جستجوی مقالات مرتبط با کلیدواژه "brucella melitensis" در نشریات گروه "پزشکی"

Matrix Metalloproteinases (MMPs) are inflammatory mediators involved in bacterial infection and other pathological conditions. Inflammation can damage all parts of the brain, particularly sensitive areas such as the hippocampus. Chronic stress can make the brain more susceptible to infection and inflammation. This study aimed to investigate the effects of stress on the activity of MMP2 and MMP9 in the hippocampus of male Wistar rats following the administration of Brucella Melitensis (BM) vaccine.

The non-stressed group received a Brucella Melitensis vaccine strain via intracebroventicular (i.c.v) and intraperitoneal (i.p) routes. The animals were subjected to heterogeneous sequential stress for nine days and/or received the same volume of Brucella Melitensis vaccine (BMV). The activity of MMP-2 and MMP-9 was measured by Gelatin Zymography.

The results showed that stress increased the activity of MMP9 in both the control group and the BMV, i.p., injected animals. However, stress did not affect the activity of MMP2 in either the control or the BM, i.p., inoculated conditions. Stress also increased the activity of MMP9 following i.c.v. injection of BM, without a concomitant change in the activity of MMP2 in the hippocampus.

The study suggests that vaccination in stressed conditions could activate MMPs, which are essential players in inflammatory processes, in brain of immunized animals. Since the Brucella melitensis vaccine is used for the prophylaxis of brucellosis in small ruminants, these findings have important implications for understanding the effects of stress on the immune response to vaccination and inflammation in the brain.

 Human brucellosis is present on all inhabited continents with high prevalence in many areas of the world, including Kuwait and the Middle East. To implement proper control measures, the identification and characterization of Brucella species and genotypes are required through a reliable and rapid subtyping method. In previous studies, whole-genome sequencing (WGS) has shown its potential as an epidemiological typing tool. Using WGS data, this study aimed to identify the species, phage sequences, putative antibiotic resistance genes, virulence factors, and genotypes of Brucella melitensis strains isolated from patients in Kuwait and other countries.

 Five B. melitensis isolates of Kuwaiti origin and 31 other isolates of B. melitensis originating from 28 countries were analyzed using whole genome-based approaches for genotypic identification and typing. In-silico techniques were used to identify the sequences for phages, antibiotic resistance genes, virulence factors, and genotypes using multilocus sequence typing (MLST) and whole-genome single-nucleotide polymorphism (wgSNP).

 The analysis of WGS data demonstrated that all five Kuwaiti isolates belonged to the non-vaccine strains of B. melitensis. Furthermore, the data represented the presence of two phage sequences, two antibiotic resistance genes, and 51 virulence factors in Kuwaiti isolates. Eventually, the genotypes of all isolates were identified based on MLST and wgSNP analysis, and wgSNP analysis suggested the possible areas/countries of origin of Kuwaiti isolates.

 WGS data can be used to characterize Brucella isolates, and molecular techniques can be applied in-silico to rapidly identify and classify Brucella into species and genotypes and trace the possible origin of the isolates.

Brucellosis is recognized as one of the most prevalent diseases among humans and animals. This study investigated and followed up brucellosis in seropositive participants in the Famenin (Hamadan province, Iran) cohort of brucellosis and their families by culture and serology methods.

Blood samples were taken from 66 subjects, including 18 subjects in the Famenin brucellosis cohort study with antibody titers≥1:180 and 36 subjects from their families and 12 subjects in the Famenin brucellosis cohort study with antibody titers<1:80. In the serological method, standard tube agglutination test (STAT positive with≥1:80) and 2-mercaptoethanol (2-ME) test (positive with≥1:40) were performed using the patient serum. Finally, 8 cc of the blood of all subjects was used for culture in the BACTEC culture medium.

Of the 66 serum samples, 20 (30.3%) samples, including 5, 4, and 10 samples at 1:20, 1:40, and 1:80 dilution, respectively, and 1 sample at 1:160 dilution were positive by the STAT, of which 13 (65%) samples belonged to patients’ family members. Using the 2-ME test, 10 (15.2%) serum samples were positive, of which 5 (50%) cases were related to patients’ family members. Eventually, no growth of Brucella was observed in 66 flasks of the BACTEC culture medium.

Considering that a definite diagnostic method is not yet accessible, a combination of methods must be applied to diagnose the disease.

Brucellosis is a zoonotic infectious disease which any organ can be involved. Soft tissue lesions are rare manifestations of brucellosis. Brucella breast abscess in animal is not uncommon; involvement of the breast in human brucella is extremely rare. Breast abscess involvement was reported to 0.7% of the patient with brucellosis. We report the microbiological findings of breast abscess due to brucella. A 38-year-old woman living in the rural area of Kerman, Iran, presented with an abscess in the right breast. The sampling of the abscess aspiration and preparation of smears showed inflammatory fluid. Culture and PCR performed from the sample identified the presence of Brucella melitensis. The lesion had diminished in size after 8 weeks of treatment with combined doxycycline and rifampin. The possibility of breast abscess being caused by Brucella should be considered in countries, especially in endemic regions. Besides, isolated Brucella spp from microbiological cultures is important for a definitive diagnosis.

Brucellosis is an endemic disease with a high prevalence in Iran whose highest frequency is in the western region of the country. Genetic diversity investigation is an important method to determine the epidemiological relationship of Brucella isolates in different geographical areas. Therefore, the present study aimed to investigate the genetic diversity of human Brucella melitensis (B. melitensis) strains using the Multiple Locus Variable-Number Tandem Repeat Analysis (MLVA) Typing method in the west of the country.

In this study, 20 strains of isolated B. melitensis were collected from the human serum samples of suspected Brucellosis in the west of the country and were analyzed by MLVA-16 method.

The results showed that 3 genotype numbers 42, 43 and 47 were identified using MLVA-8 method and using MLVA-11 method genotypes 125, 138 and 111 were recognized. Also, 16 different genotypes were detected from the analysis of the isolates by MLVA-16 method which shows a high degree of polymorphism among the isolates due to the high genetic diversity of the isolates in Panel 2B loci.

The results showed the high genetic diversity of B. melitensis isolates in the west of the country and their genetic relationship with the known strains in the neighboring countries of the Eastern Mediterranean area, as well as the importance of the MLVA method in identifying the source of infection.

Brucella prosthetic joint infection is a rare condition. We report a case of bilateral prosthetic knee joint infection caused by Brucella melitensis, which was cured by prolonged antibiotic therapy without implant removal.

A 62-year-old woman was admitted to the Labbafinejad Hospital (Tehran, Iran), complaining of pain and swelling in her knee joints from two months ago. She was also suffering from intermittent fever and night sweats. She underwent bilateral total knee arthroplasty five years ago because of a severe degenerative joint disease. Agglutination tests (wright and 2-mercaptoethanol (2-ME)) were positive. Her knee joint fluid and blood cultures yielded B. melitensis. The polymerase chain reaction result from her knee joint fluid was positive for Brucella spp. The patient was cured after combination therapy with doxycycline, rifampin, and gentamicin. The prosthesis was retained due to the lack of loosening in radiography. Ten months after the treatment, the patient had no symptoms and could walk with no pain.

Clinicians should consider brucellosis in the differential diagnosis of prosthetic joint infection in the endemic regions. They should also be aware that if patients have no sign of implant loosening, they can achieve favorable outcomes only by using antibiotics and with no need for implant removal.

Brucellar spondylodiscitis is among the most typical forms of osteoarticular involvement that still challenges clinicians and scientists for early diagnosis.

We describe the isolation of Brucella melitensis from vertebrae in a man with spondylodiscitis who had osteoarthritis as an underlying condition. The patient showed negative results on blood samples' serological, molecular, and culture tests and had low-back pain, restricted lumbar movements, headache, poor appetite, and fatigue for the past nine months. He had a history of regular ingestion of raw cow milk and milk products for a long time. First, he was misdiagnosed as lumbar disc herniation and then underwent nonsteroidal anti-inflammatory drugs and myorelaxants treatment. The lack of fast diagnosis and appropriate treatment led to severe complications of the disease. Three months after the first magnetic resonance imaging (MRI), the findings of the second MRI without intravenous contrast showed right lateral recess and canal stenosis at L4 - L5 with narrowing the thecal sac at the disc space. Abnormal enhancement of the endplates at L4 - L5 with relating epidural space-enhancing tissue in the setting of spondylodiscitis and the associated epidural abscess was seen behind L4. Moreover, extensive high signal abnormalities in paraspinal tissues at L3, L4, L5, S1, S2, and S3 were notable. The diagnosis was approved by isolating B. melitensis biovar 1 from the culture of the vertebrate body. The Brucella isolate was characterized by Bruce-ladder PCR, AMOS PCR, and classical biotyping. The patient was treated successfully with surgical intervention and triple-antibiotic, including oral doxycycline 100 mg/12 h plus oral rifampin 300 mg/12 h for three months and intramuscular streptomycin 1 g daily for the first two weeks. The patient’s general condition and low-back pain were remarkably improved in the follow-up.

Patient histories and a series of different diagnostic procedures such as MRI, serology, molecular, and cultural tests are essential to make a rapid and accurate diagnosis of brucellar spondylodiscitis, thereby reducing the delay for brucellar spondylodiscitis treatment.

Brucella is an intracellular pathogen that causes brucellosis in humans and animals. This study aimed to assess the results of brucellosis seroprevalence among participants of the Famenin brucellosis cohort with molecular investigation technique and determine Brucella-approved species.

Following the first phase of the Famenin brucellosis cohort in 2016 which investigated the seroprevalence of brucellosis among 2367 participants in Famenin city, a total of 575 people including all seropositive and some seronegative people were examined again by wright serological tests in 2019. The PCR assay was accomplished on all cases that have wright titers ≥ 1/20 for tracing Brucella DNA using BCSP31 target gene and IS711 locus.

Out of 575 studied cases, 145 people had wright titers ≥ 1/20. The PCR reactions of these 145 blood samples were positive in 63/145 (43.44%) tested samples using primers (B4/B5) for Brucella genus detection. In the second PCR assay using specific-primers for Brucella abortus and Brucella melitensis, 18/63 (28.57%) of the samples were diagnosed as B. abortus, and 18/63 (28.57%) were diagnosed as B. melitensis.

In this study, using the selected specific genes for the diagnosis of Brucella in the genus and species levels, the PCR technique was evaluated as a promising method for the rapid and safe detection of brucellosis besides the serological test for more accurate detection of brucellosis especially in cases that are not definitive.

RNA polymerase beta subunit (rpoB) gene analysis in bacterial communities is known as a method for determining rifampin sensitivity and genetic diversity among Brucella spp. Detection of antibiotic resistance among Brucella isolates can be a critical approach to control brucellosis. However, rpoB gene analysis of Brucella melitensis for assessing rifampicin resistance has not yet been performed in Iran, which is considered an endemic area for brucellosis.

The aim of this study was to analyze the whole sequence of rpoB genes of different B. melitensis isolates from humans to identify the single-nucleotide polymorphisms (SNPs) and mutations related to rifampin resistance and to analyze the genetic diversity of these bacteria in Iran.

Between 2017 and 2019, a total of 156 blood samples along with 12 synovial fluid specimens were collected from brucellosis patients in different Iranian provinces and subjected to bacterial culture in Brucella selective media. Brucella identification was carried out using classical biotyping and molecular examinations. Polymerase chain reaction (PCR)-based amplification of the rpoB gene was performed by specific rpoB primers for whole gene sequencing. The antimicrobial susceptibility of Brucella isolates was assessed using disk diffusion susceptibility tests and minimal inhibitory concentration (MIC) methods. The presence of rifampinbinding sites and SNPs were investigated through rpoB whole gene sequencing.

Clinical B. melitensis isolates were obtained from blood (13) and synovial fluid (1) samples of patients from different regions of Iran. The results of MIC and disk diffusion susceptibility tests showed that all the isolates were sensitive to rifampin except for one isolate showing intermediate rifampin resistance based on the standards defined for slow-growing bacteria by the Clinical and Laboratory Standards Institute (CLSI). Gene analysis for identifying the mutations related to rifampin resistance and investigating genetic diversity showed that none of the B. melitensis isolates had missense mutations, confirming the susceptibility of all the studied isolates to rifampin.

The present study revealed thatrpoB gene analysis could be used for the efficient and precise identifying of the mutations related to rifampin resistance, investigating rifampin binding sites, and genotyping Brucella species. Furthermore, the identification of B. melitensis isolates with intermediate resistance to rifampicin highlighted the importance of periodically carrying out antibiotic susceptibility testing. The molecular detection of rpoB mutations in different Brucella isolates may help to prevent the spread of rifampin-resistant Brucella spp. among humans and livestock.

Brucellosis, a deteriorating zoonotic disease, is very common in most parts of Iran. Consumption of contaminated milk and dairy products is one of the most significant ways for transmission of the infections to human. Since the close rearing of cattle and sheep is practiced in Kurdistan province of Iran, the infection of cow with non-specific species is not out of mind. The present study aimed to determine the frequency of bovine milk contamination with zoonotic Brucella spp.

A total of 240 milk samples, equally from traditional and industrialized dairy farms, were collected aseptically. Conventional microbiological method was used for isolation of the bacterium, followed by the genotypic identification of the isolates. Moreover, direct molecular processing of the samples was carried out for detection of the bacterial genome. The positive samples were further genotypically assessed to identify the contamination as Brucella abortus or Brucella melitensis.

In general, 16 (6.66%) and 15 (6.25%) of the samples were contaminated with Brucella spp. in phenotypic and genotypic methods, respectively. The proportion of contamination with B. abortus and B. melitensis in phenotypic and genotypic methods were 5% and 1.66%, and 5% and 1.25%, respectively. The overall rate of contamination in traditional milk samples was more than industrialized samples.

Contamination of bovine milk with Brucella spp. is a serious threat to public health in the studied region. Continuous vaccination, application of test and slaughter policy, and presumption of pasteurized milk and dairy products are highly recommended.

The genus Brucella is a worldwide distributed intracellular bacteria, which infects animals and human. Currently, this zoonosis has been diagnosed by microbiological and serological laboratory tests. Different PCR protocols with various primer pairs and different target genes have been published for the detection of Brucella, but only a few of these primers have been used in human samples. This study aimed to evaluate and compare the sensitivity and specificity of three primer pairs in the PCR technique, each of which separately amplifies three different regions in the Brucella genome, to determine which are more comfortable for the detecting of Brucella DNA in human clinical samples. 49 clinical serum samples were isolated from suspected patients in different cities in Iran from October 2017 to July 2018. The suspected patients with brucellosis-compatible symptoms were checked. These primers amplified 3 distinctive fragments in BCSP 31 gene (B4/B5), Designed IS711 primers, and a sequence of 16SrRNA of Brucella melitensis. The results showed that the B4/B5 primer pair had the highest sensitivity and specificity for the detection of both positive and negative samples (100%). The designed IS711 primer pair detected 94% of samples, whereas the 16SrRNA primer pair was the least sensitivity, being able to detect only 30.64% of samples. The specificity of 3 techniques was 100%. The B4/B5 primers were able to detect the smallest number of bacteria 0.05 CFU/reaction whereas IS711 was able to detect 2 CFU/reaction and 16SrRNA was able to detect 2×105 CFU/reaction.

Persister cells are defined as a subpopulation of bacteria that are capable of reducing their metabolism and switching to dormancy in stress conditions. Persister cells formation has been attributed to numerous mechanisms, including stringent response and Toxin-Antitoxin (TA) systems. This study aimed to investigate the hypothetical role of TA systems in persister cells formation of Brucella strains by evaluating toxins of type II TA systems (RelE, Fic, Brn T, cogT) expression.

Brucella strains treated with a lethal dose of gentamicin and ampicillin and to determine the number of surviving cells, bacterial colonies were counted at different time intervals. The role of TA systems in persister cell formation was then determined by toxin expression levels using qRT- PCR method.

Our results showed the viability of persister cells after 7 h. The results of relative qRT- PCR showed higher levels of toxin gene expression due to stress conditions, suggesting the possible role of TA systems in persister cells formation and antibiotics tolerance.

The results of this study showed that considering the importance of persistence and the tolerance to antibiotics, further studies on persister cells formation and related genes such as the TA system genes in Brucella strains might help us to identify the precise mechanisms leading to persister cells formation.

Vaccination is one of the most effective means to protect humans and animals against brucellosis. Live attenuated Brucella vaccines are considered effective in animals but they may be potentially infectious to humans, so it is vital to improve the immunoprotective effects and safety of vaccines against Brucella. This study was designed to evaluate the immunogenicity of DNA vaccines encoding B. melitensis outer membrane proteins (Omp25 and Omp31) against B. melitensis Rev1 in a mouse model.
For this propose, Omp25 and Omp31 genes were cloned (individually and together) into the eukaryotic expression vector pcDNA3.1/Hygro (). Expressions of recombinant plasmids were confirmed by SDS-PAGE and Western blot analysis. Six groups of BALB/c mice (seven mice per group) were intramuscularly injected with three recombinant constructs, native pcDNA3.1/Hygro () and phosphate-buffered saline (PBS) as controls and subcutaneous injection of attenuated live vaccine Rev1.
Results indicated that DNA vaccine immunized BALB/c mice had a dominant immunoglobulin G response and elicited a T-cell-proliferative response and induced significant levels of interferon gamma (INF-γ) compared to the control groups.
Collectively, these finding suggested that the pcDNA3.1/Hygro DNA vaccines encoding Omp25 and Omp31 genes and divalent plasmid were able to induce both humoral and cellular immunity, and had the potential to be a vaccine candidate for prevention of B. melitensis infections.

Brucellosis is a zoonotic infectious disease with worldwide distribution, especially in the south and central American countries, the Middle-East and the Mediterranean areas. Knee prosthesis infection due to Brucella spp. is very rare with the first case reported in 1991 and the ninth case reported in 2010.
Here is reported a case of a 68-year-old female patient, referring to Shafa Orthopedic hospital, Tehran, Iran, complaining about a discharge from right total knee arthroplasty. All of the knee joint aspirations and laboratory tests were negative for infection. Initially, no clear reason was found for this painful operated knee and it was decided to revise it; however, intra-operative samples were positive for Brucella melitensis. Unfortunately, serum indicators of Brucellosis (Wright, Coombs Wright and 2-mercaptoethanol (2ME) tests) had not been checked in the preoperative evaluations. After six months of antibiotic therapy for brucellosis, a second stage revision surgery was performed successfully.
Prosthetic infection by Brucella species is very uncommon, this is the tenth case of total knee prosthesis infection with Brucella spp. reported in the literature but all orthopedic surgeons, especially those who work in the endemic areas, should evaluate a suspected joint for brucellosis.

Brucellosis is a widespread zoonotic disease causing considerable economic and public health problems. Despite animal vaccination, brucellosis remains endemic in some areas such as Iran, especially in the western Iranian province of Hamadan. We sought to detect some of the most common virulence-associated genes in Brucella isolated from human blood cultures to determine the prevalence of some virulence genes among Brucella isolates. Fifty-seven isolates were studied from patients with a clinical diagnosis of brucellosis who referred to the Infectious Diseases Ward of Sina Hospital in Hamadan Province, Iran, between April 2013 and July 2014. Blood samples were collected for the diagnosis of brucellosis using the BACTEC blood culture system. All of these isolates were confirmed by the bcsp31 Brucella-specific gene. We detected 11 virulence-associated genes of Brucella, namely cβg, virB, znuA, ure, bvfA, omp25, omp31, wbkA, mviN, manA, and manB, which are important for the pathogenesis of this bacterium in the intracellular environment by multiplex PCR. Totally, 149 patients with a clinical diagnosis of brucellosis were enrolled in this study. Fifty-seven (38.3%) patients had positive blood cultures. On biochemical and molecular testing, all of the isolates were Brucella melitensis. Ten of the virulence genes were detected among all of the 57 isolates, but the bvf gene was detected in 53 (93%) isolates. The high prevalence of virulence-associated genes among the Brucella isolates detected in Hamadan Province, Iran, underscores the pathogenicity of this bacterium in this region.

Aims: The aim of this study was to evaluate the antibacterial effects of aqueous and organic extracts of Arctium lappa on Brucella melitensis 16M in vitro, in macrophage culture and in the animal model.
In this experimental study aquatic, ethanolic, and acetonic extracts of Arctium lappa were prepared. The antibacterial effect of the extracts investigated by agar well diffusion and macrodilutionon methods for determination of MIC and MBC. Then the intramacrophge survival of the B.melitensis 16M was studied from the cell culture of Balb/c mice. Also, the antibacterial effect of the extracts were studied in the animal model.
The MIC and MBC of leaves and inflorescences extracts of Arctium lappa on B. melitensis 16 M were 101 and 116 mg/ml, respectively. The maximum inhibition zone diameter was related to an ethanolic extract. In the macrophage culture and in the animal model, the aquatic extract of inflorescences of Arctium lappa was the most effective.
The aquatic and organic extracts of Arctium lappa have antibacterial activity against intramacrophage B. Melitensis 16M. The aquatic extract has the most effective antimicrobial activity on intramacrophage B. Melitensis 16M. These extracts can be useful in the treatment of brucellosis.