Development and storage studies of high density macrocapsules containing Lactobacillus spp. strains as nutritional supplement in young calves.

The aim of this study was to evaluate different production methodologies of probiotic macrocapsules with high bacterial densities destined to lactating calves. Three types of capsules containing Lactobacillus casei DSPV318T and Lactobacillus plantarum DSPV354T were prepared from an overnight culture in whey medium: (1) mixing the culture with calcium alginate and then, reincubating the capsules in whey (RC); (2) concentrating the biomass by centrifugation and mixing the pellet with calcium alginate (CC) at different concentrations with respect to the initial culture (5X and 12.5X); (3) CC with cryoprotectants: whey permeate (Per) and glycerol (Gly). Chitosan coating was evaluated. Capsules were freeze-dried and viability was assessed before freezing, after freeze-drying and every two weeks for 84 days of storage at room temperature, 4°C and -20°C. CC showed higher cell densities than RC. Storage temperature affected viability: greater viability at lower temperature. Moreover, the effect of temperature was influenced by other factors, such as capsule coating, culture neutralization and cryoprotectants. Coating improved viability at room temperature; however no effect was observed at 4°C. Culture neutralization allowed greater survival during storage. Cryoprotectants improved viability during freezing, but they also generated a positive or negative effect depending on storage temperature. The best results were: at refrigeration Gly12.5X exhibited counts above 109CFU/capsule until day 70 and Per12.5X until day 56 of storage and at -20°C Gly12.5X showed counts above 109CFU/capsule until the end of the study (84 days). A 109CFU capsule is the daily dose per calf which would facilitate the administration of this probiotic inoculum to field animals.

Genetic diversity of thermotolerant Campylobacter spp. isolates from different stages of the poultry meat supply chain in Argentina.

The objective of this study was to investigate a clonal relationship among thermotolerant Campylobacter spp. isolates from different stages of the poultry meat supply chain in Argentina. A total of 128 thermotolerant Campylobacter spp. (89 C. jejuni and 39 C. coli) isolates from six poultry meat chains were examined. These isolates were from: a) hens from breeder flocks, b) chickens on the farm (at ages 1 wk and 5 wk), c) chicken carcasses in the slaughterhouse, and d) chicken carcasses in the retail market. Chickens sampled along each food chain were from the same batch. Campylobacter spp. isolates were analyzed using pulsed-field gel electrophoresis to compare different profiles according to the source. Clustering of C. jejuni isolates resulted in 17 profiles, with four predominant genotypes and many small profiles with just a few isolates or unique patterns, showing a very high degree of heterogeneity among the C. jejuni isolates. Some clusters included isolates from different stages within the same chain, which would indicate a spread of strains along the same poultry meat chain. Moreover, twenty-two strains of C. coli clustered in seven groups and the remaining 17 isolates exhibited unique profiles. Evidence for transmission of thermotolerant Campylobacter spp. through the food chain and cross contamination in the slaughterhouses were obtained. This collective evidence should be considered as the scientific basis to implement risk management measures to protect the public health.

[Campylobacter jejuni O:19 serotype in Argentine poultry meat supply chain]. / Presencia de serotipos de Campylobacter jejuni O:19 en la cadena avícola Argentina.

Thermotolerant species of Campylobacter have been focus of attention in the last years because they are the major agent causing zoonotic foodborne diseases. In addition, Campylobacter jejuni O:19 serotype was associated with Guillain Barré syndrome. The aim of this study was to determine the proportion of C. jejuni O:19 serotype isolated at different stages of three poultry meat supply chain in Santa Fe, Argentina. The analysis showed that 18% of isolated C. jejuni belong to serotype O:19. It was also determined that the presence of these strains is given in almost all production stages. These results reflect a significant risk to public health of consumers. Epidemiological studies of Campylobacter should be considered to establish a risk manager policy.

Probióticos en pollos parrilleros: una estrategia para los modelos productivos intensivos / Probiotics in broilers´ rearing: a strategy for intensive production models

La industria avícola se ha convertido en una importante actividad económica en Argentina. En nuestro país, el consumo de carne aviar ha experimentado un aumento sustancial en los últimos años debido al incremento y a la diversificación de la oferta de productos. Gracias a los avances tecnológicos experimentados en los últimos años (mejoras genéticas, automatizaciones, planes sanitarios, etc.), el pollo parrillero alcanza en solo 50 días el peso requerido para la faena, con 2,7kg y una conversión alimentaria de alrededor de 1,6kg de alimento/kg de carne. Para satisfacer la demanda actual y continuar en la búsqueda de mercados internacionales, los pollos parrilleros son sometidos a sistemas de crianza intensivos en confinamiento. En esos sistemas, los pollos parrilleros están expuestos diariamente a diversos factores de estrés. La suplementación con antibióticos fue ampliamente utilizada en las últimas décadas para estabilizar la microbiota intestinal, mejorar los parámetros productivos y prevenir las enfermedades aviares. Sin embargo, la utilidad de esta estrategia ha sido cuestionada debido a la aparición y propagación de bacterias resistentes a los antibióticos en la carne. Por lo tanto, hay un renovado interés en la búsqueda de alternativas viables a los antibióticos; es así que la suplementación de las dietas con probióticos se plantea como una opción interesante. Esta revisión proporciona un resumen actual sobre el empleo de probióticos en pollos parrilleros, haciendo énfasis en el papel de estos como una terapia alternativa que podría reemplazar a los antibióticos utilizados en producción y sanidad animal

The broiler industry has become an important economic activity in Argentina. Global production of broiler meat has been growing in Argentina faster than for any other meats, possibly due to declining poultry prices and increasing incomes. Modern rearing systems can produce broilers ready to slaughter in 50 days, with the required 2.7kg of weight and a feed conversion of about 1.6kg feed/kg of meat. Nevertheless, broilers raised under these intensive conditions are exposed to various stressors every day. For many years, feed supplementation with antibiotics was widely used to stabilize the gut flora, improve general parameters and prevent avian diseases. However, the utility of antibiotics has been questioned because of the emergence and spread of antibiotic-resistant bacteria in meat. Therefore, there is a renewed interest in finding viable alternatives to antibiotics. One potential method is the supplementation of broiler diets with probiotics. This review provides an updated summary of the use of probiotics to improve sanitary conditions and enhance performance in broilers, demonstrating the role of probiotics as a reliable option to replace antimicrobial growth promoters

[Probiotics in broilers' rearing: A strategy for intensive production models]. / Probióticos en pollos parrilleros: una estrategia para los modelos productivos intensivos.

The broiler industry has become an important economic activity in Argentina. Global production of broiler meat has been growing in Argentina faster than for any other meats, possibly due to declining poultry prices and increasing incomes. Modern rearing systems can produce broilers ready to slaughter in 50 days, with the required 2.7kg of weight and a feed conversion of about 1.6kg feed/kg of meat. Nevertheless, broilers raised under these intensive conditions are exposed to various stressors every day. For many years, feed supplementation with antibiotics was widely used to stabilize the gut flora, improve general parameters and prevent avian diseases. However, the utility of antibiotics has been questioned because of the emergence and spread of antibiotic-resistant bacteria in meat. Therefore, there is a renewed interest in finding viable alternatives to antibiotics. One potential method is the supplementation of broiler diets with probiotics. This review provides an updated summary of the use of probiotics to improve sanitary conditions and enhance performance in broilers, demonstrating the role of probiotics as a reliable option to replace antimicrobial growth promoters.

In vitro and in vivo screening of native lactic acid bacteria toward their selection as a probiotic in broiler chickens.

Among 360 isolates from the gastrointestinal tract (GIT) of broilers, eleven isolates which showed in vitro probiotic properties were identified and selected for further tests. After the in vitro screening, three strains were chosen for the in vivo study of persistence of fresh cultures and then one strain was selected for the in vivo study of persistence of lyophilized culture. Lyophilized Lactobacillus salivarius DSPV 001P was capable of persisting in broilers during a complete rearing, even 28 days following cessation of administration. L. salivarius DSPV 001P administered to broilers and recovered from GIT was compared by pulsed-field gel electrophoresis (PFGE) to ensure that the same genotype was persistently identified. A combination of in vitro and in vivo screening of native lactic acid bacteria (LAB) described in this study may offer a method for selecting the most suitable strain for potential application as a broiler probiotic supplement.