AB0398 Investigation of preoperative intranasal colonisation in orthopaedic surgery for patient with rheumatoid arthritis

Objectives Coagulase-negative staphylococci (CoNS) is listed as the major SSI causative organism in the field of orthopaedic surgery, but detailed report on the presence or absence of methicillin-resistant CoNS of intranasal colonisation is not found. Methods In 13 months from July 2016 to the end of July 2017, 1000 cases of consecutive cases in which nasal cavity culture was performed within one month prior to hospitalisation for patients scheduled for our orthopaedic surgery. 223 men, 777 women, average age 66.4 years old, 197 cases of RA patients, 803 cases except RA patients. The method of intranasal culture is as follows. After culturing for 18 hours at 35 ° C using blood agar medium (daily water) and CHROMager MRSA selective medium (Kanto Kagaku), identification of bacterial species of the genus Staphylococcus grown and cultivation of drug susceptibility tests It was carried out by BD Phoenix according to the method of the Association (CLSI). Results The results of intranasal culture showed that S. aureus, S. epidermidis, CoNS (excluding S. Epidermidis) and culture negative were 18.2%, 27.8%, 7.8%, and 23.9%, respectively. MRSA, MRSE and MRCoNS (excluding MRSE) with methicillin resistance were 3.2%, 22.1% and 1.7%, respectively, and 27.0% of methicillin resistant bacteria were found to exist. Especially in patients with RA, the methicillin-resistant bacterial colonisation rate was significantly higher (p Conclusions Methicillin-resistant Staphylococcus was found to be 27.0% intranasal colonisation of patients in orthopaedic surgery. Especially in RA patient, it was high rate of 38.6%. In the future, we need to consider the selection of perioperative preventive antibacterial drugs. Disclosure of Interest None declared