Περίληψη:
Objectives: Dependence on linezolid was recently described as significant growth acceleration of linezolidresistant Staphylococcus epidermidis (LRSE) isolates upon linezolid exposure. We investigated the possible contribution of linezolid dependence to LRSE dissemination in Greece. Methods: Linezolid resistance rates were estimated in six tertiary hospitals located throughout Greece between 2011 and 2013. Sixty-three randomly selected LRSE recovered in these hospitals during this period were studied. Growth curve analysis was conducted with and without linezolid. Clonality of the isolates was investigated by PFGE and MLST. Results: During the study period, the LRSE rate in the participating hospitals rose significantly from 6.9% to 9% (P=0.006); the increase was more prominent in ICUs (from 15.1% to 20.9%; P=0.005). Forty-seven (74.6%) of the 63 LRSE, derived from all study hospitals, clearly exhibited linezolid dependence, growing significantly faster in the presence of 16 and 32 mg/L linezolid. Of note, 61 (96.8%) LRSE exhibited a single macrorestriction pattern and belonged to ST22, which included all linezolid-dependent LRSE. The remaining two LRSE belonged to unique STs. Five of six linezolid-dependent isolates tested also exhibited linezolid dependence upon exposure to 8 mg/L linezolid. Interestingly, five of six ST22 linezolid-non-dependent isolates tested developed linezolid dependence when linezolid exposure preceded growth analysis. Conclusions: The rapid LRSE dissemination in Greek hospitals threatens linezolid activity. The observation that most LRSE belonged to ST22 and expressed dependence on linezolid clearly implies that the spread of linezolid resistance should have been driven by this trait, which provided the LRSE with a selective advantage under linezolid pressure. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved.
Συγγραφείς:
Karavasilis, V.
Zarkotou, O.
Panopoulou, M.
Kachrimanidou, M.
Themeli-Digalaki, K.
Stylianakis, A.
Gennimata, V.
Ntokou, E.
Stathopoulos, C.
Tsakris, A.
Pournaras, S.
Kouskouni, E.
Vrioni, G.
Mamali, V.
Kousouli, E.
Papagiannakopoulou, P.
Kristo, I.
Dafopoulou, K.
Hadjichristodoulou, C.
Carle, P.
Kimouli, M.
Perivolioti, E.
Nepka, M.
Foudoulis, K.
Stathoulopoulou, F.
Papanikolaou, P.
Poulou, A.
Tsorlini, E.
Greek Study Group on Staphylococcal Linezolid Resistance
Λέξεις-κλειδιά:
linezolid; antiinfective agent; linezolid, antibiotic resistance; antibiotic sensitivity; Article; bacterial growth; bacterial virulence; bacterium isolate; bacterium isolation; broth dilution; clonal variation; controlled study; epsilometer test; Greece; growth acceleration; growth curve; human; infection rate; linezolid resistant Staphylococcus epidermis; minimum inhibitory concentration; molecular typing; nonhuman; Staphylococcus epidermidis; tertiary care center; classification; drug effects; genetics; genotype; growth, development and aging; metabolism; microbiology; multilocus sequence typing; pulsed field gel electrophoresis; Staphylococcal Infections; Staphylococcus epidermidis, Anti-Bacterial Agents; Drug Resistance, Bacterial; Electrophoresis, Gel, Pulsed-Field; Genotype; Greece; Humans; Linezolid; Multilocus Sequence Typing; Staphylococcal Infections; Staphylococcus epidermidis; Tertiary Care Centers
