomycin have been used for some conditions.
Acetamides ; Child ; Clindamycin ; Clone Cells ; Cross Infection ; Daptomycin ; Humans ; Korea ; Methicillin Resistance ; Methicillin-Resistant Staphylococcus aureus ; Oxazolidinones ; Pneumonia ; Skin ; Soft Tissue Infections ; Staphylococcus aureus ; Sulfamethoxazole ; United States ; Vancomycin ; Virginiamycin ; Linezolid