Search

This study describes early immunological mechanisms that underlie resistance to Teladorsagia circumcincta infection in adult Churra sheep. After a first experimental infection, 6 animals were classified as resistant (RG) and 6 as susceptible (SG) to T. circumcincta infection based on their cumulative faecal egg count (cFEC) at the end of the infection. RG showed higher IgA levels against somatic antigen of T. circumcincta fourth-larvae stage (L4) in serum at day 3 post-infection (pi) (p < 0.05) and close to significance at day 21 pi (p = 0.06). Moreover, a strong negative correlation between cFEC and specific IgA was only significant in RG at day 3 pi (r = − 0.870; p < 0.05), but absent in SG. At the end of this infection, sheep were treated with moxidectin and infected again 3 weeks later to be slaughtered at day 7 pi. At necropsy, the specific IgA levels in gastric mucosa were similar between groups; the absence differences at day 7 pi could be due to a previous increase in the IgA response, probably around day 3 pi, as described during the first infection. L4 burden, 68% lower in RG than in SG, was influenced by the specific IgA in gastric mucus and the number of γδ T cells. RG group showed a positive correlation between γδ T cells and eosinophils (r = 0.900; p = 0.037); however, this correlation was not found in SG. These results show that these two phenotypes show different early immune response pattern to T. circumcincta infection in Churra sheep. [ABSTRACT FROM AUTHOR]

Abstract: Canaria Hair Breed (CHB) sheep are more resistant than Canaria sheep (CS) to experimental Haemonchus contortus infection. Protective responses appear effective against the adult stage of the parasite, not as commonly reported in other breeds against the larval stages. In this study we have quantified several abomasal immune cells and correlated these with parasitological variables for each breed. A significant negative correlation between CD4+ T cell numbers and worm burden or length at 28 dpi was seen only in CS sheep. Significant negative correlations for both abomasal eosinophils and γδ/WC1+ T cells, and fecundity of the adult worms were observed only in the resistant CHB sheep breed. Tissue eosinophils and γδ/WC1+ T cells were positively correlated in CHB sheep. We suggest that the two sheep breeds have disparate immune responses following infection with the parasite and that γδ+ T cells in association with eosinophils may play a hitherto unrecognised role in modulating fecundity in H. contortus adult female parasites. [Copyright &y& Elsevier]

Abstract: This study compares the susceptibility to Haemonchus contortus infection in two breeds of sheep endemic to the Canary Islands, the Canaria Hair Breed sheep and the Canaria sheep. Sheep were experimentally infected with 20,000 larvae of H. contortus and animals killed on days 7 and 28 post-infection. No difference between sheep breeds were detected in immature worm counts at days 7 or 28 post-infection. However, in comparison to the Canaria sheep breed, the Canaria Hair Breed sheep showed lower mean faecal egg counts, lower adult worm counts, lower number of eggs in utero and female worm stunting. Overall, these data suggest that the Canaria Hair Breed sheep has a greater resistance to H. contortus infection than Canaria sheep, and that this resistance may act at the level of the adult parasite. [Copyright &y& Elsevier]

A methodology for the conceptual design of concentration circuits is presented. The methodology considers three decision levels: level I – the definition and analysis of the problem, level II – the synthesis and screening of alternatives, and level III – the final design. Level I allows setting up the problem and defining the design goals. In level II circuit alternatives are generated and evaluated using a group contribution method. Also, level II is complemented by a database that helps to select the most suitable circuit. In level III the design of each process stage is performed for the alternatives identified in level II. This final design is performed using local/global sensitivity analysis and reverse simulation. The method is illustrated with examples that demonstrate that the method is suitable for these types of problems. [ABSTRACT FROM AUTHOR]

Background: Intravascular venous (VUC) or arterial (AUC) umbilical catheter placement is the most frequent invasive procedure in the neonatal intensive care unit (NICU). Either Wright's or Shukla's formula is used to introduce the catheters. However, Shukla's formula is associated with incorrect insertion, especially for newborns < 1500 g. This study aimed to determine by chest X-ray if Wright's formula is better than Shukla's formula for the correct placement of umbilical catheters in newborns ≤ 1500 g. Methods: We included patients admitted to the NICU of a secondary-level hospital between 2021-2022 who received VUC or AUC through the Wright or Shukla formulas. Results: A total of 129 newborns were included: 78 with VUC and 51 with AUC. In VUC, 50% with Wright and 36.8% with Shukla formulas had the correct location, (p = 0.24). In AUC, 56.6 % with Wright and 52.4% with Shukla formulas were placed correctly placed, (p = 0.76). VUC with weight < 1000 g were correctly placed in 36.4% with Wright and 33.3% with Shukla formulas (p = 0.58). VUC in newborns > 1000 g were correctly placed in 66.6% with Wright and 38.4% with Shukla formulas (p = 0.065). AUC in newborns < 1000 g were correctly placed in 45% using Wright and 42.9% Shukla formulas (p = 0.63). AUC in newborns > 1000 g were correctly placed in 80% using Wright and 57.1% Shukla formulas (p = 0.23). Conclusions: We found 13% more correctly placed VUC using Wright's formula. Moreover, Wright's formula was 29% above Shukla's VUC placement in neonates > 1000 g, although there was no significant difference due to the sample size. [ABSTRACT FROM AUTHOR]

The increasing resistance to anthelmintics has necessitated the exploration of alternative control strategies of gastrointestinal nematode (GIN) infections. A sustainable option is genetic selection based on differences in susceptibility to GIN infection between and within breeds of sheep. Here, three-month-old Canaria Hair breed (GIN-resistant) and Canaria Sheep breed (GIN-susceptible) showed no significant between-breed differences after trickle infection with Teladorsagia circumcincta, whereas considerable individual variability was found in both breeds. Next, data from lambs of both breeds were used to explore the relationships between parasitological variables and T. circumcincta-specific IgA levels, local immune cell populations, and abomasal lymph node gene expression to understand the possible mechanisms underlying resistance. Mucosal IgA levels as well as numbers of globular leukocytes and MHC-II+ cells were associated with protection. Analysis of lymph node gene expression revealed the associations between lower parasite numbers and cumulative fecal egg counts and several immune pathways, such as leukocyte cell adhesion, activation and differentiation of T cells, in particular CD4+ and IL-4 production. The data obtained here may inform on the relationship between phenotypic resistance variability and protective responses at the humoral, cellular, and transcriptomic levels, thus contributing to identifying immune responses in young lambs that could be used as markers for selection. [ABSTRACT FROM AUTHOR]

Caliche is a highly water-soluble mineral that is exploited in northern Chile for its valuable content of iodine and nitrate, which are used in technological, medical, agriculture, dietary, and industrial applications. The processing of this mineral is through vat or heap leaching, where the species are dissolved using mainly fresh water and intermediate solutions. Since the deposits are located in zones with scarce water availability, one of the challenges for this industry is the search for new sustainable sources of water to face the process requirements. The use of groundwater sources by the mining industry has affected the domestic water supply for the nearest populations, increasing the need for new water alternatives as desalination of seawater by reverse osmosis (RO). A disadvantage of this method is the generation and discharge of highly concentrated brines to sea. In this work, the feasibility to use RO brine for caliche leaching was empirically proved through column-leaching experiments, which showed high recoveries of iodine and nitrate. Therefore, the use of RO brines may be an interesting option, on one side, for covering the increasing demand of processing water and, on the other side, to diminish the negative impact of brine disposal to the sea. [ABSTRACT FROM AUTHOR]

2,4,6-trichlorophenol (TCP) is a toxic compound widespread in the environment, with numerous applications. There are many fungi capable of degrading it, although little attention has been paid to non wood-degrading species. Penicillium [ABSTRACT FROM AUTHOR]

The anaerobic degradation of particulate-containing potato processing wastewater using a mixed culture from an industrial anaerobic wastewater treatment plant as inoculum was characterised and modelled. Anaerobic digestion is being increasingly used for wastewater treatment, particularly those which contain high levels of biodegradable matter such as potato processing effluents. A major prerequisite for its proper modelling is a reliable wastewater characterisation with a proper discrimination of the chemical oxygen demand (COD) fractions. These wastewaters contain both soluble (S) and particulate (X) organic load that are assimilated by microorganisms at different rates. Furthermore, these wastewaters generally contain both solid (X I) and soluble (S I) inert to anaerobic degradation fractions. In this work, a procedure to determine the COD fractions of potato wastewater is developed. For the wastewater studied, the initial fraction of inert particulate organic matter was negligible, while the initial fraction of inert soluble organic matter was 20.94%±1.65. A model with first-order serial-parallel reactions system was developed for biodegradable fractions. This model has demonstrated its capability to predict the behaviour of the system and can be used for further research work or more complex reactor design. [ABSTRACT FROM AUTHOR]

This work was undertaken to investigate the effect of variations of the feed rate on a fed-batch set-up used to degrade xenobiotics. The mixture of substrates was composed of PCP, 2,4,6 TCP and 2,3,5,6 TeCP (pentachlorophenol, 2,4,6 trichlorophenol and 2,3,5,6 tetrachlorophenol respectively). Two acclimated bacteria isolated from soil were used: Pseudomonas aeruginosa and Achromobacter sp. nov. The different flow rates tested were: I: 0.5 mℓ∙min-1, II: 1.67 mℓ∙min-1 and III: 2.00 mℓ∙min-1. Our results show that during fed-batch operation the 2,4,6 TCP exhibits an earlier degradation than the other compounds, for all of the flow rates tested. This indicates that in this case the degradation of the most recalcitrant compounds (PCP and 2,3,5,6 TeCP) is benefited by the increase in biomass of bacteria, due to the metabolisation of a less recalcitrant compound (2,4,6 TCP). The defined parameter, specific degradation rate (SDR), was demonstrated to be very useful for comparing the degradation abilities at different flow rates of a fed-batch system. The degradation efficiencies were shown to be higher than 90% for all of the cases and to decrease as the feed rate increases. However, the SDR, a parameter that involves the rate of degradation and the biomass, increases as the flow rate increases. At a feed flow rate of 2 mℓ∙min-1 SDR reaches a maximum of 12.476 x 10-10 mgCP∙h-1∙CFU-1. Finally, among the feed flows tested, taking into account both the degradation efficiency and the SDR, 2 mℓ∙min-1 is the most convenient flow rate for chlorophenol degradation in fed-batch systems. An even higher degradation efficiency (97%) can be achieved by using the feed rate of 2 mℓ∙min-1 followed by an additional batch post-treatment of 2 h, with a SDR of 13.136 x 10-10 mg CP∙h-1∙CFU-1. [ABSTRACT FROM AUTHOR]

Abstract: Giardia duodenalis (syn. Giardia lamblia, Giardia intestinalis) is a wide-spread intestinal protozoa of both humans and animals. Although giardiosis in goat is commonly asymptomatic, young kids may bear an enteric disease associated with persistent diarrhoea and delayed weight gain. In the present study we have analysed the occurrence of Giardia in 315 young goat kids (2–6 months old) from Gran Canaria Island (Spain) through visualization of faecal cysts. The identification of genotypes of G. duodenalis among the farms was attained by nested PCR of the triophosphate isomerase (TPI) and single PCR of β-giardin genes and subsequent sequencing. Positive samples were found in 42.2% of the animals and 95.5% of the farms. Goat faecal specimens were positive for only livestock-associated G. duodenalis assemblage E genotype for both TPI and β-giardin genes. The genetic analysis of these two loci revealed the presence of different haplotypes among the farms included in the survey and high homology with homologous genes from cattle and sheep. Altogether, the data presented here provide additional information to the prevalence and genetic characterization of Giardia isolates. The absence of assemblages A and B in this study suggests that zoonotic transmission of Giardia from goats could be of low epidemiological significance, although these findings should be validated in studies including other geographical areas, age groups and larger number of samples. [Copyright &y& Elsevier]

Teladorsagia circumcincta is an abomasal parasitic nematode that can cause serious issues in small ruminant production, which are aggravated by drug resistance. Vaccines have been suggested as a feasible, long-lasting alternative for control since adaptation to the host's immune mechanisms by helminths develops at a much slower pace than anthelmintic resistance. Recently, a T. circumcincta recombinant subunit vaccine yielded over a 60% reduction in egg excretion and worm burden and induced strong humoral and cellular anti-helminth responses in vaccinated 3-month-old Canaria Hair Breed (CHB) lambs, but Canaria Sheep (CS) of a similar age were not protected by the vaccine. Here, we compared the transcriptomic profiles in the abomasal lymph nodes of such 3-month-old CHB and CS vaccinates 40 days after infection with T. circumcincta to understand differences in responsiveness at the molecular level. In the CS, differentially expressed genes (DEG) identified were related to general immunity processes such as antigen presentation or antimicrobial proteins and down-regulation of inflammation and immune response through regulatory T cell-associated genes. However, upregulated genes in CHB vaccinates were associated with type-2 oriented immune responses, i.e., immunoglobulin production, activation of eosinophils, as well as tissue structure and wound repair-related genes and protein metabolism pathways such as DNA and RNA processing. These results highlight potentially more optimal timing and orientation of immune responses in CHB sheep compared to CS associated with vaccine-induced protection. The data obtained in this study thus deepens our understanding of variations in responsiveness to vaccination in young lamb and provides insights for vaccine refinement strategies. • A Teladorsagia circumcincta vaccine protected weaned lambs of worm-resistant breed. • Transcriptomic profiles of vaccinates may explain differences in responsiveness. • Down-regulation of inflammation-related genes were overexpressed in non-responders. • Th2, wound repair, protein metabolism-related genes were upregulated in responders. [ABSTRACT FROM AUTHOR]

Canaria Hair Breed (CHB) sheep display resistance against the adult stage of the nematode, Haemonchus contortus . Previous studies have suggested significant correlations between γδ + T lymphocytes and fecundity of female adult worms, suggesting a novel role in immune modulation by these cells. The largest proportion of γδ + T lymphocytes in sheep are the subpopulation of γδ + /WC1 + T cells. The aim of this study was to evaluate the effect of γδ + ⁄WC1 + T cell depletion via infusion of anti-γδ/WC1 monoclonal antibody (mAb) on the subsequent immune response of CHB sheep infected with H. contortus . Significantly lower γδ + T cell levels in both peripheral blood and in the basal layers of the abomasal tissue resulted following anti-γδ/WC1 mAb infusion of CHB sheep compared to control animals. Worms recovered from the anti-γδ/WC1 mAb treated CHB sheep had significantly longer female worms with correspondingly more eggs in utero than the saline control group. Significant correlations between eosinophils and worm length and fecundity were no longer apparent in the anti-γδ/WC1 mAb treated CHB sheep. These results support the notion that γδ + T cells in CHB sheep play a critical role in fecundity regulation (length and eggs in utero ) of H. contortus adult female worms, and highlights a new mechanism of modulation by this lymphocyte population, possibly involving eosinophil activation. [ABSTRACT FROM AUTHOR]

The aim of the present work was to design a methodology based on video processing to obtain indicators of bacterial population motility that allow the quantitative and qualitative analysis and comparison of the chemotactic phenomenon with different attractants in the agarose-in plug bridge method. Video image sequences were processed applying Shannon's entropy to the intensity time series of each pixel, which conducted to a final pseudo colored image resembling a map of the dynamic bacterial clusters. Processed images could discriminate perfectly between positive and negative attractant responses at different periods of time from the beginning of the assay. An index of spatial and temporal motility was proposed to quantify the bacterial response. With this index, this video processing method allowed obtaining quantitative information of the dynamic changes in space and time from a traditional qualitative assay. We conclude that this computational technique, applied to the traditional agarose-in plug assay, has demonstrated good sensitivity for identifying chemotactic regions with a broad range of motility. [ABSTRACT FROM AUTHOR]

Gastrointestinal nematode (GIN) infections are a serious drawback on small ruminant production. Since anthelmintic resistance has extended, optimisation of alternative non-chemical control strategies has attracted interest. Recently, a prototype recombinant vaccine protected immunologically mature sheep from Texel-cross and Canaria Sheep breeds against Teladorsagia circumcincta. The level of protective immunity stimulated by the vaccine varied between individuals and with age. Previous studies suggest that Canaria Hair Breed (CHB) sheep is naturally resistant to GIN infection, with some evidence suggesting that this protection is present in young lambs. Here, we sought to enhance this resistance by immunising three-month-old CHB lambs with a T. circumcincta prototype recombinant vaccine. Following vaccination and a larval challenge period, levels of protection against T. circumcincta infection were compared in CHB lambs with Canaria Sheep (CS) lambs (a breed considered less resistant to GIN). Lambs from the resistant CHB breed appeared to respond more favourably to vaccination, shedding 63% fewer eggs over the sampling period than unvaccinated CHB lambs. No protection was evident in CS vaccinated lambs. At post-mortem, CHB vaccine recipients had a 68% reduction in mean total worm burden, and female worms were significantly shorter and contained fewer eggs in utero compared to unvaccinated CHB lambs. A higher anti-parasite IgG 2 level was detected in immunised CHB lambs compared to unvaccinated control CHB animals, with data suggesting that IgA, globular leucocytes, CD45RA+, CD4+ and CD8+ T cells are implicated in this protective response. The development of effective immunity in vaccinated CHB lambs did not reduce lamb growth rate as immunised CHB lambs had a significantly higher average daily weight gain after challenge than their unvaccinated counterparts. Therefore, the protection of CHB lambs was enhanced by immunisation at weaning, suggesting a synergistic effect when combining vaccination with presumed genetic resistance. [Display omitted] • A recombinant vaccine protected lambs against Teladorsagia circumcincta infection. • Vaccination reduced parasitological variables in a resistant local breed. • IgA, IgG2, Globule Leucocytes, CD45RA, CD4 and CD8 were involved in protection. • The development of immunity in vaccinated CHB lambs did not stunt lamb growth. • Synergistic effect through the combination of vaccination and genetic resistance. [ABSTRACT FROM AUTHOR]

Eosinophils are prominent effector cells in immune responses against gastrointestinal nematode infections in ruminants, but their in vivo role has been hard to establish in large animals. Interleukin‐5 is a key cytokine in the induction and stimulation of anti‐parasitic eosinophil responses. This study attempted to modulate the eosinophil response in sheep through vaccination with recombinant interleukin‐5 (rIL‐5) and determine the effect on subsequent Haemonchus contortus infection. Nematode‐resistant Canaria Hair Breed (CHB) sheep vaccinated with rIL‐5 in Quil‐A adjuvant, had lower blood eosinophil counts and higher mean worm burdens than control sheep vaccinated with Quil‐A adjuvant alone. In addition, adult worms in IL‐5‐vaccinated sheep were significantly longer with higher eggs in utero in female worms, supporting an active role of eosinophils against adult parasites in CHB sheep. These results confirm that eosinophils can play a direct role in effective control of H contortus infection in sheep and offer a new approach to study immune responses in ruminants. [ABSTRACT FROM AUTHOR]