Brucella suis S2, Brucella melitensis Rev. 1 and Brucella abortus S19 living vaccines: residual virulence and immunity induced against three Brucella species challenge strains in mice

Iron is a fundamental element required by most organisms, including Brucella. Several researchers have suggested that the iron response regulator (irr) and rhizobial iron regulator (rirA) genes regulate iron acquisition by Brucella abortus, influencing heme synthesis by and virulence of this pathogen. However, little is known about another Brucella species, Brucella melitensis. In this research, we successfully constructed two mutants: M5-90Δirr and M5-90ΔrirA. The adhesion, invasion, and intracellular survivability of these two mutants were evaluated in RAW264.7 cells infected with 1 × 106 CFU of M5-90Δirr, M5-90ΔrirA, or M5-90. We also tested the sensitivity of cells to hydrogen peroxide and their ability to grow. In addition, the virulence of these two mutants was evaluated in BALB/c mice. The results showed that the ability of these two mutants to invade and adhere inside the murine macrophages RAW264.7 was attenuated but their ability to replicate intracellularly was strengthened, enhancing the resistance to hydrogen peroxide. The M5-90Δirr mutant showed stronger growth ability than the parental strain under iron-limiting conditions. No differences were observed in the number of bacteria in spleen between M5-90 and M5-90Δirr at 7 or 15 days postinfection. However, the number of M5-90ΔrirA in spleen reduced significantly at 15 days postinfection. The splenic index of the M5-90Δirr group is evidently lower than that of M5-90. This is the first report that irr and rirA genes of B. melitensis are associated not only with virulence but also with growth ability. Together, our data suggest that M5-90Δirr is a promising Brucella vaccine candidate.

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MALDI-TOF identification of Brucella melitensis, Brucella abortus and Brucella suis

10.26226/morressier.56d5ba2dd462b80296c94f5e ◽

2016 ◽

Author(s):

Michela Sali

Keyword(s):

Brucella Abortus ◽

Brucella Melitensis ◽

Maldi Tof ◽

Brucella Suis

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A repA-based ELISA for discriminating cattle vaccinated with Brucella suis 2 from those naturally infected with Brucella abortus and Brucella melitensis

Molecular and Cellular Probes ◽

10.1016/j.mcp.2014.06.002 ◽

2014 ◽

Vol 28 (5-6) ◽

pp. 251-254 ◽

Cited By ~ 1

Author(s):

Jing-Yu Wang ◽

Ning Wu ◽

Wan-Hua Liu ◽

Juan-Juan Ren ◽

Pan Tang ◽

...

Keyword(s):

Brucella Abortus ◽

Brucella Melitensis ◽

Brucella Suis

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Phages-Adsorption -Test for Differentiation of Genus: Brucella

Zeitschrift für Naturforschung B ◽

10.1515/znb-1965-1216 ◽

1965 ◽

Vol 20 (12) ◽

pp. 1249-1252

Author(s):

Józef Parnas ◽

Stefania Zalichta

Keyword(s):

Brucella Abortus ◽

Brucella Melitensis ◽

S Phase ◽

Point Of View ◽

Brucella Suis ◽

Specific Receptors

Brucella-phages-adsorption test on killed (70°) cells of all types of Brucella in the pure “S” phase has orientating value for determination of the Genus: “Brucella”.Brucella abortus “S” strains are in 100% positive in this test. Brucella melitensis “S” strains are in 83% positive and in 17% weakly positive.Brucella suis “S” strains are in 100% positive.Brucella atypica “S” strains are mostly positive. All types of Brucella in “R” phase are negative in this test. This experiment is important from point of view of general systematics of bacteria and for the explanation of phage-specific receptors in the “S” and “R” phase.

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Seroprevalence and Molecular Identification of Brucella spp. in Camels in Egypt

Microorganisms ◽

10.3390/microorganisms8071035 ◽

2020 ◽

Vol 8 (7) ◽

pp. 1035 ◽

Cited By ~ 1

Author(s):

Aman Ullah Khan ◽

Ashraf E. Sayour ◽

Falk Melzer ◽

Sherif Abdel Ghafar Elsayed El-Soally ◽

Mandy C. Elschner ◽

...

Keyword(s):

Complement Fixation Test ◽

Indirect Elisa ◽

Complement Fixation ◽

Brucella Melitensis ◽

Control Strategies ◽

Effective Control ◽

Brucella Species ◽

Serum Samples ◽

Brucella Suis ◽

The Rose

Brucellosis is one of the most important worldwide zoonoses of many countries including Egypt. Camel brucellosis has not gained much attention in Egypt yet. This study is focused on the three governorates with the highest camel populations and the largest camel markets in the country to determine the disease seroprevalence and identify the Brucella species in local camel holdings. In total, 381 serum samples were collected from male and female camels from Giza, Aswan, and Al-Bahr Al-Ahmar (the Red Sea) governorates. Samples were serologically examined using the Rose–Bengal plate test (RBPT), indirect ELISA (i-ELISA), competitive ELISA (c-ELISA) and complement fixation test (CFT). Brucella antibodies were detected in 59 (15.5%), 87 (22.8%), 77 (20.2%) and 118 (31.0%) of sera by RBPT, i-ELISA, c-ELISA and CFT, respectively. Using real-time PCR, Brucella DNA was amplified in 32 (8.4%) seropositive samples including Brucella abortus (25/32), Brucella suis (5/32) and Brucella melitensis (2/32), defining a complex epidemiological status. To the best of our knowledge, this is the first study reporting Brucella suis DNA in camel serum. The risk-associated factors including age, sex, breed and geographical distribution were statistically analyzed, showing non-significant association with seroprevalence. The results of this study will raise awareness for camel brucellosis and help develop effective control strategies.

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