1082. Impact of Vancomycin Minimum Inhibitory Concentration on Clinical Outcome of Methicillin-Susceptible Staphylococcus aureus Bacteremia
Session: Poster Abstract Session: Clinical Infectious Diseases: Bacteremia and Endocarditis
Friday, October 28, 2016
Room: Poster Hall
Background:

Recent data suggest that vancomycin minimum inhibitory concentration (MIC) is related with the outcome of not only methicillin-resistant Staphylococcus aureus (MRSA) bacteremia but methicillin-sensitive S. aureus (MSSA) bacteremia. We aimed to evaluate the effect of vancomycin MIC on clinical outcome of MSSA bacteremia.

Methods:

We analyzed a prospectively collected cohort of patients with MSSA bacteremia at a 2700 bed tertiary-care hospital in South Korea from August 2008 to March 2010. Patients with vancomycin MIC ≥ 1.5 ㎍/㎖ by E-test is classified as high vancomycin MIC group. We compared the clinical features and outcomes of high vancomycin MIC group with those of low vancomycin MIC group.

Results:

A total of 149 episodes of MSSA bacteremia was analyzed. Seventy-two (48%) patients was high vancomycin MIC group. Accessory gene regulator (Agr) type II and III is more frequent in high vancomycin MIC group. High vancomycin MIC (OR 2.7, 95% CI 1.259-6.094, p=0.011) and age (OR 1.03; 95%CI 1.002-1.059, p=0.036) is independent risk factor for all-cause mortality at 12 weeks.

Conclusion:

Higher vancomycin MIC is related with mortality in patients with MSSA bacteremia. Further studies are needed to understand a relationship vancomycin MIC and agr system.

Total (n=149)

MIC < 1.5/

(n=77)

MIC ≥ 1.5/

(n=72)

P value

Mean age

57.2±14.9

57.7±15.7

56.6±14.2

0.67

Male gender, number (%)

99 (66.4)

53 (68.8)

46 (63.9)

0.52

Site of acquisition

Community

29 (19.5)

17 (22.1)

12 (16.7)

0.40

Healthcare

50 (33.6)

26 (33.8)

24 (33.3)

0.96

Hospital

70 (47)

34 (44.2)

36 (50)

0.48

agr subgroup

agr type I

83 (55.7)

42 (54.5)

41 (56.9)

0.768

agr type II

24 (16.1)

8 (10.4)

16 (22.2)

0.050

agr type III

34 (22.8)

23 (29.9)

11 (15.3)

0.034

agr type IV

3 (2)

2 (2.6)

1 (1.4)

>0.999

agr dysfunction

17 (11.4)

11 (14.3)

6 (8.3)

0.253

ST188

29/148 (19.6)

13/76 (17.1)

16/72 (22.2)

0.433

ST72

15/148 (10.1)

10/76 (13.2)

5/72 (6.9)

0.279

Clinical outcome

Persistant bacteremia

6 (4.1)

5 (6.5)

1 (1.4)

0.21

Recurrence within 12 weeks

3 (2)

0

3 (4.2)

0.11

Mortality at discharge

28 (18.8)

9 (11.7)

19 (26.4)

0.02

Mortality at day 7

5 (3.4)

1 (1.3)

4 (5.6)

0.15

Mortality at day 28

28 (18.8)

10 (13)

18 (25)

0.06

Mortality at week 12

38 (25.5)

13 (16.9)

25 (34.7)

0.01

Bacteremia-related mortality at discharge

17 (11.4)

6 (7.8)

11 (15.3)

0.15

Bacteremia-related mortality at week 12

21 (14.1)

6 (7.8)

15 (20.8)

0.02

Shi Nae Yu, MD1, Yong Pil Chong, MD2, Su-Jin Park, PhD3, Sung-Han Kim, MD2, Sang-Oh Lee, MD2, Sang-Ho Choi, MD2, Jun Hee Woo, MD2 and Yang Soo Kim, MD2, (1)Soonchunhyang University Cheonan Hospital, Cheonan, Korea, The Republic of, (2)Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea, The Republic of, (3)Center for Antimicrobial Resistance and Microbial Genetics, Asan Medical Center, Seoul, Korea, The Republic of

Disclosures:

S. N. Yu, None

Y. P. Chong, None

S. J. Park, None

S. H. Kim, None

S. O. Lee, None

S. H. Choi, None

J. H. Woo, None

Y. S. Kim, None

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