Speciation Of Candida Research Articles

Species distribution and antifungal susceptibility profile of <i>Candida spp</i> isolated from urine of hospitalized patients in Dschang District Hospital, Cameroon

Candiduria refers to the presence of Candida species in urine, It is a common nosocomial infection afflicting the urinary tract. The aim of our study was to determine the prevalence of candiduria in hospitalized patients in Dschang District Hospital, and to evaluate the susceptibility patterns of Candida spp isolated from some commonly used antifungal drugs. Midstream urine samples were collected from 122 hospitalized patients at the Dschang District Hospital, then speciation of Candida was done based on colony colour on CHROMagar Candida medium. Antifungal susceptibility testing of the isolates was performed by the Broth dilution method. A total of 51 isolates of Candida species were recovered from 122 urine samples. Candida albicans was the most prevalent species 41.2% (21 isolates), followed by C. parapsilosis (27.5%), C. glabrata (17.6%), C. krusei (7.8%) and C. tropicalis (5.9%). Antifungal susceptibility test indicated that 100% and 96.1% of the Candida isolates were resistant to Amphotericin B and Nystatin respectively. Resistance varied depending on the species and the respective antifungal agents. We can conclude that candiduria is relatively common in hospitalized patients. The isolates were very resistant to polyenes (amphotericin B and nystatin) and most isolates were sensitive to azoles. Therefore, the species identification of Candida isolates along with their antifungal susceptibility pattern can help the clinicians in adequate treatment of the patients with candiduria.Keywords: Candiduria, Candida spp, Hospitalized patients, Antifungal susceptibility.

Isolation and Speciation of Candida in Type II Diabetic Patients using CHROM Agar: A Microbial Study.

Newer Candida species are now becoming increasingly predominant commensal in the oral cavity. Aim of the study was to identify and compare different Candida species in the oral cavity of Type II diabetic individuals. The present microbial study was carried out for the duration of three months. Sixty participants were included in the study and divided into two groups of 30 individual each. Group I consisted of patients with Type II diabetes while Group II consisted of healthy individuals without diabetes or any other systemic disease. A total of 3 ml of unstimulated whole saliva was collected from them and centrifuged at 5000 rpm for fives minutes. This pellet was plated onto CHROM agar medium plates and incubated at 37°C for at least 3-4 days. CHROM agar plates were visualized daily at 24 hours, 72 hours and followed up to seven days to check for growth. Candida speciation was done by counting the different coloured creamy colonies. Comparison of Candida spp. between two groups was done by applying the Student's t-test. A p-value<0.05 was considered as statistically significant. All the species of Candida, namely, Candida albicans, Candida glabrata, Candida dubliniensis, Candida krusei, Candida parapsilosis except for Candida tropicalis showed a significantly higher (p<0.001) occurrence in the diabetic group compared to the healthy group. The highest identified species is C. parapsilosis, second being C. albicans in both the groups. C. parapsilosis is now considered as one of the significant causes of Candida infection in the oral cavity. This increased virulence will affect the global burden of Candidiasis as few treatment options are available for this new pathogen.

Speciation of Candida isolates obtained from diarrheal stool

Candida is the most common fungi causing diarrhea. As pathogenesis and susceptibility to antifungals might vary in different species of Candida, their speciation is essential. The aim of this study was to identify different species of Candida and investigate their antifungal susceptibility pattern. Of 2036 diarrheal stool samples, 212 samples were microscopically positive for budding yeast cells. We selected 50 of these samples and cultured on blood agar and MacConkey agar and incubated at 37°C for 18–24 h. Tiny colonies confirmed by means of Gram staining as budding yeast cells were subcultured on Sabouraud’s dextrose agar. Speciation of Candida was carried out using the germ tube test and inoculation into chrome agar and corn meal agar. Antifungal susceptibility testing was carried out as per CLSI guidelines using voriconazole, fluconazole, itraconazole, and amphotericin B. Candida was mostly isolated from children younger than 12 years (50%) and from male patients. A total of 64 isolates were obtained. Candida krusei (52%) was the most common isolate, followed by Candida tropicalis (16%), Candida albicans (0.02%), and Candida parapsilosis (0.01%). The isolates were mostly susceptible to voriconazole (97.4%), itraconazole (79.4%), amphotericin B (66.6%), and fluconazole (18%). Candida diarrhea was mostly seen in individuals younger than 12 years, most commonly caused by C. krusei. Resistance to fluconazole was high. A rising resistance to amphotericin B is alarming. Speciation of Candida is important to see the difference in antifungal susceptibility in different species.

Direct colony polymerase chain reaction for rapid identification of yeasts isolated from blood specimen

Context: Bloodstream infections (BSIs) caused by yeasts have an increasing frequency due to the growing population of immunosuppressed individuals. Among yeasts, Candida remains the most prevalent species with the increase in the incidence of non-albicans Candida species. Apart from Candida, other yeasts are also involved in causing BSI. High mortality associated with Candida and other yeast infection can be reduced by prompt and appropriate antifungal therapy. Hence, rapid identification and speciation of yeasts isolated from blood play a significant role in the management of the patients. Since conventional methods used for speciation of Candida and other yeasts are laborious, time-consuming and often unclear, rapid and accurate molecular techniques are required. Materials and Methods: Instead of using purified genomic DNA as template for polymerase chain reaction (PCR), we used yeast colony and cell suspensions in water and 0.10M potassium hydroxide as template for PCR. Candida albicans, Trichosporon and Cryptococcus neoformans were used as reference strains. Further, a total of 100 yeast isolates were also tested. All reactions were performed using the universal fungal primers ITS1 and ITS4; the PCR products were then digested with restriction enzyme (Msp1). Results: Direct colony PCR (DCPCR) produced sharp and distinct bands compared to the cell suspensions with the reference strains. All the 100 clinical isolates tested also produced distinct bands. Conclusion: DCPCR approach not only reduces the DNA template preparation time but is also easy, rapid and reduces the cost of PCR.

Isolation and identification of Candida and Non albicans Candida species using chromogenic medium

Background: Identification of Candida to species level is required to reduce morbidity & mortality as non albicans candida species are being recovered with greater frequency nowadays.CHROM Agar has the advantage of rapid identification and speciation of Candida by making use of chromogenic substrates. Material & Methods: A prospective study was carried out from February 2014 to May 2014. The material for the study constituted various clinical samples that were sent routinely to the microbiology laboratory for culture and sensitivity testing. CHROM Agar Candida was used to differentiate Candida species along with standard yeast identification methods and antifungal susceptibility testing. Results: A total of 45 Candida species isolates were recovered in which Non albicans candida 35(77.78%) remained higher in comparison to C. albicans 10(22.22%) with C. krusei 15(33.3%), C.glabrata 13(28.9%) and C.tropicalis 7(15.6%).C.albicans was isolated mainly from respiratory medicine ward (5), C. troplicalis from medical intensive care unit (03), C. glabrata and C.krusei with eleven isolates each from neonatal intensive care unit. C.krusei (26.67%) and C.glabrata (26.67%) remained predominant in blood, C.tropicalis (13.33%) in urine and C.albicans (8.89%) in sputum.C.albicans sensitivity to Fluconazole, Voriconazole and Amphotericin B was 70%, 70% and 90% respectively. C.krusei remained resistant to Voriconazole (60%) but susceptible to Amphotericin B (80%) whereas C. tropicalis depicted sensitivity of 71% to both Fluconazole and Amphotericin B. Conclusion: CHROM Agar Candida shows good potential in identification of azole and amphotericin B resistant candida species, which in combination with local antifungal susceptibility pattern shall help to optimize the initiation of antifungal therapy and further avoid treatment failures.

English

Candida is one of the most frequently encountered opportunistic fungi that cause infection in humans. The pathogenesis of Candida is complex and probably varies with each infection. This study was conducted to understand the prevalence of Candida from various clinical specimens of patients and to show the emergence of Non albicans Candida in clinical samples. This study also focused on the antifungal susceptibility which guides the clinicians to treat the infection effectively. METHODS: Clinical samples were collected from outpatients and inpatients of Government General Hospital, Kurnool over a period of one year from March2008 to June2009. Isolation, culture, speciation of Candida was done by using standard methods. Antifungal susceptibility testing was done by disc diffusion technique against amphotericin B, nystatin, fluconazole and clotrimazole. RESULTS: Candida manifests in various sites depending on the predisposing factors and immune status of the person. In this study we found the association of Candida with various predisposing factors (Pregnancy, Oral contraceptive pills's, Immune suppression, Diabetes). This study observed the dominance of non-albicans Candida (51%) in the clinical samples over Candida albicans (49%). The maximum antifungal susceptibility was observed against amphotericin B in both the albicans and non-albicans Candia, but non-albicans Candida showed maximum resistance to azoles. CONCLUSION: Candida albicans was the most predominant species (49%) isolated in various clinical samples. There was an increase in the prevalence of non albicans Candida in this study. Among the nonalbicans Candida (51%) Candid tropicalis was the commonest species isolated. Candida albicans showed maximum susceptibility to amphotericin B and maximum resistance to azoles was seen in nonalbicans Candida.

Changing Trends of Vulvovaginal Candidiasis

Introduction:Vulvovaginal candidiasis is one of the most common infections seen in women.Materials and Methods:A total of 300 symptomatic women were studied. High vaginal swabs collected from each patient were processed by Gram stain, culture on Sabourauds dextrose agar and CHROM agar plates. Isolates were identified and speciated using conventional methods and by the color of the colonies on the CHROM agar. Antifungal susceptibility was performed by disc diffusion method for fluconazole (25 μg) and voriconazole (1 μg) discs as per Clinical and Laboratory Standards Institute (CLSI) guidelines.Results:Vulvovaginal candidiasis was found in 53 (17.7%) of cases. Gram stain was positive in 22 (41.41%) of culture positives. Speciation of isolates by conventional and CHROM agar methods showed similar results. C. albicans 35 (66.0%) was the most common species isolated followed by C. tropicalis 14 (26.4%), C. krusei 2 (3.8%), C. parapsilosis and C. glabrata in 1 (1.9%) case each. Sensitivity to fluconazole was found in 91.4% of C. albicans, 57.1% of C. tropicalis and 50.0% of C. krusei. Sensitivity to voriconazole was seen in 91.4% of C. albicans, 85.7% of C. tropicalis and 50.0% of C. krusei. C. parapsilosis and C. glabrata were found sensitive only to voriconazole.Conclusion:CHROM agar has the advantage of being rapid, simple and cost effective method as compared to conventional methods in speciation of Candida. Routine susceptibility testing of Candida isolates help in selecting the most appropriate antifungal agent for vulvovaginal candidiasis.

Phenotypic Characterization and Antifungal Susceptibility Pattern to Fluconazole in Candida species Isolated from Vulvovaginal Candidiasis in a Tertiary Care Hospital.

Vaginal candidiasis is a common gynecological finding among women worldwide. This study was carried out to determine the prevalence of vulvovaginal candidiasis (VVC) along with speciation of Candida with special reference to its antifungal susceptibility pattern to fluconazole and also to evaluate the risk factors responsible for VVC in patients attending our tertiary care hospital in Puducherry, India. This study was carried out in the tertiary care hospital in Puducherry during the period of August 2010 to September 2012.The study group consisted of 180 women between the age group of 15 to 56 years with the complaints of excessive vaginal discharge, pruritis and pain. Materials used for this study consisted of high vaginal swabs from patients with relevant history, attending Obstetrics & Gynecology department. High vaginal swabs were subjected to direct 10% KOH wet mount microscopy, Gram stain, culture onto Sabouraud's dextrose agar (SDA) & 5% sheep blood agar and susceptibility testing to fluconazole was performed using E-test. Candida was isolated in 40 (22.2 %) women & these consisted of C. albicans 26 (65%), C. glabrata 9 (22.5%), C.tropicalis 3 (7.5%) & C. parapsilosis 2 (5%). Susceptibility test carried out on the 40 isolates revealed that 35 (87.5%) Candida isolates were sensitive to fluconazole, 3 (7.5%) were moderately sensitive and 2 (2.5%) were resistant. Thirty one percent patients had itching as the presenting complaints followed by vaginal discharge (29.4%). The high frequency with which C. albicans was recovered in our study and its susceptibility to fluconazole supports the continued use of azole agents for empirical therapy of uncomplicated candidal vulvovaginitis in the community.

Candidal carriage, isolation and species variation in patients undergoing radiotherapy and chemotherapy for head and neck tumours

Background: Opportunistic fungal infections, mainly candidiasis, is common in immunocompromised patients such as those undergoing chemo or radiatiotherapy and pose a great threat. Hence this study was done, attempting to find out the candidal carrier state and species variation, in such patients. Aims and Objectives: To determine the prevalence and speciation of Candida colonizing in the oral cavity of individuals attending to the cancer clinics in south India. Materials and Methods: Study groups comprised of 50 healthy, asymptomatic individuals as controls (Group I); 50 patients on : chemotherapy (Group - II) and 50 patients undergoing radiotherapy for head and neck cancers (Group - III). Mycological tests for the candidal isolation and speciation were done. Results: A total of 49 cases showed candidal culture positivity (32.67%). Candidal carriage was highest in Group II and Group III (38%). C. albicans was the most prevalent species (30%). The culture positivity and the colony forming unit/ml from the subjects of control group and the study group were highly significant, in pair-wise comparisons. Conclusion: Patients undergoing chemotherapy and radiotherapy for head and neck cancers are at a risk of developing oral candidiasis due to immunosuppression. C. albicans is the predominant isolate, but non-albicans species are also emerging as opportunistic pathogens. All may cause a similar spectrum of disease but differences in disease severity and antifungal susceptibility are noted. Hence, speciation can help to target the treatment of the disease in a much better way.

Species distribution and in vitro antifungal susceptibility patterns of Candida

Introduction: Due to advance in medical and surgical management nosocomial fungal infection rate has been increased. Recently Candididiasis has become one of the major fungal infections among hospitalized patients. Several Candida species can give rise to same clinical presentations but their antifungal susceptibility patterns may be different. The aim of the study is species identified of Candida, isolated from different clinical samples and to carry out their in vitro antifungal susceptibility tests. Methods: From different clinical samples several Candida species were isolated. Speciation of Candida was done by using Corn meal agar, Chrom agar and Hi-Candida identification kit. In vitro antifungal susceptibility to fluconazole, ketoconazole and amphotericin B was performed by disc diffusion method as per CLSI document M44A. Results: From 108 samples, most common species isolated was C. albicans (42.5%), followed by C. tropicalis, C. glabrata, C. parapsilosis and C. krusei. Overall 71.87% of isolates were found to be fluconazole sensitive. Fluconazole resistant rate is seen higher in Candida krusei, Candida glabrata, and Candida tropicalis. Ketoconazole was found to be sensitive against 87% of isolates. Amphotericin B was effective against 100% of isolates, although reduced zone size to Amphotericin B was seen by 10 isolates. Conclusion: Speciation of Candida and antifungal susceptibility testing should be done routinely to prevent therapeutic failures.

Species distribution and antifungal susceptibility profile of Candida isolated from urine samples

Background: Candiduria is a common finding in hospitalized patients. The isolation of Candida from urine is challenging for both clinician and microbiologist as to whether the candiduria represents colonization or, lower or upper urinary tract infection including ascending pyelonephritis and renal candidiasis with sepsis. Although Candida albicans is the major cause of candiduria, non-albicans Candida (NAC) has emerged as an important opportunist pathogen. The NAC spp. are not only well adapted to the urinary tract but also are difficult to eradicate than C. albicans. Aims & Objective: The present study aimed to determine the clinico-mycological profile of candiduria in a tertiary care hospital. Material and Methods: A total of 218 Candida spp. isolated from urine samples were included in the study. Speciation of Candida was done by conventional methods and colony colour on HICHROM Candida agar. Antifungal susceptibility testing of the isolates was performed by disc diffusion method on glucose methylene Mueller- Hinton agar (GM-MH). Results: In both the sexes maximum patients belong to age group >50 years. Urinary catheterization, use of broad spectrum antibiotics and diabetes mellitus were the major risks. Isolation of NAC spp. was more. Maximum resistance was seen to fluconazole. Conclusion: The shift towards the NAC spp. as the causative agent of candiduria has generated the concern. Since several NAC spp. are inherently resistant to common antifungal agents, the rapid identification of Candida isolates upto species level along with its in-vitro antifungal susceptibility pattern is important for treatment and management of candiduria.

Non albicans Candida species: its isolation pattern, species distribution, virulence factors and antifungal susceptibility profile

Background: The change in epidemiology and antifungal susceptibility has generated interest of Clinical Microbiologists in identification of Candida up to species level along with antifungal susceptibility pattern. Non-albicans Candida (NAC) has emerged as an important opportunist pathogen. Extracellular hydrolytic enzymes are one of the important virulence attributes of Candida species. Aims & Objective: The present study aimed to determine the species distribution, virulence factors and antifungal susceptibility profile of NAC spp. isolated from various clinical specimens. Material and Methods: Speciation of Candida was done by assessing the germ tube formation, assimilation and fermentation of sugars and colony color on HICHROM Candida agar. In-vitro extracellular hydrolytic enzymes production in NAC spp. was assessed. Antifungal susceptibility testing of the isolates was performed by Hicomb minimum inhibitory concentration (MIC) test. Results: Majority of the isolates were obtained from urine sample (35.6%). C. tropicalis (29.4%) was the major isolate. Maximum extracellular hydrolytic enzymes activity was seen in C. tropicalis. A total of 79 (27.3%) isolates were resistant to fluconazole. Amphotericin B resistance was noted in 17 (5.8%) isolates. Conclusion: NAC spp. cannot be overlooked as mere containment or non-pathogenic commensals as most of them show reduced susceptibility to commonly used antifungal drugs. Extracellular hydrolytic enzymatic activity of NAC Spp. would be an important tool to prove the relation between the infective species of Candida and infection.

Evaluation of HiCrome differential agar for speciation of candida

Background: In recent years, non-albicans Candida (NAC) are being increasingly reported in many laboratories. There is a need to diagnose them early as some of the species are resistant to antifungals. We evaluated the utility of HiCrome agar for speciation of Candida in comparison to conventional methods. Materials and Methods: Ninety-six isolates of Candida were speciated by morphology on corn meal agar (CMA), sugar assimilation tests (SAT), and HiCrome agar. Sensitivity, specificity, and positive predictive and negative predictive values were obtained. Results: Sensitivity of HiCrome agar in identification of Candida albicans was 97.05%, C. tropicalis was 83.33%, C. glabrata 100%, and C. krusei 87.5%; and specificity was 98.07, 91.93, 92, and 92.30%, respectively. Conclusion: The present Candida differential agar is useful in identifying a few of the species. With further modifications this media may replace the need for conventional methods. The rapid availability of results and identification of species in mixed cultures is significant.

Spectrophotometric analysis of the expression of secreted aspartyl proteinases from Candida in leukoplakia and oral squamous cell carcinoma

Candida species are a normal commensal of the oral cavity in healthy individuals, but can become an opportunistic pathogen when the oral ecosystem is unbalanced. Several virulence attributes have been identified in candidal infection, among which are the hydrolases, including the secreted aspartyl proteinases (Saps). This study evaluated and compared the in vitro level of Saps from Candida albicans in nonsmokers, smokers, and patients with leukoplakia and oral squamous cell carcinoma (OSCC). Candida cell count (CCC) at 48 h was also assessed. The Sap level was measured by spectrophotometry in 38 clinical isolates of C. albicans obtained from the oral cavity of the four different groups. Culturing was done in yeast carbon base-bovine serum albumin. Speciation of Candida was performed by using a Candida identification kit, and CCC was measured by hemocytometer. Sap levels and CCC were higher in individuals with leukoplakia and OSCC than in nonsmokers or smokers (P = 0.001); however, there was no significant difference in Sap levels or CCC between smokers and nonsmokers (P = 0.529). Further, an intragroup correlation between CCC and Sap level was also observed. The higher level of Saps from C. albicans in individuals with leukoplakia and OSCC suggests that this pathogen plays a role in disease development and could aid in identifying the pathogenic commensal.

Standards of care for patients with invasive fungal infections within the United Kingdom: A national audit

The objective of this study was to audit the compliance and implementation of the British Society for Medical Mycology standards of care for patients with invasive infections in UK hospitals. A multidisciplinary audit questionnaire regarding the processing of microbiology and histopathology specimens, radiology imaging and clinical management of patients with invasive fungal infections was distributed to UK hospitals. The study has shown that speciation of Candida and Aspergillus isolates from sterile sites was performed in 42-98% of hospitals. Microscopy of bronchoscopy specimens was not undertaken in 13 of 62 (21%) laboratories. Cryptococcal culture and antigen were undertaken routinely in abnormal CSF in 40-75% and 31-83% of at-risk patients but only in 12% of abnormal CSFs in patients without risk factors. Detailed fungal morphology was provided by <50% of histopathology departments. Most hospitals provided a timely HRCT or MRI on patients suspected to have an invasive fungal infection, but early treatment failed to occur in 15% of hospitals. In patients presenting with candidaemia, central venous catheters (CVC) were not changed routinely within 48h in 15%. Improvement in microbiology and histopathology specimen processing as well as rapid interventions such as initiation of anti-fungal therapy or CVC line removal could improve diagnostic rates and clinical outcomes of invasive fungal infections.

The Effect of Complete Dentures with a Metal Palate on Candida Species Growth in HIV‐Infected Patients

This in vivo investigation compared the oral candidal population between heat-cured acrylic resin and nickel-chromium-beryllium alloy in maxillary complete dentures in HIV-infected patients. Split-palate maxillary complete dentures were fabricated for 19 HIV-infected patients: one-half of the palate was made in acrylic resin and the other half in nickel-chromium-beryllium. Patients were divided into low or high CD4+ lymphocyte count groups. Dentures were worn for 5 months. Palatal mucosa was clinically evaluated at baseline, 1, 3, and 5 months after denture insertion. Specimens were collected at 1, 3, and 5 months using a modified imprint culture method. Speciation of Candida was performed using a chromogenic culture medium. Two-sample t-test was employed to determine effects and significant interactions between the control and test groups and the low and high CD4+ lymphocyte groups. A chi(2) test analyzed and compared the results of the clinical evaluation (p < 0.05). Significant differences were observed in the colony counts between both materials during the third (p= 0.046) and fifth months (p= 0.039). The low CD4+ group demonstrated significant differences during the third (p= 0.03) and fifth months (p= 0.05). There were no significant differences between the species of Candida that colonized either material with the exception of Candida dubliniensis (p < 0.001) and "Others" (p < 0.001) during the first and fifth months. There were no significant differences on the clinical appearance of the palatal mucosa between both materials (p= 1.00). The metal base proved to be effective in decreasing the fungal growth typically present in complete dentures. Although overt clinical manifestations were not present, colony counts of Candida species were high in the acrylic resin denture bases of these patients. This investigation demonstrated that metal base complete dentures provide an important alternative dental service for edentulous HIV-positive and other patients who are particularly prone to higher incidences of fungal infections.