Imported human brucellosis in Belgium: Bio and molecular typing of bacterial isolates, 1996-2015

Determination and Characterization of (Novel) Circulating Strains of Brucella sp. Within the National Bovine Brucellosis Control Program in Ecuador

Brucellosis is a zoonotic disease caused by bacteria of the Brucella species. This infectious disease represents a significant public health and economic challenge in many regions of the world, including Ecuador. Brucella abortus is the most common species in cattle. Transmission mainly occurs through direct contact with secretions, aborted fetuses, or contaminated reproductive fluids. In this study, to evaluate the circulating strains of Brucella in continental Ecuador, Brucella strains were cultured and isolated from retromammary lymph nodes and milk samples collected over the past three years from six Ecuadorian provinces within the National Brucellosis Program of Ecuador. Brucella cultures were performed on two specific media, CITA and Farrell, followed by molecular identification using PCR and multiple-locus variable-number tandem repeat analysis 16 (MLVA-16) diagnostic techniques. Out of a total of 25 retromammary lymph nodes collected at slaughterhouses and 50 milk samples obtained from serologically positive animals on farms, Brucella was isolated from 35 milk samples and 19 retromammary lymph node samples and identified as Brucella abortus by PCR. Subsequent MLVA-16 genotyping enabled accurate discrimination among the Brucella strains present in Ecuador. This study confirmed the presence of Brucella abortus strains of biovars 1 and 4 and, for the first time, detected the presence of biovar 2 in Ecuador. The isolation and accurate detection of Brucella, along with the implementation of advanced genotyping techniques, such as MLVA, are crucial for future epidemiological studies, outbreak tracing, and the development of control strategies to mitigate animal and human infection in Ecuador.

Molecular epidemiology of brucellosis in Asia: insights from genotyping analyses

Brucellosis infects humans and animals worldwide but is particularly prevalent in Asia. In many Asian countries, molecular diagnostic tools for accurate molecular diagnostics and molecular epidemiology are lacking. Nonetheless, some countries have conducted in-depth molecular epidemiological studies. The objective of this study was to reveal the genetic relationships, geographic origins, and distributions of Brucella strains across Asia for two primary species, B. abortus and B. melitensis. For this, we systematically searched genotyping data from published studies on the molecular epidemiology of Brucella species for both humans and livestock in Asia. We used data from multilocus sequence typing (MLST), multiple-locus variable-number tandem repeat analysis (MLVA), and whole genome sequencing analysis of Brucella strains. We also analyzed the MLVA genotypes of 129 B. abortus isolates and 242 B. melitensis isolates with known origins in Asia from an online MLVA database using MLVA-11 data in minimum spanning trees and MLVA-16 data in neighbor-joining trees. We found that the B. melitensis East Mediterranean lineage is predominant across the continent, with only a small number of samples from the Africa and Americas lineages, and none from the West Mediterranean lineage. The "abortus C" genotype was the most common group of B. abortus in Asia, with limited genetic variation for this species. Several studies also reported that Near Eastern countries frequently encounter human brucellosis cases of B. abortus from genotypes 42 and 43. Our study highlights the inconsistent collection of genetic data for Brucella species across Asia and a need for more extensive sampling in most countries. Finally, a consistent nomenclature is necessary to define various groupings of strains within a lineage (i.e., clade) so uniform terminology should denote particular genetic groups that are understood by all researchers.

Seroprevalence of Brucellosis in Patients Having Complained of Joint Pain: A Case Control

BACKGROUND

Brucellosis is a neglected zoonotic disease affecting humans and animals.

OBJECTIVES

This study aimed to estimate the seroprevalence of brucellosis in patients with joint pain.

METHODS

A total of 200 participants aged from 7 to 86 years were involved in this study. Blood samples were collected from all the participants for two years, from September 2019 to September 2021, and screened for Brucella using anti-brucella IgM ELISA and anti-brucella IgG ELISA antibodies. A questionnaire was used to collect data on socio-demographic characteristics and human brucellosis-related risk factors.

RESULTS

Human Brucella seroprevalence was 19 (9.5%) for Brucella IgM ELISA and 23 (11.5%) for Brucella IgG ELISA. The sensitivity for Brucella IgM ELISA and Brucella IgG ELISA was 65.2% and 31.6%, respectively, while the specificity was 44.1% for Brucella IgM ELISA and 77.9% for Brucella IgG ELISA. All blood culture reports of all patients were negative. The principal presentation was the observable symptoms of human brucellosis: fever, headache, chills, myalgia, and Joint pain.

CONCLUSION

Risk factors like consumption of raw milk or their products were found to be the most important for Brucella infection, so the awareness or information of risk factors and the modes of transmission is much more important in control and prevention programs. General awareness about clinical symptoms should be increased, which will improve proper diagnosis and will be helpful in early treatment. An ELISA test should be considered for diagnosing brucellosis in both acute and chronic phases.

Identification and molecular characterization of Brucella abortus and Brucella melitensis isolated from milk in cattle in Azerbaijan

BACKGROUND

Azerbaijan currently ranks thirteenth in global incidence of human brucellosis, with an estimated annual incidence through 2000 at over 50 cases per million. Brucella melitensis has been isolated from patients and is thought to have been acquired through contact with small ruminants or as a foodborne infection. To reduce the burden of human brucellosis, the Azerbaijani government began in 2002, a nationwide vaccination control campaign in small ruminants. There is serological evidence of bovine brucellosis (presumably due to Brucella abortus) in Azerbaijan, but no prevalence estimates were available when this study started in March 2017. The aim of this study was to isolate and identify Brucella spp. from cow milk in the Ganja region, where brucellosis takes a heavy toll on humans and livestock.

RESULTS

Blood and milk samples were collected from cows (n = 1075) in early lactation (up to 90-days) in farms that had a history of previous positive serological results and abortions. Twenty-two out of 57 milk samples collected from seropositive cows, showed growth on Farrell's media, when incubated with 5% CO₂. Eight additional milk samples showed growth in the absence of CO₂. The classical biotyping classified them as Brucella abortus (22) and Brucella melitensis (8). RT-PCR confirmed that strains belonged to the genus Brucella. MLVA profiles were obtained for DNA extracted from two B. abortus and six B. melitensis strains. While the B. abortus genetic profile was described in the MLVA database, matching the profile of B. abortus strains isolated in East Europe, Central Asia and China, we found a new genotype for the B. melitensis strains isolated in Azerbaijan, clustering with strains belonging to the American clade, rarely identified in the region.

CONCLUSION

Despite the implementation of the vaccination program in small ruminants, our results suggest that spill-over events of B. melitensis from small ruminants to cattle have occurred. However, cattle are likely to be primarily infected with B. abortus, which warranted the implementation of a bovine brucellosis program. Such a program started in fall 2017. In the Ganja region, cattle should be considered as a potential source of B. abortus and B. melitensis for humans.

Genetic Characterization of Brucella spp.: Whole Genome Sequencing-Based Approach for the Determination of Multiple Locus Variable Number Tandem Repeat Profiles

Brucellosis is an important zoonosis that is emerging in some regions of the world, gaining increased relevance with the inclusion of the causing agent Brucella spp. in the class B bioterrorism group. Until now, multi-locus VNTR Analysis (MLVA) based on 16 loci has been considered as the gold standard for Brucella typing. However, this methodology is laborious, and, with the rampant release of Brucella genomes, the transition from the traditional MLVA to whole genome sequencing (WGS)-based typing is on course. Nevertheless, in order to avoid a disruptive transition with the loss of massive genetic data obtained throughout the last decade and considering that the transition timings will vary considerably among different countries, it is important to determine WGS-based MLVA alleles of the nowadays sequenced genomes. On this regard, we aimed to evaluate the performance of a Python script that had been previously developed for the rapid in silico extraction of the MLVA alleles, by comparing it to the PCR-based MLVA procedure over 83 strains from different Brucella species. The WGS-based MLVA approach detected 95.3% of all possible 1,328 hits (83 strains×16 loci) and showed an agreement rate with the PCR-based MLVA procedure of 96.4% for MLVA-16. According to our dataset, we suggest the use of a minimal depth of coverage of ~50x and a maximum number of ~200 contigs as guiding “boundaries” for the future application of the script. In conclusion, the evaluated script seems to be a very useful and robust tool for the in silico determination of MLVA profiles of Brucella strains, allowing retrospective and prospective molecular epidemiological studies, which are important for maintaining an active epidemiological surveillance of brucellosis.

A policy analysis of agenda-setting of Brucellosis in Iran using a multiple-stream framework: health policy and historical implications

Background

Brucellosis, a major zoonotic disease, is highly present in Iran, especially in Lorestan province. The aim of this study was to understand the issues related to Brucellosis utilizing the multiple streams framework.

Methods

A two-step method was adopted: 1) assessment of brucellosis-related documents and 2) interviews with stakeholders. As a first step, all documents related to Brucellosis were reviewed at provincial and national levels. Policy documentation on health issues included the consultation of guidelines, rules and regulations, websites, reports, books, guides, and conferences. These documents were collected by referring to specialized centers, institutions, and organizations. In the second step, semi-structured interviews were conducted to determine the burden of disease with actors and stakeholders involved with the brucellosis program in the Lorestan province. More in detail, physicians, healthcare workers, managers, policy- and decision-makers were selected for interviews.

Results

The problem stream was characterized by: 1) high prevalence of the disease, 2) traditional livestock production, 3) unsafe animal slaughtering, 4) centers for the sale and distribution of non-authorized dairy products, 5) raw milk and 6) traditional unsafe dairy products consumption, 7) incomplete livestock vaccination, 8) lack of knowledge of Brucellosis, 9) neighboring countries with high prevalence of Brucellosis, 10) lack of livestock quarantine, and 10) nomadic immigration. The policy stream was characterized by 1) primary healthcare networks, 2) guidelines, 3) medicines, insurance, and 4) diagnostic services. Finally, the political stream was characterized by: 1) support of the University of Medical Sciences, 2) sponsorship by the Ministry of Health and Medical Education, 3) Health transformation plan, and 4) Working Group on Health and Food Security in Lorestan.

Conclusion

This study examined the brucellosis-related agenda setting: if different issues are taken into consideration, it can be perceived as a health priority.

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.

Molecular characteristics of Brucella melitensis isolates from humans in Qinghai Province, China

BACKGROUND

The prevalence of human brucellosis in Qinghai Province of China has been increasing rapidly, with confirmed cases distributed across 31 counties. However, the epidemiology of brucellosis transmission has not been fully elucidated. To characterize the infecting strains isolated from humans, multiple-locus variable-number tandem repeats analysis (MLVA) and whole-genome single-nucleotide polymorphism (SNP)-based approaches were employed.

METHODS

Strains were isolated from two males blood cultures that were confirmed Brucella melitensis positive following biotyping and MLVA. Genomic DNA was extracted from these two strains, and whole-genome sequencing was performed. Next, SNP-based phylogenetic analysis was performed to compare the two strains to 94 B. melitensis strains (complete genome and draft genome) retrieved from online databases.

RESULTS

The two Brucella isolates were identified as B. melitensis biovar 3 (QH2019001 and QH2019005) following conventional biotyping and were found to have differences in their variable number tandem repeats (VNTRs) using MLVA-16. Phylogenetic examination assigned the 96 strains to five genotype groups, with QH2019001 and QH2019005 assigned to the same group, but different subgroups. Moreover, the QH2019005 strain was assigned to a new subgenotype, IIj, within genotype II. These findings were then combined to determine the geographic origin of the two Brucella strains.

CONCLUSIONS

Utilizing a whole-genome SNP-based approach enabled differences between the two B. melitensis strains to be more clearly resolved, and facilitated the elucidation of their different evolutionary histories. This approach also revealed that QH2019005 is a member of a new subgenotype (IIj) with an ancient origin in the eastern Mediterranean Sea.

Tracking the Origin of Austrian Human Brucellosis Cases Using Whole Genome Sequencing

Brucellosis is a zoonotic disease caused by Brucella spp. and a major concern for livestock. Most human cases are caused by B. melitensis and clinical presentation is usually a mild febrile illness. However, treatment failure is frequent and more severe complications can occur. In Austria, every human brucellosis is investigated to determine whether it was imported from endemic areas or is the sign of an undetected autochthonous transmission. For this study, 21 B. melitensis strains isolated in Austria between 2005 and 2019 were collected, 17 strains from 15 different patients and four strains from cattle. Whole genome sequencing combined with core-genome MLST analysis was used to characterize these strains. A cluster of seven isolates from 2018 (three human and four cattle isolates) was identified, with fewer than two allelic differences. They corresponded to the only Austrian B. melitensis outbreak that happened over the past 15 years. The other 12 Austrian brucellosis cases were single cases, and geographical origins were available for 8/12. Genomic data was used to locate probable geographical origins and compared with the results of the epidemiological investigations. Austrian strains were compared with 67 published B. melitensis sequences available on NCBI. The result of genomic analysis matched for 7/8 cases with documented conclusion of the epidemiological investigation. Genome analysis also pointed to the geographical origin for three of the four cases with missing epidemiological data. Strains from six cases were grouped together (<40 allelic differences) with 4/6 cases imported from the Balkans. Additional B. melitensis isolates from Serbian animals were analyzed and grouped with this branch, suggesting frequent importation from Balkan countries to Austria. Overall, this study highlights the specificities of human brucellosis in Austria. It also underlines the value of whole genome sequencing as a tool to investigate brucellosis cases, allowing to identify and investigate outbreaks but also to support epidemiological investigation of imported cases. However, the reliability of such methods depends on the number of strains for comparison, which can be challenging in low incidence countries. Increasing the availability of published sequences with documented geographical origins would help establishing genomic-based methods for investigating brucellosis cases.

Staggered enforcement of infection control and prevention measures following four consecutive potential laboratory exposures to imported Brucella melitensis

From 2015 until 2020, Brucella melitensis was isolated four times in our microbiology laboratory. All patients had travelled in endemic-areas. Immediately after the first occurrence, all laboratory staff were risk-stratified and preventive and protective measures were applied according to CDC guidelines. Nineteen workers were exposed and needed chemoprophylaxis and follow-up. At each subsequent occurrence, risk analysis was performed, and additional measures were implemented accordingly, leading to a progressive reduction of exposed staff members to none the fourth time. We describe here the additional measures that permitted this important exposure reduction.

Molecular investigation of infection sources and transmission chains of brucellosis in Zhejiang, China

In the present study, a total of 7793 samples from 5 different types of hosts were collected and tested, with a seroprevalence of 2.4% (184/7793). Although the seroprevalence of human and animal brucellosis is relatively low, numbers of human brucellosis cases reported have increased continuously from 2004 to 2018. A total of 118 Brucella strains containing 4 biotypes were obtained, including Brucella melitensis bv.1 (n = 8) and bv.3 (n = 106), Brucella abortus bv.3 (n = 3) and bv.7 (n = 1). Twenty-one shared MLVA-16 genotypes, each composed of 2 to 19 strains obtained from different hosts, suggest the occurrence of a brucellosis outbreak epidemic with multiple source points and laboratory infection events. Moreover, 30 shared MLVA-16 genotypes were observed among 59.6% (68/114) B. melitensis isolates from Zhejiang and strains from other 21 different provinces, especially northern provinces, China. The analysis highlighted the imported nature of the strains from all over the northern provinces with a dominant part from the developed areas of animal husbandry. These data revealed a potential transmission pattern of brucellosis in this region, due to introduced infected sheep leading to a brucellosis outbreak epidemic, and eventually causing multiple laboratory infection events. It is urgent to strengthen the inspection and quarantine of the introduced animals.

Shedding of Brucella melitensis happens through milk macrophages in the murine model of infection

Although shedding of zoonotic brucellae in milk has been demonstrated in natural hosts, these data are still missing for the standard murine infection model. We therefore analysed shedding kinetics and the niche of B. melitensis in murine milk. Pregnant Balb/cByJ mice were intraperitoneally infected with 10⁵ CFU of the 16 M reference strain, a 16 M mCherry mutant or a human isolate. Milk was collected over the course of lactation, and subjected to culture and immunofluorescence assays. Bacteria were also quantified in spleen and mammary glands of maternal mice and in spleen of the litter. The shedding of the three strains did not differ significantly (p = 0.301), ranging from log₁₀ 1.5 to 4.04 CFU/ml. A total of 73% of the mice excreted B. melitensis into the milk with peak values at mid-lactation; up to 30 bacteria/cell were found in macrophages and neutrophils. While the bacterial counts in the spleen of lactating females confirmed a well-established infection, only 50% of the pups harboured brucellae in their spleen, including the spleen of an uninfected pup fed by an infected foster mother. In conclusion, the murine model of infection may contribute to a better understanding of the zoonotic transmission of brucellosis.

Investigation of the molecular characteristics of Brucella isolates from Guangxi Province, China

Background

Human brucellosis has become a severe public health problem in China’s Guangxi Province, and there has been higher prevalence of brucellosis in this region after 2010. Both multiple locus variable-number tandem repeat analysis (MLVA) and multilocus sequence typing (MLST) assay schedules were used to genotype isolates and determine relationships among isolates.

Results

A total of 40 isolates of Brucella were obtained from humans, pigs, and dogs from 1961 to 2016. There were at least three species of Brucella detected in Guangxi Province, Brucella melitensis, Brucella suis, and Brucella canis, with 16, 17, and 7 isolates, respectively. Of which B. suis biovar 3 was the predominant species resulting in pig brucellosis in the area examined before 2000s. Moreover, B. melitensis biovar 3 was found to be mainly responsible for human brucellosis during 2012–2016. All B. melitensis isolates in this study belonged to East Mediterranean lineage. MLVA-11 genotype 116 was the dominant genotype and represented 81.2% of the isolates. MLVA cluster analysis showed there to be 44% (7/16) brucellosis cases caused by B. melitensis with a profile of outbreak epidemic from 2012 to 2016. However, nearly 83.3% (20/24) of brucellosis cases resulting from both B. suis and B. canis showed no epidemiological links or sporadic characteristics. MLVA-16 analysis confirmed extensive genotype-sharing events between B. melitensis isolates from Guangxi and other northern provinces within China. These data revealed that there are potential epidemiology links among these strains. B. suis strains of this study showed a unique genetic lineage at the global level and may have existed historically in this area. However, present B. canis isolates were closely related to previously reported isolates in Korea, where they may have originated. MLST typing showed that the population structure of Brucella strains had changed considerably in this province; ST17 and ST21, two previously predominant populations appeared to have been replaced by recently emerging ST8 group.

Conclusions

Our investigation data have inspired the hypothesis that Guangxi Province had been subject to an imported human brucellosis epidemic. Our data suggest that strains found in Northern regions of China are the principal source of infections in recent cases of human brucellosis in Guangxi Province. Comparative genomic analysis from more strains is necessary to confirm this hypothesis. This work will facilitate better understanding of the epidemiology and improve the effectiveness of control and prevention of brucellosis in this region.

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.

Comparison of PCR-RFLP and PFGE for determining the clonality of Brucella isolates from human and livestock specimens

Brucellosis is an important zoonotic disease caused by different species of genus Brucella that are pathogenic for humans and a variety of animals. Accurate detection of Brucella spp. infection is important for control of disease. The aim of this study was to comparison of molecular genotyping of Brucella strains by Pulsed-field gel electrophoresis (PFGE) and polymerase chain reaction -Restriction Fragment Length Polymorphism (PCR-RFLP) techniques. Twenty- seven Brucella spp. were isolated from human and animal samples. The isolates identified by conventional microbiological methods and confirmed using PCR for amplification of omp2a gene. Molecular typing of Brucella strains carried out by PCR-RFLP after PstI and PFGE of chromosomal DNA after XbaI enzyme digestion. The omp2a gene PCR Products with different patterns of PCR-RFLP were sequenced. The omp2a gene amplification of all human and animal Brucella isolates were positive for 1100 bp fragment. By PCR-RFLP analysis two genotypes/patterns for human isolates and four genotypes for animal isolates were obtained. In PFGE analysis totally, 7 common clones/clusters and 3 single clones were obtained. The results of this study showed the PFGE method is the more reliable and useful assay for molecular typing of Brucella strains and is more preferred to PCR-RFLP in determination of genetic similarity among human and animal Brucella isolates. The presented data showed PCR-RFLP analysis was not able to differentiate between B. melitensis biovars and vaccine strain.

Core Genome Multilocus Sequence Typing and Single Nucleotide Polymorphism Analysis in the Epidemiology of Brucella melitensis Infections

The use of whole-genome sequencing (WGS) using next-generation sequencing (NGS) technology has become a widely accepted method for microbiology laboratories in the application of molecular typing for outbreak tracing and genomic epidemiology. Several studies demonstrated the usefulness of WGS data analysis through single-nucleotide polymorphism (SNP) calling from a reference sequence analysis for Brucella melitensis, whereas gene-by-gene comparison through core-genome multilocus sequence typing (cgMLST) has not been explored so far. The current study developed an allele-based cgMLST method and compared its performance to that of the genome-wide SNP approach and the traditional multilocus variable-number tandem repeat analysis (MLVA) on a defined sample collection. The data set was comprised of 37 epidemiologically linked animal cases of brucellosis as well as 71 isolates with unknown epidemiological status, composed of human and animal samples collected in Italy. The cgMLST scheme generated in this study contained 2,704 targets of the B. melitensis 16M reference genome. We established the potential criteria necessary for inclusion of an isolate into a brucellosis outbreak cluster to be ≤6 loci in the cgMLST and ≤7 in WGS SNP analysis. Higher phylogenetic distance resolution was achieved with cgMLST and SNP analysis than with MLVA, particularly for strains belonging to the same lineage, thereby allowing diverse and unrelated genotypes to be identified with greater confidence. The application of a cgMLST scheme to the characterization of B. melitensis strains provided insights into the epidemiology of this pathogen, and it is a candidate to be a benchmark tool for outbreak investigations in human and animal brucellosis.

An Overview of Brucellosis in Cattle and Humans, and its Serological and Molecular Diagnosis in Control Strategies

Brucellosis is one of the most common contagious and communicable zoonotic diseases with high rates of morbidity and lifetime sterility. There has been a momentous increase over the recent years in intra/interspecific infection rates, due to poor management and limited resources, especially in developing countries. Abortion in the last trimester is a predominant sign, followed by reduced milk yield and high temperature in cattle, while in humans it is characterized by undulant fever, general malaise, and arthritis. While the clinical picture of brucellosis in humans and cattle is not clear and often misleading with the classical serological diagnosis, efforts have been made to overcome the limitations of current serological assays through the development of PCR-based diagnosis. Due to its complex nature, brucellosis remains a serious threat to public health and livestock in developing countries. In this review, we summarized the recent literature, significant advancements, and challenges in the treatment and vaccination against brucellosis, with a special focus on developing countries.

Genotyping of Brucella melitensis and Brucella abortus strains in Kazakhstan using MLVA-15

Currently, although the prevalence of brucellosis in Kazakhstan remains high, there are limited data available on the genetic diversity of circulating Brucella strains. Here, MLVA was employed to genotype a panel of 102 Brucella isolates collected from eight Kazakh regions and neighboring countries (Russia, Kyrgyzstan) during the period 1935-2017. MLVA-11 analysis classified 64 B. abortus strains into genotypes 72, 82, 331, 71, 341 and 69, while one genotype was novel, having no correspondence within the MLVA international database. MLVA-11 analysis of 37 B. melitensis strains showed 100% identity with genotypes 116, 114 and 11. One B. suis strain was classified into genotype 33. Phylogeography based on MLVA-15 demonstrated that all B. abortus and B. melitensis strains belonged to "Abortus C" and "East Mediterranean" lineages, respectively. B. abortus strains from Kazakhstan and Russia resulted genetically related to Portuguese, Brazilian and US isolates, suggesting ancient spread of these lineages from Europe westwards to South America and eastwards to Turkey, Russia and Asia. Most of Kazakh B. melitensis isolates were related to strains circulating in China, likely due to long-term trading partnerships between the two countries. In fine-scale MLVA-15 analysis, 17 B. abortus and 12 B. melitensis genotypes were identified; among them 12 are novel. Interestingly, epidemiological information supporting molecular data were retrieved for two clusters within the B. abortus group, thus proving that MLVA is an appropriate tool for effective traceback analyses. Our findings suggest that molecular genotyping should be applied systematically to support control plans for eradication of brucellosis in Kazakhstan.

Prevalence and risk factors of brucellosis among veterinary health care professionals

The study describes prevalence, clinical symptoms and risk factors for brucellosis in personnel engaged in veterinary health care in Karnataka, India. A total of 1050 sera samples were collected from animal handlers, veterinarians, veterinary students, para-veterinarians and persons engaged in artificial insemination of animals. The sera samples were tested for brucellosis by Rose Bengal plate test (RBPT), serum agglutination test (SAT), IgG and IgM indirect ELISA and PCR. Age, sex, clinical symptoms and risk factors were recorded in structured questionnaire. Of the 1050 samples tested, 6.76, 6.38, 3.90, 2.67 and 2.0% were positive by IgG ELISA, RBPT, SAT, IgM ELISA and PCR, respectively and overall prevalence recorded was 7.04%. The prominent clinical symptoms observed were intermittent fever (71.62%) followed by joint pain and body aches. A high degree of suspicion, awareness and multimodal diagnostic approach is suggested for early diagnosis, treatment and disease follow up.