Virulence of oral Candida isolated from HIV-positive women with oral candidiasis and asymptomatic carriers

Oral Candida albicans strain diversity and maintenance in HIV positive women in South Africa

OBJECTIVE

This study investigated C. albicans strain diversity and maintenance in the oral cavity of HIV positive women over a 6 month period.

STUDY DESIGN

C. albicans strains were isolated from 17 HIV positive women at Charlotte Maxeke Academic Hospital, Johannesburg at 3 intervals over a 6 month period. Strains were genotyped using ABC and Multilocus Sequence Typing (MLST) techniques. In the MLST technique, for each strain, a Diploid Sequence Type (DST) number was obtained. Using cluster analysis, an Unweighted Pair Group Method with Arithmetic Mean (UPGMA) dendrogram and a matrix of strain similarities were generated. Strains were also compared to the previous South African isolates documented in the MLST database.

RESULTS

Ninety four percent of women carried the same ABC genotype for 6 months. MLST technique, showed that ten women (58.8%) carried the same DST at 2 visits, while seven (41.2%) carried different DST at all visits. Further analysis showed that 64.7% of women were recolonised with different strains and 35.3% carried the same strains of C. albicans with heterozygosity. A total of 40 diploid sequence types were identified of which 27 DSTs were unique to this study group that were added to the MLST database. Most of the strains were closely related to previously isolated strains from South Africa.

CONCLUSION

Recolonization of the oral cavity with different strains and microevolution of the original strains of C. albicans can occur, which can be a potential problem for HIV patients, in whom highly virulent and drug resistant strains can emerge.

Prevalence of Oropharyngeal Candidiasis and distribution of Candida species among People Living with Human Immunodeficiency Virus in Africa: a systematic review and meta-analysis

Background

The incidence of oropharyngeal candidiasis among people living with human immunodeficiency virus in Africa is on the rise. Oropharyngeal candidiasis is mainly caused by C.albicans; however, a shift in the etiology towards non-Candida albicans species is increasing. In addition, there are variations in the epidemiological distribution of Candida species causing oropharyngeal candidiasis among people living with human immunodeficiency virus in Africa.

Objective

This review aimed to determine the prevalence of oropharyngeal candidiasis and the distribution of Candida species among people living with human immunodeficiency virus in Africa.

Materials and Methods

This systematic review protocol was registered in the base PROSPERO database prior to its conduct (CRD42021254473). The Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol guidelines (PRISMA-P) were followed for this study. The PubMed, Scopus and EMBASE databases were searched to identify published studies published between 1st January 2000 and 8th October 2022. The eligible studies were included in the meta-analysis and analyzed using a random effects model. The risk of bias of the included studies was assessed using the Joanna Briggs Institute quality assessment tool for prevalence studies.

Results

The database search yielded 370 titles from PubMed (n=192), EMBASE (n=162) and SCOPUS (n=16). Fourteen studies with a total of 3,863 participants were included in the meta-analysis. The pooled prevalence of oropharyngeal candidiasis was 49.0% (95% CI: 37% - 62%). A total of 2,688 Candida isolates were reported; approximately 76.6% (n=2,060) were C. albicans, and 21.7% (n=582) were non-C. albicans. Among the non-Candida albicans species, C. glabrata was the most common isolate (29.6%), followed by C. tropicalis (27.7%), C. krusei (17.0%), C. parapsilosis (8.1%) and C. dubliniensis (5.2%). Out of 14 studies, 7 (50.0%) had a low risk of bias, 5 (35.7%) had a moderate risk of bias, and 2 (14.3%) had a high risk of bias.

Conclusion

Almost half of people living with HIV in Africa have oropharyngeal candidiasis, and C. albicans remains the most frequent cause of oropharyngeal candidiasis.

Distribution and antifungal susceptibility profile of oropharyngeal Candida species isolated from people living with HIV in the era of universal test and treat policy in Uganda

Background

Despite the increased frequency of oropharyngeal candidiasis among people living with human immunodeficiency virus (HIV), its management is no longer effective due to empirical treatment and emergence of antifungal resistance (AFR). This study sought to investigate the prevalence of oropharyngeal candidiasis and assess the antifungal susceptibility profile of oropharyngeal Candida species isolated from people living with human immunodeficiency virus. Additionally, we evaluated the correlation between oropharyngeal candidiasis and CD4 T cell as well as viral load counts.

Methods

A descriptive cross-sectional study was carried out from April to October 2023 in which 384 people living with HIV underwent clinical examination for oral lesions. Oropharyngeal swabs were collected and cultured on Sabouraud Dextrose agar to isolate Candida species which were identified using the matrix assisted laser desorption ionization time of flight mass spectrometry. Additionally, the antifungal susceptibility profile of Candida isolates to six antifungal drugs was determined using VITEK® (Marcy-l'Étoile, France) compact system. Data on viral load were retrieved from records, and CD4 T cell count test was performed using Becton Dickinson Biosciences fluorescent antibody cell sorter presto.

Results

The prevalence of oropharyngeal candidiasis was 7.6%. Oropharyngeal candidiasis was significantly associated with low CD4 T cell count and high viral load. A total of 35 isolates were obtained out of which Candida albicans comprised of 20 (57.1%) while C. tropicalis and C. glabrata comprised 4 (11.4%) each. C. parapsilosis, C. dubliniensis and C. krusei accounted for 2 (5.7%) each. Additionally, 7 (20%) isolates were resistant to fluconazole, 1 (2.9%) to flucytocine and 0.2 (5.7%) isolates were intermediate to caspofungin. However, specific specie isolates like C. albicans showed 20% (4/20), C. glabrata 50% (2/4) and C. krusei 50% (1/2) resistance to fluconazole. Additionally, C. krusei showed 50% resistance to flucytosine.

Conclusion

The prevalence of oropharyngeal candidiasis (OPC) among people living with HIV was low, and there was a significant association between OPC and CD4 T cell count as well as viral load. C. albicans was the most frequently isolated oropharyngeal Candida species. C. glabrata and C. krusei exhibited the highest AFR among the non-albicans Candida species. The highest resistance was demonstrated to fluconazole.

Oral Cavity and Candida albicans: Colonisation to the Development of Infection

Candida colonisation of the oral cavity increases in immunocompromised individuals which leads to the development of oral candidiasis. In addition, host factors such as xerostomia, smoking, oral prostheses, dental caries, diabetes and cancer treatment accelerate the disease process. Candida albicans is the primary causative agent of this infection, owing to its ability to form biofilm and hyphae and to produce hydrolytic enzymes and candialysin. Although mucosal immunity is activated, from the time hyphae-associated toxin is formed by the colonising C. albicans cells, an increased number and virulence of this pathogenic organism collectively leads to infection. Prevention of the development of infection can be achieved by addressing the host physiological factors and habits. For maintenance of oral health, conventional oral hygiene products containing antimicrobial compounds, essential oils and phytochemicals can be considered, these products can maintain the low number of Candida in the oral cavity and reduce their virulence. Vulnerable patients should be educated in order to increase compliance.

Prevalence of oral lesions in patients with AIDS: a systematic review and meta-analysis

Background Oral lesions are considered to be early clinical signs which may predict the progression of patients with acquired immune deficiency syndrome (AIDS). Due to the lack of a comprehensive study that includes oral lesions in people with AIDS, the global prevalence of oral lesions in people with AIDS was estimated by combining preliminary studies' results using meta-analysis.Material and methods Databases including PubMed, Science Direct and Scopus were searched using keywords as 'HIV', 'AIDS', 'oral candidiasis', 'Kaposi Sarcoma', 'LinearGingival Erythema' and OR operators, AND and NOT. After the elimination of duplicate documents, articles that met the inclusion criteria were selected. Quality assessment was performed based on the Newcastle-Ottawa Scale. After combining the results of preliminary studies, an overall estimate of each lesion was reported. Ninety-five studies met the criteria for inclusion in this meta-analysis.Results The global prevalence of 21 oral lesions in HIV-infected patients was estimated. The overall prevalence of oral candidiasis, pseudomembranous candidiasis, oral hairy leukoplakia, Kaposi sarcoma and erythematous candidiasis was as follows: 35% (95% CI: 28-42), 19% (95% CI: 15-22), 12% (95% CI: 11-14), 5% (95% CI: 4-6) and 18% (95% CI: 14-22).Conclusion The present meta-analysis showed that oral lesions have a high prevalence in patients with AIDS. Dentists should consider that the clinical appearance of the oral cavity reflects the overall systemic health of the patient. As such, oral lesions may be linked to underlying immunosuppression caused by AIDS.

Oral colonization by Candida species and associated factors in HIV-infected patients in Ahvaz, southwest Iran

OBJECTIVES

Oropharyngeal candidiasis is one of the most common opportunistic fungal infections among human immunodeficiency virus (HIV)-infected individuals. The most common cause is Candida albicans, followed by non-albicans Candida. This study aimed to identify colonized Candida species in HIV-infected patients from Ahvaz, Iran. Additionally, the relationships between immunity-related factors, lifestyle, and colonization of Candida spp. were studied.

METHODS

Oral swabs were taken from 201 HIV-positive patients referred for consultations at the Behavioral Modification Center. Oral Candida colonization was detected using culture-based and molecular assays. Data were assessed by descriptive statistics and analyzed to investigate the correlation between Candida colonization and various factors, including the CD4⁺ cell count and viral load.

RESULTS

It was found that 43.8% of patients were positive for Candida. The most common species was C. albicans (48.0%), followed by non-albicans Candida isolates, including C. dubliniensis, C. glabrata, C. tropicalis, C. parapsilosis, C. guilliermondii, C. kefyr, and C. krusei. Colonization of Candida spp. in patients was associated with a CD4 count ≤200 cells/mm³ (odds ratio [OR], 4.62; p<0.05), history of shared injections (OR, 6.96; p<0.001), and sex (OR, 3.59; p<0.05).

CONCLUSIONS

The results of this study showed that C. albicans was the dominant pathogen. The risk factors for colonization of Candida spp. were a CD4 count ≤ 200/mm³ , a history of shared injections, and sex. Other factors with potential relationships include viral load, age, and opportunistic infections, but further investigations are needed.

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.

Oral colonization by Candida species in HIV-positive patients: association and antifungal susceptibility study

Objective

To investigate antifungal susceptibility and factors associated with oral colonization by Candida species in HIV-positive patients.

Methods

A prospective study based on convenience sampling of subjects recruited from a pool of confirmed HIV-positive individuals seen at a specialty outpatient service in Rondonópolis, Mato Grosso, Brazil). Oral swabs were collected from 197 patients. Candida species were identified by standard microbiological techniques (phenotypic and molecular methods). Antifungal susceptibility was investigated using the broth microdilution method.

Results

A total of 101 (51.3%) patients were Candida spp carriers. Candida albicans was the most prevalent species (80%). Patients aged 45 to 59 years (Prevalence ratios: 1.90; 95%CI: 1.57-6.31) and 60 years or older (Prevalence ratios: 4.43; 95%CI: 1.57-34.18) were at higher risk of oral colonization by Candida species. Resistance to fluconazole and ketoconazole, or to itraconazole, corresponded to 1% and 4%, respectively.

Conclusion

Age (45 years or older) was the only factor associated with oral colonization by Candida . Low rates of antifungal resistance to azoles were detected in yeast isolates obtained from HIV-positive patients. Findings of this study may contribute to proper therapeutic selection for oral candidiasis in HIV-positive patients.

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.

Oral candidiasis among African human immunodeficiency virus-infected individuals: 10 years of systematic review and meta-analysis from sub-Saharan Africa

Oral candidiasis (OC) is the most common opportunistic fungal infection among immunocompromised individuals. This systematic review and meta-analysis reports on the contribution of non-albicans Candida species in causing OC among human immunodeficiency virus (HIV)-infected individuals in sub-Saharan Africa between 2005 and 2015. Thirteen original research articles on oral Candida infection/colonization among HIV-infected African populations were reviewed. The prevalence of OC ranged from 7.6% to 75.3%. Pseudomembranous candidiasis was found to range from 12.1% to 66.7%. The prevalence of non-albicans Candida species causing OC was 33.5% [95% confidence interval (CI) 30.9–36.39%]. Of 458 non-albicans Candida species detected, C. glabrata (23.8%; 109/458) was the most common, followed by C. tropicalis (22%; 101/458) and C. krusei (10.7%; 49/458). The overall fluconazole resistance was 39.3% (95% CI 34.4–44.1%). Candida albicans was significantly more resistant than non-albicans Candida species to fluconazole (44.7% vs 21.9%; p < 0.001). One-quarter of the cases of OC among HIV-infected individuals in sub-Saharan Africa were due to non-albicans Candida species. Candida albicans isolates were more resistant than the non-albicans Candida species to fluconazole and voriconazole. Strengthening the capacity for fungal diagnosis and antifungal susceptibility testing in sub-Saharan Africa is mandatory in order to track the azole resistance trend.

Clinical Appearance of Oral Candida Infection and Therapeutic Strategies

Candida species present both as commensals and opportunistic pathogens of the oral cavity. For decades, it has enthralled the clinicians to investigate its pathogenicity and to improvise newer therapeutic regimens based on the updated molecular research. Candida is readily isolated from the oral cavity, but simple carriage does not predictably result in development of an infection. Whether it remains as a commensal, or transmutes into a pathogen, is usually determined by pre-existing or associated variations in the host immune system. The candida infections may range from non-life threatening superficial mucocutaneous disorders to invasive disseminated disease involving multiple organs. In fact, with the increase in number of AIDS cases, there is a resurgence of less common forms of oral candida infections. The treatment after confirmation of the diagnosis should include recognizing and eliminating the underlying causes such as ill-fitting oral appliances, history of medications (antibiotics, corticosteroids, etc.), immunological and endocrine disorders, nutritional deficiency states and prolonged hospitalization. Treatment with appropriate topical antifungal agents such as amphotericin, nystatin, or miconazole usually resolves the symptoms of superficial infection. Occasionally, administration of systemic antifungal agents may be necessary in immunocompromised patients, the selection of which should be based upon history of recent azole exposure, a history of intolerance to an antifungal agent, the dominant Candida species and current susceptibility data.

Influence of cancer treatment on the Candida albicans isolated from the oral cavities of cancer patients

PURPOSE

Cancer treatment causes mucositis and the manifestation of oral candidiasis. This study investigated the virulence properties and antifungal susceptibilities of Candida albicans isolated from cancer patients undergoing therapy.

METHODS

C. albicans were isolated from 49 patients on cancer treatment and 21 healthy individuals and their virulence attributes measured. A correlation was determined between the length of treatment and the fungal counts and their virulence factors.

RESULTS

Although Candida carriage was similar in all the study groups, high quantities of C. albicans and variety of Candida were found in cancer patients. Germ tubes were produced by all the strains. Significantly high number of yeast isolated from radiotherapy and chemotherapy produced large quantities of phospholipase compared to healthy individuals (p < 0.01). The length of chemotherapy was associated with an increase in the phospholipase production (p = 0.03) by the C. albicans. Proteinase production was seen in a significant number of isolates from the radiotherapy group (p < 0.01). Type of cancer treatment had no effect. Resistance to antifungal agents was low.

CONCLUSIONS

High quantities of phospholipase were produced by C. albicans in cancer patients on therapy which also increased with the length of chemotherapy suggesting enhanced risk of oral and systemic infection. Therefore, during treatment, prophylactic topical antifungal therapy may be considered.

Oral health and HIV infection among female sex workers in Abidjan, Côte d'Ivoire

BACKGROUND

Worldwide, female sex workers (FSW) represent a vulnerable population for oral diseases due to many risk factors including HIV infection and drug abuse. In sub-Saharan Africa, little is known about the burden of oral diseases and their determinants in vulnerable populations. The aim of the study was to estimate the prevalence and associated factors of oral diseases among FSW.

METHODS

A cross sectional study was conducted among FSW who attended a dedicated non-profit clinic in Abidjan, Côte d'Ivoire from June to August 2013. Data about the presence of dental caries, periodontitis and oral-mucosal lesions were collected by a dentist during an oral examination. Behavioural information related to oral hygiene habits as well as tobacco and alcohol consumption were collected through a standardized questionnaire. Information related to HIV infection including HIV diagnosis, last known CD4 count and antiretroviral therapy were documented through a medical chart review. Logistic regression models were used to identify factors associated with oral diseases.

RESULTS

A total of 249 FSW with a median age of 29 years, [Inter Quartile Range (IQR) = 23-36] and a median duration of sex work of 24 months [IQR 9-60]) were included. Current tobacco use and hazardous alcohol use were reported in 21.7 % and 19.7 % of FSW, respectively. The estimated prevalence of HIV infection was 33.7 % [95 % confidence interval (CI); 27.8 - 39.6]) and 82.1 % of HIV-infected FSW were on antiretroviral therapy . The prevalence of dental caries, periodontitis and oral-mucosal lesions were 62.3 % [95 % CI 55.5 - 67.5], 14.5 % [95 % CI 10.2 - 18.9] and 8.2 % [95 % CI 4.8 - 11.5], respectively. In multivariate analysis, periodontitis, oral-mucosal lesions and HIV infection were associated with odds ratio of 2.6 [95 % CI, 1.2-5.8]) and 50.0 [95 % CI; 6.4-384.6].

CONCLUSIONS

This study showed a high prevalence of oral diseases among FSW in Abidjan. HIV infection was common and significantly associated with periodontal diseases and oral-mucosal lesions. There is a need to integrate regular screening and treatment of oral lesions into the medical follow-up of FSW along with strategies for HIV prevention.

Oral carriage of Candida species in HIV-infected patients during highly active antiretroviral therapy (HAART) in Belém, Brazil

OBJECTIVE

To identify the oral carriage of Candida spp in patients infected by human immunodeficiency virus (HIV) and the possible correlation with clinical characteristics.

STUDY DESIGN

Mucosal swab samples collected from 246 patients who were infected by HIV, did not have oral candidiasis, and were being treated with highly active antiretroviral therapy were analyzed. Yeast colonies that developed were identified by using the VITEK 2 automated system.

RESULTS

Candida yeasts were present in 41.87% of the samples, and Candida albicans was the most prevalent (32.52%). Other identified Candida species were C tropicalis (4.88%), C parapsilosis (2.85%), C dubliniensis (0.81%), and C famata (0.81%).

CONCLUSIONS

There was low rate of oral Candida carriage in patients infected by HIV who were on highly active antiretroviral therapy. A greater prevalence of C albicans than non-albicans Candida species was found at the species level. Prior candidiasis predicted the oral carriage of C albicans; however, it did not influence the carriage of non-albicans species. This is the first report of oral carriage of C famata in patients with HIV infection.