Vol.70 No.3 May 2022

Evaluation of a PCR assay for rapid identification of patients with Staphylococcus aureus bacteremia

Mikiyasu Sakai¹⁾, Daisuke Suzuki¹⁾, Atsushi Kawabata²⁾, Toshitaka Watariguchi³⁾, Hiroko Komai⁴⁾, Yuki Nagata⁵⁾ and Yoshio Miyake¹⁾

¹⁾Department of Pharmacy, Toyota Kosei Hospital, 500-1 Ibobara, Josui, Toyota, Aichi, Japan
²⁾Department of Infectious Disease, Toyota Kosei Hospital
³⁾Department of General Internal Medicine, Toyota Kosei Hospital
⁴⁾Department of Infection Control, Toyota Kosei Hospital
⁵⁾Department of Clinical Laboratory, Toyota Kosei Hospital

Abstract

Rapid drug susceptibility testing in cases of Staphylococcus aureus bacteremia (SAB) will enable early and appropriate antimicrobial selection. Toyota Kosei Hospital introduced a rapid polymerase chain reaction (rPCR) assay to detect methicillin-resistant S. aureus (MRSA) on May 20, 2019. In the present single-center retrospective study, SAB cases were divided into 2 groups: the pre-PCR group (April 1, 2018, to May 19, 2019) and post-PCR group (May 20, 2019, to August 31, 2020). The primary outcomes were the rate of use of anti-MRSA agents in patients with methicillin-susceptible S. aureus (MSSA) bacteremia and the time to start of appropriate anti-MRSA agents from blood culture collection in patients with MRSA bacteremia. The secondary outcomes were 28-day mortality, cost of intravenous antibiotic therapy for empiric therapy, and length of hospital stay.
Overall, 62 cases in the pre-PCR group and 62 cases in the post-PCR group were eligible for the analysis. For the MSSA bacteremia cases, the rate of use of anti-MRSA agents was significantly lower in the post-PCR group (52.3% vs. 26.7%, p=0.017), and for the MRSA bacteremia cases, the time to start of appropriate anti-MRSA agents from blood culture collection was significantly shorter in the post-PCR group (47.6 hours vs. 26.1 hours, p=0.042). There was no significant difference in the 28-day mortality (16.1% vs. 21.0%, p=0.645), cost of intravenous antibiotic therapy for empiric therapy (3,128 yen vs. 2,910 yen, p=0.816), or length of hospital stay (33.5 days vs. 25.5 days, p=0.184) between the 2 groups.
The introduction of rPCR for SAB has led to a reduction in the use of anti-MRSA agents for MSSA bacteremia and to early start of use of appropriate prescribe anti-MRSA agents for MRSA bacteremia.

Key word

Staphylococcus aureus, bacteremia, mecA, PCR, rapid detection

Received

August 30, 2021

Accepted

February 14, 2022

Jpn. J. Chemother. 70 (3): 326-333, 2022