Study of coinfection with local strains of infectious bursal disease virus and infectious bronchitis virus in specific pathogen-free chickens.

Immunosuppressive diseases cause great losses in the poultry industry, increasing the susceptibility to infections by other pathogens and promoting a suboptimal response to vaccination. Among them, infectious bursal disease virus (IBDV) arises as one of the most important around the world. IBDV infects immature B lymphocytes, affecting the immune status of birds and facilitating infections by other pathogens such as avian infectious bronchitis virus (IBV). Although it has been reported that the interaction between these viruses increases IBV clinical signs, there are no actual studies about the interaction between regional circulating isolates that validate this statement. In this context, the objective of our work was to evaluate the effect of the interaction between local isolates of IBDV (belonging to genogroup 4) and IBV (lineage GI-16) in chickens. Thus, specific pathogen-free chickens were orally inoculated with IBDV genogroup (G) 4 or with PBS at 5 d of age. At 14-days postinoculation (dpi) the animals were intratracheally inoculated with a GI-16 IBV or with PBS. At multiple time points, groups of birds were euthanized and different parameters such as histological damage, viral load, lymphocyte populations and specific antibodies were evaluated. The success of IBDV infection was confirmed by the severity of bursal atrophy, viral detection, and presence of anti-IBDV antibodies. In IBV-infected animals, the presence of viral genome was detected in both kidney and bursa. The coinfected animals showed higher degree of lymphocyte infiltration in kidney, higher rate of animals with IBV viral genome in bursa at 28 dpi, and a clear decrease in antibody response against IBV at 28, 35, and 40 dpi. The results indicate that the infection with the local isolate of IBDV affects the immune status of the chickens, causing major severe damage, in response to IBV infection, which could consequently severely affect the local poultry industry.

Polymicrobial oral conventionalization model in mice.

The aim of this study is to describe a new polymicrobial oral conventionalization protocol in mice. Oral biofilm samples were collected from wild C57 BL/6 mice (WG), which had not been previously submitted to any experimental procedure. The contents of these samples were used for inoculation in the oral cavity of specific pathogen free (SPF) animals. This inoculation was repeated 3 times. Qualitative cytological analyses were performed in the days 0, 16 and 80 of the experimental protocol, to check the presence or absence of microorganisms, their morphology and staining characteristics on the oral cavity of the animals. At the end of this study, was observed a combination of oral bacterial microbiota of SPF animals and wild animals in the conventionalized group (CONV). Samples collected from CONV mice on day 16, a period in which these animals had been previously inoculated 3 times with wild mouse microbiota, showed a greater amount of Gram-positive cocci, as seen in SPF animals. In addition, Gram-negative cocci were present, although in a much smaller proportion than previously seen in wild mice. On the 80th experimental day, CONV animals showed a predominance of Gram-positive cocci and bacilli. Filamentous bacteria were also seen in this group. The conventionalization of SPF animals using the technique with inoculum from the resident microbiota of wild mice proved to be an effective, low-cost and easily reproducible technique. The conventionalized animals showed the colonization of a microbiota similar to wild animals up to 80 days of experiment.

Blockade of nociceptin/orphanin FQ signaling facilitates an active copying strategy due to acute and repeated stressful stimuli in mice.

The role of stress in the etiology of depression has been largely reported. In this line, exogenous glucocorticoids are employed to mimic the influence of stress on the development of depression. The N/OFQ-NOP receptor system has been implicated in the modulation of stress and emotional behaviors. In fact, the blockade of NOP receptors induces antidepressant effects and increases resilience to acute stress. This study investigated the effects of the NOP receptor blockade on dexamethasone-treated mice exposed to acute and prolonged swimming stress. Swiss and NOP(+/+) and NOP(-/-) mice were treated with dexamethasone, and the protective effects of the NOP antagonist SB-612111 (10 mg/kg, ip) or imipramine (20 mg/kg, ip) were investigated in three swimming sessions. The re-exposure to swim stress increased immobility time in Swiss and NOP(+/+), but not in NOP(-/-) mice. Acute and repeated dexamethasone administration induced a further increase in the immobility time, and facilitated body weight loss in Swiss mice. Single administration of SB-612111, but not imipramine, prevented swimming stress- and dexamethasone-induced increase in the immobility time. Repeated administrations of SB-612111 prevented the deleterious effects of 5 days of dexamethasone treatment. Imipramine also partially prevented the effects of repeated glucocorticoid administration on the immobility time, but did not affect the body weight loss. NOP(-/-) mice were more resistant than NOP(+/+) mice to inescapable swimming stress, but not dexamethasone-induced increase in the immobility time and body weight loss. In conclusion, the blockade of the NOP receptor facilitates an active stress copying response and attenuates body weight loss due to repeated stress.

Isolation and Probiotic Potential of Lactobacillus Salivarius and Pediococcus Pentosaceus in Specific Pathogen Free Chickens

This study was conducted to isolate Lactobacillus salivarius and Pediococcus pentosaceus strains from cecal content and investigate their probiotic potential in specific pathogen free (SPF) chickens. L. salivarius and P. pentosaceus strains were isolated from the cecal content of SPF chickens and identified by 16s rDNA sequence analysis by BLAST analysis at the National Center for Biotechnology Information and phylogenetic analysis using DNAStar software. In an in vivo experiment, 180 7-day-old SPF chickens were randomly assigned into three groups. Group 1 served as a control that was fed a basal diet without probiotic supplementation, and groups 2 and 3 were fed the basal diets supplemented with L. salivarius and P. pentosaceus at 2×108 CFU/g, respectively. Body weight (BW), average daily gain (ADG), feed conversion ratio (FCR), dressing percentage (DP), and the apparent digestibility of crude protein (AD-CP) were calculated. We also determined meat color, fat content, shear force, water content and pH value of breast and thigh muscles; ammonia, urea nitrogen and uric acid content in plasma; fecal ammonia emission level and pH value; and Lactobacillus and Escherichia coli in ceca. Compared with the control group, L. salivarius and P. pentosaceus supplementation significantly increased BW, ADG, DP, AD-CP, fat content of meat, and the number of Lactobacillus in ceca (p 0.05), and decreased FCR, plasma ammonia content, fecal ammonia emission, and pH value and the number of E. coli in ceca (p 0.05). In the in vitro experiment, L. salivarius and P. pentosaceus treatments significantly decreased the ammonia content in medium compared with the control group without probiotic treatment (p 0.05). These results suggest that P. pentosaceus and L. salivarius strains show promising probiotic properties for improving growth, meat quality and microenvironment in chickens and decreasing ammonia content in the medium.

Isolation and Probiotic Potential of Lactobacillus Salivarius and Pediococcus Pentosaceus in Specific Pathogen Free Chickens

This study was conducted to isolate Lactobacillus salivarius and Pediococcus pentosaceus strains from cecal content and investigate their probiotic potential in specific pathogen free (SPF) chickens. L. salivarius and P. pentosaceus strains were isolated from the cecal content of SPF chickens and identified by 16s rDNA sequence analysis by BLAST analysis at the National Center for Biotechnology Information and phylogenetic analysis using DNAStar software. In an in vivo experiment, 180 7-day-old SPF chickens were randomly assigned into three groups. Group 1 served as a control that was fed a basal diet without probiotic supplementation, and groups 2 and 3 were fed the basal diets supplemented with L. salivarius and P. pentosaceus at 2×108 CFU/g, respectively. Body weight (BW), average daily gain (ADG), feed conversion ratio (FCR), dressing percentage (DP), and the apparent digestibility of crude protein (AD-CP) were calculated. We also determined meat color, fat content, shear force, water content and pH value of breast and thigh muscles; ammonia, urea nitrogen and uric acid content in plasma; fecal ammonia emission level and pH value; and Lactobacillus and Escherichia coli in ceca. Compared with the control group, L. salivarius and P. pentosaceus supplementation significantly increased BW, ADG, DP, AD-CP, fat content of meat, and the number of Lactobacillus in ceca (p 0.05), and decreased FCR, plasma ammonia content, fecal ammonia emission, and pH value and the number of E. coli in ceca (p 0.05). In the in vitro experiment, L. salivarius and P. pentosaceus treatments significantly decreased the ammonia content in medium compared with the control group without probiotic treatment (p 0.05). These results suggest that P. pentosaceus and L. salivarius strains show promising probiotic properties for improving growth, meat quality and microenvironment in chickens and decreasing ammonia content in the medium.(AU)

Primera incursión en la obtención de curieles libre de patógenos específicos en Cuba / First foray into the production of specific pathogen-free guinea pigs in Cuba

Resultados confiables y económicos solo son obtenidos cuando los animales de experimentación son aislados de factores ambientales y biológicos, implantándose en el biomodelo una microbiota normal, lejos de la presencia de microorganismos patógenos. El objetivo de la investigación fue obtener curieles libre de patógenos específicos por cesárea aséptica, mantenidos en aisladores y alimentados con dietas estériles. Se realizaron 26 histerectomías. Los animales fueron alimentados con una fórmula modificada (L-477) en forma de papilla hasta los 21 días y permanentemente después la C-484 sólida y granulada, esterilizadas a 121oC/20 minutos o a 1,5Mrad. Además fueron suplementados con vitamina C y B1. El forraje o heno fue consumido a partir de la primera generación. La microbiota gastrointestinal se administró por vía oral en 0,5 ml de una dilución de 10-6/g de contenido de la porción final del íleon, ciego y principio del colon de curieles, a las 24 y 48 horas del nacimiento. Se utilizó para el monitoreo microbiológico caldo Tioglicolato, caldo Triptona Soya y caldo Saboraud incubados aeróbicamente a temperatura de 55, 37 y 25oC respectivamente. Se obtuvieron 51 neonatos. La mortalidad más alta se registró entre los primeros 10 días de edad (58,8%). Se lograron 12 animales (3 machos y 9 hembras), 6 de las hembras se reprodujeron aproximadamente a los 9 meses de edad, lográndose 11 crías por parto normal. La metodología aplicada permitió obtener curieles libres de Salmonella sp, Pasteurella sp, Streptococcus del tipo A y C, Bordetella bronchiseptica, Toxoplasma gondii, Virus Sendai y parásitos internos y externos.

Confidence and economics results are only obtained when the animals are isolated of the environmental and biological factors, that could interfere the course of from investigation and when is being established in them, a normal microflora balanced far from the presence of pathogen microorganisms. They were accomplished 26 histerectomies. The animals were fed with a modified formula of L-477 in the form of porridge until 21 days of age and permanently after with the C-484 solid and granulated, sterilized at 121oC/20 minutes or 1,5Mrad. The forage or hay was consumed by the first generation since the 6 months of age. The gastrointestinal flora was administered by oral route with 0,5 ml of a dilution of 10-6/g of the contents of the ileum final portion, cecum and first part of the colon of conventionalized Dunkin Hartley guinea pigs, at 24 and 48 hours born. It was used for microbiological bacteria monitoring Thioglycolate broth, Tryptic Soy broth and Sabouraud broth incubated aerobically at temperatures of 55, 37 and 25oC respectively. There were obtained 51 newborns. The highest mortality was registered during the first 10 days of age (58,8%). There were archieved 12 animals: 9 female and 3 males. 6 of the female were reproduced approximately at 9 months of age and were archieved 11 normal delivery sucklings. There were obtained guinea pigs free of the followings specific pathogens: Salmonella sp., Pasteurella sp., Streptococcus of the group A y C. Bordetella bronchiseptica, Toxoplasma gondii, Sendai Virus, beside internal and external parasites.