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The Veterinary Quarterly Jan 2021Brucellosis is a zoonotic disease of great animal welfare and economic implications worldwide known since ancient times. The emergence of brucellosis in new areas as... (Review)
Review
Brucellosis is a zoonotic disease of great animal welfare and economic implications worldwide known since ancient times. The emergence of brucellosis in new areas as well as transmission of brucellosis from wild and domestic animals is of great significance in terms of new epidemiological dimensions. Brucellosis poses a major public health threat by the consumption of non-pasteurized milk and milk products produced by unhygienic dairy farms in endemic areas. Regular and meticulous surveillance is essentially required to determine the true picture of brucellosis especially in areas with continuous high prevalence. Additionally, international migration of humans, animals and trade of animal products has created a challenge for disease spread and diagnosis in non-endemic areas. Isolation and identification remain the gold standard test, which requires expertise. The advancement in diagnostic strategies coupled with screening of newly introduced animals is warranted to control the disease. Of note, the diagnostic value of miRNAs for appropriate detection of infection has been shown. The most widely used vaccine strains to protect against infection and related abortions in cattle are strain 19 and RB51. Moreover, it is very important to note that no vaccine, which is highly protective, safe and effective is available either for bovines or human beings. Research results encourage the use of bacteriophage lysates in treatment of bovine brucellosis. One Health approach can aid in control of this disease, both in animals and man.
Topics: Animals; Bacterial Vaccines; Brucella; Brucellosis, Bovine; Cattle; Humans; MicroRNAs; Zoonoses
PubMed: 33353489
DOI: 10.1080/01652176.2020.1868616 -
Microbes and Infection 2019
Topics: Brucella abortus; Brucellosis; Computers, Molecular; DNA, Bacterial; DNA-Binding Proteins; Synthetic Biology
PubMed: 30590174
DOI: 10.1016/j.micinf.2018.11.002 -
Trends in Microbiology Dec 2015Brucellae are facultative intracellular pathogens. The recent development of methods and genetically engineered strains allowed the description of cell-cycle progression... (Review)
Review
Brucellae are facultative intracellular pathogens. The recent development of methods and genetically engineered strains allowed the description of cell-cycle progression of Brucella abortus, including unipolar growth and the ordered initiation of chromosomal replication. B. abortus cell-cycle progression is coordinated with intracellular trafficking in the endosomal compartments. Bacteria are first blocked at the G1 stage, growth and chromosome replication being resumed shortly before reaching the intracellular proliferation compartment. The control mechanisms of cell cycle are similar to those reported for the bacterium Caulobacter crescentus, and they are crucial for survival in the host cell. The development of single-cell analyses could also be applied to other bacterial pathogens to investigate their cell-cycle progression during infection.
Topics: Brucella abortus; Brucellosis; Caulobacter crescentus; Cell Cycle; Cell Line; Cell Proliferation; Chromosomes, Bacterial; DNA Replication; DNA, Bacterial; Endosomes; G1 Phase Cell Cycle Checkpoints; Host-Pathogen Interactions; Humans; Metabolic Networks and Pathways; Protein Transport
PubMed: 26497941
DOI: 10.1016/j.tim.2015.09.007 -
Veterinary Research Jul 2015Brucella abortus vaccines play a central role in bovine brucellosis control/eradication programs and have been successfully used worldwide for decades. Strain 19 and... (Review)
Review
Brucella abortus vaccines play a central role in bovine brucellosis control/eradication programs and have been successfully used worldwide for decades. Strain 19 and RB51 are the approved B. abortus vaccines strains most commonly used to protect cattle against infection and abortion. However, due to some drawbacks shown by these vaccines much effort has been undertaken for the development of new vaccines, safer and more effective, that could also be used in other susceptible species of animals. In this paper, we present a review of the main aspects of the vaccines that have been used in the brucellosis control over the years and the current research advances in the development of new B. abortus vaccines.
Topics: Abortion, Veterinary; Animals; Brucella Vaccine; Brucella abortus; Brucellosis, Bovine; Cattle; Female; Pregnancy
PubMed: 26155935
DOI: 10.1186/s13567-015-0199-7 -
Molecular Medicine Reports Feb 2020The present study aimed to explore the differences in protein and gene expression of Brucella abortus cultured under biofilm and planktonic conditions. The proteins... (Comparative Study)
Comparative Study
The present study aimed to explore the differences in protein and gene expression of Brucella abortus cultured under biofilm and planktonic conditions. The proteins unique to biofilms and planktonic B. abortus were separated by two‑dimensional (2‑D) electrophoresis and then identified by matrix‑assisted laser desorption/ionization‑tandem time of flight‑mass spectrometry (MALDI‑TOF/TOF‑MS). High‑throughput sequencing and bioinformatic analyses were performed to identify differentially expressed genes between B. abortus cultured under biofilm and planktonic conditions. The proteins and genes identified by proteomic and genomic analyses were further evaluated via western blot and reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) analyses. 2‑D electrophoresis identified 20 differentially expressed protein spots between biofilms and planktonic cells, which corresponded to 18 individual proteins (12 downregulated and 6 upregulated) after MALDI‑TOF/TOF‑MS analysis, including elongation factor Tu and enolase. RT‑qPCR analysis revealed that all of the 18 genes were downregulated in biofilms compared with planktonic cells. Western blot analysis identified 9 downregulated and 3 upregulated proteins. High‑throughput sequencing and bioinformatic analyses identified 14 function and pathway‑associated genes (e.g., BAbS19_I14970). RT‑qPCR analysis of the 14 genes showed that they were upregulated in biofilm compared with in planktonic state. In conclusion, these differentially expressed genes may play important roles in bacterial defense, colonization, invasion, and virulence.
Topics: Bacterial Proteins; Biofilms; Brucella abortus; Gene Expression Regulation, Bacterial; Plankton; Proteomics; RNA, Messenger; Reproducibility of Results; Signal Transduction
PubMed: 31974592
DOI: 10.3892/mmr.2019.10888 -
BMC Veterinary Research Feb 2022Azerbaijan currently ranks thirteenth in global incidence of human brucellosis, with an estimated annual incidence through 2000 at over 50 cases per million. Brucella...
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% CO. Eight additional milk samples showed growth in the absence of CO. 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.
Topics: Animals; Azerbaijan; Brucella abortus; Brucella melitensis; Brucellosis; Cattle; Female; Humans; Milk; Multilocus Sequence Typing; Pregnancy
PubMed: 35168621
DOI: 10.1186/s12917-022-03155-1 -
BMC Microbiology Feb 2017Brucellosis is a common and chronic disease of cattle and other bovids that often causes reproductive disorders. Natural infection in cattle is caused by Brucella...
BACKGROUND
Brucellosis is a common and chronic disease of cattle and other bovids that often causes reproductive disorders. Natural infection in cattle is caused by Brucella abortus and transmission typically occurs during abortions, calving, or nursing. Brucellosis is also a major zoonotic disease due to contamination of dairy products or contact with the tissues of infected animals. Brucellosis has been eradicated from most of the developed world in the last 40 years but persists in many regions-the disease remains prevalent in portions of Africa, the Middle East, Asia, and Central and South America, as well as in the Mediterranean basin. In Italy, B. abortus has persisted in southern regions in both cattle and water buffalo. Previous attempts at analyzing the phylogenetics of B. abortus in Italy have been challenging due to limited genetic variability and unresolved global population genetic structure of this pathogen.
RESULTS
We conducted genome-wide phylogenetic analyses on 11 representative strains of B. abortus from Italy, and compared these sequences to a worldwide collection of publically available genomes. Italian isolates belong to three clades that are basal to the main and global B. abortus lineage. Using six SNP-based assays designed to identify substructure within the Italian clades, we surveyed a collection of 261 isolates and found that one clade predominates throughout endemic districts in the country, while the other two clades are more geographically restricted to portions of southern Italy.
CONCLUSIONS
Although related strains exist worldwide, B. abortus isolates from Italy are substantially different than those found in much of the rest of Europe and North America, and are more closely related to strains from the Middle East and Asia. Our assays targeting genetic substructure within Italy allowed us to identify the major lineages quickly and inexpensively, without having to generate whole genome sequences for a large isolate collection. These findings highlight the importance of genetic studies to assess the status and the history of pathogens.
Topics: Africa; Animals; Asia; Brucella abortus; Brucellosis; Buffaloes; Cattle; Cattle Diseases; Cluster Analysis; DNA, Bacterial; Europe; Genetic Variation; Genotype; Geographic Mapping; Italy; Molecular Typing; North America; Phylogeny; Zoonoses
PubMed: 28152976
DOI: 10.1186/s12866-017-0939-0 -
PLoS Neglected Tropical Diseases Apr 2020Brucellosis, caused by Brucella abortus, is a major disease of cattle and humans worldwide distributed. Eradication and control of the disease has been difficult in...
Brucellosis, caused by Brucella abortus, is a major disease of cattle and humans worldwide distributed. Eradication and control of the disease has been difficult in Central and South America, Central Asia, the Mediterranean and the Middle East. Epidemiological strategies combined with phylogenetic methods provide the high-resolution power needed to study relationships between surveillance data and pathogen population dynamics, using genetic diversity and spatiotemporal distributions. This information is crucial for prevention and control of disease spreading at a local and worldwide level. In Costa Rica (CR), the disease was first reported at the beginning of the 20th century and has not been controlled despite many efforts. We characterized 188 B. abortus isolates from CR recovered from cattle, humans and water buffalo, from 2003 to 2018, and whole genome sequencing (WGS) was performed in 95 of them. They were also assessed based on geographic origin, date of introduction, and phylogenetic associations in a worldwide and national context. Our results show circulation of five B. abortus lineages (I to V) in CR, phylogenetically related to isolates from the United States, United Kingdom, and South America. Lineage I was dominant and probably introduced at the end of the 19th century. Lineage II, represented by a single isolate from a water buffalo, clustered with a Colombian sample, and was likely introduced after 1845. Lineages III and IV were likely introduced during the early 2000s. Fourteen isolates from humans were found within the same lineage (lineage I) regardless of their geographic origin within the country. The main CR lineages, introduced more than 100 years ago, are widely spread throughout the country, in contrast to new introductions that seemed to be more geographically restricted. Following the brucellosis prevalence and the farming practices of several middle- and low-income countries, similar scenarios could be found in other regions worldwide.
Topics: Animals; Brucella abortus; Brucellosis; Brucellosis, Bovine; Buffaloes; Cattle; Costa Rica; Genotype; Humans; Molecular Epidemiology; Phylogeny; Population Dynamics; Prevalence; Whole Genome Sequencing
PubMed: 32287327
DOI: 10.1371/journal.pntd.0008235 -
BMC Infectious Diseases Jun 2018Brucella abortus is a highly pathogenic zoonotic agent, tempting for the development of a rapid diagnostic method to enable adequate treatment and prevent further...
BACKGROUND
Brucella abortus is a highly pathogenic zoonotic agent, tempting for the development of a rapid diagnostic method to enable adequate treatment and prevent further spread. Enrichment of the bacteria is often used as a first step in diagnostics to increase the bacterial number above the detection limit of the real-time PCR. The enrichment of Brucella spp. takes at least 3 days, which might be avoidable if sensitive PCR methods can be used. Since many matrices contain PCR inhibitors, the limit of detection (LOD) must be determined for each separate matrix. Another aim of this study was the determination of survival of Brucella abortus in the analyzed matrices.
METHODS
The LOD for the detection of B. abortus in 14 matrices, relevant for human medicine, veterinary medicine and food and feed safety, was determined to evaluate the need of a pre-enrichment step prior to real-time PCR. The survival of B. abortus in the spiked matrices was tested by plate count in a 7-day interval for 132 days.
RESULTS
The limit of detection for B. abortus in most matrices was in the range of 10-10 CFU/g for cultivation and 10-10 CFU/g for direct real-time PCR. The survival time of B. abortus was less than 21 days in apple purée and stomach content and 28 days in water while B. abortus remained viable at day 132 in milk, blood, spinach and minced meat.
CONCLUSIONS
A direct PCR analysis without enrichment of bacteria saves at least 3 days. However, the limit of detection between direct PCR and plate count differs in a 10 fold range. We conclude that this lower sensitivity is acceptable in most cases especially if quick analysis are required.
Topics: Animals; Brucella abortus; Brucellosis; DNA, Bacterial; Flour; Humans; Limit of Detection; Meat; Milk; Real-Time Polymerase Chain Reaction
PubMed: 29871600
DOI: 10.1186/s12879-018-3134-5 -
PloS One 2022Bovine brucellosis is endemic in Rwanda, although, there is a paucity of documented evidence about the disease in slaughtered cattle. A cross-sectional study was...
Bovine brucellosis is endemic in Rwanda, although, there is a paucity of documented evidence about the disease in slaughtered cattle. A cross-sectional study was conducted in slaughtered cattle (n = 300) to determine the seroprevalence of anti-Brucella antibodies using the Rose Bengal Test (RBT), and indirect enzyme-linked immunosorbent assay (i-ELISA). Corresponding tissues were cultured onto a modified Centro de Investigación y Tecnología Agroalimentaria (CITA) selective medium and analysed for Brucella spp. using the 16S-23S ribosomal interspacer region (ITS), AMOS, and Bruce-ladder PCR assays. The seroprevalence was 20.7% (62/300) with RBT, 2.9% (8/300) with i-ELISA, and 2.9% (8/300) using both tests in series. Brucella-specific 16S-23S ribosomal DNA interspace region (ITS) PCR detected Brucella DNA in 5.6% (17/300; Brucella culture prevalence). AMOS-PCR assay identified mixed B. abortus and B. melitensis (n = 3), B. abortus (n = 3) and B. melitensis (n = 5) while Bruce-ladder PCR also identified B. abortus (n = 5) and B. melitensis (n = 6). The gold standard culture method combined with PCR confirmation identified 5.6% Brucella cultures and this culture prevalence is higher than the more sensitive seroprevalence of 2.9%. This emphasizes the need to validate the serological tests in Rwanda. The mixed infection caused by B. abortus and B. melitensis in slaughtered cattle indicates cross-infection and poses a risk of exposure potential to abattoir workers. It is essential to urgently strengthen a coordinated national bovine brucellosis vaccination and initiate a test-and-slaughter program that is not presently applicable in Rwanda.
Topics: Cattle; Animals; Brucella; Seroepidemiologic Studies; Rwanda; Brucellosis, Bovine; Cross-Sectional Studies; Brucellosis; Rose Bengal
PubMed: 36413520
DOI: 10.1371/journal.pone.0261595