MLVA fingerprinting of Brucella melitensis circulating among livestock and cases of sporadic human illness in Egypt

Animal Brucellosis in Egypt: Review on Evolution, Epidemiological Situation, Prevalent Brucella Strains, Genetic Diversity, and Assessment of Implemented National Control Measures

Brucellosis is a neglected zoonotic disease that has a significant economic and public health impact, especially in endemic countries. This review delves deeply into brucellosis's current epidemiological situation and potential sources of livestock infection in Egypt during the last two decades. MLVA-16 and Whole Genome Sequencing based on core-genome SNP analyses confirm the presence of different B. abortus and B. melitensis outbreak strains, both older widely disseminated Brucella strains and newly introduced ones. Despite implementing the test-and-slaughter control strategy over forty years, the disease is still endemic, and different Brucella species circulate among several animal species. The raising of mixed animal species in the same households or farms, exposure to aborted animals, and lack of public awareness about brucellosis transmission are among the main risk factors for increasing livestock brucellosis prevalence in Egypt. Young animals' voluntary vaccination, lack of a nationwide animal identification system, and uncontrolled animal movement stand beyond the ineffectively applied control strategy and may be subdued by applying mass vaccination to decrease disease prevalence dramatically and target imported camels, domestic pigs, and dogs (housed and stray) in the national control surveillance. Increasing awareness through educational campaigns is compulsory to reduce brucellosis transmission risk to livestock/humans.

In silico MLVA Analysis of Brucella melitensis from Human and Livestock in Iran

Brucellosis, a zoonotic disease caused by Brucella spp. globally, is of great significance not only to livestock but also to public health. The most significant of the twelve species is Brucella melitensis. This article is devoted to the endemic region of Iran and aims to uncover the molecular epidemiology of B. melitensis. Biotyping, AMOS-PCR, Bruce-ladder PCR, and the in silico method of MLVA were employed to test 40 B. melitensis isolates from humans, cows, sheep, goats, camels, and horses which are found in thirteen Iranian provinces throughout the years 2015 to 2022. The data from the MLVA-8 analysis showed that there were seven genotypes that could be identified, and the most commonly identified genotype was genotype 63. The data from the MLVA-10 analysis showed that there were seven genotypes, with genotype 213 being the most prevalent in Iran. The data from the MLVA-11 analysis showed that there were eight genotypes, with genotype 111 being the most prevalent in Iran. The MLVA and SNP analysis results showed that the bacteria were grouped into two main groups, known as the Eastern Mediterranean and American groups. Moreover, the outcomes from these analyses have added considerably to our understanding of the genetic/historical relationships among the isolates. Our study indicates a high prevalence of B. melitensis biovar 1 in Iran, accounting for 82.5% of the isolates. The study provides insight into such matters as the complex epidemiology of B. melitensis in Iran, suggesting different ways of transmission and sources of infection. This research points out the vital significance of the continuation of the surveillance and curation of B. melitensis in the diverse species of animals and humans. The simplicity and efficiency of MLVA-based molecular epidemiology offer information on the geographic distribution and genetic diversity of B. melitensis and, therefore, help in the devising of targeted strategies for the prevention of disease in animals.

Comprehensive epidemiological evaluation of ruminant brucellosis and associated risk factors in some Egyptian Governorates

Background and Aim

Brucellosis contributes to significant economic losses due to abortion, weak newborns, infertility, and up to 20% reductions in milk yield in carrier animals. This study aimed to estimate the prevalence of ruminant brucellosis in six Egyptian governorates. This study aimed to estimate the prevalence of ruminant brucellosis and evaluate the risk factors regarding the epidemiological status, highlighting the importance of early carrier detection for the success of control programs.

Materials and Methods

A total of 3000 ruminants were investigated. Blood and serum samples were collected for routine hemato-biochemical analysis (complete blood picture and metabolic panel). In addition, genotoxicity analysis was performed, whereas tissue samples were collected for histopathological analysis. The buffered acidified plate antigen test (BAPAT), Rose Bengal plate test (RBPT), and complement fixation test (CFT) were used for serological diagnosis of brucellosis. The obtained bacterial colonies were typed using Brucella abortus-, melitensis-, ovis-, and suis-polymerase chain reaction (AMOS-PCR), depending on the variability of the IS711 fragment among Brucella spp. Serum trace elements, oxidative stress, and acute phase proteins were compared according to body condition score (BCS) and clinical condition images within the study population.

Results

Mastitis and abortion were the key recorded symptoms (9.966%, 299/3000 and 6%, 180/3000, respectively); however, symptomless individuals were predominant (82.9%, 2487/3000). Blood lymphocytosis was prominent even in asymptomatic animals. Nutritional and food conversion conditions were defined as low, moderate, or high BCS. Brucella overall seropositivity by BAPAT, RBPT, and CFT was 6.1% (182/3000), 5.6% (168/3000), and 5.1% (154/3000) in ruminant species within the included governorates, respectively. Upon diagnosis, 154 seropositive cases developed 93 bacterial isolates and a 731-bp PCR fragment whose sequences confirmed Brucella melitensis biovar 3. Serum metabolic and biochemical profiles, acute phase proteins, trace elements, and oxidative stress concentrations were indicative of loss of functionality in the liver and kidneys, malnutrition and malabsorption syndrome, and DNA damage, particularly in the low-BCS groups (p < 0.0001). Granulomatous lesions were most prominent in the lymph nodes, spleen, uterus, and udder of the dams, while placental multifocal necrosis with thrombosis was recorded in aborted fetuses. There were 8 types of chromosomal aberrations detected in peripheral white blood cells. The highest frequency was for dicentric aberrations 0.025% (25/1000), whereas the lowest 0.009% (9/1000) was for acentric, ring, fusion, and polyploidy. The difference between species was significant for BCS; 14.2% in low-BCS cattle and camels and 8.4% in high-BCS buffaloes.

Conclusion

B. melitensis biovar 3 is prevalent in Egypt. Mixed-rearing systems are the main risk factors for interspecies transmission among ruminants. The difficulty in accurately diagnosing all infected animals, particularly carriers, is a major limitation of eradication and control programs. Different biomarkers could be indicators and/or sensors for performance and/or infectivity conditions in animal herds; however, they require further optimization. Early detection using molecular technologies, highly descriptive, quantitative, sensitive, and specific methods, as alternatives to serological diagnosis (CFT, BAPAT, and RBT), is urgently needed to enhance the efficiency of brucellosis-specific prophylaxis. Such a comprehensive procedure is the World Organization for Animal Health dependent decision.

Molecular typing methods to characterize Brucella spp. from animals: A review

Brucellosis is an infectious disease of animals that can infect humans. The disease causes significant economic losses and threatens human health. A timely and accurate disease diagnosis plays a vital role in the identification of brucellosis. In addition to traditional diagnostic methods, molecular methods allow diagnosis and typing of the causative agent of brucellosis. This review will discuss various methods, such as Bruce-ladder, Suiladder, high-resolution melt analysis, restriction fragment length polymorphism, multilocus sequence typing, multilocus variable-number tandem repeat analysis, and whole-genome sequencing single-nucleotide polymorphism, for the molecular typing of Brucella and discuss their advantages and disadvantages.

Molecular epidemiological characteristics of osteoarthritis-associated Brucella melitensis in China: evidence from whole-genome sequencing-based analysis

BACKGROUND

Brucellosis, developing complications including arthritis, spondylitis, sacroiliitis, and osteomyelitis, is one of the most common zoonotic diseases in the current world which causes economic losses to the livestock industry and is a great public health concern. Brucella melitensis are the main pathogen of brucellosis epidemics in China, most of which are located in northern China. However, there is limited knowledge about the epidemiology of osteoarthritis-associated brucellosis. This study was aimed to reveal the prevalence of osteoarthritis-associated brucellosis in Inner Mongolia and also to investigate the molecular characteristics of B. melitensis isolates.

METHODS AND RESULTS

In 2018, the osteoarthritis symptoms of brucellosis in the Brucellosis department of a hospital in Inner Mongolia were investigated. Twenty osteoarthritis-associated B. melitensis strains, isolated from the inpatients in Inner Mongolia during 2013-2017, were subjected to whole genome sequencing. The multilocus sequence type (MLST) and core genome SNP (cgSNP) analysis were conducted to detect molecular epidemiological characteristics. The incidence of brucellosis osteoarthritis symptoms in males (85/120, 70.8%) was significantly higher than that in females (35/120, 29.2%), and the age of patients was concentrated between 41 and 60 years old. In silico analyses indicated ST8 was the prevalent sequence type and the transmission of osteoarthritis-associated B. melitensis among different geographical areas. All strains carry virulence genes, including cgs, lpsA, manCoAg, pgm, pmm, virB4, wbdA and wboA.

CONCLUSION

Our study showed the close epidemiologically connection of osteoarthritis-associated B. melitensis strains in northern China. And ST8 was the prevalent sequence type which need our attention.

Epidemiological changes and molecular characteristics of Brucella strains in Ningxia, China

Objective

Human brucellosis causes serious public health concerns in Ningxia, China.

Methods

This study employed epidemiological, bacteriological, and multiple-locus variable-number tandem repeat analysis (MLVA) methods to conduct an epidemiological investigation, which is necessary for devising tailored control strategies.

Results

Between 1958 and 2022, 29,892 cases were reported, with an average annual number of cases and incidence of 467 and 7.1/100,000, respectively. The epidemic situation gradually worsened, with cases escalating from 26 cases in 2005 to 6,292 in 2022, with the incidence rate rising from 0.441 in 2005 to 86.83 in 2022. Geographically, the disease spread from a single affected county in 2004 to encompass all 22 counties in 2022. Yanchi County had the highest incidence, followed by the Hongsibao and Tongxin counties. These data suggest that Brucella infection has become a rampant regional concern in human brucellosis. Between 1958 and 2019, a total of 230 Brucella strains were identified across four studied hosts. These strains comprised four species with 12 biovars, including B. melitensis bv. 1, bv. 2, bv. 3, B. abortus bv. 1, bv. 3, bv. 4, bv. 5, bv. 6, bv. 7, B. suis bv. 1 and bv. 3, and B. canis. These data highlight the high species/biovars and host diversity of the Brucella population, posing a substantial challenge to brucellosis surveillance. There was an apparent transition from multiple species/biovars historically to the current dominance of a single species, B. melitensis, emphasizing the requirement for strengthening surveillance of B. melitensis. Genotypes 42 and 116, constituting 96.2% of the total number of genotypes, predominated in panel 1 and MLVA-11, indicating that all strains belong to the East Mediterranean lineage. MLVA cluster analysis revealed persistent transmission of dominant circulating genotypes, presenting an epidemic pattern characterized primarily by epidemiologically related cases with a few sporadic cases. Strains in this study exhibited high genetic homogeneity with strains from the Northwest, and those from Kazakhstan and Mongolia.

Conclusion

The epidemic situation of human brucellosis has gradually worsened; the rampant epidemic of the disease has become a regional concern. The present study highlights that implementing the of targeted surveillance and intervention strategies is urge.

Brucellae as resilient intracellular pathogens: epidemiology, host-pathogen interaction, recent genomics and proteomics approaches, and future perspectives

Brucellosis is considered one of the most hazardous zoonotic diseases all over the world. It causes formidable economic losses in developed and developing countries. Despite the significant attempts to get rid of Brucella pathogens in many parts of the world, the disease continues to spread widely. Recently, many attempts proved to be effective for the prevention and control of highly contagious bovine brucellosis, which could be followed by others to achieve a prosperous future without rampant Brucella pathogens. In this study, the updated view for worldwide Brucella distribution, possible predisposing factors for emerging Brucella pathogens, immune response and different types of Brucella vaccines, genomics and proteomics approaches incorporated recently in the field of brucellosis, and future perspectives for prevention and control of bovine brucellosis have been discussed comprehensively. So, the current study will be used as a guide for researchers in planning their future work, which will pave the way for a new world without these highly contagious pathogens that have been infecting and threatening the health of humans and terrestrial animals.

Original and introduced lineages co-driving the persistence of Brucella abortus circulating in West Africa

Introduction

Brucellosis, a serious public health issue affecting animals and humans, is neglected in West Africa (WA).

Methods

In the present study, bio-typing, multi-locus sequence typing (MLST), multiple-locus variable-number tandem repeat analysis (MLVA), and whole genome sequencing single-nucleotide polymorphism (WGS-SNP) analysis were used to characterize the Brucella abortus (B. abortus) strains from WA.

Results

All of the 309 strains analyzed in this study were extracted and downloaded from the international MLVA bank and were from 10 hosts (cattle, humans, ovine, buffalo, dromedaries, horse, sheep, zebu, dog, and cat) distributed in 17 countries in WA. Based on the bio-typing, three biovars, dominated by B. abortus bv.3, were observed and reported across seven decades (1958–2019). With MLST, 129 B. abortus strains from the present study were sorted into 14 STs, with ST34 as the predicted founder. These 14 STs clustered into the global MLST data into three clone complexes (C I–C III) with the majority of strains clustering in C I, while C II forms an independent branch, and C III harbors three STs shared by different continents. These data revealed that most cases were caused by strains from native lineages. According to the MLVA-11 comparison, 309 strains were divided into 22 MLVA-11 genotypes, 15 of which were unique to WA and the remaining seven had a global distribution. MLVA-16 analysis showed that there were no epidemiological links among these strains. Based on the MLVA data, B. abortus strains from WA have high genetic diversity, and predominated genotypes were descended from a native lineage. While the MLVA-16 globally highlights that the dominant native and few introduced lineages (from Brazil, the USA, South Korea, Argentina, India, Italy, Portugal, the UK, Costa Rica, and China) co-driving the B. abortus ongoing prevalence in WA. The high-resolution SNP analysis implied the existence of introduced B. abortus lineages, which may be reasonably explained by the movement and trade of dominant hosts (cattle) and/or their products.

Discussion

Our results indicated that B. abortus strains in WA consist of native and introduced strains that necessitate control such as vaccination, testing, slaughtering, and movement control by the relevant country authorities to reduce brucellosis in livestock.

First seroprevalence and molecular identification report of Brucella canis among dogs in Greater Cairo region and Damietta Governorate of Egypt

Background and Aim

Given the rise in stray and imported dogs in Egypt over the past 5 years, it is surprising that no report of Brucella canis infection in dogs or humans has been documented in Egypt's published papers. This study aimed to detect the presence of antibodies against the rough (B. canis) and smooth Brucellae among dogs in Egypt and to characterize the Brucella species circulating in dogs.

Materials and Methods

Blood samples (n = 449) were collected from owned and stray dogs in the Greater Cairo region (n = 309) and Damietta governorate (n = 140). The apparent, true, and total seroprevalence of canine brucellosis caused by B. canis infection were calculated using the 2-mercaptoethanol tube agglutination test (2-ME TAT) and rapid slide agglutination test (RSAT). We used the rose Bengal test (RBT) and the buffered acidified plate antigen test (BAPAT) to check the serum samples from dogs for the presence of antibodies against smooth Brucellae. Three polymerase chain reaction (PCR) assays - Bruce-ladder PCR, B. canis species-specific PCR (BcSS-PCR), and Abortus Melitensis Ovis Suis (AMOS)-PCR - were used to determine the Brucella species in the buffy coats of the serologically positive dogs.

Results

The overall apparent and true prevalence of B. canis infection in dogs were estimated to be 3.8% and 13.2%. The estimated true prevalence in stray dogs (15%) was higher than in owned dogs (12.5%). The BAPAT and the RBT using smooth antigens revealed that 11 (2.4%) and 9 (2%) were positive. Bruce-ladder PCR targeting eryC, ABC, and Polysaccharide deacetylase genes was able to identify B. canis in nine out of 17 buffy coat samples. AMOS-PCR identified the eight undetermined Brucella species by Bruce-ladder PCR as Brucella abortus (n = 4) and Brucella melitensis (n = 4). To exclude the presence of Brucella suis, a one-step species-specific BcSS-PCR was performed and specifically amplified all B. canis DNA (n = 9) the same as did the Bruce-ladder PCR.

Conclusion

To the best of our knowledge, this is the first report of B. canis detection in dogs in Egypt. Molecular identification of B. abortus and B. melitensis in the Egyptian canines highlights the role of stray dogs in brucellosis remerging in Brucellosis-free dairy farms. Brucella canis infection can be diagnosed specifically with the one-step BcSS-PCR. The obtained results set-an-alarm to the veterinary authorities to launch plans to control this disease in dogs.

Seroprevalence of brucellosis and molecular characterization of Brucella spp. from slaughtered cattle in Rwanda

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.

Tracking the distribution, genetic diversity and lineage of Brucella melitensis recovered from humans and animals in Egypt based on core-genome SNP analysis and in silico MLVA-16

Brucellosis is one of the most common neglected zoonotic diseases globally, with a public health significance and a high economic loss in the livestock industry caused by the bacteria of the genus Brucella. In this study, 136 Egyptian Brucella melitensis strains isolated from animals and humans between 2001 and 2020 were analysed by examining the whole-core-genome single-nucleotide polymorphism (cgSNP) in comparison to the in silico multilocus variable number of tandem repeat analysis (MLVA-16). Almost all Egyptian isolates were belonging to the West Mediterranean clade, except two isolates from buffalo and camel were belonging to the American and East Mediterranean clades, respectively. A significant correlation between the human case of brucellosis and the possible source of infection from animals was found. It seems that several outbreak strains already existing for many years have been spread over long distances and between many governorates. The cgSNP analysis, in combination with epidemiological metadata, allows a better differentiation than the MLVA-16 genotyping method and, hence, the source definition and tracking of outbreak strains. The MLVA based on the currently used 16 markers is not suitable for this task. Our results revealed 99 different cgSNP genotypes with many different outbreak strains, both older and widely distributed ones and rather newly introduced ones as well. This indicates several different incidents and sources of infections, probably by imported animals from other countries to Egypt. Comparing our panel of isolates to public databases by cgSNP analysis, the results revealed near relatives from Italy. Moreover, near relatives from the United States, France, Austria and India were found by in silico MLVA.

Tracking the Distribution of Brucella abortus in Egypt Based on Core Genome SNP Analysis and In Silico MLVA-16

Brucellosis, caused by the bacteria of the genus Brucella, is one of the most neglected common zoonotic diseases globally with a public health significance and a high economic loss among the livestock industry worldwide. Since little is known about the distribution of B. abortus in Egypt, a total of 46 B. abortus isolates recovered between 2012–2020, plus one animal isolate from 2006, were analyzed by examining the whole core genome single nucleotide polymorphism (cgSNP) in comparison to the in silico multilocus variable number of tandem repeat analysis (MLVA). Both cgSNP analysis and MLVA revealed three clusters and one isolate only was distantly related to the others. One cluster identified a rather widely distributed outbreak strain which is repeatedly occurring for at least 16 years with marginal deviations in cgSNP analysis. The other cluster of isolates represents a rather newly introduced outbreak strain. A separate cluster comprised RB51 vaccine related strains, isolated from aborted material. The comparison with MLVA data sets from public databases reveals one near relative from Argentina to the oldest outbreak strain and a related strain from Spain to a newly introduced outbreak strain in Egypt. The distantly related isolate matches with a strain from Portugal in the MLVA profile. Based on cgSNP analysis the oldest outbreak strain clusters with strains from the UK. Compared to the in silico analysis of MLVA, cgSNP analysis using WGS data provides a much higher resolution of genotypes and, when correlated to the associated epidemiological metadata, cgSNP analysis allows the differentiation of outbreaks by defining different outbreak strains. In this respect, MLVA data are error-prone and can lead to incorrect interpretations of outbreak events.

MLVA typing of Brucella melitensis and B. abortus isolates of animal and human origin from India

Brucellosis is a widely prevalent zoonotic disease of major public health significance. A collection of Brucella melitensis and Brucella abortus field isolates of animal and human origin were subjected to MLVA-15 typing followed by phylogeography studies. The MLVA-15 analysis of B. melitensis (n = 65) field isolates resulted in 48 different profiles. The panel I marker bruce45 was found to be most conserved, while the rest of the panel I markers showed low to moderate length polymorphism. Among the panel II markers, bruce04, bruce16 and bruce30 showed a high discriminatory index. The MLVA-15 typing of 13 B. abortus field isolates revealed 13 different genotypes with panel II markers showing higher discriminatory ability vis-à-vis panel I. The minimum spanning tree analysis (MST) in comparison with isolates from the international database revealed that all B. melitensis and B. abortus isolates from this study belonged to the 'Eastern Mediterranean' and the 'abortus C' lineage, respectively. The MLVA-15 typing could differentiate field isolates of B. abortus and B. melitensis originating from different regions, reaffirming the technique's potential of high resolution and suitability for local epidemiological studies. The MLVA scheme also has the advantage of comparison of local isolates with a worldwide database, allowing for phylogeographical studies.

Genotyping of Brucella strains isolated from humans and cattle of different geographical regions of Pakistan using MLVA-15

Background

Prevalence of brucellosis and MLVA genotyping in animals and humans, isolated from different regions of Pakistan was performed. Animals having history of brucellosis from the field and local farms of Bannu, Mardan, Peshawar, Swat, Lahore and Islamabad were selected for blood collection. Humans that work with them were also selected for sampling in this study. Total of 600 samples were taken from cattle and humans and subjected to Rose Bengal plate Test (RBPT) for the initial screening of positive samples. Designed primers of B.abortus for cattle and B.melitensis for humans were utilised to perform PCR. Culturing and isolation was carried to further to perform MLVA genotyping assay through the selection of two panels of primer markers.

Results

RBPT showed more number of cases of brucellosis in animals and humans compared to the PCR findings. Genotyping findings based upon MLVA‐15 set of markers demonstrated that the isolated strains of B.abortus fall in the same clade with strain A1, P8 and A2 from Pakistan and also similar with BCCN#02‐45 strain from India. On the other hand, B.melitensis isolated from different districts of Pakistan shared the same clade with BwIM‐AFG 63, BwIM‐AFG 44 strains from Afghanistan and BwIM IRN 37 strain from Iran. Selected VNTR alleles were sequenced for calibration purposes.

Conclusion

It is concluded that Brucella is prevalent in animals and humans in studied districts of Pakistan. Moreover, A1, P8, BwIM‐AFG 63, BwIM‐AFG 44 and A2 were found the common genotypes in Pakistan.

Risk factors and Molecular genotyping of Brucella melitensis strains recovered from humans and their owned cattle in Upper Egypt

Brucellosis is a zoonosis that has a devastating impact on the economy and public health, particularly in the Middle East, including Egypt. This study aimed to define risk factors associated with brucellosis in humans and in their cattle in Fayoum governorate - Upper Egypt. Also, molecular genotyping of recovered Brucella isolates from human cases and their cattle to assess the potential cross-species transmission in the study region. Data were obtained via double matched case–control studies for brucellosis in humans (106 cases and 160 controls) and in their cattle (78 cattle cases and 105 cattle controls). The results of multivariate regression analysis revealed that predictors of human brucellosis were animal-related occupations (OR 2.1, P 0.02), previous infection in other household members (OR 3.2, P 0.007), eating home-made soft cheese (OR 2.3, P 0.03), and exposure to cattle abortions (OR 6.9, P < 0.001). For cattle, predictors of brucellosis were maturity ≥2 years of age (OR 2.9, P 0.01), ≥2 animals reared by the same household (OR 3.7–6.9, P ≤ 0.001), and recent abortion (OR 15.2, P 0.01). Twelve Brucella isolates were recovered from eight human cases (7.5%, 8/106) and four cattle cases (6.2%, 4/65). All isolates were B. melitensis biovar 3. Analysis of the IS711 gene sequence revealed complete homology (100%) between isolates. Six virulence genes were utilized for virutyping: virB (100%), omp25 (100%), amiC (100%), ure (91.7%), wbkA (91.7%), and bvfA (75%). Virutyping revealed four virutypes: V1 (lack bvfA, 16.7%), V2 (harbored all genes, 66.7%), V3 (lack wbkA, 8.3%), and V4 (lack wbkA and ure, 8.3%). Repetitive extragenic palindromic PCR (REP-PCR) typing revealed two REP types. Combined REP-PCR/virulence genotyping revealed five different genotypes (G1–G5) for the detected isolates and a unique genotype for the reference strain (G6, B. melitensis bv3 Ether). Human and cattle isolates from the same household had matched genotypes. In conclusion, there were widespread risk factors among the cases studied. Health education for high-risk groups is essential for disease prevention, and combined REP-PCR/virulence genotyping is a quick tool for traceability, particularly in developing countries endemic with brucellosis as Egypt.

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The study highlighted brucellosis risk factors in human & cattle in Upper Egypt.

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The study recorded widespread risk factors among the cases.

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Cattle and human isolates in the same household had matched genotypes.

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REP-PCR/virulence genotyping could facilitate traceability in developing countries.

Whole-Genome Sequencing for Tracing the Genetic Diversity of Brucella abortus and Brucella melitensis Isolated from Livestock in Egypt

Brucellosis is a highly contagious zoonosis that occurs worldwide. Whole-genome sequencing (WGS) has become a widely accepted molecular typing method for outbreak tracing and genomic epidemiology of brucellosis. Twenty-nine Brucella spp. (eight B. abortus biovar 1 and 21 B. melitensis biovar 3) were isolated from lymph nodes, milk, and fetal abomasal contents of infected cattle, buffaloes, sheep, and goats originating 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. Illumina MiSeq^® was used to sequence the 29 Brucella isolates. Using MLST typing, ST11 and ST1 were identified among B. melitensis and B. abortus, respectively. Brucella abortus and B. melitensis isolates were divided into two main clusters (clusters 1 and 2) containing two and nine distinct genotypes by core-genome SNP analysis, respectively. The genotypes were irregularly distributed over time and space in the study area. Both Egyptian B. abortus and B. melitensis isolates proved to be genomically unique upon comparison with publicly available sequencing from strains of neighboring Mediterranean, African, and Asian countries. The antimicrobial resistance mechanism caused by mutations in rpoB, gyrA, and gyrB genes associated with rifampicin and ciprofloxacin resistance were identified. To the best of our knowledge, this is the first study investigating the epidemiology of Brucella isolates from livestock belonging to different localities in Egypt based on whole genome analysis.

Bovine brucellosis - a comprehensive review

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

Trans-species transmission of Brucellae among ruminants hampering brucellosis control efforts in Egypt

AIMS

This study aimed to identify the genotypic fingerprinting of Brucella melitensis biovar 3 isolates from ruminants in Kafr El-Sheikh, Egypt, to compare with other peers globally and to highlight the epidemiology and potential causes of brucellosis control failure.

METHODS AND RESULTS

A multilocus variable-number tandem-repeat analysis (MLVA 16) was carried out on 41 B. melitensis bv3 isolates, 31 from the preferential hosts (28 sheep and three goats) and 10 from atypical hosts (nine cattle and one buffalo), identified by bacteriological and molecular techniques. MLVA-16 analysis revealed 19 genotypes with nine as singletons. The most prevalent genotypes were M3_K.E (3,5,3,13,1,1,3,3,7,43,8,7,6,7,5,3), M13_K.E (3,5,3,13,1,1,3,3,7,43,8,5,8,7,7,3) and M5_K.E (3,5,3,13,1,1,3,3,7,43,8,4,8,7,11,3) circulating between different animal species. The B. melitensis isolation from aborted cows in farms that had never reared small ruminants indicates the likelihood of cow to cow B. melitensis transmission. Different genotypes of B. melitensis could be isolated from the same animal. The local geographic distribution of genotypes showed a very close genetic relatedness with genotypes reported outside the study area. Worldwide, our genotypes were mostly related to the Western Mediterranean lineage and less likely to the America's clonal lineage.

CONCLUSION

There is a high genetic similarity of B. melitensis bv3 genotypes among different ruminant species, and the same animal could be infected with different genotypes. There is a high probability of spreading of B. melitensis among atypical hosts in the absence of the original hosts. The genetic relatedness of B. melitensis bv3 genotypes in the study area with other different geographic areas highlighted the national and international ruminants movement role as a potential factor for maintaining B. melitensis infection.

SIGNIFICANCE AND IMPACT OF THE STUDY

Further investigations are required to understand the impact of the presence of more than one genotype of B. melitensis in the same animal on the efficacy of brucellosis control strategies.

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.

Genetic and Biochemical Diversity of Clinical Acinetobacter baumannii and Pseudomonas aeruginosa Isolates in a Public Hospital in Brazil

Life-threatening bacterial infections are a major concern in health care services worldwide. This retrospective study aimed to demonstrate genetic and biochemical diversity in isolates of Acinetobacter baumannii and Pseudomonas aeruginosa from a public hospital in Brazil. A total of 63 isolates collected from different sites of infection and hospital sectors were characterized, and their susceptibility profile to antibiotics was assessed for 18 drugs belonging to 8 antimicrobial categories using the automated BACTEC system. Genetic diversity was assessed using the multiple locus variable number tandem repeat analysis. Among the isolates of A. baumannii, 83% were classified as extensively drug resistant (XDR), and 17 genotypic profiles were identified. About 67% of P. aeruginosa isolates were susceptible to antimicrobials and were distributed into 37 genotypic profiles, revealing genetic heterogeneity. This study has demonstrated the multicolonization of investigated pathogens and the high frequency (95.8%) of multidrug-resistant and XDR, as well as high genetic diversity, among the isolates supporting the continuous need to monitor these species in the hospital environment.

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.

MLVA-16 Genotyping of Brucella abortus and Brucella melitensis Isolates from Different Animal Species in Egypt: Geographical Relatedness and the Mediterranean Lineage

Brucellosis is a common zoonotic disease in Egypt. However, there are limited data available on the genetic diversity of brucellae circulating in Egypt and other Mediterranean areas. One hundred and nine Brucella (B.) strains were isolated from different animal species in thirteen Egyptian governorates. Multi-locus variable number tandem repeats (VNTRs) analysis (MLVA-16) was employed to determine the geographical relatedness and the genetic diversity of a panel of selected Egyptian strains (n = 69), with strains originating from Italy (n = 49), Portugal (n = 52), Greece (n = 63), and Tunisia (n = 4). Egyptian B. melitensis strains clustered into two main clusters containing 21 genotypes. Egyptian B. abortus strains clustered into three main clusters containing nine genotypes. The genotypes were irregularly distributed over time and space in the study area. Egyptian strains of B. melitensis showed MLVA-16 patterns closer to that of Italian strains. Egyptian B. abortus strains isolated from cattle share the same genotype with strains from Portugal and similar to strains from Italy with low genetic diversity. Strains with similar MLVA patterns isolated from different governorates highlight the movement of the pathogen among governorates. Hence, it may also reflect the long endemicity of brucellosis in Egypt with earlier dispersal of types and great local genetic diversity. Open markets may contribute to cross-species transmission and dissemination of the new types nationwide. The presence of West Mediterranean lineages of B. melitensis and relatedness of B. abortus strains from the studied countries is a result of the socio-historical connections among the Mediterranean countries. Transnational eradication of brucellosis in the Mediterranean basin is highly demanded.