Reference Strains Of Candida Albicans Research Articles

Obtaining and research of callus biomass of some plants of the family Ranunсulaсаe

Introduction: Research among the Ukrainian (Carpatian) flora’s representatives is important for searching for new active compounds.Objective: The study aims to determine the potential of callus biomass of Delphinium elatum, Anemone nemorosa, and Pulsatilla alba to become an analog of medicinal plant raw material for the use in the pharmaceutical industry, to investigate the composition, antioxidant activity and antimicrobial activity of extracts of the callus biomass of the above-mentioned plants.Methods: The individual members of the family Ranunculaceae (Delphinium elatum L., Anemone nemorosa L., Pulsatilla alba Rchb.) were introduced into in vitro culture, and their callus induction was studied using the Folin-Ciocalteu spectrophotometric method, colorimetric analysis, antioxidant, and antimicrobial activity methods.Results: The maximum content of flavonoids and phenolic compounds was observed in 40% hydro-ethanolic extracts of callus biomass and plant raw materials of D. elatum. 90.0% and 70.0% D. elatum extracts showed significant activity against Gram-positive microorganisms. 90.0/70.0/40.0% extracts showed significant activity against Bacillus licheniformis. 70.0 % extract showed significant antifungal activity against clinical and reference strains of Candida albicans. Conclusion: Summarizing experimental results, it was proved that the callus biomass of D. elatum, A. nemorosa, and P. alba have potential as analogs of medicinal plant raw materials, both for the content of biologically active substances and biological activities.

In Vitro Antifungal Activity of Three Synthetic Peptides against Candida auris and Other Candida Species of Medical Importance.

Candidiasis is an opportunistic infection affecting immunosuppressed and hospitalized patients, with mortality rates approaching 40% in Colombia. The growing pharmacological resistance of Candida species and the emergence of multidrug-resistant Candida auris are major public health problems. Therefore, different antimicrobial peptides (AMPs) are being investigated as therapeutic alternatives to control candidiasis effectively and safely. This work aimed to evaluate the in vitro antifungal activity of three synthetic AMPs, PNR20, PNR20-1, and 35409, against ATCC reference strains of Candida albicans, Candida glabrata, Candida parapsilosis, Candida krusei, and Candida tropicalis, and clinical isolates of C. auris. Antifungal susceptibility testing, determined by broth microdilution, showed that the AMPs have antifungal activity against planktonic cells of all Candida species evaluated. In C. auris and C. albicans, the peptides had an effect on biofilm formation and cell viability, as determined by the XTT assay and flow cytometry, respectively. Also, morphological alterations in the membrane and at the intracellular level of these species were induced by the peptides, as observed by transmission electron microscopy. In vitro, the AMPs had no cytotoxicity against L929 murine fibroblasts. Our results showed that the evaluated AMPs are potential therapeutic alternatives against the most important Candida species in Colombia and the world.

Variability of pathogenicity factors representative of the human microbiome under the influence of γ-Fe2O3 nanoparticles

Biomedical applications of nanoparticles require deep understanding of their interaction with normal human microflora. Previously, the toxic and mutagenic properties of iron oxide nanoparticles as well as their effect on the growth and morphology of the microflora were extensively investigated. However, the studies related to the variability of microbial pathogenicity factors induced by iron oxide nanoparticles are very limited. Meanwhile, this characteristic of microbes is genetically determined and is important for their survival and distribution in the human body. Therefore, pathogenicity factors are significant indicators of the experimental studies. In this work, the effect of the presence of Fe2O3 nanoparticles obtained by laser target evaporation (LTE) on selected enzymes that demonstrate invasion and aggression factors was evaluated for three reference strains of Candida albicans, Staphylococcus aureus, and Escherichia coli. It was found that the presence of LTE Fe2O3 nanoparticles supplied in the form of water-based suspensions does not induce changes of the above-mentioned parameters.

Comparative assessment of fungicidal activity of widespread wild-growing and endemic species of the Allium genus growing in Tajikistan

Aim. To conduct a comparative assessment of the fungicidal activity of widespread and endemic species of the genus Allium growing in Tajikistan.Material and methods. The initial ethanol extracts were obtained from fresh plants of 15 onion species from different climatic and geographical regions of the Republic of Tajikistan. The antifungal activity of species of the genus Allium was studied against the yeast-like fungi Candida albicans using the disk diffusion method.Results: The highest fungicidal effect on the reference strain of Candida albicans was demonstrated by alcoholic extracts of the widespread wild species A. elatum Regel, A. oschaninii O. Fedtsch, A. obliguum L, and endemic species A. shugnanicum Vved. Low antifungal activity was found in extracts of 4 widespread wild-growing plant species - A. altaicum Pall, A. suworowii Regel, A. carolinianum DC, A.longicuspis L.Conclusions. The antifungal activity of 13 species of widespread wild-growing and 2 endemic species (A.shugnanicum Vved and A. pamiricum Wendelbo) was studied for the first time. A. elatum Regel, A. oschaninii O. Fedtsch, A. obliguum L, and endemic species A. shugnanicum Vved had a maximal inhibitory effect on the yeast fungus. The extracts obtained from the bulbs and seeds of the studied plants are characterized by the highest antifungal activity.

Antimicrobial Activity of Phytic Acid: An Emerging Agent in Endodontics.

BackgroundPhytic acid (IP6) is a promising and emerging agent, and because of its unique structure and distinctive properties, it lends itself to several applications in dentistry. Recently, IP6 was proposed as a potential chelating agent in endodontics. However, there is limited knowledge regarding its antimicrobial and antibiofilm effectiveness. The aims of this study, were therefore to evaluate the antimicrobial and antibiofilm activities of IP6 against a range of microbial species and compare these with ethylenediaminetetraacetic acid (EDTA) and sodium hypochlorite (NaOCl). The contact time required for IP6 to exert its bactericidal effect on Enterococcus faecalis was also determined.MethodsThe inhibitory and biocidal activities of IP6, EDTA and NaOCl were assessed using a broth microdilution assay against 11 clinical and reference strains of bacteria and a reference strain of Candida albicans. The contact time required for various IP6 concentrations to eliminate planktonic cultures of E. faecalis was determined using a membrane filtration method according to BS-EN-1040:2005. IP6 bactericidal activity was also evaluated using fluorescent microscopy, and the antibiofilm activity of the test agents was also determined.ResultsIP6 was biocidal against all tested microorganisms. At concentrations of 0.5%, 1% and 2%, IP6 required 5 min to exert a bactericidal effect on E. faecalis, while 5% IP6 was bactericidal after 30 s. IP6 also eradicated biofilms of the tested microorganisms. In conclusion, IP6 had notable antimicrobial effects on planktonic and biofilm cultures and exhibited rapid bactericidal effects on E. faecalis. This research highlighted, for the first time the antimicrobial and antibiofilm properties of IP6, which could be exploited, not only in dental applications, but also other fields where novel strategies to counter antimicrobial resistance are required.

Роль здатності букальних епітеліоцитів до адгезії Candida albicans та впливу на неї регуляторних цитокінів у перебігу інфекційного процесу у хворих на кандидоз слизової оболонки верхнього відділу травного тракту

Роль букальних епітеліоцитів у розвитку кандидозу та їх взаємозв’язок із особливостями цитокінового балансу у хворих на кандидоз верхнього відділу травного тракту продовжує вивчатися й сьогодні. Мета дослідження. Вивчити рівні цитокінів інтерлейкіну‑1β (IL‑1β), IL‑4, IL‑6, IL‑8 та фактору некрозу пухлини альфа (ФНП-α) у хворих гастроентерологічного профілю з кандидозом верхнього відділу травного тракту і порівняти отримані дані з показниками здатності букальних епітеліоцитів до адгезії референтного штаму Candida albicans залежно від глибини ураження слизової оболонки. Матеріали та методи. Дослідження проведено на букальних епітеліоцитах від 66 пацієнтів, які за результатами мікробіологічного дослідження зскрібка з язика та біоптатів стравоходу і шлунка розподілені на три групи. Перша група (1) — 31 пацієнт із орофарингеальним кандидозом і поверхневим ростом грибів у біоптатах, із них 1А підгрупа — 8 осіб із поверхневим ростом, друга група (2) — 25 хворих із інвазією грибів у слизову оболонку, третя група (3) — 10 осіб без орофарингеального кандидозу та без росту грибів. Результати. Показано, що середнє значення індексу адгезії букальних епітеліоцитів було у 1,3 і 1,6 раза вищим у 2 групі порівняно з 1 групою та 1А підгрупою (р < 0,05 і р < 0,05 відповідно). В обстежених пацієнтів значно знижений рівень IL‑4 (р < 0,001), на фоні якого у 1 і 2 групах спостерігається істотне підвищення рівня IL‑8 (р < 0,01 і р < 0,001), та у 1 групі — IL‑1β (р < 0,05). Пацієнтів 1А підгрупи відрізняє значно вищий рівень IL‑6 та ФНП-α порівняно із 2 групою (р < 0,05 і р < 0,05 відповідно). Підвищення здатності букальних епітеліоцитів до адгезії Candida albicans знаходиться у прямому кореляційному зв’язку з рівнем IL‑8 та у зворотному — з рівнем IL‑4, а залежно від глибини ураження слизової оболонки має різноспрямований зв’язок із IL‑6 та ФНП-α. Висновки. Характер перебігу інфекційного процесу залежить від здатності букальних епітеліоцитів хворих до адгезії Candida albicans, що пов’язана з особливостями у цитокіновому статусі пацієнтів.

Antifungal Activity and DNA Topoisomerase Inhibition of Hydrolysable Tannins from Punica granatum L.

Punica granatum L. (pomegranate) fruit is known to be an important source of bioactive phenolic compounds belonging to hydrolysable tannins. Pomegranate extracts have shown antifungal activity, but the compounds responsible for this activity and their mechanism/s of action have not been completely elucidated up to now. The aim of the present study was the investigation of the inhibition ability of a selection of pomegranate phenolic compounds (i.e., punicalagin, punicalin, ellagic acid, gallic acid) on both plant and human fungal pathogens. In addition, the biological target of punicalagin was identified here for the first time. The antifungal activity of pomegranate phenolics was evaluated by means of Agar Disk Diffusion Assay and minimum inhibitory concentration (MIC) evaluation. A chemoinformatic analysis predicted for the first time topoisomerases I and II as potential biological targets of punicalagin, and this prediction was confirmed by in vitro inhibition assays. Concerning phytopathogens, all the tested compounds were effective, often similarly to the fungicide imazalil at the label dose. Particularly, punicalagin showed the lowest MIC for Alternaria alternata and Botrytis cinerea, whereas punicalin was the most active compound in terms of growth control extent. As for human pathogens, punicalagin was the most active compound among the tested ones against Candida albicans reference strains, as well as against the clinically isolates. UHPLC coupled with HRMS indicated that C. albicans, similarly to the phytopathogen Coniella granati, is able to hydrolyze both punicalagin and punicalin as a response to the fungal attack. Punicalagin showed a strong inhibitory activity, with IC50 values of 9.0 and 4.6 µM against C. albicans topoisomerases I and II, respectively. Altogether, the results provide evidence that punicalagin is a valuable candidate to be further exploited as an antifungal agent in particular against human fungal infections.

Development of new dermatological formulations for the treatment of cutaneous candidiasis

The inhibitory activity of the essential oils (EO) of mint and thyme on Candida albicans are well known, however, their valorization in a dosage form for the management of cutaneous candidiasis has been little explored. This study aimed to formulate innovative and cost-effective dermatological topicals based on mint and thyme essential oils for the treatment of cutaneous candidiasis. Thyme essential oil was obtained commercially, while that of mint was obtained by hydrodistillation. In order to determine their antifungal activity, both essentials oils were tested alone and in combination against a reference strain of Candida albicans (strain MHMR) and clinical strains of Candida albicans and Candida tropicalis. Three creams were formulated using natural (shea butter, palm oil) and chemical (cetomacrogol) excipients. The efficacies of these creams were assessed in vivo using Wistar rats infected with Candida albicans MHMR. The in vitro antimicrobial study showed that C. albicans MHMR was more sensitive to thyme essential oil with a MIC of 310 μgmL−1, which was higher than the reference fluconazole used for the in vitro study (32 μgmL−1). The antimicrobial synergy study of both essential oils using checkerboard test demonstrated an additive effect of mint and thyme essential oils on C. albicans MHMR. GC/FID and GC/MS analyses led to the identification of thymol and menthol respectively as the main components of thyme and mint essential oils. A shea butter cream base and a shea butter and palm oil cream both containing 5% of EO (mint and thyme) exhibited the best in vivo antimicrobial activities, inducing optimal wound healing in infected rats compared with ketoconazole commercial cream used for the in vivo study. These results provide a solid basis at least in part, for the use of essential oil in creams formulated with natural excipients for the management of cutaneous candidiasis.

Chemical composition and in vitro activity of Origanum vulgare L., Satureja hortensis L., Thymus serpyllum L. and Thymus vulgaris L. essential oils towards oral isolates of Candida albicans and Candida glabrata

AbstractThe purpose of this research was to investigate the chemical composition of essential oils (EOs) from:Origanum vulgareL.,Satureja hortensisL.,Thymus serpyllumL. andThymus vulgarisL. (Lamiaceae) cultivated in Poland, and to study their antifungal activity towards clinical isolates of oralCandidaspp. The hydrodistilled essential oils were analyzed using the GC-MS method. The antifungal activity was evaluatedin vitroagainst oral isolates and reference strains ofCandida albicansandC. glabrata, using the broth microdilution method according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) and Clinical and Laboratory Standards Institute (CLSI) guidelines, allowing for estimation of minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC). GC-MS analysis revealed that carvacrol was the main EO compound in oregano and summer savory, while thymol and linalool were the major ingredients of thyme and wild thyme oils, respectively. The EOs possessed fungicidal activity againstC. albicansandC. glabrata, including oral isolates, with MIC = 125 – 2000 mg/L, MFC = 250 – 4000 mg/L and MFC/MIC = 1 – 4, depending on the yeast and plant species. The most active was thyme oil – with MIC = 125 – 500 mg/L, MFC = 250 – 500 mg/L and MFC/MIC = 1 – 2.

Antifungal Activity of the Human Uterine Cervical Stem Cells Conditioned Medium (hUCESC-CM) Against Candida albicans and Other Medically Relevant Species of Candida.

Background: Candidiasis is a major cause of human morbidity and mortality. Human uterine cervical stem cells conditioned medium (hUCESC-CM) is obtained from stromal stem cells of the cervical transformation zone, which are in permanent contact with a wide array of potential vaginal pathogens. In previous reports we have found that hUCESC-CM has antitumor and antibacterial potential. Since Candida is the most prevalent yeast in the human vagina, it seems plausible that hUCESC-CM might also show activity against it.Methods: In a preliminary step, to evaluate if hUCESC-CM showed any activity at all on Candida growth, in vitro activities of hUCESC-CM against fluconazole-susceptible reference strains of Candida albicans, Candida glabrata, Candida krusei, and Candida parapsilosis were studied with a microdilution method on RPMI 1640, using the BioScreen C microbiological incubator. Each measurement was repeated five times. The same methodology was used subsequently on fluconazole-susceptible and fluconazole-resistant Candida isolates from blood and vagina of those species corresponding to the reference strains of Candida against which activity had been detected in the previous study. Moreover, two fluconazole-resistant clinical isolates of Candida auris from blood and urine were also included.Findings: In vitro inhibitory activity of hUCESC-CM ranged from 57.5 to 96.6% growth-reduction against fluconazole-susceptible reference strains of Candida albicans, Candida glabrata, and Candida parapsilosis. hUCESC-CM also reduced the growth of all fluconazole-susceptible tested vaginal isolates by more than 50%. For fluconazole-resistant isolates, growth-reduction was higher than 67% for Candida albicans, regardless of its origin (vagina or blood). The isolate of Candida auris from urine with a MIC > 128 μ/ml for fluconazole was also significantly inhibited. However, hUCESC-CM was almost inactive against any of the fluconazole-resistant blood isolates of Candida glabrata, Candida parapsilosis, and Candida auris tested.Interpretation: This is the first report about the growth-inhibiting properties of conditioned medium from human stromal stem cells against different species of Candida. Antifungal activity of stromal stem cells depends on their site of origin, being most effective against Candida species most prevalent at that particular location. If confirmed in further studies, these findings might result in a completely new therapeutic approach against superficial and invasive candidiasis.

Synthesis, lipophilicity determination, DFT calculation, antifungal and DPPH radical scavenging activities of tetrahydrothiophen-3-one based thiazoles

Synthesis and investigation of antifungal activity of ten novel thiazoles derived from tetrahydrothiophen-3-one are presented. Among the derivatives, (E/Z)-2-(2-(dihydrothiophen-3(2H)-ylidene)hydrazinyl)thiazoles 3a-3d and 3h had very strong activity against reference strains of Candida albicans and Candida krusei with MIC = 0.24–3.91 μg/ml. Their lipophilicity was determined using reversed-phase high performance liquid chromatography and correlated with antifungal activity. Additionally, their DPPH radical scavenging activities was evaluated by spectrophotometric method. According to our results, compounds 3b, 3h and 3j have very strong antioxidant activities with IC50 values from 3.0 to 9.5 μg/ml. The antioxidant activity of these compounds is 5–17 times higher than butylated hydroxytoluene. The RP HPLC analysis revealed that the products are obtained as E/Z mixture in approximately 60:40 ratio, in good agreement with DFT predictions.

Short communication: Cold atmospheric plasma inactivation of Prototheca zopfii isolated from bovine milk

Mastitis is a serious bovine diseases that can be caused by Prototheca zopfii, yeast-like algae belonging to the family Chlorellaceae. The substantial economic losses and health damage associated with bovine mastitis emphasize the need to develop effective strategies aimed at control of the infection. Unfortunately, P. zopfii is highly resistant to most common antibacterial and antifungal agents, as well as to heat treatment. We report here the first attempt to use cold atmospheric plasma to inactivate this pathogen. We studied 20 strains of P. zopfii isolated from milk samples taken from cows with clinical or subclinical mastitis. The studies confirmed the high level of resistance of P. zopfii to typical antifungal agents, such as voriconazole, fluconazole, amphotericin B, caspofungin, anidulafungin, and micafungin. In contrast, each of the strains revealed high susceptibility to cold atmospheric plasma, >2-fold higher compared with a reference strain of Candida albicans. The obtained results are promising and open up a new approach in the fight against P. zopfii.

Chemical composition and antifungal activity of essential oil of Hyssopus officinalis L. from Bulgaria against clinical isolates of Candida species

The chemical composition of hyssop oil from Bulgaria was determined by gas chromatography with flame ionization detection and gas chromatography–mass spectrometry on two different chromatographic columns. The quantity of identified compounds was shown correspond to 97.2% and 98% of the total oil content. Among the detected compounds, cis-pinocamphone (48.98%–50.77%), β-pinene (13.38%–13.54%), trans-pinocamphone (5.78%–5.94%) and β-phellandrene (4.44%–5.17%) were the major compounds. Hyssop oil demonstrated antifungal activity against 52 clinical isolates and reference strains of Candida albicans, Candida glabrata, Candida tropicalis, Candida parapsilosis and Candida krusei. The essential oil characterized with stronger antifungal activity in comparison with pure cis- and trans-pinocamphone, α- and β-pinene and β-phellandrene. Essential oil of Hyssopus officinalis L. from Bulgaria inhibited both fluconazol-sensitive and fluconazol-resistant strains.

Chemical Composition Analysis and Antimicrobial Screening of the Essential Oil of a Rare Plant from Jordan: Ducrosia flabellifolia

The composition of the essential oil isolated from the fresh and dry leaves of Ducrosia flabellifolia Boiss. (Apiaceae) was determined by gas chromatography and gas chromatography–mass spectrometry using hydrodistillation and solid phase microextraction (SPME). The hydrodistilled oil of the fresh leaves yielded 38 components, accounting for 98.67% of the total oil content, while thirty components were detected from the fresh leaves by solid phase microextraction (94.85%). Fifty-one and 36 components were identified in the hydrodistilled and SPME oils of the dried leaves amounting to 98.78% and 94.52%, respectively. A total of 25 components accounting for 97.24% of the total composition were characterized in the SPME oil of the fresh flowers. Aliphatic compounds predominated in the volatile fractions of the leaves and flowers of both methods with n-decanol, n-decanal, and dodecanal as the main constituents. The α- and ß-pinene were the major monoterpenoids in the oils. The hydrodistilled oil was screened for its antimicrobial and antioxidant activities. The minimal inhibitory concentration of the volatile oil was determined using a microdilution method in 96 well plates against a panel of gram (+), gram (−) bacteria, and fungi. Overnight cultures of reference strains of Candida albicans, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus were used as test microorganisms. The oil exhibited the best activity against C. albicans (MIC 234 µg/mL) and S. aureus (MIC 234 µg/mL) whereas weak activity was detected against E. coli and P. aeruginosa. No antioxidant activity could be detected.

Effect of different pre-irradiation times on curcumin-mediated photodynamic therapy against planktonic cultures and biofilms of Candida spp

ObjectivesThe aim of this study was to evaluate the effects of pre-irradiation time (PIT) on curcumin (Cur)-mediated photodynamic therapy (PDT) against planktonic and biofilm cultures of reference strains of Candida albicans, Candida glabrata and Candida dubliniensis. Materials and methodsSuspensions and biofilms of Candida species were maintained in contact with different concentrations of Cur for time intervals of 1, 5, 10 and 20min before irradiation and LED (light emitting diode) activation. Additional samples were treated only with Cur, without illumination, or only with light, without Cur. Control samples received neither light nor Cur. After PDT, suspensions were plated on Sabouraud Dextrose Agar, while biofilm results were obtained using the XTT-salt reduction method. Confocal Laser Scanning Microscopy (CLSM) observations were performed to supply a better understanding of Cur penetration through the biofilms after 5 and 20min of contact with the cultures. ResultsDifferent PITs showed no statistical differences in Cur-mediated PDT of Candida spp. cell suspensions. There was complete inactivation of the three Candida species with the association of 20.0μM Cur after 5, 10 and 20min of PIT. Biofilm cultures showed significant reduction in cell viability after PDT. In general, the three Candida species evaluated in this study suffered higher reductions in cell viability with the association of 40.0μM Cur and 20min of PIT. Additionally, CLSM observations showed different intensities of fluorescence emissions after 5 and 20min of incubation. ConclusionPhotoinactivation of planktonic cultures was not PIT-dependent. PIT-dependence of the biofilm cultures differed among the species evaluated. Also, CLSM observations confirmed the need of higher time intervals for the Cur to penetrate biofilm structures.

Enhancement of Antimycotic Activity of Amphotericin B by Targeting the Oxidative Stress Response of Candida and Cryptococcus with Natural Dihydroxybenzaldehydes

In addition to the fungal cellular membrane, the cellular antioxidant system can also be a viable target in the antifungal action of amphotericin B (AMB). Co-application of certain redox-potent natural compounds with AMB actually increases efficacy of the drug through chemosensitization. Some redox-potent chemosensitizers and AMB perturb common cellular targets, resulting in synergistic inhibition of fungal growth. Chemosensitizing activities of four redox-potent benzaldehydes were tested against clinical and reference strains of Candida albicans, C. krusei, C. tropicalis, and Cryptococcus neoformans in combination with AMB, based on assays outlined by the European Committee on Antimicrobial Susceptibility Testing. Two dihydroxybenzaldehydes (DHBAs), i.e., 2,3-DHBA and 2,5-DHBA, significantly enhanced activity of AMB against most strains, as measured by lower minimum inhibitory concentrations and/or minimum fungicidal concentrations (MFCs). A non-hydroxylated benzaldehyde, trans-cinnamaldehyde, showed chemosensitizing activity through lower MFCs, only. Contrastingly, a methoxylated benzaldehyde (3,5-dimethoxybenzaldehyde) had no chemosensitizing activity, as all strains were hypertolerant to this compound. Bioassays using deletion mutants of the model yeast, Saccharomyces cerevisiae, indicated DHBAs exerted their chemosensitizing activity by targeting mitochondrial superoxide dismutase. This targeting, in turn, disrupted the ability of the yeast strains to respond to AMB-induced oxidative stress. These in vitro results indicate that certain DHBAs are potent chemosensitizing agents to AMB through co-disruption of the oxidative stress response capacity of yeasts. Such redox-potent compounds show promise for enhancing AMB-based antifungal therapy for candidiasis and cryptococcosis.

Human oral keratinocyte E-cadherin degradation byCandida albicansandCandida glabrata

E-cadherin (E-Cad) is a 120-kDa adhesive protein found in adherens junctions of the digestive tract epithelium. We tested the ability of two Candida strains to degrade human E-Cad in the Candida virulence factor perspective. We set out to study oral mucosal E-Cad degradation by clinical and reference strains of Candida albicans and Candida glabrata. We also included hyphal and secreted aspartic proteinase (Sap) mutants of C. albicans to test the effect of yeast/hyphal transition on the ability to degrade E-Cad. The tests were performed at pH 4 and pH 6 to determine the effect of local tissue acidity on the activation of Saps. The C. albicans strains used were: CCUG 32723; clinical strain SC5314 which is known to be strongly invasive; hyphal mutants of SC5314: HLC52 (efg1/efg1), HLC54 (cph1/cph1 efg1/efg1) and JKC19 (cph1/cph1); clinical strain B1134; Sap 1-3 and Sap 4-6 mutants of SC5314. The C. glabrata strains used were ATCC 90030, and the clinical strains 5WT and G212. The sonicated yeast cells of C. albicans JKC19 and SC5314, both in hyphal form, degraded E-Cad at pH 4. The 10x concentrated growth media of the strains HLC-52, HLC-54, 32723 and B1134; all in yeast form, caused degradation at pH 4, HLC-52 and HLC-54 also at pH 6. The C. glabrata strains did not degrade E-Cad. pH is a strain dependent triggering factor in activating yeast or hyphal form related Candida Saps in degrading epithelial cell associated E-Cads.

Typing of Genetic Markers Involved in Stress Response by Fluorescent cDNA-Amplified Fragment Length Polymorphism Technique

Identification of genetic markers involved in stress response to physical factors or chemical substances in organisms is a challenging task. Typing of upregulated gene expression due to selective antibacterial pressure is a promising approach in the search of molecular mechanisms responsible for development of resistance. cDNA-Fluorescent Amplified Fragment Length Polymorphism (cDNA-FAFLP) strategy was developed and applied in the search of antimycotic drug resistance marker(s) in medically important fungi as an alternative method to microarray analysis. We compared differential gene expression of two sensitive Candida albicans reference strains (ATCC 10231 and ATCC 60133) and two of their paired resistant to fluconazole and itraconazole mutants. Resistant mutants Candida albicans FLC-R, resistant to fluconazole (MIC > 128 microg/ml) and Candida albicans ICZ-R, resistant to itraconazole (MIC > 4 microg/ml) were obtained in subcultures with gradual increase of the antifungal in the culture medium. cDNA-AFLP profile in both itraconazole resistant mutants showed specific spectrophotometric peaks with 5-6-fold RNA overexpression product of 500 bp length compared to the sensitive strains. Fluconazole mutants do not reveal RNA level changes under tested by us typing conditions. These results indicate that the cDNA-FAFLP strategy is a relatively rapid, simple, and reliable method for simultaneous typing of both constitutive and induced differences in expression of host genes providing insight into the biological processes involved in response to drugs in bacteria and fungi. Moreover, this methodology could be tested for typing of the genome response of any organism to physical or chemical stress factors.

Determination of the antibiofilm, antiadhesive, and anti-MRSA activities of seven Salvia species

Background:Several Salvia species are indigenous to Jordan and are widely used as beverages and spices and for their medicinal properties. The objective of the study was to establish the antimicrobial activities, including the antiadhesive and antibiofilm effects of seven different Salvia species.Materials and Methods:Methods used for planktonic culture included agar diffusion, broth microdilution, and minimal biocidal concentration determination while viable count was used for the determination of the antibiofilm and antiadhesion activities. Overnight cultures of reference strains of Candida albicans, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus and clinical strains of methicillin-resistant S. aureus (MRSA) were used as test microorganisms.Results:An antimicrobial activity toward planktonic cultures demonstrated a significant bacteriocidal activity (≥4 log cycle reduction) for the S. triloba extract against S. aureus including MRSA. Its volatile oil exhibited an antimicrobial activity covering all tested microorganisms with the exception of P. aeruginosa. S. triloba extract and volatile oil were successful in preventing and controlling the biofilm, demonstrating antiadhesion and antibiofilm activities, respectively.Conclusion:These reported activities for S. triloba extract and volatile oil allows their listing as potential antibiofilm and anti-MRSA natural agents. This might suggest their use as an antiseptic in the prophylaxis and treatment of S. aureus-associated skin infections. The antimicrobial activity of the other tested Salvia species was negligible.

The role of salivary factors in persistent oral carriage of Candida in humans

Background Candida albicans is a commensal oral yeast in approximately one-third to one-half of the healthy population. To date, there are no studies investigating the multiple anti-candidal salivary constituents of healthy individuals with either nil or, consistent oral yeast carriage. Objective To compare the composition and anti-candidal activity in stimulated whole saliva of healthy ‘consistent’ oral Candida carriers with Candida-free individuals. Methods A sub-sample of 22 consistent, Candida-free individuals and 10 consistent Candida carriers were recruited from a 12 months screening study investigating oral Candida carriage in 97 healthy patients treated by fixed orthodontic appliances. Unstimulated and stimulated saliva samples were collected. The following salivary attributes were measured using standard methodology: the flow rate, pH, lysozyme, lactoferrin and IgA concentration and, the degree of inhibition of blastoconidial growth and blastospore germination. Results Saliva from the Candida-free individuals showed 20.2% higher inhibition of blastoconidial growth ( p < 0.05) of a reference strain of Candida albicans. No significant differences between the other salivary attributes of the two groups were found. Conclusion The fact that saliva of Candida-free individuals significantly inhibited the blastoconidial growth more than Candida-carriers ( p < 0.05) suggests that saliva may play a role in modulating oral candidal populations in health. Further studies, with a larger cohort are needed to confirm these findings and determine the factors that confer enhanced salivary anti-candidal activity.