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PloS One 2019Canine brucellosis, caused by Brucella canis, is a disease of dogs and represents a public health concern as it can be transmitted to humans. Canine brucellosis is on...
Canine brucellosis, caused by Brucella canis, is a disease of dogs and represents a public health concern as it can be transmitted to humans. Canine brucellosis is on the rise in the United States and there is currently no vaccine for use in dogs. Mice have been extensively utilized to investigate host-pathogen interactions and vaccine candidates for smooth Brucella species and could serve a similar role for studying B. canis. However, comparatively little is known about B. canis infection in mice. The objective of this study was to characterize the kinetics of colonization and pathogenicity of B. canis in mice in order to evaluate the mouse as a model for studying this pathogen. C57BL/6 mice were inoculated intraperitoneally with 105, 107, or 109 CFU of Brucella canis RM6/66 and euthanized 1-, 2-, 4-, 6-, 9-, and 12-weeks post-inoculation. B. canis induced splenomegaly in mice infected with 109 CFU at 1- and 2 weeks post-inoculation while no gross lesions were observed in other dose groups. Infection at the two higher doses resulted in dose-dependent granulomatous hepatitis and histiocytic infiltration of the spleen and mesenteric lymph nodes by 1-2 weeks. B. canis was cultured from the liver, spleen, uterus, bone marrow, lung, and kidney in all groups with colonization declining at a slow but steady rate throughout the experiment. Clearance was achieved by 9 weeks 105 CFU group and by 12 weeks in the 107 CFU group, while B. canis persisted in the spleen until 12 weeks in the highest dose group. Although B. canis does not demonstrate significant replication in C57BL/6 mice, it has the ability to establish an infection, induce splenomegaly, and persist for several weeks in multiple organs. Moreover, 1 x 107 CFU appears to be a suitable challenge dose for investigating vaccine safety.
Topics: Animals; Brucella canis; Brucellosis; Disease Progression; Female; Kinetics; Mice; Mice, Inbred C57BL; Rodent Diseases
PubMed: 31220185
DOI: 10.1371/journal.pone.0218809 -
Emerging Infectious Diseases Jul 2021Brucella canis had not been isolated in the Netherlands until November 2016, when it was isolated from a dog imported from Romania. Including this case, 16 suspected... (Review)
Review
Brucella canis had not been isolated in the Netherlands until November 2016, when it was isolated from a dog imported from Romania. Including this case, 16 suspected cases were notified to the authorities during the following 25 months. Of these 16 dogs, 10 were seropositive; tracking investigations found another 8 seropositive littermates. All seropositive animals were rescue dogs imported from Eastern Europe. B. canis was cultured from urine, blood, and other specimens collected from the dogs. Genotyping of isolates revealed clustering by litter and country. Isolating B. canis in urine indicates that shedding should be considered when assessing the risk for zoonotic transmission. This case series proves introduction of B. canis into a country to which it is not endemic through import of infected dogs from B. canis-endemic areas, posing a threat to the naive autochthonous dog population and humans.
Topics: Animals; Brucella canis; Brucellosis; Dog Diseases; Dogs; Europe, Eastern; Netherlands; Romania
PubMed: 34152959
DOI: 10.3201/eid2707.201238 -
Frontiers in Veterinary Science 2017is a pathogenic bacterium that causes brucellosis in dogs, and its zoonotic potential has been increasing in recent years. is a rare source of human brucellosis in...
BACKGROUND
is a pathogenic bacterium that causes brucellosis in dogs, and its zoonotic potential has been increasing in recent years. is a rare source of human brucellosis in China, where has been the major pathogen associated with human brucellosis outbreaks. In late 2011, a case of a infection was detected in a human patient in Zhejiang Province, China. To compare the genotypes between strains of isolated from the patient and from dogs, a multiple-locus variable-number tandem-repeat analysis (MLVA-16) was performed. In addition, the lipopolysaccharide-synthesis-related genes were analyzed with the reference strain RM6/66.
RESULTS
32 strains were divided into 26 genotypes using MLVA-16 [Hunter-Gaston Diversity Index (HGDI) = 0.976]. The HGDI indexes for various loci ranged between 0.000 and 0.865. All four Hangzhou isolates were indistinguishable using panel 1 (genotype 3) and panel 2A (genotype 28). However, these strains were distinctly different from other isolates from Beijing, Jiangsu, Liaoning, and Inner Mongolia at Bruce 09. The emergence of a human infection was limited to an area. Comparative analysis indicated from canines and humans have no differences in lipopolysaccharide-synthesis locus.
CONCLUSION
The comprehensive approaches have been used to analyze human and canine isolates, including molecular epidemiological and LPS genetic characteristics. Further detailed analysis of the whole genomic sequencing will contribute to understanding of the pathogenicity of in humans.
PubMed: 29326956
DOI: 10.3389/fvets.2017.00223 -
The Tohoku Journal of Experimental... Apr 2023The incidence of Brucella canis (B. canis) in humans is unknown in Northern Cyprus. In this study, we investigated the prevalence of B. canis and Brucella abortus (B....
The incidence of Brucella canis (B. canis) in humans is unknown in Northern Cyprus. In this study, we investigated the prevalence of B. canis and Brucella abortus (B. abortus) infection in human sera and evaluated the results obtained by agglutination-based techniques using standardized antigens made from B. canis comparatively. All of the subjects were negative in terms of Rose-Bengal plate test. Undiluted serum samples were initially screened by rapid slide agglutination test (RSAT), and those which were found positive were retested in the dilution of 1/25-1/200. Confirmation of the positive results was performed by using 2-mercaptoethanol standard agglutination test (SAT). The test antigen was prepared from the less mucoid M (-) variant of B. canis, and 1/1,048 titered dog antiserum was used as positive control. In 225 serum samples, 3.6% (8/225) was positive by B. canis M (-) RSAT, 4.4 % (10/225) was positive by B. canis M (-) indirect enzyme-linked immunosorbent assay (iELISA). 5.3% (12/225) was positive by B. abortus S99 RSAT and 9.8% (22/225) was positive by B. abortus S99 iELISA. Nine samples were positive by both B. abortus S99 RSAT and B. abortus S99 iELISA. Seven samples were positive by both B. canis M (-) RSAT and B. canis M (-) iELISA. One patient was positive by all methods. It is important to evaluate patient samples with RSAT and iELISA. Until the notification system gives better results to the Ministry of Health, in order to reach the real data for Northern Cyprus, multicenter prevalence determination studies should be done for future.
Topics: Humans; Animals; Dogs; Brucella canis; Brucella abortus; Brucellosis; Cyprus; Antigens, Bacterial; Antibodies, Bacterial; Enzyme-Linked Immunosorbent Assay; Agglutination Tests
PubMed: 36384858
DOI: 10.1620/tjem.2022.J096 -
Veterinary Medicine and Science Jul 2021Brucellosis is an infectious zoonotic bacterial disease of humans and other animals. In the Republic of South Africa (RSA), animal brucellosis is widespread and the...
BACKGROUND
Brucellosis is an infectious zoonotic bacterial disease of humans and other animals. In the Republic of South Africa (RSA), animal brucellosis is widespread and the current available data on the prevalence of this disease rely solely on serological testing. The primary limitation of brucellosis serology is the lack of discriminatory powers to differentiate between Brucella species and biovars as well as the cross-reactivity observed with other Gram-negative bacteria.
AIM
The aim of this study was to conduct a retrospective laboratory-based survey on Brucella species and biovars isolated from various animal species in SA between 2008 and 2018.
MATERIAL AND METHODS
The isolation of Brucella species and biovar typing was performed using conventional microbiological techniques.
RESULTS AND DISCUSSION
A total of 963 strains of Brucella species were included in this study with a frequency of detection for B. abortus (n = 883; 91.6%) followed by B. melitensis (n = 42; 4.4%), B. ovis (n = 29; 3.0%) and B. canis (n = 9; 0.9%). Of the 883 strains of B. abortus, 90.1% were typed as B. abortus biovar-1 while 5.7% as B. abortus biovar-2, and 3.3% and 0.5% were B. abortus S19 and B. abortus RB51 vaccine strains, respectively. Among the 42 B. melitensis strains, 71.4% were reported as B. melitensis biovar-1 and 26.2% as B. melitensis biovar-3 while 2.4% was B. melitensis biovar-2.
CONCLUSION
A retrospective study, such as this one, provides useful information that can be critical in formulating policies and strategies for the control and eradication of brucellosis in animal populations in RSA.
Topics: Animals; Animals, Wild; Brucella abortus; Brucella canis; Brucella melitensis; Brucella ovis; Brucellosis; Cattle; Cattle Diseases; Dog Diseases; Dogs; Goat Diseases; Goats; Prevalence; Retrospective Studies; Sheep; Sheep Diseases; Sheep, Domestic; South Africa
PubMed: 33974356
DOI: 10.1002/vms3.483 -
Frontiers in Veterinary Science 2021The transcriptional regulator MucR is related to normal growth, stress responses and virulence, and affects the expression of various virulence-related genes in...
The transcriptional regulator MucR is related to normal growth, stress responses and virulence, and affects the expression of various virulence-related genes in smooth-type strains. However, the function of MucR in the rough-type remains unknown. In this study, we discovered that MucR protein was involved in resistance to heat stress, iron-limitation, and various antibiotics in . . In addition, the expression level of various bacterial flagellum-related genes was altered in mutant strain. Deletion of this transcriptional regulator in significantly affected virulence in RAW264.7 macrophage and mice infection model. To gain insight into the genetic basis for distinctive phenotypic properties exhibited by mutant strain, RNA-seq was performed and the result showed that various genes involved in translation, ribosomal structure and biogenesis, signal transduction mechanisms, energy production, and conversion were significantly differently expressed in Δ strain. Overall, these studies have not only discovered the phenotype of mutant strain but also preliminarily uncovered the molecular mechanism between the transcriptional regulator MucR, stress response and bacterial virulence in . .
PubMed: 34250056
DOI: 10.3389/fvets.2021.650942 -
Scientific Reports May 2018Brucella canis infection is an underdiagnosed zoonotic disease. Knowledge about perinatal brucellosis in dogs is extremely limited, although foetuses and neonates are...
Brucella canis infection is an underdiagnosed zoonotic disease. Knowledge about perinatal brucellosis in dogs is extremely limited, although foetuses and neonates are under risk of infection due to vertical transmission. In this study, immunohistochemistry was used to determine tissue distribution and cell tropism of B. canis in canine foetuses and neonates. Diagnosis of B. canis in tissues of naturally infected pups was based on PCR and sequencing of amplicons, bacterial isolation, and immunohistochemistry, whose specificity was confirmed by laser capture microdissection. PCR positivity among 200 puppies was 21%, and nine isolates of B. canis were obtained. Tissues from 13 PCR-positive puppies (4 stillborn and 9 neonates) presented widespread immunolabeling. Stomach, intestines, kidney, nervous system, and umbilicus were positive in all animals tested. Other frequently infected organs included the liver (92%), lungs (85%), lymph nodes (69%), and spleen (62%). Immunolabeled coccobacilli occurred mostly in macrophages, but they were also observed in erythrocytes, epithelial cells of gastrointestinal mucosa, renal tubules, epidermis, adipocytes, choroid plexus, ependyma, neuroblasts, blood vessels endothelium, muscle cells, and in the intestinal lumen. These results largely expand our knowledge about perinatal brucellosis in the dog, clearly demonstrating a pantropic distribution of B. canis in naturally infected foetuses and neonates.
Topics: Animals; Animals, Newborn; Brazil; Brucella canis; Brucellosis; Dog Diseases; Dogs; Female; Fetus; Laser Capture Microdissection; Liver; Lung; Lymph Nodes; Macrophages; Male; Polymerase Chain Reaction; Spleen; Tropism; Zoonoses
PubMed: 29740101
DOI: 10.1038/s41598-018-25651-x -
PloS One 2020Vaccination is the most important tool for controlling brucellosis, but currently there is no vaccine available for canine brucellosis, which is a zoonotic disease of...
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.
Topics: ATP-Binding Cassette Transporters; Alginates; Animals; Antibody Formation; Brucella Vaccine; Brucella canis; Brucella ovis; Brucellosis; Dog Diseases; Dogs; Female; Immunization; Liver; Lymphocytes; Macrophages; Male; Mice; Mice, Inbred BALB C; Mutation; Sheep
PubMed: 32298378
DOI: 10.1371/journal.pone.0231893 -
Internal Medicine (Tokyo, Japan) 2019Human brucellosis, one of the most common zoonoses worldwide, rarely occurs in Japan, and only a few chronic cases have been reported. We herein report the case of a...
Human brucellosis, one of the most common zoonoses worldwide, rarely occurs in Japan, and only a few chronic cases have been reported. We herein report the case of a 39-year-old Japanese woman with chronic human brucellosis, considered a Brucella canis infection, that persisted for 19 years. Her medical history and fever pattern suggested chronic brucellosis, and the diagnosis was made based on the results of a serum tube agglutination test (SAT). After undergoing combination therapy with streptomycin and doxycycline, she achieved symptomatic relief and showed negative SAT results. Even in non-endemic areas, chronic brucellosis is an important differential diagnosis in patients with long-term persistent fatigue or a fever.
Topics: Administration, Oral; Adult; Animals; Anti-Bacterial Agents; Brucella canis; Brucellosis; Chronic Disease; Diagnosis, Differential; Doxycycline; Drug Therapy, Combination; Fatigue; Female; Fever; Humans; Injections, Intramuscular; Japan; Streptomycin; Zoonoses
PubMed: 31685787
DOI: 10.2169/internalmedicine.2961-19 -
Acta Crystallographica. Section F,... Jan 2022Members of the bacterial genus Brucella cause brucellosis, a zoonotic disease that affects both livestock and wildlife. Brucella are category B infectious agents that...
Members of the bacterial genus Brucella cause brucellosis, a zoonotic disease that affects both livestock and wildlife. Brucella are category B infectious agents that can be aerosolized for biological warfare. As part of the structural genomics studies at the Seattle Structural Genomics Center for Infectious Disease (SSGCID), FolM alternative dihydrofolate reductases 1 from Brucella suis and Brucella canis were produced and their structures are reported. The enzymes share ∼95% sequence identity but have less than 33% sequence identity to other homologues with known structure. The structures are prototypical NADPH-dependent short-chain reductases that share their highest tertiary-structural similarity with protozoan pteridine reductases, which are being investigated for rational therapeutic development.
Topics: Brucella canis; Brucella suis; Brucellosis; Crystallography, X-Ray; Humans; Tetrahydrofolate Dehydrogenase
PubMed: 34981773
DOI: 10.1107/S2053230X21013078