A novel approach for detection of brucella using a real-time recombinase polymerase amplification assay

Ultrasensitive and highly specific detection of the Brucella genus and B. melitensis by CRISPR/Cas12b-multiple cross displacement amplification technique

Brucellosis is caused by members of the Brucella spp. and remains one of the world's major zoonotic diseases. Brucella melitensis (B. melitensis) as the most contagious Brucella species cannot be ignored as an essential source of infection for brucellosis, especially in countries/regions dominated by animal husbandry. Thus, the identification of the Brucella genus and B. melitensis is crucial for rapid diagnosis of brucellosis to control disease transmission and clinical treatment. Here, we developed the CRISPR/Cas12b nuclease combined with a multiple cross displacement amplification (MCDA) assay (CRISPR-MCDA) for highly specific and sensitive detection of Brucella genus and B. melitensis in clinical applications. Two sets of specific primers were designed targeting the specific gene of Brucella genus (Bcsp31) and B. melitensis (BMEII0466), respectively. The CRISPR-MCDA assay showed high specificity and sensitivity in 28 non-Brucella isolates and 64 clinical samples. The detection limit of CRISPR-MCDA assay was 2 copies/μL in the plasmid dilution template, and the whole detection process took within 90 minutes with nanoparticle-based lateral flow biosensor (LFB) to validate experimental results. Taken together, the CRISPR-MCDA-LFB assay is a visual, sensitive, and highly specific detection technique that can be used as an attractive potential identification tool for Brucella genus and B. melitensis.IMPORTANCEThe prevention and control of Brucellosis urgently require rapid and accurate diagnostic methods. This work validates a new method for the simultaneous detection of Brucella genus and B. melitensis. The method can effectively reduce the chances of contamination and provides a more rapid, sensitive, and specific on-site detection of Brucella. It also offers a solution for the rapid screening of Brucellosis in resource-limited environments, which is crucial for effective disease prevention and control. This technology can also be widely applied to the rapid detection of other pathogens beyond Brucella.

Establishment of a rapid method for the detection of Brucella canis based on recombinase-mediated thermostable nucleic acid amplification technology

Objective

To establish a rapid detection method for canine brucellosis using recombinase-aided amplification (RAA) technology.

Methods

The outer membrane protein 25 gene fragment (Omp25) of Brucella canis was targeted. Primers and fluorescent probes were designed and synthesized, and recombinant plasmids were constructed as standards. The RAA assay was optimized by screening primers and establishing a fluorescent reaction system. Sensitivity was analyzed using plasmid standards with varying copy numbers. Specificity was tested using genomes from Brucella canis, Brucella suis, Brucella melitensis, Brucella abortus, Staphylococcus aureus, pathogenic Escherichia coli, Salmonella enteritidis, Shigella spp., Proteus mirabilis, and Listeria monocytogenes. Reproducibility was evaluated using plasmid standards from the same and different batches.

Results

The optimized RAA system used primers bOmp25-F2/bOmp25-R2 and probe bOmp25-P, with a constant reaction temperature of 39°C for 15 minutes. The detection sensitivity was 1 copy/μL. No cross-reaction was observed with other Brucella species or pathogenic bacteria, indicating high specificity. Intra-batch variability was below 1.00%, and inter-batch variability was below 2.00%. The positive detection coincidence rate of RAA was significantly higher than that of commercial real-time fluorescence quantitative PCR (100% VS 86.96%, P<0.05).

Conclusion

The RAA-based rapid detection method for Brucella canis is suitable for clinical rapid testing. It offers advantages such as quick detection, high sensitivity, strong specificity, and good reproducibility. This method provides new insights for the rapid detection of canine brucellosis and the precise diagnosis of other pet diseases, making it suitable for promotion and application.

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.

Evidence-practice gap analysis in the role of tick in brucellosis transmission: a scoping review

BACKGROUND

Brucellosis is a zoonotic affliction instigated by bacteria belonging to the genus Brucella and is characterized by a diverse range of pervasiveness, multiple transmission routes, and serious hazards. It is imperative to amalgamate the current knowledge and identify gaps pertaining to the role of ticks in brucellosis transmission.

METHODS

We systematically searched China National Knowledge Infrastructure (CNKI), WanFang, Google Scholar, and PubMed on the topic published until April 23, 2022. The procedure was performed in accordance with the Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines. The selected articles were categorized across three major topic areas, and the potential data was extracted to describe evidence-practice gaps by two reviewers.

RESULTS

The search identified 83 eligible studies for the final analyses. The results highlighted the potential capacity of ticks in brucellosis transmission as evidenced by the detection of Brucella in 16 different tick species. The pooled overall prevalence of Brucella in ticks was 33.87% (range: 0.00-87.80%). The review also revealed the capability of Brucella to circulate in parasitic ticks' different developmental stages, thus posing a potential threat to animal and human health. Empirical evidence from in vitro rodent infection experiments has revealed that ticks possess the capability to transmit Brucella to uninfected animals (range: 45.00-80.00%). Moreover, significant epidemiological associations have been found between the occurrence of brucellosis in animals and tick control in rangelands, which further suggests that ticks may serve as potential vectors for brucellosis transmission in ruminants. Notably, a mere three cases of human brucellosis resulting from potential tick bites were identified in search of global clinical case reports from 1963 to 2019.

CONCLUSIONS

It is imperative to improve the techniques used to identify Brucella in ticks, particularly by developing a novel, efficient, precise approach that can be applied in a field setting. Furthermore, due to the lack of adequate evidence of tick-borne brucellosis, it is essential to integrate various disciplines, including experimental animal science, epidemiology, molecular genetics, and others, to better understand the efficacy of tick-borne brucellosis. By amalgamating multiple disciplines, we can enhance our comprehension and proficiency in tackling tick-borne brucellosis.

Development of a novel visual isothermal amplification assay for rapid detection of Brucella spp

Brucellosis is an economically important livestock disease worldwide besides having a noteworthy impact on human health. In this study, a rapid, simple, and ultra-sensitive nuclei-acid diagnostic technique was developed for the detection of brucellosis harnessing saltatory rolling circle amplification (SRCA). The diagnostic method was developed using World Organization for Animal Health (WOAH) approved primers targeting the bcsp31 gene of the Brucella genome. The assay can be accomplished within 90 min at a temperature of 65 °C without the requirement of sophisticated instrumentation. The result interpretation can be done with the naked eye with the aid of SYBR green dye. The developed technique displayed 100% specificity by amplifying only 10 reference and field strains of Brucella spp. and there was no cross-reactivity with the other tested pathogens. The lower limit of detections of SRCA and end-point PCR assays were 9.7 fg/μL (2.7 genome copies of Brucella) and 970 fg/μL, respectively. Thus, the developed SRCA assay was found to be 100× more sensitive than the end-point PCR assay. To the best of our knowledge, our study is the first one to develop an SRCA-based assay for the detection of brucellosis and it can be a diagnostic tool for resource-constrained laboratories and veterinary hospitals.

One Health Paradigm to Confront Zoonotic Health Threats: A Pakistan Prospective

The emergence and re-emergence of zoonotic diseases significantly impact human health, particularly those who live in impoverished areas and have close contact with domestic or wild animals. Nearly 75% of zoonotic diseases are transmitted directly from animals to humans or indirectly via vector/agent interactions between animals and humans. Growing populations, globalization, urbanization, and the interaction of the environment with humans and livestock all play roles in the emergence and spread of zoonotic diseases. "One Health" is a multidisciplinary concept aimed at improving human, animal, and environmental health, but this concept is not widely accepted in developing countries. In Pakistan, environmental, human, and animal health are severely affected due to a lack of sufficient resources. This review article provides an overview of the most common zoonotic diseases found in Pakistan and emphasizes the importance of the "One Health" concept in managing these diseases. Given the current situation, interdisciplinary research efforts are required to implement and sustain effective and long-term control measures in animal, human, and environmental health surveillance and accurate diagnostic methods.

Point of care diagnostics and non-invasive sampling strategy: a review on major advances in veterinary diagnostics

The use of point of care diagnostics (POCD) in animal diseases has steadily increased over the years since its introduction. Its potential application to diagnose infectious diseases in remote and resource limited settings have made it an ideal diagnostic in animal disease diagnosis and surveillance. The rapid increase in incidence of emerging infectious diseases requires urgent attention where POCD could be indispensable tools for immediate detection and early warning of a potential pathogen. The advantages of being rapid, easily affordable and the ability to diagnose an infectious disease on spot has driven an intense effort to refine and build on the existing technologies to generate advanced POCD with incremental improvements in analytical performance to diagnose a broad spectrum of animal diseases. The rural communities in developing countries are invariably affected by the burden of infectious animal diseases due to limited access to diagnostics and animal health personnel. Besides, the alarming trend of emerging and transboundary diseases with pathogen spill-overs at livestock-wildlife interfaces has been identified as a threat to the domestic population and wildlife conservation. Under such circumstances, POCD coupled with non-invasive sampling techniques could be successfully deployed at field level without the use of sophisticated laboratory infrastructures. This review illustrates the current and prospective POCD for existing and emerging animal diseases, the status of non-invasive sampling strategies for animal diseases, and the tremendous potential of POCD to uplift the status of global animal health care.

Bovine brucellosis - a comprehensive review

Brucellosis is a zoonotic disease of great animal welfare and economic implications worldwide known since ancient times. The emergence of brucellosis in new areas as well as transmission of brucellosis from wild and domestic animals is of great significance in terms of new epidemiological dimensions. Brucellosis poses a major public health threat by the consumption of non-pasteurized milk and milk products produced by unhygienic dairy farms in endemic areas. Regular and meticulous surveillance is essentially required to determine the true picture of brucellosis especially in areas with continuous high prevalence. Additionally, international migration of humans, animals and trade of animal products has created a challenge for disease spread and diagnosis in non-endemic areas. Isolation and identification remain the gold standard test, which requires expertise. The advancement in diagnostic strategies coupled with screening of newly introduced animals is warranted to control the disease. Of note, the diagnostic value of miRNAs for appropriate detection of B. abortus infection has been shown. The most widely used vaccine strains to protect against Brucella infection and related abortions in cattle are strain 19 and RB51. Moreover, it is very important to note that no vaccine, which is highly protective, safe and effective is available either for bovines or human beings. Research results encourage the use of bacteriophage lysates in treatment of bovine brucellosis. One Health approach can aid in control of this disease, both in animals and man.