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Objective Ability to produce hemolysin by Candida species is an important determinant of its pathogenicity. Candida dubliniensis is implicated in the causation of oral candidosis, which can be treated with polyene, echinocandin, and azole groups of antifungal agents as well as chlorhexidine. After oral application, however, the concentrations of these agents tend to decrease quickly to subtherapeutic levels due to the peculiarity of the oral environment. In this study, we have evaluated the effect of short-term exposure of sublethal concentrations of these drugs on hemolysin production by oral C. dubliniensis isolates obtained from two different geographical locale. Materials and methods Twenty C. dubliniensis oral isolates obtained from Kuwait and Sri Lanka were exposed to sublethal concentrations of nystatin, amphotericin B, caspofungin, ketoconazole, fluconazole, and chlorhexidine for 1 h. Thereafter, the drugs were removed by dilution and the hemolysin production determined by a previously described plate assay. Results Hemolysin production of these isolates was significantly suppressed with a percentage reduction of 17.09, 16.45, 17.09, 11.39, 8.23 and 12.03 following exposure to nystatin, amphotericin B, caspofungin, ketoconazole, fluconazole, and chlorhexidine, respectively. Conclusion Brief exposure to sublethal concentrations of drugs with antifungal properties appears to reduce the pathogenic potential of C. dubliniensis isolates by suppressing hemolysin production. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the anti-Candida activity on Candida albicans and Candida dubliniensis species of 2 herbal and 7 other brands of toothpastes commonly used in Kuwait. Materials and Methods: Antifungal activity was determined by agar diffusion test on 65 isolates of C. albicans and 21 isolates of C. dubliniensis for each toothpaste. A uniform quantity of toothpaste was filled into wells punched into Sabouraud dextrose agar medium plates inoculated with the test isolates, incubated at 37°C; inhibition zone diameters were read after 24 h. Results: The mean inhibition zone diameters ranged between 12 and 23 mm for C. albicans and between 12 and 27 mm for C. dubliniensis. A herbal toothpaste brand manufactured in the Middle Eastern region (United Arab Emirates) consisting of many herbal ingredients compared to other brands was found to be the most active (p < 0.001) against both Candida species tested, which also demonstrated higher inhibitory activity against C. dubliniensis isolates compared to C. albicans.Conclusions: The herbal toothpaste brand presented significant anticandidal activity over conventional toothpastes and may be useful in reducing the pathogenic potential of Candida species. Copyright © 2011 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Evaluates the investigative methods in assessing the adhesion and cell surface hydrophobicity of Candida species. Impact of adhesion of microorganisms on biological and inert surfaces; Application of biphasic hydrocarbon-aqueous phase in cell surface hydrophobicity; Process of candidal adhesion to biological and inert surfaces.

Setaria digitata is a nematode that resides in the peritoneal cavity of ruminants causing cerebrospinal nematodiasis disease affecting livestock and inflicting significant economic forfeitures in Asia. Further, this nematode can infect humans, causing abscesses, allergic reactions, enlarged lymph nodes, eye lesions and inflammation of the lungs. The 'ARE2 required for viability1' (ARV1) encodes for putative lipid transporter localized in the endoplasmic reticulum (ER) and Golgi complex membrane in humans and yeast. In the present study, the functional role of S. digitata ARV1 (SD-ARV1) was investigated using RNA interference (RNAi) reverse genetic tool. The targeted silencing SD-ARV1 transcripts by siRNA mediated RNAi resulted in a dramatic reduction of SD-ARV1 gene and protein expressions in S. digitata, which in turn modulated the parasitic motility, its production of eggs and microfilaria viability. Further, the same silencing caused severe phenotypic deformities such as distortion of eggs and embryonic development arrest in the intrauterine stages of adult female S. digitata. These results suggest that SD-ARV1 plays a pivotal role in worm embryogenesis, adult parasite motility and microfilariae viability. Finally, the ubiquitous presence of ARV1 in human filarial nematodes, its crucial functional roles in nematode biology and its remarkable diversity in primary protein structure compared to homologues in their hosts warrants further investigations to ascertain its candidacy in anthelmintic drug development., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Aim: The aim of the present study was to investigate factors associated with denture-induced stomatitis (DIS) among denture wearers and their oral and hand carriage of Candida., Methods: Sociodemographics and denture and oral hygiene practices were investigated using an interviewer-administered questionnaire in denture wearers with DIS (n = 60) and without DIS (n = 60) selected using a convenience sampling of patients attending the Department of Prosthetic Dentistry, University of Peradeniya, Sri Lanka. Denture and oral hygiene practices and denture quality were scored. DIS and denture hygiene were classified. Oral and hand carriage of Candida was assessed., Results: Middle-aged females were more prone to DIS. The most common DIS pattern was Newton type ΙΙ. The mean age of existing denture of DIS patients was significantly higher than the control. Denture hygiene practice was significantly low in DIS patients. Poor denture hygiene practice and sleep wear of dentures were significantly associated with DIS. The risk of Candida hand carriage in a DIS patient carrying oral Candida was significantly higher than the risk of Candida hand carriage in a healthy denture wearer who carried oral Candida., Conclusion: Old dentures, poor denture hygiene, and sleep wear of dentures might contribute to DIS. Oral Candida in denture wearers could lead to Candida hand carriage., (© 2016 John Wiley & Sons Australia, Ltd.)

Objective: Candida albicans is the primary causative agent of oral candidosis, and one of its key virulent attributes is considered to be its ability to produce extracellular phospholipases that facilitate cellular invasion. Oral candidosis can be treated with polyenes, and azoles, and the more recently introduced echinocandins. However, once administered, the intraoral concentration of these drugs tend to be sub-therapeutic and rather transient due to factors such as the diluent effect of saliva and cleansing effect of the oral musculature. Hence, intra-orally, the pathogenic yeasts may undergo a brief exposure to antifungal drugs. We, therefore, evaluated the phospholipase production of oral C. albicans isolates following brief exposure to sub-therapeutic concentrations of the foregoing antifungals., Materials and Methods: Fifty C. albicans oral isolates obtained from smokers, diabetics, asthmatics using steroid inhalers, partial denture wearers and healthy individuals were exposed to sub-therapeutic concentrations of nystatin, amphotericin B, caspofungin, ketoconazole and fluconazole for one hour. Thereafter the drugs were removed and the phospholipase production was determined by a plate assay using an egg yolk-agar medium., Results: The phospholipase production of these isolates was significantly suppressed with a percentage reduction of 10.65, 12.14, 11.45 and 6.40% following exposure to nystatin, amphotericin B, caspofungin and ketoconazole, respectively. This suppression was not significant following exposure to fluconazole., Conclusions: Despite the sub-therapeutic, intra oral, bioavailability of polyenes, echinocandins and ketoconazole, they are likely to produce a persistent antifungal effect by suppressing phospholipase production, which is a key virulent attribute of this common pathogenic yeast., (Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.)

Aim: Candida adherence is implicated in the pathogenesis of oral candidosis. Adhesion to buccal epithelial cells (BEC), germ tube (GT) formation, and relative cell surface hydrophobicity (CSH) are colonization attributes of candidal pathogenicity. Candida dubliniensis (C. dubliniensis) is allied with recurrent oral candidosis, which can be treated with nystatin, amphotericin B, ketoconazole, and fluconazole. Due to the diluent effect of saliva and the cleansing effect of the oral musculature in the oral cavity C. dubliniensis isolates undergo brief and sequential exposure to antifungal agents during therapy. Thus, in the present study, we evaluated the adhesion to BEC, GT formation, and the CSH of oral isolates of C. dubliniensis following brief and sequential exposure to nystatin, amphotericin B, ketoconazole, and fluconazole., Methods: After determining the minimum inhibitory concentration (MIC) of the aforementioned drugs, 20 oral isolates of C. dubliniensis were briefly (1 h), and sequentially (10 days) exposed to subcidal concentrations of these drugs. Following drug removal, adhesion to BEC, GT formation, and CSH of these isolates were determined., Results: The percentage reduction of adhesion to BEC, GT formation, and CSH of the isolates following exposure to antifungal agents were as follows: nystatin: 53.55%, 33.98%, and 29.83% (P < 0.001); amphotericin B: 53.84%, 36.23%, and 28.97% (P < 0.001); ketoconazole: 37.43%, 20.51%, and 16.49% (P < 0.001); and fluconazole: 8.93% (P < 0.001), 1.6%, and 0.63% (P > 0.05)., Conclusions: Brief and sequential exposure of C. dubliniensis to antifungal agents would continue to wield an antifungal effect by altering its adhesion attributes, and elucidate possible pharmacodynamics by which antifungal agents might operate in modulating candidal adherence., (© 2014 Wiley Publishing Asia Pty Ltd.)

Objective: Candida albicans and its non-albicans counterparts, such as C. tropicalis, C. krusei, C. glabrata and C. dubliniensis, are the major etiological agents of oral candidosis. Their adherence to buccal epithelial cells (BEC), denture acrylic surfaces (DAS) and cell surface hydrophobicity (CSH) are attributes associated with yeast colonization and infection. Chlorhexidine gluconate (CG) is a widely used antiseptic in dentistry. When administered, the diluent effect of saliva and the cleansing effect of the oral musculature reduce its bioavailability, compromising its efficacy. Hence, intraorally, Candida undergoes a transient exposure to high CG concentrations, and thereafter it is likely to be subtherapeutic. Therefore, the impact of CG on adhesion to BEC, DAS and CSH of different oral Candida species was investigated following brief exposure to three subtherapeutic concentrations of CG., Materials and Methods: Ten oral isolates of each of the above five Candida species obtained in Kuwait from oral rinse samples were exposed to 0.00125, 0.0025 and 0.005% CG for 30 min. Subsequently, the yeast adhesion to BEC, DAS and CSH was determined. The data were analyzed using ANOVA Dunnett's t tests., Results: Exposure to the lowest dilution (0.00125%) of CG did not elicit a noteworthy collective suppression on all three adhesion traits evaluated. Exposure to 0.0025% CG curtailed the adhesion to BEC, DAS and CSH of Candida species by 50.89, 40.79 and 24.58%, respectively (p < 0.001). Exposure to the highest concentration (0.005%) of CG reduced the adhesion to BEC, DAS and CSH of Candida species by 64.68, 54.59 and 50%, respectively (p < 0.001)., Conclusions: Brief exposure to subtherapeutic concentrations of CG suppressed the adhesion to BEC, DAS and CSH of oral Candida species, indicating probable pharmacodynamics that may potentiate its antiseptic properties., (© 2016 S. Karger AG, Basel.)

Although several studies have been conducted to assess dentists' knowledge of and attitudes towards human immunodeficiency virus (HIV)/acquired immune-deficiency syndrome (AIDS), few have targeted dental assistants. The main aims of this study were to assess the knowledge of and attitudes towards HIV/AIDS among dental assistants in Kuwait and to compare the knowledge and attitudes of dental assistants at Kuwait University Dental Center (KUDC) with those of dental assistants in Ministry of Health (MoH) hospitals. The secondary objective was to determine if any intervention was needed to provide more information to dental assistants on HIV/AIDS. A cross-sectional study was conducted by distributing questionnaires. The study sample included 85 dental assistants from each of KUDC and the MoH. The questionnaire included questions to assess the assistants' knowledge and attitude towards HIV/AIDS. Statistical data analysis was conducted using SPSS 20.0. Qualitative data were analysed using the Pearson chi-square text for any association or the Z-test for proportion to test the significance of differences. A total of 167 questionnaires were completed, returned and analysed. KUDC dental assistants were found to have significantly more knowledge about HIV/AIDS than their MoH counterparts, whereas the assistants at the MoH clinics displayed a more positive attitude towards patients with HIV/AIDS (P < 0.05). Although dental assistants at KUDC were more knowledgeable than those at the MoH clinics, there are still some misconceptions that need to be addressed, in addition to the negative attitudes displayed by some of the respondents. It would therefore be beneficial to increase awareness about HIV/AIDS patients through lectures, seminars and workshops targeting dental assistants., (© 2014 FDI World Dental Federation.)

Objectives: We aimed to investigate the effect of brief exposure to sub-cidal concentrations of nystatin, amphotericin B, ketoconazole, fluconazole and chlorhexidine gluconate on the adhesion of oral Candida dubliniensis isolates to the surface of acrylic dentures., Methods: After determining the minimum inhibitory concentration of each drug, 20 oral isolates of C. dubliniensis were exposed to sub-cidal concentrations of the drugs for 1 h. The drugs were then removed by dilution, and the adhesion of the isolates to denture acrylic strips was assessed by an in vitro adhesion assay., Results: Compared to the controls, exposure to nystatin, amphotericin B, ketoconazole, fluconazole and chlorhexidine gluconate suppressed the ability of C. dubliniensis isolates to adhere to acrylic denture surfaces with a reduction of 74.68, 74.27, 57.31, 44.57 and 56.53% (p < 0.001 for all drugs), respectively., Conclusions: Brief exposure to sub-cidal concentrations of anti-mycotics suppressed the adhesion of C. dubliniensis oral isolates to acrylic denture surfaces., (© 2014 S. Karger AG, Basel.)

Objective: To evaluate the impact of brief and sequential exposure to nystatin on the germ tube formation and cell surface hydrophobicity of oral isolates of Candida albicans obtained from patients infected with human immunodeficiency virus (HIV)., Materials and Methods: After determining the minimum inhibitory concentration of nystatin, 10 oral isolates of C. albicans from 10 different HIV-infected patients were briefly (1 h) and sequentially (10 days) exposed to subtherapeutic concentrations of nystatin. Following a subsequent drug removal, the germ tube formation and cell surface hydrophobicity of these isolates were determined via a germ tube induction assay and an aqueous hydrocarbon assay, respectively. The data obtained from these assays for the control (unexposed to nystatin) and nystatin-exposed isolates were analyzed using Student's t tests., Results: The mean percentage reduction in the germ tube formation and cell surface hydrophobicity of the nystatin-exposed isolates compared to the controls was 30.12 ± 1.99 (p < 0.001) and 29.65 ± 2.33 (p < 0.001), respectively., Conclusion: These data elucidate the possible pharmacodynamic mechanisms by which nystatin might operate in vivo in the modulation of candidal virulence., (© 2014 S. Karger AG, Basel.)

Objective: The objective of this study was to determine the cell surface hydrophobicity of 40 oral Candida albicans isolates obtained from smokers, diabetics, asthmatics using steroid inhalers, and healthy individuals, following brief exposure to subtherapeutic concentrations of chlorhexidine gluconate., Materials and Methods: Forty C. albicans oral isolates (10 isolates each from smokers, diabetics, asthmatics using steroid inhalers, and healthy individuals) were exposed to 3 subtherapeutic concentrations of chlorhexidine gluconate (0.00125, 0.0025, and 0.005%) for 30 min. Thereafter, the antiseptic was removed and the cell surface hydrophobicity was measured by a biphasic aqueous-hydrocarbon assay., Results: Compared to the unexposed controls, the cell surface hydrophobicity of C. albicans isolates was suppressed by 5.40% (p > 0.05), 21.17% (p < 0.05), and 44.67% (p < 0.05) following exposure to 0.00125, 0.0025, and 0.005% chlorhexidine gluconate, respectively., Conclusions: A brief period of transient exposure to subtherapeutic concentrations of chlorhexidine gluconate may modulate the cell surface hydrophobicity of C. albicans isolates and thereby may reduce candidal pathogenicity., (Copyright © 2012 S. Karger AG, Basel.)

Several studies regarding knowledge and attitudes of dental students towards HIV/AIDS have been reported from various countries. However, to the best of our knowledge, an international comparison between countries with diverse cultural and educational backgrounds has not been reported in the literature. The aim of this study was to compare the knowledge and attitudes towards HIV/AIDS of dental students of Kuwait University (KU), Kuwait and the University of Peradeniya (UP), Sri Lanka, the only dental schools in the respective countries. A cross-sectional survey was conducted among a total of 258 dental students, representing the clinical years of both universities, using a similar structured questionnaire with sixty questions to examine their knowledge of various aspects of HIV/AIDS and thirteen questions to examine their attitudes towards the disease. The mean knowledge and attitude scores were calculated and compared between students from the two universities using t-test with SPSS 17.0. A total of 215 questionnaires were completed and returned, giving a total response rate of 83.3 percent. The KU students were significantly more knowledgeable (p=0.018) regarding HIV/AIDS than the UP students. However, the UP students demonstrated a more highly significant positive attitude (p<0.001) towards the disease than those in KU. This information might help to define strategies to improve the quality of education in these countries.

Invasive candidiasis is associated with high morbidity and mortality. Clinical diagnosis is complicated by a lack of specific clinical signs and symptoms of disease. Laboratory diagnosis is also complex because circulating antibodies to Candida species may occur in normal individuals as the result of commensal colonization of mucosal surfaces thereby reducing the usefulness of antibody detection for the diagnosis of this disease. In addition, Candida species antigens are often rapidly cleared from the circulation so that antigen detection tests often lack the desired level of sensitivity. Microbiological confirmation is difficult because blood cultures can be negative in up to 50% of autopsy-proven cases of deep-seated candidiasis or may only become positive late in the infection. Positive cultures from urine or mucosal surfaces do not necessarily indicate invasive disease although can occur during systemic infection. Furthermore, differences in the virulence and in the susceptibility of the various Candida species to antifungal drugs make identification to the species level important for clinical management. Newer molecular biological tests have generated interest but are not yet standardized or readily available in most clinical laboratory settings nor have they been validated in large clinical trials. Laboratory surveillance of at-risk patients could result in earlier initiation of antifungal therapy if sensitive and specific diagnostic tests, which are also cost effective, become available. This review will compare diagnostic tests currently in use as well as those under development by describing their assets and limitations for the diagnosis of invasive candidiasis.

The increased incidence of oral candidiasis in patients with malignancies stems partly from the systemic disease itself and, partly from the therapeutic measures such as cytotoxic and other immunosuppressive drugs and radiotherapy they receive during management of such malignancies. In this review we discuss the clinical and laboratory findings on the relationship between cytotoxics, radiotherapy and oral candidiasis, possible mechanisms of pathogenicity following such therapy, as well as precautions that could be taken to minimize such recalcitrant yeast infections.