Brucella Canis Research Articles

Immunological determination of Toxoplasma gondii and Brucella canis in canines from shelters in Risaralda and Caldas, Coffee Region – Colombia

The increasing dog population in Colombia has also raised the incidence of diseases that represent human and animal health risks. Brucella canis is a pathogen that is the primary cause of infertility in canines. It is easily transmitted between canines through body fluids, causing abortions in females, perinatal death of puppies, epididymitis, and infertility in males. On the other hand, Toxoplasma gondii is an easily transmitted parasite; its transmission is the majority between canines and felines, mainly through consuming contaminated food and water, which causes a disease that commonly has a subclinical presentation in canines. However, in immunosuppressed individuals this pathogen can cause neuromuscular, gastrointestinal, and respiratory signs. Currently, due to the increase and geographical distribution of the canine population, it is important to gather information about the prevalence and possible risk factors associated with the presentation of these diseases in the departments of Risaralda and Caldas from Colombia. In this sense, a descriptive cross-sectional study was carried out, and a population of domestic canines was sampled (n=93), females n=63 (67.74%), and males n=30 (32.26%). In total, 72% of animals were positive for Toxoplasma gondii, while for Brucella canis, a prevalence of 0% was estimated.

Canine Brucellosis: A Comprehensive Review

Canine brucellosis, caused by Brucella canis, is a global infectious and zoonotic disease that poses a significant public health risk due to the close interactions between dogs and humans. In dogs, the disease can lead to abortion outbreaks, reproductive failures, lymphadenopathy, and occasionally osteoarticular issues. Asymptomatic infections are also relatively common. In humans, brucellosis typically presents with a febrile illness and non-specific symptoms such as splenomegaly, fatigue, and weakness. The disease is notably problematic in breeding programs due to reproductive failures, including infertility and abortion, leading to substantial economic losses. Transmission occurs through direct contact with infected bodily fluids, particularly during mating, or via contaminated environments. Diagnosing canine brucellosis accurately is critical and can be achieved using various methods, including bacterial cultures, serological tests like the Rose Bengal Plate Test (RBPT) and Enzyme-Linked Immunosorbent Assay (ELISA), and molecular techniques such as polymerase chain reaction (PCR). Treatment is limited, with neutering and antibiotic therapy being the main approaches, though these do not always ensure complete recovery. Preventive measures are essential and include regular screening of breeding dogs, isolation of infected animals, and strict biosecurity protocols. Given its zoonotic potential, it is crucial for veterinary professionals and pet owners to be aware of the disease. Increased awareness and future research on new diagnostic methods and effective vaccines are vital for improving control strategies and reducing the impact of canine brucellosis on both canine and human health.

Brucella canis and Chlamydia spp.: insights into canine infections, diagnostics, and potential tick-borne transmission

Brucella and Chlamydia spp. are zoonotic pathogens with significant implications for both human and animal health. Brucella species, which is responsible for brucellosis, manifest in a range of clinical symptoms and present substantial zoonotic risks. Though less commonly reported, canine infections with Brucella raise concerns about the potential for transmission to humans and highlight the need for continued vigilance in veterinary settings. Chlamydia spp. is notable for its ability to cause diverse diseases in animals, from mild infections to severe systemic illnesses. In dogs, Chlamydia infections can lead to symptoms such as conjunctivitis, respiratory disorders, and reproductive issues, including infertility and abortion. The zoonotic potential of Chlamydia, particularly Chlamydia felis, emphasises the need for thorough monitoring and control measures in both domestic animals and humans. Ticks play a significant role in the transmission of these pathogens. Research has identified Chlamydia spp. in ticks; however, the exact epidemiological implications remain unclear. Similarly, Brucella has been detected in ticks, but conclusive evidence of tick-borne transmission to humans or between animals is still lacking. Improved diagnostic tools and control strategies are essential for managing the risks associated with Brucella and Chlamydia infections in both animals and humans, with a particular focus on the role of ticks as potential vectors.

A New Real-Time Simple Method to Measure the Endogenous Nitrate Reductase Activity (Nar) in Paracoccus denitrificans and Other Denitrifying Bacteria.

The transmembrane nitrate reductase (Nar) is the first enzyme in the dissimilatory alternate anaerobic nitrate respiratory chain in denitrifying bacteria. To date, there has been no real-time method to determine its specific activity embedded in its native membrane; here, we describe such a new method, which is useful with the inside-out membranes of Paracoccus denitrificans and other denitrifying bacteria. This new method takes advantage of the native coupling of the endogenous NADH dehydrogenase or Complex I with the reduction of nitrate by Nar through the quinone pool of the inner membranes of P. denitrificans. This is achieved under previously reached anaerobic conditions. Inner controls confirming the specific Nar activity determined by this new method were made by the total inhibition of the Nar enzyme by sodium azide and cyanide, well-known Nar inhibitors. The estimation of the Michaelis-Menten affinity of Nar for NO3- using this so-called Nar-JJ assay gave a Km of 70.4 μM, similar to previously determined values. This new Nar-JJ assay is a suitable, low-cost, and reproducible method to determine in real-time the endogenous Nar activity not only in P. denitrificans, but in other denitrifying bacteria such as Brucella canis, and potentially in other entero-pathogenic bacteria.

Exposure of American Black Bears (Ursus americanus) to Ticks, Tick-Borne Diseases, and Intestinal Parasites in Wisconsin

We surveyed 159 American black bears (Ursus americanus) over a period of three years for the occurrence of ticks, tick-borne diseases, and intestinal parasites in Wisconsin. We collected blood from the bears to test for the presence of antibodies to Borrelia burgdorferi (Lyme disease), Rickettsia rickettsii (Rocky Mountain spotted fever (RMSF)), Babesia, Ehrlichia, Ehrlichia canis, Brucella canis, and Anaplasma phagocytophilum. We also examined scat samples for intestinal parasites. We commonly found the tick Dermacentor variabilis, but also present the first report of Rhipicephalus sanguineus on black bears. We detected antibodies to Lyme disease and RMSF. We detected antibodies to E. canis for the first time in a bear and both antibodies to R. rickettsii and A. phagocytophilum for the first time in a black bear in Wisconsin. No antibodies for Babesia or Br. canis were detected. We found eggs of the intestinal parasite Baylasascaris transfuga as well as a low number of Toxascara leonina and unknown Capillaria species occurrences in the examined feces.

Development and Application of Colloidal Gold Test Strips for the Rapid Detection of Canine Brucellosis.

Brucellosis is a global problem, with the causative agent being the genus Brucella. B. canis can cause undulant fever in dogs, which is a zoonotic disease that can spread not only among dogs but also to humans. This poses a public health threat to society. In this study, a rapid and straightforward immune colloidal gold test strip was developed for the diagnosis of canine brucellosis through the detection of anti-LPS antibodies in serum samples. Rabbit anti-canine IgG conjugated with colloidal gold was employed as the colloidal gold-labeled antibody. The extracted high-purity R-LPS was employed as the capture antigen in the test line (T-line), while goat anti-rabbit IgG was utilized as the capture antibody in the control line (C-line). The colloidal gold strip exhibited high specificity in the detection of brucellosis, with no cross-reaction observed with the common clinical canine diseases caused by Canine coronavirus (CCV), Canine distemper virus (CDV), and Canine parvovirus (CPV). In comparison to the commercial iELISA kit, the sensitivity and specificity of the colloidal gold test strip were found to be 95.23% and 98.76%, respectively. The diagnostic coincidence rate was 98.47%. The findings of this study indicate that colloidal gold test strips may be employed as a straightforward, expeditious, sensitive, and specific diagnostic instrument for the identification of canine brucellosis, particularly in resource-limited regions.

Transmission of Brucella canis in a canine kennel following introduction of an infected dog

Brucella canis is a zoonotic pathogen and the main causative agent of canine brucellosis. In the Netherlands, B. canis had previously only been detected in individual cases of imported dogs. However, an outbreak of B. canis occurred for the first time in a cohort of autochthonous dogs in a breeding kennel in 2019. The outbreak began with a positive serological test result of an imported intact male dog showing clinical symptoms of brucellosis. Consequently, urine and blood samples were collected and tested positive for B. canis by culture, matrix-assisted laser desorption/ionization – time of flight mass spectrometry (MALDI-TOF MS) and whole-genome-sequencing (WGS). Screening of the contact dogs in the kennel where the index case was kept, revealed that antibodies against B. canis could be detected in 23 out of 69 dogs (34 %) by serum agglutination test (SAT). Of the 23 seropositive dogs, B. canis could be cultured from the urine and/or heparin samples of 19 dogs (83 %). This outbreak represents the first documented case of transmission of B. canis to autochthonous contact dogs in the Netherlands. WGS revealed all B. canis isolates belonged to the same cluster, which means the transmission of B. canis in the breeding kennel was most likely caused by the introduction of one infected dog. Comparing this cluster with data from other B. canis isolates, it also appears that characteristic clusters of B. canis are present in several endemic countries. These clusters seem to remain stable over time and may help in locating the origin of new isolates found. This outbreak showed that the international movement of dogs from endemic countries poses a threat to the canine population, while serological screening and WGS proved to be valuable tools for respectively screening and the epidemiological investigation.

Notes from the Field: Multidisciplinary Approach to Investigating Brucella canis Exposures - South Carolina, September 2023.

Notes from the Field: Multidisciplinary Approach to Investigating Brucella canis Exposures - South Carolina, September 2023.

Causal Agent Investigation and Treatment of Dogs Diagnosed with Discospondylitis in a Brucella canis Endemic Region.

Discospondylitis is a well-recognized disease in dogs, but the relative prevalence of causal infectious agents and efficiency of relevant diagnostic tests are not well-established. Medical record review identified 117 dogs diagnosed with discospondylitis in our clinic over a 5-year period. In 32 dogs, discospondylitis was diagnosed as an incidental imaging finding; 24 of these dogs had concomitant neoplasia. A likely causal infection was identified in 45 of the remaining 85 dogs in which blood and urine cultures, serology for Brucella spp., and galactomannan fungal antigen testing were recommended. Ten dogs were diagnosed with Brucella canis, and ten were diagnosed with suspected fungal infection. Brucella suis serology was negative in all 35 dogs that were tested. Blood cultures were positive in 28 of 71 (39%) tested dogs, and urine culture was positive in 12 of 79 (15%). Cultures were positive from the lesion site of four of eight dogs that underwent surgery and one of the five dogs that underwent image-guided lesion sample collection. Subluxation secondary to discospondylitis was stabilized with metallic implants in four dogs. A similar proportion of known satisfactory treatment outcomes at last follow-up were recorded in dogs that had suspected fungal disease, other bacterial infections, or were Brucella-positive and in those dogs with imaging diagnosis only, although some individuals continued to receive anti-microbial agents or showed recurrent signs. These data support the value of blood culture in discospondylitis and suggest a relatively high prevalence of infection with Brucella spp. and suspected fungal infection.

Production and evaluation of anti-BP26 monoclonal antibodies for the serological detection of animal brucellosis.

Brucella BP26 proves to be a highly immunogenic antigen with excellent specificity in brucellosis detection. In China, the authorized use of the Bp26-deleted vaccine M5ΔBP26 for preventing small ruminant brucellosis highlights the importance of developing accurate detection methods targeting BP26, particularly for the diagnosis of differentiation between infected and vaccinated animals (DIVA). Using the traditional mouse hybridoma technique, we successfully obtained 12 monoclonal antibodies (mAbs) targeting BP26. The efficacy of these mAbs in detecting various animal brucellosis cases using the competitive ELISA method was evaluated. Among them, only the E10 mAb exhibited significant efficiency, being inhibited by 100, 97.62, and 100% of brucellosis-positive sera from cattle, small ruminants, and canines, respectively. The E10-based competitive enzyme-linked immunosorbent assay (cELISA) outperformed the BP26-based indirect enzyme-linked immunosorbent assay (iELISA) in accuracy, particularly for cattle and small ruminant brucellosis, with cELISA sensitivity reaching 97.62% compared to 64.29% for iELISA for small ruminants. Although cELISA showed slightly lower specificity than iELISA, it still maintained high accuracy in canine brucellosis detection. The epitope of mAb E10 was identified in the amino acid sequence QPIYVYPDDKNNLKEPTITGY, suggesting its potential as a diagnostic antigen for brucellosis. In conclusion, the E10-based cELISA presents an effective means of detecting animal brucellosis, particularly significant for DIVA diagnosis in China, where the BP26-mutant vaccine is widely used.

Lessons learned from dealing with the challenge of canine brucellosis in practice.

With more and more dogs being imported to the UK, and no requirement for preimport screening for Brucella canis, veterinary teams are now encountering canine brucellosis on an increasingly regular basis. At BVA Live Mark Moreton and Elizabeth McLennan-Green will reflect on their experiences of developing guidance to help practices manage the risks associated with this zoonotic pathogen.

Brucella canis: a clinical review and rationalising risk

Background: After a letter published by the chief veterinary officer in February 2021 highlighted an increase in the number of positive Brucella canis dogs, the frequency of B canis testing in the UK has increased substantially. To date, roughly 160 positive cases have been reported by the APHA. Amid growing unease, veterinary teams have implemented practice protocols to mitigate risk associated with this non‐endemic, zoonotic infection. Although well‐meaning, blanket policy and inappropriate application of serological tests can negatively impact client and patient welfare while fuelling health anxiety among staff. The combination of increased pet travel, increased popularity of importing dogs and a lack of centralised border requirements for dogs, means B canis is likely to be increasingly encountered and warrants regular, evidence‐based discussion to empower the profession and preserve canine welfare.Aim of the article: This article summarises the clinically relevant issues surrounding Brucella canis, focussing on epidemiology, transmission, human health and safety, clinical signs, diagnosis and treatment. Governmental recommendations and recent risk assessments by the Human Animal Infection and Risk Surveillance group are drawn on where appropriate. Moreover, the article aims to instil confidence in veterinary personnel when rationalising B canis infection risk, and help to ensure that canine and staff health are protected.

One Health approach for Brucella canis: Serological and molecular detection in animal-hoarding individuals and their dogs.

Animal hoarding disorder (AHD) is classified as a psychiatric obsessive-compulsive condition characterized by animal accumulation and often accompanied by unsanitary conditions and animal cruelty. Although AHD may increase pathogen transmission and spread, particularly for zoonotic diseases, human and dog exposure in such cases has yet to be fully established. Accordingly, this study aimed to assess Brucella canis in 19 individuals with AHD (11 households) and their 264 dogs (21 households) in Curitiba, the eighth largest city in Brazil, with approximately 1.8 million habitants. Anti-B. canis antibodies were detected by the 2-mercaptoethanol microplate agglutination test (2ME-MAT) and by a commercial lateral flow immunoassay (LFIA), while molecular detection of previously positive seropositive samples was performed by conventional PCR. Although all the human samples were 2ME-MAT negative, 12/264 (4.5%, 95% Confidence Interval: 2.0-7.0%) dog samples were 2ME-MAT and LFIA positive, with 2ME-MAT titers ranging from 20 to 640. At least one dog in 4/21 (19.0%, 95% CI: 2.0-46.0%) households was seropositive. Despite the absence of seropositivity in individuals with AHD and the comparatively low seroprevalence in dogs, B. canis circulation and outbreaks should be considered in such human populations due to the high burden and recurrent character of B. canis exposure in high-density dog populations and the constant introduction of susceptible animals.

Human exposures to Brucella canis from a pregnant dog during an international flight: Public health risks, diagnostic challenges and future considerations.

This report documents the exposure of passengers and crew of a commercial international flight to the zoonotic pathogen Brucella canis after an infected dog aborted in the passenger cabin of the aircraft. This case demonstrates the challenges associated with brucellosis screening and the risks that airline personnel, airport employees and travellers face when animals with unrecognized zoonotic infections are transported. The public health investigation of this case was conducted by the Centers for Disease Control, the Illinois Department of Health and the Illinois Department of Agriculture, in collaboration with a local veterinary clinic and several academic and federal diagnostic laboratories. It included an extensive diagnostic evaluation of the dam and aborted foetuses to confirm a diagnosis of canine brucellosis. Passengers, airline personnel and staff from the veterinary clinic where the dogs were treated underwent risk assessments, and clinic staff also received detailed guidance regarding infection prevention practices. Animal shelters and breeding programs are recommended to screen dogs routinely for brucellosis, but it is not unusual for domestic or imported animals to have unknown health histories, including the dog's brucellosis status, at the time of purchase, adoption, or re-homing. Testing recommendations and requirements vary by state, making it challenging for state public health and animal health agencies to monitor and respond appropriately. This case highlights the importance of Brucella spp. screening in sexually intact dogs prior to breeding, purchase, or domestic or international transportation of the dogs. The transportation of pregnant dogs may present a previously unrecognized public health threat in addition to contributing to unnecessary stress and health risks for pregnant animals.

Recommendations for vet teams on managing risks around Brucella canis.

Recommendations for vet teams on managing risks around Brucella canis.

A Comprehensive Review of Brucella canis: Zoonotic Risks and Preventive Strategies

Brucella canis, a zoonotic agent, primarily infects dogs and wild Canidae. Infection is notably suspected in dogs exhibiting epididymitis, infertility, or diskospondylitis. Recent reports indicate a growing incidence of Brucella canis infections in dogs, particularly among those imported into the UK from Eastern Europe. Although human infections by B. canis are relatively uncommon, clinical manifestations are typically mild, yet severe cases can potentially lead to septicemia. The disease in humans is incurable and spreads through contact with fluids from infected animals. Various diagnostic protocols, including Real-time PCR, Rapid slide agglutination test (RSAT), and Complement fixation test (CFT), are employed for the diagnosis of canine brucellosis. These serological tests play a crucial role in diagnosing canine brucellosis. Given the potential zoonotic risks, it is imperative to consistently include B. canis in diagnostic algorithms for canine diseases.

Enhancing Therapeutic Efficacy against Brucella canis Infection in a Murine Model Using Rifampicin-Loaded PLGA Nanoparticles.

The in vivo efficacy of rifampicin encapsulated in poly(lactic-co-glycolic acid) (PLGA) nanoparticles was evaluated for the treatment of BALB/c mice experimentally infected with Brucella canis. The PLGA nanoparticles loaded with rifampicin (RNP) were prepared using the single emulsification-solvent evaporation technique, resulting in nanoparticles with a hydrodynamic diameter of 138 ± 6 nm. The zeta potential and polydispersity index values indicated that the system was relatively stable with a narrow size distribution. The release of rifampicin from the nanoparticles was studied in phosphate buffer at pH 7.4 and 37 °C. The release profile showed an initial burst phase, followed by a slower release stage attributed to nanoparticle degradation and relaxation, which continued for approximately 30 days until complete drug release. A combined model of rifampicin release, accounting for both the initial burst and the degradation-relaxation of the nanoparticles, effectively described the experimental data. The efficacy of RNP was studied in vivo; infected mice were treated with free rifampicin at concentrations of 2 mg per kilogram of mice per day (C1) and 4 mg per kilogram of mice per day (C2), as well as equivalent doses of RNP. Administration of four doses of the nanoparticles significantly reduced the B. canis load in the spleen of infected BALB/c mice. RNP demonstrated superior effectiveness compared to the free drug in the spleen, achieving reductions of 85.4 and 49.4%, respectively, when using C1 and 93.3 and 61.8%, respectively, when using C2. These results highlight the improved efficacy of the antibiotic when delivered through nanoparticles in experimentally infected mice. Therefore, the RNP holds promise as a potential alternative for the treatment of B. canis.

The risk of emerging infections in pets

Emerging infections in pets are a worry for many public health professionals, with Brucella canis infection, the tapeworm Echinococcus multilocularis and heartworm Dirofilaria immitis all in the spotlight. The importation of animals is a big risk factor for these conditions, as is the travel of pets abroad with their owners.

Serological and Molecular Survey of Brucella Species in Owners and Their Dogs Living on Island and Mainland Seashore Areas of Brazil.

Background: Although Brucella abortus, Brucella suis, and Brucella canis may infect humans and dogs worldwide, no study to date has assessed and compared owners and their dogs between island and mainland seashore areas. Materials and Methods: Accordingly, the study herein has applied serological tests, including Microplate Agglutination Test with 2-Mercaptoethanol, immunochromatographic assay, and Rose Bengal Test, and a Brucella genus-specific PCR assay to 195 owners and their 148 dogs living on 1 mainland seashore area and three nearby oceanic islands of southern Brazil. Results: No seropositivity to B. abortus and B. suis was detected in owner or dog sera. Anti-B. canis seropositivity was observed in 3/148 (2.0%) dogs, but no owner sample was seropositive to B. canis. In addition, all blood samples from both owners and dogs were negative on Brucella genus-specific PCR assay. Conclusions: The seropositive dogs were not related and lived on the seashore mainland area of Guaraqueçaba city. The absence of seropositivity on the islands and the low seropositivity on the seashore mainland could be attributed to geographic isolation, and suggest the low impact of the disease in the region. Despite being a zoonotic disease, brucellosis by B. canis is not included in the National Program for Control and Eradication of Brucellosis, and its diagnosis and notification are not mandatory. The presence of seropositive dogs highlights the risk to human health and the importance of epidemiological surveillance actions in the region, as well as the need for the implantation of preventive measures to avoid the transmission of the pathogen.

Detección de infección por Brucella canis en perros de raza Pit Bull en Turquía

Brucella canis infection is an often neglected but important zoonotic disease. This study aims to determine its seroprevalence in Pit Bull dogs from the Western Region of the Turkish Anatolian Peninsula. In the Province of Manisa, 2 mL blood samples were taken from the antebrachial region of 35 Pit Bull dogs using sterile K2EDTA (3.6 mg) blood tubes, and the samples were analyzed using both the mercaptoethanol (ME) microagglutination test and B. canis–specific PCR techniques. Of the 35 dogs tested by 2–ME RSAT, 13 (37.14%) tested positive and 22 (63%) tested negative. Of the 13 dogs that tested positive for 2–ME RSAT, 8 (22.85%) were female, and 5 (14.28%) were male. Subsequent PCR analysis of all samples revealed that 7 (20%; 7/35) of the samples that tested positive for 2–ME RSAT were actually B. canis–specific PCR positive. These findings suggest that B. canis is present in Pit Bull dogs, although they provide a general idea of the disease's prevalence of the disease in the region. Multicentre studies with larger numbers of cases in different groups of Pit Bulls, such as healthy, patient and risk groups, are needed to provide comprehensive evidence.