Brucella Infection Research Articles

New Brucella variant isolated from Croatian cattle

BackgroundA novel Brucella strain closely related to Brucella (B.) melitensis biovar (bv) 3 was found in Croatian cattle during testing within a brucellosis eradication programme.Case presentationStandardised serological, brucellin skin test, bacteriological and molecular diagnostic screening for Brucella infection led to positive detection in one dairy cattle herd. Three isolates from that herd were identified to species level using the Bruce ladder method. Initially, two strains were typed as B. melitensis and one as B. abortus, but multiplex PCR based on IS711 and the Suis ladder showed that all of them to belong to B. melitensis, and the combination of whole-genome and multi-locus sequencing as well as Multi-Locus Variable numbers of tandem repeats Analysis (MLVA) highlighted a strong proximity within the phylogenetic branch of B. melitensis strains previously isolated from Croatia, Albania, Kosovo and Bosnia and Herzegovina. Two isolates were determined to be B. melitensis bv. 3, while the third showed a unique phylogenetic profile, growth profile on dyes and bacteriophage typing results. This isolate contained the 609-bp omp31 sequence, but not the 723-bp omp31 sequence present in the two isolates of B. melitensis bv. 3.ConclusionsIdentification of a novel Brucella variant in this geographic region is predictable given the historic endemicity of brucellosis. The emergence of a new variant may reflect a combination of high prevalence among domestic ruminants and humans as well as weak eradication strategies. The zoonotic potential, reservoirs and transmission pathways of this and other Brucella variants should be explored.

Interferon-Inducible Transmembrane Protein 3-Containing Exosome as a New Carrier for the Cell-to-Cell Transmission of Anti-Brucella Activity.

Exosomes are small extracellular vesicles that are released from cells and that function in intercellular communication. Recently, interferon-inducible transmembrane protein 3 (IFITM3) has been identified as a highly effective anti-intracellular pathogen protein that can inhibit the invasion of a wide range of pathogenic microorganisms. However, whether Brucella infection induces secretion of exosomes and whether these exosomes contain IFITM3 protein remain unknown. Here, we focused on the immune function of extracellular IFITM3 protein in the process of Brucella infection. This study is the first to show that Brucella melitensis strain M5 (Brucella M5) can stimulate macrophages to secrete large amounts of exosomes. Most importantly, we identified exosomes from Brucella M5-infected cells that were rich in molecules of IFITM3, and these exosomes could transmit the IFITM3 from one cell to another, thereby effectively inhibiting the intracellular survival of Brucella. Moreover, immunization with exosomes carrying IFITM3 decreased mouse spleen tissue damage and spleen colony forming unit (CFU), leading to the establishment of an anti-Brucella state in mice. In conclusion, our findings provide new insights into the anti-Brucella mechanism of IFITM3-containg exosomes, thus providing a theoretical foundation for systematic elaboration of the mechanisms of Brucella infection and host immunity. The results provide new ideas for the development of candidate vaccines for Brucella.

Characterization of innate immune response to Brucella melitensis infection in goats with permissive or restrictive phenotype for Brucella intramacrophagic growth

Caprine brucellosis is a chronic, world-wide distributed disease which causes reproductive failure in goats and Brucella melitensis, its causative agent, bears a great zoonotic potential. There is evidence suggesting that some cattle and pigs have an innate ability to resist Brucella infection, but this has not yet been investigated in goats. In this study, we compared caprine macrophages that exhibit extreme restriction and permissiveness to B. melitensis’ intracellular growth in vitro. Monocyte derived macrophages (MDMs) from 110 female goats were cultured and challenged in vitro with B. melitensis 16 M. After initial screening, 18 donor goats were selected based on their macrophages ability to restrict or allow bacterial intracellular growth and some elements of humoral and cellular immunity were studied in depth. MDMs that were able to restrict the pathogen’s intracellular growth showed enhanced bacterial internalization, although there were no differences between groups in the production of reactive oxygen and nitrogen intermediates following 48 h treatment with heat-killed B. melitensis. Moreover, there were no differences between groups in the level of antibodies reacting with keyhole limpet hemocyanin (natural antibodies, NAbs) or with Brucella LPS antigens (cross-reacting antibodies, CrAbs), although a strong positive correlation between individual levels of IgM NAbs and IgM CrAbs was detected. Altogether, these results represent an initial step in understanding innate primary host response to B. melitensis, and deciphering which mechanisms may determine a successful outcome of the infection in goats.

Clinicopathological and Immunological studies on brucellosis

Our view refer to clarify the seroprevalence of brucellosis infection in dairy cows in Menoufiya Governorate and to evaluate the hematological, biochemical and immunological parameters changes in blood of infected cows compared to healthy ones. Blood samples of 100 dairy cows (3-5) years from private farm and Menoufiya abattoir were screened for Brucella infection using (BAPAT) test and groups, the first group(25) serum samples were serologically and the second group (75) negative (healthy) cows. Hematological analysis revealed normocytic anemia and Lymphopenia. Biochemical analysis of brucella positive serum infected cows when compared with negative control revealed observed elevation in (AST), (ALT), (ALP) and (GGT) activity in addition to non-significant increases in creatinine level and significant decrease in serum urea in diseased cows. Total protein, α1 globulin,β2 globulin recorded significant decrease while non sig change were observed in α2 ,β1 andγ globulin in infected group. Immunologically IL-1 β and IL-10 showed significant elevation in infected group.

Medication analysis and pharmaceutical care of a case of intracranial Brucella infection

Medication analysis and pharmaceutical care of a case of intracranial Brucella infection

Formyl peptide receptor 2 (FPR2) antagonism is a potential target for the prevention of Brucella abortus 544 infection

Here, we explore the potential role of formyl peptide receptor 2 (FPR2) during Brucella abortus infection. FPR2 manipulation affected B. abortus internalization but not its growth within macrophages. During the activation of FPR2 induced by its agonist AGP-8694, a high level of Brucella uptake was accompanied by an increase in ERK phosphorylation, while intracellular survival at 24 h postincubation was observed to be associated with slightly reduced nitrite accumulation but augmented superoxide anion production. Attenuated secretion of IL-6 and IL-10 were observed 48 h postincubation in the bone marrow-derived macrophages (BMDMs) treated with the FPR2 antagonist WRW4. An opposite pattern of bacterial uptake was observed upon treatment with the FPR2 antagonist, but no significant changes in the activation of MAPKs or the production of nitrite or superoxide anion were observed. Interestingly, AGP-8694 treatment of mice did not lead to differences in spleen or liver weight but slightly enhanced bacterial proliferation was observed in the spleen. Although the weights of the spleen or liver did not differ, WRW4 treatment led to reduced bacterial proliferation in the spleen. Furthermore, FPR2 antagonist treatment was associated with high serum levels of the proinflammatory cytokines IL-12, TNF-α, IFN-γ and MCP-1, while the production of TNF-α was inhibited in AGP-8694-treated mice. IL-6 and IL-10 levels were slightly increased in AGP-8694-treated mice at 24 h postinfection. Our findings demonstrated the contribution of FPR2 via manipulating this receptor using its reported agonist AGP-8694 and antagonist WRW4 in both in vitro and in vivo systems. Although activation of the receptor did not consistently induced Brucella infection, FPR2 inhibition may be a promising strategy to treat brucellosis in animals which encourages further investigation.

Brucella infection in migratory cattle herds in Jigawa State Nigeria: A cross sectional study

A cross sectional study on Brucella infection was carried out in Jigawa State in order to evaluate seroprevalence and transmission exposure factors among migratory cattle herds. A total of 1,810 cattle of different ages and sexes were systematically selected from 147 herds across four agricultural zones in the State and screened using Serum Agglutination Test (SAT) while closed ended questionnaire was used to evaluate exposure factors. From the results out of the 1,810 (serum samples) (3.37%) tested positive. Females showed higher seropositivity (3.6%) to the infection, compared to males (2.7%). Cattle of age 4-5 years had the highest prevalence (7%), compared to 3-4 years (4.5%), 2-3years (2%), 1-2years (0.8%), with no positive reactor among cattle of less than one year (0%). Seropositive animals according to the locations was found to be highest in Zone III (5.2%), followed by Zone IV (3.9%) and Zone I (2.4%), and least in Zone II (1.5%). A higher herd prevalence was recorded in Zone III (29%), followed by Zone IV (21%) and Zone I (17%), with lowest in Zone II (12%). The overall herd prevalence was 20.4%. There was association between herds that do not practice quarantine, raise multiple species, share communal pastures and water points with Brucella infection (P< 0.05) and they are more likely to acquire the infection as indicated by odds ratio. In conclusion the results have indicated that Brucella infection exists in the studied herds and some exposure factors were identified. It is hereby recommended that herd owners should practice quarantine of newly purchased animals, avoid herding multiple species of animals together, carryout routine testing and minimize contacts at grazing and water points.
 Keywords: Brucella, Cattle herds, Exposure factors, Jigawa State, SAT, Seroprevalence, Serum

Brucella: Reservoirs and Niches in Animals and Humans.

Brucella is an intracellular bacterium that causes abortion, reproduction failure in livestock and leads to a debilitating flu-like illness with serious chronic complications if untreated in humans. As a successful intracellular pathogen, Brucella has developed strategies to avoid recognition by the immune system of the host and promote its survival and replication. In vivo, Brucellae reside mostly within phagocytes and other cells including trophoblasts, where they establish a preferred replicative niche inside the endoplasmic reticulum. This process is central as it gives Brucella the ability to maintain replicating-surviving cycles for long periods of time, even at low bacterial numbers, in its cellular niches. In this review, we propose that Brucella takes advantage of the environment provided by the cellular niches in which it resides to generate reservoirs and disseminate to other organs. We will discuss how the favored cellular niches for Brucella infection in the host give rise to anatomical reservoirs that may lead to chronic infections or persistence in asymptomatic subjects, and which may be considered as a threat for further contamination. A special emphasis will be put on bone marrow, lymph nodes, reproductive and for the first time adipose tissues, as well as wildlife reservoirs.

A Novel Evidence of Immunological and Molecular Detection of Brucella Species in Camels

Objectives: Brucellosis is a zoonosis with severe complications for both humans and animals. In this work, we intended to examine the Brucella infection in dromedary camels in Qatar by using different analysis.
 Materials and Methods: A total of 203 samples of dromedary camels were randomly collected from the nearby farms in Qatar. Real-time PCR for the genus specific Brucella cell surface salt extractable bcsp31 kDa protein gene were performed on DNA extracted from camel samples. Rose Bengal and rivenol tests were performed to detect the Brucella species. The milk samples were collected from the camels and utilized for the milk ring test.
 Results: The outcomes of RT-PCR analysis illustrate the presence of Brucella spp. in 170 samples (83.74%) out of 203 samples. The findings of immunological assays also proved the presence of Brucella spp. such as Rose Bengal (67.14%), ELISA (71.42%), and precipitation assay (65.71) in both serum and blood samples of the dromedary camels, which were collected from the Qatar.
 Conclusions: In conclusion, it was clear that the incidence of the brucellosis in camels is significantly rising in Qatar region and there is a need to control the spread of the disease from camels to camels as well as from camels to humans.

Seroprevalence and Associated Risk Factors of Canine Leptospira and Brucella Species Infection in West Shewa Zone, Central Ethiopia.

PurposeCanine leptospirosis and brucellosis are significant zoonotic gram-negative bacterial diseases that affect humans and animal species. This study was aimed to estimate the seroprevalence and assess associated risk factors of canine Leptospira and Brucella species infections in Ambo, Bako, and Gojo Towns, West Shewa Zone, Ethiopia.MethodsA total of 385 serum samples were collected from randomly selected dogs. Antibodies against Brucella and Leptospira species infection were tested using the Enzyme-Linked immunosorbent Assay technique (ELISA). A structured questionnaire survey was administered to each dog-owning household to gather information on potential risk factors. The association between independent and outcome variables was analyzed using the Chi-square test followed by univariable, and multivariable logistic regression analyses.ResultsThe overall seroprevalence of Brucella and Leptospira species infections were found to be 15.06% (95% confidence interval (ci): 11.64–19.04%) and 4.16% (95% ci: 2.39–6.67%), respectively. Multivariable logistic regression analysis showed that the town was the significant risk factor of Brucella species infection seropositivity. Accordingly, dogs found in Gojo ((odds ratio (OR)): 17.72 CI: 1.17–117.54, p=0.036) and Bako (OR: 7.99, 95% CI: 0.96–66.37), p=0.054 towns were more at risk to be infected with Brucella species than dogs living in Ambo.ConclusionThe seroprevalence of Leptospira and Brucella species infections in dogs of the West Shewa Zone was high and moderate, respectively, suggesting the possible transmission of the disease between dogs and other animals. These infections might be an under-recognized threat to public health and animal welfare. Further research on the identification of the serovars of Leptospira and biotypes of Brucella circulating in dogs is encouraged. Finally, knowledge of the comprehensive epidemiology of these diseases is an invaluable input for veterinarians, healthcare professionals, and policy-makers to avoid or manage canine leptospirosis and brucellosis.

A quantum dot fluorescent microsphere based immunochromatographic strip for detection of brucellosis

BackgroundBrucellosis is a serious zoonosis disease that frequently causes significant economic loss in animal husbandry and threatens human health. Therefore, we established a rapid, accurate, simple and sensitive fluorescent immunochromatographic strip test (ICST) based on quantum dots (QDs) for detection the antibodies of Brucella infection animals serum.ResultsThe test strips were successfully prepared by quantum dot fluorescent microspheres (QDFM) as tracers, which were covalently coupled to an outer membrane protein of Brucella OMP22. The outer membrane protein OMP28 and monoclonal antibodies of OMP22 were separately dispensed onto a nitrocellulose membrane as test and quality control lines, respectively. The critical threshold for determining negative or positive through the ratio of the fluorescent signal of the test line and the control line (HT / HC) is 0.0492. The repeatability was excellent with an overall average CV of 8.78%. Under optimum conditions, the limit of detection was 1.05 ng/mL (1:512 dilution). With regard to the detection of brucellosis in 150 clinical samples, the total coincidence rate of ICST and Rose Bengal plate test (RBPT) was 97.3%, the coincidence rate of positive samples was 98.8%, the coincidence rate of negative samples was 95.3%, the sensitivity of RBPT is 1:32, and no cross reaction with the sera of other related diseases was observed.ConclusionIn our present study, the QDFM has promising application for on-site screening of brucellosis owing to its high detection speed, high sensitivity, high specificity and low cost.

A Review of Brucellosis: A Recent Major Outbreak in Lebanon

Brucella infection remains the world’s most common bacterial zoonosis, with over half a million new cases annually, which brought renewed attention of this neglected disease. This attention is highlighted in this review manuscript, reporting worldwide outbreaks and introducing the 5th major severely prominent worldwide outbreak since 2016 which occurred in Lebanon. In this outbreak, most recent Brucella incidence was mainly observed in the Bekaa governorate with around 70% of the cases reported during the summer and spring. Furthermore, in line with the Lebanese alimentary habits, brucellosis is commonly diagnosed in adults aged between 20 and 60 years old. This paper tailors the first comprehensive One Health approach for the control of Brucellosis in Lebanon. Herein, a broad review to shed light on the complexity of Brucellosis discussing: the etiology; taxonomy; pathogenesis; epidemiology and geographic distribution of the disease; sources and transmission in both animals and humans; clinical manifestation; chemical treatment and its risk; and finally disease prevention.

Spondylodiscitis with a psoas abscess - not a case of tuberculosis

Background: Brucellosis is a zoonotic infection, commonly presenting with osteoarticular involvement. Spinal brucellosis occurs in up to 65% of affected cases, but the occurrence of a psoas abscess is rare, and may mislead the clinician to an alternative diagnosis such as tuberculosis (TB). Case Presentation: Our patient presented with history of fever and lower backache. On evaluation, he was found to have L1-L2 spondylodiscitis with an associated large left psoas abscess. Given the endemicity of TB in India, it was the first considered differential diagnosis. The abscess fluid culture, however, grew Brucella melitensis. On carefully reviewing his history, it was found that the patient had contact with goats as a part of his occupation, explaining the source of the Brucella infection. Conclusion: Brucellosis must be kept in mind as a differential diagnosis for spondylodiscitis even in the occurrence of psoas abscess, a rarity, as seen in this case - in the background of relevant contact history and endemicity.

Сравнение разных лабораторных методов выявления бруцеллёза

The rapidity, accuracy, and detection abilities of different laboratory methods (tube agglutination test (SAT), indirect ELISA, fluorescence polarization test (FPA), and blood culture methods) to detect Brucella in the laboratory. The study included 95 patients with documented and 42 patients with suspected brucellosis and 56 healthy control subjects. For the tests, the positive rates of Brucella infection detection in the confirmed group were significantly higher than in group with suspected infection (p<0.01) and in healthy controls (p<0.01). There was no significant difference between indirect ELISA and FPA in detecting antibodies to Brucella in acute (χ2=0.335), subacute (χ2=0.660), and chronic cases (χ2=5.332). Among the detection methods, indirect ELISA showed the highest sensitivity (98.9%), specificity (100%), and Youden index (0.989). The sensitivity and specificity of FPA were 96.8 and 96.4%, respectively. In order to easily and rapidly diagnose brucellosis in clinical practice, a combination of detection methods is recommended, in which Brucella antibodies are screened by FPA and then confirmed by indirect ELISA.

Meningoencephalitis in a common minke whale Balaenoptera acutorostrata associated with Brucella pinnipedialis and gamma-herpesvirus infection.

Fatal marine Brucella infections with histologic lesions specific to the central nervous system (CNS), known as neurobrucellosis, have been described in 5 species of odontocete cetaceans in the UK: striped dolphins Stenella coeruleoalba, Atlantic white-sided dolphins Lagenorhynchus acutus, short-beaked common dolphins Delphinus delphis, long-finned pilot whale Globicephala melas and Sowerby's beaked whale Mesoplodon bidens. To date, these CNS lesions have only been associated with Brucella ceti ST26 and not with B. pinnipedialis, which is rarely isolated from cetaceans and, although commonly found in various seal species, has never been associated with any pathology. This paper describes the first report of neurobrucellosis in a common minke whale Balaenoptera acutorostrata which was associated with the isolation of Brucella pinnipedialis ST24 and co-infection with Balaenoptera acutorostrata gamma-herpesvirus 2. This is the first report of neurobrucellosis in any species of mysticete and the first report of Brucella pinnipedialis in association with any pathology in any species of marine mammal, which may be due to co-infection with a herpesvirus, as these are known to be associated with immunosuppression.

West nile virus infection: One-Year postkidney transplant

West Nile virus (WNV) infections are a mosquito-borne virus of the Flaviviridae family. The clinical feature of the virus varies between individuals from being asymptomatic in most of the cases to severe central nervous system disease manifested as meningitis, encephalitis, and paralysis. Diabetic nephropathy patient with microvascular and macrovascular complications, who received a kidney transplant a year ago on immunosuppressive therapy, presented with a three-day history of upper respiratory tract infection and fever. He lived in an endemic area of brucella infection. He underwent a thorough and full evaluation with various laboratory and radiological evaluations. The patient was started empirically on ceftriaxone and acyclovir for a presumptive diagnosis of herpes encephalitis and covering also Listeria with ampicillin. The patient did not improve with the initial management, so a T2-weighted magnetic resonance imaging of the brain executed that showed nonspecific hyper-intensity in the left frontal area suggestive of microangiopathic changes. WNV-neutralizing antibodies were positive with a high titer >1:640, whereas WNV RNA was not detected in the plasma sample. In the serum sample, WNV IgM and IgG were both positive. WNV IgM antibodies were detected with 6.55 and 5.97 antibody index and were done by a semiquantitative ELISA. Furthermore, WNV-neutralizing antibodies were positive as well as with a titer of 1:80. As there is no specific antiviral treatment available, the patient management was supportive; reduction in immunosuppressive agents and the use of IV IgG. This is the first reported case of one-year post renal transplant who developed WNV encephalitis and neuropathy with significant response to immunoglobulin after 18 days of infections.

Seroprevalence of &amp;lt;i&amp;gt;Brucella&amp;lt;/i&amp;gt; Antibodies and Risk Factors Associated with Human Brucellosis in High-Risk Occupational Groups of the Noun Division in the West Region of Cameroon

Brucellosis is an anthropozoonotic disease with an important public health impact. Although the transmission of Brucella from animals to humans can occur in different epidemiological settings of sub-Saharan African countries, little data has been published on human brucellosis. This study aimed to detect Brucella antibodies and the risk factors associated to brucellosis among high-risk occupational groups of people in the Noun Division of Cameroon. For this study, a structured questionnaire was used to assess risk factors associated with human brucellosis. Thereafter, blood samples were collected from high-risk occupational groups of people in four villages. Plasma was extracted from each sample and Brucella antibodies were detected using Rose Bengal Plate Test (RBPT) and indirect Enzyme-Linked Immunosorbent Assay (i-ELISA). Of the 273 participants enrolled, the overall seroprevalence of Brucella antibodies was 12.45% with RBPT and 10.26% with i-ELISA test. This seroprevalence was significantly (P = 0.04; X2 = 9.73) higher among livestock herdsmen (15.8%), slaughterhouse workers (9.8%), butchers (4.8%), participants having no educational level (14.3%) and those experiencing above 5 years of risky activity (15%). Raw milk consumption (OR: 4.8; P = 0.001), no formal education (OR: 6.4; P = 0.03) and assistance of animal during parturition (OR: 7.2; P < 0.0001) appeared as factors that may increase the risk of Brucella infections. The detection of Brucella antibodies indicates the risk of human brucellosis in some groups of people of the Noun division. Consuming unpasteurized milk, participating in parturition and lacking knowledge on brucellosis appeared as risk factors associated with human brucellosis in western Cameroon. It raises the need of developing and implementing control measures for human and animal brucellosis.

Molecular Detection of Brucella melitensis Associated Reproductive Failure in Native Sheep Flock: Potential Public Health Pathogen from Tropical Region of Tamil Nadu

Brucellosis remains a global burden since the last century. In India, both animal and human brucella infections drastically increase every year. Outbreaks of 40 ewe’s abortion were investigated in native sheep’s from the tropical region of Tamil Nadu. Aborted maternal and fetal tissues were initially subjected to Stamps Modified Ziehl Neelsen (S-ZN) staining method. The DNA was extracted and screened for Brucella genome by Brucella cell surface salt extractable proteins (bcsp31) gene based PCR assay. Further, PCR positive samples were subjected for AMOS PCR for B. abortus, B. ovis, B. melitensis and B. suis identification and differentiation. S-ZN staining of aborted tissues revealed pink, coccobacilli organisms giving presumptive identification of Brucella sp. Molecular detection of brucellosis by bcsp31 gene based PCR in placental tissues and fetal abomasal contents of both the animals yielded a specific amplicon of 223 bp confirming it as Brucella genus infection. Molecular detection and differentiation by AMOS PCR revealed a specific amplicon of 731 bp indicating the involvement of B. meletensis infection in the native free-ranging sheep flock. It is a potent public health pathogen, highly essential to be monitored for the strategic control of brucellosis.

Thoracic vertebrae spinal brucellosis with formation of epidural abscess

Introduction:China is the largest developing country in the world, and the probability of Brucellosis is high in some areas. The incidence of spondylitis in brucellosis is 2% Mel 53%, and the most common site is the lumbar vertebrae. However, spinal cord compression caused by thoracic vertebrae brucellosis accompanied by epidural abscess is very rare. Methodology: We report a case a 59-year-old female with Brucella antibody test and serum agglutination test (SAT) for Brucella revealed brucella infection. Thoracic vertebrae magnetic resonance imaging (MRI) and computed tomography (CT) scan suggested T6, T7 vertebral destruction and at the same time, it is accompanied by spinal cord compression caused by epidural abscess. Based on preoperative clinical symptoms and auxiliary examination, Thoracic vertebrae spinal brucellosis with formation of epidural abscess suspected. Results: The preoperative symptoms of the patient decreased significantly after surgery. The patient Follow-up for 6 months showed that the pain was relieved, the nerve function recovered obviously, and the patients could walk independently. Conclusion: The formation of epidural abscess is a serious complication of spinal brucellosis, which can lead to permanent nerve damage. We have to make an early diagnosis, and when infection cannot be relieved by conservative treatment, or when neurological dysfunction continues to progress, priority should be given to surgical treatment.

Increasing of Macrophage Migration Inhibitory Factor Expression in Human Patients Infected with Virulent Brucella in Iraq

Brucellosis is a zoonotic disease caused by Brucella infections and humans usually contract this disease from close contact with infected animals or their products, usually via the ingestion of cheese or crude milk. Macrophage migration inhibitory factor (MIF) and Pro- and anti-inflammatory cytokines play an important role in susceptibility/resistance and the immunopathogenesis of Brucella infection. These cytokines are crucial factors in the initiation and progression of protective immunity against Brucella infection but the role of MIF has not been well studied in the human response to intracellular microbes. This study was designed to investigate the effect of MIF expression on Brucella susceptibility. A total of 85 positive rose Bengal tests and 24 samples from healthy individuals were collected for this study and subjected to polymerase chain reaction assays (PCR) of the bcsp31 diagnostic gene. MIF concentrations were evaluated using Enzyme-Linked immunosorbent assay (ELISA) and the results showed that 46 (54%) of the rose Bengal test samples were positive and 39 (46%) were negative for bcsp31 (p ≤ 0.05) and used as the gold standard for all of the comparisons in this study. The ELISA results indicate that the mean concentration of MIF was significantly higher in patients with positive rose Bengal tests when compared to the control groups and that its concentration increases with increasing age in both the patient and control groups (p ≤ 0.05).