Surveillance of linezolid resistance in Germany, 2001–2002

Abstract

A surveillance study was performed throughout Germany from November 2001 to June 2002 to assess the prevalence of linezolid-resistant isolates among Gram-positive bacteria from routine susceptibility data and to compare the in-vitro activity of linezolid to that of other antibacterial agents. Each of 86 laboratories provided routine susceptibility data for 100 consecutive isolates. Most laboratories (c. 60%) used the disk diffusion test. Laboratories were also requested to send a representative sample of their isolates, as well as all isolates reported as intermediate or resistant to linezolid, to a reference laboratory for MIC determination. Susceptibility data for 8594 isolates were evaluated. Sites of infection were skin and soft tissue (29.9%), upper and lower respiratory tract (19.1%), foreign body or catheter (10.5%), or urinary tract (9.8%). Routine linezolid susceptibility data were reported for 6433 isolates. The prevalence of linezolid resistance, as reported to the clinician, was 0.4% in Staphylococcus aureus, 0.3% in Staphylococcus epidermidis, 2.9% in Enterococcus faecalis, 2.3% in Enterococcus faecium, 1.4% in Streptococcus pyogenes and 2.9% in Streptococcus agalactiae. Linezolid resistance was not detected in Streptococcus pneumoniae or in viridans group streptococci. Sixty-nine of 115 isolates reported as intermediate or resistant to linezolid were retested, but none was resistant to linezolid. Linezolid exhibited excellent in-vitro activity against representative isolates of the six most frequently encountered species (MIC90, 1-2 mg/L). The prevalence of resistance to linezolid was very low in Germany. Organisms reported as linezolid-resistant should be retested, either in the same laboratory with an alternative method or in a reference laboratory.

Determination of Risk Factors Associated With Isolation of Linezolid-Resistant Strains of Vancomycin-Resistant Enterococcus

“…[17][18][19][20][21] Despite increased linezolid usage, international surveillance data still show a relatively low incidence of linezolid-resistant Enterococcus, with a prevalence rate of 2% or less, and reports of linezolid-resistant VRE are limited to case reports and institutional outbreaks. [1][2][3][4][5][6][11][12][20][21][22][23] However, in our hospital, microbiological data showed a much higher prevalence of linezolid resistance among Enterococcus isolates, at 9.8%, and in this study we found the prevalence of linezolid resistance among VRE isolates to be 20%. A potential explanation for this would be the much higher and continually increasing rate of linezolid usage at our institution, compared with the national average (17.4 vs 6.3 DDD per 1,000 patient-days).…”

“…Linezolid resistance in VRE, although relatively uncommon, was initially associated with prolonged exposure to linezolid. [1][2][3][4][5][6] However, more recently, linezolid-resistant VRE has been isolated from patients who did not have prior antimicrobial exposure, which is more consistent with horizontal transmission of the organism. 5,[7][8][9][10][11][12] Furthermore, newer data document a much higher prevalence of linezolid-resistant organisms-11% to 17%-recovered from patients colonized or infected with VRE.…”

Emergence of Linezolid Resistance in a Methicillin Resistant Staphylococcus aureus Strain

“…Epidemiologic studies indicate that the overall prevalence of linezolid resistant clinical S. aureus isolates is low [15]. So far, most linezolid resistant S. aureus emerged during prolonged therapy with linezolid [7,10,11].…”

Alternative Strategies for Proof-of-Principle Studies of Antibacterial Agents

“…Furthermore, levofloxacin and vancomycin (82), vancomycin and cefpirome (84), vancomycin (85), and various fluoroquinolones (86) reduce viable counts of S. epidermidis and CoNS, respectively, less effectively than those of S. aureus. Likewise, oral streptococci are almost always less susceptible than or at least as susceptible as S. pneumoniae to the agents studied (74,(87)(88)(89)(90)(91).…”