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Archives of Razi Institute Oct 2020Bovine brucellosis is a widespread zoonosis caused by Brucella abortus. The disease is prevalent nationwide in Iran and is on an increasing trend among humans and...
Bovine brucellosis is a widespread zoonosis caused by Brucella abortus. The disease is prevalent nationwide in Iran and is on an increasing trend among humans and livestock. The eradication of brucellosis is challenging and requires control policies at both national and regional levels. Regarding this, the aim of the current study was to evaluate if Brucella is implicated in an abortion outbreak that occurred in a dairy cattle herd, in Shahre Rey, Tehran province, Iran, after vaccination with B. abortus Iriba vaccine. The research context was a dairy cattle farm with 2,000 animals located in Shahre Rey. This farm was Brucella-free based on the results of two serological tests performed one month before vaccination. After the incidence of the first case of abortion following vaccination, serodiagnosis revealed a seropositive reaction in 30 non-pregnant cows and 19 pregnant cows that aborted later. Bacteriology and molecular typing facilitated the identification of 16 isolates of B. abortus biovar 3 from the aborted animals. None of the isolates were confirmed as B. abortus Iribavaccine strain. The results confirmed that B. abortus biovar 3 was the most prevalent biovar in the cattle of Iran. The source and time of infection in the current study were not detected most likely due to the low biosecurity level in the farm (e.g., uncontrolled introduction of the agents via humans, infected animals, semen, and vectors). In endemic countries, the serodiagnosis of brucellosis alone is not sufficient and has to be accompanied by isolation and molecular diagnosis. In addition, it is important to evaluate the presence of B. abortus in bovine semen and vectors.
Topics: Abortion, Veterinary; Animals; Brucella Vaccine; Brucella abortus; Brucellosis, Bovine; Cattle; Cattle Diseases; Dairying; Disease Outbreaks; Immunization; Incidence; Iran
PubMed: 33025778
DOI: 10.22092/ari.2019.125468.1305 -
PLoS Neglected Tropical Diseases May 2019Brucella abortus and B. melitensis have been reported in several studies in animals in Zimbabwe but the extent of the disease remains poorly known. Thus, characterizing...
Brucella abortus and B. melitensis have been reported in several studies in animals in Zimbabwe but the extent of the disease remains poorly known. Thus, characterizing the circulating strains is a critical first step in understanding brucellosis in the country. In this study we used an array of molecular assays including AMOS-PCR, Bruce-ladder, multiple locus variable number tandem repeats analysis (MLVA) and single nucleotide polymorphisms from whole genome sequencing (WGS-SNP) to characterize Brucella isolates to the species, biovar, and individual strain level. Sixteen Brucella strains isolated in Zimbabwe at the Central Veterinary laboratory from various hosts were characterized using all or some of these assays. The strains were identified as B. ovis, B. abortus, B. canis and B. suis, with B. canis being the first report of this species in Zimbabwe. Zimbabwean strains identified as B. suis and B. abortus were further characterized with whole genome sequencing and were closely related to reference strains 1330 and 86/8/59, respectively. We demonstrate the range of different tests that can be performed from simple assays that can be run in laboratories lacking sophisticated instrumentation to whole genome analyses that currently require substantial expertise and infrastructure often not available in the developing world.
Topics: Animals; Brucella abortus; Brucella melitensis; Brucellosis; Cattle; Cattle Diseases; Genome, Bacterial; Genotype; Minisatellite Repeats; Phylogeny; Sheep; Sheep Diseases; Swine; Swine Diseases; Zimbabwe
PubMed: 31107864
DOI: 10.1371/journal.pntd.0007311 -
Molecules and Cells Jul 2021A recent genetic study with revealed the secretion activator gene A (SagA) as an autolysin component creating pores in the peptidoglycan (PGN) layer for the type IV...
A recent genetic study with revealed the secretion activator gene A (SagA) as an autolysin component creating pores in the peptidoglycan (PGN) layer for the type IV secretion system (T4SS) and peptidoglycan hydrolase inhibitor A (PhiA) as an inhibitor of SagA. In this study, we determined the crystal structures of both SagA and PhiA. Notably, the SagA structure contained a PGN fragment in a space between the N- and C-terminal domains, showing the substrate-dependent hinge motion of the domains. The purified SagA fully hydrolyzed the meso-diaminopimelic acid (DAP)-type PGN, showing a higher activity than hen egg-white lysozyme. The PhiA protein exhibiting tetrameric assembly failed to inhibit SagA activity in our experiments. Our findings provide implications for the molecular basis of the SagA-PhiA system of . The development of inhibitors of SagA would further contribute to controlling brucellosis by attenuating the function of T4SS, the major virulence factor of .
Topics: Animals; Brucella abortus; Models, Molecular; N-Acetylmuramoyl-L-alanine Amidase; Type IV Secretion Systems
PubMed: 34112742
DOI: 10.14348/molcells.2021.0011 -
Microbes and Infection 2021The objective of this project was to conduct a feasibility study to determine whether the Brucella abortus S19 vaccine infects and persists in mice and determine whether...
The objective of this project was to conduct a feasibility study to determine whether the Brucella abortus S19 vaccine infects and persists in mice and determine whether S19 can be used as a challenge strain for vaccine trial studies. Groups of BALB/c mice were inoculated (intraperitoneally, subcutaneously, intranasally) and euthanized to determine colonization titers in the spleens and lungs. This study showed that S19 does infect and persist in the tissues of mice for 8 weeks and demonstrates that S19 can be used, safely and economically under BSL2 containment, as the challenge strain for future trials to evaluate vaccine efficacy.
Topics: Animals; Brucella abortus; Brucellosis; Disease Models, Animal; Female; Mice; Mice, Inbred BALB C; Specific Pathogen-Free Organisms
PubMed: 33753207
DOI: 10.1016/j.micinf.2021.104809 -
Microbiology (Reading, England) May 2005The essential mechanisms and virulence factors enabling Brucella species to survive and replicate inside host macrophages are not fully understood. The authors...
The essential mechanisms and virulence factors enabling Brucella species to survive and replicate inside host macrophages are not fully understood. The authors previously reported that a putative guanosine 5'-diphosphate 3'-diphosphate (ppGpp) mutant (spoT mutant) of Brucella abortus failed to replicate in HeLa cells. The present study showed that the pattern of surface proteins and morphological change of the spoT mutant were different from B. abortus wild-type. B. abortus wild-type changed its morphology upon treatment with ppGpp synthetase I activation inhibitor. In various tests under stress conditions, including nutrient starvation, nitric oxide resistance, acid resistance and antibiotic resistance, the spoT mutant had a lower stress resistance than B. abortus wild-type. Although the spoT mutant has the same smooth phenotype and LPS profile as B. abortus wild-type, it had a higher rate of adherence to macrophages but lower internalization and intracellular replication within macrophages. The spoT mutant did not co-localize with either late endosomes or lysosomes and was almost cleared from the spleens of mice after 10 days, without splenomegaly. RT-PCR was used to detect spoT mRNA from around 10(6) cells incubated in low-pH enriched medium; it showed that the expression of spoT increased after 30 min incubation. The data suggest that SpoT does not contribute to intracellular trafficking of B. abortus, but contributes to the maintenance of bacterial morphology and the physiological adaptation required for intracellular replication.
Topics: Animals; Anti-Bacterial Agents; Bacterial Proteins; Brucella abortus; Brucellosis; Female; Gene Deletion; Guanosine Tetraphosphate; Heat-Shock Response; Humans; Ligases; Macrophages; Mice; Mice, Inbred BALB C; Microbial Sensitivity Tests; Virulence
PubMed: 15870469
DOI: 10.1099/mic.0.27782-0 -
International Journal of Molecular... Apr 2016Brucellosis is a debilitating zoonotic disease that affects humans and animals. The diagnosis of brucellosis is challenging, as accurate species level identification is...
Brucellosis is a debilitating zoonotic disease that affects humans and animals. The diagnosis of brucellosis is challenging, as accurate species level identification is not possible with any of the currently available serology-based diagnostic methods. The present study aimed at identifying Brucella (B.) species-specific proteins from the closely related species B. abortus and B. melitensis using sera collected from naturally infected host species. Unlike earlier reported investigations with either laboratory-grown species or vaccine strains, in the present study, field strains were utilized for analysis. The label-free quantitative proteomic analysis of the naturally isolated strains of these two closely related species revealed 402 differentially expressed proteins, among which 63 and 103 proteins were found exclusively in the whole cell extracts of B. abortus and B. melitensis field strains, respectively. The sera from four different naturally infected host species, i.e., cattle, buffalo, sheep, and goat were applied to identify the immune-binding protein spots present in the whole protein extracts from the isolated B. abortus and B. melitensis field strains and resolved on two-dimensional gel electrophoresis. Comprehensive analysis revealed that 25 proteins of B. abortus and 20 proteins of B. melitensis were distinctly immunoreactive. Dihydrodipicolinate synthase, glyceraldehyde-3-phosphate dehydrogenase and lactate/malate dehydrogenase from B. abortus, amino acid ABC transporter substrate-binding protein from B. melitensis and fumarylacetoacetate hydrolase from both species were reactive with the sera of all the tested naturally infected host species. The identified proteins could be used for the design of serological assays capable of detecting pan-Brucella, B. abortus- and B. melitensis-specific antibodies.
Topics: Animals; Antibodies; Antigens, Bacterial; Bacterial Proteins; Blotting, Western; Brucella abortus; Brucella melitensis; Brucellosis, Bovine; Cattle; Chromatography, High Pressure Liquid; Electrophoresis, Gel, Two-Dimensional; Glyceraldehyde-3-Phosphate Dehydrogenases; Hydro-Lyases; Proteome; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
PubMed: 27144565
DOI: 10.3390/ijms17050659 -
Microbes and Infection May 2008Smooth Brucella abortus S2308 is virulent while rough derivatives are attenuated. Intracellular killing is often blamed for these differences. In the studies described,...
Smooth Brucella abortus S2308 is virulent while rough derivatives are attenuated. Intracellular killing is often blamed for these differences. In the studies described, uptake kinetics and interaction of S2308 and S2308 manBA::Tn5 (CA180) rough mutants with macrophages were investigated. The results revealed that smooth B. abortus was rapidly internalized, achieving a maximum level in less than 5 min without additional uptake over the next 30 min. In contrast, continued uptake of the rough mutant was observed and only achieves a maximum level after 30 min. The results were confirmed by the differences in F-actin polymerization, lipid raft staining, early endosome colocalization and electron microscopic observations after smooth and rough Brucella infection. We also demonstrated for the first time that uptake of S2308, but not rough mutant CA180 was PI3-kinase and toll-like receptor 4 (TLR4) dependent. Differences in uptake were associated with differences in macrophage activation with regard to NF-kappaB translocation and cytokine production. These results provide evidence that the presence of B. abortus OPS dictates the interactions between Brucella and specific cell surface receptors minimizing macrophage activation and enhancing Brucella survival and/or persistence.
Topics: Animals; Brucella abortus; Brucellosis; Cell Line; Macrophage Activation; Macrophages; Mice; NF-kappa B; Receptors, Cell Surface; Toll-Like Receptor 4
PubMed: 18457975
DOI: 10.1016/j.micinf.2008.01.005 -
Brazilian Journal of Microbiology :... Jan 2019Canine brucellosis is an infectious disease that produces reproductive disease in both males and females. Although Brucella canis is more common, the infection by...
Canine brucellosis is an infectious disease that produces reproductive disease in both males and females. Although Brucella canis is more common, the infection by Brucella abortus is more frequent in dogs sharing habitats with livestock and wild animals. We decided to investigate the role of dogs in the maintenance of Brucella spp. in the Pantanal wetland. Serum and whole blood samples were collected from 167 dogs. To detect antibodies against B. abortus and B. canis, buffered acidified plate antigen (BAPA) and agar gel immunodiffusion (AGID) tests were performed. To detect Brucella spp., B. abortus and B. canis DNA, PCR was performed using the bcsp31, BruAb2_0168, and BR00953 genes, respectively. To confirm the PCR results, three bcsp31 PCR products were sequenced and compared with sequences deposited in GenBank. The seropositivity rates of 7.8% and 9% were observed for the AGID and BAPA tests, respectively. Positivity rates of 45.5% and 10.8% were observed when testing bcsp31 and BruAb2_0168, respectively, while there was no positivity for BR00953. The sequenced products had 110 base pairs that aligned with 100% identity to B. abortus, B. canis, and B. suis. Considering our results, dogs may be acting as maintenance hosts of Brucella spp. in the Pantanal region.
Topics: Animals; Bacterial Proteins; Brucella abortus; Brucella canis; Brucellosis; Dog Diseases; Dogs; Female; Male; Wetlands
PubMed: 30637651
DOI: 10.1007/s42770-018-0006-5 -
Brazilian Journal of Microbiology :... Dec 2020Brucellosis and tuberculosis are diseases of great economic impact in cattle herds and are controlled by governmental programs in many countries. The validation of a...
Brucellosis and tuberculosis are diseases of great economic impact in cattle herds and are controlled by governmental programs in many countries. The validation of a diagnostic technique is fundamental for its application in official control programs of these diseases. The aim of the present study was to validate a polymerase chain reaction in real time (qPCR) for detection of Mycobacterium bovis and Brucella abortus in samples of artificially contaminated raw milk. The technique was evaluated using tests of analytical sensitivity and specificity, repeatability, internal reproducibility, and robustness. Initially, five DNA extraction methodologies were tested, and the DNeasy Mericon Food Kit-Qiagen and the Maxwell® 16 Tissue DNA Purification Kit-Promega presented the best analytical specificity of all the commercial kits tested and were used exclusively in subsequent tests. The lowest limits of detection obtained in the qPCR were 2.3 pg for M. bovis DNA and 20.7 fg for B. abortus DNA. The repeatability and reproducibility associated with the robustness indicate that the evaluated methods are applicable as rapid tools for the official in vivo diagnosis of bovine tuberculosis and brucellosis in raw milk from dairy herds in Brazil.
Topics: Animals; Brazil; Brucella abortus; Brucellosis; Cattle; DNA, Bacterial; Female; Limit of Detection; Milk; Mycobacterium bovis; Raw Foods; Real-Time Polymerase Chain Reaction; Reproducibility of Results; Sensitivity and Specificity; Tuberculosis, Bovine
PubMed: 32572837
DOI: 10.1007/s42770-020-00319-9 -
Revue Scientifique Et Technique... Sep 1993Three therapeutic regimens were evaluated in 121 cows naturally infected with Brucella melitensis or Brucella abortus, using a combination of long-acting oxytetracycline...
Three therapeutic regimens were evaluated in 121 cows naturally infected with Brucella melitensis or Brucella abortus, using a combination of long-acting oxytetracycline (LA-OTC), streptomycin (ST) and OTC-intramammary infusion (IMI). Cessation of shedding of Brucella in udder secretions and absence of Brucella in selected tissues were considered criteria for successful treatment. Regimen A (tested on 35 cows) consisted of LA-OTC 25 mg/kg administered intramuscularly (i.m.) every 3 days for 42 days, ST 25 mg/kg i.m. daily for 8 days, and OTC-IMI 20 ml/teat daily for 4 days. Regimen B (tested on 53 cows) was similar to regimen A, except that ST was administered every 2 days for 16 days and OTC-IMI every 2 days for 8 days. Both regimens were equally effective in eliminating Brucella organisms from all cows involved in the tests and no relapses were recorded. However, regimen C, which was similar to regimen A, except that ST was administered every 3 days for 24 days and OTC-IMI every 3 days for 12 days, resulted in the elimination of Brucella organisms from only 30 (91%) of 33 cows. Before commencement of the therapeutic regimens, B. melitensis biovar 1 or 2 had been repeatedly isolated from udder secretions of 103 cows and B. abortus biovar 1 from mammary secretions of 18 cows.
Topics: Abortion, Veterinary; Agglutination Tests; Animals; Antibodies, Bacterial; Brucella abortus; Brucella melitensis; Brucellosis, Bovine; Cattle; Costs and Cost Analysis; Delayed-Action Preparations; Female; Infusions, Parenteral; Injections, Intramuscular; Mammary Glands, Animal; Oxytetracycline; Pregnancy; Pregnancy Complications, Infectious; Reproduction; Streptomycin
PubMed: 8219341
DOI: 10.20506/rst.12.3.729