scholarly journals Aspergillus calidoustus sp. nov., Causative Agent of Human Infections Previously Assigned to Aspergillus ustus

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
Keyword(s):  
Antifungal Susceptibility ◽  
Antifungal Drugs ◽  
Protein Coding ◽  
Coding Regions ◽  
Aspergillus Ustus ◽  
Invasive Infections ◽  
Human Infections ◽  
Immunocompromised Hosts ◽  
A New Species

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.

scholarly journals In vitro antifungal susceptibilities of six antifungal drugs against clinical Candida glabrata isolates according to EUCAST

2020 ◽  
Author(s):  
Mahnaz Fatahinia ◽  
Ali Zarei Mahmoudabadi ◽  
Marzieh Halvaeizadeh ◽  
Elham AboualiGalehdari ◽  
Neda Kiasat
Keyword(s):  
Candida Glabrata ◽  
Antifungal Susceptibility ◽  
Antifungal Drugs ◽  
Health Centers ◽  
Regional Patterns ◽  
Alternative Drug ◽  
Life Threatening ◽  
Immunocompromised Hosts ◽  
Dose Dependent

Background and Purpose: Candida glabrata is the second cause of candidiasis. The mortality rate of C. glabrata infections is about 40%; accordingly, it may be life threatening, especially in immunocompromised hosts. Regarding this, the current study was conducted to evaluate the regional patterns of the antifungal susceptibility of clinical C. glabrata isolated from the patients referring to the health centers located in Ahvaz, Iran. Materials and Methods: In this study, a total of 30 clinical strains of C. glabrata isolates were recovered from different body sites (i.e., vagina, mouth, and urine). Phenotypic characteristics and molecular methods were used to identify the isolates. The minimum inhibitory concentration (MIC) was determined according to the European Committee on Antimicrobial Susceptibility Testing. Results: Our findings demonstrated that 20%, 80%, and 6.7% of the isolates were resistant to amphotericin B, terbinafine, and posaconazole, respectively, while all the isolates were found to be fluconazole susceptible dose dependent and susceptible to voriconazole and caspofungin. Conclusion: Our study suggested that voriconazole had high potency against C. glabrata isolates. Consequently, this antifungal agent can be an alternative drug in the treatment of resistant patients. These results can be helpful for the successful treatment of patients in different regions.

scholarly journals Spectrum and theIn VitroAntifungal Susceptibility Pattern of Yeast Isolates in Ethiopian HIV Patients with Oropharyngeal Candidiasis

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Birhan Moges ◽  
Adane Bitew ◽  
Aster Shewaamare
Keyword(s):  
Antifungal Agents ◽  
Antifungal Susceptibility ◽  
Antifungal Drugs ◽  
Assay Method ◽  
Cryptococcus Laurentii ◽  
Susceptibility Pattern ◽  
Test Procedures ◽  
Disk Diffusion Assay ◽  
Diffusion Assay

Background.In Ethiopia, little is known regarding the distribution and thein vitroantifungal susceptibility profile of yeasts.Objective.This study was undertaken to determine the spectrum and thein vitroantifungal susceptibility pattern of yeasts isolated from HIV infected patients with OPC.Method.Oral pharyngeal swabs taken from oral lesions of study subjects were inoculated onto Sabouraud Dextrose Agar. Yeasts were identified by employing conventional test procedures and the susceptibility of yeasts to antifungal agents was evaluated by disk diffusion assay method.Result.One hundred and fifty-five yeast isolates were recovered of which 91 isolates were from patients that were not under HAART and 64 were from patients that were under HAART.C. albicanswas the most frequently isolated species followed byC. glabrata, C. tropicalis, C. krusei, C. kefyr, Cryptococcus laurentii, and Rhodotorulaspecies. Irrespective of yeasts isolated and identified, 5.8%, 5.8%, 12.3%, 8.4%, 0.6%, and 1.3% of the isolates were resistant to amphotericin B, clotrimazole, fluconazole, ketoconazole, miconazole, and nystatin, respectively.Conclusion.Yeast colonization rate of 69.2% and 31% resistance to six antifungal agents was documented. These highlight the need for nationwide study on the epidemiology of OPC and resistance to antifungal drugs.

Bloodstream infections caused by Magnusiomyces capitatus and Magnusiomyces clavatus: epidemiological, clinical and microbiological features of two emerging yeast species

2021 ◽  
Author(s):  
Janina Noster ◽  
Martin Köppel ◽  
Marie Desnos-Olivier ◽  
Maria Aigner ◽  
Oliver Bader ◽  
...  
Keyword(s):  
Antifungal Susceptibility ◽  
Bloodstream Infections ◽  
Its Sequencing ◽  
Intrinsic Resistance ◽  
Columbia Blood Agar ◽  
Maldi Tof ◽  
Invasive Infections ◽  
Few Data

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.

scholarly journals Hormographiella aspergillata: an emerging basidiomycete in the clinical setting? A case report and literature review

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Maxime Moniot ◽  
Rose-Anne Lavergne ◽  
Thomas Morel ◽  
Romain Guieze ◽  
Florent Morio ◽  
...  
Keyword(s):  
Antifungal Susceptibility ◽  
Diagnostic Tools ◽  
Clinical Settings ◽  
Invasive Infection ◽  
Pathogenic Potential ◽  
Short Period ◽  
Invasive Infections ◽  
In Vitro Antifungal Susceptibility ◽  
First Time

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.

scholarly journals Interpretive Breakpoints for Fluconazole and Candida Revisited: a Blueprint for the Future of Antifungal Susceptibility Testing

2006 ◽  
Vol 19 (2) ◽  
pp. 435-447 ◽  
Author(s):  
M. A. Pfaller ◽  
D. J. Diekema ◽  
D. J. Sheehan
Keyword(s):  
Clinical Studies ◽  
Randomized Clinical Trials ◽  
Clinical Laboratory ◽  
Antifungal Susceptibility ◽  
Strong Relationship ◽  
National Committee ◽  
Disk Diffusion Testing ◽  
Invasive Infections

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.

scholarly journals Antifungal Susceptibility of Dermatophytes Isolated From Cutaneous Fungal Infections: The Vietnamese Experience

2019 ◽  
Vol 7 (2) ◽  
pp. 247-249
Author(s):  
Chau Van Tro ◽  
Khuong Ho Thi Ngoc ◽  
Thuong Nguyen Van ◽  
Khang Tran Hau ◽  
Marco Gandolfi ◽  
...  
Keyword(s):  
Fungal Infections ◽  
Antifungal Susceptibility ◽  
Antifungal Drugs ◽  
Broth Microdilution ◽  
Direct Examination ◽  
Sensitivity Testing ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Vietnamese Population

AIM: Evaluate the resistance of dermatophytes to systemic antifungal drugs in the Vietnamese population. METHODS: We enrolled 101 patients with cutaneous dermatophytosis at the Dermato-Venereology hospital in HCMC from August 2016 to March 2017. All the specimens were subjected to direct examination (10% KOH mount) and culture on Sabouraud dextrose agar. In vitro antifungal sensitivity testing was done on species isolated from a culture with broth microdilution method. RESULTS: Direct microscopy was positive for dermatophytes in all patients. However this pathogen was found in fungal cultures in only 61.38% of patients. The main causative agent isolated was Trichophyton spp. (90.3%), followed by Microsporum spp. (8%) and Epidermophyton spp. (1.7%). Trichophyton spp. Has shown resistance to fluconazole, griseofulvin, ketoconazole, and itraconazole in 92.9%, 46.4%, 5.4% and 1.8% of strains, respectively. All Microsporum spp. Strains were found resistant to fluconazole and griseofulvin while resistance to ketoconazole was demonstrated in only 20% of strains and none of them was resistant to itraconazole. Epidermophyton spp strains were all resistant to fluconazole, griseofulvin, ketoconazole while none of them was resistant to itraconazole. CONCLUSION: Based upon our results, Itraconazole shows the greatest probability of efficacy in the treatment of cutaneous dermatophytosis in Vietnamese patients.

scholarly journals Regional Differences in Antifungal Susceptibility of the Prevalent Dermatophyte Trichophyton rubrum

2020 ◽  
Vol 186 (1) ◽  
pp. 53-70
Author(s):  
Y. Jiang ◽  
W. Luo ◽  
P. E. Verweij ◽  
Y. Song ◽  
B. Zhang ◽  
...  
Keyword(s):  
Trichophyton Rubrum ◽  
Antifungal Susceptibility ◽  
Sensu Stricto ◽  
Antifungal Drugs ◽  
Primary Therapy ◽  
In Vitro Susceptibility ◽  
Minimal Inhibitory Concentrations ◽  
Upper Limits ◽  
In Vitro Susceptibility Testing

AbstractIn vitro susceptibility testing for Trichophyton rubrum has shown resistance to terbinafine, azoles and amorolfine, locally, but epidemiological cutoffs are not available. In order to assess the appropriateness of current first-line antifungal treatment for T. rubrum in China, we characterized antifungal susceptibility patterns of Chinese T. rubrum strains to nine antifungals and also described the upper limits of wild-type (WT) minimal inhibitory concentrations (MIC) (UL-WT) based on our study and another six studies published during the last decades. Sixty-two clinical isolates originating from seven provinces in China were identified as T. rubrum sensu stricto; all Chinese strains showed low MICs to eight out of nine antifungal drugs. Terbinafine (TBF) showed the lowest MICs of all antifungal classes tested in both the Chinese and global groups, with a 97.5% UL-WT MIC-value of 0.03 mg/L. No non-WT isolates were observed for TBF in China, but were reported in 18.5% of the global group. Our study indicated that TBF was still the most active drug for Chinese T. rubrum isolates, and all strains were within the WT-population. TBF therefore remains recommended for primary therapy to dermatophytosis caused by T. rubrum in China now, but regular surveillance of dermatophytes and antifungal susceptibility is recommended.

3'end maturation of the Chlamydomonas reinhardtii chloroplast atpB mRNA is a two-step process

1993 ◽  
Vol 13 (4) ◽  
pp. 2277-2285
Author(s):  
D B Stern ◽  
K L Kindle
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Higher Plants ◽  
Transcription Termination ◽  
Protein Coding ◽  
Coding Regions ◽  
In Vitro Processing ◽  
Mrna Precursor ◽  
Chloroplast Transcripts

Inverted repeat (IR) sequences are found at the 3' ends of most chloroplast protein coding regions, and we have previously shown that the 3'IR is important for accumulation of atpB mRNA in Chlamydomonas reinhardtii (D. B. Stern, E.R. Radwanski, and K. L. Kindle, Plant Cell 3:285-297, 1991). In vitro studies indicate that 3' IRs are inefficient transcription termination signals in higher plants and have furthermore defined processing activities that act on the 3' ends of chloroplast transcripts, suggesting that most chloroplast mRNAs are processed at their 3' ends in vivo. To investigate the mechanism of 3' end processing in Chlamydomonas reinhardtii chloroplasts, the maturation of atpB mRNA was examined in vitro and in vivo. In vitro, a synthetic atpB mRNA precursor is rapidly cleaved at a position 10 nucleotides downstream from the mature 3' terminus. This cleavage is followed by exonucleolytic processing to generate the mature 3' end. In vivo run-on transcription experiments indicate that a maximum of 50% of atpB transcripts are transcriptionally terminated at or near the IR, while the remainder are subject to 3' end processing. Analysis of transcripts derived from chimeric atpB genes introduced into Chlamydomonas chloroplasts by biolistic transformation suggests that in vivo processing and in vitro processing occur by similar or identical mechanisms.

scholarly journals Evolutionary Transition toward Defective RNAs That Are Infectious by Complementation

2004 ◽  
Vol 78 (21) ◽  
pp. 11678-11685 ◽  
Author(s):  
Juan García-Arriaza ◽  
Susanna C. Manrubia ◽  
Miguel Toja ◽  
Esteban Domingo ◽  
Cristina Escarmís
Keyword(s):  
Rna Virus ◽  
Foot And Mouth Disease ◽  
Experimental System ◽  
Evolutionary Transition ◽  
Protein Coding ◽  
Coding Regions ◽  
Defective Rnas ◽  
Viral Particles ◽  
Mouth Disease Virus

ABSTRACT Passage of foot-and-mouth disease virus (FMDV) in cell culture resulted in the generation of defective RNAs that were infectious by complementation. Deletions (of nucleotides 417, 999, and 1017) mapped in the L proteinase and capsid protein-coding regions. Cell killing followed two-hit kinetics, defective genomes were encapsidated into separate viral particles, and individual viral plaques contained defective genomes with no detectable standard FMDV RNA. Infection in the absence of standard FMDV RNA was achieved by cotransfection of susceptible cells with transcripts produced in vitro from plasmids encoding the defective genomes. These results document the first step of an evolutionary transition toward genome segmentation of an unsegmented RNA virus and provide an experimental system to compare rates of RNA progeny production and resistance to enhanced mutagenesis of a segmented genome versus its unsegmented counterpart.

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