types of infections, including lung, urinary tract,
or bone infections. Bacteria against which these
antibiotics show activity include Escherichia
coli, Staphylococcus aureus, Streptococcus
pneumoniae (gentamicin and cefotaxime) and
Pseudomonas aeruginosa (gentamicin), These
bacteria can stimulate NETs release by
granulocytes (Halverson et al. 2015 ; Mori
et al. 2012 ). An interesting question arises of
whether the antibiotics used to treat infections
caused by bacteria triggering NETs release,
apart from exerting a direct antimicrobial effect,
could also modulate the antimicrobial strategy
employed by specialized phagocyting cells.
Under the experimental conditions of the
present study, gentamicin affected NETs release,
while cefotaxime did not. We observed a dimin-
ished formation of NETs after gentamicin treat-
ment in the stimulated neutrophils, regardless of
the kind of stimulus used, be it CI or PMA. We
demonstrate that the effect of antibiotics on
NETs release varies depending on the kind ofFig. 1 (a) Effects of gentamicin and cefotaxime on
NETs release from unstimulated (RPMI), and phorbol
myristate acetate (PMA) and calcium ionophore
(CI)-stimulated human neutrophils. DNA release was
measured fluorometrically in the presence of extracellular
DNA-binding dye Sytox green. The results represent
7 independent experiments performed in triplicates
(see Methods for details). (b-h) Fluorescence micros-
copy of NETs: (b) unstimulated neutrophils,
(c) PMA-stimulated neutrophils, (d) gentamicin-
pretreated PMA-stimulated neutrophils, (e) cefotaxime-
pretreated PMA-stimulated neutrophils, (f) CI-stimulated
neutrophils, (g) gentamicin-pretreated CI-stimulated
neutrophils, (h) cefotaxime-pretreated CI-stimulated
neutrophils. Gentamicin decreased whereas cefotaxime
did not influence NETs release from neutrophils. The
images represent three independent experiments using
blood from different donors;*p<0.05, **p<0.0150 A. Manda-Handzlik et al.