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Sepsis induced by Staphylococcus aureus: participation of biomarkers in a murine model.

de Oliveira TH, Amorin AT, Rezende IS, Santos Barbosa M, Martins HB, Brito AK, Andrade EF, Gonçalves GK, Campos GB, Silva RA, Timenetsky J, Marques LM - Med. Sci. Monit. (2015)

Bottom Line: However, there was a reduction of circulating neutrophils and monocytes after 96 hours of infection.On the other hand, infection with S. aureus did not promote visible change in histological tissue in the heart and kidneys.We believe our results may provide a better understanding of the pathophysiology, as well as aid in the search for a more reliable method of diagnosis.

View Article: PubMed Central - PubMed

Affiliation: Multidisciplinary Institute of Health, Federal University of Bahia, Vitória da Conquista, Brazil.

ABSTRACT

Background: This study aimed to evaluate the role of biomarkers in the pathophysiological process induced by a Staphylococcus aureus strain obtained in a hospital environment. For this, we intraperitoneally inoculated groups of male BALB/c mice with S. aureus, using a clinical isolate (CI) of S. aureus.

Material/methods: Mice were divided into groups according to time of euthanasia (24, 48, 72, 96, 120, 144, and 168 hours of infection). After being euthanized, blood samples were collected for quantification of microorganisms and leukocytes, as well as measurement of biomarkers of tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), C-reactive protein (CRP), and Procalcitonin (PCT) by ELISA. Heart, kidneys, and lungs were removed for histopathological analysis, assessment of biomarkers of tissue expression by RT-PCR (polymerase chain reaction with reverse transcriptase), and quantification of microorganisms by real-time quantitative PCR (real-time PCR).

Results: The animals infected at between 120 hours and 168 hours had the highest blood levels of S. aureus. We observed that infection promoted increases in the levels of circulating neutrophils and monocytes. However, there was a reduction of circulating neutrophils and monocytes after 96 hours of infection. The infected mice also had increased levels of blood lymphocytes. In this model of infection with S. aureus, IL-6, CRP, and PCT demonstrated greater fidelity as markers of infection, since serum levels were elevated and lowered along with the number of circulating neutrophils and monocytes after resolution of the infection. The lungs showed hyperemia, with enlargement of the alveolar septa. On the other hand, infection with S. aureus did not promote visible change in histological tissue in the heart and kidneys.

Conclusions: In this model of infection with S. aureus, IL-6, CRP, and PCT demonstrated greater fidelity as markers of infection, since serum levels were elevated and lowered along with the number of circulating neutrophils and monocytes after resolution of the infection. We believe our results may provide a better understanding of the pathophysiology, as well as aid in the search for a more reliable method of diagnosis.

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Representative photographs of lung tissue sections from male BALB/c mice infected with S. aureus. In the control group and 24 hours after infection, we observed clear alveoli without cellular infiltration. However, there was a marked hyperemia with more pronounced enlargement of the alveolar septa between 48 and 96 hours. It was less pronounced, but still present, at 144 hours and 168 hours. Arrows indicate enlarged alveolar septa.
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f8-medscimonit-21-345: Representative photographs of lung tissue sections from male BALB/c mice infected with S. aureus. In the control group and 24 hours after infection, we observed clear alveoli without cellular infiltration. However, there was a marked hyperemia with more pronounced enlargement of the alveolar septa between 48 and 96 hours. It was less pronounced, but still present, at 144 hours and 168 hours. Arrows indicate enlarged alveolar septa.

Mentions: No histological changes were observed in infected animals in the heart or kidneys (data not shown). These animals differed in the histological analysis of the lungs. In the control group and 24 hours after infection, we observed clear alveoli without cellular infiltration. However, there was marked hyperemia with more pronounced enlargement of the alveolar septa between 48 and 96 hours, and it was less pronounced, but still present, within 144 hours and 168 hours (Figure 8).


Sepsis induced by Staphylococcus aureus: participation of biomarkers in a murine model.

de Oliveira TH, Amorin AT, Rezende IS, Santos Barbosa M, Martins HB, Brito AK, Andrade EF, Gonçalves GK, Campos GB, Silva RA, Timenetsky J, Marques LM - Med. Sci. Monit. (2015)

Representative photographs of lung tissue sections from male BALB/c mice infected with S. aureus. In the control group and 24 hours after infection, we observed clear alveoli without cellular infiltration. However, there was a marked hyperemia with more pronounced enlargement of the alveolar septa between 48 and 96 hours. It was less pronounced, but still present, at 144 hours and 168 hours. Arrows indicate enlarged alveolar septa.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4321564&req=5

f8-medscimonit-21-345: Representative photographs of lung tissue sections from male BALB/c mice infected with S. aureus. In the control group and 24 hours after infection, we observed clear alveoli without cellular infiltration. However, there was a marked hyperemia with more pronounced enlargement of the alveolar septa between 48 and 96 hours. It was less pronounced, but still present, at 144 hours and 168 hours. Arrows indicate enlarged alveolar septa.
Mentions: No histological changes were observed in infected animals in the heart or kidneys (data not shown). These animals differed in the histological analysis of the lungs. In the control group and 24 hours after infection, we observed clear alveoli without cellular infiltration. However, there was marked hyperemia with more pronounced enlargement of the alveolar septa between 48 and 96 hours, and it was less pronounced, but still present, within 144 hours and 168 hours (Figure 8).

Bottom Line: However, there was a reduction of circulating neutrophils and monocytes after 96 hours of infection.On the other hand, infection with S. aureus did not promote visible change in histological tissue in the heart and kidneys.We believe our results may provide a better understanding of the pathophysiology, as well as aid in the search for a more reliable method of diagnosis.

View Article: PubMed Central - PubMed

Affiliation: Multidisciplinary Institute of Health, Federal University of Bahia, Vitória da Conquista, Brazil.

ABSTRACT

Background: This study aimed to evaluate the role of biomarkers in the pathophysiological process induced by a Staphylococcus aureus strain obtained in a hospital environment. For this, we intraperitoneally inoculated groups of male BALB/c mice with S. aureus, using a clinical isolate (CI) of S. aureus.

Material/methods: Mice were divided into groups according to time of euthanasia (24, 48, 72, 96, 120, 144, and 168 hours of infection). After being euthanized, blood samples were collected for quantification of microorganisms and leukocytes, as well as measurement of biomarkers of tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), C-reactive protein (CRP), and Procalcitonin (PCT) by ELISA. Heart, kidneys, and lungs were removed for histopathological analysis, assessment of biomarkers of tissue expression by RT-PCR (polymerase chain reaction with reverse transcriptase), and quantification of microorganisms by real-time quantitative PCR (real-time PCR).

Results: The animals infected at between 120 hours and 168 hours had the highest blood levels of S. aureus. We observed that infection promoted increases in the levels of circulating neutrophils and monocytes. However, there was a reduction of circulating neutrophils and monocytes after 96 hours of infection. The infected mice also had increased levels of blood lymphocytes. In this model of infection with S. aureus, IL-6, CRP, and PCT demonstrated greater fidelity as markers of infection, since serum levels were elevated and lowered along with the number of circulating neutrophils and monocytes after resolution of the infection. The lungs showed hyperemia, with enlargement of the alveolar septa. On the other hand, infection with S. aureus did not promote visible change in histological tissue in the heart and kidneys.

Conclusions: In this model of infection with S. aureus, IL-6, CRP, and PCT demonstrated greater fidelity as markers of infection, since serum levels were elevated and lowered along with the number of circulating neutrophils and monocytes after resolution of the infection. We believe our results may provide a better understanding of the pathophysiology, as well as aid in the search for a more reliable method of diagnosis.

Show MeSH
Related in: MedlinePlus