Pz Values Research Articles

Wild and partially synanthropic bird yeast diversity, in vitro virulence, and antifungal susceptibility of Candida parapsilosis and Candida tropicalis strains isolated from feces.

Yeast complexes in the fecal samples of wild (Dendrocopos major, Picus viridis) and partially synanthropic (Bombycilla garrulus, Garrulus glandarius, Pica pica, and Pyrrhula pyrrhula) birds were studied in a forest ecosystem during winter. A total of 18 yeast species were identified: 16 ascomycetes and two basidiomycetes belonging to five subphyla of fungi: Saccharomycotina (15), Pezizomycotina (1), Agaricomycotina (1), and Pucciniomycotina (1). Most yeast species were found in the fecal samples of P. pyrrhula (Candida parapsilosis, C. zeylanoides, Debaryomyces hansenii, Hanseniaspora uvarum, Metschnikowia pulcherrima, Meyerozyma carpophila, M. guilliermondii, Rhodotorula mucilaginosa); the lowest number of yeast species was observed in the feces of B. garrulus (C. parapsilosis, C. zeylanoides, Met. pulcherrima, and Rh. mucilaginosa). The opportunistic species of the genus Candida were found only in feces of partially synanthropic birds: C. parapsilosis was observed in the feces of B. garrulus, G. glandarius, P. pica, and P. pyrrhula; its relative abundance was 69.3%, 49.1%, 10.5%, and 1.1%, respectively; C. tropicalis was observed in the feces of P. pica and G. glandarius; its relative abundance was 54.6% and 7.1%, respectively. Strains of C. parapsilosis and C. tropicalis isolated from the feces of partially synanthropic birds were evaluated for their susceptibility to conventional antifungal agents (fluconazole, voriconazole, amphotericin B) and hydrolytic activity. A total of 160 strains were studied. Resistance to fluconazole was detected in 86.8% of C. parapsilosis strains and in 87% of C. tropicalis strains; resistance to voriconazole was detected in 71.7% of C. parapsilosis and in 66.7% of C. tropicalis strains, and the lowest percentage of resistant strains was detected to amphotericin B, 2.8% and 3.7% in C. parapsilosis and C. tropicalis strains, respectively. Multiresistance was detected in one strain of C. parapsilosis isolated from P. pica feces and in one strain of C. tropicalis isolated from G. glandarius feces. Phospholipase and hemolysin activities in the strains of C. parapsilosis were low (mean Pz values of 0.93 and 0.91, respectively); protease activity was moderate (mean Pz value of 0.53). The ability to produce hydrolytic enzymes was higher in the isolated strains of C. tropicalis. The mean Pz values of phospholipase and hemolysin activities were moderate (mean Pz values of 0.63 and 0.60, respectively), whereas protease activity was high (mean Pz value of 0.32). Thus, wild and partially synanthropic birds play an important role in disseminating of various yeast species. These yeasts can enter the topsoil via feces and contribute to the formation of allochthonous and uneven soil yeast diversity in natural ecosystems. In addition, partially synanthropic birds can be vectors of virulent strains of opportunistic Candida species from urban environments to natural biotopes.

Comparison of semi‐empirical and density functional approaches for the colour and constitution of anthraquinone dyes using X‐ray structure

AbstractTheoretical calculations with density functional theory, semi‐empirical PM5 random phase approximation and Zerner's intermediate neglect of differential overlap CI were carried out for various amino and hydroxy anthraquinones using X‐ray structure data. Comparing quantum chemical calculation results based on X‐ray structure, the PM5 random phase approximation method was the most promising for the prediction of λmax for anthraquinone dyes among the computational methods studied here. From the results of calculated gross population, pz, it was found that the value of pz using the time‐dependent density functional theory method was greater than the values calculated by semi‐empirical methods. The overestimation of pz could be attributed to the incorrect density functional theory calculation results. The results of PM5 random phase approximation‐calculated oscillator strength and torsion angle showed reasonable agreement with the observed results for sterically hindered anthraquinone dyes.

Surface Flattening of Directed Energy Deposited Parts through Jet Electrochemical Machining

For additive manufacturing (AM) processes, post-processing is usually needed before application, and electrochemical machining is considered a promising candidate for this purpose. Here, the possibility of using jet electrochemical machining (Jet-ECM) as a semi-finishing post-processing for directed energy deposition (DED) was investigated. The main purpose is to flatten the wave-like surface and improve dimensional accuracy. First, polarization, EIS, and current efficiency measurements were conducted, and it was found that the electrochemical dissolution behaviors of the DED-produced Inconel 718 alloy in NaNO3 solution were isotropic and irrelevant to the DED parameters, which can be attributed to the effect of the passive film. Pa and Pz values from the primary profile were considered more suitable than surface roughness for the characterization of the surface flatness. In the Jet-ECM experiments, the small inter-electrode gaps and high applied voltages were found to be beneficial to surface flattening, while the influence of the scanning speed was not evident. Multiple reciprocating scans could further improve the surface flatness, but most of the improvements were obtained in the first scan. This demonstrates the great potential of Jet-ECM in the post-processing of AM parts, and provide several essential guidelines for further researches.

The effects of secreted aspartyl proteinase inhibitor ritonavir on azoles‐resistant strains of Candida albicans as well as regulatory role of SAP2 and ERG11

Background Candida albicans, the main human fungal pathogen, can cause fungal infection and seriously affect people's health and life. This study aimed to investigate the effects of ritonavir (RIT) on C. albicans and the correlation between SAP2 as well as ERG11 and drug resistance.ResultsSecreted aspartyl proteinases (Saps) activities and pathogenicity of C. albicans with different drug resistance were measured. M27‐A4 broth microdilution method was used to analyze the drug sensitivity of RIT combined with fluconazole (FCA) on C. albicans. After that, SAP2 and ERG11 mutations were examined by polymerase chain reaction (PCR) and sequencing, and quantitative real‐time PCR was utilized to determine the expression of the two genes. By analyzing pz values, the Saps activity of cross‐resistant strains was the highest, followed by voriconazole (VRC)‐resistant strains, FCA‐resistant strains, itraconazole (ITR)‐resistant strains, and sensitive strains. The pathogenicity of C. albicans in descending order was as follows: cross‐resistant strains, VRC‐resistant strains, ITR‐resistant strains, FCA‐resistant strains, and sensitive strains. With the increase of RIT concentrations, the Saps activity was gradually inhibited. Drug sensitivity results showed that there was no synergistic effect between RIT and FCA. Additionally, no gene mutation sites were found in SAP2 sequencing, and 17 synonymous mutations and 6 missense mutations occurred in ERG11 sequencing. Finally, the expression of SAP2 and ERG11 was significantly higher in the resistant strains compared with the sensitive strains, and there was a positive liner correlation between SAP2 and ERG11 messenger RNA expression (r = .6655, p < .001).ConclusionThese findings may help to improve our understanding of azole‐resistant mechanisms of C. albicans and provide a novel direction for clinical therapeutics of C. albicans infection.

Virulence of “white-gray-opaque” tri-stable transformation in clinical Candida albicans in vitro and in vivo

The study aimed to induce the white-opaque-gray tri-stable transformation in clinical C. albicans and to explore their potential pathogenicity. Sixty-four clinical strains were used to induce the white, opaque and gray cells of C. albicans. Secreted aspartyl proteinases (Sap) activity of the three phenotypes was then measured, and a vulvovaginal candidiasis (VVC) animal model was constructed. Of the 64 clinical strains, only 3 strains successfully underwent white-gray-opaque tri-stable transformation, and the three strains all belonged to MTL homozygous strains. Pz values in white, opaque and gray phenotypes were 0.834 ± 0.012, 0.707 ± 0.036, and 0.628 ± 0.002, respectively, which indicated that the cells with gray phenotype had higher Sap activity. After inoculation of different fungal suspension, the fungal colony count in descending order was as follows: gray phenotype, opaque phenotype and white phenotype. After treated with fluconazole for 3 days or 10 days, the fungal colony counts were significantly decreased compared with that before treatment (P < 0.05). The Sap activity and pathogenicity of gray cells in C. albicans were the strongest, followed by opaque cells and white cells. Additionally, white, gray and opaque phenotypic cells were all susceptible to fluconazole.

Kan ve Oral Kavite Örneklerinden Soyutlanan Candida albicans Suşlarının Fosfolipaz Aktivitelerinin Araştırılması

Objective: The aim of the present study was to investigate and compare the phospholipase B1, B2, C1 and D1 activities in C.albicans strains isolated from blood cultures and oral cavity specimens. Method: Phospholipase activity of the strains was examined by plate method and reverse transcriptase polymerase chain reaction (RT-PZT). Results: Twenty-six (86.7%) strains isolated from blood and 24 (80.0%) from oral cavities revealed phospholipase activity by plate method. No statistically significant difference (χ2 =0.48; p=0.49) was observed between the groups. However statistical difference was determined between the mean Pz values (0.6138±0.9823; 0.6988±0.9910) (p=0.007). PLB1 expression was detected in all (100%), PLB2 in 29 (96.7%) and 30 (100.0%), PLC1 in 27 (90%) and 22 (73.3%), PLD1 in 27 (90.0%) and 21 (70.0%) of blood and oral strains, respectively. While no significant difference was detected between PLB1 expression values of the groups (t=-0.307; p=0.760), PLB2 and PLC1 expressions were found to be significantly higher in blood (p=0.043) and oral cavity isolates (p&lt;0.001), respectively. No difference was observed between PLD1 expressions (p=0.732). PLB1, PLB2, PLC1 and PLD1 expressions were 100%, 81.7%, 71.6% and 76.7% in agreement with the plate method. The agreement was 83.3% when all the phospholipase genes were considered. No correlation was detected between the Pz values and phospholipase expressions (p=0.602; p=0.555; p=0.241; p=0,096, respectively). Conclusion: The high rates of phospholipase activity of the C.albicans isolates in our study, support the important roles of these enzymes in virulence. Our results may indicate that phospholipase enzymes encoded by PLB2 and PLC1 genes play more important roles for invasive and oral cavity infections, respectively; however large scale studies are needed on this issue.

Investigation of the hardening behavior during recrystallization annealing in Al-Mg-Sc alloy

In this work, Al-3Mg-0.2Sc alloy with a single pass friction stir processing (FSP) was cold rolled, followed by recrystallization annealing. Hardening behavior was observed in cold rolled alloy after annealing treatment at 330 °C and 400 °C. The hardening phenomenon can be rationalized by a calculation between the Zener pinning (PZ) and the driving force of recrystallization (PDRex). The result of contrastive calculation accords with the hardness change in the early stage of annealing, while the characteristics about coherency of Al3Sc particles determine that the contrastive calculation is inapplicable to later period of annealing. Specifically, the destruction of coherency between Al3Sc particles and matrix after annealing time exceeds 75 min makes that the actual value of PZ is much less than the predicted value of calculation.

In vitro activities of Traganum nudatum and Mentha pulegium extracts combined with amphotericin B against Candida albicans in production of hydrolytic enzymes.

Background and Purpose : Candida albicans is an important microorganism in the normal flora of a healthy subject; however, it has an expedient pathogenic character that induces hydrolytic virulence. Regarding this, the present study aimed to find an in vitro alternative that could reduce the virulence of this yeast.Materials and Methods: For the purpose of the study, the effect of amphotericin B (AmB) combined with the extract of Traganum nudatum (E1) or Mentha pulegium (E2) was evaluated against the hydrolytic activities of esterase, protease, and phospholipase. This effect was determined by calculating the minimum inhibitory concentration (MIC), used to adjust the extract/AmB mixtures in culture media.Results: The evaluated Pz values, which corresponded to the different enzymatic activities, showed a decrease in the hydrolytic activities of C. albicans strains after the addition of E1/AmB and E2/AmB combinations at descending concentrations (lower than the obtained MICs).Conclusion: Based on the findings, it would be possible to reduce the pathogenesis of this species without destabilizing the balance of the flora.

Isolation and Diagnosis of Candida albicans Yeast From Patients Infected With Oral Candidiasis in Mosul City and Study its Activity in Production of Phospholipase and Hemolycin

In this study, 63 oral swabs were collected . Thirty six yeast isolates were obtained (57.14%) grown on sabouraud dextrose agar medium (SDA). Symbols were given to isolates from RA1 to RA36 in order to differentiate them. The isolates were identified by growth on HiCrome Candida differential agar M1297A and identification by Vitek 2 Compact system. The identification results showed 5 species of the isolated yeasts belonging to the genus Candida, 29 isolates belonging to the species C. albicans (80.55%) and one species from C. famata, C. glabrata, C. kefyr and C. lusitaniae (2.77% for each species). Moreover one isolate was obtained from each of the following yeasts: Saccharomyces serevisiae, Malassezia furfur and Rhodotorula glutinis (2.77% for each one). This study included the evaluation of two virulence factors for all C. albicans isolates , phospholipase enzyme production on egg yolk agar and hemolytic activity on sugar-enriched sheep blood agar. . Phospholipase production test showed differences in phospholipase production among the isolates , twenty three isolates (79.31%) were producers and precipitation zone (Opaque zone) was observed around the grown colonies with different Pz values and the isolate RA13 exhibited highest activity (Pz value = 0.53). The results showed also that all isolates were producers of hemolysin with different hemolytic indexes (Hi). Isolate RA7 represented the highest one in activity (Hi = 2.16). Hemolysis of all isolates involved beta hemolysis.

Antifungal resistance profile and enzymatic activity of Candida species recovered from human and animal samples

Candida is currently the most implicated pathogenic fungal species recognized as the major cause of a variety of human infections all over the world. This study investigated species distribution, enzymatic activities, and antifungal resistance profiles of human and animal Candida species. Clinical Candida species (n=220) were isolated from urine, high vaginal swab (HVS) and blood while Candida species (n=128) were isolated from rectal swab, ear swab, blood, feces, and milk in animals: goat, sheep, cattle, pig and chicken. The identification of the species was performed using standard methods. Enzymatic activity was screened using plate methods. Susceptibility testing was carried out using disk diffusion and broth microdilution methods. A statistically significant difference (P=0.031) was observed in the distribution of Candida spp. recovered from humans and animals. The Pz values of human Candida species for proteinase, hemolysin, lipase and phospholipase were 0.65±0.97, 0.61±0.81, 0.59±0.47 and 0.76±0.74 respectively while that of Candida species recovered from animal were 0.67±0.13, 0.61±0.95, 0.62±0.67 and 0.69±0.70 respectively. No statistically significant difference (P&gt;0.05) in the in vitro enzymatic activity was observed between the two groups. High azole-resistance rate was observed. Resistance was higher among human Candida isolates compared to animal isolates although the difference was not considered statistically significant (p = 0.519). Our findings suggest that the enzymatic activity (virulence potential) and resistance patterns are similar in the two groups investigated. This study underscores the importance of animals especially pets and their products as potential sources/reservoirs of pathogenic and multi-azole resistant Candida species in Nigeria.

Bioadhesive Matrix Tablets Loaded with Lipophilic Nanoparticles as Vehicles for Drugs for Periodontitis Treatment: Development and Characterization.

Periodontitis treatment is usually focused on the reduction or eradication of periodontal pathogens using antibiotics against anaerobic bacteria, such as metronidazole (MTR). Moreover, recently the correlation between periodontal diseases and overexpression of reactive oxygen species (ROS) led to the introduction of antioxidant biomolecules in therapy. In this work, bioadhesive buccal tablets, consisting of a hydrophilic matrix loaded with metronidazole and lipophilic nanoparticles as a vehicle of curcumin, were developed. Curcumin (CUR)-loaded nanostructured lipid carriers (NLC) were prepared using glycyrrhetic acid, hexadecanol, isopropyl palmitate and Tween®80 as a surfactant. As method, homogenization followed by high-frequency sonication was used. After dialysis, CUR-NLC dispersion was evaluated in terms of drug loading (DL, 2.2% w/w) and drug recovery (DR, 88% w/w). NLC, characterized by dynamic light scattering and scanning electron microscopy (SEM), exhibited a spherical shape, an average particle size of 121.6 nm and PDI and PZ values considered optimal for a colloidal nanoparticle dispersion indicating good stability of the system. Subsequently, a hydrophilic sponge was obtained by lyophilization of a gel based on trehalose, Natrosol and PVP-K90, loaded with CUR-NLC and MTR. By compression of the sponge, matrix tablets were obtained and characterized in term of porosity, swelling index, mucoadhesion and drugs release. The ability of the matrix tablets to release CUR and MTR when applied on buccal mucosa and the aptitude of actives to penetrate and/or permeate the tissue were evaluated. The data demonstrate the ability of NLC to promote the penetration of CUR into the lipophilic domains of the mucosal membrane, while MTR can penetrate and permeate the mucosal tissue, where it can perform a loco-regional antibacterial activity. These results strongly support the possibility of using this novel matrix tablet for delivering MTR together with CUR for topical treatment of periodontal diseases.

Extracellular Protease and DNase Activities in Clinical and Environmental Isolates of Cryptococcus neoformans Species Complex from Central India

Enzymes are important not only for the growth and multiplication of the microorganism but also in the infection, penetration of the host tissue and encountering host defense mechanisms. This study aims to investigate extracellular protease and DNase activity in clinical (20) and 120 environmental isolates of C. neoformans species complex collected from different localities of central India. DNase test agar containing toluidine blue and Yeast Carbon Base (YCB) agar medium supplemented with 0.1% BSA + 0.01% polypeptone was employed for the screening of DNase and protease production respectively. DNase and protease production was detected by the appearance of clear zones around the colonies. On the basis of enzymatic activity and their Pz values, high protease production (Pz≤0.6) was observed by 14 (11.6 %) environmental and 4 (11.6 %) clinical strains on 5th day, whereas 35 (29.16 %) environmental and 8 (40 %) clinical strains were screened on 8th day of incubation. Similarly 13 (10.83%) environmental and 3 (15 %) clinical strains on the 5th day, however 32 (26.66%) environmental and 8 (40 %) clinical strains on the 8th day of incubation were found to be high DNase producing strains with low Pz value (Pz≤0.6). In the case of protease activity, no significant difference was observed whereas a significant difference has shown by clinical C. neoformans and C. gattii strains on the 5th day of DNase production (p &lt; .001). Extracellular enzymes play a vital role in the pathogenicity and virulence of C. neoformans species complex, therefore, enzymes are considered as worthy targets for developing therapeutics. Keywords: Cryptococcus neoformans species complex, Extracellular enzymes, DNase, protease, virulence, Pz value

Comparative analysis of proteinase, phospholipase, hydrophobicity and biofilm forming ability in Candida species isolated from clinical specimens

Candida species are the commensal organisms of human and animal mucosa that cause a wide range of debilitating diseases in immunocompromised patients and other susceptible individuals. The present study aimed to investigate the ability of clinical isolates of various Candida species to produce proteinase and phospholipase, hydrophobicity and biofilm forming ability that assumed to have a vital role in Candida pathogenicity. Eighty-four Candida strains belonged to Candida albicans (44.1%), C. glabrata (5.9%), C. guilliermondii (5.9%), C. krusei (10.8%), C. parapsilosis (26.2%), and C. tropicalis (7.1%) were examined for proteinase and phospholipase production, cell surface hydrophobicity and biofilm forming ability. The production of proteinase and phospholipase was detected in 81 (96.4%) and 79 (94.1%) of the strains, respectively. C. albicans showed the highest proteinase and phospholipase activity (mean Pz values of 0.42±0.25 and 0.72±0.28) and biofilm formation ability (0.66±0.22). C. parapsilosis had the highest hydrophobicity (42.97±16.1), which showed a good correlation with biofilm formation ability. A considerable percentage of non-albicans Candida strains produced significant amounts of proteinase and phospholipase with a good ability of biofilm formation in vitro. Taken together, our results further substantiated that enzymatic activity, hydrophobicity and the ability for biofilm formation are important virulence factors which may be account for pathogenicity of various Candida species distributed in albicans and non-albicans groups.

Studying the Prevalence, Species Distribution, and Detection of In vitro Production of Phospholipase from Candida Isolated from Cases of Invasive Candidiasis.

Background and Aim:Candida spp. have emerged as successful pathogens both in invasive and mucosal infections. C. albicans is the sixth cause of most common nosocomial infections according to studies by the Centers for Disease Control and Prevention. A shift toward non-albicans species has been reported. There is a dearth of knowledge regarding the virulence factors of Candida, especially from this part of India. The aim was to study the prevalence of Candida, speciate, and determine antifungal sensitivity along with the detection of in vitro production of phospholipases in 100 Candida isolates.Materials and Methods:A total of 100 Candida isolates from various clinical specimens were studied (February 1, 2015–May 31, 2015; 4 months). Speciation was done by conventional methods and antifungal drugs fluconazole and voriconazole tested. Phospholipase activity (Pz value) was determined.Results:Of the 100 Candida spp., 35% were C. albicans and 65% were nonalbicans Candida (NAC). Species spectrum was of the 100 isolates as follows: 35 were C. albicans, 17 Candida tropicalis, 6 Candida glabrata, 8 Candida guilliermondi, 1 Candida kefyr, 6 Candida krusei, 14 Candida parapsilosis, 2 Candida lusitaniae, and 1 Trichosporon and 10 Candida spp. (not speciated). Phospholipase production was seen in 81 (81%) of the total isolates. The majority (63%) of phospholipase producers were NAC. Among NAC spp., the maximum phospholipase activity was seen in C. tropicalis (30%) and C. parapsilosis (24%). Of these, 60% of Candida was from patients admitted to the hospital. Sensitivity rates of C. albicans for fluconazole and voriconazole were 89.5% and 90.5%, respectively.Conclusion:Increasing usage of devices, total parenteral nutrition, broad-spectrum antibiotics, chemotherapies, and transplantation are factors contributing to the increase of candidal infections. Recent studies underline the increasing frequency of infections by NAC. The present study showcases the increased prevalence as well as virulence of NAC. In addition, early detection of virulence factors by Candida is useful in clinical decision-making.

Extracellular enzymes and susceptibility to fluconazole in Candida strains isolated from patients with vaginitis and healthy individuals.

Background:Extracellular phospholipase, proteinase, and coagulase are accounted as the major virulence factors in Candida albicans. Several reports showed that the incidence of resistance to fluconazole has risen during last two decades.Objectives:The present study has investigated the extracellular enzymes of C. albicans and non-albicans species isolated from both patients with vaginitis and healthy women. In addition, susceptibility of the isolates was evaluated against fluconazole.Patients and Methods:Vaginal samples were collected using sterile cotton swabs and inoculated on CHROMagar Candida. Routine morphological tests and ID 32C and API 20C AUX Kits were used to identify species. Phospholipase, proteinase, and coagulase activity were determined by standard methods. Susceptibility to fluconazole was also evaluated using ATB Fungus 3 Kits.Results:The phospholipase activity was detected in 66.7% of the tested isolates recovered from patients with vaginitis. In the present study, phospholipase activity with higher Pz values (< 0.70) was more common in patients with vaginitis (28 of 66 isolates) whereas this rate in the normal individual was 13 of 42. Proteinase activity was detected in 74.2% and 61.9% of tested isolates recovered from patients and normal individuals, respectively. All tested isolates were negative for coagulase activity. In the present study, resistance to fluconazole was found in 34.8% of isolates. C. dubliniensis was the most common isolate (6 out of 11 isolates) that showed resistance to fluconazole.Conclusions:Our results showed that C. albicans was the most frequently isolated from both patients with vaginitis and normal individual. In the present study, we could not find any correlation between extracellular activities and sources of isolates (patients and normal flora) and sensitivity or resistance to fluconazole.

Detection of phospholipase activity of Candida albicans and non albicans isolated from women of reproductive age with vulvovaginal candidiasis in rural area.

Vulvovaginal candidiasis (VVC) is most common accounting for 17 to 39% of symptomatic women. Both Candida albicans and non albicans Candida species are involved in VVC. Amongst various virulence factors proposed for Candida, extracellular phospholipases is one of the virulence factor implicated in its pathogenicity. With this background the present study was carried out to find the prevalence of different Candida species and to detect phospholipase producing strains isolated from symptomatic women with VVC. At least two vaginal swabs from 156 women of reproductive age with abnormal vaginal discharge were collected. Direct microscopy and Gram's stained smear examined for presence of budding yeast and pseudo mycelia followed by isolation and identification of Candida species. Extracellular phospholipase activity was studied by inoculating all isolates on Sabouraud's dextrose egg yolk agar (SDA) medium. Of the 156 women with curdy white discharge alone or in combination with other signs, 59 (37.82%) women showed laboratory evidence of VVC. A total of 31 (52.54%) women had curdy white discharge followed by 12 (20.33%) with other signs and symptoms. C. albicans (62.59%) and non albicans Candida (37.28%) in a ratio of 1.68:1 were isolated. Of the 37 strains of C. albians 30 (81.08%) showed the enzyme activity. Seventeen (56.66%) strains showed higher Pz value of < 0.70 (++++). Although there may be typical clinical presentation of Candidiasis. all the patients did not show laboratory evidence of infection. Pregnancy was found to be major risk factor for development of VVC. C. albicans was prevalent species but non albicans species were also frequently isolated. Extracellular phospholipase activity was seen in C. albicans and not in non albicans Candida isolates.

Enzymatic activity profile of a Brazilian culture collection of Candida albicans isolated from diabetics and non‐diabetics with oral candidiasis

The secretion of hydrolytic enzymes is a fundamental virulence factor of Candida albicans to develop disease. The objective of this study was to characterise the virulence of 148 clinical isolates of C. albicans from oral candidiasis by assessing the expression of phospholipase (PL) and secreted aspartyl proteinase (SAP). Isolates were obtained from healthy subjects (HS) and diabetics (DOC) and non-diabetics with oral candidiasis (NDOC). An aliquot (5μl) of each cell suspension was inoculated on PL and SAP agar plates and incubated. Enzymes secretion was detected by the formation of an opaque halo around the colonies and enzymatic activity (PZ) was determined by the ratio between colony diameter and colony diameter plus the halo zone. Statistical comparisons were made by a one-way anova followed by Tukey's post hoc test (α=0.05). The clinical sources of C. albicans had significant effect (P<0.001) on the PZ values of both enzymes. For PL, clinical isolates from NDOC and DOC had highest enzymatic activity than those from HS (P<0.05), with no significant differences between them (P=0.506). For SAP, C. albicans from NDOC showed the lower enzymatic activity (P<0.001). There were no significant differences between isolates from HS and DOC (P=0.7051). C. albicans isolates from NDOC and DOC patients showed an increased production of PL.

Selection of the Electrolyte Solution by Applying Electro-kinetic Treatment of Lead Contaminated Soil

In electrokinetic treatment of contaminated soils three transport phenomena are induced in soil solution: electroosmosis, electrophoresis and (1). These help in the extraction of contaminants and can be optimized by modifying conditions of the soil solution. Of the most important factors to consider are: soil type, electrolytic medium composition and current values. In this work first a model soil (sand A100) was characterized and its zeta potential (pZ) was measured varying electrolytes, pH and intensity of current. This in order to select the most appropriate parameters to be used in electrokinetic treatment. Since when the pZ is in the range of -30 to +30 mV colloidal particles (soil dispersion) tend to agglomerate hampering electrokinetic treatment it is recommended to work with pZ values outside this range. It was observed that dispersion using NH4AcO as electrolyte introduced a lower pZ value, so it is best to be used in electrokinetic treatment.

The Effect of Gentian Violet on Virulent Properties of Candida albicans

The aim of this study was to evaluate the effect of gentian violet (GV) on phospholipase activity, proteinase activity and germ tube formation rate of Candida albicans. Both 12 phospholipase-positive and 12 proteinase-positive C. albicans isolates with Pz values <or=0.89 were obtained. A yeast suspension (1-3 x 10(7) cfu/ml) of each isolate was prepared. After a brief exposure (60 min) to sub-therapeutic concentrations (0.5 or 2 microg/ml) of GV, Pz value of phospholipase, Pz value of proteinase and germ tube formation rate were determined. Phospholipase activity, proteinase activity and germ tube formation rate in two groups exposed to GV were significantly lower than those in the group unexposed (P < 0.05). The results of this study indicated that sub-therapeutic concentrations of GV may lead to reduction in phospholipase activity, proteinase activity and germ tube formation, and then may suppress virulence and pathogenicity of C. albicans.

High energy emission and polarisation limits for the INTEGRAL burst GRB 061122

(Abridged) GRB 061122 is one of the brightest GRBs detected within INTEGRAL's field of view to date. The two gamma-ray detectors on INTEGRAL were used to investigate the spectral characteristics of GRB 061122. A search for linear polarisation in the prompt emission was carried out using the SPI multiple event data in the energy range 100 keV-1 MeV. The prompt spectrum was best fit by a combination of a blackbody and a power--law model (the quasithermal model), with evidence for high energy emission continuing above 8 MeV. A pseudo-redshift value of pz = 0.95 +/- 0.18 was determined using the spectral fit parameters. The isotropic energy at this pseudo-redshift is 8.5 x 10^{52} erg. The jet opening angle was estimated to be smaller than 2.8 deg or larger than 11.9 deg from the X-ray lightcurve. An upper limit of 60% polarisation was determined for the prompt emission of GRB 061122, using the multiple event data. The high energy emission observed in the spectrum may be due to the reverse shock interacting with the GRB ejecta when it is decelerated by the circumburst medium. This behaviour has been observed in a small fraction of GRBs to date, but is expected to be more commonly observed by the Fermi Gamma-ray Space Telescope. The conditions for polarisation are met if the jet opening angle is less than 2.8 deg, but further constraints on the level of polarisation are not possible.