[Trends in Staphylococcus aureus antimicrobials susceptibilities: is methicillin still a relevant multiresistance marker?].
OBJECTIVE
Recent change was noted in S. aureus epidemiology, especially for none multiresistant methicillinresistant S. aureus (MRSA) and for multiresistant methicillin-susceptible S. aureus (MSSA). So, a six-year retrospective study was conducted to follow trends in antimicrobials resistance and to determine if methicillin remained a relevant multiresistant marker.


METHODS
All S. aureus isolates (duplicates excluded) isolated between 2001 and 2006 in a French 800-beds-teaching-hospital were included in the study.


RESULTS
Four thousand four hundred and fifty-five isolates providing from 3602 patients were identified between 2001 and 2006. MRSA rate and incidence for 1000 hospitalization-days significantly decreased from 34.7 to 22.6% and 1.3 to 0.6% respectively (p < 0.001). Significant decrease was observed for multiresistant MRSA (72.9 to 46.3%, p < 0.001), while no change was observed for multiresistant MSSA (2.9 to 3.4%). Among the 186 different antibiotic patterns isolated, four MRSA-phenotypes significantly decreased whereas two MSSA-phenotypes significantly increased. The main MRSA phenotype, resistant to kanamycin, tobramycin, macrolides-lincosamides-streptograminesB, and fluoroquinolones, significantly decreased from 11.9 to 5.9% (p < 0.001). Glycopeptide Intermediate S. aureus (GISA) phenotypes disappeared.


CONCLUSIONS
At this date, methicillin remains in our institution a relevant marker of multiresistance but trend is changing.
Grohs
P
P
Service de microbiologie, hôpital européen Georges-Pompidou, AP-HP, 20-40, rue Leblanc, 75908 Paris cedex 15, France. patrick_grohs@yahoo.com
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology; D024901:Drug Resistance, Multiple, Bacterial; D006785:Hospitals, University / Q000706:statistics & numerical data; D006801:Humans; D016106:Methicillin Resistance; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D010297:Paris / Q000453:epidemiology; D012189:Retrospective Studies; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification
D000900:Anti-Bacterial Agents