Clinical Characteristics of Invasive Methicillin-Resistant Staphylococcus aureus at General Hospital in the Central Region of Japan from July 2014 to June 2015

Methicillin-resistant Staphylococcus aureus is crucial pathogen caused severe invasive infection disease. This study was conducted to find out the prevalence and antimicrobial susceptibility pat- tern of invasive Methicillin-resistant Staphylococcus aureus isolates at general hospital in the cen- tral region of Japan from July 2014 to June 2015. Methicillin-resistant Staphylococcus aureus was identified by standard laboratory procedure. Antimicrobial susceptibility testing was performed by micro dilution assay according to CLSI recommendation. Invasive Methicillin-resistant Staphy- lococcus aureus disease was defined as isolation of bacteria from a normally sterile body site. One hundred seventy-one methicillin-resistant Staphylococcus aureus were isolated among which 95 (55.6%) were from inpatient and 76 (44.4%) were from outpatient. The age incidence of (0 - 1) years, (1 - 10) years, (11 - 40) years, (41 - 60) years and >60 years age groups were 18 (10.5%), 41 (24.0%), 15 (8.8%), 5 (2.9%), and 92 (53.8%) respectively. There was significant difference of age distribution between invasive and noninvasive disease in 0 - 1 years group and 11 - 40 years age group. Positive samples were received mostly from the pediatrics (56/32.7%), respiratory medi- cine (25/14.6%) and general medicine (25/14.6%). We also found the significant differences of department between invasive and noninvasive disease in pediatrics, dermatology, and surgery. Arbekacin, teicoplanin, and vancomycin were the most active antibiotics with 100% susceptible rates in our study. Our study revealed that erythromycin and gentamicin were more antimicrobial effective in invasive disease than in noninvasive disease significantly. Methicillin-resistant Sta- phylococcus aureus infection spreads worldwide easily and inadequate use of antibiotics contri- butes to uptake of their new antimicrobial resistance. Continuous antimicrobial surveys are need for guiding policy on the adequate use of antibiotics to reduce the morbidity and mortality. * Corresponding author.