scholarly journals Identification and antifungal susceptibility of Saprochaete clavata from invasive infections in Turkey

Author(s):  
Esra Özkaya ◽  
İlknur Tosun ◽  
Enis Fuat Tüfekçi ◽  
Celal Kurtuluş Buruk ◽  
Neşe Kaklıkkaya ◽  
...  

AbstractSaprochaete clavata is an emerging opportunistic pathogen, that causes life-threatening infections, but there are limited evidence and information about the evaluation of in vitro antifungal susceptibility test results. The aim of this study was to determine S. clavata isolates from clinical specimens and to investigate their in vitro antifungal susceptibility. S. clavata was identified by API ID20C AUX (BioMérieux, Brussels, Belgium), MALDI TOF (Bruker Daltonik, Germany), and ITS gene region sequencing. In vitro susceptibility tests were performed using Sensititre YeastOne (TREK Diagnostic System, East Grinstead, UK). During the study period, 4,736 fungi were isolated from various clinical samples and, S. clavata was identified in eight patients with underlying diseases namely, pancreatic neoplasma, acute myeloid leukaemie, follicular lymphoma, cholelithiasis. Anidulafungin and micafungin minimum inhibitory concentration values were 1–2 and 1–4 mg/L, respectively, while those of the azole group antifungals were much lower. This is the first study in Turkey reporting isolation, identification and antifungal susceptibilities of S. clavata from clinical specimens. Higher MIC values seen in some isolates suggest that continuous monitoring of sensitivity rates and observation of regional differences will thus be useful guides in determining infection control and antifungal use policies.

Author(s):  
Janina Noster ◽  
Martin Köppel ◽  
Marie Desnos-Olivier ◽  
Maria Aigner ◽  
Oliver Bader ◽  
...  

Background: Magnusiomyces clavatus and Magnusiomyces capitatus are emerging yeasts with intrinsic resistance to many commonly used antifungal agents. Identification is difficult, and determination of susceptibility patterns with commercial and reference methods is equally challenging. For this reason, few data on invasive infections by Magnusiomyces spp. are available. Objectives: To determine the epidemiology and susceptibility of Magnusiomyces isolates from bloodstream infections (BSI) isolated in Germany and Austria from 2001-2020. Methods: In seven institutions a total of 34 Magnusiomyces BSI were identified. Identification was done by ITS sequencing and MALDI-TOF MS. Antifungal susceptibility was determined by EUCAST broth microdilution and gradient tests. Results: Of the 34 isolates, M. clavatus was more common (N=24) compared to M. capitatus (N=10). BSI by Magnusiomyces spp. were more common in men (62%) and mostly occurred in patients with haemato-oncological malignancies (79%). The highest in vitro antifungal activity against M. clavatus / M. capitatus was observed for voriconazole (MIC 50 0.03/0.125 mg/L), followed by posaconazole (MIC 50 0.125/0.25 mg/L). M. clavatus isolates showed overall lower MICs compared to M. capitatus . With the exception of amphotericin B, low essential agreement between gradient test and microdilution was recorded for all antifungals (0-70%). Both species showed distinct morphologic traits on ChromAgar Orientation and Columbia blood agar, which can be used for differentiation if no MALDI-TOF or molecular identification is available. Conclusion: Most BSI were caused by M. clavatus. The lowest MICs were recorded for voriconazole. Gradient tests demonstrated unacceptably low agreement and should preferably not be used for susceptibility testing of Magnusiomyces spp.


2021 ◽  
Vol 17 ◽  
Author(s):  
Zarifeh Adampour ◽  
Malihe Hasanzadeh ◽  
Hossein Zarrinfar ◽  
Maryam Nakhaei ◽  
Monika Novak Babič

Introduction: Endometrial cancer is one of the most common malignancies of the female genital tract, which can be serious or life-threatening. Microbial infections can be one of the underlying causes of this type of cancer. Case Presentation: The present study describes the isolation of Pichia fermentans (Candida firmentaria var. firmentaria) from the vaginal secretions of a 61-year-old woman affected by endometrial cancer. She reported abdominal pain and vaginal discharge for 3 months, and had a history of diabetes, hypertension, Deep Vein Thrombosis (DVT), and Acute Myeloid Leukemia (AML). The isolated yeast was identified based on nuclear ribosomal internal transcribed spacer (ITS1-ITS2 rDNA) sequence analysis. The in vitro antifungal susceptibility testing showed a higher effect for ketoconazole against P. fermentans than fluconazole, itraconazole and voriconazole. Conclusion: Correct differentiation between P. fermentans and other yeast should be considered. The in vitro antifungal susceptibility testing is recommended for rare yeast, and will help the physicians in providing the best treatment.


2008 ◽  
Vol 7 (4) ◽  
pp. 630-638 ◽  
Author(s):  
János Varga ◽  
Jos Houbraken ◽  
Henrich A. L. Van Der Lee ◽  
Paul E. Verweij ◽  
Robert A. Samson

ABSTRACT Aspergillus ustus is a relatively rare human pathogen causing invasive infections in immunocompromised hosts. In this study isolates originating from clinical and other sources have been examined using molecular, morphological, and physiological approaches to clarify their species assignment. Phylogenetic analysis of partial β-tubulin, calmodulin, actin, and intergenic transcribed spacer sequences indicated that none of the clinical isolates recognized previously as A. ustus belongs to this species. All but two of these isolates formed a well-defined clade related to A. pseudodeflectus based on sequence analysis of protein-coding regions. Morphological and physiological examination of these isolates indicated that they are able to grow above 37°C, in contrast with A. ustus isolates, and give a positive Ehrlich reaction, in contrast with related species including A. granulosus, A. ustus, and A. pseudodeflectus. These isolates are proposed as a new species, A. calidoustus. Antifungal susceptibility testing showed that this species has decreased susceptibilities to several antifungal drugs. The triazoles are inactive in vitro, including the new azole posaconazole.


2016 ◽  
Vol 55 (2) ◽  
pp. 552-567 ◽  
Author(s):  
Nicomedes Valenzuela-Lopez ◽  
Deanna A. Sutton ◽  
José F. Cano-Lira ◽  
Katihuska Paredes ◽  
Nathan Wiederhold ◽  
...  

ABSTRACTHuman infections by coelomycetous fungi are becoming more frequent and range from superficial to systemic dissemination. Traumatic implantation of contaminated plant material is the most common cause. The typical morphological feature of these fungi is the production of asexual spores (conidia) within fruiting bodies called conidiomata. This study aimed to determine the distribution of the coelomycetes in clinical samples by a phenotypic and molecular study of a large set of isolates received from a U.S. reference mycological institution and by obtaining thein vitroantifungal susceptibility pattern of nine antifungals against a selected group of isolates. A total of 230 isolates were identified by sequencing the D1 and D2 domains of the large subunit (LSU) nuclear ribosomal RNA (nrRNA) gene and by morphological characterization. Eleven orders of the phylumAscomycotawere identified:Pleosporales(the largest group; 66.1%),Botryosphaeriales(19.57%),Glomerellales(4.35%),Diaporthales(3.48%),Xylariales(2.17%),HysterialesandValsariales(0.87%), andCapnodiales,Helotiales,HypocrealesandMagnaporthales(0.43% each). The most prevalent species wereNeoscytalidium dimidiatum,Paraconiothyriumspp.,Phoma herbarum,Didymella heteroderae, andEpicoccum sorghinum. The most common anatomical site of isolation was superficial tissue (66.5%), followed by the respiratory tract (17.4%). Most of the isolates tested were susceptible to the majority of antifungals, and only flucytosine showed poor antifungal activity.


2019 ◽  
Vol 216 (7) ◽  
pp. 1615-1629 ◽  
Author(s):  
Andreas Naegeli ◽  
Eleni Bratanis ◽  
Christofer Karlsson ◽  
Oonagh Shannon ◽  
Raja Kalluru ◽  
...  

Streptococcus pyogenes (Group A streptococcus; GAS) is a human pathogen causing diseases from uncomplicated tonsillitis to life-threatening invasive infections. GAS secretes EndoS, an endoglycosidase that specifically cleaves the conserved N-glycan on IgG antibodies. In vitro, removal of this glycan impairs IgG effector functions, but its relevance to GAS infection in vivo is unclear. Using targeted mass spectrometry, we characterized the effects of EndoS on host IgG glycosylation during the course of infections in humans. Substantial IgG glycan hydrolysis occurred at the site of infection and systemically in the severe cases. We demonstrated decreased resistance to phagocytic killing of GAS lacking EndoS in vitro and decreased virulence in a mouse model of invasive infection. This is the first described example of specific bacterial IgG glycan hydrolysis during infection and thereby verifies the hypothesis that EndoS modifies antibodies in vivo. This mechanisms of immune evasion could have implications for treatment of severe GAS infections and for future efforts at vaccine development.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Maxime Moniot ◽  
Rose-Anne Lavergne ◽  
Thomas Morel ◽  
Romain Guieze ◽  
Florent Morio ◽  
...  

Abstract Background Filamentous basidiomycetes are mainly considered to be respiratory tract colonizers but the clinical significance of their isolation in a specimen is debatable. Hormographiella aspergillata was first reported as a human pathogen in 1971. We discuss the role of this mold as a pathogen or colonizer and give an update on diagnostic tools and in vitro antifungal susceptibility. Case presentation We identified three cases of H. aspergillata with respiratory symptoms in a short period of time. One invasive infection and two colonizations were diagnosed. Culture supernatants showed that H. aspergillata can produce galactomannan and β-D-glucan but not glucuronoxylomannan. For the first time, isavuconazole susceptibility was determined and high minimum inhibitory concentrations (MICs) were found. Liposomal amphotericin B and voriconazole have the lowest MICs. Conclusion To date, 22 invasive infections involving H. aspergillata have been reported. On isolation of H. aspergillata, its pathogenic potential in clinical settings can be tricky. Molecular identification and antifungal susceptibility testing are essential considering high resistance against several antifungal therapies.


2006 ◽  
Vol 19 (2) ◽  
pp. 435-447 ◽  
Author(s):  
M. A. Pfaller ◽  
D. J. Diekema ◽  
D. J. Sheehan

SUMMARY Developing interpretive breakpoints for any given organism-drug combination requires integration of the MIC distribution, pharmacokinetic and pharmacodynamic parameters, and the relationship between in vitro activity and outcome from both in vivo and clinical studies. Previously, the Subcommittee for Antifungal Testing of the Clinical and Laboratory Standards Institute (CLSI [formerly National Committee for Clinical Laboratory Standards]) proposed MIC interpretive breakpoints for fluconazole and Candida spp. These breakpoints were considered to be somewhat weak, because the clinical data supporting them came largely from mucosal infections and there were very few infections involving strains with elevated fluconazole MICs. We readdress the issue of fluconazole breakpoints for Candida by using published clinical and microbiologic data to provide further validation of the breakpoints proposed by the CLSI in 1997. We also address interpretive breakpoints for agar disk diffusion testing of fluconazole. The MIC distribution for fluconazole was determined with a collection of 13,338 clinical isolates. The overall MIC at which 90% of the isolates were inhibited was 8 μg/ml: 91% were susceptible (S) at a MIC of ≤8 μg/ml and 3% were resistant (R) (MIC ≥ 64 μg/ml). Similar results were obtained for 2,190 isolates from randomized clinical trials. Analysis of available data for 1,295 patient-episode-isolate events (692 represented mucosal infections and 603 represented invasive infections) from 12 published clinical studies demonstrated an overall success rate of 77%, including 85% for those episodes in which the fluconazole MIC was ≤8 μg/ml, 67% for those episodes in which the MIC was 16 to 32 μg/ml, and 42% for those episodes with resistant (MIC ≥ 64 μg/ml) isolates. Pharmacodynamic analysis demonstrated a strong relationship between MIC, fluconazole dose, and outcome. A dose/MIC ratio of ∼25 was supportive of the following susceptibility breakpoints for fluconazole and Candida spp.: S, MIC ≤ 8 μg/ml; susceptible-dose dependent (SDD), MIC = 16 to 32 μg/ml; R, MIC ≥ 64 μg/ml. The corresponding disk test breakpoints are as follows: S, ≥19 mm; SDD, 15 to 18 mm; R, ≤14 mm.


2021 ◽  
Vol 14 (7) ◽  
Author(s):  
Shaghayegh Rostami Yasuj ◽  
Maral Gharaghani ◽  
Seyed Sajjad Khoramrooz ◽  
Marjan Salahi ◽  
Ali Keshtkari ◽  
...  

Background: Candidemia is the most common systemic infection in hospitalized patients causing high mortality. Hence, the diagnosis of this infection in the early stage with appropriate antifungal therapy is paramount. Objectives: The study aimed at molecular identification of Candida species isolated from candidemia patients and evaluation of the in vitro antifungal susceptibility patterns of these strains to fluconazole, amphotericin B, and caspofungin. Methods: In the present study, 800 hospitalized patients who were suspected to have candidemia were sampled. Candida species were isolated and identified based on morphological characteristics and PCR-sequencing of the ITS1-5.8S-ITS2 region. Antifungal susceptibility tests for fluconazole, amphotericin B, and caspofungin were performed according to the Clinical and Laboratory Standards Institute protocol M27-A3. Also, clinical data were recorded from the patients' records. Results: Twenty-seven patients among the sample of hospitalized patients were found to have candidemia. A total of 33.3% of candidemia patients were treated with amphotericin B, in which case the mortality rate was 14.8%. The majority of patients (59%) were from the neonatal intensive care unit, and premature birth was the most common underlying condition. Candida albicans (n = 18; 66.6%) was the most common species isolated from blood cultures, followed by C. parapsilosis (n = 7; 25.9%), C. pelliculosa (n = 1; 3.7%), and C. tropicalis (n = 1; 3.7%). Only one C. albicans isolate resistant to fluconazole (minimum inhibitory concentration = 32 µg/mL). Conclusions: Generally, C. albicans has been the most frequent causative agent of candidemia. Resistance to antifungal drugs among candidemia agents was rare. Also, the identification of Candida isolates at the species level with in vitro antifungal susceptibility tests helps manage candidemia patients better and decrease the mortality rate among them.


2021 ◽  
Vol 7 (5) ◽  
pp. 351
Author(s):  
Mohammed A. El-Kholy ◽  
Ghada F. Helaly ◽  
Ebtisam F. El Ghazzawi ◽  
Gamal El-Sawaf ◽  
Sherine M. Shawky

Background: The incidence of candidiasis caused by non-albicans Candida (NAC) species is increasing. Candida tropicalis has emerged as one of the most important NAC species. This study aims to examine the antifungal susceptibility profile and some virulence factors of C. tropicalis isolated from various clinical specimens. Methods: A total of 71 C. tropicalis isolates from various clinical specimens (69.01%, 18.31%, 9.86%, and 2.82% of isolates were collected from urine, respiratory samples, blood, and skin and soft tissue infections, respectively) from ICU patients in Alexandria, Egypt. The isolates were identified at species level by CHROMagar Candida and VITEK 2 compact system. Furthermore, the antifungal susceptibility was determined using the VITEK 2 system AST-YS07 card containing different antifungals. Hemolysin, phospholipase, and proteinase activity and biofilm formation were also tested as virulence factors. Results: Only 30 isolates (42.25%) were non-susceptible (MIC ≥ 4 µg/mL) to fluconazole, of which 28 isolates showed non-susceptibility (MIC ≥ 0.25 µg/mL) to voriconazole. All isolates showed both hemolysin and proteinase activities, while only 9 isolates (12.68%) showed phospholipase production and 70 isolates (98.59%) demonstrated biofilm formation. Strong biofilm production was observed among the blood culture isolates (85.71%), followed by the respiratory and urinary isolates (61.54% and 46.94%, respectively). Conclusions: This study sought to provide useful data on the antifungal susceptibility of C. tropicalis isolates from ICU patients suffering from invasive infections with an increased trend towards elevated MICs levels of both fluconazole and voriconazole. Due to the high incidence of systemic candidiasis and antifungal resistance, C. tropicalis is emerging as a serious root of infections. Therefore, early and accurate identification of Candida species along with susceptibility testing is of utmost importance.


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