In vitro adhesion of oral candida dubliniensis isolates to acrylic denture surfaces following brief exposure to sub-cidal concentrations of polyenes, azoles and chlorhexidine

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. 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. 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. Brief exposure to sub-cidal concentrations of anti-mycotics suppressed the adhesion of C. dubliniensis oral isolates to acrylic denture surfaces

comparison of the antifungal activity of herbal toothpastes against other brands of toothpastes on clinical isolates of candida albicans and candida dubliniensis

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. 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. 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. The herbal toothpaste brand presented significant anticandidal activity over conventional toothpastes and may be useful in reducing the pathogenic potential of Candida species

Prevalence of Candida dubliniensis among oral Candida isolates in patients attending the Kuwait University Dental Clinic

The aim of this study was to determine the oral candidal carriage of patients seeking dental treatment at the Kuwait University Dental Clinic and to ascertain the Candida species composition among them. 370 oral rinse samples were collected from patients. The germ tube test, CHROMagar Candida medium and VITEK 2 yeast identification system were used for species identification. C. dubliniensis isolates were confirmed by the production of rough colonies with hyphal fringes and chlamydospores on simplified sunflower seed agar. Of the 370 samples investigated, 160 [43.24%] showed Candida in culture. The isolation of Candida was significantly higher in individuals who were smokers or were under medication for either diabetics or asthma [99 [62%]] compared to healthy individuals [61 [38%]]. Of the 210 samples which did not yield Candida, 131 [62.38%] were healthy and 79 [37.62%] were associated with smoking or with usage of drugs for aforementioned conditions. Species isolated were C. albicans [102 [63.7%]], C. dubliniensis [23[14.3%]], C. krusei [13 [8.1%]], C. tropicalis [12 [7.5%]] and C. glabrata [10 [6.2%]].Candida species were more prevalent in patients having predisposing factors implicated in oral candidosis, such as in smokers, diabetic patients and asthmatic patients using inhalation steroids. C. albicans was the most prevalent species isolated, followed by C. dubliniensis

Phenotypic and molecular characterization of candida dubliniensis isolates from clinical specimens in Kuwait

This study was carried out to characterize Candida dubliniensis using phenotypic and molecular methods and to determine the occurrence of C. dubliniensis in clinical specimens in Kuwait. A total of 880 clinical specimens for isolation of fungi were processed according to standard procedures. Of these, 390 germ-tube-positive clinical isolates of Candida species were examined for rough colonies with hyphal fringes and chlamydospore production on simplified sunflower seed agar for their presumptive phenotypicidentification as C. dubliniensis. The identification of C. dubliniensis isolates was further confirmed by the Vitek 2 yeast identification system, semi-nested [sn] PCR amplification of high-copy rDNA and direct DNA sequencing of the internally transcribed spacer 2 [ITS2] region. Of the 390 isolates of Candida species investigated, 12 were identified as C. dubliniensis, giving an overall occurrence of 3%. All the C. dubliniensis isolates formed rough colonies with hyphal fringes and abundant chlamydospores on sunflower seed agar, did not assimilate trehalose, lactate and alpha -methyl-D-glucoside, and were isolated from human immunodeficiency virus [HIV]-negative patients. Four C. dubliniensis isolates utilized D-xylose. The species-specific primer derived from the ITS2 sequence of C. dubliniensis and used together with the panfungal reverse primer in the reamplification step of the snPCR specifically amplified rDNA from reference and clinical C. dubliniensis isolates and not from C. albicans or other Candida species. The identity of two representative isolates was confirmed by DNA sequencing of the ITS2 region. The identity of 12 C. dubliniensis isolates was first established by phenotypic characteristics and then by snPCR using species-specific primers derived from ITS2 sequences. The recovery of C. dubliniensis from HIV-negative patients from Kuwait reinforces the existing view that this novel yeast species has a worldwide distribution and its occurrence is not restricted to any particular immunocompromised population

Diagnosis and therapy of invasive candida infections [Review Article]

To review the current status of diagnosis and treatment of invasive Candida infections. In recent years, Candida species have emerged as the fourth most frequent cause of nosocomial bloodstream infections, thus acquiring similar clinical significance as other familiar bacterial pathogens commonly associated with hospital-acquired sepsis. Despite growing clinical importance of Candida, a large number of patients die due to undiagnosed invasive candidiasis. With the current limitations of laboratory diagnostic tests, an understanding of the clinical setting or the risk factors in which a Candida species assumes the role of a destructive pathogen is extremely crucial for suspecting an early diagnosis. The information provided in this article has been obtained through Medline search and is largely based on the recommendations made by various expert groups on the subject. The diagnosis of invasive candidiasis is problematic due to the following reasons: [i] blood cultures may remain negative in about 50% of the patients with proven candidiasis, [ii] candidemia, a marker of dissemination, does not necessarily establish a disseminated disease, [iii] ophthalmologic examination is a valuable tool in diagnosing disseminated candidiasis but retinal lesions are found in less than 30% of candidemia patients and [iv] serologic tests lack sensitivity and specificity To improve isolation of Candida species from blood, use of Isolator lysis centrifugation method is recommended. Likewise, specificity and sensitivity of antigen detection in serum specimens can be enhanced by frequent sampling. All patients, even with a single positive blood culture, need to be treated with systemic antifungal therapy Amphotericin B is the standard drug for the treatment of invasive and disseminated candidiasis, particularly in neutropenic patients. 5-flucytosine in combination with amphotericin B is recommended for the treatment of severe Candida infections specially those associated with endophthalmitis, endocarditis, suppurative thrombophlebitis and meningitis, and also if the infection is caused by C. lusitaniae or C. glabrata. Liposomal formulations of amphotericin B, despite their decreased nephrotoxicity, have not been found to enhance therapeutic efficacy in clinical conditions. They should be used restrictively only for patients who are intolerant of or refractory to conventional amphotericin B therapy Fluconazole [400mg/d] is an effective and safe alternative to amphotericin B [0.5 -0.6mg/kg] for treatment of invasive candidiasis. Since the drug has excellent cerebrospinal penetration and is excreted unchanged through the kidneys, it is especially useful for the treatment of meningeal and genitourinary Candida infections. Considering its high safety profile, fluconazole can be selectively administered in much higher doses [>/= 600mg/day]. Until more sensitive and specific laboratory tests become available, an integrated approach based on blood cultures, serodiagnostic tests, and careful repeated clinical evaluation of the patients for evidence of hematogenous dissemination, should form the basis for the diagnosis of invasive and disseminated candidiasis. Early recognition of the risk factors with a high index of suspicion remains an integral component of the diagnostic approach

Changes in plasma electrolytes during acclimatisation at high altitude

The effects on plasma electrolytes and related hormones were determined in non-acclimatized low lander males, exposed for 96 hours to an altitude of 4424 meters. Twenty healthy soldiers aged 18-34 years travelled by road from an altitude of 2303 meters to 4424 meters over a period of 10 hours. Plasma sodium levels [142.09 +/- 1.14 mmol/l] and aldosterone [16.61 +/- 5.70 ng/ml] decreased to 139.69 mmol/l and 11.6 +/- 4.60 ug/mI respectively after 96 hours of acute expoure to high altitude [p<0.05]. The plasma potassium and chloride levels did not show significant change, while, plasma HCO3 decreased gradually from 21.06 +/- 1.38 mmol/l to 18.55 +/- 0.82 mmol/l after 96 hours exposure to this altitude [p<0.01]. The plasma ionized calcium and plasma phosphate concentration decreased from 1.32 +/- 0.11 mmol/l and 1.58 +/- 1.3 mmol/l to 1.20 +/- 0.05 mmol/l and 1.47 +/- 0.99 mmol/l respectively [p<0.05]. Plasma parathyroid hormone [PTH] level increased from 4.54 +/- 2.1 ng/ml to 11.19 +/- 4.31 ng/ml after 48 hours with subsequent decline to 2.52 +/- 1.7 ng/ml after 96 hours exposure to high altitude. It maybe concluded that the process of acclimatization to sudden exposure to high altitude is characterised by fall in plasma aldosterone and PTH with subsequent decrease of related electrolytes