First Isolation and Multilocus Sequence Typing of Brucella canis from a Subclinically Infected Pet Dog in China

Canine brucellosis, a worldwide zoonotic disease, is mainly caused by Brucella canis. In the present study, we isolated a Brucella strain (CD3) from a subclinically infected pet dog in Sichuan Province, Southwestern China. Classical biotyping methods and molecular biological tests (BCSP31 and BcSS PCR) proved that the strain belonged to B. canis. Furthermore, B. canis CD3 and another two B. canis strains (WJ5 and YA4), which were all isolated from pet dogs in Sichuan, were genotyped using multilocus sequence typing (MLST). Our results showed that the three B. canis strains were identified as the same sequence type (ST21). The present study is the first to report B. canis strain from a subclinically infected pet dog in China, indicating a potential threat to public health posed by subclinical infections in pet dogs. We suggest that screening for B. canis should be incorporated into routine medical examination of pet dogs and other companion animals in areas with a history of animal or human brucellosis.

Epidemiological investigation for brucellosis in dogs of Thrissur

India is endemic to bovine brucellosis, and there is a high potential for transmission of disease from ruminants to dogs. A total of 18 bitches belonging to five different breeds at different stage of abortion (30 days to 65 days of gestation) were selected for this study. Majority of them were showing abortion (88.89 per cent) at 45 to 65 days of the gestation. Microscopic examination of Stamp stained smear obtained from the aborted foetal stomach contents revealed red coccobacillary organisms suggestive of Brucella spp.in three cases. RBPT on paired sera samples on day of presentation and three weeks after abortion showed agglutination within four minutes in five out of 18 female dogs. DNA extracted from the aborted tissues of a RBPT positive Labrador dog yielded amplicons of 193 base pair specific for Brucella spp. on PCR. The results obtained from this study stress the need for screening dogs for canine brucellosis in the current brucellosis surveillance and control programmes.

Comparison of BP26, Omp25 and Omp31 and a Multi-Epitope Based Fusion Protein in Serological Detection of Canine Brucellosis

Background Brucellosis is one of the most important zoonotic diseases in the world. Canine brucellosis caused mainly by B. canis is seriously neglected and there is lack of accurate diagnostic tools. Methods In this study, using 34 brucellosis positive dog sera and 62 negative control sera, the Brucella outer membrane protein of Omp31, BP26, Omp25 and a multi-epitope based fusion protein were evaluated by iELISA for their potential use as antigens in serological diagnosis for canine brucellosis. Results The result showed that multi-epitope based fusion protein performed best in distinguishing brucellosis positive and negative dog sera, with positive predictive value (PPV) was 100% and the negative predictive value (NPV) was 98.41%. BP26 and Omp31 showed excellent sensitivity in detecting brucellosis positive dog sera, but their cross reaction to sera infected with Vibrio parahaemolyticus and Listeria monocytogenes may hinder their application as diagnostic reagent. While Omp25 was lack of sufficient sensitivity and just showed limited ability in distinguishing positive and negative dog sera. Conclusion The multi-epitope based fusion protein could accelerate the development of diagnostic kit for canine brucellosis currently urgently needed in China.

A New Specific Sequence to Distinguish B.canis From Other Brucella by PCR

Background: Brucellosis is a zoonotic disease worldwide. The increasing number of pet dogs has raised new risk of people getting canine brucella with absent or mild symptom. Besides, the canine brucellosis can be caused by other brucella species, so their infection could be omitted by the PCR method. The present PCR methods can only detect canine brucella, by which cases infected with other brucella would appear negative. It’s an urge to develop a specific PCR assay for detecting canine Brucellosis, Whether the pathogen was B.canis or any other Brucella.Resaults: a differential sequence of B.canis were found by genome comparison analysis and were analyzed by BLAST. Then a PCR method was established using specific primers in the sequence and tested for clinical application. It could detect canine brucellosis caused by B.canis or other Brucella species with 310-bp and 413-bp product, respectively. The developed PCR method had specificity for non-brucella and a sensitivity of 100 copies of Brucella DNA. The detection accuracy verified with spiked samples was 95.5% (21/22) for B.canis and 100% (22/22) for other brucella. Conclusions: The study found a specific sequence of B.canis and developed a PCR detection method to detect canine brucellosis caused by B.canis or other Brucella species. The method established in this study will more comprehensively detect the pathogen of canine brucellosis and provide important methods and means for preventing and controlling this disease.

Canine Brucellosis: An Update

Canine brucellosis is an infectious and zoonotic disease caused by Brucella canis, which has been reported worldwide, and is a major public health concern due to close contact between dogs and humans. In dogs, canine brucellosis manifests with abortion outbreaks, reproductive failure, enlargement of lymph nodes, and occasionally affects the osteoarticular system, although the occurrence of asymptomatic infections in dogs are not uncommon. In humans, the disease is associated with a febrile syndrome, commonly with non-specific symptoms including splenomegaly, fatigue, and weakness. Infection of dogs occurs mostly by the oronasal route when in contact with contaminated tissues such as aborted fetuses, semen, urine, and vaginal secretions. In humans, contact with contaminated fluids from infected dogs is an important source of infection, and it is an occupational risk for veterinarians, breeders, laboratory workers, among other professionals who deal with infected animals or biological samples. The diagnosis in dogs is largely based on serologic methods. However, serologic diagnosis of canine brucellosis remains very challenging due to the low accuracy of available tests. Molecular diagnostic methods have been increasingly used in the past few years. Treatment of infected dogs is associated with a high frequency of relapse, and should be employed only in selected cases. Currently there are no commercially available vaccines for prevention of canine brucellosis. Therefore, development of novel and improved diagnostic methods as well as the development of efficacious and safe vaccination protocols are needed for an effective control of canine brucellosis and its associated zoonotic risk.

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.

First report of Canine brucellosis in Ukraine: Pathogen isolation and characterization

For the first time in Ukraine we confirmed canine brucellosis caused by Brucella canis. The bacterium was isolated from testicles of three-year-old male Labrador retriever with orchitis and epididymitis. Initially blood serum sample was positive in cCFT, AGID and LFIA. In addition to the pathogen isolation and identification by biochemical test and PCR, the antimicrobial susceptibility test was performed that showed sensitive of B. canis to the commonly used antibiotics, which should be taken into account for the further therapy

Prevalence and Genomic Characterization of Brucella canis Strains Isolated from Kennels, Household, and Stray Dogs in Chile

Canine brucellosis caused by Brucella canis is a zoonotic disease that causes reproductive alterations in dogs, such as infertility, abortion, and epididymitis. This pathogen is especially prevalent in South America, and due to the lack of official control programs and the growing trend of adopting dogs it constitutes a public health risk that must be addressed. The aim of this study was to determine the prevalence of B. canis infection in kennel, shelter, and household dogs and to characterize the genomic properties of circulating strains, including ure and virB operons and omp25/31 genes. Samples from 771 dogs were obtained, and the infection was detected by blood culture and/or serology in 7.0% of the animals. The complete ure and virB operons and the omp25/31 genes were detected. Interestingly, we found different single-nucleotide polymorphisms (SNPs) in some of the analyzed genes, which could mean a change in the fitness or virulence of these strains. This study provides further evidence about dogs as a source of B. canis strains that can infect people. This also highlights the need to implement official control programs, including the mandatory testing of dogs, especially stray dogs, before adoption.

MALDI-TOF MS and genomic analysis can make the difference in the clarification of canine brucellosis outbreaks

Brucellosis is one of the most common bacterial zoonoses worldwide affecting not only livestock and wildlife but also pets. Canine brucellosis is characterized by reproductive failure in dogs. Human Brucella canis infections are rarely reported but probably underestimated due to insufficient diagnostic surveillance. To improve diagnostics, we investigated dogs in a breeding kennel that showed clinical manifestations of brucellosis and revealed positive blood cultures. As an alternative to the time-consuming and hazardous classical identification procedures, a newly developed species-specific intact-cell matrix-assisted laser desorption/ionization–time of flight mass spectrometry analysis was applied, which allowed for rapid identification of B. canis and differentiation from closely related B. suis biovar 1. High-throughput sequencing and comparative genomics using single nucleotide polymorphism analysis clustered our isolates together with canine and human strains from various Central and South American countries in a distinct sub-lineage. Hence, molecular epidemiology clearly defined the outbreak cluster and demonstrated the endemic situation in South America. Our study illustrates that MALDI-TOF MS analysis using a validated in-house reference database facilitates rapid B. canis identification at species level. Additional whole genome sequencing provides more detailed outbreak information and leads to a deeper understanding of the epidemiology of canine brucellosis.