Enterococcus isolated from poultry intestine for potential probiotic use.

Background and Aim: To develop species-specific probiotics for poultry, it is ideal to obtain these probiotic microorganisms directly from the intestinal tract of broiler and egg-laying chicks in production environments to ensure adaptation to actual conditions. This study aimed to isolate lactic acid bacteria (LAB) from the intestinal tract of broiler and egg-laying chicks to determine their probiotic potential. Materials and Methods: Twenty-five Ross-308 broilers and 25 Isa Brown egg-laying chicks were raised until days 42 and 120, respectively; they were housed in an individual poultry building. Lactic acid bacteria were isolated and identified from the small intestine mucus of broiler and layer chicks and then evaluated based on resistance to acidic pH levels, bile salt concentration, and antagonistic activity against wild strains of Escherichia coli and Salmonella spp. selected strains with probiotic potential were identified by polymerase chain reaction and confirmed by rDNA sequencing. Results: One hundred and fifty Gram-positive isolates were obtained; 28% (42) were catalase and oxidase negative and biochemical identification was made by crystal system: 76.2% (32) Enterococcus spp., 16.6% (7) Lactococcus spp., and 7.2% (3) Streptococcus spp.; and evaluated for hemolysin production; tolerance to low pH and bile salts, and antagonistic potential were carried out. Molecular characterization yielded 56% (24) Enterococcus faecium, and 44% (18) Enterococcus faecalis. About 81% (34) of strains were without vancomycin resistance genes criterion. Conclusion: This study isolated and characterized 36 strains of LAB with probiotic qualities, from the intestines of broiler and egg-laying chicks, selecting E. faecium, Enterococcus avium, and Enterococcus casseliflavus, Lactococcus garviae as promising strains for further in vitro and in vivo research.

Real-time parameter estimation of Zika outbreaks using model averaging.

Early prediction of the final size of any epidemic and in particular for Zika disease outbreaks can be useful for health authorities in order to plan the response to the outbreak. The Richards model is often been used to estimate epidemiological parameters for arboviral diseases based on the reported cumulative cases in single- and multi-wave outbreaks. However, other non-linear models can also fit the data as well. Typically, one follows the so called post selection estimation procedure, i.e., selects the best fitting model out of the set of candidate models and ignores the model uncertainty in both estimation and inference since these procedures are based on a single model. In this paper we focus on the estimation of the final size and the turning point of the epidemic and conduct a real-time prediction for the final size of the outbreak using several non-linear models in which these parameters are estimated via model averaging. The proposed method is applied to Zika outbreak data in four cities from Colombia, during the outbreak ocurred in 2015-2016.

Effect of Moxidectin Treatment at Peripartum on Gastrointestinal Parasite Infections in Ewes Raised under Tropical Andes High Altitude Conditions.

This study tested the impact of moxidectin at peripartum on nematode fecal egg count (FEC) and clinical parameters on ewes in the high altitude tropical Andes of Colombia. FEC and clinical evaluations were performed on 9 occasions in 43 naturally infected ewes before and during gestation and after lambing. Moxidectin (Mox, 200 µg kg(-1)) was applied at late pregnancy (T 1, n = 15) or 48 hours after parturition (T 2, n = 14). 14 untreated ewes served as controls (C). Suckling lambs (n = 58) remained untreated and underwent four clinical and parasitological evaluations until 8 weeks after birth. Mox efficacy equaled 99.3% (T 1) and 96.9% (T 2). Highest mean FEC value reflecting periparturient nematode egg rise (PPER) was recorded in C ewes at 4-6 weeks after lambing. Significant FEC reductions were found in T 1 (94.8%) and T 2 (96.7%) ewes (p < 0.05). All lambs showed a significant and ewes-group independent increase in FEC before weaning (p < 0.05). Clinical parameters (anemia and diarrhea) showed time- and treatment-related differences (p < 0.05). Monitoring of FEC and clinical parameters linked to gastrointestinal parasite infections allowed demonstrating that postpartum or preweaning are two critical periods to nematode infection for sheep raised under tropical Andes high altitude conditions. Use of Mox as anthelmintic treatment prevented PPER.

Effects of crossbreeding on endocrine patterns determined in pregnant beef/dairy cows naturally infected with Neospora caninum.

Neospora caninum is an intracellular coccidian parasite causing abortion worldwide in dairy cattle. Studies have shown that N caninum infection modifies endocrine patterns and that beef cows or cows with a crossbreed pregnancy, especially for a greater maternal-paternal genetic distance, show a reduced risk of abortion when naturally infected compared with pure-breed Holstein Friesian (HF) pregnancies. This study examined the effects of crossbreeding on plasma progesterone (P4), pregnancy-associated glycoprotein (PAG)-1 and -2, and prolactin patterns produced during gestation in N caninum-infected beef/dairy cows. We analyzed 74 pregnancies in nonaborting cows carrying a single fetus established in 26 lactating HF cows bred with Holstein bulls (H-H), 13 HF cows bred with Limousin bulls (H-L), 12 HF cows used as recipients of transferred in vivo-produced frozen-thawed Rubia Gallega (beef breed; RG) embryos (H-RG-ET), and 23 RG suckling cows bred with RG bulls (RG-RG). Of the cows, 29 (39%) were seropositive for N caninum. Blood samples for hormone and placental protein determinations were collected on Days 30, 60, 90, 120, 150, and 180 of gestation. Procedures of repeated measures analysis of variance throughout gestation revealed higher PAG-1 levels in the H-L and H-RG-ET groups compared with H-H and RG-RG. Higher prolactin levels were detected in RG-RG than in the remaining groups. N caninum seropositivity and fetal genotype had a significant effect on PAG-2 concentrations, such that highest levels of PAG-2 occurred in RG-RG seropositive cows and lowest in H-H seropositive cows, whereas Neospora-seropositive cows showed lower P4 concentrations than their seronegative partners. In conclusion, chronic N caninum infection modifies endocrine patterns of PAG-2 and P4 during pregnancy, whereas PAG-1 and prolactin concentrations are affected by breed and fetal genotype, irrespective of Neospora infection status.

Prediction of pregnancy viability in bovine in vitro-produced embryos and recipient plasma with Fourier transform infrared spectroscopy.

We analyzed embryo culture medium (CM) and recipient blood plasma using Fourier transform infrared (FTIR) metabolomics to predict pregnancy outcome. Individually cultured, in vitro-produced (IVP) blastocysts were transferred to recipients as fresh and vitrified-warmed. Spent CM and plasma samples were evaluated using FTIR. The discrimination capability of the classifiers was assessed for accuracy, sensitivity (pregnancy), specificity (nonpregnancy), and area under the receiver operator characteristic curve (AUC). Within all IVP fresh embryos (birth rate=52%), high AUC were obtained at birth, especially with expanded blastocysts (CM: 0.80±0.053; plasma: 0.89±0.034). The AUC of vitrified IVP embryos (birth rate = 31%) were 0.607±0.038 (CM, expanded blastocysts) and 0.672±0.023 (plasma, all stages). Recipient plasma generally predicted pregnancy outcome better than did embryo CM. Embryos and recipients with improved pregnancy viability were identified, which could increase the economic benefit to the breeding industry.

Different humoral mechanisms against Neospora caninum infection in purebreed and crossbreed beef/dairy cattle pregnancies.

The antigen-specific IgG subclass response may be a convenient indicator of the underlying nature of T helper cell regulation. The aim of the present study was to identify possible differences in Neospora caninum-specific total plasma IgG, IgG1 and IgG2 antibody levels in purebreed and crossbreed pregnancies throughout gestation in beef and dairy cattle chronically infected with N. caninum. Comparisons were also made between aborting and non-aborting dams. The population examined comprised 96 pregnant parous cows seropositive for N. caninum. Plasma antibodies were determined on Days 90, 120, 150, 180 and 210 of gestation or until abortion. Of the 96 pregnancies examined, 12 ended in abortion. None of the 14 Holstein-Friesian (HF) cows inseminated with HF semen (HF-HF group) aborted, whereas 6 (11.0%) of the 54 HF cows inseminated with Limousin semen (HF-L group) and 6 (21.4%) of the 28 Rubia Gallega (RG) beef cows inseminated with RG semen (RG-RG group) aborted. In the 84 non-aborting cows, a significant positive effect of gestation day was observed on total IgG, IgG1 and IgG2 antibodies levels (P<0.0001 for the three variables). In RG-RG cows, significantly higher levels of IgG (P=0.003; d.f.=2; F-value=6.41), IgG1 (P<0.001; d.f.=2; F-value=10.55) and IgG2 (P=0.004; d.f.=2; F-value=5.82) antibodies against N. caninum were recorded throughout gestation compared to the other groups, whereas the levels of these antibodies were significantly lower in HF-HF on Days 180 and 210 of gestation. In aborting cows, significantly lower IgG (P=0.001; d.f.=1; F-value=25.21) and IgG2 (P=0.001; d.f.=1; F-value=20.39) antibody levels were observed in the RG-RG cows compared to the HF-L cows, whereas no significant effect on IgG1 antibody levels was detected in the two groups with aborting animals (RG-RG and HF-L). Our findings indicate that humoral mechanisms against N. caninum infection and abortion differ in purebreed pregnancies and crossbreed pregnancies in beef/dairy cattle.

Neospora caninum and coxiella burnetii seropositivity are related to endocrine pattern changes during gestation in lactating dairy cows.

Q fever is a zoonotic infection caused by Coxiella burnetii that is endemic worldwide. Domestic ruminants are a source of infection for humans. Given the suggestion that the bacterium recrudesces during pregnancy in cattle, this study was designed to determine whether C. burnetii infection affects hormonal patterns, such as progesterone, cortisol, pregnancy associated glycoproteins (PAG), and prolactin during gestation in lactating cows. Possible interactions with Neospora caninum were also explored. The study was performed on 58 gestating non-aborting cows. Blood samples for hormone determinations were collected on Days 40, 90, 120, 150, 180, and 210 of gestation. For antibody determinations, blood was collected at day 40 postinsemination and postpartum. By GLM repeated measures analysis of variance, we established the effects of production and reproductive variables as well as Coxiella and Neospora seropositivity related to changes on cortisol, PAG, progesterone, and prolactin levels. Coxiella antibody levels were significantly related to cortisol, PAG, and plasma progesterone concentrations, whereas Neospora seropositivity was linked to plasma progesterone concentrations. The interaction between Coxiella and Neospora seropositivity was correlated with cortisol and plasma progesterone levels, whereas the interaction seropositivity against C. burnetii-plasma cortisol concentration was related to plasma PAG levels. Finally, an effect of lactation number only was observed on plasma prolactin. Our findings suggest that both the N. caninum and C. burnetii infection or the presence of both modify endocrine patterns throughout gestation. Cows seropositive to both, Neospora and Coxiella, showed higher plasma progesterone levels than the remaining animals examined. Seropositivity to C. burnetii was associated with placental damage and diminishing PAG levels throughout the second half of gestation, along with increased plasma cortisol levels on Day 180 of gestation.