Les probiotiques: Seraient-ils la nouvelle génération naturelle des cofacteurs promoteurs de croissance chez le poulet de chair ?

Growth promoter antibiotics (GPAs) play an important role in improving growth performances by preventing intestinal pathogenic bacteria proliferation such us Escherichia coli, Salmonella and clostridium. However, the large use of GPAs led to antibio-resistance and residues in both food of poultry origin (offal...) and environment which has negative effects on public health and meat quality. Thus, several clinical trials have been conducted to evaluate the effects of potential alternatives to ban GPAs’ use in poultry breeding. In fact, effects of those alternatives on gut health and growth performances, have been reported to be similar at GPAs especially ensuring intestinal microbiota balance and improving gut health and zootechnical performances. Thus, there is a need for further investigations to determine: strains, doses, synergistic combination, administration’ moment and cost of the probiotics per bird to establish appropriate protocols. The current review paper sheds light on the different aspects that define probiotics, going from their mechanism of action and their effects on zootechnical parameters and the digestive health on broilers to conclude with an overview on the economic indicators that succeed in their use and the revolutionary concept of the Ovo-feed.  Key words: GPA, probiotics, broilers, gut health, growth performancesDepuis leur apparition, les antibiotiques promoteurs de croissance (APC) ont joué un rôle crucial dans l’amélioration des performances zootechniques à travers la prévention de la prolifération des bactéries pathogènes au niveau intestinal du poulet, notamment Escherichia coli, salmonelles et clostridies. Les différentes investigations scientifiques ont prouvé que leur utilisation à grande échelle a engendré une antibio-résistance et des résidus dans l’environnement, la viande et les denrées alimentaires d’origine avicole (abats...) ce qui peut se répercuter négativement sur la santé publique et l’image de qualité de ces produits.  Par conséquent, il était primordial de trouver des alternatives potentielles aux antibiotiques promoteurs de croissance afin de bannir leur utilisation en élevage avicole. On compte parmi ces produits précédemment cités, une multitude de substances et de micro-organismes, notamment les probiotiques. En effet, ces substituts ont prouvé leur faculté à égaler les effets escomptés par un APC à savoir assurer un bon équilibre du microbiote intestinal et améliorer la santé digestive et les performances zootechniques. Ainsi, il serait très lucide d’approfondir les investigations afin de déterminer la souche, la dose, le moment d’administration, les associations synergiques avec d’autre produits alternatifs ainsi que le coût de revient par individu des probiotiques afin d’établir un protocole d’usage en fonction des effets souhaités. L’objectif de ce travail est de mettre l’accent sur les différents volets qui définissent les probiotiques et ce en allant de leur mécanisme d’action et leurs effets sur les paramètres zootechniques et la santé digestive du poulet de chair pour conclure avec un aperçu sur les indicateurs économiques qui succèdent à leur usage tout en passant par un léger préambule sur le concept révolutionnaire de l’Ovo-feeding. Mots clés : APC, probiotiques, poulet de chair, santé digestive, performances de croissance

HYPOGLYCEMIC EFFECT OF LUPIN ALKALOIDS AND/OR ROSIGLITAZONE IN PREGNANT DIABETIC RATS IN RELATION TO ATHEROGENIC INDEX

Diabetes (DM) is a group of metabolic disorders characterized by hyperglycemia resulting from defects in insulin secretion and/ or insulin action. It can be classified into; type 1 (T1DM) Type 2 DM, type 2 (T2DM), gestational diabetes and other specific types of diabetes. Diabetes is the most common pre-existing medical condition complicating pregnancy. Insulin resistance is associated with both type two diabetes and dislypedemia. This study aims to evaluate the changes in the homeostasis model assessment of insulin resistance (HOMA- IR) and indices of atherogenic lipid profile parameters in pregnant diabetic rats after the administration of Rosiglitazone and /or alkaloid lupine extract. Blood glucose, hemoglobin content (Hb), lipid profile, insulin and glucagon concentrations were investigated at 20th day of gestation. The results revealed the improvement of HOMA-IR and The control of the hyperglycemic status in all treated group. Also, there are an increase in insulin concentration, and a decrease in glucagon concentration in all treated groups, in comparison to, STZ group. Meanwhile, it showed alternation in the atherogenic profile in Rosiglitazone treated groups, in comparison to, lupin treated groups. The correlations among (HOMA-IR and HDL), (AIP and LDL) and (glucose and Hb) were observed in our study at (r = 0.594, p< 0.01), (r = 0.690, p< 0.01), and (r = 0.811, p< 0.01) respectively. The usage of lupine alkaloids to treating type two diabetes during the pregnancy is more favorable to avoid Rosiglitazone side effects. More studies are needed to explore the effect of Rosiglitazone on lipids and cardiovascular risk

Case Reports1. A Late Presentation of Loeys-Dietz Syndrome: Beware of TGFβ Receptor Mutations in Benign Joint Hypermobility

Background: Thoracic aortic aneurysms (TAA) and dissections are not uncommon causes of sudden death in young adults. Loeys-Dietz syndrome (LDS) is a rare, recently described, autosomal dominant, connective tissue disease characterized by aggressive arterial aneurysms, resulting from mutations in the transforming growth factor beta (TGFβ) receptor genes TGFBR1 and TGFBR2. Mean age at death is 26.1 years, most often due to aortic dissection. We report an unusually late presentation of LDS, diagnosed following elective surgery in a female with a long history of joint hypermobility. Methods: A 51-year-old Caucasian lady complained of chest pain and headache following a dural leak from spinal anaesthesia for an elective ankle arthroscopy. CT scan and echocardiography demonstrated a dilated aortic root and significant aortic regurgitation. MRA demonstrated aortic tortuosity, an infrarenal aortic aneurysm and aneurysms in the left renal and right internal mammary arteries. She underwent aortic root repair and aortic valve replacement. She had a background of long-standing joint pains secondary to hypermobility, easy bruising, unusual fracture susceptibility and mild bronchiectasis. She had one healthy child age 32, after which she suffered a uterine prolapse. Examination revealed mild Marfanoid features. Uvula, skin and ophthalmological examination was normal. Results: Fibrillin-1 testing for Marfan syndrome (MFS) was negative. Detection of a c.1270G > C (p.Gly424Arg) TGFBR2 mutation confirmed the diagnosis of LDS. Losartan was started for vascular protection. Conclusions: LDS is a severe inherited vasculopathy that usually presents in childhood. It is characterized by aortic root dilatation and ascending aneurysms. There is a higher risk of aortic dissection compared with MFS. Clinical features overlap with MFS and Ehlers Danlos syndrome Type IV, but differentiating dysmorphogenic features include ocular hypertelorism, bifid uvula and cleft palate. Echocardiography and MRA or CT scanning from head to pelvis is recommended to establish the extent of vascular involvement. Management involves early surgical intervention, including early valve-sparing aortic root replacement, genetic counselling and close monitoring in pregnancy. Despite being caused by loss of function mutations in either TGFβ receptor, paradoxical activation of TGFβ signalling is seen, suggesting that TGFβ antagonism may confer disease modifying effects similar to those observed in MFS. TGFβ antagonism can be achieved with angiotensin antagonists, such as Losartan, which is able to delay aortic aneurysm development in preclinical models and in patients with MFS. Our case emphasizes the importance of timely recognition of vasculopathy syndromes in patients with hypermobility and the need for early surgical intervention. It also highlights their heterogeneity and the potential for late presentation. Disclosures: The authors have declared no conflicts of interes

Risk of COVID-19 after natural infection or vaccinationResearch in context

Background: While vaccines have established utility against COVID-19, phase 3 efficacy studies have generally not comprehensively evaluated protection provided by previous infection or hybrid immunity (previous infection plus vaccination). Individual patient data from US government-supported harmonized vaccine trials provide an unprecedented sample population to address this issue. We characterized the protective efficacy of previous SARS-CoV-2 infection and hybrid immunity against COVID-19 early in the pandemic over three-to six-month follow-up and compared with vaccine-associated protection. Methods: In this post-hoc cross-protocol analysis of the Moderna, AstraZeneca, Janssen, and Novavax COVID-19 vaccine clinical trials, we allocated participants into four groups based on previous-infection status at enrolment and treatment: no previous infection/placebo; previous infection/placebo; no previous infection/vaccine; and previous infection/vaccine. The main outcome was RT-PCR-confirmed COVID-19 >7–15 days (per original protocols) after final study injection. We calculated crude and adjusted efficacy measures. Findings: Previous infection/placebo participants had a 92% decreased risk of future COVID-19 compared to no previous infection/placebo participants (overall hazard ratio [HR] ratio: 0.08; 95% CI: 0.05–0.13). Among single-dose Janssen participants, hybrid immunity conferred greater protection than vaccine alone (HR: 0.03; 95% CI: 0.01–0.10). Too few infections were observed to draw statistical inferences comparing hybrid immunity to vaccine alone for other trials. Vaccination, previous infection, and hybrid immunity all provided near-complete protection against severe disease. Interpretation: Previous infection, any hybrid immunity, and two-dose vaccination all provided substantial protection against symptomatic and severe COVID-19 through the early Delta period. Thus, as a surrogate for natural infection, vaccination remains the safest approach to protection. Funding: National Institutes of Health

Risk of COVID-19 after natural infection or vaccinationResearch in context

Summary: Background: While vaccines have established utility against COVID-19, phase 3 efficacy studies have generally not comprehensively evaluated protection provided by previous infection or hybrid immunity (previous infection plus vaccination). Individual patient data from US government-supported harmonized vaccine trials provide an unprecedented sample population to address this issue. We characterized the protective efficacy of previous SARS-CoV-2 infection and hybrid immunity against COVID-19 early in the pandemic over three-to six-month follow-up and compared with vaccine-associated protection. Methods: In this post-hoc cross-protocol analysis of the Moderna, AstraZeneca, Janssen, and Novavax COVID-19 vaccine clinical trials, we allocated participants into four groups based on previous-infection status at enrolment and treatment: no previous infection/placebo; previous infection/placebo; no previous infection/vaccine; and previous infection/vaccine. The main outcome was RT-PCR-confirmed COVID-19 >7–15 days (per original protocols) after final study injection. We calculated crude and adjusted efficacy measures. Findings: Previous infection/placebo participants had a 92% decreased risk of future COVID-19 compared to no previous infection/placebo participants (overall hazard ratio [HR] ratio: 0.08; 95% CI: 0.05–0.13). Among single-dose Janssen participants, hybrid immunity conferred greater protection than vaccine alone (HR: 0.03; 95% CI: 0.01–0.10). Too few infections were observed to draw statistical inferences comparing hybrid immunity to vaccine alone for other trials. Vaccination, previous infection, and hybrid immunity all provided near-complete protection against severe disease. Interpretation: Previous infection, any hybrid immunity, and two-dose vaccination all provided substantial protection against symptomatic and severe COVID-19 through the early Delta period. Thus, as a surrogate for natural infection, vaccination remains the safest approach to protection. Funding: National Institutes of Health