Colimitation assessment of phytoplankton growth using a resource use efficiency approach in the Bay of Seine (French-English Channel).

Eutrophication and dystrophy are two of the main problems affecting coastal ecosystems. In the Bay of Seine, phosphorus (P) inputs from the Seine estuary have been largely reduced in the last decade, in contrast to nitrogen (N), which leads to high N/P ratio inputs. To study the effect of dystrophy, an enrichment bioassay using water sampled from the Bay of Seine was repeated 19 times over a period of 18 months with six different enrichments.

Coupling high frequency monitoring and bioassay experiments to investigate a harmful algal bloom in the Bay of Seine (French-English Channel).

Coastal ecosystems are increasingly threatened by eutrophication and dystrophy. In this context, the full pattern of a bloom dominated by the dinoflagellate, Lepidodinium chlorophorum, was investigated by a high frequency monitoring buoy equipped with sensors allowing nutrients and photosynthesis measurements. An increase of the N/P ratio affected phytoplankton physiology leading to bloom collapse with a slight oxygen depletion.

Toxoplasmosis among pregnant women: high seroprevalence and risk factors in Kinshasa, Democratic Republic of Congo.

Objective: To determine the seroprevalence of toxoplasmosis in pregnant women, as well as the proportion of acutely infected and risk factors in the Democratic Republic of Congo.

Methods: Thirty maternities in Kinshasa were randomly selected and women attending antenatal consultation were invited to participate. They were interviewed with a structured questionnaire about known risk factors (age, meat consumption, contact with soil, and presence of cat) and a venous blood sample was taken.

Analytical validation of anti-toxoplasma IgG immunoassays.

There are often discrepancies when using different methods to measure anti-Toxoplasma gondii IgG levels in patient samples. The diagnostic performance of a chemiluminescent immunoassay (CLIA) and an enzyme-linked fluorescent assay (ELFA) used as confirmatory tests for samples identified as positive or equivocal by an electrochemiluminescent immunoassay (ECLIA) were examined. Cut-off values were those stated by the manufacturer, and Western blot was used to confirm the results of all methods.

Evaluation of the new Elecsys Toxo IgG avidity assay for toxoplasmosis and new insights into the interpretation of avidity results.

Detection and treatment of acute toxoplasmosis during pregnancy can avoid severe disease of the fetus. In this context, assessment of anti-Toxoplasma IgG avidity has been shown to exclude recent infection. The Elecsys Toxo IgG and IgM assays (Roche Diagnostics) have been validated for screening pregnant women and a new assay, Elecsys Toxo IgG Avidity, was recently developed.

Comparison of mother and child antibodies that target high-molecular-mass Toxoplasma gondii antigens by immunoblotting improves neonatal diagnosis of congenital toxoplasmosis.

This retrospective study proposes a new reading of immunoblotting (IB) in the diagnosis of congenital toxoplasmosis. Our findings demonstrate that a three-IgM-band association at 75, 90, and 100 kDa called the IgM triplet increases the sensitivity to 95.8% when combined with prenatal and serological neonatal tests.

Evaluation of the usefulness of six commercial agglutination assays for serologic diagnosis of toxoplasmosis.

Six agglutination tests for detecting Toxoplasma gondii-specific antibodies (immunoglobulin G or M) in serum were performed and compared. In total, 599 sera were examined using direct and indirect agglutination assays. Sensitivity varied from 93.

[Congenital toxoplasmosis: randomised comparison of strategies for retinochoroiditis prevention].

In France, children with confirmed congenital toxoplasmosis receive a treatment for a period of 12 to 24 months. Such prolonged treatment may generate potentially severe risks, in particular hematologic and cutaneous. Our objective is to compare the effectiveness of two therapeutic strategies on the prevention of retinochoroiditis by a randomized, non-inferiority, open-label, parallel study including 486 children, 3 to 6 months of age with a non-severe form of congenital toxoplasmosis.

Accuracy of real-time polymerase chain reaction for Toxoplasma gondii in amniotic fluid.

Objective: To provide clinicians with information about the accuracy of real-time polymerase chain reaction (PCR) analysis of amniotic fluid for the prenatal diagnosis of congenital Toxoplasma infection.

Methods: This was a prospective cohort study of women with Toxoplasma infection identified by prenatal screening in three centers routinely carrying out real-time PCR for the detection of Toxoplasma gondii in amniotic fluid. The data available were gestational age at maternal infection, types and dates of maternal treatment, results of amniocentesis and neonatal work-up and definitive infectious status of the child.

[Management of congenital toxoplasmosis in France: current data].

Congenital toxoplasmosis is caused by transplacental contamination of the fetus withToxoplasma gondiifollowing maternal primary infection. The risk of mother-to-child transmission depends on the term of pregnancy at the time of maternal infection. The risk is lower than 5% in the first trimester but can reach 90% in the last days of pregnancy.

Genotype of 88 Toxoplasma gondii isolates associated with toxoplasmosis in immunocompromised patients and correlation with clinical findings.

We report the genotyping analysis of Toxoplasma gondii isolates in samples collected from 88 immunocompromised patients, along with clinical and epidemiological data. Most of these samples were collected in France during the current decade by the Toxoplasma Biological Resource Center. Lack of specific anti-Toxoplasma treatment, pulmonary toxoplasmosis, and involvement of multiple organs were the 3 main risk factors associated with death for this patient group.

Genetic and epigenetic factors at COL2A1 and ABCA4 influence clinical outcome in congenital toxoplasmosis.

Background: Primary Toxoplasma gondii infection during pregnancy can be transmitted to the fetus. At birth, infected infants may have intracranial calcification, hydrocephalus, and retinochoroiditis, and new ocular lesions can occur at any age after birth. Not all children who acquire infection in utero develop these clinical signs of disease.

LDBio-Toxo II immunoglobulin G Western blot confirmatory test for anti-toxoplasma antibody detection.

Tests commonly used for routine determination of anti-Toxoplasma gondii immunoglobulin G (IgG) antibodies show a high level of consistency. However, considerable variations between commercial screening tests are still observed in detecting antibodies present at low concentrations, leading to a number of discrepant and/or equivocal results. It is therefore important to use a reference test to confirm borderline results.

Risk factors for retinochoroiditis during the first 2 years of life in infants with treated congenital toxoplasmosis.

Background: Retinochoroiditis is the main complication of congenital toxoplasmosis. Its risk factors have rarely been investigated and were the object of this study.

Methods: A retrospective study was conducted on 300 infants with congenital toxoplasmosis born between July 1, 1996 and December 31, 2002 and treated with pyrimethamine and sulfonamide for at least 12 months.

Severe Toxoplasma gondii I/III recombinant-genotype encephalitis in a human immunodeficiency virus patient.

The reactivation of an uncommon type I/III recombinant-genotype Toxoplasma gondii strain resulted in unusually severe encephalitis and chorioretinitis associated with a cerebral salt wasting syndrome in an African human immunodeficiency virus patient. This observation suggests an influence of the parasite genotype on disease expression in immunocompromised patients.

Outcome for children infected with congenital toxoplasmosis in the first trimester and with normal ultrasound findings: a study of 36 cases.

Objective: We wished to investigate the prognosis of children infected with Toxoplasma gondii during the first trimester of pregnancy and whose ultrasound findings were entirely normal, in order to find out whether congenital toxoplasmosis did or did not justify termination of pregnancy if there was no fetal abnormality on ultrasound.

Study Design: A prospective and retrospective study was carried out by 12 French centers who enrolled 36 children infected with T. gondii during the first trimester of pregnancy and whose ultrasound examinations showed no anomaly.

Timely diagnosis of disseminated toxoplasmosis by sputum examination.

The diagnosis of disseminated toxoplasmosis in a 14-year-old allogeneic bone marrow recipient with graft-versus-host disease was determined by the detection of Toxoplasma gondii tachyzoites in sputum smears. Sputum analysis is a valuable alternative in the clinical assessment of pulmonary toxoplasmosis, especially when conventional invasive techniques are not practicable.

Usefulness of quantitative polymerase chain reaction in amniotic fluid as early prognostic marker of fetal infection with Toxoplasma gondii.

Objective: Our purpose was to evaluate Toxoplasma gondii concentration in amniotic fluid (AF) samples as a prognostic marker of congenital toxoplasmosis.

Study Design: A retrospective study was carried out in 88 consecutive AF samples from 86 pregnant women, which were found positive by prospective polymerase chain reaction (PCR) testing. Parasite AF concentrations were estimated by real-time quantitative PCR and analyzed in relation to the clinical outcome of infected fetuses during pregnancy and at birth, taking into account the gestational age at maternal infection.