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Sample records for pathogen streptococcus suis

  1. Restoration of Bioactive Lantibiotic Suicin from a Remnant lan Locus of Pathogenic Streptococcus suis Serotype 2

    PubMed Central

    Wang, Jian; Gao, Yong; Teng, Kunling; Zhang, Jie; Sun, Shutao

    2014-01-01

    Lantibiotics are ribosomally synthesized, posttranslationally modified antimicrobial peptides. Their biosynthesis genes are usually organized in gene clusters, which are mainly found in Gram-positive bacteria, including pathogenic streptococci. Three highly virulent Streptococcus suis serotype 2 strains (98HAH33, 05ZYH33, and SC84) have been shown to contain an 89K pathogenicity island. Here, on these islands, we unveiled and reannotated a putative lantibiotic locus designated sui which contains a virulence-associated two-component regulator, suiK-suiR. In silico analysis revealed that the putative lantibiotic modification gene suiM was interrupted by a 7.9-kb integron and that other biosynthesis-related genes contained various frameshift mutations. By reconstituting the intact suiM in Escherichia coli together with a semi-in vitro biosynthesis system, a putative lantibiotic named suicin was produced with bactericidal activities against a variety of Gram-positive strains, including pathogenic streptococci and vancomycin-resistant enterococci. Ring topology dissection indicated that the 34-amino-acid lantibiotic contained two methyllanthionine residues and one disulfide bridge, which render suicin in an N-terminal linear and C-terminal globular shape. To confirm the function of suiK-suiR, SuiR was overexpressed and purified. In vitro analysis showed that SuiR could specifically bind to the suiA gene promoter. Its coexpression with suiK could activate suiA gene promoter in Lactococcus lactis NZ9000. Conclusively, we obtained a novel lantibiotic suicin by restoring its production from the remnant sui locus and demonstrated that virulence-associated SuiK-SuiR regulates its production. PMID:24271178

  2. Whole genome investigation of a divergent clade of the pathogen Streptococcus suis

    PubMed Central

    Baig, Abiyad; Weinert, Lucy A.; Peters, Sarah E.; Howell, Kate J.; Chaudhuri, Roy R.; Wang, Jinhong; Holden, Matthew T. G.; Parkhill, Julian; Langford, Paul R.; Rycroft, Andrew N.; Wren, Brendan W.; Tucker, Alexander W.; Maskell, Duncan J.

    2015-01-01

    Streptococcus suis is a major porcine and zoonotic pathogen responsible for significant economic losses in the pig industry and an increasing number of human cases. Multiple isolates of S. suis show marked genomic diversity. Here, we report the analysis of whole genome sequences of nine pig isolates that caused disease typical of S. suis and had phenotypic characteristics of S. suis, but their genomes were divergent from those of many other S. suis isolates. Comparison of protein sequences predicted from divergent genomes with those from normal S. suis reduced the size of core genome from 793 to only 397 genes. Divergence was clear if phylogenetic analysis was performed on reduced core genes and MLST alleles. Phylogenies based on certain other genes (16S rRNA, sodA, recN, and cpn60) did not show divergence for all isolates, suggesting recombination between some divergent isolates with normal S. suis for these genes. Indeed, there is evidence of recent recombination between the divergent and normal S. suis genomes for 249 of 397 core genes. In addition, phylogenetic analysis based on the 16S rRNA gene and 132 genes that were conserved between the divergent isolates and representatives of the broader Streptococcus genus showed that divergent isolates were more closely related to S. suis. Six out of nine divergent isolates possessed a S. suis-like capsule region with variation in capsular gene sequences but the remaining three did not have a discrete capsule locus. The majority (40/70), of virulence-associated genes in normal S. suis were present in the divergent genomes. Overall, the divergent isolates extend the current diversity of S. suis species but the phenotypic similarities and the large amount of gene exchange with normal S. suis gives insufficient evidence to assign these isolates to a new species or subspecies. Further, sampling and whole genome analysis of more isolates is warranted to understand the diversity of the species. PMID:26583006

  3. Streptococcus suis infection

    PubMed Central

    Feng, Youjun; Zhang, Huimin; Wu, Zuowei; Wang, Shihua; Cao, Min; Hu, Dan; Wang, Changjun

    2014-01-01

    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

  4. Isolation, Characterization and Biological Properties of Membrane Vesicles Produced by the Swine Pathogen Streptococcus suis

    PubMed Central

    Haas, Bruno; Grenier, Daniel

    2015-01-01

    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

  5. Antimicrobial activity of nisin against the swine pathogen Streptococcus suis and its synergistic interaction with antibiotics.

    PubMed

    Lebel, Geneviève; Piché, Fanny; Frenette, Michel; Gottschalk, Marcelo; Grenier, Daniel

    2013-12-01

    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. PMID:24096107

  6. Deregulated balance of omega-6 and omega-3 polyunsaturated fatty acids following infection by the zoonotic pathogen Streptococcus suis.

    PubMed

    Lachance, Claude; Segura, Mariela; Dominguez-Punaro, Maria C; Wojewodka, Gabriella; De Sanctis, Juan B; Radzioch, Danuta; Gottschalk, Marcelo

    2014-05-01

    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. PMID:24549326

  7. Current Taxonomical Situation of Streptococcus suis.

    PubMed

    Okura, Masatoshi; Osaki, Makoto; Nomoto, Ryohei; Arai, Sakura; Osawa, Ro; Sekizaki, Tsutomu; Takamatsu, Daisuke

    2016-01-01

    Streptococcus suis, a major porcine pathogen and an important zoonotic agent, is considered to be composed of phenotypically and genetically diverse strains. However, recent studies reported several "S. suis-like strains" that were identified as S. suis by commonly used methods for the identification of this bacterium, but were regarded as distinct species from S. suis according to the standards of several taxonomic analyses. Furthermore, it has been suggested that some S. suis-like strains can be assigned to several novel species. In this review, we discuss the current taxonomical situation of S. suis with a focus on (1) the classification history of the taxon of S. suis; (2) S. suis-like strains revealed by taxonomic analyses; (3) methods for detecting and identifying this species, including a novel method that can distinguish S. suis isolates from S. suis-like strains; and (4) current topics on the reclassification of S. suis-like strains. PMID:27348006

  8. Functional definition of BirA suggests a biotin utilization pathway in the zoonotic pathogen Streptococcus suis.

    PubMed

    Ye, Huiyan; Cai, Mingzhu; Zhang, Huimin; Li, Zhencui; Wen, Ronghui; Feng, Youjun

    2016-01-01

    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

  9. Functional definition of BirA suggests a biotin utilization pathway in the zoonotic pathogen Streptococcus suis

    PubMed Central

    Ye, Huiyan; Cai, Mingzhu; Zhang, Huimin; Li, Zhencui; Wen, Ronghui; Feng, Youjun

    2016-01-01

    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

  10. Genomic signatures of human and animal disease in the zoonotic pathogen Streptococcus suis

    PubMed Central

    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.; Bossé, Janine T.; Li, Yanwen; Maglennon, Gareth A.; Matthews, Dominic; Cuccui, Jon; Terra, Vanessa

    2015-01-01

    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. PMID:25824154

  11. [Lytic phages and prophages of Streptococcus suis--a review].

    PubMed

    Tang, Fang; Lu, Chengping

    2015-04-01

    Streptococcus suis (S. suis) is an important zoonosis and pathogen that can carry prophages. In this review, we focus on the recent advances in our understanding of lytic phage and lysogenic phage of S. suis, including the morphology of S. suis lytic phage, the functions of lysin and terminase large subunit encoded by S. suis lytic phage, comparative genomics of S. suis prophages, lysogenic. conversion between S. suis lytic phage and prophage. Furthermore, prospective evolution of interactions between phage and host was discussed. PMID:26211312

  12. Colonization of suckling pigs by Streptococcus suis with particular reference to pathogenic serotype 2 strains.

    PubMed Central

    Torremorell, M; Calsamiglia, M; Pijoan, C

    1998-01-01

    Three swine commercial farms with high mortality rates in nursery pigs due to Streptococcus suis serotype 2 were studied. Brain samples from diseased animals were collected for a period of 6 to 10 mo and used to isolate the strain that was responsible for the mortality (virulent strain) in each farm. Tonsil swabs from piglets at 5, 10 and 15 d were taken to assess both total colonization and colonization by the virulent strain. The effect of sow vaccination against S. suis on colonization was evaluated in 1 of the farms. All suspect tonsil isolates were identified biochemically and then tested against serotype 2. The genomic patterns of serotype 2 isolates were compared to that of the virulent strain using Rep-PCR. Results showed that total colonization by S. suis occurred very early in the pigs' life, with most animals being colonized by weaning age. Prevalence of colonization by serotype 2 strains was much lower than total colonization. After comparing serotype 2 isolates with the virulent strains, only 1 tonsillar isolate had the same genomic pattern as the virulent strain and it belonged to a 4-week-old weaned pig. The genomic pattern of the virulent strain was not found in any tonsillar isolate from 15-day-old or younger pigs. Although limited by sample size, sow vaccination against S. suis increased total colonization at the same time significantly decreasing colonization by serotype 2 strains. Even though most pigs are colonized early in age by S. suis, colonization by the virulent strain is of low prevalence and delayed in time. This could constitute a risk factor for developing the disease later in time, because animals would be colonized when maternal immunity is no longer present, allowing the organism to become systemic. Images Figure 1. Figure 2. PMID:9442935

  13. Molecular Basis of Resistance to Selected Antimicrobial Agents in the Emerging Zoonotic Pathogen Streptococcus suis.

    PubMed

    Gurung, Mamata; Tamang, Migma Dorji; Moon, Dong Chan; Kim, Su-Ran; Jeong, Jin-Ha; Jang, Geum-Chan; Jung, Suk-Chan; Park, Yong-Ho; Lim, Suk-Kyung

    2015-07-01

    Characterization of 227 Streptococcus suis strains isolated from pigs during 2010 to 2013 showed high levels of resistance to clindamycin (95.6%), tilmicosin (94.7%), tylosin (93.8%), oxytetracycline (89.4%), chlortetracycline (86.8%), tiamulin (72.7%), neomycin (70.0%), enrofloxacin (56.4%), penicillin (56.4%), ceftiofur (55.9%), and gentamicin (55.1%). Resistance to tetracyclines, macrolides, aminoglycosides, and fluoroquinolone was attributed to the tet gene, erm(B), erm(C), mph(C), and mef(A) and/or mef(E) genes, aph(3')-IIIa and aac(6')-Ie-aph(2″)-Ia genes, and single point mutations in the quinolone resistance-determining region of ParC and GyrA, respectively. PMID:25903569

  14. Molecular Basis of Resistance to Selected Antimicrobial Agents in the Emerging Zoonotic Pathogen Streptococcus suis

    PubMed Central

    Gurung, Mamata; Tamang, Migma Dorji; Moon, Dong Chan; Kim, Su-Ran; Jeong, Jin-Ha; Jang, Geum-Chan; Jung, Suk-Chan; Park, Yong-Ho

    2015-01-01

    Characterization of 227 Streptococcus suis strains isolated from pigs during 2010 to 2013 showed high levels of resistance to clindamycin (95.6%), tilmicosin (94.7%), tylosin (93.8%), oxytetracycline (89.4%), chlortetracycline (86.8%), tiamulin (72.7%), neomycin (70.0%), enrofloxacin (56.4%), penicillin (56.4%), ceftiofur (55.9%), and gentamicin (55.1%). Resistance to tetracyclines, macrolides, aminoglycosides, and fluoroquinolone was attributed to the tet gene, erm(B), erm(C), mph(C), and mef(A) and/or mef(E) genes, aph(3′)-IIIa and aac(6′)-Ie-aph(2″)-Ia genes, and single point mutations in the quinolone resistance-determining region of ParC and GyrA, respectively. PMID:25903569

  15. Structural insight for substrate tolerance to 2-deoxyribose-5-phosphate aldolase from the pathogen Streptococcus suis.

    PubMed

    Cao, Thinh-Phat; Kim, Joong-Su; Woo, Mi-Hee; Choi, Jin Myung; Jun, Youngsoo; Lee, Kun Ho; Lee, Sung Haeng

    2016-04-01

    2-deoxyribose-5-phosphate aldolase (DERA) is a class I aldolase that catalyzes aldol condensation of two aldehydes in the active site, which is particularly germane in drug manufacture. Structural and biochemical studies have shown that the active site of DERA is typically loosely packed and displays broader substrate specificity despite sharing conserved folding architecture with other aldolases. The most distinctive structural feature of DERA compared to other aldolases is short and flexible C-terminal region. This region is also responsible for substrate recognition. Therefore, substrate tolerance may be related to the C-terminal structural features of DERA. Here, we determined the crystal structures of full length and C-terminal truncated DERA from Streptococcus suis (SsDERA). In common, both contained the typical (α/β)8 TIM-barrel fold of class I aldolases. Surprisingly, C-terminal truncation resulting in missing the last α9 and β8 secondary elements, allowed DERA to maintain activity comparable to the fulllength enzyme. Specifically, Arg186 and Ser205 residues at the C-terminus appeared mutually supplemental or less indispensible for substrate phosphate moiety recognition. Our results suggest that DERA might adopt a shorter C-terminal region than conventional aldolases during evolution pathway, resulting in a broader range of substrate tolerance through active site flexibility. PMID:27033207

  16. Streptococcus suis, an important pig pathogen and emerging zoonotic agent—an update on the worldwide distribution based on serotyping and sequence typing

    PubMed Central

    Goyette-Desjardins, Guillaume; Auger, Jean-Philippe; Xu, Jianguo; Segura, Mariela; Gottschalk, Marcelo

    2014-01-01

    Streptococcus suis is an important pathogen causing economic problems in the pig industry. Moreover, it is a zoonotic agent causing severe infections to people in close contact with infected pigs or pork-derived products. Although considered sporadic in the past, human S. suis infections have been reported during the last 45 years, with two large outbreaks recorded in China. In fact, the number of reported human cases has significantly increased in recent years. In this review, we present the worldwide distribution of serotypes and sequence types (STs), as determined by multilocus sequence typing, for pigs (between 2002 and 2013) and humans (between 1968 and 2013). The methods employed for S. suis identification and typing, the current epidemiological knowledge regarding serotypes and STs and the zoonotic potential of S. suis are discussed. Increased awareness of S. suis in both human and veterinary diagnostic laboratories and further establishment of typing methods will contribute to our knowledge of this pathogen, especially in regions where complete and/or recent data is lacking. More research is required to understand differences in virulence that occur among S. suis strains and if these differences can be associated with specific serotypes or STs. PMID:26038745

  17. Suicin 90-1330 from a Nonvirulent Strain of Streptococcus suis: a Nisin-Related Lantibiotic Active on Gram-Positive Swine Pathogens

    PubMed Central

    LeBel, Geneviève; Vaillancourt, Katy; Frenette, Michel; Gottschalk, Marcelo

    2014-01-01

    Streptococcus suis serotype 2 is known to cause severe infections (meningitis, endocarditis, and septicemia) in pigs and is considered an emerging zoonotic agent. Antibiotics have long been used in the swine industry for disease treatment/prevention and growth promoters. This pattern of utilization resulted in the spread of antibiotic resistance in S. suis worldwide. Interestingly, pigs may harbor S. suis in their tonsils without developing diseases, while North American strains belonging to the sequence type 28 (ST28) are nonvirulent in animal models. Consequently, the aim of this study was to purify and characterize a bacteriocin produced by a nonvirulent strain of S. suis serotype 2, with a view to a potential therapeutic and preventive application. S. suis 90-1330 belonging to ST28 and previously shown to be nonvirulent in an animal model exhibited antibacterial activity toward all S. suis pathogenic isolates tested. The bacteriocin produced by this strain was purified to homogeneity by cationic exchange and reversed-phase fast protein liquid chromatography. Given its properties (molecular mass of <4 kDa, heat, pH and protease stability, and the presence of modified amino acids), the bacteriocin, named suicin 90-1330, belongs to the lantibiotic class. Using a DNA-binding fluorophore, the bacteriocin was found to possess a membrane permeabilization activity. When tested on other swine pathogens, the suicin showed activity against Staphylococcus hyicus and Staphylococcus aureus, whereas it was inactive against all Gram-negative bacteria tested. Amino acid sequencing of the purified bacteriocin showed homology (90.9% identity) with nisin U produced by Streptococcus uberis. The putative gene cluster involved in suicin production was amplified by PCR and sequence analysis revealed the presence of 11 open reading frames, including the structural gene and those required for the modification of amino acids, export, regulation, and immunity. Further studies will

  18. Suicin 90-1330 from a nonvirulent strain of Streptococcus suis: a nisin-related lantibiotic active on gram-positive swine pathogens.

    PubMed

    LeBel, Geneviève; Vaillancourt, Katy; Frenette, Michel; Gottschalk, Marcelo; Grenier, Daniel

    2014-09-01

    Streptococcus suis serotype 2 is known to cause severe infections (meningitis, endocarditis, and septicemia) in pigs and is considered an emerging zoonotic agent. Antibiotics have long been used in the swine industry for disease treatment/prevention and growth promoters. This pattern of utilization resulted in the spread of antibiotic resistance in S. suis worldwide. Interestingly, pigs may harbor S. suis in their tonsils without developing diseases, while North American strains belonging to the sequence type 28 (ST28) are nonvirulent in animal models. Consequently, the aim of this study was to purify and characterize a bacteriocin produced by a nonvirulent strain of S. suis serotype 2, with a view to a potential therapeutic and preventive application. S. suis 90-1330 belonging to ST28 and previously shown to be nonvirulent in an animal model exhibited antibacterial activity toward all S. suis pathogenic isolates tested. The bacteriocin produced by this strain was purified to homogeneity by cationic exchange and reversed-phase fast protein liquid chromatography. Given its properties (molecular mass of <4 kDa, heat, pH and protease stability, and the presence of modified amino acids), the bacteriocin, named suicin 90-1330, belongs to the lantibiotic class. Using a DNA-binding fluorophore, the bacteriocin was found to possess a membrane permeabilization activity. When tested on other swine pathogens, the suicin showed activity against Staphylococcus hyicus and Staphylococcus aureus, whereas it was inactive against all Gram-negative bacteria tested. Amino acid sequencing of the purified bacteriocin showed homology (90.9% identity) with nisin U produced by Streptococcus uberis. The putative gene cluster involved in suicin production was amplified by PCR and sequence analysis revealed the presence of 11 open reading frames, including the structural gene and those required for the modification of amino acids, export, regulation, and immunity. Further studies will

  19. Mechanisms of Host-Pathogen Protein Complex Formation and Bacterial Immune Evasion of Streptococcus suis Protein Fhb.

    PubMed

    Li, Xueqin; Liu, Peng; Gan, Shuzhen; Zhang, Chunmao; Zheng, Yuling; Jiang, Yongqiang; Yuan, Yuan

    2016-08-12

    Streptococcus suis serotype 2 (S. suis 2)-induced sepsis and meningitis are often accompanied by bacteremia. The evasion of polymorphonuclear leukocyte-mediated phagocytic clearance is central to the establishment of bacteremia caused by S. suis 2 and is facilitated by the ability of factor H (FH)-binding protein (Fhb) to bind FH on the bacterial surface, thereby impeding alternative pathway complement activation and phagocytic clearance. Here, C3b/C3d was found to bind to Fhb, along with FH, forming a large immune complex. The formation of this immune complex was mediated by domain II of Fhb via electrostatic and hydrophobic interactions, which, to our knowledge, is a new type of interaction. Interestingly, Fhb was found to be associated with the cell envelope and also present in the culture supernatant, where secreted Fhb inhibited complement activation via interactions with domain II, thereby enhancing antiphagocytic clearance by polymorphonuclear leukocytes. Thus, Fhb is a multifunctional bacterial protein, which binds host complement component C3 as well as FH and interferes with innate immune recognition in a secret protein manner. S. suis 2 therefore appears to have developed a new strategy to combat host innate immunity and enhance survival in host blood. PMID:27342778

  20. Overcoming function annotation errors in the Gram-positive pathogen Streptococcus suis by a proteomics-driven approach

    PubMed Central

    Rodríguez-Ortega, Manuel J; Luque, Inmaculada; Tarradas, Carmen; Bárcena, José A

    2008-01-01

    Background Annotation of protein-coding genes is a key step in sequencing projects. Protein functions are mainly assigned on the basis of the amino acid sequence alone by searching of homologous proteins. However, fully automated annotation processes often lead to wrong prediction of protein functions, and therefore time-intensive manual curation is often essential. Here we describe a fast and reliable way to correct function annotation in sequencing projects, focusing on surface proteomes. We use a proteomics approach, previously proven to be very powerful for identifying new vaccine candidates against Gram-positive pathogens. It consists of shaving the surface of intact cells with two proteases, the specific cleavage-site trypsin and the unspecific proteinase K, followed by LC/MS/MS analysis of the resulting peptides. The identified proteins are contrasted by computational analysis and their sequences are inspected to correct possible errors in function prediction. Results When applied to the zoonotic pathogen Streptococcus suis, of which two strains have been recently sequenced and annotated, we identified a set of surface proteins without cytoplasmic contamination: all the proteins identified had exporting or retention signals towards the outside and/or the cell surface, and viability of protease-treated cells was not affected. The combination of both experimental evidences and computational methods allowed us to determine that two of these proteins are putative extracellular new adhesins that had been previously attributed a wrong cytoplasmic function. One of them is a putative component of the pilus of this bacterium. Conclusion We illustrate the complementary nature of laboratory-based and computational methods to examine in concert the localization of a set of proteins in the cell, and demonstrate the utility of this proteomics-based strategy to experimentally correct function annotation errors in sequencing projects. This approach also contributes to

  1. Carbohydrate Availability Regulates Virulence Gene Expression in Streptococcus suis

    PubMed Central

    Ferrando, M. Laura; van Baarlen, Peter; Orrù, Germano; Piga, Rosaria; Bongers, Roger S.; Wels, Michiel; De Greeff, Astrid; Smith, Hilde E.; Wells, Jerry M.

    2014-01-01

    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

  2. Carbohydrate availability regulates virulence gene expression in Streptococcus suis.

    PubMed

    Ferrando, M Laura; van Baarlen, Peter; Orrù, Germano; Piga, Rosaria; Bongers, Roger S; Wels, Michiel; De Greeff, Astrid; Smith, Hilde E; Wells, Jerry M

    2014-01-01

    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

  3. Characterisation of Streptococcus suis isolates from wild boars (Sus scrofa).

    PubMed

    Sánchez del Rey, Verónica; Fernández-Garayzábal, José F; Mentaberre, Gregorio; Briones, Víctor; Lavín, Santiago; Domínguez, Lucas; Gottschalk, Marcelo; Vela, Ana Isabel

    2014-06-01

    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. PMID:24726078

  4. Streptococcus suis, an Important Cause of Adult Bacterial Meningitis in Northern Vietnam

    PubMed Central

    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

    2009-01-01

    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

  5. Streptococcus suis infection in Taiwan, 2000-2011.

    PubMed

    Tsai, Hsih-Yeh; Liao, Chun-Hsing; Liu, Chia-Ying; Huang, Yu-Tsung; Teng, Lee-Jene; Hsueh, Po-Ren

    2012-09-01

    From 2000 to 2011, 8 patients with Streptococcus suis infections were identified in Taiwan. Six isolates were initially misidentified as Streptococcus acidominimus using commercial identification systems and later confirmed to be S. suis using 16S rRNA gene sequencing analysis. Among the 7 isolates available for further analysis, all belonged to biotype II. Three serotype I isolates possessed the same genotypes, indicating the possible clonal spread of S. suis. All of these patients survived. S. suis infection is underestimated in Taiwan. PMID:22705228

  6. Prophage lysin Ply30 protects mice from Streptococcus suis and Streptococcus equi subsp. zooepidemicus infections.

    PubMed

    Tang, Fang; Li, Dezhi; Wang, Haojin; Ma, Zhe; Lu, Chengping; Dai, Jianjun

    2015-11-01

    Streptococcus suis and Streptococcus equi subsp. zooepidemicus are capable of infecting humans and various animals, causing significant problems for the worldwide swine industry. As antibiotic resistance has increased, lysosomal enzymes encoded by phages have shown potential for use against pathogenic bacteria. In this study, a novel bacteriophage lysin, Ply30, encoded by the S. suis prophage phi30c, was recombinantly expressed and purified. Ply30 showed high bacteriolysis activity on S. suis and S. equi subsp. zooepidemicus in vitro. The ratio of the optical density at 600 nm (OD600) with treatment versus the OD600 with no treatment for most tested S. suis and S. equi subsp. zooepidemicus strains decreased from 1 to <0.3 and <0.5, respectively, within 1 h. The results of plate viability assays showed that treated bacteria suffered a 1- to 2-log decrease in CFU within 1 h. The optimal concentration of Ply30 was 50 μg/ml, and the optimal pH was 7. Moreover, Ply30 maintained high activity over a wide pH range (pH 6 to 10). The MICs of Ply30 against Streptococcus strains ranged from 16 to 512 μg/ml. In vivo, a 2-mg dose of Ply30 protected 90% (9/10 mice) of mice from infection with S. equi subsp. zooepidemicus and 80% (8/10 mice) of mice from infection with S. suis. Seven days after lysin Ply30 treatment, bacterial loads were significantly decreased in all tested organs and blood compared with those at 1 h postinfection without Ply30 treatment. Ply30 showed in vitro and in vivo antimicrobial efficiency and protected mice against two kinds of bacterial infections, indicating that Ply30 may be an effective therapeutic against streptococci. PMID:26253669

  7. Isolation of Streptococcus suis from 2 lambs with a history of lameness

    PubMed Central

    Muckle, Anne; López, Alfonso; Gottschalk, Marcelo; López-Méndez, Carlos; Giles, Jan; Lund, Lorraine; Saab, Matthew

    2014-01-01

    Streptococcus suis was isolated postmortem from 2 lambs with a history of lameness. Identity of S. suis was confirmed by species-specific polymerase chain reaction (PCR) and by 16S rRNA gene sequencing. One isolate was untypable by serotyping and non-encapsulated, while the other isolate was serotype 33. The lambs had come from the same farm, and there was no evidence of contact between the lambs and pigs. Although the natural niche for S. suis is considered to be the pig, a wide range of host species may be affected by this pathogen. PMID:25320381

  8. Draft genome sequences of nine Streptococcus suis strains isolated in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  9. Effect of Licochalcone A on Growth and Properties of Streptococcus suis

    PubMed Central

    Liu, Peng; Lv, Qingyu; Zeng, Xiaotao; jiang, Hua; Wang, Yanzi; Zheng, Xin; Zheng, Yuling; Li, Jianchun; Zhou, Xuyu; Jiang, Yongqiang

    2013-01-01

    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

  10. Suicin 3908, a New Lantibiotic Produced by a Strain of Streptococcus suis Serotype 2 Isolated from a Healthy Carrier Pig

    PubMed Central

    Vaillancourt, Katy; LeBel, Geneviève; Frenette, Michel; Gottschalk, Marcelo; Grenier, Daniel

    2015-01-01

    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. PMID:25659110

  11. Streptococcus suis causes septic arthritis and bacteremia: phenotypic characterization and molecular confirmation.

    PubMed

    Kim, Hanah; Lee, Sang Hoon; Moon, Hee-Won; Kim, Ji Young; Lee, Sun Hwa; Hur, Mina; Yun, Yeo-Min

    2011-04-01

    Streptococcus suis is a swine pathogen that causes meningitis, septicemia, pneumonia, and endocarditis. The first case of human S. suis infection was reported in Denmark in 1968, and since then, this infection with has been reported in many countries, especially in Southeast Asia because of the high density of pigs in this region. We report the case of a patient with septic arthritis and bacteremia caused by S. suis. Cases in which S. suis is isolated from the joint fluid are very rare, and to the best of our knowledge, this is first case report of S. suis infection in Korea. The identity of this organism was confirmed by phenotypic characterization and 16S rRNA sequence analysis. An 81-yr-old Korean woman who presented with fever, arthralgia, and headache was admitted to a secondary referral center in Korea. Culture of aspirated joint fluid and blood samples showed the growth of S. suis biotype II, which was identified by the Vitek2 GPI and API 20 Strep systems (bioMérieux, USA), and this organism was susceptible to penicillin G and vancomycin. The 16S rRNA sequences of the blood culture isolates showed 99% homology with those of S. suis subsp. suis, which are reported in GenBank. The patient's fever subsided, and blood and joint cultures were negative for bacterial growth after antibiotic therapy; however, the swelling and pain in her left knee joint persisted. She plans to undergo total knee replacement. PMID:21474987

  12. Streptococcus suis sequence type 7 outbreak, Sichuan, China.

    PubMed

    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; Xu, Jianguo

    2006-08-01

    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

  13. Prevalent distribution and conservation of Streptococcus suis Lmb protein and its protective capacity against the Chinese highly virulent strain infection.

    PubMed

    Zhang, Yan-Mei; Shao, Zhu-Qing; Wang, Jing; Wang, Ling; Li, Xianfu; Wang, Changjun; Tang, Jiaqi; Pan, Xiuzhen

    2014-01-01

    Streptococcus suis (S. suis) is an important zoonotic pathogen that causes multiple diseases in both pigs and humans. Many studies suggest that Streptococcus utilizes host extracellular matrix proteins, including laminin, for adhesion and invasion of host cells. Recently, we identified a putative Lmb protein (CDS 0330) of a highly virulent strain of S. suis (serotype 2). In this study, we characterized the ability of CDS 0330 to bind human laminin, and evaluated the protective efficacy of a recombinant protein vaccine. Bioinformatic analysis revealed that both the amino acid sequence and tertiary structure of CDS 0330 were similar to Lmb proteins in other Streptococcus. In addition, the sequence of CDS 0330 was present in the genomes of 26 of the 38 sequenced streptococci species, indicating an early origin and conservation of this gene. Particularly, all 17 sequenced S. suis genomes, regardless of serotype or geographic origin, contained CDS 0330 gene in their genome with a minimum pair-wise amino acid identity of 92%. PCR amplification revealed that CDS 0330 gene is distributed throughout 35 S. suis serotypes in the lmb-htp format. Flow cytometry analysis confirmed that CDS 0330 was expressed on the cell surface of S. suis, and ELISA revealed the recombinant CDS 0330 protein could bind laminin in vitro. Finally, vaccinating mice with recombinant CDS 0330 protein significantly prolonged survival after S. suis infection. Together, these data reveal that CDS 0330 is a laminin binding protein of S. suis 2, and open new avenues for preventing S. suis 2 infection. PMID:24120016

  14. Sub-MIC Tylosin Inhibits Streptococcus suis Biofilm Formation and Results in Differential Protein Expression

    PubMed Central

    Wang, Shuai; Yang, Yanbei; Zhao, Yulin; Zhao, Honghai; Bai, Jingwen; Chen, Jianqing; Zhou, Yonghui; Wang, Chang; Li, Yanhua

    2016-01-01

    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

  15. Sub-MIC Tylosin Inhibits Streptococcus suis Biofilm Formation and Results in Differential Protein Expression.

    PubMed

    Wang, Shuai; Yang, Yanbei; Zhao, Yulin; Zhao, Honghai; Bai, Jingwen; Chen, Jianqing; Zhou, Yonghui; Wang, Chang; Li, Yanhua

    2016-01-01

    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

  16. Population Structure and Antimicrobial Resistance Profiles of Streptococcus suis Serotype 2 Sequence Type 25 Strains

    PubMed Central

    Athey, Taryn B. T.; Teatero, Sarah; Takamatsu, Daisuke; Wasserscheid, Jessica; Dewar, Ken; Gottschalk, Marcelo; Fittipaldi, Nahuel

    2016-01-01

    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

  17. The CodY regulator is essential for virulence in Streptococcus suis serotype 2

    PubMed Central

    Feng, Liping; Zhu, Jiawen; Chang, Haitao; Gao, Xiaoping; Gao, Cheng; Wei, Xiaofeng; Yuan, Fangyan; Bei, Weicheng

    2016-01-01

    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

  18. The CodY regulator is essential for virulence in Streptococcus suis serotype 2.

    PubMed

    Feng, Liping; Zhu, Jiawen; Chang, Haitao; Gao, Xiaoping; Gao, Cheng; Wei, Xiaofeng; Yuan, Fangyan; Bei, Weicheng

    2016-01-01

    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

  19. Antimicrobial susceptibility of Streptococcus suis isolated from clinically healthy swine in Brazil

    PubMed Central

    Soares, Taíssa Cook Siqueira; Paes, Antonio Carlos; Megid, Jane; Ribolla, Paulo Eduardo Martins; Paduan, Karina dos Santos; Gottschalk, Marcelo

    2014-01-01

    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

  20. Antimicrobial susceptibility of Streptococcus suis isolated from clinically healthy swine in Brazil.

    PubMed

    Soares, Taíssa Cook Siqueira; Paes, Antonio Carlos; Megid, Jane; Ribolla, Paulo Eduardo Martins; Paduan, Karina dos Santos; Gottschalk, Marcelo

    2014-04-01

    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

  1. Streptococcus suis infection in swine. A sixteen month study.

    PubMed

    Higgins, R; Gottschalk, M; Mittal, K R; Beaudoin, M

    1990-01-01

    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

  2. Role of Capsule and Suilysin in Mucosal Infection of Complement-Deficient Mice with Streptococcus suis

    PubMed Central

    Seitz, Maren; Beineke, Andreas; Singpiel, Alena; Willenborg, Jörg; Dutow, Pavel; Goethe, Ralph; Valentin-Weigand, Peter; Klos, Andreas

    2014-01-01

    Virulent Streptococcus suis serotype 2 strains are invasive extracellular bacteria causing septicemia and meningitis in piglets and humans. One objective of this study was to elucidate the function of complement in innate immune defense against S. suis. Experimental infection of wild-type (WT) and C3−/− mice demonstrated for the first time that the complement system protects naive mice against invasive mucosal S. suis infection. S. suis WT but not an unencapsulated mutant caused mortality associated with meningitis and other pathologies in C3−/− mice. The capsule contributed also substantially to colonization of the upper respiratory tract. Experimental infection of C3−/− mice with a suilysin mutant indicated that suilysin expression facilitated an early disease onset and the pathogenesis of meningitis. Flow cytometric analysis revealed C3 antigen deposition on the surface of ca. 40% of S. suis WT bacteria after opsonization with naive WT mouse serum, although to a significantly lower intensity than on the unencapsulated mutant. Ex vivo multiplication in murine WT and C3−/− blood depended on capsule but not suilysin expression. Interestingly, S. suis invasion of inner organs was also detectable in C5aR−/− mice, suggesting that chemotaxis and activation of immune cells via the anaphylatoxin receptor C5aR is, in addition to opsonization, a further important function of the complement system in defense against mucosal S. suis infection. In conclusion, we unequivocally demonstrate here the importance of complement against mucosal S. suis serotype 2 infection and that the capsule of this pathogen is also involved in escape from complement-independent immunity. PMID:24686060

  3. Recruitment of Factor H to the Streptococcus suis Cell Surface is Multifactorial.

    PubMed

    Roy, David; Grenier, Daniel; Segura, Mariela; Mathieu-Denoncourt, Annabelle; Gottschalk, Marcelo

    2016-01-01

    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

  4. Streptococcus suis Meningitis: A Systematic Review and Meta-analysis

    PubMed Central

    van Samkar, Anusha; Brouwer, Matthijs C.; Schultsz, Constance; van der Ende, Arie; van de Beek, Diederik

    2015-01-01

    Background Streptococcus suis is the most common cause of meningitis in pork consuming and pig rearing countries in South-East Asia. We performed a systematic review of studies on S. suis meningitis to define the clinical characteristics, predisposing factors and outcome. Methodology Studies published between January 1, 1980 and August 1, 2015 were identified from main literature databases and reference lists. Studies were included if they were written in West-European languages and described at least 5 adult patients with S. suis meningitis in whom at least one clinical characteristic was described. Findings We identified 913 patients with S. suis meningitis included in 24 studies between 1980 and 2015. The mean age was 49 years and 581 of 711 patients were male (82%). Exposure to pigs or pork was present in 395 of 648 patients (61%) while other predisposing factors were less common. 514 of 528 patients presented with fever (97%), 429 of 451 with headache (95%), 462 of 496 with neck stiffness (93%) and 78 of 384 patients (20%) had a skin injury in the presence of pig/pork contact. The case fatality rate was 2.9% and hearing loss was a common sequel occurring in 259 of 489 patients (53%). Treatment included dexamethasone in 157 of 300 (52%) of patients and was associated with reduced hearing loss in S. suis meningitis patients included in a randomized controlled trial. Conclusion S. suis meningitis has a clear association with pig and pork contact. Mortality is low, but hearing loss occurs frequently. Dexamethasone was shown to reduce hearing loss. PMID:26505485

  5. Impact of Sub-Inhibitory Concentrations of Amoxicillin on Streptococcus suis Capsule Gene Expression and Inflammatory Potential

    PubMed Central

    Haas, Bruno; Grenier, Daniel

    2016-01-01

    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

  6. Characterization of DNase activity and gene in Streptococcus suis and evidence for a role as virulence factor

    PubMed Central

    2014-01-01

    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

  7. Identification of a Novel Host-Specific IgM Protease in Streptococcus suis

    PubMed Central

    Seele, Jana; Singpiel, Alena; Spoerry, Christian; von Pawel-Rammingen, Ulrich; Valentin-Weigand, Peter

    2013-01-01

    Streptococcus suis serotype 2 is a highly invasive, extracellular pathogen in pigs with the capacity to cause severe infections in humans. This study was initiated by the finding that IgM degradation products are released after opsonization of S. suis. The objective of this work was to identify the bacterial factor responsible for IgM degradation. The results of this study showed that a member of the IdeS family, designated IdeSsuis (Immunoglobulin M-degrading enzyme of S. suis), is responsible and sufficient for IgM cleavage. Recombinant IdeSsuis was found to degrade only IgM but neither IgG nor IgA. Interestingly, Western blot analysis revealed that IdeSsuis is host specific, as it exclusively cleaves porcine IgM but not IgM from six other species, including a closely related member of the Suidae family. As demonstrated by flow cytometry and immunofluorescence microscopy, IdeSsuis modulates binding of IgM to the bacterial surface. IdeSsuis is the first prokaryotic IgM-specific protease described, indicating that this enzyme is involved in a so-far-unknown mechanism of host-pathogen interaction at an early stage of the host immune response. Furthermore, cleavage of porcine IgM by IdeSsuis is the first identified phenotype reflecting functional adaptation of S. suis to pigs as the main host. PMID:23243300

  8. Epidemiology, Clinical Manifestations, and Outcomes of Streptococcus suis Infection in Humans

    PubMed Central

    Huong, Vu Thi Lan; Ha, Ngo; Huy, Nguyen Tien; Horby, Peter; Nghia, Ho Dang Trung; Thiem, Vu Dinh; Zhu, Xiaotong; Hoa, Ngo Thi; Hien, Tran Tinh; Zamora, Javier; Schultsz, Constance; Wertheim, Heiman Frank Louis

    2014-01-01

    Streptococcus suis, a bacterium that affects pigs, is a neglected pathogen that causes systemic disease in humans. We conducted a systematic review and meta-analysis to summarize global estimates of the epidemiology, clinical characteristics, and outcomes of this zoonosis. We searched main literature databases for all studies through December 2012 using the search term “streptococcus suis.” The prevalence of S. suis infection is highest in Asia; the primary risk factors are occupational exposure and eating of contaminated food. The pooled proportions of case-patients with pig-related occupations and history of eating high-risk food were 38.1% and 37.3%, respectively. The main clinical syndrome was meningitis (pooled rate 68.0%), followed by sepsis, arthritis, endocarditis, and endophthalmitis. The pooled case-fatality rate was 12.8%. Sequelae included hearing loss (39.1%) and vestibular dysfunction (22.7%). Our analysis identified gaps in the literature, particularly in assessing risk factors and sequelae of this infection. PMID:24959701

  9. Two Spx Regulators Modulate Stress Tolerance and Virulence in Streptococcus suis Serotype 2

    PubMed Central

    Zheng, Chengkun; Xu, Jiali; Li, Jinquan; Hu, Luohong; Xia, Jiandong; Fan, Jingyan; Guo, Weina; Chen, Huanchun; Bei, Weicheng

    2014-01-01

    Streptococcus suis serotype 2 is an important zoonotic pathogen causing severe infections in pigs and humans. The pathogenesis of S. suis 2 infections, however, is still poorly understood. Spx proteins are a group of global regulators involved in stress tolerance and virulence. In this study, we characterized two orthologs of the Spx regulator, SpxA1 and SpxA2 in S. suis 2. Two mutant strains (ΔspxA1 and ΔspxA2) lacking the spx genes were constructed. The ΔspxA1 and ΔspxA2 mutants displayed different phenotypes. ΔspxA1 exhibited impaired growth in the presence of hydrogen peroxide, while ΔspxA2 exhibited impaired growth in the presence of SDS and NaCl. Both mutants were defective in medium lacking newborn bovine serum. Using a murine infection model, we demonstrated that the abilities of the mutant strains to colonize the tissues were significantly reduced compared to that of the wild-type strain. The mutant strains also showed a decreased level of survival in pig blood. Microarray analysis revealed a global regulatory role for SpxA1 and SpxA2. Furthermore, we demonstrated for the first time that Spx is involved in triggering the host inflammatory response. Collectively, our data suggest that SpxA1 and SpxA2 are global regulators that are implicated in stress tolerance and virulence in S. suis 2. PMID:25264876

  10. Streptococcus suis sorption on agricultural soils: role of soil physico-chemical properties.

    PubMed

    Zhao, Wenqiang; Liu, Xing; Huang, Qiaoyun; Cai, Peng

    2015-01-01

    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. PMID:24968305

  11. Streptococcus suis Capsular Polysaccharide Inhibits Phagocytosis through Destabilization of Lipid Microdomains and Prevents Lactosylceramide-Dependent Recognition

    PubMed Central

    Houde, Mathieu; Gottschalk, Marcelo; Gagnon, Fleur; Van Calsteren, Marie-Rose

    2012-01-01

    Streptococcus suis type 2 is a major swine pathogen and a zoonotic agent, causing meningitis in both swine and humans. S. suis infects the host through the respiratory route, reaches the bloodstream, and persists until breaching into the central nervous system. The capsular polysaccharide (CPS) of S. suis type 2 is considered a key virulence factor of the bacteria. Though CPS allows S. suis to adhere to the membrane of cells of the immune system, it provides protection against phagocytosis. In fact, nonencapsulated mutants are easily internalized and killed by macrophages and dendritic cells. The objective of this work was to study the molecular mechanisms by which the CPS of S. suis prevents phagocytosis. By using latex beads covalently linked with purified CPS, it was shown that CPS itself was sufficient to inhibit entry of both latex beads and bystander fluorescent beads into macrophages. Upon contact with macrophages, encapsulated S. suis was shown to destabilize lipid microdomains at the cell surface, to block nitric oxide (NO) production during infection, and to prevent lactosylceramide accumulation at the phagocytic cup during infection. In contrast, the nonencapsulated mutant was easily internalized via lipid rafts, in a filipin-sensitive manner, leading to lactosylceramide recruitment and strong NO production. This is the first report to identify a role for CPS in lipid microdomain stability and to recognize an interaction between S. suis and lactosylceramide in phagocytes. PMID:22124659

  12. Astrocytes Enhance Streptococcus suis-Glial Cell Interaction in Primary Astrocyte-Microglial Cell Co-Cultures

    PubMed Central

    Seele, Jana; Nau, Roland; Prajeeth, Chittappen K.; Stangel, Martin; Valentin-Weigand, Peter; Seitz, Maren

    2016-01-01

    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. PMID:27304968

  13. Astrocytes Enhance Streptococcus suis-Glial Cell Interaction in Primary Astrocyte-Microglial Cell Co-Cultures.

    PubMed

    Seele, Jana; Nau, Roland; Prajeeth, Chittappen K; Stangel, Martin; Valentin-Weigand, Peter; Seitz, Maren

    2016-01-01

    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. PMID:27304968

  14. Evaluation of the protective efficacy of four novel identified membrane associated proteins of Streptococcus suis serotype 2.

    PubMed

    Zhou, Yang; Wang, Yan; Deng, Limei; Zheng, Chengkun; Yuan, Fangyan; Chen, Huanchun; Bei, Weicheng; Li, Jinquan

    2015-05-01

    Streptococcus suis serotype 2 (S. suis 2) is an important zoonotic pathogen that can also cause epidemics of life-threatening infections in humans. Surface proteins of pathogens play a critical role in the interaction with host system or environment, as they take part in processes like virulence, cytotoxicity, adhesion, signaling or transport, etc. Thus, surface proteins identified by the screening of immunoproteomic techniques are promising vaccine candidates or diagnostic markers. In this study, four membrane associated proteins (MAP) identified by immunoproteomic method were cloned and expressed as recombinant proteins with his-tag. Screening for vaccine candidates were firstly performed by protection assay in vivo and immunization with Sbp markedly protected mice against systemic S. suis 2 infection. The immune responses and protective of Sbp were further evaluated. The results showed that Sbp could elicit a strong humoral antibody response and protect mice from lethal challenge with S. suis 2. The antiserum against Sbp could efficiently impede survival of bacterial in whole blood killing assay and conferred significant protection against S. suis 2 infection in passive immunization assays. The findings indicate that Sbp may serve as an important factor in the pathogenesis of S. suis 2 and would be a promising subunit vaccine candidate. PMID:25820064

  15. Species-specific real-time PCR assay for the detection of Streptococcus suis from clinical specimens.

    PubMed

    Srinivasan, Velusamy; McGee, Lesley; Njanpop-Lafourcade, Berthe-Marie; Moïsi, Jennifer; Beall, Bernard

    2016-06-01

    A real-time polymerase chain reaction was developed to detect all known strains of Streptococcus suis. The assay was highly specific, and sensitivity was <10 copies/assay for S. suis detection from clinical samples. PMID:27041105

  16. Identification of Streptococcus suis Meningitis through Population-Based Surveillance, Togo, 2010–2014

    PubMed Central

    Tall, Haoua; Njanpop-Lafourcade, Berthe-Marie; Mounkoro, Didier; Tidjani, Loukoumane; Agbenoko, Kodjo; Alassani, Issifou; Amidou, Moussa; Tamekloe, Stanislas; Laing, Kenneth G.; Witney, Adam A.; Hinds, Jason; van der Linden, Mark P.G.; Gessner, Bradford D.

    2016-01-01

    During 2010–2014, we enrolled 511 patients with suspected bacterial meningitis into surveillance in 2 districts of northern Togo. We identified 15 persons with Streptococcus suis infection; 10 had occupational contact with pigs, and 12 suffered neurologic sequelae. S. suis testing should be considered in rural areas of the African meningitis belt. PMID:27314251

  17. Identification of Streptococcus suis Meningitis through Population-Based Surveillance, Togo, 2010-2014.

    PubMed

    Tall, Haoua; Njanpop-Lafourcade, Berthe-Marie; Mounkoro, Didier; Tidjani, Loukoumane; Agbenoko, Kodjo; Alassani, Issifou; Amidou, Moussa; Tamekloe, Stanislas; Laing, Kenneth G; Witney, Adam A; Hinds, Jason; van der Linden, Mark P G; Gessner, Bradford D; Moïsi, Jennifer C

    2016-07-01

    During 2010-2014, we enrolled 511 patients with suspected bacterial meningitis into surveillance in 2 districts of northern Togo. We identified 15 persons with Streptococcus suis infection; 10 had occupational contact with pigs, and 12 suffered neurologic sequelae. S. suis testing should be considered in rural areas of the African meningitis belt. PMID:27314251

  18. Streptococcus suis infection in Hong Kong: an emerging infectious disease?

    PubMed Central

    MA, E.; CHUNG, P. H.; SO, T.; WONG, L.; CHOI, K. M.; CHEUNG, D. T.; KAM, K. M.; CHUANG, S. K.; TSANG, T.

    2008-01-01

    SUMMARY We conducted a 31-month retrospective review of all laboratory-confirmed Streptococcus suis infections admitted to public hospitals in Hong Kong. Strain identification, serotyping and antibiotic susceptibility tests were conducted on S. suis isolates. Twenty-one sporadic cases were identified, comprising 18 (86%) males and 3 (14%) females. About half were patients aged ⩾65 years. More cases occurred during summer. Occupational exposure was documented in five (24%) cases. The estimated annual incidence was 0·09/100 000 in the general population and 32/100 000 in people with occupational exposure to pigs and raw pork. The primary clinical manifestations were meningitis (48%), septicaemia (38%) and endocarditis (14%). The case-fatality rate was 5%. All available isolates from 15 patients were serotype 2, sensitive to penicillin, ampicillin, ceftriaxone, but resistant to tetracycline. Injury prevention and proper handling of pigs or raw pork should be advocated to both at-risk occupational groups and the general population. PMID:18252026

  19. Streptococcus suis in invasive human infections in Poland: clonality and determinants of virulence and antimicrobial resistance.

    PubMed

    Bojarska, A; Molska, E; Janas, K; Skoczyńska, A; Stefaniuk, E; Hryniewicz, W; Sadowy, E

    2016-06-01

    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. PMID:26980093

  20. The arginine-ornithine antiporter ArcD contributes to biological fitness of Streptococcus suis

    PubMed Central

    Fulde, Marcus; Willenborg, Joerg; Huber, Claudia; Hitzmann, Angela; Willms, Daniela; Seitz, Maren; Eisenreich, Wolfgang; Valentin-Weigand, Peter; Goethe, Ralph

    2014-01-01

    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

  1. Genetic diversity of Streptococcus suis serotype 2 isolated from pigs in Brazil.

    PubMed

    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

    2016-04-01

    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

  2. [Streptococcus pyogenes pathogenic factors].

    PubMed

    Bidet, Ph; Bonacorsi, S

    2014-11-01

    The pathogenicity of ß-hemolytic group A streptococcus (GAS) is particularly diverse, ranging from mild infections, such as pharyngitis or impetigo, to potentially debilitating poststreptococcal diseases, and up to severe invasive infections such as necrotizing fasciitis or the dreaded streptococcal toxic shock syndrome. This variety of clinical expressions, often radically different in individuals infected with the same strain, results from a complex interaction between the bacterial virulence factors, the mode of infection and the immune system of the host. Advances in comparative genomics have led to a better understanding of how, following this confrontation, GAS adapts to the immune system's pressure, either peacefully by reducing the expression of certain virulence factors to achieve an asymptomatic carriage, or on the contrary, by overexpressing them disproportionately, resulting in the most severe forms of invasive infection. PMID:25456681

  3. Isolation and characterization of a native avirulent strain of Streptococcus suis serotype 2: a perspective for vaccine development

    PubMed Central

    Yao, Xinyue; Li, Ming; Wang, Jing; Wang, Changjun; Hu, Dan; Zheng, Feng; Pan, Xiuzhen; Tan, Yinling; Zhao, Yan; Hu, Liwen; Tang, Jiaqi; Hu, Fuquan

    2015-01-01

    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

  4. (p)ppGpp synthetases regulate the pathogenesis of zoonotic Streptococcus suis.

    PubMed

    Zhu, Jiawen; Zhang, Tengfei; Su, Zhipeng; Li, Lu; Wang, Dong; Xiao, Ran; Teng, Muye; Tan, Meifang; Zhou, Rui

    2016-10-01

    (p)ppGpp-mediated stringent response is one of the main adaption mechanism in bacteria, and the ability to adapt to environment is linked to the pathogenesis of bacterial pathogens. In the zoonotic pathogen Streptococcus suis, there are two (p)ppGpp synthetases, RelA and RelQ. To investigate the regulatory functions of (p)ppGpp/(p)ppGpp synthetases on the pathogenesis of S. suis, the phenotypes of the [(p)ppGpp(0)] mutant ΔrelAΔrelQ and its parental strain were compared. Light and electron microscopy observation showed that the mutant strain had a longer chain-length than its parental strain. Disruption of relA and relQ led to decreased adhesive and invasive ability to HEp-2 cells, and increased sensitivity to the blood killing and phagocytosis. Mouse infection experiments showed that the mutant strain was attenuated and easier to be cleaned up in vivo. Quantitative reverse transcription PCR (qRT-PCR) analysis indicated that the expressions of virulence related genes involving in morphology and virulence were down-regulated in the mutant strain. Our study demonstrated that the (p)ppGpp synthetases or (p)ppGpp can regulate the pathogenesis of this important zoonotic pathogen. PMID:27524648

  5. Subtilisin-like protease-1 secreted through type IV secretion system contributes to high virulence of Streptococcus suis 2.

    PubMed

    Yin, Supeng; Li, Ming; Rao, Xiancai; Yao, Xinyue; Zhong, Qiu; Wang, Min; Wang, Jing; Peng, Yizhi; Tang, Jiaqi; Hu, Fuquan; Zhao, Yan

    2016-01-01

    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

  6. Temporal and spatial association of Streptococcus suis infection in humans and porcine reproductive and respiratory syndrome outbreaks in pigs in northern Vietnam.

    PubMed

    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

    2016-01-01

    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. PMID:25997360

  7. Clinical resistance and decreased susceptibility in Streptococcus suis isolates from clinically healthy fattening pigs.

    PubMed

    Callens, Bénédicte F; Haesebrouck, Freddy; Maes, Dominiek; Butaye, Patrick; Dewulf, Jeroen; Boyen, Filip

    2013-04-01

    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

  8. Subtilisin-like protease-1 secreted through type IV secretion system contributes to high virulence of Streptococcus suis 2

    PubMed Central

    Yin, Supeng; Li, Ming; Rao, Xiancai; Yao, Xinyue; Zhong, Qiu; Wang, Min; Wang, Jing; Peng, Yizhi; Tang, Jiaqi; Hu, Fuquan; Zhao, Yan

    2016-01-01

    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

  9. The orphan response regulator CovR: a globally negative modulator of virulence in Streptococcus suis serotype 2.

    PubMed

    Pan, Xiuzhen; Ge, Junchao; Li, Ming; Wu, Bo; Wang, Changjun; Wang, Jing; Feng, Youjun; Yin, Zhimin; Zheng, Feng; Cheng, Gong; Sun, Wen; Ji, Hongfeng; Hu, Dan; Shi, Peiju; Feng, Xiaodan; Hao, Xina; Dong, Ruiping; Hu, Fuquan; Tang, Jiaqi

    2009-04-01

    Streptococcus suis serotype 2 is an emerging zoonotic pathogen responsible for a wide range of life-threatening diseases in pigs and humans. However, the pathogenesis of S. suis serotype 2 infection is not well understood. In this study, we report that an orphan response regulator, CovR, globally regulates gene expression and negatively controls the virulence of S. suis 05ZYH33, a streptococcal toxic shock syndrome (STSS)-causing strain. A covR-defective (DeltacovR) mutant of 05ZYH33 displayed dramatic phenotypic changes, such as formation of longer chains, production of thicker capsules, and increased hemolytic activity. Adherence of the DeltacovR mutant to epithelial cells was greatly increased, and its resistance to phagocytosis and killing by neutrophils and monocytes was also significantly enhanced. More importantly, inactivation of covR increased the lethality of S. suis serotype 2 in experimental infection of piglets, and this phenotype was restored by covR complementation. Colonization experiments also showed that the DeltacovR mutant exhibited an increased ability to colonize susceptible tissues of piglets. The pleiotropic phenotype of the DeltacovR mutant is in full agreement with the large number of genes controlled by CovR as revealed by transcription profile analysis: 2 genes are positively regulated, and 193 are repressed, including many that encode known or putative virulence factors. These findings suggested that CovR is a global repressor in virulence regulation of STSS-causing S. suis serotype 2. PMID:19181815

  10. An emerging zoonotic clone in the Netherlands provides clues to virulence and zoonotic potential of Streptococcus suis.

    PubMed

    Willemse, N; Howell, K J; Weinert, L A; Heuvelink, A; Pannekoek, Y; Wagenaar, J A; Smith, H E; van der Ende, A; Schultsz, C

    2016-01-01

    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

  11. An emerging zoonotic clone in the Netherlands provides clues to virulence and zoonotic potential of Streptococcus suis

    PubMed Central

    Willemse, N.; Howell, K. J.; Weinert, L. A.; Heuvelink, A.; Pannekoek, Y.; Wagenaar, J. A.; Smith, H. E.; van der Ende, A.; Schultsz, C.

    2016-01-01

    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

  12. Purification and Characterization of Suicin 65, a Novel Class I Type B Lantibiotic Produced by Streptococcus suis

    PubMed Central

    Vaillancourt, Katy; LeBel, Geneviève; Frenette, Michel; Fittipaldi, Nahuel; Gottschalk, Marcelo; Grenier, Daniel

    2015-01-01

    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

  13. Protection against Streptococcus suis Serotype 2 Infection Using a Capsular Polysaccharide Glycoconjugate Vaccine.

    PubMed

    Goyette-Desjardins, Guillaume; Calzas, Cynthia; Shiao, Tze Chieh; Neubauer, Axel; Kempker, Jennifer; Roy, René; Gottschalk, Marcelo; Segura, Mariela

    2016-07-01

    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

  14. Slaughterhouse Pigs Are a Major Reservoir of Streptococcus suis Serotype 2 Capable of Causing Human Infection in Southern Vietnam

    PubMed Central

    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

    2011-01-01

    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

  15. MsmK, an ATPase, Contributes to Utilization of Multiple Carbohydrates and Host Colonization of Streptococcus suis

    PubMed Central

    Tan, Mei-Fang; Gao, Ting; Liu, Wan-Quan; Zhang, Chun-Yan; Yang, Xi; Zhu, Jia-Wen; Teng, Mu-Ye; Li, Lu; Zhou, Rui

    2015-01-01

    Acquisition and metabolism of carbohydrates are essential for host colonization and pathogenesis of bacterial pathogens. Different bacteria can uptake different lines of carbohydrates via ABC transporters, in which ATPase subunits energize the transport though ATP hydrolysis. Some ABC transporters possess their own ATPases, while some share a common ATPase. Here we identified MsmK, an ATPase from Streptococcus suis, an emerging zoonotic bacterium causing dead infections in pigs and humans. Genetic and biochemistry studies revealed that the MsmK was responsible for the utilization of raffinose, melibiose, maltotetraose, glycogen and maltotriose. In infected mice, the msmK-deletion mutant showed significant defects of survival and colonization when compared with its parental and complementary strains. Taken together, MsmK is an ATPase that contributes to multiple carbohydrates utilization and host colonization of S. suis. This study gives new insight into our understanding of the carbohydrates utilization and its relationship to the pathogenesis of this zoonotic pathogen. PMID:26222651

  16. Crystallization and preliminary crystallographic analysis of recombinant immunoglobulin G-binding protein from Streptococcus suis

    SciTech Connect

    Khan, Abdul Hamid; Chu, Fuliang; Feng, Youjun; Zhang, Qinagmin; Qi, Jianxun; Gao, George Fu

    2008-08-01

    Crystallization of recombinant IgG-binding protein expressed in Escherichia coli using the hanging-drop vapour-diffusion method is described. The crystals belonged to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 38.98, b = 43.94, c = 78.17 Å. Streptococcus suis, an important zoonotic pathogen, expresses immunoglobulin G-binding protein, which is thought to be helpful to the organism in eluding the host defence system. Recombinant IgG-binding protein expressed in Escherichia coli has been crystallized using the hanging-drop vapour-diffusion method. The crystals belonged to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 38.98, b = 43.94, c = 78.17 Å and one molecule in the asymmetric unit. Diffraction data were collected to 2.60 Å resolution.

  17. Functional and Structural Characterization of the Antiphagocytic Properties of a Novel Transglutaminase from Streptococcus suis*

    PubMed Central

    Yu, Jie; Pian, Yaya; Ge, Jingpeng; Guo, Jie; Zheng, Yuling; Jiang, Hua; Hao, Huaijie; Yuan, Yuan; Jiang, Yongqiang; Yang, Maojun

    2015-01-01

    Streptococcus suis serotype 2 (Ss2) is an important swine and human zoonotic pathogen. In the present study, we identified a novel secreted immunogenic protein, SsTGase, containing a highly conserved eukaryotic-like transglutaminase (TGase) domain at the N terminus. We found that inactivation of SsTGase significantly reduced the virulence of Ss2 in a pig infection model and impaired its antiphagocytosis in human blood. We further solved the crystal structure of the N-terminal portion of the protein in homodimer form at 2.1 Å. Structure-based mutagenesis and biochemical studies suggested that disruption of the homodimer directly resulted in the loss of its TGase activity and antiphagocytic ability. Characterization of SsTGase as a novel virulence factor of Ss2 by acting as a TGase would be beneficial for developing new therapeutic agents against Ss2 infections. PMID:26085092

  18. A novel suicide shuttle plasmid for Streptococcus suis serotype 2 and Streptococcus equi ssp. zooepidemicus gene mutation

    PubMed Central

    Liu, Rui; Zhang, Ping; Su, Yiqi; Lin, Huixing; Zhang, Hui; Yu, Lei; Ma, Zhe; Fan, Hongjie

    2016-01-01

    The mariner-based Himar1 system has been utilized for creating mutant libraries of many Gram-positive bacteria. Streptococcus suis serotype 2 (SS2) and Streptococcus equi ssp. zooepidemicus (SEZ) are primary pathogens of swine that threaten the swine industry in China. To provide a forward-genetics technology for finding virulent phenotype-related genes in these two pathogens, we constructed a novel temperature-sensitive suicide shuttle plasmid, pMar4s, which contains the Himar1 system transposon, TnYLB-1, and the Himar1 C9 transposase from pMarA and the repTAs temperature-sensitive fragment from pSET4s. The kanamycin (Kan) resistance gene was in the TnYLB-1 transposon. Temperature sensitivity and Kan resistance allowed the selection of mutant strains and construction of the mutant library. The SS2 and SEZ mutant libraries were successfully constructed using the pMar4s plasmid. Inverse-Polymerase Chain Reaction (Inverse-PCR) results revealed large variability in transposon insertion sites and that the library could be used for phenotype alteration screening. The thiamine biosynthesis gene apbE was screened for its influence on SS2 anti-phagocytosis; likewise, the sagF gene was identified to be a hemolytic activity-related gene in SEZ. pMar4s was suitable for mutant library construction, providing more information regarding SS2 and SEZ virulence factors and illustrating the pathogenesis of swine streptococcosis. PMID:27256117

  19. A novel suicide shuttle plasmid for Streptococcus suis serotype 2 and Streptococcus equi ssp. zooepidemicus gene mutation.

    PubMed

    Liu, Rui; Zhang, Ping; Su, Yiqi; Lin, Huixing; Zhang, Hui; Yu, Lei; Ma, Zhe; Fan, Hongjie

    2016-01-01

    The mariner-based Himar1 system has been utilized for creating mutant libraries of many Gram-positive bacteria. Streptococcus suis serotype 2 (SS2) and Streptococcus equi ssp. zooepidemicus (SEZ) are primary pathogens of swine that threaten the swine industry in China. To provide a forward-genetics technology for finding virulent phenotype-related genes in these two pathogens, we constructed a novel temperature-sensitive suicide shuttle plasmid, pMar4s, which contains the Himar1 system transposon, TnYLB-1, and the Himar1 C9 transposase from pMarA and the repTAs temperature-sensitive fragment from pSET4s. The kanamycin (Kan) resistance gene was in the TnYLB-1 transposon. Temperature sensitivity and Kan resistance allowed the selection of mutant strains and construction of the mutant library. The SS2 and SEZ mutant libraries were successfully constructed using the pMar4s plasmid. Inverse-Polymerase Chain Reaction (Inverse-PCR) results revealed large variability in transposon insertion sites and that the library could be used for phenotype alteration screening. The thiamine biosynthesis gene apbE was screened for its influence on SS2 anti-phagocytosis; likewise, the sagF gene was identified to be a hemolytic activity-related gene in SEZ. pMar4s was suitable for mutant library construction, providing more information regarding SS2 and SEZ virulence factors and illustrating the pathogenesis of swine streptococcosis. PMID:27256117

  20. Binding properties of Streptococcus suis for immunoglobulin G and other plasma proteins.

    PubMed

    Salasia, S I; Lämmler, C

    1996-10-01

    Immunoglobulin G (IgG) binding proteins on the surface of Streptococcus suis could be readily detected by direct cultivation of the bacteria on nitrocellulose membranes and subsequent treatment of the membranes with human IgG. Among the 75 S. suis isolates tested two cultures (S. suis P43, S. suis P143) caused a blue colouration of the membranes indicating IgG binding activities. The IgG binding proteins could be solubilized by heat treatment of the bacteria at an acid pH and also by mutanolysin treatment. Western blot analysis revealed numerous protein bands with IgG binding activities. The IgG binding proteins were also released into the culture supernatant of the bacteria. This could be detected for 51 of the 75 S. suis using a microfiltration assay. In binding studies with 125I-IgG S. suis P43 and S. suis P143 but none of the other S. suis isolates showed a significant binding of the protein. These two cultures additionally bound 125I-albumin, 125I-alpha 2-macroglobulin and 125I-fibrinogen all from humans but not 125I-chicken IgG or 125I-human haptoglobin 2-1. The binding profiles of the two S. suis cultures tested indicate a close relation of these binding proteins with streptococcal protein G. PMID:8921739

  1. An occurrence of equine transport pneumonia caused by mixed infection with Pasteurella caballi, Streptococcus suis and Streptococcus zooepidemicus.

    PubMed

    Hayakawa, Y; Komae, H; Ide, H; Nakagawa, H; Yoshida, Y; Kamada, M; Kataoka, Y; Nakazawa, M

    1993-06-01

    An acute death occurred in a racehorse with pneumonia after long-distance transportation in December, 1990. Pasteurella caballi, Streptococcus suis and Streptococcus zooepidemicus were isolated from the lung at high rate. Specific antigens of these bacteria were also demonstrated immunohistologically in the pneumonic lesion. These findings indicated that the disease is equine transport pneumonia caused by a mixed infection of the three bacterial species. This is the first report on the isolation of P. caballi and S. suis from a racehorse in Japan. PMID:8357920

  2. Streptococcus suis Serotypes Characterized by Analysis of Chaperonin 60 Gene Sequences

    PubMed Central

    Brousseau, Ronald; Hill, Janet E.; Préfontaine, Gabrielle; Goh, Swee-Han; Harel, Josée; Hemmingsen, Sean M.

    2001-01-01

    Streptococcus suis is an important pathogen of swine which occasionally infects humans as well. There are 35 serotypes known for this organism, and it would be desirable to develop rapid methods methods to identify and differentiate the strains of this species. To that effect, partial chaperonin 60 gene sequences were determined for the 35 serotype reference strains of S. suis. Analysis of a pairwise distance matrix showed that the distances ranged from 0 to 0.275 when values were calculated by the maximum-likelihood method. For five of the strains the distances from serotype 1 were greater than 0.1, and for two of these strains the distances were were more than 0.25, suggesting that they belong to a different species. Most of the nucleotide differences were silent; alignment of protein sequences showed that there were only 11 distinct sequences for the 35 strains under study. The chaperonin 60 gene phylogenetic tree was similar to the previously published tree based on 16S rRNA sequences, and it was also observed that strains with identical chaperonin 60 gene sequences tended to have identical 16S rRNA sequences. The chaperonin 60 gene sequences provided a higher level of discrimination between serotypes than the 16S RNA sequences provided and could form the basis for a diagnostic protocol. PMID:11571190

  3. Antimicrobial Resistance Profile and Genotypic Characteristics of Streptococcus suis Capsular Type 2 Isolated from Clinical Carrier Sows and Diseased Pigs in China.

    PubMed

    Zhang, Chunping; Zhang, Zhongqiu; Song, Li; Fan, Xuezheng; Wen, Fang; Xu, Shixin; Ning, Yibao

    2015-01-01

    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

  4. Antimicrobial Resistance Profile and Genotypic Characteristics of Streptococcus suis Capsular Type 2 Isolated from Clinical Carrier Sows and Diseased Pigs in China

    PubMed Central

    Zhang, Chunping; Zhang, Zhongqiu; Song, Li; Fan, Xuezheng; Wen, Fang; Xu, Shixin; Ning, Yibao

    2015-01-01

    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

  5. Fisher scientific award lecture - the capsular polysaccharides of Group B Streptococcus and Streptococcus suis differently modulate bacterial interactions with dendritic cells.

    PubMed

    Segura, Mariela

    2012-03-01

    Infections with encapsulated bacteria cause serious clinical problems. Besides being poorly immunogenic, the bacterial capsular polysaccharide (CPS) cloaks antigenic proteins, allowing bacterial evasion of the host immune system. Despite the clinical significance of bacterial CPS and its suggested role in the pathogenesis of the infection, the mechanisms underlying innate and, critically, adaptive immune responses to encapsulated bacteria have not been fully elucidated. As such, we became interested in studying the CPS of two similar, but unique, streptococcal species: Group B Streptococcus (GBS) and Streptococcus suis . Both streptococci are well encapsulated, some capsular types are more virulent than others, and they can cause severe meningitis and septicemia. For both pathogens, the CPS is considered the major virulence factor. Finally, these two streptococci are the sole Gram-positive bacteria possessing sialic acid in their capsules. GBS type III is a leading cause of neonatal invasive infections. Streptococcus suis type 2 is an important swine and emerging zoonotic pathogen in humans. We recently characterized the S. suis type 2 CPS. It shares common structural elements with GBS, but sialic acid is α2,6-linked to galactose rather than α2,3-linked. Differential sialic acid expression by pathogens might result in modulation of immune cell activation and, consequently, may affect the immuno-pathogenesis of these bacterial infections. Here, we review and compare the interactions of these two sialylated encapsulated bacteria with dendritic cells, known as the most potent antigen-presenting cells linking innate and adaptive immunity. We further address differences between dendritic cells and professional phagocytes, such as macrophages and neutrophils, in their interplay with these encapsulated pathogens. Elucidation of the molecular and cellular basis of the impact of CPS composition on bacterial interactions with immune cells is critical for mechanistic

  6. Characterization of the pivotal carbon metabolism of Streptococcus suis serotype 2 under ex vivo and chemically defined in vitro conditions by isotopologue profiling.

    PubMed

    Willenborg, Jörg; Huber, Claudia; Koczula, Anna; Lange, Birgit; Eisenreich, Wolfgang; Valentin-Weigand, Peter; Goethe, Ralph

    2015-02-27

    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. PMID:25575595

  7. Characterization of the Pivotal Carbon Metabolism of Streptococcus suis Serotype 2 under ex Vivo and Chemically Defined in Vitro Conditions by Isotopologue Profiling*

    PubMed Central

    Willenborg, Jörg; Huber, Claudia; Koczula, Anna; Lange, Birgit; Eisenreich, Wolfgang; Valentin-Weigand, Peter; Goethe, Ralph

    2015-01-01

    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

  8. Virulence genotyping and population analysis of Streptococcus suis serotype 2 isolates from China.

    PubMed

    Dong, Wenyang; Ma, Jiale; Zhu, Yinchu; Zhu, Jielian; Yuan, Lvfeng; Wang, Yanan; Xu, Jueqiong; Pan, Zihao; Wu, Zongfu; Zhang, Wei; Lu, Chengping; Yao, Huochun

    2015-12-01

    Streptococcus suis is one of the most important swine pathogens worldwide. In this study, a total of 22 virulence-related genes in 101 strains of S. suis serotype 2 (SS2) were detected by PCR, namely, mrp, epf, sly, fbps, rgg, ofs, srtA, pgdA, gapdh, iga, endoD, ciaRH, salKR, manN, purD, rgg, DppIV, neuB, dltA, SMU_61-like, SpyM3_0908 (Permease) and the SspA gene. The distribution of virulence-related genes among isolates was visualized using BioNumerics software to study similarities among the isolates. Two clusters of SS2 were apparent on the phylogenetic tree, namely, Clusters A and B. Both mouse and zebrafish infection models revealed that strains in Cluster B were more virulent than those in Cluster A. Statistical comparison between the two clusters was performed, and structure analysis demonstrated that epf, sly, rgg, endoD, SMU_61-like and SpyM3_0908 were possible predictive markers for SS2 virulence. The transcription levels of highly prevalent genes in both clusters were detected by qRT-PCR in representative strains. For Cluster A isolates, the transcription levels of neuB, dltA, fbps and pgdA were significantly lower, but the transcription level of iga was significantly higher than that in Cluster B isolates. Although encoded in the genomes of the selected Cluster A isolates, DppIV and mrp genes were not expressed. These results revealed the genetic differences between virulent and low-virulence SS2 isolates from China and provide a better understanding of the SS2 pathogenic mechanism. PMID:26303637

  9. Clearance of Streptococcus suis in Stomach Contents of Differently Fed Growing Pigs.

    PubMed

    Warneboldt, Franziska; Sander, Saara J; Beineke, Andreas; Valentin-Weigand, Peter; Kamphues, Josef; Baums, Christoph Georg

    2016-01-01

    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. PMID:27509526

  10. Comparative Genome Analyses of Streptococcus suis Isolates from Endocarditis Demonstrate Persistence of Dual Phenotypic Clones

    PubMed Central

    Tohya, Mari; Watanabe, Takayasu; Maruyama, Fumito; Arai, Sakura; Ota, Atsushi; Athey, Taryn B. T.; Fittipaldi, Nahuel; Nakagawa, Ichiro; Sekizaki, Tsutomu

    2016-01-01

    Many bacterial species coexist in the same niche as heterogeneous clones with different phenotypes; however, understanding of infectious diseases by polyphenotypic bacteria is still limited. In the present study, encapsulation in isolates of the porcine pathogen Streptococcus suis from persistent endocarditis lesions was examined. Coexistence of both encapsulated and unencapsulated S. suis isolates was found in 26 out of 59 endocarditis samples. The isolates were serotype 2, and belonged to two different sequence types (STs), ST1 and ST28. The genomes of each of the 26 pairs of encapsulated and unencapsulated isolates from the 26 samples were sequenced. The data showed that each pair of isolates had one or more unique nonsynonymous mutations in the cps gene, and the encapsulated and unencapsulated isolates from the same samples were closest to each other. Pairwise comparisons of the sequences of cps genes in 7 pairs of encapsulated and unencapsulated isolates identified insertion/deletions (indels) ranging from one to 104 bp in different cps genes of unencapsulated isolates. Capsule expression was restored in a subset of unencapsulated isolates by complementation in trans with cps expression vectors. Examination of gene content common to isolates indicated that mutation frequency was higher in ST28 pairs than in ST1 pairs. Genes within mobile genetic elements were mutation hot spots among ST28 isolates. Taken all together, our results demonstrate the coexistence of dual phenotype (encapsulated and unencapsulated) bacterial clones and suggest that the dual phenotypes arose independently in each farm by means of spontaneous mutations in cps genes. PMID:27433935

  11. The Streptococcus suis transcriptional landscape reveals adaptation mechanisms in pig blood and cerebrospinal fluid

    PubMed Central

    Wu, Zongfu; Wu, Chunyan; Shao, Jing; Zhu, Zhenzhen; Wang, Weixue; Zhang, Wenwei; Tang, Min; Pei, Na; Fan, Hongjie; Li, Jiguang; Yao, Huochun; Gu, Hongwei; Xu, Xun; Lu, Chengping

    2014-01-01

    Streptococcus suis (SS) is an important pathogen of pigs, and it is also recognized as a zoonotic agent for humans. SS infection may result in septicemia or meningitis in the host. However, little is known about genes that contribute to the virulence process and survival within host blood or cerebrospinal fluid (CSF). Small RNAs (sRNA) have emerged as key regulators of virulence in several bacteria, but they have not been investigated in SS. Here, using a differential RNA-sequencing approach and RNAs from SS strain P1/7 grown in rich medium, pig blood, or CSF, we present the SS genome-wide map of 793 transcriptional start sites and 370 operons. In addition to identifying 29 sRNAs, we show that five sRNA deletion mutants attenuate SS virulence in a zebrafish infection model. Homology searches revealed that 10 sRNAs were predicted to be present in other pathogenic Streptococcus species. Compared with wild-type strain P1/7, sRNAs rss03, rss05, and rss06 deletion mutants were significantly more sensitive to killing by pig blood. It is possible that rss06 contributes to SS virulence by indirectly activating expression of SSU0308, a virulence gene encoding a zinc-binding lipoprotein. In blood, genes involved in the synthesis of capsular polysaccharide (CPS) and subversion of host defenses were up-regulated. In contrast, in CSF, genes for CPS synthesis were down-regulated. Our study is the first analysis of SS sRNAs involved in virulence and has both improved our understanding of SS pathogenesis and increased the number of sRNAs known to play definitive roles in bacterial virulence. PMID:24759092

  12. Transcriptional Analysis of PRRSV-Infected Porcine Dendritic Cell Response to Streptococcus suis Infection Reveals Up-Regulation of Inflammatory-Related Genes Expression

    PubMed Central

    Auray, Gaël; Lachance, Claude; Wang, Yingchao; Gagnon, Carl A.; Segura, Mariela; Gottschalk, Marcelo

    2016-01-01

    The porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most important swine pathogens and often serves as an entry door for other viral or bacterial pathogens, of which Streptococcus suis is one of the most common. Pre-infection with PRRSV leads to exacerbated disease caused by S. suis infection. Very few studies have assessed the immunological mechanisms underlying this higher susceptibility. Since antigen presenting cells play a major role in the initiation of the immune response, the in vitro transcriptional response of bone marrow-derived dendritic cells (BMDCs) and monocytes in the context of PRRSV and S. suis co-infection was investigated. BMDCs were found to be more permissive than monocytes to PRRSV infection; S. suis phagocytosis by PRRSV-infected BMDCs was found to be impaired, whereas no effect was found on bacterial intracellular survival. Transcription profile analysis, with a major focus on inflammatory genes, following S. suis infection, with and without pre-infection with PRRSV, was then performed. While PRRSV pre-infection had little effect on monocytes response to S. suis infection, a significant expression of several pro-inflammatory molecules was observed in BMDCs pre-infected with PRRSV after a subsequent infection with S. suis. While an additive effect could be observed for CCL4, CCL14, CCL20, and IL-15, a distinct synergistic up-regulatory effect was observed for IL-6, CCL5 and TNF-α after co-infection. This increased pro-inflammatory response by DCs could participate in the exacerbation of the disease observed during PRRSV and S. suis co-infection. PMID:27213692

  13. Mutations in the Gene Encoding the Ancillary Pilin Subunit of the Streptococcus suis srtF Cluster Result in Pili Formed by the Major Subunit Only

    PubMed Central

    Fittipaldi, Nahuel; Takamatsu, Daisuke; la Cruz Domínguez-Punaro, María de; Lecours, Marie-Pier; Montpetit, Diane; Osaki, Makoto; Sekizaki, Tsutomu; Gottschalk, Marcelo

    2010-01-01

    Pili have been shown to contribute to the virulence of different Gram-positive pathogenic species. Among other critical steps of bacterial pathogenesis, these structures participate in adherence to host cells, colonization and systemic virulence. Recently, the presence of at least four discrete gene clusters encoding putative pili has been revealed in the major swine pathogen and emerging zoonotic agent Streptococcus suis. However, pili production by this species has not yet been demonstrated. In this study, we investigated the functionality of one of these pili clusters, known as the srtF pilus cluster, by the construction of mutant strains for each of the four genes of the cluster as well as by the generation of antibodies against the putative pilin subunits. Results revealed that the S. suis serotype 2 strain P1/7, as well as several other highly virulent invasive S. suis serotype 2 isolates express pili from this cluster. However, in most cases tested, and as a result of nonsense mutations at the 5′ end of the gene encoding the minor pilin subunit (a putative adhesin), pili were formed by the major pilin subunit only. We then evaluated the role these pili play in S. suis virulence. Abolishment of the expression of srtF cluster-encoded pili did not result in impaired interactions of S. suis with porcine brain microvascular endothelial cells. Furthermore, non-piliated mutants were as virulent as the wild type strain when evaluated in a murine model of S. suis sepsis. Our results show that srtF cluster-encoded, S. suis pili are atypical compared to other Gram-positive pili. In addition, since the highly virulent strains under investigation are unlikely to produce other pili, our results suggest that pili might be dispensable for critical steps of the S. suis pathogenesis of infection. PMID:20052283

  14. Assessment of MALDI-TOF MS as Alternative Tool for Streptococcus suis Identification.

    PubMed

    Pérez-Sancho, Marta; Vela, Ana Isabel; García-Seco, Teresa; Gottschalk, Marcelo; Domínguez, Lucas; Fernández-Garayzábal, José Francisco

    2015-01-01

    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

  15. A Zebrafish Larval Model to Assess Virulence of Porcine Streptococcus suis Strains.

    PubMed

    Zaccaria, Edoardo; Cao, Rui; Wells, Jerry M; van Baarlen, Peter

    2016-01-01

    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

  16. Interaction of fibrinogen and muramidase-released protein promotes the development of Streptococcus suis meningitis.

    PubMed

    Wang, Junping; Kong, Decong; Zhang, Shengwei; Jiang, Hua; Zheng, Yuling; Zang, Yating; Hao, Huaijie; Jiang, Yongqiang

    2015-01-01

    Muramidase-released protein (MRP) is as an important virulence marker of Streptococcus suis (S. suis) serotype 2. Our previous works have shown that MRP can bind human fibrinogen (hFg); however, the function of this interaction in S. suis meningitis is not known. In this study, we found that the deletion of mrp significantly impairs the hFg-mediated adherence and traversal ability of S. suis across human cerebral microvascular endothelial cells (hCMEC/D3). Measurement of the permeability to Lucifer yellow in vitro and Evans blue extravasation in vivo show that the MRP-hFg interaction significantly increases the permeability of the blood-brain barrier (BBB). In the mouse meningitis model, wild type S. suis caused higher bacterial loads in the brain and more severe histopathological signs of meningitis than the mrp mutant at day 3 post-infection. Western blot analysis and immunofluorescence observations reveal that the MRP-hFg interaction can destroy the cell adherens junction protein p120-catenin of hCMEC/D3. These results indicate that the MRP-hFg interaction is important in the development of S. suis meningitis. PMID:26441928

  17. Lgt Processing Is an Essential Step in Streptococcus suis Lipoprotein Mediated Innate Immune Activation

    PubMed Central

    Wichgers Schreur, Paul J.; Rebel, Johanna M. J.; Smits, Mari A.; van Putten, Jos P. M.; Smith, Hilde E.

    2011-01-01

    Background Streptococcus suis causes invasive infections in pigs and occasionally in humans. The host innate immune system plays a major role in counteracting S. suis infections. The main components of S. suis able to activate the innate immune system likely include cell wall constituents that may be released during growth or after cell wall integrity loss, however characterization of these components is still limited. Methology/Principal Findings A concentrated very potent innate immunity activating supernatant of penicillin-treated S. suis was SDS-PAGE fractionated and tested for porcine peripheral blood mononucleated cell (PBMC) stimulating activity using cytokine gene transcript analysis. More than half of the 24 tested fractions increased IL-1β and IL-8 cytokine gene transcript levels in porcine PBMCs. Mass spectrometry of the active fractions indicated 24 proteins including 9 lipoproteins. Genetic inactivation of a putative prolipoprotein diacylglyceryl transferase (Lgt) gene resulted in deficient lipoprotein synthesis as evidenced by palmitate labeling. The Lgt mutant showed strongly reduced activation of porcine PBMCs, indicating that lipoproteins are dominant porcine PBMC activating molecules of S. suis. Conclusion/Significance This study for the first time identifies and characterizes lipoproteins of S. suis as major activators of the innate immune system of the pig. In addition, we provide evidence that Lgt processing of lipoproteins is required for lipoprotein mediated innate immune activation. PMID:21811583

  18. A Zebrafish Larval Model to Assess Virulence of Porcine Streptococcus suis Strains

    PubMed Central

    Zaccaria, Edoardo; Cao, Rui; Wells, Jerry M.; van Baarlen, Peter

    2016-01-01

    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

  19. Assessment of MALDI-TOF MS as Alternative Tool for Streptococcus suis Identification

    PubMed Central

    Pérez-Sancho, Marta; Vela, Ana Isabel; García-Seco, Teresa; Gottschalk, Marcelo; Domínguez, Lucas; Fernández-Garayzábal, José Francisco

    2015-01-01

    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

  20. Streptococcus suis in employees and the environment of swine slaughterhouses in São Paulo, Brazil: Occurrence, risk factors, serotype distribution, and antimicrobial susceptibility

    PubMed Central

    Soares, Taíssa Cook Siqueira; Gottschalk, Marcelo; Lacouture, Sonia; Megid, Jane; Ribolla, Paulo Eduardo Martins; de Figueiredo Pantoja, José Carlos; Paes, Antonio Carlos

    2015-01-01

    Streptococcus suis is an important pathogen in the swine industry. This article is the first to report the occurrence, risk factors, serotype distribution, and antimicrobial susceptibility of S. suis recovered from employees and environmental samples of swine slaughterhouses in Brazil. Tonsillar swabs from all 139 pig-slaughtering employees and 261 environmental swabs were collected for detection of S. suis and serotyping by monoplex and multiplex polymerase chain reaction, respectively. Antimicrobial susceptibility was determined by the disk-diffusion method. Although S. suis was not detected in any of the tested employees, it was isolated from 25% of the environmental samples. Significant differences (P < 0.05) in the occurrence of S. suis were observed between slaughterhouses and between areas of low, medium, and high risk. The most frequent serotypes were 4 and 29, each accounting for 12% of the isolates, followed by 5, 12, 21, and 31, each accounting for 6%. High rates of susceptibility to the antimicrobials doxycycline (100%), ceftiofur (94%), ampicillin (81%), and cephalexin (75%) were observed. However, multidrug resistance was observed in all the isolates. Because S. suis is present in the environment of swine slaughterhouses, on carcasses and knives, as well as on the hands of employees in all areas, all employees are at risk of infection. PMID:26424907

  1. Binding of Human Fibrinogen to MRP Enhances Streptococcus suis Survival in Host Blood in a αXβ2 Integrin-dependent Manner.

    PubMed

    Pian, Yaya; Li, Xueqin; Zheng, Yuling; Wu, Xiaohong; Yuan, Yuan; Jiang, Yongqiang

    2016-01-01

    The Gram-positive bacterium Streptococcus suis serotype 2 (S. suis 2), an important zoonotic pathogen, induces strong systemic infections in humans; sepsis and meningitis are the most common clinical manifestations and are often accompanied by bacteremia. However, the mechanisms of S. suis 2 survival in human blood are not well understood. In our previous study, we identified muramidase-released protein (MRP), a novel human fibrinogen (hFg)-binding protein (FBP) in S. suis 2 that is an important epidemic infection marker with an unknown mechanism in pathogenesis. The present study demonstrates that the N-terminus of MRP (a.a. 283-721) binds to both the Aα and Bβ chains of the D fragment of hFg. Strikingly, the hFg-MRP interaction improved the survival of S. suis 2 in human blood and led to the aggregation and exhaustion of polymorphonuclear neutrophils (PMNs) via an αXβ2 integrin-dependent mechanism. Other Fg-binding proteins, such as M1 (GAS) and FOG (GGS), also induced PMNs aggregation; however, the mechanisms of these FBP-hFg complexes in the evasion of PMN-mediated innate immunity remain unclear. MRP is conserved across highly virulent strains in Europe and Asia, and these data shed new light on the function of MRP in S. suis pathogenesis. PMID:27231021

  2. Binding of Human Fibrinogen to MRP Enhances Streptococcus suis Survival in Host Blood in a αXβ2 Integrin-dependent Manner

    PubMed Central

    Pian, Yaya; Li, Xueqin; Zheng, Yuling; Wu, Xiaohong; Yuan, Yuan; Jiang, Yongqiang

    2016-01-01

    The Gram-positive bacterium Streptococcus suis serotype 2 (S. suis 2), an important zoonotic pathogen, induces strong systemic infections in humans; sepsis and meningitis are the most common clinical manifestations and are often accompanied by bacteremia. However, the mechanisms of S. suis 2 survival in human blood are not well understood. In our previous study, we identified muramidase-released protein (MRP), a novel human fibrinogen (hFg)-binding protein (FBP) in S. suis 2 that is an important epidemic infection marker with an unknown mechanism in pathogenesis. The present study demonstrates that the N-terminus of MRP (a.a. 283–721) binds to both the Aα and Bβ chains of the D fragment of hFg. Strikingly, the hFg-MRP interaction improved the survival of S. suis 2 in human blood and led to the aggregation and exhaustion of polymorphonuclear neutrophils (PMNs) via an αXβ2 integrin-dependent mechanism. Other Fg-binding proteins, such as M1 (GAS) and FOG (GGS), also induced PMNs aggregation; however, the mechanisms of these FBP-hFg complexes in the evasion of PMN-mediated innate immunity remain unclear. MRP is conserved across highly virulent strains in Europe and Asia, and these data shed new light on the function of MRP in S. suis pathogenesis. PMID:27231021

  3. Streptococcus suis in employees and the environment of swine slaughterhouses in São Paulo, Brazil: Occurrence, risk factors, serotype distribution, and antimicrobial susceptibility.

    PubMed

    Soares, Taíssa Cook Siqueira; Gottschalk, Marcelo; Lacouture, Sonia; Megid, Jane; Ribolla, Paulo Eduardo Martins; Pantoja, José Carlos de Figueiredo; Paes, Antonio Carlos

    2015-10-01

    Streptococcus suis is an important pathogen in the swine industry. This article is the first to report the occurrence, risk factors, serotype distribution, and antimicrobial susceptibility of S. suis recovered from employees and environmental samples of swine slaughterhouses in Brazil. Tonsillar swabs from all 139 pig-slaughtering employees and 261 environmental swabs were collected for detection of S. suis and serotyping by monoplex and multiplex polymerase chain reaction, respectively. Antimicrobial susceptibility was determined by the disk-diffusion method. Although S. suis was not detected in any of the tested employees, it was isolated from 25% of the environmental samples. Significant differences (P < 0.05) in the occurrence of S. suis were observed between slaughterhouses and between areas of low, medium, and high risk. The most frequent serotypes were 4 and 29, each accounting for 12% of the isolates, followed by 5, 12, 21, and 31, each accounting for 6%. High rates of susceptibility to the antimicrobials doxycycline (100%), ceftiofur (94%), ampicillin (81%), and cephalexin (75%) were observed. However, multidrug resistance was observed in all the isolates. Because S. suis is present in the environment of swine slaughterhouses, on carcasses and knives, as well as on the hands of employees in all areas, all employees are at risk of infection. PMID:26424907

  4. Complex Population Structure and Virulence Differences among Serotype 2 Streptococcus suis Strains Belonging to Sequence Type 28

    PubMed Central

    Athey, Taryn B. T.; Auger, Jean-Philippe; Teatero, Sarah; Dumesnil, Audrey; Takamatsu, Daisuke; Wasserscheid, Jessica; Dewar, Ken; Gottschalk, Marcelo; Fittipaldi, Nahuel

    2015-01-01

    Streptococcus suis is a major swine pathogen and a zoonotic agent. Serotype 2 strains are the most frequently associated with disease. However, not all serotype 2 lineages are considered virulent. Indeed, sequence type (ST) 28 serotype 2 S. suis strains have been described as a homogeneous group of low virulence. However, ST28 strains are often isolated from diseased swine in some countries, and at least four human ST28 cases have been reported. Here, we used whole-genome sequencing and animal infection models to test the hypothesis that the ST28 lineage comprises strains of different genetic backgrounds and different virulence. We used 50 S. suis ST28 strains isolated in Canada, the United States and Japan from diseased pigs, and one ST28 strain from a human case isolated in Thailand. We report a complex population structure among the 51 ST28 strains. Diversity resulted from variable gene content, recombination events and numerous genome-wide polymorphisms not attributable to recombination. Phylogenetic analysis using core genome single-nucleotide polymorphisms revealed four discrete clades with strong geographic structure, and a fifth clade formed by US, Thai and Japanese strains. When tested in experimental animal models, strains from this latter clade were significantly more virulent than a Canadian ST28 reference strain, and a closely related Canadian strain. Our results highlight the limitations of MLST for both phylogenetic analysis and virulence prediction and raise concerns about the possible emergence of ST28 strains in human clinical cases. PMID:26375680

  5. Population analysis of Streptococcus suis isolates from slaughtered swine by use of minimum core genome sequence typing.

    PubMed

    Zheng, Han; Ji, Shaobo; Lan, Ruiting; Liu, Zhijie; Bai, Xuemei; Zhang, Wen; Gottschalk, Marcelo; Xu, Jianguo

    2014-10-01

    Streptococcus suis, an important zoonotic pathogen, is a highly diverse species with only a subset of strains that cause disease in humans. Our previous study proposed a minimum core genome (MCG) sequence typing method and defined seven MCG groups, with MCG group 1 as the prevalent group causing human infections. In this study, we identified a set of 10 single nucleotide polymorphisms (SNPs) distributed in six genes that were used to identify the seven MCG groups. The 10 SNPs were typed for 179 S. suis isolates collected from slaughtered pigs. The most prevalent groups among the tested isolates were MCG groups 6 and 7. Most of the isolates (147/179) were genotyped as mrp negative, epf negative, sly negative, and CDS2157 positive. The 179 isolates were also typed by multilocus sequence typing (MLST) and divided into 115 sequence types (STs), 111 of which were new. The 6 serotypes (29, 11, 5, 12, 30, and 2) represented 72.3% of the serotyped isolates. Our data show that the typing assay facilitates the application of genome data to the surveillance of S. suis. PMID:25056323

  6. Bacterial Adhesion of Streptococcus suis to Host Cells and Its Inhibition by Carbohydrate Ligands

    PubMed Central

    Kouki, Annika; Pieters, Roland J.; Nilsson, Ulf J.; Loimaranta, Vuokko; Finne, Jukka; Haataja, Sauli

    2013-01-01

    Streptococcus suis is a Gram-positive bacterium, which causes sepsis and meningitis in pigs and humans. This review examines the role of known S. suis virulence factors in adhesion and S. suis carbohydrate-based adhesion mechanisms, as well as the inhibition of S. suis adhesion by anti-adhesion compounds in in vitro assays. Carbohydrate-binding specificities of S. suis have been identified, and these studies have shown that many strains recognize Galα1-4Gal-containing oligosaccharides present in host glycolipids. In the era of increasing antibiotic resistance, new means to treat infections are needed. Since microbial adhesion to carbohydrates is important to establish disease, compounds blocking adhesion could be an alternative to antibiotics. The use of oligosaccharides as drugs is generally hampered by their relatively low affinity (micromolar) to compete with multivalent binding to host receptors. However, screening of a library of chemically modified Galα1-4Gal derivatives has identified compounds that inhibit S. suis adhesion in nanomolar range. Also, design of multivalent Galα1-4Gal-containing dendrimers has resulted in a significant increase of the inhibitory potency of the disaccharide. The S. suis adhesin binding to Galα1-4Gal-oligosaccharides, Streptococcal adhesin P (SadP), was recently identified. It has a Galα1-4Gal-binding N-terminal domain and a C-terminal LPNTG-motif for cell wall anchoring. The carbohydrate-binding domain has no homology to E. coli P fimbrial adhesin, which suggests that these Gram-positive and Gram-negative bacterial adhesins recognizing the same receptor have evolved by convergent evolution. SadP adhesin may represent a promising target for the design of anti-adhesion ligands for the prevention and treatment of S. suis infections. PMID:24833053

  7. Role of the capsular polysaccharide as a virulence factor for Streptococcus suis serotype 14

    PubMed Central

    Roy, David; Auger, Jean-Philippe; Segura, Mariela; Fittipaldi, Nahuel; Takamatsu, Daisuke; Okura, Masatoshi; Gottschalk, Marcelo

    2015-01-01

    Streptococcus suis is an important swine pathogen and a zoonotic agent causing meningitis and septicemia. Although serotype 2 is the most virulent type, serotype 14 is emerging, and understanding of its pathogenesis is limited. To study the role of the capsular polysaccharide (CPS) of serotype 14 as a virulence factor, we constructed knockout mutants devoid of either cps14B, a highly conserved regulatory gene, or neu14C, a gene coding for uridine diphospho-N-acetylglucosamine 2-epimerase, which is involved in sialic acid synthesis. The mutants showed total loss of the CPS with coagglutination assays and electron microscopy. Phagocytosis assays showed high susceptibility of mutant Δcps14B. An in vivo murine model was used to demonstrate attenuated virulence of this non-encapsulated mutant. Despite the difference in the CPS composition of different serotypes, this study has demonstrated for the first time that the CPS of a serotype other than 2 is also an important antiphagocytic factor and a critical virulence factor. PMID:25852230

  8. Capsular Sialic Acid of Streptococcus suis Serotype 2 Binds to Swine Influenza Virus and Enhances Bacterial Interactions with Virus-Infected Tracheal Epithelial Cells

    PubMed Central

    Wang, Yingchao; Gagnon, Carl A.; Savard, Christian; Music, Nedzad; Srednik, Mariela; Segura, Mariela; Lachance, Claude; Bellehumeur, Christian

    2013-01-01

    Streptococcus suis serotype 2 is an important swine bacterial pathogen, and it is also an emerging zoonotic agent. It is unknown how S. suis virulent strains, which are usually found in low quantities in pig tonsils, manage to cross the first host defense lines to initiate systemic disease. Influenza virus produces a contagious infection in pigs which is frequently complicated by bacterial coinfections, leading to significant economic impacts. In this study, the effect of a preceding swine influenza H1N1 virus (swH1N1) infection of swine tracheal epithelial cells (NTPr) on the ability of S. suis serotype 2 to adhere to, invade, and activate these cells was evaluated. Cells preinfected with swH1N1 showed bacterial adhesion and invasion levels that were increased more than 100-fold compared to those of normal cells. Inhibition studies confirmed that the capsular sialic acid moiety is responsible for the binding to virus-infected cell surfaces. Also, preincubation of S. suis with swH1N1 significantly increased bacterial adhesion to/invasion of epithelial cells, suggesting that S. suis also uses swH1N1 as a vehicle to invade epithelial cells when the two infections occur simultaneously. Influenza virus infection may facilitate the transient passage of S. suis at the respiratory tract to reach the bloodstream and cause bacteremia and septicemia. S. suis may also increase the local inflammation at the respiratory tract during influenza infection, as suggested by an exacerbated expression of proinflammatory mediators in coinfected cells. These results give new insight into the complex interactions between influenza virus and S. suis in a coinfection model. PMID:24082069

  9. Antimicrobial Activity of Penicillin G and N-acetylcystein on Planktonic and Sessile Cells of Streptococcus suis.

    PubMed

    Espinosa, Ivette; Báez, Michel; Lobo, Evelyn; Martínez, Siomara; Gottschalk, Marcelo

    2016-01-01

    The aim of this study was to investigate the capacity of Streptococcus suis strains to form biofilms and to evaluate the antimicrobial activity of Penicillin G and N-acetylcystein (NAC) on both S. suis sessile and planktonic forms. Only non-typeable isolates of S. suis were correlated with a greater biofilm formation capacity. The MCI of Penicillin G and NAC required for inhibiting biofilm growth were higher than the required concentration for inhibiting planktonic growth. The combinations of NAC and Penicillin G showed a strong synergistic activity that inhibited biofilm formation and disrupted the pre-formed biofilm of S. suis. PMID:27282001

  10. Streptococcus suis toxic-shock syndrome and meningitis.

    PubMed

    Leelarasamee, A; Nilakul, C; Tien-Grim, S; Srifuengfung, S; Susaengrat, W

    1997-01-01

    Three cases with S. suis bacteremia and meningitis were reported. The first case was a 23-year-old butcher who was a regular drinker of alcohol for two years and developed streptococcal toxic-shock syndrome. The organism was transmitted to him through a minor cut in his right arm. The second cases was a 49-year-old female laborer who had been consuming locally produced alcohol for 20 years and developed fever and meningitis. Unfortunately, she succumbed in seven days despite intensive supportive and cefotaxime treatments. The third case was a 45-year-old regular alcoholic drinker and car painter who was seen at a private hospital due to contusion at his left lateral chest wall. However, fever and confusion due to meningitis was detected upon admission. Irreversible deafness developed within 48 hours of ceftriaxone therapy for meningitis. He finally recovered with deafness. S. suis was isolated from blood and cerebrospinal fluid cultures in all three cases though initially reported to be viridans group of streptococci. PMID:9078819

  11. Streptococcus anginosus ("Streptococcus milleri"): the unrecognized pathogen.

    PubMed Central

    Ruoff, K L

    1988-01-01

    "Streptococcus milleri" is an unofficial name that has been applied to a group of streptococci which, although basically similar, show various hemolytic, serological, and physiological characteristics. The species name Streptococcus anginosus has recently been recognized as the approved name for these organisms. Streptococci known as "S. milleri" have been implicated as etiologic agents in a variety of serious purulent infections, but because of their heterogeneous characteristics, these organisms may be unrecognized or misidentified by clinical laboratorians. This review describes the bacteriological aspects of organisms known as "S. milleri," their clinical significance, and the problems encountered with their identification in the clinical laboratory. PMID:3060239

  12. Metabolic Context of the Competence-Induced Checkpoint for Cell Replication in Streptococcus suis

    PubMed Central

    Zaccaria, Edoardo; Wells, Jerry M.

    2016-01-01

    Natural genetic transformation is a transient, rapidly progressing energy-consuming process characterized by expression of the transformasome and competence-associated regulatory genes. This transient state is tightly controlled to avoid potentially adverse effects of genetic recombination on genome integrity during cell division. We investigated the global response of Streptococcus suis to exposure to the SigX competence-inducing peptide (XIP), and thus to the activation of the competence machinery, using time series analysis together with PCA analysis, gene clustering followed by heatmap visualisation, and GO enrichment analysis. We explored the possible regulatory link between metabolism and competence, and predicted the physiological adaptation of S. suis during competence induction, progression and exit using transcriptome analysis. We showed that competence development is associated with a suppression of basal metabolism, which may have consequences for the microbe's resilience to fluctuations in the environment, as competence is costly in terms of use of energy and protein translation. Furthermore our data suggest that several basal metabolic pathways are incompatible with activation of competence in S. suis. This study also showed that targeting specific pathways during the development of competence, might render S. suis more vulnerable toward novel antibiotic therapies. PMID:27149631

  13. Risk Factors of Streptococcus suis Infection in Vietnam. A Case-Control Study

    PubMed Central

    Ho, Dang Trung Nghia; Le, Thi Phuong Tu; Wolbers, Marcel; Cao, Quang Thai; Nguyen, Van Minh Hoang; Tran, Vu Thieu Nga; Le, Thi Phuong Thao; Nguyen, Hoan Phu; Tran, Thi Hong Chau; Dinh, Xuan Sinh; To, Song Diep; Hoang, Thi Thanh Hang; Hoang, Truong; Campbell, James; Nguyen, Van Vinh Chau; Nguyen, Tran Chinh; Nguyen, Van Dung; Ngo, Thi Hoa; Spratt, Brian G.; Tran, Tinh Hien; Farrar, Jeremy; Schultsz, Constance

    2011-01-01

    Background Streptococcus suis infection, an emerging zoonosis, is an increasing public health problem across South East Asia and the most common cause of acute bacterial meningitis in adults in Vietnam. Little is known of the risk factors underlying the disease. Methods and Findings A case-control study with appropriate hospital and matched community controls for each patient was conducted between May 2006 and June 2009. Potential risk factors were assessed using a standardized questionnaire and investigation of throat and rectal S. suis carriage in cases, controls and their pigs, using real-time PCR and culture of swab samples. We recruited 101 cases of S. suis meningitis, 303 hospital controls and 300 community controls. By multivariate analysis, risk factors identified for S. suis infection as compared to either control group included eating “high risk” dishes, including such dishes as undercooked pig blood and pig intestine (OR1 = 2.22; 95%CI = [1.15–4.28] and OR2 = 4.44; 95%CI = [2.15–9.15]), occupations related to pigs (OR1 = 3.84; 95%CI = [1.32–11.11] and OR2 = 5.52; 95%CI = [1.49–20.39]), and exposures to pigs or pork in the presence of skin injuries (OR1 = 7.48; 95%CI = [1.97–28.44] and OR2 = 15.96; 95%CI = [2.97–85.72]). S. suis specific DNA was detected in rectal and throat swabs of 6 patients and was cultured from 2 rectal samples, but was not detected in such samples of 1522 healthy individuals or patients without S. suis infection. Conclusions This case control study, the largest prospective epidemiological assessment of this disease, has identified the most important risk factors associated with S. suis bacterial meningitis to be eating ‘high risk’ dishes popular in parts of Asia, occupational exposure to pigs and pig products, and preparation of pork in the presence of skin lesions. These risk factors can be addressed in public health campaigns aimed at preventing S. suis infection

  14. A Streptococcus suis LysM domain surface protein contributes to bacterial virulence.

    PubMed

    Wu, Zongfu; Shao, Jing; Ren, Haiyan; Tang, Huanyu; Zhou, Mingyao; Dai, Jiao; Lai, Liying; Yao, Huochun; Fan, Hongjie; Chen, Dai; Zong, Jie; Lu, Chengping

    2016-05-01

    Streptococcus suis (SS) is a major swine pathogen, as well as a zoonotic agent for humans. Numerous factors contribute to SS virulence, but the pathogenesis of SS infection is poorly understood. Here, we show that a novel SS surface protein containing a LysM at the N-terminus (SS9-LysM) contributes to SS virulence. Homology analysis revealed that the amino acid sequence of SS9-LysM from the SS strain GZ0565 shares 99.8-68.7% identity with homologous proteins from other SS strains and 41.2% identity with Group B Streptococcal protective antigen Sip. Immunization experiments showed that 7 out of 30 mice immunized with recombinant SS9-LysM were protected against challenge with the virulent GZ0565 strain, while all of the control mice died within 48h following bacterial challenge. In mouse infection model, the virulence of the SS9-LysM deletion mutant (ΔSS9-LysM) was reduced compared with the wild-type (WT) strain GZ0565 and SS9-LysM complemented strain. In addition, ΔSS9-LysM was significantly more sensitive to killing by pig blood ex vivo and mouse blood in vivo compared with the WT strain and SS9-LysM complemented strain. In vivo transcriptome analysis in mouse blood showed that the WT strain reduced the expression of host genes related to iron-binding by SS9-LysM. Moreover, the total free iron concentration in blood from infected mice was significantly lower for the ΔSS9-LysM strain compared with the WT strain. Together, our data reveal that SS9-LysM facilitates SS survival within blood by releasing more free iron from the host. This represents a new mechanism of SS pathogenesis. PMID:27066710

  15. Clonal distribution of Streptococcus suis isolated from diseased pigs in the central region of Chile

    PubMed Central

    Morales, Bárbara; Ruiz, Álvaro; Lacouture, Sonia; Gottschalk, Marcelo

    2015-01-01

    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

  16. Development of a multiplex PCR assay to detect the major clonal complexes of Streptococcus suis relevant to human infection.

    PubMed

    Hatrongjit, Rujirat; Kerdsin, Anusak; Gottschalk, Marcelo; Hamada, Shigeyuki; Oishi, Kazunori; Akeda, Yukihiro

    2016-05-01

    Multilocus sequence typing (MLST) is considered a reliable method for providing insight into the Streptococcus suis population structure, clonal relationships and the potential of particular clones to cause disease. Indeed, MLST has revealed the presence of several clonal complexes (CCs) within the Streptococcus suis population. However, the method is costly, time-consuming and difficult to use for screening large numbers of isolates. In this study, a multiplex PCR assay was developed to identify Streptococcus suis CCs that are relevant to human infections. The multiplex PCR assay was capable of simultaneously distinguishing CC1, CC25, CC28, CC104, CC221/234 and CC233/379, which are related to human infections in Thailand, in a single reaction. The multiplex PCR assay is useful for low-cost screening of large numbers of isolates with rapid analytical capacity and could be utilized in most laboratories. PMID:26932590

  17. Stimulating the development of national Streptococcus suis guidelines in Viet Nam through a strategic research partnership

    PubMed Central

    Wertheim, Heiman; Ha, Nguyen Hong; Trung, Nguyen Vu; Trinh, Dao Tuyet; Taylor, Walter; Ha, Nguyen Minh; Lien, Trinh Thi Minh; Farrar, Jeremy; Van Kinh, Nguyen

    2010-01-01

    Abstract Problem Streptococcus suis is a common cause of adult bacterial meningitis in Viet Nam, and possibly other parts of Asia, yet this disabling infection has been largely neglected. Prevention, diagnosis and treatment are relatively straightforward and affordable but, in early 2007, no national diagnostic, case management or prevention guidelines existed in Viet Nam. Approach Enhanced detection of S. suis infections was established in 2007 as part of a collaborative research programme between the National Hospital for Tropical Diseases, a key national hospital with very close links to the Ministry of Health, and a research group affiliated with Oxford University based in Viet Nam. The results were reported directly to policy-makers at the Ministry of Health. Local setting Viet Nam is a low-income country with a health-care system that has seen considerable improvements and increased autonomy. However, parts of the system remain fairly centralized the Ministry of Health. Relevant changes Following the improved detection and reporting of S. suis cases, the Ministry of Health issued guidance to all hospitals in Viet Nam on the clinical and laboratory diagnosis, treatment and prevention of S. suis. A public health laboratory diagnostic service was established at the National Institute of Hygiene and Epidemiology and training courses were conducted for clinicians and microbiologists. Ministry of Health guidance on surveillance and control of communicable diseases was updated to include a section on S. suis. Lessons learnt Research collaborations can efficiently inform and influence national responses if they are well positioned to reach policy-makers. PMID:20539860

  18. TroA of Streptococcus suis Is Required for Manganese Acquisition and Full Virulence▿

    PubMed Central

    Schreur, Paul J. Wichgers; Rebel, Johanna M. J.; Smits, Mari A.; van Putten, Jos P. M.; Smith, Hilde E.

    2011-01-01

    Streptococcus suis causes infections in pigs and occasionally in humans, resulting in manifestations as meningitis, sepsis, arthritis, and septic shock. For survival within the host, S. suis requires numerous nutrients including trace metals. Little is known about the specific proteins involved in metal scavenging in S. suis. In this study we evaluated the role of the putative high-affinity metal binding lipoprotein TroA in metal acquisition and virulence. A mutant strain deficient in the expression of TroA (ΔtroA mutant) was constructed. Growth of the ΔtroA mutant in Todd-Hewitt broth was similar to wild-type growth; however, growth of the ΔtroA mutant in cation-deprived Todd-Hewitt broth and in porcine serum was strongly reduced compared to growth of wild-type bacteria. Supplementing the medium with extra manganese but not with magnesium, zinc, copper, nickel, or iron restored growth to wild-type levels, indicating that TroA is specifically required for growth in environments low in manganese. The ΔtroA mutant also showed increased susceptibility to H2O2, suggesting that TroA is involved in counteracting oxidative stress. Furthermore, the expression of the troA gene was subject to environmental regulation at the transcript level. In a murine S. suis infection model, the ΔtroA mutant displayed a nonvirulent phenotype. These data indicate that S. suis TroA is involved in manganese acquisition and is required for full virulence in mice. PMID:21784944

  19. Different Foreign Genes Incidentally Integrated into the Same Locus of the Streptococcus suis Genome

    PubMed Central

    Sekizaki, Tsutomu; Takamatsu, Daisuke; Osaki, Makoto; Shimoji, Yoshihiro

    2005-01-01

    Some strains of Streptococcus suis possess a type II restriction-modification (RM) system, whose genes are thought to be inserted into the genome between purH and purD from a foreign source by illegitimate recombination. In this study, we characterized the purHD locus of the S. suis genomes of 28 serotype reference strains by DNA sequencing. Four strains contained the RM genes in the locus, as described before, whereas 11 strains possessed other genetic regions of seven classes. The genetic regions contained a single gene or multiple genes that were either unknown or similar to hypothetical genes of other bacteria. The mutually exclusive localization of the genetic regions with the atypical G+C contents indicated that these regions were also acquired from foreign sources. No transposable element or long-repeat sequence was found in the neighboring regions. An alignment of the nucleotide sequences, including the RM gene regions, suggested that the foreign regions were integrated by illegitimate recombination via short stretches of nucleotide identity. By using a thermosensitive suicide plasmid, the RM genes were experimentally introduced into an S. suis strain that did not contain any foreign genes in that locus. Integration of the plasmid into the S. suis genome did not occur in the purHD locus but occurred at various chromosomal loci, where there were 2 to 10 bp of nucleotide identity between the chromosome and the plasmid. These results suggest that various foreign genes described here were incidentally integrated into the same locus of the S. suis genome. PMID:15659665

  20. Streptococcus suis Type 2 Infection in Swine in Ontario: A Review of Clinical and Pathological Presentations

    PubMed Central

    John, V.S. St.; Wilcock, B.; Kierstead, M.

    1982-01-01

    Over an 18 month period Streptococcus suis type 2 was isolated in pure or mixed culture in 19 disease outbreaks in pigs. Morbidity and case fatality were variable. Clinical signs were of a nervous or respiratory disease or of death with no premonitory signs. Gross and microscopic findings included one or more of fibrinous polyserositis, fibrinous or hemmorhagic bronchopneumonia, purulent meningitis, myocardial necrosis, focal myocarditis and valvular endocarditis. Brain, cerebrospinal fluid and lung were most reliable sites for isolation of the organism. PMID:17422123

  1. [Clinical situation, diagnosis and prevention of a Streptococcus suis serotype 7 problem on a farm].

    PubMed

    Unterweger, Christine; Baums, Christoph Georg; Höcher, Martin; Fischer, Louis; Weiss, Astrid; Hennig-Pauka, Isabel

    2014-01-01

    In an Austrian piglet producing farm with 1500 sows a high incidence of meningitis, arthritis and sudden death was recorded in five to eight week old piglets. Overall losses were 1.8%. Streptococcus (S.) suis serotype 7 was detected with an intermediate to high specific bacterial load in all samples taken from brains and joints of 17 untreated piglets with typical clinical signs. All isolates showed an identical spectrum of virulence-associated genes (mrp+, epf-, ofs-, sly-) and expressed a relatively small variant of MRP (Muramidase-Released Protein) called MRPs. A bacterin was produced using four of the S. suis serotype 7 isolates. An untreated and non-vaccinated control group A with 957 piglets, a non-vaccinated but amoxicillin-treated group B with 1012 piglets and an untreated group C with 998 piglets, which was vaccinated twice in the first and third week of life, were compared. Later, an additional group D with 290 piglets was vaccinated twice in the fourth and sixth week of life. Amoxicillin treatment in group B resulted in the lowest mortality and morbidity rate. Furthermore, the incidence of lameness and losses were significantly lower in vaccinated pigs compared to the control group. In an ex vivo blood survival assay, a strong bactericidal effect of the post immune sera of group D animals was found. This is likely due to the presence of specific opsonizing antibodies against S. suis elicited through vaccination and associated with the protective efficacy of the vaccine. PMID:24881269

  2. Virulence genes and genetic diversity of Streptococcus suis serotype 2 isolates from Thailand.

    PubMed

    Maneerat, K; Yongkiettrakul, S; Kramomtong, I; Tongtawe, P; Tapchaisri, P; Luangsuk, P; Chaicumpa, W; Gottschalk, M; Srimanote, P

    2013-11-01

    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

  3. Hemagglutination activities of group B, C, D, and G streptococci: demonstration of novel sugar-specific cell-binding activities in Streptococcus suis.

    PubMed Central

    Kurl, D N; Haataja, S; Finne, J

    1989-01-01

    A total of 378 streptococcal isolates of Lancefield groups B, C, D and G were tested for their ability to hemagglutinate untreated, sialidase-treated, and endo-beta-galactosidase-treated human erythrocytes. Of the 43 strains showing positive hemagglutination, 9 were inhibitable with neutral monosaccharides. Four strains were inhibited with galactose and N-acetylgalactosamine, whereas five were inhibited with galactose only. A third, sialic acid-specific adhesion activity was suggested for two additional strains on the basis of their agglutination of native and endo-beta-galactosidase-treated but not sialidase-treated erythrocytes. All the sugar-specific agglutination activities detected were confined to Streptococcus suis strains of group D streptococci, whereas streptococci of other groups did not exhibit these types of hemagglutination activities. The adhesins were sensitive to proteases and heat treatment, which indicates that they were proteins. The hemagglutinating isolates of S. suis originated from pig brain and lung, human brain, and the tonsils of healthy pigs. No clear correlation with a particular serotype was observed. These results demonstrate the occurrence of unique sugar-specific adherence activities in S. suis, an important pig pathogen with occasional human pathogenicity. PMID:2492258

  4. Explaining the Serological Characteristics of Streptococcus suis Serotypes 1 and 1/2 from Their Capsular Polysaccharide Structure and Biosynthesis.

    PubMed

    Van Calsteren, Marie-Rose; Goyette-Desjardins, Guillaume; Gagnon, Fleur; Okura, Masatoshi; Takamatsu, Daisuke; Roy, René; Gottschalk, Marcelo; Segura, Mariela

    2016-04-15

    The capsular polysaccharide (CPS) is a major virulence factor in many encapsulated pathogens, as it is the case for Streptococcus suis, an important swine pathogen and emerging zoonotic agent. Moreover, the CPS is the antigen at the origin of S. suis classification into serotypes. Hence, analyses of the CPS structure are an essential step to dissect its role in virulence and the serological relations between important serotypes. Here, the CPSs of serotypes 1 and 1/2 were purified and characterized for the first time. Chemical and spectroscopic data gave the following repeating unit sequences: [6)[Neu5Ac(α2-6)GalNAc(β1-4)GlcNAc(β1-3)]Gal(β1-3)Gal(β1-4)Glc(β1-]n (serotype 1) and [4)[Neu5Ac(α2-6)GalNAc(β1-4)GlcNAc(β1-3)]Gal(β1-4)[Gal(α1-3)]Rha(β1-4)Glc(β1-]n (serotype 1/2). The Sambucus nigra lectin, which recognizes the Neu5Ac(α2-6)Gal/GalNAc sequence, showed binding to both CPSs. Compared with previously characterized serotype 14 and 2 CPSs, N-acetylgalactosamine replaces galactose as the sugar bearing the sialic acid residue in the side chain. Serological analyses of the cross-reaction of serotype 1/2 with serotypes 1 and 2 and that between serotypes 1 and 14 suggested that the side chain, and more particularly the terminal sialic acid, constitutes one important epitope for serotypes 1/2 and 2. The side chain is also an important serological determinant for serotype 1, yet sialic acid seems to play a limited role. In contrast, the side chain does not seem to be part of a major epitope for serotype 14. These results contribute to the understanding of the relationship between S. suis serotypes and provide the basis for improving diagnostic tools. PMID:26912653

  5. Crystal Structure and Identification of Two Key Amino Acids Involved in AI-2 Production and Biofilm Formation in Streptococcus suis LuxS

    PubMed Central

    Wang, Yang; Yi, Li; Wang, Shaohui; Fan, Hongjie; Ding, Chan; Mao, Xiang; Lu, Chengping

    2015-01-01

    Streptococcus suis has emerged as an important zoonotic pathogen that causes meningitis, arthritis, septicemia and even sudden death in pigs and humans. Quorum sensing is the signaling network for cell-to-cell communication that bacterial cells can use to monitor their own population density through production and exchange of signal molecules. S-Ribosylhomocysteinase (LuxS) is the key enzyme involved in the activated methyl cycle. Autoinducer 2 (AI-2) is the adduct of borate and a ribose derivative and is produced from S-adenosylhomocysteine (SAH). AI-2 can mediate interspecies communication and in some species facilitate the bacterial behavior regulation such as biofilm formation and virulence in both Gram-positive and Gram-negative bacteria. Here, we reported the overexpression, purification and crystallographic structure of LuxS from S. suis. Our results showed the catalytically active LuxS exists as a homodimer in solution. Inductively coupled plasma-mass spectrometry (ICP-MS) revealed the presence of Zn2+ in LuxS. Although the core structure shares the similar topology with LuxS proteins from other bacterial species, structural analyses and comparative amino acid sequence alignments identified two key amino acid differences in S. suis LuxS, Phe80 and His87, which are located near the substrate binding site. The results of site-directed mutagenesis and enzymology studies confirmed that these two residues affect the catalytic activity of the enzyme. These in vitro results were corroborated in vivo by expression of the LuxS variants in a S. suis ΔluxS strain. The single and two amino acid of LuxS variant decreased AI-2 production and biofilm formation significantly compared to that of the parent strain. Our findings highlight the importance of key LuxS residues that influence the AI-2 production and biofilm formation in S.suis. PMID:26484864

  6. Crystal Structure and Identification of Two Key Amino Acids Involved in AI-2 Production and Biofilm Formation in Streptococcus suis LuxS.

    PubMed

    Wang, Yang; Yi, Li; Wang, Shaohui; Fan, Hongjie; Ding, Chan; Mao, Xiang; Lu, Chengping

    2015-01-01

    Streptococcus suis has emerged as an important zoonotic pathogen that causes meningitis, arthritis, septicemia and even sudden death in pigs and humans. Quorum sensing is the signaling network for cell-to-cell communication that bacterial cells can use to monitor their own population density through production and exchange of signal molecules. S-Ribosylhomocysteinase (LuxS) is the key enzyme involved in the activated methyl cycle. Autoinducer 2 (AI-2) is the adduct of borate and a ribose derivative and is produced from S-adenosylhomocysteine (SAH). AI-2 can mediate interspecies communication and in some species facilitate the bacterial behavior regulation such as biofilm formation and virulence in both Gram-positive and Gram-negative bacteria. Here, we reported the overexpression, purification and crystallographic structure of LuxS from S. suis. Our results showed the catalytically active LuxS exists as a homodimer in solution. Inductively coupled plasma-mass spectrometry (ICP-MS) revealed the presence of Zn2+ in LuxS. Although the core structure shares the similar topology with LuxS proteins from other bacterial species, structural analyses and comparative amino acid sequence alignments identified two key amino acid differences in S. suis LuxS, Phe80 and His87, which are located near the substrate binding site. The results of site-directed mutagenesis and enzymology studies confirmed that these two residues affect the catalytic activity of the enzyme. These in vitro results were corroborated in vivo by expression of the LuxS variants in a S. suis ΔluxS strain. The single and two amino acid of LuxS variant decreased AI-2 production and biofilm formation significantly compared to that of the parent strain. Our findings highlight the importance of key LuxS residues that influence the AI-2 production and biofilm formation in S.suis. PMID:26484864

  7. SBP2 plays an important role in the virulence changes of different artificial mutants of Streptococcus suis.

    PubMed

    Yu, Yanfei; Qian, Yunyun; Du, Dechao; Xu, Chenyang; Dai, Chen; Li, Quan; Liu, Hanze; Shao, Jing; Wu, Zongfu; Zhang, Wei

    2016-05-24

    Streptococcus suis (SS) is an important bacterial zoonotic pathogen, which can cause infections in pigs and humans. However, the pathogenesis of this bacterium remains unclear, even though some putative virulence factors (VFs) have been reported. Comparative proteomics could be used to identify markers that can distinguish bacterial strains with different virulence; however, the application of this method is restricted by the genome diversities existing in different strains. In this study, two mutants, WT ΔpepT and WT ΔrfeA, which were generated from the same wild-type (WT) strain, ZY05719, and showed opposite virulence tendencies, were constructed. Combining two proteomics assays, two-dimensional difference gel electrophoresis (2D-DIGE) and label-free proteomics, we identified 38 differentially abundant proteins in the mutants compared with their parent, including five known VFs of S. suis and 33 novel elements. One of the novel proteins, a putative pilus protein, named SBP2, was considered as the most promising VF, because SBP2 was not only linked with the known VFs in the virulence interaction network and was proposed to be located on the cell surface, but also showed enriched distribution among highly virulent strains of SS. SBP2 could also bind fibronectin and laminin, two important extracellular matrix proteins of the host, to facilitate the process of adhesion. Thus, spb2 was identified as encoding a promising virulence-associated candidate associated with the pathogenesis of SS, and a comprehensive virulence interaction network of SS was established for the first time. PMID:27077729

  8. Dynamic Virus-Bacterium Interactions in a Porcine Precision-Cut Lung Slice Coinfection Model: Swine Influenza Virus Paves the Way for Streptococcus suis Infection in a Two-Step Process

    PubMed Central

    Meng, F.; Wu, N. H.; Nerlich, A.; Herrler, G.; Seitz, M.

    2015-01-01

    Swine influenza virus (SIV) and Streptococcus suis are common pathogens of the respiratory tract in pigs, with both being associated with pneumonia. The interactions of both pathogens and their contribution to copathogenesis are only poorly understood. In the present study, we established a porcine precision-cut lung slice (PCLS) coinfection model and analyzed the effects of a primary SIV infection on secondary infection by S. suis at different time points. We found that SIV promoted adherence, colonization, and invasion of S. suis in a two-step process. First, in the initial stages, these effects were dependent on bacterial encapsulation, as shown by selective adherence of encapsulated, but not unencapsulated, S. suis to SIV-infected cells. Second, at a later stage of infection, SIV promoted S. suis adherence and invasion of deeper tissues by damaging ciliated epithelial cells. This effect was seen with a highly virulent SIV subtype H3N2 strain but not with a low-virulence subtype H1N1 strain, and it was independent of the bacterial capsule, since an unencapsulated S. suis mutant behaved in a way similar to that of the encapsulated wild-type strain. In conclusion, the PCLS coinfection model established here revealed novel insights into the dynamic interactions between SIV and S. suis during infection of the respiratory tract. It showed that at least two different mechanisms contribute to the beneficial effects of SIV for S. suis, including capsule-mediated bacterial attachment to SIV-infected cells and capsule-independent effects involving virus-mediated damage of ciliated epithelial cells. PMID:25916988

  9. Genetic and virulence-phenotype characterization of serotypes 2 and 9 of Streptococcus suis swine isolates.

    PubMed

    Blume, Verena; Luque, Inmaculada; Vela, Ana I; Borge, Carmen; Maldonado, Alfonso; Domínguez, Lucas; Tarradas, Carmen; Fernández-Garayzábal, José F

    2009-09-01

    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. PMID:19784922

  10. Contribution of Eukaryotic-Type Serine/Threonine Kinase to Stress Response and Virulence of Streptococcus suis

    PubMed Central

    Zhu, Haodan; Zhou, Junming; Ni, Yanxiu; Yu, Zhengyu; Mao, Aihua; Hu, Yiyi; Wang, Wei; Zhang, Xuehan; Wen, Libin; Li, Bin; Wang, Xiaomin; Yu, Yang; Lv, Lixin; Guo, Rongli; Lu, Chengping; He, Kongwang

    2014-01-01

    Streptococcus suis serotype 2 (SS2) is an important swine and human pathogen responsible for septicemia and meningitis. The bacterial homologues of eukaryotic-type serine/threonine kinases (ESTKs) have been reported to play critical roles in various cellular processes. To investigate the role of STK in SS2, an isogenic stk mutant strain (Δstk) and a complemented strain (CΔstk) were constructed. The Δstk showed a significant decrease in adherence to HEp-2 cells, compared with the wild-type strain, and a reduced survival ratio in whole blood. In addition, the Δstk exhibited a notable reduced tolerance of environmental stresses including high temperature, acidic pH, oxidative stress, and high osmolarity. More importantly, the Δstk was attenuated in both the CD1 mouse and piglet models of infection. The results of quantitative reverse transcription-PCR (qRT-PCR) analysis indicated that the expressions of a few genes involving in adherence, stress response and virulence were clearly decreased in the Δstk mutant strain. Our data suggest that SsSTK is required for virulence and stress response in SS2. PMID:24637959

  11. GidA, a tRNA Modification Enzyme, Contributes to the Growth, and Virulence of Streptococcus suis Serotype 2

    PubMed Central

    Gao, Ting; Tan, Meifang; Liu, Wanquan; Zhang, Chunyan; Zhang, Tengfei; Zheng, Linlin; Zhu, Jiawen; Li, Lu; Zhou, Rui

    2016-01-01

    Glucose-inhibited division protein (GidA), is a tRNA modification enzyme functioning together with MnmE in the addition of a carboxymethylaminomethyl group to position 5 of the anticodon wobble uridine of tRNA. Here, we report a GidA homolog from a Chinese isolate SC-19 of the zoonotic Streptococcus suis serotype 2 (SS2). gidA disruption led to a defective growth, increased capsule thickness, and reduced hemolytic activity. Moreover, the gidA deletion mutant (ΔgidA) displayed reduced mortality and bacterial loads in mice, reduced ability of adhesion to and invasion in epithelial cells, and increased sensitivity to phagocytosis. The iTRAQ analysis identified 372 differentially expressed (182 up- and 190 down-regulated) proteins in ΔgidA and SC-19. Numerous DNA replication, cell division, and virulence associated proteins were downregulated, whereas many capsule synthesis enzymes were upregulated by gidA disruption. This is consistent with the phenotypes of the mutant. Thus, GidA is a translational regulator that plays an important role in the growth, cell division, capsule biosynthesis, and virulence of SS2. Our findings provide new insight into the regulatory function of GidA in bacterial pathogens. PMID:27148493

  12. Avian influenza virus, Streptococcus suis serotype 2, severe acute respiratory syndrome-coronavirus and beyond: molecular epidemiology, ecology and the situation in China

    PubMed Central

    Ma, Ying; Feng, Youjun; Liu, Di; Gao, George F.

    2009-01-01

    The outbreak and spread of severe acute respiratory syndrome-associated coronavirus and the subsequent identification of its animal origin study have heightened the world's awareness of animal-borne or zoonotic pathogens. In addition to SARS, the highly pathogenic avian influenza virus (AIV), H5N1, and the lower pathogenicity H9N2 AIV have expanded their host ranges to infect human beings and other mammalian species as well as birds. Even the ‘well-known’ reservoir animals for influenza virus, migratory birds, became victims of the highly pathogenic H5N1 virus. Not only the viruses, but bacteria can also expand their host range: a new disease, streptococcal toxic shock syndrome, caused by human Streptococcus suis serotype 2 infection, has been observed in China with 52 human fatalities in two separate outbreaks (1998 and 2005, respectively). Additionally, enterohaemorrhagic Escherichia coli O157:H7 infection has increased worldwide with severe disease. Several outbreaks and sporadic isolations of this pathogen in China have made it an important target for disease control. A new highly pathogenic variant of porcine reproductive and respiratory syndrome virus (PRRSV) has been isolated in both China and Vietnam recently; although PRRSV is not a zoonotic human pathogen, its severe outbreaks have implications for food safety. All of these pathogens occur in Southeast Asia, including China, with severe consequences; therefore, we discuss the issues in this article by addressing the situation of the zoonotic threat in China. PMID:19687041

  13. Avian influenza virus, Streptococcus suis serotype 2, severe acute respiratory syndrome-coronavirus and beyond: molecular epidemiology, ecology and the situation in China.

    PubMed

    Ma, Ying; Feng, Youjun; Liu, Di; Gao, George F

    2009-09-27

    The outbreak and spread of severe acute respiratory syndrome-associated coronavirus and the subsequent identification of its animal origin study have heightened the world's awareness of animal-borne or zoonotic pathogens. In addition to SARS, the highly pathogenic avian influenza virus (AIV), H5N1, and the lower pathogenicity H9N2 AIV have expanded their host ranges to infect human beings and other mammalian species as well as birds. Even the 'well-known' reservoir animals for influenza virus, migratory birds, became victims of the highly pathogenic H5N1 virus. Not only the viruses, but bacteria can also expand their host range: a new disease, streptococcal toxic shock syndrome, caused by human Streptococcus suis serotype 2 infection, has been observed in China with 52 human fatalities in two separate outbreaks (1998 and 2005, respectively). Additionally, enterohaemorrhagic Escherichia coli O157:H7 infection has increased worldwide with severe disease. Several outbreaks and sporadic isolations of this pathogen in China have made it an important target for disease control. A new highly pathogenic variant of porcine reproductive and respiratory syndrome virus (PRRSV) has been isolated in both China and Vietnam recently; although PRRSV is not a zoonotic human pathogen, its severe outbreaks have implications for food safety. All of these pathogens occur in Southeast Asia, including China, with severe consequences; therefore, we discuss the issues in this article by addressing the situation of the zoonotic threat in China. PMID:19687041

  14. Lysogenic Streptococcus suis isolate SS2-4 containing prophage SMP showed increased mortality in zebra fish compared to the wild-type isolate.

    PubMed

    Tang, Fang; Zhang, Wei; Lu, Chengping

    2013-01-01

    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

  15. The Role of Porcine Monocyte Derived Dendritic Cells (MoDC) in the Inflammation Storm Caused by Streptococcus suis Serotype 2 Infection

    PubMed Central

    Liu, Jin; Tian, Zhong-Yuan; Xiao, Yun-Cai; Wang, Xi-Liang; Jin, Mei-Lin; Shi, De-Shi

    2016-01-01

    Background Streptococcus suis is an important swine pathogen and zoonotic agent. Infection with this highly pathogenic strain can cause streptococcal toxic shock-like syndrome (STSLS), characterized by a Th-1 inflammatory cytokine storm, and a high mortality rate. Monocyte derived dendritic cells (MoDCs) are known to stimulate Th-1 cell differentiation, but the role of MoDCs in STSLS remains to be elucidated. Methodology and Findings Porcine CD14-positive monocytes, purified from peripheral blood mononuclear cells (PBMCs), were used to generate MoDCs using granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4). Highly pure MoDCs were generated, as proved by their morphology, phenotype analysis, phagocytic ability, and induction of T cells proliferation. The MoDCs were further stimulated by the virulent S. suis serotype 2 (SS2) SC19 strain which triggered a strong release of several pro-inflammatory cytokines, including IL-1β, IL-8, TNF-α, IFN-γ, and IL-12. Furthermore, the stimulated MoDCs induced CD4+ T cell differentiation towards Th-1 cells in vitro. Conclusions The results of this study indicated that the porcine MoDCs stimulated by SS2 could release high levels of Th-1 inflammatory cytokines and induce CD4+ T cell differentiation towards Th-1 cells. Hence, it is likely that porcine MoDCs play an important role in the STSLS caused by SS2. PMID:26974437

  16. Development of loop-mediated isothermal amplification to detect Streptococcus suis and its application to retail pork meat in Japan.

    PubMed

    Arai, Sakura; Tohya, Mari; Yamada, Ryoko; Osawa, Ro; Nomoto, Ryohei; Kawamura, Yoshiaki; Sekizaki, Tsutomu

    2015-09-01

    We here developed a novel loop-mediated isothermal amplification (LAMP) method to detect Streptococcus suis in raw pork meat. This method, designated LAMPSS, targeted the recombination/repair protein (recN) gene of S. suis and detected all serotypes of S. suis, except those taxonomically removed from authentic S. suis, i.e., serotypes 20, 22, 26, 32, 33, and 34. The specificity of LAMPSS was confirmed and its detection limit was 5.4cfu/reaction. Among the 966 raw pork meat samples examined, including sliced pork, minced pork, and the liver, tongue, heart, and small intestine, 255 samples tested positive with LAMPSS. The rate of contamination was higher in the organs than in pork. No significant difference was observed in the total bacterial count between LAMPSS-positive and -negative samples. The number of shops that provided LAMPSS-positive pork was slightly higher in those that sold swine organs and pork than in those that sold only pork, suggesting that cross contamination occurred from the organs to pork. Among the 255 which tested positive for LAMPSS, only 47 samples tested positive for the previously described LAMP specific for S. suis serotype 2. Two isolates of S. suis serotype 2, belonging to sequence type 28, which is potentially hazardous to humans, as well as those of some other serotypes were obtained from 19 out of 47 samples by combining LAMP with a replica plating method. These results suggest that LAMPSS will be a useful tool for the surveillance of raw pork meat in the retail market. PMID:26043307

  17. Genetic diversity of Streptococcus suis serotypes 2 and 1/2 isolates recovered from carrier pigs in closed herds

    PubMed Central

    Martinez, Gabriela; Harel, Josée; Lacouture, Sonia; Gottschalk, Marcelo

    2002-01-01

    The aim of this study was to compare, by randomly amplified polymorphic DNA (RAPD), the diversity of Streptococcus suis serotypes 1/2 and 2 isolates recovered at slaughter houses from the tonsils of clinically healthy pigs. The pigs belonged to herds with or without clinical signs of S. suis disease. Overall, a low diversity was observed among isolates of serotype 1/2. A representative isolate recovered from a diseased animal presented a relatively high similarity (85%), with most isolates recovered from carrier pigs, from herds either with or without clinical signs of S. suis disease. For serotype 2 isolates, a relatively high degree of heterogeneity was observed in the whole population. Two subpopulations were observed for serotype 2 isolates, which arose from herds with clinical signs. Interestingly, the representative isolate coming from the diseased pig was included in a small closed cluster, with 2 isolates recovered from carrier pigs belonging to the same herd. On the other hand, most of the S. suis serotype 2 isolates originating from herds with no history of S. suis disease, were closely related (90% similarity). Furthermore, they presented different RAPD patterns from those originating from animals from the herd presenting S. suis clinical signs due to this serotype. Results suggest that, in the herds studied, clinical manifestations due to serotype 2 are probably related to the virulence of a specific isolate. Conversely, for the herd affected with serotype 1/2, clinical manifestations of the disease were more likely to be the result of inherent herd factors than the virulence of the specific isolate. PMID:12418779

  18. A novel virulence-associated protein, vapE, in Streptococcus suis serotype 2.

    PubMed

    Ji, Xue; Sun, Yang; Liu, Jun; Zhu, Lingwei; Guo, Xuejun; Lang, Xulong; Feng, Shuzhang

    2016-03-01

    Streptococcus suis serotype 2 (SS2) is an important pathogen that affects pigs. However, neither its virulence nor its pathogenesis of infection has yet to be fully elucidated. The present study identifies a novel virulence‑associated protein E gene (vapE) of SS2. To investigate the importance of vapE in SS2 infection, a vapE knock‑out mutant based on SS2 wild‑type strain ZY458 was designated 458ΔvapE. 458ΔvapE was generated through homologous recombination, using a combined plasmid with a vapE knock‑out fragment and a pSET4s suicide vector. Additionally, the 458ΔvapE strain was transformed by a pAT18 shuttle plasmid containing the vapE gene. A functionally complemented strain for the vapE gene [termed 458ΔvapE (pvapE)] was constructed. Animal experiments demonstrated that mice infected with ZY458 and 458ΔvapE (pvapE) exhibited severe clinical symptoms, including depression, apathy, fever, anorexia, emaciation, swollen eyes and neural disorders, and died within two days of infection. All mice infected with ZY458, and 85% of mice infected with 458ΔvapE (pvapE), died within 2 days of infection. In contrast, mice inoculated with 458ΔvapE exhibited only mild clinical symptoms in the first 2 days following infection, and recovered within a week. A bacterial colonization assay demonstrated the ability of the 458ΔvapE mutant SS2 strain to colonize the heart, liver, spleen, lung and kidney of infected mice. PCR analysis of the vapE gene revealed that functional vapE was detected in virulent strains, but not in avirulent and carrier strains of S. suis SS2. These findings indicate that vapE is important for the pathogenesis of SS2. PMID:26821177

  19. Streptococcus suis Type 2 SSU0587 Protein is a Beta-Galactosidase That Contributes to Bacterial Adhesion but Not to Virulence in Mice

    PubMed Central

    TANG, Yulong; ZHANG, Xiaoyan; YIN, Yulong; HARDWIDGE, Philip R.; FANG, Weihuan

    2014-01-01

    ABSTRACT Bacterial surface proteins play key roles in virulence and often contribute to bacterial adhesion and invasion. We discovered that the Streptococcus suis type 2 (SS2) gene SSU0587 encodes a protein of 1,491 amino acids that possesses β-galactosidase activity. The surface association of the protein was dependent upon sortase activity. Deleting SSU0587 from clinical SS2 isolate JX081101 caused a loss of both β-galactosidase activity and adherence to microvascular endothelial cells. Deleting SSU0587 had no measurable impact on either invasion of microvascular endothelial cells or on virulence in a murine infection model, although the concentration of JX081101ΔSSU0587 was reduced in the brains of infected mice, as compared with the pathogen loads of the wild-type strain. PMID:24670993

  20. Streptococcus suis type 2 SSU0587 protein is a beta-galactosidase that contributes to bacterial adhesion but not to virulence in mice.

    PubMed

    Tang, Yulong; Zhang, Xiaoyan; Yin, Yulong; Hardwidge, Philip R; Fang, Weihuan

    2014-07-01

    Bacterial surface proteins play key roles in virulence and often contribute to bacterial adhesion and invasion. We discovered that the Streptococcus suis type 2 (SS2) gene SSU0587 encodes a protein of 1,491 amino acids that possesses β-galactosidase activity. The surface association of the protein was dependent upon sortase activity. Deleting SSU0587 from clinical SS2 isolate JX081101 caused a loss of both β-galactosidase activity and adherence to microvascular endothelial cells. Deleting SSU0587 had no measurable impact on either invasion of microvascular endothelial cells or on virulence in a murine infection model, although the concentration of JX081101ΔSSU0587 was reduced in the brains of infected mice, as compared with the pathogen loads of the wild-type strain. PMID:24670993

  1. Streptococcus suis II immunoassay based on thorny gold nanoparticles and surface enhanced Raman scattering.

    PubMed

    Chen, Kun; Han, Heyou; Luo, Zhihui

    2012-03-01

    An immunoassay based on surface enhanced Raman scattering (SERS) spectroscopy was developed to detect muramidase released protein (MRP) antibody against Streptococcus suis II (SS2) utilizing thorny gold nanoparticles (tAuNPs) as SERS substrates. Initially, tAuNPs with multi-branches were prepared by the seed-mediated growth method in the absence of templates and surfactants, facilitating p-mercaptobenzoic acid (pMBA) conjugation covalently onto the tAuNPs through S-Au bonds. The obtained immuno-SERS tag affording strong Raman signals made it possible to establish an application of indirect detection of the MRP antibody against SS2 with a sandwich assay at a highly sensitive level. The Raman intensity at 1588 cm(-1) was proportional to the logarithm of the concentration of MRP antibody in the range of 10 pg mL(-1) to 0.1 μg mL(-1). The detection sensitivity was significantly improved to 0.1 pg mL(-1) by using the immuno-SERS tags. Furthermore, the proposed SERS approach was applied to detect MRP antibody in pig serum samples, and the results agreed well with those of ELISA, indicating great potential for clinical application in diagnostic immunoassays. PMID:22282767

  2. Correlation between PFGE Groups and mrp/epf/sly Genotypes of Human Streptococcus suis Serotype 2 in Northern Thailand.

    PubMed

    Tharavichitkul, Prasit; Wongsawan, Kanreuthai; Takenami, Naoki; Pruksakorn, Sumalee; Fongcom, Achara; Gottschalk, Marcelo; Khanthawa, Banyong; Supajatura, Volaluk; Takai, Shinji

    2014-01-01

    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

  3. ApuA, a multifunctional alpha-glucan-degrading enzyme of Streptococcus suis, mediates adhesion to porcine epithelium and mucus.

    PubMed

    Ferrando, Maria Laura; Fuentes, Susana; de Greeff, Astrid; Smith, Hilde; Wells, Jerry M

    2010-09-01

    We have identified apuA in Streptococcus suis, which encodes a bifunctional amylopullulanase with conserved alpha-amylase and pullulanase substrate-binding domains and catalytic motifs. ApuA exhibited properties typical of a Gram-positive surface protein, with a putative signal sequence and LPKTGE cell-wall-anchoring motif. A recombinant protein containing the predicted N-terminal alpha-amylase domain of ApuA was shown to have alpha-(1,4) glycosidic activity. Additionally, an apuA mutant of S. suis lacked the pullulanase alpha-(1,6) glycosidic activity detected in a cell-surface protein extract of wild-type S. suis. ApuA was required for normal growth in complex medium containing pullulan as the major carbon source, suggesting that this enzyme plays a role in nutrient acquisition in vivo via the degradation of glycogen and food-derived starch in the nasopharyngeal and oral cavities. ApuA was shown to promote adhesion to porcine epithelium and mucus in vitro, highlighting a link between carbohydrate utilization and the ability of S. suis to colonize and infect the host. PMID:20522493

  4. A Fur-like protein PerR regulates two oxidative stress response related operons dpr and metQIN in Streptococcus suis

    PubMed Central

    2012-01-01

    Background Metal ions are important micronutrients in cellular metabolism, but excess ions that cause toxic reactive oxygen species are harmful to cells. In bacteria, Fur family proteins such as Fur, Zur and PerR manage the iron and zinc uptake and oxidative stress responses, respectively. The single Fur-like protein (annotated as PerR) in Streptococcus suis has been demonstrated to be involved in zinc and iron uptake in previous studies, but the reports on oxidative stress response and gene regulation are limited. Results In the present study, the perR gene deletion mutant ΔperR was constructed in Streptococcus suis serotype 2 strain SC-19, and the mutant strain ΔperR exhibited less sensitivity to H2O2 stress compared to the wild-type. The dpr and metQIN were found to be upregulated in the ΔperR strain compared with SC-19. Electrophoretic mobility shift assays showed that the promoters of dpr and metQIN could be bound by the PerR protein. These results suggest that dpr and metQIN are members of the PerR regulon of S. suis. dpr encodes a Dps-like peroxide resistance protein, and the dpr knockout strains (Δdpr and ΔdprΔperR) were highly sensitive to H2O2. MetQIN is a methionine transporter, and the increased utilization of methionine in the ΔperR strain indirectly affected the peroxide resistance. Using a promoter–EGFP gene fusion reporting system, we found that the PerR regulon was induced by H2O2, and the induction was modulated by metal ions. Finally, we found that the pathogenicity of the perR mutant was attenuated and easily cleared by mice. Conclusions These data strongly suggest that the Fur-like protein PerR directly regulates dpr and metQIN and plays a crucial role in oxidative stress response in S. suis. PMID:22646062

  5. Serotype- and virulence-associated gene profile of Streptococcus suis isolates from pig carcasses in Chiang Mai Province, Northern Thailand.

    PubMed

    Wongsawan, Kanruethai; Gottschalk, Marcelo; Tharavichitkul, Prasit

    2015-02-01

    In this present study, the serotype of 40 Streptococcus suis isolates from submaxillary glands of pig carcasses sold in wet markets in Chiang Mai Province, northern Thailand, was investigated. Eleven serotypes, including types 2, 3, 4, 5, 7, 8, 9, 17, 21, 22 and 31, were found in the isolates by a Multiplex PCR combined with serum agglutination. Of the eleven serotypes present, type 3 was the most prevalent, while types 2, 4, 5 and 21 were of primary interest due to their human isolate serotype. The mrp+/epf - /sly - genotype was found to be the most prevalent genotype. This study indicates the importance of effective control of human S. suis infection due to raw pork or pig carcass handling in northern Thailand. PMID:25367105

  6. In Vivo Pharmacodynamics of Cefquinome in a Neutropenic Mouse Thigh Model of Streptococcus suis Serotype 2 at Varied Initial Inoculum Sizes

    PubMed Central

    Guo, Chunna; Liao, Xiaoping; Wang, Mingru; Wang, Feng; Yan, Chaoqun; Xiao, Xia; Sun, Jiang

    2015-01-01

    Streptococcus suis serotype 2 is an emerging zoonotic pathogen and causes severe disease in both pigs and human beings. Cefquinome (CEQ), a fourth-generation cephalosporin, exhibits broad-spectrum activity against Gram-positive bacteria such as S. suis. This study evaluated the in vitro and in vivo antimicrobial activities of CEQ against four strains of S. suis serotype 2 in a murine neutropenic thigh infection model. We investigated the effect of varied inoculum sizes (106 to 108 CFU/thigh) on the pharmacokinetic (PK)/pharmacodynamic (PD) indices and magnitudes of a particular PK/PD index or dose required for efficacy. Dose fractionation studies included total CEQ doses ranging from 0.625 to 640 mg/kg/24 h. Data were analyzed via a maximum effect (Emax) model using nonlinear regression. The PK/PD studies demonstrated that the percentage of time that serum drug levels were above the MIC of free drug (%ƒT>MIC) in a 24-h dosing interval was the primary index driving the efficacy of both inoculum sizes (R2 = 91% and R2 = 63%). CEQ doses of 2.5 and 40 mg/kg body weight produced prolonged postantibiotic effects (PAEs) of 2.45 to 8.55 h. Inoculum sizes had a significant influence on CEQ efficacy. Compared to the CEQ exposure and dosages in tests using standard inocula, a 4-fold dose (P = 0.006) and a 2-fold exposure time (P = 0.01) were required for a 1-log kill using large inocula of 108 CFU/thigh. PMID:26666923

  7. Polar Invasion and Translocation of Neisseria meningitidis and Streptococcus suis in a Novel Human Model of the Blood-Cerebrospinal Fluid Barrier

    PubMed Central

    Schwerk, Christian; Papandreou, Thalia; Schuhmann, Daniel; Nickol, Laura; Borkowski, Julia; Steinmann, Ulrike; Quednau, Natascha; Stump, Carolin; Weiss, Christel; Berger, Jürgen; Wolburg, Hartwig; Claus, Heike; Vogel, Ulrich; Ishikawa, Hiroshi

    2012-01-01

    Acute bacterial meningitis is a life-threatening disease in humans. Discussed as entry sites for pathogens into the brain are the blood-brain and the blood-cerebrospinal fluid barrier (BCSFB). Although human brain microvascular endothelial cells (HBMEC) constitute a well established human in vitro model for the blood-brain barrier, until now no reliable human system presenting the BCSFB has been developed. Here, we describe for the first time a functional human BCSFB model based on human choroid plexus papilloma cells (HIBCPP), which display typical hallmarks of a BCSFB as the expression of junctional proteins and formation of tight junctions, a high electrical resistance and minimal levels of macromolecular flux when grown on transwell filters. Importantly, when challenged with the zoonotic pathogen Streptococcus suis or the human pathogenic bacterium Neisseria meningitidis the HIBCPP show polar bacterial invasion only from the physiologically relevant basolateral side. Meningococcal invasion is attenuated by the presence of a capsule and translocated N. meningitidis form microcolonies on the apical side of HIBCPP opposite of sites of entry. As a functionally relevant human model of the BCSFB the HIBCPP offer a wide range of options for analysis of disease-related mechanisms at the choroid plexus epithelium, especially involving human pathogens. PMID:22253884

  8. Overexpression of an ABC transporter and mutations of GyrA, GyrB, and ParC in contributing to high-level ciprofloxacin resistance in Streptococcus suis type 2.

    PubMed

    Yao, Jie; Shang, Kexin; Huang, Jinhu; Ran, Wei; Kashif, Jam; Wang, Liping

    2014-04-01

    Streptococcus suis is a pathogen of zoonotic diseases. Moreover, the emergence of fluoro-quinolones (FQs) resistance in this pathogen has severe consequences for pigs and human health. In this study, the molecular mechanism of FQs resistance in S. suis type 2 (SS2) sensitive strains isolated from pigs was assessed after in vitro induction of resistance against the most frequently used FQs: ciprofloxacin, norfloxacin, and enrofloxacin. Proteome analysis, sequencing and real-time RT-PCR results strongly established an overexpression of an ABC transporter protein (other than SatAB) and topoisomerase mutations in GyrA (Ser81Arg), GyrB (Glu354Lys), and ParC (Ser79Phe) in contributing to high level ciprofloxacin resistance in SS2. Due to the overexpression of the ABC transporter, intracellular ciprofloxacin concentrations were significantly lower in the resistant strains than those of sensitive strains after 20, 35, and 60 min exposures to ciprofloxacin (p < 0.05). It was concluded that improper use of FQs is one of the main causes of the emergence of this zoonotic pathogen as a multiresistant organism against commonly used antibiotics. The existence of an efflux-like protein is an incentive to find new drug targets to avoid the spread of FQs-resistant S. suis isolates in pigs and the human population. PMID:24815385

  9. Characterization of the Streptococcus suis XerS recombinase and its unconventional cleavage of the difSL site.

    PubMed

    Leroux, Maxime; Jia, Fuli; Szatmari, George

    2011-11-01

    XerC and XerD are members of the tyrosine recombinase family and mediate site-specific recombination that contributes to the stability of circular chromosomes in bacteria by resolving plasmid multimers and chromosome dimers to monomers prior to cell division. Homologues of xerC/xerD genes have been found in many bacteria, and in the lactococci and streptococci, a single recombinase called XerS can perform the functions of XerC and XerD. The xerS gene of Streptococcus suis was cloned, overexpressed and purified as a maltose-binding protein (MBP) fusion. The purified MBP-XerS fusion showed specific DNA-binding activity to both halves of the dif site of S. suis, and covalent protein-DNA complexes were also detected with dif site suicide substrates. These substrates were also cleaved in a specific fashion by MBP-XerS, generating cleavage products separated by an 11-bp spacer region, unlike the traditional 6-8-bp spacer observed in most tyrosine recombinases. Furthermore, xerS mutants of S. suis showed significant growth and morphological changes. PMID:22092814

  10. Virulence Studies of Different Sequence Types and Geographical Origins of Streptococcus suis Serotype 2 in a Mouse Model of Infection.

    PubMed

    Auger, Jean-Philippe; Fittipaldi, Nahuel; Benoit-Biancamano, Marie-Odile; Segura, Mariela; Gottschalk, Marcelo

    2016-01-01

    Multilocus sequence typing previously identified three predominant sequence types (STs) of Streptococcus suis serotype 2: ST1 strains predominate in Eurasia while North American (NA) strains are generally ST25 and ST28. However, ST25/ST28 and ST1 strains have also been isolated in Asia and NA, respectively. Using a well-standardized mouse model of infection, the virulence of strains belonging to different STs and different geographical origins was evaluated. Results demonstrated that although a certain tendency may be observed, S. suis serotype 2 virulence is difficult to predict based on ST and geographical origin alone; strains belonging to the same ST presented important differences of virulence and did not always correlate with origin. The only exception appears to be NA ST28 strains, which were generally less virulent in both systemic and central nervous system (CNS) infection models. Persistent and high levels of bacteremia accompanied by elevated CNS inflammation are required to cause meningitis. Although widely used, in vitro tests such as phagocytosis and killing assays require further standardization in order to be used as predictive tests for evaluating virulence of strains. The use of strains other than archetypal strains has increased our knowledge and understanding of the S. suis serotype 2 population dynamics. PMID:27409640

  11. Streptococcus pluranimalium: A novel human pathogen?

    PubMed Central

    Aryasinghe, Lasanthi; Sabbar, Saweera; Kazim, Yasmin; Awan, Liaqat Mahmood; Khan, Hammad Khan Nadir

    2014-01-01

    INTRODUCTION We present the first case of a subdural empyema caused by Streptococcus pluranimalium, in a healthy adolescent male as a possible complication of subclinical frontal sinusitis. Clinical features, diagnostic approach and management of subdural empyema are discussed. PRESENTATION OF CASE A 17-year-old male with a 2 day history of headache and nausea was referred to our Emergency Department (ED) as a case of possible meningitis. He was afebrile, lethargic and drowsy with significant neck stiffness on examination. Computerized tomography (CT) revealed a large frontotemporoparietal subdural fluid collection with significant midline shift. Subsequent contrast-enhanced CT established the presence of intracranial empyema; the patient underwent immediate burr-hole evacuation of the pus and received 7 weeks of intravenous antibiotics, recovering with no residual neurological deficit. DISCUSSION The diagnosis of subdural empyema as a complication of asymptomatic sinusitis in an immunocompetent patient with no history of fever or upper respiratory symptoms was unanticipated. Furthermore, the organism Streptococcus pluranimalium that was cultured from the pus has only been documented twice previously in medical literature to cause infection in humans, as it is primarily a pathogen responsible for infection in bovine and avian species. CONCLUSION Subdural empyema represents a neurosurgical emergency and if left untreated is invariably fatal. Rapid diagnosis, surgical intervention and intensive antibiotic therapy improve both morbidity and mortality. PMID:25437686

  12. Screening of virulence-associated genes as a molecular typing method for characterization of Streptococcus suis isolates recovered from wild boars and pigs.

    PubMed

    Sánchez Del Rey, Verónica; Fernández-Garayzábal, José F; Domínguez, Lucas; Gottschalk, Marcelo; Vela, Ana I

    2016-03-01

    Streptococcus suis is an important zoonotic pathogen associated with a wide range of diseases in pigs, but has also been isolated from wild animals such as rabbits and wild boars. In the current study, 126 S. suis isolates recovered from pigs (n = 85) and wild boars (n = 41) were tested by polymerase chain reaction (PCR) for the presence of nine virulence-associated genes. S. suis isolates from wild boars were differentiated by the lower detection rates of the epf, sly, mrp, sao and dltA genes (0%, 2.4%, 2.4%, 4.8% and 21.9%, respectively) compared with the isolates from pigs (56.5%, 75.3%, 56.5%, 88.2.0% and 88.2%, respectively). The differences in the content of these virulence-associated genes were statistically significant (P < 0.05). There was a correlation between the variants saoM and saoL and serotypes 2 and 9, respectively (P < 0.05). Isolates were classified into 31 virulence-associated gene profiles (VPs). Ten VPs were detected among wild boar isolates and 22 VPs among pig isolates, with only two VPs common to wild boars and pigs. The predominant VPs among isolates from wild boars (VP1, VP7) were different from those observed in pig isolates (VP16 and VP26). VP16 was detected exclusively in clinical pig isolates of serotype 9 and VP26 was detected in 71.4% of the serotype 2 clinical pig isolates. Further multilocus sequence typing (MLST) analysis showed a significant correlation association between certain VPs and STs (VP16 and VP17 with ST123 and ST125 and VP26 with ST1). In conclusion, the current study showed that combination of virulence-associated gene profiling and MLST analysis may provide more information of the relatedness of the S. suis strains from different animal species that could be useful for epidemiological purposes. PMID:26831161

  13. Transcellular migration of neutrophil granulocytes through the blood-cerebrospinal fluid barrier after infection with Streptococcus suis

    PubMed Central

    2011-01-01

    Background A critical point during the course of bacterial meningitis is the excessive influx of polymorphnuclear neutrophils (PMNs) from the blood into the brain. Both paracellular and transcellular routes of leukocyte transmigration through the blood-brain barrier have been described in CNS diseases so far. Thus, we investigated the mechanism of PMN transmigration through the blood-CSF barrier under inflammatory conditions. Methods In an "inverted" Transwell culture model of the blood-CSF barrier, the zoonotic agent Streptococcus suis (S. suis) was used to stimulate porcine choroid plexus epithelial cells (PCPECs) specifically from the physiologically relevant basolateral side. Barrier function was analyzed by measuring TEER and TR-dextran-flux, and tight junction morphology was investigated by immunofluorescence. Route and mechanism of PMN transmigration were determined by immunofluorescence, electron microscopy and FACS analysis. Quantitative real time-PCR was used to determine expression levels of ICAM-1 and VCAM-1. Results Here, we show that the transmigration of PMNs through PCPECs was significantly higher after stimulation with TNFα or infection with S. suis strain 10 compared to its non-encapsulated mutant. Barrier function was not significantly affected by PMN migration alone, but in combination with S. suis infection. Tight junction and cytoskeletal actin reorganisation were also observed after stimulation with S. suis or TNFα. Most strikingly, PMNs preferentially migrated across PCPECs via the transcellular route. Extensive sequential analyses of the PMN transmigration process with Apotome®-imaging and electron microscopy revealed that paracellular migrating PMNs stop just before tight junctions. Interestingly, PMNs subsequently appeared to proceed by transcellular migration via funnel-like structures developing from the apical membrane. It is noteworthy that some PMNs contained bacteria during the transmigration process. Flow cytometric and

  14. Characterization of Five Zoonotic Streptococcus suis Strains from Germany, Including One Isolate from a Recent Fatal Case of Streptococcal Toxic Shock-Like Syndrome in a Hunter.

    PubMed

    Eisenberg, Tobias; Hudemann, Christoph; Hossain, Hamid M; Hewer, Angela; Tello, Khodr; Bandorski, Dirk; Rohde, Manfred; Valentin-Weigand, Peter; Baums, Christoph Georg

    2015-12-01

    A Streptococcus suis isolate from a German hunter with streptococcal toxic shock-like syndrome (STSLS) and four additional zoonotic isolates were genotyped as mrp(+) epf* (variant 1890) sly(+) cps2(+). All five zoonotic German strains were characterized by high multiplication in human blood samples ex vivo, but induction of only low levels of proinflammatory cytokines compared to a Chinese STSLS strain. PMID:26424844

  15. Investigation into the role of catabolite control protein A in the metabolic regulation of Streptococcus suis serotype 2 using gene expression profile analysis

    PubMed Central

    LANG, XULONG; WAN, ZHONGHAI; PAN, YING; WANG, XIURAN; WANG, XIAOXU; BU, ZHAOYANG; QIAN, JING; ZENG, HUAZONG; WANG, XINGLONG

    2015-01-01

    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. PMID:26170923

  16. Differential activation of the Toll-like receptor 2/6 complex by lipoproteins of Streptococcus suis serotypes 2 and 9.

    PubMed

    Wichgers Schreur, Paul J; Rebel, Johanna M J; Smits, Mari A; van Putten, Jos P M; Smith, Hilde E

    2010-07-14

    Streptococcus suis causes invasive infections in pigs and occasionally in humans. Worldwide, S. suis serotype 2 is most frequently isolated from diseased piglets, but the less virulent serotype 9 is emerging, at least in Europe. We compared the activation of human Toll-like receptors (hTLRs) by S. suis serotype 2 and 9 strains to better understand the role of the innate immune response in fighting S. suis infections. Neither live nor heat-killed log phase grown S. suis activated the hTLR1/2, hTLR2/6 and hTLR4/MD-2 complexes. However, the hTLR2/6 complex was specifically activated by both serotypes after disruption of the cell wall synthesis using penicillin. Activation levels of the hTLR2/6 complex were higher for serotype 9 strains compared to serotype 2 strains suggesting intrinsic differences in cell wall composition between both serotypes. The hTLR2/6 activating fractions decreased in molecular size after digestion with proteinase K and were sensitive for lipoprotein lipase digestion and NaOH hydrolysis, indicating lipoprotein(s) as active component(s). Overall, our results indicate that S. suis lipoproteins activate TLR2/6 but not TLR1/2 and that the clinically different serotypes 2 and 9 display differential release of TLR ligand when cell wall integrity is compromised. PMID:20044219

  17. Impact of an experimental PRRSV and Streptococcus suis coinfection on the pharmacokinetics of ceftiofur hydrochloride after intramuscular injection in pigs.

    PubMed

    Day, D N; Sparks, J W; Karriker, L A; Stalder, K J; Wulf, L W; Zhang, J; Kinyon, J M; Stock, M L; Gehring, R; Wang, C; Ellingson, J; Coetzee, J F

    2015-10-01

    This study determined the impact of porcine reproductive and respiratory syndrome virus (PRRSV) and Streptococcus suis coinfection on the pharmacokinetic (PK) profile of ceftiofur hydrochloride in pigs after intramuscular (i.m.) injection. Eighteen clinically normal crossbred gilts were assigned by weight into a challenge group (10 pigs) and control group (eight pigs). Pigs in both groups received a single i.m. injection of ceftiofur hydrochloride (Excenel RTU Sterile Suspension; Zoetis) at a 5 mg/kg BW dose. Serial blood samples were collected to characterize the plasma concentration curve. After a 10 days drug washout period, the challenge group was inoculated with 2 mL of PRRSV isolate VR-2385 (10(5.75) 50% tissue culture infective doses per mL) intranasally and 8 days later inoculated S. suis. When clinical disease was evident, the second PK assessment began in both challenge and control groups. Coinfected pigs demonstrated lower values of AUC and CMAX , but higher values of Cl/F and Vz/F indicating drug kinetics were altered by infection. The data from this study have implications on ceftiofur treatment regimens in diseased pigs. PMID:25689130

  18. Molecular typing of Streptococcus suis isolates from Iberian pigs: a comparison with isolates from common intensively-reared commercial pig breeds.

    PubMed

    Sánchez Del Rey, V; Fernández-Garayzábal, J F; Bárcena, C; Briones, V; Domínguez, L; Gottschalk, M; Vela, A I

    2014-12-01

    The Iberian pig (IP) is a traditional Spanish breed variety of the domestic pig (Sus scrofa domesticus) with high economic importance because of the value of the dry-cured products in national and international markets. The genetic characteristics of tonsillar and clinical Streptococcus suis isolates from the IP maintained under extensive or intensive management conditions were investigated. S. suis isolates from IP pigs were compared with S. suis isolates from intensively-farmed pigs of common breeds (CBP). S. suis was isolated from 48.4% of the IP tonsils examined, indicating wide distribution among IP pigs. Serotypes 1 (9.4%), 2 (8.6%) and 9 (7%) were the most commonly found, although a high percentage of S. suis isolates were not typeable by coagglutination testing. No significant differences in carrier rates or serotype diversity were observed between management systems, indicating that intensive farming does not influence S. suis colonisation. Both pulsed-field gel electrophoresis and multiple-locus variable number tandem repeat analysis showed a serotype-based distribution of S. suis IP isolates. Serotypes 1 and 2 S. suis isolates were grouped in the same cluster, whereas isolates of serotypes 9 and 7 were assigned to another cluster. All clinical and most tonsillar serotype 2 IP isolates were assigned to sequence type 1 (ST1) and exhibited the virulence genotype mrp+/epf+/sly+, indicating a high distribution of this genetic lineage among IP as well as a population of serotype 2 common to IPs and CBPs. The only clinical isolate of serotype 9 from IP was assigned to ST123, a sequence type associated with clinical isolates in CBPs in Spain. PMID:25458888

  19. Identification and Characterization of IgdE, a Novel IgG-degrading Protease of Streptococcus suis with Unique Specificity for Porcine IgG.

    PubMed

    Spoerry, Christian; Seele, Jana; Valentin-Weigand, Peter; Baums, Christoph G; von Pawel-Rammingen, Ulrich

    2016-04-01

    Streptococcus suisis a major endemic pathogen of pigs causing meningitis, arthritis, and other diseases. ZoonoticS. suisinfections 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 ofS. suisthat exclusively cleaves porcine IgM and represents the first virulence factor described, linkingS. suisto pigs as their natural host. Here we report the identification and characterization of a novel, unrelated protease ofS. suisthat exclusively targets porcine IgG. This enzyme, designated IgdE forimmunoglobulinG-degradingenzyme ofS. 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 allS. suisstrains investigated possess the IgG proteolytic activity and that piglet serum samples contain specific antibodies against IgdE strongly indicate that the protease is expressedin vivoduring infection and represents a novel and putative important bacterial virulence/colonization determinant, and a thus potential therapeutic target. PMID:26861873

  20. Trends in the resistance to antimicrobial agents of Streptococcus suis isolates from Denmark and Sweden.

    PubMed

    Aarestrup, F M; Rasmussen, S R; Artursson, K; Jensen, N E

    1998-08-28

    This study was conducted to determine the MIC values of historical and contemporary Streptoccocus suis (serotypes 2 and 7) from Denmark and S. suis (serotype 2) from Sweden. A total of 52 isolates originating from 1967 through 1981 and 156 isolates from 1992 through 1997 in Denmark and 13 isolates from Sweden were examined for their MICs against 20 different antimicrobial agents. Most antimicrobials were active against most isolates. A frequent occurrence of resistance to sulphamethoxazole was observed, with most resistance among historic isolates of serotype 7 and least resistance among isolates from Sweden. A large number of the isolates was resistant to macrolides. However, all historic serotype 2 isolates from Denmark were susceptible, whereas 20.4% of the contemporary isolates were resistant. Among serotype 7 isolates 23.3% of the historic isolates were resistant to macrolides, whereas resistance was found in 44.8% of the contemporary isolates. All isolates from Sweden were susceptible to macrolides. Time-associated frequency of resistance to tetracycline was also found. Only a single historic isolate of serotype 2 was resistant to tetracycline, whereas 43.9% of the contemporary serotype 2 isolates and 15.5% of the contemporary serotype 7 isolates were resistant. Only one (7.7%) of the isolates from Sweden was resistant. The differences in resistance between historic and contemporary isolates from Denmark were statistically significant. This study demonstrated a significant serotype-associated difference in the susceptibility to macrolides and tetracycline and demonstrated that an increase in resistance among S. suis isolates has taken place during the last 15 years to the two most commonly used antimicrobial agents (tylosin and tetracycline) in pig production in Denmark. PMID:9810623

  1. Pathogenicity of Streptococcus ictaluri to Channel Catfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The infectivity of a Streptococcus ictaluri isolate for fry (0.5 g), fingerling (15 g), and juvenile (55 g) channel catfish (Ictalurus punctatus) was determined by bath immersion and injection infectivity experiments. Channel catfish exposed by immersion were exposed to baths containing 1012, 1011,...

  2. A novel pro-inflammatory protein of Streptococcus suis 2 induces the Toll-like receptor 2-dependent expression of pro-inflammatory cytokines in RAW 264.7 macrophages via activation of ERK1/2 pathway

    PubMed Central

    Zhang, Qiang; Yang, Yujie; Yan, Shuxian; Liu, Jiantao; Xu, Zhongmin; Yu, Junping; Song, Yajing; Zhang, Anding; Jin, Meilin

    2015-01-01

    Streptococcus suis 2 is an important swine pathogen and an emergent zoonotic pathogen. Excessive inflammation caused by S. suis is responsible for the high levels of early mortality observed in septic shock-like syndrome cases. However, the mechanisms through which S. suis 2 (SS2) causes excessive inflammation remain unclear. Thus, this study aimed to identify novel pro-inflammatory mediators that play important roles in the development of therapies against SS2 infection. In this study, the novel pro-inflammatory protein HP0459, which was encoded by the SSUSC84_0459 gene, was discovered. The stimulation of RAW 264.7 macrophages with recombinant HP0459 protein induced the expression of pro-inflammatory cytokines (IL-1β, MCP-1 and TNF-α). Compared with the wild-type (WT) strain, the isogenic knockout of HP0459 in SS2 led to reduced production of pro-inflammatory cytokines in RAW264.7 macrophages and in vivo. The pro-inflammatory activity of HP0459 was significantly reduced by an antibody against Toll-like receptor 2 (TLR2) in RAW264.7 macrophages and was lower in TLR2-deficient (TLR2-/-) macrophages than in WT macrophages. Furthermore, specific inhibitors of the extracellular signal-regulated kinase 1/2 (ERK1/2) pathways significantly decreased the HP0459-induced pro-inflammatory cytokine production, and a western blot assay showed that HP0459 stimulation induced the activation of the ERK1/2 pathway. Taken together, our data indicate that HP0459 is a novel pro-inflammatory mediator of SS2 and induces TLR2-dependent pro-inflammatory activity in RAW264.7 macrophages through the ERK1/2 pathway. PMID:25806027

  3. CD14-dependent and -independent cytokine and chemokine production by human THP-1 monocytes stimulated by Streptococcus suis capsular type 2

    PubMed Central

    SEGURA, M; VADEBONCOEUR, N; GOTTSCHALK, M

    2002-01-01

    Streptococcus suis capsular type 2 is an important aetiologic agent of swine meningitis, and it has been highlighted as a cause of occupational disease leading to meningitis and fulminant sepsis in humans. The objective of the present work was to study the ability of S. suis type 2 to induce the release of tumour necrosis factor alpha (TNF-α), interleukin-1 (IL-1), IL-6, IL-8 and monocyte chemotactic protein one (MCP-1) by human monocytic THP-1 cells. The induction of these five cytokines was dose- and incubation time-dependent, and it was significantly enhanced by pre-treatment of cells with interferon gamma. IL-8 levels were markedly higher compared with those obtained with the other cytokines. However, elevated levels of MCP-1 and IL-6 were also observed. Levels of cytokine induced by heat-killed or live bacteria were similar. Pre-treatment of cells with anti-CD14 monoclonal antibodies suggested that this important host receptor is partially implicated in TNF, IL-1, IL-6 andMCP-1 production, while CD14-independent pathways seem to be responsible for IL-8 production after S. suis stimulation. In addition, blocking studies with anti-TNF and anti-IL-1 antibodies revealed that these cytokines are involved in amplification of the S. suis-induced cytokine cascade. When several different S. suis strains of human or porcine origin were compared, a very heterogeneous pattern of cytokine production was observed. Human strains did not exhibit a clear tendency to induce higher cytokine release by human THP-1 monocytes. The synergistic effect of the up-regulation of cytokines during S. suis meningitis may mediate many of the inflammatory reactions, including the sequestration of leucocytes at the site of infection. PMID:11876746

  4. Enolase of Streptococcus Suis Serotype 2 Enhances Blood-Brain Barrier Permeability by Inducing IL-8 Release.

    PubMed

    Sun, Yingying; Li, Na; Zhang, Jing; Liu, Hongtao; Liu, Jianfang; Xia, Xiaojing; Sun, Changjiang; Feng, Xin; Gu, Jingmin; Du, Chongtao; Han, Wenyu; Lei, Liancheng

    2016-04-01

    Streptococcus suis serotype 2 (SS2) is an emerging zoonosis, and meningitis is the most frequent clinical manifestation, but mechanism of its virulent factor, enolase (Eno), is unknown in meningitis. In this study, Eno was inducibly expressed and added to an in vitro Transwell co-culture model of the blood-brain barrier (BBB) consisted of porcine brain microvascular endothelial cells (PBMECs) and astrocytes (ACs), the results showed that Eno induces a significant increase in BBB permeability and promotes the release of IL-8 et al. cytokines. Furthermore, IL-8 could significantly destroy the integrity of the BBB model in vitro. In mice models administered Eno for 24 h, Eno could significantly promote Evans blue (EB) moving from the blood to the brain and significantly increased the serum and brain levels of IL-8, as detected by ELISA. While G31P (IL-8 receptor antagonist) significantly decreased the concentration of EB in the brains of mice injected with Eno. The present study demonstrated that SS2 Eno may play an important role in disrupting BBB integrity by prompting IL-8 release. PMID:26732390

  5. Gross and histopathological findings in unusual lesions caused by Streptococcus suis in pigs. II. Central nervous system lesions.

    PubMed Central

    Sanford, S E

    1987-01-01

    Subacute meningoencephalitis or meningoencephalomyelitis caused by Streptococcus suis was diagnosed in 53 pigs over a four-year period. Affected pigs averaging 11 weeks of age with a range from five days to 26 weeks, had been treated with antibiotics and had partially recovered. Hyperemia of meningeal vessels and modest increase in cerebrospinal fluid were the most common gross central nervous system lesions. Histologically, fibrin, edema and a mixture of inflammatory cells were present in meninges and choroid plexus. Linear and perivascular infiltrates of neutrophils and mononuclear inflammatory cells invaded the brain and spinal cord and similar infiltrates were in lumina of ventricles and the spinal canal. Inflammatory cells also invaded the superficial layers of the brain directly from the overlying meninges. Bilateral subacute optic perineuritis and Gasserian ganglioneuritis also occurred. Segmental cortical necrosis of cerebellar folia characterized by degeneration, necrosis, neuronophagia and drop out of groups of Purkinje cells was a distinct lesion seen in 27 of the 53 pigs. Mild spongiosis of white matter in the cerebellum and brain stem accompanied these changes. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. PMID:3453269

  6. Identification of Novel Laminin- and Fibronectin-binding Proteins by Far-Western Blot: Capturing the Adhesins of Streptococcus suis Type 2

    PubMed Central

    Li, Quan; Liu, Hanze; Du, Dechao; Yu, Yanfei; Ma, Caifeng; Jiao, Fangfang; Yao, Huochun; Lu, Chengping; Zhang, Wei

    2015-01-01

    Bacterial cell wall (CW) and extracellular (EC) proteins are often involved in interactions with extracellular matrix (ECM) proteins such as laminin (LN) and fibronectin (FN), which play important roles in adhesion and invasion. In this study, an efficient method combining proteomic analysis and Far-Western blotting assays was developed to screen directly for bacterial surface proteins with LN- and FN-binding capacity. With this approach, fifteen potential LN-binding proteins and five potential FN-binding proteins were identified from Streptococcus suis serotype 2 (SS2) CW and EC proteins. Nine newly identified proteins, including oligopeptide-binding protein OppA precursor (OppA), elongation factor Tu (EF-Tu), enolase, lactate dehydrogenase (LDH), fructose-bisphosphate aldolase (FBA), 3-ketoacyl-ACP reductase (KAR), Gly ceraldehyde-3-phosphate dehydrogenase (GAPDH), Inosine 5′-monophosphate dehydrogenase (IMPDH), and amino acid ABC transporter permease (ABC) were cloned, expressed, purified and further confirmed by Far-Western blotting and ELISA. Five proteins (OppA, EF-Tu, enolase, LDH, and FBA) exhibited specifically binding activity to both human LN and human FN. Furthermore, seven important recombinant proteins were selected and identified to have the ability to bind Hep-2 cells by the indirect immunofluorescent assay. In addition, four recombinant proteins, and their corresponding polyclonal antibodies, were observed to decrease SS2 adhesion to Hep-2 cells, which indicates that these proteins contribute to the adherence of SS2 to host cell surface. Collectively, these results show that the approach described here represents a useful tool for investigating the host-pathogen interactions. PMID:26636044

  7. Investigation of Pathogenesis of H1N1 Influenza Virus and Swine Streptococcus suis Serotype 2 Co-Infection in Pigs by Microarray Analysis.

    PubMed

    Lin, Xian; Huang, Canhui; Shi, Jian; Wang, Ruifang; Sun, Xin; Liu, Xiaokun; Zhao, Lianzhong; Jin, Meilin

    2015-01-01

    Swine influenza virus and Streptococcus suis are two important contributors to the porcine respiratory disease complex, and both have significant economic impacts. Clinically, influenza virus and Streptococcus suis co-infections in pigs are very common, which often contribute to severe pneumonia and can increase the mortality. However, the co-infection pathogenesis in pigs is unclear. In the present study, co-infection experiments were performed using swine H1N1 influenza virus and Streptococcus suis serotype 2 (SS2). The H1N1-SS2 co-infected pigs exhibited more severe clinical symptoms, serious pathological changes, and robust apoptosis of lungs at 6 days post-infection compared with separate H1N1 and SS2 infections. A comprehensive gene expression profiling using a microarray approach was performed to investigate the global host responses of swine lungs against the swine H1N1 infection, SS2 infection, co-infection, and phosphate-buffered saline control. Results showed 457, 411, and 844 differentially expressed genes in the H1N1, SS2, and H1N1-SS2 groups, respectively, compared with the control. Noticeably, genes associated with the immune, inflammatory, and apoptosis responses were highly overexpressed in the co-infected group. Pathway analysis indicated that the cytokine-cytokine receptor interactions, MAPK, toll-like receptor, complement and coagulation cascades, antigen processing and presentation, and apoptosis pathway were significantly regulated in the co-infected group. However, the genes related to these were less regulated in the separate H1N1 and SS2 infection groups. This observation suggested that a certain level of synergy was induced by H1N1 and SS2 co-infection with significantly stronger inflammatory and apoptosis responses, which may lead to more serious respiratory disease syndrome and pulmonary pathological lesion. PMID:25906258

  8. Ecology and pathogenicity of gastrointestinal Streptococcus bovis.

    PubMed

    Herrera, Paul; Kwon, Young Min; Ricke, Steven C

    2009-01-01

    Streptococcus bovis is an indigenous resident in the gastrointestinal tracts of both humans and animals. S. bovis is one of the major causes of bacterial endocarditis and has been implicated in the incidence of human colon cancer, possibly due to chronic inflammatory response at the site of intestinal colonization. Certain feeding regimens in ruminants can lead to overgrowth of S. bovis in the rumen, resulting in the over-production of lactate and capsular polysaccharide causing acute ruminal acidosis and bloat, respectively. There are multiple strategies in controlling acute lactic acidosis and bloat. The incidence of the two diseases may be controlled by strict dietary management. Gradual introduction of grain-based diets and the feeding of coarsely chopped roughage decrease the incidence of the two disease entities. Ionophores, which have been used to enhance feed conversion and growth rate in cattle, have been shown to inhibit the growth of lactic acid bacteria in the rumen. Other methods of controlling lactic acid bacteria in the ruminal environment (dietary supplementation of long-chain fatty acids, induction of passive and active immune responses to the bacteria, and the use of lytic bacteriophages) have also been investigated. It is anticipated that through continued in-depth ecological analysis of S. bovis the characteristics responsible for human and animal pathogenesis would be sufficiently identified to a point where more effective control strategies for the control of this bacteria can be developed. PMID:19100852

  9. The roles of RelA/(p)ppGpp in glucose-starvation induced adaptive response in the zoonotic Streptococcus suis

    PubMed Central

    Zhang, Tengfei; Zhu, Jiawen; Wei, Shun; Luo, Qingping; Li, Lu; Li, Shengqing; Tucker, Alexander; Shao, Huabin; Zhou, Rui

    2016-01-01

    The (p)ppGpp signal molecules play a central role in the stringent response (SR) to adapt to nutrient starvation in bacteria, yet the carbohydrate starvation induced adaptive response and the roles of SR in this response is not well characterized, especially in Gram-positives. Here, two (p)ppGpp synthetases RelA and RelQ are identified in Streptococcus suis, an important emerging zoonotic Gram-positive bacterium, while only RelA is functional under glucose starvation. To characterize the roles of RelA/(p)ppGpp in glucose starvation response in S. suis, the growth curves and transcriptional profiles were compared between the mutant strain ΔrelA [a (p)ppGpp0 strain under glucose starvation] and its parental strain SC-19 [(p)ppGpp+]. The results showed great difference between SC-19 and ΔrelA on adaptive responses when suffering glucose starvation, and demonstrated that RelA/(p)ppGpp plays important roles in adaptation to glucose starvation. Besides the classic SR including inhibition of growth and related macromolecular synthesis, the extended adaptive response also includes inhibited glycolysis, and carbon catabolite repression (CCR)-mediated carbohydrate-dependent metabolic switches. Collectively, the pheno- and genotypic characterization of the glucose starvation induced adaptive response in S. suis makes a great contribution to understanding better the mechanism of SR. PMID:27255540

  10. Characterization of the immune response and evaluation of the protective capacity of rSsnA against Streptococcus suis infection in pigs.

    PubMed

    Gómez-Gascón, Lidia; Cardoso-Toset, Fernando; Tarradas, Carmen; Gómez-Laguna, Jaime; Maldonado, Alfonso; Nielsen, Jens; Olaya-Abril, Alfonso; Rodríguez-Ortega, Manuel J; Luque, Inmaculada

    2016-08-01

    The efforts made to develop vaccines against Streptococcus suis have failed because of lack of common antigens cross-reactive against different serotypes of this species. The cell wall-anchored proteins can be good vaccine candidates due to their high expression and accessibility to antibodies, among these, a cell-wall protein, DNA-nuclease (SsnA), present in most of the S. suis serotypes and clinical isolates collected from infected pigs, was selected. An experimental challenge against S. suis serotype 2 in a pig model was used to validate the efficacy of recombinant SsnA combined with aluminium hydroxide plus Quil A as adjuvants, previously tested in mice by our research group with good results. In our study, clinical characteristics, bacterial load and spread, haematological and immunological parameters and the antibody response, including the opsonophagocytosis analysis of the sera were evaluated. Moreover the composition of peripheral blood leukocyte populations was studied in infected animals. The results show that the immunization of piglets with rSsnA elicits a significant humoral antibody response. However, the antibody response is not reflected in protection of pigs that are challenged with a virulent strain in our conventional vaccination model. Further studies are necessary to evaluate the use of rSsnA as a vaccine candidate for swine. PMID:27477507

  11. The roles of RelA/(p)ppGpp in glucose-starvation induced adaptive response in the zoonotic Streptococcus suis.

    PubMed

    Zhang, Tengfei; Zhu, Jiawen; Wei, Shun; Luo, Qingping; Li, Lu; Li, Shengqing; Tucker, Alexander; Shao, Huabin; Zhou, Rui

    2016-01-01

    The (p)ppGpp signal molecules play a central role in the stringent response (SR) to adapt to nutrient starvation in bacteria, yet the carbohydrate starvation induced adaptive response and the roles of SR in this response is not well characterized, especially in Gram-positives. Here, two (p)ppGpp synthetases RelA and RelQ are identified in Streptococcus suis, an important emerging zoonotic Gram-positive bacterium, while only RelA is functional under glucose starvation. To characterize the roles of RelA/(p)ppGpp in glucose starvation response in S. suis, the growth curves and transcriptional profiles were compared between the mutant strain ΔrelA [a (p)ppGpp(0) strain under glucose starvation] and its parental strain SC-19 [(p)ppGpp(+)]. The results showed great difference between SC-19 and ΔrelA on adaptive responses when suffering glucose starvation, and demonstrated that RelA/(p)ppGpp plays important roles in adaptation to glucose starvation. Besides the classic SR including inhibition of growth and related macromolecular synthesis, the extended adaptive response also includes inhibited glycolysis, and carbon catabolite repression (CCR)-mediated carbohydrate-dependent metabolic switches. Collectively, the pheno- and genotypic characterization of the glucose starvation induced adaptive response in S. suis makes a great contribution to understanding better the mechanism of SR. PMID:27255540

  12. Genomic comparison between pathogenic Streptococcus agalactiae isolated from Nile tilapia in Thailand and fish-derived ST7 strains.

    PubMed

    Kayansamruaj, Pattanapon; Pirarat, Nopadon; Kondo, Hidehiro; Hirono, Ikuo; Rodkhum, Channarong

    2015-12-01

    Streptococcus agalactiae, or Group B streptococcus (GBS), is a highly virulent pathogen in aquatic animals, causing huge mortalities worldwide. In Thailand, the serotype Ia, β-hemolytic GBS, belonging to sequence type (ST) 7 of clonal complex (CC) 7, was found to be the major cause of streptococcosis outbreaks in fish farms. In this study, we performed an in silico genomic comparison, aiming to investigate the phylogenetic relationship between the pathogenic fish strains of Thai ST7 and other ST7 from different hosts and geographical origins. In general, the genomes of Thai ST7 strains are closely related to other fish ST7s, as the core genome is shared by 92-95% of any individual fish ST7 genome. Among the fish ST7 genomes, we observed only small dissimilarities, based on the analysis of clustered regularly interspaced short palindromic repeats (CRISPRs), surface protein markers, insertions sequence (IS) elements and putative virulence genes. The phylogenetic tree based on single nucleotide polymorphisms (SNPs) of the core genome sequences clearly categorized the ST7 strains according to their geographical and host origins, with the human ST7 being genetically distant from other fish ST7 strains. A pan-genome analysis of ST7 strains detected a 48-kb gene island specifically in the Thai ST7 isolates. The orientations and predicted amino acid sequences of the genes in the island closely matched those of Tn5252, a streptococcal conjugative transposon, in GBS 2603V/R serotype V, Streptococcus pneumoniae and Streptococcus suis. Thus, it was presumed that Thai ST7 acquired this Tn5252 homologue from related streptococci. The close phylogenetic relationship between the fish ST7 strains suggests that these strains were derived from a common ancestor and have diverged in different geographical regions and in different hosts. PMID:26455417

  13. First insights into the protective effects of a recombinant swinepox virus expressing truncated MRP of Streptococcus suis type 2 in mice.

    PubMed

    Huang, Dongyan; Zhu, Haodan; Lin, Huixing; Xu, Jiarong; Lu, Chengping

    2012-01-01

    To explore the potential of the swinepox virus (SPV) as vector for Streptococcus suis vaccines, a vector system was developed for the construction of a recombinant SPV carrying bacterial genes. Using this system, a recombinant virus expressing truncated muramidase-released protein (MRP) of S. suis type 2 (SS2), designated rSPV-MRP, was produced and identified by PCR, western blotting and immunofluorescence assays. The rSPV-MRP was found to be only slightly attenuated in PK-15 cells, when compared with the wild-type virus. After immunization intramuscularly with rSPV-MRP, SS2 inactive vaccine (positive control), wild-type SPV (negative control) and PBS (blank control) respectively, all CD1 mice were challenged with a lethal dose or a sublethal dose of SS2 highly virulent strain ZY05719. While SS2 inactive vaccine protected all mice, immunization with rSPV-MRP resulted in 60% survival and protected mice against a lethal dose of the highly virulent SS2 strain, compared with the negative control (P < 0.05). Our data indicate that animals immunized with rSPV-MRP had a significantly reduced bacterial burden in all organs examined, compared to negative controls and blank controls (P <0.05). Antibody titers of the rSPV-MRP-vaccinated group were significantly higher (P <0.001), when compared to negative controls and blank controls. Antibody titers were also significantly higher in the vaccinated group at all time points post-vaccination (P <0.001), compared with the positive controls. These initial results demonstrated that the rSPV-MRP provided mice with protection from systemic SS2 infection. If SPV recombinants have the potential as S. suis vaccines for the use in pigs has to be evaluated in further studies. PMID:22515033

  14. Prevalence and pathogenicity of Cryptosporidium suis in pre- and post-weaned pigs.

    PubMed

    Vítovec, J; Hamadejová, K; Landová, L; Kvác, M; Kvetonová, D; Sak, B

    2006-06-01

    A total of 4338 faecal samples, 135 of sows, 3368 of pre-weaned and 835 of post-weaned piglets from eight farms in South Bohemia, Czech Republic were collected and examined for Cryptosporidium infection. No sow, but 5.7% pre-weaned and 24.1% post-weaned piglets were positive for Cryptosporidium infection. No relationship was found between diarrhoea and Cryptosporidium infection in any of the different age groups (pre- and post-weaned piglets). Four piglets, which were sporadically shedding cryptosporidia in faeces, were necropsied. Neither clinical signs of diarrhoea nor macroscopical changes were found. Histologically, a moderate infection of cryptosporidia was detected in the glandular epithelium along the large intestine, with predisposition to the ansa centralis of the colon. No inflammatory response in the lamina propria was observed. Cryptosporidia were also commonly found in the glandular epithelium of submucosal lymphoglandular complexes in the colon. Cryptosporidium isolates from all farms were identified as Cryptosporidium suis using molecular markers (SSU rRNA). All of the C. suis strains obtained were larger [6.2 (6.0-6.8) x 5.5 (5.3-5.7) microm] than any isolate described so far [4.6 (4.4-4.9) x 4.2 (4.0-4.3) microm] and did not appear to be infective for neonatal BALB/c mice. PMID:16732883

  15. Epidemiology and pathogenicity of zoonotic streptococci.

    PubMed

    Fulde, Marcus; Valentin-Weigand, Peter

    2013-01-01

    Zoonotic infections caused by Streptococcus spp. have been neglected in spite of the fact that frequency and severity of outbreaks increased dramatically in recent years. This may be due to non-identification since respective species are often not considered in human medical diagnostic procedures. On the other hand, an expanding human population concomitant with an increasing demand for food and the increased number of companion animals favour conditions for host species adaptation of animal streptococci. This review aims to give an overview on streptococcal zoonoses with focus on epidemiology and pathogenicity of four major zoonotic species, Streptococcus canis, Streptococcus equi sub. zooepidemicus, Streptococcus iniae and Streptococcus suis. PMID:23192319

  16. Antioxidant Activity and Antibacterial Effects on Clinical Isolated Streptococcus suis and Staphylococcus intermedius of Extracts from Several Parts of Cladogynos orientalis and Their Phytochemical Screenings

    PubMed Central

    Sithisarn, Pongtip; Rojsanga, Piyanuch; Sithisarn, Patchima; Kongkiatpaiboon, Sumet

    2015-01-01

    The in vitro antioxidant and antibacterial assays against clinically isolated Streptococcus suis and Staphylococcus intermedius of the extracts prepared by decoction and ethanolic reflux of different parts of Chettaphangki (Cladogynos orientalis Zipp. ex Span), including the leaves, roots, and stems, using 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging assay and disc diffusion method were conducted. Quantitative analysis of total phenolic and total flavonoid contents in the extracts using spectrophotometric methods was also performed. Finally, phytochemical screening by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) was conducted. Leaf ethanolic reflux extract (100 g) contained the highest total phenolic and total flavonoid contents of 7.21 ± 0.28 μg gallic acid equivalent (GAE) and 11.51 ± 2.02 μg rutin equivalent (RE), respectively. Chettaphangki extracts promoted low antioxidant activity with EC50 values in the range of 0.27–0.48 mg/mL. Extracts and fractions from the roots and stems of this plant promoted low to intermediate antibacterial activity against S. intermedius with the inhibition zones between 7 and 14 mm. The chromatographic data suggested that the leaf extracts of C. orientalis contained rutin while the root and stem extracts contained scopoletin and chettaphanin I. Rutin promoted strong antioxidant activity while chettaphanin I showed low antibacterial activity against Staphylococcus intermedius. PMID:26347795

  17. Tetracycline Selective Pressure and Homologous Recombination Shape the Evolution of Chlamydia suis: A Recently Identified Zoonotic Pathogen.

    PubMed

    Joseph, Sandeep J; Marti, Hanna; Didelot, Xavier; Read, Timothy D; Dean, Deborah

    2016-01-01

    Species closely related to the human pathogen Chlamydia trachomatis (Ct) have recently been found to cause zoonotic infections, posing a public health threat especially in the case of tetracycline resistant Chlamydia suis (Cs) strains. These strains acquired a tet(C)-containing cassette via horizontal gene transfer (HGT). Genomes of 11 Cs strains from various tissues were sequenced to reconstruct evolutionary pathway(s) for tet(C) HGT. Cs had the highest recombination rate of Chlamydia species studied to date. Admixture occurred among Cs strains and with Chlamydia muridarum but not with Ct Although in vitro tet(C) cassette exchange with Ct has been documented, in vivo evidence may require examining human samples from Ct and Cs co-infected sites. Molecular-clock dating indicated that ancestral clades of resistant Cs strains predated the 1947 discovery of tetracycline, which was subsequently used in animal feed. The cassette likely spread throughout Cs strains by homologous recombination after acquisition from an external source, and our analysis suggests Betaproteobacteria as the origin. Selective pressure from tetracycline may be responsible for recent bottlenecks in Cs populations. Since tetracycline is an important antibiotic for treating Ct, zoonotic infections at mutual sites of infection indicate the possibility for cassette transfer and major public health repercussions. PMID:27576537

  18. Tetracycline Selective Pressure and Homologous Recombination Shape the Evolution of Chlamydia suis: A Recently Identified Zoonotic Pathogen

    PubMed Central

    Joseph, Sandeep J.; Marti, Hanna; Didelot, Xavier; Read, Timothy D.; Dean, Deborah

    2016-01-01

    Species closely related to the human pathogen Chlamydia trachomatis (Ct) have recently been found to cause zoonotic infections, posing a public health threat especially in the case of tetracycline resistant Chlamydia suis (Cs) strains. These strains acquired a tet(C)-containing cassette via horizontal gene transfer (HGT). Genomes of 11 Cs strains from various tissues were sequenced to reconstruct evolutionary pathway(s) for tet(C) HGT. Cs had the highest recombination rate of Chlamydia species studied to date. Admixture occurred among Cs strains and with Chlamydia muridarum but not with Ct. Although in vitro tet(C) cassette exchange with Ct has been documented, in vivo evidence may require examining human samples from Ct and Cs co-infected sites. Molecular-clock dating indicated that ancestral clades of resistant Cs strains predated the 1947 discovery of tetracycline, which was subsequently used in animal feed. The cassette likely spread throughout Cs strains by homologous recombination after acquisition from an external source, and our analysis suggests Betaproteobacteria as the origin. Selective pressure from tetracycline may be responsible for recent bottlenecks in Cs populations. Since tetracycline is an important antibiotic for treating Ct, zoonotic infections at mutual sites of infection indicate the possibility for cassette transfer and major public health repercussions. PMID:27576537

  19. Draft genome sequence of a nonhemolytic fish-pathogenic Streptococcus agalactiae strain.

    PubMed

    Delannoy, Christian M J; Zadoks, Ruth N; Lainson, Frederick A; Ferguson, Hugh W; Crumlish, Margaret; Turnbull, James F; Fontaine, Michael C

    2012-11-01

    Streptococcus agalactiae is a significant Gram-positive bacterial pathogen of terrestrial and aquatic animals. A subpopulation of nonhemolytic strains which appear to be pathogenic only for poikilotherms exists. We report here the first draft genome sequence of a nonhemolytic S. agalactiae isolate recovered from a diseased fish. PMID:23105075

  20. Differential pathogenicity of five Streptococcus agalactiae isolates of diverse geographic origin in Nile tilapia (Oreochromis niloticus L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus agalactiae is an emerging pathogen of fish and has caused significant morbidity amd mortality worldwide. The work in this study assessed whether pathogenic differences exist among isolates from different geographic locations. Nile tilapia (Oreochromis niloticus L.) were administered an...

  1. Identification of the Novel Lincosamide Resistance Gene lnu(E) Truncated by ISEnfa5-cfr-ISEnfa5 Insertion in Streptococcus suis: De Novo Synthesis and Confirmation of Functional Activity in Staphylococcus aureus

    PubMed Central

    Zhao, Qin; Wendlandt, Sarah; Li, Hui; Li, Jun; Wu, Congming; Shen, Jianzhong

    2014-01-01

    The novel lincosamide resistance gene lnu(E), truncated by insertion of an ISEnfa5-cfr-ISEnfa5 segment, was identified in Streptococcus suis. The gene lnu(E) encodes a 173-amino-acid protein with ≤69.4% identity to other lincosamide nucleotidyltransferases. The lnu(E) gene and its promoter region were de novo synthesized, and Staphylococcus aureus RN4220 carrying a shuttle vector with the cloned lnu(E) gene showed a 16-fold increase in the lincomycin MIC. Mass spectrometry experiments demonstrated that Lnu(E) catalyzed the nucleotidylation of lincomycin. PMID:24366733

  2. Superoxide dismutase of Streptococcus suis serotype 2 plays a role in anti-autophagic response by scavenging reactive oxygen species in infected macrophages.

    PubMed

    Fang, Lihua; Shen, Hongxia; Tang, Yulong; Fang, Weihuan

    2015-04-17

    Streptococcus suis serotype 2 (SS2) causes septic shock and meningitis. However, its pathogenesis is still not well-understood. We have recently shown that superoxide dismutase sodA of SS2 is a virulence factor probably by increasing resistance to oxidative stresses. Reactive oxygen species (ROS) are products of the respiratory burst of phagocytic cells and have been shown to activate autophagy. We wanted to know if and how SS2 explores its sodA to interfere with cell autophagic responses. A sodA deletion mutant (Δsod) was compared with its parent and complemented strain in autophagic response in the murine macrophage cell line RAW264.7. We found that the Δsod mutant induced significant autophagic responses in infected cells, shown as increased LC3 lipidation (LC3-II) and EGFP-LC3 punctae, than those infected by its parent or complemented strain at 1 or 2h post-infection. Co-localization of the autophagosomal EGFP-LC3 vesicles with lysosomes was seen in cells infected with Δsod mutant and its parent strain, indicating that SS2 infection induced complete autophagic responses. Reduced autophagic responses of cells infected with the wild-type strain might be related to decreased ROS by the scavenging effect of its sodA, as shown by increased superoxide anion or ROS level in cells infected with the Δsod mutant and in the cell free xanthine oxidase-hypoxanthine ROS-generating system, as compared with its parent or complemented strain. Taken together, SS2 makes use of its sodA for survival not only by scavenging ROS but also by alleviating the host autophagic responses due to ROS stimulation. PMID:25726301

  3. An ultrasensitive peroxydisulfate electrochemiluminescence immunosensor for Streptococcus suis serotype 2 based on L-cysteine combined with mimicking bi-enzyme synergetic catalysis to in situ generate coreactant.

    PubMed

    Wang, Haijun; Yuan, Ruo; Chai, Yaqin; Cao, Yaling; Gan, Xianxue; Chen, Yinfeng; Wang, Yan

    2013-05-15

    A novel signal amplification strategy of mimicking bi-enzyme synergetic catalysis to generate coreactant in situ was designed to fabricate an ultrasensitive peroxydisulfate electrochemiluminescence (ECL) immunosensor for detection of Streptococcus suis serotype 2 (SS2). It was the first time to detect SS2 by using ECL. Through the interaction between l-cysteine (l-cys) and hollow PtPd bimetal alloy nanoparticles (HPtPd) to form ((l-cys-HPtPd)n) nanocomposites, the loading amount of l-cys and HPtPd was greatly increased, which could greatly enhance the ECL signal of peroxydisulfate. At the same time, Glucose Oxidase (GOD), used to block nonspecific binding sites of (l-cys-HPtPd)n nanocomposites, could rapidly oxidize d-glucose in the detection solution into gluconic acid accompanying with the generation of H2O2, which was further catalyzed by HPtPd to generate O2. And O2, acted as the coreactant of peroxydisulfate, could greatly amplify the ECL signal. In the process, HPtPd could be regarded as mimicking enzyme, the effect of which was similar to horseradish peroxidase (HRP) in generating O2. With the several amplification factors of a sandwich-type structure we designed, a wide linear ranged from 0.0001 to 100ngmL(-1) was acquired with a relatively low detection limit of 33fgmL(-1) for SS2. The present work demonstrated that the novel strategy had the great advantages in sensitivity, selectivity and reproducibility which might hold a new promise for highly sensitive bioassays applied in clinical detection. PMID:23277341

  4. Streptococcus parasanguinis: new pathogen associated with asymptomatic mastitis in sheep.

    PubMed Central

    Fernández-Garayzábal, J. F.; Fernández, E.; Las Heras, A.; Pascual, C.; Collins, M. D.; Domínguez, L.

    1998-01-01

    We describe two unusual cases in sheep of subclinical mastitis caused by Streptococcus parasanguinis. This bacterium has been associated with the development of experimental endocarditis; its presence at relatively high concentrations in apparently healthy sheep milk may pose a health risk in persons with predisposing heart lesions. PMID:9866743

  5. Misidentification of Streptococcus uberis as a human pathogen: a case report and literature review.

    PubMed

    Di Domenico, Enea Gino; Toma, Luigi; Prignano, Grazia; Pelagalli, Lorella; Police, Andrea; Cavallotti, Claudia; Torelli, Riccardo; Sanguinetti, Maurizio; Ensoli, Fabrizio

    2015-04-01

    Streptococcus uberis is an environmental bacterium responsible for bovine mastitis. It is occasionally described as a human pathogen, though in most cases the identification was based on biochemical phenotyping techniques. This report shows that the biochemical phenotyping may incorrectly identify Enterococcus faecium as S. uberis. PMID:25578263

  6. Streptococcus iniae and Streptococcus agalactiae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus iniae and S. agalactiae are economically important Gram positive bacterial pathogens of cultured and wild fish with a worldwide distribution. Both bacteria are potential zoonotic pathogens and have been associated most often with infections in immunocompromised people. Streptococcus in...

  7. Disease Manifestations and Pathogenic Mechanisms of Group A Streptococcus

    PubMed Central

    Barnett, Timothy C.; McArthur, Jason D.; Cole, Jason N.; Gillen, Christine M.; Henningham, Anna; Sriprakash, K. S.; Sanderson-Smith, Martina L.; Nizet, Victor

    2014-01-01

    SUMMARY Streptococcus pyogenes, also known as group A Streptococcus (GAS), causes mild human infections such as pharyngitis and impetigo and serious infections such as necrotizing fasciitis and streptococcal toxic shock syndrome. Furthermore, repeated GAS infections may trigger autoimmune diseases, including acute poststreptococcal glomerulonephritis, acute rheumatic fever, and rheumatic heart disease. Combined, these diseases account for over half a million deaths per year globally. Genomic and molecular analyses have now characterized a large number of GAS virulence determinants, many of which exhibit overlap and redundancy in the processes of adhesion and colonization, innate immune resistance, and the capacity to facilitate tissue barrier degradation and spread within the human host. This improved understanding of the contribution of individual virulence determinants to the disease process has led to the formulation of models of GAS disease progression, which may lead to better treatment and intervention strategies. While GAS remains sensitive to all penicillins and cephalosporins, rising resistance to other antibiotics used in disease treatment is an increasing worldwide concern. Several GAS vaccine formulations that elicit protective immunity in animal models have shown promise in nonhuman primate and early-stage human trials. The development of a safe and efficacious commercial human vaccine for the prophylaxis of GAS disease remains a high priority. PMID:24696436

  8. Disease manifestations and pathogenic mechanisms of Group A Streptococcus.

    PubMed

    Walker, Mark J; Barnett, Timothy C; McArthur, Jason D; Cole, Jason N; Gillen, Christine M; Henningham, Anna; Sriprakash, K S; Sanderson-Smith, Martina L; Nizet, Victor

    2014-04-01

    Streptococcus pyogenes, also known as group A Streptococcus (GAS), causes mild human infections such as pharyngitis and impetigo and serious infections such as necrotizing fasciitis and streptococcal toxic shock syndrome. Furthermore, repeated GAS infections may trigger autoimmune diseases, including acute poststreptococcal glomerulonephritis, acute rheumatic fever, and rheumatic heart disease. Combined, these diseases account for over half a million deaths per year globally. Genomic and molecular analyses have now characterized a large number of GAS virulence determinants, many of which exhibit overlap and redundancy in the processes of adhesion and colonization, innate immune resistance, and the capacity to facilitate tissue barrier degradation and spread within the human host. This improved understanding of the contribution of individual virulence determinants to the disease process has led to the formulation of models of GAS disease progression, which may lead to better treatment and intervention strategies. While GAS remains sensitive to all penicillins and cephalosporins, rising resistance to other antibiotics used in disease treatment is an increasing worldwide concern. Several GAS vaccine formulations that elicit protective immunity in animal models have shown promise in nonhuman primate and early-stage human trials. The development of a safe and efficacious commercial human vaccine for the prophylaxis of GAS disease remains a high priority. PMID:24696436

  9. The usefulness of biotyping in the determination of selected pathogenicity determinants in Streptococcus mutans

    PubMed Central

    2014-01-01

    Background Streptococcus mutans is known to be a primary etiological factor of dental caries, a widespread and growing disease in Polish children. Recognition of novel features determining the pathogenicity of this pathogen may contribute to understanding the mechanisms of bacterial infections. The goal of the study was to determine the activity of prephenate dehydrogenase (PHD) and to illuminate the role of the enzyme in S. mutans pathogenicity. The strains were biotyped based on STREPTOtest 24 biochemical identification tests and the usefulness of biotyping in the determination of S. mutans pathogenicity determinants was examined. Results Out of ninety strains isolated from children with deciduous teeth fifty three were classified as S. mutans species. PDH activity was higher (21.69 U/mg on average) in the experimental group compared to the control group (5.74 U/mg on average) (P <0.001). Moreover, it was demonstrated that biotype I, established basing on the biochemical characterization of the strain, was predominant (58.5%) in oral cavity streptococcosis. Its dominance was determined by higher PDH activity compared to biotypes II and III (P = 0.0019). Conclusions The usefulness of biotyping in the determination of Streptococcus mutans pathogenicity determinants was demonstrated. The obtained results allow for better differentiation of S. mutans species and thus may contribute to recognition of pathogenic bacteria transmission mechanisms and facilitate treatment. PMID:25096795

  10. Genome characterization and population genetic structure of the zoonotic pathogen, Streptococcus canis

    PubMed Central

    2012-01-01

    Background Streptococcus canis is an important opportunistic pathogen of dogs and cats that can also infect a wide range of additional mammals including cows where it can cause mastitis. It is also an emerging human pathogen. Results Here we provide characterization of the first genome sequence for this species, strain FSL S3-227 (milk isolate from a cow with an intra-mammary infection). A diverse array of putative virulence factors was encoded by the S. canis FSL S3-227 genome. Approximately 75% of these gene sequences were homologous to known Streptococcal virulence factors involved in invasion, evasion, and colonization. Present in the genome are multiple potentially mobile genetic elements (MGEs) [plasmid, phage, integrative conjugative element (ICE)] and comparison to other species provided convincing evidence for lateral gene transfer (LGT) between S. canis and two additional bovine mastitis causing pathogens (Streptococcus agalactiae, and Streptococcus dysgalactiae subsp. dysgalactiae), with this transfer possibly contributing to host adaptation. Population structure among isolates obtained from Europe and USA [bovine = 56, canine = 26, and feline = 1] was explored. Ribotyping of all isolates and multi locus sequence typing (MLST) of a subset of the isolates (n = 45) detected significant differentiation between bovine and canine isolates (Fisher exact test: P = 0.0000 [ribotypes], P = 0.0030 [sequence types]), suggesting possible host adaptation of some genotypes. Concurrently, the ancestral clonal complex (54% of isolates) occurred in many tissue types, all hosts, and all geographic locations suggesting the possibility of a wide and diverse niche. Conclusion This study provides evidence highlighting the importance of LGT in the evolution of the bacteria S. canis, specifically, its possible role in host adaptation and acquisition of virulence factors. Furthermore, recent LGT detected between S. canis and human bacteria (Streptococcus

  11. Evidence for niche adaptation in the genome of the bovine pathogen Streptococcus uberis

    PubMed Central

    Ward, Philip N; Holden, Matthew TG; Leigh, James A; Lennard, Nicola; Bignell, Alexandra; Barron, Andy; Clark, Louise; Quail, Michael A; Woodward, John; Barrell, Bart G; Egan, Sharon A; Field, Terence R; Maskell, Duncan; Kehoe, Michael; Dowson, Christopher G; Chanter, Neil; Whatmore, Adrian M; Bentley, Stephen D; Parkhill, Julian

    2009-01-01

    Background Streptococcus uberis, a Gram positive bacterial pathogen responsible for a significant proportion of bovine mastitis in commercial dairy herds, colonises multiple body sites of the cow including the gut, genital tract and mammary gland. Comparative analysis of the complete genome sequence of S. uberis strain 0140J was undertaken to help elucidate the biology of this effective bovine pathogen. Results The genome revealed 1,825 predicted coding sequences (CDSs) of which 62 were identified as pseudogenes or gene fragments. Comparisons with related pyogenic streptococci identified a conserved core (40%) of orthologous CDSs. Intriguingly, S. uberis 0140J displayed a lower number of mobile genetic elements when compared with other pyogenic streptococci, however bacteriophage-derived islands and a putative genomic island were identified. Comparative genomics analysis revealed most similarity to the genomes of Streptococcus agalactiae and Streptococcus equi subsp. zooepidemicus. In contrast, streptococcal orthologs were not identified for 11% of the CDSs, indicating either unique retention of ancestral sequence, or acquisition of sequence from alternative sources. Functions including transport, catabolism, regulation and CDSs encoding cell envelope proteins were over-represented in this unique gene set; a limited array of putative virulence CDSs were identified. Conclusion S. uberis utilises nutritional flexibility derived from a diversity of metabolic options to successfully occupy a discrete ecological niche. The features observed in S. uberis are strongly suggestive of an opportunistic pathogen adapted to challenging and changing environmental parameters. PMID:19175920

  12. In vitro susceptibility of porcine respiratory pathogens to tilmicosin.

    PubMed

    DeRosa, D C; Veenhuizen, M F; Bade, D J; Shryock, T R

    2000-11-01

    Bacterial isolates obtained from swine with various clinical diseases were tested for susceptibility to tilmicosin by minimum inhibitory concentration (MIC) and Kirby-Bauer disk diffusion tests using National Committee on Clinical Laboratory Standards methodology. The tilmicosin MIC90 was < or =0.125 microg/ml for Erysiopelothrix rhusiopathiae, < or = 1 microg/ml for Haemophilus parasuis isolates, 8 microg/ml for Actinobacillus suis and Pasteurella multocida type A, 16 microg/ml for toxigenic and nontoxigenic P. multocida type D, 64 microg/ml for Bordetella bronchiseptica, and >128 microg/ml for Staphylococcus hyicus and Streptococcus suis. The results of disk diffusion testing matched well with the MIC results for each pathogen. This in vitro survey of tilmicosin activity against various swine isolates suggests that further clinical evaluation of tilmicosin in swine may be warranted for disease associated with E. rhusiopathiae, H. parasuis, and A. suis but not B. bronchiseptica, S. suis, or S. hyicus. PMID:11108454

  13. A Glimpse of Streptococcal Toxic Shock Syndrome from Comparative Genomics of S. suis 2 Chinese Isolates

    PubMed Central

    Wang, Jing; Zheng, Feng; Pan, Xiuzhen; Liu, Di; Li, Ming; Song, Yajun; Zhu, Xinxing; Sun, Haibo; Feng, Tao; Guo, Zhaobiao; Ju, Aiping; Ge, Junchao; Dong, Yaqing; Sun, Wen; Jiang, Yongqiang; Wang, Jun; Yan, Jinghua; Yang, Huanming; Wang, Xiaoning; Gao, George F.; Yang, Ruifu; Wang, Jian; Yu, Jun

    2007-01-01

    Background Streptococcus suis serotype 2 (SS2) is an important zoonotic pathogen, causing more than 200 cases of severe human infection worldwide, with the hallmarks of meningitis, septicemia, arthritis, etc. Very recently, SS2 has been recognized as an etiological agent for streptococcal toxic shock syndrome (STSS), which was originally associated with Streptococcus pyogenes (GAS) in Streptococci. However, the molecular mechanisms underlying STSS are poorly understood. Methods and Findings To elucidate the genetic determinants of STSS caused by SS2, whole genome sequencing of 3 different Chinese SS2 strains was undertaken. Comparative genomics accompanied by several lines of experiments, including experimental animal infection, PCR assay, and expression analysis, were utilized to further dissect a candidate pathogenicity island (PAI). Here we show, for the first time, a novel molecular insight into Chinese isolates of highly invasive SS2, which caused two large-scale human STSS outbreaks in China. A candidate PAI of ∼89 kb in length, which is designated 89K and specific for Chinese SS2 virulent isolates, was investigated at the genomic level. It shares the universal properties of PAIs such as distinct GC content, consistent with its pivotal role in STSS and high virulence. Conclusions To our knowledge, this is the first PAI candidate from S. suis worldwide. Our finding thus sheds light on STSS triggered by SS2 at the genomic level, facilitates further understanding of its pathogenesis and points to directions of development on some effective strategies to combat highly pathogenic SS2 infections. PMID:17375201

  14. Transcriptome Remodeling Contributes to Epidemic Disease Caused by the Human Pathogen Streptococcus pyogenes

    PubMed Central

    Beres, Stephen B.; Kachroo, Priyanka; Nasser, Waleed; Olsen, Randall J.; Zhu, Luchang; Flores, Anthony R.; de la Riva, Ivan; Paez-Mayorga, Jesus; Jimenez, Francisco E.; Cantu, Concepcion; Vuopio, Jaana; Jalava, Jari; Kristinsson, Karl G.; Gottfredsson, Magnus; Corander, Jukka; Fittipaldi, Nahuel; Di Luca, Maria Chiara; Petrelli, Dezemona; Vitali, Luca A.; Raiford, Annessa; Jenkins, Leslie

    2016-01-01

    ABSTRACT For over a century, a fundamental objective in infection biology research has been to understand the molecular processes contributing to the origin and perpetuation of epidemics. Divergent hypotheses have emerged concerning the extent to which environmental events or pathogen evolution dominates in these processes. Remarkably few studies bear on this important issue. Based on population pathogenomic analysis of 1,200 Streptococcus pyogenes type emm89 infection isolates, we report that a series of horizontal gene transfer events produced a new pathogenic genotype with increased ability to cause infection, leading to an epidemic wave of disease on at least two continents. In the aggregate, these and other genetic changes substantially remodeled the transcriptomes of the evolved progeny, causing extensive differential expression of virulence genes and altered pathogen-host interaction, including enhanced immune evasion. Our findings delineate the precise molecular genetic changes that occurred and enhance our understanding of the evolutionary processes that contribute to the emergence and persistence of epidemically successful pathogen clones. The data have significant implications for understanding bacterial epidemics and for translational research efforts to blunt their detrimental effects. PMID:27247229

  15. Essential Genes in the Core Genome of the Human Pathogen Streptococcus pyogenes

    PubMed Central

    Le Breton, Yoann; Belew, Ashton T.; Valdes, Kayla M.; Islam, Emrul; Curry, Patrick; Tettelin, Hervé; Shirtliff, Mark E.; El-Sayed, Najib M.; McIver, Kevin S.

    2015-01-01

    Streptococcus pyogenes (Group A Streptococcus, GAS) remains a major public health burden worldwide, infecting over 750 million people leading to over 500,000 deaths annually. GAS pathogenesis is complex, involving genetically distinct GAS strains and multiple infection sites. To overcome fastidious genetic manipulations and accelerate pathogenesis investigations in GAS, we developed a mariner-based system (Krmit) for en masse monitoring of complex mutant pools by transposon sequencing (Tn-seq). Highly saturated transposant libraries (Krmit insertions in ca. every 25 nucleotides) were generated in two distinct GAS clinical isolates, a serotype M1T1 invasive strain 5448 and a nephritogenic serotype M49 strain NZ131, and analyzed using a Bayesian statistical model to predict GAS essential genes, identifying sets of 227 and 241 of those genes in 5448 and NZ131, respectively. A large proportion of GAS essential genes corresponded to key cellular processes and metabolic pathways, and 177 were found conserved within the GAS core genome established from 20 available GAS genomes. Selected essential genes were validated using conditional-expression mutants. Finally, comparison to previous essentiality analyses in S. sanguinis and S. pneumoniae revealed significant overlaps, providing valuable insights for the development of new antimicrobials to treat infections by GAS and other pathogenic streptococci. PMID:25996237

  16. Molecular and genomic characterization of pathogenic traits of group A Streptococcus pyogenes

    PubMed Central

    HAMADA, Shigeyuki; KAWABATA, Shigetada; NAKAGAWA, Ichiro

    2015-01-01

    Group A streptococcus (GAS) or Streptococcus pyogenes causes various diseases ranging from self-limiting sore throat to deadly invasive diseases. The genome size of GAS is 1.85–1.9 Mb, and genomic rearrangement has been demonstrated. GAS possesses various surface-associated substances such as hyaluronic capsule, M proteins, and fibronectin/laminin/immunoglobulin-binding proteins. These are related to the virulence and play multifaceted and mutually reflected roles in the pathogenesis of GAS infections. Invasion of GAS into epithelial cells and deeper tissues provokes immune and non-immune defense or inflammatory responses including the recruitment of neutrophils, macrophages, and dendritic cells in hosts. GAS frequently evades host defense mechanisms by using its virulence factors. Extracellular products of GAS may perturb cellular and subcellular functions and degrade tissues enzymatically, which leads to the aggravation of local and/or systemic disorders in the host. In this review, we summarize some important cellular and extracellular substances that may affect pathogenic processes during GAS infections, and the host responses to these. PMID:26666305

  17. Streptococcus agalactiae, an emerging pathogen for cultured ya-fish, Schizothorax prenanti, in China.

    PubMed

    Geng, Y; Wang, K Y; Huang, X L; Chen, D F; Li, C W; Ren, S Y; Liao, Y T; Zhou, Z Y; Liu, Q F; Du, Z J; Lai, W M

    2012-08-01

    Streptococcus agalactiae (Group B streptococcus) has emerged as an important pathogen that affects humans and animals, including aquatic species. S. agalactiae infections are becoming an increasing problem in aquaculture and have been reported worldwide in a variety of fish species, especially those living in warm water. Recently, a very serious infectious disease of unknown aetiology broke out in ya-fish (Schizothorax prenanti) farms in Sichuan Province. A Gram-positive, chain-forming coccus was isolated from moribund cultured ya-fish. The goals of this study were to identify the bacterial strains isolated from diseased fish between 2009 and 2011 in Sichuan Province, China, to evaluate the pathogenicity of the pathogen in ya-fish, crucian carp (Carassius carassius) and the Nile tilapia (Oreochromis niloticus); and to determine the susceptibility of the pathogen strains to many currently available anti-microbial agents. The virulence tests were conducted by intraperitoneal injection of bacterial suspensions. In this study, four strains of a Gram-positive, chain-forming coccus were isolated from moribund cultured ya-fish (S. prenanti). The coccoid microorganism was identified as S. agalactiae using a commercial streptococcal grouping kit and 16S rDNA sequencing analysis. Susceptibility of the isolates to 22 antibiotics was tested using the disc diffusion method. All isolates showed a similar antibiotic susceptibility, which were sensitive to amoxicillin, ciprofloxacin, lomefloxacin, chloramphenicol, rifampin, vancomycin, azithromycin, florfenicol, cefalexin, cefradine and deoxycycline and resistant to gentamicin, sinomin (SMZ/TMP), penicillin, tenemycin, fradiomycin and streptomycin. Furthermore, the virulence tests were conducted by intraperitoneal injection of the isolated strain GY101 in ya-fish, crucian carp and the Nile tilapia. This coccus was lethal to ya-fish, Nile tilapia and crucian carp. The mortality rates of infected ya-fish were 100%, 100%, 60% and 20

  18. Preliminary crystallographic studies of purine nucleoside phosphorylase from the cariogenic pathogen Streptococcus mutans

    PubMed Central

    Hou, Qiao-Ming; Liu, Xiang; Brostromer, Erik; Li, Lan-Fen; Su, Xiao-Dong

    2009-01-01

    The punA gene of the cariogenic pathogen Streptococcus mutans encodes purine nucleoside phosphorylase (PNP), which is a pivotal enzyme in the nucleotide-salvage pathway, catalyzing the phosphorolysis of purine nucleosides to generate purine bases and α-ribose 1-phosphate. In the present work, the PNP protein was expressed in Escherichia coli strain BL21 (DE3) in a soluble form at a high level. After purification of the PNP enzyme, the protein was crystallized using the sitting-drop vapour-diffusion technique; the crystals diffracted to 1.6 Å resolution at best. The crystals belonged to space group H3, with unit-cell parameters a = b = 113.0, c = 60.1 Å. PMID:20054131

  19. Genome specialization and decay of the strangles pathogen, Streptococcus equi, is driven by persistent infection

    PubMed Central

    Harris, Simon R.; Robinson, Carl; Steward, Karen F.; Webb, Katy S.; Paillot, Romain; Parkhill, Julian; Holden, Matthew T.G.; Waller, Andrew S.

    2015-01-01

    Strangles, the most frequently diagnosed infectious disease of horses worldwide, is caused by Streptococcus equi. Despite its prevalence, the global diversity and mechanisms underlying the evolution of S. equi as a host-restricted pathogen remain poorly understood. Here, we define the global population structure of this important pathogen and reveal a population replacement in the late 19th or early 20th Century. Our data reveal a dynamic genome that continues to mutate and decay, but also to amplify and acquire genes despite the organism having lost its natural competence and become host-restricted. The lifestyle of S. equi within the horse is defined by short-term acute disease, strangles, followed by long-term infection. Population analysis reveals evidence of convergent evolution in isolates from post-acute disease samples as a result of niche adaptation to persistent infection within a host. Mutations that lead to metabolic streamlining and the loss of virulence determinants are more frequently found in persistent isolates, suggesting that the pathogenic potential of S. equi reduces as a consequence of long-term residency within the horse post-acute disease. An example of this is the deletion of the equibactin siderophore locus that is associated with iron acquisition, which occurs exclusively in persistent isolates, and renders S. equi significantly less able to cause acute disease in the natural host. We identify several loci that may similarly be required for the full virulence of S. equi, directing future research toward the development of new vaccines against this host-restricted pathogen. PMID:26160165

  20. The Human Pathogen Streptococcus pyogenes Releases Lipoproteins as Lipoprotein-rich Membrane Vesicles*

    PubMed Central

    Biagini, Massimiliano; Garibaldi, Manuela; Aprea, Susanna; Pezzicoli, Alfredo; Doro, Francesco; Becherelli, Marco; Taddei, Anna Rita; Tani, Chiara; Tavarini, Simona; Mora, Marirosa; Teti, Giuseppe; D'Oro, Ugo; Nuti, Sandra; Soriani, Marco; Margarit, Immaculada; Rappuoli, Rino; Grandi, Guido; Norais, Nathalie

    2015-01-01

    Bacterial lipoproteins are attractive vaccine candidates because they represent a major class of cell surface-exposed proteins in many bacteria and are considered as potential pathogen-associated molecular patterns sensed by Toll-like receptors with built-in adjuvanticity. Although Gram-negative lipoproteins have been extensively characterized, little is known about Gram-positive lipoproteins. We isolated from Streptococcus pyogenes a large amount of lipoproteins organized in vesicles. These vesicles were obtained by weakening the bacterial cell wall with a sublethal concentration of penicillin. Lipid and proteomic analysis of the vesicles revealed that they were enriched in phosphatidylglycerol and almost exclusively composed of lipoproteins. In association with lipoproteins, a few hypothetical proteins, penicillin-binding proteins, and several members of the ExPortal, a membrane microdomain responsible for the maturation of secreted proteins, were identified. The typical lipidic moiety was apparently not necessary for lipoprotein insertion in the vesicle bilayer because they were also recovered from the isogenic diacylglyceryl transferase deletion mutant. The vesicles were not able to activate specific Toll-like receptor 2, indicating that lipoproteins organized in these vesicular structures do not act as pathogen-associated molecular patterns. In light of these findings, we propose to name these new structures Lipoprotein-rich Membrane Vesicles. PMID:26018414

  1. The novel polysaccharide deacetylase homologue Pdi contributes to virulence of the aquatic pathogen Streptococcus iniae

    PubMed Central

    Milani, Carlo J. E.; Aziz, Ramy K.; Locke, Jeffrey B.; Dahesh, Samira; Nizet, Victor; Buchanan, John T.

    2010-01-01

    The aquatic zoonotic pathogen Streptococcus iniae represents a threat to the worldwide aquaculture industry and poses a risk to humans who handle raw fish. Because little is known about the mechanisms of S. iniae pathogenesis or virulence factors, we established a high-throughput system combining whole-genome pyrosequencing and transposon mutagenesis that allowed us to identify virulence proteins, including Pdi, the polysaccharide deacetylase of S. iniae, that we describe here. Using bioinformatics tools, we identified a highly conserved signature motif in Pdi that is also conserved in the peptidoglycan deacetylase PgdA protein family. A Δpdi mutant was attenuated for virulence in the hybrid striped bass model and for survival in whole fish blood. Moreover, Pdi was found to promote bacterial resistance to lysozyme killing and the ability to adhere to and invade epithelial cells. On the other hand, there was no difference in the autolytic potential, resistance to oxidative killing or resistance to cationic antimicrobial peptides between S. iniae wild-type and Δpdi. In conclusion, we have demonstrated that pdi is involved in S. iniae adherence and invasion, lysozyme resistance and survival in fish blood, and have shown that pdi plays a role in the pathogenesis of S. iniae. Identification of Pdi and other S. iniae virulence proteins is a necessary initial step towards the development of appropriate preventive and therapeutic measures against diseases and economic losses caused by this pathogen. PMID:19762441

  2. Variation in the group B Streptococcus CsrRS regulon and effects on pathogenicity.

    PubMed

    Jiang, Sheng-Mei; Ishmael, Nadeeza; Dunning Hotopp, Julie; Puliti, Manuela; Tissi, Luciana; Kumar, Nikhil; Cieslewicz, Michael J; Tettelin, Hervé; Wessels, Michael R

    2008-03-01

    CsrRS (or CovRS) is a two-component regulatory system that controls expression of multiple virulence factors in the important human pathogen group B Streptococcus (GBS). We now report global gene expression studies in GBS strains 2603V/R and 515 and their isogenic csrR and csrS mutants. Together with data reported previously for strain NEM316, the results reveal a conserved 39-gene CsrRS regulon. In vitro phosphorylation-dependent binding of recombinant CsrR to promoter regions of both positively and negatively regulated genes suggests that direct binding of CsrR can mediate activation as well as repression of target gene expression. Distinct patterns of gene regulation in csrR versus csrS mutants in strain 2603V/R compared to 515 were associated with different hierarchies of relative virulence of wild-type, csrR, and csrS mutants in murine models of systemic infection and septic arthritis. We conclude that CsrRS regulates a core group of genes including important virulence factors in diverse strains of GBS but also displays marked variability in the repertoire of regulated genes and in the relative effects of CsrS signaling on CsrR-mediated gene regulation. Such variation is likely to play an important role in strain-specific adaptation of GBS to particular host environments and pathogenic potential in susceptible hosts. PMID:18203834

  3. Molecular mapping of the cell wall polysaccharides of the human pathogen Streptococcus agalactiae

    NASA Astrophysics Data System (ADS)

    Beaussart, Audrey; Péchoux, Christine; Trieu-Cuot, Patrick; Hols, Pascal; Mistou, Michel-Yves; Dufrêne, Yves F.

    2014-11-01

    The surface of many bacterial pathogens is covered with polysaccharides that play important roles in mediating pathogen-host interactions. In Streptococcus agalactiae, the capsular polysaccharide (CPS) is recognized as a major virulence factor while the group B carbohydrate (GBC) is crucial for peptidoglycan biosynthesis and cell division. Despite the important roles of CPS and GBC, there is little information available on the molecular organization of these glycopolymers on the cell surface. Here, we use atomic force microscopy (AFM) and transmission electron microscopy (TEM) to analyze the nanoscale distribution of CPS and GBC in wild-type (WT) and mutant strains of S. agalactiae. TEM analyses reveal that in WT bacteria, peptidoglycan is covered with a very thin (few nm) layer of GBC (the ``pellicle'') overlaid by a 15-45 nm thick layer of CPS (the ``capsule''). AFM-based single-molecule mapping with specific antibody probes shows that CPS is exposed on WT cells, while it is hardly detected on mutant cells impaired in CPS production (ΔcpsE mutant). By contrast, both TEM and AFM show that CPS is over-expressed in mutant cells altered in GBC expression (ΔgbcO mutant), indicating that the production of the two surface glycopolymers is coordinated in WT cells. In addition, AFM topographic imaging and molecular mapping with specific lectin probes demonstrate that removal of CPS (ΔcpsE), but not of GBC (ΔgbcO), leads to the exposure of peptidoglycan, organized into 25 nm wide bands running parallel to the septum. These results indicate that CPS forms a homogeneous barrier protecting the underlying peptidoglycan from environmental exposure, while the presence of GBC does not prevent peptidoglycan detection. This work shows that single-molecule AFM, combined with high-resolution TEM, represents a powerful platform for analysing the molecular arrangement of the cell wall polymers of bacterial pathogens.

  4. Regulatory rewiring confers serotype-specific hyper-virulence in the human pathogen group A Streptococcus.

    PubMed

    Miller, Eric W; Danger, Jessica L; Ramalinga, Anupama B; Horstmann, Nicola; Shelburne, Samuel A; Sumby, Paul

    2015-10-01

    Phenotypic heterogeneity is commonly observed between isolates of a given pathogen. Epidemiological analyses have identified that some serotypes of the group A Streptococcus (GAS) are non-randomly associated with particular disease manifestations. Here, we present evidence that a contributing factor to the association of serotype M3 GAS isolates with severe invasive infections is the presence of a null mutant allele for the orphan kinase RocA. Through use of RNAseq analysis, we identified that the natural rocA mutation present within M3 isolates leads to the enhanced expression of more than a dozen immunomodulatory virulence factors, enhancing phenotypes such as hemolysis and NAD(+) hydrolysis. Consequently, an M3 GAS isolate survived human phagocytic killing at a level 13-fold higher than a rocA complemented derivative, and was significantly more virulent in a murine bacteremia model of infection. Finally, we identified that RocA functions through the CovR/S two-component system as levels of phosphorylated CovR increase in the presence of functional RocA, and RocA has no regulatory activity following covR or covS mutation. Our data are consistent with RocA interfacing with the CovR/S two-component system, and that the absence of this activity in M3 GAS potentiates the severity of invasive infections caused by isolates of this serotype. PMID:26192205

  5. Preliminary X-ray crystallographic analysis of SMU.2055 protein from the caries pathogen Streptococcus mutans

    PubMed Central

    Zhao, Wang-Hong; Zhan, Xiu-Rong; Gao, Xiong-Zhuo; Liu, Xiang; Zhang, Yi-Fei; Lin, Jiuxiang; Li, Lan-Fen; Wei, Shi-Cheng; Su, Xio-Dong

    2010-01-01

    The SMU.2055 gene from the major caries pathogen Streptococcus mutans is annotated as a putative acetyltransferase with 163 amino-acid residues. In order to identify its function via structural studies, the SMU.2055 gene was cloned into the expression vector pET28a. Native and SeMet-labelled SMU.2055 proteins with a His6 tag at the N-terminus were expressed at a high level in Escherichia coli strain BL21 (DE3) and purified to homogeneity by Ni2+-chelating affinity chromatography. Diffraction-quality crystals of SeMet-labelled SMU.2055 were obtained using the sitting-drop vapour-diffusion method and diffracted to a resolution of 2.5 Å on beamline BL17A at the Photon Factory, Tsukuba, Japan. The crystals belong to the orthorhombic space group C2221, with unit-cell parameters a = 92.0, b = 95.0, c = 192.2 Å. The asymmetric unit contained four molecules, with a solvent content of 57.1%. PMID:20445252

  6. Bright Fluorescent Streptococcus pneumoniae for Live-Cell Imaging of Host-Pathogen Interactions

    PubMed Central

    Kjos, Morten; Aprianto, Rieza; Fernandes, Vitor E.; Andrew, Peter W.; van Strijp, Jos A. G.; Nijland, Reindert

    2014-01-01

    Streptococcus pneumoniae is a common nasopharyngeal resident in healthy people but, at the same time, one of the major causes of infectious diseases such as pneumonia, meningitis, and sepsis. The shift from commensal to pathogen and its interaction with host cells are poorly understood. One of the major limitations for research on pneumococcal-host interactions is the lack of suitable tools for live-cell imaging. To address this issue, we developed a generally applicable strategy to create genetically stable, highly fluorescent bacteria. Our strategy relies on fusing superfolder green fluorescent protein (GFP) or a far-red fluorescent protein (RFP) to the abundant histone-like protein HlpA. Due to efficient translation and limited cellular diffusion of these fusions, the cells are 25-fold brighter than those of the currently best available imaging S. pneumoniae strain. These novel bright pneumococcal strains are fully virulent, and the GFP reporter can be used for in situ imaging in mouse tissue. We used our reporter strains to study the effect of the polysaccharide capsule, a major pneumococcal virulence factor, on different stages of infection. By dual-color live-cell imaging experiments, we show that unencapsulated pneumococci adhere significantly better to human lung epithelial cells than encapsulated strains, in line with previous data obtained by classical approaches. We also confirm with live-cell imaging that the capsule protects pneumococci from neutrophil phagocytosis, demonstrating the versatility and usability of our reporters. The described imaging tools will pave the way for live-cell imaging of pneumococcal infection and help further understanding of the mechanisms of pneumococcal pathogenesis. PMID:25512311

  7. Endocytosis‒Mediated Invasion and Pathogenicity of Streptococcus agalactiae in Rat Cardiomyocyte (H9C2)

    PubMed Central

    Pooja, Sharma; Pushpanathan, Muthuirulan; Gunasekaran, Paramasamy; Rajendhran, Jeyaprakash

    2015-01-01

    Streptococcus agalactiae infection causes high mortality in cardiovascular disease (CVD) patients, especially in case of setting prosthetic valve during cardiac surgery. However, the pathogenesis mechanism of S. agalactiae associate with CVD has not been well studied. Here, we have demonstrated the pathogenicity of S. agalactiae in rat cardiomyocytes (H9C2). Interestingly, both live and dead cells of S. agalactiae were uptaken by H9C2 cells. To further dissect the process of S. agalactiae internalization, we chemically inhibited discrete parts of cellular uptake system in H9C2 cells using genistein, chlorpromazine, nocodazole and cytochalasin B. Chemical inhibition of microtubule and actin formation by nocodazole and cytochalasin B impaired S. agalactiae internalization into H9C2 cells. Consistently, reverse‒ transcription PCR (RT‒PCR) and quantitative real time‒PCR (RT-qPCR) analyses also detected higher levels of transcripts for cytoskeleton forming genes, Acta1 and Tubb5 in S. agalactiae‒infected H9C2 cells, suggesting the requirement of functional cytoskeleton in pathogenesis. Host survival assay demonstrated that S. agalactiae internalization induced cytotoxicity in H9C2 cells. S. agalactiae cells grown with benzyl penicillin reduced its ability to internalize and induce cytotoxicity in H9C2 cells, which could be attributed with the removal of surface lipoteichoic acid (LTA) from S. agalactiae. Further, the LTA extracted from S. agalactiae also exhibited dose‒dependent cytotoxicity in H9C2 cells. Taken together, our data suggest that S. agalactiae cells internalized H9C2 cells through energy‒dependent endocytic processes and the LTA of S. agalactiae play major role in host cell internalization and cytotoxicity induction. PMID:26431539

  8. Antimicrobial susceptibility pattern of Helicobacter suis strains.

    PubMed

    Vermoote, Miet; Pasmans, Frank; Flahou, Bram; Van Deun, Kim; Ducatelle, Richard; Haesebrouck, Freddy

    2011-12-15

    Helicobacter suis is a very fastidious porcine gastric pathogen, which is also considered to be of zoonotic importance. In vitro antimicrobial susceptibility cannot be determined using standard assays, as this agent only grows in a biphasic medium with an acidic pH. Therefore, a combined agar and broth dilution method was used to analyse the activity of nine antimicrobial agents against nine H. suis isolates. After 48 h microaerobic incubation, minimal inhibitory concentrations (MICs) were determined by software-assisted calculation of bacterial growth. Only for enrofloxacin a bimodal distribution of MICs was demonstrated, indicating acquired resistance in one strain, which showed an AGT→AGG (Ser→Arg) substitution at codon 99 of gyrA. In conclusion, the assay developed here is suitable for determination of the antimicrobial susceptibility of H. suis isolates, although activity of acid sensitive antimicrobial agents may be higher than predicted from MIC endpoints. PMID:21733643

  9. Insight into the specific virulence related genes and toxin-antitoxin virulent pathogenicity islands in swine streptococcosis pathogen Streptococcus equi ssp. zooepidemicus strain ATCC35246

    PubMed Central

    2013-01-01

    Background Streptococcus equi ssp. zooepidemicus (S. zooepidemicus) is an important pathogen causing swine streptococcosis in China. Pathogenicity islands (PAIs) of S. zooepidemicus have been transferred among bacteria through horizontal gene transfer (HGT) and play important roles in the adaptation and increased virulence of S. zooepidemicus. The present study used comparative genomics to examine the different pathogenicities of S. zooepidemicus. Results Genome of S. zooepidemicus ATCC35246 (Sz35246) comprises 2,167,264-bp of a single circular chromosome, with a GC content of 41.65%. Comparative genome analysis of Sz35246, S. zooepidemicus MGCS10565 (Sz10565), Streptococcus equi. ssp. equi. 4047 (Se4047) and S. zooepidemicus H70 (Sz70) identified 320 Sz35246-specific genes, clustered into three toxin-antitoxin (TA) systems PAIs and one restriction modification system (RM system) PAI. These four acquired PAIs encode proteins that may contribute to the overall pathogenic capacity and fitness of this bacterium to adapt to different hosts. Analysis of the in vivo and in vitro transcriptomes of this bacterium revealed differentially expressed PAI genes and non-PAI genes, suggesting that Sz35246 possess mechanisms for infecting animals and adapting to a wide range of host environments. Analysis of the genome identified potential Sz35246 virulence genes. Genes of the Fim III operon were presumed to be involved in breaking the host-restriction of Sz35246. Conclusion Genome wide comparisons of Sz35246 with three other strains and transcriptome analysis revealed novel genes related to bacterial virulence and breaking the host-restriction. Four specific PAIs, which were judged to have been transferred into Sz35246 genome through HGT, were identified for the first time. Further analysis of the TA and RM systems in the PAIs will improve our understanding of the pathogenicity of this bacterium and could lead to the development of diagnostics and vaccines. PMID:23742619

  10. Host-pathogen interactions in bacterial meningitis.

    PubMed

    Doran, Kelly S; Fulde, Marcus; Gratz, Nina; Kim, Brandon J; Nau, Roland; Prasadarao, Nemani; Schubert-Unkmeir, Alexandra; Tuomanen, Elaine I; Valentin-Weigand, Peter

    2016-02-01

    Bacterial meningitis is a devastating disease occurring worldwide with up to half of the survivors left with permanent neurological sequelae. Due to intrinsic properties of the meningeal pathogens and the host responses they induce, infection can cause relatively specific lesions and clinical syndromes that result from interference with the function of the affected nervous system tissue. Pathogenesis is based on complex host-pathogen interactions, some of which are specific for certain bacteria, whereas others are shared among different pathogens. In this review, we summarize the recent progress made in understanding the molecular and cellular events involved in these interactions. We focus on selected major pathogens, Streptococcus pneumonia, S. agalactiae (Group B Streptococcus), Neisseria meningitidis, and Escherichia coli K1, and also include a neglected zoonotic pathogen, Streptococcus suis. These neuroinvasive pathogens represent common themes of host-pathogen interactions, such as colonization and invasion of mucosal barriers, survival in the blood stream, entry into the central nervous system by translocation of the blood-brain and blood-cerebrospinal fluid barrier, and induction of meningeal inflammation, affecting pia mater, the arachnoid and subarachnoid spaces. PMID:26744349

  11. Investigations of selected pathogens among village pigs in Central Papua, Indonesia.

    PubMed

    Nugroho, Widi; Cargill, Colin Frank; Putra, I Made; Kirkwood, Roy Neville; Trott, Darren John; Salasia, Siti Isrina Oktavia; Slipranata, Mitra; Reichel, Michael Philipp

    2016-01-01

    Village pig husbandry is an important part of livestock production in Papua Province, Eastern Indonesia. However, high level of disease and mortality constrains production. The aim of this study was to investigate the prevalence of the selected pathogens in village pigs in the Jayawijaya Region of Papua Province, Indonesia. Two studies were conducted: Study 1 determined the prevalence of selected pathogens in dead or moribund pigs sent to the main local market for sale. Study 2 recorded the prevalence of the selected pathogens, on pig farms in the Subdistrict of Wamena that had not recorded a case of pig mortality during the duration of Study 1. Blood samples of individuals from both groups were tested for CSF antigen and antibody, as well as antibody against PCV2. Organs with evident pathological changes from Study 1 and tonsilar swabs from Study 2 were subjected to bacteriological culture and identification of Streptococcus suis and Streptococcus zooepidemicus. Faecal samples from both studies were examined for eggs of strongyle parasites, Trichuris suis, Ascaris suum, Strongyloides ransomi and coccidia. The main infections in both studies were CSF, PCV2 and strongyle parasites, but prevalence was higher in Study 1 (P < 0.05). T. suis and S. zooepidemicus were prevalent in pigs in Study 1, but rare in healthy pigs (P < 0.05). Infections with coccidia, A. suum and S. ransomi were common but did not differ between groups (P < 0.05), with S. suis infections uncommon in both studies. This suggests that infections with CSF, PCV2, strongyle and T. suis are important pathogens in village pig farms in Jayawijaya. Local pig husbandry practices, such as confining pigs and heat-treating pig feeds, may be practical solutions to help minimize infection in village pigs in Jayawijaya. PMID:26381546

  12. The Complete Genome of Brucella Suis 019 Provides Insights on Cross-Species Infection

    PubMed Central

    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

    2016-01-01

    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

  13. The Complete Genome of Brucella Suis 019 Provides Insights on Cross-Species Infection.

    PubMed

    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

    2016-01-01

    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

  14. Strain-dependent disruption of blood-cerebrospinal fluid barrier by Streptoccocus suis in vitro.

    PubMed

    Tenenbaum, Tobias; Adam, Rüdiger; Eggelnpöhler, Ingo; Matalon, David; Seibt, Annette; K Novotny, Gerd E; Galla, Hans-Joachim; Schroten, Horst

    2005-04-01

    Streptococcus suis capsular type 2 is an important agent of diseases including meningitis among pigs worldwide, and is also a zoonotic agent. The barrier function of the choroid plexus epithelium that constitutes the structural basis for the blood-cerebrospinal fluid (CSF) barrier has not been elucidated yet in bacterial meningitis. We investigated the influence of various S. suis isolates on the barrier function of cultured porcine choroid plexus epithelial cells with respect to the transepithelial resistance and paracellular [(3)H]-mannitol flux. Preferentially apical application of S. suis isolates significantly decreased transepithelial resistance and significantly increased paracellular [(3)H]-mannitol flux in a time-, dose- and strain-dependent manner. Viable S. suis isolates caused cytotoxicity determined by lactate dehydrogenase assay and electron microscopy, whereas S. suis sonicates and UV-inactivated S. suis did not cause cytotoxicity. The observed effects on porcine choroid plexus epithelial cells barrier function could not exclusively be ascribed to known virulence factors of S. suis such as suilysin. In conclusion, S. suis isolates induce loss of blood-cerebrospinal fluid barrier function in an in vitro model. Thus, S. suis may facilitate trafficking of bacteria and leucocytes across the blood-cerebrospinal fluid barrier. The underlying mechanisms for the barrier breakdown have yet to be determined. PMID:15780575

  15. RNA-mediated regulation in Gram-positive pathogens: an overview punctuated with examples from the group A Streptococcus

    PubMed Central

    Miller, Eric W.; Cao, Tram N.; Pflughoeft, Kathryn J.; Sumby, Paul

    2014-01-01

    RNA-based mechanisms of regulation represent a ubiquitous class of regulators that are associated with diverse processes including nutrient sensing, stress response, modulation of horizontal gene transfer, and virulence factor expression. While better studied in Gram-negative bacteria, the literature is replete with examples of the importance of RNA-mediated regulatory mechanisms to the virulence and fitness of Gram-positives. Regulatory RNAs are classified as cis-acting, e.g. riboswitches, which modulate the transcription, translation, or stability of co-transcribed RNA, or trans-acting, e.g. small regulatory RNAs, which target separate mRNAs or proteins. The group A Streptococcus (GAS, Streptococcus pyogenes) is a Gram-positive bacterial pathogen from which several regulatory RNA mechanisms have been characterized. The study of RNA-mediated regulation in GAS has uncovered novel concepts with respect to how small regulatory RNAs may positively regulate target mRNA stability, and to how CRISPR RNAs are processed from longer precursors. This review provides an overview of RNA-mediated regulation in Gram-positive bacteria, and is highlighted with specific examples from GAS research. The key roles that these systems play in regulating bacterial virulence are discussed and future perspectives outlined. PMID:25091277

  16. The periodontal pathogen Porphyromonas gingivalis induces expression of transposases and cell death of Streptococcus mitis in a biofilm model.

    PubMed

    Duran-Pinedo, Ana E; Baker, Vinesha D; Frias-Lopez, Jorge

    2014-08-01

    Oral microbial communities are extremely complex biofilms with high numbers of bacterial species interacting with each other (and the host) to maintain homeostasis of the system. Disturbance in the oral microbiome homeostasis can lead to either caries or periodontitis, two of the most common human diseases. Periodontitis is a polymicrobial disease caused by the coordinated action of a complex microbial community, which results in inflammation of tissues that support the teeth. It is the most common cause of tooth loss among adults in the United States, and recent studies have suggested that it may increase the risk for systemic conditions such as cardiovascular diseases. In a recent series of papers, Hajishengallis and coworkers proposed the idea of the "keystone-pathogen" where low-abundance microbial pathogens (Porphyromonas gingivalis) can orchestrate inflammatory disease by turning a benign microbial community into a dysbiotic one. The exact mechanisms by which these pathogens reorganize the healthy oral microbiome are still unknown. In the present manuscript, we present results demonstrating that P. gingivalis induces S. mitis death and DNA fragmentation in an in vitro biofilm system. Moreover, we report here the induction of expression of multiple transposases in a Streptococcus mitis biofilm when the periodontopathogen P. gingivalis is present. Based on these results, we hypothesize that P. gingivalis induces S. mitis cell death by an unknown mechanism, shaping the oral microbiome to its advantage. PMID:24866802

  17. The small regulatory RNA FasX controls pilus expression and adherence in the human bacterial pathogen group A Streptococcus

    PubMed Central

    Liu, Zhuyun; Treviño, Jeanette; Ramirez-Peña, Esmeralda; Sumby, Paul

    2012-01-01

    Summary Bacterial pathogens use cell-surface-associated adhesion molecules to promote host attachment and colonization, and the ability to modulate adhesion expression is critical to pathogen success. Here, we show that the human-specific pathogen the group A Streptococcus (GAS) uses a small regulatory RNA (sRNA) to regulate the expression of adhesive pili. The fibronectin / fibrinogen-binding / haemolytic-activity / streptokinase-regulator-X (FasX) sRNA, previously shown to positively regulate expression of the secreted virulence factor streptokinase (SKA), negatively regulates the production of pili on the GAS cell surface. FasX base-pairs to the extreme 5’ end of mRNA from the pilus biosynthesis operon, and this RNA:RNA interaction reduces the stability of the mRNA, while also inhibiting translation of at least the first gene in the pilus biosynthesis operon (cpa, which encodes a minor pilin protein). The negative regulation of pilus expression by FasX reduces the ability of GAS to adhere to human keratinocytes. Our findings cement FasX sRNA as an important regulator of virulence factor production in GAS and identify that FasX uses at least three distinct mechanisms, positive (ska mRNA) and negative (pilus operon mRNA) regulation of mRNA stability, and negative regulation of mRNA translation (cpa mRNA), to post-transcriptionally regulate target mRNAs during infection. PMID:22882718

  18. Association of Streptococcus pluranimalium with valvular endocarditis and septicaemia in adult broiler parents.

    PubMed

    Hedegaard, L; Christensen, H; Chadfield, M S; Christensen, J P; Bisgaard, M

    2009-04-01

    The genus Streptococcus consists of more than 60 species, but only Streptococcus equi subspecies zooepidemicus, Streptococcus gallolyticus ssp. gallolyticus, Streptococcus gallinaceus, Streptococcus dysgalactiae, Streptococcus mutans and Streptococcus suis have been isolated from poultry. During investigations of the aetiology of increased mortality in broiler parent stock at the end of production, pure cultures of streptococcal-like organisms that could not be classified among these six species were obtained from 24 cases of septicaemia or valvular endocarditis and septicaemia. Phenotypic characterization using the API20 STREP kit identified the isolates as Aerococcus viridans (10), Aerococcus urinae (2), Leuconostoc species (4), Streptococcus salivarius (2), Streptococcus bovis II 3 (1), Enterococcus avium (3), Enterococcus faecium (1) or Gemella morbillorum (1). However, this identification was misleading as subsequent genetic investigations using pulse field gel electrophoresis and sequencing of 16S rRNA genes showed that 19 isolates were classified as Streptococcus pluranimalium, while the remaining isolates were E. avium (3), E. faecium (1) or Lactobacillus species (1). Misidentification by API20 STREP was related to the database provided by the manufacturer, as the phenotypic characteristics could identify these organisms as S. pluranimalium. The isolates of S. pluranimalium belonged to at least three different clones as determined by pulsed field gel electrophoresis of SmaI-digested genomic DNA. The capacity that these isolates had to colonize the valvular endothelium was suggested by the occurrence of valvular endocarditis in 12 of 19 cases. Demonstration of the same clone in all four houses on a farm suggested the pathogenic potential of this organism. PMID:19322715

  19. Sequencing and Comparative Genome Analysis of Two Pathogenic Streptococcus gallolyticus Subspecies: Genome Plasticity, Adaptation and Virulence

    PubMed Central

    Teng, Yu-Ting; Wu, Hui-Lun; Liu, Yen-Ming; Wu, Keh-Ming; Chang, Chuan-Hsiung; Hsu, Ming-Ta

    2011-01-01

    Streptococcus gallolyticus infections in humans are often associated with bacteremia, infective endocarditis and colon cancers. The disease manifestations are different depending on the subspecies of S. gallolyticus causing the infection. Here, we present the complete genomes of S. gallolyticus ATCC 43143 (biotype I) and S. pasteurianus ATCC 43144 (biotype II.2). The genomic differences between the two biotypes were characterized with comparative genomic analyses. The chromosome of ATCC 43143 and ATCC 43144 are 2,36 and 2,10 Mb in length and encode 2246 and 1869 CDS respectively. The organization and genomic contents of both genomes were most similar to the recently published S. gallolyticus UCN34, where 2073 (92%) and 1607 (86%) of the ATCC 43143 and ATCC 43144 CDS were conserved in UCN34 respectively. There are around 600 CDS conserved in all Streptococcus genomes, indicating the Streptococcus genus has a small core-genome (constitute around 30% of total CDS) and substantial evolutionary plasticity. We identified eight and five regions of genome plasticity in ATCC 43143 and ATCC 43144 respectively. Within these regions, several proteins were recognized to contribute to the fitness and virulence of each of the two subspecies. We have also predicted putative cell-surface associated proteins that could play a role in adherence to host tissues, leading to persistent infections causing sub-acute and chronic diseases in humans. This study showed evidence that the S. gallolyticus still possesses genes making it suitable in a rumen environment, whereas the ability for S. pasteurianus to live in rumen is reduced. The genome heterogeneity and genetic diversity among the two biotypes, especially membrane and lipoproteins, most likely contribute to the differences in the pathogenesis of the two S. gallolyticus biotypes and the type of disease an infected patient eventually develops. PMID:21633709

  20. Characterization of the haem-uptake system of the equine pathogen Streptococcus equi subsp. equi.

    PubMed

    Meehan, Mary; Burke, Fiona M; Macken, Susan; Owen, Peter

    2010-06-01

    Streptococcus equi possesses a haem-uptake system homologous to that of Streptococcus pyogenes and Streptococcus zooepidemicus. The system consists of two ligand-binding proteins (Shr and Shp) and proteins (HtsA-C) with homology to an ABC transporter. The haem-uptake system of S. equi differs from that of S. pyogenes and S. zooepidemicus in that Shr is truncated by two-thirds. This study focused on the SeShr, SeShp and SeHtsA proteins of S. equi. Analysis of shr, shp and shphtsA knockout mutants showed that all three proteins were expressed in vitro and that expression was upregulated under conditions of iron limitation. SeShr possesses no membrane-/cell wall-spanning sequences and was shown to be secreted. Both SeShp and SeHtsA were confirmed to be envelope-associated. Recombinant SeShp and SeHtsA proteins have been previously shown to bind haem and SeHtsA could capture haem from SeShp. This report extends these studies and shows that both SeShp and SeHtsA can sequester haem from haemoglobin but not from haemoglobin-haptoglobin complexes. Like full-length Shr, SeShr possesses haemoglobin and haemoglobin-haptoglobin binding ability but unlike full-length Shr, it lacks haem- or fibronectin-binding capabilities. Analysis of SeShr truncates showed that residues within and upstream of the near transporter (NEAT) domain are required for this ligand binding. Structural predictions suggest that truncation of NEAT1 in SeShr accounts for its impaired ability to bind haem. Haem and haemoglobin restored to almost normal the impaired growth rates of wild-type S. equi cultured under iron-limiting conditions. However, no difference in the growth rates of wild-type and mutants could be detected under the in vitro growth conditions tested. PMID:20223800

  1. Insight into the evolution of the histidine triad protein (HTP) family in Streptococcus.

    PubMed

    Shao, Zhu-Qing; Zhang, Yan-Mei; Pan, Xiu-Zhen; Wang, Bin; Chen, Jian-Qun

    2013-01-01

    The Histidine Triad Proteins (HTPs), also known as Pht proteins in Streptococcus pneumoniae, constitute a family of surface-exposed proteins that exist in many pathogenic streptococcal species. Although many studies have revealed the importance of HTPs in streptococcal physiology and pathogenicity, little is known about their origin and evolution. In this study, after identifying all htp homologs from 105 streptococcal genomes representing 38 different species/subspecies, we analyzed their domain structures, positions in genome, and most importantly, their evolutionary histories. By further projecting this information onto the streptococcal phylogeny, we made several major findings. First, htp genes originated earlier than the Streptococcus genus and gene-loss events have occurred among three streptococcal groups, resulting in the absence of the htp gene in the Bovis, Mutans and Salivarius groups. Second, the copy number of htp genes in other groups of Streptococcus is variable, ranging from one to four functional copies. Third, both phylogenetic evidence and domain structure analyses support the division of two htp subfamilies, designated as htp I and htp II. Although present mainly in the pyogenic group and in Streptococcus suis, htp II members are distinct from htp I due to the presence of an additional leucine-rich-repeat domain at the C-terminus. Finally, htp genes exhibit a faster nucleotide substitution rate than do housekeeping genes. Specifically, the regions outside the HTP domains are under strong positive selection. This distinct evolutionary pattern likely helped Streptococcus to easily escape from recognition by host immunity. PMID:23527301

  2. A Multi-Serotype Approach Clarifies the Catabolite Control Protein A Regulon in the Major Human Pathogen Group A Streptococcus.

    PubMed

    DebRoy, Sruti; Saldaña, Miguel; Travisany, Dante; Montano, Andrew; Galloway-Peña, Jessica; Horstmann, Nicola; Yao, Hui; González, Mauricio; Maass, Alejandro; Latorre, Mauricio; Shelburne, Samuel A

    2016-01-01

    Catabolite control protein A (CcpA) is a highly conserved, master regulator of carbon source utilization in gram-positive bacteria, but the CcpA regulon remains ill-defined. In this study we aimed to clarify the CcpA regulon by determining the impact of CcpA-inactivation on the virulence and transcriptome of three distinct serotypes of the major human pathogen Group A Streptococcus (GAS). CcpA-inactivation significantly decreased GAS virulence in a broad array of animal challenge models consistent with the idea that CcpA is critical to gram-positive bacterial pathogenesis. Via comparative transcriptomics, we established that the GAS CcpA core regulon is enriched for highly conserved CcpA binding motifs (i.e. cre sites). Conversely, strain-specific differences in the CcpA transcriptome seems to consist primarily of affected secondary networks. Refinement of cre site composition via analysis of the core regulon facilitated development of a modified cre consensus that shows promise for improved prediction of CcpA targets in other medically relevant gram-positive pathogens. PMID:27580596

  3. A Multi-Serotype Approach Clarifies the Catabolite Control Protein A Regulon in the Major Human Pathogen Group A Streptococcus

    PubMed Central

    DebRoy, Sruti; Saldaña, Miguel; Travisany, Dante; Montano, Andrew; Galloway-Peña, Jessica; Horstmann, Nicola; Yao, Hui; González, Mauricio; Maass, Alejandro; Latorre, Mauricio; Shelburne, Samuel A.

    2016-01-01

    Catabolite control protein A (CcpA) is a highly conserved, master regulator of carbon source utilization in gram-positive bacteria, but the CcpA regulon remains ill-defined. In this study we aimed to clarify the CcpA regulon by determining the impact of CcpA-inactivation on the virulence and transcriptome of three distinct serotypes of the major human pathogen Group A Streptococcus (GAS). CcpA-inactivation significantly decreased GAS virulence in a broad array of animal challenge models consistent with the idea that CcpA is critical to gram-positive bacterial pathogenesis. Via comparative transcriptomics, we established that the GAS CcpA core regulon is enriched for highly conserved CcpA binding motifs (i.e. cre sites). Conversely, strain-specific differences in the CcpA transcriptome seems to consist primarily of affected secondary networks. Refinement of cre site composition via analysis of the core regulon facilitated development of a modified cre consensus that shows promise for improved prediction of CcpA targets in other medically relevant gram-positive pathogens. PMID:27580596

  4. Inhibitory Effect of Dodonaea viscosa var. angustifolia on the Virulence Properties of the Oral Pathogens Streptococcus mutans and Porphyromonas gingivalis

    PubMed Central

    Owotade, Foluso John

    2013-01-01

    Aim. This study investigated the effect of Dodonaea viscosa var. angustifolia (DVA) on the virulence properties of cariogenic Streptococcus mutans and Porphyromonas gingivalis implicated in periodontal diseases. Methods. S. mutans was cultured in tryptone broth containing a crude leaf extract of DVA for 16 hours, and the pH was measured after 10, 12, 14, and 16 h. Biofilms of S. mutans were grown on glass slides for 48 hours and exposed to plant extract for 30 minutes; the adherent cells were reincubated and the pH was measured at various time intervals. Minimum bactericidal concentration of the extracts against the four periodontal pathogens was determined. The effect of the subinhibitory concentration of plant extract on the production of proteinases by P. gingivalis was also evaluated. Results. DVA had no effect on acid production by S. mutans biofilms; however, it significantly inhibited acid production in planktonic cells. Periodontal pathogens were completely eliminated at low concentrations ranging from 0.09 to 0.02 mg/mL of crude plant extracts. At subinhibitory concentrations, DVA significantly reduced Arg-gingipain (24%) and Lys-gingipain (53%) production by P. gingivalis (P ≤ 0.01). Conclusions. These results suggest that DVA has the potential to be used to control oral infections including dental caries and periodontal diseases. PMID:24223061

  5. Pelvic inflammatory disease due to Streptococcus pneumoniae: a usual pathogen at an unusual place.

    PubMed

    Lemoyne, S; Van Leemput, J; Smet, D; Desmedt, E; Devos, H; Van Schaeren, J; Jeurissen, A

    2008-01-01

    We report three cases of pelvic inflammatory disease (PID) due to Streptococcus pneumoniae in previously healthy young women. S. pneumoniae frequently causes bacteremia, meningitis and respiratory infections, but it very rarely infects the genital tract. All our patients presented with an acute onset of severe abdominal pain and had an intrauterine device (IUD) present. No abnormal sexual behavior was noticed. Although the relation between PID due to S. pneumoniae and the use of an IUD has been a topic for discussions, culture of IUD in all our patients and blood culture in 2 of 3 of our patients revealed S. pneumoniae. All patients recovered well with intravenous antibiotic treatment and removal of the IUD. PMID:19170357

  6. Antibacterial effect of water-soluble chitosan on representative dental pathogens Streptococcus mutans and Lactobacilli brevis

    PubMed Central

    CHEN, Chih-YU; CHUNG, Ying-CHIEN

    2012-01-01

    Dental caries is still a major oral health problem in most industrialized countries. The development of dental caries primarily involves Lactobacilli spp. and Streptococcus mutans. Although antibacterial ingredients are used against oral bacteria to reduce dental caries, some reports that show partial antibacterial ingredients could result in side effects. Objectives The main objective is to test the antibacterial effect of water-soluble chitosan while the evaluation of the mouthwash appears as a secondary aim. Material and Methods The chitosan was obtained from the Application Chemistry Company (Taiwan). The authors investigated the antibacterial effects of water-soluble chitosan against oral bacteria at different temperatures (25-37ºC) and pH values (pH 5-8), and evaluated the antibacterial activities of a self-made water-soluble chitosan-containing mouthwash by in vitro and in vivo experiments, and analyzed the acute toxicity of the mouthwashes. The acute toxicity was analyzed with the pollen tube growth (PTG) test. The growth inhibition values against the logarithmic scale of the test concentrations produced a concentrationresponse curve. The IC50 value was calculated by interpolation from the data. Results The effect of the pH variation (5-8) on the antibacterial activity of water-soluble chitosan against tested oral bacteria was not significant. The maximal antibacterial activity of water-soluble chitosan occurred at 37ºC. The minimum bactericidal concentration (MBC) of water-soluble chitosan on Streptococcus mutans and Lactobacilli brevis were 400 µg/mL and 500 µg/mL, respectively. Only 5 s of contact between water-soluble chitosan and oral bacteria attained at least 99.60% antibacterial activity at a concentration of 500 µg/mL. The water-soluble chitosan-containin g mouthwash significantly demonstrated antibacterial activity that was similar to that of commercial mouthwashes (>99.91%) in both in vitro and in vivo experiments. In addition, the alcohol

  7. Protein preparation, crystallization and preliminary X-ray crystallographic analysis of SMU.961 protein from the caries pathogen Streptococcus mutans

    SciTech Connect

    Gao, Xiong-Zhuo; Li, Lan-Fen; Su, Xiao-Dong; Zhao, XiaoJun; Liang, Yu-He

    2007-10-01

    The SMU.961 protein from S. mutans was crystallized and preliminary characterization of the crystals, which diffracted to 2.9 Å resolution, shows them to belong to space group C2. The smu.961 gene encodes a putative protein of 183 residues in Streptococcus mutans, a major pathogen in human dental caries. The gene was cloned into expression vector pET28a and expressed in a substantial quantity in Escherichia coli strain BL21 (DE3) with a His tag at its N-terminus. The recombinant protein SMU.961 was purified to homogeneity in a two-step procedure consisting of Ni{sup 2+}-chelating and size-exclusion chromatography. Crystals suitable for X-ray diffraction were obtained by the hanging-drop vapour-diffusion method and diffracted to 2.9 Å resolution at beamline I911-3, MAX-II-lab, Sweden. The crystal belonged to space group C2, with unit-cell parameters a = 98.62, b = 73.73, c = 184.73 Å, β = 98.82°.

  8. Sequential necrotizing fasciitis caused by the monomicrobial pathogens Streptococcus equisimilis and extended-spectrum beta-lactamase-producing Escherichia coli.

    PubMed

    Endo, Akiko; Matsuoka, Ryosuke; Mizuno, Yasushi; Doi, Asako; Nishioka, Hiroaki

    2016-08-01

    Necrotizing fasciitis is a rapidly progressing bacterial infection of the superficial fascia and subcutaneous tissue that is associated with a high mortality rate and is caused by a single species of bacteria or polymicrobial organisms. Escherichia coli is rarely isolated from patients with monomicrobial disease. Further, there are few reports of extended-spectrum beta-lactamase (ESBL)-producing E. coli associated with necrotizing fasciitis. We report here our treatment of an 85-year-old man who was admitted because of necrotizing fasciitis of his right thigh. Streptococcus equisimilis was detected as a monomicrobial pathogen, and the infection was cured by amputation of the patient's right leg and the administration of antibiotics. However, 5 days after discontinuing antibiotic therapy, he developed necrotizing fasciitis on his right upper limb and died. ESBL-producing E. coli was the only bacterial species isolated from blood and skin cultures. This case demonstrates that ESBL-producing E. coli can cause monomicrobial necrotizing fasciitis, particularly during hospitalization and that a different bacterial species can cause disease shortly after a previous episode. PMID:26912298

  9. Cloning, characterization and anion inhibition study of a β-class carbonic anhydrase from the caries producing pathogen Streptococcus mutans.

    PubMed

    Dedeoglu, Nurcan; De Luca, Viviana; Isik, Semra; Yildirim, Hatice; Kockar, Feray; Capasso, Clemente; Supuran, Claudiu T

    2015-07-01

    The oral pathogenic bacterium involved in human dental caries formation Streptococcus mutans, encodes for two carbonic anhydrase (CA, EC 4.2.1.1) one belonging to the α- and the other one to the β-class. This last enzyme (SmuCA) has been cloned, characterized and investigated for its inhibition profile with a major class of CA inhibitors, the inorganic anions. Here we show that SmuCA has a good catalytic activity for the CO2 hydration reaction, with kcat 4.2×10(5)s(-1) and kcat/Km of 5.8×10(7)M(-1)×s(-1), being inhibited by cyanate, carbonate, stannate, divannadate and diethyldithiocarbamate in the submillimolar range (KIs of 0.30-0.64mM) and more efficiently by sulfamide, sulfamate, phenylboronic acid and phenylarsonic acid (KIs of 15-46μM). The anion inhibition profile of the S. mutans enzyme is very different from other α- and β-CAs investigated earlier. Identification of effective inhibitors of this new enzyme may lead to pharmacological tools useful for understanding the role of S. mutans CAs in dental caries formation, and eventually the development of pharmacological agents with a new mechanism of antibacterial action. PMID:26014482

  10. Sulfonamide inhibition study of the β-class carbonic anhydrase from the caries producing pathogen Streptococcus mutans.

    PubMed

    Dedeoglu, Nurcan; DeLuca, Viviana; Isik, Semra; Yildirim, Hatice; Kockar, Feray; Capasso, Clemente; Supuran, Claudiu T

    2015-06-01

    Streptococcus mutans, the oral pathogenic bacterium provoking dental caries formation, encodes for a β-class carbonic anhydrase (CA, EC 4.2.1.1), SmuCA. This enzyme was cloned, characterized and investigated for its inhibition profile with the major class of CA inhibitors, the primary sulfonamides. SmuCA has a good catalytic activity for the CO2 hydration reaction, with a kcat of 4.2×10(5) s(-1) and kcat/Km of 5.8×10(7) M(-1)×s(-1), and is efficiently inhibited by most sulfonamides (KIs of 246 nM-13.5 μM). The best SmuCA inhibitors were bromosulfanilamide, deacetylated acetazolamide, 4-hydroxymethylbenzenesulfonamide, a pyrimidine-substituted sulfanilamide derivative, aminobenzolamide and compounds structurally similar to it, as well as acetazolamide, methazolamide, indisulam and valdecoxib. These compounds showed inhibition constants ranging between 246 and 468 nM. Identification of effective inhibitors of this enzyme may lead to pharmacological tools useful for understanding the role of S. mutans CAs in dental caries formation, and eventually the development of pharmacological agents with a new mechanism of antibacterial action. PMID:25913199

  11. Multicentric study in five African countries of antibiotic susceptibility for three main pathogens: Streptococcus pneumoniae, Staphylococcus aureus, and Pseudomonas aeruginosa.

    PubMed

    Zerouali, Khalid; Ramdani-Bouguessa, Nadjia; Boye, Cheikh; Hammami, Adnane

    2016-08-01

    Antibiotic resistance is a growing clinical and epidemiological problem. We report on the antibiotic susceptibility of three pathogens isolated from patients in Algeria, Egypt, Morocco, Senegal, and Tunisia during 2010-2011. In total, 218 Streptococcus pneumoniae, 428 Staphylococcus aureus, and 414 Pseudomonas aeruginosa strains were collected. S. pneumoniae resistance was noted against penicillin (30.2%), erythromycin (27.4%), cefpodoxime (19.1%), amoxicillin (12.0%), cefotaxime (7.4%), and levofloxacin (3.2%). All the strains were teicoplanin susceptible. Staphylococcus aureus methicillin resistance differed between countries, from 5.0% in Senegal to 62.7% in Egypt. Levofloxacin resistance was low in all countries, and the highest rate (in Egypt) was still only 13.6% for intermediate and resistant strains combined. Most strains were susceptible to fosfomycin (99.3%) and pristinamycin (94.2%). P. aeruginosa resistance was found against levofloxacin (30.4%), ciprofloxacin (29.9%), tobramycin (19.7%), ceftazidime (19.2%), and imipenem (17.9%), but not colistin. Antibiotic susceptibility varied widely between countries, with resistance typically most prevalent in Egypt. PMID:25363146

  12. Assessing the Metabolic Diversity of Streptococcus from a Protein Domain Point of View

    PubMed Central

    Koehorst, Jasper J.; Martins dos Santos, Vitor A. P.; Schaap, Peter J.

    2015-01-01

    Understanding the diversity and robustness of the metabolism of bacteria is fundamental for understanding how bacteria evolve and adapt to different environments. In this study, we characterised 121 Streptococcus strains and studied metabolic diversity from a protein domain perspective. Metabolic pathways were described in terms of the promiscuity of domains participating in metabolic pathways that were inferred to be functional. Promiscuity was defined by adapting existing measures based on domain abundance and versatility. The approach proved to be successful in capturing bacterial metabolic flexibility and species diversity, indicating that it can be described in terms of reuse and sharing functional domains in different proteins involved in metabolic activity. Additionally, we showed striking differences among metabolic organisation of the pathogenic serotype 2 Streptococcus suis and other strains. PMID:26366735

  13. Development of primer sets for loop-mediated isothermal amplification that enables rapid and specific detection of Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae are the three main pathogens causing bovine mastitis, with great losses to the dairy industry. Rapid and specific loop-mediated isothermal amplification methods (LAMP) for identification and differentiation of these three ...

  14. Identification and characterization of a surface protein-releasing activity in Streptococcus mutans and other pathogenic streptococci.

    PubMed Central

    Lee, S F

    1992-01-01

    Surface proteins of Streptococcus mutans have been reported to be released into the culture filtrate at concentrations that vary with the growth conditions. The reason for this is not clear. The present study attempts to investigate the mechanism of the protein release. The results showed that whole cells and raffinose-stabilized protoplasts of S. mutans NG8, when incubated in buffers, were capable of releasing their surface proteins in a pH-dependent manner with optimal release at pH 5 to 6. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed that the released proteins were very complex. Two proteins, adhesin P1, which has been previously shown to interact with a human salivary agglutinin, and glucosyltransferase have been identified among the released proteins. The release of adhesin P1 and other proteins was found to be inhibited by heat, Cu2+,Zn2+, and thiol-blocking reagents. The inhibition by heat and Cu2+ was irreversible, whereas that by the thiol-blocking reagents was reversible. EDTA, phenylmethylsulfonyl fluoride, and N-p-tosyl-L-lysyl-chloromethyl ketone had no effect on the release of P1, indicating that the release was probably not due to proteolytic activity. Adhesin P1 from Cu(2+)-inactivated S. mutans NG8 protoplasts could be released by mixing with fresh whole cells and protoplasts, but not the culture filtrate, of a P1-negative mutant of NG8, suggesting that the enzyme is located on the cell surface. This P1-releasing activity was also detected in two other strains of S. mutans and one strain each of S. gordonii, S. agalactiae, S. pneumoniae, and S. pyogenes. The biological role(s) of this enzyme activity remains to be determined. However, owing to its ability to release virulent surface proteins from the cell, it may play an important role in cell surface modulation among the pathogenic streptococci. Images PMID:1398915

  15. Molecular characterization and virulence gene profiling of pathogenic Streptococcus agalactiae populations from tilapia (Oreochromis sp.) farms in Thailand.

    PubMed

    Kayansamruaj, Pattanapon; Pirarat, Nopadon; Katagiri, Takayuki; Hirono, Ikuo; Rodkhum, Channarong

    2014-05-19

    Streptococcus spp. were recovered from diseased tilapia in Thailand during 2009-2010 (n = 33), and were also continually collected from environmental samples (sediment and water) from tilapia farms for 9 months in 2011 (n = 25). The relative percent recovery of streptococci from environmental samples was 13-67%. All streptococcal isolates were identified as S. agalactiae (group B streptococci [GBS]) by a species-specific polymerase chain reaction. In molecular characterization assays, 4 genotypic categories comprised of 1) molecular serotypes, 2) the infB allele, 3) virulence gene profiling patterns (cylE, hylB, scpB, lmb, cspA, dltA, fbsA, fbsB, bibA, gap, and pili backbone-encoded genes), and 4) randomly amplified polymorphic DNA (RAPD) fingerprinting patterns, were used to describe the genotypic diversity of the GBS isolates. There was only 1 isolate identified as molecular serotype III, while the others were serotype Ia. Most GBS serotype Ia isolates had an identical infB allele and virulence gene profiling patterns, but a large diversity was established by RAPD analysis with diversity tending to be geographically dependent. Experimental infection of Nile tilapia (Oreochromis niloticus) revealed that the GBS serotype III isolate was nonpathogenic in the fish, while all 5 serotype Ia isolates (3 fish and 2 environmental isolates) were pathogenic, with a median lethal dose of 6.25-7.56 log10 colony-forming units. In conclusion, GBS isolates from tilapia farms in Thailand showed a large genetic diversity, which was associated with the geographical origins of the bacteria. PMID:24842288

  16. Contribution of the Interaction of Streptococcus mutans Serotype k Strains with Fibrinogen to the Pathogenicity of Infective Endocarditis

    PubMed Central

    Nomura, Ryota; Otsugu, Masatoshi; Naka, Shuhei; Teramoto, Noboru; Kojima, Ayuchi; Muranaka, Yoshinori; Matsumoto-Nakano, Michiyo; Ooshima, Takashi

    2014-01-01

    Streptococcus mutans, a pathogen responsible for dental caries, is occasionally isolated from the blood of patients with bacteremia and infective endocarditis (IE). Our previous study demonstrated that serotype k-specific bacterial DNA is frequently detected in S. mutans-positive heart valve specimens extirpated from IE patients. However, the reason for this frequent detection remains unknown. In the present study, we analyzed the virulence of IE from S. mutans strains, focusing on the characterization of serotype k strains, most of which are positive for the 120-kDa cell surface collagen-binding protein Cbm and negative for the 190-kDa protein antigen (PA) known as SpaP, P1, antigen I/II, and other designations. Fibrinogen-binding assays were performed with 85 clinical strains classified by Cbm and PA expression levels. The Cbm+/PA− group strains had significantly higher fibrinogen-binding rates than the other groups. Analysis of platelet aggregation revealed that SA31, a Cbm+/PA− strain, induced an increased level of aggregation in the presence of fibrinogen, while negligible aggregation was induced by the Cbm-defective isogenic mutant SA31CBD. A rat IE model with an artificial impairment of the aortic valve created using a catheter showed that extirpated heart valves in the SA31 group displayed a prominent vegetation mass not seen in those in the SA31CBD group. These findings could explain why Cbm+/PA− strains are highly virulent and are related to the development of IE, and the findings could also explain the frequent detection of serotype k DNA in S. mutans-positive heart valve clinical specimens. PMID:25287921

  17. Identification and characterization of a surface protein-releasing activity in Streptococcus mutans and other pathogenic streptococci.

    PubMed

    Lee, S F

    1992-10-01

    Surface proteins of Streptococcus mutans have been reported to be released into the culture filtrate at concentrations that vary with the growth conditions. The reason for this is not clear. The present study attempts to investigate the mechanism of the protein release. The results showed that whole cells and raffinose-stabilized protoplasts of S. mutans NG8, when incubated in buffers, were capable of releasing their surface proteins in a pH-dependent manner with optimal release at pH 5 to 6. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed that the released proteins were very complex. Two proteins, adhesin P1, which has been previously shown to interact with a human salivary agglutinin, and glucosyltransferase have been identified among the released proteins. The release of adhesin P1 and other proteins was found to be inhibited by heat, Cu2+,Zn2+, and thiol-blocking reagents. The inhibition by heat and Cu2+ was irreversible, whereas that by the thiol-blocking reagents was reversible. EDTA, phenylmethylsulfonyl fluoride, and N-p-tosyl-L-lysyl-chloromethyl ketone had no effect on the release of P1, indicating that the release was probably not due to proteolytic activity. Adhesin P1 from Cu(2+)-inactivated S. mutans NG8 protoplasts could be released by mixing with fresh whole cells and protoplasts, but not the culture filtrate, of a P1-negative mutant of NG8, suggesting that the enzyme is located on the cell surface. This P1-releasing activity was also detected in two other strains of S. mutans and one strain each of S. gordonii, S. agalactiae, S. pneumoniae, and S. pyogenes. The biological role(s) of this enzyme activity remains to be determined. However, owing to its ability to release virulent surface proteins from the cell, it may play an important role in cell surface modulation among the pathogenic streptococci. PMID:1398915

  18. Streptococcus pyogenes SpyCEP Influences Host-Pathogen Interactions during Infection in a Murine Air Pouch Model

    PubMed Central

    Chiappini, Nico; Seubert, Anja; Telford, John L.; Grandi, Guido; Serruto, Davide; Margarit, Immaculada; Janulczyk, Robert

    2012-01-01

    Streptococcus pyogenes is a major human pathogen worldwide, responsible for both local and systemic infections. These bacteria express the subtilisin-like protease SpyCEP which cleaves human IL-8 and related chemokines. We show that localization of SpyCEP is growth-phase and strain dependent. Significant shedding was observed only in a strain naturally overexpressing SpyCEP, and shedding was not dependent on SpyCEP autoproteolytic activity. Surface-bound SpyCEP in two different strains was capable of cleaving IL-8. To investigate SpyCEP action in vivo, we adapted the mouse air pouch model of infection for parallel quantification of bacterial growth, host immune cell recruitment and chemokine levels in situ. In response to infection, the predominant cells recruited were neutrophils, monocytes and eosinophils. Concomitantly, the chemokines KC, LIX, and MIP-2 in situ were drastically increased in mice infected with the SpyCEP knockout strain, and growth of this mutant strain was reduced compared to the wild type. SpyCEP has been described as a potential vaccine candidate against S. pyogenes, and we showed that surface-associated SpyCEP was recognized by specific antibodies. In vitro, such antibodies also counteracted the inhibitory effects of SpyCEP on chemokine mediated PMN recruitment. Thus, α-SpyCEP antibodies may benefit the host both directly by enabling opsonophagocytosis, and indirectly, by neutralizing an important virulence factor. The animal model we employed shows promise for broad application in the study of bacterial pathogenesis. PMID:22848376

  19. First Isolation of Streptococcus halichoeri and Streptococcus phocae from a Steller Sea Lion (Eumetopias jubatus) in South Korea.

    PubMed

    Lee, Kichan; Kim, Ji-Yeon; Jung, Suk Chan; Lee, Hee-Soo; Her, Moon; Chae, Chanhee

    2016-01-01

    Streptococcus species are emerging potential pathogens in marine mammals. We report the isolation and identification of Streptococcus halichoeri and Streptococcus phocae in a Steller sea lion (Eumetopias jubatus) in South Korea. PMID:26555114

  20. In Vitro Bactericidal and Bacteriolytic Activity of Ceragenin CSA-13 against Planktonic Cultures and Biofilms of Streptococcus pneumoniae and Other Pathogenic Streptococci

    PubMed Central

    Menéndez, Margarita; García, Ernesto

    2014-01-01

    Ceragenin CSA-13, a cationic steroid, is here reported to show a concentration-dependent bactericidal/bacteriolytic activity against pathogenic streptococci, including multidrug-resistant Streptococcus pneumoniae. The autolysis promoted by CSA-13 in pneumococcal cultures appears to be due to the triggering of the major S. pneumoniae autolysin LytA, an N-acetylmuramoyl-L-alanine amidase. CSA-13 also disintegrated pneumococcal biofilms in a very efficient manner, although at concentrations slightly higher than those required for bactericidal activity on planktonic bacteria. CSA-13 has little hemolytic activity which should allow testing its antibacterial efficacy in animal models. PMID:25006964

  1. [Primary human demodicosis. A disease sui generis].

    PubMed

    Hsu, C-K; Zink, A; Wei, K-J; Dzika, E; Plewig, G; Chen, W

    2015-03-01

    Human Demodex mites (Demodex folliculorum and Demodex brevis) are unique in that they are an obligate human ectoparasite that can inhabit the pilosebaceous unit lifelong without causing obvious host immune response in most cases. The mode of symbiosis between humans and human Demodex mites is unclear, while the pathogenicity of human Demodex mites in many inflammatory skin diseases is now better understood. Primary human demodicosis is a skin disease sui generis not associated with local or systemic immunosuppression. Diagnosis is often underestimated and differentiation from folliculitis, papulopustular rosacea and perioral dermatitis is not always straightforward. Dependent on the morphology and degree of inflammation, the clinical manifestations can be classified into spinulate, papulopustular, nodulocystic, crustic and fulminant demodicosis. Therapy success can be achieved only with acaricides/arachidicides. The effective doses, optimal regimen and antimicrobial resistance remain to be determined. PMID:25744530

  2. Evolution of the core and pan-genome of Streptococcus: positive selection, recombination, and genome composition

    PubMed Central

    Lefébure, Tristan; Stanhope, Michael J

    2007-01-01

    Background The genus Streptococcus is one of the most diverse and important human and agricultural pathogens. This study employs comparative evolutionary analyses of 26 Streptococcus genomes to yield an improved understanding of the relative roles of recombination and positive selection in pathogen adaptation to their hosts. Results Streptococcus genomes exhibit extreme levels of evolutionary plasticity, with high levels of gene gain and loss during species and strain evolution. S. agalactiae has a large pan-genome, with little recombination in its core-genome, while S. pyogenes has a smaller pan-genome and much more recombination of its core-genome, perhaps reflecting the greater habitat, and gene pool, diversity for S. agalactiae compared to S. pyogenes. Core-genome recombination was evident in all lineages (18% to 37% of the core-genome judged to be recombinant), while positive selection was mainly observed during species differentiation (from 11% to 34% of the core-genome). Positive selection pressure was unevenly distributed across lineages and biochemical main role categories. S. suis was the lineage with the greatest level of positive selection pressure, the largest number of unique loci selected, and the largest amount of gene gain and loss. Conclusion Recombination is an important evolutionary force in shaping Streptococcus genomes, not only in the acquisition of significant portions of the genome as lineage specific loci, but also in facilitating rapid evolution of the core-genome. Positive selection, although undoubtedly a slower process, has nonetheless played an important role in adaptation of the core-genome of different Streptococcus species to different hosts. PMID:17475002

  3. Porcine retinal cell line VIDO R1 and Chlamydia suis to modelize ocular chlamydiosis.

    PubMed

    Käser, Tobias; Cnudde, Thomas; Hamonic, Glenn; Rieder, Meghanne; Pasternak, J Alex; Lai, Ken; Tikoo, Suresh K; Wilson, Heather L; Meurens, François

    2015-08-15

    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. PMID:26103808

  4. In vitro antibacterial activities of ethanol extract of iranian propolis (EEIP) against fish pathogenic bacteria (Aeromonas hydrophila, Yersinia ruckeri & Streptococcus iniae)

    PubMed Central

    Tukmechi, Amir; Ownagh, Abdolghaffar; Mohebbat, Ali

    2010-01-01

    The “in vitro” antibacterial activity of ethanol extract of propolis (EEIP) from Urmia, Iran was investigated against three prevalent species of fish bacterial pathogens including: Aeromonas hydrophila LMG 3770, Yersinia ruckeri LMG 3279 and Streptococcus iniae LMG 14520. In this study two standard susceptibility testing techniques (Micro-broth dilution method and Agar-well diffusion method) were used to evaluation of the antibacterial activity of EEIP against the mentioned micro-organisms. Also the chemical composition of propolis was determined by the method of Gas chromatography-mass spectrometry (GC-MS). Twenty-six compounds were identified by gas chromatography–mass spectrometry analysis. Results showed Chemical composition of EEIP contained significant amounts of flavonoids, Sesquiterpenes – mainly Eudesmol and Caryophyllene oxide - aromatic acid, and low amounts of aldehydes and triterpens. Furthermore the ethanol extract of propolis inhibited the growth of all examined micro-organisms with the highest antimicrobial activity against Gram-positive bacteria Streptococcus iniae. Ethanol did not influence the antimicrobial effect of EEIP. These antibacterial properties would warrant further studies on the clinical applications of propolis in aquaculture field. PMID:24031591

  5. Natural variation in the promoter of the gene encoding the Mga regulator alters host-pathogen interactions in group a Streptococcus carrier strains.

    PubMed

    Flores, Anthony R; Olsen, Randall J; Wunsche, Andrea; Kumaraswami, Muthiah; Shelburne, Samuel A; Carroll, Ronan K; Musser, James M

    2013-11-01

    Humans commonly carry pathogenic bacteria asymptomatically, but the molecular factors underlying microbial asymptomatic carriage are poorly understood. We previously reported that two epidemiologically unassociated serotype M3 group A Streptococcus (GAS) carrier strains had an identical 12-bp deletion in the promoter of the gene encoding Mga, a global positive gene regulator. Herein, we report on studies designed to test the hypothesis that the identified 12-bp deletion in the mga promoter alters GAS virulence, thereby potentially contributing to the asymptomatic carrier phenotype. Using allelic exchange, we introduced the variant promoter into a serotype M3 invasive strain and the wild-type promoter into an asymptomatic carrier strain. Compared to strains with the wild-type mga promoter, we discovered that strains containing the promoter with the 12-bp deletion produced significantly fewer mga and Mga-regulated gene transcripts. Consistent with decreased mga transcripts, strains containing the variant mga promoter were also significantly less virulent in in vivo and ex vivo models of GAS disease. Further, we provide evidence that the pleiotropic regulator protein CodY binds to the mga promoter and that the 12-bp deletion in the mga promoter reduces CodY-mediated mga transcription. We conclude that the naturally occurring 12-bp deletion in the mga promoter significantly alters the pathogen-host interaction of these asymptomatic carrier strains. Our findings provide new insight into the molecular basis of the carrier state of an important human pathogen. PMID:23980109

  6. Natural Variation in the Promoter of the Gene Encoding the Mga Regulator Alters Host-Pathogen Interactions in Group A Streptococcus Carrier Strains

    PubMed Central

    Flores, Anthony R.; Olsen, Randall J.; Wunsche, Andrea; Kumaraswami, Muthiah; Shelburne, Samuel A.; Carroll, Ronan K.

    2013-01-01

    Humans commonly carry pathogenic bacteria asymptomatically, but the molecular factors underlying microbial asymptomatic carriage are poorly understood. We previously reported that two epidemiologically unassociated serotype M3 group A Streptococcus (GAS) carrier strains had an identical 12-bp deletion in the promoter of the gene encoding Mga, a global positive gene regulator. Herein, we report on studies designed to test the hypothesis that the identified 12-bp deletion in the mga promoter alters GAS virulence, thereby potentially contributing to the asymptomatic carrier phenotype. Using allelic exchange, we introduced the variant promoter into a serotype M3 invasive strain and the wild-type promoter into an asymptomatic carrier strain. Compared to strains with the wild-type mga promoter, we discovered that strains containing the promoter with the 12-bp deletion produced significantly fewer mga and Mga-regulated gene transcripts. Consistent with decreased mga transcripts, strains containing the variant mga promoter were also significantly less virulent in in vivo and ex vivo models of GAS disease. Further, we provide evidence that the pleiotropic regulator protein CodY binds to the mga promoter and that the 12-bp deletion in the mga promoter reduces CodY-mediated mga transcription. We conclude that the naturally occurring 12-bp deletion in the mga promoter significantly alters the pathogen-host interaction of these asymptomatic carrier strains. Our findings provide new insight into the molecular basis of the carrier state of an important human pathogen. PMID:23980109

  7. Effects of the ERES pathogenicity region regulator Ralp3 on Streptococcus pyogenes serotype M49 virulence factor expression.

    PubMed

    Siemens, Nikolai; Fiedler, Tomas; Normann, Jana; Klein, Johannes; Münch, Richard; Patenge, Nadja; Kreikemeyer, Bernd

    2012-07-01

    Streptococcus pyogenes (group A streptococcus [GAS]) is a highly virulent Gram-positive bacterium. For successful infection, GAS expresses many virulence factors, which are clustered together with transcriptional regulators in distinct genomic regions. Ralp3 is a central regulator of the ERES region. In this study, we investigated the role of Ralp3 in GAS M49 pathogenesis. The inactivation of Ralp3 resulted in reduced attachment to and internalization into human keratinocytes. The Δralp3 mutant failed to survive in human blood and serum, and the hyaluronic acid capsule was slightly decreased. In addition, the mutant showed a lower binding capacity to human plasminogen, and the SpeB activity was significantly decreased. Complementation of the Δralp3 mutant restored the wild-type phenotype. The transcriptome and quantitative reverse transcription-PCR analysis of the serotype M49 GAS strain and its isogenic Δralp3 mutant identified 16 genes as upregulated, and 43 genes were found to be downregulated. Among the downregulated genes, there were open reading frames encoding proteins involved in metabolism (e.g., both lac operons and the fru operon), genes encoding lantibiotics (e.g., the putative salivaricin operon), and ORFs encoding virulence factors (such as the whole Mga core regulon and further genes under Mga control). In summary, the ERES region regulator Ralp3 is an important serotype-specific transcriptional regulator for virulence and metabolic control. PMID:22544273

  8. A Genome-Wide Profiling Strategy as an Aid for Searching Unique Identification Biomarkers for Streptococcus.

    PubMed

    Kalia, Vipin Chandra; Kumar, Ravi; Kumar, Prasun; Koul, Shikha

    2016-03-01

    The use of rrs (16S rRNA) gene is widely regarded as the "gold standard" for identifying bacteria and determining their phylogenetic relationships. Nevertheless, multiple copies of this gene in a genome is likely to give an overestimation of the bacterial diversity. In each of the 50 Streptococcus genomes (16 species, 50 strains), 4-7 copies of rrs are present. The nucleotide sequences of these rrs genes show high similarity within and among genomes, which did not allow unambiguous identification. A genome-wide search revealed the presence of 27 gene sequences common to all the Streptococcus species. Digestion of these 27 gene sequences with 10 type II restriction endonucleases (REs) showed that unique RE digestion in purH gene is sufficient for clear cut identification of 30 genomes belonging to 16 species. Additional gene-RE combinations allowed identification of another 15 strains belonging to S. pneumoniae, S. pyogenes, and S. suis. For the rest 5 strains, a combination of 2 genes was required for identifying them. The proposed strategy is likely to prove helpful in proper detection of pathogens like Streptococcus. PMID:26843696

  9. Prophage-mediated modulation of interaction of Streptococcus thermophilus J34 with human intestinal epithelial cells and its competition against human pathogens.

    PubMed

    Guigas, C; Faulhaber, K; Duerbeck, D; Neve, H; Heller, K J

    2016-01-01

    The human intestinal microbiota plays an important role in human health. While adhesion to gastrointestinal mucosa is a prerequisite for colonisation, inhibition of adhesion is a property which may prevent or reduce infections by food borne pathogens. Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus represent the two lactic bacteria constituting the yoghurt culture. These starter cultures have been claimed to be probiotic. In our study we compared two S. thermophilus strains (i.e. lysogenic strain J34 and corresponding non-lysogenic [prophage-cured] strain J34-6), with respect to (1) their in vitro adhesion properties to HT29 cells and (2) their cell surface hydrophobicities. Effects of the two strains on inhibition of adhesion of the pathogens Listeria monocytogenes Scott A, Staphylococcus aureus 6732 and Salmonella enteritidis S489 were studied in vitro with HT29 cell cultures. Lysogenic strain J34 was shown to be considerably more effective than the non-lysogenic derivative strain J34-6. PMID:26689226

  10. Brucella suis vaccine strain S2-infected immortalized caprine endometrial epithelial cell lines induce non-apoptotic ER-stress.

    PubMed

    Wang, Xiangguo; Lin, Pengfei; Yin, Yanlong; Zhou, Jinhua; Lei, Lanjie; Zhou, Xudong; Jin, Yaping; Wang, Aihua

    2015-05-01

    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. PMID:25633898

  11. Complete genome sequence of Mycoplasma suis and insights into its biology and adaption to an erythrocyte niche.

    PubMed

    Guimaraes, Ana M S; Santos, Andrea P; SanMiguel, Phillip; Walter, Thomas; Timenetsky, Jorge; Messick, Joanne B

    2011-01-01

    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

  12. A novel superantigen isolated from pathogenic strains of Streptococcus pyogenes with aminoterminal homology to staphylococcal enterotoxins B and C.

    PubMed Central

    Mollick, J A; Miller, G G; Musser, J M; Cook, R G; Grossman, D; Rich, R R

    1993-01-01

    Streptococcus pyogenes (group A Streptococcus) has re-emerged in recent years as a cause of severe human disease. Because extracellular products are involved in streptococcal pathogenesis, we explored the possibility that a disease isolate expresses an uncharacterized superantigen. We screened culture supernatants for superantigen activity with a major histocompatibility complex class II-dependent T cell proliferation assay. Initial fractionation with red dye A chromatography indicated production of a class II-dependent T cell mitogen by a toxic shock-like syndrome (TSLS) strain. The amino terminus of the purified streptococcal superantigen was more homologous to the amino termini of staphylococcal enterotoxins B, C1, and C3 (SEB, SEC1, and SEC3), than to those of pyrogenic exotoxins A, B, C or other streptococcal toxins. The molecule, designated SSA, had the same pattern of class II isotype usage as SEB in T cell proliferation assays. However, it differed in its pattern of human T cell activation, as measured by quantitative polymerase chain reaction with V beta-specific primers. SSA activated human T cells that express V beta 1, 3, 15 with a minor increase of V beta 5.2-bearing cells, whereas SEB activated V beta 3, 12, 15, and 17-bearing T cells. Immunoblot analysis of 75 disease isolates from several localities detected SSA production only in group A streptococci, and found that SSA is apparently confined to only three clonal lineages as defined by multilocus enzyme electrophoresis typing. Isolates of one of these lineages, (electrophoretic type 2) are strongly associated with TSLS. The data identify SSA as a novel streptococcal superantigen that appears to be more related structurally to staphylococcal enterotoxins than to streptococcal exotoxins. Because abundant SSA production is apparently confined to only three streptococcal clonal lineages, the data also suggest that the SSA gene has only recently been acquired by S. pyogenes. Images PMID:8349810

  13. First report of molecular identification of Cystoisospora suis in piglets with lethal diarrhea in Japan.

    PubMed

    Matsubayashi, Makoto; Takayama, Hideko; Kusumoto, Masahiro; Murata, Misato; Uchiyama, Yuka; Kaji, Masaya; Sasai, Kazumi; Yamaguchi, Ryosaku; Shibahara, Tomoyuki

    2016-06-01

    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. PMID:27078667

  14. Effects of Helicobacter suis γ-glutamyl transpeptidase on lymphocytes: modulation by glutamine and glutathione supplementation and outer membrane vesicles as a putative delivery route of the enzyme.

    PubMed

    Zhang, Guangzhi; Ducatelle, Richard; Pasmans, Frank; D'Herde, Katharina; Huang, Liping; Smet, Annemieke; Haesebrouck, Freddy; Flahou, Bram

    2013-01-01

    Helicobacter (H.) suis colonizes the stomach of the majority of pigs as well as a minority of humans worldwide. Infection causes chronic inflammation in the stomach of the host, however without an effective clearance of the bacteria. Currently, no information is available about possible mechanisms H. suis utilizes to interfere with the host immune response. This study describes the effect on various lymphocytes of the γ-glutamyl transpeptidase (GGT) from H. suis. Compared to whole cell lysate from wild-type H. suis, lysate from a H. suis ggt mutant strain showed a decrease of the capacity to inhibit Jurkat T cell proliferation. Incubation of Jurkat T cells with recombinantly expressed H. suis GGT resulted in an impaired proliferation, and cell death was shown to be involved. A similar but more pronounced inhibitory effect was also seen on primary murine CD4(+) T cells, CD8(+) T cells, and CD19(+) B cells. Supplementation with known GGT substrates was able to modulate the observed effects. Glutamine restored normal proliferation of the cells, whereas supplementation with reduced glutathione strengthened the H. suis GGT-mediated inhibition of proliferation. H. suis GGT treatment abolished secretion of IL-4 and IL-17 by CD4(+) T cells, without affecting secretion of IFN-γ. Finally, H. suis outer membrane vesicles (OMV) were identified as a possible delivery route of H. suis GGT to lymphocytes residing in the deeper mucosal layers. Thus far, this study is the first to report that the effects on lymphocytes of this enzyme, not only important for H. suis metabolism but also for that of other Helicobacter species, depend on the degradation of two specific substrates: glutamine and reduced glutatione. This will provide new insights into the pathogenic mechanisms of H. suis infection in particular and infection with gastric helicobacters in general. PMID:24147103

  15. Effects of Helicobacter suis γ- Glutamyl Transpeptidase on Lymphocytes: Modulation by Glutamine and Glutathione Supplementation and Outer Membrane Vesicles as a Putative Delivery Route of the Enzyme

    PubMed Central

    Zhang, Guangzhi; Ducatelle, Richard; Pasmans, Frank; D’Herde, Katharina; Huang, Liping; Smet, Annemieke; Haesebrouck, Freddy; Flahou, Bram

    2013-01-01

    Helicobacter (H.) suis colonizes the stomach of the majority of pigs as well as a minority of humans worldwide. Infection causes chronic inflammation in the stomach of the host, however without an effective clearance of the bacteria. Currently, no information is available about possible mechanisms H. suis utilizes to interfere with the host immune response. This study describes the effect on various lymphocytes of the γ-glutamyl transpeptidase (GGT) from H. suis. Compared to whole cell lysate from wild-type H. suis, lysate from a H. suis ggt mutant strain showed a decrease of the capacity to inhibit Jurkat T cell proliferation. Incubation of Jurkat T cells with recombinantly expressed H. suis GGT resulted in an impaired proliferation, and cell death was shown to be involved. A similar but more pronounced inhibitory effect was also seen on primary murine CD4+ T cells, CD8+ T cells, and CD19+ B cells. Supplementation with known GGT substrates was able to modulate the observed effects. Glutamine restored normal proliferation of the cells, whereas supplementation with reduced glutathione strengthened the H. suis GGT-mediated inhibition of proliferation. H. suis GGT treatment abolished secretion of IL-4 and IL-17 by CD4+ T cells, without affecting secretion of IFN-γ. Finally, H. suis outer membrane vesicles (OMV) were identified as a possible delivery route of H. suis GGT to lymphocytes residing in the deeper mucosal layers. Thus far, this study is the first to report that the effects on lymphocytes of this enzyme, not only important for H. suis metabolism but also for that of other Helicobacter species, depend on the degradation of two specific substrates: glutamine and reduced glutatione. This will provide new insights into the pathogenic mechanisms of H. suis infection in particular and infection with gastric helicobacters in general. PMID:24147103

  16. Description of the Pathogenic Features of Streptococcus pyogenes Isolates from Invasive and Non-Invasive Diseases in Aichi, Japan.

    PubMed

    Matsumoto, Masakado; Yamada, Kazuhiro; Suzuki, Masahiro; Adachi, Hirokazu; Kobayashi, Shinichi; Yamashita, Teruo; Minagawa, Hiroko; Tatsuno, Ichiro; Hasegawa, Tadao

    2016-07-22

    We identified hypervirulent Streptococcus pyogenes in 27 and 420 isolates from patients with invasive and non-invasive diseases, respectively, in Aichi Prefecture, Japan, between 2003 and 2012, in an attempt to understand why the prevalence of streptococcal toxic shock syndrome (STSS) suddenly increased in this location during 2011. Hypervirulent strains belong to the emm1 genotype, with a mutation in the covR/S genes that regulate many other genes, encoding virulence determinants and resulting in the absence of the proteinase streptococcal exotoxin B and the production of virulence factors such as the superantigen streptococcal exotoxin A, the nuclease streptococcal DNase, the cytotoxin NAD-glycohydrolase, and the hemolysin streptolysin O. We found 1 strain from invasive disease and 1 from non-invasive disease with traits similar to those of hypervirulent strains, except that the sda1 gene was absent. We also found 1 non-emm1 strain with phenotypic and genetic traits identical to those of the emm1 hypervirulent strains except that it did not belong to emm1 genotype, from non-invasive diseases cases in 2011. These findings suggested that hypervirulent and hypervirulent-like strains from invasive and non-invasive disease cases could have at least partially contributed to the sudden increase in the number of patients with STSS in Aichi during 2011. PMID:26567838

  17. Preparation and evaluation of antimicrobial activity of nanosystems for the control of oral pathogens Streptococcus mutans and Candida albicans

    PubMed Central

    Pupe, Carolina Gonçalves; Villardi, Michele; Rodrigues, Carlos Rangel; Rocha, Helvécio Vinícius Antunes; Maia, Lucianne Cople; de Sousa, Valeria Pereira; Cabral, Lucio Mendes

    2011-01-01

    Background Diseases that affect the buccal cavity are a public health concern nowadays. Chlorhexidine and nystatin are the most commonly used drugs for the control of buccal affections. In the search for more effective antimicrobials, nanotechnology can be successfully used to improve the physical chemical properties of drugs whilst avoiding the undesirable side effects associated with its use. Herein described are studies using nystatin and chlorhexidine with sodium montmorillonite (MMTNa), and chlorhexidine with β-cyclodextrin and two derivatives methyl-β-cyclodextrin and hydroxypropyl-β-cyclodextrin in the development of antimicrobial nanosystems. Methods The nanosystems were prepared by kneading and solubilization followed by freeze-drying technique. The nanosystems were characterized by X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR). Nanosystem antimicrobial activity against Streptococcus mutans and Candida albicans strains was evaluated with inhibition halo analysis. Results The nanocarriers MMTNa and cyclodextrins showed good yields. XRPD, FTIR, and DSC analysis confirmed the proposed nanosystems formation and the suitability of the production methods. The nanosystems that showed best antimicrobial effect were chlorhexidine gluconate (CHX) and cyclodextrin inclusion complexes and CHX:MMTNa 60% cation exchange capacity – 24 hours. Conclusion The nanosystem formulations present higher stability for all chlorhexidine inclusion complexes compared with pure chlorhexidine. The nystatin nanosystems have the potential to mask the bitter taste, justifying subsequent in-vivo studies. For these reasons, further studies are being carried out to evaluate their application in professional formulations. PMID:22114490

  18. Spread of drug-resistant Streptococcus pneumoniae in Asian countries: Asian Network for Surveillance of Resistant Pathogens (ANSORP) Study.

    PubMed

    Song, J H; Lee, N Y; Ichiyama, S; Yoshida, R; Hirakata, Y; Fu, W; Chongthaleong, A; Aswapokee, N; Chiu, C H; Lalitha, M K; Thomas, K; Perera, J; Yee, T T; Jamal, F; Warsa, U C; Vinh, B X; Jacobs, M R; Appelbaum, P C; Pai, C H

    1999-06-01

    Antimicrobial susceptibility of 996 isolates of Streptococcus pneumoniae from clinical specimens was investigated in 11 Asian countries from September 1996 to June 1997. Korea had the greatest frequency of nonsusceptible strains to penicillin with 79.7%, followed by Japan (65.3%), Vietnam (60.8%), Thailand (57.9%), Sri Lanka (41.2%), Taiwan (38.7%), Singapore (23.1%), Indonesia (21.0%), China (9.8%), Malaysia (9.0%), and India (3.8%). Serotypes 23F and 19F were the most common. Pulsed-field gel electrophoresis (PFGE) of 154 isolates from Asian countries showed several major PFGE patterns. The serotype 23F Spanish clone shared the same PFGE pattern with strains from Korea, Japan, Singapore, Taiwan, Thailand, and Malaysia. Fingerprinting analysis of pbp1a, pbp2x, and pbp2b genes of 12 strains from six countries also showed identical fingerprints of penicillin-binding protein genes in most strains. These data suggest the possible introduction and spread of international epidemic clones into Asian countries and the increasing problems of pneumococcal drug resistance in Asian countries for the first time. PMID:10451154

  19. Streptococcus iniae vaccine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus iniae is among the most important emergent pathogens that affects many fish species worldwide, especially in warm-water regions. In marine and freshwater systems, this Gram-positive bacterium causes significant economic losses, estimated at hundreds of millions of dollars annually. Inf...

  20. Increasing of temperature induces pathogenicity of Streptococcus agalactiae and the up-regulation of inflammatory related genes in infected Nile tilapia (Oreochromis niloticus).

    PubMed

    Kayansamruaj, Pattanapon; Pirarat, Nopadon; Hirono, Ikuo; Rodkhum, Channarong

    2014-08-01

    Temperature strongly affects the health of aquatic poikilotherms. In Nile tilapia (Oreochromis niloticus), elevated water temperatures increase the severity of streptococcosis. Here we investigated the effects of temperature on the vulnerability and inflammatory response of Nile tilapia to Streptococcus agalactiae (Group B streptococci; GBS). At 35 and 28 °C, GBS took 4 and 7h, respectively to reach the log-phase and, when incubated with tilapia whole blood, experienced survival rates of 97% and 2%, respectively. The hemolysis activity of GBS grown at 35 °C was five times higher than that of GBS grown at 28 °C. GBS expressed cylE (β-hemolysin/cytolysin), cfb (CAMP factor) and PI-2b (pili-backbone) much more strongly at 35 °C than at 28 °C. Challenging Nile tilapia reared at 35 and 28 °C with GBS resulted in accumulated mortalities of about 85% and 45%, respectively. At 35 °C, infected tilapia exhibited tremendous inflammatory responses due to a dramatic up-regulation (30-40-fold) of inflammatory-related genes (cyclooxygenase-2, IL-1β and TNF-α) between 6 and 96 h-post infection. These results suggest that the increase of GBS pathogenicity to Nile tilapia induced by elevated temperature is associated with massive inflammatory responses, which may lead to acute mortality. PMID:24856132

  1. Antimicrobial susceptibility monitoring of respiratory tract pathogens isolated from diseased cattle and pigs across Europe: the VetPath study.

    PubMed

    de Jong, Anno; Thomas, Valérie; Simjee, Shabbir; Moyaert, Hilde; El Garch, Farid; Maher, Kirsty; Morrissey, Ian; Butty, Pascal; Klein, Ulrich; Marion, Hervé; Rigaut, Delphine; Vallé, Michel

    2014-08-01

    VetPath is an ongoing pan-European antibiotic susceptibility monitoring programme collecting pathogens from diseased antimicrobial non-treated cattle, pigs and poultry. In the current study, 1001 isolates from cattle and pig respiratory tract infections were tested for their antimicrobial susceptibilities. Non-replicate lung samples or nasopharyngeal/nasal swabs were collected from animals with acute clinical signs in 11 countries during 2002-2006. Pasteurella multocida and Mannheimia haemolytica from cattle and P. multocida, Actinobacillus pleuropneumoniae and Streptococcus suis from pigs were isolated by standard methods. S. suis was also isolated from meningitis cases. MICs of 16 antibiotics were assessed centrally by broth microdilution following CLSI recommendations. Results were interpreted using CLSI breakpoints where available. P. multocida (231) and M. haemolytica (138) isolates were all susceptible to amoxicillin/clavulanic acid, ceftiofur, enrofloxacin and trimethoprim/sulfamethoxazole. Resistance to florfenicol and spectinomycin was 0.4% and 3.5% in P. multocida, respectively, and absent in M. haemolytica isolates. Tetracycline resistance was 5.7% and 14.6% for P. multocida and M. haemolytica. In pigs, 230 P. multocida, 220 A. pleuropneumoniae and 182 S. suis isolates were recovered. Resistance to amoxicillin/clavulanic acid, ceftiofur, enrofloxacin, florfenicol, tiamulin and tilmicosin was absent or <1%. Trimethoprim/sulfamethoxazole resistance was 3-6% and tetracycline resistance varied from 14.7% in A. pleuropneumoniae to 81.8% in S. suis. In conclusion, low resistance to antibiotics with defined clinical breakpoints, except for tetracycline, was observed among the major respiratory tract pathogens recovered from cattle and pigs. Since for approximately half of the antibiotics in this panel no CLSI-defined breakpoints were available, setting of the missing veterinary breakpoints is important. PMID:24837878

  2. Immune responses and protection induced by Brucella suis S2 bacterial ghosts in mice.

    PubMed

    Liu, Jun; Li, Yi; Sun, Yang; Ji, Xue; Zhu, Lingwei; Guo, Xuejun; Zhou, Wei; Zhou, Bo; Liu, Shuang; Zhang, Ruian; Feng, Shuzhang

    2015-08-15

    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. PMID:26022514

  3. Autoinducer-2 of Streptococcus mitis as a Target Molecule to Inhibit Pathogenic Multi-Species Biofilm Formation In Vitro and in an Endotracheal Intubation Rat Model

    PubMed Central

    Wang, Zhengli; Xiang, Qingqing; Yang, Ting; Li, Luquan; Yang, Jingli; Li, Hongong; He, Yu; Zhang, Yunhui; Lu, Qi; Yu, Jialin

    2016-01-01

    Streptococcus mitis (S. mitis) and Pseudomonas aeruginosa (P. aeruginosa) are typically found in the upper respiratory tract of infants. We previously found that P. aeruginosa and S. mitis were two of the most common bacteria in biofilms on newborns’ endotracheal tubes (ETTs) and in their sputa and that S. mitis was able to produce autoinducer-2 (AI-2), whereas P. aeruginosa was not. Recently, we also found that exogenous AI-2 and S. mitis could influence the behaviors of P. aeruginosa. We hypothesized that S. mitis contributes to this interspecies interaction and that inhibition of AI-2 could result in inhibition of these effects. To test this hypothesis, we selected PAO1 as a representative model strain of P. aeruginosa and evaluated the effect of S. mitis as well as an AI-2 analog (D-ribose) on mono- and co-culture biofilms in both in vitro and in vivo models. In this context, S. mitis promoted PAO1 biofilm formation and pathogenicity. Dual-species (PAO1 and S. mitis) biofilms exhibited higher expression of quorum sensing genes than single-species (PAO1) biofilms did. Additionally, ETTs covered in dual-species biofilms increased the mortality rate and aggravated lung infection compared with ETTs covered in mono-species biofilms in an endotracheal intubation rat model, all of which was inhibited by D-ribose. Our results demonstrated that S. mitis AI-2 plays an important role in interspecies interactions with PAO1 and may be a target for inhibition of biofilm formation and infection in ventilator-associated pneumonia. PMID:26903968

  4. Nationwide survey of the development of drug-resistant pathogens in the pediatric field: drug sensitivity of Streptococcus pneumoniae in Japan.

    PubMed

    Sato, Yoshitake; Toyonaga, Yoshikiyo; Hanaki, Hideaki; Nonoyama, Masato; Oishi, Tomohiro; Sunakawa, Keisuke

    2009-12-01

    We evaluated the resistance to 20 different antibacterial agents of 362 clinically isolated strains of Streptococcus pneumoniae accumulated from October 2000 to July 2001 (phase 1) and of 332 different strains accumulated from January to June 2004 (phase 2), from institutions throughout Japan that participated in the surveys carried out by the Drug-Resistant Pathogen Surveillance Group in Pediatric Infectious Disease. In phase 1, the proportions of penicillin-sensitive S. pneumoniae (PSSP), penicillin-insensitive S. pneumoniae (PISP), and penicillin-resistant S. pneumoniae (PRSP) were 35.4%, 34.8%, and 29.8%, respectively, and the proportions were almost the same in phase 2: 33.1%, 37.0%, and 29.8%, respectively. Comparison of the MIC(90) values of the antibacterial agents for PRSP in phase 1 and phase 2 revealed that these values for cefditoren, cefpodoxime, cefdinir, faropenem, ceftriaxone, cefotaxime, meropenem, and vancomycin increased by twofold to fourfold during the 3 years between phase 1 and phase 2. However the MIC(90) of rokitamycin increased more than fourfold. The proportion of S. pneumoniae that were PISP + PRSP remained almost constant over the 3 years between phase 1 and phase 2. The background factors of patient age, previous administration of antibacterial agents, and attendance at a day nursery were examined; we found that in phase 1, the proportion of PISP + PRSP was significantly higher than that of PSSP in patients under 4 years old who had previously received antibacterial agents, but no significant differences were found in any of these background factors in the phase 2 survey. No significant difference was found in the proportions of penicillin-resistant bacteria according to whether or not the child had attended a day nursery. PMID:20012731

  5. Comparative supragenomic analyses among the pathogens Staphylococcus aureus, Streptococcus pneumoniae, and Haemophilus influenzae Using a modification of the finite supragenome model

    PubMed Central

    2011-01-01

    Background Staphylococcus aureus is associated with a spectrum of symbiotic relationships with its human host from carriage to sepsis and is frequently associated with nosocomial and community-acquired infections, thus the differential gene content among strains is of interest. Results We sequenced three clinical strains and combined these data with 13 publically available human isolates and one bovine strain for comparative genomic analyses. All genomes were annotated using RAST, and then their gene similarities and differences were delineated. Gene clustering yielded 3,155 orthologous gene clusters, of which 2,266 were core, 755 were distributed, and 134 were unique. Individual genomes contained between 2,524 and 2,648 genes. Gene-content comparisons among all possible S. aureus strain pairs (n = 136) revealed a mean difference of 296 genes and a maximum difference of 476 genes. We developed a revised version of our finite supragenome model to estimate the size of the S. aureus supragenome (3,221 genes, with 2,245 core genes), and compared it with those of Haemophilus influenzae and Streptococcus pneumoniae. There was excellent agreement between RAST's annotations and our CDS clustering procedure providing for high fidelity metabolomic subsystem analyses to extend our comparative genomic characterization of these strains. Conclusions Using a multi-species comparative supragenomic analysis enabled by an improved version of our finite supragenome model we provide data and an interpretation explaining the relatively larger core genome of S. aureus compared to other opportunistic nasopharyngeal pathogens. In addition, we provide independent validation for the efficiency and effectiveness of our orthologous gene clustering algorithm. PMID:21489287

  6. Brucella suis Vaccine Strain 2 Induces Endoplasmic Reticulum Stress that Affects Intracellular Replication in Goat Trophoblast Cells In vitro

    PubMed Central

    Wang, Xiangguo; Lin, Pengfei; Li, Yang; Xiang, Caixia; Yin, Yanlong; Chen, Zhi; Du, Yue; Zhou, Dong; Jin, Yaping; Wang, Aihua

    2016-01-01

    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

  7. Brucella suis Vaccine Strain 2 Induces Endoplasmic Reticulum Stress that Affects Intracellular Replication in Goat Trophoblast Cells In vitro.

    PubMed

    Wang, Xiangguo; Lin, Pengfei; Li, Yang; Xiang, Caixia; Yin, Yanlong; Chen, Zhi; Du, Yue; Zhou, Dong; Jin, Yaping; Wang, Aihua

    2016-01-01

    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

  8. Actinobacillus suis septicaemia in two foals.

    PubMed

    Nelson, K M; Darien, B J; Konkle, D M; Hartmann, F A

    1996-01-13

    A 24-hour-old Hackney ony filly developed signs of weakness, depression and a poor suck reflex, with harsh lung sounds over both fields, and a 48-hour-old Arabian colt from a normal birth which had sucked vigorously developed loose stools and became depressed, weak and anorectic. Both foals had serum IgG concentrations greater than 800 mg/dl, but each had a severe neutropenia with a left shift, and blood cultures from both of them yielded Actinobacillus suis. The A suis isolates had different antimicrobial susceptibility patterns and, in the case of the Arabian, the isolate was resistant to commonly used broad spectrum antimicrobial agents. PMID:8629322

  9. Are Tritrichomonas foetus and Tritrichomonas suis synonyms?

    PubMed

    Lun, Zhao-Rong; Chen, Xiao-Guang; Zhu, Xing-Quan; Li, Xiang-Rui; Xie, Ming-Quan

    2005-03-01

    Tritrichomonas suis, a tritrichomonad of pigs, and the related species Tritrichomonas foetus, a tritrichomonad of cattle, are morphologically identical. The taxonomic relationship between these two tritrichomonads has been questioned ever since they were established as distinct species in 1843 and 1928, respectively. Here, we compare the similarities of morphology, ultrastructure, distribution, host specificity, characteristics of in vitro cultivation, immunology, biochemistry and analysis of molecular data from published sources between these two species. All data indicate that these two tritrichomonad species are identical. Thus, we propose that T. foetus and T. suis are synonyms. PMID:15734659

  10. Development of colloidal gold-based immunochromatographic assay for rapid detection of Mycoplasma suis in porcine plasma.

    PubMed

    Meng, Kai; Sun, Wenjing; Zhao, Peng; Zhang, Limei; Cai, Dongjie; Cheng, Ziqiang; Guo, Huijun; Liu, Jianzhu; Yang, Dubao; Wang, Shujing; Chai, Tongjie

    2014-05-15

    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. PMID:24434494

  11. Effect of Different Adjuvants on Protection and Side-Effects Induced by Helicobacter suis Whole-Cell Lysate Vaccination

    PubMed Central

    Bosschem, Iris; Bayry, Jagadeesh; De Bruyne, Ellen; Van Deun, Kim; Smet, Annemieke; Vercauteren, Griet; Ducatelle, Richard; Haesebrouck, Freddy; Flahou, Bram

    2015-01-01

    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. PMID:26115373

  12. Human Streptococcus agalactiae isolate in Nile tilapia (Oreochromis niloticus)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus agalactiae, the Lancefield group B Streptococcus (GBS), long recognized as a mammalian pathogen, is an emerging pathogen to fish. We show that a GBS serotype Ia, multilocus sequence type ST-7 isolate from a human neonatal meningitis clinical case causes disease signs and mortality in N...

  13. Occurrence of Isospora suis in larger piglet production units and on specialized piglet rearing farms.

    PubMed

    Meyer, C; Joachim, A; Daugschies, A

    1999-05-01

    Mixed fecal samples of 264 litters from five piglet production farms (155-238 sows/farm) were investigated three times during the suckling period for the occurrence of Isospora suis over the period of 1 year. On all five farms Isopora suis was found to be a common endoparasite with infection rates being highest in litters of 3-4 weeks of age. By the end of the third investigation period the cumulative infection rate was 53.8% of the litters ranging from 20.0% to 81.5% for the single farms. During the suckling period the infection rate increased from 18.6% to 32.6% and then to 37.7%. Diarrhea was present in 66.3% of the sampled litters with the highest rates at the end of the suckling period. 63.4% of the litters which showed diarrhea and 34.8% of those without diarrhea excreted I. suis within the study period. Diarrhea was recorded for 78.2% of the I. suis-positive litters and for 52.5% of the Isospora-negative litters. In summer and fall the occurrence of I. suis was higher (66.3% and 61.0%, respectively) than in spring and winter (47.7% and 37.9%, respectively). In litters with diarrhea and pathogenic E. coli I. suis often occurred simultaneously. Above-average hygiene measures and mainly perforated pen floors seemed to lower the risk of isosporosis. With the exception of Strongyloides ransomi other parasites were not found in the fecal samples of suckling piglets. Two specialized piglet rearing farms, a conventional large-scale rearing unit and a farm managed according to the segregated early weaning (SEW) system were examined three times during the 6-7 week rearing period. In both units I. suis was common, but was not correlated with diarrhea. In the SEW unit the infection rates decreased from 37.5% to 20.2% and to 4.1%, while the infection rate in the conventional unit slightly increased from the first (17.2%) to the second (21.9%) investigation and stayed at this level at the third sampling. PMID:10384903

  14. A Highly Arginolytic Streptococcus Species That Potently Antagonizes Streptococcus mutans.

    PubMed

    Huang, Xuelian; Palmer, Sara R; Ahn, Sang-Joon; Richards, Vincent P; Williams, Matthew L; Nascimento, Marcelle M; Burne, Robert A

    2016-04-01

    The ability of certain oral biofilm bacteria to moderate pH through arginine metabolism by the arginine deiminase system (ADS) is a deterrent to the development of dental caries. Here, we characterize a novel Streptococcus strain, designated strain A12, isolated from supragingival dental plaque of a caries-free individual. A12 not only expressed the ADS pathway at high levels under a variety of conditions but also effectively inhibited growth and two intercellular signaling pathways of the dental caries pathogen Streptococcus mutans. A12 produced copious amounts of H2O2 via the pyruvate oxidase enzyme that were sufficient to arrest the growth of S. mutans. A12 also produced a protease similar to challisin (Sgc) of Streptococcus gordonii that was able to block the competence-stimulating peptide (CSP)-ComDE signaling system, which is essential for bacteriocin production by S. mutans. Wild-type A12, but not an sgc mutant derivative, could protect the sensitive indicator strain Streptococcus sanguinis SK150 from killing by the bacteriocins of S. mutans. A12, but not S. gordonii, could also block the XIP (comX-inducing peptide) signaling pathway, which is the proximal regulator of genetic competence in S. mutans, but Sgc was not required for this activity. The complete genome sequence of A12 was determined, and phylogenomic analyses compared A12 to streptococcal reference genomes. A12 was most similar to Streptococcus australis and Streptococcus parasanguinis but sufficiently different that it may represent a new species. A12-like organisms may play crucial roles in the promotion of stable, health-associated oral biofilm communities by moderating plaque pH and interfering with the growth and virulence of caries pathogens. PMID:26826230

  15. Infections Associated with Streptococcus intermedius in Children.

    PubMed

    Faden, Howard S

    2016-09-01

    Streptococcus intermedius is a viridans Streptococcus belonging to the Anginosus group. In the past 7 years, it has been associated with abscesses in 48 children, 40% of whom had complicated and/or life-threatening illness. It was the sole pathogen in 35 cases. Seventy-five percent of the infections occurred in winter and spring. None occurred in infants younger than 1 year. PMID:27294306

  16. Pathogenicity and molecular characterization of emerging porcine reproductive and respiratory syndrome virus in Vietnam in 2007.

    PubMed

    Metwally, S; Mohamed, F; Faaberg, K; Burrage, T; Prarat, M; Moran, K; Bracht, A; Mayr, G; Berninger, M; Koster, L; To, T L; Nguyen, V L; Reising, M; Landgraf, J; Cox, L; Lubroth, J; Carrillo, C

    2010-10-01

    In 2007, Vietnam experienced swine disease outbreaks causing clinical signs similar to the 'porcine high fever disease' that occurred in China during 2006. Analysis of diagnostic samples from the disease outbreaks in Vietnam identified porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV-2). Additionally, Escherichia coli and Streptococcus equi subspecies zooepidemicus were cultured from lung and spleen, and Streptococcus suis from one spleen sample. Genetic characterization of the Vietnamese PRRSV isolates revealed that this virus belongs to the North American genotype (type 2) with a high nucleotide identity to the recently reported Chinese strains. Amino acid sequence in the nsp2 region revealed 95.7-99.4% identity to Chinese strain HUN4, 68-69% identity to strain VR-2332 and 58-59% identity to strain MN184. A partial deletion in the nsp2 gene was detected; however, this deletion did not appear to enhance the virus pathogenicity in the inoculated pigs. Animal inoculation studies were conducted to determine the pathogenicity of PRRSV and to identify other possible agents present in the original specimens. Pigs inoculated with PRRSV alone and their contacts showed persistent fever, and two of five pigs developed cough, neurological signs and swollen joints. Necropsy examination showed mild to moderate bronchopneumonia, enlarged lymph nodes, fibrinous pericarditis and polyarthritis. PRRSV was re-isolated from blood and tissues of the inoculated and contact pigs. Pigs inoculated with lung and spleen tissue homogenates from sick pigs from Vietnam developed high fever, septicaemia, and died acutely within 72 h, while their contact pigs showed no clinical signs throughout the experiment. Streptococcus equi subspecies zooepidemicus was cultured, and PRRSV was re-isolated only from the inoculated pigs. Results suggest that the cause of the swine deaths in Vietnam is a multifactorial syndrome with PRRSV as a major factor. PMID

  17. Genome-Wide Mapping of Cystitis Due to Streptococcus agalactiae and Escherichia coli in Mice Identifies a Unique Bladder Transcriptome That Signifies Pathogen-Specific Antimicrobial Defense against Urinary Tract Infection

    PubMed Central

    Tan, Chee K.; Carey, Alison J.; Cui, Xiangqin; Webb, Richard I.; Ipe, Deepak; Crowley, Michael; Cripps, Allan W.; Benjamin, William H.; Ulett, Kimberly B.; Schembri, Mark A.

    2012-01-01

    The most common causes of urinary tract infections (UTIs) are Gram-negative pathogens such as Escherichia coli; however, Gram-positive organisms, including Streptococcus agalactiae, or group B streptococcus (GBS), also cause UTI. In GBS infection, UTI progresses to cystitis once the bacteria colonize the bladder, but the host responses triggered in the bladder immediately following infection are largely unknown. Here, we used genome-wide expression profiling to map the bladder transcriptome of GBS UTI in mice infected transurethrally with uropathogenic GBS that was cultured from a 35-year-old women with cystitis. RNA from bladders was applied to Affymetrix Gene-1.0ST microarrays; quantitative reverse transcriptase PCR (qRT-PCR) was used to analyze selected gene responses identified in array data sets. A surprisingly small significant-gene list of 172 genes was identified at 24 h; this compared to 2,507 genes identified in a side-by-side comparison with uropathogenic E. coli (UPEC). No genes exhibited significantly altered expression at 2 h in GBS-infected mice according to arrays despite high bladder bacterial loads at this early time point. The absence of a marked early host response to GBS juxtaposed with broad-based bladder responses activated by UPEC at 2 h. Bioinformatics analyses, including integrative system-level network mapping, revealed multiple activated biological pathways in the GBS bladder transcriptome that regulate leukocyte activation, inflammation, apoptosis, and cytokine-chemokine biosynthesis. These findings define a novel, minimalistic type of bladder host response triggered by GBS UTI, which comprises collective antimicrobial pathways that differ dramatically from those activated by UPEC. Overall, this study emphasizes the unique nature of bladder immune activation mechanisms triggered by distinct uropathogens. PMID:22733575

  18. First Human Case of Meningitis and Sepsis in a Child Caused by Actinobacillus suis or Actinobacillus equuli

    PubMed Central

    Montagnani, Carlotta; Pecile, Patrizia; Moriondo, Maria; Petricci, Patrizia; Becciani, Sabrina; Chiappini, Elena; Indolfi, Giuseppe; Rossolini, Gian Maria; de Martino, Maurizio

    2015-01-01

    We report the first human case of meningitis and sepsis caused in a child by Actinobacillus suis or A. equuli, a common opportunistic pathogen of swine or horses, respectively. Identification was performed by matrix-assisted laser desorption ionization–time of flight mass spectrometry and real-time PCR assay. A previous visit to a farm was suspected as the source of infection. PMID:25878346

  19. Quantification of bovine oxylipids during intramammary Streptococcus uberis infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus uberis mastitis results in severe mammary tissue damage in dairy cows due to uncontrolled inflammation. Oxylipids are potent lipid mediators that orchestrate pathogen-induced inflammatory responses, however, changes in oxylipid biosynthesis during S. uberis mastitis are unknown. Thus, ...

  20. Are Tilapia Infected with Gyrodactylus More Susceptible to Streptococcus?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus iniae and Gyrodactylus niloticus are two common pathogens of cultured Nile tilapia, Oreochromis niloticus. We studied concurrent infection of tilapia by G. niloticus and S. iniae and evaluated whether parasitism in tilapia with Gyrodactylus increased susceptibility and mortality follo...

  1. Transfer of Cystoisospora suis-specific colostral antibodies and their correlation with the course of neonatal porcine cystoisosporosis.

    PubMed

    Schwarz, Lukas; Joachim, Anja; Worliczek, Hanna Lucia

    2013-11-01

    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

  2. Molecular phylogeny and a taxonomic proposal for the genus Streptococcus.

    PubMed

    Póntigo, F; Moraga, M; Flores, S V

    2015-01-01

    Alternative phylogenies for the genus Streptococcus have been proposed due to uncertainty about the among-species group relationships. Here, we performed a phylogenetic analysis of the genus Streptococcus, considering all the species groups and also the genomic data accumulated by other studies. Seventy-five species were subjected to a Bayesian phylogenetic analysis using sequences from eight genes (16S rRNA, rpoB, sodA, tuf, rnpB, gyrB, dnaJ, and recN). On the basis of our results, we propose a new Phylogeny for the genus, with special emphasis on the inter-species group level. This new phylogeny differs from those suggested previously. From topological and evolutionary distance criteria, we propose that gordonii, pluranimalium, and sobrinus should be considered as new species groups, in addition to the currently recognized groups of mutans, bovis, pyogenic, suis, mitis, and salivarius. PMID:26400318

  3. Novel real-time PCR detection assay for Brucella suis

    PubMed Central

    Hänsel, C.; Mertens, K.; Elschner, M. C.; Melzer, F.

    2015-01-01

    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

  4. STREPTOCOCCUS: A WORLDWIDE FISH HEALTH PROBLEM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus iniae and S. agalactiae are important emergent pathogens that affect many fish species worldwide, especially in warm-water regions. In marine and freshwater systems, these Gram-positive bacteria cause significant economic losses, estimated at hundreds of millions of dollars annually. ...

  5. Exposure of feral swine (Sus scrofa) in the United States to selected pathogens

    PubMed Central

    Baroch, John A.; Gagnon, Carl A.; Lacouture, Sonia; Gottschalk, Marcelo

    2015-01-01

    Feral swine (Sus scrofa) are widely distributed in the United States. In 2011 and 2012, serum samples and tonsils were recovered from 162 and 37 feral swine, respectively, in the US to evaluate exposure to important swine endemic pathogens. Antibodies against porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) were found in 2.5% and 25.3% of tested sera, respectively. Positive serological reactions against Mycoplasma hyopneumoniae and Actinobacillus pleuropneumoniae have been detected in 19.7% and 69.7% of animals. More than 15% of animals presented antibodies against these 2 pathogens simultaneously. Most animals were also seropositive for Lawsonia intracellularis. Feral swine can also be involved in transmission of zoonotic agents. Almost 50% of animals possessed antibodies against Salmonella. In addition, 94.4% of animals were carriers of Streptococcus suis in their tonsils. In conclusion, feral swine may be considered as a potential reservoir for different endemic diseases in domestic pigs, as well as for important zoonotic agents. PMID:25673913

  6. Exposure of feral swine (Sus scrofa) in the United States to selected pathogens.

    PubMed

    Baroch, John A; Gagnon, Carl A; Lacouture, Sonia; Gottschalk, Marcelo

    2015-01-01

    Feral swine (Sus scrofa) are widely distributed in the United States. In 2011 and 2012, serum samples and tonsils were recovered from 162 and 37 feral swine, respectively, in the US to evaluate exposure to important swine endemic pathogens. Antibodies against porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) were found in 2.5% and 25.3% of tested sera, respectively. Positive serological reactions against Mycoplasma hyopneumoniae and Actinobacillus pleuropneumoniae have been detected in 19.7% and 69.7% of animals. More than 15% of animals presented antibodies against these 2 pathogens simultaneously. Most animals were also seropositive for Lawsonia intracellularis. Feral swine can also be involved in transmission of zoonotic agents. Almost 50% of animals possessed antibodies against Salmonella. In addition, 94.4% of animals were carriers of Streptococcus suis in their tonsils. In conclusion, feral swine may be considered as a potential reservoir for different endemic diseases in domestic pigs, as well as for important zoonotic agents. PMID:25673913

  7. Duplex PCR for differentiation of the vaccine strain Brucella suis S2 and B. suis biovar 1 from other strains of Brucella spp.

    PubMed

    Nan, Wenlong; Tan, Pengfei; Wang, Yong; Xu, Zouliang; Mao, Kairong; Peng, Daxin; Chen, Yiping

    2014-09-01

    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. PMID:25011712

  8. Brucella suis strain 2 vaccine is safe and protective against heterologous Brucella spp. infections.

    PubMed

    Zhu, Liangquan; Feng, Yu; Zhang, Ge; Jiang, Hui; Zhang, Zhen; Wang, Nan; Ding, Jiabo; Suo, Xun

    2016-01-12

    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. PMID:26626213

  9. Pathogenicity and virulence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many pathogenic microorganisms are host-specific in that they parasitize only one or a few animal species. For example, the cause of equine strangles, Streptococcus equi subspecies equi, is essentially limited to infection of horses. Others—certain Salmonella serotypes, for example—have a broad host...

  10. In vitro hatching of Trichuris suis eggs.

    PubMed

    Vejzagić, Nermina; Thamsborg, Stig Milan; Kringel, Helene; Roepstorff, Allan; Bruun, Johan Musaeus; Kapel, Christian M O

    2015-07-01

    Eggs of the pig whipworm, Trichuris suis ova (TSO), are currently tested in human clinical trials for their potential immunomodulatory capacity. The biological potency of TSO (egg viability and infectivity) is traditionally assessed in Göttingen minipigs as the establishment of intestinal larvae after inoculation with a known number of eggs. To minimize testing in animal models, development of an in vitro egg hatching assay is proposed as a reliable, cost-effective, and a faster alternative to test the egg viability. The present study aimed to investigate the influence of different chemical, physical, and biological factors on egg hatching. Thus, in a series of experiments and in different combinations, the eggs were stimulated with glass beads, artificial gastric juice, bile salt and trypsin solution, fermentation gut medium, or stimulated with mucosal scrapings from the ileum and the large intestine of the infected and uninfected Göttingen minipig. Mechanical stimulation with glass beads presented a simple and reproducible method for egg hatching. However, incubation of eggs with mucosal scrapings from the ileum, caecum, and colon for 24 h at 38 °C significantly increased hatching. PMID:26008635

  11. Transcriptome-Wide Identification of Hfq-Associated RNAs in Brucella suis by Deep Sequencing

    PubMed Central

    Saadeh, Bashir; Caswell, Clayton C.; Berta, Philippe; Wattam, Alice Rebecca; Roop, R. Martin

    2015-01-01

    ABSTRACT Recent breakthroughs in next-generation sequencing technologies have led to the identification of small noncoding RNAs (sRNAs) as a new important class of regulatory molecules. In prokaryotes, sRNAs are often bound to the chaperone protein Hfq, which allows them to interact with their partner mRNA(s). We screened the genome of the zoonotic and human pathogen Brucella suis 1330 for the presence of this class of RNAs. We designed a coimmunoprecipitation strategy that relies on the use of Hfq as a bait to enrich the sample with sRNAs and eventually their target mRNAs. By deep sequencing analysis of the Hfq-bound transcripts, we identified a number of mRNAs and 33 sRNA candidates associated with Hfq. The expression of 10 sRNAs in the early stationary growth phase was experimentally confirmed by Northern blotting and/or reverse transcriptase PCR. IMPORTANCE Brucella organisms are facultative intracellular pathogens that use stealth strategies to avoid host defenses. Adaptation to the host environment requires tight control of gene expression. Recently, small noncoding RNAs (sRNAs) and the sRNA chaperone Hfq have been shown to play a role in the fine-tuning of gene expression. Here we have used RNA sequencing to identify RNAs associated with the B. suis Hfq protein. We have identified a novel list of 33 sRNAs and 62 Hfq-associated mRNAs for future studies aiming to understand the intracellular lifestyle of this pathogen. PMID:26553849

  12. Development of a LAMP assay for rapid detection of different intimin variants of attaching and effacing microbial pathogens.

    PubMed

    Xue-han, Zhang; Qing, Ye; Ya-dong, Liu; Bin, Li; Renata, Ivanek; Kong-wang, He

    2013-11-01

    Intimin harboured by pathogenic Escherichia coli (E. coli) strains is a key virulence factor involved in host cell adherence and colonization. Twenty-seven intimin-encoding E. coli attaching and effacing (eae) gene variants have been reported according to their 3' binding domain sequences. In our study, we developed a specific and sensitive loop-mediated isothermal amplification (LAMP) assay to detect all known intimin variants. Four primers specific for six regions of eae genes were designed using online software. The eae-LAMP assay was highly specific and detected all 27 tested eae variants; no cross-reactions were observed with genes from enterotoxigenic E. coli (ETEC), E. coli BL21, Salmonella, Shigella, Listeria monocytogenes, or Streptococcus suis type 2 (SS2). With the lowest detection limit of approximately 10 copies per reaction the eae-LAMP assay was 100 times more sensitive than conventional PCR. These results, and the results of tests involving food and faecal samples artificially contaminated with E. coli O157 : H7 (eaeγ+), show that the eae-LAMP assay is a simple, rapid, sensitive and specific tool for detecting intimin variants from pathogenic strains of E. coli. The eae-LAMP assay has great potential for wider applications, not only in the laboratory but also in the field setting, as it does not require specialized equipment. PMID:23893919

  13. Development of Primer Sets for Loop-Mediated Isothermal Amplification that Enables Rapid and Specific Detection of Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae

    PubMed Central

    Wang, Deguo; Liu, Yanhong

    2015-01-01

    Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae are the three main pathogens causing bovine mastitis, with great losses to the dairy industry. Rapid and specific loop-mediated isothermal amplification methods (LAMP) for identification and differentiation of these three pathogens are not available. With the 16S rRNA gene and 16S-23S rRNA intergenic spacers as targets, four sets of LAMP primers were designed for identification and differentiation of S. dysgalactiae, S. uberis and S. agalactiae. The detection limit of all four LAMP primer sets were 0.1 pg DNA template per reaction, the LAMP method with 16S rRNA gene and 16S-23S rRNA intergenic spacers as the targets can differentiate the three pathogens, which is potentially useful in epidemiological studies. PMID:26016433

  14. Development of Primer Sets for Loop-Mediated Isothermal Amplification that Enables Rapid and Specific Detection of Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae.

    PubMed

    Wang, Deguo; Liu, Yanhong

    2015-06-01

    Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae are the three main pathogens causing bovine mastitis, with great losses to the dairy industry. Rapid and specific loop-mediated isothermal amplification methods (LAMP) for identification and differentiation of these three pathogens are not available. With the 16S rRNA gene and 16S-23S rRNA intergenic spacers as targets, four sets of LAMP primers were designed for identification and differentiation of S. dysgalactiae, S. uberis and S. agalactiae. The detection limit of all four LAMP primer sets were 0.1 pg DNA template per reaction, the LAMP method with 16S rRNA gene and 16S-23S rRNA intergenic spacers as the targets can differentiate the three pathogens, which is potentially useful in epidemiological studies. PMID:26016433

  15. Streptococcus agalactiae mastitis: a review.

    PubMed Central

    Keefe, G P

    1997-01-01

    Streptococcus agalactiae continues to be a major cause of subclinical mastitis in dairy cattle and a source of economic loss for the industry. Veterinarians are often asked to provide information on herd level control and eradication of S. agalactiae mastitis. This review collects and collates relevant publications on the subject. The literature search was conducted in 1993 on the Agricola database. Articles related to S. agalactiae epidemiology, pathogen identification techniques, milk quality consequences, and control, prevention, and therapy were included. Streptococcus agalactiae is an oblique parasite of the bovine mammary gland and is susceptible to treatment with a variety of antibiotics. Despite this fact, where state or provincial census data are available, herd prevalence levels range from 11% (Alberta, 1991) to 47% (Vermont, 1985). Infection with S. agalactiae is associated with elevated somatic cell count and total bacteria count and a decrease in the quantity and quality of milk products produced. Bulk tank milk culture has, using traditional milk culture techniques, had a low sensitivity for identifying S. agalactiae at the herd level. New culture methods, using selective media and large inocula, have substantially improved the sensitivity of bulk tank culture. Efficacy of therapy on individual cows remains high. Protocols for therapy of all infected animals in a herd are generally successful in eradicating the pathogen from the herd, especially if they are followed up with good udder hygiene techniques. PMID:9220132

  16. Identification of Mycoplasma suis antigens and development of a multiplex microbead immunoassay.

    PubMed

    Guimaraes, Ana M S; Santos, Andrea P; Timenetsky, Jorge; Bower, Leslie P; Strait, Erin; Messick, Joanne B

    2014-03-01

    The aims of the current study were to identify Mycoplasma suis antigens and develop a multiplex microbead immunoassay (MIA). A M. suis-expression library was screened for immunogens using sera from infected pigs. Based on bioinformatics, putative antigens were identified within positive inserts; gene fragments were expressed and purified as polyhistidine fusion proteins, and immunoreactivity was confirmed by Western blot. Selected antigens were used to develop a MIA. Sera from noninfected and infected pigs were used to set the median fluorescent intensity (MFI) cutoffs and as positive controls, respectively. Assay specificity was tested using sera from pigs seropositive for other pathogens (2 different pigs seropositive for each pathogen). Samples from 51 field pigs and 2 pigs during the course of acute (pig 1) and chronic (pig 2) infections were tested using MIA, indirect hemagglutination assay (IHA), and quantitative polymerase chain reaction (qPCR). Sixteen reactive plaques (52 genes) were detected. A heat-shock protein (GrpE), a nicotinamide adenine dinucleotide-dependent glyceraldehyde 3-phosphate dehydrogenase (GAPN), and 4 proteins from paralogous gene families (PGFs) were identified as antigens by Western blot. While GrpE, GAPN, and 1 PGF protein were strong antigens, the others were not suitable as MIA targets. A MIA using GrpE, GAPN, and the strongly reactive PGF protein was developed. Cross-reactivity with sera from pigs infected with Mycoplasma hyopneumoniae, Porcine circovirus-2, Porcine parvovirus, Porcine reproductive and respiratory syndrome virus, and Porcine respiratory coronavirus with this MIA was not observed. Pig 2 was consistently positive by MIA and qPCR, whereas pig 1, initially negative, seroconverted before becoming qPCR positive. Only 2 samples (from pig 1) were IHA positive. Five (9.8%) field samples were qPCR positive and 40 (78.43%) were positive for all 3 MIA antigens; however, all were IHA negative. In summary, the MIA is specific

  17. INFLUENCE OF NATURAL TRICHODINA SP.PARASITISM ON EXPERIMENTAL STREPTOCOCCUS INIAE OR Streptococcus AGALACTIAE INFECTION AND SURVIVAL OF YOUNG CHANNEL CATFISH ICTALURUS PUNCTATUS (RAFINESQUE)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus iniae and S. agalactiae are usually not considered pathogens of channel catfish, Ictalurus punctatus, though concurrent infections may decrease catfish survival when infected with streptococcal organisms. Non-parasitized or naturally-parasitized channel catfish fry were challenged wit...

  18. Draft Genome Sequences for Seven Streptococcus parauberis Isolates from Wild Fish in the Chesapeake Bay.

    PubMed

    Haines, Ashley; Nebergall, Emily; Besong, Elvira; Council, Kimaya; Lambert, Onaysha; Gauthier, David

    2016-01-01

    Streptococcus parauberis is a pathogen of cattle and fish, closely related Streptococcus uberis and Streptococcus iniae We report the genomes of seven S. parauberis strains recovered from striped bass (Morone saxatilis) in the Chesapeake Bay. The availability of these genomes will allow comparative genomic analysis of Chesapeake Bay S. parauberis strains versus S. parauberis cultured from other animal hosts and geographic regions. PMID:27540054

  19. Draft Genome Sequences for Seven Streptococcus parauberis Isolates from Wild Fish in the Chesapeake Bay

    PubMed Central

    Nebergall, Emily; Besong, Elvira; Council, Kimaya; Lambert, Onaysha; Gauthier, David

    2016-01-01

    Streptococcus parauberis is a pathogen of cattle and fish, closely related Streptococcus uberis and Streptococcus iniae. We report the genomes of seven S. parauberis strains recovered from striped bass (Morone saxatilis) in the Chesapeake Bay. The availability of these genomes will allow comparative genomic analysis of Chesapeake Bay S. parauberis strains versus S. parauberis cultured from other animal hosts and geographic regions. PMID:27540054

  20. Isolation of Actinobacillus suis from a cat's lung.

    PubMed Central

    Daignault, D; Chouinard, L; Møller, K; Ahrens, P; Messier, S; Higgins, R

    1999-01-01

    Actinobacillus suis has been isolated from the lungs of 9-month-old cat. The bacterium was characterized biochemically as well as genetically, and its sensitivity profile to different antimicrobial agents was established. The role of this isolate in the cat's condition is discussed. PMID:9919368

  1. Interactions of Lactobacilli with Pathogenic Streptococcus pyogenes

    PubMed Central

    Westbroek, Mark L.; Davis, Crystal L.; Fawson, Lena S.; Price, Travis M.

    2010-01-01

    Objective. To determine whether (1) a decreased concentration of Lactobacilli allows S. pyogenes to grow; (2) S. pyogenes is able to grow in the presence of healthy Lactobacillus concentrations; (3) S. pyogenes is capable of inhibiting Lactobacilli. Methods. One hundred fifty patient samples of S. pyogenes were mixed with four different concentrations of L. crispatus and L. jensenii. Colony counts and pH measurements were taken from these concentrations and compared using t-tests and ANOVA statistical analyses. Results. Statistical tests showed no significant difference between the colony counts of S. pyogenes by itself and growth when mixed with Lactobacilli, and no significant difference between the colony counts of S. pyogenes in the four different concentrations of Lactobacilli. Conclusion. The statistical data representing the growth of these two organisms suggests that Lactobacilli did not inhibit the growth of S. pyogenes. Also, S. pyogenes did not inhibit the growth of Lactobacilli. PMID:20508738

  2. The BtaF Trimeric Autotransporter of Brucella suis Is Involved in Attachment to Various Surfaces, Resistance to Serum and Virulence

    PubMed Central

    Ruiz-Ranwez, Verónica; Posadas, Diana M.; Estein, Silvia M.; Abdian, Patricia L.; Martin, Fernando A.; Zorreguieta, Angeles

    2013-01-01

    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

  3. Development of a diagnostic PCR assay based on novel DNA sequences for the detection of Mycoplasma suis (Eperythrozoon suis) in porcine blood.

    PubMed

    Hoelzle, Ludwig E; Adelt, Dagmar; Hoelzle, Katharina; Heinritzi, Karl; Wittenbrink, Max M

    2003-05-29

    An efficient method of control of porcine eperythrozoonosis (PE) caused by Mycoplasma suis is eradication of infection by detection and removal of infected carrier animals. At present, only a few tests are available for the diagnosis of these latent M. suis infections in pigs. The objective of this study was to develop a PCR assay based on novel DNA sequences for the identification of M. suis-infected pigs. A 1.8 kb EcoRI DNA fragment of the M. suis genome was isolated from the blood of pigs experimentally infected with M. suis. Specificity of the DNA fragment was confirmed by DNA sequence analysis and PCR using primers directed against sequences contained in the 1.8 kb fragment. PCR products of 782 bp in size were amplified only from M. suis particles prepared from the blood of experimentally infected pigs but not from any controls, comprising blood from gnotobiotic piglets and a panel of bacteria including other porcine mycoplasmas. PCR results were confirmed by dot blot hybridisation. The applicability of the PCR assay to diagnose M. suis infections in pigs was evaluated by investigating blood samples from 10 symptomatic pigs with clinical signs typical of porcine eperythrozoonosis and blood samples from 10 healthy pigs. The M. suis-specific PCR product was amplified from all samples taken at episodes of acute disease as well as from samples taken during the latent stage of infection, thus demonstrating the suitability of the PCR assay for detecting latent infected carrier animals. PMID:12695043

  4. Proinflammatory caspase-2-mediated macrophage cell death induced by a rough attenuated Brucella suis strain.

    PubMed

    Chen, Fang; Ding, Xicheng; Ding, Ying; Xiang, Zuoshuang; Li, Xinna; Ghosh, Debashis; Schurig, Gerhardt G; Sriranganathan, Nammalwar; Boyle, Stephen M; He, Yongqun

    2011-06-01

    Brucella spp. are intracellular bacteria that cause an infectious disease called brucellosis in humans and many domestic and wildlife animals. B. suis primarily infects pigs and is pathogenic to humans. The macrophage-Brucella interaction is critical for the establishment of a chronic Brucella infection. Our studies showed that smooth virulent B. suis strain 1330 (S1330) prevented programmed cell death of infected macrophages and rough attenuated B. suis strain VTRS1 (a vaccine candidate) induced strong macrophage cell death. To further investigate the mechanism of VTRS1-induced macrophage cell death, microarrays were used to analyze temporal transcriptional responses of murine macrophage-like J774.A1 cells infected with S1330 or VTRS1. In total 17,685 probe sets were significantly regulated based on the effects of strain, time and their interactions. A miniTUBA dynamic Bayesian network analysis predicted that VTRS1-induced macrophage cell death was mediated by a proinflammatory gene (the tumor necrosis factor alpha [TNF-α] gene), an NF-κB pathway gene (the IκB-α gene), the caspase-2 gene, and several other genes. VTRS1 induced significantly higher levels of transcription of 40 proinflammatory genes than S1330. A Mann-Whitney U test confirmed the proinflammatory response in VTRS1-infected macrophages. Increased production of TNF-α and interleukin 1β (IL-1β) were also detected in the supernatants in VTRS1-infected macrophage cell culture. Hyperphosphorylation of IκB-α was observed in macrophages infected with VTRS1 but not S1330. The important roles of TNF-α and IκB-α in VTRS1-induced macrophage cell death were further confirmed by individual inhibition studies. VTRS1-induced macrophage cell death was significantly inhibited by a caspase-2 inhibitor but not a caspase-1 inhibitor. The role of caspase-2 in regulating the programmed cell death of VTRS1-infected macrophages was confirmed in another study using caspase-2-knockout mice. In summary, VTRS1

  5. CONCURRENT EXPERIMENTAL Streptococcus SPP. INFECTIONS AND NATURAL PARASITISM IN CHANNEL CATFISH Ictalurus punctatus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus iniae and S. agalactiae are usually not considered pathogens of channel catfish, Ictalurus punctatus, though concurrent infections may decrease catfish survival when infected with streptococcal organisms. Non-parasitized or naturally-parasitized channel catfish fry were challenged wit...

  6. Bath immersion, booster vaccination strategy holds potential for protecting juvenile tilapia against Streptococcus iniae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus iniae is a significant bacterial pathogen that causes hemorrhagic septicemia and meningoencephalitis in tilapia, hybrid striped bass, rainbow trout, olive flounder, yellowtail, barramundi and other species of cultured and wild fish worldwide. In tilapia production, vaccination of fry ...

  7. Streptococcus Adherence and Colonization

    PubMed Central

    Nobbs, Angela H.; Lamont, Richard J.; Jenkinson, Howard F.

    2009-01-01

    Summary: Streptococci readily colonize mucosal tissues in the nasopharynx; the respiratory, gastrointestinal, and genitourinary tracts; and the skin. Each ecological niche presents a series of challenges to successful colonization with which streptococci have to contend. Some species exist in equilibrium with their host, neither stimulating nor submitting to immune defenses mounted against them. Most are either opportunistic or true pathogens responsible for diseases such as pharyngitis, tooth decay, necrotizing fasciitis, infective endocarditis, and meningitis. Part of the success of streptococci as colonizers is attributable to the spectrum of proteins expressed on their surfaces. Adhesins enable interactions with salivary, serum, and extracellular matrix components; host cells; and other microbes. This is the essential first step to colonization, the development of complex communities, and possible invasion of host tissues. The majority of streptococcal adhesins are anchored to the cell wall via a C-terminal LPxTz motif. Other proteins may be surface anchored through N-terminal lipid modifications, while the mechanism of cell wall associations for others remains unclear. Collectively, these surface-bound proteins provide Streptococcus species with a “coat of many colors,” enabling multiple intimate contacts and interplays between the bacterial cell and the host. In vitro and in vivo studies have demonstrated direct roles for many streptococcal adhesins as colonization or virulence factors, making them attractive targets for therapeutic and preventive strategies against streptococcal infections. There is, therefore, much focus on applying increasingly advanced molecular techniques to determine the precise structures and functions of these proteins, and their regulatory pathways, so that more targeted approaches can be developed. PMID:19721085

  8. A genome-wide SNP-based phylogenetic analysis distinguishes different biovars of Brucella suis.

    PubMed

    Sankarasubramanian, Jagadesan; Vishnu, Udayakumar S; Gunasekaran, Paramasamy; Rajendhran, Jeyaprakash

    2016-07-01

    Brucellosis is an important zoonotic disease caused by Brucella spp. Brucella suis is the etiological agent of porcine brucellosis. B. suis is the most genetically diverged species within the genus Brucella. We present the first large-scale B. suis phylogenetic analysis based on an alignment-free k-mer approach of gathering polymorphic sites from whole genome sequences. Genome-wide core-SNP based phylogenetic tree clearly differentiated and discriminated the B. suis biovars and the vaccine strain into different clades. A total of 16,756 SNPs were identified from the genome sequences of 54 B. suis strains. Also, biovar-specific SNPs were identified. The vaccine strain B. suis S2-30 is extensively used in China, which was discriminated from all biovars with the accumulation of the highest number of SNPs. We have also identified the SNPs between B. suis vaccine strain S2-30 and its closest homolog, B. suis biovar 513UK. The highest number of mutations (22) was observed in the phosphomannomutase (pmm) gene essential for the synthesis of O-antigen. Also, mutations were identified in several virulent genes including genes coding for type IV secretion system and the effector proteins, which could be responsible for the attenuated virulence of B. suis S2-30. PMID:27085292

  9. Characterisation of Brucella suis isolates from Southeast Europe by multi-locus variable-number tandem repeat analysis.

    PubMed

    Duvnjak, Sanja; Račić, Ivana; Špičić, Silvio; Zdelar-Tuk, Maja; Reil, Irena; Cvetnić, Željko

    2015-10-22

    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. PMID:26324171

  10. Comparative genomics of the dairy isolate Streptococcus macedonicus ACA-DC 198 against related members of the Streptococcus bovis/Streptococcus equinus complex

    PubMed Central

    2014-01-01

    Background Within the genus Streptococcus, only Streptococcus thermophilus is used as a starter culture in food fermentations. Streptococcus macedonicus though, which belongs to the Streptococcus bovis/Streptococcus equinus complex (SBSEC), is also frequently isolated from fermented foods mainly of dairy origin. Members of the SBSEC have been implicated in human endocarditis and colon cancer. Here we compare the genome sequence of the dairy isolate S. macedonicus ACA-DC 198 to the other SBSEC genomes in order to assess in silico its potential adaptation to milk and its pathogenicity status. Results Despite the fact that the SBSEC species were found tightly related based on whole genome phylogeny of streptococci, two distinct patterns of evolution were identified among them. Streptococcus macedonicus, Streptococcus infantarius CJ18 and Streptococcus pasteurianus ATCC 43144 seem to have undergone reductive evolution resulting in significantly diminished genome sizes and increased percentages of potential pseudogenes when compared to Streptococcus gallolyticus subsp. gallolyticus. In addition, the three species seem to have lost genes for catabolizing complex plant carbohydrates and for detoxifying toxic substances previously linked to the ability of S. gallolyticus to survive in the rumen. Analysis of the S. macedonicus genome revealed features that could support adaptation to milk, including an extra gene cluster for lactose and galactose metabolism, a proteolytic system for casein hydrolysis, auxotrophy for several vitamins, an increased ability to resist bacteriophages and horizontal gene transfer events with the dairy Lactococcus lactis and S. thermophilus as potential donors. In addition, S. macedonicus lacks several pathogenicity-related genes found in S. gallolyticus. For example, S. macedonicus has retained only one (i.e. the pil3) of the three pilus gene clusters which may mediate the binding of S. gallolyticus to the extracellular matrix. Unexpectedly

  11. AN OVERVIEW STREPTOCOCCUS IN WARM-WATER FISH

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite being known mainly as mammalian disease agents, Streptococcus iniae and S. agalactiae have become recognized as emerging pathogens of wild and cultured fish. The worldwide economic impact of S. iniae and S. agalactiae to the aquaculture industry is estimated in hundreds of millions annually...

  12. Streptococcus: A World-Wide Fish Health Problem

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus iniae and S. agalactiae are important emergent-epizootic pathogens which affect many fish species world-wide, especially in warm-water regions. Further, these Gram-positive bacteria cause significant economic losses in marine and freshwater aquaculture systems with an estimated loss i...

  13. Acute Mastoiditis Caused by Streptococcus pneumoniae.

    PubMed

    Obringer, Emily; Chen, Judy L

    2016-05-01

    Acute mastoiditis (AM) is a relatively rare complication of acute otitis media (AOM). The most common pathogens include Streptococcus pneumoniae, Streptococcus pyogenes, and Staphylococcus aureus. Pneumococcal vaccination and changes in antibiotic prescribing recommendations for AOM may change the incidence of AM in the future. Diagnosis of AM can be made based on clinical presentation, but computed tomography of the temporal bone with contrast should be considered if there is concern for complicated AM. Both extracranial and intracranial complications of AM may occur. Previously, routine cortical mastoidectomy was recommended for AM treatment, but new data suggest that a more conservative treatment approach can be considered, including intravenous (IV) antibiotics alone or IV antibiotics with myringotomy. [Pediatr Ann. 2016;45(5):e176-e179.]. PMID:27171806

  14. Surface plasmon resonance biosensors for detection of pathogenic microorganisms: strategies to secure food and environmental safety.

    PubMed

    Bergwerff, Aldert A; van Knapen, Frans

    2006-01-01

    This review describes the exploitation of exclusively optical surface plasmon resonance (SPR) biosensors for the direct and indirect detection of pathogenic microorganisms in food chains and the environment. Direct detection is, in most cases, facilitated by the use of defined monoclonal or polyclonal antibodies raised against (a part of) the target pathogenic microorganisms. The antibodies were immobilized to a solid phase of the sensor to capture the microbe from the sample. Alternatively, antibodies were used in an inhibition-like assay involving incubation with the target organism prior to analysis of nonbound antibodies. The free immunoglobins were screened on a sensor surface coated with either purified antigens or with Fc or Fab binding antibodies. Discussed examples of these approaches are the determination of Escherichia coli O1 57:H7, Salmonella spp., and Listeria monocytogenes. Another direct detection strategy involved SPR analysis of polymerase chain reaction products of Shiga toxin-2 genes reporting the presence of E. coli O157:H7 in human stool. Metabolic products have been exploited as biomarkers for the presence of a microbial agent, such as enterotoxin B and a virulence factor for the occurrence of Staphylococcus aureus and Streptococcus suis, respectively. Indirect detection, on the other hand, is performed by analysis of a humoral immune response of the infected animal or human. By immobilization of specific antigenic structures, infections with Herpes simplex and human immunodeficiency viruses, Salmonella and Treponema pallidum bacteria, and Schistosoma spp. parasites were revealed using human, avian, and porcine sera and avian eggs. Bound antibodies were easily isotyped using an SPR biosensor to reveal the infection history of the individual. Discussed studies show the recent recognition of the suitability of this type of instrument for (rapid) detection of health-threatening microbes to food and environmental microbial safety. PMID:16792081

  15. Genome and transcriptome of the porcine whipworm Trichuris suis

    PubMed Central

    Jex, Aaron R.; Nejsum, Peter; Schwarz, Erich M.; Hu, Li; Young, Neil D.; Hall, Ross S.; Korhonen, Pasi K.; Liao, Shengguang; Thamsborg, Stig; Xia, Jinquan; Xu, Pengwei; Wang, Shaowei; Scheerlinck, Jean-Pierre Y.; Hofmann, Andreas; Sternberg, Paul W.; Wang, Jun; Gasser, Robin B.

    2014-01-01

    Trichuris (whipworm) infects 1 billion people worldwide, and causes a disease (trichuriasis) that results in major socioeconomic losses in both humans and pigs. Trichuriasis relates to an inflammation of the large intestine manifested in bloody diarrhoea, and chronic disease can cause malnourishment and stunting in children. Paradoxically, Trichuris of pigs has shown substantial promise as a treatment for human autoimmune disorders, including inflammatory bowel disease (IBD) and multiple sclerosis (MS). Here, we report ~80 megabase (Mb) draft assemblies of the genomes of adult male and female T. suis, and explore stage-, sex- and tissue-specific transcription of messenger and small non-coding RNAs. PMID:24929829

  16. Surface Interactome in Streptococcus pyogenes*

    PubMed Central

    Galeotti, Cesira L.; Bove, Elia; Pezzicoli, Alfredo; Nogarotto, Renzo; Norais, Nathalie; Pileri, Silvia; Lelli, Barbara; Falugi, Fabiana; Balloni, Sergio; Tedde, Vittorio; Chiarot, Emiliano; Bombaci, Mauro; Soriani, Marco; Bracci, Luisa; Grandi, Guido; Grifantini, Renata

    2012-01-01

    Very few studies have so far been dedicated to the systematic analysis of protein interactions occurring between surface and/or secreted proteins in bacteria. Such interactions are expected to play pivotal biological roles that deserve investigation. Taking advantage of the availability of a detailed map of surface and secreted proteins in Streptococcus pyogenes (group A Streptococcus (GAS)), we used protein array technology to define the “surface interactome” in this important human pathogen. Eighty-three proteins were spotted on glass slides in high density format, and each of the spotted proteins was probed for its capacity to interact with any of the immobilized proteins. A total of 146 interactions were identified, 25 of which classified as “reciprocal,” namely, interactions that occur irrespective of which of the two partners was immobilized on the chip or in solution. Several of these interactions were validated by surface plasmon resonance and supported by confocal microscopy analysis of whole bacterial cells. By this approach, a number of interesting interactions have been discovered, including those occurring between OppA, DppA, PrsA, and TlpA, proteins known to be involved in protein folding and transport. These proteins, all localizing at the septum, might be part, together with HtrA, of the recently described ExPortal complex of GAS. Furthermore, SpeI was found to strongly interact with the metal transporters AdcA and Lmb. Because SpeI strictly requires zinc to exert its function, this finding provides evidence on how this superantigen, a major player in GAS pathogenesis, can acquire the metal in the host environment, where it is largely sequestered by carrier proteins. We believe that the approach proposed herein can lead to a deeper knowledge of the mechanisms underlying bacterial invasion, colonization, and pathogenesis. PMID:22199230

  17. Surface interactome in Streptococcus pyogenes.

    PubMed

    Galeotti, Cesira L; Bove, Elia; Pezzicoli, Alfredo; Nogarotto, Renzo; Norais, Nathalie; Pileri, Silvia; Lelli, Barbara; Falugi, Fabiana; Balloni, Sergio; Tedde, Vittorio; Chiarot, Emiliano; Bombaci, Mauro; Soriani, Marco; Bracci, Luisa; Grandi, Guido; Grifantini, Renata

    2012-04-01

    Very few studies have so far been dedicated to the systematic analysis of protein interactions occurring between surface and/or secreted proteins in bacteria. Such interactions are expected to play pivotal biological roles that deserve investigation. Taking advantage of the availability of a detailed map of surface and secreted proteins in Streptococcus pyogenes (group A Streptococcus (GAS)), we used protein array technology to define the "surface interactome" in this important human pathogen. Eighty-three proteins were spotted on glass slides in high density format, and each of the spotted proteins was probed for its capacity to interact with any of the immobilized proteins. A total of 146 interactions were identified, 25 of which classified as "reciprocal," namely, interactions that occur irrespective of which of the two partners was immobilized on the chip or in solution. Several of these interactions were validated by surface plasmon resonance and supported by confocal microscopy analysis of whole bacterial cells. By this approach, a number of interesting interactions have been discovered, including those occurring between OppA, DppA, PrsA, and TlpA, proteins known to be involved in protein folding and transport. These proteins, all localizing at the septum, might be part, together with HtrA, of the recently described ExPortal complex of GAS. Furthermore, SpeI was found to strongly interact with the metal transporters AdcA and Lmb. Because SpeI strictly requires zinc to exert its function, this finding provides evidence on how this superantigen, a major player in GAS pathogenesis, can acquire the metal in the host environment, where it is largely sequestered by carrier proteins. We believe that the approach proposed herein can lead to a deeper knowledge of the mechanisms underlying bacterial invasion, colonization, and pathogenesis. PMID:22199230

  18. Status of research and development of vaccines for Streptococcus pyogenes.

    PubMed

    Steer, Andrew C; Carapetis, Jonathan R; Dale, James B; Fraser, John D; Good, Michael F; Guilherme, Luiza; Moreland, Nicole J; Mulholland, E Kim; Schodel, Florian; Smeesters, Pierre R

    2016-06-01

    Streptococcus pyogenes is an important global pathogen, causing considerable morbidity and mortality, especially in low and middle income countries where rheumatic heart disease and invasive infections are common. There is a number of promising vaccine candidates, most notably those based on the M protein, the key virulence factor for the bacterium. Vaccines against Streptococcus pyogenes are considered as impeded vaccines because of a number of crucial barriers to development. Considerable effort is needed by key players to bring current vaccine candidates through phase III clinical trials and there is a clear need to develop a roadmap for future development of current and new candidates. PMID:27032515

  19. Fluoroquinolone Resistance among Clonal Complex 1 Group B Streptococcus Strains

    PubMed Central

    Teatero, Sarah; Patel, Samir N.

    2016-01-01

    Fluoroquinolone resistance in group B Streptococcus is increasingly being reported worldwide. Here, we correlated fluoroquinolone resistance with mutations in gyrA, gyrB, parC, and parE genes, identified by mining whole-genome sequencing (WGS) data of 190 clonal complex 1 group B Streptococcus strains recovered from patients with invasive diseases in North America. We report a high prevalence of fluoroquinolone resistance (12%) among GBS strains in our collection. Our approach is the first step towards accurate prediction of fluoroquinolone resistance from WGS data in this opportunistic pathogen. PMID:27559344

  20. Fluoroquinolone Resistance among Clonal Complex 1 Group B Streptococcus Strains.

    PubMed

    Neemuchwala, Alefiya; Teatero, Sarah; Patel, Samir N; Fittipaldi, Nahuel

    2016-01-01

    Fluoroquinolone resistance in group B Streptococcus is increasingly being reported worldwide. Here, we correlated fluoroquinolone resistance with mutations in gyrA, gyrB, parC, and parE genes, identified by mining whole-genome sequencing (WGS) data of 190 clonal complex 1 group B Streptococcus strains recovered from patients with invasive diseases in North America. We report a high prevalence of fluoroquinolone resistance (12%) among GBS strains in our collection. Our approach is the first step towards accurate prediction of fluoroquinolone resistance from WGS data in this opportunistic pathogen. PMID:27559344

  1. Acid tolerance mechanisms utilized by Streptococcus mutans

    PubMed Central

    Matsui, Robert; Cvitkovitch, Dennis

    2010-01-01

    Since its discovery in 1924 by J Clarke, Streptococcus mutans has been the focus of rigorous research efforts due to its involvement in caries initiation and progression. Its ability to ferment a range of dietary carbohydrates can rapidly drop the external environmental pH, thereby making dental plaque inhabitable to many competing species and can ultimately lead to tooth decay. Acid production by this oral pathogen would prove suicidal if not for its remarkable ability to withstand the acid onslaught by utilizing a wide variety of highly evolved acid-tolerance mechanisms. The elucidation of these mechanisms will be discussed, serving as the focus of this review. PMID:20210551

  2. Brucella suis in armadillos (Chaetophractus villosus) from La Pampa, Argentina.

    PubMed

    Kin, Marta S; Fort, Marcelo; de Echaide, Susana T; Casanave, Emma B

    2014-06-01

    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. PMID:24685240

  3. Mechanisms of genome evolution of Streptococcus

    PubMed Central

    Andam, Cheryl P.; Hanage, William P.

    2014-01-01

    The genus Streptococcus contains 104 recognized species, many of which are associated with human or animal hosts. A globally prevalent human pathogen in this group is Streptococcus pneumoniae (the pneumococcus). While being a common resident of the upper respiratory tract, it is also a major cause of otitis media, pneumonia, bacteremia and meningitis, accounting for a high burden of morbidity and mortality worldwide. Recent findings demonstrate the importance of recombination and selection in driving the population dynamics and evolution of different pneumococcal lineages, allowing them to successfully evade the impacts of selective pressures such as vaccination and antibiotic treatment. We highlight the ability of pneumococci to respond to these pressures through processes including serotype replacement, capsular switching and horizontal gene transfer (HGT) of antibiotic resistance genes. The challenge in controlling this pathogen also lies in the exceptional genetic and phenotypic variation among different pneumococcal lineages, particularly in terms of their pathogenicity and resistance to current therapeutic strategies. The widespread use of pneumococcal conjugate vaccines, which target only a small subset of the more than 90 pneumococcal serotypes, provides us with a unique opportunity to elucidate how the processes of selection and recombination interact to generate a remarkable level of plasticity and heterogeneity in the pneumococcal genome. These processes also play an important role in the emergence and spread of multi-resistant strains, which continues to pose a challenge in disease control and/or eradication. The application of population of genomic approaches at different spatial and temporal scales will help improve strategies to control this global pathogen, and potentially other pathogenic streptococci. PMID:25461843

  4. Mechanisms of genome evolution of Streptococcus.

    PubMed

    Andam, Cheryl P; Hanage, William P

    2015-07-01

    The genus Streptococcus contains 104 recognized species, many of which are associated with human or animal hosts. A globally prevalent human pathogen in this group is Streptococcus pneumoniae (the pneumococcus). While being a common resident of the upper respiratory tract, it is also a major cause of otitis media, pneumonia, bacteremia and meningitis, accounting for a high burden of morbidity and mortality worldwide. Recent findings demonstrate the importance of recombination and selection in driving the population dynamics and evolution of different pneumococcal lineages, allowing them to successfully evade the impacts of selective pressures such as vaccination and antibiotic treatment. We highlight the ability of pneumococci to respond to these pressures through processes including serotype replacement, capsular switching and horizontal gene transfer (HGT) of antibiotic resistance genes. The challenge in controlling this pathogen also lies in the exceptional genetic and phenotypic variation among different pneumococcal lineages, particularly in terms of their pathogenicity and resistance to current therapeutic strategies. The widespread use of pneumococcal conjugate vaccines, which target only a small subset of the more than 90 pneumococcal serotypes, provides us with a unique opportunity to elucidate how the processes of selection and recombination interact to generate a remarkable level of plasticity and heterogeneity in the pneumococcal genome. These processes also play an important role in the emergence and spread of multi-resistant strains, which continues to pose a challenge in disease control and/or eradication. The application of population of genomic approaches at different spatial and temporal scales will help improve strategies to control this global pathogen, and potentially other pathogenic streptococci. PMID:25461843

  5. Phenotypic differentiation of Streptococcus intermedius, Streptococcus constellatus, and Streptococcus anginosus strains within the "Streptococcus milleri group".

    PubMed Central

    Whiley, R A; Fraser, H; Hardie, J M; Beighton, D

    1990-01-01

    A biochemical scheme was developed by which strains of Streptococcus constellatus, Streptococcus intermedius, and Streptococcus anginosus can reliably be distinguished from within the "Streptococcus milleri group." Strains identified as S. intermedius were differentiated by the ability to produce detectable levels of alpha-glucosidase, beta-galactosidase, beta-D-fucosidase, beta-N-acetylgalactosaminidase, beta-N-acetylglucosaminidase, and sialidase with 4-methylumbelliferyl-linked fluorogenic substrates in microdilution trays after 3 h of incubation at 37 degrees C, together with the production of hyaluronidase. Strains of S. constellatus and S. anginosus were differentiated by the production of alpha-glucosidase and hyaluronidase by the former and the production of beta-glucosidase by the latter. The majority of strains of the S. milleri group obtained from dental plaque were identified as S. intermedius, as were most strains isolated from abscesses of the brain and liver. Strains of S. constellatus and S. anginosus were from a wider variety of infections, both oral and nonoral, than were strains of S. intermedius, with the majority of strains from urogenital infections being identified as S. anginosus. PMID:2380375

  6. Value of UVJ-M in the diagnosis of SUI in late pregnancy and postpartum

    PubMed Central

    ZHANG, GUIXIN; JIANG, WEI; GUO, QUANWEI; GUO, QUANRONG

    2016-01-01

    Stress urinary incontinence (SUI) is a common pelvic floor dysfunctional disorder in which leakage of urine occurs when there is abdominal pressure. The aim of the present study was to determine the value of stress urinary incontinences (SUIs) in late pregnancy and postpartum via detection of the mobility of the ureterovesical junction (UVJ-M) by using transperineal ultrasound. The study involved the continuous and random selection of 120 cases of early pregnant women and single births. The patients were divided into the SUI and non-SUI groups dependent on whether there was leakage of urine when abdominal pressure in the form of coughing, laughing and sneezing, was increased. UVJ-M was measured, the receiver operating characteristic (ROC) curve was drawn up and the threshold value was predicted. The results showed that, the SUI prevalence was 7.5 (9/120), 22.5 (27/120), 43.3 (52/120), and 5.8% (7/100), respectively, in 34, 36, and 38 gestational weeks, and 6 weeks after delivery. The SUI prevalence gradually increased with the gestational weeks, and differences were statistically significant. UVJ-M values increased with the gestational weeks, at 3.43±1.52, 6.77±0.98 and 2.35±1.04 mm, respectively. Statistically significant differences were identified. Results of the ROC analysis, based on measurement of UVJ-M between the late pregnancy and non-SUI groups, revealed that the optimal threshold was 8.66 mm, corresponding to a sensitivity of 89.5% and specificity of 66.7%. In conclusion, UVJ-M ≥6.59 mm was identified as the predicted value of SUI during late pregnancy, and UVJ-M ≥8.66 mm the predicted value of SUI after delivery. PMID:27168801

  7. Risk factors for contacts between wild boar and outdoor pigs in Switzerland and investigations on potential Brucella suis spill-over

    PubMed Central

    2012-01-01

    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

  8. Lantibiotic production by pathogenic microorganisms.

    PubMed

    Daly, Karen M; Cotter, Paul D; Hill, Colin; Ross, R Paul

    2012-09-01

    Lantibiotics are ribosomally synthesised, post-translationally modified antimicrobial peptides produced by Gram positive bacteria, many which have broad-ranging antimicrobial activities. Lantibiotics have long been the subject of investigation with a view to their application as food preservatives or chemotherapeutic agents for clinical and veterinary medicine, while the associated biosynthetic machinery has been employed for peptide engineering purposes. However, although many lantibiotics are produced by generally regarded as safe or food-grade bacteria, it is increasingly apparent that a number of Gram positive pathogens, including strains of Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes, Streptococcus pneumoniae, Streptococcus mutans, Streptococcus uberis and Enterococcus faecalis, also produce these compounds. It is proposed that production of these antimicrobials may provide the associated microorganisms with a competitive advantage when colonizing/infecting a host, thereby enhancing the virulence of the producing strain. Here we review the production of lantibiotics by these pathogens and discuss how their production may contribute to their disease-causing potential. PMID:22708496

  9. Chlorophyll mediated photodynamic inactivation of blue laser on Streptococcus mutans

    NASA Astrophysics Data System (ADS)

    Astuti, Suryani Dyah; Zaidan, A.; Setiawati, Ernie Maduratna; Suhariningsih

    2016-03-01

    Photodynamic inactivation is an inactivation method in microbial pathogens that utilize light and photosensitizer. This study was conducted to investigate photodynamic inactivation effects of low intensity laser exposure with various dose energy on Streptococcus mutans bacteria. The photodynamic inactivation was achieved with the addition of chlorophyll as photosensitizers. To determine the survival percentage of Streptococcus mutans bacteria after laser exposure, the total plate count method was used. For this study, the wavelength of the laser is 405 nm and variables of energy doses are 1.44, 2.87, 4.31, 5.74, 7.18, and 8.61 in J/cm2. The results show that exposure to laser with energy dose of 7.18 J/cm2 has the best photodynamic inactivation with a decrease of 78% in Streptococcus

  10. Streptococcus agalactiae infection in zebrafish larvae

    PubMed Central

    Kim, Brandon J; Hancock, Bryan M; Cid, Natasha Del; Bermudez, Andres; Traver, David; Doran, Kelly S

    2015-01-01

    Streptococcus agalactiae (Group B Streptococcus, GBS) is an encapsulated, Gram-positive bacterium that is a leading cause of neonatal pneumonia, sepsis and meningitis, and an emerging aquaculture pathogen. The zebrafish (Danio rerio) is a genetically tractable model vertebrate that has been used to analyze the pathogenesis of both aquatic and human bacterial pathogens. We have developed a larval zebrafish model of GBS infection to study bacterial and host factors that contribute to disease progression. GBS infection resulted in dose dependent larval death, and GBS serotype III, ST-17 strain was observed as the most virulent. Virulence was dependent on the presence of the GBS capsule, surface anchored lipoteichoic acid (LTA) and toxin production, as infection with GBS mutants lacking these factors resulted in little to no mortality. Additionally, interleukin-1β il1b and CXCL-8 (cxcl8a) were significantly induced following GBS infection compared to controls. We also visualized GBS outside the brain vasculature, suggesting GBS penetration into the brain during the course of infection. Our data demonstrate that zebrafish larvae are a valuable model organism to study GBS pathogenesis. PMID:25617657

  11. Orientia, rickettsia, and leptospira pathogens as causes of CNS infections in Laos: a prospective study

    PubMed Central

    Dittrich, Sabine; Rattanavong, Sayaphet; Lee, Sue J; Panyanivong, Phonepasith; Craig, Scott B; Tulsiani, Suhella M; Blacksell, Stuart D; Dance, David A B; Dubot-Pérès, Audrey; Sengduangphachanh, Amphone; Phoumin, Phonelavanh; Paris, Daniel H; Newton, Paul N

    2015-01-01

    Summary Background Scrub typhus (caused by Orientia tsutsugamushi), murine typhus (caused by Rickettsia typhi), and leptospirosis are common causes of febrile illness in Asia; meningitis and meningoencephalitis are severe complications. However, scarce data exist for the burden of these pathogens in patients with CNS disease in endemic countries. Laos is representative of vast economically poor rural areas in Asia with little medical information to guide public health policy. We assessed whether these pathogens are important causes of CNS infections in Laos. Methods Between Jan 10, 2003, and Nov 25, 2011, we enrolled 1112 consecutive patients of all ages admitted with CNS symptoms or signs requiring a lumbar puncture at Mahosot Hospital, Vientiane, Laos. Microbiological examinations (culture, PCR, and serology) targeted so-called conventional bacterial infections (Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae, S suis) and O tsutsugamushi, Rickettsia typhi/Rickettsia spp, and Leptospira spp infections in blood or cerebrospinal fluid (CSF). We analysed and compared causes and clinical and CSF characteristics between patient groups. Findings 1051 (95%) of 1112 patients who presented had CSF available for analysis, of whom 254 (24%) had a CNS infection attributable to a bacterial or fungal pathogen. 90 (35%) of these 254 infections were caused by O tsutsugamushi, R typhi/Rickettsia spp, or Leptospira spp. These pathogens were significantly more frequent than conventional bacterial infections (90/1051 [9%] vs 42/1051 [4%]; p<0·0001) by use of conservative diagnostic definitions. CNS infections had a high mortality (236/876 [27%]), with 18% (13/71) for R typhi/Rickettsia spp, O tsutsugamushi, and Leptospira spp combined, and 33% (13/39) for conventional bacterial infections (p=0·076). Interpretation Our data suggest that R typhi/Rickettsia spp, O tsutsugamushi, and Leptospira spp infections are important causes of CNS infections in Laos

  12. Scabies Mites Alter the Skin Microbiome and Promote Growth of Opportunistic Pathogens in a Porcine Model

    PubMed Central

    Swe, Pearl M.; Zakrzewski, Martha; Kelly, Andrew; Krause, Lutz; Fischer, Katja

    2014-01-01

    Background The resident skin microbiota plays an important role in restricting pathogenic bacteria, thereby protecting the host. Scabies mites (Sarcoptes scabiei) are thought to promote bacterial infections by breaching the skin barrier and excreting molecules that inhibit host innate immune responses. Epidemiological studies in humans confirm increased incidence of impetigo, generally caused by Staphylococcus aureus and Streptococcus pyogenes, secondary to the epidermal infestation with the parasitic mite. It is therefore possible that mite infestation could alter the healthy skin microbiota making way for the opportunistic pathogens. A longitudinal study to test this hypothesis in humans is near impossible due to ethical reasons. In a porcine model we generated scabies infestations closely resembling the disease manifestation in humans and investigated the scabies associated changes in the skin microbiota over the course of a mite infestation. Methodology/Principal Findings In a 21 week trial, skin scrapings were collected from pigs infected with S. scabies var. suis and scabies-free control animals. A total of 96 skin scrapings were collected before, during infection and after acaricide treatment, and analyzed by bacterial 16S rDNA tag-encoded FLX-titanium amplicon pyrosequencing. We found significant changes in the epidermal microbiota, in particular a dramatic increase in Staphylococcus correlating with the onset of mite infestation in animals challenged with scabies mites. This increase persisted beyond treatment from mite infection and healing of skin. Furthermore, the staphylococci population shifted from the commensal S. hominis on the healthy skin prior to scabies mite challenge to S. chromogenes, which is increasingly recognized as being pathogenic, coinciding with scabies infection in pigs. In contrast, all animals in the scabies-free cohort remained relatively free of Staphylococcus throughout the trial. Conclusions/Significance This is the first

  13. Structure of N-acetyl-[beta]-D-glucosaminidase (GcnA) from the Endocarditis Pathogen Streptococcus gordonii and its Complex with the Mechanism-based Inhibitor NAG-thiazoline

    SciTech Connect

    Langley, David B.; Harty, Derek W.S.; Jacques, Nicholas A.; Hunter, Neil; Guss, J. Mitchell; Collyer, Charles A.

    2008-09-17

    The crystal structure of GcnA, an N-acetyl-{beta}-D-glucosaminidase from Streptococcus gordonii, was solved by multiple wavelength anomalous dispersion phasing using crystals of selenomethionine-substituted protein. GcnA is a homodimer with subunits each comprised of three domains. The structure of the C-terminal {alpha}-helical domain has not been observed previously and forms a large dimerization interface. The fold of the N-terminal domain is observed in all structurally related glycosidases although its function is unknown. The central domain has a canonical ({beta}/{alpha}){sub 8} TIM-barrel fold which harbours the active site. The primary sequence and structure of this central domain identifies the enzyme as a family 20 glycosidase. Key residues implicated in catalysis have different conformations in two different crystal forms, which probably represent active and inactive conformations of the enzyme. The catalytic mechanism for this class of glycoside hydrolase, where the substrate rather than the enzyme provides the cleavage-inducing nucleophile, has been confirmed by the structure of GcnA complexed with a putative reaction intermediate analogue, N-acetyl-{beta}-D-glucosamine-thiazoline. The catalytic mechanism is discussed in light of these and other family 20 structures.

  14. Experimental infections by Brucella suis type 4 in Alaskan rodents.

    PubMed

    Miller, L G; Neiland, K A

    1980-10-01

    The susceptibility of nine species of rodents and one species of lagomorph to Brucella suis type 4 was studied experimentally. The rodent species included: guinea pig (Cavia porcellus), Scandinavian lemming (Lemmus lemmus), brown lemming (L. sibiricus), northern red-backed vole (Clethrionomys rutilis), varying lemmings (Dicrostonyx stevensoni and D. rubricatus), yellow-cheeked vole (Microtus xanthognathus), flying squirrel (Glaucomys sabrinus) and ground squirrel (Citellus parryii). The lagomorph, Lepus americanus (varying hare), was also studied. All of these species were readily infected by intraperitoneal inoculations of brucellae. Pathologic responses were not marked in most of these species. However, both species of varying lemmings responded dramatically to infections initiated by about as few as two cfu. All individuals of both species that were not killed eventually died from the infection. PMID:7463596

  15. Biofilm formation in Streptococcus pneumoniae.

    PubMed

    Domenech, Mirian; García, Ernesto; Moscoso, Miriam

    2012-07-01

    Biofilm-grown bacteria are refractory to antimicrobial agents and show an increased capacity to evade the host immune system. In recent years, studies have begun on biofilm formation by Streptococcus pneumoniae, an important human pathogen, using a variety of in vitro model systems. The bacterial cells in these biofilms are held together by an extracellular matrix composed of DNA, proteins and, possibly, polysaccharide(s). Although neither the precise nature of these proteins nor the composition of the putative polysaccharide(s) is clear, it is known that choline-binding proteins are required for successful biofilm formation. Further, many genes appear to be involved, although the role of each appears to vary when biofilms are produced in batch or continuous culture. Prophylactic and therapeutic measures need to be developed to fight S. pneumoniae biofilm formation. However, much care needs to be taken when choosing strains for such studies because different S. pneumoniae isolates can show remarkable genomic differences. Multispecies and in vivo biofilm models must also be developed to provide a more complete understanding of biofilm formation and maintenance. PMID:21906265

  16. Biofilm formation in Streptococcus pneumoniae

    PubMed Central

    Domenech, Mirian; García, Ernesto; Moscoso, Miriam

    2012-01-01

    Summary Biofilm‐grown bacteria are refractory to antimicrobial agents and show an increased capacity to evade the host immune system. In recent years, studies have begun on biofilm formation by Streptococcus pneumoniae, an important human pathogen, using a variety of in vitro model systems. The bacterial cells in these biofilms are held together by an extracellular matrix composed of DNA, proteins and, possibly, polysaccharide(s). Although neither the precise nature of these proteins nor the composition of the putative polysaccharide(s) is clear, it is known that choline‐binding proteins are required for successful biofilm formation. Further, many genes appear to be involved, although the role of each appears to vary when biofilms are produced in batch or continuous culture. Prophylactic and therapeutic measures need to be developed to fight S. pneumoniae biofilm formation. However, much care needs to be taken when choosing strains for such studies because different S. pneumoniae isolates can show remarkable genomic differences. Multispecies and in vivo biofilm models must also be developed to provide a more complete understanding of biofilm formation and maintenance. PMID:21906265

  17. ThermiVa: The Revolutionary Technology for Vulvovaginal Rejuvenation and Noninvasive Management of Female SUI.

    PubMed

    Magon, Navneet; Alinsod, Red

    2016-08-01

    Addressing vaginal laxity, atrophic vaginitis, stress urinary incontinence (SUI), and different manifestations of sexual dysfunction has always been problematic due to women's traditional difficulty discussing these issues with doctors as well as the societal attitude of resignation toward these conditions. The recent rise of non-invasive feminine rejuvenation using energy-based modalities to vaginal tissue has its origins in aesthetic medicine. Transcutaneous temperature-controlled radiofrequency therapy at the vulvovaginal region has shown promising results in giving a more youthful appearing vulva, restoration of vaginal elasticity and 'tightness', considerable improvement in SUI, reduction in overactive bladder symptoms, and reduction in sexual dysfunction. It is also emerging as the non-invasive treatment modality for mild to moderate SUI. It seems that the time has come, when women shall ever be grateful to their gynecologist for management of SUI with ThermiVa without an incision. PMID:27382227

  18. Occurrence of Isospora suis in Germany, Switzerland and Austria.

    PubMed

    Mundt, H-C; Cohnen, A; Daugschies, A; Joachim, A; Prosl, H; Schmäschke, R; Westphal, B

    2005-03-01

    Nationwide surveys for the occurrence of Isospora suis were carried out in Germany, Austria and Switzerland including a questionnaire regarding herd size, health status and management practices and a coccidiosis sampling kit for pooled faecal samples from litters of suckling piglets. A total of 184 veterinary practices participated in the survey and returned 1745 samples (331 kits) from 324 farms in the north (n = 98), south (n = 84), centre/east (n = 42) and west (n = 10) of Germany, Austria (n = 61) and Switzerland (n = 29) with larger farms in north and centre/east (average number of sows: 270 and 500) and smaller ones in the south (95), Austria (60) and Switzerland (43). Larger farms tended to have better hygienic standards (slatted floors, disinfection of the farrowing units). The majority of the participating farms (93.5%) reported problems with diarrhoea in piglets at 2-3 weeks of age, significantly associated (P < 0.001) with uneven weaning weights (94.9%). Toltrazuril (5%; Baycox) was used only rarely; however, in these farms unevenness of weaning weights was less frequently observed (P = 0.011). A 76.2% of the farms were positive for I. suis (samples contained mostly low or moderate oocyst numbers), especially in the south (P < 0.001). Oocysts were more frequently found in samples from farms with reported diarrhoea (P = 0.011), uneven weight gain (P = 0.019) or in herds of small size (P < 0.001). Disinfection, floor type or treatment with toltrazuril did not affect the frequency of observation of oocysts. PMID:15752269

  19. Trichuris suis: thiol protease activity from adult worms.

    PubMed

    Hill, D E; Sakanari, J A

    1997-01-01

    Trichuris suis, the whipworm of swine, causes anemia, weight loss, anorexia, mucohemorrhagic diarrhea, and death in heavy infections. A zinc metalloprotease has been suggested to play a role in the severe enteric pathology associated with infection and the infiltration of opportunistic bacteria into deeper tissues in the swine colon. In this study, a thiol protease from gut extracts of adult T. suis and from excretory/secretory components (E/S) of adult worms was characterized using fluorogenic peptide substrates and protein substrate gels. The protease cleaved the fluorogenic substrate Z-Phe-Arg-AMC, and this cleavage was completely inhibited by the thiol protease inhibitors E-64, leupeptin, Z-Phe-Ala-CH2F, and Z-Phe-Arg-CH2F. Gelatin substrate gels and fluorescence assays using both the gut and the stichosome extracts and E/S revealed enhanced activity when 2 mM dithiothreitol or 5 mM cysteine was included in the incubation buffer, and optimal activity was seen over a pH range of 5.5 to 8.5. Incubation of gut extracts or E/S material with inhibitors of aspartic, serine, or metalloproteases had no effect on the cleavage of Z-Phe-Arg-AMC. Thiol protease activity was found in extracts of gut tissue but not in the extracts of stichocytes of adult worms. N-terminal amino acid sequencing of the protease revealed sequence homologies with cathepsin B-like thiol protease identified from parasitic and free-living nematodes. PMID:9024202

  20. First report of Brucella suis biovar 2 in a semi free-range pig farm, Italy.

    PubMed

    Barlozzari, Giulia; Franco, Alessia; Macrì, Gladia; Lorenzetti, Serena; Maggiori, Fabiana; Dottarelli, Samuele; Maurelli, Marina; Di Giannatale, Elisabetta; Tittarelli, Manuela; Battisti, Antonio; Gamberale, Fabrizio

    2015-01-01

    This communication describes the isolation of Brucella suis (B. suis) biovar 2 in semi‑free‑range pigs located in the province of Rome, Italy. Sera of 28 pigs from a herd with reproductive problems were tested for brucellosis. Twenty-five sera (89%) were found positive to Rose Bengal Test (RBT), while 22 (79%) were positive to Complement Fixation Test (CFT). Two positive pigs were slaughtered, organs were collected and tested for the presence of bacteria. Brucella spp. was isolated from the spleens and the abdominal lymph nodes of the 2 subjects. The isolates were identified as B. suis biovar 2 by biochemical and Polymerase Chain Reaction (PCR) tests. The frequent infringement in the fences of the premises and the birth of striped piglets provided evidence that sows mated with wild boar, the major reservoir of B. suis biovar 2. Conversely, the isolation of B. suis biovar 2 from spleens and lymphnodes of seropositive slaughtered animals only, as well as the constant negative results from all vaginal swabs and the abortion materials tested, raise doubts on the implication of B. suis biovar 2 in the infertility of the holding. PMID:26129667

  1. Interactive host cells related to Mycoplasma suis α-enolase by yeast two-hybrid analysis.

    PubMed

    Liu, Mingming; Jia, Lijun; Li, Jixu; Xue, Shujiang; Gao, Xu; Yu, Longzheng; Zhang, Shoufa

    2014-10-01

    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. PMID:25085536

  2. Bullous impetigo caused by Streptococcus salivarius: a case report.

    PubMed Central

    Brook, I

    1980-01-01

    A 19-month-old child presented with bullous impetigo around the perineal region, penis, and left foot. Streptococcus salivarius was the only isolate recovered from the lesions. The child was treated with parenteral penicillin, debridement of the bulli, and local application of silver sulphadiazine cream. This case of bullous impetigo illustrates another aspect of the pathogenicity of Strep. salivarius. Images Fig. 1 Fig. 2 PMID:7002959

  3. Age-related detection and molecular characterization of Cryptosporidium suis and Cryptosporidium scrofarum in pre- and post-weaned piglets and adult pigs in Japan.

    PubMed

    Yui, Takeshi; Nakajima, Toshiyuki; Yamamoto, Norishige; Kon, Marina; Abe, Niichiro; Matsubayashi, Makoto; Shibahara, Tomoyuki

    2014-01-01

    We investigated the distribution of Cryptosporidium in pigs in Japan by immunofluorescence staining of fecal samples and characterization of isolates by multilocus sequencing. The 344 animals sampled on eight farms included pre-weaned piglets (<1 month old; n = 55), weaned piglets (1-2 months old; n = 65), finished pigs (2-4 months old, n = 105) and of 4-6 months old (n = 67), sows (n = 36), and boars (n = 16). Average prevalence of Cryptosporidium on farms was 32.6%, ranging from 4.9 to 58.1%, decreasing with animal age (prevalences of <1 month old, 1-2 months old, 2-4 months old, 4-6 months old, sows, and boars were 27.3, 47.7, 41.9, 22.4, 11.1, 18.8%, respectively). Piglets (<1 and 1-2 months old) showing signs of diarrhea shed relatively more oocysts (5.28 in average log scale of oocysts per gram) in feces than piglets with normal or loose stools (those of 4.90). Thirty seven successful sequencing of the 18S ribosomal RNA gene among 62 examined samples revealed that all of the identified isolates were Cryptosporidium suis or Cryptosporidium scrofarum, which are generally specific to pigs, and that other species, such as zoonotic Cryptosporidium parvum, were absent. Interestingly, C. suis was frequently found in piglets younger than 2 months old, while C. scrofarum infection was more prevalent in older pigs which also showed increased prevalence of mixed C. suis and C. scrofarum infections. Sequencing of actin gene loci revealed the existence of variants of both Cryptosporidium species in pigs in Japan. Although the number of pigs examined in this study was relatively low, our results suggest that Cryptosporidium infection is widespread among pigs in Japan. In addition, the possibility of age-related specificity and pathogenicity in pig infections is also suggested. PMID:24189974

  4. STREPTOCOCCUS PHOCAE ISOLATED FROM A SPOTTED SEAL (PHOCA LARGHA) WITH PYOMETRA IN ALASKA

    PubMed Central

    Hueffer, Karsten; Lieske, Camilla L.; McGilvary, Lisa M.; Hare, Rebekah F.; Miller, Debra L.; O’Hara, Todd M.

    2013-01-01

    A spotted seal harvested by subsistence hunters in Kotzebue Sound, Alaska (USA), showed a grossly enlarged uterus and associated lymph nodes. Streptococcus phocae was isolated from the purulent uterine discharge. Histopathologic examination revealed inflammation that was limited to the uterine mucosa. Lymph nodes draining the affected organ were reactive but no evidence of active infection was found in the lymph nodes. This report is the first Streptococcus phocae isolated from spotted seals as well as the first report of pyometra as the main pathologic finding associated with this pathogen. Isolation of this pathogen from Alaska expands the reported range to arctic pinnipeds. Zoonotic potential remains unknown. PMID:22946378

  5. Phospholipids of Streptococcus faecalis

    PubMed Central

    Mota, J. M. dos Santos; Den Kamp, J. A. F. Op; Verheij, H. M.; Van Deenen, L. L. M.

    1970-01-01

    Autoradiograms of total lipid extracts from Streptococcus faecalis ATCC 9790, harvested in the stationary phase from a medium containing 32P-orthophosphate, showed six major spots. The corresponding compounds were identified as diphosphatidylglycerol (possibly with a penta acyl structure); phosphatidylglycerol; a provisionally identified mixture of alanylphosphatidylglycerol and of the 2′-lysyl-derivative of phosphatidylglycerol; the 3′-lysyl-derivative of phosphatidylglycerol, probably together with some arginylphosphatidylglycerol; a diglucosyl derivative of phosphatidylglycerol; and a compound which was tentatively identified as the 2′,3′-dilysyl derivative of phosphatidylglycerol. Images PMID:4321329

  6. "Adiós Sui Géneris": a study of the legal feasibility of the sui generis right in the context of research biobanks.

    PubMed

    Ducato, Rossana

    2013-01-01

    The European protection of databases has been criticized for having a negative impact on the scientific development and the process of discovery. In the paper it is checked whether one of the most important research infrastructures, such as biobanks, could be entitled with the sui generis right as shaped within the current European legal system. PMID:24340829

  7. Streptococcus pneumoniae NanC

    PubMed Central

    Owen, C. David; Lukacik, Petra; Potter, Jane A.; Sleator, Olivia; Taylor, Garry L.; Walsh, Martin A.

    2015-01-01

    Streptococcus pneumoniae is an important human pathogen that causes a range of disease states. Sialidases are important bacterial virulence factors. There are three pneumococcal sialidases: NanA, NanB, and NanC. NanC is an unusual sialidase in that its primary reaction product is 2-deoxy-2,3-didehydro-N-acetylneuraminic acid (Neu5Ac2en, also known as DANA), a nonspecific hydrolytic sialidase inhibitor. The production of Neu5Ac2en from α2–3-linked sialosides by the catalytic domain is confirmed within a crystal structure. A covalent complex with 3-fluoro-β-N-acetylneuraminic acid is also presented, suggesting a common mechanism with other sialidases up to the final step of product formation. A conformation change in an active site hydrophobic loop on ligand binding constricts the entrance to the active site. In addition, the distance between the catalytic acid/base (Asp-315) and the ligand anomeric carbon is unusually short. These features facilitate a novel sialidase reaction in which the final step of product formation is direct abstraction of the C3 proton by the active site aspartic acid, forming Neu5Ac2en. NanC also possesses a carbohydrate-binding module, which is shown to bind α2–3- and α2–6-linked sialosides, as well as N-acetylneuraminic acid, which is captured in the crystal structure following hydration of Neu5Ac2en by NanC. Overall, the pneumococcal sialidases show remarkable mechanistic diversity while maintaining a common structural scaffold. PMID:26370075

  8. Pelistega suis sp. nov., isolated from domestic and wild animals.

    PubMed

    Vela, Ana I; Perez Sancho, Marta; Domínguez, Lucas; Busse, Hans-Jürgen; Fernández-Garayzábal, Jose F

    2015-12-01

    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). PMID:26449759

  9. Native Valve Streptococcus bovis Endocarditis and Refractory Transfusion Dependent Iron Deficiency Anaemia Associated with Concomitant Carcinoma of the Colon: A Case Report and Review of the Literature.

    PubMed

    Ahamed Riyaaz, Abdul Azeez; Samarasinghe, Randula; Sellahewa, Kolitha; Sivakumaran, Sabaratnam; Tampoe, Manjula Sri

    2016-01-01

    Streptococcus bovis is found as a commensal organism in human gut and may become opportunistically pathogenic. Infective endocarditis is one of the commonest modes of presentation of this infection. The association between Streptococcus bovis endocarditis and colorectal cancer is well recognized. We report a case of Streptococcus bovis endocarditis along with a refractory iron deficiency anaemia associated with concomitant carcinoma of ascending colon in a 63-year-old male. Cooccurrence of these two conditions may cause a challenge in the management. Considering the strong association of colon cancer with Streptococcus bovis endocarditis, a detailed screening colonoscopy is mandatory following the diagnosis of the latter. PMID:26881154

  10. PATHOGENICITY AND IMMUNOGENICITY OF STREPTOMYCIN-DEPENDENT MUTANTS OF BRUCELLA

    PubMed Central

    Simon, Ellen M.; Berman, David T.

    1962-01-01

    Simon, Ellen M. (University of Wisconsin, Madison) and David T. Berman. Pathogenicity and immunogenicity of streptomycin-dependent mutants of Brucella. J. Bacteriol. 83:1347–1355. 1962.—Streptomycin-dependent (Sd) mutants of Brucella suis and B. abortus were avirulent for guinea pigs whether selected in the presence of streptomycin only or streptomycin and normal or immune serum. Administration of large quantities of streptomycin to guinea pigs increased the numbers of organisms which could be recovered, but did not cause the development of progressive infections. Vaccination with Sd mutants of B. abortus diminished the pathological response of guinea pigs infected with a large challenge dose of virulent B. abortus, but equal numbers of organisms were recovered from vaccinated animals and unvaccinated controls. Vaccination with Sd mutants of B. suis protected some guinea pigs from small challenge doses. Immunization by multiple injections or by one injection plus streptomycin was superior to a single inoculation of organisms. PMID:13913089

  11. Extended semen for artificial insemination in swine as a potential transmission mechanism for infectious Chlamydia suis.

    PubMed

    Hamonic, G; Pasternak, J A; Käser, T; Meurens, F; Wilson, H L

    2016-09-01

    Although typically unnoticed, Chlamydia infections in swine have been shown to be both widespread and may impact production characteristics and reproductive performance in swine. Serum titers suggest Chlamydia infection within boar studs is common, and infected boars are known to shed chlamydia in their ejaculates. Although the transmission of viruses in chilled extended semen (ES) is well established, the inclusion of antibiotics in commercially available extender is generally believed to limit or preclude the transmission of infectious bacteria. The objective of this study was to evaluate the potential of ES used in artificial insemination to support transmission of the obligate intracellular bacteria Chlamydia suis (C suis) under standard industry conditions. First, the effect of C suis on sperm quality during storage was assessed by flow cytometry. Only concentrations above 5 × 10(5) viable C suis/mL caused significant spermicidal effects which only became evident after 7 days of storage at 17 °C. No significant effect on acrosome reaction was observed using any chlamydial concentration. Next, an in vitro infection model of swine testicular fibroblast cells was established and used to evaluate the effect of chilled storage on C suis viability under variable conditions. Storage in Androhep ES reduced viability by 34.4% at a multiplicity of infection of 1.25, an effect which increased to 53.3% when the multiplicity of infection decreased to 0.1. Interestingly, storage in semen extender alone (SE) or ES with additional antibiotics had no effect on bacterial viability. To rule out a secondary effect on extender resulting from metabolically active sperm, C suis was stored in fresh and expended SE and again no significant effect on bacterial viability was observed. Fluorescent microscopy of C suis in ES shows an association between bacteria and the remaining gel fraction after storage suggesting that the apparent reduction of bacterial viability in the presence

  12. Characterization of Arcobacter suis isolated from water buffalo (Bubalus bubalis) milk.

    PubMed

    Giacometti, Federica; Salas-Massó, Nuria; Serraino, Andrea; Figueras, Maria José

    2015-10-01

    During a survey in a dairy plant in Italy, the second strain (strain FG 206) of Arcobacter suis described in the literature was isolated from raw water buffalo milk. The objective of this study was to confirm the species identification, better define the species by comparing its characteristics with those of the reference strain (F41(T) = CECT 7833(T) = LMG 26152(T)) and to investigate its potential clinical relevance by detecting the virulence gene pattern of the new strain. Phenotypical characterization and 16S rRNA-RFLP gave a complete overlap of results for the two strains. As expected, an RFLP pattern common to A. suis and Arcobacter defluvii was obtained by MseI endonuclease digestion, and a pattern specific for A. suis was obtained by BfaI endonuclease digestion. 16S rRNA sequencing and multilocus phylogenetic analysis (MLPA) showed a robust relatedness of strain FG 206 to the A. suis type strain F41(T). The recovery of strain FG 206 from a dairy plant shows that this species of Arcobacter is present in the food chain. Like the type strain recovered from pig meat, the species A. suis may not be confined to a single type of food. PMID:26187844

  13. Study on bioactive compounds of in vitro cultured Calculus Suis and natural Calculus Bovis.

    PubMed

    Wan, Tien-Chun; Cheng, Fu-Yuan; Liu, Yu-Tse; Lin, Liang-Chuan; Sakata, Ryoichi

    2009-12-01

    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. PMID:20163661

  14. Udder infections with Staphylococcus aureus, Streptococcus dysgalactiae, and Streptococcus uberis at calving in dairy herds with suboptimal udder health.

    PubMed

    Lundberg, Å; Nyman, A-K; Aspán, A; Börjesson, S; Unnerstad, H Ericsson; Waller, K Persson

    2016-03-01

    Udder infections with Staphylococcus aureus, Streptococcus dysgalactiae, and Streptococcus uberis are common causes of bovine mastitis. To study these pathogens in early lactation, a 12-mo longitudinal, observational study was carried out in 13 herds with suboptimal udder health. The aims of the study were to investigate the occurrence of these pathogens and to identify if presence of the 3 pathogens, and of genotypes within the pathogens, differed with respect to herd, season, and parity. Quarter milk samples, collected at calving and 4 d in milk (DIM), were cultured for the 3 pathogens. Genotyping of staphylococcal and streptococcal isolates was performed using spa typing and pulsed-field gel electrophoresis, respectively. For each of the 3 pathogens, cows with an udder infection at calving or 4 DIM were allocated to 1 of 4 infection types: cleared (pathogen present only at calving), persistent (pathogen present in the same quarter at calving and 4 DIM), new (pathogen present only at 4 DIM), or cleared/new (pathogen present in 1 quarter at calving and in another quarter at 4 DIM). Associations between season or parity and overall occurrence of pathogens or infection types were determined using univariable mixed-effect logistic-regression models and the Fisher's exact test, respectively. The most commonly occurring pathogen was Staph. aureus, followed by Strep. dysgalactiae and Strep. uberis. Persistent infections were the most common infection type among Staph. aureus-infected cows, whereas cleared infections were the most common among Strep. dysgalactiae- and Strep. uberis-positive cows. The proportion of cows with persistent Staph. aureus infections and the proportion of cows having a Strep. uberis infection at calving or 4 DIM were higher in the multiparous cows than in primiparous cows. Infections with Strep. dysgalactiae were less common during the early housing season than during the late housing or pasture seasons, whereas persistent Strep. uberis

  15. Phylogenomic analysis of natural selection pressure in Streptococcus genomes

    PubMed Central

    Anisimova, Maria; Bielawski, Joseph; Dunn, Katherine; Yang, Ziheng

    2007-01-01

    Background In comparative analyses of bacterial pathogens, it has been common practice to discriminate between two types of genes: (i) those shared by pathogens and their non-pathogenic relatives (core genes), and (ii) those found exclusively in pathogens (pathogen-specific accessory genes). Rather than attempting to a priori delineate genes into sets more or less relevant to pathogenicity, we took a broad approach to the analysis of Streptococcus species by investigating the strength of natural selection in all clusters of homologous genes. The genus Streptococcus is comprised of a wide variety of both pathogenic and commensal lineages, and we relate our findings to the pre-existing knowledge of Streptococcus virulence factors. Results Our analysis of 1730 gene clusters revealed 136 cases of positive Darwinian selection, which we suggest is most likely to result from an antagonistic interaction between the host and pathogen at the molecular level. A two-step validation procedure suggests that positive selection was robustly identified in our genomic survey. We found no evidence to support the notion that pathogen specific accessory genes are more likely to be subject to positive selection than core genes. Indeed, we even uncovered a few cases of essential gene evolution by positive selection. Among the gene clusters subject to positive selection, a large fraction (29%) can be connected to virulence. The most striking finding was that a considerable fraction of the positively selected genes are also known to have tissue specific patterns of expression during invasive disease. As current expression data is far from comprehensive, we suggest that this fraction was underestimated. Conclusion Our findings suggest that pathogen specific genes, although a popular focus of research, do not provide a complete picture of the evolutionary dynamics of virulence. The results of this study, and others, support the notion that the products of both core and accessory genes

  16. Streptococcus pneumoniae: virulence factors, pathogenesis, and vaccines.

    PubMed Central

    AlonsoDeVelasco, E; Verheul, A F; Verhoef, J; Snippe, H

    1995-01-01

    Although pneumococcal conjugate vaccines are close to being licensed, a more profound knowledge of the virulence factors responsible for the morbidity and mortality caused by Streptococcus pneumoniae is necessary. This review deals with the major structures of pneumococci involved in the pathogenesis of pneumococcal disease and their interference with the defense mechanisms of the host. It is well known that protection against S. pneumoniae is the result of phagocytosis of invading pathogens. For this process, complement and anticapsular polysaccharide antibodies are required. Besides, relatively recent experimental data suggest that protection is also mediated by the removal of disintegrating pneumococci and their degradation products (cell wall, pneumolysin). These structures seem to be major contributors to illness and death caused by pneumococci. An effective conjugate vaccine should therefore preferably include the capsular polysaccharide and at least one of these inflammatory factors. PMID:8531887

  17. Identification of Streptococcus bovis and Streptococcus salivarius in clinical laboratories.

    PubMed Central

    Ruoff, K L; Ferraro, M J; Holden, J; Kunz, L J

    1984-01-01

    Streptococci identified as Streptococcus bovis, S. bovis variant, and Streptococcus salivarius were examined with respect to physiological and serological characteristics and cellular fatty acid content. Similarities in physiological reactions and problems encountered in serological analysis were noted, suggesting that an expanded battery of physiological tests is needed to definitively identify these streptococci. Cellular fatty acid analysis provided an accurate method for distinguishing S. salivarius from S. bovis and S. bovis variant. PMID:6490816

  18. Genetic Manipulation of Streptococcus pyogenes (The Group A Streptococcus, GAS)

    PubMed Central

    Le Breton, Yoann; McIver, Kevin S.

    2013-01-01

    Streptococcus pyogenes (the group A streptococcus, GAS) is a Gram-positive bacterium responsible for a wide spectrum of diseases ranging from mild superficial infections (pharyngitis, impetigo) to severe often life-threatening invasive diseases (necrotizing fasciitis, streptococcal toxic shock syndrome) in humans. This unit describes molecular techniques for the genetic manipulation of S. pyogenes with detailed protocols for transformation, gene disruption, allelic exchange, transposon mutagenesis, and genetic complementation. PMID:24510894

  19. Genetic manipulation of Streptococcus pyogenes (the Group A Streptococcus, GAS).

    PubMed

    Le Breton, Yoann; McIver, Kevin S

    2013-01-01

    Streptococcus pyogenes (the Group A Streptococcus, GAS) is a Gram-positive bacterium responsible for a wide spectrum of diseases ranging from mild superficial infections (pharyngitis, impetigo) to severe, often life-threatening invasive diseases (necrotizing fasciitis, streptococcal toxic shock syndrome) in humans. This unit describes molecular techniques for the genetic manipulation of S. pyogenes with detailed protocols for transformation, gene disruption, allelic exchange, transposon mutagenesis, and genetic complementation. PMID:24510894

  20. Structure of the lipopolysaccharide isolated from the novel species Uruburuella suis.

    PubMed

    Silipo, Alba; Sturiale, Luisa; De Castro, Cristina; Lanzetta, Rosa; Parrilli, Michelangelo; Garozzo, Domenico; Molinaro, Antonio

    2012-08-01

    Uruburuella suis is a novel species isolated from lungs and heart of pigs with pneumonia and pericarditis. Phenotypic and phylogenetic evidences showed that it represented a hitherto unknown subline within the family Neisseriaceae. In the present work we defined the whole structure of the LPS isolated from Uruburuella suis. The structural determination, which was achieved by chemical, spectroscopic and spectrometric approaches, indicates a novel rough type lipopolysaccharide rich in negatively charged groups in the lipid A-inner core region. The elucidation of the structural features of the LPS from Uruburuella suis is a first step toward the comprehension of the characteristics of the cell envelope in such new and interesting microorganisms. PMID:22704198

  1. The development and survival of Trichuris suis ova on pasture plots in the south of England.

    PubMed

    Burden, D J; Hammet, N C

    1979-01-01

    Pasture plots in the south of England were contaminated each month throughout 1975 with pig faeces containing Trichuris suis ova. At regular intervals thereafter, soil samples were taken, the T suis ova extracted and their state of development noted. Depending on the time of year that the plots were contaminated, ova required between 62 and 90 weeks to complete their development to the infective stage. Little or no development occurred during winter. Once the infective stage was reached, the ova survived for at least two years. Samples taken from the plots at various depths demonstrated that T suis ova did not rapidly leach through the soil but were still available to grazing pigs up to two and a half years later. The early developmental stages of ova appeared to be more susceptible to desiccation than those that had developed to the blastula stage or beyond. PMID:572984

  2. Mutacins of Streptococcus mutans

    PubMed Central

    Kamiya, Regianne Umeko; Taiete, Tiago; Gonçalves, Reginaldo Bruno

    2011-01-01

    The colonization and accumulation of Streptococcus mutans are influenced by various factors in the oral cavity, such as nutrition and hygiene conditions of the host, salivary components, cleaning power and salivary flow and characteristics related with microbial virulence factors. Among these virulence factors, the ability to synthesize glucan of adhesion, glucan-binding proteins, lactic acid and bacteriocins could modify the infection process and pathogenesis of this species in the dental biofilm. This review will describe the role of mutacins in transmission, colonization, and/or establishment of S. mutans, the major etiological agent of human dental caries. In addition, we will describe the method for detecting the production of these inhibitory substances in vitro (mutacin typing), classification and diversity of mutacins and the regulatory mechanisms related to its synthesis. PMID:24031748

  3. Molecular identification of Trichuris vulpis and Trichuris suis isolated from different hosts.

    PubMed

    Cutillas, Cristina; de Rojas, Manuel; Ariza, Concepción; Ubeda, José Manuel; Guevara, Diego

    2007-01-01

    Trichuris suis was isolated from the cecum of two different hosts (Sus scrofa domestica -- swine and Sus scrofa scrofa -- wild boar) and Trichuris vulpis from dogs in Sevilla, Spain. Genomic DNA was isolated and internal transcribed spacers (ITS)1-5.8S-ITS2 segment from the ribosomal DNA (rDNA) was amplified and sequenced using polymerase chain reaction techniques. The sequence of T. suis from both hosts was 1,396 bp in length while that of T. vulpis was 1,044 bp. ITS1 of both populations isolated of T. suis was 661 nucleotides in length, while the ITS2 was 534 nucleotides in length. Furthermore, the ITS1 of T. vulpis was 410 nucleotides in length, while the ITS2 was 433 nucleotides in length. One hundred fifty-four nucleotides were observed along the 5.8S gene of T. suis and T. vulpis. Intraindividual and intraspecific variations were detected in the rDNA of both species. The presence of microsatellites was observed in all the individuals assayed. Sequence analysis of the ITSs and the 5.8S gene has demonstrated no sequence differences between T. suis isolated from both hosts (S. scrofa domestica -- swine and S. scrofa scrofa -- wild boar). Nevertheless, clear differences were detected between the ITS1 and ITS2 of T. suis and T. vulpis. Furthermore, a comparative molecular analysis between both species and the previously published ITS1-5.8S-ITS2 sequence data of Trichuris ovis, Trichuris leporis, Trichuris muris, Trichuris arvicolae, and Trichuris skrjabini was carried out. A common homology zone was detected in the ITS1 sequence of all species of trichurids. PMID:17004099

  4. Lipoproteins of bacterial pathogens.

    PubMed

    Kovacs-Simon, A; Titball, R W; Michell, S L

    2011-02-01

    Bacterial lipoproteins are a set of membrane proteins with many different functions. Due to this broad-ranging functionality, these proteins have a considerable significance in many phenomena, from cellular physiology through cell division and virulence. Here we give a general overview of lipoprotein biogenesis and highlight examples of the roles of lipoproteins in bacterial disease caused by a selection of medically relevant Gram-negative and Gram-positive pathogens: Mycobacterium tuberculosis, Streptococcus pneumoniae, Borrelia burgdorferi, and Neisseria meningitidis. Lipoproteins have been shown to play key roles in adhesion to host cells, modulation of inflammatory processes, and translocation of virulence factors into host cells. As such, a number of lipoproteins have been shown to be potential vaccines. This review provides a summary of some of the reported roles of lipoproteins and of how this knowledge has been exploited in some cases for the generation of novel countermeasures to bacterial diseases. PMID:20974828

  5. Cross-sectional study of Streptococcus species in quarter milk samples of dairy cows in the canton of Bern, Switzerland.

    PubMed

    Guélat-Brechbuehl, M; Thomann, A; Albini, S; Moret-Stalder, S; Reist, M; Bodmer, M; Michel, A; Niederberger, M D; Kaufmann, T

    2010-08-01

    A total of 2538 quarter milk samples from 638 lactating dairy cows from 47 farms in the canton of Bern, Switzerland, were investigated for streptococci. A novel, simple and inexpensive laboratory method was used for the differentiation of Streptococcus species, and a risk factor analysis was carried out. The prevalence in the quarter milk samples was 0.2 per cent for Streptococcus agalactiae, 1.3 per cent for Streptococcus uberis, 1.3 per cent for Streptococcus dysgalactiae, 0.1 per cent for Enterococcus species and 2.9 per cent for minor Streptococcus species (designated Streptococcus-Lactococcus-Enterococcus [SLE] group). Based on the somatic cell count (SCC), S uberis and S dysgalactiae were classified as 'major' pathogens and the bacteria in the SLE group as 'minor' pathogens. For S uberis, S dysgalactiae and bacteria in the SLE group, the most significant risk factor was an intramammary infection (IMI) of a neighbouring quarter by the same pathogen. Other significant risk factors for S uberis infection were a positive California Mastitis Test (CMT) result and a SCC of more than 100,000 cells/ml. Significant risk factors for IMI with S dysgalactiae were a positive CMT result, teat injury and palpable abnormalities in the udder. Infection with bacteria in the SLE group was significantly associated with a SCC of more than 100,000 cells/ml, a lactation number of more than 2, the right rear quarter (as the location of infection) and a positive CMT result. PMID:20693505

  6. Complete Genome Sequence of Streptococcus agalactiae Strain S25 Isolated from Peritoneal Liquid of Nile Tilapia

    PubMed Central

    Mainardi, Rafaella Menegheti; Lima Júnior, Edson Antônio; Ribeiro Júnior, Jose Carlos; Beloti, Vanerli; Carmo, Anderson Oliveira; Kalapothakis, Evanguedes; Gonçalves, Daniela Dib; Padua, Santiago Benites

    2016-01-01

    Streptococcus agalactiae (Lancefield group B; GBS) is one of the major pathogens in fish production, especially in Nile tilapia (Oreochromis niloticus). The genomic characteristics of GBS isolated from fish must be more explored. Thus, we present here the genome of GBS S25, isolated from Nile tilapia from Brazil. PMID:27491974

  7. Draft Genome Sequences of Streptococcus agalactiae Serotype Ia and III Isolates from Tilapia Farms in Thailand.

    PubMed

    Areechon, Nontawith; Kannika, Korntip; Hirono, Ikuo; Kondo, Hidehiro; Unajak, Sasimanas

    2016-01-01

    Streptococcus agalactiaeserotypes Ia and III were isolated from infected tilapia in cage and pond culture farms in Thailand during 2012 to 2014, in which pathogenicity analysis demonstrated that serotype III showed higher virulence than serotype Ia. Here, we report the draft genome sequencing of piscineS. agalactiaeserotypes Ia and III. PMID:27013037

  8. Specific serum antibody responses in channel catfish (Ictalurus punctatus) provide limited protection against Streptococcus ictaluri challenge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Passive immunization has been shown to provide a spectrum of protection against certain piscine pathogens, and studies were conducted to determine the role of specific antibodies in immunity to Streptococcus ictaluri. Adult Nile tilapia (Oreochromis niloticus) were injected i.p. with tryptic soy br...

  9. New Tricks from an Old Cow: Infective Endocarditis Caused by Streptococcus dysgalactiae subsp. dysgalactiae

    PubMed Central

    Jordal, Stina; Glambek, Marte; Oppegaard, Oddvar

    2014-01-01

    We present a case of infective endocarditis caused by Streptococcus dysgalactiae subsp. dysgalactiae, a major cause of bovine mastitis and previously thought to be an animal-restricted pathogen. The patient reported no direct contact with animals, and the clinical course was severe and complicated. PMID:25472489

  10. Multidrug-resistant viridans streptococcus (MDRVS) osteomyelitis of the mandible successfully treated with moxifloxacin.

    PubMed

    Ang, Jocelyn Y; Asmar, Basim I

    2008-05-01

    Multidrug-resistant viridans group streptococcus (MDRVS) strains have emerged as important pathogens. Treatment of MDRVS infections is problematic. The use of fluoroquinolones for treatment of MDRVS osteomyelitis has not been established. We present the first case of MDRVS osteomyelitis of the mandible successfully treated with sequential intravenous then oral moxifloxacin, and review the literature on the subject. PMID:18414152

  11. Complete genome sequence of Streptococcus equi subsp. zooepidemicus strain ATCC 35246.

    PubMed

    Ma, Zhe; Geng, Jianing; Zhang, Hui; Yu, Haiying; Yi, Li; Lei, Meng; Lu, Cheng-ping; Fan, Hong-jie; Hu, Songnian

    2011-10-01

    Streptococcus equi subsp. zooepidemicus is an opportunistic pathogen. It has caused a very large economic loss in the swine industry of China and has become a threat to human health. We announce the complete genome sequence of S. equi subsp. zooepidemicus strain ATCC 35246, which provides opportunities to understand its pathogenesis mechanism and genetic basis. PMID:21914890

  12. Immunoproteomic analysis of the antibody response obtained in tilapia following immunization with a Streptococcus iniae vaccine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus iniae is one of the most economically important Gram-positive pathogens in cultured fish species worldwide. Research has shown that vaccination is a tool that can be used in the prevention of streptococcal disease. The USDA-ARS patented S. iniae vaccine has been demonstrated to be ef...

  13. Complete Genome Sequence of Streptococcus agalactiae Strain S25 Isolated from Peritoneal Liquid of Nile Tilapia.

    PubMed

    Mainardi, Rafaella Menegheti; Lima Júnior, Edson Antônio; Ribeiro Júnior, Jose Carlos; Beloti, Vanerli; Carmo, Anderson Oliveira; Kalapothakis, Evanguedes; Gonçalves, Daniela Dib; Padua, Santiago Benites; Pereira, Ulisses Pádua

    2016-01-01

    Streptococcus agalactiae (Lancefield group B; GBS) is one of the major pathogens in fish production, especially in Nile tilapia (Oreochromis niloticus). The genomic characteristics of GBS isolated from fish must be more explored. Thus, we present here the genome of GBS S25, isolated from Nile tilapia from Brazil. PMID:27491974

  14. Identification and Epidemiology of Streptococcus iniae and S. agalactiae in tilapias Oreochromis spp.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite being known mainly as mammalian disease agents, Streptococcus iniae and S. agalactiae have become recognized as emerging pathogens of wild and cultured fish. The worldwide economic impact of S. iniae and S. agalactiae to the aquaculture industry is estimated in hundreds of millions annually...

  15. Protection against heterologous Streptococcus iniae isolates using a modified bacterin vaccine in Nile tilapia Oreochromis niloticus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus iniae is an important pathogen of both wild and cultured fish worldwide. Losses are estimated in the hundreds of million dollars annually in cultured fish. The objectives of this study were to determine if a developed modified S. iniae bacterin vaccine was efficacious against heterol...

  16. Draft Genome Sequences of Streptococcus agalactiae Serotype Ia and III Isolates from Tilapia Farms in Thailand

    PubMed Central

    Areechon, Nontawith; Kannika, Korntip; Hirono, Ikuo

    2016-01-01

    Streptococcus agalactiae serotypes Ia and III were isolated from infected tilapia in cage and pond culture farms in Thailand during 2012 to 2014, in which pathogenicity analysis demonstrated that serotype III showed higher virulence than serotype Ia. Here, we report the draft genome sequencing of piscine S. agalactiae serotypes Ia and III. PMID:27013037

  17. Prevalence of Bovine Mastitis Pathogens in Bulk Tank Milk in China

    PubMed Central

    Wang, Ya Jing; Qin, Yun; Guix Vallverdú, Roger; Maldonado García, Jaime; Sun, Wei; Li, Shengli; Cao, Zhijun

    2016-01-01

    The objectives of this study were to estimate the herd prevalence of major mastitis pathogens in bulk tank milk (BTM) in China dairy herds, to determine the relationship between the presence of mastitis pathogens and bulk tank milk somatic cell counts (BTSCC), and to investigate the impact of different dairy cattle farming modes and region on bacterial species. BTM samples collected from 894 dairy herds in China were examined for the presence of mastitis pathogens. The Flinders Technology Associates (FTA) cards were used for BTM sample collection, storage, and transportation and bacterial DNA amplification by real-time PCR. Among contagious pathogens, Staphylococcus aureus, Streptococcus agalactiae, and Streptococcus dysgalactiae were detected in 50.1, 92.2, and 72.3% of the 894 BTM samples, respectively. Among environmental pathogens, E. coli, Streptococcus uberis, Enterococcus spp., Klebsiella spp., Serratia marcescens, Corynebacterium bovis, and Arcanobacterium pyogenes were detected in 28.6, 8.9, 35.7, 20.0, 1.3, 17.0, and 67.2% of the BTM samples, respectively. Staphylococcal β-lactamase gene was detected in 61.7% of the BTM samples. The presence of Staphylococcus aureus and Arcanobacterium pyogenes were significantly associated with high BTSCC, respectively. Significant differences were found in presence of Staphylococcus aureus, Streptococcus agalactiae, and Streptococcus dysgalactiae in BTM sampled from the small household farms, dairy-farming communities, and large-scaled dairy farms. There were significant differences in the presence of Streptococcus agalactiae, Streptococcus dysgalactiae, Arcanobacterium pyogenes, staphylococcal β-lactamase gene, Staphylococcus spp., Klebsiella spp., Enterococcus spp., and Streptococcus uberis in BTM among Inner Mongolia, Heilongjiang, and Hebei province. In conclusion, contagious mammary pathogens are predominated among pathogens in BTM samples in China. PMID:27187065

  18. Prevalence of Bovine Mastitis Pathogens in Bulk Tank Milk in China.

    PubMed

    Bi, Yanliang; Wang, Ya Jing; Qin, Yun; Guix Vallverdú, Roger; Maldonado García, Jaime; Sun, Wei; Li, Shengli; Cao, Zhijun

    2016-01-01

    The objectives of this study were to estimate the herd prevalence of major mastitis pathogens in bulk tank milk (BTM) in China dairy herds, to determine the relationship between the presence of mastitis pathogens and bulk tank milk somatic cell counts (BTSCC), and to investigate the impact of different dairy cattle farming modes and region on bacterial species. BTM samples collected from 894 dairy herds in China were examined for the presence of mastitis pathogens. The Flinders Technology Associates (FTA) cards were used for BTM sample collection, storage, and transportation and bacterial DNA amplification by real-time PCR. Among contagious pathogens, Staphylococcus aureus, Streptococcus agalactiae, and Streptococcus dysgalactiae were detected in 50.1, 92.2, and 72.3% of the 894 BTM samples, respectively. Among environmental pathogens, E. coli, Streptococcus uberis, Enterococcus spp., Klebsiella spp., Serratia marcescens, Corynebacterium bovis, and Arcanobacterium pyogenes were detected in 28.6, 8.9, 35.7, 20.0, 1.3, 17.0, and 67.2% of the BTM samples, respectively. Staphylococcal β-lactamase gene was detected in 61.7% of the BTM samples. The presence of Staphylococcus aureus and Arcanobacterium pyogenes were significantly associated with high BTSCC, respectively. Significant differences were found in presence of Staphylococcus aureus, Streptococcus agalactiae, and Streptococcus dysgalactiae in BTM sampled from the small household farms, dairy-farming communities, and large-scaled dairy farms. There were significant differences in the presence of Streptococcus agalactiae, Streptococcus dysgalactiae, Arcanobacterium pyogenes, staphylococcal β-lactamase gene, Staphylococcus spp., Klebsiella spp., Enterococcus spp., and Streptococcus uberis in BTM among Inner Mongolia, Heilongjiang, and Hebei province. In conclusion, contagious mammary pathogens are predominated among pathogens in BTM samples in China. PMID:27187065

  19. Activity of Faropenem against Middle Ear Fluid Pathogens from Children with Acute Otitis Media in Costa Rica and Israel▿

    PubMed Central

    Stone, Kimberley Clawson; Dagan, Ron; Arguedas, Adriano; Leibovitz, Eugene; Wang, Elaine; Echols, Roger M.; Janjic, Nebojsa; Critchley, Ian A.

    2007-01-01

    Faropenem was tested against 1,188 middle ear fluid pathogens from children in Israel and Costa Rica. Against Streptococcus pneumoniae and Haemophilus influenzae, faropenem was the most active β-lactam, with activity that was similar to or greater than of the other oral antimicrobial classes studied. Faropenem was also active against Moraxella catarrhalis and Streptococcus pyogenes. PMID:17387157

  20. Activity of faropenem against middle ear fluid pathogens from children with acute otitis media in Costa Rica and Israel.

    PubMed

    Stone, Kimberley Clawson; Dagan, Ron; Arguedas, Adriano; Leibovitz, Eugene; Wang, Elaine; Echols, Roger M; Janjic, Nebojsa; Critchley, Ian A

    2007-06-01

    Faropenem was tested against 1,188 middle ear fluid pathogens from children in Israel and Costa Rica. Against Streptococcus pneumoniae and Haemophilus influenzae, faropenem was the most active beta-lactam, with activity that was similar to or greater than of the other oral antimicrobial classes studied. Faropenem was also active against Moraxella catarrhalis and Streptococcus pyogenes. PMID:17387157

  1. High-Level Fluorescence Labeling of Gram-Positive Pathogens

    PubMed Central

    Aymanns, Simone; Mauerer, Stefanie; van Zandbergen, Ger; Wolz, Christiane; Spellerberg, Barbara

    2011-01-01

    Fluorescence labeling of bacterial pathogens has a broad range of interesting applications including the observation of living bacteria within host cells. We constructed a novel vector based on the E. coli streptococcal shuttle plasmid pAT28 that can propagate in numerous bacterial species from different genera. The plasmid harbors a promoterless copy of the green fluorescent variant gene egfp under the control of the CAMP-factor gene (cfb) promoter of Streptococcus agalactiae and was designated pBSU101. Upon transfer of the plasmid into streptococci, the bacteria show a distinct and easily detectable fluorescence using a standard fluorescence microscope and quantification by FACS-analysis demonstrated values that were 10–50 times increased over the respective controls. To assess the suitability of the construct for high efficiency fluorescence labeling in different gram-positive pathogens, numerous species were transformed. We successfully labeled Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus dysgalactiae subsp. equisimilis, Enterococcus faecalis, Enterococcus faecium, Streptococcus mutans, Streptococcus anginosus and Staphylococcus aureus strains utilizing the EGFP reporter plasmid pBSU101. In all of these species the presence of the cfb promoter construct resulted in high-level EGFP expression that could be further increased by growing the streptococcal and enterococcal cultures under high oxygen conditions through continuous aeration. PMID:21731607

  2. Complete Genome Sequences of Three Iberian Brucella suis Biovar 2 Strains Isolated from Wild Boars

    PubMed Central

    Ferreira, Ana Cristina; Tenreiro, Rogério; Corrêa de Sá, Maria Inácia

    2014-01-01

    Brucella suis biovar 2 is the most common biovar isolated from wild boars (Sus scrofa) associated with transmission to outdoor-reared pigs in Europe. We report here the complete and annotated genome sequences of three strains isolated from wild boars in Portugal and Spain and belonging to the Iberian clone (haplotypes 2d and 2e). PMID:24994794

  3. Immuogenicity and safety of a natural rough mutant of Brucella suis as a vaccine for swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  4. Worm burden-dependent disruption of the porcine colon microbiota by Trichuris suis infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  5. Worm burden-dependent disruption of the porcine colon microbiota by Trichuris suis infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  6. Chao Yuanfang: Imperial Physician of the Sui Dynasty and an Early Pertussis Observer?

    PubMed Central

    Liang, Yan; Salim, Abdulbaset M.; Wu, Wendy; Kilgore, Paul E.

    2016-01-01

    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

  7. Genome Sequences of Brucella abortus and Brucella suis Strains Isolated from Bovine in Zimbabwe

    PubMed Central

    Ledwaba, Betty; Mafofo, Joseph

    2014-01-01

    This is a report of whole-genome sequences of a Brucella abortus strain and two Brucella suis strains isolated from bovine in Zimbabwe. These strains were selected based on their origin and data obtained when using multiplex PCR assays, then sequenced using next-generation sequencing technologies. PMID:25342680

  8. Trichuris suis and Oesophagostomum dentatum Show Different Sensitivity and Accumulation of Fenbendazole, Albendazole and Levamisole In Vitro

    PubMed Central

    Hansen, Tina V. A.; Nejsum, Peter; Friis, Christian; Olsen, Annette; Thamsborg, Stig Milan

    2014-01-01

    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

  9. Bloodborne pathogens

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000453.htm Bloodborne pathogens To use the sharing features on this page, please enable JavaScript. A pathogen is something that causes disease. Germs that can ...

  10. Characterization of a virulence-associated and cell-wall-located DNase of Streptococcus pyogenes.

    PubMed

    Hasegawa, Tadao; Minami, Masaaki; Okamoto, Akira; Tatsuno, Ichiro; Isaka, Masanori; Ohta, Michio

    2010-01-01

    We investigated culture supernatant proteins from the M1 serotype of Streptococcus pyogenes by two-dimensional gel electrophoresis and peptide mass mapping analysis, and characterized the single protein spots. Among them, we analysed the Spy0747 protein. This protein is homologous to the SsnA protein, a cell-wall-located DNase expressed in Streptococcus suis serotype 2. We designated the Spy0747 protein as SpnA. SpnA protein was also detected in the insoluble fraction of whole-cell lysates using shotgun proteomic analysis, suggesting that SpnA is also located in the cell wall. SpnA was expressed as a glutathione S-transferase-fusion protein in Escherichia coli. We confirmed that the recombinant protein had DNase activity that was dependent on Ca(2+) and Mg(2+), like SsnA. Blood bactericidal assays and mouse infection model experiments showed that the spnA knockout strain was less virulent than the parental strain, thus suggesting that SpnA could play an important role in virulence. Using PCR, we found that the spnA gene was present in all clinical S. pyogenes strains we examined. Our results, together with a previous report identifying Spy0747 as a surface-associated protein, suggest that SpnA is an important cell-wall-located DNase that is generally produced in S. pyogenes and is involved in virulence. PMID:19850619

  11. Whole-genome mapping reveals a large chromosomal inversion on Iberian Brucella suis biovar 2 strains.

    PubMed

    Ferreira, Ana Cristina; Dias, Ricardo; de Sá, Maria Inácia Corrêa; Tenreiro, Rogério

    2016-08-30

    Optical mapping is a technology able to quickly generate high resolution ordered whole-genome restriction maps of bacteria, being a proven approach to search for diversity among bacterial isolates. In this work, optical whole-genome maps were used to compare closely-related Brucella suis biovar 2 strains. This biovar is the unique isolated in domestic pigs and wild boars in Portugal and Spain and most of the strains share specific molecular characteristics establishing an Iberian clonal lineage that can be differentiated from another lineage mainly isolated in several Central European countries. We performed the BamHI whole-genome optical maps of five B. suis biovar 2 field strains, isolated from wild boars in Portugal and Spain (three from the Iberian lineage and two from the Central European one) as well as of the reference strain B. suis biovar 2 ATCC 23445 (Central European lineage, Denmark). Each strain showed a distinct, highly individual configuration of 228-231 BamHI fragments. Nevertheless, a low divergence was globally observed in chromosome II (1.6%) relatively to chromosome I (2.4%). Optical mapping also disclosed genomic events associated with B. suis strains in chromosome I, namely one indel (3.5kb) and one large inversion (944kb). By using targeted-PCR in a set of 176 B. suis strains, including all biovars and haplotypes, the indel was found to be specific of the reference strain ATCC 23445 and the large inversion was shown to be an exclusive genomic marker of the Iberian clonal lineage of biovar 2. PMID:27527786

  12. The influence of dietary carbohydrates on experimental infection with Trichuris suis in pigs.

    PubMed

    Thomsen, L E; Petkevicius, S; Bach Knudsen, K E; Roepstorff, A

    2005-12-01

    Two experiments (Exps 1 and 2) were carried out to study the effect of dietary carbohydrates on the establishment of Trichuris suis in pigs. Two experimental diets based on barley flour were used; Diet 1 was supplemented with non-fermentable carbohydrates from oat hull meal, while Diet 2 was supplemented with fermentable carbohydrates from sugar beet fibre and inulin. In Exp. 1, thirty-two pigs were allocated randomly into 4 groups. Two groups were fed Diet 1 and 2 groups were fed Diet 2. Pigs from one of each diet group were inoculated with 2000 infective T. suis eggs each and the other two groups were uninfected controls. All pigs were slaughtered 8 weeks post-inoculation (p.i.). In Exp. 2, twenty-four pigs were allocated randomly into 2 groups and fed Diet 1 or Diet 2, respectively. All the pigs were inoculated with 2000 infective T. suis eggs. Six pigs from each group were slaughtered 8 weeks p.i. and the remaining 6 pigs from each group were slaughtered 12 weeks p.i. Infections were followed by faecal egg counts and worm burdens were assessed at necropsy. Pigs fed Diet 2 had lower egg counts in both experiments; in Exp. 2 the difference was significant (P<0.05). No differences were found in worm burdens 8 weeks p.i. in both experiments, however, worms from pigs on Diet 2 were significantly shorter (P<0.0001). Pigs fed Diet 2 and slaughtered 12 weeks p.i. had significantly lower worm counts (P<0.01) compared to pigs fed Diet 1. The results indicate that fermentable carbohydrates do not affect the establishment of T. suis in naïve pigs, but result in earlier expulsion and reduced growth of the established worms. Thus, diets with highly fermentable carbohydrates may be used in the control of T. suis. PMID:16336739

  13. Genetic relatedness of Brucella suis biovar 2 isolates from hares, wild boars and domestic pigs.

    PubMed

    Kreizinger, Zsuzsa; Foster, Jeffrey T; Rónai, Zsuzsanna; Sulyok, Kinga M; Wehmann, Enikő; Jánosi, Szilárd; Gyuranecz, Miklós

    2014-08-27

    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. PMID:24962519

  14. Pathogen detection in milk samples by ligation detection reaction-mediated universal array method.

    PubMed

    Cremonesi, P; Pisoni, G; Severgnini, M; Consolandi, C; Moroni, P; Raschetti, M; Castiglioni, B

    2009-07-01

    This paper describes a new DNA chip, based on the use of a ligation detection reaction coupled to a universal array, developed to detect and analyze, directly from milk samples, microbial pathogens known to cause bovine, ovine, and caprine mastitis or to be responsible for foodborne intoxication or infection, or both. Probes were designed for the identification of 15 different bacterial groups: Staphylococcus aureus, Streptococcus agalactiae, nonaureus staphylococci, Streptococcus bovis, Streptococcus equi, Streptococcus canis, Streptococcus dysgalactiae, Streptococcus parauberis, Streptococcus uberis, Streptococcus pyogenes, Mycoplasma spp., Salmonella spp., Bacillus spp., Campylobacter spp., and Escherichia coli and related species. These groups were identified based on the 16S rRNA gene. For microarray validation, 22 strains from the American Type Culture Collection or other culture collections and 50 milk samples were tested. The results demonstrated high specificity, with sensitivity as low as 6 fmol. Moreover, the ligation detection reaction-universal array assay allowed for the identification of Mycoplasma spp. in a few hours, avoiding the long incubation times of traditional microbiological identification methods. The universal array described here is a versatile tool able to identify milk pathogens efficiently and rapidly. PMID:19528580

  15. Localised mitogenic activity in horses following infection with Streptococcus equi.

    PubMed

    McLean, R; Rash, N L; Robinson, C; Waller, A S; Paillot, R

    2015-06-01

    Streptococcus equi subspecies equi (S. equi) is the causative agent of strangles, a highly contagious upper respiratory disease of equids. Streptococcus equi produces superantigens (sAgs), which are thought to contribute to strangles pathogenicity through non-specific T-cell activation and pro-inflammatory response. Streptococcus equi infection induces abscesses in the lymph nodes of the head and neck. In some individuals, some abscess material remains into the guttural pouch and inspissates over time to form chondroids which can harbour live S. equi. The aim of this study was to determine the sites of sAg production during infection and therefore improve our understanding of their role. Abscess material, chondroids and serum collected from Equidae with signs of strangles were tested in mitogenic assays. Mitogenic sAg activity was only detected in abscess material and chondroids. Our data support the localised in vivo activity of sAg during both acute and carrier phases of S. equi infection. PMID:25841794

  16. Recombination-deficient Streptococcus sanguis

    SciTech Connect

    Daneo-Moore, L.; Volpe, A.

    1985-05-01

    A UV-sensitive derivative was obtained from Streptococcus sanguis Challis. The organism could be transformed with a number of small streptococcal plasmids at frequencies equal to, or 1 logarithm below, the transformation frequencies for the parent organism. However, transformation with chromosomal DNA was greatly impaired in the UV-sensitive derivative.

  17. Minimal requirements for growth of Brucella suis and other Brucella species.

    PubMed

    Plommet, M

    1991-10-01

    Minimal nutritional requirements and temperature limits of growth were studied in Brucella suis and, comparatively, in a few other Brucella species. In a saline basic medium including thiosulphate, ammonium sulphate and glucose with addition of 2 or 4 vitamins (nicotinic acid, thiamin and panthotenic acid, biotin), 24 out of 25 B. suis, 4/6 B. melitensis and 1/6 B. abortus strains were able to grow. Some strains, however, needed to be initially induced to grow by other ingredients, CO2, other vitamins, or amino acids, or by a prolonged incubation. In the saline basic medium without ammonium, glutamic acid and/or alanine and arginine, with or without glucose, supported the growth of all the B. suis and B. melitensis strains, except 2 which required a sulphur amino acid. Five out of 6 B. abortus strains did not grow in either medium without addition of one or several aromatic amino acids or, for one strain, aspartic acid, or valine. One strain could also be induced to grow in ammonium medium by other amino acids. In a rich medium with yeast extract, all Brucella species grew at 18 degrees C and 42.5 degrees (except one) while most B. suis (14/17) grew also at 15 degrees C and 44 degrees C, in contrast to other brucellae of which a few strains only grew at these temperatures. In saline ammonium glucose medium, yeast extract at 0.1 g/l provided all the required vitamins and amino acids for all brucellae and at 1 g/l, it even provided enough nitrogen to support growth without ammonium. Such basic saline medium with yeast extract may be advantageously used in routine Brucella culture, instead of the classic undefined peptone mediums. B. suis biovar 1 strains did not differ significantly in their minimal nutritional requirements, precluding the use of these requirements to differentiate the strains, in particular the Chinese vaccine strain S2 from the reference strain 1330 or from other strains from different parts of the world. Finally, B. suis which is endowed with a

  18. Drug resistance profile and serotype of streptococcus of pneumoniae infected pediatric patients.

    PubMed

    Wang, Jiefei; Huang, Nannan; Wang, Guangzhou; Yu, Fengqin

    2016-07-01

    To investigate the surveillance of drug resistance and serotype monitoring of steptococcus pneumoniae in hospitalized children. the pathogenic bacteria isolation and identification methods were employed to do the bacteria isolation identification and drug sensitive test on the specimens from Women & Infants Hospital of Zhengzhou. From the specimens, there were 134 detected strains of Streptococcus pneumoniae, and the drug resistance to erythromycin and clindamycin were respectively 97.7% and 89.9%, and the drug resistance to tetracycline, azithromycin and paediatric compound sulfamethoxazole were respectively 86. 3%, 58. 3%, 51. 2%. The vancomycin resistant Streptococcus pneumoniae were often not found. the Streptococcus pneumoniae in children were generally with drug resistant in Zhengzhou area. It shall strengthen drug resistance surveillance, and reasonably choose antibacterial agents. PMID:27592480

  19. Chromosomal islands of Streptococcus pyogenes and related streptococci: molecular switches for survival and virulence

    PubMed Central

    Nguyen, Scott V.; McShan, William M.

    2014-01-01

    Streptococcus pyogenes is a significant pathogen of humans, annually causing over 700,000,000 infections and 500,000 deaths. Virulence in S. pyogenes is closely linked to mobile genetic elements like phages and chromosomal islands (CI). S. pyogenes phage-like chromosomal islands (SpyCI) confer a complex mutator phenotype on their host. SpyCI integrate into the 5′ end of DNA mismatch repair (MMR) gene mutL, which also disrupts downstream operon genes lmrP, ruvA, and tag. During early logarithmic growth, SpyCI excise from the bacterial chromosome and replicate as episomes, relieving the mutator phenotype. As growth slows and the cells enter stationary phase, SpyCI reintegrate into the chromosome, again silencing the MMR operon. This system creates a unique growth-dependent and reversible mutator phenotype. Additional CI using the identical attachment site in mutL have been identified in related species, including Streptococcus dysgalactiae subsp. equisimilis, Streptococcus anginosus, Streptococcus intermedius, Streptococcus parauberis, and Streptococcus canis. These CI have small genomes, which range from 13 to 20 kB, conserved integrase and DNA replication genes, and no identifiable genes encoding capsid proteins. SpyCI may employ a helper phage for packaging and dissemination in a fashion similar to the Staphylococcus aureus pathogenicity islands (SaPI). Outside of the core replication and integration genes, SpyCI and related CI show considerable diversity with the presence of many indels that may contribute to the host cell phenotype or fitness. SpyCI are a subset of a larger family of streptococcal CI who potentially regulate the expression of other host genes. The biological and phylogenetic analysis of streptococcal chromosomal islands provides important clues as to how these chromosomal islands help S. pyogenes and other streptococcal species persist in human populations in spite of antibiotic therapy and immune challenges. PMID:25161960

  20. Chromosomal islands of Streptococcus pyogenes and related streptococci: molecular switches for survival and virulence.

    PubMed

    Nguyen, Scott V; McShan, William M

    2014-01-01

    Streptococcus pyogenes is a significant pathogen of humans, annually causing over 700,000,000 infections and 500,000 deaths. Virulence in S. pyogenes is closely linked to mobile genetic elements like phages and chromosomal islands (CI). S. pyogenes phage-like chromosomal islands (SpyCI) confer a complex mutator phenotype on their host. SpyCI integrate into the 5' end of DNA mismatch repair (MMR) gene mutL, which also disrupts downstream operon genes lmrP, ruvA, and tag. During early logarithmic growth, SpyCI excise from the bacterial chromosome and replicate as episomes, relieving the mutator phenotype. As growth slows and the cells enter stationary phase, SpyCI reintegrate into the chromosome, again silencing the MMR operon. This system creates a unique growth-dependent and reversible mutator phenotype. Additional CI using the identical attachment site in mutL have been identified in related species, including Streptococcus dysgalactiae subsp. equisimilis, Streptococcus anginosus, Streptococcus intermedius, Streptococcus parauberis, and Streptococcus canis. These CI have small genomes, which range from 13 to 20 kB, conserved integrase and DNA replication genes, and no identifiable genes encoding capsid proteins. SpyCI may employ a helper phage for packaging and dissemination in a fashion similar to the Staphylococcus aureus pathogenicity islands (SaPI). Outside of the core replication and integration genes, SpyCI and related CI show considerable diversity with the presence of many indels that may contribute to the host cell phenotype or fitness. SpyCI are a subset of a larger family of streptococcal CI who potentially regulate the expression of other host genes. The biological and phylogenetic analysis of streptococcal chromosomal islands provides important clues as to how these chromosomal islands help S. pyogenes and other streptococcal species persist in human populations in spite of antibiotic therapy and immune challenges. PMID:25161960

  1. Clinical analysis of cases of neonatal Streptococcus agalactiae sepsis.

    PubMed

    Zeng, S J; Tang, X S; Zhao, W L; Qiu, H X; Wang, H; Feng, Z C

    2016-01-01

    With the advent of antibiotic resistance, pathogenic bacteria have become a major threat in cases of neonatal sepsis; however, guidelines for treatment have not yet been standardized. In this study, 15 cases of neonatal Streptococcus agalactiae sepsis from our hospital were retrospectively analyzed. Of these, nine cases showed early-onset and six cases showed late-onset sepsis. Pathogens were characterized by genotyping and antibiotic sensitivity tests on blood cultures. Results demonstrated that in cases with early-onset sepsis, clinical manifestations affected mainly the respiratory tract, while late-onset sepsis was accompanied by intracranial infection. Therefore, we suggest including a cerebrospinal fluid examination when diagnosing neonatal sepsis. Bacterial genotyping indicated the bacteria were mainly type Ib, Ia, and III S. agalactiae. We recommend treatment with penicillin or ampicillin, since bacteria were resistant to clindamycin and tetracycline. In conclusion, our results provide valuable information for the clinical treatment of S. agalactiae sepsis in neonatal infants. PMID:27323190

  2. Genetic diversity of geographically distinct Streptococcus dysgalactiae isolates from fish

    PubMed Central

    Abdelsalam, M.; Eissa, A.E.; Chen, S.-C.

    2013-01-01

    Streptococcus dysgalactiae is an emerging pathogen of fish. Clinically, infection is characterized by the development of necrotic lesions at the caudal peduncle of infected fishes. The pathogen has been recently isolated from different fish species in many countries. Twenty S. dysgalactiae isolates collected from Japan, Taiwan, Malaysia and Indonesia were molecularly characterized by biased sinusoidal field gel electrophoresis (BSFGE) using SmaI enzyme, and tuf gene sequencing analysis. DNA sequencing of ten S. dysgalactiae revealed no genetic variation in the tuf amplicons, except for three strains. The restriction patterns of chromosomal DNA measured by BSFGE were differentiated into six distinct types and one subtype among collected strains. To our knowledge, this report gives the first snapshot of S. dysgalactiae isolates collected from different countries that are localized geographically and differed on a multinational level. This genetic unrelatedness among different isolates might suggest a high recombination rate and low genetic stability. PMID:25750757

  3. Genetic diversity of geographically distinct Streptococcus dysgalactiae isolates from fish.

    PubMed

    Abdelsalam, M; Eissa, A E; Chen, S-C

    2015-03-01

    Streptococcus dysgalactiae is an emerging pathogen of fish. Clinically, infection is characterized by the development of necrotic lesions at the caudal peduncle of infected fishes. The pathogen has been recently isolated from different fish species in many countries. Twenty S. dysgalactiae isolates collected from Japan, Taiwan, Malaysia and Indonesia were molecularly characterized by biased sinusoidal field gel electrophoresis (BSFGE) using SmaI enzyme, and tuf gene sequencing analysis. DNA sequencing of ten S. dysgalactiae revealed no genetic variation in the tuf amplicons, except for three strains. The restriction patterns of chromosomal DNA measured by BSFGE were differentiated into six distinct types and one subtype among collected strains. To our knowledge, this report gives the first snapshot of S. dysgalactiae isolates collected from different countries that are localized geographically and differed on a multinational level. This genetic unrelatedness among different isolates might suggest a high recombination rate and low genetic stability. PMID:25750757

  4. Cryptosporidium suis infection in post-weaned and adult pigs in Shaanxi province, northwestern China.

    PubMed

    Lin, Qing; Wang, Xing-Ye; Chen, Jian-Wen; Ding, Ling; Zhao, Guang-Hui

    2015-02-01

    Cryptosporidium spp., ubiquitous enteric parasitic protozoa of vertebrates, recently emerged as an important cause of economic loss and zoonosis. The present study aimed to determine the distribution and species of Cryptosporidium in post-weaned and adult pigs in Shaanxi province, northwestern China. A total of 1,337 fresh fecal samples of post-weaned and adult pigs were collected by sterile disposable gloves from 8 areas of Shaanxi province. The samples were examined by Sheather's sugar flotation technique and microscopy at × 400 magnification for Cryptosporidium infection, and the species in positive samples was further identified by PCR amplification of the small subunit (SSU) rRNA gene. A total of 44 fecal samples were successfully amplified by the nested PCR of the partial SSU rRNA, with overall prevalence of 3.3%. The average prevalence of Cryptosporidium infection in each pig farms ranged from 0 to 14.4%. Species identification by sequencing of SSU rRNA gene revealed that 42 (3.1%) samples were Cryptosporidium suis and 2 (0.15%) were Cryptosporidium scrofarum. C. suis had the highest prevalence (7.5%) in growers and the lowest in breeding pigs (0.97%). C. suis was the predominant species in pre-weaned and adult pigs, while C. scrofarum infected pigs older than 3 months only. A season-related difference of C. suis was observed in this study, with the highest prevalence in autumn (5.5%) and the lowest (1.7%) in winter. The present study provided basic information for control of Cryptosporidium infection in pigs and assessment of zoonotic transmission of pigs in Shaanxi province, China. PMID:25748718

  5. Cryptosporidium suis Infection in Post-Weaned and Adult Pigs in Shaanxi Province, Northwestern China

    PubMed Central

    Lin, Qing; Wang, Xing-Ye; Chen, Jian-Wen; Ding, Ling; Zhao, Guang-Hui

    2015-01-01

    Cryptosporidium spp., ubiquitous enteric parasitic protozoa of vertebrates, recently emerged as an important cause of economic loss and zoonosis. The present study aimed to determine the distribution and species of Cryptosporidium in post-weaned and adult pigs in Shaanxi province, northwestern China. A total of 1,337 fresh fecal samples of post-weaned and adult pigs were collected by sterile disposable gloves from 8 areas of Shaanxi province. The samples were examined by Sheather’s sugar flotation technique and microscopy at×400 magnification for Cryptosporidium infection, and the species in positive samples was further identified by PCR amplification of the small subunit (SSU) rRNA gene. A total of 44 fecal samples were successfully amplified by the nested PCR of the partial SSU rRNA, with overall prevalence of 3.3%. The average prevalence of Cryptosporidium infection in each pig farms ranged from 0 to 14.4%. Species identification by sequencing of SSU rRNA gene revealed that 42 (3.1%) samples were Cryptosporidium suis and 2 (0.15%) were Cryptosporidium scrofarum. C. suis had the highest prevalence (7.5%) in growers and the lowest in breeding pigs (0.97%). C. suis was the predominant species in pre-weaned and adult pigs, while C. scrofarum infected pigs older than 3 months only. A season-related difference of C. suis was observed in this study, with the highest prevalence in autumn (5.5%) and the lowest (1.7%) in winter. The present study provided basic information for control of Cryptosporidium infection in pigs and assessment of zoonotic transmission of pigs in Shaanxi province, China. PMID:25748718

  6. Delta-pgm, a new live-attenuated vaccine against Brucella suis.

    PubMed

    Czibener, Cecilia; Del Giudice, Mariela Giselda; Spera, Juan Manuel; Fulgenzi, Fabiana Rosa; Ugalde, Juan Esteban

    2016-03-18

    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. PMID:26899373

  7. Seroepidemiologic survey for Chlamydia suis in wild boar (Sus scrofa) populations in Italy.

    PubMed

    Di Francesco, Antonietta; Donati, Manuela; Morandi, Federico; Renzi, Maria; Masia, Marco Antonio; Ostanello, Fabio; Salvatore, Daniela; Cevenini, Roberto; Baldelli, Raffaella

    2011-07-01

    We used serology to estimate the prevalence of exposure to chlamydiae in Italian populations of wild boars (Sus scrofa). Sera from 173 hunter-killed wild boars harvested during the 2006-2009 hunting seasons in three Italian regions were tested for antibodies to Chlamydia suis, Chlamydophila pecorum, Chlamydophila abortus, and Chlamydophila psittaci by the microimmunofluorescence test. Antibody titers to chlamydiae ≥ 1:32 were detected in 110 of the 173 samples tested (63.6%). Specific reactivity could be assessed only in 44 sera with antibody titers to C. suis that were two- to threefold higher than antibody titers against the other chlamydial species; the other 66 sera had similar reactivity against all the chlamydia species tested. Antibody to C. suis was detected in sera from wild boar populations with rare or no known contact with domestic pigs. These results suggest that the wild boar could be a chlamydia reservoir and may acquire chlamydiae independent of contacts with the domestic pig. PMID:21719838

  8. Changes in lymphocyte populations in suckling piglets during primary infections with Isospora suis.

    PubMed

    Worliczek, H L; Buggelsheim, M; Alexandrowicz, R; Witter, K; Schmidt, P; Gerner, W; Saalmüller, A; Joachim, A

    2010-04-01

    Isospora suis, a common intestinal parasite of piglets, causes neonatal porcine coccidiosis, which results in reduced and uneven weaning weights and economic losses in pig production. Nevertheless, there are no detailed studies available on the immune response to I. suis. The aim of this study was to carry out phenotypical characterization of lymphocytes during primary infections on day 3 after birth. Infected and noninfected piglets were investigated between days 7 and 16 after birth. Lymphocytes from the blood, spleen and mesenteric lymph nodes (flow cytometry) and of the jejunal mucosa (immunohistochemistry) were analysed. A decrease in T cells, especially with the phenotype of resting T-helper cells, T-cell receptor-gammadelta-T cells, and regulatory T cells in the blood, spleen and mesenteric lymph nodes was noticeable. An increase in cells with the phenotype of natural killer cells in the spleen of infected animals was found, and the subset of TcR-gammadelta-T cells was strongly increased in the gut mucosa. Our findings suggest an accelerated migration of those cells into the gut. This study provides a strong indication for the involvement of adaptive and innate immune response mechanisms in the primary immune response to I. suis, especially of TcR-gammadelta-T cells as a linkage between innate and adaptive immunity. PMID:20398223

  9. Profiling circulating miRNAs in serum from pigs infected with the porcine whipworm, Trichuris suis.

    PubMed

    Hansen, Eline Palm; Kringel, Helene; Thamsborg, Stig Milan; Jex, Aaron; Nejsum, Peter

    2016-06-15

    microRNAs (miRNAs) are recently discovered as key regulators of gene translation and are becoming increasingly recognized for their involvement in various diseases. This study investigates the miRNA profile in pig serum during the course of an infection with the gastrointestinal parasite, Trichuris suis. Of this panel, the expression of selected miRNAs in serum from T. suis infected and uninfected pigs were determined by quantitative real time PCR using Exiqon Human Panel assays at 0, 2, 4, 6, 8 and 10 weeks post first infection (wpi). One miRNA, ssc-let-7d-3p, was significantly up-regulated in infected pigs 8 wpi. Interestingly, ssc-let-7d-3p shows high complementary to tsu-let-7a, which is the most highly transcribed miRNA in T. suis. The let-7 family miRNAs have been shown to post-transcriptionally regulate the translation of the helminth-controlling cytokine, IL-13, in a murine model for asthma and we hypothesize possible interactions between these host- and parasite-derived miRNAs and their immunomodulating roles. PMID:27198773

  10. The role of coagulation/fibrinolysis during Streptococcus pyogenes infection

    PubMed Central

    Loof, Torsten G.; Deicke, Christin; Medina, Eva

    2014-01-01

    The hemostatic system comprises platelet aggregation, coagulation and fibrinolysis and is a host defense mechanism that protects the integrity of the vascular system after tissue injury. During bacterial infections, the coagulation system cooperates with the inflammatory system to eliminate the invading pathogens. However, pathogenic bacteria have frequently evolved mechanisms to exploit the hemostatic system components for their own benefit. Streptococcus pyogenes, also known as Group A Streptococcus, provides a remarkable example of the extraordinary capacity of pathogens to exploit the host hemostatic system to support microbial survival and dissemination. The coagulation cascade comprises the contact system (also known as the intrinsic pathway) and the tissue factor pathway (also known as the extrinsic pathway), both leading to fibrin formation. During the early phase of S. pyogenes infection, the activation of the contact system eventually leads to bacterial entrapment within a fibrin clot, where S. pyogenes is immobilized and killed. However, entrapped S. pyogenes can circumvent the antimicrobial effect of the clot by sequestering host plasminogen on the bacterial cell surface that, after conversion into its active proteolytic form, plasmin, degrades the fibrin network and facilitates the liberation of S. pyogenes from the clot. Furthermore, the surface-localized fibrinolytic activity also cleaves a variety of extracellular matrix proteins, thereby enabling S. pyogenes to migrate across barriers and disseminate within the host. This review summarizes the knowledge gained during the last two decades on the role of coagulation/fibrinolysis in host defense against S. pyogenes as well as the strategies developed by this pathogen to evade and exploit these host mechanisms for its own benefit. PMID:25309880

  11. Quorum sensing in group A Streptococcus

    PubMed Central

    Jimenez, Juan Cristobal; Federle, Michael J.

    2014-01-01

    Quorum sensing (QS) is a widespread phenomenon in the microbial world that has important implications in the coordination of population-wide responses in several bacterial pathogens. In Group A Streptococcus (GAS), many questions surrounding QS systems remain to be solved pertaining to their function and their contribution to the GAS lifestyle in the host. The QS systems of GAS described to date can be categorized into four groups: regulator gene of glucosyltransferase (Rgg), Sil, lantibiotic systems, and LuxS/AI-2. The Rgg family of proteins, a conserved group of transcription factors that modify their activity in response to signaling peptides, has been shown to regulate genes involved in virulence, biofilm formation and competence. The sil locus, whose expression is regulated by the activity of signaling peptides and a putative two-component system (TCS), has been implicated on regulating genes involved with invasive disease in GAS isolates. Lantibiotic regulatory systems are involved in the production of bacteriocins and their autoregulation, and some of these genes have been shown to target both bacterial organisms as well as processes of survival inside the infected host. Finally AI-2 (dihydroxy pentanedione, DPD), synthesized by the LuxS enzyme in several bacteria including GAS, has been proposed to be a universal bacterial communication molecule. In this review we discuss the mechanisms of these four systems, the putative functions of their targets, and pose critical questions for future studies. PMID:25309879

  12. Parallel Evolution in Streptococcus pneumoniae Biofilms

    PubMed Central

    Churton, Nicholas W. V.; Misra, Raju V.; Howlin, Robert P.; Allan, Raymond N.; Jefferies, Johanna; Faust, Saul N.; Gharbia, Saheer E.; Edwards, Richard J.; Clarke, Stuart C.; Webb, Jeremy S.

    2016-01-01

    Streptococcus pneumoniae is a commensal human pathogen and the causative agent of various invasive and noninvasive diseases. Carriage of the pneumococcus in the nasopharynx is thought to be mediated by biofilm formation, an environment where isogenic populations frequently give rise to morphological colony variants, including small colony variant (SCV) phenotypes. We employed metabolic characterization and whole-genome sequencing of biofilm-derived S. pneumoniae serotype 22F pneumococcal SCVs to investigate diversification during biofilm formation. Phenotypic profiling revealed that SCVs exhibit reduced growth rates, reduced capsule expression, altered metabolic profiles, and increased biofilm formation compared to the ancestral strain. Whole-genome sequencing of 12 SCVs from independent biofilm experiments revealed that all SCVs studied had mutations within the DNA-directed RNA polymerase delta subunit (RpoE). Mutations included four large-scale deletions ranging from 51 to 264 bp, one insertion resulting in a coding frameshift, and seven nonsense single-nucleotide substitutions that result in a truncated gene product. This work links mutations in the rpoE gene to SCV formation and enhanced biofilm development in S. pneumoniae and therefore may have important implications for colonization, carriage, and persistence of the organism. Furthermore, recurrent mutation of the pneumococcal rpoE gene presents an unprecedented level of parallel evolution in pneumococcal biofilm development. PMID:27190203

  13. Parallel Evolution in Streptococcus pneumoniae Biofilms.

    PubMed

    Churton, Nicholas W V; Misra, Raju V; Howlin, Robert P; Allan, Raymond N; Jefferies, Johanna; Faust, Saul N; Gharbia, Saheer E; Edwards, Richard J; Clarke, Stuart C; Webb, Jeremy S

    2016-01-01

    Streptococcus pneumoniae is a commensal human pathogen and the causative agent of various invasive and noninvasive diseases. Carriage of the pneumococcus in the nasopharynx is thought to be mediated by biofilm formation, an environment where isogenic populations frequently give rise to morphological colony variants, including small colony variant (SCV) phenotypes. We employed metabolic characterization and whole-genome sequencing of biofilm-derived S. pneumoniae serotype 22F pneumococcal SCVs to investigate diversification during biofilm formation. Phenotypic profiling revealed that SCVs exhibit reduced growth rates, reduced capsule expression, altered metabolic profiles, and increased biofilm formation compared to the ancestral strain. Whole-genome sequencing of 12 SCVs from independent biofilm experiments revealed that all SCVs studied had mutations within the DNA-directed RNA polymerase delta subunit (RpoE). Mutations included four large-scale deletions ranging from 51 to 264 bp, one insertion resulting in a coding frameshift, and seven nonsense single-nucleotide substitutions that result in a truncated gene product. This work links mutations in the rpoE gene to SCV formation and enhanced biofilm development in S. pneumoniae and therefore may have important implications for colonization, carriage, and persistence of the organism. Furthermore, recurrent mutation of the pneumococcal rpoE gene presents an unprecedented level of parallel evolution in pneumococcal biofilm development. PMID:27190203

  14. Immune ageing and susceptibility to Streptococcus pneumoniae.

    PubMed

    Gonçalves, Mariana Torrente; Mitchell, Timothy J; Lord, Janet M

    2016-06-01

    Streptococcus pneumoniae is a complex Gram-positive bacterium comprising over 90 different serotypes and is a major cause of pneumonia. Susceptibility to S. pneumoniae is remarkably age-related being greatest in children under 5 years old and adults over 65. Whilst the immaturity of the immune system is largely responsible for poor immunity in the former, the underlying causes of susceptibility in older adults is complex. Immunity to S. pneumoniae is mediated predominantly through the inflammatory response in the nasopharyngeal mucosa recruiting phagocytes (neutrophils and monocyte/macrophages) which recognise the pathogen via TLR2 and ingest and kill the bacteria, with the induction of Th17 cells being required to maintain neutrophil recruitment and ensure clearance of the infection. In this review we discuss the impact of ageing upon these aspects of immunity to S. pneumoniae, as well as age-related changes to the serotypes present in the adult nasopharyngeal tract which could further influence susceptibility to infection. PMID:26472172

  15. An unusual case of Streptococcus anginosus group pyomyositis diagnosed using direct 16S ribosomal DNA sequencing

    PubMed Central

    Walkty, Andrew; Embil, John M; Nichol, Kim; Karlowsky, James

    2014-01-01

    Bacteria belonging to the Streptococcus anginosus group (Streptococcus intermedius, Streptococcus constellatus and Streptococcus anginosus) are capable of causing serious pyogenic infections, with a tendency for abscess formation. The present article reports a case of S anginosus group pyomyositis in a 47-year-old man. The pathogen was recovered from one of two blood cultures obtained from the patient, but speciation was initially not performed because the organism was considered to be a contaminant (viridans streptococci group). The diagnosis was ultimately confirmed using 16S ribosomal DNA sequencing of purulent fluid obtained from a muscle abscess aspirate. The present case serves to emphasize that finding even a single positive blood culture of an organism belonging to the S anginosus group should prompt careful evaluation of the patient for a pyogenic focus of infection. It also highlights the potential utility of 16S ribosomal DNA amplification and sequencing in direct pathogen detection from aspirated fluid in cases of pyomyositis in which antimicrobial therapy was initiated before specimen collection. PMID:24634686

  16. Immunoproteomic analysis of the antibody response obtained in Nile tilapia following vaccination with a Streptococcus iniae vaccine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus iniae is one of the most economically important Gram-positive pathogens in cultured fish species worldwide. The USDA-ARS Aquatic Animal Health Research Unit developed a modified (contains concentrated culture supernatant) S. iniae bacterin that has been demonstrated to be efficacious,...

  17. Protection against heterologous Streptococcus iniae isolates using a modified bacterin vaccine in Nile tilapia, Oreochromis niloticus (L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus iniae is a significant pathogen impacting aquaculture production worldwide. The objectives of this study were to determine if a developed modified S. iniae (ARS-98-60) bacterin vaccine is efficacious in Nile tilapia (Oreochromis niloticus L.) against challenge with heterologous isolat...

  18. Genome Sequence of Streptococcus phocae subsp. phocae Strain ATCC 51973T Isolated from a Harbor Seal (Phoca vitulina)

    PubMed Central

    Poblete-Morales, Matías

    2015-01-01

    Streptococcus phocae subsp. phocae is a pathogen that affects different pinniped and mammalian species. This announcement reports the genome sequence of the type strain ATCC 51973 isolated in Norway from clinical specimens of harbor seal (Phoca vitulina), revealing interesting genes related to possible virulence factors. PMID:26586875

  19. Rapid Detection and Identification of Streptococcus Iniae Using a Monoclonal Antibody-Based Indirect Fluorescent Antibody Technique

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus iniae is among the major pathogens of a large number of fish species cultured in fresh and marine recirculating and net pen production systems . The traditional plate culture technique to detect and identify S. iniae is time consuming and may be problematic due to phenotypic variations...

  20. Inhibition of Streptococcus mutans biofilm formation by Streptococcus salivarius FruA.

    PubMed

    Ogawa, Ayako; Furukawa, Soichi; Fujita, Shuhei; Mitobe, Jiro; Kawarai, Taketo; Narisawa, Naoki; Sekizuka, Tsuyoshi; Kuroda, Makoto; Ochiai, Kuniyasu; Ogihara, Hirokazu; Kosono, Saori; Yoneda, Saori; Watanabe, Haruo; Morinaga, Yasushi; Uematsu, Hiroshi; Senpuku, Hidenobu

    2011-03-01

    The oral microbial flora consists of many beneficial species of bacteria that are associated with a healthy condition and control the progression of oral disease. Cooperative interactions between oral streptococci and the pathogens play important roles in the development of dental biofilms in the oral cavity. To determine the roles of oral streptococci in multispecies biofilm development and the effects of the streptococci in biofilm formation, the active substances inhibiting Streptococcus mutans biofilm formation were purified from Streptococcus salivarius ATCC 9759 and HT9R culture supernatants using ion exchange and gel filtration chromatography. Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry analysis was performed, and the results were compared to databases. The S. salivarius HT9R genome sequence was determined and used to indentify candidate proteins for inhibition. The candidates inhibiting biofilms were identified as S. salivarius fructosyltransferase (FTF) and exo-beta-d-fructosidase (FruA). The activity of the inhibitors was elevated in the presence of sucrose, and the inhibitory effects were dependent on the sucrose concentration in the biofilm formation assay medium. Purified and commercial FruA from Aspergillus niger (31.6% identity and 59.6% similarity to the amino acid sequence of FruA from S. salivarius HT9R) completely inhibited S. mutans GS-5 biofilm formation on saliva-coated polystyrene and hydroxyapatite surfaces. Inhibition was induced by decreasing polysaccharide production, which is dependent on sucrose digestion rather than fructan digestion. The data indicate that S. salivarius produces large quantities of FruA and that FruA alone may play an important role in multispecies microbial interactions for sucrose-dependent biofilm formation in the oral cavity. PMID:21239559

  1. Inhibition of Streptococcus mutans Biofilm Formation by Streptococcus salivarius FruA▿

    PubMed Central

    Ogawa, Ayako; Furukawa, Soichi; Fujita, Shuhei; Mitobe, Jiro; Kawarai, Taketo; Narisawa, Naoki; Sekizuka, Tsuyoshi; Kuroda, Makoto; Ochiai, Kuniyasu; Ogihara, Hirokazu; Kosono, Saori; Yoneda, Saori; Watanabe, Haruo; Morinaga, Yasushi; Uematsu, Hiroshi; Senpuku, Hidenobu

    2011-01-01

    The oral microbial flora consists of many beneficial species of bacteria that are associated with a healthy condition and control the progression of oral disease. Cooperative interactions between oral streptococci and the pathogens play important roles in the development of dental biofilms in the oral cavity. To determine the roles of oral streptococci in multispecies biofilm development and the effects of the streptococci in biofilm formation, the active substances inhibiting Streptococcus mutans biofilm formation were purified from Streptococcus salivarius ATCC 9759 and HT9R culture supernatants using ion exchange and gel filtration chromatography. Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry analysis was performed, and the results were compared to databases. The S. salivarius HT9R genome sequence was determined and used to indentify candidate proteins for inhibition. The candidates inhibiting biofilms were identified as S. salivarius fructosyltransferase (FTF) and exo-beta-d-fructosidase (FruA). The activity of the inhibitors was elevated in the presence of sucrose, and the inhibitory effects were dependent on the sucrose concentration in the biofilm formation assay medium. Purified and commercial FruA from Aspergillus niger (31.6% identity and 59.6% similarity to the amino acid sequence of FruA from S. salivarius HT9R) completely inhibited S. mutans GS-5 biofilm formation on saliva-coated polystyrene and hydroxyapatite surfaces. Inhibition was induced by decreasing polysaccharide production, which is dependent on sucrose digestion rather than fructan digestion. The data indicate that S. salivarius produces large quantities of FruA and that FruA alone may play an important role in multispecies microbial interactions for sucrose-dependent biofilm formation in the oral cavity. PMID:21239559

  2. Zinc disrupts central carbon metabolism and capsule biosynthesis in Streptococcus pyogenes

    PubMed Central

    Ong, Cheryl-lynn Y.; Walker, Mark J.; McEwan, Alastair G.

    2015-01-01

    Neutrophils release free zinc to eliminate the phagocytosed bacterial pathogen Streptococcus pyogenes (Group A Streptococcus; GAS). In this study, we investigated the mechanisms underpinning zinc toxicity towards this human pathogen, responsible for diseases ranging from pharyngitis and impetigo, to severe invasive infections. Using the globally-disseminated M1T1 GAS strain, we demonstrate that zinc stress impairs glucose metabolism through the inhibition of the glycolytic enzymes phosphofructokinase and glyceraldehyde-3-phosphate dehydrogenase. In the presence of zinc, a metabolic shift to the tagatose-6-phosphate pathway allows conversion of D-galactose to dihydroxyacetone phosphate and glyceraldehyde phosphate, partially bypassing impaired glycolytic enzymes to generate pyruvate. Additionally, zinc inhibition of phosphoglucomutase results in decreased capsule biosynthesis. These data indicate that zinc exerts it toxicity via mechanisms that inhibit both GAS central carbon metabolism and virulence pathways. PMID:26028191

  3. Zinc disrupts central carbon metabolism and capsule biosynthesis in Streptococcus pyogenes.

    PubMed

    Ong, Cheryl-lynn Y; Walker, Mark J; McEwan, Alastair G

    2015-01-01

    Neutrophils release free zinc to eliminate the phagocytosed bacterial pathogen Streptococcus pyogenes (Group A Streptococcus; GAS). In this study, we investigated the mechanisms underpinning zinc toxicity towards this human pathogen, responsible for diseases ranging from pharyngitis and impetigo, to severe invasive infections. Using the globally-disseminated M1T1 GAS strain, we demonstrate that zinc stress impairs glucose metabolism through the inhibition of the glycolytic enzymes phosphofructokinase and glyceraldehyde-3-phosphate dehydrogenase. In the presence of zinc, a metabolic shift to the tagatose-6-phosphate pathway allows conversion of D-galactose to dihydroxyacetone phosphate and glyceraldehyde phosphate, partially bypassing impaired glycolytic enzymes to generate pyruvate. Additionally, zinc inhibition of phosphoglucomutase results in decreased capsule biosynthesis. These data indicate that zinc exerts it toxicity via mechanisms that inhibit both GAS central carbon metabolism and virulence pathways. PMID:26028191

  4. Streptococcus tangierensis sp. nov. and Streptococcus cameli sp. nov., two novel Streptococcus species isolated from raw camel milk in Morocco.

    PubMed

    Kadri, Zaina; Vandamme, Peter; Ouadghiri, Mouna; Cnockaert, Margo; Aerts, Maarten; Elfahime, El Mostafa; Farricha, Omar El; Swings, Jean; Amar, Mohamed

    2015-02-01

    Biochemical and molecular genetic studies were performed on two unidentified Gram-stain positive, catalase and oxidase negative, non-hemolytic Streptococcus-like organisms recovered from raw camel milk in Morocco. Phenotypic characterization and comparative 16S rRNA gene sequencing demonstrated that the two strains were highly different from each other and that they did not correspond to any recognized species of the genus Streptococcus. Phylogenetic analysis based on 16S rRNA gene sequences showed the unidentified organisms each formed a hitherto unknown sub-line within the genus Streptococcus, displaying a close affinity with Streptococcus moroccensis, Streptococcus minor and Streptococcus ovis. DNA G+C content determination, MALDI-TOF mass spectrometry and biochemical tests demonstrated the bacterial isolates represent two novel species. Based on the phenotypic distinctiveness of the new bacteria and molecular genetic evidence, it is proposed to classify the two strains as Streptococcus tangierensis sp. nov., with CCMM B832(T) (=LMG 27683(T)) as the type strain, and Streptococcus cameli sp. nov., with CCMM B834(T) (=LMG 27685(T)) as the type strain. PMID:25491120

  5. Adapting a diet from sugar to meat: double-dealing genes of Streptococcus pyogenes.

    PubMed

    Rosch, Jason W; Tuomanen, Elaine

    2007-04-01

    Intuitively, paralogues created by gene duplication should retain related functions. However, a study of the two lactose metabolic operons of Streptococcus pyogenes, reported in this issue of Molecular Microbiology, indicates that paralogues might evolve very different functions, in this case changing from a metabolic enzyme to a regulator of virulence. Divergence of paralogues could be a newly recognized theme in the metamorphosis of a bacteria from innocuous to pathogenic. PMID:17493119

  6. [Destructive endocarditis caused by Streptococcus sanguis on normal valves after gastroduodenoscopy].

    PubMed

    Pentimone, F; Del Corso, L; Borelli, A; Riccioni, S; Salvatore, L

    1991-06-01

    In recent years, epidemiological and clinical patterns in infective endocarditis are changed: mean age of patients, sex, underlying cardiac diseases, source of bacteremia, availability of better diagnostic methods--specially two-dimensional and doppler echocardiography--and surgical options. The Authors report a paradigmatic case of a young man without cardiac disease, who developed a destructive endocarditis complicated by refractory congestive heart failure; the cause was an organism of low pathogenicity, Streptococcus sanguis, that entered the bloodstream after gastroduodenoscopy. PMID:1961444

  7. Draft Genome Sequences of Four Genetically Distinct Human Isolates of Streptococcus dysgalactiae subsp. equisimilis

    PubMed Central

    Evers, Caitlin; Patel, Khushali; Petrosyan, Varduhi; Morrison, Clay; Varghese, Viju; Chu, Randy A.; Baig, Aymen; Thompson, Erika J.; Chase, Michael; Hu, Peter C.

    2015-01-01

    β-Hemolytic group C and group G streptococci (GCS-GGS; Streptococcus dysgalactiae subsp. equisimilis) emerged as human pathogens in the late 1970s. We report here the draft genome sequences of four genetically distinct human strains of GCS-GGS isolated between the 1960s and 1980s. Comparative analysis of these genomes may provide a deeper understanding of GCS-GGS genome and virulence evolution. PMID:26430051

  8. Streptococcus salivarius K12 Limits Group B Streptococcus Vaginal Colonization

    PubMed Central

    Patras, Kathryn A.; Wescombe, Philip A.; Rösler, Berenice; Hale, John D.; Tagg, John R.

    2015-01-01

    Streptococcus agalactiae (group B streptococcus [GBS]) colonizes the rectovaginal tract in 20% to 30% of women and during pregnancy can be transmitted to the newborn, causing severe invasive disease. Current routine screening and antibiotic prophylaxis have fallen short of complete prevention of GBS transmission, and GBS remains a leading cause of neonatal infection. We have investigated the ability of Streptococcus salivarius, a predominant member of the native human oral microbiota, to control GBS colonization. Comparison of the antibacterial activities of multiple S. salivarius strains by use of a deferred-antagonism test showed that S. salivarius strain K12 exhibited the broadest spectrum of activity against GBS. K12 effectively inhibited all GBS strains tested, including disease-implicated isolates from newborns and colonizing isolates from the vaginal tract of pregnant women. Inhibition was dependent on the presence of megaplasmid pSsal-K12, which encodes the bacteriocins salivaricin A and salivaricin B; however, in coculture experiments, GBS growth was impeded by K12 independently of the megaplasmid. We also demonstrated that K12 adheres to and invades human vaginal epithelial cells at levels comparable to GBS. Inhibitory activity of K12 was examined in vivo using a mouse model of GBS vaginal colonization. Mice colonized with GBS were treated vaginally with K12. K12 administration significantly reduced GBS vaginal colonization in comparison to nontreated controls, and this effect was partially dependent on the K12 megaplasmid. Our results suggest that K12 may have potential as a preventative therapy to control GBS vaginal colonization and thereby prevent its transmission to the neonate during pregnancy. PMID:26077762

  9. Streptococcus salivarius K12 Limits Group B Streptococcus Vaginal Colonization.

    PubMed

    Patras, Kathryn A; Wescombe, Philip A; Rösler, Berenice; Hale, John D; Tagg, John R; Doran, Kelly S

    2015-09-01

    Streptococcus agalactiae (group B streptococcus [GBS]) colonizes the rectovaginal tract in 20% to 30% of women and during pregnancy can be transmitted to the newborn, causing severe invasive disease. Current routine screening and antibiotic prophylaxis have fallen short of complete prevention of GBS transmission, and GBS remains a leading cause of neonatal infection. We have investigated the ability of Streptococcus salivarius, a predominant member of the native human oral microbiota, to control GBS colonization. Comparison of the antibacterial activities of multiple S. salivarius strains by use of a deferred-antagonism test showed that S. salivarius strain K12 exhibited the broadest spectrum of activity against GBS. K12 effectively inhibited all GBS strains tested, including disease-implicated isolates from newborns and colonizing isolates from the vaginal tract of pregnant women. Inhibition was dependent on the presence of megaplasmid pSsal-K12, which encodes the bacteriocins salivaricin A and salivaricin B; however, in coculture experiments, GBS growth was impeded by K12 independently of the megaplasmid. We also demonstrated that K12 adheres to and invades human vaginal epithelial cells at levels comparable to GBS. Inhibitory activity of K12 was examined in vivo using a mouse model of GBS vaginal colonization. Mice colonized with GBS were treated vaginally with K12. K12 administration significantly reduced GBS vaginal colonization in comparison to nontreated controls, and this effect was partially dependent on the K12 megaplasmid. Our results suggest that K12 may have potential as a preventative therapy to control GBS vaginal colonization and thereby prevent its transmission to the neonate during pregnancy. PMID:26077762

  10. Group A Streptococcus Endometritis following Medical Abortion

    PubMed Central

    Gendron, Nicolas; Joubrel, Caroline; Nedellec, Sophie; Campagna, Jennifer; Agostini, Aubert; Doucet-Populaire, Florence; Casetta, Anne; Raymond, Josette; Kernéis, Solen

    2014-01-01

    Medical abortion is not recognized as a high-risk factor for invasive pelvic infection. Here, we report two cases of group A Streptococcus (GAS; Streptococcus pyogenes) endometritis following medical abortions with a protocol of oral mifepristone and misoprostol. PMID:24829245

  11. Comparison of transmission dynamics between Streptococcus uberis and Streptococcus agalactiae intramammary infections.

    PubMed

    Leelahapongsathon, Kansuda; Schukken, Ynte Hein; Pinyopummintr, Tanu; Suriyasathaporn, Witaya

    2016-02-01

    The objectives of study were to determine the transmission parameters (β), durations of infection, and basic reproductive numbers (R0) of both Streptococcus agalactiae and Streptococcus uberis as pathogens causing mastitis outbreaks in dairy herds. A 10-mo longitudinal study was performed using 2 smallholder dairy herds with mastitis outbreaks caused by Strep. agalactiae and Strep. uberis, respectively. Both herds had poor mastitis control management and did not change their milking management during the entire study period. Quarter milk samples were collected at monthly intervals from all lactating animals in each herd for bacteriological identification. The durations of infection for Strep. uberis intramammary infection (IMI) and Strep. agalactiae IMI were examined using Kaplan-Meier survival curves, and the Kaplan-Meier survival functions for Strep. uberis IMI and Strep. agalactiae IMI were compared using log rank survival-test. The spread of Strep. uberis and Strep. agalactiae through the population was determined by transmission parameter, β, the probability per unit of time that one infectious quarter will infect another quarter, assuming that all other quarters are susceptible. For the Strep. uberis outbreak herd (31 cows), 56 new infections and 28 quarters with spontaneous cure were observed. For the Strep. agalactiae outbreak herd (19 cows), 26 new infections and 9 quarters with spontaneous cure were observed. The duration of infection for Strep. agalactiae (mean=270.84 d) was significantly longer than the duration of infection for Strep. uberis (mean=187.88 d). The transmission parameters (β) estimated (including 95% confidence interval) for Strep. uberis IMI and Strep. agalactiae IMI were 0.0155 (0.0035-0.0693) and 0.0068 (0.0008-0.0606), respectively. The R0 (including 95% confidence interval) during the study were 2.91 (0.63-13.47) and 1.86 (0.21-16.61) for Strep. uberis IMI and Strep. agalactiae IMI, respectively. In conclusion, the transmission

  12. Toxin-Antitoxin Systems in Clinical Pathogens.

    PubMed

    Fernández-García, Laura; Blasco, Lucia; Lopez, Maria; Bou, German; García-Contreras, Rodolfo; Wood, Thomas; Tomas, María

    2016-01-01

    Toxin-antitoxin (TA) systems are prevalent in bacteria and archaea. Although not essential for normal cell growth, TA systems are implicated in multiple cellular functions associated with survival under stress conditions. Clinical strains of bacteria are currently causing major human health problems as a result of their multidrug resistance, persistence and strong pathogenicity. Here, we present a review of the TA systems described to date and their biological role in human pathogens belonging to the ESKAPE group (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter spp.) and others of clinical relevance (Escherichia coli, Burkholderia spp., Streptococcus spp. and Mycobacterium tuberculosis). Better understanding of the mechanisms of action of TA systems will enable the development of new lines of treatment for infections caused by the above-mentioned pathogens. PMID:27447671

  13. Toxin-Antitoxin Systems in Clinical Pathogens

    PubMed Central

    Fernández-García, Laura; Blasco, Lucia; Lopez, Maria; Bou, German; García-Contreras, Rodolfo; Wood, Thomas; Tomas, María

    2016-01-01

    Toxin-antitoxin (TA) systems are prevalent in bacteria and archaea. Although not essential for normal cell growth, TA systems are implicated in multiple cellular functions associated with survival under stress conditions. Clinical strains of bacteria are currently causing major human health problems as a result of their multidrug resistance, persistence and strong pathogenicity. Here, we present a review of the TA systems described to date and their biological role in human pathogens belonging to the ESKAPE group (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter spp.) and others of clinical relevance (Escherichia coli, Burkholderia spp., Streptococcus spp. and Mycobacterium tuberculosis). Better understanding of the mechanisms of action of TA systems will enable the development of new lines of treatment for infections caused by the above-mentioned pathogens. PMID:27447671

  14. Pathogen intelligence

    PubMed Central

    Steinert, Michael

    2014-01-01

    Different species inhabit different sensory worlds and thus have evolved diverse means of processing information, learning and memory. In the escalated arms race with host defense, each pathogenic bacterium not only has evolved its individual cellular sensing and behavior, but also collective sensing, interbacterial communication, distributed information processing, joint decision making, dissociative behavior, and the phenotypic and genotypic heterogeneity necessary for epidemiologic success. Moreover, pathogenic populations take advantage of dormancy strategies and rapid evolutionary speed, which allow them to save co-generated intelligent traits in a collective genomic memory. This review discusses how these mechanisms add further levels of complexity to bacterial pathogenicity and transmission, and how mining for these mechanisms could help to develop new anti-infective strategies. PMID:24551600

  15. Alterations in the Porcine Colon Microbiota Induced by the Gastrointestinal Nematode Trichuris suis

    PubMed Central

    Wu, Sitao; Li, Weizhong; Navarro, Karl; Couch, Robin D.; Hill, Dolores; Urban, Joseph F.

    2012-01-01

    Helminth parasites ensure their survival by regulating host immunity through mechanisms that dampen inflammation. These properties have recently been exploited therapeutically to treat human diseases. The biocomplexity of the intestinal lumen suggests that interactions between the parasite and the intestinal microbiota would also influence inflammation. In this study, we characterized the microbiota in the porcine proximal colon in response to Trichuris suis (whipworm) infection using 16S rRNA gene-based and whole-genome shotgun (WGS) sequencing. A 21-day T. suis infection in four pigs induced a significant change in the composition of the proximal colon microbiota compared to that of three parasite-naive pigs. Among the 15 phyla identified, the abundances of Proteobacteria and Deferribacteres were changed in infected pigs. The abundances of approximately 13% of genera were significantly altered by infection. Changes in relative abundances of Succinivibrio and Mucispirillum, for example, may relate to alterations in carbohydrate metabolism and niche disruptions in mucosal interfaces induced by parasitic infection, respectively. Of note, infection by T. suis led to a significant shift in the metabolic potential of the proximal colon microbiota, where 26% of all metabolic pathways identified were affected. Besides carbohydrate metabolism, lysine biosynthesis was repressed as well. A metabolomic analysis of volatile organic compounds (VOCs) in the luminal contents showed a relative absence in infected pigs of cofactors for carbohydrate and lysine biosynthesis, as well as an accumulation of oleic acid, suggesting altered fatty acid absorption contributing to local inflammation. Our findings should facilitate development of strategies for parasitic control in pigs and humans. PMID:22493085

  16. Endocarditis caused by unusual Streptococcus species (Streptococcus pluranimalium)

    PubMed Central

    Fotoglidis, A; Pagourelias, E; Kyriakou, P; Vassilikos, V

    2015-01-01

    Background Infective endocarditis in intravenous drug abusers is caused mainly by Staphylococcus species and usually affects the right heart valves. Case Description We report the case of a 37-years-old intravenous drug abuser, who was diagnosed with infective endocarditis of the mitral and aortic valve. An unusual Streptococcus species (Streptococcus pluranimalium) was isolated from surgical specimens (peripheral arterial emboli, valves’ vegetations) which, according to the literature, is related to animals’ diseases such as infective endocarditis in adult broiler parents, with no references existing regarding causing such disease in humans. This unusual coccus infection caused specific clinical features (sizable vegetation on mitral valve >2cm, smaller vegetations on aortic valve, systemic emboli), resistance to antimicrobial therapy, rapid progression of the disease (despite of medical therapy and surgical replacement of both valves), and finally the death of the patient two months after the initial presentation of infective endocarditis. Conclusion Unusual cases of infective endocarditis in intravenous drug abusers are emerging and are characterized by changing microbiological profile and varying clinical characteristics. Clinical doctors must be aware of these cases, especially when their patients present an atypical clinical course, and reappraise their medical management. Hippokratia 2015; 19 (2):182-185. PMID:27418771

  17. Complete genome sequence, lifestyle, and multi-drug resistance of the human pathogen Corynebacterium resistens DSM 45100 isolated from blood samples of a leukemia patient

    PubMed Central

    2012-01-01

    Background Corynebacterium resistens was initially recovered from human infections and recognized as a new coryneform species that is highly resistant to antimicrobial agents. Bacteremia associated with this organism in immunocompromised patients was rapidly fatal as standard minocycline therapies failed. C. resistens DSM 45100 was isolated from a blood culture of samples taken from a patient with acute myelocytic leukemia. The complete genome sequence of C. resistens DSM 45100 was determined by pyrosequencing to identify genes contributing to multi-drug resistance, virulence, and the lipophilic lifestyle of this newly described human pathogen. Results The genome of C. resistens DSM 45100 consists of a circular chromosome of 2,601,311 bp in size and the 28,312-bp plasmid pJA144188. Metabolic analysis showed that the genome of C. resistens DSM 45100 lacks genes for typical sugar uptake systems, anaplerotic functions, and a fatty acid synthase, explaining the strict lipophilic lifestyle of this species. The genome encodes a broad spectrum of enzymes ensuring the availability of exogenous fatty acids for growth, including predicted virulence factors that probably contribute to fatty acid metabolism by damaging host tissue. C. resistens DSM 45100 is able to use external L-histidine as a combined carbon and nitrogen source, presumably as a result of adaptation to the hitherto unknown habitat on the human skin. Plasmid pJA144188 harbors several genes contributing to antibiotic resistance of C. resistens DSM 45100, including a tetracycline resistance region of the Tet W type known from Lactobacillus reuteri and Streptococcus suis. The tet(W) gene of pJA144188 was cloned in Corynebacterium glutamicum and was shown to confer high levels of resistance to tetracycline, doxycycline, and minocycline in vitro. Conclusions The detected gene repertoire of C. resistens DSM 45100 provides insights into the lipophilic lifestyle and virulence functions of this newly recognized

  18. Molecular characterization of Streptococcus agalactiae and Streptococcus uberis isolates from bovine milk.

    PubMed

    Shome, Bibek Ranjan; Bhuvana, Mani; Mitra, Susweta Das; Krithiga, Natesan; Shome, Rajeswari; Velu, Dhanikachalam; Banerjee, Apala; Barbuddhe, Sukhadeo B; Prabhudas, Krishnamshetty; Rahman, Habibar

    2012-12-01

    Streptococci are one among the major mastitis pathogens which have a considerable impact on cow health, milk quality, and productivity. The aim of the present study was to investigate the occurrence and virulence characteristics of streptococci from bovine milk and to assess the molecular epidemiology and population structure of the Indian isolates using multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). Out of a total of 209 bovine composite milk samples screened from four herds (A-D), 30 Streptococcus spp. were isolated from 29 milk samples. Among the 30 isolates, species-specific PCR and partial 16S rRNA gene sequence analysis identified 17 Streptococcus agalactiae arising from herd A and 13 Streptococcus uberis comprising of 5, 7, and 1 isolates from herds B, C, and D respectively. PCR based screening for virulence genes revealed the presence of the cfb and the pavA genes in 17 and 1 S. agalactiae isolates, respectively. Similarly, in S. uberis isolates, cfu gene was present in six isolates from herd C, the pau A/skc gene in all the isolates from herds B, C, and D, whereas the sua gene was present in four isolates from herd B and the only isolate from herd D. On MLST analysis, all the S. agalactiae isolates were found to be of a novel sequence type (ST), ST-483, reported for the first time and is a single locus variant of the predicted subgroup founder ST-310, while the S. uberis isolates were found to be of three novel sequence types, namely ST-439, ST-474, and ST-475, all reported for the first time. ST-474 was a double locus variant of three different STs of global clonal complex ST-143 considered to be associated with clinical and subclinical mastitis, but ST-439 and ST-475 were singletons. Unique sequence types identified for both S. agalactiae and S. uberis were found to be herd specific. On PFGE analysis, identical or closely related restriction patterns for S. agalactiae ST-483 and S. uberis ST-439 in herds A and B

  19. Thermoregulation of Capsule Production by Streptococcus pyogenes

    PubMed Central

    Kang, Song Ok; Wright, Jordan O.; Tesorero, Rafael A.; Lee, Hyunwoo; Beall, Bernard; Cho, Kyu Hong

    2012-01-01

    The capsule of Streptococcus pyogenes serves as an adhesin as well as an anti-phagocytic factor by binding to CD44 on keratinocytes of the pharyngeal mucosa and the skin, the main entry sites of the pathogen. We discovered that S. pyogenes HSC5 and MGAS315 strains are further thermoregulated for capsule production at a post-transcriptional level in addition to the transcriptional regulation by the CovRS two-component regulatory system. When the transcription of the hasABC capsular biosynthetic locus was de-repressed through mutation of the covRS system, the two strains, which have been used for pathogenesis studies in the laboratory, exhibited markedly increased capsule production at sub-body temperature. Employing transposon mutagenesis, we found that CvfA, a previously identified membrane-associated endoribonuclease, is required for the thermoregulation of capsule synthesis. The mutation of the cvfA gene conferred increased capsule production regardless of temperature. However, the amount of the capsule transcript was not changed by the mutation, indicating that a post-transcriptional regulator mediates between CvfA and thermoregulated capsule production. When we tested naturally occurring invasive mucoid strains, a high percentage (11/53, 21%) of the strains exhibited thermoregulated capsule production. As expected, the mucoid phenotype of these strains at sub-body temperature was due to mutations within the chromosomal covRS genes. Capsule thermoregulation that exhibits high capsule production at lower temperatures that occur on the skin or mucosal surface potentially confers better capability of adhesion and invasion when S. pyogenes penetrates the epithelial surface. PMID:22615992

  20. Thermoregulation of capsule production by Streptococcus pyogenes.

    PubMed

    Kang, Song Ok; Wright, Jordan O; Tesorero, Rafael A; Lee, Hyunwoo; Beall, Bernard; Cho, Kyu Hong

    2012-01-01

    The capsule of Streptococcus pyogenes serves as an adhesin as well as an anti-phagocytic factor by binding to CD44 on keratinocytes of the pharyngeal mucosa and the skin, the main entry sites of the pathogen. We discovered that S. pyogenes HSC5 and MGAS315 strains are further thermoregulated for capsule production at a post-transcriptional level in addition to the transcriptional regulation by the CovRS two-component regulatory system. When the transcription of the hasABC capsular biosynthetic locus was de-repressed through mutation of the covRS system, the two strains, which have been used for pathogenesis studies in the laboratory, exhibited markedly increased capsule production at sub-body temperature. Employing transposon mutagenesis, we found that CvfA, a previously identified membrane-associated endoribonuclease, is required for the thermoregulation of capsule synthesis. The mutation of the cvfA gene conferred increased capsule production regardless of temperature. However, the amount of the capsule transcript was not changed by the mutation, indicating that a post-transcriptional regulator mediates between CvfA and thermoregulated capsule production. When we tested naturally occurring invasive mucoid strains, a high percentage (11/53, 21%) of the strains exhibited thermoregulated capsule production. As expected, the mucoid phenotype of these strains at sub-body temperature was due to mutations within the chromosomal covRS genes. Capsule thermoregulation that exhibits high capsule production at lower temperatures that occur on the skin or mucosal surface potentially confers better capability of adhesion and invasion when S. pyogenes penetrates the epithelial surface. PMID:22615992

  1. Pathogen presence in feral pigs and their movement around two commercial piggeries in Queensland, Australia.

    PubMed

    Pearson, H E; Toribio, J-A L M L; Hernandez-Jover, M; Marshall, D; Lapidge, S J

    2014-03-29

    Feral pigs are wild animal reservoirs of infectious pathogens transmissible to other species, all of which are transmissible to domestic pigs. The objective of this study was to detect the presence of harmful production-limiting pathogens; Brucella suis, Leptospira species, Lawsonia intracellularis, Mycoplasma hyopneumoniae and Actinobacillus pleuropneumoniae in a feral pig population within a 10 km radius of two large-scale commercial piggeries in Southern Queensland, Australia. The movement pattern of six pigs within the feral population was also investigated using geographic positioning system collars. All pathogens were present in the feral pig population except for A pleuropneumoniae. The true seroprevalence (TP) from 83 serum samples was 10.5 per cent for B suis, 48.6 per cent for Leptospira species, 100 per cent for L intracellularis and 42.1 per cent for M hyopneumoniae. Of 72 lung samples, 27.6 per cent were positive for M hyopneumoniae. Serum samples from 86 domestic sows within the study region were positive for Leptospira species (TP 2.1 per cent), L intracellularis (TP 100 per cent) and M hyopneumoniae (TP 100 per cent). The majority of feral pig movement was within 5 km of the piggeries, with one approaching to 100 m of the free-range piggery. The presence of pathogens in feral pigs in such close proximity to commercial piggeries could pose a biosecurity risk. PMID:24572722

  2. Phylogenomics and the Dynamic Genome Evolution of the Genus Streptococcus

    PubMed Central

    Richards, Vincent P.; Palmer, Sara R.; Pavinski Bitar, Paulina D.; Qin, Xiang; Weinstock, George M.; Highlander, Sarah K.; Town, Christopher D.; Burne, Robert A.; Stanhope, Michael J.

    2014-01-01

    The genus Streptococcus comprises important pathogens that have a severe impact on human health and are responsible for substantial economic losses to agriculture. Here, we utilize 46 Streptococcus genome sequences (44 species), including eight species sequenced here, to provide the first genomic level insight into the evolutionary history and genetic basis underlying the functional diversity of all major groups of this genus. Gene gain/loss analysis revealed a dynamic pattern of genome evolution characterized by an initial period of gene gain followed by a period of loss, as the major groups within the genus diversified. This was followed by a period of genome expansion associated with the origins of the present extant species. The pattern is concordant with an emerging view that genomes evolve through a dynamic process of expansion and streamlining. A large proportion of the pan-genome has experienced lateral gene transfer (LGT) with causative factors, such as relatedness and shared environment, operating over different evolutionary scales. Multiple gene ontology terms were significantly enriched for each group, and mapping terms onto the phylogeny showed that those corresponding to genes born on branches leading to the major groups represented approximately one-fifth of those enriched. Furthermore, despite the extensive LGT, several biochemical characteristics have been retained since group formation, suggesting genomic cohesiveness through time, and that these characteristics may be fundamental to each group. For example, proteolysis: mitis group; urea metabolism: salivarius group; carbohydrate metabolism: pyogenic group; and transcription regulation: bovis group. PMID:24625962

  3. [Streptococcus pyogenes and the brain: living with the enemy].

    PubMed

    Dale, R C

    Streptococcus pyogenes (or group A beta hemolytic streptococcus) is a pathogenic bacterium that can give rise to a range of invasive and autoimmune diseases, although it is more widely known as the cause of tonsillitis. It is particularly interesting to note that this germ only causes disease in humans. For many years it has been acknowledged that it can cause an autoimmune brain disease (Sydenham s chorea). Yet, the spectrum of post streptococcal brain disorders has recently been extended to include other movement disorders such as tics or dystonia. A number of systematic psychiatric studies have shown that certain emotional disorders generally accompany the movement disorder (particularly, obsessive compulsive disorder). The proposed pathogenetic mechanism is that of a neuronal dysfunction in which antibodies play a mediating role. The antibodies that are produced after the streptococcal infection cross react with neuronal proteins, and more especially so in individuals with a propensity. This represents a possible model of immunological mimicry and its potential importance with respect to certain idiopathic disorders such as Tourette syndrome and obsessive compulsive disorder. PMID:12861520

  4. Mechanisms of group A Streptococcus resistance to reactive oxygen species.

    PubMed

    Henningham, Anna; Döhrmann, Simon; Nizet, Victor; Cole, Jason N

    2015-07-01

    Streptococcus pyogenes, also known as group A Streptococcus (GAS), is an exclusively human Gram-positive bacterial pathogen ranked among the 'top 10' causes of infection-related deaths worldwide. GAS commonly causes benign and self-limiting epithelial infections (pharyngitis and impetigo), and less frequent severe invasive diseases (bacteremia, toxic shock syndrome and necrotizing fasciitis). Annually, GAS causes 700 million infections, including 1.8 million invasive infections with a mortality rate of 25%. In order to establish an infection, GAS must counteract the oxidative stress conditions generated by the release of reactive oxygen species (ROS) at the infection site by host immune cells such as neutrophils and monocytes. ROS are the highly reactive and toxic byproducts of oxygen metabolism, including hydrogen peroxide (H2O2), superoxide anion (O2•(-)), hydroxyl radicals (OH•) and singlet oxygen (O2*), which can damage bacterial nucleic acids, proteins and cell membranes. This review summarizes the enzymatic and regulatory mechanisms utilized by GAS to thwart ROS and survive under conditions of oxidative stress. PMID:25670736

  5. Comparative genomic analysis of ten Streptococcus pneumoniae temperate bacteriophages.

    PubMed

    Romero, Patricia; Croucher, Nicholas J; Hiller, N Luisa; Hu, Fen Z; Ehrlich, Garth D; Bentley, Stephen D; García, Ernesto; Mitchell, Tim J

    2009-08-01

    Streptococcus pneumoniae is an important human pathogen that often carries temperate bacteriophages. As part of a program to characterize the genetic makeup of prophages associated with clinical strains and to assess the potential roles that they play in the biology and pathogenesis in their host, we performed comparative genomic analysis of 10 temperate pneumococcal phages. All of the genomes are organized into five major gene clusters: lysogeny, replication, packaging, morphogenesis, and lysis clusters. All of the phage particles observed showed a Siphoviridae morphology. The only genes that are well conserved in all the genomes studied are those involved in the integration and the lysis of the host in addition to two genes, of unknown function, within the replication module. We observed that a high percentage of the open reading frames contained no similarities to any sequences catalogued in public databases; however, genes that were homologous to known phage virulence genes, including the pblB gene of Streptococcus mitis and the vapE gene of Dichelobacter nodosus, were also identified. Interestingly, bioinformatic tools showed the presence of a toxin-antitoxin system in the phage phiSpn_6, and this represents the first time that an addition system in a pneumophage has been identified. Collectively, the temperate pneumophages contain a diverse set of genes with various levels of similarity among them. PMID:19502408

  6. Streptococcus anginosus (milleri) Group Strains Isolated in Poland (1996-2012) and their Antibiotic Resistance Patterns.

    PubMed

    Obszańska, Katarzyna; Kern-Zdanowicz, Izabella; Kozińska, Aleksandra; Machura, Katarzyna; Stefaniuk, Elzbieta; Hryniewicz, Waleria; Sitkiewicz, Izabela

    2016-01-01

    Streptococcus anginosus, Streptococcus intermedius and Streptococcus constellatus form a group of related streptococcal species, namely the Streptococcus Anginosus Group (SAG). The group, previously called "milleri" had been rarely described until 1980/1990 as source of infections. Nowadays SAG bacteria are often described as pathogens causing predominantly purulent infections. The number of infections is highly underestimated, as SAG strains are often classified in the microbiology laboratory as less virulent "viridans streptococci" Epidemiological situation regarding SAG infections in Poland has been unrecognized, therefore we performed a retrospective analysis of strains isolated between 1996 and 2012. Strains suspected of belonging to SAG were re-identified using an automated biochemical approach (Vitek2) and MALDI-TOF MS. We performed first analysis of antibiotic resistance among SAG strains isolated in Poland using automated methods (Vitek2), disk diffusion tests and E-Tests. We also performed PCR detection of resistance determinants in antibiotic resistant strains. Clonal structure of analyzed strains was evaluated with PFGE and MLVF methods. All three species are difficult to distinguish using automated diagnostic methods and the same is true for automated MIC evaluation. Our analysis revealed SAG strains are rarely isolated in Poland, predominantly from purulent infections. All isolates are very diverse on the genomic level as estimated by PFGE and MLVF analyses. All analyzed strains are sensitive to penicillin, a substantial group of strains is resistant to macrolides and the majority of strains are resistant to tetracycline. PMID:27281992

  7. Structural analysis of the lipoteichoic acids isolated from bovine mastitis Streptococcus uberis 233, Streptococcus dysgalactiae 2023 and Streptococcus agalactiae 0250.

    PubMed

    Czabańska, Anna; Neiwert, Olga; Lindner, Buko; Leigh, James; Holst, Otto; Duda, Katarzyna A

    2012-11-01

    Lipoteichoic acid (LTA) is an amphiphilic polycondensate located in the cell envelope of Gram-positive bacteria. In this study, LTAs were isolated from the three bovine mastitis species Streptococcus uberis 233, Streptococcus dysgalactiae 2023, and Streptococcus agalactiae 0250. Structural investigations of these LTAs were performed applying 1D and 2D nuclear magnetic resonance experiments as well as chemical analyses and mass spectrometry. Compositional analysis revealed the presence of glycerol (Gro), Glc, alanine (Ala), and 16:0, 16:1, 18:0, 18:1. The LTAs of the three Streptococcus strains possessed the same structure, that is, a lipid anchor comprised of α-Glcp-(1→2)-α-Glcp-(1→3)-1,2-diacyl-sn-Gro and the hydrophilic backbone consisting of poly(sn-Gro-1-phosphate) randomly substituted at O-2 of Gro by d-Ala. PMID:23036931

  8. Faecal microbiota transplantation: a sui generis biological drug, not a tissue.

    PubMed

    Megerlin, F; Fouassier, E; Lopert, R; Bourlioux, P

    2014-07-01

    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. PMID:24997882

  9. Dose-dependent establishment of Trichuris suis larvae in Göttingen minipigs.

    PubMed

    Vejzagić, Nermina; Roepstorff, Allan; Kringel, Helene; Thamsborg, Stig Milan; Nielsen, Mads Pårup; Kapel, Christian M O

    2015-03-15

    Embryonated eggs of the pig whipworm Trichuris suis (TSOee) constitute the active pharmaceutical ingredient (API) in a medicinal product explored in human clinical trials against several immune-mediated diseases. The measurement of TSO biological potency (hatchability and infectivity) is a requirement for the assessment of TSO's pharmacological potency in human clinical trials. The present study aims to validate the dose-dependent establishment of T. suis larvae in Göttingen minipigs and eventual clinical implication of a dose range (1000-10,000 TSO). Four groups of 5 minipigs were inoculated with doses of 1000, 2500, 7500, and 10,000 TSOee, respectively, to evaluate a range of concentrations of TSOee in a minipig infectivity model. Unembryonated eggs (TSOue) were added to keep the total egg number in the inoculum constant at 10,000 eggs. Two groups received 2500 and 7500 TSOee per pig without the addition of TSOue as controls. The intestinal larval establishment at 21 days post inoculation (dpi) demonstrated a clear positive linear dose-response relationship between numbers of inoculated TSOee and recovered larvae. There was a low level of variation in larval counts in all study groups. Thus, the infectivity model in minipigs within the tested dose range offers a reliable, sensitive and accurate assay for testing biological potency of TSO. PMID:25700937

  10. Effect of toltrazuril treatment in nursing piglets naturally infected with Isospora suis.

    PubMed

    Skampardonis, Vasilis; Sotiraki, Smaragda; Kostoulas, Polychronis; Leontides, Leonidas

    2010-08-27

    Isospora suis is an important parasitic infection in intensive pig production worldwide, responsible for significant economic losses. In this study the efficacy of toltrazuril treatment against isosporosis was evaluated, under field conditions and throughout the nursing period, in reducing (i) the mean time to onset of diarrhoea and oocyst excretion, (ii) the odds of diarrhoea and, (iii) the odds and level of oocyst excretion, adjusting for the heterogeneity of I. suis infection among litters and across time. In a 300-sow farrow-to-finish commercial operation, twenty-five litters were randomly allocated to receive toltrazuril (thirteen litters) or no treatment (twelve litters). The course of infection was followed in all piglets by coprological examination from day 6 after farrowing until weaning. Parametric shared frailty models, generalised linear mixed models and a two-part random effects model were used in the analyses. Treated piglets had longer mean time to onset of oocyst excretion, lower odds of excreting oocysts and lower mean amount of excreted oocysts on any day during the nursing period. Diarrhoea was less likely to occur in treated piglets. Variance partition coefficients revealed that almost half of the variation in the odds of oocyst excretion and diarrhoea was ascribed to unknown or unmeasured factors that operate at higher than the piglet levels of aggregation. Thus, beyond toltrazuril treatment, control of isosporosis in commercial pig farms can be improved by identification and quantification of these factors. PMID:20471754

  11. Brucella suis bacteremia misidentified as Ochrobactrum anthropi by the VITEK 2 system.

    PubMed

    Vila, Andrea; Pagella, Hugo; Vera Bello, Gonzalo; Vicente, Alicia

    2016-01-01

    Ochrobactrum and Brucella are genetically related genera of the family Brucellaceae, sharing 98.8% rRNA similarity. Because of their phenotypic similarity, Ochrobactrum can be miscoded as Brucella by automated identification systems. The misidentification on blood cultures (BCs) of B. suis as O. anthropi by the VITEK 2 system is herein described. A 67-year-old male with a prosthetic mitral valve and fever was admitted with bacteremia due to a Gram-negative coccobacillus identified as O. anthropi by VITEK 2. The patient's fever persisted along with positive blood cultures despite specific antimicrobial treatment. Due to this adverse outcome, the patient was interrogated again and admitted having domestic swine. Serological tests were positive for acute brucellosis. Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) of BC strains identified B. suis biovar 1. Timely identification of Brucella is essential for providing proper treatment to the patient and for advising safe handling of laboratory cultures in biological safety cabinets to prevent laboratory-acquired infection. Countries where brucellosis is endemic must be aware of this possibility. PMID:27131010

  12. Trichuris suis ova: testing a helminth-based therapy as an extension of the hygiene hypothesis.

    PubMed

    Jouvin, Marie-Hélène; Kinet, Jean-Pierre

    2012-07-01

    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. PMID:22742834

  13. Beta-hemolytic Streptococcus dysgalactiae strains isolated from horses are a genetically distinct population within the Streptococcus dysgalactiae taxon

    PubMed Central

    Pinho, Marcos D.; Erol, Erdal; Ribeiro-Gonçalves, Bruno; Mendes, Catarina I.; Carriço, João A.; Matos, Sandra C.; Preziuso, Silvia; Luebke-Becker, Antina; Wieler, Lothar H.; Melo-Cristino, Jose; Ramirez, Mario

    2016-01-01

    The pathogenic role of beta-hemolytic Streptococcus dysgalactiae in the equine host is increasingly recognized. A collection of 108 Lancefield group C (n = 96) or L (n = 12) horse isolates recovered in the United States and in three European countries presented multilocus sequence typing (MLST) alleles, sequence types and emm types (only 56% of the isolates could be emm typed) that were, with few exceptions, distinct from those previously found in human Streptococcus dysgalactiae subsp. equisimilis. Characterization of a subset of horse isolates by multilocus sequence analysis (MLSA) and 16S rRNA gene sequence showed that most equine isolates could also be differentiated from S. dysgalactiae strains from other animal species, supporting the existence of a horse specific genomovar. Draft genome information confirms the distinctiveness of the horse genomovar and indicates the presence of potentially horse-specific virulence factors. While this genomovar represents most of the isolates recovered from horses, a smaller MLST and MLSA defined sub-population seems to be able to cause infections in horses, other animals and humans, indicating that transmission between hosts of strains belonging to this group may occur. PMID:27530432

  14. Beta-hemolytic Streptococcus dysgalactiae strains isolated from horses are a genetically distinct population within the Streptococcus dysgalactiae taxon.

    PubMed

    Pinho, Marcos D; Erol, Erdal; Ribeiro-Gonçalves, Bruno; Mendes, Catarina I; Carriço, João A; Matos, Sandra C; Preziuso, Silvia; Luebke-Becker, Antina; Wieler, Lothar H; Melo-Cristino, Jose; Ramirez, Mario

    2016-01-01

    The pathogenic role of beta-hemolytic Streptococcus dysgalactiae in the equine host is increasingly recognized. A collection of 108 Lancefield group C (n = 96) or L (n = 12) horse isolates recovered in the United States and in three European countries presented multilocus sequence typing (MLST) alleles, sequence types and emm types (only 56% of the isolates could be emm typed) that were, with few exceptions, distinct from those previously found in human Streptococcus dysgalactiae subsp. equisimilis. Characterization of a subset of horse isolates by multilocus sequence analysis (MLSA) and 16S rRNA gene sequence showed that most equine isolates could also be differentiated from S. dysgalactiae strains from other animal species, supporting the existence of a horse specific genomovar. Draft genome information confirms the distinctiveness of the horse genomovar and indicates the presence of potentially horse-specific virulence factors. While this genomovar represents most of the isolates recovered from horses, a smaller MLST and MLSA defined sub-population seems to be able to cause infections in horses, other animals and humans, indicating that transmission between hosts of strains belonging to this group may occur. PMID:27530432

  15. An Unusual Cause of Flexor Tenosynovitis: Streptococcus mitis

    PubMed Central

    Ulucay, Cağatay; Ozler, Turhan

    2014-01-01

    Summary: Streptococcus mitis is a commensal organism of the human oropharynx that rarely causes infection in healthy individuals. Herein, we describe a previously healthy 35-year-old woman who presented with acute pyogenic flexor tenosynovitis of the left index finger due to S. mitis infection. The patient’s infection was treated successfully via surgical and medical interventions, and during follow-up, it was determined that she was complement component C3 deficient. Tenosynovitis is an emergent clinical syndrome that can result in permanent disability or amputation. To the best of our knowledge, this case report is the first to describe tenosynovitis due to S. mitis; in addition, it highlights the importance of initiating therapy with antibiotics that are effective against this rare pathogen. PMID:25587497

  16. Cationic Antimicrobial Peptides Disrupt the Streptococcus pyogenes ExPortal

    PubMed Central

    Vega, Luis Alberto; Caparon, Michael G.

    2012-01-01

    Summary Although they possess a well-characterized ability to porate the bacterial membrane, emerging research suggests that cationic antimicrobial peptides (CAPs) can influence pathogen behavior at levels that are sub-lethal. In this study, we investigated the interaction of polymyxin B and human neutrophil peptide (HNP-1) with the human pathogen Streptococcus pyogenes. At sub-lethal concentrations, these CAPs preferentially targeted the ExPortal, a unique microdomain of the S. pyogenes membrane, specialized for protein secretion and processing. A consequence of this interaction was the disruption of ExPortal organization and a redistribution of ExPortal components into the peripheral membrane. Redistribution was associated with inhibition of secretion of certain toxins, including the SpeB cysteine protease and the Streptolysin O (SLO) cytolysin, but not SIC, a protein that protects S. pyogenes from CAPs. These data suggest a novel function for CAPs in targeting the ExPortal and interfering with secretion of factors required for infection and survival. This mechanism may prove valuable for the design of new types of antimicrobial agents to combat the emergence of antibiotic-resistant pathogens. PMID:22780862

  17. Structural and Functional Analysis of Cell Wall-anchored Polypeptide Adhesin BspA in Streptococcus agalactiae.

    PubMed

    Rego, Sara; Heal, Timothy J; Pidwill, Grace R; Till, Marisa; Robson, Alice; Lamont, Richard J; Sessions, Richard B; Jenkinson, Howard F; Race, Paul R; Nobbs, Angela H

    2016-07-29

    Streptococcus agalactiae (group B Streptococcus, GBS) is the predominant cause of early-onset infectious disease in neonates and is responsible for life-threatening infections in elderly and immunocompromised individuals. Clinical manifestations of GBS infection include sepsis, pneumonia, and meningitis. Here, we describe BspA, a deviant antigen I/II family polypeptide that confers adhesive properties linked to pathogenesis in GBS. Heterologous expression of BspA on the surface of the non-adherent bacterium Lactococcus lactis confers adherence to scavenger receptor gp340, human vaginal epithelium, and to the fungus Candida albicans Complementary crystallographic and biophysical characterization of BspA reveal a novel β-sandwich adhesion domain and unique asparagine-dependent super-helical stalk. Collectively, these findings establish a new bacterial adhesin structure that has in effect been hijacked by a pathogenic Streptococcus species to provide competitive advantage in human mucosal infections. PMID:27311712

  18. Pathogenic alteration in severe burn wounds.

    PubMed

    Fu, Yang; Xie, Bing; Ben, DaoFeng; Lv, KaiYang; Zhu, ShiHui; Lu, Wei; Tang, HongTai; Cheng, DaSheng; Ma, Bing; Wang, GuangYi; Xiao, ShiChu; Wang, GuangQing; Xia, ZhaoFan

    2012-02-01

    The present study aims to define the trend of time related changes with local bacterial alteration of bacterial resistance in severe burns in our burn center during a 12-year period. Retrospective analysis of microbiological results on severely burned wounds between 1998 and 2009 was carried out. A study of 3615 microbial isolates was performed. Staphylococcus aureus was the most commonly isolated pathogen (38.2%) followed by A. baumannii (16.2%), Streptococcus viridans (11.4%), Pseudomonas aeruginosa (10.4%), coagulase-negative staphylococci (CNS, 9.2%). The species ratios of S. aureus and A. baumannii increased significantly from 1st to 8th week of hospitalization, while those of Streptococcus viridans, P. aeruginosa and coagulase-negative staphylococci decreased during the same period. Bacterial resistance rates were compared between the periods 1998-2003 and 2004-2009. Vancomycin remained as the most sensitive antibiotic in S. aureus including methicillin-resistant S. aureus (MRSA). It was very likely that the majority of infections caused by Streptococcus viridans, P. aeruginosa and coagulase-negative staphylococci occurred in the early stage of burn course and the majority of infections caused by A. baumannii occurred 4 weeks after admission. The use of different antibiotics was probably the major contributor to these trends. PMID:22100426

  19. Immune Responses and Protection against Experimental Brucella suis Biovar 1 Challenge in Nonvaccinated or B. abortus Strain RB51-Vaccinated Cattle▿

    PubMed Central

    Olsen, S. C.; Hennager, S. G.

    2010-01-01

    Twenty Hereford heifers approximately 9 months of age were vaccinated with saline (control) or 2 × 1010 CFU of the Brucella abortus strain RB51 (RB51) vaccine. Immunologic responses after inoculation demonstrated significantly greater (P < 0.05) antibody and proliferative responses to RB51 antigens in cattle vaccinated with RB51 than in the controls. Pregnant cattle received a conjunctival challenge at approximately 6 months of gestation with 107 CFU of B. suis bv. 1 strains isolated from naturally infected cattle. The fluorescence polarization assay and the buffered acid plate agglutination test had the highest sensitivities in detecting B. suis-infected cattle between 2 and 12 weeks after experimental infection. Serologic responses and lymphocyte proliferative responses to B. suis antigens did not differ between control and RB51 vaccinees after experimental infection. No abortions occurred in cattle in either treatment group after challenge, although there appeared to be an increased incidence of retained placenta after parturition in both the control and the RB51 vaccination treatment groups. Our data suggest that the mammary gland is a preferred site for B. suis localization in cattle. Vaccination with RB51 did not reduce B. suis infection rates in maternal or fetal tissues. In conclusion, although B. suis is unlikely to cause abortions and fetal losses in cattle, our data suggest that RB51 vaccination will not protect cattle against B. suis infection after exposure. PMID:20943881

  20. Complete Genome Sequences of Two Central European Brucella suis bv. 2 Haplotype 2c Strains Isolated from Wild Boars

    PubMed Central

    Ferreira, Ana Cristina; Tenreiro, Rogério; Corrêa de Sá, Maria Inácia

    2014-01-01

    The Brucella suis haplotype 2c is commonly isolated from wild boars and domestic pigs across Central Europe, though it is rarely described in the Iberian Peninsula. We report here the complete and annotated genome sequences of two haplotype 2c strains isolated from wild boars in the northeast region of Spain, above the Ebro River. PMID:25013144

  1. Draft Genome Sequence of Helicobacter suis Strain SNTW101, Isolated from a Japanese Patient with Nodular Gastritis.

    PubMed

    Matsui, Hidenori; Takahashi, Tetsufumi; Murayama, Somay Y; Uchiyama, Ikuo; Yamaguchi, Katsushi; Shigenobu, Shuji; Suzuki, Masato; Rimbara, Emiko; Shibayama, Keigo; Øverby, Anders; Nakamura, Masahiko

    2016-01-01

    We present here the draft whole-genome shotgun sequence of an uncultivated strain SNTW101 of Helicobacter suis, which has been maintained in the stomachs of mice. This strain was originally isolated from gastric biopsy specimens of a urea breath test-negative Japanese patient suffering from nodular gastritis. PMID:27609915

  2. A repA-based ELISA for discriminating cattle vaccinated with Brucella suis 2 from those naturally infected with Brucella abortus and Brucella melitensis.

    PubMed

    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

    2014-01-01

    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. PMID:24941369

  3. Mannitol transport in Streptococcus mutans.

    PubMed Central

    Maryanski, J H; Wittenberger, C L

    1975-01-01

    A hexitol-inducible, phosphoenolpyruvate-dependent phosphotransferase system was demonstrated in Streptococcus mutans. Cell-free extracts obtained from mannitol-grown cells from a representative strain of each of the five S. mutans serotypes (AHT, BHT, C-67-1, 6715, and LM7) were capable of converting mannitol to mannitol-1-phosphate by a reaction which required phosphoenolpyruvate and Mg2+. Mannitol and sorbitol phosphotransferase activities were found in cell-free extracts prepared from cells grown on the respective substrate, but neither hexitol phosphotransferase activity was present in extracts obtained from cells grown on other substrates examined. A heat-stable, low-molecular-weight component was partially purified from glucose-grown cells and found to stimulate the mannitol phosphotransferase system. Divalent cations Mn2+ and Ca2+ partially replaced Mg2+, while Zn2+ was found to be highly inhibitory. PMID:1194241

  4. Streptolysin S of Streptococcus anginosus exhibits broad-range hemolytic activity.

    PubMed

    Asam, Daniela; Mauerer, Stefanie; Spellerberg, Barbara

    2015-04-01

    Streptococcus anginosus is a commensal of mucous membranes and an emerging human pathogen. Some strains, including the type strain, display a prominent β-hemolytic phenotype. A gene cluster (sag), encoding a variant of streptolysin S (SLS) has recently been identified as the genetic background for β-hemolysin production in S. anginosus. In this study, we further characterized the hemolytic and cytolytic activity of the S. anginosus hemolysin in comparison with other streptococcal hemolysins. The results indicate that SLS of S. anginosus is a broad-range hemolysin able to lyse erythrocytes of different species, including horse, bovine, rabbit and even chicken. The hemolytic activity is temperature dependent, and a down-regulation of the hemolysin expression is induced in the presence of high glucose levels. Survival assays indicate that in contrast to other streptococcal species, S. anginosus does not require SLS for survival in the presence of human granulocytes. Cross-complementation studies using the sagB and sagD genes of Streptococcus pyogenes and Streptococcus dysgalactiae subsp. equisimilis demonstrated functional similarities to the S. anginosus SLS. Nevertheless, distinct differences to other streptolysin S variants were noted and provide further insights into the molecular mechanisms of SLS pathogen host interactions. PMID:25381594

  5. Spectroscopic Method for Fast and Accurate Group A Streptococcus Bacteria Detection.

    PubMed

    Schiff, Dillon; Aviv, Hagit; Rosenbaum, Efraim; Tischler, Yaakov R

    2016-02-16

    Rapid and accurate detection of pathogens is paramount to human health. Spectroscopic techniques have been shown to be viable methods for detecting various pathogens. Enhanced methods of Raman spectroscopy can discriminate unique bacterial signatures; however, many of these require precise conditions and do not have in vivo replicability. Common biological detection methods such as rapid antigen detection tests have high specificity but do not have high sensitivity. Here we developed a new method of bacteria detection that is both highly specific and highly sensitive by combining the specificity of antibody staining and the sensitivity of spectroscopic characterization. Bacteria samples, treated with a fluorescent antibody complex specific to Streptococcus pyogenes, were volumetrically normalized according to their Raman bacterial signal intensity and characterized for fluorescence, eliciting a positive result for samples containing Streptococcus pyogenes and a negative result for those without. The normalized fluorescence intensity of the Streptococcus pyogenes gave a signal that is up to 16.4 times higher than that of other bacteria samples for bacteria stained in solution and up to 12.7 times higher in solid state. This method can be very easily replicated for other bacteria species using suitable antibody-dye complexes. In addition, this method shows viability for in vivo detection as it requires minute amounts of bacteria, low laser excitation power, and short integration times in order to achieve high signal. PMID:26752013

  6. Frequency of Spontaneous Resistance to Peptide Deformylase Inhibitor GSK1322322 in Haemophilus influenzae, Staphylococcus aureus, Streptococcus pyogenes, and Streptococcus pneumoniae.

    PubMed

    Min, Sharon; Ingraham, Karen; Huang, Jianzhong; McCloskey, Lynn; Rilling, Sarah; Windau, Anne; Pizzollo, Jason; Butler, Deborah; Aubart, Kelly; Miller, Linda A; Zalacain, Magdalena; Holmes, David J; O'Dwyer, Karen

    2015-08-01

    The continuous emergence of multidrug-resistant pathogenic bacteria is compromising the successful treatment of serious microbial infections. GSK1322322, a novel peptide deformylase (PDF) inhibitor, shows good in vitro antibacterial activity and has demonstrated safety and efficacy in human proof-of-concept clinical studies. In vitro studies were performed to determine the frequency of resistance (FoR) to this antimicrobial agent in major pathogens that cause respiratory tract and skin infections. Resistance to GSK1322322 occurred at high frequency through loss-of-function mutations in the formyl-methionyl transferase (FMT) protein in Staphylococcus aureus (4/4 strains) and Streptococcus pyogenes (4/4 strains) and via missense mutations in Streptococcus pneumoniae (6/21 strains), but the mutations were associated with severe in vitro and/or in vivo fitness costs. The overall FoR to GSK1322322 was very low in Haemophilus influenzae, with only one PDF mutant being identified in one of four strains. No target-based mutants were identified from S. pyogenes, and only one or no PDF mutants were isolated in three of the four S. aureus strains studied. In S. pneumoniae, PDF mutants were isolated from only six of 21 strains tested; an additional 10 strains did not yield colonies on GSK1322322-containing plates. Most of the PDF mutants characterized from those three organisms (35/37 mutants) carried mutations in residues at or in close proximity to one of three highly conserved motifs that are part of the active site of the PDF protein, with 30 of the 35 mutations occurring at position V71 (using the S. pneumoniae numbering system). PMID:26014938

  7. PREVALENCE, PATHOLOGY, AND RISK FACTORS ASSOCIATED WITH STREPTOCOCCUS PHOCAE INFECTION IN SOUTHERN SEA OTTERS (ENHYDRA LUTRIS NEREIS), 2004-10.

    PubMed

    Bartlett, Georgina; Smith, Woutrina; Dominik, Clare; Batac, Francesca; Dodd, Erin; Byrne, Barbara A; Jang, Spencer; Jessup, David; Chantrey, Julian; Miller, Melissa

    2016-01-01

    Recent studies have implicated beta-hemolytic streptococci as opportunistic pathogens of marine mammals, including southern sea otters (Enhydra lutris nereis), but little is known about their prevalence or pathophysiology. Herein, we focus on risk factors for sea otter infection by a single beta-hemolytic streptococcal species, Streptococcus phocae. Streptococcus phocae was first identified as a marine mammal pathogen in 1994, and the first report in southern sea otters was in 2009. Its broad host range encompasses fish, pinnipeds, cetaceans, and mustelids, with S. phocae now recognized as an important pathogen of marine species worldwide. We assessed risk factors and lesion patterns for S. phocae infection in southern sea otters. Using archival necropsy data, S. phocae prevalence was 40.5% in fresh dead otters examined 2004-10. Skin trauma of any type was identified as a significant risk factor for S. phocae infection. The risk of infection was similar regardless of the cause and relative severity of skin trauma, including mating or fight wounds, shark bite, and anthropogenic trauma. Streptococcus phocae-infected sea otters were also more likely to present with abscesses or bacterial septicemia. Our findings highlight the importance of S. phocae as an opportunistic pathogen of sea otters and suggest that the most likely portal of entry is damaged skin. Even tiny skin breaks appear to facilitate bacterial colonization, invasion, abscess formation, and systemic spread. Our data provide important insights for management and care of marine species. PMID:26555115

  8. Population dynamics and intra-litter transmission patterns of Isospora suis in suckling piglets under on-farm conditions.

    PubMed

    Sotiraki, S; Roepstorff, A; Nielsen, J P; Maddox-Hyttel, C; Enøe, C; Boes, J; Murrell, K D; Thamsborg, S M

    2008-03-01

    The aim of this study was to investigate the intra-litter infection dynamics of Isospora suis under natural conditions, and to study any association between parasite transmission and the contamination level of the farrowing pen by applying different interventions in order to reduce the transmission of I. suis infection within the litter. The study was divided in 2 trials including in total 22 litters (254 piglets). The first trial included 4 litters (where standard procedures practiced routinely on the farm piglets were applied) and the piglets were followed coprologically from farrowing until 2 weeks after weaning. The sows of those litters were also examined at various intervals before and after farrowing. The second trial included the application of 3 different management procedures: (A) standard farm hygiene and management procedures, (B) standard farm hygiene and management procedures+the first piglets found to excrete I. suis oocysts in each pen were removed from the pen, and (C) reduced cleaning. Each procedure was studied in 2 litters. This was replicated 3 times to yield a total of 18 litters. The results suggested that (i) the sow does not play an important role in transmission of I. suis in the farrowing pen; (ii) in natural infections, both the age of the piglet age at onset of oocyst excretion and the oocyst excretion patterns may vary considerably; (iii) the course of oocyst excretion or development of diarrhoea is related to the time of initial infection and (iii) piglets, which are heavy at birth, are more prone to acquire I. suis infection. Moreover, it was demonstrated that cleaning could be an effective means of restricting the spread of the parasite within the litter and thus the development of diarrhoea. PMID:18021464

  9. Absence of capsule reveals glycan-mediated binding and recognition of salivary mucin MUC7 by Streptococcus pneumoniae.

    PubMed

    Thamadilok, S; Roche-Håkansson, H; Håkansson, A P; Ruhl, S

    2016-04-01

    Salivary proteins modulate bacterial colonization in the oral cavity and interact with systemic pathogens that pass through the oropharynx. An interesting example is the opportunistic respiratory pathogen Streptococcus pneumoniae that normally resides in the nasopharynx, but belongs to the greater Mitis group of streptococci, most of which colonize the oral cavity. Streptococcus pneumoniae also expresses a serine-rich repeat (SRR) adhesin, PsrP, which is a homologue to oral Mitis group SRR adhesins, such as Hsa of Streptococcus gordonii and SrpA of Streptococcus sanguinis. As the latter bind to salivary glycoproteins through recognition of terminal sialic acids, we wanted to determine whether S. pneumoniae also binds to salivary proteins through possibly the same mechanism. We found that only a capsule-free mutant of S. pneumoniae TIGR4 binds to salivary proteins, most prominently to mucin MUC7, but that this binding was not mediated through PsrP or recognition of sialic acid. We also found, however, that PsrP is involved in agglutination of human red blood cells (RBCs). After removal of PsrP, an additional previously masked lectin-like adhesin activity mediating agglutination of sialidase-treated RBCs becomes revealed. Using a custom-spotted glycoprotein and neoglycoprotein dot blot array, we identify candidate glycan motifs recognized by PsrP and by the putative S. pneumoniae adhesin that could perhaps be responsible for pneumococcal binding to salivary MUC7 and glycoproteins on RBCs. PMID:26172471

  10. Phenotypic and genotypic heterogeneity among Streptococcus iniae isolates recovered from cultured and wild fish in North America, Central America and the Caribbean Islands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus iniae, the etiological agent of streptococcosis in fish, is an important pathogen of cultured and wild fish worldwide. During the last decade outbreaks of streptococcosis have occurred in a wide range of cultured and wild fish in the Americas and Caribbean islands. To gain a better und...

  11. Septicemia with Streptococcus pseudopneumoniae: report of three cases with an apparent hepatic or bile duct association.

    PubMed

    Fuursted, Kurt; Littauer, Pia Jeanette; Greve, Thomas; Scholz, Christian F P

    2016-08-01

    Streptococcus pseudopneumoniae was described in 2004 as a new human pathogen, acknowledged in a range of clinical infections typically associated to the respiratory tract. This report demonstrates that S. pseudopneumoniae has the potential to cause invasive infection. In blood cultures from three patients, growth of an atypical Streptococcus pneumoniae (non-capsular, non-serotypeable, optochin susceptible under ambient atmosphere and bile-intermediately soluble) was recovered. All three patients had a history of a haematological disease (myelodysplastic syndrome and multiple myeloma) and an apparent origin of infection related to the liver or bile duct. All isolates were genome sequenced and subsequently identified as S. pseudopneumoniae by multi-locus sequence analysis (MLSA). Multi-locus sequence typing (MLST) based on the S. pneumoniae scheme revealed unknown sequence types and the antibiogram and resistome revealed no antibiotic resistance. PMID:27100044

  12. Quarter, cow, and farm risk factors for intramammary infections with major pathogens relative to minor pathogens in Thai dairy cows.

    PubMed

    Leelahapongsathon, Kansuda; Schukken, Ynte Hein; Suriyasathaporn, Witaya

    2014-08-01

    A cross-sectional study was carried out from May to September 2011 on 35 smallholder dairy farms in Chiang Mai, Thailand, to identify the quarter, cow, and farm factors that relate to intramammary infections (IMI) from major specified pathogens, compared to infections from minor pathogens. Data on general farm management, milking management, and dry cow management were recorded for each herd. Quarter milk samples were collected from either clinical or subclinical mastitis quarters. Dependent variables were binary data defining the specified major pathogens, including Streptococcus agalactiae (7.1 %), Streptococcus uberis (9.4 %), Streptococcus dysgalactiae (4.0 %), and other streptococci (16.7 %), as a case, and all minor pathogens as a control, in each dependent variable. The occurrence of S. agalactiae IMI was lower in first-parity cows and cows with short milking time. Cows with body condition score (BCS) <2.5 had higher occurrence of S. agalactiae IMI. The occurrence of S. uberis IMI was higher in quarters with California mastitis test (CMT) score 2, score 3, and having clinical mastitis and in farms with increasing age of vacuum system. Quarters with CMT score 3, having clinical mastitis, cow with manual milking after detaching milking cluster, and farms with high bulk milk somatic cell counts (BMSCC >500,000 cells/ml) had higher occurrence of S. dysgalactiae IMI. For other streptococci, quarters having clinical mastitis, BCS <2.5, and pulling down of milking cluster while milking increased occurrence of other streptococci IMI relative to minor pathogen IMI. These results highlight the importance of individual cow factors, milking characteristics, and BMSCC in determining the risk of IMI from major pathogens. PMID:24823898

  13. Management of Mesh Complications after SUI and POP Repair: Review and Analysis of the Current Literature

    PubMed Central

    Deng, D. Y.

    2015-01-01

    Purpose. To evaluate the surgical treatment concepts for the complications related to the implantation of mesh material for urogynecological indications. Materials and Methods. A review of the current literature on PubMed was performed. Results. Only retrospective studies were detected. The rate of mesh-related complications is about 15–25% and mesh erosion is up to 10% for POP and SUI repair. Mesh explantation is necessary in about 1-2% of patients due to complications. The initial approach appears to be an early surgical treatment with partial or complete mesh resection. Vaginal and endoscopic access for mesh resection is favored. Prior to recurrent surgeries, a careful examination and planning for the operation strategy are crucial. Conclusions. The data on the management of mesh complication is scarce. Revisions should be performed by an experienced surgeon and a proper follow-up with prospective documentation is essential for a good outcome. PMID:25973425

  14. Borrowed philosophy: bedside physicalism and the need for a sui generis metaphysic of medicine.

    PubMed

    Whatley, Shawn D

    2014-12-01

    The character of medicine has changed over the last 100 years such that medicine is more interested in diseases than the people who suffer from them. Despite notable efforts to address this, the medical humanities do not challenge doctors' fundamental view of the world. Students adopt a metaphysic of physicalism during basic science training that gets carried into medical training. While necessary for medical science, physicalism is insufficient for clinical care. Physicalism offers no foundation for the sine qua non of medicine, the doctor-patient relationship. The character of medicine will not see a renewed interest in humanity until educators address the insufficiency of physicalism for clinical care, and clinicians partner with experts in the humanities to build a sui generis philosophy of medicine. PMID:25040366

  15. Temperature dependent embryonic development of Trichuris suis eggs in a medicinal raw material.

    PubMed

    Vejzagić, Nermina; Kringel, Helene; Bruun, Johan Musaeus; Roepstorff, Allan; Thamsborg, Stig Milan; Grossi, Anette Blak; Kapel, Christian M O

    2016-01-15

    The therapeutic potential of infective pig whipworm eggs, Trichuris suis ova (TSO), is currently tested in several clinical trials on immune-mediated diseases. This paper studied the embryonic development of TSO in a medicinal raw product, where the parasite eggs were suspended in sulphuric acid (pH1). Unembryonated T. suis egg batches were stored at 5, 10, 15, 20, 25, 30, and 40°C (±1°C) and examined at 2, 4, 8, and 14 weeks. Subsequently, sub-batches from each temperature were allowed to embryonate for additional 14 weeks at 25°C, and selected samples were tested for infectivity in Göttingen minipigs. Both male and female pigs were used to evaluate eventual gender specific infectivity. Storage at 30°C up to 14 weeks and subsequent embryonation for 14 weeks at 25°C did not significantly reduce the overall larval establishment in minipigs, as compared to storage at 5°C and subsequent embryonation at 25°C. As marked impairment of egg development was observed during storage at 40°C, a second set of unembryonated egg batches were incubated at 30, 32, 34, 36, 38, and 40°C (±1°C) for 1-8 weeks. The development of the eggs was repeatedly examined by manual light microscopy, multispectral analysis (OvaSpec), and an egg hatching assay prior to the final testing in minipigs (Trial 1). These methods showed that the development started earlier at higher temperatures, but the long-term storage at higher temperature affected the egg development. The present study further documents tolerance of the TSO to storage at temperature 5-15°C, at which temperature development of larvae is not initiated. PMID:26790737

  16. Role of Pathogens in Multiple Sclerosis

    PubMed Central

    Libbey, Jane E.; Cusick, Matthew F.; Fujinami, Robert S.

    2015-01-01

    Multiple sclerosis (MS) is an inflammatory demyelinating autoimmune disease of the central nervous system (CNS). Although the etiology of MS is unknown, genetic and environmental factors play a role. Infectious pathogens are the likely environmental factors involved in the development of MS. Pathogens associated with the development or exacerbation of MS include bacteria, such as Mycoplasma pneumoniae and Chlamydia pneumoniae, the Staphylococcus aureus-produced enterotoxins that function as superantigens, viruses of the herpes virus (Epstein-Barr virus and human herpesvirus 6) and human endogenous retrovirus (HERV) families and the protozoa Acanthamoeba castellanii. Evidence, from studies with humans and animal models, supporting the association of these various pathogens with the development and/or exacerbation of MS will be discussed along with the potential mechanisms including molecular mimicry, epitope spreading and bystander activation. In contrast, infection with certain parasites such as helminthes (Schistosoma mansoni, Fasciola hepatica, Hymenolepis nana, Trichuris trichiura, Ascaris lumbricoides, Strongyloides stercolaris, Enterobius vermicularis) appears to protect against the development or exacerbation of MS. Evidence supporting the ability of parasitic infections to protect against disease will be discussed along with a brief summary of a recent Phase I clinical trial testing the ability of Trichuris suis ova treatment to improve the clinical course of MS. A complex interaction between the CNS (including the blood-brain barrier), multiple infections with various infectious agents (occurring in the periphery or within the CNS), and the immune response to those various infections may have to be deciphered before the etiology of MS can be fully understood. PMID:24266364

  17. Role of pathogens in multiple sclerosis.

    PubMed

    Libbey, Jane E; Cusick, Matthew F; Fujinami, Robert S

    2014-01-01

    Multiple sclerosis (MS) is an inflammatory demyelinating autoimmune disease of the central nervous system (CNS). Although the etiology of MS is unknown, genetic and environmental factors play a role. Infectious pathogens are the likely environmental factors involved in the development of MS. Pathogens associated with the development or exacerbation of MS include bacteria, such as Mycoplasma pneumoniae and Chlamydia pneumoniae, the Staphylococcus aureus-produced enterotoxins that function as superantigens, viruses of the herpes virus (Epstein-Barr virus and human herpesvirus 6) and human endogenous retrovirus (HERV) families and the protozoa Acanthamoeba castellanii. Evidence, from studies with humans and animal models, supporting the association of these various pathogens with the development and/or exacerbation of MS will be discussed along with the potential mechanisms including molecular mimicry, epitope spreading and bystander activation. In contrast, infection with certain parasites such as helminthes (Schistosoma mansoni, Fasciola hepatica, Hymenolepis nana, Trichuris trichiura, Ascaris lumbricoides, Strongyloides stercolaris, Enterobius vermicularis) appears to protect against the development or exacerbation of MS. Evidence supporting the ability of parasitic infections to protect against disease will be discussed along with a brief summary of a recent Phase I clinical trial testing the ability of Trichuris suis ova treatment to improve the clinical course of MS. A complex interaction between the CNS (including the blood-brain barrier), multiple infections with various infectious agents (occurring in the periphery or within the CNS), and the immune response to those various infections may have to be deciphered before the etiology of MS can be fully understood. PMID:24266364

  18. Virulence Gene Pool Detected in Bovine Group C Streptococcus dysgalactiae subsp. dysgalactiae Isolates by Use of a Group A S. pyogenes Virulence Microarray ▿

    PubMed Central

    Rato, Márcia G.; Nerlich, Andreas; Bergmann, René; Bexiga, Ricardo; Nunes, Sandro F.; Vilela, Cristina L.; Santos-Sanches, Ilda; Chhatwal, Gursharan S.

    2011-01-01

    A custom-designed microarray containing 220 virulence genes of Streptococcus pyogenes (group A Streptococcus [GAS]) was used to test group C Streptococcus dysgalactiae subsp. dysgalactiae (GCS) field strains causing bovine mastitis and group C or group G Streptococcus dysgalactiae subsp. equisimilis (GCS/GGS) isolates from human infections, with the latter being used for comparative purposes, for the presence of virulence genes. All bovine and all human isolates carried a fraction of the 220 genes (23% and 39%, respectively). The virulence genes encoding streptolysin S, glyceraldehyde-3-phosphate dehydrogenase, the plasminogen-binding M-like protein PAM, and the collagen-like protein SclB were detected in the majority of both bovine and human isolates (94 to 100%). Virulence factors, usually carried by human beta-hemolytic streptococcal pathogens, such as streptokinase, laminin-binding protein, and the C5a peptidase precursor, were detected in all human isolates but not in bovine isolates. Additionally, GAS bacteriophage-associated virulence genes encoding superantigens, DNase, and/or streptodornase were detected in bovine isolates (72%) but not in the human isolates. Determinants located in non-bacteriophage-related mobile elements, such as the gene encoding R28, were detected in all bovine and human isolates. Several virulence genes, including genes of bacteriophage origin, were shown to be expressed by reverse transcriptase PCR (RT-PCR). Phylogenetic analysis of superantigen gene sequences revealed a high level (>98%) of identity among genes of bovine GCS, of the horse pathogen Streptococcus equi subsp. equi, and of the human pathogen GAS. Our findings indicate that alpha-hemolytic bovine GCS, an important mastitis pathogen and considered to be a nonhuman pathogen, carries important virulence factors responsible for virulence and pathogenesis in humans. PMID:21525223

  19. Pathogen profile of clinical mastitis in Irish milk-recording herds reveals a complex aetiology.

    PubMed

    Keane, O M; Budd, K E; Flynn, J; McCoy, F

    2013-07-01

    Effective mastitis control requires knowledge of the predominant pathogen challenges on the farm. In order to quantify this challenge, the aetiological agents associated with clinical mastitis in 30 milk-recording dairy herds in Ireland over a complete lactation were investigated. Standard bacteriology was performed on 630 pretreatment quarter milk samples, of which 56 per cent were culture-positive, 42 per cent culture-negative and 2 per cent contaminated. Two micro-organisms were isolated from almost 5 per cent of the culture-positive samples. The bacteria isolated were Staphylococcus aureus (23 per cent), Streptococcus uberis (17 per cent), Escherichia coli (9 per cent), Streptococcus species (6 per cent), coagulase-negative Staphylococci (4 per cent) and other species (1 per cent). A wide variety of bacterial species were associated with clinical mastitis, with S aureus the most prevalent pathogen overall, followed by S uberis. However, the bacterial challenges varied widely from farm to farm. In comparison with previous reports, in the present study, the contagious pathogens S aureus and Streptococcus agalactiae were less commonly associated with clinical mastitis, whereas, the environmental pathogens S uberis and E coli were found more commonly associated with clinical mastitis. While S aureus remains the pathogen most commonly associated with intramammary infection in these herds, environmental pathogens, such as S uberis and E coli also present a considerable challenge. PMID:23694921

  20. Kinetics of Coinfection with Influenza A Virus and Streptococcus pneumoniae

    SciTech Connect

    Smith, Amber M.; Adler, Frederick R.; Ribeiro, Ruy M.; Gutenkunst, Ryan N.; McAuley, Julie L.; McCullers, Jonathan A.; Perelson, Alan S.

    2013-03-21

    Secondary bacterial infections are a leading cause of illness and death during epidemic and pandemic influenza. Experimental studies suggest a lethal synergism between influenza and certain bacteria, particularly Streptococcus pneumoniae, but the precise processes involved are unclear. In this paper, to address the mechanisms and determine the influences of pathogen dose and strain on disease, we infected groups of mice with either the H1N1 subtype influenza A virus A/Puerto Rico/8/34 (PR8) or a version expressing the 1918 PB1-F2 protein (PR8-PB1-F2(1918)), followed seven days later with one of two S. pneumoniae strains, type 2 D39 or type 3 A66.1. We determined that, following bacterial infection, viral titers initially rebound and then decline slowly. Bacterial titers rapidly rise to high levels and remain elevated. We used a kinetic model to explore the coupled interactions and study the dominant controlling mechanisms. We hypothesize that viral titers rebound in the presence of bacteria due to enhanced viral release from infected cells, and that bacterial titers increase due to alveolar macrophage impairment. Dynamics are affected by initial bacterial dose but not by the expression of the influenza 1918 PB1-F2 protein. Finally, our model provides a framework to investigate pathogen interaction during coinfections and to uncover dynamical differences based on inoculum size and strain.

  1. Streptococcus pyogenes biofilms—formation, biology, and clinical relevance

    PubMed Central

    Fiedler, Tomas; Köller, Thomas; Kreikemeyer, Bernd

    2015-01-01

    Streptococcus pyogenes (group A streptococci, GAS) is an exclusive human bacterial pathogen. The virulence potential of this species is tremendous. Interactions with humans range from asymptomatic carriage over mild and superficial infections of skin and mucosal membranes up to systemic purulent toxic-invasive disease manifestations. Particularly the latter are a severe threat for predisposed patients and lead to significant death tolls worldwide. This places GAS among the most important Gram-positive bacterial pathogens. Many recent reviews have highlighted the GAS repertoire of virulence factors, regulators and regulatory circuits/networks that enable GAS to colonize the host and to deal with all levels of the host immune defense. This covers in vitro and in vivo studies, including animal infection studies based on mice and more relevant, macaque monkeys. It is now appreciated that GAS, like many other bacterial species, do not necessarily exclusively live in a planktonic lifestyle. GAS is capable of microcolony and biofilm formation on host cells and tissues. We are now beginning to understand that this feature significantly contributes to GAS pathogenesis. In this review we will discuss the current knowledge on GAS biofilm formation, the biofilm-phenotype associated virulence factors, regulatory aspects of biofilm formation, the clinical relevance, and finally contemporary treatment regimens and future treatment options. PMID:25717441

  2. Interactions of Streptococcus iniae with phagocytic cell line.

    PubMed

    El Aamri, Fatima; Remuzgo-Martínez, S; Acosta, Félix; Real, Fernando; Ramos-Vivas, José; Icardo, José M; Padilla, Daniel

    2015-04-01

    Streptococcus iniae has become one of the most serious aquatic pathogens in the last decade, causing large losses in wild and farmed fish worldwide. There is clear evidence that this pathogen is capable not only of causing serious disease in fish but also of being transferred to and infecting humans. In this study, we investigate the interaction of S. iniae with two murine macrophage cell lines, J774-A1 and RAW 264.7. Cytotoxicity assay demonstrated significant differences between live and UV-light killed IUSA-1 strains. The burst respiratory activity decreased to baseline after 1 and 4 h of exposure for J774-A1 and RAW 264.7, respectively. Immunofluorescent and ultrastructural study of infected cells confirmed the intracellular localization of bacteria at 1 h and 24 h post-infection. Using qRT-PCR arrays, we investigated the changes in the gene expression of immune relevant genes associated with macrophage activation. In this screening, we identified 11 of 84 genes up-regulated, we observed over-expression of pro-inflammatory response as IL-1α, IL-1β, and TNF-α, without a good anti-inflammatory response. Present findings suggest a capacity of S. iniae to modulate a mammalian macrophages cell lines to their survival and replication intracellular, which makes this cell type as a reservoir for continued infection. PMID:24956597

  3. Nonencapsulated Streptococcus pneumoniae as a cause of chronic adenoiditis

    PubMed Central

    Dixit, Cheshil; Keller, Lance E.; Bradshaw, Jessica L.; Robinson, D. Ashley; Swiatlo, Edwin; McDaniel, Larry S.

    2016-01-01

    Streptococcus pneumoniae is an important human pathogen. To cause disease, it must first colonize the nasopharynx. The widespread use of pneumococcal-conjugate vaccines which target the capsular polysaccharide has led to decreased nasopharyngeal carriage of vaccine serotypes, but a concomitant increase in carriage of non-vaccine serotypes and nonencapsulated S. pneumoniae (NESp). Some NESp express pneumococcal surface protein K (PspK), a virulence factor shown to contribute to nasopharyngeal colonization. We present the case of a child with chronic adenoiditis caused by a PspK+ NESp. We tested the pneumococcal isolate, designated C144.66, for antimicrobial resistance, the presence of the pspK gene and the expression of PspK. Sequence typing and genome sequencing were performed. C144.66 was found to be resistant to erythromycin and displayed intermediate resistance to penicillin and trimethoprim/sulfamethoxazole. C144.66 has the pspK gene in place of the capsule locus. Additionally, PspK expression was confirmed by flow cytometry. NESp are a growing concern as an emerging human pathogen, as current pneumococcal vaccines do not confer immunity against them. An inability to vaccinate against NESp may result in increased carriage and associated pathology. PMID:27144125

  4. Streptococcus pneumoniae: elusive mechanisms of the body's defense systems.

    PubMed

    Bondi, T; Canessa, C; Lippi, F; Iacopelli, J; Nieddu, F; Azzari, C

    2012-06-01

    Streptococcus pneumoniae is one of the most important human pathogens. It represents the most frequent cause of pneumonia, meningitis, sinusitis and otitis. After the PCV7 vaccine introduction, a serotypic switch was noticed. This phenomenon led to the replacement of the seven serotypes contained in the vaccine with other less common ones, some of which are invasive or characterised by antibiotic-resistance. This replacement is only partially due to the vaccination. Many causes have been suggested to explain this effect: apearance of new serotypes, diffusion of minority serotypes and replacement of common serotypes due to natural secular trend. Pneumococcus has a promiscuous "sex life", characterized by homologous recombinations within the same species and also between different species. This fact can unlock the secret of how these pathogens can develop antibiotic or vaccine-resistance. The serotypic switch involves big loci that are responsible for capsular polysaccharide synthesis. The most important region of the genome involved in this process is near the gene tetM. The same mechanisms are also responsible for antibiotic resistance. In recent years the growth of penicillin, ma