Edwardsiella ictaluri and Flavobacterium covae are pervasive bacterial pathogens associated with significant losses in catfish aquaculture. Bacterial coinfections have the potential to increase outbreak severity and can worsen on-farm mortality. A preliminary assessment of in vivo bacterial coinfection with E. ictaluri (S97-773) and F. covae (ALG-00-530) was conducted using juvenile channel catfish (Ictalurus punctatus). Catfish were divided into five treatment groups: (1) mock control; (2) E. ictaluri full dose (immersion; 5.4 × 105 CFU mL−1); (3) F. covae full dose (immersion; 3.6 × 106 CFU mL−1); (4) E. ictaluri half dose (immersion; 2.7 × 105 CFU mL−1) followed by half dose F. covae (immersion; 1.8 × 106 CFU mL−1); and (5) F. covae half dose followed by half dose E. ictaluri. In the coinfection challenges, the second inoculum was delivered 48 h after the initial exposure. At 21 days post-challenge (DPC), the single dose E. ictaluri infection yielded a cumulative percent mortality (CPM) of 90.0 ± 4.1%, compared with 13.3 ± 5.9% in the F. covae group. Mortality patterns in coinfection challenges mimicked the single dose E. ictaluri challenge, with CPM of 93.3 ± 5.4% for fish initially challenged with E. ictaluri followed by F. covae, and 93.3 ± 2.7% for fish exposed to F. covae and subsequently challenged with E. ictaluri. Despite similarities in the final CPM within the coinfection groups, the onset of peak mortality was delayed in fish exposed to F. covae first but was congruent with mortality trends in the E. ictaluri challenge. Catfish exposed to E. ictaluri in both the single and coinfected treatments displayed increased serum lysozyme activity at 4-DPC (p < 0.001). Three pro-inflammatory cytokines (il8, tnfα, il1β) were evaluated for gene expression, revealing an increase in expression at 7-DPC in all E. ictaluri exposed treatments (p < 0.05). These data enhance our understanding of the dynamics of E. ictaluri and F. covae coinfections in US farm-raised catfish.
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Growth Performance, Survival, Blood Chemistry, and Immune Gene Expression of Channel Catfish (Ictalurus punctatus) Fed Probiotic-Supplemented Diets
The channel catfish (Ictalurus punctatus) farming industry is the largest and one of the oldest aquaculture industries in the United States. Despite being an established industry, production issues stemming from disease outbreaks remain problematic for producers. Supplementing fish diets with probiotics to enhance the immune system and growth potential is one approach to mitigating disease. Although considerable laboratory data demonstrate efficacy, these results do not always translate to natural modes of disease transmission. Hence, the present work was conducted in the laboratory but incorporated flow-through water from large catfish pond production systems, allowing for natural exposure to pathogens. Two feeding trials were conducted in an 18-tank aquaria system housing two different sizes, 34.8 ± 12.5 g and 0.36 ± 0.03 g, of channel catfish. Channel catfish in the first trial were fed three experimental diets over six weeks. Commercial diets were top-coated with two selected spore-forming Bacillus spp. probiotics, Bacillus velezensis AP193 (1 × 106 CFU g−1) and BiOWiSH (3.6 × 104 CFU g−1), or a basal diet that contained no dietary additive. In the second eight-week trial, diets were top-coated with BiOWiSH at three concentrations (1.8, 3.6, and 7.3 × 104 CFU g−1), along with one basal diet (no probiotic). At the completion of these studies, growth performance, survival, hematocrit, blood chemistry, and immune expression of interleukin 1β (il1β), tumor necrosis factor-alpha (tnf-α), interleukin-8 (il8), transforming-growth factor β1 (tgf-β1), and toll-like receptor 9 (tlr9) were evaluated using qPCR. Trial results revealed no differences (p > 0.05) among treatments concerning growth, survival, or hematological parameters. For immune gene expression, interesting trends were discerned, with substantial downregulation observed in B. velezensis AP193-fed fish for il1β, tnf-α, and tlr9 expression within splenic tissue, compared to that of the basal and BiOWiSH diets (p < 0.05). However, the results were not statistically significant for anterior kidney tissue in the first trial. In the second trial, varied levels of probiotic inclusion revealed no significant impact of BiOWiSH’s products on the expression of il1β, tnf-α, il8, and tgf-β1 in both spleen and kidney tissue at any rate of probiotic inclusion (p > 0.05). Based on these findings, more research on utilizing probiotics in flow-through systems with natural infection conditions is crucial to ensure consistency from a controlled laboratory scale to real-world practices.
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- Award ID(s):
- 1922687
- NSF-PAR ID:
- 10446615
- Date Published:
- Journal Name:
- Veterinary Sciences
- Volume:
- 9
- Issue:
- 12
- ISSN:
- 2306-7381
- Page Range / eLocation ID:
- 701
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Objective Subglottic stenosis (SGS) may result from prolonged intubation where fibrotic scar tissue narrows the airway. The scar forms by differentiated myofibroblasts secreting excessive extracellular matrix (ECM). TGF‐β1 is widely accepted as a regulator of fibrosis; however, it is unclear how biomechanical pathways co‐regulate fibrosis. Therefore, we phenotyped fibroblasts from pediatric patients with SGS to explore how key signaling pathways, TGF‐β and Hippo, impact scarring and assess the impact of inhibiting these pathways with potential therapeutic small molecules SB525334 and DRD1 agonist dihydrexidine hydrochloride (DHX).
Methods Laryngeal fibroblasts isolated from subglottic as well as distal control biopsies of patients with evolving and maturing subglottic stenosis were assessed by α‐smooth muscle actin immunostaining and gene expression for α‐SMA, FN, HGF, and CTGF markers. TGF‐β and Hippo signaling pathways were modulated during TGF‐β1‐induced fibrosis using the inhibitor SB525334 or DHX and analyzed by RT‐qPCR for differential gene expression and atomic force microscopy for ECM stiffness.
Results SGS fibroblasts exhibited higher α‐SMA staining and greater inflammatory cytokine and fibrotic marker expression upon TGF‐β1 stimulation (
p < 0.05). SB525334 restored levels to baseline by reducing SMAD2/3 nuclear translocation (p < 0.0001) and pro‐fibrotic gene expression (p < 0.05). ECM stiffness of stenotic fibroblasts was greater than healthy fibroblasts and was restored to baseline by Hippo pathway modulation using SB525334 and DHX (p < 0.01).Conclusion We demonstrate that distinct fibroblast phenotypes from diseased and healthy regions of pediatric SGS patients respond differently to TGF‐β1 stimulation, and SB525334 has the superior potential for subglottic stenosis treatment by simultaneously modulating TGF‐β and Hippo signaling pathways.
Level of Evidence NA
Laryngoscope , 134:287–296, 2024 -
Abstract We examined the effects of dietary supplementation of a blend of mannan and glucan on the growth performance, energy status, and whole-blood immune gene expression of newly weaned beef steers during a 42-d receiving period. Forty-eight newly weaned Angus crossbred steers (2-d post-weaning; 199 ± 13 kg of initial body weight [BW]) from a single source were stratified by BW and randomly assigned to one of the two treatments: basal diet with no additive (CON; n = 24) or a basal diet top-dressed with 5 g of a blend of mannan and glucan (MANGLU; n = 24). Average daily gain (ADG) and feed efficiency (FE) from days 1 to 14, 15 to 42, and 1 to 42 were calculated from daily dry matter intake (DMI) and weekly BW. Blood samples were collected on days 0, 14, and 42 for measurement of plasma glucose and nonesterified fatty acids (NEFA). Blood samples collected on days 14 and 42 were composited for each steer for untargeted carbonyl-metabolome analysis (measurement of carbonyl-containing metabolites). Expression of 84 immune-related genes was analyzed on blood samples collected on day 42. Beginning on days 37 to 42, total mixed ration, refusals, and fecal samples were collected once daily to determine apparent total tract digestibility of DM, CP, NDF, and ADF using indigestible NDF as an internal marker. Over the 42-d feeding trial, supplemental MANGLU tended to increase final BW (P = 0.07) and ADG (P = 0.06). Compared to CON, beef steers fed supplemental MANGLU had greater (P = 0.01) DMI during the first 14 d, greater DM digestibility (P = 0.03), and tended to have greater NDF digestibility (P = 0.09). No treatment effects (P > 0.10) on plasma glucose and NEFA on days 14 and 42 were detected; however, carbonyl-metabolome analysis revealed increased (FDR ≤ 0.05) plasma concentrations of galactose and glyceraldehydes, and altered (FDR ≤ 0.05) concentrations of some microbiome-derived metabolites in beef steers fed MANGLU. Compared with CON, MANGLU increased (P ≤ 0.05) the expression of five immune-related genes involved in recognition of and mounting immune defense against microbial pathogens. In conclusion, the results of this study demonstrated that supplemental MANGLU enhances beef cattle immunocompetence and productivity during feedlot receiving period.more » « less
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Neuroinflammation is one of the hallmarks contributing to Parkinson's disease (PD) pathology, where microglial activation occurs as one of the earliest events, triggered by extracellular α‐synuclein (aSYN) binding to the cluster of differentation 36 (CD36) receptor. Herein, CD36‐binding nanoparticles (NPs) containing tartaric acid–based amphiphilic macromolecules (AMs) are rationally designed to inhibit this aSYN–CD36 binding. In silico docking reveals that four AMs with varying alkyl side chain lengths present differential levels of CD36 binding affinity and that an optimal alkyl chain length promotes the strongest inhibitory activity toward aSYN–CD36 interactions. In vitro competitive binding assays indicate that the inhibitory activity of AM‐based NPs plateaus at intermediate side chain lengths of 12 and 18 carbons, supporting the in silico docking predictions. These intermediate‐length AM NPs also has significantly stronger effects on reducing aSYN internalization and inhibiting proinflammatory molecules tumor necrosis factor α (TNF‐α) and nitric oxide from aSYN‐challenged microglia. All four NPs modulate the gene expression of aSYN‐challenged microglia, downregulating proinflammatory genes TNF, interleukin 6 (IL‐6), and IL‐1β, and upregulating anti‐inflammatory genes transforming growth factor β (TGF‐β) and Arg1 expression. Herein, overall, a novel polymeric nanotechnology platform is represented that can be used to modulate aSYN‐induced microglial activation.
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ABSTRACT Objectives: Compared to formula‐fed infants, breastfed infants have a lower risk of infections. Two possible reasons for this are the presence of the anti‐infective and anti‐inflammatory protein lactoferrin and the lower level of iron in breast milk. We explored how adding bovine lactoferrin and reducing the iron concentration in infant formula affect immunology and risk of infections in healthy infants.
Methods: In a double‐blind controlled trial, term formula‐fed (FF) Swedish infants (n = 180) were randomized to receive, from 6 weeks to 6 months of age, a low‐iron formula (2 mg/L) with added bovine lactoferrin (1.0 g/L) (Lf+; n = 72); low‐iron formula with no added lactoferrin (Lf−; n = 72); and standard formula at 8 mg/L iron and no added lactoferrin (control formula [CF]; n = 36). Cytokines, infections, and infection related treatments were assessed until 12 months of age.
Results: No adverse effects were observed. There were no apparent effects on transforming growth factor beta (TGF‐β)1, TGF‐β2, tumor necrosis factor alfa (TNF‐α) or interleukin2 (IL‐2) at 4, 6, or 12 months, except of higher TGF‐β2 at 6 months in the CF group in comparison to the low iron groups combined (
P = 0.033). No significant differences in otitis, respiratory infections, gastroenteritis, or other monitored infections and treatments were detected for any of the study feeding groups during the first 6 months and only a few and diverging effects were observed between 6 and 12 months.Conclusions: Adding bovine lactoferrin and reducing iron from 8 to 2 mg/L in infant formula was safe. No clinically relevant effects on cytokines or infection related morbidity were observed in this well‐nourished and healthy population.
- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.3390/vetsci9120701
