Bacterial DNA load in Staphylococcus aureus bacteremia is significantly higher in intravascular infections

An-Emmie Nieman; Wouter Rozemeijer; Paul H M Savelkoul; Rogier P Schade

doi:10.1371/journal.pone.0266869

Bacterial DNA load in Staphylococcus aureus bacteremia is significantly higher in intravascular infections

An-Emmie Nieman^*, Wouter Rozemeijer, Paul H M Savelkoul, Rogier P Schade

^*Corresponding author for this work

Research output: Contribution to journal › Article › Academic › peer-review

Abstract

OBJECTIVES: Determination of pathogen-specific bacterial DNA load (BDL) in blood has been shown to be directly correlated with severity of infection in patients with bacteremia. In the diagnostic work-up of patients with Staphylococcus aureus bacteremia (SAB), determination of the primary focus is imperative, because of implications for treatment duration, and ultimately prognosis. Here we investigate whether measurement of BDL in patients with SAB can distinguish between intravascular and extravascular foci of infection.

METHODS: In a consecutive cohort of 43 patients with positive blood cultures with Staphylococcus aureus, we performed a quantitative PCR on whole blood to detect the bacterial DNA load. Infections were classified into 3 categories: i) soft tissue infections and phlebitis, ii) deep-seated infections and iii) endocarditis and other intravascular infections. Bacterial DNA loads and inflammatory parameters in the three categories were analyzed and compared.

RESULTS: Median BDL in patients with endocarditis and other intravascular infections was 1015 cfu/ml, significantly higher than BDL in the other two categories (28 and 31 cfu/ml respectively). In contrast, CRP and leukocytes were not significantly different between the three patient categories. BDL could be detected in all patients with intravascular causes and levels were generally 10-30 times higher than in the other infection categories. Median BDL in non-survivors was 85 cfu/ml, which was higher than in survivors with a median BDL of 29 cfu/ml, although not significant.

CONCLUSIONS: In Staphylococcus aureus bacteremia pathogen-specific BDL is distinctly higher in patients with intravascular infections compared to extravascular origins. As measurement of BDL by PCR can easily be implemented in routine diagnostics, it can improve the diagnostic work-up of SAB by rapidly identifying the subset of patients who need higher dosages of antibiotics and additional measures to improve outcome.

Original language	English
Article number	e0266869
Number of pages	9
Journal	PLOS ONE
Volume	17
Issue number	4
DOIs	https://doi.org/10.1371/journal.pone.0266869
Publication status	Published - 20 Apr 2022

Keywords

Bacteremia/diagnosis
DNA, Bacterial/genetics
Endocarditis
Humans
Real-Time Polymerase Chain Reaction
Staphylococcal Infections/microbiology
Staphylococcus aureus/genetics
MORTALITY
DIAGNOSIS
MANAGEMENT
TIME
POSITIVITY
SEVERITY
BLOOD

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Cite this

@article{8ba75da7cad147d7995d15419c31b791,

title = "Bacterial DNA load in Staphylococcus aureus bacteremia is significantly higher in intravascular infections",

abstract = "OBJECTIVES: Determination of pathogen-specific bacterial DNA load (BDL) in blood has been shown to be directly correlated with severity of infection in patients with bacteremia. In the diagnostic work-up of patients with Staphylococcus aureus bacteremia (SAB), determination of the primary focus is imperative, because of implications for treatment duration, and ultimately prognosis. Here we investigate whether measurement of BDL in patients with SAB can distinguish between intravascular and extravascular foci of infection.METHODS: In a consecutive cohort of 43 patients with positive blood cultures with Staphylococcus aureus, we performed a quantitative PCR on whole blood to detect the bacterial DNA load. Infections were classified into 3 categories: i) soft tissue infections and phlebitis, ii) deep-seated infections and iii) endocarditis and other intravascular infections. Bacterial DNA loads and inflammatory parameters in the three categories were analyzed and compared.RESULTS: Median BDL in patients with endocarditis and other intravascular infections was 1015 cfu/ml, significantly higher than BDL in the other two categories (28 and 31 cfu/ml respectively). In contrast, CRP and leukocytes were not significantly different between the three patient categories. BDL could be detected in all patients with intravascular causes and levels were generally 10-30 times higher than in the other infection categories. Median BDL in non-survivors was 85 cfu/ml, which was higher than in survivors with a median BDL of 29 cfu/ml, although not significant.CONCLUSIONS: In Staphylococcus aureus bacteremia pathogen-specific BDL is distinctly higher in patients with intravascular infections compared to extravascular origins. As measurement of BDL by PCR can easily be implemented in routine diagnostics, it can improve the diagnostic work-up of SAB by rapidly identifying the subset of patients who need higher dosages of antibiotics and additional measures to improve outcome.",

keywords = "Bacteremia/diagnosis, DNA, Bacterial/genetics, Endocarditis, Humans, Real-Time Polymerase Chain Reaction, Staphylococcal Infections/microbiology, Staphylococcus aureus/genetics, MORTALITY, DIAGNOSIS, MANAGEMENT, TIME, POSITIVITY, SEVERITY, BLOOD",

author = "An-Emmie Nieman and Wouter Rozemeijer and Savelkoul, {Paul H M} and Schade, {Rogier P}",

note = "Publisher Copyright: Copyright: {\textcopyright} 2022 Nieman et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.",

year = "2022",

month = apr,

day = "20",

doi = "10.1371/journal.pone.0266869",

language = "English",

volume = "17",

journal = "PLOS ONE",

issn = "1932-6203",

publisher = "Public Library of Science",

number = "4",

}

TY - JOUR

T1 - Bacterial DNA load in Staphylococcus aureus bacteremia is significantly higher in intravascular infections

AU - Nieman, An-Emmie

AU - Rozemeijer, Wouter

AU - Savelkoul, Paul H M

AU - Schade, Rogier P

N1 - Publisher Copyright: Copyright: © 2022 Nieman et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

PY - 2022/4/20

Y1 - 2022/4/20

N2 - OBJECTIVES: Determination of pathogen-specific bacterial DNA load (BDL) in blood has been shown to be directly correlated with severity of infection in patients with bacteremia. In the diagnostic work-up of patients with Staphylococcus aureus bacteremia (SAB), determination of the primary focus is imperative, because of implications for treatment duration, and ultimately prognosis. Here we investigate whether measurement of BDL in patients with SAB can distinguish between intravascular and extravascular foci of infection.METHODS: In a consecutive cohort of 43 patients with positive blood cultures with Staphylococcus aureus, we performed a quantitative PCR on whole blood to detect the bacterial DNA load. Infections were classified into 3 categories: i) soft tissue infections and phlebitis, ii) deep-seated infections and iii) endocarditis and other intravascular infections. Bacterial DNA loads and inflammatory parameters in the three categories were analyzed and compared.RESULTS: Median BDL in patients with endocarditis and other intravascular infections was 1015 cfu/ml, significantly higher than BDL in the other two categories (28 and 31 cfu/ml respectively). In contrast, CRP and leukocytes were not significantly different between the three patient categories. BDL could be detected in all patients with intravascular causes and levels were generally 10-30 times higher than in the other infection categories. Median BDL in non-survivors was 85 cfu/ml, which was higher than in survivors with a median BDL of 29 cfu/ml, although not significant.CONCLUSIONS: In Staphylococcus aureus bacteremia pathogen-specific BDL is distinctly higher in patients with intravascular infections compared to extravascular origins. As measurement of BDL by PCR can easily be implemented in routine diagnostics, it can improve the diagnostic work-up of SAB by rapidly identifying the subset of patients who need higher dosages of antibiotics and additional measures to improve outcome.

AB - OBJECTIVES: Determination of pathogen-specific bacterial DNA load (BDL) in blood has been shown to be directly correlated with severity of infection in patients with bacteremia. In the diagnostic work-up of patients with Staphylococcus aureus bacteremia (SAB), determination of the primary focus is imperative, because of implications for treatment duration, and ultimately prognosis. Here we investigate whether measurement of BDL in patients with SAB can distinguish between intravascular and extravascular foci of infection.METHODS: In a consecutive cohort of 43 patients with positive blood cultures with Staphylococcus aureus, we performed a quantitative PCR on whole blood to detect the bacterial DNA load. Infections were classified into 3 categories: i) soft tissue infections and phlebitis, ii) deep-seated infections and iii) endocarditis and other intravascular infections. Bacterial DNA loads and inflammatory parameters in the three categories were analyzed and compared.RESULTS: Median BDL in patients with endocarditis and other intravascular infections was 1015 cfu/ml, significantly higher than BDL in the other two categories (28 and 31 cfu/ml respectively). In contrast, CRP and leukocytes were not significantly different between the three patient categories. BDL could be detected in all patients with intravascular causes and levels were generally 10-30 times higher than in the other infection categories. Median BDL in non-survivors was 85 cfu/ml, which was higher than in survivors with a median BDL of 29 cfu/ml, although not significant.CONCLUSIONS: In Staphylococcus aureus bacteremia pathogen-specific BDL is distinctly higher in patients with intravascular infections compared to extravascular origins. As measurement of BDL by PCR can easily be implemented in routine diagnostics, it can improve the diagnostic work-up of SAB by rapidly identifying the subset of patients who need higher dosages of antibiotics and additional measures to improve outcome.

KW - Bacteremia/diagnosis

KW - DNA, Bacterial/genetics

KW - Endocarditis

KW - Humans

KW - Real-Time Polymerase Chain Reaction

KW - Staphylococcal Infections/microbiology

KW - Staphylococcus aureus/genetics

KW - MORTALITY

KW - DIAGNOSIS

KW - MANAGEMENT

KW - TIME

KW - POSITIVITY

KW - SEVERITY

KW - BLOOD

U2 - 10.1371/journal.pone.0266869

DO - 10.1371/journal.pone.0266869

M3 - Article

C2 - 35443013

SN - 1932-6203

VL - 17

JO - PLOS ONE

JF - PLOS ONE

IS - 4

M1 - e0266869

ER -