Species Distinction in theTrichophyton rubrumComplex

ABSTRACTTheTrichophyton rubrumspecies complex comprises commonly encountered dermatophytic fungi with a worldwide distribution. The members of the complex usually have distinct phenotypes in culture and cause different clinical symptoms, despite high genome similarity. In order to better delimit the species within the complex, molecular, phenotypic, and physiological characteristics were combined to reestablish a natural species concept. Three groups,T. rubrum,T. soudanense, andT. violaceum, could be distinguished based on the sequence of the internal transcribed spacer (ITS) ribosomal DNA barcode gene. On average, strains within each group were similar by colony appearance, microscopy, and physiology, but strains between groups showed significant differences.Trichophyton rubrumstrains had higher keratinase activity, whereasT. violaceumstrains tended to be more lipophilic; however, none of the phenotypic features were diagnostic. The results of matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) and amplified fragment length polymorphism (AFLP) were partially consistent with the ITS data but failed to distinguish the species unambiguously. Despite their close similarity,T. violaceum,T. soudanense, andT. rubrumcan be regarded as independent species with distinct geographical distributions and clinical predilections.Trichophyton soudanenseis pheno- and genotypically intermediate betweenT. rubrumandT. violaceum. For routine diagnostics, ITS sequencing is recommended.

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Posttreatment Antifungal Resistance among Colonizing Candida Isolates in Candidemia Patients: Results from a Systematic Multicenter Study

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01763-15 ◽

2015 ◽

Vol 60 (3) ◽

pp. 1500-1508 ◽

Cited By ~ 28

Author(s):

R. H. Jensen ◽

H. K. Johansen ◽

L. M. Søes ◽

L. E. Lemming ◽

F. S. Rosenvinge ◽

...

Keyword(s):

Genetic Relatedness ◽

Acquired Resistance ◽

Antifungal Drugs ◽

Its Sequencing ◽

Ionization Time ◽

Content Type ◽

Flight Mass Spectrometry ◽

Echinocandin Resistance ◽

Resistance Rates ◽

Initial Blood

The prevalence of intrinsic and acquired resistance among colonizingCandidaisolates from patients after candidemia was investigated systematically in a 1-year nationwide study. Patients were treated at the discretion of the treating physician. Oral swabs were obtained after treatment. Species distributions and MIC data were investigated for blood and posttreatment oral isolates from patients exposed to either azoles or echinocandins for <7 or ≥7 days. Species identification was confirmed using matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) and internal transcribed spacer (ITS) sequencing, susceptibility was examined by EUCAST EDef 7.2 methodology, echinocandin resistance was examined byFKSsequencing, and genetic relatedness was examined by multilocus sequence typing (MLST). One hundred ninety-three episodes provided 205 blood and 220 oral isolates. MLST analysis demonstrated a genetic relationship for 90% of all paired blood and oral isolates. Patients exposed to azoles for ≥7 days (n= 93) had a significantly larger proportion of species intrinsically less susceptible to azoles (particularlyCandida glabrata) among oral isolates than among initial blood isolates (36.6% versus 12.9%;P< 0.001). A similar shift toward species less susceptible to echinocandins among 85 patients exposed to echinocandins for ≥7 days was not observed (4.8% of oral isolates versus 3.2% of blood isolates;P> 0.5). Acquired resistance inCandida albicanswas rare (<5%). However, acquired resistance to fluconazole (29.4%;P< 0.05) and anidulafungin (21.6%;P< 0.05) was common inC. glabrataisolates from patients exposed to either azoles or echinocandins. Our findings suggest that the colonizing mucosal microbiota may be an unrecognized reservoir of resistantCandidaspecies, especiallyC. glabrata, following treatment for candidemia. The resistance rates were high, raising concern in general for patients exposed to antifungal drugs.

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Clostridium ramosum rapidly identified by MALDI-TOF MS. A rare gram-variable agent of bacteraemia.

Access Microbiology ◽

10.1099/acmi.0.000137 ◽

2020 ◽

Vol 2 (8) ◽

Author(s):

M.C. Legaria ◽

S.D. García ◽

V. Tudanca ◽

C. Barberis ◽

L. Cipolla ◽

...

Keyword(s):

Type Species ◽

Clinical Symptoms ◽

Gc Content ◽

Ionization Time ◽

Content Type ◽

Maldi Tof Ms ◽

Link Type ◽

Maldi Tof ◽

Flight Mass Spectrometry ◽

Tof Ms

Clostridium ramosum is an enteric anaerobic, endospore-forming, gram-positive rod with a low GC content that is rarely associated with disease in humans. We present a case of C. ramosum bacteraemia. To the best of our knowledge, this is the second case of C. ramosum bacteraemia in an elderly patient presenting with fever, abdominal pain and bilious emesis. We highlight the Gram stain variability, the lack of visualization of spores and the atypical morphology of the colonies that showed C. ramosum in a polymicrobial presentation that initially appeared to show monomicrobial bacteraemia. The microorganism was rapidly identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). We present a comprehensive literature review of 32 cases of clinical infections by C. ramosum in which we describe, if available, sex, age, clinical symptoms, predisposing conditions, other organisms present in the blood culture, other samples with C. ramosum , identification methodology, treatment and outcome.

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Degradation of Incretins and Modulation of Blood Glucose Levels by Periodontopathic Bacterial Dipeptidyl Peptidase 4

Infection and Immunity ◽

10.1128/iai.00277-17 ◽

2017 ◽

Vol 85 (9) ◽

Cited By ~ 9

Author(s):

Yuko Ohara-Nemoto ◽

Manami Nakasato ◽

Yu Shimoyama ◽

Tomomi T. Baba ◽

Takeshi Kobayakawa ◽

...

Keyword(s):

Diabetes Mellitus ◽

Blood Glucose ◽

Dipeptidyl Peptidase ◽

Oral Glucose ◽

Content Type ◽

Dipeptidyl Peptidase 4 ◽

Glucose Levels ◽

Flight Mass Spectrometry ◽

Blood Glucose Levels ◽

Molecular Events

ABSTRACT Severe periodontitis is known to aggravate diabetes mellitus, though molecular events related to that link have not been fully elucidated. Porphyromonas gingivalis, a major pathogen of periodontitis, expresses dipeptidyl peptidase 4 (DPP4), which is involved in regulation of blood glucose levels by cleaving incretins in humans. We examined the enzymatic characteristics of DPP4 from P. gingivalis as well as two other periodontopathic bacteria, Tannerella forsythia and Prevotella intermedia, and determined whether it is capable of regulating blood glucose levels. Cell-associated DPP4 activity was found in those microorganisms, which was effectively suppressed by inhibitors of human DPP4, and molecules sized 73 kDa in P. gingivalis, and 71 kDa in T. forsythia and P. intermedia were immunologically detected. The k cat/Km values of recombinant DPP4s ranged from 721 ± 55 to 1,283 ± 23 μM−1s−1 toward Gly-Pro-4-methylcoumaryl-7-amide (MCA), while those were much lower for His-Ala-MCA. Matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) analysis showed His/Tyr-Ala dipeptide release from the N termini of incretins, glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide, respectively, with the action of microbial DPP4. Moreover, intravenous injection of DPP4 into mice decreased plasma active GLP-1 and insulin levels, accompanied by a substantial elevation in blood glucose over the control after oral glucose administration. These results are the first to show that periodontopathic bacterial DPP4 is capable of modulating blood glucose levels the same as mammalian DPP4; thus, the incidence of periodontopathic bacteremia may exacerbate diabetes mellitus via molecular events of bacterial DPP4 activities.

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Effect of Fluorescent Dyes onIn Vitro-Differentiated, Late-Stage Plasmodium falciparum Gametocytes

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.03772-14 ◽

2014 ◽

Vol 58 (12) ◽

pp. 7398-7404 ◽

Cited By ~ 14

Author(s):

Tamirat Gebru ◽

Benjamin Mordmüller ◽

Jana Held

Keyword(s):

Plasmodium Falciparum ◽

Late Stage ◽

Fluorescent Dyes ◽

Clinical Symptoms ◽

Laboratory Strain ◽

Clinical Isolates ◽

Synthetic Dyes ◽

Content Type ◽

Highly Active

ABSTRACTPlasmodium falciparumgametocytes are not associated with clinical symptoms, but they are responsible for transmitting the pathogen to mosquitoes. Therefore, gametocytocidal interventions are important for malaria control and resistance containment. Currently available drugs and vaccines are not well suited for that purpose. Several dyes have potent antimicrobial activity, but their use against gametocytes has not been investigated systematically. The gametocytocidal activity of nine synthetic dyes and four control compounds was tested against stage V gametocytes of the laboratory strain 3D7 and three clinical isolates ofP. falciparumwith a bioluminescence assay. Five of the fluorescent dyes had submicromolar 50% inhibitory concentration (IC50) values against mature gametocytes. Three mitochondrial dyes, MitoRed, dihexyloxacarbocyanine iodide (DiOC6), and rhodamine B, were highly active (IC50s < 200 nM). MitoRed showed the highest activity against gametocytes, with IC50s of 70 nM against 3D7 and 120 to 210 nM against clinical isolates. All compounds were more active against the laboratory strain 3D7 than against clinical isolates. In particular, the endoperoxides artesunate and dihydroartemisinin showed a 10-fold higher activity against 3D7 than against clinical isolates. In contrast to all clinically used antimalarials, several fluorescent dyes had surprisingly highin vitroactivity against late-stage gametocytes. Since they also act against asexual blood stages, they shall be considered starting points for the development of new antimalarial lead compounds.

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Coagulopathy with the use of hetastarch in the treatment of vasospasm

Journal of Neurosurgery ◽

10.3171/jns.1995.82.1.0044 ◽

1995 ◽

Vol 82 (1) ◽

pp. 44-47 ◽

Cited By ~ 61

Author(s):

Eric R. Trumble ◽

J. Paul Muizelaar ◽

John S. Myseros ◽

Sung C. Choi ◽

Brian B. Warren

Keyword(s):

Volume Expansion ◽

Clinical Symptoms ◽

Standard Of Care ◽

The Other ◽

Appropriate Use ◽

Content Type ◽

Prevention And Treatment ◽

Plasma Protein Fraction ◽

Clinically Significant ◽

Fine Print

✓ The use of colloid agents to achieve hypervolemia in the prevention and treatment of postsubarachnoid hemorrhage (post-SAH) vasospasm is included in the standard of care at many institutions. Risk profiles are necessary to ensure appropriate use of these agents. In a series of 85 patients with recent aneurysmal SAH, 26 developed clinical symptoms of vasospasm. Fourteen of the 26 were treated with hetastarch for volume expansion while the other 12 received plasma protein fraction (PPF). Clinically significant bleeding pathologies were noted in six patients who received hetastarch as a continuous intravenous infusion. Hetastarch increased partial thromboplastin time from a mean of 23.9 seconds to a mean of 33.1 seconds (p < 0.001) in all patients who received infusions of this agent, while no effect was noted in the 12 patients who received PPF infusions. No other coagulation parameters were altered. This study shows an increase in coagulopathy with the use of hetastarch as compared with the use of PPF for the treatment of postaneurysmal vasospasm.

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Molecular diagnosis and source tracing of an infection of Aureobasidium pullulans

The Journal of Infection in Developing Countries ◽

10.3855/jidc.11830 ◽

2019 ◽

Vol 13 (12) ◽

pp. 1174-1179

Author(s):

Dongli Liu ◽

Lin Ma ◽

Yi Shi ◽

Anli Wang ◽

Changhong Liu

Keyword(s):

Bone Marrow ◽

Aureobasidium Pullulans ◽

Clinical Symptoms ◽

Universal Primers ◽

Molecular Diagnostic ◽

Recurrent Fever ◽

Living Room ◽

Its Sequence ◽

Suspected Case ◽

Its Sequencing

Aureobasidium pullulans (A. pullulans) is a dematiaceous, yeast-like fungus that is ubiquitous in nature, which can colonize the human hair and skin. A. pullulans has been clinically implicated to cause skin and soft tissue infections, meningitis, splenic abscesses, and peritonitis. Herein, molecular diagnostic of internal transcribed spacer (ITS) sequencing was used to investigate a suspected case of A. pullulans infection, and the infection source had been traced. A 27-year-old female case was suspected of kala-azar due to the recurrent fever. Bone marrow specimens were analyzed. The samples were negative for Leishmania, Penicillium marneffei and Histoplasma capsulatum. DNA was extracted from the bone marrow specimens, and the 583-bp sequence was amplified with the fungal ITS universal primers. The sequence was compared by Blast query to be identified as A. pullulans. A strain of A. pullulans was also isolated from the kitchen of the patient’s living room. Culture characteristics were the same as the human pathogens of A. pullulans, and the ITS sequence was identical to the bone marrow ITS amplification. In conclusion, a deep infection caused by A. pullulans is rare, often occurring in the indwelling catheter, which may cause peritonitis and other symptoms. ITS sequencing of fungi can be used as a diagnostic reference. As A. pullulans is a common fungus in environment, amplification of ITS sequence of A. pullulans in the aseptic body fluid would be necessary to make a comprehensive diagnosis based on the clinical symptoms and signs.

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Reversible hearing loss associated with a malignant pineal germ cell tumor

Journal of Neurosurgery ◽

10.3171/jns.2003.99.3.0587 ◽

2003 ◽

Vol 99 (3) ◽

pp. 587-590 ◽

Cited By ~ 7

Author(s):

Nathalie Gaspar ◽

Arnauld Verschuur ◽

Ghislaine Mercier ◽

Dominique Couanet ◽

Christian Sainte-Rose ◽

...

Keyword(s):

Hearing Loss ◽

Germ Cell ◽

Germ Cell Tumor ◽

Clinical Symptoms ◽

Tumor Regression ◽

Cell Tumor ◽

Direct Compression ◽

Pineal Tumors ◽

Content Type ◽

Adjacent Structures

✓ In patients with pineal tumors, clinical symptoms are due to direct compression of adjacent structures. The most common signs include increased intracranial pressure (80%) caused by obstruction of the sylvian aqueduct, and Parinaud syndrome (50%) caused by direct compression of the superior colliculi. Hearing loss is rare in patients with tumors in this location. The authors report on the case of a 12-year-old boy in whom a malignant pineal germ cell tumor was found together with the unusual occurrence of severe hearing loss due to direct bilateral compression of the inferior colliculi. This condition resolved completely after tumor regression.

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Staphylococcus singaporensis sp. nov., a new member of the Staphylococcus aureus complex, isolated from human clinical specimens

INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY ◽

10.1099/ijsem.0.005067 ◽

2021 ◽

Vol 71 (10) ◽

Author(s):

Ka Lip Chew ◽

Sophie Octavia ◽

Deborah Lai ◽

Raymond T. P. Lin ◽

Jeanette W. P. Teo

Keyword(s):

Staphylococcus Aureus ◽

Type Species ◽

Clinical Laboratory ◽

Core Gene ◽

Separate Species ◽

New Members ◽

Content Type ◽

Link Type ◽

Flight Mass Spectrometry ◽

Genotypic Analysis

Staphylococcus argenteus and Staphylococcus schweitzeri are the newest members of the Staphylococcus aureus complex. The number of clinical reports attributed to these new S. aureus complex members is limited. In a retrospective clinical laboratory study conducted over a 4-month period investigating the prevalence of S. argenteus and S. schweitzeri , a total of 43 isolates were selected. Phylogeny based on core-gene multilocus sequence typing (MLST) analysis confirmed that 37 were S. argenteus but a genetically distinct clade of six isolates was identified. Digital DNA–DNA hybridization (dDDH) and average nucleotide identity (ANI) analyses further supported the classification of these six isolates as a separate species. When compared to S. aureus complex reference genomes, the ANI values were ≤94 % and the dDDH values were <53 %. Based on the seven-gene S. aureus MLST scheme, the six isolates belong to five novel allelic profiles (ST6105, ST6106, ST6107, ST6108 and ST109). Their clinical infection features were similar to S. aureus . Skin and soft tissue infections presented in four out of the six cases. Routine clinical diagnostic identification using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and biochemical profiling does not differentiate these new members from the rest of the complex. Genotypic analysis suggests that the six isolates belong to a novel species, Staphylococcus singaporensis sp. nov. with isolate SS21T (=DSM 111408T=NCTC14419T) designated as the type strain.

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Ciclopirox and Efinaconazole Transungual Permeation, Antifungal Activity, and Proficiency To Induce Resistance in Trichophyton rubrum

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00442-19 ◽

2019 ◽

Vol 63 (10) ◽

Cited By ~ 7

Author(s):

Daniela Monti ◽

Diletta Mazzantini ◽

Silvia Tampucci ◽

Alessandra Vecchione ◽

Francesco Celandroni ◽

...

Keyword(s):

Antifungal Activity ◽

Trichophyton Rubrum ◽

Nail Plate ◽

Content Type ◽

Nail Bed ◽

Antimycotic Activity ◽

Frequent Relapses ◽

Induce Resistance ◽

Over Time

ABSTRACT Onychomycosis is a nail fungal infection, mostly caused by dermatophytes. The treatment efficacy is impaired by difficulties of reaching effective drug levels at the site of infection; frequent relapses occur after cessation of antifungal therapy. The aim of the study was to compare two commercial products containing ciclopirox or efinaconazole for antimycotic activity and antifungal drug resistance. A study of permeation and penetration through bovine hoof membranes, as a nail model, was performed to evaluate the antimycotic activity of permeates against clinical isolates of selected fungi, and the frequency of spontaneous in vitro Trichophyton rubrum-resistant strains was assessed by broth microdilution assays. The results suggest that ciclopirox creates a depot in the nail, leading to a gradual release of the drug over time with action on both the nail plate and bed. Conversely, efinaconazole, mildly interacting with nail keratin, mainly exerts its antifungal activity in the nail bed. However, in the case of T. rubrum, the antifungal activities of the drugs in the nail plate seem comparable. Finally, efinaconazole showed a potential for induction of resistance in T. rubrum, which may limit its efficacy over time. Ciclopirox did not show any potential to induce resistance in T. rubrum and appears endowed with a more complete activity than efinaconazole in the management of onychomycosis as the nail keratin is a substrate for the growth of fungal cells, and the availability of drug in large concentration just in the nail bed may not be sufficient to guarantee the complete eradication of pathogens.

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Molecular Taxonomy of the Trichophyton rubrum Complex

Journal of Clinical Microbiology ◽

10.1128/jcm.38.9.3329-3336.2000 ◽

2000 ◽

Vol 38 (9) ◽

pp. 3329-3336 ◽

Cited By ~ 106

Author(s):

Y. Gräser ◽

A. F. A. Kuijpers ◽

W. Presber ◽

G. S. de Hoog

Keyword(s):

Length Polymorphism ◽

Fragment Length ◽

Internal Transcribed Spacer ◽

Fragment Length Polymorphism ◽

Trichophyton Rubrum ◽

Molecular Taxonomy ◽

Polymorphism Analysis ◽

Internal Transcribed Spacer Region ◽

Trichophyton Soudanense ◽

Ribosomal Operon

The validity of taxa around Trichophyton rubrum was evaluated by a combination of phenetic and molecular methods. Morphological and physiological features were compared to results of sequencing of the internal transcribed spacer region of the ribosomal operon, PCR fingerprinting, and amplified fragment length polymorphism analysis. The 15 species and varieties investigated (Trichophyton circonvolutum, Trichophyton fischeri,Trichophyton fluviomuniense, Trichophyton glabrum, Trichophyton gourvilii, Trichophyton kanei, Trichophyton kuryangei, Trichophyton megninii, Trichophyton pedis, Trichophyton raubitschekii, Trichophyton rodhaini,Trichophyton rubrum var. nigricans,Trichophyton soudanense, Trichophyton violaceumvar. indicum, and Trichophyton yaoundei) were reclassified or synonymized as T. rubrum or T. violaceum.

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