[Show abstract][Hide abstract] ABSTRACT: The Achromobacter is a genus in the family Alcaligenaceae, comprising fifteen species isolated from different sources, including clinical samples. The ability to detect and correctly identify Achromobacter species, particularly A. xylosoxidans, and differentiate them from other phenotypically similar and genotypically related Gram-negative, aerobic, non-fermenting species is important for patients with cystic fibrosis (CF), as well as for nosocomial and other opportunistic infections. Traditional phenotypic profile-based analyses have been demonstrated to be inadequate for reliable identifications of isolates of Achromobacter species and genotypic-based assays, relying upon comparative 16S rRNA gene sequence analyses are not able to insure definitive identifications of Achromobacter species, due to the inherently conserved nature of the gene. The uses of alternative methodologies to enable high-resolution differentiation between the species in the genus are needed. A comparative multi-locus sequence analysis (MLSA) of four selected 'house-keeping' genes (atpD, gyrB, recA, and rpoB) assessed the individual gene sequences for their potential in developing a reliable, rapid and cost-effective diagnostic protocol for Achromobacter species identifications. The analysis of the type strains of the species of the genus and 46 strains of Achromobacter species showed congruence between the cluster analyses derived from the individual genes. The MLSA gene sequences exhibited different levels of resolution in delineating the validly published Achromobacter species and elucidated strains that represent new genotypes and probable new species of the genus. Our results also suggested that the recently described A. spritinus is a later heterotypic synonym of A. marplatensis. Strains were analyzed, using whole-cell Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight mass spectrometry (MALDI-TOF MS), as an alternative phenotypic profile-based method with the potential to support the identifications determined by the genotypic DNA sequence-based MLSA. The MALDI-TOF MS data showed good accordance in strain groupings and identifications by the MLSA data.
[Show abstract][Hide abstract] ABSTRACT: In Germany, infections due to the zoophilic dermatophyte Trichophyton (T.) species of Arthroderma benhamiae are being more frequently diagnosed. The source of infection of this emerging pathogen overlaps with that of the zoophilic species T. interdigitale. The most common source are guinea pigs. T. species of Arthroderma benhamiae causes inflammatory dermatophytosis in children and adolescents. In addition to tinea capitis, it may cause both tinea corporis, tinea manus and frequently tinea faciei. In Germany, T. species of Arthroderma benhamiae is a frequent zoophilic dermatophyte, which in regions is probably more frequent than Microsporum canis. The mycological identification of the isolates with their yellow stained colonies is based on their macroscopic and microscopic features. However, some exhibit colony features consistent with those of T. interdigitale. These strains only can be identified unambiguously by means of molecular techniques. Using detection methods such as PCR-ELISA or real-time PCR, the dermatophyte can be identified directly from clinical material. Sequencing of the internal transcribed spacer region (ITS) of the ribosomal DNA has been approved as culture confirmation test for T. species of Arthroderma benhamiae. In addition, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI TOF MS) is useful. Widespread dermatophytosis due to T. species of Arthroderma benhamiae, in particular of tinea capitis, requires oral antifungal agents. Terbinafine is most effective, alternatives are fluconazole and itraconazole.
Full-text · Article · Jul 2014 · Journal der Deutschen Dermatologischen Gesellschaft
[Show abstract][Hide abstract] ABSTRACT: ZusammenfassungIn Deutschland kommen seit einigen Jahren Infektionen durch den zoophilen Dermatophyten Trichophyton (T.) Spezies von Arthroderma benhamiae vor. Das Reservoir für diesen neuen Erreger – ein emerging pathogen – überlappt mit dem des zoophilen T. interdigitale. Insbesondere Meerschweinchen sind Carrier. T. Spezies von Arthroderma benhamiae verursacht eine entzündliche Tinea bei Kindern und Jugendlichen. Neben der Tinea capitis werden Tinea corporis und Tinea manus verursacht, vor allem jedoch die Tinea faciei. T. Spezies von Arthroderma benhamiae ist in Deutschland ein häufiger zoophiler Dermatophyt, in manchen Regionen häufiger als Microsporum canis. Die Identifizierung der Isolate mit gelb gefärbten Kolonien ist anhand makro- und mikroskopischer Merkmale möglich. Ein Teil der Isolate weist jedoch Koloniemerkmale auf, welche mit denen von T. interdigitale übereinstimmen. Diese Stämme lassen sich nur mittels molekularer Methoden identifizieren. Mit einem PCR-ELISA oder real-time PCR kann der Dermatophyt direkt im klinischen Material nachgewiesen werden. Als Kulturbestätigungstest hat sich die Sequenzierung der internal transcribed spacer Region (ITS) der ribosomalen DNA bewährt. Auch die matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI TOF MS) ist dafür geeignet. Die Behandlung von ausgedehnten Dermatophytosen durch T. Spezies von Arthroderma benhamiae, insbesondere der Tinea capitis, erfolgt mit oralen Antimykotika, am besten Terbinafin; Alternativen sind Fluconazol und Itraconazol.
Full-text · Article · Jul 2014 · Journal der Deutschen Dermatologischen Gesellschaft
[Show abstract][Hide abstract] ABSTRACT: In the present study 13 Arcanobacterium pluranimalium strains isolated from various animal origin could successfully be identified phenotypically by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and genotypically by sequencing 16S rDNA and the pluranimaliumlysin encoding gene pla. The detection of mass spectra by MALDI-TOF MS and the novel genotypic approach using gene pla might help to identify A. pluranimalium in future and might elucidate the role this species plays in infections of animals.
Full-text · Article · Nov 2013 · Veterinary Microbiology
[Show abstract][Hide abstract] ABSTRACT: In the present study four Trueperella (T.) abortisuis strains isolated from an umbilical swab, two anal swabs and from a placenta after abortion of four pigs, respectively, could successfully be identified phenotypically, by MALDI-TOF MS analysis and genotypically by amplification and sequencing of 16S rRNA gene sequence and gene sodA encoding superoxide dismutase A as additional molecular target. All four T. abortisuis were isolated together with various other bacterial species indicating that the pathogenic importance of this novel species remains unclear. However, according to the literature and to the results of the present study T. abortisuis could be recovered from samples of animals in Japan and in different microbiological laboratories in Germany emphasizing its increasing importance.
No preview · Article · Nov 2013 · Berliner und Münchener tierärztliche Wochenschrift
[Show abstract][Hide abstract] ABSTRACT: Altogether 285 dermatophyte isolates of 21 different species - including both Trichophyton rubrum and T. interdigitale, but also eight additional Trichophyton species, Microsporum canis and seven other Microsporum species, as well as Epidermophyton floccosum and Arthroderma spp. - were analyzed using Matrix Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) and the AnagnosTec 'SARAMIS' (Spectral Archiving and Microbial Identification System) software. In addition, sequence analysis of the internal transcribed spacer (ITS) of the ribosomal DNA was performed for a high number of the tested strains. Sufficient agreement was found between the results obtained with standard identification methods and those with the MALDI-TOF MS for species identification of dermatophytes. A mass spectra database was constructed which contained the species identifications of all 285 isolates. The results were confirmed for 164 of the isolates by sequence analysis of the internal transcribed spacer (ITS) of the ribosomal DNA. Statistical analysis of all 285 dermatophyte strains showed that conventional identification matched the results of MALDI-TOF MS for 78.2% of the isolates tested. In the case of the 164 isolates for which the identifications were confirmed by PCR, the results of their conventional diagnosis and MALDI-TOF MS were in agreement for only 68.9 % (113 of 164 strains) of the test isolates. In contrast, there was agreement of 99.3 % or 98.8 % in the identifications obtained with PCR and MALDI-TOF MS techniques (283/285 or 162/164). The two exceptions were isolates that proved to be T. violaceum which could not be identified by the MALDI-TOF MS technique. In conclusion, the MALDI-TOF mass spectroscopy represents a fast and very specific method for species differentiation of dermatophytes grown in culture.
Full-text · Article · May 2012 · Medical mycology: official publication of the International Society for Human and Animal Mycology
[Show abstract][Hide abstract] ABSTRACT: In the present study a Trueperella (Arcanobacterium) bernardiae strain isolated from an anal swab of a three-day-old piglet could be identified phenotypically, by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and genotypically by sequencing the 16S rDNA, the 16S-23S rDNA intergenic spacer region (ISR) and by sequencing the superoxide dismutase A encoding gene sodA. The present study gives the first information about the presence of T. (A.) bernardiae in specimen of animals.
No preview · Article · Apr 2012 · Veterinary Microbiology
[Show abstract][Hide abstract] ABSTRACT: Clinical microbiology is a conservative laboratory exercise where base technologies introduced in the 19th century remained
essentially unaltered. High-tech mass spectrometry (MS) has changed that. Within a few years following its adaptation to microbiological
diagnostics, MS has been introduced, embraced, and broadly accepted by clinical microbiology laboratories throughout the world
as an innovative tool for definitive bacterial species identification. Herein, we review the current state of the art with
respect to this exciting new technology and discuss potential future applications.
Full-text · Article · Feb 2012 · Journal of clinical microbiology
[Show abstract][Hide abstract] ABSTRACT: Some members of the genus Candida are among the most common human fungal pathogens and cause serious diseases especially in immunocompromised people. A yeast was isolated from a blood culture from an immunocompromised cancer patient who suffered from acute pneumonia. The growth characteristics of the yeast on CHROMagar Candida were similar to those of Candida tropicalis, whereas the API ID 32C system identified the yeast as Candida silvicola. On the basis of the nucleotide divergence in the D1/D2 domain of the 26S nuclear rRNA (nrRNA) gene, as well as the internal transcribed spacer (ITS) domain of the nrRNA gene region, a new species, Candida pseudoaaseri sp. nov. with type strain VK065094 (CBS 11170(T)), which was found to be closely related to Candida aaseri, is proposed. While C. aaseri strains were susceptible to all tested antifungals, the new species is resistant to flucytosine and may also be distinguished from C. aaseri by its ability to assimilate l-rhamnose, whereas its colony morphology on CHROMagar Candida may be helpful for differentiation.
Full-text · Article · Dec 2011 · Journal of clinical microbiology
[Show abstract][Hide abstract] ABSTRACT: Species identification of yeasts is based on biochemical (e.g. API ID 32 C®, bioMérieux) and molecular biological approaches. As an alternative to DNA-dependent methods, mass spectral analysis based identification of micro-organisms has become increasingly recognized. In a number of studies, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been applied for the rapid classification and identification of micro-organisms. In this study, the applicability of MALDI-TOF MS for identifying yeasts isolated from dermatological patients was analysed and compared with the results from the API ID 32 C® system. Furthermore, sequencing the internal transcribed spacer (ITS) regions of the ribosomal DNA was employed as reference method. Candida (C.) albicans was isolated in 41.9% of all cases, C. parapsilosis in 20.3%, C. glabrata in 10.8%, and C. krusei in 6, 8.1%. Rarely isolated yeasts were Candida colliculosa, famata, guilliermondii, lusitaniae, and tropicalis as well as Geotrichum candidum, Rhodotorula mucilaginosa and Trichosporon mucoides. The MALDI TOF results were equal to the results gained by ITS sequence analysis in 94%, whereas API ID 32 C® provided the correct diagnosis in 84.3% (of all cases). This lower identification rate is mostly referable to frequent misidentifications of C. krusei as C. inconspicua/norvegensis,Candida tropicalis, or Geotrichum capitatum. In contrast, all C. krusei strains were correctly identified by MALDI TOF MS. In conclusion, species identification by MALDI-TOF MS was proven to be consistent with ITS sequence analysis; the technique has a resolving power comparatively as high as ITS sequence analysis.
[Show abstract][Hide abstract] ABSTRACT: Gram-positive anaerobic cocci (GPAC) are part of the commensal microbiota of humans and are a phylogenetically heterogeneous group of organisms. To evaluate the suitability of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) for the identification of GPAC, a database was constructed, using reference strains of commonly encountered GPAC and clinical isolates of which the sequence of the 16S rRNA gene was determined. Subsequently, the database was validated by identifying 107 clinical isolates of GPAC. Results were compared with the identifications obtained by 16S sequencing or fluorescent in situ hybridization (FISH). Strains belonging to the same species grouped together, in most cases, by MALDI-TOF MS analyses. Strains with sequence similarities less than 98% to their closest relatives, formed clusters distinct from recognized species in the MALDI-TOF MS dendrogram and, therefore could not be identified. These strains probably represent new species. Only three clinical isolates (2 strains of Finegoldia magna and 1 strain of Anaerococcus vaginalis) could not be identified. For all the other GPAC strains (96/107), reliable identifications were obtained. Therefore, we concluded that MALDI-TOF MS is an excellent tool for the identification of phylogenetically heterogeneous groups of micro-organisms such as GPAC.
Full-text · Article · Feb 2011 · Systematic and Applied Microbiology
[Show abstract][Hide abstract] ABSTRACT: The Streptococcus bovis/equinus complex is a heterogeneous group within the group D streptococci with important clinical relevance regarding infective endocarditis, sepsis and colon carcinoma. The taxonomic identification of species and sub-species of this complex, by the standard methods remains difficult. In the present study, we compared the cluster analysis of 88 strains of species of the S. bovis/equinus complex by sequence analysis of the manganese-dependent superoxide dismutase gene (sodA) and by Matrix Assisted Laser Desorption/Ionization-Time Of Flight Mass Spectrometry (MALDI-TOF MS). We observed a high congruence of strain grouping by MALDI-TOF MS in comparison with sodA sequence analyses, demonstrating the accuracy and reliability of MALDI-TOF MS in comparison to DNA sequence-based method. By generating mass spectra for each species and sub-species, we were able to discriminate all members of the S. bovis/equinus complex. Furthermore, we demonstrated reliable identifications to the species level by MALDI-TOF MS, independently of cultivation conditions.
Full-text · Article · Feb 2011 · Systematic and Applied Microbiology
[Show abstract][Hide abstract] ABSTRACT: Insgesamt sind 12 dermatologisch relevante Microsporum-(M.-)Arten bekannt. Am häufigsten werden M.
canis, M.audouinii und M.gypseum nachgewiesen. Wir berichten über eine Infektion mit dem seltenen Erreger M.
fulvum am rechten Unterarm. Zur Diagnostik wurden Schuppen von den Hautläsionen gewonnen. Mittels Nativpräparat konnte frühzeitig
eine Mykose nachgewiesen werden. Nach kultureller Anzucht wurde zunächst die Diagnose einer Infektion mit dem geophilen Erreger
gypseum vermutet, mittels ITS-Sequenzierung und Massenspektrometrie konnte schließlich M.
fulvum nachgewiesen werden.
There are 12 dermatologically relevant Microsporum (M.) species. The most frequent species are M.canis, M.audouinii and M.gypseum. We report an infection of the right forearm with the rare dermatophyte M.fulvum. A KOH examination of scales revealed a tinea corporis. The scales were cultured on Dermasel® agar with the identification
of the geophilic dermatophyte M.gypseum. However, ITS sequencing and mass spectrometry revealed M.fulvum as the correct pathogen.
-ITS sequencing-MALDI-TOF mass spectrometry-Geophilic
[Show abstract][Hide abstract] ABSTRACT: Immediately after the first MALDI-TOF instrument became available, microbiologists have been investigating its potential as a platform for high throughput identification of microorganisms. A remarkable finding very early in these investigations was that despite the dynamic nature of the bacterial cell, components of the mass spectral profile were sufficiently stable and remained unchanged in spite of changes in environmental parameters. Further, mass spectral pattern have been found to be taxon specific and thus, consequently, numerous methods were reported that purported to provide an alternative to current identification systems. The SARAMIS system described herein sequentially extracts core stable mass ions from analyses of multiple individual strains of a particular species to yield a ‘SuperSpectrum’, a list of biomarkers that are weighted according to their specificity from family to (sub)species levels. This approach has been used successfully to identify microorganisms from diverse phylogenetic lines of bacteria and fungi with considerable success. The protocol described has evolved of over years of experimental work to yield a robust system that can readily be applied for routine microbiological identification in a clinical diagnostic laboratory.
[Show abstract][Hide abstract] ABSTRACT: ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.