From the importance of organic carbon in reproduction tests with Eisenia fetida

The standard Eisenia fetida chronic toxicity reproduction test is normalized and needs up to 8 weeks of experimentation. Many matrixes have shown toxic effects on the earthworms' survey, growth and reproduction. But the food factor may affect the organisms' responses to contaminated media in such tests. We try to evaluate the effect, or not, of the organic carbon content present in the environment, as spreadable organic wastes added in soil, on the reproduction test of Eisenia fetida. We confirm the influence of the organic matter content on earthworm reproduction. This "food" factor must be considered when studying environmental samples rich in organic matter, since that could mask potentially harmful effects. To minimize this potential "food" effect during reproduction tests, we recommend an inverse gradient of organic matter contribution by the "horse dung" food applied in all conditions according to the dose of agricultural amendments tested.

Influence of edaphic conditions and persistent organic pollutants on earthworms in an infiltration basin

In recent decades, stormwater management has developed to allow stormwater to infiltrate directly into the soils instead of being collected and routed to sewer systems. However, during infiltration, stormwater creates a sediment deposit at the soil surface as the result of high loads of suspended particles (including pollutants), leading to the settlement of sedimentary layers prone to colonization by plants and earthworms. This study aims to investigate the earthworm communities of a peculiar infiltration basin and investigate the influence of edaphic conditions (water content, organic matter content, pH, height of sediment) and of persistent organic pollutants (POPs: PCBs, PCDDs and PCDFs) on these earthworms. Attention was paid to their age (juveniles or adults) and their functional group (epigeic, endogeic, anecic). We found that the earthworm abundance was mostly driven by edaphic conditions, with only a slight impact of POPs, with a significant negative impact of PCBDLno for juveniles and endogeic, and PCDDs for epigeic. On the contrary, the height of the sediment and the water content are beneficial for their presence and reproduction. Furthermore, POPs contents are also linked to physicochemical parameters of the sediment. Bioaccumulation was clearly revealed in the studied site but does not differ between juveniles and adults, except for PCDDs. Conversely, BAF values seemed to vary between functional groups, except for PCBDL non-ortho. It strongly varies with the family types (PCBs versus PCCD/Fs) and between congeners within the same family, with specific strong bioaccumulation for a few congeners.

Risk factors of Pneumocystis pneumonia in solid organ recipients in the era of the common use of posttransplantation prophylaxis

Pneumocystis pneumonia (PCP) in solid organ transplant (SOT) recipients becomes rare in the immediate posttransplantation period thanks to generalized prophylaxis. We aimed to identify the predictive factors for PCP in the era of universal prophylaxis and to propose a strategy for preventing PCP beyond the first year after transplantation. In a retrospective case-control study, 33 SOT cases with PCP diagnosed between 2004 and 2010 were matched with two controls each to identify risk factors for PCP by uni- and multivariate analysis. All the patients benefited from 6 months of posttransplantation trimethoprim-sulfamethoxazole prophylaxis. Most PCP in SOT patients occurred during the second year posttransplantation (33%). By univariate analysis, age, nonuse of tacrolimus, total and CD4 lymphocyte counts, gamma-globulin concentration and cytomegalovirus (CMV) infection appeared to be PCP risk factors. In the final multivariate analysis, age (adjusted odds ratio [OR] 3.7, 95% confidence interval [CI]: 1.3-10.4), CMV infection (OR: 5.2, 95% CI: 1.8-14.7) and total lymphocyte count (OR: 3.9, 95% CI: 1.4-10.7) were found to be independently associated with PCP. The second year posttransplantation appeared to be the new period of highest risk of PCP. Age, CMV viremia and lymphocytes were the most pertinent predictive criteria to evaluate the risk of PCP in clinical practice.