Clinical and microbiological characteristics of rifampicin-resistant MRSA bacteraemia. (20th December 2022)

• Record Type: Journal Article
• Authors: Bae, Seongman; Kim, Eun Sil; Lee, Yun Woo; Jung, Jiwon; Kim, Min Jae; Chong, Yong Pil; Kim, Sung-Han; Choi, Sang-Ho; Lee, Sang-Oh; Kim, Yang Soo
• Is Part Of: Journal of antimicrobial chemotherapy. Volume 78:Number 2(2023)
• Page Start: 531
• Page End: 539
• Publication Date: 2022-12-20
• Subjects: Anti-infective agents -- Periodicals; Chemotherapy -- Periodicals; 615.58
• DOI: 10.1093/jac/dkac428
• Languages: English
• ISSNs: 0305-7453

Abstract

Abstract: Objectives: The clinical significance of rifampicin resistance in Staphylococcus aureus infections has not been demonstrated. Here, we evaluated the clinical characteristics of rifampicin-resistant S. aureus infection. Methods: Data were collected from adult patients who were hospitalized with MRSA bacteraemia between March 2007 and May 2020 at a tertiary hospital in South Korea. The clinical characteristics and treatment outcomes of patients infected with rifampicin-resistant MRSA were compared with those of rifampicin-susceptible isolates. All-cause death and recurrence of MRSA infection were assessed for 90 days. Results: Of the 961 patients with MRSA bacteraemia, 61 (6.3%) were infected by rifampicin-resistant isolates. The type of infection focus and duration of bacteraemia did not significantly differ between the two groups. Rifampicin-resistant MRSA isolates were more likely to have multidrug resistance and a higher vancomycin MIC relative to the rifampicin-susceptible isolates. The 90-day recurrence rate was higher in the patients infected with rifampicin-resistant MRSA compared with those with rifampicin-susceptible MRSA (18.0% versus 6.2%, P < 0.001), whereas the 90-day mortality was comparable between the two groups (27.9% versus 29.2%, P = 0.94). After adjusting for potential confounding factors, rifampicin resistance was significantly associated with 90-day recurrence (subdistributional HR: 2.31; 95% CI: 1.05–5.10; P = 0.04). Conclusions: Rifampicin-resistant MRSA isolates showed distinct microbiological features in terms of multidrug resistance and a high vancomycin MIC. Although the management of MRSA bacteraemia was not significantly different between the two groups, recurrence was significantly more common in the rifampicin-resistant group. Rifampicin resistance may play a significant role in infection recurrence.