Formyl peptide receptor 2 (FPR2) antagonism is a potential target for the prevention of Brucella abortus 544 infection.

Here, we explore the potential role of formyl peptide receptor 2 (FPR2) during Brucella abortus infection. FPR2 manipulation affected B. abortus internalization but not its growth within macrophages. During the activation of FPR2 induced by its agonist AGP-8694, a high level of Brucella uptake was accompanied by an increase in ERK phosphorylation, while intracellular survival at 24 h postincubation was observed to be associated with slightly reduced nitrite accumulation but augmented superoxide anion production. Attenuated secretion of IL-6 and IL-10 were observed 48 h postincubation in the bone marrow-derived macrophages (BMDMs) treated with the FPR2 antagonist WRW4. An opposite pattern of bacterial uptake was observed upon treatment with the FPR2 antagonist, but no significant changes in the activation of MAPKs or the production of nitrite or superoxide anion were observed. Interestingly, AGP-8694 treatment of mice did not lead to differences in spleen or liver weight but slightly enhanced bacterial proliferation was observed in the spleen. Although the weights of the spleen or liver did not differ, WRW4 treatment led to reduced bacterial proliferation in the spleen. Furthermore, FPR2 antagonist treatment was associated with high serum levels of the proinflammatory cytokines IL-12, TNF-α, IFN-γ and MCP-1, while the production of TNF-α was inhibited in AGP-8694-treated mice. IL-6 and IL-10 levels were slightly increased in AGP-8694-treated mice at 24 h postinfection. Our findings demonstrated the contribution of FPR2 via manipulating this receptor using its reported agonist AGP-8694 and antagonist WRW4 in both in vitro and in vivo systems. Although activation of the receptor did not consistently induced Brucella infection, FPR2 inhibition may be a promising strategy to treat brucellosis in animals which encourages further investigation.

Adenosine receptor Adora2b antagonism attenuates Brucella abortus 544 infection in professional phagocyte RAW 264.7 cells and BALB/c mice.

Brucella as a stealthy intracellular pathogen avoids activation of innate immune response. Here we investigated the contribution of an adenosine receptor, Adora2b, during Brucella infection in professional phagocyte RAW 264.7 cells and in a murine model. Adora2b-deficient cells showed attenuated Brucella internalization and intracellular survival with enhanced release of IL-6, TNF-α, IL-12 and MCP-1. In addition, blockade of Adora2b using MRS 1754 treatment in mice resulted in increased total weight of the spleens but suppressed bacterial burden in these organs accompanied by elevated levels of IL-6, IFN-γ, TNF-α, IL-12 and MCP-1, while reduced IL-10. Overall, we proposed that the Adora2b participates in the successful phagocytic pathway and intracellular survival of Brucella in RAW 264.7 cells, and could be a potential therapeutic target for the treatment of acute brucellosis in animals.

ß-Sitosterol Contributes in the Resistance to Invasion and Survival of Brucella abortus 544 within RAW264.7 Cells, and Cytokine Production with Reduced Susceptibility to Infection in BALB/c Mice.

We previously identified ß-sitosterol (BS) as one of the most abundant compounds found in Korean red ginseng oil. BS is a widely prevalent vegetable-derived phytosterol with many known health benefits. Here, we investigated the efficacy of BS against Brucella (B.) abortus infection. BS showed no effect on bacterial growth but attenuated internalization, intracellular survival and MAPKs-linked intracellular signaling in RAW264.7 cells. BS treatment in cells is also associated with increased nitrite concentration during infection at 24 h. Slightly enhanced resistance to B. abortus infection was observed in mice orally given BS, which could be mediated by induced production of proinflammatory cytokines. Taken together, our study demonstrates the contribution of BS treatment against B. abortus infection although further investigation is encouraged to maximize its beneficial effects against intracellular infection.

The immunomodulatory effect of antimicrobial peptide HPA3P restricts Brucella abortus 544 infection in BALB/c mice.

The discovery of antimicrobial peptides (AMPs) in recent years has been promising for the treatment of multidrug resistant pathogenic microbes. Brucellosis is still considered one of the most common zoonoses in the world. In this study, we evaluated the effect HPA3P peptide in the bacterial uptake and intracellular growth of Brucella abortus (B. abortus) 544 in murine macrophages RAW 264.7. HPA3P was further utilized in a mouse model for infection and treatment. This peptide did not show cytotoxicity or bactericidal effect to B. abortus. However, it inhibited bacterial internalization at 0, 15 and 30 min incubation at two different doses at 12 and 24 µM as well as reduced intracellular growth after 2, 24 and 48 h incubation. Mice treated with HPA3P demonstrated a significant 1.01-log reduction (P < 0.0001) and spleen weight reduction compared to the nanocarrier control (P < 0.01). Significant increases in key cytokines Interferon-γ (IFN-γ) and Tumor necrosis factor (TNF) at 3, 7 and 14 days post-infection were observed in HPA3P treated mice similar to the antibiotic control group with both compared to the nanocarrier control. Monocyte chemoattractant protein-1 (MCP-1) was also heightened at 14 days post-infection. Histopathological analysis also suggests reduced bacterial granuloma in the liver and spleens of HPA3P treated group compared with the nanocarrier control group. In this study, the modulation of crucial cytokines IFN-γ and TNF might have led to a considerable reduction in the proliferation of B. abortus in a mouse model of brucellosis. Further investigation might be required to maximize the efficacy of HPA3P treatment in murine brucellosis.

Emodin Successfully Inhibited Invasion of Brucella abortus Via Modulting Adherence, Microtubule Dynamics and ERK Signaling Pathway in RAW 264.7 Cells.

The aim of this work is to investigate the protective efficacy of emodin, an active, naturally-occurring anthraquinone derivative of several traditional Chinese herbs, against Brucella abortus infection in macrophages. Brucella were incubated with different concentrations of emodin and showed that bacterial survival rates were markedly reduced in a dose-dependent manner at increasing incubation time points. Through bacterial infection assay, the highest non-cytotoxic concentration of emodin demonstrated attenuated invasion of Brucella into macrophages, however it did not inhibit the growth of these pathogens within the host cells. On the other hand, emodin effectively decreased the number of bacteria that adhered to host cells, which indicated its potential as an anti-adhesin agent. Furthermore, using immunoblotting and FACS assay for detecting MAPK signaling proteins and F-actin polymerization, respectively, the results showed that the emodin-incubated cells displayed modest reduction in the phosphorylation levels of ERK1/2 and inhibition of F-actin polymerization as compared to control cells. These findings indicate the potential use of emodin as a naturally-occurring alternative method for the prevention of animal brucellosis although this requires confirmation of safe clinical doses.

Pigs, pooches and pasteurisation: The changing face of brucellosis in Australia

BACKGROUND: Brucellosis, also known as undulant, Mediterranean or Malta fever, is a systemic infection that causes fever, sweats, arthralgias and myalgias. A globally important disease, brucellosis is re-emerging in Australia in association with feral pig hunting activities. OBJECTIVE: This article aims to provide clinicians with an overview of brucellosis, covering epidemiology, clinical features, diagnosis, management and prevention. DISCUSSION: Brucellosis should be suspected in all patients with non-specific, flu-like illness who fall into one of the major risk groups (feral pig hunters, overseas travellers and migrants). Depression is common and often severe, relative to other symptoms. Early diagnosis and treatment are important for preventing complications, which include osteoarticular, genitourinary or, more rarely, neurological or cardiovascular diseases. Diagnosing acute infections is based on serology and blood cultures; imaging and biopsy may be required for diagnosis of focal infections. Dual therapy with doxycycline and gentamicin is the recommended treatment. Relapse occurs in up to 10% of patients. Prevention is achieved through the use of protective gear during hunting and avoidance of unpasteurised dairy products in countries where occur in animals.

Tannic acid-mediated immune activation attenuates Brucella abortus infection in mice.

Brucellosis is an emerging infectious disease affecting humans and animals. In this study, we investigated the in vitro and in vivo effects of tannic acid (TA) against Brucella abortus infection. After infection, F-actin polymerization and mitogen-activated protein kinases (MAPKs) (ERK 1/2 and p38α) phosphorylation were reduced in TA-treated cells compared with that in control cells. The mice were infected via an intraperitoneal route and were orally given TA or phosphate-buffered saline for 14 days. Spleen weights of the TA-treated and control mice were not different; however, splenic proliferation of B. abortus was significantly reduced in the TA-treated group. Immune response analysis showed that, compared with the control group, non-infected TA-treated mice displayed increased levels of interferon-γ (IFN-γ), monocyte chemoattractant protein-1 (MCP-1), and interleukin-10 at 3 days post-infection and a further increase in IFN-γ and MCP-1 at 14 days post-infection. In contrast, compared with the control group, infected TA-treated mice displayed elevated levels of IFN-γ at 3 days post-infection, which continued to increase at 14 days post-infection, as was also observed for tumor necrosis factor. Taken together, the results showing TA activation of cytokine production and inhibition of bacterial proliferation in the host highlight a potential use of TA treatment in the control of Brucella infection.

Multivalent Fusion DNA Vaccine against Brucella abortus.

As an alternative brucellosis prevention method, we evaluated the immunogenicity induced by new multivalent DNA vaccines in BALB/c mice. We constructed the vaccines by fusion of BAB1_0273 and/or BAB1_0278 open reading frames (ORFs) from genomic island 3 (GI-3) and the Brucella abortus 2308 sodC gene with a link based on prolines and alanines (pV273-sod, pV278-sod, and pV273-278-sod, resp.). Results show that immunization with all tested multivalent DNA vaccines induced a specific humoral and cellular immune response. These novel multivalent vaccines significantly increased the production of IgM, IgG, and IgG2a antibodies as well as IFN-γ levels and the lymphoproliferative response of splenocytes. Although immunization with these multivalent vaccines induced a typical T-helper 1- (Th1-) dominated immune response, such immunogenicity conferred low protection levels in mice challenged with the B. abortus 2308 pathogenic strain. Our results demonstrated that the expression of BAB1_0273 and/or BABl_0278 antigens conjugated to SOD protein can polarize mice immunity to a Th1-type phenotype, conferring low levels of protection.

Chronic Brucella Infection Induces Selective and Persistent Interferon Gamma-Dependent Alterations of Marginal Zone Macrophages in the Spleen.

The spleen is known as an important filter for blood-borne pathogens that are trapped by specialized macrophages in the marginal zone (MZ): the CD209+ MZ macrophages (MZMs) and the CD169+ marginal metallophilic macrophages (MMMs). Acute systemic infection strongly impacts MZ populations and the location of T and B lymphocytes. This phenomenon has been linked to reduced chemokine secretion by stromal cells. Brucella spp. are the causative agent of brucellosis, a widespread zoonotic disease. Here, we used Brucella melitensis infection as a model to investigate the impact of chronic stealth infection on splenic MZ macrophage populations. During the late phase of Brucella infection, we observed a loss of both MZMs and MMMs, with a durable disappearance of MZMs, leading to a reduction of the ability of the spleen to take up soluble antigens, beads, and unrelated bacteria. This effect appears to be selective as every other lymphoid and myeloid population analyzed increased during infection, which was also observed following Brucella abortus and Brucella suis infection. Comparison of wild-type and deficient mice suggested that MZ macrophage population loss is dependent on interferon gamma (IFN-γ) receptor but independent of T cells or tumor necrosis factor alpha receptor 1 (TNF-αR1) signaling pathways and is not correlated to an alteration of CCL19, CCL21, and CXCL13 chemokine mRNA expression. Our results suggest that MZ macrophage populations are particularly sensitive to persistent low-level IFN-γ-mediated inflammation and that Brucella infection could reduce the ability of the spleen to perform certain MZM- and MMM-dependent tasks, such as antigen delivery to lymphocytes and control of systemic infection.

Intracellular Trafficking Modulation by Ginsenoside Rg3 Inhibits Brucella abortus Uptake and Intracellular Survival within RAW 264.7 Cells.

Ginsenoside Rg3, a saponin extracted from ginseng, has various pharmacological and biological activities; however, its effects against Brucella infection are still unclear. Herein, the inhibitory effects of ginsenoside Rg3 against intracellular parasitic Brucella infection were evaluated through bacterial infection, adherence assays, and LAMP-1 colocalization, as well as immunoblotting and FACS for detecting MAPK signaling proteins and F-actin polymerization, respectively. The internalization, intracellular growth, and adherence of Brucella abortus in Rg3-treated RAW 264.7 cells were significantly decreased compared with the Rg3-untreated control. Furthermore, an apparent reduction of F-actin content and intensity of F-actin fluorescence in Rg3-treated cells was observed compared with B. abortus-infected cells without treatment by flow cytometry analysis and confocal microscopy, respectively. In addition, treating cells with Rg3 decreased the phosphorylation of MAPK signaling proteins such as ERK 1/2 and p38 compared with untreated cells. Moreover, the colocalization of B. abortus-containing phagosomes with LAMP-1 was markedly increased in Rg3-treated cells. These findings suggest that ginsenoside Rg3 inhibits B. abortus infection in mammalian cells and can be used as an alternative approach in the treatment of brucellosis.

Nocodazole treatment interrupted Brucella abortus invasion in RAW 264.7 cells, and successfully attenuated splenic proliferation with enhanced inflammatory response in mice.

Brucellosis is one of the most important and widespread zoonosis worldwide responsible for serious economic losses and considerable public health burden. In this study, we investigated the modulatory effect of a microtubule-inhibitor, nocodazole, on B. abortus infection in murine macrophages and in a mouse model. Nocodazole activated macrophages and directly inhibited the growth of Brucella in a dose-dependent manner. Nocodazole increased adhesion but reduced invasion and intracellular growth of Brucella in macrophages although it did not affect co-localization of Brucella with LAMP-1. In addition, nocodazole negatively affected actin polymerization, and weakly activated ERK and p38α but significantly activated JNK in non-infected cells. After subsequent infection, nocodazole weakly inhibited activation of ERK and p38α. For the in vivo tests, nocodazole -treated mice displayed elevated levels of IFN-γ, MCP-1 and IL-10 while Brucella-infected nocodazole -treated mice showed high levels of TNF, IFN-γ, MCP-1, IL-10 and IL-6 as compared to controls. Furthermore, nocodazole treatment reduced inflammation and Brucella proliferation in the spleens of mice. These findings highlight the potential use of nocodazole for the control of brucellosis although further investigations are encouraged to validate its therapeutic use in animal hosts.

A dual-targeting approach to inhibit Brucella abortus replication in human cells.

Brucella abortus is an intracellular bacterial pathogen and an etiological agent of the zoonotic disease known as brucellosis. Brucellosis can be challenging to treat with conventional antibiotic therapies and, in some cases, may develop into a debilitating and life-threatening chronic illness. We used multiple independent assays of in vitro metabolism and intracellular replication to screen a library of 480 known bioactive compounds for novel B. abortus anti-infectives. Eighteen non-cytotoxic compounds specifically inhibited B. abortus replication in the intracellular niche, which suggests these molecules function by targeting host cell processes. Twenty-six compounds inhibited B. abortus metabolism in axenic culture, thirteen of which are non-cytotoxic to human host cells and attenuate B. abortus replication in the intracellular niche. The most potent non-cytotoxic inhibitors of intracellular replication reduce B. abortus metabolism in axenic culture and perturb features of mammalian cellular biology including mitochondrial function and receptor tyrosine kinase signaling. The efficacy of these molecules as inhibitors of B. abortus replication in the intracellular niche suggests "dual-target" compounds that coordinately perturb host and pathogen are promising candidates for development of improved therapeutics for intracellular infections.

Inhibitory effect of red ginseng acidic polysaccharide from Korean red ginseng on phagocytic activity and intracellular replication of Brucella abortus in RAW 264.7 cells.

Korean red ginseng (KRG) has long been used in traditional Korean and Oriental medicine. However, the anti-bacterial mechanism and therapeutic efficiency of KGR for intracellular Brucella infection are still unclear. In this study, the bactericidal activity of Korean red ginseng acidic polysaccharide (RGAP) on Brucella (B.) abortus and its cytotoxic effects on RAW 264.7 cells were evaluated. In addition, B. abortus internalization and intracellular replication in macrophages were investigated after RGAP treatment. RGAP-incubated cells displayed a marked reduction in the adherence, internalization and intracellular growth of B. abortus in macrophages. Furthermore, decreased F-actin fluorescence was observed relative to untreated B. abortus-infected cells. Western blot analysis of intracellular signaling proteins revealed reduced ERK, JNK and p38α phosphorylation levels in B. abortus-infected RGAP-treated cells compared to the control. Moreover, elevated co-localization of B. abortus-containing phagosomes with lysosome-associated membrane protein 1 (LAMP-1) were observed in RGAP-treated cells compared with the control. Overall, the results of this study suggest that RGAP can disrupt phagocytic activity of B. abortus via suppression of mitogen-activated protein kinases (MAPKs) signaling proteins ERK, JNK and p38 levels and inhibit intracellular replication of B. abortus by enhancing phagolysosome fusion, which may provide an alternative control of brucellosis.

Dextran sulfate sodium upregulates MAPK signaling for the uptake and subsequent intracellular survival of Brucella abortus in murine macrophages.

Brucellosis is one of the major zoonoses worldwide that inflicts important health problems in animal and human. Here, we demonstrated that dextran sulfate sodium (DSS) significantly increased adhesion of Brucella (B.) abortus in murine macrophages compared to untreated cells. Even without infection, Brucella uptake into macrophages increased and F-actin reorganization was induced compared with untreated cells. Furthermore, DSS increased the phosphorylation of MAPKs (ERK1/2 and p38α) in Brucella-infected, DSS-treated cells compared with the control cells. Lastly, DSS markedly increased the intracellular survival of Brucella abortus in macrophages by up to 48 h. These results suggest that DSS enhanced the adhesion and phagocytosis of B. abortus into murine macrophages by stimulating the MAPK signaling proteins phospho-ERK1/2 and p38α and that DSS increased the intracellular survival of B. abortus by inhibiting colocalization of Brucella-containing vacuoles (BCVs) with the late endosome marker LAMP-1. This study emphasizes the enhancement of the phagocytic and intracellular modulatory effects of DSS, which may suppress the innate immune system and contribute to prolonged Brucella survival and chronic infection.

Methyl gallate limits infection in mice challenged with Brucella abortus while enhancing the inflammatory response.

AIMS: To investigate the effects of methyl gallate (MG) on murine macrophages, cytokine production and treatment of Brucella abortus infection using a mouse model. METHODS AND RESULTS: MG-treated cells displayed increased F-actin polymerization and modest increase in ERK, JNK and p38α phosphorylation levels. The mice were intraperitoneally infected with Br. abortus and were orally treated with PBS or MG for 14 days. The weight and bacterial number from each spleen were monitored, and the serum was evaluated for cytokine production. The spleen proliferation and bacterial burden were lower in the MG-treated group than in the MG-untreated control. The noninfected MG-treated mice displayed increased production of TNF, IFN-γ, and the chemokine MCP-1, whereas the Br. abortus-infected MG-treated mice revealed enhanced induction of IL-12p70, TNF and IL-10 compared to the MG-untreated control. CONCLUSIONS: MG induced F-actin polymerization and modest upregulation of MAPKs. Furthermore, oral treatment with MG induced an immune response and decreased bacterial proliferation in Br. abortus-infected mice, suggesting that MG may be an alternative treatment for brucellosis. SIGNIFICANCE AND IMPACT OF THE STUDY: The present study demonstrates the therapeutic effects of MG against Brucella infection through induction of cytokine production and protection from bacterial proliferation in the spleens of mice.

The effects of red ginseng saponin fraction-A (RGSF-A) on phagocytosis and intracellular signaling in Brucella abortus infected RAW 264.7 cells.

This study indicated that RGSF-A caused a marked reduction in the adherence, internalization and intracellular growth of Brucella abortus in RGSF-A-treated cells. Furthermore, a decline in the intensity of F-actin fluorescence was observed in RGSF-A-treated cells compared with untreated B. abortus-infected cells. In addition, an evaluation of phagocytic signaling proteins by Western blot analysis revealed an apparent reduction of ERK and p38α phosphorylation levels in B. abortus-infected RGSF-A-treated cells compared with the control. Upon intracellular trafficking of the pathogen, a higher number of B. abortus-containing phagosomes colocalized with LAMP-1 in RGSF-A-treated cells compared with control cells. These results strongly suggest that inhibition of B. abortus uptake could be mediated by suppression in the activation of MAPKs signaling proteins phospho-ERK 1/2, and p38 levels. On the other hand, inhibition of intracellular replication results from the enhancement of phagolysosome fusion in host macrophages. This study highlights the phagocytic and intracellular modulating effect of RGSF-A and its potential as an alternative remedy to control B. abortus infection.

Different resistance patterns of reference and field strains of Brucella abortus

The aim of this study was to evaluate the growth of the B. abortus reference strains and field isolates on media containing different inhibitor agents. Reference strains were seeded on tryptose agar containing: i-erythritol (1.0 mg/mL), fuchsin (20 μg/mL and 80 μg/mL), thionin (2.5 μg/mL and 10 μg/mL), rifampicin (200 μg/mL) and safranin O (200 μg/mL). Field isolates were tested only on media containing i-erythritol, rifampicin and thionin. Furthermore, each suspension was also inoculated on tryptose agar incubated in air, to test its ability to grow without CO2. Sensitivity to fuchsin was similar among reference strains evaluated. Growth of S19, 544 and 2308 but not RB51 were inhibited on media containing rifampicin. Medium with safranin O showed no inhibition for RB51, 544 and 2308, but it partially inhibited the S19 growth as well as medium containing i-erythritol. Treatment/control growth ratio for 2308 on tryptose agar containing thionin (2.5 μg/mL) was approximatelly 1.0, whereas S19 and RB51 showed 0.85 and 0.89 ratios, respectively. Growth of 544, S19 and RB51 but not 2308 was completely inhibited on medium with thionin (10 μg/mL). All field strains grew on medium containing i-erythritol, but were completelly inhibited by rifampicin. With exception of A1 (B. abortus biovar 3) all field isolates grew on medium with thionin, although some strains showed a treatment/control growth ratio of 0.75–0.80 (10 μg/mL). These results showed that tryptose agar with thionin, i-erythritol or rifampicin could be useful for differentiating vaccine, challenge and field strains of B. abortus.

Phellinus baumii extract influences pathogenesis of Brucella abortus in phagocyte by disrupting the phagocytic and intracellular trafficking pathway.

AIMS: To clarify the effects of Phellinus baumii ethanol extract (PBE) on Brucella abortus pathogenesis in phagocytes focusing on the phagocytic and intracellular trafficking pathway. METHODS AND RESULTS: The effects of PBE on Br. abortus infection in macrophages were evaluated through an adherence and infection assays and an analysis of LAMP-1 staining. The phosphorylation of ERK1/2 and the F-actin polymerization associated with PBE during Br. abortus uptake were detected by immunoblotting and FACS, respectively. The survival of Br. abortus in pure culture was remarkably reduced by PBE in a dose-dependent manner. PBE-treated cells showed significantly decreased uptake, intracellular replication and adherence of Br. abortus. The declines of ERK1/2 phosphorylation and F-actin polymerization following Br. abortus entry were apparent in PBE-treated cells compared with the control. Moreover, the co-localization of Br. abortus-containing phagosomes with LAMP-1 was elevated in PBE-treated cells compared with the control during intracellular trafficking. CONCLUSION: Phellinus baumii ethanol extract may possess the modulatory effect on pathogenesis of Br. abortus through disrupting the phagocytic and intracellular trafficking pathway in phagocyte. SIGNIFICANCE AND IMPACT OF THE STUDY: The potential modulation of PBE to Br. abortus pathogenesis could provide an alternative approach to control of brucellosis, contributing to attenuate Br. abortus manifestation in hosts.

Redundant effects of ketamine on the pathogenesis and severity of Brucella abortus infection.

Brucella abortus is an intracellular bacterium and leading to a serious debilitating disease known as brucellosis. Ketamine is an anesthetic and a sedative that affects the immunomodulatory activities of various immune cells. The current study was to elucidate the role of ketamine in B. abortus infection, focusing on the phagocytic activity and immune response of macrophages. Following incubation of murine macrophages with ketamine, the phagocytosis of B. abortus was markedly reduced compared with the unincubated control. Interestingly, ketamine-incubated cells displayed a decreased intensity of F-actin fluorescence compared with the B. abortus-induced amplification of intensity. Conversely, the intracellular replication of B. abortus within macrophages was notably enhanced by ketamine. Furthermore, the in vivo assessment using a mouse model revealed that continual injections with ketamine led to augmented bacterial burdens in the spleen, which was accompanied by decreased levels of mRNA expression of cytokines in the spleen. The elevations of serum cytokines such as IFN-γ, IL-12 and IL-6, as well as the chemokine MCP-1, were also reduced by ketamine. These findings verify that ketamine suppresses the phagocytic activity and immune response during B. abortus infection. Therefore, the current study might provide novel insights into the potential influences of ketamine on infectious diseases caused by B. abortus, considering the host-pathogen interaction.