الفهرس 
Aim of the studyOnly 14 pages are availabe for public view
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Abstract
Biofilms, are complex biological communities which are difficult to treat
by conventional antibiotic therapy, contributing to >80% of human infections.
In this study, the antibiofilm activity of various substances, including five
essential oils (EOs), cinnamon (Cinnamomum cassia), marjoram (Majorana
hortensis), tea tree (Melaleuca alternifolia ), clove (Syzygium aromaticum), and
mint (Menth peperita) were examined. It also included the effect of honey bee,
antibiotics, and nanoparticles(NPs) (chitosan, silver, and selenium
nanoparticles) against the biofilm of the Gram-negative pathogenic bacterium
Pseudomonas aeuroginosa and the polymorphic pathogen Candida albicans
which are major human pathogens posessing a high risk to humans due to their
biofilm development ability. Antibiofilm activities of tested compounds were
evaluated by crystal violet staining assay, and detected by scanning, fluorescent,
and lighet microscopy.
Out of twelve clinical specimens, eleven clinical isolates of Candida were
isolated on sabouraud dextrose agar (SDA) and potato dextrose agar (PDA). All
isolates were screened for their ability to form biofilms and two isolates which
were strong biofilm producers were chosen for biofilm study.
The two isolates of Candida were subsequently identified by the
biochemical test VITEK and by rRNA sequencing. Results revealed that C4
isolate was Candida albicans and C3 isolate was Candida auris.
Antibiofilm activity showed a strong effect of these compounds against
tested bacterial and fungal biofilms. Interestingly, EOs and NPs demonstrated
the highest activity against the investigated microorganisms’ biofilms. EOs
demonstrated antibiofilm activity ranged from 20.5 to 86.4% against of P.
aeuroginosa (ATCC 9027 and ATCC P14) and from 19.5 to 80.7% against C.
albicans reference strains (ATCG25922 and ATCC 10231) and Candida
clinical isolates (C3 and C4). Cinnamon oil showed the strongest antibiofilm
activity with biofilm reduction ranged from 32.3 to 86.4% against P.
aeuroginosa strains and from 44.8 to 80.7% against Candida strains. On the
other hand, honey bee showed antibiofilm activity ranged from 6.3 to 57.6%
against Candida strains and from 40.9 to 70.3% against Pseudomonas
aeuroginosa.
Antibacterials (Chloramphenicol and Vibramycin) showed antibiofilm
activity ranged from 20 to 68.5% against P. aeuroginosa strains, while
antifungals (Fluconazole and Itraconazole) showed antibiofilm activity ranged
from 2.8 to 70.2% against tested Candida. NPs showed biofilm reduction
ranged from 9.4 to 87.5% against P. aeuroginosa strains and from 27.2 to 76.8
% against Candida strains. Chitosan nanoparticles (ChNPs), and silver
nanoparticles (AgNPs) exhibited the strongest antibiofilm activity. Chitosan
nanoparticles (ChNPs) showed biofilm reduction ranged from 66.5 to 87.5%
against P. aeuroginosa strains and from 51.8 to 76.8% against Candida strains,
while silver nanoparticles (AgNPs) showed biofilm reduction ranged from 67.9
to 84.3% against tested Pseudomonas aeuroginosa strains and from 36.4 to 73%
against tested Candida strains.
In the present study, cinnamon oil, chitosan nanoparticles (ChNPs), and
silver nanoparticles (AgNPs) showed the strongest antibiofilm activities against
tested P. aeuroginosa and Candida strains, suggesting that they could be viable
alternatives to antibiotics.