Journal des maladies infectieuses et de la thérapie

Abstrait

Longitudinal Changes in Clinical Epidemiology and Drug Sensitivity of Community-associated Methicillin-Resistant Staphylococcus Aureus in a Tertiary Hospital in Japan

Jun Taniguchi, Masao Yoshinaga, Yu Kucho, Mayuko Watanabe and Chiharu Kushida

Aim: The present study aimed to determine longitudinal changes in the background of patients with community acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) and those in the susceptibility of CA-MRSA to antibiotics in a tertiary center.
Methods: The characteristics of MRSA isolates and patients between October 2005 and December 2011 were determined. This period was divided into two: the first half was from October 2005 to December 2008 and the second half was from January 2009 to December 2011. Data of age and sex of patients, and date and site of isolation were obtained. Antimicrobial susceptibility was examined for each period. Multiplex polymerase chain reaction methods were used to determine Staphylococcal cassette chromosome mec types and MRSA typing.
Results: A total of 513 MRSA isolates were identified. Of 265 and 248 MRSA strains in the first and second halves of the study period, 51 (19%) and 50 (20%) strains, respectively, were CA-MRSA. The prevalence of CAMRSA was highest in patients aged in the 80s and CA-MRSA was mainly isolated from the nose/pharynx. Antimicrobial resistance increased from the 2005-2008 to 2009-2011 periods for erythromycin (p=0.03), levofloxacin (p=0.003), imipenem (p=0.01), fosfomycin (p=0.02), and minocycline (p<0.001), but not for gentamicin, clindamycin, rifampicin, and vancomycin.
Conclusions: CA-MRSA accounts for 20% of total MRSA isolates in Japan. Ages of subjects with CA-MRSA and isolation sites have changed from the emerging stage to recent years. Antibiotic resistance has significantly increased in a tertiary hospital in Japan.