No abstract available.
Humans ; Teicoplanin*

No abstract available.
Diffusion* ; Teicoplanin*

No abstract available.
Drug Monitoring* ; Teicoplanin*

No abstract available.
Gram-Positive Bacterial Infections* ; Teicoplanin*

No abstract available.
Gram-Positive Bacterial Infections* ; Teicoplanin*

BACKGROUNDS: The emergence of resistant strains to glycopeptide in enterococci(GRE) is increasingly serious problem in the worldwide. Automated methods and disk diffusion test have difficulties in detecting vancomycin resistance of some strains of vancomycin-resistant enterococci(VRE), especially having vanC genotypes. And a few studies have been done assessing the ability of antimicrobial susceptibility testing methods to detect teicoplanin resistance in enterococci. METHODS: We evaluated the abilities of two commercial kits including Vitek GPS-IZ(BioMerieux, Vitek, Inc., USA) and E-test(AB Biodisk, USA), and disk diffusion test to detect glycopeptide resistance using 34 strains of vanA and 15 strains of vanC1/C2 VRE. We compared the results with those of standard agar dilution test. RESULTS: In detecting vancomycin resistance, no very major or major errors were seen, and minor error rates were observed with disk diffusion(25%), Vitek GPS-IZ(20%) and E-test(8%). Overall sensitivities of all three methods in detecting vancomycin resistance of vanA VRE were 97-100%, but sensitivities in detecting vancomycin resistance of vanC VRE were 20% in disk diffusion, 87% in E-test and 87% in Vitek GPS-IZ. In detecting teicoplanin resistance, very major error rate was high in Vitek GPS-IZ(47%), but no very major or major errors were seen in disk diffusion and E-test; minor error rates of 2% and 6% were seen in Vitek GPS-IZ and E-test, respectively. CONCLUSION: All three methods detect vancomycin resistance of vanA VRE, but they continue to demonstrate problems in detecting low-level vancomycin resistance and the Vitek GPS-IZ is difficult to detect teicoplanin resistance in enterococci.
Agar* ; Diffusion* ; Genotype ; Teicoplanin ; Vancomycin Resistance

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

BACKGROUND: We tried to evaluate the incidence and clinical significance of coagulase-negative staphylococci (CoNS) with reduced susceptibilities to glycopeptides. In addition, the ability of disk diffusion and Vitek system to detect CoNS with reduced susceptibilities to glycopeptides were compared with the standard agar dilution method. METHODS: One hundred and nineteen clinical isolates of CoNS were recovered at Samsung Medical Center from June to July 1998 and were examined for their susceptibilities to vancomycin and teicoplanin by disk diffusion method (30-microgram disk), Vitek system with GPS-AA card, and agar dilution for the determination of MICs. The records of all patients, from whom CoNS with decreased susceptibility to glycopeptide was isolated, were reviewed. RESULTS: All CoNS showed uniform susceptibility to vancomycin by all three methods but 11 strains (9.2%) exhibited reduced susceptibilities to teicoplanin (MICs, 16 to 32 microgram/mL). All but suspected colonized strains were nosocomially acquired and were isolated from 7 different wards. None were previously treated with teicoplanin. The concordance rates of disk diffusion method and Vitek system with agar dilution method were 94.1% and 84%, respectively. However, the sensitivity of disk diffusion method and Vitek system were only 50.0% and 62.5%, respectively. CONCLUSIONS: This study demonstrates that CoNS with reduced susceptibilities to glycopeptides is not uncommon and may cause true infections in clinical settings. However, neither disk diffusion method nor Vitek system could differentiate these strains from more susceptible isolates.
Agar ; Colon ; Diffusion ; Glycopeptides* ; Humans ; Incidence* ; Teicoplanin ; Vancomycin

BACKGROUND: Teicoplanin is a glycopeptide antimicrobial agent effective against methicillin-resistant staphylococci. Decreased susceptibility of staphylococci to glycopeptides has been increasing. Teicoplanin diffuses poorly in agar and therefore the correlation between the inhibition zone diameter and the minimal inhibitory concentration(MIC) is rather poor. The purpose of this study was to evaluate the prevalence of teicoplanin-resistant staphylococci and to assess the reliability of inhibition zone diameters for determining the susceptibility of staphylococci to teicoplanin by comparing the results of the agar dilution MICs. METHODS: From June to August 1997, 290 clinical isolates of staphylococci(77 coagulase negative staphylococci(CNS), 213 Staphylococcus aureus) were collected. The antimicrobial susceptibilities to teicoplanin were determined by inhibition zone diameter and the results were compared with the MICs determined by the agar dilution method. RESULTS: Among 77 CNS strains, 75(97.4%) were susceptible and 2(2.6%) were intermediate by agar dilution method and all 213 strains of S. aureus were susceptible to teicoplanin. There was a poor correlation(r=0.50) between the zone diameters of inhibition and agar dilution MICs. In comparison with the results of disk diffusion test and agar dilution MIC, eight (2.8%) out of 290 isolates showed discrepancies (major error rates : 0.3%, minor error rates: 2.4%). CONCLUSIONS: Two(2.6%) out of 77 strains of CNS and none of 213 S. aureus strains revealed decreased susceptibility to teicoplanin. And the inhibition zone diameter was less reliable in determining the susceptibility of staphylococci than MICs. Therefore, the more effective and convenient method is needed.
Agar ; Coagulase ; Diffusion* ; Glycopeptides ; Methicillin Resistance ; Prevalence* ; Staphylococcus ; Teicoplanin*

BACKGROUND: The purpose of this study was to investigate the prevalence of Stap hylococcus aureus with decreased susceptibility to glycopeptides in Korea and to evaluate the methods for detection. METHODS: From March to May 1998, 106 clinical isolates of S. aureus were collected from patients of the Kosin Medical Center . Antimicrobial susceptibilities for vancomycin and teicoplanin were determined by NCCLS disc diffusion method and the MICs were determined by agar dilution method. Correlation between both results was evaluated. RESULTS: MICs of vancomycin and teicoplanin against S. aureus isolates were 0.5 ~2 microgram/mL and 0.25 ~8 microgram/mL. Some S. aureus isolates showed decreased susceptibility to teicoplanin (MIC 4 microgram/mL, 33 strains; MIC 8 microgram/mL, 1 strain), but none showed decreased susceptibility to vancomycin. A positive correlation was observed between the inhibitory zone diameters of teicoplanin disc and the MICs of teicoplanin(P< 0.0 1). Inhibitory zone diameter differences between vancomycin and teicoplanin discs also showed a positive correlation with the MICs of teicoplanin (P< 0.01). Strains whose inhibitory zone diameters of teicoplanin disc were less than 16 mm, the sensitivity and positive predictive value for the detection of strains with MICs more than 4 microgram/mL were 100 % (34/ 34) and 43% (34/ 79), respectively. In strains with inhibitory zone diameter difference of more than 4 mm, the sensitivity and positive predictive value of detection in MICs of more than 4 microgram/mL were 94 % (32/ 34) and 70 % (32/46), respectively. CONCLUSION: Although S. aureus with intermediate or full resistance to glycopeptides was not isolated in this study, few strains had decreased susceptibility to teicoplanin. We conclude that when the inhibitory zone diameters of teicoplanin disc are less than 16 mm or inhibitory zone diameter difference between vancomycin and teicoplanin discs is more than 4 mm, the presence of S. aureus isolates with decreased susceptibility to teicoplanin should be suspected.
Agar ; Diffusion ; Glycopeptides ; Humans ; Korea ; Prevalence ; Staphylococcus aureus* ; Staphylococcus* ; Teicoplanin* ; Vancomycin