Dynamic analysis of oral Candida carriage, distribution, and antifungal susceptibility in HIV-infected patients during the first year of highly active antiretroviral therapy in Guangxi, China

Human immunodeficiency virus and oral microbiota: mutual influence on the establishment of a viral gingival reservoir in individuals under antiretroviral therapy

The role of the oral microbiota in the overall health and in systemic diseases has gained more importance in the recent years, mainly due to the systemic effects that are mediated by the chronic inflammation caused by oral diseases, such as periodontitis, through the microbial communities of the mouth. The chronic infection by the human immunodeficiency virus (HIV) interacts at the tissue level (e.g. gut, genital tract, brain) to create reservoirs; the modulation of the gut microbiota by HIV infection is a good example of these interactions. The purpose of the present review is to assess the state of knowledge on the oral microbiota (microbiome, mycobiome and virome) of HIV-infected patients in comparison to that of HIV-negative individuals and to discuss the reciprocal influence of HIV infection and oral microbiota in patients with periodontitis on the potential establishment of a viral gingival reservoir. The influence of different clinical and biological parameters are reviewed including age, immune and viral status, potent antiretroviral therapies, smoking, infection of the airway and viral coinfections, all factors that can modulate the oral microbiota during HIV infection. The analysis of the literature proposed in this review indicates that the comparisons of the available studies are difficult due to their great heterogeneity. However, some important findings emerge: (i) the oral microbiota is less influenced than that of the gut during HIV infection, although some recurrent changes in the microbiome are identified in many studies; (ii) severe immunosuppression is correlated with altered microbiota and potent antiretroviral therapies correct partially these modifications; (iii) periodontitis constitutes a major factor of dysbiosis, which is exacerbated in HIV-infected patients; its pathogenesis can be described as a reciprocal reinforcement of the two conditions, where the local dysbiosis present in the periodontal pocket leads to inflammation, bacterial translocation and destruction of the supporting tissues, which in turn enhances an inflammatory environment that perpetuates the periodontitis cycle. With the objective of curing viral reservoirs of HIV-infected patients in the future years, it appears important to develop further researches aimed at defining whether the inflamed gingiva can serve of viral reservoir in HIV-infected patients with periodontitis.

α-Mangostin and lawsone methyl ether in tooth gel synergistically increase its antimicrobial and antibiofilm formation effects in vitro

OBJECTIVES

α-Mangostin (α-MG) and lawsone methyl ether (LME) show antimicrobial and anti-biofilm activities. The objectives of this study were to develop a herbal tooth gel containing α-MG and LME plus fluoride and determine its antimicrobial, anti-biofilm formation, anti-cancer, anti-inflammatory, wound healing, and enamel microhardness effects.

METHODS

Antimicrobial assays against Streptococcus mutans, Porphyromonas gingivalis, and Candida albicans were performed. The microbes' ultrastructural morphology was assessed using Transmission Electron Microscopy. The effect on microbial biofilm formation was tested by a broth microdilution. Cell viability was assessed with MTT assay. The anti-inflammatory effect was investigated by measuring inhibition of nitric oxide production. Enamel microhardness was measured via Vickers microhardness testing. The enamel chemical composition was investigated with Fourier Transform Spectrometer. The enamel surface morphology and fluoride content were examined by Scanning Electron Microscopy and Energy Dispersive X-ray Spectroscopy.

RESULTS

The results show synergistic effects of α-MG and LME on antimicrobial activity and antibiofilm formation without cytotoxicity at a therapeutic dose. At a higher dose, the tooth gel inhibited proliferation of cancer cell line. Enamel microhardness was increased after brushing with the tooth gel plus fluoride. A large amount of fluoride was detected on the enamel surface.

CONCLUSION

The tooth gel containing α-MG and LME synergized its antimicrobial activity and antibiofilm formation and inhibited oral cancer cell proliferation. Incorporating fluoride into the tooth gel increased enamel microhardness. Thus, the herbal tooth gel containing α-MG and LME plus fluoride may be useful for preventing dental caries and promoting oral health.

Loop-mediated isothermal amplification for Candida species surveillance in under-resourced setting: a review of evidence

INTRODUCTION

Non-albicans Candida species (NACS) have emerged as a major public health burden although they are still underappreciated. Some NACS have intrinsic antifungal resistance, requiring constant surveillance to improve patient care and thwart outbreaks of recalcitrant candida infections. However, effective Candida species surveillance has relied on PCR-based or other high-end techniques that are largely unaffordable in under-resourced countries. Loop-mediated isothermal amplification (LAMP) has emerged as a potentially effective and affordable technique for infectious disease surveillance, especially in under resourced settings.

AREAS COVERED

We critically reviewed current literature on application of LAMP for Candida species identification in pure fungal isolates, and in clinical and non-clinical samples.

EXPERT OPINION

LAMP has been studied for Candida species identification, including the NACS. Besides a short turnaround time, LAMP has analytical sensitivity and specificity that are not only higher than culture method but also comparable with conventional and quantitative PCR techniques. However, extensive evaluation of LAMP for Candida species detection using various types of clinical and environmental samples are required before deploying the technique for Candida species surveillance.

Oral candidiasis in human immunodeficiency virus-infected patients under highly active antiretroviral therapy

Human immunodeficiency virus has plagued mankind since the 1980's when the first case was documented. Human immunodeficiency virus-induced immunocompromised state can lead to several systemic and local manifestations, which often culminates in mortality. Oral candidiasis was one of the most prevalent opportunistic infections noted in human immunodeficiency virus-infected patients. The advent of highly active antiretroviral therapy has led to a significant reduction in both the mortality and the morbidity of infected patients. The combined antiretroviral therapy has also led to a decrease in the incidence of opportunistic infections including oral candidiasis. Thus, the presence of well-established oral candidiasis in human immunodeficiency virus-infected patients under highly active antiretroviral therapy could be considered as an indicator of potential treatment failure. The present manuscript aims to review the published literature assessing the effect of highly active antiretroviral therapy on the incidence of oral candidiasis in human immunodeficiency virus-infected patients.

Oral mycobiome identification in atopic dermatitis, leukemia, and HIV patients - a systematic review

INTRODUCTION

Oral mycobiome profiling is important to understand host-pathogen interactions that occur in various diseases. Invasive fungal infections are particularly relevant for patients who have received chemotherapy and for those who have HIV infection. In addition, changes in fungal microbiota are associated with the worsening of chronic conditions like atopic dermatitis (AD). This work aims, through a systematic review, to analyze the methods used in previous studies to identify oral fungi and their most frequent species in patients with the following conditions: HIV infection, leukemia, and atopic dermatitis.

METHODS

A literature search was performed on several different databases. Inclusion criteria were: written in English or Portuguese; published between September 2009 and September 2019; analyzed oral fungi of HIV-infected, leukemia, or AD patients.

RESULTS

21 studies were included and the most identified species was Candida. The predominant methods of identification were morphological (13/21) and sugar fermentation and assimilation tests (11/21). Polymerase chain reaction (PCR) was the most used molecular method (8/21) followed by sequencing techniques (3/21).

CONCLUSIONS

Although morphological and biochemical tests are still used, they are associated with high-throughput sequencing techniques, due to their accuracy and time saving for profiling the predominant species in oral mycobiome.

Dynamic study of oral Candida infection and immune status in HIV infected patients during HAART

OBJECTIVE

To dynamically monitor oral Candida infection, CD4⁺ T lymphocyte counts, CD8⁺ T lymphocyte counts and CD4/CD8 ratios in HIV/AIDS patients during their first year of HAART and to preliminarily explore the relationships between them.

DESIGN

Forty-six patients with HIV/AIDS receiving HAART at the Infection Department of Chongqing Red Cross Hospital were followed for one year. At baseline and 3, 6, and 12 months after HAART initiation, oral rinses were collected and cultured to identify Candida species. Further, blood samples were collected to detect CD4⁺ T lymphocyte counts, CD8⁺ T lymphocyte counts and CD4/CD8 ratios.

RESULTS

The prevalence of OC decreased after HAART initiation (P ＜ 0.05), and Candida albicans was the dominant species isolated from the oral cavity (66/93). At 3, 6 and 12 months after HAART initiation, CD4⁺ T lymphocyte counts were 327.91 ± 138.82, 329.65 ± 142.66 and 319.98 ± 97.90 cells/mm³, respectively, which were significantly higher than the level at baseline (263.39 ± 126.01 cells/mm³) (P = 0.016, P = 0.014, and P = 0.035, respectively). During the first year of HAART, CD4/CD8 ratios increased gradually, and CD8⁺ T lymphocyte counts decreased continually. OC was associated with low CD4⁺ T lymphocyte counts and a low CD4/CD8 ratio. CD4⁺ T lymphocyte counts <200 cells/mm³ and Candida load ≥300 CFU/mL were risk factors for OC (P ＜ 0.05), and oral Candida load was negatively correlated with CD4⁺ T lymphocyte counts and the CD4/CD8 ratio.

CONCLUSION

OC might be a useful marker for the evaluation of immune status in patients with HIV/AIDS.

Oral manifestations, salivary flow rates and Candida species in Thai HIV-infected patients

Background

Effects of various Highly Active Antiretroviral Therapy (HAART) regimens on oral heath are unclear. Objectives: We aimed to evaluate effects of HAART on oral manifestations, salivary flow rates (SFR) and Candida species in HIV-infected patients who took mostly non-protease inhibitor-based HAART regimens.

Material and Methods

A cross-sectional study was performed on HIV-infected patients taking and never taken HAART who attended Thai Red Cross AIDS Research Centre (n = 48). Non-HIV subjects were recruited as control (n = 20). Oral conditions and salivary flow rates were evaluated using oral examination and measurement of unstimulated and stimulated saliva. In addition, Candida colonization counts (colony forming units; CFUs) and Candida species from the collected saliva were evaluated using CHROMagar.

Results

The most common oral manifestation in HIV-infected subjects taking HAART was hyperpigmentation. Unstimulated and stimulated SFR among the three groups were not statistically significant. Candida colonization was detected in 64%, 65% and 35% of HIV-infected subjects taking HAART, HAART-naïve, and non-HIV subjects, respectively. While 20% and 35% of HIV-infected subjects with and without HAART, respectively, had Candida CFUs higher than 500/ml, all non-HIV carriers had Candida CFUs lower than 500/ml. The most common Candida colonization species was C. albicans in HAART and non-HIV groups. Interestingly, HAART-naïve group was colonized more by non-albicans species.

Conclusions

HAART has minimal effects on oral health. While HAART may not prevent Candida colonization, it might lead to reduction of non-albicans species. Because maintaining low Candida counts is important, HAART administration and antifungal sensitivity test should be considered in HIV-infected patients. Key words:HIV, Candida, HAART, Oral manifestation, Salivary flow rates.

Salivary human beta-defensins affected by oral Candida status in Chinese HIV/AIDS patients undergoing ART

OBJECTIVES

To observe relationships between oral Candida status and salivary human beta-defensin 2 and 3 (hBD-2 and hBD-3) levels in HIV/AIDS patients of Guangxi, China during the first year of antiretroviral therapy (ART) dynamically, and to understand the influence of ART on oral Candida status and salivary hBDs expressions.

METHODS

A prospective self-controlled study was carried to observe the dynamic changes of CD4⁺ T cell counts, oral Candida carriages and salivary hBD-2,3 expressions in HIV/AIDS patients during the first year of ART. A total of 90 HIV/AIDS patients were enrolled and were examined at the baseline, 3rd, 6th, 12th month of ART. Thirty healthy individuals were enrolled as control. Peripheral blood, oral rinse sample, and unstimulated whole saliva were collected to test CD4⁺ T cell counts, oral Candida carriages, and hBD-2,3 expressions.

RESULTS

In the first year of ART, CD4⁺ T cell counts increased significantly. However, oral Candida carriages and oral candidiasis decreased significantly, and salivary hBD-2 expressions in HIV/AIDS patients decreased gradually, salivary hBD-3 levels were highly variable. Salivary hBD-2 concentrations were positively related to oral Candida carriages.

CONCLUSIONS

The incidence of oral candidiasis among HIV/AIDS patients gradually decreased due to the immune reconstruction of ART. Salivary defensins might play an important role in Candida-host interaction in HIV/AIDS patients.

Dynamic changes of Th1/Th2/Th17 cytokines and human beta defensin 2 in HIV-infected patients with oral candidiasis during the first year of highly active anti-retroviral therapy

OBJECTIVE

To investigate the change of Th1/Th2/Th17 cytokines and human beta defensin 2 (HBD-2) in HIV-infected patients with oral candidiasis (OC) and gather information about OC-specific immunity.

DESIGN

During the 1st year of highly active anti-retroviral therapy (HAART), 25 HIV-infected patients were followed up at the baseline, 3rd, 6th, 12th month. At each visit, oral manifestations were examined; oral rinses were collected and cultured for Candida; peripheral venous blood was taken to determine CD4 + T cell counts and HIV RNA viral load (VL); both unstimulated whole saliva and peripheral venous blood were taken to determine cytokine (IL-4, IL-17(A/F), IFN-γ) and HBD-2 levels. Twenty-five healthy individuals were enrolled as control.

RESULTS

HIV-infected patients displayed lower levels of IL-17(A/F) and IFN-γ but higher level of IL-4 and HBD-2 compared with healthy controls. During the 1st year of HAART, salivary IL-17(A/F) and IFN-γ were in uptrend, whereas salivary IL-4 and salivary HBD-2 were in downtrend. Serum cytokines all show no significant changes. After 1 year of HAART, serum, salivary IL-4 level and salivary IL-17(A/F) showed no significant difference from healthy controls. HIV-infected patients with OC had a higher IL-4 level but lower IFN-γ and IL-17(A/F) levels than those without OC since the 3rd month of HAART. The occurrence of OC was negatively correlated to IL-17(A/F) and IFN-γ, but positively correlated to IL-4. Salivary HBD-2 expression was up-regulated in HIV and might associate with Candida albicans.

CONCLUSIONS

In HIV-infected patients, the decrease of IL-17 and IFN-γ, and the increase of IL-4 in local and systemic level could influence the prevalence of OC. Salivary HBD-2 may also play an important role against OC.

Oral spray containing plant-derived compounds is effective against common oral pathogens

OBJECTIVES

Plant-derived compounds are a good source of therapeutic agents and inhibitors of inflammatory process. Dental caries, periodontal diseases and candidiasis are common oral infections caused by virulent biofilms. The objectives of this study were to develop oral spray containing plant-derived compounds; α-mangostin (α-MG) and/or lawsone methyl ether (2-methoxy-1,4-naphthoquinone) (LME) and determine its antimicrobial, anti-biofilm, and anti-inflammatory activities.

DESIGN

Oral spray formulations were prepared containing α-MG (5 mg/ml) and/or LME (250 μg/ml). Antimicrobial activity against Candida albicans, Streptococcus mutans, and Porphyromonas gingivalis and anti-biofilm formation activities were determined as well as cytotoxicity and anti-inflammatory effects.

RESULTS

The oral spray demonstrated antimicrobial activity against all three of the oral pathogens tested with stronger effects on C. albicans and S. mutans than P. gingivalis. The formulation containing α-MG (2.5 mg/ml) and LME (125 ug/ml) reduced growth of the microorganisms about 1-2 Log CFU/ml at 1-3 h and the killing effects were complete at 24 h. Based on biofilm assay, the oral spray containing both α-MG and LME showed greater inhibitory effects than those with α-MG or LME. In addition, the oral spray containing both α-MG and LME demonstrated more inhibition of nitric oxide production than α-MG alone. All the formulations were safe and demonstrated greater anti-inflammatory activity at lower concentration (<6.25 μg/ml) than at a higher concentration.

CONCLUSION

Oral spray containing α-MG and/or LME is effective against common oral pathogens without significant cytotoxicity. Thus, it has the potential to prevent the infections and may serve as adjunctive treatment to conventional therapy.

Oral mycoses and other opportunistic infections in HIV: therapy and emerging problems - a workshop report

Oral mycoses and other opportunistic infections are recognized features of HIV infection even after four decades of the epidemic. The therapeutic options, challenges of therapy, and evolving patterns of opportunistic infections were evaluated by the workshop. It was observed that high Candida counts and infection are still more prevalent in HIV-positive individuals even in the era of antiretroviral therapy. Furthermore, one or more non-Candida albicans are present in some HIV-positive individuals. While Candida species are more virulent in HIV infection, similar virulence may be present in other states of immunosuppression. Consequently, the interplay between host factors and virulence ultimately determines the clinical outcomes. Adverse clinical outcomes such as candidemia and other deep fungal infections are on the increase in HIV infection. Disseminated histoplasmosis and penicilliosis have been reported, especially with low CD4 counts. Even with advances in antifungal therapy, mortality and morbidity from deep fungal infections have not changed significantly. In addition, long-term exposure to common antifungal drugs such as fluconazole has led to the development of antifungal resistance in 6% to 36%. Development of new antifungal therapeutic agents and the use of alternative therapies may offer breakthrough. In addition, effective strategies to enhance the host immune status are being explored.