Oral candidiasis of HIV-infected children undergoing sequential HIV therapies

Impact of Antiretroviral Therapy on Oral Health among Children Living with HIV: A Systematic Review and Meta-Analysis

Oral health is an integral component of general health and well-being but might be undermined among children living with HIV (CLWH) due to the condition itself or the antiretroviral therapy (ART) received. This review summarises the current evidence and compares the oral health status of the CLWH who were treatment-naïve with those undergoing different ART medications. Fourteen studies were included in the final qualitative and quantitative analyses. This review identified no significant difference in the prevalence of caries, periodontal conditions, and tooth development between both groups. Orofacial opportunistic infections were more prevalent in the CLWH without ART. Children undergoing ART with a duration longer than 3 years had a significantly lower prevalence of oral candidiasis and CD4+ T-cell counts. However, due to the insufficient number of well-administered case-control studies with adequate sample size, the quality of the evidence in all outcomes was of very low certainty.

White-to-opaque switching is involved in the phospholipase B production of Candida dubliniensis on Price's egg yolk agar

Measuring the production of Candida dubliniensis (C. dubliniensis) phospholipase B (PLase B) by the Price's method has long been considered to be unattainable because the levels of PLase produced are undetectable. In this study, C. dubliniensis, C. glabrata, C. guilliermondii, C. krusei, C. parapsilosis and C. tropicalis were shown to produce PLase B and form clear white zones around their colonies when peptone, a component of the original Price's egg yolk (OP) agar, is replaced with a yeast nitrogen base (YNB). This new medium is named modified Price's (MP) agar. Based on this finding, we propose a new modified Price's (NMP) agar containing 0.75% peptone and 0.25% YNB, which enabled measurement of PLase B production by C. dubliniensis and C. albicans with results consistent with those obtained for C. albicans grown on OP agar. We strongly believe that the MP and NMP agars are very useful for screening PLase B production by C. dubliniensis and non-albicans Candida spp. Moreover, the addition of several bioactive agents (the proteinase inhibitors pepstatin A and saquinavir, the calcineurin inhibitors cyclosporine A and tacrolimus, the cell-permeable cAMP analog dBcAMP, and the quorum-sensing molecule farnesol) to the OP agar enhanced PLase B production by C. dubliniensis. During the course of our study to clarify the reason why PLase B was not produced, we found that C. dubliniensis cells grown on OP agar undergo a white-to-opaque transition, which may explain why they showed minimal production of PLase B on this medium.

Prevalence of oral candidiasis in HIV/AIDS children in highly active antiretroviral therapy era. A literature analysis

SummaryHighly active antiretroviral therapy has decreased the morbidity and mortality related to HIV infection, including oral opportunistic infections. This paper offers an analysis of the scientific literature on the epidemiological aspects of oral candidiasis in HIV-positive children in the combination antiretroviral therapy era. An electronic databases search was made covering the highly active antiretroviral therapy era (1998 onwards). The terms used were oral lesions, oral candidiasis and their combination with highly active antiretroviral therapy and HIV/AIDS children. The following data were collected from each paper: year and country in which the investigation was conducted, antiretroviral treatment, oral candidiasis prevalence and diagnostic parameters (clinical or microbiological). Prevalence of oral candidiasis varied from 2.9% in American HIV-positive children undergoing highly active antiretroviral therapy to 88% in Chilean HIV-positive children without antiretroviral therapy. With respect to geographical location and antiretroviral treatment, higher oral candidiasis prevalence in HIV-positive children on combination antiretroviral therapy/antiretroviral therapy was reported in African children (79.1%) followed by 45.9% reported in Hindu children. In HIV-positive Chilean children on no antiretroviral therapy, high oral candidiasis prevalence was reported (88%) followed by Nigerian children (80%). Oral candidiasis is still frequent in HIV-positive children in the highly active antiretroviral therapy era irrespective of geographical location, race and use of antiretroviral therapy.

Clinical pharmacology of antifungal agents to overcome drug resistance in pediatric patients

INTRODUCTION

Antifungal resistance is an emerging problem that increases morbidity and mortality in immunosuppressed pediatric patients, who suffer from invasive fungal diseases. Optimal pharmacological management is critical for the successful treatment of invasive fungal infections by resistant strains.

AREAS COVERED

This paper reviews the mechanisms of resistance of different classes of antifungal agents and the current understanding of pediatric antifungal pharmacology for overcoming antifungal resistance in children based on laboratory and clinical studies in the English literature. The therapeutic choices against fungal pathogens with intrinsic or acquired resistance are further reviewed.

EXPERT OPINION

There is a paucity of data in the pediatric population regarding the epidemiology of the resistant organisms to different antifungal agents. It is also unknown if there are more prevalent molecular mechanisms that promote antifungal resistance. Selection and dosages of the most effective antifungal agent for overcoming the antifungal resistance is crucial. However, there are limited studies guiding the optimal dosage and duration of treatment for management of emergent antifungal resistance. Further studies are warranted to elucidate the optimal pharmacology of the current antifungal agents against resistant organisms and to advance the development of new antifungal agents.

Paediatric oropharyngeal and cutaneous candidiasis with special reference to Candida dubliniensis

Mucocutaneous and cutaneous candidiasis, though common in children, is often under-reported. The prevalence of Candida dubliniensis in causing these infections in this age group is also largely unknown. A prospective epidemiological cross-sectional study for candidiasis was performed in paediatric patients clinically suspected of candidiasis with oropharyngeal lesions (75 patients), cutaneous lesions (18 patients) and lesions at both sites (2 patients). Candida species were identified by conventional tests. For C. dubliniensis, chlamydospore production, growth on tobacco agar and growth at 45 °C were performed. Nine isolates were confirmed at a reference centre. The rates of candidiasis were 77.3 % (58 out of 75 patients clinically suspected of candidiasis) and 83.3 % (15/18) in oropharyngeal and cutaneous lesions respectively, and 1 of the 2 children with lesions at both sites was diagnosed as having chronic mucocutaneous candidiasis due to C. dubliniensis. The commonest species isolated was Candida albicans, in 41 (70.7 %) patients with oropharyngeal candidiasis and 11 (73.3 %) with cutaneous lesions; C. dubliniensis was isolated from 11 and 3 children respectively. In the paediatric population, C. albicans predominates in mucocutaneous and cutaneous candidiasis, with C. dubliniensis also contributing substantially.

Myriocin significantly increases the mortality of a non-mammalian model host during Candida pathogenesis

Candida albicans is a major human pathogen whose treatment is challenging due to antifungal drug toxicity, drug resistance and paucity of antifungal agents available. Myrocin (MYR) inhibits sphingosine synthesis, a precursor of sphingolipids, an important cell membrane and signaling molecule component. MYR also has dual immune suppressive and antifungal properties, potentially modulating mammalian immunity and simultaneously reducing fungal infection risk. Wax moth (Galleria mellonella) larvae, alternatives to mice, were used to establish if MYR suppressed insect immunity and increased survival of C. albicans-infected insects. MYR effects were studied in vivo and in vitro, and compared alone and combined with those of approved antifungal drugs, fluconazole (FLC) and amphotericin B (AMPH). Insect immune defenses failed to inhibit C. albicans with high mortalities. In insects pretreated with the drug followed by C. albicans inoculation, MYR+C. albicans significantly increased mortality to 93% from 67% with C. albicans alone 48 h post-infection whilst AMPH+C. albicans and FLC+C. albicans only showed 26% and 0% mortalities, respectively. MYR combinations with other antifungal drugs in vivo also enhanced larval mortalities, contrasting the synergistic antifungal effect of the MYR+AMPH combination in vitro. MYR treatment influenced immunity and stress management gene expression during C. albicans pathogenesis, modulating transcripts putatively associated with signal transduction/regulation of cytokines, I-kappaB kinase/NF-kappaB cascade, G-protein coupled receptor and inflammation. In contrast, all stress management gene expression was down-regulated in FLC and AMPH pretreated C. albicans -infected insects. Results are discussed with their implications for clinical use of MYR to treat sphingolipid-associated disorders.

Oral colonization by yeasts in HIV-positive patients in Brazil

INTRODUCTION: In HIV-infected patients, colonization of the oral cavity by potential pathogenic yeast may lead to development of systemic fungemia. We evaluated the prevalence of yeast in the oral cavity of Brazilian HIV-positive patients and verified whether or not the species characterized were enzymatically active. Furthermore, the species identified were tested for their susceptibility to antifungal treatment. METHODS: Patient saliva and oropharyngeal candidiasis samples were collected from 60 seropositive HIV patients and identified by the API20C system. Enzymatic activity was evaluated by the production of proteinase and phospholipase. Susceptibility to antifungal treatments were determined using the broth microdilution method. RESULTS: the most commonly isolated species were C. albicans (51.56%) followed by non-albicans Candida species (43.73%), Trichosporon mucoides (3.12%) and Kodamaea ohmeri (1.56%). Oral colonization by association of different species was observed in 42% of the patients. Enzymatic activity was verified in most of species isolated, except for C. glabrata, C. lusitaniae and C. guilliermondii. Resistance to Fluconazole and Amphotericin B was observed in isolates of C. albicans, C. glabrata, C. parapsilosis, C. krusei, and K. ohmeri. CONCLUSION: HIV-positive patients are orally colonized by single or multiple species of yeast that are occasionally resistant to Fluconazole or Amphotericin B.

Distribution of yeast species associated with oral lesions in HIV-infected patients in Southwest Uganda

Oropharyngeal candidiasis remains a significant clinical problem in HIV-infected and AIDS patients in regions of Africa where anti-retroviral therapy isn't readily available. In this study we identified the yeast populations associated with oral lesions in HIV-infected patients in Southwest Uganda who were receiving treatment with nystatin and topical clotrimazole. Samples were taken from 605 patients and 316 (52%) of these yielded yeast growth following incubation on Sabouraud dextrose agar. Samples were subsequently re-plated on CHROMagar Candida medium to facilitate identification of the yeast species present. The majority (56%) of culture-positive samples yielded a mix of two or more species. Candida albicans was present in 87% (274/316) of patient samples and accounted for 87% (120/138) of single species samples. Candida glabrata, Candida tropicalis and Candida norvegensis were also found in cultures that yielded a single species. No Candida dubliniensis isolates were identified in this population.

Formulation and Evaluation of in situ Gels Containing Clotrimazole for Oral Candidiasis

Gel dosage forms are successfully used as drug delivery systems to control drug release and protect the medicaments from a hostile environment. The main objective is to formulate and evaluate in situ oral topical gels of clotrimazole based on the concept of pH triggered and ion activated systems. The system utilizes polymers that exhibit sol-to-gel phase transition due to change in specific physico-chemical parameters. A pH triggered system consisting of carbopol 934P (0.2-1.4% w/v) and ion triggered system using gellan gum (0.1-0.75% w/v) along with hydroxylpropylmethylcelluose E50LV was used to prolong the release of clotrimazole (0.1% w/v). Formulations were evaluated for gelling capacity, viscosity, gel strength, bioadhesive force, spreadability, microbiological studies and in vitro release. The use of carbopol as in situ gel forming system was substantiated by the property to transform into stiff gels when the pH was raised, whereas in gellan gum this transformation occurred in the presence of monovalent/divalent cations. Effect of calcium carbonate and other process parameters optimized and found that increase in calcium ions produced stronger gels. The drug content, clarity, and pH of the formulation were found to be satisfactory. The viscosity was found to be in the range 5 to 85 centipoise for the sol, whereas for the gels it was up to 16000 centipoise. The formulation showed pseudoplastic flow with thixotrophy. The maximum gel strength (using texture analyzer) and bioadhesion was found to be up to 6.5 g and 4 g, respectively. The optimized formulations were able to release the drug up to 6 h. The formulation containing gellan gum showed better sustained release compared to carbopol based gels.