Antigenic and molecular evidence of Brucella sp.-associated epididymo-orchitis in frugivorous (Artibeus lituratus) and nectarivorous (Glossophaga soricina) bats in Brazil

This study included 47 free-ranging bats from the State of Minas Gerais, Brazil. Six bats (12.8%) had genital inflammatory lesions, and two of them (one Artibeus lituratus and one Glossophaga soricina, a frugivorous and a nectarivorous, respectively) were diagnosed with Brucella sp. infection through PCR, and antigens in intralesional macrophages were detected using immunohistochemistry

Catálogo Taxonômico da Fauna do Brasil: setting the baseline knowledge on the animal diversity in Brazil

The limited temporal completeness and taxonomic accuracy of species lists, made available in a traditional manner in scientific publications, has always represented a problem. These lists are invariably limited to a few taxonomic groups and do not represent up-to-date knowledge of all species and classifications. In this context, the Brazilian megadiverse fauna is no exception, and the Catálogo Taxonômico da Fauna do Brasil (CTFB) (http://fauna.jbrj.gov.br/), made public in 2015, represents a database on biodiversity anchored on a list of valid and expertly recognized scientific names of animals in Brazil. The CTFB is updated in near real time by a team of more than 800 specialists. By January 1, 2024, the CTFB compiled 133,691 nominal species, with 125,138 that were considered valid. Most of the valid species were arthropods (82.3%, with more than 102,000 species) and chordates (7.69%, with over 11,000 species). These taxa were followed by a cluster composed of Mollusca (3,567 species), Platyhelminthes (2,292 species), Annelida (1,833 species), and Nematoda (1,447 species). All remaining groups had less than 1,000 species reported in Brazil, with Cnidaria (831 species), Porifera (628 species), Rotifera (606 species), and Bryozoa (520 species) representing those with more than 500 species. Analysis of the CTFB database can facilitate and direct efforts towards the discovery of new species in Brazil, but it is also fundamental in providing the best available list of valid nominal species to users, including those in science, health, conservation efforts, and any initiative involving animals. The importance of the CTFB is evidenced by the elevated number of citations in the scientific literature in diverse areas of biology, law, anthropology, education, forensic science, and veterinary science, among others

Brucella ovis mutant in ABC transporter protects against Brucella canis infection in mice and it is safe for dogs.

BACKGROUND/OBJECTIVES:Vaccination is the most important tool for controlling brucellosis, but currently there is no vaccine available for canine brucellosis, which is a zoonotic disease of worldwide distribution caused by Brucella canis. This study aimed to evaluate protection and immune response induced by Brucella ovis ΔabcBA (BoΔabcBA) encapsulated with alginate against the challenge with Brucella canis in mice and to assess the safety of this strain for dogs. METHODS:Intracellular growth of the vaccine strain BoΔabcBA was assessed in canine and ovine macrophages. Protection induced by BoΔabcBA against virulent Brucella canis was evaluated in the mouse model. Safety of the vaccine strain BoΔabcBA was assessed in experimentally inoculated dogs. RESULTS:Wild type B. ovis and B. canis had similar internalization and intracellular multiplication profiles in both canine and ovine macrophages. The BoΔabcBA strain had an attenuated phenotype in both canine and ovine macrophages. Immunization of BALB/c mice with alginate-encapsulated BoΔabcBA (108 CFU) induced lymphocyte proliferation, production of IL-10 and IFN-γ, and protected against experimental challenge with B. canis. Dogs immunized with alginate-encapsulated BoΔabcBA (109 CFU) seroconverted, and had no hematologic, biochemical or clinical changes. Furthermore, BoΔabcBA was not detected by isolation or PCR performed using blood, semen, urine samples or vaginal swabs at any time point over the course of this study. BoΔabcBA was isolated from lymph nodes near to the site of inoculation in two dogs at 22 weeks post immunization. CONCLUSION:Encapsulated BoΔabcBA protected mice against experimental B. canis infection, and it is safe for dogs. Therefore, B. ovis ΔabcBA has potential as a vaccine candidate for canine brucellosis prevention

403 Epithelial hypoxia maintains colonization resistance against Candida albicans

OBJECTIVES/GOALS: Antibiotic treatment sets the stage for intestinal domination by Candida albicanswhich is necessary for development of invasive disease, but the resources driving this bloom remain poorly defined. We sought to determine these factors in order to design novel prophylaxis strategies for reducing gastrointestinal (GI) colonization. METHODS/STUDY POPULATION: We initially developed a generalizable framework, termed metabolic footprinting to determine the metabolites C. albicanspreferentially uses in the mouse GI tract. After identifying the metabolites C. albicansutilizes, we usedin vitro growth assays in the presence and absence of oxygen to validate out metabolomics findings. We next determined if a probiotic E. coli that utilizes oxygen would reduce C. albicanscolonization compared to a mutant E. coli that could not respire oxygen. Finding that oxygen was a necessary resource, we utilized germ-free mice to determine if Clostridiaspp. known to reduce GI oxygen would prevent C. albicanscolonization. Lastly, we sought to see if 5-aminosalicylic acid (5-ASA) could prevent C. albicanscolonization. RESULTS/ANTICIPATED RESULTS: We found that C. albicans preferentially utilizes simple carbohydrates including fructo-oligosaccharides (e.g., 1-kestose), disaccharides (e.g., β-gentiobiose), and alcoholic sugars (e.g., sorbitol) and is able to grow in vitro on minimal media supplemented with either of these nutrients. However, in the hypoxic environment that is found in the “healthy” colon, C. albicans cannot utilize these nutrients. We next found that pre-colonization in a mouse model with a probiotic E. coli significantly reduced C. albicanscolonization, but the mutant E. coli had no effect on colonization. We next showed that Clostridia supplementation restored GI hypoxia and reduced C. albicanscolonization. Remarkably, we found that 5-ASA significantly reduced GI colonization of C. albicans. DISCUSSION/SIGNIFICANCE: We have shown that C. albicans requires oxygen to colonize the GI tract. Importantly, we found that 5-ASA can prevent an antibiotic mediated bloom of C. albicans by restoring GI hypoxia, which warrants additional studies to determine if 5-ASA can be used as an adjunctive prophylactic treatment in high risk patients

Pericytes modulate endothelial inflammatory response during bacterial infection

ABSTRACTPericytes are located around blood vessels, in close contact with endothelial cells. We discovered that pericytes dampen pro-inflammatory endothelial cell responses. Endothelial cells co-cultured with pericytes had markedly reduced expression of adhesion molecules (PECAM-1 and ICAM-1) and proinflammatory cytokines (CCL-2 and IL-6) in response to bacterial stimuli (Brucella ovis, Listeria monocytogenes, or Escherichia coli lipopolysaccharide). Pericyte-depleted mice intraperitoneally inoculated with either B. ovis, a stealthy pathogen that does not trigger detectable inflammation, or Listeria monocytogenes, developed peritonitis. Further, during Citrobacter rodentium infection, pericyte-depleted mice developed severe intestinal inflammation, which was not evident in control mice. The anti-inflammatory effect of pericytes required connexin 43, as either chemical inhibition or silencing of connexin 43 abrogated pericyte-mediated suppression of endothelial inflammatory responses. Our results define a mechanism by which pericytes modulate inflammation during infection, which shifts our understanding of pericyte biology: from a structural cell to a pro-active player in modulating inflammation.IMPORTANCEA previously unknown mechanism by which pericytes modulate inflammation was discovered. The absence of pericytes or blocking interaction between pericytes and endothelium through connexin 43 results in stronger inflammation, which shifts our understanding of pericyte biology, from a structural cell to a player in controlling inflammation

Lesions at the inoculation site of vaccine formulations in female C57BL/6 mice subcutaneously inoculated with γ-irradiated <i>Brucella ovis</i> + alginate/chitosan, γ-irradiated <i>B</i>. <i>ovis</i> + Montanide ISA 61, chitosan–alginate, Montanide ISA 61, or sterile PBS.

(A) γ-irradiated Brucella ovis + alginate/chitosan: skin and subcutaneous tissue with dense infiltrate of plasma cells, lymphocytes and numerous neutrophils surrounded by foamy and epithelioid macrophages (arrows), occasionally forming multinucleated giant cells (inset and arrowheads) associated with an extracellular granular amphophilic material (interpreted as adjuvant). (B) γ-irradiated B. ovis + Montanide ISA 61: pyogranulomatous inflammation with well-defined white spaces of variable sizes consistent with the space left by the adjuvant (*), surrounded by variable numbers of degenerated and viable neutrophils, with aggregates of necrotic debris. (C) alginate/chitosan: mild lymphohistioplasmacytic infiltrate in the subcutaneous tissue (arrow). (D) Montanide ISA 61: pyogranulomatous panniculitis with numerous well-defined white spaces (*). (E) Sterile PBS: no significant histological changes. Hematoxylin and eosin, 10x objective.</p

Fig 4 -

Levels of anti-Brucella ovis (A) IgG1, (B) IgG2b, and (C) IgG3 in sera from female C57BL/6 mice (n = 5) subcutaneously inoculated with γ-irradiated B. ovis + alginate/chitosan, γ-irradiated B. ovis + Montanide ISA 61, alginate/chitosan, Montanide ISA 61, or sterile PBS (non-immunized), and subsequently challenged with wild type B. ovis. Data points represent individual mouse, means and standard deviation are indicated. Data passed normality test prior to ANOVA, and means were compared by Tukey’s test. Significant differences: * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001.</p

Weight gain of female C57BL/6 mice (n = 5) inoculated with γ-irradiated <i>B</i>. <i>ovis</i> + alginate/chitosan, γ-irradiated <i>B</i>. <i>ovis</i> + Montanide ISA 61, chitosan-alginate, Montanide ISA 61, or sterile PBS (non-immunized) during the course of the experiment (56 days).

No statistical difference was observed between the groups. The results were analyzed for normality before being submitted to ANOVA, with the mean values compared by Tukey’s test (p > 0.05). (TIF)</p

Fig 7 -

Spleen of female C57BL/6 mice subcutaneously inoculated with (A) γ-irradiated Brucella ovis + alginate/chitosan, (B) γ-irradiated B. ovis + Montanide ISA 61, (C) alginate/chitosan, (D) Montanide ISA 61, or (E) sterile PBS (non-immunized), subsequently challenged with wild type B. ovis. Microgranulomas (arrows) are observed in all groups, with larger foci of inflammatory cell accumulation in the groups that received only the adjuvants or non-immunized mice. H.E 40x. Inset in E: immunostaining of intralesional Brucella antigens.</p

Raw data generated in this study.

Selection of adjuvant to be combined with the antigen is an extremely important point for formulating effective vaccines. The aim of this study was to evaluate reactogenicity, levels of IgM, IgG and subclasses (IgG1, IgG2b and IgG3), and protection elicited by vaccine formulations with association of chitosan coated alginate or Montanide ISA 61 with γ-irradiated Brucella ovis. The alginate/chitosan biopolymers as well as the Montanide ISA 61 emulsion elicited intense and long-lasting local response, especially when associated with the antigen. However, Montanide ISA 61 induced less intense reactogenicity when compared to alginate/chitosan. Furthermore, γ-irradiated B. ovis with Montanide ISA 61 induced higher levels of IgG2b an important marker of cellular immune response. In conclusion, Montanide ISA 61 resulted in milder reactogenicity when compared to the alginate/chitosan, while it induced a high IgG2b/IgG1 ratio compatible with a Th1 profile response.</div