[Double fungemia. Report of four Tunisian cases]. / Les fongémies mixtes. À propos de quatre cas tunisiens.

UNLABELLED: Fungemia is classically caused by a single species and the detection of more than one species in blood samples is uncommon. We report four cases of mixed fungemia (MF) diagnosed in the parasitology-mycology laboratory of Farhat-Hached hospital in Sousse, Tunisia. The MF episodes occurred in two neonates and two adults suffering from acute myeloid leukemia. Two fungal species were detected concomitantly within the same blood culture in all cases. Species combination was detected by the subculture of the blood culture on Candida ID(®) chromogenic medium in three cases and on Sabouraud agar in one case. Predisposing factors were: indwelling catheters (4/4), broad-spectrum antibiotics (3/4), neutropenia (2/4), exclusive parenteral nutrition (2/4) and Candida colonization (1/4). Patients presented febrile sepsis with no response to broad-spectrum antibiotic therapy in all cases. Outcome under antifungal treatment was favorable in two cases and the two other patients died. CONCLUSION: MF appears similar to the more common monomicrobial fungemia. The use of chromogenic media in routine can improve the detection of MF episodes allowing appropriate antifungal therapy.

[Evaluation of the immunoblotting for the detection of immunoglobulin G Toxoplasma antibodies in immunocompetent patients]. / Apport de l'immunoblot dans la détection des IgG anti-toxoplasmiques chez le sujet immunocompétent.

UNLABELLED: The serological tests commonly used for the diagnosis of toxoplasmosis raise the problem of the interpretation of the borderline immunoglobulin G (IgG) levels and discordant results between various tests. OBJECTIVE: The purpose of our study was to evaluate the contribution of the immunoblotting in the detection of specific IgG in acquired toxoplasmosis of immunocompetent patients especially when levels are equivocal or discordant in enzyme-linked immunosorbent assay (Elisa) and indirect fluorescent antigen test (IFAT). MATERIAL AND METHODS: [corrected] We tested three groups of sera. The first included 87 positive sera, the second 33 negative sera, and the last one 29 equivocal sera. RESULTS: Results obtained with the first and the second group of sera led us to identify the bands 30kDa and 32kDa as markers of the toxoplasmic infection. The simultaneous presence of both bands showed a sensitivity of 91.5%, a specificity of 96.9%, a VPP of 98.7%, a VPN of 74.4% and a Youden's index of 0.88. Our findings suggest that the presence of these two bands is a reliable criterion for the confirmation of the presence of anti-toxoplasmic IgG in the corresponding serum. The immunoblot allowed us to ascertain serological status of 27 (93.1%) patients from the third group in which results were discrepant or equivocal in Elisa and/or in IFAT. CONCLUSION: Immunoblot is a useful serological test for detection of very low or equivocal titers.

Twenty-nine cases of invasive aspergillosis in neutropenic patients.

INTRODUCTION: Invasive aspergillosis is a life-threatening infectious complication in hematological patients undergoing immunosuppressive chemotherapy. PATIENTS AND METHODS: We report 29 cases of invasive aspergillosis diagnosed in the Sousse Farhat Hached hospital Hematology unit, Tunisia, between 2002 and 2010. RESULTS: The most frequent disease (65.5%) was acute myeloid leukemia. All patients were severely neutropenic (<500/mm(3), mean duration=27 days). Pulmonary invasive aspergillosis was suggested in 28 (96.5%) cases. The most frequent respiratory signs were cough (64.3%), chest pain (53.6%), and hemoptysis (50%). The chest X-ray showed suggestive lesions in 60.7% of cases. CT scans revealed nodules with cavitation in 65% of cases, a halo sign in 20% of cases, and nodules in 15% of cases. Galactomannan antigenemia was positive in 88%, mycological examination positive in 51.6%, and seroconversion was noted in 35.7% of the cases. Invasive pulmonary aspergillosis was classified, according to EORTC/MSG criteria, as probable in 26 cases, possible in one case, and proven in one case. Aspergillus flavus was the dominant species in pulmonary invasive aspergillosis accounting for 73.7% of isolates. Extrapulmonary involvement was suggested in 39.3% of cases, the most frequent were sinusitis and brain abscess. Primary cutaneous aspergillosis was observed in one case. The overall mortality rate was 64.2%; the 12-week survival rate was 71.4%. CONCLUSION: Our results are correlated to published data. A. flavus was the most frequent species in our region.

[Mycological and epidemiological aspects of tinea capitis in the Sousse region of Tunisia]. / Aspects mycologiques et épidémiologiques des teignes du cuir chevelu dans la région de Sousse (Tunisie).

AIM: Tinea capitis continues to be considered a public health problem in Tunisia. The purpose of our study was to investigate trends in the incidence and the mycological and epidemiological aspects of tinea capitis in the Sousse region (Central Tunisia). METHOD: Our work is a retrospective study concerning all scalp samples taken by the parasitology laboratory of the Farhat Hached Hospital in Sousse, Tunisia, over a 26-year period (1983-2008). RESULTS: A total of 10,505 specimens were examined. Of these, 5593 were positive with positive direct examination and/or positive culture. The average incidence was 215 cases per year. Patients were aged under 12 years in 89.3% of cases. A total of 175 cases of tinea capitis in adults were diagnosed. Ten dermatophyte species were isolated: Trichophyton (T.) violaceum (66.7%), Microsporum (M.) canis (29.3%), T. schoenleinii (1.6%), T. mentagrophytes (1.1%), T. verrucosum (0.6%), T. tonsurans (0.2%), T. rubrum (0.2%), M. gypseum (0.1%), M. audouinii (0.03%) and M. nanum (0.01%). CONCLUSION: Our study showed a decrease in the annual incidence of tinea capitis over the study period with an evident decrease in trichophytic tinea and disappearance of favus giving way to microsporic and inflammatory tinea.

Recruitment of SLP-76 to the membrane and glycolipid-enriched membrane microdomains replaces the requirement for linker for activation of T cells in T cell receptor signaling.

Two hematopoietic-specific adapters, src homology 2 domain-containing leukocyte phosphoprotein of 76 kD (SLP-76) and linker for activation of T cells (LAT), are critical for T cell development and T cell receptor (TCR) signaling. Several studies have suggested that SLP-76 and LAT function coordinately to promote downstream signaling. In support of this hypothesis, we find that a fraction of SLP-76 localizes to glycolipid-enriched membrane microdomains (GEMs) after TCR stimulation. This recruitment of SLP-76 requires amino acids 224-244. The functional consequences of targeting SLP-76 to GEMs for TCR signaling are demonstrated using a LAT/SLP-76 chimeric protein. Expression of this construct reconstitutes TCR-inducted phospholipase Cgamma1 phosphorylation, extracellular signal-regulated kinase activation, and nuclear factor of activated T cells (NFAT) promoter activity in LAT-deficient Jurkat T cells (J.CaM2). Mutation of the chimeric construct precluding its recruitment to GEMs diminishes but does not eliminate its ability to support TCR signaling. Expression of a chimera that lacks SLP-76 amino acids 224-244 restores NFAT promoter activity, suggesting that if localized, SLP-76 does not require an association with Gads to promote T cell activation. In contrast, mutation of the protein tyrosine kinase phosphorylation sites of SLP-76 in the context of the LAT/SLP-76 chimera abolishes reconstitution of TCR function. Collectively, these experiments show that optimal TCR signaling relies on the compartmentalization of SLP-76 and that one critical function of LAT is to bring SLP-76 and its associated proteins to the membrane.

[Hepatic CoA availability in the use of long-chain and medium-chain triglycerides]. / Untersuchungen zur hepatischen CoA-Verfügbarkeit bei Verwendung langkettiger (LCT) bzw. mittelkettiger (MCT) Triglyzeride.

Medium chain fatty acids are activated in contrast to long chain fatty acids within the mitochondrial matrix space to acyl-CoA. Therefore they are considered independent from the carnitine transfer system. Using the model of the isolated perfused rat liver, the influence of LCT and MCT on the hepatic CoA-availability was tested by means of the CoA dependent benzoate induced hippurate formation. During the perfusion with MCT only 1/3 of the amount of hippuric acid was formed compared to the effect of LCT. This result could be confirmed in surgical patients under total parenteral nutrition including MCT respectively LCT. The results of our investigations suggest, that the use of MCT leads to a lower hepatic CoA-availability when compared to LCT.