Presumptive Identification of Smooth Brucella Strain Antibodies in Canines

Brucellosis is a zoonotic disease caused by a Gram-negative coccobacillus. There are four Brucella strains of zoonotic importance in our domestic species, subdivided by their culture phenotypes: Brucella abortus (B. abortus), B. melitensis, B. suis (smooth strains) and B. canis (rough strain). Dogs can serve as hosts for all four of the zoonotic strains; however, routine serologic testing in dogs has been limited to the identification of B. canis antibodies. The aim of our study was to identify smooth Brucella strain antibodies in canines. We hypothesize that the Brucella abortus Fluorescence Polarization Assay would be successful in identifying smooth Brucella strain antibodies in canines. Ninety-five dogs, including forty-five hog hunting dogs were screened for circulating antibodies to any of the four zoonotic strains of the bacteria utilizing a combination of Canine Brucella Slide Agglutination Test (CBSA), Brucella canis Agar Gel Immunodiffusion II test (AGIDII), Brucella abortus Card Agglutination Test (BCA), and the Brucella abortus Fluorescence Polarization Assay (FPA). Test interpretation results yielded a 0% (0/95) smooth Brucella strain seropositivity rate, with 2% (2/95) of dogs yielding inconclusive rough Brucella strain serology results (0–2% rough strain seropositivity rate). Additionally, a retrospective portion of the study was performed to identify sera containing circulating antibodies to any of the smooth strains of Brucella by testing previously banked canine serum samples stored at Cornell's Veterinary Diagnostic Laboratory from 2018 to 2019 via Brucella abortus FPA. Of the 769 serum samples tested, 13/769 (1.7%) yielded an inconclusive result, 725/769 (94.2%) were negative, 30/769 (4%) yielded a positive FPA test result, and 1/769 (0.1%) had to be excluded due to insufficient sample remaining to perform the diagnostic test. Of the 30 FPA positive canine serum samples, 97% (29/30) also tested positive on the CBSA test. Additionally, there was a statistically significant (p < 0.0001) likelihood of altered (spayed/neutered) and mixed breed dogs to be FPA positive when compared to intact, purebred dogs, respectively.

Loss of the virulence plasmid by Shigella sonnei promotes its interactions with CD207 and CD209 receptors

Introduction. Shigella sonnei, the cause of bacillary dysentery, belongs to Gram-negative enteropathogenic bacteria. S. sonnei contains a 210 kb virulence plasmid that encodes an O-antigen gene cluster of LPSs. However, this virulence plasmid is frequently lost during replication. It is well-documented that after losing the O-antigen and becoming rough strains, the Gram-negative bacteria may express an LPS core on its surface. Previous studies have suggested that by using the LPS core, Gram-negative bacteria can interact with several C-type lectin receptors that are expressed on antigen-presenting cells (APCs). Hypothesis/Gap Statement. S. sonnei by losing the virulence plasmid may hijack APCs via the interactions of LPS-CD209/CD207. Aim. This study aimed to investigate if the S. sonnei rough strain, by losing the virulence plasmid, interacted with APCs that express C-type lectins of human CD207, human CD209a and mouse CD209b. Methodology. SDS-PAGE silver staining was used to examine the O-antigen expression of S. sonnei WT and its rough strain. Invasion assays and inhibition assays were used to examine the ability of S. sonnei WT and its rough strain to invade APCs and investigate whether CD209 and CD207 are receptors for phagocytosis of rough S. sonnei . Animal assays were used to observe the dissemination of S. sonnei . Results. S. sonnei did not express O-antigens after losing the virulence plasmid. The S. sonnei rough strain invades with APCs, including human dendritic cells (DCs) and mouse macrophages. CD209 and CD207 are receptors for phagocytosis of rough S. sonnei . Expression of the O-antigen reduces the ability of the S. sonnei rough strain to be disseminated to mesenteric lymph nodes and spleens. Conclusion. This work demonstrated that S. sonnei rough strains – by losing the virulence plasmid – invaded APCs through interactions with CD209 and CD207 receptors.

Identification of Canine Brucellosis in Three Province, Ethiopia

Background: In Ethiopia, brucellosis has been reported targeted on bovine, occasionally on shoat, and rarely on camels. An investigation of the disease Brucellosis in the neglected companion animals is scared in Ethiopia. The objective of this study was to identify canine brucellosis in Batu town, Alage and Naka village through cross sectional approaches. A total of 389 serum samples (207 from Batu, 107 from Alage, and 75 from Naka) were collected by restraining dogs with a portable and safe modified dog crush, invented by this author. Blood samples were collected from ear vein and sera were screened for Brucella antibodies using different serological tests. RBPT prepared from the smooth strain B. abortus antigen and CFT was used as a screening test and confirmatory test, respectively. Furthermore, all sera samples had also screened by RBPTcanis antigen (rough strain); and those positive were considered the cause for B. canis infection. Results: Using RBPT smooth strains, 21(5.4%; CI: 3.35, 7.96) were positive and 19(4.88%; CI: 2.7, 7.0) were confirmed by CFT. Besides, 34 (8.74%; CI: 5.92, 11.56) were positive for RBPTcanis rough strains. Relatively, higher proportion of anti B. canis antibodies had seen in Batu (11.59%) followed by Alage (5.61%), and Naka (5.33%). Sex, living condition, and history of obstetrical problem were significantly associated with the occurrence of canine brucellosis (p< 0.05). Odd of canine brucellosis due to smooth and rough strains in outdoor dogs were 4.72 and 6.42 times higher compared with indoors, respectively. This is true the fact that outdoors had a chance of getting infected aborted wastes when roaming freely. Conclusion: This study suggests that canine brucellosis is prevalent in the province. The seropositivity could give an insight that, the awareness of the people toward the disease was also the gap in the study area. Hence, this warrants public education among the community is recommended.

Sodium Polyphosphate and Polyethylenimine Enhance the Antimicrobial Activities of Plant Essential Oils

<p>Plant extracts have been used for millennia for treatment of disease, with much recent interest focusing on the antimicrobial activities of plant essential oils (EOs). Although EOs are active against common microbial pathogens, their effective use as topical, environmental or food antimicrobials will require EO-based formulations with enhanced antimicrobial activities. In the present study, two polyionic compounds, sodium polyphosphate (polyP, a polyanion) and polyethylenimine (PEI, a polycation), were evaluated for their abilities to enhance the antimicrobial activities of six EOs against the human pathogens <em>Escherichia coli</em> O157:H7, <em>Salmonella enterica</em> subsp. <em>enterica </em>ser Minnesota, <em>Pseudomonas aeruginosa</em>, <em>Listeria monocytogenes</em>, <em>Staphylococcus aureus </em>and <em>Candida albicans</em>. EOs tested were cinnamon, clove, regular and redistilled oregano and two types of thyme oil. EOs were examined via disk diffusion and broth microdilution, either alone or in the presence of sub-inhibitory levels of polyP or PEI. Both polyP and PEI were found to be effective enhancers of EO activity against all strains examined, and calculation of fractional inhibitory indices for select EO/organism pairings demonstrated that true synergy was possible with this enhancement approach. Experiments with a deep rough strain of S. Minnesota probed the role of the outer membrane in both intrinsic resistance to EOs and enhancement by polyions. The use of polyP and PEI for boosting the antimicrobial activities of EOs may eventually facilitate the development of more effective EO-based antimicrobial treatments for use in applications such as wound treatment, surface disinfection, or as GRAS antimicrobials for use in foods or on food contact surfaces.</p>

Complete Genome Sequence ofAggregatibacter actinomycetemcomitansStrain IDH781

We report here the complete genomic sequence and methylome ofAggregatibacter actinomycetemcomitansstrain IDH781. This rough strain is used extensively as a model organism to characterize localized aggressive periodontitis pathogenesis, the basic biology and oral cavity colonization ofA. actinomycetemcomitans, and its interactions with other members of the oral microbiome.

Characterization of Outer Membrane Vesicles fromBrucella melitensisand Protection Induced in Mice

The outer membrane vesicles (OMVs) from smoothB. melitensis16 M and a derived rough mutant, VTRM1 strain, were purified and characterized with respect to protein content and induction of immune responses in mice. Proteomic analysis showed 29 proteins present in OMVs fromB. melitensis16 M; some of them are well-knownBrucellaimmunogens such as SOD, GroES, Omp31, Omp25, Omp19, bp26, and Omp16. OMVs from a rough VTRM1 induced significantly higher expression of IL-12, TNFα, and IFNγ genes in bone marrow dendritic cells than OMVs from smooth strain 16 M. Relative to saline control group, mice immunized intramuscularly with rough and smooth OMVs were protected from challenge with virulent strainB. melitensis16 M just as well as the group immunized with live strainB. melitensisRev1 (P<0.005). Additionally, the levels of serum IgG2a increased in mice vaccinated with OMVs from rough strain VTRM1 consistent with the induction of cell-mediated immunity.

A live vaccine from Brucella abortus strain 82 for control of cattle brucellosis in the Russian Federation

During the first half of the twentieth century, widespread regulatory efforts to control cattle brucellosis due to Brucella abortus in the Union of Soviet Socialist Republics were essentially non-existent, and control was limited to selective test and slaughter of serologic agglutination reactors. By the 1950s, 2–3 million cattle were being vaccinated annually with the strain 19 vaccine, but because this vaccine induced strong, long-term titers on agglutination tests that interfered with identification of cattle infected with field strains of B. abortus, its use in cattle was discontinued in 1970. Soviet scientists then began a comprehensive program of research to identify vaccines with high immunogenicity, weak responses on agglutination tests and low pathogenicity in humans, as a foundation for widespread control of cattle brucellosis. While several new vaccines that induced weak or no responses on serologic agglutination tests were identified by experiments in guinea pigs and cattle, a large body of experimental and field studies suggested that the smooth–rough strain SR82 vaccine combined the desired weak agglutination test responses with comparatively higher efficacy against brucellosis. In 1974, prior to widespread use of strain SR82 vaccine, over 5300 cattle farms across the Russian Federation were known to be infected with B. abortus. By January 2008, only 68 cattle farms in 18 regions were known to be infected with B. abortus, and strain SR82 continues to be the most widely and successfully used vaccine in many regions of the Russian Federation.