New therapy of pleural empyema by deoxyribonuclease

Beyond the double helix: the multifaceted landscape of extracellular DNA in Staphylococcus aureus biofilms

Staphylococcus aureus forms biofilms consisting of cells embedded in a matrix made of proteins, polysaccharides, lipids, and extracellular DNA (eDNA). Biofilm-associated infections are difficult to treat and can promote antibiotic resistance, resulting in negative healthcare outcomes. eDNA within the matrix contributes to the stability, growth, and immune-evasive properties of S. aureus biofilms. eDNA is released by autolysis, which is mediated by murein hydrolases that access the cell wall via membrane pores formed by holin-like proteins. The eDNA content of S. aureus biofilms varies among individual strains and is influenced by environmental conditions, including the presence of antibiotics. eDNA plays an important role in biofilm development and structure by acting as an electrostatic net that facilitates protein-cell and cell-cell interactions. Because of eDNA's structural importance in biofilms and its ubiquitous presence among S. aureus isolates, it is a potential target for therapeutics. Treatment of biofilms with DNase can eradicate or drastically reduce them in size. Additionally, antibodies that target DNABII proteins, which bind to and stabilize eDNA, can also disperse biofilms. This review discusses the recent literature on the release, structure, and function of eDNA in S. aureus biofilms, in addition to a discussion of potential avenues for targeting eDNA for biofilm eradication.

A combined intrapleural administration of dornase alfa and tissue plasminogen activator is safe in children with empyema - A pilot study

OBJECTIVE

There is still no consensus regarding the treatment of empyema in children. Intrapleural combination of tissue plasminogen activator and dornase alfa is a promising treatment for empyema in adults. The aim of this pilot study was to determine whether this combination is safe and successful in pediatric empyema.

METHODS

Previous well children diagnosed with empyema as classified by the British Thoracic Society. After chest tube insertion, intrapleurally dornase alfa 2.5 mg for 2 days and tissue plasminogen activator 0.15 mg/kg for 3 days was given after which the chest tube was clamped for 4 h. Primary outcome was safety.

RESULTS

Ten consecutive children were included (4 boys, aged 3.2 (1.3-15.0) years old). No serious adverse events were seen. One child developed urticaria but additional intervention or cessation of the trial was not needed. There was no bleeding or mortality and no additional procedures were performed. The median hospital stay after intervention was 7.5 days.

CONCLUSIONS

The intrapleural treatment of dornase alfa and tissue plasminogen activator as treatment of empyema was safe in ten children with empyema. If confirmed in further studies, this combination of intrapleural therapy may improve the management of pediatric empyema.

Alteplase and DNase for the treatment of pleural empyema in rats

BACKGROUND AND OBJECTIVES

Adjunctive intrapleural fibrinolytic is an option to treat empyema at fibrinopurulent stage, but there is controversy about which should be use. Our objective is to evaluate the action of alteplase and/or desoxyribonuclease at physical and chemical properties in vitro pus derived from an experimental induced empyema in rats.

METHODS

Streptococcus pneumoniae was introduced into the pleural cavity by thoracentesis through pleural pressure monitor. Animals were euthanized after 24 h, with macroscopic thoracic evaluation and measurement of amount of intrapleural liquid that was posteriorly stored at -80 °C. Selected samples were randomly distributed into four groups, then thawed at room temperature before exposure to one of the following: G1 = alteplase (n = 12), G2 = DNase (n = 12), G3 = alteplase + DNase (n = 12), or G4 = saline (n = 6). The mean molecular size in the fluid portion of the empyema was evaluated using dynamic light scattering; viscosity of the empyema fluid was measured using the drip method.

RESULTS

Macroscopic showed purulent liquid, with fibrin and septation, with mean volume of 4.16 ml (0.5-8 ml). All samples were culture-positive for Streptococcus pneumoniae. Comparing with control, all experimental groups presented reduction of larger than 135 nm molecular size, but there was only significant difference with alteplase (p = 0,02). Viscosity reduced at all experimental groups, but increased at control. DNase group presented negative median (-5 mPa/s) of viscosity, and differed significantly from that observed in the control group (p = 0.04).

CONCLUSIONS

Alteplase, DNase and alteplase + DNase changed significantly physical and chemical properties of experimental empyema at fibrinopurulent phase: alteplase reduced molecular size larger than 135 nm and DNase reduced viscosity.

Intrapleural administration of DNase alone for pleural empyema

INTRODUCTION

Pleural empyema is a severe complication of various diseases. The essential is the inserting a drain into the pleural cavity and evacuation of the pus. Sometimes the pus is very thick and its evacuation and re-expansion of the lung is very difficult.

METHODS

We report a group of 10 patients with intrapleural administration of Pulmozyme (dornase alpha) in dosages of either 2.5 mg once or on two separate occasions. All of the patients had a chest tube inserted into the pleural cavity. Measurement of viscosity was done before and after the instillation of the dornase alpha.

RESULTS

In six patients dornase alfa was introduced into the pleural cavity once. Three of them received this on the 4th whilst the rest were treated with the agent on the 6th day. Four patients received the dornase alpha twice because of the small amount of drainage fluid after the previous instillation. Five patients were discharged from hospital with complete re-expansion of their lungs. Two patients were qualified for a surgical operation since the lung was trapped and did not re-expand. Three patients had to be discharged with a drain as a result of incomplete re-expansion of the lung. In all the patients the density of the pus after administering the dornase alpha decreased and the amount of the pus drainage increased.

CONCLUSIONS

Dornase alpha may be used in some patients with pleural empyema with good results.