Impact of the thermal treatment of pig slurry on vegetative and spore forming bacteria

Microbiological risk from pig slurry is considered a major public health problem, as pathogenic microorganisms can be spread from land application of manure. Furthermore, with growing demand of water quality for domestic and industrial use, it is becoming necessary to find reliable methods for sanitisation that are economically acceptable. In this context, the aim of this study was to establish the effectiveness of thermal sanitation of pig slurry. The continuous pilot plant 115 litres/hour) used in this study, comprised two tubular heat exchangers followed by hot liquid retention set at 10 minutes

BMJ Med

OBJECTIVE: To evaluate the efficacy of covid-19 convalescent plasma to treat patients admitted to hospital for moderate covid-19 disease with or without underlying immunodeficiency (CORIPLASM trial). DESIGN: Open label, randomised clinical trial. SETTING: CORIMUNO-19 cohort (publicly supported platform of open label, randomised controlled trials of immune modulatory drugs in patients admitted to hospital with moderate or severe covid-19 disease) based on 19 university and general hospitals across France, from 16 April 2020 to 21 April 2021. PARTICIPANTS: 120 adults (n=60 in the covid-19 convalescent plasma group, n=60 in the usual care group) admitted to hospital with a positive SARS-CoV2 test result, duration of symptoms 40. MAIN OUTCOME MEASURES: Primary outcomes were proportion of patients with a WHO Clinical Progression Scale score of ≥6 on the 10 point scale on day 4 (higher values indicate a worse outcome), and survival without assisted ventilation or additional immunomodulatory treatment by day 14. Secondary outcomes were changes in WHO Clinical Progression Scale scores, overall survival, time to discharge, and time to end of dependence on oxygen supply. Predefined subgroups analyses included immunosuppression status, duration of symptoms before randomisation, and use of steroids. RESULTS: 120 patients were recruited and assigned to covid-19 convalescent plasma (n=60) or usual care (n=60), including 22 (covid-19 convalescent plasma) and 27 (usual care) patients who were immunocompromised. 13 (22%) patients who received convalescent plasma had a WHO Clinical Progression Scale score of ≥6 at day 4 versus eight (13%) patients who received usual care (adjusted odds ratio 1.88, 95% credible interval 0.71 to 5.24). By day 14, 19 (31.6%) patients in the convalescent plasma group and 20 (33.3%) patients in the usual care group needed ventilation, additional immunomodulatory treatment, or had died. For cumulative incidence of death, three (5%) patients in the convalescent plasma group and eight (13%) in the usual care group died by day 14 (adjusted hazard ratio 0.40, 95% confidence interval 0.10 to 1.53), and seven (12%) patients in the convalescent plasma group and 12 (20%) in the usual care group by day 28 (adjusted hazard ratio 0.51, 0.20 to 1.32). In a subgroup analysis performed in patients who were immunocompromised, transfusion of covid-19 convalescent plasma was associated with mortality (hazard ratio 0.39, 95% confidence interval 0.14 to 1.10). CONCLUSIONS: In this study, covid-19 convalescent plasma did not improve early outcomes in patients with moderate covid-19 disease. The efficacy of convalescent plasma in patients who are immunocompromised should be investigated further. TRIAL REGISTRATION: ClinicalTrials.gov NCT04345991

Contribution a l'etude de l'origine (humaine ou animale) de la contamination fecale des eaux de surface

SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : T 78056 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Modélisation du plancton dans une retenue oligotrophe : Sainte-Croix sur le Verdon

Un modèle biologique a été développé en vue de représenter le fonctionnement de l'écosystème planctonique dans la retenue oligotrophe de Sainte-Croix. II a une structure physique simplifiée (modèle bicouche) qui simule la stratification thermique saisonnière. Ce modèle a représenté correctement les principales poussées planctoniques. L'étude a également mis en évidence l'importance de la fermeture du modèle : il s'agit de la prédation par le zooplancton dans ce cas. Le rôle primordial des variables physiques (température, stratification thermique verticale), notamment dans l'évolution du stock de nutriments, confirme la nécessité de coupler les processus physiques et biologiques dans un modèle écologique

Transcriptomic Analysis of the Adaptation of Listeria monocytogenes to Lagoon and Soil Matrices Associated with a Piggery Environment: Comparison of Expression Profiles

Understanding how Listeria monocytogenes, the causative agent of listeriosis, adapts to the environment is crucial. Adaptation to new matrices requires regulation of gene expression. To determine how the pathogen adapts to lagoon effluent and soil, two matrices where L. monocytogenes has been isolated, we compared the transcriptomes of L. monocytogenes CIP 110868 20 min and 24 h after its transfer to effluent and soil extract. Results showed major variations in the transcriptome of L. monocytogenes in the lagoon effluent but only minor modifications in the soil. In both the lagoon effluent and in the soil, genes involved in mobility and chemotaxis and in the transport of carbohydrates were the most frequently represented in the set of genes with higher transcript levels, and genes with phage-related functions were the most represented in the set of genes with lower transcript levels. A modification of the cell envelop was only found in the lagoon environment. Finally, the differential analysis included a large proportion of regulators, regulons, and ncRNAs

Pig Manure Contamination Marker Selection Based on the Influence of Biological Treatment on the Dominant Fecal Microbial Groups▿

The objective of this study was to identify a microbial marker for pig manure contamination. We quantified the persistence of four dominant bacterial groups from the pig intestinal tract throughout manure handling at 10 livestock operations (including aerobic digestion) by using molecular typing. The partial 16S rRNA genes of Bacteroides-Prevotella, Eubacterium-Clostridiaceae, Bacillus-Streptococcus-Lactobacillus (BSL), and Bifidobacterium group isolates were amplified and analyzed by capillary electrophoresis single-strand conformation polymorphism. The most dominant bacterial populations were identified by cloning and sequencing their 16S rRNA genes. The results showed that Bifidobacterium spp. and, to a lesser extent, members of the BSL group, were less affected by the aerobic treatment than either Eubacterium-Clostridiaceae or Bacteroides-Prevotella. Two Bifidobacterium species found in raw manure were still present in manure during land application, suggesting that they can survive outside the pig intestinal tract and also survive aerobic treatment. The 16S-23S rRNA internal transcribed spacer of one species, Bifidobacterium thermacidophilum subsp. porcinum, was sequenced, and a specific pair of primers was designed for its detection in the environment. With this nested PCR assay, this potential marker was not detected in samples from 30 bovine, 30 poultry, and 28 human fecal samples or in 15 urban wastewater effluents. As it was detected in runoff waters after spreading of pig manure, we propose this marker as a suitable microbial indicator of pig manure contamination

Impact du compostage sur l’antibiorésistance: Chapitre 9

National audienc

VBNC state and ‘regrowth’ during waste treatment: factors playing a role in loss of culturability of pathogenic bacteria seeded in digestates from agricultural biogas plants

During treatment of organic waste by anaerobic digestion, composting or in wastewater treatment plants, pathogenic bacteria are submitted to various biotic and abiotic stress. In treated wastes (digestates, composts…) increase of bacterial counts obtained by culture for indicators (E. coli) and pathogenic bacteria (Salmonella sp., Shigella sp., Listeria monocytogenes) are sometimes recorded, but the underlying mechanisms remain unknown. Some recent studies indicate that this may be due to the induction of Viable but Non-Culturable (VBNC) state during treatment, followed by ‘resuscitation’ during storage of treated products. Here, a microcosm approach was used to evaluate the persistence of three pathogenic bacteria (Salmonella Derby, Campylobacter coli and Listeria monocytogenes) in digestates from agricultural wastes, stored for later land spreading. Nine samples, including raw digestates, liquid fractions of digestate and composted digestates, were inoculated with each pathogen and maintained for 40 days at 24°C. Concentrations of pathogens were monitored using culture and qPCR methods. In some digestates, the concentration of the pathogens by qPCR assay was several orders of magnitude higher than the concentration of culturable cells, suggesting a potential loss of culturability and induction of VBNC state. The potential VBNC state which was generally not observed in the same digestate for the three pathogens, occurred more frequently for C. coli and L. monocytogenes than for Salmonella Derby. The effect of NH4+/NH3 on the culturability of C. coli and Salmonella Derby was also shown. Our results underline the importance of considering VBNC cells when evaluating the sanitary effect of an anaerobic digestion process and the persistence of pathogens during the storage of digestates and subsequent land spreading