Molecular characteristics and predictors of mortality among Gram-positive bacteria isolated from bloodstream infections in critically ill patients during a 5-year period (2012–2016)

Abstract

To identify the molecular characteristics of Gram-positive cocci isolated from blood cultures and clinical outcome among critically ill patients. This retrospective study was conducted in the general intensive care unit of the University General Hospital of Patras, Greece, during a 5-year period (2012-2016). All adult patients with a Gram-positive BSI were included. PCR was applied to identify mecA gene (staphylococci); vanA, vanB, and vanC genes (enterococci). Linezolid-resistant S. epidermidis, MRSA, and VRE were further typed by multilocus sequence typing. Mutations in region V of 23S rDNA and ribosomal protein L4were investigated by PCR and sequencing analysis. The presence of the cfr gene was tested by PCR. In total, 141 Gram-positive BSIs were included. Coagulase-negative staphylococci predominated (n = 69; 65 methicillin-resistant, 23 linezolid-resistant carrying both C2534T and T2504A mutations and belonging to the ST22 clone), followed by enterococci (n = 46; 11 vancomycin-resistant carrying vanA gene, classified into four clones), S. aureus (n = 22; 10 methicillin-resistant, classified into three clones) and streptococci (n = 4). The most common type of infection was catheter-related (66; 46.8%), followed by primary BSI (28; 19.9%). Overall 14-day fatality was 24.8%. Multivariate analysis revealed septic shock as independent predictor of fatality, while appropriate empiric antimicrobial treatment and catheter-related BSI were identified as a predictor of good prognosis. Even though most of Gram-positive cocci were multidrug-resistant, fatality rate was low, associated with catheter-related BSIs. Among CNS, LR isolates represented one-third of BSIs due to the dissemination of ST22 S. epidermidis propagated by utilization of linezolid.

Global Expansion of Linezolid-Resistant Coagulase-Negative Staphylococci

“…This genetic lineage may be common not only in Russia and France. ST22 LRSE carrying the same mutations in 23S and rpl3 were reported from Greece and Turkey ( Karavasilis et al, 2015 ; Freitas et al, 2018 ; Papadimitriou-Olivgeris et al, 2020 ). The whole genome sequencing (WGS) data in the mentioned publication are lacking, and it is impossible to evaluate the level of similarity between ST22 isolates from different sources.…”

Clinical efficacy and safety of linezolid in intensive care unit patients

“…A 5-year retrospective study on Gram-positive bacteria isolated from bloodstream infections in critically ill patients found the SOFA score to be an independent risk factor for death in these infections. [35] There was no significant difference between the three treatment regimens involving glycopeptides, linezolid, and daptomycin.…”

Reduction of BSI associated mortality after a Sepsis Project implementation in the ER of a tertiary referral Hospital

“…However, over recent years, multidrug-resistant patterns in GP bacteria have resulted in di cult-to-treat infections, which in turn caused a current, overall increase of mortality [25]. Moreover, Staphylococcus aureus and coagulase-negative staphylococci, which were mostly isolated in our patients, are the leading cause of serious infections, such as endocarditis, with, furthermore, an increasing, high rate of methicillin resistance.…”