One-step synthesis of luminescent YVO4:Eu3+/γ-Al2O3 nanocomposites by spray pyrolysis.

Spray pyrolysis (SP) easily affords nano or sub-micro phosphor particles even on an industrial scale. However, control of the coordination environment around the emitting ion is inefficient, and the final solid matrix will dictate the symmetry of the emitter. Moreover, the fast heat treatment typical of SP usually results in heterogeneous symmetry sites. This paper aimed to obtain inorganic matrices incorporated with phosphors by SP while keeping the symmetry of the emitting ion unchanged along the pyrolysis process. Nanoparticles consisting of Eu3+-doped YVO4 phosphors with average diameter of 15 nm were prepared by the co-precipitation method and were subsequently incorporated into the alumina matrix by SP, to yield YVO4:Eu3+/γ-Al2O3 composite particles with mean size of 600 nm. X-ray powder diffraction confirmed that the vanadate particles were incorporated into the alumina matrix, and that the γ-Al2O3 phase emerged. The band due to the [Formula: see text] â†’ Eu3+ transition intensified as a consequence of the incorporation of YVO4:Eu3+ into alumina-the suppression effects caused by the surface properties of the YVO4:Eu3+ phosphor nanoparticles diminished, while the structure of Eu3+ remained unchanged in the matrix.

Modulation of Broiler Intestinal Changes Induced by Clostridium perfringens and Deoxynivalenol through Probiotic, Paraprobiotic, and Postbiotic Supplementation.

Deoxynivalenol (DON) is a predisposing factor for necrotic enteritis. This study aimed to investigate the effects of a DON and Clostridium perfringens (CP) challenge on the intestinal morphology, morphometry, oxidative stress, and immune response of broilers. Additionally, we evaluated the potential of a Lactobacillus spp. mixture as an approach to mitigate the damage induced by the challenge. One-day-old broiler chickens (n = 252) were divided into seven treatment groups: Control, DON, CP, CP + DON, VL (DON + CP + viable Lactobacillus spp. mixture), HIL (DON + CP + heat-inactivated Lactobacillus spp. mixture), and LCS (DON + CP + Lactobacillus spp. mixture culture supernatant). Macroscopic evaluation of the intestines revealed that the CP + DON group exhibited the highest lesion score, while the VL and HIL groups showed the lowest scores. Microscopically, all Lactobacillus spp. treatments mitigated the morphological changes induced by the challenge. DON increased levels of reactive oxygen species (ROS) in the jejunum, and CP increased ROS levels in the jejunum and ileum. Notably, the Lactobacillus spp. treatments did not improve the antioxidant defense against CP-induced oxidative stress. In summary, a Lactobacillus spp. mixture, whether used as a probiotic, paraprobiotic, or postbiotic, exerted a partially protective effect in mitigating most of the intestinal damage induced by DON and CP challenges.

Resistance and Virulence Surveillance in Escherichia coli Isolated from Commercial Meat Samples: A One Health Approach.

Escherichia coli is a key indicator of food hygiene, and its monitoring in meat samples points to the potential presence of antimicrobial-resistant strains capable of causing infections in humans, encompassing resistance profiles categorized as serious threats by the Centers for Disease Control and Prevention (CDC), such as Extended-Spectrum Beta-Lactamase (ESBL)-a problem with consequences for animal, human, and environmental health. The objective of the present work was to isolate and characterize ESBL-producing E. coli strains from poultry, pork, and beef meat samples, with a characterization of their virulence and antimicrobial resistance profiles. A total of 450 meat samples (150 chicken, 150 beef, and 150 pork) were obtained from supermarkets and subsequently cultured in medium supplemented with cefotaxime. The isolated colonies were characterized biochemically, followed by antibiogram testing using the disk diffusion technique. Further classification involved biofilm formation and the presence of antimicrobial resistance genes (blaCTX-M, AmpC-type, mcr-1, and fosA3), and virulence genes (eaeA, st, bfpA, lt, stx1, stx2, aggR, iss, ompT, hlyF, iutA, iroN, fyuA, cvaC, and hylA). Statistical analysis was performed via the likelihood-ratio test. In total, 168 strains were obtained, with 73% originating from chicken, 22% from pork, and 17% from beef samples. Notably, strains exhibited greater resistance to tetracycline (51%), ciprofloxacin (46%), and fosfomycin (38%), apart from ß-lactams. The detection of antimicrobial resistance in food-isolated strains is noteworthy, underscoring the significance of antimicrobial resistance as a global concern. More than 90% of the strains were biofilm producers, and strains carrying many ExPEC genes were more likely to be biofilm formers (OR 2.42), which increases the problem since the microorganisms have a greater chance of environment persistence and genetic exchange. Regarding molecular characterization, bovine samples showed a higher prevalence of blaCTX-M-1 (OR 6.52), while chicken strains were more likely to carry the fosA3 gene (OR 2.43, CI 1.17-5.05) and presented between 6 to 8 ExPEC genes (OR 2.5, CI 1.33-5.01) compared to other meat samples. Concerning diarrheagenic E. coli genes, two strains harbored eae. It is important to highlight these strains, as they exhibited both biofilm-forming capacities and multidrug resistance (MDR), potentially enabling colonization in diverse environments and causing infections. In conclusion, this study underscores the presence of ß-lactamase-producing E. coli strains, mainly in poultry samples, compared to beef and pork samples. Furthermore, all meat sample strains exhibited many virulence-associated extraintestinal genes, with some strains harboring diarrheagenic E. coli (DEC) genes.

Evaluation of Predisposing Factors of Necrotic Enteritis in Experimentally Challenged Broiler Chickens.

Clostridium perfringens is the etiological agent of NE, a disease that greatly affects the poultry industry. Experiments on the induction of NE are difficult to carry out, as it is a multifactorial disease, and thus different predisposing factors have been used. This study evaluated the effect of the Gumboro disease vaccine virus vaccine (IBDV-vac) associated or not with infection by Eimeria spp. in broilers, as a predisposing factor for NE. Broilers (n = 99) were divided into groups (11) challenged with IBDV-vac, Eimeria spp. CP type G (CP13, CP14 and CP03) or both. The macroscopic evaluation revealed that the highest average (3.45) of injury occurred for the CP13 + IBDV-vac group. The microscopic analysis showed that Eimeria spp. increased the population of intraepithelial lymphocytes and reduced the villus/crypt ratio in duodenum and jejunum when associated with CP13 or CP14. There was a synergistic effect between the CP strain used and the predisposing factors; nevertheless, it was not clear which was the most effective predisposing factor to potentiate the lesions, suggesting that the association of the strain with the factors should first be evaluated for each experimental protocol.

High-Frequency Detection of fosA3 and bla CTX-M-55 Genes in Escherichia coli From Longitudinal Monitoring in Broiler Chicken Farms.

Considering the worrying emergence of multidrug resistance, including in animal husbandry and especially in food-producing animals, the need to detect antimicrobial resistance strains in poultry environments is relevant, mainly considering a One Health approach. Thus, this study aimed to conduct longitudinal monitoring of antimicrobial resistance in broiler chicken farms, with an emphasis on evaluating the frequency of resistance to fosfomycin and ß-lactams. Escherichia coli was isolated from broiler chicken farms (cloacal swabs, meconium, poultry feed, water, poultry litter, and Alphitobius diaperinus) in northern Paraná from 2019 to 2020 during three periods: the first period (1st days of life), the second period (20th to 25th days of life), and third period (40th to 42nd days of life). Antibiogram tests and the detection of phenotypic extended-spectrum ß-lactamase (ESBL) were performed, and they were confirmed by seaching for genes from the bla CTX-M group. The other resistance genes searched were mcr-1 and fosA3. Some ESBL bla CTX-M-1 group strains were selected for ESBL identification by sequencing and enterobacterial repetitive intergenic consensus-polymerase chain reaction analysis. To determine the transferability of the bla CTX-M-1- and fosA3-carrying plasmids, strains were subjected to conjugation experiments. A total of 507 E. coli were analyzed: 360 from cloacal swabs, 24 from meconium samples, 3 from poultry feed samples, 18 from water samples, 69 from poultry litter samples, and 33 from A. diaperinus samples. Among the strain isolate, 80% (406/507) were multidrug-resistant (MDR), and 51% (260/507) were ESBL-positive, with the bla CTX-M-1 group being the most frequent. For the fosA3 gene, 68% (344/507) of the strains isolated were positive, deserves to be highlighted E. coli isolated from day-old chickens (OR 6.34, CI 2.34-17.17), when compared with strains isolated from other origins (poultry litter, A. diaperinus, water, and poultry feed). This work alerts us to the high frequency of the fosA3 gene correlated with the CTX-M-1 group (OR 3.57, CI 95% 2.7-4.72, p < 0.05), especially the bla CTX-M-55 gene, in broiler chickens. This profile was observed mainly in day-old chicken, with a high percentage of E. coli that were MDR. The findings emphasize the importance of conducting longitudinal monitoring to detect the primary risk points during poultry production.

Lactobacillus spp. reduces morphological changes and oxidative stress induced by deoxynivalenol on the intestine and liver of broilers.

The mycotoxin deoxynivalenol (DON) contaminates animal feed worldwide, frequently resulting in poor performance and economic losses. Data concerning the effects on poultry health or focusing on intestinal toxicity or the response to oxidative stress are scarce. Also, there is a need for strategies to mitigate the negative effects of DON. This study aimed to investigate the effects of Lactobacillus spp. treatments on the intestine, liver and kidney of poultry fed a DON-contaminated diet. To achieve this aim, histological, morphometrical and histochemical assays were performed. The oxidative stress response was also analyzed by the tests: reduced glutathione, ferric reducing ability, reducing of 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid), nitro blue tetrazolium detection of superoxide anion, and thiobarbituric acid reactive substances. One-day-old broilers chickens (n 50) were submitted to the following treatments: control, DON (19.3 mg kg-1), viable Lactobacillus spp. + DON (VL + DON), heat-inactivated Lactobacillus spp. + DON (HIL + DON), Lactobacillus spp. culture supernatant + DON (LCS + DON). The animals received the contaminated diet for seven days. DON increased the intestinal and liver lesion score, while the Lactobacillus spp. treatments (LT) remained like the control. DON reduced the villi height and increased the crypt depths. The LT showed crypt depths similar to control, and higher villi: crypt ratio in duodenum and jejunum. In the ileum, the LT reduced the goblet cell count in relation to DON group. DON increased the number of intraepithelial lymphocytes (IEL) in jejunum and ileum, while the VL + DON treatment induced a significant decrease in IEL in comparison to DON. DON-diet induced an oxidative stress response in the intestine and liver, and also reduced the antioxidant capacity in these tissues, while LT treatments remained mostly similar to control. DON induced no change in redox balance in the kidney. The LT improved the intestinal health after DON acute exposure, reducing the oxidative stress damage mainly on jejunum and liver.

Proteus mirabilis causing cellulitis in broiler chickens.

Given the need to understand the virulence profile of Proteus mirabilis isolates from cellulitis in broiler chickens and their ability to cause lesions, the present study aimed to characterize genotypically and phenotypically the virulence profiles of two strains of P. mirabilis isolated from cellulitis in broilers, as well as to evaluate their ability to experimentally reproduce the lesions in vivo. The strain with the highest virulence potential (LBUEL-A33) possessed mrpA, pmfA, ucaA, atfA (fimbriae), zapA, ptA (proteases), hpmA (hemolysin), and ireA (siderophore) genes, formed a very strong biofilm, and expressed the pattern of aggregative adhesion and cytotoxicity in Vero cells. The strain with the lowest virulence potential (LBUEL-A34) did not present the pmfA and ucaA genes, but expressed the pattern of aggregative adhesion, formed a strong biofilm, and did not show cytotoxicity. Both strains developed cellulitis in an animal model within 24 h post-inoculation (PI), and the degree of lesions was not significantly altered up to 120 h PI. The LBUEL-A33 strain was also inoculated in combination with an avian pathogenic Escherichia coli (APEC 046), and the lesions showed no significant changes from the individual inoculation of these two strains. Histological analysis showed that the LBUEL-A33 strain developed characteristic cellulitis lesions. Thus, both strains of P. mirabilis isolated in our study have several virulence factors and the ability to develop cellulitis in broilers.

Tryptophan Attenuates the Effects of OTA on Intestinal Morphology and Local IgA/IgY Production in Broiler Chicks.

Ochratoxin A (OTA) is a mycotoxin produced by species of Penicillium and Aspergillus that can contaminate products of plant origin that are used as animal feed. Through oral exposure, this mycotoxin primarily affects the chicken gastrointestinal system. The present study evaluated the intestinal toxic effects of OTA and the introduction of L-tryptophan to alleviate these effects in chickens. One-day-old chicks were exposed to a single OTA dose (1.4 mg/kg body weight-b.w.) and treated with or without four daily doses of L-tryptophan (100 mg/kg b.w.). Duodenal villus height/crypt depth, fecal immunoglobulin A/immunoglobulin Y (IgA/IgY) levels, and duodenal positive immunoglobulin A cells (IgA+) were evaluated by histology, ELISA, and immunohistochemistry, respectively, on the 14th day. There were significant changes in the duodenal villus height, crypt depth, and levels of fecal IgA/IgY and duodenal IgA+ cells (p < 0.05) in groups exposed to OTA. On the other hand, groups exposed to OTA and treated with L-tryptophan showed similar levels of villus height, IgA/IgY levels, and duodenal IgA+ cells to those of the control group (p > 0.05). In conclusion, exposure to a single dose of OTA orally induces changes in intestinal morphology, levels of IgA/IgY antibodies, and IgA+ cells. Thus, treatment with L-tryptophan may be a valid alternative means to reduce the harmful effects of OTA on the intestinal mucosa, which requires further study.