RESEARCH ARTICLEActa Medica Marisiensis 201763(2):91-96 [615243]

RESEARCH ARTICLEActa Medica Marisiensis 2017;63(2):91-96
DOI: 10.1515/amma-2017-0020
Flow Cytometry Assessment of Bacterial and
Yeast Induced Oxidative Burst in Peripheral Blood
Phagocytes
Floredana-Laura Șular1,2*, Minodora Dobreanu1,2
1 Discipline of Laboratory Medicine, University of Medicine and Pharmacy of Tîrgu Mureș, Romania
2 Central Laboratory, Emergency Clinical County Hospital of Tîrgu Mureș, Romania
Objective : The aim of this study was to verify in our laboratory conditions the performance criteria of a commercial kit (PhagoburstTM, Glyco –
tope Biotechnology) as described by the producers. We have also partially altered the use of the available kit by introducing a non-opsonized
Candida albicans stimulus, in addition to the opsonized Escherichia coli stimulus provided by the manufacturer. Material and methods : The
peripheral blood samples of 6 clinically healthy adults were tested in triplicate according to the manufacturer recommendations. The intra-
assay imprecision as well as the ranges of neutrophil and monocyte burst activation triggered by various stimuli were assessed. Results : The
activation range of granulocytes and monocytes was similar to the one described by the producer in the presence of E. coli (granulocytes:
78.45-99.43% versus 99.6-99.95%, average %CV of 1.53% versus 0.1%, monocytes: 54.63-92.33% versus 81.80-96.67, average %CV
6.92% versus 1.1%). The leukocyte range of activation in the presence of non-opsonized C. albicans was comparable to the one triggered
by the fMLP (N-formyl-methionyl-leucyl-phenylalanine) stimulus. Conclusion : The intra-assay precision obtained in our laboratory conditions,
as well as the ranges of activated leukocytes, are comparable to the ones described by the producer when using E. coli as a stimulus. The
present study shows that introducing an extra fungal stimulus for burst oxidation assessment could provide additional information regarding
the non-specific cellular immune response, particularly in patients at risk for candidemia.
Keywords : flow cytometry, method verification, intra-assay precision, reactive oxygen species, fungal bloodstream infection
Received 23 April 2017 / Accepted 4 June 2017
Introduction
The peripheral blood phagocytes (PBP) have long been ac –
knowledged as key factors in bacterial and fungal infections.
As first line of defense, they phagocyte and kill microorgan –
isms through a combination of mechanisms that include
the production of reactive oxygen species (ROS) [1].
Along the years, flow cytometry methods have been de –
veloped in order to quantify the production of ROS using
bacteria as stimulus [2,3]. Different authors have described
methods for burst oxidation assessment in peripheral
blood mononuclear cells (PBMC) using isolated leuko –
cytes and different strains of Candida as stimuli as well as
different incubation periods [4-8]. Recent years have seen
the development of several commercial kits that use whole
blood, not isolated PBMC as many methods used before,
and unlabeled opsonized Escherichia coli as stimulus for
PBP activation besides other chemical stimulants [9]. Up
to the present moment none of the available commercial
kits used fungi as stimulus.
The aim of the present study was to verify in our labora –
tory conditions the performance criteria of the commercial
kit Phagoburst TM (Glycotope Biotechnology) as recom –
mended by the producers. We have also partially altered
the use of the available kit by introducing a non-opsonized
Candida albicans suspension for testing as stimulus with
the purpose to assess the cellular immune response in fun –
gal bloodstream infections.Materials and methods
We conducted a study that aimed to verify the performance
parameters of the Phagoburst TM (Glycotope, Biotechnology)
commercial kit in our laboratory conditions and to vali –
date as well the use of a new stimulus – a non-opsonized
C. albicans suspension in order to verify the PBP innate
immune response to fungal stimuli.
The study was conducted according to the World Medi –
cal Association Declaration of Helsinky and was approved
by the Ethics Committee of the Emergency Clinical Coun –
ty Hospital of Tîrgu Mureș, No.19204/29th of September
2014 as well as the Ethics Committee of the University of
Medicine and Pharmacy of Tîrgu Mureș, No.53/22nd of
April 2015. Informed consent was given by each enrolled
adult.
Blood samples
Whole venous blood specimens were collected from 6
healthy adults on BD sodium heparin tubes as recom –
mended by the producers of the Phagoburst TM (Glycotope
Biotechnology) commercial kit. The volunteers were cho –
sen by absence of infectious history and clinical signs of
infection. All samples were tested in triplicate within one
hour after collection, being kept meanwhile on a covered
ice bath.
Assay for the evaluation of cell burst activity
Phagoburst TM was created to investigate the altered oxi –
dative burst activity present in various pathologies and to
evaluate the effects of drugs. It allows quantitative assess -* Correspondence to: Floredana-Laura Șular
E-mail: floredana.sular@gmail.com

92
ment of PBP oxidative burst. The kit contains an unla –
beled opsonized E. coli bacteria as particulate stimulus, the
protein kinase C ligand phorbol 12-myristate 13-acetate
(PMA) as high stimulus, the chemotactic peptide N-for –
myl-MetLeuPhe (fMLP) as low physiological stimulus,
dihydrorhodamine 123 (DHR 123) as a fluorogenic sub –
strate and necessary reagents.
In order to quantify the production of ROS by PBP
that could be triggered by a fungal pathogen in neonates
which are known to have low opsonin concentration and
degree of activation [10], we introduced an extra fungal
stimulus for testing in the form of a C. albicans yeast sus –
pension. The reference strain C. albicans ATCC 10321 was
cultured aerobically on Sabouraud chloramphenicol agar
for 18 hours at 35°C. An 0.5 optical density inoculum of
C. albicans (approximate cell concentration of 1-5 x 106
colony forming units/mL) was prepared for each testing
round by Using Vitek2 Densichek densitometer (Biomer –
ieux, France). The yeast suspension was not exposed to any
supplementary opsonins then those present in the 100 μL
whole blood used for testing. The yeast cells underwent
no inactivation prior to exposure to whole blood. May
Grunwald Giemsa stained blood smears performed after
a 10 minutes period of incubation of whole blood with
the yeast stimulus showed no budding, pseudohyphae or
hyphal growth.
Heparinized whole blood (100 μL) within 1 hour after
sampling was incubated with 20 μl of each of the above
mentioned stimuli for 10 minutes at 37°C on a water
bath. The ROS produced during the oxidative burst by
the phagocytes was monitored by oxidation of 20 μl DHR
123 which served as an oxidative fluorogenic substrate. A
volume of 2 ml lysing solution which removed the eryth –
rocytes and resulted in a partial fixation of the leukocytes
was added to stop the burst oxidation reaction. After cen –
trifugation and one washing step, 200 μL DNA staining
solution was added to exclude aggregation artifacts of bac –
teria, fungi or cells. The DNA staining required 10 min –
utes incubation at 0°C, protected from light. Samples were
thus ready for FACS analysis that was performed within 30
minutes following DNA staining.
Flow cytometry analysis
Each blood sample was tested in triplicate. Cells were ana –
lyzed by flow cytometry using a 488 nm argon-ion excita –
tion laser. As recommended by the producer, during data
acquisition a “live gate” was set in the red fluorescence his –
togram on the events that had at least the same DNA con –
tent as a human diploid cell with the purpose of preclud –
ing bacteria or fungi aggregates that had the same scatter
light properties as the leukocytes from analysis. An average
number of 15000 leukocytes per sample were collected.
The percentage of cells that produced ROS (recruit –
ment) as well as their mean fluorescence intensity (MFI)
(activity, amount of cleaved substrate) was quantified. The
relevant leukocyte cluster was gated in the software pro -gram in the scatter diagram (linear FSC vs linear SSC) and
its rhodamine 123 green fluorescence was collected in the
FL1 channel (standard FITC filter set) and analyzed. A
negative control sample without any stimulus was always
run as a negative background control to set a marker for
fluorescence (FL1) so that less than 3% of the events were
positive. The percentage of activated cells in the test sam –
ples was then set by counting the number of events above
this threshold. The mean fluorescence correlates with oxi –
dation quantity per individual leukocyte.
Data collection and analysis
Results for every round of tests of each replicate of the six
samples were collected. For data entry and analysis Micro –
soft Excel® (Microsoft Corporation, Redmond, WA, USA)
and its tools were used. The coefficient of variance of each
sample, as well as the minimum-maximum range of the
percentage of activated cells and their MFI was assessed for
each of the used stimuli.
Results
Figure 1 shows the “live gate” (viability assessment) set on
leukocyte DNA which is meant to distinguish between
those events which have at least the same DNA content as
a human diploid cell thus excluding aggregates of bacteria
and fungi having the same scatter light properties as the
leukocytes. Leukocyte viability decreases as burst oxida –
tion intensity triggered by the used stimuli increases: vi –
ability of the negative control tube (97.87%) is followed
by opsonized E. coli as particulate stimulus (70.43%) and
then by the protein kinase C ligand PMA as high stimulus
(45.93%).

Fig. 1. Viability of assessed leukocyte population of the control
sample (green), compared to the cell viability of the samples that
were exposed to E. coli (blue) and PMA (red). A “live” gate (M2)
was set on those events that have at least the same DNA con –
tent as a human diploid cell with the purpose of precluding from
analysis bacteria or fungi (M1) which had the same scatter light
properties as the leukocytes.Șular Floredana-Laura et al. / Acta Medica Marisiensis 2017;63(2):91-96

93
Fig. 2. Flow cytometry analysis results. Row 1 displays the typical FSC/SSC dot plots when adult PBP cells are stimulated with E. coli
(1A), fMLP (1B), PMA (1C) and C. albicans (1D) (gate set on granulocyte and monocyte populations). Row 2 displays the dot plot lin SSC/
log FL1-R123 of test samples stimulated with E. coli (2A), fMLP (2B), PMA (2C) and C. albicans (2D). Row 3 shows the typical FL1-DHR123
histogram that depicts granulocyte activation of the control sample (pink) compared to activation triggered by E. coli (blue) (3A), fMLP
(green)(3B), PMA (red)(3C) and C. albicans (black) (3D). Row 4 illustrates the typical FL1-DHR123 histogram that shows monocyte activa –
tion of the control sample (violet) compared to burst activation triggered by E. coli (blue) (4A), fMLP (green)(4B), PMA (red)(4C) and C.
albicans (black) (4D).1A 1B 1C 1D
3A 3B 3C 3D2A 2B 2C 2D
4A 4B 4C 4D
Figure 2 row 1 presents typical FSC/SSC dot plot sets of
one of the tested subjects. The gate is set on granulocytes
and monocytes stimulated with E. coli (1A), fMLP (1B),
PMA (1C) and C. albicans (1D).
Figure 2 row 2 displays the degree of granulocyte (R2)
and monocyte (R3) activation (recruitment) and produc –
tion of ROS when using the same stimuli as mentioned
above. E. coli (2A) and PMA (2C) trigger a similar intense
PBP activation, while the burst activation triggered by the unopsonized C. albicans (2D) is similar to the one gener –
ated by the presence of low fMLP stimulus (2B). The burst
activity (amount of DHR 123 cleaved substrate) of the two
studied leukocyte populations was also quantified as mean
fluorescence intensity (MFI) for each stimulus as depicted
in Figure 2 3A, 3B, 3C, 3D for granulocytes, and Figure 2
4A, 4B, 4C, 4D for monocytes.
T able I shows the activation range of granulocytes and
monocytes as percentages and MFI when verifying in our Șular Floredana-Laura et al. / Acta Medica Marisiensis 2017;63(2):91-96

94
laboratory the intra-assay precision, as well as the average
CV that resulted after testing in triplicate each of the 6
whole blood samples as recommended by the producers.
The activation range of granulocytes and monocytes,
though having a broader lower limit in our laboratory con –
ditions, was similar to the one described by the producer
in the presence of E. coli (granulocytes: 78.45-99.43%
versus 99.6-99.95%, average %CV of 1.53% versus 0.1%,
monocytes: 54.63-92.33% versus 81.80-96.67, average
%CV 6.92% versus 1.1%).
We obtained similar ranges of activation as the produc –
ers did for fMLP and PMA in the case of granulocytes,
while for monocytes data for these stimuli were not pro –
vided by the producer.
When assessing the PBP burst oxidation triggered by
C. albicans , our data revealed acceptable variation of mean
%CV for granulocytes (6.46% for oxidizing cells and
7.54% for MFI). Due to low monocytes activation, dur –
ing the 20 minutes incubation time, the resulting average
%CV showed higher but acceptable values for validation
(8.80 % for oxidizing cells and 11.61% for MFI).
Discussion
The Phagoburst TM (Glycotope Biotechnology) kit that we
used for our study is already validated for in vitro diag –
nostic testing with the above mentioned stimuli. Accord –
ing to professional standards, it is recommended that the
performance criteria of each test to be verified in the user’s
own laboratory conditions. We performed this verifica –
tion and then we tried to validate a new fungal stimulus by quantifying the intra-assay imprecision and the ranges
of neutrophil and monocyte burst activation triggered by
various stimuli.
According to the Practice guidelines from the ICSH
and ICCS-part V- Assay performance criteria [11] recom –
mended for validation of cell-based fluorescence assays, for
the quantification of the intra assay imprecision, we used
the same assay matrix (whole blood) originating from 6
patients (a minimum of 5 samples being required) tested in
triplicate in a single analytical run [12]. We used samples
only from healthy patients due to the laboratory’s inability
to access samples from patients with altered oxidative burst
activity such as chronic granulomatous disease. We made
this choice in order to be also able to compare our labora –
tory’s results to the ones provided by the producer of the
commercial kit which tested only healthy subjects.
The mean and %CV for each sample tested in tripli –
cate was calculated. As recommended [12], percent CV
(%CV), rather than standard deviation (SD) was used as
acceptance criteria due to the fact that %CV normalizes
variations at lower levels of event detection as it happened
in our case of monocyte activation when using the low
stimuli fMLP and C. albicans .
The level of acceptable imprecision in flow cytometry
techniques for an reportable result depends upon the fre –
quency of the population and the total number of events
acquired [13]. As stated by the guidelines [11], a desir –
able target for assay imprecision is a CV of less than 10%,
while for less abundant populations (frequency at 1:1000
(0.1%)) a CV of less than 20% is acceptable [14].
Table I. Verification performance parameters of the PhagoburstTM Glycotope Biotechnology commercial kit
Cell Type StimulusOxidizing cells (%) GeoMean FL1 (MFI)
Producer Own Laboratory Producer Own Laboratory
  E. coli (min-max) 99.6-99.95 78.45-99.43 154.5-395.75 400-735
  mean   91.96   538
  average CV 0.1  1.53  4.8% 6.84%
  fMLP (min-max) 1-10  1.53-12.95   320-496
  Mean 6.35 NA 387
Granulocytes average CV  NA 18.61   4.08%
  PMA (min-max) 98-100 95.83-99.77 300-1000 907-1528
  Mean   98.57   1215
  average CV  NA 0.78  NA 6.21%
  C. albicans (min-max)   2.18-8.80   371-519
  mean NA 5.68 NA 458
  average CV   6.46   7.54
  E. coli (min-max) 81.80-96.67 54.63-92.33 49.60-88.65 278-349
  mean   69.18   307
  average CV  1.1 6.92  6.5% 5.57%
  fMLP (min-max)   0.61-4.52   236-410
  mean NA 2.14 NA 283
Monocytes average CV   56.59   18.23
  PMA (min-max)   29.15-95.89   285-383
  mean NA 70.89 NA 356
  average CV   7.57   4.41
  C. albicans (min-max)   1.04-10.63   239-347
  mean NA 3.6 NA 299
  average CV   8.80   11.61
CV= coefficient of variance (mean of the %CV), min=minimum value, max= maximum value, NA= non-available, MFI=mean fluorescence intensityȘular Floredana-Laura et al. / Acta Medica Marisiensis 2017;63(2):91-96

95
The results obtained in our own laboratory conditions
for the intra-assay precision are acceptable according to the
guidelines [11] when assessing the %CV of oxidizing gran –
ulocytes and monocytes in the presence of E.coli , PMA
and C. albicans . Also the ranges of values for oxidizing leu –
kocytes that we obtained when assessing imprecision were
similar to the ones described by the producer though hav –
ing an acceptable lower reference range.
We did get a high %CV for granulocyte and monocyte
activation as well as a high %CV for monocyte MFI when
fMLP was used as stimulus. This situation that can be
easily explained by the fact that considering the very low
degree of PBP activation, very small variations generated
large %CVs. Nevertheless, a value for fMLP %CV hasn’t
been provided for comparison not even by the kit manu –
facturer. A borderline value of 11.61%, slightly above the
acceptable criteria, was also obtained for the MFI in the
case of C. albicans .
When examining the MFI, in our laboratory conditions
and flow cytometer settings, the value ranges, thought
proportional to the ones described by the producer, were
higher. It is one of the producer’s recommendations that
laboratories should establish their own normal reference
ranges using their own testing conditions.
In the experiment we conducted in healthy adults, the
particulate opsonized stimulus E. coli generated a similar
activation of the PBP as the high stimulus (PMA), though
with larger lower ranges in our laboratory conditions. MFI
in our experiment, as described by the producer, reached
higher values when PMA was used in comparison to the
opsonized particulate stimulus E. coli .
The burst activation generated by incubation with C. albi –
cans was similar in granulocytes and slightly lower in mono –
cytes than the one generated by the low stimulus (fMLP).
C. albicans can reside as a lifelong commensal on or
within the human host for a long time. Still, literature
describes a number of pathogenic mechanisms that render
C. albicans virulent when alterations in the host environ –
ment occur [15]. One of these mechanisms is represented
by the robust stress response C. albicans displays against
the oxidative and nitrosative stresses of the phagocyte cells
[16,17]. Studies show that C. albicans mutants that lack
genes that encode regulators of stress response or detoxify –
ing enzymes have an attenuated virulence [18]. The ability
of C. albicans to produce antioxidant enzymes like catalase
Cta1 as well as the intracellular and extracellular superox –
ide dismutases (Sods) to counteract the respiratory burst
[17,19], represents a viable explanation of the low activa –
tion and ROS production by neutrophils and monocytes
in our study. Previous studies have shown that Sod1 in –
teracts with macrophages while Sod2 is required to resist
neutrophil attack [19]. Sod4, Sod5 [20] and Sod6, along
with the catalase Cta1 detoxify extracellular ROS pro –
duced by macrophages [21].
According to previous studies described by Mayer at
al. [17], due to quorum sensing, a low yeast density (<107 cells/mL), as in our case (1-5 x 106 cells/mL), favours hy –
phal formation. Though we did not submit the C. albicans
yeast cells to any inactivation process prior to whole blood
exposure, the smears performed after 10 minutes of incuba –
tion at 37°C showed no budding, pseudohyphae or hyphal
growth. Still, hyphae could have formed during the next
10 minutes of incubation with the DHR123 prior to burst
oxidation assessment. Studies have shown that regardless of
the fungal morphology, Sods are expressed: yeast cells ex –
press Sod4 while hyphal forms express Sod5. Neutrophils
also induce the expression of Sod5 although they inhibit
the yeast-to-hyphal formation in C. albicans [19,20].
Other studies have shown the enhanced capacity of the
human neutrophils from healthy patients in the presence
of opsonins to inhibit germination of C. albicans into clus –
ters of hyphae in overnight assays as well as to kill Candida
conidia (2 hours). The killing of the unopsonized C. albi –
cans was found to be dependent solely on the complement
receptor 3 (CR3) and the signaling proteins phosphati –
dylinositol-3-kinase and caspase recruitment domain-con –
taining protein 9 (CARD9), but completely independent
of NADPH oxidase activity, as opposed to opsonized C.
albicans whose killing was dependent upon production of
ROS by the NADPH oxidase system [22].
Consequently, all these mechanism could explain the
low production of ROS by phagocytes in the presence of
unopsonized C. albicans.
Study limitations
The lack of supplementary opsonins in our study in the case
of C. albicans stimulus , coupled with the relatively short
incubation time (20 minutes), compared to other studies
that used isolated PBMC might have led to a lower degree
of burst activation than in the case of opsonized E. coli .
Conclusions
The performance parameters for the Phagoburst TM (Gly –
cotope Biotechnology) kit obtained in our laboratory com –
pared to the ones provided by the producer as well as
the professional guidelines allow us to safely use the kit
for burst oxidation assessment in human PBP . Our study
suggests also that introducing an extra fungal stimulus
for burst oxidation assessment could provide additional
information regarding the non-specific cellular immune
response, particularly in patients at risk for fungal blood –
stream infection.
Acknowledgements
This study was partially financed by Internal Research
Grants of the University of Medicine and Pharmacy of
Tîrgu Mureș, Romania, Project number 15/23.12.2014.
Conflict of interests
The authors declared no potential conflicts of interest with
respect to this research, authorship and/or publication of
this article.Șular Floredana-Laura et al. / Acta Medica Marisiensis 2017;63(2):91-96

96
References
1. Fradin C, De Groot P , MacCallum D, Schaller M, Klis F, Odds FC, et
al. Granulocytes govern the transcriptional response, morphology and
proliferation of Candida albicans in human blood. Mol Microbiol 2005 Feb
18,56(2):397–415.
2. Gille C, Leiber A, Mundle I, Spring B, Abele H, Spellerberg B, et al.
Phagocytosis and postphagocytic reaction of cord blood and adult
blood monocyte after infection with green fluorescent protein-labeled
Escherichia coli and group B Streptococci. Cytom Part B – Clin Cytom
2009,76(4):271–84.
3. Martin E, Bhakdi S. Flow cytometric assay for quantifying
opsonophagocytosis and killing of Staphylococcus aureus by peripheral
blood leukocytes. J Clin Microbiol 1992,30(9):2246–55.
4. Wellington M, Dolan K, Krysan DJ. Live Candida albicans suppresses
production of reactive oxygen species in phagocytes. Infect Immun 2009
Jan,77(1):405–13.
5. Schuit KE. Phagocytosis and intracellular killing of pathogenic yeasts by
human monocytes and neutrophils. Infect Immun 1979,24(3):932–8.
6. Destin KG, Linden JR, Laforce-Nesbitt SS, Bliss JM. Oxidative burst and
phagocytosis of neonatal neutrophils confronting Candida albicans and
Candida parapsilosis. Early Hum Dev 2009 Aug,85(8):531–5.
7. Martin E, Bhakdi S. Quantitative analysis of opsonophagocytosis and
of killing of Candida albicans by human peripheral blood leukocytes by
using flow cytometry. J ClinMicrobiol 1991,29(0095–1137 SB–IM):2013–
23.
8. Salih HR, Husfeld L, Adam D. Simultaneous cytofluorometric
measurement of phagocytosis, burst production and killing of human
phagocytes using Candida albicans and Staphylococcus aureus as
target organisms. Eur Soc Clin Infect Dis 2000,6:251–8.
9. Vitro I, Medical D, Conformity E. Instructions PHAGOBURST  Version
04/09 page 1 of 9. :1–9.
10. Grumach AS, Ceccon ME, Rutz R, Fertig A, Kirschfink M. Complement
profile in neonates of different gestational ages. Scand J Immunol
2014,79(4):276–81.
11. Yan M, Jacobs P , Wood B, Jevremovic D, Marie CB, Nancy D, et al.
Validation of Cell-based Fluorescence Assays : Practice Guidelines
from the ICSH and ICCS – Part V – Assay Performance Criteria n e.
2013,323(May):315–23. 12. O’Hara DM, Xu Y, Liang Z, Reddy MP , Wu DY, Litwin V. Recommendations
for the validation of flow cytometric testing during drug development: II
assays. J Immunol Methods 2011 Jan,363(2):120–34.
13. Wang L, Gaigalas AK, Marti G, Abbasi F, Hoffman RA. Toward quantitative
fluorescence measurements with multicolor flow cytometry. Cytom Part A
2008 Apr,73A(4):279–88.
14. Barnett D, Granger V, Kraan J, Whitby L, Reilly JT, Papa S, et al. Reduction
of intra- and interlaboratory variation in CD34+ stem cell enumeration
using stable test material, standard protocols and targeted training. Br J
Haematol 2000 Mar,108(4):784–92.
15. Dühring S, Germerodt S, Skerka C, Zipfel PF, Dandekar T, Schuster S.
Host-pathogen interactions between the human innate immune system
and Candida albicans-understanding and modeling defense and evasion
strategies. Front Microbiol 2015,6(JUN):1–18.
16. Cheng SC, Joosten LAB, Kullberg BJ, Netea MG. Interplay between
Candida albicans and the mammalian innate host defense. Infect Immun
2012,80(4):1304–13.
17. Mayer FL, Wilson D, Hube B. Candida albicans pathogenicity
mechanisms. Virulence 2013,4(2):119–28.
18. Brown AJP , Budge S, Kaloriti D, Tillmann A, Jacobsen MD, Yin Z, et
al. Stress adaptation in a pathogenic fungus. J Exp Biol 2014,217(Pt
1):144–55.
19. Miramón P , Kasper L, Hube B. Thriving within the host: Candida spp.
interactions with phagocytic cells. Med Microbiol Immunol 2013 Jun
25,202(3):183–95.
20. Frohner IE, Bourgeois C, Yatsyk K, Majer O, Kuchler K. Candida albicans
cell surface superoxide dismutases degrade host-derived reactive
oxygen species to escape innate immune surveillance. Mol Microbiol
2009,71(1):240–52.
21. Lopez CM, Wallich R, Riesbeck K, Skerka C, Zipfel PF, Soloviev D.
Candida albicans Uses the Surface Protein Gpm1 to Attach to Human
Endothelial Cells and to Keratinocytes via the Adhesive Protein Vitronectin.
Stevenson B, editor. PLoS One 2014 Mar 13,9(3):e90796.
22. Gazendam RP , Hamme JL Van, Tool ATJ, Houdt M Van, Verkuijlen
PJJH, Herbst M, et al. Two independent killing mechanisms of Candida
albicans by human neutrophils : evidence from innate immunity defects.
2017,124(4):590–8. Șular Floredana-Laura et al. / Acta Medica Marisiensis 2017;63(2):91-96