Antimicrobial resistant Escherichia coli prevalence in freshwaters in Belgium and human exposure risk assessment

peer reviewedThe objective of this work was to evaluate the antimicrobial resistant (AR) E. coli prevalence in recreational waters in Belgium and to assess the exposure risk for bathers. Nine stations were sampled during the 2021 bathing season. A total of 912 E. coli strains were isolated and tested by the disk diffusion method in accordance with EUCAST recommendations, including ExtendedSpectrum Beta-Lactamase (ESBL) production. AR E. coli were counted at each bathing sites, 24% of strains were resistant to at least one antibiotic and 6% were Multi-Drug Resistant (MDR). A Multiple Antibiotic Resistance (MAR) index was calculated to compare the bathing sites. The Lesse river had the highest MAR index as well as the highest E. coli absolute abundance and the largest number of ESBL-producing E. coli. Conversely, the 3 lakes showed lower E. coli contamination levels and AR rates. A human health risk assessment of exposure to AR E. coli, based on the calculation of measured prevalence, was performed considering four different dose-response model scenarios. The human health risk (Pd) ranged from 10− 9 to 0.183 (children). The exposure probabilities were low, except for scenario 3 (E. coli O157:H7), which is the most severe

Influence des inclusions sur la fissuration de composites cimentaires en séchage

International audienc

Antimicrobial resistance of Escherichia coli isolated from freshwaters and hospital effluents in Belgium

The purpose of this work was to evaluate the level of antimicrobial resistant Escherichia coli isolates in freshwaters and hospital effluents in Belgium. The samples were collected from 24 locations along the Ourthe, Vesdre, Ambl eve and Meuse rivers and in the wastewater effluents of several hospitals. The sampling stations in rivers were classified according to the dominant land covers of the rivers (rural, urban and forest areas). Two sampling campaigns were organized in May and October 2019 to highlight a possible seasonal effect. A total of 938 E. coli strains were isolated on Chromogenic Selective Tryptone Bile X-glucuronide (TBX) and TBX supplemented with amoxicillin (TBX+AMX) media. Disk diffusion assays were performed following the EUCAST’s recommendations to assess the antimicrobial resistance against 12 antibiotics. A total of 32 7% of strains were at least resistant to one antibiotic and 24 6% were multiple antimicrobial resistant strains on TBX. The highest resistance rates were found for ampicillin (AMP), amoxicillin coupled with clavulanic acid (AMC) and sulfamethoxazole/trimethoprim (SXT). The lowest resistance rates were observed for meropenem (MEM) and ertapenem (ETP), which are last resort antibiotics. No significant difference was observed between both campaigns for the resistance rate to antibiotics

Gene transfer of two entry inhibitors protects CD4+ T cell from HIV-1 infection in humanized mice

International audienceTargeting viral entry is the most likely gene therapy strategy to succeed in protecting the immune system from pathogenic HIV-1 infection. Here, we evaluated the efficacy of a gene transfer lentiviral vector expressing a combination of viral entry inhibitors, the C46 peptide (an inhibitor of viral fusion) and the P2-CCL5 intrakine (a modulator of CCR5 expression), to prevent CD4+ T-cell infection in vivo. For this, we used two different models of HIV-1-infected mice, one in which ex vivo genetically modified human T cells were grafted into immunodeficient NOD.SCID.γc−/− mice before infection and one in which genetically modified T cells were derived from CD34+ hematopoietic progenitors grafted few days after birth. Expression of the transgenes conferred a major selective advantage to genetically modified CD4+ T cells, the frequency of which could increase from 10 to 90% in the blood following HIV-1 infection. Moreover, these cells resisted HIV-1-induced depletion, contrary to non-modified cells that were depleted in the same mice. Finally, we report lower normalized viral loads in mice having received genetically modified progenitors. Altogether, our study documents that targeting viral entry in vivo is a promising avenue for the future of HIV-1 gene therapy in humans