Brucella Melitensis Infection Research Articles

Evaluation of Duration of Immunogenicity and Protective Efficacy of Improved Influenza Viral Vector-Based Brucella abortus Vaccine Against Brucella melitensis Infection in Sheep and Goats.

In this study, we first evaluated the duration of a protective immune response against Brucella melitensis infection in non-pregnant sheep and goats immunized with an improved (by vaccine formulation and route of administration) commercial Brucella abortus vaccine based on influenza viral vectors expressing Brucella immunodominant Omp16, L7/L12, Omp19, or Cu-Zn superoxide dismutase (SOD) proteins (Flu-BA_Omp19-SOD). Sheep and goats in the vaccinated group were immunized thrice concurrently via the subcutaneous and conjunctival routes of administration at an interval of 21 days. Animals in the control group were administered with 20% Montanide Gel01 adjuvant in phosphate-buffered saline in the same way. We showed that the Flu-BA_Omp19-SOD vaccine in sheep and goats induces antigen-specific Th1-biased [immunoglobulin G2a (IgG2a) over IgG1] antibody response and T-cell and interferon γ responses lasting over a period of 1 month post–last vaccination (PLV). The levels of protection against B. melitensis 16M infection (vaccination efficacy) in vaccinated sheep for a period of 6 months were 0–20% and in goats 20–40% compared to control challenge group. But the severity of B. melitensis 16M infection in the Flu-BA_Omp19-SOD–vaccinated sheep and goats during the entire period of observation revealed the infection index (P = 0.001–P < 0.0001) and Brucella colonization in lymph nodes and organs (P = 0.04–P < 0.0001) were significantly lower than those in the control group. To conclude, the Flu-BA_Omp19-SOD vaccine using improved formulation and administration method in sheep and goats provides augmented antigen specific humoral and T-cell immune response lasting only for 1 month PLV and partial protection for 6 months against B. melitensis 16M infection.

Mannosylated chitosan nanoparticles loaded with FliC antigen as a novel vaccine candidate against Brucella melitensis and Brucella abortus infection

Brucellosis is a worldwide bacterial zoonosis disease. Live attenuated Brucella vaccines have several drawbacks. Thus development of a safe and effective vaccine for brucellosis is a concern of many scientists. FliC protein contributes in virulence of Brucella; hence, it is a promising target for brucellosis vaccine. In this study, Mannosylated Chitosan Nanoparticles (MCN) loaded with FliC protein were synthesized as a targeted vaccine delivery system. The immunogenicity and protective efficacy of FliC and FliC-MCN against Brucella infection were evaluated in BALB/c mice. After cloning, expression and purification, FliC protein was loaded on MCN. The particle size, loading efficiency and in vitro release of the NPs were determined. Our investigation revealed that FliC and FliC-MCN could significantly increase specific IgG response (higher IgG2a titers). Besides, spleen cells from immunized mice produced high level of IFN-γ and IL-2 and low level IL-10 cytokines. Immunization with FliC and FliC-MCN conferred significant degree of protection against B. melitensis 16 M and B. abortus 544 infections. Overall these results indicate that FliC protein would be a novel potential antigen candidate for the development of a subunit vaccine against B. melitensis and B. abortus. Moreover, MCN could be used as an adjuvant and targeted vaccine delivery system.

Molecular epidemiological study on a human patient of Brucella melitensis infection occurred in Korea

Molecular epidemiological study on a human patient of Brucella melitensis infection occurred in Korea

Tulathromycin treatment does not affect bacterial dissemination or clearance of Brucella melitensis 16M following experimental infection of goats.

Brucellosis in sheep and goats, a zoonotic disease primarily associated with Brucella melitensis infections, causes significant economic losses and public health concerns worldwide. Although control measures are effective, economic limitations and nomadic lifestyles may limit vaccination coverage, and test and removal policies may not be feasible. In this study, we evaluated the effects of therapy with a long acting antimicrobial tulathromycin on the pathogenesis of brucellosis. Thirty-five goats were randomly assigned for experimental infection with B. melitensis strain 16M while open or during mid-gestation. Approximately half of the animals in each group were then treated with tulathromycin and subsequently assessed for the development of humoral responses to infection, clinical presentation, and bacterial dissemination and colonization. All animals, regardless of treatment group were successfully challenged with B. melitensis 16M demonstrated by bacterial recovery from conjunctival swabs and development of positive antibody titers. In goats infected while open, no animals aborted and Brucella was recovered from only one animal in tulathromycin-treated and one animal from the untreated group. Tulathromycin treatment of pregnant goats did not prevent abortion nor did it reduce bacterial dissemination, colonization, or shedding. Our data suggests that treatment of goats in mid-gestation with tulathromycin at the labeled dose does not influence disease pathogenesis or tissue colonization after experimental B. melitensis challenge.

Resveratrol ameliorates pathophysiological changes associated with Brucella melitensis infection in dexamethasone-treated does

Brucellosis has been regarded as the most widespread zoonotic disease. Infected animals have always been the source of human infection. Studies on the influence of stress on the pathological dynamics of this zoonotic disease are uncommon. This study aimed at evaluating serological responses, oxidative status, and pathological derangements associated with Brucella melitensis infection in does treated with dexamethasone. Twelve does were divided into 4 groups designated A, B, C, and D with 3 animals each. Groups A and B were ocularly inoculated with 107 CFU of B. melitensis. From day 21 postinoculation (pi), dexamethasone was administered for 7 days at 2 mg/kg intramuscularly. Group A was further treated with resveratrol for 5 days from day 31 post-B. melitensis inoculation. Group C was inoculated with similar dose of B. melitensis ocularly while group D was inoculated normal saline. Blood samples were collected at regular intervals for PCR, serology, and oxidative stress analysis. The does were sacrificed at day 42 pi. Selected tissues were collected for immunohistochemistry and histopathological examination. Dexamethasone administration induced increase in molondialdehyde level, intensity of immunostaining, and pathological alterations while decreasing superoxide dismutase, and glutathione levels in group A compared to group B. Five-day treatment with resveratrol following dexamethasone administration was observed to significantly ameliorate pathological derangements compared to group A. While stress could exacerbate pathological alterations associated with B. melitensis infection, antioxidants are capable of mitigating the impact of stress associated diseases.

Evaluation of immunogenicity of novel multi-epitope subunit vaccines in combination with poly I:C against Brucella melitensis and Brucella abortus infection

Brucellosis is a worldwide zoonotic disease affecting domestic animals and humans. Due to several safety problems associated with live attenuated vaccines (Rev1 and RB51), it is necessary to produce an efficient and safer vaccine against Brucella. In this study, we evaluated efficacy of two novel multi-peptide vaccine candidates of FliC, 7α-HSDH, BhuA antigens with and without poly I:C adjuvant. Hence, humoral and cellular immune responses and protective efficacy were determined in immunized mice. Our investigation indicated that multi-epitope antigens showed a significant induction of Th1 immunity with high levels of specific IgG (especially the IgG2a), as well as IFN-γ and IL-2 compared to the control group. The addition of poly I:C to multi-epitope antigens improved the humoral and cellular immune responses. The multi-epitope antigens with and without poly I:C also provided cross protection against B. melitensis16M and B. abortus544 infections. The present study suggests that the novel multi-epitope vaccine candidates based on B cell, CD4+ and CD8+T-cell epitopes of FliC, 7α-HSDH, BhuA proteins would be potential vaccine candidate against B. melitensis and B. abortus infections. Furthermore, poly I:C could be considered as a strong Th1-inducing adjuvant in designing vaccine formulation against brucellosis.

HMGB1 release from trophoblasts contributes to inflammation during Brucella melitensis infection.

Brucella melitensis infection causes acute necrotizing inflammation in pregnant animals; however, the pathophysiological mechanisms leading to placentitis are unknown. Here, we demonstrate that high-mobility group box 1 (HMGB1) acts as a mediator of placenta inflammation in B.melitensis-infected pregnant mice model. HMGB1 levels were increased in trophoblasts or placental explant during B.melitensis infection. Inhibition of HMGB1 activity with neutralising antibody significantly reduced the secretion of inflammatory cytokines in B.melitensis-infected trophoblasts or placenta, whereas administration of recombinant HMGB1 (rHMGB1) increased the inflammatory response. Mechanistically, this decreased inflammatory response results from inhibition of HMGB1 activity, which cause the suppression of both mitogen-activated protein kinases and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation. Moreover, neutralising antibody to HMGB1 prevented B.melitensis infection-induced activation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase in trophoblasts. In contrast, in vitro stimulation of trophoblasts with rHMGB1 caused activation of NADPH oxidase and increased the production of ROS, which contributes to high bacterial burden within trophoblasts or placenta. In vivo, treatment with anti-HMGB1 antibody increases the number of Brucella survival within placenta in B.melitensis-infected pregnant mice but successfully reduced the severity of placentitis and abortion.

Route of Infection Strongly Impacts the Host-Pathogen Relationship.

Live attenuated vaccines play a key role in the control of many human and animal pathogens. Their rational development is usually helped by identification of the reservoir of infection, the lymphoid subpopulations associated with protective immunity as well as the virulence genes involved in pathogen persistence. Here, we compared the course of Brucella melitensis infection in C57BL/6 mice infected via intraperitoneal (i.p.), intranasal (i.n.) and intradermal (i.d.) route and demonstrated that the route of infection strongly impacts all of these parameters. Following i.p. and i.n. infection, most infected cells observed in the spleen or lung were F4/80+ myeloid cells. In striking contrast, infected Ly6G+ neutrophils and CD140a+ fibroblasts were also observed in the skin after i.d. infection. The virB operon encoding for the type IV secretion system is considered essential to deflecting vacuolar trafficking in phagocytic cells and allows Brucella to multiply and persist. Unexpectedly, the ΔvirB Brucella strain, which does not persist in the lung after i.n. infection, persists longer in skin tissues than the wild strain after i.d. infection. While the CD4+ T cell-mediated Th1 response is indispensable to controlling the Brucella challenge in the i.p. model, it is dispensable for the control of Brucella in the i.d. and i.n. models. Similarly, B cells are indispensable in the i.p. and i.d. models but dispensable in the i.n. model. γδ+ T cells appear able to compensate for the absence of αβ+ T cells in the i.d. model but not in the other models. Taken together, our results demonstrate the crucial importance of the route of infection for the host pathogen relationship.

Effects of resveratrol on shedding and pathological dynamics in experimental B. melitensis infection in dexamethasone-treated nonpregnant Boer goats

ABSTRACT Brucellosis constitutes an infectious re-emerging zoonosis. Spread of diseases could be exacerbated by stress-induced immunosuppression. This study evaluated relationship between Brucella melitensis infection, shedding dynamics, dexamethasone-induced stress, pathological alterations and resveratrol ameliorative effects in goats. Twelve nonpregnant goats were divided into four groups A, B, C, and D of three animals each. Groups A and B were administered 107 CFU/mL of B. melitensis ocularly, 21 days prior to 7 days consecutive administration of dexamethasone (2 mg/kg). Group A was further administered resveratrol (5 mg/kg) intravenously for 5 consecutive days from day 31 post B. melitensis inoculation. Group C was administered similar dose of B. melitensis while group D was inoculated normal saline. Blood, nasal, ocular, and vaginal swabs were collected at intervals for analysis. The does were sacrificed at day 42 post inoculation (pi). Tissues were collected for tissue bacterial load determination, histopathology, and immunohistochemistry. Dexamethasone administration from day 21 pi increased the frequency in the shedding dynamics, tissue bacterial load, pathological alterations (frequency of microgranuloma and intensity of immunostaining) in group B while 5 days treatment with resveratrol following dexamethasone administration significantly reduced tissue bacterial load, decline in shedding dynamics, and ameliorate damage by dexamethasone administration/B. melitensis infection.

Cardiac implantable electronic device infections: Observational data from a tertiary care center in Lebanon.

With increasing rates of device implantation, there is an increased recognition of device infection. We conducted a retrospective observational study in a tertiary care center in Lebanon, with data collected from medical records of patients presenting with cardiac implantable electronic device (CIED) infection from 2000 to 2017 with the purpose of identifying etiologies, risk factors and other parameters, and comparing them to available data from the rest of the world. We identified a total of 22 CIED infections. The most common microbial etiologies, including involvement in polymicrobial infection, were coagulase-negative staphylococci (45.5%) and Staphylococcus aureus (22.7%). Rare cases of Brucella melitensis, Sphingomonas paucimobilis, and Kytococcus schroeteri device infection were seen. Heart failure was seen in 77.3% of patients, hypertension in 68.2%, and chronic kidney disease in 50%. Skin changes were the most common presenting symptoms (86.4%). Antibiotics were given to all patients and all had their devices removed, with 36.4% undergoing new device implantation. This is the first study of CIED infections in Lebanon and the Middle East. Local epidemiology and occupational exposure must be considered while contemplating the microbial etiology of infection. Close monitoring after device implantation is important in preventing device infection that carries high risk of morbidity and mortality.

The Immunogenicity of OMP31 Peptides and Its Protection Against Brucella melitensis Infection in Mice

Given brucellosis is a widespread zoonosis in the world, a safe and effective vaccine is urgently needed. Recent trend in vaccine design has shifted to epitope-based vaccines that are safe and specific. In this study, peptide containing both T-cell and B-cell epitopes of OMP31 was synthesized and used to immunize the mice by nasal administration. The protective efficacy was evaluated. Mice immunized with the B epitope or TB epitope peptides of OMP31 had higher levels of IgG1 and IgG2a in the serum. While the BALB/c mice immunized with peptides containing T cell epitope or TB epitope of OMP31 showed high degree of IFN-γ-producing T cells in the lymphocytes from the respiratory draining lymph nodes and spleen. After intranasally challenged with 5 × 105 CFU of Brucella melitensis (strain 16 M), the bacterial loads in lung of the immunized mice were significantly lower than control group. These data demonstrate for the first time that peptides of OMP31 containing T epitope, B epitope or TB epitopes are of high immunogenicity and thus can protect host from Brucella melitensis infection in lung.

Nanotherapeutic provides dose sparing and improved antimicrobial activity against Brucella melitensis infections

New therapies are needed to treat chronic bacterial diseases and intracellular pathogens, in particular, are very difficult to manage. The use of nanotherapeutics represents an approach to exploit size and charge of biological membranes to overcome barriers for treatment of intracellular pathogens including Brucella melitensis. In this work, polyanhydride nanoparticles comprised of copolymers of sebacic acid, 1,6-bis(p-carboxyphenoxy)hexane, and 1,8-bis(p-carboxyphenoxy)-3,6-dioxaoctane were synthesized to encapsulate antimicrobial compounds doxycycline and rifampicin. The nanoparticles demonstrated sustained release of rifampicin for a week with the antimicrobial activity peaking at 72 h and lasting up to a week. Treatment of B. melitensis infected macrophages with rifampicin-containing nanoparticles rapidly eliminated viable intracellular bacteria following 48 h of treatment and pretreatment with the nano-formulations prevented intracellular infection in contrast to soluble drug controls. Treatment of infected BALB/c mice with a nanoparticle cocktail containing doxycycline and rifampicin for five days decreased bacterial burden by three log10 in the liver. Extended release of antibiotics was demonstrated in vivo by treating B. melitensis infected mice with the standard therapy of daily 0.5 mg doxycycline dose or single 0.5 mg doxycycline-encapsulated nanoparticles delivered once a week. After 3 weeks, bacterial counts in spleen and liver were statistically equal between animals treated with the weekly nano-formulation and daily soluble drug, representing a seven-fold dose sparing. Altogether, these results demonstrated that the use of nanotherapeutics was successful at increasing antimicrobial efficacy and improving in vivo activity through a combination of intracellular delivery, dose sparing, and extended release in treating chronic bacterial infections. This platform technology can also provide benefits for drug delivery against other chronic intracellular bacterial pathogens, including Mycobacterium and Burkholderia species, including treatments against antibiotic-resistant infections.

Preparation and Evaluation of Rifampicin and Co-trimoxazole-loaded Nanocarrier against Brucella melitensis Infection

Brucellosis or Malta fever is a contagious infection common between human and domestic animals. Many antibiotics are used for brucellosis treatment, but they are not efficient and put heavy burden on society. Co-trimoxazole and rifampicin are two candidates for brucellosis treatment. In this study, we aimed to enhance the efficacy of these antibiotics using designed nanoparticles.Different concentrations of co-trimoxazole and rifampicin were used for loading onto a nanostructure of synthesized monomethoxy poly(ethylene glycol)-oleate (mPEG-OA). The solubility, cytotoxicity, and efficacy of these nano-packed antibiotics on Brucella-infected murine phagocytic cells were examined, as compared with free antibiotics. Then the release nanoparticles was increased approximately 3.5 and 1.5fold, respectively, which is considerable in comparison with free insoluble ones.Despite acceptable loading percentage, the application of co-trimoxazole-loaded nanoparticle on Brucella-infected J774A.1 murine macrophage-like cells did not lead to reduction in the number of bacteria; however, the efficacy of rifampicin on Brucella-infected murine phagocytic cells enhanced.In the current study, the efficacy of rifampicin on reducing the number of Brucella melitensis increased by the novel synthesized nanostructure. In contrast, since co-trimoxazole efficacy did not enhance by loading onto nanoparticles, the co-trimoxazole inefficiency is most likely not due to its low penetration or insolubility, and probably there are other factors that remain to be clarified in the future investigations.

High Shedding Potential and Significant Individual Heterogeneity in Naturally-Infected Alpine ibex (Capra ibex) With Brucella melitensis.

Wildlife reservoirs of infectious diseases raise major management issues. In Europe, brucellosis has been eradicated in domestic ruminants from most countries and wild ruminants have not been considered important reservoirs so far. However, a high prevalence of Brucella melitensis infection has been recently identified in a French population of Alpine ibex (Capra ibex), after the emergence of brucellosis was confirmed in a dairy cattle farm and two human cases. This situation raised the need to identify the factors driving the persistence of Brucella infection at high prevalence levels in this ibex population. In the present paper, we studied the shedding pattern of B. melitensis in ibex from Bargy Massif, French Alps. Bacteriological examinations (1–15 tissues/samples per individual) were performed on 88 seropositive, supposedly infected and euthanized individuals. Among them, 51 (58%) showed at least one positive culture, including 45 ibex with at least one Brucella isolation from a urogenital sample or a lymph node in the pelvic area (active infection in organs in the pelvic area). Among these 45 ibex, 26 (30% of the total number of necropsied animals) showed at least one positive culture for a urogenital organ and were considered as being at risk of shedding the bacteria at the time of capture. We observed significant heterogeneity between sex-and-age classes: seropositive females were most at risk to excrete Brucella before the age of 5 years, possibly corresponding to abortion during the first pregnancy following infection such as reported in the domestic ruminants. The high shedding potential observed in young females may have contributed to the self-sustained maintenance of infection in this population, whereas males are supposed to play a role of transmission between spatial units through venereal transmission during mating. This heterogeneity in the shedding potential of seropositive individuals should be considered in the future to better evaluate management scenarios in this system as well as in others.

Anti-Brucella activity of Caryopteris mongolica Bunge root extract against Brucella melitensis infection in mice

BackgroundThe current treatment for human brucellosis requires a combination of antibiotics for long periods of time, and the reported incidence and prevalence of the disease vary widely in nomadic livestock of Mongolia. The objective of the present study was to evaluate the in vivo antibacterial activity of the C. mongolica root extract against B. melitensis.MethodsIn this study, we used of 6 groups of mice (n = 5). Five groups of BALB/c mice were inoculated intraperitoneally with the M16 strain of B. melintensis, as follows: (i) one group was used for pretreatment monitoring; (ii) the control group was administered 2% Tween 80 and was used as the non-treatment group; and the other three groups were treated with one oral gavage per day for 21 days with (iii) doxycycline (2 mg/day), (iv) doxycycline (1 mg/day) with root extract (20 mg/day), and (v) C. mongolica root extract (20 mg/day). The one group that was kept non-infected was used as a healthy control group.ResultsThis study demonstrated that daily treatment with doxycycline alone and in combination with C. mongolica root extract significantly reduced splenic infection at the end of treatment. However, the spleen index of both the doxycycline-treated and the combination-treated groups of mice decreased by approximately 50% compared to that of the healthy control mouse group. Treatment with the C. mongolica root extract resulted in a 1.47log reduction in splenic infection compared to the non-treatment group, and the spleen index of the C. mongolica-treated group of mice was the same as that of the normal mouse group. In all treatment groups, neutrophil phagocytic activity significantly decreased, and all treatment groups demonstrated splenic regeneration.ConclusionsThe present study showed that the C. mongolica root extract may be useful in the treatment of brucellosis patients, in combination with doxycycline or other antibiotics, to reduce the toxicity of high-dosage antibiotics, to prevent the development of antibiotic resistance and to prevent Brucella infection.

Intraperitoneal immunization with Urease loaded N-trimethyl Chitosan nanoparticles elicits high protection against Brucella melitensis and Brucella abortus infections

Brucella (B) species are brucellosis causative agents, a worldwide zoonotic illness causing Malta fever in humans and abortion in domestic animals. In this work, we evaluated the vaccine potential of Trimethyl chitosan (TMC) nanoparticles formulation of Urease (TMC/Urease) against brucellosis. TMC/Urease nanoparticles and urease without any adjuvant were separately administered both orally and intraperitoneally. Intraperitoneal (i.p.) administration of urease alone as well as oral administration of both TMC/Urease nanoparticles and urease alone, elicited low titers of specific immunoglobulin G (IgG), while i.p. immunization with TMC/Urease nanoparticles induced high specific IgG production levels. As it was indicated by the cytokine assay and the antibody isotypes, i.p. immunization by urease alone, and TMC/Urease nanoparticles induced a mixed Th1-Th2 immune response, whereas oral administration of both urease alone and TMC/Urease nanoparticles induced a mixed Th1-Th17 immune response. In lymphocyte proliferation assay, spleen cells from i.p.-vaccinated mice with TMC/Urease nanoparticles showed a strong recall proliferative response. Vaccinated animals were challenged with virulent strains of B. melitensis and B. abortus. I.p. vaccination with TMC/Urease nanoparticles resulted in a high degree of protection. Altogether, our results indicated that TMC nanoparticles are a potent delivery system for i.p.-administered Brucella antigens.

Co-infection with Border Disease Virus and Brucella melitensis in an Aborted Sheep Foetus

In this study, we investigated the potential roles of BDV and Brucella melitensis infections in a case of sheep abortion. Internal organ specimens from aborted sheep foetus and EDTA whole blood sample from mother of the foetus were collected from a sheep flock in the Konya Province in the Central Anatolia region of Turkey in 2017. The presence of Brucella spp. directly assessed by bacterial isolation and detection of BDV was carried by real time RT-PCR. Genetic characterization of the BDV field isolate was conducted by sequencing the 5’- end untranslated region (UTR) region of BDV. Brucella strain was isolated from the samples of aborted sheep foetus, and it was identified as Brucella melitensis by biochemical characteristics, agglutination with monospecific A and M sera. BDV RNA was detected in EDTA whole blood sample and aborted sheep foetus. Phylogenetic analysis in 5’-UTR region allocated the field isolate of BDV obtained in this study into BDV-7 genotype. To the best of our knowledge, this is the first report on the dual infection of aborted sheep foetus with BDV and Brucella melitensis.

Dual Infection of Sheep Aborted Foetus with Peste des Petits Ruminants Virus and Brucella melitensis

In this study, we investigated the potential roles of Brucella melitensis and PPR virus (PPRV) infections in a case of sheep abortion. Samples were collected from PPR-suspected ewe and its aborted foetus from a sheep flock in the Antalya Province in the Mediterranean region of Turkey in 2016. The presence of Brucella spp. directly assessed by bacterial isolation and detection of PPRV was carried by real time RT-PCR. Genetic characterization of the PPRV field isolates was conducted by sequencing the fusion (F) gene of PPRV. Brucella strain was isolated from the samples of aborted sheep foetus, and it was identified as Brucella melitensis by biochemical characteristics, agglutination with monospecific A and M sera. PPRV RNA was detected in samples of PPR-suspected ewe and its foetus. Phylogenetic analysis showed that the field isolate of PPRV obtained in this study was clustered within lineage IV. To the best of our knowledge, this is the first report on the dual infection of aborted sheep foetus with PPRV and Brucella melitensis.

Clinical features and serum profile of inflammatory biomarkers in patients with brucellosis.

Brucellosis is a zoonosis caused by Brucella, a highly infectious Gram-negative coccobacillus that has been isolated from a variety of mammals. Brucella melitensis is considered the most common cause of human brucellosis. The aim of thisretrospectivestudy was to evaluate the diagnostic value of serum parameters that relate to Brucella melitensis infection. This investigation retrospectively analyzed the clinical laboratory tests and symptoms of brucellosis, which was confirmed by microbiological and serological methods. A total of 36 patients (31 males, 5 females; mean age 49.17 ± 13.56 years) admitted with brucellosis were included in the study over a three-year period between 2012 and 2015 in Peking University People's Hospital (PKUPH). A statistically significant increase was observed in C-reactive protein and erythrocyte sedimentation rate in patients with low titers of serum antibody when compared with those with high titers. No difference was observed between the two groups with respect to the other serum parameters such as procalcitonin or white blood cell count. Two blood culture systems also yielded different results. In this study, we demonstrated that culture can be improved by using multiple blood culture systems to isolate Brucella melitensis. We also found the different role of inflammatory markers play during the process of brucellosis. The present study may be a helpful reference in the diagnosis of brucellosis.

Preparation and Evaluation of Rifampicin and Co-trimoxazole-loaded Nanocarrier against Brucella melitensis Infection

Background:Brucellosis or Malta fever is a contagious infection common between human and domestic animals. Many antibiotics are used for brucellosis treatment, but they are not efficient and put heavy burden on society. Co-trimoxazole and rifampicin are two candidates for brucellosis treatment. In this study, we aimed to enhance the efficacy of these antibiotics using designed nanoparticles.Methods:Different concentrations of co-trimoxazole and rifampicin were used for loading onto a nanostructure of synthesized monomethoxy poly(ethylene glycol)-oleate (mPEG-OA). The solubility, cytotoxicity, and efficacy of these nano-packed antibiotics on Brucella-infected murine phagocytic cells were examined, as compared with free antibiotics. Then the release nanoparticles was increased approximately 3.5 and 1.5fold, respectively, which is considerable in comparison with free insoluble ones.Results:Despite acceptable loading percentage, the application of co-trimoxazole-loaded nanoparticle on Brucella-infected J774A.1 murine macrophage-like cells did not lead to reduction in the number of bacteria; however, the efficacy of rifampicin on Brucella-infected murine phagocytic cells enhanced.Conclusion:In the current study, the efficacy of rifampicin on reducing the number of Brucella melitensis increased by the novel synthesized nanostructure. In contrast, since co-trimoxazole efficacy did not enhance by loading onto nanoparticles, the co-trimoxazole inefficiency is most likely not due to its low penetration or insolubility, and probably there are other factors that remain to be clarified in the future investigations.