Abstract
Oral candidiasis, the most common mycotic infection of the human oral cavity is non-life-threatening yet, if untreated, may advance as systemic infections. The ability of Candida albicans to ...adapt sessile lifestyle imparts resistance to drugs and host immunity. Consequently, due to the limited effectiveness of conventional antifungal treatment, novel therapeutic strategies are required. In the present study, synergistic interaction of phytochemicals, piperine, and cinnamaldehyde against the biofilm and hyphal of C. albicans was evaluated. Minimum inhibitory concentration (MIC) and biofilm inhibitory concentration (BIC) of piperine and cinnamaldehyde against C. albicans were analyzed through microbroth dilution assay and crystal violet staining method, respectively. Combinatorial biofilm and hyphal inhibitory effect were investigated through checkerboard assay. In vitro results were validated through gene expression analysis. BIC of piperine and cinnamaldehyde was determined to be 32 μg/ml and 64 μg/ml, respectively. Interaction between these two phytocomponents was found to be synergistic and six different synergistic antibiofilm combinations were identified. Microscopic analysis of biofilm architecture also evidenced the biofilm and surface adherence inhibitory potential of piperine and cinnamaldehyde combinations. Phenotypic switching between yeast and hyphal morphological forms was influenced by synergistic combinations. qPCR analysis corroborated the results of in vitro activities. nrg1 and trp1, the negative transcriptional regulators of filamentous growth were upregulated whereas other genes that are involved in biofilm formation, filamentous growth, adhesion, etc. were found to be downregulated. These proficient phytochemical combinations provide a new therapeutic avenue for the treatment of biofilm-associated oral candidiasis and to combat the recurrent infections due to antibiotic resistance.
Lay abstract
Resistance to antibiotics and antifungals is seemingly increasing due to biofilm-associated infections.
The present study incorporated antibiofilm therapy and a combinatorial approach to diminish the biofilm associated C. albicans infection.
is an opportunistic fungal pathogen and most prevalent species among clinical outbreaks. It causes a range of infections, including from mild mucosal infections to serious life-threatening candidemia ...and disseminated candidiasis. Multiple virulence factors account for the pathogenic nature of
, and its morphological transition from budding yeast to hyphal form and subsequent biofilm formation is regarded as the most important reason for the severity of
infections. To address the demanding need for novel antifungals, we investigated the anti-biofilm activities of various methylindoles against
using a crystal violet assay, and the metabolic activity was assessed by using a 2,3-bis (2-methoxy-4-nitro-5-sulfo-phenyl)-2H-tetrazolium-5-carboxanilide reduction assay. Changes in biofilm morphologies and thicknesses were determined by confocal laser scanning microscopy and scanning electron microscopy, respectively. Of the 21 methylindoles tested, 1-methylindole-2-carboxylic acid (1MI2CA) at 0.1 mM (17.5 μg ml
) and 5-methylindole-2-carboxylic acid (5MI2CA) at 0.1 mM effectively inhibited biofilm formation by
DAY185 and ATCC10231 strains. Moreover, 1MI2CA and 5MI2CA both effectively inhibited hyphal formation, and thus, improved
infected nematode survival without inducing acute toxic effects. Furthermore, our
molecular modeling findings were in-line with
observations. This study provides information useful for the development of novel strategies targeting candidiasis and biofilm-related infections.
•UPLC-MS/MS method developed to quantify obliquumol concentration in P. obliquum acetone extracts.•Ptaeroxylinol had MIC values as low as 8 µg/mL and 16 µg/mL against C. albicans ATCC 10,231 and ...cryptococcus neoformans respectively.•Ptaeroxylinol had some antimycobacterial activity with MIC value of 62.5 µg/mL against both M. bovis BCG and M. fortuitum.•Ptaeroxylinol had low toxicity against both vero and human liver (C3A) cells with IC50 = 85.7 and 126.51 µg/mL respectively.
Quantification of compounds in plant extracts is rarely conducted to determine variation in concentrations of bioactive constituents. The aim of the study was to develop a method using ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) to identify and quantify obliquumol (12-O-acetylptaeroxylinol) in Ptaeroxylon obliquum leaves collected from different localities in South Africa. Additionally, biological activity of a semi-synthesized derivative, ptaeroxylinol was investigated. Column chromatography was used to isolate obliquumol from P. obliquum leaves, and thereafter it was saponified to ptaeroxylinol. Ultra-performance liquid chromatography coupled to quadrupole time of flight mass spectrometry (UPLC-qTof-MS) was carried out on the different P. obliquum extracts to quantify obliquumol. A serial microdilution method was used to determine the minimum inhibitory concentration (MIC) against non-pathogenic mycobacteria and fungi. The cytotoxicity was determined using Vero monkey kidney and human liver (C3A) cells. A method was developed to isolate large quantities of obliquumol (0.14%) from dried P. obliquum leaves. The different P. obliquum acetone extracts had variable obliquumol concentrations between 0.1–38.5 µg/mg. Ptaeroxylinol had an MIC as low as 8 µg/mL and 16 µg/mL against Candida albicans ATCC 10,231 and Cryptococcus neoformans, respectively. With an IC50 of 85.7 μg/mL for Vero cells and 126.51 μg/mL for C3A cells, respectively, ptaeroxylinol had low cytotoxicity to the cells tested. A UPLC-MS/MS method was developed to quantify obliquumol content in the P. obliquum acetone extracts. Ptaeroxylinol had good activity against C. albicans (MIC = 8 µg/mL) and it appears that the cleavage of the acetoxy to alcohol group played a role in the antimicrobial activity.
A major driving factor for antimicrobial resistance which leads to treatment failure for microbial infections ascribed to C. albicans are the formation of biofilms. 3D printing is a rapidly evolving ...innovation which could revolutionize drug delivery based on its unprecedented opportunity for targeted and improved delivery. Herein, we designed and 3D printed microbots via two photon-polymerisation. Subsequently, characterisation was performed and the activity of microbots independently and in combination with allicin against C. albicans biofilms were investigated. The microbots independently did not affect C. albicans biofilm formation and adhesion nor was there any significant synergistic interaction between microbots and allicin combination. However, this study has pioneered the utilisation of microbots for microbiological applications such as in combination with an antimicrobial to target biofilms. These prototype microbots will act as a guide for the next generation of microbots which will be functionalised to disrupt biofilms magnetically, enhancing allicin delivery and activity.
A variety of Candida spp. as the most common fungi in the human body can normally be found in the vagina competing with other microbotes. Their presence is influenced by a variety of conditions in ...the vaginal environment. The proliferation of Candida spp. in the vagina under specific conditions can result in a fungal disease known as vaginal candidiasis. More than 17 species of Candida out of 200 members of this genus are capable of causing diseases within the human body. Estrogen, along with other steroidal hormones, has been shown to have direct multifunctional effects on various pathogenic microorganisms by numerous activities. Its production as well as other factors such as disturbance of microbial balance and immune activity may alter the vaginal physical environment and promote the development of vaginal fungal infection. The vaginal functions can be affected by the level of circulation of estrogens in the blood according to the stage of the menstrual cycle in women. It also has many other functional actions on the vaginal structure. Estrogen and several other factors play an important role in determining the vaginal content of Candida species. Its effect could be a direct action on the cells of Candida or through an indirect effect on the immunity defenses of the vagina.
Cutaneous candidiasis is one of the most prevalent mycotic infections caused by
Candida
species. The severity of infection mounts faster when the species shows antifungal resistance. In the current ...retrospective study, we aimed to analyze the occurrence, causes of cutaneous candidiasis, and antifungal susceptibility pattern of
Candida
isolates from Skin and Venereal Diseases Prevention and Control Hospital of Shantou, located in eastern Guangdong, China. The laboratory data of all patients (
n
= 3,113) suffering from various skin and venereal infections during January 2012 to December 2021 was analyzed through Excel and GraphPad prism. Our analysis indicate that cutaneous candidiasis was 22.29% (
n
= 694), of which 78.53% (
n
= 554) of patients were males and 21.47% (
n
= 149) of patients were females. The median age of patients with cutaneous candidiasis was 38-year interquartile range (30–48). Most cases occurred in the adult age group (19–50 years). Regarding the species type, the
Candida albicans
were prominently detected (
n
= 664, 95.68%), while non-
C. albicans
were found only in 30 (4.32%) patients, which were
C. glabrata
(
n
= 18),
C. krusei
(
n
= 8),
C. tropicalis
(
n
= 3), and
C. parapsilosis
(
n
= 1). The
C. albicans
susceptibility rate for terbinafine, miconazole, voriconazole, itraconazole, fluconazole, ketoconazole, nystatin, 5-flucytosine and amphotericin B were 10.83, 29.32, 59.39, 78.53, 85.28, 87.75, 99.59, 99.41, and 100%, respectively. Finally, all
C. glabrata
isolates were found susceptible to all tested azole drugs with exception to miconazole against which 8.33% of isolates showed resistance. The findings of this study will help healthcare officials to establish better antifungal stewardship in the region.
In microbial biofilms, microorganisms utilize secreted signaling chemical molecules to coordinate their collective behavior. Farnesol is a quorum sensing molecule secreted by the fungal species
and ...shown to play a central physiological role during fungal biofilm growth. Our pervious
and
studies characterized an intricate interaction between
and the bacterial pathogen
, as these species coexist in biofilm. In this study, we aimed to investigate the impact of farnesol on
survival, biofilm formation, and response to antimicrobials. The results demonstrated that in the presence of exogenously supplemented farnesol or farnesol secreted by
in biofilm,
exhibited significantly enhanced tolerance to antimicrobials. By using gene expression studies,
mutant strains, and chemical inhibitors, the mechanism for the enhanced tolerance was attributed to upregulation of drug efflux pumps. Importantly, we showed that sequential exposure of
to farnesol generated a phenotype of high resistance to antimicrobials. Based on the presence of intracellular reactive oxygen species upon farnesol exposure, we hypothesize that antimicrobial tolerance in
may be mediated by farnesol-induced oxidative stress triggering the upregulation of efflux pumps, as part of a general stress response system. Hence, in mixed biofilms,
may influence the pathogenicity of
through acquisition of a drug-tolerant phenotype, with important therapeutic implications. Understanding interspecies signaling in polymicrobial biofilms and the specific drug resistance responses to secreted molecules may lead to the identification of novel targets for drug development.
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