Laboratory exposures to brucellae and implications for bioterrorism

Brucellosis: Unveiling the complexities of a pervasive zoonotic disease and its global impacts

One zoonotic infectious animal disease is brucellosis. The bacteria that cause brucellosis belong to the genus Brucella. Numerous animal and human species are affected by brucellosis, with an estimated 500,000 human cases recorded annually worldwide. The occurrence of new areas of infection and the resurgence of infection in already infected areas indicate how dynamically brucellosis is distributed throughout different geographic regions. Bacteria originate from the blood and are found in the reticuloendothelial system, the liver, the spleen, and numerous other locations, including the joints, kidneys, heart, and genital tract. Diagnosis of this disease can be done by bacterial isolation, molecular tests, modified acid-fast stain, rose bengal test (RBT), milk ring test, complement fixation test, enzyme-linked immunosorbent assay, and serum agglutination test. The primary sign of a Brucella abortus infection is infertility, which can result in abortion and the birth of a frail fetus that may go on to infect other animals. In humans, the main symptoms are acute febrile illness, with or without localization signs, and chronic infection. Female cattle have a greater risk of contracting Brucella disease. Human populations at high risk of contracting brucellosis include those who care for cattle, veterinarians, slaughterhouse employees, and butchers. Antibiotic treatment of brucellosis is often unsuccessful due to the intracellular survival of Brucella and its adaptability in macrophages. A "one health" strategy is necessary to control illnesses like brucellosis.

A follow-up study of 100 patients with acute brucellosis for its prognosis and prevention

Objective

To prevent chronic brucellosis, this study analysed the changes in patient antibody titers, and the trajectories of biochemical indicators at different stages of brucellosis, identified relevant biomarkers, and explored risk factors affecting the prognosis of brucellosis patients.

Methods

A prospective cohort study was conducted to follow 100 patients with acute brucellosis. Laboratory serological test results [taken with a serum (tube) agglutination test (SAT)] and biochemical parameters (liver function, renal function, and hematological system) were measured repeatedly at four-time points: 0 weeks-baseline survey, 6 weeks after the first treatment, 12 weeks after the second treatment, and 3 months after the third treatment. The changes in the antibody titres and biochemical parameters at each time point were analysed for trend changes.

Results

One hundred patients with acute brucellosis were enrolled in this follow-up study, with 100% retention in follow-up. By the third follow-up, 21 patients had turned subacute and 11 had turned chronic. One-way repeated measures analysis of variance results showed statistically significant differences (p < 0.01) across the time points for the following five indicators: alanine aminotransferase, aspartate aminotransferase, total bilirubin, serum creatinine (SCr) and platelet count. The clinical symptoms of patients in the acute stage were mainly joint pain, fatigue, and fever, while those in the chronic stage complained primarily of joint pain and fatigue. The results of multivariate logistic analysis showed that joint pain [odds ratio (OR) = 3.652, 95% confidence interval (CI) =1.379-9.672], monoarticular pain (OR = 6.356, 95% CI = 4.660-8.669), elevated SCr (OR = 15.804, 95% CI = 1.644-151.966) and elevated haemoglobin (Hb) (OR = 1.219, 95% CI = 1.065-1.736) were risk factors for poor prognosis (not cured or chronic) in patients with brucellosis.

Conclusion

The trajectory of changes in patient SAT posirates and antibody titers can be used to distinguish patients with chronic brucellosis. The brucellosis is preventable and treatable, and the standard treatment can be effective in reducing the clinical symptoms of affected patients. If patients are not treated in a timely manner, joint pain, monoarticular pain, and elevated SCr are risk factors for patients who are not cured. Therefore, the treatment cycle for these patients should be extended.

Santos R, Brito CB, Ferrero MC, Ortiz Wilczyñski JM, Silva EAC, C. Oliveira S, Baldi PC. Role of the cGAS/STING pathway in the control of Brucella abortus infection acquired through the respiratory route

Despite the importance of the respiratory route for Brucella transmission, the lung immune response to this pathogen is scarcely characterized. We investigated the role of the cGAS/STING pathway of microbial DNA recognition in the control of respiratory Brucella infection. After in vitro B. abortus infection, CFU numbers were significantly higher in alveolar macrophages (AM) and lung explants from STING KO mice than in samples from wild type (WT) mice, but no difference was observed for cGAS KO samples. CFU were also increased in WT AM and lung epithelial cells preincubated with the STING inhibitor H151. Several proinflammatory cytokines (TNF-α, IL-1β, IL-6, IP-10/CXCL10) were diminished in Brucella-infected lung explants and/or AM from STING KO mice and cGAS KO mice. These cytokines were also reduced in infected AM and lung epithelial cells pretreated with H151. After intratracheal infection with B. abortus, STING KO mice exhibited increased CFU in lungs, spleen and liver, a reduced expression of IFN-β mRNA in lungs and spleen, and reduced levels of proinflammatory cytokines and chemokines in bronchoalveolar lavage fluid (BALF) and lung homogenates. Increased lung CFU and reduced BALF cytokines were also observed in cGAS KO mice. In summary, the cGAS/STING pathway induces the production of proinflammatory cytokines after respiratory Brucella infection, which may contribute to the STING-dependent control of airborne brucellosis.

A systematic analysis of and recommendations for public health events involving brucellosis from 2006 to 2019 in China

Brucellosis is a severe public health problem in China. However, analysis on related infection events is lacking. We performed a systematic analysis of brucellosis laboratory infection and vaccine infection events from 2006 to 2019 in China based on the published literatures. Our analysis showed that most laboratoryBrucellainfections in hospitals were found in Southern China. The identification and handling of suspected samples ofBrucellainfection without following the recommended biosafety protection was the main risk factor. It is important to strengthen the preventive awareness of clinical laboratory staff and physicians, while highlighting the compulsory handling and identification of suspectedBrucella-infected samples in biosafety facilities and following biosafety practices. However, a severe Brucella infection accident at the Northeast Agricultural University, with 28 positive cases, showed that strengthening the management in teaching experiments of students in the veterinary-related profession is essential. However, cluster S2 vaccine strain infection events caused by vaccination and production were mainly observed in Northern China. Strengthening vaccination skills, personal protection, and improving the biosafety management of vaccine production and implementing regular risk surveillance is mandatory. Our analysis provides helpful clues for control of public health events involving brucellosis, as well as implementing intervention strategies is urgent.

Human brucellosis and fever of unknown origin

BACKGROUND

Human brucellosis has become one of the major public health problems in China, and increases atypical manifestations, such as fever of unknown origin (FUO), and misdiagnosis rates has complicated the diagnosis of brucellosis. To date, no relevant study on the relationship between brucellosis and FUO has been conducted.

METHODS

We retrospectively reviewed the medical charts of 35 patients with confirmed human brucellosis and prospectively recorded their outcomes by telephone interview. The patients were admitted to the Second Affiliated Hospital of Nanchang University between January 01, 2013 and October 31, 2019. Patient data were collected from hospital medical records.

RESULTS

The percentage of males was significantly higher than that of female in FUO (78.95% vs. 21.05%, P < 0.05), and 80% of the patients had a clear history of exposure to cattle and sheep. Moreover, 19 (54%) cases were hospitalized with FUO, among which the patients with epidemiological histories were significantly more than those without (P < 0.05). The incidence of toxic hepatitis in FUO patients was higher than that in non-FUO patients (89% vs. 50%, P < 0.05). Meanwhile, the misdiagnosis rate was considerably higher in the FUO group than in the non-FUO group (100% vs. 63%; P < 0.05).

CONCLUSION

Brucellosis is predominantly FUO admission in a non-endemic area of China, accompanied by irregular fever and toxic hepatitis. Careful examination of the epidemiological history and timely improvement of blood and bone marrow cultures can facilitate early diagnosis and prevent misdiagnosis.

The Lanzhou Brucella Leak: The Largest Laboratory Accident in the History of Infectious Diseases?

An inadequacy in sanitizing processes in a biopharmaceutical plant in Lanzhou, China, during July and August 2019, led to the aerosolization of Brucella that was subsequently spread through wind to nearby settlements and academic institutes, resulting in >10 000 human brucellosis cases, as of November 2020. The leak, possibly the largest laboratory accident in the history of infectious diseases, underlines the particular characteristics of Brucella that have made the pathogen a historical entity in biodefense research and a major cause of laboratory-associated infections. It further underlines the need for enhanced vigilance and strict regulatory interventions in similar facilities.

Evaluation of immune responses to Brucella vaccines in mouse models: A systematic review

Introduction

Despite the accessibility of several live attenuated vaccines for animals, currently, there is no licensed vaccine for brucellosis in human populations. Available and confirmed animal vaccines may be harmful and considered inappropriate for humans. Thus, human vaccines for brucellosis are required. We aimed to evaluate the effects of Brucella vaccines on mouse models and discuss the potential mechanisms of these vaccines for the design of the appropriate human vaccines.

Materials and methods

A systematic search was carried out in Web of Science, Embase, and PubMed/Medline databases. The following MeSH terms were applied: brucellosis, vaccine, Brucella, and vaccination. The original manuscripts describing the Brucella vaccines on mouse models were included. The review articles, editorials, correspondences, case reports, case series, duplicate publications, and articles with insufficient data were excluded.

Results

Of the 163 full texts that were screened, 17 articles reached to inclusion criteria. Combining the results of these trials revealed a reduction in bacterial load and colonization rate of Brucella in the spleen, an increase in inflammatory markers, especially IFN-γ and IL-4, and the highest levels of antibody classes in vaccinated animals compared to animals challenged with various virulent strains of Brucella. The majority of studies found that different anti-Brucella vaccines induced a significant protective effect in animals challenged with Brucella strains. Additionally, mice were given the highest level of Brucella vaccine protection and significant clearance of Brucella strains when the immunization was delivered via the IP (intraperitoneal) or IP-IN (intranasal) routes.

Conclusion

Brucella is responsible for half-million new cases globally annually, and the lack of a proper human vaccine poses the risk of brucellosis. A variety of vaccines are used to prevent brucellosis. Subunit vaccines and recombinant human vaccines have higher safety and protective properties. Although vaccination helps brucellosis control, it does not eradicate the disease. Thus, we recommend the following strategies. (a) establishment of a registration system; (b) close monitoring of slaughterhouses, markets, and herds; (c) training veterinarians; (d) legal protection of the consequences of non-compliance with preventive measures.

Cross-Sectional Study of Seroprevalence and Associated Risk Factors of Bovine Brucellosis in Selected Districts of Jimma Zone, South Western Oromia, Ethiopia

Bovine brucellosis is one of the most widespread but neglected zoonotic diseases in developing countries where it is an endemic and growing problem causing public health impacts. Developing a cost-effective control strategy of the disease can only be guaranteed by knowledge of the disease epidemiology that defines its risk profiles. Hence, this study was designed to evaluate epidemiological aspects of bovine brucellosis in selected districts of Jimma zone. A cross-sectional study with multistage sampling techniques was conducted on 424 cattle to evaluate its seroprevalence. Likewise, 114 households were included for the investigation of risk factors. SPSS version 20 for data analysis and C-ELISA test for antibody detection were used. Moreover, the chi-square test for univariable analysis and logistic regression model for multivariable analysis were employed to assess association between seropositivity and risk factors. From this study, 3.3% (95% CI: 1.82-5.48) and 12.3% (95% CI: 6.88-19.75) seroprevalence of the disease was detected with the highest proportion found at Kersa district (6.5 (95% CI: 1.37-17.90) and (21.4 (95% CI: 4.66-50.80)) followed by Seka Chokorsa (1.76 (95% CI: 0.37-5.07) and (6.7 (95% CI: 1.40-18.27)) and Mana (1.75 (95% CI: 0.21-6.20) and (7.1 (95% CI: 0.88-23.50)) at individual animals and herd levels, respectively. Cattle of poor body condition, pregnant, and cows with history of abortion and repeat breeding were found 4.8 (95% CI: 2.00-22.74), 4.3 (95% CI: 1.43-13.04), 3.3 (95% CI: 1.07-10.21), and 2.7 (95% CI: 1.86-8.15) times more likely seropositive than their counterparts, respectively. Besides these, mixed feeding style was highly associated with seropositive reactors than separate feeding (AOR = 8.3; 95% CI: 1.76-38.99). These findings depicted substantial areas to be addressed in implementation of appropriate and immediate control actions and establishment of intervention mechanisms of bovine brucellosis.

Immunization with a combination of recombinant Brucella abortus proteins induces T helper immune response and confers protection against wild-type challenge in BALB/c mice

Protective efficiency of a combination of four recombinant Brucella abortus (B. abortus) proteins, namely, ribosomal protein L7/L12, outer membrane protein (OMP) 22, OMP25 and OMP31, was evaluated as a combined subunit vaccine (CSV) against B. abortus infection in RAW 264.7 cell line and murine model. Four proteins were cloned, expressed and purified, and their immunocompetence was analysed. BALB/c mice were immunized subcutaneously with single subunit vaccines (SSVs) or CSV. Cellular and humoral immune responses were determined by ELISA. Results of immunoreactivity showed that these four recombinant proteins reacted with Brucella‐positive serum individually but not with Brucella‐negative serum. A massive production of IFN‐γ and IL‐2 but low degree of IL‐10 was observed in mice immunized with SSVs or CSV. In addition, the titres of IgG2a were heightened compared with IgG1 in SSV‐ or CSV‐immunized mice, which indicated that SSVs and CSV induced a typical T‐helper‐1‐dominated immune response in vivo. Further investigation of the CSV showed a superior protective effect in mice against brucellosis. The protection level induced by CSV was significantly higher than that induced by SSVs, which was not significantly different compared with a group immunized with RB51. Collectively, these antigens of Brucella could be potential candidates to develop subunit vaccines, and the CSV used in this study could be a potential candidate therapy for the prevention of brucellosis.

Proteomics-based screening and antibiotic resistance assessment of clinical and sub-clinical Brucella species: An evolution of brucellosis infection control

Brucellae are intracellular sneaky bacteria and they can elude the host's defensive mechanisms, resulting in therapeutic failure. Therefore, the goal of this investigation was to rapid identification of Brucella species collected from animals and humans in Saudi Arabia, as well as to evaluate their resistance to antibiotics. On selective media, 364 animal samples as well as 70 human blood samples were cultured. Serological and biochemical approaches were initially used to identify a total of 25 probable cultured isolates. The proteomics of Brucella species were identified using the MALDI Biotyper (MBT) system, which was subsequently verified using real-time polymerase chain reaction (real-time PCR) and microfluidic electrophoresis assays. Both Brucella melitensis (B. melitensis) and Brucella abortus (B. abortus) were tested for antimicrobial susceptibility using Kirby Bauer method and the E-test. In total, 25 samples were positive for Brucella and included 11 B. melitensis and 14 B. abortus isolates. Twenty-two out of 25 (88%) and 24/25 (96%) of Brucella strains were recognized through the Vitek 2 Compact system. While MBT was magnificently identified 100% of the strains at the species level with a score value more than or equal to 2.00. Trimethoprim-sulfamethoxazole, rifampin, ampicillin-sulbactam, and ampicillin resistance in B. melitensis was 36.36%, 31.82%, 27.27%, and 22.70%, respectively. Rifampin, trimethoprim-sulfamethoxazole, ampicillin, and ampicillin-sulbactam resistance was found in 35.71%, 32.14%, 32.14%, and 28.57% of B. abortus isolates, correspondingly. MBT confirmed by microfluidic electrophoresis is a successful approach for identifying Brucella species at the species level. The resistance of B. melitensis and B. abortus to various antibiotics should be investigated in future studies.

Microbiological Laboratory Diagnosis of Human Brucellosis: An Overview

Brucella spp. are Gram-negative, non-motile, non-spore-forming, slow-growing, facultative intracellular bacteria causing brucellosis. Brucellosis is an endemic of specific geographic areas and, although underreported, represents the most common zoonotic infection, with an annual global incidence of 500,000 cases among humans. Humans represent an occasional host where the infection is mainly caused by B. melitensis, which is the most virulent; B. abortus; B. suis; and B. canis. A microbiological analysis is crucial to identifying human cases because clinical symptoms of human brucellosis are variable and aspecific. The laboratory diagnosis is based on three different microbiological approaches: (i) direct diagnosis by culture, (ii) indirect diagnosis by serological tests, and (iii) direct rapid diagnosis by molecular PCR-based methods. Despite the established experience with serological tests and highly sensitive nucleic acid amplification tests (NAATs), a culture is still considered the “gold standard” in the laboratory diagnosis of brucellosis due to its clinical and epidemiological relevance. Moreover, the automated BC systems now available have increased the sensitivity of BCs and shortened the time to detection of Brucella species. The main limitations of serological tests are the lack of common interpretative criteria, the suboptimal specificity due to interspecies cross-reactivity, and the low sensitivity during the early stage of disease. Despite that, serological tests remain the main diagnostic tool, especially in endemic areas because they are inexpensive, user friendly, and have high negative predictive value. Promising serological tests based on new synthetic antigens have been recently developed together with novel point-of-care tests without the need for dedicated equipment and expertise. NAATs are rapid tests that can help diagnose brucellosis in a few hours with high sensitivity and specificity. Nevertheless, the interpretation of NAAT-positive results requires attention because it may not necessarily indicate an active infection but rather a low bacterial inoculum, DNA from dead bacteria, or a patient that has recovered. Refined NAATs should be developed, and their performances should be compared with those of commercial and home-made molecular tests before being commercialized for the diagnosis of brucellosis. Here, we review and report the most common and updated microbiological diagnostic methods currently available for the laboratory diagnosis of brucellosis.

Global Comprehensive Literature Review and Meta-Analysis of Brucella spp. in Swine Based on Publications From 2000 to 2020

Background: Brucellosis, a zoonotic disease, infects various hosts, including swine and humans. It has reemerged in recent years as a public health concern, and current studies on brucellosis infection in swine have been conducted worldwide. However, no meta-analyses of global brucellosis infection in swine have been published. The aim of this study was to provide an overview of Brucella species (spp.) in swine worldwide and the factors associated with its persistence.

Results: We searched seven databases for published epidemiological studies on brucellosis in pigs, including the Chinese National Knowledge Infrastructure, Wanfang Data, SpringerLink, ScienceDirect, Web of Science, the VIP Chinese Journal Database and PubMed. We selected 119 articles published from January 1, 2000 to January 3, 2020 for inclusion in the meta-analysis and analyzed the data using a random-effects model. Funnel plots and Egger's test showed significant publication bias in the included studies. The results of the sensitivity analysis showed that our study was relatively stable and reliable. The prevalence of brucellosis in swine was 2.1% (95% CI: 1.6–2.6), of which the highest infection rate, which was found in Europe, was 17.4% (95% CI: 11.1–24.9). The prevalence in feral pigs (15.0%, 95% CI: 8.4–23.2) was higher than that in domestic pigs (1.1%, 95% CI 0.2–2.5). The prevalence in high-income countries (15.7%, 95% CI 8.0–25.3) was significantly higher than that in middle- (0.8%, 95% CI 0.5–1.1), and low-income countries (0.1%, 95% CI 0.0–0.2). The prevalence was highest in finishing pigs at 4.9% (95% CI 0.9–11.0), and lowest among suckling pigs at 0% (95% CI 0.0–0.5).

Conclusion: The Brucella prevalence in pig herds currently is distributed widely throughout the world. In some countries, swine brucellosis may be a neglected zoonotic disease. We recommend long-term monitoring of the prevalence of brucellosis in domestic and wild pig herds. Attention should also be paid to animal welfare on intensive pig farms; controlling the breeding density may play an important role in reducing the spread of brucellosis among pigs.

Update on Biosafety and Emerging Infections for the Clinical Microbiology Laboratory

Biosafety risks are prevalent in all areas of the clinical laboratories. Clinical laboratorians have become accustomed to accepting these risks. When an emerging pathogen appears, the concerns become elevated. Since the appearance of Ebola virus in the United States in 2014, biosafety practices have made progress. A recent Association of Public Health Laboratories survey shows that clinical laboratories are unprepared for current and emerging biosafety challenges. This article focuses on the biosafety program that clinical laboratory leaders should build to meet the needs of clinical laboratories; biosafety challenges of automated laboratory systems, facilities, personnel, and practices; and the relationship with occupational health.

Biowarfare, bioterrorism and biocrime: A historical overview on microbial harmful applications

Microbial Forensics is a field that continues to grow in interest and application among the forensic community. This review, divided into two sections, covers several topics associated with this new field. The first section presents a historic overview concerning the use of microorganisms (or its product, i.e. toxins) as harmful biological agents in the context of biological warfare (biowarfare), bioterrorism, and biocrime. Each case is illustrated with the examination of case reports that span from prehistory to the present day. The second part of the manuscript is devoted to the role of MF and highlights the necessity to prepare for the pressing threat of the harmful use of biological agents as weapons. Preventative actions, developments within the field to ensure a timely and effective response and are discussed herein.

Occupational exposure to Brucella spp.: A systematic review and meta-analysis

Brucellosis is a neglected zoonotic disease of remarkable importance worldwide. The focus of this systematic review was to investigate occupational brucellosis and to identify the main infection risks for each group exposed to the pathogen. Seven databases were used to identify papers related to occupational brucellosis: CABI, Cochrane, Pubmed, Scielo, Science Direct, Scopus and Web of Science. The search resulted in 6123 studies, of which 63 were selected using the quality assessment tools guided from National Institutes of Health (NIH) and Case Report Guidelines (CARE). Five different job-related groups were considered greatly exposed to the disease: rural workers, abattoir workers, veterinarians and veterinary assistants, laboratory workers and hunters. The main risk factors and exposure sources involved in the occupational infection observed from the analysis of the articles were direct contact with animal fluids, failure to comply with the use of personal protective equipment, accidental exposure to live attenuated anti-brucellosis vaccines and non-compliance with biosafety standards. Brucella species frequently isolated from job-related infection were Brucella melitensis, Brucella abortus, Brucella suis and Brucella canis. In addition, a meta-analysis was performed using the case-control studies and demonstrated that animal breeders, laboratory workers and abattoir workers have 3.47 [95% confidence interval (CI); 1.47-8.19] times more chance to become infected with Brucella spp. than others individuals that have no contact with the possible sources of infection. This systematic review improved the understanding of the epidemiology of brucellosis as an occupational disease. Rural workers, abattoir workers, veterinarians, laboratory workers and hunters were the groups more exposed to occupational Brucella spp. infection. Moreover, it was observed that the lack of knowledge about brucellosis among frequently exposed professionals, in addition to some behaviors, such as negligence in the use of individual and collective protective measures, increases the probability of infection.

Brucella Exposure Risk Events in 10 Clinical Laboratories, New York City, USA, 2015 to 2017

From 2015 to 2017, 11 confirmed brucellosis cases were reported in New York City, leading to 10 Brucella exposure risk events (Brucella events) in 7 clinical laboratories (CLs). Most patients had traveled to countries where brucellosis is endemic and presented with histories and findings consistent with brucellosis. CLs were not notified that specimens might yield a hazardous organism, as the clinicians did not consider brucellosis until they were notified that bacteremia with Brucella was suspected. In 3 Brucella events, the CLs did not suspect that slow-growing, small Gram-negative bacteria might be harmful. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), which has a limited capacity to identify biological threat agents (BTAs), was used during 4 Brucella events, which accounted for 84% of exposures. In 3 of these incidents, initial staining of liquid media showed Gram-positive rods or cocci, including some cocci in chains, suggesting streptococci. Over 200 occupational exposures occurred when the unknown isolates were manipulated and/or tested on open benches, including by procedures that could generate infectious aerosols. During 3 Brucella events, the CLs examined and/or manipulated isolates in a biological safety cabinet (BSC); in each CL, the CL had previously isolated Brucella Centers for Disease Control and Prevention recommendations to prevent laboratory-acquired brucellosis (LAB) were followed; no seroconversions or LAB cases occurred. Laboratory assessments were conducted after the Brucella events to identify facility-specific risks and mitigations. With increasing MALDI-TOF MS use, CLs are well-advised to adhere strictly to safe work practices, such as handling and manipulating all slow-growing organisms in BSCs and not using MALDI-TOF MS for identification until BTAs have been ruled out.

An accidental laboratory exposure to Brucella melitensis: the prospective post-exposure management and a detailed investigation into the nature of the exposure

Our aim was to prospectively manage 22 Brucella-exposed individuals and identify the lapses in laboratory practices that lead to the exposure. The exposed individuals were risk-stratified, assessed for post-exposure prophylaxis (PEP), counselled to self-monitor symptoms and followed-up with three serology tests. Staff laboratory practices were recorded. Ten out of 13 high-risk individuals received PEP within 48 h of exposure. Compliance with PEP and serology monitoring was 90 and 96 %, respectively. No brucellosis cases were documented. A single handler manipulated the Brucella isolate on the open bench. Movement of the isolate was tracked in detail, highlighting various points of laboratory non-conformance. Early PEP intervention is effective in preventing acquired brucellosis. Our pragmatic post-exposure management achieved high PEP and serology compliance. We experience first-hand how regular staff engagement motivated PEP adherence and interval blood sampling attendance. The enforcement of practical strategies and safety practices was also implemented without compromising our laboratory processing times.

Laboratory Diagnosis of Human Brucellosis

The clinical presentation of brucellosis in humans is variable and unspecific, and thus, laboratory corroboration of the diagnosis is essential for the patient's proper treatment. The diagnosis of brucellar infections can be made by culture, serological tests, and nucleic acid amplification assays. Modern automated blood culture systems enable detection of acute cases of brucellosis within the routine 5- to 7-day incubation protocol employed in clinical microbiology laboratories, although a longer incubation and performance of blind subcultures may be needed for protracted cases. Serological tests, though they lack specificity and provide results that may be difficult to interpret in individuals repeatedly exposed to Brucella organisms, nevertheless remain a diagnostic cornerstone in resource-poor countries. Nucleic acid amplification assays combine exquisite sensitivity, specificity, and safety and enable rapid diagnosis of the disease. However, long-term persistence of positive molecular test results in patients that have apparently fully recovered is common and has unclear clinical significance and therapeutic implications. Therefore, as long as there are no sufficiently validated commercial tests or studies that demonstrate an adequate interlaboratory reproducibility of the different homemade PCR assays, cultures and serological methods will remain the primary tools for the diagnosis and posttherapeutic follow-up of human brucellosis.

Brucellosis in Dogs and Public Health Risk

Brucella canis infects dogs and humans. In dogs, it can cause reproductive failure; in humans, it can cause fever, chills, malaise, peripheral lymphadenomegaly, and splenomegaly. B. canis infection in dogs is underrecognized. After evaluating serologic data, transmission patterns, and regulations in the context of brucellosis in dogs as an underrecognized zoonosis, we concluded that brucellosis in dogs remains endemic to many parts of the world and will probably remain a threat to human health and animal welfare unless stronger intervention measures are implemented. A first step for limiting disease spread would be implementation of mandatory testing of dogs before interstate or international movement.

Learning from the master: targets and functions of the CtrA response regulator in Brucella abortus and other alpha-proteobacteria

The α-proteobacteria are a fascinating group of free-living, symbiotic and pathogenic organisms, including the Brucella genus, which is responsible for a worldwide zoonosis. One common feature of α-proteobacteria is the presence of a conserved response regulator called CtrA, first described in the model bacterium Caulobacter crescentus, where it controls gene expression at different stages of the cell cycle. Here, we focus on Brucella abortus and other intracellular α-proteobacteria in order to better assess the potential role of CtrA in the infectious context. Comparative genomic analyses of the CtrA control pathway revealed the conservation of specific modules, as well as the acquisition of new factors during evolution. The comparison of CtrA regulons also suggests that specific clades of α-proteobacteria acquired distinct functions under its control, depending on the essentiality of the transcription factor. Other CtrA-controlled functions, for instance motility and DNA repair, are proposed to be more ancestral. Altogether, these analyses provide an interesting example of the plasticity of a regulation network, subject to the constraints of inherent imperatives such as cell division and the adaptations to diversified environmental niches.

IL-1R and Inflammasomes Mediate Early Pulmonary Protective Mechanisms in Respiratory Brucella Abortus Infection

Brucella spp. infection is frequently acquired through contaminated aerosols. The role of interleukin-1 beta (IL-1β) in the early pulmonary response to respiratory Brucella infection is unknown. As shown here, IL-1β levels in lung homogenates and bronchoalveolar lavage fluid (BALF) of mice intratracheally inoculated with B. abortus were increased at 3 and 7 days p.i. At 7 days p.i., pulmonary CFU numbers were higher in IL-1 receptor (IL-1R) knockout (KO) mice than in wild type (WT) mice. At different times p.i. CFU in lungs and BALF were higher in mice lacking some inflammasome components (caspase-1, AIM2, NLRP3) than in WT mice. At 2 days p.i. pulmonary levels of IL-1β and CXCL1 (neutrophils chemoattractant) were lower in caspase-1/11 KO mice. At day 3 p.i., neutrophils counts in BALF were lower in caspase-1/11 KO mice than in WT mice. During in vitro infections, IL-1β secretion was lower in alveolar macrophages from caspase-1/11, NLRP3 or AIM2 KO mice than in WT controls. Similarly, IL-1β production by B. abortus-infected alveolar epithelial cells was reduced by pretreatment with a specific caspase-1 inhibitor. This study shows that IL-1R, probably through IL-1β action, and the NLRP3 and AIM2 inflammasomes are involved in pulmonary innate immune protective mechanisms against respiratory B. abortus infection.

Allergic Asthma Favors Brucella Growth in the Lungs of Infected Mice

Allergic asthma is a chronic Th2 inflammatory disease of the lower airways affecting a growing number of people worldwide. The impact of infections and microbiota composition on allergic asthma has been investigated frequently. Until now, however, there have been few attempts to investigate the impact of asthma on the control of infectious microorganisms and the underlying mechanisms. In this work, we characterize the consequences of allergic asthma on intranasal (i.n.) infection by Brucella bacteria in mice. We observed that i.n. sensitization with extracts of the house dust mite Dermatophagoides farinae or the mold Alternaria alternata (Alt) significantly increased the number of Brucella melitensis, Brucella suis, and Brucella abortus in the lungs of infected mice. Microscopic analysis showed dense aggregates of infected cells composed mainly of alveolar macrophages (CD11c+ F4/80+ MHCII+) surrounded by neutrophils (Ly-6G+). Asthma-induced Brucella susceptibility appears to be dependent on CD4+ T cells, the IL-4/STAT6 signaling pathway and IL-10, and is maintained in IL-12- and IFN-γR-deficient mice. The effects of the Alt sensitization protocol were also tested on Streptococcus pneumoniae and Mycobacterium tuberculosis pulmonary infections. Surprisingly, we observed that Alt sensitization strongly increases the survival of S. pneumoniae infected mice by a T cell and STAT6 independent signaling pathway. In contrast, the course of M. tuberculosis infection is not affected in the lungs of sensitized mice. Our work demonstrates that the impact of the same allergic sensitization protocol can be neutral, negative, or positive with regard to the resistance of mice to bacterial infection, depending on the bacterial species.

Misidentification of Risk Group 3/Security Sensitive Biological Agents by MALDI-TOF MS in Canada: November 2015-October 2017

Background

Matrix-Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) is a technology increasingly used in diagnostic identification of microorganisms. However, anecdotal evidence suggests that this technology is associated with misidentification of Risk Group 3 (RG3)/Security Sensitive Biological Agents (SSBA) resulting in exposure risks to laboratory personnel.

Objective

To investigate and characterize incidents related to the use of MALDI-TOF MS in Canada between November 6, 2015, and October 10, 2017.

Methods

Cases were identified from laboratory incident reports in the national Laboratory Incident Notification Canada (LINC) surveillance system. Eligible cases referred directly to MALDI-TOF MS or one of three RG3/SSBA organisms, Brucella species, Francisella tularensis and Burkholderia pseudomallei. A questionnaire was developed to identify potential risk factors leading to the exposure. Reporters from organizations with selected incidents were interviewed using the questionnaire. Data were entered into an Excel spreadsheet and standard descriptive statistical analysis performed to assess common characteristics and identify possible risk factors.

Results

There were eight eligible incidents and a total of 39 laboratory workers were exposed to RG3/SSBA organisms. In five (out of eight) of the incidents, the reporters indicated that their device was equipped with both clinical and research reference libraries. For six incidents where reporters knew the type of library used, only the clinical library was employed at the time of the incident even though both libraries were available in five of these incidents. In all eight cases, the exposure occurred during the sample preparation stage with analyses performed on an open bench and directly from the specimen. And in all eight cases, patient specimens were received without information regarding potential risk.

Conclusion

This first national study characterizing the nature and extent of laboratory incidents involving RG3/SSBA that are related to the use of MALDI-TOF MS identifies risk factors and provides baseline data that can inform mitigation strategies.

Btp Proteins from Brucella abortus Modulate the Lung Innate Immune Response to Infection by the Respiratory Route

Although inhalation of infected aerosols is a frequent route for Brucella infection in humans, it rarely causes pulmonary clinical manifestations, suggesting a mild or nearly absent local inflammatory response. The goal of this study was to characterize the early innate immune response to intratracheal infection with Brucella abortus in mice and to evaluate whether it is modulated by this pathogen. After infection with 10⁶ CFU of B. abortus, the pulmonary bacterial burden at 7 days post-infection (p.i.) was comparable to the initial inoculum, despite an initial transient decline. Brucella was detected in spleen and liver as early as 1 day p.i. IL-1β and MCP-1 increased at 3 days p.i., whereas IL-12, KC, TNF-α, and IFN-γ only increased at 7 days p.i. Histological examination did not reveal peribronchial or perivascular infiltrates in infected mice. Experiments were conducted to evaluate if the limited inflammatory lung response to B. abortusis caused by a bacterial mechanism of TLR signaling inhibition. Whereas inoculation of E. coli LPS to control mice [phosphate-buffered saline (PBS)/LPS] caused lung inflammation, almost no histological changes were observed in mice preinfected intratracheally with B. abortus (WT/LPS). We speculated that the Brucella TIR-containing proteins (Btps) A and B, which impair TLR signaling in vitro, may be involved in this modulation. After LPS challenge, mice preinfected with the B. abortus btpAbtpB double mutant exhibited a stronger pulmonary polymorphonuclear infiltrate than WT/LPS mice, although milder than that of the PBS/LPS group. In addition, lungs from B. abortus btpAbtpB-infected mice presented a stronger inflammatory infiltrate than those infected with the WT strain, and at day 7 p.i., the pulmonary levels of KC, MCP-1, and IL-12 were higher in mice infected with the mutant. This study shows that B. abortus infection produces a mild proinflammatory response in murine lungs, partially due to immune modulation by its Btp proteins. This may facilitate its survival and dissemination to peripheral organs.

Summary of Notifiable Infectious Diseases and Conditions - United States, 2015

The Summary of Notifiable Infectious Diseases and Conditions - United States, 2015 (hereafter referred to as the summary) contains the official statistics, in tabular and graphical form, for the reported occurrence of nationally notifiable infectious diseases and conditions in the United States for 2015. Unless otherwise noted, data are final totals for 2015 reported as of June 30, 2016. These statistics are collected and compiled from reports sent by U.S. state and territories, New York City, and District of Columbia health departments to the National Notifiable Diseases Surveillance System (NNDSS), which is operated by CDC in collaboration with the Council of State and Territorial Epidemiologists (CSTE). This summary is available at https://www.cdc.gov/MMWR/MMWR_nd/index.html. This site also includes summary publications from previous years.

Knowledge, attitudes and practices (KAP) relating to brucellosis in smallholder dairy farmers in two provinces in Pakistan

The present study aimed to assess the extent of knowledge and understanding of brucellosis in smallholder dairy farmers and identify practices at the farm and household level that might pose a risk for humans contracting brucellosis. Between February and June 2015 a cross-sectional study was conducted among smallholder farms (n = 420) in five districts of Punjab and two districts of Sindh province. Farmers were interviewed using a questionnaire to obtain information on farmers' knowledge about brucellosis and the potential risks for contracting the disease that are present for dairy farmers and their families. Logistic regression and ordinal logistic models were used to investigate potential predictors for risky behaviours. The results show almost all farmers (97%) were not aware of the modes of transmission of brucellosis. Relating to risk, the majority (66%) of the farmers' families were reported to consume raw milk and its products, live in shared housing with animals (49%) and not cover hand cuts during contact with animals (74%). All farmers performed at least one risky practice on a regular basis for brucellosis transmission from animal to human. A multivariable analysis highlighted that the respondents with no formal education and those who had not heard of the disease displayed greater risky behaviour. Poor understanding of the disease, presence of multiple risky practices on farm and at the household, and incorrect perception supports the need for an educational awareness program in order to ensure uptake of improved practices.

Brucellosis in a refugee who migrated from Syria to Germany and lessons learnt, 2016

A teenage woman migrating from Syria arrived in May 2015 in Germany. She gave birth to a healthy child in early 2016, but became febrile shortly after delivery. Blood cultures revealed Brucella melitensis. In retrospect, she reported contact with sheep in Syria and recurrent pain in the hip joints over about five months before diagnosis of brucellosis. We discuss consequences for adequate treatment of mother and child as well as for clinical and laboratory management.

Microbiological laboratory diagnostics of neglected zoonotic diseases (NZDs)

This review reports on laboratory diagnostic approaches for selected, highly pathogenic neglected zoonotic diseases, i.e. anthrax, bovine tuberculosis, brucellosis, echinococcosis, leishmaniasis, rabies, Taenia solium-associated diseases (neuro-/cysticercosis & taeniasis) and trypanosomiasis. Diagnostic options, including microscopy, culture, matrix-assisted laser-desorption-ionisation time-of-flight mass spectrometry, molecular approaches and serology are introduced. These procedures are critically discussed regarding their diagnostic reliability and state of evaluation. For rare diseases reliable evaluation data are scarce due to the rarity of samples. If bio-safety level 3 is required for cultural growth, but such high standards of laboratory infrastructure are not available, serological and molecular approaches from inactivated sample material might be alternatives. Multiple subsequent testing using various test platforms in a stepwise approach may improve sensitivity and specificity. Cheap and easy to use tests, usually called "rapid diagnostic tests" (RDTs) may impact disease control measures, but should not preclude developing countries from state of the art diagnostics.

Efficient production of pronuclear embryos in breeding and nonbreeding season for generating transgenic sheep overexpressing TLR4

BACKGROUND

Brucella is a zoonotic Gram-negative pathogen that causes abortion and infertility in ruminants and humans. TLR4 is the receptor for LPS which can recognize Brucella and initiate antigen-presenting cell activities that affect both innate and adaptive immunity. Consequently, transgenic sheep over-expressing TLR4 are an suitable model to investigate the effects of TLR4 on preventing Brucellosis. In this study, we generated transgenic sheep overexpressing TLR4 and aimed to evaluate the effects of different seasons (breeding and non-breeding season) on superovulation and the imported exogenous gene on growth.

RESULTS

In total of 43 donor ewes and 166 recipient ewes in breeding season, 37 donor ewes and 144 recipient ewes in non-breeding season were selected for super-ovulation and injected embryo transfer to generate transgenic sheep. Our results indicated the no. of embryos recovered of donors and the rate of pronuclear embryos did not show any significant difference between breeding and non-breeding seasons (P > 0.05). The positive rate of exogenous TLR4 tested were 21.21 % and 22.58 % in breeding and non-breeding season by Southern blot. The expression level of TLR4 in the transgenic sheep was 1.5 times higher than in the non-transgenic group (P < 0.05). The lambs overexpressing TLR4 had similar growth performance with non-transgenic lambs, and the blood physiological parameters of transgenic and non-transgenic were both in the normal range and did not show any difference.

CONCLUSIONS

Here we establish an efficient platform for the production of transgenic sheep by the microinjection of pronuclear embryos during the whole year. The over-expression of TLR4 had no adverse effect on the growth of the sheep.

Cases of human brucellosis in Sweden linked to Middle East and Africa

BACKGROUND

Human brucellosis cases are still reported each year in Sweden despite eradication of the disease in animals. Epidemiological investigation has never been conducted to trace back the source of human infection in the country. The purpose of the study was to identify the source of infection for 16 human brucellosis cases that occurred in Sweden, during the period 2008-2012.

RESULTS

The isolates were identified as Brucella melitensis and MLVA-16 genotyping revealed 14 different genotypes of East Mediterranean and Africa lineages. We also reported one case of laboratory-acquired brucellosis (LAB) that was shown to be epidemiological linked to one of the cases in the current study.

CONCLUSIONS

Brucella melitensis was the only species diagnosed, confirming its highest zoonotic potential in the genus Brucella, and MLVA-16 results demonstrated that the cases of brucellosis in Sweden herein investigated, are imported and linked to travel in the Middle East and Africa. Due to its zoonotic concerns, any acute febrile illness linked to recent travel within those regions should be investigated for brucellosis and samples should be processed according to biosafety level 3 regulations.

Systematic review of brucellosis in the Middle East: disease frequency in ruminants and humans and risk factors for human infection

A systematic review of studies providing frequency estimates of brucellosis in humans and ruminants and risk factors forBrucellaspp. seropositivity in humans in the Middle East was conducted to collate current knowledge of brucellosis in this region. Eight databases were searched for peer-reviewed original Arabic, English, French and Persian journal articles; the search was conducted on June 2014. Two reviewers evaluated articles for inclusion based on pre-defined criteria. Of 451 research articles, only 87 articles passed the screening process and provided bacteriological and serological evidence for brucellosis in all Middle Eastern countries.Brucella melitensisandB. abortushave been identified in most countries in the Middle East, supporting the notion of widespread presence ofBrucellaspp. especiallyB. melitensisacross the region. Of the 87 articles, 49 were used to provide evidence of the presence ofBrucellaspp. but only 11 provided new knowledge on the frequency of brucellosis in humans and ruminants or on human risk factors for seropositivity and were deemed of sufficient quality. Small ruminant populations in the region show seroprevalence values that are among the highest worldwide. Human cases are likely to arise from subpopulations occupationally exposed to ruminants or from the consumption of unpasteurized dairy products. The Middle East is in need of well-designed observational studies that could generate reliable frequency estimates needed to assess the burden of disease and to inform disease control policies.

CCL20 and Beta-Defensin 2 Production by Human Lung Epithelial Cells and Macrophages in Response to Brucella abortus Infection

Both CCL20 and human β-defensin 2 (hBD2) interact with the same membrane receptor and display chemotactic and antimicrobial activities. They are produced by airway epithelia in response to infectious agents and proinflammatory cytokines. Whereas Brucella spp. can infect humans through inhalation, their ability to induce CCL20 and hBD2 in lung cells is unknown. Here we show that B. abortus induces CCL20 expression in human alveolar (A549) or bronchial (Calu-6) epithelial cell lines, primary alveolar epithelial cells, primary human monocytes, monocyte-derived macrophages and the monocytic cell line THP-1. CCL20 expression was mainly mediated by JNK1/2 and NF-kB in both Calu-6 and THP-1 cells. CCL20 secretion was markedly induced in A549, Calu-6 and THP-1 cells by heat-killed B. abortus or a model Brucella lipoprotein (L-Omp19) but not by the B. abortus lipopolysaccharide (LPS). Accordingly, CCL20 production by B. abortus-infected cells was strongly TLR2-dependent. Whereas hBD2 expression was not induced by B. abortus infection, it was significantly induced in A549 cells by conditioned media from B. abortus-infected THP-1 monocytes (CMB). A similar inducing effect was observed on CCL20 secretion. Experiments using blocking agents revealed that IL-1β, but not TNF-α, was involved in the induction of hBD2 and CCL20 secretion by CMB. In the in vitro antimicrobial assay, the lethal dose (LD) 50 of CCL20 for B. abortus (>50 μg/ml) was markedly higher than that against E. coli (1.5 μg/ml) or a B. abortus mutant lacking the O polysaccharide in its LPS (8.7 ug/ml). hBD2 did not kill any of the B. abortus strains at the tested concentrations. These results show that human lung epithelial cells secrete CCL20 and hBD2 in response to B. abortus and/or to cytokines produced by infected monocytes. Whereas these molecules do not seem to exert antimicrobial activity against this pathogen, they could recruit immune cells to the infection site.

Detection and discrimination of two Brucella species by multiplex real-time PCR and high-resolution melt analysis curve from human blood and comparison of results using RFLP

OBJECTIVES

Rapid and accurate detection of Brucella abortus and Brucella melitensis from clinical samples is so important because antibiotic treatment has major side effects. This study reveals a new method in detection of clinical samples of brucellosis using real-time PCR and high-resolution melt (HRM) curve analysis.

MATERIALS AND METHODS

160 brucellosis suspicious samples with more than 1/80 serum antibody titers were collected and the results were compared with the RFLP method. In order to amplify the sequences for HRM analysis, vdcc, int-hyp and glk and for RFLP, omp2a and omp2b with PstI and Hinf1 restriction endonuclease were used. At last, the accuracy and specificity of the two methods were compared with each other.

RESULTS

Out of these 160 samples, multiplex real time PCR showed 108 positive samples (67.5%), including 56% B. melitensis and 44% B. abortus; whereas in PCR-RFLP 52 out of 160 samples were positive, where recognition of two species were accordant with HRM analysis, separation was based on the size of the amplified fragment. Using the designed primers and performing the assay, we confirmed this method to be much faster and have lower cost with more than 99% accuracy compared to methods such as RFLP.

CONCLUSION

The present study showed that this technique, which scans gene segments and creates an analysis pattern for detection of clinical samples, is useful and more dominant compared with PCR-RFLP. Thus, this method can be used for brucellosis detection, and clinical and epidemiological research.

Biological Risks and Laboratory-Acquired Infections: A Reality That Cannot be Ignored in Health Biotechnology

Advances and research in biotechnology have applications over a wide range of areas, such as microbiology, medicine, the food industry, agriculture, genetically modified organisms, and nanotechnology, among others. However, research with pathogenic agents, such as virus, parasites, fungi, rickettsia, bacterial microorganisms, or genetic modified organisms, has generated concern because of their potential biological risk - not only for people, but also for the environment due to their unpredictable behavior. In addition, concern for biosafety is associated with the emergence of new diseases or re-emergence of diseases that were already under control. Biotechnology laboratories require biosafety measures designed to protect their staff, the population, and the environment, which may be exposed to hazardous organisms and materials. Laboratory staff training and education is essential, not only to acquire a good understanding about the direct handling of hazardous biological agents but also knowledge of the epidemiology, pathogenicity, and human susceptibility to the biological materials used in research. Biological risk can be reduced and controlled by the correct application of internationally recognized procedures such as proper microbiological techniques, proper containment apparatus, adequate facilities, protective barriers, and special training and education of laboratory workers. To avoid occupational infections, knowledge about standardized microbiological procedures and techniques and the use of containment devices, facilities, and protective barriers is necessary. Training and education about the epidemiology, pathogenicity, and biohazards of the microorganisms involved may prevent or decrease the risk. In this way, the scientific community may benefit from the lessons learned in the past to anticipate future problems.

Prevalence of Brucella antibodies on a previously acute brucellosis infected population: sensitivity, specificity and predictive values of Rose Bengal and Wright standard tube agglutination tests

PURPOSE

Brucellosis is a zoonosis with worldwide distribution. The presence of antibodies after acute infection and the prevalence of positive serology in endemic area are not well documented.

METHODS

Patients hospitalized with acute brucellosis were relocated 3-13 years after the initial infection. Hospital records of the initial infection were retrieved, and examination of Brucella antibodies using Rose Bengal test (RBT) and Wright standard tube agglutination (STA) test was performed.

RESULTS

Eighty-three patients were hospitalized from 2000 to 2010; 50.6 % were farmers and 37.4 % livestock farmers. All had febrile illness and various focal complications. All had positive serology, and 82.2 % had positive blood cultures; 91.5 % were treated with streptomycin plus doxycycline. Seventy-two (86.7 %) were relocated on follow-up. Nine (12.5 %) had positive RBT and STA up to 1/320. Occupational history was associated with positive serology (p = 0.0172), and 8/9 of the positive individuals were livestock farmers (38.0 % of the livestock farmers checked). Residence, years after the infection, clinical presentation of brucellosis and treatment were not associated with serology results. Both tests had excellent sensitivity (nearly 100 %), specificity 87.5 % and excellent negative predictive value (nearly 100 %); however, positive predictive value was only 11.4 %.

CONCLUSIONS

Rapid and low-cost tests as RBT and STA are still very useful in diagnosing acute brucellosis; however, every positive test must be examined together with clinical symptoms and occupational history. The tests can be used as screening tests in endemic populations to rule out acute brucellosis.

Hospital-associated transmission of Brucella melitensis outside the laboratory

Brucella melitensis was identified in an aspirate obtained from a patient's hip joint during a procedure at a hospital in Canada. We conducted an investigation into possible exposures among hospital workers; 1 worker who assisted with the procedure tested positive for B. melitensis. Aerosol-generating procedures performed outside the laboratory may facilitate transmission of this bacterium.

Comparison between antibiotic therapy of Brucellosis with and without vitamin A

BACKGROUND

Brucellosis is one of the endemic diseases in our country and it can be in the types of acute, sub-acute or chronic. It estimates that about 20% of Brucellosis may change from acute to chronic. Because cell mediated immunity (CMI) is the main defense of body against Brucella species, it seems that some degree of Immunologic disorders existed in the patients with chronic form of diseases and some supplements such as Vitamin A (Vit A) as an immunomodulator can stimulate CMI and may decrease the rate of chronicity.

MATERIALS AND METHODS

In a single-blind randomized clinical trial 120 patients with the clinical and serological diagnosed Brucellosis were randomized. A total of 60 patients received streptomycin and Doxycycline as standard therapy for 6 weeks and others in addition to this Regimen received Vit A for about 4 weeks.

RESULTS

In the case group, only 1 case (1.6%) relapsed and in the control group 8 (13.5%) with significant difference (P < 0.005) between two groups. Morbidity of disease was different between two groups.

CONCLUSION

Vit A therapy in the patients with Brucellosis with may reduce the disease morbidity and rate of chronicity.

Risk factors for occupational brucellosis among veterinary personnel in Turkey

Veterinarians and veterinary technicians are at risk for occupational brucellosis. We described the risk factors of occupational brucellosis among veterinary personnel in Turkey. A multicenter retrospective survey was performed among veterinary personnel who were actively working in the field. Of 712 veterinary personnel, 84 (11.8%) had occupational brucellosis. The median number of years since graduation was 7 (interquartile ranges [IQR], 4-11) years in the occupational brucellosis group, whereas this number was 9 (IQR, 4-16) years in the non-brucellosis group (p<0.001). In multivariable analysis, working in the private sector (odds ratio [OR], 2.8; 95% confidence interval [95% CI], 1.55-5.28, p=0.001), being male (OR, 4.5; 95% CI, 1.05-18.84, p=0.041), number of performed deliveries (OR, 1.01; 95% CI, 1.002-1.02, p=0.014), and injury during Brucella vaccine administration (OR, 5.4; 95% CI, 3.16-9.3, p<0.001) were found to be risk factors for occupational brucellosis. We suggest that all veterinary personnel should be trained on brucellosis and the importance of using personal protective equipment in order to avoid this infection.

Brucella melitensis sternal osteomyelitis following median sternotomy

Human brucellosis, a zoonotic infection, may present with a range of symptoms but is rarely described as a cause of surgical site infections. We present the first reported case of Brucella melitensis causing sternal osteomyelitis of a midline sternotomy for a coronary artery bypass graft. The operation was performed in a non-endemic country but the patient had travelled to Syria immediately before surgery, where the infection was assumed to have been acquired. The infection resolved following treatment with doxycycline, rifampicin and gentamicin. We review the literature for surgical site infections related to Brucella species and discuss the infection control implications. Human brucellosis has the potential to cause surgical site infections and it should be in the differential diagnosis of any patient with a relevant exposure history presenting with a febrile illness and musculoskeletal findings.

Retrospective and prospective perspectives on zoonotic brucellosis

Members of the genus Brucella are pathogenic bacteria exceedingly well adapted to their hosts. The bacterium is transmitted by direct contact within the same host species or accidentally to secondary hosts, such as humans. Human brucellosis is strongly linked to the management of domesticated animals and ingestion of their products. Since the domestication of ungulates and dogs in the Fertile Crescent and Asia in 12000 and 33000 ya, respectively, a steady supply of well adapted emergent Brucella pathogens causing zoonotic disease has been provided. Likewise, anthropogenic modification of wild life may have also impacted host susceptibility and Brucella selection. Domestication and human influence on wild life animals are not neutral phenomena. Consequently, Brucella organisms have followed their hosts’ fate and have been selected under conditions that favor high transmission rate. The “arm race” between Brucella and their preferred hosts has been driven by genetic adaptation of the bacterium confronted with the evolving immune defenses of the host. Management conditions, such as clustering, selection, culling, and vaccination of Brucella preferred hosts have profound influences in the outcome of brucellosis and in the selection of Brucella organisms. Countries that have controlled brucellosis systematically used reliable smooth live vaccines, consistent immunization protocols, adequate diagnostic tests, broad vaccination coverage and sustained removal of the infected animals. To ignore and misuse tools and strategies already available for the control of brucellosis may promote the emergence of new Brucella variants. The unrestricted use of low-efficacy vaccines may promote a “false sense of security” and works towards selection of Brucella with higher virulence and transmission potential.

Outbreak of laboratory-acquired Brucella abortus in Brazil: a case report

Human brucellosis is an occupational disease affecting workers in slaughterhouses, butcher shops and the milk and dairy product industry as well as individuals who work in clinical or research laboratories. We report the first outbreak of a Brucella abortus infection in a Brazilian laboratory and compare the data obtained with reports available in the literature. Exposure was a result of damage to a biological safety cabinet and failure of the unidirectional airflow ventilation system. An epidemiological investigation identified 3 seroconverted individuals, 1 of whom had clinical manifestations and laboratory results compatible with infection at the time of exposure (n=11; attack rate=9.1%).

Aerosol-induced brucellosis increases TLR-2 expression and increased complexity in the microanatomy of astroglia in rhesus macaques

Brucella melitensis, a bacterial pathogen and agent of epizootic abortion causes multiple pathologies in humans as well as a number of agriculturally important animal species. Clinical human brucellosis manifests as a non-specific, chronic debilitating disease characterized by undulant fever, arthropathies, cardiomyopathies and neurological sequelae. These symptoms can occur acutely for a few weeks or persist for months to years. Within the brain, endothelial and glial cells can be infected leading to downstream activation events including matrix metalloprotease (MMP) and cytokine secretion and Toll-like receptor (TLR) signaling. These events are likely to lead to tissue remodeling, including morphologic changes in neuronal and glial cells, which are linked to neurological complications including depressive behavior, immune activation and memory loss. Our hypothesis was that B. melitensis infection and neurobrucellosis would lead to activation of astrocytes through upregulation of TLR2 and stimulate concurrent changes in the microanatomy. All six animals were infected via inhalation route. TLR2 expression was approximately doubled in white matter astrocytes of infected rhesus macaques. There was also a 50% increase in the number of astrocytes per unit area in subcortical white matter tracts suggesting increased innate immune activation. This coincided with dramatic increases in the length and complexity of the cell arbor of hypertrophic astrocytes in both cortical gray and white matter. Thus, aerosol-induced brucellosis results in dramatically increased innate immune activation of astrocytes in the absence of widespread neuroinflammation.

Key role of Toll-like receptor 2 in the inflammatory response and major histocompatibility complex class ii downregulation in Brucella abortus-infected alveolar macrophages

Alveolar macrophages (AM) seem to constitute the main cellular target of inhaled brucellae. Here, we show that Brucella abortus invades and replicates in murine AM without inducing cytotoxicity. B. abortus infection induced a statistically significant increase of tumor necrosis factor alpha (TNF-α), CXCL1 or keratinocyte chemoattractant (KC), interleukin-1β (IL-1β), IL-6, and IL-12 in AM from C57BL/6 mice and BALB/c mice, but these responses were generally weaker and/or delayed compared to those elicited in peritoneal macrophages. Studies using knockout mice for TLR2, TLR4, and TLR9 revealed that TNF-α and KC responses were mediated by TLR2 recognition. Brucella infection reduced in a multiplicity of infection-dependent manner the expression of major histocompatibility complex class II (MHC-II) molecules induced by gamma interferon (IFN-γ) in AM. The same phenomenon was induced by incubation with heat-killed B. abortus (HKBA) or the lipidated form of the 19-kDa outer membrane protein of Brucella (L-Omp19), and it was shown to be mediated by TLR2 recognition. In contrast, no significant downregulation of MHC-II was induced by either unlipidated Omp19 or Brucella LPS. In a functional assay, treatment of AM with either L-Omp19 or HKBA reduced the MHC-II-restricted presentation of OVA peptides to specific T cells. One week after intratracheal infection, viable B. abortus was detected in AM from both wild-type and TLR2 KO mice, but CFU counts were higher in the latter. These results suggest that B. abortus survives in AM after inhalatory infection in spite of a certain degree of immune control exerted by the TLR2-mediated inflammatory response. Both the modest nature of the latter and the modulation of MHC-II expression by the bacterium may contribute to such survival.

Ex vivo innate immune cytokine signature of enhanced risk of relapsing brucellosis

Background

Brucellosis, a zoonotic infection caused by one of the Gram-negative intracellular bacteria of the Brucella genus, is an ongoing public health problem in Perú. While most patients who receive standard antibiotic treatment recover, 5–40% suffer a brucellosis relapse. In this study, we examined the ex vivo immune cytokine profiles of recovered patients with a history of acute and relapsing brucellosis.

Methodology/Principal Findings

Blood was taken from healthy control donors, patients with a history of acute brucellosis, or patients with a history of relapsing brucellosis. Peripheral blood mononuclear cells were isolated and remained in culture without stimulation or were stimulated with a panel of toll-like receptor agonists or heat-killed Brucella melitensis (HKBM) isolates. Innate immune cytokine gene expression and protein secretion were measured by quantitative real-time polymerase chain reaction and a multiplex bead-based immunoassay, respectively.

Acute and relapse patients demonstrated consistently elevated cytokine gene expression and secretion levels compared to controls. Notably, these include: basal and stimulus-induced expression of GM-CSF, TNF-α, and IFN-γ in response to LPS and HKBM; basal secretion of IL-6, IL-8, and TNF-α; and HKBM or Rev1-induced secretion of IL-1β, IL-2, GM-CSF, IFN-Υ, and TNF-α. Although acute and relapse patients were largely indistinguishable by their cytokine gene expression profiles, we identified a robust cytokine secretion signature that accurately discriminates acute from relapse patients. This signature consists of basal IL-6 secretion, IL-1β, IL-2, and TNF-α secretion in response to LPS and HKBM, and IFN-γ secretion in response to HKBM.

Conclusions/Significance

This work demonstrates that informative cytokine variations in brucellosis patients can be detected using an ex vivo assay system and used to identify patients with differing infection histories. Targeted diagnosis of this signature may allow for better follow-up care of brucellosis patients through improved identification of patients at risk for relapse.

Brucellosis is a disease caused by transmission of bacteria of the Brucella genus from infected animals to humans. The main route of infection occurs through consumption of contaminated dairy products or contact with infected animals. While most patients treated with antibiotics will be cured of the infection, between 5–40% of patients experience a relapse of brucellosis. The mechanisms underlying these recurring infections remain poorly understood. In this study, we examined blood cells from control donors, patients who previously had acute infections, and patients who previously had relapsing infections. We identified an inflammatory cytokine signature from measurements of unstimulated and stimulated cells that showed statistically significant differences between relapsing and non-relapsing brucellosis patients. Future applications of this assay system may allow for better follow-up care of brucellosis through the diagnosis of this cytokine signature and predictive or improved identification of patients at risk for relapse.

Interlaboratory comparison of intact-cell matrix-assisted laser desorption ionization-time of flight mass spectrometry results for identification and differentiation of Brucella spp

Classical microbiological diagnosis of human brucellosis is time-consuming, hazardous, and subject to variable interpretation. Intact-cell matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) was evaluated for the routine identification of Brucella spp. Analysis of mass peak patterns allowed accurate identification to the genus level. However, statistical models based on peak intensities were needed for definite species differentiation. Interlaboratory comparison confirmed the reproducibility of the results.

A literature review of laboratory-acquired brucellosis

Brucellosis is a bacterial zoonotic disease which has been associated with laboratory-acquired infections. No recent reviews have addressed the characteristics of laboratory-acquired brucellosis (LAB). English-language literature was reviewed to identify reports of laboratory exposures to Brucella spp. and LAB cases between 1982 and 2007. Evaluation of 28 case reports identified 167 potentially exposed laboratory workers, of whom 71 had LAB. Nine reports were identified that summarized an additional 186 cases of LAB. Only 18 (11%) exposures were due to laboratory accidents, 147 (88%) exposures were due to aerosolization of organisms during routine identification activities, and the circumstances of 2 (1%) exposures were unknown. Brucella melitensis was the causative agent in 80% (135/167) of the exposures. Workers with high-risk exposures were 9.3 times more likely to develop LAB than workers with low-risk exposures (95% confidence interval [CI], 3.0 to 38.6; P < 0.0001); they were also 0.009 times likelier to develop LAB if they took antimicrobial PEP than if they did not (95% CI, 0 to 0.042; P < 0.0001). The median incubation period in case and summary reports was 8 weeks (range 1 to 40 weeks). Antimicrobial PEP is effective in preventing LAB. The incubation period may be used to identify appropriate serological and symptom surveillance time frames for exposed laboratory workers.

Hydrophobic gentamicin-loaded nanoparticles are effective against Brucella melitensis infection in mice

The clinical management of human brucellosis is still challenging and demands in vitro active antibiotics capable of targeting the pathogen-harboring intracellular compartments. A sustained release of the antibiotic at the site of infection would make it possible to reduce the number of required doses and thus the treatment-associated toxicity. In this study, a hydrophobically modified gentamicin, gentamicin-AOT [AOT is bis(2-ethylhexyl) sulfosuccinate sodium salt], was either microstructured or encapsulated in poly(lactic-co-glycolic acid) (PLGA) nanoparticles. The efficacy of the formulations developed was studied both in vitro and in vivo. Gentamicin formulations reduced Brucella infection in experimentally infected THP-1 monocytes (>2-log10 unit reduction) when using clinically relevant concentrations (18 mg/liter). Moreover, in vivo studies demonstrated that gentamicin-AOT-loaded nanoparticles efficiently targeted the drug both to the liver and the spleen and maintained an antibiotic therapeutic concentration for up to 4 days in both organs. This resulted in an improved efficacy of the antibiotic in experimentally infected mice. Thus, while 14 doses of free gentamicin did not alter the course of the infection, only 4 doses of gentamicin-AOT-loaded nanoparticles reduced the splenic infection by 3.23 logs and eliminated it from 50% of the infected mice with no evidence of adverse toxic effects. These results strongly suggest that PLGA nanoparticles containing chemically modified hydrophobic gentamicin may be a promising alternative for the treatment of human brucellosis.