Can Hematological Inflammatory Indices Be Used to Differentiate Modic Type 1 Changes from Brucella Spondylodiscitis?

Background and Objectives: Differentiation between brucella spondylodiscitis and Modic type I changes (MC1) includes difficulties. Hematological inflammatory indices (HII) such as neutrophil to lymphocyte ratio (NLR) and aggregate index of systemic inflammation (AISI) are suggested as indicators of inflammation and infection and have diagnostic, prognostic, and predictive roles in various diseases. This study aimed to evaluate differences between brucella spondylodiscitis and MC1 in terms of HII. Materials and Methods: Thirty-five patients with brucella spondylodiscitis and thirty-seven with MC1 were enrolled in the study. Brucella spondylodiscitis and MC1 were diagnosed by microbiological, serological, and radiological diagnostic tools. HII (NLR, MLR, PLR, NLPR, SII, SIRI, AISI) were derived from baseline complete blood count. Results: The two groups were similar for age (p = 0.579) and gender (p = 0.092), leukocyte (p = 0.127), neutrophil (p = 0.366), lymphocyte (p = 0.090), and monocyte (p = 0.756) scores. The Brucella spondylodiscitis group had significantly lower pain duration (p < 0.001), higher CRP and ESR levels (p < 0.001), and lower platelet count (p = 0.047) than the MC1 group. The two groups had similarity in terms of HII: NLR (p = 0.553), MLR (p = 0.294), PLR (p = 0.772), NLPR (p = 0.115), SII (p = 0.798), SIRI (p = 0.447), and AISI (p = 0.248). Conclusions: Increased HII can be used to differentiate infectious and non-infectious conditions, but this may be invalid in brucellosis. However, pain duration, CRP and ESR levels, and platelet count may be useful to distinguish brucella spondylodiscitis from MC1.

Seroprevalence of human brucellosis in Turkey: A comprehensive meta-analysis.

AIMS: Brucellosis remains a common zoonotic disease, in developing countries, as well as in Turkey where it is endemic, underdiagnosed, and underreported. The aim of this meta-analysis was to provide a comprehensive estimate of seroprevalence with a large sample size, covering all regions of Turkey, including both grey literature and published studies. METHODS AND RESULTS: A systematic search was performed in MEDLINE (via PubMed), TürkMedline (National Health Sciences-Periodicals Database), and YÖKSIS database (Higher Education Council Information System) until May 5th, 2023. The quality of the studies was evaluated independently using Joanna Briggs Institute (JBI) critical assessment tool for prevalence studies. A random-effects model (DerSimion and Laird) was utilized to estimate the overall pooled prevalence. A sensitivity analysis was performed, excluding studies with a high risk of bias. The subgroup analyses and meta-regression were conducted to explore sources of heterogeneity. Egger test and funnel plot were used to assess publication bias. The meta-analysis included 30 studies in total published between 1999 and 2021 with 51,560 individuals. In Turkey, the pooled seroprevalence of human brucellosis was estimated to be 4.5% (95% confidence interval [CI]: 3.8%-5.3%). According to the subgroup analysis, a higher seroprevalence was found in rural areas (8.0%, 95% CI: 5.4%-10.7%), high-risk occupational groups (9.9%, 95% CI: 5.3%-14.6%), and the Central East Anatolia Region (13%, 95% CI: 3.2%-22.8%). The meta-regression analysis identified living in rural areas and certain geographic regions as significant risk factors associated with higher seroprevalence. CONCLUSIONS: This meta-analysis revealed a significant burden of human brucellosis in Turkey. The findings highlight the need for public health measures and targeted interventions to reduce the burden of this zoonotic disease, especially in rural areas, high-risk occupational groups, and the East Anatolia Region.

Investigation of hematologic findings related to brucellosis in Anatolian region.

OBJECTIVES: To investigate the prevalence of hematologic findings and the relationship between hemogram parameters and brucellosis stages in patients. METHODS: This multi-center study included patients older than 16 years of age who were followed up with a diagnosis of brucellosis. Patients' results, including white blood cell, hemoglobin, neutrophil, lymphocyte, monocyte, mean platelet volume, platelet and eosinophil counts were analyzed at the initial diagnosis. RESULTS: In this study 51.3% of the patients diagnosed with brucellosis were male. The age median was 45 years for female and 41 years for male. A total of 55.1% of the patients had acute brucellosis, 28.2% had subacute, 7.4% had chronic and 9% had relapse. The most common hematologic findings in brucellosis patients were anemia (25.9%), monocytosis (15.9%), eosinopenia (10.3%), and leukocytosis (7.1%). Pancytopenia occurred in 0.8% of patients and was more prominent in the acute phase. The acute brucellosis group had lower white blood cell, hemoglobin, neutrophil, eosinophil, and platelet counts and mean platelet volume, and higher monocyte counts compared to subacute and chronic subgroups. CONCLUSION: It was noteworthy that in addition to anemia and monocytosis, eosinopenia was third most prominent laboratory findings in the study. Pancytopenia and thrombocytopenia rates were low.

Molecular and serological diagnosis of multiple bacterial zoonoses in febrile outpatients in Garissa County, north-eastern Kenya.

Bacterial zoonoses are diseases caused by bacterial pathogens that can be naturally transmitted between humans and vertebrate animals. They are important causes of non-malarial fevers in Kenya, yet their epidemiology remains unclear. We investigated brucellosis, Q-fever and leptospirosis in the venous blood of 216 malaria-negative febrile patients recruited in two health centres (98 from Ijara and 118 from Sangailu health centres) in Garissa County in north-eastern Kenya. We determined exposure to the three zoonoses using serological (Rose Bengal test for Brucella spp., ELISA for C. burnetti and microscopic agglutination test for Leptospira spp.) and real-time PCR testing and identified risk factors for exposure. We also used non-targeted metagenomic sequencing on nine selected patients to assess the presence of other possible bacterial causes of non-malarial fevers. Considerable PCR positivity was found for Brucella (19.4%, 95% confidence intervals [CI] 14.2-25.5) and Leptospira spp. (1.7%, 95% CI 0.4-4.9), and high endpoint titres were observed against leptospiral serovar Grippotyphosa from the serological testing. Patients aged 5-17 years old had 4.02 (95% CI 1.18-13.70, p-value = 0.03) and 2.42 (95% CI 1.09-5.34, p-value = 0.03) times higher odds of infection with Brucella spp. and Coxiella burnetii than those of ages 35-80. Additionally, patients who sourced water from dams/springs, and other sources (protected wells, boreholes, bottled water, and water pans) had 2.39 (95% CI 1.22-4.68, p-value = 0.01) and 2.24 (1.15-4.35, p-value = 0.02) times higher odds of exposure to C. burnetii than those who used unprotected wells. Streptococcus and Moraxella spp. were determined using metagenomic sequencing. Brucellosis, leptospirosis, Streptococcus and Moraxella infections are potentially important causes of non-malarial fevers in Garissa. This knowledge can guide routine diagnosis, thus helping lower the disease burden and ensure better health outcomes, especially in younger populations.

Equine brucellosis in Iran: serological, bacteriological and molecular analysis.

Equine brucellosis significantly impacts the health and functionality of horses, leading to complications such as bursitis infection, septic tenosynovitis, septic arthritis, and non-specific lameness resulting from joint infections. In the present study, we used the Rose Bengal plate agglutination test (RBPT), serum agglutination test (SAT), and the 2-mercaptoethanol (2-ME) assays to find equine brucellosis. From June 2018 to September 2022, 876 blood samples were randomly taken from apparently healthy racing horses in certain parts of Iran, such as Kerman, Isfahan, Tehran, Qom, and Kurdistan. DNA extraction was carried out directly on all 63 serum samples identified as seropositive through RBPT. An additional 30 seronegative serum samples were also randomly chosen for study. Bacterial culture was also done on milk, blood, and vaginal swabs taken from seropositive horses.The bacteria that were found in the samples were then put through Bruce-ladder PCR. Our results indicated that 63 (7.1%), 21 (2.3%), and 2 (0.2%) of horses were seropositive using RBPT, SAT, and 2-ME, respectively. Also, none of the 30 DNA-extracted serum samples from seronegative horses tested positive for Brucella DNA, while 44.5% (28/63) of the DNA samples from seropositive horses yielded positive results for Brucella DNA. Out of the seropositive samples, 26 had DNA from Brucella abortus and 2 had DNA from Brucella melitensis. Also, B. melitensis biovar 1 was found in two milk samples from mares in the provinces of Kerman and Isfahan. It was identified using classical biotyping, and molecular assays. It was seen that some of healthy racing horses in some parts of Iran had antibodies against Brucella. The bacteriology and PCR methodologies provide a more comprehensive and reliable means of identifying Brucella spp. infections in horse, especially when the RBPT test came back positive. This underscores the imperative for employing molecular, bacterial, and serological methods in the diagnosis and monitoring of this zoonotic infection. Additionally, this finding suggests that Brucella is being transmitted to equine hosts as a result of its presence in ruminants. The mechanism of transmission may involve interactions between infected ruminants and susceptible equines. This discovery is significant as it underscores the potential cross-species transmission of Brucella and highlights the importance of understanding and managing the spread of the pathogen in both ruminant and equine populations.

Prevalence and relevant factors of positive RF in brucellosis patients with arthralgia.

BACKGROUND: Brucellosis is a critical zoonotic disease in the world, it is the non-specific arthralgia that make brucellosis patients easily misdiagnosed as rheumatoid arthritis (RA) in endemic regions. Elevated rheumatoid factor (RF) is an essential indicator of RA, and the RF in brucellosis patients is significantly higher than healthy people. Therefore, this study further explored the distribution of RF and the relevant factors of the RF positivity in brucellosis patients with arthralgia, in order to strengthen the recognition of physicians for brucellosis patients with RF positivity, especially in brucellosis-endemic areas, so as to avoid misdiagnosis and untimely treatment that may lead to malignant outcomes. METHODOLOGY AND PRINCIPAL FINDINGS: The medical records of all 572 brucellosis inpatients were collected in the Sixth People's Hospital of Shenyang, China from 2015 to 2016. After excluding 106 patients without arthralgia, 5 patients who unwilling to perform RF testing and 16 patients with diseases that may affect RF, 445 brucellosis inpatients with arthralgia were involved in this retrospective cross-sectional study. 143 (32.1%) patients with RF >10 IU/ml were classified into the RF positive group, with an average level of 16.5[12.2, 34.7] IU/ml, of which 45 (10.1%) patients were high-positive with RF >30 IU/ml. Multivariate logistic regression model was used to further analyze the relevant factors of the RF positivity and found that age, wrist joint pain and elevated C-reactive protein (CRP) were positively associated with RF positivity, with OR of 1.02 (P = 0.024), 8.94 (P = 0.008) and 1.79 (P = 0.019), respectively. CONCLUSION: The prevalence of positive RF in brucellosis patients with arthralgia was critical, nearly one-third of patients had RF positive. Elderly men brucellosis patients with arthralgia, wrist joint pain and elevated CRP were at high risk of positive RF. It is reminded that physicians should focus on differential diagnosis during clinical diagnosis and treatment, especially in brucellosis-endemic regions.

Hybrid recombinant Omp 22, 25, and 31 immunodominant epitopes can be used for serodiagnosis of brucellosis.

Brucellosis is a well-known infectious disease in most parts of the world, especially in developing countries, common between humans and animals. Brucellosis is diagnosed by serological tests based on lipopolysaccharides (LPSs), which are bacterial cell wall antigens, and due to the similarities between LPSs antigens of some gram-negative bacterias, false-positive responses are inevitable. Alternatively, Outer membrane proteins (Omps), as antigenic conserved membrane proteins, can be used to diagnose brucellosis instead of LPS antigens. In this study, by using bioinformatics tools, linear B-cell epitopes were selected from Omp22, Omp25, and Omp31 antigens and fused with the rigid KP linker (K = Lysine, P=Proline). Designed gene cassette was cloned into pET-28a (+) vector and expressed recombinant protein was purified using Ni-NTA chromatography column and was confirmed with Poly-Histidine-HRP antibody. Finally, recombinant protein's seroreactivity with serum samples from 37 patients and 27 healthy individuals was evaluated by western blotting and enzyme-linked immunosorbent assay (ELISA) methods. Western blotting results showed high reactivity of the recombinant protein with serum samples of Brucella infected patients. ELISA results were analyzed using the receiver operating curve (ROC). Optical density cut-off point, accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and Youden index J for recombinant protein were > 0.809, 84.37%,83.78%,88.89%,88.57%, 79.31% and 0.72 respectively. Western blotting and ELISA results showed that our recombinant protein has good sensitivity and specificity for the diagnosis of brucellosis.

Seroprevalence of brucellosis and Q fever infections amongst pastoralists and their cattle herds in Sokoto State, Nigeria.

Brucellosis and Q fever are neglected zoonoses of global health importance, with unknown true prevalence in occupationally vulnerable settings, partly due to misdiagnosis for other febrile conditions and poor access to primary health care. We examined the seroprevalence of these diseases and associated factors amongst pastoralists and their cattle in Sokoto State, a hub of cattle and pastoral populations in Nigeria. Serum samples randomly collected from 137 pastoralists and 366 cattle from 27 herds in three selected Local Government Areas (LGAs) in the state were analysed for antibodies to Brucella abortus using Rose Bengal Plate Test (RBT) and competitive Enzyme-Linked Immunosorbent Assay (cELISA) as well as antibodies to Coxiella burnetti using indirect ELISA. Consenting pastoralists' knowledge, perception and practices about the diseases were assessed using a semi-structured questionnaire. Data were analysed using descriptive statistics and bivariate analysis at p ≤ 0.05 level of significance. Brucellosis adjusted individual seroprevalence were 0.83% (95%CI: 0.04-4.59%) and 0% among pastoralists; 2.28% (95%CI: 1.16-4.43%) and 5.70% (95%CI: 3.68-8.74%) in cattle by RBT and cELISA, respectively. Adjusted herd-level seroprevalence for brucellosis were 23.20% (95%CI: 11.07-42.54%) and 42.00% (95%CI: 25.27-61.11%) by RBT and cELISA, respectively. For Q fever, higher seroprevalence of 62.57% (95%CI: 54.04-70.46%) and 2.98% (95%CI: 1.57-5.58%) were recorded amongst the pastoralists and their cattle, respectively. with adjusted herd-level seroprevalence of 40.36% (95%CI: 22.57-63.17%). The LGAs of sampling were significantly (OR: 0.2; 95%CI: 0.02-1.00) associated with Q fever infection, though marginal. The majority of the pastoralists had poor knowledge, perception and practices towards the diseases. This is the first study establishing the presence of brucellosis and Q fever at the human-animal interface in Sokoto State, Nigeria. The pastoralists' poor knowledge, perception and practices about these diseases are worrisome and are important factors for consideration in disease control.

Determining Antibody Retention in Hemolyzed, Bacterially Contaminated, and Nobuto Filter Paper-Derived Serum Utilizing Two Brucella abortus Fluorescence Polarization Assays.

We evaluated hemolyzed, bacterially contaminated, and Nobuto filter paper-derived serum, collected from 50 Rocky Mountain elk (Cervus elaphus nelson) in 2017 and 2019, divided into eight treatments to determine antibody retention. Serum was analyzed on Brucella abortus-specific fluorescence polarization assay utilizing plates and tubes. Reference titers and serostatus were compared to serum held at 22 C for 4, 8, 12, and 16 d; frozen clotted blood; blood with 2% and 10% elk rumen content (held for 8 d at 22 C); and serum eluted from Nobuto filter paper. Using Cohen's kappa test of agreement, plate assay serostatus agreement was substantial or outstanding in all treatments. Serostatus agreement was outstanding in all treatments utilizing tubes. The mean change in score (treatment minus reference) showed significant negative bias in serosuspect or seropositive animals in the frozen, 2% rumen, and 10% rumen treatments on the plate assay, and the day 16 and 10% rumen treatments on the tube assay, that could ultimately result in an animal being misclassified into a serosuspect or seronegative category. Serum eluted from Nobuto filter paper produced inconsistent results and is not recommended as an alternative to serum derived from blood. Although the potential for misclassification of animals with low titers exists, analyzing hemolyzed and bacterially contaminated serum from Brucella abortus nonendemic areas can increase sample size and the potential to detect seropositive animals.

Sero-epidemiology and associated risk factors of brucellosis among sheep and goat population in the south western Nepal: a comparative study.

BACKGROUND: Brucellosis is a zoonotic disease caused by Brucella spp. In Nepal, the presence of brucellosis in small ruminants, namely sheep and goats, has impacted farmers' livelihood and the food safety of consumers. A cross-sectional study was conducted in Rupandehi district of Nepal during January to March 2020 to investigate the seroepidemiology and associated risk factors of brucellosis in the sheep and goat population. Altogether, 19 sheep and 60 goat farms in the district were visited. Owners were interviewed to get information on animals, including their management and movement patterns. Three hundred fifty-seven samples (80 sheep and 277 goat samples) were collected proportionately based on farm sizes. Each serum sample was tested with Rose Bengal Test and ELISA to estimate the seropositivity of brucellosis. Logistic regression was carried out to calculate corresponding odds ratios of each variable associated with detection of brucellosis. RESULTS: At the farm level, 31.6% (6/19; 95% CI: 12, 54%) of sheep farms and 3.3% (2/60, 95% CI: 0.9, 11.4%) of goat farms were seropositive to brucellosis. Out of 80 sheep serum samples, 12 (15%; 95% CI: 8.79-24.41%) and out of 277 goat serum samples, three (1.1%; 95% CI: 0.37-3.14%) were seropositive to brucellosis. Age greater than 1.5 years (OR = 5.56, 95% CI: 1.39, 29.38; p = 0.02) and herd size of greater than 100 (OR = 4.74, 95% CI: 1.23, 20.32, p = 0.03) were identified as significant risk factors for seropositivity of brucellosis in the sheep population. While in the goat population, none of the variables was identified as a significant risk factor. CONCLUSION: The study provides evidence that the older sheep and the sheep from the large herds were at higher risk of brucellosis. A control program should be put in place immediately in the sheep population because they may transmit infections to other livestock as they were regularly moved for grazing and selling purposes. Also, strict biosecurity measures should be implemented among pastoralists to prevent brucellosis transmission in them. We suggest further one health-based study to reveal the transmission dynamics of brucellosis between animals and humans.

Performance characteristics and costs of serological tests for brucellosis in a pastoralist community of northern Tanzania.

The control of brucellosis across sub-Saharan Africa is hampered by the lack of standardized testing and the use of tests with poor performance. This study evaluated the performance and costs of serological assays for human brucellosis in a pastoralist community in northern Tanzania. Serum collected from 218 febrile hospital patients was used to evaluate the performance of seven index tests, selected based on international recommendation or current use. We evaluated the Rose Bengal test (RBT) using two protocols, four commercial agglutination tests and a competitive enzyme-linked immunosorbent assay (cELISA). The sensitivity, specificity, positive predictive value, negative predictive value, Youden's index, diagnostic accuracy, and per-sample cost of each index test were estimated. The diagnostic accuracy estimates ranged from 95.9 to 97.7% for the RBT, 55.0 to 72.0% for the commercial plate tests, and 89.4% for the cELISA. The per-sample cost range was $0.69-$0.79 for the RBT, $1.03-$1.14 for the commercial plate tests, and $2.51 for the cELISA. The widely used commercial plate tests performed poorly and cost more than the RBT. These findings provide evidence for the public health value of discontinuing the use of commercial agglutination tests for human brucellosis in Tanzania.

Comparative study of IS711 and bcsp31-based polymerase chain reaction (PCR) for the diagnosis of human brucellosis in whole blood and serum samples.

BACKGROUND: Clinical diagnosis of human brucellosis (HB) is often difficult due to non-specific symptoms. Immunological tests have been the most common method used in HB diagnosis, but molecular methods based on quantitative polymerase chain reaction (qPCR) have largely replaced these diagnostic methods. The aim of this study was to validate a HB diagnostic qPCR method; assessing different target Brucella genes, and the influence of biological matrices (serum vs. whole blood) on analytical parameters. MATERIAL AND METHODS: Two target genes, IS711 and bcsp31, for HB molecular diagnosis were evaluated, together with biological matrix type (whole blood and serum) using samples spiked with Brucella abortus. In addition, diagnostic parameters of this qPCR method were evaluated in paired whole blood and serum samples from patients with suspected HB. RESULTS: Both genes could be potential diagnostic targets, but IS711 showed a lower limit of detection. In spiked matrix experiments, whole blood showed a lower limit of detection than serum after probit regression (224 vs. 3681 CFU/mL) and ANOVA analysis showed a significant (p < 0.001) difference between the Cq of whole blood at all dilutions and that of serum. In 12 paired clinical samples, no serum samples and only one whole blood sample tested positive for Brucella using this qPCR detection method. CONCLUSIONS: This standardized qPCR-based Brucella detection method could improve diagnosis of HB, serving as a rapid, highly sensitive, and specific test. Whole blood is better suited to qPCR-based HB diagnosis due to the presence of higher target DNA loads in this matrix, compared to serum.

Prevalence, distribution and risk factors for brucellosis infection in goat farms in Ningxiang, China.

BACKGROUND: In south China, goats are the major source of Brucellosis for human infection. However, there are few studies on the prevalence of and risk factors for goat brucellosis in south China. In this study, we conducted a cross-sectional study to investigate the herd prevalence, spatial distribution and relevant risk factors for goat brucellosis in Ningxiang county, south China. Commercial goat farms (n = 457) were randomly selected, and their disease status was ascertained by testing serum samples of chosen individuals using the Rose Bengal Test (screening test) and the Serum Agglutination Test (confirmatory test) in series. A farm with at least two positive individuals was defined as a case farm. Standardized questionnaires were used to collect information on management and hygiene practices in farms. A logistic model with a binomial outcome was built to identify risk factors for being seropositive. RESULTS: The true herd prevalence in commercial goat farms was 4.5% (95%CI: 0.2%-12.2%) and the townships in the centre of the county had higher herd prevalence. The risk factors associated with seropositive on local goat farms include "Introduction in the past 12 months" (OR= 61, 95%CI: 16-333), "Improperly disposal of the sick or dead goats" (OR= 33, 95%CI: 5-341) and "Poor hygiene in lambing pen" (OR= 25, 95%CI: 5-192). CONCLUSIONS: These findings will aid in the development of control strategies of Brucellosis in south China and risk factors identified in this study should be taken into consideration when designing a control strategy.

Brucellosis screening and follow-up of seropositive asymptomatic subjects among household members of shepherds in China.

To measure the seroprevalence of high-exposure populations in brucellosis endemic areas and report the outcome and duration of seropositive asymptomatic subjects, we screened 595 family members of shepherds in Jilin Province, China and then followed up 15 seropositive asymptomatic subjects for 18 months. We found that the seropositive rate of 15.5%. Nearly half of seropositive asymptomatic subjects (7/15) developed into brucellosis in the short term; others were still seropositive asymptomatic or had decreased SAT titer in a longer time.

Status of human brucellosis in district Malakand, Khyber Pakhtunkhwa, Pakistan.

BACKGROUND: Brucellosis is a zoonotic disease caused by the bacteria, Brucella genus. Human is always an accidental host, infected from domesticated or wild animals. METHODS: This study was conducted from September 2017 to April 2018. A total of 304 samples were collected in eight months duration from female of high-risk population connected with domesticated animals to investigate the sero-prevalence of Brucellosis using ELISA (Igm) in District Malakand, Khyber Pakhtunkhwa, Pakistan. RESULTS: The high age wise prevalence was recorded as 32.25% in female with age group 21-30 by ELISA (P<0.05). The prevalent rate was significantly high (P<0.05) in Tehsil Batkhela (32.8%) than Dargai (22.75%). It was also recorded in the present study that the prevalence was higher from January to April. It was found 20.58%, 17.64%, 14.70%, 20.58%, 17.6%, 38.23%, 45.71% and 44.11% from September to April respectively. CONCLUSION: The present study concluded that the prevalence of brucellosis is significantly high among the age group 20-40 and from January to April 2018. Further studies will be required to show the prevalence of the Brucellosis all over the country.

Non-infectious outer membrane vesicles derived from Brucella abortus S19Δper as an alternative acellular vaccine protects mice against virulent challenge.

The prime human and animal safety issues accentuate the search of promising newer alternative vaccine candidates to resolve complications associated with the live attenuated Brucella abortus strain19 (S19) vaccine. Outer membrane vesicles (OMVs S19 Δper) extracted from Brucella abortus S19Δper (S19Δper) as an alternative subunit vaccine candidate has been explored in the present study as OMVs are endowed with immunogenic molecules, including LPS and outer membrane proteins (OMPs) and do not cause infection by virtue of being an acellular entity. The LPS defective S19Δper released a higher amount of OMVs than its parent strain S19. Under transmission electron microscopy (TEM), OMVs were seen as nano-sized outward bulge from the surface of Brucella. Dynamic light scattering analysis of OMVs revealed that OMVs S19Δper showed the less polydispersity index (PDI) than OMVs S19 pointing towards relatively more homogenous OMVs populations. Both OMVs S19Δper and OMVs S19 with or without booster dose and S19 vaccine were used for immunization of mice and subsequently challenged with 2 × 105 CFU virulent Brucella abortus strain 544 (S544) to assess protective efficacy of vaccines. The less splenic weight index and less S544 count in OMVs immunized mice in comparison to unimmunized mice after S544 challenge clearly indicated good protective efficacy of OMVs. OMVs S19 Δper induced relatively high titer of IgG than OMVs S19 but conferred nearly equal protection against brucellosis. An ELISA based determination of IgG and its isotype response, Cytometric Bead Array (CBA) based quantitation of serum cytokines and FACS based enumeration of CD4+ and CD8+ T cells revealed high titer of IgG, production of both Th1 (IgG2a) and Th2 (IgG1) related antibodies, stimulation of IL-2, TNF (Th1) and IL-4, IL-6, IL-10 (Th2) cytokines, and induced T cell response suggested that OMVs S19Δper elicited Th1 and Th2 type immune response and ensured protection against S544 challenge in murine model.

MALDI-TOF MS and genomic analysis can make the difference in the clarification of canine brucellosis outbreaks.

Brucellosis is one of the most common bacterial zoonoses worldwide affecting not only livestock and wildlife but also pets. Canine brucellosis is characterized by reproductive failure in dogs. Human Brucella canis infections are rarely reported but probably underestimated due to insufficient diagnostic surveillance. To improve diagnostics, we investigated dogs in a breeding kennel that showed clinical manifestations of brucellosis and revealed positive blood cultures. As an alternative to the time-consuming and hazardous classical identification procedures, a newly developed species-specific intact-cell matrix-assisted laser desorption/ionization-time of flight mass spectrometry analysis was applied, which allowed for rapid identification of B. canis and differentiation from closely related B. suis biovar 1. High-throughput sequencing and comparative genomics using single nucleotide polymorphism analysis clustered our isolates together with canine and human strains from various Central and South American countries in a distinct sub-lineage. Hence, molecular epidemiology clearly defined the outbreak cluster and demonstrated the endemic situation in South America. Our study illustrates that MALDI-TOF MS analysis using a validated in-house reference database facilitates rapid B. canis identification at species level. Additional whole genome sequencing provides more detailed outbreak information and leads to a deeper understanding of the epidemiology of canine brucellosis.

Seroprevalence of Brucellosis among General Population in Famenin City, Western Iran in 2016: The Famenin Brucellosis Cohort Study.

BACKGROUND: Brucellosis is endemic in Iran with a higher level of endemicity in western areas, including the Hamadan province. This study aims to define the seroprevalence of brucellosis and it,s risk factors in general the population of Famenin, Hamadan province, in western Iran. METHODS: This survey was conducted on 2367 participants in Famenin and its villages from September to November 2016. After receiving written consent from subjects, demographic information was obtained through questionnaires and 10cc blood samples were taken from the participants. Blood samples were sent to the Core facility of Hamadan University of Medical Sciences and were tested using Wright and 2ME kits (Pasteur Institute, Iran) for serological detection of brucellosis. The seroprevalence of brucellosis was reported as percentage with 95% confidence interval (CI). RESULTS: Totally, 2367 individuals with the mean age (SD) of 34.6 (20.9) (range: 2 to 95) years were enrolled. Of these, 1060 (44.8%) were men and 1610 (68.0%) lived in rural areas. The seroprevalence of brucellosis according to the Wright titer (equal to or greater than 1:80) was 6.6% (95% CI: 5.62%, 7.66%). The corresponding prevalence based on 2ME titers (equal to or greater than 1:40) in subjects with positive Wright test was 37.2% (95% CI: 29.5%, 44.84%). We saw a significant association between the incidence of brucellosis and occupation (P < 0.001) and type of contact with livestock (P = 0.009) as two important risk factors. CONCLUSION: The seroprevalence of brucellosis in Famenin population was considerable. Contact with livestock, animal husbandry, farming and history of brucellosis were risk factors for brucellosis infection.