Staphylococcus Aureus Bacteremia Due to Central Venous Catheter Infection: A Clinical Comparison of Infections Caused by Methicillin-Resistant and Methicillin-Susceptible Strains.

Kazuhiro Ishikawa,Keiichi Furukawa

doi:10.7759/cureus.16607

Abstract

Objectives: Staphylococcus aureus bacteremia has a mortality rate of 20-40% and is mainly caused by central venous catheter (CVC) infection. We aimed to investigate differences between patients with methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) bacteremia due to CVC infection.Methods: This retrospective study, of data collected between August 2004 and March 2016 at a single Tokyo hospital, compared the clinical background characteristics, complications, and 60-day mortality rates with positive peripheral blood cultures and positive semiquantitative cultures. MRSA carrier is defined as those with a history of MRSA detection by skin, urine, or sputum culture.Results: The median ages for the 17 MRSA and 19 MSSA patients were 72 and 55 years, respectively (P < 0.01). The occurrences of baseline disease (MRSA vs. MSSA) were 59% vs. 16% (P = 0.01), respectively, while those of complications, including septic shock, were 48% vs. 16% (P = 0.07), respectively. Catheter placement duration, time from fever onset to CVC removal, and time from fever onset to antimicrobial therapy initiation were similar in both groups. Sixty-day mortality rates were 35% and 5.3% (P = 0.04) in the MRSA and MSSA groups, respectively.Conclusion: MRSA carriers and older patients were at higher risks of CVC infection than MSSA bacteremia patients. Patients with MRSA bacteremia had higher septic shock and 60-day mortality rates despite appropriate antimicrobial therapy.

Highlights

Staphylococcus aureus bacteremia is mainly caused by central venous catheter (CVC) infection and is an important healthcare-associated infection [1,2]
We retrospectively investigated the data of all patients who tested positive for methicillin-resistant S. aureus (MRSA) or methicillin-sensitive S. aureus (MSSA) in peripheral blood cultures and semiquantitative cultures from CVC tip samples, taken within three days of the positive
Worse prognoses were found in MRSA bacteremia patients who were infected with a strain less susceptible to VCM (MIC 2.0 μg/mL), the minimum inhibitory concentration (MIC) of which is the upper limit of VCM susceptibility, compared with MRSA bacteremia patients infected with a VCM-susceptible strain (MIC < 1.0 μg/mL) [4,5,6,7,8]

Summary

Introduction

Staphylococcus aureus bacteremia is mainly caused by central venous catheter (CVC) infection and is an important healthcare-associated infection [1,2]. Other risk factors include solid tumors, chronic kidney disease, history of hospitalization, and prolonged antimicrobial use. 20-50% of S. aureus isolated in Japanese medical facilities is methicillin-resistant S. aureus (MRSA) [3]. The associated mortality rate of S. aureus bacteremia is 20-40%, and many studies have reported that MRSA bacteremia has a higher associated mortality rate than that of methicillin-sensitive S. aureus (MSSA) bacteremia [2]. Few studies have investigated the differences and prognoses of patients with MRSA and MSSA bacteremia secondary to CVC infection. We aimed to investigate the differences in clinical backgrounds, complications, and prognosis between MRSA and MSSA bacteremia secondary to CVC infection at St. Luke's International Hospital, Tokyo, Japan

Objectives

Methods

Results

Discussion

Conclusion