Abstract
Background
: Propolis and honey are natural bee products with wide range of biological and medicinal properties. The study investigated antimicrobial activity of ethyl alcohol extraction of propolis collected from Saudi Arabia (EEPS) and from Egypt (EEPE), and their synergistic effect when used with honey. Single and polymicrobial cultures of antibiotic resistant human pathogens were tested.
Material and methods
;
Staphylococcus aureus
(
S. aureus
),),
Escherichia coli
(
E. coli
) and
Candida albicans (C.albicans)
were cultured in 10-100% (v/v) honey diluted in broth, or 0.08-1.0% (weight/volume) EEPS and EEPE diluted in broth. Four types of polymicrobial cultures were prepared by culturing the isolates with each other in broth (control) and broth containing various concentrations of honey or propolis. Microbial growth was assessed on solid plate media after 24 h incubation.
Results;
EEPS and EEPE inhibited antibiotic resistant
E.coli,
and
S.aureus,
and
C.albicans
in single and polymicrobial cultures
. S.aureus
became more susceptible when it was cultured with
E.coli
or
C.albicans
or when all cultured together.
C.albicans
became more susceptible when it was cultured with
S.aureus
or with
E.coli
and
S. aureus
together. The presence of ethyl alcohol or honey potentiated antimicrobial effect of propolis toward entire microbes tested in single or polymicrobial cultures. EEPS had lower MIC toward
E.coli
and
C.albicans
than EEPE. When propolis was mixed with honey, EEPS showed lower MIC than EEPE. In addition, honey showed lower MIC toward entire microbes when mixed with EEPS than when it was mixed with EEPE.
Conclusion
; 1) propolis prevents the growth of the microorganisms in single and mixed microbial cultures, and has synergistic effect when used with honey or ethyl alcohol, 2) the antimicrobial property of propolis varies with geographical origin, and 3) this study will pave the way to isolate active ingredients from honey and propolis to be further tested individually or in combination against human resistant infections.