Oral Yeast Colonization Research Articles

Exploring the diversityof uncommon oral yeast species andassociated risk factorsamong substance abusers insouthwestern Iran.

Yeast species are a group of coexistent microorganisms in the oral cavity that can cause opportunistic infections in vulnerable individuals, including addicts. This study aimed to identify the yeast species profile responsible for oral yeast colonization (OYC) and the associated risk factors in patients with substance use disorder (SUD) in Ahvaz, Iran. Oral samples were collected from drug users hospitalized in 12 addiction treatment centers, and the related clinical information was mined. Oral yeast species were identified using 21-plex PCR and sequencing of the internal transcribed spacer region (ITS1-5.8S-ITS2). A total of 244 yeast strains were identified from 245 individuals with substance abuse. Candida albicans was the most common species (37.7%) and non-albicans Candida was responsible for 57.7% of OYC, primarily C. dubliniensis (33.2%) and C. glabrata (11.9%). Moreover, uncommon oral yeasts constituted 5.3% of species, including Saccharomyces cerevisiae, Clavispora lusitaniae, Pichia kluyveri, Geotrichum candidum, Magnusiomyces capitatus, Hanseniospora opuntiae, Wickerhamomyces subpelliculosus, Trichosporon asahii, and Aureobasidium pullulans. Importantly, OYC exhibited associations with such factors as duration of drug use, daily drug consumption rate, opioid utilization, oral drug administration, and the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) score. The present study is the pioneering investigation revealing the prevalence and diversity of oral yeast species, along with associated risk factors, in individuals with SUD in southwestern Iran. Furthermore, it underscores the importance of developing efficient and cost-effective diagnostic methods tailored for resource-constrained settings.

Risk factors for malignant oral mucosal lesion development (literature review). Part 1. Endogenous and biological factors

Relevance. Oral mucosal cancer (OMC) is the sixteenth most common cancer worldwide. The high mortality rate is mainly due to the asymptomatic course of the disease in the early stages and late detection when the tumour process poorly responds to treatment. Determining the impact of various risk factors and establishing their relationship are necessary to prevent and diagnose malignant oral mucosal lesions in the early stages.Purpose. Based on the modern literature, the study aimed to determine the impact value of various internal and external risk factors on malignant oral mucosal lesion development and assess the risk factors’ relationship.Material and methods. The research material included the analysis of literature from databases – Elsevier, PubMed, Elibrary, Google Academy, Medline and Cyberleninka. The study included literature sources in Russian and English.Results. Based on modern literature, we have determined endogenous and biological risk factors for malignant oral mucosal lesion development. The study noted the high role of microbiome changes and the presence of dysbiosis in patients with malignant neoplasms and proved the direct involvement of Candida fungi in carcinogenesis. The development of oral mucosal cancer and the presence and severity of oral yeast colonization and human papillomavirus infection showed a positive correlation. Chronic oral diseases, which are susceptible to malignant transformation or contribute to the development of carcinomas, have been identified, and their relationship has been established with biological risk factors, age, sex of the patient and duration of the disease course.Conclusion. The studies considered in this part of the review prove the influence of endogenous and biological factors on the development of malignant neoplasms of the oral cavity and determine their relationship. However, many mechanisms remain unexplored to date. Effective primary and secondary prevention implementation needs improvement and the development of a multidisciplinary approach to research methodology, study the complex impact of all groups of risk factors on the development of malignant oral mucosal lesions.

P350 Oropharyngeal candidiasis in HIV infected patients: associated risk factors and antifungal susceptibility testing of candida species by disc diffusion method

Poster session 3, September 23, 2022, 12:30 PM - 1:30 PM ObjectivesTo isolate and identify Candida species by the standard microbiological method.To estimate the frequency of oral Candidiasis according to age, sex, and other factors [CD4 + count, ART, tobacco consumption, diabetes, upper respiratory tract infection (URTI), recent antibiotic consumption] in HIV-positive patients.To determine the Antifungal Susceptibility pattern of the Candida species by Disc Diffusion Method.MethodologyA hospital-based cross-sectional study was conducted for 6 months in the Department of Microbiology of Sukraraj Tropical and Infectious Disease Hospital, Kathmandu, Teku, Nepal. A total of 408 HIV-positive patients attending the ART center of the hospital of different age and sex were included in the study. Study variables like CD4 + count, tobacco consumption, diabetes, URTI, and recent antibiotic consumption were noted.Standard microbiological guidelines were followed for the oral swab collection and transportation. Specimen was seeded on SDA agar plates (SDA with chloramphenicol and cycloheximide). Preliminary identification of the Candida was done on the basis of colony characteristics, gram staining, and germ tube test. Further for the speciation of Candida species, HiCrome™ Candida Differential Agar (HImedia, India) was applied where on the basis of coloration and colony morphology speciation was done. Similarly, Cornmeal Agar (Dalmau plate culture technique) and sugar Fermentation test were applied to confirm the Candida species.Muller-Hinton agar supplemented with 2% glucose and 0.5 μg/ml methylene blue dye (GMB) medium was used to perform the antifungal susceptibility testing of Candida isolates. Antifungal susceptibility testing (AST) of isolates was performed and interpreted according to Clinical and Laboratory Standards Institute (CLSI) M44-A document. Candida albicans ATCC 90028 was taken as the reference strain. All the data were entered in Microsoft excel and Chi-square was used to find out the association between the frequency of oral candidiasis and study variables.ResultsAmong 408 studied subjects, 225 (55.1%) were males and 183 (44.9%) were females. Of the participants, 116 (28.4%) had regular tobacco smoking habit, diabetes 10 (2.5%), URTIs 30 (7.4%), antibiotic consumption 44 (10.8%) and ART use 394 (96.6%). The CD4 + cell count of respondents ranged from 12 - 2425 cells/mm³. Candida albicans 53 (81.5%) was the most frequently encountered species followed by C. tropicalis 3 (4.6%), C. krusei 2 (3.1%), C. glabrata 1 (1.5%) and 6 (9.2%) other Candida species. A total of 26 patients had CD4+ ≤200 cells/mm3 and 39 patients had CD4+ >200 cells/mm3. There was no significant association in the occurrence of oral candidiasis among males and females (P = .966), tobacco consumption (P = .051), ART use (P = .188), diabetes (P = .722). Whereas, there was a significant association between oral Candida carriage and CD4 + cell count ≤ 200 cells/mm3 (P <.001), URTI (P = .029), and recent antibiotic consumption (P = .002). Amphotericin B was the most potent antifungal followed by voriconazole, itraconazole, and conversely fluconazole the most resistant.Conclusion Candida albicans was the common species isolated in our study. Candida Chrome Agar can be used as a routine media for rapid identification and Candida speciation. AST needs to be done routinely to know the susceptibility pattern of isolates and initiate proper treatment of patients. Since oral yeast colonization was associated with low CD4 + count (<200 cells/mm3). Thus, oral lesions can serve as early markers for HIV infection.

Species Diversity and Antifungal Susceptibilities of Oral Yeasts from Patients with Head and Neck Cancer.

PurposeTo investigate the colonization and susceptibility to antifungal drugs of oral yeasts in head and neck cancer patients in Hainan, China.MethodsOral mucosa samples from 211 head and neck cancer patients were collected. Oral yeasts were isolated and identified to species by rDNA ITS sequencing. The susceptibilities of all yeasts to amphotericin B, fluconazole, fluorocytosine, itraconazole, and ketoconazole were determined.ResultsYeasts were isolated from 124 of the 211 oral swabs. The 124 yeast isolates were classified into following 10 species, from the most frequent to the least frequent, Candida albicans (53.2%), Candida tropicalis (22.6%), Candida krusei (6.5%), Kodamaea ohmeri (5.6%), Candida parapsilosis (4.8%), Hanseniaspora opuntiae (2.4%), Candida metapsilosis (1.6%), Pichia terricola (1.6%), Pichia norvegensis (0.8%), and Trichosporon asahii (0.8%). The overall frequencies of resistance among the yeasts to amphotericin B, fluconazole, flucytosine, itraconazole, and ketoconazole were 4.8%, 8.1%, 16.1%, 9.7%, and 9.7%, respectively. One C. albicans strain and one C. tropicalis strain were tolerant/resistant to all five drugs.ConclusionGiven the high prevalence of oral yeast colonization in head and neck cancer patients and the observed resistance of certain yeast isolates to the five antifungal drugs, our results suggest that rapid identification and susceptibility testing should be implemented before antifungal treatment is applied among patients with head and neck cancer in Hainan.

Oropharyngeal Candidiasis (OPC) in hiv infected patients and its antifungal susceptiblity pattern by disc diffusion method

Background: Oropharyngeal candidiasis (OPC) is an opportunistic fungal infection commonly found in Human Immunodeficiency Virus infected patients. Acquired Immunodeficiency syndrome a disease of human immune system caused by HIV, has emerged as a global crisis since its discovery in summer of 1981 in United States. The low absolute CD4+ T-lymphocyte count has traditionally been cited as the greatest risk factor for the development of OPC and current guidelines suggest increased risk once CD4+T-lymphocyte counts fall below 200 cells/mm3. Rampant, indiscriminate and long-term use of antifungals has led to the development of antifungal resistance among Candida species and hence the need of study. Methods and materials: A total of 408 Throat swab collected aseptically from patients using sterile cotton swab were seeded on Sabouraud's Dextrose Agar (SDA) and incubated at 37 °C. Any whitish, creamy, pasty colonies on SDA was suspected to be candida, gram staining and germ tube test was done for preliminary identification, further speciation was done based on colony morphology and color production on Candida Chrom Agar (HiMedia), pattern of blastoconida and chlamydospores on Cornmeal agar, and sugar fermentation test. Antifungal susceptibility testing (AST) of isolates was performed and interpreted according to Clinical and Laboratory Standards Institute (CLSI) M44-A document. Results: Among the 65 candida species isolated, Candida albicans 53 (81.5%), was the most common species followed by Candida tropicalis 3 (4.6%), Candida krusei 2 (3.1%), Candida glabrata 1 (1.5%) and 6 (9.2%) other Candida species. 26 patients had CD4+ ≤ 200 cells/mm3 and 39 patients had CD4+ ˃200 cells/mm3. There was a significant association between oral Candida carriage and CD4+ cell count ≤ 200 cells/mm3 (p < 0.001).Amphotericin B was the most potent antifungal followed by voriconazole, Itraconazole and conversely Fluconazole the most resistant. Conclusion: C. albicans was the common species isolated in our study. Candida Chrome Agar can be used as a routine media for rapid identification and candida speciation. AST needs to be done routinely to know the susceptibility pattern of isolates and initiate proper treatment of patients. Since Oral yeast colonization was associated with low CD4+ count (<200 cells/mm3). Thus oral lesion can serve as early marker for HIV infection.

Influence of delivery and feeding mode in oral fungi colonization - a systematic review.

Postnatal acquisition of microorganisms from maternal and environmental sources contributes to the child microbiome development. Several studies showed that the mode of delivery and breastfeeding may have impact on the oral bacterial colonization, however, the influence on oral fungal colonization is still unknown. We performed a systematic literature review on mother to child oral fungi transmission, namely regarding the association between the mode of delivery and breastfeeding in oral yeast colonization. Our analysis revealed no significant differences between the oral mycobiome of breastfed and bottle-fed children. As for the delivery mode, the majority of studies found a relation between fungal colonization and vaginal delivery. Candida albicans was the most commonly isolated fungi species. Our analysis suggests that maternal breastfeeding does not seem to influence oral mycology, but vaginal delivery appears to promote oral yeast colonization in early life.

Influence of dialysis therapies on oral health: a pilot study.

Chronic kidney disease (CKD) is a public health problem worldwide. Currently, the link between oral health status, dialysis modality, and dialysis vintage is still not clear. The aim of this study was to evaluate periodontal disease, dental caries, and Candida colonization among patients under hemodialysis (HD) therapy, peritoneal dialysis (PD) therapy, and PD with previous history of HD (HD/PD). The clinical history, smoking, and oral hygiene habits were recorded. Decayed, missing, or filled teeth (DMFT) index, Visible Plaque Index (VPI), clinical attachment level (CAL), bleeding on probing, saliva flow rate, saliva pH, and oral yeast colonization were assessed. HD/PD patients were generally submitted to longer periods of dialysis therapy than the other groups. The number of decayed and filled teeth did not differ between groups; HD patients presented a higher number of teeth, but poor periodontal status. Among the three groups, HD patients presented higher VPI, CAL, and oral Candida colonization, independently of the time under dialysis therapy. Candida albicans (HD and PD), Candida krusei (HD), and Candida carpophila (PD) were isolated in these patients. HD presented a more adverse impact on oral health than PD, particularly periodontal disease and oral Candida colonization; however, this impact on oral health appears to be reduced or ameliorated when patients change from HD to PD therapy.

Oral yeast colonization in patients with primary and secondary Sjögren's syndrome.

The study aimed to investigate the pattern of oral yeast colonization of Sjögren's syndrome patients and its correlation to salivary flow rates, age, and time of the disease progression. Saliva and swab specimens were obtained from 45 patients (primary Sjögren's syndrome=15/ secondary Sjögren's syndrome=15/ healthy controls=15). Yeast species were identified using culture method through chromogenic medium followed by polymerase chain reaction and Sanger sequencing. Eleven species from six different genera were detected. The most prevalent species found was Candida albicans followed by Candida tropicalis, Candida glabrata, Candida parapsilosis, and Candida krusei. Both groups of Sjögren's syndrome showed higher counts of C.albicans (Total and CFU counts) when compared to control group. In contrast, a greater variety of yeast species was identified on samples of the control group. This study showed that C.albicans is the most prevalent yeast, but also that a variety of other yeast species can colonize the oral cavity of Sjogren's syndrome patients. The identification of most of the colonies was not obtained by culturing-PCR methods combined.

Identification of uncommon oral yeasts from cancer patients by MALDI-TOF mass spectrometry

BackgroundOpportunistic infections due to Candida species occur frequently in cancer patients because of their inherent immunosuppression. The aim of the present study was to investigate the epidemiology of yeast species from the oral cavity of patients during treatment for oncological and haematological malignancies.MethodsMALDI-TOF was performed to identify yeasts isolated from the oral cavity of 350 cancer patients. Moreover, antifungal susceptibility testing was performed in according to CLSI guidelines (M27-A3).ResultsAmong 162 yeasts and yeast-like fungi isolated from the oral cavity of cancer patients, Candida albicans was the most common species (50.6%), followed by Candida glabrata (24.7%), Pichia kudriavzevii (Candida krusei (9.9%)), Candida tropicalis (4.3%), Candida dubliniensis (3.7%), Kluyveromyces marxianus (Candida kefyr (3.7%)) and Candida parapsilosis (1%). In addition, uncommon yeast species i.e., Saprochaete capitata, Saccharomyces cerevisiae, Clavispora lusitaniae (C. lusitaniae) and Pichia kluyveri (C. eremophila) were recovered from oral lesions. Oral colonization by C. albicans, non-albicans Candida species and uncommon yeasts were as follow; 55%, 44% and 1%, whereas oral infection due to C. albicans was 33.3%, non-albicans Candida species 60.6%, and uncommon yeasts 6.1%. Poor oral hygiene and xerostomia were identified as independent risk factors associated with oral yeast colonization. The overall resistance to fluconazole was 11.7% (19/162). Low MIC values were observed for anidulafungin for all Candida and uncommon yeast species.ConclusionsThis current study provides insight into the prevalence and susceptibility profiles of Candida species, including emerging Candida species and uncommon yeasts, isolated from the oral cavity of Iranian cancer patients. The incidence of oral candidiasis was higher amongst patients with hematological malignancies. The majority of oral infections were caused by non-albicans Candida species which were often more resistant to anti-fungal agents. Our findings suggest that anidulafungin should be used as antifungal of choice for prophylaxis in clinically high-risk patients with documented oral colonization or infection.

Oral Yeast Colonization and Fungal Infections in Peritoneal Dialysis Patients: A Pilot Study.

Peritonitis and exit-site infections are important complications in peritoneal dialysis (PD) patients that are occasionally caused by opportunistic fungi inhabiting distant body sites. In this study, the oral yeast colonization of PD patients and the antifungal susceptibility profile of the isolated yeasts were accessed and correlated with fungal infection episodes in the following 4 years. Saliva yeast colonization was accessed in 21 PD patients and 27 healthy controls by growth in CHROMagar-Candida® and 18S rRNA/ITS sequencing. PD patients presented a lower oral yeast prevalence when compared to controls, namely, Candida albicans. Other species were also isolated, Candida glabrata and Candida carpophila. The antifungal susceptibility profiles of these isolates revealed resistance to itraconazole, variable susceptibility to caspofungin, and higher MIC values of posaconazole compared to previous reports. The 4-year longitudinal evaluation of these patients revealed Candida parapsilosis and Candida zeylanoides as PD-related exit-site infectious agents, but no correlation was found with oral yeast colonization. This pilot study suggests that oral yeast colonization may represent a limited risk for fungal infection development in PD patients. Oral yeast isolates presented a variable antifungal susceptibility profile, which may suggest resistance to some second-line drugs, highlighting the importance of antifungal susceptibility assessment in the clinical practice.

Oral yeast colonization throughout pregnancy.

BackgroundRecent studies suggest that placenta may harbour a unique microbiome that may have origin in maternal oral microbiome. Although the major physiological and hormonal adjustments observed in pregnant women lead to biochemical and microbiological modifications of the oral environment, very few studies evaluated the changes suffered by the oral microbiota throughout pregnancy. So, the aim of our study was to evaluate oral yeast colonization throughout pregnancy and to compare it with non-pregnant women.Material and MethodsThe oral yeast colonization was assessed in saliva of 30 pregnant and non-pregnant women longitudinally over a 6-months period. Demographic information was collected, a non-invasive intra-oral examination was performed and saliva flow and pH were determined.ResultsPregnant and non-pregnant groups were similar regarding age and level of education. Saliva flow rate did not differ, but saliva pH was lower in pregnant than in non-pregnant women. Oral yeast prevalence was higher in pregnant than in non-pregnant women, either in the first or in the third trimester, but did not attain statistical significance. In individuals colonized with yeast, the total yeast quantification (Log10CFU/mL) increase from the 1st to the 3rd trimester in pregnant women, but not in non-pregnant women.ConclusionsPregnancy may favour oral yeast growth that may be associated with an acidic oral environment. Key words:Oral yeast, fungi, pregnancy, saliva pH.

Type 1 diabetes in children is not a predisposing factor for oral yeast colonization.

Type 1 diabetes mellitus (T1D) is considered a risk factor associated with oral yeast infections. The aim of this study was to evaluate the yeast oral carriage (in saliva and mucosal surface) of children with T1D and potential relation with host factors, particularly the subset of CD4+ T cells. Yeasts were quantified and identified in stimulated saliva and in cheek mucosal swabs of 133 diabetic T1D and 72 healthy control subjects. Salivary lymphocytes were quantified using flow cytometry. The presence of yeasts in the oral cavity (60% of total patients) was not affected by diabetes, metabolic control, duration of the disease, salivary flow rate or saliva buffer capacity, by age, sex, place of residence, number of daily meals, consumption of sweets or frequency of tooth brushing. Candida albicans was the most prevalent yeast species, but a higher number of yeast species was isolated in nondiabetics. T1D children with HbA1c ≤ 7.5 (metabolically controlled) presented higher number of CD4+ T salivary subsets when compared with the other groups of children (non-diabetic and nonmetabolically controlled) and also presented the highest number of individuals without oral yeast colonization. In conclusion, T1D does not predisposes for increased oral yeast colonization and a higher number of salivary CD4+T cells seems to result in the absence of oral colonization by yeasts.

Oral yeast colonization in peritoneal dialysis and hemodialysis patients and renal transplant recipients.

We aimed to investigate the frequency of oral yeast colonization (OYC) and the risk factors for patients who received continuous ambulatory peritoneal dialysis (CAPD) or hemodialysis (HD) or were renal transplant recipients (RTRs). The patients admitted to the Nephrology Clinic at Ataturk University Medical School from January through April 2013 were included in the study. A questionnaire about risk factors was filled out, and swab cultures were taken from the tongue surface of each participant. OYC was detected in 32.1% of the RTRs, 40% of the HD patients, 20.9% of the CAPD patients, and 18% of the healthy control (HC) group. Of the 42 yeast strains isolated from the renal replacement therapy groups, 26 strains (61.9%) were Candida albicans, nine (21.4%) were Candida glabrata, two (4.7%) were Candida krusei, two (4.7%) were Candida kefyr, one (2.38%) was Candida parapsilosis, and two (4.7%) were Geotrichum candidum. Risk factors for OYC in the RTRs group included antibiotic use and the presence of dental prostheses; however, in patients with chronic renal failure undergoing CAPD, only the presence of dental prostheses was found to be a statistically significant risk factor. Although OYC was mostly detected in patients with chronic kidney disease (undergoing HD, a variety of isolated yeast strains in the RTRs was noted. The rates of OYC and isolated Candida species in CAPD were similar to those of the HC group.

Oral Candida albicans and its correlation with caries in children in vivo

Background/objectivesCandida spp. has been detected in the mouths with extensive carious lesions in adults as well as children with variable frequency in different geographical areas. In this study we evaluated the prevalence of candida spp. in the oral cavity of children of central India with and without dental caries. Method and materialsChildren (3–12 years) were examined for decayed, missing and filled teeth (deft/DMFT) scores. Children (n-25) having ≤3 score made control group while those (n-25) having score ≥4 made experimental group. Mycological examination was conducted on the collected saliva sample of selected children. Oral yeast colonization was assessed by culturing Candida albicans on suitable broth. Collected data was then statistically analyzed. ResultsThe CFU/plate of candida in experimental group was statistically higher than in control group children. Spearman's rank correlation (rs = 0.643) showed linear relationship of CFU/plate with deft/DMFT scores. ConclusionThis study showed the active role of C. albicans in dental caries in children of 3–12 years of age group in Indore city of central India.

Hyposalivation, acidic saliva, decayed teeth and oral yeast prevalence in children with mucopolysaccharidosis

OBJECTIVE: Patients with mucopolysaccharidosis present several alterations of the stomatognathic complex, however, no data is available on saliva biochemistry and yeast colonization. The aim of the study was to evaluate caries experience as well as saliva biochemistry and microbiology parameters in patients with mucopolysaccharidosis. METHOD: The sample consisted of twelve participants with mucopolysaccharidosis followed in the Metabolic Disease Unit of the Centro Hospitalar de S. Joao and twelve healthy participants followed at the Faculty of Dental Medicine, University of Porto. To all participants, Decayed, Missing, Filled Teeth (DMFT) index was evaluated. In addition, saliva was collected to evaluate biochemical parameters (flow rate, pH, sodium, potassium, chloride, calcium, phosphate, α-amylase and IgA) and the microbiological profile (total microorganisms, mutans streptococci and yeasts) of all participants. RESULTS: In comparison to controls, the mucoplysacharidosis patients presented a higher prevalence of decayed teeth, lower salivary flow and pH values. They also presented also lower calcium and higher phosphate ions in saliva. No differences were found between groups regarding oral microbial load for total microorganisms, mutans streptococci and yeasts as well as oral prevalence of mutans streptococci. However, MPS patients presented higher prevalence of oral Candida in comparison to controls. CONCLUSION: The higher prevalence of decayed teeth and higher oral yeast colonization in MPS patients may be related to the lower saliva calcium concentration, pH and flow.

Yeast oropharyngeal colonization in human immunodeficiency virus-infected patients in central taiwan.

A prospective, cross-sectional study was conducted at a medical center in central Taiwan to understand the prevalence, associated factors, and microbiologic features for oropharyngeal yeast colonization in human immunodeficiency virus-infected outpatients. Oral yeast colonization was detected in 127 (45%) patients, including 21 (16.5%) colonized by more than one species. Of the 154 isolates, Candida albicans was the most common species (114, 74%), followed by Candida dubliniensis (10, 6.5%), Candida glabrata (10, 6.5%), Candida tropicalis (7, 4.5%), and 13 others. We found that receiving antituberculous drug (p=0.046) or atazanavir (p=0.045) was two predictors for patients colonized by non-C. albicans species (p=0.005) and risking mixed yeast colonization (p=0.009). Even though our data showed that clinical antifungal drugs remained effective in vitro against the colonizing yeasts, the increased mixed yeast colonization indicates a potential issue for controlling mixed infections in hospital settings.

Asymptomatic oral yeast carriage and antifungal susceptibility profile of HIV-infected patients in Kunming, Yunnan Province of China

BackgroundOral Candida colonization and its relation with predisposing factors in HIV-infected patients have received wide concerns during recent decades. In this study, we investigated asymptomatic oral Candida carriage rate, species distribution and antifungal susceptibility of 604 HIV-infected patients and 851 healthy individuals in Kunming, Yunnan Province of China.MethodsMucosal swab sampling was taken from each subject and CHROMagar Candida agar medium and API 20C AUX system were used to identify yeast isolates. In vitro antifungal susceptibility was tested by the broth microdilution method according to the M27-A2 document of the Clinical and Laboratory Standard Institute (CLSI).ResultsThe oral yeast colonization rate in HIV-infected patients (49.5%) was higher than that of healthy subjects (20.7%). Candida albicans constituted the most frequent species, accounting for 82.2% of yeast isolates. The remaining species were composed of C. glabrata, C. parapsilosis, C. krusei, C. tropicalis, C. rugosa, C. norvegensis, Pichia ohmeri and Saccharomyces cerevisiae. In HIV-infected patients, asymptomatic oral yeast colonization was associated with low CD4 cell count (<200 cells/mm3) and lack of highly active antiretroviral therapy (HAART). Different Candida species isolated from our samples presented different susceptibility to voriconazole, fluconazole and itraconazole. Amphotericin B had the best inhibiting effect for all isolates.ConclusionOral yeast colonization in Han Chinese patients with HIV from Kunming had common and unique features and was associated with CD4 cell number and HARRT. Amphotericin B should be used with first priority in controlling Candida infection in Han Chinese patients from Kunming. Our results provide first hand information on monitoring oral yeasts colonization in HIV-infected patients from Kunming, China.

Microbiology and epidemiology of oral yeast colonization in hemopoietic progenitor cell transplant recipients

We monitored the epidemiology and microbiology of oral yeast colonization in patients undergoing hemopoietic progenitor cell transplantation (HPCT) to examine associations between yeast colonization and oral mucositis. One hundred twenty-one consecutive HPCT patients were sampled for oral yeasts prior to fluconazole (FLC) prophylaxis, at transplantation, and weekly until discharge. Clinical oral mucositis screenings were performed triweekly. Yeast colonization was evident at 216 of 510 total visits. Candida albicans and Candida glabrata were the predominant organisms. Eight patients showed elevated minimal inhibitory concentrations to FLC. One patient developed fungal septicemia. Patients with oral mucositis assessment scale scores <20 had higher colonization rates than those with higher scores. FLC is effective in controlling a variety of oral yeasts in HPCT recipients. FLC-resistant yeasts do emerge and can be the source of fungal sepsis. A positive association was not shown between yeast colonization and the presence or severity of oral mucositis.

Oropharyngeal yeast colonization in HIV-infected outpatients in southern Taiwan: CD4 count, efavirenz therapy and intravenous drug use matter

To understand the status of oropharyngeal yeast colonization in human immunodeficiency virus (HIV) -infected outpatients in the era of highly active antiretroviral therapy (HAART), we conducted a prospective, cross-sectional study from October 2009 to January 2010 at a medical centre in southern Taiwan. Fungal cultures of the oropharyngeal swabs were performed on 327 enrolled patients. At enrolment, 258 (79%) patients had been receiving HAART, and 42 (12.8%), 73 (22.3%) and 212 (64.8%) patients had CD4 cell counts ≤200, 201–350, and >350 cells/mm3, respectively. Oral yeast colonization was detected in 193 (59%) patients, among whom 157 (81.3%), 25 (13.0%), and 11 (5.7%) were colonized by a single, two and more than two species, respectively. Multivariate analysis showed that receipt of efavirenz-containing regiments and CD4 cell counts >200 cells/mm3 were associated with lower risks of oral yeast colonization, while intravenous drug users were at a higher risk. Among the 241 isolates recovered, Candida albicans accounted for 69.7%, followed by C. dubliniensis (9.5%), C. glabrata (8.3%), C. tropicalis (3.3%), C. intermedia (2.1%), C. parapsilosis (1.7%), and 11 other species (5.4%). Overall, 230 (95.4%), 236 (97.9%) and 240 (99.6%) isolates were susceptible to fluconazole, voriconazole and amphotericin B, respectively. In conclusion, colonization by C. dubliniensis has emerged in recent years. In addition to a CD4 cell count ≤200 cells/mm3, which is a known risk factor for oropharyngeal yeast colonization in HIV-infected patients that was identified in our previous studies, two risk factors, non-receipt of efavirenz-based combinations and intravenous drug use, were first identified in the present study. Fluconazole remained effective in vitro against the yeasts colonizing the oropharynx in this population.

The Changing Epidemiology of Oropharyngeal Candidiasis in Patients with HIV/AIDS in the Era of Antiretroviral Therapy.

The impact of antiretroviral therapy (ART) on opportunistic conditions in HIV patients continues to evolve. We specifically studied the changing epidemiology of oropharyngeal candidiasis (OPC) in 215 HIV/AIDS patients. Status of yeast colonization was assessed from oral rinse samples, and preliminary yeast identification was made using CHROMagar Candida and confirmed with standard microbiological techniques and/or molecular sequencing. Susceptibility to fluconazole was determined by CHROMagar Candida agar dilution screening and CLSI broth microdilution. 176 (82%) patients were colonized and 59 (27%) patients had symptomatic OPC. Candida albicans was the most prevalent species, though C. glabrata and C. dubliniensis were detected in 29% of isolates. Decreased fluconazole susceptibility occurred in 10% of isolates. Previous ART reduced the risk of OPC, while smoking increased the risk of colonization. Oral yeast colonization and symptomatic infection remain common even with advances in HIV therapy. C. albicans is the most common species, but other yeasts are prevalent and may have decreased susceptibility to fluconazole.