INVESTIGADORES
OTERO Maria Claudia
congresos y reuniones científicas
Título:
ADVANCES IN THE DESIGN OF PROBIOTIC PRODUCTS FOR THE PREVENTION OF MAJOR DISEASES IN DAIRY CATTLE
Autor/es:
NADER-MAC¨ªAS, M. ELENA; OTERO, M. CLAUDIA; ESPECHE, M. CAROLINA; MALDONADO, NATALIA
Lugar:
Sevilla, España
Reunión:
Conferencia; Bio Micro World 2007; 2007
Resumen:
The infection diseases with higher incidence in dairy cattle that cause the main economic losses in farms, involve both adults and neonates. They are mastitis, endometritis and calf diarrhea, and affect the productivity parameters as well as the fertility degree: calving to conception intervals, first service conception rate. Also, those associated with milk production: average milk production (Kg), average fat and protein content (%), and others such as calf mortality rate (%) and calf birth weight (Kg). Traditional veterinary medicine is focused upon diagnostics and antibiotic therapeutic application that produce residues in food animal products and cross resistance between zoonotic pathogens and human colonizing micro organisms. The new concept of health management has been defined as the promotion of health, improvement of productivity, and prevention of diseases in animals within the economic frame work. It also includes the animal¡¯s welfare, food safety, public health and environmental sustainability. For the above reasons, there is a wide interest to apply alternative therapies that includes the use of probiotic (live micro organisms that, when administered in adequate amounts confer a health benefit on the host) to prevent infections in humans and animals, mainly studied in the gastrointestinal and urogenital tracts. Based on the host specificity exerted by the indigenous microbiota, in previous works the isolation and identification of the dominant micro organisms from different ecological niches (bovine urogenital tract, mammary gland and newborn oral cavity-faeces) were carried out. The indigenous microbiota that colonize the cow mucosa is stable and include: Gram positive cocci (Staphylococcus spp., Streptococcus spp. and Enterococcus spp) and Lactobacillus spp. Also spore forming Bacillus spp. were isolated from the teat canal and intestinal tract. Some specific and beneficial characteristics were evaluated in all the LAB strains. Our research group is involved in the design of veterinary probiotic products to restore the ecological balance of different tracts for the prevention of infections in dairy cows and calves. Our hypothesis is to promote the colonization of the vaginal mucosa of pregnant cows with specific strains, for the prevention of post-partum metritis. These vaginal probiotic will increase the first contact of these micro organisms with the sterile, unprotected neonate intestinal tract. Later, the calf will be in contact with the mammary gland during the first days of life, when also the intestinal tract-isolated probiotic could be administered to stimulate the immature immune system. The infections of the mammary gland could also be prevented by specific strains. With this basement, the objective of the present work was to perform a comparative evaluation of the beneficial properties of LAB isolated from three different bovine niches (digestive tract, vagina and teat canal). A total of 281 bovine LAB strains were screening for their surface characteristics (degree of hydrophobicity by MATH and bacterial aggregation), antagonistic substances production (lactic acid, hydrogen peroxide and bacteriocin) and pathogens growth inhibition (20 strains of pathogens that cause specific infections to each tract). Most of the strains (80-90%), independently from their origin, showed a low degree of hydrophobicity (¡Ü30%), that suggests this is a characteristic of the microbiota that colonize the cow mucosa. Only 7% of the micro organisms expressed an aggregative phenotype. There was no correlation between both surface properties. The spectrum of antagonistic substances production was different according to the ecological origin of the micro organisms: 95% of vaginal LAB and 67% udder strains showed different degree of H2O2 production, while only 21% of digestive strains express this characteristic. More than 80% of the LAB isolated from vagina and digestive tract produce organic acids, while only 45% from the teat canal released these metabolites. Three strains isolated from the teat canal were able to produce bacteriocin active substances against different pathogens (Staphylococcus aureus, S. agalactiae ATCC 27956, Streptococcus uberis, coagulase negative Staphylococcus and Listeria monocytogenes Scott A). In all the studies performed some LAB wer able to inhibit the growth of pathogenic strains specific from the original isolation niches. The evaluation of the functional properties of the different LAB strains was performed based for their potential applicability in each tract: the selected vaginal strains were tested by the adhesion capability to epithelial cells and their resistance to the most frequent antibiotic therapies. Together with some other selected digestive strains were assayed for their resistance to the gastrointestinal conditions. Also, some technological properties (freezing dried and storage conditions) were evaluated in strains with specific characteristics. The selected micro organisms could be potentially included in a wide range of veterinary probiotic products to be applied in different ecological bovine mucosa: reproductive and digestive tracts, and mammary gland. They will improve the health animal status and promote the productivity. Keywords: Probiotic, veterinary product, health, metritis, mastitis, calf diarrea.