Drug Resistance in Toxoplasma gondii Montazeri, Mahbobeh; Mehrzadi, Saeed; Sharif, Mehdi ...
Frontiers in microbiology,
10/2018, Letnik:
9
Journal Article
Recenzirano
Odprti dostop
(
) is a global protozoan parasite infecting up to one-third of the world population. Pyrimethamine (PYR) and sulfadiazine (SDZ) are the most widely used drugs for treatment of toxoplasmosis; ...however, several failure cases have been recorded as well; suggesting the existence of drug resistant strains. This review aims to give a systematic and comprehensive understanding of drug resistance in
including mechanisms of resistance and sites of drug action in parasite. Analogous amino acid substitutions in the
enzyme were identified to confer PYR resistance. Moreover, resistance to clindamycin, spiramycin, and azithromycin is encoded in the rRNA genes of
. However,
SDZ resistance mechanism has not been proved yet. Recently there has been a slight increase in SDZ resistance. That is why the majority of studies were carried out using SDZ. Six strains resistant to SDZ were found in clinical cases between 2013 and 2017 which among Brazilian
isolates, TgCTBr11, Ck3, and Pg1 were identified in human toxoplasmosis, as well as in livestock intended for human consumption. In conclusion, recent experimental studies in clinical cases have clearly shown that drug resistance in
is ongoing. Thus, establishing a more effective therapeutic scheme in the treatment of toxoplasmosis is critically needed. The emergence of
strains resistant to current drugs, reviewed here, represents a concern not only for treatment failure but also for increased clinical severity in immunocompromised patients. To improve the therapeutic outcome in patients, a greater understanding of the exact mechanisms of drug resistance in
should be developed. Thus, monitoring the presence of resistant parasites, in food products, would seem a prudent public health program.
This paper presents the properties of epoxy nanocomposites, prepared using a synthesized hybrid Polypyrrole-Graphene Oxide (PPy-GO) filler, via in-situ chemical polymerization, at various filler ...loadings (i.e., 0.5–2 w. t %). The microstructures and properties of the PPy-GO hybrids and epoxy nanocomposites were studied via Fourier transform infrared (FTIR), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), mechanical (Tensile Properties), electrical, Dynamic mechanical thermal analysis (DMTA) and thermogravimetric analyses (TGA). Morphological study demonstrated that varying the nanofiller nature (PPy-GOs, PPy or GO) lead to different states of dispersion. Mechanical, electrical and thermal analysis demonstrated that the hybrid concentration and its architecture (PPy:GO ratio) are interesting factors significantly affected the properties of the epoxy based nanocomposites. On the other hand, the mechanical performance of the cured nanocomposites outperformed the PPy-GO, with enhancements of 78% and 51% of Young's modulus and strength, respectively. Here it has been established that the embedding of PPy-GO hybrids into pristine epoxy endows optimum dispersion of PPy and GO as well as better interfacial adhesion between the fillers and matrix, which results in a significant improvement in load transfer effectiveness. Electrical conductivity measurements showed that conductivity of epoxy filled nanocomposites increased up 10−4 S/cm for Epoxy/PPy-GO nanocomposites. DMTA test indicated that incorporation of PPy-GO resulted in a significantly increase in Tg of the resultant nanocomposites, which is attributed to the highly exfoliation structure and the stronger interfacial interaction. The PPy-GO particles enhanced electrical, thermal and mechanical properties of nanocomposites, confirming the synergistic effect of PPy-GO as multifunctional filler.
Felids (domestic and wild cats) are important in the epidemiology of the parasite Toxoplasma gondii because they are the only hosts that can excrete the environmentally resistant oocysts. We ...conducted a systematic review and meta-analysis to estimate the global prevalence of T. gondii in species of the family Felidae.
We searched seven databases (PubMed, Embase, Google Scholar, ScienceDirect, Scopus, Proquest and Web of Science) for studies reporting seroprevalence of T. gondii in felids from 1967 to 31 December 2017. A total of 217 published papers, containing 223 datasets were eligible for inclusion in the meta-analysis, comprised 59,517 domestic and 2733 wild cats from 1967 to 2017.
The pooled global T. gondii seroprevalence was estimated to be 35% (95% CI: 32-38%) and 59% (95% CI: 56-63%) in domestic cats and wild felids, respectively, using random effects model. The seroprevalence was higher in Australia and Africa where the T. gondii seropositivity in domestic cats was 52% (95% CI: 15-89%) and 51% (95% CI: 20-81%), respectively. The lowest seroprevalence was estimated in Asia 27% (95% CI: 24-30%). The seroprevalence values for T. gondii in wild felids were 74% (95% CI: 62-83%) in Africa, 67% (95% CI: 23-111%) in Asia, 67% (95% CI: 58-75%) in Europe and 66% (95% CI: 41-91%) in South America.
Our study provides the global prevalence of T. gondii in species of the family Felidae and is a source of information to aid public health workers in developing prevention plans.
In this study, we have investigated the methods for development of a double layer ZnO-based coating through incorporation of a thin layer of low surface energy coating without any additional ...treatments. A binary micro-nano structure was observed on the surface topography analysis from the field emission scanning electron microscopy (FESEM) contact angle measurements on the surface, for oil droplet was 85° which is indicative of stable oleophobic properties which might contribute to the low surface energy on the coating and also relate to the surface roughness according to the randomly distributed ZnO particles. We believe that such multifunctional coatings can potentially impose many promising properties for engineering superolephobic surfaces.
In this paper, reduced graphene oxide decorated with silver nanoparticle (rGO-Ag) nanohybrids were prepared using an environmentally friendly approach and incorporated as reinforcement in ...poly(vinylidene fluoride)-poly(methyl methacrylate) blends via a melt mixing process. The microstructure of rGO-Ag nanohybrids and its effect on the microstructure, mechanical, thermal, and electrical properties of the PVDF/PMM/rGO-Ag was studied using Fourier transform infrared (FTIR), Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), tensile, thermogravimetric analysis (TGA), and impedance spectroscopy methods. FTIR and TEM analysis confirmed that rGO-Ag successfully synthesized and Ag nanoparticles are located on the rGO surface. The tensile analysis demonstrated that incorporating 1 wt.% of rGO-Ag in PVDF/PMMA blend increases Young’s modulus and strength of nanocomposite up to 31% and 35%, respectively. The Halpin-Tsai model was also used for PVDF/PMMA/rGO-Ag nanocomposites, and the results confirmed that this model works well to predict the tensile modulus. Impedance spectroscopy analysis showed that the presence of rGO-Ag nanohybrids in PVDF/PMMA blend effectively enhanced the conductivity of PVDF/PMMA blend. TGA results demonstrated that the presence of rGO-Ag nanohybrids enhanced the thermal stability of nanocomposites and increased the degradation temperature of PVDF/PMMA/rGO-Ag nanocomposites in the range of 20°C compared to PVDF/PMMA blend.
Toxoplasma gondii (T. gondii) is an obligate intracellular opportunistic parasite that is the causative agent of toxoplasmosis. This parasite accounts for mental disorders; however, the relationship ...between T. gondii infection and depressive disorder is unclear. Regarding this, the present systematic review and meta-analysis was conducted to investigate the scientific evidence regarding the potential association between major depression disorder (MDD) and Toxoplasma infection.
For the purpose of the study, the articles related to the subject of interest were systematically searched in seven electronic databases. Special attention was given to the studies examining T. gondii seropositivity level in depressed patients and controls.
The search process resulted in the identification of a total of 30 publications meeting the inclusion criteria and published up to April 2018 for the systematic review. Furthermore, 29 studies met the inclusion criteria to be entered into meta-analysis. Our meta-analysis involved the review of cross-sectional studies including 1657 depressed patients and 19565 individuals as controls and case-control studies entailing 1311 depressed cases and 6015 controls without depression. 1582 depressed people participated in cross-sectional studies whose results were reported as odds ratio (OR). In addition, the total number of participants was 15068 in this type of studies. Statistical analysis indicated that the pooled OR of the risk of anti-T. gondii IgG antibody in depressed individuals in case-control and cross-sectional studies was 1.15 (95% confidence interval (CI): 0.95-1.39).
As the findings of the reviewed articles indicated, toxoplasmosis is not a risk factor for MDD. However, it is necessary to perform further research to clarify the detailed association between T. gondii and dysthymia or mild and moderate depression. Furthermore, it is recommended to better investigate the effect of antibody titers on the relationship between depression and T. gondii infection.
Novel technologies such as partial nitritation (PN) and partial denitritation (PDN) could be combined with the anammox-based process in order to alleviate energy input. The former combination, also ...noted as deammonification, has been intensively studied in a frame of lab and full-scale wastewater treatment in order to optimize operational costs and process efficiency. For the deammonification process, key functional microbes include ammonia-oxidizing bacteria (AOB) and anaerobic ammonia oxidation bacteria (AnAOB), which coexisting and interact with heterotrophs and nitrite oxidizing bacteria (NOB). The aim of the presented review was to summarize current knowledge about deammonification process principles, related to microbial interactions responsible for the process maintenance under varying operational conditions. Particular attention was paid to the factors influencing the targeted selection of AOB/AnAOB over the NOB and application of the mathematical modeling as a powerful tool enabling accelerated process optimization and characterization. Another reviewed aspect was the potential energetic and resources savings connected with deammonification application in relation to the technologies based on the conventional nitrification/denitrification processes.
Toxoplasma gondii (T. gondii) is one of the most pervasive neurotropic pathogens causing different lesions in a wide variety of mammals as intermediate hosts, including humans. It is estimated that ...one-third of the world population is infected with T. gondii; however, for a long time, there has been much interest in the examination of the possible role of this parasite in the development of mental disorders, such as Alzheimer's disease (AD). T. gondii may play a role in the progression of AD using mechanisms, such as the induction of the host's immune responses, inflammation of the central nervous system (CNS), alteration in the levels of neurotransmitters, and activation of indoleamine-2,3-dyoxigenase. This paper presents an appraisal of the literature, reports, and studies that seek to the possible role of T. gondii in the development of AD. For achieving the purpose of the current study, a search of six English databases (PubMed, ScienceDirect, Web of Science, Scopus, ProQuest, and Google Scholar) was performed. The results support the involvement of T. gondii in the induction and development of AD. Indeed, T. gondii can be considered a risk factor for the development of AD and requires the special attention of specialists and patients. Furthermore, the results of this study may contribute to prevent or delay the progress of AD worldwide. Therefore, it is required to carry out further studies in order to better perceive the parasitic mechanisms in the progression of AD.
Alzheimer, toxoplasmosis, risk factors, neurotransmitter, cytokine
In this paper, we fabricate Epoxy/ZnO-GO composite films using photoinduced cationic ring opening polymerization processes with self-cleaning ability and improved thermal properties under the photo ...exposure. The presence of ZnO nanoparticles on the GO surface aids in achieving good self-cleaning properties by removing model dirt, methylene blue, (within 1-2 h) under sunlight. An increase of almost 15 ℃ in the thermal stability was obtained by introduction of 0.6 wt% ZnO-GO to the epoxy matrix. Therefore, the nanocomposite could be a promising futuristic material for many advanced applications and used as a surface coating material where it can remove the presence of organic dirt and provide a clean surface.
We developed a new and effective strategy for compatibilizing immiscible polymer blend nanocomposites of polyethylene/high-impact polystyrene/graphite oxide (PE/HIPS/GO) by a combination of solution ...intercalation and a melt-mixing method. GO was first dispersed in HIPS by a solution-mixing method and then added to melted PE. The effect of variations in the mixing conditions, such as the rotor speed and loading level of the filler, on the morphology and mechanical (tensile) and thermal properties of the nanocomposite blends was investigated using XRD, SEM, TEM and TGA. The morphological study showed that varying the mixing conditions resulted in different states of dispersion and different localizations of the filler. As a result, the ductility of the polymer blends filled with GO was notably increased. The compatibilizing effect of GO results from the fact that GO can minimize the interfacial tension between PE and HIPS if it is localized at the interface. Unlike traditional copolymer compatibilizers, GO can also act as a reinforcing filler in polymer blends, thus remarkably enhancing their mechanical strength and thermal stability.
We develop here a new and effective strategy for compatibilizing immiscible polymer blend nanocomposites of polyethylene/high impact polystyrene/graphite oxide (PE/HIPS/GO) by combination of solution intercalation and melt mixing method.
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