Molecular epidemiology of Candida tropicalis isolated from urogenital tract infections.

Candida tropicalis is a common human pathogenic yeast, and its molecular typing is important for studying the population structure and epidemiology of this opportunistic yeast, such as epidemic genotype, population dynamics, nosocomial infection, and drug resistance surveillance. In this study, the antifungal susceptibility test and multilocus sequence typing (MLST) analysis were carried out on C. tropicalis from central China. Among 64 urogenital isolates, 45 diploid sequence types (DST) were found, of which 20 DSTs (44.4%) were new to the central database. The goeBURST analysis showed that CC1 (clonal complex) was the only azole-resistant (100%, 10/10) cluster in Wuhan, which was composed of DST546, DST225, DST376, and DST506, and most of the strains (90%, 9/10) were isolated from the urinary tract. Potential nosocomial infections were mainly caused by CC1 strains. The azole resistance rate of urinary isolates (50.0%, 21/42) was higher than that of vaginal isolates (27.3%, 6/22). The genotype diversity and novelty of vaginal isolates were higher than those of urinary isolates. C. tropicalis population in Wuhan was genetically diverse and divergent from that seen in other countries. In this study, there were significant differences in genotype and azole susceptibility between urine and vaginal strains. The azole-resistant cluster (CC1) found in urine is of great significance for the clinical treatment and prevention of nosocomial infection. The newly discovered DSTs will contribute to further study the similarity, genetic relationship, and molecular epidemiology of C. tropicalis worldwide.

Clonality of Fluconazole-Nonsusceptible Candida tropicalis in Bloodstream Infections, Taiwan, 2011-2017.

Candida tropicalis is the leading cause of non-C. albicans candidemia in tropical Asia and Latin America. We evaluated isolates from 344 patients with an initial episode of C. tropicalis candidemia. We found that 58 (16.9%) patients were infected by fluconazole-nonsusceptible (FNS) C. tropicalis with cross resistance to itraconazole, voriconazole, and posaconazole; 55.2% (32/58) of patients were azole-naive. Multilocus sequence typing analysis revealed FNS isolates were genetically closely related, but we did not see time- or place-clustering. Among the diploid sequence types (DSTs), we noted DST225, which has been reported from fruit in Taiwan and hospitals in Beijing, China, as well as DST376 and DST505-7, which also were reported from hospitals in Shanghai, China. Our findings suggest cross-boundary expansion of FNS C. tropicalis and highlight the importance of active surveillance of clinical isolates to detect dissemination of this pathogen and explore potential sources in the community.

Risk factors and outcomes of candidemia caused by Candida parapsilosis complex in a medical center in northern Taiwan.

To investigate the risk factors and outcomes associated with Candida parapsilosis candidemia, a retrospective study was conducted at a tertiary medical center in northern Taiwan. Patients with C. parapsilosis candidemia and corresponding controls with C. albicans candidemia were chosen and their demographics, comorbidities, risk factors, and clinical outcomes were reviewed. Antifungal susceptibility tests were performed using the Sensititre YeastOne colorimetric system. Matrix-assisted laser desorption ionization-time of flight mass spectrometry was used to classify the genomic species. Of the 270 candidemias found in 253 patients, C. albicans was the most common Candida species isolated (43.0%), followed by C. parapsilosis (22.6%), C. tropicalis (17.4%), and C. glabrata (10.0%). The 30-day mortality of C. parapsilosis candidemia was significantly lower than that of C. albicans candidemia (21.7% vs. 53.9%, P<0.001). C. parapsilosis was positively associated with antifungal agent exposure [OR 7.261 (95% CI, 1.603-32.879), P=0.010], but negatively associated with Candida colonization [OR 0.303 (95% CI, 0.123-0.745), P=0.009], and immunosuppressant use [OR 0.264 (95% CI, 0.099-0.705), P=0.008]. In-hospital mortality was associated with the Sequential Organ Failure Assessment Score [OR 1.255 (95% CI, 1.002-1.573), P=0.048]. The clinical outcomes did not differ across genomic species and in the minimum inhibitory concentrations of fluconazole.

The essential oil of Allium sativum as an alternative agent against Candida isolated from dental prostheses / Aceite esencial de Allium sativum como tratamiento alternativo contra aislamientos de Candida procedentes de prótesis dentales

Background. The colonization of the surfaces of dental prostheses by Candida albicans is associated with the development of denture stomatitis. In this context, the use of fluconazole has been proposed, but its disadvantage is microbial resistance. Meanwhile, the oil of Allium sativum has shown an effect in controlling biofilm formation by C. albicans. Aims. The objective of this study was to determine the antifungal activities of the essential oil of A. sativum and fluconazole against clinical isolates of Candida species obtained from rigid, acrylic-based partial or total dentures and to compare these agents’ effects on both biofilm and planktonic cells. Methods. A total of 48 clinical isolates obtained from the acrylic surface of partial or complete dentures were examined, and the following species were identified: C. albicans, Candida glabrata, Candida tropicalis, and Candida krusei. For each isolate, the antifungal activities of the essential oil of A. sativum and fluconazole against both biofilm and planktonic cells were evaluated using the Clinical & Laboratory Standards Institute (CLSI) M27-A3 method. The isolates were also evaluated by semiquantitative XTT reduction. Results. All planktonic Candida isolates were susceptible to the essential oil of A. sativum, whereas 4.2% were resistant to fluconazole. Regarding susceptibilities in biofilms, 43.8% of biofilms were resistant to A. sativum oil, and 91.7% were resistant to fluconazole. Conclusions. All planktonic cells of the different Candida species tested are susceptible to <1mg/ml A. sativum oil, and the majority are susceptible to fluconazole. Susceptibility decreases in biofilm cells, with increased resistance to fluconazole compared with A. sativum oil. The essential oil of A. sativum is thus active against clinical isolates of Candida species obtained from dentures, with effects on both biofilm and planktonic cells in vitro (AU)

Antecedentes. La colonización por parte de Candida albicans de las superficies de las prótesis dentales se asocia con el desarrollo de estomatitis. Se ha propuesto el uso de fluconazol, pero su desventaja es la resistencia microbiana. El aceite de Allium sativum ha mostrado su efectividad al controlar la formación de biopelícula de objetivos. Objetivos. Determinar la sensibilidad de cepas clínicas de especies de Candida, obtenidas de prótesis dentales parciales o totales rígidas de base acrílica, al aceite esencial de A. sativum y comparar su efecto en células planctónicas y en biopelícula. Métodos. Se incluyeron 48 cepas clínicas de la superficie acrílica de prótesis dentales totales o parciales, identificadas entre las siguientes especies: C. albicans, Candida glabrata, Candida tropicalis y Candida krusei. Se evaluó la sensibilidad de cada una al aceite esencial de A. sativum y al fluconazol mediante la metodología M27-A3 del CLSI, tanto sobre células planctónicas como en biopelícula, y mediante el método semicuantitativo de la reducción de XTT en el último caso. Resultados. Todas las cepas planctónicas de Candida fueron sensibles al aceite esencial de A.sativum, mientras que el 4,2% fue resistente al fluconazol. En cuanto a su sensibilidad en biopelícula, el 43,8% fue resistente a A. sativum y el 91,7% lo fue al fluconazol. Conclusiones. Todas las cepas en forma planctónica de las diferentes especies de Candida fueron sensibles a concentraciones inferiores a 1mg/ml del aceite esencial de A. sativum y en menor proporción a fluconazol. La sensibilidad disminuyó en las células en biopelícula, con mayor resistencia al fluconazol en comparación con el aceite esencial de A. sativum. Por tanto, el aceite esencial de A. sativum es activo frente a cepas clínicas de diferentes especies de Candida, obtenidas de dentaduras, con efectos en biopelícula y células planctónicas in vitro (AU)

Biofilms Formed by Isolates from Recurrent Vulvovaginal Candidiasis Patients Are Heterogeneous and Insensitive to Fluconazole.

Vulvovaginal candidiasis (VVC) is a global health problem affecting ∼75% of women at least once in their lifetime. Here we examined the epidemiology of VVC in a patient cohort to identify the causative organisms associated with VVC. Biofilm-forming capacity and antifungal sensitivity profiles were also assessed. We report a shifting prevalence of Candida species with heterogeneous biofilm-forming capacity, which is associated with altered antifungal drug sensitivity.

Epidemiology of candidemia and antifungal susceptibility in invasive Candida species in the Asia-Pacific region.

In the Asia-Pacific region, Candida albicans is the predominant Candida species causing invasive candidiasis/candidemia in Australia, Japan, Korea, Hong Kong, Malaysia, Singapore and Thailand whereas C. tropicalis is the most frequently encountered Candida species in Pakistan and India. Invasive isolates of C. albicans, C. parapsilosis complex and C. tropicalis remain highly susceptible to fluconazole (>90% susceptible). Fluconazole resistance (6.8-15%), isolates with the non-wild-type phenotype for itraconazole susceptibility (3.9-10%) and voriconazole (5-17.8%), and echinocandin resistance (2.1-2.2% in anidulafungin and 2.2% in micafungin) among invasive C. glabrata complex isolates are increasing in prevalence. Moreover, not all isolates of C. tropicalis have been shown to be susceptible to fluconazole (nonsusceptible rate, 5.7-11.6% in China) or voriconazole (nonsusceptible rate, 5.7-9.6% in China).

Candidaemia in a paediatric centre and importance of central venous catheter removal.

The aim of this study is to identify differences in distribution of Candida species, resistance to antifungals and clinical outcome, as well as the identification of potential risk factors associated with candidaemia in children. We conducted a retrospective analysis in children ≤18 years with blood culture proven candidaemia identified between 2004 and 2012. Patients were divided into two groups (Group 1, <3 months, n = 51; Group 2, ≥3 months, n = 197) to identify any potential difference between the neonatal and early infantile periods in terms of risk factors and distribution of Candida species. A total of 248 distinct episodes of candidaemia were identified over the study period. The most frequently isolated Candida species were C. albicans (53.2%), followed by C. parapsilosis (26.2%), C. tropicalis (8.1%). Of the 248 episodes, 71 episodes (28.6%) resulted in death within 30 days from the onset of candidaemia. In Group 1, failure of central venous catheter (CVC) removal was found to be associated with a 20.5-fold increase in mortality [95% CI (3.9, 106.5); P < 0.001], compared to a 5.9-fold increased risk with hypoalbuminaemia [95% CI (1.03, 34.1); P = 0.046]. For Group 2, the increased risk was 23-fold for failure of CVC removal [95% CI (7.48, 70.77); P < 0.001], 7.4-fold for mechanical ventilation [95% CI (2.64, 21.08); P < 0.001], 4.4-fold for hypoalbuminaemia [95% CI (1.56, 12.56); P = 0.005], 3.1-fold for neutropaenia [95% CI (1.31, 7.69); P = 0.010] and 2.2-fold for male gender [95% CI (1.02, 4.71); P = 0.043]. Therapeutic choices should be guided by sound knowledge of local epidemiological trends in candidaemia. Removal of CVC significantly reduces mortality and is an essential step in the management of candidaemia.

[Yeast species in vulvovaginitis candidosa]. / Vulvovaginitis candidosában eloforduló sarjadzógomba-speciesek.

INTRODUCTION: Vulvovaginal candidiasis is the most common mycosis, however, the available information about antifungal susceptibilities of these yeasts is limited. AIM: To compare the gold standard fungal culture with a new molecular identification method and report the incidence of yeast species in vulvovaginitis candidosa. METHOD: The authors studied 370 yeasts isolated from vulvovaginal candidiasis and identified them by phenotypic and molecular methods. RESULTS: The most common species was Candida albicans (85%), followed by Candida glabrata, and other Candida species. CONCLUSION: At present there are no recommendations for the evaluation of antifungal susceptibility of pathogenic fungal species occurring in vulvovaginal candidiasis and the natural antifungal resistance of the different species is known only. Matrix Assisted Laser Desorption Ionization Time of Flight identification can be used to differentiate the fluconazole resistant Candida dubliniensis and the sensitive Candida albicans strains.

Effective photodynamic therapy against microbial populations in human deep tissue abscess aspirates.

BACKGROUND AND OBJECTIVE: The primary therapy for deep tissue abscesses is drainage accompanied by systemic antimicrobial treatment. However, the long antibiotic course required increases the probability of acquired resistance, and the high incidence of polymicrobial infections in abscesses complicates treatment choices. Photodynamic therapy (PDT) is effective against multiple classes of organisms, including those displaying drug resistance, and may serve as a useful adjunct to the standard of care by reduction of abscess microbial burden following drainage. STUDY DESIGN/MATERIALS AND METHODS: Aspirates were obtained from 32 patients who underwent image-guided percutaneous drainage of the abscess cavity. The majority of the specimens (24/32) were abdominal, with the remainder from liver and lung. Conventional microbiological techniques and nucleotide sequence analysis of rRNA gene fragments were used to characterize microbial populations from abscess aspirates. We evaluated the sensitivity of microorganisms to methylene blue-sensitized PDT in vitro both within the context of an abscess aspirate and as individual isolates. RESULTS: Most isolates were bacterial, with the fungus Candida tropicalis also isolated from two specimens. We examined the sensitivity of these microorganisms to methylene blue-PDT. Complete elimination of culturable microorganisms was achieved in three different aspirates, and significant killing (P < 0.0001) was observed in all individual microbial isolates tested compared to controls. CONCLUSIONS: These results and the technical feasibility of advancing optical fibers through catheters at the time of drainage motivate further work on including PDT as a therapeutic option during abscess treatment.

Hydroxyurea therapy in sickle cell anemia patients aids to maintain oral fungal colonization balance.

BACKGROUND: The aim of this study was to evaluate the frequency of Candida species and presence of lesions in the oral cavity of patients with sickle cell anemia (SS). METHODS: The study included 30 patients diagnosed with sickle cell anemia and taking hydroxyurea for at least 90 days (SS/HU+); and 39 patients with sickle cell anemia and without hydroxyurea therapy (SS/HU-). Two control groups were constituted by healthy individuals matched to the test groups in age, gender, and oral conditions (C/HU+ for SS/HU+ and C/HU- for SS/HU-). Oral clinical examination and anamnesis were performed. Yeasts were collected by oral rinses and identified by API system. Antifungal susceptibility evaluation was performed according to the CLSI methodology. Data obtained for microorganisms counts were compared by Student's t test (SS/HU+ vs. C/HU+ and SS/HU- vs. C/HU-) using MINITAB for Windows 1.4. Significance level was set at 5%. RESULTS: No oral candidosis lesions were detected. Significant differences in yeasts counts were observed between SS/HU- group and the respective control, but there were no differences between SS/HU+ and C/HU+. Candida albicans was the most prevalent species in all groups. Candida famata was observed both in SS and control groups. Candida dubliniensis, Candida glabrata, Candida krusei, Candida tropicalis, Candida pelliculosa, and Candida parapsilosis were observed only in SS groups. Most strains were susceptible to all antifungal agents. CONCLUSION: Hydroxyurea therapy seems to decrease candidal counts and resistance rate in sickle cell anemia patients. However, further studies should be conducted in the future to confirm this finding. Hydroxyurea therapy in sickle cell anemia patients maintains fungal species balance in oral cavity.

Invasive infection in an acute myeloblastic leukemia patient due to triazole-resistant Candida tropicalis.

Non-albicans Candida species are being increasingly reported as causes of nosocomial fungal infections. For example, invasive candidiasis caused by C. tropicalis has been associated with hematologic malignancies. In this study, we report a fatal case of fungemia and a possible urinary and pulmonary infection in a leukemia patient that was due to a strain of C. tropicalis resistant to 2 triazole antifungals.