Oral Candida spp carriers: its prevalence in patients with type 2 diabetes mellitus

Carbon substrates promotes stress resistance and drug tolerance in clinical isolates of Candida tropicalis

Candida tropicalis is a human pathogen and one of the most prevalent non-Candida albicans Candida (NCAC) species causing invasive infections. Azole antifungal resistance in C. tropicalis is also gradually increasing with the increasing incidence of infections. The pathogenic success of C. tropicalis depends on its effective response in the host microenvironment. To become a successful pathogen, cellular metabolism, and physiological status determine the ability of the pathogen to counter diverse stresses inside the host. However, to date, limited knowledge is available on the impact of carbon substrate metabolism on stress adaptation and azole resistance in C. tropicalis. In this study, we determined the impact of glucose, fructose, and sucrose as the sole carbon source on the fluconazole resistance and osmotic (NaCl), oxidative (H2O2) stress adaptation in C. tropicalis clinical isolates. We confirmed that the abundance of carbon substrates influences or increases drug resistance and osmotic and oxidative stress tolerance in C. tropicalis. Additionally, both azole-resistant and susceptible isolates showed similar stress adaptation phenotypes, confirming the equal efficiency of becoming successful pathogens irrespective of drug susceptibility profile. To the best of our knowledge, our study is the first on C. tropicalis to demonstrate the direct relation between carbon substrate metabolism and stress tolerance or drug resistance.

Do Long-Term Complications of Type 2 Diabetes Increase Susceptibility to Geriatric Syndromes in Older Adults?

Background and Objectives: Type 2 diabetes is one of the common chronic diseases in the elderly. It is thought that long-term complications of type 2 diabetes will negatively affect the quality of life in elderly individuals. It is possible that geriatric syndromes, especially frailty syndrome, are associated with diabetic complications, too. In this study, we aimed to evaluate the effect of macrovascular and microvascular complications of type 2 diabetes on frailty and other geriatric syndromes. In addition, the effect of these complications on quality of life was also reviewed. Materials and Methods: We conducted a cross-sectional study for four months. Comprehensive geriatric assessment tests were done on all patients. The Fried frailty index (FFI) was used for the evaluation of frailty syndrome. We assessed malnutrition by mini nutritional assessment short-form (MNA-SF), and Global Leadership Initiative on Malnutrition criteria (GLIM). The EWGSOP 2 criteria were used for the diagnosis of sarcopenia. Quality of life (QoL) was evaluated using the short form-36 (SF-36) questionnaire. Data analysis was done by SPSS version 22. Results: 237 females and 142 males with a mean age of 71.7 ± 6.1 years were included in the study. The frequency of macrovascular and microvascular complications was 41.4% and 68.1%, respectively. Frailty was found to be associated with macrovascular complications (p = 0.003). Handgrip strength, skeletal muscle mass index, and gait speed were decreased in the presence of macrovascular complications (p = 0.043, p < 0.001, p < 0.001). QoL was also decreased in patients with macrovascular complications (p = 0.003). Nutritional status and handgrip strength were negatively affected in patients with diabetic neuropathy (p = 0.019, p = 0.014). Polypharmacy was also found to be associated with macrovascular complications (p < 0.001, p < 0.001). Macrovascular complications were 2.5 times more common in malnourished patients according to GLIM and 3.2 times more common in patients with decreased gait speed. Conclusion: In this study, we observed that both macrovascular and microvascular complications of diabetes increase susceptibility to geriatric syndromes in elderly individuals. It could be useful to conduct prospective studies in which we can compare the effectiveness of treatment methods on this subject.

Fructose Induces Fluconazole Resistance in Candida albicans through Activation of Mdr1 and Cdr1 Transporters

Candida albicans is a pathogenic fungus that is increasingly developing multidrug resistance (MDR), including resistance to azole drugs such as fluconazole (FLC). This is partially a result of the increased synthesis of membrane efflux transporters Cdr1p, Cdr2p, and Mdr1p. Although all these proteins can export FLC, only Cdr1p is expressed constitutively. In this study, the effect of elevated fructose, as a carbon source, on the MDR was evaluated. It was shown that fructose, elevated in the serum of diabetics, promotes FLC resistance. Using C. albicans strains with green fluorescent protein (GFP) tagged MDR transporters, it was determined that the FLC-resistance phenotype occurs as a result of Mdr1p activation and via the increased induction of higher Cdr1p levels. It was observed that fructose-grown C. albicans cells displayed a high efflux activity of both transporters as opposed to glucose-grown cells, which synthesize Cdr1p but not Mdr1p. Additionally, it was concluded that elevated fructose serum levels induce the de novo production of Mdr1p after 60 min. In combination with glucose, however, fructose induces Mdr1p production as soon as after 30 min. It is proposed that fructose may be one of the biochemical factors responsible for Mdr1p production in C. albicans cells.

Prevalence and antifungal susceptibility of gastrointestinal candidiasis among diabetic patients: A cross-sectional study

Background

Gastrointestinal candidiasis is the most predominant opportunistic human mycosis, especially in diabetic patients. There is a global increase in antifungal resistance coupled with a rarity of information on antifungal susceptibility profiles in Uganda.

Objective

This study aimed to determine the occurrence and antifungal susceptibility of gastrointestinal candidiasis in diabetic patients.

Methods

Stool and fasting blood specimens were obtained from randomly sampled consenting patients with diabetes mellitus at St. Francis Hospital Nsambya in Kampala, Uganda to determine Candida infection, fasting blood glucose and glycated haemoglobin levels. Susceptibility testing was performed on Muller Hilton agar supplemented with 2% glucose and 0.2 µg of methylene blue, using the E-test diffusion method.

Results

Among the 241 patients included in the analyses, the overall prevalence of gastrointestinal candidiasis was 15.4% (n = 37). Candida albicans (62.16%, n = 23) was the predominant species, followed by Candida glabrata (18.92%, n = 7), Candida tropicalis (8.11%, n = 3), Candida krusei (5.41%, n = 2) and Candida dublinensis (5.41%, n = 2). Resistance was observed with miconazole (48.65%), clotrimazole (18.92%) and fluconazole (8.11%). No resistance to itraconazole and nystatin was observed. Gastrointestinal candidiasis was associated with poor glucose control (p ≤ 0.001), prior use of antibiotics (p ≤ 0.001), antifungals (p ≤ 0.001) and corticosteroids (p ≤ 0.001) and was more common among female patients (p = 0.01).

Conclusion

Occurrence of gastrointestinal candidiasis was relatively low among our participants, and infection was associated with poor glucose control, female sex and use of antifungals, antibiotics and corticosteroids.

Biochemical and microbiological analysis of the saliva of institutionalized elderly: With edentulism, use of dentures and presence of biofilm

BACKGROUND

To analyze biochemical and microbiological parameters of the saliva of institutionalized elders and to investigate the relation of these parameters with edentulism, use of dentures and presence of biofilm.

MATERIAL AND METHODS

A cross-sectional study carried was out in seven long-term institutions. Samples (n=161) of unstimulated saliva were collected for analysis of salivary flow, quantification of total proteins and identification of microorganisms. Oral examination was carried out to verify the number of missing teeth, the use of dentures and the presence of visible biofilm on the surface of teeth and dentures. Associations were performed using chi-square or Fisher's exact test (α<0.05). Mann-Whitney Test was used to identify differences in the salivary flow and total proteins (α<0.05).

RESULTS

There was no association between the type of edentulism and use of dentures with biochemical and microbiological parameters of saliva (p>0.05). Associations were observed between the presence of dentures biofilm and the colonization of Streptococcus sp. (p=0.038) and Candida sp. (p=0.03).

CONCLUSIONS

The absence of teeth and use of dentures do not influence the amount of total proteins and the microorganisms count in saliva. Denture biofilms are associated with the presence of Streptococcus sp. and Candida sp. in saliva of institutionalized elders. Key words:Candida, long-stay institutions for elders, saliva, Streptococcus, Staphylococcus.

The Effect of N-Acetylcysteine on Respiratory Enzymes, ADP/ATP Ratio, Glutathione Metabolism, and Nitrosative Stress in the Salivary Gland Mitochondria of Insulin Resistant Rats

This is the first study to assess the effect of N-acetylcysteine (NAC) on the mitochondrial respiratory system, as well as free radical production, glutathione metabolism, nitrosative stress, and apoptosis in the salivary gland mitochondria of rats with high-fat diet (HFD)-induced insulin resistance (IR). The study was conducted on male Wistar rats divided into four groups of 10 animals each: C (control, rats fed a standard diet containing 10.3% fat), C + NAC (rats fed a standard diet, receiving NAC intragastrically), HFD (rats fed a high-fat diet containing 59.8% fat), and HFD + NAC (rats fed HFD diet, receiving NAC intragastrically). We confirmed that 8 weeks of HFD induces systemic IR as well as disturbances in mitochondrial complexes of the parotid and submandibular glands of rats. NAC supplementation leads to a significant increase in the activity of complex I, II + III and cytochrome c oxidase (COX), and also reduces the ADP/ATP ratio compared to HFD rats. Furthermore, NAC reduces the hydrogen peroxide production/activity of pro-oxidant enzymes, increases the pool of mitochondrial glutathione, and prevents cytokine formation, apoptosis, and nitrosative damage to the mitochondria in both aforementioned salivary glands of HFD rats. To sum up, NAC supplementation enhances energy metabolism in the salivary glands of IR rats, and prevents inflammation, apoptosis, and nitrosative stress.

Candida Species Diversity in Oral Cavity of Type 2 Diabetic Patients and their In vitro Antifungal Susceptibility

Objective:

To identify and compare the species variation and Colony Forming Units of the species and antifungal susceptibility from oral rinse samples of individuals in poorly-controlled, moderately-controlled and well controlled diabetes patients with control group.

Subjects and Methods:

Study group comprised of well-controlled, moderately-controlled and poorly controlled Type II diabetic patients grouped according to the level of glycated hemoglobin concentration with 50 patients in each group and 50 healthy individuals. Oral rinse samples were collected in a sterile container with phosphate-buffered saline and then transported immediately for various mycological investigations and antifungal susceptibility tests. Statistical analysis was performed.

Results:

There was a significant difference in frequency of Candida in poorly controlled diabetes when compared to moderately controlled diabetes, well controlled diabetes and normal patients (P = 0.045). A higher number of colony count was seen among poorly controlled diabetes than well controlled, moderately controlled and non diabetic subjects. A comparatively low number of non-albicans were seen in healthy individuals. C. albicans showed an increased resistance to fluconazole in DM patients in comparison to control group (P = 0.001). Other species showed a variable sensitivity pattern.

Conclusion:

The decreased immunity and change in oral habitat in diabetic patients creates a diversification in various species of Candida. These non albicans vary in their susceptibility and pathogenesis. A definite identification of these diverse species in the oral cavity of such patients and their susceptibility mandates proper management to avoid recurrence and drug resistance.

Effect of N-Acetylcysteine on Antioxidant Defense, Oxidative Modification, and Salivary Gland Function in a Rat Model of Insulin Resistance

Oxidative stress plays a crucial role in the salivary gland dysfunction in insulin resistance (IR). It is not surprising that new substances are constantly being sought that will protect against the harmful effects of IR in the oral cavity environment. The purpose of this study was to evaluate the effect of N-acetylcysteine (NAC) on oxidative stress and secretory function of salivary glands in a rat model of insulin resistance. Rats were divided into 4 groups: C-normal diet, C + NAC-normal diet + NAC, HFD-high-fat diet, and HFD + NAC. We have demonstrated that NAC elevated enzymatic (superoxide dismutase, catalase, and peroxidase) and nonenzymatic antioxidants (reduced glutathione (GSH) and total antioxidant capacity (TAS)) in the parotid glands of HFD + NAC rats, while in the submandibular glands increased only GSH and TAS levels. NAC protects against oxidative damage only in the parotid glands and increased stimulated salivary secretion; however, it does not increase the protein secretion in the both salivary glands. Summarizing, NAC supplementation prevents the decrease of stimulated saliva secretion, seen in the HFD rats affected. NAC improves the antioxidative capacity of the both glands and protects against oxidative damage to the parotid glands of IR rats.

The Giant Geriatric Syndromes Are Intensified by Diabetic Complications

By 2015, diabetes has affected more than 415 million people over the world. It is anticipated that 640 million adults will suffer from diabetes in 2040. The elongation of the life expectancy, as the result of better general health care, extends also the time when diabetic complications may develop together with other senility-specific problems. The Giant Geriatric Syndromes (Geriatric Giants) have been qualified by the original Nascher's criteria defined more than 100 years ago, but they are becoming more and more relevant in connection with the aging of societies. The criteria comprise the older age, commonness of the health problem, multifactorial etiology, functional or cognitive impairment, worsened outcome, and increased morbidity and mortality. We described the impact of diabetes on Geriatric Giants including cognitive dysfunction, depression, malnutrition, incontinence, falls and fractures, chronic pain, and the loss of senses. The association of diabetes with Geriatric Giants reveals as a vicious circle with the background of neurovascular complications. However, diabetes influence on the incidence of cancer in elderly was also discussed, since neoplastic diseases associate with Geriatric Giants, for example, chronic pain and depression. The knowledge about these aspects of functional decline in geriatric population is crucial to improve patient care.

Comparison of duplex PCR and phenotypic analysis in differentiating Candida dubliniensis from Candida albicans from oral samples

Candida dubliniensis shares a wide range of phenotypic characteristics with Candida albicans including a common trait called germ tube positivity. Hence, laboratory differentiation of these two species is cumbersome. Duplex PCR analyses for C. albicans and C. dubliniensis was performed directly on DNA extracted from a total of 122 germ tube positive isolates derived from 100 concentrated oral rinse samples from a random cohort of diabetics attending a clinic in Sri Lanka. These results were confirmed by DNA sequencing of internal transcribed spacer (ITS) region of rDNA of the yeasts. Performance efficacy of duplex PCR was then compared with phenotypic identification using a standard battery of phenotypic tests. Of the 122 germ tube positive isolates three were identified by duplex PCR as C. dubliniensis and the remainder as C. albicans. On the contrary, when the standard phenotypic tests, sugar assimilation and chlamydospore formation, were used to differentiate the two species 13 germ tube positive isolates were erroneously identified as C. dubliniensis. Duplex PCR was found to be rapid, sensitive and more specific than phenotypic identification methods in discriminating C. dubliniensis from C. albicans. This is also the first report on the oral carriage of C. dubliniensis in a Sri Lankan population.

A sensitive and a rapid multiplex polymerase chain reaction for the identification of Candida species in concentrated oral rinse specimens in patients with diabetes

OBJECTIVES

Oral candidiasis is being frequently recognized in patients with diabetes, and is associated with multiple pathogens including Candida albicans, Candida parapsilosis, Candida glabrata and Candida tropicalis. The aim of this study was to evaluate a usefulness of a Multiplex Polymerase Chain Reaction as a rapid diagnostic tool for identification of four oral Candida pathogens in patients with diabetes.

MATERIALS AND METHODS

A multiplex PCR was optimized to identify four Candida species in concentrated oral rinse samples. Common reverse primer, ITS4 and four species-specific forward primers targeting ITS1 and ITS2 regions of yeast genome were used. Species-specific single amplicon were detected by agarose gel electrophoresis. Performance efficacy of multiplex PCR was compared with phenotypic identification.

RESULTS

Out of 100 oral rinse samples, 72 were culture positive and of these 43 were at risk of oral Candida infection (>600cfu/ml). Multiple Candida species including C. albicans, C. parapsilosis and C. tropicalis were identified in 22 samples which had risk of oral Candida infection. In total, 85 patients were positive for Candida by multiplex PCR and of them 49 had multiple Candida species. All 43 colonized specimens were also positive by multiplex PCR. C. albicans was the most predominant organism (75/85) followed by C. parapsilosis (47/85), C. tropicalis (17/85) and C. glabrata (6/85). In specimens with multiple species, the two most common organisms were C. albicans and C. parapsilosis. Multiplex PCR yielded a sensitivity of 10 Candida cells/ml of oral rinse sample.

CONCLUSIONS

Multiplex PCR is found to be rapid, sensitive and specific than phenotypic identification methods in discriminating multiple Candida species in oral rinse specimens.

Prevalence of oral Candida colonization in patients with diabetes mellitus

OBJECTIVES OF THE STUDY

We aimed to assess the prevalence of oral Candida colonization in patients with diabetes and its relationship with factors such as Candida species, serum glucose level, and the susceptibility rate of isolated yeasts to antifungals.

PATIENTS

Random samples were obtained from 113 patients with type 2 diabetes, 24 patients with type 1 diabetes, and 105 healthy controls.

MATERIALS AND METHODS

The samples were taken by swabbing the oral mucosa of patients with diabetes mellitus and healthy individuals. Afterwards the samples were inoculated onto CHROMagar-Candida. The growing colonies were counted, and the isolated yeasts were identified by PCR-RFLP and RapID methods. Various isolated species of Candida were also subjected to susceptibility testing of antibiotic drugs. Blood samples were taken to evaluate glycosylated hemoglobin (HbA1c).

RESULTS

Although the Candida carriage rate and density were statistically higher in diabetics than healthy individuals, no direct association was found between having high Candida-burden and glycosylated hemoglobin. The most commonly isolated species in both diabetics and controls was Candida albicans. Of the tested antifungal drugs, the highest rate of resistance was found against itraconazole, followed in frequency by ketoconazole and fluconazole.

CONCLUSIONS

This study identified a significant association between the poor glycemic control and the higher prevalence rates of Candida carriage and density in diabetic patients. In addition, a high prevalence of C. dubliniensis in diabetic patients was found, which might be misdiagnosed with its morphologically related species, C. albicans.

Treatment of oral fungal infections using antimicrobial photodynamic therapy: a systematic review of currently available evidence

The aim was to review the efficacy of antimicrobial photodynamic therapy (PDT) in the treatment of oral fungal infections. To address the focused question "Should PDT be considered a possible treatment regimen for oral fungal infections?" PubMed/Medline and Google-Scholar databases were searched from 1997 up to March 2014 using various combinations of the following key words: "Candida albicans"; "Candidiasis"; "Candidosis"; "denture stomatitis"; "oral" and "photodynamic therapy". Original studies, experimental studies and articles published solely in English language were sought. Letters to the editor, historic reviews and unpublished data were excluded. Pattern of the present literature review was customized to mainly summarize the pertinent information. Fifteen studies (3 clinical and 12 experimental) were included. All studies reported antimicrobial PDT to be an effective antifungal treatment strategy. One study reported PDT and azole therapy to be equally effective in the treatment of oral fungal infections. Methylene blue, toluidine blue and porphyrin derivative were the most commonly used photosensitizers. The laser wavelengths and power output ranged between ∼455 nm-660 nm and 30 mW-400 mW. The energy fluence ranged between 26-245 J cm(-2) and the duration or irradiation ranged between 10 seconds and 26 minutes. Clinical effectiveness of antimicrobial PDT as a potent therapeutic strategy for oral fungal infections requires further investigations.