Non-albicans Candida Isolates Research Articles

SPECIES DISTRIBUTION AND ANTIFUNGAL SUSCEPTIBILITY OF VAGINAL <i>CANDIDA</i> ISOLATES

Introduction: Vulvovaginal candidiasis (VVC) is the most common Candida infection in females of reproductive age. Data concerning the species identification and antifungal susceptibility of vaginal Candida isolates are of great importance for the infection management. Aim: The aim of the present study was to determine the species distribution and antifungal susceptibility of Candida isolates obtained from vaginal samples of women with VVC. Material and methods: A total of 125 vaginal Candida isolates were collected and tested. The definitive species identification was performed by VITEC2 Compact (Bio Merieux, France) using YST ID cards. The minimum inhibitory concentrations (MICs) of nine antifungal agents were determined by the commercial system Micronaut-AM (Merlin Diagnostika GmbH, Germany). Results: Overall, 8 Candida species were established among the vaginal yeast isolates. The most common was C. albicans (77.6%), followed by C. glabrata (12%), C. krusei (4%), C. kefyr (2.4%), C. spherica (1.6%), C. lusitaniae, C. utilis, and C. sake (each one 0.8%). All C. albicans and 20 non-albicans Candida (NAC) were susceptible to nine antifungal agents. In the group of NAC, 8 isolates were resistant to fluconazole – 5 C. krusei with intrinsic resistance, 2 C. spherica, and 1 C. sake. The fluconazole MICs of C. spherica and C. sake were 32 - 128 μg/mL, and 16 μg/mL, respectively. Conclusions: C. albicans was the main causative agent of VVC. Among NAC, C. glabrata was the predominant species. In general, vaginal C. albicans and non-albicans Candida were susceptible to azoles as well as echinocandins, amphotericin B and 5-fluorocytosine. Of particular interest was the detection of rare non-albicans Candida isolates with acquired resistance to azoles.

Comparison of Candida colonization in intensive care unit patients with and without COVID-19: First prospective cohort study from Turkey.

Candida species are the primary cause of fungal infections in intensive care units (ICUs). Despite the increasing prevalence of Candida-related infections, monitoring the progression of these infections from colonization in COVID-19 ICU patients lacks sufficient information. This study aims prospectively to compare 62 COVID-19 and 60 non-COVID-19 ICU patients from admission to discharge in terms of colonization development, rates, isolated Candida species, risk factors, and Candida infections during hospitalization. A total of 1464 samples were collected at specific time intervals from various body sites [mouth, skin (axilla), rectal, and urine]. All samples were inoculated onto CHROMagar Candida and CHROMagar Candida Plus media, and isolates identified using MALDI-TOF MS. COVID-19 patients exhibited significantly higher colonization rates in oral, rectal, and urine samples compared to non-COVID-19 patients, (p<0.05). Among the Candida species, non-albicans Candida was more frequently detected in COVID-19 patients, particularly in oral (75.8%-25%; p<0.001) and rectal regions (74.19% - 46.66%; p<0.05). Colonization with mixed Candida species was also more prevalent in the oropharyngeal region (p<0.05). Mechanical ventilation and corticosteroid use emerged as elevated risk factors among COVID-19 patients (p<0.05). Despite the colonization prevalence, both COVID-19-positive and negative patients exhibited low incidences of Candida infections, with rates of 9.67% (n=6/62) and 6.67% (n=3/60), respectively. Consequently, although Candida colonization rates were higher in COVID-19 ICU patients, there was no significant difference in Candida infection development compared to the non-COVID-19 group. However, the elevated rate of non-albicans Candida isolates highlights potential future infections, particularly given their intrinsic resistance in prophylactic or empirical treatments if needed. Additionally, the high rate of mixed colonization emphasizes the importance of using chromogenic media for routine evaluation.

Assessment of Proteinase and Phospholipases Enzymes Isolated from Pathogenic Candida species from Women Attending Antenatal Clinic at Mbeya Zonal Referral Hospital, Southern Highland Regions of Tanzania

Fungi are a global cause of vaginal infections, with vaginal candidiasis largely afflicting tropical regions including most parts of sub-Saharan Africa. In Tanzania, baseline studies have established the prevalence of Candida species among symptomatic and asymptomatic pregnant women in Dar es Salaam (Namkinga et al., 2005; Namkinga 2012) and in Mwanza (Mushi et al., 2019). However, no study that has been done to determine the above-mentioned enzymes form Candida species in Southern Highland Regions of Tanzania. Several factors have been reported to contribute to the virulence and pathogenicity of Candida, among others the production of extracellular hydrolytic enzymes, particularly phospholipase and proteinase. Therefore, this study was designed to investigate the in vitro production of phospholipases and proteinases enzymes from isolated pathogenic Candida spp from pregnant women.Of the 280 samples collected from symptomatic and asymptomatic pregnant women attending antenatal clinics at Mbeya Zonal Referral Hospital were tested for several microbiological methods such as the wet mount microscopic preparations (hanging drop) and the Gram stained smears for microscopy, cultures on Sabouraud’s dextrose agar and on Conidia enhancing medium (Corn meal agar), germ tube test, biochemical tests, sugar fermentation-assimilation tests and molecular test to characterize Candida species.Phospholipase production was performed in egg yolk medium while the production of proteinase was done in a medium containing bovine serum albumin. All analyses were performed in triplicates. The results showed that; out of the 280 tested, 155 (74.3%) isolates were phospholipase positive while 201 (96.6%) were positive for proteinase activity. C. albicans was the species with the highest number of positive isolates for proteinase and phospholipase 110 (95.6%), and most strains of C. albicans produce both enzymes (phospholipases and proteinases). The non-albicans Candida isolates were also producers of hydrolytic enzymes that, consequently, might be able to cause infections as favorable conditions arises.

Epidemiology of Candida Species Colonizing Mucosae of HIV-Infected Patients in Two Healthcare Centers of Cameroon During 2018-2020

Aims: This study aimed to investigate Candida species colonizing HIV-infected patients in Bafoussam and Yaounde in Cameroon.&#x0D; Study Design: Cross-sectional study.&#x0D; Place and Duration of Study: Yaoundé Central Hospital (YCH) and Bafoussam Regional Hospital (BRH) between October 2018 and December 2020.&#x0D; Methodology: We included 804 HIV-infected (681 women; 123 men; age range 21-81 years). Vaginal discharge, oral swab, stools, and urine were collected, and mycological diagnosis including direct macroscopic and microscopic analyses, culture on Sabouraud chloramphenicol medium, culture on chromogenic medium, germ tube test, evidence of chlamydospores production, biochemical analysis was performed. Yeast isolates were identified using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS).&#x0D; Results: Eight hundred and four patients were recruited, and 2754 samples were collected. The colonization frequency was 17.35%, and 513 yeasts were isolated. Overall, Candida albicans 251 (48.92%) was the most frequently isolated. Non-albicans Candida (NAC) isolates have been classified into 16 species, including Candida krusei (14.23%), Candida glabrata (9.94%), Candida parapsilosis (8.18%), and Candida tropicalis (7.99%) as the major ones. There was a relationship (P-value= 0.00) between antiretroviral therapy and Candida species colonization.&#x0D; Conclusion: The results provide information on the epidemiology of Candida species in HIV-infected patients in Cameroon.

PROFILING AND SPECIATION OF CANDIDA SPECIES BY USING HICHROME AGAR FROM VARIOUS CLINICAL AND POSTMORTEM SAMPLES IN LIVESTOCK AND POULTRY

Animal Candidiasis is associated with oral and upper respiratory disease, pyothorax, ocular lesions, intestinal disease and urocystitis in dog and cats and causes arthritis in horses and mastitis and abortion in cattle. The present study was undertaken to determine the prevalence of Candida species among various clinical and post mortem samples of livestock and poultry. All samples were collected using aseptic precautions. After receiving in the Central University laboratory, the samples were inoculated onto both Blood agar and MacConkey agar, XLD agar and SDA agar and plates were incubated at 37 oC for 24 hours aerobically. The colonies appeared as smooth, pasty, opaque, white or beige were suspected as Candida colonies and Gram stain was done for confirmation. The speciation of the Candida isolates was performed by inoculating it on Hicrome Candida differential agar. The Hicrome agar was prepared as per the manufacturer’s instructions and incubated at 37 o C for 24 hours aerobically. The antibiotic sensitivity test was performed with Highrome agar plate. The pure culture of Candida albicans were streaked in hichrome agar plate and antibiotic disc were placed in appropriate distance and incubated at 37 oC for 24 hours aerobically. Biofilm study of yeast was performed with Sterile 96-well polystyrene plates which were inoculated with 200 µl bacterial suspension (105 CFU/ml) in BHI medium and incubated at 37 o C for 24 hrs without shaking. Species identification of Candida was done by the morphology and color of the colonies. The Candida albicans produce light green colonies, C. tropicalis metallic blue colonies, C.krusei produces purple fuzzy colonies, and C. glabrata white to cream-colored colonies. Out of 298 Candida isolates, C. Albicans was the most common species in 210 (70.46%) strains. The remaining 88 (29.5%) strains showed Non-albicans Candida. Out of 88 Non-albicans Candida isolates, Candida isolates, 20 were C. tropicalis (23%), 28 were C. glabrata (32%), 18 were Candida parapsilosis (20%) and 22 were C. krusei (25%) respectively (Table 1). Out of 298 isolates from oronasal swab (HVS), the most common species was C. Albicans followed by C. tropicalis, C. glabrata, Candida parapsilosis and C. krusei. Among the 16 urine samples, the most common species was C. Albicans followed by C. tropicalis, C. glabrata, and C. krusei were isolated.

Species distribution and susceptibility profiles of oral candidiasis in hematological malignancy and solid tumor patients.

Oral colonization and infection by Candida species are common in cancer patients receiving chemoradiotherapy, which has significantly increased in recent years. This study aimed to evaluate the frequency, distribution, and antifungal susceptibility profiles of Candida species isolates in patients with hematological malignancy and solid tumors. This study was conducted on a total of 45 cancer patients undergoing treatment with concurrent chemoradiotherapy within 2019-2020. The identification of Candida species was accomplished based on conventional examination and molecular assays. The minimum inhibitory concentrations were determined based on the guidelines of Clinical and Laboratory Standards Institute. The highest prevalence rates of oral candidiasis were observed in patients with chronic lymphoid leukemia (24.4%) and lymphoma (20%). The majority of the patients had oral candidiasis caused by non-albicans Candida species (64.4%). The results of the multiplex PCR for the identification of Candida glabrata, Candida nivariensis, Candida bracarensis, and species-specific Candida parapsilosis complex showed that all isolate amplification products at 397 bp and 171 bp were related to C. glabrata and C. parapsilosis, respectively. There was a significant difference in the Candida species distribution between the hematological malignancies and solid tumors patients. The results of MIC showed that clotrimazole, voriconazole, and caspofungin were the most effective antifungal drugs against oral non-Candida albicans isolates. An understanding of the epidemiology of oral candidiasis among hematological malignancies and solid tumors patients is currently imperative to guide optimal empirical treatment strategies for affected patients.

P367 Candida sepsis in neonates a neglected pathogen: study from neonatal intensive care unit tertiary care hospital

Poster session 3, September 23, 2022, 12:30 PM - 1:30 PM IntroductionSignificance of Candida species in neonatal intensive care units (NICU) is increasingly being recognized. It is the third most common cause of late-onset sepsis in NICU patients and accounts for 9 to 13% of bloodstream infections (BSI) in neonates. Although Candida albicans has historically been the most frequently isolated species, recently non-albicans Candida (NAC) have emerged as an important opportunistic pathogen, notably Candida tropicalis, C. parapsilosis, C. krusei, C. glabrata, and C auris. This changing trend and the increasing use of azoles agents is now a matter of concern due to the emerging resistance of the non-albicans species to azoles.AimTo evaluate the Candida sepsis in neonates from neonatal intensive care units from a tertiary care hospital.Material and MethodsA cross-sectional study was conducted in the Department of Microbiology, University College of Medical Sciences and Guru Teg Bahadur Hospital, East Delhi, India, during the period of July 2021 to December 2021. Overall, 30 suspected Candida sepsis patients from neonatal intensive care units were enrolled in the present study. The Candida spp. Isolated was identified as per standard mycological techniques. Preliminary identification was done by colony morphology on SDA, chromogenic media (Hichrome, Himedia Pvt. Ltd.), grown at 45°C, germ tube test, chlamydospore formation, and was confirmed by carbohydrate fermentation and assimilation tests. Antifungal susceptibility testing (AFST) was performed for Fluconazole (25 μg), and amphotericin B (AMB, 100 units) using the disc diffusion method on Muller-Hinton agar supplemented with 2% glucose and methylene blue (5 mg/ml). Zone diameters were interpreted as per the approved Clinical Laboratory Standards (CLSI-M44-A) guidelines. Quality control for AFST was performed using C. albicans-ATCC 90028 and C. parapsilosis-ATCC 22019.Statistical analysisThe statistical analysis was done using Statistical Package for Social Sciences (SPSS) version. The P-value ˂0.05 were considered as statistically significant.ResultOut of 30 Candida species from suspected septicemia neonates, non-albicans Candida (NAC) species accounted for (87%) compared to C. albicans (13.4%). Candida tropicalis was predominant at 9 (30%) followed by C. glabrata 8 (27%), C.parapsilosis 4 (13.3%), and C. krusei 3(10%), Pichia species (4.2%), and C.auris (3.4%). Antifungal sensitivity of the NAC isolates demonstrated >85% resistance to fluconazole amongst C. glabrata, C. parapsilosis, though amphotericin B had 100% sensitivity in all Candida species. The risk factor for candidemia as observed in our study were low birth weight 26(87%), use of broad-spectrum antibiotics 25 (83.4%), presence of an orogastric tube 18 (60%), and total parental nutrition 9 (30%) were significantly associated statistically (P <.05, paired t-test). The overall mortality amongst these neonates was 16.6%.ConclusionFungal BSI has emerged as an important cause of morbidity and mortality in neonates. Reporting of fungal bloodstream infections and the spectrum of species involved are essential measures in neonatal intensive care units in order to implement appropriate preventive and therapeutic strategies.

Prevalence and Antifungal Susceptibility of Clinically Relevant Candida Species, Identification of Candida auris and Kodamaea ohmeri in Bangladesh

Candida species are major fungal pathogens in humans. The aim of this study was to determine the prevalence of individual Candida species and their susceptibility to antifungal drugs among clinical isolates in a tertiary care hospital in Bangladesh. During a 10-month period in 2021, high vaginal swabs (HVSs), blood, and aural swabs were collected from 360 patients. From these specimens, Candida spp. was isolated from cultures on Sabouraud dextrose agar media, and phenotypic and genetic analyses were performed. A total of 109 isolates were recovered, and C. albicans accounted for 37%, being derived mostly from HVSs. Among non-albicans Candida (NAC), C. parapsilosis was the most frequent, followed by C. ciferrii, C. tropicalis, and C. glabrata. Three isolates from blood and two isolates from aural discharge were genetically identified as C. auris and Kodamaea ohmeri, respectively. NAC isolates were more resistant to fluconazole (overall rate, 29%) than C. albicans (10%). Candida isolates from blood showed 95% susceptibility to voriconazole and less susceptibility to fluconazole (67%). Two or three amino acid substitutions were detected in the ERG11 of two fluconazole-resistant C. albicans isolates. The present study is the first to reveal the prevalence of Candida species and their antifungal susceptibility in Bangladesh.

Comparison of antifungal activity of fluconazole and clove leaf essential oil on Candida species isolate in HIV/AIDS patients with oral candidiasis

Current treatment guidelines include fluconazole as the main therapeutic option for treating oral candidiasis infection in HIV/AIDS patients, but resistance increases. Several in vitro studies have shown that clove leaf essential oil with the main content of eugenol can be an alternative therapy for oral candidiasis that is resistant to fluconazole. This study was conducted to determine the zone of inhibition of clove leaf essential oil and fluconazole against Candida isolates species that cause oral candidiasis in HIV/AIDS patients. This study showed that the average fluconazole disk 25 μg/mL inhibition zone in 20 isolates of Candida albicans species was larger than non-albicans Candida species. The zone of inhibition of clove leaf essential oil was significantly lower than that of fluconazole (p &lt; 0.05), except at a concentration of 15% against non-albicans Candida isolates. Clove leaf essential oil has an antifungal effect that can inhibit the growth of Candida species, so it can be considered an alternative antifungal therapy. Clove leaf essential oil concentration of 15% showed no significant difference in antifungal activity with the standard drug fluconazole in isolates of non-albicans Candida species.

Increased diversity, fungal burden, and virulence of oral Candida spp. in patients undergoing anti-tuberculosis treatment

Some studies have demonstrated a high prevalence of Candida species in patients with tuberculosis (TB). This is most likely due to long-term antimicrobial therapy. To date, no longitudinal studies addressed the effects of anti-TB treatment on the fungal burden and virulence of Candida spp. This study investigated the prevalence and virulence of Candida spp. in the oral cavity of 30 TB patients at different stages of treatment through a cohort study. These results were compared with those of 60 systemically healthy individuals in a cross-sectional study.Oral rinse samples from TB patients were collected before 45 and after 120 days of treatment. In the control group, the biological samples were collected only once. Candida spp. were identified by restriction fragment length polymorphism (RFLP) assays, and the following virulence factors were studied: phospholipase C and proteinase production, as well as Candida spp. biofilm and hyphae formation.The clinical diagnosis of TB and its treatment time were associated with the greater fungal burden (p < 0.0001), presence of non-albicans Candida (NAC) species (p = 0.0003), and increased virulence factors when compared with the Candida spp. isolated from systemically healthy individuals. The results showed that anti-TB treatment time was responsible for the increased fungal burden and isolation of NAC in TB patients (p = 0.0233).The increased prevalence, quantification, and virulence of Candida spp. isolated from the oral cavity of TB patients highlight the greater risk of oral lesions and cases of systemic dissemination in these patients.

Prevalence of Candida infection in Covid-19 pandemic: A study from a tertiary care center in Central India

Background: Corona virus disease 2019 (COVID-19) infections may be associated with a wide range of bacterial and fungal co-infections. Candida and mucor are the common fungus encountered during this pandemic. Candida is one of the commonly encountered opportunistic fungi that cause superficial mucosal infections usually, but can invade tissue and produce life threatening infections. Candida species recognized as one of the major agent of hospital Acquired (nosocomial) fungal infections. Keeping this in background the current study was conducted. Aims and Objective: To estimate the prevalence of candida infection in tertiary care hospital of Indore. Materials and Methods: The present study was done in the period of one and half year. During this period all received clinical specimens like urine, sputum; high vaginal swab and pus suspected for fungal infection from Covid as well as non-Covid patients were processed according to standard protocol. The specimen was subjected to preliminary tests like wet mount, Gram’s stain, culture on sabourads dextrose agar (SDA) and Hichrome agar, germ tube test, sugar assimilation test and culture on Cornmeal agar (dalmau technique) for candida species were done. For statistical analysis Chi-square test was performed and p ≤ 0.05 was considered statistically significant. Results: The prevalence of Candidiasis was 0.86%. Non-albicans candida (65.9%) isolates was more than Candida albicans (34.07%). Among non-albicans species, C. tropicalis was 27.4% followed by C. glabrata 16.29%, C. krusei 15.55%,C. parapsilosis 5.92% and C. lusitenia 0.74% were the major isolates. Males were affected more than the females. In both the genders maximum patients were from the age group of &gt;60 years. Maximum number of Candida isolates was from blood followed by urine, pus, sputum, vaginal swab and aural swab. Most common risk factors for candidiasis noted in this study was diabetes mellitus in both Covid as well as non-Covid patients. Conclusion: Non albicans candida are gradually increasing in India. Speciation of candida play an important role in preliminary treatment because different species is intrinsically resistant to different antifungal drugs and have different antifungal susceptibility pattern.

The Inhibition of Non-albicans Candida Species and Uncommon Yeast Pathogens by Selected Essential Oils and Their Major Compounds.

The epidemiology of yeast infections and resistance to available antifungal drugs are rapidly increasing, and non-albicans Candida species and rare yeast species are increasingly emerging as major opportunistic pathogens. In order to identify new strategies to counter the threat of antimicrobial resistant microorganisms, essential oils (EOs) have become an important potential in the treatment of fungal infections. EOs and their bioactive pure compounds have been found to exhibit a wide range of remarkable biological activities. We investigated the in vitro antifungal activity of nine commercial EOs such as Thymus vulgaris (thyme red), Origanum vulgare (oregano), Lavandula vera (lavender), Pinus sylvestris (pine), Foeniculum vulgare (fennel), Melissa officinalis (lemon balm), Salvia officinalis (sage), Eugenia caryophyllata (clove) and Pelargonium asperum (geranium), and some of their main components (α-pinene, carvacrol, citronellal, eugenol, γ-terpinene, linalool, linalylacetate, terpinen-4-ol, thymol) against non-albicans Candida strains and uncommon yeasts. The EOs were analyzed by GC-MS, and their antifungal properties were evaluated by minimum inhibitory concentration and minimum fungicidal concentration parameters, in accordance with CLSI guidelines, with some modifications for EOs. Pine exhibited strong antifungal activity against the selected non-albicans Candida isolates and uncommon yeasts. In addition, lemon balm EOs and α-pinene exhibited strong antifungal activity against the selected non-albicans Candida yeasts. Thymol inhibited the growth of all uncommon yeasts. These data showed a promising potential application of EOs as natural adjuvant for management of infections by emerging non-albicans Candida species and uncommon pathogenic yeasts.

Candiduria—Study of Virulence Factors and Its Antifungal Susceptibility Pattern in Tertiary Care Hospital

Background The increased incidence of candiduria in hospitalized patients is due to the use of indwelling devices, long-term antibiotics, parenteral nutrition, and immunocompromised status of the patient. In this study, an attempt was made to speciate, characterize, and determine the antifungal susceptibility pattern of Candida isolated from urinary tract infections (UTIs). Materials and Methods A total of 70 Candida isolates were obtained from urine samples. The isolated Candida species were studied for the production of virulence factors like phospholipase, protease activities, hemolysin, and biofilm production. Antifungal susceptibility testing of the isolated yeasts was done using Mueller-Hinton agar supplemented with 0.5 mg/mL methylene blue by E-test method for amphotericin B, fluconazole, caspofungin, and voriconazole. Results Out of 70 isolates, Candida tropicalis was the most frequently isolated species (65.7%), followed by Candida albicans (14.3%), Candida glabrata (7.1%), Candida krusei (5.7%), Candida parapsilosis (4.3%), and Candida dubliniensis (2.9%). A total of 37.1% were biofilm producers, 62.9% showed proteinase activity, 38.6% were phospholipase positive, and 58.6% isolates showed hemolytic activity. Antifungal susceptibility profile of Candida species showed 38.6, 25.7, 15.7, and 12.9% resistance to amphotericin B, fluconazole, caspofungin, and voriconazole, respectively. Conclusion A rising trend in isolation of non-albicans Candida from urinary isolates was noticed, which was statistically significant when comparing catheterized and noncatheterized urinary isolates from our study. However, there was no statistically significant difference when different virulence factor expressions were compared among Candida spp. isolated from catheterized and noncatheterized urinary samples. Due to this rise in non-albicans Candida species causing UTI that are intrinsically resistant to certain antifungal agents like azoles and increasing incidence of antifungal resistance, it is essential to monitor the antifungal susceptibility profile of Candida species causing candiduria.

Comparative evaluation of the Bruker Biotyper and Vitek MS matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) systems for non-albicans Candida and uncommon yeast isolates

IntroductionRapid and accurate diagnosis is critically important in invasive and disseminated fungal infections for appropriate antifungal treatment. HypothesisMALDI-TOF MS systems are effective for fast and accurate identification of Candida species. AimWe aimed to compare two MALDI-TOF MS systems for the rapid identification of non-albicans Candida and rare clinical yeast species. MethodologyThis study included 157 isolates representing 23 yeast species. All isolates were identified using Bruker MALDI Biotyper and VITEK MS systems. If both MALDI-TOF MS systems yielded the same results for a certain isolate, the identification is regarded as correct. We performed internal transcribed spacer (ITS) DNA sequencing on five fungal isolates with discordant species names or that were unidentified by the two MALDI-TOF MS systems. ResultsThe yeast identification sensitivity of MALDI Biotyper was 98.7%, whereas that of VITEK MS was 96.8%. Both MALDI-TOF MS systems correctly identified all strains belonging to four prevalent species, namely, Candida parapsilosis, Candida tropicalis, Candida glabrata, and Candida krusei. For the 19 rare clinical yeast species, identification rates were 96.7% for MALDI Biotyper and 91.7% for VITEK MS. The ITS sequence analysis of five isolates yielded two Meyerozyma caribbica, two Cyberlindnera fabianii, and one Candida dubliniensis. ConclusionsThis study showed the high performance of both MALDI-TOF MS systems, identifying over 90% of yeast isolates in a short time. The disadvantages of these systems are that some species are not present in the databases and it cannot distinguish closely related species. The sensitivity of MALDI-TOF MS systems constantly improves with the expansion of databases in parallel with taxonomic developments for the identification of rare clinical yeast species.

Bacteriocin-Like Inhibitory Substances from Probiotics as Therapeutic Agents for Candida Vulvovaginitis.

Probiotics can potentially prevent and treat diseases. We examined the inhibitory activity of bacteriocin-like inhibitory substances (BLISs) from potentially probiotic lactobacilli and streptococci on Candida albicans and non-Candida albicans clinical isolates from women with vulvovaginitis. Using agar well diffusion assays, BLISs inhibited both Candida albicans and non-Candida albicans isolates. The BLIS from L. pentosus isolates had the highest anti-Candida activity (33/45; 73.3%), followed by BLISs from isolates of L. paracasei subsp. paracasei (31/45; 68.9%), L. rhamnosus I (30/45; 66.7%), L. delbrueckii subsp. lactis I (30/45; 66.7%), and S. uberis II (30/45; 66.7%). Upon characterization according to the retained activity under variable physical and chemical conditions, the BLISs showed stability against heat, pH, and surfactants, but were protease-sensitive, which suggests a proteinaceous nature of the active substances. Using crystal violet assays, the BLISs reduced the Candida biofilm biomass significantly as compared to a control group that lacked BLISs. In vivo testing of the antagonistic activity was performed using the Galleria mellonella (G. mellonella) larvae model. BLISs significantly improved survival in G. mellonella larvae treated with Candida isolates on the first, second, and seventh days, as compared to larvae inoculated with Candida only (p < 0.01). The results show that BLISs can be used as biotherapeutic agents in vulvovaginal candidiasis.

Antifungal Susceptibility of Non-albicans Candida Species in A Tertiary Care Hospital, Bulgaria

Background: Emerging non-albicans Candida (NAC) species are a major threat because of their intrinsic or acquired resistance to routinely applied antifungal agents. Objectives: The purpose of our study was to reveal in vitro activity of nine antifungal agents against NAC isolates. Methods: A total of 67 NAC (27 Candida glabrata, 10 C. tropicalis, 6 C. krusei, 6 C. parapsilosis, 4 C. lusitaniae, 4 C. lipolytica, etc.) were identified and tested. The antifungal susceptibility was estimated on the basis of minimum inhibitory concentrations (MIC). Results: Overall, 13 species were determined, of which C. glabrata was the most common (40.3%), followed by C. tropicalis (14.9%), C. krusei, and C. parapsilosis (8.9 % each). Forty-nine NAC isolates (73.13%) demonstrated decreased susceptibility to one or more antifungals, and 18 of them were resistant to all azoles. Out of 27 C. glabrata, 12 (44.4%) were resistant to fluconazole with MICs: 32 - &gt;128 µg/mL and 15 (55.6%) were intermediate with MICs: 8 - 16 µg/mL Non-albicans Candida revealed a good susceptibility to echinocandins. Amphotericin B resistance was found in 5.97% of the isolates. Of particular interest was the detection of 6 (8.95%) multidrug-resistant NAC, which expressed resistance to azoles and echinocandins and/or amphotericin B. Conclusions: About one-fourth of the studied NAC were resistant to all azoles. These findings as well as the detection of several multidrug-resistant isolates determine the necessity of susceptibility testing of clinically important yeast isolates and control of the antifungal drugs in our hospital.

Speciation of Candida using CHROMagar from various clinical specimens and their antifungal susceptibility pattern at a tertiary care hospital.

Background: Candida albicans remains the most common and are responsible for various clinical infections ranging from mucocutaneous infection to life threatening invasive diseases. But recent epidemiological data shift from C.albicans to non albicans Candida species and also increased resistance to antifungal drugs made the scenario a serious concern.&#x0D; Methods: A total of 156 Candida isolates from various clinical specimens received in the department of Microbiology were taken up for the study over a period of one year i.e. from March 2019 to February 2020. The Candida were grown on Sabouraud dextrose agar to be evaluated for colony appearance, macroscopic examination, Gram staining, germ tube, urea hydrolysis etc. The Candida isolates were speciated by using CHROMagar medium. Antifungal susceptibility testing was performed as recommended by Clinical and Laboratory Standards Institute (CLSI) M44-A document.&#x0D; Results: The isolation of non albicans Candida (54.5%) predominated over Candida albicans (45.5%). Non albicans Candida isolated were Candida tropcalis 40(25.6%), Candida krusei 21(13.4%), Candida glabrata 17(10.8%) and Candida dublinensis 07(4.4%) each. Candida species were all susceptible to Amphotericin B, followed by fluconazole (67.4%), miconazole (51.9%) and ketoconazole (22.5%).&#x0D; Conclusions: The accurate species identification of Candida is important for the treatment because not all species respond to the same treatment and also because of the increasing antifungal resistance. CHROMagar is a convenient and rapid method of identification of Candida species specially in resource limited poor settings. &#x0D; Keywords: antifungal susceptibility testing; Candida albicans; CHROMagar; non albicans Candida

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

OBJECTIVESOropharyngeal 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.METHODSOral 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.RESULTSIt 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).CONCLUSIONSThe 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.

&lt;p&gt;Distribution of Pathogenic Yeasts in Different Clinical Samples: Their Identification, Antifungal Susceptibility Pattern, and Cell Invasion Assays&lt;/p&gt;

IntroductionSpecies of genus Candida are part of the common microbiota of humans; however, some of the Candida species are known opportunistic pathogens. Formation of biofilms, resistance to antifungal drugs, and increase in asymptomatic infections demands more studies on isolation, identification and characterization of Candida from clinical samples.MethodsThe present manuscript deals with assessment of authentic yeast identification by three methods viz., DNA sequencing of 28S rRNA gene, protein profiles using MALDI-TOF MS, and colony coloration on chromogenic media. Antifungal susceptibility and in vitro cell invasion assays were performed to further characterize these isolates.ResultsComparison of three methods showed that DNA sequence analysis correctly identified more than 99.4% of the isolates up to species level as compared to 89% by MALDI-TOF MS. In this study, we isolated a total of 176 yeasts from clinical samples and preliminary morphological characters indicated that these yeast isolates belong to the genus Candida. The species distribution of isolates was as follows: 75 isolates of Candida albicans (42.61%), 50 of C. tropicalis (28.40%), 22 of C. glabrata (12.5%), 14 of C. parapsilosis (7.95%) and 4 of Clavispora lusitaniae (2.27%). Other species like Cyberlindnera fabianii, Issatchenkia orientalis, Kluyveromyces marxianus, Kodamaea ohmeri, Lodderomyces sp., and Trichosporon asahii were less than 2%. Antifungal susceptibility assay performed with 157 isolates showed that most of the isolates were resistant to the four azoles viz., clotrimazole, fluconazole, itraconazole, and ketoconazole, and the frequency of resistance was more in non-albicans Candida isolates. The susceptibility to azole drugs ranged from 7% to 48%, while 75% of the tested yeasts were susceptible to nystatin. Moreover, 88 isolates were also tested for their capacity to invade human cells using HeLa cells. In vitro invasion assay showed that most of the C. albicans isolates showed epithelial cell invasion as compared to isolates belonging to C. glabrata, C. parapsilosis and C. tropicalis.DiscussionThe identification of yeasts of clinical origin by sequencing of 28S rRNA gene performed better than MALDI-TOF MS. The present study reiterates the world scenario wherein there is a shift from Candida strains to emerging opportunistic pathogens which were earlier regarded as environmental strains. The present study enlightens the current understanding of identification methods for clinical yeast isolates, increased antifungal drug resistance, epithelial cell invasion as a virulence factor, and diversity of yeasts in Indian clinical samples.

A Case–Control Study of Candidaemia in Very Low Birthweight Infants in a Tertiary Hospital in Johannesburg

Abstract Background: Candidaemia is a significant cause of morbidity and mortality in infants. The mortality rate ranges between 21% and 76%. Non-albicans Candida (NAC) species are increasing in incidence as well as resistance to azoles. Very low birthweight (VLBW) infants have numerous risk factors which predispose them as a group to invasive candidaemia. Methods: A retrospective case–control study of candidaemia in VLBW infants admitted to the neonatal unit at Charlotte Maxeke Johannesburg Hospital between 1 January 2015 and 31 December 2017 was undertaken. Clinical and demographic characteristics of VLBW infants who developed candidaemia, commonest Candida species, antifungal susceptibility profiles and outcomes (death) were identified. A total of 71 infants with confirmed positive blood cultures for candidaemia from the National Health Laboratory Services database were selected, and each case was allocated 3 controls; the final sample comprised 284 infants. Results: Bacterial sepsis, chronic lung disease, necrotising enterocolitis (NEC) and NEC surgery, other surgery, anaemia and ventilation, all showed a strong association with development of candidaemia in the infants. The most common isolate was Candida parapsilosis (59.1%), followed by Candida albicans (30.9%). The cases of candidaemia overall and NAC isolates increased over the study years. Resistance to azoles by NAC was demonstrated. Mortality was 31.2% and 28.2% in controls and cases, respectively. The difference in death between the two groups was not statistically significant. Conclusions: The study demonstrated an increasing rate of candidaemia, predominance of NAC isolates and increased resistance to azoles. Stricter infection control measures and medical intervention strategies should be implemented.