Unexpected Brucella suis biovar 2 Infection in a dairy cow, Belgium

Isolation and molecular confirmation of Brucella suis biovar 2 from slaughtered pigs: an unanticipated biovar from domestic pigs in Egypt

Background

Brucella suis is a zoonotic pathogen with a serious impact on public health and the pig industry worldwide. Information regarding B. suis in pigs in Egypt is scarce. This study aimed to investigate the prevalence of B. suis in slaughtered domestic pigs at El-Basatin abattoir in Cairo, Egypt. A total of 1,116 domestic pigs slaughtered in 2020 were sampled for Brucella isolation and identification. Identified Brucella isolates were molecularly confirmed at species, and biovar levels using Bruce ladder PCR and Suis ladder multiplex PCR. Additionally, high-risk practices of 16 abattoir workers (4 veterinarians, 10 butchering and evisceration workers, and 2 scalding workers) were investigated using a pre-piloted structured questionnaire.

Results

Brucella isolates were recovered from 1.3% of examined pigs (n = 14) at consistently low rates (1.1—2.9%) across the year of sampling from February to December 2020. All isolates were confirmed as B. suis biovar (bv) 2. Remarkably, 92.9% (13/14) of isolates showed atypical ability to produce H₂S and hence were considered as B. suis bv2 atypical phenotype. The prevalence was higher in males (1.8%) than in females (0.9). However, this difference was not significant (Odds ratio = 1.9; CI 95% 0.7 – 5.7; P = 0.2). No detectable pathological lesions were associated with B. suis bv2 infection in examined pigs. All strains were isolated from cervical lymph nodes, highlighting a potential oral transmission. High-risk practices were recorded among swine abattoir workers in this study: 75% do not wear gloves or disinfect their knives daily, and 18.8% were willing to work with open wound injuries.

Conclusions

To the best of our knowledge, this is the first isolation of B. suis bv2 in Egypt. Detection of H₂S producing B. suis bv2 atypical phenotype is alarming as it may result in misinterpretation of these isolates as highly human pathogenic B. suis bv1 in Egypt and possibly elsewhere. Further epidemiological tracing studies are crucial for the detection of the origin of this biovar. Including pigs in the national surveillance program of brucellosis, and an education program for swine abattoir workers about occupational risk of B. suis is a need in Egypt.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-022-03332-2.

Identification of candidate genes associated with bacterial and viral infections in wild boars hunted in Tuscany (Italy)

Wild boar (Sus scrofa L.) is one of the large mammals most spread worldwide, highly adaptable, and its population rapidly increased in many areas in Europe, including Italy, where Tuscany is considered particularly suitable for wild boar. Wild boars are potential hosts for different etiological agents, such as Brucella spp., Leptospira spp. and Pseudorabies virus and they can contribute to maintain and/or to disseminate some bacterial or viral pathogens to humans and domestic animals, above all-in free-range farms. In order to identify hypothetical genomic regions associated with these infection diseases, 96 samples of wild boars hunted in Tuscany during the 2018-2019 and 2019-2020 hunting seasons were considered. Diagnosis was achieved by serological tests and 42 Pseudorabies, 31 Leptospira and 15 Brucella positive animals were identified. All animals were genotyped with Geneseek Genomic Profiler Porcine HD (70 k) and a genome-wide scan was then performed. Significant markers were highlighted for Pseudorabies (two SNPs), Brucella (seven SNPs), and Leptospira (four SNPs) and they were located within, or nearby, 29 annotated genes on chromosome 6, 9, 12, 13, 14 and 18. Eight genes are implicated in viral (SEC14L1, JMJD6, SRSF2, TMPRSS2, MX1, MX2) or bacterial (COL8A1, SPIRE1) infections, seven genes (MFSD11, METTL23, CTTNBP2, BACE2, IMPA2, MPPE1 and GNAL) are involved in mental disorders and one gene (MGAT5B) is related to the Golgi complex. Results presented here provide interesting starting points for future research, validation studies and fine mapping of candidate genes involved in bacterial and viral infections in wild boar.

Emerging diversity and ongoing expansion of the genus Brucella

Remarkable genetic diversity and breadth of host species has been uncovered in the Brucella genus over the past decade, fundamentally changing our concept of what it means to be a Brucella. From ocean fishes and marine mammals, to pond dwelling amphibians, forest foxes, desert rodents, and cave-dwelling bats, Brucella have revealed a variety of previously unknown niches. Classical microbiological techniques have been able to help us classify many of these new strains but at times have limited our ability to see the true relationships among or within species. The closest relatives of Brucella are soil bacteria and the adaptations of Brucella spp. to live intracellularly suggest that the genus has evolved to live in vertebrate hosts. Several recently discovered species appear to have phenotypes that are intermediate between soil bacteria and core Brucella, suggesting that they may represent ancestral traits that were subsequently lost in the traditional species. Remarkably, the broad relationships among Brucella species using a variety of sequence and fragment-based approaches have been upheld when using comparative genomics with whole genomes. Nonetheless, genomes are required for fine-scale resolution of many of the relationships and for understanding the evolutionary history of the genus. We expect that the coming decades will reveal many more hosts and previously unknown diversity in a wide range of environments.

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.

Genital Brucella suis Biovar 2 Infection of Wild Boar (Sus scrofa) Hunted in Tuscany (Italy)

Brucellosis is a zoonosis caused by different Brucella species. Wild boar (Sus scrofa) could be infected by some species and represents an important reservoir, especially for B. suis biovar 2. This study aimed to investigate the prevalence of Brucella spp. by serological and molecular assays in wild boar hunted in Tuscany (Italy) during two hunting seasons. From 287 animals, sera, lymph nodes, livers, spleens, and reproductive system organs were collected. Within sera, 16 (5.74%) were positive to both rose bengal test (RBT) and complement fixation test (CFT), with titres ranging from 1:4 to 1:16 (corresponding to 20 and 80 ICFTU/mL, respectively). Brucella spp. DNA was detected in four lymph nodes (1.40%), five epididymides (1.74%), and one fetus pool (2.22%). All positive PCR samples belonged to Brucella suis biovar 2. The results of this investigation confirmed that wild boar represents a host for B.suis biovar. 2 and plays an important role in the epidemiology of brucellosis in central Italy. Additionally, epididymis localization confirms the possible venereal transmission.

Prevalence, Virulence and Antimicrobial Susceptibility of Salmonella spp., Yersinia enterocolitica and Listeria monocytogenes in European Wild Boar (Sus scrofa) Hunted in Tuscany (Central Italy)

Wild boar is an animal the population of which constantly increases in Europe. This animal plays an important role as a reservoir for several pathogens, including three of the most important zoonoses: salmonellosis, yersiniosis and listeriosis. The aim of this investigation was to evaluate the occurrence of antimicrobial-resistant and virulence factor genes of Salmonella spp., Yersinia enterocolitica and Listeria monocytogenes isolated from wild boar in Tuscany (Central Italy). During two consequent hunting seasons (2018/2019 and 2019/2020), rectal swabs, spleens and livers were collected from 287 hunted wild boar to isolate strains. Each isolate was tested to investigate its antimicrobial resistance and to detect virulence factor genes by PCR. Eighteen Salmonella strains (6.27%) were isolated. Of these, 66.7% were resistant to streptomycin, 13.4% to cephalothin, 6.67% to imipenem and one isolate (6.67%) was resistant simultaneously to five antimicrobials. Moreover, the most detected genes were sopE (73.4%), pipB (66.7%), sodCI (53.3%), spvR and spvC (46.7%). In total, 54 (17.8%) Yersinia enterocolitica were isolated; of them, 26 (48.1%), 9 (16.7%), 17 (31.5%), 1 (1.85%) and 1 (1.85%) belonged to biotypes 1, 2, 3, 4 and 5, respectively. All strains (100%) demonstrated resistance to cephalothin and 70.4% to amoxicillin-clavulanic acid, 55.6% to ampicillin, and 37.0% to cefoxitin. Additionally, the most detected genes were ystA (25.9%), inv (24.1%), ail (22.2%), ystB (18.5%) and virF (14.8%). Finally, only one Listeriamonocytogenes isolate (0.35%) was obtained, belonging to serogroup IVb, serovar 4b, and it was found to be resistant to cefoxitin, cefotaxime and nalidixic acid. The results highlighted the role of wild boar as a carrier for pathogenic and antimicrobial-resistant Salmonella spp., Yersinia enterocolitica and Listeria monocytogens, representing a possible reservoir for domestic animals and human pathogens.

Monitoring results of wild boar (Sus scrofa) in The Netherlands: analyses of serological results and the first identification of Brucella suis biovar 2

In Europe, wild boar populations pose an increasing risk for livestock and humans due to the transmission of animal and zoonotic infectious diseases, such as African swine fever and brucellosis. Brucella suis is widespread among wild boar in many European countries. In The Netherlands the prevalence of B. suis among wild boar has not been investigated so far, despite the high number of pig farms and the growing wild boar population. The Netherlands has a Brucella-free status for the livestock species. The objective of this study is to investigate the presence and distribution of B. suis in wild boars in The Netherlands and to assess the value of the different laboratory tests available for testing wild boars. A total of 2057 sera and 180 tonsils of wild boar were collected between 2010 and 2015. The sera were tested for Brucella antibodies and the tonsils were tested for Brucella spp. B. suis biovar 2 was detected by MLVA/MLST and culture in wild boar from the province of Limburg, while seropositive wild boar were obtained from the provinces of Limburg, Noord Brabant and Gelderland suggesting the northwards spread of B. suis biovar 2. In this paper, we describe the first isolation of B. suis biovar 2 in wild boar in The Netherlands.

Prevalence and Spatial Distribution of Animal Brucellosis in Central Punjab, Pakistan

Brucellosis is an important zoonotic disease of animals and humans caused by bacteria of the genus Brucella. Brucellae are Gram-negative intracellular bacteria which infect a wide variety of animals including goats, sheep, buffaloes, cows, pigs, and wildlife. The objectives of this study were to determine the seroprevalence and spatial distribution of brucellosis in Central Punjab, Pakistan. A total of 1083 blood samples of goats, sheep, buffaloes, and cows were collected from 38 villages of four districts (Kasur, Faisalabad, Lahore, and Okara) of Punjab, Pakistan, and screened for brucellosis by Rose Bengal Plate test (RBPT) and PCR confirmed. Epidemiological, demographic data and GPS coordinates for every sample were collected. By using interpolation of the Aeronautical Reconnaissance Coverage Geographic Information System (Arc GIS), a surface plot was generated applying inverse distance weight (IDW). It was found that 35 (3.23%) serum samples were positive for brucellosis. In eight (61.5%), six (75%), seven (87.5%), and eight (89%) villages, positive goats, sheep, buffaloes, and cattle were detected, respectively. In general, older animals are more often positive for brucellosis. In goats bucks were more often RBPT positive than females while in sheep, buffaloes, and cattle more females were positive. The spatial distribution of brucellosis shows that it is widely distributed in the western region of the study area in goats and in the South-West region in sheep. Similarly, for buffaloes it is restricted to the south-east and north-west regions, and in cattle brucellosis is present in western region of study area only. Reflected by this study, brucellosis poses a risk for livestock in developing countries due to lack of awareness by officials, owners, and consumers, and control measures are missing. A risk map of brucellosis was generated to develop effective strategies for awareness rising and to improve the quality of control programs in Pakistan.

Serological Survey on Bacterial and Viral Pathogens in Wild Boars Hunted in Tuscany

Wild boar (Sus scrofa) is one of the large mammals most spread worldwide, including Italy. This animal is highly adaptable, and its population has rapidly increased in many areas in Europe. Central Italy, as well as Tuscany region, is an area particularly suitable for wild boar. In order to verify the role of this animal species in the epidemiology of some important infectious diseases for livestock and humans, a seroepidemiological survey on Brucella spp., Leptospira spp., Mycoplasma hyopneumoniae, Pseudorabies virus (PrV), and Hepatitis E virus (HEV) has been performed on 374 sera collected from wild boar during 2015/2016 and 2016/2017 hunting seasons. Overall, 2 out of 374 sera (0.53%) tested positive to Brucella spp., 33 out of 374 sera (8.82%) tested positive for Leptospira spp., while 79 out of 374 (21.12%) were positive for M. hyopneumoniae. Considering viral pathogens, serology indicated that 107 out of 374 (28.60%) samples scored positive for PrV, while 186 out of 374 (49.73%) for HEV. This investigation indicated that wild boar free ranging in the study area are potential hosts for different etiological agents. This animal could contribute to maintaining and/or disseminating some bacterial or viral pathogens to humans (especially hunters) and domestic animals, especially in free range farms.

A Multi-Pathogen Screening of Captive Reindeer (Rangifer tarandus) in Germany Based on Serological and Molecular Assays

Captive reindeer in German zoos and wildlife parks live outside their natural geographic range and are exposed to a variety of viral, bacterial and protozoan pathogens, some host-specific and some which they are not exposed to in their native habitat. Reindeer blood samples and ticks collected in 2013 from 123 reindeer at 16 different zoological facilities were available from a previous study. The aims of this study were to assess the serological status of these animals with regards to various microorganisms as well as to test ticks (Ixodes ricinus) and blood samples for the presence of Anaplasma spp. DNA in order to evaluate the exposure of captive reindeer in Germany to a variety of pathogens. A total of 119 or 118 serum samples were screened (ELISA) and antibodies were detected (seropositive/tested, prevalence, confidence interval) against alphaherpesvirus (24/119, 20.3%, CI: 13.9–28.3), bluetongue virus (BTV; 4/119, 3.4%, CI: 1.0–8.7), malignant catarrhal fever related gammaherpesvirus (MCFV-related gammaherpesvirus; 7/119, 5.9%, CI: 2.7–11.9), pestivirus (5/118, 4.2%, CI: 1.6–9.8), Schmallenberg virus (SBV; 70/118, 59.3%, CI: 50.3–67.8), smooth Brucella spp. (1/118; 0.9%, CI: 0–5.1), Neospora caninum (5/118, 4.2%, CI: 1.6–9.8), and Toxoplasma gondii (62/119, 52.1%, CI: 43.2–60.9). These results suggested the exposure of reindeer to all tested pathogens. Moreover, real-time PCR for Anaplasma phagocytophilum targeting the partial msp2 gene was performed on DNA extracted from whole blood samples from reindeer (n = 123) and from ticks (n = 49) collected from 22 reindeer in seven different facilities. In addition to the real-time PCR, a semi-nested PCR for the partial groEL gene, and a nested PCR targeting the partial 16S rRNA gene were performed. DNA of A. phagocytophilum was detected in 17 reindeer (13.8%) and 15 ticks (30.6%). Three of the five reindeer with ticks having A. phagocytophilum DNA also had such DNA in blood. These results indicate that captive reindeer can be exposed to several ruminant pathogens that they hitherto had no known exposure to through their natural geographical distribution and habitats as shown for Culicoides-borne BTV and SBV. Further, captive reindeer may serve as reservoir hosts for pathogens circulating in local domestic, captive, and wild ruminant species and populations and arthropod vectors.

RECENT CHANGES IN INFECTIOUS DISEASES IN EUROPEAN WILDLIFE

Many infectious diseases originating from, or carried by, wildlife affect wildlife conservation and biodiversity, livestock health, or human health. We provide an update on changes in the epidemiology of 25 selected infectious, wildlife-related diseases in Europe (from 2010-16) that had an impact, or may have a future impact, on the health of wildlife, livestock, and humans. These pathogens were selected based on their: 1) identification in recent Europe-wide projects as important surveillance targets, 2) inclusion in European Union legislation as pathogens requiring obligatory surveillance, 3) presence in recent literature on wildlife-related diseases in Europe since 2010, 4) inclusion in key pathogen lists released by the Office International des Epizooties, 5) identification in conference presentations and informal discussions on a group email list by a European network of wildlife disease scientists from the European Wildlife Disease Association, or 6) identification as pathogens with changes in their epidemiology during 2010-16. The wildlife pathogens or diseases included in this review are: avian influenza virus, seal influenza virus, lagoviruses, rabies virus, bat lyssaviruses, filoviruses, canine distemper virus, morbilliviruses in aquatic mammals, bluetongue virus, West Nile virus, hantaviruses, Schmallenberg virus, Crimean-Congo hemorrhagic fever virus, African swine fever virus, amphibian ranavirus, hepatitis E virus, bovine tuberculosis ( Mycobacterium bovis), tularemia ( Francisella tularensis), brucellosis ( Brucella spp.), salmonellosis ( Salmonella spp.), Coxiella burnetii, chytridiomycosis, Echinococcus multilocularis, Leishmania infantum, and chronic wasting disease. Further work is needed to identify all of the key drivers of disease change and emergence, as they appear to be influencing the incidence and spread of these pathogens in Europe. We present a summary of these recent changes during 2010-16 to discuss possible commonalities and drivers of disease change and to identify directions for future work on wildlife-related diseases in Europe. Many of the pathogens are entering Europe from other continents while others are expanding their ranges inside and beyond Europe. Surveillance for these wildlife-related diseases at a continental scale is therefore important for planet-wide assessment, awareness of, and preparedness for the risks they may pose to wildlife, domestic animal, and human health.

A Serological Survey on Swine Brucellosis Using Standard Procedures, Dot Blot, and Western Blot in Finisher Pigs in Central-North Italy

In recent years, Brucella suis has been sporadically reported in Italy in domestic and wild swine. Since standard serological tests can determine false positive results, the development of alternative tests with improved sensitivity and specificity is rather essential. We analyzed 1212 sera collected at slaughterhouse from healthy pigs belonging to 62 farms of North-Central Italy. Sera were tested by Rose Bengal Test, Complement Fixation Test, and subsequently by a Dot Blot (DB) and Western Blot assays (WB). Only one serum resulted positive to all tests, indicating that swine brucellosis has a very limited spread. DB and WB could represent a support to the available serological tests; however, further studies to validate these tests are needed. In the presence of reemerging diseases, a prompt and continuous monitoring design is necessary to acquire epidemiological information for the subsequent application of specific health emergency plans.

Brucella spp. at the Wildlife-Livestock Interface: An Evolutionary Trajectory through a Livestock-to-Wildlife "Host Jump"?

Brucella infections in wildlife have gained a lot of interest from the scientific community and different stakeholders. These interests are often different and sometimes conflicting. As a result, different management perspectives and aims have been implemented (One Health, public health, veterinary public health, maintenance of a brucellosis free status in livestock, sustainable wildlife harvesting by hunters, wildlife and environmental health). When addressing Brucella infection in wildlife, the most important features of Brucella infection should be considered and the following questions need to be answered: (1) Is Brucella infection a result of a spillover from livestock or is it a sustainable infection in one or more wildlife host species? (2) Did the epidemiological situation of Brucella infection in wildlife change over time and, if so, what are the main drivers of change and does it impact the wildlife population dynamics? (3) Does Brucella infection in wildlife represent a reservoir of Brucella strains for livestock? (4) Is Brucella infection in wildlife of zoonotic concern? These questions point to the fundamental biological question of how animal (domestic and wildlife)/Brucella spp. partnerships are established. Will we be able to decipher an evolutionary trajectory through a livestock-to-wildlife "host jump"? Whole genome sequencing and new "omics" techniques will help in deciphering the molecular basis of Brucella host preference and open new avenues in brucellosis management aimed at preventing opportunities for Brucella host jumps.

Rural veterinarian's perception and practices in terms of biosecurity across three European countries

The implementation of biosecurity measures in the animal health and production context is quite broad and aims at limiting the risk of introduction and spread of diseases. Veterinarians play a major role in biosecurity as key informants on the subject for cattle holders, key players in terms of disease prevention/control and eradication programs, as well as key risk factor in terms of disease dissemination. Many biosecurity studies have highlighted professional visitors such as veterinary practitioners as representing a high-risk factor in terms of disease introduction in animal facilities but, to date, very few studies have focused on the implementation level of biosecurity measures by veterinarians. An online survey was implemented in three European countries (Belgium, France and Spain) to assess the behaviour of rural veterinarians towards biosecurity, as well as their implementation level of the biosecurity measures. A descriptive analysis of data and a scoring system were applied to assess the implementation level of measures. The influence of different factors on the implementation level of biosecurity measures was investigated through a negative binomial regression model. The study identified different strengths, weaknesses, possible constraints and solutions in terms of veterinary perspectives. Veterinarians are considered as key informants by the farmers and could therefore play a more active role in terms of guidance and improvement of biosecurity at farm level. Based on the survey outcomes, two factors seemed to influence significantly the implementation level of measures: the country where he/she practices and the veterinarian's perception level of biosecurity. The biosecurity stages with the lowest application level, therefore representing the biggest threats, were bio-exclusion (increasing the risk of disease introduction) and biocontainment (increasing the risk of inter-herd transmission).

Assessment of listing and categorisation of animal diseases within the framework of the Animal Health Law (Regulation (EU) No 2016/429): infection with Brucella abortus, B. melitensis and B. suis

The infection with Brucella abortus, Brucella melitensis and Brucella suis has been assessed according to the criteria of the Animal Health Law (AHL), in particular criteria of Article 7 on disease profile and impacts, Article 5 on the eligibility of the infection with B. abortus, B. melitensis and B. suis to be listed, Article 9 for the categorisation of the infection with B. abortus, B. melitensis and B. suis according to disease prevention and control rules as in Annex IV and Article 8 on the list of animal species related to the infection with B. abortus, B. melitensis and B. suis. The assessment has been performed following a methodology composed of information collection and compilation, expert judgement on each criterion at individual and, if no consensus was reached before, also at collective level. The output is composed of the categorical answer, and for the questions where no consensus was reached, the different supporting views are reported. Details on the methodology used for this assessment are explained in a separate opinion. According to the assessment performed, the infection with B. abortus, B. melitensis and B. suis can be considered eligible to be listed for Union intervention as laid down in Article 5(3) of the AHL. The disease complies with the criteria as in Sections 2, 3, 4 and 5 of Annex IV of the AHL, for the application of the disease prevention and control rules referred to in points (b), (c), (d) and (e) of Article 9(1). The animal species to be listed for the infection with B. abortus, B. melitensis and B. suis according to Article 8(3) criteria are several mammal species, as indicated in the present opinion.

Seroprevalence and risk factors associated with bovine brucellosis in the Potohar Plateau, Pakistan

Background

The seroprevalence and risk factors of bovine brucellosis were studied at animal and herd level using a combination of culture, serological and molecular methods. The study was conducted in 253 randomly selected cattle herds of the Potohar plateau, Pakistan from which a total of 2709 serum (1462 cattle and 1247 buffaloes) and 2330 milk (1168 cattle and 1162 buffaloes) samples were collected. Data on risk factors associated with seroprevalence of brucellosis were collected through interviews using questionnaires. Univariable and multivariable random effects logistic regression models were used for identifying important risk factors at animal and herd levels.

Results

One hundred and seventy (6.3%) samples and 47 (18.6%) herds were seropositive for brucellosis by Rose Bengal Plate test. Variations in seroprevalence were observed across the different sampling sites. At animal level, sex, species and stock replacement were found to be potential risk factors for brucellosis. At herd level, herd size (≥9 animals) and insemination method used were important risk factors. The presence of Brucella DNA was confirmed with a real-time polymerase chain reaction assay (qRT-PCR) in 52.4% out of 170 serological positive samples. In total, 156 (6.7%) milk samples were positive by milk ring test. B. abortus biovar 1 was cultured from 5 positive milk samples.

Conclusion

This study shows that the seroprevalence of bovine brucellosis is high in some regions in Pakistan. Prevalence was associated with herd size, abortion history, insemination methods used, age, sex and stock replacement methods. The infected animal may act as source of infection for other animals and for humans. The development of control strategies for bovine brucellosis through implementation of continuous surveillance and education programs in Pakistan is warranted.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-017-2394-2) contains supplementary material, which is available to authorized users.

Activation of bovine neutrophils by Brucella spp

Brucellosis is a globally important zoonotic infectious disease caused by gram negative bacteria of the genus Brucella. While many species of Brucella exist, Brucella melitensis, Brucella abortus, and Brucella suis are the most common pathogens of humans and livestock. The virulence of Brucella is largely influenced by its ability to evade host factors, including phagocytic killing mechanisms, which are critical for the host response to infection. The aim of this study was to characterize the bovine neutrophil response to virulent Brucella spp. Here, we found that virulent strains of smooth B. abortus, B. melitensis, B. suis, and virulent, rough, strains of Brucella canis possess similar abilities to resist killing by resting, or IFN-γ-activated, bovine neutrophils. Bovine neutrophils responded to infection with a time-dependent oxidative burst that varied little between Brucella spp. Inhibition of TAK1, or SYK kinase blunted the oxidative burst of neutrophils in response to Brucella infection. Interestingly, Brucella spp. did not induce robust death of bovine neutrophils. These results indicate that bovine neutrophils respond similarly to virulent Brucella spp. In addition, virulent Brucella spp., including naturally rough strains of B. canis, have a conserved ability to resist killing by bovine neutrophils.

The first report of Brucella suis biovar 1 isolation in human in Turkey

BACKGROUND

Brucella melitensis and B. abortus are the species generally isolated from human samples in Turkey. Several studies have also demonstrated the presence of antibodies against B. canis.

CASE REPORT AND STUDY

Brucella spp. was isolated from blood culture from a 35-year-old male with clinical signs and symptoms of acute meningitis, including fever lasting for 1 week. Multiplex PCR demonstrated B. suis, and biochemical features indicated biovar 1.

CONCLUSIONS

This report is the first emphasizing that B. suis should be considered among the causes of brucellosis in Turkey.

Advancement of knowledge of Brucella over the past 50 years

Fifty years ago, bacteria in the genus Brucella were known to cause infertility and reproductive losses. At that time, the genus was considered to contain only 3 species: Brucella abortus, Brucella melitensis, and Brucella suis. Since the early 1960s, at least 7 new species have been identified as belonging to the Brucella genus (Brucella canis, Brucella ceti, Brucella inopinata, Brucella microti, Brucella neotomae, Brucella ovis, and Brucella pinnipedialis) with several additional new species under consideration for inclusion. Although molecular studies have found such high homology that some authors have proposed that all Brucella are actually 1 species, the epidemiologic and diagnostic benefits for separating the genus based on phenotypic characteristics are more compelling. Although pathogenic Brucella spp have preferred reservoir hosts, their ability to infect numerous mammalian hosts has been increasingly documented. The maintenance of infection in new reservoir hosts, such as wildlife, has become an issue for both public health and animal health regulatory personnel. Since the 1960s, new information on how Brucella enters host cells and modifies their intracellular environment has been gained. Although the pathogenesis and histologic lesions of B. abortus, B. melitensis, and B. suis in their preferred hosts have not changed, additional knowledge on the pathology of these brucellae in new hosts, or of new species of Brucella in their preferred hosts, has been obtained. To this day, brucellosis remains a significant human zoonosis that is emerging or reemerging in many parts of the world.