High prevalence of spa type t571 among methicillin-susceptible Staphylococcus aureus from bacteremic patients in a French University Hospital.

Isabelle Bonnet,Hélène Meugnier,Patricia Pavese,François Vandenesch,Sandrine Boisset,Max Maurin,Brune Millon,Herminia De Lencastre

doi:10.1371/journal.pone.0204977

Abstract

Staphylococcus aureus bacteremia is one of the most frequent severe bacterial infections worldwide, with an associated mortality of about 20–40% in developed countries. In 2013, we noted an increase in this infection in the teaching hospital in Grenoble, France, compared to 2012. The mean incidence of S. aureus bacteremia was 0.28 per 1,000 patient-days in 2012 and 0.35 per 1,000 patient-days in 2013. This trend was confirmed in 2014 (0.35 per 1,000 patient-days). In the present work we aimed to study the population of patients presenting with S. aureus bacteremia in 2013 and to genotype the corresponding S. aureus strains in order to identify a successful and/or virulent genotype to design a specific infection control program. One hundred ninety-one S. aureus isolates (including 9 methicillin-resistant) out of 199 corresponding cases of bacteremia were characterized with the spa typing method. Among 108 spa types, t571, t002, t008 and t084 were the most prevalent. Although not widely prevalent, t571 was the most frequently identified clone (8.4% of all isolates). Spa type t571 has been described in previous studies as belonging to the clonal complex CC398, which is consistent with the recent emergence of methicillin-susceptible S. aureus CC398 reported in blood cultures in Europe.

Highlights

Introduction100 000 population [1,2,3,4]
S. aureus bacteremia was defined as patients with at least one blood culture bottle, performed with the Bactec system (Becton Dickinson, USA) that was positive for S
In 2013, a large increase in S. aureus, mainly methicillin-susceptible, bacteremia was observed in our University Hospital compared to previous years (2012)

Summary

Introduction

100 000 population [1,2,3,4]. A 30-day mortality of 20% has been reported in developed countries [5]; the identification of the factors influencing its rise, both genetic and/or environmental, is of major importance for the prevention of this infection. The distribution of methicillin-resistant S. aureus (MRSA) clonal types has been well characterized across different geographic regions and care settings.

Objectives

Methods

Results

Conclusion