A novel strategy for the molecular identification of fungal agents of onychomycosis (including Trichophyton rubrum) has been designed based on the use of species-specific and universal primers in conjunction with a commercial kit that allows the extraction of DNA directly from the nail specimens. The microsatellite marker T1, which is based on a (GT)n repeat, was applied for the species-specific identification of Trichophyton rubrum. To evaluate how often Scopulariopsis spp. are detected in nail specimens, a second primer pair was designed to amplify specifically a 336-bp DNA fragment of the 28S region of the nuclear rRNA gene of S. brevicaulis and closely related species. Other fungal species were identified using amplification of the internal transcribed spacer (ITS) region of the rRNA gene, followed by restriction fragment length polymorphism analysis or sequencing. In addition, polyacrylamide gel separation of the T1-PCR product allowed subtyping of T. rubrum strains. We studied 195 nail specimens (the "nail sample") and 66 previously collected etiologic strains (the "strain sample") from 261 onychomycosis patients from Bulgaria and Greece. Of the etiologic agents obtained from both samples, T. rubrum was the most common organism, confirmed to be present in 76% of all cases and serving as the sole or (rarely) mixed etiologic agent in 199 of 218 cases (91%) where the identity of the causal organism(s) was confirmed. Other agents seen included molds (6% of cases with identified etiologic agents; mainly S. brevicaulis) and other dermatophyte species (4%; most frequently Trichophyton interdigitale). Simultaneous infections with two fungal species were confirmed in a small percentage of cases (below 1%). The proportion of morphologically identified cultures revealed by molecular study to have been misidentified was 6%. Subtyping revealed that all but five T. rubrum isolates were of the common type B that is prevalent in Europe. In comparison to microscopy and culture, the molecular approach was superior. The PCR was more sensitive (84%) than culture (22%) in the nail sample and was more frequently correct in specifically identifying etiologic agents (100%) than microscopy plus routine culture in either the nail or the strain samples (correct culture identifications in 96% and 94% of cases, respectively). Using the molecular approach, the time for diagnosing the identity of fungi causing onychomycosis could be reduced to 48 h, whereas culture techniques generally require 2 to 4 weeks. The early detection and identification of the infecting species in nails will facilitate prompt and appropriate treatment and may be an aid for the development of new antifungal agents.
Hybrid materials based on polyvinylpyrrolidone (PVP) with silver nanoparticles (AgNps) were synthesized applying two different strategies based on thermal or chemical reduction of silver ions to silver nanoparticles using PVP as a stabilizer. The formation of spherical silver nanoparticles with diameter ranging from 9 to 16 nm was confirmed by TEM analysis. UV-vis and FTIR spectroscopy were also applied to confirm the successful formation of AgNps. The antibacterial activity of the synthesized AgNPs/PVP against etalon strains of three different groups of bacteria-Staphylococcus aureus (S. aureus; grampositive bacteria), Escherichia coli (E. coli; gram-negative bacteria), Pseudomonas aeruginosa (P. aeruginosa; nonferment gram-negative bacteria), as well as against spores of Bacillus subtilis (B. subtilis) was studied. AgNps/PVP were tested for the presence of fungicidal activity against different yeasts and mold such as Candida albicans, Candida krusei, Candida tropicalis, Candida glabrata, and Aspergillus brasiliensis. The hybrid materials showed a strong antimicrobial effect against the tested bacterial and fungal strains and therefore have potential applications in biotechnology and biomedical science.
The population structure of Mycobacterium tuberculosis is typically clonal therefore genotypic lineages can be unequivocally identified by characteristic markers such as mutations or genomic deletions. In addition, drug resistance is mainly mediated by mutations. These issues make multiplexed detection of selected mutations potentially a very powerful tool to characterise Mycobacterium tuberculosis. We used Multiplex Ligation-dependent Probe Amplification (MLPA) to screen for dispersed mutations, which can be successfully applied to Mycobacterium tuberculosis as was previously shown. Here we selected 47 discriminative and informative markers and designed MLPA probes accordingly to allow analysis with a liquid bead array and robust reader (Luminex MAGPIX technology). To validate the bead-based MLPA, we screened a panel of 88 selected strains, previously characterised by other methods with the developed multiplex assay using automated positive and negative calling. In total 3059 characteristics were screened and 3034 (99.2%) were consistent with previous molecular characterizations, of which 2056 (67.2%) were directly supported by other molecular methods, and 978 (32.0%) were consistent with but not directly supported by previous molecular characterizations. Results directly conflicting or inconsistent with previous methods, were obtained for 25 (0.8%) of the characteristics tested. Here we report the validation of the bead-based MLPA and demonstrate its potential to simultaneously identify a range of drug resistance markers, discriminate the species within the Mycobacterium tuberculosis complex, determine the genetic lineage and detect and identify the clinically most relevant non-tuberculous mycobacterial species. The detection of multiple genetic markers in clinically derived Mycobacterium tuberculosis strains with a multiplex assay could reduce the number of TB-dedicated screening methods needed for full characterization. Additionally, as a proportion of the markers screened are specific to certain Mycobacterium tuberculosis lineages each profile can be checked for internal consistency. Strain characterization can allow selection of appropriate treatment and thereby improve treatment outcome and patient management.
We report on the identification of two new Francisella-like endosymbionts (FLEs) found in three different tick species from Bulgaria. The FLEs were characterized by 16S rRNA and tul4 gene sequencing and seem to lack the molecular marker RD1. These two new taxa seem to be facultative secondary endosymbionts of ticks.
Brucellosis is the most common anthropozoonosis, with more than 500,000 cases annually. While the disease was eradicated in the vast majority of industrialized regions around the world, it remains a significant public health concern, mainly in the Mediterranean littoral, the Middle East, the Arabian Peninsula, the Indian subcontinent, Asia, Africa, and Central and South America (19,26).Turkey is a relatively large country in the eastern Mediterranean region, with a geographical surface of 783,562 km 2 , and comprises seven regions. It has a population of 72 million, 70% of which lives in cities and 30% in rural areas. Brucellosis is endemic, and approximately 10,000 human brucellosis cases are reported annually. The reported incidence is 150 cases per 1 million inhabitants (24). Its prevalence varies widely from region to region due to several factors, including food habits, milk processing methods, husbandry practices, nomadism, social customs, climatic conditions, socioeconomic status, and environmental conditions. A steady increase of reported human cases was observed from 1986 (3.03/100,000 population) until 2004 (25.65/100,000). Livestock vaccination, elimination of infected animals, control of animal movements, and education induced a decline in the number of annually reported human cases, from 18,563 cases in 2004 to 9,818 cases in 2008 (17).Rapid and accurate typing procedures are crucial for epidemiologic surveillance, investigation of outbreaks, and follow-up of a control program. Many molecular typing methods commonly used for the subtyping of isolates of other bacterial species are not appropriate for routine typing of Brucella strains, and none has proven to be fully satisfactory for epidemiological trace-back investigations of brucellosis (1,9,25). Recently, a selection of 16 variable-number tandem repeats has been proposed for fingerprinting Brucella isolates (7,14,25). This multiple-locus variable-number tandem-repeat analysis (MLVA) genotyping system, MLVA-16 Orsay , comprised eight minisatellite markers (panel 1, Bruce06, Bruce08, Bruce11, Bruce12, Bruce42, Bruce43, Bruce45, and Bruce55) for species identification and eight complementary microsatellite markers (panel 2A, Bruce18, Bruce19, and Bruce21; panel
Bulgarian Ixodes ricinus ticks were examined for Ehrlichia and Borrelia coinfection: 34 and 32% of adult ticks and at least 2 and 10% of nymphs were positive for these infections, respectively. Coinfections and dual or triple Borrelia infections were frequent, although Ehrlichia phagocytophila heterogeneity was minimal. Multiple tick-borne bacteria coexist in I. ricinus ticks in southeastern Europe
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.