agr Dysfunction Affects Staphylococcal Cassette Chromosome mec Type-Dependent Clinical Outcomes in Methicillin-Resistant Staphylococcus aureus Bacteremia

作者：Kang Chang Kyung; Cho Jeong Eun; Choi Yoon Jeong; Jung Younghee; Kim Nak Hyun; Kim Chung Jong; Kim Taek Soo; Song Kyoung Ho; Choe Pyoeng Gyun; Park Wan Beom; Bang Ji Hwan; Kim Eu Suk; Park Kyoung Un; Park Sang Won; Kim Nam Joong; Oh Myoung don; Kim Hong Bin^*

来源：Antimicrobial Agents and Chemotherapy, 2015, 59(6): 3125-3132.

DOI：10.1128/AAC.04962-14

Staphylococcal cassette chromosome mec element (SCCmec) type-dependent clinical outcomes may vary due to geographical variation in the presence of virulence determinants. We compared the microbiological factors and mortality attributed to methicillin-resistant Staphylococcus aureus (MRSA) bacteremia between SCCmec types II/III and type IV. All episodes of MRSA bacteremia in a tertiary-care hospital (South Korea) over a 4.5-year period were reviewed. We studied the microbiological factors associated with all blood MRSA isolates, including spa type, agr type, agr dysfunction, and the genes for Panton-Valentine leukocidin (PVL) and phenol-soluble modulin (PSM)-mec, in addition to SCCmec type. Of 195 cases, 137 involved SCCmec types II/III, and 58 involved type IV. The mortality attributed to MRSA bacteremia was less frequent among the SCCmec type IV (5/58) than that among types II/III (39/137, P = 0.002). This difference remained significant when adjusted for clinical factors (adjusted odds ratio [aOR], 0.14; 95% confidence interval [CI], 0.04 to 0.49; P = 0.002). Of the microbiological factors tested, agr dysfunction was the only significant factor that showed different positivity between the SCCmec types, and it was independently associated with MRSA bacteremia-attributed mortality (aOR, 4.71; 95% CI, 1.72 to 12.92; P = 0.003). SCCmec type IV is associated with lower MRSA bacteremia-attributed mortality than are types II/III, which might be explained by the high rate of agr dysfunction in SCCmec types II/III in South Korea.

• 出版日期2015-6