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Veterinary Microbiology Jun 2014Brucellosis is a zoonotic disease transmitted from an animal reservoir to humans. Both, wildlife and domestic animals, contribute to the spreading of these zoonosis. The...
Brucellosis is a zoonotic disease transmitted from an animal reservoir to humans. Both, wildlife and domestic animals, contribute to the spreading of these zoonosis. The surveillance of the animal health status is strictly regulated for domestic animals, whereas disease monitoring in wildlife does not exist. The aim of the present study was to provide data on the prevalence of anti-Brucella antibodies in Chaetophractus villosus from a region of La Pampa, Argentina to assess public health risks. The C. villosus is endemic to South America, and in Argentina it represents a food resource for human consumption. A total of 150 sera of armadillos bleeding between 2007 and 2010 were tested using buffered plate antigen test (BPAT), serum agglutination test (SAT), 2-mercaptoethanol (2-ME) and complement fixation test (CFT), for the detection of anti-Brucella antibodies. Antibodies to Brucella sp. were found in 16% (24:150) of the armadillos tested using the BPAT test. All 24 positive samples were confirmed by the SAT, 2-ME and CFT tests. Strain isolation was attempted from liver and spleen samples of two animals with positive serology. Isolates were characterized by conventional biotyping and identification of specific DNA using polymerase chain reaction (PCR). A total of 2 isolates were recovered from spleen and liver. Both of them were identified as Brucella suis biovar 1. This preliminary study provides the first report on the seroprevalence of brucellosis and describes the first isolate of B. suis biovar 1 in C. villosus in Argentina.
Topics: Animals; Antibodies, Bacterial; Argentina; Armadillos; Brucella suis; Brucellosis; Female; Liver; Male; Polymerase Chain Reaction; Seroepidemiologic Studies; Spleen
PubMed: 24685240
DOI: 10.1016/j.vetmic.2014.01.039 -
International Journal of Molecular... Jun 2023, the causative agent of brucellosis, poses a significant public health and animal husbandry threat. However, the role of the alanine racemase () gene, which encodes...
, the causative agent of brucellosis, poses a significant public health and animal husbandry threat. However, the role of the alanine racemase () gene, which encodes alanine racemase in , remains unclear. Here, we analyzed an deletion mutant and a complemented strain of S2. The knockout strain displayed an unaltered, smooth phenotype in acriflavine agglutination tests but lacked the core polysaccharide portion of lipopolysaccharide (LPS). Genes involved in the LPS synthesis were significantly upregulated in the deletion mutant. The deletion strain exhibited reduced intracellular viability in the macrophages, increased macrophage-mediated killing, and upregulation of the apoptosis markers. Bcl2, an anti-apoptotic protein, was downregulated, while the pro-apoptotic proteins, Bax, Caspase-9, and Caspase-3, were upregulated in the macrophages infected with the deletion strain. The infected macrophages showed increased mitochondrial membrane permeability, Cytochrome C release, and reactive oxygen species, activating the mitochondrial apoptosis pathway. These findings revealed that alanine racemase was dispensable in S2 but influenced the strain's rough features and triggered the mitochondrial apoptosis pathway during macrophage invasion. The deletion of the gene reduced the intracellular survival and virulence. This study enhances our understanding of the molecular mechanism underlying 's survival and virulence and, specifically, how gene affects host immune evasion by regulating bacterial LPS biosynthesis.
Topics: Animals; Brucella suis; Lipopolysaccharides; Virulence; Alanine Racemase; Brucellosis
PubMed: 37445922
DOI: 10.3390/ijms241310744 -
Frontiers in Cellular and Infection... 2016Brucella has been reported to impair placental trophoblasts, a cellular target where Brucella efficiently replicates in association with the endoplasmic reticulum (ER),...
Brucella has been reported to impair placental trophoblasts, a cellular target where Brucella efficiently replicates in association with the endoplasmic reticulum (ER), and ultimately trigger abortion in pregnant animals. However, the precise effects of Brucella on trophoblast cells remain unclear. Here, we describe the infection and replication of Brucella suis vaccine strain 2 (B.suis.S2) in goat trophoblast cells (GTCs) and the cellular and molecular responses induced in vitro. Our studies demonstrated that B.suis.S2 was able to infect and proliferate to high titers, hamper the proliferation of GTCs and induce apoptosis due to ER stress. Tunicamycin (Tm), a pharmacological chaperone that strongly mounts ER stress-induced apoptosis, inhibited B.suis.S2 replication in GTCs. In addition, 4 phenyl butyric acid (4-PBA), a pharmacological chaperone that alleviates ER stress-induced apoptosis, significantly enhanced B.suis.S2 replication in GTCs. The Unfolded Protein Response (UPR) chaperone molecule GRP78 also promoted B.suis.S2 proliferation in GTCs by inhibiting ER stress-induced apoptosis. We also discovered that the IRE1 pathway, but not the PERK or ATF6 pathway, was activated in the process. However, decreasing the expression of phosphoIRE1α and IRE1α proteins with Irestatin 9389 (IRE1 antagonist) in GTCs did not affect the proliferation of B.suis.S2. Although GTC implantation was not affected upon B.suis.S2 infection, progesterone secretion was suppressed, and prolactin and estrogen secretion increased; these effects were accompanied by changes in the expression of genes encoding key steroidogenic enzymes. This study systematically explored the mechanisms of abortion in Brucella infection from the viewpoint of pathogen invasion, ER stress and reproductive endocrinology. Our findings may provide new insight for understanding the mechanisms involved in goat abortions caused by Brucella infection.
Topics: Activating Transcription Factor 6; Animals; Apoptosis; Brucella Vaccine; Brucella suis; Brucellosis; Cell Proliferation; Cells, Cultured; Endoplasmic Reticulum; Endoplasmic Reticulum Chaperone BiP; Endoplasmic Reticulum Stress; Estrogens; Female; Goat Diseases; Goats; Heat-Shock Proteins; Placenta; Pregnancy; Progesterone; Prolactin; Protein Serine-Threonine Kinases; Reverse Transcriptase Polymerase Chain Reaction; Transcription Factor CHOP; Trophoblasts; Tunicamycin; eIF-2 Kinase
PubMed: 26904517
DOI: 10.3389/fcimb.2016.00019 -
Frontiers in Cellular and Infection... 2021Neurobrucellosis is a chronic complication of human brucellosis that is caused by the presence of spp in the central nervous system (CNS) and the inflammation play a...
Neurobrucellosis is a chronic complication of human brucellosis that is caused by the presence of spp in the central nervous system (CNS) and the inflammation play a key role on the pathogenesis. Doxycycline (Dox) is a widely used antibiotic that induces apoptosis of bacteria-infected cells. However, the mechanisms of inhibition of microglial apoptosis and Dox induction of apoptosis are still poorly understood. In this study, we found that S2 strain ( S2) increased calreticulin (CALR) protein levels and inhbited HMC3 cell apoptosis. Hence, we constructed two HMC3 cell line variants, one with stable overexpression (HMC3-CALR) and one with low expression of CALR (HMC3-sh-CALR). CALR was found to decrease levels of p-JNK and p-p53 proteins, as well as suppress apoptosis in HMC3 cells. These findings suggest that CALR suppresses apoptosis by inhibiting the JNK/p53 signaling pathway. Next, we treated HMC3, HMC3-CALR and HMC3-sh-CALR cell lines with S2 or Dox. Our results demonstrate that S2 restrains the JNK/p53 signaling pathway to inhibit HMC3 cell apoptosis increasing CALR protein expression, while Dox plays the opposite role. Finally, we treated S2-infected HMC3 cells with Dox. Our results confirm that Dox induces JNK/p53-dependent apoptosis in S2-infected HMC3 cells through inhibition of CALR protein expression. Taken together, these results reveal that CALR and the JNK/p53 signaling pathway may serve as novel therapeutic targets for treatment of neurobrucellosis.
Topics: Apoptosis; Brucella suis; Brucellosis; Calreticulin; Doxycycline; Humans; MAP Kinase Signaling System; Microglia; Tumor Suppressor Protein p53
PubMed: 33996626
DOI: 10.3389/fcimb.2021.640847 -
FEMS Microbiology Letters Jan 2023Brucella is the causative agent of brucellosis and can be transmitted to humans through aerosolized particles or contaminated food. Brucella abortus (B. abortus),...
A rapid and sensitive triplex-recombinase polymerase amplification for simultaneous differentiation of Brucella abortus, Brucella melitensi s, and Brucella suis in sera and foods.
Brucella is the causative agent of brucellosis and can be transmitted to humans through aerosolized particles or contaminated food. Brucella abortus (B. abortus), Brucella melitensis (B. melitensis), and Brucella suis (B. suis) are the most virulent of the brucellae, but the traditional detection methods to distinguish them are time-consuming and require high instrumentation. To obtain epidemiological information on Brucella during livestock slaughter and food contamination, we developed a rapid and sensitive triplex recombinant polymerase amplification (triplex-RPA) assay that can simultaneously detect and differentiate between B. abortus, B. melitensis, and B. suis. Three pairs of primers (B1O7F/B1O7R, B192F/B192R, and B285F/B285R) were designed and screened for the establishment of the triplex-RPA assay. After optimization, the assay can be completed within 20 min at 39°C with good specificity and no cross-reactivity with five common pathogens. The triplex-RPA assay has a DNA sensitivity of 1-10 pg and a minimum detection limit of 2.14 × 104-2.14 × 105 CFU g-1 in B. suis spiked samples. It is a potential tool for the detection of Brucella and can effectively differentiate between B. abortus, B. melitensis, and B. suis S2, making it a useful tool for epidemiological investigations.
Topics: Humans; Brucella abortus; Brucella suis; Brucella melitensis; Recombinases; Brucellosis; Nucleotidyltransferases
PubMed: 37309037
DOI: 10.1093/femsle/fnad056 -
Cell Stress & Chaperones May 2015Brucella, which is regarded as an intracellular pathogen responsible for a zoonotic disease called brucellosis, survives and proliferates within several types of...
Brucella, which is regarded as an intracellular pathogen responsible for a zoonotic disease called brucellosis, survives and proliferates within several types of phagocytic and non-phagocytic cells. Brucella infects not only their preferred hosts but also other domestic and wild animal species, inducing abortion and infertility. Therefore, the interaction between uterine cells and Brucella is important for understanding the pathogenesis of this disease. In this study, we describe the Brucella suis vaccine strain S2 (B.suis.S2) infection and replication in the immortalized caprine endometrial epithelial cell line hTERT-EECs and the induced cellular and molecular response modulation in vitro. We found that B.suis S2 was able to infect and replicate to high titers and inhibit the proliferation of EECs and induce non-apoptotic pathways, as determined by B.suis.S2 detection using MTT and acridine orange/ethidium bromide (AO/EB) staining and flow cytometry. We explored the evidence of non-apoptotic pathways using real-time quantitative RT-PCR and by western blot analysis. Finally, we discovered the over-expression of GRP78, ATF4, ATF6, PERK, eIF2α, CHOP, and cytochrome c (Cyt-c) but not IRE1, xbp-1, and caspase-3 in B.suis.S2 (HK)-attacked and B.suis.S2-infected cells, suggesting that the molecular mechanism of ER stress sensor activation by B.suis.S2 is basically concomitant with that by B.suis.S2 (HK) and that ER stress, especially the PERK pathway, plays an important role in the process of B.suis.S2 infecting EEC, which may, in part, explain the role of the uterus in the pathogenesis of B.suis.S2.
Topics: Animals; Apoptosis; Brucella Vaccine; Brucella suis; Brucellosis; Caspase 3; Cell Line; Cell Proliferation; Cell Survival; Cytochromes c; Endoplasmic Reticulum Stress; Epithelial Cells; Goat Diseases; Goats
PubMed: 25633898
DOI: 10.1007/s12192-014-0564-x -
Brucella suis strain 2 vaccine is safe and protective against heterologous Brucella spp. infections.Vaccine Jan 2016Brucellosis is a wide spread zoonotic disease that causes abortion and infertility in mammals and leads to debilitating, febrile illness in humans. Brucella abortus,...
Brucellosis is a wide spread zoonotic disease that causes abortion and infertility in mammals and leads to debilitating, febrile illness in humans. Brucella abortus, Brucella melitensis and Brucella suis are the major pathogenic species to humans. Vaccination with live attenuated B. suis strain 2 (S2) vaccine is an essential and critical component in the control of brucellosis in China. The S2 vaccine is very effective in preventing brucellosis in goats, sheep, cattle and swine. However, there are still debates outside of China whether the S2 vaccine is able to provide protection against heterologous virulent Brucella species. We investigated the residual virulence, immunogenicity and protective efficacy of the S2 vaccine in BALB/c mice by determining bacteria persistence in spleen, serum antibody response, cellular immune response and protection against a heterologous virulent challenge. The S2 vaccine was of low virulence as there were no bacteria recovered in spleen four weeks post vaccination. The vaccinated mice developed Brucella-specific IgG in 2-3 weeks, and a burst production of IFN-γ at one week as well as a two-fold increase in TNF-α production. The S2 vaccine protected mice from a virulent challenge by B. melitensis M28, B. abortus 2308 and B. suis S1330, and the S2 vaccinated mice did not develop any clinical signs or tissue damage. Our study demonstrated that the S2 vaccine is of low virulence, stimulates good humoral and cellular immunity and protects animals against infection by heterologous, virulent Brucella species.
Topics: Animals; Antibodies, Bacterial; Bacterial Load; Brucella Vaccine; Brucella suis; Brucellosis; Cross Protection; Disease Models, Animal; Immunity, Heterologous; Immunoglobulin G; Interferon-gamma; Leukocytes, Mononuclear; Mice, Inbred BALB C; Serum; Spleen; Tumor Necrosis Factor-alpha
PubMed: 26626213
DOI: 10.1016/j.vaccine.2015.09.116 -
Infection, Genetics and Evolution :... Jul 2016Brucellosis is an important zoonotic disease caused by Brucella spp. Brucella suis is the etiological agent of porcine brucellosis. B. suis is the most genetically...
Brucellosis is an important zoonotic disease caused by Brucella spp. Brucella suis is the etiological agent of porcine brucellosis. B. suis is the most genetically diverged species within the genus Brucella. We present the first large-scale B. suis phylogenetic analysis based on an alignment-free k-mer approach of gathering polymorphic sites from whole genome sequences. Genome-wide core-SNP based phylogenetic tree clearly differentiated and discriminated the B. suis biovars and the vaccine strain into different clades. A total of 16,756 SNPs were identified from the genome sequences of 54 B. suis strains. Also, biovar-specific SNPs were identified. The vaccine strain B. suis S2-30 is extensively used in China, which was discriminated from all biovars with the accumulation of the highest number of SNPs. We have also identified the SNPs between B. suis vaccine strain S2-30 and its closest homolog, B. suis biovar 513UK. The highest number of mutations (22) was observed in the phosphomannomutase (pmm) gene essential for the synthesis of O-antigen. Also, mutations were identified in several virulent genes including genes coding for type IV secretion system and the effector proteins, which could be responsible for the attenuated virulence of B. suis S2-30.
Topics: Animals; Bacterial Proteins; Bacterial Vaccines; Base Sequence; Brucella suis; Brucellosis; China; Chromosome Mapping; Genome, Bacterial; Mutation; Phosphotransferases (Phosphomutases); Phylogeny; Polymorphism, Single Nucleotide; Sequence Alignment; Swine; Type IV Secretion Systems; Virulence Factors
PubMed: 27085292
DOI: 10.1016/j.meegid.2016.04.012 -
BMC Veterinary Research Aug 2019Brucellosis is a worldwide zoonotic infectious disease that is transmitted in various ways and causes great harm to humans and animals. The brucellosis pathogen is...
BACKGROUND
Brucellosis is a worldwide zoonotic infectious disease that is transmitted in various ways and causes great harm to humans and animals. The brucellosis pathogen is Brucella, which mainly resides in macrophage cells and survives and replicates in host cells. However, the mechanisms underlying Brucella survival in macrophage cells have not been thoroughly elucidated to date. Peroxiredoxin 6 (Prdx6) is a bifunctional protein that shows not only GSH peroxidase activity but also phospholipase A2 activity and plays important roles in combating oxidative damage and regulating apoptosis.
RESULTS
Recombinant mouse (Mus musculus) Prdx6 (MmPrdx6) was expressed and purified, and monoclonal antibodies against MmPrdx6 were prepared. Using the Brucella suis S2 strain to infect RAW264.7 murine macrophages, the level of intracellular Prdx6 expression first decreased and later increased following infection. Overexpressing Prdx6 in macrophages resulted in an increase in B. suis S2 strain levels in RAW264.7 cells, while knocking down Prdx6 reduced the S2 levels in cells.
CONCLUSIONS
Host Prdx6 can increase the intracellular survival of B. suis S2 strain and plays a role in Brucella infection.
Topics: Animals; Brucella suis; Brucellosis; Female; Gene Expression Regulation; Gene Knockdown Techniques; Macrophages; Mice; Mice, Inbred BALB C; Peroxiredoxin VI; RAW 264.7 Cells
PubMed: 31438945
DOI: 10.1186/s12917-019-2049-8 -
Frontiers in Microbiology 2021BAX inhibitor 1 (BI-1) is an evolutionarily conserved transmembrane protein first identified in a screening process for human proteins that suppress BAX-induced...
BAX inhibitor 1 (BI-1) is an evolutionarily conserved transmembrane protein first identified in a screening process for human proteins that suppress BAX-induced apoptosis in yeast cells. Eukaryotic BI-1 is a cytoprotective protein that suppresses cell death induced by multiple stimuli in eukaryotes. , the causative agent of brucellosis that threatens public health and animal husbandry, contains a conserved gene that encodes BI-1-like protein. To explore the role of the homolog of BI-1, BrBI, in S2, we constructed the deletion mutant strain and its complemented strain. deletion altered the membrane properties of S2 and decreased its resistance to acidic pH, HO, polymyxin B, and lincomycin. Additionally, deleting led to defective growth, cell division, and viability in S2. We then revealed the effect of deletion on the physiological characteristics of S2 via integrated transcriptomic and proteomic analyses. The integrated analysis showed that deletion significantly affected the expression of multiple genes at the mRNA and/or protein levels. Specifically, the affected divisome proteins, FtsB, FtsI, FtsL, and FtsQ, may be the molecular basis of the impaired cell division of the mutant strain, and the extensively affected membrane proteins and transporter-associated proteins were consistent with the phenotype of the membrane properties' alterations of the mutant strain. In conclusion, our results revealed that BrBI is a bacterial cytoprotective protein involved in membrane homeostasis, cell division, and stress resistance in S2.
PubMed: 33584633
DOI: 10.3389/fmicb.2021.632095