Díaz Aparicio, E
Brucellosis is a disease that causes severe economic losses for livestock farms worldwide. Brucella melitensis, B. abortus and B. suis, which are transmitted between animals both vertically and horizontally, cause abortion and infertility in their primary natural hosts - goats and sheep (B. melitensis), cows (B. abortus) and sows (B. suis). Brucella spp. infect not only their preferred hosts but also other domestic and wild animal species, which in turn can act as reservoirs of the disease for other animal species and humans. Brucellosis is therefore considered to be a major zoonosis transmitted by direct contact with animals and/or their secretions, or by consuming milk and dairy products.
Report This report presents the results of an investigation to evaluate Brucella suis persistence on five materials (typically found in the outdoor environment) under various environmental conditions and exposure durations.
Nan, Wenlong; Tan, Pengfei; Wang, Yong; Xu, Zouliang; Mao, Kairong; Peng, Daxin; Chen, Yiping
Immunisation with attenuated Brucella spp. vaccines prevents brucellosis, but may also interfere with diagnosis. In this study, a duplex PCR was developed to distinguish Brucella suis vaccine strain S2 from field strains of B. suis biovar 1 and other Brucella spp. The PCR detected 60 fg genomic DNA of B. suis S2 or biovar 1 field strains and was able to distinguish B. suis S2 and wild-type strains of B. suis biovar 1 among 76 field isolates representing all the common species and biovars, as well as four vaccine strains, of Brucella.
Hänsel, C.; Mertens, K.; Elschner, M. C.; Melzer, F.
Introduction Brucella suis is the causative agent of brucellosis in suidae and is differentiated into five biovars (bv). Biovars 1 and 3 possess zoonotic potential and can infect humans, whereas biovar 2 represents the main source of brucellosis in feral and domestic pigs in Europe. Both aspects, the zoonotic threat and the economic loss, emphasize the necessity to monitor feral and domestic pig populations. Available serological or PCR based methods lack sensitivity and specificity. Results Here a bioinformatics approach was used to identify a B. suis specific 17 bp repeat on chromosome II (BS1330_II0657 locus). This repeat is common for B. suis bv 1 to 4 and was used to develop a TaqMan probe assay. The average PCR efficiency was determined as 95% and the limit of detection as 12,5 fg/µl of DNA, equally to 3.7 bacterial genomes. This assay has the highest sensitivity of all previously described B. suis specific PCR assays, making it possible to detect 3-4 bacterial genomes per 1 µl of sample. The assay was tested 100% specific for B. suis and negative for other Brucella spp. and closely related non-Brucella species. Conclusions This novel qPCR assay could become a rapid, inexpensive and reliable screening method for large sample pools of B. suis 1 to 4. This method will be applicable for field samples after validation. PMID:26392898
Kin, Marta S; Fort, Marcelo; de Echaide, Susana T; Casanave, Emma B
Brucellosis is a zoonotic disease transmitted from an animal reservoir to humans. Both, wildlife and domestic animals, contribute to the spreading of these zoonosis. The surveillance of the animal health status is strictly regulated for domestic animals, whereas disease monitoring in wildlife does not exist. The aim of the present study was to provide data on the prevalence of anti-Brucella antibodies in Chaetophractus villosus from a region of La Pampa, Argentina to assess public health risks. The C. villosus is endemic to South America, and in Argentina it represents a food resource for human consumption. A total of 150 sera of armadillos bleeding between 2007 and 2010 were tested using buffered plate antigen test (BPAT), serum agglutination test (SAT), 2-mercaptoethanol (2-ME) and complement fixation test (CFT), for the detection of anti-Brucella antibodies. Antibodies to Brucella sp. were found in 16% (24:150) of the armadillos tested using the BPAT test. All 24 positive samples were confirmed by the SAT, 2-ME and CFT tests. Strain isolation was attempted from liver and spleen samples of two animals with positive serology. Isolates were characterized by conventional biotyping and identification of specific DNA using polymerase chain reaction (PCR). A total of 2 isolates were recovered from spleen and liver. Both of them were identified as Brucella suis biovar 1. This preliminary study provides the first report on the seroprevalence of brucellosis and describes the first isolate of B. suis biovar 1 in C. villosus in Argentina.
Bricker, B J; Halling, S M
Several PCR assays which identify the genus Brucella but do not discriminate among species have been reported. We describe a PCR assay that comprises five oligonucleotide primers which can identify selected biovars of four species of Brucella. Individual biovars within a species are not differentiated. The assay can identify three biovars (1, 2, and 4) of B. abortus, all three biovars of B. melitensis, biovar 1 of B. suis, and all B. ovis biovars. These biovars include all of the Brucella species typically isolated from cattle in the United States, a goal of the present research. The assay exploits the polymorphism arising from species-specific localization of the genetic element IS711 in the Brucella chromosome. Identity is determined by the size(s) of the product(s) amplified from primers hybridizing at various distances from the element. The performance of the assay with U.S. field isolates was highly effective. When 107 field isolates were screened by the described method, there was 100% agreement with the identifications made by conventional methods. Six closely related bacteria (Agrobacterium radiobacter, Agrobacterium rhizogenes, Ochrobactrum anthropi, Rhizobium leguminosarum, Rhizobium meliloti, and Rhodospirillum rubrum) and two control bacteria (Bordetella bronchiseptica and Escherichia coli) tested negative by the assay. Images PMID:7852552
Zhu, Liangquan; Feng, Yu; Zhang, Ge; Jiang, Hui; Zhang, Zhen; Wang, Nan; Ding, Jiabo; Suo, Xun
Brucellosis is a wide spread zoonotic disease that causes abortion and infertility in mammals and leads to debilitating, febrile illness in humans. Brucella abortus, Brucella melitensis and Brucella suis are the major pathogenic species to humans. Vaccination with live attenuated B. suis strain 2 (S2) vaccine is an essential and critical component in the control of brucellosis in China. The S2 vaccine is very effective in preventing brucellosis in goats, sheep, cattle and swine. However, there are still debates outside of China whether the S2 vaccine is able to provide protection against heterologous virulent Brucella species. We investigated the residual virulence, immunogenicity and protective efficacy of the S2 vaccine in BALB/c mice by determining bacteria persistence in spleen, serum antibody response, cellular immune response and protection against a heterologous virulent challenge. The S2 vaccine was of low virulence as there were no bacteria recovered in spleen four weeks post vaccination. The vaccinated mice developed Brucella-specific IgG in 2-3 weeks, and a burst production of IFN-γ at one week as well as a two-fold increase in TNF-α production. The S2 vaccine protected mice from a virulent challenge by B. melitensis M28, B. abortus 2308 and B. suis S1330, and the S2 vaccinated mice did not develop any clinical signs or tissue damage. Our study demonstrated that the S2 vaccine is of low virulence, stimulates good humoral and cellular immunity and protects animals against infection by heterologous, virulent Brucella species.
Wang, Jing-Yu; Wu, Ning; Liu, Wan-Hua; Ren, Juan-Juan; Tang, Pan; Qiu, Yuan-Hao; Wang, Chi-Young; Chang, Ching-Dong; Liu, Hung-Jen
The commonest ways of diagnosing brucellosis in animals include the Rose-Bengal plate agglutination test, the buffered plate agglutination test (BPA), the slide agglutination test, the complement fixation test, and the indirect enzyme linked immunosorbent assay (I-ELISA). However, these methods cannot discriminate the Brucella vaccine strain (Brucella suis strain 2; B. suis S2) from naturally acquired virulent strains. Of the six common Brucella species, Brucella melitensis, Brucella abortus, and B. suis are the commonest species occurring in China. To develop an ELISA assay that can differentiate between cows inoculated with B. suis S2 and naturally infected with B. abortus and B. melitensis, genomic sequences from six Brucella spp. (B. melitensis, B. abortus, B. suis, Brucella canis, Brucella neotomae and Brucella ovis) were compared using Basic Local Alignment Search Tool software. One particular gene, the repA-related gene, was found to be a marker that can differentiate B. suis from B. abortus and B. melitensis. The repA-related gene of B. suis was PCR amplified and subcloned into the pET-32a vector. Expressed repA-related protein was purified and used as an antigen. The repA-based ELISA was optimized and used as specific tests. In the present study, serum from animals inoculated with the B. suis S2 vaccine strain had positive repA-based ELISA results. In contrast, the test-positive reference sera against B. abortus and B. melitensis had negative repA-based ELISA results. The concordance rate between B. abortus antibody-negative (based on the repA-based ELISA) and the Brucella gene-positive (based on the 'Bruce ladder' multiplex PCR) was 100%. Therefore, the findings suggest that the repA-based ELISA is a useful tool for differentiating cows vaccinated with the B. suis S2 and naturally infected with B. abortus and B. melitensis.
Contreras-Rodriguez, Araceli; Quiroz-Limon, Jose; Martins, Ana M; Peralta, Humberto; Avila-Calderon, Eric; Sriranganathan, Nammalwar; Boyle, Stephen M; Lopez-Merino, Ahide
Background The sequenced genomes of the Brucella spp. have two urease operons, ure-1 and ure-2, but there is evidence that only one is responsible for encoding an active urease. The present work describes the purification and the enzymatic and phylogenomic characterization of urease from Brucella suis strain 1330. Additionally, the urease reactivity of sera from patients diagnosed with brucellosis was examined. Results Urease encoded by the ure-1 operon of Brucella suis strain 1330 was purified to homogeneity using ion exchange and hydrophobic interaction chromatographies. The urease was purified 51-fold with a recovery of 12% of the enzyme activity and 0.24% of the total protein. The enzyme had an isoelectric point of 5, and showed optimal activity at pH 7.0 and 28–35°C. The purified enzyme exhibited a Michaelis-Menten saturation kinetics with a Km of 5.60 ± 0.69 mM. Hydroxyurea and thiourea are competitive inhibitors of the enzyme with Ki of 1.04 ± 0.31 mM and 26.12 ± 2.30 mM, respectively. Acetohydroxamic acid also inhibits the enzyme in a competitive way. The molecular weight estimated for the native enzyme was between 130–135 kDa by gel filtration chromatography and 157 ± 7 kDa using 5–10% polyacrylamide gradient non-denaturing gel. Only three subunits in SDS-PAGE were identified: two small subunits of 14,000 Da and 15,500 Da, and a major subunit of 66,000 Da. The amino terminal sequence of the purified large subunit corresponded to the predicted amino acid sequence encoded by ureC1. The UreC1 subunit was recognized by sera from patients with acute and chronic brucellosis. By phylogenetic and cluster structure analyses, ureC1 was related to the ureC typically present in the Rhizobiales; in contrast, the ureC2 encoded in the ure-2 operon is more related to distant species. Conclusion We have for the first time purified and characterized an active urease from B. suis. The enzyme was characterized at the kinetic, immunological and phylogenetic levels
Viana, Marcus Vinicius Canário; Govil Batra, Dhwani; Boisvert, Sébastien; Brettin, Thomas Scott; Frace, Michael; Xia, Fangfang; Azevedo, Vasco; Tiller, Rebekah; Hoffmaster, Alex R.
ABSTRACT Brucella suis is a Gram-negative, facultative intracellular pathogen that has pigs as its preferred host, but it can also infect humans. Here, we report the draft genome sequences of two B. suis strains that were isolated from the same patient, 8 years apart. PMID:28254974
Gross, Antoine; Terraza, Annie; Ouahrani-Bettache, Safia; Liautard, Jean-Pierre; Dornand, Jacques
During the complex interaction between an infectious agent and a host organism, the pathogen can interfere with the host cell's programmed death to its own benefit. Induction or prevention of host cell apoptosis appears to be a critical step for determining the infection outcome. Members of the gram-negative bacterial genus Brucella are intracellular pathogens which preferentially invade monocytic cells and develop within these cells. We investigated the effect of Brucella suis infection on apoptosis of human monocytic phagocytes. The present study provides evidence that Brucella infection inhibited spontaneously occurring apoptosis in human monocytes. Prevention of monocyte apoptosis was not mediated by Brucella lipopolysaccharide and required bacterial survival within infected cells. Both invaded and noninvaded cells were protected, indicating that soluble mediators released during infection were involved in the phenomenon. Analysis of Brucella-infected monocytes revealed specific overexpression of the A1 gene, a member of the bcl-2 family implicated in the survival of hematopoietic cells. Brucella infection also rendered macrophage-like cells resistant to Fas ligand- or gamma interferon-induced apoptosis, suggesting that Brucella infection protected host cells from several cytotoxic processes occurring at different steps of the immune response. The present data clearly show that Brucella suis modulated the monocyte/macrophage's apoptotic response to the advantage of the pathogen, thus preventing host cell elimination. This might represent a strategy for Brucella development in infected hosts. PMID:10603407
Wang, Yuanzhi; Wang, Zhen; Chen, Xin; Zhang, Hui; Guo, Fei; Zhang, Ke; Feng, Hanping; Gu, Wenyi; Wu, Changxin; Ma, Lei; Li, Tiansen; Chen, Chuangfu; Gao, Shan
Brucella species are the most important zoonotic pathogens worldwide and cause considerable harm to humans and animals. In this study, we presented the complete genome of B. suis 019 isolated from sheep (ovine) with epididymitis. B. suis 019 has a rough phenotype and can infect sheep, rhesus monkeys and possibly humans. The comparative genome analysis demonstrated that B. suis 019 is closest to the vaccine strain B. suis bv. 1 str. S2. Further analysis associated the rsh gene to the pathogenicity of B. suis 019, and the WbkA gene to the rough phenotype of B. suis 019. The 019 complete genome data was deposited in the GenBank database with ID PRJNA308608. PMID:26821047
Liu, Jun; Li, Yi; Sun, Yang; Ji, Xue; Zhu, Lingwei; Guo, Xuejun; Zhou, Wei; Zhou, Bo; Liu, Shuang; Zhang, Ruian; Feng, Shuzhang
With the purpose of generating Brucella suis bacterial ghosts and investigating the immunogenicity of bacterial ghosts as a vaccine candidate, the lysis gene E and temperature-sensitive regulator cassette were cloned into a shuttle plasmid, pBBR1MCS-2, for construction of a recombinant temperature-sensitive shuttle lysis plasmid, pBBR1MCS-E. pBBR1MCS-E was then introduced into attenuated B. suis live vaccine S2 bacteria, and the resultant transformants were used for production of B. suis ghosts (BSGs) by inducing lysis gene E expression. The BSGs were characterized by observing their morphology by transmission electron microscopy. The safety and immunogenicity of BSGs were further evaluated using a murine model, the result suggested that BSG was as safe as formalin-killed B. suis. In mice, BSG demonstrated a similar capacity of inducing pathogen-specific serum IgG antibody response, spleen CD3(+) and CD4(+) T cell responses, induce secretion of gamma interferon and interleukin-4, and protection levels against Brucella melitensis 16M challenge, as the attenuated B. suis live vaccine. These data suggesting that BSG could confer protection against Brucella infection in a mouse model of disease and may be developed as a new vaccine candidate against Brucella infection.
Naroeni, Aroem; Jouy, Nicolas; Ouahrani-Bettache, Safia; Liautard, Jean-Pierre; Porte, Françoise
Brucella species are gram-negative, facultatively intracellular bacteria that infect humans and animals. These organisms can survive and replicate within a membrane-bound compartment in phagocytic and nonprofessional phagocytic cells. Inhibition of phagosome-lysosome fusion has been proposed as a mechanism for intracellular survival in both types of cells. However, the biochemical mechanisms and microbial factors implicated in Brucella maturation are still completely unknown. We developed two different approaches in an attempt to gain further insight into these mechanisms: (i) a fluorescence microscopy analysis of general intracellular trafficking on whole cells in the presence of Brucella and (ii) a flow cytometry analysis of in vitro reconstitution assays showing the interaction between Brucella suis-containing phagosomes and lysosomes. The fluorescence microscopy results revealed that fusion properties of latex bead-containing phagosomes with lysosomes were not modified in the presence of live Brucella suis in the cells. We concluded that fusion inhibition was restricted to the pathogen phagosome and that the host cell fusion machinery was not altered by the presence of live Brucella in the cell. By in vitro reconstitution experiments, we observed a specific association between killed B. suis-containing phagosomes and lysosomes, which was dependent on exogenously supplied cytosol, energy, and temperature. This association was observed with killed bacteria but not with live bacteria. Hence, this specific recognition inhibition seemed to be restricted to the pathogen phagosomal membrane, as noted in the in vivo experiments. PMID:11119541
The objective of the current study was to evaluate the safety, immunogenicity and clearance of the natural rough mutant of Brucella suis strain 353-1 (353-1) as a vaccine in domestic swine. In three studies encompassing 155 animals, pigs were inoculated with 353-1 by conjunctival (5 x 10**7 CFU), p...
Czibener, Cecilia; Del Giudice, Mariela Giselda; Spera, Juan Manuel; Fulgenzi, Fabiana Rosa; Ugalde, Juan Esteban
Brucellosis is one of the most widespread zoonosis in the world affecting many domestic and wild animals including bovines, goats, pigs and dogs. Each species of the Brucella genus has a particular tropism toward different mammals being the most relevant for human health Brucella abortus, Brucella melitensis and Brucella suis that infect bovines, goats/camelids and swine respectively. Although for B. abortus and B. melitensis there are vaccines available, there is no efficient vaccine to protect swine from B. suis infection so far. We describe here the construction of a novel vaccine strain that confers excellent protection against B. suis in a mouse model of infection. This strain is a clean deletion of the phosphoglucomutase (pgm) gene that codes for a protein that catalyzes the conversion of glucose-6-P to glucose-1-P, which is used as a precursor for the biosynthesis of many polysaccharides. The Delta-pgm strain lacks a complete lipopolysaccharide, is unable to synthesize cyclic beta glucans and is sensitive to several detergents and Polymyxin B. We show that this strain replicates in cultured cells, is completely avirulent in the mouse model of infection but protects against a challenge of the virulent strain inducing the production of pro-inflammatory cytokines. This novel strain could be an excellent candidate for the control of swine brucellosis, a disease of emerging concern in many parts of the world.
with Brucella melitensis WR201(16MDeltapurEK), immunized intramuscularly with dialyzed cell lysate of Infect. Immun. 67 (1999) 5877-5884. B. melitensis ...bacterioferritin gene of Brucella melitensis 16M strain, FEBS Lett. 361 (2-3) (1995) 238-242. serum and derived IgG had strong reaction to the Bru-  L.E. Lindler...detection by the antiserum. The pro- nucleotide sequence, and expression of the Brucella melitensis tein samples were prepared by treatment of WRR51 omp31
Köhler, Stephan; Ouahrani-Bettache, Safia; Layssac, Marion; Teyssier, Jacques; Liautard, Jean-Pierre
A gene fusion system based on plasmid pBBR1MCS and the expression of green fluorescent protein was developed for Brucella suis, allowing isolation of constitutive and inducible genes. Bacteria containing promoter fusions of chromosomal DNA to gfp were visualized by fluorescence microscopy and examined by flow cytometry. Twelve clones containing gene fragments induced inside J774 murine macrophages were isolated and further characterized. PMID:10569794
Wang, Xiangguo; Lin, Pengfei; Li, Yang; Xiang, Caixia; Yin, Yanlong; Chen, Zhi; Du, Yue; Zhou, Dong; Jin, Yaping; Wang, Aihua
Brucella has been reported to impair placental trophoblasts, a cellular target where Brucella efficiently replicates in association with the endoplasmic reticulum (ER), and ultimately trigger abortion in pregnant animals. However, the precise effects of Brucella on trophoblast cells remain unclear. Here, we describe the infection and replication of Brucella suis vaccine strain 2 (B.suis.S2) in goat trophoblast cells (GTCs) and the cellular and molecular responses induced in vitro. Our studies demonstrated that B.suis.S2 was able to infect and proliferate to high titers, hamper the proliferation of GTCs and induce apoptosis due to ER stress. Tunicamycin (Tm), a pharmacological chaperone that strongly mounts ER stress-induced apoptosis, inhibited B.suis.S2 replication in GTCs. In addition, 4 phenyl butyric acid (4-PBA), a pharmacological chaperone that alleviates ER stress-induced apoptosis, significantly enhanced B.suis.S2 replication in GTCs. The Unfolded Protein Response (UPR) chaperone molecule GRP78 also promoted B.suis.S2 proliferation in GTCs by inhibiting ER stress-induced apoptosis. We also discovered that the IRE1 pathway, but not the PERK or ATF6 pathway, was activated in the process. However, decreasing the expression of phosphoIRE1α and IRE1α proteins with Irestatin 9389 (IRE1 antagonist) in GTCs did not affect the proliferation of B.suis.S2. Although GTC implantation was not affected upon B.suis.S2 infection, progesterone secretion was suppressed, and prolactin and estrogen secretion increased; these effects were accompanied by changes in the expression of genes encoding key steroidogenic enzymes. This study systematically explored the mechanisms of abortion in Brucella infection from the viewpoint of pathogen invasion, ER stress and reproductive endocrinology. Our findings may provide new insight for understanding the mechanisms involved in goat abortions caused by Brucella infection.
Wang, Xiangguo; Lin, Pengfei; Li, Yang; Xiang, Caixia; Yin, Yanlong; Chen, Zhi; Du, Yue; Zhou, Dong; Jin, Yaping; Wang, Aihua
Brucella has been reported to impair placental trophoblasts, a cellular target where Brucella efficiently replicates in association with the endoplasmic reticulum (ER), and ultimately trigger abortion in pregnant animals. However, the precise effects of Brucella on trophoblast cells remain unclear. Here, we describe the infection and replication of Brucella suis vaccine strain 2 (B.suis.S2) in goat trophoblast cells (GTCs) and the cellular and molecular responses induced in vitro. Our studies demonstrated that B.suis.S2 was able to infect and proliferate to high titers, hamper the proliferation of GTCs and induce apoptosis due to ER stress. Tunicamycin (Tm), a pharmacological chaperone that strongly mounts ER stress-induced apoptosis, inhibited B.suis.S2 replication in GTCs. In addition, 4 phenyl butyric acid (4-PBA), a pharmacological chaperone that alleviates ER stress-induced apoptosis, significantly enhanced B.suis.S2 replication in GTCs. The Unfolded Protein Response (UPR) chaperone molecule GRP78 also promoted B.suis.S2 proliferation in GTCs by inhibiting ER stress-induced apoptosis. We also discovered that the IRE1 pathway, but not the PERK or ATF6 pathway, was activated in the process. However, decreasing the expression of phosphoIRE1α and IRE1α proteins with Irestatin 9389 (IRE1 antagonist) in GTCs did not affect the proliferation of B.suis.S2. Although GTC implantation was not affected upon B.suis.S2 infection, progesterone secretion was suppressed, and prolactin and estrogen secretion increased; these effects were accompanied by changes in the expression of genes encoding key steroidogenic enzymes. This study systematically explored the mechanisms of abortion in Brucella infection from the viewpoint of pathogen invasion, ER stress and reproductive endocrinology. Our findings may provide new insight for understanding the mechanisms involved in goat abortions caused by Brucella infection. PMID:26904517
Wang, Xiangguo; Lin, Pengfei; Yin, Yanlong; Zhou, Jinhua; Lei, Lanjie; Zhou, Xudong; Jin, Yaping; Wang, Aihua
Brucella, which is regarded as an intracellular pathogen responsible for a zoonotic disease called brucellosis, survives and proliferates within several types of phagocytic and non-phagocytic cells. Brucella infects not only their preferred hosts but also other domestic and wild animal species, inducing abortion and infertility. Therefore, the interaction between uterine cells and Brucella is important for understanding the pathogenesis of this disease. In this study, we describe the Brucella suis vaccine strain S2 (B.suis.S2) infection and replication in the immortalized caprine endometrial epithelial cell line hTERT-EECs and the induced cellular and molecular response modulation in vitro. We found that B.suis S2 was able to infect and replicate to high titers and inhibit the proliferation of EECs and induce non-apoptotic pathways, as determined by B.suis.S2 detection using MTT and acridine orange/ethidium bromide (AO/EB) staining and flow cytometry. We explored the evidence of non-apoptotic pathways using real-time quantitative RT-PCR and by western blot analysis. Finally, we discovered the over-expression of GRP78, ATF4, ATF6, PERK, eIF2α, CHOP, and cytochrome c (Cyt-c) but not IRE1, xbp-1, and caspase-3 in B.suis.S2 (HK)-attacked and B.suis.S2-infected cells, suggesting that the molecular mechanism of ER stress sensor activation by B.suis.S2 is basically concomitant with that by B.suis.S2 (HK) and that ER stress, especially the PERK pathway, plays an important role in the process of B.suis.S2 infecting EEC, which may, in part, explain the role of the uterus in the pathogenesis of B.suis.S2.
Jubier-Maurin, Véronique; Rodrigue, Agnès; Ouahrani-Bettache, Safia; Layssac, Marion; Mandrand-Berthelot, Marie-Andrée; Köhler, Stephan; Liautard, Jean-Pierre
Analysis of a Brucella suis 1330 gene fused to a gfp reporter, and identified as being induced in J774 murine macrophage-like cells, allowed the isolation of a gene homologous to nikA, the first gene of the Escherichia coli operon encoding the specific transport system for nickel. DNA sequence analysis of the corresponding B. suis nik locus showed that it was highly similar to that of E. coli except for localization of the nikR regulatory gene, which lies upstream from the structural nikABCDE genes and in the opposite orientation. Protein sequence comparisons suggested that the deduced nikABCDE gene products belong to a periplasmic binding protein-dependent transport system. The nikA promoter-gfp fusion was activated in vitro by low oxygen tension and metal ion deficiency and was repressed by NiCl2 excess. Insertional inactivation of nikA strongly reduced the activity of the nickel metalloenzyme urease, which was restored by addition of a nickel excess. Moreover, the nikA mutant of B. suis was functionally complemented with the E. coli nik gene cluster, leading to the recovery of urease activity. Reciprocally, an E. coli strain harboring a deleted nik operon recovered hydrogenase activity by heterologous complementation with the B. suis nik locus. Taking into account these results, we propose that the nik locus of B. suis encodes a nickel transport system. The results further suggest that nickel could enter B. suis via other transport systems. Intracellular growth rates of the B. suis wild-type and nikA mutant strains in human monocytes were similar, indicating that nikA was not essential for this step of infection. We discuss a possible role of nickel transport in maintaining enzymatic activities which could be crucial for survival of the bacteria under the environmental conditions encountered within the host. PMID:11133934
Loisel-Meyer, Séverine; Jiménez de Bagüés, Maria Pilar; Bassères, Eugénie; Dornand, Jacques; Köhler, Stephan; Liautard, Jean-Pierre; Jubier-Maurin, Véronique
A mutant of Brucella suis bearing a Tn5 insertion in norD, the last gene of the operon norEFCBQD, encoding nitric oxide reductase, was unable to survive under anaerobic denitrifying conditions. The norD strain exhibited attenuated multiplication within nitric oxide-producing murine macrophages and rapid elimination in mice, hence demonstrating that norD is essential for Brucella virulence. PMID:16495577
Boschiroli, Maria Laura; Ouahrani-Bettache, Safia; Foulongne, Vincent; Michaux-Charachon, Sylvie; Bourg, Gisele; Allardet-Servent, Annick; Cazevieille, Chantal; Liautard, Jean Pierre; Ramuz, Michel; O'Callaghan, David
A type IV secretion system similar to the VirB system of the phytopathogen Agrobacterium tumefaciens is essential for the intracellular survival and multiplication of the mammalian pathogen Brucella. Reverse transcriptase–PCR showed that the 12 genes encoding the Brucella suis VirB system form an operon. Semiquantitative measurements of virB mRNA levels by slot blotting showed that transcription of the virB operon, but not the flanking genes, is regulated by environmental factors in vitro. Flow cytometry used to measure green fluorescent protein expression from the virB promoter confirmed the data from slot blots. Fluorescence-activated cell sorter analysis and fluorescence microscopy showed that the virB promoter is induced in macrophages within 3 h after infection. Induction only occurred once the bacteria were inside the cells, and phagosome acidification was shown to be the major signal inducing intracellular expression. Because phagosome acidification is essential for the intracellular multiplication of Brucella, we suggest that it is the signal that triggers the secretion of unknown effector molecules. These effector molecules play a role in the remodeling of the phagosome to create the unique intracellular compartment in which Brucella replicates. PMID:11830669
Fort, Marcelo; Baldone, Valeria; Fuchs, Lumila; Giménez, Hugo; Rojas, María; Breccia, Javier D; Oyhenart, Jorge
Brucella suis biovar 1 is the causative agent of brucellosis in several domestic and wild animals and it is a common agent of human brucellosis. European hares (Lepus europaeus) have been shown to be infected by B. suis biovar 1 and the transmission to other animals has been suggested. In this work, experimental rabbits (Cuniculus orictolagus) were infected with B. suis biovar 1 isolated from wild hares. Infected rabbits showed high serological response in 2 weeks after discharge and typical granulomatous lesions (2mm diameter) were found in liver, spleen and kidneys after 50 days. B. suis biovar 1 was cultured from the lesion of the organs mentioned above as well as from urine, placenta and fetuses. These data suggest that hares are a potential source for horizontal transmission of B. suis biovar 1 to other mammalians.
Jiang, Hai; Wang, Heng; Xu, Liqing; Hu, Guiying; Ma, Junying; Xiao, Pei; Fan, Weixing; Di, Dongdong; Tian, Guozhong; Fan, Mengguang; Mi, Jingchuan; Yu, Ruiping; Song, Litao; Zhao, Hongyan; Piao, Dongri; Cui, Buyun
In China, brucellosis is an endemic disease and the main sources of brucellosis in animals and humans are infected sheep, cattle and swine. Brucella melitensis (biovars 1 and 3) is the predominant species, associated with sporadic cases and outbreak in humans. Isolates of B. abortus, primarily biovars 1 and 3, and B. suis biovars 1 and 3 are also associated with sporadic human brucellosis. In this study, the genetic profiles of B. melitensis and B. abortus isolates from humans and animals were analyzed and compared by multi-locus variable-number tandem-repeat analysis (MLVA). Among the B. melitensis isolates, the majority (74/82) belonged to MLVA8 genotype 42, clustering in the 'East Mediterranean' group. Two B. melitensis biovar 1 genotype 47 isolates, belonging to the 'Americas' group, were recovered; both were from the Himalayan blue sheep (Pseudois nayaur, a wild animal). The majority of B. abortus isolates (51/70) were biovar 3, genotype 36. Ten B. suis biovar 1 field isolates, including seven outbreak isolates recovered from a cattle farm in Inner Mongolia, were genetically indistinguishable from the vaccine strain S2, based on MLVA cluster analysis. MLVA analysis provided important information for epidemiological trace-back. To the best of our knowledge, this is the first report to associate Brucella cross-infection with the vaccine strain S2 based on molecular comparison of recovered isolates to the vaccine strain. MLVA typing could be an essential assay to improve brucellosis surveillance and control programs.
Kreizinger, Zsuzsa; Foster, Jeffrey T; Rónai, Zsuzsanna; Sulyok, Kinga M; Wehmann, Enikő; Jánosi, Szilárd; Gyuranecz, Miklós
Porcine brucellosis generally manifests as disorders in reproductive organs potentially leading to serious losses in the swine industry. Brucella suis biovar 2 is endemic in European wild boar (Sus scrofa) and hare (Lepus europeus, Lepus capensis) populations, thus these species may play a significant role in disease spread and serve as potential sources of infection for domestic pigs. The aim of this study was an epidemiologic analysis of porcine brucellosis in Hungary and a comparative analysis of B. suis bv. 2 strains from Europe using multiple-locus variable-number tandem repeat analysis (MLVA). MLVA-16 and its MLVA-11 subset were used to determine the genotypes of 68 B. suis bv. 2 isolates from Hungary and results were then compared to European MLVA genotypes. The analyses indicated relatively high genetic diversity of B. suis bv. 2 in Hungary. Strains isolated from hares and wild boars from Hungary showed substantial genetic divergence, suggesting separate lineages in each host and no instances of cross species infections. The closest relatives of strains from Hungarian wild boars and domestic pigs were mainly in the isolates from German and Croatian boars and pigs. The assessment of the European MLVA genotypes of wild boar isolates generally showed clustering based on geographic origin. The hare strains were relatively closely related to one another and did not cluster based on geographic origin. The limited relationships between geographic origin and genotype in isolates from hares might be the result of cross-border live animal translocation. The results could also suggest that certain B. suis strains are more adapted to hares. Across Europe, isolates from domestic pigs were closely related to isolates originating from both hares and wild boars, supporting the idea that wild animals are a source of brucellosis in domestic pigs.
Quance, Christine; Robbe-Austerman, Suelee; Stuber, Tod; Brignole, Tom; DeBess, Emilio E; Boyd, Laurel; LeaMaster, Brad; Tiller, Rebekah; Draper, Jenny; Humphrey, Sharon; Erdman, Matthew M
Brucella suis infection was diagnosed in a man from Tonga, Polynesia, who had butchered swine in Oregon, USA. Although the US commercial swine herd is designated brucellosis-free, exposure history suggested infection from commercial pigs. We used whole-genome sequencing to determine that the man was infected in Tonga, averting a field investigation.
Historically, brucellosis from Brucella suis infection occurred among workers in swine slaughterhouses. In 1972, the U.S. Department of Agriculture National Brucellosis Eradication Program was expanded to cover swine herds. Subsequent elimination of brucellosis in commercial swine resulted in a decrease in B. suis-associated illness in humans. Currently, swine-associated brucellosis in humans in the United States is predominantly associated with exposure to infected feral swine (i.e., wild boar or wild hogs). In May and July 2008, CDC was contacted by the state health departments in South Carolina and Pennsylvania regarding two cases of brucellosis possibly linked to feral swine hunts. Both state health departments contacted the state health department in Florida, where the hunts took place. The subsequent investigation, conducted jointly by the three state health departments and CDC, determined that the two patients had confirmed brucellosis from B. suis infection and the brother of one patient had probable brucellosis. All three exposures were associated with feral swine hunting, and at least two patients did not have symptoms until 4-6 months after exposure. The findings from this investigation suggest that clinicians treating patients with unexplained febrile illness should consider brucellosis in the differential diagnosis and obtain a thorough history of travel (e.g., to enzootic areas), food consumption, occupation, and recreational activities, including feral swine hunting. Cross-agency collaboration by state health departments and agriculture agencies is needed on brucellosis investigations to reduce the risk for illness through contact with infected animals.
Jubier-Maurin, Véronique; Boigegrain, Rose-Anne; Cloeckaert, Axel; Gross, Antoine; Alvarez-Martinez, Maria-Teresa; Terraza, Annie; Liautard, Janny; Köhler, Stephan; Rouot, Bruno; Dornand, Jacques; Liautard, Jean Pierre
Brucella spp. can establish themselves and cause disease in humans and animals. The mechanisms by which Brucella spp. evade the antibacterial defenses of their host, however, remain largely unknown. We have previously reported that live brucellae failed to induce tumor necrosis factor alpha (TNF-α) production upon human macrophage infection. This inhibition is associated with a nonidentified protein that is released into culture medium. Outer membrane proteins (OMPs) of gram-negative bacteria have been shown to modulate macrophage functions, including cytokine production. Thus, we have analyzed the effects of two major OMPs (Omp25 and Omp31) of Brucella suis 1330 (wild-type [WT] B. suis) on TNF-α production. For this purpose, omp25 and omp31 null mutants of B. suis (Δomp25 B. suis and Δomp31 B. suis, respectively) were constructed and analyzed for the ability to activate human macrophages to secrete TNF-α. We showed that, in contrast to WT B. suis or Δomp31 B. suis, Δomp25 B. suis induced TNF-α production when phagocytosed by human macrophages. The complementation of Δomp25 B. suis with WT omp25 (Δomp25-omp25 B. suis mutant) significantly reversed this effect: Δomp25-omp25 B. suis-infected macrophages secreted significantly less TNF-α than did macrophages infected with the Δomp25 B. suis mutant. Furthermore, pretreatment of WT B. suis with an anti-Omp25 monoclonal antibody directed against an epitope exposed at the surface of the bacteria resulted in substancial TNF-α production during macrophage infection. These observations demonstrated that Omp25 of B. suis is involved in the negative regulation of TNF-α production upon infection of human macrophages. PMID:11447156
Posadas, Diana M.; Martín, Fernando A.; Sabio y García, Julia V.; Spera, Juan M.; Delpino, M. Victoria; Baldi, Pablo; Campos, Eleonora; Cravero, Silvio L.; Zorreguieta, Angeles
Brucella spp., like other pathogens, must cope with the environment of diverse host niches during the infection process. In doing this, pathogens evolved different type of transport systems to help them survive and disseminate within the host. Members of the TolC family have been shown to be involved in the export of chemically diverse molecules ranging from large protein toxins to small toxic compounds. The role of proteins from the TolC family in Brucella and other α-2-proteobacteria has been explored little. The gene encoding the unique member of the TolC family from Brucella suis (BepC) was cloned and expressed in an Escherichia coli mutant disrupted in the gene encoding TolC, which has the peculiarity of being involved in diverse transport functions. BepC fully complemented the resistance to drugs such as chloramphenicol and acriflavine but was incapable of restoring hemolysin secretion in the tolC mutant of E. coli. An insertional mutation in the bepC gene strongly affected the resistance phenotype of B. suis to bile salts and toxic chemicals such as ethidium bromide and rhodamine and significantly decreased the resistance to antibiotics such as erythromycin, ampicillin, tetracycline, and norfloxacin. Moreover, the B. suis bepC mutant was attenuated in the mouse model of infection. Taken together, these results suggest that BepC-dependent efflux processes of toxic compounds contribute to B. suis survival inside the host. PMID:17088356
Liautard, Janny; Ouahrani-Bettache, Safia; Jubier-Maurin, Véronique; Lafont, Virginie; Köhler, Stephan; Liautard, Jean-Pierre
Brucella strains are facultative intracellular pathogens that induce chronic diseases in humans and animals. This observation implies that Brucella subverts innate and specific immune responses of the host to develop its full virulence. Deciphering the genes involved in the subversion of the immune system is of primary importance for understanding the virulence of the bacteria, for understanding the pathogenic consequences of infection, and for designing an efficient vaccine. We have developed an in vitro system involving human macrophages infected by Brucella suis and activated syngeneic γ9δ2 T lymphocytes. Under these conditions, multiplication of B. suis inside macrophages is only slightly reduced. To identify the genes responsible for this reduced sensitivity, we screened a library of 2,000 clones of transposon-mutated B. suis. For rapid and quantitative analysis of the multiplication of the bacteria, we describe a simple method based on Alamar blue reduction, which is compatible with screening a large library. By comparing multiplication inside macrophages alone and multiplication inside macrophages with activated γ9δ2 T cells, we identified four genes of B. suis that were necessary to resist to the action of the γ9δ2 T cells. The putative functions of these genes are discussed in order to propose possible explanations for understanding their exact role in the subversion of innate immunity. PMID:17709411
Ekaza, Euloge; Teyssier, Jacques; Ouahrani-Bettache, Safia; Liautard, Jean-Pierre; Köhler, Stephan
Pathogens often encounter stressful conditions inside their hosts. In the attempt to characterize the stress response in Brucella suis, a gene highly homologous to Escherichia coli clpB was isolated from Brucella suis, and the deduced amino acid sequence showed features typical of the ClpB ATPase family of stress response proteins. Under high-temperature stress conditions, ClpB of B. suis was induced, and an isogenic B. suis clpB mutant showed increased sensitivity to high temperature, but also to ethanol stress and acid pH. The effects were reversible by complementation. Simultaneous inactivation of clpA and clpB resulted in a mutant that was sensitive to oxidative stress. In B. suis expressing gfp, ClpA but not ClpB participated in degradation of the green fluorescent protein at 42°C. We concluded that ClpB was responsible for tolerance to several stresses and that the lethality caused by harsh environmental conditions may have similar molecular origins. PMID:11274130
Billard, Elisabeth; Dornand, Jacques; Gross, Antoine
Brucella is a facultative intracellular pathogen and the etiological agent of brucellosis. In some cases, human brucellosis results in a persistent infection that may reactivate years after the initial exposure. The mechanisms by which the parasite evades clearance by the immune response to chronically infect its host are unknown. We recently demonstrated that dendritic cells (DCs), which are critical components of adaptive immunity, are highly susceptible to Brucella infection and are a preferential niche for the development of the bacteria. Here, we report that in contrast to several intracellular bacteria, Brucella prevented the infected DCs from engaging in their maturation process and impaired their capacities to present antigen to naïve T cells and to secrete interleukin-12. Moreover, Brucella-infected DCs failed to release tumor necrosis factor alpha (TNF-alpha), a defect involving the bacterial protein Omp25. Exogenous TNF-alpha addition to Brucella-infected DCs restored cell maturation and allowed them to present antigens. Two avirulent mutants of B. suis, B. suis bvrR and B. suis omp25 mutants, which do not express the Omp25 protein, triggered TNF-alpha production upon DC invasion. Cells infected with these mutants subsequently matured and acquired the ability to present antigens, two properties which were dramatically impaired by addition of anti-TNF-alpha antibodies. In light of these data, we propose a model in which virulent Brucella alters the maturation and functions of DCs through Omp25-dependent control of TNF-alpha production. This model defines a specific evasion strategy of the bacteria by which they can escape the immune response to chronically infect their host.
Mancini, Daiana T; Matos, Karina S; da Cunha, Elaine F F; Assis, Tamiris M; Guimarães, Ana P; França, Tanos C C; Ramalho, Teodorico C
Brucella suis is a dangerous biological warfare agent already used for military purposes. This bacteria cause brucellosis, a zoonosis highly infective and difficult to fight. An important selective target for chemotherapy against this disease is nucleoside hydrolase (NH), an enzyme still not found in mammals. We present here the first three-dimensional structure of B. suis NH (BsNH) and propose this enzyme as a molecular target to the drug design in the fight against brucellosis. In addition, we performed molecular docking studies, aiming to analyze the three-dimensional positioning of nine known inhibitors of Chritidia fasciculata NH (CfNH) in the active sites of BsNH and CfNH. We also analyzed the main interactions of some of these compounds inside the active site of BsNH and the relevant factors to biological activity. These results, together with further molecular dynamics (MD) simulations, pointed out to the most promising compound as lead for the design of potential inhibitors of BsNH. Most of the docking and MD results corroborated to each other and the docking results also suggested a good correlation with experimental data.
Alvarez-Martinez, Maria-Teresa; Machold, Jan; Weise, Christoph; Schmidt-Eisenlohr, Heike; Baron, Christian; Rouot, Bruno
Brucella strains possess an operon encoding type IV secretion machinery very similar to that coded by the Agrobacterium tumefaciens virB operon. Here we describe cloning of the Brucella suis homologue of the chvE-gguA-gguB operon of A. tumefaciens and characterize the sugar binding protein ChvE (78% identity), which in A. tumefaciens is involved in virulence gene expression. B. suis chvE is upstream of the putative sugar transporter-encoding genes gguA and gguB, also present in A. tumefaciens, but not adjacent to that of a LysR-type transcription regulator. Although results of Southern hybridization experiments suggested that the gene is present in all Brucella strains, the ChvE protein was detected only in B. suis and Brucella canis with A. tumefaciens ChvE-specific antisera, suggesting that chvE genes are differently expressed in different Brucella species. Analysis of cell growth of B. suis and of its chvE or gguA mutants in different media revealed that ChvE exhibited a sugar specificity similar to that of its A. tumefaciens homologue and that both ChvE and GguA were necessary for utilization of these sugars. Murine or human macrophage infections with B. suis chvE and gguA mutants resulted in multiplication similar to that of the wild-type strain, suggesting that virB expression was unaffected. These data indicate that the ChvE and GguA homologous proteins of B. suis are essential for the utilization of certain sugars but are not necessary for survival and replication inside macrophages. PMID:11514518
Duvnjak, Sanja; Račić, Ivana; Špičić, Silvio; Zdelar-Tuk, Maja; Reil, Irena; Cvetnić, Željko
Porcine brucellosis is a common bacterial zoonosis which can cause significant financial losses. Its diverse and often complicated factors have hampered efforts to control disease spread. The aim of the study was to assess the epidemiological situation of porcine brucellosis primarily in Croatia and its relationship to genotypes present in other, mostly European countries. One hundred and seven Brucella suis strains isolated from swine, hares, cattle, humans, wild hares, a wild boar and a mare originating mainly from Croatia (112), but also a few from Slovenia, Bosnia and Herzegovina, Serbia and Macedonia (15) were tested using classical microbiological testing, Bruce-ladder, RFLP, Multiplex-suis and genotyped using multi-locus variable-number tandem repeat analysis (MLVA). We determined 43 Brucella suis genotypes. Strains were grouped according to phylogenetic and geographic relationships, revealing both regional specificity and uniqueness and suggesting possible sources and modes of spread among animals. Our study also confirmed problems with Bruce19 locus that may hinder comparisons of new types with those in the international database. Forty-one novel genotypes were identified and deposited into the international database. Our study supports the idea of wild animals as a source of disease in domestic animals and also gives evidence to hypothesis of cross-border animal trafficking between former Yugoslavian countries. It also highlights the need to expand such research across more of southeast Europe, especially to countries with poorer social and economical situation in order to prevent a realistic outbreak and for better understanding of the biology of this pathogen.
Ruiz-Ranwez, Verónica; Posadas, Diana M.; Van der Henst, Charles; Estein, Silvia M.; Arocena, Gastón M.; Abdian, Patricia L.; Martín, Fernando A.; Sieira, Rodrigo; De Bolle, Xavier
Brucella is responsible for brucellosis, one of the most common zoonoses worldwide that causes important economic losses in several countries. Increasing evidence indicates that adhesion of Brucella spp. to host cells is an important step to establish infection. We have previously shown that the BmaC unipolar monomeric autotransporter mediates the binding of Brucella suis to host cells through cell-associated fibronectin. Our genome analysis shows that the B. suis genome encodes several additional potential adhesins. In this work, we characterized a predicted trimeric autotransporter that we named BtaE. By expressing btaE in a nonadherent Escherichia coli strain and by phenotypic characterization of a B. suis ΔbtaE mutant, we showed that BtaE is involved in the binding of B. suis to hyaluronic acid. The B. suis ΔbtaE mutant exhibited a reduction in the adhesion to HeLa and A549 epithelial cells compared with the wild-type strain, and it was outcompeted by the wild-type strain in the binding to HeLa cells. The knockout btaE mutant showed an attenuated phenotype in the mouse model, indicating that BtaE is required for full virulence. BtaE was immunodetected on the bacterial surface at one cell pole. Using old and new pole markers, we observed that both the BmaC and BtaE adhesins are consistently associated with the new cell pole, suggesting that, in Brucella, the new pole is functionally differentiated for adhesion. This is consistent with the inherent polarization of this bacterium, and its role in the invasion process. PMID:23319562
Wallach, J C; García, J L; Cardinali, P S; Seijo, A P; Benchetrit, A G; Echazarreta, S E; Garro, S L; Deodato, B; Baldi, P C
Epidemiological and clinical aspects of Brucella suis infection in 17 workers from a pork processing plant in Argentina occurring between January 2014 and July 2015 are presented. All patients reported working 9 h daily without adequate personal protection garment. Blood cultures were positive for Brucella spp. in 14 of the 17 patients (82.3%). All isolates were identified as B. suis biovar 1. Although fever, sweats, asthenia, myalgia and hepatic involvement were the most frequent clinical manifestations, an unusually high incidence of respiratory involvement was found. From 13 patients in which chest radiography was performed, four (30%) had radiological abnormalities, including lobar pneumonia in two cases (one with pleural effusion) and interstitial involvement in other two. The high frequency of respiratory involvement in our series makes necessary to consider brucellosis in the differential diagnosis of respiratory diseases in pork processing plant employees.
Ruiz-Ranwez, Verónica; Posadas, Diana M.; Estein, Silvia M.; Abdian, Patricia L.; Martin, Fernando A.; Zorreguieta, Angeles
The adhesion of bacterial pathogens to host cells is an event that determines infection, and ultimately invasion and intracellular multiplication. Several evidences have recently shown that this rule is also truth for the intracellular pathogen Brucella. Brucella suis displays the unipolar BmaC and BtaE adhesins, which belong to the monomeric and trimeric autotransporter (TA) families, respectively. It was previously shown that these adhesins are involved in bacterial adhesion to host cells and components of the extracellular matrix (ECM). In this work we describe the role of a new member of the TA family of B. suis (named BtaF) in the adhesive properties of the bacterial surface. BtaF conferred the bacteria that carried it a promiscuous adhesiveness to various ECM components and the ability to attach to an abiotic surface. Furthermore, BtaF was found to participate in bacterial adhesion to epithelial cells and was required for full virulence in mice. Similar to BmaC and BtaE, the BtaF adhesin was expressed in a small subpopulation of bacteria, and in all cases, it was detected at the new pole generated after cell division. Interestingly, BtaF was also implicated in the resistance of B. suis to porcine serum. Our findings emphasize the impact of TAs in the Brucella lifecycle. PMID:24236157
Galindo, Ruth C; Muñoz, Pilar M; de Miguel, María J; Marin, Clara M; Labairu, Javier; Revilla, Miguel; Blasco, José M; Gortazar, Christian; de la Fuente, José
Brucella suis is responsible for swine brucellosis worldwide. Of the five different B. suis biovars (bv.), bv. 2 appears restricted to Europe where it is frequently isolated from wild boar and hares, can infect pigs and can cause human brucellosis. In this study, the differential gene expression profile was characterized in spleens of Eurasian wild boar naturally infected with B. suis bv. 2. Of the 20,201 genes analyzed in the microarray, 633 and 1,373 were significantly (fold change > 1.8; P < 0.01) upregulated and downregulated, respectively, in infected wild boar. The analysis was focused on genes that were over represented after conditional test for biological process gene ontology. Upregulated genes suggested that B. suis bv. 2 infection induced cell maturation, migration and/or proliferation in infected animals. The genes downregulated in infected wild boar impaired the activity of several important cellular metabolic pathways such as metabolism, cytoskeleton organization and biogenesis, immune response and lysosomal function and vesicle-mediated transport. In addition, the response to stress, sperm fertility, muscle development and apoptosis seemed to be also impaired in infected animals. These results suggested that B. suis bv. 2 may use strategies similar to other smooth brucellae to facilitate intracellular multiplication and the development of chronic infections. To our knowledge, this is the first report of the analysis of gene expression profile in hosts infected with B. suis bv. 2, which is important to understand the molecular mechanisms at the host-pathogen interface in the main reservoir species with possible implications in the zoonotic cycle of the pathogen.
Brucella are intracellular pathogens that cause reproductive losses in animals and zoonotic infections in people. Although named by preferred host species, members of the Brucella genus are capable of infecting multiple species. In preferred hosts, clinical symptoms are generally minimal whereas m...
Köhler, Stephan; Foulongne, Vincent; Ouahrani-Bettache, Safia; Bourg, Gisèle; Teyssier, Jacques; Ramuz, Michel; Liautard, Jean-Pierre
The pathogen Brucella suis resides and multiplies within a phagocytic vacuole of its host cell, the macrophage. The resulting complex relationship has been investigated by the analysis of the set of genes required for virulence, which we call intramacrophagic virulome. Ten thousand two hundred and seventy-two miniTn5 mutants of B. suis constitutively expressing gfp were screened by fluorescence microscopy for lack of intracellular multiplication in human macrophages. One hundred thirty-one such mutants affected in 59 different genes could be isolated, and a function was ascribed to 53 of them. We identified genes involved in (i) global adaptation to the intracellular environment, (ii) amino acid, and (iii) nucleotide synthesis, (iv) sugar metabolism, (v) oxidoreduction, (vi) nitrogen metabolism, (vii) regulation, (viii) disulphide bond formation, and (ix) lipopolysaccharide biosynthesis. Results led to the conclusion that the replicative compartment of B. suis is poor in nutrients and characterized by low oxygen tension, and that nitrate may be used for anaerobic respiration. Intramacrophagic virulome analysis hence allowed the description of the nature of the replicative vacuole of the pathogen in the macrophage and extended our understanding of the niche in which B. suis resides. We propose calling this specific compartment “brucellosome.” PMID:12438693
Fercher, Christian; Probst, Ines; Kohler, Verena; Goessweiner-Mohr, Nikolaus; Arends, Karsten; Grohmann, Elisabeth; Zangger, Klaus; Meyer, N. Helge; Keller, Walter
Untreatable bacterial infections caused by a perpetual increase of antibiotic resistant strains represent a serious threat to human healthcare in the 21st century. Conjugative DNA transfer is the most important mechanism for antibiotic resistance and virulence gene dissemination among bacteria and is mediated by a protein complex, known as type IV secretion system (T4SS). The core of the T4SS is a multiprotein complex that spans the bacterial envelope as a channel for macromolecular secretion. We report the NMR structure and functional characterization of the transfer protein TraH encoded by the conjugative Gram-positive broad-host range plasmid pIP501. The structure exhibits a striking similarity to VirB8 proteins of Gram-negative secretion systems where they play an essential role in the scaffold of the secretion machinery. Considering TraM as the first VirB8-like protein discovered in pIP501, TraH represents the second protein affiliated with this family in the respective transfer operon. A markerless traH deletion in pIP501 resulted in a total loss of transfer in Enterococcus faecalis as compared with the pIP501 wild type (wt) plasmid, demonstrating that TraH is essential for pIP501 mediated conjugation. Moreover, oligomerization state and topology of TraH in the native membrane were determined providing insights in molecular organization of a Gram-positive T4SS. PMID:27103580
Background In the intracellular pathogen Brucella spp., the activation of the stringent response, a global regulatory network providing rapid adaptation to growth-affecting stress conditions such as nutrient deficiency, is essential for replication in the host. A single, bi-functional enzyme Rsh catalyzes synthesis and hydrolysis of the alarmone (p)ppGpp, responsible for differential gene expression under stringent conditions. Results cDNA microarray analysis allowed characterization of the transcriptional profiles of the B. suis 1330 wild-type and Δrsh mutant in a minimal medium, partially mimicking the nutrient-poor intramacrophagic environment. A total of 379 genes (11.6% of the genome) were differentially expressed in a rsh-dependent manner, of which 198 were up-, and 181 were down-regulated. The pleiotropic character of the response was confirmed, as the genes encoded an important number of transcriptional regulators, cell envelope proteins, stress factors, transport systems, and energy metabolism proteins. Virulence genes such as narG and sodC, respectively encoding respiratory nitrate reductase and superoxide dismutase, were under the positive control of (p)ppGpp, as well as expression of the cbb3-type cytochrome c oxidase, essential for chronic murine infection. Methionine was the only amino acid whose biosynthesis was absolutely dependent on stringent response in B. suis. Conclusions The study illustrated the complexity of the processes involved in adaptation to nutrient starvation, and contributed to a better understanding of the correlation between stringent response and Brucella virulence. Most interestingly, it clearly indicated (p)ppGpp-dependent cross-talk between at least three stress responses playing a central role in Brucella adaptation to the host: nutrient, oxidative, and low-oxygen stress. PMID:23834488
Porte, Françoise; Naroeni, Aroem; Ouahrani-Bettache, Safia; Liautard, Jean-Pierre
Brucella species are gram-negative, facultative intracellular bacteria that infect humans and animals. These organisms can survive and replicate within a membrane-bound compartment inside professional and nonprofessional phagocytic cells. Inhibition of phagosome-lysosome fusion has been proposed as a mechanism for intracellular survival in both cell types. However, the molecular mechanisms and the microbial factors involved are poorly understood. Smooth lipopolysaccharide (LPS) of Brucella has been reported to be an important virulence factor, although its precise role in pathogenesis is not yet clear. In this study, we show that the LPS O side chain is involved in inhibition of the early fusion between Brucella suis-containing phagosomes and lysosomes in murine macrophages. In contrast, the phagosomes containing rough mutants, which fail to express the O antigen, rapidly fuse with lysosomes. In addition, we show that rough mutants do not enter host cells by using lipid rafts, contrary to smooth strains. Thus, we propose that the LPS O chain might be a major factor that governs the early behavior of bacteria inside macrophages. PMID:12595466
The genus Brucella encompasses a group of gram negative bacteria that survive almost exclusively in infected hosts with preference for localization in intracellular compartments of cells. The genus has traditionally been divided into species based on microbe characteristics and host preference, bu...
Background Due to the parallel increase of the number of free-ranging wild boar and domestic pigs reared outdoor, the risk that they interact has become higher. Contacts with wild boar can be the origin of disease outbreaks in pigs, as it has been documented for brucellosis in some European countries. This study aimed at quantifying the occurrence of contacts between wild boar and outdoor domestic pigs in Switzerland, and identifying risk factors for these contacts. Furthermore, exposed pigs were tested for pathogen spill-over, taking Brucella suis as an example because B. suis is widespread in Swiss wild boar while domestic pigs are officially free of brucellosis. Results Thirty-one percent of the game-wardens and 25% of the pig owners participating to a country-wide questionnaire survey reported contacts, including approaches of wild boar outside the fence, intrusions, and mating. Seventeen piggeries (5%) reported the birth of cross-bred animals. Risk factors for contacts identified by a uni- and multivariable logistic regression approach were: distance between pigs enclosure and houses, proximity of a forest, electric fences, and fences ≤ 60 cm. Pigs of the Mangalitza breed were most at risk for mating with wild boar (births of cross-bred animals). Blood and tissues of 218 outdoor pigs from 13 piggeries were tested for an infection with Brucella suis, using rose bengal test, complement fixation test, and an IS711-based real-time PCR. One piggery with previous wild boar contacts was found infected with B. suis, however, epidemiological investigations failed to identify the direct source of infection. Conclusions Results show that interactions between wild boar and outdoor pigs are not uncommon, pointing at the existing risk of pathogen spill-over. Provided data on risk factors for these interactions could help the risk-based implementation of protection measures for piggeries. The documentation of a brucellosis outbreak in pigs despite the freedom
Lavigne, Jean-Philippe; O'Callaghan, David; Blanc-Potard, Anne-Béatrice
A Brucella suis mgtC mutant is defective for growth within macrophages and in low-Mg2+ medium. These phenotypes are strikingly similar to those observed with mgtC mutants from Salmonella enterica and Mycobacterium tuberculosis, two other pathogens that proliferate within phagosomes. MgtC appears as a remarkable virulence factor that would have been acquired by distantly related intracellular pathogens to contribute to the adaptation to a low-Mg2+ environment in the phagosome. PMID:15845525
Du, Zhi-Qiang; Li, Xin; Wang, Jian-Ying
Brucella was an intracellular parasite, which could infect special livestock and humans. After infected by Brucella, livestock's reproductive system could be affected and destroyed resulting in huge economic losses. More seriously, it could be contagious from livestock to humans. So far, there is no available vaccine which is safe enough for humans. On this point, subunit vaccine has become the new breakthrough of conquering brucellosis. In this study, Brucella rL7/L12-BLS fusion protein was used as an antigen to immunize rabbits to detect the immunogenicity. The results of antibody level testing assay of rabbit antiserum indicated rL7/L12-BLS fusion protein could elicit rabbits to produce high-level IgG. And gamma interferon (IFN-γ) concentrations in rabbit antiserum were obviously up-regulated in both the rL7/L12 group and rL7/L12-BLS group. Besides, the results of quantitative real-time PCR (qRT-PCR) showed the IFN-γ gene's expression levels of both the rL7/L12 group and rL7/L12-BLS group were obviously up-regulated. All these results suggested Brucella L7/L12 protein was an ideal subunit vaccine candidate and possessed good immunogenicity. And Brucella lumazine synthase (BLS) molecule was a favorable transport vector for antigenic protein.
Twenty Hereford heifers, approximately 9 months of age, were vaccinated with saline (control) or 2 x 10**10 CFU of Brucella abortus strain RB51 (RB51) vaccine. Immunologic responses after inoculation demonstrated significantly greater (P<0.05) antibody and proliferative responses to RB51 antigens i...
Olsen, S C; Palmer, M V
Fifty years ago, bacteria in the genus Brucella were known to cause infertility and reproductive losses. At that time, the genus was considered to contain only 3 species: Brucella abortus, Brucella melitensis, and Brucella suis. Since the early 1960s, at least 7 new species have been identified as belonging to the Brucella genus (Brucella canis, Brucella ceti, Brucella inopinata, Brucella microti, Brucella neotomae, Brucella ovis, and Brucella pinnipedialis) with several additional new species under consideration for inclusion. Although molecular studies have found such high homology that some authors have proposed that all Brucella are actually 1 species, the epidemiologic and diagnostic benefits for separating the genus based on phenotypic characteristics are more compelling. Although pathogenic Brucella spp have preferred reservoir hosts, their ability to infect numerous mammalian hosts has been increasingly documented. The maintenance of infection in new reservoir hosts, such as wildlife, has become an issue for both public health and animal health regulatory personnel. Since the 1960s, new information on how Brucella enters host cells and modifies their intracellular environment has been gained. Although the pathogenesis and histologic lesions of B. abortus, B. melitensis, and B. suis in their preferred hosts have not changed, additional knowledge on the pathology of these brucellae in new hosts, or of new species of Brucella in their preferred hosts, has been obtained. To this day, brucellosis remains a significant human zoonosis that is emerging or reemerging in many parts of the world.
Moreno, Edgardo; Cloeckaert, Axel; Moriyón, Ignacio
The genus Brucella contains alpha-Proteobacteria adapted to intracellular life within cells of a variety of mammals. Controversy has arisen concerning Brucella internal taxonomy, and it has been proposed that the DNA-DNA hybridization-based genomospecies concept be applied to the genus. According to this view, only one species, Brucella melitensis, should be recognized, and the classical species should be considered as biovars (B. melitensis biovar melitensis; B. melitensis biovar abortus; etc.). However, a critical reappraisal of the species concept, a review of the population structure of bacteria and the analysis of Brucella genetic diversity by methods other than DNA-DNA hybridization show that there are no scientific grounds to apply the genomospecies concept to this genus. On the other hand, an enlarged biological species concept allows the definition of Brucella species that are consistent with molecular analyses and support the taxonomical standing of most classical species. Both the host range as a long-recognized biological criterion and the presence of species-specific markers in outer membrane protein genes and in other genes show that B. melitensis, B. abortus, B. ovis, B. canis and B. neotomae are not mere pathovars (or nomenspecies) but biologically meaningful species. The status of B. suis is, however, less clear. These approaches should be useful to define species for the marine mammal Brucella isolates, as illustrated by the grouping of the isolates from pinnipeds or from cetaceans by omp2 gene analysis. It is shown that a correct Brucella species definition is important to understand the evolution of the genus.
Cherwonogrodzky, John W; Barabé, Nicole D; Grigat, Michelle L; Lee, William E; Poirier, Robert T; Jager, Scott J; Berger, Bradley J
A subunit vaccine candidate was produced from Brucella suis 145 (biovar 4; expressing both the A antigen of Brucella abortus and the M antigen of Brucella melitensis). The preparation consisted mostly of polysaccharide (PS; >90% [wt/wt]; both cell-associated PS and exo-PS were combined) and a small amount of protein (1 to 3%) with no apparent nucleic acids. Vaccinated mice were protected (these had a statistically significant reduction in bacterial colonization compared to that of unvaccinated controls) when challenged with representative strains of three Brucella species most pathogenic for humans, i.e., B. abortus, B. melitensis, and B. suis. As little as 1 ng of the vaccine, without added adjuvant, protected mice against B. suis 145 infection (5 × 10(5) CFU), and a single injection of 1 μg of this subunit vaccine protected mice from B. suis 145 challenge for at least 14 months. A single immunization induced a serum IgG response to Brucella antigens that remained elevated for up to 9 weeks. The use of heat (i.e., boiling-water bath, autoclaving) in the vaccine preparation showed that it was thermostable. This method also ensured safety and security. The vaccine produced was immunogenic and highly protective against multiple strains of Brucella and represents a promising candidate for further evaluation.
Meyer, Margaret E.; Cameron, H. S.
Meyer, Margaret E. (University of California, Davis), and H. S. Cameron. Metabolic characterization of the genus Brucella. I. Statistical evaluation of the oxidative rates by which type I of each species can be identified. J. Bacteriol. 82:387–395. 1961.—The oxidative uptake rates on 11 amino acid and seven carbohydrate substrates were determined for 75 strains of brucellae that had been identified by the conventional determinative methods as Brucella melitensis type I, Brucella abortus type I, or Brucella suis type I. By calculating the standard deviation of the oxidative rates, it was demonstrated that a metabolic pattern that is characteristic and definitive for each of the species was formed by their differential oxidative utilization of substrate groups, and that qualitative as well as quantitative metabolic differences exist among the Brucella species. B. melitensis oxidized l-alanine, l-asparagine, and l-glutamic acid, but not l-arginine, dl-citrulline, l-lysine, dl-ornithine, l-arabinose, d-galactose, d-ribose, or d-xylose. B. abortus differed qualitatively from B. melitensis in that it oxidized the carbohydrate substrates. B. suis differed quantitatively from both of these species in its consistently low oxidative rates of l-alanine, l-asparagine, and l-glutamic acid, and its high rates of utilization of the carbohydrate substrates. It differed qualitatively in that it oxidized the four amino acid substrates that are components of the urea cycle. PMID:13770011
Silva, Teane M. A.; Mol, Juliana P. S.; Winter, Maria G.; Atluri, Vidya; Xavier, Mariana N.; Pires, Simone F.; Paixão, Tatiane A.; Andrade, Hélida M.; Santos, Renato L.; Tsolis, Renee M.
Brucella ovis is a major cause of reproductive failure in rams and it is one of the few well-described Brucella species that is not zoonotic. Previous work showed that a B. ovis mutant lacking a species-specific ABC transporter (ΔabcBA) was attenuated in mice and was unable to survive in macrophages. The aim of this study was to evaluate the role of this ABC transporter during intracellular survival of B. ovis. In HeLa cells, B. ovis WT was able to survive and replicate at later time point (48 hpi), whereas an ΔabcBA mutant was attenuated at 24 hpi. The reduced survival of the ΔabcBA mutant was associated with a decreased ability to exclude the lysosomal marker LAMP1 from its vacuolar membrane, suggesting a failure to establish a replicative niche. The ΔabcBA mutant showed a reduced abundance of the Type IV secretion system (T4SS) proteins VirB8 and VirB11 in both rich and acid media, when compared to WT B. ovis. However, mRNA levels of virB1, virB8, hutC, and vjbR were similar in both strains. These results support the notion that the ABC transporter encoded by abcEDCBA or its transported substrate acts at a post-transcriptional level to promote the optimal expression of the B. ovis T4SS within infected host cells. PMID:25474545
Baldridge, Gerald D; Li, Yang Grace; Witthuhn, Bruce A; Higgins, LeeAnn; Markowski, Todd W; Baldridge, Abigail S; Fallon, Ann M
The obligate intracellular bacterium, Wolbachia pipientis (Rickettsiales), is a widespread, vertically transmitted endosymbiont of filarial nematodes and arthropods. In insects, Wolbachia modifies reproduction, and in mosquitoes, infection interferes with replication of arboviruses, bacteria and plasmodia. Development of Wolbachia as a tool to control pest insects will be facilitated by an understanding of molecular events that underlie genetic exchange between Wolbachia strains. Here, we used nucleotide sequence, transcriptional and proteomic analyses to evaluate expression levels and establish the mosaic nature of genes flanking the T4SS virB8-D4 operon from wStr, a supergroup B-strain from a planthopper (Hemiptera) that maintains a robust, persistent infection in an Aedes albopictus mosquito cell line. Based on protein abundance, ribA, which contains promoter elements at the 5'-end of the operon, is weakly expressed. The 3'-end of the operon encodes an intact wspB, which encodes an outer membrane protein and is co-transcribed with the vir genes. WspB and vir proteins are expressed at similar, above average abundance levels. In wStr, both ribA and wspB are mosaics of conserved sequence motifs from Wolbachia supergroup A- and B-strains, and wspB is nearly identical to its homolog from wCobU4-2, an A-strain from weevils (Coleoptera). We describe conserved repeated sequence elements that map within or near pseudogene lesions and transitions between A- and B-strain motifs. These studies contribute to ongoing efforts to explore interactions between Wolbachia and its host cell in an in vitro system.
Michaux-Charachon, Sylvie; Jumas-Bilak, Estelle; Allardet-Servent, Annick; Bourg, Gisele; Boschiroli, Maria Laura; Ramuz, Michel; O'Callaghan, David
The year 2002 began with the publication of the first complete genome sequence for a Brucella species, that of the two replicons of B. melitensis 16M. Hopefully in 2002, the complete genome of B. suis 1330, and, perhaps, a B. abortus strain will be published. This is the culmination of over 30 years investigation of the composition, structure, organisation and evolution of the Brucella genome. Brucella research must now adapt to the new challenges of the post-genomic era.
De Miguel, M J; Marín, C M; Muñoz, P M; Dieste, L; Grilló, M J; Blasco, J M
Bacteriological diagnosis of brucellosis is performed by culturing animal samples directly on both Farrell medium (FM) and modified Thayer-Martin medium (mTM). However, despite inhibiting most contaminating microorganisms, FM also inhibits the growth of Brucella ovis and some B. melitensis and B. abortus strains. In contrast, mTM is adequate for growth of all Brucella species but only partially inhibitory for contaminants. Moreover, the performance of both culture media for isolating B. suis has never been established properly. We first determined the performance of both media for B. suis isolation, proving that FM significantly inhibits B. suis growth. We also determined the susceptibility of B. suis to the antibiotics contained in both selective media, proving that nalidixic acid and bacitracin are highly inhibitory, thus explaining the reduced performance of FM for B. suis isolation. Based on these results, a new selective medium (CITA) containing vancomycin, colistin, nystatin, nitrofurantoin, and amphotericin B was tested for isolation of the main Brucella species, including B. suis. CITA's performance was evaluated using reference contaminant strains but also field samples taken from brucella-infected animals or animals suspected of infection. CITA inhibited most contaminant microorganisms but allowed the growth of all Brucella species, to levels similar to those for both the control medium without antibiotics and mTM. Moreover, CITA medium was more sensitive than both mTM and FM for isolating all Brucella species from field samples. Altogether, these results demonstrate the adequate performance of CITA medium for the primary isolation of the main Brucella species, including B. suis.
Meyer, Margaret E.
Meyer, Margaret E. (University of California, Davis). Metabolic characterization of the genus Brucella. III. Oxidative metabolism of strains that show anomalous characteristics by conventional determinative methods. J. Bacteriol. 82:401–410. 1961.—The oxidative metabolic patterns were determined on 83 strains of brucellae that had been described as “atypical” because they differed in one or more characteristics or because they had been isolated from an abnormal host (other than the natural reservoir for that species). Of the 83 strains examined, 44 displayed the metabolic pattern for Brucella melitensis. A comparison was then made between the results of identifying these strains metabolically and by the conventional methods. It was found that a few strains of B. melitensis showed a decreased tolerance to basic fuchsin and thionin, but none of the strains that was identified metabolically as B. melitensis produced H2S or required CO2. No biotypes have been reported for this species, since only slight quantitative variation in dye tolerances occurs among strains of B. melitensis, and no metabolic variants were found. It is concluded that B. melitensis is a homogenous species and can be identified with certainty by its oxidative metabolic pattern, irrespective of its host or geographic source. Of the remaining strains, 38 displayed the metabolic pattern singular for Brucella abortus. Evidence was presented to support the conclusion that in this species the characteristics of dye tolerance, H2S production, and CO2 required for initial growth vary independently of each other, and strains that differ from the species description by these criteria can be identified correctly by their oxidative metabolic pattern. Of the 83 atypical strains examined, 24 were strains of Brucella described as a new species, Brucella intermedia (Renoux). Of these 24 strains, 10 were identified as Brucella melitensis, 13 as Brucella abortus, and one as Brucella suis. Evidence was
Fifty years ago, bacteria in the genus Brucella were known to cause infertility and reproductive losses. The genus was considered to contain only three species, B. abortus, B. melitensis and B. suis. Since the early 1960’s, at least seven new species have been identified as belonging to the Brucell...
Chain, Patrick S. G.; Comerci, Diego J.; Tolmasky, Marcelo E.; Larimer, Frank W; Malfatti, Stephanie; Vergez, Lisa; Aguero, Fernan; Land, Miriam L; Ugalde, Rodolfo A.; Garcia, Emilio
Despite their high DNA identity and a proposal to group classical Brucella species as biovars of Brucella melitensis, the commonly recognized Brucella species can be distinguished by distinct biochemical and fatty acid characters, as well as by a marked host range (e.g., Brucella suis for swine, B. melitensis for sheep and goats, and Brucella abortus for cattle). Here we present the genome of B. abortus 2308, the virulent prototype biovar 1 strain, and its comparison to the two other human pathogenic Brucella species and to B. abortus field isolate 9-941. The global distribution of pseudogenes, deletions, and insertions supports previous indications that B. abortus and B. melitensis share a common ancestor that diverged from B. suis. With the exception of a dozen genes, the genetic complements of both B. abortus strains are identical, whereas the three species differ in gene content and pseudogenes. The pattern of species-specific gene inactivations affecting transcriptional regulators and outer membrane proteins suggests that these inactivations may play an important role in the establishment of host specificity and may have been a primary driver of speciation in the genus Brucella. Despite being nonmotile, the brucellae contain flagellum gene clusters and display species-specific flagellar gene inactivations, which lead to the putative generation of different versions of flagellum-derived structures and may contribute to differences in host specificity and virulence. Metabolic changes such as the lack of complete metabolic pathways for the synthesis of numerous compounds (e.g., glycogen, biotin, NAD, and choline) are consistent with adaptation of brucellae to an intracellular life-style.
Jumas-Bilak, E; Michaux-Charachon, S; Bourg, G; O'Callaghan, D; Ramuz, M
We have studied the genomic structure and constructed the SpeI, PacI and I-CeuI restriction maps of the four biovars of the pathogenic bacterium Brucella suis. B. suis biovar 1 has two chromosomes of 2.1 Mb and 1.15 Mb, similar to those of the other Brucella species: B. melitensis, B. abortus, B. ovis and B. neotomae. Two chromosomes were also observed in the genome of B. suis biovars 2 and 4, but with sizes of 1.85 Mb and 1.35 Mb, whereas only one chromosome with a size of 3.1 Mb was found in B. suis biovar 3. We show that the differences in chromosome size and number can be explained by rearrangements at chromosomal regions containing the three rrn genes. The location and orientation of these genes confirmed that these rearrangements are due to homologous recombination at the rrn loci. This observation allows us to propose a scheme for the evolution of the genus Brucella in which the two chromosome-containing strains can emerge from an hypothetical ancestor with a single chromosome, which is probably similar to that of B. suis biovar 3. As the genus Brucella is certainly monospecific, this is the first time that differences in chromosome number have been observed in strains of the same bacterial species.
Hoelzle, Ludwig E; Zeder, Michael; Felder, Kathrin M; Hoelzle, Katharina
Mycoplasma suis is an uncultivable bacterium lacking a cell wall that attaches to and may invade the red blood cells of pigs. M. suis infections occur worldwide and cause the pig industry serious economic losses due to the disease known as infectious anaemia of pigs or, historically, porcine eperythrozoonosis. Infectious anaemia of pigs is characterised predominantly by acute haemolytic or chronic anaemia, along with non-specific manifestations, such as growth retardation in feeder pigs and poor reproductive performance in sows. The fastidious nature of M. suis, as well as the lack of an in vitro cultivation system, has hampered the understanding of the biology and pathogenicity of this organism. Pathogenetic mechanisms of M. suis include direct destruction of red blood cells by adhesion, invasion, nutrient scavenging, immune-mediated lysis and eryptosis, as well as endothelial targeting. Recently published genome sequences, in combination with proteome analyses, have generated new insights into the pathogenicity of M. suis. The present review combines these data with the knowledge provided by experimental M. suis infections.
Nymo, Ingebjørg H.; Arias, Maykel A.; Pardo, Julián; Álvarez, María Pilar; Alcaraz, Ana; Godfroid, Jacques; Jiménez de Bagüés, María Pilar
Brucellosis is a zoonosis of worldwide distribution with numerous animal host species. Since the novel isolation of Brucella spp. from marine mammals in 1994 the bacteria have been isolated from various marine mammal hosts. The marine mammal reference strains Brucella pinnipedialis 12890 (harbour seal, Phoca vitulina) and Brucella ceti 12891 (harbour porpoise, Phocoena phocoena) were included in genus Brucella in 2007, however, their pathogenicity in the mouse model is pending. Herein this is evaluated in BALB/c mice with Brucella suis 1330 as a control. Both marine mammal strains were attenuated, however, B. ceti was present at higher levels than B. pinnipedialis in blood, spleen and liver throughout the infection, in addition B. suis and B. ceti were isolated from brains and faeces at times with high levels of bacteraemia. In B. suis-infected mice serum cytokines peaked at day 7. In B. pinnipedialis-infected mice, levels were similar, but peaked predominantly at day 3 and an earlier peak in spleen weight likewise implied an earlier response. The inflammatory response induced pathology in the spleen and liver. In B. ceti-infected mice, most serum cytokine levels were comparable to those in uninfected mice, consistent with a limited inflammatory response, which also was indicated by restricted spleen and liver pathology. Specific immune responses against all three strains were detected in vitro after stimulation of splenocytes from infected mice with the homologous heat-killed brucellae. Antibody responses in vivo were also induced by the three brucellae. The immunological pattern of B. ceti in combination with persistence in organs and limited pathology has heretofore not been described for other brucellae. These two marine mammal wildtype strains show an attenuated pattern in BALB/c mice only previously described for Brucella neotomea. PMID:26959235
Nymo, Ingebjørg H; Arias, Maykel A; Pardo, Julián; Álvarez, María Pilar; Alcaraz, Ana; Godfroid, Jacques; Jiménez de Bagüés, María Pilar
Brucellosis is a zoonosis of worldwide distribution with numerous animal host species. Since the novel isolation of Brucella spp. from marine mammals in 1994 the bacteria have been isolated from various marine mammal hosts. The marine mammal reference strains Brucella pinnipedialis 12890 (harbour seal, Phoca vitulina) and Brucella ceti 12891 (harbour porpoise, Phocoena phocoena) were included in genus Brucella in 2007, however, their pathogenicity in the mouse model is pending. Herein this is evaluated in BALB/c mice with Brucella suis 1330 as a control. Both marine mammal strains were attenuated, however, B. ceti was present at higher levels than B. pinnipedialis in blood, spleen and liver throughout the infection, in addition B. suis and B. ceti were isolated from brains and faeces at times with high levels of bacteraemia. In B. suis-infected mice serum cytokines peaked at day 7. In B. pinnipedialis-infected mice, levels were similar, but peaked predominantly at day 3 and an earlier peak in spleen weight likewise implied an earlier response. The inflammatory response induced pathology in the spleen and liver. In B. ceti-infected mice, most serum cytokine levels were comparable to those in uninfected mice, consistent with a limited inflammatory response, which also was indicated by restricted spleen and liver pathology. Specific immune responses against all three strains were detected in vitro after stimulation of splenocytes from infected mice with the homologous heat-killed brucellae. Antibody responses in vivo were also induced by the three brucellae. The immunological pattern of B. ceti in combination with persistence in organs and limited pathology has heretofore not been described for other brucellae. These two marine mammal wildtype strains show an attenuated pattern in BALB/c mice only previously described for Brucella neotomea.
Tiller, Rebekah V; Gee, Jay E; Frace, Michael A; Taylor, Trevor K; Setubal, Joao C; Hoffmaster, Alex R; De, Barun K
We report on the characterization of a group of seven novel Brucella strains isolated in 1964 from three native rodent species in North Queensland, Australia, during a survey of wild animals. The strains were initially reported to be Brucella suis biovar 3 on the basis of microbiological test results. Our results indicated that the rodent strains had microbiological traits distinct from those of B. suis biovar 3 and all other Brucella spp. To reinvestigate these rodent strains, we sequenced the 16S rRNA, recA, and rpoB genes and nine housekeeping genes and also performed multiple-locus variable-number tandem-repeat (VNTR) analysis (MLVA). The rodent strains have a unique 16S rRNA gene sequence compared to the sequences of the classical Brucella spp. Sequence analysis of the recA, rpoB, and nine housekeeping genes reveals that the rodent strains are genetically identical to each other at these loci and divergent from any of the currently described Brucella sequence types. However, all seven of the rodent strains do exhibit distinctive allelic MLVA profiles, although none demonstrated an amplicon for VNTR 07, whereas the other Brucella spp. did. Phylogenetic analysis of the MLVA data reveals that the rodent strains form a distinct clade separate from the classical Brucella spp. Furthermore, whole-genome sequence comparison using the maximal unique exact matches index (MUMi) demonstrated a high degree of relatedness of one of the seven rodent Brucella strains (strain NF 2653) to another Australian rodent Brucella strain (strain 83-13). Our findings strongly suggest that this group of Brucella strains isolated from wild Australian rodents defines a new species in the Brucella genus.
Feng, Youjun; Zhang, Huimin; Wu, Zuowei; Wang, Shihua; Cao, Min; Hu, Dan; Wang, Changjun
Streptococcus suis (S. suis) is a family of pathogenic gram-positive bacterial strains that represents a primary health problem in the swine industry worldwide. S. suis is also an emerging zoonotic pathogen that causes severe human infections clinically featuring with varied diseases/syndromes (such as meningitis, septicemia, and arthritis). Over the past few decades, continued efforts have made significant progress toward better understanding this zoonotic infectious entity, contributing in part to the elucidation of the molecular mechanism underlying its high pathogenicity. This review is aimed at presenting an updated overview of this pathogen from the perspective of molecular epidemiology, clinical diagnosis and typing, virulence mechanism, and protective antigens contributing to its zoonosis. PMID:24667807
Brucella is a Gram-negative, facultative intracellular bacterium that causes zoonotic brucellosis in humans and various animals. Out of 10 classified Brucella species, B. melitensis, B. abortus, B. suis, and B. canis are pathogenic to humans. In the past decade, the mechanisms of Brucella pathogenesis and host immunity have been extensively investigated using the cutting edge systems biology and bioinformatics approaches. This article provides a comprehensive review of the applications of Omics (including genomics, transcriptomics, and proteomics) and bioinformatics technologies for the analysis of Brucella pathogenesis, host immune responses, and vaccine targets. Based on more than 30 sequenced Brucella genomes, comparative genomics is able to identify gene variations among Brucella strains that help to explain host specificity and virulence differences among Brucella species. Diverse transcriptomics and proteomics gene expression studies have been conducted to analyze gene expression profiles of wild type Brucella strains and mutants under different laboratory conditions. High throughput Omics analyses of host responses to infections with virulent or attenuated Brucella strains have been focused on responses by mouse and cattle macrophages, bovine trophoblastic cells, mouse and boar splenocytes, and ram buffy coat. Differential serum responses in humans and rams to Brucella infections have been analyzed using high throughput serum antibody screening technology. The Vaxign reverse vaccinology has been used to predict many Brucella vaccine targets. More than 180 Brucella virulence factors and their gene interaction networks have been identified using advanced literature mining methods. The recent development of community-based Vaccine Ontology and Brucellosis Ontology provides an efficient way for Brucella data integration, exchange, and computer-assisted automated reasoning. PMID:22919594
Brucella is a Gram-negative, facultative intracellular bacterium that causes zoonotic brucellosis in humans and various animals. Out of 10 classified Brucella species, B. melitensis, B. abortus, B. suis, and B. canis are pathogenic to humans. In the past decade, the mechanisms of Brucella pathogenesis and host immunity have been extensively investigated using the cutting edge systems biology and bioinformatics approaches. This article provides a comprehensive review of the applications of Omics (including genomics, transcriptomics, and proteomics) and bioinformatics technologies for the analysis of Brucella pathogenesis, host immune responses, and vaccine targets. Based on more than 30 sequenced Brucella genomes, comparative genomics is able to identify gene variations among Brucella strains that help to explain host specificity and virulence differences among Brucella species. Diverse transcriptomics and proteomics gene expression studies have been conducted to analyze gene expression profiles of wild type Brucella strains and mutants under different laboratory conditions. High throughput Omics analyses of host responses to infections with virulent or attenuated Brucella strains have been focused on responses by mouse and cattle macrophages, bovine trophoblastic cells, mouse and boar splenocytes, and ram buffy coat. Differential serum responses in humans and rams to Brucella infections have been analyzed using high throughput serum antibody screening technology. The Vaxign reverse vaccinology has been used to predict many Brucella vaccine targets. More than 180 Brucella virulence factors and their gene interaction networks have been identified using advanced literature mining methods. The recent development of community-based Vaccine Ontology and Brucellosis Ontology provides an efficient way for Brucella data integration, exchange, and computer-assisted automated reasoning.
Audic, Stéphane; Lescot, Magali; Claverie, Jean-Michel; Scholz, Holger C
Background Using a combination of pyrosequencing and conventional Sanger sequencing, the complete genome sequence of the recently described novel Brucella species, Brucella microti, was determined. B. microti is a member of the genus Brucella within the Alphaproteobacteria, which consists of medically important highly pathogenic facultative intracellular bacteria. In contrast to all other Brucella species, B. microti is a fast growing and biochemically very active microorganism with a phenotype more similar to that of Ochrobactrum, a facultative human pathogen. The atypical phenotype of B. microti prompted us to look for genomic differences compared to other Brucella species and to look for similarities with Ochrobactrum. Results The genome is composed of two circular chromosomes of 2,117,050 and 1,220,319 base pairs. Unexpectedly, we found that the genome sequence of B. microti is almost identical to that of Brucella suis 1330 with an overall sequence identity of 99.84% in aligned regions. The most significant structural difference between the two genomes is a bacteriophage-related 11,742 base pairs insert only present in B. microti. However, this insert is unlikely to have any phenotypical consequence. Only four protein coding genes are shared between B. microti and Ochrobactrum anthropi but impaired in other sequenced Brucella. The most noticeable difference between B. microti and other Brucella species was found in the sequence of the 23S ribosomal RNA gene. This unusual variation could have pleiotropic effects and explain the fast growth of B. microti. Conclusion Contrary to expectations from the phenotypic analysis, the genome sequence of B. microti is highly similar to that of known Brucella species, and is remotely related to the one of O. anthropi. How the few differences in gene content between B. microti and B. suis 1330 could result in vastly different phenotypes remains to be elucidated. This unexpected finding will complicate the task of identifying
McGhee, J R; Freeman, B A
Soluble precipitating antigens of Brucella suis have been, in various degrees, purified by filtration on Sephadex gels. The most useful gels employed were Sephadex G-150, Sephadex G-200, and Sepharose 4B. Although not all fractions proved to be immunologically pure, some crude molecular-size estimates of most of the 13 soluble antigens of the Brucella cell could be given. In addition, monospecific antisera to three purified Brucella antigens have been prepared. By using purified preparations, physical and chemical data were obtained on two major antigens, E and 1, and a minor antigen, f. Antigen E is not an agglutinogen and may be toxic. Antigen 1 is of low molecular weight and is neither toxic nor agglutinogenic. The minor antigen f is an agglutinogen as well as a precipitinogen and is found on the cell surface. Both major antigens, when purified, were immunogenic in rabbits.
cattle, sheep, goats , dogs, and camels. Important species of Brucella are: suis, abortus, ovis, melitensis , canis, and neotomae, each with certain...B. abortus is strain 19 and for protecting goats against B. melitensis is strain Rev 1. Vaccination with these strains leads to seroconversion...encoding the C-terminus portion of the Brucella protein. Western blot analysis of B. abortus and B. melitensis was performed using antibodies raised against
Ocampo-Sosa, Alain A; García-Lobo, Juan M
Background The Brucella genome contains an insertion sequence (IS) element called IS711 or IS6501, which is specific to the genus. The copy number of IS711 varies in the genome of the different Brucella species, ranging from 7 in B. abortus, B. melitensis and B. suis to more than 30 in B. ovis and in Brucella strains isolated from marine mammals. At present, there is no experimental evidence of transposition of IS711, but the occurrence of this element with a high copy number in some species, and the isolation of Brucella strains with "ectopic" copies of IS711 suggested that this IS could still transpose. Results In this study we obtained evidence of transposition of IS711 from the B. ovis and B. pinnipedialis chromosomes by using the "transposon trap" plasmid pGBG1. This plasmid expresses resistance to tetracycline only if the repressor gene that it contains is inactivated. The strains B. melitensis 16 M, B. abortus RB51, B. ovis BOC22 (field strain) and B. pinnipedialis B2/94, all containing the plasmid pGBG1, were grown in culture media with tetracycline until the appearance of tetracycline resistant mutants (TcR). TcR mutants due to IS711 transposition were only detected in B. ovis and B. pinnipedialis strains. Conclusion Four different copies of IS711 were found to transpose to the same target sequence in the plasmid pGBG1. This demonstrated that IS711 are active in vivo, specially in Brucella species with a high number of IS711 copies as B. ovis and B. pinnipedialis. PMID:18218072
Ali, Shahzad; Ali, Qurban; Melzer, Falk; Khan, Iahtasham; Akhter, Shamim; Neubauer, Heinrich; Jamal, Syed M
Brucellosis is endemic in bovines in Pakistan. The Brucella species and biovars involved, however, are unknown. The objectives of the present study were to isolate and characterize brucellae from seropositive milk samples, aborted fetuses, and vaginal swabs of cattle and buffaloes which had recently aborted. The seropositive milk samples, aborted fetuses, and vaginal swabs of cattle and buffaloes were collected from the Potohar Plateau, Pakistan. Isolation of brucellae was done on modified Farrell's serum dextrose agar. Isolates were characterized by conventional biotyping methods, while molecular typing was done by genus (B4/B5) and species-specific (Brucella abortus, Brucella melitensis, Brucella ovis, and Brucella suis) polymerase chain reaction (PCR). A total of 30 isolates were recovered from milk (n = 5), aborted fetuses (n = 13), and vaginal swabs (n = 12). Most isolates were from cattle (56.7 %). All of them were identified as B. abortus biovar 1 based on conventional biotyping methods and genus and species-specific PCR. This preliminary study provides the first report on the prevalence of B. abortus biovar 1 in cattle and buffaloes in Pakistan.
Whatmore, Adrian M; Perrett, Lorraine L; MacMillan, Alastair P
Background Brucella species include economically important zoonotic pathogens that can infect a wide range of animals. There are currently six classically recognised species of Brucella although, as yet unnamed, isolates from various marine mammal species have been reported. In order to investigate genetic relationships within the group and identify potential diagnostic markers we have sequenced multiple genetic loci from a large sample of Brucella isolates representing the known diversity of the genus. Results Nine discrete genomic loci corresponding to 4,396 bp of sequence were examined from 160 Brucella isolates. By assigning each distinct allele at a locus an arbitrary numerical designation the population was found to represent 27 distinct sequence types (STs). Diversity at each locus ranged from 1.03–2.45% while overall genetic diversity equated to 1.5%. Most loci examined represent housekeeping gene loci and, in all but one case, the ratio of non-synonymous to synonymous change was substantially <1. Analysis of linkage equilibrium between loci indicated a strongly clonal overall population structure. Concatenated sequence data were used to construct an unrooted neighbour-joining tree representing the relationships between STs. This shows that four previously characterized classical Brucella species, B. abortus, B. melitensis, B. ovis and B. neotomae correspond to well-separated clusters. With the exception of biovar 5, B. suis isolates cluster together, although they form a more diverse group than other classical species with a number of distinct STs corresponding to the remaining four biovars. B. canis isolates are located on the same branch very closely related to, but distinguishable from, B. suis biovar 3 and 4 isolates. Marine mammal isolates represent a distinct, though rather weakly supported, cluster within which individual STs display one of three clear host preferences. Conclusion The sequence database provides a powerful dataset for addressing
MacInnes, J I; Desrosiers, R
In recent years, Actinobacillus suis, Haemophilus parasuis, and Streptococcus suis have emerged as important pathogens of swine, particularly in high health status herds. Their association with a wide range of serious clinical conditions and has given rise to the moniker "suis-ide diseases." These organisms are early colonizers and, for that reason, are difficult to control by management procedures such as segregated early weaning. Vaccination, serodiagnostic testing, and even serotyping are complicated by the presence of multiple serotypes, cross-reactive antigens, and the absence of clear markers for virulence. In this review, we discuss our current understanding of the pathogenesis, epidemiology, and management of the causative agents of the "suis-ide diseases" of swine. Images Figure 1. Figure 2. Figure 3. PMID:10369563
Nymo, Ingebjørg Helena; Beckmen, Kimberlee; Godfroid, Jacques
We used an indirect enzyme-linked immunosorbent assay (iELISA) and the rose bengal test (RBT) to test for anti-Brucella antibodies in moose (Alces alces gigas), muskoxen (Ovibos moschatus), and plains bison (Bison bison bison) from various game management units (GMUs) in Alaska, US, sampled from 1982 to 2010. A portion of the sera had previously been tested with the standard plate test (SPT), the buffered Brucella antigen (BBA) card test, and the card test (CARD). No antibody-positive plains bison were identified. Anti-Brucella antibodies were detected in moose (iELISA, n=4/87; RBT, n=4/87; SPT, n=4/5; BBA, n=4/4) from GMU 23 captured in 1992, 1993, and 1995 and in muskoxen (iELISA, n=4/52; RBT, n=4/52; CARD, n=4/35) from GMUs 26A and 26B captured in 2004, 2006, and 2007. A negative effect of infection on the health of individuals of these species is probable. The presence of antibody-positive animals from 1992 to 2007 suggests presence of brucellae over time. The antibody-positive animals were found in northern Alaska, an area with a historically higher prevalence of Brucella-positive caribou, and a spillover of Brucella suis biovar 4 from caribou may have occurred. Brucella suis biovar 4 causes human brucellosis, and transmission from consumption of moose and muskoxen is possible.
Salhi, Imed; Boigegrain, Rose-Anne; Machold, Jan; Weise, Christoph; Cloeckaert, Axel; Rouot, Bruno
Impairment of the omp25 gene in Brucella spp. leads to attenuated strains and confers protection to the host. Omp25 and Omp31, whose functions remain unknown, were the first characterized members of group 3 outer membrane proteins (Omps) (25 to 34 kDa). Recently, genomic and proteomic approaches identified five new putative members of this family, some of which are produced in B. melitensis or B. abortus. In the present study, using protein microsequencing, we identified new members of group 3 Omps proteins produced in B. suis. Since several monoclonal antibodies (MAbs) against Omp25 cross-reacted with other members of group 3 Omps, we also performed Western immunoblotting to compare wild-type B. suis with mutants systematically having B. suis omp25-related genes knocked out. We demonstrate the production of three paralogs of Omp31 and/or Omp25 in B. suis, and the existence of a common site of signal peptide cleavage (AXAAD), which is very similar to that present in the five homologous Omps of Bartonella quintana. The seven group 3 Omps were classified in four-subgroups on the basis of percentage amino acid sequence identities: Omp25 alone, the Omp25b-Omp25c-Omp25d cluster, the Omp31/31b subgroup, and the less related Omp22 protein (also called Omp3b). Together with previous data, our results demonstrate that all new members of group 3 Omps are produced in B. suis or in other Brucella species and we propose a nomenclature that integrates all of these proteins to facilitate the understanding of future Brucella interspecies study results. PMID:12874309
Rittig, Michael G.; Alvarez-Martinez, Maria-Teresa; Porte, Françoise; Liautard, Jean-Pierre; Rouot, Bruno
Brucella spp. are facultative intracellular parasites of various mammals, including humans, typically infecting lymphoid as well as reproductive organs. We have investigated how B. suis and B. melitensis enter human monocytes and in which compartment they survive. Peripheral blood monocytes readily internalized nonopsonized brucellae and killed most of them within 12 to 18 h. The presence of Brucella-specific antibodies (but not complement) increased the uptake of bacteria without increasing their intracellular survival, whereas adherence of the monocytes or incubation in Ca2+- and Mg2+-free medium reduced the uptake. Engulfment of all Brucella organisms (regardless of bacterial viability or virulence) initially resulted in phagosomes with tightly apposed walls (TP). Most TP were fully fusiogenic and matured to spacious phagolysosomes containing degraded bacteria, whereas some TP (more in monocyte-derived macrophages, HeLa cells, and CHO cells than in monocytes) remained tightly apposed to intact bacteria. Immediate treatment of infected host cells with the lysosomotropic base ammonium chloride caused a swelling of all phagosomes and a rise in the intraphagosomal pH, abolishing the intracellular survival of Brucella. These results indicate that (i) human monocytes readily internalize Brucella in a conventional way using various phagocytosis-promoting receptors, (ii) the maturation of some Brucella phagosomes is passively arrested between the steps of acidification and phagosome-lysosome fusion, (iii) brucellae are killed in maturing but not in arrested phagosomes, and (iv) survival of internalized Brucella depends on an acidic intraphagosomal pH and/or close contact with the phagosomal wall. PMID:11349069
The genus Brucella is a member of family Brucellaceae and includes ten species which are small, non-motile, non-sporing, aerobic, gram-negative intracellular coccobacilli. They are catalase, oxidase and urea positive bacteria. Members of the genus can grow on enriched media like blood agar or chocolate agar. Identification in species level can be done by agglutination with monospecific serum, cultivating the strains in the presence of dyes and/or with PCR methods. Antigenic structure of the Brucella is composed of surface, intracellular, and in vivo antigens. Thanks to various virulence factors that act as metabolic regulators, Brucella strains can protect themselves from immune system of the host, adapt easily to different environmental conditions, and multiply intracellular. Classification, epidemiological features, isolation and identification, antigenic structure and virulence factors of Brucella species along with the discussion of very few patents associated with Brucellosis have been reviewed in this paper.
Lucero, N E; Ayala, S M; Escobar, G I; Jacob, N R
We report a retrospective analysis of 1933 Brucella strains isolated from humans and animals in Latin American countries between 1968 and 1991 and in Argentina between 1994 and 2006. During the first period 50% of strains were from humans, mainly from Argentina, Mexico and Peru but, while B. suis was the main cause of infection in Argentina, B. melitensis was responsible for most infections in the other countries. In Argentina in the later years, B. melitensis and B. suis were observed more frequently than in the first period while isolation of B. abortus decreased. Of 145 B. melitensis human isolates, eight gave susceptibility patterns to dyes and penicillin and two were B. melitensis biovar 3, which has never been reported in animals. Forty-six percent of B. suis isolated were resistant to dyes which is an atypical feature in this species.
Cardoso, Patrícia Gomes; Macedo, Gilson Costa; Azevedo, Vasco; Oliveira, Sergio Costa
Brucella spp. are facultative intracellular pathogens that have the ability to survive and multiply in professional and non-professional phagocytes, and cause abortion in domestic animals and undulant fever in humans. Several species are recognized within the genus Brucella and this classification is mainly based on the difference in pathogenicity and in host preference. Brucella strains may occur as either smooth or rough, expressing smooth LPS (S-LPS) or rough LPS (R-LPS) as major surface antigen. This bacterium possesses an unconventional non-endotoxic lipopolysaccharide that confers resistance to anti-microbial attacks and modulates the host immune response. The strains that are pathogenic for humans (B. abortus, B. suis, B. melitensis) carry a smooth LPS involved in the virulence of these bacteria. The LPS O-chain protects the bacteria from cellular cationic peptides, oxygen metabolites and complement-mediated lysis and it is a key molecule for Brucella survival and replication in the host. Here, we review i) Brucella LPS structure; ii) Brucella genome, iii) genes involved in LPS biosynthesis; iv) the interaction between LPS and innate immunity.
Szulowski, K; Iwaniak, W; Pilaszek, J; Truszczyński, M; Chrobocińska, M
Hare brucellosis is caused primarily by Brucella suis biovar 2. Hares along with wild boars are the natural reservoir of this microorganism. In view of restriction of applicability of traditional serological methods the work aimed to develop the ELISA to examine hare sera for the presence of anti-Brucella antibodies. Lipopolysaccharide (LPS) antigen obtained from the strain S19 of Brucella abortus and the conjugate of antibodies against rabbit immunoglobulin with horseradish peroxidase were used in the test. Hares' sera positive and negative in the CFT were used as controls of the ELISA. The sera collected from 9 hares suspected to be infected with Brucella organisms, positive in CFT (in this number 7 hares revealed clinical symptoms or anathomopathological lesions characteristic of brucellosis), 6 sera from hares showing no symptoms of the disease, negative in CFT and 520 sera from hares monitored for brucellosis were tested. All serum samples from hares suspected for Brucella infection were positive in ELISA and 2 of them were negative in RBPT. Additionally among the samples from hares monitored 12 sera were positive in ELISA and CFT, whereas 9 sera from 12 ones were also positive in the RBPT. The obtained results indicated that the ELISA developed in our laboratory proved to be equivalent in specificity to CFT. In addition, ELISA proved to be more sensitive than RBPT for the diagnosis of Brucella infection in hares.
Fernández-Lago, Luis; Vallejo, F. Javier; Trujillano, Ignacio; Vizcaíno, Nieves
A whole-cell hybridization assay with fluorescent oligonucleotide probes derived from the 16S rRNA sequence of Brucella abortus in combination with flow cytometry has been developed. With the three fluorescent probes selected, a positive signal was observed with all the representative strains of the species and biovars of Brucella and with a total of nine different Brucella clinical isolates. Using the B9 probe in the hybridization assay, it was possible to discriminate between Brucella suis biovars 2, 3, 4, and 5 and almost all the other Brucella spp. On the basis of differences in fluorescence intensities, no discrimination was established between Brucella spp. and other phylogenetically related microorganisms. No positive fluorescence signals were detected with any of the bacteria showing serological cross-reactions with Brucella spp. and with a total of 17 clinical isolates not belonging to the genus Brucella. These results suggest that the 16S rRNA whole-cell hybridization technique could be a valuable diagnostic tool for the detection and identification of Brucella spp. PMID:10878084
Chain, P; Comerci, D; Tolmasky, M; Larimer, F; Malfatti, S; Vergez, L; Aguero, F; Land, M; Ugalde, R; Garcia, E
Despite their high DNA identity and a proposal to group classical Brucella species as biovars of B. melitensis, the commonly recognized Brucella species can be distinguished by distinct biochemical and fatty acid characters as well as by a marked host range (e.g. B. suis for swine, B. melitensis for sheep and goats, B. abortus for cattle). Here we present the genome of B. abortus 2308, the virulent prototype biovar 1 strain, and its comparison to the two other human pathogenic Brucellae species and to the B. abortus field isolate 9-941. The global distribution of pseudogenes, deletions and insertions support previous indications that B. abortus and B. melitensis share a common ancestor that diverged from B. suis. With the exception of a dozen genes, the genetic complement of both B. abortus strains is identical, whereas the three species differ in gene content and pseudogenes. The pattern of species-specific gene inactivations affecting transcriptional regulators and outer membrane proteins suggest that these inactivations may play an important role in the establishment of host-specificity and may have been a primary driver of speciation in the Brucellae. Despite being non-motile, the Brucellae contain flagellum gene clusters and display species-specific flagellar gene inactivations, which lead to the putative generation of different versions of flagellum-derived structures, and may contribute to differences in host-specificity and virulence. Metabolic changes such as the lack of complete metabolic pathways for the synthesis of numerous compounds (e.g. glycogen, biotin, NAD, and choline) are consistent with adaptation of Brucellae to an intracellular lifestyle.
Jensen, Allen E; Halling, Shirley M
Brucella are resistant to polymyxin B (PB), but their relative susceptibility to PB and its derivative, colistin (COL) has not been rigorously or systematically studied. Comparative susceptibility of Brucella reference strains, vaccine strain RB51, and Brucella isolates from marine mammals to these two cationic peptides were determined by Etest. Vast differences among Brucella species were found in susceptibility to both PB and COL. Brucella demonstrated similar pattern of relative susceptibility to PB as that of COL, but they were less susceptible to COL. Both B. melitensis and B. suis were the least susceptible to polymyxins and rough strains were more susceptible to both PB and COL than the smooth except for the BvrR mutant. Strains were generally less susceptible to PB when cultured in CO(2) rather than ambient air; some became more susceptible in acidified medium. Results show that environment cultural conditions must be considered when selecting for CO(2)-independent strains of Brucella especially the vaccine strain RB51 on selective media containing PB. Our observations extend basic knowledge of the differential resistance of Brucella to polymyxins.
Ronneau, Severin; Moussa, Simon; Barbier, Thibault; Conde-Álvarez, Raquel; Zuniga-Ripa, Amaia; Moriyon, Ignacio; Letesson, Jean-Jacques
The brucellae are α-Proteobacteria causing brucellosis, an important zoonosis. Although multiplying in endoplasmic reticulum-derived vacuoles, they cause no cell death, suggesting subtle but efficient use of host resources. Brucellae are amino-acid prototrophs able to grow with ammonium or use glutamate as the sole carbon-nitrogen source in vitro. They contain more than twice amino acid/peptide/polyamine uptake genes than the amino-acid auxotroph Legionella pneumophila, which multiplies in a similar vacuole, suggesting a different nutritional strategy. During these two last decades, many mutants of key actors in nitrogen metabolism (transporters, enzymes, regulators, etc.) have been described to be essential for full virulence of brucellae. Here, we review the genomic and experimental data on Brucella nitrogen metabolism and its connection with virulence. An analysis of various aspects of this metabolism (transport, assimilation, biosynthesis, catabolism, respiration and regulation) has highlighted differences and similarities in nitrogen metabolism with other α-Proteobacteria. Together, these data suggest that, during their intracellular life cycle, the brucellae use various nitrogen sources for biosynthesis, catabolism and respiration following a strategy that requires prototrophy and a tight regulation of nitrogen use.
Baldi, Pablo C; Giambartolomei, Guillermo H
In spite of the protean nature of the disease, inflammation is a hallmark of brucellosis and affected tissues usually exhibit inflammatory infiltrates. As Brucella lacks exotoxins, exoproteases or cytolysins, pathological findings in brucellosis probably arise from inflammation-driven processes. The cellular and molecular bases of immunopathological phenomena probably involved in Brucella pathogenesis have been unraveled in the last few years. Brucella-infected osteoblasts, either alone or in synergy with infected macrophages, produce cytokines, chemokines and matrixmetalloproteinases (MMPs), and similar phenomena are mounted by fibroblast-like synoviocytes. The released cytokines promote the secretion of MMPs and induce osteoclastogenesis. Altogether, these phenomena may contribute to the bone loss and cartilage degradation usually observed in brucellar arthritis and osteomyelitis. Proinflammatory cytokines may be also involved in the pathogenesis of neurobrucellosis. B. abortus and its lipoproteins elicit an inflammatory response in the CNS of mice, leading to astrogliosis, a characteristic feature of neurobrucellosis. Heat-killed bacteria (HKBA) and the L-Omp19 lipoprotein elicit astrocyte apoptosis and proliferation (two features of astrogliosis), and apoptosis depends on TNF-α signaling. Brucella also infects and replicates in human endothelial cells, inducing the production of chemokines and IL-6, and an increased expression of adhesion molecules. The sustained inflammatory process derived from the longlasting infection of the endothelium may be important for the development of endocarditis. Therefore, while Brucella induces a low grade inflammation as compared to other pathogens, its prolonged intracellular persistence in infected tissues supports a long-lasting inflammatory response that mediates different pathways of tissue damage. In this context, approaches to avoid the invasion of host cells or limit the intracellular survival of the bacterium may be
Abkar, Morteza; Amani, Jafar; Sahebghadam Lotfi, Abbas; Nikbakht Brujeni, Gholamreza; Alamian, Saeed; Kamali, Mehdi
Brucellosis is a world prevalent endemic illness that is transmitted from domestic animals to humans. Brucella spp. exploits urease for survival in the harsh conditions of stomach during the gastrointestinal infection. In this study, we examined the immune response and the protection elicited by using recombinant Brucella urease (rUrease) vaccination in BALB/c mice. The urease gene was cloned in pET28a and the resulting recombinant protein was employed as subunit vaccine. Recombinant protein was administered subcutaneously and intraperitoneally. Dosage reduction was observed with subcutaneous (SC) vaccination when compared with intraperitoneal (IP) vaccination. rUrease induced mixed Th1-Th2 immune responses with high titers of specific IgG1 and IgG2a. In lymphocyte proliferation assay, splenocytes from IP and SC-vaccinated mice displayed a strong recall proliferative response with high amounts of IL-4, IL-12 and IFN-γ production. Vaccinated mice were challenged with virulent Brucella melitensis, B. abortus and B. suis. The SC vaccination route exhibited a higher degree of protection than IP vaccination (p value ≤ 0.05). Altogether, our results indicated that rUrease could be a useful antigen candidate for the development of subunit vaccines against brucellosis.
Tsolis, Renee M; Seshadri, Rekha; Santos, Renato L; Sangari, Felix J; Lobo, Juan M García; de Jong, Maarten F; Ren, Qinghu; Myers, Garry; Brinkac, Lauren M; Nelson, William C; Deboy, Robert T; Angiuoli, Samuel; Khouri, Hoda; Dimitrov, George; Robinson, Jeffrey R; Mulligan, Stephanie; Walker, Richard L; Elzer, Philip E; Hassan, Karl A; Paulsen, Ian T
Brucella ovis is a veterinary pathogen associated with epididymitis in sheep. Despite its genetic similarity to the zoonotic pathogens B. abortus, B. melitensis and B. suis, B. ovis does not cause zoonotic disease. Genomic analysis of the type strain ATCC25840 revealed a high percentage of pseudogenes and increased numbers of transposable elements compared to the zoonotic Brucella species, suggesting that genome degradation has occurred concomitant with narrowing of the host range of B. ovis. The absence of genomic island 2, encoding functions required for lipopolysaccharide biosynthesis, as well as inactivation of genes encoding urease, nutrient uptake and utilization, and outer membrane proteins may be factors contributing to the avirulence of B. ovis for humans. A 26.5 kb region of B. ovis ATCC25840 Chromosome II was absent from all the sequenced human pathogenic Brucella genomes, but was present in all of 17 B. ovis isolates tested and in three B. ceti isolates, suggesting that this DNA region may be of use for differentiating B. ovis from other Brucella spp. This is the first genomic analysis of a non-zoonotic Brucella species. The results suggest that inactivation of genes involved in nutrient acquisition and utilization, cell envelope structure and urease may have played a role in narrowing of the tissue tropism and host range of B. ovis.
Tsolis, Renee M.; Seshadri, Rekha; Santos, Renato L.; Sangari, Felix J.; Lobo, Juan M. García; de Jong, Maarten F.; Ren, Qinghu; Myers, Garry; Brinkac, Lauren M.; Nelson, William C.; DeBoy, Robert T.; Angiuoli, Samuel; Khouri, Hoda; Dimitrov, George; Robinson, Jeffrey R.; Mulligan, Stephanie; Walker, Richard L.; Elzer, Philip E.; Hassan, Karl A.; Paulsen, Ian T.
Brucella ovis is a veterinary pathogen associated with epididymitis in sheep. Despite its genetic similarity to the zoonotic pathogens B. abortus, B. melitensis and B. suis, B. ovis does not cause zoonotic disease. Genomic analysis of the type strain ATCC25840 revealed a high percentage of pseudogenes and increased numbers of transposable elements compared to the zoonotic Brucella species, suggesting that genome degradation has occurred concomitant with narrowing of the host range of B. ovis. The absence of genomic island 2, encoding functions required for lipopolysaccharide biosynthesis, as well as inactivation of genes encoding urease, nutrient uptake and utilization, and outer membrane proteins may be factors contributing to the avirulence of B. ovis for humans. A 26.5 kb region of B. ovis ATCC25840 Chromosome II was absent from all the sequenced human pathogenic Brucella genomes, but was present in all of 17 B. ovis isolates tested and in three B. ceti isolates, suggesting that this DNA region may be of use for differentiating B. ovis from other Brucella spp. This is the first genomic analysis of a non-zoonotic Brucella species. The results suggest that inactivation of genes involved in nutrient acquisition and utilization, cell envelope structure and urease may have played a role in narrowing of the tissue tropism and host range of B. ovis. PMID:19436743
Zygmunt, Michel S; Jacques, Isabelle; Bernardet, Nelly; Cloeckaert, Axel
Recently, novel Brucella strains with phenotypic characteristics that were atypical for strains belonging to the genus Brucella have been reported. Phenotypically many of these strains were initially misidentified as Ochrobactrum spp. Two novel species have been described so far for these strains, i.e., B. microti and B. inopinata, and other strains genetically related to B. inopinata may constitute other novel species as well. In this study, we analyzed the lipopolysaccharides (LPS) (smooth LPS [S-LPS] and rough LPS [R-LPS]) of these atypical strains using different methods and a panel of monoclonal antibodies (MAbs) directed against several epitopes of the Brucella O-polysaccharide (O-PS) and R-LPS. Among the most striking results, Brucella sp. strain BO2, isolated from a patient with chronic destructive pneumonia, showed a completely distinct S-LPS profile in silver stain gels that looked more similar to that of enterobacterial S-LPS. This strain also failed to react with MAbs against Brucella O-PS epitopes and showed weak reactivity with anti-R-LPS MAbs. B. inopinata reference strain BO1 displayed an M-dominant S-LPS type with some heterogeneity relative to the classical M-dominant Brucella S-LPS type. Australian wild rodent strains belonging also to the B. inopinata group showed a classical A-dominant S-LPS but lacked the O-PS common (C) epitopes, as previously reported for B. suis biovar 2 strains. Interestingly, some strains also failed to react with anti-R-LPS MAbs, such as the B. microti reference strain and B. inopinata BO1, suggesting modifications in the core-lipid A moieties of these strains. These results have several implications for serological typing and serological diagnosis and underline the need for novel tools for detection and correct identification of such novel emerging Brucella spp.
Whatmore, Adrian M; Koylass, Mark S; Muchowski, Jakub; Edwards-Smallbone, James; Gopaul, Krishna K; Perrett, Lorraine L
An extended multilocus sequence analysis (MLSA) scheme applicable to the Brucella, an expanding genus that includes zoonotic pathogens that severely impact animal and human health across large parts of the globe, was developed. The scheme, which extends a previously described nine locus scheme by examining sequences at 21 independent genetic loci in order to increase discriminatory power, was applied to a globally and temporally diverse collection of over 500 isolates representing all 12 known Brucella species providing an expanded and detailed understanding of the population genetic structure of the group. Over 100 sequence types (STs) were identified and analysis of data provided insights into both the global evolutionary history of the genus, suggesting that early emerging Brucella abortus lineages might be confined to Africa while some later lineages have spread worldwide, and further evidence of the existence of lineages with restricted host or geographical ranges. The relationship between biovar, long used as a crude epidemiological marker, and genotype was also examined and showed decreasing congruence in the order Brucella suis > B. abortus > Brucella melitensis. Both the previously described nine locus scheme and the extended 21 locus scheme have been made available at http://pubmlst.org/brucella/ to allow the community to interrogate existing data and compare with newly generated data.
Whatmore, Adrian M.; Koylass, Mark S.; Muchowski, Jakub; Edwards-Smallbone, James; Gopaul, Krishna K.; Perrett, Lorraine L.
An extended multilocus sequence analysis (MLSA) scheme applicable to the Brucella, an expanding genus that includes zoonotic pathogens that severely impact animal and human health across large parts of the globe, was developed. The scheme, which extends a previously described nine locus scheme by examining sequences at 21 independent genetic loci in order to increase discriminatory power, was applied to a globally and temporally diverse collection of over 500 isolates representing all 12 known Brucella species providing an expanded and detailed understanding of the population genetic structure of the group. Over 100 sequence types (STs) were identified and analysis of data provided insights into both the global evolutionary history of the genus, suggesting that early emerging Brucella abortus lineages might be confined to Africa while some later lineages have spread worldwide, and further evidence of the existence of lineages with restricted host or geographical ranges. The relationship between biovar, long used as a crude epidemiological marker, and genotype was also examined and showed decreasing congruence in the order Brucella suis > B. abortus > Brucella melitensis. Both the previously described nine locus scheme and the extended 21 locus scheme have been made available at http://pubmlst.org/brucella/ to allow the community to interrogate existing data and compare with newly generated data. PMID:28066370
Dauphin, Leslie A; Hutchins, Rebecca J; Bost, Liberty A; Bowen, Michael D
This study evaluated automated and manual commercial DNA extraction methods for their ability to recover DNA from Brucella species in phosphate-buffered saline (PBS) suspension and from spiked swab specimens. Six extraction methods, representing several of the methodologies which are commercially available for DNA extraction, as well as representing various throughput capacities, were evaluated: the MagNA Pure Compact and the MagNA Pure LC instruments, the IT 1-2-3 DNA sample purification kit, the MasterPure Complete DNA and RNA purification kit, the QIAamp DNA blood mini kit, and the UltraClean microbial DNA isolation kit. These six extraction methods were performed upon three pathogenic Brucella species: B. abortus, B. melitensis, and B. suis. Viability testing of the DNA extracts indicated that all six extraction methods were efficient at inactivating virulent Brucella spp. Real-time PCR analysis using Brucella genus- and species-specific TaqMan assays revealed that use of the MasterPure kit resulted in superior levels of detection from bacterial suspensions, while the MasterPure kit and MagNA Pure Compact performed equally well for extraction of spiked swab samples. This study demonstrated that DNA extraction methodologies differ in their ability to recover Brucella DNA from PBS bacterial suspensions and from swab specimens and, thus, that the extraction method used for a given type of sample matrix can influence the sensitivity of real-time PCR assays for Brucella.
Menshawy, Ahmed M S; Perez-Sancho, Marta; Garcia-Seco, Teresa; Hosein, Hosein I; García, Nerea; Martinez, Irene; Sayour, Ashraf E; Goyache, Joaquín; Azzam, Ragab A A; Dominguez, Lucas; Alvarez, Julio
Brucellosis is endemic in most parts of Egypt, where it is caused mainly by Brucella melitensis biovar 3, and affects cattle and small ruminants in spite of ongoing efforts devoted to its control. Knowledge of the predominant Brucella species/strains circulating in a region is a prerequisite of a brucellosis control strategy. For this reason a study aiming at the evaluation of the phenotypic and genetic heterogeneity of a panel of 17 Brucella spp. isolates recovered from domestic ruminants (cattle, buffalo, sheep, and goat) from four governorates during a period of five years (2002-2007) was carried out using microbiological tests and molecular biology techniques (PCR, MLVA-15, and sequencing). Thirteen strains were identified as B. melitensis biovar 3 while all phenotypic and genetic techniques classified the remaining isolates as B. abortus (n = 2) and B. suis biovar 1 (n = 2). MLVA-15 yielded a high discriminatory power (h = 0.801), indicating a high genetic diversity among the B. melitensis strains circulating among domestic ruminants in Egypt. This is the first report of the isolation of B. suis from cattle in Egypt which, coupled with the finding of B. abortus, suggests a potential role of livestock as reservoirs of several zoonotic Brucella species in the region.
Nymo, Ingebjørg H; das Neves, Carlos G; Tryland, Morten; Bårdsen, Bård-Jørgen; Santos, Renato Lima; Turchetti, Andreia Pereira; Janczak, Andrew M; Djønne, Berit; Lie, Elisabeth; Berg, Vidar; Godfroid, Jacques
Brucellosis, a worldwide zoonosis, is linked to reproductive problems in primary hosts. A high proportion of Brucella-positive hooded seals (Cystophora cristata) have been detected in the declined Northeast Atlantic stock. High concentrations of polychlorinated biphenyls (PCBs) have also been discovered in top predators in the Arctic, including the hooded seal, PCB 153 being most abundant. The aim of this study was to assess the pathogenicity of Brucella pinnipedialis hooded seal strain in the mouse model and to evaluate the outcome of Brucella spp. infection after exposure of mice to PCB 153. BALB/c mice were infected with B. pinnipedialis hooded seal strain or Brucella suis 1330, and half from each group was exposed to PCB 153 through the diet. B. pinnipedialis showed a reduced pathogenicity in the mouse model as compared to B. suis 1330. Exposure to PCB 153 affected neither the immunological parameters, nor the outcome of the infection. Altogether this indicates that it is unlikely that B. pinnipedialis contribute to the decline of hooded seals in the Northeast Atlantic.
Nucleotide sequence and expression of the gene encoding the major 25-kilodalton outer membrane protein of Brucella ovis: Evidence for antigenic shift, compared with other Brucella species, due to a deletion in the gene.
Cloeckaert, A; Verger, J M; Grayon, M; Zygmunt, M S; Grépinet, O
The nucleotide sequences encoding the major 25-kDa outer membrane protein (OMP) (omp25 genes) of Brucella ovis 63/290, Brucella melitensis 16M, Brucella suis 1330, Brucella canis RM6/66, and Brucella neotomae 5K33 (all reference strains) were determined and compared with that of Brucella abortus 544 (P. de Wergifosse, P. Lintermans, J. N. Limet, and A. Cloeckaert, J. Bacteriol. 177:1911-1914, 1995). The major difference found was between the omp25 gene of B. ovis and those of the other Brucella species; the B. ovis gene had a 36-bp deletion located at the 3' end of the gene. The corresponding regions of other Brucella species contain two 8-bp direct repeats and two 4-bp inverted repeats, which could have been involved in the genesis of the deletion. The mechanism responsible for the genesis of the deletion appears to be related to the "slipped mispairing" mechanism described in the literature. Expression of the 25-kDa outer membrane protein (Omp25) in Brucella spp. or expression from the cloned omp25 gene in Escherichia coli cells was studied with a panel of anti-Omp25 monoclonal antibodies (MAbs). As shown by enzyme-linked immunosorbent assay (ELISA) and immunoelectron microscopy, Omp25 was exported to the outer membrane in E. coli expressing either the truncated omp25 gene of B. ovis or the entire omp25 genes of the other Brucella species. Size and antigenic shifts due to the 36-bp deletion were demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting and by the differences in binding patterns in ELISA of the anti-Omp25 MAbs at the cell surface of E. coli cells harboring the appropriate gene and of cells of B. ovis and other Brucella species. In particular, MAbs directed against discontinuous epitopes of the entire Omp25 showed the absence of, or a significant reduction in, antibody reactivity with the B. ovis truncated Omp25. The results indicated that, as defined by the MAbs, exported Omp25 probably presents similar
De Cooman, L; Houf, K; Smet, A; Flahou, B; Ducatelle, R; De Bruyne, E; Pasmans, F; Haesebrouck, F
Helicobacter (H.) suis is a world-wide spread pathogen which not only colonizes the stomach of pigs, but is also the most prevalent gastric non-H. pylori Helicobacter (NHPH) species in humans. H. suis infections are associated with gastric lesions both in pigs and in humans. Recently, the presence of viable H. suis bacteria has been demonstrated in minced pork, suggesting that manipulation or consumption of contaminated pig meat is a possible route of transmission of this zoonotic agent. The main goal of this study was to determine the extent of pork carcass contamination with H. suis at slaughter. In two consecutive studies, the occurrence of H. suis DNA was assessed in scalding water, head and mouth swabs, mesenteric lymph nodes, palatine tonsils and on the chest, shoulder and ham region of pork carcasses from three slaughterhouses using qPCR with ureA gene based H. suis-specific primers. H. suis DNA was detected on carcasses in all slaughterhouses, in 8.3% of all 1083 samples. It was found in all sampled matrices, except for the palatine tonsils and scalding water samples. Contamination levels of dressed pork samples did not exceed 184 genomic equivalents per 100cm(2) (shoulder, ham) or 300cm(2) (chest). All positive PCR products were subjected to sequence analysis of the ureA gene to confirm the identification of H. suis bacteria. Using multilocus sequence typing (MLST) on a selection of the positive samples, 5 unique sequence types (STs) could be assigned. Multiple H. suis strains were present on samples derived from one specific pig herd. Since H. suis DNA was detected in 11% (n: 90) of the mesenteric lymph nodes derived at the slaughterhouse, it was determined whether these organisms can colonize the mesenteric lymph nodes after experimental infection. Despite high-level colonization of the porcine stomachs with the H. suis strain, no H. suis DNA was detected in the mesenteric lymph nodes at four weeks after experimental infection. This might indicate that
Sankarasubramanian, Jagadesan; Vishnu, Udayakumar S; Khader, L K M Abdul; Sridhar, Jayavel; Gunasekaran, Paramasamy; Rajendhran, Jeyaprakash
Brucella sp. causes a major zoonotic disease, brucellosis. Brucella belongs to the family Brucellaceae under the order Rhizobiales of Alphaproteobacteria. We present BrucellaBase, a web-based platform, providing features of a genome database together with unique analysis tools. We have developed a web version of the multilocus sequence typing (MLST) (Whatmore et al., 2007) and phylogenetic analysis of Brucella spp. BrucellaBase currently contains genome data of 510 Brucella strains along with the user interfaces for BLAST, VFDB, CARD, pairwise genome alignment and MLST typing. Availability of these tools will enable the researchers interested in Brucella to get meaningful information from Brucella genome sequences. BrucellaBase will regularly be updated with new genome sequences, new features along with improvements in genome annotations. BrucellaBase is available online at http://www.dbtbrucellosis.in/brucellabase.html or http://126.96.36.199/brucellabase/homepage.html.
Meikle, P J; Perry, M B; Cherwonogrodzky, J W; Bundle, D R
Brucella A and M epitopes were found on single O-polysaccharide chains of all biotype strains of this species. Lipopolysaccharides from the type and reference strains of five of the six Brucella species, B. abortus, B. melitensis, B. suis, B. canis, and B. neotomae, were extracted and purified. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, in conjunction with silver staining and immunoblotting developed by monoclonal antibodies, showed bands characteristic of A, M, or mixed A and M antigens. The A antigen previously described as an exclusively alpha 1,2-linked homopolymer of 4,6-dideoxy-4-formamido-D-mannopyranose was shown by 1H and 13C nuclear magnetic resonance spectroscopy to possess a fine structure consistent with the low-frequency occurrence of alpha 1, 3-linked 4,6-dideoxy-4-formamido-D-mannopyranose residues. This feature was previously attributed only to the M antigen, which is also a homopolymer of the same sugar. B. melitensis biotype 3 and B. suis biotype 4 lipopolysaccharides showed characteristics of mixed A and M antigens. Immunoabsorption of these O polysaccharides on a column of immobilized A-antigen-specific monoclonal antibody enriched polymer chains with A-antigen characteristics but did not eliminate M epitopes. Composite A- and M-antigen characteristics resulted from O polysaccharides in which the frequency of alpha 1,3 linkages, and hence, M-antigen characteristics, varied. All biotypes assigned as A+ M- expressed one or two alpha 1,3-linked residues per polysaccharide O chain. M antigens (M+ A-) also possessed a unique M epitope as well as a tetrasaccharide determinant common to A-antigen structures. B. canis and B. abortus 45/20, both rough strains, expressed low-molecular-weight A antigen.
Amigo, Cristina Román; de Gobbi, Debora Dirani Sena; Gomes, Vasco Túlio de Moura; Perina, Danilo do Prado; Nogueira de Lima Filsner, Pedro Henrique; Costa, Barbara Letícia Pereira; Spindola, Maria Garcia; Ferreira, Thais Sebastiana Porfida; Brandão, Paulo Eduardo; Moreno, Andrea Micke
Actinobaculum suis is an important agent related to urinary infection in swine females. Due to its fastidious growth characteristics, the isolation of this anaerobic bacterium is difficult, thus impairing the estimation of its prevalence. The purpose of this study was to develop and test a polymerase chain reaction (PCR) for the detection and identification of A. suis and then compare these results with traditional isolation methods. Bacterial isolation and PCR were performed on one hundred and ninety-two urine samples from sows and forty-five preputial swabs from boars. The results indicate that this PCR was specific for A. suis, presenting a detection limit between 1.0 × 101 CFU/mL and 1.0 × 102 CFU/mL. A. suis frequencies, as measured by PCR, were 8.9% (17/192) in sow urine samples and 82.2% (37/45) in preputial swabs. Assessed using conventional culturing techniques, none of the urine samples were positive for A. suis; however, A. suis was detected in 31.1% (14/45) of the swabs. This PCR technique was shown to be an efficient method for the detection of A. suis in urine and preputial swabs. PMID:23346017
Background The genus Brucella contains highly infectious species that are classified as biological threat agents. The timely detection and identification of the microorganism involved is essential for an effective response not only to biological warfare attacks but also to natural outbreaks. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) is a rapid method for the analysis of biological samples. The advantages of this method, compared to conventional techniques, are rapidity, cost-effectiveness, accuracy and suitability for the high-throughput identification of bacteria. Discrepancies between taxonomy and genetic relatedness on the species and biovar level complicate the development of detection and identification assays. Results In this study, the accurate identification of Brucella species using MALDI-TOF-MS was achieved by constructing a Brucella reference library based on multilocus variable-number tandem repeat analysis (MLVA) data. By comparing MS-spectra from Brucella species against a custom-made MALDI-TOF-MS reference library, MALDI-TOF-MS could be used as a rapid identification method for Brucella species. In this way, 99.3% of the 152 isolates tested were identified at the species level, and B. suis biovar 1 and 2 were identified at the level of their biovar. This result demonstrates that for Brucella, even minimal genomic differences between these serovars translate to specific proteomic differences. Conclusions MALDI-TOF-MS can be developed into a fast and reliable identification method for genetically highly related species when potential taxonomic and genetic inconsistencies are taken into consideration during the generation of the reference library. PMID:22192890
Kasymbekov, Joldoshbek; Imanseitov, Joldoshbek; Ballif, Marie; Schürch, Nadia; Paniga, Sandra; Pilo, Paola; Tonolla, Mauro; Benagli, Cinzia; Akylbekova, Kulyash; Jumakanova, Zarima; Schelling, Esther; Zinsstag, Jakob
The incidence of human brucellosis in Kyrgyzstan has been increasing in the last years and was identified as a priority disease needing most urgent control measures in the livestock population. The latest species identification of Brucella isolates in Kyrgyzstan was carried out in the 1960s and investigated the circulation of Brucella abortus, B. melitensis, B. ovis, and B. suis. However, supporting data and documentation of that experience are lacking. Therefore, typing of Brucella spp. and identification of the most important host species are necessary for the understanding of the main transmission routes and to adopt an effective brucellosis control policy in Kyrgyzstan. Overall, 17 B. melitensis strains from aborted fetuses of sheep and cattle isolated in the province of Naryn were studied. All strains were susceptible to trimethoprim-sulfamethoxazole, gentamicin, rifampin, ofloxacin, streptomycin, doxycycline, and ciprofloxacin. Multilocus variable number tandem repeat analysis showed low genetic diversity. Kyrgyz strains seem to be genetically associated with the Eastern Mediterranean group of the Brucella global phylogeny. We identified and confirmed transmission of B. melitensis to cattle and a close genetic relationship between B. melitensis strains isolated from sheep sharing the same pasture.
Martirosyan, Anna; Gorvel, Jean-Pierre
The complex immune system of mammals is the result of evolutionary forces that include battles against pathogens, as sensing and defeating intruders is a prerequisite to host survival. On the other hand, microorganisms have evolved multiple mechanisms to evade both arms of immunity: the innate and the adaptive immune systems. The successful pathogenic intracellular bacterium Brucella is not an exception to the rule: Brucella displays mechanisms that allow evasion of immune surveillance in order to establish persistent infections in mammals. In this review, we highlight some key mechanisms that pathogenic Brucella use to evade the adaptive immune system.
Kulakov Yu K
Brucellosis is a dangerous zoonotic disease of animals and humans caused by bacteria of the genus Brucella, which are able to survive, multiply, and persist in host cells. The review is devoted to the Brucella species persistence connected to the molecular mechanisms of escape from innate and adaptive immunity of the host and active interaction of effector proteins of the type IV secretion system with the host's signaling pathways. Understanding of the molecular mechanisms used by Brucella for the intracellular persistence in the host organism can allow us to develop new and effective means for the prevention and treatment of chronic brucellosis infection.
Donati, Manuela; Balboni, Andrea; Laroucau, Karine; Aaziz, Rachid; Vorimore, Fabien; Borel, Nicole; Morandi, Federico; Vecchio Nepita, Edoardo; Di Francesco, Antonietta
The aims of the present study were to assess the prevalence of Chlamydia suis in an Italian pig herd, determine the tetracycline susceptibility of C. suis isolates, and evaluate tet(C) and tetR(C) gene expression. Conjunctival swabs from 20 pigs were tested for C. suis by real-time polymerase chain reaction, and 55% (11) were positive. C. suis was then isolated from 11 conjunctival swabs resampled from the same herd. All positive samples and isolates were positive for the tet(C) resistance gene. The in vitro susceptibility to tetracycline of the C. suis isolates showed MIC values ranging from 0.5 to 4 μg/mL. Tet(C) and tetR(C) transcripts were found in all the isolates, cultured both in the absence and presence of tetracycline. This contrasts with other Gram-negative bacteria in which both genes are repressed in the absence of the drug. Further investigation into tet gene regulation in C. suis is needed.
Larsen, Anett K; Nymo, Ingebjørg H; Boysen, Preben; Tryland, Morten; Godfroid, Jacques
A high prevalence of Brucellapinnipedialis serology and bacteriology positive animals has been found in the Northeast Atlantic stock of hooded seal (Cystophoracristata); however no associated gross pathological changes have been identified. Marine mammal brucellae have previously displayed different infection patterns in human and murine macrophages. To investigate if marine mammal Brucella spp. are able to invade and multiply in cells originating from a presumed host species, we infected alveolar macrophages from hooded seal with a B. pinnipedialis hooded seal isolate. Hooded seal alveolar macrophages were also challenged with B. pinnipedialis reference strain (NCTC 12890) from harbor seal (Phocavitulina), B. ceti reference strain (NCTC 12891) from harbor porpoise (Phocoenaphocoena) and a B. ceti Atlantic white-sided dolphin (Lagenorhynchusacutus) isolate (M83/07/1), to evaluate possible species-specific differences. Brucella suis 1330 was included as a positive control. Alveolar macrophages were obtained by post mortem bronchoalveolar lavage of euthanized hooded seals. Phenotyping of cells in the lavage fluid was executed by flow cytometry using the surface markers CD14 and CD18. Cultured lavage cells were identified as alveolar macrophages based on morphology, expression of surface markers and phagocytic ability. Alveolar macrophages were challenged with Brucella spp. in a gentamicin protection assay. Following infection, cell lysates from different time points were plated and evaluated quantitatively for colony forming units. Intracellular presence of B. pinnipedialis hooded seal isolate was verified by immunocytochemistry. Our results show that the marine mammal brucellae were able to enter hooded seal alveolar macrophages; however, they did not multiply intracellularly and were eliminated within 48 hours, to the contrary of B. suis that showed the classical pattern of a pathogenic strain. In conclusion, none of the four marine mammal strains tested were able
Larsen, Anett K.; Nymo, Ingebjørg H.; Boysen, Preben; Tryland, Morten; Godfroid, Jacques
A high prevalence of Brucellapinnipedialis serology and bacteriology positive animals has been found in the Northeast Atlantic stock of hooded seal (Cystophoracristata); however no associated gross pathological changes have been identified. Marine mammal brucellae have previously displayed different infection patterns in human and murine macrophages. To investigate if marine mammal Brucella spp. are able to invade and multiply in cells originating from a presumed host species, we infected alveolar macrophages from hooded seal with a B. pinnipedialis hooded seal isolate. Hooded seal alveolar macrophages were also challenged with B. pinnipedialis reference strain (NCTC 12890) from harbor seal (Phocavitulina), B. ceti reference strain (NCTC 12891) from harbor porpoise (Phocoenaphocoena) and a B. ceti Atlantic white-sided dolphin (Lagenorhynchusacutus) isolate (M83/07/1), to evaluate possible species-specific differences. Brucella suis 1330 was included as a positive control. Alveolar macrophages were obtained by post mortem bronchoalveolar lavage of euthanized hooded seals. Phenotyping of cells in the lavage fluid was executed by flow cytometry using the surface markers CD14 and CD18. Cultured lavage cells were identified as alveolar macrophages based on morphology, expression of surface markers and phagocytic ability. Alveolar macrophages were challenged with Brucella spp. in a gentamicin protection assay. Following infection, cell lysates from different time points were plated and evaluated quantitatively for colony forming units. Intracellular presence of B. pinnipedialis hooded seal isolate was verified by immunocytochemistry. Our results show that the marine mammal brucellae were able to enter hooded seal alveolar macrophages; however, they did not multiply intracellularly and were eliminated within 48 hours, to the contrary of B. suis that showed the classical pattern of a pathogenic strain. In conclusion, none of the four marine mammal strains tested were able
Ferreira, Laura; Vega Castaño, Silvia; Sánchez-Juanes, Fernando; González-Cabrero, Sandra; Menegotto, Fabiola; Orduña-Domingo, Antonio
Background MALDI-TOF mass spectrometry (MS) is a reliable method for bacteria identification. Some databases used for this purpose lack reference profiles for Brucella species, which is still an important pathogen in wide areas around the world. We report the creation of profiles for MALDI-TOF Biotyper 2.0 database (Bruker Daltonics, Germany) and their usefulness for identifying brucellae from culture plates and blood cultures. Methodology/Principal Findings We created MALDI Biotyper 2.0 profiles for type strains belonging to B. melitensis biotypes 1, 2 and 3; B. abortus biotypes 1, 2, 5 and 9; B. suis, B. canis, B ceti and B. pinnipedialis. Then, 131 clinical isolates grown on plate cultures were used in triplicate to check identification. Identification at genus level was always correct, although in most cases the three replicates reported different identification at species level. Simulated blood cultures were performed with type strains belonging to the main human pathogenic species (B. melitensis, B. abortus, B. suis and B. canis), and studied by MALDI-TOF MS in triplicate. Identification at genus level was always correct. Conclusions/Significance MALDI-TOF MS is reliable for Brucella identification to the genus level from culture plates and directly from blood culture bottles. PMID:21151913
Taxonomy and nomenclature represent man-made systems designed to enhance understanding of the relationship between organisms by comparison of discrete sets of properties. Initial efforts at bacterial taxonomy were flawed as a result of the previous use of nonsystematic approaches including common names resulting in confusing and inaccurate nomenclature. A decision was made to start afresh with bacterial nomenclature and to avoid the hazards experienced in the taxonomic classification of higher organisms. This was achieved by developing new rules designed to simplify classification and avoid unnecessary and confusing changes. This article reviews the work of a number of scientists attempting to reconcile new molecular data describing the phylogenetic relationship between Brucella organisms and a broader family of organisms with widely variant phenotypes that include human virulence and host range against a backdrop of strict regulatory requirements that fail to recognize significant differences between organisms with similar nomenclature. PMID:20521932
Alvarez, Lucía Paula; García-Effrón, Guillermo; Robles, Carlos Alejandro
Brucellosis caused by Brucella ovis is one of the most important infectious diseases of sheep. The aim of this study was to determine the presence of genes both inside and outside the specific B. ovis pathogenicity island 1 (BOPI-1) in a large collection of field isolates of B. ovis and other Brucella spp. from Argentina. The BOV_A0500 gene from B. ovis BOPI-1 was identified in all 104 B. ovis isolates studied. The BOPI-1 complete sequence was found to be conserved in 10 B. ovis strains from the collection, for which whole genome sequencing was performed. The BOV_0198 gene, which is outside BOPI-1 and considered exclusive to B. ovis, showed 90-100% identity with genomic regions of B. ovis, B. melitensis, B. abortus, B. canis, B. suis, B. microti, B. ceti and B. pinnipedialis. The results demonstrate that BOPI-1 is the only exclusive genetic region of B. ovis and marine Brucella spp. and that it is highly conserved in B. ovis field isolates from Argentina.
Vaccination has played an enormous role in reducing brucellosis in many countries. It is certain to continue to be the preeminent factor in control of the disease in others. The search for an ideal vaccine continues. Live vaccines have proved to be superior to inactivated products. They are effective, inexpensive, and immunity is more persistent. The disadvantages of postvaccinal antibodies can be minimized by reduction of previously recommended doses and through use of supplemental diagnostic tests. These procedures now make entire population vaccination of great practical significance with many advantages over limited use of the strains 19 and Rev. 1. Adult animal vaccination should be much more extensive in many countries. A live B. suis strain 2 vaccine developed in China deserves much additional evaluation, including use in swine, for which no satisfactory vaccine exists. It is generally agreed that cell-mediated responses are the dominant aspect of immunogenesis. However, the correlates that have frequently been used--dermal hypersensitivity and lymphocyte stimulation in vitro--appear to be poor indices of cell-mediated immunity in brucellosis. Many studies have shown that postvaccinal antibodies do not predict subsequent immunity. There is a great need for simple in vivo or in vitro methods to measure CMI. While vaccination of humans may be useful in control of brucellosis in some high-risk occupations, the ultimate success is dependent upon reduction of this very important zoonosis in natural hosts. This is most effectively accomplished by widespread use of vaccination.
Kumar, Sanjay; Tuteja, Urmil; Batra, Harsh Vardhan
In the present study hybridomas were produced from fusion with splenocytes of BALB/c mice immunized with the recombinant 31-kDa cell surface protein (r31CSP) specific for Brucella species. A set of eight stabilized hybridoma cell lines was generated against r31CSP. Monoclonal antibodies (MAbs) produced by all these clones exhibited reactivity for r31CSP as well as with the protein of 31-kDa, derived from whole-cell lysate of 31-kDa Brucella abortus 544. Four of eight MAbs were IgG1, two IgG2b, and two IgM in nature. These MAbs did not show any cross-reaction with whole-cell lysate of Yersinia enterocolitica O: 9, Vibrio cholerae, Salmonella typhimurium and Escherichia coli 0157 by Western blotting. Reactivity of these MAbs was further assessed with other organisms of Brucella species namely, B. abortus S99, B. canis, B. melitensis 16M, B. suis, and a clinical isolate of B. melitensis. Collectively, these data suggest that these MAbs may have the potential for use in the detection of Brucella species with high specificity.
Agarwal, Sanjeev Kumar; Rajani, Ali Raza; Hussain, Kosar; Dande, Mangesh Manoharrao
A young man presented with a 2-month history of fever and malaise. Cardiac auscultation revealed the presence of a diastolic murmur. Subsequently, a cardiac echocardiogram was done, which showed a large vegetation adherent to an anterior mitral leaflet. The blood culture was positive for Brucella species. The patient was given antibiotic therapy for brucellosis and referred for surgery. Brucella endocarditis is one of the rarest, yet most notorious complications of this infection. This condition requires a high degree of clinical suspicion in order to facilitate prompt diagnosis and treatment.
Elberg, Sanford S.
The author describes a study, carried out in the Province of Córdoba, Spain, to test the efficacy of a live vaccine prepared from the Rev I strain of Brucella melitensis against caprine brucellosis and to determine the extent of natural infection in goats and humans in the Province. It was found that the vaccine significantly increased the resistance of the goats to infection without inducing a carrier state of the vaccine strain and that the immunity persisted for at least 15 months—the period of test. Serum agglutination tests, milk ring tests, and milk culture tests on goats showed that approximately 16-29% of the individual animals examined would be considered infective on the basis of one or other of the tests. Of the 118 herds tested, 111 were discovered to be harbouring infected animals. Serum agglutination tests on humans revealed that 25 of the 880 people tested (2.8%) had titres of 160 International Units (IU) or above and that, on the basis of a diagnostic titre of 80 IU or above, 7% of the population would be regarded as showing evidence of a past or present infection. PMID:13819864
Bonifait, Laetitia; Veillette, Marc; Létourneau, Valérie; Grenier, Daniel
Streptococcus suis is an important swine pathogen that can cause septicemia, meningitis, and pneumonia. Also recognized as an emerging zoonotic agent, it is responsible for outbreaks of human infections in Asian countries. Serotype 2 is the predominant isolate from diseased animals and humans. The aerosolization of S. suis in the air of swine confinement buildings (SCB) was studied. The presence of S. suis in bioaerosols was monitored in SCB where cases of infection had been reported and in healthy SCB without reported infections. Using a quantitative-PCR (qPCR) method, we determined the total number of bacteria (1 × 108 to 2 × 108 airborne/m3), total number of S. suis bacteria (4 × 105 to 10 × 105 airborne/m3), and number of S. suis serotype 2 and 1/2 bacteria (1 × 103 to 30 × 103 airborne/m3) present in the air. S. suis serotypes 2 and 1/2 were detected in the air of all growing/finishing SCB that had documented cases of S. suis infection and in 50% of healthy SCB. The total number of bacteria and total numbers of S. suis and S. suis serotype 2 and 1/2 bacteria were monitored in one positive SCB during a 5-week period, and it was shown that the aerosolized S. suis serotypes 2 and 1/2 remain airborne for a prolonged period. When the effect of aerosolization on S. suis was observed, the percentage of intact S. suis bacteria (showing cell membrane integrity) in the air might have been up to 13%. Finally S. suis was found in nasal swabs from 14 out of 21 healthy finishing-SCB workers, suggesting significant exposure to the pathogen. This report provides a better understanding of the aerosolization, prevalence, and persistence of S. suis in SCB. PMID:24632262
Hunter, S B; Bibb, W F; Shih, C N; Kaufmann, A F; Mitchell, J R; McKinney, R M
We developed an enzyme-linked immunosorbent assay (ELISA) system to measure human immunoglobulin G (IgG) and IgM response to the major outer membrane proteins of Brucella melitensis. The ELISA was more sensitive in detecting antibody than a standard microagglutination (MA) test with B. abortus antigen. Of 101 sera from persons with suspected brucellosis, 79 (78.2%) gave ELISA IgM titers greater than or equal to the B. abortus MA titer without 2-mercaptoethanol (2ME), which measures both IgM and IgG. Of the 101 sera, 97% gave ELISA IgG titers greater than or equal to the MA with 2ME titer. A total of 58 sera, drawn from 11 human patients from 1 to 29 weeks after onset of brucellosis, gave higher geometric mean titers for the ELISA IgG test than for the MA with 2ME test. These 58 sera also gave ELISA IgM geometric mean titers that were greater than or within one doubling dilution of the geometric mean titers of MA without 2ME. In addition to detecting antibody response to B. abortus, B. melitensis, and B. suis, the ELISA was sensitive to antibody response to human and canine infections with B. canis. The B. canis antibody response is not detected by the MA test with B. abortus antigen. The ELISA, with a standard preparation of major outer membrane proteins of B. melitensis as antigen, appears to be useful in measuring antibody response in humans to infections by all species of Brucella known to infect humans. PMID:3095364
Mancilla, Marcos; Marín, Clara M; Blasco, José M; Zárraga, Ana María; López-Goñi, Ignacio; Moriyón, Ignacio
The brucellae are Gram-negative pathogens that cause brucellosis, a zoonosis of worldwide importance. The genus Brucella includes smooth and rough species that differ in that they carry smooth and rough lipopolysaccharides, respectively. Brucella abortus, B. melitensis, and B. suis are typical smooth species. However, these smooth brucellae dissociate into rough mutants devoid of the lipopolysaccharide O-polysaccharide, a major antigen and a virulence determinant encoded in regions wbo (included in genomic island-2) and wbk. We demonstrate here the occurrence of spontaneous recombination events in those three Brucella species leading to the deletion of a 5.5-kb fragment carrying the wbkA glycosyltranferase gene and to the appearance of rough mutants. Analysis of the recombination intermediates suggested homologous recombination between the ISBm1 insertion sequences flanking wbkA as the mechanism generating the deletion. Excision of wbkA was reduced but not abrogated in a recA-deficient mutant, showing the existence of both RecA-dependent and -independent processes. Although the involvement of the ISBm1 copies flanking wbkA suggested a transpositional event, the predicted transpositional joint could not be detected. This absence of detectable transposition was consistent with the presence of polymorphism in the inverted repeats of one of the ISBm1 copies. The spontaneous excision of wbkA represents a novel dissociation mechanism of smooth brucellae that adds to the previously described excision of genomic island-2. This ISBm1-mediated wbkA excision and the different %GC levels of the excised fragment and of other wbk genes suggest that the Brucella wbk locus is the result of at least two horizontal acquisition events.
Donati, Manuela; Di Paolo, Maria; Favaroni, Alison; Aldini, Rita; Di Francesco, Antonietta; Ostanello, Fabio; Biondi, Roberta; Cremonini, Eleonora; Ginocchietti, Laura; Cevenini, Roberto
A mouse model for Chlamydia suis genital infection was developed. Ninety-nine mice were randomly divided into three groups and intravaginally inoculated with chlamydia: 45 mice (group 1) received C. suis purified elementary bodies (EBs), 27 (group 2) were inoculated with C. trachomatis genotype E EBs and 27 mice (group 3) with C. trachomatis genotype F EBs. Additionally, 10 mice were used as a negative control. At seven days post-infection (dpi) secretory anti-C. suis IgA were recovered from vaginal swabs of all C. suis inoculated mice. Chlamydia suis was isolated from 93, 84, 71 and 33% vaginal swabs at 3, 5, 7 and 12 dpi. Chlamydia trachomatis genotype E and F were isolated from 100% vaginal swabs up to 7 dpi and from 61 and 72%, respectively, at 12 dpi. Viable C. suis and C. trachomatis organisms were isolated from uterus and tubes up to 16 and 28 dpi, respectively. The results of the present study show the susceptibility of mice to intravaginal inoculation with C. suis. A more rapid course and resolution of C. suis infection, in comparison to C. trachomatis, was highlighted. The mouse model could be useful for comparative investigations involving C. suis and C. trachomatis species.
Michaux-Charachon, S; Bourg, G; Jumas-Bilak, E; Guigue-Talet, P; Allardet-Servent, A; O'Callaghan, D; Ramuz, M
PacI and SpeI restriction maps were obtained for the two chromosomes of each of the six species of the genus Brucella: B. melitensis, B. abortus, B. suis, B. canis, B. ovis, and B. neotomae. Three complementary techniques were used: hybridization with the two replicons as probes, cross-hybridization of restriction fragments, and a new mapping method. For each type strain, a unique I-SceI site was introduced in each of the two replicons, and the location of SpeI sites was determined by linearization at the unique site, partial digestion, and end labeling of the fragments. The restriction and genetic maps of the six species were highly conserved. However, numerous small insertions or deletions, ranging from 1 to 34 kb, were observed by comparison with the map of the reference strain of the genus, B. melitensis 16M. A 21-kb Spel fragment specific to B. ovis was found in the small chromosome of this species. A 640-kb inversion was demonstrated in the B. abortus small chromosome. All of these data allowed the construction of a phylogenetic tree, which reflects the traditional phenetic classification of the genus. PMID:9150220
Michaux-Charachon, S; Bourg, G; Jumas-Bilak, E; Guigue-Talet, P; Allardet-Servent, A; O'Callaghan, D; Ramuz, M
PacI and SpeI restriction maps were obtained for the two chromosomes of each of the six species of the genus Brucella: B. melitensis, B. abortus, B. suis, B. canis, B. ovis, and B. neotomae. Three complementary techniques were used: hybridization with the two replicons as probes, cross-hybridization of restriction fragments, and a new mapping method. For each type strain, a unique I-SceI site was introduced in each of the two replicons, and the location of SpeI sites was determined by linearization at the unique site, partial digestion, and end labeling of the fragments. The restriction and genetic maps of the six species were highly conserved. However, numerous small insertions or deletions, ranging from 1 to 34 kb, were observed by comparison with the map of the reference strain of the genus, B. melitensis 16M. A 21-kb Spel fragment specific to B. ovis was found in the small chromosome of this species. A 640-kb inversion was demonstrated in the B. abortus small chromosome. All of these data allowed the construction of a phylogenetic tree, which reflects the traditional phenetic classification of the genus.
... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Brucella Abortus Vaccine. 113.65... Bacterial Vaccines § 113.65 Brucella Abortus Vaccine. Brucella Abortus Vaccine shall be prepared as a desiccated live culture bacterial vaccine from smooth colonial forms of the Brucella abortus...
... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Brucella Abortus Vaccine. 113.65... Bacterial Vaccines § 113.65 Brucella Abortus Vaccine. Brucella Abortus Vaccine shall be prepared as a desiccated live culture bacterial vaccine from smooth colonial forms of the Brucella abortus...
... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Brucella Abortus Vaccine. 113.65... Bacterial Vaccines § 113.65 Brucella Abortus Vaccine. Brucella Abortus Vaccine shall be prepared as a desiccated live culture bacterial vaccine from smooth colonial forms of the Brucella abortus...
... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Brucella Abortus Vaccine. 113.65... Bacterial Vaccines § 113.65 Brucella Abortus Vaccine. Brucella Abortus Vaccine shall be prepared as a desiccated live culture bacterial vaccine from smooth colonial forms of the Brucella abortus...
... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Brucella Abortus Vaccine. 113.65... Bacterial Vaccines § 113.65 Brucella Abortus Vaccine. Brucella Abortus Vaccine shall be prepared as a desiccated live culture bacterial vaccine from smooth colonial forms of the Brucella abortus...
Ye, Changyun; Zhu, Xiaoping; Jing, Huaiqi; Du, Huamao; Segura, Mariela; Zheng, Han; Kan, Biao; Wang, Lili; Bai, Xuemei; Zhou, Yongyun; Cui, Zhigang; Zhang, Shouying; Jin, Dong; Sun, Na; Luo, Xia; Zhang, Ji; Gong, Zhaolong; Wang, Xin; Wang, Lei; Sun, Hui; Li, Zhenjun; Sun, Qiangzheng; Liu, Honglu; Dong, Boqing; Ke, Changwen; Yuan, Hui; Wang, Hua; Tian, Kecheng; Wang, Yu; Gottschalk, Marcelo
An outbreak of Streptococcus suis serotype 2 emerged in the summer of 2005 in Sichuan Province, and sporadic infections occurred in 4 additional provinces of China. In total, 99 S. suis strains were isolated and analyzed in this study: 88 isolates from human patients and 11 from diseased pigs. We defined 98 of 99 isolates as pulse type I by using pulsed-field gel electrophoresis analysis of SmaI-digested chromosomal DNA. Furthermore, multilocus sequence typing classified 97 of 98 members of the pulse type I in the same sequence type (ST), ST-7. Isolates of ST-7 were more toxic to peripheral blood mononuclear cells than ST-1 strains. S. suis ST-7, the causative agent, was a single-locus variant of ST-1 with increased virulence. These findings strongly suggest that ST-7 is an emerging, highly virulent S. suis clone that caused the largest S. suis outbreak ever described. PMID:16965698
Al Dahouk, Sascha; Köhler, Stephan; Occhialini, Alessandra; Jiménez de Bagüés, María Pilar; Hammerl, Jens Andre; Eisenberg, Tobias; Vergnaud, Gilles; Cloeckaert, Axel; Zygmunt, Michel S.; Whatmore, Adrian M.; Melzer, Falk; Drees, Kevin P.; Foster, Jeffrey T.; Wattam, Alice R.; Scholz, Holger C.
Twenty-one small Gram-negative motile coccobacilli were isolated from 15 systemically diseased African bullfrogs (Pyxicephalus edulis), and were initially identified as Ochrobactrum anthropi by standard microbiological identification systems. Phylogenetic reconstructions using combined molecular analyses and comparative whole genome analysis of the most diverse of the bullfrog strains verified affiliation with the genus Brucella and placed the isolates in a cluster containing B. inopinata and the other non-classical Brucella species but also revealed significant genetic differences within the group. Four representative but molecularly and phenotypically diverse strains were used for in vitro and in vivo infection experiments. All readily multiplied in macrophage-like murine J774-cells, and their overall intramacrophagic growth rate was comparable to that of B. inopinata BO1 and slightly higher than that of B. microti CCM 4915. In the BALB/c murine model of infection these strains replicated in both spleen and liver, but were less efficient than B. suis 1330. Some strains survived in the mammalian host for up to 12 weeks. The heterogeneity of these novel strains hampers a single species description but their phenotypic and genetic features suggest that they represent an evolutionary link between a soil-associated ancestor and the mammalian host-adapted pathogenic Brucella species. PMID:28300153
Du, Z Q; Wang, J Y
Brucella, an intracellular parasite that infects some livestock and humans, can damage or destroy the reproductive system of livestock. The syndrome is referred to as brucellosis and often occurs in pastoral areas; it is contagious from livestock to humans. In this study, the intact Brucella suis outer membrane protein 31 (omp31) gene was cloned, recombinantly expressed, and examined as a subunit vaccine candidate. The intact Brucella lumazine synthase (bls) gene was cloned and recombinantly expressed to study polymerization function in vitro. Non-reducing gel electrophoresis showed that rBs-BLS existed in different forms in vitro, including as a dimer and a pentamer. An enzyme-linked immunosorbent assay result showed that rOmp31 protein could induce production of an antibody in rabbits. However, the rOmp31-BLS fusion protein could elicit a much higher antibody titer in rabbits; this construct involved fusion of the Omp31 molecule with the BLS molecule. Our results indicate that Omp31 is involved in immune stimulation, while BLS has a polymerizing function based on rOmp31-BLS fusion protein immunogenicity. These data suggest that Omp31 is an ideal subunit vaccine candidate and that the BLS molecule is a favorable transport vector for antigenic proteins.
Martin, Fernando A.; Posadas, Diana M.; Carrica, Mariela C.; Cravero, Silvio L.; O'Callaghan, David; Zorreguieta, Angeles
The RND-type efflux pumps are responsible for the multidrug resistance phenotype observed in many clinically relevant species. Also, RND pumps have been implicated in physiological processes, with roles in the virulence mechanisms of several pathogenic bacteria. We have previously shown that the BepC outer membrane factor of Brucella suis is involved in the efflux of diverse drugs, probably as part of a tripartite complex with an inner membrane translocase. In the present work, we characterize two membrane fusion protein-RND translocases of B. suis encoded by the bepDE and bepFG loci. MIC assays showed that the B. suis ΔbepE mutant was more sensitive to deoxycholate (DOC), ethidium bromide, and crystal violet. Furthermore, multicopy bepDE increased resistance to DOC and crystal violet and also to other drugs, including ampicillin, norfloxacin, ciprofloxacin, tetracycline, and doxycycline. In contrast to the ΔbepE mutant, the resistance profile of B. suis remained unaltered when the other RND gene (bepG) was deleted. However, the ΔbepE ΔbepG double mutant showed a more severe phenotype than the ΔbepE mutant, indicating that BepFG also contributes to drug resistance. An open reading frame (bepR) coding for a putative regulatory protein of the TetR family was found upstream of the bepDE locus. BepR strongly repressed the activity of the bepDE promoter, but DOC released the repression mediated by BepR. A clear induction of the bepFG promoter activity was observed only in the BepDE-defective mutant, indicating a regulatory interplay between the two RND efflux pumps. Although only the BepFG-defective mutant showed a moderate attenuation in model cells, the activities of both bepDE and bepFG promoters were induced in the intracellular environment of HeLa cells. Our results show that B. suis harbors two functional RND efflux pumps that may contribute to virulence. PMID:19201794
Ekers, B M
Results of the typing of Brucella cultures received at the WHO Brucellosis Centre, CSL, Melbourne, from 1968-1976 are presented. The distribution of the biotypes of cultures recovered throughout Australia is shown on a host and State basis and atypical cultures are discussed. Cultures identified from Australia were Br. abortus, biotypes 1, 2 and 4 and Strain 19; Br. suis, biotype 1 and Br. ovis. Br. melitensis biotypes 1, 2 and 3 were recorded only as exotic human infections from the Mediterranean area and from laboratory infections. Br. abortus, biotype 1 was the most common bovine and human isolate and was found in horses, a goat and a sheep. There was a low incidence of Br. abortus, biotype 2 in cattle and it was found in 1 horse. Br. abortus, biotype 3 was not found in Australia but was submitted from Tanzania. Br. abortus, biotype 4 was rare in cattle and was found once in a horse. Br. abortus, Strain 19 was found occasionally in cattle and once from a test guinea pig. Br. suis, biotype 1 was found in both man and pigs in Queensland and New South Wales whereas biotype 3 was isolated only in New Guinea from pigs and cattle. Br. ovis was submitted from 3 States. Br. canis has not been found in Australia.
von Bargen, Kristine; Gorvel, Jean-Pierre; Salcedo, Suzana P
Bacteria of the genus Brucella are Gram-negative pathogens of several animal species that cause a zoonotic disease in humans known as brucellosis or Malta fever. Within their hosts, brucellae reside within different cell types where they establish a replicative niche and remain protected from the immune response. The aim of this article is to discuss recent advances in the field in the specific context of the Brucella intracellular 'lifestyle'. We initially discuss the different host cell targets and their relevance during infection. As it represents the key to intracellular replication, the focus is then set on the maturation of the Brucella phagosome, with particular emphasis on the Brucella factors that are directly implicated in intracellular trafficking and modulation of host cell signalling pathways. Recent data on the role of the type IV secretion system are discussed, novel effector molecules identified and how some of them impact on trafficking events. Current knowledge on Brucella gene regulation and control of host cell death are summarized, as they directly affect intracellular persistence. Understanding how Brucella molecules interplay with their host cell targets to modulate cellular functions and establish the intracellular niche will help unravel how this pathogen causes disease.
Wu, Chang-Xian; Xu, Xian-Jin; Zheng, Ke; Liu, Fang; Yang, Xu-Dong; Chen, Chuang-Fu; Chen, Huan-Chun; Liu, Zheng-Fei
Bacterial ribonuclease III (RNase III) is a highly conserved endonuclease, which plays pivotal roles in RNA maturation and decay pathways by cleaving double-stranded structure of RNAs. Here we cloned rncS gene from the genomic DNA of Brucella melitensis, and analyzed the cleavage properties of RNase III from Brucella. We identified Brucella-encoding small RNA (sRNA) by high-throughput sequencing and northern blot, and found that sRNA of Brucella and Homo miRNA precursor (pre-miRNA) can be bound and cleaved by B.melitensis ribonuclease III (Bm-RNase III). Cleavage activity of Bm-RNase III is bivalent metal cations- and alkaline buffer-dependent. We constructed several point mutations in Bm-RNase III, whose cleavage activity indicated that the 133th Glutamic acid residue was required for catalytic activity. Western blot revealed that Bm-RNase III was differently expressed in Brucella virulence strain 027 and vaccine strain M5-90. Collectively, our data suggest that Brucella RNase III can efficiently bind and cleave stem-loop structure of small RNA, and might participate in regulation of virulence in Brucella.
Byndloss, Mariana X; Tsolis, Renee M
Brucellosis, caused by bacteria of the genus Brucella, is an important zoonotic infection that causes reproductive disease in domestic animals and chronic debilitating disease in humans. An intriguing aspect of Brucella infection is the ability of these bacteria to evade the host immune response, leading to pathogen persistence. Conversely, in the reproductive tract of infected animals, this stealthy pathogen is able to cause an acute severe inflammatory response. In this review, we discuss the different mechanisms used by Brucella to cause disease, with emphasis on its virulence factors and the dichotomy between chronic persistence and reproductive disease.
Sánchez del Rey, V; Fernández-Garayzábal, J F; Briones, V; Iriso, A; Domínguez, L; Gottschalk, M; Vela, A I
This work aims to investigate the presence of Streptococcus suis in wild rabbits. A total of 65 S. suis isolates were recovered from 33.3% of the wild rabbits examined. Most isolates (86.2%) belong to genotype cps9. These isolates were further characterized by pulsed field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and virulence genotyping. Overall, S. suis exhibited a low genetic diversity. Only 5 genetic profiles were obtained by PFGE and most isolates (71.4%) were included in two pulsotypes that were also widely distributed among the wild rabbit population. MLST analysis assigned all cps9 isolates into three new singlestones (ST216, ST217 and ST284), which were not genetically related to the European ST87 and Spanish ST61 widespread swine clones, indicating a different genetic background for the S. suis isolates from wild rabbits and pigs. Wild rabbit isolates exhibited the genotype mrp-/epf-/sly-, different from those showed by most of the swine S. suis isolates of the ST87 and ST61 clones. None of the S. suis isolated from wild rabbits exhibited the genotype cps2/mrp+/epf+/sly+ associated with human infections. These results indicate that S. suis isolates from wild rabbits are not genetically related with prevalent clones usually associated with infections in pigs or humans in Europe and do not exhibit either their virulence genotypes. Therefore, although wild rabbits could represent an unknown reservoir of this pathogen, they could not represent a potential risk for pigs or humans.
Ferrando, M. Laura; van Baarlen, Peter; Orrù, Germano; Piga, Rosaria; Bongers, Roger S.; Wels, Michiel; De Greeff, Astrid; Smith, Hilde E.; Wells, Jerry M.
Streptococcus suis is a major bacterial pathogen of young pigs causing worldwide economic problems for the pig industry. S. suis is also an emerging pathogen of humans. Colonization of porcine oropharynx by S. suis is considered to be a high risk factor for invasive disease. In the oropharyngeal cavity, where glucose is rapidly absorbed but dietary α-glucans persist, there is a profound effect of carbohydrate availability on the expression of virulence genes. Nineteen predicted or confirmed S. suis virulence genes that promote adhesion to and invasion of epithelial cells were expressed at higher levels when S. suis was supplied with the α-glucan starch/pullulan compared to glucose as the single carbon source. Additionally the production of suilysin, a toxin that damages epithelial cells, was increased more than ten-fold when glucose levels were low and S. suis was growing on pullulan. Based on biochemical, bioinformatics and in vitro and in vivo gene expression studies, we developed a biological model that postulates the effect of carbon catabolite repression on expression of virulence genes in the mucosa, organs and blood. This research increases our understanding of S. suis virulence mechanisms and has important implications for the design of future control strategies including the development of anti-infective strategies by modulating animal feed composition. PMID:24642967
Irajian, Gholam Reza; Masjedian Jazi, Faramarz; Mirnejad, Reza; Piranfar, Vahhab; Zahraei salehi, Taghi; Amir Mozafari, Noor; Ghaznavi-rad, Ehsanollah; Khormali, Mahmoud
Background: Brucellosis is an endemic zoonotic disease in the Middle East. This study intended to design a uniplex PCR assay for the detection and differentiation of Brucella at the species level and determining the antibiotic susceptibility pattern of Brucella in Iran. Methods: Sixty-eight Brucella specimens (38 animal and 30 human specimens) were analyzed using PCR (using one pair of primers). Antibiotic susceptibility patterns were evaluated and compared using the E-Test and disk diffusion susceptibility test. Tigecycline susceptibility pattern was compared with other antibiotics. Results: Thirty six isolates of B. melitensis, 2 isolates of B. abortus and 1 isolate of B. suis from the 38 animal specimens, 24 isolates of B. melitensis and 6 isolates of B. abortus from the 30 human specimens were differentiated. The MIC50 values of doxycycline for human and animal specimens were 125 and 10 μg/ml, respectively, tigecycline 0.064 μg/ml for human specimens and 0.125μg/ml for animal specimens, and trimethoprim/ sulfamethoxazole and ciprofloxacin 0.065 and 0.125μg/ml, respectively, for both human and animal specimens. The highest MIC50 value of streptomycin in the human specimens was 0.5μg/ml and 1μg/ml for the animal specimens. The greatest resistance shown was to tetracycline and gentamicin, respectively. Conclusion: Uniplex PCR for the detection and differentiation of Brucella at the strain level is faster and less expensive than multiplex PCR, and the antibiotics doxycycline, rifampin, trimethoprim-sulfamethoxazole, ciprofloxacin, and ofloxacin are the most effective antibiotics for treating brucellosis. Resistance to tigecycline is increasing, and we recommend that it be used in a combination regimen. PMID:27799972
Successful innovative 'leaps' in surgical technique have the potential to contribute exponentially to surgical advancement, and thereby to improved health outcomes for patients. Such innovative leaps often occur relatively spontaneously, without substantial forethought, planning, or preparation. This feature of surgical innovation raises special challenges for ensuring sufficient evaluation and regulatory oversight of new interventions that have not been the subject of controlled investigatory exploration and review. It is this feature in particular that makes early-stage surgical innovation especially resistant to classification as 'research', with all of the attendant methodological and ethical obligations--of planning, regulation, monitoring, reporting, and publication--associated with such a classification. This paper proposes conceptual and ethical grounds for a restricted definition according to which innovation in surgical technique is classified as a form of sui generis surgical 'research', where the explicit goal of adopting such a definition is to bring about needed improvements in knowledge transfer and thereby benefit current and future patients.
Vitry, Marie-Alice; Hanot Mambres, Delphine; Deghelt, Michaël; Hack, Katrin; Machelart, Arnaud; Lhomme, Frédéric; Vanderwinden, Jean-Marie; Vermeersch, Marjorie; De Trez, Carl; Pérez-Morga, David; Letesson, Jean-Jacques; Muraille, Eric
Brucella spp. are facultative intracellular Gram-negative coccobacilli responsible for brucellosis, a worldwide zoonosis. We observed that Brucella melitensis is able to persist for several weeks in the blood of intraperitoneally infected mice and that transferred blood at any time point tested is able to induce infection in naive recipient mice. Bacterial persistence in the blood is dramatically impaired by specific antibodies induced following Brucella vaccination. In contrast to Bartonella, the type IV secretion system and flagellar expression are not critically required for the persistence of Brucella in blood. ImageStream analysis of blood cells showed that following a brief extracellular phase, Brucella is associated mainly with the erythrocytes. Examination by confocal microscopy and transmission electron microscopy formally demonstrated that B. melitensis is able to invade erythrocytes in vivo. The bacteria do not seem to multiply in erythrocytes and are found free in the cytoplasm. Our results open up new areas for investigation and should serve in the development of novel strategies for the treatment or prophylaxis of brucellosis. Invasion of erythrocytes could potentially protect the bacterial cells from the host's immune response and hamper antibiotic treatment and suggests possible Brucella transmission by bloodsucking insects in nature.
Stuart, B P; Gosser, H S; Allen, C B; Bedell, D M
Coccidiosis is a disease of the young piglet due to infection with Isospora suis and is characterized by diarrhea which is nonresponsive to antibacterial therapy. There is variable morbidity and mortality. Piglets develop a more severe clinical illness and enteritis when infected with I. suis at one to three days of age than when infected at two weeks of age. Microscopic lesions range from villous atrophy and mild erosion to severe fibrinonecrotic enteritis.
Ji, Wenhui; Huang, Qingqing; Sun, Liang; Wang, Hengan; Yan, Yaxian; Sun, Jianhe
Streptococcus suis serotype 2 (S. suis 2) is a zoonotic pathogen that exhibits high-level resistance and multi-drug resistance to classic antibiotics and causes serious human casualties and heavy economic losses in the swine industry worldwide. Therefore, alternative therapies or novel antibacterial agents need to be developed to combat this pathogen. A novel endolysin derived from the S. suis temperate phage phi7917, termed Ly7917, was identified, which had broad lytic activity against S. suis type 1, 2, 7 and 9. Ly7917 consisted of an N-terminal cysteine, histidine-dependent amidohydrolases/peptidase catalytic domain and C-terminal SH3b cell wall binding domain. The endolysin maintained activity at high pH and its catalytic activity could be improved by addition of 10 μM 1.5 mM Ca(2+). In animal studies, 90% of BALB/c mice challenged with typical virulent strain HA9801 of S. suis 2 were protected by Ly7917 treatment. The bacterial load in the blood of HA9801-challenged mice was efficiently reduced almost 50% by Ly7917 while that of penicillin-G-treated mice kept almost unchanged. Our data suggest that Ly7917 may be an alternative therapeutic agent for infections caused by virulent S. suis strains.
Guo, Fei; Zhang, Hui; Chen, Chuangfu; Hu, Shengwei; Wang, Yuanzhi; Qiao, Jun; Ren, Yan; Zhang, Ke; Wang, Yong; Du, Guoqing
This study investigated the role of autophagy in the survival of the invasive bacterium Brucella melitensis strain 16M in murine macrophages. Here, Brucella melitensis 16M was found to trigger autophagosome formation, enhance autophagy flux and increase the expression level of the autophagy marker protein LC3-II. When autophagy was pharmacologically inhibited by 3-methyladenine (3-MA), Brucella replication efficiency was significantly decreased (p < 0.05). These results suggest that autophagy favors Brucella melitensis 16M survival in murine macrophages.
Minogue, T. D.; Daligault, H. A.; Davenport, K. W.; Bishop-Lilly, K. A.; Broomall, S. M.; Bruce, D. C.; Chain, P. S.; Chertkov, O.; Coyne, S. R.; Frey, K. G.; Gibbons, H. S.; Jaissle, J.; Koroleva, G. I.; Ladner, J. T.; Lo, C.-C.; Palacios, G. F.; Redden, C. L.; Rosenzweig, C. N.; Scholz, M. B.; Xu, Y.
Brucella species are intracellular zoonotic pathogens which cause, among other pathologies, increased rates of abortion in ruminants. Human infections are generally associated with exposure to contaminated and unpasteurized dairy products; however Brucellae have been developed as bioweapons. Here we present 17 complete and 7 scaffolded genome assemblies of Brucella strains. PMID:25237024
Hansen, Tina V.A.; Friis, Christian; Nejsum, Peter; Olsen, Annette; Thamsborg, Stig Milan
It is recognized that the clinical efficacy of single dose benzimidazoles (BZs) against the nematode, Trichuris suis of pigs and the closely related Trichuris trichiura in humans is only poor to moderate. Recent in vitro studies have indicated that a low uptake of fenbendazole (FBZ) in T. suis may be responsible for its poor efficacy. The aim of this study was to investigate this hypothesis by measuring the concentrations of FBZ and its metabolites, oxfendazole (OXF) and FBZ sulphone (FBZSO2), in T. suis isolated from FBZ treated pigs and in plasma of the pigs. The highest concentration of FBZ measured in T. suis was 66.6 pmol/mg dry worm tissue which was approximately half of what was measured in a previous in vitro study. The correlation between drug concentrations in plasma and in T. suis worms was highly positive for OXF (r = 0.93, P = 0.0007) and FBZSO2 (r = 0.85, P = 0.007), but no correlation was found for FBZ. This study shows that the low uptake of FBZ observed for T. suis in vitro, also takes place in vivo. The high and significant correlations between OXF and FBZSO2 concentrations in plasma of the pigs and T. suis (and the lack of this correlation for FBZ) suggests that the metabolites reach the worms via the blood–enterocyte interface while FBZ primarily reaches the worms via the intestinal lumen of the host. PMID:25057460
Doganay, Gizem D; Doganay, Mehmet
Perception on bioterrorism has changed after the deliberate release of anthrax by the postal system in the United States of America in 2001. Potential bioterrorism agents have been reclassified based on their dissemination, expected rate of mortality, availability, stability, and ability to lead a public panic. Brucella species can be easily cultured from infected animals and human materials. Also, it can be transferred, stored and disseminated easily. An intentional contamination of food with Brucella species could pose a threat with low mortality rate. Brucella spp. is highly infectious through aerosol route, making it an attractive pathogen to be used as a potential agent for biological warfare purposes. Recently, many studies have been concentrated on appropriate sampling of Brucella spp. from environment including finding ways for its early detection and development of new decontamination procedures such as new drugs and vaccines. There are many ongoing vaccine development studies; some of which recently received patents for detection and therapy of Brucella spp. However, there is still no available vaccine for humans. In this paper, recent developments and recent patents on brucellosis are reviewed and discussed.
Zhao, Jianqing; Lin, Lan; Fu, Lei; Han, Li; Zhang, Anding
Streptococcus suis infection induces formation of neutrophil extracellular traps (NETs) in vitro; however, the contribution of NETs-mediated killing to the pathogenesis of S. suis in vivo is yet to be elicited. The findings of the present study indicated that extracellular DNA fiber can be induced in a murine model in response to S. suis infection. A nuclease that destroys their structure was used to evaluate the role of NETs on S. suis infection. Treatment with nuclease resulted in a greater bacteria load and higher serum TNF-α concentrations in response to S. suis infection, indicating that NETs structure played an essential role in S. suis clearance and inflammation. Furthermore, nuclease treatment resulted in more severe clinical signs during and higher mortality from S. suis infection. These findings indicated that NETs structure contributes to protection against S. suis infection.
Rijpens, N P; Jannes, G; Van Asbroeck, M; Rossau, R; Herman, L M
The 16S-23S rRNA spacer regions of Brucella abortus, B. melitensis, and B. suis were cloned and subcloned after PCR amplification. Sequence analysis of the inserts revealed a spacer of about 800 bp with very high ( > 99%) homology among the three species examined. Two genus-specific primer pairs, BRU-P5-BRU-P8 and BRU-P6-BRU-P7, that could be used in a nested PCR format and three genus-specific DNA probes, BRU-ICG2, BRU-ICG3, and BRU-ICG4, were deduced from this spacer. The specificity and sensitivity of both primer sets and probes were examined by testing them against a collection of 18 Brucella strains and 56 strains from other relevant taxa by using PCR and the Line Probe Assay (LiPA), respectively. A method for direct detection of Brucella spp. in 1 ml of raw milk was developed on the basis of enzymatic treatment of the milk components and subsequent PCR and LiPA hybridization. After a single PCR, sensitivities of 2.8 x 10(5) and 2.8 x 10(4) CFU/ml were obtained for detection by agarose gel electrophoresis and LiPA, respectively. Nested PCR yielded a sensitivity of 2.8 x 10(2) CFU/ml for both methods. PMID:8633866
Martínez, Diana; Thompson, Carolina; Draghi, Graciela; Canavesio, Vilma; Jacobo, Roberto; Zimmer, Patricia; Elena, Sebastián; Nicola, Ana M; de Echaide, Susana Torioni
An isolate of Brucella spp. from an aborted water buffalo (Bubalus bubalis) fetus was characterized based on its pheno- and genotype. The phenotype was defined by carbon dioxide requirement, hydrogen sulfide production, sensitivity to thionin and basic fuchsin and agglutination with Brucella A and M monospecific antisera. The genotype was based on the amplification of the following genes: bcsp31, omp2ab, and eri and the species-specific localization of the insertion sequence IS711 in the Brucella chromosome via B. abortus-B. melitensis-B. ovis-B. suis (AMOS)-PCR. Unexpectedly, the isolate showed a phenotype different from B. abortus bv 1, the most prevalent strain in cattle in Argentina, and from vaccine strain 19, currently used in bovines and water buffaloes. Genotyping supported the phenotypic results, as the analysis of the omp2ab gene sequence showed an identical pattern to either B. abortus bv 5 or B. melitensis. Finally, the AMOS PCR generated a 1700-bp fragment from the isolate, different than those amplified from B. abortus bv 1 (498bp) and B. melitensis (731bp), confirming the presence of B. abortus bv 5. The OIE/FAO Reference Laboratory for Brucellosis confirmed this typing. This is the first report of B. abortus bv 5 from a water buffalo in the Americas.
Sánchez del Rey, Verónica; Fernández-Garayzábal, José F; Mentaberre, Gregorio; Briones, Víctor; Lavín, Santiago; Domínguez, Lucas; Gottschalk, Marcelo; Vela, Ana Isabel
Wild boar are widely distributed throughout the Iberian Peninsula and can carry potentially virulent strains of Streptococcus suis. The objective of this study was to determine the prevalence of S. suis in wild boars from two large geographical regions of Spain. Serotypes 1, 2, 7 and 9 identified were further genetically characterised by virulence-associated genotyping, pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) to determine the population structure of S. suis carried by these animals. Streptococcus suis was isolated from 39.1% of the wild boars examined: serotype 9 was the most frequently isolated (12.5%), followed by serotype 1 (2.5%). Serotype 2 was rarely isolated (0.3%). Eighteen additional serotypes were identified indicating wide diversity of this pathogen within the wild boar population. This heterogeneity was confirmed by PFGE and MLST analyses and the majority of isolates exhibited the virulence-associated genotype mrp-/epf-/sly-. The results of this study highlight that the carriage of S. suis by wild boars is commonplace. However, MLST data indicate that these isolates are not related to prevalent clonal complexes ST1, ST16, ST61 and ST87 typically associated with infection of pigs or humans in Europe.
Zhang, Shengwei; Wang, Junping; Chen, Shaolong; Yin, Jiye; Pan, Zhiyuan; Liu, Keke; Li, Lin; Zheng, Yuling; Yuan, Yuan; Jiang, Yongqiang
Blood platelets play important roles during pathological thrombocytopenia in streptococcal toxic shock syndrome (STSS). Streptococcus suis (S. suis) an emerging human pathogen, can cause STSS similarly to S. pyogenes. However, S. suis interactions with platelets are poorly understood. Here, we found that suilysin (SLY), different from other bacterial cholesterol-dependent cytolysins (CDCs), was the sole stimulus that induced platelet aggregation. Furthermore, the inside-out activation of GPIIb/IIIa of platelets mediated SLY-induced platelet aggregation. This process was triggered by Ca2+ influx that depend on the pore forming on platelets by SLY. Additionally, although SLY induced α-granule release occurred via the MLCK-dependent pathway, PLC-β-IP3/DAG-MLCK and Rho-ROCK-MLCK signaling were not involved in SLY-induced platelet aggregation. Interestingly, the pore dependent Ca2+ influx was also found to participate in the induction of platelet aggregation with pneumolysin (PLY) and streptolysin O (SLO), two other CDCs. It is possible that the CDC-mediated platelet aggregation we observed in S. suis is a similar response mechanism to that used by a wide range of bacteria. These findings might lead to the discovery of potential therapeutic targets for S. suis-associated STSS. PMID:27800304
Cox, Ashley; Herschorn, Sender; Lee, Livia
Many surgical options exist for women with stress urinary incontinence (SUI). The traditional gold standards of Burch retropubic colposuspension and pubovaginal slings are still appropriate treatment options for some patients, but randomized controlled trials have demonstrated that synthetic midurethral slings are just as effective as these traditional procedures but with less associated morbidity. Thus, midurethral slings--inserted via a retropubic or transobturator approach--have become the new gold standard first-line surgical treatment for women with uncomplicated SUI. Retropubic midurethral slings are associated with slightly higher success rates than transobturator slings, but at the cost of more postoperative complications. Pubovaginal slings remain an effective option for women with SUI who have failed other procedures, have had mesh complications, or who require concomitant urethral surgery. Single-incision slings have a number of benefits, including decreased operative times and early return to regular activities, but they are yet to be shown to be as effective as midurethral slings. Both retropubic and transobturator midurethral slings are effective for patients with mixed urinary incontinence, but the overall cure rate is lower than for patients with pure SUI. Based on the literature a new gold standard first-line surgical treatment for women with SUI is the synthetic midurethral sling inserted through a retropubic or transobturator approach [corrected].
Soares, Catharina de Paula Oliveira Cavalcanti; Teles, José Andreey Almeida; dos Santos, Aldenir Feitosa; Silva, Stemberg Oliveira Firmino; Cruz, Maria Vilma Rocha Andrade; da Silva-Júnior, Francisco Feliciano
Objective: to determine the seroprevalence of Brucella spp in humans. Method: this is an observational study, developed with 455 individuals between 18 and 64 years old, who use the Estratégia de Saúde da Família (Brazil's family health strategy). The serum samples of volunteers underwent buffered acid antigen tests, such as screening, agar gel immunodiffusion and slow seroagglutination test in tubes and 2-Mercaptoethanol. Results: among the samples, 1.98% has responded to buffered-acid antigen, 2.85% to agar gel immunodiffusion test and 1.54% to the slow seroagglutination tests on tubes/2-Mercaptoethanol. The prevalence of Brucella spp was 4.4%, represented by the last two tests. Conclusion: the results of this research suggest that the studied population is exposed to Brucella spp infection. PMID:26487143
Higgins, R; Gottschalk, M; Mittal, K R; Beaudoin, M
A total of 349 isolates of Streptococcus suis retrieved from different tissues from diseased pigs were examined in this study. Only 48% of them could be categorized as one of serotypes 1 to 8 and 1/2. Among typable isolates, serotype 2 was the most prevalent (23%), followed by serotype 3 (10%). The majority of all isolates originated from lungs, meninges/brain, and multiple tissues. Forty-one percent of typable isolates and 33% of untypable isolates were retrieved in pure culture. Other isolates were found in conjunction with Pasteurella multocida, Escherichia coli, Actinobacillus pleuropneumoniae, Actinomyces pyogenes, and other streptococci. Typable S. suis isolates were more frequently isolated from pigs between five and ten weeks of age, while untypable isolates were mostly found in animals aged more than 24 weeks. No obvious monthly and/or seasonal variation of the prevalence of isolation of S. suis could be detected. PMID:2306668
Yang, Yan-Bei; Chen, Jian-Qing; Zhao, Yu-Lin; Bai, Jing-Wen; Ding, Wen-Ya; Zhou, Yong-Hui; Chen, Xue-Ying; Liu, Di; Li, Yan-Hua
Streptococcus suis (S. suis) caused serious disease symptoms in humans and pigs. S. suis is able to form thick biofilms and this increases the difficulty of treatment. After growth with 1/2 minimal inhibitory concentration (MIC) of azithromycin, 1/4 MIC of azithromycin, or 1/8 MIC of azithromycin, biofilm formation of S. suis dose-dependently decreased in the present study. Furthermore, scanning electron microscopy analysis revealed the obvious effect of azithromycin against biofilm formation of S. suis. Especially, at two different conditions (1/2 MIC of azithromycin non-treated cells and treated cells), we carried out comparative proteomic analyses of cells by using iTRAQ technology. Finally, the results revealed the existence of 19 proteins of varying amounts. Interestingly, several cell surface proteins (such as ATP-binding cassette superfamily ATP-binding cassette transporter (G7SD52), CpsR (K0FG35), Cps1/2H (G8DTL7), CPS16F (E9NQ13), putative uncharacterized protein (G7SER0), NADP-dependent glyceraldehyde-3-phosphate dehydrogenase (G5L259), putative uncharacterized protein (G7S2D6), amino acid permease (B0M0G6), and NsuB (G5L351)) were found to be implicated in biofilm formation. More importantly, we also found that azithromycin affected expression of the genes cps1/2H, cpsR and cps16F. Especially, after growth with 1/2 MIC of azithromycin and 1/4 MIC of azithromycin, the capsular polysaccharide content of S. suis was significantly higher. PMID:27812354
Ahmed, Waqas; Zheng, Ke; Liu, Zheng-Fei
Brucella is a facultative intracellular pathogen that causes zoonotic infection known as brucellosis which results in abortion and infertility in natural host. Humans, especially in low income countries, can acquire infection by direct contact with infected animal or by consumption of animal products and show high morbidity, severe economic losses and public health problems. However for survival, host cells develop complex immune mechanisms to defeat and battle against attacking pathogens and maintain a balance between host resistance and Brucella virulence. On the other hand as a successful intracellular pathogen, Brucella has evolved multiple strategies to evade immune response mechanisms to establish persistent infection and replication within host. In this review, we mainly summarize the “Stealth” strategies employed by Brucella to modulate innate and the adaptive immune systems, autophagy, apoptosis and possible role of small noncoding RNA in the establishment of chronic infection. The purpose of this review is to give an overview for recent understanding how this pathogen evades immune response mechanisms of host, which will facilitate to understanding the pathogenesis of brucellosis and the development of novel, more effective therapeutic approaches to treat brucellosis. PMID:27014640
Ahmed, Waqas; Zheng, Ke; Liu, Zheng-Fei
Brucella is a facultative intracellular pathogen that causes zoonotic infection known as brucellosis which results in abortion and infertility in natural host. Humans, especially in low income countries, can acquire infection by direct contact with infected animal or by consumption of animal products and show high morbidity, severe economic losses and public health problems. However for survival, host cells develop complex immune mechanisms to defeat and battle against attacking pathogens and maintain a balance between host resistance and Brucella virulence. On the other hand as a successful intracellular pathogen, Brucella has evolved multiple strategies to evade immune response mechanisms to establish persistent infection and replication within host. In this review, we mainly summarize the "Stealth" strategies employed by Brucella to modulate innate and the adaptive immune systems, autophagy, apoptosis and possible role of small noncoding RNA in the establishment of chronic infection. The purpose of this review is to give an overview for recent understanding how this pathogen evades immune response mechanisms of host, which will facilitate to understanding the pathogenesis of brucellosis and the development of novel, more effective therapeutic approaches to treat brucellosis.
Wertheim, Heiman F. L.; Nguyen, Huyen Nguyen; Taylor, Walter; Lien, Trinh Thi Minh; Ngo, Hoa Thi; Nguyen, Thai Quoc; Nguyen, Bich Ngoc Thi; Nguyen, Ha Hong; Nguyen, Ha Minh; Nguyen, Cap Trung; Dao, Trinh Tuyet; Nguyen, Trung Vu; Fox, Annette; Farrar, Jeremy; Schultsz, Constance; Nguyen, Hien Duc; Nguyen, Kinh Van; Horby, Peter
Background Streptococcus suis can cause severe systemic infection in adults exposed to infected pigs or after consumption of undercooked pig products. S. suis is often misdiagnosed, due to lack of awareness and improper testing. Here we report the first fifty cases diagnosed with S. suis infection in northern Viet Nam. Methodology/Principal Findings In 2007, diagnostics for S. suis were set up at a national hospital in Hanoi. That year there were 43 S. suis positive cerebrospinal fluid samples, of which S. suis could be cultured in 32 cases and 11 cases were only positive by PCR. Seven patients were blood culture positive for S. suis but CSF culture and PCR negative; making a total of 50 patients with laboratory confirmed S. suis infection in 2007. The number of S. suis cases peaked during the warmer months. Conclusions/Significance S. suis was commonly diagnosed as a cause of bacterial meningitis in adults in northern Viet Nam. In countries where there is intense and widespread exposure of humans to pigs, S. suis can be an important human pathogen. PMID:19543404
Shope, Richard E.
Either living or heat-killed H. influenzae suis vaccines, given intramuscularly to swine, elicit an immune response capable of modifying the course of a later swine influenza infection. The protection afforded is only partial and is in no way comparable to the complete immunity afforded by swine influenza virus vaccines. PMID:19870654
Elfaki, Mohamed G; Alaidan, Alwaleed Abdullah; Al-Hokail, Abdullah Abdulrahman
Brucellosis is a zoonotic and contagious infectious disease caused by infection with Brucella species. The infecting brucellae are capable of causing a devastating multi-organ disease in humans with serious health complications. The pathogenesis of Brucella infection is influenced largely by host factors, Brucella species/strain, and the ability of invading brucellae to survive and replicate within mononuclear phagocytic cells, preferentially macrophages (Mf). Consequently, the course of human infection may appear as an acute fatal or progress into chronic debilitating infection with periodical episodes that leads to bacteremia and death. The existence of brucellae inside Mf represents one of the strategies used by Brucella to evade the host immune response and is responsible for treatment failure in certain human populations treated with anti-Brucella drugs. Moreover, the persistence of brucellae inside Mf complicates the diagnosis and may affect the host cell signaling pathways with consequent alterations in both innate and adaptive immune responses. Therefore, there is an urgent need to pursue the development of novel drugs and/or vaccine targets against human brucellosis using high throughput technologies in genomics, proteomics, and immunology.
Tarradas, C; Luque, I; de Andrés, D; Abdel-Aziz Shahein, Y E; Pons, P; González, F; Borge, C; Perea, A
Two cases of meningitis due to Streptococcus suis in humans are reported here. A butcher and an abattoir worker were referred to a health centre in Castellón (Spain) with fever and symptoms of meningitis. After adequate treatment, a slight hipoacusia persisted as sequelae in both cases. Colonies of S. suis group R, serotype 2 and phenotype MRP+EF+ were isolated from cerebroespinal fluid. Epidemiological studies showed that both workers had in common the handling of pork meat of slaughtered healthy pigs from three closed farms. A study of the tonsils from apparently healthy, slaughtered pigs was carried out. A total of 234 tonsillar samples were obtained and 81 strains of S. suis were isolated from them. Serotype 2 appeared to be the most frequent (50.6%), and the analysis for phenotype showed a high percentage of tonsillar strains with the phenotype MRP+EF+ (35.9%). The humans and 28 tonsillar swine strains showed a similar profile (S. suis group R, serotype 2 and phenotype MRP+EF+). A total of 26 of the swine isolates were analysed by ribotyping using EcoRI. The human strains showed the same six-band hybridization pattern that shared five bands with the pattern most frequently shown by most of the tonsillar N. suis group R, serotype 2 and phenotype MRP+EF+ strains, differing only in the lightest, faintest band which was slightly less anodical in human (> or = 1.8 kb) than in swine (approximately 1.8 kb). From these results, both groups of strains, humans and porcine, showed differences; how can these differences in the pattern of ribotyping be explained if they should have the same origin? Is it possible that they have undergone an adaptation to the new host or perhaps the modification is due to other unknown causes? Further studies in this area are required in order to answer these questions.
Kellerman, G D; Foster, J W; Badakhsh, F F
Amino acid, carbohydrate, and lipid components of cell walls of Brucella abortus strain 19A (low virulence) and strain 2308 (high virulence) were compared by thin layer chromatography (TLC) and by use of an amino acid analyzer. A total of 15 amino acids were detected by both chromatographic methods. Each amino acid was present in greater amounts in strain 2308 than in strain 19A when equal amounts of hydrolysates of cell wall and endotoxin-containing preparations were analyzed. A component with the same R(F) value as ethanolamine was present in strain 2308 cell wall hydrolysates but was not revealed by TLC of strain 19A cell wall hydrolysates. This component was not detected with the amino acid analyzer. TLC of cell walls tagged with 2,4-dinitrofluorobenzene prior to hydrolysis showed that phenylalanine was a terminal amino acid in cell walls of B. abortus strains 19A and 2308, B. suis strain 1776, and B. melitensis strain 2500. Carbohydrates detected in cell walls of strains 19A and 2308 by TLC were tentatively identified as glucose, mannose, rhamnose, and galactose. Colorimetric tests were also positive for 2-keto-3-deoxy-octulosonic acid, heptose, and dideoxyhexose. At least seven lipid components were detected by TLC of ether extracts of cell walls of strains 19A and 2308. It is suggested that one or more lipids is important in maintaining cell wall structure, because isolated cell walls rapidly became fragmented after exposure to ether.
Background Since 1994, Brucella strains have been isolated from a wide range of marine mammals. They are currently recognized as two new Brucella species, B. pinnipedialis for the pinniped isolates and B. ceti for the cetacean isolates in agreement with host preference and specific phenotypic and molecular markers. In order to investigate the genetic relationships within the marine mammal Brucella isolates and with reference to terrestrial mammal Brucella isolates, we applied in this study the Multiple Loci VNTR (Variable Number of Tandem Repeats) Analysis (MLVA) approach. A previously published assay comprising 16 loci (MLVA-16) that has been shown to be highly relevant and efficient for typing and clustering Brucella strains from animal and human origin was used. Results 294 marine mammal Brucella strains collected in European waters from 173 animals and a human isolate from New Zealand presumably from marine origin were investigated by MLVA-16. Marine mammal Brucella isolates were shown to be different from the recognized terrestrial mammal Brucella species and biovars and corresponded to 3 major related groups, one specific of the B. ceti strains, one of the B. pinnipedialis strains and the last composed of the human isolate. In the B. ceti group, 3 subclusters were identified, distinguishing a cluster of dolphin, minke whale and porpoise isolates and two clusters mostly composed of dolphin isolates. These results were in accordance with published analyses using other phenotypic or molecular approaches, or different panels of VNTR loci. The B. pinnipedialis group could be similarly subdivided in 3 subclusters, one composed exclusively of isolates from hooded seals (Cystophora cristata) and the two others comprising other seal species isolates. Conclusion The clustering analysis of a large collection of marine mammal Brucella isolates from European waters significantly strengthens the current view of the population structure of these two species, and their
Dietz, Stefanie; Mack, Sarah-Lena; Hoelzle, Katharina; Becker, Katja; Jannasch, Carolin; Stadler, Julia; Ritzmann, Mathias; Hoelzle, Ludwig E
The uncultivable hemotrophic bacterium Mycoplasma suis causes infectious anemia in pigs worldwide. The mechanisms by which M. suis is transmitted from pig to pig are largely unknown. Thus, the present study aimed at investigating urine, feces, saliva, nasal and vaginal secrets as well as environmental samples for the presence of M. suis DNA to get insights into potential transmission routes. Seven pigs were experimentally infected with M. suis KI3806. Samples were taken for 8 days post infection (p.i.). A quantitative LightCycler msg1 PCR was used to detect and quantify M. suis. Shedding was found in saliva as well as nasal and vaginal secrets from day 6 p.i. on with a quantity of 3.4 × 10(2) to 2.7 × 10(5)M. suis/swab. In urine M. suis DNA could be detected in 100.0% of the samples from day 6 p.i. on with a quantity of 4.7 × 10(2) to 6.3 × 10(5)M. suis per mL. When shedding patterns were correlated to the median bacterial blood loads shedding was observed at loads of 2.0 × 10(9)-7.0 × 10(10)M. suis per mL blood. No M. suis DNA could be amplified from feces. Dust and water samples of the pig drinking troughs were positive for M. suis on days 2 and 6 post infection, air samples were M. suis-negative throughout the experiment. Our results indicate that blood independent direct transmission as well as indirect transmission via environmental contamination could play a role in the epidemiology of M. suis infections.
Pei, Jianwu; Kahl-McDonagh, Melissa; Ficht, Thomas A
It has long been observed that smooth Brucella can dissociate into rough mutants that are cytotoxic to macrophages. However, the in vivo biological significance and/or mechanistic details of Brucella dissociation and cytotoxicity remain incomplete. In the current report, a plaque assay was developed using Brucella strains exhibiting varying degrees of cytotoxicity. Infected monolayers were observed daily using phase contrast microscopy for plaque formation while Brucella uptake and replication were monitored using an immunofluorescence assay (IFA). Visible plaques were detected at 4-5 days post infection (p.i.) with cytotoxic Brucella 16MΔmanBA at an MOI of 0.1. IFA staining demonstrated that the plaques consisted of macrophages with replicating Brucella. Visible plaques were not detected in monolayers infected with non-cytotoxic 16MΔmanBAΔvirB2 at an MOI of 0.1. However, IFA staining did reveal small groups of macrophages (foci) with replicating Brucella in the monolayers infected with 16MΔmanBAΔvirB2. The size of the foci observed in macrophage monolayers infected with rough Brucella correlated directly with cytotoxicity measured in liquid culture, suggesting that cytotoxicity was essential for Brucella egress and dissemination. In monolayers infected with 16M, small and large foci were observed. Double antibody staining revealed spontaneous rough mutants within the large, but not the small foci in 16M infected monolayers. Furthermore, plaque formation was observed in the large foci derived from 16M infections. Finally, the addition of gentamicin to the culture medium inhibited plaque formation, suggesting that cell-to-cell spread occurred only following release of the organisms from the cells. Taken together, these results demonstrate that Brucella-induced cytotoxicity is critical for Brucella egress and dissemination.
Moriyón, I; López-Goñi, I
The brucellae are Gram-negative bacteria characteristically able to multiply facultatively within phagocytic cells and which cause a zoonosis of world-wide importance. This article reviews the structure and topology of the main components (lipopolysaccharide, native hapten polysaccharide, free lipids and proteins) of the outer membranes of Brucella abortus and B. melitensis, as well as some distinctive properties (permeability and interactions with cationic peptides) of these membranes. On these data, an outer membrane model is proposed in which, as compared to other Gram-negatives, there is a stronger hydrophobic anchorage for the lipopolysaccharide, free lipids, porin proteins and lipoproteins, and a reduced surface density of anionic groups, which could be partially or totally neutralized by ornithine lipids. This model accounts for the permeability of Brucella to hydrophobic permeants and for its resistance to the bactericidal oxygen-independent systems of phagocytes.
Bodur, Hürrem; Balaban, Neriman; Aksaray, Sebahat; Yetener, Vedat; Akinci, Esragül; Colpan, Aylin; Erbay, Ayse
41 Brucella strains isolated from blood and cerebrospinal fluid cultures were identified to species level and biotypes detected. All of the isolates were Brucella melitensis: 2 strains of B. melitensis biotype-1 and 39 strains of B. melitensis biotype-3. In vitro activities of these strains were detected by the E test method. According to the 90% minimal inhibitory concentration (MIC90) values, the most active agent was doxycycline (MIC90 0.064 microg/ml), followed by ciprofloxacin (MIC90 0.25 microg/ml), trimethoprim-sulfamethoxazole and ceftriaxone (MIC90 0.38 microg/ml). Rifampin exhibited the highest MIC90 value (0.75 microg/ml).
Chin, Yoon T; Krishnan, Monica; Burns, Phillipa; Qamruddin, Ahmed; Hasan, Ragheb; Dodgson, Andrew R
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.
Fiori, Pier Luigi; Mastrandrea, Scilla; Rappelli, Paola; Cappuccinelli, Piero
We report an outbreak of laboratory-acquired Brucella abortus infection originating in the accidental breakage of a centrifuge tube. A total of 12 laboratory workers were infected (attack rate of 31%), with an incubation time ranging from 6 weeks to 5 months. Antibody titers were evaluated weekly in all personnel exposed, allowing the diagnosis of the infection in most cases before the onset of clinical symptoms, so that specific therapy could be administrated. PMID:10790142
Bilici, Meki; Demir, Fikri; Yılmazer, Murat Muhtar; Bozkurt, Fatma; Tuzcu, Volkan
Background: The clinical spectrum of Brucella infection is quite diverse and characterized by multi-system involvement. Patients present with myocarditis, endocarditis, or pericarditis. Infective endocarditis is the most common cardiovascular complication in patients with brucellosis. Although conduction abnormalities are seen in cases with endocarditis, they are reported very rarely in the setting of cardiac Brucella infection. Case Report: An eight and a half-year-old male patient was referred to our clinic due to inadequate response to cotrimaxazole plus streptomycin treatment at the 15th day of admission. Although local hospital records on the patient showed a heart rate of 80 bpm, we determined a heart rate of 46 bpm. The electrocardiogram showed complete atrioventricular (AV) block. The average heart rate was determined as 48 bpm with 24-hour Holter electrocardiogram (ECG) monitoring. The echocardiographic examination showed normal-sized heart chambers and the absence of valvular involvement. An agglutination test for brucellosis was found to be positive with a titer of 1/320. High fever, arthralgia, and splenomegaly regressed following doxycycline plus rifampicin therapy, but there was no improvement in the AV block. A permanent pacemaker was implanted because of the detection of an average heart rate of 48 bpm. Conclusion: Because cardiac failure and rhythm abnormalities are reported in the course of Brucella infection and may be associated with significant outcomes, cases with brucellosis should be evaluated carefully in terms of cardiac involvement. This report aims to draw attention to complete AV block as an extremely rare complication of Brucella infection. PMID:27761286
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Brucella spp. serological reagents. 866.3085 Section 866.3085 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3085 Brucella...
... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Brucella spp. serological reagents. 866.3085 Section 866.3085 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3085 Brucella...
... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Brucella spp. serological reagents. 866.3085 Section 866.3085 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3085 Brucella...
... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Brucella spp. serological reagents. 866.3085 Section 866.3085 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3085 Brucella...
... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Brucella spp. serological reagents. 866.3085 Section 866.3085 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3085 Brucella...
Although Brucella spp. are known for causing reproductive losses in domestic livestock, they are also capable of infecting humans and causing clinical disease. Human infection with Brucella is almost exclusively a result of direct contact with infected animals or consumption of products made from un...
Zheng, Chengkun; Xu, Jiali; Shi, Guolin; Zhao, Xigong; Ren, Sujing; Li, Jinquan; Chen, Huanchun; Bei, Weicheng
Streptococcus suis is an emerging zoonotic pathogen that causes severe infections in pigs and humans. However, the pathogenesis of S. suis remains unclear. The present study targeted a putative virulence-associated factor (fhs, encoding the formate-tetrahydrofolate ligase) of S. suis. To investigate the role of fhs in the virulence potential of S. suis serotype 2, an fhs deletion mutant (Δfhs) and the corresponding complementation strain (CΔfhs) were generated. The Δfhs mutant displayed similar growth compared to that of the wild-type and complementation strains. Using murine and pig infection models, we demonstrated for the first time that the formate-tetrahydrofolate ligase is required for the full virulence of S. suis 2. Our findings provide a new insight into the pathogenesis of S. suis 2.
Chang, Bin; Wada, Akihito; Ikebe, Tadayoshi; Ohnishi, Makoto; Mita, Kazuhito; Endo, Miyoko; Matsuo, Hirosuke; Asatuma, Yoshinori; Kuramoto, Sanae; Sekiguchi, Hiroshi; Yamazaki, Motoyosi; Yoshikawa, Hiroko; Watabe, Nobuei; Yamada, Hideko; Kurita, Shohachi; Imai, Yumiko; Watanabe, Haruo
Seven cases of Streptococcus suis infection in Japan during 1994 and 2006 were summarized. All cases had porcine exposure and five of them had hand skin injury during the exposure. Five cases presented symptoms of meningitis, three presented symptoms of sepsis, and one resulted in sudden death. All of the isolated S. suis belonged to Lancefield's group D and to serotype 2. They were susceptible to penicillin G, ampicillin, cefotaxime, and ciprofloxacin. However, six of them were resistant to both erythromycin and clindamycin, and four were also resistant to minocycline. Multilocus sequence typing of six isolates showed that they belonged to sequence type (ST) 1, and their pulsed-field gel electrophoresis (PFGE) patterns were similar. The remaining isolate was ST28 and its PFGE pattern was distinct from those of the others.
Wang, Yang; Li, Dexi; Song, Li; Liu, Yang; He, Tao; Liu, Hebing; Wu, Congming
The multiresistance gene cfr was identified for the first time in streptococci, namely, in porcine Streptococcus suis isolate S10. The cfr gene was detected on the ∼100-kb plasmid pStrcfr, where it was bracketed by two copies of the novel insertion sequence ISEnfa5, located in the same orientation. The detection of a cfr- and ISEnfa5-containing amplicon by inverse PCR suggests that ISEnfa5 may play a role in the dissemination of cfr. PMID:23733472
Schnell, Martin W
Self care is an answer to the response of finiteness, which is given through the fact of the human body. The article demonstrates in reference to the Selfcaredeficit-Theory (Orem, 2006) how self care in everyday life, ancient roman called it cura sui, is related to nursing practice, specially to acutecare. Self care turns out as an category of ambivalence between ethics and power.
Sidamonidze, Ketevan; Hang, Jun; Yang, Yu; Dzavashvili, George; Zhgenti, Ekaterine; Trapaidze, Nino; Imnadze, Paata
ABSTRACT Brucellosis, which is among the most widespread global zoonotic diseases, is endemic in the nation of Georgia and causes substantial human morbidity and economic loss. Here, we report whole-genome sequences of three Brucella melitensis and seven Brucella abortus isolates from cattle, sheep, and humans that represent genetic groups discovered in Georgia. PMID:28183751
McCready, Paula M.; Radnedge, Lyndsay; Andersen, Gary L.; Ott, Linda L.; Slezak, Thomas R.; Kuczmarski, Thomas A.
Nucleotide sequences specific to Brucella that serves as a marker or signature for identification of this bacterium were identified. In addition, forward and reverse primers and hybridization probes derived from these nucleotide sequences that are used in nucleotide detection methods to detect the presence of the bacterium are disclosed.
De Massis, Fabrizio; Garofolo, Giuliano; Cammà, Cesare; Ippoliti, Carla; Candeloro, Luca; Ancora, Massimo; Calistri, Paolo
The genetic diversity of Brucella melitensis and Brucella abortus strains isolated in 199 cattle and sheep from 156 brucellosis outbreaks which occurred in 8 regions of Southern Italy in 2011, was determined using a Multiple-Locus Variable Number of Tandem Repeats Analysis approach. The existence of possible genetic clusters was verified through a hierarchical cluster analysis based on 'single link', which is closely related to the minimum spanning tree. The Hamming weighted distance matrix was adopted in the analysis. All calculations were performed using R and the additional libraries phangorn and Cluster. For a number of clusters, ranging from 2 to 15, the average silhouette width was calculated. The number of clusters adopted was identified according to the maximum average silhouette width. For B. abortus and B. melitensis, 6 and 11 genetic clusters were identified, respectively. Three out of 6 B. abortus clusters included the 96.7% of all B. abortus isolates. Clusters were clearly geographically separated, and this highlighted the known epidemiological links among them. Brucella melitensis genotypes resulted more heterogeneous; the 3 more representative genetic clusters included 79.7% of all B. melitensis isolates. A clear geographical clusterization of genotypes is recognizable only for 1 cluster, whereas the others are more widespread across Southern Italy. The genetic characterization of Brucella strains isolated from animals may be a useful tool to better understand the epidemiology and dissemination patterns of this pathogen through host populations.
Eskra, Linda; Covert, Jill; Glasner, Jeremy; Splitter, Gary
Brucella spp. cause chronic zoonotic disease often affecting individuals and animals in impoverished economic or public health conditions; however, these bacteria do not have obvious virulence factors. Restriction of iron availability to pathogens is an effective strategy of host defense. For brucellae, virulence depends on the ability to survive and replicate within the host cell where iron is an essential nutrient for the growth and survival of both mammalian and bacterial cells. Iron is a particularly scarce nutrient for bacteria with an intracellular lifestyle. Brucella melitensis and Brucella canis share ~99% of their genomes but differ in intracellular lifestyles. To identify differences, gene transcription of these two pathogens was examined during infection of murine macrophages and compared to broth grown bacteria. Transcriptome analysis of B. melitensis and B. canis revealed differences of genes involved in iron transport. Gene transcription of the TonB, enterobactin, and ferric anguibactin transport systems was increased in B. canis but not B. melitensis during infection of macrophages. The data suggest differences in iron requirements that may contribute to differences observed in the lifestyles of these closely related pathogens. The initial importance of iron for B. canis but not for B. melitensis helps elucidate differing intracellular survival strategies for two closely related bacteria and provides insight for controlling these pathogens.
Gilmer, Daniel B.; Schmitz, Jonathan E.; Thandar, Mya; Euler, Chad W.; Fischetti, Vincent A.
Streptococcus suis infects pigs worldwide and may be zoonotically transmitted to humans with a mortality rate of up to 20%. S. suis has been shown to develop in vitro resistance to the two leading drugs of choice, penicillin and gentamicin. Because of this, we have pursued an alternative therapy to treat these pathogens using bacteriophage lysins. The bacteriophage lysin PlySs2 is derived from an S. suis phage and displays potent lytic activity against most strains of that species including serotypes 2 and 9. At 64 μg/ml, PlySs2 reduced multiple serotypes of S. suis by 5 to 6-logs within 1 hour in vitro and exhibited a minimum inhibitory concentration (MIC) of 32 μg/ml for a S. suis serotype 2 strain and 64 μg/ml for a serotype 9 strain. Using a single 0.1-mg dose, the colonizing S. suis serotype 9 strain was reduced from the murine intranasal mucosa by >4 logs; a 0.1-mg dose of gentamicin reduced S. suis by <3-logs. A combination of 0.05 mg PlySs2 + 0.05 mg gentamicin reduced S. suis by >5-logs. While resistance to gentamicin was induced after systematically increasing levels of gentamicin in an S. suis culture, the same protocol resulted in no observable resistance to PlySs2. Thus, PlySs2 has both broad and high killing activity against multiple serotypes and strains of S. suis, making it a possible tool in the control and prevention of S. suis infections in pigs and humans. PMID:28046082
Liu, Ning; Wang, Lin; Sun, Changjiang; Yang, Li; Tang, Bin; Sun, Wanchun; Peng, Qisheng
Brucella DNA can be sensed by TLR9 on endosomal membrane and by cytosolic AIM2-inflammasome to induce proinflammatory cytokine production that contributes to partially activate innate immunity. Additionally, Brucella DNA has been identified to be able to act as a major bacterial component to induce type I IFN. However, the role of Brucella DNA in Brucella intracellular growth remains unknown. Here, we showed that stimulation with Brucella DNA promote macrophage activation in TLR9-dependent manner. Activated macrophages can suppresses wild type Brucella intracellular replication at early stage of infection via enhancing NO production. We also reported that activated macrophage promotes bactericidal function of macrophages infected with VirB-deficient Brucella at the early or late stage of infection. This study uncovers a novel function of Brucella DNA, which can help us further elucidate the mechanism of Brucella intracellular survival.
Agrawal, Neha; Mathew, Thomas; Vidyasagar, Sudha; Kudaravalli, Pujitha
Brucella endocarditis is a rare but a severe complication of brucellosis, observed in less than 2% of cases. It is the main cause responsible for up to 80% of deaths in brucellosis. Herein, we present a case of brucella endocarditis that developed on a native aortic valve, but presented to us with fever for several months and acute neurological symptoms. This case report signifies the importance of considering brucella endocarditis as one of the differentials in patients presenting with Pyrexia of Unknown Origin (PUO) and Central Nervous System (CNS) manifestations.
Ocholi, R A; Kwaga, J K P; Ajogi, I; Bale, J O O
Isolation of brucellae from aborted fetuses, hygroma fluids, milk and vaginal swabs obtained from aborting cattle, sheep, goats, pigs, and horses in Nigeria was carried out. A total of 25 isolates, obtained mainly from cattle, sheep and horses, were biotyped. All strains belonged to one species, Brucella abortus biovar 1. The epidemiological significance of this finding is discussed. Some preliminary observations on the zoonotic and public health implications of Brucella infection in Nigerian livestock are presented. A control programme involving improved management, animal movement restrictions, public health education and mass vaccination of animals is suggested.
Whatmore, Adrian M; Davison, Nicholas; Cloeckaert, Axel; Al Dahouk, Sascha; Zygmunt, Michel S; Brew, Simon D; Perrett, Lorraine L; Koylass, Mark S; Vergnaud, Gilles; Quance, Christine; Scholz, Holger C; Dick, Edward J; Hubbard, Gene; Schlabritz-Loutsevitch, Natalia E
Two Gram-negative, non-motile, non-spore-forming coccoid bacteria (strains F8/08-60(T) and F8/08-61) isolated from clinical specimens obtained from baboons (Papio spp.) that had delivered stillborn offspring were subjected to a polyphasic taxonomic study. On the basis of 16S rRNA gene sequence similarities, both strains, which possessed identical sequences, were assigned to the genus Brucella. This placement was confirmed by extended multilocus sequence analysis (MLSA), where both strains possessed identical sequences, and whole-genome sequencing of a representative isolate. All of the above analyses suggested that the two strains represent a novel lineage within the genus Brucella. The strains also possessed a unique profile when subjected to the phenotyping approach classically used to separate species of the genus Brucella, reacting only with Brucella A monospecific antiserum, being sensitive to the dyes thionin and fuchsin, being lysed by bacteriophage Wb, Bk2 and Fi phage at routine test dilution (RTD) but only partially sensitive to bacteriophage Tb, and with no requirement for CO2 and no production of H2S but strong urease activity. Biochemical profiling revealed a pattern of enzyme activity and metabolic capabilities distinct from existing species of the genus Brucella. Molecular analysis of the omp2 locus genes showed that both strains had a novel combination of two highly similar omp2b gene copies. The two strains shared a unique fingerprint profile of the multiple-copy Brucella-specific element IS711. Like MLSA, a multilocus variable number of tandem repeat analysis (MLVA) showed that the isolates clustered together very closely, but represent a distinct group within the genus Brucella. Isolates F8/08-60(T) and F8/08-61 could be distinguished clearly from all known species of the genus Brucella and their biovars by both phenotypic and molecular properties. Therefore, by applying the species concept for the genus Brucella suggested by the ICSP
Wang, Zhen; Wu, Qingmin
Brucella spp. are facultative intracellular bacteria that cause brucellosis, which is a globally occurring zoonotic disease that is characterized by abortion in domestic animals and undulant fever, arthritis, endocarditis, and meningitis in humans. There are currently no licensed vaccines against brucellosis for human use, and only a few licensed live Brucella vaccines are available for use in animals. However, the available animal vaccines may cause abortion and are associated with lower protection rates in animals and higher virulence in humans. Much research has been performed recently to develop novel Brucella vaccines for the prevention and control of animal brucellosis. This article discusses the approaches and strategies for novel live attenuated vaccine development.
Teng, Lin; Dong, Xingxing; Zhou, Yang; Li, Zhiwei; Deng, Limei; Chen, Huanchun; Wang, Xiaohong
ABSTRACT Streptococcus suis, a zoonotic bacterium found primarily in pigs, has been recognized recently as an emerging pathogen of humans. Herein, we describe the genome of Streptococcus suis strain SC19, a hypervirulent and vaccine candidate strain isolated from a pig amid the 2005 outbreak in China. PMID:28104658
The aim of the present study was to investigate parasite induced immune responses in pigs co-infected with Trichuris suis and Oesophagostomum dentatum as compared to mono-species infected pigs. T. suis is known to elicit a strong immune response leading to rapid expulsion, and a strong antagonistic ...
Haas, Bruno; Grenier, Daniel
Streptococcus suis, more particularly serotype 2, is a major swine pathogen and an emerging zoonotic agent worldwide that mainly causes meningitis, septicemia, endocarditis, and pneumonia. Although several potential virulence factors produced by S. suis have been identified in the last decade, the pathogenesis of S. suis infections is still not fully understood. In the present study, we showed that S. suis produces membrane vesicles (MVs) that range in diameter from 13 to 130 nm and that appear to be coated by capsular material. A proteomic analysis of the MVs revealed that they contain 46 proteins, 9 of which are considered as proven or suspected virulence factors. Biological assays confirmed that S. suis MVs possess active subtilisin-like protease (SspA) and DNase (SsnA). S. suis MVs degraded neutrophil extracellular traps, a property that may contribute to the ability of the bacterium to escape the host defense response. MVs also activated the nuclear factor-kappa B (NF-κB) signaling pathway in both monocytes and macrophages, inducing the secretion of pro-inflammatory cytokines, which may in turn contribute to increase the permeability of the blood brain barrier. The present study brought evidence that S. suis MVs may play a role as a virulence factor in the pathogenesis of S. suis infections, and given their composition be an excellent candidate for vaccine development. PMID:26110524
Aksoycan, N; Sağanak, I; Wells, G
The immune sera for Brettanomyces lambicus, B. claussenii, Debaryomyces hansenii and D. marama agglutinated Salmonella cholerae-suis (0:6(2), 7). The immune serum for S. cholerae-suis agglutinated B. lambicus, B. clausenni, D. hansenii and D. marama. Absorption and agglutination cross-tested demonstrated common antigen factor(s) in the tested yeasts and Salmonella 0:7 antigen.
Zhang, Rui-xian; Lu, Qin; Zhang, Wei; Zhang, Mu-qun
Although there were changes in measuring system of Sui dynasty, the measuring units of medicine, astronomy and music still remained unchanged. So there appeared two systems of measuring units. For medicine, the government of Tang dynasty followed the regulations of Sui dynasty in measuring system. Besides this, the measuring units of Qian and Fen also were also related to medicine.
Soler-Lloréns, Pedro F.; Quance, Chris R.; Lawhon, Sara D.; Stuber, Tod P.; Edwards, John F.; Ficht, Thomas A.; Robbe-Austerman, Suelee; O'Callaghan, David; Keriel, Anne
Brucella are highly infectious bacterial pathogens responsible for brucellosis, a frequent worldwide zoonosis. The Brucella genus has recently expanded from 6 to 11 species, all of which were associated with mammals; The natural host range recently expanded to amphibians after some reports of atypical strains from frogs. Here we describe the first in depth phenotypic and genetic characterization of a Brucella strains isolated from a frog. Strain B13-0095 was isolated from a Pac-Man frog (Ceratophyrus ornate) at a veterinary hospital in Texas and was initially misidentified as Ochrobactrum anthropi. We found that B13-0095 belongs to a group of early-diverging brucellae that includes Brucella inopinata strain BO1 and the B. inopinata-like strain BO2, with traits that depart significantly from those of the “classical” Brucella spp. Analysis of B13-0095 genome sequence revealed several specific features that suggest that this isolate represents an intermediate between a soil associated ancestor and the host adapted “classical” species. Like strain BO2, B13-0095 does not possess the genes required to produce the perosamine based LPS found in classical Brucella, but has a set of genes that could encode a rhamnose based O-antigen. Despite this, B13-0095 has a very fast intracellular replication rate in both epithelial cells and macrophages. Finally, another major finding in this study is the bacterial motility observed for strains B13-0095, BO1, and BO2, which is remarkable for this bacterial genus. This study thus highlights several novel characteristics in strains belonging to an emerging group within the Brucella genus. Accurate identification tools for such atypical Brucella isolates and careful evaluation of their zoonotic potential, are urgently required. PMID:27734009
Spink, Wesley W.
A special study was made of the problem of brucellosis due to Brucella melitensis in visits to Mexico City in 1948, to the FAO/WHO Brucellosis Centres at Montpellier (France), Florence (Italy), and Rijeka (Yugoslavia) in 1951, and to Spain in 1952. Br. melitensis infection in human beings causes more severe illness than Br. abortus infection. It develops primarily in rural communities living in close contact with goats and sheep; cattle and swine may also harbour the infection. In diagnosis, the agglutination test has proved the most satisfactory procedure; testing would be more uniformly reliable if a single antigen were used. Lack of funds and technical assistance have in many instances limited the bacteriological studies upon which a more definitive diagnosis of brucellosis depends. Antibiotics, Brucella vaccines, and colloidal preparations of gold and silver—used separately and in combination—have proved of varying therapeutic value, although response to antibiotics is less favourable than in cases of Br. abortus infection. While the drastic measures—involving the slaughter of about 10,000 sheep—taken in Slovenia, Yugoslavia, in the late 1940's, against an outbreak of brucellosis, is an inspiring example of how the disease can be eradicated, the removal of all diseased animals is rarely feasible economically. It is hoped that future research will reveal a practicable alternative in the immunization of sheep and goats against the disease. PMID:13106703
SPINK, W W
A special study was made of the problem of brucellosis due to Brucella melitensis in visits to Mexico City in 1948, to the FAO/WHO Brucellosis Centres at Montpellier (France), Florence (Italy), and Rijeka (Yugoslavia) in 1951, and to Spain in 1952. Br. melitensis infection in human beings causes more severe illness than Br. abortus infection. It develops primarily in rural communities living in close contact with goats and sheep; cattle and swine may also harbour the infection.In diagnosis, the agglutination test has proved the most satisfactory procedure; testing would be more uniformly reliable if a single antigen were used. Lack of funds and technical assistance have in many instances limited the bacteriological studies upon which a more definitive diagnosis of brucellosis depends.Antibiotics, Brucella vaccines, and colloidal preparations of gold and silver-used separately and in combination-have proved of varying therapeutic value, although response to antibiotics is less favourable than in cases of Br. abortus infection.While the drastic measures-involving the slaughter of about 10,000 sheep-taken in Slovenia, Yugoslavia, in the late 1940's, against an outbreak of brucellosis, is an inspiring example of how the disease can be eradicated, the removal of all diseased animals is rarely feasible economically. It is hoped that future research will reveal a practicable alternative in the immunization of sheep and goats against the disease.
Stadler, J; Jannasch, C; Mack, S L; Dietz, S; Zöls, S; Ritzmann, M; Hoelzle, K; Hoelzle, L E
Mycoplasma suis causes infectious anaemia in pigs (IAP), which can manifest in various degrees of severity depending on the virulence and the host's susceptibility. As M. suis cannot be cultured in vitro experimental infections of splenectomised animals play an essential role for pathogenesis research. The aim of the present study was to characterise the course of experimental infection using the highly virulent and red blood cell (RBC-) invasive M. suis strain KI3806, to compare the experimental course in splenectomised and non-splenectomised pigs and to correlate clinical and haematological parameters with M. suis blood loads. All infected splenectomised pigs (n=7) were PCR-positive 2 days post infection (DPI) with maximum mean bacterial loads of 1.61 × 10(10)M. suis/mL on 8 DPI. They developed severe anaemia and massive hypoglycaemia by 8 DPI and had to be euthanised preterm (until 8 DPI) without seroconversion. The non-splenectomised pigs (n=7) became PCR-positive within 23 DPI and reached a maximum mean M. suis load of 1.64 × 10(5)M. suis/mL on 8 DPI. They developed mild anaemia, massive skin alterations with petechiae and haemorrhagic diathesis and seroconverted within 35 DPI. The study demonstrated that experimental infection of splenectomised pigs with the highly virulent M. suis strain KI3806 induces a fulminant course of infection. In contrast, M. suis strain KI3806 induces a mild course of disease in non-splenectomised pigs, which resembles the situation in naturally infected pigs. Therefore, these infection models are valuable for future pathogenesis studies on acute and chronic M. suis infections.
Liu, Peng; Lv, Qingyu; Zeng, Xiaotao; jiang, Hua; Wang, Yanzi; Zheng, Xin; Zheng, Yuling; Li, Jianchun; Zhou, Xuyu; Jiang, Yongqiang
Streptococcus suis (S.suis) is an important emerging worldwide pig pathogen and zoonotic agent with rapid evolution of virulence and drug resistance. In this study, we wanted to investigate the effect of licochalcone A on growth and properties of Streptococcus suis. The antimicrobial activity of licochalcone A was tested by growth inhibition assay and the minimal inhibitory concentrations (MICs) also were determined. The effect of licochalcone A on S.suis biofilm formation was characterized by crystal violet staining. The effect of licochalcone A on suilysin secretion was evaluated by titration of hemolytic activity. To understand the antimicrobial effect, gene expression profile of S.suis treated by licochalcone A was analyzed by DNA microarray. Our results demonstrated that licochalcone A showed antimicrobial activity on S.suis with MICs of 4 µg/ml for S.suis serotype 2 strains and 8 µg/ml for S.suis serotype 7 strains. Biofilm formation was inhibited by 30–40% in the presence of licochalcone A (3 µg/ml) and suilysin secretion was also significantly inhibited in the presence of licochalcone A (1.5 µg/ml). The gene expression profile of S.suis in the presence of licochalcone A showed that 132 genes were differentially regulated, and we analyzed the regulated genes in the aspect of the bacterial cell cycle control. Among the deregulated genes, the genes responsible for the mass doubling was increased expression, but the genes responsible for DNA replication and cell division were inhibited the expression. So, we think the regulation of the cell cycle genes might provide a mechanistic understanding of licochalcone A mediated antimicrobial effect against S.suis. PMID:23935843
van Straten, Michael; Bardenstein, Svetlana; Keningswald, Gaby; Banai, Menachem
Brucellosis is a zoonotic disease that can cause severe illness in humans and considerable economic loss in the livestock industry. Although small ruminants are the preferential host for Brucella melitensis, this pathogen has emerged as a cause for Brucella outbreaks in cattle. S19 vaccination is implemented in many countries where B. abortus is endemic but its effectiveness against B. melitensis has not been validated. Here we show that vaccine effectiveness in preventing disease transmission between vaccinated and unvaccinated cohorts, as determined by seroconversion, was 87.2% (95% CI 69.5-94.6%). Furthermore, vaccination was associated with a reduced risk for abortion. Together, our data emphasize the role S19 vaccination could play in preventing B. melitensis outbreaks in areas where this pathogen is prevalent in small ruminant populations.
Muendo, Esther N; Mbatha, Peter M; Macharia, Joseph; Abdoel, Theresia H; Janszen, Paul V; Pastoor, Rob; Smits, Henk L
Brucella melitensis biovar 1 was isolated from bovine milk samples from a herd in central Kenya, and Brucella abortus biovar 3 was isolated from aborted fetus materials and vaginal discharge fluids from cattle in central and eastern provinces of Kenya. All infections including those with B. melitensis were in cattle with reproductive problems kept in mixed herds indicating that cross infection occurs from small ruminants. Multiple-locus variable-number tandem repeat analysis genotyping revealed a close molecular homology of the B. melitensis isolates with an isolate from Israel and a close homology of the B. abortus isolates with an isolate from Uganda indicating that these genotypes have a wide geographic distribution. Infection of cattle with B. melitensis may complicate the control of brucellosis in this country.
Apa, Hurşit; Devrim, Ilker; Memur, Seyma; Günay, Ilker; Gülfidan, Gamze; Celegen, Mehmet; Bayram, Nuri; Karaarslan, Utku; Bağ, Ozlem; Işgüder, Rana; Oztürk, Aysel; Inan, Seyhan; Unal, Nurrettin
Brucella infections have a wide spectrum of symptoms especially in children, making the diagnosis a complicated process. The gold standard for the final diagnosis for brucellosis is to identify the Brucella spp. isolated from blood or bone marrow cultures. The main purpose of this work was to evaluate the factors affecting the isolation of Brucella spp. from blood cultures. In our study, the ratio of fever, presence of hepatomegaly, and splenomegaly were found to be higher in the bacteremic group. In addition, C-reactive protein levels and liver function enzymes were found to be higher in the bacteremic group. In our opinion, while evaluating the febrile child with suspected Brucella infection, we highly recommend sampling blood cultures regardless of the history of previous antimicrobial therapy and duration of the symptoms.
Martirosyan, Anna; Moreno, Edgardo; Gorvel, Jean-Pierre
Brucella is an intracellular bacterial pathogen that causes abortion and infertility in mammals and leads to a debilitating febrile illness that can progress into a long lasting disease with severe complications in humans. Its virulence depends on survival and replication properties in host cells. In this review, we describe the stealthy strategy used by Brucella to escape recognition of the innate immunity and the means by which this bacterium evades intracellular destruction. We also discuss the development of adaptive immunity and its modulation during brucellosis that in course leads to chronic infections. Brucella has developed specific strategies to influence antigen presentation mediated by cells. There is increasing evidence that Brucella also modulates signaling events during host adaptive immune responses.
Bacteria of the genus Brucella are intracellular vacuolar pathogens of mammals that cause the worldwide zoonosis brucellosis, and reside within phagocytes of infected hosts to promote their survival, persistence and proliferation. These traits are essential to the bacterium's ability to cause disease and have been the subject of much investigation to gain an understanding of Brucella pathogenic mechanisms. Although the endoplasmic reticulum-derived nature of the Brucella replicative niche has been long known, major strides have recently been made in deciphering the molecular mechanisms of its biogenesis, including the identification of bacterial determinants and host cellular pathways involved in this process. Here I will review and discuss the most recent advances in our knowledge of Brucella intracellular pathogenesis, with an emphasis on bacterial exploitation of the host endoplasmic reticulum-associated functions, and how autophagy-related processes contribute to the bacterium's intracellular cycle.
Lacerda, Thais Lourdes Santos; Salcedo, Suzana Pinto; Gorvel, Jean-Pierre
For many Gram-negative bacteria, like Brucella, the type IV secretion system (T4SS) has a critical role in bacterial virulence. In Brucella, the VirB T4SS permits the injection of bacterial effectors inside host cells, leading to subversion of signaling pathways and favoring bacterial growth and pathogenesis. The virB operon promoter is tightly regulated by a combination of transcriptional activators and repressors that are expressed according to the environmental conditions encountered by Brucella. Recent advances have shed light on the Brucella T4SS regulatory mechanisms and also its substrates. Characterization of the targets and functions of these translocated effectors is underway and will help understand the role of the T4SS in the establishment of a replication niche inside host cells.
O'Hara, Todd M; Holcomb, Darce; Elzer, Philip; Estepp, Jessica; Perry, Quinesha; Hagius, Sue; Kirk, Cassandra
We report on the presence of specific antibodies to Brucella spp. and Yersinia enterocolitica in polar bears (Ursus maritimus) from northern Alaska (southern Beaufort Sea) during 2003-2006. Based on numerous known stressors (e.g., climate change and loss of sea ice habitat, contaminants), there is increased concern regarding the status of polar bears. Considering these changes, it is important to assess exposure to potentially pathogenic organisms and to improve understanding of transmission pathways. Brucella or specific antibodies to Brucella spp. has been reported in marine mammals. Various assays were used to elucidate the pathway or source of exposure (e.g., "marine" vs. "terrestrial" Brucella spp.) of northern Alaska polar bears to Brucella spp. The standard plate test (SPT) and the buffered Brucella antigen card test (BBA) were used for initial screening for antibodies specific to Brucella. We then evaluated positive reactors (presence of serum antibody specific for Brucella spp.) using immunoblots and competitive enzyme-linked immunosorbent assay (cELISA; based on pinniped-derived Brucella spp. antigen). Annual prevalence of antibody (BBA and SPT) for Brucella spp. ranged from 6.8% to 18.5% over 2003-2006, with an overall prevalence of 10.2%. Prevalence of Brucella spp. antibody did vary by age class. Western blot analyses indicated 17 samples were positive for Brucella spp. antibody; of these, 13 were negative by marine (pinniped) derived Brucella antigen cELISA and four were positive by marine cELISA. Of the four samples positive for Brucella antibody by marine cELISA, three cross-reacted with Y. enterocolitica and Brucella spp. (one sample was Brucella negative and Y. enterocolitica positive). It appears the polar bear antibody does not react with the antigens used on the marine cELISA assay, potentially indicating a terrestrial (nonpinniped) source of Brucella spp.
Garofolo, Giuliano; Di Giannatale, Elisabetta; De Massis, Fabrizio; Zilli, Katiuscia; Ancora, Massimo; Cammà, Cesare; Calistri, Paolo; Foster, Jeffrey T
Despite the eradication of brucellosis from most of Europe, the disease remains relatively common in a variety of livestock in southern European countries. It is therefore surprising that with such high prevalence rates, there have been few genetic characterizations of brucellosis outbreaks in this region. We conducted a genetic assessment of 206 isolates of Brucella abortus and B. melitensis from Italy using Variable Number Tandem Repeats (VNTRs). We determined genetic diversity and geographic distribution of these Brucella VNTR genotypes from 160 farms in eight regions of Southern Italy in a fine-scale analysis using 16 VNTR loci in a MLVA-16 methodology. In a broad scale analysis, we then used a reduced dataset of 11 VNTR loci (MLVA-11) to compare genotypes from Italy to a global database. In the 84 isolates of B. melitensis, there were 56 genotypes using MLVA-16; 43 of these genotypes were found only once. At a broad scale, 81 of these isolates were part of an Italian sub-group within the West Mediterranean group. One of the two B. melitensis isolates from a human patient shared the same genotype as a livestock isolate, suggesting a possible epidemiological connection. In 122 B. abortus isolates, there were 34 genotypes by MLVA-16; 16 of these genotypes were found only once. At a broad scale with MLVA-11, one genotype was predominant, comprising 77.8% of the isolates and was distributed throughout Southern Italy. These data on the current lineages of Brucella present in Italy should form the basis for epidemiological studies of Brucella throughout the country, while placing these strains in a global context.
Shevtsov, Alexandr; Ramanculov, Erlan; Shevtsova, Elena; Kairzhanova, Alma; Tarlykov, Pavel; Filipenko, Maxim; Dymova, Maya; Abisheva, Gulzada; Jailbekova, Aygul; Kamalova, Dinara; Chsherbakov, Andrei; Tulegenov, Samat; Akhmetova, Assel; Sytnik, Igor; Karibaev, Talgat; Mukanov, Kasim
Brucellosis is an endemic disease in Central Asia characterized by high infection rates in humans and animals. Currently, little is known about the genetic diversity of Brucella spp. circulating in the region, despite the high prevalence of brucellosis. This study aimed to analyze the genetic diversity of Brucella melitensis and Brucella abortus strains circulating in the Republic of Kazakhstan. We genotyped 128 B. melitensis and 124 B. abortus strains collected in regions with the highest prevalence of brucellosis. Genotyping was performed using multi-locus variable-number tandem-repeat analysis (MLVA). Analysis of a subset of 8 loci (MLVA-8) of 128 B. melitensis strains identified genotypes 42 (n=108), 43 (n=2), and 63 (n=19) related to the 'East Mediterranean' group. An MLVA-16 assay sorted 128 B. melitensis strains into 25 different genotypes. Excluding one variable locus, MLVA-15 of B. melitensis was distinct from strains originating in the Mediterranean region; however, 77% of them were identical to strains isolated in China. A minimum spanning tree for B. melitensis using MLVA-15 analysis clustered the local strains together with strains previously collected in China. MLVA-8 analysis of 124 B. abortus strains identified them as genotype 36, suggesting Eurasian distribution of this lineage. Complete MLVA-16 assay analysis clustered the strains into five genotypes, revealing little diversity of B. abortus when compared on the global scale. A minimum spanning tree for B. abortus obtained using MLVA-15 analysis clustered the 2 most prevalent genotypes (n=117) together with strains previously collected in China. Thus, MLVA analysis was used to characterize 252 strains of Brucella collected in Kazakhstan. The analysis revealed genetic homogeneity among the strains. Interestingly, identical MLVA-15 profiles were found in seemingly unrelated outbreaks in China, Turkey, and Kazakhstan. Further analysis is needed for better understanding of the epidemiology of
Dawson, Claire E; Stubberfield, Emma J; Perrett, Lorraine L; King, Amanda C; Whatmore, Adrian M; Bashiruddin, John B; Stack, Judy A; MacMillan, Alastair P
Background Bacteria of the genus Brucella are the causative organisms of brucellosis in animals and man. Previous characterisation of Brucella strains originating from marine mammals showed them to be distinct from the terrestrial species and likely to comprise one or more new taxa. Recently two new species comprising Brucella isolates from marine mammals, B. pinnipedialis and B. ceti, were validly published. Here we report on an extensive study of the molecular and phenotypic characteristics of marine mammal Brucella isolates and on how these characteristics relate to the newly described species. Results In this study, 102 isolates of Brucella originating from eleven species of marine mammals were characterised. Results obtained by analysis using the Infrequent Restriction Site (IRS)-Derivative PCR, PCR-RFLP of outer membrane protein genes (omp) and IS711 fingerprint profiles showed good consistency with isolates originating from cetaceans, corresponding to B. ceti, falling into two clusters. These correspond to isolates with either dolphins or porpoises as their preferred host. Isolates originating predominantly from seals, and corresponding to B. pinnipedialis, cluster separately on the basis of IS711 fingerprinting and other molecular approaches and can be further subdivided, with isolates from hooded seals comprising a distinct group. There was little correlation between phenotypic characteristics used in classical Brucella biotyping and these groups. Conclusion Molecular approaches are clearly valuable in the division of marine mammal Brucella into subtypes that correlate with apparent ecological divisions, whereas conventional bioyping is of less value. The data presented here confirm that there are significant subtypes within the newly described marine mammal Brucella species and add to a body of evidence that could lead to the recognition of additional species or sub-species within this group. PMID:19091076
Avila-Calderón, Eric Daniel; Lopez-Merino, Ahidé; Sriranganathan, Nammalwar; Boyle, Stephen M.; Contreras-Rodríguez, Araceli
Brucellosis is a worldwide zoonosis affecting animal and human health. In the last several decades, much research has been performed to develop safer Brucella vaccines to control the disease mainly in animals. Till now, no effective human vaccine is available. The aim of this paper is to review and discuss the importance of methodologies used to develop Brucella vaccines in pursuing this challenge. PMID:23862154
Martin-Mazuelos, E; Nogales, M C; Florez, C; Gómez-Mateos, J M; Lozano, F; Sanchez, A
We report on an outbreak of laboratory-acquired brucellosis involving four technicians working at a microbiology laboratory. All cases occurred in a period of 4 months. Blood cultures and the Rose Bengal test were positive for Brucella spp. in all cases. Microagglutination was positive for Brucella spp. at titers of between 1/40 and 1/160. All patients were cured after treatment. PMID:7989566
Goolab, Shivani; Roth, Robyn L.; van Heerden, Henriette; Crampton, Michael C.
Bacterial lipoproteins possess diverse structure and functionality, ranging from bacterial physiology to pathogenic processes. As such many lipoproteins, originating from Brucella are exploited as potential vaccines to countermeasure brucellosis infection in the host. These membrane proteins are translocated from the cytoplasm to the cell membrane where they are anchored peripherally by a multifaceted targeting mechanism. Although much research has focused on the identification and classification of Brucella lipoproteins and their potential use as vaccine candidates for the treatment of Brucellosis, the underlying route for the translocation of these lipoproteins to the outer surface of the Brucella (and other pathogens) outer membrane (OM) remains mostly unknown. This is partly due to the complexity of the organism and evasive tactics used to escape the host immune system, the variation in biological structure and activity of lipoproteins, combined with the complex nature of the translocation machinery. The biosynthetic pathway of Brucella lipoproteins involves a distinct secretion system aiding translocation from the cytoplasm, where they are modified by lipidation, sorted by the lipoprotein localization machinery pathway and thereafter equipped for export to the OM. Surface localized lipoproteins in Brucella may employ a lipoprotein flippase or the β-barrel assembly complex for translocation. This review provides an overview of the characterized Brucella OM proteins that form part of the OM, including a handful of other characterized bacterial lipoproteins and their mechanisms of translocation. Lipoprotein localization pathways in gram negative bacteria will be used as a model to identify gaps in Brucella lipoprotein localization and infer a potential pathway. Of particular interest are the dual topology lipoproteins identified in Escherichia coli and Haemophilus influenza. The localization and topology of these lipoproteins from other gram negative bacteria
Aydemir, Huseyin; Budak, Gokcen; Budak, Salih; Celik, Orcun; Yalbuzdag, Okan; Keles, Ibrahim
Brucellosis is a zoonotic disease that involved genitourinary system in 2-20% and most commonly cause single sided epididymo-orchitis. In our country Brucella is an endemic disease and causes serious and different diagnosis of acute scrotum and epididymo-orchitis. In this paper six cases of epididymo-orchitis cases which were resistant to classical treatment were discussed according to clinical and laboratory findings. We describe different types of presentation of Brucella epididymo-orchitis with diagnosis and treatment modalities.
de Bolle, Xavier; Letesson, Jean-Jacques; Gorvel, Jean-Pierre
A key determinant for intracellular pathogenic bacteria to ensure their virulence within host cells is their ability to bypass the endocytic pathway and to reach a safe niche of replication. In the case of Brucella, the bacterium targets the ER (endoplasmic reticulum) to create a replicating niche called the BCV (Brucella-containing vacuole). The ER is a suitable strategic place for pathogenic Brucella. Indeed, bacteria can be hidden from host cell defences to persist within the host, and they can take advantage of the membrane reservoir delivered by the ER to replicate. Interaction with the ER leads to the presence on the BCV of the GAPDH (glyceraldehyde-3-phosphate dehydrogenase) and the small GTPase Rab2 known to be located on secretory vesicles that traffic between the ER and the Golgi apparatus. GAPDH and the small GTPase Rab2 controls Brucella replication at late times post-infection. A specific interaction between the human small GTPase Rab2 and a Brucella spp. protein named RicA was identified. Altered kinetics of intracellular trafficking and faster proliferation of the Brucella abortus ΔricA mutant was observed compared with the wild-type strain. RicA is the first reported effector with a proposed function for B. abortus.
Casalinuovo, Francesco; Ciambrone, Lucia; Cacia, Antonio; Rippa, Paola
A study was conducted in order to evaluate the contamination by Brucella spp. of meat from animals slaughtered because they had resulted positive for brucellosis at some time during their life. After slaughter and before delivery to market outlets, swab samples were taken from 307 carcasses of infected animals: 40 cattle, 60 sheep and 207 goats. The swabs were subsequently analysed by means of polymerase chain reaction (PCR) tests. In addition, bacteriological tests were carried out on the lymph nodes and internal organs of the same animals. Brucella spp. was detected by means of PCR in 25/307 carcasses (8%): 1 bovine (2.5%), 9 sheep (15%) and 15 goats (7.2%) and was isolated by means of a cultural method in 136/307 carcasses (44%). Moreover, additional analysis, performed on lymph nodes from the same carcasses that had proved positive by PCR, allowed highlighting type 3 Brucella abortus in the bovine carcass and type 3 Brucella melitensis in the sheep and goat carcasses. The study shows that cattle, sheep and goats meat of animals slaughtered because they had tested positive for brucellosis may be contaminated by Brucella spp. As this could constitute a real risk of transmission to both butchery personnel and consumers, the meat of animals infected by Brucella spp. should be analysed before being marketed. In this respect, PCR technique performed on swabs proved to be more useful, practical and faster than the traditional bacteriological method. PMID:27853716
Casalinuovo, Francesco; Ciambrone, Lucia; Cacia, Antonio; Rippa, Paola
A study was conducted in order to evaluate the contamination by Brucella spp. of meat from animals slaughtered because they had resulted positive for brucellosis at some time during their life. After slaughter and before delivery to market outlets, swab samples were taken from 307 carcasses of infected animals: 40 cattle, 60 sheep and 207 goats. The swabs were subsequently analysed by means of polymerase chain reaction (PCR) tests. In addition, bacteriological tests were carried out on the lymph nodes and internal organs of the same animals. Brucella spp. was detected by means of PCR in 25/307 carcasses (8%): 1 bovine (2.5%), 9 sheep (15%) and 15 goats (7.2%) and was isolated by means of a cultural method in 136/307 carcasses (44%). Moreover, additional analysis, performed on lymph nodes from the same carcasses that had proved positive by PCR, allowed highlighting type 3 Brucella abortus in the bovine carcass and type 3 Brucella melitensis in the sheep and goat carcasses. The study shows that cattle, sheep and goats meat of animals slaughtered because they had tested positive for brucellosis may be contaminated by Brucella spp. As this could constitute a real risk of transmission to both butchery personnel and consumers, the meat of animals infected by Brucella spp. should be analysed before being marketed. In this respect, PCR technique performed on swabs proved to be more useful, practical and faster than the traditional bacteriological method.
Ke, Yuehua; Wang, Yufei; Li, Wengfeng; Chen, Zeliang
Brucella spp. are intracellular bacterial pathogens that cause infection in domestic and wild animals. They are often used as model organisms to study intracellular bacterial infections. Brucella VirB T4SS is a key virulence factor that plays important roles in mediating intracellular survival and manipulating host immune response to infection. In this review, we discuss the roles of Brucella VirB T4SS and 15 effectors that are proposed to be crucial for Brucella pathogenesis. VirB T4SS regulates the inflammation response and manipulates vesicle trafficking inside host cells. VirB T4SS also plays crucial roles in the inhibition of the host immune response and intracellular survival during infection. Here, we list the key molecular events in the intracellular life cycle of Brucella that are potentially targeted by the VirB T4SS effectors. Elucidating the functions of these effectors will help clarify the molecular role of T4SS during infection. Furthermore, studying the effectors secreted by Brucella spp. might provide insights into the mechanisms used by the bacteria to hijack the host signaling pathways and aid in the development of better vaccines and therapies against brucellosis. PMID:26528442
Ke, Yuehua; Wang, Yufei; Li, Wengfeng; Chen, Zeliang
Brucella spp. are intracellular bacterial pathogens that cause infection in domestic and wild animals. They are often used as model organisms to study intracellular bacterial infections. Brucella VirB T4SS is a key virulence factor that plays important roles in mediating intracellular survival and manipulating host immune response to infection. In this review, we discuss the roles of Brucella VirB T4SS and 15 effectors that are proposed to be crucial for Brucella pathogenesis. VirB T4SS regulates the inflammation response and manipulates vesicle trafficking inside host cells. VirB T4SS also plays crucial roles in the inhibition of the host immune response and intracellular survival during infection. Here, we list the key molecular events in the intracellular life cycle of Brucella that are potentially targeted by the VirB T4SS effectors. Elucidating the functions of these effectors will help clarify the molecular role of T4SS during infection. Furthermore, studying the effectors secreted by Brucella spp. might provide insights into the mechanisms used by the bacteria to hijack the host signaling pathways and aid in the development of better vaccines and therapies against brucellosis.
Hernández-Mora, Gabriela; Manire, Charles A.; González-Barrientos, Rocío; Barquero-Calvo, Elías; Guzmán-Verri, Caterina; Staggs, Lydia; Thompson, Rachel; Chaves-Olarte, Esteban; Moreno, Edgardo
Brucella ceti causes disease in Odontoceti. The absence of control serum collections and the diversity of cetaceans have hampered the standardization of serological tests for the diagnosis of cetacean brucellosis. Without a “gold” standard for sensitivity and specificity determination, an alternative approach was followed. We designed an indirect enzyme-linked immunosorbent assay (iELISA) that recognizes immunoglobulins G (IgGs) from 17 odontocete species as a single group. For the standardization, we used Brucella melitensis and Brucella abortus lipopolysaccharides, serum samples from seven resident odontocetes with no history of infectious disease displaying negative rose bengal test (RBT) reactions, and serum samples from seven dolphins infected with B. ceti. We compared the performance of the iELISA with those of the protein G ELISA (gELISA), the competitive ELISA (cELISA), and the immunofluorescence (IF) and dot blot (DB) tests, using 179 odontocete serum samples and RBT as the reference. The diagnostic potential based on sensitivity and specificity of the iELISA was superior to that of gELISA and cELISA. The correlation and agreement between the iELISA and the gELISA were relatively good (Ri/g2 = 0.65 and κi/g = 0.66, respectively), while the correlation and agreement of these two ELISAs with cELISA were low (Ri/c2 = 0.46, Rg/c2 = 0.37 and κi/c = 0.62, κg/c = 0.42). In spite of using the same anti-odontocete IgG antibody, the iELISA was more specific than were the IF and DB tests. An association between high antibody titers and the presence of neurological symptoms in dolphins was observed. The prediction is that iELISA based on broadly cross-reacting anti-dolphin IgG antibody would be a reliable test for the diagnosis of brucellosis in odontocetes, including families not covered in this study. PMID:19386800
Ferrando, Maria Laura; Schultsz, Constance
ABSTRACT Streptococcus suis (SS) is a zoonotic pathogen that can cause systemic infection in pigs and humans. The ingestion of contaminated pig meat is a well-established risk factor for zoonotic S. suis disease. In our studies, we provide experimental evidence that S. suis is capable to translocate across the host gastro-intestinal tract (GIT) using in vivo and in vitro models. Hence, S. suis should be considered an emerging foodborne pathogen. In this addendum, we give an overview of the complex interactions between S. suis and host-intestinal mucosa which depends on the host origin, the serotype and genotype of S. suis, as well as the presence and expression of virulence factors involved in host-pathogen interaction. Finally, we propose a hypothetical model of S. suis interaction with the host-GIT taking in account differences in conditions between the porcine and human host. PMID:26900998
Viana, Marcus Vinicius Canário; Wattam, Alice Rebecca; Govil Batra, Dhwani; Boisvert, Sébastien; Brettin, Thomas Scott; Frace, Michael; Xia, Fangfang; Azevedo, Vasco; Tiller, Rebekah; Hoffmaster, Alex R
Brucella canis is a facultative intracellular pathogen that preferentially infects members of the Canidae family. Here, we report the genome sequencing of two Brucella canis strains isolated from humans and one isolated from a dog host.
Viana, Marcus Vinicius Canário; Govil Batra, Dhwani; Boisvert, Sébastien; Brettin, Thomas Scott; Frace, Michael; Xia, Fangfang; Azevedo, Vasco; Tiller, Rebekah; Hoffmaster, Alex R.
ABSTRACT Brucella canis is a facultative intracellular pathogen that preferentially infects members of the Canidae family. Here, we report the genome sequencing of two Brucella canis strains isolated from humans and one isolated from a dog host. PMID:28232424
Rao, Sashi Bhushan; Gupta, Vivek K; Kumar, Mukesh; Hegde, Nagendra R; Splitter, Gary A; Reddanna, Pallu; Radhakrishnan, Girish K
Brucella spp. are facultative intracellular bacterial pathogens causing the zoonotic disease brucellosis. Here, we report the draft genome sequence of the Brucella melitensis strain from India designated Bm IND1, isolated from stomach contents of an aborted goat fetus.
Warneboldt, Franziska; Sander, Saara J.; Beineke, Andreas; Valentin-Weigand, Peter; Kamphues, Josef; Baums, Christoph Georg
Streptococcus (S.) suis translocates across the intestinal barrier of piglets after intraintestinal application. Based on these findings, an oro-gastrointestinal infection route has been proposed. Thus, the objective of this study was to investigate the survival of S. suis in the porcine stomach. Whereas surviving bacteria of S. suis serotypes 2 and 9 were not detectable after 60 min of incubation in stomach contents with a comparatively high gastric pH of 5 due to feeding of fine pellets, the number of Salmonella Derby bacteria increased under these conditions. Further experiments confirmed the clearance of S. suis serotypes 2 and 9 within 30 min in stomach contents with a pH of 4.7 independently of the bacterial growth phase. Finally, an oral infection experiment was conducted, feeding each of 18 piglets a diet mixed with 1010 CFU of S. suis serotype 2 or 9. Thorough bacteriological screenings of various mesenteric-intestinal lymph nodes and internal organs after different times of exposure did not lead to any detection of the orally applied challenge strains. In conclusion, the porcine stomach constitutes a very efficient barrier against oro-gastrointenstinal S. suis infections. Conditions leading to the passage of S. suis through the stomach remain to be identified. PMID:27509526
Lecours, Marie-Pier; Letendre, Corinne; Clarke, Damian; Lemire, Paul; Galbas, Tristan; Benoit-Biancamano, Marie-Odile; Thibodeau, Jacques; Gottschalk, Marcelo; Segura, Mariela
The pathogenesis of Streptococcus suis infection, a major swine and human pathogen, is only partially understood and knowledge on the host adaptive immune response is critically scarce. Yet, S. suis virulence factors, particularly its capsular polysaccharide (CPS), enable this bacterium to modulate dendritic cell (DC) functions and potentially impair the immune response. This study aimed to evaluate modulation of T cell activation during S. suis infection and the role of DCs in this response. S. suis-stimulated total mouse splenocytes readily produced TNF-α, IL-6, IFN-γ, CCL3, CXCL9, and IL-10. Ex vivo and in vivo analyses revealed the involvement of CD4+ T cells and a Th1 response. Nevertheless, during S. suis infection, levels of the Th1-derived cytokines TNF-α and IFN-γ were very low. A transient splenic depletion of CD4+ T cells and a poor memory response were also observed. Moreover, CD4+ T cells secreted IL-10 and failed to up-regulate optimal levels of CD40L and CD69 in coculture with DCs. The CPS hampered release of several T cell-derived cytokines in vitro. Finally, a correlation was established between severe clinical signs of S. suis disease and impaired antibody responses. Altogether, these results suggest S. suis interferes with the adaptive immune response. PMID:27905502
Warneboldt, Franziska; Sander, Saara J; Beineke, Andreas; Valentin-Weigand, Peter; Kamphues, Josef; Baums, Christoph Georg
Streptococcus (S.) suis translocates across the intestinal barrier of piglets after intraintestinal application. Based on these findings, an oro-gastrointestinal infection route has been proposed. Thus, the objective of this study was to investigate the survival of S. suis in the porcine stomach. Whereas surviving bacteria of S. suis serotypes 2 and 9 were not detectable after 60 min of incubation in stomach contents with a comparatively high gastric pH of 5 due to feeding of fine pellets, the number of Salmonella Derby bacteria increased under these conditions. Further experiments confirmed the clearance of S. suis serotypes 2 and 9 within 30 min in stomach contents with a pH of 4.7 independently of the bacterial growth phase. Finally, an oral infection experiment was conducted, feeding each of 18 piglets a diet mixed with 10(10) CFU of S. suis serotype 2 or 9. Thorough bacteriological screenings of various mesenteric-intestinal lymph nodes and internal organs after different times of exposure did not lead to any detection of the orally applied challenge strains. In conclusion, the porcine stomach constitutes a very efficient barrier against oro-gastrointenstinal S. suis infections. Conditions leading to the passage of S. suis through the stomach remain to be identified.
Yang, Yan-Bei; Wang, Shuai; Wang, Chang; Huang, Quan-Yong; Bai, Jing-Wen; Chen, Jian-Qing; Chen, Xue-Ying; Li, Yan-Hua
Streptococcus suis (S. suis) is a swine pathogen and also a zoonotic agent. In this study, the effects of subinhibitory concentrations (sub-MICs) of emodin on biofilm formation by S. suis ATCC700794 were evaluated. As quantified by crystal violet staining, biofilm formation by S. suis ATCC700794 was dose-dependently decreased after growth with 1/2 MIC, 1/4 MIC, or 1/8 MIC of emodin. By scanning electron microscopy, the structural architecture of the S. suis ATCC700794 biofilms was examined following growth in culture medium supplemented with 1/2 MIC, 1/4 MIC, 1/8 MIC, or 1/16 MIC of emodin. Scanning electron microscopy analysis revealed the potential effect of emodin on biofilm formation by S. suis ATCC700794. The expression of luxS gene and virulence genes in S. suis ATCC700794 was investigated by quantitative RT-PCR. It was found that sub-MICs of emodin significantly decreased the expression of gapdh, sly, fbps, ef, and luxS. However, it was found that sub-MICs of emodin significantly increased the expression of cps2J, mrp, and gdh. These findings showed that sub-MICs of emodin could cause the difference in the expression level of the virulence genes.
Wang, Shuai; Yang, Yanbei; Zhao, Yulin; Zhao, Honghai; Bai, Jingwen; Chen, Jianqing; Zhou, Yonghui; Wang, Chang; Li, Yanhua
Streptococcus suis (S.suis) is an important zoonotic pathogen that causes severe diseases in humans and pigs. Biofilms of S. suis can induce persistent infections that are difficult to treat. In this study, the effect of tylosin on biofilm formation of S. suis was investigated. 1/2 minimal inhibitory concentration (MIC) and 1/4 MIC of tylosin were shown to inhibit S. suis biofilm formation in vitro. By using the iTRAQ strategy, we compared the protein expression profiles of S. suis grown with sub-MIC tylosin treatment and with no treatment. A total of 1501 proteins were identified by iTRAQ. Ninety-six differentially expressed proteins were identified (Ratio > ±1.5, p < 0.05). Several metabolism proteins (such as phosphoglycerate kinase) and surface proteins (such as ABC transporter proteins) were found to be involved in biofilm formation. Our results indicated that S. suis metabolic regulation, cell surface proteins, and virulence proteins appear to be of importance in biofilm growth with sub-MIC tylosin treatment. Thus, our data revealed the rough regulation of biofilm formation that may provide a foundation for future research into mechanisms and targets.
Wang, Shuai; Yang, Yanbei; Zhao, Yulin; Zhao, Honghai; Bai, Jingwen; Chen, Jianqing; Zhou, Yonghui; Wang, Chang; Li, Yanhua
Streptococcus suis (S.suis) is an important zoonotic pathogen that causes severe diseases in humans and pigs. Biofilms of S. suis can induce persistent infections that are difficult to treat. In this study, the effect of tylosin on biofilm formation of S. suis was investigated. 1/2 minimal inhibitory concentration (MIC) and 1/4 MIC of tylosin were shown to inhibit S. suis biofilm formation in vitro. By using the iTRAQ strategy, we compared the protein expression profiles of S. suis grown with sub-MIC tylosin treatment and with no treatment. A total of 1501 proteins were identified by iTRAQ. Ninety-six differentially expressed proteins were identified (Ratio > ±1.5, p < 0.05). Several metabolism proteins (such as phosphoglycerate kinase) and surface proteins (such as ABC transporter proteins) were found to be involved in biofilm formation. Our results indicated that S. suis metabolic regulation, cell surface proteins, and virulence proteins appear to be of importance in biofilm growth with sub-MIC tylosin treatment. Thus, our data revealed the rough regulation of biofilm formation that may provide a foundation for future research into mechanisms and targets. PMID:27065957
Schreiner, Sabrina A; Hoelzle, Katharina; Hofmann-Lehmann, Regina; Hamburger, Anja; Wittenbrink, Max M; Kramer, Manuela M; Sokoli, Albina; Felder, Kathrin M; Groebel, Katrin; Hoelzle, Ludwig E
Mycoplasma suis belongs to haemotrophic mycoplasmas (HMs) which cause infectious anaemia in a large variety of mammals. To date, no in vitro cultivation system for M. suis or other HMs has been established. We hypothesised that M. suis could grow in classical Mycoplasma media supplemented with nutrients (e.g. glucose, iron-binding proteins) which are naturally available from its host environment, the porcine blood. Blood from experimentally M. suis-infected pigs was used to inoculate either standard SP-4 Mycoplasma medium supplemented with iron-binding proteins (transferrin, haemin, and haemoglobin) or glucose-enriched Hayflick Mycoplasma medium. A quantitative M. suis-specific real-time PCR assay was applied to determine and quantify M. suis loads weekly during 12 week-incubation. The first 2 weeks after inoculation M. suis loads decreased remarkably and then persisted at a stationary level over the observation time of 12 weeks in iron-binding protein- or glucose supplemented media variants. Scanning electron microscopic analysis of liquid M. suis sub-cultures on Hayflick agar showed small, densely-packed microcolonies of irregular M. suis cells of reduced size (0.2-0.6μm) indicating nanotransformation. The partial 16S rDNA sequence of these cultured M. suis nanocells was 99.9% identical to M. suis. M. suis cells derived from liquid cultures interact in vitro with porcine erythrocytes by fibril-like structures. We conclude, that the modified Mycoplasma media used for M. suis cultivation are obviously unfavourable for growth but lead to culture persistence. M. suis adapt to inappropriate culture conditions by alteration into nanoforms.
Background Streptococcus suis serotype 2 (S. suis 2) is an important pathogen of pigs. S suis 2 infections have high mortality rates and are characterized by meningitis, septicemia and pneumonia. S. suis 2 is also an emerging zoonotic agent and can infect humans that are exposed to pigs or their by-products. To increase our knowledge of the pathogenesis of meningitis, septicemia and pneumonia in pigs caused by S. suis 2, we profiled the response of peripheral blood mononuclear cells (PBMC), brain and lung tissues to infection with S. suis 2 strain SC19 using the Affymetrix Porcine Genome Array. Results A total of 3,002 differentially expressed transcripts were identified in the three tissues, including 417 unique genes in brain, 210 in lung and 213 in PBMC. These genes showed differential expression (DE) patterns on analysis by visualization and integrated discovery (DAVID). The DE genes involved in the immune response included genes related to the inflammatory response (CD163), the innate immune response (TLR2, TLR4, MYD88, TIRAP), cell adhesion (CD34, SELE, SELL, SELP, ICAM-1, ICAM-2, VCAM-1), antigen processing and presentation (MHC protein complex) and angiogenesis (VEGF), together with genes encoding cytokines (interleukins). Five selected genes were validated by qRT-PCR analysis. Conclusions We studied the response to infection with S. suis 2 strain SC19 by microarray analysis. Our findings confirmed some genes identified in previous studies and discovered numerous additional genes that potentially function in S. suis 2 infections in vivo. This new information will form the foundation of future investigations into the pathogenesis of S. suis. PMID:21599948
Mayfield, J.E.; Tabatabai, L.B.
This patent describes a synthetic recombinant DNA molecule containing a DNA sequence. It comprises a gene of Brucella abortus encoding an immunogenic protein having a molecular weight of approximately 31,000 daltons as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis under denaturing conditions, the protein having an isoelectric point around 4.9, and containing a twenty-five amino acid sequence from its amino terminal end consisting of Gln-Ala-Pro-Thr-Phe-Phe-Arg-Ile-Gly-Thr-Gly-Gly-Thr-Ala-Gly-Thr-Tyr-Tyr-Pro-Ile-Gly-Gly-Leu-Ile-Ala, wherein Gln, Ala, Pro, Thr, Phe, Arg, Ile, Gly, Tyr, and Leu, respectively, represent glutamine, alanine, proline, threonine, phenylalanine, arginine, isolecuine, glycine, tyrosine, and leucine.
Polat, K Y; Tosun, M S; Ertekin, V; Aydinli, B; Emre, S
Brucellosis is considered the most widespread zoonosis in the world. It has been reported that the prevalence of seropositivity among the Turkish population varies from 3% to 14%. We present a case of brucellosis after pediatric liver transplantation. A 15-year-old boy with the diagnosis of neuro Wilson's disease underwent deceased-donor liver transplantation. The postoperative immunosuppressive protocol consisted of steroids and tacrolimus. Two months after the operation the patient experienced fever to 40°C. The patient complained of poor appetite, headache, and diarrhea. He had had pancytopenia. Despite administration of appropriate antibiotics, antiviral and antifungal agents, fever persisted for > 1 month. Multiple blood, urine, stool, and sputum cultures were negative. Bone marrow aspirate revealed hypocellularity. Liver biopsy was performed, but rejection was not observed on biopsy specimen. Brucella serology was positive and Brucella agglutination titer was 1:320. Bone marrow culture was positive for Brucella but blood culture was negative. The patient was then treated with oral doxycycline and rifampin for 8 weeks. No previous case report about Brucella infection after liver transplantation has appeared in the literature, to our knowledge; our case is presented as the first. Bone marrow hypoplasia is a rare feature of Brucella infection. Our patient with brucellosis and pancytopenia had had hypocellular bone marrow. The clinical and hematologic findings resolved with treatment of the infection. Brucella infection should be suspected in liver transplanted recipients with fever of unknown origin, especially in a recipient who has lived in an endemic area. Brucella also should be considered as a possible diagnosis in patients with pancytopenia.
Ferreira, Ana Cristina; Chambel, Lélia; Tenreiro, Tania; Cardoso, Regina; Flor, Lídia; Dias, Isabel Travassos; Pacheco, Teresa; Garin-Bastuji, Bruno; Le Flèche, Philippe; Vergnaud, Gilles; Tenreiro, Rogério; de Sá, Maria Inácia Corrêa
To investigate the epidemiological relationship of isolates from different Portuguese geographical regions and to assess the diversity among isolates, the MLVA16Orsay assay (panels 1, 2A and 2B) was performed with a collection of 126 Brucella melitensis (46 human and 80 animal isolates) and 157 B. abortus field isolates, seven vaccine strains and the representative reference strains of each species. The MLVA16Orsay showed a similar high discriminatory power (HGDI 0.972 and 0.902) for both species but panel 1 and 2A markers displayed higher diversity (HGDI 0.693) in B. abortus compared to B. melitensis isolates (HGDI 0.342). The B. melitensis population belong to the “Americas” (17%) and “East Mediterranean” (83%) groups. No isolate belonged to the “West Mediterranean” group. Eighty-five percent of the human isolates (39 in 46) fit in the “East-Mediterranean” group where a single lineage known as MLVA11 genotype 116 is responsible for the vast majority of Brucella infections in humans. B. abortus isolates formed a consistent group with bv1 and bv3 isolates in different clusters. Four MLVA11 genotypes were observed for the first time in isolates from S. Jorge and Terceira islands from Azores. From the collection of isolates analysed in this study we conclude that MLVA16Orsay provided a clear view of Brucella spp. population, confirming epidemiological linkage in outbreak investigations. In particular, it suggests recent and ongoing colonisation of Portugal with one B. melitensis lineage usually associated with East Mediterranean countries. PMID:22905141
Risco, David; Fernández-Llario, Pedro; Cuesta, Jesús M; García-Jiménez, Waldo L; Gonçalves, Pilar; Martínez, Remigio; García, Alfredo; Rosales, Rubén; Gómez, Luis; de Mendoza, Javier Hermoso
Streptococcus suis is a recognized pathogen that may cause important diseases in pigs and humans. This microorganism has been repeatedly isolated from wild boar (Sus scrofa). However, its health implications for this wild species are still unknown. This article reports a detailed description of a fatal case of septicemia by S. suis affecting a young wild boar. The affected animal, about 15 days old, was found near death and exhibiting neurologic signs at a wild boar estate in southwestern Spain. Postmortem examination showed generalized congestion, brain hemorrhages and lobular pneumonia. Histopathological evaluation demonstrated the presence of meningitis and encephalitis with marked congestion and suppurative bronchopneumonia. Streptococcus suis serotype 2 isolates exhibiting important virulence factors (extracellular factor, muramidase-released protein, and suylisin) were isolated from the affected animal. This study confirms the presence of potentially virulent and zoonotic strains of S. suis in wild boar from Spain.
Petersen, Erik; Rajashekara, Gireesh; Sanakkayala, Neelima; Eskra, Linda; Harms, Jerome; Splitter, Gary
Erythritol is a four-carbon sugar preferentially utilized by Brucella spp. The presence of erythritol in the placentas of goats, cows, and pigs has been used to explain the localization of Brucella to these sites and the subsequent accumulation of large amounts of bacteria, eventually leading to abortion. Here we show that Brucella melitensis will also localize to an artificial site of erythritol within a mouse, providing a potential model system to study the pathogenesis of Brucella abortion. Immunohistological staining of the sites of erythritol within infected mice indicated a higher than expected proportion of extracellular bacteria. Ensuing experiments suggested intracellular B. melitensis was unable to replicate within macrophages in the presence of erythritol and that erythritol was able to reach the site of intracellular bacteria. The intracellular inhibition of growth was found to encourage the bacteria to replicate extracellularly rather than intracellularly, a particularly interesting development in Brucella pathogenesis. To determine the effect of erythritol on expression of B. melitensis genes, bacteria grown either with or without erythritol were analyzed by microarray. Two major virulence pathways were up-regulated in response to exposure to erythritol (the type IV secretion system VirB and flagellar proteins), suggesting a role for erythritol in virulence.
Zhao, Zhongpeng; Yan, Fang; Ji, Wenhui; Luo, Deyan; Liu, Xin; Xing, Li; Duan, Yueqiang; Yang, Penghui; Shi, Xiumin; Lu, Zhong; Wang, Xiliang
Infection with Brucella causes brucellosis, a chronic disease in humans, which induces abortion and sterility in livestock. Among the different Brucella species, Brucella melitensis is considered the most virulent and is the predominant species associated with outbreaks in China. To date, no safe human vaccine is available against Brucella infection. The currently used live vaccines against Brucella in livestock induce antibodies that interfere with the diagnosis of field infection in vaccinated animals, which is harmful to eradication programs. However, there is as yet no complete profile of immunogenic proteins of B. melitensis. Towards the development of a safer, equally efficacious, and field infection-distinguishable vaccine, we used immunoproteomics to identify novel candidate immunogenic proteins from B. melitensis M5. Eighty-eight immunoreactive protein spots from B. melitensis M5 were identified by Western blotting and were assigned to sixty-one proteins by mass spectrometry, including many new immunoreactive proteins such as elongation factor G, F0F1 ATP synthase subunit beta, and OMP1. These provide many candidate immunoreactive proteins for vaccine development.
Terwagne, Matthieu; Ferooz, Jonathan; Rolán, Hortensia G; Sun, Yao-Hui; Atluri, Vidya; Xavier, Mariana N; Franchi, Luigi; Núñez, Gabriel; Legrand, Thomas; Flavell, Richard A; De Bolle, Xavier; Letesson, Jean-Jacques; Tsolis, Renée M
Brucella are facultative intracellular bacteria that cause chronic infections by limiting innate immune recognition. It is currently unknown whether Brucella FliC flagellin, the monomeric subunit of flagellar filament, is sensed by the host during infection. Here, we used two mutants of Brucella melitensis, either lacking or overexpressing flagellin, to show that FliC hinders bacterial replication in vivo. The use of cells and mice genetically deficient for different components of inflammasomes suggested that FliC was a target of the cytosolic innate immune receptor NLRC4 in vivo but not in macrophages in vitro where the response to FliC was nevertheless dependent on the cytosolic adaptor ASC, therefore suggesting a new pathway of cytosolic flagellin sensing. However, our work also suggested that the lack of TLR5 activity of Brucella flagellin and the regulation of its synthesis and/or delivery into host cells are both part of the stealthy strategy of Brucella towards the innate immune system. Nevertheless, as a flagellin-deficient mutant of B. melitensis wasfound to cause histologically demonstrable injuries in the spleen of infected mice, we suggested that recognition of FliC plays a role in the immunological stand-off between Brucella and its host, which is characterized by a persistent infection with limited inflammatory pathology.
Petersen, Heidi Huus; Andreasen, Annette; Kringel, Helene; Roepstorff, Allan; Thamsborg, Stig M
The aim of the present study was to investigate the population dynamics and potential interactions between Trichuris suis and Oesophagostomum dentatum in experimentally co-infected pigs, by quantification of parasite parameters such as egg excretion, worm recovery and worm location. Forty-eight helminth naïve pigs were allocated into four groups. Group O was inoculated with 20 O. dentatum L3/kg/day and Group T with 10 T. suis eggs/kg/day. Group OT was inoculated with both 20 O. dentatum L3/kg/day and 10 T. suis eggs/kg/day, while Group C was kept as an uninfected control group. All inoculations were trickle infections administered twice weekly and were continued until slaughter. Faecal samples were collected from the rectum of all pigs at day 0, and twice weekly from 2 to 9 weeks post first infection (wpi). Six pigs from each group were necropsied 5 wpi and the remaining 6 pigs from each group were necropsied 10 wpi. The faecal egg counts (FEC) and total worm burdens of O. dentatum were dramatically influenced by the presence of T. suis, with significantly lower mean FECs and worm burdens at 5 and 10 wpi compared to single infected pigs. Furthermore, in the presence of T. suis we found that O. dentatum was located more posteriorly in the gut. The changes in the Trichuris population were less prominent, but faecal egg counts, worm counts 5 wpi (57% recovered vs. 39%) and the proportion of infected animals at 10 wpi were higher in Group OT compared to Group T. The location of T. suis was unaffected by the presence of O. dentatum. These results indicate an antagonistic interaction between T. suis and O. dentatum which is dominated by T. suis.
Lebel, Geneviève; Piché, Fanny; Frenette, Michel; Gottschalk, Marcelo; Grenier, Daniel
Streptococcus suis serotype 2 is known to cause severe infections in pigs, including meningitis, endocarditis and pneumonia. Furthermore, this bacterium is considered an emerging zoonotic agent. Recently, increased antibiotic resistance in S. suis has been reported worldwide. The objective of this study was to evaluate the potential of nisin, a bacteriocin of the lantibiotic class, as an antibacterial agent against the pathogen S. suis serotype 2. In addition, the synergistic activity of nisin in combination with conventional antibiotics was assessed. Using a plate assay, the nisin-producing strain Lactococcus lactis ATCC 11454 proved to be capable of inhibiting the growth of S. suis (n=18) belonging to either sequence type (ST)1, ST25, or ST28. In a microdilution broth assay, the minimum inhibitory concentration (MIC) of purified nisin ranged between 1.25 and 5 μg/mL while the minimum bactericidal concentration (MBC) was between 5 and 10 μg/mL toward S. suis. The use of a capsule-deficient mutant of S. suis indicated that the presence of this polysaccharidic structure has no marked impact on susceptibility to nisin. Following treatment of S. suis with nisin, transmission electron microscopy observations revealed lysis of bacteria resulting from breakdown of the cell membrane. A time-killing curve showed a rapid bactericidal activity of nisin. Lastly, synergistic effects of nisin were observed in combination with several antibiotics, including penicillin, amoxicillin, tetracycline, streptomycin and ceftiofur. This study brought clear evidence supporting the potential of nisin for the prevention and treatment of S. suis infections in pigs.
Maio, Elisa; Begeman, Lineke; Bisselink, Yvette; van Tulden, Peter; Wiersma, Lidewij; Hiemstra, Sjoukje; Ruuls, Robin; Gröne, Andrea; Roest, Hendrik-Ido-Jan; Willemsen, Peter; van der Giessen, Joke
The presence of Brucella (B.) spp. in harbour porpoises stranded between 2008 and 2011 along the Dutch coast was studied. A selection of 265 tissue samples from 112 animals was analysed using conventional and molecular methods. In total, 4.5% (5/112) of the animals corresponding with 2.3% (6/265) Brucella positive tissue samples were Brucella positive by culture and these were all confirmed by real-time polymerase chain reaction (real-time PCR) based on the insertion element 711 (IS711). In addition, two more Brucella-positive tissue samples from two animals collected in 2011 were identified using real-time PCR resulting in an overall Brucella prevalence of 6.3% (7/112 animals). Brucella spp. were obtained from lungs (n=3), pulmonary lymph node (n=3) and lungworms (n=2). Multi Locus Variable Number of Tandem Repeats (VNTR) Analysis (MLVA) typing based on the MLVA-16 showed that the Brucella isolates were B. ceti. Additional in silico Multi Locus Sequence typing (MLST) after whole genome sequencing of the 6 Brucella isolates confirmed B. ceti ST 23. According to the Brucella 2010 MLVA database, the isolated Brucella strains encountered were of five genotypes, in two distinct subclusters divided in two different time periods of harbour porpoises collection. This study is the first population based analyses for Brucella spp. infections in cetaceans stranded along the Dutch coast.
Eisenberg, Tobias; Riße, Karin; Schauerte, Nicole; Geiger, Christina; Blom, Jochen; Scholz, Holger C
A pleomorphic Gram-negative, motile coccobacillus was isolated from the gills of a wild-caught bluespotted ribbontail ray after its sudden death during quarantine. Strain 141012304 was observed to grow aerobically, to be clearly positive for cytochrome oxidase, catalase, urease and was initially identified as "Brucella melitensis" or "Ochrobactrum anthropi" by Matrix-assisted laser desorption/ionization-time of flight mass spectrometry and VITEK2-compact(®), respectively. Affiliation to the genus Brucella was confirmed by bcsp31 and IS711 PCR as well as by Brucella species-specific multiplex PCR, therein displaying a characteristic banding pattern recently described for Brucella strains obtained from amphibian hosts. Likewise, based on recA sequencing, strain 141012304 was found to form a separate lineage, within the so called 'atypical' Brucella, consisting of genetically more distantly related strains. The closest similarity was detected to brucellae, which have recently been isolated from edible bull frogs. Subsequent next generation genome sequencing and phylogenetic analysis confirmed that the ray strain represents a novel Brucella lineage within the atypical group of Brucella and in vicinity to Brucella inopinata and Brucella strain BO2, both isolated from human patients. This is the first report of a natural Brucella infection in a saltwater fish extending the host range of this medically important genus.
Dietz, Stefanie; Lassek, Christian; Mack, Sarah-Lena; Ritzmann, Mathias; Stadler, Julia; Becher, Dörte; Hoelzle, Katharina; Riedel, Katharina; Hoelzle, Ludwig E
Mycoplasma suis belongs to the hemotrophic mycoplasmas that are associated with acute and chronic anemia in a wide range of livestock and wild animals. The inability to culture M. suis in vitro has hindered its characterization at the molecular level. Since the publication of M. suis genome sequences in 2011 only one proteome study has been published. Aim of the presented study was to significantly extend the proteome coverage of M. suis strain KI_3806 during acute infection by applying three different protein extraction methods followed by 1D SDS-PAGE and LC-MS/MS. A total of 404 of 795 M. suis KI_3806 proteins (50.8%) were identified. Data analysis revealed the expression of 83.7% of the predicted ORFs with assigned functions but also highlights the expression of 179 of 523 (34.2%) hypothetical proteins with unknown functions. Computational analyses identified expressed membrane-associated hypothetical proteins that might be involved in adhesion or host-pathogen interaction. Furthermore, analyses of the expressed proteins indicated the existence of a hexose-6-phosphate-transporter and an ECF transporter. In conclusion, our proteome study provides a further step toward the elucidation of the unique life cycle of M. suis and the establishment of an in vitro culture. All MS data have been deposited in the ProteomeXchange with identifier PXD002294 (http://proteomecentral.proteomexchange.org/dataset/PXD002294).
Liu, Mingming; Jia, Lijun; Li, Jixu; Xue, Shujiang; Gao, Xu; Yu, Longzheng; Zhang, Shoufa
Mycoplasma suis belongs to the haemotrophic mycoplasmas, which colonise the red blood cells of a wide range of vertebrates. Adhesion to red blood cells is the crucial step in the unique lifecycle of M. suis. In addition to MSG1 protein, α-enolase is the second adhesion protein of M. suis, and may be involved in the adhesion of M. suis to porcine red blood cells (RBC). To simulate the environment of the RBC, we established the cDNA library of swine peripheral blood mononuclear cells (PBMC). The yeast two-hybrid (Y2H) system was adopted to screen α-enolase interactive proteins in the PBMC line. Alignment with the NCBI database revealed four interactive proteins: beta-actin, 60S ribosomal protein L11, clusterin precursor and endonuclease/reverse transcriptase. However, the M. suis α-enolase interactive proteins in the PBMC cDNA library obtained in the current study provide valuable information about the host cell interactions of the M. suis α-enolase protein.
Feng, Liping; Zhu, Jiawen; Chang, Haitao; Gao, Xiaoping; Gao, Cheng; Wei, Xiaofeng; Yuan, Fangyan; Bei, Weicheng
The main role of CodY, a global regulatory protein in most low G + C gram-positive bacteria, is in transcriptional repression. To study the functions of CodY in Streptococcus suis serotype 2 (S. suis 2), a mutant codY clone named ∆codY was constructed to explore the phenotypic variation between ∆codY and the wild-type strain. The result showed that the codY mutation significantly inhibited cell growth, adherence and invasion ability of S. suis 2 to HEp-2 cells. The codY mutation led to decreased binding of the pathogen to the host cells, easier clearance by RAW264.7 macrophages and decreased growth ability in fresh blood of Cavia porcellus. The codY mutation also attenuated the virulence of S. suis 2 in BALB/c mice. Morphological analysis revealed that the codY mutation decreased the thickness of the capsule of S. suis 2 and changed the surface structures analylized by SDS-PAGE. Finally, the codY mutation altered the expressions of many virulence related genes, including sialic acid synthesis genes, leading to a decreased sialic acid content in capsule. Overall, mutation of codY modulated bacterial virulence by affecting the growth and colonization of S. suis 2, and at least via regulating sialic acid synthesis and capsule thickness. PMID:26883762
Pérez-Sancho, Marta; Vela, Ana Isabel; García-Seco, Teresa; Gottschalk, Marcelo; Domínguez, Lucas; Fernández-Garayzábal, José Francisco
The accuracy of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) for identifying Streptococcus suis isolates obtained from pigs, wild animals, and humans was evaluated using a PCR-based identification assay as the gold standard. In addition, MALDI-TOF MS was compared with the commercial multi-tests Rapid ID 32 STREP system. From the 129 S. suis isolates included in the study and identified by the molecular method, only 31 isolates (24.03%) had score values ≥2.300 and 79 isolates (61.24%) gave score values between 2.299 and 2.000. After updating the currently available S. suis MALDI Biotyper database with the spectra of three additional clinical isolates of serotypes 2, 7, and 9, most isolates had statistically significant higher score values (mean score: 2.65) than those obtained using the original database (mean score: 2.182). Considering the results of the present study, we suggest using a less restrictive threshold score of ≥2.000 for reliable species identification of S. suis. According to this cut-off value, a total of 125 S. suis isolates (96.9%) were correctly identified using the updated database. These data indicate an excellent performance of MALDI-TOF MS for the identification of S. suis. PMID:26347858
Athey, Taryn B. T.; Teatero, Sarah; Takamatsu, Daisuke; Wasserscheid, Jessica; Dewar, Ken; Gottschalk, Marcelo; Fittipaldi, Nahuel
Strains of serotype 2 Streptococcus suis are responsible for swine and human infections. Different serotype 2 genetic backgrounds have been defined using multilocus sequence typing (MLST). However, little is known about the genetic diversity within each MLST sequence type (ST). Here, we used whole-genome sequencing to test the hypothesis that S. suis serotype 2 strains of the ST25 lineage are genetically heterogeneous. We evaluated 51 serotype 2 ST25 S. suis strains isolated from diseased pigs and humans in Canada, the United States of America, and Thailand. Whole-genome sequencing revealed numerous large-scale rearrangements in the ST25 genome, compared to the genomes of ST1 and ST28 S. suis strains, which result, among other changes, in disruption of a pilus island locus. We report that recombination and lateral gene transfer contribute to ST25 genetic diversity. Phylogenetic analysis identified two main and distinct Thai and North American clades grouping most strains investigated. These clades also possessed distinct patterns of antimicrobial resistance genes, which correlated with acquisition of different integrative and conjugative elements (ICEs). Some of these ICEs were found to be integrated at a recombination hot spot, previously identified as the site of integration of the 89K pathogenicity island in serotype 2 ST7 S. suis strains. Our results highlight the limitations of MLST for phylogenetic analysis of S. suis, and the importance of lateral gene transfer and recombination as drivers of diversity in this swine pathogen and zoonotic agent. PMID:26954687
Berthelot-Hérault, F; Cariolet, R; Labbé, A; Gottschalk, M; Cardinal, J Y; Kobisch, M
A standardized model of Streptococcus suis type 2 infection in specific-pathogen-free piglets, housed in high-security barns, was used to compare the virulence of 3 French field strains of S. suis serotype 2 isolated from tonsils of a healthy pig (strain 65) or from diseased pigs (meningitis, strain 166', or septicemia, strain 24). In one of the 2 trials, 7-week-old pigs, in 3 groups of 8, were inoculated intravenously with 2 x 10(8) colony-forming units of S. suis type 2. In each group, 1 uninfected animal was a sentinel. Eight animals were also used as negative control group. The experiment was repeated under similar conditions with strains 65 and 166'. Virulence differed markedly among these S. suis strains when clinical signs, zootechnical performances, lesions, and bacteriological data were analyzed. Strain 65 did not induce clinical signs in inoculated pigs. In contrast, pigs infected with the other 2 strains exhibited clinical signs and typical lesions of S. suis type 2 infections. Differences in virulence were also observed between the 2 virulent strains. Sentinel animals exhibited the same manifestations as those recorded in inoculated piglets. Results were similar in the second trial, indicating that under the present experimental conditions, results were reproducible. The standardized conditions described in this study could be a useful tool to further study about the S. suis infection. PMID:11480526
Zaccaria, Edoardo; Cao, Rui; Wells, Jerry M.; van Baarlen, Peter
Streptococcus suis is an encapsulated Gram-positive bacterium, and the leading cause of sepsis and meningitis in young pigs resulting in considerable economic losses in the porcine industry. It is also considered an emerging zoonotic agent. In the environment, both avirulent and virulent strains occur in pigs, and virulent strains appear to cause disease in both humans and pigs. There is a need for a convenient, reliable and standardized animal model to assess S. suis virulence. A zebrafish (Danio rerio) larvae infection model has several advantages, including transparency of larvae, low cost, ease of use and exemption from ethical legislation up to 6 days post fertilization, but has not been previously established as a model for S. suis. Microinjection of different porcine strains of S. suis in zebrafish larvae resulted in highly reproducible dose- and strain-dependent larval death, strongly correlating with presence of the S. suis capsule and to the original virulence of the strain in pigs. Additionally we compared the virulence of the two-component system mutant of ciaRH, which is attenuated for virulence in both mice and pigs in vivo. Infection of larvae with the ΔciaRH strain resulted in significantly higher survival rate compared to infection with the S10 wild-type strain. Our data demonstrate that zebrafish larvae are a rapid and reliable model to assess the virulence of clinical porcine S. suis isolates. PMID:26999052
Cui, Guimei; Wei, Pan; Zhao, Yuxi; Guan, Zhenhong; Yang, Li; Sun, Wanchun; Wang, Shuangxi; Peng, Qisheng
The calcium-dependent protease calpain2 is involved in macrophages apoptosis. Brucella infection-induced up-regulation of intracellular calcium level is an essential factor for the intracellular survival of Brucella within macrophages. Here, we hypothesize that calcium-dependent E3 ubiquitin ligase Nedd4 ubiquitinates calpain2 and inhibits Brucella infection-induced macrophage apoptosis via degradation of calpain2.Our results reveal that Brucella infection induces increases in Nedd4 activity in an intracellular calcium dependent manner. Furthermore, Brucella infection-induced degradation of calpain2 is mediated by Nedd4 ubiquitination of calpain2. Brucella infection-induced calpain2 degradation inhibited macrophages apoptosis. Treatment of Brucella infected macrophages with calcium chelator BAPTA or Nedd4 knock-down decreased Nedd4 activity, prevented calpain2 degradation, and resulted in macrophages apoptosis.
Banai, M; Adams, L G; Frey, M; Pugh, R; Ficht, T A
Brucella spp. L-forms have been proposed to be stationary phase organisms in the evolution of new variants and enduring entities in the host in complicated cases of brucellosis and during latent brucellosis. In vitro formation of Brucella L-forms has been achieved by treating the cells with sub-lethal doses of penicillin. Interestingly, Brucella spp. have classified during the evolution into two groups, penicillin susceptible or penicillin resistant, yet both types grow on 20 microg/ml of methicillin. Strains proven susceptible to penicillin grew in the presence of methicillin as L-forms as demonstrated by light and electron microscopy. In addition, the B. melitensis vaccine strain Rev.1, a penicillin susceptible organism, responded to sheep serum by development of L-form-like structures unlike wild type, strain 16M. The two strains grew normally in sheep macrophages. We propose, for the first time, a model that associates Brucella pathogenicity with the structure and activity of two of their penicillin binding proteins (PBPs). According to the model, PBP1 has evolved as the major cell wall synthesizing enzyme of the genus, capable of responding to host serum growth factor(s) necessary for Brucella survival in the host. This property is associated with high avidity to beta-lactam antibiotics. PBP2 complements the activity of PBP1. New beta-lactam antibiotics and improved vaccines might be developed based on this property.
Lachance, Claude; Segura, Mariela; Dominguez-Punaro, Maria C; Wojewodka, Gabriella; De Sanctis, Juan B; Radzioch, Danuta; Gottschalk, Marcelo
Streptococcus suis is an important swine pathogen and an emergent zoonotic pathogen. Excessive inflammation caused by S. suis is responsible for early high mortality in septic shock-like syndrome cases. Polyunsaturated fatty acids (PUFAs) may contribute to regulating inflammatory processes. This study shows that mouse infection by S. suis is accompanied by an increase of arachidonic acid, a proinflammatory omega-6 (ω-6) PUFA, and by a decrease of docosahexaenoic acid, an anti-inflammatory ω-3 PUFA. Macrophages infected with S. suis showed activation of mitogen-activated protein kinase pathways and cyclooxygenase-2 upregulation. Fenretinide, a synthetic vitamin A analog, reduced in vitro expression of inflammatory mediators. Pretreatment of mice with fenretinide significantly improved their survival by reducing systemic proinflammatory cytokines during the acute phase of an S. suis infection. These findings indicate a beneficial effect of fenretinide in diminishing the expression of inflammation and improving survival during an acute infection by a virulent S. suis strain.
Sciutto, Edda; Toledo, Andrea; Cruz, Carmen; Rosas, Gabriela; Meneses, Gabriela; Laplagne, Diego; Ainciart, Natalia; Cervantes, Jacquelynne; Fragoso, Gladis; Goldbaum, Fernando A
Lumazine synthase from Brucella spp. (BLS) was evaluated as a protein carrier to improve antigen delivery of KETc1, one of the peptides of the anti-cysticercosis vaccine. KETc1 becomes antigenic, preserved its immunogenicity and its protective capacity when expressed as a recombinant chimeric protein using Brucella spp. lumazine synthase. KETc1 and BLS-KETc1 were not MHC H-2(d), H-2(k) nor H-2(b) haplotype-restricted albeit KETc1 is preferentially presented in the H-2(b) haplotype. These findings support that BLS is a potent new delivery system for the improvement of subunit vaccines.
Guzmán-Verri, Caterina; González-Barrientos, Rocío; Hernández-Mora, Gabriela; Morales, Juan-Alberto; Baquero-Calvo, Elías; Chaves-Olarte, Esteban; Moreno, Edgardo
Since the first case of brucellosis detected in a dolphin aborted fetus, an increasing number of Brucella ceti isolates has been reported in members of the two suborders of cetaceans: Mysticeti and Odontoceti. Serological surveys have shown that cetacean brucellosis may be distributed worldwide in the oceans. Although all B. ceti isolates have been included within the same species, three different groups have been recognized according to their preferred host, bacteriological properties, and distinct genetic traits: B. ceti dolphin type, B. ceti porpoise type, and B. ceti human type. It seems that B. ceti porpoise type is more closely related to B. ceti human isolates and B. pinnipedialis group, while B. ceti dolphin type seems ancestral to them. Based on comparative phylogenetic analysis, it is feasible that the B. ceti ancestor radiated in a terrestrial artiodactyl host close to the Raoellidae family about 58 million years ago. The more likely mode of transmission of B. ceti seems to be through sexual intercourse, maternal feeding, aborted fetuses, placental tissues, vertical transmission from mother to the fetus or through fish or helminth reservoirs. The B. ceti dolphin and porpoise types seem to display variable virulence in land animal models and low infectivity for humans. However, brucellosis in some dolphins and porpoises has been demonstrated to be a severe chronic disease, displaying significant clinical and pathological signs related to abortions, male infertility, neurobrucellosis, cardiopathies, bone and skin lesions, strandings, and death. PMID:22919595
Randhawa, A S; Kelly, V P; Baker, E F
The prevalence of agglutinins to Coxiella burnetii and Brucella spp, particularly Brucella canis, was determined in 269 wild animals (14 species) in southern Texas. Serologic evidence of coxiellosis and brucellosis, including B canis infection, was shown for coyotes, raccoons, opossums, badgers, jackrabbits, and feral hogs. Using the microagglutination test, the seroprevalence of C burnetii, phases I and II (titer greater than or equal to 4) was 4.1 and 27.9%, respectively. For brucella agglutinins, prevalence rates were 7.1, 8.9, and 6.7%, as determined by the brucellosis card test, the rapid slide agglutination test, and the salt 2-mercaptoethanol tube agglutination (titer greater than or equal to 50) test, respectively.
Zheng, Chengkun; Xu, Jiali; Ren, Sujing; Li, Jinquan; Xia, Miaomiao; Chen, Huanchun; Bei, Weicheng
Toxin-antitoxin (TA) systems are widely prevalent in the genomes of bacteria and archaea. These modules have been identified in Escherichia coli and various other bacteria. However, their presence in the genome of Streptococcus suis, an important zoonotic pathogen, has received little attention. In this study, we describe the identification and characterization of a type II TA system, comprising the chromosomal yefM-yoeB locus of S. suis. The yefM-yoeB locus is present in the genome of most serotypes of S. suis. Overproduction of S. suis YoeB toxin inhibited the growth of E. coli, and the toxicity of S. suis YoeB could be alleviated by the antitoxin YefM from S. suis and Streptococcus pneumoniae, but not by E. coli YefM. More importantly, introduction of the S. suis yefM-yoeB system into E. coli could affect cell growth. In a murine infection model, deletion of the yefM-yoeB locus had no effect on the virulence of S. suis serotype 2. Collectively, our data suggested that the yefM-yoeB locus of S. suis is an active TA system without the involvement of virulence. PMID:26272287
Fernandez-Prada, Carmen M.; Nikolich, Mikeljon; Vemulapalli, Ramesh; Sriranganathan, Nammalwar; Boyle, Stephen M.; Schurig, Gerhardt G.; Hadfield, Ted L.; Hoover, David L.
Brucella spp. are gram-negative intracellular pathogens that survive and multiply within phagocytic cells of their hosts. Smooth organisms present O polysaccharides (OPS) on their surface. These OPS help the bacteria avoid the bactericidal action of serum. The wboA gene, coding for the enzyme glycosyltransferase, is essential for the synthesis of O chain in Brucella. In this study, the sensitivity to serum of smooth, virulent Brucella melitensis 16M and B. abortus 2308, rough wboA mutants VTRM1, RA1, and WRR51 derived from these two Brucella species, and the B. abortus vaccine strain RB51 was assayed using normal nonimmune human serum (NHS). The deposition of complement components and mannose-binding lectin (MBL) on the bacterial surface was detected by flow cytometry. Rough B. abortus mutants were more sensitive to the bactericidal action of NHS than were rough B. melitensis mutants. Complement components were deposited on smooth strains at a slower rate compared to rough strains. Deposition of iC3b and C5b-9 and bacterial killing occurred when bacteria were treated with C1q-depleted, but not with C2-depleted serum or NHS in the presence of Mg-EGTA. These results indicate that (i) OPS-deficient strains derived from B. melitensis 16M are more resistant to the bactericidal action of NHS than OPS-deficient strains derived from B. abortus 2308, (ii) both the classical and the MBL-mediated pathways are involved in complement deposition and complement-mediated killing of Brucella, and (iii) the alternative pathway is not activated by smooth or rough brucellae. PMID:11401980
Aydin, Emsal; Karadag, Mert Ali; Cecen, Kursat; Cigsar, Gulsen; Aydin, Sergulen; Demir, Aslan; Bagcioglu, Murat; Tekdogan, Umit Yener
We evaluated the association between the mean platelet volume (MPV) and monocyte/lymphocyte ratio (MLR) with brucella-caused epididymo-orchitis to determine if they could be used to differentiate between brucella and non-brucella epididymo-orchitis. The charts of 88 patients with non-brucella and 14 patients with brucella epididymo-orchitis were retrospectively reviewed. Brucellosis was diagnosed by isolating Brucella spp from a blood culture or from a serum agglutination titer ≥ 1:160 along with accompanying clinical findings. The patients with brucella epididymo-orchitis were significantly more likely to have a lower MPV and a higher MLR than those with non-brucella epididymo-orchitis. Using a MPV cut-off level of less than 9.25 fl to differentiate brucella from non-brucella epididymo-orchitis gives a sensitivity of 78.6%, a specifity of 78.4%, a positive predictive value of 36.7% and a negative predictive value of 95.8%. Using a MLR cut-off level of greater than 0.265 to differentiate brucella from non-brucella epididymo-orchitis gives a sensitivity of 71.4%, a specifity of 65.9%, a positive predictive value of 25% and a negative predictive value of 93.5.%. MPV and MLR values may assist in differentiating between brucella and non-brucella epididymo-orchitis.
Nomoto, R; Maruyama, F; Ishida, S; Tohya, M; Sekizaki, T; Osawa, Ro
In order to clarify the taxonomic position of serotypes 20, 22 and 26 of Streptococcus suis, biochemical and molecular genetic studies were performed on isolates (SUT-7, SUT-286(T), SUT-319, SUT-328 and SUT-380) reacted with specific antisera of serotypes 20, 22 or 26 from the saliva of healthy pigs as well as reference strains of serotypes 20, 22 and 26. Comparative recN gene sequencing showed high genetic relatedness among our isolates, but marked differences from the type strain S. suis NCTC 10234(T), i.e. 74.8-75.7 % sequence similarity. The genomic relatedness between the isolates and other strains of species of the genus Streptococcus, including S. suis, was calculated using the average nucleotide identity values of whole genome sequences, which indicated that serotypes 20, 22 and 26 should be removed taxonomically from S. suis and treated as a novel genomic species. Comparative sequence analysis revealed 99.0-100 % sequence similarities for the 16S rRNA genes between the reference strains of serotypes 20, 22 and 26, and our isolates. Isolate STU-286(T) had relatively high 16S rRNA gene sequence similarity with S. suis NCTC 10234(T) (98.8 %). SUT-286(T) could be distinguished from S. suis and other closely related species of the genus Streptococcus using biochemical tests. Due to its phylogenetic and phenotypic similarities to S. suis we propose naming the novel species Streptococcus parasuis sp. nov., with SUT-286(T) ( = JCM 30273(T) = DSM 29126(T)) as the type strain.
Background Streptococcus suis is a zoonotic pathogen that causes infections in young piglets. S. suis is a heterogeneous species. Thirty-three different capsular serotypes have been described, that differ in virulence between as well as within serotypes. Results In this study, the correlation between gene content, serotype, phenotype and virulence among 55 S. suis strains was studied using Comparative Genome Hybridization (CGH). Clustering of CGH data divided S. suis isolates into two clusters, A and B. Cluster A isolates could be discriminated from cluster B isolates based on the protein expression of extracellular factor (EF). Cluster A contained serotype 1 and 2 isolates that were correlated with virulence. Cluster B mainly contained serotype 7 and 9 isolates. Genetic similarity was observed between serotype 7 and serotype 2 isolates that do not express muramidase released protein (MRP) and EF (MRP-EF-), suggesting these isolates originated from a common founder. Profiles of 25 putative virulence-associated genes of S. suis were determined among the 55 isolates. Presence of all 25 genes was shown for cluster A isolates, whereas cluster B isolates lacked one or more putative virulence genes. Divergence of S. suis isolates was further studied based on the presence of 39 regions of difference. Conservation of genes was evaluated by the definition of a core genome that contained 78% of all ORFs in P1/7. Conclusions In conclusion, we show that CGH is a valuable method to study distribution of genes or gene clusters among isolates in detail, yielding information on genetic similarity, and virulence traits of S. suis isolates. PMID:21736719
Vela, Ana I; Perez Sancho, Marta; Domínguez, Lucas; Busse, Hans-Jürgen; Fernández-Garayzábal, Jose F
Biochemical and molecular genetic studies were performed on three novel Gram-stain-negative, catalase- and oxidase-positive, bacilli-shaped organisms isolated from the tonsils of two pigs and one wild boar. The micro-organism was identified as a species of the genus Pelistega based on its cellular morphological and biochemical tests. The closest phylogenetic relative of the novel bacilli was Pelistega indica HM-7T (98.2 % 16S rRNA gene sequence similarity to the type strain). groEL and gyrB sequence analysis showed interspecies divergence from the closest 16S rRNA gene phylogenetic relative, P. indica of 87.0.% and 69 %, respectively. The polyamine pattern contains predominantly putrescine and 2-hydroxyputrescine. The major quinone is ubiquinone Q-8 and in the polar lipid profile, phosphatidylethanolamine, phosphatidylglycerol, an unidentified aminolipid and an unidentified lipid are predominant. The novel bacterial isolate can be distinguished from P. indica by several biochemical characteristics, such as the production of l-pyrrolydonil arylamidase but not gamma-glutamyl-transferase, and the utilization of different carbon sources. Based on both phenotypic and phylogenetic findings, the novel bacterium is classified as representing a novel species of the genus Pelistega, for which the name Pelistega suis sp. nov. is proposed. The type strain is 3340-03T ( = CECT 8400T = CCUG 64465T).
Bukata, Lucas; Altabe, Silvia; de Mendoza, Diego; Ugalde, Rodolfo A.; Comerci, Diego J.
The Brucella cell envelope contains the zwitterionic phospholipids phosphatidylcholine (PC) and phosphatidylethanolamine (PE). Synthesis of PC occurs exclusively via the PC synthase pathway, implying that the pathogen depends on the choline synthesized by the host cell to form PC. Notably, PC is necessary to sustain a chronic infection process, which suggests that the membrane lipid content is relevant for Brucella virulence. In this study we investigated the first step of PE biosynthesis in B. abortus, which is catalyzed by phosphatidylserine synthase (PssA). Disruption of pssA abrogated the synthesis of PE without affecting the growth in rich complex medium. In minimal medium, however, the mutant required choline supplementation for growth, suggesting that at least PE or PC is necessary for Brucella viability. The absence of PE altered cell surface properties, but most importantly, it impaired several virulence traits of B. abortus, such as intracellular survival in both macrophages and HeLa cells, the maturation of the replicative Brucella-containing vacuole, and mouse colonization. These results suggest that membrane phospholipid composition is critical for the interaction of B. abortus with the host cell. PMID:18931122
Comerci, Diego J.; Altabe, Silvia; de Mendoza, Diego; Ugalde, Rodolfo A.
The Brucella cell envelope is characterized by the presence of phosphatidylcholine (PC), a common phospholipid in eukaryotes that is rare in prokaryotes. Studies on the composition of Brucella abortus 2308 phospholipids revealed that the synthesis of PC depends on the presence of choline in the culture medium, suggesting that the methylation biosynthetic pathway is not functional. Phospholipid composition of pmtA and pcs mutants indicated that in Brucella, PC synthesis occurs exclusively via the phosphatidylcholine synthase pathway. Transformation of Escherichia coli with an expression vector containing the B. abortus pcs homologue was sufficient for PC synthesis upon induction with IPTG (isopropyl-β-d-thiogalactopyranoside), while no PC formation was detected when bacteria were transformed with a vector containing pmtA. These findings imply that Brucella depends on choline provided by the host cell to form PC. We could not detect any obvious associated phenotype in the PC-deficient strain under vegetative or intracellular growth conditions in macrophages. However, the pcs mutant strain displays a reproducible virulence defect in mice, which suggests that PC is necessary to sustain a chronic infection process. PMID:16484204
L'vov, V L; Pluzhnikova, G N; Lapina, E B; Shashkov, A S; Askerova, S A
Cyclic (1----2)-beta-D-glucan was isolated from killed cells of pathogenic Brucella melitensis 16M. Its structure was deduced mainly from the acid hydrolysis, methylation analysis and 13C-NMR spectroscopy data. The cycloglucan and demicellated lipopolysaccharide of B. melitensis 16M form a stable complex identical, by immunodiffusion test, to the earlier described polysaccharide B antigen.
... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Detection of Brucella contamination. 113.32 Section 113.32 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE... antibiotics, diluent and stabilizer, shall be inoculated onto each of three tryptose agar plates and...
To characterize the optimal aerosol dosage of Brucella abortus strain 2308 (S2308) and B. melitensis (S16M) in a laboratory animal model of brucellosis, dosages of 10**3 to 10**10 CFU were nebulized to mice. Although tissue weights were minimally influenced, total colony-forming units (CFU) per tis...
... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Detection of Brucella contamination. 113.32 Section 113.32 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE... tissue used as the source of cells or 1 ml of the extract of the tissue prior to the addition...
... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Detection of Brucella contamination. 113.32 Section 113.32 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE... tissue used as the source of cells or 1 ml of the extract of the tissue prior to the addition...
... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Detection of Brucella contamination. 113.32 Section 113.32 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE... tissue used as the source of cells or 1 ml of the extract of the tissue prior to the addition...
... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Detection of Brucella contamination. 113.32 Section 113.32 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE... tissue used as the source of cells or 1 ml of the extract of the tissue prior to the addition...
Vaillancourt, Katy; LeBel, Geneviève; Frenette, Michel; Gottschalk, Marcelo; Grenier, Daniel
While Streptococcus suis serotype 2 is known to cause severe infections in pigs, it can also be isolated from the tonsils of healthy animals that do not develop infections. We hypothesized that S. suis strains in healthy carrier pigs may have the ability to produce bacteriocins, which may contribute to preventing infections by pathogenic S. suis strains. Two of ten S. suis serotype 2 strains isolated from healthy carrier pigs exhibited antibacterial activity against pathogenic S. suis isolates. The bacteriocin produced by S. suis 3908 was purified to homogeneity using a three-step procedure: ammonium sulfate precipitation, cationic exchange HPLC, and reversed-phase HPLC. The bacteriocin, called suicin 3908, had a low molecular mass; was resistant to heat, pH, and protease treatments; and possessed membrane permeabilization activity. Additive effects were obtained when suicin 3908 was used in combination with penicillin G or amoxicillin. The amino acid sequence of suicin 3908 suggested that it is lantibiotic-related and made it possible to identify a bacteriocin locus in the genome of S. suis D12. The putative gene cluster involved in suicin production by S. suis 3908 was amplified by PCR, and the sequence analysis revealed the presence of nine open reading frames (ORFs), including the structural gene and those required for the modification of amino acids, export, regulation, and immunity. Suicin 3908, which is encoded by the suiA gene, exhibited approximately 50% identity with bovicin HJ50 (Streptococcus bovis), thermophilin 1277 (Streptococcus thermophilus), and macedovicin (Streptococcus macedonicus). Given that S. suis 3908 cannot cause infections in animal models, that it is susceptible to conventional antibiotics, and that it produces a bacteriocin with antibacterial activity against all pathogenic S. suis strains tested, it could potentially be used to prevent infections and to reduce antibiotic use by the swine industry.
Mohamed Zahidi, Jama'ayah; Bee Yong, Tay; Hashim, Rohaidah; Mohd Noor, Azura; Hamzah, Siti Hawa; Ahmad, Norazah
Molecular approaches have been investigated to overcome difficulties in identification and differentiation of Brucella spp. using conventional phenotypic methods. In this study, high-resolution melt (HRM) analysis was used for rapid identification and differentiation of members of Brucella genus. A total of 41 Brucella spp. isolates from human brucellosis were subjected to HRM analysis using 4 sets of primers, which identified 40 isolates as Brucella melitensis and 1 as Brucella canis. The technique utilized low DNA concentration and was highly reproducible. The assay is shown to be a useful diagnostic tool, which can rapidly differentiate Brucella up to species level.
Marois, Corinne; Le Devendec, Laëtitia; Gottschalk, Marcelo; Kobisch, Marylène
Streptococcus suis is an important pathogen of swine, causing meningitis, arthritis, polyserositis, septicemia, and sudden death in weaning piglets as well as fattening pigs. Recently, 3 molecular tests have been developed in our laboratory: a multiplex polymerase chain reaction (m-PCR) assay for the detection of S. suis species and serotypes 2 and 1/2, and 2 molecular typing methods, pulsed-field gel electrophoresis and an approach based on PCR amplification of a fragment of rRNA genes, including a part of the 16S and 23S genes and the 16S–23S rDNA intergenic spacer region (ISR), followed by restriction fragment length polymorphism (RFLP) analysis (ISR-RFLP). In the present study, we used these tests to analyze tonsil samples from clinically healthy pigs and to identify individual isolates of S. suis during epidemiologic investigations of 8 related herds with a history of septicemia caused by S. suis serotype 2. Capsular typing showed that 58% of the strains were nontypable. Of the 17 serotypes present, serotype 22 was the most prevalent. In the 7 farms without clinical signs on the day of sampling, we detected S. suis serotype 2 or 1/2, or both, in less than 5% of the pigs by m-PCR or by bacteriologic culture. In the 8th farm, on which 2 pigs had clinical signs of septicemia on the day of sampling, we detected S. suis serotype 2 or 1/2, or both, by m-PCR in the tonsils of 40% of fattening pigs (21 wk old) that lacked symptoms. Molecular typing of the serotype 2 strains showed a common origin of contamination in these herds, given that 1 pattern (C1) was detected in the isolates from 6 of the 8 herds. However, up to 4 patterns were associated with septicemia and sudden death. Several patterns of S. suis serotype 2 can be responsible for disease in the same herd. These molecular tools may be useful for confident studies of the transmission of S. suis, thereby contributing to the control of S. suis infection. PMID:17193877
Koczula, Anna; Jarek, Michael; Visscher, Christian; Valentin-Weigand, Peter; Goethe, Ralph; Willenborg, Jörg
Streptococcus suis is a zoonotic pathogen that can cause severe pathologies such as septicemia and meningitis in its natural porcine host as well as in humans. Establishment of disease requires not only virulence of the infecting strain but also an appropriate metabolic activity of the pathogen in its host environment. However, it is yet largely unknown how the streptococcal metabolism adapts to the different host niches encountered during infection. Our previous isotopologue profiling studies on S. suis grown in porcine blood and cerebrospinal fluid (CSF) revealed conserved activities of central carbon metabolism in both body fluids. On the other hand, they suggested differences in the de novo amino acid biosynthesis. This prompted us to further dissect S. suis adaptation to porcine blood and CSF by RNA deep sequencing (RNA-seq). In blood, the majority of differentially expressed genes were associated with transport of alternative carbohydrate sources and the carbohydrate metabolism (pentose phosphate pathway, glycogen metabolism). In CSF, predominantly genes involved in the biosynthesis of branched-chain and aromatic amino acids were differentially expressed. Especially, isoleucine biosynthesis seems to be of major importance for S. suis in CSF because several related biosynthetic genes were more highly expressed. In conclusion, our data revealed niche-specific metabolic gene activity which emphasizes a selective adaptation of S. suis to host environments. PMID:28212285
Käser, Tobias; Cnudde, Thomas; Hamonic, Glenn; Rieder, Meghanne; Pasternak, J Alex; Lai, Ken; Tikoo, Suresh K; Wilson, Heather L; Meurens, François
Human ocular Chlamydia trachomatis infections can lead to trachoma, the major cause of infectious blindness worldwide. Trachoma control strategies are very helpful but logistically challenging, and a trachoma vaccine is needed but not available. Pigs are a valuable large animal model for various immunological questions and could facilitate the study of human ocular chlamydial infections. In addition, a recent study identified the zoonotic potential of Chlamydia suis, the natural pathogen of pigs. In terms of the One Health Initiative, understanding the host-pathogen-interactions and finding a vaccine for porcine chlamydia infections would also benefit human health. Thus, we infected the porcine retinal cell line VIDO R1 with C. suis and analyzed the chlamydial life cycle and the innate immune response of the infected cells. Our results indicate that C. suis completes its life cycle in VIDO R1 cells within 48 h, comparable to C. trachomatis in humans. C. suis infection of VIDO R1 cells led to increased levels of various innate immune mediators like pathogen recognition receptors, cytokines and chemokines including IL6, TNFα, and MMP9, also most relevant in human C. trachomatis infections. These results illustrate the first steps in the host-pathogen-interactions of ocular C. suis infections in pigs and show their similarity to C. trachomatis infections in humans, justifying further testing of pigs as an animal model for human trachoma.
Matsubayashi, Makoto; Takayama, Hideko; Kusumoto, Masahiro; Murata, Misato; Uchiyama, Yuka; Kaji, Masaya; Sasai, Kazumi; Yamaguchi, Ryosaku; Shibahara, Tomoyuki
Cystoisospora suis is a pathogen that causes diarrhea in pigs and can lead to serious disease. Species identification, especially by histopathological examination, is often difficult because of morphologically similar parasites such as Eimeria species. In this study, we used histopathological, bacteriological, virological, and parasitological methods to identify the cause of the disease in two piglets with severe diarrhea. Villous atrophy, diffuse necrosis, and flattening of mucosal epithelial cells were found in the ilea of examined piglets, and coccidian parasites were found in the cytoplasm of the epithelial cells. In some merozoites in the meronts, the presence of two nuclei indicated type 1 merozoites, characteristic of C. suis. According to Cystoisospora-specific PCR targeting the rRNA internal transcribed spacer 1 (ITS1) gene, the sequences of the products were 98.5% similar to those of C. suis. Escherichia coli (O149 serogroup) exhibiting a virulence factor profile (LT, STb, and EAST1 as toxins and F4 as a colonization factor) was detected in one piglet. No other bacteria or significant enteric viruses were found. Co-infection with C. suis and E. coli could imply aggravation of the disease, although further study is needed to assess the pathogenicity of this interaction. This study is the first to clarify by molecular analysis the sequences of C. suis detected in piglets in Japan.
Wan, Tien-Chun; Cheng, Fu-Yuan; Liu, Yu-Tse; Lin, Liang-Chuan; Sakata, Ryoichi
The purpose of the study was to investigate bioactive compounds of in vitro cultured Calculus Suis and natural Calculus Bovis obtained as valuable by-products from animals used for meat production. The results showed that the components of natural Calculus Bovis were rich in bilirubin and biliverdin and had higher content of essential amino acids. The major amino acids of in vitro cultured Calculus Suis were identified as glycine, alanine, glutamic acid and aspartic acid, and those for natural Calculus Bovis were found to be glutamic acid, aspartic acid, proline, and arginine. The methionine and cysteine contents of precursors for glutathione in natural Calculus Bovis were significantly higher than those of in vitro cultured Calculus Suis. The mineral contents of zinc, iron and manganese of natural Calculus Bovis were significantly higher than those of in vitro cultured Calculus Suis. The major bile acids in both products were cholic acid and dehydrocholic acid, respectively. The chenodeoxycholic and ursodeoxycholic acid content of in vitro cultured Calculus Suis was significantly higher than that of natural Calculus Bovis.
Wang, Kaicheng; Fan, Weixing; Wisselink, Henk; Lu, Chengping
Streptococcus suis serotype 16 can infect pigs and humans. We describe the identification and the characterization of the capsular polysaccharides synthesis locus of S. suis serotype 16. Using PCR primers flanking the capsular polysaccharides synthesis locus, a 30,101-bp fragment was amplified. Twenty-nine open reading frames related to transcriptional regulation, glycosyl transfer, oligosaccharide repeat unit polymerization, polysaccharide transport, sialic acid synthesis and modification were identified. The data suggests that the serotype 16 capsule is synthesized by a Wzy-dependent pathway. So far, no rapid and sensitive diagnostic method is available for detection of serotype 16 isolates. A serotype specific PCR test for the rapid and sensitive detection of S. suis serotype 16 was developed. Cross hybridization experiments of individual cps genes with chromosomal DNAs of 33 serotypes showed that the cps16G and cps16K genes hybridized with serotype 16 only. Primers based on cps16G were used to develop a serotype 16 specific PCR. The PCR assay was successfully used to identify S. suis serotype 16 in the 99 Chinese S. suis clinical isolates and 8 European isolates.
Li, Wei; Ye, Changyun; Jing, Huaiqi; Cui, Zhigang; Bai, Xuemei; Jin, Dong; Zheng, Han; Zhao, Ailan; Xu, Yanmei; Gottschalk, Marcelo; Xu, Jianguo
Two outbreaks of Streptococcus suis ST7 occurred in humans in 1998 and 2005 in China. PFGE of chromosome restriction fragments found all ST7 isolates to be indistinguishable. Due to the genetic homogeneity of ST7 isolates, development of a rapid sub-typing method with high discriminatory power for ST7 isolates is required. In this study, a novel method, MLVA, was developed to type S. suis serotype 2 strains. Further, this method was used to analyze outbreak-associated ST7 strains in China. A total of 144 ST7 S. suis isolates were sub-typed into 34 MLVA types. Among these, eight isolates from the 1998 outbreak were sub-typed into five MLVA types, of which four MLVA types were also detected in Sichuan in 2005. These data indicate that the pathogens responsible for the two outbreaks had the same origin. In addition, some observations also provided molecular evidence for the transmission route, possibly indicating that the MLVA method has usefulness in epidemiology. The developed MLVA scheme for S. suis has greater discriminative power than PFGE. The method described here may be useful for identifying the source of S. suis infection and monitoring its spread.
Kerdsin, Anusak; Oishi, Kazunori; Sripakdee, Saowalak; Boonkerd, Nitsara; Polwichai, Pitimol; Nakamura, Shota; Uchida, Ryuichi; Sawanpanyalert, Pathom; Dejsirilert, Surang
Most cases of Streptococcus suis infection in humans are caused by serotype 2 strains, and only a few cases caused by other serotypes have been reported. Among 177 human isolates of S. suis in Thailand, 12 (6.8 %) were identified as being of serotype 14, and an occurrence of sporadic S. suis serotype 14 infection was noted during 2006-2008, particularly in northern Thailand. Clinical presentations of the 12 patients (median age 62.9 years) included meningitis (58.3 %), septic arthritis (25 %) and sepsis (16.7 %). These clinical features were similar to those previously reported for S. suis infections, except that there were no fatal cases. All of the 12 serotype 14 strains belonged to the multilocus sequence types (ST) 105 (n=11) and the novel ST127 (n=1). Molecular typing by PFGE revealed four different pulsotypes, including an identical pattern for nine ST105 strains and three closely related patterns for two ST105 strains and one ST127 strain. Our PFGE data suggested clonal dissemination of ST105 strains in Thailand. Because serotype 14 is becoming a more common cause of S. suis infections in humans, diagnostic tests for serotype 14 should be performed in South-East Asian countries.
Bai, Jingwen; Yang, Yanbei; Wang, Shuai; Gao, Lingfei; Chen, Jianqing; Ren, Yongzhi; Ding, Wenya; Muhammad, Ishfaq; Li, Yanhua
Streptococcus suis (S. suis) is a zoonotic pathogen that causes severe disease symptoms in pigs and humans. Syringa oblata Lindl. distributed in the middle latitudes of Eurasia and North America were proved as the most development potential of Chinese Medicine. In this study, biofilm formation by S. suis decreased after growth with 1/2 MIC, 1/4 MIC, or 1/8 MIC of Syringa oblata Lindl. aqueous extract and rutin. Scanning electron microscopy analysis revealed the potential effect of Syringa oblata Lindl. aqueous extract and rutin against biofilm formation by S. suis. Using iTRAQ technology, comparative proteomic analyses was performed at two conditions: 1/2 MIC of Syringa oblata Lindl. aqueous extract treated and non-treated cells. The results revealed the existence of 28 proteins of varying amounts. We found that the majority of the proteins were related to cell growth and metabolism. We also found that Syringa oblata Lindl. Aqueous extract affected the synthesis enzymes. In summary, Syringa oblata Lindl. aqueous extract might be used to inhibit the biofilm formation effectively by S. suis, and the active ingredients of the Syringa oblate Lindl. aqueous extract is rutin. The content of rutin is 9.9 ± 0.089 mg/g dry weight. PMID:28194111
Roy, David; Grenier, Daniel; Segura, Mariela; Mathieu-Denoncourt, Annabelle; Gottschalk, Marcelo
Streptococcus suis is an important bacterial swine pathogen and a zoonotic agent. Recently, two surface proteins of S. suis, Fhb and Fhbp, have been described for their capacity to bind factor H-a soluble complement regulatory protein that protects host cells from complement-mediated damages. Results obtained in this study showed an important role of host factor H in the adhesion of S. suis to epithelial and endothelial cells. Both Fhb and Fhbp play, to a certain extent, a role in such increased factor H-dependent adhesion. The capsular polysaccharide (CPS) of S. suis, independently of the presence of its sialic acid moiety, was also shown to be involved in the recruitment of factor H. However, a triple mutant lacking Fhb, Fhbp and CPS was still able to recruit factor H resulting in the degradation of C3b in the presence of factor I. In the presence of complement factors, the double mutant lacking Fhb and Fhbp was similarly phagocytosed by human macrophages and killed by pig blood when compared to the wild-type strain. In conclusion, this study suggests that recruitment of factor H to the S. suis cell surface is multifactorial and redundant.
Roy, David; Grenier, Daniel; Segura, Mariela; Mathieu-Denoncourt, Annabelle; Gottschalk, Marcelo
Streptococcus suis is an important bacterial swine pathogen and a zoonotic agent. Recently, two surface proteins of S. suis, Fhb and Fhbp, have been described for their capacity to bind factor H—a soluble complement regulatory protein that protects host cells from complement-mediated damages. Results obtained in this study showed an important role of host factor H in the adhesion of S. suis to epithelial and endothelial cells. Both Fhb and Fhbp play, to a certain extent, a role in such increased factor H-dependent adhesion. The capsular polysaccharide (CPS) of S. suis, independently of the presence of its sialic acid moiety, was also shown to be involved in the recruitment of factor H. However, a triple mutant lacking Fhb, Fhbp and CPS was still able to recruit factor H resulting in the degradation of C3b in the presence of factor I. In the presence of complement factors, the double mutant lacking Fhb and Fhbp was similarly phagocytosed by human macrophages and killed by pig blood when compared to the wild-type strain. In conclusion, this study suggests that recruitment of factor H to the S. suis cell surface is multifactorial and redundant. PMID:27399785
Karsen, Hasan; Karahocagil, Mustafa Kasim; Irmak, Hasan; Demiröz, Ali Pekcan
Turkey is located at an endemic area for brusellosis and tuberculosis which are both important public health problems. Meningitis caused by Brucella and Mycobacterium spp. may be confused since the clinical and laboratory findings are similar. In this report, a meningitis case with Brucella and tuberculosis co-infection has been presented. A 19-years-old woman was admitted to our clinic with severe headache, fever, vomiting, meningeal irritation symptoms, confusion and diplopia. The patient was initially diagnosed as Brucella meningitis based on her history (stockbreeding, consuming raw milk products, clinical symptoms concordant to brucellosis lasting for 4-5 months), physical examination and laboratory findings of cerebrospinal fluid (CSF). Standard tube agglutination test for brucellosis was positive at 1/80 titer in CSF and at 1/640 titer in serum, whereas no growth of Brucella spp. was detected in CSF and blood cultures. Antibiotic therapy with ceftriaxone, rifampicin and doxycyclin was started, however, there was no clinical improvement and agitation and confusion of the patient continued by the end of second day of treatment. Repeated CSF examination yielded acid-fast bacteria. The patient was then diagnosed as meningitis with double etiology and the therapy was changed to ceftriaxone, streptomycin, morphozinamide, rifampicin and isoniazid for thirty days. Tuberculosis meningitis was confirmed with the growth of Mycobacterium tuberculosis on the 14th day of cultivation (BACTEC, Becton Dickinson, USA) of the CSF sample. On the 30th day of treatment she was discharged on anti-tuberculous treatment with isoniazid and rifampicin for 12 months. The follow-up of the patient on the first and third months of treatment revealed clinical and laboratory improvement. Since this was a rare case of Brucella and tuberculosis co-infection, this report emphasizes that such co-infections should be kept in mind especially in the endemic areas for tuberculosis and brucellosis.
Tabynov, Kaissar; Ryskeldinova, Sholpan; Sansyzbay, Abylai
Brucella melitensis can be transmitted and cause disease in cattle herds as a result of inadequate management of mixed livestock farms. Ideally, vaccines against Brucella abortus for cattle should also provide cross-protection against B. melitensis. Previously we created a novel influenza viral vector B. abortus (Flu-BA) vaccine expressing the Brucella ribosomal proteins L7/L12 or Omp16. This study demonstrated Flu-BA vaccine with adjuvant Montanide Gel01 provided 100% protection against abortion in vaccinated pregnant heifers and good cross-protection of the heifers and their calves or fetuses (90-100%) after challenge with B. melitensis 16M; the level of protection provided by Flu-BA was comparable to the commercial vaccine B. abortus S19. In terms of the index of infection and colonization of Brucella in tissues, both vaccines demonstrated significant (P=0.02 to P<0.0001) protection against B. melitensis 16M infection compared to the negative control group (PBS+Montanide Gel01). Thus, we conclude the Flu-BA vaccine provides cross-protection against B. melitensis infection in pregnant heifers.
Adone, Rosanna; Francia, Massimiliano; Pistoia, Claudia; Petrucci, Paola; Pesciaroli, Michele; Pasquali, Paolo
It has been demonstrated that antibodies specific for O-PS antigen of Brucella smooth strains are involved in the protective immunity of brucellosis. Since the rough strain Brucella melitensis B115 was able to protect mice against wild Brucella strains brucellosis despite the lack of anti-OPS antibodies, in this study we evaluated the biological significance of antibodies induced by this strain, directed to antigens other than O-PS, passively tranferred to untreated mice prior to infection with Brucella abortus 2308 and B. melitensis 16M virulent strains. The protective ability of specific antisera collected from mice vaccinated with B. melitensis B115, B. abortus RB51 and B. abortus S19 strains was compared. The results indicated that antibodies induced by B115 were able to confer a satisfactory protection, especially against B. abortus 2308, similar to that conferred by the antiserum S19, while the RB51 antiserum was ineffective. These findings suggest that antibodies induced by B115 could act as opsonins as well as antibodies anti-O-PS, thus triggering more efficient internalization and degradation of bacteria within phagocytes. This is the first study assessing the efficacy of antibodies directed to antigens other than O-PS in the course of brucellosis infection.
De Puysseleyr, Kristien; De Puysseleyr, Leentje; Geldhof, Julie; Cox, Eric; Vanrompay, Daisy
Pigs are the natural host for Chlamydia suis, a pathogen which is phylogenetically highly related to the human pathogen C. trachomatis. Chlamydia suis infections are generally treated with tetracyclines. In 1998, tetracyline resistant C. suis strains emerged on U.S. pig farms and they are currently present in the Belgian, Cypriote, German, Israeli, Italian and Swiss pig industry. Infections with tetracycline resistant C. suis strains are mainly associated with severe reproductive failure leading to marked economical loss. We developed a sensitive and specific TaqMan probe-based C. suis real-time PCR for examining clinical samples of both pigs and humans. The analytical sensitivity of the real-time PCR is 10 rDNA copies/reaction without cross-amplifying DNA of other Chlamydia species. The PCR was successfully validated using conjunctival, pharyngeal and stool samples of slaughterhouse employees, as well as porcine samples from two farms with evidence of reproductive failure and one farm without clinical disease. Chlamydia suis was only detected in diseased pigs and in the eyes of humans. Positive humans had no clinical complaints. PCR results were confirmed by culture in McCoy cells. In addition, Chlamydia suis isolates were also examined by the tet(C) PCR, designed for demonstrating the tetracycline resistance gene tet(C). The tet(C) gene was only present in porcine C. suis isolates.
Background The Gram-positive bacterium Streptococcus suis serotype 2 is an important swine pathogen and emerging zoonotic agent. Multilocus sequence typing allowed dividing S. suis serotype 2 into sequence types (STs). The three major STs of S. suis serotype 2 from North America are 1 (most virulent), 25 (intermediate virulence) and 28 (less virulent). Although the presence of DNase activity in S. suis has been previously reported, little data is available. The aim of this study was to investigate DNase activity in S. suis according to STs, to characterize the activity and gene, and to provide evidence for a potential role in virulence. Results We showed that ST1 and ST28 strains exhibited DNase activity that was absent in ST25 strains. The lack of activity in ST25 isolates was associated with a 14-bp deletion resulting in a shifted reading frame and a premature stop codon. The DNase of S. suis P1/7 (ST1) was cell-associated and active on linear DNA. A DNase-deficient mutant of S. suis P1/7 was found to be less virulent in an amoeba model. Stimulation of macrophages with the DNase mutant showed a decreased secretion of pro-inflammatory cytokines and matrix metalloproteinase-9 compared to the parental strain. Conclusions This study further expands our knowledge of S. suis DNase and its potential role in virulence. PMID:24996230
Haas, Bruno; Grenier, Daniel
Streptococcus suis is an important swine pathogen and emerging zoonotic agent worldwide causing meningitis, endocarditis, arthritis and septicemia. Among the 29 serotypes identified to date, serotype 2 is mostly isolated from diseased pigs. Although several virulence mechanisms have been characterized in S. suis, the pathogenesis of S. suis infections remains only partially understood. This study focuses on the response of S. suis P1/7 to sub-inhibitory concentrations of amoxicillin. First, capsule expression was monitored by qRT-PCR when S. suis was cultivated in the presence of amoxicillin. Then, the pro-inflammatory potential of S. suis P1/7 culture supernatants or whole cells conditioned with amoxicillin was evaluated by monitoring the activation of the NF-κB pathway in monocytes and quantifying pro-inflammatory cytokines secreted by macrophages. It was found that amoxicillin decreased capsule expression in S. suis. Moreover, conditioning the bacterium with sub-inhibitory concentrations of amoxicillin caused an increased activation of the NF-κB pathway in monocytes following exposure to bacterial culture supernatants and to a lesser extent to whole bacterial cells. This was associated with an increased secretion of pro-inflammatory cytokines (CXCL8, IL-6, IL-1β) by macrophages. This study identified a new mechanism by which S. suis may increase its inflammatory potential in the presence of sub-inhibitory concentrations of amoxicillin, a cell wall-active antibiotic, thus challenging its use for preventive treatments or as growth factor. PMID:27104570
Pigs are the natural host for Chlamydia suis, a pathogen which is phylogenetically highly related to the human pathogen C. trachomatis. Chlamydia suis infections are generally treated with tetracyclines. In 1998, tetracyline resistant C. suis strains emerged on U.S. pig farms and they are currently present in the Belgian, Cypriote, German, Israeli, Italian and Swiss pig industry. Infections with tetracycline resistant C. suis strains are mainly associated with severe reproductive failure leading to marked economical loss. We developed a sensitive and specific TaqMan probe-based C. suis real-time PCR for examining clinical samples of both pigs and humans. The analytical sensitivity of the real-time PCR is 10 rDNA copies/reaction without cross-amplifying DNA of other Chlamydia species. The PCR was successfully validated using conjunctival, pharyngeal and stool samples of slaughterhouse employees, as well as porcine samples from two farms with evidence of reproductive failure and one farm without clinical disease. Chlamydia suis was only detected in diseased pigs and in the eyes of humans. Positive humans had no clinical complaints. PCR results were confirmed by culture in McCoy cells. In addition, Chlamydia suis isolates were also examined by the tet(C) PCR, designed for demonstrating the tetracycline resistance gene tet(C). The tet(C) gene was only present in porcine C. suis isolates. PMID:24816542
Hammerl, Jens A.; Göllner, Cornelia; Jäckel, Claudia; Scholz, Holger C.; Nöckler, Karsten; Reetz, Jochen; Al Dahouk, Sascha; Hertwig, Stefan
Virulent phages have been used for many years to type Brucella isolates, but until recently knowledge about the genetic makeup of these phages remains limited. In this work the host specificity and genomic sequences of the original set (deposited in 1960) of VLA Brucella reference phages Tb, Fi, Wb, Bk2, R/C, and Iz were analyzed and compared with hitherto described brucellaphages. VLA phages turned out to be different from homonymous phages in other laboratories. The host range of the phages was defined by performing plaque assays with a wide selection of Brucella strains. Propagation of the phages on different strains did not alter host specificity. Sequencing of the phages TbV, FiV, WbV, and R/CV revealed nucleotide variations when compared to same-named phages previously described by other laboratories. The phages Bk2V and IzV were sequenced for the first time. While Bk2V exhibited the same deletions as WbV, IzV possesses the largest genome of all Brucella reference phages. The duplication of a 301 bp sequence in this phage and the large deletion in Bk2V, WbV, and R/CV may be a result of recombination caused by repetitive sequences located in this DNA region. To identify new phages as potential candidates for lysotyping, the host range and Single Nucleotide Polymorphisms (SNPs) of 22 non-reference Brucella phages were determined. The phages showed lysis patterns different from those of the reference phages and thus represent novel valuable candidates in the typing set. PMID:28360895
Weinert, Lucy A; Chaudhuri, Roy R; Wang, Jinhong; Peters, Sarah E; Corander, Jukka; Jombart, Thibaut; Baig, Abiyad; Howell, Kate J; Vehkala, Minna; Välimäki, Niko; Harris, David; Chieu, Tran Thi Bich; Van Vinh Chau, Nguyen; Campbell, James; Schultsz, Constance; Parkhill, Julian; Bentley, Stephen D; Langford, Paul R; Rycroft, Andrew N; Wren, Brendan W; Farrar, Jeremy; Baker, Stephen; Hoa, Ngo Thi; Holden, Matthew T G; Tucker, Alexander W; Maskell, Duncan J
Streptococcus suis causes disease in pigs worldwide and is increasingly implicated in zoonotic disease in East and South-East Asia. To understand the genetic basis of disease in S. suis, we study the genomes of 375 isolates with detailed clinical phenotypes from pigs and humans from the United Kingdom and Vietnam. Here, we show that isolates associated with disease contain substantially fewer genes than non-clinical isolates, but are more likely to encode virulence factors. Human disease isolates are limited to a single-virulent population, originating in the 1920, s when pig production was intensified, but no consistent genomic differences between pig and human isolates are observed. There is little geographical clustering of different S. suis subpopulations, and the bacterium undergoes high rates of recombination, implying that an increase in virulence anywhere in the world could have a global impact over a short timescale.
Soares, Taíssa Cook Siqueira; Paes, Antonio Carlos; Megid, Jane; Ribolla, Paulo Eduardo Martins; Paduan, Karina dos Santos; Gottschalk, Marcelo
Streptococcus suis is an important pathogen in the swine industry. This study is the first to report on the antimicrobial susceptibility of S. suis isolated from clinically healthy pigs in Brazil; the fourth major pork producer in the world. The antimicrobial susceptibility of 260 strains was determined by disc diffusion method. Strains were commonly susceptible to ceftiofur, cephalexin, chloramphenicol, and florfenicol, with more than 80% of the strains being susceptible to these antimicrobials. A high frequency of resistance to some of the antimicrobial agents was demonstrated, with resistance being most common to sulfa-trimethoprim (100%), tetracycline (97.69%), clindamycin (84.61%), norfloxacin (76.92%), and ciprofloxacin (61.15%). A high percentage of multidrug resistant strains (99.61%) were also found. The results of this study indicate that ceftiofur, cephalexin, and florfenicol are the antimicrobials of choice for empirical control of the infections caused by S. suis. PMID:24688177
Nga, Tran Vu Thieu; Nghia, Ho Dang Trung; Tu, Le Thi Phuong; Diep, To Song; Mai, Nguyen Thi Hoang; Chau, Tran Thi Hong; Sinh, Dinh Xuan; Phu, Nguyen Hoan; Nga, Tran Thi Thu; Chau, Nguyen Van Vinh; Campbell, James; Hoa, Ngo Thi; Chinh, Nguyen Tran; Hien, Tran Tinh; Farrar, Jeremy; Schultsz, Constance
Streptococcus suis serotype 2 is an emerging zoonotic pathogen and is the main cause of acute bacterial meningitis in adult patients in Vietnam. We developed an internally controlled real-time PCR for detection of S. suis serotype 2 in cerebrospinal fluid (CSF) samples targeted at the cps2J gene. Sensitivity and specificity in culture-confirmed clinical samples were 100%. The PCR detected S. suis serotype 2 infection in 101 of 238 (42.4%) prospectively collected CSF samples, of which 55 (23%) were culture positive. Culture-negative but PCR-positive CSF samples were significantly associated with the use of antimicrobial agents before admission. S. suis serotype 2 infection was more common than infections with Streptococcus pneumoniae and Neisseria meningitidis combined. Our results strikingly illustrate the additional diagnostic value of PCR in patients who are pretreated with antimicrobial agents and demonstrate the extremely high prevalence of S. suis infections among Vietnamese adult patients with bacterial meningitis. PMID:21767702
Bamaiyi, P H; Hassan, L; Khairani-Bejo, S; Zainal Abidin, M; Ramlan, M; Krishnan, N; Adzhar, A; Abdullah, N; Hamidah N, H M; Norsuhanna, M M; Hashim, S N
A study was carried out to isolate Brucella melitensis using established bacteriological and PCR techniques in Brucella seropositive goats in farms in Selangor, Negeri Sembilan, Melaka and Pulau Pinang. Brucella melitensis was isolated from 7 of 134 reactors with the highest isolation from the vaginal swabs (57.14%) followed by the spleen (28.57%), uterine fluid (14.29%). No Brucella was isolated from the lymph nodes. PCR confirmed all the seven isolates as B. melitensis and isolates were phylogenetically related to other isolates from India, Iran, and Israel but most closely related to isolates from Singapore.
Zaccaria, Edoardo; Wels, Michiel; van Baarlen, Peter; Wells, Jerry M.
In S. suis the ComX-inducing peptide (XIP) pheromone regulates ComR-dependent transcriptional activation of comX (or sigX) the regulator of the late competence regulon. The aims of this study were to identify the ComR-regulated genes and in S. suis using genome-wide transcriptomics and identify their function based on orthology and the construction of specific knockout mutants. The ComX regulon we identified, includes all homologs of the “transformasome” a type 4-like pilus DNA binding and transport apparatus identified in Streptococcus pneumoniae, Streptococcus mutans, and Streptococcus thermophilus. A conserved CIN-box (YTACGAAYW), predicted to be bound by ComX, was found in the promoters of operons encoding genes involved in expression of the transformasome. Mutants lacking the major pilin gene comYC were not transformable demonstrating that the DNA uptake pilus is indeed required for competence development in S. suis. Competence was a transient state with the comX regulon shut down after ~15 min even when transcription of comX had not returned to basal levels, indicating other mechanisms control the exit from competence. The ComX regulon also included genes involved in DNA repair including cinA which we showed to be required for high efficiency transformation. In contrast to S. pneumoniae and S. mutans the ComX regulon of S. suis did not include endA which converts the transforming DNA into ssDNA, or ssbA, which protects the transforming ssDNA from degradation. EndA appeared to be essential in S. suis so we could not generate mutants and confirm its role in DNA transformation. Finally, we identified a putative homolog of fratricin, and a putative bacteriocin gene cluster, that were also part of the CIN-box regulon and thus may play a role in DNA release from non-competent cells, enabling gene transfer between S. suis pherotypes or S. suis and other species. S. suis mutants of oppA, the binding subunit of the general oligopeptide transporter were not
Teerasukjinda, Ornusa; Yee, Melvin; Chung, Heath H
Background: Streptococcus suis meningoencephalitis is a rare but increasingly important condition. Good history taking will give clues to the diagnosis. This is the fourth case report in the United States. Case: A 52-year-old Filipino man who recently returned from a trip to the Philippines was admitted with classic symptoms of bacterial meningitis. His cerebrospinal fluid culture grew Streptococcus suis. His clinical course was complicated by seizures, hearing loss, and permanent tinnitus. Conclusion: Clinicians should be aware of this emerging disease especially in patients with recent travel history to endemic areas. Early recognition and appropriate management could potentially prevent complications. PMID:25285249
SUBTITLE Effects of Opsonization and Gamma Interferon on Growth of Brucella , melitensis 16M in Mouse Peritoneal Microphages rom In Vitro 3. REPORT...with Brucella melitensis 16M treated with complement- and/or antibody-rich serum. Mouse serum rich in antibody against Brucella lipopolysaccnaride...pathogens of humans and livestock. Brucella meli- tensis usually infects sheep, goats , and camels and is the most pathogenic species for humans (1). Like
Chauhan, H. C.; Chandel, B. S.; Patel, Kirit B.; Patel, A. C.; Shrimali, M. D.; Patel, S. S.; Bhagat, A. G.; Rajgor, Manish; Patel, Mitul A.; Patel, Maulik; Kala, Jitendra; Patel, Bhumika
Brucella abortus is generally known to cause brucellosis in cattle and buffalo. Here, we report the draft genome sequence of Brucella abortus SKN 13, isolated from aborted cattle placenta in the area of Gujarat, India, providing precious resources for comparative genomic analyses of Brucella field strains. PMID:27789633
Kubler-Kielb, Joanna; Vinogradov, Evgeny
O-Specific polysaccharides of Brucella contain two antigenic determinants, called A and M. Most of the strains express epitope A with a small amount of epitope M, whereas Brucella melitensis strain 16 M expresses longer polymer consisting mostly of M-type epitopes. Proposed explanation was that epitope A is defined by 1-2-linked homopolymer of N-formylperosamine (Rha4NFo), while epitope M is a pentasaccharide with four 2- and one 3-substituted Rha4NFo. We reinvestigated both types of structures by 2D NMR and showed that M-epitope is a tetrasaccharide, missing one of the 2-linked Rha4NFo as compared to the previously proposed structure. Polysaccharide from B. melitensis 16 M contains a fragment of 1-2-linked polymer, capped with M-type polymer. Other strains contain one or two M-type units at the non-reducing end of the 1-2-linked O-chain.
De Bolle, Xavier; Crosson, Sean; Matroule, Jean-Yves; Letesson, Jean-Jacques
Brucellae are facultative intracellular pathogens. The recent development of methods and genetically engineered strains allowed the description of cell-cycle progression of Brucella abortus, including unipolar growth and the ordered initiation of chromosomal replication. B. abortus cell-cycle progression is coordinated with intracellular trafficking in the endosomal compartments. Bacteria are first blocked at the G1 stage, growth and chromosome replication being resumed shortly before reaching the intracellular proliferation compartment. The control mechanisms of cell cycle are similar to those reported for the bacterium Caulobacter crescentus, and they are crucial for survival in the host cell. The development of single-cell analyses could also be applied to other bacterial pathogens to investigate their cell-cycle progression during infection.
Erdenebaatar, Janchivdorj; Bayarsaikhan, Balgan; Watarai, Masahisa; Makino, Sou-ichi; Shirahata, Toshikazu
Enzyme-linked immunosorbent assays using antigens extracted from Brucella abortus with n-lauroylsarcosine differentiated natural Brucella-infected animals from Brucella-vaccinated or Yersinia enterocolitica O9-infected animals. A field trial in Mongolia showed cattle, sheep, goat, reindeer, camel, and human sera without infection could be distinguished from Brucella-infected animals by conventional serological tests.
Mundt, H-C; Joachim, A; Becka, M; Daugschies, A
Piglets experimentally infected with 10,000 oocysts of Isospora suis in three identical trials (n = 50) were examined clinically and coproscopically from 5 to 11 days post-infection (d.p.i.), weighed in weekly intervals until the fourth week of life and compared to age-matched asymptomatic controls (n = 17). Furthermore, 17 infected piglets were histologically examined on days 5-14 p.i. Infected animals had a significantly lower weight gain than the controls and showed diarrhoea throughout, with maximum prevalence and intensity on 6 d.p.i. Half of the animals had diarrhoea for only 2 days or less. The number of diarrhoea days was negatively correlated with weight gain. Oocyst excretion started on 5 d.p.i. with peak prevalences and declined afterwards; a smaller peak was seen on 10 d.p.i. All animals excreted parasites at least once, and most of them excreted for 5-7 days. Oocyst excretion intensity paralleled the prevalence and ranged from 220 to 251,501 oocysts per gram of faeces (opg). Most samples contained 4 x 10(3) to 4 x 10(4) opg. The opg values were negatively correlated with faecal scores (samples with diarrhoea contained less oocysts) of the same day and the previous day. Histologically, necrosis followed by atrophy of the villi was most pronounced in the early stage of infection throughout the jejunum and ileum but declined thereafter. On 14 d.p.i., villous atrophy was still noticeable in the jejunum. Histology is difficult to quantify and requires large animal numbers, although the effects are visible for some time. Weight gain and faecal score can be affected by other factors than parasite infection. From the compiled data, we conclude that the established model is suitable to study piglet isosporosis with oocyst excretion being the most reliable parameter, although individual variations are considerable. A negative correlation between excretion and diarrhoea may be responsible for the difficulties in the detection of the parasite in field samples.
Pregnant mice were challenged at Day 3, 7, 11 or 15 of pregnancy with Brucella abortus Strain 544 and killed at Day 18 of pregnancy for the enumeration of brucella in the spleens and individual placentas. Whatever the route of challenge--i.p., i.v. or s.c. into the foot-pad (F-s.c.) no abortions or foetal deaths were observed. Placental colonization involved either all, none or only some of the placentas in the same uterus (partial placental colonization: 25% of the mice). In the latter case, the probability of colonization was the same for all sites of implantation. Placentas were independent units as regards colonization and bacterial proliferation. Placental colonization was expressed either by (1) the class of placental infection within the uterus, which might be total, partial or nil; (2) the ratio of infected to total placentas analysed per group; or (3) the mean degree of infection per group. Whatever means of expression was chosen, placental colonization increased with the dose of challenge in parallel with splenic infection in the mouse. The challenge doses required at Day 7 to infect 50% of the placentas differed according to the route (i.p. = 54; i.v. = 5.6 x 10(2) and F-s.c. = 3.6 x 10(4) brucella). Placentas were more frequently and more intensively colonized when the challenge was performed at Days 7 and 11 than at Days 3 and 15 at pregnancy. Mice immunized with H.38 B. melitensis killed vaccine 36 days before pregnancy were found to be protected against an i.p. challenge with 2 x 10(5) brucella at Day 7 of pregnancy. PMID:6775668
Meng, Kai; Sun, Wenjing; Zhao, Peng; Zhang, Limei; Cai, Dongjie; Cheng, Ziqiang; Guo, Huijun; Liu, Jianzhu; Yang, Dubao; Wang, Shujing; Chai, Tongjie
A one-step immunochromatographic assay using gold nanoparticles coated with polyclonal antibody (pAb) against Mycoplasma suis (M. suis) was developed in this study for the detection of M. suis in porcine plasma. The colloidal gold was prepared by the reduction of gold salt with sodium citrate coupled with pAb against M. suis. The pAb was produced by immunizing the BALB/c mice with recombinant MSG1 (rMSG1) protein from M. suis expressed in Escherichia coli. The optimal concentrations of the capture antibody and the coating antibody were 12 μg/ml and 1.5 mg/ml, respectively, and that of the blocking buffer was 1% bovine serum albumin. The lower detection limit of the immunochromatographic assay test was 100 ng/ml with visual detection under optimal conditions of analysis. Classical swine fever virus, porcine reproductive and respiratory syndrome virus, swine pneumonia mycoplasma, swine toxoplasma, and porcine parvovirus were used to evaluate the specificity of the immunochromatographic strips. No cross-reaction of the antibodies with other related swine pathogens was observed. This qualitative test based on the visual evaluation of the results did not require any equipment. The assay time for M. suis detection was less than 10 min, suitable for rapid detection at the grassroots level. The one-step colloidal gold immunochromatographic strips that we developed had high specificity and sensitivity. Therefore, this method would be feasible, convenient, rapid, and effective for detecting M. suis in porcine plasma.
Ye, Huiyan; Cai, Mingzhu; Zhang, Huimin; Li, Zhencui; Wen, Ronghui; Feng, Youjun
Biotin protein ligase is universal in three domains of life. The paradigm version of BPL is the Escherichia coli BirA that is also a repressor for the biotin biosynthesis pathway. Streptococcus suis, a leading bacterial agent for swine diseases, seems to be an increasingly-important opportunistic human pathogen. Unlike the scenario in E. coli, S. suis lacks the de novo biotin biosynthesis pathway. In contrast, it retains a bioY, a biotin transporter-encoding gene, indicating an alternative survival strategy for S. suis to scavenge biotin from its inhabiting niche. Here we report functional definition of S. suis birA homologue. The in vivo functions of the birA paralogue with only 23.6% identity to the counterpart of E. coli, was judged by its ability to complement the conditional lethal mutants of E. coli birA. The recombinant BirA protein of S. suis was overexpressed in E. coli, purified to homogeneity and verified with MS. Both cellulose TLC and MALDI-TOFF-MS assays demonstrated that the S. suis BirA protein catalyzed the biotinylation reaction of its acceptor biotin carboxyl carrier protein. EMSA assays confirmed binding of the bioY gene to the S. suis BirA. The data defined the first example of the bifunctional BirA ligase/repressor in Streptococcus. PMID:27217336
Yuan, Fangyan; Tan, Chen; Liu, Zewen; Yang, Keli; Zhou, Danna; Liu, Wei; Duan, Zhengying; Guo, Rui; Chen, Huanchun; Tian, Yongxiang; Bei, Weicheng
Streptococcus suis serotype 2 is a major zoonotic pathogen, and the two-component system plays an important role in bacterial pathogenesis. The present study targeted the 1910HK/RR two-component system of S. suis 2. A 1910HK/RR deletion mutant (Δ1910HK/RR) and the corresponding complementation strain (CΔ1910HK/RR) were constructed in S. suis 2 strain 05ZYH33. 1910HK/RR deletion had no effect on S. suis 2 growth, but significantly inhibited the adherence and invasion of S. suis 2 to HEp-2 cells. Analysis of the role of 1910HK/RR in murine and pig infection models demonstrated that 1910HK/RR played a distinct role in the virulence of S. suis 2. In addition, deletion of 1910HK/RR significantly impaired the survival of 05ZYH33 in human blood. These data provided important insights into the pathogenesis of S. suis 2.
Pan, Zihao; Ma, Ye; Ma, Jiale; Dong, Wenyang; Yao, Huochun
The two opportunistic pathogens, Streptococcus suis (S. suis) and Aerococcus. viridans (A. viridans) were isolated from the brains of piglets suffered bacterial meningitis in a farm of China. The murine model has been established to evaluate the pathogenicity and symbiotic relationship of S. suis and A. viridans simultaneously infection. Our results demonstrated the ability of new serotype S. suis to cause the classical bacterial meningitis and death were greatly enhanced during co-infection with A. viridans in mice at a proportion. We also examined the distribution and titer of bacteria coinfection in organs, the titer of S. suis appeared a significant trend for an increase in the lung meanwhile the concentration titer of A. viridans maintain a low level. This is the first reported the A. viridans and S. suis coinfection cause the bacterial meningitis outbroke in the piglets and mice. Moreover, further investigation of the pathogenesis of A. viridans and S. suis is urgently needed in swine industry.
Celebi, Güven; Külah, Canan; Kiliç, Selçuk; Ustündağ, Gonca
Brucellosis is a zoonotic disease and virtually all infections derived from exposure to animals or ingestion of unpasteurized dairy products. Brucellosis among family members has been reported. However, screening household members of an index case of acute brucellosis is not a routine procedure. A 10-y-old boy was diagnosed with acute brucellosis. Unpasteurized goat cheese commonly consumed within the family was thought to be the possible source of the bacteria. The family (parents, sister and brother) was screened with physical examination, serum tube agglutination test, blood cultures and routine laboratory tests. Three additional cases (parents and sister) of serological and culture proven brucellosis were detected. Two of them (mother and sister) were asymptomatic and had no clinical findings. Brucella melitensis biovar 3 was isolated from breast milk culture and from all blood cultures of 4 brucellosis cases. In conclusion, brucellosis, even with bacteraemia, can be completely asymptomatic. Consumption of raw milk products by household members is a common risk factor for brucellosis outbreak among family members. Thus, screening household members of an index case of brucellosis can expose new brucellosis cases.
Thepsuriyanont, Pikun; Intarapuk, Apiradee; Chanket, Panita; Tunyong, Wittawat; Kalambaheti, Thareerat
Control of brucellosis among farm animals, wildlife and humans require reliable diagnosis. Rose Bengal serological test (RBT) is based on lipopolysaccharide antigen of Brucella, which may cross react with other gram-negative bacteria and produce false positive result. Immunoreactive proteins, such as outer-membrane protein BP26, ribosome recycling factor protein CP24 and Brucella lumazine synthase (BLS), previously reported to be recognized by infected sheep sera, were selected for production of recombinant proteins for use in an ELISA in order to investigate immune response among goats and cows, in comparison with commercial RBT. Cut-off value for ELISA was based on the immune response of in vitro fertilized goats and cows. Goats positive for Brucella culture or by RBT were ELISA positive for either IgG or IgM against at least one recombinant protein. For animals with negative RBT, animals with positive ELISA could be detected, and 61.6% possessed ELISA values as high as in infected animals. Thus, this ELISA procedure is proposed as an alternative to RBT for screening of brucellosis in farm animals.
Alizadeh, Hamed; Salouti, Mojtaba; Shapouri, Reza
Background: Brucellosis is an infectious disease that is caused by Brucella spp. As Brucella spp. are intramacrophage pathogens, the treatment of this infection is very difficult. On the other hand, due to the side effects of the brucellosis treatment regime, it is necessary to find new antimicrobial agents against it. Objectives: The aim of this study was to investigate the antimicrobial effect of silver nanoparticles against Brucella abortus 544 in the intramacrophage condition. Materials and Methods: The antimicrobial effect of silver nanoparticles was determined by an agar well diffusion method. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of silver nanoparticles against B. abortus 544 were determined by a broth macrodilution method. The effect of time on the antimicrobial activity of silver nanoparticles was analyzed. The effect of silver nanoparticles on the intramacrophage survival of B. abortus 544 was studied on mice peritoneal macrophages. Results: The well diffusion agar study showed that silver nanoparticles have an antimicrobial effect on B. abortus 544. The MIC and MBC of silver nanoparticles against B. abortus 544 were; 6 ppm and 8 ppm, respectively. The silver nanoparticles showed antibacterial effects within 40 minutes. The results of the macrophage culture indicated that silver nanoparticles have antibacterial activity against intramacrophage B. abortus 544, and the highest efficiency was observed at a concentration of 8-10 ppm of silver nanoparticles. Conclusions: The results showed that silver nanoparticles have an antimicrobial effect against intramacrophage B. abortus 544. PMID:25147682
Brucellosis is a zoonosis that preceded humans but continues to cause significant medical, veterinary and socioeconomic problems, mainly because its overall burden remains underestimated and neglected. Its ecology, or what we know of it, has evolved rapidly in recent years. Two novel species, Brucella ceti and B. pinnipedialis, with the potential for causing human disease have been isolated from marine mammals. Another novel species, B. microti, has been isolated from wildlife animals, whilst B. inopinata has been isolated from a human case. An active spillover of Brucella between domestic animals and wildlife is also being recognised, with elk transmitting B. abortus to cattle, and freshwater fish becoming infected with B. melitensis from waste meat. In recent years the global epidemiology of the disease has not altered drastically, apart from increased awareness of brucellosis in sub-Saharan Africa and a rapid expansion of disease endemicity in the Balkan Peninsula. Isolated stories and events underline that Brucella knows no borders. The modern world has offered the pathogen the ability to travel and manifest itself anywhere and has also offered scientists the ability to track these manifestations better than ever before. This may allow the disease to be neglected no longer, or at least to be recognised as neglected.
de Jong, Maarten F; Rolán, Hortensia G; Tsolis, Renée M
In humans, pathogenic Brucella species cause a febrile illness known as brucellosis. A key pathogenic trait of this group of organisms is their ability to survive in immune cells and persist in tissues of the reticuloendothelial system, a process that requires the function of a Type IV secretion system. In contrast to other well-studied Gram-negative bacteria, Brucella spp. do not cause inflammation at the site of invasion, but have a latency period of 2-4 weeks before the onset of symptoms. This review discusses several mechanisms that allow Brucella spp. both to evade detection by pattern recognition receptors of the innate immune system and suppress their signalling. In contrast to these stealth features, the VirB Type IV secretion system, which mediates survival within phagocytic cells, stimulates innate immune responses in vivo. The responses stimulated by this virulence factor are sufficient to check bacterial growth, but not to elicit sterilizing immunity. The result is a stand-off between host and pathogen that results in persistent infection.
Zheng, Chengkun; Ren, Sujing; Xu, Jiali; Zhao, Xigong; Shi, Guolin; Wu, Jianping; Li, Jinquan; Chen, Huanchun; Bei, Weicheng
Streptococcus suis is a major swine and zoonotic pathogen that causes severe infections. Previously, we identified 2 Spx regulators in S. suis, and demonstrated that SpxA1 affects oxidative stress tolerance and virulence. However, the mechanism behind SpxA1 function remains unclear. In this study, we targeted 4 genes that were expressed at significantly reduced levels in the spxA1 mutant, to determine their specific roles in adaptation to oxidative stress and virulence potential. The Δnox strain exhibited impaired growth under oxidative stress conditions, suggesting that NADH oxidase is involved in oxidative stress tolerance. Using murine and pig infection models, we demonstrate for the first time that NADH oxidase is required for virulence in S. suis 2. Furthermore, the enzymatic activity of NADH oxidase has a key role in oxidative stress tolerance and a secondary role in virulence. Collectively, our findings reveal that NADH oxidase plays an important part in SpxA1 function and provide a new insight into the pathogenesis of S. suis 2.
Streptococcus suis is a swine pathogen responsible for economic losses to the pig industry worldwide. Additionally, it is a zoonotic agent that can cause severe infections in those in close contact with infected pigs and/or who consume uncooked or undercooked pork products. Here, we report nine draf...
Niestrath, M; Takla, M; Joachim, A; Daugschies, A
In order to evaluate the prevalence of Isospora suis in conventional piglet production in Germany, pooled faecal samples from 327 pig litters from 18 pig production units (20-320 sows each) were examined. At least 10 litters from each farm were investigated. I. suis was present on 83% of the farms and 42.5% of the litters, the infection rate being highest in the third week of age (48.2%). I. suis was found more frequently in samples of diarrhoea than in firm faeces (49.2% compared to 22.2%). Twenty naturally infected piglets from six of these farms underwent examination post mortem, including histology, virology and bacteriology. Histological examination revealed atrophy of the villi in various degrees, mild crypt hyperplasia, fusion of the villi, metaplastic epithelium, erosions and necrosis, especially in the medium and the posterior jejunum and in the ileum. Asexual and sexual developmental stages of the parasite were found in varying numbers in the epithelium of the whole of the small intestine. Bacteria and viruses were mostly excluded as the cause of diarrhoea, and it was concluded that I. suis was the primary pathogen inducing distinct changes and clinical symptoms of diarrhoea.
Martel, A; Baele, M; Devriese, L A; Goossens, H; Wisselink, H J; Decostere, A; Haesebrouck, F
Eighty-seven Streptococcus suis isolates recovered in 1999-2000 from diseased pigs, all from different farms, were screened for resistance against macrolide and lincosamide antibiotics by the disk diffusion and agar dilution test and a PCR assay, amplifying the ermB gene and the mefA/E gene. Seventy-one percent of the isolates showed constitutive resistance to macrolide and lincosamide antibiotics (MLS(B)-phenotype). All these isolates were positive for the ermB gene in the PCR, but negative for the mefA/E gene. For all strains minimum inhibitory concentrations (MIC) against five other antimicrobial agents were determined. All strains were susceptible to penicillin. Ninety-nine percent of the isolates were susceptible to enrofloxacin and tiamulin. Eighty-five percent of the strains were resistant to doxycycline. A 540bp fragment of the ermB genes of eight S. suis strains was sequenced and compared with ermB genes of five S. pneumoniae and five S. pyogenes strains of human origin. A 100% homology was found between these fragments in seven S. suis, one S. pneumoniae and three of the S. pyogenes isolates. This study demonstrates that resistance against macrolides, lincosamides and streptogramin B is widespread in S. suis and mediated by ribosome methylation, encoded by the ermB gene.
Zaccaria, Edoardo; Wells, Jerry M.
Helminth infection in pigs serves as an excellent model for the study of the interaction between human malnutrition and parasitic infection and could have important implications in human health. We had observed that pigs infected with Trichuris suis for 21 days showed significant changes in the prox...
The similar biology of several helminth infections in pigs and humans provides an excellent animal model to study the interaction between the host and parasite infection that could have important consequences for human health. We had observed that pigs infected with the whipworm Trichuris suis for 2...
Liang, Yan; Salim, Abdulbaset M.; Wu, Wendy; Kilgore, Paul E.
Early Chinese texts contain extensive disease descriptions, including various texts that contain descriptions of modern-day conditions. During the Sui Dynasty, a leading scholar, Chao Yuanfang, may have authored a leading treatise 1400 years ago. Although these texts are the subject of ongoing research, evidence suggests that a clinical syndrome consistent with pertussis was observed in ancient China. PMID:26977422
Hansen, Tina V. A.; Nejsum, Peter; Friis, Christian; Olsen, Annette; Thamsborg, Stig Milan
Background The single-dose benzimidazoles used against Trichuris trichiura infections in humans are not satisfactory. Likewise, the benzimidazole, fenbendazole, has varied efficacy against Trichuris suis whereas Oesophagostomum dentatum is highly sensitive to the drug. The reasons for low treatment efficacy of Trichuris spp. infections are not known. Methodology We studied the effect of fenbendazole, albendazole and levamisole on the motility of T. suis and O. dentatum and measured concentrations of the parent drug compounds and metabolites of the benzimidazoles within worms in vitro. The motility and concentrations of drug compounds within worms were compared between species and the maximum specific binding capacity (Bmax) of T. suis and O. dentatum towards the benzimidazoles was estimated. Comparisons of drug uptake in living and killed worms were made for both species. Principal findings The motility of T. suis was generally less decreased than the motility of O. dentatum when incubated in benzimidazoles, but was more decreased when incubated in levamisole. The Bmax were significantly lower for T. suis (106.6, and 612.7 pmol/mg dry worm tissue) than O. dentatum (395.2, 958.1 pmol/mg dry worm tissue) when incubated for 72 hours in fenbendazole and albendazole respectively. The total drug concentrations (pmol/mg dry worm tissue) were significantly lower within T. suis than O. dentatum whether killed or alive when incubated in all tested drugs (except in living worms exposed to fenbendazole). Relatively high proportions of the anthelmintic inactive metabolite fenbendazole sulphone was measured within T. suis (6–17.2%) as compared to O. dentatum (0.8–0.9%). Conclusion/Significance The general lower sensitivity of T. suis towards BZs in vitro seems to be related to a lower drug uptake. Furthermore, the relatively high occurrence of fenbendazole sulphone suggests a higher detoxifying capacity of T. suis as compared to O. dentatum. PMID:24699263
Seele, Jana; Nau, Roland; Prajeeth, Chittappen K; Stangel, Martin; Valentin-Weigand, Peter; Seitz, Maren
Streptococcus (S.) suis infections are the most common cause of meningitis in pigs. Moreover, S. suis is a zoonotic pathogen, which can lead to meningitis in humans, mainly in adults. We assume that glial cells may play a crucial role in host-pathogen interactions during S. suis infection of the central nervous system. Glial cells are considered to possess important functions during inflammation and injury of the brain in bacterial meningitis. In the present study, we established primary astrocyte-microglial cell co-cultures to investigate interactions of S. suis with glial cells. For this purpose, microglial cells and astrocytes were isolated from new-born mouse brains and characterized by flow cytometry, followed by the establishment of astrocyte and microglial cell mono-cultures as well as astrocyte-microglial cell co-cultures. In addition, we prepared microglial cell mono-cultures co-incubated with uninfected astrocyte mono-culture supernatants and astrocyte mono-cultures co-incubated with uninfected microglial cell mono-culture supernatants. After infection of the different cell cultures with S. suis, bacteria-cell association was mainly observed with microglial cells and most prominently with a non-encapsulated mutant of S. suis. A time-dependent induction of NO release was found only in the co-cultures and after co-incubation of microglial cells with uninfected supernatants of astrocyte mono-cultures mainly after infection with the capsular mutant. Only moderate cytotoxic effects were found in co-cultured glial cells after infection with S. suis. Taken together, astrocytes and astrocyte supernatants increased interaction of microglial cells with S. suis. Astrocyte-microglial cell co-cultures are suitable to study S. suis infections and bacteria-cell association as well as NO release by microglial cells was enhanced in the presence of astrocytes.
Guimaraes, Ana M. S.; Santos, Andrea P.; SanMiguel, Phillip; Walter, Thomas; Timenetsky, Jorge; Messick, Joanne B.
Mycoplasma suis, the causative agent of porcine infectious anemia, has never been cultured in vitro and mechanisms by which it causes disease are poorly understood. Thus, the objective herein was to use whole genome sequencing and analysis of M. suis to define pathogenicity mechanisms and biochemical pathways. M. suis was harvested from the blood of an experimentally infected pig. Following DNA extraction and construction of a paired end library, whole-genome sequencing was performed using GS-FLX (454) and Titanium chemistry. Reads on paired-end constructs were assembled using GS De Novo Assembler and gaps closed by primer walking; assembly was validated by PFGE. Glimmer and Manatee Annotation Engine were used to predict and annotate protein-coding sequences (CDS). The M. suis genome consists of a single, 742,431 bp chromosome with low G+C content of 31.1%. A total of 844 CDS, 3 single copies, unlinked rRNA genes and 32 tRNAs were identified. Gene homologies and GC skew graph show that M. suis has a typical Mollicutes oriC. The predicted metabolic pathway is concise, showing evidence of adaptation to blood environment. M. suis is a glycolytic species, obtaining energy through sugars fermentation and ATP-synthase. The pentose-phosphate pathway, metabolism of cofactors and vitamins, pyruvate dehydrogenase and NAD+ kinase are missing. Thus, ribose, NADH, NADPH and coenzyme A are possibly essential for its growth. M. suis can generate purines from hypoxanthine, which is secreted by RBCs, and cytidine nucleotides from uracil. Toxins orthologs were not identified. We suggest that M. suis may cause disease by scavenging and competing for host' nutrients, leading to decreased life-span of RBCs. In summary, genome analysis shows that M. suis is dependent on host cell metabolism and this characteristic is likely to be linked to its pathogenicity. The prediction of essential nutrients will aid the development of in vitro cultivation systems. PMID:21573007
Nichols, Megin; Thompson, Deborah; Carothers, Joshua T.; Klauber, Judy; Stoddard, Robyn A.; Guerra, Marta A.; Benoit, Tina J.; Traxler, Rita M.
We describe a periprosthetic Brucella abortus infection in a case-patient undergoing hip replacement revision surgery, and the subsequent investigation of laboratory and surgical staff exposures. Although exposures are rare, it is important to have infection prevention recommendations for surgical procedures among patients with suspected or unidentified Brucella spp. infection. PMID:25026630
Hammerl, J A; Ulrich, R G; Imholt, C; Scholz, H C; Jacob, J; Kratzmann, N; Nöckler, K; Al Dahouk, S
Brucellosis is a widespread zoonotic disease introduced from animal reservoirs to humans. In Germany, bovine and ovine/caprine brucellosis were eradicated more than a decade ago and mandatory measures in livestock have been implemented to keep the officially brucellosis-free status. In contrast, surveillance of wildlife is still challenging, and reliable data on the prevalence of brucellae in small mammal populations do not exist. To assess the epidemiology of Brucella spp. in rodents and shrews, a molecular survey was carried out. A total of 537 rodents and shrews were trapped in four federal states located throughout Germany and investigated for the presence of Brucella. Using a two-step molecular assay based on the detection of the Brucella-specific bcsp31 and IS711 sequences in tissue samples, 14.2% (n = 76) of the tested animals were positive. These originated mainly from western and south-western Germany, where preliminary analyses indicate population density-dependent Brucella prevalence in voles (Myodes glareolus) and mice (Apodemus spp.). recA typing revealed a close relationship to a potentially novel Brucella species recently isolated from red foxes (Vulpes vulpes) in Austria. The molecular detection of brucellae in various rodent taxa and for the first time in shrew species shows that these animals may be naturally infected or at least have a history of exposure to Brucella spp.
Campos, Priscila Carneiro; Gomes, Marco Túlio Ribeiro; Guimarães, Gabriela; Costa Franco, Miriam Maria Silva; Marim, Fernanda Martins; Oliveira, Sergio Costa
Immunity against Brucella abortus depends on the recognition of pathogen-associated molecular patterns (PAMPs) by pattern recognition receptors (PRRs). Signaling pathways triggered by Brucella DNA involves TLR9, AIM2 and possibly STING and MAVS. Herein, we review the advances in B. abortus DNA sensing by host innate immune receptors and the progress in this field.
Gee, Jason M; Kovach, Michael E; Grippe, Vanessa K; Hagius, Sue; Walker, Joel V; Elzer, Philip H; Roop, R Martin
An isogenic katE mutant derived from virulent Brucella melitensis 16M displays hypersensitivity to hydrogen peroxide in disk sensitivity assays but retains the capacity to colonize pregnant goats and induce abortion. These experimental findings indicate that although the sole periplasmic catalase of Brucella melitensis functions as an antioxidant, this enzyme does not play a critical role in virulence in the natural host.
Ren, Hang; Yang, Mingjuan; Zhang, Guoxia; Liu, Shiwei; Wang, Xinhui; Ke, Yuehua; Du, Xinying; Wang, Zhoujia; Huang, Liuyu; Liu, Chao; Chen, Zeliang
A rapid and sensitive recombinase polymerase amplification (RPA) assay, Bruce-RPA, was developed for detection of Brucella. The assay could detect as few as 3 copies of Brucella per reaction within 20 min. Bruce-RPA represents a candidate point-of-care diagnosis assay for human brucellosis.
Li, Tiefeng; Yuan, Xitong; Ding, Jiabo; Zhen, Qing; Ke, Yuehua; Wang, Yufei; Huang, Liuyu; Mao, Kairong; Chen, Zeliang; Wang, Dali
Brucella melitensis is the most common Brucella species causing human brucellosis. B. melitensis is divided into 3 biovars. Here, we report the complete genome sequence of B. melitensis strain 128, a strain of biovar 3 of sequence type 8, which is prevalent in China.
de Figueiredo, Paul; Ficht, Thomas A; Rice-Ficht, Allison; Rossetti, Carlos A; Adams, L Garry
This review of Brucella-host interactions and immunobiology discusses recent discoveries as the basis for pathogenesis-informed rationales to prevent or treat brucellosis. Brucella spp., as animal pathogens, cause human brucellosis, a zoonosis that results in worldwide economic losses, human morbidity, and poverty. Although Brucella spp. infect humans as an incidental host, 500,000 new human infections occur annually, and no patient-friendly treatments or approved human vaccines are reported. Brucellae display strong tissue tropism for lymphoreticular and reproductive systems with an intracellular lifestyle that limits exposure to innate and adaptive immune responses, sequesters the organism from the effects of antibiotics, and drives clinical disease manifestations and pathology. Stealthy brucellae exploit strategies to establish infection, including i) evasion of intracellular destruction by restricting fusion of type IV secretion system-dependent Brucella-containing vacuoles with lysosomal compartments, ii) inhibition of apoptosis of infected mononuclear cells, and iii) prevention of dendritic cell maturation, antigen presentation, and activation of naive T cells, pathogenesis lessons that may be informative for other intracellular pathogens. Data sets of next-generation sequences of Brucella and host time-series global expression fused with proteomics and metabolomics data from in vitro and in vivo experiments now inform interactive cellular pathways and gene regulatory networks enabling full-scale systems biology analysis. The newly identified effector proteins of Brucella may represent targets for improved, safer brucellosis vaccines and therapeutics.
Yang, Xiaowen; Li, Yajie; Zang, Juan; Li, Yexia; Bie, Pengfei; Lu, Yanli; Wu, Qingmin
Brucella spp. are facultative intracellular pathogens, that cause a contagious zoonotic disease, that can result in such outcomes as abortion or sterility in susceptible animal hosts and grave, debilitating illness in humans. For deciphering the survival mechanism of Brucella spp. in vivo, 42 Brucella complete genomes from NCBI were analyzed for the pan-genome and core genome by identification of their composition and function of Brucella genomes. The results showed that the total 132,143 protein-coding genes in these genomes were divided into 5369 clusters. Among these, 1710 clusters were associated with the core genome, 1182 clusters with strain-specific genes and 2477 clusters with dispensable genomes. COG analysis indicated that 44 % of the core genes were devoted to metabolism, which were mainly responsible for energy production and conversion (COG category C), and amino acid transport and metabolism (COG category E). Meanwhile, approximately 35 % of the core genes were in positive selection. In addition, 1252 potential essential genes were predicted in the core genome by comparison with a prokaryote database of essential genes. The results suggested that the core genes in Brucella genomes are relatively conservation, and the energy and amino acid metabolism play a more important role in the process of growth and reproduction in Brucella spp. This study might help us to better understand the mechanisms of Brucella persistent infection and provide some clues for further exploring the gene modules of the intracellular survival in Brucella spp.
Hatten, Betty A.; Sulkin, S. Edward
Hatten, Betty A. (The University of Texas Southwestern Medical School, Dallas), and S. Edward Sulkin. Intracellular production of Brucella L forms. II. Induction and survival of Brucella abortus L forms in tissue culture. J. Bacteriol. 91:14–20. 1966.—Intracellular survival of altered brucellae, possibly L forms, was not greatly affected by penicillin or streptomycin in concentrations ranging from 5.0 to 40 μg/ml, but a combination of these two antibiotics (2.5 to 20 μg/ml each) reduced the number of positive L-form cultures. Tetracycline (2.0 μg/ml) decreased the number of positive L-form cultures at about the same rate as combinations of the higher concentrations of penicillin and streptomycin. Various concentrations of tetracycline (0.1 to 2.0 μg/ml) with 5.0 μg/ml of penicillin or streptomycin significantly reduced the number of positive L-form cultures. L forms were recovered for several days after elimination of bacteria from the cultures by all of the antibiotics tested. L-form production was not dependent upon the presence of antibiotics in the culture medium, but they were recovered in greater numbers when bacteria were still present in the hamster kidney cells. Addition of thallium acetate to infected cells (at varying intervals of time after infection) to control bacterial growth and conversion to the L phase during cellular disintegration decreased the number of positive L-form cultures obtained over a 10-day period. Comparison of the antibiotic sensitivity of bacteria recovered from infected tissue culture cells with the stock strain of Brucella abortus indicated that some resistance to penicillin and tetracycline had developed. A marked resistance to streptomycin was observed in those bacteria recovered from cells maintained in the presence of this antibiotic. PMID:4955246
Wanninger, Sabrina; Donati, Manuela; Di Francesco, Antonietta; Hässig, Michael; Hoffmann, Karolin; Seth-Smith, Helena M. B.; Marti, Hanna; Borel, Nicole
In pigs, Chlamydia suis has been associated with respiratory disease, diarrhea and conjunctivitis, but there is a high rate of inapparent C. suis infection found in the gastrointestinal tract of pigs. Tetracycline resistance in C. suis has been described in the USA, Italy, Switzerland, Belgium, Cyprus and Israel. Tetracyclines are commonly used in pig production due to their broad-spectrum activity and relatively low cost. The aim of this study was to isolate clinical C. suis samples in cell culture and to evaluate their antibiotic susceptibility in vitro under consideration of antibiotic treatment on herd level. Swab samples (n = 158) identified as C. suis originating from 24 farms were further processed for isolation, which was successful in 71% of attempts with a significantly higher success rate from fecal swabs compared to conjunctival swabs. The farms were divided into three treatment groups: A) farms without antibiotic treatment, B) farms with prophylactic oral antibiotic treatment of the whole herd consisting of trimethoprime, sulfadimidin and sulfathiazole (TSS), or C) farms giving herd treatment with chlortetracycline with or without tylosin and sulfadimidin (CTS). 59 isolates and their corresponding clinical samples were selected and tested for the presence or absence of the tetracycline resistance class C gene [tet(C)] by conventional PCR and isolates were further investigated for their antibiotic susceptibility in vitro. The phenotype of the investigated isolates was either classified as tetracycline sensitive (Minimum inhibitory concentration [MIC] < 2 μg/ml), intermediate (2 μg/ml ≤ MIC < 4 μg/ml) or resistant (MIC ≥ 4 μg/ml). Results of groups and individual pigs were correlated with antibiotic treatment and time of sampling (beginning/end of the fattening period). We found clear evidence for selective pressure as absence of antibiotics led to isolation of only tetracycline sensitive or intermediate strains whereas tetracycline treatment
Wanninger, Sabrina; Donati, Manuela; Di Francesco, Antonietta; Hässig, Michael; Hoffmann, Karolin; Seth-Smith, Helena M B; Marti, Hanna; Borel, Nicole
In pigs, Chlamydia suis has been associated with respiratory disease, diarrhea and conjunctivitis, but there is a high rate of inapparent C. suis infection found in the gastrointestinal tract of pigs. Tetracycline resistance in C. suis has been described in the USA, Italy, Switzerland, Belgium, Cyprus and Israel. Tetracyclines are commonly used in pig production due to their broad-spectrum activity and relatively low cost. The aim of this study was to isolate clinical C. suis samples in cell culture and to evaluate their antibiotic susceptibility in vitro under consideration of antibiotic treatment on herd level. Swab samples (n = 158) identified as C. suis originating from 24 farms were further processed for isolation, which was successful in 71% of attempts with a significantly higher success rate from fecal swabs compared to conjunctival swabs. The farms were divided into three treatment groups: A) farms without antibiotic treatment, B) farms with prophylactic oral antibiotic treatment of the whole herd consisting of trimethoprime, sulfadimidin and sulfathiazole (TSS), or C) farms giving herd treatment with chlortetracycline with or without tylosin and sulfadimidin (CTS). 59 isolates and their corresponding clinical samples were selected and tested for the presence or absence of the tetracycline resistance class C gene [tet(C)] by conventional PCR and isolates were further investigated for their antibiotic susceptibility in vitro. The phenotype of the investigated isolates was either classified as tetracycline sensitive (Minimum inhibitory concentration [MIC] < 2 μg/ml), intermediate (2 μg/ml ≤ MIC < 4 μg/ml) or resistant (MIC ≥ 4 μg/ml). Results of groups and individual pigs were correlated with antibiotic treatment and time of sampling (beginning/end of the fattening period). We found clear evidence for selective pressure as absence of antibiotics led to isolation of only tetracycline sensitive or intermediate strains whereas tetracycline treatment
Pregnant mice inoculated i.p. or i.v. with virulent Brucella abortus Strain 544 displayed strong infection, evidenced by brucella enumeration in placentas and dams' spleens. Vaccination 1 month before pregnancy decreased frequency of placental colonization and number of brucella per infected placenta and per spleen. Protein-bound cell wall peptidoglycan (PG) fractions extracted from brucella protected mice as well as H38 killed and B19 attenuated living vaccines. The lipopolysaccharide (LPS) fraction was comparatively less active. Immune serum injected i.v., either 24 h before or just after i.v. challenge of 15-day pregnant mice effectively transferred resistance to placental colonization. Anti LPS, anti PG and anti killed brucella sera protected mice as well as vaccination one month before pregnancy. The immunity transferred persisted for at least 3 days. PMID:6419766
Comerci, Diego J.; Pollevick, Guido D.; Vigliocco, Ana M.; Frasch, Alberto C. C.; Ugalde, Rodolfo A.
A vector for the expression of foreign antigens in the vaccine strain Brucella abortus S19 was developed by using a DNA fragment containing the regulatory sequences and the signal peptide of the Brucella bcsp31 gene. This fragment was cloned in broad-host-range plasmid pBBR4MCS, resulting in plasmid pBEV. As a reporter protein, a repetitive antigen of Trypanosoma cruzi was used. The recombinant fusion protein is stably expressed and secreted into the Brucella periplasmic space, inducing a good antibody response against the T. cruzi antigen. The expression of the repetitive antigen in Brucella neither altered its growth pattern nor generated a toxic or lethal effect during experimental infection. The application of this strategy for the generation of live recombinant vaccines and the tagging of B. abortus S19 vaccine is discussed. This is the first time that a recombinant protein has been expressed in the periplasm of brucellae. PMID:9673273
Corbel, M. J.; Scott, A. C.; Ross, H. M.
The properties of an atypical Brucella strain isolated from lymph node tissue of a cow slaughtered as a brucellosis reactor were examined. The organism was Gram negative and highly pleomorphic, existing as cocci, coccobacilli, rods, branched and irregular forms which stained with fluorescent antibody conjugates prepared against rough and smooth Brucella abortus strains. It produced lecithinase and required at least 15% v/v equine or bovine serum for growth. It did not need supplementary CO2 for growth, produced H2S and was inhibited by brucella dyes and partially by i-erythritol. Growth inhibition or lysis was produced by brucella-phages. The organism was not pathogenic for guinea-pigs or mice but evoked antibodies mainly to rough Brucella antigens. Images Fig. 1 Fig. 2 Fig. 3 Fig. 1 Fig. 2 Fig. 1 Fig. 1 Fig. 2 PMID:6820027
Ilhan, Fatma; Yener, Zabit
Brucella melitensis, a worldwide zoonotic pathogen, is a significant cause of abortion in sheep and goats in some countries. The present study was carried out to determine, by immunohistochemistry, the presence of B. melitensis antigens in 110 naturally occurring aborted sheep fetuses. Sections of lung, liver, kidney, and spleen of each fetus were stained with immunoperoxidase to detect Brucella antigens. Brucella melitensis antigens were detected in 33 of 110 fetuses (30%). In the 33 positive cases, Brucella antigens were found in lung (25 [22.7%]), liver (21 [19%]), spleen (13 [11.8%]), and kidney (6 [5.4%]). Microscopic studies demonstrated that Brucella antigens were mainly located in the cytoplasm of macrophages and neutrophils of the lung, and in the cytoplasm of macrophages in the portal infiltrates and Kupffer cells of the liver. It was concluded that immunohistochemistry in formalin-fixed, paraffin-embedded tissues is a useful tool for the diagnosis of spontaneous ovine abortion caused by B. melitensis.
Çiftci, Alper; İça, Tuba; Savaşan, Serap; Sareyyüpoğlu, Barış; Akan, Mehmet; Diker, Kadir Serdar
The genus Brucella causes significant economic losses due to infertility, abortion, stillbirth or weak calves, and neonatal mortality in livestock. Brucellosis is still a zoonosis of public health importance worldwide. The study was aimed to optimize and evaluate PCR assays used for the diagnosis of Brucella infections. For this aim, several primers and PCR protocols were performed and compared with Brucella cultures and biological material inoculated with Brucella. In PCR assays, genus- or species-specific oligonucleotide primers derived from 16S rRNA sequences (F4/R2, Ba148/928, IS711, BruP6-P7) and OMPs (JPF/JPR, 31ter/sd) of Brucella were used. All primers except for BruP6-P7 detected the DNA from reference Brucella strains and field isolates. In spiked blood, milk, and semen samples, F4-R2 primer-oriented PCR assays detected minimal numbers of Brucella. In spiked serum and fetal stomach content, Ba148/928 primer-oriented PCR assays detected minimal numbers of Brucella. Field samples collected from sheep and cattle were examined by bacteriological methods and optimized PCR assays. Overall, sensitivity of PCR assays was found superior to conventional bacteriological isolation. Brucella DNA was detected in 35.1, 1.1, 24.8, 5.0, and 8.0% of aborted fetus, blood, milk, semen, and serum samples by PCR assays, respectively. In conclusion, PCR assay in optimized conditions was found to be valuable in sensitive and specific detection of Brucella infections of animals.
Martínez de Tejada, G; Pizarro-Cerdá, J; Moreno, E; Moriyón, I
The actions of polymyxin B, rabbit polymorphonuclear lysosome extracts, 14 polycationic peptides (including defensin NP-2, cecropin P1, lactoferricin B, and active peptides from cationic protein 18 and bactenecin), EDTA, and Tris on Brucella spp. were studied, with other gram-negative bacteria as controls. Brucella spp. were comparatively resistant to all of the agents listed above and bound less polymyxin B, and their outer membranes (OMs) were neither morphologically altered nor permeabilized to lysozyme by polymyxin B concentrations, although both effects were observed for controls. EDTA and peptides increased or accelerated the partition of the hydrophobic probe N-phenyl-naphthylamine into Escherichia coli and Haemophilus influenzae OMs but had no effect on Brucella OMs. Since Brucella and H. influenzae OMs are permeable to hydrophobic compounds (G. Martínez de Tejada and I. Moriyón, J. Bacteriol. 175:5273-5275, 1993), the results show that such unusual permeability is not necessarily related to resistance to polycations. Although rough (R) B. abortus and B. ovis were more resistant than the controls were, there were qualitative and quantitative differences with smooth (S) brucellae; this may explain known host range and virulence differences. Brucella S-lipopolysaccharides (LPSs) had reduced affinities for polycations, and insertion of Brucella and Salmonella montevideo S-LPSs into the OM of a Brucella R-LPS mutant increased and decreased, respectively, its resistance to cationic peptides. The results show that the core lipid A of Brucella LPS plays a major role in polycation resistance and that O-chain density also contributes significantly. It is proposed that the features described above contribute to Brucella resistance to the oxygen-independent systems of phagocytes. PMID:7622230
Koia, Jonni; Moyle, Richard; Hendry, Caroline; Lim, Lionel; Botella, José Ramón
The availability of a variety of promoter sequences is necessary for the genetic engineering of plants, in basic research studies and for the development of transgenic crops. In this study, the promoter and 5' untranslated regions of the evolutionally conserved protein translation factor SUI1 gene and ribosomal protein L36 gene were isolated from pineapple and sequenced. Each promoter was translationally fused to the GUS reporter gene and transformed into the heterologous plant system Arabidopsis thaliana. Both the pineapple SUI1 and L36 promoters drove GUS expression in all tissues of Arabidopsis at levels comparable to the CaMV35S promoter. Transient assays determined that the pineapple SUI1 promoter also drove GUS expression in a variety of climacteric and non-climacteric fruit species. Thus the pineapple SUI1 and L36 promoters demonstrate the potential for using translation factor and ribosomal protein genes as a source of promoter sequences that can drive constitutive transgene expression patterns.
Maneerat, K; Yongkiettrakul, S; Kramomtong, I; Tongtawe, P; Tapchaisri, P; Luangsuk, P; Chaicumpa, W; Gottschalk, M; Srimanote, P
Isolates of Streptococcus suis from different Western countries as well as those from China and Vietnam have been previously well characterized. So far, the genetic characteristics and relationship between S. suis strains isolated from both humans and pigs in Thailand are unknown. In this study, a total of 245 S. suis isolates were collected from both human cases (epidemic and sporadic) and pigs (diseased and asymptomatic) in Thailand. Bacterial strains were identified by biochemical tests and PCR targeting both, the 16S rRNA and gdh genes. Thirty-six isolates were identified as serotype 2 based on serotyping and the cps2-PCR. These isolates were tested for the presence of six virulence-associated genes: an arginine deiminase (arcA), a 38-kDa protein and protective antigen (bay046), an extracellular factor (epf), an hyaluronidase (hyl), a muramidase-released protein (mrp) and a suilysin (sly). In addition, the genetic diversities of these isolates were studied by RAPD PCR and multilocus sequence typing (MLST) analysis. Four virulence-associated gene patterns (VAGP 1 to 4) were obtained, and the majority of isolates (32/36) carried all genes tested (VAGP1). Each of the three OPB primers used provided 4 patterns designated RAPD-A to RAPD-D. Furthermore, MLST analysis could also distinguish the 36 isolates into four sequence types (STs): ST1 (n = 32), ST104 (n = 2), ST233 (n = 1) and a newly identified ST, ST336 (n = 1). Dendrogram constructions based on RAPD patterns indicated that S. suis serotype 2 isolates from Thailand could be divided into four groups and that the characteristics of the individual groups were in complete agreement with the virulence gene profiles and STs. The majority (32/36) of isolates recovered from diseased pigs, slaughterhouse pigs or human patients could be classified into a single group (VAGP1, RAPD-A and ST1). This genetic information strongly suggests the transmission of S. suis isolates from pigs to humans in Thailand. Our findings are
Nutravong, Thitima; Angkititrakul, Sunpetch; Jiwakanon, Netchanok; Wongchanthong, Wanlaya; Dejsirilerts, Surang; Nawa, Yukifumi
Streptococcus suis serotype 2 infections occur in many provinces of north-eastern Thailand, knowledge concerning the prevalence of the common S. suis serotypes (1, 1/2, 2, 5, 7, 8, 9, 14 and 16) among healthy and diseased pigs in upper northeastern Thailand remains limited. This study investigated S. suis isolates from pigs (healthy and diseased) and also from humans using 11 conventional biochemical tests, 16S rDNA PCR and sequence analysis and multiplex PCR genotyping of porcine cps and gdh. Thirty-three isolates were obtained between 2009 and 2012 from blood or cerebrospinal fluid of patients from northeastern Thailand previously diagnosed with S. suis infection, based on clinical symptoms and laboratory diagnosis using 11 biochemical tests and PCR detection of 16S rDNA and cps. Eleven S. suis isolates were obtained between 2006 and 2009 from diseased pigs with clinical signs and laboratory diagnoses. In addition, 43 isolates obtained from 741 nasal swab cultures of slaughtered pigs between 2011 and 2012 were included. All three methods showed similar sensitivity in detection of S. suis from clinical and diseased pig specimens, although in healthy pigs, the 11 conventional biochemical methods yielded 2.3% false positives, and the gdh PCR detection method exhibited 31% false negatives. S. suis was present among healthy pigs in 8 of 10 provinces in upper northeastern Thailand, giving an average prevalence of 5.7% (range 1%-17%) using conventional methods together with 16S rDNA PCR assay. False positives by conventional methods were due to species with similar phenotypes, such as viridian streptococci, and are not statistically different from those obtained with the 16S rDNA PCR method, and the false negatives using gdh PCR assay will require further investigation. As S. suis was recovered from both diseased and healthy pigs, raw or undercooked pork products should be considered unsafe for handling or consumption in these regions of Thailand.
Sokoli, Albina; Groebel, Katrin; Hoelzle, Katharina; Amselgruber, Werner M; Mateos, José M; Schneider, Mårten K J; Ziegler, Urs; Felder, Kathrin M; Hoelzle, Ludwig E
Hemotrophic mycoplasmas (HM) are highly specialized red blood cell parasites that cause infectious anemia in a variety of mammals, including humans. To date, no in vitro cultivation systems for HM have been available, resulting in relatively little information about the pathogenesis of HM infection. In pigs, Mycoplasma suis-induced infectious anemia is associated with hemorrhagic diathesis, and coagulation dysfunction. However, intravasal coagulation and subsequent consumption coagulopathy can only partly explain the sequence of events leading to hemorrhagic diathesis manifesting as cyanosis, petechial bleeding, and ecchymosis, and to disseminated coagulation. The involvement of endothelial activation and damage in M. suis-associated pathogenesis was investigated using light and electron microscopy, immunohistochemistry, and cell sorting. M. suis interacted directly with endothelial cells in vitro and in vivo. Endothelial activation, widespread endothelial damage, and adherence of red blood cells to the endothelium were evident in M. suis-infected pigs. These alterations of the endothelium were accompanied by hemorrhage, intravascular coagulation, vascular occlusion, and massive morphological changes within the parenchyma. M. suis biofilm-like microcolonies formed on the surface of endothelial cells, and may represent a putative persistence mechanism of M. suis. In vitro analysis demonstrated that M. suis interacted with the endothelial cytoskeletal protein actin, and induced actin condensation and activation of endothelial cells, as determined by the up-regulation of ICAM, PECAM, E-selectin, and P-selectin. These findings demonstrate an additional cell tropism of HM for endothelial cells and suggest that M. suis interferes with the protective function of the endothelium, resulting in hemorrhagic diathesis.
Su, Yong; Yao, Wen; Perez-Gutierrez, Odette N; Smidt, Hauke; Zhu, Wei-Yun
This present study investigated the changes in bacterial community composition, with an emphasis on Lactobacillus spp. and Streptococcus suis populations as potentially beneficial and harmful groups, in the stomach, jejunum and ileum of piglets after weaning (21 days postpartum) by 16S rRNA gene-based methods. Denaturing gradient gel electrophoresis analysis showed that, after weaning, predominant bands related to Lactobacillus spp. disappeared and were replaced by potential pathogenic species, such as Peptostreptococcus anaerobius, Moraxella cuniculi, S. suis and Porphyromonas catoniae. Real-time PCR revealed that the abundances of lactobacilli and Lactobacillus sobrius as a proportion of total bacterial abundance were significantly lower in the stomach, jejunum and ileum of weaned piglets than in 21-day-old piglets. A specific and sensitive real-time PCR assay was developed for quantification of the important pathogen S. suis within gastrointestinal microbiota. The assay showed that S. suis predominated in the stomach samples of weaned piglets with population levels up to 10(7) copies g(-1) digesta, while it was not detected in the stomach before weaning. Streptococcus suis was not dominant in the jejunum and ileum digesta before weaning, but became dominant after weaning, with population levels up to 10(7) copies g(-1) digesta. The results demonstrated for the first time the postweaning dominance of the potentially harmful S. suis in piglet intestine. The results also suggest that the defensive barrier of the stomach can be impaired as S. suis became dominant while the proportion of Lactobacillus populations decreased after weaning, which may further result in an increase of S. suis abundance in the intestine.
Vela, Ana I.; Goyache, Joaquin; Tarradas, Carmen; Luque, Inmaculada; Mateos, Ana; Moreno, Miguel A.; Borge, Carmen; Perea, J. Anselmo; Domínguez, Lucas; Fernández-Garayzábal, José F.
Pulsed-field gel electrophoresis (PFGE) was used to investigate the diversity of Streptococcus suis isolates of various serotypes recovered from swine clinical samples in Spain. Capsular types 9 (64.9%) and 2 (14.8%) were the most frequently isolated serotypes followed by serotype 7 (5.9%) and serotype 8 (4.3%). The PFGE results of this study with 60 different pulsotypes indicate a great genetic diversity among the S. suis isolates, which is consistent with the broad distribution of S. suis in the swine population. Forty-five percent of the pulsotypes corresponded to single isolates, no pulsotype was common to all farms, and at least 3 different pulsotypes were isolated in 56% of herds in which more than 3 clinical isolates were analyzed. These results reveal a great diversity both between and within herds throughout the strains of S. suis studied, demonstrating that different strains of S. suis are associated with infection in pigs. Some pulsotypes were more frequently isolated and exhibited a wider distribution over herds than others, and were the unique or predominant strains in several herds, suggesting the existence of a prevalent or a few prevalent clones responsible for a large proportion of clinical cases. Overall, the great genetic heterogeneity of the clinical strains of S. suis, the isolation of different strains within the same herd, and the predominance of particular strains in some herds are evidence that infection by S. suis is a dynamic process and reinforce the idea that the epidemiology of S. suis infection is very complex. PMID:12791872
Vela, Ana I; Goyache, Joaquin; Tarradas, Carmen; Luque, Inmaculada; Mateos, Ana; Moreno, Miguel A; Borge, Carmen; Perea, J Anselmo; Domínguez, Lucas; Fernández-Garayzábal, José F
Pulsed-field gel electrophoresis (PFGE) was used to investigate the diversity of Streptococcus suis isolates of various serotypes recovered from swine clinical samples in Spain. Capsular types 9 (64.9%) and 2 (14.8%) were the most frequently isolated serotypes followed by serotype 7 (5.9%) and serotype 8 (4.3%). The PFGE results of this study with 60 different pulsotypes indicate a great genetic diversity among the S. suis isolates, which is consistent with the broad distribution of S. suis in the swine population. Forty-five percent of the pulsotypes corresponded to single isolates, no pulsotype was common to all farms, and at least 3 different pulsotypes were isolated in 56% of herds in which more than 3 clinical isolates were analyzed. These results reveal a great diversity both between and within herds throughout the strains of S. suis studied, demonstrating that different strains of S. suis are associated with infection in pigs. Some pulsotypes were more frequently isolated and exhibited a wider distribution over herds than others, and were the unique or predominant strains in several herds, suggesting the existence of a prevalent or a few prevalent clones responsible for a large proportion of clinical cases. Overall, the great genetic heterogeneity of the clinical strains of S. suis, the isolation of different strains within the same herd, and the predominance of particular strains in some herds are evidence that infection by S. suis is a dynamic process and reinforce the idea that the epidemiology of S. suis infection is very complex.
Zhang, Anding; Wu, Jiayan; Chen, Bo; Hua, Yafeng; Yu, Jun; Chen, Huanchun; Xiao, Jingfa; Jin, Meilin
Background Streptococcus suis infections are a serious problem for both humans and pigs worldwide. The emergence and increasing prevalence of antibiotic-resistant S. suis strains pose significant clinical and societal challenges. Results In our study, we sequenced one multi-drug-resistant S. suis strain, R61, and one S. suis strain, A7, which is fully sensitive to all tested antibiotics. Comparative genomic analysis revealed that the R61 strain is phylogenetically distinct from other S. suis strains, and the genome of R61 exhibits extreme levels of evolutionary plasticity with high levels of gene gain and loss. Our results indicate that the multi-drug-resistant strain R61 has evolved three main categories of resistance. Conclusions Comparative genomic analysis of S. suis strains with diverse drug-resistant phenotypes provided evidence that horizontal gene transfer is an important evolutionary force in shaping the genome of multi-drug-resistant strain R61. In this study, we discovered novel and previously unexamined mutations that are strong candidates for conferring drug resistance. We believe that these mutations will provide crucial clues for designing new drugs against this pathogen. In addition, our work provides a clear demonstration that the use of drugs has driven the emergence of the multi-drug-resistant strain R61. PMID:21966396
Chen, Shouyi; Li, Xunde; Li, Juntao; Atwill, Edward R
Brucella spp. are facultative intracellular bacteria that cause zoonotic disease of brucellosis worldwide. Livestock that are most vulnerable to brucellosis include cattle, goats, and pigs. Brucella spp. cause serious health problems to humans and animals and economic losses to the livestock industry. Traditional methods for detection of Brucella spp. take 48-72 h (Kumar et al., J Commun Dis 29:131-137, 1997; Barrouin-Melo et al., Res Vet Sci 83:340-346, 2007) that do not meet the food industry's need of rapid detection. Therefore, there is an urgent need of fast, specific, sensitive, and inexpensive method for diagnosing of Brucella spp. Loop-mediated isothermal amplification (LAMP) is a method to amplify nucleic acid at constant temperatures. Amplification can be detected by visual detection, fluorescent stain, turbidity, and electrophoresis. We targeted at the Brucella-specific gene omp25 and designed LAMP primers for detection of Brucella spp. Amplification of DNA with Bst DNA polymerase can be completed at 65 °C in 60 min. Amplified products can be detected by SYBR Green I stain and 2.0% agarose gel electrophoresis. The LAMP method is feasible for detection of Brucella spp. from blood and milk samples.
Moulana, Zahra; Roushan, Mohammad Reza Hasanjani; Marashi, Seyed Mahmoud Amin
Introduction Brucellosis is a worldwide zoonosis and a significant cause of loss of health in humans and animals. Traditionally, classic diagnosis is carried out by isolation of Brucella, which is time-consuming, technically challenging and potentially dangerous. The aim of this study was to expand a molecular test that would be used for the develop detection of Brucella in a single reaction with high sensitivity and specificity, by targeting IS711element. Methods This study was carried out from 2015 to 2016 at the Ayatolla Rohani hospital in Babol, Iran. The present study was designed to develop PCR assay, based on IS711 gene for rapid diagnosis of Brucella spp. and immediate detection of Brucella, with high sensitivity and specificity. Four pairs of oligo-nucleotide primers with sizes of 547, 403, 291 and 127bp respectively, were planned to exclusively amplify the targeted genes of Brucella species. Results Our results show that, five PCR primers set up, would be helpful in amplifying the DNAs from the genus Brucella with high specificity and sensitivity so it can be 12 fg, for Brucella species to provide a valuable tool for diagnosis. Conclusion This method can be more useful than serological and biochemical tests and in addition, this reduces the number of required tests more rapidly and economically. PMID:28070255
Roset, Mara S; García Fernández, Lucía; DelVecchio, Vito G; Briones, Gabriel
Brucella is an intracellular bacterial pathogen that causes the worldwide zoonotic disease brucellosis. Brucella virulence relies on its ability to transition to an intracellular lifestyle within host cells. Thus, this pathogen must sense its intracellular localization and then reprogram gene expression for survival within the host cell. A comparative proteomic investigation was performed to identify differentially expressed proteins potentially relevant for Brucella intracellular adaptation. Two proteins identified as cyclophilins (CypA and CypB) were overexpressed in the intracellular environment of the host cell in comparison to laboratory-grown Brucella. To define the potential role of cyclophilins in Brucella virulence, a double-deletion mutant was constructed and its resulting phenotype was characterized. The Brucella abortus ΔcypAB mutant displayed increased sensitivity to environmental stressors, such as oxidative stress, pH, and detergents. In addition, the B. abortus ΔcypAB mutant strain had a reduced growth rate at lower temperature, a phenotype associated with defective expression of cyclophilins in other microorganisms. The B. abortus ΔcypAB mutant also displays reduced virulence in BALB/c mice and defective intracellular survival in HeLa cells. These findings suggest that cyclophilins are important for Brucella virulence and survival in the host cells.
Wei, Pan; Lu, Qiang; Cui, Guimei; Guan, Zhenhong; Yang, Li; Sun, Changjiang; Sun, Wanchun; Peng, Qisheng
Triggering receptor expressed on myeloid cells-2 (TREM-2) is a cell surface receptor primarily expressed on macrophages and dendritic cells. TREM-2 functions as a phagocytic receptor for bacteria as well as an inhibitor of Toll like receptors (TLR) induced inflammatory cytokines. However, the role of TREM-2 in Brucella intracellular growth remains unknown. To investigate whether TREM-2 is involved in Brucella intracellular survival, we chose bone marrow derived macrophages (BMDMs), in which TREM-2 is stably expressed, as cell model. Colony formation Units (CFUs) assay suggests that TREM-2 is involved in the internalization of Brucella abortus (B. abortus) by macrophages, while silencing of TREM-2 decreases intracellular survival of B. abortus. To further study the underlying mechanisms of TREM-2-mediated bacterial intracellular survival, we examined the activation of B. abortus-infected macrophages through determining the kinetics of activation of the three MAPKs, including ERK, JNK and p38, and measuring TNFα production in response to lipopolysaccharide (LPS) of Brucella (BrLPS) or B. abortus stimulation. Our data show that TREM-2 deficiency promotes activation of Brucella-infected macrophages. Moreover, our data also demonstrate that macrophage activation promotes killing of Brucella by enhancing nitric oxygen (NO), but not reactive oxygen species (ROS) production, macrophage apoptosis or cellular death. Taken together, these findings provide a novel interpretation of Brucella intracellular growth through inhibition of NO production produced by TREM-2-mediated activated macrophages.
Jensen, Silje-Kristin; Nymo, Ingebjørg Helena; Forcada, Jaume; Hall, Ailsa; Godfroid, Jacques
Brucellosis is a worldwide infectious zoonotic disease caused by Gram-negative bacteria of the genus Brucella, and Brucella infections in marine mammals were first reported in 1994. A serosurvey investigating the presence of anti-Brucella antibodies in 3 Antarctic pinniped species was undertaken with a protein A/G indirect enzyme-linked immunosorbent assay (iELISA) and the Rose Bengal test (RBT). Serum samples from 33 Weddell seals Leptonychotes weddelli were analysed, and antibodies were detected in 8 individuals (24.2%) with the iELISA and in 21 (65.6%) with the RBT. We tested 48 southern elephant seal Mirounga leonina sera and detected antibodies in 2 animals (4.7%) with both the iELISA and the RBT. None of the 21 Antarctic fur seals Arctocephalus gazella was found positive. This is the first report of anti-Brucella antibodies in southern elephant seals. The potential impact of Brucella infection in pinnipeds in Antarctica is not known, but Brucella spp. are known to cause abortion in terrestrial species and cetaceans. Our findings suggest that Brucella infection in pinnipeds is present in the Antarctic, but to date B. pinnipedialis has not been isolated from any Antarctic pinniped species, leaving the confirmation of infection pending.
Tian, Mingxing; Qu, Jing; Bao, Yanqing; Gao, Jianpeng; Liu, Jiameng; Wang, Shaohui; Sun, Yingjie; Ding, Chan; Yu, Shengqing
Brucellosis, the most common widespread zoonotic disease, is caused by Brucella spp., which are facultative, intracellular, Gram-negative bacteria. With the development of molecular biology techniques, more and more virulence-associated factors have been identified in Brucella spp. A suitable plasmid system is an important tool to study virulence genes in Brucella. In this study, we constructed three constitutive replication plasmids (pTM1-Cm, pTM2-Amp, and pTM3-Km) using the replication origin (rep) region derived from the pBBR1-MCS vector. Also, a DNA fragment containing multiple cloning sites (MCSs) and a terminator sequence derived from the pCold vector were produced for complementation of the deleted genes. Besides pGH-6×His, a plasmid containing the groE promoter of Brucella spp. was constructed to express exogenous proteins in Brucella with high efficiency. Furthermore, we constructed the inducible expression plasmid pZT-6×His, containing the tetracycline-inducible promoter pzt1, which can induce expression by the addition of tetracycline in the Brucella culture medium. The constructed pTM series plasmids will play an important role in the functional investigation of Brucella spp.
Keriel, Anne; Botella, Eric; Estrach, Soline; Bragagnolo, Gabriel; Vergunst, Annette C; Feral, Chloe C; O'Callaghan, David
Brucella are intracellular bacterial pathogens that use a type IV secretion system (T4SS) to escape host defenses and create a niche in which they can multiply. Although the importance of Brucella T4SS is clear, little is known about its interactions with host cell structures. In this study, we identified the eukaryotic protein CD98hc as a partner for Brucella T4SS subunit VirB2. This transmembrane glycoprotein is involved in amino acid transport, modulation of integrin signaling, and cell-to-cell fusion. Knockdown of CD98hc expression in HeLa cells demonstrated that it is essential for Brucella infection. Using knockout dermal fibroblasts, we confirmed its role for Brucella but found that it is not required for Salmonella infection. CD98hc transiently accumulates around the bacteria during the early phases of infection and is required for both optimal bacterial uptake and intracellular multiplication of Brucella. These results provide new insights into the complex interplay between Brucella and its host.
Giambartolomei, Guillermo H; Arriola Benitez, Paula C; Delpino, M Victoria
Osteoarticular brucellosis is the most common presentation of human active disease although its prevalence varies widely. The three most common forms of osteoarticular involvement are sacroiliitis, spondylitis, and peripheral arthritis. The molecular mechanisms implicated in bone damage have been recently elucidated. B. abortus induces bone damage through diverse mechanisms in which TNF-α and the receptor activator of nuclear factor kappa-B ligand (RANKL)-the natural modulator of bone homeostasis are involved. These processes are driven by inflammatory cells, like monocytes/macrophages, neutrophils, Th17 CD4(+) T, and B cells. In addition, Brucella abortus has a direct effect on osteoarticular cells and tilts homeostatic bone remodeling. These bacteria inhibit bone matrix deposition by osteoblasts (the only bone cells involved in bone deposition), and modify the phenotype of these cells to produce matrix metalloproteinases (MMPs) and cytokine secretion, contributing to bone matrix degradation. B. abortus also affects osteoclasts (cells naturally involved in bone resorption) by inducing an increase in osteoclastogenesis and osteoclast activation; thus, increasing mineral and organic bone matrix resorption, contributing to bone damage. Given that the pathology induced by Brucella species involved joint tissue, experiments conducted on synoviocytes revealed that besides inducing the activation of these cells to secrete chemokines, proinflammatory cytokines and MMPS, the infection also inhibits synoviocyte apoptosis. Brucella is an intracellular bacterium that replicates preferentially in the endoplasmic reticulum of macrophages. The analysis of B. abortus-infected synoviocytes indicated that bacteria also replicate in their reticulum suggesting that they could use this cell type for intracellular replication during the osteoarticular localization of the disease. Finally, the molecular mechanisms of osteoarticular brucellosis discovered recently shed light on how the
Seabury, C.M.; Halbert, N.D.; Gogan, P.J.P.; Templeton, J.W.; Derr, J.N.
The implication that host cellular prion protein (PrPC) may function as a cell surface receptor and/or portal protein for Brucella abortus in mice prompted an evaluation of nucleotide and amino acid variation within exon 3 of the prion protein gene (PRNP) for six US bison populations. A non-synonymous single nucleotide polymorphism (T50C), resulting in the predicted amino acid replacement M17T (Met ??? Thr), was identified in each population. To date, no variation (T50: Met) has been detected at the corresponding exon 3 nucleotide and/or amino acid position for domestic cattle. Notably, 80% (20 of 25) of the Yellowstone National Park bison possessing the C/C genotype were Brucella spp. seropositive, representing a significant (P = 0.021) association between seropositivity and the C/C genotypic class. Moreover, significant differences in the distribution of PRNP exon 3 alleles and genotypes were detected between Yellowstone National Park bison and three bison populations that were either founded from seronegative stock or previously subjected to test-and-slaughter management to eradicate brucellosis. Unlike domestic cattle, no indel polymorphisms were detected within the corresponding regions of the putative bison PRNP promoter, intron 1, octapeptide repeat region or 3???-untranslated region for any population examined. This study provides the first evidence of a potential association between nucleotide variation within PRNP exon 3 and the presence of Brucella spp. antibodies in bison, implicating PrPC in the natural resistance of bison to brucellosis infection. ?? 2005 International Society for Animal Genetics.
Giambartolomei, Guillermo H.; Arriola Benitez, Paula C.; Delpino, M. Victoria
Osteoarticular brucellosis is the most common presentation of human active disease although its prevalence varies widely. The three most common forms of osteoarticular involvement are sacroiliitis, spondylitis, and peripheral arthritis. The molecular mechanisms implicated in bone damage have been recently elucidated. B. abortus induces bone damage through diverse mechanisms in which TNF-α and the receptor activator of nuclear factor kappa-B ligand (RANKL)-the natural modulator of bone homeostasis are involved. These processes are driven by inflammatory cells, like monocytes/macrophages, neutrophils, Th17 CD4+ T, and B cells. In addition, Brucella abortus has a direct effect on osteoarticular cells and tilts homeostatic bone remodeling. These bacteria inhibit bone matrix deposition by osteoblasts (the only bone cells involved in bone deposition), and modify the phenotype of these cells to produce matrix metalloproteinases (MMPs) and cytokine secretion, contributing to bone matrix degradation. B. abortus also affects osteoclasts (cells naturally involved in bone resorption) by inducing an increase in osteoclastogenesis and osteoclast activation; thus, increasing mineral and organic bone matrix resorption, contributing to bone damage. Given that the pathology induced by Brucella species involved joint tissue, experiments conducted on synoviocytes revealed that besides inducing the activation of these cells to secrete chemokines, proinflammatory cytokines and MMPS, the infection also inhibits synoviocyte apoptosis. Brucella is an intracellular bacterium that replicates preferentially in the endoplasmic reticulum of macrophages. The analysis of B. abortus-infected synoviocytes indicated that bacteria also replicate in their reticulum suggesting that they could use this cell type for intracellular replication during the osteoarticular localization of the disease. Finally, the molecular mechanisms of osteoarticular brucellosis discovered recently shed light on how the
Tang, Fang; Zhang, Wei; Lu, Chengping
Streptococcus suis (S. suis) infection is considered to be a major problem in the swine industry worldwide. Based on the capsular type, 33 serotypes of S. suis have been described, with serotype 2 (SS2) being the most frequently isolated from diseased piglets. Little is known, however, about the pathogenesis and virulence factors of S. suis. Research on bacteriophages highlights a new area in S. suis research. A S. suis serotype 2 bacteriophage, designated SMP, has been previously isolated in our laboratory. Here, we selected a lysogenic isolate in which the SMP phage was integrated into the chromosome of strain SS2-4. Compared to the wild-type isolate, the lysogenic strain showed increased mortality in zebra fish. Moreover the sensitivity of the lysogenic strain to lysozyme was seven times higher than that of the wild-type. PMID:23326601
Viadas, C; Rodríguez, M C; García-Lobo, J M; Sangari, F J; López-Goñi, I
The genus Brucella contains bacteria producing a zoonosis of large sanitary and economical impact. The complete nucleotide sequence of eight Brucella isolates is currently available. This information can be used for high throughput approaches to the biology of this genus such as the construction of comprehensive collections of ORF clones or ORFeomes. The ORFeome of Brucella melitensis was a first contribution to this goal. Using the Brucella ORFeome as starting material we have amplified each ORF and printed them in duplicate onto coated glass slides along with the appropriate positive and negative controls. Quality control of the microarray was performed by image analysis after ethidium bromide staining. This Brucella DNA microarray was used to determine the global transcriptional profile of Brucella abortus grown under laboratory conditions. Two sets of genes representing strongly and poorly expressed genes have been defined. The occurrence of several genes of the same operon in the same data set has been taken as additional proof of the significance of the results. The two sets have been validated by RT-PCR of retrotranscribed RNA. Among the more abundant transcripts we found ribosomal proteins, Krebs cycle and oxidative phosphorylation enzymes. virB, flagellar components and other genes related with virulence and intracellular growth were in the poorly transcribed set. This report demonstrated the usefulness of the ORFeome for the construction of a PCR product microarray for the analysis of global gene expression in Brucella and also applicable to other microorganisms. The results provided here represent a comprehensive description of the global transcriptional profile of B. abortus grown under laboratory conditions and, at the same time, validate the use of this Brucella microarray for the study of the biology and pathogenesis of Brucella through the analysis of gene expression under any experimental conditions.
Smith, Judith A.; Khan, Mike; Magnani, Diogo D.; Harms, Jerome S.; Durward, Marina; Radhakrishnan, Girish K.; Liu, Yi-Ping; Splitter, Gary A.
Brucella melitensis is a facultative intracellular bacterium that causes brucellosis, the most prevalent zoonosis worldwide. The Brucella intracellular replicative niche in macrophages and dendritic cells thwarts immune surveillance and complicates both therapy and vaccine development. Currently, host-pathogen interactions supporting Brucella replication are poorly understood. Brucella fuses with the endoplasmic reticulum (ER) to replicate, resulting in dramatic restructuring of the ER. This ER disruption raises the possibility that Brucella provokes an ER stress response called the Unfolded Protein Response (UPR). In this study, B. melitensis infection up regulated expression of the UPR target genes BiP, CHOP, and ERdj4, and induced XBP1 mRNA splicing in murine macrophages. These data implicate activation of all 3 major signaling pathways of the UPR. Consistent with previous reports, XBP1 mRNA splicing was largely MyD88-dependent. However, up regulation of CHOP, and ERdj4 was completely MyD88 independent. Heat killed Brucella stimulated significantly less BiP, CHOP, and ERdj4 expression, but induced XBP1 splicing. Although a Brucella VirB mutant showed relatively intact UPR induction, a TcpB mutant had significantly compromised BiP, CHOP and ERdj4 expression. Purified TcpB, a protein recently identified to modulate microtubules in a manner similar to paclitaxel, also induced UPR target gene expression and resulted in dramatic restructuring of the ER. In contrast, infection with the TcpB mutant resulted in much less ER structural disruption. Finally, tauroursodeoxycholic acid, a pharmacologic chaperone that ameliorates the UPR, significantly impaired Brucella replication in macrophages. Together, these results suggest Brucella induces a UPR, via TcpB and potentially other factors, that enables its intracellular replication. Thus, the UPR may provide a novel therapeutic target for the treatment of brucellosis. These results also have implications for other
Nielsen, Stig Lønberg; Johansen, Isik Somuncu
Brucellosis is a widespread endemic zoonotic infection affecting more than 500,000 people per year. The disease is very uncommon in Denmark and almost always imported. We present a case of a 57 year-old male with blood culture and magnetic resonance imaging verified brucella spondylodiscitis. Prior to debut of symptoms the patient had visited Lebanon where he had ingested unpasteurized goat milk. The patient was initially treated with an antimicrobial chemotherapy regimen for 12 weeks, which was prolonged due to inadequate radiological response.
Raju, I. Tammi; Solanki, Rachana; Patnaik, A.N.; Barik, R.C.; Kumari, N.R.; Gulati, A.S.
Endocarditis due to brucellosis is considered a rare occurrence involving native, congenital and prosthetic valves. The diagnosis needs high degree of suspicion in culture negative endocarditis especially in those with history of exposure to farm animals. A positive culture in a susceptible patient confirms the diagnosis with 91% sensitivity. An early diagnosis and prompt treatment with appropriate antibiotics can restore the valve structural integrity with minimal damage. Here we present a series of five cases of culture proven Brucella endocarditis (four native valves, one prosthetic valve) and this report discusses the diagnostic and management issues involved. PMID:23438616
Han, D U; Choi, C; Ham, H J; Jung, J H; Cho, W S; Kim, J; Higgins, R; Chae, C
This study was undertaken to determine the prevalence, capsular serotype, and antimicrobial susceptibility of Streptococcus suis isolated from slaughter pigs. Capsular serotype and antimicrobial susceptibility were determined by coagglutination test and agar dilution minimum inhibitory concentration, respectively. Streptococcus suis was isolated from 55 of the 406 palatine tonsillar samples tested (13.8%) and 14 of the 29 sampled herds (48.3%). Of the 55 isolates recovered from slaughter pigs, 26 (47.3%) were untypeable. Of the remaining 29 isolates, capsular serotypes 9 (9 isolates) and 16 (4 isolates) were the most common, followed by capsular serotypes 4 (3 isolates) and 7 (3 isolates). Every capsulated isolate was typeable and no palatine tonsillar sample yielded more than one serotype. Most of isolates were susceptible to low concentrations (MIC90) of amoxicillin (2 microg/mL), ceftiofur (1 microg/mL), and penicillin (1 microg/mL). No correlation was found between antimicrobial susceptibility and capsular serotype. PMID:11480519
Song, Qiqi; Zhang, Weijing; Song, Weijiao; Liu, Zehua; Khan, Muhammad Kasib; He, Lan; Fang, Rui; Li, Peng; Zhou, Yanqin; Hu, Min; Zhao, Junlong
Mycoplasma suis, the causative agent of porcine infectious anemia, causes large economic losses to the swine industry worldwide. A questionnaire-based survey was conducted in 69 pig farms in Hubei Province, China, from November 2011 to August 2013 to ascertain the prevalence and associated risk factors of M. suis. Four thousand and four blood samples from pigs of all the age groups were tested for M. suis antibodies using the established rMSG1-ELISA assay. Among these 4004 samples, 1615 blood samples from multiparous sows were examined to identify the association between seroprevalence and different seasons. Information on risk factors collected from farmers or attending veterinarians was recorded on a pre-designed questionnaire. The overall test seroprevalence of M. suis infection at the animal level was 31.9% (1277/4004; 95% CI: 30.5%, 33.4%), whereas at the farm level, this value was 95.65% (66/69; 95% CI: 87.8%, 99.1%). The seroprevalence of M. suis was higher in replacement gilts (40.6%; 95% CI: 35.1%, 46.3%), multiparous sows (48.2%; 95% CI: 45.8%, 50.7%) and boars (44.4%; 95% CI: 34.5%, 54.8%), as compared to piglets (13.0%; 95% CI: 9.4%, 17.3%), weaned-piglets (10.8%; 95% CI: 8.9%, 13.0%), and growing-finishing pigs (25.0%; 95% CI: 22.0%, 28.3%). In terms of seasons, the prevalence of M. suis in pigs was significantly higher in summer (65.3%; 95% CI: 61.0%, 69.5%) and autumn (65.0%; 95% CI: 59.0%, 70.6%) compared to spring (30.1%; 95% CI: 26.0%, 34.4%) and winter (36.4%; 95% CI: 31.4%, 41.5%). Farm-level risk factors were identified by multivariable logistic regression analysis. The associated factors retained in the final multivariable logistic regression model were drug treatment, presence of mosquitoes and flies, and frequency of disinfection. Drug treatment (OR=0.24; 95% CI: 0.07, 0.88; P=0.031) and frequency of disinfection (OR=0.23; 95% CI: 0.06, 0.90; P=0.035) were protective factors, and the presence of mosquitoes and flies (OR=5.994; 95% CI: 1
Morales, Bárbara; Ruiz, Álvaro; Lacouture, Sonia; Gottschalk, Marcelo
The characteristics of 29 Chilean field strains of Streptococcus suis recovered between 2007 and 2011 from pigs with clinical signs at different farms were studied. Serotyping with use of the coagglutination test revealed that all but 1 strain belonged to serotype 6; the remaining strain was serotype 22. All the serotype-6 strains were suilysin (hemolysin)-negative; in addition, they were found to be genotypically homogeneous by enterobacterial repetitive intergenic consensus sequence-based polymerase chain reaction (ERIC-PCR) and sensitive to ampicillin, ceftiofur, penicillin, and trimethoprim/sulfamethoxazole. The results indicate that, in contrast to what is generally observed in other countries, a single clone of S. suis was isolated from diseased pigs in the central region of Chile. PMID:26424917
Lambourne, Jonathan R; Brooks, Tim
Brucella and Coxiella are similar; both are obligate intracellular, zoonotic pathogens with a broad geographic distribution. Infection in animals is usually asymptomatic, but causes fetal loss and therefore has significant economic impact. Human infection may be asymptomatic or give rise to either organ-specific or multi-system disease. Organism culture is challenging for Coxiella and can lack sensitivity for Brucella. Therefore, infection is most commonly diagnosed by serology, but this may be negative in early infection and serology results may be challenging to interpret. Both Brucella and Coxiella are typically susceptible to a wide range of antimicrobials, but long courses may be needed.
Fulde, Marcus; Willenborg, Joerg; Huber, Claudia; Hitzmann, Angela; Willms, Daniela; Seitz, Maren; Eisenreich, Wolfgang; Valentin-Weigand, Peter; Goethe, Ralph
The arginine-ornithine antiporter (ArcD) is part of the Arginine Deiminase System (ADS), a catabolic, energy-providing pathway found in a variety of different bacterial species, including the porcine zoonotic pathogen Streptococcus suis. The ADS has recently been shown to play a role in the pathogenicity of S. suis, in particular in its survival in host cells. The contribution of arginine and arginine transport mediated by ArcD, however, has yet to be clarified. In the present study, we showed by experiments using [U-13C6]arginine as a tracer molecule that S. suis is auxotrophic for arginine and that bacterial growth depends on the uptake of extracellular arginine. To further study the role of ArcD in arginine metabolism, we generated an arcD-specific mutant strain and characterized its growth compared to the wild-type (WT) strain, a virulent serotype 2 strain. The mutant strain showed a markedly reduced growth in chemically defined media supplemented with arginine when compared to the WT strain, suggesting that ArcD promotes arginine uptake. To further evaluate the in vivo relevance of ArcD, we studied the intracellular bacterial survival of the arcD mutant strain in an epithelial cell culture infection model. The mutant strain was substantially attenuated, and its reduced intracellular survival rate correlated with a lower ability to neutralize the acidified environment. Based on these results, we propose that ArcD, by its function as an arginine-ornithine antiporter, is important for supplying arginine as substrate of the ADS and, thereby, contributes to biological fitness and virulence of S. suis in the host. PMID:25161959
Due to the age and operating experience of Bruce Power units, equipment ageing and obsolescence has become one of the main challenges that need to be resolved for all systems, structures and components in order to ensure a safe and reliable production of energy. The research objectives of this thesis will focus on methodology for modernization of Start-Up Instrumentation (SUI), both in-core and Control Room equipment, using a new generation of detectors and cables in order to manage obsolescence. The main objective of this thesis is to develop a new systematic approach to SUI installation/replacement procedure development and optimization. Although some additional features, such as real-time data monitoring and storage/archiving solutions for SUI systems are also examined to take full advantage of today's digital technology, the objective of this thesis does not include detailed parametrical studies of detector or system performance. Instead, a number of technological, operational and maintenance issues associated with Start-Up Instrumentation systems at Bruce Power will be identified in this project and a structured approach to developing a replacement/installation procedure that can be standardized and used across all of the domestic CANDU stations is proposed. Finally, benefits of Hierarchical Control Chart (HCC) methodology for all stages of plant life management, such as system design, development, operation and maintenance are demonstrated. Keywords: Task Breakdown and Analysis methodology, installation/removal procedure development and optimization, risk-based analysis and optimization, Hierarchical Control Chart (HCC) methodology for system maintenance and troubleshooting, Start-Up Instrumentation (SUI), Ion Chambers, Fission Chambers, proportional counters, Shutdown System 1 (SDS1), Shutdown System 2 (SDS2).
Cui, Y; Dinman, J D; Kinzy, T G; Peltz, S W
Although it is essential for protein synthesis to be highly accurate, a number of cases of directed ribosomal frameshifting have been reported in RNA viruses, as well as in procaryotic and eucaryotic genes. Changes in the efficiency of ribosomal frameshifting can have major effects on the ability of cells to propagate viruses which use this mechanism. Furthermore, studies of this process can illuminate the mechanisms involved in the maintenance of the normal translation reading frame. The yeast Saccharomyces cerevisiae killer virus system uses programmed -1 ribosomal frameshifting to synthesize its gene products. Strains harboring the mof2-1 allele demonstrated a fivefold increase in frameshifting and prevented killer virus propagation. In this report, we present the results of the cloning and characterization of the wild-type MOF2 gene. mof2-1 is a novel allele of SUI1, a gene previously shown to play a role in translation initiation start site selection. Strains harboring the mof2-1 allele demonstrated a mutant start site selection phenotype and increased efficiency of programmed -1 ribosomal frameshifting and conferred paromomycin sensitivity. The increased frameshifting observed in vivo was reproduced in extracts prepared from mof2-1 cells. Addition of purified wild-type Mof2p/Sui1p reduced frameshifting efficiencies to wild-type levels. Expression of the human SUI1 homolog in yeast corrects all of the mof2-1 phenotypes, demonstrating that the function of this protein is conserved throughout evolution. Taken together, these results suggest that Mof2p/Sui1p functions as a general modulator of accuracy at both the initiation and elongation phases of translation.
van Hout, Jobke; Heuvelink, Annet; Gonggrijp, Maaike
The objective of the present study was to analyse the in vitro antimicrobial susceptibility of Streptococcus suis isolates from post-mortem samples from pigs in the Netherlands. S. suis isolates originated from diagnostic submissions of pigs sent to the Pathology Department of GD Animal Health, from April 2013 till June 2015. Minimal inhibitory concentrations (MICs) of in total 15 antimicrobials were assessed by broth microdilution following CLSI recommendations. MIC50 and MIC90 values were determined and MICs were interpreted as susceptible, intermediate and resistant using CLSI veterinary breakpoints (when available). Emergence of resistance among S. suis (n=1163) derived from clinical submissions of pigs appeared to be limited. Resistance to ampicillin, ceftiofur, clindamycin, enrofloxacin, florfenicol, penicillin, trimethoprim/sulfamethoxazole and tetracycline was 0.3%, 0.5%, 48.1%, 0.6%, 0.1%, 0.5%, 3.0%, and 78.4%, respectively. Cross-resistance between penicillin and ampicillin appeared to be incomplete. MIC values of erythromycin, clindamycin, neomycin, penicillin and tilmicosin for isolates originating from grower/finisher pigs were significantly more often lower than the MIC values of isolates from suckling/weaned piglets. It has to be kept in mind that these results represent only part of the Dutch pig population and it can be discussed whether this is a representative sample. Interpretation of the MIC results of (clinically relevant) antimicrobials tested for treatment of S. suis infection is strongly hampered by the lack of CLSI-defined veterinary clinical breakpoints that are animal species- and body site-specific. Therefore, and to conduct a clinically reliable monitoring of antimicrobial susceptibility of veterinary pathogens, more species- and organ-specific veterinary breakpoints are urgently needed.
Callens, Bénédicte F; Haesebrouck, Freddy; Maes, Dominiek; Butaye, Patrick; Dewulf, Jeroen; Boyen, Filip
Streptococcus suis (S. suis) has often been reported as an important swine pathogen and is considered as a new emerging zoonotic agent. Consequently, it is important to be informed on its susceptibility to antimicrobial agents. In the current study, the Minimum Inhibitory Concentration (MIC) population distribution of nine antimicrobial agents has been determined for nasal S. suis strains, isolated from healthy pigs at the end of the fattening period from 50 closed or semiclosed pig herds. The aim of the study was to report resistance based on both clinical breakpoints (clinical resistance percentage) and epidemiological cutoff values (non-wild-type percentage). Non-wild-type percentages were high for tetracycline (98%), lincomycin (92%), tilmicosin (72%), erythromycin (70%), tylosin (66%), and low for florfenicol (0%) and enrofloxacin (0.3%). Clinical resistance percentages were high for tetracycline (95%), erythromycin (66%), tylosin (66%), and low for florfenicol (0.3%) and enrofloxacin (0.3%). For tiamulin, for which no clinical breakpoint is available, 57% of the isolates did not belong to the wild-type population. Clinical resistance and non-wild-type percentages differed substantially for penicillin. Only 1% of the tested S. suis strains was considered as clinically resistant, whereas 47% of the strains showed acquired resistance when epidemiological cutoff values were used. In conclusion, MIC values for penicillin are gradually increasing, compared to previous reports, although pigs infected with strains showing higher MICs may still respond to treatment with penicillin. The high rate of acquired resistance against tiamulin has not been reported before. Results from this study clearly demonstrate that the use of different interpretive criteria contributes to the extent of differences in reported antimicrobial resistance results. The early detection of small changes in the MIC population distribution of isolates, while clinical failure may not yet be
Vizcaíno, Nieves; Cloeckaert, Axel; Zygmunt, Michel S.; Fernández-Lago, Luis
A Brucella melitensis 16M DNA fragment of 17,119 bp, which contains a large region deleted in B. abortus strains and DNA flanking one side of the deletion, has been characterized. In addition to the previously identified omp31 gene, 14 hypothetical genes have been identified in the B. melitensis fragment, most of them showing homology to genes involved in the synthesis of a polysaccharide. Considering that 10 of the 15 genes are missing in B. abortus and that all the polysaccharides described in the Brucella genus (lipopolysaccharide, native hapten, and polysaccharide B) have been detected in all the species, it seems likely that the genes described here might be part of a cluster for the synthesis of a novel Brucella polysaccharide. Several polysaccharides have been identified as important virulence factors, and the discovery of a novel polysaccharide in the brucellae which is probably not synthesized in B. abortus might be interesting for a better understanding of the pathogenicity and host preference differences observed between the Brucella species. However, the possibility that the genes described in this paper no longer encode the synthesis of a polysaccharide cannot be excluded. Brucellae belong to the alpha-2 subdivision of the class Proteobacteria, which includes other microorganisms living in association with eucaryotic cells, some of them synthesizing extracellular polysaccharides involved in the interaction with the host cell. The genes described in this paper might be a remnant of the common ancestor of the alpha-2 subdivision of the class Proteobacteria, and the brucellae might have lost such extracellular polysaccharide during evolution if it was not necessary for survival or for establishment of the infectious process. Nevertheless, further studies are necessary to identify the entire DNA fragment missing in B. abortus strains and to elucidate the mechanism responsible for such deletion, since only 9,948 bp of the deletion was present in the
Hatten, Betty A.; Sulkin, S. Edward
Hatten, Betty A. (The University of Texas Southwestern Medical School, Dallas), and S. Edward Sulkin. Intracellular production of Brucella L forms. I. Recovery of L forms from tissue culture cells infected with Brucella abortus. J. Bacteriol. 91:285–296. 1966.—Infectivity of virulent Brucella abortus strain 3183 was less for hamster macrophages after a 2-hr adsorption period than for an attenuated strain (S19) and its tissue culture variant (30). Both strains S19 and 30 were very toxic for the cells, but 3183 was not toxic. Two types of L forms were recovered from a large percentage of hamster kidney cell cultures when disintegration of infected cells was accelerated by tissue culture medium of high pH. One type grew in finely granular microcolonies, was isolated from cells infected for short periods of time, and often reverted to the bacterial form. The other type occurred in small irregularly shaped forms which later developed into round bodies. Both stained specifically with fluorescein-conjugated B. abortus antiserum. Semisolid media containing 0.7% agar provided optimal subsurface L-form growth. L forms also grew well in Thioglycollate Medium but grew poorly in other liquid media. Surface L-form growth was supported by several agar media, but CO2 was required for optimal growth. Monolayers infected with strain 3183 and examined immediately after adsorption contained occasional small, round bodies. Bizarre forms increased in number with time and, after 24 to 72 hr, large pink-staining inclusions were often present which persisted for several days. Also appearing at about the same time were smaller, dark-staining forms which were first seen in clusters but later dispersed and finally occurred in chainlike configurations. Direct fluorescent-antibody stains of infected cells established that the intracellular forms were related to the infecting strain of B. abortus. Images PMID:16562102
Neil, D. H.; McKay, K. A.; L'Ecuyer, C.; Corner, A. H.
The intracheal inoculation of pigs with Haemophilus suis led to the production of Glasser's disease at every attempt without significant pulmonary involvement. Isolation of this organism from the experimental animals was possible only in the acute phase of the disease. The indirect fluorescent antibody technique when applied to frozen sections of tissues obtained from the experimentally infected pigs at autopsy, revealed a few rod forms but mostly “round bodies” of H. suis in animals from which the organism was isolated, and “round bodies” only in the pigs from which the organism was not isolated. Attention is drawn to the similarities between the lesions caused by H. suis and Mycoplasma hyorhinis, and to the confusion which may result therefrom. It is stressed that the laboratory diagnosis of these two diseases is complicated by the fact that both agents may not be isolated on the media commonly used in diagnostic laboratories. Both organisms necessitate the use of special media where the clinical and autopsy results indicate polyserositis and arthritis. ImagesFig. 1.Fig. 2.Fig. 3.Fig. 4. PMID:4242769
De Clercq, Evelien; Devriendt, Bert; Yin, Lizi; Chiers, Koen; Cox, Eric; Vanrompay, Daisy
The aim of the present study was to reveal the characteristic features of genital Chlamydia suis infection and re-infection in female pigs by studying the immune response, pathological changes, replication of chlamydial bacteria in the genital tract and excretion of viable bacteria. Pigs were intravaginally infected and re-infected with C. suis strain S45, the type strain of this species. We demonstrated that S45 is pathogenic for the female urogenital tract. Chlamydia replication occurred throughout the urogenital tract, causing inflammation and pathology. Furthermore, genital infection elicited both cellular and humoral immune responses. Compared to the primo-infection of pigs with C. suis, re-infection was characterized by less severe macroscopic lesions and less chlamydial elementary bodies and inclusions in the urogenital tract. This indicates the development of a certain level of protection following the initial infection. Protective immunity against re-infection coincided with higher Chlamydia-specific IgG and IgA antibody titers in sera and vaginal secretions, higher proliferative responses of peripheral blood mononuclear cells (PBMC), higher percentages of blood B lymphocytes, monocytes and CD8⁺ T cells and upregulated production of IFN-γ and IL-10 by PBMC.
Zhang, Xue-han; He, Kong-wang; Duan, Zhi-tao; Zhou, Jun-ming; Yu, Zheng-yu; Ni, Yan-xiu; Lu, Cheng-ping
Streptococcus suis type 2 is a swine pathogen responsible for diverse diseases. Although many virulent factors have been identified and studied, relatively little is known about the pathogenic mechanisms of type 2. The aim of the study was to identify and understand the characterization of Inosine 5-monophosphate dehydrogenase (IMPDH). A 957-bp gene, impdh, was identified in the virulent S. suis serotype 2 (SS2), and analysis of the predicted IMPDH sequence revealed IMP dehydrogenase/GMP reductase domain. The gene encoding for the IMPDH of S. suis was cloned and sequenced. The DNA sequence contained an open reading frame encoding for a 318 amino acid polypeptide exhibiting 23% sequence identity with the IMPDH from Streptococcus pyogenes (YP281355) and Streptococcus pneumoniae (ZP00404150). Using the pET(32) expression plasmid, the impdh gene was inducibly overexpressed in Escherichia coli to produce IMPDH with a hexahistidyl N-terminus to permit its purification. The (His)6 IMPDH protein was found to possess functional IMPDH enzymatic activity after the purification. The impdh-knockout SS2 mutant ( Delta IMPDH) constructed in this study was slower in growth and one pH unit higher than SS2-H after 6 h of culturing, and found to be attenuated in mouse models of infection for 2.5 times and not be capable of causing death in porcine models of infection in contrast with the parent SS2-H.
Doto, Daniela Sabatini; Moreno, Luisa Zanolli; Calderaro, Franco Ferraro; Matajira, Carlos Emilio Cabrera; de Moura Gomes, Vasco Tulio; Ferreira, Thais Sebastiana Porfida; Mesquita, Renan Elias; Timenetsky, Jorge; Gottschalk, Marcelo; Moreno, Andrea Micke
Streptococcus suis is an emerging zoonotic pathogen that causes septicemia, meningitis, arthritis, and pneumonia in swine and humans. The present study aimed to characterize the genetic diversity of S. suis serotype 2 isolated from pigs showing signs of illness in Brazil using pulsed-field gel electrophoresis (PFGE), single-enzyme amplified fragment length polymorphism (SE-AFLP), and profiling of virulence-associated markers. A total of 110 isolates were studied, 62.7% of which were isolated from the central nervous system and 19.1% from the respiratory tract. Eight genotypes were obtained from the combination of virulence genes, with 43.6% and 5.5% frequencies for the mrp+/epf+/sly+ and mrp−/epf−/sly− genotypes, respectively. The presence of isolates with epf gene variation with higher molecular weight also appears to be a characteristic of Brazilian S. suis serotype 2. The PFGE and SE-AFLP were able to type all isolates and, although they presented a slight tendency to cluster according to state and year of isolation, it was also evident the grouping of different herds in the same PFGE subtype and the existence of isolates originated from the same herd classified into distinct subtypes. No further correlation between the isolation sites and mrp/epf/sly genotypes was observed. PMID:27127337
Zhao, Wenqiang; Liu, Xing; Huang, Qiaoyun; Cai, Peng
Understanding pathogen sorption on natural soil particles is crucial to protect public health from soilborne and waterborne diseases. Sorption of pathogen Streptococcus suis on 10 agricultural soils was examined, and its correlations with soil physico-chemical properties were also elucidated. S. suis sorption isotherms conformed to the linear equation, with partition coefficients (Ks) ranging from 12.7 mL g(-1) to 100.1 mL g(-1). Bacteria were observed to sorb on the external surfaces of soil aggregates by scanning electron microscopy. Using Pearson correlation and linear regression analysis, solution pH was found to have significant negative correlations with Ks. Stepwise multiple regression and path analysis revealed that pH and cation exchange capacity (CEC) were the main factors influencing sorption behaviors. The obtained overall model (Ks=389.6-45.9×pH-1.3×CEC, R(2)=0.943, P<0.001) can accurately predict Ks values. However, the variability in Ks was less dependent on soil organic matter, specific surface area, soil texture and zeta potential, probably due to the internal-surface shielding phenomenon of soil aggregates. Additionally, the sorption trends cannot be interpreted by interaction energy barriers calculated using the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, suggesting the limits of DLVO theory in describing pathogen sorption on natural soils. Our results also indicated soil pH and CEC should be preferentially considered when modeling S. suis sorption process.
Doto, Daniela Sabatini; Moreno, Luisa Zanolli; Calderaro, Franco Ferraro; Matajira, Carlos Emilio Cabrera; de Moura Gomes, Vasco Tulio; Ferreira, Thais Sebastiana Porfida; Mesquita, Renan Elias; Timenetsky, Jorge; Gottschalk, Marcelo; Moreno, Andrea Micke
Streptococcus suis is an emerging zoonotic pathogen that causes septicemia, meningitis, arthritis, and pneumonia in swine and humans. The present study aimed to characterize the genetic diversity of S. suis serotype 2 isolated from pigs showing signs of illness in Brazil using pulsed-field gel electrophoresis (PFGE), single-enzyme amplified fragment length polymorphism (SE-AFLP), and profiling of virulence-associated markers. A total of 110 isolates were studied, 62.7% of which were isolated from the central nervous system and 19.1% from the respiratory tract. Eight genotypes were obtained from the combination of virulence genes, with 43.6% and 5.5% frequencies for the mrp (+) /epf (+) /sly (+) and mrp (-) /epf (-) /sly (-) genotypes, respectively. The presence of isolates with epf gene variation with higher molecular weight also appears to be a characteristic of Brazilian S. suis serotype 2. The PFGE and SE-AFLP were able to type all isolates and, although they presented a slight tendency to cluster according to state and year of isolation, it was also evident the grouping of different herds in the same PFGE subtype and the existence of isolates originated from the same herd classified into distinct subtypes. No further correlation between the isolation sites and mrp/epf/sly genotypes was observed.
Huong, V T L; Thanh, L V; Phu, V D; Trinh, D T; Inui, K; Tung, N; Oanh, N T K; Trung, N V; Hoa, N T; Bryant, J E; Horby, P W; Kinh, N V; Wertheim, H F L
Porcine reproductive and respiratory syndrome (PRRS) outbreaks in pigs are associated with increased susceptibility of pigs to secondary bacterial infections, including Streptococcus suis - an important zoonotic pathogen causing bacterial meningitis in humans. This case-control study examined the association between human S. suis infection and PRRS outbreaks in pigs in northern Vietnam. We included 90 S. suis case-patients and 183 non-S. suis sepsis controls from a referral hospital in Hanoi in 2010, a period of major PRRS epizootics in Vietnam. PRRS exposure was determined using data from the National Centre of Veterinary Diagnosis. By univariate analysis, significantly more S. suis patients were reported residing in or adjacent to a PRRS district compared to controls [odds ratio (OR) 2·82, 95% confidence interval (CI) 1·35-5·89 and OR 3·15, 95% CI 1·62-6·15, respectively]. Only residency in adjacent districts remained significantly associated with risk of S. suis infection after adjusting for sex, occupation, and eating practices. SaTScan analysis showed a possible cluster of S. suis infection in humans around PRRS confirmed locations during the March-August period. The findings indicate an epidemiological association between PRRS in pigs and S. suis infections in humans. Effective strategies to strengthen control of PRRS in pigs may help reduce transmission of S. suis infection to humans.
Faria, José P.; Edirisinghe, Janaka N.; Davis, James J.; ...
For many scientific applications, it is highly desirable to be able to compare metabolic models of closely related genomes. In this study, we attempt to raise awareness to the fact that taking annotated genomes from public repositories and using them for metabolic model reconstructions is far from being trivial due to annotation inconsistencies. We are proposing a protocol for comparative analysis of metabolic models on closely related genomes, using fifteen strains of genus Brucella, which contains pathogens of both humans and livestock. This study lead to the identification and subsequent correction of inconsistent annotations in the SEED database, as wellmore » as the identification of 31 biochemical reactions that are common to Brucella, which are not originally identified by automated metabolic reconstructions. We are currently implementing this protocol for improving automated annotations within the SEED database and these improvements have been propagated into PATRIC, Model-SEED, KBase and RAST. This method is an enabling step for the future creation of consistent annotation systems and high-quality model reconstructions that will support in predicting accurate phenotypes such as pathogenicity, media requirements or type of respiration.« less
Serre, A; Vendrell, J P; Huguet, M F; Cannat, A
Two Brucella fractions, the murein-linked fraction PI and the murein-free fraction SF, behave as in vitro adjuvants for primary anti-sheep erythrocyte responses: added to Mishell and Dutton-type cultures of spleen cells from B6/DB F1 mice they significantly enhance the number of direct anti-sheep erythrocyte PFC observed on day 5. They exert both nonspecific, polyclonal activating effects and antigen-dependent specific adjuvanticity. These two functions, however, differ in their dose responses and in their cellular requirements and can therefore be dissociated. Thus, polyclonal activation requires high doses of the "adjuvant fraction," is enhanced by adherent-cell depletion, and is not impaired by T-cell depletion. Specific adjuvanticity, on the other hand, requires lower doses of the adjuvant fractions (very high doses are in fact suppressive) and is T-cell and adherent-cell dependent. Moreover, adjuvanticity can be transferred to unstimulated spleen cells (or restored in adherent-cell-depleted populations) by PI- or SF-stimulated adherent cells or by the filtered supernatants of such cultures; adjuvant-soluble factors are therefore involved in the phenomena of adherent, T- and B-cell cooperation required for the adjuvanticity of Brucella fractions. PMID:6982864
Akdemir, Zülküf; Karaman, Erbil; Akdeniz, Hüseyin; Alptekin, Cem
Thyroid gland infection, although rare, may be a life threatening disease. Thyroid abscess, arising from acute suppurative thyroiditis (AST), is a rare clinic condition depending on widespread use of antibiotics. Infection may involve one or both lobes and abscess formation may not be apparent until late stage of the progress of illness. Thyroid left lobe is more often affected than the right one. Brucellosis, especially obvious in endemic areas, is a widely seen zoonosis around the world. Although brucella infection can affect many organs through various complications, thyroid gland infection is rare. We aimed to present ultrasonography (USG) and magnetic resonance images (MRI) of a case with an acute thyroiditis which rapidly developed and grew fast on the left half of the neck during the first postpartum month. As far as we know from literature reviewing, our case is the first case report of a thyroid abscess arising from brucella infection which is developed in first postpartum period with images of ultrasonography and MRI. PMID:25861492
Young, Edward J; Hasanjani Roushan, Mohammad Reza; Shafae, Shariar; Genta, Robert M; Taylor, Shari L
As a major organ of the mononuclear phagocytic system, the liver is probably involved in all cases of brucellosis. In this prospective study, liver slides prepared from percutaneous liver biopsy samples of 20 patients with clinical and laboratory evidence of acute brucellosis due to Brucella melitensis were examined for the presence or absence of granulomas by pathologists in Iran and the United States. Nineteen men and one woman ranging in age from 14 to 62 years were studied. All patients had clinical signs and symptoms compatible with acute brucellosis, and all had significantly elevated titers of antibodies to Brucella in their serum. Liver function tests were mildly elevated in 11 (55%) cases, and C-reactive protein was positive in 15 (65%) patients. Thirteen (65%) patients had blood cultures positive for B melitensis. Iranian and American pathologists reported granulomas in 3 (15%) and in 4 (20%) cases, respectively. There was agreement between Iranian and American pathologists in 17 (85%) cases. The most prevalent findings were mild portal or lobular lymphocytic inflammation (16 cases). Two cases revealed noncaseating epithelioid granulomas, and 2 had microgranulomas. The results show that all patients had microscopic evidence of liver involvement. The predominant histologic finding was mild portal or lobular inflammation with lymphocytes. Granulomas were present in only 4 cases.
Bosschem, Iris; Bayry, Jagadeesh; De Bruyne, Ellen; Van Deun, Kim; Smet, Annemieke; Vercauteren, Griet; Ducatelle, Richard; Haesebrouck, Freddy; Flahou, Bram
Helicobacter suis (H. suis) is a widespread porcine gastric pathogen, which is also of zoonotic importance. The first goal of this study was to investigate the efficacy of several vaccine adjuvants (CpG-DNA, Curdlan, Freund's Complete and Incomplete, Cholera toxin), administered either subcutaneously or intranasally along with H. suis whole-cell lysate, to protect against subsequent H. suis challenge in a BALB/c infection model. Subcutaneous immunization with Freund's complete (FC)/lysate and intranasal immunization with Cholera toxin (CT)/lysate were shown to be the best options for vaccination against H. suis, as determined by the amount of colonizing H. suis bacteria in the stomach, although adverse effects such as post-immunization gastritis/pseudo-pyloric metaplasia and increased mortality were observed, respectively. Therefore, we decided to test alternative strategies, including sublingual vaccine administration, to reduce the unwanted side-effects. A CCR4 antagonist that transiently inhibits the migration of regulatory T cells was also included as a new adjuvant in this second study. Results confirmed that immunization with CT (intranasally or sublingually) is among the most effective vaccination protocols, but increased mortality was still observed. In the groups immunized subcutaneously with FC/lysate and CCR4 antagonist/lysate, a significant protection was observed. Compared to the FC/lysate immunized group, gastric pseudo-pyloric metaplasia was less severe or even absent in the CCR4 antagonist/lysate immunized group. In general, an inverse correlation was observed between IFN-γ, IL-4, IL-17, KC, MIP-2 and LIX mRNA expression and H. suis colonization density, whereas lower IL-10 expression levels were observed in partially protected animals.
Bonifait, Laetitia; Vaillancourt, Katy; Gottschalk, Marcelo; Frenette, Michel; Grenier, Daniel
Streptococcus suis is a major swine pathogen that is responsible for severe infections such as meningitis, endocarditis, and septicemia. S. suis is also recognized as a zoonotic agent and expresses several virulence factors. The recently identified subtilisin-like protease (SspA) of S. suis plays an important role in the pathogenicity of this bacterium in animal models. The objective of the present study was to clone, purify, and characterize the SspA of serotype 2 S. suis P1/7. The SSU0757 gene encoding SspA was amplified and a 4798-bp DNA fragment was obtained. It was cloned into the expression plasmid pBAD/HisB and then inserted into Escherichia coli to overproduce the protein. The recombinant protease was purified by chromatography procedures and showed a molecular weight of 170 kDa by SDS-PAGE. Its activity was optimal at pH 7 and at temperatures ranging from 25°C to 37°C. It had a high specificity for the chromogenic substrate succinyl-Ala-Ala-Pro-Phe-pNa while specific inhibitors of serine proteases inhibited its activity. In addition to degrading gelatin, the protease hydrolyzed the Aα chain of fibrinogen, which prevented fibrin formation by thrombin. The recombinant subtilisin-like protease also showed toxicity towards brain microvascular endothelial cells. Lastly, sera from pigs infected with S. suis reacted with the recombinant SspA, indicating that it is produced during infections. In conclusion, the SspA of S. suis shared similarities with subtilisin-like proteases produced by other pathogenic streptococci and may contribute to the pathogenic process of S. suis infections.
Felder, Kathrin M.; Carranza, Paula M.; Gehrig, Peter M.; Roschitzki, Bernd; Barkow-Oesterreicher, Simon; Hoelzle, Katharina; Riedel, Katharina; Kube, Michael
Hemotrophic mycoplasmas, bacteria without cell walls whose niche is the erythrocytes of their hosts, have never been cultivated in vitro. Therefore, knowledge of their pathogenesis is fundamental. Mycoplasma suis infects pigs, causing either acute fatal hemolytic anemia or chronic low-grade anemia, growth retardation, and immune suppression. Recently, the complete genomes of two hemotrophic mycoplasma species, M. suis and M. haemofelis, were sequenced, offering new strategies for the analysis of their pathogenesis. In this study we implemented a proteomic approach to identify M. suis proteins during acute infection by using tandem mass spectrometry. Twenty-two percent of the predicted proteins encoded in M. suis strain KI_3806 were identified. These included nearly all encoded proteins of glycolysis and nucleotide metabolism. The proteins for lipid metabolism, however, were underrepresented. A high proportion of the detected proteins are involved in information storage and processing (72.6%). In addition, several proteins of different functionalities, i.e., posttranslational modification, membrane genesis, signal transduction, intracellular trafficking, inorganic ion transport, and defense mechanisms, were identified. In its reduced genome, M. suis harbors 65.3% (strain Illinois) and 65.9% (strain KI_3806) of the genes encode hypothetical proteins. Of these, only 6.3% were identified at the proteome level. All proteins identified in this study are present in both M. suis strains and are encoded in more highly conserved regions of the genome sequence. In conclusion, our proteome approach is a further step toward the elucidation of the pathogenesis and life cycle of M. suis as well as the establishment of an in vitro cultivation system. PMID:22267506
Ngo, Thi Hoa; Tran, Thi Bich Chieu; Tran, Thi Thu Nga; Nguyen, Van Dung; Campbell, James; Pham, Hong Anh; Huynh, Huu Tho; Nguyen, Van Vinh Chau; Bryant, Juliet E; Tran, Tinh Hien; Farrar, Jeremy; Schultsz, Constance
Streptococcus suis is a pathogen of major economic significance to the swine industry and is increasingly recognized as an emerging zoonotic agent in Asia. In Vietnam, S. suis is the leading cause of bacterial meningitis in adult humans. Zoonotic transmission is most frequently associated with serotype 2 strains and occupational exposure to pigs or consumption of infected pork. To gain insight into the role of pigs for human consumption as a reservoir for zoonotic infection in southern Vietnam, we determined the prevalence and diversity of S. suis carriage in healthy slaughterhouse pigs. Nasopharyngeal tonsils were sampled from pigs at slaughterhouses serving six provinces in southern Vietnam and Ho Chi Minh City area from September 2006 to November 2007. Samples were screened by bacterial culture. Isolates of S. suis were serotyped and characterized by multi locus sequence typing (MLST) and pulse field gel electrophoresis (PFGE). Antibiotic susceptibility profiles and associated genetic resistance determinants, and the presence of putative virulence factors were determined. 41% (222/542) of pigs carried S. suis of one or multiple serotypes. 8% (45/542) carried S. suis serotype 2 which was the most common serotype found (45/317 strains, 14%). 80% of serotype 2 strains belonged to the MLST clonal complex 1,which was previously associated with meningitis cases in Vietnam and outbreaks of severe disease in China in 1998 and 2005. These strains clustered with representative strains isolated from patients with meningitis in PFGE analysis, and showed similar antimicrobial resistance and virulence factor profiles. Slaughterhouse pigs are a major reservoir of S. suis serotype 2 capable of causing human infection in southern Vietnam. Strict hygiene at processing facilities, and health education programs addressing food safety and proper handling of pork should be encouraged.
Hoa, Ngo Thi; Chieu, Tran Thi Bich; Nga, Tran Thi Thu; Dung, Nguyen Van; Campbell, James; Anh, Pham Hong; Huu Tho, Huynh; Van Vinh Chau, Nguyen; Bryant, Juliet E.; Hien, Tran Tinh; Farrar, Jeremy; Schultsz, Constance
Streptococcus suis is a pathogen of major economic significance to the swine industry and is increasingly recognized as an emerging zoonotic agent in Asia. In Vietnam, S. suis is the leading cause of bacterial meningitis in adult humans. Zoonotic transmission is most frequently associated with serotype 2 strains and occupational exposure to pigs or consumption of infected pork. To gain insight into the role of pigs for human consumption as a reservoir for zoonotic infection in southern Vietnam, we determined the prevalence and diversity of S. suis carriage in healthy slaughterhouse pigs. Nasopharyngeal tonsils were sampled from pigs at slaughterhouses serving six provinces in southern Vietnam and Ho Chi Minh City area from September 2006 to November 2007. Samples were screened by bacterial culture. Isolates of S. suis were serotyped and characterized by multi locus sequence typing (MLST) and pulse field gel electrophoresis (PFGE). Antibiotic susceptibility profiles and associated genetic resistance determinants, and the presence of putative virulence factors were determined. 41% (222/542) of pigs carried S. suis of one or multiple serotypes. 8% (45/542) carried S. suis serotype 2 which was the most common serotype found (45/317 strains, 14%). 80% of serotype 2 strains belonged to the MLST clonal complex 1,which was previously associated with meningitis cases in Vietnam and outbreaks of severe disease in China in 1998 and 2005. These strains clustered with representative strains isolated from patients with meningitis in PFGE analysis, and showed similar antimicrobial resistance and virulence factor profiles. Slaughterhouse pigs are a major reservoir of S. suis serotype 2 capable of causing human infection in southern Vietnam. Strict hygiene at processing facilities, and health education programs addressing food safety and proper handling of pork should be encouraged. PMID:21464930
Kiran, Jangampalli Adi Pradeep; Chakravarthi, Veeraraghavulu Praveen; Kumar, Yellapu Nanda; Rekha, Somesula Swapna; Kruti, Srinivasan Shanthi; Bhaskar, Matcha
Computational genomics is one of the important tools to understand the distribution of closely related genomes including simple sequence repeats (SSRs) in an organism, which gives valuable information regarding genetic variations. The central objective of the present study was to screen the SSRs distributed in coding and non-coding regions among different human Brucella species which are involved in a range of pathological disorders. Computational analysis of the SSRs in the Brucella indicates few deviations from expected random models. Statistical analysis also reveals that tri-nucleotide SSRs are overrepresented and tetranucleotide SSRs underrepresented in Brucella genomes. From the data, it can be suggested that over expressed tri-nucleotide SSRs in genomic and coding regions might be responsible in the generation of functional variation of proteins expressed which in turn may lead to different pathogenicity, virulence determinants, stress response genes, transcription regulators and host adaptation proteins of Brucella genomes. Abbreviations SSRs - Simple Sequence Repeats, ORFs - Open Reading Frames. PMID:21738309
Rahman, A K M A; Saegerman, C; Berkvens, D; Melzer, F; Neubauer, H; Fretin, D; Abatih, E; Dhand, N; Ward, M P
To determine the role of different Brucella (B.) spp. in Bangladesh, 62 animal samples and 500 human sera were tested. Animal samples from cattle, goats and sheep (including milk, bull semen, vaginal swabs and placentas) were cultured for Brucella spp. Three test-positive human sera and all animal samples were screened by Brucella genus-specific real-time PCR (RT-PCR), and positive samples were then tested by IS711 RT-PCR to detect B. abortus and B. melitensis DNA. Only B. abortus DNA was amplified from 13 human and six animal samples. This is the first report describing B. abortus as the aetiological agent of brucellosis in occupationally exposed humans in Bangladesh. Of note is failure to detect B. melitensis DNA, the species most often associated with human brucellosis worldwide. Further studies are required to explore the occurrence of Brucella melitensis in Bangladesh.
Background Brucella is a group of bacteria that causes brucellosis, which can affect population health and reproductive success in many marine mammals. We investigated the serological prevalence of antibodies against Brucella bacteria in a declining harbor seal population in Glacier Bay National Park, Alaska. Results Prevalence ranged from 16 to 74 percent for those tests detecting antibodies, indicating that harbor seals in Glacier Bay have been exposed to Brucella bacteria. However, the actual level of serological prevalence could not be determined because results were strongly assay-dependent. Conclusions This study reinforces the need to carefully consider assay choice when comparing different studies on the prevalence of anti–Brucella antibodies in pinnipeds and further highlights the need for species- or taxon-specific assay validation for both pathogen and host species. PMID:23324565
Yao, Lan; Wu, Chang-Xian; Zheng, Ke; Xu, Xian-Jin; Zhang, Hui; Chen, Chuang-Fu; Liu, Zheng-Fei
Brucellae are facultative intracellular bacterial pathogens of a zoonotic disease called brucellosis. Live attenuated vaccines are utilized for prophylaxis of brucellosis; however, they retain residual virulence to human and/or animals, as well as interfere with diagnosis. In this study, recombinant virus PRV ΔTK/ΔgE/bp26 was screened and purified. One-step growth curve assay showed that the titer of recombinant virus was comparable to the parent strain. Mice experiments showed the recombinant virus elicited high titer of humoral antibodies against Brucella detected by enzyme-linked immunosorbent assay and against PRV by serum neutralization test. The recombinant virus induced high level of Brucella-specific lymphocyte proliferation response and production of interferon gamma. Collectively, these data suggest that the bivalent virus was capable of inducing both humoral and cellular immunity, and had the potential to be a vaccine candidate to prevent Brucella and/or pseudorabies virus infections.
Gao, Guangjun; Xu, Jie
Brucellosis caused by Brucella spp. is a common zoonosis in many parts of the world. Humans are infected through contact with infected animals or their dirty products. Many mechanisms are needed for this successful infection, although the mechanisms are still unclear. Host immune response and some signaling molecules play an important role in the infection event. Bacterial pathogens operate by attacking crucial intracellular pathways or some important molecules in each of these pathways for survival in their hosts. The crucial components (molecules) of immunity or pathway play a critical role in the whole process of Brucella infection. Here we summarize the findings of the Brucella-host interactions' immune system and signaling molecular cascades involved in the TLR-initiated immune response to Brucella spp. infection. The paper serves to deepen our understanding of this complex process and to provide some clues regarding the discovery of drug targets for prevention and control.
Gomez, Gabriel; Adams, Leslie G; Rice-Ficht, Allison; Ficht, Thomas A
Vaccination is the most important approach to counteract infectious diseases. Thus, the development of new and improved vaccines for existing, emerging, and re-emerging diseases is an area of great interest to the scientific community and general public. Traditional approaches to subunit antigen discovery and vaccine development lack consideration for the critical aspects of public safety and activation of relevant protective host immunity. The availability of genomic sequences for pathogenic Brucella spp. and their hosts have led to development of systems-wide analytical tools that have provided a better understanding of host and pathogen physiology while also beginning to unravel the intricacies at the host-pathogen interface. Advances in pathogen biology, host immunology, and host-agent interactions have the potential to serve as a platform for the design and implementation of better-targeted antigen discovery approaches. With emphasis on Brucella spp., we probe the biological aspects of host and pathogen that merit consideration in the targeted design of subunit antigen discovery and vaccine development.
Lim, Jeong Ju; Kim, Dong Hyeok; Lee, Jin Ju; Kim, Dae Geun; Min, Wongi; Lee, Hu Jang; Rhee, Man Hee; Kim, Suk
The outer membrane proteins (OMPs) of Brucella (B.) abortus have been extensively studied, but their immunogenicity and protective ability against B. abortus infection are still unclear. In the present study, B. abortus Omp28, a group 3 antigen, was amplified by PCR and cloned into a maltose fusion protein expression system. Recombinant Omp28 (rOmp28) was expressed in Escherichia coli and was then purified. Immunogenicity of rOmp28 was confirmed by Western blot analysis with Brucella-positive mouse serum. Furthermore, humoral- or cell-mediated immune responses measured by the production of IgG1 or IgG2a in rOmp28-immunized mice and the ability of rOmp28 immunization to protect against B. abortus infection were evaluated in a mouse model. In the immunogenicity analysis, the mean titers of IgG1 and IgG2a produced by rOmp28-immunized mice were 20-fold higher than those of PBS-treated mice throughout the entire experimental period. Furthermore, spleen proliferation and bacterial burden in the spleen of rOmp28-immunized mice were approximately 1.5-fold lower than those of PBS-treated mice when challenged with virulent B. abortus. These findings suggest that rOmp28 from B. abortus is a good candidate for manufacturing an effective subunit vaccine against B. abortus infection in animals.
Hop, Huynh Tan; Reyes, Alisha Wehdnesday Bernardo; Simborio, Hannah Leah Tadeja; Arayan, Lauren Togonon; Min, Won Gi; Lee, Hu Jang; Lee, Jin Ju; Chang, Hong Hee; Kim, Suk
In this study, the Brucella abortus ohr gene coding for an organic hydroperoxide resistance protein (Ohr) was cloned into a maltose fusion protein expression system (pMAL), inserted into Escherichia coli, and purified, and its immunogenicity was evaluated by western blot analysis using Brucella-positive mouse sera. The purified recombinant Ohr (rOhr) was treated with adjuvant and injected intraperitoneally into BALB/c mice. A protective immune response analysis revealed that rOhr induced a significant increase in both the IgG1 and IgG2a titers, and IgG2a reached a higher level than IgG1 after the second and third immunizations. Additionally, immunization with rOhr induced high production of IFN-γ as well as proinflammatory cytokines such as TNF, MCP-1, IL-12p70, and IL-6, but a lesser amount of IL-10, suggesting that rOhr predominantly elicited a cell-mediated immune response. In addition, immunization with rOhr caused a significantly higher degree of protection against a virulent B. abortus infection compared with a positive control group consisting of mice immunized with maltose-binding protein. These findings showed that B. abortus rOhr was able to induce both humoral and cell-mediated immunity in mice, which suggested that this recombinant protein could be a potential vaccine candidate for animal brucellosis.
Gomez, Gabriel; Adams, Leslie G.; Rice-Ficht, Allison; Ficht, Thomas A.
Vaccination is the most important approach to counteract infectious diseases. Thus, the development of new and improved vaccines for existing, emerging, and re-emerging diseases is an area of great interest to the scientific community and general public. Traditional approaches to subunit antigen discovery and vaccine development lack consideration for the critical aspects of public safety and activation of relevant protective host immunity. The availability of genomic sequences for pathogenic Brucella spp. and their hosts have led to development of systems-wide analytical tools that have provided a better understanding of host and pathogen physiology while also beginning to unravel the intricacies at the host-pathogen interface. Advances in pathogen biology, host immunology, and host-agent interactions have the potential to serve as a platform for the design and implementation of better-targeted antigen discovery approaches. With emphasis on Brucella spp., we probe the biological aspects of host and pathogen that merit consideration in the targeted design of subunit antigen discovery and vaccine development. PMID:23720712
Xulong, Lang; Hailong, Qu; Zhaoyang, Bu; Yanling, Yang; Chunhui, Sun; Xiaoyan, Li; Jinglong, Wang; Jinshan, Cai; Ruilin, Ma; Yijuan, Fu; Xinglong, Wang
The seroprevalence of Brucella infection in yaks was surveyed on the Qinghai-Tibet plateau of China in 2010. A total of 621 serum samples was collected from six counties and were tested by serum agglutination test. The results showed that 56 (9%) of the samples were positive for Brucella. The results of the present investigation indicate that brucellosis is common in yaks on the Qinghai-Tibet plateau of China.
Papadopoulos, Alexia; Gagnaire, Aurélie; Degos, Clara; de Chastellier, Chantal; Gorvel, Jean-Pierre
Brucella is a Gram-negative bacterium responsible for brucellosis, a worldwide re-emerging zoonosis. Brucella has been shown to infect and replicate within Granulocyte macrophage colony-stimulating factor (GMCSF) in vitro grown bone marrow-derived dendritic cells (BMDC). In this cell model, Brucella can efficiently control BMDC maturation. However, it has been shown that Brucella infection in vivo induces spleen dendritic cells (DC) migration and maturation. As DCs form a complex network composed by several subpopulations, differences observed may be due to different interactions between Brucella and DC subsets. Here, we compare Brucella interaction with several in vitro BMDC models. The present study shows that Brucella is capable of replicating in all the BMDC models tested with a high infection rate at early time points in GMCSF-IL15 DCs and Flt3l DCs. GMCSF-IL15 DCs and Flt3l DCs are more activated than the other studied DC models and consequently intracellular bacteria are not efficiently targeted to the ER replicative niche. Interestingly, GMCSF-DC and GMCSF-Flt3l DC response to infection is comparable. However, the key difference between these 2 models concerns IL10 secretion by GMCSF DCs observed at 48 h post-infection. IL10 secretion can explain the weak secretion of IL12p70 and TNFα in the GMCSF-DC model and the low level of maturation observed when compared to GMCSF-IL15 DCs and Flt3l DCs. These models provide good tools to understand how Brucella induce DC maturation in vivo and may lead to new therapeutic design using DCs as cellular vaccines capable of enhancing immune response against pathogens.
Scholz, Holger C; Mühldorfer, Kristin; Shilton, Cathy; Benedict, Suresh; Whatmore, Adrian M; Blom, Jochen; Eisenberg, Tobias
The genus Brucella comprises various species of both veterinary and human medical importance. All species are genetically highly related to each other, sharing intra-species average nucleotide identities (ANI) of > 99%. Infections occur among various warm-blooded animal species, marine mammals, and humans. Until recently, amphibians had not been recognized as a host for Brucella. In this study, however, we show that novel Brucella species are distributed among exotic frogs worldwide. Comparative recA gene analysis of 36 frog isolates from various continents and different frog species revealed an unexpected high genetic diversity, not observed among classical Brucella species. In phylogenetic reconstructions the isolates consequently formed various clusters and grouped together with atypical more distantly related brucellae, like B. inopinata, strain BO2, and Australian isolates from rodents, some of which were isolated as human pathogens. Of one frog isolate (10RB9215) the genome sequence was determined. Comparative genome analysis of this isolate and the classical Brucella species revealed additional genetic material, absent from classical Brucella species but present in Ochrobactrum, the closest genetic neighbor of Brucella, and in other soil associated genera of the Alphaproteobacteria. The presence of gene clusters encoding for additional metabolic functions, flanked by tRNAs and mobile genetic elements, as well as by bacteriophages is suggestive for a different ecology compared to classical Brucella species. Furthermore it suggests that amphibian isolates may represent a link between free living soil saprophytes and the pathogenic Brucella with a preferred intracellular habitat. We therefore assume that brucellae from frogs have a reservoir in soil and, in contrast to classical brucellae, undergo extensive horizontal gene transfer.
Scholz, Holger C.; Mühldorfer, Kristin; Shilton, Cathy; Benedict, Suresh; Whatmore, Adrian M.; Blom, Jochen; Eisenberg, Tobias
The genus Brucella comprises various species of both veterinary and human medical importance. All species are genetically highly related to each other, sharing intra-species average nucleotide identities (ANI) of > 99%. Infections occur among various warm-blooded animal species, marine mammals, and humans. Until recently, amphibians had not been recognized as a host for Brucella. In this study, however, we show that novel Brucella species are distributed among exotic frogs worldwide. Comparative recA gene analysis of 36 frog isolates from various continents and different frog species revealed an unexpected high genetic diversity, not observed among classical Brucella species. In phylogenetic reconstructions the isolates consequently formed various clusters and grouped together with atypical more distantly related brucellae, like B. inopinata, strain BO2, and Australian isolates from rodents, some of which were isolated as human pathogens. Of one frog isolate (10RB9215) the genome sequence was determined. Comparative genome analysis of this isolate and the classical Brucella species revealed additional genetic material, absent from classical Brucella species but present in Ochrobactrum, the closest genetic neighbor of Brucella, and in other soil associated genera of the Alphaproteobacteria. The presence of gene clusters encoding for additional metabolic functions, flanked by tRNAs and mobile genetic elements, as well as by bacteriophages is suggestive for a different ecology compared to classical Brucella species. Furthermore it suggests that amphibian isolates may represent a link between free living soil saprophytes and the pathogenic Brucella with a preferred intracellular habitat. We therefore assume that brucellae from frogs have a reservoir in soil and, in contrast to classical brucellae, undergo extensive horizontal gene transfer. PMID:28036367
Damiano, Maria Alessandra; Bastianelli, Daniela; Al Dahouk, Sascha; Köhler, Stephan; Cloeckaert, Axel; De Biase, Daniela; Occhialini, Alessandra
Brucella is an expanding genus of major zoonotic pathogens, including at least 10 genetically very close species occupying a wide range of niches from soil to wildlife, livestock, and humans. Recently, we have shown that in the new species Brucella microti, the glutamate decarboxylase (Gad)-dependent system (GAD system) contributes to survival at a pH of 2.5 and also to infection in mice by the oral route. In order to study the functionality of the GAD system in the genus Brucella, 47 isolates, representative of all known species and strains of this genus, and 16 strains of the closest neighbor genus, Ochrobactrum, were studied using microbiological, biochemical, and genetic approaches. In agreement with the genome sequences, the GAD system of classical species was not functional, unlike that of most strains of Brucella ceti, Brucella pinnipedialis, and newly described species (B. microti, Brucella inopinata BO1, B. inopinata-like BO2, and Brucella sp. isolated from bullfrogs). In the presence of glutamate, these species were more acid resistant in vitro than classical terrestrial brucellae. Expression in trans of the gad locus from representative Brucella species in the Escherichia coli MG1655 mutant strain lacking the GAD system restored the acid-resistant phenotype. The highly conserved GAD system of the newly described or atypical Brucella species may play an important role in their adaptation to acidic external and host environments. Furthermore, the GAD phenotype was shown to be a useful diagnostic tool to distinguish these latter Brucella strains from Ochrobactrum and from classical terrestrial pathogenic Brucella species, which are GAD negative.
Hamdy, Mahmoud E R; Amin, A S
One hundred and three milk samples were collected from 52 cows, 21 ewes, 18 goats and 12 camels. The animals tested positive to at least one of the following: (1) standard tube agglutination test (SAT); (2) Rose Bengal plate test (RBPT); (3) milk ring test (MRT). All milk samples were examined by culture and single-step polymerase chain reaction (PCR) techniques for detection of Brucella species. The PCR assay amplified Brucella-DNA from 29 bovine milk samples, 10 from sheep, 13 from goats and one from a camel. The direct culture method detected Brucella organisms from 24 samples of cows' milk, 12 from sheep, 10 from goats and failed to detect any Brucella organisms from camels' milk. PCR detected up to 100 colony forming units (CFU) of B. abortus per millilitre of milk in 100% of diluted milk samples, and 1000 CFU of B. melitensis from 70% of milk samples. Although the overall sensitivity of the PCR was higher than the culture method, it should be possible to increase the sensitivity to detect lower numbers of Brucella organisms in field samples. The speed and sensitivity of the PCR assay suggest that this technique could be useful for detection of Brucella organisms in bovine milk, as well as in sheep, goat, and camels milk.
Al Dahouk, Sascha; Tomaso, Herbert; Prenger-Berninghoff, Ellen; Splettstoesser, Wolf D; Scholz, Holger C; Neubauer, Heinrich
Brucellosis is a worldwide zoonosis causing reproductive failures in livestock and a severe multi-organ disease in humans. The genus Brucella is divided into seven species and various biotypes differing in pathogenicity and host specificity. Although Brucella spp. represent a highly homogenous group of bacteria, RFLPs of selected genes display sufficient polymorphism to distinguish Brucella species and biovars. PCR-RFLP analysis shows excellent typeability, reproducibility, stability, and epidemiological concordance. Consequently, PCR-RFLP assays of specific gene loci can serve as tools for diagnostic, epidemiological, taxonomic, and evolutionary studies. Various PCR-RFLPs used for the identification of Brucella species and biotypes are reviewed.
Zheng, Han; Qiu, Xiaotong; Roy, David; Segura, Mariela; Du, Pengchen; Xu, Jianguo; Gottschalk, Marcelo
Streptococcus suis (S. suis) is an important swine pathogen and an emerging zoonotic agent. Most clinical S. suis strains express capsular polysaccharides (CPS), which can be typed by antisera using the coagglutination test. In this study, 79 S. suis strains recovered from diseased pigs in Canada and which could not be typed using antisera were further characterized by capsular gene typing and sequencing. Four patterns of cps locus were observed: (1) fifteen strains were grouped into previously reported serotypes but presented several mutations in their cps loci, when compared to available data from reference strains; (2) seven strains presented a complete deletion of the cps locus, which would result in an inability to synthesize capsule; (3) forty-seven strains were classified in recently described novel cps loci (NCLs); and (4) ten strains carried novel NCLs not previously described. Different virulence gene profiles (based on the presence of mrp, epf, and/or sly) were observed in these non-serotypeable strains. This study provides further insight in understanding the genetic characteristics of cps loci in non-serotypeable S. suis strains recovered from diseased animals. When using a combination of the previously described 35 serotypes and the complete NCL system, the number of untypeable strains recovered from diseased animals in Canada would be significantly reduced.
Yao, Xinyue; Li, Ming; Wang, Jing; Wang, Changjun; Hu, Dan; Zheng, Feng; Pan, Xiuzhen; Tan, Yinling; Zhao, Yan; Hu, Liwen; Tang, Jiaqi; Hu, Fuquan
Streptococcus suis, an emerging infectious pathogen, is the cause of two large-scale outbreaks of human streptococcal toxic shock syndrome in China, and has attracted much attention from the scientific community. The genetic basis of its pathogenesis remains enigmatic, and no effective prevention measures have been established. To better understand the virulence differentiation of S. suis and develop a promising vaccine, we isolated and sequenced a native avirulent S. suis strain (05HAS68). Animal experiments revealed that 05HAS68 is an avirulent strain and could protect piglets from the attack of virulent strains. Comparative genomics analyses demonstrated the genetic basis for the lack of virulence in 05HAS68, which is characterized by the absence of some important virulence-associated factors and the intact 89K pathogenicity island. Lack of virulence was also illustrated by reduced survival of 05HAS68 compared to a virulent strain in pig whole blood. Further investigations revealed a large-scale genomic rearrangement in 05HAS68, which was proposed to be mediated by transposase genes and/or prophages. This genomic rearrangement may have caused the genomic diversity of S. suis, and resulted in biological discrepancies between 05HAS68 and highly virulent S. suis strains. PMID:25891917
Willemse, N.; Howell, K. J.; Weinert, L. A.; Heuvelink, A.; Pannekoek, Y.; Wagenaar, J. A.; Smith, H. E.; van der Ende, A.; Schultsz, C.
Streptococcus suis is a zoonotic swine pathogen and a major public health concern in Asia, where it emerged as an important cause of bacterial meningitis in adults. While associated with food-borne transmission in Asia, zoonotic S. suis infections are mainly occupational hazards elsewhere. To identify genomic differences that can explain zoonotic potential, we compared whole genomes of 98 S. suis isolates from human patients and pigs with invasive disease in the Netherlands, and validated our observations with 18 complete and publicly available sequences. Zoonotic isolates have smaller genomes than non-zoonotic isolates, but contain more virulence factors. We identified a zoonotic S. suis clone that diverged from a non-zoonotic clone by means of gene loss, a capsule switch, and acquisition of a two-component signalling system in the late 19th century, when foreign pig breeds were introduced. Our results indicate that zoonotic potential of S. suis results from gene loss, recombination and horizontal gene transfer events. PMID:27381348
Berthelot-Hérault, Florence; Marois, Corinne; Gottschalk, Marcelo; Kobisch, Marylène
The genetic diversity of 123 Streptococcus suis strains of capsular types 2, 1/2, 3, 7, and 9, isolated from pigs in France and from humans in different countries, was evaluated by pulsed-field gel electrophoresis (PFGE) of DNA restricted with SmaI. The method was highly discriminative (D = 0.98), results were reproducible, and the PFGE analysis was easy to interpret. Among all S. suis strains, 74 PFGE patterns were shown. At 60% homology, three groups (A, B, and C) were identified, and at 69% homology, eight subgroups (a to h) were observed. Strains isolated from diseased pigs or from humans were statistically clustered in group B, especially in subgroup d. By contrast, S. suis strains isolated from clinically healthy pigs were preferentially included in subgroup b of group A. Relationships could be established between capsular types 1/2, 3, and 9 and groups A, e, and B, respectively. S. suis strains isolated from humans were homogeneous, and a very high level of association between these strains and four DNA patterns was observed. The PFGE used in this study is a very useful tool for evaluating the genetic diversity of S. suis strains, and it would be used for epidemiological investigations. PMID:11825980
Berthelot-Hérault, Florence; Marois, Corinne; Gottschalk, Marcelo; Kobisch, Marylène
The genetic diversity of 123 Streptococcus suis strains of capsular types 2, 1/2, 3, 7, and 9, isolated from pigs in France and from humans in different countries, was evaluated by pulsed-field gel electrophoresis (PFGE) of DNA restricted with SmaI. The method was highly discriminative (D = 0.98), results were reproducible, and the PFGE analysis was easy to interpret. Among all S. suis strains, 74 PFGE patterns were shown. At 60% homology, three groups (A, B, and C) were identified, and at 69% homology, eight subgroups (a to h) were observed. Strains isolated from diseased pigs or from humans were statistically clustered in group B, especially in subgroup d. By contrast, S. suis strains isolated from clinically healthy pigs were preferentially included in subgroup b of group A. Relationships could be established between capsular types 1/2, 3, and 9 and groups A, e, and B, respectively. S. suis strains isolated from humans were homogeneous, and a very high level of association between these strains and four DNA patterns was observed. The PFGE used in this study is a very useful tool for evaluating the genetic diversity of S. suis strains, and it would be used for epidemiological investigations.
Marie, J; Morvan, H; Berthelot-Hérault, F; Sanders, P; Kempf, I; Gautier-Bouchardon, A V; Jouy, E; Kobisch, M
The susceptibility of 135 Streptococcus suis strains isolated from pigs (n = 110) and from humans (n = 25) to 13 antimicrobial agents was studied by microdilution and disc diffusion methods using Mueller-Hinton Agar II (MH) supplemented with either defibrinated sheep blood (MHSB) or horse serum (MHHS). Results were similar for both methods used except for penicillin G whose zone diameters were reduced with MHSB compared with MHHS. When MH was supplemented with sheep blood, 39% of S. suis strains classified as penicillin susceptible by MHHS microdilution showed intermediate susceptibility. Nearly all strains were susceptible to penicillin G (except by disc diffusion in MHSB), amoxicillin, ceftiofur, florfenicol, gentamicin and bacitracin. The least active antimicrobial agents were doxycycline and macrolides/lincosamides. High-level resistance (MIC > 500 mg/L or zone diameters < 10 mm) to streptomycin and kanamycin was detected in only a few strains. The virulence of strains did not seem to be related to antimicrobial resistance because no statistical difference was reported between the proportion of resistant strains of S. suis isolated from pigs with meningitis, septicaemia and arthritis, and those from tonsils and nasal cavities. However, significant differences were found in the proportions of macrolide- or doxycycline-resistant strains between S. suis serotype 2 and other serotypes. The results of antibiotic susceptibility testing presented in this study indicate that beta-lactams can be used in empirical treatment of human and pig S. suis infections in France.
Sidamonidze, K; Ramishvili, M; Kalandadze, I; Tsereteli, D; Nikolich, M P
In 2009-2013, 851 cases of brucellosis were registered in Georgia. Most cases of brucellosis were found in eastern Georgia (91.3% of cases). Mainly men were infected with brucellosis (81.0%).The age group with the most frequent cases of brucellosis is 30-59 years (48.5%). Brucellosis is rarely found among children(0-4 years - 2.0%, 5-14 years - 8.0%). Brucellosis cases were linked to professional activity; mainly by farmers (33.0% of those infected) and shepherds (27.0%). Biotyping Brucella by microbiological methods alone has limitations, so molecular typing was implemented in this study to confirm species. Isolates from human blood and ruminant milk or blood were identified by a bacteriological algorithm and confirmed by real-time PCR (Brucella T1, Idaho Technology). Species identity was confirmed using the AMOS conventional PCR assay, which differentiates four human pathogenic species but cannot recognize certain biovars within them. This gap was addressed by using more universal species-specific Single Nucleotide Polymorphism (SNP) assays. Real-time PCR was used to confirm 86 Brucella strains (48 human, 38 animal isolates) obtained 2009-2011. AMOS PCR supported the biochemical test results for 53 B. melitensis and four B. abortus strains, but not for 29 suspected B. abortus human and animal isolates. SNP typing of all 86 isolates supported the AMOS PCR results but also confirmed the species of the 29 strains not amplified by AMOS PCR. In 2009-2013 years the prevalence of brucellosis was still high. Nowadays cases of brucellosis are higher in the western part of Georgia than in the 1991-2005 period by a factor of 2.62. Brucellosis continues to be mainly an infection in males, because men are mostly engaged in sheep and cattle care. Combined AMOS PCR and SNP typing in this study provided the first genetic confirmation that both B. abortus and B. melitensis are actively circulating in humans and animals in Georgia.
Guilloteau, Laurence A.; Dornand, Jacques; Gross, Antoine; Olivier, Michel; Cortade, Fabienne; Vern, Yves Le; Kerboeuf, Dominique
Brucella, the causative agent of brucellosis in animals and humans, can survive and proliferate within macrophages. Macrophages mediate mouse resistance to various pathogens through the expression of the Nramp1 gene. The role of this gene in the control of Brucella infection was investigated. When BALB/c mice (Nramp1s) and C.CB congenic mice (Nramp1r) were infected with Brucella melitensis, the number of Brucella organisms per spleen was significantly larger in the C.CB mice than in the BALB/c mice during the first week postinfection (p.i.). This Nramp1-linked susceptibility to Brucella was temporary, since similar numbers of Brucella were recovered from the two strains of mice 2 weeks p.i. The effect of Nramp1 expression occurred within splenocytes intracellularly infected by Brucella. However, there was no difference between in vitro replication rates of Brucella in macrophages isolated from the two strains of mice infected in vivo or in Nramp1 RAW264 transfectants. In mice, infection with Brucella induced an inflammatory response, resulting in splenomegaly and recruitment of phagocytes in the spleen, which was amplified in C.CB mice. Reverse transcription-PCR (RT-PCR), performed 5 days p.i., showed that inducible nitric oxide synthase, tumor necrosis factor alpha (TNF-α), interleukin-12 p40 (IL-12p40), gamma interferon (IFN-γ), and IL-10 mRNAs were similarly induced in spleens of the two strains. In contrast, the mRNA of KC, a C-X-C chemokine, was induced only in infected C.CB mice at this time. This pattern of mRNA expression was maintained at 14 days p.i., with IFN-γ and IL-12p40 mRNAs being more intensively induced in the infected C.CB mice, but TNF-α mRNA was no longer induced. The higher recruitment of neutrophils observed in the spleens of infected C.CB mice could explain the temporary susceptibility of C.CB mice to B. melitensis infection. In contrast to infections with Salmonella, Leishmania, and Mycobacterium, the expression of the Nramp1 gene
Bechtol, D; Carpenter, L R; Mosites, E; Smalley, D; Dunn, J R
Brucellosis is a common zoonotic disease worldwide; however, few cases are reported in the US. Brucella melitensis infections are primarily acquired via consumption of high-risk foods or travel to endemic areas. We describe a case of B. melitensis infection in a Tennessee soldier following deployment in Iraq. Initial symptoms included knee and back pain. Culture of an aspirate of the left sacroiliac joint yielded B. melitensis. Genetic analysis indicated that this isolate came from the Middle East. Investigation of laboratory workers identified risky exposures and positive serology prompting post-exposure prophylaxis. Military personnel and other travellers should be advised to reduce risk regarding food consumption and animal contact in endemic areas. Additionally, medical providers should remain vigilant for non-endemic zoonoses among recent travellers.
López, A; Hitos, F; Pérez, A; Navarro-Fierro, R R
Considering the poor facilities available for microbiological diagnosis in some countries where Brucella abortus is a frequent cause of bovine abortion, a study was conducted to determine if isolation of B. abortus from an aborted bovine fetus could be predicted from a detailed histological study of the formalized lung. Thirty-nine samples of B. abortus positive and 20 negative fetal samples were examined for the presence of 14 different pulmonary lesions. Differences in the frequency of observed lesions between the positive and negative groups, were determined by odds ratios and chi square statistic. The confidence of the prediction was calculated by means of the logistic computer model. The frequency of eight lung lesions was found to be significantly (p less than 0.05) different between the groups; nevertheless, these lesions were not specific enough to be able to incriminate B. abortus as the cause of abortion. PMID:6434166
Recurrent spillover of Brucella abortus from wildlife reservoirs to domestic cattle in the Greater Yellowstone Area (GYA) has prevented the United States from completely eradicating bovine brucellosis. Risks to cattle are a function of the size and location of wildlife and livestock populations, the degree and nature of spatio-temporal interactions between the various hosts, the level of disease in wildlife, and the susceptibility of livestock herds. While the brucellosis prevalence in wild, free-ranging GYA bison (Bison bison) is high, current management actions have successfully limited contact between bison and cattle. Under current management practices, the risks to cattle in the GYA are predominantly from wild elk (Cervus elaphus). Intra- and inter-species transmission events, while uncommon, are nevertheless crucial for the maintenance of brucellosis in the GYA. Future management actions should focus on decreasing elk herd densities and group sizes and on understanding the behavioural and environmental drivers that result in co-mingling that makes transmission possible.
Kay, Gemma L.; Sergeant, Martin J.; Giuffra, Valentina; Bandiera, Pasquale; Milanese, Marco; Bramanti, Barbara
ABSTRACT Shotgun metagenomics provides a powerful assumption-free approach to the recovery of pathogen genomes from contemporary and historical material. We sequenced the metagenome of a calcified nodule from the skeleton of a 14th-century middle-aged male excavated from the medieval Sardinian settlement of Geridu. We obtained 6.5-fold coverage of a Brucella melitensis genome. Sequence reads from this genome showed signatures typical of ancient or aged DNA. Despite the relatively low coverage, we were able to use information from single-nucleotide polymorphisms to place the medieval pathogen genome within a clade of B. melitensis strains that included the well-studied Ether strain and two other recent Italian isolates. We confirmed this placement using information from deletions and IS711 insertions. We conclude that metagenomics stands ready to document past and present infections, shedding light on the emergence, evolution, and spread of microbial pathogens. PMID:25028426
Dorneles, Elaine M S; Teixeira-Carvalho, Andréa; Araújo, Márcio S S; Sriranganathan, Nammalwar; Lage, Andrey P
Brucella abortus live vaccines have been used successfully to control bovine brucellosis worldwide for decades. However, due to some limitations of these live vaccines, efforts are being made for the development of new safer and more effective vaccines that could also be used in other susceptible species. In this context, understanding the protective immune responses triggered by B. abortus is critical for the development of new vaccines. Such understandings will enhance our knowledge of the host/pathogen interactions and enable to develop methods to evaluate potential vaccines and innovative treatments for animals or humans. At present, almost all the knowledge regarding B. abortus specific immunological responses comes from studies in mice. Active participation of macrophages, dendritic cells, IFN-γ producing CD4(+) T-cells and cytotoxic CD8(+) T-cells are vital to overcome the infection. In this review, we discuss the characteristics of the immune responses triggered by vaccination versus infection by B. abortus, in different hosts.
Ben-Tekaya, Houchaima; Gorvel, Jean-Pierre; Dehio, Christoph
Bartonella spp. and Brucella spp. are closely related α-proteobacterial pathogens that by distinct stealth-attack strategies cause chronic infections in mammals including humans. Human infections manifest by a broad spectrum of clinical symptoms, ranging from mild to fatal disease. Both pathogens establish intracellular replication niches and subvert diverse pathways of the host's immune system. Several virulence factors allow them to adhere to, invade, proliferate, and persist within various host-cell types. In particular, type IV secretion systems (T4SS) represent essential virulence factors that transfer effector proteins tailored to recruit host components and modulate cellular processes to the benefit of the bacterial intruders. This article puts the remarkable features of these two pathogens into perspective, highlighting the mechanisms they use to hijack signaling and trafficking pathways of the host as the basis for their stealthy infection strategies.
Wang, Liping; Zhang, Yuanshu
The postantibiotic effects (PAEs) and postantibiotic sub-MIC effects (PA SMEs) of tilmicosin, erythromycin and tiamulin on erythromycin-susceptible and erythromycin-resistant strains of Streptococcus suis (M phenotype) were investigated in vitro. Tilmicosin and tiamulin induced significantly longer PAE and PA SME against both erythromycin-susceptible and erythromycin-resistant strains than did erythromycin. The durations of PAE and PA SMEs were proportional to the concentrations of drugs used for exposure. The PA SMEs were substantially longer than PAEs on S. suis (P<0.05) regardless of the antimicrobial used for exposure. The results indicated that the PAE and PA SME could help in the design of efficient control strategies for infection especially caused by erythromycin-resistant S. suis and that they may provide additional valuable information for the rational drug use in clinical practice.
Kay, Gemma L; Sergeant, Martin J; Giuffra, Valentina; Bandiera, Pasquale; Milanese, Marco; Bramanti, Barbara; Bianucci, Raffaella; Pallen, Mark J
Shotgun metagenomics provides a powerful assumption-free approach to the recovery of pathogen genomes from contemporary and historical material. We sequenced the metagenome of a calcified nodule from the skeleton of a 14th-century middle-aged male excavated from the medieval Sardinian settlement of Geridu. We obtained 6.5-fold coverage of a Brucella melitensis genome. Sequence reads from this genome showed signatures typical of ancient or aged DNA. Despite the relatively low coverage, we were able to use information from single-nucleotide polymorphisms to place the medieval pathogen genome within a clade of B. melitensis strains that included the well-studied Ether strain and two other recent Italian isolates. We confirmed this placement using information from deletions and IS711 insertions. We conclude that metagenomics stands ready to document past and present infections, shedding light on the emergence, evolution, and spread of microbial pathogens. Importance: Infectious diseases have shaped human populations and societies throughout history. The recovery of pathogen DNA sequences from human remains provides an opportunity to identify and characterize the causes of individual and epidemic infections. By sequencing DNA extracted from medieval human remains through shotgun metagenomics, without target-specific capture or amplification, we have obtained a draft genome sequence of an ~700-year-old Brucella melitensis strain. Using a variety of bioinformatic approaches, we have shown that this historical strain is most closely related to recent strains isolated from Italy, confirming the continuity of this zoonotic infection, and even a specific lineage, in the Mediterranean region over the centuries.
Ju, Cun-Xiang; Gu, Hong-Wei
Streptococcus suis serotype 2 (S. suis 2) is an important swine and human pathogen responsible for septicemia and meningitis. A novel gene, designated atl and encoding a major autolysin of S. suis 2 virulent strain HA9801, was identified and characterized in this study. The Atl protein contains 1,025 amino acids with a predicted molecular mass of 113 kDa and has a conserved N-acetylmuramoyl-l-alanine amidase domain. Recombinant Atl was expressed in Escherichia coli, and its bacteriolytic and fibronectin-binding activities were confirmed by zymography and Western affinity blotting. Two bacteriolytic bands were shown in the sodium dodecyl sulfate extracts of HA9801, while both were absent from the atl inactivated mutant. Cell chains of the mutant strain became longer than that of the parental strain. In the autolysis assay, HA9801 decreased to 20% of the initial optical density (OD) value, while the mutant strain had almost no autolytic activity. The biofilm capacity of the atl mutant was reduced ∼30% compared to the parental strain. In the zebrafish infection model, the 50% lethal dose of the mutant strain was increased up to 5-fold. Furthermore, the adherence to HEp-2 cells of the atl mutant was 50% less than that of the parental strain. Based on the functional analysis of the recombinant Atl and observed effects of atl inactivation on HA9801, we conclude that Atl is a major autolysin of HA9801. It takes part in cell autolysis, separation of daughter cells, biofilm formation, fibronectin-binding activity, cell adhesion, and pathogenesis of HA9801. PMID:22228730
Seol, B; Kelneric, Z; Hajsig, D; Madic, J; Naglic, T
The minimal inhibitory concentrations (MICs) for thirty-three epidemiologicaly unrelated clinical isolates of Streptococcus suis capsular type 2 were determined in relation to ampicillin, ampicillin-sulbactam, amoxicillin, clavulanate-amoxicillin, penicillin G, cephalexin, gentamicin, streptomycin, erythromycin, tylosin and doxycycline, using the microtitre broth dilution procedure described by the U.S. National Committee for Clinical Laboratory Standards (NCCLS). Gentamicin was the most active compound tested, with an MIC for 90% of the strains tested (MIC(90)) of 0.4 mg/L. Overall, 70% of strains were resistant to doxycycline (MIC(90) > or = 100.0 mg/L), followed by penicillin G (51% of strains) (MIC(90) + or = 100.0 mg/L). Resistance to amoxicillin and ampicillin was 36.4% (MIC(90) 12.5 mg/L) and 33.3% (MIC(90) 50.0 mg/L), respectively. 15.2% of S. suis strains were resistant to streptomycin, tylosin and cephalexin with MIC90 values of 25.0 mg/L, 12.5 mg/L and 25.0 mg/L, respectively. A combination of ampicillin and sulbactam (MIC(90) 6.3 mg/L) and a combination of amoxicillin and clavulanate (MIC(90) 3.1 mg/L) as well as erythromycin (1.6 mg/L) were of the same efficacy, with a total of 9.1% resistant S. suis strains. This high percentage of resistance to doxycycline and penicillin G precludes the use of these antibiotics as empiric therapy of swine diseases.
Takeuchi, Dan; Kerdsin, Anusak; Pienpringam, Anupong; Loetthong, Phacharaphan; Samerchea, Sutit; Luangsuk, Pakkinee; Khamisara, Kasean; Wongwan, Nithita; Areeratana, Prasanee; Chiranairadul, Piphat; Lertchayanti, Suwat; Petcharat, Sininat; Yowang, Amara; Chaiwongsaen, Phanupong; Nakayama, Tatsuya; Akeda, Yukihiro; Hamada, Shigeyuki; Sawanpanyalert, Pathom; Dejsirilert, Surang; Oishi, Kazunori
Background Streptococcus suis infection in humans has received increasing worldwide recognition. Methods and Findings A prospective study of S. suis infection in humans was conducted in Phayao Province in northern Thailand to determine the incidence and the risk behaviors of the disease in this region in 2010. Thirty-one cases were confirmed. The case fatality rate was 16.1%, and the estimated incidence rate was 6.2 per 100,000 in the general population. The peak incidence occurred in May. The median age of the patients was 53 years and 64.5% were men. Consumption of raw pork products was confirmed in 22 cases and the median incubation period (range) was 2 days (0–11) after consumption of raw pork products. Isolates from 31 patients were confirmed as serotype 2 in 23 patients (74.2%) and serotype 14 in eight patients (25.8%). The major sequence types (STs) were ST1 (n = 20) for serotype 2 and ST105 (n = 8) for serotype 14. The epidemiological analysis suggested three possible clusters, which included 17 cases. In the largest possible cluster of 10 cases in Chiang Kham and its neighboring districts in May, the source of infection in four cases was identified as a raw pork dish served at the same restaurant in this district. Microbiological analysis confirmed that three of four cases associated with consumption of raw pork at this restaurant were attributable to an identical strain of serotype 2 with ST1 and pulsotype A2. Conclusions Our data suggest a high incidence rate of S. suis infection in the general population in Phayao Province in 2010 and confirm a cluster of three cases in 31 human cases. Food safety control should be strengthened especially for raw pork products in northern Thailand. PMID:22363601
Bojarska, A; Molska, E; Janas, K; Skoczyńska, A; Stefaniuk, E; Hryniewicz, W; Sadowy, E
The purpose of this study was to perform an analysis of Streptococcus suis human invasive isolates, collected in Poland by the National Reference Centre for Bacterial Meningitis. Isolates obtained from 21 patients during 2000-2013 were investigated by phenotypic tests, multilocus sequence typing (MLST), analysis of the TR9 locus from the multilocus variable number tandem repeat (VNTR) analysis (MLVA) scheme and pulsed-field gel electrophoresis (PFGE) of SmaI-digested DNA. Determinants of virulence and antimicrobial resistance were detected by polymerase chain reaction (PCR) and analysed by sequencing. All isolates represented sequence type 1 (ST1) and were suggested to be serotype 2. PFGE and analysis of the TR9 locus allowed the discrimination of four and 17 types, respectively. Most of the isolates were haemolysis- and DNase-positive, and around half of them formed biofilm. Genes encoding suilysin, extracellular protein factor, fibronectin-binding protein, muramidase-released protein, surface antigen one, enolase, serum opacity factor and pili were ubiquitous in the studied group, while none of the isolates carried sequences characteristic for the 89K pathogenicity island. All isolates were susceptible to penicillin, cefotaxime, imipenem, moxifloxacin, chloramphenicol, rifampicin, gentamicin, linezolid, vancomycin and daptomycin. Five isolates (24 %) were concomitantly non-susceptible to erythromycin, clindamycin and tetracycline, and harboured the tet(O) and erm(B) genes; for one isolate, lsa(E) and lnu(B) were additionally detected. Streptococcus suis isolated in Poland from human invasive infections belongs to a globally distributed clonal complex of this pathogen, enriched in virulence markers. This is the first report of the lsa(E) and lnu(B) resistance genes in S. suis.
Zhu, Hong; He, Jun; Jing, Hong-bo; Wang, Zheng-qiang; Duan, Qing
Streptococcus suis serotype 2 (SS2) is a major pathogen frequently associated with infections in pigs. There are presently 35 serotypes of S.suis (serotype 1 to 34 and serotype 1/2) recognized on the basis of capsular antigens. Few people were reported to infect with SS2 in the past years. However, an accidental case happened in Sichuan province of China in 2005. Some people got ill and died, and all of them were closely contacted with sick pigs. Based on clinical features and epidemiologic data, this case could be caused by SS2 infection. Liver, spleen, kidney, lung and serum samples were collected and used for pathogen isolation and identification in laboratory, three strain bacteria were isolated. The three strains of SS2 showed typical morphology of SS2 on blood agar and under microscope with Gram stain. They were also agglutinated with standard serum of SS2. Biochemical characteristics of the three bacteria were tested using API 20 strep and analyzed by API software (version 3.3), results showed they were SS2. Four pairs of primer were designed, which were exactly matched the extracellular factor gene, muraminidase released protein gene, capsular polysaccharides gene and 16S rRNA gene respectively. These primers were used on polymerase chain reaction (PCR), and the PCR products were 626bp, 885bp, 487bp and 297bp on agarose gel, respectively. Drug sensitivity test were also done and results showed that they were sensitive to cefazolin, clindamycin, erythromycin, levofloxacin, nitrofurantoin, penicillin-G, and vancomycin and resistive to tetracycline. Balb/c mice infected with the isolated SS2 strain showed swelling in stomach and intestine, cyanochroia at mouth and suggillation under skin, which were similar to the clinical features of patients. Streptococcus suis serotype 2 were also found on lung sheeting sample under microscope with Gram stain. Rabbits infected with the isolated SS2 showed the similar clinical features with mice.
Calzas, Cynthia; Shiao, Tze Chieh; Neubauer, Axel; Kempker, Jennifer; Roy, René; Gottschalk, Marcelo
Streptococcus suis serotype 2 is an encapsulated bacterium and one of the most important bacterial pathogens in the porcine industry. Despite decades of research for an efficient vaccine, none is currently available. Based on the success achieved with other encapsulated pathogens, a glycoconjugate vaccine strategy was selected to elicit opsonizing anti-capsular polysaccharide (anti-CPS) IgG antibodies. In this work, glycoconjugate prototypes were prepared by coupling S. suis type 2 CPS to tetanus toxoid, and the immunological features of the postconjugation preparations were evaluated in vivo. In mice, experiments evaluating three different adjuvants showed that CpG oligodeoxyribonucleotide (ODN) induces very low levels of anti-CPS IgM antibodies, while the emulsifying adjuvants Stimune and TiterMax Gold both induced high levels of IgGs and IgM. Dose-response trials comparing free CPS with the conjugate vaccine showed that free CPS is nonimmunogenic independently of the dose used, while 25 μg of the conjugate preparation was optimal in inducing high levels of anti-CPS IgGs postboost. With an opsonophagocytosis assay using murine whole blood, sera from immunized mice showed functional activity. Finally, the conjugate vaccine showed immunogenicity and induced protection in a swine challenge model. When conjugated and administered with emulsifying adjuvants, S. suis type 2 CPS is able to induce potent IgM and isotype-switched IgGs in mice and pigs, yielding functional activity in vitro and protection against a lethal challenge in vivo, all features of a T cell-dependent response. This study represents a proof of concept for the potential of glycoconjugate vaccines in veterinary medicine applications against invasive bacterial infections. PMID:27113360
Background Streptococcus suis is an emerging zoonotic pathogen and is the leading cause of bacterial meningitis in adults in Vietnam. Systematic data on the antimicrobial susceptibility profiles of S. suis strains isolated from human cases are lacking. We studied antimicrobial resistance and associated resistance determinants in S. suis isolated from patients with meningitis in southern Vietnam. Methods S. suis strains isolated between 1997 and 2008 were investigated for their susceptibility to six antimicrobial agents. Strains were screened for the presence and expression of tetracycline and erythromycin resistance determinants and the association of tet(M) genes with Tn916- like transposons. The localization of tetracycline resistance gene tet(L) was determined by pulse field gel electrophoresis and Southern blotting. Results We observed a significant increase in resistance to tetracycline and chloramphenicol, which was concurrent with an increase in multi-drug resistance. In tetracycline resistance strains, we identified tet(M), tet(O), tet(W) and tet(L) and confirmed their expression. All tet(M) genes were associated with a Tn916-like transposon. The co-expression of tet(L) and other tetracycline resistance gene(s) encoding for ribosomal protection protein(s) was only detected in strains with a minimum inhibitory concentration (MIC) of tetracycline of ≥ 64 mg/L Conclusions We demonstrated that multi-drug resistance in S. suis causing disease in humans in southern Vietnam has increased over the 11-year period studied. We report the presence and expression of tet(L) in S. suis strains and our data suggest that co-expression of multiple genes encoding distinct mechanism is required for an MIC ≥ 64 mg/L to tetracycline. PMID:21208459
Nan, Wenlong; Zhang, Yueyong; Tan, Pengfei; Xu, Zouliang; Chen, Yuqi; Mao, Kairong; Chen, Yiping
Brucellosis is a widespread zoonotic disease caused by Brucella spp. Immunization with attenuated vaccines has proved to be an effective method of prevention; however, it may also interfere with diagnosis. Brucella abortus strain A19, which is homologous to B. abortus strain S19, is widely used for the prevention of bovine brucellosis in China. For effective monitoring of the control of brucellosis, it is essential to distinguish A19 from field strains. Single-nucleotide polymorphism-based assays offer a new approach to such discrimination studies. In the current study, we developed a cycleave PCR assay that successfully distinguished attenuated vaccine strains A19 and S19 from 22 strains of B. abortus and 57 strains of 5 other Brucella species. The assay gave a negative reaction with 4 non-Brucella species. The minimum sensitivity of the assay, evaluated using 10-fold dilutions of chromosomal DNA, was 7.6 fg for the A19 strain and 220 fg for the single non-A19/non-S19 Brucella strain tested (B. abortus 104M). The assay was also reproducible (intra- and interassay coefficients of variation: 0.003-0.01 and 0.004-0.025, respectively). The cycleave assay gave an A19/S19-specific reaction in 3 out of 125 field serum samples, with the same 3 samples being positive in an alternative A19/S19-specific molecular assay. The cycleave assay gave a total of 102 Brucella-specific reactions (3 being the A19/S19-specific reactions), whereas an alternative Brucella-specific assay gave 92 positive reactions (all also positive in the cycleave assay). Therefore, this assay represents a simple, rapid, sensitive, and specific tool for use in brucellosis control.
Meisel, Susann; Stöckel, Stephan; Elschner, Mandy; Melzer, Falk; Rösch, Petra; Popp, Jürgen
Detection of Brucella, causing brucellosis, is very challenging, since the applied techniques are mostly time-demanding and not standardized. While the common detection system relies on the cultivation of the bacteria, further classical typing up to the biotype level is mostly based on phenotypic or genotypic characteristics. The results of genotyping do not always fit the existing taxonomy, and misidentifications between genetically closely related genera cannot be avoided. This situation gets even worse, when detection from complex matrices, such as milk, is necessary. For these reasons, the availability of a method that allows early and reliable identification of possible Brucella isolates for both clinical and epidemiological reasons would be extremely useful. We evaluated micro-Raman spectroscopy in combination with chemometric analysis to identify Brucella from agar plates and directly from milk: prior to these studies, the samples were inactivated via formaldehyde treatment to ensure a higher working safety. The single-cell Raman spectra of different Brucella, Escherichia, Ochrobactrum, Pseudomonas, and Yersinia spp. were measured to create two independent databases for detection in media and milk. Identification accuracies of 92% for Brucella from medium and 94% for Brucella from milk were obtained while analyzing the single-cell Raman spectra via support vector machine. Even the identification of the other genera yielded sufficient results, with accuracies of >90%. In summary, micro-Raman spectroscopy is a promising alternative for detecting Brucella. The measurements we performed at the single-cell level thus allow fast identification within a few hours without a demanding process for sample preparation.
Huang, Kaisong; Zhang, Qiang; Song, Yajing; Zhang, Zhewen; Zhang, Anding; Xiao, Jingfa
Spectinomycin is an aminocyclitol antibiotic used clinically to treat a variety of infections in animals. Here, we characterized drug resistance prevalence in clinical Streptococcus suis isolates and discovered a novel resistance mechanism in which the s5 mutation (Gly26Asp) results in high spectinomycin resistance. Additionally, a novel integrative and conjugative element encompassing a multidrug resistance spw_like-aadE-lnu(B)-lsa(E) cluster and a cadmium resistance operon were identified, suggesting a possible cause for the wide dissemination of spectinomycin resistance in S. suis. PMID:27458226
Vaillancourt, Katy; LeBel, Geneviève; Frenette, Michel; Fittipaldi, Nahuel; Gottschalk, Marcelo; Grenier, Daniel
Bacteriocins are antimicrobial peptides of bacterial origin that are considered as a promising alternative to the use of conventional antibiotics. Recently, our laboratory reported the purification and characterization of two lantibiotics, suicin 90-1330 and suicin 3908, produced by the swine pathogen and zoonotic agent Streptococcus suis (serotype 2). In this study, a novel bacteriocin produced by S. suis has been identified and characterized. The producing strain S. suis 65 (serotype 2) was found to belong to the sequence type 28, that includes strains known to be weakly or avirulent in a mouse model. The bacteriocin, whose production was only possible following growth on solid culture medium, was purified to homogeneity by cationic exchange and reversed-phase high-pressure liquid chromatography. The bacteriocin, named suicin 65, was heat, pH and protease resistant. Suicin 65 was active against all S. suis isolates tested, including antibiotic resistant strains. Amino acid sequencing of the purified bacteriocin by Edman degradation revealed the presence of modified amino acids suggesting a lantibiotic. Using the partial sequence obtained, a blast was performed against published genomes of S. suis and allowed to identify a putative lantibiotic locus in the genome of S. suis 89-1591. From this genome, primers were designed and the gene cluster involved in the production of suicin 65 by S. suis 65 was amplified by PCR. Sequence analysis revealed the presence of ten open reading frames, including a duplicate of the structural gene. The structural genes (sssA and sssA') of suicin 65 encodes a 25-amino acid residue leader peptide and a 26-amino acid residue mature peptide yielding an active bacteriocin with a deducted molecular mass of 3,005 Da. Mature suicin 65 showed a high degree of identity with class I type B lantibiotics (globular structure) produced by Streptococcus pyogenes (streptococcin FF22; 84.6%), Streptococcus macedonicus (macedocin ACA-DC 198; 84
L'vov, V L; Malikov, V E; Shashkov, A S; Dranovskaia, E A; Dmitriev, B A
The phenol-phase soluble antigenic lipopolysaccharide was isolated from Brucella melitensis, strain 565, by the routine phenol/water procedure followed by chromatography on Sepharose 4B. After mild acid hydrolysis and chromatography on Sephadex G-50, the lipopolysaccharide yielded a linear O-specific polysaccharide built up from 1,2-linked 4,6-dideoxy-4-formamido-alpha-D-mannopyranosyl units. The structure of the polysaccharide was deduced mainly from the nuclear magnetic resonance and methylation analyses. The phenol-soluble lipopolysaccharide, isolated from commercial vaccine strain B. abortus 19-BA, on mild hydrolysis afforded material, 13C and 1H-NMR spectra of which were identical to those of the O-specific polysaccharide from B. melitensis 565.
Wareth, Gamal; Eravci, Murat; Weise, Christoph; Roesler, Uwe; Melzer, Falk; Sprague, Lisa D; Neubauer, Heinrich; Murugaiyan, Jayaseelan
Brucellosis is a debilitating zoonotic disease that affects humans and animals. The diagnosis of brucellosis is challenging, as accurate species level identification is not possible with any of the currently available serology-based diagnostic methods. The present study aimed at identifying Brucella (B.) species-specific proteins from the closely related species B. abortus and B. melitensis using sera collected from naturally infected host species. Unlike earlier reported investigations with either laboratory-grown species or vaccine strains, in the present study, field strains were utilized for analysis. The label-free quantitative proteomic analysis of the naturally isolated strains of these two closely related species revealed 402 differentially expressed proteins, among which 63 and 103 proteins were found exclusively in the whole cell extracts of B. abortus and B. melitensis field strains, respectively. The sera from four different naturally infected host species, i.e., cattle, buffalo, sheep, and goat were applied to identify the immune-binding protein spots present in the whole protein extracts from the isolated B. abortus and B. melitensis field strains and resolved on two-dimensional gel electrophoresis. Comprehensive analysis revealed that 25 proteins of B. abortus and 20 proteins of B. melitensis were distinctly immunoreactive. Dihydrodipicolinate synthase, glyceraldehyde-3-phosphate dehydrogenase and lactate/malate dehydrogenase from B. abortus, amino acid ABC transporter substrate-binding protein from B. melitensis and fumarylacetoacetate hydrolase from both species were reactive with the sera of all the tested naturally infected host species. The identified proteins could be used for the design of serological assays capable of detecting pan-Brucella, B. abortus- and B. melitensis-specific antibodies.
Wareth, Gamal; Eravci, Murat; Weise, Christoph; Roesler, Uwe; Melzer, Falk; Sprague, Lisa D.; Neubauer, Heinrich; Murugaiyan, Jayaseelan
Brucellosis is a debilitating zoonotic disease that affects humans and animals. The diagnosis of brucellosis is challenging, as accurate species level identification is not possible with any of the currently available serology-based diagnostic methods. The present study aimed at identifying Brucella (B.) species-specific proteins from the closely related species B. abortus and B. melitensis using sera collected from naturally infected host species. Unlike earlier reported investigations with either laboratory-grown species or vaccine strains, in the present study, field strains were utilized for analysis. The label-free quantitative proteomic analysis of the naturally isolated strains of these two closely related species revealed 402 differentially expressed proteins, among which 63 and 103 proteins were found exclusively in the whole cell extracts of B. abortus and B. melitensis field strains, respectively. The sera from four different naturally infected host species, i.e., cattle, buffalo, sheep, and goat were applied to identify the immune-binding protein spots present in the whole protein extracts from the isolated B. abortus and B. melitensis field strains and resolved on two-dimensional gel electrophoresis. Comprehensive analysis revealed that 25 proteins of B. abortus and 20 proteins of B. melitensis were distinctly immunoreactive. Dihydrodipicolinate synthase, glyceraldehyde-3-phosphate dehydrogenase and lactate/malate dehydrogenase from B. abortus, amino acid ABC transporter substrate-binding protein from B. melitensis and fumarylacetoacetate hydrolase from both species were reactive with the sera of all the tested naturally infected host species. The identified proteins could be used for the design of serological assays capable of detecting pan-Brucella, B. abortus- and B. melitensis-specific antibodies. PMID:27144565
Boraker, D K; Stinebring, W R; Kunkel, J R
An indirect enzyme-antibody immunosorbent assay (BrucELISA) is described for the detection of antibody to Brucella abortus in cow's milk. Three series of milk samples were obtained from an adult-vaccinated dairy herd infected with B. abortus. The BrucELISA system was used as a screening test for individual milks diluted 1:200 (BE 200 test), for undiluted bulk milks, and to determine antibody titer (BrucELISA titration assay). The BrucELISA results correlated highly with positive Brucella ring test reactions and culture positivity, eliminated false-positive Brucella ring test reactions, detected antibody in some samples which were Brucella ring test negative, and distinguished between vaccinated and infected animals. BrucELISA titration assay titers of greater than 1:800 were correlated with shedding, or were prognostic for animals which eventually became shedders. Binding of the enzyme-antibody conjugate to bovine immunoglobulin in the absence of rabbit anti-bovine immunoglobulin occurred with culture-positive or -negative milks showing titers of greater than 1:1,600 (the beta effect); the effect was also of predictive value in identifying eventual shedders. The BrucELISA system is a sensitive, specific, and inexpensive method for screening large numbers of individual or bulk milk samples for the presence of antibody to B. abortus. PMID:6793622
Vaccination of elk (Cervus canadensis) with Brucella abortus strain RB51 overexpressing superoxide dismutase and glycosyltransferase genes does not induce adequate protection against experimental brucella abortus challenge
In recent years, elk (Cervus canadensis) have been implicated as the source of Brucella abortus infection for numerous cattle herds in the Greater Yellowstone Area (GYA). In the face of environmental and ecological changes on the landscape, the range of infected elk is expanding. Consequently, the d...
Liu, Qianhong; Liu, Xingyu; Yan, Feng; He, Yuhua; Wei, Jie; Zhang, Yuanyuan; Liu, Lu; Sun, Youpeng
Brucella melitensis, encounters a very stressful environment in phagosomes, especially low pH levels. So identifying the genes that contribute to the replication and survival within an acidic environment is critical in understanding the pathogenesis of the Brucella bacteria. In our research, comparative transcriptome with RNA-seq were used to analyze the changes of genes in normal-medium culture and in pH4.4-medium culture. The results reveal that 113 genes expressed with significant differences (|log2Ratio| ≥ 3); about 44% genes expressed as up-regulated. With GO term analysis, structural constituent of the ribosome, rRNA binding, structural molecule activity, and cation-transporting ATPase activity were significantly enriched (p-value ≤ 0.05). These genes distributed in 51 pathways, in which ribosome and photosynthesis pathways were significantly enriched. Six pathways (oxidative phosphorylation, iron-transporting, bacterial secretion system, transcriptional regulation, two-component system, and ABC transporters pathways) tightly related to the intracellular survival and virulence of Brucella were analyzed. A two-component response regulator gene in the transcriptional regulation pathway, identified through gene deletion and complementary technologies, played an important role in the resistance to the acid-resistance and virulence of Brucella.
Abe, Erika; Ohishi, Kazue; Ishinazaka, Tsuyoshi; Fujii, Ke; Maruyama, Tadashi
Brucella infection in Hokkaido was serologically surveyed in four species of pinnipeds inhabiting Cape Erimo during 2008-2013 and the Shiretoko Peninsula in 1999, by enzyme-linked immunosorbent assay using Brucella abortus and B. canis as antigens. Anti-Brucella positive sera showed higher absorbance to B. abortus than B. canis in almost all samples. Anti-B. abortus antibodies were detected in serum samples from 24% (n=55) of Western Pacific harbor seals (Phoca vitulina stejnegeri) in Cape Erimo, and from 66% (n=41) of spotted seals (P. largha), 15% (n=20) of ribbon seals (Histriophoca fasciata) and 18% (n=17) of Western Steller's sea lions (Eumetopias jubatus jubatus) in the Shiretoko Peninsula. In the harbor seals, anti-Brucella antibodies were detected at higher absorbance in 1- to 4-year-old individuals than in pups and mature animals, suggesting either that the Brucella infection mainly occurred after weaning, or that it is maternally transmitted to the pups with premature or suppressed immunity. In the spotted seals and ribbon seals, anti-Brucella antibodies were detected in both immature and mature animals, with higher absorbance in the former. In the Western Steller's sea lions, the antibodies were detected only in mature animals. Western blot analysis of the serum samples showed some differences in band appearances, i.e. discrete or smeary, and in the number of bands. These indicate that multiple different Brucella may be prevalent in pinnipeds in Hokkaido. Or the Brucella of pinnipeds may have some intra-species diversity.
Karadeniz, İlknur; Hur, Junguk; He, Yongqun; Özgür, Arzucan
Brucella is an intracellular bacterium that causes chronic brucellosis in humans and various mammals. The identification of host-Brucella interaction is crucial to understand host immunity against Brucella infection and Brucella pathogenesis against host immune responses. Most of the information about the inter-species interactions between host and Brucella genes is only available in the text of the scientific publications. Many text-mining systems for extracting gene and protein interactions have been proposed. However, only a few of them have been designed by considering the peculiarities of host–pathogen interactions. In this paper, we used a text mining approach for extracting host-Brucella gene–gene interactions from the abstracts of articles in PubMed. The gene–gene interactions here represent the interactions between genes and/or gene products (e.g., proteins). The SciMiner tool, originally designed for detecting mammalian gene/protein names in text, was extended to identify host and Brucella gene/protein names in the abstracts. Next, sentence-level and abstract-level co-occurrence based approaches, as well as sentence-level machine learning based methods, originally designed for extracting intra-species gene interactions, were utilized to extract the interactions among the identified host and Brucella genes. The extracted interactions were manually evaluated. A total of 46 host-Brucella gene interactions were identified and represented as an interaction network. Twenty four of these interactions were identified from sentence-level processing. Twenty two additional interactions were identified when abstract-level processing was performed. The Interaction Network Ontology (INO) was used to represent the identified interaction types at a hierarchical ontology structure. Ontological modeling of specific gene–gene interactions demonstrates that host–pathogen gene–gene interactions occur at experimental conditions which can be ontologically
Karadeniz, İlknur; Hur, Junguk; He, Yongqun; Özgür, Arzucan
Brucella is an intracellular bacterium that causes chronic brucellosis in humans and various mammals. The identification of host-Brucella interaction is crucial to understand host immunity against Brucella infection and Brucella pathogenesis against host immune responses. Most of the information about the inter-species interactions between host and Brucella genes is only available in the text of the scientific publications. Many text-mining systems for extracting gene and protein interactions have been proposed. However, only a few of them have been designed by considering the peculiarities of host-pathogen interactions. In this paper, we used a text mining approach for extracting host-Brucella gene-gene interactions from the abstracts of articles in PubMed. The gene-gene interactions here represent the interactions between genes and/or gene products (e.g., proteins). The SciMiner tool, originally designed for detecting mammalian gene/protein names in text, was extended to identify host and Brucella gene/protein names in the abstracts. Next, sentence-level and abstract-level co-occurrence based approaches, as well as sentence-level machine learning based methods, originally designed for extracting intra-species gene interactions, were utilized to extract the interactions among the identified host and Brucella genes. The extracted interactions were manually evaluated. A total of 46 host-Brucella gene interactions were identified and represented as an interaction network. Twenty four of these interactions were identified from sentence-level processing. Twenty two additional interactions were identified when abstract-level processing was performed. The Interaction Network Ontology (INO) was used to represent the identified interaction types at a hierarchical ontology structure. Ontological modeling of specific gene-gene interactions demonstrates that host-pathogen gene-gene interactions occur at experimental conditions which can be ontologically represented. Our
Jouvin, Marie-Hélène; Kinet, Jean-Pierre
The hygiene hypothesis, which was put forward more than 20 years ago by Strachan, proposes that the recent increase in allergic and autoimmune diseases is due to increasing hygiene standards. Since then, numerous epidemiologic and animal studies have provided support for this hypothesis and showed that certain microorganisms, helminths in particular, have immunomodulatory effects. More recently, studies have led to the identification of some of the mechanisms underlying these immunomodulatory effects. Substances, or crude extracts, produced by worms and responsible for these effects have been analyzed. Clinical trials have been performed mainly with pig whipworm, which was chosen because it is likely to be nonpathogenic in human subjects. Eggs of the pig whipworm (Trichuris suis ova) have been shown to be safe in multiple studies. Efficacy has been demonstrated in patients with inflammatory bowel diseases and in 1 case of pecan allergy. Altogether, this information supports further investigation of T suis ova in patients with immune-mediated diseases, particularly in areas in which there is currently no therapy, such as food allergy.
Blume, Verena; Luque, Inmaculada; Vela, Ana I; Borge, Carmen; Maldonado, Alfonso; Domínguez, Lucas; Tarradas, Carmen; Fernández-Garayzábal, José F
The aim of this study was to analyze the genetic characteristics and virulence phenotypes of Streptococcus suis, specifically, in clinical isolates of serotypes 2 and 9 (n = 195), obtained from diverse geographical areas across Spain. Pulsed-field gel electrophoresis (PFGE) typing identified 97 genetic profiles, 68% of which were represented by single isolates, indicative of a substantial genetic diversity among the S. suis isolates analyzed. Five PFGE profiles accounted for 33.3% of the isolates and were isolated from 38% of the herds in nine different provinces, indicative of the bacterium's widespread distribution in the Spanish swine population. Representative isolates of the most prevalent PFGE profiles of both serotypes were subjected to multilocus sequence typing (MLST) analysis. The results indicated that serotypes 2 and 9 have distinct genetic backgrounds. Serotype 2 isolates belong to the ST1 complex, a highly successful clone that has spread over most European countries. In accordance with isolates of this complex, most serotype 2 isolates also expressed the phenotype MRP(+)EF(+)SLY(+). Serotype 9 isolates belong to the ST61 complex, which is distantly related to the widespread European ST87 clone. Also, in contrast to most isolates of the European ST87 clone, which express the large variant MRP*, the majority of serotype 9 isolates (97.9%) did not express the protein.
Kerdsin, Anusak; Dejsirilert, Surang; Puangpatra, Parichart; Sripakdee, Saowalak; Chumla, Koranan; Boonkerd, Nitsara; Polwichai, Pitimol; Tanimura, Susumu; Takeuchi, Dan; Nakayama, Tatsuya; Nakamura, Shota; Akeda, Yukihiro; Gottschalk, Marcelo; Sawanpanyalert, Pathom
To examine associations between clinical features of Streptococcus suis serotype 2 infections in humans in Thailand and genotypic profiles of isolates, we conducted a retrospective study during 2006–2008. Of 165 patients for whom bacterial cultures of blood, cerebrospinal fluid, or both were positive for S. suis serotype 2, the major multilocus sequence types (STs) found were ST1 (62.4%) and ST104 (25.5%); the latter is unique to Thailand. Clinical features were examined for 158 patients. Infections were sporadic; case-fatality rate for adults was 9.5%, primarily in northern Thailand. Disease incidence peaked during the rainy season. Disease was classified as meningitis (58.9%) or nonmeningitis (41.1%, and included sepsis [35.4%] and others [5.7%]). Although ST1 strains were significantly associated with the meningitis category (p<0.0001), ST104 strains were significantly associated with the nonmeningitis category (p<0.0001). The ST1 and ST104 strains are capable of causing sepsis, but only the ST1 strains commonly cause meningitis. PMID:21529392
Megerlin, F; Fouassier, E; Lopert, R; Bourlioux, P
Responding to Smith et al. (Nature, 2014), this paper argues that for medical use, faecal microbiota transplantation (FMT) should be considered a sui generis biological drug, rather than a tissue. Smith and colleagues' thesis is based on possible undesirable economic consequences of this designation--not on its scientific and conceptual basis. The faecal transplant (including gut microbiota, metabolites, mucus, human cells, viruses, fungi, etc.) is not a tissue; it is of topographic--not cellular--human origin. We consider the donor a bioreactor, producing the faecal substrate of therapeutic interest. The debate is of singular importance as the FDA considers FMT a drug and released a new guidance for public consultation in February 2014, whereas to date the European Medicines Agency has not promulgated its position. The UK's National Institute for Heath and Care Excellence does not consider FMT to involve the transplantation of body tissue, and in March 2014 the French regulatory agency ANSM expressly declared it to be a drug. As FM is a complex and highly variable admixture, its components cannot be completely characterized, and to date, compositional quality cannot be assessed. We consider FMT to be a sui generis biologic drug, albeit one prepared with unconventional raw material under microbiologic control. The possibility of associating identified bacterial species with particular diseases and cultivating selected bacteria of therapeutic interest would certainly define a second generation of microbiome therapeutics, but is still speculative.
Li, Gen; Lu, Gejin; Qi, Zhimin; Li, Hongen; Wang, Lin; Wang, Yanhui; Liu, Bowen; Niu, Xiaodi; Deng, Xuming; Wang, Jianfeng
Streptococcus suis, a Gram-positive pathogen, is widely recognized as an important agent of swine infection, and it is also known to cause a variety of zoonoses, such as meningitis, polyarthritis and pneumonia. Suilysin (SLY), an extracellular pore-forming toxin that belongs to the cholesterol-dependent cytolysin family, is an essential virulence factor of S. suis capsular type 2 (SS2). Here, we found that morin hydrate (morin), a natural flavonoid that lacks anti-SS2 activity, inhibits the hemolytic activity of SLY, protects J774 cells from SS2-induced injury and protects mice from SS2 infection. Further, by molecular modeling and mutational analysis, we found that morin binds to the “stem” domain 2 in SLY and hinders its transformation from the monomer form to the oligomer form, which causes the loss of SLY activity. Our study demonstrates that morin hinders the cell lysis activity of SLY through a novel mechanism of interrupting the heptamer formation. These findings may lead to the development of promising therapeutic candidates for the treatment of SS2 infections. PMID:28373868
Wu, Y J
In the heyday of Chinese feudal society, women's status in the society of the Sui-Tang period was improved in the Tang Dynasty.The demand for female to stay young and anti-aging had attracted lots of attention in the society, thus providing a favorable social environment for the formation and development of Chinese herbal cosmetology. The important representative medical works on traditional Chinese medicine (TCM) were published in the Sui and Tang Dynasties, such as Bei ji qian jin yao fang (Essential Recipes for Emergent Use Worth A Thousand Gold), Qian jin yi fang (Supplement to Recipes Worth A Thousand Gold), Wai tai mi yao (Arcane Essentials from the Imperial Library) etc., all carry chapter(s) on Chinese herbal cosmetology. In the Tang Dynasty, beauty techniques became perfect, with rich exquisite make-up style. Make-up had become an integral part of daily life. Cosmetic surgery has reached a fairly high level, with a number of cosmetic surgeries appeared, such as the making of artificial dimples, artificial eyes, and dental cosmetic.
Radhakrishnan, Girish K; Splitter, Gary A
Toll/interleukin-1 like receptors are evolutionarily conserved proteins in eukaryotes that play crucial role in pathogen recognition and innate immune responses. Brucella are facultative intracellular bacterial pathogens causing brucellosis in animal and human hosts. Brucella behave as a stealthy pathogen by evading the immune recognition or suppressing the TLR signaling cascades. Brucella encode a TIR domain containing protein, TcpB, which suppresses NF-kappaB activation as well as pro-inflammatory cytokine secretion mediated by TLR2 and TLR4 receptors. TcpB targets the TIRAP mediated pathway to suppress TLR signaling. With the objective of detailed characterization, we have over expressed and purified TcpB from Brucella melitensis in native condition. The purified protein exhibited lipid-binding properties and cell permeability. NF-kappaB inhibition property of endogenous TcpB has also been demonstrated. The data provide insight into the mechanism of action of TcpB in the intracellular niche of Brucella.
Gamazo, Carlos; Lecároz, María Concepción; Prior, Sandra; Vitas, Ana Isabel; Campanero, Miguel Angel; Irache, Juan Manuel; Blanco-Prieto, María José
Brucellosis is a highly contagious bacterial zoonosis that affects millions of people worldwide. Brucella is highly infectious, especially when aerosolized. The infection induces severe protracted diseases, which are both debilitating and incapacitating, hence, Brucella melitensis has been considered a potential biological warfare agent. In the battle against Brucella, it is crucial to know its chemical-structure and biochemistry-metabolic characteristics. It is well known that Brucella, as well as many other intracellular bacterial pathogens, has evolved to survive and even proliferate within monocytes and macrophages cells. Depending on the route of entry (complement, Fc, lectin or fibronectin receptors), the fate of the bacteria will vary; it may even segregate from the endocytic route towards the endoplasmic reticulum. This intracellular "non regular" behaviour of Brucella makes treatment difficult. Most antibiotics, although effective in vitro, do not actively pass through cellular membranes, or, once inside, may not reach the discrete intracellular niche where the bacteria is hidden. Therefore, complete eradication of the microorganisms is difficult to achieve, and the incidence of relapses is rather high. Taking these data into consideration, this review will evaluate the past, current and new trends in the control of brucellosis, paying special attention to the drug delivery systems as potential vectors for targeting these intracellular sites where the organisms are located.
Denoel, P A; Vo, T K; Tibor, A; Weynants, V E; Trunde, J M; Dubray, G; Limet, J N; Letesson, J J
Monoclonal antibodies and polyclonal antisera recognizing a 39-kDa protein (P39) of brucellin, a cytoplasmic extract from Brucella melitensis rough strain B115, were produced. The P39 was purified by anion-exchange chromatography. Eleven of fourteen Brucella-infected cows whose infections had been detected by the delayed-type hypersensitivity (DTH) test with brucellergen also developed a DTH reaction when purified P39 was used as the trigger. The T-cell proliferative responses to P39 of peripheral blood lymphocytes from Brucella-infected cows were also positive. None of the animals infected with other bacterial species that are presumed to induce immunological cross-reactions with Brucella spp. reacted to P39, either in DTH tests or in lymphocyte proliferation assays. A lambda gt11 genomic library of Brucella abortus was screened with a monoclonal antibody specific for P39, and the gene coding for this protein was subsequently isolated. The nucleotide sequence of the P39 gene was determined, and the deduced amino acid sequence is in accordance with the sequence of an internal peptide isolated from P39. PMID:9009303
Mora-Cartín, Ricardo; Chacón-Díaz, Carlos; Gutiérrez-Jiménez, Cristina; Gurdián-Murillo, Stephany; Lomonte, Bruno; Chaves-Olarte, Esteban
Brucella abortus is an intracellular pathogen of monocytes, macrophages, dendritic cells, and placental trophoblasts. This bacterium causes a chronic disease in bovines and in humans. In these hosts, the bacterium also invades neutrophils; however, it fails to replicate and just resists the killing action of these leukocytes without inducing significant activation or neutrophilia. Moreover, B. abortus causes the premature cell death of human neutrophils. In the murine model, the bacterium is found within macrophages and dendritic cells at early times of infection but seldom in neutrophils. Based on this observation, we explored the interaction of mouse neutrophils with B. abortus. In contrast to human, dog, and bovine neutrophils, naive mouse neutrophils fail to recognize smooth B. abortus bacteria at early stages of infection. Murine normal serum components do not opsonize smooth Brucella strains, and neutrophil phagocytosis is achieved only after the appearance of antibodies. Alternatively, mouse normal serum is capable of opsonizing rough Brucella mutants. Despite this, neutrophils still fail to kill Brucella, and the bacterium induces cell death of murine leukocytes. In addition, mouse serum does not opsonize Yersinia enterocolitica O:9, a bacterium displaying the same surface polysaccharide antigen as smooth B. abortus. Therefore, the lack of murine serum opsonization and absence of murine neutrophil recognition are specific, and the molecules responsible for the Brucella camouflage are N-formyl-perosamine surface homopolysaccharides. Although the mouse is a valuable model for understanding the immunobiology of brucellosis, direct extrapolation from one animal system to another has to be undertaken with caution. PMID:27001541
Li, Zhi-Zhang; Gong, Fu-Chun; Shen, Guo-Li; Yu, Ru-Qin
A novel amperometric immunosensor setup is described which uses horseradish peroxidase (HRP) as a label in conjunction with a current-based Brucella sensor. The Bacteria modified immunosensor was constructed by using a biocomposite formed by dispersing graphite powder into a mixture of Brucella melitensis and silicate polymer gel. The enzyme-labeled antibody can readily diffuse toward the encapsulated antigen (Brucella melitensis), which retains its binding properties, and the association reaction is easily detected at the surface exposed to the solution. The use of an oaminophenol (o-AP) substrate and amperometric detection at -150 mV (vs. SCE) results in a relatively low detection limit of 3.5 ng/ml and a linear detection range of 3.5 ng/ml to 200 ng/ml. Based on an optimized parameter, the prepared sensor was used to detect the Brucella melitensis antibody in serum samples by using a competitive binding assay. The results demonstrate the feasibility of employing the proposed immunosensor for the detection for Brucella melitensis antibody in a clinical analysis.
Asmare, Kassahun; Krontveit, Randi I; Ayelet, Gelagay; Sibhat, Berhanu; Godfroid, Jacques; Skjerve, Eystein
This meta-analysis estimates a single-group summary (effect size) for seroprevalence of Brucella spp. exposure in dairy cattle of Ethiopia. It also attempts to identify study-level variables that could explain the variation in apparent seroprevalence. The literature search was restricted to studies published in English language from January 2000 to December 2013. A template was designed to retrieve the most biologically plausible and consistent variables from the articles. A total of 29 published papers containing 40 animal-level studies were used in the analyses. The single-group summary of Brucella seroprevalence in cattle was estimated to reach 3.3 % with 95 % confidence interval (CI) (2.6-4.2 %). Of all the variables considered, region was the only specific factor identified to explain about 20 % of between-study variation. Accordingly, the region-based meta-analysis forest plot revealed the highest prevalence in central Ethiopia followed by southern part. The lowest prevalence estimate was observed in the western part of the country. The visual inspection of the funnel plot demonstrated the presence of possible publication bias which might dictate shortage of studies with higher prevalences or variance inflation due to infectiousness of Brucella. In conclusion, the quantitative review showed the seroprevalence to be low but widely distributed. More importantly, the review underscores the need for isolation and characterization of the circulating Brucella spp. to capture the type of Brucella spp. involved and its distribution in cattle in Ethiopia.
De Santis, Riccardo; Ancora, Massimo; De Massis, Fabrizio; Ciammaruconi, Andrea; Zilli, Katiuscia; Di Giannatale, Elisabetta; Pittiglio, Valentina; Fillo, Silvia; Lista, Florigio
Brucellosis, one of the most important re-emerging zoonoses in many countries, is caused by bacteria belonging to the genus Brucella. Furthermore these bacteria represent potential biological warfare agents and the identification of species and biovars of field strains may be crucial for tracing back source of infection, allowing to discriminate naturally occurring outbreaks instead of bioterrorist events. In the last years, multiple-locus variable-number tandem repeat analysis (MLVA) has been proposed as complement of the classical biotyping methods and it has been applied for genotyping large collections of Brucella spp. At present, the MLVA band profiles may be resolved by automated or manual procedures. The Lab on a chip technology represents a valid alternative to standard genotyping techniques (as agarose gel electrophoresis) and it has been previously used for Brucella genotyping. Recently, a new high-throughput genotyping analysis system based on capillary gel electrophoresis, the QIAxcel, has been described. The aim of the study was to evaluate the ability of two DNA sizing equipments, the QIAxcel System and the Lab chip GX, to correctly call alleles at the sixteen loci including one frequently used MLVA assay for Brucella genotyping. The results confirmed that these technologies represent a meaningful advancement in high-throughput Brucella genotyping. Considering the accuracy required to confidently resolve loci discrimination, QIAxcel shows a better ability to measure VNTR allele sizes compared to LabChip GX.
This case-control study aimed at assessing the relative association of Neospora caninum and Brucella species exposure with reproductive disorders. The study was carried out between October 2011 and June 2012 on 731 dairy cows sampled from 150 dairy farms in selected 17 conurbations of Ethiopia. Two hundred sixty-six of the cows were categorized as cases based on their history of abortion or stillbirth while the remaining 465 were controls. The presence of antibody to N. caninum was screened using indirect ELISA, while Brucella spp. exposure was assayed serially using Rose Bengal Plate Test and Complement Fixation Test. Exposure to N. caninum was more frequently observed among cases (23.8%) than controls (12.7%), while no significant difference (p > 0.05) was noted for Brucella exposure between the two groups. Moreover, the proportion of cows with disorders like retention of fetal membrane, endometritis and increased inter-calving period were significantly higher (p < 0.05) among Neospora seropositive cows. In conclusion, the finding discloses the strong association of N. caninum with reproductive disorders compared to Brucella spp. exposure. However, neither N. caninum nor Brucella spp. could explain the majority (73.2%) of the reported abortions and stillbirths in cattle. Hence, this observation underscores the need for more intensive investigation on the identification of causes of the aforementioned disorders in dairy cattle of Ethiopia.
Rossetti, Carlos A; Drake, Kenneth L; Siddavatam, Prasad; Lawhon, Sara D; Nunes, Jairo E S; Gull, Tamara; Khare, Sangeeta; Everts, Robin E; Lewin, Harris A; Adams, Leslie Garry
Brucella melitensis causes the most severe and acute symptoms of all Brucella species in human beings and infects hosts primarily through the oral route. The epithelium covering domed villi of jejunal-ileal Peyer's patches is an important site of entry for several pathogens, including Brucella. Here, we use the calf ligated ileal loop model to study temporal in vivo Brucella-infected host molecular and morphological responses. Our results document Brucella bacteremia occurring within 30 min after intraluminal inoculation of the ileum without histopathologic traces of lesions. Based on a system biology Dynamic Bayesian Network modeling approach (DBN) of microarray data, a very early transient perturbation of the host enteric transcriptome was associated with the initial host response to Brucella contact that is rapidly averted allowing invasion and dissemination. A detailed analysis revealed active expression of Syndecan 2, Integrin alpha L and Integrin beta 2 genes, which may favor initial Brucella adhesion. Also, two intestinal barrier-related pathways (Tight Junction and Trefoil Factors Initiated Mucosal Healing) were significantly repressed in the early stage of infection, suggesting subversion of mucosal epithelial barrier function to facilitate Brucella transepithelial migration. Simultaneously, the strong activation of the innate immune response pathways would suggest that the host mounts an appropriate protective immune response; however, the expression of the two key genes that encode innate immunity anti-Brucella cytokines such as TNF-α and IL12p40 were not significantly changed throughout the study. Furthermore, the defective expression of Toll-Like Receptor Signaling pathways may partially explain the lack of proinflammatory cytokine production and consequently the absence of morphologically detectable inflammation at the site of infection. Cumulatively, our results indicate that the in vivo pathogenesis of the early infectious process of Brucella is
Hu, Qiaoyun; Liu, Peng; Yu, Zhengjun; Zhao, Gang; Li, Jun; Teng, Liu; Zhou, Mingguang; Bei, Weicheng; Chen, Huanchun; Jin, Meilin
Streptococcus suis is an important swine and human pathogen, and also an emerging zoonotic agent. A surface-associated subtilisin-like serine protease (SspA) of S. suis was identified by screening a genomic expression library as fragments of this protein reacted most strongly with convalescent-phase pig sera. The sspA gene is present in 29 of 33 S. suis serotypes reference strains and is expressed on the surface of S. suis. Relative real-time quantitative PCR assay demonstrated that sspA mRNA expression in vivo was several thousand fold of that in vitro. A sspA(-) mutant was generated from a S. suis serotype 2 strain SC19 by allelic exchange. The mutant was not different from the wild type strain in subcellular structures and in hemolytic phenotype. However, the virulence of the sspA(-) mutant was markedly lower than the wild type in pigs as demonstrated in experimental infections. These data indicated that the surface-associated protein SspA is a conserved virulence factor of S. suis and is involved in the pathogenesis of S. suis.
Lang, Xulong; Wan, Zhonghai; Pan, Ying; Wang, Xiuran; Wang, Xiaoxu; Bu, Zhaoyang; Qian, Jing; Zeng, Huazong; Wang, Xinglong
Catabolite control protein A (CcpA) serves a key function in the catabolism of Streptococcus suis serotype 2 (S. suis 2) by affecting the biological function and metabolic regulatory mechanisms of this bacterium. The aim of the present study was to identify variations in CcpA expression in S. suis 2 using gene expression profile analysis. Using sequencing and functional analysis, CcpA was demonstrated to play a regulatory role in the expression and regulation of virulence genes, carbon metabolism and immunoregulation in S. suis 2. Gene Ontology and Kyto Encyclopedia of Genes and Genomes analyses indicated that CcpA in S. suis 2 is involved in the regulation of multiple metabolic processes. Furthermore, combined analysis of the transcriptome and metabolite data suggested that metabolites varied due to the modulation of gene expression levels under the influence of CcpA regulation. In addition, metabolic network analysis indicated that CcpA impacted carbon metabolism to a certain extent. Therefore, the present study has provided a more comprehensive analysis of the role of CcpA in the metabolic regulation of S. suis 2, which may facilitate future investigation into this mechanism. Furthermore, the results of the present study provide a foundation for further research into the regulatory function of CcpA and associated metabolic pathways in S. suis 2.
Zhang, Chunping; Zhang, Zhongqiu; Song, Li; Fan, Xuezheng; Wen, Fang; Xu, Shixin; Ning, Yibao
Streptococcus suis serotype 2 is an important zoonotic pathogen. Antimicrobial resistance phenotypes and genotypic characterizations of S. suis 2 from carrier sows and diseased pigs remain largely unknown. In this study, 96 swine S. suis type 2, 62 from healthy sows and 34 from diseased pigs, were analyzed. High frequency of tetracycline resistance was observed, followed by sulfonamides. The lowest resistance of S. suis 2 for β-lactams supports their use as the primary antibiotics to treat the infection of serotype 2. In contrast, 35 of 37 S. suis 2 with MLSB phenotypes were isolated from healthy sows, mostly encoded by the ermB and/or the mefA genes. Significantly lower frequency of mrp+/epf+/sly+ was observed among serotype 2 from healthy sows compared to those from diseased pigs. Furthermore, isolates from diseased pigs showed more homogeneously genetic patterns, with most of them clustered in pulsotypes A and E. The data indicate the genetic complexity of S. suis 2 between herds and a close linkage among isolates from healthy sows and diseased pigs. Moreover, many factors, such as extensive use of tetracycline or diffusion of Tn916 with tetM, might have favored for the pathogenicity and widespread dissemination of S. suis serotype 2. PMID:26064892
Spoerry, Christian; Seele, Jana; Valentin-Weigand, Peter; Baums, Christoph G.; von Pawel-Rammingen, Ulrich
Streptococcus suis is a major endemic pathogen of pigs causing meningitis, arthritis, and other diseases. Zoonotic S. suis infections are emerging in humans causing similar pathologies as well as severe conditions such as toxic shock-like syndrome. Recently, we discovered an IdeS family protease of S. suis that exclusively cleaves porcine IgM and represents the first virulence factor described, linking S. suis to pigs as their natural host. Here we report the identification and characterization of a novel, unrelated protease of S. suis that exclusively targets porcine IgG. This enzyme, designated IgdE for immunoglobulin G-degrading enzyme of S. suis, is a cysteine protease distinct from previous characterized streptococcal immunoglobulin degrading proteases of the IdeS family and mediates efficient cleavage of the hinge region of porcine IgG with a high degree of specificity. The findings that all S. suis strains investigated possess the IgG proteolytic activity and that piglet serum samples contain specific antibodies against IgdE strongly indicate that the protease is expressed in vivo during infection and represents a novel and putative important bacterial virulence/colonization determinant, and a thus potential therapeutic target. PMID:26861873
Willenborg, Jörg; Huber, Claudia; Koczula, Anna; Lange, Birgit; Eisenreich, Wolfgang; Valentin-Weigand, Peter; Goethe, Ralph
Streptococcus suis is a neglected zoonotic pathogen that has to adapt to the nutritional requirements in the different host niches encountered during infection and establishment of invasive diseases. To dissect the central metabolic activity of S. suis under different conditions of nutrient availability, we performed labeling experiments starting from [(13)C]glucose specimens and analyzed the resulting isotopologue patterns in amino acids of S. suis grown under in vitro and ex vivo conditions. In combination with classical growth experiments, we found that S. suis is auxotrophic for Arg, Gln/Glu, His, Leu, and Trp in chemically defined medium. De novo biosynthesis was shown for Ala, Asp, Ser, and Thr at high rates and for Gly, Lys, Phe, Tyr, and Val at moderate or low rates, respectively. Glucose degradation occurred mainly by glycolysis and to a minor extent by the pentose phosphate pathway. Furthermore, the exclusive formation of oxaloacetate by phosphoenolpyruvate (PEP) carboxylation became evident from the patterns in de novo synthesized amino acids. Labeling experiments with S. suis grown ex vivo in blood or cerebrospinal fluid reflected the metabolic adaptation to these host niches with different nutrient availability; however, similar key metabolic activities were identified under these conditions. This points at the robustness of the core metabolic pathways in S. suis during the infection process. The crucial role of PEP carboxylation for growth of S. suis in the host was supported by experiments with a PEP carboxylase-deficient mutant strain in blood and cerebrospinal fluid.
Willenborg, Jörg; Huber, Claudia; Koczula, Anna; Lange, Birgit; Eisenreich, Wolfgang; Valentin-Weigand, Peter; Goethe, Ralph
Streptococcus suis is a neglected zoonotic pathogen that has to adapt to the nutritional requirements in the different host niches encountered during infection and establishment of invasive diseases. To dissect the central metabolic activity of S. suis under different conditions of nutrient availability, we performed labeling experiments starting from [13C]glucose specimens and analyzed the resulting isotopologue patterns in amino acids of S. suis grown under in vitro and ex vivo conditions. In combination with classical growth experiments, we found that S. suis is auxotrophic for Arg, Gln/Glu, His, Leu, and Trp in chemically defined medium. De novo biosynthesis was shown for Ala, Asp, Ser, and Thr at high rates and for Gly, Lys, Phe, Tyr, and Val at moderate or low rates, respectively. Glucose degradation occurred mainly by glycolysis and to a minor extent by the pentose phosphate pathway. Furthermore, the exclusive formation of oxaloacetate by phosphoenolpyruvate (PEP) carboxylation became evident from the patterns in de novo synthesized amino acids. Labeling experiments with S. suis grown ex vivo in blood or cerebrospinal fluid reflected the metabolic adaptation to these host niches with different nutrient availability; however, similar key metabolic activities were identified under these conditions. This points at the robustness of the core metabolic pathways in S. suis during the infection process. The crucial role of PEP carboxylation for growth of S. suis in the host was supported by experiments with a PEP carboxylase-deficient mutant strain in blood and cerebrospinal fluid. PMID:25575595
Yin, Supeng; Li, Ming; Rao, Xiancai; Yao, Xinyue; Zhong, Qiu; Wang, Min; Wang, Jing; Peng, Yizhi; Tang, Jiaqi; Hu, Fuquan; Zhao, Yan
Streptococcus suis serotype 2 is an emerging zoonotic pathogen that triggered two outbreaks of streptococcal toxic shock syndrome (STSS) in China. Our previous research demonstrated that a type IV secretion system (T4SS) harbored in the 89K pathogenicity island contributes to the pathogenicity of S. suis 2. In the present study, a shotgun proteomics approach was employed to identify the effectors secreted by T4SS in S. suis 2, and surface-associated subtilisin-like protease-1 (SspA-1) was identified as a potential virulence effector. Western blot analysis and pull-down assay revealed that SspA-1 secretion depends on T4SS. Knockout mutations affecting sspA-1 attenuated S. suis 2 and impaired the pathogen’s ability to trigger inflammatory response in mice. And purified SspA-1 induced the secretion of IL-6, TNF-α, and IL-12p70 in THP-1 cells directly. SspA-1 is the first T4SS virulence effector reported in Gram-positive bacteria. Overall, these findings allow us to gain further insights into the pathogenesis of T4SS and STSS. PMID:27270879
Athey, Taryn B. T.; Vaillancourt, Katy; Frenette, Michel; Gottschalk, Marcelo
Recently, we reported the purification and characterization of three distinct lantibiotics (named suicin 90-1330, suicin 3908, and suicin 65) produced by Streptococcus suis. In this study, we investigated the distribution of the three suicin lantibiotic gene clusters among serotype 2 S. suis strains belonging to sequence type (ST) 25 and ST28, the two dominant STs identified in North America. The genomes of 102 strains were interrogated for the presence of suicin gene clusters encoding suicins 90-1330, 3908, and 65. The gene cluster encoding suicin 65 was the most prevalent and mainly found among ST25 strains. In contrast, none of the genes related to suicin 90-1330 production were identified in 51 ST25 strains nor in 35/51 ST28 strains. However, the complete suicin 90-1330 gene cluster was found in ten ST28 strains, although some genes in the cluster were truncated in three of these isolates. The vast majority (101/102) of S. suis strains did not possess any of the genes encoding suicin 3908. In conclusion, this study indicates heterogeneous distribution of suicin genes in S. suis. PMID:28078298
Palmieri, Nicola; Shrestha, Aruna; Ruttkowski, Bärbel; Beck, Tomas; Vogl, Claus; Tomley, Fiona; Blake, Damer P; Joachim, Anja
Vaccine development targeting protozoan parasites remains challenging, partly due to the complex interactions between these eukaryotes and the host immune system. Reverse vaccinology is a promising approach for direct screening of genome sequence assemblies for new vaccine candidate proteins. Here, we applied this paradigm to Cystoisospora suis, an apicomplexan parasite that causes enteritis and diarrhea in suckling piglets and economic losses in pig production worldwide. Using Next Generation Sequencing we produced an ∼84Mb sequence assembly for the C. suis genome, making it the first available reference for the genus Cystoisospora. Then, we derived a manually curated annotation of more than 11,000 protein-coding genes and applied the tool Vacceed to identify 1,168 vaccine candidates by screening the predicted C. suis proteome. To refine the set of candidates, we looked at proteins that are highly expressed in merozoites and specific to apicomplexans. The stringent set of candidates included 220 proteins, among which were 152 proteins with unknown function, 17 surface antigens of the SAG and SRS gene families, 12 proteins of the apicomplexan-specific secretory organelles including AMA1, MIC6, MIC13, ROP6, ROP12, ROP27, ROP32 and three proteins related to cell adhesion. Finally, we demonstrated in vitro the immunogenic potential of a C. suis-specific 42kDa transmembrane protein, which might constitute an attractive candidate for further testing.
Tharavichitkul, Prasit; Wongsawan, Kanreuthai; Takenami, Naoki; Pruksakorn, Sumalee; Fongcom, Achara; Gottschalk, Marcelo; Khanthawa, Banyong; Supajatura, Volaluk; Takai, Shinji
Streptococcus suis infection is a severe zoonotic disease commonly found in Northern Thailand where people often consume raw pork and/or pig's blood. The most frequent clinical presentations are meningitis, sepsis, and endocarditis with higher rate of mortality and hearing loss sequelae. To clarify the correlation between pulsed-field gel electrophoresis (PFGE) groups and mrp/epf/sly genotypes of S. suis serotype 2, 62 patient and 4 healthy pig isolates from Northern Thailand were studied. By PFGE analysis, at 66% homology, most human isolates (69.4%) and 1 pig isolate were in group A, whereas 14.5% of human isolates and 3 out of 4 pig isolates were in group D. According to mrp/epf/sly genotypes, 80.6% of human isolates were identified in mrp (+) epf (-) sly (-) and only 12.9% were in mrp (-) epf (-) sly (+) genotypes; in contrast, 1 and 3 pig isolates were detected in these two genotypes, respectively. Interestingly, all isolates of S. suis serotype 2 classified in PFGE groups A, B, and E were set in mrp (+) epf (-) sly (-) genotypes. These data show a close correlation between PFGE groups and mrp/epf/sly genotypes of human S. suis serotype 2.
Tharavichitkul, Prasit; Wongsawan, Kanreuthai; Takenami, Naoki; Pruksakorn, Sumalee; Fongcom, Achara; Gottschalk, Marcelo; Khanthawa, Banyong; Supajatura, Volaluk; Takai, Shinji
Streptococcus suis infection is a severe zoonotic disease commonly found in Northern Thailand where people often consume raw pork and/or pig's blood. The most frequent clinical presentations are meningitis, sepsis, and endocarditis with higher rate of mortality and hearing loss sequelae. To clarify the correlation between pulsed-field gel electrophoresis (PFGE) groups and mrp/epf/sly genotypes of S. suis serotype 2, 62 patient and 4 healthy pig isolates from Northern Thailand were studied. By PFGE analysis, at 66% homology, most human isolates (69.4%) and 1 pig isolate were in group A, whereas 14.5% of human isolates and 3 out of 4 pig isolates were in group D. According to mrp/epf/sly genotypes, 80.6% of human isolates were identified in mrp+epf−sly− and only 12.9% were in mrp−epf−sly+ genotypes; in contrast, 1 and 3 pig isolates were detected in these two genotypes, respectively. Interestingly, all isolates of S. suis serotype 2 classified in PFGE groups A, B, and E were set in mrp+epf−sly− genotypes. These data show a close correlation between PFGE groups and mrp/epf/sly genotypes of human S. suis serotype 2. PMID:24734186
Němejc, Karel; Sak, Bohumil; Květoňová, Dana; Hanzal, Vladimír; Jeníková, Martina; Kváč, Martin
A total of 193 faecal samples of adult Eurasian wild boars were collected at 12 enclosures across the Czech Republic and examined for Cryptosporidium infection using both microscopic and molecular tools. Cryptosporidium oocysts were not detected in any of the 193 faecal samples examined using the aniline-carbol-methyl violet staining method. Thirty-two positive cases of Cryptosporidium infection were detected using either genus- or species-specific nested PCR. Mono-infection with Cryptosporidium suis and Cryptosporidium pig genotype II were found in 13 and 7 cases, respectively. Five mixed infections of C. suis and Cryptosporidium pig genotype II were detected using PCR/RFLP with genus specific primers. The number of detected mixed infections increased 2.4 fold when a species-specific PCR was employed. No other Cryptosporidium spp. was detected. Unlike cryptosporidiosis of domestic pigs, C. suis was detected as a dominant species infecting adult Eurasian wild boars. There was no association between diarrhoea and the presence of Cryptosporidium infection in the Eurasian wild boars studied. This is the first report on the Cryptosporidium infection caused by C. suis and Cryptosporidium pig genotype II in Eurasian wild boars (Sus scrofa).
Schwarz, Lukas; Joachim, Anja; Worliczek, Hanna Lucia
Cystoisospora suis is the most pathogenic species of coccidia in suckling piglets, affecting them predominantly within their first three weeks of life. The clinical signs of neonatal cystoisosporosis include watery diarrhea and wasting, leading to significant economic losses for the farmer. Since neonatal piglets have an immature immune system, colostral transfer of maternal factors such as immune cells or antibodies is essential for controlling infections at that age. However, the role of C. suis-specific antibodies transferred from the sow to the piglets and possible correlations between antibody levels in the piglets acquired from colostrum with the clinical outcome of disease are currently not understood. To address this issue, 12 non-infected piglets and 14 piglets experimentally infected with C. suis on the third day of life were examined during their first four weeks of life. IgG, IgA, and IgM titers in the blood serum specific for sporozoites and merozoites of C. suis were evaluated, along with oocyst excretion and fecal consistency. Additionally, the antibody content in the colostrum and milk of three mother sows was determined. A transfer of naturally acquired C. suis-specific antibodies from sows to piglets with the colostrum could be demonstrated. Maternal antibodies in piglets' blood sera did not persist for longer than 14-21 days except for IgG which was present in high titers until the end of the study. Within 2-3 weeks after birth the onset of endogenous antibody production was noticed. Titers in blood serum showed a correlation with the severity of diarrhea which was positive for IgG and IgM (possibly due to increased consumption or loss of these antibodies) and negative for IgA. C. suis-specific mucus antibodies isolated from infected and non-infected piglets (n=6/group) on the 28th day of life were present in both groups, showing significantly higher titers of IgA and IgM in infected piglets. Maternally transferred antibodies acquired by natural
Avalos-Téllez, Rosalía; Ramírez-Pfeiffer, Carlos; Hernández-Castro, Rigoberto; Díaz-Aparicio, Efrén; Sánchez-Domínguez, Carlos; Zavala-Norzagaray, Alan; Arellano-Reynoso, Beatriz; Suárez-Güemes, Francisco; Aguirre, A Alonso; Aurioles-Gamboa, David
Infections with Brucella ceti and pinnipedialis are prevalent in marine mammals worldwide. A total of 22 California sea lions (Zalophus californianus) were examined to determine their exposure to Brucella spp. at San Esteban Island in the Gulf of California, Mexico, in June and July 2011. Although samples of blood, vaginal mucus and milk cultured negative for these bacteria, the application of rose Bengal, agar gel immunodiffusion, PCR and modified fluorescence polarization assays found that five animals (22.7%) had evidence of exposure to Brucella strains. The data also suggested that in two of these five sea lions the strains involved were of terrestrial origin, a novel finding in marine mammals. Further work will be required to validate and determine the epidemiological significance of this finding.
Sales, Indiara dos Santos; Folly, Márcio Manhães; Garcia, Luize Néli Nunes; Ramos, Tatiane Mendes Varela; da Silva, Mariana Cristina; Pereira, Martha Maria
The presence of Leptospira spp. and Brucella spp. antibodies was investigated in serum samples from 2