A “One Health” surveillance and control of brucellosis in developing countries: Moving away from improvisation

The "One Health" approach in the face of Covid-19: how radical should it be?

BACKGROUND

The 2020-2021 coronavirus (Covid-19) pandemic is just the latest epidemic event that requires us to rethink and change our understanding of health. Health should no longer be conceived only in relation to human beings, but in unitary terms, as a dimension that connects humans, animals, plants, and the environment (holistic view, One Health). In general, alterations occurring in this articulated chain of life trigger a domino effect.

METHODOLOGY

In this paper, we review the One Health paradigm in the light of the Covid-19 pandemic and distinguish two approaches within it that might be dubbed the Prudent one and the Radical one. Each approach is structured in three levels - epistemological, medical, and ethical.

RESULTS

In this way, we show how we humans can better address the pandemic today and how, in the future, we can treat the whole living system better, by renouncing our anthropocentric perspective on health.

CONCLUSION

We hold that the Prudent approach can be very helpful, and we discuss the medical and ethical issues related to it. We also consider the Radical view and the epistemological turn it requires compared to the Prudent one.

Use of a Participatory Method for Community-Based Brucellosis Control Design in Agro-Pastoral Areas in Tanzania

Brucellosis is widespread in both humans and livestock in many developing countries. The authors have performed a series of epidemiological studies on brucellosis in agro-pastoral areas in Tanzania since 2015, with the aim of the disease control. Previously, the potential of a community-based brucellosis control initiative, which mainly consisted of the sale of cattle with experience of abortion and vaccinating calves, was assessed as being effective and acceptable based on a quantitative approach. This study was conducted to investigate the feasibility of community-based brucellosis control program using participatory rural appraisals (PRAs) and key-informant interviews. Four PRAs were performed together with livestock farmers and livestock and medical officers in 2017. In the PRAs, qualitative information related to risky behaviors for human infection, human brucellosis symptoms, willingness to sell cattle with experience of abortion, and willingness to pay for calf vaccination were collected, and a holistic approach for a community-based disease control project was planned. All of the communities were willing to implement disease control measures. To avoid human infection, education, especially for children, was proposed to change risky behaviors. The findings of this study showed that community-based disease control measures are promising.

Crystal structures of FolM alternative dihydrofolate reductase 1 from Brucella suis and Brucella canis

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.

Importance of brucellosis control programs of livestock on the improvement of one health

Brucellosis not only represents an important health restraint on livestock but also causes high economic losses in many developing countries worldwide. Despite considerable efforts made for the control of brucellosis, the disease is still spreading in many regions (such as the Middle East) where it represents one of the most important health hazards impacting both animals and humans. The present review aims to investigate the efficacy of veterinary control programs regarding brucellosis, with a special focus on current prevention, control, and eradication approaches. The reasons for unsuccessful control programs such as the absence of highly effective vaccines and non-certified bulls are also debated, to understand why the prevalence of brucellosis in livestock is not decreasing in many areas despite considerable efforts taken to date. The importance of governmental and regional investment in brucellosis control remains one of the main limiting factors owing to the limited budget allocated to tackle this disease. In this context, one health concept has generated novel comprehensive approaches with multiple economic implications across the livestock industry and public health. However, the implementation of such global preventive strategies appears to be a key issue for many endemic and low-income countries. According to the collected data, epidemiological contexts including management and trade systems along with well-defined agro-ecological zones should be evaluated in brucellosis endemic countries to improve milk production and to enhance the sustainability of the livestock sector at both national and regional levels.

Bovine Brucellosis in Gauteng, South Africa: Seroprevalence amongst Cattle Handlers and Variables Associated with Seropositive Cattle Herds, 2014-2016

In South Africa, the prevalence of cattle handler exposure to Brucella on cattle farms is unknown and risk factors and cattle symptoms associated with infected cattle herds are unavailable. To address this gap, a case-control study of cattle herds was conducted in Gauteng province and farm workers and veterinary officials were tested for exposure to Brucella. Seroprevalence amongst farm workers exposed to case herds ranged from 4.0% (BrucellaCapt®) to 16.7% (IgG ELISA®), compared to those exposed to control herds, where seroprevalence ranged from 1.9% (BrucellaCapt®) to 5.7% (IgG ELISA®). Seroprevalence amongst veterinary officials was significantly greater compared to farm workers exposed to case herds for the outcome RBT+ IgM- IgG+ (OR = 11.1, 95% CI: 2.5-49.9, p = 0.002) and RBT- IgM- IgG+ (OR = 6.3, 95% CI: 2.3-17.3, p < 0.001). Risk factors associated with being an infected herd were: being a government-sponsored farm vs. private farm (OR 4.0; 95% CI: 1.4-11.3; p = 0.009), beef vs. dairy herd (OR 7.9; 95% CI: 1.4-44.9; p = 0.020), open vs. closed herd (OR 3.3; 95% CI: 1.1-10.4; p = 0.038) and the presence of antelope on the farm (OR 29.4; 95% CI: 4.0-218.2; p = 0.001). Abortions (OR = 5.1; 95% CI: 2.0-13.3; p < 0.001), weak calves in the herd (OR = 8.0; 95% CI: 2.6-24.4; p < 0.001), reduction in number of calves born (OR = 9.0; 95% CI: 2.1-43.6; p < 0.001), reduction in conception rate (OR = 3.9; 95% CI: 0.8-18.3; p = 0.046), hygromas in cattle (p = 0.011) and farmers reporting brucellosis-like symptoms in their farm workers or in him/herself (OR = 3.4; 95% CI: 1.3-8.7; p = 0.006) were more likely to be associated with Brucella infected herds than control herds. This evidence can be used in strategic planning to protect both human and herd health.

Knowledge of Brucellosis, Health-Seeking Behaviour, and Risk Factors for Brucella Infection amongst Workers on Cattle Farms in Gauteng, South Africa

Brucellosis in humans is under-detected and underreported in sub-Saharan Africa. Risk factors associated with Brucella infection and health seeking behaviour in response to brucellosis-like symptoms, amongst cattle farm workers and veterinary officials in South Africa, are unknown. Farm workers and veterinary officials (N = 230) were screened for brucellosis using commercial Rose Bengal Test (RBT^®), IgM Enzyme-linked Immunoassay (ELISA)^®, IgG ELISA^® and the BrucellaCapt^® test. Knowledge of brucellosis and risk factors for exposure to Brucella were also investigated. Seroprevalence varied according to test used: 10.1% (RBT^®), 20.9% (IgG ELISA^®) and 6.5% (BrucellaCapt^®). Only 22.2% (6/27) of veterinary officials opt to visit a clinic, doctor, or hospital in response to self-experienced brucellosis-like symptoms, compared to 74.9% (152/203) of farm workers (p < 0.001). Of the BrucellaCapt^® seropositive participants, 53% (7/15) did not visit a clinic in response to brucellosis-like symptoms. Weak evidence of an association between the handling of afterbirth or placenta and infection of a short evolution (RBT^®, IgM ELISA^® and IgG ELISA^® seropositive) was found (OR = 8.9, 95% CI: 1.0–81.1, p = 0.052), and strong evidence of an association between this outcome and the slaughter of cattle (OR = 5.3, 95% CI: 1.4–19.6, p = 0.013). There was strong evidence of a positive association between inactive/resolved infection and veterinary officials vs. farm workers exposed to seropositive herds (OR = 7.0, 95% CI: 2.4–20.2, p < 0.001), with a simultaneous negative association with the handling of afterbirth or placenta (OR = 3.9, 95% CI: 1.3–11.3, p = 0.012). Findings suggest a proportion of undetected clinical cases of brucellosis amongst workers on cattle farms in Gauteng.

Quantitative evaluation of the infection dynamics of bovine brucellosis in Tanzania

Brucellosis is endemic in Tanzania. A cross-sectional study was conducted at 17 cattle farms in agro-pastoral areas in Tanzania to identify risk factors associated with the within-farm prevalence of bovine brucellosis and to quantitatively assess the infection dynamics through disease modelling. Cattle blood sampling and interviews with farmers using a structured questionnaire were conducted. A total of 673 serum samples were screened using the Rose-Bengal plate test (RBPT), and sero-positivity of RBPT-positive samples was confirmed using a competitive enzyme-linked immunosorbent assay. Zero-inflated binomial regression was performed for univariable and multivariable risk factor analyses of within-farm prevalence. Several susceptible-infectious (SI) models were compared based on deviance information criteria, and age-dependent force of infection (FOI) was measured using age-specific prevalence data for the 10 infection-positive farms. Using the diagnoses of cows on the 17 farms, the basic reproduction number, R₀, was also calculated. The farm-level prevalence and animal-level adjusted prevalence were 58.8 % (10/17, 95 % confidence interval: 33.5-80.6 %) and 7.0 % (28/673, 95 % credible interval: 5.7-8.4 %), respectively. The risk factor for high within-farm prevalence was introduction of cattle from other herds. A mathematical model with constant FOI showed the annual probability of infection as 1.4 % (95 % credible interval: 1.0 %-2.0 %). The R₀ was 1.07. The constant FOI could have been due to the predominant mode of infection being transmission of Brucella from contaminated aborted materials during grazing. Direct purchase of infected cattle could facilitate efficient transmission between susceptible animals through abortion.

Working towards development of a sustainable brucellosis control programme, the Azerbaijan example

Brucellosis caused by Brucella abortus and Brucella melitensis is endemic in the Republic of Azerbaijan but a complex mix of fiscal, political and technical constraints has impeded regulatory authority decision making for adoption of a sustainable national control programme. This paper reports a series of epidemiologic studies of the disease in animals and humans which we conducted between 2009 and 2020. A preliminary study and a subsequent larger study using vaccination of all non-pregnant female sheep and goats of breeding age and all females between 3 and 8 months with conjunctival Rev1 vaccine both recorded significant reduction in small ruminant seroprevalences. A case control study of winter pasture flocks found many case and control farmers used raw milk to make dairy products for sale, ate fresh cheese and sold dairy products in unregulated markets. Almost all farmers expressed willingness to pay a portion of the costs associated with elimination of brucellosis from their flocks. A pilot human study in 2009 led to a large study in 2017 which recorded an overall seroprevalence of 8.1% in humans. Persons in farm related occupations were at greater risk than urban persons and males were more likely to be seropositive than females. Risk factors included keeping small ruminants, using raw milk cheese and slaughtering animals whereas having heard education information about brucellosis and vaccinating against brucellosis were protective.

First Case of Brucellosis Caused by an Amphibian-type Brucella

We report the first case of brucellosis caused by an isolate whose genome is identical that of a frog isolate from Texas, demonstrating the zoonotic potential of amphibian-type Brucella. Importantly, with such atypical Brucella, correct diagnosis cannot be performed using routine serological tests or identification methods.

Leptospira interrogans Serovar Hardjo Seroprevalence and Farming Practices on Small-Scale Dairy Farms in North Eastern India; Insights Gained from a Cross-Sectional Study

Leptospirosis is a zoonotic disease of major public health concern in India. Bovines play an important role in maintaining and transmitting this disease and proximity between dairy cows and humans makes the dairy cow-human nexus a transmission route of public health interest, yet one currently under-examined in North Eastern India. We report a cross-sectional survey carried out on small-scale dairy farms in the states of Assam and Bihar in North Eastern India investigating seroprevalence for Leptospira interrogans serovar Hardjo, the most common pathogenic serovar reported in cattle worldwide. Higher seroprevalence was reported on dairy farms in Bihar 4.5% (95% CI 2.6–7.5%) than in Assam 1.2% (95% CI 0.42–3.6%), but overall seroprevalence levels were low. The study is the first indication of leptospirosis circulating in small-scale dairy farms in these states. To correlate farming practices with zoonotic risk, we combined results from a dairy farmer questionnaire with cow seroprevalence. However, low seroprevalence levels found in this study made the identification of risk factors difficult. Nevertheless, poor farming practices around hygiene and biosecurity on dairy farms have been highlighted. Implementing simple measures could mitigate environmental contamination, and therefore, reduce the risk of Leptospira interrogans, and other zoonoses transmission, at the animal-environment-human interface.

Molecular epidemiology of Brucella species in mixed livestock-human ecosystems in Kenya

Brucellosis, caused by several species of the genus Brucella, is a zoonotic disease that affects humans and animal species worldwide. Information on the Brucella species circulating in different hosts in Kenya is largely unknown, thus limiting the adoption of targeted control strategies. This study was conducted in multi-host livestock populations in Kenya to detect the circulating Brucella species and assess evidence of host-pathogen associations. Serum samples were collected from 228 cattle, 162 goats, 158 sheep, 49 camels, and 257 humans from Narok and Marsabit counties in Kenya. Information on age, location and history of abortion or retained placenta were obtained for sampled livestock. Data on age, gender and location of residence were also collected for human participants. All samples were tested using genus level real-time PCR assays with primers specific for IS711 and bcsp31 targets for the detection of Brucella. All genus positive samples (positive for both targets) were further tested with a speciation assay for AlkB and BMEI1162 targets, specific for B. abortus and B. melitensis, respectively. Samples with adequate quantities aggregating to 577 were also tested with the Rose Bengal Test (RBT). A total of 199 (33.3%) livestock and 99 (38.5%) human samples tested positive for genus Brucella. Animal Brucella PCR positive status was positively predicted by RBT positive results (OR = 8.3, 95% CI 4.0-17.1). Humans aged 21-40 years had higher odds (OR = 2.8, 95% CI 1.2-6.6) of being Brucella PCR positive compared to the other age categories. The data on detection of different Brucella species indicates that B. abortus was detected more often in cattle (OR = 2.3, 95% CI 1.1-4.6) and camels (OR = 2.9, 95% CI 1.3-6.3), while B. melitensis was detected more in sheep (OR = 3.6, 95% CI 2.0-6.7) and goats (OR = 1.7, 95% CI 1.0-3.1). Both B. abortus and B. melitensis DNA were detected in humans and in multiple livestock host species, suggesting cross-transmission of these species among the different hosts. The detection of these two zoonotic Brucella species in humans further underpins the importance of One Health prevention strategies that target multiple host species, especially in the multi-host livestock populations.

Comparative proteomics of Brucella melitensis is a useful toolbox for developing prophylactic interventions in a One-Health context

Brucellosis caused by Brucella melitensis is a zoonosis frequently reported in the Mediterranean and Middle-East regions and responsible for important economic losses and reduced animal welfare. To date, current strategies applied to control or eradicate the disease relies on diagnostic tests that suffer from limited specificity in non-vaccinated animals; while prophylactic measures, when applied, use a live attenuated bacterial strain characterized by residual virulence on adult pregnant animals and difficulties in distinguishing vaccinated from infected animals. To overcome these issues, studies are desired to elucidate the bacterial biology and the pathogenetic mechanisms of both the vaccinal strain and the pathogenic strains. Proteomics has a potential in tackling issues of One-Health concern; here, we employed label-free shotgun proteomics to investigate the protein repertoire of the vaccinal strain B. melitensis Rev.1 and compare it with the proteome of the Brucella melitensis 16 M, a reference strain representative of B. melitensis field strains. Comparative proteomics profiling underlines common and diverging traits between the two strains. Common features suggest the potential biochemical routes responsible for the residual virulence of the vaccinal strain, whilst the diverging traits are suggestive biochemical signatures to be further investigated to provide an optimized diagnostic capable of discriminating the vaccinated from infected animals. The data presented in this study are openly available in PRIDE data repository at https://www.ebi.ac.uk/pride/, reference number PXD022472.

Clinical and laboratory features of brucellosis in a university hospital in Tunisia

AIM OF THE STUDY

The increase in the number of brucellosis cases between 2014 and 2017 (14 and 90 cases respectively) led us to study the biological and clinical-epidemiologic characteristics patients hospitalized in Rabta hospital of Tunis.

MATERIAL AND METHODS

This retrospective study was conducted in Rabta Hospital in Tunis between 2016 and 2017. It includes 131 patients who had a positive bacteriological diagnosis of Brucella between 2016 and 2017. Diagnosis of brucellosis was made in blood culture by using Bactalert (Biomerieux®). Identification of Brucella was realized by Gram staining, catalase, oxydase. Serological diagnosis was made by testing sera for brucellosis agglutinins with Rose Bengale and the standard agglutination test. The collected data were analyzed by SPSS softcare version 24.

RESULTS

The prevalence of Brucellosis in Rabta hospital increases from 14 cases in 2014 to 90 cases in 2017. The mean age was 45 years and ages range from 16 to 84 years. Rural origin was found in 75 cases (68%). Ninety-seven patients (89%) were hospitalized in the infectious diseases department. The average length of hospitalization was 17.25 days. Fifty-seven patients (52%) had a history of consuming unpasteurized dairy products and 45 (41%) were farmers. Fever was the predominant symptom in 104 cases (95%). Osteoarticular involvement is the most common complication of brucellosis and it occurred in 28% of patients. Blood cultures were 73 cases and 42 (57%) were positive for Brucella spp. Rose Bengale was positive in 100% of cases. High titles of the standard agglutination test (superior to 1/1280) were noted in 24 cases (22%).

CONCLUSION

Brucellosis is still endemic In Tunisia. Contact with domestic animals and consumption of raw milk and milk products seems to be the major mode of transmission. Control of animal infection by vaccination, occupational and personal hygiene, farm sanitation and preventive measures can reduce disease incidence.

Human brucellosis epidemiology in the pastoral area of Hulun Buir city, Inner Mongolia autonomous region, China, between 2003 and 2018

Human brucellosis represents a serious public health concern in Hulun Buir and requires a comprehensive epidemiologic analysis to define adapted control measures. The present study describes the case numbers, constituent ratios and incidence rate of human brucellosis. Conventional biotyping, that is abortus, melitensis, ovis and suis (AMOS)-PCR and multi-locus variable-number tandem repeat analysis (MLVA) were used to characterize the Brucella strains. Between 2003 and 2018, a total of 23,897 human brucellosis cases were reported, with an incidence rate of 56.03/100,000, which is 20 times higher than the country's average incidence. This incidence rate increased year after year, culminating in 2005 and decreased between 2011 and 2018. Because Hulun Buir relies on a nomadic livestock rearing system, brucellosis spreads easily among different animal species and humans. In Xin Barag Left Banner and Xin Barag Right Banner, the incidence rates were, respectively, 226.54/100,000 and 199.10/100,000, exceeding those observed in other areas. Most of the cases occurred in the 25- to 45-year-old group, accounting for 65.74% of the cases (15,709/23,897), and among farmers, accounting for 66.71% (15,942/23,897). The male to female incidence ratio was 2.67:1. The higher incidence in younger people and the large gender ratio reflected the unique traditional production and lifestyle of nomads. Most reported cases were observed from April to June, indicating that more than 40% of the cases were related to the delivery of domestic livestock. The biotyping showed that the 44 isolated strains were all B. melitensis, including 12 Brucella melitensis biovar (bv) 1 and 32 B. melitensis bv. 3. The strains displayed a genetic similarity of 80%-100%. Our hypothesis is that human brucellosis outbreak in this region may be originating from a limited source of infection, so further investigation is necessary. The epidemic situation of human brucellosis in Hulun Buir is extremely serious, strengthened surveillance and control in animals' brucellosis should be priority.

Brucellosis in wildlife in Africa: a systematic review and meta-analysis

This study aimed to consolidate current knowledge of wildlife brucellosis in Africa and to analyse available predictors of infection. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Information on species, test used, test results, area, rainfall, livestock and wildlife contact and year of study were extracted. This systematic review revealed 42 prevalence studies, nine disease control articles and six articles on epidemiology. Brucella abortus, Brucella melitensis, Brucella inopinata and Brucella suis were reported in wildlife. The prevalence studies revealed serological evidence of brucellosis in buffalo, antelope (positive in 14/28 species), carnivores (4/12) and other species (7/20) over the last five decades. Buffalo populations were more likely to be infected and had a higher seroprevalence than other species; the pooled seroprevalence was 13.7% (95% CI 10.3-17.3%) in buffalo, 7.1% (95% CI 1.1-15.5%) in carnivores and 2.1% (95% CI 0.1-4.9%) in antelope. Wildlife in high rainfall areas (≥ 800 mm) were more likely to be infected, and infected populations showed higher seroprevalence in high rainfall areas and in studies published after 2000. Domestic animal contact was associated with increased seroprevalence in antelope and carnivore species, but not in buffalo, supporting the hypothesis that buffalo may be a reservoir species.

Whole Genome Sequence Analysis of Brucella abortus Isolates from Various Regions of South Africa

The availability of whole genome sequences in public databases permits genome-wide comparative studies of various bacterial species. Whole genome sequence-single nucleotide polymorphisms (WGS-SNP) analysis has been used in recent studies and allows the discrimination of various Brucella species and strains. In the present study, 13 Brucella spp. strains from cattle of various locations in provinces of South Africa were typed and discriminated. WGS-SNP analysis indicated a maximum pairwise distance ranging from 4 to 77 single nucleotide polymorphisms (SNPs) between the South African Brucella abortus virulent field strains. Moreover, it was shown that the South African B. abortus strains grouped closely to B. abortus strains from Mozambique and Zimbabwe, as well as other Eurasian countries, such as Portugal and India. WGS-SNP analysis of South African B. abortus strains demonstrated that the same genotype circulated in one farm (Farm 1), whereas another farm (Farm 2) in the same province had two different genotypes. This indicated that brucellosis in South Africa spreads within the herd on some farms, whereas the introduction of infected animals is the mode of transmission on other farms. Three B. abortus vaccine S19 strains isolated from tissue and aborted material were identical, even though they originated from different herds and regions of South Africa. This might be due to the incorrect vaccination of animals older than the recommended age of 4-8 months or might be a problem associated with vaccine production.

Safety and Transcriptome Analysis of Live Attenuated Brucella Vaccine Strain S2 on Non-pregnant Cynomolgus Monkeys Without Abortive Effect on Pregnant Cynomolgus Monkeys

Brucellosis, caused by Brucella spp., is an important zoonotic disease leading to enormous economic losses in livestock, posing a great threat to public health worldwide. The live attenuated Brucella suis (B. suis) strain S2, a safe and effective vaccine, is widely used in animals in China. However, S2 vaccination in animals may raise debates and concerns in terms of safety to primates, particularly humans. In this study, we used cynomolgus monkey as an animal model to evaluate the safety of the S2 vaccine strain on primates. In addition, we performed transcriptome analysis to determine gene expression profiling on cynomolgus monkeys immunized with the S2 vaccine. Our results suggested that the S2 vaccine was safe for cynomolgus monkeys. The transcriptome analysis identified 663 differentially expressed genes (DEGs), of which 348 were significantly upregulated and 315 were remarkably downregulated. The Gene Ontology (GO) classification and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that these DEGs were involved in various biological processes (BPs), including the chemokine signaling pathway, actin cytoskeleton regulation, the defense response, immune system processing, and the type-I interferon signaling pathway. The molecular functions of the DEGs were mainly comprised of 2'-5'-oligoadenylate synthetase activity, double-stranded RNA binding, and actin-binding. Moreover, the cellular components of these DEGs included integrin complex, myosin II complex, and blood microparticle. Our findings alleviate the concerns over the safety of the S2 vaccine on primates and provide a genetic basis for the response from a mammalian host following vaccination with the S2 vaccine.

NLRP6-associated host microbiota composition impacts in the intestinal barrier to systemic dissemination of Brucella abortus

Brucella abortus is a Gram-negative bacterium responsible for a worldwide zoonotic infection—Brucellosis, which has been associated with high morbidity rate in humans and severe economic losses in infected livestock. The natural route of infection is through oral and nasal mucosa but the invasion process through host gut mucosa is yet to be understood. Studies have examined the role of NLRP6 (NOD-like receptor family pyrin domain-containing-6 protein) in gut homeostasis and defense against pathogens. Here, we investigated the impact of gut microbiota and NLRP6 in a murine model of Ba oral infection. Nlrp6^-/- and wild-type (WT) mice were infected by oral gavage with Ba and tissues samples were collected at different time points. Our results suggest that Ba oral infection leads to significant alterations in gut microbiota. Moreover, Nlrp6^-/- mice were more resistant to infection, with decreased CFU in the liver and reduction in gut permeability when compared to the control group. Fecal microbiota transplantation from WT and Nlrp6^-/- into germ-free mice reflected the gut permeability phenotype from the donors. Additionally, depletion of gut microbiota by broad-spectrum-antibiotic treatment prevented Ba replication in WT while favoring bacterial growth in Nlrp6^-/-. Finally, we observed higher eosinophils in the gut and leukocytes in the blood of infected Nlrp6^-/- compared to WT-infected mice, which might be associated to the Nlrp6^-/- resistance phenotype. Altogether, these results indicated that gut microbiota composition is the major factor involved in the initial stages of pathogen host replication and partially also by the resistance phenotype observed in Nlrp6 -/- mice regulating host inflammation against Ba infection.

Brucella abortus (Ba) is an intracellular bacterium that causes zoonotic and clinical problems worldwide. Although the common route of infection is through oral and nasal, the mechanisms toward the gastrointestinal mucosa response is still unexplored. It is well known that microbiota promotes and maintains host intestinal homeostasis during bacterial infections. However, mechanisms by which the gut microbiota affects the Ba infection have not yet been demonstrated. Here, we provide significant insights into the relationship between gut microbiota and B. abortus oral infection and demonstrate the gut microbiota contribution to the gut permeability and dissemination of Ba. Furthermore, we investigated the participation of the gut microbiota from Nlrp6 deficient mice, on the gut permeability and Ba infection. Substantial experiments performed, mostly in vivo, showed that gut microbiota alterations promote gut barrier disruption, as indicated by increased gut permeability after Ba oral infection. Thus, our work highlights the role of gut mucosal environment through gut microbiota and Nlrp6 molecule involved in host innate immune responses to Ba infection.

Brucella: Reservoirs and Niches in Animals and Humans

Brucella is an intracellular bacterium that causes abortion, reproduction failure in livestock and leads to a debilitating flu-like illness with serious chronic complications if untreated in humans. As a successful intracellular pathogen, Brucella has developed strategies to avoid recognition by the immune system of the host and promote its survival and replication. In vivo, Brucellae reside mostly within phagocytes and other cells including trophoblasts, where they establish a preferred replicative niche inside the endoplasmic reticulum. This process is central as it gives Brucella the ability to maintain replicating-surviving cycles for long periods of time, even at low bacterial numbers, in its cellular niches. In this review, we propose that Brucella takes advantage of the environment provided by the cellular niches in which it resides to generate reservoirs and disseminate to other organs. We will discuss how the favored cellular niches for Brucella infection in the host give rise to anatomical reservoirs that may lead to chronic infections or persistence in asymptomatic subjects, and which may be considered as a threat for further contamination. A special emphasis will be put on bone marrow, lymph nodes, reproductive and for the first time adipose tissues, as well as wildlife reservoirs.

Seroprevalence and Molecular Identification of Brucella spp. in Bovines in Pakistan-Investigating Association With Risk Factors Using Machine Learning

Bovine brucellosis is a global zoonosis of public health importance. It is an endemic disease in many developing countries including Pakistan. This study aimed to estimate the seroprevalence and molecular detection of bovine brucellosis and to assess the association of potential risk factors with test results. A total of 176 milk and 402 serum samples were collected from cattle and buffaloes in three districts of upper Punjab, Pakistan. Milk samples were investigated using milk ring test (MRT), while sera were tested by Rose–Bengal plate agglutination test (RBPT) and indirect enzyme-linked immunosorbent assay (i-ELISA). Real-time PCR was used for detection of Brucella DNA in investigated samples. Anti-Brucella antibodies were detected in 37 (21.02%) bovine milk samples using MRT and in 66 (16.4%) and 71 (17.7%) bovine sera using RBPT and i-ELISA, respectively. Real-time PCR detected Brucella DNA in 31 (7.71%) from a total of 402 bovine sera and identified as Brucella abortus. Seroprevalence and molecular identification of bovine brucellosis varied in some regions in Pakistan. With the use of machine learning, the association of test results with risk factors including age, animal species/type, herd size, history of abortion, pregnancy status, lactation status, and geographical location was analyzed. Machine learning confirmed a real observation that lactation status was found to be the highest significant factor, while abortion, age, and pregnancy came second in terms of significance. To the authors' best knowledge, this is the first time to use machine learning to assess brucellosis in Pakistan; this is a model that can be applied for other developing countries in the future. The development of control strategies for bovine brucellosis through the implementation of uninterrupted surveillance and interactive extension programs in Pakistan is highly recommended.

Control of Brucella melitensis in endemic settings: A simulation study in the Nile Delta, Egypt

Small ruminant brucellosis remains endemic in many low- and middle-income countries (LMICs), where it poses a major economic and public health burden. Lack of resources to support long-term vaccination, inherent characteristics of small ruminant production systems such as mixing of different flocks for grazing and limitations of the vaccines currently available, which can induce abortion in pregnant animals, have all hindered the effectiveness of control programmes. In the current study, the likely effect of different control scenarios on the seroprevalence of brucellosis among the small ruminant population in a hypothetical area of an endemic region was simulated using compartmental models. The model accounts for variability in transmission rates between villages and also simulates control scenarios that target villages with high seroprevalence. Our results show that vaccination of young replacement animals only can effectively reduce the prevalence of small ruminant brucellosis in endemic settings if a high vaccination coverage is achieved. On the other hand, test-and-slaughter alone is not a promising strategy for control of small ruminant brucellosis under husbandry practices typical of endemic low-resource settings. Furthermore, results show the potential success of some strategies requiring a relatively low overall vaccination coverage such as the vaccination of 50% of young replacements and 25% of adult animals each year. Control strategies selectively targeting high initial seroprevalence villages (p > 10%) did not decrease the overall seroprevalence to acceptable levels in most of the examined scenarios. Scenario analysis showed that the efficacy of the simulated control strategies can be improved mostly by decreasing the proportion of between-village trade and also by improving the performance of the used serological tests and increasing vaccine efficacy.

Brucellosis - laboratory workers' nightmare come true: A case study

Introduction

Brucella spp. are rarely encountered organisms in the medical microbiology laboratory and, when encountered, can cause concern in laboratory workers. Laboratory personnel may in fact develop serious disease as a result of this exposure. This case highlights shortcomings in recognition of Brucella spp. from a patient presenting atypically as well as the follow-up and management of an infected patient.

Case presentation

The patient was an 8-year-old boy from a rural area of South Africa who presented to an academic hospital with a bladder mass and history of enuresis in September 2016. Brucella melitensis was isolated from a blood culture submitted to the laboratory. The child was subsequently treated for brucellosis in November 2016.

Management and outcome

The source of infection in the patient was traced to consumption of unpasteurised milk from a local farmer. The patient was treated with doxycycline 100 mg twice daily and rifampicin 600 mg daily for 6 weeks and completed treatment, however he was not followed up at our hospital. The laboratory personnel, however, did not handle the specimen as a Biosafety Level 3 pathogen as this organism is not commonly encountered; they were provided with prophylaxis for brucellosis (rifampicin and doxycycline).

Conclusion

Brucella spp. is a dangerous pathogen, easily capable of causing significant exposure in an unsuspecting and unprepared laboratory. The case discusses the management of brucellosis in the infected patient as well as the management of laboratory exposure to Brucella spp. Our case also describes the public health response to a case of brucellosis.

One health approach to tackle brucellosis: a systematic review

Background

Brucellosis is the most significant and common bacterial zoonosis and is recognized as a re-emerging and neglected disease. Tackling zoonosis is very important for the health and the economy. One Health is an approach characterized by the integration of human and animal health, plants, and ecosystems and encourages joining local, national, and global multidisciplinary efforts to achieve optimal levels of health and collaboration among different disciplines to address complex health problems.

Objectives

The present study aimed to review published scientific literature related to the use of the One Health approach to tackle human brucellosis.

Methods

Web of Science (WoS), PubMed, Scopus, The Cochrane Library, and Embase databases were searched from inception until 30 January 2020. The reference lists of all relevant papers were hand-searched. Two authors extracted data from published studies independently. The Joanna Briggs Institute tool was used to assess the quality of studies.

Results

Of 2297 studies, 10 studies were deemed eligible, which were conducted between 2013 and 2019. Studies were performed in Uganda, Malta, Serbia, Greece, Mongolia, Azerbaijan, Israel, India, Ethiopia, and the USA. All studies suggested that brucellosis is still a major public health problem and that the most important aspect of the One Health approach is the interdependence of humans, ecosystems, and animals .Some studies have focused on livestock vaccination as the most effective way to prevent disease, and others have focused on the biology of Brucella infection and its transmission patterns. Some studies have pointed to the effectiveness of the One Health approach in all the phases of disease management as well as to its role in reducing health costs.

Conclusion

The success of the approach depends on the willingness of the decision-makers to implement the necessary policies. Due to the heterogeneity of current practices, and organizations involved in One Health approach-based programs, it will be incomplete without proper planning. To better implement the approach, strategies should be appraised and disseminated by experts and relevant stakeholders.

Evolutionary history and current distribution of the West Mediterranean lineage of Brucella melitensis in Italy

Ovine and caprine brucellosis, caused by Brucella melitensis, is one of the world’s most widespread zoonoses and is a major cause of economic losses in domestic ruminant production. In Italy, the disease remains endemic in several southern provinces, despite an ongoing brucellosis eradication programme. In this study, we used whole-genome sequencing to detail the genetic diversity of circulating strains, and to examine the origins of the predominant sub-lineages of B. melitensis in Italy. We reconstructed a global phylogeny of B. melitensis, strengthened by 339 new whole-genome sequences, from Italian isolates collected from 2011 to 2018 as part of a national livestock surveillance programme. All Italian strains belonged to the West Mediterranean lineage, which further divided into two major clades that diverged roughly between the 5th and 7th centuries. We observed that Sicily serves as a brucellosis burden hotspot, giving rise to several distinct sub-lineages. More than 20 putative outbreak clusters of ovine and caprine brucellosis were identified, several of which persisted over the 8 year survey period despite an aggressive brucellosis eradication campaign. While the outbreaks in Central and Northern Italy were generally associated with introductions of single clones of B. melitensis and their subsequent dissemination within neighbouring territories, we observed weak geographical segregation of genotypes in the southern regions. Biovar determination, recommended in routine analysis of all Brucella strains by the World Organisation for Animal Health (OIE), could not discriminate among the four main global clades. This demonstrates a need for updating the guidelines used for monitoring B. melitensis transmission and spread, both at the national and international level, and to include whole-genome-based typing as the principal method for identification and tracing of brucellosis outbreaks.

Scoping review of brucellosis in Cameroon: Where do we stand, and where are we going?

Brucellosis is a zoonotic disease known to be endemic to parts of western and sub-Saharan Africa. However, the epidemiology for humans and animals remains largely unknown in many of these countries with Cameroon being a typical example. Despite common knowledge that brucellosis affects livestock, the actual number of infected animals remains unknown. Through a scoping review, the current known status of the disease is described. The aim is to ascertain relevant and publicly accessible research and knowledge of human and animal brucellosis in the country, and to provide an overview of the factors associated with its known persistence. Seroprevalence has been estimated and published in 12 separate instances (1 human; 9 cattle; 1 human and cattle; and 1 that includes cattle, pigs, and small ruminants), between 1982 and 2020, in 9 of the country's 10 geopolitical regions. In 1983, Brucella abortus and B. melitensis were isolated in cattle, but no further bacterial isolation has been published since. The seroprevalence from 196 total humans has ranged between 5.6% and 28.1%, and between 3.0% and 30.8% for 14,044 total cattle. As there is no ongoing surveillance program, it is not currently possible to identify the specific Brucella spp. that are endemic to the country and its regions. There are sufficient agricultural systems of cattle, pigs, goats, and sheep to sustain the presence of multiple Brucella spp. Surveillance information is the cornerstone of epidemiologic decision making, and is needed to direct policy makers, public health authorities, and veterinary services to appropriate actions. A combination of serological and molecular based diagnostics for surveillance is necessary to identify, quantify, and direct the appropriate public health interventions. Cameroon has an opportunity to build public and animal health infrastructure, leading the way for central Africa in the management and future eradication of brucellosis.

The global epidemiology of Brucella infections in terrestrial wildlife: A meta-analysis

Brucellosis is a widespread zoonotic disease with serious consequences on human and animal health. Brucella infections were reported in many terrestrial wild animals, from subtropical and temperate regions to arctic regions. In many areas, the epidemiology of brucellosis in wildlife is closely associated with the occurrence of the disease in livestock. Some wild species may contribute to the re-introduction of Brucella infections in livestock (spillback), even in officially brucellosis-free (OBF) regions. Through meta-regression analysis, this study draws a global picture of the prevalence of Brucella spp. in terrestrial wild animals, trying to determine most affected subgroups as well as preferential sampling and screening methods. For this purpose, a literature search was carried out among publications published from 1983 to 2019. Different subgroups were compared according to animal species, feeding, gender, age as well as the method used for sampling and for brucellosis diagnostic. To determine heterogeneity of studies, chi-squared test was used and a random-effects model (REM) estimated the pooled prevalence among subgroups. A total of 68 publications, comprising 229 data reports/studies, were selected. The most-reported Brucella species in wildlife was Brucella abortus, and the highest prevalence rate was found in American bison, Bison bison (39.9%) followed by Alpine ibex, Capra ibex (33%). Serology was the most widely applied diagnostic approach (66%), while PCR appeared to be highly sensitive (36.62% of positive results). The gender of animals showed no significant association with the prevalence of brucellosis (p > .05). Blood samples and visceral organs constituted the great majority of specimen used for the detection of Brucella spp., while lymph nodes showed a high prevalence of positive samples (94.6%). The present study provides insight into the global epidemiology and enzootic potential of brucellosis in wild terrestrial animals worldwide, aiming at helping the appropriate authorities to strengthen prevention, surveillance and control strategies.

Bibliometric analysis of global research output on antimicrobial resistance in the environment (2000-2019)

Background

Antimicrobial resistance (AMR) is a global health threat that requires a "One Health" approach. Of the One Health triad, the environmental component is the most dynamic and most neglected. Therefore, the objective of the current study was to assess and analyze global research activity on AMR in the environment.

Methods

This was a bibliometric descriptive study of publications on AMR in the environment. Publications were retrieved using SciVerse Scopus for the study period from 2000 to 2019. The search query was developed using terms and phrases related to the topic. The retrieved publications were analyzed for specific bibliometric indicators including annual growth, citation analysis, key players, research output for each world regions, research themes, and occurrences of different drug classes of antimicrobials. Visualization maps including research collaboration were created using VOSviewer program. The Hirsch (h) index was used to assess scientific impact.

Results

There were 2611 research articles based on the implemented research query. The retrieved documents had an average of 22 citations per document and an h-index of 122. The annual number of publications showed a steep increase from 2011 to 2019. The major research themes in the field were (1) dissemination and abundance of antibiotic-resistant genes and (2) detection of bacterial strains or antibiotic residues in various environmental isolates. The bulk of the retrieved articles (n = 899; 34.4%) originated from the European region. China led with 598 (22.9%) documents. Four of the top 10 active institutions were in China. The top 10 active countries had relatively inadequate international research collaboration. The most commonly encountered antibiotic drug classes in the retrieved articles were penicillin/cephalosporin (n = 1152 occurrences). The most frequently encountered pathogen in the retrieved publications was E. coli (n = 666). The Science of the Total Environment journal was the most prolific journal with 139 (5.3%) publications.

Conclusion

Scientific literature on the AMR in the environment has witnessed a steep growth lately with a leading role of China and Chinese institutions. Data on AMR in the environment need to be collected from all world regions including the Eastern Mediterranean and African regions through research collaboration and funding of research in this field.

Seroprevalence and Molecular Identification of Brucella spp. in Camels in Egypt

Brucellosis is one of the most important worldwide zoonoses of many countries including Egypt. Camel brucellosis has not gained much attention in Egypt yet. This study is focused on the three governorates with the highest camel populations and the largest camel markets in the country to determine the disease seroprevalence and identify the Brucella species in local camel holdings. In total, 381 serum samples were collected from male and female camels from Giza, Aswan, and Al-Bahr Al-Ahmar (the Red Sea) governorates. Samples were serologically examined using the Rose-Bengal plate test (RBPT), indirect ELISA (i-ELISA), competitive ELISA (c-ELISA) and complement fixation test (CFT). Brucella antibodies were detected in 59 (15.5%), 87 (22.8%), 77 (20.2%) and 118 (31.0%) of sera by RBPT, i-ELISA, c-ELISA and CFT, respectively. Using real-time PCR, Brucella DNA was amplified in 32 (8.4%) seropositive samples including Brucella abortus (25/32), Brucella suis (5/32) and Brucella melitensis (2/32), defining a complex epidemiological status. To the best of our knowledge, this is the first study reporting Brucella suis DNA in camel serum. The risk-associated factors including age, sex, breed and geographical distribution were statistically analyzed, showing non-significant association with seroprevalence. The results of this study will raise awareness for camel brucellosis and help develop effective control strategies.

Risk factors for Brucella spp. and Coxiella burnetii infection among small ruminants in Eastern India

Small ruminants are the main reservoirs for brucellosis and coxiellosis, two zoonotic diseases affecting livestock production, and posing a public health threat in India. Understanding disease prevalence and risk factors associated with small ruminant infection can help mitigate disease transmission.

We report a cross-sectional survey in the states of Assam and Odisha in Eastern India. We interviewed 244 farmers to assess knowledge, attitude and practices relevant to brucellosis and coxiellosis infection. Serum samples from 411 goats and 21 sheep were analysed using enzyme-linked immunosorbent assay and Rose-Bengal Brucella agglutination plate test. Higher Brucella and Coxiella burnetii seroprevalence were found in Odisha (22% and 11.5%, respectively) than Assam (9.8% and 1.6%, respectively), and certain districts in Odisha were at higher risk. No association was found between seropositive animals and clinical signs, a challenge when attempting to identify seropositive animals in the herd. None of the farmers interviewed were aware of brucellosis, its aetiology, clinical form, or zoonotic risk. This study acts as a first indication of the extent of these diseases among small ruminants in these Indian states, highlighting how farming practices are associated with increased risk of infection. More research is urgently needed to mitigate zoonoses transmission in this region.

Brucellosis in the Middle East: Current situation and a pathway forward

Brucellosis is a bacterial endemic zoonotic disease of global significance with detrimental impacts on public health and food animal production. It is caused by Brucella spp., an expanding group of pathogens able to infect various host species. Bovines and small ruminants, which excrete the bacteria in milk and in reproductive discharges, are major sources of infection for humans and other animals. Contact with contaminated animals and consumption of unpasteurized dairy products are the main routes for human infection. In spite of the considerable progress of knowledge gained and success achieved in brucellosis control in the developed world, this disease continues to be an important burden in the Middle East (ME). Common risk factors implicated in the difficulty and complexity of brucellosis control within the region include (1) social and political instabilities; (2) insufficient resources and infrastructure for appropriate diagnosis, reporting, and implementation of control measures; (3) variation of livestock husbandry systems and their commingling with other livestock and wildlife; and (4) traditional cultural practices, including consumption of unpasteurized dairy products. Development of core interdisciplinary competencies is required for a true One Health–based endeavor against the disease. National awareness and educational programs addressing all population sectors from consumers to decision-makers seem to be the next logical, sustainable, and economically viable approach toward improving disease status in this region. In the present review, we describe the current situation of brucellosis in the ME, focusing on the major limitations and shortcomings regarding disease control. We propose a regional approach toward public awareness of brucellosis as the first step in mitigating the disease and discuss the potential benefits, and components of such a strategy, which can further be used as a model for other endemic zoonotic diseases.

Occupational exposure to Brucella spp.: A systematic review and meta-analysis

Brucellosis is a neglected zoonotic disease of remarkable importance worldwide. The focus of this systematic review was to investigate occupational brucellosis and to identify the main infection risks for each group exposed to the pathogen. Seven databases were used to identify papers related to occupational brucellosis: CABI, Cochrane, Pubmed, Scielo, Science Direct, Scopus and Web of Science. The search resulted in 6123 studies, of which 63 were selected using the quality assessment tools guided from National Institutes of Health (NIH) and Case Report Guidelines (CARE). Five different job-related groups were considered greatly exposed to the disease: rural workers, abattoir workers, veterinarians and veterinary assistants, laboratory workers and hunters. The main risk factors and exposure sources involved in the occupational infection observed from the analysis of the articles were direct contact with animal fluids, failure to comply with the use of personal protective equipment, accidental exposure to live attenuated anti-brucellosis vaccines and non-compliance with biosafety standards. Brucella species frequently isolated from job-related infection were Brucella melitensis, Brucella abortus, Brucella suis and Brucella canis. In addition, a meta-analysis was performed using the case-control studies and demonstrated that animal breeders, laboratory workers and abattoir workers have 3.47 [95% confidence interval (CI); 1.47-8.19] times more chance to become infected with Brucella spp. than others individuals that have no contact with the possible sources of infection. This systematic review improved the understanding of the epidemiology of brucellosis as an occupational disease. Rural workers, abattoir workers, veterinarians, laboratory workers and hunters were the groups more exposed to occupational Brucella spp. infection. Moreover, it was observed that the lack of knowledge about brucellosis among frequently exposed professionals, in addition to some behaviors, such as negligence in the use of individual and collective protective measures, increases the probability of infection.

Prevalence and speciation of brucellosis in febrile patients from a pastoralist community of Tanzania

Brucellosis is an endemic zoonosis in sub-Saharan Africa. Pastoralists are at high risk of infection but data on brucellosis from these communities are scarce. The study objectives were to: estimate the prevalence of human brucellosis, identify the Brucella spp. causing illness, describe non-Brucella bloodstream infections, and identify risk factors for brucellosis in febrile patients from a pastoralist community of Tanzania. Fourteen (6.1%) of 230 participants enrolled between August 2016 and October 2017 met study criteria for confirmed (febrile illness and culture positivity or ≥four-fold rise in SAT titre) or probable (febrile illness and single SAT titre ≥160) brucellosis. Brucella spp. was the most common bloodstream infection, with B. melitensis isolated from seven participants and B. abortus from one. Enterococcus spp., Escherichia coli, Salmonella enterica, Staphylococcus aureus and Streptococcus pneumoniae were also isolated. Risk factors identified for brucellosis included age and herding, with a greater probability of brucellosis in individuals with lower age and who herded cattle, sheep or goats in the previous 12 months. Disease prevention activities targeting young herders have potential to reduce the impacts of human brucellosis in Tanzania. Livestock vaccination strategies for the region should include both B. melitensis and B. abortus.

B Cells Inhibit CD4+ T Cell-Mediated Immunity to Brucella Infection in a Major Histocompatibility Complex Class II-Dependent Manner

Brucella spp. are facultative intracellular bacteria notorious for their ability to induce a chronic, and often lifelong, infection known as brucellosis. To date, no licensed vaccine exists for prevention of human disease, and mechanisms underlying chronic illness and immune evasion remain elusive. We and others have observed that B cell-deficient mice challenged with Brucella display reduced bacterial burden following infection, but the underlying mechanism has not been clearly defined. Here, we show that at 1 month postinfection, B cell deficiency alone enhanced resistance to splenic infection ∼100-fold; however, combined B and T cell deficiency did not impact bacterial burden, indicating that B cells only enhance susceptibility to infection when T cells are present. Therefore, we investigated whether B cells inhibit T cell-mediated protection against Brucella Using B and T cell-deficient Rag1^-/- animals as recipients, we demonstrate that adoptive transfer of CD4⁺ T cells alone confers marked protection against Brucella melitensis that is abrogated by cotransfer of B cells. Interestingly, depletion of CD4⁺ T cells from B cell-deficient, but not wild-type, mice enhanced susceptibility to infection, further confirming that CD4⁺ T cell-mediated immunity against Brucella is inhibited by B cells. In addition, we found that the ability of B cells to suppress CD4⁺ T cell-mediated immunity and modulate CD4⁺ T cell effector responses during infection was major histocompatibility complex class II (MHCII)-dependent. Collectively, these findings indicate that B cells modulate CD4⁺ T cell function through an MHCII-dependent mechanism which enhances susceptibility to Brucella infection.

Practising co-production and interdisciplinarity: Challenges and implications for one health research

We review the nature of interdisciplinary research in relation to One Health, a perspective on human-animal health which would appear to merit close interdisciplinary cooperation to inform public health policy. We discuss the relationship between biological sciences, epidemiology and the social sciences and note that interdisciplinary work demands attention be given to a range of often neglected epistemological and methodological issues. Epidemiologists may sometimes adopt social science techniques as "bolt-ons"1 to their research without having a complete understanding of how the social sciences work. The paper introduces a range of social science concepts and applies them to the challenges of understanding and practicing participatory and local epidemiology. We consider the problem of co-production of knowledge about One Health and zoonotic diseases in relation to funding structures, working in large international teams and explore some of the often-neglected realities of working across disciplines and cultures. We do this in part by applying the concept of value-chain to the research process.

Genetic epidemiology of the Alpine ibex reservoir of persistent and virulent brucellosis outbreak

While it is now broadly accepted that inter-individual variation in the outcomes of host-pathogen interactions is at least partially genetically controlled, host immunogenetic characteristics are rarely investigated in wildlife epidemiological studies. Furthermore, most immunogenetic studies in the wild focused solely on the major histocompatibility complex (MHC) diversity despite it accounts for only a fraction of the genetic variation in pathogen resistance. Here, we investigated immunogenetic diversity of the Alpine ibex (Capra ibex) population of the Bargy massif, reservoir of a virulent outbreak of brucellosis. We analysed the polymorphism and associations with disease resistance of the MHC Class II Drb gene and several non-MHC genes (Toll-like receptor genes, Slc11A1) involved in the innate immune response to Brucella in domestic ungulates. We found a very low neutral genetic diversity and a unique MHC Drb haplotype in this population founded few decades ago from a small number of individuals. By contrast, other immunity-related genes have maintained polymorphism and some showed significant associations with the brucellosis infection status hence suggesting a predominant role of pathogen-mediated selection in their recent evolutionary trajectory. Our results highlight the need to monitor immunogenetic variation in wildlife epidemiological studies and to look beyond the MHC.

Immunopathogenesis of Hepatic Brucellosis

The hepatic immune system can induce rapid and controlled responses to pathogenic microorganisms and tumor cells. Accordingly, most of the microorganisms that reach the liver through the blood are eliminated. However, some of them, including Brucella spp., take advantage of the immunotolerant capacity of the liver to persist in the host. Brucella has a predilection for surviving in the reticuloendothelial system, with the liver being the largest organ of this system in the human body. Therefore, its involvement in brucellosis is practically invariable. In patients with active brucellosis, the liver is commonly affected, and the most frequent clinical manifestation is hepatosplenomegaly. The molecular mechanisms implicated in liver damage have been recently elucidated. It has been demonstrated how Brucella interacts with hepatocytes inducing its death by apoptosis. The inflammatory microenvironment and the direct effect of Brucella on hepatic stellate cells (HSC) induce their activation and turn these cells from its quiescent form to their fibrogenic phenotype. This HSC activation induced by Brucella infection relies on the presence of a functional type IV secretion system and the effector protein BPE005 through a mechanism involved in the activation of the autophagic pathway. Finally, the molecular mechanisms of liver brucellosis observed so far are shedding light on how the interaction of Brucella with liver cells may play an important role in the discovery of new targets to control the infection. In this review, we report the current understanding of the interaction between liver structural cells and immune system cells during Brucella infection.

Research Progress on Brucellosis

Brucellosis is a debilitating febrile illness caused by an intracellular Brucella. The disease is distributed in humans and animals widely, especially in developing countries. Ten species are included in the genus Brucella nowadays; four species of them are pathogenic to humans, which make brucellosis a zoonosis with more than 500,000 new cases reported annually. For human brucellosis, the most pathogenic species is B. melitensis followed by B. suis, while B. abortus is the mildest type of brucellosis. The infection mechanism of Brucella is complicated and mostly relies on its virulence factors. The therapy of the disease contains vaccination and antibiotic. However, there are some defects in currently available vaccines such as the lower protective level and safety. Thus, safe and efficient vaccines for brucellosis are still awaited. The dual therapy of antibacterial is effective in the treatment of brucellosis if a rapid and exact detection method is found.

Identification, Genotyping and Antimicrobial Susceptibility Testing of Brucella spp. Isolated from Livestock in Egypt

Brucellosis is a highly contagious zoonosis worldwide with economic and public health impacts. The aim of the present study was to identify Brucella (B.) spp. isolated from animal populations located in different districts of Egypt and to determine their antimicrobial resistance. In total, 34-suspected Brucella isolates were recovered from lymph nodes, milk, and fetal abomasal contents of infected cattle, buffaloes, sheep, and goats from nine districts in Egypt. The isolates were identified by microbiological methods and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Differentiation and genotyping were confirmed using multiplex PCR for B. abortus, Brucella melitensis, Brucella ovis, and Brucella suis (AMOS) and Bruce-ladder PCR. Antimicrobial susceptibility testing against clinically used antimicrobial agents (chloramphenicol, ciprofloxacin, erythromycin, gentamicin, imipenem, rifampicin, streptomycin, and tetracycline) was performed using E-Test. The antimicrobial resistance-associated genes and mutations in Brucella isolates were confirmed using molecular tools. In total, 29 Brucella isolates (eight B. abortus biovar 1 and 21 B. melitensis biovar 3) were identified and typed. The resistance of B. melitensis to ciprofloxacin, erythromycin, imipenem, rifampicin, and streptomycin were 76.2%, 19.0%, 76.2%, 66.7%, and 4.8%, respectively. Whereas, 25.0%, 87.5%, 25.0%, and 37.5% of B. abortus were resistant to ciprofloxacin, erythromycin, imipenem, and rifampicin, respectively. Mutations in the rpoB gene associated with rifampicin resistance were identified in all phenotypically resistant isolates. Mutations in gyrA and gyrB genes associated with ciprofloxacin resistance were identified in four phenotypically resistant isolates of B. melitensis. This is the first study highlighting the antimicrobial resistance in Brucella isolated from different animal species in Egypt. Mutations detected in genes associated with antimicrobial resistance unravel the molecular mechanisms of resistance in Brucella isolates from Egypt. The mutations in the rpoB gene in phenotypically resistant B. abortus isolates in this study were reported for the first time in Egypt.

Serological and Molecular Identification of Brucella spp. in Pigs from Cairo and Giza Governorates, Egypt

Brucellosis is considered as endemic disease of animals and humans since thousands of years in Egypt. However, brucellosis in pigs has never been reported in Egypt. Thus, serological and molecular assays were applied to detect anti-Brucella antibodies and DNA in serum samples collected from pigs. In total 331 blood samples collected from male and female pigs at slaughterhouses of Cairo and Giza governorates were investigated using Brucella c- and i-ELISA and Brucella real-time PCR. Anti-Brucella antibodies were detected in 16 (4.83%) and 36 (10.8%) sera by i-ELISA and c-ELISA, respectively. Brucella DNA was detected in 10 (3.02%) seropositive samples and identified as Brucella melitensis (7/10) and Brucella suis (3/10). A higher prevelance was found in boars. This is the first study investigating pig brucellosis in Egypt. The results of this study will raise awareness for brucellosis in these farm animals and will help to develop effective control strategies.

Contamination of milk and dairy products by Brucella species: A global systematic review and meta-analysis

Brucellosis is known as an influential zoonosis in different regions worldwide, with significant effects on the reproductive performance of livestock. Considering the high incidence of brucellosis in dairy products and further negative impacts on food safety, the present study was aimed to systematically investigate prevalence worldwide among published data regarding the identification of Brucella spp. in dairy products. In this regard, some databases, i.e., Scopus, PubMed, Embase, and Web of Science have been searched to retrieve all related articles regarding the incidence of Brucella contaminations in dairy products from 1 January 1983 to 1 April 2019. The prevalence of Brucella spp. in unpasteurized dairy products based on countries, WHO regions, and dairy product subgroups were evaluated and statistically compared. Based on the findings, the prevalence of Brucella spp. in dairy products increased while the GDP (C = 0.17, P-value < 0.001) and HDI (C = 0.19, P-value < 0.001) ranking decreased. Also, the highest prevalence of Brucella contamination in dairy products was noted in buffalo (25.91%) and goat (17.90%), respectively. The lowest and highest prevalence of Brucella spp. were observed in the Western Pacific (15.32%) and the Southeast Asia region (25.55%), respectively. Also, the rank order of WHO regions based on odds ratio (OR) was Southeast Asia region (2.84) > Eastern Mediterranean (2.41) > Region of America (1.65) > European Region (1.54) > Africa region (1.46) > Western Pacific (reference). The results of this study showed that decreasing poverty and an increase in the level of education in societies could reduce the prevalence of Brucella spp. in dairy products. The outcome of the current investigation can be used for the implementation of sustainable intervention and prevention strategies in affected regions.

Whole Genome Sequencing for Tracing Geographical Origin of Imported Cases of Human Brucellosis in Sweden

Human infections with Brucella melitensis are occasionally reported in Sweden, despite the fact that the national flocks of sheep and goats are officially free from brucellosis. The aim of our study was to analyze 103 isolates of B. melitensis collected from patients in Sweden between 1994 and 2016 and determine their putative geographic origin using whole genome sequencing (WGS)-based tools. The majority of the strains were assigned to East Mediterranean and African lineages. Both in silico Multiple Loci VNTR (Variable Number of Tandem Repeats) Analysis (MLVA) and core genome Multilocus Sequence Typing (cgMLST) analyses identified countries of the Middle East as the most probable source of origin of the majority of the strains. Isolates collected from patients with travel history to Iraq or Syria were often associated with genotypes from Turkey, as the cgMLST profiles from these countries clustered together. Sixty strains were located within a distance of 20 core genes to related genotypes from the publicly available database, and for eighteen isolates, the closest genotype was different by more than 50 loci. Our study showed that WGS based tools are effective in tracing back the geographic origin of infection of patients with unknown travel status, provided that public sequences from the location of the source are available.

Impact of geographical factors on the spread of animal brucellosis in the Republic of Kazakhstan

In Latin and Central America and in most Asian countries, brucellosis remains an insufficiently studied disease. This study aims to determine the national and regional incidence of brucellosis among cattle (cows) and small ruminants (sheep, goats) in the Republic of Kazakhstan, as well as to identify the effect of climatic and geographical factors on the incidence rates. Thematic maps were created in an open geographic information system QGIS version 2.8. in order to identify the natural and socio-economic factors that influence the spread of the disease overlay method was used. Local cluster analysis was used in order to identify additional causes of the disease. Findings show the following values of Pearson correlation between the overall population and the number of animals infected: 0.68 for cows, p ≤ 0.005, and 0.56 for sheep and goats, p ≤ 0.03. Thus, the larger the heard in a given area, the greater likelihood of having brucellosis. Data processing reveals that Kazakhstan has almost twice as many regions good for cattle breeding as regions that are good for the small ruminants farming. The correlation variables for cattle and small ruminants are approximately the same. On the basis of the performed research the author proposes to amend the accepted methodology of epidemiology surveillance by the methods based on spatial (geographical) analysis. It is also proposed to adjust the process of breeding cattle and small ruminants considering the additional health recommendations that take into account the geographical aspects of the spread of the disease.

Seroprevalence and molecular characterization of Brucella species in naturally infected cattle and sheep

Brucellosis is one of the most economically significant infectious diseases in Egypt. The study aimed to assess the seroprevalence by indirect ELISA by examining serum samples from 720 cattle and 320 sheep and detection and characterization of Brucella spp. from 24 clinical samples (placenta) by bacterial culture (BC) and PCR targeting bcsp31 gene. The seroprevalence was 16.7% and 16.25% in cattle and sheep, respectively. There was a significant association (P < 0.05) between the seroprevalence of brucellosis and sex at the level of cattle and age at the sheep level, where seroprevalence was 18.7% in female cattle and 22% in sheep > 2 years. Likewise, seroprevalence was significantly (P < 0.05) different among locations for cattle. Of the 24 clinical samples tested by BC, B. abortus was isolated and identified in 100% of clinical samples. Using PCR, all Brucella strains were positive (100%) regarding bcsp31gene. Nucleotide analyses of seven bcsp31 sequences of the identified strains revealed 99.3-100% identity, with one nucleotide divergence. These results provide an insight into the brucellosis, particularly with the detection of B. abortus from sheep, therefore, further wide epidemiological studies are needed to develop appropriate prevention and control strategies.

Opportunities for Brucellosis Control in Mexico: Views Based on the Sustainable Livelihoods Perspective

Caprine brucellosis is a main constraint for small-scale goat husbandry systems in the Global South, as it negatively affects production parameters and can be transmitted to humans. The aim of this manuscript is to point out opportunities for brucellosis control in a resource poor area. The present paper draws from previous research in two Mexican states, Jalisco and Michoacán, both within the Bajío region. Main opportunities for brucellosis control are discussed within the "Sustainable Livelihoods Perspective." Goat farming gives farmers a number of livelihoods benefits: food, cash, prestige, and a job. Goat farming is also a reason for some farmers to stay in their villages rather than to migrate to the US. This livelihood strategy, however, is threatened by brucellosis, which is endemic in the goat population of the region. Brucellosis control, however, offers an opportunity for small-scale goat farmers to enhance health and welfare. The socio-economic context is very important in planning a successful brucellosis control campaign. Control strategies should be planned considering the local goat farming husbandry and the views of the farmers.

A Review of Zoonotic Pathogens of Dromedary Camels

Dromedary, or one-humped, camels Camelus dromedarius are an almost exclusively domesticated species that are common in arid areas as both beasts of burden and production animals for meat and milk. Currently, there are approximately 30 million dromedary camels, with highest numbers in Africa and the Middle East. The hardiness of camels in arid regions has made humans more dependent on them, especially as a stable protein source. Camels also carry and may transmit disease-causing agents to humans and other animals. The ability for camels to act as a point source or vector for disease is a concern due to increasing human demands for meat, lack of biosafety and biosecurity protocols in many regions, and a growth in the interface with wildlife as camel herds become sympatric with non-domestic species. We conducted a literature review of camel-borne zoonotic diseases and found that the majority of publications (65%) focused on Middle East respiratory syndrome (MERS), brucellosis, Echinococcus granulosus, and Rift Valley fever. The high fatality from MERS outbreaks during 2012-2016 elicited an immediate response from the research community as demonstrated by a surge of MERS-related publications. However, we contend that other camel-borne diseases such as Yersinia pestis, Coxiella burnetii, and Crimean-Congo hemorrhagic fever are just as important to include in surveillance efforts. Camel populations, particularly in sub-Saharan Africa, are increasing exponentially in response to prolonged droughts, and thus, the risk of zoonoses increases as well. In this review, we provide an overview of the major zoonotic diseases present in dromedary camels, their risk to humans, and recommendations to minimize spillover events.

Genomic Characterization Provides New Insights for Detailed Phage- Resistant Mechanism for Brucella abortus

As the causative agent of cattle brucellosis, Brucella abortus commonly exhibits smooth phenotype (by virtue of colony morphology) that is characteristically sensitive to specific Brucella phages, playing until recently a major role in taxonomical classification of the Brucella species by the phage typing approach. We previously reported the discrepancy between traditional phenotypic typing and MLVA results of a smooth phage-resistant (SPR) strain Bab8416 isolated from a 45-year-old custodial worker with brucellosis in a cattle farm. Here, we performed whole genome sequencing and further obtained a complete genome sequence of strain Bab8416 by a combination of multiple NGS technologies and routine PCR sequencing. The detailed genetic differences between B. abortus SPR Bab8416 and large smooth phage-sensitive (SPS) strains were investigated in a comprehensively comparative genomic study. The large indels between B. abortus SPS strains and Bab8416 showed possible divergence between two evolutionary branches at a far phylogenetic node. Compared to B. abortus SPS strain 9-941 (Bab9-941), the specific re-arrangement event in Bab8416 displaying a closer linear relationship with B. melitensis 16M than other B. abortus strains resulted in the truncation of c-di-GMP synthesis, and 3 c-di-GMP-metabolizing genes, were present in Bab8416 and B. melitensis 16M, but absent in Bab9-941 and other B. abortus strains, indicating potential SPR-associated key determinants and novel molecular mechanisms. Moreover, despite almost completely intact smooth LPS related genes, only one mutated OmpA family protein of Bab8416, functionally related to flagellar and efflux pump, was newly identified. Several point mutations were identified to be Bab8416 specific while a majority of them were verified to be B. abortus ST2 characteristic. In conclusion, our study therefore identifies new SPR-associated factors that could play a role in refining and updating Brucella taxonomic schemes and provides resources for further detailed analysis of mechanism for Brucella phage resistance.

Brucellosis awareness and knowledge in communities worldwide: A systematic review and meta-analysis of 79 observational studies

BACKGROUND

Brucellosis is regarded as a major zoonotic infection worldwide. Awareness and knowledge of brucellosis among occupational workers is considered an important aspect of brucellosis control in both humans and animals. The aim of this study was to explore the distributions of the pooled awareness level and the knowledge level of the disease worldwide.

METHODS

A meta-analysis was carried out to obtain pooled brucellosis awareness levels and knowledge levels of respondents regarding the zoonotic nature of brucellosis, mode of brucellosis transmission, and brucellosis symptoms in animals and humans. The analysis was conducted and reported in accordance with the Preferred Reporting Items for Systematic Review and Meta-analyses guidelines.

RESULTS

A total of seventy-nine original articles reporting the brucellosis awareness levels of in populations from 22 countries were assessed. The total pooled awareness level of brucellosis was 55.5%, and the pooled awareness levels regarding the zoonotic nature of brucellosis, mode of brucellosis transmission, signs of human brucellosis and signs of animal brucellosis were 37.6%, 35.9%, 41.6%, and 28.4% respectively. The pooled awareness level was higher than the brucellosis-related knowledge level. Subgroup analyses showed that no obvious differences in brucellosis awareness levels between high-risk populations in Asia and Africa. Health workers (including human health workers and veterinarians) had the greatest overall awareness and knowledge of human brucellosis. The overall awareness levels and knowledge levels of livestock owners (farmers) and herders were higher than those of dairy farmers and abattoir workers. In addition, awareness and knowledge levels were higher among people who were involved in bovine, caprine and ovine animal production or in caprine and ovine animal production than among people who were involved in only bovine animal production.

CONCLUSIONS

Insufficient awareness and knowledge of brucellosis were observed in the original studies conducted mainly in Asia and Africa. Interventions to improve public knowledge about brucellosis are urgently needed.

Serological and histopathological investigation of brucellosis in cattle in Medea region, Northern Algeria

AIM

This study was performed to determine the prevalence of bovine brucellosis in Medea region, Northern Algeria.

MATERIALS AND METHODS

The study was carried out on 495 non-vaccinated cattle, of which 280 (30 males and 250 females) belonged to 57 cattle farms and 215 cows were sampled at abattoirs of Medea. Sera collected from the cattle were tested using the Rose Bengal test and confirmed by histopathological analysis.

RESULTS

Serological examination revealed that 7/57 farms (12.28%) were infected, of which 7/280 (2.5%) cattle were seropositive. The prevalence in females and males was 2.4% (6/250) and 3.33% (1/30), respectively. No significant difference has been observed between females and males. Older animals (≥8 years) were infected more. The prevalence of infection was 9.1%. Seroprevalence of Brucella infection in cows that have already had abortion was higher compared with non-aborted cows (4.34% and 2.20%, respectively). In abattoirs, a total of 25 (11.62%) seropositive cows were detected, and the histopathological analysis was positive in all these cows.

CONCLUSION

The study indicates that brucellosis indeed exists in cattle in Medea and shows that the meat of slaughtered cattle tested positive for brucellosis may constitute a real risk of transmission to both butchery personnel and consumers, which requires that the meat of infected animals should be analyzed before being marketed.

The good, the bad and the ugly: framing debates on nature in a One Health community

Originating in medical and veterinary spheres, the One Health concept stands as an open call for collaboration also between these disciplines or professions and those of environmental and social science. However, the communities of practice in question show uneasy or under-developed collaborations, due to a variety of factors. We argue that an important factor is the way issues are raised and questions are formulated, i.e., their framing. Based on complementary perspectives on health and knowledge, this overview provides an inter- and trans-disciplinary analysis of the role of the framing of « nature » in One Health discourses as a barrier or a facilitator to collaboration, as revealed by the scientific literature. We find that the lack of reflection by scientists about the framing under which they operate appears as a major factor of misunderstanding between disciplines, and a barrier for inter- and trans-disciplinary solutions to improve management of health risks and benefits. Hence, to build such solutions, framing will have to be a conscious and repeated step in the process, acknowledging and explaining the diversity of viewpoints and values. The interdisciplinary dialogues inherent in this process promote translation between scientific domains, policy-makers and citizens, with a critical but pluralistic recourse to various framings of health risks and benefits associated with nature, and a deep awareness of their practical and ethical consequences.

Risk factors for new bovine brucellosis infections in Colombian herds

BACKGROUND

Bovine brucellosis is a zoonotic disease that causes substantial economic losses and has a strong impact on public health. The main objective of this paper is to determine the risk factors for new infections of Brucella abortus on Colombian cattle farms previously certified as being free of brucellosis. A case-control study was conducted by comparing 98 cases (farms certified as brucellosis-free for three or more years but became infected) with 93 controls (farms that remained brucellosis-free during at least the previous three years). The farms were matched by herd size and geographical location (municipality). Information was obtained via a questionnaire completed by veterinary officers through a personal interview with the herd owners.

RESULTS

Two-thirds of the herds (67%) were dairy herds, 16% were beef herds, and 17% were dual-purpose (beef and milk) herds. After exploratory univariate analysis, all explanatory variables with a p-value of ≤0.20 were included in a logistic regression model using the forward stepwise method to select the model with the best goodness of fit. The significant risk factors were the replacement of animals from farms not certified as brucellosis-free compared to replacement from certified brucellosis-free farms (OR = 4.84, p-value < 0.001) and beef cattle farms compared to dairy cattle farms (OR = 3.61, p-value = 0.017). When herds with and without artificial insemination were compared, it was observed that farms that used natural breeding with bulls from non-certified herds had a higher risk than farms using artificial insemination (OR = 2.45, p-value = 0.037), but when the bulls came from brucellosis-free farms, farms with natural breeding were less affected (OR = 0.30, p-value = 0.004) than farms using artificial insemination, whether with frozen semen from certified brucellosis-free herds or fresh semen from uncontrolled herds. The latter is commonly sold to neighbouring farms.

CONCLUSIONS

The government should make efforts to inform farmers about the risks involved in the introduction of semen and replacement heifers from farms that are not certified as brucellosis-free and to establish measures to control these practices.