Nano- and microplastic pollution is increasingly recognized as a global threat to aquatic organisms and human health. These plastics are widespread in both marine and freshwater environments and pose significant risks to fish health. This review explores the routes of exposure, accumulation, and adverse effects of nano- and microplastics on fish, from the organ system to the cellular level. The primary routes of exposure are through ingestion and uptake via the gills. Once inside the body, these plastics accumulate in the gut and gills, penetrate the bloodstream, and bioaccumulate in other tissues. Exposure leads to intestinal and hepatic damage, disrupts digestive enzyme activity, induces oxidative stress, alters gut microbiota and metabolism, and causes digestive tract dysfunction. In the respiratory system, plastic accumulation in the gills induces hyperplasia, excessive mucus secretion, and impairs oxygen exchange. Small-sized particles can enter the bloodstream and reach the heart, causing cardiotoxicity, altered heart rate, and changes in cardiac sarcomeres, along with disruptions in blood biochemical parameters. Upon reaching the nervous system, nano- and microplastics cause neurotoxicity, oxidative stress, cellular damage, and neuroinflammation. Tissue damage and oxidative stress also activate immune responses, including pro-inflammatory reactions and increased expression of immune proteins and molecules. At the cellular level, nanoplastics may accumulate in lysosomes or cross cell membranes, leading to elevated oxidative stress, potential genotoxicity, and membrane damage. The severity of these effects depends on particle size, type, concentration, and duration of exposure. This review aims to enhance understanding of the systemic and cellular toxicities of nano- and microplastics in fish, providing a foundation for future ecological risk assessments and the development of mitigation strategies.

IntroductionBrucella (B.) abortus is an intracellular pathogen that causes chronic infection and remains difficult to treat. In this study, desipramine (DMI) was investigated as a potential host-directed therapeutic strategy to control Brucella infection.MethodsThe effects of DMI on B. abortus infection were evaluated using RAW 264.7 macrophages and an in vivo ICR mouse model. Bacterial growth, uptake, and intracellular survival were assessed in macrophages. Gene expression and signaling pathway analyses were performed to investigate immunomodulatory mechanisms. Infected-mice were treated with DMI, and bacterial loads in target organs, as well as immune responses, were examined.ResultsDMI exhibited a direct inhibitory effect against Brucella growth as well as on the bacterial uptake and intracellular survival within macrophages. This effect was accompanied by increased expression of genes that are known to play crucial roles in the control of Brucella infection. Furthermore, DMI treatment resulted in the suppression of phospho-ERK1/2, MALT1 and Bcl10 protein expression, suggesting that the disruption of Brucella phagocytosis trafficking involves downstream signaling pathways regulated by these proteins. Notably, DMI treatment in Brucella-infected mice significantly reduced bacterial loads in the spleen and showed a decreasing trend in the liver, along with enhanced Th1-associated immune responses.ConclusionTogether, these findings indicate that DMI exhibits both bactericidal and immunomodulatory effects beneficial to the prevention, treatment, and control of Brucella infection.

Brucellosis is a significant zoonotic infection with increasing global prevalence. Traditional treatments rely on antibiotic combinations, but challenges such as drug resistance and relapse necessitate the exploration of alternative therapeutic options. Imipramine hydrochloride (ImiP) has shown potential as an adjunctive treatment for infectious diseases. This study investigates the immunomodulatory effects of ImiP in B. abortus 544 infections in murine macrophages and BALB/c mice. In vitro, RAW 264.7 cells exposed to ImiP exhibited reduced B. abortus replication, decreased nitrite levels, and enhanced bactericidal effects. In vivo, ImiP treatment significantly decreased bacterial loads in the spleen (10 mg/kg, **p < 0.01; 20 mg/kg, *p < 0.05) and liver (10 mg/kg, **p < 0.01; 20 mg/kg, ***p < 0.001), compared to untreated controls. Histopathological analysis revealed minimal liver microgranuloma formation and periportal inflammation in ImiP-treated mice. Moreover, flow cytometry showed decreased CD4+ and CD8+ T cell expression, while serum cytokine profiling indicated a Th1-driven immune response, characterized by elevated levels of IL-12 and decreased IL-10. These findings suggest that ImiP possesses both immunomodulatory and antibacterial effects, highlighting its potential as an adjunctive therapy for brucellosis.

Brucellosis, primarily caused by Brucella abortus, is a significant zoonotic disease affecting cattle worldwide. Accurate and early detection of B. abortus is crucial for effective disease control; however, existing diagnostic methods are limited by low sensitivity, lengthy processing times, and impracticality for field use. In this study, we developed a novel loop-mediated isothermal amplification-lateral flow assay (LAMP-LFA) platform that integrates a biotinylated DNA probe and fluorescein isothiocyanate-labeled primers to detect BruAb2_0168 of B. abortus. Unlike conventional LAMP-based diagnostics, our platform does not entirely prevent nonspecific amplification. Instead, it distinguishes target-specific products from nonspecific products by selective probe hybridization. Only true-positive amplicons hybridize with the probe to produce visible signals on the LFA strip, effectively eliminating the false-positive interpretations that typically limit the diagnostic reliability of LAMP-based methods. We optimized the amplification conditions (temperature, time, and primer/probe concentration) and LFA strip design to ensure high performance. Our platform achieved a detection limit of >= 8.85 CFU/mL, and no cross-reactivity was observed with other common pathogens. Validation using 20 whole-blood samples demonstrated that its diagnostic performance was statistically equivalent to that of polymerase chain reaction (area under the curve = 1.0, McNemar's p > 0.05). The assay reports results within 1 h, requires no instrumentation, and is suitable for use in field or resource-limited settings. Overall, our probe-corrected LAMP-LFA platform offers enhanced specificity, operational simplicity, and field-deployable utility, making it a valuable alternative for rapid and accurate B. abortus diagnosis.

Poultry coccidiosis, caused by 7 Eimeria species, has a significant economic impact on the poultry industry and is managed mainly by chemotherapeutic drugs. However, alternative control measures are needed due to the emergence of drug-resistant strains. This study aimed to evaluate the anticoccidial effects of a multicomplex mineral-based diet in broilers infected with Eimeria acervulina. Broilers were fed a multicomplex mineral-based diet and infected with E. acervulina. Fecal oocyst shedding was 39.0% lower in the E. acervulina-infected broilers treated with the multicomplex mineral compared to that in untreated-infected broilers (365.7×106±45.7 versus 599.8×106±8.7, P<0.05). On day 6 post-infection, body weight gain was significantly higher in treated-infected chickens than untreated chickens (103.2±1.5% versus 94.1±1.7%, P<0.001). The lesion scores were similar between the 2 groups. Histopathological observations revealed that the width of the villi in the treated-infected chickens (286±9.5 μm) was significantly increased by 19.1% (240±10.8 μm, P<0.05) and 34.9% (212±7.3 μm, P<0.001) compared to those in the untreated-uninfected and untreated-infected groups, respectively. However, the villous height and crypt depth were similar between the untreated- and treated-infected groups. The positive effects of the dietary multicomplex mineral, including reduced fecal oocyst shedding, increased weight gain, and increased villi width, suggest its potential application in mitigating the adverse effects of Eimeria infection in both conventional and organic chicken industries.

Objective:This study aims to evaluate the blood gas results in various rabbit disease models and to establish the reference interval of venous and arterial blood gas parameters for clinically healthy and diseased rabbits. The primary purpose of this study is to evaluate various disease effects on acid-base and electrolyte disturbance and to examine the clinical value of blood gas analysis in rabbits. Methods:Two hundred rabbits with various breeds were included in the study. Rabbits were divided into dental, gastrointestinal, musculoskeletal, and urologic disease model groups and one clinically healthy group. Venous and arterial blood gas analyses were performed with a point-of-care blood gas analyzer, i-Smart 300 VET Blood Gas Analyzer (i-SENSE, Korea). The reference intervals for the blood gas results were established. Reference intervals for each diseased group were compared with a clinically healthy control group to analyze the disease's effect on blood gas values. Results:Several acid-base and electrolyte derangements were confirmed. The dental disease model had lower pH (power of hydrogen), PCO2 (partial pressure of carbon dioxide), and HCO3 (bicarbonate) than the control group (p-values < 0.001 by t-tests for both pH and HCO3, and p-value < 0.01 by a t-test for arterial PCO2). The gastrointestinal disease model demonstrated hyponatremia and hypocalcemia compared to the control group, with the p-values < 0.01 by t-tests for both sodium and calcium. The musculoskeletal disease model had lower Hct (hematocrit) and HGB (hemoglobin) than the control (p-values < 0.01 by t-tests for both Hct and HGB). The urologic disease group did not have a statistically significant difference in the reference interval of blood gas results. Conclusions:The results indicated that various disease models in rabbits alter blood gas values. Diseases in body systems correlated with acid-base and electrolyte regulation are more likely to induce blood gas derangements. However, blood gas evaluation in various rabbit diseases is limited. Further studies with more cases in equivalent distribution and other disease models are needed. Clinical relevance:This study is the first to present the reference interval for venous and arterial blood gas results in various disease models of rabbits. Also, this study presented the clinical value of point-of-care blood gas analysis in rabbit diseases. Blood gas analysis has potential diagnostic and prognostic value on various rabbit diseases.

Canine brucellosis is a common zoonosis worldwide, but treatment is challenging due to the stealthy and chronic infection caused by the bacterium Brucella (B.) canis. Antimicrobial peptides (AMPs) are promising candidates for combating drug-resistant microbes, and gold nanoparticle aptamer (AuNP-Apt) aids the delivery of peptides to mammalian cells. This study evaluated the therapeutic efficacy of AuNP-AptHis conjugated antimicrobial peptide RW-BP100His (AuNP-AptHis-RW-BP100His) against B. canis in murine macrophage RAW 264.7 cells and BALB/c mice. In vitro, a high concentration of RW-BP100His alone had a bactericidal effect. AuNP-AptHis-RW-BP100His inhibited intracellular bacterial replication and decreased nitric oxide (NO) production in RAW 264.7 cells infected with B. canis. The production of proinflammatory cytokines in RAW 264.7 cells was elevated after AuNP-AptHis-RW-BP100His treatment. In vivo, AuNP-AptHis-RW-BP100His treatment reduced bacterial burden and microgranulomas in the liver and spleen. CD4+, CD8+ T cells, and Th1 cytokines IFN-γ and TNF were elevated in the treated mice. The results indicate that the therapeutic mechanism of AuNP-AptHis-RW-BP100His is immunomodulation of the infected host to upregulate cell-mediated immunity for B. canis clearance. Therefore, it is a promising candidate to treat canine brucellosis as an alternative to conventional antibiotics.

Serious enteric disease caused by seven species of Eimeira continues to cause significant economic damage to the poultry industry. E. acervulina is one of the most widespread strains in farms and has a significant impact on chicken weight loss. Currently, the use of anticoccidial agents to suppress the occurrence of coccidiosis in farms is considerably restricted due to public health and environmental pollution issues. It is important to understand the protective immunity of the host against Eimeria infections with regard to natural products that could be used as alternatives to anticoccidial agents. Berberine chloride is known for its various biological functions, including its anti-parasite activity. However, its impact on intestinal morphology and immune-related activity in broilers infected with Eimeria still remains unclear. The aim of this study is to evaluate the anticoccidial effects of a berberine-based diet in broilers infected with E. acervulina and to monitor the host immune phenomenon using transcriptomic analysis. Administration of berberine to chickens infected with E. acervulina significantly reduced fecal oocyst production and intestinal lesion scores, and increased duodenal villus height, indicating anticoccidial activity and positive effects on intestinal morphology. Transcriptomic analysis of chickens infected with E. acervulina generally observed the down-regulation of metabolism-related genes and the up-regulation of cell integrity-related genes at day 4 post-infection. At day 6 post-infection, an increase in immune-related genes and cellular-homeostasis-related genes was generally observed. Berberine-treated and E. acervulina-infected chickens showed cytokine-cytokine receptor interaction in the second term in a Kyoto Encyclopedia of Genes and Genomes pathway analysis at day 4 post-infection, but not in chickens infected with E. acervulina alone, suggesting host immune changes induced by berberine. These results suggest that berberine, which exhibits anticoccidial effects, may have therapeutic and/or prophylactic potential in protecting the host from infectious and economic-loss-causing diseases, such as Eimeria infection.

Riemerella anatipestifer (RA) is an economically important pathogen in the duck industry worldwide that causes high mortality and morbidity in infected birds. We previously found that upregulated IL-17A expression in ducks infected with RA participates in the pathogenesis of the disease, but this mechanism is not linked to IL-23, which primarily promotes Th17 cell differentiation and proliferation. RNA sequencing analysis was used in this study to investigate other mechanisms of IL-17A upregulation in RA infection. A possible interaction of IL-26 and IL-17 was discovered, highlighting the potential of IL-26 as a novel upstream cytokine that can regulate IL-17A during RA infection. Additionally, this process identified several important pathways and genes related to the complex networks and potential regulation of the host immune response in RA-infected ducks. Collectively, these findings not only serve as a roadmap for our understanding of RA infection and the development of new immunotherapeutic approaches for this disease, but they also provide an opportunity to understand the immune system of ducks.

Hypertonic saline (HTS) resuscitation can enhance immune responses against various pathogens, however, the effect of HTS on brucellosis is yet to be defined. In this study, we found that HTS inhibited Brucella infection in mice by augmenting Th1 immunity. HTS treatment enhanced the serum cytokines production and the expression of nitric oxide synthase (NOS2) and nuclear factor kappa B (NF-KB) p50 and p65, crucial anti-Brucella effectors in splenocytes. In addition, HTS treatment also inhibited the phosphorylation of MAPK signaling, accompanied by the down-regulation of the autophagy marker LC3B-II. Due to directing an appropriate immune response, HTS treatment substantially decreased bacterial burden in spleen and liver tissues. In summary, corroborating previous studies showing the antimicrobial effects of HTS, our findings indicate that HTS treatment triggers a protective immune response against Brucella infection. Additionally, these results provide promising evidence of the immunomodulatory role of HTS in controlling bacterial infections.

Our preliminary data using bone marrow-derived macrophages (BMDMs) collected from ICR mice treated with anti-sirtuin (anti-SIRT) 1 antibody showed that Brucella uptake was significantly attenuated. We then further investigated the effect of an inhibitor of SIRT1/2, cambinol, in the progression of Brucella. The in vitro results using RAW264.7 cells revealed that cambinol treatment had no effect on adhesion, uptake, intracellular survival and nitric oxide (NO) production during B. abortus infection, nor did it directly affect bacterial growth for up to 72 h. Finally, intraperitoneal treatment of 8-week-old female ICR mice infected with Brucella showed no differences in the total average weights of spleens and livers; however, the treated mice displayed higher Brucella colony-forming units (CFUs) from the spleens. Furthermore, the interleukin (IL)-10 serum level was observed to be lower in treated mice at 7 d post-infection, and none of the cytokines tested showed a change at 14 d post-infection. The overall findings showed that cambinol treatment had no effect on the proliferation of Brucella in RAW264.7 macrophages but exacerbated the splenic proliferation of the bacteria in mice and displayed reduced anti-inflammatory cytokine IL-10 at the first week of infection, suggesting that cambinol as an inhibitory of SIRT1/2 could be beneficial in the context of Brucella dissemination in animal hosts and that exploration of activating SIRTs could be an alternative treatment against Brucella infection.

Catalase, an antioxidant enzyme widely produced in mammalian cells and bacteria, is crucial to mitigating oxidative stress in hostile environments. This function enhances the intracellular survivability of various intracellular growth pathogens, including Brucella (B.) abortus. In this study, to determine whether the suppression of catalase can inhibit the intracellular growth of B. abortus, we employed 3-amino-1,2,4-triazole (3-AT), a catalase inhibitor, in both RAW 264.7 macrophage cells and an ICR mouse model during Brucella infection. The intracellular growth assay indicated that 3-AT exerts growth-inhibitory effects on B. abortus within macrophages. Moreover, it contributes to the accumulation of reactive oxygen species and the formation of nitric oxide. Notably, 3-AT diminishes the activation of the nucleus transcription factor (NF-κB) and modulates the cytokine secretion within infected cells. In our mouse model, the administration of 3-AT reduced the B. abortus proliferation within the spleens and livers of infected mice. This reduction was accompanied by a diminished immune response to infection, as indicated by the lowered levels of TNF-α, IL-6, and IL-10 and altered CD4+/CD8+ T-cell ratio. These results suggest the protective and immunomodulatory effects of 3-AT treatment against Brucella infection.