Qualité microbiologique du lait cru ovin collecte dans la steppe centrale de l’Algérie

L’objectif de l’étude consiste à évaluer la qualité microbiologique du lait cru ovin collecté localement, en milieu steppique Algérien dans la région de Djelfa situé à 300 km au sud d’Alger. Au total 51 échantillons de lait ont été prélevés pour des fins analytiques. La contamination moyenne est de 2,3.107 cfu/mL pour la flore totale contre 1,1.105 pour les coliformes totaux et 1,5.104 pour les coliformes fécaux. Pour la flore fongique, les laits sont plus contaminés en levures qu’en moisissures (2,4.105 vs 3,4.103 germes/mL respectivement). Les Streptocoques fécaux sont détectés chez 43,14% des échantillons par contre E.coli n’est décelée que chez 17,65% des laits. Par ailleurs, 28% des prélèvements sont positifs vis-à-vis de Clostridium contre 9,8% pour Staphylococcus aureus. En revanche, tous les laits sont exempts de Salmonella. Pour ce qui est de la recherche des anticorps brucelliques, 13,73% des laits analysés sont positifs au Ring-test. La mauvaise qualité du lait reflète bien les conditions déplorables de production et la non-observance des bonnes pratiques hygiéniques lors de la traiteMots-clés : brebis, lait cru, qualité hygiénique, microorganismes pathogènes, Algérie.Microbiological quality of raw ewe’s milk in Algerian middle steppeThe objective of this study was to assess the microbiological quality of raw milk sheep collected in Algerian steppe. A total of 51 samples of bulk milk were examined. The results obtained show the unsatisfactory quality of milk analyzed. The average contamination is 2,3.107 cfu/ml for the total flora against 1,1.105 for total coliforms and 1,5.104 for fecal coliforms. For the fungal flora, milk is more contamined with yeast than fungi (2,4.105 vs 3,4.103 germes/ml respectively). Fecal streptococci were detected in 43,14% of the samples were E.coli is detected in 17,65% of the milk. In addition, 28% of samples are positive for Clostridium against 9,8% for Staphylococcus aureus. All milk are free from Salmonella. In terms of Brucella antibody, 13,73% of milk are ring test positive. The poor quality of milk reflects the deplorable conditions of production and non-observance of good hygiene practices during milking.Keywords : Ewe, Raw milk, Hygienic quality, Pathogens, Algeria

Profils en acides gras libres, cholestérol et indices lipidiques du lait cru ovin issu de deux races algériennes (Ouled-Djellal et Rumbi) collecté en milieu steppique

Free fatty acid profiles and cholesterol and lipid indexes of raw ewe's milk from two Algerian breeds (Ouled-Djellal and Rumbi), collected in the steppe area. Description of the subject. This article aims to characterize the fat content of raw ewe's milk, collected locally in the Algerian central steppe, an area highly appreciated for its production of smen (traditional butter). Objectives. The objective of this study was to investigate the free fatty acid profile and the cholesterol and lipid indexes of raw ewe's milk from two Algerian local breeds (Ouled-Djellal and Rumbi). Method. Milk was collected from 20 ewes of each breed three times during the middle stage of lactation. The milk fat was extracted using the Rose-Gottlieb method. Fatty acids were analyzed by gas chromatography. Results. Palmitic (24.4% ± 3.3), oleic (24.2% ± 4.6), stearic (10.8% ± 3.5), myristic (10.4% ± 1.9) and capric (8.3% ± 3.5) acids dominated and accounted for 78.1% of the total fatty acids. Saturated fatty acids predominated compared to unsaturated fatty acids (69.6% ± 5.3 vs 30.8% ± 5.1), and monounsaturated fatty acids outweighed the polyunsaturated (26.3% ± 4.7 vs 4.5% ± 1.1). The Ouled-Djellal milk had a higher short-chain fatty acid content than the Rumbi milk (p < 0.05). On the other hand, the Rumbi milk was richer in medium chain fatty acids. The two types of milk differed significantly regarding their palmitic and palmitoleic acid content (p < 0.05). Within the long chain of fatty acids, only the stearic acid (10.88% ± 2.83 vs 12.34% ± 2.75; p < 0.01) and the arachidic acid (0.26% ± 0.18 vs 0.35% ± 0.09; p < 0.05) were influenced by the breed. Conclusions. Results showed that milk from the Rumbi ewe was richer in fatty acids than the milk from the Ouled-Djellal and that Rumbi ewe's milk may be of value in dairy technology due to the socio-economic impact that it can generate

Inflammation and sepsis as part of hematopoietic stem cell transplantation: a transcriptomic approach

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Aldehyde dehydrogenases inhibition eradicates leukemia stem cells while sparing normal progenitors

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Natural killer cells in acute myeloid leukemia patients: from phenotype to transcriptomic analysis

International audienceChemotherapies allow complete remission in more than 50 % of patients with acute myeloid leukemia (AML), however, with frequent relapse. This suggests that residual leukemic cells may escape to chemotherapy and immune system. Natural killer (NK) cells from AML patients (AML-NK) have a weaker natural cytotoxicity-activating receptors (NCRs) expression than NK cells from healthy donors (HD-NK). Coding genes for NCR1/NKp46, NCR2/NKp44 and NCR3/NKp30 are located at different loci on two different chromosomes; however, their expression is tightly coordinated. Most NK cells express either high (NCRbright) or low levels (NCRdull) of all three NCRs. This suggests the existence of negative/positive regulation factor(s) common to the three receptors. In order to find transcription factor(s) or pathway(s) involved in NCRs co-regulation, this study compared the transcriptomic signature of HD-NK and AML-NK cells, before and after in vitro NK cells culture. Microarrays analysis revealed a specific NK cells transcriptomic signature in patients with AML. However, in vitro NK cells expansion erased this signature and up-regulated expression of central molecules of NK functions, such as NCR, NKG2D and also ETS-1, regardless of their origin, i.e., AML-NK vs HD-NK. ETS-1 transcription factor was shown to bind to a specific and common region in the NCRs promoters, thus appearing as a good candidate to explain the coordinated regulation of three NCRs. Such results are encouraging regarding in vitro AML-NK cytotoxicity restoration and provide a new conceptual support for innovative cellular therapy based on in vitro NK cells expansion before their reinfusion in AML patients