Comparative proteomic profiles of Aspergillus fumigatus and Aspergillus lentulus strains by surface-enhanced laser desorption ionization time-of-flight mass spectrometry (SELDI-TOF-MS)

<p>Abstract</p> <p>Background</p> <p>Surface-enhanced laser desorption ionization time-of-flight mass spectrometry (SELDI-TOF-MS) was applied to analyze the protein profiles in both somatic and metabolic extracts of <it>Aspergillus </it>species. The study was carried out on some <it>Aspergillus </it>species within the <it>Fumigati </it>section (<it>Aspergillus fumigatus </it>wild-types and natural abnormally pigmented mutants, and <it>Aspergillus lentulus</it>). The aim was to validate whether mass spectrometry protein profiles can be used as specific signatures to discriminate different <it>Aspergillus </it>species or even mutants within the same species.</p> <p>Results</p> <p>The growth conditions and the SELDI-TOF parameters were determined to generate characteristic protein profiles of somatic and metabolic extracts of <it>Aspergillus fumigatus </it>strains using five different ProteinChips^®, eight growth conditions combining two temperatures, two media and two oxygenation conditions. Nine strains were investigated: three wild-types and four natural abnormally pigmented mutant strains of <it>A. fumigatus </it>and two strains of <it>A. lentulus</it>. A total of 242 fungal extracts were prepared. The spectra obtained are protein signatures linked to the physiological states of fungal strains depending on culture conditions. The best resolutions were obtained using the chromatographic surfaces CM10, NP20 and H50 with fractions of fungi grown on modified Sabouraud medium at 37°C in static condition. Under these conditions, the SELDI-TOF analysis allowed <it>A. fumigatus </it>and <it>A. lentulus </it>strains to be grouped into distinct clusters.</p> <p>Conclusions</p> <p>SELDI-TOF analysis distinguishes <it>A. fumigatus </it>from <it>A. lentulus </it>strains and moreover, permits separate clusters of natural abnormally pigmented <it>A. fumigatus </it>strains to be obtained. In addition, this methodology allowed us to point out fungal components specifically produced by a wild-type strain or natural mutants. It offers attractive potential for further studies of the <it>Aspergillus </it>biology or pathogenesis.</p

Drug inhibition of HDAC3 and epigenetic control of differentiation in Apicomplexa parasites

Plasmodium and Toxoplasma are parasites of major medical importance that belong to the Apicomplexa phylum of protozoa. These parasites transform into various stages during their life cycle and express a specific set of proteins at each stage. Although little is yet known of how gene expression is controlled in Apicomplexa, histone modifications, particularly acetylation, are emerging as key regulators of parasite differentiation and stage conversion. We investigated the anti-Apicomplexa effect of FR235222, a histone deacetylase inhibitor (HDACi). We show that FR235222 is active against a variety of Apicomplexa genera, including Plasmodium and Toxoplasma, and is more potent than other HDACi's such as trichostatin A and the clinically relevant compound pyrimethamine. We identify T. gondii HDAC3 (TgHDAC3) as the target of FR235222 in Toxoplasma tachyzoites and demonstrate the crucial role of the conserved and Apicomplexa HDAC-specific residue TgHDAC3 T99 in the inhibitory activity of the drug. We also show that FR235222 induces differentiation of the tachyzoite (replicative) into the bradyzoite (nonreplicative) stage. Additionally, via its anti-TgHDAC3 activity, FR235222 influences the expression of ∼370 genes, a third of which are stage-specifically expressed. These results identify FR235222 as a potent HDACi of Apicomplexa, and establish HDAC3 as a central regulator of gene expression and stage conversion in Toxoplasma and, likely, other Apicomplexa

Serological diagnosis of toxoplasmosis: evaluation of the commercial test recomLine Toxoplasma IgG immunoblot (Mikrogen) based on recombinant antigens

Background: IgG detection to determine immune status to Toxoplasma gondii infection and seroconversion mainly relies on ELISA techniques and, if necessary, on a confirmatory test, Western blot. This study evaluated the performance of the recomLine Toxoplasma IgG immunoblot (IB-recomLine) (Mikrogen) as a confirmatory test on a large number of sera. A total of 171 sera were selected (113 patients) and had previously been analyzed by two ELISA tests, ARCHITECT (Abbott) and VIDAS (bioMérieux) ± LDBIO-Toxo II IgG Western blot (WB-LDBIO) (LDBio). The sera were classified into three groups: group 1 included 50 sera without difficulty in interpreting the IgG results (patients with documented past infection or uninfected); group 2 included 47 sera with difficulty in interpreting the ELISA results; and group 3 included 74 sequential sera from 25 pregnant women with seroconversion. Results: In group 1, overall IgG agreements were 94% and 90% with ARCHITECT and VIDAS, respectively. In group 2, low agreement was observed between IB-recomLine and WB-LDBIO, with eight false-positive and 13 false-negative results. In group 3, 4/13 seroconversions were detected earlier with IB-recomLine compared to other tests. Conclusions: IB-recomLine allowed for earlier diagnosis of toxoplasmic seroconversion compared to both ELISA tests and WB-LDBIO but led to insufficient performance to confirm the immune status when ELISA results were discordant or equivocal

Toxoplasmosis in transplant recipients, Europe, 2010-2014

Transplantation activity is increasing, leading to a growing number of patients at risk for toxoplasmosis. We reviewed toxoplasmosis prevention practices, prevalence, and outcomes for hematopoietic stem cell transplant (HSCT) and solid organ transplant (SOT; heart, kidney, or liver) patients in Europe. We collected electronic data on the transplant population and prevention guidelines/regulations and clinical data on toxoplasmosis cases diagnosed during 2010-2014. Serologic pretransplant screening of allo-hematopoietic stem cell donors was performed in 80% of countries, screening of organ donors in 100%. SOT recipients were systematically screened in 6 countries. Targeted anti-Toxoplasma chemoprophylaxis was heterogeneous. A total of 87 toxoplasmosis cases were recorded (58 allo-HSCTs, 29 SOTs). The 6-month survival rate was lower among Toxoplasma-seropositive recipients and among allo-hematopoietic stem cell and liver recipients. Chemoprophylaxis improved outcomes for SOT recipients. Toxoplasmosis remains associated with high mortality rates among transplant recipients. Guidelines are urgently needed to standardize prophylactic regimens and optimize patient management

Detection of Toxoplasma gondii DNA and specific antibodies in high-risk pregnant women.

Primary maternal infection with toxoplasmosis during pregnancy is frequently associated with transplacental transmission to the fetus. This study was conducted to test the utility of a polymerase chain reaction (PCR) assay to detect recent infections with Toxoplasma in pregnant women. One hundred forty-eight women with high-risk pregnancies who had abnormal pregnancy outcomes (cases) and 100 with normal pregnancies (controls) were tested for the presence of Toxoplasma DNA in their blood by a nested PCR and specific antibodies to Toxoplasma by an enzyme-linked immunosorbent assay. The IgG results of the cases differed significantly from those of the controls (54% and 12%, respectively; P < 0.02). Four (2.7%) of the cases were IgM positive, but none of the controls were positive. Detection of Toxoplasma DNA in 20 (8.1%) of the IgG-positive cases suggests a recent infection. The risk factors associated with the infection were eating raw meat and contact with soil. The diagnostic serology of recent infection in early pregnancy could be confirmed by a positive Toxoplasma-specific PCR result in blood samples collected in the first half of pregnancy, even in the presence of serologic results difficult to interpret due to the lack of sequential follow-up during pregnancy

[Trypanosomiases]

Trypanosomiases are imported and rare parasitosis on the French metropolitan territory. They are re-emerging in some endemic areas, and their mode of transmission can lead to an increase of imported cases in a near future. They can be responsible for serious disease. In this paper, we describe the basic data concerning epidemiology, clinical features, diagnosis, treatment and prevention of sleeping sickness (Africa) and Chagas disease (Latin America)

Editorial: Parasites in the Tropic—A New Paradigm Shift

The highlight of this eBook is to bring new insights into parasites in the tropic. To achieve that, much has been discussed about risk assessment, infection rates, disease burden, hormones and mechanism of immune response, genetic expression and susceptibility as well as, therapeutic modalities. Authors raised hypothesis, discuss concepts, and show open questions. The remaining important issues to resolve questions within parasites in the tropic – a new paradigm shift are briefly discussed below. T. gondii, feline as the definitive host, is regarded as one of the most important parasites in the tropic. Human, as an accidental host, is the only species who still drinks raw milk or milk products particularly from animal sources. Based on the first paper, the author simplifies on how safe to drink milk to prevent the transmission of T. gondii by the insistence on heat treated milk before consumption. It is interesting to explore how hormone plays its role in Toxoplasma infection. Based on the second paper, the authors elucidated from thirty studies from humans, animals and cell cultures. Of these, it was shown that Toxoplasma infection was controlled by the presence of hormones found in different animal models. However, it is still premature to conclude which hormone that has a significant relationship with Toxoplasma infection. It estimates that one-third of the world population infected with T. gondii but the majority are asymptomatic. Based on the third paper, it demonstrated that people having low prevalent of Toxoplasma infection by having close contact with animals. This study will enhance positive attitudes for more people to be committed towards helping animals. For more than three decades, T. gondii has since been identified as one of the most important opportunistic parasitic pathogens in immunocompromised. Seroprevalence of chronic toxoplasmosis was detected in at least one-third of HIV-infected individuals in the regional hospital of southern Thailand, as reported from the fourth paper. Thailand has successfully formulated anti-retroviral therapy for HIV/AIDS patients and as a result reported a rare incidence of AIDS-related cerebral toxoplasmosis (CT) in this setting. Based on the fifth paper, the authors demonstrated low IL-10 (Th2 response) and IFN-γ (Th1 response) as well as high TNF-α were produced in ocular and cerebral toxoplasmosis in AIDS patients. This might be due to South American strains and/or the genetic susceptibility of the host.Due to high genetic diversity of T. gondii in Brazil, the sixth paper demonstrated that Calomys callosus survived chronically infected by T. gondii clonal type II strain and reinfected by Brazilian strains. However, congenital toxoplasmosis occurred leading to damaging effects of the developing fetus. The seventh paper conducted a questionnaire-based study on knowledge and practice on Toxoplasma infection among pregnant women from Malaysia, Philippines and Thailand. It clearly demonstrated that health education, a core value, is the cheapest and the best option to envisage the preventive strategies of feto-maternal toxoplasmosis from this region. For treatment modality of congenital toxoplasmosis, a novel experimental therapeutic synergism of diclazuril plus atovaquone combination shows a promising outcome with no toxicity in treating this condition, as demonstrated in the eighth paper. However, it warrants for future trials to prove its properties against T. gondii in different clinical scenarios of human toxoplasmosis for more effective therapeutic regimens. In the ninth paper, the author discussed the pathogenesis of maternal and congenital toxoplasmosis, the current treatment in clinical practice, and the experimental treatment approaches for promising future trials. Overall, this protozoan represents the most extraordinary example of parasite in the tropic and beyond scientific imagination. Hence, there are still many challenges ahead and waiting for more explorations on T. gondii, the parasite that never dies. Based on the findings from the tenth paper, it is interesting to identify common gene targets between Glossina p. gambiensis and Glossina m. morsitans that might shed some lights as a suitable candidate for controlling both acute and chronic forms of sleeping sickness. This therefore requires further investigations using proteomic analysis to ascertain the corresponding genes and its proteins as well as functional role that may help the search for more novel therapeutic agents