SUMMARYPathogens that infect the gastrointestinal and respiratory tracts are subjected to intense pressure due to the environmental conditions of the surroundings. This pressure has led to the development of mechanisms of bacterial tolerance or persistence which enable microorganisms to survive in these locations. In this review, we analyze the general stress response (RpoS mediated), reactive oxygen species (ROS) tolerance, energy metabolism, drug efflux pumps, SOS response, quorum sensing (QS) bacterial communication, (p)ppGpp signaling, and toxin-antitoxin (TA) systems of pathogens, such as , spp., spp., spp., , spp., spp., spp., and , all of which inhabit the gastrointestinal tract. The following respiratory tract pathogens are also considered:, ,, , and Knowledge of the molecular mechanisms regulating the bacterial tolerance and persistence phenotypes is essential in the fight against multiresistant pathogens, as it will enable the identification of new targets for developing innovative anti-infective treatments.

ARTICLE INFO ABSTRACT Keywords:Vegetable fats Milk performance Milk CLA Dairy eweTwo experiments were carried out to study the effects of supplementing the ration of lactating ewes with vegetable fats (sunflower oil, SO or hydrogenated palm oil, HPO; HIDROPALM®) on diet digestibility, milk yield and milk composition, and on the concentration of the conjugated linoleic acid (CLA) C18:2 cis-9 trans-11 and C18:l trans-11 (vaccenic acid, VA) and other main fatty acids in milk fat. Treatments involved a control diet, without added oil, and 2 diets supplemented with either 12g/kg SO or 12g/kg HPO on a dry matter (DM) basis. In the first experiment, 6 non-pregnant, non-lactating Lacaune ewes were used following a 3 x 3 replicated Latin Square design. Addition of vegetable fat supplement to the diet increased digestibility of DM, organic matter (OM) and crude protein (CP), but did not affect that of the ether extract (EE), neutral detergent fibre (NDF) or acid detergent fibre (ADF). In the second experiment, 60 Lacaune dairy ewes mid-way through lactation (120 ±12 days in milk, 0.98 ± 0.03 kg/day average milk yield) were divided into three equalsized groups each of which was assigned to one of the three experimental diets for4 weeks. Compared with the control treatment, supplementation with HPO increased milk yield and energy-corrected milk. But neither vegetable fat supplement modified percentages of fat and protein in milk. Supplementation with HPO increased C14:l, C16:l and C16:0 content and reduced C18:0 and C18:l cis-9 content in milk fat. Supplementation with SO increased the VA content in milk fat by 36% and that of cis-9 trans-11 CLA by 29% in comparison with the control diet. Supplementation with HPO led to milk fat with 15% more cis-9 trans-11 CLA than control milk. In conclusion, adding a moderate dose of HPO or SO to the diets increased CLA concentration in milk fat. Nevertheless, supplementation with SO was more effective than HPO in increasing CLA concentration in milk fat and reducing the atherogenicity index, improving milk quality from the human health standpoint.

ARTICLE INFO ABSTRACTTwenty-seven lambs were used to investigate the effects of the inclusion of 4% hydrogenated palm oil (HPO) or sunflower oil (SFO) in the concentrate on animal performance, carcass and meat quality and fat characteristics and fatty acid composition. Animals (16.2 ±0.27 kg initial weight) were fed concentrate (Control, HPO or SFO) and barley straw ad libitum and slaughtered at 25 kg. SFO lambs tended to eat less concentrate than HPO animals (P< 0.10). Neither HPO nor SFO affected any of the carcass characteristics studied, meat pH and meat and fat colour (P> 0.05). SFO decreased proportions of CI 6:0, CI 8:1 Keywords:císJ 2 and clg;3 ( P< 0>05 ) and i ncrea sed C18:l trans (P< 0.001) and C18:2/C18:3 ratio (P< 0.05). Ath-S flow -, erogenicity index was lower (P< 0.05) when SFO was included in the concentrate. HPO did not affected Fattening lambs anc ' ^FO improved fatty acid composition of fattening lambs without affecting animal performance. Fatty acid Atherogenicity

The purpose of this work was to obtain a cheese from ewes milk with a healthier fatty acid (FA) profile. To achieve our aim, 48 ewes (12 per treatment) were fed diets supplemented with 3% of plant oils: palm (used as control), olive (OO), soybean (SO), and linseed (LO). Milk samples from each treatment were collected to manufacture cheeses. The cheesemaking process did not modify the dairy fat FA profile, but OO, SO, and LO did reduce the C12:0 + C14:0 + C16:0 content in dairy fat, thus decreasing the atherogenic index value in the cheeses. Percentages of cis-9 trans-11 C18:2 in cheeses ranged from the 0.43 control value to 0.92, 1.64, and 2.71 with OO, LO, and SO respectively, following the same pattern as trans-11 C18:1. In contrast, trans-10 C18:1 levels were always below 1%. The lowest n-6/n-3 ratio obtained with LO (1.43) suggests that such lipid supplementation would be the most effective nutritional strategy for improving cheese FA profiles.

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