[Which sample for the transport of mycoplasma, eSwab® or dry swab?] / Quel prélèvement pour le transport des mycoplasmes, eSwab® ou écouvillon sec ?

Mycoplasma hominis (MH) and Ureaplasma urealyticum (UU), belonging to mycoplasmas, are implicated in genital and urinary infections. These bacteria are extremely sensitive to environmental factors but remain detectable by culture methods. This study aimed to compare performance of detection on samples performed on eSwab® or dry swabs. Eighty-five genital samples were prospectively collected on dry- and e-Swab, at the Dynabio Croix-Rousse laboratory (Lyon, France), from January to March 2017, searching for mycoplasma infection. After incubation for 48 hours, cultures were qualitatively and quantitatively analyzed by a single qualified operator. On these samples, 23 specimens sampled on dry swabs were positive for UU and 2 for MH (versus 26 and 4 for eSwab). Quantification on eSwab® and dry swabs were statistically correlated (r=0.9118; and r=0.7155; p< 0.01 respectively) without discrepant results. No sample was double-positive during this study. With an important sensitivity (without alteration of the bacterial quantification) and regarding to the gravity of this infection on at-risk patients, as young and/or pregnant woman, the eSwab® sampling seem to improve the pre-analytic phase. However, the benefice to use these sampling methods for long-term conservations has to be evaluated.

Homology modelling and conformational analysis of IgE-binding epitopes of Ara h 3 and other legumin allergens with a cupin fold from tree nuts.

Linear IgE-binding epitopes identified in legumin allergens of peanut (Ara h 3) and other allergenic tree nuts (Jug r 4 of walnut, Cor a 9 of hazelnut, Ana o 2 cashew nut) were mapped on three-dimensional models of the proteins built up by homology modelling. A conformational analysis revealed that consensual surface-exposed IgE-binding epitopes exhibited some structural homology susceptible to account for the IgE-binding cross-reactivity observed among peanut and tree nut allergens. This structurally related cross-reactivity seems irrespective of the botanical origin of the allergens and thus demands that persons allergic to peanut avoid other three nuts to prevent possible allergic reactions. IgE-binding epitopes similar to those found in 11S globulin allergens do not apparently occur in other vicilin allergens with the cupin fold from peanut (Ara h 1) or tree nuts (Jug r 2 of walnut, Cor a 1 of hazel nut, Ana o 3 of cashew nut).